Does influenza vaccination exacerbate asthma in children?

BACKGROUND: The risks of influenza vaccination in asthmatic children are still being discussed. Especially, the risk that influenza vaccination may exacerbate asthma is an issue in this debate. METHODS: We conducted a randomised double-blind placebo-controlled trial in 696 children 6-18 years of age with asthma recruited in general practice during two influenza seasons, 1999-2000 and 2000-2001. Children participated for only one season. During the first week after vaccination, participants recorded local, influenza like and asthma symptoms as well as use of medication, health care use and absenteeism. RESULTS: Except for cough during the day in the first season, favouring placebo, there were no differences indicating that vaccination exacerbates asthma. CONCLUSIONS: Influenza vaccination does not seem to exacerbate asthma.     

Does hyperglycaemia cause symptoms in elderly people?

The aim of the present study was to describe the associations between glucose tolerance and symptoms in an unselected non-institutionalised elderly population aged 73 years or over (n = 259, of whom 93 were men). Diabetes was assessed on the basis of self-reports and 2-h oral glucose tolerance tests (1985 WHO criteria). Symptoms were measured with a modified diabetes symptom checklist (DSC-Type 2). The previously diagnosed diabetic patients reported to have more symptoms in all the six dimensions of the symptom checklist than the other study groups. According to the responses to twenty out of 34 items, more of the previously diagnosed diabetic women had symptoms than the other female study groups; the corresponding figure for the previously diagnosed diabetic men being 16/34. The following hyperglycaemic symptoms: "dry mouth", "increasing fatigue in the course of the day", "numbness in the hands", were either weakly or significantly associated with undiagnosed diabetes. Men with IGT reported to have "dry mouth" and "tingling or pricking in the legs or feet" more often than men with NGT. Symptoms of "moodiness" increased along with the deterioration of glucose tolerance, and it seems that depression is associated with type 2 diabetes in elderly people, too. Although the study covered a wide range of symptoms, it did not clearly reveal such symptoms that could be used as potential indicators of undiagnosed diabetes or especially IGT among elderly patients.     

Does the MMR triple vaccine cause autism?

In recent years, there has been widespread public concern about the hypothesis that MMR triple vaccine may increase the risk of autism in children. In this review, we examine the background to, and implications of, this controversy. We then assess and explain, using a transparent and replicable method, all the scientific evidence for and against the hypothesis. We conclude that there are no grounds to suggest that MMR vaccine increases the risk of autism.     

Does regular exercise protect against air pollution-associated mortality?

OBJECTIVES: To examine whether habitual exercise would modify the effects of air pollution on mortality. METHODS: This study included 24,053 Hong Kong Chinese who died at the age of 30 years or older in 1998. Individual information on frequency of exercise was obtained by interviewing their relatives at all four death registries. The deceased subjects were categorized as never-exercise ( or =once/month). Excess risks (ER) of mortality per 10 microg/m(3) increase of air pollutant were estimated separately by a Poisson regression model in the exercise and never-exercise groups. An interaction model was used to estimate the difference in ER between the two groups. RESULTS: In people aged 65 years or older and categorized as never-exercise group, there were significant ER of mortality for all natural causes attributed to nitrogen dioxide (p<0.05), ozone (p<0.05) and particulate matter with an aerodynamic diameter of 10 mum or smaller (p<0.01). When compared to the exercise group, the ER were significantly higher by 4.31% (95% confidence interval: 2.57%, 6.03%), 1.75% (0.25%, 3.23%), and 3.06% (1.74%, 4.37%), respectively. The estimates were insensitive to adjustment for socioeconomic, smoking and health status, and were non-linear by different exercise levels. CONCLUSIONS: The results of this study provide evidence that habitual exercise may prevent premature death attributable to air pollution.     

Does maternal smoking during pregnancy cause childhood overweight?

The objective of this study was to examine a possible association between maternal smoking in pregnancy and childhood overweight. From a population-based cohort of 5722 women from Trondheim, Bergen (Norway) and Uppsala (Sweden) enrolled in early pregnancy during 1986-92, a random sample of 482 women was selected for participation. They were followed up throughout pregnancy, and their children from birth until 5 years of age. Data on maternal smoking and diet, socio-economic determinants and breast feeding were recorded prospectively. During pregnancy and childhood, anthropometric measures were also recorded. Maternal smoking status was based on reported number of cigarettes smoked in week 17 of pregnancy. Child overweight was defined by body mass index (BMI) and sum of skinfold thickness (SFT) >or= 85th percentile at 5 years of age. Children of mothers who smoked in pregnancy had increased risk of overweight at 5 years of age (RR 2.5, 95% CI 1.5, 4.2 for BMI; and RR 1.8, 95% CI 1.1, 3.0 for SFT). Adjusting for maternal diet, breast feeding, maternal obesity and socio-economic status did not suggest confounding. However, adjustment for birthweight increased the observed risk. A linear increase in BMI and SFT was observed with increasing number of cigarettes smoked. In conclusion, smoking during pregnancy may be a risk factor for development of childhood overweight. This study may support the hypothesis of 'fetal origin of adult disease', but the risk of overweight associated with smoking during pregnancy was independent of intrauterine growth retardation, and may thus be attributed to specific effects of cigarette smoke.     

Does childhood sexual abuse cause borderline personality disorder?

Several studies have found that women with borderline personality disorder are more likely than controls to report a history of childhood sexual abuse. Researchers have generally assumed that childhood sexual abuse causes borderline personality disorder, but there are other possible interpretations of the association. We surveyed psychologists about the likelihood that patients with various personality disorders would engage in behaviors relevant to several alternative interpretations. Relative to patients with other personality disorders and to the "typical outpatient," patients with borderline personality disorder were rated as especially likely to misinterpret or misremember social interactions, to lie manipulatively and convincingly, and to have voluntarily entered destructive sexual relationships, possibly even at young ages. We discuss the plausibility of relevant alternative interpretations of the association between childhood sexual abuse and borderline personality disorder.     

Does exercise training interfere with the effects of L-carnitine supplementation?

OBJECTIVE: We investigated the effect of L-carnitine supplementation on carnitine content in muscle fiber, glucose, and fatty acid metabolism and on performance in trained rats. METHODS: Male Wistar rats received a daily dose of 28 mg/kg, intragastrically, during the last 4 wk of a 6-wk moderate-intensity training program. The contents of carnitine and coenzyme A were evaluated in muscle fiber and its capacity to metabolize labeled glucose, oleate, and pyruvate. The ergogenic effect of the amine was assessed by the evaluation of time until exhaustion in an exercise session. The results were analyzed by analysis of variance and Tukey's post hoc test, and significance was set at P < 0.05. RESULTS: In our model, carnitine supplementation increased time until exhaustion (14.0%), similar to that observed for trained rats, but the effect was even greater (30.3% increase) in the supplemented and trained rats. Carnitine supplementation increased oleate decarboxylation (17% for sedentary rats and 119% for trained rats) and decreased glucose (29.7% and 45% for sedentary and trained rats, respectively) and [2-(14)C ]-pyruvate (45.9% and 61% for sedentary and trained rats, respectively) decarboxylation. The flux of [1-(14)C]-pyruvate through the Krebs cycle increased by 32% and 70% for supplemented sedentary and trained rats, respectively. The training protocol also increased [1-(14)C]-pyruvate decarboxylation by 32%. The cytosolic content of free, long-chain, and short-chain acyl-carnitine increased in the soleus muscle obtained from supplemented sedentary rats by 28%, 117%, and 16%, respectively, and 99%, 205%, and 32% for the muscle from supplemented trained rats. CONCLUSIONS: This study showed that carnitine supplementation increases fatty acid oxidation in skeletal muscle by a mechanism that includes increasing total carnitine content in soleus muscle mitochondria and the total content of acyl-carnitine. The most interesting finding was that the effect of supplementation was even greater in trained rats that had received 3-wk supplementation of carnitine.     

Does regular exercise reduce the pain and stiffness of osteoarthritis?

Exercise helps reduce the pain, but it's unclear whether it helps with stiffness. Exercise moderately reduces pain in elderly patients with osteoarthritis and has a small effect on reducing self-reported disability. No studies have evaluated the effect of exercise on stiffness.     

Do exercise motives predict obligatory exercise?

Few studies have examined whether factors predicting obligatory exercise differ by gender. 303 participants completed the Obligatory Exercise Questionnaire and the Reason for Exercise Inventory. All variables correlated significantly. However, the correlation between exercising for fitness and obligatory exercise was significantly stronger in women than men. In women, obligatory exercise was predicted by exercising to improve body tone, fitness, and to enhance mood; in men, obligatory exercise was predicted by exercising to improve body tone, enjoyment, and perceived attractiveness. Implications for treatment are discussed.     

Does periodontal disease cause cardiovascular disease? Analysis of epidemiological evidences

This article reports a critical analysis of epidemiologic studies that evaluated periodontal disease as a cause of cardiovascular disease. Thirty-five studies were identified through a manual search of the special abstracts volumes of the Journal of Dental Research, as well as an electronic search on MEDLINE, LILACS, and ISI and inspection of the articles' bibliographies. Inclusion criteria were: articles in any language published between 1989 and 2000 reporting the presence or absence of an association between periodontal and cardiovascular diseases. Available studies are scarce, and interpretations are limited by potential bias and confounding. The studies analyzed (whether separately or jointly) fail to provide convincing epidemiologic evidence for a causal association between periodontal and cardiovascular diseases. Although the possibility that oral diseases can cause cardiovascular diseases cannot be discarded, until better data are available, periodontal disease should not be incriminated as a cause of cardiovascular disease.     

Does low reading achievement at school entry cause conduct problems?

Conduct problems place children at increased risk for a broad array of negative health and social outcomes that include conduct disorder, injuries and violence, school failure, substance abuse, depression, and suicide. Prevention interventions have the potential to interrupt the chain of events linking early conduct problem symptoms to future negative life outcomes, but have received much less emphasis than interventions designed to treat established cases of disorder. Reading problems are a well-established correlate of conduct disorder. However, whether or not reading problems cause conduct disorder continues to be debated. If they are in fact a causal risk factor this would justify the design and evaluation of interventions designed to enhance reading skills and/or remediate problems. In this paper we use logistic regression techniques to evaluate the relation between reading achievement at school entry and conduct problems 30 months later, in a representative, non-clinic sample of kindergarten and grade one children, in Ontario, Canada. The findings show that an eight point increase in reading scores (equivalent to an moderate effect size of 0.5) would result in a 23 per cent decrease in the risk of conduct problems 30 months later, after controlling for gender, income and baseline conduct problem symptoms. We conclude that reading problems may contribute to the early onset of conduct disorder. Randomized experimental studies designed to evaluate the effects of reading programmes in non-clinic samples of children are needed to: (i) establish whether the link between reading problems at school entry and conduct disorder is causal; and (ii) determine whether reading intervention programmes are an effective conduct disorder prevention strategy.     

Does n-heptane cause peripheral neurotoxicity? A case report in a shoemaker

Subjective and electrophysiological signs relating to the centraland peripheral nervous systems developed in a shoemaker, a fewmonths after beginning work at home. Signs of central nervoussystem involvement rapidly disappeared after the end of theexposure, whereas those of mild peripheral neuropathy lastedfor several months. The glue used contained a variety of solventsincluding ethylacetate, cyclohexane, methylcyclohexane, methylethylketoneand others; n-hexane was not detected, whereas, unusually, n-heptanewas. This exposure was reproduced experimentally in the samework room and the solvent air level did not exceed the AmericanConference of Governmental Industrial Hygienists threshold values.A tentative conclusion is that the toxic effects on the peripheralnerve are likely to be due to n-heptane.     

Does medical school cause health anxiety and worry in medical students?

OBJECTIVES: The aim of this study was to investigate the self-reported experience of health anxiety and worry in medical students compared with control subjects. It was hypothesised that medical students would experience more health anxiety as a consequence of being exposed to medical education, compared to students who are not routinely exposed to such knowledge. DESIGN: The design was cross-sectional. SETTING: Participants were recruited from London University (Guy's, King's & St Thomas' School of Medicine and King's College). PARTICIPANTS: Medical students (n = 449) and non-medical students (n = 485) were recruited across Years 1-4. Questionnaires relating to health anxiety and worry were completed at the end of their lectures. MAIN OUTCOME MEASURES: Health anxiety was measured using a questionnaire known as the Health Anxiety Questionnaire (HAQ). Worry was assessed using the Anxious Thoughts Inventory (ANTI). RESULTS: Health anxiety was significantly lower in medical students in Years 1 and 4 than in controls (P = 0.017 and P < 0.001, respectively). Worry was significantly lower in the medical students in all years of study. CONCLUSIONS: Medical students are not a cohort of preselected health-anxious people, nor are they 'worriers'. Medical education at a clinical level was shown to mitigate health anxiety in the medical student population.