Measurement of mesothelioma on thoracic CT scans: a comparison of manual and computer-assisted techniques

Our purpose in this study was to evaluate the variability of manual mesothelioma tumor thickness measurements in computed tomography (CT) scans and to assess the relative performance of six computerized measurement algorithms. The CT scans of 22 patients with malignant pleural mesothelioma were collected. In each scan, an initial observer identified up to three sites in each of three CT sections at which tumor thickness measurements were to be made. At each site, five observers manually measured tumor thickness through a computer interface. Three observers repeated these measurements during three separate sessions. Inter- and intra-observer variability in the manual measurement of tumor thickness was assessed. Six automated measurement algorithms were developed based on the geometric relationship between a specified measurement site and the automatically extracted lung regions. Computer-generated measurements were compared with manual measurements. The tumor thickness measurements of different observers were highly correlated (r > or = 0.99); however, the 95% limits of agreement for relative inter-observer difference spanned a range of 30%. Tumor thickness measurements generated by the computer algorithms also correlated highly with the average of observer measurements (r > or = 0.93). We have developed computerized techniques for the measurement of mesothelioma tumor thickness in CT scans. These techniques achieved varying levels of agreement with measurements made by human observers.     

Electron microscopic studies of endocrine hyperplasia in duodenal adenomas in familial adenomatous polyposis

Summary Electron microscopical studies on endocrine cell hyperplasia of duodenal adenomas from five patients with familial adenomatous polyposis were performed. All the endocrine cell types normally found in the duodenal mucosa were identified. A constant feature was proliferation of duodenal-enterochromaffin cells but an increase in the number of all other endocrine cell types apart from pyloricgastrin cells and somatostatin cells, was also observed. Certain types of intestinal endocrine cells (the intestinal enterochromaffin cell and the glicentin cell) are rare cells in the normal duodenal mucosa. The finding of these cells may indicate increased biological aggressivity.     

Suggestions for the assessment of the allergenic potential of genetically modified organisms

The prevalence of allergic diseases has been increasing continuously and, accordingly, there is a great desire to evaluate the allergenic potential of components in our daily environment (e.g., food). Although there is almost no scientific evidence that genetically modified organisms (GMOs) exhibit increased allergenicity compared with the corresponding wild type significant concerns have been raised regarding this matter. In principle, it is possible that the allergenic potential of GMOs may be increased due to the introduction of potential foreign allergens, to potentially upregulated expression of allergenic components caused by the modification of the wild type organism or to different means of exposure. According to the current practice, the proteins to be introduced into a GMO are evaluated for their physiochemical properties, sequence homology with known allergens and occasionally regarding their allergenic activity. We discuss why these current rules and procedures cannot predict or exclude the allergenicity of a given GMO with certainty. As an alternative we suggest to improve the current evaluation by an experimental comparison of the wild-type organism with the whole GMO regarding their potential to elicit reactions in allergic individuals and to induce de novo sensitizations. We also recommend that the suggested assessment procedures be equally applied to GMOs as well as to natural cultivars in order to establish effective measures for allergy prevention.     

Five year study of prenatal testing for Huntington''s disease: demand, attitudes, and psychological assessment.

Adult predictive and prenatal testing programmes for Huntington's disease (HD) in Canada have been available since 1986. However, the demand for prenatal testing and the reasons why some people choose not to have the prenatal test for this late onset disorder have not been well documented. In addition, the knowledge and attitudes of adult predictive testing candidates and their partners about prenatal testing are not well known nor are the psychological effects of prenatal testing well understood. As of September 1991, 425 subjects had entered the Canadian Collaborative Study of Predictive Testing and, of these, 47 subjects or their partners had become pregnant. Of this group, 14 (30%) couples requested prenatal testing, 24 (51%) couples did not want prenatal testing, and nine (19%) at risk subjects had already received a decreased risk through adult predictive testing and, therefore, were not eligible for the prenatal test. Of the 14 couples who initially requested prenatal testing, seven withdrew. Thus, demand for the prenatal test by eligible candidates was 7/38 or 18%, which is much lower than the 32 to 65% expected based on early survey data. The most frequently cited reason for declining prenatal testing was the hope that a cure would be found in time for their children. While the majority of adult predictive testing candidates (71%) in our study had accurate information about definitive prenatal testing, many (63%) did not have a correct understanding of exclusion prenatal testing. Although no serious adverse events such as suicide planning or admission to psychiatric hospital have occurred, a particular need for careful counselling was identified for those at risk candidates and their partners who have one prenatal test and feel compelled to use the test again in future pregnancies. Even though prenatal testing for HD is not requested as often originally expected, it still remains a desired option for some at risk persons and their partners.     

Miscarriage rates following in-vitro fertilization are increased in women with polycystic ovaries and reduced by pituitary desensitization with buserelin

To assess the risk of miscarriage after in-vitro fertilization(IVF) with respect to age, cause of infertility, ovarian morphologyand treatment regimen, a retrospective analysis was performedof the first 1060 pregnancies conceived between June 1984 andJuly 1990 as a result of 7623 IVF cycles. Superovulation inductionwas achieved with human menopausal gonadotrophin (HMG) and/orpurified follicle stimulating hormone (FSH) together with eitherclomiphene citrate or the gonadotrophin hormone-releasing hormone(GnRH) agonist buserelin, the latter either as a short ‘flare’regimen or as a ‘long’ regimen to induce pituitarydesensitization. There were 282 spontaneous abortions (26.6%)and 54 ectopic pregnancies (5.1%). The mean age of women withongoing pregnancies was 32.2 (SD 3.9) years compared with 33.2(SD 4.1) years in those who miscarried, which were significantlydifferent (P = 0.008). There was no relation between the miscarriagerate and the indication for IVF. The miscarriage rate was 23.6%in women with normal ovaries compared with 35.8% in those withpolycystic ovaries [P = 0.0038, 95% confidence interval (CI)4.68–23.10%]. There was no difference in the miscarriagerate between treatment with HMG or FSH. Women whose ovarieswere normal on ultrasound were just as likely to miscarry ifthey were treated with clomiphene or with the long buserelinprotocol. Those with polycystic ovaries, however, had a significantreduction in the rate of miscarriage when treated with the longbuserelin protocol, 20.3% (15/74), compared with clomiphenecitrate, 47.2% (51/108) (P = 0.0003, 95% CI 13.82–40.09%).     

Global molecular epidemiology of the O15:K52:H1 extraintestinal pathogenic Escherichia coli clonal group: evidence of distribution beyond Europe

Escherichia coli O15:K52:H1 is a significant extraintestinal pathogen in Europe (G. Prats et al., J. Clin. Microbiol. 38:201-209, 2000). To search for evidence of this clonal group outside of Europe, 75 non-European E. coli isolates of serogroup O15 were compared with five members of the O15:K52:H1 clonal group from Barcelona, Spain, according to genomic background, virulence genotypes, and antimicrobial resistance profiles. Amplification phylotyping showed that 16 (21%) of the 75 non-European O15 isolates corresponded with the O15:K52:H1 clonal group. The 16 non-European O15:K52:H1 clonal group members represented diverse geographic locales. They were isolated almost exclusively from humans with extraintestinal infections and accounted for 50% of all O15 isolates from five human clinical collections studied. Most non-European clonal group members exhibited a consensus virulence factor profile that included the F16 or F7-2 papA alleles (P fimbrial structural subunit), papG allele II (P fimbrial adhesin), iha (putative adhesin siderophore), and iutA (aerobactin receptor). This resembles the virulence profiles of (i) European representatives of the O15:K52:H1 clonal group and (ii) phylogenetically related "clonal group A," a recently recognized significant contributor to trimethoprim-sulfamethoxazole resistance in the United States (A. R. Manges et al., N. Engl. J. Med. 345:1007-1013, 2001). Antimicrobial resistance profiles were variable, and resistance was inconsistently transferred by conjugation. These findings indicate that the O15:K52:H1 clonal group is broadly distributed beyond Europe, exhibits previously unrecognized phenotypic and genotypic diversity, and contributes significantly to extraintestinal infections in humans.