失眠的评价

失眠的定义失眠分为急性和慢性失眠.急性失眠通常持续时间不超过2 w,与应激状态有关,例如上班、搬家、婚姻或亲人朋友的去世等.而慢性失眠则是失眠持续超过3 w以上,或者不充足睡眠伴随着日间睡意和抑郁,且持续时间不少于1个月.     

对QT离散度实质的探讨

为探讨ＱＴ离散度（ＱＴｄ）的真实意义，观察１３９例急性心肌梗死（ＡＭＩ，ＡＭＩ组）及１０９例正常人（对照组）的最长ＱＴ间期（ＱＴｍａｘ）、校正ＱＴｍａｘ（ＱＴｃｍａｘ）及ＱＴｄ的变化。结果：①ＡＭＩ组的ＱＴｍａｘ、ＱＴｃｍａｘ和ＱＴｄ均显著高于对照组（分别为４２２．６０±３０．５１ｍｓｖｓ３８２．４６±２３．４０ｍｓ、４６０．２１±２８．９６ｍｓｖｓ３８８．５１±２０．１５ｍｓ、５９．８０±２８．４０ｍｓｖｓ３９．４３±１２．２１ｍｓ，Ｐ均＜０．００１）。②ＡＭＩ组中发生严重室性心律失常（ＶＡ）患者（１１４例）的ＱＴｍａｘ、ＱＴｃｍａｘ、ＱＴｄ与无ＶＡ的患者（２５例）相比，均有显著差异（分别为４４８．５８±３３．４０ｍｓｖｓ４１６．１０±３５．３０ｍｓ、４８１．４３±３５．１７ｍｓｖｓ４３９．６０±２７．１０ｍｓ、６６．９０±２０．７２ｍｓｖｓ４８．３２±２３．６１ｍｓ，Ｐ均＜０．００１）。认为ＡＭＩ时ＱＴｄ系Ｔ向量环在不同导联上的“投影”差异所引起的，其异常的本质是ＱＴ间期延长     

Screening for ‘window‐period’ acute HIV infection among pregnant women in rural South Africa

Objectives

The aim of this study was to evaluate the HIV‐1 RNA pooled nucleic acid amplification testing (NAAT) strategy to screen pregnant women in the ‘window period’ of acute HIV infection (AHI) in rural South Africa.

Methods

In 2007 and 2008, 750 consecutive pregnant women on their first antenatal care visit to a primary health care clinic were tested anonymously for HIV infection. HIV‐1 RNA pooled NAAT was performed on HIV antibody‐negative samples. All positive pools were tested individually and positive samples were classified as incident cases to calculate HIV incidence.

Results

The overall HIV prevalence was 37.3% [95% confidence interval (CI) 34.3–41.3]. Of the 467 HIV antibody‐negative samples, four (0.9%) were HIV‐1 RNA‐positive. The mean viral load in the four samples was 386 260 HIV‐1 RNA copies/mL (range 64 200–1 228 130). The HIV incidence was 11.2% per year (95% CI 0.3–22.1) and all women with AHI were ≤21 years of age.

Conclusions

Identifying AHI in pregnancy is important for health interventions to reduce perinatal and heterosexual transmission of HIV, and to estimate HIV incidence for epidemiological surveillance.     

促红细胞生成素对实验性肾性贫血的作用

促红细胞生成素(erythropoietin,EPO)是由肾细胞分泌的一种糖蛋白激素。从人胚肾细胞中诱导,经生物化学方法分离、提纯得到此品。本试验用5/6肾切除的方法造成大鼠慢性肾衰性(CRF)贫血,研究不同剂量EPO对CRF贫血的作用。结果表明EPO有显著的促进红细胞生成,改善CRF贫血状态,使其接近或达到正常水平,最佳剂量为1000 U/kg,并可预防实验性贫血,对正常鼠未见明显作用。     

Regrowth of the rat biliary tree after 70% partial hepatectomy is coupled to increased secretin-induced ductal secretion

BACKGROUND & AIMS: After partial hepatectomy, liver regeneration occurs with the return of hepatocyte mass to normal, Limited data exist regarding the renewal of the biliary tree after partial hepatectomy. This study tested the hypothesis that, after partial hepatectomy, the biliary tree regenerates by proliferation of the remaining cholangiocytes, leading to an increase in secretin-induced ductal bile secretion. METHODS: After 70% partial hepatectomy, cholangiocyte proliferation was assessed in situ by morphometric analysis and In vitro by measurement of 3H-thymidine incorporation. Ductal secretion was estimated by measurement of secretin receptor gene expression and adenosine 3',5'-cyclic monophosphate (cAMP) levels in vitro and by the effect of secretin on ductal bile secretion in vivo. RESULTS: DNA synthesis was undetectable in control cholangiocytes, increased and peaked at day 3 after partial hepatectomy, and returned to normal by day 28. Morphometric analysis showed regrowth of the biliary tree beginning at day 1 with restoration by day 10. The expression of secretin receptor gene and secretin-induced cAMP levels and secretin- induced bicarbonate-rich choleresis increased during the period of bile duct renewal. CONCLUSIONS: After partial hepatectomy, the increase in secretin-induced ductal bile secretion observed during bile duct renewal results from proliferation of remaining cholangiocytes. (Gastroenterology 1996 Dec;111(6):1633-44)     

Reversible oxidant-induced increases in albumin transfer across cultured endothelium: alterations in cell shape and calcium homeostasis

To determine whether reactive oxygen molecules could directly and reversibly increase the transfer of albumin across an endothelial barrier, we measured albumin transfer across monolayers of endothelium cultured on micropore filters before and after exposure to xanthine and xanthine oxidase. Xanthine and xanthine oxidase increased endothelial albumin transfer in a dose-dependent fashion. Parallel phase contrast and fluorescence microscopy demonstrated retraction of adjacent cells from one another and disruption of the actin filaments. The oxidant- induced increases in albumin transfer and changes in cell shape were reversed by removing xanthine oxidase and then incubating the monolayers for 3 1/2 hours in tissue culture media enriched with fetal bovine serum. However, incubation in tissue culture media without serum resulted in progressive injury and cell death. Hence, the brief exposure to oxidants initiated a progressive injury process that was reversed by incubation in serum. Because intracellular and extracellular calcium are important determinants of cell shape, and because some oxidized membrane lipids act as calcium ionophores, we asked whether oxidants altered endothelial calcium homeostasis. Xanthine-xanthine oxidase increased release of 45Ca++ from preloaded cells. The calcium antagonist lanthanum chloride prevented xanthine- xanthine oxidase increases in endothelial albumin transfer and prevented the changes in cell shape; chelation of extracellular calcium inhibited lysis of endothelium by xanthine-xanthine oxidase; and the calcium ionophore A23187 increased endothelial albumin transfer and mimicked the oxidant-induced changes in cell shape. Lanthanum chloride inhibited these effects of A23187. These data suggest that oxygen radicals can reversibly increase endothelial permeability to macromolecules, that this is associated with reversible changes in endothelial cell shape and actin filaments, and that the changes in cell shape are related to oxidant-induced changes in endothelial calcium homeostasis.     

Patterns of cell proliferation and cell migration in the Sezary syndrome

The patterns of cell proliferation and cell migration were studied in three patients with the Sezary syndrome using autoradiographic techniques. Cell labeling patterns following pulse labeling with tritiated thymidine in vivo indicated that Sezary cells proliferate actively in skin and in lymph nodes but that few if any Sezary cells proliferate in the peripheral blood. In two of the patients serial samples were obtained. Label dilution patterns in skin and blood over time suggested that circulating Sezary cells originated in extracutaneous sites where cells were proliferating more rapidly than in the skin. Cells labeled in extracutaneous sites of proliferation appear rapidly in the blood, and their transit time through the peripheral blood compartment is short. Circulating Sezary cells may then be deposited in the skin where they resume proliferation at a low rate. Thus, while Sezary cells proliferate in both cutaneous and extracutaneous sites, proliferation appears to be more rapid in extracutaneous sites such as lymph nodes. This suggests that trials of systemic therapeutic approaches should be undertaken.     

Engraftment of bone marrow cells into normal unprepared hosts: effects of 5-fluorouracil and cell cycle status

Bone marrow from animals treated with 5-fluorouracil (5FU) competes equally with normal marrow when assessed in vivo in an irradiated mouse, but shows markedly defective engraftment when transplanted into noncytoablated hosts. Using Southern Blot analysis and a Y-chromosome specific probe, we determined the level of engraftment of male donor cells in the bone marrow, spleen, and thymus of unprepared female hosts. We have confirmed the defective engraftment of marrow harvested 6 days after 5FU (FU-6) and transplanted into unprepared hosts and shown that this defect is transient; by 35 days after 5FU (FU-35), engraftment has returned to levels seen with normal marrow. FU-6 marrow represents an actively cycling population of stem cells, and we hypothesize that the cycle status of the stem cell may relate to its capacity to engraft in the nonirradiated host. Accordingly, we have evaluated the cycle status of engrafting normal and FU-6 marrow into normal hosts using an in vivo hydroxyurea technique. We have shown that those cells engrafting from normal marrow and over 70% of the cells engrafting from FU-6 marrow were quiescent, demonstrating no killing with hydroxyurea. We have also used fluorescent in situ hybridization (FISH) analysis with a Y-chromosome probe and demonstrated that normal and post-5FU engraftment patterns in peripheral blood were similar to those seen in bone marrow, spleen, and thymus. Altogether these data indicate that cells engrafting in normal, unprepared hosts are dormant, and the defect that occurs after 5FU is concomitant with the induction of these cells to transit the cell cycle.