Biomedical and environmental sciences : BES最新文献

Objective: To study the feasibility of enforcing immunization certificate check before children enroll in primary schools or kindergartens in Guizhou Province.

Methods: Quantitative and qualitative studies were conducted. The multi-stage and cluster sampling approach was adopted for the quantitative part of the study. A questionnaire was designed and 996 children and their keepers were interviewed. Principals, doctors or teachers of the primary schools, directors and child care nurses of kindergarten, and staff of immunization agencies were invited to take part in 12 focus group discussions; meanwhile, face-to-face individual in-depth interviews with 16 officials of the Health, Education and Governmental Departments at various levels were conducted.

Results: The total number of subjects was 996. 16.7% of the children in the study completed all the procedures of the National Immunization Programme. 34.3% of them had immunization certificates while the remainder 44.7% registered in immunization agencies. Factors, including the migrant children, doubt about vaccine efficiency, mother's occupation and educational background, knowledge of the National Immunization Programme on targeted vaccines, played an important role in obtaining or not immunization certificates. 95% of the keepers interviewed thought the immunization certificates were useful; 94.8% of them considered the check was critical while only 3.6% of them thought it unnecessary. The first reason from those who found it unnecessary was that they feared that repeated immunization might affect their children's health. The second reason was the cost of immunization, which some of them could not afford to pay. However, the Health Department expressed a favorable attitude to the checking scheme. Though the Education Department agreed that the scheme was essential, they worried that it would affect the enrollment rate.

Conclusion: In spite of the difficulty in administering immunization certificate check, the effort would be rewarding for raising the immunization coverage rate among the children in Guizhou Province.

Objective: To reduce tobacco consumption and exposure to passive smoking in China.

Methods: Discussion consisting of 80 focus groups and 35 interviews were held in three rural intervention counties of Jiangxi, Henan, and Sichuan Provinces. Participants came from hospitals, schools, rural areas, and urban areas.

Results: Tobacco use and exposure to passive smoking were widely prevalent in the investigated schools, hospitals, county towns, and rural areas. Knowledge of the risks for passive smoking on health is lacking, especially in rural areas. Barriers to the control of tobacco use in public places include reluctance of administrators to implement tobacco control policies, lack of consistent policies, difficulties with regulations and enforcement, and reluctance of non-smokers to exercise their right to clean air.

Conclusion: To curb the current tobacco epidemic in China, tobacco control efforts must focus on reducing exposure to passive smoking. A strategy should be formulated to reduce the factors that contribute to tobacco use and exposure to passive smoking.

Objective: Traumatic brain injury (TBI) is one of the leading causes of morbidity and mortality in young people. Inflammatory cytokines play an important part in the pathophysiology of TBI. Recent studies demonstrate that progesterone significantly reduces cerebral edema and enhances functional recovery from TBI and stroke in several animal models. This study was designed to investigate the inhibitory effect of progesterone on inflammatory response after traumatic brain injury.

Methods: Progesterone was injected intraperitoneally using rats as a model of traumatic brain injury, and Western blot technique was applied to detect the expression of three inflammation-related factors: nuclear factor kappa B p65 (NFkappaB p65), glial fibrillary acidic protein (GFAP), and tumor necrosis factor-alpha (TNF-alpha). The water content of injured brain was also examined. A neurological severity score was recorded to evaluate the effect of progesterone on neurodeficit recovery.

Results: NFkappaB p65, GFAP, and TNF-alpha were increased in all injured animals. In rats treated with progesterone, the expression level of NFkappaB p65 and TNF-alpha were reduced significantly in comparison with vehicle-treated rats. However, progesterone did not alter the expression of GFAP in the injured rats. Progesterone also reduced the water content of injured brain and the lesion volume. In addition, progesterone-treated injured rats showed significant improvements in the Neurological Severity Score test, compared with vehicle-treated ones.

Conclusions: Progesterone inhibits the inflammatory response after experimental traumatic brain injury and mitigates the severity of brain damage.

Objective: To identify the direct causes of drug relapse and abstainers' demand, and to develop programs for the prevention of drug relapse.

Methods: Abstainers in a Compulsive Detoxification Center in Wuhan City, capital of Hubei Province were randomly selected. An investigation on the direct causes of drug relapse and abstainers' demands was conducted with multiple-choice questionnaires and face to face interviews. Data were analyzed with SPSS 12.0.

Results: The direct causes leading to drug relapse included: temptation to use drug again by themselves or by their drug mates, seeking pleasure and ecstasy from drug use, relatively well off living, mental stress, irritation, demoralization, family conflicts, unemployment, feeling distrusted by the family, lack of care and love from the family, and discrimination by others. abstainers' demands after detoxification and returning to the society included: care and support from the family, employment assistance, changing living environment, understanding by others, support from the society, and keeping far away from drugs.

Conclusions: Environmental factors are the direct causes of drug relapse, and negative irritation is its predisposing causes. Leaving former residence, more care and help given by both the family and the society and raising their overall quality of life are the demands of abstainers.

Objective: To evaluate whether the clustering of risk factors, both environmental and genetic, increases the risk of essential hypertension (EH) and the accumulation of risk factors influences the blood pressure level in normotensives.

Methods: On the basis of a prevalence survey, 501 subjects of Mongolian ethnicity (243 hypertensives and 258 normotensives) who were not related to each other were selected to conduct a case-control study. All subjects were interviewed with questionnaires and their blood specimens were collected. Renin gene insertion/deletion (I/D) polymorphism, a new genetic marker, was genotyped with PCR and polyacrylamide gel electrophoresis.

Results: Overweight, alcohol consumption, and renin gene I/D polymorphism were significant risk factors of EH (P<0.05). The odds ratios (OR) for the number of risk factors were 2.39 (95%CI: 0.98-6.74) for one risk factor, 5.03 (95%CI: 2.06-14.18) for two, and 6.09 (95%CI: 1.85-22.38) for three respectively after adjusting for age and sex. In normotensives, age- and sex-adjusted mean blood pressures increased with more accumulation of risk factors. However, there were no significant differences among the different blood pressure levels according to the number of risk factors (P>0.05).

Conclusion: Overweight, alcohol consumption, and renin gene I/D polymorphism are risk factors of EH in the Mongolian ethnic population of China. The accumulation of the risk factors causes a sharp increase of the risk of EH.

Objective: To explore the association between polymorphism in the ACE I/D gene and blood pressure-lowering response to hydrochlorothiazide (HCTZ) in 829 patients.

Methods: HCTZ 12.5 mg was taken once a day for six weeks. The blood pressure reduction and ratio reaching target blood pressure were compared in different ACE genotype groups.

Results: The reduction in SBP of patients carrying DD was greater than that in other groups carrying II or ID (12.2 mmHg versus 5.4 mmHg, 12.2 mmHg versus 4.4 mmHg, respectively, P<0.05). The reduction in MAP of patients carrying DD was also greater than that in other groups carrying II or ID (6.9 mmHg versus 3.9 mmHg, 6.9 mmHg versus 3.6 mmHg, respectively, P<0.05). The ratio reaching target blood pressure in DD groups was significantly higher than that in II or ID groups (P<0.05). The pre-treatment SBP, DD genotype, aldosterone levels entered the multi-linear regression model significantly and might affect the reduction of SBP. The pre-treatment DBP, aldosterone levels, DD genotype entered the multi-linear regression model significantly and might affect the reduction of DBP. The pre-treatment MAP, DD genotype, aldosterone levels entered the multi-linear regression model significantly and might affect the reduction of MAP.

Conclusion: ACE genotyping is associated with blood pressure-lowering response to HCTZ. Specific genotypes might be associated with the response to specific antihypertensive treatment.

Objectives: To investigate the effects of cadmium exposure on insulin expression in rats.

Methods: Eighteen adult SD rats were administered cadmium subcutaneously (0.5, 1.0, and 2.0 mg/kg x bw). The effects on endocrine of pancreas were assessed. The levels of cadmium and zinc in pancreas, blood and urine glucose, serum insulin and urine NAG (N-acyetyl-beta-glucosaminidase) were determined. The gene expressions of metallothionein (MT) and insulin were also measured, and the oral glucose tolerance tests (OGTT) were carried out.

Results: The contents of cadmium in pancreas in cadmium-treated rats were higher than that in the control group, which was associated with slight increase of zinc in pancreas. Cadmium-exposed rats (1.0 and 2.0 mg/kg x bw) demonstrated a marked glucose intolerance. But the levels of serum insulin did not change significantly after cadmium administration, and the UNAG had no change in Cd-treated group. The gene expression of insulin decreased in 1.0 and 2.0 mg/kg x bw cadmium-exposed groups, compared with the control group. The expression of MT-I was higher in the groups exposed to 1.0 and 2.0 mg/kg x bw cadmium while the expression of MT-II was higher in the group exposed to 2.0 mg/kg x bw cadmium.

Conclusions: Cadmium may be accumulated in the pancreas, resulting in the change of the expression of insulin, MT-I and MT-II genes. Cadmium can influence the biosynthesis of insulin, but does not induce the release of insulin. The dysfunction of pancreas occurs earlier than that of kidney after administration of cadmium.

Objective: To assess the phytochemical properties of Chromoleana odorata in the control of blackflies to help check the problem of environmental pollution from the use of chemical insecticides.

Methods: Dried pulverized leaves of Chromolaena odorata (100 g) were soaked in distilled water for 24 hours and the extract was filtered, marc pressed and evaporated over water bath. Stock solution of the dried mass (1 g) was concentrated by dissolving in 100 mL of water. Serial dilutions (100 mg/mL, 10 mg/mL, 1 mg/mL, 0.1 mg/mL, 0.01 mg/L, and 0.001 mg/mL) of both the extract and Chlopyrifos (organo phosphorus) were prepared and toxicity was tested on the larvae of Simulium species.

Results: The chemical compound recorded 100% larval mortality at all concentrations while the plant extract recorded 100% larval mortality in three (100, 10, and 1 mg/mL) of its diluent concentration. The percentage of larval mortality by chemical compound and plant extract was statistically insignificant (t=0.2456, P>0.05), but the mortality rate was significant within 30 min interval of exposure time (t=3.756, P<0.05). The LC50 of the plant extract was determined at about 0.001 mg/mL concentration. This showed that the plant extract had an appreciable larvicidal property close to that of the chemical compound.

Conclusion: This result indicates the usefulness of plant materials in the control of obnoxious insect vectors of mn. It also opens additional approach to the management of environment from toxic chemicals that are non-biodegradable and cause environmental imbalance in the ecosystem.

Objective: To elucidate the genetic characterization and molecular epidemiological features of Echovirus 19 (E19) isolates collected from an outbreak associated with hand, foot and mouth disease (HFMD) in Tai'an city of Shandong Province of China from July to September, 2003.

Methods: Thirty seven Echovirus 19 isolates were isolated from stool specimens and throat swabs collected during the outbreak, then major capsid (VP1) genomic sequence was determined, and phylogenetic tree was done based on the VP1 sequences among these 37 and other E19 viruses deposited in the Genbank. Also a representative strain named CHN-SD03-TN12 was selected for sequencing of 5'-untranslated regions (5'-UTR).

Results: The identity rate was about 98.9%-100% among all these 37 E19 viruses. The genetic relationships between these 37 E19 isolates and other strains reported were also depicted. The identity rate was about 78.4%-78.9% compared with E19 reference strain Burke. The substitutions in the sequence of 5'-UTR resulted in changes in the conjectural properties of 5'-UTR of E19 viruses.

Conclusion: The genetic features of E19 viruses isolated during the outbreak in Shandong Province in 2003 may be associated with a genetic and antigenic drift that changes the virulence of the Shandong isolates, but the molecular changes in Shandong E19 viruses contributing to their phenotype remain to be further illuminated. However, the sequences described in this paper substantiate the changes taken place in capsid VP1 and 5'UTR regions. These substitutions may contribute to their tropism and virulence, and play a significant role in pathogenesis and clinical manifestations of the disease.

Objective: To explore whether condom use is influenced by power relation in commercial sex behaviors.

Methods: Variables were designed to measure the power relation in commercial sex behaviors based on the theory of gender and power relation and data were collected from male sexually transmitted diseases (STD) patients and female commercial sex workers (FSWs) working at recreation centers or being detained in a women education center to identify the relationship between condom use and power relation in male and female respondents using bivariate and multiple regression analysis.

Results: A significant relationship was identified between power relation and female condom use, the higher the score of power relations, the higher frequency the condom use, but no similar result was found in males. Females got a higher score of power relation than males.

Conclusions: Power relation is one of the factors that influence condom use, which should be considered when relevant theories are used to study the rate of condom use. It is worthwhile exploring the relationship between safe sex and power relation in spouses and regular sex partners when interventions are adopted to prevent HIV/AIDS spreading from high risk groups to the general population.