Hemopathologic consequences of protracted gamma irradiation: alterations in granulocyte reserves and granutocyte mobilization

Aplastic anemia and myelogenous leukemia are prominent pathologic effects in beagles exposed to continuous, daily, low-dose gamma irradiation. In the present work, granulocyte reserves and related mobilization functions have been sequentially assessed by the endotoxin stress assay during the preclinical and clinical phases of these hemopoietic disorders. Characteristic patterns of granulocyte reserve mobilization are described that reflect given stages of pathologic progression. For radiation-induced leukemia, a five stage pattern has been proposed. In contrast, a simple pattern of progressive, time- dependent contraction of granulocyte reserves and mobilization capacity was noted in the development of terminal aplastic anemia. Early preclinical phases of radiation-induced leukemia appear to involve an extensive depletion of the granulocyte reserves ((phase I) during the first approximately 200 days of exposure followed by a partial renewal of the reserves and associated mobilization functions approximately 200 and 400 days (phase II). Sustained, subnormal granulocyte mobilizations (phase III) following endotoxin stress typify the responses of dogs during the intermediate phase, whereas late preclinical, preleukemic stages (phase IV) are characterized by a further expansion of the reserves and in the mobilization capacities, particularly of the less mature granulocytes. Such late alterations in the pattern of granulocyte mobilization, together with other noted cellular aberrancies in the peripheral blood and marrow, appear to indicate leukemia (phase V) onset.     

Lower limb vasodilatory capacity is not reduced in patients with moderate COPD

We compared exercise capacity (peak O₂ uptake; V̇O_2peak) and lower limb vasodilatory capacity in 9 patients with moderate COPD (FEV₁ 52.7 ± 7.6% predicted) and 9 age-matched healthy control subjects. V̇O_2peak was measured via open circuit spirometry during incremental cycling. Calf blood flow (CBF) measurements were obtained at rest and after 5 minutes of ischemia using venous occlusion plethysmography. While V̇O_2peak was significantly lower in the COPD patients (15.8 ± 3.5 mL·kg⁻¹·min⁻¹) compared with the control group (25.2 ± 3.5 mL·kg⁻¹·min⁻¹), there were no significant differences between groups in peak CBF or peak calf conductance measured 7 seconds post-ischemia. V̇O_2peak was significantly correlated with peak CBF and peak conductance in the control group, whereas no significant relationship was found between these variables in the COPD group. However, the rate of decay in blood flow following ischemia was significantly slower (p < 0.05) for the COPD group (−0.036 ± 0.005 mL·100 mL⁻¹·min⁻¹·s⁻¹) when compared with controls (−0.048 ± 0.015 mL·100 mL⁻¹·min⁻¹·s⁻¹). The results suggest that the lower peak exercise capacity in patients with moderate COPD is not related to a loss in leg vasodilatory capacity.     

Apparent Acute Reversible Right Ventricular Pacing‐Induced Left Ventricular Dysfunction

Apparent Acute Reversible Right Ventricular Pacing‐Induced Left Ventricular Dysfunction . We report the case of a 70‐year‐old Caucasian male with a dual chamber (right atrium/right ventricle) pacemaker implanted for sinus node dysfunction and not pacemaker (PM) dependent who was found to have an apparent acute worsening of left ventricular (LV) function with right ventricular (RV) apical pacing caused by the mode switch to VVI pacing as battery depletion occurred. LV dysfunction resolved immediately with RV pacing turned off. To our knowledge, this is the first report of this phenomenon. (J Cardiovasc Electrophysiol, Vol. 24, pp. 224‐226, February 2013)     

Coronary Angioplasty in Low Risk Patients with Low Dose Heparin and Immediate Withdrawal of the Femoral Sheath

This study reports our preliminary experience of percutaneous coronary angioplasty with low dose heparin and immediate withdrawal of the femoral sheath. After selection, 120 patients underwent a procedure with a low dose of heparin (4,300 ± 700 IU). A total of 120 of 123 lesions (97.6%) were treated successfully by the femoral route. There were no major cardiac complications during the procedure and hospital stay. Patients were allowed to be ambulant 6 hours after the procedure. No significant bleeding occurred. There was no need for surgery relative to the approach route nor for blood transfusion. The use of low dose heparin and immediate withdrawal of the femoral sheath did not increase the risk of coronary angioplasty in these selected patients. The period of bed confinement was shortened and the patients were ambulant earlier, leading to a reduction in their hospital stay with no increase in costs.     

贯叶金丝桃愈伤组织的诱导及其有效成分的定性

目的 :诱导出贯叶金丝桃的愈伤组织 ,并确定其中含有金丝桃素。方法 :在不同条件下采用组织培养技术 ,进行贯叶金丝桃的愈伤组织诱导研究 ,用HPLC方法确定其中含有的金丝桃素。结果和结论 :最佳诱导条件是MS基本培养基加入生长调节物质 2 ,4 D(4μg·L- 1 )和 6 BA(0 .2 μg·L- 1 )。叶腋等分生组织较多的部位易于诱导愈伤组织。诱导出的愈伤组织 ,经HPLC方法确定其含金丝桃素     

Mortality rates among Swedish physicians: a population-based nationwide study with special reference to anesthesiologists

BACKGROUND: Recent studies both in the UK and in the USA have indicated a higher mortality rate among anesthesiologists than among other physicians. We therefore decided to investigate the situation in Sweden during the years 1993-99. METHODS: All 26086 doctors in Sweden with a specialist licence in 1993, including those who were retired or who received one until 1999, were identified in official records and followed up regarding survival until 1999; generating approximately 179300 person-years. RESULTS: Overall, 893 deaths occurred during the 7-year follow up. Mean age at death was 72.9 years in the whole population, the lowest being 64.1 years among the anesthesiologists and the highest 77.0 among the pediatricians. However, there were large differences in the age and sex distribution among the specialties. For this reason a series of proportional hazard regression analyses (Cox's) of the mortality rates in the various specialty groups were performed, taking into account the influence of age and gender differences. After this procedure anesthesiologists had a 46% higher mortality rate and pediatricians a 24% lower mortality rate than other specialist groups; both deviations being statistically significant. All other specialties had a mortality risk within the expected range. Anesthesiologists tended to have higher rates than other specialists for most underlying causes of death. CONCLUSION: Anesthesiologists have a higher mortality rate than other specialties. The cause is so far unknown. However, it is unlikely to be caused by obvious confounders such as age, gender, or smoking habits. Other factors linked to occupational exposure should be investigated.     

IL－2对NOD鼠糖尿病的影响

ＮＯＤ鼠是人类胰岛素依赖型糖尿病的动物模型，其发病与自身免疫有关。环磷酰胺（ＣＰ）可以加速这一过程，使ＮＯＤ鼠糖尿病的发病率提高或提前。一些研究表明：ＮＯＤ鼠的淋巴细胞在淋巴细胞混合反应中（ＭＬＲ），在有或无刺激物的存在下，白细胞介素２（ＩＬ－２）的产量均明显低于正常鼠的淋巴细胞。该实验对注射了一次大剂量的ＣＰ（３００ｍｇ／ｋｇ体重）后的ＮＯＤ鼠试用了ＩＬ－２治疗。结果显示：对于年幼的ＮＯＤ鼠ＩＬ－２治疗１４无可以明显减轻注射ＣＰ后的胰岛破坏加速。病理检查显示三组胰岛炎严重程度积分分别为２９；８１；８８。ＩＬ－２处理组明显低于ＣｏｎＡ处理组与对照组。这个研究还显示，对于１２周龄的ＮＯＤ鼠，经１４天的ＩＬ－２治疗，可以完全预防ＣＰ诱导的糖尿病的发生。糖尿病发病率在ＩＬ－２组为０／１２；对照组为７／１２。但对已发病的ＮＯＤ鼠自发性糖尿病ＩＬ－２不能使其缓解。