2002 Vol. 15, No. 4
Changes in Dietary Patterns and Certain Nutrition-related Diseases in Urban and Rural Residents of Jiangsu Province, China, During the 1990s
2002, 15(4): 271-276.
Objective To investigate into the changes of dietary patterns and their impacts on health of urban and rural residents in Jiangsu Province, China during the 1990s. Methods On the basis of the results of food consumption survey, the calorie intake was calculated according to the balanced diet method and the quality of diet was assessed by scores of desirable dietary pattern (DDP).Results It was found that food consumption and dietary patterns changed remarkably during the 1990s. Grain consumption was decreasing year by year, but the consumption of animal food was markedly increasing. Although the score of desirable dietary pattern (DDP) in urban residents was more than 90, the deducted score due to over-consumption of animal food increased. The mortality from infectious diseases evidently decreased in the whole province, while the death rates of some chronic diseases, such as diabetes, hypertension, colorectal cancer and breast cancer, were increasing rapidly in urban areas. Conclusions Sufficient attention should be paid to the negative effects of change in dietary patterns on people's health, especially in the urban residents.
Intake of Volatile N-nitrosamines and Their Ability to Exogenously Synthesize in the Diet of Inhabitants from High-risk Area of Esophageal Cancer in Southern China
2002, 15(4): 277-282.
Objective Nan'ao County in Guandong Province is a high-risk area of esophageal cancer in Southern China. Of the suspected etiological factors in the environment, N-nitrosamines and their precursors have received the greatest attenfion. Methods Sixty samples of the diet ingested by the inhabitants were collected and detected for volatile N-nitrosamines and their precursors. Five Nnitrosamines detected by Gas Chromatography-Thermal Energy Analyzer were N-nitrosodimethylamine, N-nitrosodiethylamine, N-nitrosopyrrolidine, N-nitrosopiperidine and N-ditrosomethyl-benzylamine. Results The average content of 5 volatile N-nitrosamines in the diet was 312.0 μg/kg (median). The daily intake of the nitrosamines was 286.5 μ tg/head/day. Only the ability to exogenously synthesize N-nitrosopiperidine was powerful among 5 volatile N-nitrosamines. By a computerized stepwise regression analysis and curve fitting, we studied the correlation among the nitrosamines, the precursors and the major food items in the samples. Conclusion It demonstrated that a relatively high content of volatile N-nitrosamines was present in the diet collected in the area.
Study of Low-intensity 2450-MHz Microwave Exposure Enhancing the Genotoxic Effects of Mitomycin C Using Micronucleus Test and Comet Assay in vitro
2002, 15(4): 283-290.
Objective To determine the interaction between 2450-MHz microwaves (MW) radiation and mitomycin C (MMC). Methods The synergistic genotoxic effects of low-intensity 2450-MHz microwave and MMC on human lymphocytes were studied using single cell gel electrophoresis (SCGE) assay (comet assay) and cytokinesis-blocked micronucleus (CBMN) test in vitro. The whole blood cells from a male donor and a female donor were either only exposed to 2450-MHz microwaves (5.0 mW/cm2) for 2 h or only exposed to MMC (0.0125 μg/mL, 0.025 μg/mL, 0.05 μg/mL and 0.1 μg/mL) for 24 h; and the samples were exposed to MMC for 24 h after exposure to MW for 2 h. Results In the comet assay, the comet lengths ( 29.1 μm and 25.9 μm) of MW were not significantly longer than those (26.3 μm and 24.1 μm) of controls (P＞0.05). The comet lengths (57.4 μm, 68.9 μm, 91.4 μam, 150.6 μm and 50.6 μm, 71.7 μm, 100.1 μm, 145.1 μm) of 4 MMC groups were significantly longer than those of controls (P＜0.01). The comet lengths (59.1 μm, 92.3 μm, 124.5 μm, 182.7 μm and 57.4 μm, 85.5 μm, 137.5 μm, 178.3 μm) of 4 MW plus MMC groups were significantly longer than those of controls too (P＜0.01). The comet lengths of MW plus MMC groups were significantly longer than those of the corresponding MMC doses (P＜0.05 or P＜0.01) when the doses of MMC were ≥0.025 μg/mL. In the CBMN, the micronucleated cell (MNC) rates of MW were 5‰ and 6‰,which showed no difference compared with those (4‰ and 4‰) of controls (P＞0.05). The MNC rates of 4 MMC groups were 8‰, 9‰, 14‰, 23‰ and 8‰, 8‰, 16‰, 30‰ respectively. When the doses of MMC were ≥0.05 μg/mL, MNC rates of MMC were higher than those of controls (P＜0.05).MNC rates of 4 MW plus MMC groups were 12‰, 13‰, 20‰, 32‰ and 8‰, 9‰, 23‰, 40‰.When the doses of MMC were ≥0.05 μg/mL, MNC rates of MW plus MMC groups were much higher than those of controls (P＜0.01). MNC rates of 4 MW plus MMC groups were not significantiy higher than those of the corresponding MMC doses. Conclusion The low-intensity 2450-MHz microwave radiation can not induce DNA and chromosome damage, but can increase DNA damage effect induced by MMC in comet assay.
2002, 15(4): 291-297.
Objective To test the effect of television viewing on pediatric obesity in urban China.Methods Stratified multistage cluster random sampling method was used for subjects selection.Nine thousand three hundred and fifty-six children, as well as their parents, were investigated. Questionnaire survey was used for data collection. Children's weights and heights were measured in the clinic of the investigated kindergartens or schools by trained investigators following the standardized procedure. Results The percentages of children and adolescents who watched television less than 1 h, 1-2 h, 2-3 h and more than 3 h daily were 32.5%, 46.0%, 15.4% and 6.1%, respectively, while the prevalence of obesity was 10.9%, 11.8%, 13.2% and 15.1%, respectively. Each hourly increment of television viewing was associated with 1%-2% increase in the prevalence of obesity. Conclusions Time spent watching television is directly related to an increase risk of obesity, television viewing time is an independent factor for pediatric obesity.
2002, 15(4): 298-305.
Objective To evaluate the possible role of environmental exposure to lead as a risk factor for prostate pathology in patients suffering from prostate cancer (PCA) and benign prostate hyperplasia (BPH). Methods Blood lead (BPb) level was determined in PCA and BPH cases using a graphite furnace Atomic Absorption Spectrophotometer and compared with those in a control group living in the similar socioeconomic environment. Results BPb was significantly higher in PCA and BPH cases than in normals (P＜0.05). Blood levels of zinc and copper were significantly lower in PCA and BPH cases when compared with controls (P＜0.05). In all the three groups, a statistically significant positive correlation between lead and thiobarbituric acid reactive substances (TBARS) measured as malondialdehyde, and negative correlation between blood lead and antioxidant GSH level, indicative of possible generation of reactive oxygen species, were also observed after adjusting for age as a possible confounders. However, positive association between blood lead and TBARS was relatively higher in PCA patients (r=0.77, P＜0.05) than in BPH (r=0.32, P＜0.05) and normal (r=0.30, P＜0.05).Conclusion These results with limited power seem to suggest for the first time that environmental exposure of aging males to lead may be a risk factor for prostate cancer and/or benign prostate hyperplasia possibly through generation of reactive oxygen species and/or reducing the level of zinc which acts as a cellular growth protector.
2002, 15(4): 306-314.
Obiectives To study the mineralization of 2,4-D in clay and clay loam Egyptian soils under subtropical conditions over a period of 90 d. Methods Using 14C-ring labelled pesticide, laboratory studies under aerobic and anaerobic conditions were conducted. 14C-activity in solutions was directly determined by liquid scintillation counting. Unextractable soil residues were determined by combustion.The nature of methanolic 14C-residues was determined by thin layer and high performance liquid chromatographic analysis. Results Under aerobic conditions 10%-14% of applied dose was mineralized during 90 d irrespective of soil type. The soil extractable pesticide residues decreased with time and the bound residues gradually increased. The highest binding capacity of about 26%-29% was observed in clay soil under aerobic conditions after 90 d. A good balance sheet was obtained and the percentage recovery was generally between 91% and 100%. Conclusion The mineralization of 2,4-D in clay soil was higher than that in clay loam soil under anaerobic conditions.Under aerobic conditions, the soil type had no influence on mineralizaion capacity of 2,4-D during 90 d. The soil binding increased with time whereby the extractable 14C-residues simultaneously decreased.Chromatographic analysis of the methanol extractable 14C-residues of soils revealed the presence of 2,4-D as a main product together with 2,4-dichlorophenol.
Effect of Dietary Administration of Lathyrus sativus Pulse on Intestinal Biochemical Parameters in Normal and Scorbutic Guinea Pigs
2002, 15(4): 315-322.
Objective In order to investigate that ascorbic acid deficiency is responcible for lathyrus toxicity, the effect of dietary feeding of lathyrus pulse in normal and scorbutic guinea pigs for 3 months, on intestinal biochemical parameters was undertaken. Methods The intestinal brush border membrane (BBM) marker and xenobiotic metabolising enzymes (XME) were assayed. Results Exposure to 80% lathyrus alone and in scorbutic conditions showed significant inhibition of alkaline phosphatase (28%-30%), sucrase (19%) and γ-glutamyl transpeptidasc (GGT) (15%-27%)enzymes, while Ca2+-Mg2+-ATPase was significantly inhibited (38%) in scorbutic plus lathyrus treated group. The phase Ⅰ XME (AHH) remained unchanged while the phase Ⅱ enzyme glutathioneS-tranferase (GST) was significantly decreased (20%-22%) in lathyrus and scorbutic plus lathyrus treated groups. Quinone reductase (QR) activity was found to be significantly decreased in lathyrus exposed group (20%). The intestinal biomarker contents including hexose (25%-34%) and phospholipids (20%-40%) were significantly reduced in lathyrus and scorbutic plus lathyrus exposed animals, while sialic acid showed a significant decrease (28%) in scorbutic plus lathyrus treated group. However, cholesterol levels were signifcantly enhanced (15%-28%) in lathyrus and scorbutic plus lathyrus treated animals. Conclusion The results indicate that oral feeding of lathyrus pulse to guinea pigs can alter BBM parameters as well as XME, which may result in the intestinal toxicity.Further, ascorbic acid deficiency could be one of the pre-disposing factors of lathyrus toxicity.
2002, 15(4): 323-329.
Objective To determine the effects of zinc-deficiency and zinc-excess on bone metabolism. Methods We developed the culture model of fetal mouse limbs (16th day) cultivated in self-made rotator with continuing flow of mixed gas for six days in vitro. The cultured limbs were examined by the techniques of 45Ca tracer and X-roentgenography. Results The right limbs cultivated had longer bone length, higher bone density than the left limbs uncultivated from the same embryo; and histologically, the right limbs had active bone cell differentiation, proliferation, increased bone trabecula, clearly calcified cartilage matrix, and osteogenic tissue. Compared with the control group,the zinc-deficient group and zinc-excess (Zn2+120 μmol/L) group contained less osteocalcin (BGP) and 45Ca content, and lower AKP activity; whereas zinc-normal (Zn2+45 μmol/L and Zn2+70 μmol/L)groups contained more BGP and 45Ca contents, and higher AKP (alkaline phosphatase) activity.Conclusion Both zinc-deficiency and zinc-excess can alter bone growth and normal metabolism.The results indicate that the culture model of fetal mouse limbs (16th day) in vitro can be used as a research model of bone growth and development.
Lead Can Inhibit NMDA-, K+-, QA/KA-Induced Increases in Intracellular Free Ca2+ in Cultured Rat Hippocampal Neurons
2002, 15(4): 330-340.
Objective To examine the effects of Pb2+ on N-methyl-D-aspartate (NMDA)-, K+- and quisqualate(QA)/kainite(KA)-induced increases in intracellular free calcium concentration ([Ca2+]i) in cultured fetal rat hippocampal neurons in order to explain the cognitive and learning deficits produced by this heavy metal. Methods Laser scanning confocal microscopy was used. Results The results clearly demonstrated that adding Pb2+ before or after NMDA/glycine stimulation selectively inhibited the stimulated increases in [Ca2+]i in a concentration-dependent manner. In contrast, Pb2+ treatment did not markedly affect increases in [Ca2+]i induced by an admixture of QA and KA. The minimal inhibitory effect of Pb2+ occurred at 1 μ mol/L, and more than seventy percent abolition of the NMDA-stimulated increase in [Ca2+]iwas observed at 100 μmol/L Pb2+. Evaluation of pb2+-induced increase in [Ca2+]i response to elevating extracellular concentrations of NMDA, glycine or calcium revealed that Pb2+ was a noncompetitive antagonist of both NMDA and glycine, and a competitive antagonist of Ca2+ at NMDA receptor channels. In addition, Pb2+ inhibited depolarization-evoked increases in [Ca2+]i mediated by K+ stimulation (30 μmol/L), indicating that Pb2+ also depressed the voltage-dependent calcium channels. Also, the results showed that Pb2+ appeared to be able to elevate the resting levels of [Ca2+]i in cultured neurons, implying a reason for pb2+-enhanced spontaneous release of several neurotransmitters reported in several previous studies. Conclusion Lead can inhibit NMDA-, K+-, QA/KA-inducod increases in intracellular [Ca2+]i in cultured hippocampal neurons.
2002, 15(4): 341-346.
Objective To investigate an effective method to facilitate the physical and mental recovery of drug abusers in detoxification restoration period. Methods Integrated interventions were adopted to observe the changes in the physical and mental conditions of female drug abusers who had withdrawn drugs. Results Comparing behavioral changes between the two groups before and after intervention, we found that changes of score in the intervention group were all higher than those in the control group in terms of their physical symptoms or state of anxiety. Conclusion It is necessary to help drug abusers understand the harm of drug-abuse, build up self-confidence and improve EQ through interventions, It will be beneficial for the drug addicts to refrain from drug-taking and regain a normal life. Our study has proved that positive results can only be obtained from integrated intervention projects.
2002, 15(4): 347-354.
Objective This study examined the status of health-related behaviors among rural residents and the factors influencing the practice of such behaviors. Methods One thousand and ninety subjects aged 15 years or over in a rural community, Anhui Province, China were surveyed. A questionnaire was used to collect information on the health knowledge, attitude and behavior of the subjects. Information on health behavior included smoking, drinking, dietary habits, regular exercises, sleeping pattern and oral health behavior. Results The prevalence of smoking and drinking in the male subjects was 46.5% and 46.9%, respectively. There was a positive significant association between smoking and drinking. Only 8.3% of all subjects ate three regular meals a day regularly. Among subjects who ate two meals a day, 89.7% did not have breakfast. Only 1.7% of subjects took part in regular exercise. About 85% of subjects slept 6 to 8 h per day. Only 38.4 % of the respondents had the habit of hand washing before eating and after using the lavatory. 79.3% of the subjects brushed their teeth every day, and among them, only 10.6 percent brushed their teeth twice a day.Further analyses showed that 64.8% of subjects had 3-5 items of positive health behaviors out of 8 items and only 16.9% had six or more items. Logistical regression analyses suggested that better health behavior was affected by sex, age, years of education, income and health knowledge.Conclusion The status of health behaviors among rural residents was generally poor. It is thus urgent to reinforce health education in rural communities in China.