血清亚硝酸盐的快速测定

目的：建立一种无需去蛋白的血清亚硝酸盐的快速测定方法。方法：加入蛋白活化剂后，直接用Ｇｒｉｅｓ试剂显色分光光度测定。结果：方法的检测下限为０．２μｍｏｌ／Ｌ，相对标准差为５．１３％～８．８６％，回收率为９４．５％～９９．８％（平均为９７．８％）。血清ＮＯ－２浓度为１４．３８±０．２５μｍｏｌ／Ｌ时，批内变异系数为１．７５％，ＮＯ－２浓度为５．６９±０．２５μｍｏｌ／Ｌ时，批间变异系数为４．４６％。测定５５例正常人血清，得到血清中ＮＯ－２浓度的平均值分别为５．３６±２．１６ｕｍｏｌ／Ｌ；对糖尿病病人血清测定结果表明，亚硝酸盐浓度明显高于正常人。与去蛋白的Ｇｒｉｅｓ试剂分光光度法比较，结果无统计学差异。结论：用蛋白活化剂替代蛋白沉淀剂，减少操作步骤和干扰，测定准确、简便、快速，适用于血清中ＮＯ－２的测定。     

Detection of Apoptosis in Peripheral Blood Cells of 31 Subjects Affected by Down Syndrome Before and After Zinc Therapy

Thirty-one patients affected by Down syndrome (DS) were investigated to study the presence of apoptosis in peripheral blood cells in relation to the plasma levels of zinc. Twelve patients had undergone therapy with ZnSO₄, while the remaining 19 were untreated. The presence of programmed cell death was evaluated by means of electron microscopy, in situ nick translation (NT), and agarose gel electrophoresis of DNA. These approaches evidenced the presence of apoptosis in peripheral blood cells of patients before therapy with ZnSO₄, while after zinc supplementation there was a reduction in the number of apoptotic cells. These results suggest that the process of programmed cell death in peripheral blood cells of patients with Down syndrome is related to the plasma levels of zinc ion.     

急性有机磷中毒患者的血钾变化及临床意义的探讨

目的：探讨急性有机磷中毒患的血清钾变化及其临床意义。方法：对68例发病6小时内的急性有机磷中毒的患入院后测定血清钾，并根据不同的中毒程度、中毒方式、发病时间分组在比较，并设正常对照组对照。结果：中毒各组均有明显的低钾血症，与对照组比较均有显性意义（P＜0．01）,且重度中毒组与中、轻度组比较亦有显性意义（P＞0．05），但两种不同的中毒途径与不同的中毒时间的组间血清钾的比较无显性意义（P＞0．05）。结论：急性有机磷中毒可致明显的低钾血症，中毒越重，低钾血症越明显。在发病早期应注意监测血清钾的变化，及时纠正低血钾，预防或减轻中毒后严重合并症的产生。     

常见阴离子对血清氯离子选择性电极法测定的影响

目的:研究离子选择性电极在测定血清氯时的影响因素。方法:用E-555电解质分析仪测定氟化钠、溴化钠、碳酸氢钠、硫氰化钾、碘化钾、铁氰化钾、硫化钠以及叠氮钠溶液,并将溴化钠、硫氰化钾、碘化钾、铁氰化钾、硫化钠、叠氮钠分别加入Cl~-均值为100mmol/L的混合血清中观察其具体的干扰情况。结果:所测8种物质中氟化钠、碳酸氢钠的影响较小,而溴化钠、铁氰化钾、碘化钾、铁氰化钾、硫化钠、叠氮钠的影响较大。结论:溴离子、碘离子、硫离子、氢氰根离子、叠氮钠对离子选择性电极法影响性较大,我们在工作中应加以重视。     

Special Pharmacokinetic Considerations in Children

Summary: Pediatric patients have greater degrees of pharmacokinetic variability and unpredictability than adults. This variability results from the effects of pharmacogenetics, age and growth, prior and current comedication, and disease. Newborns with seizures have the least predictable dosage requirements, and their needs change as drug-eliminating mechanisms mature in the neonatal period. Infants have the highest relative capacities to eliminate antiepileptics of any age group and require the largest relative doses. In addition to age-related trends, children demonstrate the same drug-specific, pharmacokinetic phenomena that adults do, including nonlinear phenytoin elimination, nonlinear valproate binding, and autoinduction of carbamazepine. Intercurrent illness and drug interactions further modify the age-related pharmacokinetic patterns in children and make dosage requirements even more unpredictable. Recent studies have shown that febrile illness can affect drug elimination, sometimes decreasing drug levels by 50% or more. Intermittent treatment with benzodiazepines administered either orally or rectally can be an important adjunct and help minimize this type of problem for children with marginally controlled epilepsy. Intermittent benzodiazepines are also helpful for children who have febrile seizures and who need only occasional antiepileptic protection.     

Serum digoxin and beta-methyldigoxin in elderly patients on hospital admission: correlation with home compliance and clinical variables

Summary Serum digoxin and beta-methyldigoxin (BMD) were measured in 165 elderly patients (age >60 years) admitted to hospital, of whom 109 had been treated at home with digoxin and 56 with BMD.The mean BMD level was significantly lower than that of digoxin (1.1 vs. 1.4 ng/ml). Creatinine clearance and daily dose were the variables most strongly associated with digoxin level, and the prescribed dose and serum albumin were the best predictors of the BMD concentration. Compliance was assessed by a compliance index (CI), namely the ratio of the measured glycoside concentration, corrected for creatinine clearance, over the expected steady-state dose, calculated from a hospitalized reference group. Compliant individuals in both treatment groups, i.e. those with a CI > the median value, were characterized by a lower daily dose and dosage frequency.Toxicity, whether clinical or electrocardiographic, was present in 9% of the patients and was associated only with a significantly higher mean serum level of the drug.     

The Toxic Effects of Serum from Patients with Type 1 Diabetes Mellitus on Mouse Neuroblastoma Cells: A New Mechanism for Development of Diabetic Autonomic Neuropathy

The pathogenesis of diabetic neuropathy is incompletely understood. The possibility that humoral neurotoxic factors contribute as a cause of diabetic neuropathy was tested by application of serum from patients with Type 1 and Type 2 diabetes to mouse neuroblastoma cells, which have the characteristics of adrenergic neurons in culture. Serum from patients with Type 1 diabetes and somatic neuropathy significantly inhibited both proliferation and differentiation of neuroblastoma cells, while serum from patients with Type 1 diabetes but no symptoms of neuropathy and patients with Type 2 diabetes and neuropathy had no effect on proliferation, and serum from Type 2 patients only marginally inhibited differentiation. The effects of Type 1 diabetic serum could be reversed by pre-absorption of the serum to neuroblastoma cells, and were independent of glucose levels. Immunoglobulins precipitated from the sera mimicked the effects of whole sera. These results suggest that Type 1 diabetes mellitus causes a change in serum composition, possibly related to autoimmunity, that is capable of contributing to adrenergic autonomic neuropathy in diabetic patients.     

Sex differences in plasma cocaine levels and subjective effects after acute cocaine administration in human volunteers

Gender differences after acute cocaine administration have received little attention in spite of the fact that males and females respond differently to many drugs. Seven male and seven female occasional cocaine users received both an intranasal dose of cocaine hydrochloride (0.9 mg/kg) and placebo powder in a randomized order and reported subjective effects via an instrumental joystick device and various questionnaires. Blood samples were withdrawn at 5-min intervals to assess pharmacokinetic differences. Male subjects achieved the highest peak plasma cocaine levels (144.4 ± 17.5 ng/ml), detected cocaine effects significantly faster than females and also experienced a greater number of episodes of intense good and bad effects. Women studied during the follicular phase of their menstrual cycle had peak plasma cocaine levels of 73.2 ± 9.9 ng/ml, which was significantly higher than when they were studied during their luteal phase (54.7 ± 8.7 ng/ml), but there were no differences in their subjective reports of cocaine effects. In spite of the different cocaine blood levels and subjective effects, peak heart rate increases did not differ between males and females suggesting that women may be more sensitive than males to the cardiovascular effects of cocaine. These data suggest that there are significant gender and menstrual cycle differences in the response to acute intranasal cocaine administration and these differences may have implications for the differential abuse of this drug.This paper is dedicated to Xavier Lamas, MD, PhD, who lost his life while ascending Mt. Everest, August 1995     

Oral lichenoid lesions, mercury hypersensitivity and combined hypersensitivity to mercury and other metals: histologically-proven reproduction of the reaction by patch testing with metal salts

We report 11 patients seen between 1991 and 1994 with oral lichenoid lesion(OLL). In 10 cases, there was contact with dental amalgam fillings, and in patient no. 10 with both amalgam restorations and a gold crown. The last patient had, in addition to her OLL, lichen planus of the skin and genital mucosa. In 5 cases, combined sensitization to mercury and other metal salts, particularly gold sodium thiosulfate (GST) and palladium chloride (PDC), was observed. In 10 patients, the lesions considerably improved or totally cleared within 1 to 9 months of replacement of restoration materials. Histological examination of biopsies from the test sites of amalgam, mercuric chloride, GST and PDC, taken 10 or 17 days, after application of patch tests, showed lichenoid changes in 7 patients with at least 1 of the allergens. At least 2 patients had inflammatory lesions of the oral mucosa related to both amalgam and gold restorations, combined sensitization to inorganic and organic mercury derivatives. GST and, in 1 case, PDC, a "dental restoration metal intolerance syndrome" is proposed.     

Serum modulates cyclic AMP-dependent morphological changes in cultured neurohypophysial astrocytes

The effects of serum on the morphological plasticity exhibited by pituicytes in explant cultures of the neurohypophysis of adult rats have been examined. Cultured pituicytes are normally nonstellate, protoplasmic, amorphous cells (< 25% are stellate with a distinct cell body and phase bright processes). After incubation (90 min) of pituicyte cultures in a HEPES buffered salt solution (HBSS) supplemented with isoproterenol or forskolin, the fraction of stellate pituicytes significantly increased. The increase in the fraction of stellate cells induced by isoproterenol was not reversed by subsequent incubation in isoproterenol-free HBSS for 90 min. In contrast, after stellation was induced in cultures by exposure to forskolin (90 min), the fraction of stellate cells was significantly reduced if these cultures were incubated in forskolin-free, serum (0.5%) supplemented HBSS for the same duration. Serum also blocked the increase in the fraction of stellate pituicytes induced by forskolin. These experiments suggest that serum components may have a significant role in controlling the plasticity of neuroglial relations in the neurohypophysis priviously demonstrated in vivo.