Non-hierarchical logistic models and case-only designs for assessing susceptibility in population-based case-control studies

Mechanisms for the abnormal copper (Cu) accumulation in the liver of LEC rats were examined using primary cultured liver parenchymal cells prepared from mutant LEC rats and those from control LEA rats (original strain). The Cu and metallothionein (MT) mRNA levels in the liver of LEC rats were caused to decrease to the same levels as those of LEA rats by removing Cu in vivo selectively with tetrathiomolybdate. Cu was taken up by LEC rat cells to the same extent as LEA rat cells by exposure to low medium Cu and to a higher extent by exposure to high medium Cu, while the MT mRNA level in LEC rat cells increased dose-dependently at a much higher rate than that in LEA rats. MT mRNA levels in both cells were comparable by exposure to cadmium, zinc and dexamethasone. The results indicate that expression of MT mRNA is selectively enhanced by Cu in LEC cells despite the fact that uptake of Cu is comparable with normal cells.     

The role of dietary fiber in the etiology of non-insulin-dependent diabetes mellitus. The San Luis Valley Diabetes Study

Accuracy of patient positioning and dose delivery in mantle field irradiations was investigated on 29 patients treated between August 1990 and December 1991. Patients were treated in two different centers, University Hospital St. Rafa?l in Leuven and Institut Gustave Roussy in Villejuif, where different techniques and procedures were used. Measurements were performed on 341 portal films and entrance doses were measured in 518 treatment set-ups. The impact of systematic errors occurring during treatment preparation and day-to-day variations on the accuracy of treatment execution were separately analysed. Daily reproducibility, defined as the deviation from the respective mean measured value for a treatment was demonstrated to be good for both the treated volume and the delivered dose and no difference between the two techniques was shown. Comparing the successive portal films of individual patients (reproducibility of a treatment, once it has started), only small day-to-day variations are found: the SD is 3.4 mm for craniocaudal movements and 2.6 mm for lateral movements. For dose delivery very narrow distributions are obtained with SDs of, respectively, 1.5% and 1.85% for the Leuven and the Villejuif group. This suggests that the position of the patient, which is often thought as the critical point in this complex set-up can be done in a very accurate way, regardless of the position used. To assess the global accuracy of the treatment, the actually treated volume and delivered dose were compared with the planned values. Apart from reproducibility this also takes into account the whole preparatory procedure between planning and the start of the therapy (first session).(ABSTRACT TRUNCATED AT 250 WORDS)     

Cotrel-Dubousset instrumentation. Results in 52 patients

Fifty-two posterior spinal fusions were performed for pediatric idiopathic, congenital, and neuromuscular scoliotic curves. Cotrel-Dubousset instrumentation was used in all patients. Nine had prior anterior spinal releases and fusions. The patterns were mixed, with a predominance of right thoracic curvatures. The average preoperative curve measured 60.6 degrees, with correction to 29. Seven patients required revision surgery, and 17 wore orthoses after operation. There were 17 complications in this group, including hook pullout, prominent hardware, infection, pseudarthrosis, and two cases of broken Cotrel-Dubousset instrumentation rods. Fatigue failure of this instrumentation, secondary to pseudarthrosis, has not been reported previously, and these two cases are presented in detail. The operative morbidity and difficulty were increased in the larger idiopathic curves and in neuromuscular and congenital scoliosis. Cotrel-Dubousset instrumentation is an overall excellent tool for the multiplanar correction of scoliosis and is amenable to revision surgery.     

Item bias in cognitive screening measures: comparisons of elderly white, Afro-American, Hispanic and high and low education subgroups

A study of item bias in standard cognitive screening measures was conducted in a sample of Afro-American, Hispanic and non-Hispanic white elderly respondents who were part of a dementia case registry study. The methods of item-response theory were applied to identify biased items. Both cross-cultural and high and low education groups were examined to determine which items were biased. Out of 50 cognitive items examined from six widely used cognitive screening measures, 16 were identified as biased for either high and low education groups or ethnic/racial group membership.