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1.
Follicular development in the bursa of Fabricius was disrupted by testosterone treatment and chorioallantoic membrane grafting. Analysis by a quantitative histological technique demonstrated that testosterone treatment causes a dose dependent delay in development by inhibiting lymphoid proliferation. Inhibition of lymphoid development prevented the development of carbon transport ability by follicle associated epithelium. Reconstitution of follicular development by grafting treated bursae to the chorioallantoic membrane of untreated hosts results in the development of functional follicle associated epithelium. These results establish the lymphoid requirement for the development of transport ability by the follicle-associated epithelium.  相似文献   

2.
There are elementary and complex types (combined elementary types): of temporospatial relations between the pattern of development of the organism and the patterns of development of individual subsystems; of influences exercised by the development of the organism upon the development of the subsystems of the organism; of influences exercised by the development of individual subsystems upon individual development; of temporospatial relations between the stability of the line of individual development and the stability of the line of development of individual subsystems; of mutual influence between the stability and variation of the line of individual development, on the one hand, and the stability and variation of the line of development of the individual subsystems, on the other.  相似文献   

3.
Stimulation and inhibition of gonadal development by intersexual contact was studied in pubertal African catfish, Clarias gariepinus. The effect of a possible interaction was studied by evaluation after a 98-day experimental period of gonadal development in combinations of intact and anosmic males and females. In addition, separate groups of males and females, respectively, were exposed to holding water from these combinations. A tentative model of stimulation of gonadal development by intersexual contact in pubertal fish was developed. Males stimulate ovarian development of females by both olfactory and tactile cues. In addition, males seem to enhance gonadal development of other males through olfactory stimulation via holding water. In contrast, females tended to inhibit male gonadal development, especially through tactile cues. It seems that although males are hampered by female tactile stimuli in their gonadal development and ability to stimulate male gonadal development, their ability to stimulate female gonadal development is not affected.  相似文献   

4.
M-CSF is a key cytokine in macrophage development by inducing MAPKs activation, and cAMP can inhibit MAPKs activation induced by inflammatory stimuli. To explore the effects of cAMP on M-CSF-induced MAPKs activation and on macrophage development, the model of bone marrow-derived murine macrophages (BMMs) was used. The effects of cAMP on M-CSF-induced MAPKs activation were analyzed by Western blotting assay, and the effects of cAMP on CD14 and F4/80 expression during macrophage development were examined by FACS analysis. Macrophage morphology showed the successful establishment of the model of macrophage development. Western blotting assay revealed that M-CSF activated ERK, JNK and p38 in both mature and immature macrophages, and cAMP inhibited M-CSF-induced ERK, JNK and p38 activation in a time-dependent manner. FACS analysis revealed that macrophage development was impaired with cAMP pretreatment. In conclusion, cAMP modulates macrophage development by suppressing M-CSF-induced MAPKs activation. Cellular & Molecular Immunology.  相似文献   

5.
6.
We investigated the development of exoerythrocytic forms (EEF) of Plasmodium berghei in livers of normal and macrophage-depleted Brown Norway rats. Macrophages were depleted by use of liposome-encapsulated dichloromethylene diphosphonate. Upon inoculation of sporozoites, macrophage-depleted rats had significantly larger numbers of EEF than untreated rats. We also investigated the effect of macrophage impairment by silica treatment on the development of EEF and confirmed that silica induces a significant reduction of EEF development. Intravenous administration of silica induced high levels of interleukin-6 in plasma within a few hours. The seemingly contradictory results for EEF development may be explained by our previous observation that interleukin-6 strongly inhibits sporozoite penetration and EEF development in vivo. We conclude that in experimental infections with sporozoites, Kupffer cells inhibit rather than enhance EEF development.  相似文献   

7.
细胞因子与肝纤维化   总被引:4,自引:0,他引:4  
戴敏  郭顺根 《解剖科学进展》2003,9(4):365-370,374
影响肝纤维化发生、发展进程的细胞因子主要可分为促肝纤维化细胞因子和抗肝纤维化细胞因子两大类 ,这些细胞因子构成复杂的调节网络 ,通过多种信号转导途径传递信号 ,调控肝纤维化的发生发展。本文对多种细胞因子在肝纤维化发生、发展过程中的作用加以综述。  相似文献   

8.
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   

9.
免疫缺陷主要由免疫细胞发育、分化和功能异常导致。已有研究表明,表观遗传调控对于免疫细胞的正常发育具有重要作用。该研究发现组蛋白甲基转移酶NSD2对于B细胞的发育起着重要的调控作用,并且利用转录组测序找到了调节B细胞发育的重要通路。该研究为免疫缺陷病的治疗提供了新的治疗靶点。  相似文献   

10.
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   

11.
Previous studies have shown that spinal cord development in direct developing frogs of the genus Eleutherodactylus, which have evolutionarily lost the tadpole stage, differs from that in biphasically developing anurans (with the larval and the adult stage separated by metamorphosis). The present study of spinal cord development in Eleutherodactylus coqui provides additional information about neurogenesis, neuronal differentiation and growth analyzed by immunostaining for proliferating cell nuclear antigen (PCNA), in situ hybridization for NeuroD, and morphometric measurements in various developmental stages. Furthermore, spinal cord development in the frogs Discoglossus pictus, Xenopus laevis, and Physalaemus pustulosus, which belong to different anuran families but all exhibit biphasic development, was similarly analyzed. This comparative analysis allows inference of the ancestral anuran pattern of spinal cord development and how it has been modified during the evolution of Eleutherodactylus. All biphasically developing frogs analyzed share a similar pattern of spinal cord development, suggesting that this is ancestral for anurans: after neural tube closure, levels of proliferation and neurogenesis in the spinal cord were low throughout embryogenesis until they were upregulated drastically at early larval stages followed by development of the lateral motor columns. In contrast, no such quiescent embryonic period exists in E. coqui, where rapid growth, high levels of proliferation and neurogenesis, and early formation of lateral motor columns occur shortly after neural tube closure, while other parts of the central nervous system develop more slowly. Thus, spinal cord development has been accelerated during the evolution of Eleutherodactylus relative to the development of other parts of the central nervous system, probably related to the precocious development of limbs in this lineage.  相似文献   

12.
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   

13.
14.
背景:促红细胞生成素是低氧诱导因子1的下游靶基因,受低氧诱导因子1的调节。 目的:观察大鼠视网膜胚胎期及出生后早期发育过程中促红细胞生成素的时空表达与视网膜发育的关系。 方法:取胚胎12,16,20 d鼠胚及成年Wistar大鼠各5只,处死后摘除眼球,分离视网膜,用免疫组织化学方法、半定量反转录聚合酶联反应检测视网膜促红细胞生成素蛋白及促红细胞生成素 mRNA的表达。 结果与结论:胚胎期大鼠视网膜神经上皮及色素上皮细胞的胞浆及胞核内均有促红细胞生成素阳性表达,表达趋势随胎龄增长而逐渐减弱;成年鼠视网膜促红细胞生成素阳性表达最弱。说明大鼠视网膜胚胎发育过程中促红细胞生成素的表达存在时空上的变化,这种变化可能与大鼠视网膜胚胎期的发育密切相关。  相似文献   

15.
目的 通过抑制sox19b基因的表达,探讨sox19b基因在斑马鱼胚胎眼睛发育和形成中的作用。方法 通过显微注射sox19b 吗啉寡聚核苷酸(MO)抑制sox19b 基因的表达,观察胚胎发育过程中表型的变化;采用石蜡包埋组织切片及HE染色、RT-PCR和整封原位杂交等方法探讨敲除sox19b 后对斑马鱼胚胎眼睛发育的调控机制。 结果 敲除sox19b 基因后,斑马鱼胚胎眼睛发育受到影响,表现为眼睛变小或缺失,视网膜及晶状体结构发育异常(n =57/93);眼睛发育过程中重要调控基因 rx3、pax2a及 vsx2 等表达明显降低,进而影响眼睛的发育和形成。 结论 sox19b 基因作为转录调控因子,可以通过调节眼区转录因子的表达进而影响斑马鱼胚胎早期眼睛的发育和形成。  相似文献   

16.
The synaptic development of organotypic cultures of cerebellum derived from new-born mice was examined by light and electron microscopy at 5, 8, 12 and 19 daysin vitro. These explants were then compared with cerebellar tissue from mice killed by perfusion at corresponding ages. The comparison suggests that there is an initial lag in synaptic development most clearly seen at 5 and 8 daysin vitro, followed by an accelerated development resulting in closein vivo andin vitro correspondence by day 19.The findings suggest that synaptic development of cerebellumin vitro followsin vivo development with fidelity despite substantial disruption of cell migration patterns, and further validates the use of organotypic cultures for physiological, biochemical, and pharmacological study.  相似文献   

17.
Gut-associated lymphoid tissue (GALT) development requires interaction with the intestinal microbiota. Because murine secondary lymphoid tissue development is driven by positive feedback interactions between B cells and stromal cells, we used in situ hybridization to determine whether intestinal commensals influence such interactions during rabbit appendix development. The features of positive feedback interactions we examined (CXCL13 mRNA expression, B cell accumulation and FDC differentiation) increased during early follicle development, but stalled in the absence of intestinal commensals. These features were reinitiated by commensals that stimulated follicle development and intrafollicular B cell proliferation. Our results suggest that rabbit appendix follicles develop in two phases: an initial phase of B cell recruitment to nascent follicles, possibly through positive feedback interactions, and a subsequent phase of intrafollicular B cell proliferation stimulated by intestinal commensals. In addition, we found that intestinal commensals stimulate appendix CCL21 mRNA expression and T cell area formation.  相似文献   

18.
19.
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   

20.
Rho family small GTPases are key regulators for neuronal morphogenesis including dendritogenesis. We recently have shown that Rnd1, a member of the Rho family, is highly expressed in brain during the synaptogenic stage and is involved in dendritic spine formation. However, the mechanism by which Rnd1 regulates dendritic development including spine morphogenesis remains unknown. Here we report that Rnd1, a member of the Rho family, plays a critical role in neuronal activity-dependent dendritic development in hippocampal neurons. Overexpression of Rnd1 promoted dendritic growth and branching in cultured hippocampal neurons. On the other hand, suppression of endogenous Rnd1 expression by RNA interference significantly inhibited neuronal activity-dependent dendritic development and this inhibitory effect was canceled by inhibition of RhoA effector ROCK. In addition, knockdown of Rnd1 also abolished dendritic development promoted by treatment with brain-derived neurotrophic factor in hippocampal neurons. Our findings demonstrate that Rnd1 is involved in signaling pathways of neuronal activity-dependent dendritic development.  相似文献   

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