Increased sensitization in urban vs. rural environment – Rural protection or an urban living effect?

In a population-based longitudinal cohort study, we tested the hypothesis that children growing up in a high-traffic polluted urban area (UA) in the Athens' basin have higher prevalence of allergies and sensitization when compared with those growing up in a Greek provincial rural area (RA). We recruited 478 and 342 children aged 8-10 living in the UA and the RA, respectively. Respiratory health was assessed by a parent-completed questionnaire in three phases: 1995-96 (phase 1), 1999-2000 (phase 2), 2003-04 (phase 3) and skin-prick testing to common indoor and outdoor aeroallergens was performed at phases 1 and 2. Reported asthma and eczema did not differ between the two areas, whereas reported hay fever was persistently more prevalent in the UA than in the RA (16.5%, 17.0%, 18.2% vs. 7.0%, 8.3%, 9.6%, respectively). Sensitization was more prevalent in the UA at both phases (19.0% vs. 12.1% in phase 1, 20.0% vs. 14.1% in phase 2). Residential area contributed independently to sensitization to >or=1 aeroallergens (OR: 0.29; 95% CI: 0.13-0.66; p = 0.003) and to polysensitization (OR: 0.28; 95% CI: 0.10-0.82; p = 0.020) in phase 1. These associations were independent of farming practices. No significant contributions were found in phase 2. Our results suggest that long-term exposure to urban environment is associated with a higher prevalence of hay fever but not of asthma or eczema. The negative association between rural living and the risk of atopy during childhood, which is independent of farming practices, implies that it is mainly driven by an urban living effect.     

The functioning and well-being of depressed patients. Results from the Medical Outcomes Study

We describe the functioning and well-being of patients with depression, relative to patients with chronic medical conditions or no chronic conditions. Data are from 11,242 outpatients in three health care provision systems in three US sites. Patients with either current depressive disorder or depressive symptoms in the absence of disorder tended to have worse physical, social, and role functioning, worse perceived current health, and greater bodily pain than did patients with no chronic conditions. The poor functioning uniquely associated with depressive symptoms, with or without depressive disorder, was comparable with or worse than that uniquely associated with eight major chronic medical conditions. For example, the unique association of days in bed with depressive symptoms was significantly greater than the comparable association with hypertension, diabetes, and arthritis. Depression and chronic medical conditions had unique and additive effects on patient functioning.     

Management of major colonic haemorrhage

Major colonic haemorrhage remains a difficult diagnostic and therapeutic problem. We propose that those patients who continue to bleed after resuscitation are best served by immediate laparotomy. High flow antegrade irrigation and intra-operative colonoscopy can then be used to localize the site of bleeding and allow appropriate excisional surgery rather than blind colonic resection.     

Species- and sex-specific variations in binding of ochratoxin A by renal proteins in vitro

The mycotoxin ochratoxin A (OTA) is a potent renal carcinogen in rodents and induces renal fibrosis in pigs. Furthermore, OTA has been associated with the development of renal tumors and nephropathies in humans. Large species- and sex-differences are observed in sensitivity toward OTA-mediated toxicity and carcinogenicity, yet neither the mechanism(s) resulting in OTA toxicity nor the reasons for the observed species- and sex-specificities are known. This paper investigated variations in OTA handling viz binding to renal proteins which could possibly explain the observed differences in OTA susceptibility in vivo and in vitro. The results obtained via a modification of a standard receptor-binding assay demonstrated the presence of at least one homogeneous binding component in renal cortical homogenates from pig, mouse, rat and humans. This component was shown to bind OTA in a specific and saturable manner. A range of compounds selected for their affinity for steroid receptors and/or for various known organic anion transporters were employed in a competition assay to answer the question whether this homogenous OTA binding component represents a steroid-like receptor component or one of the known organic anion transporters of the kidney. Although many of the compounds were able to compete with OTA for protein-binding, the competition patterns displayed a distinct species specificity and did not correspond to the competition patterns associated with presently known organic anion transporters of the kidney in the mouse, rat or human. The data thus suggests the presence of a new organic anion transporter or more likely, a cytosolic binding component of unknown function with high affinity and capacity for OTA binding in humans, rats, mice and possibly pigs.     

Postnatal white matter necrosis in preterm infants.

One hundred twenty-seven infants less than 36 weeks of gestation (mean +/- SE = 31 +/- 3.2 weeks) were studied with echoencephalography to determine the incidence and complications associated with white matter necrosis. Ten infants (8%) developed cysts ten or more days after birth, indicating postnatal onset of white matter necrosis. Univariate analysis showed that postnatal white matter necrosis was significantly associated with maternal infection (other than urinary infection), respiratory distress syndrome, and longer requirement of an oxygen concentration greater than 40%. Forward logistic regression analysis showed postnatal white matter necrosis to be associated with maternal infection, chronic placental infarction, congenital pneumonia, and longer requirement of an oxygen concentration greater than 40%. Neurodevelopmental outcome was abnormal during infancy in 4 of the 6 survivors with postnatal white matter necrosis. Severe respiratory disease and maternal and/or fetal infection appear to increase the risk of the immature brain to white matter necrosis, predisposing the infants to subsequent neurodevelopmental delay.     

High energy phosphate metabolism in experimental permanent focal cerebral ischemia: an in vivo 31P magnetic resonance spectroscopy study

Relative levels of phosphate metabolites in the brain were examined in vivo by 31P magnetic resonance spectroscopy (MRS) in 50 Sprague-Dawley rats before, during, and after induction of focal permanent cerebral ischemia. After acquisition of baseline spectra, rats were subjected to injury within the core of the MR spectrometer, and 31P spectra were collected for 60 min after injury: in 7 rats, permanent, acute focal cerebral ischemia was induced (ischemia group); in 6 rats, mild hypoxia (FiO2 14%) was induced at the time of the ischemic insult and was maintained for 20 min (ischemia-hypoxia group); in 6 rats, mild hypoxia (FiO2 14%) only was induced for 20 min (hypoxia group). Control studies were performed in 25 rats. Cerebral intracellular pH, calculated from the chemical shift of inorganic phosphate (Pi), decreased immediately after injury in the ischemia and ischemia-hypoxia groups. The first 31P spectrum obtained after injury was characterized by an increase in Pi and a decrease in phosphocreatine (PCr) in the ischemia and ischemia-hypoxia groups; these changes in spectra were significantly greater in the ischemia-hypoxia group. No significant changes in adenosine triphosphate (ATP) were found in either group. Within 60 min of occlusion, 31P spectra returned toward baseline spectra in both ischemia-hypoxia and ischemia groups. No significant changes were seen in spectra of rats subjected to hypoxia alone. These results confirm that 31P MRS is a sensitive measure of early changes of high energy metabolites in focal cerebral ischemia.(ABSTRACT TRUNCATED AT 250 WORDS)     

Cardiovascular responses of pregnant women during aerobic exercise in water: a longitudinal study

To determine the effects of pregnancy on the cardiovascular responses to immersion and exercise in water, 12 women completed 20 min of immersion and 20 min of bicycle ergometry at 60% predicted VO2max in 30 degrees C water during their 15th, 25th, and 35th week of pregnancy as well as 8-10 weeks post partum. Immersion lowered the resting heart rate approximately 8 bts/min (P less than 0.05). Exercise in water also resulted in a lower heart rate as compared with the same level of exercise on land (132 +/- 4 vs 149 +/- 6 bts/min; P less than 0.05). Both the rest and exercise heart rate responses were independent of duration of pregnancy or pregnancy status. Post partum exercise cardiac output averaged 9.9 +/- 0.4 l/min, significantly lower (P less than 0.05) than the 15th (12.7 +/- 0.5), 25th (14.7 +/- 0.5), or 35th week (15.1 +/- 0.7 l/min). Total peripheral resistance was greatest (P less than 0.05) post partum (657 +/- 29 dyn.s/cm5) compared with either the 15th (515 +/- 27), 25th (407 +/- 18), or 35th week (450 +/- 23). The results indicate that exercise in water lowers the heart rate compared with land exercise at the same metabolic rate. The combined effect of exercise, water, and pregnancy may elevate the cardiac output more than expected on land, but the same general pattern of exercise response will be evident throughout the duration of pregnancy. The results further suggest that water alters the heart rate and blood pressure responses such that land-derived exercise target heart rates should not be used to prescribe exercise intensity in water.