Presence of Propionibacterium acnes in blood components

BACKGROUND: Sterility testing, as part of the QC of blood components at the Japanese Red Cross Aichi Blood Center between April 1998 and March 2000, showed that 10 of 5568 tested blood components (0.18%), all of which were RBC concentrates, were contaminated with bacteria. Nine isolates were Propionibacterium acnes and one was Staphylococcus capitis. STUDY DESIGN AND METHODS: To investigate the molecular relatedness of eight available P. acnes isolates, 16S rRNA gene analysis and random amplified polymorphic DNA (RAPD) analysis were performed. RESULTS: DNA sequencing analysis of the 16S rRNA gene showed that five isolates were identified as distinct strains and that three had identical sequences. RAPD analysis in the latter three isolates showed that two exhibited indistinguishable banding patterns that differed from that of the third isolate. CONCLUSION: P. acnes was the most frequent contaminant of blood components, and six of eight isolates were molecularly unrelated. Further studies are necessary to investigate the precise mechanisms of contamination.     

乳腺仿真体模在超声专业住培教学中的应用

分析使用乳腺仿真体模在超声专业规培教学中的可行性。方法：选取2018年12月在杭州市第一人民医院培训的规培生作为实验组、进修生作为对照组,将乳腺仿真体模应用于规培教学,并进行进阶式理论及操作手法培训。通过操作考试、理论考试、课后问卷调查等方式进行教学效果分析。结果： 本研究实验组21人,对照组8人。培训后理论考试成绩实验组为68.10±8.14,对照组为50±12.24,两者有显著统计学意义。在同一年级不同阶段考试中,不同次的操作分数差异有统计学意义(F=106.59 P=0.00),问卷调查中100%学员认为在相关学习中获益。讨论：乳腺体模应用于超声规培教学的优点在于授课时便于规培医生理解解剖关系,方便男生进行敏感部位练习操作手法；缺点在于病变图像及位置固定,不利于高年级的业务能力提升。     

Human G protein β3 subunit variant does not alter hypercarbic or hypoxic ventilatory response

Hypercarbic respiratory drive is mainly determined by P_CO2 and pH with activity of the intracellular Na⁺/H⁺ exchanger (NHE) playing an important role in maintaining intracellular pH and respiratory drive. Because NHE activity varies with genetically different G‐protein β3 subunits (GNB3) (C/T polymorphism at nucleotide position 825) different genotypes might alter respiratory regulation. To test the hypothesis that short‐term ventilatory responses vary with different GNB3 healthy volunteers with different genotypes (CC, TC, TT) were exposed to either hyperoxic hypercarbia (n=33) or to isocapnic hypoxia (n=31), respectively. There was no difference between CC, TC, and TT genotypes in hypercarbic and hypoxic respiratory drive when assessed as the ratio of minute ventilation over endexpiratory P_CO2 changes (ΔV˙E /ΔPET _CO2), maximal tolerable PET _CO2, and ratio of changes in ventilation over arterial haemoglobin desaturation (ΔV˙_E/ΔS_O2), respectively. Thus, short‐term hypercarbic and hypoxic ventilatory drive do not differ between individuals with genotypes encoding different GNB3. Whilst respiratory control may still be influenced by G‐protein aberration, other mechanisms seem to have a more important role in controlling ventilation.     

SARS病房工作的医护人员血清中特异抗体测定分析

目的 检测密切接触SARS患者的医护人员血清中SARS病毒IgM及IgG抗体的水平，对SARS病毒有无隐性感染作初步调查。方法 分别用酶联免疫吸附法和间接免疫荧光法(IIFA)检测200例正常人，200例在SARS病房工作1个月的医护人员血清中SARS病毒IgM及IgG抗体的水平。结果 正常人及医护人员血清中未检测到SARS病毒IgM及IgG抗体。结论 不同于普通的流行性传染性疾病，SARS病毒可能不具有隐性感染性。     

Red Cell Glycolysis in a Case of 3-Phosphoglycerate Kinase Deficiency

Abstract. A severe deficiency in red cell 3-phosphoglycerate kinase was observed in a 62-year-old woman with haemolytic anaemia. Compared with a normal “young” red cell population with the same degree of reticulocytosis (6–7%) the 3-phosphoglycerate kinase activity was reduced to 27%. A concomitant decrease of hexokinase and pyruvate kinase (both reduced by about 30%) was observed. The activities of glucoses-phosphate dehydrogenase, phosphofructokinase, fructose-1,6-di-phosphate aldolase, gIyceraIdehyde-3-phosphate dehydrogenase and lactate dehydrogenase were slightly increased (7 to 15%). The total glycolytic output of the deficient cells was decreased by 28% at pH 7.0, by 36% at pH 7.4 and by 34% at pH 7.6. Compared with a normal “adult” red cell population the 3-phosphoglycerate kinase activity was reduced to 42% of the control values. Hexokinase, glyceraldehyde-3-phosphate dehydrogenase and lactate dehydrogenase activities were increased by approximately 20–50%. Phosphofructokinase activity was unchanged and pyruvate kinase only slightly increased. The steady state levels of the intermediates preceding the 3-phosphoglycerate kinase step were increased 2–3 fold. The subsequent metabolites were decreased or practically unmodified. ATP, ADP, NAD+, and NADH were not affected. The reduced glutathione level was increased and the ratio of reduced to oxidized glutathione was doubled. The glycolytic output and its pH-dependency were normal. The metabolic significance of the enzyme defect was assessed by the in vitro creation of cell stressing conditions, i.e. low pH and high pyruvate levels. In both cases, the 3-phosphoglycerate kinase activity became limiting at low pH, glucose-6-phosphate accumulated at a faster rate and fructose- 1,6-diphosphate and dihydroxyacetone phosphate disappeared more slowly in the deficient cells. After pyruvate loading these cells showed: a faster, more pronounced rise in 1,3-diphosphoglycerate and a decrease in 2,3-diphosphoglycerate (slightly increased in the controls): a drop in reduced glutathione (constant in the controls): constant ATP and slightly increased 3-phosphoglycerate concentrations (both strongly increased in the controls): a slight increase in NADH (dropped to nil in the controls). Steady state glycolysis under normal conditions seemed to be affected by the enzyme deficiency. 3-phosphoglycerate kinase however, became more severely limiting a low pH or after the addition of pyruvate. In these conditions, the flow was diverted to the 2,3-diphosphoglycerate bypass, less ATP was produced and the concentration of reduced glutathione decreased. This may be assumed to have led to impairment of the ionic pump and may thus explain the increased haemolysis.     

Evaluation of the Atrial Evoked Response for Capture Detection with High-Polarization Leads

AutoCapture™ based on the evoked response can be confounded by electrode polarization. In this study, polarization was measured in human subjects who had chronic atrial leads. The aim of the study was to determine whether electrode polarization can be measured using a time integral atrial evoked-response integral (AERI) of the negative portion of the atrial paced ER evoked-response signal and to determine whether high-polarization atrial leads unsuitable for AutoCapture™ can be identified a priori. Atrial intracardiac-electrogram (IEGM) signals from 39 patients with implanted pacemakers were recorded and analyzed. The signals were recorded during conventional atrial-threshold searches. A total of 221 atrial-capture thresholds were recorded, ranging from 0.25 to 2.75 V with a mean of 0.79 V. Each evoked response was evaluated using the AERI in a 36 ms window following the 0.4 ms atrial stimulus. The polarization was estimated as a linear function of stimulus voltage using the evoked-response signal integral of captured beats identified on the IEGM. The 221 threshold-search datasets were obtained using leads with eight different electrode materials. Polarization could be measured using AERI as a function of stimulus voltage. Furthermore, this polarization measure can be used to identify high-polarization leads, which are ill suited for the atrial AutoCapture™ algorithm.     

砷剂和维甲酸对 NB4细胞组织因子和凝血酶调节蛋白mRNA及促凝活性的影响

为了研究三氧化二砷(As203)和全反式维甲酸(ATRA)对NB4细胞组织因子(TF)和凝血酶调节蛋白(TM)mRNA及其表达的影响,本研究采用体外细胞培养方法,以As2O3、ATRA处理NB4细胞,用ELISA动态测定其TF、TM抗原表达及促凝活性(PCA)变化,用逆转录-聚合酶链反应(RT-PCR)测定TF和TM的mRNA转录.结果表明1 μmol/L的As2O3和1 μmol/L ATRA均可使NB4细胞TF抗原及mRNA表达呈时间依赖性渐进性下调;在24、48、72、96和120小时时间点,As2O3组TF抗原的表达水平分别为13.3±1.8,8.6±1.9,10.8±1.5,2.0±0.6和2.6±0.9 ng/107;ATRA组TF抗原的表达水平分别为12.4±1.1,11.3±1.8,5.7±1.7,2.8±0.8和2.0±0.6 ng/107,与对照组比较具有显著性(P＜0.05);在不同的时间点As2O3和ATRA,均可使其PCA下降,As2O3组血凝时间分别为123.5±10.5,156.3±11.6,179.3±15.3,248.9±20.1,312.0±29.8(秒);ATRA组血凝时间分别为76.4±5.6,146.8±10.9,198.2±15.6,265.8±20.6和363.8±31.9(秒);ATRA使NB4细胞TM抗原表达及其mRNA转录上调.结论As2O3、ATRA可降低TF mRNA转录,下调TF蛋白表达,降低NB4细胞PCA;ATRA增高TM转录及表达,缓解APL患者凝血功能异常.     

调神方对老年性痴呆大鼠学习记忆和细胞因子调节的实验研究

目的探讨调神方对老年性痴呆(AD)大鼠学习记忆和细胞因子调节的作用机制。方法建立AD鼠模型,分为正常组、衰老组、假损伤组、模型组、调神方组、他克林组,观察Y-电迷宫和血清细胞因子。结果调神方能明显提高Y-电迷宫正确次数,明显下调血清白介素-1β(IL-1β)、白介素-6(IL-6)的水平。结论调神方可能通过调整AD大鼠的免疫状态而提高学习记忆能力。     

"肾生髓"与中枢神经系统功能的关系

目的 从神经生理学角度,探讨中医"肾生髓"的本质 ,为"肾生髓"理论提供科学依据. 方法 2.5月龄 SD雄性大鼠,以单纯随机方法分成正常对照组、去势组和虚劳组.用听觉脑干诱发电位( ABR)、体感诱发电位( SEP)以及氨基酸类和单胺类中枢递质含量为指标,观察虚劳肾虚和去势肾虚模型大鼠的中枢神经系统( CNS)功能状况. 结果肾虚模型大鼠睾酮( T)水平下降时,虚劳组 [(271± 20) mg]胸腺质量明显低于正常对照组 [(565± 81) mg](P< 0.01).与对照组比较,肾虚模型大鼠神经系统功能下降,表现为造模后 ABR峰潜伏期延长( F=6.713,P< 0.001) , 阈值提高( F=9.555, P< 0.001); SEP的峰潜伏期延长( F=4.161, P=0.002),差异有非常显著性意义.中枢递质含量下降. 结论肾虚时血 T水平低下影响 CNS的兴奋性,这一作用可能是"肾"(性腺激素)通过调制某些中枢递质的合成与释放而产生效应的结果.     

Acute saline infusion induces extracellular acidification and activation of the Na+/H+ exchanger in man

The effect of acute expansion of the extracellular fluid volume (ECV) with isotonic (0.9%) saline on the activity of the lymphocyte Na⁺/H⁺ antiport (NHE) was studied in a total of 18 healthy volunteers. Saline was infused at a constant rate so that 4 mmol kg^?1 b.w. was administered over 2 h. NHE activity was measured by quantifying cytosolic pH (pH_i) recovery following acidification of the cells with propionic acid and by pH clamping at various pH_i values between 7.2 and 5.8 using nigericin. Both methods demonstrate NHE activation associated with intravenous saline infusion, the kinetic difference being a marked decrease in the Hill coefficient n from 3.28 ± 0.21 (SEM) to 2.22 ± 0.11 in the absence of changes in baseline pH_i (7.14 ± 0.02 vs. 7.08 ± 0.02; P = 0.15), V_max (42.8 ± 2.7 vs. 48.1 ± 2.8 mmol L^?1 min^?1; P = 0.08) and pK (6.32 ± 0.04 vs. 6.35 ± 0.02). NHE activation was associated with significant decreases in serum chloride (P = 0.016), calcium (P = 0.008), total cholesterol (P = 0.008), low-density lipoproteins (P = 0.016) and high-density lipoproteins (P = 0.008). Moreover, saline infusion induced extracellular acidification with a decrease in pH from 7.39 ± 0.01 to 7.37 ± 0.01 (P = 0.016), HCO₃^? from 23.3 ± 0.43 mmol L^?1 to 21.3 ± 0.25 mmol L^?1 (P = 0.008) and base excess from ?1.03 ± 0.38 mmol L^?1 to ?3.00 ± 0.31 mmol L^?1 (P = 0.008). Our results show for the first time that acute ECV expansion with isotonic saline is followed by an activation of the lymphocyte NHE. The underlying mechanism(s) remain to be investigated. However, the demonstration in our study of marked changes in acid–base balance induced by acute saline points to a possible inter-relationship of antiporter activation and extracellular acidification.