2009 Vol. 22, No. 5
Gene Expression Profile of Human Skeletal Muscle and Adipose Tissue of Chinese Han Patients with Type 2 Diabetes Mellitus
2009, 22(5): 359-368.
Objective To study the differential patterns of gene expression in skeletal muscle and adipose tissue between type 2 diabetes mellitus (T2DM) patients and healthy subjects using DNA microarray analysis. Methods T2DM patiens were divided into female group, young male group and old male group. DNA microarray analysis and quantitative real-time PCR were carried out to analyze the relation between gene expressions and T2DM. Results The mRNA expression of 298, 578, and 350 genes was changed in the skeletal muscle of diabetes mellitus patients compared with control subjects. The 1320, 1143, and 2847 genes were modified in adipose tissue of the three groups. Among the genes surveyed, the change of 25 and 39 gene transcripts in skeletal muscle and adipose tissue was ≥2 folds. These differentially expressed genes were classified into 15 categories according to their functions. Conclusion New genes are found and T2DM can be prevented or cured.
Correlation of Serum Leptin Level with Bone Mineral Density and Bone Turnover Markers in Chinese Adolescent Dancers
2009, 22(5): 369-373.
Objective To investigate plasma leptin concentrations in adolescent female dancers and to determine whether leptin has some effects on their bone mineral density (BMD) and bone turnover markers. Methods Sixty dancers aged 15-17 years and 77 healthy controls were enrolled in the study. Bone mineral density (BMD) and body composition were detected by dual energy X-ray absorptiometry. Serum leptin concentrations were measured by radioimmunoassay (RIA). Two bone turnover markers, bone-specific alkaline phosphatase (BAP) and tartrate-resistant acid phosphatase(TRACP), were determined by ELISA. Results The dancers had a lower fat mass and a lower leptin level than the controls, while they had a relatively higher BMD of the total body and legs after adjustment for BMI and age. The levels of bone resorption and formation of markers were higher in the dancers than in the controls. Leptin was positively correlated with BMI, body weight, fat mass, and percentage of body fat. In dancers, Leptin was positively correlated with the BMD of the total body and the left leg. However, after adjustment for BMI, no correlation of serum leptin concentrations with BMD values was found in either dancers or controls. Nor correlation was found between leptin and bone turnover markers after adjustment for BMI. Conclusion The leptin profile is different between the controls and the dancers with a lower BMI and a lower fat mass. Circulating plasma leptin level depends on BMI and is not a direct determinant of BMD in Chinese adolescent dancers.
2009, 22(5): 374-380.
Objective To investigate and compare the effect of radio-frequency (RF) field exposure on expression of heat shock proteins (Hsps) in three human glioma cell lines (MO54, A172, and T98). Methods Cells were exposed to sham or 1950 MHz continuous-wave for 1 h. Specific absorption rates (SARs) were 1 and 10 W/kg. Localization and expression of Hsp27 and phosphorylated Hsp27 ((78) Ser) (p-Hsp27) were examined by immunocytochemistry. Expression levels of Hsp27, p-Hs27, and Hsp70 were determined by Western blotting. Results The Hsp27 was primarily located within the cytoplasm, p-Hsp27 in both cytoplasm and nuclei of MO54, A172, and T98 cells. RF field exposure did not affect the distribution or expression of Hsp27. In addition, Western blotting showed no significant differences in protein expression of Hsp27 or Hsp70 between sham-and RF field-exposed cells at a SAR of 1 W/kg and 10 W/kg for 1 h in three cells lines. Exposure to RF field at a SAR of 10 W/kg for 1 h slightly decreased the protein level of phosphorylated Hsp27 in MO54 cells. Conclusion The 1950 MHz RF field has only little or no apparent effect on Hsp70 and Hsp27 expression in MO54, A172, and T98 cells.
Inhibitory Effect of Estrogens, Phytoestrogens, and Caloric Restriction on Oxidative Stress and Hepato-toxicity in Aged Rats
2009, 22(5): 381-387.
Objective To investigate the protective effect of 17β-estradiol (E2), peganum harmala extract (PHE) administration and calorie restriction (CR) treatment (60%) on oxidative stress and hepato-toxicity in aged rats. Methods Eighteen months old animals that were treated at the age of 12 months were divided into 4 groups: normal control group with free access to food, E2 treatment group, PHE treatment group and CR treatment group of the food given to control group. Six male rats at the age of 4 months were used as a reference group. Results Aging significantly decreased superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX), and increased lactate deshydrogenase (LDH), gamma-glytamyl transferase (GGT), phosphatase alkalines (PAL), aspartate and lactate transaminase (AST and ALT) activities in the liver. Aging also induced an increased lipid peroxidation level, histological changes and a decreased E2 level. However, treatment with E2, PHE, and CR increased 17β-estradiol, and decreased hepatic dysfunction parameters and lipid peroxidation as well as histological changes in the liver of aged rats. Conclusion The antioxidant and hepatoprotective activity of PHE and CR is possibly attributed to its ability to increase E2 level, which as an antioxidant, acts as a scavenger of ROS. Further studies on the pharmaceutical functions of E2 in males may contribute to its clinical application.
2009, 22(5): 388-393.
Objective To elevate the immunological effect of subunit influenza vaccine in infants and aged people (over 60) using liposomal adjuvant in the context of its relatively low immunity and to investigate the relation between vaccine antigens and liposomal characteristics. Methods Several formulations of liposomal subunit influenza vaccine were prepared. Their relevant characteristics were investigated to optimize the preparation method. Antisera obtained from immunizinged mice were used to evaluate the antibody titers of various samples by HI and ELISA. Results Liposomal trivalent influenza vaccine prepared by film evaporation in combinedation with freeze-drying significantly increased its immunological effect in SPF Balb/c mice. Liposomal vaccine stimulated the antibody titer of H3N2, H1N1, and B much stronger than conventional influenza vaccine. As a result, liposomal vaccine (mean size: 4.5-5.5 μm, entrapment efficiency: 30%-40%) significantly increased the immunological effect of subunit influenza vaccine. Conclusion The immune effect of liposomal vaccine depends on different antigens, and enhanced immunity is not positively correlated with the mean size of liposome or its entrapped efficiency.
Analysis of Translocation of the CagA Protein and Induction of a Scattering Phenotype in AGS Cells Infected with Heficobacter pylori
2009, 22(5): 394-400.
Objective To investigate whether the presence of structured CagA proteins in Western- and Eastern-type Helicobacter pylori (H. pylori) induces different incidences of gastric diseases. Methods CagA and phosphorylatd CagA were expressed in AGS gastric epithelial cells infected with wild type and mutant strains. The ability of individual CagA was determined by immunoprecipitation and Western blot assay. Morphological changes of these cells were observed under microscope to evaluate the appearance of elongation hummingbird phenotype. Results The sizes of CagA proteins in different strains were different, and no phosphorylated CagA proteins were detected in wild-type strains. Meanwhile, the kinetics of CagA status in AGS infected with H. pylori was detected. The molecular weight of phosphorylated CagA with the same size of CagA proteins in H. pylori was different in infections with different wild-type strains. CagA and phosphorylated CagA increased in a time-dependent manner after the infection. The hummingbird phenotype with H. pylori for time-course was observed under microscope. Instead of HPK5 strain, the wild-type 26695 strain induced hummingbird phenotype in a time-dependent manner. Conclusion Translocation and phosphorylation of CagA are necessary, but not sufficient, for the induction of hummingbird phenotype in AGS cells.
Antibiotic Resistance of Probiotic Strains of Lactic Acid Bacteria Isolated from Marketed Foods and Drugs
2009, 22(5): 401-412.
Objective To identify the antimicrobial resistance of commercial lactic acid bacteria present in microbial foods and drug additives by analyzing their isolated strains used for fermentation and probioties. Methods Antimicrobial susceptibility of 41 screened isolates was tested with disc diffusion and E-test methods after species-level identification. Resistant strains were selected and examined for the presence of resistance genes by PCR. Results Distribution of resistance was found in different species. All isolates were susceptible to chloramphenicol, tetracycline, ampicillin, amoxicillin/clavulanic acid, cephalothin, and imipenem. In addition, isolates resistant to vancomycin, rifampicin, streptomycin, bacitracin, and erythromycin were detected, although the incidence of resistance to these antibiotics was relatively low. In contrast, most strains were resistant to ciprofloxacin, amikacin, trimethoprim/sulphamethoxazole, and gentamycin. The genes msrC, vanX, and dfrA were detected in strains of Enterococcus faecium, Lactobacillus plantarum, Streptococcus thermophilus, and Lactococcus lactis. Conclusion Antibiotic resistance is present in different species of probiotic strains, which poses a threat to food safety. Evaluation of the safety of lactic acid bacteria for human consumption should be guided by established criteria, guidelines and regulations.
Comparison of Changes in Body Composition during Puberty Development of Obese and Normal-weight Children in China
2009, 22(5): 413-418.
Objective To compare the changes in body composition, including fat mass index (FMI) and fat free mass index (FFMI) during puberty development of obese and normal-weight children in China, and to explore the effect of age and gender on body composition. Methods A total of 356 children at the age of 7-15 years were enrolled in this study. Body composition of 10 normal-weight and obese children in each age group was measured by dual-energy x-ray absorptiometry (DEXA). FFMI and FMI were calculated according to the following formula: FFMI (kg·mT~(-2))= FFM(kg) / height~2 (m~2) and FMI (kg· m~2)= FM (kg) / height~2 (m~2). Results The fat mass and fat free mass of obese children were significantly higher than those of normal-weight children (P＜0.05). The FMI and FFMI of obese children increased significantly with age and were higher than those of the same sex, gender, and age normal-weight children (P＜0.05). Conclusion The levels of fat mass, fat free mass, FMI, and FFMI are different in obese and normal-weight children, and gender effects are significant in boys having higher levels of these indicators than in girls. FFMI and FMI can be used as monitoring indexes in weight control of obese children.
2009, 22(5): 419-422.
Objective To explore the potential reporter gene assay for the detection of sodium channel-specific toxins in shellfish as an alternative for screening harmful algal bloom (HAB) toxins, considering the fact that the existing methods including HPLC and bioassay are inappropriate for identifying HAB toxins which poses a serious problem on human health and shellfish industry. Methods A reporter plasmid pEGFP-c-fos containing c-fos promoter and EGFP was constructed and transfected into T24 cells using LipofectAMINE 2000. Positive transfectants were screened by G418 to produce a pEGFP-c-fos-T24 cell line. After addition of increasing neurotoxic shellfish poison (NSP) or GTX2,3, primary components of paralytic shellfish poison (PSP), changes in expression of EGFP in the cell line were observed under a laser scanning confocal microscope and quantified with Image-pro Plus software. Results Dose-dependent changes in the intensity of green fluorescence were observed for NSP in a range from 0 to 10 ng/mL and for GTX 2,3 from 0 to 16 ng/mL. Conclusion pEGFP-c-fos-T24 can be applied in detecting HAB toxins, and cell-based assay can be used as an alternative for screening sodium channel-specific HAB toxins.
Lipid Peroxidation and Ultrastructural Modifications in Brain after Perinatal Exposure to Lead and/or Cadmium in Rat Pups
2009, 22(5): 423-429.
Objective To assess lipid peroxidation and ultrastructural modifications in rat brains following perinatal exposure to lead (Pb) and/or cadmium (Cd). Methods Female rats were divided into four groups: control group, Pb (300 mg/L) group, Cd group (10 mg/L) and Pb+Cd (300 mg/L, 10 mg/L) group. The compounds were delivered in the drinking water throughout pregnancy and lactation. Results The levels of compounds in blood and brain of the Pb+Cd group were similar to those of other groups, but the effects of Pb+Cd on pups' body and brain weights were higher than on other compounds. Electron microscopy revealed that Pb and Cd had effects on mitochondrial swelling, disruption and cristae loss, Nissl body dissolution, degenerated organelles and vacuoles, cytomembrane disappearance, and nuclear ehromoplasm concentration. The activity of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), catalase (CAT), acetylcholinesterase (ACHE) was decreased, whereas the activity of maleic dialdehyde (MDA) was increased. Conclusion Perinatal exposure to low doses of Pb and Cd can produce alterations in lipid peroxidation and ultrastructural modifications in rat brains, and exposure to both metals can result in greater damages.
2009, 22(5): 430-441.
Objective To evaluate the impact of major causes of death on changes of life expectancy in China. Methods Life expectancy was calculated by standard life table techniques using mortality data from the national censuses in 1990 and 2000 and the 1% National Population Sampling Surveys in 1995 and 2005. Mortality data about the major causes of death from VR-MOH were used as reference values to estimate their death proportions of the specific age groups by sex and regions, as well as all-cause mortality and age-specific mortality rates of major causes of death. Decomposition method was used to quantitatively evaluate the impact. Results Three key findings were identified in our study. First, China's health challenge was shifted from diseases related to living conditions to those related to behavior and lifestyle, with rural areas relatively lagged behind urban areas. Second, the impacts of cardiovascular diseases and neoplasm on the middle aged and elderly population were stressed. Third, compared to the urban population, the rural population tended to have increasing mortality of neoplasm and cardiovascular diseases, especially in adults at the age of 15-39 years. Conclusion Further efforts should be made to reduce the incidence of neoplasm and cardiovascular diseases, especially in rural areas, by promoting healthy behavior and lifestyle and providing appropriate therapies for all patients in need.
Perilipin Gene 1237 T＞C Polymorphism is not Associated with Obesity Risk in Northern Chinese Han Adults
2009, 22(5): 442-447.
Objective To identify the association between PLIN 1237 polymorphism and obesity in Chinese Han adults. Methods A total of 994 adults (157 obese subjects, 322 overweight subjects, and 515 normal controls) were recruited from two rural communities. PLIN 1237 polymorphism was genotyped by polymerase chain reaction-restriction-fragment-length-polymorphism (PCR-RFLP). Association between PLIN polymorphisms and obesity status was estimated by ordinal logistic regression. Results The three genotypes of PLIN 1237 were detected with a percentage of 54.3%, 37.1%, and 8.6% in TT, TC, and CC genotypes, respectively. For the PLIN 1237 polymorphism locus, the frequency of alleles T and C was 0.73 and 0.27, respectively. The PLIN 1237 polymorphisms were in Hardy-Weinberg equilibrium. PLIN 1237 polymorphism was not associated with obesity. The odds ratio for overweight or obesity for the CC+TC genotype was 0.8 (0.4, 1.4) in women (P=0.4) and 0.6 (0.3, 1.3) in men (P=0.2) after adjustment for age, education, household income and alcohol consumption, smoking, and physical activity. Conclusion Chinese Han adults have a lower frequency of variant-allele C in PLIN 1237. PLIN 1237 T＞C polymorphism is not significantly associated with obesity in northern Chinese adults.