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101.
Pigs of different ages were studied to assess the effect of age on the development of the testes after intra-abdominal transection of the testicular artery and vein. Transection of the testicular artery and vein at different stages of sexual development had a variable effect on the growth and differentiation of the testes. Transection performed at a young age (2 months) had no effect on the development of the testes (previous study). The animals used in this study were between 3 and 12 months (adult) at the time of surgical intervention. Their testes appeared to be more sensitive to disturbance of the main blood supply. The alternative vascular pedicle (vasal artery) was unable to adapt sufficiently to the increased physiological requirements of the testis during development in more than 50% of the animals. The results obtained from adult males indicate that intra-abdominal transection of the testicular vessels invariably has a deleterious effect on the testis. 相似文献
102.
103.
目的通过观察胚龄12、14、16天胎鼠和生后1天的仔鼠的后肾组织体外培养的存活发育情况,与同期在体比较,建立能模拟体内生存环境稳定的肾组织培养模型。方法采用体外培养倒置显微镜观察,光镜连续切片技术结合体视学定量分析方法,观察、检测培养后肾组织的存活情况以及培养前后肾脏皮质的发育状况。结果对同一胚(日)龄小鼠后肾组织随培养时间逐渐发育,直至成熟;且随胚(日)龄的增加,肾组织块存活比率逐渐下降,肾脏皮质的发育呈下降趋势。结论小鼠后肾组织体外培养胚(日)龄越小其存活发育情况越好,E12天取材培养的肾组织与在体发育一致,利用微孔膜肾组织培养是一种简便有效的神经组织体外培养方法。 相似文献
104.
Z. Świderski 《Helminthologia》2007,44(3):130-136
Summary Ultrastructural features of juvenile cestodes (metacestodes) can provide useful characters for phylogenetic and evolutionary
analyses. Until now, however, they have been relatively little utilised (Beveridge 2001, Chervy 2002). The postembryonic development
and structure of fully formed metacestodes were examined in two cyclophyllideans: Taenia parva Baer, 1926 (Taeniidae); and Sobolevitaenia verulamii (Mettrick, 1958) Korniushin, 1972 (Dilepididae). In T. parva, three developmental stages were recognized: (1) an early stage of exogenous budding at the surface of the central vesicle;
(2) a stage of polycephalic cyst development accompanied by segmentation of the growing metacestode strobila and an obvious
decrease in the size of the central vesicle; (3) a fully formed metacestode of the strobilocercus type with 14–24 invaginated
scoleces. The tegument, scolex, subtegumental musculature of the strobilar segments, protonephridial system, calcareous corpuscles
and medullary parenchyma of larvae exhibit general similarity to the same structures in adults at both LM and TEM levels.
The morphogenesis of the metacestode of T. parva is compared with that of polycephalic metacestodes of other Taenia spp. (T. krepkogorski, T. twitchelli and T. endothoracica) and with other asexually multiplying metacestodes (Mesocestoides vogae, hymenolepidids and dilepidids). In S. verulamii, the body of the cysticercoid with invaginated scolex armed with a double crown of rostellar hooks was completely surrounded
by the cercomer, which appears to be separated from the cyst and scolex. The surface of the suckers is covered with a thick
layer of glycocalyx. Five cell types were distinguished in the sections: (1) perikarya of metacestode tegument; (2) glycolgen-storing
parenchymal cells; (3) glandular-type cells with large, electron-dense secretory-like granules; (4) flame cells; and (5) calcareous
corpuscle-forming cells. The surface of the cercomer is covered by elongated microvilli, which evidently differ from characteristic
microtriches covering all other parts of the metacestode surface. The ultrastructure of S. verulamii evidently differs from that of the other dilepidid cestode examined to date, Lateriporus geographicus, the cyst wall of which more resembles cysticercoids of Hymenolepididae than those of Dilepididae. Concluding remarks: Ultrastructural
studies on metacestodes have considerable promise for providing important new characters for phylogenetic analysis. New TEM
data on a great variety of cestode species are urgently needed. Until now, this field has not been exploited in a systematic
fashion. Until more comprehensive studies become available, the current data are not yet amenable to analysis. 相似文献
105.
106.
歼击机飞行员改装体检脊柱病症的医学鉴定 总被引:6,自引:1,他引:5
目的对近几年来我院改装体检歼击机飞行员脊柱病症健康鉴定进行归纳总结。方法收集分析了261例歼击机飞行员体检和X线、CT的影像诊断资料,并对因脊柱病症体检不合格资料进行统计学分析。结果歼击机飞行员体检中,脊柱影像诊断中以腰椎间盘突出(49例)最多,但多数没有相应的临床症状,有20例因脊柱病症不合格,其中腰椎双侧峡部裂伴Ⅰ°滑脱9例,占不合格总数的45%,是不合格的主要原因。结论外科体检中应该重点加强对脊柱的检查,影像诊断应结合症状和脊柱功能作出鉴定,必要时应作随访观察。 相似文献
107.
南海某岛礁作业人员睡眠状况与身心健康状况关系的研究 总被引:2,自引:2,他引:0
目的 研究南海某岛礁作业人员睡眠状况与身心健康状况的关系。方法 由经过统一培训的医务人员连续91d每日逐人逐项当面调查、记录。其中的“指数”指标,采用视觉模糊评分法。结果 随着在礁时阃的延长,作业人员睡眠状况明显变差,其主要影响因素依次为值勤(28.73%)、情绪(20.09%)、多梦(10.16%)、噪音(8.86%)和气候(7.73%)等。睡眠状况与身心健康状况明显相关,相关系数7=0.937~0.980,P<0.01;睡眠指数对身心健康状况各指标均有明显影响(P<0.01),睡眠时间主要影响体能指数、健康指数、工作质量指数、工作积极性指数、注意力指数及情绪指数等(P<0.05~0.01),对食欲指数、记忆力指数影响则不明显。结论 在岛礁期间,影响作业人员睡眠的主要因素是值勤和情绪,睡眠状况明显影响身心健康状况。 相似文献
108.
目的 探讨血清瘦素在男生青春期发育中的作用。方法 健康男生170名,调查首次遗精时间,测定血清瘦素、睾酮、促卵泡成熟激素、黄体生成激素水平,采用多元Logistic回归模型分析男生青春期发育的影响因素;同时,连续两年观察,分析血清瘦素在青春期的动态变化。结果 末次研究已遗精组血清瘦素、睾酮、促卵泡成熟激素、黄体生成激素水平均明显高于未遗精组。多因素分析显示血清瘦素、睾酮、促卵泡成熟激素、体重为男生青春期发育的独立影响因素。初次资料分析,遗精前组血清瘦素、睾酮明显高于未遗精组。结论 血清瘦素、睾酮、促卵泡成熟激素、体重为男生青春期发育的独立影响因素,男生遗精前期血清瘦素、睾酮已有明显改变。 相似文献
109.
Implicit memory is independent from IQ and age but not from etiology: evidence from Down and Williams syndromes 总被引:1,自引:0,他引:1
S. Vicari L. Verucci & G. A. Carlesimo 《Journal of intellectual disability research : JIDR》2007,51(12):932-941
Background In the last few years, experimental data have been reported on differences in implicit memory processes of genetically distinct groups of individuals with Intellectual Disability (ID). These evidences are relevant for the more general debate on supposed asynchrony of cognitive maturation in children with abnormal brain development. This study, comparing implicit memory processes in individuals with Williams syndrome (WS) and Down syndrome (DS), was planned to verify the ‘etiological specificity’ hypotheses pertaining to the skill learning abilities of individuals with ID. Method A modified version of Nissen and Bullemer's (1987) Serial Reaction Time (SRT) task was used. The performances of three group were evaluated. The first group consisted of thirty‐two people with WS (18 males and 14 females). The second group was comprised of twenty‐six individuals with DS (14 males and 12 females). The two groups of individuals with ID were selected so that the groups were comparable as for mental age and chronological age. The third group consisted of forty‐nine typically developed children with a mental age similar to that of the groups with WS and DS. Results The two groups of individuals with ID demonstrated different patterns of procedural learning. WS individuals revealed poor implicit learning of the temporal sequence of events characterizing the ordered blocks in the SRT task. Indeed, differently from normal controls, WS participants showed no reaction time (RT) speeding through ordered blocks. Most importantly, the rebound effect, which so dramatically affected normal children's RTs passing from the last ordered to the last block, had only a marginal influence on WS children's RTs. Differently from the WS group, the rate of procedural learning of the participants with DS was comparable to that of their controls. Indeed, DS and typically developed individuals showed parallel RT variations in the series of ordered blocks and, more importantly, passing from the last ordered to the last block. Therefore, a substantial preservation of skill learning abilities in this genetic syndrome is confirmed. Conclusions The results of the present study document that procedural learning in individuals with ID depends on the aetiology of the syndrome, thus supporting the etiological specificity account of their cognitive development. These results are relevant for our knowledge about the qualitative aspects and the underlying neurobiological substrate of the anomalous cognitive development in mentally retarded people. 相似文献
110.
高性能战斗机改装体检飞行员的耳功能分析 总被引:6,自引:3,他引:3
目的 分析高性能战斗机改装体检飞行员的咽鼓管功能、前庭功能和听功能状况。方法 对改装体检的196名飞行员的耳功能资料进行分析。结果 ①声导抗示196例392耳中193例368耳为A型曲线,6例7耳为AD型曲线,15例17耳为C型曲线。196例392耳均无声反射衰减;②眼震电图示196例前庭功能均正常:③纯音测听以气导在500、1000、2000、3000Hz的平均听阈表示,196例的结果为左耳12.58dB HL;右耳12.48dB HL,但37例47耳有高频区噪声性听损伤的表现。结论 参与高性能战斗机改装体检的飞行员,其耳功能状况总体良好,但部分有噪声性听损伤的应随访观察。 相似文献