Background and aims: This was a prospective blinded study to compare computed tomography (CT) colonography, performed with multidetector arrays CT scan (MDCT), with conventional colonoscopy for the detection of colorectal neoplasia. Methods: Fifty patients were examined by MDCT after standard bowel preparation and rectal air insufflation in the supine and prone positions. Data sets were examined by one radiologist and one gastroenterologist blinded to the patient's history and colonoscopy results. Patients subsequently underwent colonoscopy on the same day, which served as the gold standard. Results: Nine of 11 lesions >10 mm (82%), 5/15 lesions of 6-9 mm (33%), and 1/42 polyps <5 mm (3%) were detected by MDCT colonography. One false positive result for a structure larger than 10 mm was described. Nineteen of 21 patients who had no lesions during conventional colonoscopy were considered free of lesions by MDCT colonography, yielding a per patient specificity of 90%. Conclusion: MDCT colonography provides good data quality and has good sensitivity and specificity for the detection of colonic lesions of 10 mm or more.

We found a low prevalence (10%) of malnourished patients on admission. Clinical judgment and to some extent anthropometrical measurement were helpful for assessing the nutritional status, laboratory values were not.

Sex determination in Drosophila depends on the ratio of X chromosomes to sets of autosomes (X: A). This chromosomal signal is used to regulate a few control genes whose state of activity selects either the male or the female sexual pathway. We have studied the structure and function of dsx (double sex) which appears to be the last regulatory gene on whose function the sexual pathway eventually depends. We have mutagenized the locus, varied the doses of dominant dsxmutations and wildtype alleles, and combined different Ax-alleles with recessive mutations in other sex-determining genes, such as ix, tra-2 and tra.The locus dsx harbours two genetic functions, dsx m to implement the male program, dsx' to implement the female program. We found that dsx m and dsx' can mutate independently although most mutations abolish both functions. We conclude that dsx m and dsx' each have their specific domain, but also share a large region of DNA that is essential for both functions. We present evidence that the dominant mutations correspond to a constitutive expression of the maledetermining function dsx m , with the simultaneous abolishment of the female-determining function dsx ! . This effect can be counteracted by two doses of expressed dsx' so that a female phenotype results. The products of one dose of expressed dsx m and one dose of expressed dsx' in the same cell appear to neutralize each other which leads to a null phenotype. The mutant combinations suggest that the product of dsx' requires the products of ix + , tra-2 + and tra + to become functional.

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Helicobacter pylori infection induces an important systemic and mucosal antibody response and a predominant Th1 cellular response. These immune responses, although powerful, fail to eliminate the infection. Studies in animals have shown that prophylactic and therapeutic immunisations are efficacious, although complete protective immunity has usually not been achieved. Initial human trials with recombinant urease showed that a mucosal immune response can be obtained following immunisations, with a decrease in bacterial density, but successful immunisation is still awaited. Progress is being made in several areas of vaccine design. A human vaccine against H. pylori would be favourable in terms of health benefits and costs in developed and developing countries.