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991.
Although insulin has been shown to raise plasma concentrations of endothelin (ET) and up regulate vascular smooth muscle ETA receptor expression, the interaction of vanadate, an insulinomimetic agent, with the vascular ET system has not been investigated. We compared the effects of oral vanadate treatment (0.5 mg/ml; p.o.) and insulin infusion (12 mU.kg-1.min-1 s.c.) for two weeks on plasma ET concentrations and vascular responses to endothelin-1 (ET-1) and the alpha-1 adrenoceptor agonist, methoxamine, in aortic ring preparations from streptozotocin (STZ) diabetic and non-diabetic adult male Sprague-Dawley rats. Plasma ET concentrations were lower (p < 0.01) in STZ diabetic rats compared with normal control rats. Insulin and vanadate treatment restored plasma ET to normal (p < 0.01) in STZ rats and increased ET concentrations in the control (p < 0.05) group. Higher maximal tension responses to both ET-1 (p < 0.01) and methoxamine (p < 0.05) were present in STZ rats in both endothelium intact and denuded aortic preparations compared with the control group. Both insulin and vanadate treatment returned these responses to normal. It is concluded that low plasma concentrations of insulin and high plasma glucose in STZ diabetic rats are accompanied by lower concentrations of plasma ET. Insulin and vanadate treatment restores diminished plasma ET to control concentrations and attenuates exaggerated agonist(s)-evoked vascular smooth muscle responses in STZ-induced diabetic rats. In addition to well known beneficial metabolic effects, insulin and vanadate may beneficially affect cardiovascular regulation in the STZ diabetic rat by correcting abnormal ET activity.  相似文献   
992.
The oral efficacy of chicken egg yolk immunoglobulins (yIg) specific for bovine rotavirus (BRV) serotypes G6 and G10 in protecting neonatal calves was examined in a herd of cattle under field conditions. In one of the three trials, yIg-treated calves tested under high relative humidity (RH) showed a significantly increased mean body weight (P < 0.05) and a decrease in number of calves shedding high titer of BRV (G6) in stool compared to control calves (P < 0.01), suggesting that our yIg product was effective in a field condition with an epidemic outbreak of BRV diarrhea.  相似文献   
993.
The production of extracellular beta-amylase by some Bacillus cereus, Bacillus megaterium and Bacillus polymyxa [corrected] strains was investigated, and the maximal yields of the enzyme were 3.6; 9.3 and 20.4 U/mL of the culture fluid, respectively (U, 1 mumol of maltose equivalent per min at 30 degrees C). Several cultivation media were used for beta-amylase production. Bacillus cereus and some strains of Bacillus megaterium gave good yields of beta-amylase only in medium with the addition of nutrient broth. However, beta-amylase produced during growth in protein rich medium (nutrient broth) was highly unstable, probably due to inactivation by proteolytic enzymes co-existing in the culture fluid. Bacillus polymyxa [corrected] strains can produce good yields of beta-amylase on a semi-synthetic medium consisting of inorganic salts, potato starch and inexpensive soybean extract instead of costly peptone and meat extract. The most potential beta-amylase producer was the strain Bacillus polymyxa [corrected] NCIB 8524. The tested Bacillus megaterium and Bacillus polymyxa [corrected] strains were apparently differentiated by temperature cultivation (30 and 37 degrees C) suitable for beta-amylase amylase yield.  相似文献   
994.
OBJECTIVE: Knee osteoarthritis (OA) is highly prevalent, especially in the elderly. Preventive strategies require a knowledge of risk factors that precede disease onset. The present study was conducted to determine the longitudinal risk factors for knee OA in an elderly population. METHODS: A longitudinal study of knee OA involving members of the Framingham Study cohort was performed. Weight-bearing knee radiographs were obtained in 1983-1985 (baseline) and again in 1992-1993. Incident disease was defined as the occurrence of new radiographic OA (Kellgren and Lawrence grade > or = 2 on a 0-4 scale) in those without radiographic OA at baseline. Risk factors assessed at baseline and in the interim were tested in univariate and multivariate equations to evaluate their association with incident knee OA. RESULTS: Of 598 patients without knee OA at baseline (mean age 70.5 years, 63.7% women), 93 (15.6%) developed OA. After adjustment for multiple risk factors, women had a higher risk of OA than did men (adjusted odds ratio [OR] = 1.8, 95% confidence interval [95% CI] 1.1-3.1). Higher baseline body mass index increased the risk of OA (OR = 1.6 per 5-unit increase, 95% CI 1.2-2.2), and weight change was directly correlated with the risk of OA (OR = 1.4 per 10-lb change in weight, 95% CI 1.1-1.8). Physical activity increased the risk of OA (for those in the highest quartile, OR = 3.3, 95% CI 1.4-7.5). Smokers had a lower risk than did nonsmokers (for those who smoked an average of > or = 10 cigarettes/day, OR = 0.4, 95% CI 0.2-0.8). Factors not associated with the risk of OA included chondrocalcinosis and a history of hand OA. Weight-related factors affected the risk of OA only in women. CONCLUSION: Elderly persons at high risk of developing radiographic knee OA included obese persons, nonsmokers, and those who were physically active. The direction of weight change correlated directly with the risk of developing OA.  相似文献   
995.
The pattern of suicide in Ireland broadly matches that in various neighbouring countries, with the prevalence among males being significantly greater than among women. Over recent years there has been a significant increase in suicide among young men. Similarly, prison suicide patterns mirror those in neighbouring jurisdictions, with a marked increase in prison suicides occurring over the last 10 years. Media interest in prison suicide is grossly disproportionate to its frequency. Existing prevention policies based on the identification of individuals at risk would appear to have failed, and it is argued that it would be more productive--albeit with significant difficulty--to re-orient prevention strategies towards identifying and remedying risk factors in the overall prison environment as opposed to identifying particular individuals.  相似文献   
996.
The relative contributions of T-lymphocyte subsets to host defense in cattle infected with Mycobacterium avium subsp. paratuberculosis is reported. The subsets were purified with appropriate monoclonal antibodies and a magnetic bead column separation system, and their purity was verified by flow cytometry. Biological activity of each subset, expressed as lymphoproliferation and gamma interferon (IFN-gamma) production, was measured in response to phytohemagglutinin (PHA) and an M. avium antigen preparation (A-PPD). IFN-gamma was measured by antibody capture enzyme-linked immunosorbent assay. The results showed a correlation between proliferation and IFN-gamma production in response to A-PPD but not to PHA. In response to PHA, CD4+ lymphocytes were the most prolific producers of IFN-gamma. CD8+ lymphocytes produced IFN-gamma to a lesser extent, whereas gammadelta+ T lymphocytes produced little or no IFN-gamma. Differences observed between the amount of IFN-gamma produced by CD4+ versus CD8+ cells and CD4+ versus gammadelta+ cells were significant (P < 0.01), but those between peripheral blood mononuclear cells (PBMC) and CD4+ T cells were not. Similar responses to A-PPD were observed except that PBMC produced higher levels of IFN-gamma than did CD4+ T cells. These data for cattle are similar to observations made for other animal species, where CD4+ cells are the major type of T lymphocytes producing IFN-gamma. They further suggest that whatever the role gammadelta+ T cells may play in paratuberculosis, it is not likely to be mediated by IFN-gamma production.  相似文献   
997.
BACKGROUND: Mixed hematopoietic chimerism induced with a nonmyeloablative conditioning regimen leads to donor-specific transplantation tolerance. Analyses of specific Vbeta-bearing T-cell families that recognize endogenous superantigens demonstrated that donor-specific tolerance is due mainly to an intrathymic deletional mechanism in these mixed chimeras. However, superantigens are not known to behave as classical transplantation antigens. We therefore used T-cell receptor (TCR) transgenic (Tg) recipients expressing a clonotypic TCR specific for an allogeneic major histocompatibility complex antigen to further assess deletional tolerance. METHODS: 2C TCR Tg mice (H2b), whose Tg TCR recognizes major histocompatibility complex class I Ld, were used as recipients of Ld+ bone marrow cells after conditioning with depleting anti-CD4 and CD8 monoclonal antibodies, 3 Gy whole-body irradiation, and 7 Gy thymic irradiation. Chimerism and deletion of CD8+ 2C recipient T cells was evaluated by flow cytometry and by immunohistochemical staining. Tolerance was tested with in vitro cell-mediated lympholysis assays and in vivo by grafting with donor skin. RESULTS: Intrathymic and peripheral deletion of 2C+ CD8-single-positive T cells was evident in mixed chimeras, and deletion correlated with the presence of donor-type cells with dendritic morphology in the thymus, and with chimerism in lymphohematopoietic tissues. Chimeras showed tolerance to the donor in cell-mediated lympholysis assays and specifically accepted donor skin grafts. CONCLUSIONS: Tolerance to transplantation antigens is achieved through intrathymic deletion of donor-reactive T cells in mixed chimeras prepared with a nonmyeloablative conditioning regimen and allogeneic bone marrow transplantation.  相似文献   
998.
A normal gonadal maturation with normal fertility are some of the major goals of long-term replacement therapy in adult males with Congenital Adrenal Hyperplasia (CAH). We describe here two young men, G.O. (case A, 23 years old) and S.S.(case B, 24 years old), both with a well defined diagnosis of CAH due to 21-hydroxylase deficiency classic homozygote form (21-CAH). In case A the diagnosis of the 21-CAH classic virilizing form was made at 3 years of age. The patient has undergone glucocorticoid therapy and is now 170 cm tall; all his hormonal findings are within the normal range. The semen analysis has shown a good fertility potential, with a slight modification when the patient decided to discontinue the therapy. In case B the diagnosis of the 21-CAH salt wasting form was performed at 9 days of age. The patient was initially treated with i.v. normal saline solution and a daily i.m. injection of hydrocortisone and, subsequently, with mineral and glucocorticoid replacement therapy po. A satisfactory adult stature (165 cm) was attained. The patient is still on therapy, with a good hormonal profile. The semen analysis has shown an apparently normal fertility. In conclusion, our experience in adult males with 21-CAH, who have been administered prompt and adequate replacement therapy, shows that these patients can attain normal quality of life, satisfactory growth and development, normal sexual maturation and activity, and adequate sperm fertilizing ability, thereby supporting the usefulness of continuing this therapy during adult age.  相似文献   
999.
Proteins of the LIM family are critical regulators of development and differentiation in various cell types. We have described the cloning of cysteine-rich protein 2/smooth muscle LIM protein (CRP2/SmLIM), a LIM-only protein expressed in differentiated vascular smooth muscle cells. As a first step toward understanding the potential functions of CRP2/SmLIM, we analyzed its expression after gastrulation in developing mice and compared the expression of CRP2/SmLIM with that of the other 2 members of the CRP subclass, CRP1 and CRP3/MLP. In situ hybridization in whole-mount and sectioned embryos showed that CRP2/SmLIM was expressed in the sinus venosus and the 2 cardiac chambers at embryonic day 9. Vascular expression of CRP2/SmLIM was first seen at embryonic day 10. At subsequent time points, CRP2/SmLIM expression decreased in the heart but remained high in the vasculature. CRP1 was expressed both in vascular and nonvascular tissues containing smooth muscle cells, whereas CRP3/MLP was expressed only in tissues containing striated muscle. These patterns of expression were maintained in the adult animal and suggest an important role for this gene family in the development of smooth and striated muscle.  相似文献   
1000.
Herpes simplex virus thymidine kinase gene (HSVtk) transfer together with treatment with the prodrug ganciclovir (GCV) represents the most commonly used suicide gene approach for the gene therapy of human central nervous system malignancies. Despite encouraging results reported in clinical trials conducted in adults, very little is known about the feasibility of this approach for the treatment of CNS tumors of childhood. We studied the effects of the HSVtk/GCV system on human medulloblastoma cells in vitro and in vivo. The transfer of tk gene to medulloblastoma cells was capable of mediating cell suicide in vitro and in vivo upon treatment with GCV, but the overall effect in vivo appeared to be suboptimal. The relatively low sensitivity of the medulloblastoma cells to viral infection and a limited bystander effect, coupled with a low expression of connexin-43 protein, might partially explain these results. Whether this is a peculiarity of the cell line studied or a general characteristic of medulloblastoma remains to be determined. These findings should be taken into account for the future planning of gene therapy trials for human medulloblastoma.  相似文献   
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