Physiology of cold-stored platelets

Platelet transfusions are a life-saving medical intervention used for the treatment of thrombocytopenia or hemorrhage. Extensive research has gone into trying to understand how to store platelets prior to the transfusion event. Much has been learned about storage bag materials, synthetic solutions, and how temperature impacts platelet viability and function. While room temperature storage of platelets preserves 24-hour in vivo platelet recovery and survival there is a greater risk for bacterial growth. Therefore, cold storage of platelets has become attractive due to the reduction in potential bacterial proliferation and the maintenance of platelet function beyond 5 days of storage. Cold stored platelets, however, have their own set of challenges. Cold stored platelets become activated through several mechanisms. The morphological and molecular changes that occur due to cold exposure enhance their ability to participate in the hemostatic process at the cost of rapid clearance from circulation. This review focuses on the underlying mechanisms leading to cold platelet activation and the receptor modifications involved in platelet clearance.     

Ten-year stability of cardiovascular responses to laboratory stressors

In this study we examined test-retest stability of cardiovascular stress responses over a decade of the life span. Participants were 55 male college undergraduates. 19 years of age at initial testing, and 29 years of age at follow-up testing Stressors were a foot cold pressor and an aversive reaction time task. Cardiovascular measures included systolic and diastolic blood pressure, heart rate, and preejection period. For cold pressor, the magnitude and pattern of cardiovascular responses remained unchanged at the 10-year follow-up. For the reaction time task, the characteristic cardiovascular response patterns was preserved but with significant attenuation of magnitude. The present findings are consistent with previous observations of temporal stability but over a substantially longer test-retest interval. The long-term stability of stress responses is discussed in the context of stress test methodology, behavioral response demands, and maturation of the physiological systems involved in cardiovascular response expression.     

冷哮丸对动物祛痰作用的影响

目的：探讨冷哮丸对动物的祛痰作用及其作用机制。方法：采用酚红法和毛细玻管法测定排痰量，用家鸽活体气管法及兔离体气管法测其纤毛运动。结果：冷哮丸能显增加小鼠气管酚红排泌量，增加大鼠排痰作用，增强在体鸽及离体兔气管纤毛运动。结论：冷哮丸有显的祛痰作用，其机理可能是增加气管内浆液成分，痰液变稀，同时加快气管纤毛运动而达到祛痰目的。     

冷保存对大鼠部分移植肝再生的影响

目的探讨冷保存对大鼠部分肝移植术后肝再生的影响。方法健康SD大鼠分为Ⅰ组（肝切除组）、Ⅱ组（冷保存1h部分肝移植组）和Ⅲ组（冷保存8h部分肝移植组）。观察各实验组生存率，比较各组术后1、6、12、24、48、72、168h肝质量／体质量比率、肝再生率、有丝分裂指数及增殖细胞核抗原表达。结果Ⅰ、Ⅱ、Ⅲ组7d存活率分别为100％、90％、40％；Ⅲ组术后2～3d大鼠肝质量／体质量比率、肝再生率、有丝分裂指数较Ⅰ、Ⅱ组明显偏低（P〈0．05）；Ⅲ组术后12h内增殖细胞核抗原表达较其余两组明显偏低（P〈0．05），48h才达高峰，至第7天阳性表达仍处高水平。结论长时间冷保存降低了部分肝移植术后的肝再生能力和大鼠术后生存率。     

Prevalence of vibration-induced white finger and assessment of vibration exposure among travertine workers in Italy

Summary Among 76 stonedrillers and stonecutters/chippers working in the Rapolano travertine quarries (Tuscany, Italy), 27 subjects (35.5%) were affected with vibration-induced white finger (VWF). The median latent period for VWF was ten years (range 0.1–26 years). A VWF prevalence of 8% was found among 60 comparable controls (P < 0.0001). Vibration measurements showed that the frequency-weighted accelerations for two rock-drills and two small chipping hammers ranged from 19.7 to 36.4 m/s². Weighted accelerations between 2.4 and 4.1 m/s². were measured on the handles of a vertical grinder and a hand cutter. Vibration data, daily exposure time and total duration of exposure period were used to calculate two indicators of vibration dose such as the four-hour, energy-equivalent, frequency-weighted acceleration (m/s²) and the vibration exposure level (dB). A significant association between the vibration exposure level and the severity of VWF stages was observed among the travertine operators. The dose-effect relationship proposed by ISO 5349 was not suitable for the data of the present study because it overestimates the risk due to hand-transmitted vibration in the travertine workers. Finally, the results of a cold test indicated that the rewarming time of fingertips to room temperature was more prolonged in the operators with VAT than in those without VWF and in the controls.     

山西省计划免疫冷链设备现状调查

为了解山西省计划免疫冷链设备现状,于2001年5月对全省各级卫生防疫站进行了调查.结果显示截止调查时全省装备的6种主要冷链设备共4419台(件,下同),其中前10年(1986～1995年)装备2489台,占56.3%;后6年(1996～2001年)装备1930台,占43.7%.在4419台中,当前正常运转的1930台(43.7%),尚可使用的1057台(23.9%),损坏报废的1432台(32.4%).为满足当前需要,全省尚需增补1888台,其中县、乡两级需增补普通冰箱1011台,低温冰箱805台,疫苗运输车35辆;省、市两级需增补普通冷库4台,低温冷库10台,冷藏车9辆,疫苗运输车14辆.说明需增补的重点在基层.     

地塞米松对冷藏离体肺表面活性物质和顺应性的影响

目的:观察地塞米松对冷藏离体肺表面活性物质和顺应性的影响.方法:32只家兔肺随机均分为对照组、地塞米松冷藏(4℃)保存24h、72h、120h3个组.对照组:测定室温条件下的肺表面活性物质及顺应性.冷藏组:肺离体后立即置于含有地塞米松台式液中冷藏,在相应时间取出肺,室温条件下复温后,置入生理盐水中,测定肺表面活性物质,并测定注气(生理盐水)和抽气(生理盐水)过程中,肺容积在10ml、20ml、30ml时的肺顺应性.结果:冷藏24h组注水、抽水;72h组肺容积在10ml、20ml抽气、冷藏120h组在肺容积为10ml、20ml抽气的肺顺应性同对照组比较,差异无显著性(P>0.05).其余各组、项与对照组比较差异具有显著性(P<0.05),伴有表面活性物质的减少.结论:地塞米松冷藏离体肺顺应性增大,其影响程度随冷藏时间的延长而增加,同时伴有肺表面活性物质的减少.     

实验冻伤大鼠神经纤维的超微结构改变

为探讨冷冻损伤发生、发展及转归的规律，采用健康Ｗｉｓｔａｒ大鼠，分为冻伤组（２０只）和对照组（５只）。电镜下观察大鼠后肢冷冻至－２０℃后即刻、４小时、２４小时及７２小时时周围神经的超微结构改变。冻后即刻，神经髓鞘即出现轻度变性；冻后１～２４小时，有髓神经雪旺细胞及轴突严重变性，而无髓神经变性较轻；冻后７２小时，神经溃变及修复并存，无髓神经较有髓神经易于修复。     

The cold pressor test: Vascular and myocardial response patterns and their stability

The purposes of the present study were to compare the cardiovascular response patterns evoked by three versions of the cold pressor test (either forehead stimulation or hand or foot immersion) and to determine the reproducibility of the responses over a 2-week interval. Blood pressure, heart rate, stroke volume, cardiac output, total peripheral resistance, and systolic time intervals were obtained during rest and during the cold pressor test in 42 young men. Across conditions, the pressor response was supported by peripheral resistance increases with concomitant stroke volume decreases. Although the response panerns were generally similar across sites, exceptions were apparent for heart rate. Forehead stimulation was characterized by no significant change in heart rate, whereas limb (hand or foot) immersion was associated with significant heart rate acceleration. The responses elicited by the three cold pressor test conditions were reliable and showed little evidence of attenuation over the test-retest interval.     

自身免疫性溶血性贫血20例临床分析

本文报道温抗体型自身免疫性溶血性贫血20例,其中包括特殊类型“兼有冷抗体和温抗体的自身免疫性溶血性贫血”3例,伴有血小板减少性紫瘢的Fisher—Evans综合征4例。并对本病致病因素、发病年龄、临床表现及特殊类型产生机理进行了讨论。