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1.
目的 对新疆地区蒙古族青年进行体质发育状况的研究,为营养学、医学、人类学提供基础研究资料。方法 采用邵象清的《人体测量手册》方法,对其身高、体重、胸围三项体质发育指标进行测量分析。结果 根据调查资料,分别统计 三项体质发育指标的均值及标准差、六项体质发育指数的均值及标准差。结论 新疆蒙古族青年身长较高,发育程度中等,体型属中间型,胸廓类型属中胸型。  相似文献   

2.
A great deal of research has been published on the development of the human temporomandibularjoint (TMJ). However, there is some discordance about its morphological timing. The most controversial aspects concern the moment of the initial organization of the condyle and the squamous part of the temporal bone, the articular disc and capsule and also the cavitation and onset of condylar chondrogenesis. Serial sections of 70 human specimens between weeks 7 and 17 of development were studied by optical microscopy (25 embryos and 45 fetuses). All specimens were obtained from collections of the Institute of Embryology of the Complutense University of Madrid and the Department of Morphological Sciences of the University of Granada. Three phases in the development of the TMJ were identified. The first is the blastematic stage (weeks 7-8 of development), which corresponds with the onset of the organization of the condyle and the articular disc and capsule. During week 8 intramembranous ossification of the temporal squamous bone begins. The second stage is the cavitation stage (weeks 9-11 of development), corresponding to the initial formation of the inferior joint cavity (week 9) and the start condylar chondrogenesis. Week 11 marks the initiation of organization of the superior joint cavity. And the third stage is the maturation stage (after week 12 of development). This work establishes three phases in TMJ development: 1) the blastematic stage (weeks 7-8 of development); 2) the cavitation stage (weeks 9-11 of development); and 3) the maturation stage (after week 12 of development). This study identifies the critical period of TMJ morphogenesis as occurring between weeks 7 and 11 of development.  相似文献   

3.
A great deal of research has been published on the development of the human temporomandibular joint (TMJ). However, there is some discordance about its morphological timing. The most controversial aspects concern the moment of the initial organization of the condyle and the squamous part of the temporal bone, the articular disc and capsule and also the cavitation and onset of condylar chondrogenesis. Serial sections of 70 human specimens between weeks 7 and 17 of development were studied by optical microscopy (25 embryos and 45 fetuses). All specimens were obtained from collections of the Institute of Embryology of the Complutense University of Madrid and the Department of Morphological Sciences of the University of Granada. Three phases in the development of the TMJ were identified. The first is the blastematic stage (weeks 7–8 of development), which corresponds with the onset of the organization of the condyle and the articular disc and capsule. During week 8 intramembranous ossification of the temporal squamous bone begins. The second stage is the cavitation stage (weeks 9–11 of development), corresponding to the initial formation of the inferior joint cavity (week 9) and the start condylar chondrogenesis. Week 11 marks the initiation of organization of the superior joint cavity. And the third stage is the maturation stage (after week 12 of development). This work establishes three phases in TMJ development: 1) the blastematic stage (weeks 7–8 of development); 2) the cavitation stage (weeks 9–11 of development); and 3) the maturation stage (after week 12 of development). This study identifies the critical period of TMJ morphogenesis as occurring between weeks 7 and 11 of development. Anat Rec 255:20–33, 1999. © 1999 Wiley‐Liss, Inc.  相似文献   

4.
Compared with birds and mammals, very little is known about the development and regulation of respiratory rhythm generation in ectothermic vertebrates. The development and regulation of respiratory rhythm generation in ectothermic vertebrates (fish, amphibians and reptiles) should provide insight into the evolution of these mechanisms. One useful model for examining the development of respiratory rhythm generation in ectothermic vertebrates has emerged from studies with the North American bullfrog (Rana catesbeiana). A major advantage of bullfrogs as a comparative model for respiratory rhythm generation is that respiratory output may be measured at all stages of development, both in vivo and in vitro. An emerging view of recent studies in developing bullfrogs is that many of the mechanisms of respiratory rhythm generation are very similar to those seen in birds and mammals. The overall conclusion from these studies is that respiratory rhythm generation during development may be highly conserved during evolution. The development of respiratory rhythm generation in mammals may, therefore, reflect the antecedent mechanisms seen in ectothermic vertebrates. The main focus of this brief review is to discuss recent data on the development of respiratory rhythm generation in ectothermic vertebrates, with particular emphasis on the North American bullfrog (R. catesbeiana) as a model.  相似文献   

5.
The role of the invariant chain (Ii), an MHC class II-associated chaperone, in B cell development is controversial. Ii deficient mice (Ii(-/-) mice) show a defect in B cell development.This defect has been attributed to the absence of a fragment liberated from the Ii by intramembranous proteolysis. It was proposed that this fragment is required for activation of the NF-kappaB pathway as a means of controlling B cell maturation. The opposing view holds that defects in the assembly of MHC class II molecules result in impaired B cell development. Here we demonstrate that a lack of Ii indeed causes defects in B cell development, with fewer mature B cells in the periphery as previously reported, but that in a compound-mutant from which both Ii and all MHC class II subunits are absent, B cell development is normal. We suggest that neither Ii itself, nor the MHC class II products are required for normal B cell development.  相似文献   

6.
Alcohol is much more slowly eliminated in the fetus than in the mother (< 50%). The ethanol and its derivative the acetaldehyde have a constant dose-effect on the development of the nervous system central. The individual susceptibility to alchol teratogenic effect in utero is responsible of variable clinical phenotype. This teratogenicity is constant during all the development of the central nervous system. The diagnosis of fetal alcohol syndrome (FAS) associates three criteria: delay of pre- and postnatal growth, abnormal development of the central nervous system, craniofacial abnormalities. Cerebral malformations are extremely variable, being to relate to the various stages of development of the nervous system central. Neurochimic abnormalities interest mainly the mono-aminergic system. The backwardness is the best known consequence of SAF (34 to 851%). It is not constant. Facial dysmorphic results of joint abnormalities whose none is pathognomonic but whose grouping is evocative. Psychomotor instability is the most frequent expression on the behavioral phenotype.  相似文献   

7.
8.
目的:考察曾留守大学生积极心理品质发展的特点。方法:采用曾留守大学生积极心理品质评定量表,对381名曾留守大学生进行调查。结果:(1)曾留守大学生积极心理品质总体得分高于平均水平(t=5.25,P0.01),其中正义与合作、乐观与期望维度得分显著高于平均水平(t=8.13,5.28;P0.01);(2)存在显著的性别差异,女生积极心理品质水平显著高于男生(t=11.72,P0.01);(3)非独生子女积极心理品质得分显著高于独生子女(t=9.81,P0.001);(4)各年级水平上,积极心理总体得分差异显著(F=68.56,P0.01),各维度表现出年级差异性,大二阶段可能为积极心理品质的发展转折期。结论:曾留守大学生积极心理品质总体发展良好;女生发展优于男生;非独生子女发展优于独生子女;各年级呈先升后降趋势,大二为发展转折期。  相似文献   

9.
The detailed mechanisms driving the development of natural killer (NK) cells from hematopoietic stem cells remain to be clearly elucidated. Here, we show that osteopontin (OPN) is a key factor for NK development. OPN-deficient mice evidenced severe impairments of NK development in bone marrow (BM) and spleen in which the NK populations that express CD122 and NK cell receptors were reduced. However, the absence of intrinsic OPN expression did not affect NK development, whereas the absence of OPN in the microenvironment caused a significant reduction in NK population. The expression of OPN was induced by interleukin (IL)-15 in BM stromal cells, and the defect in NK differentiation in IL-15(-/-) hematopoietic precursor cells (HPC) was recovered by addition of recombinant OPN, suggesting that the microenvironmental OPN may be a key factor in IL-15-mediated NK differentiation. In addition, OPN-driven NK maturation was reduced in T-bet-deficient HPC, suggesting that T-bet is required for OPN-mediated NK development. Collectively, these results show that paracrine OPN signaling drives NK-lineage commitment, thus ultimately promoting NK cell development. Disclosure of potential conflicts of interest is found at the end of this article.  相似文献   

10.
In recent years, there has been much discussion concerning the cervical fasciae. The aim of this study is to confirm and to describe the development of the alar fascia as well as its relationship with nearby structures. Histological preparations of 25 human embryos (6–8 weeks of development) and 25 human fetuses (9–12 weeks of development) were studied bilaterally using a conventional optical microscope. Our study confirms the existence of the alar fascia and permits three stages to be established during its development. The initial stage (1st), corresponding to the 6th week of development (Carnegie stages 18–19), is characterized by the beginning of the alar fascia primordium in the retroesophageal space at the level of C7‐T1. In the formation stage (2nd), corresponding to the 7th and 8th weeks of development (Carnegie stages 20–23), the alar fascia primordium grows upwards and reaches the level of C2–C3. In the maturation stage (3rd), beginning in the 9th week of development, the visceral, alar and prevertebral fasciae can be identified. The alar fascia divides the retrovisceral space (retropharyngeal and retroesophageal) into two spaces: one anterior (between the alar fascia and the visceral fascia and extending from C1 to T1, named retropharyngeal or retroesophageal space according to the level) and the other posterior (between the alar fascia and the prevertebral fascia, named danger space). We suggest that this latter space be named the retroalar space. This study suggests that alar fascia development is related to mechanical factors and that the alar fascia permits the sliding of the pharynx and the oesophagus during swallowing.  相似文献   

11.
A habronemid nematode in birds of prey, Milvus migrans Bonaparti and Accipiter badius Linné, in Togo, is identified as Cyrnea (Procyrnea) mansioni (Seurat, 1914). Larval development is experimentally studied in the orthopteran Acrididae Tylotropidius patagiatus Karsch. The first three larval stages are described and illustrated. The biology of this spiruroid nematode is distinguished by the unusual rapidity of larval development (infective larvae at 10 days). Comparison of the life cycle of C. mansioni with life cycles of other Habronemid Nematodes parasitizing birds, points out an evolution of larvae from primitive forms of large size and slow development to evolved forms of small size and rapid development. Observations concerning the encapsulation of infective larvae in the intermediate host confirm this larval evolution.  相似文献   

12.
小鼠耳蜗发育的形态学研究   总被引:6,自引:0,他引:6  
目的:探讨小鼠耳蜗发育的特点及规律。方法:应用光镜对昆明种小白鼠耳蜗从胚胎第10天至出生后第14天的整个发育过程进行形态学研究。结果:小鼠耳蜗的整个形态发育过程可分为三个时期:⑴听泡发育期;⑵蜗管上皮增殖期;⑶耳蜗各部分结构的分化结构的分化期和发育成熟期。结论:小鼠在出生时,其耳蜗膜迷路的大部分结构成份已经形成,出生后则需进一步的分化发育,至出生后2周时才完全发育成熟。小鼠耳蜗管上皮的分化是从底周  相似文献   

13.
Stimulation of murine CD4+ T cells with staphylococcal enterotoxin B (SEB) results in the preferential development of T helper (Th) 1 cells [i.e. high interferon (IFN)-γ and low interleukin (IL)-4, IL-5 and IL-10]; whereas in response to plate-bound anti-CD3 or anti-T cell receptor-αβ, Th1 as well as Th2 cells develop. In the present study, we examined the mechanism which is responsible for the selective Th1 development in the SEB system. The addition of IL-4 resulted in a strong development of Th2 cells showing that SEB stimulation can result inTh2 differentiation. Co-stimulation with anti-CD28 was insufficient in this regard. Lack of Th2 development in the SEB system was in part due to the inhibitory effect of endogenously produced transforming growth factor-β (TGF-β), because anti-TGF-β allowed the development of Th2 cells. Similarly, TGF-β inhibited Th2 development and stimulated Th1 development in the anti-CD3 system. This shift was only partially prevented by also including IL-4 in the cultures. The effects of TGF-β could only partially be explained by stimulation of IFN-γ or inhibition of IL-4 as intermediatory cytokines: (1) TGF-β stimulated Th1 development even in the presence of anti-IL-4 and anti-IFN-γ, and (2) a strong inhibitory effect of anti-TGF-β on Th1 development was still observed when anti-IL-4 and IFN-γ were simultaneously added to the cultures. It is concluded that SEB favors Th1 development by stimulation of TGF-β production. Inhibition of Th2 development by TGF-β is due, in part, to inhibition of IL-4 and stimulation of IFN-γ, and, in part, to a direct effect of TGF-β on the responding T cells.  相似文献   

14.
The adrenal cortex and pancreatic islets have endocrine functions, producing steroid-based hormones and insulin, respectively. Cells of the adrenal cortex originate in the mesoderm while the cells of pancreatic islets originate in the endoderm. The zebrafish is a powerful model for understanding organ development due to its ease of genetic and molecular manipulation, transparent embryos, and large number of progeny for statistically powerful experiments. Like humans, the zebrafish pancreas has both exocrine and endocrine functions; unlike humans, there is only one endocrine islet cell group, instead of multiple islets. Using an eGFP-transgenic line of zebrafish, we have observed that the steroidogenic factor 1 (SF1) ortholog, ff1b, which is critical for adrenal cortex development and function in the zebrafish, is also implicated in zebrafish pancreatic islet development. We show that interruption of ff1b expression using an ff1b-morpholino (MO) disrupts development of insulin expressing cells. We conclude that ff1b-MO alters pancreatic islet development in zebrafish, demonstrating the utility of the zebrafish as a model for studying pancreatic development. This work is consistent with previous studies in mouse and human that have suggested SF1 participates in the vascular and ductal development of the pancreas, and disruption of SF1 function leads to abnormal development of the pancreatic islets due to poor vascularization.  相似文献   

15.
The association between physical growth and gross motor development, particularly self-produced locomotion, was considered in 557 children 3–18 months of age. Gross motor development was assessed with nine preselected milestones representing the major landmarks in self-produced bipedal locomotion. Motor development is presented by age and by milestone, and is compared to developmental ranges of the Denver Developmental Screening Test. Consistent with other studies of undernutrition and motor development, length-for-age, but not weight-for-length, was a significant predictor of gross motor development (i.e., delayed or not delayed). The effect of weight-for-age on motor development was not statistically significant after accounting for length-for-age. © 1994 Wiley-Liss, Inc.  相似文献   

16.
The object of this study was to investigate whether there is an association between HLA-DRB1 alleles and the development of juvenile idiopathic arthritis (JIA) in Taiwan. HLA-DRB1 alleles were studied in 60 patients with JIA and 200 healthy controls using polymerase chain reaction (PCR)/sequence-specific oligonucleotide probes (SSO). The frequency of HLA-DRB1*0405 in patients with JIA was found to be significantly higher than that in healthy controls [odds ratio (OR) 2.64, 95% confidence interval (CI) 1.01-6.91]. The DRB1*0405 allele was significantly associated with the development of both polyarthritis (OR 4.30, 95% CI 1.34-13.80) and oligoarthritis (OR 3.27, 95% CI 1.01-10.58). The frequency of HLA-DRB1*1502 was higher in Taiwanese JIA patients with systemic arthritis than in controls (OR 18.09, 95% CI 2.25-145.73). We conclude that, in Taiwan, HLA-DRB1*0405 is associated with the development of polyarthritis and oligoarthritis in children, and HLA-DRB1*1502 is associated with the development of systemic arthritis.  相似文献   

17.
The co-actions of genetic effects and the post-natal maternal rearing environment on the development of weight, 9 reflex responses, and survival have been tested by the cross-fostering method in two inbred mice strains-CBA/H and NZB. Pups of the two strains were not treated differentially by the mothers and experimental handling did not systematically affect pup development. Comparisons of unfostered, infostered, and cross-fostered pups show (1) in 16 cases out of 34, reflex development was affected by the pup strain, and in 10 cases out of 34 by the foster mother strain; (2) survival is only affected by the pup strain; (3) weight development is affected by strain of both the pup and the mother as well as their interactions. The adopted pups' scores were situated outside the range of the two non-adopted groups for certain reflexes as well as for weight. Two non-exclusive hypotheses are proposed: the mother strain can affect pup development (1) either through differences in stimulation provided by the mothers (2) or through differences in milk composition.  相似文献   

18.
Histological and ultrastructural analysis of the development of C. roussilhoni--a filarial parasite of A. africanus with skin-dwelling microfilariae--in the hexapod, larva of R. sanguineus. The development takes place in the epidermis. The intra-epidermal development, which is rare in the Spirurida, is known in a close filaria, also transmitted by Ixodids, Monanema martini. The slow development of C. roussilhoni and the pronounced changes of the parasitized epidermal syncytium (very large nuclei; expanding nuclear envelop and cellular membrane which form complicated expansions; many dilatations of the endoplasmic reticulum) demonstrate the more primitive state of this filaria.  相似文献   

19.
20.
2003年世界性的流行病——严重急性呼吸综合症(SAILS)引发了各国科学家对SARS相关冠状病毒(SARS-Coy)的研究热潮。SARS-Coy是一种新的冠状病毒,其致病机制还不清楚,目前尚无有效治疗SARS的抗病毒药物,研制一种安全有效的疫苗是阻止SARS再次流行最有效的方式。目前研究较多且有发展前景的SARS疫苗有:灭活疫苗、DNA疫苗和表位疫苗等。但在SARS疫苗的研究过程中也遇到了很多问题,如没有标准的动物模型、SARS-Coy变异快等问题。所以,研发一种安全有效的SARS疫苗任重而道远。  相似文献   

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