Role of Periductal and Ductular Epithelial Cells of the Adult Rat Pancreas in Pancreatic Hepatocyte Lineage: A Change in the Differentiation Commitment

Development of pancreatic hepatocytes in adult rats maintained on copper deficient diet containing 0.6% trien (CuDT) has been reported recently. To elucidate the histogenesis of hepatocytes a sequential study was undertaken using morphologic, histochemical, immunochemical, in situ hybridization, and Northern blot analysis. Male F-344 rats weighing 80 to 90 g were fed CuDT for 8 weeks and returned to normal rat chow. Beginning from 4 weeks of copper depletion, there was a progressive loss of acinar cells and by 8 weeks more than 90% of the acinar tissue was lost. During this period, there was an increase in the number of adipocytes in the interstitium, and in the number of interstitial and ductular cells. Morphologic observations were confirmed by immunoblot and Northern blot analysis, in which the amount of pancreatic proteins and their mRNAs decreased between 5 and 8 weeks. During this period, a progressive increase in the level of albumin mRNA was observed. In situ hybridization, performed at 7 weeks of copper deficiency, showed localization of albumin mRNA over interstitial and ductular cells. Pancreatic hepatocytes were identified immediately after the rats were returned to a normal diet and gradually increased in number. The hepatocytes occupied almost 60% of the pancreatic volume by 8 weeks. During the early recovery phase, hepatocytes were identified in ductules as well as in the interstitium. Based on these studies, it is concluded that both the ductular cells and interstitial cells, which resemble oval cells of liver, are capable of transforming into pancreatic hepatocytes and these cells may be considered stem-cell equivalent.     

Firing rate and size distribution of the hind limb extensor and flexor motoneuronal units

Axonal spike size of extensor and flexor motoneurones were subjected to statistical analysis. Extensor motoneurones were isolated in decerebrate cats and the flexor motoneurones in spinalized cats. Smallest spikes were due to gamma motoneurones which could be further classified as small, medium and large. Extensor and flexor alpha motoneuronal units were also divided into these three subgroups. Considering the firing pattern and the cell size extensor alpha units were divided into five types: small-tonic, medium-tonic, large-tonic, large-phasic and largest-phasic. Maximum firing rate of extensor alpha units was directly related to the cell size and was distributed between 5-15, 15-20, 25-40 and 35-55 imp/sec for the small-tonic, medium-tonic, large-tonic and large-phasic motoneurones. Stabilized firing rates were distributed between 5-10, 10-15 and 15-20 imp./sec for the small-tonic, medium-tonic and large-tonic motoneurones. Flexor motoneuronal types and their maximum firing rates were as follows: small-tonic (16 imp./sec), medium-tonic (24 imp./sec), small-phasic (37.5 imp/sec), medium-phasic (30 imp./sec), large-phasic (46 imp./sec) and largest-phasic (only one or two impulses). The functional significance of the results was discussed considering the axonal spike size as an index for the cell size.     

基因探针监测巨细胞病毒潜伏感染的母儿间传播

本文采用基因探针检测孕妇静脉血及新生儿脐静脉血白细胞中CMVDNA，同时应用ELISA检测其血清中IgG、IgM．结果：10例孕妇CMV-DNA阳性，占8．7％(10／115)，这10例孕妇血IgG均阳性，IgM均阴性；17例新生儿CMV—DNA阳性．占14．3％(17／119)，其中IgM阳性2例，占1．7％(2／119)。本次研究中配对者79例，母儿CMV—DNA均阳性者8例，新生儿CMV—DNA阳性而母亲阴性者4例。上述CMV-DNA阳性者均无临床症状。研究结果提示基因探针可监测CMV的潜伏感染，从而进一步研究CMV感染的母儿传播机制。     

重组风疹病毒外膜蛋白E1的表达及其在血清学中的初步应用

目的 在大肠埃希菌中表达重组风疹病毒外膜蛋白E1,用其作为包被抗原,建立一种用于诊断风疹病毒感染的ELISA检测方法 .方法 通过基因重组的方式构建表达质粒并在大肠埃希菌中表达风疹病毒外膜蛋白E1,蛋白纯化后作为包被抗原,用ELISA的方法 检测世界卫生组织(WHO)的风疹检测质控血清以及来自广西桂林的未知血清样本.结果 采用WHO用于风疹检测的质控血清对所表达的重组抗原的抗原性进行鉴定,通过试验,特异性、敏感性均为100%.用表达的抗原对来自我国广西的200份未知血清样本进行风疹病毒外膜蛋白抗体的检测,阳性率为93%,与文献报道的我国其他地区风疹病毒抗体阳性率基本一致.结论 通过实验我们表达了具有良好抗原性的风疹病毒外膜蛋白E1,为进一步研究风疹病毒感染的实验室诊断技术奠定了基础.     

A phage-displayed single chain variable fragment that interacts with hepatitis B core antigen: library construction, selection and diagnosis.

BACKGROUND: Phage display is an alternative method for constructing and selecting antibodies with desired specificity towards an antigen. OBJECTIVES: To construct a library of single chain variable fragment (ScFv) towards hepatitis B core antigen (HBcAg). To isolate a ScFv phage clone that interacts with HBcAg and to develop a phage-ELISA for detecting the antigen. STUDY DESIGN: Mice were inoculated with HBcAg and RNA was extracted from their spleen cells. The genes encoding heavy (V(H)) and light (V(L)) chains were amplified, linked via PCR and cloned into a phagemid vector. Phage particles displaying ScFv were panned against HBcAg and a selected clone was characterized and employed as a diagnostic reagent for detecting HBcAg in serum samples. RESULTS: A phage clone that interacts with HBcAg was selected from the antibody library. The binding of the phage to HBcAg was inhibited by a cyclic peptide bearing the WSFFSNI sequence. A phage-ELISA was established using the recombinant phage and as low as 10ng of HBcAg can be detected by the assay. CONCLUSION: The ScFv displayed on the surface of filamentous phage is an alternative choice for diagnosis of HBcAg in serum samples.     

^99mTc-DTPA肾动态显像及β2-m水平在评价肾移植受者肾功能中的价值

目的：探讨^99mTc-DTPA肾动态显像半定量参数和血、尿β2-m水平测定对肾移植术后早期并发症诊断与鉴别诊断的价值。方法：28例肾移植病人术后均进行放射性核素^99mTc-DTPA肾动态显像,同时测定移植肾的肾小球滤过率（GFR）、膀胱放射性计数与移植肾放射性计数比值（B/K值）和移植肾放射性1min计数与腹主动脉放射性1min计数比值（K1min/A1min比值）。在进行放射性核素肾动态显像前所有病人均收集其血液和尿液标本,采用放射免疫分析测定血、尿β2-m水平。结果：12例肾功能正常者肾动态显像示肾血流灌注及功能良好,GFR值为（49.1±6.1）ml/min,B/K值均〉3,K1min/A1min比值为8.18±1.41;4例急性排斥反应者肾血流灌注受损程度重于功能相,GFR值为（33.2±5.3）ml/min,B/K值均〈1,K1min/A1min比值为2.59±0.86,β2-m水平以血β2-m升高明显;8例慢性排斥反应者肾血流灌注和功能相均同时受损,GFR值为（19.8±7.5）ml/min,B/K值均〈1,K1min/A1min比值为2.19±0.84,β2-m水平也以血中升高明显;2例肾小管坏死者及2例环孢素A肾中毒者肾血流灌注受损均轻于功能相,GFR值分别为（38.5±4.1）ml/min和（39.4±5.81）ml/min,B/K值均〈1,K1min/A1min比值分别为5.83±0.84和6.01±0.66,β2-m水平以尿中升高显著。结论：放射性核素肾动态显像半定量参数K1min/A1min比值和B/K值,结合肾移植病人术后血、尿β2-m水平联合分析可早期初步鉴别排斥反应的类别,可作为判断移植肾受损程度、原因及预后估测的敏感指标。     

Andrology: Factors influencing the outcome of in-vitro fertilization with epididymal spermatozoa in irreversible obstructive azoospermia

Microsurgical epididymal sperm aspiration (MESA) and in-vitrofertilization (IVF) were found to offer limited opportunityfor fatherhood to 45 men with obstructive azoospermia, due principallyto poor embryo implantation. Adequate sperm preparations wereobtained in 46/50 treatment cycles (92%), with the best motilityfound in the caput epididymis in 89% of cases. The mean fertilizationrate was 11.2% and fertilization occurred in 23 cycles (50%),with embryo transfer arising from 12/26 men with was aplasia(CAV), 4/9 with genital tract obstruction (EV) and 7/11 withirreversible vasectomy (VV). The overall implantation rate waslow, 8.7% per embryo transfer (11.7% per 2-3 embryo transfers)and was not improved by Fallopian transfer. There were two pregnancies(4% per cycle), both in the EV group where embryo formationand implatation (2/4, 50% per cycle) were optimum even thoughsperm preparations were paradoxically inferior to the CAV andVV groups. The spermatozoa retrieved in the two successful EVcycles were appreciably blood contaminated. Analysis of the21 failed embryo transfers showed delayed fertilization in 10cycles, cystic fibrosis (CF) mutation or familial disease in7/12 CAV men and the VV men were older (P<0.001). A pregnancywhich miscarried arose from a case of Young's syndrome, a carrierof CF mutation DF508. Male factors could thus be implicatedin the high embryo wastage of MESA cycles and might also beinfluencing implantation in other IVF procedures. Where feasible,male reconstructive surgery is preferable unless fertilizationcan be improved, possibly by speedier retrieval techniques orby permitting sperm capacitation in vitro, but probably moreeffectively by micro-assisted insemination.     

Role of Der p 1–specific B cells in immune tolerance during 2 years of house dust mite–specific immunotherapy

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脑缺血时皮层扩布性抑制与心功能障碍

目的 :研究树 鼠句脑缺血时单胺氧化酶 (MAO)活化在脑缺血时心功能障碍以及扩布性抑制中的可能作用。方法 :采用光化学法诱导树 鼠句血栓性脑缺血 ,测定缺血区及血清MAO活性、多巴胺及去甲肾上腺素 (NA)水平 ,经电镜观察脑及肾上腺的超微结构。记录仪检测心率(HR)、左室收缩压峰值 (LVSP) ,左室瞬间收缩与舒张最大速率 (±dp/dtmax) ,左室舒张末期压力 (LVEDP) ,平均动脉压 (MAP)。结果 :树鼠句脑缺血过程中血清NA先升高 (由 11.60± 0 .73ng/ml升高至18.46± 0 .3 9ng/ml,P <0 .0 1) ,72h后降至 8.3 2± 1.86ng/ml;血清MAO活性逐渐升高 ,达 2 10 .1± 2 6.67U/ml(P <0 .0 1) ,72h降低至对照水平 ;心功能指标 (±dp/dtmax,LVSP ) ,尤其是HR明显降低 ,由3 17.0± 98.0 1beat/min降至 2 3 7.4± 3 1.90beat/min(P <0 .0 1) ,于2 4h恢复至对照水平。结论 :血栓性脑缺血时血清NA水平明显取决于MAO活性的变化 ,后者对脑缺血时心脏舒缩功能可能具有调节作用。     

IL-1α及与IL-11、LIF和GDNF联合诱导胚鼠皮质、中脑神经干细胞向多巴胺神经元分化的比较

为比较皮质和中脑来源的神经干细胞(NSCs)定向分化为多巴胺神经元的情况,应用无血清和单克隆培养技术,分别从皮质和中脑组织中分离克隆、扩增NSCs,然后分成3组诱导分化:①对照组用10%胎牛血清诱导分化;②IL-1α组在10%胎牛血清的基础上加IL-1α诱导分化;③联合因子组在10%胎牛血清的基础上加IL-1α、IL-11、LIF及GDNF进行诱导分化。用酪氨酸羟化酶(TH)免疫组化染色检测多巴胺神经元。在100倍镜下随机取5个视野,计数每个视野中的TH阳性神经元数;并用图像分析软件处理TH阳性神经元的胞体面积和细胞周长;用STATA7.0统计软件进行统计处理。结果显示,皮质对照组中仅见极少的TH阳性神经元(0.25±0.163),中脑对照组中见少量TH阳性神经元(2±0.378);而皮质IL-1α组有较多的TH阳性神经元(15.5±0.866),中脑IL-1α组中的TH阳性神经元则为皮质IL-1α组的150%(22.875±1.517);皮质联合因子组中的TH阳性神经元数(25.75±0.940)与中脑联合因子组中的TH阳性神经元数(28.875±2.125)接近,无显著差异。胞体面积和细胞周长的结果显示出IL-1α组和联合因子组大于对照组、而联合因子组又优于IL-1α组的趋势。上述结果提示,中脑来源的NSCs本身具有一定的分化为多巴胺神经元的区域特异性,而皮质来源的NSCs在IL-1α、IL-11、LIF及GDNF等细胞因子的诱导下可改变其区域特异性而分化为较多较为成熟的多巴胺神经元。