Journal articles on the topic 'Hyaloid vascular system'
To see the other types of publications on this topic, follow the link: Hyaloid vascular system.
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 27 journal articles for your research on the topic 'Hyaloid vascular system.'
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 journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Schaepdrijver, L., P. Simoens, H. Lauwers, J. P. Geest, and G. Charlier. "The hyaloid vascular system of the pig." Anatomy and Embryology 180, no. 6 (November 1989): 549–54. http://dx.doi.org/10.1007/bf00300552.
Full text
2
Yoshikawa, Yusuke, Toru Yamada, Ikue Tai-Nagara, Keisuke Okabe, Yuko Kitagawa, Masatsugu Ema, and Yoshiaki Kubota. "Developmental regression of hyaloid vasculature is triggered by neurons." Journal of Experimental Medicine 213, no. 7 (June 20, 2016): 1175–83. http://dx.doi.org/10.1084/jem.20151966.
Full textAbstract:
Vascular development involves not only vascular growth, but also regression of transient or unnecessary vessels. Hyaloid vasculature is the temporary circulatory system in fetal eyes, which spontaneously degenerates when the retinal blood vessels start to grow. Failure of the hyaloid vessels to regress leads to disease in humans, persistent hyperplastic primary vitreous, which causes severe intraocular hemorrhage and impairs visual function. However, the mechanism underlying the endogenous program that mediates spontaneous regression of the hyaloid vessels is not well understood. In this study, we identify a robust switch triggering this program directed by neurons in mice. Marked up-regulation of vascular endothelial growth factor (VEGF) receptor 2 (VEGFR2) occurs in retinal neurons just after birth via distal-multipotent-mesodermal enhancer, a hemangioblast-specific enhancer of VEGFR2. Genetic deletion of neuronal VEGFR2 interrupts this program, resulting in massive hyaloid vessels that persist even during late postnatal days. This abnormality is caused by excessive VEGF proteins in the vitreous cavity as a result of impairment in the neuronal sequestration of VEGF. Collectively, our data indicate that neurons trigger transition from the fetal to the postnatal circulatory systems in the retina.
3
Zhu, Meidong, Michele C. Madigan, Diana van Driel, Juliani Maslim, Francis A. Billson, Jan M. Provis, and Philip L. Penfold. "The Human Hyaloid System: Cell Death and Vascular Regression." Experimental Eye Research 70, no. 6 (June 2000): 767–76. http://dx.doi.org/10.1006/exer.2000.0844.
Full text
4
Kim, Tae-Hoon, Taeyoon Son, and Xincheng Yao. "Functional OCT angiography reveals early physiological dysfunction of hyaloid vasculature in developing mouse eye." Experimental Biology and Medicine 244, no. 10 (May 24, 2019): 819–23. http://dx.doi.org/10.1177/1535370219850787.
Full textAbstract:
Hyaloid vascular system (HVS) is a transient capillary network nourishing developing eye. Better study of the HVS regression correlated with eye development is essential for in-depth understanding of the nature of vision system. In this study, we demonstrate the feasibility of longitudinal optical coherence tomography (OCT) and OCT angiography (OCTA) monitoring of the HVS in C57BL/6J mice. OCT enables morphological monitoring of the HVS regression, and OCTA allows physiological assessment of the HVS involution correlated with eye development. Functional OCTA reveals early physiological dysfunction before morphological regression of the hyaloid vasculature in developing mouse eye. We anticipate that noninvasive, simultaneous OCT/OCTA observation of morphological regression and physiological degradation in normal and diseased animal models will be valuable to unravel the complex mechanisms of the HVS regression correlated with normal eye development and abnormal persistent hyaloid conditions. Impact statement Hyaloid vascular system (HVS) is known to have an essential role in the eye development. However, established knowledge of the HVS largely relies on end-point studies with biochemically fixed tissues, lacking a full description of the natural dynamics of the HVS correlated with eye development. An imaging methodology for noninvasive, longitudinal, and high-resolution monitoring of the HVS is important not only for better understanding of the nature of the vision system and is also valuable for better study of abnormal eye conditions. Here, we report the feasibility of in vivo optical coherence tomography (OCT) and OCT angiography (OCTA) imaging of the HVS regression in developing mouse eye. OCT enables morphological imaging of the HVS structure, and OCTA allows functional assessment of the HVS physiology correlated with eye development.
5
Albè, Elena, Jin-Hong Chang, Nathalie F. Azar, Alexander R. Ivanov, and Dimitri T. Azar. "Proteomic Analysis of the Hyaloid Vascular System Regression during Ocular Development." Journal of Proteome Research 7, no. 11 (November 7, 2008): 4904–13. http://dx.doi.org/10.1021/pr800551m.
Full text
6
Zhang, Hui, Julie Tse, Xuemei Hu, Marlys Witte, Michael Bernas, Jinjoo Kang, Firehiwott Tilahun, Young-Kwon Hong, Mengsheng Qiu, and Lu Chen. "Novel Discovery of LYVE-1 Expression in the Hyaloid Vascular System." Investigative Opthalmology & Visual Science 51, no. 12 (December 1, 2010): 6157. http://dx.doi.org/10.1167/iovs.10-5205.
Full text
7
FUJISAWA, HIROMI, NAOYUKI SERIU, BING-HUA ZHU, KEIICHI HIGUCHI, and MASANORI HOSOKAWA. "Inheritance and Strain Distribution of a Persistent Hyaloid Vascular System in Mice." Experimental Eye Research 64, no. 4 (April 1997): 553–58. http://dx.doi.org/10.1006/exer.1996.0238.
Full text
8
Hosokawa, Masanori, Yasushi Ashida, Takatoshi Matsushita, Kenshirou Takahashi, and Toshio Takeda. "Persistent Hyaloid Vascular System in Age-related Cataract in a SAM Strain of Mouse." Experimental Eye Research 57, no. 4 (October 1993): 427–34. http://dx.doi.org/10.1006/exer.1993.1144.
Full text
9
Kishimoto, Ayuko, Shunsuke Kimura, Junko Nio-Kobayashi, Hiromi Takahashi-Iwanaga, Ah-Mee Park, and Toshihiko Iwanaga. "Histochemical characteristics of regressing vessels in the hyaloid vascular system of neonatal mice: Novel implication for vascular atrophy." Experimental Eye Research 172 (July 2018): 1–9. http://dx.doi.org/10.1016/j.exer.2018.03.024.
Full text
10
Miodoński, Adam J., and Thomas Bär. "The superficial vascular hyaloid system in the eye of the frogs, Rana temporaria and Rana esculenta." Cell and Tissue Research 250, no. 2 (November 1987): 465–73. http://dx.doi.org/10.1007/bf00219093.
Full text
11
McLeod, D. Scott, Takuya Hasegawa, Takayuki Baba, Rhonda Grebe, Ines Galtier d'Auriac, Carol Merges, Malia Edwards, and Gerard A. Lutty. "From Blood Islands to Blood Vessels: Morphologic Observations and Expression of Key Molecules during Hyaloid Vascular System Development." Investigative Opthalmology & Visual Science 53, no. 13 (December 3, 2012): 7912. http://dx.doi.org/10.1167/iovs.12-10140.
Full text
12
Ashida, Yasushi, Toshio Takeda, and Masanori Hosokawa. "Protein Alterations in Age-related Cataract Associated with a Persistent Hyaloid Vascular System in Senescence-accelerated Mouse (SAM)." Experimental Eye Research 59, no. 4 (October 1994): 467–74. http://dx.doi.org/10.1006/exer.1994.1132.
Full text
13
Albè, Elena, Elizabeth Escalona, Rama Rajagopal, Joel A. Javier, Jin-Hong Chang, and Dimitri T. Azar. "Proteomic identification of activin receptor-like kinase-1 as a differentially expressed protein during hyaloid vascular system regression." FEBS Letters 579, no. 25 (September 28, 2005): 5481–86. http://dx.doi.org/10.1016/j.febslet.2005.08.078.
Full text
14
Segarra, Marta, Hidetaka Ohnuki, Dragan Maric, Ombretta Salvucci, Xu Hou, Anil Kumar, Xuri Li, and Giovanna Tosato. "Semaphorin 6A regulates angiogenesis by modulating VEGF signaling." Blood 120, no. 19 (November 8, 2012): 4104–15. http://dx.doi.org/10.1182/blood-2012-02-410076.
Full textAbstract:
Abstract Formation of new vessels during development and in the mature mammal generally proceeds through angiogenesis. Although a variety of molecules and signaling pathways are known to underlie endothelial cell sprouting and remodeling during angiogenesis, many aspects of this complex process remain unexplained. Here we show that the transmembrane semaphorin6A (Sema6A) is expressed in endothelial cells, and regulates endothelial cell survival and growth by modulating the expression and signaling of VEGFR2, which is known to maintain endothelial cell viability by autocrine VEGFR signaling. The silencing of Sema6A in primary endothelial cells promotes cell death that is not rescued by exogenous VEGF-A or FGF2, attributable to the loss of prosurvival signaling from endogenous VEGF. Analyses of mouse tissues demonstrate that Sema6A is expressed in angiogenic and remodeling vessels. Mice with null mutations of Sema6A exhibit significant defects in hyaloid vessels complexity associated with increased endothelial cell death, and in retinal vessels development that is abnormally reduced. Adult Sema6A-null mice exhibit reduced tumor, matrigel, and choroidal angiogenesis compared with controls. Sema6A plays important roles in development of the nervous system. Here we show that it also regulates vascular development and adult angiogenesis.
15
Roldugin, A. A., E. G. Maslennikova, M. A. Kovalevskaya, and E. A. Shpinova. "Conditioned autologous plasma (ACP) in the treatment of large macular holes." Modern technologies in ophtalmology, no. 1 (March 25, 2022): 122–27. http://dx.doi.org/10.25276/2312-4911-2022-1-122-127.
Full textAbstract:
Background. Macular tear (MR) is a disease that leads to a significant decrease in visual acuity, central scotoma and metamorphopsia, which significantly affects patients' quality of life. For several decades a lot of techniques of MR treatment have been implemented, but modern vitreoretinal surgery is still searching for treatment methods allowing to achieve maximal anatomic and functional results, so the study of application of autologous conditioned plasma (ACP) in MR treatment today is of particular interest. Purpose. Retrospective comparative analysis of surgical treatment of idiopathic MR using ACP. Material and methods. The research was carried out on the basis of Microsurgical ophthalmic center of high-technology medical care of Voronezh Regional Clinical Ophthalmologic Hospital. A total of 82 eyes with idiopathic MR were operated on. Two groups of patients were studied. The first group of patients (41 eyes) underwent surgical treatment: microinvasive three-port 25G-vitreoectomy with membranopilling removal of posterior hyaloid membrane to the extreme periphery and internal border membrane in the central retinal region within the vascular arcades with subsequent tamponade of vitreal cavity with air, intravitreal to macular zone in layers dosed with autologous conditioned plasma until the appearance of visual film. To obtain autologous conditioned plasma, 15 ml of a patient's venous blood was collected immediately before surgery in a patented dual-circuit Arthrex ACP syringe (Germany), which was then centrifuged for 5 minutes at a speed of 1500 rpm. Surgical treatment was performed on the Constellation Vision System using a Topcon Offiss OMS-800 microscope. The second group (41 eyes) underwent microinvasive three-port 25G-vitreoectomy with membranopilling removal of posterior hyaloid membrane to the extreme periphery and inner border membrane in the central retinal region within the vascular arcades followed by vitreal cavity tamponade with air. The results of treatment were assessed on the 7th day. All patients underwent full ophthalmological examination according to the existing standards, which included: visometry, perimetry, biomicroscopy, biomicrophthalmoscopy, B-scanning, optical coherence tomography of the macular area for morphometric evaluation of macular rupture on Optovue RTVue 100. Results. The results of the treatment were assessed on the 7th day. MR closure according to OCT data was observed in 97 % of cases in the first group, in the second group anatomical integrity of the macular area was restored in 90 % of cases. The MRR before and after surgery in the group with ACP was 0.149 ± 0.029 to 0.229 ± 0.025. The MCOZ before and after surgery in the control group was 0.161 ± 0.031 to 0.175 ± 0.027. According to the results of ACP D.G. Arsyutov, in 57 % of cases there was a complete blocking of MR in the early postoperative period, in the distant postoperative period a completely blocked rupture was found in 43 %. Conclusions. The results obtained confirm the effectiveness of ACP for the treatment of large idiopathic macular ruptures. The use of plasma in the treatment of MR allows to achieve high anatomical and functional results in the postoperative period. Keywords: macular rupture, autologous conditioned plasma
16
Roldugin, A. A., E. G. Maslennikova, M. A. Kovalevskaya, and E. A. Shpinova. "Conditioned autologous plasma (ACP) in the treatment of large macular holes." Modern technologies in ophtalmology, no. 1 (March 25, 2022): 122–27. http://dx.doi.org/10.25276/2312-4911-2022-1-122-127.
Full textAbstract:
Background. Macular tear (MR) is a disease that leads to a significant decrease in visual acuity, central scotoma and metamorphopsia, which significantly affects patients' quality of life. For several decades a lot of techniques of MR treatment have been implemented, but modern vitreoretinal surgery is still searching for treatment methods allowing to achieve maximal anatomic and functional results, so the study of application of autologous conditioned plasma (ACP) in MR treatment today is of particular interest. Purpose. Retrospective comparative analysis of surgical treatment of idiopathic MR using ACP. Material and methods. The research was carried out on the basis of Microsurgical ophthalmic center of high-technology medical care of Voronezh Regional Clinical Ophthalmologic Hospital. A total of 82 eyes with idiopathic MR were operated on. Two groups of patients were studied. The first group of patients (41 eyes) underwent surgical treatment: microinvasive three-port 25G-vitreoectomy with membranopilling removal of posterior hyaloid membrane to the extreme periphery and internal border membrane in the central retinal region within the vascular arcades with subsequent tamponade of vitreal cavity with air, intravitreal to macular zone in layers dosed with autologous conditioned plasma until the appearance of visual film. To obtain autologous conditioned plasma, 15 ml of a patient's venous blood was collected immediately before surgery in a patented dual-circuit Arthrex ACP syringe (Germany), which was then centrifuged for 5 minutes at a speed of 1500 rpm. Surgical treatment was performed on the Constellation Vision System using a Topcon Offiss OMS-800 microscope. The second group (41 eyes) underwent microinvasive three-port 25G-vitreoectomy with membranopilling removal of posterior hyaloid membrane to the extreme periphery and inner border membrane in the central retinal region within the vascular arcades followed by vitreal cavity tamponade with air. The results of treatment were assessed on the 7th day. All patients underwent full ophthalmological examination according to the existing standards, which included: visometry, perimetry, biomicroscopy, biomicrophthalmoscopy, B-scanning, optical coherence tomography of the macular area for morphometric evaluation of macular rupture on Optovue RTVue 100. Results. The results of the treatment were assessed on the 7th day. MR closure according to OCT data was observed in 97 % of cases in the first group, in the second group anatomical integrity of the macular area was restored in 90 % of cases. The MRR before and after surgery in the group with ACP was 0.149 ± 0.029 to 0.229 ± 0.025. The MCOZ before and after surgery in the control group was 0.161 ± 0.031 to 0.175 ± 0.027. According to the results of ACP D.G. Arsyutov, in 57 % of cases there was a complete blocking of MR in the early postoperative period, in the distant postoperative period a completely blocked rupture was found in 43 %. Conclusions. The results obtained confirm the effectiveness of ACP for the treatment of large idiopathic macular ruptures. The use of plasma in the treatment of MR allows to achieve high anatomical and functional results in the postoperative period. Keywords: macular rupture, autologous conditioned plasma
17
Roldugin, A. A., E. G. Maslennikova, M. A. Kovalevskaya, and E. A. Shpinova. "Conditioned autologous plasma (ACP) in the treatment of large macular holes." Modern technologies in ophtalmology, no. 1 (March 25, 2022): 122–27. http://dx.doi.org/10.25276/2312-4911-2022-1-122-127.
Full textAbstract:
Background. Macular tear (MR) is a disease that leads to a significant decrease in visual acuity, central scotoma and metamorphopsia, which significantly affects patients' quality of life. For several decades a lot of techniques of MR treatment have been implemented, but modern vitreoretinal surgery is still searching for treatment methods allowing to achieve maximal anatomic and functional results, so the study of application of autologous conditioned plasma (ACP) in MR treatment today is of particular interest. Purpose. Retrospective comparative analysis of surgical treatment of idiopathic MR using ACP. Material and methods. The research was carried out on the basis of Microsurgical ophthalmic center of high-technology medical care of Voronezh Regional Clinical Ophthalmologic Hospital. A total of 82 eyes with idiopathic MR were operated on. Two groups of patients were studied. The first group of patients (41 eyes) underwent surgical treatment: microinvasive three-port 25G-vitreoectomy with membranopilling removal of posterior hyaloid membrane to the extreme periphery and internal border membrane in the central retinal region within the vascular arcades with subsequent tamponade of vitreal cavity with air, intravitreal to macular zone in layers dosed with autologous conditioned plasma until the appearance of visual film. To obtain autologous conditioned plasma, 15 ml of a patient's venous blood was collected immediately before surgery in a patented dual-circuit Arthrex ACP syringe (Germany), which was then centrifuged for 5 minutes at a speed of 1500 rpm. Surgical treatment was performed on the Constellation Vision System using a Topcon Offiss OMS-800 microscope. The second group (41 eyes) underwent microinvasive three-port 25G-vitreoectomy with membranopilling removal of posterior hyaloid membrane to the extreme periphery and inner border membrane in the central retinal region within the vascular arcades followed by vitreal cavity tamponade with air. The results of treatment were assessed on the 7th day. All patients underwent full ophthalmological examination according to the existing standards, which included: visometry, perimetry, biomicroscopy, biomicrophthalmoscopy, B-scanning, optical coherence tomography of the macular area for morphometric evaluation of macular rupture on Optovue RTVue 100. Results. The results of the treatment were assessed on the 7th day. MR closure according to OCT data was observed in 97 % of cases in the first group, in the second group anatomical integrity of the macular area was restored in 90 % of cases. The MRR before and after surgery in the group with ACP was 0.149 ± 0.029 to 0.229 ± 0.025. The MCOZ before and after surgery in the control group was 0.161 ± 0.031 to 0.175 ± 0.027. According to the results of ACP D.G. Arsyutov, in 57 % of cases there was a complete blocking of MR in the early postoperative period, in the distant postoperative period a completely blocked rupture was found in 43 %. Conclusions. The results obtained confirm the effectiveness of ACP for the treatment of large idiopathic macular ruptures. The use of plasma in the treatment of MR allows to achieve high anatomical and functional results in the postoperative period. Keywords: macular rupture, autologous conditioned plasma
18
Promelle, Veronique, Sophie Bryselbout, and Solange Milazzo. "Visual prognosis of posterior and combined persistent fetal vasculature." European Journal of Ophthalmology 30, no. 2 (February 4, 2019): 284–88. http://dx.doi.org/10.1177/1120672119826478.
Full textAbstract:
Introduction: The persistent fetal vasculature refers to congenital anomalies of the globe resulting from the abnormal persistence of the hyaloid vascular system. It can present as anterior, posterior, or combined form. The aim of this study was to report the visual outcomes of posterior and combined forms of persistent fetal vasculature. Methods: This retrospective, single-center study included every patient referred to our outpatient clinic with a posterior or combined form of persistent fetal vasculature. The primary endpoint was the visual acuity of the impaired eye, or of the best eye if bilateral, at the end of follow-up. Results: In total, 18 eyes of 14 patients (10 males) were included. The combined form was the most prevalent (12 of 18 eyes), and 4 of 14 patients had bilateral impairment. The range of assessed visual acuity was from 20/2000 to 20/25. The best visual acuity in patients having undergone a surgical procedure was 20/63 (cataract extraction = 3, combined phacovitrectomy = 1). In patients who had been treated for amblyopia with patching, without surgery, the best visual acuity measured was 20/100 (5 patients). Among patients who had neither surgery nor patching therapy, there was one 63-year-old patient with a 20/25 visual acuity; the other ones had a low visual acuity of less than 20/200. All included eyes presented with nystagmus, amblyopia, and/or strabismus at the end of follow-up. Conclusion: The posterior and combined forms of persistent fetal vasculature are of poor visual prognosis. The severe or occulting presentations require surgery to obtain the same visual outcomes as the moderate forms treated for amblyopia with patching therapy.
19
Katargina, L. A., N. B. Chesnokova, O. V. Beznos, N. A. Osipova, and A. Yu Panova. "Angiotensin-II as a Trigger Factor in the Development of Retinopathy of Prematurity." Ophthalmology in Russia 17, no. 4 (December 27, 2020): 746–51. http://dx.doi.org/10.18008/1816-5095-2020-4-746-751.
Full textAbstract:
The multifactorial nature of the retinopathy of prematurity (ROP) pathogenesis, makes the thorough study of the mechanism of pathological retinal neovascularization actual. However recently the attention of scientists has been attracted by the participation of renin-angiotensin system (RAS) in the development of retinal vasoproliferative diseases. Purpose: to study the role of AT-II in the pathogenesis of experimental ROP (EROP) in the original model of the disease. Material and methods. To reproduce EROP Wistar rats (n = 15) were exposed to the oxygen concentration varying from 60 to 15% every 12 hours for 14 days from the first day after birth followed by room air for 7 days. Throughout the experiment, the room maintained a constant temperature (+26 °C) and light regime (12 hours a day, 12 hours a night) modes. Control rats (n = 12) were born and kept under normal oxygen content (21 %). Batches of EROP (n = 5) and control (n = 4) rats were sacrificed on 7, 14 and 21 days. All rats underwent binocular enucleation, after which every eyeball was opened on the limb, the cornea and lens were removed with the remains of a persistent vascular bag and a hyaloid artery. Retinas were isolated, homogenized and stored at -20 °C. Angiotensin-II (AT-II) in homogenates was measured using the IFA kit. Results. On the 7th day of the experiment, the level of AT-II in the retina of the experimental group rats was 0.19 ± 0.02 pg/mg protein that was significantly higher than in controls (0.12 ± 0.01 pg/mg protein). On the 14th and 21st days concentrations of AT-II in EROP and control groups had no significant difference. Conclusion. On the 7th day of the experiment, i.e. at the period corresponding to the existence of avascular retinal zones in both groups concentration of AT-II in the retinas of rats with EROP was significantly higher than in controls. This fact indicate the role of this proangiogenic factor in the induction of pathological neovascularization in ROP. Possible prognostic function of this parameter during the period before ROP manifestation has undoubted practical significance.
20
Houston, Isaac B., Meghana B. Kamath, Brock L. Schweitzer, Timothy M. Chlon, Jennifer K. Ondr, and Rodney P. DeKoter. "Hypomorphic Alleles of PU.1 Result in Impaired Myelopoiesis and Target Gene Expression." Blood 108, no. 11 (November 16, 2006): 1180. http://dx.doi.org/10.1182/blood.v108.11.1180.1180.
Full textAbstract:
Abstract PU.1 is an Ets-family transcription factor that is critical for normal hematopoiesis. Knock-out studies of PU.1 demonstrate that it is required for the development of myeloid and lymphoid cells. PU.1 is expressed at graded levels in the immune system, with higher expression in myeloid lineage cells. Previous research has suggested that differences in PU.1 concentration are involved in hematopoietic cell fate decisions. However, the mechanism by which target genes in developing cells sense and respond to different PU.1 concentrations is unknown. To address this question, we inserted a beta-lactamase reporter gene and a neomycin resistance cassette into the first coding exon of PU.1. Mice homozygous for the targeted allele (PU.1BN), and an allele in which neomycin was removed (PU.1BLAC), had graded reductions in PU.1 expression and function. PU.1BN/BN mice display a substantial reduction in fetal and neonatal myelopoiesis and are macrophage deficient, resulting in a failure of vascular regression in the developing eye. A fraction of these mice survive until weaning and have an accumulation of c-Kit-expressing immature myeloid cells in the spleen and bone marrow. In addition, these mice acquire a myelomonocytic infiltration in the retina and hyaloid vessels of the eye. Mice homozygous for the second allele (PU.1BLAC/BLAC) survive less than one week and have a severe reduction in PU.1 activity and a block to myeloid development. Fetal livers from both types of mice lack any discernable mature myeloid cells and demonstrate a graded reduction in colony forming ability. To determine if these two alleles have an effect on gene expression, we established IL-7-dependent pro-B cell lines or IL-3-dependent cell lines from these mice as well as from wild type or PU.1 null controls. We found that PU.1-dependent target genes in these cell lines are expressed in a graded manner. In particular, expression of the gene encoding the low-affinity IgG Fc receptor (FcγRIIb) is directly responsive to PU.1 activity. In summary, these results demonstrate the critical importance of an appropriate threshold of PU.1 activity for normal hematopoiesis. The hypomorphic PU.1 alleles provide an excellent model for determining the mechanism of graded PU.1 levels in hematopoiesis.
21
Kurihara, Toshihide, Peter D. Westenskow, Tim U. Krohne, Edith Aguilar, Randall S. Johnson, and Martin Friedlander. "Astrocyte pVHL and HIF-α isoforms are required for embryonic-to-adult vascular transition in the eye." Journal of Cell Biology 195, no. 4 (November 14, 2011): 689–701. http://dx.doi.org/10.1083/jcb.201107029.
Full textAbstract:
Successful transition from embryonic to adult circulation is critical for survival of mammalian organisms. This shift occurs in the central cardiovascular circulation and in the eye as oxygen tension increases. However, its regulation is not well understood. We have used combinatorial gene deletion and overexpression assays to assess the effect of astrocyte-targeted deletion of von Hippel–Lindau tumor suppressor (Vhl), hypoxia-inducible factor-αs (Hif-αs), and Vegf on the normal regression of the hyaloidal vessels, the fetal ocular circulation system. Astrocytic Vhl deletion induced accelerated hyaloidal regression and subsequent massive secondary outgrowth. Combinatorial gene deletion involving Vhl, Hif-αs, and Vegf genes revealed that HIF-2α/vascular endothelial growth factor signaling induces secondary outgrowth in Vhl mutants. Conversely, HIF-1α regulated macrophage migration inhibitory factor and promoted macrophage infiltration that accelerates hyaloidal vessel regression. The phenotype observed in Vhl mutants strongly resembles human persistent hyperplastic primary vitreous cases and may provide insights into vascular remodeling mechanisms in other systems.
22
Katargina, L. A., N. A. Osipova, A. J. Panova, N. S. Bondarenko, Yu O. Nikishina, A. R. Murtazina, and M. V. Ugryumov. "Studying the pathogenic role of catecholamines in the development of retinopathy of prematurity on an experimental model of the disease." Russian Ophthalmological Journal 12, no. 4 (December 12, 2019): 64–69. http://dx.doi.org/10.21516/2072-0076-2019-12-4-64-69.
Full textAbstract:
Purpose. To study the involvement of dopamine and noradrenaline in the pathogenesis of retinopathy of prematurity (ROP) on an original rat model of the disease.Material and methods. The study was conducted on 41 newborn Wistar rats (82 eyes), divided into 2 groups: experimental (EROP, rats with experimental ROP, n = 21) and control (n = 20). The rats were taken out of the experiment on the 7th, 14th, 23rd and 28th days of life. All rat pups were given binocular enucleation at the indicated times, whereupon the eyeballs were dissected along the limbus and the cornea, lens, hyaloid system, and vitreous were removed. The retina was isolated from the eye cup. The isolated retinal samples were homogenized in 10 volumes of 0.1 n HClO4 containing 50 pmol/ml (or more) of 3,4-dihydroxybenzylamine (DBA), using an ultrasonic homogenizer (Labsonic M, Sartorius), centrifuged at 2000g for 20 minutes, and the norepinephrine, dopamine and precursor of dopamine — L-3,4 dihydroxyphenylalanine (L-DOPA) were determined in the resulting supernatant. The contents of substances were measured using reverse phase high performance liquid chromatography with electrochemical detection (Amperometric detector LC-4B, Bioanalytical Systems, USA) set at the potential of 850 mV.Results. On the 7th day, on which avascular retinal zones in both groups of animals existed, no significant differences were found in the content of monoamines in the retina of rats with EROP and in the control group. On the 28th day, the content of noradrenaline, dopamine and L-DOPA in the retina of the experimental group was significantly increased compared with the control. On day 23, corresponding to the peak of neovascularization in the EROP model applied, the level of norepinephrine in the retina of experimental group rats was significantly higher, while the level of L-DOPA was significantly lower compared to the control group. The dopamine level was comparable in both study groups and similar to the level of L-DOPA in the control group. On the 28th day, corresponding to the beginning of EROP regression accompanied by vascular activity decrease, the content of dopamine and L-DOPA remained lower than in the control group.Conclusion. During the development of pathological neovascularization of rat pup retina with EROP, the level of noradrenaline is growing, revealing a peak corresponding to the period of pronounced pathological growth of retinal vessels within the applied model, which indicates to the fact of noradrenalin proangiogenic properties and its direct participation in the pathogenesis of ROP. The level of dopamine and its predecessor, L-DOPA, increased towards the 14th day as compared to its level detected on the 7th day, which may be due to the maturation of the amacrine cells producing, and then, on the day 23. i. e. during the period corresponding to the maximum peak of angiogenesis, its relative decrease of L-DOPA was noted. It can be assumed that the lack of this monoamine, and hence insufficient manifestation of its anti-angiogenic properties contributes to the development of uncontrolled neovascularization of the retina.
23
Özsaygili, Cemal, Sengul Ozdek, Mehmet Cuneyt Ozmen, Hatice Tuba Atalay, and Duygu Yalinbas Yeter. "Parameters affecting postoperative success of surgery for stage 4A/4B ROP." British Journal of Ophthalmology 103, no. 11 (January 18, 2019): 1624–32. http://dx.doi.org/10.1136/bjophthalmol-2018-312922.
Full textAbstract:
PurposeTo describe the long-term anatomical and functional results of surgery for retinal detachment (RD) associated with stage 4 retinopathy of prematurity (ROP) and patient and surgery-related factors affecting postoperative success.DesignRetrospective case series at a single tertiary referral paediatric vitreoretinal practice.MethodsOne hundred and twenty-one eyes of 82 infants (40 female/42 male) who underwent lens-sparing vitrectomy (LSV) or lensectomy with vitrectomy surgery for stage 4A and 4B ROP at Gazi University Department of Ophthalmology between 2011 and 2016 were enrolled in this study. Patient characteristics including gestational age, birth weight, gender, stage of ROP at presentation, preoperative treatment (laser, anti-vascular endothelial growth factor (VEGF) or combined), anatomical and functional outcome and complications were recorded. The effect of birth weight, gestational age, presence of plus disease, preoperative treatment status, surgically induced posterior hyaloid detachment, postoperative vitreous haemorrhage and iatrogenic retinal tear formation on anatomical and functional results was evaluated.Results61.2% of the eyes were stage 4A and 38.8% were stage 4B ROP. The mean follow-up was 24.5 months. 18.2% of the eyes had no preoperative treatment. Anatomical success was 86.5% for stage 4A and 68.1% for stage 4B at the first year, 91.7% for stage 4A and 69.4% for stage 4B at the second year, and 95.8% for stage 4A and 57.9% for stage 4B at the third year. Functional success was 85.1% for stage 4A and 65.9% for stage 4B at the first year, 89.6% for stage 4A and 61.1% for stage 4B at the second year, and 87.5% for stage 4A and 57.8% for stage 4B at the third year. The mean visual acuity was 1.12±0.34 logarithm of the minimum angle of resolution (logMAR) for stage 4A and 1.34±0.32 logMAR at the 3-year follow-up duration (p>0.05). There was preoperative plus disease in 59.5% of the eyes. Subsequent retinal surgeries were required in 17.4% of the eyes. Presence of plus disease and absence of preoperative treatment, iatrogenic retinal tear formation and postoperative vitreous haemorrhage were found to have significant negative effects, while surgical induction of posterior hyaloid detachment and sparing the lens intraoperatively affected the anatomical and functional results positively.ConclusionsSurgery for stage 4 ROP-associated RD resulted in encouraging anatomical and functional outcomes and the results are even better in eyes with preoperative (laser/anti-VEGF) treatment, LSV and surgically induced posterior hyaloid detachment.
24
Ba, Amadou Tidiane. "Structure et ultrastructure de l'haustorium du Striga hermonthica, une scrophulariacée parasite du mil (Pennisetum typhoides)." Canadian Journal of Botany 66, no. 11 (November 1, 1988): 2111–17. http://dx.doi.org/10.1139/b88-289.
Full textAbstract:
Striga hermonthica (Del.) Benth., (Scrophulariaceae) a parasite of pearl millet (Pennisetum typhoides (Burm.) Stapf and Hubb.), is attached to its host roots by suckers (also called haustoria). The anatomy and ultrastructure of the haustoria described in this study, including the cytology of such haustorial features as intrusive cells, intertracheidal parenchymatous cells, axial vascular core, hyalin tissue, and radial vascular system. Investigations with both electron and fluorescence microscopy did not disclose the presence of phloem. This lack is considered to be a common feature of the haustoria of parasitic Scrophulariaceae.
25
Mudhar, H. S., R. A. Pollock, C. Wang, C. D. Stiles, and W. D. Richardson. "PDGF and its receptors in the developing rodent retina and optic nerve." Development 118, no. 2 (June 1, 1993): 539–52. http://dx.doi.org/10.1242/dev.118.2.539.
Full textAbstract:
We have used in situ hybridization to visualize cells in the developing rat retina and optic nerve that express mRNAs encoding the A and B chains of platelet-derived growth factor (PDGF-A and PDGF-B), and the alpha and beta subunits of the PDGF receptor (PDGF-alpha R and PDGF-beta R). We have also visualized PDGF-A protein in these tissues by immunohistochemistry. In the retina, PDGF-A mRNA is present in pigment epithelial cells, ganglion neurons and a subset of amacrine neurons. PDGF-A transcripts accumulate in ganglion neurons during target innervation and in amacrine neurons around the time of eye opening, suggesting that PDGF-A expression in these cells may be regulated by target-derived signals or by electrical activity. In the mouse retina, PDGF-A immunoreactivity is present in the cell bodies, dendrites and proximal axons of ganglion neurons, and throughout the inner nuclear layer. PDGF-alpha R mRNA is expressed in the retina by astrocytes in the optic fibre layer and by a subset of cells in the inner nuclear layer that might be Muller glia or bipolar neurons. Taken together, our data suggest short-range paracrine interactions between PDGF-A and PDGF-alpha R, the ligand and its receptor being expressed in neighbouring layers of cells in the retina. In the optic nerve, PDGF-A immunoreactivity is present in astrocytes but apparently not in the retinal ganglion cell axons. PDGF-alpha R+ cells in the optic nerve first appear near the optic chiasm and subsequently spread to the retinal end of the nerve; these PDGF-alpha R+ cells are probably oligodendrocyte precursors (Pringle et al., 1992). RNA transcripts encoding PDGF-B and PDGF-beta R are expressed by cells of the hyaloid and mature vascular systems in the eye and optic nerve.
26
Schaff, Zsuzsa, Krisztina Danics, Adrián Pesti, Gábor Lotz, Tibor Várkonyi, Deján Dobi, István Vályi-Nagy, Klára Törő, Tibor Glasz, and András Kiss. "A COVID–19 patológiája." Scientia et Securitas 2, no. 1 (July 30, 2021): 94–99. http://dx.doi.org/10.1556/112.2021.00002.
Full textAbstract:
Összefoglaló. A SARS-CoV-2-pandémia óta a Semmelweis Egyetemen és egyéb intézményekben rendszeresen végeznek boncolásokat, melyek feltárták a COVID–19 jellegzetességeit. A legsúlyosabb kép a tüdőben mutatkozik, melynek légtelensége változó kiterjedésű, oka összetett, így tüdővizenyő, fehérjében gazdag izzadmány, az erek vérrög okozta elzáródása és gyulladás. A szív, a vese, az agy és a máj változó mértékben érintett, érrögösödés, elhalás, degeneratív elváltozások mutatkoznak. A SARS-CoV-2-vírus fehérjéi (tüske, nukleokapszid) és a vírus genetikai anyaga (RNS) kimutatható az egyes szervekben, leginkább a tüdőben. Klinikopatológiai elemzéssel megállapítható, hogy a halál a SARS-CoV-2-fertőzés mint közvetlen kórok következménye, vagy egyéb krónikus megbetegedés, melyet súlyosbított a SARS-CoV-2-fertőzés, vagy a halál a vírusfertőzéstől függetlenül következett be. Summary. Since the beginning of the Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) pandemic with substantial mortality, serial autopsies at the Semmelweis University Budapest Hungary and other institutions revealed the most characteristic pathological changes and cause of death of patients in Coronavirus Disease-19 (COVID-19). The virus primarily affects the respiratory system and the most severe alterations can be seen in the lungs. The most characteristic changes, however, are non-specific, as the atelectasis of various extents and severe congestion. The alveoli are filled with edema fluid, protein-rich alveolar exudates, often forming hyalin membranes. Diffuse alveolar damage (DAD) can be noted, which have exudative and fibroproliferative forms. The desquamated alveolar epithelial and inflammatory cells which fill the alveolar spaces further block the oxygen transportation, causing hypoxia and induces ventilation problems. Vascular thrombosis and emboli coming from thrombotic vessels from other organs, might involve the small and larger vessels are common findings in COVID-19 sometimes associated with vasculitis. Extended hemorrhages and giant cells are common findings too. Superimposed bacterial infection might cause purulent bronchopneumonia. Aspiration pneumonia, in which remnant of food and parts of filters etc might be present in the bronchi, causing acute bronchopneumonia, occurs specially in intubated patients. Other organs such as the heart, kidneys, the central nervous system and the liver are similarly, though less severely involved by thrombosis, necrotic and degenerative changes. Myocardial fibrosis is common, however usually associated with previous chronic diseases similarly to the findings in the kidneys. Liver steatosis is common, partly as the result of infection, however treatment and previous liver diseases could be in the background too. Smaller and larger cerebral bleedings, cerebral infarcts of various sizes are detected often. The protein components (spike and nucleocapside) of the SARS-CoV-2 could be demonstrated by immunohistochemical methods and the RNA genome of the SARS-CoV-2 by in situ hybridization in several organs, with highest amounts in the lungs. Clinicopathological analyses effectively determine whether the cause of death in SARS-CoV-2 infection had been the direct result of the infection, or any other previously known chronic disease, which had been superposed by the viral infection. However, in certain cases, the death might not be associated with the SARS-CoV-2 infection. The correct determination of the cause of death of the patients with COVID-19 is by consultation between clinicians and pathologists.
27
Kim, Tae-Hoon, Taeyoon Son, David Le, and Xincheng Yao. "Longitudinal OCT and OCTA monitoring reveals accelerated regression of hyaloid vessels in retinal degeneration 10 (rd10) mice." Scientific Reports 9, no. 1 (November 13, 2019). http://dx.doi.org/10.1038/s41598-019-53082-9.
Full textAbstract:
Abstract The hyaloid vascular system (HVS) is known to have an important role in eye development. However, physiological mechanisms of HVS regression and their correlation with developmental eye disorders remain unclear due to technical limitations of conventional ending point examination with fixed tissues. Here, we report comparative optical coherence tomography (OCT) and OCT angiography (OCTA) monitoring of HVS regression in wild-type and retinal degeneration 10 (rd10) mice. Longitudinal OCTA monitoring revealed accelerated regression of hyaloid vessels correlated with retinal degeneration in rd10. Quantitative OCT measurement disclosed significant distortions of both retinal thickness and the vitreous chamber in rd10 compared to WT mice. These OCT/OCTA observations confirmed the close relationship between HVS physiology and retinal neurovascular development. The distorted HVS regression might result from retinal hyperoxia or dopamine abnormality due to retinal remodeling in rd10 retina. By providing a noninvasive imaging platform for longitudinal monitoring of HVS regression, further OCT/OCTA study may lead to in-depth understanding of the physiological mechanisms of HVS regression in normal and diseased eyes, which is not only important for advanced study of the nature of the visual system but also may provide insights into the development of better treatment protocols of congenital eye disorders.