Intravenous Phenylephrine Preconditioning of Cardiac Grafts From Non–Heart-Beating Donors

Background. Hypoxia and warm ischemia produce severe injury to cardiac grafts harvested from non-heart-beating donors. To potentially improve recovery of such grafts, we studied the effects of intravenous phenylephrine preconditioning.

Methods. Thirty-seven blood-perfused rabbit hearts were studied. Three groups of non-heart-beating donors underwent intravenous treatment with phenylephrine at 12.5 (n = 8), 25 (n = 7), or 50 μg/kg (n = 7) before initiation of apnea. Non-heart-beating controls (n = 8) received saline vehicle. Hypoxic cardiac arrest occurred after 6 to 12 minutes of apnea, followed by 20 minutes of warm in vivo ischemia. A 45-minute period of ex vivo reperfusion ensued. Nonischemic controls (n = 7) were perfused without antecedent hypoxia or ischemia.

Results. Phenylephrine 25 μg/kg significantly delayed the onset of hypoxic cardiac arrest compared with saline controls (9.6 ± 0.5 versus 7.7 ± 0.4 minutes; p = 0.00001), yet improved recovery of left ventricular developed pressure compared with saline controls (57.1 ± 5.3 versus 41.0 ± 3.4 mm Hg; p = 0.04). Phenylephrine 25 μg/kg also yielded a trend toward less myocardial edema than saline vehicle (p = 0.09).

Conclusions. Functional recovery of nonbeating cardiac grafts is improved by preconditioning. We provide evidence that the myocardium can be preconditioned with phenylephrine against hypoxic cardiac arrest.     

Breast Cancer Risk Assessment and Counseling: A Clinician's Guide

Abstract: Most individuals concerned about hereditary breast cancer risk will neither order nor benefit from genetic testing at the present time. Many will, however, seek information about their risk and testing. Risk assessment services, in addition to providing information about hereditary risk and genetic testing, need also to include assessment of non-hereditary risks, information about how to evaluate risks, early detection modalities, the etiology of cancer, and assistance in devising follow-up health care plans. Psychosocial factors, particularly those pertaining to the individual's past history with illness and beliefs about causes and prognosis, must be taken into account to provide relevant information that is understood. A case history with examples of some of the types of information that lead to informed consent in a cancer risk assessment setting is provided.     

灰色系统理论对城市道路交通噪声的建模与预测

以豫西三门峡市1996～2000年道路交通噪声监测数据为依据，运用灰色系统理论建立了GM(1，1)预测模型，经用四种不同方法对模型精度进行检验，均满足要求，用此模型预测三门峡市未来几年道路交通噪声呈下降趋势。     

Comparative study of TRUE Test and Finn Chamber patch test techniques in Singapore

This is a report on a comparative study of the reactivity of TRUE Test and Finn Chamber patch test techniques. 413 patients attending a contact dermatitis clinic in Singapore were simultaneously patch tested with panels 1 and 2 of the TRUE Test standard series and with corresponding allergens (Hermal, Hamburg) using Finn Chambers. The left/right application of the TRUE Test and Finn Chambers was randomized. The concordance of positive patch test reactions to the 2 test techniques was studied. The number of patient with positive reactions was 38% and 42% for TRUE Test and Finn Chamber techniques, respectively (n.s.). The overall concordance of positive patch test reactions was 64% (209/328). 13% (42/328) of positive reactions appeared on TRUE Test only and 24% (77/328) on Finn Chamber only. When only relevant positive reactions were considered, the concordance rate was 67%; 11.6% of positive reactions appeared on TRUE Test only and 21% on Finn Chamber only. Positive reactions to p-phenylenediamine (PPD) and neomycin were more frequent with the Finn Chamber technique than with TRUE Test, i.e., false negative reactions to PPD and neomycin were more likely to occur with TRUE Test. It appeared that the TRUE Test and Finn Chamber techniques were comparable when used for patch testing. However false negative and false positive patch test reactions can occur when using either technique.     

医疗器械不良事件监测-现状与展望

介绍医疗器械不良事件的基本概念,论述美国、欧盟、日本和有关国际组织关于医疗器械不良事件监测的管理规定,并回顾和展望我国在该领域的相关工作.     

Improved anchorage in osteoporotic vertebrae with new implant designs.

The goal of our study was to evaluate two newly developed implant designs and their behavior in terms of subsidence in lumbar vertebral bodies under cyclic loading. The new implants were evaluated in two different configurations (two small prototypes vs. one large prototype with similar load-bearing area) in comparison to a conventional screw-based implant (MACS TL). A pool of 13 spines with a total of 65 vertebrae was used to establish five testing groups of similar bone mineral density (BMD) distribution with eight lumbar vertebrae each. In additional to BMD assessment via dual-energy X-ray absorptiometry, cancellous BMD and structural parameters were determined using a new generation in vivo 3D-pQCT. The specimens were loaded sinusoidally in force control at 1 Hz for 1000 cycles at three load levels (100, 200, and 400 N). A survival analysis using the number of cycles until failure (Cox regression with covariates) was applied to reveal differences between implant groups. All new prototype configurations except the large cylinder survived significantly longer than the control group. The number of cycles until failure was significantly correlated with the structural parameter Tb.Sp. and similarly with the cancellous BMD for three of five implants. In both large prototypes the cycle number until failure significantly correlated with the preoperative distance to the upper endplates. Although the direct relationship between bone structure or density and mechanical breakage behavior cannot be conclusively proven, all the prototypes adapted for poor bone structure performed better than the comparable conventional implant.     

大蒜多糖对肝损伤小鼠血清和肝组织ALT、AST的影响及其急性毒性实验

目的观察大蒜多糖A、B、C对四氯化碳(CCl4)肝损伤小鼠血清和肝组织丙氨酸转氨酶(alanine aminotransferase,ALT)、天冬氨酸转氨酶(aspartate aminotransferase,AST)的影响及其急性毒性测定。方法从大蒜球根中提取有效成分大蒜多糖A、B、C,并测定口服给药LD50及急性毒性限量以观察三者急性毒性;采用CCl4灌胃建立小鼠实验性肝损伤模型,测定小鼠血清和肝组织ALT、AST。结果小鼠口服大蒜多糖A、B、C,均未测出LD50,大蒜多糖A、B、C急性毒性限量试验,安全无毒。大蒜多糖A、B、C治疗使CCl4肝损伤小鼠血清ALT及AST活性显著降低(P<0.01),肝组织ALT及AST活性显著增高(P<0.01);其中,以大蒜多糖C作用最强,优于大蒜素;B次之,与大蒜素相似;A作用最弱,弱于大蒜素。结论大蒜多糖A、B、C均有护肝作用,以大蒜多糖C作用最佳,安全无毒。     

Position as a variable for cardiovascular responses during exercise

Twenty-one normal young male subjects underwent resting and exercise (bicycle) radionuclide angiography in the full supine and 70 degrees upright tilt positions in order to examine the effects of position on left ventricular size and performance, hemodynamics, and exercise duration. All subjects also underwent full (90 degrees) upright bicycle ergometry with respiratory gas analysis to establish the level of maximal exercise capacity for each. Body position significantly (p less than 0.05) affected resting and exercise cardiovascular parameters. End-diastolic and endsystolic left ventricular volumes and stroke volume were larger in the supine position, both at rest and during exercise. The cardiac output at rest and during exercise were comparable for the two positions; an increase in resting and exercise heart rate in the 70 degrees tilt position compensated for the reduced stroke volume of this posture. At maximal exercise, the 70 degrees upright position was associated with a greater response in left ventricular ejection fraction, otherwise this parameter was not position related. Exercise capacity, in terms of duration and workload, was significantly higher in the supine (1870 +/- 390 s) and full upright (1830 +/- 250 s) positions than in the 70 degrees tilt position (1730 +/- 260 s). Changes in body position significantly alter parameters of ventricular, cardiovascular, and exercise performance.     

Dipyridamole-echocardiography test as a clue for assessing the organic 'ceiling' of individual coronary reserve

Twenty-four patients with a history of effort angina, a positiveexercise stress test (EST) and coronary artery disease wereenrolled in the study; 12 patientshada positive dipyridamole-echocardiographytest (DET) and 12 had a negative DET. Each patient performeda total of 4 ESTs in the absence of therapy on two successivedays; for each test the rate-pressure product (RPP), an establishedindex of my ocardial oxygen demand, was measured at the onsetof ischaemia (ST depression >0–15mV) or at the peakof maximal exercise (if a repeated EST was negative). Taking into account the lowest of the 4 RPP values ( x 1/100)in each patient, there was no significant difference betweenDET-negatives and DET-positives (185.2±49.3 vs 157.4±32.4).Conversely, when considering the highest of the 4 RPP valuesin each patient, there was a significant difference betweenDET-negatives and DET-positives (280.3 ± 63.9 vs 183.3± 37.0; p < 0.01). Thus, DET may provide a clinically useful tool for assessingin the individual the organic ’ceiling‘ of coronaryreserve, by eliminating the variability in coronary tone, whichmay affect EST reproducibility and the correct evaluation ofthe impairment of organic coronary reserve.