Reporting bias and mode of interview in a study of adverse pregnancy outcomes and water consumption.

In an earlier publication, it was shown that consumption of tapwater during the first trimester of pregnancy was associated with a risk of spontaneous abortion among women who attended three prenatal clinics located in northern California between September 1981 and June 1982. Evidence for biased recall was presented. This report demonstrates that the association is limited to women interviewed by telephone and is not observed among those who completed a mail questionnaire. The possibility that the association among women interviewed by telephone is causal and that the lack of association among mail respondents is due to bias, confounding, or apparently chance fluctuations is shown to be unlikely. For instance, the probability is low that, among mail respondents, cases underreported exposure as compared with controls or that random errors were common enough to camouflage a true effect. Demographic differences between mail and telephone respondents also do not explain the results. Interviewers were, however, aware of the outcome of the pregnancy, suggesting that differential reporting of exposure may have been stimulated in the nonblind telephone interview. The pattern of heterogeneity between mail and telephone respondents was also observed for reportable anomalies and tapwater consumption. The data on heterogeneity support the previously published conclusion that differential reporting (biased recall) of this common exposure, tapwater consumption, is the likely explanation for its observed association with the risk of spontaneous abortion. That this association is limited to telephone respondents elucidates the mechanism that apparently produced the bias: that is, the medium of nonblind telephone interviews.     

Serum ionic fluoride levels in haemodialysis and continuous ambulatory peritoneal dialysis patients

High serum fluoride (F-) in patients with chronic renal failure (CRF) and end-stage renal disease (ESRD) is associated with risk of renal osteodystrophy and other bone changes. This study was done to determine F- in normal healthy controls and patients with ESRD on haemodialysis (HD) or peritoneal dialysis (PD). Seventeen healthy controls (12 males, 5 females) and 39 ESRD patients on dialysis (17 males, 22 females) were recruited in the study in a community with 47.4 +/- 3.28 microM/l (range 44-51 microM/l) of F- content in drinking water. Control subjects showed a mean serum F- concentration of 1.08 +/- 0.350 microM/l. Males in control group showed slightly higher F- levels (1.15 +/- 0.334, range 0.55-1.9 microM/l) than females (0.92 +/- 0.370, range 0.6-1.5 microM/l). Mean serum F- concentration did not correlate significantly with age and sex among control subjects, whereas such correlation was observed in patients with ESRD on dialysis. Mean serum F- concentration was significantly higher in patients on dialysis (2.67 +/- 1.09, range 0.8-5.2 microM/l) than normal controls. When grouped according to sex, the mean serum F- concentration in males (3.05 +/- 1.04, range 1.8-5.2 microM/l) was significantly higher than females (2.38 +/- 1.08, range 0.8-5.2 microM/l). When patients were grouped according to age, it was observed that F- concentration was significantly higher in patients with age groups 21-70 (2.86 +/- 1.05) than those with age group 13-20 years (1.42 +/- 0.531). Thus F- concentration correlated with age and sex, being higher in males and above 20 years. Despite appreciable clearance of F- (39-90%) across the peritoneum, patients on CAPD showed higher serum F- concentration than those on HD (3.1 +/- 1.97 vs 2.5 +/- 1.137 microM/l). Of the total 39 patients on dialysis 39% had their serum F- concentration above 3.0 microM/l, posing the risk of renal osteodystrophy.      

Redistribution of transmitter amino acids in rat hippocampus and cerebellum during seizures induced by L-allylglycine and bicuculline: an immunocytochemical study with antisera against conjugated GABA, glutamate and aspartate

The effects of the convulsants L-allylglycine and bicuculline on the distribution of gamma-amino-butyric acid (GABA), glutamate and aspartate in rat brains were assessed immunocytochemically, using antisera raised against glutaraldehyde-protein conjugates of the respective amino acids. In accord with previous biochemical studies of GABA content, L-allylglycine treatment was followed by a decreased immunoreactivity for GABA in the hippocampus and cerebellum, whereas treatment with bicuculline led to an increased immunoreactivity in the hippocampus, but not in the cerebellum. Different cells and zones were affected differentially. With both convulsants the hippocampus showed the most pronounced changes in the neuropil of the pyramidal and granular cell layers. L-Allylglycine treatment led to a substantial decrease in the concentration of detectable GABA-immunoreactive bouton-like dots in the stratum oriens, radiatum and lacunosum-moleculare and in the deep hilar region, but did not produce statistically significant changes in this parameter in the outer and intermediate zones of the dentate molecular layer. In the cerebellum, the decrease in GABA immunoreactivity after L-allylglycine treatment was less in the basket cell terminals than in other GABA-containing elements. Neither convulsant altered the average staining intensity for aspartate or glutamate in the two regions studied, but L-allylglycine reduced the level of aspartate-like immunoreactivity in hippocampal hilar cells. All the changes described were evident after 20 min of seizure activity and were qualitatively similar after 60 min of seizure (animals paralysed and ventilated). Our results indicate that L-allylglycine or bicuculline given intravenously exerts specific effects on cerebral amino acid metabolism. The nature and magnitude of these effects show inter-regional variations and also differ among cellular compartments within each region. Amino acid immunocytochemistry may prove to be a valuable tool for the investigation of metabolic changes associated with epileptic seizures and should be particularly useful in regions showing heterogeneous changes that would tend to cancel each other in biochemical analyses.     

44Sacral extracorporeal magnetic stimulation is an effective treatment for pelvic floor dyssynergia; Comparative study with biofeedback therapy

Background: Recent development of extracorporeal magnetic stimulation (ECMS) which uses current‐changing magnetic fields allows the induction of electrical stimulation in the desired deep tissue. Recent study showed the sacral nerve stimulation reduces corticoanal excitability that may play a functional role in anal continence mechanisms. Preliminary study shows that ECMS of sacral nerve can modify pelvic floor function and expel rectal balloon in patients with pelvic floor dyssynergia (PFD). Aims: To evaluate the effect of ECMS compared with biofeedback therapy (BF) in patients with PFD. Methods and Materials: Thirty‐eight patients who fulfilled Rome II criteria for PFD by colon transit time and anorectal function tests, were randomly treated with 8 sessions of ECMS (2/weeks; n = 19) at prone position or BF (2/weeks; n = 19) at sitting position. Stimulation parameters were set at 50–80% of maximum intensity, 10 and 50 Hz frequency, 3 s burst length with 3 and 6 s off using arm‐typed stimulator (BioCom‐1000, Mcube Co., Korea). Symptom scores for constipation with/without anorectal function test were repeatedly measured after each treatment. Response was defined as 50% or more decreased symptom score after treatment (partial response: 30–50%, poor: <30%). Results: Fifteen patients (age 49.1 ± 13.4 years, mean ± SD; 4 men) completed 8 session of BF and 14 patients (54.5 ± 17.6 years, 3 men) completed 8 session of ECMS. Four patients of BF group discontinued treatment due to unsatisfactory therapeutic effect (n = 1) and withdrew consent (n = 3) and 5 patients of ECMS group discontinued treatment because of same reasons (n = 1, 4). Total symptom scores were significantly decreased after treatment of 8 session in both treatment groups (13.4 ± 6.6 vs. 4.3 ± 4.0 for BF, p = 0.009; 14.9 ± 5.6 vs. 3.4 ± 4.0 for ECMS, p < 0.001). Bowel movements per week were also significantly increased after treatment in both groups (median 2 vs. 7 for BF, p = 0.035; median 2 vs. 7 for ECMS, p = 0.008). Thirteen out of 15 patients showed response in BF group and 12 out of 14 showed good response in ECMS group. No adverse effects in both groups. Conclusions: ECMS is as effective as BF for the treatment of PFD. Long‐term effect of ECMS for the patients with pelvic floor dyssynergia need to be evaluated in the near future.