Carcinoma of the stomach following the Chernobyl nuclear accident

Medical consequences of many nuclear accidents on humans are well studied, but the results pertaining to gastric cancer patients who were exposed to radiation as a result of the Chernobyl nuclear accident have not been analysed. In this study, the outcome of the surgical treatment of 68 gastric cancer patients who were exposed to radiation as a result of the Chernobyl nuclear accident was compared with that of 117 consecutive gastric cancer patients from uncontaminated areas of the Ukraine. Patients in the study group was significantly younger than that of the control group. Comparative analysis showed the same frequency of regional metastases (65.7% versus 71.1%, P > 0.05), but a smaller number of distant metastases (23.8% versus 38.1%, P < 0.05) in the study group. 41.2% of patients in the study group underwent total gastrectomy compared to 19.6% of patients in the control group (P = 0.002). Postoperative complications developed in 13.2% of patients in the study group, while postoperative mortality in the study group was 7.3% compared to 1.7% in the control group. A significant decrease in CD16 cells was noted in patients from the study group following the operative procedure. Young age, invasive tumours with smaller number of distant metastases, frequent necessity for total gastrectomy and combined operations with adjacent organs, a higher level of postoperative morbidity and mortality and low levels of natural killer cells (CD16+) with a tendency to decrease after surgery are characteristic of patients with carcinoma of the stomach affected by the Chernobyl accident.     

Overestimate of vaccine coverage? New evidence from a survey in Pau da Lima]

To evaluate vaccination coverage in children 0 to 5 years of age, a cross-sectional study based on a household survey was carried out in 1992 in the Pau de Lima Health District, Salvador, Bahia, Brazil, using a cluster sampling technique. The district was subdivided into 30 small areas that were homogeneous with respect to socioeconomic characteristics. Information on the vaccination status of 385 children was obtained through verification of a vaccination card or campaign voucher, or, in the absence of these items, through verbal confirmation from the mother or other responsible person. Based on all the sources of information, the study found vaccination coverage rates in the entire age range of 69% for polio vaccine; 56% for DTP; 74% for measles vaccine; and 87% for BCG. These results suggest that rates obtained from routine records of the health services and vaccination campaigns may be overestimates. The authors discuss the implications of the low coverage rates found in the entire age group and especially among children under 1 year old.     

Auditory evoked potentials during multichannel selective listening: role of pitch and localization cues

Auditory evoked potentials were recorded from subjects who listened selectively to tone pips arriving over one of three input channels. Their task was to detect occasional target tones of a slightly longer duration. In different runs the three channels were distinguished from one another by (a) pitch cues alone (800, 1,800, and 2,800 Hz), (b) localization cues alone (right ear, midline, ane left ear), and (c) both of these cues conjointly. In all three conditions the direction of attention was reflected in the amplitude of the N1 wave of the evoked potential, which was selectively enhanced to tones in the attended channel; tones in the central channels in the single-cue conditions, however, produced the least N1 lability and were the least discriminable. The N1 wave was interpreted as a sign of an initial stimulus set or filtering mode of selective attention, whereas a subsequent P3 wave was specifically associated with detections of the target stimuli.     

Effectiveness of external decompression of the biliary tract in middle-aged and old persons with cholecystitis

It was shown that parenteral administration of lead ions caused in the blood serum of albino mice a significant decrease in the amount of the bound RNA-ase 1 inhibitor and a simultaneous increase in the activity of this enzyme. Consequently, this inhibitor served as a regulator of the serum RNA-ase 1 activity. A considerable increase in the amount of the bound and free RNA-ase 1 inhibitor was noted in the serum in the process of triple immunization of persons with live influenza vaccine; this was accompanied by a significant reduction of the free RNA-ase 1 activity. This indicated that along with other mechanisms the inhibitor apparently participated in the processes of formation of immunity against influenza.     

Partial activation of CD8+ T cells by a self-derived peptide

T cells are normally activated when the peptide for which they are specific is presented to them in the context of the appropriate major histocompatibility complex (MHC) (class I and Class II for CD8+ and CD4+ T cells, respectively). An increasing body of evidence indicates that structural homologues of the immunogenic peptide can partially activate or antagonize CD4+ T cells. CD8+ T cells may also be partially antagonized by such peptides, and self-derived peptides of this type may play a role in CD8+ T cell selection in the thymus. Activated CD8+ T cells lyse their targets by perforin-dependent granule exocytosis and by inducing apoptosis mediated by CD95 (also known as Fas or APO1) with its ligand (CD95L). Here we show that a clone of Kd-restricted CD8+ T cells specific for influenza haemagglutinin, which can also be activated in a crossreactive manner by a peptide derived from a myeloma tumour immunoglobulin heavy-chain variable region (IgVH) to kill by both routes, kills only by the CD95-CD95L pathway when stimulated by the corresponding germline IgVH peptide. As this germline IgVH peptide differs from the tumour peptide only at a single position buried in the MHC-binding groove, this indicates that CD95-CD95L-mediated killing can be triggered independently of the perforin-mediated pathway, and can be selectively affected by changes in MHC conformation.