Some metabolic changes during human corneal organ culture

In order to evaluate the changes in medium composition during closed system corneal organ culture at 30 degrees C, pH, pO2, glucose and lactate was measured 1 to 7, 14 and 28 days after incubation of a total of 49 human corneas. During organ culture pO2 decreased from 17.3 kPa to 8.8 kPa at day 28. The average oxygen consumption was initially 0.16 mumole/h/cm2, but decreased rapidly to an average of 0.04 mumole/h/cm2 during the first weeks of incubation. The glucose concentration fell from 5.1 mM to 0.25 mM after 28 days, and the lactate concentration rose from 2.5 mM to 11 mM. The concentration changes were for both substances highest during the first 14 days of organ culture. The pH fell from 7.36 to 6.64 after 28 days. These findings indicate that the cultured human cornea predominantly metabolizes glucose anaerobically, and that the metabolic activity decreases during incubation. The limiting metabolic factors for prolonging the culture period seem to be development of severe acidosis and glucose depletion in the medium.     

Diagnosing dental caries in populations with different levels of dental fluorosis

The aim of this study was to assess the reliability of the Nyvad visual–tactile caries-diagnostic criteria when used among children who have been lifelong residents in areas with 'optimal' or low concentrations of fluoride in the drinking water. In each of two areas with drinking water fluoride concentrations of 0.3 and 1.1 ppm (0.3 and 1.1 mg/l) fluoride, respectively, 150 children were clinically examined twice, 2 wk apart, for dental fluorosis, using the Thylstrup-Fejerskov index (TF index), and for dental caries using the Nyvad visual–tactile caries criteria. The prevalence of dental fluorosis was 45% in the 1.1 ppm fluoride area and 21% in the 0.3 ppm fluoride area. When the results of the duplicate caries recordings were compared at the surface level, only minute differences were observed in the percentage agreement (91.7 and 90.7%, respectively) and in the kappa values (0.73 and 0.72, respectively). When individual DFS counts were compared across examinations using Bland–Altman plots and estimation of prediction intervals for the differences, we observed a greater variability of the differences between recordings among children from the low-fluoride area. Contrary to our expectations, a pronounced dental fluorosis background did not reduce the reliability of the caries recordings, which appeared to be slightly less reliable at very low levels of dental fluorosis.     

Neutrophils and platelets accumulate in the heart, lungs, and kidneys after cardiopulmonary bypass in neonatal pigs

OBJECTIVE: Cardiac surgery with cardiopulmonary bypass elicits a systemic inflammatory response. An exaggerated response is associated with organ dysfunction and increased morbidity and mortality. DESIGN: The aim of the present study was to investigate whether the cardiopulmonary bypass procedure in itself results in accumulation of isotope-labeled platelets, polymorphonuclear neutrophils, and fibrinogen at organ levels in neonatal pigs and to monitor changes in organ function. SETTING: Pediatric cardiopulmonary bypass setup with 60 mins of aortic cross-clamp time and 120 mins of hypothermic cardiopulmonary bypass time. SUBJECTS: Thirty piglets were allocated to sternotomy alone (sham group, n = 15) or to sternotomy and cardiopulmonary bypass (n = 15). MEASUREMENTS AND MAIN RESULTS: Isotope-labeled autologous polymorphonuclear neutrophils, platelets, and commercially available fibrinogen were infused, and the specific accumulation at organ level was measured in a gamma counter 4 hrs after termination of cardiopulmonary bypass. Concomitant changes in oxygenation index and cardiac output were registered. Animals exposed to cardiopulmonary bypass showed a significantly higher technetium-99m-polymorphonuclear neutrophil accumulation in the lungs and kidneys, whereas indium-111-platelets accumulated in the heart and kidneys compared with the sham group. There was a significantly larger increase in oxygenation index and significantly larger decrease in cardiac output between the pre- and postcardiopulmonary bypass period in the cardiopulmonary bypass group compared with the sham group. CONCLUSIONS: The cardiopulmonary bypass procedure without cardiac surgery elicits organ dysfunction in terms of impaired respiratory and hemodynamic function. Platelets and polymorphonuclear neutrophils were entrapped in the heart, lungs, and kidneys of cardiopulmonary bypass animals, indicating that cell accumulation may contribute to the developing organ dysfunction.     

Predictors of psychosis: a 50-year follow-up of the Lundby population

Behavioural and neuropsychological vulnerability have been associated with an increased risk of psychosis. We investigated whether certain clusters of premorbid behavioural and personality-related signs and symptoms were predictors of nonaffective and/or affective psychosis and schizophrenia, respectively, in a 50-year follow-up of an unselected general community population. Total population cohorts from the same catchment area in 1947 (n = 2,503) and 1957 (n = 3,215) that had been rated for behavioural items and enduring symptoms were followed up to 1997 regarding first-incidence of DSM-IV nonaffective and/or affective psychosis. Attrition was 1–6%. The influence of the background factors, aggregated in dichotomous variables (predictors), on time to occurrence of nonaffective and/or affective psychosis was assessed by means of Cox regression models. In multivariate models the predictors nervous-tense, blunt-deteriorated, paranoid-schizotypal and tired-distracted were significantly associated with subsequent nonaffective and/or affective psychosis. In simple models, down-semidepressed, sensitive-frail and easily hurt were significantly associated with development of psychosis. When schizophrenia was analysed separately nervous-tense remained significant in the multivariate model, although blunt-deteriorated, paranoid-schizotypal and tired-distracted did not; and abnormal-antisocial reached significance. To conclude, we found some evidence for anxiety-proneness, affective/cognitive blunting, poor concentration, personality cluster-A like traits and interpersonal sensitivity to be associated with general psychosis vulnerability.