Vitamin supplementation of patients receiving haemodialysis

In order to assess the necessity of vitamin supplementation for patients who are receiving haemodialysis, measurements of vitamin status were made, and both dietary and supplementary intakes were assessed, in 26 patients who were undergoing haemodialysis. Blood samples were collected from these patients before they underwent haemodialysis, after an overnight fast, for the measurement of plasma retinol, alpha-tocopherol and ascorbate levels. Serum and erythrocyte folate levels were measured also. Thiamin status was assessed by the effect of added thiamin pyrophosphate on erythrocyte transketolase activity and pyridoxine status was assessed by the effect of added pyridoxal-5'-phosphate on erythrocyte aminotransferase activity. All patients had elevated plasma retinol levels; 48% of patients had elevated plasma alpha-tocopherol levels; the plasma ascorbate level was low in 50% of patients but was elevated in 25% of patients; and plasma and erythrocyte folate levels were elevated in 76% and 91% of patients, respectively. Thiamin status was normal in all but one patient and the pyridoxine level appeared to be low in two other patients. Many patients had low dietary intakes of vitamin C, folate and vitamin B6. We conclude that supplements of vitamins A and E are not required and, when dietary intakes of water-soluble vitamins are marginal, these should be supplemented at a dose as near as possible to the recommended dietary intake.     

Moclobemide pharmacokinetics in depressed patients: Lack of age effect

The pharmacokinetics of moclobemide were examined in 19 depressed patients following a single oral dose of 50 mg. Ten patients were aged >60 years and nine <59 years. Plasma concentrations were analysed by gas chromatography with nitrogen-specific detection. Pharmacokinetic parameters calculated were peak concentration, time to reach the peak, terminal disposition half-life, area under the curve, oral clearance and apparent volume of distribution. No clinically significant differences were found betwen the two patient groups for these parameters. Thus there is no requirement for dosage adjustment in the older patient for moclobemide. This contrasts with some tricyclic and tetracyclic antidepressants which show significant age effects. Further studies of moclobemide for the treatment of elderly depression are warranted.     

雪灵芝对二乙基亚硝胺诱导大鼠肝癌组织细胞的抑制作用

目的：验证雪灵芝是否具有抑制大鼠肝癌的功效。方法：实验于2003—09/2004—08在广西疾病预防控制中心SPF级动物实验室完成。选用健康成年SD大鼠160只。按体质量分层随机分为5组：空白对照组、模型组、雪灵芝高剂量组、雪灵芝中剂量组和雪灵芝低剂量组，每组32只。雪灵芝高、中、低剂量组大鼠分别灌胃2．500，1．250，0．625mL/kg雪灵芝溶液，阴性对照组和模型组灌胃等量蒸馏水，1次／d，连续60d。第61天开始雪灵芝高、中、低剂量组和模型组灌胃二乙基亚硝胺溶液，对照组灌胃等量的生理盐水。于停止灌胃90d后各组处死一半受试大鼠（雌雄各半），检测血常规及血清主要生化指标，观察各脏器大体形态改变、脏器的癌变程度。1周后给剩余大鼠灌胃雪灵芝溶液（不含二乙基亚硝胺）。7周后处死余下的一半雄性大鼠，进行相同操作。8周后处死余下的全部大鼠，操作及检测方法同前。结果：纳入的160只SD大鼠，145只进入结果分析，15只脱落。①病理切片检查结果：除阴性对照组，其他各组大鼠肝组织均发生癌变或癌前病变。雪灵芝高、中、低剂量组的癌前病变发生率与模型组相近（P〉0．05）；癌变的发生率均低于模型组，差异有显著性意义（P〈0．05，0．01）。②大体标本检查结果：阴性对照组大鼠肝脏的大体标本均无异常改变，其他各组大鼠的肝脏有些可见表面粗糙等病理改变。模型组大体标本病理改变的阳性率高于雪灵芝高、中、低剂量组，差异有显著性意义（P〈0．05）。肉眼观模型组癌变发生率高于其他各组。③其他脏器检查结果：模型组2只大鼠有肝癌肺转移。结论：以较大剂量的二乙基亚硝胺连续灌胃30d可以复制大鼠肝癌模型；雪灵芝对二乙基亚硝胺诱导的大鼠肝癌具有预防和抑制的作用。     

The Initiating Dialysis Early and Late (IDEAL) study: study rationale and design.

OBJECTIVES: The primary objective of the IDEAL study is to determine whether the timing of dialysis initiation has an effect on survival in subjects with end-stage renal disease (ESRD). The secondary objectives are to determine the impact of "early start" versus "late start" dialysis on nutritional and cardiac morbidity, quality of life, and economic cost. DESIGN: Prospective multicenter randomized controlled trial. Patients are randomized to commence dialysis at a glomerular filtration rate (by Cockcroft-Gault) of either 10-14 mL/minute/1.73 m2 ("early start") or 5-7 mL/min/1.73 m2 ("late start"), with stratification for dialysis modality (hemodialysis vs peritoneal dialysis), study center, and the presence or not of diabetes mellitus. SETTING: Dialysis units throughout Australia and New Zealand. PATIENTS: Patients with ESRD commencing chronic dialysis therapy. OUTCOME MEASURES: Three years from randomization, all-cause mortality, morbidity, and economic impact; structural and functional cardiac status, nutritional state, and quality of life will be assessed. RESULTS: To date, 388 patients of a minimum 800 patients have been entered and randomized into the study. Current recruitment rates suggest sufficient patients will be enrolled by December 2004 and follow-up completed by December 2007. CONCLUSIONS: The IDEAL study will provide evidence for the optimal time to commence dialysis.     

A novel selective positive allosteric modulator of metabotropic glutamate receptor subtype 5 has in vivo activity and antipsychotic-like effects in rat behavioral models

We found that 3-cyano-N-(1,3-diphenyl-1H-pyrazol-5-yl)benzamide (CDPPB) is a potent and selective positive allosteric modulator of the metabotropic glutamate receptor subtype 5 (mGluR5). In Chinese hamster ovary cells expressing human mGluR5, CDPPB potentiated threshold responses to glutamate in fluorometric Ca2+ assays more than 7-fold with an EC50 value of approximately 27 nM. At 1 microM, CDPPB shifted mGluR5 agonist concentration response curves to glutamate, quisqualate, and (R,S)-3,5-dihydroxyphenylglycine 3- to 9-fold to the left. At higher concentrations, CDPPB exhibited agonist-like activity on cells expressing mGluR5. No other activity was observed on any other mGluR or cell type at concentrations up to 10 microM. CDPPB had no effect on [3H]quisqualate binding to mGluR5 but did compete for binding of [3H]methoxyPEPy, an analog of the selective mGluR5 negative allosteric modulator MPEP. CDPPB was found to be brain penetrant and reversed amphetamine-induced locomotor activity and amphetamine-induced deficits in prepulse inhibition in rats, two models sensitive to antipsychotic drug treatment. These results demonstrate that positive allosteric modulation of mGluR5 produces behavioral effects, suggesting that such modulation serves as a viable approach to increasing mGluR5 activity in vivo. These effects are consistent with the hypothesis that allosteric potentiation of mGluR5 may provide a novel approach for development of antipsychotic agents.     

Thallium poisoning: an outbreak in Florida, 1988.

In October 1988, five of seven members of a Florida family were poisoned with thallium, constituting the largest outbreak of acute thallium poisoning in the United States since thallium was banned as a rodenticide in 1972. Three patients had an acute severe neuropathy with respiratory depression; one died. The other two had no symptoms. No cases were identified among nonhousehold relatives or friends, or in the community. Of the more than 100 environmental specimens collected at the family household and tested by atomic spectroscopy, three empty and four unopened glass soft drink bottles of the same lot number yielded thallium in a concentration fatal to humans. All family members who consumed the soft drink were poisoned (5/5) as compared with none of those who did not (0/2). Because poisoning was clustered to the family and police investigators provided evidence that the poisoning was deliberately targeted to the family, it was assumed that no other soft drink bottles contained thallium, and it was decided not to recall all soft drink bottles with the same lot number. A year later a neighbor of the family was arrested and convicted of the murder.     

Polymorphisms in the β2-adrenoreceptor gene are associated with decreased airway responsiveness

BACKGROUND: There are a number of candidate genes thought to play a role in the development of asthma. Polymorphisms at amino acid positions 16 (arginine to glycine) and 27 (glutamine to glutamic acid) of the beta2-adrenoreceptor (B2AR) gene are known to be functionally relevant and have been associated with more severe forms of asthma, nocturnal asthma and decreased airway responsiveness in asthmatic subjects. OBJECTIVE: To determine if these polymorphisms contribute to the development of asthma by investigating the associations between the polymorphisms at amino acid positions 16 and 27 of the B2AR gene and asthma-related parameters in a large, phenotypically well-characterized population which was unselected for asthma. METHODS: Subjects (n = 332) were characterized using physiological assessments, immuno-logical data and information obtained from questionnaire. PCR was used to generate a 229 base pair fragment spanning the mutations of interest. Genotype was determined using allele-specific oligonucleotide hybridization and confirmed in 10% of the samples by direct sequencing. Multivariate analysis of the association between genotype and phenotype was then undertaken. RESULTS: Homozygotes for Glu27 were significantly less responsive to histamine than Gln27 homozygotes. In addition, Arg16 homozygotes were more likely to 'wheeze during a cold', in comparison with Gly16 homozygotes. However, there was no association between either polymorphism and physician-diagnosed asthma, eczema, skin reactivity to common allergens or total and specific serum IgE levels. The two polymorphisms were found to be in significant linkage disequilibrium. CONCLUSION: The polymorphism at position 27 was associated with decreased airway responsiveness in the study population and the polymorphism at position 16 was associated with increased wheeze during respiratory infection, but neither was associated with physician-diagnosed asthma or any of the other variables considered.