Regression of childhood Barrett's esophageal mucosa by antireflux surgery and bipolar electrocoagulation

The authors report a case of a 13-year-old girl with Barrett's esophagus who underwent antireflux surgery and was subsequently treated with endoscopic thermal coagulation using bipolar electrocoagulation. Follow-up endoscopy 15 months after completion of the endoscopic therapy showed normal esophageal mucosa without intestinal metaplasia. Longer follow-up is needed to assess the long-term effects of endoscopic treatment of the Barrett's mucosa with thermal coagulation, and this procedure should still be considered under investigation.     

First trimester maternal serum concentrations of fetal antigen 2 in normal pregnancies and those affected by trisomy 21

Serum concentrations of fetal antigen 2 (FA-2), the amino-propeptide of the alpha1 chain of collagen type I, were measured in peripheral blood from women with normal (n = 234) and trisomy 21 affected (n = 14) pregnancies between 9 and 11 weeks gestation. Serum FA-2 concentrations were seen to be stable throughout this period, and though raised FA-2 concentrations were seen at the 10th week of gestation, a statistically significant difference between normal and trisomy 21 affected pregnancies was not found overall. Therefore it seems unlikely that FA-2 has a role in first trimester screening for trisomy 21, despite the fact that significantly higher FA-2 concentrations in trisomy 21 and significantly lower concentrations in trisomy 18 had been previously demonstrated in amniotic fluid in the second trimester.     

Gamma-spectroscopy investigation of radon daughter deposition on electrostatically charged surfaces

The effect of static electricity on the deposition of radon daughters onto charged surfaces is determined by a combined experimental and theoretical analysis. Experiments with charged surfaces exposed to the air in a normal working environment are analysed to determine an empirical radon daughter deposition rate. This factor is utilized to estimate the daughter deposition on a human head which is exposed to similar conditions of air quality and static charging. The results indicate that typical levels of static electricity can enhance the deposition of radon daughters by orders of magnitude compared with the uncharged condition. The corresponding yearly alpha dose equivalents to the basal skin layer and to the eye exceed recommended limits. Beside having an important impact from the public health perspective, these results suggest that the obscure and contradictory correlations found between radon concentrations and adverse health effects may arise from a failure to account for the effects of static electricity.     

Ventilatory management in the postanesthesia care unit

Postoperative ventilatory depression is common in patients who have received intravenous and inhalational anesthetic agents. Prompt assessment and treatment of ventilatory depression are essential to minimize morbidity and mortality.     

Seasonal weight loss and metabolic adaptation in rural Beninese women: the relationship with body mass index

A large variation in seasonal weight loss between individuals exists in rural communities in developing countries. Therefore, it was investigated whether some individuals show a metabolic adaptation and, through that, prevent large body-weight losses during the preharvest season. Basal metabolic rate (BMR), energy intake and physical activity level (PAL) of rural Beninese women were measured in three seasons. Groups of subjects were: women with a body mass index (BMI) < 18 (n 18), and a BMI > 23 (n 16), and women who had shown small (n 18) and large (n 15) preharvest weight loss. All groups of subjects decreased energy intake during the preharvest season by 0.66-1.09 MJ/d. PAL did not show significant seasonal changes in any of the four groups. Only subjects with a BMI < 18 decreased BMR during the preharvest season with 2.9 (SD 6.7) J/kg per min (P < 0.05), with a decrease of 0.8 (SD 1.4) kg (P < 0.05) in body weight. In very thin women with a BMI < 17 (n 5) BMR expressed per unit body weight decreased even more during the preharvest season (by 12%).     

3-Methyleneoctanoyl-CoA and 3-methyl-trans-2-octenoyl-CoA: two new mechanism-based inhibitors of medium chain acyl-CoA dehydrogenase from pig kidney

The medium chain acyl-CoA dehydrogenase catalyzes the FAD-dependent oxidation of a variety of acyl-CoA substrates to the corresponding trans-2-enoyl-CoA thioesters. This work identifies 3-methyleneoctanoyl-CoA and 3-methyl-trans-2-octenoyl-CoA as representatives of a new class of mechanism-based inhibitor of the dehydrogenase. One equivalent of either compound generates an inactive reduced flavin species with low absorption at 450 nm and a shoulder at 320 nm suggestive of an N-5 adduct. Reduction is rapid with the 3-methylene analogue (10/s at 1 degree C), but comparatively slow for 3-methyl-trans-2-octenoyl-CoA (1.1 x 10(-4)/s, under the same conditions). The reduced species is very stable, but the adduct can be slowly displaced with a large excess of octanoyl-CoA. The reduced adduct resists oxidation by the facile one-electron oxidant of the dehydrogenase, ferricenium hexafluorophosphate. Evidence that both isomeric inhibitors generate the same reduced flavin species includes an essentially identical visible spectrum, the same kinetics of displacement using octanoyl-CoA, and the same mixture of products on HPLC after denaturation of the treated enzyme with trichloroacetic acid, methanol, or by boiling. Experiments with the corresponding shorter analogues of these inhibitors, 3-methylenebutanoyl-CoA and 3-methyl-2-butenoyl-CoA confirm and extend these findings. These reduced adducts are less stable, allowing the dehydrogenase to catalyze the interconversion of the unconjugated 3-methylenebutanoyl-CoA to the more stable conjugated 3-methyl-2-butenoyl-CoA thioester (Keq ca. 150). These data suggest that alpha-proton abstraction from the 3-methylene derivatives or gamma-proton removal from the 3-methyl-2-enoyl analogues generates a common carbanionic intermediate which attacks oxidized flavin. As would be expected, the unconjugated 3-methylene derivatives are more effective inhibitors of the dehydrogenase than the thermodynamically more stable 3-methylenoyl analogues.     

Non-penetrance and late appearance of polyps in families with familial adenomatous polyposis

One case of non-penetrance of the familial adenomatous polyposis (FAP) gene at 59 years of age and late onset of polyps on endoscopy and biopsy in this and two other families is described. Screening protocols should include dental screening as well as indirect ophthalmoscopy and endoscopy to detect minimal manifestations of the gene. In the absence of a specific DNA predictive test, bowel screening should continue well beyond 30 years of age.