Human tonsil,blood and bone marrow in vivo-induced B cells capable of spontaneous and high-rate immunoglobulin secretion in vitro: Differences in the requirements for factors and for adherent and bone marrow stromal cells,as well as distinctive adhesion molecule expression

Human B cells capable of spontaneous IgG secretion are commonly found in circulation and in lymphoid tissues such as tonsil and bone marrow (BM). The present study compares the mechanisms that regulate tonsil, blood and BM B cells capable of spontaneous IgG secretion. The BM cell subset produced IgG during a markedly longer period of time (14 days) than did tonsil and blood cell subsets (2–3 days). Blood and BM, but not tonsil, B cell IgG secretion depended on the presence of adherent cells, as demonstrated by adherent cell depletion and re-addition experiments. Stromal BM cells supported linear IgG secretion by non-adherent BM cells for 2 weeks, but were unable to prolong the short-term IgG secretion by tonsil and blood cells. Different factors induced IgG secretion in each of the three B cell populations as optimal IgG secretion by tonsil, blood or BM cell subsets required either tumor necrosis factor-α, interleukin-6 or fibronectin + interleukin-6, respectively. Finally, these populations also showed differences in the expression of adhesion molecules; the tonsilar cell subset was PNA^+/? CD44⁺ CD49d⁺ CD49e^? Leu-8^+/?, the blood cell subset was PNA^? CD44^+/? CD49d⁺ CD49e^? Leu-8⁺ and the BM cell subset was PNA^? CD44^+/? CD49d⁺ CD49e^? Leu-8^?. These results suggest that the mechanisms controlling the final differentiation and the expression of adhesion molecules in these B lymphocytes exhibit territorial specificity.     

Human spumaretrovirus antibody reactivity in multiple sclerosis

The role of human spumaretrovirus (HSRV) infections in the pathogenesis of multiple sclerosis (MS) was investigated with recombinant HSRV env-specific enzyme-linked immunosorbent assay. The presence of HSRV antibodies was determined in pairs of serum and cerebrospinal fluid (CSF) samples from 60 MS patients. In 7 of these patients serial serum and CSF samples were obtained in relation to the clinical activity of the disease during a period of 2 years. No increased antibody reactivity was demonstrable in the MS population compared with 14 aseptic meningitis patients, 50 blood donors and 16 healthy controls. Slightly elevated levels of antibodies were demonstrable in serum and/or CSF in 4 MS patients but also in 1 patient with aseptic meningitis, 1 blood donor and 1 child. No marked serum or CSF HSRV antibody fluctuation was observed in the MS patients followed longitudinally. Thus, this study does not support the involvement of HSRV in the pathogenesis of MS.     

胶体金免疫层析法检测尿hCG的质量控制方法探讨

目的通过对胶体金免疫层析法（GICA）试纸条评价,建立该方法的检测尿hCG的室内质控.方法利用hCG不同浓度的标准品评价试纸条的敏感性、重复性、稳定性、检测范围,检测温度及时间对试纸条检测尿hCG结果的影响等.结果GICA的检测范围25-100万mlU/ml,最低检出限达25mIU/ml,大于200万mIU/ml时存在后带现象.试纸条反应5分钟后呈色均一,最佳检测温度为4-30℃.结论灵敏度检测可作为GICA室内质控的主要指标,它能保证检测结果的准确性.     

Cytochromes of the P450 2C subfamily are the major enzymes involved in the O-demethylation of verapamil in humans

The calcium channel blocker verapamil [2,8-bis-(3,4-dimethoxyphenyl)-6-methyl-2-isopropyl-6-azaoctanitrile] undergoes extensive biotransformation in man. We have previously demonstrated cytochrome P450 (CYP) 3A4 and 1A2 to be the enzymes responsible for verapamil N-dealkylation (formation of D-617 [2-(3,4-dimethoxyphenyl)-5-methylamino-2-isopropylvaleronitrile]), and verapamil N-demethylation (formation of norverapamil [2,8-bis(3,4-dimethoxyphenyl)-2-isopropyl-6-azaoctanitrile]), while there was no involvement of CYP3A4 and CYP1A2 in the third initial metabolic step of verapamil, which is verapamil O-demethylation. This pathway yields formation of D-703 [2-(4-hydroxy-3-methoxyphenyl)-8-(3,4-dimethoxyphenyl)-6-methyl-2-isopropyl-6-azaoctanitrile] and D-702 [2-(3,4-dimethoxyphenyl)-8-(4-hydroxy-3-methoxyphenyl)6-methyl-2-isopropyl-6-azaoctanitrile]. The enzymes catalyzing verapamil O-demethylation have not been characterized so far. We have therefore identified and characterized the enzymes involved in verapamil O-demethylation in humans by using the following in vitro approaches: (I) characterization of O-demethylation kinetics in the presence of the microsomal fraction of human liver, (II) inhibition of verapamil O-demethylation by specific antibodies and selective inhibitors and (111) investigation of metabolite formation in microsomes obtained from yeast strain Saccharomyces cerevisiae W(R), that was genetically engineered for stable expression of human CYP2C8, 2C9 and 2C18.In human liver microsomes (n=4), the intrinsic clearance (CL_int), as derived from the ratio of V _max/K_m, was significantly higher for O-demethylation to D-703 compared to formation of D-702 following incubation with racemic verapamil (13.9±1.0 vs 2.4±0.6 ml^*min^{-1 *}g^-1 mean±SD; p<0.05), S-Verapamil (16.8±3.3 vs 2.2±1.2 ml^* mini^*g^-1, p<0.05) and R-verapamil (12.1±2.9 vs 3.6 ±1.3 ml^*min^{-1 *} g^-1; p<0.05), thus indicating regioselectivity of verapamil O-demethylation process. The CL_int of D-703 formation in human liver microsomes showed a modest but significant degree of stereo selectivity (p<0.05) with a S/R-ratio of 1.41±0.17. Anti-LKM2 (anti-liver/kidney microsome) autoantibodies (which inhibit CYP2C9 and 2C19) and sulfaphenazole (a specific CYP2C9 inhibitor) reduced the maximum rate of formation of D-703 by 81.5±4.5% and 45%, that of D-702 by 52.7±7.5% and 72.5%, respectively. Both D-703 and D-702 were formed by stably expressed CYP2C9 and CYP2C18, whereas incubation with CYP2C8 selectively yielded D-703.In conclusion, our results show that enzymes of the CYP2C subfamily are mainly involved in verapamil O-demethylation. Verapamil therefore has the potential to interact with other drugs which inhibit or induce these enzymes.     

Quantification of naturally occurring benzodiazepine-like substances in human breast milk

The possible occurrence of benzodiazepine-like substances in human breast milk was investigated in 35 healthy, newly delivered women who were known not to be taking benzodiazepines. Maternal blood samples and a sample of breast milk were obtained on the fifth post partum day. A radioreceptor technique (lower limit of detection 1.5 ng/ml; difference between duplicates at various concentrations <7%) was used for measuring benzodiazepine-like substances in blood and breast milk (with and without prior extraction). No benzodiazepine-like substances could be demonstrated in any of the blood samples taken from the 35 women. Measurable concentrations of benzodiazepine-like substances were demonstrated in all but 1 of the 35 breast milk samples. The mean concentration of benzodiazepine-like substances for all 35 women was 4.3±2.3 ng/ml (range 0–9.3 ng/ml) expressed as lorazepam. The corresponding value for extracted breast milk was 2.6±1.5 ng/ml (range 0–7.0 ng/ml). There was no association between concentrations of benzodiazepine-like substances in breast milk and maternal age, weight, height and body mass or parity, or the sex of the infant and infant birth weight. We suggest that non-detectable amounts of benzodiazepine-like substances in serum are concentrated in the mammillary glands and excreted in a higher concentration in breast milk. It is less likely that the relevant benzodiazepines are produced in the mammillary glands.     

Cross talk in surface electromyograms of human hamstring muscles.

Signals generated from muscles other than the muscle(s) of interest (cross talk) can confound the interpretation of surface electromyograms (EMGs). In this study, the amount of cross talk in surface EMGs of human hamstring muscles was estimated using a protocol in which the quadriceps femoris was electrically stimulated via the femoral nerve. EMGs were recorded from the vastus lateralis and the medial and lateral hamstring muscle groups. The amplitude of the EMG response of the vastus lateralis to electrical stimulation was adjusted to match that of its maximum voluntary effort (MVE) under isometric conditions. Subsequent power density spectrum analysis showed that the median frequencies of the signals generated by electrical stimulation and MVE were not significantly different. In conventional bipolar recordings, cross talk in lateral hamstring EMGs averaged 17.1% MVE and in medial hamstring EMGs 11.3% MVE (average-rectified values). The double differential technique significantly reduced cross talk to 7.6% MVE for the lateral hamstrings, and to 4.2% MVE for the medial hamstrings. The double differential technique appears to be more selective than the bipolar technique when recording EMGs from muscles with highly active neighbors and thus should be used in such situations. Software simulations of the double differential technique also appear to be more selective than the bipolar technique and may be used when the number of amplifiers available is limited.     

Indium-111 labelled pooled human immunoglobulin imaging to monitor the efficacy of specific therapy for Pneumocystis carinii pneumonia

Functional imaging is ideally suited to monitoring the effect of specific therapy on disease processes. In this pilot study five patients with AIDS and Pneumocystis carinii pneumonia (PCP) were imaged with Indium-111 labelled pooled human immunoglobulin (111In-HIG) during infection and after therapy for PCP. The lung activity of t t tln-HIG, measured as a lung/heart ratio, was calculated in a study performed during infection with PCP and after therapy. In all five patients the lung/heart ratio of t t 1ln-HIG was reduced after treatment. The mean reduction in heart/lung ratio was 27% (range 12%-53%). If these results are confirmed by a larger study, ¹¹In-HIG will be useful in monitoring the response of PCP to therapy in patients with AIDS.     

纤维结合素角膜上皮愈合作用的研究

人血浆纤维结合素对家兔刮除和板层切除后的角膜上皮愈合均有一定促进作用，角膜上皮裸区明显缩小，优于对照眼。临床治疗５类角膜上皮障碍５９例６１眼，均获得显著疗效。     

人胎盘提取组织凝血活酶及其质量评价

利用人胎盘抽提得组织凝血活酶，并对其质量进行了评价，同时初步应用于临床。结果显示：用含表面活性剂的抽提剂粉碎抽提的效果较好，所得组织凝血活酶重复性、灵敏度、稳定性均令人满意；与上海荣盛生物制品厂生产的ＰＴ试剂盒比较相关性好：Ｙ＝２．７５＋０．９０５ｘ，ｒ＝０．９２５３，经相关系数ｔ检验，ｔ＝２６．５４６９，Ｐ＜０．００１，呈直线正相关。临床初步应用显示：肝病及抗凝治疗等病人ＰＴ时间明显延长，９３例正常人ｘ＝１１．３秒，ｓ＝０．９６秒，正常范围９．４２－１３．１８秒。     

聚合酶链反应检测尖锐湿疣皮损内人乳头瘤病毒

１３个皮损组织取自１３例尖锐湿疣（ＣＡ）患者，１３例基底细胞上皮瘤（ＢＣＣ）组织作为对照，用溴化钠液分离表真皮，从组织中提出的 ＤＮＡ和溴化钠液分别用聚合酶链反应检测 ＨＰＶ ＤＮＡ。１１例ＣＡ表皮中检出 ＨＰＶ ＤＮＡ，ＨＰＶ６有７例，ＨＰＶ１１有４例。３例ＣＡ真皮中发现有ＨＰＶ ＤＮＡ，ＨＰＶ６有２例，ＨＰＶ１１有１例。２例标本因溴化钠液被ＨＰＶ污染未作统计。在ＢＣＣ组织中未发现有ＨＰＶ ＤＮＡ。在某些ＣＡ真皮内含有 ＨＰＶ ＤＮＡ可以解释散发病例的复发性。