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1.
Summary Leydig cells in testes of adult rats were selectively destroyed by a single intraperitoneal injection of ethane dimethane sulphonate. Four days later rats were made unilaterally cryptorchid and 1, 2 and 4 weeks later the histology of the testes was examined by light microscopy and morphometry. After induction of unilateral cryptorchidism, the volume of abdominal compared to scrotal testes was reduced by 45–60% due to rapid impairment of spermatogenesis in abdominal testes. Leydig cells were not present in either scrotal or abdominal testes in the 1-week unilateral crytorchid group. A new generation of foetal-type Leydig cells was observed in scrotal testes of the 2-week unilateral crytorchid group although their total volume per testis estimated by morphometry, was small, being approximately 1 l. In contrast, the abdominal testis exhibited a remarkable proliferation of foetal-type Leydig cells (total volume per testis, 16 l) which predominantly surrounded the peritubular tissues of the seminiferous tubules. A similar morphology and pattern of Leydig cell development was observed in scrotal and abdominal testes of the 4-week unilateral cryptorchid group where total Leydig cell volume was 7 l vs 21 l, respectively. The results show that regeneration of a new population of Leydig cells occurs more rapidly in the abdominal testis than in the scrotal testis of the same animal. These observations suggest the possibility that augmentation of Leydig cell growth is mediated by local intratesticular stimulatory factors within the abdominal testis. Development of new Leydig cells from the peritubular tissue provides circumstantial evidence that the seminiferous tubules and in particular the Sertoli cells, are a likely source of agents that stimulate the growth of Leydig cells.  相似文献   
2.
Zusammenfassung Der Verlauf der Sehbahn und die Lokalisation der optischen Zentren wurden bei Zonotrichia leucophrys gambelii (nordamerikanischer Ammernfink) nach einseitiger Augenexstirpation mit den Techniken von Nauta-Fink-Heimer, Bodian und Bielschowsky erforscht. Die Untersuchungen erstreckten sich über einen Zeitraum von 3 bis zu 120 Tagen nach der Operation. Zonotrichia leucophrys gambelii besitzt ein für Vögel typisches visuelles System. Die Hauptmasse der Optikusfasern endet im Stratum griseum et fibrosum superficiale des Tectum opticum. Weitere zentrale Endgebiete sind: Nucleus geniculatus lateralis, Nucleus lateralis anterior, Nucleus superficialis synencephali, Nucleus externus, tectales Grau und Nucleus ectomamillaris als Kern der basalen optischen Wurzel. Alle Fasern werden im Chiasma opticum total gekreuzt, auch der Tractus isthmo-opticus, ein efferentes Bündel, dessen Ursprung im Nucleus isthmo-opticus zu finden ist. Dieses efferente Fasersystem läßt sich im Stumpf des durchtrennten N. opticus noch 120 Tage nach der Operation gut versilbern. Eine direkte Verbindung von Retina und Hypothalamus war lichtmikroskopisch nicht nachweisbar. Neurosekretorisch aktive Zellen des Hypothalamus können zwar einen engen räumlichen Kontakt mit den optischen Fasern haben, Synapsen sind aber an diesen Stellen nicht zu erkennen. Es werden passagere Opticusfasern beschrieben, die auf dem Weg zum Nucleus lateralis anterior und Nucleus superficialis synencephali den Hypothalamus durchsetzen.
Neurohistological and experimental studies of the visual system in Zonotrichia leucophrys gambelii
Summary The course of the optic pathways and the positions of the optic centers have been investigated with unilaterally enucleated white-crowned sparrows, Zonotrichia leucophrys gambelii, using the techniques of Nauta-Fink-Heimer, Bodian, and Bielachowsky. The investigation involved birds examined 3–120 days after enucleation. The white-crowned sparrow has a typically avian visual system. The major bundles of optic fibers terminate in the stratum griseum et fibrosum superficiale of the tectum opticum. Further terminal areas are the nucleus geniculatus lateralis, nucleus lateralis anterior, nucleus superficialis synencephali, nucleus externus, the tectal gray, and the nucleus ectomamillaris of the basal optic root. There is a complete crossing of all fibers in the chiasma, including those of the tractus isthmo-opticus, an efferent bundle with its origin in the nucleus isthmo-opticus. This efferent fiber system can be well impregnated in the stump of the sectioned optic nerve up to 120 days after the operation. No direct connection between the retina and hypothalamus could be demonstrated by light microscopy. Hypothalamic neurosecretory cells can occur in close contact with optic fibers but no synapses have been recognized. Some optic fibers pass through the hypothalamus enroute to the nucleus lateralis anterior and the nucleus superficialis synencephali.
Mit Unterstützung durch die Deutsche Forschungsgemeinschaft. Herrn Prof. Dr. D.S. Farner, Department of Zoology, University of Washington, Seattle, Wash., danke ich für die Förderung dieser Studien (National Institutes of Health Research Grant No. 5 ROI NB 06187 to Professor D. S. Farner).  相似文献   
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4.
Age-dependent population diffusion with external constraint   总被引:3,自引:0,他引:3  
We present a simple model for age dependent population diffusion when the dynamics is submitted to external constraints. Existence, uniqueness and dependence on the parameters of the solution are discussed.This work has been done within the framework of the cultural agreement between the Universities of Bordeaux and Rome  相似文献   
5.
Summary Somatic hybrid plants regenerated following the fusion of leaf mesophyll protoplasts of Petunia parodii with those isolated from a cell suspension of albino P. inflata. These two species exhibit a unilateral cross-incompatability with a pre-zygotic mode of reproductive isolation preventing hybridizations with P. inflata as the maternal parent. Selection of somatic hybrids relied on the fact that unfused or homokaryon protoplasts of P. parodii did not develop beyond the cell colony stage while those of the putative somatic hybrids and albino P. inflata parent produced callus. Green somatic hybrid calluses were readily identified against the white background of P. inflata following complementation to chlorophyll synthesis proficiency and continued growth in hybrid cells. Shoots, and ultimately flowering plants, were identified as somatic hybrids based on their floral morphology and colour, chromosome number and the fact that they segregated for parental characters. The frequency of somatic hybrid production was comparable to that previously established for two sexually compatible Petunia species.  相似文献   
6.
Gallstone ileus is a rare and potentially serious complication of cholelithiasis. It is defined as a mechanical intestinal obstruction secondary to the presence of a gallstone in the intestinal luz. The most frequent cause is impaction of the calculus in the ileum after passing through a bilioenteric fístula. It has a high morbidity and mortality rate, mainly due to the difficulty and delay in its diagnosis. A retrospective study is presented of 4 cases of gallstone ileus treated between 2013 and 2017 in the Hospital Nuestra Señora del Prado. An analysis was performed on the clinical characteristics, diagnostic tests, and surgical treatment.  相似文献   
7.
The growth arrest and DNA damage‐inducible beta (Gadd45β) protein have been associated with various cellular functions, but its role in progressive renal disease is currently unknown. Here, we examined the effect of Gadd45β deletion on cell proliferation and apoptosis, inflammation, and renal fibrosis in an early chronic kidney disease (CKD) mouse model following unilateral ureteral obstruction (UUO). Wild‐type (WT) and Gadd45β‐knockout (KO) mice underwent either a sham operation or UUO and the kidneys were sampled eight days later. A histological assay revealed that ablation of Gadd45β ameliorated UUO‐induced renal injury. Cell proliferation was higher in Gadd45β KO mouse kidneys, but apoptosis was similar in both genotypes after UUO. Expression of pro‐inflammatory cytokines after UUO was down‐regulated in the kidneys from Gadd45β KO mice, whereas UUO‐mediated immune cell infiltration remained unchanged. The expression of pro‐inflammatory cytokines in response to LPS stimulation decreased in bone marrow‐derived macrophages from Gadd45β KO mice compared with that in WT mice. Importantly, UUO‐induced renal fibrosis was ameliorated in Gadd45β KO mice unlike in WT mice. Gadd45β was involved in TGF‐β signalling pathway regulation in kidney fibroblasts. Our findings demonstrate that Gadd45β plays a crucial role in renal injury and may be a therapeutic target for the treatment of CKD.  相似文献   
8.
目的:探讨承气活血通腑汤联合穴位贴敷治疗粘连性肠梗阻的疗效及对胃肠功能和血清炎性因子的影响。方法:选取2018年2月到2020年7月期间于我院接受诊治的粘连性肠梗阻患者60例。分组方法采用随机数字表法,将入选患者分为对照组(n=30,常规治疗)、研究组(n=30,对照组的基础上给予承气活血通腑汤联合穴位贴敷治疗),对比两组疗效、胃肠功能、炎性因子、住院时间、住院费用、临床症状评分。结果:研究组的临床总有效率较对照组高(P<0.05)。两组治疗12d后血清降钙素原(PCT)、C反应蛋白(CRP)水平较治疗前降低,且研究组较对照组低(P<0.05)。两组治疗12d后腹部胀痛、排便排气、恶心呕吐、口苦口干评分较治疗前降低,且研究组较对照组低(P<0.05)。研究组胃管拔除时间、恢复正常饮食时间均短于对照组(P<0.05)。研究组住院时间短于对照组,住院费用少于对照组(P<0.05)。结论:承气活血通腑汤联合穴位贴敷治疗粘连性肠梗阻的疗效确切,可改善患者临床症状和胃肠功能,促进患者早日恢复,减少住院费用,降低机体炎性因子水平。  相似文献   
9.
Abstract

The paper aims to evaluate the effects caused by a Mandibular Advancement Device (MAD) for Obstructive Sleep Apnoea Syndrome (OSAS) treatment. This study is based on Finite Element Method (FEM) for evaluating the load distribution on temporomandibular joint, especially on the mandibular condyle and disc, and on periodontal ligaments. The stress values on condyle and periodontal ligaments lead authors to consider MAD a safe procedure even for a long period. The obtained results also show the relationship between MAD material and load distribution at the periodontal ligaments. The paper is a step toward future analyses for studying and comparing the effects of MAD features, such as material, shape and dimensions, in order to allow the clinician prescribing the most fitting device.  相似文献   
10.
3-Isobutyroxy-β-ionone (III) is the proposed structure of quiesone, the naturally occurring inhibitor of the germination of Peronospora tabacina conidia. This was synthesized as a racemate and shown to possess qualitatively identical biological activity as quiesone itself. Employing an intermediate of this synthesis, dl-dehydrovomifoliol (VII) was also synthesized.  相似文献   
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