Effects of photoisomers of cyclodiene insecticides on liver and microsomal cytochrome P450 in rats

The effects of seasonality and other temporal patterns on the occurrence of rotavirus diarrhoea were studied among hospitalised cases at Pune, India from July 1992 to June 1996. The well-accepted Box-Jenkins methodology based on modelling was employed for the analysis. This is the first presentation of such analysis for rotavirus diarrhoea. The model suggests strong influence of climatic changes on the incidence of the disease. Further study of weather parameters not only confirms that daily minimum temperature is the principal factor but also reveals that easterly wave, a characteristic feature of tropical weather, is useful in predicting the peak of hospital admissions and the geographical sequence of outbreaks of the disease in tropical India.     

Antibody responses of three Haemophilus influenzae type b conjugate vaccines after one, two and three doses in Filipino children

Differences in the magnitude of antibody response after one, two or three doses of Haemophilus influenzae type b conjugate vaccines have been reported which may influence decision-making regarding which vaccine should be used. This is of particular importance in developing countries where children may not receive a full immunization series and the vaccination schedule may be delayed. Serum antibody responses to three Hib capsular polysaccharide protein conjugate vaccines (PRP-OMP, HbOC and PRP-T) were evaluated in 102 Filipino infants. Vaccination was carried out at 6, 10 and 14 weeks of age based on the national Expanded Programme on Immunization (EPI) schedule together with diphtheria-tetanus-pertussis, hepatitis B and oral poliomyelitis vaccines. Sera were collected at 6 weeks and 1 month after each vaccination. Anti-Hib polysaccharide antibody concentrations were determined by Farrtype radioimmunoassay (RIA) and enzymeimmunoassay (EIA), Following the first dose, the geometric mean concentrations (GMC, micrograms ml-1) for PRP-OMP, HbOC and PRP-T were 0.69, 0.27 and 0.38, respectively. After two doses, there was a significant response (P < 0.05) to PRP-OMP and PRP-T (0.89 and 1.47) but not for HbOC (0.37). Differences in the GMC after the primary series were significant (pairwise P < 0.05): GMC was highest for PRP-T (4.0), followed by HbOC (1.6) and PRP-OMP (1.1). All three Hib vaccines were immunogenic when given in the local EPI schedule in Filipino infants although significant differences in the kinetics and magnitude of antibody responses were noted. The anti-Hib antibody concentrations determined by RIA and EIA were also compared in order to validate the latter for use in laboratories where it is feasible. There was a good correlation (r2 = 76%; P = 0.0001) in the Hib antibody titres obtained by both assays.     

Fatty acids as natural uncouplers preventing generation of O2.- and H2O2 by mitochondria in the resting state

Both natural (laurate) and artificial (m-chlorocarbonylcyanide phenylhydrazone; CCCP) uncouplers strongly inhibit O2.- and H2O2 formation by rat heart mitochondria oxidizing succinate. Carboxyatractylate, an ATP/ADP antiporter inhibitor, abolishes the laurate inhibition, the CCCP inhibition being unaffected. Atractylate partially releases the inhibition by laurate and decelerates the releasing effect of carboxyatractylate. GDP is much less effective than carboxyatractylate in releasing the laurate inhibition of reactive oxygen species (ROS) formation. Micromolar laurate concentrations arresting the ROS formation cause strong inhibition of reverse electron transfer from succinate to NAD+, whereas State 4 respiration and the transmembrane electric potential difference (delta psi) level are affected only slightly. It is suggested that (i) free fatty acids operate as natural 'mild uncouplers' preventing the transmembrane electrochemical H+ potential difference (delta muH+) from being above a threshold critical for ROS formation by complex I and, to a lesser degree, by complex III of the respiratory chain, and (ii) it is the ATP/ADP-antiporter, rather than uncoupling protein 2, that is mainly involved in this antioxidant mechanism of heart muscle mitochondria.     

Measurement of sialyl transferase activity and serum glycoproteins in malignant and beningn (hyperparathyroid) hypercalcemia

Serum sialyl tranferase activity (STA) and protein bound carbohydrate were measured in hypercalcemic patients with surgically documented hyperparathyroidism (n = 15) or with cancer without skeletal metastases (n = 10). Precipitable protein-bound sialic acid and hexosamine, but not neutral hexoses or fucose were significantly (P less than 0.025) increased 40% and 21% respectively, in the perchlorate treated sera of cancer patients. Measurements of some specific serum glycoproteins by radial immunodiffusion assay were also different (P less than 0.05). Mean seromucoid protein was almost twice as great in the group with cancer (P less than 0.005), but four of these values overlapped those from the patients with hyperparathyroidism. The mean STA was 21.1 (range, 9.0-46.8) activity units in the patients with the cancer and 9.2 (range 1.0-17.8) in the patients with hyperparathyroidism (P less than 0.005). Six of the patients with cancer had values above the upper limit of the group with hyperparathyroidism. A discriminant function generated from these data correctly classified all the patients with hyperparathyroidism and 70% of those with cancer. Measurements of seromucoid and STA deserve further consideration as a way to discriminate some cases of hypercalcemia.     

Clinical and experimental status of the metabolic aspects of obstructive jaundice

In the paper, the authors gave an analysis of some aspects of the metabolism in 90 patients, treated surgically for extrahepatic bile tract diseases (in 43 of them obstructive jaundice being noted), and the results of 34 experiments on white rats are summarized. Based on the conducted studies on acid-base balance, electrolyte metabolism and oxidative phosphorylation in hepatic mitochondria in the experiment under various kinds of anesthesia, some recommendations are given for including sodium oxybutyrate in anesthesia, the latter possessing a positive metabolic effect in patients with obstructive jaundice.     

Organization of patient intake at private dental institutions

Nd:YAG laser was used to disrupt Descemet's membrane in rabbits in order to provoke the hypothetical release of angiogenic activity without a significant traumatic inflammation. Corneal vascularization was elicited only with simultaneous administration of heparin, which alone was unable to initiate the growth of new blood vessels. It is probable that basic fibroblast growth factor (bFGF) was released from its depot in Descemet's membrane and its critical concentration was saved by heparin. The importance of Descemet's membrane is highlighted by the fact that a similar lesion of midstroma could not induce angiogenesis even if aided by heparin. However, some other mechanisms cannot be ruled out, as bFGF acts in paracrine and amacrine mode only.     

Flight simulator evaluation of a novel flight instrument display to minimize the risks of spatial disorientation

BACKGROUND: Melanomas arising from the mucous membranes lining the respiratory, digestive, and genitourinary tracts are rare. Women are more commonly affected than are men, mainly because there is no male counterpart for vulvovaginal lesions. The mainstay of therapy is surgery, with little current use of adjuvant modalities in primary therapy. These lesions usually are advanced at initial presentation; consequently, the prognosis is poor, with 5-year survivals well below 50% in most series. METHODS: One hundred and nineteen patients with primary mucosal melanoma were reviewed. They represented 1.1% of the 10,393 melanoma patients seen at Duke University between 1970 and 1995. All data were obtained from the patients' clinic charts and computerized databases. RESULTS: There were 43 tumors arising from the head and neck region, 46 from the urogenital tract, and 30 from the anorectum. A female predominance was observed, with a female-to-male ratio of 2.7:1. All but five of the patients underwent resection with curative intent. Regional or distant metastases, or both, were encountered in 36 patients at the time of presentation. In patients with head and neck and urogenital tumors, local recurrences accounted for most of the treatment failures, whereas systemic recurrences were more common with tumors arising in the anorectum. The age and gender of the patient, anatomic site of origin of the tumor, clinical stage at initial presentation, and ulceration of the primary all clearly affected prognosis. Overall, the probabilities of being alive 1, 5, and 10 years after diagnosis were 80%, 29%, and 15%, respectively. CONCLUSIONS: Widely accepted classification systems are needed so that results from separate institutions can be compared adequately. Multi-institutional trials could help in delineating standardized therapeutic protocols and in establishing the potential roles of emerging modalities in the treatment of this subtype of melanoma.