Risk factors for persistent diarrhoea.

With a systematically sampled population of children aged under 5 attending this centre for diarrhoeal disease research during 1983-5 a retrospective analysis of persistent diarrhoea (defined as greater than 14 days'' duration) was performed to identify the possible risk factors for this syndrome. Of the 4155 children included in the analysis, 410 (10%) gave a history of persistent diarrhoea. A comparison with children with acute diarrhoea matched for age showed that 11 factors were correlated with persistent diarrhoea, and strongly associated factors were stools with blood or mucus, or both, lower respiratory tract infection, malnutrition, vitamin A deficiency, and antibiotic use before presentation. The peak age was 2 years, and there was no sex difference. Deaths occurred more often in the group with persistent diarrhoea. Although Shigella spp, Campylobacter jejuni, and Giardia lamblia were frequently identified, their rates of isolation were not significantly higher among patients with persistent diarrhoea. No seasonal variation was observed in the rates of persistent diarrhoea. Although the introduction of family food to the diet was associated with higher rates, this factor was difficult to separate from the age dependent risks.     

Risk factors for winter outbreak of acute diarrhoea in France: case-control study.

OBJECTIVES: To assess the potential role of consumption of shellfish (particularly raw oysters) and tap water in the winter epidemic of acute diarrhoea in France. DESIGN: Population based, case-control study during the 1995-6 winter epidemic of acute diarrhoea in France. SETTING: A national network comprising 1% of general practitioners in France. SUBJECTS: 568 pairs of cases and controls consulting in general practice and interviewed by 209 doctors from 26 December 1995 to 31 January 1996. Cases and controls were matched for age, doctor, and time of consultation. MAIN OUTCOME MEASURES: Adjusted relative risk of diarrhoea estimated from conditional logistic regression. RESULTS: The risk of acute diarrhoea was not increased in people who had recently eaten raw oysters (odds ratio 1.1; 95% confidence interval 0.9% to 1.4%) or other shellfish such as clams, cockles, and mussels, or in those people who usually consumed tap water rather than bottled water (0.8; 0.6% to 1.1%). The risk was, however, increased in people who had had recent contact wit ha person with diarrhoea either within the household (adjusted odds ratio 5.0) or in the workplace (3.1), and in people who lived with a child < or = 2 years of age (1.6). Recent treatment with either oral penicillin or cephalosporin was also independently associated with acute diarrhoea in winter. CONCLUSIONS: The winter epidemic of acute diarrhoea in France is probably not caused by consumption of either shellfish or tap water. A viral aetiology, however, is suggested by the speed with which the acute diarrhoea is transmitted.     

Case-control study of risk of dehydrating diarrhoea in infants in vulnerable period after full weaning.

OBJECTIVES: To investigate risk factors for dehydrating diarrhoea in infants, with special interest in the weaning period. DESIGN: Case-control study. SETTING: Metropolitan area of Porto Alegre, Brazil. SUBJECTS: Cases were 192 children aged 0-23 months hospitalised with acute diarrhoea and moderate to severe dehydration. Controls were 192 children matched for age and neighbourhood who did not have diarrhoea in the previous week. MAIN OUTCOME MEASURES: Associations between dehydrating diarrhoea and child''s age, type of milk consumed, time since breast feeding stopped, and breast feeding status. RESULTS: In infants aged < 12 months the risk of dehydrating diarrhoea was significantly higher in the first 9 months of life (P < 0.001), and in those aged 12-23 months the risk was again greater in younger children (12-17 months) (P = 0.03). The type of milk consumed before start of diarrhoea episode was strongly associated with dehydration independent of socioeconomic, environmental, maternal reproductive, demographic, and health services factors. Compared with infants exclusively breast fed, bottle fed infants were at higher risk (odds ratio (95% confidence interval) for cow''s milk 6.0 (1.8 to 19.8), for formula milk 6.9 (1.4 to 33.3)). Compared with those still breast feeding, children who stopped in the previous two months were more likely to develop dehydrating diarrhoea (odds ratio 8.4 (2.4 to 29.6)). This risk decreased with time since breast feeding stopped. CONCLUSION: These results confirm the protective effect of breast feeding and suggest there is a vulnerable period soon after breast feeding is stopped, which may be of relevance for developing preventive strategies.     

Increased Risk of Acute Pancreatitis in Patients with Type 2 Diabetes: An Observational Study Using a Japanese Hospital Database

Background

Increased risks of acute pancreatitis in patients with type 2 diabetes mellitus have been reported recently in several countries. We aimed to estimate the risks of acute pancreatitis in Japanese patients with diabetes mellitus.

Methods/Findings

We examined a large-scale hospital administrative database consisting of one million patients in 16 secondary medical care hospitals, from 2003 to 2010. The incidence rates of acute pancreatitis were estimated with cohort design; the odds ratios associated with diabetes mellitus and other comorbid risk factors were estimated with separate case-control analyses.In cohort analysis, the incidence of acute pancreatitis was higher in 14,707 diabetic patients than in 186,032 non-diabetic patients (4.75 vs. 1.65 per 1,000 patient-years) and increased in male patients and as age advanced. The adjusted odds ratio of acute pancreatitis in patients with diabetes mellitus was 1.86 (P<0.001) compared with non-diabetic patients in case-control analysis from 1,372 cases and 5,469 matched controls, which is consistent with the ones reported in previous studies. Alcoholism and gallstones were associated with a large increase in the risk of acute pancreatitis (adjusted odds ratio 13.40 and 14.29, respectively, P<0.001), although dyslipidemia was associated with significant risk reduction (adjusted odds ratio 0.62, P<0.001).

Conclusions

This observational study ascertained the elevated incidence rates and risk of acute pancreatitis in Japanese patients with diabetes. The risk estimates in Japanese patients with diabetes were in agreement with the ones reported in previous studies, and the elevated risk of acute pancreatitis in patients with diabetes would be generalized in different locations/populations.     

Vitamin K and childhood cancer: a population based case-control study in Lower Saxony,Germany.

OBJECTIVE--To confirm or refute a possible association of parenteral vitamin K prophylaxis and childhood cancer. DESIGN--Population based case-control study. Comparison of vitamin K exposure in children with leukaemia or other common tumours with two control groups. SETTING--State of Lower Saxony (north western part of Germany); case recruitment from the German childhood cancer registry. SUBJECTS--272 children with leukaemia, nephroblastoma, neuroblastoma, rhabdomyosarcoma, and tumours of the central nervous system diagnosed between 1 July 1988 and 30 June 1993; children were aged between 30 days and 15 years at diagnosis. 334 population based controls without diagnoses of cancer matched to the leukaemia cases for age and sex. MAIN EXPOSURE MEASURES--Parenteral vitamin K prophylaxis (intramuscular and subcutaneous) versus oral and no vitamin K prophylaxis. RESULTS--An association between parenteral vitamin K exposure and childhood cancer (leukaemias and other tumours combined) could not be confirmed (odds ratio 1.04, 95% confidence interval 0.74 to 1.48). For leukaemias the observed odds ratio was only 0.98 (0.64 to 1.50) (comparison of leukaemia cases with local controls 1.24 (0.68 to 2.25); state controls 0.82 (0.50 to 1.36)). These odds ratios remained almost unchanged when several potential confounders were considered in the logistic regression model. CONCLUSIONS--This population based study adds substantial evidence that there is no association between parenteral vitamin K and childhood cancer.     

Polymicrobial infections in children with diarrhoea in a rural area of Jordan

Polymicrobial infections associated with diarrhoea are common in developing countries. Stool specimens were collected from 220 patient children and 100 controls. Potential pathogenic agents isolated from 143 (65%) children were identified by molecular and standard microbiological methods. Co-infections with two or more agents were detected in 50 (35%) cases. Escherichia coli, Shigella dysenteriae, Giardia and Entamoeba histolytica were found to be predominant. The etiologic agents could not be determined in 77 (35%) cases. The most significant risk factors were the age, the education level of the mother and the use of non-chlorinated water. The high infection rate of diarrhoeal diseases is a strong indication that these pathogens circulate easily through the population.     

Impact of massive dose of vitamin A given to preschool children with acute diarrhoea on subsequent respiratory and diarrhoeal morbidity.

OBJECTIVE--To assess the impact of vitamin A supplementation on morbidity from acute respiratory tract infections and diarrhoea. DESIGN--Double blind randomised placebo controlled field trial. SETTING--An urban slum area in New Delhi, India. SUBJECTS--900 children aged 12-60 months attending a local health facility for acute diarrhoea of less than seven days'' duration randomly allocated to receive vitamin A 200,000 IU or placebo. MAIN OUTCOME MEASURES--Incidence and prevalence of acute lower respiratory tract infections and diarrhoea during the 90 days after termination of the enrolment diarrhoeal episode measured by twice weekly household surveillance. RESULTS--The incidence (relative risk 1.07; 95% confidence interval 0.92 to 1.26) and average number of days spent with acute lower respiratory tract infections were similar in the vitamin A supplementation and placebo groups. Among children aged 23 months or less there was a significant reduction in the incidence of measles (relative risk 0.06; 95% confidence interval 0.01 to 0.48). The incidence of diarrhoea was also similar (relative risk 0.95; 0.86 to 1.05) in the two groups. There was a 36% reduction in the mean daily prevalence of diarrhoea associated with fever in the vitamin A supplemented children older than 23 months. CONCLUSIONS--Results were consistent with a lack of impact on acute lower respiratory tract related mortality after vitamin A supplementation noted in other trials and a possible reduction in the severity of diarrhoea.     

Environment of infants during sleep and risk of the sudden infant death syndrome: results of 1993-5 case-control study for confidential inquiry into stillbirths and deaths in infancy. Confidential Enquiry into Stillbirths and Deaths Regional Coordinators and Researchers.

OBJECTIVE--To investigate the role of sleeping arrangements as risk factors for the sudden infant death syndrome after a national risk reduction campaign. DESIGN--Two year population based case-control study. Parental interviews were conducted for each infant who died and for four controls matched for age and date of interview. SETTING--Three regions in England with a total population of 17 million people. SUBJECTS--195 babies who died and 780 matched controls. RESULTS--Prone and side sleeping positions both carried increased risks of death compared with supine when adjusted for maternal age, parity, gestation, birth weight, exposure to smoke, and other relevant factors in the sleeping environment (multivariate odds ratio = 9.00 (95% confidence interval 2.84 to 28.47) and 1.84 (1.02 to 3.31), respectively). The higher incidence of side rather than prone sleeping led to a higher population attributable risk (side 18.4%, prone 14.2%). More of the infants who died were found with bed covers over their heads (21.58; 6.21 to 74.99). The use of a dummy had an apparent protective effect (0.38; 0.21 to 0.70). Bed sharing for the whole night was a significant risk factor for infants whose mothers smoked (9.25; 2.31 to 34.02). No protective effect of breast feeding could be identified on multivariate analysis. CONCLUSIONS--This study confirms the importance of certain risk factors for the sudden infant death syndrome and identifies others-for example, covers over the head, side sleeping position-which may be amenable to change by educating and informing parents and health care professionals.     

Neonatal vitamin K administration and childhood cancer in the north of England: retrospective case-control study.

OBJECTIVE: To explore the possible association between intramuscular vitamin K given to neonates and the subsequent development of childhood cancer. DESIGN: Retrospective case-control study on the basis of hospital records. SETTING: The former Northern Health region of England. SUBJECTS: 685 children who were born and lived in the region and who developed cancer before their 15th birthday, and 3442 controls also born between 1960 and 1991 and matched only for date and hospital of birth. The notes of a further 701 index cases were untraceable. MAIN EXPOSURE MEASURE: Administration of intramuscular vitamin K versus no exposure to vitamin K. RESULTS: There was no association between the administration of vitamin K and the development of all childhood cancers (unadjusted odds ratio 0.89; 95% confidence interval 0.69 to 1.15) or for all acute lymphoblastic leukaemia (1.20; 0.75 to 1.92), but there was a raised odds ratio for acute lymphoblastic leukaemia developing 1-6 years after birth (1.79; 1.02 to 3.15). No such association was seen in a separate cohort-based study not dependent on case note retrieval in which the rates of acute lymphoblastic leukaemia in children born in hospital units where all babies received vitamin K were compared with those born in units where less than a third received prophylaxis. CONCLUSIONS: It is not possible, on the basis of currently published evidence, to refute the suggestion that neonatal intramuscular vitamin K administration increases the risk of early childhood leukaemia. Any association may have been masked in earlier studies that did not use controls matched for time and locality by other unidentified factors affecting the spatiotemporal variations in incidence of leukaemia.     

Breast feeding and vitamin A deficiency among children attending a diarrhoea treatment centre in Bangladesh: a case-control study.

OBJECTIVE--To determine the effect of breast feeding on the risk of xerophthalmia in children aged 6 months to 3 years attending a diarrhoea treatment centre in Bangladesh. DESIGN--Case-control study based on stratified analysis (Mantel-Haenszel) and multivariate analysis (logistic regression) of data from a treatment centre based surveillance system. SETTING--A large diarrhoea treatment centre in Dhaka, Bangladesh. PATIENTS--2687 children aged 6 months to 3 years representing a 4% systematic sample of all children in this age group treated yearly at the centre over three consecutive years. 66 of the children were cases of xerophthalmia (that is, they had Bitot''s spots or corneal lesions or night blindness or night blindness plus conjunctival xerosis or any combination of these) and the remaining 2621 did not have signs or symptoms of vitamin A deficiency. This second group served as controls. MAIN OUTCOME MEASURE--Xerophthalmia and breast fed at onset of diarrhoea or presentation. RESULTS--The odds ratio relating breast feeding to vitamin A deficiency after adjustment for a large number of confounding variables (0.26 (95% confidence interval 0.14 to 0.49); p less than 0.001) reflected a 74% reduction in the risk of vitamin A deficiency among breast fed children. The estimated reduction of risk did not decline with age, and some 49% of children aged 24-35 months were still being breast fed. The odds ratio relating breast feeding to xerophthalmia in the third year of life (0.35 (95% confidence interval 0.35 to 0.86) reflected a 65% reduced risk of vitamin A deficiency. Other important risk factors or prognostic indicators for xerophthalmia as identified by multivariate analysis were recent measles, prolonged diarrhoea, severe protein energy malnutrition, and poor socioeconomic state. CONCLUSIONS--These results indicate that breast feeding was associated with a substantial reduction of the risk of vitamin A deficiency extending to the third year of life and support the recommendation that mothers in developing countries should be advised to breast feed for as long as possible.     

Inheritance of acute appendicitis: familial aggregation and evidence of polygenic transmission.

We explored familiality as well as the heritability and possible mode(s) of inheritance of acute appendicitis in childhood and early adolescence. Our case-control study showed that a positive family history for reported appendectomy was significantly more frequent in families of 80 consecutive patients eventually proved to have histopathologic acute appendicitis than in families of surgical controls matched for sex, age, and number of siblings. The relative risk was 10.0 (95% confidence limits 4.7-21.4). The pattern of familial aggregation was further supported by the fact that the age-standardized morbidity ratio was four times greater among family members of cases than among controls. We then applied the unified mixed model of segregation analysis, as implemented in the computer program POINTER, to a new set of 100 multigenerational pedigrees of children with histopathologically confirmed acute appendicitis that were broken down into 674 nuclear families. Age-specific morbidity risk and lifetime incidence of acute appendicitis were estimated from relatives of controls matched for age and sex to probands. Complex segregation analysis supported a polygenic or multifactorial model with a total heritability of 56%. There was no evidence to support a major gene, although a rare gene could not be ruled out as the cause of a small proportion of cases. Specific studies to address genetic and environmental factors in this serious disease seem worthwhile; but, for now, a positive family history of appendicitis might join other evidence leading to improved clinical recognition of acute appendicitis.     

Migraine and risk of ischaemic stroke: a case-control study.

OBJECTIVES--To determine whether migraine is a risk factor for ischaemic stroke. DESIGN--A case-control study. SETTING--Two hospitals in Paris. SUBJECTS--212 patients with stroke (137 men and 75 women) and 212 controls matched for sex, age (to within five years), and history of hypertension. MAIN OUTCOME MEASURES--Ischaemic stroke, confirmed by brain computed tomography or magnetic resonance imaging, and history of headache, recorded with structured questionnaire during interview. RESULTS--Prevalence of migraine did not differ between patients with stroke and controls: 18/137 v 17/137 for men (odds ratio 1.1 (95% confidence interval 0.5 to 2.2), p = 0.86); 23/75 v 17/75 for women (odds ratio 1.6 (0.7 to 3.5), p = 0.24); and 41/212 v 34/212 for both sexes (odds ratio 1.3 (0.8 to 2.3), p = 0.33). When subjects were split into two age groups, however, prevalence of migraine was significantly higher among younger women (aged < 45) with stroke compared with their controls (13/20 v 6/20, odds ratio 4.3 (1.2 to 16.3), p = 0.03). Furthermore, the risk of ischaemic stroke was higher among younger women who smoked (7/20 v 1/20, odds ratio 10.2 (1.1 to 93.3)). CONCLUSIONS--Prevalence of migraine was not different between patients with stroke and matched controls except among women aged < 45, when migraine and stroke were significantly associated.     

Association of Respiratory Viruses with Outcomes of Severe Childhood Pneumonia in Botswana

BackgroundThe highest incidence of childhood acute lower respiratory tract infection (ALRI) is in low- and middle-income countries. Few studies examined whether detection of respiratory viruses predicts ALRI outcomes in these settings.MethodsWe conducted prospective cohort and case-control studies of children 1-23 months of age in Botswana. Cases met clinical criteria for pneumonia and were recruited within six hours of presentation to a referral hospital. Controls were children without pneumonia matched to cases by primary care clinic and date of enrollment. Nasopharyngeal specimens were tested for respiratory viruses using polymerase chain reaction. We compared detection rates of specific viruses in matched case-control pairs. We examined the effect of respiratory syncytial virus (RSV) and other respiratory viruses on pneumonia outcomes.ResultsBetween April 2012 and August 2014, we enrolled 310 cases, of which 133 had matched controls. Median ages of cases and controls were 6.1 and 6.4 months, respectively. One or more viruses were detected from 75% of cases and 34% of controls. RSV and human metapneumovirus were more frequent among cases than controls, but only enterovirus/rhinovirus was detected from asymptomatic controls. Compared with non-RSV viruses, RSV was associated with an increased risk of treatment failure at 48 hours [risk ratio (RR): 1.85; 95% confidence interval (CI): 1.20, 2.84], more days of respiratory support [mean difference (MD): 1.26 days; 95% CI: 0.30, 2.22 days], and longer duration of hospitalization [MD: 1.35 days; 95% CI: 0.20, 2.50 days], but lower in-hospital mortality [RR: 0.09; 95% CI: 0.01, 0.80] in children with pneumonia.ConclusionsRespiratory viruses were detected from most children hospitalized with ALRI in Botswana, but only RSV and human metapneumovirus were more frequent than among children without ALRI. Detection of RSV from children with ALRI predicted a protracted illness course but lower mortality compared with non-RSV viruses.     

Smoking and the sudden infant death syndrome: results from 1993-5 case-control study for confidential inquiry into stillbirths and deaths in infancy. Confidential Enquiry into Stillbirths and Deaths Regional Coordinators and Researchers.

OBJECTIVE--To investigate the effects of exposure to tobacco smoke and of parental consumption of alcohol and illegal drugs as risk factors for the sudden infant death syndrome after a national risk reduction campaign which included advice on prenatal and postnatal avoidance of tobacco smoke. DESIGN--Two year population based case-control study. Parental interviews were conducted for each infant who died and four controls matched for age and date of interview. SETTING--Three regions in England with a total population of 17 million people. SUBJECTS--195 babies who died and 780 matched controls. RESULTS--More index than control mothers (62.6% v 25.1%) smoked during pregnancy (multivariate odds ratio = 2.10; 95% confidence interval 1.24 to 3.54). Paternal smoking had an additional independent effect when other factors were controlled for (2.50; 1.48 to 4.22). The risk of death rose with increasing postnatal exposure to tobacco smoke, which had an additive effect among those also exposed to maternal smoking during pregnancy (2.93; 1.56 to 5.48). The population attributable risk was over 61%, which implies that the numbers of deaths from the syndrome could be reduced by almost two third if parents did not smoke. Alcohol use was higher among index than control mothers but was strongly correlated with smoking and on multivariate analysis was not found to have any additional independent effect. Illegal drug use was more common among the index parents, and paternal use of illegal drugs remained significant in the multivariate model (4.68; 1.56 to 14.05). CONCLUSIONS--This study confirms the increased risk of the sudden infant death syndrome associated with maternal smoking during pregnancy and shows evidence that household exposure to tobacco smoke has an independent additive effect. Parental drug misuse has an additional small but significant effect.     

Venous Thromboembolism after Community-Acquired Bacteraemia: A 20-year Danish Cohort Study

Background

Infections may increase the risk for venous thromboembolism (VTE), but little is known about VTE risk associated with community-acquired bacteraemia (CAB). We examined the risk for VTE within one year of CAB in comparison to that in matched controls.

Methods

We conducted a population-based cohort study in North Denmark 1992–2011, using data from high-quality health-care databases. We included 4,213 adult CAB patients who had positive blood cultures drawn on the day of hospital admission, 20,084 matched hospitalised controls admitted for other acute medical illness, and 41,121 matched controls from the general population. We computed 0–90 and 91–365 day absolute risks for hospital-diagnosed VTE and used regression analyses with adjustment for confounding factors to compare the risk for VTE in bacteraemia patients and controls.

Results

Among CAB patients, 1.1% experienced VTE within 90 days of admission and 0.5% during 91–365 days after admission. The adjusted 90-day odds ratio (OR) for VTE was 1.9 (95% CI 1.4–2.7) compared with hospitalised controls, and 23.4 (95% CI 12.9–42.6) compared with population controls. During 91–365 days after CAB admission, the VTE risk remained moderately increased (adjusted hazard ratio vs. hospitalised controls, 1.4; 95% CI 0.8–2.5, and vs. population controls, 1.9; 95% CI 1.0–3.3). Compared to hospitalised controls, the 90-day VTE risk increase was greater for Gram-positive infection (adjusted OR 2.5; 95% CI 1.6–4.1) than for Gram-negative infection (adjusted OR, 1.2; 95% CI 0.7–2.1), partly due to a high risk after Staphylococcus aureus infection (3.6%).

Conclusion

The risk for VTE is substantially increased within 90 days after community-acquired bacteraemia when compared to hospitalised controls and population controls. However, the absolute risk of VTE following CAB is low.     

Deficiency in mitochondrial aldehyde dehydrogenase increases the risk for late-onset Alzheimer's disease in the Japanese population

Mitochondrial aldehyde dehydrogenase 2 (ALDH2) deficiency is caused by a mutant allele in the Mongoloids. To examine whether genetic constitutions affecting aldehyde metabolism influence the risk for late-onset Alzheimer's disease (LOAD), we performed a case-control study in the Japanese population on the deficiency in ALDH2 caused by the dominant-negative mutant allele of the ALDH2 gene (ALDH2*2). In a comparison of 447 patients with sex, age, and region matched nondemented controls, the genotype frequency carrying the ALDH2*2 allele was significantly higher in the patients than in the controls (48.1% vs 37.4%, P = 0.001). Logistic regression analysis indicates that carriage of the ALDH2*2 allele is an independent risk for LOAD of the epsilon4 allele of the apolipoprotein E gene (APOE-epsilon4) (P = 0.002). Moreover, the odds ratio for LOAD in carriers of the ALDH2*2 allele was almost twice that in noncarriers, irrespective of status with regard to the APOE-epsilon4 allele. Among patients homozygous for the APOE-epsilon4 allele, age at onset of LOAD was significantly lower in those with than without the ALDH2*2 allele. In addition, dosage of the ALDH2*2 allele significantly affected age at onset of patients homozygous for the APOE-epsilon4 allele. These results indicate that the ALDH2 deficiency is a risk for LOAD, synergistically acting with the APOE-epsilon4 allele.     

A functional polymorphism in miRNA-196a2 is associated with colorectal cancer risk in a Chinese population

Single-nucleotide polymorphisms in microRNAs (miRNAs) may alter miRNA expression levels or processing and, thus, may contribute to cancer development. We hypothesized that miRNA-196a2 polymorphism is associated with risk of colorectal cancer (CRC). In a case-control study of 573 patients with CRC and 588 cancer-free controls frequency matched by age and sex, we genotyped the functional polymorphism rs11614913 (T>C) and assessed its association with the risk of CRC in a Chinese population. We found that the CT/CC genotypes were associated with a significantly increased risk of CRC (odds ratio [OR]=1.44, 95% confidence interval [CI]=1.10-1.88), compared with the TT genotype. Further, the polymorphism was significantly associated with the risk of patients with advanced stage tumor (Dukes C and D) (OR=1.65, 95% CI=1.11-2.46). Our results suggest that the functional polymorphism rs11614913 in miRNA-196a2 is involved in the etiology of CRC and, thus, may be a marker for genetic susceptibility to CRC.     

Home environment and severe asthma in adolescence: a population based case-control study.

OBJECTIVE--To investigate the effects of the home environment on the risk of severe asthma during adolescence. DESIGN--A questionnaire based case-control study drawn from a cross sectional survey of allergic diseases among secondary school pupils in Sheffield in 1991. SUBJECTS--763 children whose parents had reported that over the previous 12 months they had suffered either 12 or more wheezing attacks or a speech limiting attack of wheeze. A further 763 children were frequency matched for age and school class to act as controls. Analysis was restricted to 486 affected children and 475 others born between 1975 and 1980 who had lived at their present address for more than three years. RESULTS--Independent associations with severe wheeze were seen for non-feather bedding, especially foam pillows (odds ratio 2.78; 95% confidence interval 1.89 to 4.17), and the ownership of furry pets now (1.51; 1.04 to 2.20) and at birth (1.70; 1.20 to 2.40). These estimates were derived from subjects whose parents denied making changes in the bedroom or avoiding having a pet because of allergy. Parental smoking, use of gas for cooking, age of mattress, and mould growth in the child''s bedroom were not significantly associated with wheezing. CONCLUSIONS--Either our study questionnaire failed to detect the avoidance or removal of feather bedding by allergic families or there is some undetermined hazard related to foam pillows. Synthetic bedding and furry pets were both widespread in this population and may represent remediable causes of childhood asthma.     

Polymorphisms of CHRNA5-CHRNA3-CHRNB4 Gene Cluster and NSCLC Risk in Chinese Population

AIM: To explore the potential association between single-nucleotide polymorphisms (SNPs) and haplotypes of the CHRNA5-CHRNA3-CHRNB4 gene cluster and the non-small cell lung cancer (NSCLC) susceptibility in never-smoking Chinese. METHODS: A case-control study was conducted with 200 NSCLC patients and 200 healthy controls, matched on age and sex. Five SNPs distributed in CHRNA5-CHRNA3-CHRNB4 gene cluster were selected for genotyping. The association between genotype and lung cancer risk was evaluated by computing the odds ratio (OR) and 95% confidence interval (CI) from multivariate unconditional logistic regression analyses with adjustment for gender and age. RESULTS: For CHRNA3 rs578776 status, data were available in 199 NSCLC patients and 199 controls. The G/G homozygote in CHRNB4 rs7178270 had a reduced risk of developing NSCLC (OR = 0.553; 95% CI = 0.309–0.989; P = .0437), especially squamous cell carcinoma (SQC) (OR = 0.344; 95% CI = 0.161–0.732; P = .0043), compared with those who carry at least one C allele (C/C and C/G). The polymorphisms of rs578776, rs938682, rs17486278, and rs11637635 were not significantly different between controls and cases or between controls and histologic subgroups, adenocarcinoma and SQC, respectively. CONCLUSIONS: In our study, we found that the SNP of CHRNB4 rs7178270 is significantly associated with reduced risk of NSCLC, especially with reduced risk of SQC in never-smoking Chinese population.