ITP患者T细胞对巨核细胞生成作用的影响

本文应用改良的血浆凝块技术和共培养系统研究特发性血小板减少性紫癜(ITP)患者T细胞在体外对异体骨髓巨核细胞生成作用的影响,以探讨ITP的发病机制。实验结果表明,从总体来看,ITP患者的T细胞当加到培养物中和靶细胞共培养时,对巨核系祖细胞集落形成单位(CFU-MK)的集落效应无明显的影响。其中三例PAIgG升高患者的T细胞对CFU-MK有不同程度的抑制作用。以上结果提示ITP的发病机制相当复杂。除体液免疫机制外,也有细胞免疫机制参与,T细胞或其亚群对巨核系祖细胞生成抑制在ITP的发病机制中可能起着一定的作用。     

耐热锻炼对人体热暴露时血浆丙二醛和中分子物质含量的影响

本文报告热习服对血浆丙二醛和中分子物质含量的影响。15名健康男子,平均年龄21.8±0.7岁,于平均气温27.3±1.2℃负重行军90min,2周内共锻炼11次(天)。标准热暴露试验对比表明获得了热习服,肛温和心率增值大大降低(P<0.01和P<0.05)。锻炼期前、后标准试验时血浆丙二醛含量降幅分别为29.4%(P<0.01)和30.1%(P<0.01),而中分子物质含量增幅分别为6.3%(P<0.05)和9.2%(P<0.01)。热前、后血浆丙二醛含量较锻炼期前仅分别降低5.5和6.5%(P>0.05),而中分子物质含量分别降低18.3和16.1%(P<0.01),可见,热习服后血浆丙二醛和中分子物质含量没有同步降低。     

肥胖患者胰升糖素水平变化及其对空腹血糖的影响

目的　探讨肥胖患者胰升糖素的变化特点及其对血糖的影响。方法　将 82例患者根据体重指数分为 3组 :A组 (BMI <2 4,n =2 3 )、B组 (2 4≤BMI <2 7,n =2 7)、C组 (BMI≥ 2 7,n =3 2 ) ,分别测定胰升糖素、胰岛素、空腹血糖 ,采用单因素方差分析法与Spearman等级相关性分析法进行分析。结果　 3组胰升糖素分别为 (15 6.3± 5 8.6)、(186.7± 67.5 )、(2 2 2 .2± 88.4)ng·L-1,C组与A组比较有显著性差异 (P <0 .0 1) ;3组胰岛素分别为 (15 .4± 4.7)mIU·L-1、(2 0 .6± 9.6)mIU·L-1、(2 2 .3± 10 .6)mIU·L-1,B组、C组与A组比较差异有显著意义 (P <0 .0 5、P <0 .0 1) ;B、C两组胰升糖素与空腹血糖呈正相关。结论　肥胖患者胰岛素、胰升糖素一致性增高 ,胰升糖素的增高是空腹血糖增高的重要因素。     

Factors related to renal haemodynamics in young type-1 diabetes mellitus patients

The influence of metabolic control (HbA_1c), noradrenaline (NA) and insulin-like growth factors (IGF-I and IGF-II) on renal function and size was investigated in 11 insulin-dependent diabetes mellitus patients aged 11–17 years. Renal function was evaluated in terms of glomerular filtration rate (GFR) and effective renal plasma flow (ERPF). Renal size was determined as renal parenchymal volume (RPV) by ultrasonography. The patients' HbA_1c values ranged from 8.2% to 12.9% (normal range 5.5–8.5%) and their GFR and ERPF were higher than normal. Their IGF-II values were higher, and NA and IGF-I levels were lower than those of healthy controls. Inverse correlations between NA and GFR (r=–0.66) and NA and ERPF (r=–0.63) were found. No correlation was found between serum IGF-I and renal functional parameters. The IGF-II values correlated with GFR and HbA_1c (r=0.63,r=0.70 respectively). There were linear correlations between RPV and GFR, RPV and ERPF, HbA_1c and GFR, and ERPF and RPV. Decreased NA concentrations and increased IGF-II values appear to be factors contributing to renal hyperfunction in these patients.     

A guar-enriched wholemeal bread reduces postprandial glucose and insulin responses

We have developed a guar wholemeal bread and tested its physiological efficacy and sensory qualities. The objective of the study was to estimate the optimum concentration of guar in bread required to reduce postprandial glycaemia and insulinaemia without adversely affecting the quality of the bread. Following overnight fasts, 15 normal weight, non-diabetic subjects consumed meals of wholemeal bread alone (controls) and supplemented with guar at three different concentrations (5, 10 and 15% replacement of wheat flour). Blood samples for glucose and insulin analysis were taken preprandially, and at 30 and 60 min after the start of each meal. The acceptability of the wholemeal control and guar breads was assessed using a hedonic scaling method. A significantly lower blood glucose rise at 30 min was found after the 15% guar bread meal compared to the control. Plasma insulin responses at 30 and 60 min were significantly lower after the 10 and 15% guar bread meals compared to the controls. Hedonic scores indicated that the subjects found the 5 and 10% guar breads acceptable and in the case of the 5% variety the mean score was identical to the control. We suggest that a guar concentration of between 5 and 10% replacement of wheat flour (wholemeal or white) should be used for the baking of guar wholemeal bread but further work is needed to define the precise quantity of guar required.     

抗—HCV阳性单采浆供血员HGV感染随访研究

为了解单采浆供血员庚型肝炎病毒（ＨＧＶ）感染及其转归，对１０２名抗－ＨＣＶ阳性单采浆供血员冻存血清进行抗－ＨＧＶ和ＨＧＶＲＮＡ检测，对抗－ＨＧＶ和（或）ＨＧＶＲＮＡ阳性者作３年随访研究。采用ＥＩＡ法检测抗－ＨＧＶ，包被抗原来自ＨＧＶ不同功能区的合成肽。应用ＲＴ－ＰＣＲ法检测ＨＧＶＲＮＡ，引物选自ＨＧＶＮＳ３区。结果表明，抗－ＨＣＶ阳性单采浆供血员ＨＧＶＲＮＡ阳性率为１９．６１％（２０／１０２），抗－ＨＧＶ阳性率为１７．６５％（１８／１０２），ＨＧＶ感染率（抗ＨＧＶ和／或ＨＧＶＲＮＡ阳性）为２４．５１％（２５／１０２），而对照组仅为０．９４％（１／１０６）。提示单采血浆是ＨＧＶ感染的重要危险因素。ＨＧＶＲＮＡ和抗－ＨＧＶ的３年阴转率分别为３５．００％（７／２０）和１１．１１％（２／１８），说明ＨＧＶ感染有慢性携带趋势     

Matching blood donations to type-specific product needs: A recruitment technique

The conversion of multiple whole blood donors to apheresis donors is a challenge since a rapidly expanding apheresis donor base could erode homologous collections. We addressed this concern with a plan to enhance apheresis recruitment as well as donations among homologous donors with types O and B blood. Focusing the donor's attention on blood type as it relates to type-specific product needs was the basis of our approach. A matrix was used to recruit the desired types for the desired procedures (whole blood, platelet/plasma apheresis). The matrix instructed donors of blood types O, A-, and B- to primarily give whole blood and to give apheresis as a secondary donation. Donors AB, A+, and B+ were primarily directed to apheresis donations, whole blood donation being secondary. A+ and O- donors only gave their secondary donation if they were at maximum donations with the primary donation. The collections by blood type in percentages for 12 months of 1992/93 for whole blood were O+ 38.9, 0- 7.3, A+ 29.5, A- 5.7, B+ 11.9, B- 2.1, AB+ 3.7, AB+ 0.7. For apheresis it was 0+ 36.2, 0- 6.7, A+ 33.0, A- 6.6, B+ 10.4, B- 1.2, AB+ 4.9, AB+ 1.0. In 1992/93, A+ and B+ apheresis collections as compared to total apheresis collections increased by 4.9% and 13.7%, respectively. For O group apheresis donations, a decrease of 2.5% was shown and A+ whole blood donations decreased by 5.35%. During the same period of time, total apheresis collections increased by 3,058 units. We demonstrated that integration of apheresis recruitment with type-specific whole blood recruitment yielded significant increases of type-specific products.     

Effects of intravenous L-acetylcarnitine on retinal oscillatory potentials

L-acetylcarnitine is a compound with cholinergic properties and putative action on the visual system and the glucose metabolism. Ten healthy, emmertropic volunteers (age range: 21 to 28 years) were studied. Each subject was administered 5, 10, and 30 mg/kg acute intravenous doses of L-acetylcarnitine and matching placebo. Retinal oscillatory potentials to full-field flash stimulation were recorded before and 30, 60, and 120 min after administration. A systematic reduction of the implicit time of the P2 and N2 oscillatory potential components was observed after administration of the 10 and 30 mg/kg doses: significant changes were not evident at the 5 mg dose or after placebo. The latency reduction was significantly correlated with the postdrug increment of the L-acetylcarnitine plasma concentration. No other systematic modification in latency of amplitude was observed.The results were presented in part at the XXV I.S.C.E.V. Symposium, Sarasota (Florida), April 26–30, 1987.     

Pharmacokinetics and haemodynamic effects of ISDN following different dosage forms and routes of administration

The pharmacokinetics and haemodynamic effects of isosorbide dinitrate (ISDN) have been investigated following administration of single doses as a sublingual (SL) spray (2.5 mg), sublingual tablet (5 mg) and peroral tablet (10 mg) in a randomised, placebo-controlled double-blind cross-over trial in 16 healthy volunteers.After the sublingual spray C_max was higher (39.0 ng·ml^-1) and t_max was shorter (3.9 min) than after the sublingual (22.8 ng·ml^-1 and 13.8 min) and peroral (16.9 ng·ml^-1 and 25.6 min) tablets. The AUC of ISDN did not differ following any of the three formulations (1031; 879; 997 ng·ml^-1·min, for the spray, SL tablet and PO-tablet, respectively). Mononitrate metabolites of ISDN (IS-2-MN and IS-5-MN) and total nitrates in plasma increased in proportion to the administered dose. This indicates that the fraction of the dose absorbed was the same for all the formulations but that the extent of first-pass metabolism increased in the order sublingual spray < sublingual tablet < peroral tablet. Thus, compared to the spray, the relative bioavailability of ISDN was 48% and 28% from the sublingual and peroral tablets, respectively.The haemodynamic effects were quantified using the a/b ratio of the finger pulse wave and the systolic blood pressure and heart rate under orthostatic conditions. For the a/b ratio of the finger pulse, the maximal effect was higher (e_max=130%) and the time to e_max (t_emax) shorter (16.6 min) after the spray than the sublingual tablet (84.4% and 25.5 min) or peroral tablet (90.2 and 31.3 min). The onset of effect was within 3, 5 and 7.5 min after the spray, sublingual and peroral tablets, respectively. A larger change in the orthostatically-induced decrease in systolic blood pressure and increase in heart rate was obtained following peroral than sublingual administration despite the similar plasma concentrations of ISDN. This probably reflects the larger amount of pharmacodynamically active mononitrate metabolites formed after oral dosing. The integrated effect following administration of 2.5 mg ISDN as spray was similar to that of a sublingual tablet of 5 mg.