Artículos de revistas: "Beta autoradiography"

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Takekawa, Shoichi, Yoshihiko Ueda, Yoshihiko Ueda, Yoshihiro Hiramatsu, Hirotsugu Munechika y Fumio Shishido. "Imaging of Beta-Rays from Tissue Blocks with Thorotrast Deposition by Autoradiography using Fuji Computed Radiography". Jurnal Radiologi Indonesia 1, n.º 2 (1 de septiembre de 2015): 58–64. http://dx.doi.org/10.33748/jradidn.v1i2.7.

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Background: Autoradiography of tissue with radioactive substance such as Thorotrast by Fuji Computed Radiography (FCR) has been available. We obtained autoradiographs from Thorotrast-deposited tissue by FCR. However, the nature of radiation from tissue with Thorotrast was not certain, because alpha particles are shielded by the plastic front of the FCR cassette. Therefore, we undertook investigation to clearly explain the nature of radiation from Thorotrast in case of autoradiography.Materials and Methods: Tissue blocks of liver and spleen with Thorotrast deposition were imaged by autoradiography using FCR, and radioactivity of tissue blocks was measured by a GM survey meter. Measurement was carried out by both with and without an aluminum plate between the tissue and the surface of GM survey meter to shield beta-rays.Results: Autoradiographs of the liver and spleen with Thorotrast were successful. It took only one day to obtain autoradiograph of the spleen, and 14 days for the liver. The radioactivity count decreased dramatically when an aluminum plate was inserted between the specimen and GM survey meter, but some radiation remained. The tissue blocks were contained in a plastic bag and the front of the Cassette of Imaging Plate is covered by a thin plastic board, so alpha-rays from Thorium dioxide in Thorotrast had been shielded from the beginning.Conclusion: We concluded that the radiation from the tissue blocks with Thorotrast in a plastic bag was mostly from beta-rays and less than 5% of radiation was from gamma-rays from the daughter nuclei of Thorium dioxide.

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2

Eakin, T. J., D. G. Baskin, J. F. Breininger y W. L. Stahl. "Calibration of 14C-plastic standards for quantitative autoradiography with 33P." Journal of Histochemistry & Cytochemistry 42, n.º 9 (septiembre de 1994): 1295–98. http://dx.doi.org/10.1177/42.9.8064137.

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Probes labeled with 33P have potential for widespread use in in situ hybridization because they are better able to detect relatively scarce mRNAs compared with probes labeled with 35S, but the relatively short half-life of 33P is a disadvantage when it is used as a radioactivity standard for quantitative autoradiography. To determine if plastic sections containing 14C can be used as standards for quantitative autoradiography with 33P, we co-exposed 33P-labeled liver paste sections and 14C-plastic standards to Hyperfilm beta max. The autoradiographic response of Hyperfilm beta max to these isotopes was almost identical. Second-order polynomial equations obtained from analysis of film relative optical density and radioactivity permitted derivation of tissue-equivalent radioactivity from the film optical densities produced by the 14C standards for 1-14-day exposures. These results validate the use of plastic 14C standards for quantifying 33P used in contact film autoradiography.

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3

Birnkrant, D. J., P. B. Davis y P. Ernsberger. "Visualization of high- and low-affinity beta-adrenergic receptors in rat lung: upregulation by chronic hypoxia". American Journal of Physiology-Lung Cellular and Molecular Physiology 265, n.º 4 (1 de octubre de 1993): L389—L394. http://dx.doi.org/10.1152/ajplung.1993.265.4.l389.

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Chronic hypoxia induces a hyperadrenergic state which down-regulates beta-adrenergic receptors (beta-AR) in the heart. We visualized lung beta-AR binding sites after adaptation to chronic hypoxia by autoradiography of whole lung sections labeled with 50 pM 125I-labeled pindolol. A low concentration of agonist (32 nM isoproterenol) selectively masked beta-ARs with high affinity for agonists. Total specific beta-AR binding increased twofold with hypoxia. In both the control and hypoxic lung sections, 60–70% of the beta-ARs were in a high-affinity state, which could be reversed by guanine nucleotide. Autoradiography revealed a high density of high- and low-affinity beta-AR sites in lung parenchyma, predominantly involving alveolar walls, but also the walls of airways and blood vessels. The distribution of high- and low-affinity beta-AR within the lung was qualitatively identical. Hypoxia increased beta-AR binding without affecting its distribution. The majority of the additional beta-ARs induced during adaptation to chronic hypoxia are in the high-affinity state, and are thus of probable functional significance.

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4

Lees, J. E., J. F. Pearson, G. W. Fraser, J. M. Hales y P. G. Richards. "An MCP-based system for beta autoradiography". IEEE Transactions on Nuclear Science 46, n.º 3 (junio de 1999): 636–38. http://dx.doi.org/10.1109/23.775591.

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5

Sanghera, B., D. M. Raymond, G. Hall y R. J. Ott. "Digital beta autoradiography using silicon microstrip detectors". Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 310, n.º 1-2 (diciembre de 1991): 455–59. http://dx.doi.org/10.1016/0168-9002(91)91079-b.

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6

Lees, J. E. y G. W. Fraser. "Efficiency enhancements for MCP-based beta autoradiography imaging". Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 477, n.º 1-3 (enero de 2002): 239–43. http://dx.doi.org/10.1016/s0168-9002(01)01838-1.

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7

Lees, J. E., G. W. Fraser y D. Dinsdale. "Direct beta autoradiography using microchannel plate (MCP) detectors". Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 392, n.º 1-3 (junio de 1997): 349–53. http://dx.doi.org/10.1016/s0168-9002(97)00219-2.

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8

Woodhead, C. J. y A. J. Nimmo. "Beta adrenoceptors in human nasal mucosa". Journal of Laryngology & Otology 105, n.º 8 (agosto de 1991): 632–34. http://dx.doi.org/10.1017/s0022215100116871.

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AbstractThe significance of the beta adrenergic system in the nasal mucosa isunclear. The authors have used the technique of autoradiography to localize and classify beta adrenoceptors in human nasal mucosa. The receptors have been found to beexclusively of thebeta-2 subtype and the highest density is found in the glandularducts. It is suggested that the beta-adrenergic system may have a physiologically important role in controlling the electrolyte composition of nasal secretions.

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9

Wide, M., H. Persson, S. Gunnarsson, L. Wide y L. Seifi. "High frequency of in situ hybridization on thin plastic sections of human placenta with a cDNA probe for beta hCG." Journal of Histochemistry & Cytochemistry 37, n.º 8 (agosto de 1989): 1193–96. http://dx.doi.org/10.1177/37.8.2474022.

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We describe two different techniques with plastic embedding in in situ hybridization histochemistry (ISHH). Their applicability was demonstrated by use of human placenta of the tenth gestational week and a tritium-labeled cDNA probe for the beta-subunit of hCG. In the first method, ISHH was performed on whole pieces of tissue (en bloc ISHH) pretreated with a weak acid solution, embedded in methacrylate, and sectioned at 3 microns for autoradiography. In the second technique, en bloc ISHH was carried out on tissue pre-treated with the weak acid and thereafter with detergent to further facilitate probe penetration. An acrylic resin was used for embedding, and section thickness was reduced to 1 microns. With both techniques, beta hCG cDNA/mRNA hybrids were localized exclusively to the syncytiotrophoblast (ST), in agreement with a previous study using sections of frozen placentas for hybridization to the same probe. However, owing to the higher resolution of the plastic sections the reliability of this localization was greatly increased. The number of autoradiographic grains over the acrylic resin 1-microns sections was found to be considerably higher than that over the methacrylate 3-microns sections. This study showed that treatment of tissue with detergent before en bloc ISHH, with subsequent embedding in acrylic resin and sectioning at 1 microns, gives high resolution in combination with a high signal-to-noise ratio after autoradiography. As the acrylic resin permits cutting of ultrathin sections, the results suggest that the technique may become useful for ISHH studies at the subcellular level.

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10

Zhao, M., H. K. Hagler y K. H. Muntz. "Regulation of alpha 1-, beta 1-, and beta 2-adrenergic receptors in rat heart by norepinephrine". American Journal of Physiology-Heart and Circulatory Physiology 271, n.º 5 (1 de noviembre de 1996): H1762—H1768. http://dx.doi.org/10.1152/ajpheart.1996.271.5.h1762.

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Previous studies suggest that the desensitization and downregulation of beta 1-adrenergic receptors (beta 1-AR) in the failing heart are the result of the elevated plasma catecholamine levels associated with this disease. To examine norepinephrine (NE)-induced regulation of cardiac adrenergic receptors, rats were infused with l-NE (200 micrograms.kg-1.h-1 for 7 days) or vehicle (0.001 N HCl) by implantation of osmotic minipumps. The technique of coverslip autoradiography was used to quantify alpha 1-adrenergic receptors (alpha 1-AR), beta 1-AR, and beta 2-AR in different tissue compartments of rat hearts. For measurement of beta-AR binding, sections were incubated with 70 pM [125I]iodocyanopindolol (ICYP) alone or in the presence of 5 microM dl-propranolol or 5 x 10(-7) M CGP-20712A (a beta 1-antagonist) and then set up for autoradiography. [3H]prazosin (1 nM) with or without phentolamine was used to study alpha-AR binding. Chronic infusion of NE induced a greater downregulation of beta 2-AR compared with beta 1-AR in all regions studied, including atrial and ventricular myocytes, coronary arterioles, and connective tissue. An 18% loss of beta 1-AR was seen only in atrial myocytes; beta 1-AR density actually increased 28% in ventricular myocytes following NE infusion. There was a 15% decrease in alpha 1-AR in ventricular myocytes, whereas no change in alpha 1-AR density was seen in myocardial arterioles. Our study demonstrates that beta 2-AR are more susceptible to NE-induced downregulation than beta 1-AR. Thus other mechanisms may be involved in the selective downregulation of beta 1-AR in certain forms of heart failure.

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11

Verdurand, Mathieu, Elise Levigoureux, Sophie Lancelot, Waël Zeinyeh, Thierry Billard, Isabelle Quadrio, Armand Perret-Liaudet, Luc Zimmer y Fabien Chauveau. "Amyloid-Beta Radiotracer [18F]BF-227 Does Not Bind to Cytoplasmic Glial Inclusions of Postmortem Multiple System Atrophy Brain Tissue". Contrast Media & Molecular Imaging 2018 (2018): 1–7. http://dx.doi.org/10.1155/2018/9165458.

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The accumulation of aggregated alpha-synuclein (α-syn) in multiple brain regions is a neuropathological hallmark of synucleinopathies. Multiple system atrophy (MSA) is a synucleinopathy characterized by the predominant cerebral accumulation of aggregated α-syn as cytoplasmic glial inclusions (CGI). A premortem diagnosis tool would improve early diagnosis and help monitoring disease progression and therapeutic efficacy. One Positron Emission Tomography (PET) study suggested [11C]BF-227 as a promising radiotracer for monitoring intracellular α-syn deposition in MSA patients. We sought to confirm the binding of this radiotracer to α-syn using state-of-the-art autoradiography. Medulla sections were obtained from 9 MSA patients and 9 controls (London Neurodegenerative Diseases Brain Bank). [18F]BF-227, chemically identical to [11C]BF-227, was used at nanomolar concentrations to perform in vitro autoradiography assays. Autoradiograms were superimposed on fluorescent staining from the conformational anti-α-syn antibody 5G4 and quantified after immunofluorescence-driven definition of regions of interest. Autoradiography showed no specific signals in MSA patients in comparison to controls despite widespread pathology detected by immunofluorescence. Autoradiography does not support a significant binding of [18F]BF-227 to CGI at concentrations typically achieved in PET experiments.

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12

Voutilainen, Mikko, Juuso Sammaljärvi, Eveliina Muuri, Jérôme Donnard, Samuel Duval y Marja Siitari-Kauppi. "Digital autoradiography on C-14-labelled PMMA impregnated rock samples using the BeaverTM". MRS Advances 3, n.º 21 (2018): 1161–66. http://dx.doi.org/10.1557/adv.2018.226.

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In Finland and Sweden the KBS-3 concept has been chosen for the disposal of spent nuclear fuel in crystalline rock. Recent experiments have shown that heterogeneity of rock may play a major role in the transport of radionuclides. Autoradiographic methods have been proven to be able to assist the characterization of heterogeneous structures. In this study we tested a novel filmless autoradiographic device called BeaverTM which applies a micro patterned gaseous detector in order to quantitatively map beta emissions from C-14 atoms. The studied samples were impregnated with C-14-labelled methylmethacrylate (C-14-MMA) and polymerized to C-14-PMMA with thermal initiator. The BeaverTM was then used to determine the spatial distribution of the C-14-PMMA by measuring the C-14 emissions. The porosity is determined from the amount of C-14-PMMA in the rock sample and results were compared to ones from phosphor imaging plate autoradiography. The resulting images show a heterogeneous distribution of porosity which arises from the different minerals. The samples were chosen from three sites that have been used recently for in situ diffusion experiments: Olkiluoto (Finland), Äspö (Sweden) and Grimsel (Switzerland).

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13

Healy, D. P., P. A. Münzel y P. A. Insel. "Localization of beta 1- and beta 2-adrenergic receptors in rat kidney by autoradiography." Circulation Research 57, n.º 2 (agosto de 1985): 278–84. http://dx.doi.org/10.1161/01.res.57.2.278.

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14

Tolszczuk, M. y G. Pelletier. "Autoradiographic localization of beta-adrenoreceptors in rat uterus." Journal of Histochemistry & Cytochemistry 36, n.º 12 (diciembre de 1988): 1475–79. http://dx.doi.org/10.1177/36.12.2848069.

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The inhibitory effects of catecholamines on uterine smooth muscle are known to be mediated through beta-adrenergic receptors. To investigate further the distribution of these receptors in the rat uterus, we utilized in vitro autoradiography using [125I]-cyanopindolol [CYP], a specific beta-receptor ligand that has equal activity for both beta 1- and beta 2-receptor subtypes. The specificity of the labeling and the characterization of receptor subtypes in different cell types were achieved by displacement of radioligand with increasing concentrations of zinterol, a beta-adrenergic agonist with preferential affinity for the beta 2-adrenoreceptor subtype, and practolol, a beta-adrenergic antagonist that binds preferentially to the beta 1-subtype. Quantitative estimation of ligand binding was performed by densitometry. It was shown that the vast majority of beta-adrenoreceptors were of the beta 2-subtype and were found in high concentration not only in the myometrium but also in the endometrial and serosal epithelia. Specific labeling was also observed in glandular elements. These results suggest that beta-adrenoreceptors might be involved in different functions in the uterus.

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15

Pinto, J. E., A. J. Nazarali, T. Torda y J. M. Saavedra. "Autoradiographic characterization of beta-adrenoceptors in rat heart valve leaflets". American Journal of Physiology-Heart and Circulatory Physiology 256, n.º 3 (1 de marzo de 1989): H821—H827. http://dx.doi.org/10.1152/ajpheart.1989.256.3.h821.

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beta-Adrenoceptors were localized and characterized in valve leaflets of the rat heart. Sixteen micrometer-thick tissue sections containing the mitral and aortic valves were incubated with (-)3-[125I]iodocyanopindolol followed by autoradiography with computerized microdensitometry and comparison with 125I-labeled standards. beta-Adrenoceptors were present in all the valves studied. The selective beta 1-adrenoceptor antagonist CGP 20712 A (100 nM) displaced not more than 20% of the total binding sites, suggesting that most of the beta-adrenoceptors in the valve leaflets are of the beta 2-subtype. Forskolin-binding sites were detected in the mitral valve leaflet by incubation of adjacent tissue sections with [12-3H]forskolin. Our results indicate that catecholamines could regulate the function of the heart valves through stimulation of beta 2-adrenoceptors.

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16

Stoppacciaro, A., P. Bossu, P. Ghiara, L. P. Ruco, S. Censini, G. Scapigliati, S. Nuti, A. Tagliabue, C. D. Baroni y D. Boraschi. "Binding of IL-1 beta to IL-1R type II at single cell level." Journal of Immunology 147, n.º 5 (1 de septiembre de 1991): 1561–66. http://dx.doi.org/10.4049/jimmunol.147.5.1561.

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Abstract To gain information on the possible biologic role of IL-1R type II (IL-1RII), expression of the 68-kDa IL-1 binding protein on human lymphoblastoid B cells was investigated at single cell level. Binding of iodinated IL-1 beta was evaluated by autoradiography on cytosmears of IL-1RII positive B cell lines RAJI, the RAJI clone 1H7, and STS 25. Results obtained suggest an heterogeneity of IL-1RII expression within the B cell population, with only 5 to 16% of the cells able to bind IL-1 beta. Up-regulation of IL-1RII expression by dexamethasone, evident in conventional binding assays, was achieved through both increase in the number of IL-1 binding cells (14-30%) and augmentation of receptor density on positive cells, By combining autoradiography with immunocytochemical staining, it could be shown that about 80% of IL-1RII + cells were negative for Ki67, a nuclear antigen expressed from late G1 to M phase. Cell cycle dependent expression of IL-1RII was confirmed on cells enriched in different phases of the cell cycle by counterflow centrifugal elutriation. It is thus proposed that IL-1RII is associated to the cell cycle.

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17

Haddad, A., B. Kopriwa y G. Pelletier. "Localization of glycoproteins in insulin secretory granules by ultrastructural autoradiography." Journal of Histochemistry & Cytochemistry 35, n.º 10 (octubre de 1987): 1059–62. http://dx.doi.org/10.1177/35.10.3305700.

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To determine whether or not the secretory granules of insulin-secreting cells contained glycoproteins, isolated rat pancreatic islets were incubated for 2 and 4 hr in a medium containing L-[3H]-fucose. Quantitative analysis of high-resolution electron microscopic autoradiographs of the insulin-secreting beta cells demonstrated that glycoproteins with fucose residues are contained within the insulin secretory granule.

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18

Saito, K., M. Kurihara, R. Cruciani, W. Z. Potter y J. M. Saavedra. "Characterization of beta 1- and beta 2-adrenoceptor subtypes in the rat atrioventricular node by quantitative autoradiography." Circulation Research 62, n.º 1 (enero de 1988): 173–77. http://dx.doi.org/10.1161/01.res.62.1.173.

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19

IIDA, Takao, Yukimasa IKEBE y Osamu MATSUOKA. "Autoradiography of .ALPHA.-and .BETA.-emitters using a charged-particle imaging system." RADIOISOTOPES 36, n.º 7 (1987): 317–24. http://dx.doi.org/10.3769/radioisotopes.36.7_317.

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20

Leskinen, Anumaija, Pascal Fichet, Marja Siitari-Kauppi y Florence Goutelard. "Digital autoradiography (DA) in quantification of trace level beta emitters on concrete". Journal of Radioanalytical and Nuclear Chemistry 298, n.º 1 (16 de mayo de 2013): 153–61. http://dx.doi.org/10.1007/s10967-013-2535-6.

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21

Wells, K., R. J. Ott y J. H. MacDonald. "6. A novel CCD-based digital autoradiography system for quantitative beta imaging". Nuclear Medicine Communications 22, n.º 4 (abril de 2001): 436. http://dx.doi.org/10.1097/00006231-200104000-00018.

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22

Ohira, Y., W. Yasui, F. Kariya, T. Tanaka, I. Kitajima, I. Maruyama, S. Nagaoka, C. Sekiguchi y W. E. Hinds. "Spaceflight effects on beta-adrenoceptor and metabolic properties in rat plantaris". Journal of Applied Physiology 81, n.º 1 (1 de julio de 1996): 152–55. http://dx.doi.org/10.1152/jappl.1996.81.1.152.

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Effects of 14 days of spaceflight on beta-adrenoceptor (beta-AR), mitochondrial enzyme activities, and fiber type composition were studied in plantaris muscles of male adult Sprague-Dawley rats. The beta-AR was analyzed in cross sections by quantitative autoradiography. The maximum binding capacity (Bmax) of beta-AR was significantly lowered (approximately 29%) after flight, but the recovery was not completed within 9 days in 1-G environment. Because the dissociation constant remained unchanged, it is suggested that the changes in the Bmax were caused by the alteration of receptor number. The activities of succinate dehydrogenase (SDH) measured in whole homogenates were subnormal (approximately -24%) in muscles sampled approximately 5 h after flight but they were normalized during 9 days of recovery. The percent composition of fiber types and beta-hydroxyacyl CoA dehydrogenase (HAD) activity did not change significantly due to spaceflight. It is suggested that the spaceflight-induced decrease of the Bmax of beta-AR in plantaris was accompanied by a lowered activity of a mitochondrial inner-membrane enzyme SDH but not a matrix enzyme HAD.

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23

Greipp, PR, JA Katzmann, WM O'Fallon y RA Kyle. "Value of beta 2-microglobulin level and plasma cell labeling indices as prognostic factors in patients with newly diagnosed myeloma". Blood 72, n.º 1 (1 de julio de 1988): 219–23. http://dx.doi.org/10.1182/blood.v72.1.219.219.

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Abstract Beta 2-microglobulin (beta 2M) has been proposed as a prognostic factor in multiple myeloma (MM), but beta 2M levels are reported to correlate with other prognostic indicators such as stage and creatinine level. This study addressed the independent prognostic values of these and other variables, including plasma cell labeling indices (LI), in patients with newly diagnosed MM. beta 2M levels were measured with an enzyme-linked immunosorbent assay. LI were determined with a [3H]thymidine autoradiography method. By multivariate analysis and Kaplan-Meier survival analysis, the uncorrected beta 2M level remained the most significant prognostic factor after adjustment for age. Stage and creatinine level were closely related to beta 2M level and were no longer predictive of outcome after adjustment for age and beta 2M. Plasma cell LI varied independently of beta 2M level and remained predictive. A subset of patients with plasma-blastic myeloma had poor survival since beta 2M level and plasma cell LI were high. By using beta 2M level and LI, three risk groups were defined: low (beta 2M less than 4 micrograms/mL and LI less than 0.4%, median survival 48 months); intermediate (beta 2M less than 4 micrograms/mL and LI greater than or equal to 0.4%, median survival 29 months); and high (beta 2M greater than or equal to 4 micrograms/mL, median survival 12 months). Such grouping may better identify MM patients who might benefit from new treatment regimens.

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Greipp, PR, JA Katzmann, WM O'Fallon y RA Kyle. "Value of beta 2-microglobulin level and plasma cell labeling indices as prognostic factors in patients with newly diagnosed myeloma". Blood 72, n.º 1 (1 de julio de 1988): 219–23. http://dx.doi.org/10.1182/blood.v72.1.219.bloodjournal721219.

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Beta 2-microglobulin (beta 2M) has been proposed as a prognostic factor in multiple myeloma (MM), but beta 2M levels are reported to correlate with other prognostic indicators such as stage and creatinine level. This study addressed the independent prognostic values of these and other variables, including plasma cell labeling indices (LI), in patients with newly diagnosed MM. beta 2M levels were measured with an enzyme-linked immunosorbent assay. LI were determined with a [3H]thymidine autoradiography method. By multivariate analysis and Kaplan-Meier survival analysis, the uncorrected beta 2M level remained the most significant prognostic factor after adjustment for age. Stage and creatinine level were closely related to beta 2M level and were no longer predictive of outcome after adjustment for age and beta 2M. Plasma cell LI varied independently of beta 2M level and remained predictive. A subset of patients with plasma-blastic myeloma had poor survival since beta 2M level and plasma cell LI were high. By using beta 2M level and LI, three risk groups were defined: low (beta 2M less than 4 micrograms/mL and LI less than 0.4%, median survival 48 months); intermediate (beta 2M less than 4 micrograms/mL and LI greater than or equal to 0.4%, median survival 29 months); and high (beta 2M greater than or equal to 4 micrograms/mL, median survival 12 months). Such grouping may better identify MM patients who might benefit from new treatment regimens.

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25

Ghinea, N., A. Fixman, D. Alexandru, D. Popov, M. Hasu, L. Ghitescu, M. Eskenasy, M. Simionescu y N. Simionescu. "Identification of albumin-binding proteins in capillary endothelial cells." Journal of Cell Biology 107, n.º 1 (1 de julio de 1988): 231–39. http://dx.doi.org/10.1083/jcb.107.1.231.

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Isolated fat tissue microvessels and lung, whose capillary endothelia express in situ specific binding sites for albumin, were homogenized and subjected to SDS-gel electrophoresis and electroblotting. The nitrocellulose strips were incubated with either albumin-gold (Alb-Au) and directly visualized, or with [125I]albumin (monomeric or polymeric) and autoradiographed. The extracts of both microvascular endothelium and the lung express albumin-binding proteins (ABPs) represented by two pairs of polypeptides with major components of molecular mass 31 and 18 kD. The ABP peptides have pIs 8.05 to 8.75. Rabbit aortic endothelium, used as control, does not express detectable amounts of ABPs. The ABPs subjected to electrophoresis bind specifically and with high affinity (Kd = approximately 60 X 10(-9)M) both monomeric and polymeric albumin: the binding is saturable at approximately 80 nM concentration and 50% inhibition is reached at 5.5 micrograms/ml albumin concentration. Sulfhydryl-reducing agents beta-mercaptoethanol and dithiothreitol do not markedly affect the ABPs electrophoretic mobility and binding properties. As indicated by cell surface iodination of isolated capillary endothelium followed by electroblotting, autoradiography, and incubation with Alb-Au, the bands specifically stained by this ligand are also labeled with radioiodine.

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26

Teng, Yu, Hong Yang y Yulin Tian. "The Development and Application of Tritium-Labeled Compounds in Biomedical Research". Molecules 29, n.º 17 (29 de agosto de 2024): 4109. http://dx.doi.org/10.3390/molecules29174109.

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With low background radiation, tritiate compounds exclusively emit intense beta particles without structural changes. This makes them a useful tool in the drug discovery arsenal. Thanks to the recent rapid progress in tritium chemistry, the preparation and analysis of tritium-labeled compounds are now much easier, simpler, and cheaper. Pharmacokinetics, autoradiography, and protein binding studies have been much more efficient with the employment of tritium-labeled compounds. This review provides a comprehensive overview of tritium-labeled compounds regarding their properties, synthesis strategies, and applications.

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27

Park, Hae-Young, Kyeong-Han Park, Yong-Sik Kim, Sang-Goo Shin, Myung-Hee Chung y Chan-Woong Park. "Quantitative Autoradiography of Beta-1 and Beta-2 Adrenergic Receptor and Cellular Localization of mRNA for Beta-1 Adrenergic Receptor in Rat Brain". Molecules and Cells 6, n.º 4 (agosto de 1996): 456–62. http://dx.doi.org/10.1016/s1016-8478(23)07275-8.

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28

Miller, Brian W. "Radiation Imagers for Quantitative, Single-particle Digital Autoradiography of Alpha- and Beta-particle Emitters". Seminars in Nuclear Medicine 48, n.º 4 (julio de 2018): 367–76. http://dx.doi.org/10.1053/j.semnuclmed.2018.02.008.

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29

Yorke, E. D., L. E. Williams, A. J. Demidecki, D. B. Heidorn, P. L. Roberson y B. W. Wessels. "Multicellular dosimetry for beta-emitting radionuclides: Autoradiography, thermoluminescent dosimetry and three-dimensional dose calculations". Medical Physics 20, n.º 2 (marzo de 1993): 543–50. http://dx.doi.org/10.1118/1.597050.

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30

Kusumoto, F. M., K. G. Lurie, J. Dutton, H. Capili y J. B. Schwartz. "Effects of aging on AV nodal and ventricular beta-adrenergic receptors in the Fischer 344 rat". American Journal of Physiology-Heart and Circulatory Physiology 266, n.º 4 (1 de abril de 1994): H1408—H1415. http://dx.doi.org/10.1152/ajpheart.1994.266.4.h1408.

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The effects of aging on atrioventricular (AV) nodal and right and left ventricular beta-adrenergic receptor (beta-AR) characteristics were studied in Fischer 344 rat hearts using quantitative autoradiography. Twenty-micrometer-thick cardiac sections containing the compact AV node from 16 mature (4-6 mo old) rats, 6 middle-aged (12 mo old) rats, and 16 old (24 mo old) rats were incubated with [125I]iodocyanopindolol, [125I]iodocyanopindolol plus atenolol, or ICI 118551. Saturation experiments revealed a significant age-related decrease in AV nodal beta-AR density (mature: 190 +/- 46, middle-aged: 165 +/- 27, old: 133 +/- 34 amol/mm2; P < 0.01), with no change in affinity (mature: 106 +/- 62, middle-aged: 132 +/- 46, old: 128 +/- 66 pM). No age-related changes in AV nodal beta-AR subtype ratio (55% beta 1, 45% beta 2) or estimated compact AV node volume were detected (mature: 66 +/- 17, old: 65 +/- 23 microns 3). No difference in beta-AR density or affinity was detected between mature and old rats in either left (LV) or right (RV) ventricular tissue (LV, mature: 60 +/- 11, middle-aged: 59 +/- 11, old: 62 +/- 11 amol/mm2; RV, mature: 65 +/- 9, middle-aged: 65 +/- 11, old: 58 +/- 10 amol/mm2). beta-AR subtype ratios for the left ventricle (64% beta 1, 36% beta 2) and right ventricle (63% beta 1, 37% beta 2) did not significantly differ between mature and old rats. To summarize, aging from 4 to 24 mo in the Fischer 344 rat is associated with 1) a decrease in AV nodal beta-AR density with no change in affinity; 2) no change in volume of the compact region of the AV node; 3) no change in beta-AR subtype ratio in the AV node, left ventricle, or right ventricle; and 4) no change in either RV or LV beta-AR density.

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31

Belyanin, Dmitriy, Sergey Zhmodik, Evgeniya Airiyants y Ivan Kirichenko. "Local distribution of cobalt and selective enrichment of platinum in oceanic ferromanganese nodules". E3S Web of Conferences 98 (2019): 05002. http://dx.doi.org/10.1051/e3sconf/20199805002.

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The distribution of cobalt in the structure of ferromanganese nodules (FMN) was studied using beta-autoradiography. In some cases, the content of element increased in the outer part of the nodules, or in thin layers within the nodules. Layered type of cobalt distribution in FMN indicates changing conditions in deposition during their formation, in particular also the living conditions of microorganisms known to inhabit oceanic ferromanganese nodules. Experimental studies suggested that colonies of micromycetes living at the surface of the nodules can have an important impact on the selective accumulation of platinum and other elements in FMN.

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32

Fava, R. A., N. J. Olsen, A. E. Postlethwaite, K. N. Broadley, J. M. Davidson, L. B. Nanney, C. Lucas y A. S. Townes. "Transforming growth factor beta 1 (TGF-beta 1) induced neutrophil recruitment to synovial tissues: implications for TGF-beta-driven synovial inflammation and hyperplasia." Journal of Experimental Medicine 173, n.º 5 (1 de mayo de 1991): 1121–32. http://dx.doi.org/10.1084/jem.173.5.1121.

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We have studied the consequences of introducing human recombinant transforming growth factor beta 1 (hrTGF-beta 1) into synovial tissue of the rat, to begin to better understand the significance of the fact that biologically active TGF-beta is found in human arthritic synovial effusions. Within 4-6 h after the intra-articular injection of 1 microgram of hrTGF-beta 1 into rat knee joints, extensive recruitment of polymorphonuclear leukocytes (PMNs) was observed. Cytochemistry and high resolution histological techniques were used to quantitate the influx of PMNs, which peaked 6 h post-injection. In a Boyden chamber assay, hrTGF-beta 1 at 1-10 fg/ml elicited a chemotactic response from PMNs greater in magnitude than that evoked by FMLP, establishing that TGF-beta 1 is an effective chemotactic agent for PMNs in vitro as well as in vivo. That PMNs may represent an important source of TGF-beta in inflammatory infiltrates was strongly suggested by a demonstration that stored TGF-beta 1 was secreted during phorbol myristate acetate-stimulated degranulation in vitro. Acid/ethanol extracts of human PMNs assayed by ELISA contained an average of 355 ng of TGF/beta 1 per 10(9) cells potentially available for secretion during degranulation of PMNs. [3H]Thymidine incorporation in vivo and autoradiography of tissue sections revealed that widespread cell proliferation was triggered by TGF-beta 1 injection. Synovial lining cells and cells located deep within the subsynovial connective tissue were identified as sources of at least some of the new cells that contribute to TGF-beta 1-induced hyperplasia. Our results demonstrate that TGF-beta is capable of exerting pathogenic effects on synovial tissue and that PMNs may represent a significant source of the TGF-beta present in synovial effusions.

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33

Helqvist, Steffen, Birgit Sehested Hansen, Jesper Johannesen, Henrik Ullits Andersen, Jens Høiriis Nielsen y Jørn Nerup. "Interleukin 1 induces new protein formation in isolated rat islets of Langerhans". Acta Endocrinologica 121, n.º 1 (julio de 1989): 136–40. http://dx.doi.org/10.1530/acta.0.1210136.

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Abstract. It is hypothesized that interleukin 1 induces toxic free radical formation in pancreatic beta-cells leading to beta-cell degeneration and destruction. Therefore, isolated rat pancreatic islets were examined for interleukin 1 and heat shock induced proteins. After exposure to human interleukin 1β (0.015 to 10 μg/1) or heat (40°C) for up to 24 h, islets were labelled with 35S-methionine and solubilized. Islets proteins were analysed by SDS-polyacrylamide gel electrophoresis. By autoradiography it was shown that both interleukin 1 and heat exposure induced the formation of a 70 kD protein. Further, interleukin 1 induced the formation of two proteins of 32 and 80 kD, respectively, which was not seen after heat exposure. Possibly, the 70 kD protein is a member of the heat shock protein 70 family, participating in unspecific cellular defence and maybe free radical scavenging. Other candidates are the superoxide radical scavenging enzyme manganous superoxidedismutase, MHC class II molecules, and heme oxygenase.

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34

Crothers, J. M., D. C. Chow, M. L. Scalley y J. G. Forte. "In vivo trafficking of nascent H(+)-K(+)-ATPase in rabbit parietal cells". American Journal of Physiology-Gastrointestinal and Liver Physiology 269, n.º 6 (1 de diciembre de 1995): G883—G891. http://dx.doi.org/10.1152/ajpgi.1995.269.6.g883.

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Protein metabolic labeling in vivo was used to determine a time course for trafficking of nascent H(+)-K(+)-adenosinetriphosphatase (H(+)-K(+)-ATPase) from endoplasmic reticulum (ER) to mature tubulovesicles in parietal cells. Stomachs of cimetidine-treated rabbits were taken 15-90 min after injection of [35S]methionine/cysteine, and mucosal microsomes were fractionated on sucrose gradients for analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, Western blot, and autoradiography. After 15 min, labeled alpha-subunit peaked at approximately 1.14 g/ml, matching the distribution of the high-mannose beta-subunit precursor, "pre-beta." After 30 min, most labeled alpha-subunit was in a peak at approximately 1.10 g/ml, considered to be Golgi. By 90 min, most labeled alpha-subunit was in a light peak, at approximately 1.07 g/ml, aligned with the major peak of total H(+)-K(+)-ATPase previously characterized as mature tubulovesicles. From material enriched in pre-beta, alpha-subunit was coprecipitated with pre-beta by a terminal mannose-specific lectin, Galanthus nivalis agglutinin, in the same ratio as the mature alpha:beta ratio. Thus alpha- and beta-subunits associated early in the ER. This is the first use of protein metabolic labeling to study early trafficking of the H(+)-K(+)-ATPase in vivo. The techniques may be usefully applied to examining changes in H(+)-K(+)-ATPase synthetic rate in response to various pharmacological treatments and studying the divergent pathways for nascent H(+)-K(+)- and Na(+)-K(+)-ATPases.

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35

Clark, S. A., W. E. Stumpf, M. Sar y H. F. DeLuca. "1,25-Dihydroxyvitamin D3 target cells in immature pancreatic islets". American Journal of Physiology-Endocrinology and Metabolism 253, n.º 1 (1 de julio de 1987): E99—E105. http://dx.doi.org/10.1152/ajpendo.1987.253.1.e99.

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Target cells of 1,25-dihydroxyvitamin D3 were identified by autoradiography in islets from rats of different ages. Nuclei of pancreatic islet cells selectively concentrated 1,25-[3H]dihydroxyvitamin D3 but not 25-[3H]hydroxyvitamin D3 or 24,25-[3H]dihydroxyvitamin D3. Developmental studies of pancreatic islets indicated that target cells, as revealed by significant nuclear concentration of 1,25-[3H]dihydroxyvitamin D3, are present in islet cells of fetal rats. The percentage of islet cells that concentrated 1,25-[3H]dihydroxyvitamin D3 increased from 10 to 15% in the fetus to 60% at 1 day of age. Immunocytochemical staining indicated that insulin-containing cells but not glucagon or somatostatin cells concentrated 1,25-[3H]dihydroxyvitamin D3. Peak uptake of 1,25-[3H]dihydroxyvitamin D3 was calculated to be 400 pmol/mg DNA, with no significant difference in nuclear accumulation between islet cells from neonatal and adult rats or between islets in vivo and isolated islets in vitro. The results of these studies indicate that 1,25-[3H]dihydroxyvitamin D3 target cells are present in islets before pancreatic beta-cells are morphologically or functionally mature; islet beta-cells concentrate 1,25-dihydroxyvitamin D3, but not 25-hydroxyvitamin D3 or 24,25-dihydroxyvitamin D3. We conclude that only the 1,25-dihydroxyvitamin D3 metabolite of vitamin D is accumulated by nuclei of developing and mature beta-cells and suggest that 1,25-dihydroxyvitamin D3 plays a role in the maturation of islet beta-cells.

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36

Hall, S. W., J. LaMarre, L. B. Marshall, M. A. Hayes y S. L. Gonias. "Binding of transforming growth factor-β1 to methylamine-modified α2-macroglobulin and to binary and ternary α2-macroglobulin-proteinase complexes". Biochemical Journal 281, n.º 2 (15 de enero de 1992): 569–75. http://dx.doi.org/10.1042/bj2810569.

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The binding of 125I-labelled transforming growth factor-beta 1 (TGF-beta 1) to human alpha 2-macroglobulin (alpha 2M) was studied by native PAGE and autoradiography. TGF-beta 1 bound preferentially to alpha 2M-methylamine and minimally, if at all, to native alpha 2M. Preparations of alpha 2M-proteinase complex were generated by incubating a standard concentration of alpha 2M (0.4 microM) with different concentrations of trypsin, chymotrypsin or neutrophil elastase (0.04-2.0 microM). The 125I-TGF-beta 1-binding activity depended on the initial ratio of active proteinase to alpha 2M, or r value, used to form the alpha 2M-proteinase complex. With all three proteinases, r values of 2 or greater yielded preparations with unchanged or decreased TGF-beta 1-binding activity relative to native alpha 2M. By contrast, r values near 1 yielded preparations with significantly increased TGF-beta 1-binding activity. The results of [3H]thymidine-incorporation studies performed in mouse keratinocytes were consistent with the 125I-TGF-beta-binding experiments. alpha 2M-trypsin and alpha 2M-chymotrypsin prepared at an r value of 1.0 counteracted the activity of TGF-beta 1, whereas the equivalent complexes prepared at an r value of 3.0 had no effect. As determined by SDS/PAGE, 125I-TGF-beta 1 binding to alpha 2M-methylamine was at least 80% non-covalent. Reaction of alpha 2M-methylamine with iodoacetamide or 5,5′-dithiobis-(2-nitrobenzoic acid) decreased the percentage of covalent binding but had no effect on total binding. Neuraminidase treatment had no effect on the binding of 125I-TGF-beta 1 to alpha 2M-methylamine. Cleavage of the ‘bait regions’ in alpha 2M-methylamine by prolonged treatment with trypsin also had no effect. These studies suggest that TGF-beta 1 binding to alpha 2M is enhanced by conformational change in the proteinase inhibitor resulting from reaction with proteinase or amine. If both proteinase-binding sites in a single alpha 2M molecule are occupied, TGF-beta 1-binding activity is decreased or perhaps eliminated.

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37

Borth, W., A. Urbanski, R. Prohaska, M. Susanj y TA Luger. "Binding of recombinant interleukin-1 beta to the third complement component and alpha 2-macroglobulin after activation of serum by immune complexes". Blood 75, n.º 12 (15 de junio de 1990): 2388–95. http://dx.doi.org/10.1182/blood.v75.12.2388.2388.

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Abstract Activation of human normal serum with tetanus/antitetanus immune complexes (TAT-IC) resulted in increased binding of 125I-labeled interleukin-1 beta (IL-1 beta) to serum factors, as opposed to untreated serum. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) followed by autoradiography showed labeling of two large molecular mass factors of an apparent molecular weight (Mr) of 200,000 and 400,000, respectively. These complexes could be dissociated by reduction. No complexes were formed when reducing compounds were added to serum-TAT-IC-125I-IL-1 beta mixtures. Complex formation was largely prevented by alkylating compounds. Molecular sieve chromatography of TAT-IC-activated serum confirmed that 125I-IL-1 beta became bound to high Mr serum proteins. Fractions containing high molecular 125I-IL-1 serum protein complexes partially retained IL-1- like activity since they induced proliferation of an IL-1-dependent murine T helper (D10G4) cell lineage. The 125I-IL-1 beta binding factors could be immunoprecipitated from TAT-IC-activated serum 125I-IL- 1 beta solutions by antisera to alpha 2-macroglobulin (alpha 2M) or to the third complement component (C3). SDS-PAGE of the immunoprecipitates showed radioactive bands corresponding to the expected Mr resulting from complex formation between 125I-IL-1 beta and these two proteins. Treatment of purified plasma alpha 2M and C3 with trypsin or activation with methylamine, which causes cleavage of the internal thiol ester and the appearance of free thiol groups in these proteins, mediated binding of 125I-IL-1 beta to alpha 2M and C3b. The results suggest that cleavage of the internal thiol ester in C3 and alpha 2M makes these plasma proteins susceptible to binding of 125I-IL-1 beta and that free thiol groups do play a role in the formation of 125I-IL-1 beta plasma protein complexes. Activated C3 and alpha 2M may function as IL-1 beta carrier proteins in biologic fluids, in addition to their other physiologic roles.

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38

Borth, W., A. Urbanski, R. Prohaska, M. Susanj y TA Luger. "Binding of recombinant interleukin-1 beta to the third complement component and alpha 2-macroglobulin after activation of serum by immune complexes". Blood 75, n.º 12 (15 de junio de 1990): 2388–95. http://dx.doi.org/10.1182/blood.v75.12.2388.bloodjournal75122388.

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Activation of human normal serum with tetanus/antitetanus immune complexes (TAT-IC) resulted in increased binding of 125I-labeled interleukin-1 beta (IL-1 beta) to serum factors, as opposed to untreated serum. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) followed by autoradiography showed labeling of two large molecular mass factors of an apparent molecular weight (Mr) of 200,000 and 400,000, respectively. These complexes could be dissociated by reduction. No complexes were formed when reducing compounds were added to serum-TAT-IC-125I-IL-1 beta mixtures. Complex formation was largely prevented by alkylating compounds. Molecular sieve chromatography of TAT-IC-activated serum confirmed that 125I-IL-1 beta became bound to high Mr serum proteins. Fractions containing high molecular 125I-IL-1 serum protein complexes partially retained IL-1- like activity since they induced proliferation of an IL-1-dependent murine T helper (D10G4) cell lineage. The 125I-IL-1 beta binding factors could be immunoprecipitated from TAT-IC-activated serum 125I-IL- 1 beta solutions by antisera to alpha 2-macroglobulin (alpha 2M) or to the third complement component (C3). SDS-PAGE of the immunoprecipitates showed radioactive bands corresponding to the expected Mr resulting from complex formation between 125I-IL-1 beta and these two proteins. Treatment of purified plasma alpha 2M and C3 with trypsin or activation with methylamine, which causes cleavage of the internal thiol ester and the appearance of free thiol groups in these proteins, mediated binding of 125I-IL-1 beta to alpha 2M and C3b. The results suggest that cleavage of the internal thiol ester in C3 and alpha 2M makes these plasma proteins susceptible to binding of 125I-IL-1 beta and that free thiol groups do play a role in the formation of 125I-IL-1 beta plasma protein complexes. Activated C3 and alpha 2M may function as IL-1 beta carrier proteins in biologic fluids, in addition to their other physiologic roles.

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39

Hellberg, Sanna, Johanna Silvola, Heidi Liljenbäck, Max Kiugel, Olli Eskola, Harri Hakovirta, Sohvi Hörkkö et al. "Amyloid-Targeting PET Tracer [18F]Flutemetamol Accumulates in Atherosclerotic Plaques". Molecules 24, n.º 6 (19 de marzo de 2019): 1072. http://dx.doi.org/10.3390/molecules24061072.

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Atherosclerosis is characterized by the accumulation of oxidized lipids in the artery wall, which triggers an inflammatory response. Oxidized low-density lipoprotein (ox-LDL) presents amyloid-like structural properties, and different amyloid species have recently been recognized in atherosclerotic plaques. Therefore, we studied the uptake of the amyloid imaging agent [18F]Flutemetamol in atherosclerotic plaques. The binding of [18F]Flutemetamol to human carotid artery plaque was studied in vitro. In vivo uptake of the tracer was studied in hypercholesterolemic IGF-II/LDLR−/−ApoB100/100 mice and C57BL/6N controls. Tracer biodistribution was studied in vivo with PET/CT, and ex vivo by gamma counter and digital ex vivo autoradiography. The presence of amyloid, ox-LDL, and macrophages in the plaques was examined by immunohistochemistry. [18F]Flutemetamol showed specific accumulation in human carotid plaque, especially in areas positive for amyloid beta. The aortas of IGF-II/LDLR−/−ApoB100/100 mice showed large thioflavin-S-positive atherosclerotic plaques containing ox-LDL and macrophages. Autoradiography revealed 1.7-fold higher uptake in the plaques than in a lesion-free vessel wall, but no difference in aortic tissue uptake between mouse strains were observed in the in vivo PET/CT. In conclusion, [18F]Flutemetamol binds to amyloid-positive areas in human atherosclerotic plaques. Further studies are warranted to clarify the uptake mechanisms, and the potential of the tracer for in vivo imaging of atherosclerosis in patients.

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40

Bateman, J. E., J. F. Connolly y R. Stephenson. "High speed quantitative digital beta autoradiography using a multistep avalanche detector and an Apple II microcomputer". Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 241, n.º 1 (noviembre de 1985): 275–89. http://dx.doi.org/10.1016/0168-9002(85)90546-7.

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41

Barthe, N., K. Chatti, P. Coulon, S. Maı̂trejean y B. Basse-Cathalinat. "Recent technologic developments on high-resolution beta imaging systems for quantitative autoradiography and double labeling applications". Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 527, n.º 1-2 (julio de 2004): 41–45. http://dx.doi.org/10.1016/j.nima.2004.03.014.

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42

Saffitz, J. E. y S. B. Liggett. "Subcellular distribution of beta 2-adrenergic receptors delineated with quantitative ultrastructural autoradiography of radioligand binding sites." Circulation Research 70, n.º 6 (junio de 1992): 1320–25. http://dx.doi.org/10.1161/01.res.70.6.1320.

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43

Barnes, J. L., K. A. Woodruff, S. P. Levine y H. E. Abboud. "Inhibition of mesangial cell proliferation by platelet factor 4." Journal of the American Society of Nephrology 7, n.º 7 (julio de 1996): 991–98. http://dx.doi.org/10.1681/asn.v77991.

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Platelet factor 4(PF4), an abundant platelet secretory product, is a strong candidate for modulating glomerular pathology. Because PF4 might be released from platelets and influence intrinsic cell growth during glomerular injury, the effect of PF4 on fetal calf serum- and platelet-derived growth factor (PDGF)-induced mesangial cell mitogenesis was examined. Mitogenesis was measured as the amount of 3H-thymidine incorporated into acid-precipitable material as well as by autoradiography. The effect of PF4 on mesangial cell expression of mRNA for PDGF A chain and transforming growth factor-beta (TGF-beta 1) was also examined. Fetal calf serum (10%)- and PDGF (10 ng/mL)-stimulated increases in mesangial cell 3H-thymidine incorporation were inhibited by incremental concentrations of PF4 (1 to 25 micrograms/mL) showing a maximum reduction of approximately 80% at 25 micrograms/mL of PF4. PF4 was effective when added 24 h before and 1, 4, and 8 h, but not 16 h after the addition of PDGF, indicating that inhibition occurred at delayed events in cell-cycle regulation. PF4 inhibited PDGF-induced increments in mRNA encoding PDGF A chain and TGF-beta 1. Also, PF4 did not interfere with PDGF receptor binding. The results of this study show that PF4 is a negative regulator of mesangial cell proliferation and suggest an interference in cell growth by pathways associated with modulation of the autocrine growth factors PDGF and TGF-beta 1.

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44

Alibardi, Lorenzo. "The Periodic Replacement of Adhesive Setae in Pad Lamellae of Climbing Lizards Is Driven by Patterns of Corneous Layer Growth". Journal of Developmental Biology 11, n.º 1 (30 de diciembre de 2022): 3. http://dx.doi.org/10.3390/jdb11010003.

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The adhesive digital pads in some gecko and anoline lizards are continuously utilized for movements on vertical surfaces that may determine wear and a decrease of adhesion efficiency. The pads are formed by lamellae bearing adhesive setae that are worn out following frequent usage and are replaced by new inner setae that maintain an efficient adhesion. Whether the extensive usage of adhesive setae determines a higher shedding frequency in the digital pads with respect to other body regions remains unknown. Setae replacement has been analyzed in embryos and adult lizards using autoradiography and 5BrdU-immunohistochemistry. The observation strongly suggests that during development and epidermal renewal in adult lamellae, there is a shifting of the outer setae toward the apex of the lamella. This movement is likely derived from the continuous addition of proteins in the beta- and alpha-layers sustaining the outer setae while the inner setae are forming. Ultrastructural and in situ hybridization studies indicate that the thin outer beta- and alpha-layers still contain mRNAs and ribosomes that may contribute to the continuous production of corneous beta proteins (CBPs) and keratins for the growth of the free margin at the apex of the lamella. This process determines the apical shifting and release of the old setae, while the new inner setae formed underneath becomes the new outer setae.

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45

Hawkins, R. A., A. M. Mans y D. W. Davis. "Regional ketone body utilization by rat brain in starvation and diabetes". American Journal of Physiology-Endocrinology and Metabolism 250, n.º 2 (1 de febrero de 1986): E169—E178. http://dx.doi.org/10.1152/ajpendo.1986.250.2.e169.

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The rate of ketone body (beta-hydroxybutyrate and acetoacetate) metabolism was measured in individual cerebral structures of fed, starved, and diabetic rats. This was done by infusing beta-[3-14C]hydroxybutyrate intravenously and measuring the incorporation of 14C into brain by quantitative autoradiography. The capacity of the brain to use ketone bodies, expressed as plasma clearance, increased in starvation and diabetes by approximately 50-60%. Plasma clearance was near maximal after 2 days starvation and was not significantly increased after 4 days starvation, 6 days of diabetes or 28 days of diabetes. In all situations the ketone bodies provided only a modest amount of fuel for brain energy metabolism; 3.2% after 2 days starvation and 6.5 and 9.9% after 6 and 28 days of diabetes. The fraction of their energy requirement which the various structures could derive from the ketone bodies differed widely. In general the telencephalon made greatest use of ketone bodies, whereas the hindbrain used least. There was no correlation between the energy requirement of structures (estimated from glucose use in fed rats) and the fraction of energy they could derive from ketone bodies.

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46

Zhang, R. S., P. H. Guth, O. U. Scremin y G. Chaudhuri. "H2 gas clearance technique for separating rat uterine blood flow into endometrial and myometrial components". American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 268, n.º 2 (1 de febrero de 1995): R569—R575. http://dx.doi.org/10.1152/ajpregu.1995.268.2.r569.

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The H2 gas clearance technique was employed to measure uterine blood flow (UBF) in ovariectomized rats. A needle-type platinum electrode (125 microns diam) was inserted into the rat uterine wall to measure the tissue blood flow surrounding the electrode. The electrode can be placed in individual layers of the uterus to measure the endometrial blood flow (EBF) or the myometrial blood flow (MBF). By use of this technique, baseline EBF and MBF were 37.8 +/- 3.53 (n = 21) and 47.2 +/- 4.56 (n = 5) ml.min-1.100 g-1, respectively, with an EBF/MBF ratio of 0.8. Intravenous bolus injection of 17 beta-estradiol (1 microgram/kg) induced a significant increase in UBF. Phenylephrine, an alpha-adrenergic receptor agonist, reduced UBF. In some animals, a second platinum electrode was used to measure gastric mucosal blood flow simultaneously with UBF. While 17 beta-estradiol selectively increased UBF, pentagastrin selectively increased gastric mucosal blood flow. To further validate the baseline UBF distribution between endometrial and myometrial layers, iodo[14C]antipyrine autoradiography was employed. With the iodo[14C]antipyrine technique, the EBF/MBF ratio was 0.91 +/- 0.07 (n = 5), which is similar to that obtained with the H2 gas clearance technique.

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47

SATO, Tachio, Takehiko FUJIWARA, Yoshinao ABE, Masatoshi ITOH, Hiroshi FUKUDA, Jun HATAZAWA, Kazuo KUBOTA, Tatsuo IDO y Taiju MATSUZAWA. "Double tracer whole body autoradiography using a short-lived positron emitter and a long-lived .BETA. emitter." RADIOISOTOPES 38, n.º 1 (1989): 7–12. http://dx.doi.org/10.3769/radioisotopes.38.7.

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48

Muntz, K. H., T. A. Calianos, D. T. Vandermolen, J. T. Willerson y L. M. Buja. "Differences in affinity of cardiac beta-adrenergic receptors for [3H]dihydroalprenolol". American Journal of Physiology-Heart and Circulatory Physiology 250, n.º 3 (1 de marzo de 1986): H490—H497. http://dx.doi.org/10.1152/ajpheart.1986.250.3.h490.

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We performed quantitative light microscopic autoradiography of [3H]dihydroalprenolol (DHA) binding to frozen sections of canine myocardium to test the hypothesis that there are differences in the density or affinity of beta-adrenergic receptors on various tissue compartments. In one study, with concentrations of [3H]DHA from 0.34 to 5.1 nM, specific binding to cardiac myocytes was saturable, whereas nonspecific binding was linear with ligand concentration. Arterioles had more specific grain counts than muscle cells (P less than 0.0001), and Scatchard analysis showed that the arterioles had a much higher affinity for [3H]DHA than myocytes. In a second study with lower concentrations of [3H]DHA (0.19-1.98 nM), binding to the arterioles saturated, whereas binding to the cardiac myocytes did not. Specific binding to arterioles was significantly higher (P less than 0.0001) than binding to myocytes at all concentrations of [3H]DHA. The dissociation constants for the subendocardial and subepicardial myocytes were 1.57 and 1.71 nM, respectively, while the dissociation constant for the arterioles was 0.26 nM. The maximum number of binding sites was 911 grains/0.9 X 10(-2) mm2 for subepicardial myocytes, 936 for subendocardial myocytes, and 986 for arterioles. The large nerves accompanying an epicardial artery also demonstrated specific [3H]DHA binding. Thus this study has demonstrated major differences in the distribution and affinity of beta-adrenergic receptors, which may help to explain various physiological responses to beta-adrenergic stimulation.

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49

Williams, L. M., P. E. Ballmer, L. T. Hannah, I. Grant y P. J. Garlick. "Changes in regional protein synthesis in rat brain and pituitary after systemic interleukin-1 beta administration". American Journal of Physiology-Endocrinology and Metabolism 267, n.º 6 (1 de diciembre de 1994): E915—E920. http://dx.doi.org/10.1152/ajpendo.1994.267.6.e915.

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A convenient and sensitive method has been developed for measuring changes in protein synthesis in discrete areas of the brain and pituitary of conscious freely moving rats. A single injection of high-concentration low-specific activity L-[35S]methionine is given to flood amino acid precursor pools, thereby equalizing the specific activity of the L-[35S]methionine throughout the tissue. Unincorporated L-[35S]methionine is removed from cryostat sections by treatment with perchloric acid (2%) before quantitative autoradiography. The sensitivity of this technique is demonstrated by the detection of changes in protein synthesis in regions of the brain and pituitary after systemic administration of interleukin-1 beta, a cytokine that has centrally mediated effects but which is not thought to cross the blood-brain barrier. Areas of the brain found to exhibit significant increases in protein synthesis were the subfornical organ, the choroid plexus, the medial habenular, the dentate gyrus, and the anterior and posterior lobes of the pituitary. In the brain, the cingulate cortex and the pineal gland showed significant decreases in the rate of protein synthesis.

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Kim, N. N., F. J. Villarreal, M. P. Printz, A. A. Lee y W. H. Dillmann. "Trophic effects of angiotensin II on neonatal rat cardiac myocytes are mediated by cardiac fibroblasts". American Journal of Physiology-Endocrinology and Metabolism 269, n.º 3 (1 de septiembre de 1995): E426—E437. http://dx.doi.org/10.1152/ajpendo.1995.269.3.e426.

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Cultured neonatal rat cardiac fibroblasts (NF) and myocytes (NM) were used to examine the distribution of angiotensin II (ANG II) receptors and the potential role of NF in mediating the trophic response to ANG II in the heart. In NM preparations cultured for 2-5 days, specific binding to 125I-ANG II was < 10% of the specific binding in cultured NF. Binding assays, immunocytochemistry, and autoradiography in NM cultured for > 5 days identified two populations of cells, one with fibroblast-like morphology and high density of ANG II receptors and another with low binding, comparable to NM cultures at day 5 or earlier. Conditioned medium (CM) from untreated NF increased cell surface area and net [3H]leucine (Leu) incorporation 1.4-fold in NM. CM from ANG II-treated NF enhanced [3H]Leu incorporation 2.2-fold in NM. This potentiating effect of ANG II was inhibited by losartan and was absent when ANG II was added directly to NM. In addition, studies using antibodies and bioassay for transforming growth factor-beta 1 (TGF-beta 1) suggested that TGF-beta 1 does not mediate the trophic effects of ANG II on NM. We conclude that ANG II receptors are localized predominantly on NF and that ANG II can indirectly stimulate hypertrophy of NM by stimulating NF to produce a transferrable factor(s). These data suggest that cardiac fibroblasts may play a critical role in mediating the hypertrophic response to ANG II in the rat heart.

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