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61.
In primates, corpus luteum development involves both gonadotrophin stimulation and exposure to low density lipoprotein (LDL) delivered through vascularization of the granulosa cell-derived layer. These regulatory influences were modelled in vitro using granulosa cells obtained during in-vitro fertilization (IVF) cycles controlled with gonadotrophin releasing hormone (GnRH) analogue, human menopausal gonadotrophin (HMG) and human chorionic gonadotrophin (HCG). Granulosa cells were cultured in defined medium on extracellular matrix. Without gonadotrophin or LDL in the medium, progesterone production declined progressively. With LDL alone, there was a short-lived elevation of progesterone output which subsequently declined. Culture with HCG alone resulted in a relatively unchanged rate of steroid production over 5 days despite morphological development. This contrasted with a marked and sustained increase in progesterone output over the same time when granulosa cells were cultured with combined HCG/LDL. Cultures were challenged with combined HCG/LDL on day 5. Where initial incubation included HCG, the challenge resulted in a recovery of progesterone output to values comparable to those of granulosa cells exposed to continuous HCG/LDL. Initial incubation without gonadotrophin led to a reduced response. Results suggest that LDL delivery to granulosa cells of the early corpus luteum causes a short-lived period of progesterone production. Sustained luteinization of granulosa cells and maintenance of gonadotrophin responsiveness requires continued exposure to gonadotrophin in the luteal phase.  相似文献   
62.
Our group has previously reported significant changes in the incorporation of precursors into glycerophospholipids, particularly phosphatidylserine, in polymorphonuclear cells obtained from the peripheral blood of cluster headache patients, when compared with controls. The potential of these results led to further work using both the previous methodology and a modified isolation technique to obtain polymorphonuclear cells in as pure a state as possible. Neither the new results obtained using the original technique, nor the results with high purity polymorphonuclear cells from controls and cluster headache patients, confirm the marked changes in precursor uptake into glycerophospholipids originally reported.  相似文献   
63.
Objective: To study the calcium channel reaction of human Leydig cells induced by hCG/ATP at different extracellular calcium ion concentrations. Methods: The Leydig cell calcium ion concentration was examined with laser confocal microscope, when the cells were stimulated with hCG/ATP at different extracellular calcium contrations. Results: With calcium-containing extracellular fluid, the Leydig cells were sensitive to hCG stimulation and when the extracellular fluid was calcium-free, the Leydig cells did not respond to the stimulation. However, the Leydig cells did respond to ATP stimulation no matter the extracellular fluid contained calcium or not. Conclusion: In human Leydig cells, there are calcium channels sensitive to hCG and ATP. The extracellular calcium ion concentration plays an important role in the regulation of Leydig cell metabolism by hCG/ATP.  相似文献   
64.
BACKGROUND: Nitric oxide (NO) plays a key role in wound repair and S-nitrosothiols like S-nitrosoglutathione (GSNO) are well known NO donors. METHODS: Animals were separated in two groups and submitted to excisional wounds on the dorsal surface at the first day. GSNO (100 microm)-containing hydrogels were topically applied on the wound bed in the GSNO group, daily, during the first 4 days. Control group was topically treated with hydrogel without GSNO for the same period. Wound contraction and re-epithelialization were measured. Animals were sacrificed 21 days after wounding. Samples of lesion and normal tissue were formalin-fixed, paraffin embedded for histological analysis. RESULTS: Wound contraction, measured 14 and 21 days after wounding, was greater in the GSNO group than in the control group (P<0.05 for both). The re-epithelialized wound area, measured 14 days after wounding, was higher in the GSNO group than in the control group (P<0.05). A higher amount of inflammatory cells was observed in superficial and deep areas of the granulation tissue of the control group compared to the GSNO group. Twenty-one days after wounding, thin red-yellow collagen fibers arranged perpendicularly to the surface were found in the granulation tissue of the control group, whereas in the GSNO-treated group collagen fibers were thicker and arranged parallel to the surface. Increased number of mast cells was observed in the GSNO group compared with that in the control group. Vascularization and myofibroblast distribution were similar in both groups. CONCLUSION: Topical application of GSNO-containing hydrogel during the early phases of rat cutaneous wound repair accelerates wound closure and re-epithelialization and affects granulation tissue organization.  相似文献   
65.
Summary After orthotopic rat liver transplantation in the fully allogeneic BN (RT-1n) to LEW (RT-11) combination, the phenomenon of spontaneous tolerance of donor antigen occurs. We demonstrate two different immune mechanisms that may account for this process. Using adoptive transfer assays we show the presence of donor-specific T-suppressor lymphocytes in the spleens of long-term surviving liver graft, recipients. These cells prolong - adoptively transferred into irradiated syngeneic hosts — the survival of donor-specific (BN) but not third-party (DA) renal allografts (I00 days vs 1I days in control groups). Secondly, we demonstrate the replacement of Kupffer cells in the graft by recipient macrophages using polymorphic monoclonal antibodies in an immunoperoxidase technique. This may contribute to graft adaptation and thus to long-term graft acceptance.  相似文献   
66.
The clinical signs and neuropathological changes are described in six Limousin X calves that, at about one month after birth, showed signs of blindness, nystagmus, rotation of the eyes, opisthotonos, hyperprotraction of the forelegs and, in one case, apparent seizures. Pathologically there was necrosis of the optic chiasma and focal areas of myelin sheath vacuolation or demyelination in certain areas of the brain, especially in the cerebellar peduncles. In one animal, kept alive for 7 months, there was remyelination by Schwann cells of some demyelinated axons in the focal cerebellar lesions, while other axons remained demyelinated. There was no evidence of oligodendrocyte remyelination. The cause of the condition was not determined but a genetic association is likely.  相似文献   
67.
Peripheral blood stem cell autografting   总被引:1,自引:0,他引:1  
Transplantation of haemopoietic stem cells provides a means whereby patients with malignant disease may be treated with increased doses of chemotherapy or chemoradiotherapy. Until recently, the bone marrow has been the sole source of these cells. However, haemopoietic progenitors can also be demonstrated in the blood and it has been known for more than twenty years that peripheral blood mononuclear cells are capable of repopulating the marrow in animals. This phenomenon has recently been reproduced in man. The use of peripheral blood rather than bone marrow for autologous stem cell rescue may have advantages in terms of ready access, availability in patients with compromised pelvic bone marrows, a lower risk of tumour contamination and more rapid granulocyte and immune recovery. However, clinical experience with peripheral blood stem cell autografting is still very small. This review discusses the characteristics of circulating stem cells, the methods by which they can be collected and stored and the information which has come from recent studies of their transplantation in man.  相似文献   
68.
69.
目的:观察体外循环(CPB)对10例瓣膜置换术病人全血细胞胰岛素受体和红细胞ATP含量的影响。方法:利用放射配体结合试验,测定全血细胞胰岛素受体密度和亲和力;用高效液相色谱法测定红细胞ATP含量,同时监测血糖和胰岛素浓度。结果:转流30分钟,血细胞高亲和胰岛素受体(R1)密度明显增加(P<0.01),亲和力(K1)明显降低(P<0.01),低亲和胰岛素受体(R2)密度也明显增加(P<0.01),但亲和力(K2)变化不大(P>0.05);停机30分钟,上述变化有所恢复,但未到转流前的水平。转流30分钟红细胞ATP含量明显降低(P<0.01),并持续到停机后30分钟,同时伴随血糖明显升高(P<0.01),胰岛素/血糖比值明显降低(P<0.01)。结论:CPB可致血细胞胰岛素受体密度增加而亲和力下降,以及红细胞ATP含量下降。  相似文献   
70.
We reported a new monoclonal antibody, designated FUB-1, reacting with normal and neoplastic large lymphoid cells. FUB-1 was produced using a Burkitt's lymphoma cell line (HBL-5) as an immunogen. Its immunoglobulin subtype was IgM. The determinant was not on the surface but in the cytoplasm. Western blotting analysis revealed that the molecular weight of the antigen was 52,000 dalton. In the normal lymphoid tissue, FUB-1 reacted with large lymphoid cells, but not with small or medium-sized lymphoid cells or plasma cells. In addition, the FUB-1 antigen was not found in resting cells in the peripheral blood (PB), but it was induced on mononuclear cells of PB by addition of PWM or PMA. In the B-cell lymphomas tested, FUB-1 reacted with small cleaved cell lymphomas (3/12), large cell lymphomas (7/10), Burkitt's lymphomas (4/4) and immunoblastic lymphomas (2/2), but not with small cell lymphomas (0/3) or intermediate lymphocytic lymphomas (0/8). These findings indicate that the FUB-1 antigen appears to be expressed on normal lymphoid cells during blastoid transformation and on neoplastic large lymphoid cells. FUB-1 also reacted with normal glandular epithelium and various adenocarcinomas. FUB-1 may be useful to investigate the mechanism of in vitro blastoid transformation or activation of lymphoid cells.  相似文献   
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