Plasma Norharman (β-Carboline) Levels are Elevated in Chronic Alcoholics

Based on the hypothesis that condensation products of neurotransmitters with aldehydes are involved in the pathogenesis of alcoholism, aromatic beta-carbolines (norharman and harman) were measured in the blood plasma of alcoholics and nonalcoholics. The identity of the extracted compounds was confirmed by various elution conditions of the high performance liquid chromatography (HPLC), newly developed radioreceptor assays, and the mass spectrum of norharman. The levels of norharman and harman in nonalcoholics were unchanged after a load with ethanol (1 g/kg body weight). The norharman levels of the alcoholics were significantly higher than that of the nonalcoholic controls (99.5 +/- 26.6 pg/ml vs. 26.9 +/- 10.7 pg/ml; p less than 0.001) and did not change significantly during a 3-week detoxication period. In the subgroup of alcoholics with delirium or hallucinosis, a slight increase of norharman during detoxication could be detected while in alcoholics with vegetative withdrawal symptoms norharman levels dropped slightly over time (p = 0.07). No difference was found with respect to harman between nonalcoholics and alcoholics. These results suggest disturbed regulatory processes in the formation and/or metabolism of norharman in alcoholics. Further investigations are needed to reveal a possible marker function of norharman in alcoholic patients.     

Pharmacokinetics of orally administered hexobarbital in plasma and saliva of healthy subjects

Hexobarbital (HB) concentrations were determined in plasma and saliva of 8 healthy subjects, following oral administration of 500 mg HB-Na. Mean plasma half-lives were 3.2 +/- 0.1 h, and salivary half-lives 3.3 +/- 0.2 h. Mean plasma clearance was 22.9 +/- 2.3 1 h-1. There was a linear relationship between HB concentrations in saliva and plasma (r = 0.92). Mean salivary levels were 34 per cent of plasma levels. Salivary pH was constant throughout the experiment, 7.06 +/- 0.09. There was an inconsistent tendency of the saliva over plasma ratios to increase as a function of time. The percentage of protein binding calculated from saliva over plasma ratios was in reasonable agreement with in vitro data of equilibrium dialysis, 64.1 +/- 2.6 per cent and 65.9 +/- 0.8 per cent, respectively. The experiment was repeated in 4 subjects, and considerable intraindividual differences were shown to exist in saliva over plasma ratio, half-lives, and protein binding. It was concluded that HB elimination half-lives can relatively accurately be determined from salivary concentrations. Oral plasma clearance can only be estimated if the individual saliva over plasma ratios are known; this would require the taking of at least one blood sample during the experiment. When employing HB as a model substrate for drug metabolizing enzyme activity in vivo, the determination of its pharmacokinetic parameters, particularly oral plasma clearance as a reflection of cytochrome P-450 activity, cannot be achieved by taking saliva samples only.     

N-(Acyloxyalkoxycarbonyl) derivatives as potential prodrugs of amines. II. esterase-catalysed release of parent amines from model prodrugs

N-(Acetoxyethoxycarbonyl) derivatives of primary amines released a major fraction of the parent amine in the desired free form in plasma but a significant fraction of the undesired N-acetylated parent amine was also produced. The fraction of the parent amines released from the carbamate derivatives of the primary amines was greater in human plasma than in pH 7.4 buffer. In human plasma, the N-(acetoxyethoxycarbonyl) derivative of a secondary amine released the parent amine in a quantitative manner at a rate higher than that observed in pH 7.4 buffer. Experimental results suggested that the observed catalysis of the release of the parent amines from N-(acetoxyethoxycarbonyl) derivatives of primary and secondary amines was due to participation by plasma esterases. The data suggested that N-(acetoxyethoxycarbonyl) derivatives are well suited for use as prodrugs of secondary amines. Their utility as prodrugs of primary amines is more problematic and cannot be predicted prior to in-vivo studies for the individual compound.     

老年人高粘滞血症预防的初步探讨

本文报告对32例60岁以上健康老年人预防高粘滞血症的观察结果.经采取综合预防措施六年,血流变学检测表明:全血(比)粘度、血浆(比)粘度、血沉、红细胞压积均低于对照组,统计学处理表明,前三项指标P值均小于0.01,因此达到了对老年人高粘滞血症的预防目的.     

血浆置换治疗移植肾复发性FSGS合并大量蛋白尿的远期观察

目的 探讨血浆置换治疗移植肾复发性局灶性节段性肾小球硬化（FSGS）效果及其对远期预后的影响。方法 6例患者首次肾移植后出现大量蛋白尿或／和血肌酐（Cr）升高、并经移植肾活检确诊为FSGS，在不改变免疫抑制方案的情况下，采用血浆置换治疗，观察血浆置换后1年移植肾的病理改变情况，测定血肌酐和24h尿蛋白定量。结果 6例患者中，2例在血浆置换后1年接近完全缓解，4例部分缓解。患者血浆置换后1年，移植肾的肾小球、肾间质、血管及免疫球蛋白病变的等级与血浆置换前相比，差异均无统计学意义。血浆置换后1年及5年的Cr水平与血浆置换前相比，差异均无统计学意义；24h尿蛋白定量与血浆置换前相比，差异均有统计学意义（P〈0．01，P〈0．05）。结论 血浆置换能快速、有效地缓解移植肾复发性FSGS的病变程度和进程，其效果取决于FSGS诊断的及时性，如果已发展到肾小球硬化的程度，血浆置换亦无法将其逆转。     

Regulation of fluid intake in dogs following water deprivation

Whereas water loss in land living animals occurs continuously, water intake takes place discontinuously. At the normal operating set point of plasma osmolality, urine is more concentrated than plasma due to secretion of vasopressin. Thus animals operate around a state of mild dehydration. As water loss occurs, the severity of dehydration and thirst increase in intensity and at some point water intake occurs. Sufficient water is consumed to return plasma osmolality to the normal operating set point. Food intake and water balance are interdependent as food provides the osmoles which determine obligatory renal solute excretion. When dry food with the same osmotic content was substituted for canned food (water content 74%), dogs increased water intake from 24.2 +/- 4.3 to 62.2 +/- 8.8 ml/kg. Urine output and urine osmolality were unchanged, as under conditions of normal hydration, near maximal urine concentration is achieved. Changing water intake is the only available variable to maintain water balance. During water deprivation, the major renal mechanism appears to be natriuresis. In rehydration, satiety mechanisms ensure appropriate water intake and renal sodium conservation restores sodium balance.     

成分输血在临床中的应用

成分输血是现代输血学的重要标志之一。临床医生要了解成分输血的知识,遵循科学用血、合理用血、节约用血的原则,根据病情有针对性地开展成分输血。成分输血的重点,应当是血液的有形成分,即以红细胞和血小板为主的成分输血。本文就成分输血的特点与临床应用等有关问题进行综述。     

健康儿童血浆游离氨基酸与体格生长的研究

本文采用丹酰氯聚酰胺薄层分析法研究了65名3～7岁健康儿童的血浆游离氨基酸,研究其与体格生长的关系.结果表明:赖氨酸,甘氨酸,羟脯氨酸,与年龄别身高、体重和身高别体重百分位成正相关.并有显著意义.异亮氨酸.赖氨酸.甘氨酸在营养优组中显著高于差组.提示血浆游离氨基酸对健康学龄前儿童的体格生长发挥重要的生理作用.     

多器官功能衰竭患儿血糖血乳酸血渗透压的改变

对５０例ＭＯＦ患儿血糖血乳酸血渗透压进行了检测，并与３５名健康儿童进行比较。结果显示危重患儿血糖血乳酸明显高于对照组，血糖血乳酸呈正相关，提示高血糖是危重患儿应激状态下的主要代谢改变。当患儿血糖＞１５ｍｍｏｌ／Ｌ血乳酸）５ｍｍｏｌ／Ｌ时，其死亡率明显增加，因此血糖血乳酸的变化可作为ＰＩＣＵ的常规监测指标。     

血浆置换治疗97例重型肝炎并发症的防治

目的探讨血浆置换治疗重型肝炎时并发症的发生原因及防治措施。方法回顾血浆置换治疗97例重型肝炎时出现的并发症的有关资料，分析各种并发症发生的原因。结果26．6次治疗中共出现并发症131次，发生率达49.3％。按发生率高低依次为皮疹、麻木和（或）搐搦、血压下降、胸闷、失衡综合征、置管处渗血、体外循环凝血及置管处渗液。结论血浆置换治疗重型肝炎时并发症的发生率高，但经处理均能缓解，可以在严密监护下实施。