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91.
92.
Hematocrit level and associated mortality in hemodialysis patients 总被引:22,自引:0,他引:22
Ma JZ Ebben J Xia H Collins AJ 《Journal of the American Society of Nephrology : JASN》1999,10(3):610-619
Although a number of clinical studies have shown that increased hematocrits are associated with improved outcomes in terms of cognitive function, reduced left ventricular hypertrophy, increased exercise tolerance, and improved quality of life, the optimal hematocrit level associated with survival has yet to be determined. The association between hematocrit levels and patient mortality was retrospectively studied in a prevalent Medicare hemodialysis cohort on a national scale. All patients survived a 6-mo entry period during which their hematocrit levels were assessed, from July 1 through December 31, 1993, with follow-up from January 1 through December 31, 1994. Patient comorbid conditions relative to clinical events and severity of disease were determined from Medicare claims data and correlated with the entry period hematocrit level. After adjusting for medical diseases, our results showed that patients with hematocrit levels less than 30% had significantly higher risk of all-cause (12 to 33%) and cause-specific death, compared to patients with hematocrits in the 30% to less than 33% range. Without severity of disease adjustment, patients with hematocrit levels of 33% to less than 36% appear to have the lowest risk for all-cause and cardiac mortality. After adjusting for severity of disease, the impact of hematocrit levels of 33% to less than 36% is vulnerable to the patient sample size but also demonstrates a further 4% reduced risk of death. Overall, these findings suggest that sustained increases in hematocrit levels are associated with improved patient survival. 相似文献
93.
GABA(A) receptors mediate inhibition of T cell responses 总被引:4,自引:0,他引:4
We describe the presence of functional GABA(A) receptors on T cells. GABA inhibited anti-CD3 and antigen-specific T cell proliferation in vitro in a dose-dependent manner that was 1) mimicked by the GABA(A) receptor agonist muscimol (but not the GABA(B) receptor agonist baclofen), 2) blocked by GABA(A) receptor antagonists and a GABA(A) receptor Cl- channel blocker (picrotoxin) and 3) enhanced by pentobarbital. These data suggest that GABA(A) receptors mediate this immune inhibition and that these receptors can be modulated in a similar fashion to their neuronal counterparts. Finally, GABA inhibited DTH responses in vivo. Thus, pharmacological modulation of GABA(A) receptors may provide new approaches to modulate T cell responses in inflammation and autoimmune disease. 相似文献
94.
95.
目的 探讨抑那通和缓退瘤联合治疗对正常前列腺,增生的前列腺(BPH)和前列腺癌以及睾丸的作用。方法 对16例接受联合内分泌治疗至少3个月且有治疗前后病理资料的前列腺癌患者的标本进行了系统的病理学检查。对内分泌治疗后的睾丸标本与同龄未接受治疗的进行对照研究。结果 14例内分泌治疗后的前列腺标本2例未见残存癌灶,9例对治疗有明显的反应;3例对治疗反应差,治疗并未降低前列腺癌的病理分期。3例内分泌治疗后 相似文献
96.
Protein kinase C has been implicated as a cellular target for Pb2+ toxicity. We have previously proposed that Pb2+ modulates PKC activity by interacting with multiple sites within the enzyme. In order to further characterize the Pb-PKC interactions we compared the effects of Pb2+ on the CA-dependent and -independent protein kinase C isozymes using recombinant human PKC-alpha, PKC-epsilon, and PKC-zeta as well as the catalytic fragment of bovine brain protein kinase C, the PKC-M. The results demonstrate that, whereas at pM concentrations Pb2+ activates PKC-alpha half maximally (KAct approximately 2 pM), it has no effect on PKC-epsilon, PKC-zeta, or PKC-M activities. The activation of PKC-alpha by Pb2+ is additive with Ca2+ in a manner indicating interaction with half of the calcium activation sites. In the micromolar range of concentrations, Pb2+ inhibits all PKCs with estimated K0.5 of 1.0, 2.3, 28, and 93 microM for PKC-M, PKC-alpha, PKC-epsilon, and PKC-zeta, respectively. Examination of Pb2+ effects on PKC-M kinetics indicates a mixed type inhibition with respect to ATP and noncompetitive inhibition with respect to histone. Taken together with the results of our previous study (Tomsig and Suszkiw, J. Neurochem. 64, 2667-2673, 1995) and the evidence for the existence of two Ca2+ coordination sites Ca1 and Ca2 within the C2 domain (Shao et al., Science [Washington, D.C.] 273, 248-251, 1996), the results of the current study provide further support for a multisite Pb-PKC interaction scheme wherein lead (1) partially activates the enzyme through pM-affinity interactions with the Ca1 site and inhibits the divalent cation-dependent activity through nM-affinity interactions with Ca2 site in the C2 domain and (2) inhibits the constitutive kinase activity through microM-affinity interactions with the catalytic domain. The concentration dependence of the differential effects of Pb2+ on the calcium-dependent and -independent PKCs underscores the importance of the C2 motif as a high affinity molecular target for Pb2+. 相似文献
97.
左旋四氢巴马汀对单个豚鼠心室肌细胞钙电流的阻滞作用 总被引:4,自引:0,他引:4
AIM: To study the effect of l-tetrahydropalmatine (l-THP) on L-type calcium channel. METHODS: Patch clamp technique (whole cell recording) was used to record L-Ca2+ current in single cardiac myocyte. RESULTS: 1) l-THP 1, 10, and 100 micromol.L-1 reduced ICa-max from (999 +/- 93) pA to (700 +/- 111) pA, (582 +/- 66) pA, and (420 +/- 112) pA (n = 6, P < 0.01), respectively. 2) l-THP reduced the voltage at half-maximal inactivation (V1/2) of L-Ca2+ channel to more negative potentials by 9 mV (n = 5, P < 0.05). 3) l-THP caused both tonic and use-dependent reduction of Ca2+ current. Tonic block of l-THP on Ca2+ current was 46% +/- 8% (n = 6, P < 0.01). The degree of use dependent blocking was 13.5% +/- 2.4% (n = 6, P < 0.05) at 1 Hz, the degree increased to 44% +/- 5% (n = 6, P < 0.01) at 3 Hz. 4) l-THP delayed half-recovery time of Ca2+ channel recovery from inactivity from (94 +/- 39) ms to (170 +/- 42) ms(n = 6, P < 0.01). CONCLUSION: l-THP has a moderate inhibitory effect on L-Ca2+ current. 相似文献
98.
The natural history of classic mucinous cystic neoplasms of the pancreas has been previously defined. In this report, an unusual variant of a pancreatic mucinous cystic neoplasm, termed "mucinous pancreatic duct ectasia of latent malignancy," is described. The lesion is characterized by massive dilatation of the main pancreatic duct and its tributaries. Histologically, the ducts are lined by epithelium, which is indistinguishable from the classic mucinous cystic neoplasms. Until the natural history of classic mucinous cystic neoplasm is better documented, resection appears to be the treatment of choice. 相似文献
99.
100.
目的 探讨磁极化生物平衡离子吸附降脂降粘疗法(也称之为洗血疗法)对老年心脑血管病危险因素的临床疗效。方法 应用磁极化生物平衡离子吸附疗法对22例老年患有心脑血管病危险因素的患者进行治疗,并对临床各项指标进行对照比较。结果 22例患者治疗前后的血流变学指标、血脂等均有明显改善。治疗前患者的TCHO(胆固醇)、TG(甘油三酯)分别为(6.21±1.14)mmol/L和(6.78±5.13)mmol/L;治疗后分别为(4.36±0.99)mmol/L和(2.41±2.10)mmol/L,P<0.05,均显著降低。治疗前患者的HCT(红细胞压积)、PFC(纤维蛋白)、NP(血浆粘度)、NR(全血粘度)、VAI(细胞聚集指数)分别为(0.441±0.042)V、(4.11±1.78)g/L、(3.86±1.98)mpa.s、(5.68±0.79)mpa.s和0.89土0.23;治疗后分别为(0.344±0,061)V、(2.21±1.12)g/L、(1.49±0.40)mpa.s、(3.21±0.56)mpa.s和0.40±0.15,治疗前后对照比较,P<0.02。结论本方法对老年人心脑血管病危险因素的治疗是有效的。 相似文献