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1.
The possible association between the risk of rectal cancer and the levels of calcium and magnesium in drinking water from municipal supplies was investigated in a matched case-control study in Taiwan. All eligible rectal-cancer deaths (986 cases) of Taiwan residents from 1990 through 1994 were compared with a sample of deaths from other causes (986 controls), and the levels of calcium and magnesium in the drinking water of these residents were determined. Data on calcium and magnesium levels in drinking water throughout Taiwan were obtained from the Taiwan Water Supply Corporation (TWSC). The control group consisted of people who died from other causes, and the controls were pair-matched to the cases by gender, year of birth and year of death. Compared with those with calcium levels below 22.0 mg/liter, the adjusted odd ratios (95% confidence interval) were 0.72 (0.53-0.98) for the group with water calcium levels between 22.0 and 40.8 mg/liter and 0.63 (0.45-0.87) for the group with calcium levels of 40.9 mg/liter or more. The adjusted odd ratios were not statistically significant for the relationship between magnesium levels in drinking water and rectal cancer. The results of the present study show that there may be a significant protective effect of calcium intake from drinking water on the risk of rectal cancer.  相似文献   

2.
A population-based case-control study was carried out to follow up observations of increased lung cancer risk in the steel pouring areas of two Ontario steel mills. Study subjects were all men, aged 45-75 years, who died of lung cancer in the cities of Hamilton or Sault Ste-Marie, Ontario from 1979-1988. Nine hundred sixty-seven lung cancer victims were matched with 2,827 control subjects who died of other causes. Work histories were provided by the employers of steelworkers. In comparison with other residents of their cities, the relative risk of death from lung cancer was 0.85 (95% confidence interval [CI]: 0.58-1.23) for steelworkers in Sault-Ste Marie and was 1.10 (95% CI: 0.89-1.37) for steelworkers in Hamilton. In internal comparisons within the steel companies, increased lung cancer risk was observed among foundry, coke oven, and pouring pit workers. Retrospective hygiene assessment suggested that the increased risk of lung cancer among steel pourers might be related to the use of tar-based mold coating agents or to exposure to mineral fibers.  相似文献   

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Relatively little is know about the sexual behaviors of high-risk adolescents, such as delinquent and homeless youths. Having secured data from medical examinations, this study provides sexual risk profiles for a sample of delinquent (N = 245) and homeless (N = 160) youths in San Francisco, California. The study found several indicators of high-risk behaviors, such as high levels of STDs, trading sex for money or drugs, and unprotected sexual relations with multiple partners. The study suggests that communities provide better sex education and medical services to high-risk adolescents through multi-service health clinics, public health clinics, and street outreach.  相似文献   

5.
Postponing Sexual Involvement (PSI) is a widely implemented middle school curriculum designed to delay the onset of sexual intercourse. In an evaluation of its effectiveness among seventh and eighth graders in California, 10,600 youths from schools and community-based organizations statewide were recruited and participated in randomly assigned intervention or control groups; the curriculum was implemented by either adult or youth leaders. Survey data were collected before the program was implemented, and at three months and 17 months afterward. At three months, small but statistically significant changes were found in fewer than half of the measured attitudes, behaviors and intentions related to sexual activity; at 17 months, none of these significant positive effects of the PSI program had been sustained. At neither follow-up were there significant positive changes in sexual behavior; Youths in treatment and control groups were equally likely to have become sexually active, and youths in treatment groups were not less likely than youths in control groups to report a pregnancy or a sexually transmitted infection. The evaluation suggests that PSI may be too modest in length and scope to have an impact on youths' sexual behavior.  相似文献   

6.
A case of multiple neonatal haemangiomatosis is described. A short course of steroid therapy produced rapid and marked improvement of cutaneous lesions, without any effect on testicular involvement. The authors emphasize the value of an early treatment with steroids.  相似文献   

7.
Investigated the empirical derivation of clinically and theoretically meaningful subtypes among 172 males (mean age 36.74 yrs) arrested for driving while intoxicated (DWI). Five subtypes were defined through cluster analysis of driving-attitudinal, personality, and hostility measures. Two subtypes were found to have particularly high levels of risk-enhancing traits. The first was characterized by the highest levels of depression and resentment as well as the lowest levels of assertiveness, emotional adjustment, and perceived control. The second was characterized by the highest levels of driving-related aggression, competitive speed, sensation seeking, assaultiveness, irritability, and indirect and verbal hostility. Subsequent analyses indicated that these 2 subtypes were also of lower social position, heavier drinkers, and had higher risks of accident involvement in comparison to the remaining clusters. Results are discussed with respect to the need for differential assessment and treatment approaches when dealing with a DWI population. (48 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

8.
BACKGROUND: Although several clinical and epidemiologic studies suggest that timely diagnostic procedures of the large bowel may reduce mortality from colorectal cancer, the evidence for this relationship is primarily circumstantial. METHODS: A case-control study was conducted among hospitalized US military veterans to investigate whether diagnostic procedures of the large bowel were performed in the period preceding the diagnosis of colorectal cancer less frequently in patients dying of colorectal cancer than in control patients. Data files of a total of 4411 veterans dying of colorectal cancer between 1988 and 1992 were extracted from the records of the US Department of Veterans Affairs, Washington, DC. Data of four living control patients and four dead control patients without colorectal cancer were matched by age, sex, and race to each case patient. The case and the two control populations were compared by conditional logistic regression, calculating odds ratios, and their 95% confidence interval. RESULTS: Diagnostic procedures of the large bowel reduced mortality from colorectal cancer, the odds ratio being 0.41 (range, 0.33 to 0.50) for the comparison with living control patients. The protective effects of proctosigmoidoscopy, colonoscopy, and polypectomy lasted for 5 years. The procedures were protective against death from cancer of the colon, as well as cancer of the rectum. The most protective influence was associated with removal of tissue through biopsy, fulguration, and polypectomy. Similar influences were found comparing case patients with dead control patients. CONCLUSION: Removal of tissue represents the most effective means to reduce mortality from cancers of the large bowel. It retains its efficacy over a time period of 5 years.  相似文献   

9.
The availability of organic carbon is considered the key factor to regulate microbial regrowth in drinking water network. However, boreal regions (northern Europe, Russia, and North America) contain a large amount of organic carbon in forests and peatlands. Therefore, natural waters (lakes, rivers, and groundwater) in the northern hemisphere generally have a high content of organic carbon. We found that microbial growth in drinking water in Finland is highly regulated not only by organic carbon but also by the availability of phosphorus. Microbial growth increased up to a phosphate concentration of 10 micrograms of PO4-P liter-1. Inorganic elements other than phosphorus did not affect microbial growth in drinking water. This observation offers novel possibilities to restrict microbial growth in water distribution systems by developing technologies to remove phosphorus efficiently from drinking water.  相似文献   

10.
A nonconcurrent prospective study was conducted to investigate the postulated relationship between organic chemical by-products of water chlorination and risk of human cancer. Vital records and nonofficial census data available for each of nearly 31,000 study subjects were used to compute selected sex- and site-specific cancer incidence rates in a well-defined county population. Age, socioeconomic status, smoking history, source of drinking water at home, and other individual characteristics of the study population were examined in relation to the cancer rates. The drinking water source variable consisted of three historical cohorts, each distinguished by a different degree of exposure to chloroform and other chlorination byproducts. Incidence rates for cancer of the bladder among men and for cancer of the liver among women were nearly twofold higher in the drinking water cohort that had been supplied chlorinated surface water at home when compared to the cohort with a history of consumption of unchlorinated ground water. The differences, however, were not statistically significant. A complementary mortality study also suggested an association of chlorinated water with cancer of the liver and urinary tract. The findings in Washington County indicate the need for further studies of individuals with different histories of exposure to chlorinated and unchlorinated drinking water.  相似文献   

11.
BACKGROUND: Many Legionella infections are acquired through inhalation or aspiration of drinking water. Although about 25% of municipalities in the USA use monochloramine for disinfection of drinking water, the effect of monochloramine on the occurrence of Legionnaires' disease has never been studied. METHODS: We used a case-control study to compare disinfection methods for drinking water supplied to 32 hospitals that had had outbreaks of Legionnaires' disease with the disinfection method for water supplied to 48 control-hospitals, with control for selected hospital characteristics and water treatment factors. FINDINGS: Hospitals supplied with drinking water containing free chlorine as a residual disinfectant were more likely to have a reported outbreak of Legionnaires' disease than those that used water with monochloramine as a residual disinfectant (odds ratio 10.2 [95% CI 1.4-460]). This result suggests that 90% of outbreaks associated with drinking water might not have occurred if monochloramine had been used instead of free chlorine for residual disinfection (attributable proportion 0.90 [0.29-1.00]). INTERPRETATION: The protective effect of monochloramine against legionella should be confirmed by other studies. Chloramination of drinking water may be a cost-effective method for control of Legionnaires' disease at the municipal level or in individual hospitals, and widespread implementation could prevent thousands of cases.  相似文献   

12.
A method of automated detection of onset and termination of rhythmic muscle activity in electromyograms (EMGs) is presented. A threshold level in the EMG is computed, such that amplitudes in the EMG signal exceeding this level indicate muscle activity. The threshold level is determined using a statistical criterion based on the amplitude distribution of the entire EMG signal. The working of the method is illustrated with EMG signals recorded from chewing muscles. EMG signals with a good as well as a worse signal-to-noise ratio are presented. The method can be used for any EMG signal containing cyclic bursts of activity and thus may be applied in studies on rhythmic movements, such as chewing, walking and breathing. An automated method of EMG burst detection has the advantage that large amounts of EMG data can be easily and objectively processed.  相似文献   

13.
Atherosclerotic lesion of the aorta and lipid peroxidation (LPO) in blood and in lipoproteins produced in hepatocytes were studied in rabbits with experimental atherosclerosis maintained on a diet enriched in polyunsaturated fatty acids containing in corn oil (2 ml/kg daily during 30 days) and antioxidants alpha-tocopherol and carnosine (2.5 mg/kg and 50 mg/kg, respectively, daily during 30 days). This diet exhibited a hypocholesterolemic effect accompanied by approximately a 10-fold decrease of the impaired aortic area, as well as lowered content of 2-thiobarbituric acid-positive LPO products occurring in blood and, especially, in apoB lipoproteins. The antioxidant-containing diet decreased distinctly the content of LPO products both in the liver tissue homogenate and lipoprotein fraction (d < 1.065 g/cm3) produced by hepatocytes during 30-min perfusion of liver tissue. The findings suggest that the diet enriched in polyunsaturated fatty acids and antioxidants contributed to a decrease of LPO products content in the blood serum and apoB lipoproteins as well as to the inhibition of lipoprotein oxidation during their synthesis in liver cells; the diet may be recommended for the prophylaxis and treatment of atherosclerosis.  相似文献   

14.
Adenovirus infection of the gastrointestinal tract in human immunodeficiency virus (HIV)-infected patients is rarely reported, probably because of a lack of familiarity of most pathologists with diagnostic criteria during routine light microscopy and possible misidentification as cytomegalovirus infection. We studied colonoscopic biopsy specimens from 135 HIV-infected patients with clinically suspected cytomegalovirus colitis during a 4.5-year period to morphologically identify the presence of adenovirus infection. Immunohistochemical staining for adenovirus was performed for confirmation on all suspected cases. Adenovirus infected cells showed characteristic amphophilic or eosinophilic nuclear inclusions, predominantly affecting the surface epithelium and characteristically involving goblet cells. Sixteen cases showed morphologic features of adenovirus infection, all confirmed by immunohistochemistry. Twelve cases also showed cytomegalovirus infection, whereas 4 showed adenovirus alone. In 10 cases, adenovirus colitis was not recognized during initial routine histopathologic diagnostic evaluation. Adenovirus inclusions also were discovered in the stomach, the duodenum, and the liver in single cases. Conclusions are as follows: (1) Adenovirus colitis has been underdiagnosed at our institution and, we suspect, in general. (2) The morphologic features and nuclear inclusions of adenovirus colitis are characteristic and can be identified reliably by routine light microscopy. (3) Adenovirus infection also may be diagnosed morphologically in extracolonic sites, such as the stomach, the small intestine, and the liver. (4) Coinfection of adenovirus with cytomegalovirus and other agents is seen frequently, but, less frequently, adenovirus may be identified as a sole pathogen.  相似文献   

15.
On April 28th, 1997, the Health Council of the Netherlands Committee on Lead in Drinking Water presented their advisory report to the Minister of Housing, Spatial Planning and the Environment and the Minister of Health, Welfare and Sport. In the report the Committee concluded that, through intake of drinking water, small infants are at risk of being exposed to concentrations of lead that can be detrimental to health, viz., infants in the first six months of life who are bottle-fed on formula milk made up using water that has passed through lead piping. In order to protect this specific group, the Committee advised to lower the currently effective standard for lead in drinking water from 50 to 10 micrograms/l and to replace all lead piping as soon as possible.  相似文献   

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In the context of evaluating their pathogenic relevance, culture on solid media is the only approach presently suitable for culture of psychotrophic aeromonads from drinking water. In this respect, a check must be effected to ensure that the culture medium cannot engender selective culture losses for individual species. For this reason, media to which e.g. ampicillin has been added are unsuitable.  相似文献   

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The associations found in the general populations of a number of different countries are suggestive and warrant an integrated program of laboratory and epidemiologic research to reject or confirm the magnesium-IHD hypothesis. Singling out this particular risk factor has two justifications. First, as would be the case with any epidemiologic risk factor for IHD whose attributable risk was large enough to be detectable through epidemiology, applying that attributable risk to the vast annual morbidity and mortality from IHD would translate into tens of thousands of lives benefited and millions of dollars in hospital costs avoided per year. Second, this particular risk factor could conceivably be eliminated by an inexpensive supplementation program. For example, a low-sodium, higher-magnesium and -potassium table salt has been recommended and used in Finland for many years, during a period when the prevalence of hypertension in population surveys was said to decrease (117). Interventions which do not require behavioral change have always been the most cost-effective in public health. We therefore urge funding agencies to give priority to studies determining whether there are unforeseen adverse effects of magnesium for some population subgroups and whether the apparent benefit derived from low doses of magnesium in the development of IHD or IHD death is real. Furthermore, researchers should determine which chemical form of magnesium is best absorbed and most effective. We need to better understand the interrelation of various water and food constituents, as well as individual risk factors, in the pathogenesis of IHD. Susceptible individuals who are at higher risk of being depleted of magnesium need to be identified, and potential untoward effects of magnesium should be studied. Future research must provide better answers about low level waterborne magnesium before recommendations to the public can be made.  相似文献   

20.
Examined whether marital discord over childrearing contributes to child behavior problems after taking into account general marital adjustment, and if child age moderates associations between child behavior problems and either general marital adjustment or marital discord over childrearing. Participants were 146 two-parent families seeking services for their child's (4 to 9 years of age) conduct problems. Data on marital functioning and child behavior problems were collected from both parents. Mothers' and fathers' reports of marital discord over childrearing related positively to child externalizing problems after accounting for general marital adjustment. Child age moderated associations between fathers' reports of general marital adjustment and both internalizing and externalizing child problems, with associations being stronger in families with younger children. The discussion highlights the role that developmental factors may play in understanding the link between marital and child behavior problems in clinic-referred families.  相似文献   

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