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Yongchuan Chai Yu Wang Hua Qian Bo Yang Chao Wu Jiusheng Chu Tao Yang 《American journal of medical genetics. Part A》2019,179(2):243-248
Waardenburg syndrome (WS) is a genetic disorder characterized by hearing loss and pigmentary abnormalities with variable penetrance. Though heterozygous mutations in MITF are a major cause for Waardenburg syndrome type 2 (WS2), homozygous mutations in this gene and the associated phenotype have been rarely characterized. In this study, we identified a novel p.R223H mutation in MITF in a Chinese Han family with variable WS features. Both parents carried a heterozygous p.R223H mutation. They had normal hearing, and premature greying of the hair is their only pigmentary abnormality. In contrast, their two children both carried a homozygous p.R223H mutation and had classic WS features including profound hearing loss, heterochromia irides and marked pigmentary abnormalities in hair and skin. Interestingly, the two affected children also have persistent chronic constipation since the neonatal period, symptoms suggestive of Waardenburg syndrome type 4 (WS4). Our study revealed a likely association between homozygous mutations in MITF and WS4, which implies a dosage effect for the underlying pathogenesis mechanism. 相似文献
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目的 观察人工组织神经移植物对陈旧性大鼠坐骨神经缺损的修复作用.方法 切除成年SD大鼠部分左侧坐骨神经,饲养60d形成陈旧性坐骨神经缺损后,以人工组织神经移植物修复缺损,同时设自体神经修复和不修复两对照组.修复术后3个月做神经-肌复合电位、腓肠肌湿重及再生神经形态学检测.结果 人工组织神经移植物修复组实验侧的运动神经传导速度、腓肠肌湿重、移植物远侧再生神经有髓神经纤维髓鞘厚度等结果与自体神经修复组相似.不修复对照组则未记录到神经-肌复合电位,未观察到再生神经纤维结构,腓肠肌湿重明显小于人工组织神经移植组和自体神经移植组.结论 人工组织神经移植物在一定程度上能修复缺损60d的大鼠坐骨神经. 相似文献
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为了观察人工组织神经移植物对大鼠坐骨神经非新鲜损伤的修复作用。我们在成年SD大鼠左侧股中部切除部分坐骨神经制造神经缺损模型。15d后,实验组(9只)用人工组织神经移植物修复神经缺损,自体神经修复作为阳性对照(6只),保持神经缺损为阴性对照(6只)。第二次手术后3个月,电生理学、形态学结果显示实验组的再生神经虽略差于自体对照组,但明显优于缺损对照组,腓肠肌的萎缩形态学指标变化则较接近自体对照组。实验结果表明人工组织神经移植物对已缺损15d的大鼠周围神经具有较好修复作用。 相似文献
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Zheng-Lin Jiang Hisao Yamaguchi Akira Takahashi Shingo Tanabe Noboru Utsuyama Toshitaka Ikehara Keiko Hosokawa Hiroyuki Tanaka Yohsuke Kinouchi Hiroshi Miyamoto 《European journal of applied physiology》1995,70(3):234-239
Cerebral blood volume flow and flow velocity have been reported to increase during dynamic exercise, but whether the two increase in parallel and whether both increases occur as functions of exercise intensity remain unsettled. In this study, blood flow velocity in the common carotid artery was measured using the Doppler ultrasound method in eight healthy male students during graded treadmill exercise. The exercise consisted of stepwise progressive increases and decreases in exercise intensity. The peak intensity corresponded to approximately 85% of maximal oxygen consumption. During this exercise, the heart rate (f
c), mean blood pressure (BP) in the brachial artery and mean blood flow velocity (cc) in the common carotid artery increased as functions of exercise intensity. At the peak exercise intensity, (f
c), BP and cc increased by 134.5%, 20.5% and 51.8% over the control levels before exercise (P < 0.01), respectively. The resistance index (RI) and pulsatility index (PI) were determined from the velocity profile and were expected to reflect the distal cerebral blood flow resistance. The RI and PI increased during the graded exercise, but tended to decrease at the highest levels of exercise intensity. As cc increased with increases in exercise intensity it would be expected that cerebral blood flow would also increase at these higher intensities. It is also suggested that blood flow velocity in the cerebral artery does not proportionately reflect the cerebral blood flow during dynamic exercise, since the cerebral blood flow resistance changes. 相似文献
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《Acta histochemica》2023,125(5):152046
The close interaction between male germ cells and Sertoli cells, a type of somatic cell found in the seminiferous tubules of mammalian testis, is essential for the normal progression of spermatogenesis in mammals. Vimentin is an intermediate filament protein that primarily provides mechanical support, preserves cell shape, and maintains the nuclear position, and it is often used as a marker to identify Sertoli cells. Vimentin is known to be involved in many diseases and aging processes; however, how vimentin is related to spermatogenic dysfunction and the associated functional changes is still unclear. In a previous study, we reported that vitamin E deficiency affected the testes, epididymis, and spermatozoa of mice, accelerating the progression of senescence. In this study, we focused on the Sertoli cell marker vimentin and explored the relationship between the cytoskeletal system of Sertoli cells and spermatogenic dysfunction using testis tissue sections that caused male reproductive dysfunction with vitamin E deficiency. The immunohistochemical analysis showed that the proportion of the vimentin-positive area in seminiferous tubule cross-sections was significantly increased in testis tissue sections of the vitamin E-deficient group compared with the proportion in the control group. The histological analysis of testis tissue sections from the vitamin E-deficient group showed that vimentin-positive Sertoli cells were greatly extended from the basement membrane, along with an increased abundance of vimentin. These findings suggest that vimentin may be a potential indicator for detecting spermatogenic dysfunction. 相似文献
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《Environmental toxicology and pharmacology》2014,37(2):697-704
The objective of this study was to assess potential toxic effects of phenanthrene (PHE) on tissues of clam Venerupis philippinarum using parameters of antioxidant defenses and oxidative stress. Antioxidant biomarkers including ethoxyresorufin-O-deethylase (EROD), glutathione S-transferase (GST), superoxide dismutase (SOD), and glutathione (GSH), as well as DNA damage and lipid peroxidation (LPO) in gills and digestive glands of V. philippinarum, were analyzed after a 1-, 3-, 6-, 10- and 15-day exposure to seawater containing PHE at concentrations of 2, 10, 50 μg/L. The results showed that the activity of most antioxidant enzymes was induced throughout the exposure period, and different trends were detected with time of exposure. The oxidative stress could be obviously caused in the gills and digestive glands under the experimental conditions. Overall, our results show that digestive glands are more sensitive to marine environmental stressors than gills, and GSH is proposed as potential useful biomarker as it showed good correlation with the target contaminant. This could provide useful information for toxic risk assessment of environmental pollutant PHE. 相似文献