Dissertations / Theses on the topic 'Inhibitory effects'
To see the other types of publications on this topic, follow the link: Inhibitory effects.
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Inhibitory effects.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Rasanayagam, Maretta Sharima. "Inhibitory effects of ectomycorrhizal fungi on other soil fungi." Thesis, University of Kent, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.332661.
Full text
2
Mortensen, Bennett Alan. "Effects of Whole Body Vibration on Inhibitory Control Processes." BYU ScholarsArchive, 2021. https://scholarsarchive.byu.edu/etd/9198.
Full textAbstract:
Vibrations are often experienced in the workplace and may influence performance and executive function. Research has shown that vibrations may have an affect effect on drowsiness and tests related to inhibitory control. Previous work investigating whole body vibrations (WBV) and their effect was evaluated to inform the decisions for this study. WBV effects on cognitive abilities were examined and the different tests used in these studies were identified and compared. Electroencephalogram (EEG) and event related potentials (ERP) were selected to be used to measure inhibitory and cognitive processes. The N2 ERP, which reflects inhibitory control processes, was examined as well as the dominant frequency of the Fourier fast transform (FFT). A total of 94 participants between the ages of 18-55 (Mage = 20.49 SDage = 1.68) completed this study (51 female, 38 male and 5 with no gender listed). A go/no-go task was used to elicit the N2 ERP after WBV and a simultaneous EEG recording while the participants experienced WBV was used to gather the needed data. Stimulus frequencies used for the N2 ERP included 15 Hz, 20 Hz, and 40 Hz. During the simultaneous recording stimulus frequency varied every 30 seconds by 10 Hz from 20 Hz to 110 Hz. Data were analyzed using both a linear mixed effects model for normally distributed data and a generalized linear mixed effects model for data taken as percentages. It was hypothesized that there would be an effect on performance as measured in the raw go/no-go results, that this change in performance showing improved accuracy would be linked to inhibitory control, and be seen as a decrease in the magnitude of the N2 ERP. It was also hypothesized that the exploratory FFT portion of the study would produce a shift from a higher to a lower frequency in the dominant waveform . The results show that there were no main effects in either the behavioral performance or in the N2 ERP of the participants but that there was a significant interaction at 40 Hz with improved simple go trial activity and decreased no-go inhibition. The results also show that there was a statistically significant shift in neural oscillation activity but that this shift was not real-world relevant within the context of this study.
3
Kramer, Rossana. "Effects of bilingualism on inhibitory control and working memory." reponame:Repositório Institucional da UFSC, 2012. http://repositorio.ufsc.br/xmlui/handle/123456789/96068.
Full textAbstract:
Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Comunicação e Expressão, Programa de Pós-Graduação em Letras/Inglês e Literatura Correspondente, Florianópolis, 2011Made available in DSpace on 2012-10-26T08:30:14Z (GMT). No. of bitstreams: 1 299504.pdf: 2117531 bytes, checksum: 08fecd70603a71919e015d3c0d703c86 (MD5)
O estudo da relação entre o bilinguismo e envelhecimento é uma área de pesquisa relativamente recente. O processo de envelhecimento produz alterações cognitivas em uma série de funções. A memória, atenção, raciocínio e resolução de problemas são algumas das funções que sofrem declínios relacionados ao envelhecimento (cf. Park e Schwarz, 2000). Pesquisas recentes conduzidas por Bialystok, Craik, Klein e Viswanathan (2004) forneceram evidências de que o bilinguismo poderia atenuar alguns efeitos negativos do envelhecimento e atuar como uma proteção às funções cognitivas ao longo da vida. O presente estudo se propôs a investigar (1) o desempenho de bilíngues de infância ou precoces (bilíngues que aprenderam as duas línguas quando crianças) e bilíngues tardios (indivíduos que aprenderam a segunda língua após os 12 anos de idade em contexto de sala de aula) em tarefas de controle inibitório e de memória de trabalho; (2) o desempenho de homens e mulheres em tarefas de controle inibitório e memória de trabalho e (3) o desempenho dos participantes em duas versões da tarefa Simon (quadrados e flechas) para tratar de questões relacionadas à metodologia de mensuração de funções cognitivas. Para alcançar os objetivos propostos, 104 participantes entre 18 e 84 anos divididos em 4 grupos de monolíngues, falantes de português brasileiro (PB) e 4 grupos de bilíngues # 3 grupos de bilíngues precoces (Hunsrückisch/PB) de Iporã do Oeste e Mondaí em Santa Catarina e 1 grupo de bilíngues tardios (PB/Inglês) selecionados na Universidade Federal de Santa Catarina # realizaram tarefas de controle executivo (Tarefa Simon) e de memória de trabalho (Tarefa Alpha Span). Além das tarefas, questionários sobre experiência linguística e informações gerais, o Mini Exame do Estado Mental (MEEM) e o inventário Beck de depressão foram aplicados aos participantes. Os bilíngues tardios, além de responderem aos questionários e testes, foram submetidos a um teste de proficiência em língua inglesa. As análises estatísticas demonstraram perdas cognitivas significativas relacionadas à idade, uma vez que adultos jovens foram melhores que os idosos nas tarefas de controle inibitório e memória de trabalho. Apesar de não ter sido verificada uma diferença estatisticamente significativa entre monolíngues e bilíngues precoces nas mesmas faixas de idade, bilíngues precoces apresentaram maior eficiência nos processos inibitórios e pontuaram mais que os monolíngues na tarefa de memória de trabalho. Os resultados confirmaram que bilíngues tardios foram significativamente melhores que os monolíngues em controle inibitório. As análises estatísticas não confirmaram diferenças com relação ao desempenho de homens e mulheres nas tarefas. No entanto, a versão Simon de quadrados tende a favorecer as mulheres. Os resultados são discutidos à luz de estudos teóricos e empíricos sobre bilinguismo, envelhecimento e perdas cognitivas.
The study of the relationship between bilingualism and aging is a relatively recent area of research. The aging process brings with it cognitive declines in a number of functions, including attention, memory, reasoning, and problem-solving (Park and Schwarz, 2000). Recently, however, Bialystok, Craik, Klein & Viswanathan (2004) have provided evidence that bilingualism aids in offsetting age-related losses in executive function. The present study aims at: 1) investigating the performance of early bilinguals, i.e., those who have used two languages on a daily basis across the lifespan, and late bilinguals, i.e., those who have learned a second language through instruction in the classroom, on inhibitory control and working memory tasks; 2) investigating sex differences in the performance of these two types of bilinguals on inhibitory control and working memory tasks, and 3) investigating a methodological issue related to the assessment of inhibitory control by comparing the performance of participants on two different versions of the Simon task (the Simon task 2 Colors and the Simon Arrow task). One hundred and four participants, with ages ranging from 18 to 84 years, took part in the study. These participants were divided into 4 control groups of Brazilian Portuguese monolingual speakers and 4 experimental groups consisting of 3 groups of Brazilian Portuguese/ Hunsrückisch speakers and 1 group of Brazilian Portuguese/English speakers. Before performing the inhibitory control and working memory tasks, each participant answered a language background questionnaire and a general questionnaire and was given the Mini-Mental State Exam and the Beck Depression Inventory. Late bilinguals were also submitted to a proficiency test. Results of statistical analyses showed significant age-related losses in executive functions: younger adults outperformed older adults in the tasks. Although there was not a statistically significant difference between language groups across the lifespan, early bilinguals presented more efficient inhibitory processes and higher working memory span than conolinguals. As regards late bilingualism, late bilinguals. performance was significantly faster than monolinguals on inhibitory control tasks. Moreover, the statistical analysis did not show any statistically significant differences between males and females concerning inhibitory control and working memory, but the 2 Color version of the Simon task tends to favor women. The results are discussed in light of the theoretical and empirical literature on bilingualism, aging, and cognitive decline
4
Buonomano, Lisa Cristine. "Stimulus Matters: Effects of Familiarity versus Novelty." Thesis, Virginia Tech, 2008. http://hdl.handle.net/10919/31625.
Full textAbstract:
The ability to suppress a prepotent response is a crucial component of cognition that begins to develop during infancy and peeks during preschool. As part of understanding how one develops inhibitory control, learning about what conditions may help or hurt task performance is of great interest. The purpose of this project was to study the effects of familiarity and novelty on inhibitory control. Thirty-five preschoolers between two and five years of age were tested in four different versions of the Dimensional Change Card Sort (DCCS). Performance was no different among standard, 2D-familiar, and 3D-familiar conditions. When comparing novel with the standard condition, children performed worse (37% and 68% respectively). Findings support the attentional inertia hypothesis. An exploratory analysis on temperament was also investigated. Children who scored higher in effortful control performed better in the 2D-familiar condition.Master of Science
5
Barker, Ellen. "Investigating the effects of Zeta Inhibitory Peptide on AMPAR trafficking." Thesis, University of Bristol, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.628992.
Full textAbstract:
In recent years, several studies have suggested a role for PKMs, an atypical isoform of PKC, in memory consolidation and long-term potentiation (LTP). Some evidence in support of this theory has come to light, in the form of electrophysiological and behavioural studies, using inhibition, knockdown, perfusion of the molecule itself and overexpression. Exogenously applying the PKM~ to systems leads to potentiation. Conversely, application of Zeta Inhibitory Peptide (ZIP), a peptide sequence purported to inhibit PKMs, consistently reverses LTP and in most cases, erases memories. To date, however, studies on PKMs have focused on functional aspects of PKMs activity (i.e. behaviour and synaptic function) while the molecular events underlying these processes are poorly understood and there are currently few published studies closely examining such details. The experiments performed for this thesis attempt to better understand the molecular effects of ZIP in AMPAR trafficking, and result in some novel findings on the subunitspecific effects, the mechanisms involved, as well as some data showing effects of different concentration of inhibitor. Experiments performed for this project showed that ZIP causes an increase in internalisation of GluAl and GluA2 subunits, and a decrease in surface GluA2, but not GluAl. Previously it had been reported that ZIP leads to a decrease in synaptic function and loss of memory, and this effect can be blocked by preventing GluA2 internalisation. These data are therefore consistent with published studies and also show a new effect regarding the trafficking of the GluAl subunit. It was also shown that PICKl interaction with GluA2, as well as actin depolymerisation are required for the increase in internalization (Rocca et al., 2008) and that PICKl interaction with GluA2 may be increased in the presence of ZIP. These new data support the theory NSF and PICKl are involved in the trafficking activity of PKMs on GluA2 (Yao et al., 2008), and that the loss of synaptic function observed in the presence of ZIP requires PICKl (Yao et al., 2008).
6
Casiro, Jessica Ananda. "Onset density and inhibitory effects on lexical access in speech production." Thesis, University of British Columbia, 2008. http://hdl.handle.net/2429/5583.
Full textAbstract:
Lexical access in speech production involves multiple processing stages, beginning with the
mental generation of a target concept and ending with a speaker's articulation of the target word. The
current study aimed to explore the influence of competition and inhibition on the process of lexical
access. In particular, the position of phonological overlap between a target word (e.g., lip) and its
neighbors (e.g., lid vs. sip) was investigated for its influence on picture naming. It was hypothesized
that greater inhibitory effects and slower response times in participants' naming would be observed for
target words that have a predominance of neighbors which are onset related compared to those which
are rhyme related. In addition, it was predicted that there would be a strong relationship between
performance on the naming task and several inhibition tasks due to the common role of inhibition
across tasks. Twenty-five native English participants completed a picture naming task, two language
based inhibition tasks, and two non-language inhibition tasks. Participants' response times were
recorded for incongruent/dense and congruent/sparse trials, and mean difference scores were examined
to determine the inhibition effect sizes.
The results showed that response times for dense onset trials were significantly slower than
sparse onset trials, thereby supporting the first hypothesis. Inter-task correlation results, however, did
not provide support for the second hypothesis that inhibition capacity would be common to different
tasks. Factors such as varying task characteristics, modality of stimulus presentation, length of testing
session, task counterbalancing, perceived task difficulty, and allocation of cognitive effort are
discussed as having contributed to the lack of significant correlations.
7
Trinkle, Mara. "The Inhibitory Effects of an Antimicrobial Gel on the Staphylococcus Species." Digital Commons @ East Tennessee State University, 2020. https://dc.etsu.edu/honors/540.
Full textAbstract:
The prevalence of antibiotic resistant bacteria has made the choices for topical treatments for patients who experience burns wounds extremely limited. The Staphylococcus genus is naturally occurring in and on the human body but can become harmful once it enters the bloodstream. A novel antimicrobial gel has been shown by our laboratory to inhibit both the planktonic growth and biofilm formation of Staphylococcus aureus in previous studies. The antimicrobial gel is made of seven natural compounds including antioxidants (vitamin C and E). We wanted to examine the effects of the antimicrobial gel on numerous other Staphylococcal species because it is prevalent on the body and becomes harmful when the immune system is compromised. The species tested were Staphylococcus capitis, Staphylococcus epidermidis, and Staphylococcus saprophyticus. A planktonic broth challenge test, biofilm attachment test, and biofilm maturation test were all performed in order to test this hypothesis. These tests showed a significant inhibition of the Staphylococcus species as a result of the effects of the antimicrobial gel. The antimicrobial gel inhibited the attachment, maturation, and growth of Staphylococcus colonies in a 10% antimicrobial gel solution. The antimicrobial gel shows promise as an option in treating burn patients and should be considered in further testing for its uses in other areas of medicine.
8
Vance, Lindsey. "The Inhibitory Effects of a Novel Gel on Staphylococcus aureus Biofilms." Digital Commons @ East Tennessee State University, 2018. https://dc.etsu.edu/honors/435.
Full textAbstract:
Antibiotic resistance is an ever-growing topic of concern within the medical field causing researchers to examine the mechanisms of resistance to develop new antimicrobials. Bacteria’s ability to form biofilms is one mechanism which aids in antimicrobial resistance. Staphylococcus aureus is of special interest as it is one of the most frequent biofilm-forming bacteria found on medical devices causing infections and posing dangerous threats in a clinical setting. A recently developed antimicrobial gel has been shown to have profound effects on treating bacterial infections and wound healing. This research is centered upon examining the antimicrobial effects of this gel on the three different stages of biofilm formation in clinical and laboratory strains of S. aureus. Through a series of experiments examining the effects this gel has on S. aureus at the stages of biofilm attachment, maturation, and dispersion, the gel has shown significant levels of inhibition. These findings indicate that the novel gel disrupts biofilm forming processes of S. aureus, which provides useful information for fighting infections in the medical field. Further research on the uses and effects of this new gel could lead possibility using the antimicrobial compound for a variety of clinical purposes.
9
De, Sousa Sara Luisa Mellor. "Effects of the general anaesthetics isoflurane and xenon on synaptic transmission in isolated hippocampal neurones." Thesis, Imperial College London, 1999. http://hdl.handle.net/10044/1/8593.
Full text
10
Williams, Tyson. "The rapid analysis of fungal growth in the presence of inhibitory effects." Thesis, Cranfield University, 2011. http://dspace.lib.cranfield.ac.uk/handle/1826/7183.
Full textAbstract:
For fungal contamination of foodstuffs, there are no fast, reliable, automated techniques to examine growth, nor have any predictive models been developed to describe the growth in the same way as for bacteria. Traditional plating methods can take 3 to 7 days to get adequate results depending on the fungal species utilised and well over a month for challenge testing, an unacceptable delay especially for the food industry. In this study two rapid analysis techniques were investigated, conductimetry (direct and indirect) and turbidimetry (Bioscreen), with the sole objective being to analyse their capability to detect fungal growth in optimum conditions and in the presence of inhibitory agents, in this case sorbic acid and vanillin. Three fungal (Aspergillus niger, Fusarium oxysporum and Pencillium verrucosum) and one yeast species (Saccharomyces cerevisiae) were used, though only A. niger growth was analysed using both of the rapid analysis techniques. Two bacterial species (Escherichia coli and Salmonella enterica serovar typhimurium) were also tested using the conductimetry technique for comparison. It was found that both the impedance and turbidimetry methods provided a sensitive and rapid means of detecting, and, under standardised conditions, measuring the activity of micro-organisms. The rate of response showed close correlation with the concentration of both bacteria and spores in the initial inoculum for each strain tested so correlation curves could be constructed to estimate the number of viable cells and spores in a suspension. Moreover, both methods can be used for the accurate screening of potential antimicrobial substances. In comparison with the turbidimetry method though, the impedance method did show a greater deal of variability and there is the possibility it is unsuitable for the analysis of certain fungal species. In addition the direct impedance technique was found to be completely unusable for the analysis of fungal growth. Despite these disadvantages both are promising rapid alternatives to the standard plating technique.
11
Miller, Melissa A. "Examining the Vulnerability of Inhibitory Control to the Impairing Effects of Alcohol." UKnowledge, 2014. http://uknowledge.uky.edu/psychology_etds/46.
Full textAbstract:
There is growing evidence that acute changes in fundamental mechanisms of impulse control contribute to the transition from social drinking to abusive drinking. One component of impulsivity concerns the ability to inhibit maladaptive behaviors (i.e., inhibitory control). Inhibitory mechanisms are reliably shown to be sensitive to the impairing effects of alcohol, and studies have begun to show that this impairment fails to recover at the same speed as other aspects of behavior. However, the degree to which inhibitory control develops tolerance to alcohol has only been examined under limited conditions. This dissertation consists of three studies examining contexts in which tolerance has been observed for a host of prototypic behaviors, and will compare the degree to which it fails to develop for inhibitory control. Study 1 examined the rate of recovery for inhibitory control compared with other behaviors as blood alcohol concentrations (BACs) declined to zero following a dose of alcohol in 24 social drinkers. Results revealed prolonged alcohol impairment of inhibitory control along the BAC curve, even as BACs approached zero. By contrast, behaviors including reaction time and motor coordination began to show recovery markedly faster, as BACs were still significantly elevated. Study 2 examined the degree to which recent drinking patterns predict acute alcohol impairment from alcohol in a group of 52 drinkers. Recent, heavy consumption predicted less impairment of motor coordination, but bore no relationship to the magnitude of impairment of inhibitory control. Study 3 examined whether increasing the stimulus strength of environmental cues signaling the need to inhibit behavior could reduce alcohol impairment of inhibitory control in 56 participants. Results showed that increasing stimuli strength reduced alcohol impairment of behavioral activation, but actually increased inhibitory failures. Taken together, the findings contribute to the growing body of evidence suggesting that inhibitory control is especially vulnerable to the impairing effects of alcohol compared with other behaviors. Indeed, these studies systematically assessed the pharmacokinetic and environmental factors that contribute to tolerance, indicating that inhibition is disrupted in circumstances under which response activation is unimpaired. The findings have important implications for understanding the behaviorally-disruptive effects of alcohol.
12
Blair, Tesha E. "The Apoptotic and Inhibitory Effects of Phylloquinone in the U937 Cell Line." Digital Commons @ East Tennessee State University, 2016. https://dc.etsu.edu/etd/3028.
Full textAbstract:
Phylloquinone is a natural analog of vitamin K that has been shown to both inhibit cancer cell growth and induce apoptosis in several cancer cell lines. This study examined these effects in a non-Hodgkin lymphoma cell line, known as U937. Cell growth inhibition and apoptosis were assessed through the quantification of cell density and area, following treatment with several concentrations of phylloquinone. In addition, apoptosis was detected and quantified using immunofluorescent markers of apoptosis (i.e. annexin V, APO-BrdU). Treatment with phylloquinone resulted in reduced overall cell density, increased overall cell area, and an increased frequency of apoptosis in U937 cells. Increasing both phylloquinone concentration and treatment time enhanced these effects. These results are significant because they document the anti-cancer effects of this analog of vitamin K, as well as provide insight into the morphological changes that occur during apoptosis in U937 cells.
13
Chandok, Ravi. "Inhibitory effects on human immunodeficiency virus type-1 by insulin-like growth factor-1." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape16/PQDD_0002/MQ37103.pdf.
Full text
14
Wang, Sheng. "Effects of nitric oxide on excitatory and inhibitory transmission in the nucleus tractus solitarius." Thesis, University of Bristol, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.422549.
Full text
15
Wood, Claire. "Understanding the inhibitory effects of plant-derived isothiocyanates and biofumigation on potato cyst nematodes." Thesis, University of Newcastle upon Tyne, 2018. http://hdl.handle.net/10443/4129.
Full textAbstract:
Management of potato cyst nematodes (PCN) has become more challenging due to nematicide restrictions. This has led to research into alternative control methods such as biofumigation. Biofumigation exploits the release of toxic isothiocyanates (ITCs) from glucosinolate (GSL) hydrolysis during the breakdown of Brassicaceae plant tissue. The type and concentration of ITCs released varies between plant species. Biofumigation and ITCs have been shown to control soil-borne pathogens however no single ITC achieves broad-range control. The main aim of this study was to determine if biofumigation can be used to control PCN, namely Globodera pallida. In vitro and glasshouse studies identified a key ITC which inhibited G. pallida, with ITC effectiveness depending upon ITC type, concentration and exposure period. The GSL profiles of different Brassicaceae spp. were analysed and results indicated that GSL content varies between species and throughout plant development. The biofumigation process was investigated in glasshouse and field trials and analysis of GSL profiles allowed a comparison of cultivars with respect to potential ITC release. Cultivars which released the identified key ITC were able to suppress encysted G. pallida under controlled conditions. External factors impacted on the effectiveness of biofumigation in field trials. In order to determine if biofumigation adversely affects soil microorganisms, shifts in soil microbial communities were investigated. ITC application under controlled conditions and biofumigation under field conditions had little effect on soil microorganisms. Transient shifts in communities occurred in response to biofumigation under controlled conditions. The greatest response of soil communities was to factors independent of biofumigation. Results from this study will feed back into the development of integrated PCN management strategies involving biofumigation as well as into biofumigant breeding programmes.
16
Lin, Yin-Chieh, and 林頴婕. "The inhibitory effects of sirtinol, a sirtuin inhibitor, on invasiveness of lung cancer cells." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/84457496731343543805.
Full textAbstract:
碩士高雄醫學大學
生物科技學系碩士班
100
Sirtuin (SIRT) family is a class III histone deacetylase (HDAC). In mammalian cells, SIRTs were reported to exert the activities of NAD+-dependent deacetylase, which target histones and a variety of non-histone proteins in different subcellular compartments. Among SIRT proteins, SIRT1 involves in a variety of cellular processes that determines longevity, such as anti-apoptosis, cellular senescence, ageing, and certain metabolism pathways. Previous studies showed the physiological role of mammalian SIRT1 in tumorigenesis and cellular longevity. However, the precise effect of SIRT1 is highly dependent on the genetics of the cell and the presence or absence of p53. Our preliminary results showed the overexpression of SIRT1 in non-small-cell lung cancer cells (NSCLC), especially the two most invasive NSCLC H1299 and CL-1 cells. Accordingly, we proposed the high correlation of metastasis and SIRT1 overexpression and the critical role of SIRT1 in promoting tumorigenesis of NSCLC. To test the hypothesis, the specific inhibitor of sirtuin, sirtinol was used in our study. Proliferation assay and annexin-V staining showed the low cytotoxicity of sirtinol towards NSCLC H1299 cells. On the contrary, the hallmarks of metastasis, the ability of cellular migration, invasion and anchorage-independent growth were effectively attenuated by sirtinol. Furthermore, the Western blot result showed that sirtinol inhibited the phosphorylation of Src, an important tyrosine kinase associated with cellular metastasis. The result suggests that sirtinol may inhibit migration or anchorage independent growth through Src signaling pathway. Our study indicates the correlation of SIRT1 and Src signaling in modulating the metastasis of NSCLC cells. The Western blot result also showed that the protein level of FOXO3a, RYK, Tyk2, FAK/Pyk2 were increased after sirtinol treatment, suggested that sirtinol may inhibit the cell invasiveness ability through these proteins up-regulation. According to gelatin zymography and Western blot results, we also found that sirtinol-induced inhibition of SIRT down-regulates the protein level of SP1 and MMP-9 activity. Overall, this study demonstrates that sirtinol-induced SIRT1 inhibition potently attenuates the metastasis ability of NSCLC cells, suggesting the promising therapy of lung cancer by targeting SIRT1 in the future.
17
Tsai, shing-jen, and 蔡幸真. "Inhibitory effects of phenolics on xanthine oxidase." Thesis, 1996. http://ndltd.ncl.edu.tw/handle/18039575583561048525.
Full textAbstract:
碩士國立臺灣大學
藥學研究所
84
partI: Thirty-eight phenolics have been tested for their inhibitory effects on xanthine oxidase,the results showed that the benzophenones,3,4,5,2',3',4'-hexahydroxybenzophenone, 2,2', 4,4'-tetrahydroxybenzophenone and 2,3',4,4'-tetrahydroxybenzo phenone showed potent inhibitory activities. The coumarin, 5,7- dihydroxy-4-methylcoumarin also displayed strong activity on xanthine oxidase inhibition. PartII:Xanthine-xanthine oxidase- cytochrome C system was used in the tests of superoxide radical scavenging effects, 3,4,5,2',3',4'-hexahydroxybenzophenone showed the strongest activity. PartIII:Phenolics have been tested the scavenging effects of the superoxide radical in whole blood of patients with ankylosing spondylitis, 3,4,5,2',3',4'- hexahydroxybenzophenone displayed the most potent activity.
18
Lee, Po-Xuan, and 李柏萱. "The inhibitory effects of andrographolide on malignant." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/92104572950940240795.
Full textAbstract:
碩士國立陽明大學
傳統醫藥研究所
102
Andrographolide is the main ingredient in the leaves of Andrographis paniculata. Currently, andrographolide is known to exhibit anti-cancer activity on various types of human cancers, including breast cancer and colon cancer. Breast cancer is most common type of cancer in women. Among different types of breast cancer, triple negative (ER-, HER2-, PR-) breast cancer is highly malignant and less responsive to conventional chemotherapy. Therefore, developing more effective treatment strategy is in great demand. On the other hand, Thoc1 is a component of the transcription/export complex (TREX), whose functions include assisting RNA pol II for transcription, RNA processing and nuclear export. The expression level of Thoc1 correlates with the proliferation and metastasis potential of human breast cancer cells, indicating that Thoc1 is a potential drug target. Currently, the effet of andrographolide on triple negative breast cancer cells and on Thoc1 expression level has never been explored. In this study, we investigate the cytotoxic effects of andrographolide and its derivatives on a triple negative breast cancer cell line MDA-MB-231 which has elevated Thoc1 expression. Furthermore, the molecular mechanisms underlying andrographolide-mediated cell death of MDA-MB-231 was also determined. The cytotoxicity of andrographolide on MDA-MB-231 was measured with MTT assays. We found that andrographolide effectively reduced the viability of MDA-MB-231 but had less toxic effect on human immortalized BJ-1 cells. In addition, andrographolide-mediated cell death occurred through both autophagy and apoptosis. Andrographolide promoted autophagy via increasing the formation of autophagosome marker, LC3-II. In addition, andrographolide also increased the activity of apoptotic enzyme Caspase-3. Suppression of andrographolide-induced autophagy in MDA-MB-231 cells with an autophagy inhibitor 3-MA attenuates the Caspase-3 activation. However, Treatment with an apoptosis inhibitor Z-VAD-FMK did not affect the andrographolide-induced LC3-II production. Notably, andrographolide could suppress Thoc1 expression in MDA-MB-231, and the expression level of Thoc1 reversely correlated with the production of autophagosome marker LC3-II. Moreover, compared with the control groups, both autophagic and apoptotic markers were affected in thoc1-knockdowned or thoc1-overexpressing cells. Nevertheless, the role of Thoc1 in andrographolide -induced apoptosis remains to be further evaluated. The cytotoxic activity of several andrographolide analogs on MDA-MB-231 was also evaluated. Among them, NCTU-322 and Andro-NBD could reduce Thoc1 expression, induce autophagy and promote cell death at lower concentrations than andrographolide. Notably, both compounds at the effective concentrations did not cause significant cell death of human immortalized BJ-1 cells. In conclusion, andrographolide could decrease the viability of MDA-MB-231 through induction of autophagy and apoptosis. Andrographolide also decreases the expression of Thoc1, a known tumor-promoting protein in breast cancer. Together, this study demonstrates that andrographolide is a potential compound for the treatment of triple-negative human breast cancer.
19
Chen, Ya-Yu, and 陳雅郁. "Inhibitory effects of rosmarinic acid on pterygium." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/b82hfg.
Full textAbstract:
博士中山醫學大學
醫學研究所
106
Pterygium is a common tumor-like ocular disease, which may be related to exposure of chronic ultraviolet (UV) radiation. Though the standard treatment for pterygium is surgical intervention, the recurrence of pterygium is high when no effective inhibitory drug is used after surgery. Rosmarinic acid (RA) is a polyphenol antioxidant, which has many biological activities including anti-UV and anti-tumor. This study was to examine the inhibiting effects of RA on pterygium epithelial cells (PECs). MTT assay was used for examining the cell cytotoxicity of PECs after RA treatment. Acridine orange (AO)/DAPI staining was stained with PECs for examing cell viability. A fluorescent probe, DCFH-DA (2’,7’-dichlorofluorescin diacetate), was stained with PECs for measuring intracellular ROS (reactive oxygen species) levels. Antioxidant activity assays were measured the levels of superoxide dismutase (SOD) and catalase (CAT) in PECs. Western blot analysis was used to determine the protein expression of Nrf2, HO-1, NQO1, apoptosis associated proteins and TGF-β/Smad signaling associated proteins. RA significantly reduced the cell viability of the PECs. Treatment with RA could remarkably increase the Nrf2 protein expression levels in nucleus, HO-1 and NQO1 protein expression levels, and activities of SOD and CAT. As a result, intracellular ROS levels in PECs were decreased. In addition, the induction of extrinsic apoptosis on PECs by RA was also associated with the increasing of Fas, FADD, TNF-α and caspase 8 protein expression levels. Moreover, the induction of PECs intrinsic apoptosis cell death was confirmed through up-regulation of cytochrome c, Bax, caspase 9 and caspase 3, down-regulation of Bcl-2 and pro-caspase 3. Our study demonstrated that RA could inhibit the viability of the PECs via regulation of extrinsic and intrinsic apoptosis pathway. Since fibrosis is an important mechanism beyond pterygium recurrence, our results showed that RA could down-regulating TGF-β/Smad signaling through decreasing TGF-β1, TGF-βRII, p-Smad1, p-Smad2, p-Smad3, Smad4, p-Smad5 and type I collagen protein expression levels. Therefore, RA may have potential for pterygium therapeutic medication.
20
Lin, Lu-Chun, and 林侶君. "The Inhibitory Effects of Mulberry Extracts on Melanogenesis." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/16645199440632138504.
Full textAbstract:
碩士嘉南藥理科技大學
生物科技系暨研究所
93
Abstract The objective of this research is to investigate the different parts of the mulberry which contains the best potential skin-whitening components and the best extractive conditions. It is also to investigate the inhibitory effects of mulberry extracts on melanogenesis and relative mechanism on cell biology. This research used mulberry''s leaves, branch powders, branch sections, young twigs and half ripe fruits as materials. Materials used microwaved with 95% alcohol ; 80% alcohol ; 50% alcohol ; 20% alcohol and water as solvents to extract. These extracts were evaluated based on inhibitory effects on melanogenesis. The evaluated items are : (1) The percentage inhibition of mushroom tyrosinase activity and IC50 , (2) The percentage inhibition of melanin in B-16 melanoma cell supernatant, (3) The percentage inhibition of melanin in B-16 melanoma cell lysate, (4) The cell lysate of enzyme activity (5)The extracts inhibitory effects on B-16 melanoma cells examined under electronic microscope. The results showed all of the various mulberry''s leaves‚ branch powders‚ branch sections‚ young twigs‚ half ripe fruits extracts could exert distinctive potency on inhibition of mushroom tyrosinase activity. Among these extracts, both mulberry''s branch powders extracts and branch sections extracts showed the best potent inhibition activity and a dose-dependent inhibitory effect on mushroom tyrosinase activity. We determined the effect of these extracts on mushroom tyrosinase inhibition by IC50 . The 80% alcohol extracts of the mulberry''s branch powders showed the best IC50 was 2.3μg∕mL. Both the 80% alcohol extracts of the mulberry''s branch powders and the 80% alcohol extracts of the mulberry''s branch sections showed the best potent inhibition activity and a dose-dependent inhibition percentage of melanin in B-16 melanoma cell supernatant, too. The synthesis of melanin in B-16 melanoma cells was also inhibited by the 80% alcohol extracts of the mulberry''s branch powders and the 80% alcohol extracts of the mulberry''s branch sections. The results showed the mulberry''s branch content has the best potential skin-whitening components. The mulberry''s branch to be treated with the dry and abrasive procedure. To immerse the mulberry''s branch powders in the 80% alcohol for one hour. After that use microwave to extract for 6 minutes to get the potent inhibitory effects activity of mulberry extracts on melanogenesis. The extracts showed no cytotoxicity when treated for B-16 melanoma cells . The mulberry is common and easy to plant in Asia and Taiwan and is inexpensive. The results are encouraging and deserve further advanced application to develop and discover the skin-whitening ingredients which have proven to be secure, effective, inexpensive with no contamination. Keywords：mulberry, melanogenesis, mushroom tyrosinase, B-16 melanoma cell
21
Zhang, Wen Xing, and 張文倖. "Inhibitory effects of phenolic compounds on xanthine oxidase." Thesis, 1994. http://ndltd.ncl.edu.tw/handle/87773642529509493342.
Full text
22
Huang, Hsin Ying, and 黃馨瑩. "Inhibitory Effects of Curcumin Emulsion on Acne Bacteria." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/64165991532712746349.
Full textAbstract:
碩士長庚大學
生化與生醫工程研究所
99
Curcumin has anti-bacterial, anti-inflammatory, and anti-oxidation effects. The aims of this study were to screen essential oil and free fatty acid for the inhibition of skin bacteria. Synergistic effects of curcumin and lauric/ myristic acid were found in the inhibition of Staphylococcus epidermidis and Propionibacterium acnes. Curcumin combined with the fatty acids was used to prepare microemulsions for topical delivery. The characteristics of developed microemulsions including viscosity, conductivity, and surface tension were analyzed. The transdermal delivery efficacy and skin retention of curcumin-containing microemulsion were evaluated using neonate pig skin mounted on a Franz diffusion cell. Significant effects on curcumin accumulated in skin were observed from microemlsions containing different surfactant/ water content. Histological examination and FTIR analysis of treated skin was performed to investigate the change of skin morphologies. In conclusion, microemulsion loaded with curcumin and fatty acids is a promising tool for the topical delivery of curcumin.
23
Chen, Yu-Wen. "Inhibitory Effects of Bowman-Birk Inhibitor on Proteasome Activity and Cell Proliferation in MCF7 Breast Cancer Cells;Inhibitory Effects of Black Theaflavins on Proteasome Activity and Cell Proliferation in Cancer Cell Lines." 2004. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0001-0607200415141200.
Full text
24
Chen, Yu-Wen, and 陳郁雯. "Inhibitory Effects of Bowman-Birk Inhibitor on Proteasome Activity and Cell Proliferation in MCF7 Breast Cancer Cells;Inhibitory Effects of Black Theaflavins on Proteasome Activity and Cell Proliferation in Cancer Cell Lines." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/19178450503899815188.
Full textAbstract:
碩士國立臺灣大學
生物化學暨分子生物學研究所
92
Abstract Protease inhibitors are a class of well-established cancer chemopreventing agents. Among several types of protease inhibitors, the Bowman-Birk inhibitor (BBI), a soybean-derived protein with the well-characterized ability to inhibit trypsin and chymotrypsin activities, has been shown to be an effective suppressor of carcinogenesis and treated in phaseⅡa clinical trial in human. However, the precise mechanisms by which BBI suppresses carcinogenesis are unknown. In this study, we demonstrated that BBI specifically and potently inhibits the proteasomal chymotrypsin-like activity in vitro and in vivo in MCF7 breast cancer cells. Inhibition of the proteasome by BBI is associated with accumulation of ubiquitinated proteins and the known proteasome substrates, p21Cip1/WAF1 and p27Kip1, accompanied with down-regulation of cyclin D1 and cyclin E which led to arrest cell cycle at G1/S phase. Furthermore, BBI suppressed MCF7 cell growth without showing cytotoxicity and had a novel effect on a loss of phoshporylated extracellular signal-related kinases (ERK1/2) when comparison with well-characterized chemopreventive agents. BBI was unable to inactivate ERK1/2 in the presence of a phosphatase inhibitor, sodium orthovanadate, or a transcriptional inhibitor, actinomycin D, suggesting the involvement of a specific phosphatase. We found an induction of dual specific MAP kinase phosphatase-1 (MKP-1) in dose- and time-dependent fashion which was correlated with dephosphorylation of ERK1/2 in BBI-treated MCF7 cells. In addition, BBI exhibited no inhibitory effects on EGF-induced activation of ERK1/2 and Akt. Taken together, we demonstrated that BBI indeed suppressed ERK1/2 activity via up-regulation of MKP-1 mediated by blockade of proteasome function. Our results supported the notion that the inhibition of proteasome activity by BBI is a novel mechanism that might contribute to cancer preventative effects of BBI. This study further provides the evidence that soybean products intake indeed have the potential to advance as chemopreventive agents. Inhibitors of proteasome are currently emerging as novel cancer preventing and therapeutic agents. To determine whether the tea polyphenols, including theaflavin, theaflavin-3-gallate, theaflavin-3’-gallate, theaflavin-3,3’-digallate (TF3), and (-)-epigallocatechin-3-gallate (EGCG) were potential proteasome inhibitors, we treated purified 20S or 26S proteasome and 26S proteasome in leukemia and cancer cell lines with these compounds. TF3 displayed a potent inhibitory effect on the growth of U937 cells with an estimated IC50 value of 6μM. Furthermore, TF3 had more efficient inhibition on the proteasomal chymotrypsin-like activity of purified proteasome derived from different sources and 26S proteasome in four kinds of cancer cell extracts as compared to those of EGCG. In addition, the theaflavins, especially TF3, inhibited the proteasomal chymotrypsin-like and peptidyl glutamyl peptide hydrolase (PGPH) activities of 26S proteasome in a concentration-dependent manner in human breast cancer MCF7 cells which have been described to be resistant to apoptosis induced by proteasome inhibitors. These results illustrated that proteasome inhibition by theaflavins lead to anti-proliferation of MCF7 cells. Furthermore, comparing well-characterized polyphenols on proteasome inhibition, the ester bond-bearing compounds, with some exceptions, exhibited more potently inhibitory effects on the proteasomal chymotrypsin-like activity than those without ester bond(s). Interestingly, the gallic acid and n-propyl gallate also had slightly inhibition on proteasome activities. Therefore, we suggest that the galloyl moiety might be the other important structure of polyphenols that contributes to the proteasome inhibition.
25
Jhuang, Han-Ying, and 莊漢英. "Enzyme Activities and Growth Inhibitory Effects of Human Nap1." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/an5u2y.
Full textAbstract:
碩士國立陽明大學
生化暨分子生物研究所
97
The neuramidase associated protein 1 (Nap1) is a novel human protein that shows high homology to nitrilase family. Nitrilases play important roles in lower organisms, as they hydrolyze amides to acids and ammonium and biosynthesize plant hormones required during seed development, and in industry, as they degrade otherwise bio-undegradable chemicals while the bioconversion is mild, clean, and highly selective. Nitrilases have accordingly gained much attention for its potential of being a biocatalyst for industrial chemical compounds. Intriguingly, nitrilase genes are highly conserved among species such as worm, fly, and human. In human, another nitrilase homolog have been identified – the nitrilase homolog 1 (Nit1), which functions as a tumor suppressor similar to Fhit. Whereas the human Nit1 has been identified as a tumor suppressor, functions of Nap1 remain elusive. Whether Nap1 drives enzymatic catalysis in human and, if true, the significance of it is still unknown. Here, by introducing C-terminally 6xHis-tagged human Nap1 gene into Escherichia coli (E.coli) and exploiting the nickel-charged sepharose gel system to purify the human Nap1 protein, we show that the Nap1 enzyme function is preserved in human as in lower organisms such as bacteria and plants using succinamic acid as the substrate. Further, we also show that Nap1-overexpressing cells exhibit growth inhibitory effects. To elucidate these effects, we examined the expression of several cell cycle regulators such as p53, p21, and 14-3-3σ. As a result, 14-3-3σ, a key cell cycle regulator, is upregulated in Nap1-overexpressing cells, while the S-phase regulator cyclin-dependent kinase inhibitor 1A (p21), or CDKN1A, and the tumor protein 53 (p53) and its inhibitor, MDM2, do not seem involved, in spite of the fact that 14 3 3σ is known to be a direct target of p53. In addition, phosphorylation form of the retinoblastoma protein (Rb), which regulates the G2/M cell cycle phase, is decrease in Nap1-overexpressing cells, indicating that Rb might as well participate in this effect. Furthermore, we show Nap1 interacts with Rb, suggesting that Nap1 might interfere Rb phosphorylation via interaction with it. Overall, these data could advance our understanding about Nap1, which may play a significant role that so far remain underestimated.
26
Chen, Siang-Jyun, and 陳香君. "Multiple Inhibitory Effects of Honokiol on Dengue Virus Infection." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/6yxrt5.
Full textAbstract:
碩士國立東華大學
生命科學系
102
Dengue fever is a common vector borne disease which is more prevalent in southern Taiwan. Till to date only one dengue vaccine has been succeeded in final stage of clinical trails, and no anti-dengue viral drugs are developed in clinical use. The only way for treatment of dengue patients is the supporting care. This study is aimed to investigate the potential anti-dengue viral activity of Honokiol derived from Magnolia officinalis of the Traditional Chinese Herbs. A lignan based compound, Honokiol is assayed against the serotype DENV-2 in two different cell types BHK and Huh7. The Honokiol has shown a substantial cell cytotoxicity against BHK and Huh7 cells with the cytotoxic concentration 50 (CC50) around 13.35 and 31.19 µM respectively, exhibiting the anti-dengue viral potency with the effective concentrations about 10 and 20 µM in DENV-2 infected BHK and Huh7 cells. To uncover the inhibitory mechanisms mediated by Honokiol, DENV replicon luciferase reporter system was applied and the relevant luciferase activity reflected a dose-dependent inhibition of viral translation or replication after Honokiol treatment. To further confirm the anti-viral effect of Honokiol on DENV infection, the expression levels of DENV-2 non-structure protein 1 (NS1), NS3 and the viral double stranded RNA (dsRNA) were examined by immunofluorescence staining and the results have showed an extreme reduction in NS1, NS3 and dsRNA expression. This results were in accord with the finding in DENV replicon system. Although Honokiol had showed no effect on virus receptor expression, it did decrease the colocalization of DENV envelope proteins with early endosome in a dose dependent manner. To examine the effect of Honokiol on cell functions that affecting DENV infection, cell cycle analysis was conducted and the results only showed a moderate cell cycle arrest at G0/G1 phase. In addition, Honokiol treatment did not activate NFκB nor induce the production of interferon-beta, which could be the major factors affecting DENV infection. In conclusion, this data collectively suggest that Honokiol has multi-diverged effects on DENV virus entry, translation, replication and particle production which substantiates that it has a great potential in anti-viral drugs development.
27
Ching-Chih and 陳敬之. "The inhibitory effects of safrole on human gingival fibroblasts." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/05131493396909831564.
Full textAbstract:
碩士中山醫學大學
口腔醫學研究所
95
The habit of areca (betel nut, Areca catechu) quid chewing is widespread in Taiwan, Southeast Asia, and India. Epidemiological studies have shown that areca quid chewing increases the risk of oral cancer and oral submucous fibrosis. In addition, areca quid chewers have a higher prevalence of periodontal diseases than non-chewers. In this study, the pathological effects of safrole, a major polyphenol compound in Piper betel leaf used when quid chewing, were investigated in cultured human gingival fibroblasts (HGFs). Little is known about the cytopathological effects of safrole on human gingival fibroblasts (HGF). Hence, we established 6 primary human gingival fibroblast strains for cell migration, attachment and spreading assays with the treatment of safrole. In addition, HGFs were challenged with safrole analyzed by 3-(4,5-dimethylthiazol-z-yl)-2,5-diphenyl-tetrazolium (MTT) colorimetric assay, Western blotting, gelatin zymography and casein zymography. Our results demonstrated that safrole was cytotoxic to HGFs in a dose-dependent manner (p<0.05). Safrole also inhibited cell attachment (p<0.05). A control culture exhibited a normal fibroblast monolayer of long spindle-shaped morphology. Safrole-treated HGFs showed a rounded appearance and detachment at higher concentrations. At concentrations higher than 20 µg/ml, safrole inhibited cell spreading and migration. Safrole was found to induced extracellular signal-regulated protein kinase phosphorylated (p-ERK) in a dose dependent manner.(p<0.05) Matrix metalloproteinases-2(MMP-2) and t-plasminogen activator(t-PA) expression was up-regulated by safrole treatment with time-dependent effect compare with control groups (p<0.05). Cyclooxygenase-2(COX-2) expression was increased by safrole (p<0.05). The addition of periodontal pathogens and proinflammation cytokines significant enhanced MMP-2 and t-PA expression (p<0.05) as compare with safrole alone. Taking together, these results indicate that safrole is a cytotoxic agent to HGFs. Areca quid chewers might be more susceptible to destruction of periodontium and less responsive to a regeneration procedures during periodontal therapy.
28
Weng, Yu-Ting, and 翁于婷. "Melanogenesis Inhibitory effects of CPC regulation of MAPK pathway." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/82641751947639627204.
Full textAbstract:
碩士國立暨南國際大學
生物醫學科技研究所
96
An increased level of melanin is one of the characteristics of several skin diseases, including acquired hyperpigmentation such as melasma, postinflammatory melanoderma, and solar lentigo. Tyrosinase catalyzes the rate-limiting reaction of melanogenesis. The formation of melanin is regulated by the activity or the expression of the enzyme. Although the whole picture of the signal transduction involved in melanogenesis remains unclear, it is suggested that cAMP plays an important role in the biosynthesis. cAMP modulates melanogenesis in three aspects. Firstly, cAMP regulates the activation of protein kinase A, which phosphoylates the transcription protein, CREB. Phosphoryed CREB further facilitates the expression of microphthalmia associated transcription factor (MITF), which is the transcription factor of tyrosinase. Secondly, cAMP induces MITF degradation through the activation of ERK, and therefore, down-regulates the expression of tyrosinase. Thirdly, cAMP inhibits the activation of phosphatidylinositol 3-kinase (PI3K), which results in the repression of protein kinase B (Akt) expression, yet up-regulates MITF. Melanogenesis involves a series of redox reactions. Antioxidants such as ascorbic acid, retard melanogenesis through reduction of oxidized intermediates. C-phycocyanin (CPC), a component of blue green algae, has been studied to have anti-oxidative capacity and free radical scavenging activity. In the present study, the results showed that B16F10 melanin content and tyrosinase expression were reduced by the addition of CPC. In addition, CPC increased cAMP level and protein kinase A (PKA) activity. CPC were uptaken and trapped in cell nuclei to inhibit melanogenesis possibly the through suppression of the PKA pathway.
29
Lai, Wen Tzu, and 賴文子. "Preferential inhibitory effects of abrin A-chain-EGF fusion." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/67112426169505742688.
Full textAbstract:
碩士國立臺灣大學
生化學研究所
85
Abrin is composed of an A-chain linked by a disulfide bond to a B-chain. The B-chain is a lectin, and the A-chain contains glycosidase activity to act on eukaryotic 28S ribosomal RNA. Elevated expression of the receptor for epidermal growth factor ( EGF ) is a characteristic of several malignan cies including those of the breast, brain, prostate, lung, and neuroglia. T o therapeutically target the cytotoxic action of abrin to EGF receptor-expressing tumor cells, we constructed a chimeric toxin. This study describes the genetic construction,expression, purification and properties of an abrin A-chain-EGF fusion gene in which abrin A-chain was genetically fused with a human EGF coding region. Fusion protein expressed from the chimeric glutathione S-transferase gene was designated GAE and overexpressed in Escherichia coli. This fusion toxin has a molecular mass of 60kDa. A single-step purification of the fusion protein was performed by glutathione-Sepharose 4B column. The immunotoxin retained the ribosome-inactivating activity of the A-chain. We examined its cytotoxicity to A431 cells and HeLa cells. Present investigation showed that human cancer cells containing more EGF receptors like A431 cells are more sensitive to GAE than these containing less EGF receptors such as HeLa cells.
30
Yu-JenHuang and 黃裕仁. "Inhibitory effects of specific nitrification inhibitors on ammonia oxidizing archaeal community enriched under high and low salinity environments." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/82269248652378435495.
Full textAbstract:
碩士國立成功大學
環境工程學系碩博士班
101
Nitrification is a key step in biological nitrogen removal process, and ammonia oxidation had been considered as rate limit step in nitrification process. It was believed that ammonia oxidizing bacteria (AOB) were the main group responsible for ammonia oxidation however, several new ammonia-oxidizing organisms belonged to the archaeal domain were found also involving in ammonia oxidation had changed this view. Archaea was thought to have advantages over bacteria in extreme environments, such as harsh temperature, pH, and the existence of toxic chemicals. Therefore, it was considered that ammonia oxidizing archaea (AOA) may play more important role than ammonia oxidizing bacteria on ammonia oxidation in specific environment. Many chemicals, existing in wastewater treatment process, reported to inhibit ammonia oxidizing bacteria on ammonia oxidation activity. However, there is much less information about those chemicals inhibition effects on ammonia oxidizing archaea. Different responses of ammonia oxidizing archaea and bacteria to inhibitive chemicals would provide alternative choices for wastewater treatment process. Therefore, it is very important to establish the inhibition information of AOA. In this study, two laboratory-scale reactors were operated under high (34‰) and low salinity (2.5‰) respectively, which both contain high level of AOA enrichments were used to evaluate the resistance of AOA to specific nitrification inhibitors by batch tests. Three different types of specific nitrification inhibitors were chosen in this study, including aromatic hydrocarbon, organic sulfur compound and organic nitrogen compound, in order to systematically investigate the impact of ammonia oxidation on AOA. In the batch tests, all of selected specific nitrification inhibitors had different levels of inhibitory effect on AOA enrichments in high and low salinity condition. Benzene and Toluene decreased over 60% of ammonia oxidation activity on AOA during batch tests. The batch tests with phenol were found that AOA in low salinity condition had high resistance to phenol than ammonia oxidizing bacteria. AOA in high and low salinity condition had decreased ammonia oxidation activity under long-time exposure to DMS and ATU. In the batch tests with organic nitrogen compound, the ammonia oxidation activity of AOA significantly decreased with increasing concentrations of EDA and pyridine. The inhibitory effect on AOA in high and low salinity sludge might have more tolerance to specific nitrification inhibitors than nitrifying community.
31
Su-Ru and 林素如. "Study of the inhibitory effects and mechanisms of Acacia confusa trypsin inhibitor on lung cancer invasion and migration." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/04224352992421382454.
Full textAbstract:
碩士中山醫學大學
生化暨生物科技研究所
95
The invasive ability of tumor cells is a key factor for metastasis and a major cause for treatment failure. Although trypsin inhibitor have been widely recognized to possess several potential as cancer chemopreventive agents, however, limited studies have been available concerning the inhibitory effects of these protein for tumor metastasis. Here, we demonstrated that Acacia confuse trypsin inhibitor (ACTI) could significantly inhibit the invasion, motility, cell-matrix adhesion, secretion of matrix metalloproteinase (MMP)-2, -9, or urokinase-type plasminogen activator (u-PA) of lung cancer cells (A549, H1299, and Lewis lung carcinoma (LLC)). To investigate the possible mechanisms involved in these events, we performed Western blot analysis to find that ACTI inhibited phosphorylation of ERK1/2 and Src, but had no effects on the phosphorylation of p38 and Akt. A treatment with ACTI to A549 cells also inhibited the expression of NF-kB and c-Fos in nuclear extract as shown by Western blot. ACTI inhibited the phosphorylation of ERK1/2, the activity of MMP-9 and cell invasiveness after 12-O-tetradecanoylphorbol-13-acetate (TPA) induction. Finally, these compounds were evidenced by its inhibition on the tumor growth of LLC cells in vivo. Taken together, these findings suggested that ACTI could reduce the invasion and metastasis of lung cancer cells in vivo and in vitro, thereby constituting an adjuvant treatment for metastasis.
32
Omar, Amer Y. "Effects of inhibitory Smad7 on P1 primary cardiac myofibroblast proliferation." 2005. http://hdl.handle.net/1993/20690.
Full text
33
Yan, Guey-Fen, and 顏桂芬. "Inhibitory effects of phenolic carboxylic acid analogues on xanthine oxidase." Thesis, 1995. http://ndltd.ncl.edu.tw/handle/44913666564823127553.
Full textAbstract:
碩士國立臺灣大學
藥學研究所
83
Part I. Xanthine Oxidase Inhibitors from Ophioglossum petiolatum Hook.Ophioglossum petiolatum Hook. (Ophioglossaceae) has been used in folk medicine for inflammation, various pains, tumors, jaundice, fever. In the search for active principles, the rhizoma of the plant were extracted with ethanol. Two flavonoids, quercetin-3- methylether (OP-1) and 3- hydroxymethylluteolin (OP-2) were isolated and characterized from the ethyl acetate soluble fraction of the ethanolic extract. Each fraction and compounds OP-1 and OP-2 were tested for their inhibitory effects on xanthine oxidase. The tests showed that the ethyl acetate fraction of ethanolic extract and the purified compounds OP-1 and OP-2 displayed quite potent effects on xanthine oxidase inhibition. Part II. Inhibitory Effects of Phenolic Carboxylic Acid Analogues on Xanthine Oxidase Nineteen phenolic carboxylic acid analogues were tested for their inhibitory effects on xanthine oxidase. The results showed that 2, 2', 4, 4'- tetrahydroxybenzophenone displayed the strongest activity (IC50 = 38.70 mM) and 2, 3, 4- trihydroxybenzoic acid was the next (IC50 = 90.16 mM). In the study of superoxide anion scavenging activity in xanthine-xanthine oxidase-cytochrome C system, most of the phenolic carboxylic acid analogues tested displayed the scavenging effects of superoxide anion, especially gentisic acid and protocatechuic acid.
34
Yu, Yu-Wen, and 尤郁雯. "Inhibitory Effects of Natural Botany Resources on Human Glioma Cells." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/75669417272517935226.
Full textAbstract:
碩士臺北醫學大學
生藥學研究所
97
Gliomas are the most common type of primary brain tumor. Nearly two-thirds of gliomas are highly malignant lesions that account for a disproportionate shape of brain tumor-related morbidity and mortality. Approximately 17,000 primary brain tumors are diagnosed every year, and of those, about 60% are gliomas. Anaplastic astrocytoma (AA, grade III) and glioblastoma multiforme (GBM, grade IV), the high grade gliomas, are the most common type hence we employed the human malignant glioma cell lines of U87 MG (III) and GBM 8401 (IV) as target to examined antiproliferation activity by MTT reduction. Brain tumor therapy usually gets surgical resection for the first priority and followed by radiotherapy and chemotherapy. All brain tumor therapies now usually result in the poor prognosis. Especially, radiotherapy and chemotherapy would generate free radicals, kill not only cancer cells but also healthy cells. Recent studies have demonstrated that antioxidant could enhance the therapeutic effects, decrease the side effects and protect normal tissue damage. Phytochemicals are plant-derived compounds under scientific research for potential health promoting properties and recurrence of cancer. Epidemiological and preclinical evidence suggests that polyphenolic phytochemicals possess cancer chemopreventive properties. In this study, a high through screening method was established to investigate 60 kinds of natural botany resource on anti-brain tumor activity. YY-02 methanol extract (ME) is the most efficacy of antiproliferation on human malignant glimoas. Furthermore, ME was fractionated with n-hexane (HeF), ethyl acetate (EA), acetone (AcF) and methanol (MeF). Outcomes of total polyphenol, flavonoid content, and DPPH radical scavenged, chelated ferrous ion, lipid peroxidation (LPO) inhibition of liver, kidney and brain tissue measurement, that exerted the MeF is a highest potential fraction in YY-02. Otherwise, view of morphological assay and cell cycle analysis, YY-02 exhibited the cell death pathway by apoptosis. In conclusion, YY-02 is a phytochemical of chemotherapy agents on brain tumor.
35
chia-hua, Lin, and 林佳樺. "Studies of the inhibitory effects of HE-145 on NFkB." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/04546014577289342149.
Full textAbstract:
碩士國立陽明大學
生物化學研究所
90
ABSTRACT Most vaccines and infection reactions are related to nuclear transcription factors kB (NFkB). When cells process different kinds of inducers that dissolve IkB, they release NFkB into the cell nucleus, inducing different gene expressions to regulate infection reactions. From the knowledge of previous laboratory research, it is known that HE-145, which is lignan extracted from the heartwood of Taiwania cryptomerioides Hayata, can prevent the presence of Hepatitis B virus in the cell medium. It is also known that HE-145 causes inhibition effects in the mRNA of HBV surface antigens. Other than inducing humans to produce a regulatory factor named cyclin A, HE-145 can also inhibit the basal level in cells through the activity of the NFkB promoter, which is stimulated by TNFa. Thus, we would like to examine whether HE-145 has a specific inhibition effect on TNFa-stimulated NFkB. Moreover, if there is a specific inhibition effect, we would like to examine why HE-145 and what about HE-145 supplies the ability to inhibit TNFa-stimulated NFkB. Using transfection as a mode of investigation in Hep3B/T2 and 293T cells, HE-145 displayed no effect whatsoever on other NFkB inducers, such as Adriamycin, MEKK, PKCd, GSK-3; hence we can assume that HE-145 poses as a strong and possible candidate in causing specific inhibition effects on our particular NFkB inducer, TNFa. In 293T cells, HE-145 inhibits the following NFkB-inducing components of the signal transduction pathway by which TNFa activates NFkB: TRADD, IKK-b, p65, p50, and c-REL. In Hep3B/T2 cells, He-145, via dose-dependent inhibition, only controls NFkB through two inducers: IKK-b and p65. On the other hand, knowledge acquired through immunofluorescence stains and Western blots reveals that HE-145 exhibits inhibition ability through translocation to the cell nucleus. However, the exact function of HE-145 toward the inhibition of TNFa-induced NFkB still calls for further research. Given the results obtained through the above investigation, we know that HE-145 is indeed a NFkB inhibitor and such conclusions will undoubtedly prove useful as the foundation for future developments in new drug treatments for HBV and human hepatoma cures.
36
Lin, Yu-Wen, and 林郁雯. "Antioxidant activities and xanthine oxidase inhibitory effects of medicinal plants." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/81024570021173713106.
Full textAbstract:
碩士國立臺灣大學
農藝學研究所
103
With the economy standards improved, people in Taiwan have changed in eating habits and decreased physical activity, so there is a substantial increase in the prevalence of chronic diseases. It is increasingly starting to pay attention to health care. Natural medicinal plants used in the past by various ethnic groups in the treatment of disease, and many of today''s medicine and health food are extracted from the active ingredient purified or re-modified derived of natural medicinal plants. Although the current study have known for a number of medicinal plants, but there are still a lot of medicinal plants whose health benefits have not yet been discussed or studied. In this study, with the health potential of local medicinal plants: noni tree (Morinda citrifolia L.), cummingcordia (Cordia dichotoma Frost f), perilla (Perilla frutescens), and citrus peels as plant material, measured pigment and secondary metabolite contents, and four kinds of health functional assay: ferrous ion chelating ability, DPPH radical scavenging, reducing power and xanthine oxidase inhibition activity, and do the correlation and grey relational analysis. Our results show that the potential ethanol extracts is perilla leaves, it is the best plant material of antioxidant activities and the supreme all metabolites content. Due to prolonged soaking solvent storage, therefore, phenols, flavonoids and anthocyanin content reduced, the amount of chlorophyll becomes critical antioxidant capacity. In the result of grey relational analysis, chlorophyll a, total chlorophyll and chlorophyll b are the greatest impact plant metabolites for antioxidant capacity. The metabolite content and antioxidant capacity of leaves will be better than other parts due to leaves rich in chlorophyll, so leaves of noni and cummingcordia therefore also become quite potential. Analysis in different parts of the pomelo fruit, we can get the key of health effects in citrus fruits is peels. Further analysis in other kinds of citus peels, we find the health effects of mandarin peels and lemon peels just behind perilla leaves, which may be due to the many important phenols and flavonoids in citrus peels. In conclusion, in the ethanol extracts, we get these plant materials: perilla leaves, mandarin peels, lemon peels, and noni leaves having the potential in further study, and also having good health benefits. Moreover, the applications of mandarin peels, lemon peels can solve some problems of agricultural waste and increase their added value. The results of this study can give some information for further analysis of medicine, food, health care research to find the key health ingredients in these medicinal plants.
37
Lin, Chiu-Mei, and 林秋梅. "Inhibitory Effects of Wogonin and Chrysin on Inflammation-stimulated Angiogenesis." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/27072357721909907527.
Full textAbstract:
博士國立陽明大學
傳統醫藥學研究所
94
Angiogenesis plays an important role in many human disorders, such as tumor formation and myocardial infarction. In angiogenesis, vascular endothelial growth factor (VEGF) plays a central role and present in response to inflammation, shear stress, and hypoxia. VEGF is involved in the endothelial cell proliferation, motility, and vascular permeability through the binding with the tyrosine kinase receptors (VEGFR-1 and VEGFR-2) expressed in endothelial cells. Several transcription factors, including STAT3, have been shown to up-regulate VEGF gene expression in different cells. Nevertheless, the role of STAT3 in the VEGF regulation on endothelial cells remains unclear. Although, the interplay between IL-6 and VEGF, has been shown in various kinds of cells. The relationship between IL-6 autoregulation and angiogenesis remains to be clarified. In the present investigation, the effect of herbal medicine on anti-angiogenesis remained unclear. Wogonin and chrysin, two pure compounds of Scutellaria baicalensis Georgi, possess potent anti-inflammatory, antimicrobial and anti-oxidant effects. Nonetheless, the role of wogonin or chrysin in angiogenesis, and the potential molecular mechanisms in angiogenesis have not been studied. The aim of this study was to investigate the effects of wogonin and chrysin on LPS- or IL-6-stimulated angiogenesis. By the treatment with wogonin or chrysin, added into LPS- and IL-6 primarily cultured human umbilical endothelial cells (HUVECs) respectively, the phenotypic alterations were evaluated. Moreover, Western blot analysis, ELISA cytokine assay, immunoprecipitated Western blot analysis and quantitative real time-PCR were performed for IL-6/IL-6R and VEGF/VEGFR gene expressions in vitro. By introducing the targeted siRNA for STAT3, the downstream VEGF signal modulation was also examined. The chicken chorioallantoic membrane (CAM) was applied to test the effects of wogonin and chrysin on LPS- or IL-6-stimulated neovascularization in vivo. The results indicated that wogonin and chrysin (10-8~10-5M) inhibited LPS- or IL-6-stimulated angiogenesis in a concentration-dependent manner in CAM assay. Consequently, negative activation of the mRNA transcription of VEGF/VEGFR-1 and sIL-6Rα/JAK1/STAT3 signaling, as well as the VEGFR-1/VEGFR-2, IL-6, sIL-6Rα, gp130/JAK1 complex protein, were attenuated on wogonin- and chrysin-treated IL-6-stimulated HUVECs, respectively. Besides, another intracellular PKC pathway and alternative intracellular IL-6 receptor signaling pathway, ERK 1/2, were also test and revealed the significant attenuation. Moreover, by introducing targeted siRNA for STAT3, downstream VEGF protein was suppressed on wogonin- and chrysin-treated IL-6-stimulated HUVECs. Taken together, the data conclude that wogonin and chrysin suppress the autoregulation loops of IL-6/IL-6R and VEGF/VEGFR through down-regulation of STAT3, PKC and ERK 1/2 phosphorylation, and hence inhibits LPS- or IL-6-stimulated angiogenesis. Significantly, wogonin and chrysin were demonstrated to be potential anti-angiogenic agents. The results would bring into perspective the clinical implication for inflammation-related over-angiogenic diseases.
38
Hsu, Hua-Chien, and 徐華謙. "Inhibitory effects of Chinese medical herb extractson melanogenesis and browning." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/97401068281668258539.
Full textAbstract:
碩士輔英科技大學
生物科技系碩士班
99
In this study, the inhibiting effects on melanogenesis of seven Chinese medical herb extracts, including Trichosanthes, leaves and roots of Scutellaria barbata, Trigonella, Saliva miltiorrhiza, Angelica dahurica, Agastache rugosa were evaluated. Our results indicate that of all extracts, the leaves of Scutellaria barbata displaied the best inhibiting effects on both melanogenesis and tyrosinase activies. The extract of Trigonella, however, has no any inhibiting effect on either melanogenesis or tyrosinase activies. It is generally found that the low concentrations used the low effectiveness of inhibition on melanogenesis and tyrosinase activies, indicating that the decrease in cell growth did not significantly affect the decrease in melanogenesis and/or tyrosinase activies. For the ability of anti-brown, the extracts of Scutellaria barbata including leaves and roots, Agastache rugosa or T. Kirilowii Maxim could inhibit the browning effect of mushroom.
39
Ghara, Gozli Davood. "Facilitatory and Inhibitory Effects of Implicit Spatial Cues on Visuospatial Attention." Thesis, 2011. http://hdl.handle.net/1807/30605.
Full textAbstract:
Previous work suggests that both concrete (e.g., hat, shoes) and abstract (e.g., god, devil) concepts with spatial associations engage attentional mechanisms, affecting subsequent target processing above or below fixation. Interestingly, both facilitatory and inhibitory effects have been reported to result from compatibility between target location and the meaning of the concept. To determine the conditions for obtaining these disparate effects, we varied the task (detection vs. discrimination), SOA, and concept type (abstract vs. concrete) across a series of experiments. Results suggest that the nature of the concepts underlies the different attentional effects. With abstract concepts, facilitation was observed across tasks and SOAs. With concrete concepts, inhibition was observed during the discrimination task and for short SOAs. Thus, the particular perceptual and metaphorical associations of a concept mediate their subsequent effects on visual target processing.
40
"Inhibitory and facilitatory effects on the perception of repeatedly presented stimuli." 1997. http://library.cuhk.edu.hk/record=b5889345.
Full text
41
Ko, Chi-Mei, and 柯智美. "The Inhibitory Effects and Application of Essential Oils on Mushroom Tyrosinase." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/83nkvq.
Full textAbstract:
博士靜宜大學
應用化學研究所
97
In this study , the active constituent of 52 essential oils were isolated by the process of tyrosinase activity assay. The results showed that 29 essential oils showed potent inhibitory effects. It was found that the tyrosinase inhibitory activities of all the extracts increased with the increase of their concentrations. The inhibition kinetics, analyzed by Lineweaver–Burk plots, revealed that essential oil showed a mixed-type noncompetitive inhibition for mushroom tyrosinase when L-Dopa was used as substrate. A comparison of the IC50 showed that Lemongrass exhibited the most effective inhibition of tyrosinase among the essential oils. Lemongrass,Eucalyptus,Melissa,Niaouli essential oils exhibited the higher inhibitory effects and good odors。And they were formulated into the skin lotion and showed the skin whitening effects 。 Inhibitory activities of the essential oils as follows： Lemon＞Rosewood＞Orange Bitter Flower＞Chamomile Roman＞Marjoram Sweet In the complex essential oils. Lemon 80% exhibited the most significantly inhibitory activities。 Lemon,Rosewood and Orange Bitter Flower also exhibited the most significantly。 This study will help the whitening effects skin care products in the cosmetic science。It’s a good message and more safe in using whitening skin products for Asia womam。
42
Lee, Wen-Feng, and 李文峰. "The Inhibitory Effects of Progesterone on Human T Cell Proliferative Signals." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/965kar.
Full textAbstract:
碩士國立陽明大學
生理學研究所
90
Fetal alloantigens encoded by genes inherited from the father should provoke responses by maternal T cells leading to fetal loss. However, progesterone may be an immunomodulator is important for the survival of the implanting embryo and maintenance of early pregnancy. Our previous studies demonstrate that both Ca2+ influx and alkalinization are early proliferative signals in T cells activated by a mitogen, phytohemagglutinin (PHA). Progesterone, at concentrations found in placenta, inhibits the proliferation of lymphocytes by mitogens. The aim of this study was to investigate whether progesterone affected T cell activation signals on intracellular calcium ([Ca2+]I), pH (pHi) as to influence PHA-induced IL-2, IL-4 secretion, CD25, CD28, CD152 expression and proliferation. T cells were isolated from human peripheral blood. The [Ca2+]i and the pHi were measured using the fluorescent dyes, Fura-2 and BCECF, respectively. PHA was used as a control. The expressions of NFkB and IL-2Ra mRNA were analyzed by RT-PCR (reverse transcriptase-polymerase chain reaction). The expressions of T cell surface antigens, CD25, CD28, and CD152 (CTLA-4), were detected by the flow cytometry. The IL-2, IL-4 secretion were measured by ELISA (enzyme-linked immunosorbent assay). The proliferation was determined by [3H]-thymidine incorporation into T cells. The results indicated that 1) progesterone (100 mM) resulted in an elevation of [Ca2+]i in T cells within 15 min, from a resting level of 95.2±10.42 nM to 141.9±12.8 nM (n=10，p<0.001), and a decrease of pHi (acidification) within 30 min, from 7.312±0.077 to 6.952±0.079 (n=10，p<0.001). 2) The responses on acidification and the [Ca2+]i increase by progesterone were suppressed by progesterone antagonist, RU486. The [Ca2+]i increased by progesterone was dependent on Ca2+ influx, whereas, acidification was PKC、Ca2+、Na+-dependent. PHA did not affect progesterone-induced acidification, but progesterone could suppress PMA or PHA-induced alkalinization. 3) The peak expressions of NFkB and IL-2Ra mRNA were at 0.5 hr and 2 hr after progesterone administration. 4) PHA stimulated the expressions of CD25, CD28, CD152 and secretions in IL-2, IL-4, but progesterone could significantly suppress PHA-induced CD25, CD28 expression and IL-2, IL-4 secretion in T cells. 5) Progesterone alone did not influence [3H]-thymidine incorporation into T cells. However, progesterone could suppress PHA-induced [3H]-thymidine uptake. In conclusion, progesterone stimulates intracellular calcium elevation, acidification and NFkB mRNA expression but Inhibits PHA-induced alkalinization, IL-2, IL-4 secretion, CD25, CD28 expression and proliferation in T cells. These results implied that acidification by progesterone might be an essential mechanism to suppress PHA-induced T cell activation.
43
Peng, Wei-Hsin, and 彭維昕. "The Inhibitory Effects of β-Lapachone on the Inflammation-Induced Fibrosis." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/e3xh4u.
Full textAbstract:
碩士國立臺灣大學
解剖學暨細胞生物學研究所
103
Introduction Inflammatory response plays an important role in many diseases, and it could also cause fibrosis in many tissues or organs, which include heart, lung, liver and kidney. Fibrosis is led by excess collagen and extracellular matrix (ECM) which produced by fibroblasts. Most researches about inflammation are focused on macrophages, but the inflammation on fibroblasts is under the mist. Therefore the study aimed to study the inflammation induced by LPS in fibroblasts. It is important to inhibit the inflammation-induced fibrosis by blocking the collagen production in fibroblasts. β-Lapachone (β-Lap) is a kind of pharmacodynamics complex extracted from Tabebuia avellanedae, and the studies show the effective function of β-Lap might be regulated by NQO1 enzyme(NAD(P)H:Quinone Oxidoreductase 1 ). Accordingly, we assume that if β-Lap could reduce the inflammation on fibroblasts, it might decrease the situation fibrosis through lowering the overwhelming collagen product in fibroblasts. Material and Methods NIH3T3 cell line was used in this study with different concentrations of β-Lap under lipopolysaccharide (LPS) treatment, the inflammation inducer, to observe the mechanisms of LPS-induced inflammation in fibroblasts and whether β-Lap could protect cells from inflammation-induced collagen production and fibrosis. We examined the cell viability by crystal violet and observe the protein expression of COX-2 (Cyclooxygenase-2), NF-κB(Nuclear factor kappa-light-chain-enhancer of activated B cells), α-SMA (Alpha smooth actin), COL1A1 and COL3A1 (type I and type III collagen) by western blotting and immunocytochemistry(ICC). Results In our study all the drugs we used in the experiments would not affect the viability of fibroblasts. We found that COX-2 and p-p65 (NF-κB subunit) expression increased and collagen products were enhanced through LPS stimulation of LPS. And CLI-095, TLR4 inhibitor, was used to confirm the specific receptor of LPS on fibroblasts. The study also checked the pathway of inflammation through the inhibitor of NF-kB and COX-2. In addition, we found that β-Lap could reduce the level of inflammation and fibrogenesis induced by LPS. Besides, the study also demonstrated that LPS lowered the ratio of NAD+/NADH, and the treatment of β-Lap could retain it. Conclusions Direct stimulation of LPS lead inflammation in fibroblasts, and induced overwhelming collagen production. The treatment of β-Lap could reduce the inflammation and fibrogenesis significantly. In consequence, β-Lap has the huge potential to become the clinical treatment on the inflammation-induced fibrosis.
44
Fu-Chi and 林富祺. "Inhibitory effects of diosgenin on the proliferation of breast cancer cells." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/16516846452231773272.
Full textAbstract:
碩士中山醫學大學
生化暨生物科技研究所
98
Diosgenin, a steroidal sapogenin, is similar to estrogen. It has been reported to have anti-inflammation and hypolipidemic effects, and it can inhibit proliferation and induce apoptosis in several human cancer cells. The mechanisms of anti-proliferation induced by diosgenin in breast cancer cell are not understood, we therefore treated breast cancer cell lines Hs578T and MCF7 with diosgenin. In our experiments, diosgenin caused DNA damages including double-strand break in breast cancer cell lines Hs578T and MCF7. We discovered that diosgenin reduced the expressions of cyclin D1 and Cdk4 protein, and induced G1 phase cell cycle arrest through activations of chk1, p53 and p21. We want to know whether diosgenin can affect non-homologous end-joining repair (NHEJ repair) when DNA double-strand break occurs. In outcome, diosgenin don’t influence the expressions of ku70 and ku80 in NHEJ enzymes. In addition, we add the protein kinase inhibitor (UCN-01) and diosgenin to treat breast cancer cell lines. This study suggests that breast cancer cells treated with diosgenin and UCN-01 reduced cell viability and induced G1 phase cell cycle arrest through the inhibition of cyclin D1 and cdk4. We infer that UCN-01 and diosgenin may have synergy to inhibit the proliferation of the breast cancer cells, but the detailed mechanisms are not understood. The addition of UCN-01 reduced the expression of ku80 in NHEJ enzyme in breast cancer cell Hs578T. That whether is related to synergy of UCN-01 and diosgenin still is needed to confirm.
45
Kung, Hua-Ting, and 宮華婷. "Colostrum’s Immunomodulatory Activities and Inhibitory Effects on Human Leukemic U937 Cells." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/03593196718519624834.
Full textAbstract:
碩士國立臺灣大學
食品科技研究所
94
Colostrum is breast milk produced after giving birth and lasts for 2-4 days. Bovine colostrum contains essential nutrients, growth factors, antimicrobial compounds and immune-regulating constituents either not present in milk or present in substantially lower concentrations. Colostrum is thought to protect neonates from infection, as well as to facilitate the immune maturation. In this study the immunomodulatory activities and anti-proliferation effect of human lukemic cell U937 were being invested. Results suggested that colostrum collected on day 1 and 2 after onset of lactation enhanced the growth of peripheral blood mononuclear cells (MNCs) in a dose dependent manner and significantly increased the population of T cell、Tc cell and NK cell. Moreover, day 1 to day 4 colostrums were capable to induce MNCs to secrete IL-1β, IFN-γ and TNF-α, which subsequently inhibited the growth of U937 cells and further induced it’s differentiation into mature monocytes or macrophages. Lactoferrin is the most prominent immunomodulatory factor within colostrum. It has been proven that lactoferrin is at its maximum in the colostrum obtained at parturition and gradually decrease with time course of lactation. The present investigation demonstrated that lactoferrin, even at very low concentration, could enhance the growth of PBMC. However, its effect on growth inhibition of U937 was not significant. In addition, when colostrum was fractionated by acid precipitation, the MNC growth effect was found in the precipitated fraction containing lactoferrin.
46
Lin, Shu-Mei, and 林舒美. "Inhibitory effects of marine microalgae on the multiplication of Vibrio alginolyticus." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/22033047651381137167.
Full textAbstract:
碩士國立臺灣海洋大學
水產養殖學系
93
Abstract The purpose of this study is investigated the relationship of algae and bacteria in the seawater, and also want to know the effect of microalgae inhibit bacterial or not. Five species of microalgae, Skeletonema costatum, Chaetoceros muelleri, Tetraselmis chui, Nannochloropsis oculata and Isochrysis galbana were used to study the inhibition of Vibrio alginolyticus growth with microalgae live cell and intracellular products in different concentrations, based on biological characteristic (log phase of growth curve and relationship of cell count and absorbance). The size of microalgae showed that a negative correlation with the highest cell count in log phase, growth rate was found highest in N. oculata, follow by I. galbana, C. muelleri, S. costatum and T. chui, respectively. All species were found effectively depressed the growth of V. alginolyticus. Moreover, a completely inhibit of V. alginolyticus was found in I. galbana and C. muelleri. On the other hand, different concentrations of S. costatum can inhibit V. alginolyticus growth, only.
47
Kan, Shu-Fen, and 甘淑芬. "Inhibitory Effects of Evodiamine on the Growth Human Prostate Cancer Cells." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/83094291048211820811.
Full textAbstract:
博士國立陽明大學
生理學研究所
92
英文摘要 Prostate carcinoma is one of the most common malignant tumors and the second cause of cancer related death among men in the United States. During the past 10 years, prostate carcinoma becomes a more common cancer in men in Asia includung Taiwan. Evodiamine, isolated from Chinese herbal drug named Wu-Chu-Yu, possesses many biological functions. Recently, it has been reported that Wu-Chu-Yu exerts an antiproliferative effect on several cancers. In the present investigation, several experiments have been designed to explore the action mechanism(s) of evodiamine on the growth of prostate cancer cell lines including LNCaP, DU145, and PC3. Prostate cancer cells were challenged with evodiamine for 24, 48, 72, 96 hours. The cell growth has been measured by MTT assay. The cytotoxic effects of evodiamine have been analyzed by lactate dehydrogenase activity assay. The change of cell cycle distribution and induction of apoptosis caused by evodiamine were examined by flow cytometry. To investigate the cellular mechanism(s) that caused by evodiamine, the techniques of TUNEL assay, Western blot, immunoprecipitation, kinase assay were employed. The data have been analyzed by ANOVA and Duncan''s multiple-range test. Results indicated that cell proliferation rate was significantly inhibited by evodiamine. Evodiamine elevated the cytotoxicity in prostate cancer cells. The flow cytometric analysis of evodiamine-treated cells indicated a block of G2/M phase and an elevated level of DNA fragmentation. The G2/M arrest was accompanied by elevated cdc2 kinase activity, an increase in the protein expression of cyclin B1 and phosphorylated form of cdc2 (Thr 161), and a decrease in the protein expression of myt-1 and phosphorylated form of cdc2 (Tyr 15). Examination of TUNEL showed that evodiamine-induced apoptosis was observed at 24 h and extended to 72 h. Evodiamine elevated caspase 3, caspase 8, and caspase 9 activities in DU145 and LNCaP cells, and only caspase 3 and caspase 9 activities in PC3 cells. Evodiamine also caused the processing of caspase 3 and caspase 9. These results suggested that evodiamine inhibited the growth of prostate cancer cells including LNCaP, DU145 and PC3 through an accumulation of cell cycle at G2/M phase and an induction of apoptosis. We expect that these results will provide a new strategy for therapy of prostate carcinoma in human beings.
48
謝曉惠. "The Inhibitory Effects on Tumor Cell by the Herbal Fermentation Products." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/35284859738017398782.
Full textAbstract:
碩士南台科技大學
生物科技系
92
The Antrodia camphorata （Zhan-Ku） is a new obligately fungal parasite on the heartwood layer of endemic camphor tree ( Cinnamomum kanehirai Hay ) in Taiwan. It’s recognized as traditional herb being able to enhance liver function and anti-fatigue. Nowadays the related studies has confirmed it’s function of suppressing hepatitis virus activeness, and to alleviate the body and mind to be exhausted and the suppression of cancer cell growth and so on. Most of the past studies were focused on bioactivities of liquid state fermentation of Antrodia camphorata .This study mainly focuses on solid state fermentation of Antrodia camphorata .Several kind of herbs including Semen cassiae, Radix isatidis, Herba houttuyniae, Hedyotis diffusa Willd and Panax notoginseng were selected as substrate and fermented by Antrodia camphorata . Extracts of these fermented products were analyzed by HPLC to analyze the metabolic profile. The MTS test was performed to demonstrate their cytotoxicity. After solid state fermentation, all of the fermented herbs show strong anticancer activity, and different herb has various levels of inhibitory activity to different cell lines. Extracts of solid state fermented products shows stronger anticancer activity than mycelium those from liquid fermentation. These results demostate that herbs fermented by Antrodia camphorata may be biotransformed to specific compounds which have strong cytotoxicity to cancer cell lines. More efforts should be made in the future to determine their components and anticancer mechanisms.
49
Li, Hsin-yi, and 李信億. "Inhibitory effects of a crude extract from Magnolia officinalis on melanogenesis." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/16537867122595577590.
Full textAbstract:
碩士國立臺南大學
生物科技學系碩士班
99
In the present study, we investigated the inhibitory effect of a crude extract from Magnolia officinalis (MOE) on melanogenesis in both mouse B16 melanoma cells and zebrafish. Our results showed that MOE inhibited melanogenesis in either melanocyte stimulating hormone (??MSH) or 3-isobutyl-1-methylxanthin (IBMX)-stimulated B16 cells in a dose-dependent manner with an IC50 value of 9.3 ?慊/ml. In addition, MOE also inhibited cellular tyrosinase activity with an IC50 value of 13.4 ?慊/ml while no inhibitory activity was found by MOE against cell-free tyrosinase activity. Moreover, western blotting and real time reverse-transcription polymerase chain reaction (qRT-PCR) analyses respectively confirmed that MOE downregulated levels of tyrosinase protein but not that of its mRNA in ??MSH- stimulated B16 cells.These results demonstrated that MOE inhibits melanogenesis of B16 cells by a post-transcriptional regulation on tyrosinase gene expression. In the other hand, when using zebrafish as a depigmenting assay system, MOE could inhibit both melanogenesis and tyrosinase activity in the in vivo model. From the present study, MOE was proven to be a good candidate as a skin-whitening agent for treatment of skin hyperpigmentation. Keywords: Magnolia officinalis, Melanogenesis, Tyrosinase, Melanin, Inhibition
50
Tsai, Sheng-Hui, and 蔡聖輝. "Effects of Sub-inhibitory concentrations of aminoglycoside antibiotics on Mycobacterium abscessus." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/50056341875435815221.
Full textAbstract:
博士國立陽明大學
微生物及免疫學研究所
104
Mycobacterium abscessus has emerged as the most pathogenic and chemotherapy-resistant rapid-growing mycobacterium. The mechanism of antibiotic resistance in M. abscessus was well studied, but effect of antibiotics on virulence of M. abscessus was still unknown. In this study, we observed that colony morphology of M. abscessus was transiently altered in the presence of aminoglycoside antibiotics; meanwhile their virulence and biofilm formation was also enhanced. Amikacin pretreatment contributed to ability of anti-phagocytosis, TNF-α cytokine stimulation and persistence to human macrophage-mediated killing. In addition, aminoglycoside antibiotics promoted the drug tolerance in M. abscessus. Sub-MIC amikacin activated whiB7Mabs gene expression. Overexpression of WhiB7Mabs triggered the colony morphotype switch, and enhanced the persistence against macrophage-mediated killing. Globally, aminoglycoside antibiotics switched the avirulent smooth morphotype into invasive rough morphotype of M. abscessus through WhiB7-mediated pathway. Thus, these findings suggested that sub-MIC aminoglycoside treatment could predispose the M. abscessus infection patients to more severe illness and may concern the guideline of antibiotic therapy.