酶联免疫吸附试验中影响全自动加样系统加样准确性的因素分析

目的探讨酶联免疫吸附试验(ELISA)中使用不同容量加样针和分液高度,对全自动加样系统加样准确度和精密度的影响。方法选取10μL和100μL两种加样量,每种加样量分4个小组进行实验,分别使用不同容量(400μL和800μL)的加样针和不同分液高度(浸润和未浸润)加样,计算每组的最终加样量、均值相对误差(E)和变异系数(CV),与实际工作标准进行比较。结果10μL加样E在-37.9%~-2.8%,CV在3.29%~14.49%;100μL加样E在-1.9%~0.8%,CV在0.44%~0.95%。结论不同容量加样针和分液高度对10μL加样影响较为明显,对100μL加样影响较小,在使用全自动加样系统进行ELISA时,应当选择适当容量的加样针和分液高度。     

Plasma lipoproteins in visceral leishmaniasis and their effect on Leishmania‐infected macrophages

This work aimed at investigating the lipid profile of zoonotic visceral leishmaniasis (VL) patients’ sera and the effect of lipoproteins on the in vitro production of tumour necrosis factor‐α (TNF‐α), interleukin (IL)‐6, IL‐10 and IL‐12 by Leishmania infantum‐infected and uninfected macrophages. Lipids were quantified in 26 VL patients’ sera and 26 healthy controls from a VL endemic area. The patients’ sera had higher triglyceride and very low density lipoprotein (VLDL) levels, and much lower apolipoprotein A1, total cholesterol, low density lipoprotein (LDL) and high density lipoprotein (HDL) levels than the control sera. Lipoprotein fractions were obtained by ultracentrifugation of sera. The addition of LDL and HDL to Leishmania‐infected and uninfected macrophages, in physiological concentrations, enhanced the production of IL‐6 and IL‐10, but not of IL‐12. LDL stimulated the production of TNF‐α only in infected macrophages, whereas HDL stimulated the production of lower amounts of TNF‐α in both infected and uninfected macrophages. VLDL stimulated only the production of IL‐10. It is proposed herein that LDL may influence the development of VL by promoting the production of TNF‐α by infected macrophages. A decrease in plasma LDL in some VL patients (to 20 mg/mL or less); however, would tend to reduce the production of TNF‐α and therefore to limit the development of immune‐mediated pathology, not withstanding the fact that it would perhaps increase the permissiveness of macrophages to Leishmania growth.     

Medication Use Quality and Safety in Older Adults: 2018 Update

Improving the quality of medication use and medication safety is an important priority for prescribers who care for older adults. The objective of this article was to identify key articles from 2018 that address these issues. In addition, we selected four of these articles to annotate, critique, and discuss their broader implications for clinical practice. The first study highlights a cluster‐randomized trial that utilized a pharmacist‐led education‐based intervention delivered to both patients and physicians to deprescribe four types of inappropriate medications (sedative‐hypnotics, first‐generation antihistamines, selective nonsteroidal anti‐inflammatory drugs, and glyburide). The second study, a nested case‐control study using data from within the UK Clinical Practice Research Datalink, examined the association between anticholinergic exposure, overall and by anticholinergic medication class, and dementia risk in 40 770 older adults. The third study, a longitudinal cohort study of 1028 Swedish older adults, examined the association between antihypertensive medications and incident dementia. The last study was a randomized, double‐blind, placebo‐controlled trial that investigated the effect of daily low‐dose aspirin (100 mg) for primary prevention on cardiovascular events and major hemorrhage in 19 144 community‐dwelling older adults. Collectively, this current article provides insight into the pertinent topics of medication use quality and safety in older adults and helps raise awareness about optimal prescribing in older adults. J Am Geriatr Soc 67:2458–2462, 2019     

A comparison of static and dynamic wrist splints using electromyography in individuals with rheumatoid arthritis.

This study compared strength, dexterity, and the muscle activation of individuals with rheumatoid arthritis (RA) when different splints were worn. Five persons with RA were observed in four splint conditions (none, static, hinged, spiral) during grip, pinch, and dexterity tests by recording muscle activity of eight muscles in the upper extremity using electromyography (EMG). Statistically significant differences were found in clinical tests when hinged (p<0.001) and spiral splints (p=0.02) were worn. Grip strength decreased when hinged splints were worn, whereas two-point pinch increased and dexterity improved on the Nine-Hole Peg Test with the spiral splint. Although no significant EMG differences were found during different splint conditions, wrist muscles were recruited more for grip, and shoulder muscles were used most during pinch and dexterity tests. Individuals with RA who wore splints had decreased grip when wearing hinged splints, but improved pinch and dexterity were found when the spiral splint was worn. Increased use of proximal shoulder muscles was observed during pinch and dexterity tests with and without splints.     

Measuring dexterity in children using the Nine-hole Peg Test.

The purpose of this study was to measure dexterity in children aged 4-19 years using the Nine-hole Peg Test. Four hundred and six children were tested with their dominant hand and then their nondominant hand. A commercial version of the Nine-hole Peg Test was used. An analysis of variance showed a main effect for age, gender, and hand dominance. Speed of dexterity improved with age. In all age groups, females performed faster than males. Participants performed faster with the dominant hand than the nondominant hand. The normative data collected provide information for comparing scores to children with different diagnostic categories to screen for fine motor difficulties.     

Acceleration of thrombin-antithrombin complex formation in rat hindquarters via heparinlike molecules bound to the endothelium.

We have examined the role of heparinlike molecules in the regulation of coagulation by perfusing rat hindquarters with purified human thrombin and with its plasma inhibitor, antithrombin. Our data indicate that contact of the hemostatic components with the endothelium enhances the rate of thrombin-antithrombin complex formation by as much as 19-fold over the uncatalyzed rate of enzyme-inhibitor interaction. Heparinlike molecules are responsible for the antithrombin accelerating activity. The amount of thrombin-antithrombin complex generated within the hindlimb preparation after pretreatment of the vasculature with purified Flavobacterium heparinase or with addition of platelet Factor IV to the hemostatic components, was equal to the uncatalyzed levels. These heparinlike molecules appear to be tightly bound to the luminal surface of the endothelium, since they could not be detected within the physiologic buffer that was perfused through the animal. The above mucopolysaccharides function in a manner similar to commercial heparin, since modification of antithrombin at a site critical for heparin-dependent acceleration of the protease inhibitor resulted in a level of interaction product identical to the uncatalyzed amount. Finally, addition of diisofluorophosphate-thrombin to the enzyme perfusion stream reduced the amount of thrombin-antithrombin complex formed in the animal by 30-40%, which suggested that thrombin bound to the endothelium as well as enzyme free in solution are accessible to antithrombin that has interacted with heparinlike molecules present on the endothelium.     

Clotting enzyme activity derived from the coelomocytes of the sea star Asterias forbesi

Clotting enzyme activity was detected in lysates prepared from the coelomocytes of Asterias forbesi following incubation with endotoxin-activated Limulus amebocyte lysate. This activity was not detected in the cell-free coelomic fluid. The enzymatic activity from the sea star lysate hydrolyzed the synthetic substrate S2222 but not S2238 or S2251, and polymerized partially purified Limulus clottable protein. The clotting enzyme activity was not detected following treatment of the sea star cell lysate with endotoxin or with the clotting enzyme from Limulus lysate. The enzymatic activity, generated in sea star cell lysate by the activated Limulus lysate, was inhibited by the addition of benzamidine; and its effect was suppressed with rabbit anti-sera directed against Asterias whole cell lysate, but not with anti-sera directed against the previously reported Sea Star Factor.