Synthesis of coagulation factor V by cultured aortic endothelium

Bovine aortic endothelium has been examined with respect to the synthesis of coagulation factor V. After cultured cells reached confluency, samples of supernatant culture media and solubilized cells were analyzed for factor V in a two-stage bioassay and in a double- antibody radioimmunoassay. In addition, preconfluent cells were pulsed for 4 days with 35S-methionine in methionine-free media. After the 4- day pulse, supernatant media were chromatographed on a factor V monoclonal antibody-Sepharose resin to isolate 35S-labeled factor V. The isolated material and 125I-factor V standards were analyzed by electrophoresis and autoradiography. The bioassay indicated an increase, with time, of unactivated factor V in the culture supernatant, whereas solubilized cells were negative for factor V. The radioimmunoassay indicated an increase, with time, of factor V antigen in the culture supernatants, and the solubilized cells yielded a constant level of antigen per cell. Autoradiograms of electrophoretograms of immunoadsorbed 35S-culture supernatant with 125I- factor V/Va standards revealed labeled proteins with electrophoretic mobilities compatible with 125I-factor V/Va standards. The data obtained from three different sources-bioassay, radioimmunoassay, and 35S-methionine incorporation-all indicate that factor V is synthesized by cultured bovine aortic endothelium.     

P-selectin mediates spontaneous leukocyte rolling in vivo

Rolling represents the initial step leading to leukocyte extravasation from blood vessels during an inflammatory reaction. In vitro studies indicate that P-selectin could be one of the ligands on endothelium involved in the rolling phenomenon, although the molecular determinants responsible for this transient attachment in vivo are still undefined. Our objectives were to develop a blocking monoclonal antibody against canine P-selectin and to use it to investigate the role of P-selectin in leukocyte rolling in vivo using the technique of intravital microscopy. P-selectin was immunoaffinity purified from canine platelets and used for the production of monoclonal antibodies. One of the hybridomas generated, MD6, was shown by enzyme-linked immunosorbent assay and by flow cytometry to bind preferentially to stimulated platelets and to completely prevent binding of stimulated platelets to neutrophils. Visualization of canine mesenteric venules by intravital microscopy showed that administration of MD6 resulted in a marked inhibition in the number of rolling leukocytes (18.96 +/- 9.92 v 156.40 +/- 19.50 leukocytes/min, P < .05; 88.3% +/- 6.0% inhibition). Control antibody MD3 (which recognizes a nonfunctional epitope of canine P- selectin) had no effect on the number of rolling leukocytes or on their rolling velocity. These results show for the first time that P-selectin plays an essential role in leukocyte rolling in vivo, and therefore may be a key participant of the inflammatory response.     

Glucocorticoid-stimulated,transcription-independent release of annexin A1 by cochlear Hensen cells

Background and purpose:

The current clinical strategy to protect the auditory organ against inflammatory damage by migrating leukocytes is the local delivery of glucocorticoids. However, the mechanism by which glucocorticoids confer this protection remains unknown. Therefore, we investigated the cellular and molecular targets of glucocorticoids in the cochlea that could be involved in preventing leukocyte migration.

Experimental approach:

We used microscopy as well as immunocytochemical and microfluidic techniques to elucidate the effect of dexamethasone, hydrocortisone and prednisolone on the cellular and intracellular distribution of annexin A1 (ANXA1) – a glucocorticoid target known to inhibit leukocyte migration by receptor-mediated signalling – in the cochlea and isolated cochlear cells of guinea pigs.

Key results:

All the cells lining the scala media – the cochlear compartment containing the auditory organ – express ANXA1 and the ANXA1 receptor FPR2/ALX is present in the scala media, as well as in other cochlear ducts. The majority of ANXA1 in the scala media is stored inside lipid droplets within cochlear Hensen cells. Glucocorticoids activate a myosin IIC-mediated mechanism that drives ANXA1 from the lipid droplets to the apical region of the Hensen cells, where ANXA1 is released to the external milieu by a process involving ABC transporters.

Conclusions and implications:

These findings suggest that ANXA1 could be a major mediator of the anti-inflammatory effects of glucocorticoids in the cochlea and identify new molecular targets for prevention of sudden sensorineural hearing loss.     

单亲家庭大学生心理健康状况调查

目的:了解单亲家庭大学生的心理健康状况,并与普通家庭大学生比较。方法:2006-04/05在某医学院校根据学生学号末尾数字随机抽取普通家庭学生345名,其中享受学校减免学费的贫困学生58名,通过查阅学生学籍表的方法获得单亲家庭学生133名,其中享受学校减免学费的贫困学生39名。采用症状自评量表对其心理健康状况进行调查,以量表中各因子均分作为心理健康状况的具体指标,分数越高,表明心理健康状况越差。结果:普通家庭学生有效问卷312份,其中贫困学生有效问卷43份;单亲家庭学生有效问卷104份,其中贫困学生有效问卷32份。①单亲家庭大学生的心理健康状况与普通家庭大学生比较,差异无显著性(P>0.05)。②单亲贫困大学生的强迫和人际敏感因子得分显著低于普通贫困大学生(1.57±0.38,1.87±0.64;1.46±0.41,1.73±0.62,t=2.289,2.265,P<0.05)。③单亲家庭男大学生的强迫、人际敏感和敌对因子得分显著低于普通家庭男大学生(1.50±0.33,1.77±0.47;1.40±0.37,1.63±0.49;1.29±0.34,1.46±0.46,t=2.848,2.750,2.276,P<0.01,0.01,0.05)。单亲家庭女大学生的心理健康状况与普通家庭女大学生比较,差异无显著性(P>0.05)。结论:单亲家庭大学生的心理健康状况与普通家庭总体上并无明显差异。     

2002 Australian Radiology Workforce Report

This paper describes the current status of radiologist provision in Australia, and explores issues relating to its current adequacy, as well as analysing projections of supply and requirements, and their balancing. Data are drawn from several sources including the results of the Royal Australian and New Zealand College of Radiologists Workforce Survey 2000, and the report of the Australian Medical Workforce Advisory Committee Radiology Working Party 2001. The main conclusions to be drawn are that: (i) there is a current shortfall of radiologist supply in Australia; (ii) future requirements (taking all factors into consideration) are expected to grow at a greater rate than projected supply (based on the status quo); and (iii) supply of radiologists should therefore be increased. These conclusions are roughly in line with those from other countries, such as the UK, Canada and USA. Radiologists practising in Australia also appear to have relatively high productivity, including by some international comparisons. These findings are presented in the context of current issues in Australian medical imaging, including provider consolidation and corporatization, globalization and funding.