睡眠剥夺对内隐记忆的影响

目的:探讨不同时间睡眠剥夺(sleep deprivation,SD)对内隐记忆的影响。方法:将32名青年男性随机分为4组:对照组、SD21、SD45和SD69组,每组8名。采用补笔测验和组词测验对4组被试进行测试。结果:SD 后无论知觉启动还是语义启动,启动量降低,并随SD 时间延长而减少。同一组内,两种测验进行比较,除对照组外,其他SD 组两两比较,语义启动的启动量大于知觉启动(P<0.05)。知觉启动中,SD45同SD69 相比无显著差异(P=0.245),其他两两比较差异均有统计学意义(P<0.01);语义启动中,SD21同对照组相比差异无统计学意义(P=0.316),其他两两比较差异均有统计学意义(P<0.01)。结论:SD 后内隐记忆受损,并同SD 时间有关;SD 后语义启动和知觉启动出现分离,知觉启动更受SD 影响。     

Effect of pregnancy on proteoglycan-induced progressive polyarthritis in BALB/c mice: remission of disease activity

Proteoglycan-induced arthritis is a murine autoimmune model displaying many similarities to human rheumatoid arthritis and ankylosing spondylitis, as has been documented by clinical, immunological and histopathological studies. Since the onset of arthritis correlates with the serum antibody level to mouse cartilage proteoglycan (PG), it is believed that these autoreactivc antibodies may play crucial roles in the pathological mechanisms of PG-induced arthritis. We have found that fertility in these PG-induced arthritic mice had been reduced but, unlike collagen-induced arthritis, had not been completely lost. Moreover, pregnancy had a beneficial effect upon the clinical symptoms with very little or no influence on scrum antibody levels. Although fertility was retained and arthritic mothers delivered healthy offspring, the birth frequency was significantly less than in non-arthritic age-matched controls. Furthermore, the presence of anti-PG autoantibodies (predominantly IgG1 subclass) transmitted from arthritic mothers to infants transplacentally and by milk during the lactation period did not render these offspring either resistant or more sensitive to subsequent induction of arthritis. Subsequent immunization of infants with ‘arthritogenic’ PG revealed an unaltered susceptibility to arthritis induction.     

Effect of Insulin on NO Production by Monocytes from Patients with Metabolic Cardiovascular Syndrome

Parameters of NO metabolism in the gingiva were studied during experimental periodontitis accompanied by alloxan diabetes and exogenous hypercholesterolemia. We measured activities of inducible and constitutive NO synthase and concentrations of stable NO end metabolites in rat gingival tissue (total contents of nitrite and nitrate). Under pathological conditions NO metabolism significantly differed from the control. Treatment with mexidol for 14 days significantly decreased activity of inducible NO synthase in the gingiva of experimental animals. __________ Translated from Byulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 140, No. 10, pp. 384–386, October, 2005     

Sequential Measurements of Chemokines in Urosepsis and Experimental Endotoxemia

Chemokines are a superfamily of small chemotactic proteins. While increased levels of interleukin-8 have been measured in serum and urine during urinary tract infection, little is known about other chemokines in this condition. Monocyte chemoattractant protein (MCP)–1, macrophage inflammatory protein (MIP)–1, MIP-1 and interferon- inducible protein (IP)–10 were measured in 30 patients with culture-proven urosepsis during a 3-day follow-up and in 11 healthy humans after intravenous injection of endotoxin (4 ng/kg). Urine and serum levels of MCP-1, MIP-1, and IP-10, but not of MIP-1, were elevated in patients on admission, and decreased after initiation of antibiotic treatment. Endotoxin administration to healthy subjects induced increases in plasma and urine concentrations of all four chemokines. These data indicate that clinical and experimental gram-negative infection in humans is associated with enhanced production of chemokines that act mainly on mononuclear cells and that these chemokines are at least in part locally produced.     

Integrated medical informatics with small group teaching in medical education

National Taiwan University College of Medicine (NTUCM) introduced small groups of teaching and basic-clinical integrated courses for medical students in 1992. By using computer network and multimedia techniques, this study tried to overcome barriers to learning in small group teaching. The Department of Medical Informatics of NTUCM established campus networking and computer classrooms and provided Internet and intranet network services including mail, netnews, bulletin board systems (BBS), world wide web (WWW), gopher, ftp and local file servers. To implement an interactive learning environment, the authors first tried mail lists, newsgroups and BBS. Next an integrated learning system prototype on the WWW was developed to provide functions including online syllabus, discussion boards simulated to BBS, online talk, interactive case studies, virtual classroom with video on demand (VOD) and Internet medical resources. The results showed that after the medical students completed the required course of medical informatics and had good network access using a network to communicate with each other became a daily practice. In the future, the system will extend to the tutoring of clinical practice and continuing medical education. The authors expect a national medical education network and more international cooperation and exchange.     

Cell surface laminin-like substances and laminin-related carbohydrates of rat ascites hepatoma AH7974 and its variants with different lung-colonizing potential

Rat ascites hepatoma AH7974 cells strongly expressed antilaminin antibody-reactive substances (laminin-like substances) andGriffonia simplicifolia isolectin B4 (GS)-reactive carbohydrate (alpha)-d-galactose; alpha-Gal) on their cell surface. The alpha-Gal expression was not apparently influenced by the pretreatment of cells with methanol. The cell membrane laminin-like substances had approximate molecular weights of 150, 62 and 56 kDa in denaturating reducing conditions, of which the 62 and 56 kDa bands were stained with GS. The cell membrane molecules bearing alpha-Gal were 62 and 56 kDa and were stained with antilaminin antibody. Therefore, the major molecules bearing alpha-Gal residues of AH7974 cell membrane are considered to be laminin-like substances. To determine the role of the substances in metastasis, we selected four cell lines (74AD, 74AD-f, 74FL, 74FL-a) from AH7974 in culture. 74AD and 74FL-a are adherent lines and 74AD-f and 74FL are floating lines. All of these cell lines strongly expressed laminin-like substances, but a marked difference was found in expression of alpha-Gal, which was most strongly expressed by 74FL, followed by 74AD, and rarely by 74AD-f and 74FL-a; the staining intensity was positively correlated with their experimental lung-colonizing potential. Cell membrane laminin-like substances were 200, 97, 62, 56 and 46 kDa and among them 62 and 56 kDa molecules were glycosylated with alpha-Gal. The pretreatment of 74FL cells with antilaminin antibody or with human type A serum (containing natural antibody to alpha-Gal epitope) depressed remarkably the lung-colonizing potential of the cells. These results suggest that the expression of 62 and 56 kDa laminin-like substances with alpha-Gal residues on tumor cell surfaces is one of the determinants associated with lung-colonizing potential of these cells.     

重组人bFGF的原核表达及其高效价抗血清的制备

目的 以重组人碱性成纤维生长因子为免疫原，制备高效价抗hbFGF抗血清。方法通过PCR方法改造5’编码区的12个密码子，构建hbFGF’原核表达载体并在大肠杆菌(E．coli)中表达，以纯化的hbFGF、免疫新西兰兔，制备高效价抗血清，用于重组hbFGF、的免疫印迹分析。结果经过改造的hbFGF基因在E．coli中获得较高水平表达。从可溶性部分纯化得到纯度95％以上的重组hbFGF，以该重组蛋白免疫兔子，在二次加强后以间接ELISA检测抗血清效价可达1：512000。免疫印迹分析显示该抗血清与E．coli中表达的重组hbFGF、和标准hbFGF、均有特异性反应，但与某些细菌蛋白存在弱交叉反应，经E．coli菌体蛋白吸附的抗血清，与菌体蛋白的弱交叉反应消失。结论以纯化的重组hbFGF为免疫原制备了高效价的特异性抗血清，经菌体蛋白吸附可消除存在的交叉反应性。     

Correlation between cyclophosphamide-induced viral susceptibility and depletion of Junin virus-induced suppressor populations.

In contrast to lymphocytic choriomeningitis virus, another arenavirus, Junin virus (JV), the etiologic agent of Argentine hemorrhagic fever, when inoculated into suckling mice, induces lethal meningoencephalitis characterized by a delayed-type hypersensitivity (DTH)-like immune response. However, the adult BALB/c mouse is resistant to infection and no DTH reaction can be seen. This different viral sensitivity may be related to the development of an antigen non-specific DTH-suppressor cell pathway at work in the adult mouse. When the resistant mice are treated with cyclophosphamide (Cy) (50 mg/kg each dose) given at days -1,+1,+4 (zero: infection day), animals become susceptible and develop DTH reaction in brain that leads to death. We analyze the influence of the timing of Cy administration on the suppressor system developing after infection. It was found that Cy depletes the previously described JV-induced suppressor populations (Tsv) but a new suppressor cell (Tsv*) is disclosed bearing the Thy 1+ Ly1+2- phenotype which is unable to depress DTH in Cy-treated animals. With only two doses of Cy corresponding to days -1 and +1, the target of Tsv* cells is depleted but the third dose is still required to achieve full depletion of Tsv cells which are able to employ the Cy-resistant antigen-specific suppressor cells as targets. Since the Cy treatment is able to deplete the Tsv population together with the target of Tsv* cells, animals became unable to regulate lethal DTH reaction. Thus, a cellular explanation for an empirically established Cy schedule able to abrogate the adult mouse resistance to JV is proposed.     

Early stage of human adenovirus type 12-inoculated retinal tissue of F344 newborn rat

To elucidate the pathogenesis of adenovlrus type 12 (Ad12)-induced rat retinal tumor, an experimental animal model of human retinobiastoma (RB), DNA analysis, in situ hybridizatlon and immunohistochemlstry were performed. The adenovirus oncogene EIA was detected in the host genome by Southern blot hybridization. Examined retinal tlssues did not show any histological changes, but the number of retinal cells lmmunoreactive with an antibody to proliferating cell nuclear antigen (PCNA) increased with the course of study. In in situ hybridization, E1A gene expression was recognized at the Inner granular layer of the retina at an early stage arer virus inoculation, and subsequently, N-myc gene expression was recognized at the same region. No alteration was found in the retinoblastoma susceptibility gene ( Rb gene) expression. The product of the virus oncogene integrated into the host genome could induce an Increase in N-myc expression, without any abnormality of the Rb gene itself. Results from the present study could be useful in clarifying the tumorige-nesis of this experimental model.     

Transition from Film to Electronic Media in the First-Year Medical School Gross Anatomy Lab

For the benefit of the first-year gross anatomy students, we digitized and published on a Web site images that had been collected over a 30-year period. We provided a CD-ROM (compact disk, read-only media) containing the image set in higher quality format to students and faculty. We supplemented basic images with hot topics such as CT angiography, virtual colonography, computer-aided diagnosis, and 3D post-processing. Full motion video and moving JPEG (Joint Photo Expert Group) animations were integrated into the atlas. On the post course questionnaire medical students reported that the images on CD-ROM were helpful during the course and for review prior to examinations. Faculty and medical students used the CD-ROM for problem-based learning sections and facilitator training. The images were clear and easily projected during review sessions and were useful for the small group sessions, where they served as examples of normal anatomy.