Magnified examination of small colorectal polyps using a prototype electronic endoscope.

Magnifying electronic endoscopes are frequently used to evaluate the pit patterns of the colorectal mucosa, but such endoscopes suffer from a number of problems. For example, they tend to have long, hard tips and heavy controller sections. In addition, the magnified endoscopic images obtained are often quite coarse due to the small number of pixels in the charge-coupled device (CCD). As a result, at higher magnification ratios, the orientation of the field of view is easily lost. A newly developed prototype colorectal electronic endoscope (Toshiba Corporation, Tokyo) overcomes these problems. The length of the hard tip of the scope and the weight of the controller section are comparable to those of the TCE-3680MH (Toshiba Corporation). High-resolution magnified images can be obtained, because a 410,000-pixel CCD is employed. Two magnification methods are available, optical magnification and electronic zooming, permitting images to be magnified by a factor of up to 90-120 without losing the orientation of the field of view. This newly developed magnifying electronic endoscope was found to be very useful, allowing us to observe the pit patterns of the colorectal mucosa in 82 small colorectal polyps measuring 7 mm or less in diameter.

Alteration of natural killer cell subsets (two color analysis) and their activity in peripheral blood in inflammatory bowel disease.

The natural killer (NK) activity and NK cell subsets in peripheral blood were evaluated in patients with inflammatory bowel disease (IBD), by using 51Cr release cytotoxicity assay and two color flowcytometry analysis. The peripheral blood NK activity was significantly lower in IBD than that in normal controls. This decrease of the NK activity was independent on the disease activity of IBD but dependent on the steroid medication. The total population of NK cells (Leu 7+ or 11c+ cells) did not change in IBD as compared with those of normal controls. However, the proportions of Leu7+11c- cells and Leu7-11c+ cells in IBD were higher and lower, respectively as compared with those of normal controls. These findings suggest that the maturation step of NK cell lineages might be impaired in IBD. The decrease of NK activity in IBD was supported by the change in the proportion of NK cell subsets described above. It was thought that such a change in NK cell subsets might be a specific finding in IBD patients, because it was not observed in patients with non-IBD colitis.

Surveillance of listeriosis in Los Angeles County, 1985-1986. A first year's report.

After a large food-borne outbreak of listeriosis in Los Angeles County, California, in 1985, the California State Department of Health Services instituted mandatory reporting of Listeria monocytogenes by clinical laboratories. From September 1, 1985, through August 31, 1986, 94 cases of listeriosis were reported in Los Angeles County for an annual crude incidence rate of 12 cases per million persons. Of the 94 cases, 37 (39%) were in neonates and/or their mothers and 57 (61%) were nonperinatal. The overall case fatality rate was 31%, with a perinatal case fatality of 16% (6 fetal and 23 nonperinatal); this compares with an epidemic perinatal case fatality rate of 32%. No significant differences were observed in age-adjusted, race-specific incidence rates among nonperinatal cases or race-specific incidence rates among perinatal cases. All but 2 of the nonperinatal patients had a known predisposing risk factor for the development of listeriosis, the most common of which was a prior history of steroid therapy. A clustering of cases was not identified. No common food sources were apparent. Patients presenting as perinatal cases were more likely to have ingested Mexican-style cheese, ice cream, and yogurt than those presenting as nonperinatal cases. Improved case ascertainment through mandatory reporting and laboratory-based surveillance will establish meaningful baseline levels of listeriosis.

HIV seroprevalence in intravenous drug users: Los Angeles, California, 1986.

To estimate the seroprevalence and investigate risk behaviors for HIV (human immunodeficiency virus) infection in intravenous drug users in Los Angeles County, a stratified, random sample of 790 clients, enrolled in either methadone maintenance or detoxification programs, were studied. Thirteen study participants (1.8 per cent) were seropositive; of these, five were homosexual/bisexual males and three were female prostitutes. Ninety-five per cent of all participants reported sharing needles. Risk reduction education efforts must be expanded before the HIV antibody prevalence rate increases.

Comparison of visual estimate with digital caliper measurement of coronary artery stenosis.

We compared visual estimate and digital caliper measurement of coronary stenoses, utilizing both a 50% and 70% diameter reduction as a definition of significance and both experienced angiographers and cardiology fellows as readers. Ten angiograms were interpreted twice, using the different methods, by four readers, two months apart. The angiograms were divided into 12 vessel segments. Stenoses were judged more severe by visual estimate in 11 segments. Seven of twelve segments had significant differences between readers using the visual estimate, but no significant differences were obtained using caliper measurements. Variability was highest for fellows using the visual method. Interobserver agreement was highest using the digital caliper and the 70% criteria. Intraobserver agreement was most dependent on the amount of time taken in film interpretation. The digital caliper appears to be preferable in interpreting angiograms, particularly for cardiology fellows.