大鼠再生肝对二乙基亚硝胺启动作用的敏感性

目的比较再生肝和正常肝对二乙基亚硝胺（ＤＥＮ）启动作用的敏感性。方法以２／３肝叶切除后８周末的大鼠为实验组,正常大鼠为对照组,作如下比较：肝重、常规组织学检查及３Ｈ－ＴｄＲ掺入试验;用修改的Ｓｏｌｔ－Ｆａｒｂｅｒ模型,通过对ＧＧＴ阳性癌前病灶的体视学测量,观察肝脏对ＤＥＮ的启动效应;在体内和体外（无血清原代培养肝细胞）经ＤＥＮ攻击后,以核酸原位缺口标记方法观察肝细胞ＤＮＡ的损伤程度。结果２／３肝叶切除后８周末的实验组肝脏的修复过程已完成,未见肝细胞继续增生的表现;经ＤＥＮ攻击后,实验组肝癌前病灶在数密度和体积密度上都显著高于对照组;无论在体内或体外接受ＤＥＮ攻击后,实验组肝细胞ＤＮＡ的损伤程度都显著大于对照组。结论即使再生过程已经完成,再生肝仍比正常肝具有较高的致癌敏感性,这与再生肝肝细胞在ＤＥＮ攻击后其ＤＮＡ损伤较重相关。     

The nationwide epidemiological study of mental disorders in korea

The lifetime prevalences of DSM-III mental disorders using Korean version of DIS-III are presented. They were studied in 5,100 adults (aged 18 to 65) in household selected by two stage cluster sampling. Comparisons were made between regions, sex and age groups. International comparison with Epidemiologic Catchment Area program was also made.     

Cord blood leucocyte expression of functionally significant molecules involved in the regulation of cellular immunity

The cellular immune system of the newborn infant is immature and hypo-responsive when compared with adults. The extent to which immaturity of the leucocyte function underlies hyporesponsiveness in the newborn is incompletely understood. In this study flow cytometric techniques were applied to investigate the concurrent expression of a range of surface and intracellular leucocyte functional molecules and cytokines in resting and stimulated cord and adult blood. Production of interleukin (IL)-2 and expression of the components of its receptor, IL-2R alpha/beta/gamma, were investigated. No differences in the proportion of leucocytes producing IL-2R alpha and IL-2R gamma were observed for newborns and adults. A lower proportion of T cells and natural killer (NK) cells from newborns expressed IL-2R beta and upregulation of expression was slower. We hypothesize that reduced IL-2R beta may curtail early autocrine IL-2 activation of immune responses in the newborn. This hypothesis was supported by the observation that an increased proportion of stimulated T cells from newborns produced IL-2 at 4 h poststimulation, but at 24 h the proportion was lower than for adult T cells. The very low levels of interferon (IFN)-gamma produced by neonatal T cells and NK cells may also be partly explained by a curtailment of early autocrine activation of T cells. Expression and kinetics of upregulation for other functional molecules were studied. CD71, HLA-DR, tissue factor and CD152 levels were not significantly different for adults and newborns, suggesting that cord blood leucocytes, in some respects, may demonstrate functional maturity. IL-6 secretion by stimulated monocytes was also comparable in cord and adult blood. However, IL-1 alpha and IL-1 beta were produced by a lower proportion of monocytes from newborns than adults. Similarly, tumour necrosis factor (TNF)-alpha production for monocytes and T cells was lower in cord blood. The mean fluorescence intensity for IL-1 alpha, IL-1 beta and TNF-alpha was also lower for leucocytes from cord blood. These findings are significant in relation to the inability of newborn infants to mount a febrile response to infection. The findings of lower expression of IL-2R beta and lower production of inflammatory cytokines IL-1 alpha, IL-1 beta and TNF-alpha is a basis for improved understanding of the immunological immaturity of leucocytes in the newborn.     

Effects of health information in youth on adult physical activity: 20‐Year study results from the Amsterdam growth and health longitudinal study

In the Amsterdam Growth and Health Longitudinal Study (AGAHLS), a group of apparently healthy males and females (n = 200) were interviewed about their physical activities on eight separate occasions over a period of 20 years between 13 and 33 years of age (multi‐measured group: MM). Information about their health was given based on their personally measured lifestyle (activity, diet, smoking) and biological risk characteristics for chronic diseases (medical check‐ups). A comparable group of boys and girls (n = 200) was only measured on two occasions (bi‐measured group: BM): at 13 and 33 years. Physical activity was estimated with a structured interview. Total physical activity and sports activity were estimated in three intensity levels (light, moderate, and heavy). It was hypothesized that the eight repeated medical check‐ups with health information in the MM group would result in a healthier lifestyle with respect to the determinants and levels of habitual physical activity compared to the BM group. Contrary to the hypothesis, males and females in the BM group showed a significantly higher increase or a lower decrease in physical activities compared to the MM group. This negative effect on the physical activity pattern at 33 years in the MM group may have been caused by more underreporting of physical activities than in the BM group. In conclusion, there does not appear to be a significant effect of long‐term (multi‐measured) health information with medical check‐ups during adolescence and young adulthood on level of physical activity in males and females at 33 years of age. Am. J. Hum. Biol. 14:448–456, 2002. © 2002 Wiley‐Liss, Inc.     

Longitudinal relationships between nutritional status, body composition, and physical fitness in rural children of South Africa: The Ellisras longitudinal study.

The objective of this study was to investigate the development and tracking of nutritional status, body composition and physical fitness, and the longitudinal relationship of changes in nutritional status, and body composition with changes in physical fitness over a 1-year period of follow-up. Studied were 380 boys and 322 girls aged 7-14 years from the Ellisras Longitudinal Study. Boys and girls were divided into two groups of pre-adolescence (<11 years) and adolescence (>10 years). High tracking coefficients (>8) were found for nutritional status, body mass index, and fat-free mass, while low tracking coefficients (<4) were found for the sum of skinfolds, fat mass, arm muscle area, and central fat distribution. Moderate and low tracking coefficients were found for the physical fitness items. Longitudinal regression analyses showed that physical fitness performances that require a high energy flux over a short period of time are affected by muscle wasting, whereas having a low body weight appears to be important for a good performance on other fitness items in these malnourished rural South African children.     

Identification of genes differentially expressed in cultured human osteoblasts versus human fibroblasts by DNA microarray analysis

Little is known about patterns of gene expression from cells populating the connective tissues. This study investigated the possible variance of gene expression profile between human osteoblasts (HO) and human fibroblasts (HF) in vitro, using DNA microarray technology. Clustering identification was used to compare expression patterns between HO and HF for biological significance. Our results showed that genes encoding the extracellular matrix or apoptosis-related proteins tended to be expressed in greater abundance in HO, while more proteolysis-related proteins were expressed in higher level in HF. Significant differences in expression were also noted with genes related to signaling pathways. To confirm the array results, three genes (periostin, MFG-E8, MMP-10) were selected and analyzed independently by RT-PCR and northern blot. The results were found consistent with the array data in HO and HF. The present findings suggest that HO and HF differ not only phenotypically but in the expression level of tissue specific genes to assure the turnover and homeostasis of their respective tissues.     

Multifunctional initiation of lactide polymerization by stannous octoate/pentaerythritol

L -Lactide was polymerized with stannous 2-ethylhexanoate (stannous octoate) in the presence of pentaerythritol to investigate multifunctional initiation. The prepared oligomers contain starshaped 4-arm molecules when the mole ratio of [lactide]/[pentaerythritol] is above 32. The molecular weight of oligomers coincides with the [lactide]/[pentaerythritol] ratio, indicating that pentaerythritol in conjugation with stannous octoate is an initiator for the “living” polymerization of L-lactide.     

Association of the CTLA-4 gene with rheumatoid arthritis in Chinese Han population

Cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) is important for downregulation of T-cell activation, and CTLA-4 gene polymorphisms have been implicated as risk factors for rheumatoid arthritis (RA). Previous studies of the association between the +49 polymorphism of the CTLA-4 gene in RA have provided conflicting results. In order to determine association of the CTLA-4 gene with RA in Chinese Han population, we used denaturing gradient gel electrophoresis (DGGE) to genotype polymorphisms of four SNPs (MH30, +49, CT60 and JO31) of the CTLA-4 gene in 326 RA patients and 250 healthy controls. Furthermore, meta-analysis of all available studies relating +49 polymorphism to the risk of RA was performed to confirm the disease association. Among the SNPs examined, the genotype frequencies of CTLA-4 +49 and CT60 in RA patients differed significantly from controls (P=0.028 and 0.007). In addition, the distribution of four haplotypes constructed by these two SNPs was significantly different between patients and controls (chi(2)=10.58, d.f. =3, P=0.014). The meta-analysis also revealed that in both European and Asian populations, the CLTA-4 +49 G allele was associated with the risk of RA. These results suggested that the CTLA-4 gene might be involved in the susceptibility to RA in the Chinese Han population and both +49 and CT60 of CTLA-4 gene might be the causal variants in RA disease.     

Procoagulant activity and thrombelastography in korean hemorrhagic fever

Twenty male patients with Korean hemorrhagic fever were evaluated with thrombelastography (TEG) to assess the changes in coagulation system, and the results were compared with those of conventional coagulation tests. Procoagulant activity in the plasma was determined by comparing the reaction time "r" of the normal plasma and that of the mixture of equal parts of the normal plasma and the patient's plasma. The TEG was found to be a useful measure of the changes in the coagulation profile, and provided instant accurate assessment of the patient's hemostatic function. Presence of the procoagulant activity was demonstrated in the plasma of the patients and indicated occurrence of active intravascular coagulation during the early stage of the disease.     

MR demonstration of cryptic vascular malformation producing a palatal myoclonus--a case report

A 47-year-old man had suffered oscillopsia associated with palatal myoclonus for 10 years. High-field magnetic resonance imaging (MRI) revealed a cryptic vascular malformation within the "Guillain-Mollaret triangle" which was thought to be the responsible lesion.