In vitro function and post-transfusion survival of granulocytes collected by continuous-flow centrifugation and by filtration leukapheresis

The function of granulocytes collected by continuous-flow centrifugation (CFC) and by filtration leukapheresis (FL) was studied in vitro, and the post-transfusion recovery and intravascular survival of these cells was studied by autologous transfusion in normal donors. Granulocytes collected by both FL and CFC leukapheresis (CFCL) functioned normally in the quantitative nitroblue tetrazolium, oxygen consumption, and chemotaxis assays. Bacterial killing was slightly but consistently decreased in FL but not CFCL granulocytes. The post-transfusion recovery of control granulocytes collected by ordinary phlebotomy averaged 52% in eight transfusions, compared with 34% for six CFCL granulocyte concentrates and 16% for six FL concentrates. The intravascular half-times were 3.8 hr for phlebotomy and 3.0 hr for CFCL granulocytes. FL granulocytes had survival curves which were nonlinear and a single half-life could not be calculated. The average half-time 30 min after transfusion was 1.3 hr, and 3 hr after transfusion it was 2.6 hr. Granulocytes collected by FL had a mild impairment of bacterial killing, decreased post-transfusion recovery, and altered intravascular kinetics. None of these abnormalities was found in granulocytes collected by CFCL.     

Quantitative microanalysis of cell walls of Saprolegnia diclina Humphrey and Tremella mesenterica Fries

Cell walls of the fungi Saprolegnia declina Humphrey and Tremella mesenterica Fries were analyzed quantitatively. Particular attention was paid to the hydrolysis and analysis of neutral sugars, amino sugars and amino acids. These components, together with total lipids, total uronic acids and the ashed residue, accounted for more than 90% by weight of the original dry cell wall preparation. There were substantial losses of amino acids during hydrolysis; however, analytical recovery approached 100% when total protein was calculated from the total nitrogen analysis. The analytical procedures were reproducible (+/- 3% for amino acids and amino sugars, and +/- 5-10% for other components) when applied to individual cell wall preparations. However, even under carefully standardized conditions, different cell wall preparations from the same species showed variable composition. Glucose was the predominant neutral sugar in the cell wall polymers of both species. The amino acid compositions were remarkable in that neither species contained detectable levels of cyst(e)ine. Hydroxyproline was detected in both species. The report from Tremella mesenterica is the first for this amino acid from the cell wall of a Basidiomycete.     

Type II ostertagiasis in adult cattle

During the spring of 1975 outbreaks of ostertagiasis affecting adult cattle were recorded from several beef herds. Two of these outbreaks, one involving an autumn calving herd and the other spring calving, were investigated in detail. The clinical, biochemical, haematological, parasitological and pathological findings are described and were similar to those characteristic of type II ostertagiasis in immature cattle.     

ZnO 气敏材料的研究进展

本文着重介绍了粉末状 Zn O气敏材料的制备和掺杂的研究进展 ,并指出了存在的问题和今后发展的方向     

柴油机活塞环/缸套摩擦副匹配性能的试验

根据柴油机缸套、活塞环快速模拟磨损的试验结果，讨论了首环镀铬对缸套耐磨性的影响，探讨了新材质活塞环取代油环镀铬的可行性，分析了活塞环失效的原因。通过试验证明，改进设计后的新材质活塞环组，耐磨性能和可靠性能明显提高，这对降低柴油机的机油耗。提高活塞环使用寿命有重要影响。     

基于两分量法在中性点不接地系统应用研究

由对称分量导出了两分量法,分析了两分量法解电力系统故障方法及与对称分量间关系,得出中性点不接地系统相间故障用差量解相间故障的方法。分析了差量选相原理,提出了采用差量突变量单端测距理论基础,测距精度满足工程要求。提出了中性点不接地系统只有两相装设电流互感器求解差量处理方法。     

Leptin concentrations in the follicular phase of spontaneous cycles and cycles superovulated with follicle stimulating hormone

It has been reported that oestradiol may play a role in the production of leptin from adipocytes. To investigate this relationship further, nine normally ovulating women were studied during two menstrual cycles, i.e. an untreated spontaneous cycle and a cycle treated with follicle stimulating hormone (FSH) from cycle day 2 until the day of human chorionic gonadotrophin (HCG) injection. Serum leptin values on cycle day 2 did not differ significantly between the spontaneous and the FSH cycles. In the spontaneous cycles, leptin values declined gradually and significantly up to day 7 and then increased progressively up to the day of luteinizing hormone (LH) surge onset, at which point they achieved the highest values. In the FSH cycles, serum leptin values increased gradually and significantly up to day 6, remaining stable thereafter, and were in the midfollicular phase significantly higher than in the spontaneous cycles. Significant positive correlations were found between mean values of leptin and mean values of oestradiol during the second half of the follicular phase in the spontaneous cycles and during the first half in the FSH cycles. A significant negative correlation was found between these two parameters in the spontaneous cycles during the first half of the follicular phase. Serum leptin levels were significantly higher in the midluteal than in the follicular phase in both cycles. These results demonstrate for the first time significant changes in leptin values during the follicular phase of the human menstrual cycle and a significant increase during superovulation induction with FSH. It is suggested that oestradiol may be involved in the regulation of leptin production in women.