Serologic test for syphilis as a surrogate marker for human immunodeficiency virus infection among United States blood donors

BACKGROUND: This study evaluated the usefulness of the serologic test for syphilis (STS) in preventing the transmission of human immunodeficiency virus (HIV), hepatitis B and C viruses, and human T- lymphotropic virus via the transfusion of seronegative, infectious window-period blood. STUDY DESIGN AND METHODS: Demographic and laboratory information on blood donations made between January 1992 and June 1994 in 18 American Red Cross regions was analyzed. It was assumed that the same proportion of HIV-positive and HIV-infectious window- period donations reacted on STS and were negative on other screening tests (hepatitis B and C viruses and human T-lymphotropic virus). This proportion multiplied by the estimated number of HIV-infectious window- period donations is the number of post-screening HIV-infectious donations removed by STS. RESULTS: Of 4,468,570 donations, 12,145 (0.27%) were STS positive and 377 (0.008%) were HIV positive. Among donations that were negative on other screening tests, STS-reactive donations were 12 times more likely to be HIV positive (odds ratio = 11.9; 95% CI = 5,26). However, of an estimated 13 infectious window- period donations, 0.2 would have been removed because of a reactive STS, at a cost of over $16 million. CONCLUSION: STS is a poor marker and a costly strategy for preventing post-screening HIV infections and other blood-borne diseases.     

Pneumothorax preceding pulmonary blastoma in a child

Serial plain radiographic, ultrasound and CT findings of an unusual case of pulmonary blastoma are described with a review of the literature.     

Lymphokine-activated killer (LAK) activity to cultured rat kidney parenchymal components in vitro

Abstract. The susceptibility of cultured rat kidney parenchymal components to natural killer (NK) cell and lymphokine-activated killer (LAK) cell-mediated lysis in a 4-h in vitro ⁵¹chromium assay was investigated. Large granular lymphocytes (LGL) in the spleen and in the kidney allograft were able to lyse YAC cells during rejection, but they did not damage target endothelial, glomerular mesangial, glomerular epithelial, or tubular cells in resting state. Stimulation of the target cells with gamma-interferon - known to induce MHC (class II) antigens on the target cell surface - did not make the target cells susceptible to NK-mediated lysis. LAK cells generated by a 3-day incubation with interleukin-2 (IL-2) effectively lysed both YAC and P815 target cell lines. LAK cells were also slightly cytotoxic to all tested parenchymal target components in resting state. Gamma-interferon treatment of the cultured parenchymal cells prior to the chromium release assay, however, reduced LAK-mediated parenchymal cell cytotoxicity to nearly nondetectable levels. Obviously, many lymphokines, including IL-2 and gamma-interferon, are produced during rejection at the site of inflammation. This might induce the generation of LAK cells in situ as the lymphokines induce the production of MHC antigens in the graft. We interpret these findings as indicating that regardless of the generation of LAK, the protective effect of gamma-interferon neutralizes the LAK effect, and we suggest that neither LGL nor LAK cells play any essential role in rat kidney allograft rejection.     

The Kheda malaria project: the case for environmental control

The Kheda project experience has shown that bio-environmentalcontrol of malaria is feasible, cost effective and ecologicallysound. It clearly brings out the need to consider health issuesat the planning stage of all developments. Bio-environmentalcontrol of malaria is suggested as the first line of attackfor the control of mosquitoes, malaria and other mosquito-bornediseases. Insecticides may be reserved for short-term use. Thiswill enable judicious and selective use of insecticides in solelyepidemic situations. The growing problem of resistance to insecticidesin mosquitoes as well as environmental pollution, can then besolved on a long term basis.     

In vivo release and turnover of secreted platelet antiheparin proteins in rhesus monkey (Macaca mulatta)

Human and rhesus monkey platelets secrete at least two antiheparin proteins: platelet factor 4 (PF4) and low affinity platelet factor 4 (LA-PF4). Neither of these proteins showed species-related antigenic differences. As determined by radioimmunoassay, the levels of PF4 and LA-PF4 antigen per 10(9) monkey platelets amounted to 10.7 and 20.3 microgram, respectively. One milliliter of monkey plasma prepared from blood collected into an anticoagulant composed of EDTA, prostaglandin E1, and theophylline solution contained 22.4 ng LA-PF4 and 8.0 ng PF4. Concentrations of these two platelet-specific proteins in monkeys closely resembled levels found in human platelets and plasma. Infusion of prostacyclin (PGI2) (100 or 300 ng/kg/min) into monkeys for 15 min resulted in a significant decrease of plasma levels of LA-PF4 antigen and of PF4 by 40%--60% (p < 0.0001). This decrease was related to the inhibitory effect of PGI2 on the secretion of platelets stimulated by a catheter or by venipuncture. Longer infusion of PGI2 did not produce further significant change. The supernate obtained after aggregation of human platelets stimulated by thrombin was injected into monkeys receiving PGI2 infusion. The disappearance of LA-PF4 antigen in monkey plasma followed a biphasic exponential curve with half-lives for the fast and slow components of 8.4 and 63 min. PF4 disappeared faster but followed the same pattern (half-lives for the fast and slow component of 2.1 and 70 min). Analysis of the experimental data suggests that the low levels of secreted platelet proteins in monkey plasma are related to their minimal in vivo release and to their rapid clearance.     

皮下静脉的红外成像

研究背景和目的 　　在急诊救治的过程中最重要的就是快速建立静脉通道,以补充体液、给药以及输血等.但是,由于皮下结构(如血管深度、脂肪组织、皮肤色素、血管内血容量)的复杂性,往往阻碍了肉眼下静脉穿刺过程的实施.血管超声可以辅助寻找相对较粗的静脉,但是此设备和技术的要求较高,影响了其在临床的广泛应用;可见光透射法所得结果不甚可靠,且容易造成灼伤.红外成像时由于其穿透深度较可见光深,而且血液对红外光能量的吸收明显高于脂肪和黑色素等血管周围组织,因而可以得到对比度清晰的图像.……     

Comparative Analysis of Accumulation of Chlorine e6 and Hematoporphyrin Derivatives in Subpopulations of Peripheral Blood Lymphocytes

We studied accumulation of porphyrin photosensitizers chlorine e6, hematoporphyrin, and their derivatives by different lymphocyte subpopulations. The intensity of staining of B lymphocytes and natural killer cells with photosensitizers was higher compared to T lymphocytes. T cell subpopulation differed by their ability to bind photosensitizers. Relative accumulation of dimethyl esters of chlorine e6 and hematoporphyrin in cells surpassed that of nonesterified porphyrins.