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1.
This study was designed to investigate the mitotic response to wounding in the rat thyroid. The spatial distribution of mitotic activity 48 hr after incision of the thyroid isthmus, or mere exposure of the gland (sham-operation), was assessed using a stathmokinetic technique. Incision resulted in a 66-fold increase over normal in metaphase index adjacent to the wound, falling over 2 mm to a stable 13-fold elevation. Sham-operation produced a smaller response with a complete return to normal levels over 1-1 X 5 mm. The results demonstrate that there is a dramatic localized mitotic response to wounding in the thyroid together with a smaller generalized response. Further, the response to sham-operation indicates that thyroid follicular cells respond to a diffusible 'wound hormone'. We suggest that this may be a major mechanism mediating reparative growth in this gland. 相似文献
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The effect of lincocin (a plastid protein synthesis inhibitor) treatment on the greening process of bean (Phaseolus vulgaris L.) leaves have been studied. In comparison with control leaves treated ones had a decreased rate of chloroplast development. They had a marked chlorophyll deficiency and a decreased chlorophyll a/b ratio. Some long and short wavelength forms of chlorophyll a were lacking as evidenced from the absorption spectra at 25°C and the fluorescence spectra at 77°K. The –14CO2 fixation was inhibited by 80–90% in treated leaves. The fluorescence induced by the measuring light was greater in the treated leaves than in the control ones, and the kinetics of the decline of the relative fluorescence intensity were also different. Electron microscopic studies showed macrogranum-like structures and incomplete membrane vesicles in the treated plastids. After longer treatment a destruction of membranes was observed. The results indicate some structural and functional membrane deficiencies and instability of the membranes. 相似文献
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Herman Justin Park Brian Awsare Bharat West Frances Crittendon Denine Evans Lilah Harach Mary Karp Julie Peedin Alexis LaNoue Marianna Goldsmith Barbara Warnick Eugene Baram Michael 《BMC anesthesiology》2019,19(1):1-6
Hypoxic preconditioning (HPC) may protect multiple organs from various injuries. We hypothesized that HPC would reduce lung injury in patients undergoing thoracoscopic lobectomy. In a prospective randomized controlled trial, 70 patients undergoing elective thoracoscopic lobectomy were randomly allocated to the HPC group or the control group. Three cycles of 5-min hypoxia and 3-min ventilation applied to the nondependent lung served as the HPC intervention. The primary outcome was the PaO2/FiO2 ratio. Secondary outcomes included postoperative pulmonary complications, pulmonary function, and duration of hospital stay. HPC significantly increased the PaO2/FiO2 ratio compared with the control at 30 min after one-lung ventilation and 7 days after operation. Compared with the control, it also significantly improved postoperative pulmonary function and markedly reduced the postoperative hospital stay duration. No significant differences between groups were observed in the incidence of pulmonary complications or overall postoperative morbidity. HPC improves postoperative oxygenation, enhances the recovery of pulmonary function, and reduces the duration of hospital stay in patients undergoing thoracoscopic lobectomy. This study was registered in the Chinese Clinical Trial Registry (ChiCTR-IPR-17011249) on April 27, 2017. 相似文献
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Both CD4(+) T cells and CD8(+) T cells are required for iodine accelerated thyroiditis in NOD mice 总被引:5,自引:0,他引:5
Hutchings PR Verma S Phillips JM Harach SZ Howlett S Cooke A 《Cellular immunology》1999,192(2):113-121
The nonobese diabetic (NOD) mouse, a spontaneous animal model for insulin-dependent diabetes mellitus, displays a tendency in common with human diabetic populations to develop autoimmune thyroiditis although incidence and severity of thyroid lesions vary widely among different colonies around the world. A congenic strain of NOD mice bearing I-Ak on a NOD background (NOD-H2(h4)) has recently been derived and displays a much greater tendency to develop thyroiditis and autoantibodies to mouse thyroglobulin (MTg) although it is free of diabetes. Both thyroid infiltrates and autoantibody formation are accelerated and enhanced in NOD-H2(h4) mice by increased iodine intake. The effect of increased iodine intake on NOD mice themselves has not been directly investigated although a recent study of these animals given high or low doses of iodine showed no follicular destruction unless the mice were first rendered goitrous by iodine deprivation. We found that dietary iodine increased both the incidence and the severity of thyroid lesions in our NOD mice although autoantibodies to MTg were absent. NOD background genes appear to be essential for the development of these lesions, which were maximal after 4 weeks of iodine administration and showed no significant regression when the iodine was stopped. Furthermore, our studies show for the first time that both CD4(+) and CD8(+) T cells are necessary for the development of this accelerated but essentially spontaneous murine thyroid disease. 相似文献
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In this paper, we introduce fractional-order into a model of HIV-1 infection of CD4+ T cells. We study the effect of the changing the average number of viral particles N with different sets of initial conditions on the dynamics of the presented model. Generalized Euler method (GEM) will be
used to find a numerical solution of the HIV-1 infection fractional order model. 相似文献
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H R Harach 《Acta anatomica》1985,122(4):249-253
A systematic anatomical study of 100 adult human thyroids from autopsies was undertaken for the presence of solid cell nests (SCN). SCN were mainly located in the middle third, with a slight tendency to the upper third, of the lateral thyroid lobes, and placed along a central to paracentral and slightly dorsal longitudinal axis. Immunohistochemical studies for thyroglobulin revealed positive staining in follicular cells connected to SCN and, occasionally, in isolated cells lying within solid clusters from SCN. The anatomical position SCN showed in the present survey is comparable to that shown by the ultimobranchial body (UB) vestiges of human fetuses. The presence of thyroglobulin-positive cells within solid clusters, together with the existence of follicular cells connected to SCN, suggest that SCN may also be a probable source of follicular epithelium as occurs with the UB of some mammals. 相似文献
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Expression of 'visceral' cytokeratin and ultrastructural findings in solid cell nests of the thyroid
Solid cell nests of the thyroid display histological features that resemble squamous epithelium. In the present study we investigated whether these ultimobranchial nests express a renal tubular cell cytokeratin which is found to be widely distributed in epithelia but does not appear in squamous tissue. All 17 solid cell nests studied, in contrast to squamous epithelium lining an intrathyroid thyroglossal cyst, stained positively for this intermediate filament. These findings, together with the gland-like features shown ultrastructurally by these ultimobranchial remnants, further support the view that solid cell nests of the thyroid should not be regarded as a kind of intrathyroid squamous inclusion. In addition, they were electron-microscopically comparable to mammalian ultimobranchial tissue. 相似文献
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Sexual size dimorphism (SSD) is often assumed to be driven by three major selective processes: (1) sexual selection influencing male size and thus mating success, (2) fecundity selection acting on females and (3) inter‐sexual resource division favouring different size in males and females to reduce competition for resources. Sexual selection should be particularly strong in species that exhibit lek polygyny, since male mating success is highly skewed in such species. We investigated whether these three selective processes are related to SSD evolution in grouse and allies (Phasianidae). Male‐biased SSD increased with body size (Rensch’s rule) and lekking species exhibited more male‐biased SSD than nonlekking ones. Directional phylogenetic analyses indicated that lekking evolved before SSD, but conclusions were highly dependent on the body size traits and chosen model values. There was no relationship between SSD and male display agility, nor did resource division influence SSD. Although clutch mass increased with female body size it was not related to the degree of SSD. Taken together, the results are most consistent with the hypothesis that lekking behaviour led to the evolution of male‐biased SSD in Phasianidae. 相似文献