乙型肝炎病毒表面抗原单链抗体细胞内免疫抗乙型肝炎病毒基因治疗研究

目的 :研究乙型肝炎病毒表面抗原 (HBsAg)人源单链可变区抗体 (ScFv)细胞内免疫抗乙型肝炎病毒(HBV)基因治疗的作用。方法 :用噬菌体表面展示技术筛选特异性的HBsAg人源单链可变区抗体 ,聚合酶链反应(PCR)法扩增HBsAg单链抗体基因 ,并构建表达HBsAgScFv基因的重组逆转录病毒载体pLXSN HBsAgScFv,转染PA317细胞 ,将转染细胞分泌的假病毒颗粒感染 2 2 15细胞 ,酶联免疫吸附法 (ELISA)检测其上清HBsAg和HBeAg ,定量检测HBVDNA。结果 :成功筛选出HBsAgScFv ,PCR扩增出 75 0bp的全基因 ,构建HBsAgScFv基因的逆转录病毒载体 ,转染PA317细胞 ,在上清中检测出含HBsAgScFv假病毒颗粒的存在 ,上清感染 2 2 15细胞后第 3、5、7、14天 ,HBsAg、HBeAg逐渐下降 ,到第 14天时HBsAg已变为阴性 ,DNA定量检测无明显变化。结论 :HBsAgScFv能成功地在逆转录病毒载体中表达 ,并有抑制HBsAg、HBeAg表达的作用     

聚乳酸骨固定材料的研究

用聚乙烯醇(PVA)的二甲基亚砜(DMSO)溶液对水热反应法合成的超细羟基磷灰石(HAP)进行表面改性，用溶液分散复合法分别制备了HAP含量均为0．03g／mE的聚乳酸(PLLA)／HAP和PLIA／HAP-PVA复合物，并经过挤出成型得到φ=5mm的棒材。重点研究了热拉伸取向的拉伸规律及表面改性前后HAP粒子在PLLA基质中的分散情况。结果表明，经PVA改性的HAP粒子在PLLA基质中的分散要明显优于未经改性的HAP粒子。拉伸取向后PLLA／HAP-PVA复合材料的弯曲强度达262MPa。     

Application of an immunosensor for the detection of the β-lactam antibiotic, cephalexin

Public concern surrounding antibiotic contamination in food and food products has made it imperative to develop analytical methods for their detection. Polyclonal antibodies were used in the development of a surface plasmon resonance (SPR)-based inhibition immunoassay for cephalexin. A conjugate consisting of cephalexin-bovine serum albumin (BSA) was immobilized on the dextran gel surface of the sensor chip. Binding/regeneration studies of antibody to immobilized cephalexin were studied and dissociation of the antibody from the immobilized cephalexin was easily achieved with 10 mmol l^-1 NaOH. Forty surface regeneration cycles were carried out and found to be reproducible with only a 7.4% decrease in binding over this number of regenerations. Model inhibition immunoassays for cephalexin were developed in PBS and spiked milk samples with detection ranges of 4.88 to 2,500 ng ml^-1 and 244 to 3,906 pg ml^-1, respectively.     

Corticofugal modulation of the information processing in the auditory thalamus of the cat

Summary Single unit activity of 355 cells was recorded in the auditory thalamus of anesthetized cats before, during, and after the inactivation by cooling of the ipsilateral primary auditory cortex (AI). Most of the units (n = 288) showed similar functional characteristics of firing before and after the cryogenic blockade of AI. The spontaneous firing rate remained unchanged by cooling in 20% of the units and decreased in the majority of them (60%). In some regions, i.e. dorsal division of the medial geniculate body (MGB), lateral part of the posterior group of the thalamus, and auditory sector of the reticular nucleus of the thalamus, the maximum firing rate evoked by white noise bursts was generally affected by cooling in the same direction and to the same extent as the spontaneous activity. Units in the ventral division of MGB showed a characteristic increase of signal-to-noise ratio during cortical cooling. The corticofugal modulation led to the appearance or disappearance of the best frequency of tuning in 51 units and changed it by more than 0.5 octave in 34 units. The bandwidths of different response patterns to pure tones stimulation were used to define a set of functional properties. During cryogenic blockade of AI, two cortically modulated sub-populations of units were usually distinguished that exhibited changes for a given functional property. The complexity and diversity of the effects of cortical inactivation suggest that the corticothalamic projection may be the support for selective operations such as an adaptive filtering of the incoming acoustic signal at the thalamic level adjusted as a function of cortical activity.     

青黛颗粒抗炎、镇痛作用的实验研究

目的 :通过对青黛颗粒抗炎、镇痛作用的实验研究 ,探讨该药治疗溃疡性结肠炎的作用机理。方法 :采用小鼠醋酸扭体法、大鼠棉球肉芽肿法和角叉菜胶所致大鼠足肿胀方法。结果 :青黛颗粒给药高、中、低剂量组和阳性对照药组均明显降低小鼠扭体次数 (P<0 .0 5～P<0 .0 1)。对大鼠棉球肉芽肿和大鼠足肿胀有显著的抑制作用 (P <0 .0 1～P <0 .0 0 1)。结论 :青黛颗粒分别对大鼠具有抗炎、对小鼠具有镇痛作用。且镇痛作用呈量效关系     

Controversies in tuberculosis

Tuberculous infection among children continues to be a significant cause of morbidity. The symptom complex are so variable among children that the final diagnosis often rests on the laboratory tests. Proper interpretation of the tests, specially tuberculin test and radiographic studies, are necessary for establishing correct diagnosis. The usefulness of tuberculin test in both unimmunized and BCG vaccinated children is highlighted. BCG accelerated response as a test should be reserved for identifying serious form of pulmonary disease or CNS tuberculosis when the tuberculin test is negative. Radiographic assessment may be sensitive in some instances but not always specific and hence needs cautious interpretation. Tuberculosis among BCG vaccinated children though not uncommon, needs proper documentation. Current trends in the management of tuberculosis including CNS forms are briefly outlined.     

体表电位标测微机系统(Ⅰ型)

本系统的107个电极中,103个分布于胸、背部,1个为参考电极,1个为V_3,其余用于肢导。本系统除能绘出2、4、8ms任意间隔的103通道同步的体表等电位图,常规12导联和V_(7 9)心电图,胸、背部位的心电图外,还可记录R峰值等电位图,∑R,Q波等电位图,nQ30、40,极大、极小轨迹图等。     

Inflammation and the Aging Process: Devil or Angel

Inflammation is often viewed as a pathologic mechanism leading to tissue damage and interference with function, such as the process of chronic tissue scarring or fibrosis. However, it is important to note that inflammation is a crucial component of normal tissue repair as well as being fundamental to the body's defense against infection. Considering inflammation as a "causative agent in aging" belies the underlying mechanisms whereby the acute inflammatory response is necessary for survival, and efforts to reduce and control the inflammatory response leave the host susceptible to infectious agents and improper healing. Chronic inflammation inevitably has initiating mechanisms that include immune, autoimmune, and metabolic pathways, leading to the activation and presence of the host-protective response. It is more appropriate to target the underlying initiating conditions than the inflammatory process that ensues and treat the basic mechanisms of disease rather than interfere in a very important protective mechanism of the host.     

Prolactin responses to haloperidol in drug-free and treated schizophrenic patients

Summary The prolactin response to 5 mg haloperidol i.m. was studied in 12 schizophrenic patients in a drug-free state and after a month treatment with haloperidol, as a possible index of dopamine receptor sensitivity and occupancy. Blood samples were taken at times 0, 60, 90 and 120 minutes. The increase in PRL observed in the drug-free state disappeared after drug treatment. The PRL plasma levels after treatment with 60 mg haloperidol per os were higher than the maximal PRL responses after 5 mg i.m. The increases in baseline PRL caused by the treatment correlated positively to the reduction in the BPRS score. The test was also performed in a group of 11 patients chronically treated with haloperidol during a daily dose of 60 mg, and 15 days after reduction of the dose to 30 mg. PRL increases after 5 mg haloperidol i.m. were observed only after reduction of the dose. It is suggested that the prolactin response to haloperidol is an index of the occupancy of receptors that are involved in the PRL releasing mechanisms, and could be used to verify their blockade by the neuroleptics, especially in patients that do not respond positively to drug treatment.     

Coronavirus induced primary demyelination: indications for the involvement of a humoral immune response

Coronavirus MHV-JHM infection of rodents can result in demyelinating encephalomyelitis. We analysed histological changes induced by coronavirus MHV-JHM infection in Lewis rats. Besides an acute disease (AE), chronic panencephalitis (CPE) and subacute demyelinating encephalomyelitis (SDE) were induced. These disease types were differentiated by the incubation period, the localization of lesions, the type of tissue damage and distribution of virus antigen. In AE and CPE, virus antigen was detected in neurons, astrocytes and oligodendrocytes, whereas in SDE neurons lacked virus antigen. Viral nucleocapsid protein (N) was present in the cytoplasm and the spike protein (S) was displayed on the surface of infected neural cells. However, expression of S protein relative to N protein was severely impaired in SDE lesions. Quantitative analysis of infiltrating inflammatory cells revealed that the number of macrophages and T cells were similar in lesions of AE, CPE and SDE. In contrast to that, SDE lesions contained a significantly higher number of IgG + B cells and plasma cells. In addition active demyelinating SDE lesions displayed an enhanced IgG content and deposits of complement C9. These results indicate that virus induced primary demyelination could be a consequence of antibody mediated cytotoxicity. Furthermore, a reduction in the number of cells producing spike protein in the chronic forms of the disease indicates down-regulation of this protein, possibly mediated by anti-S antibodies.