The effect of media composition on the thermal resistance of Bacillus stearothermophilus

Spores of Bacillus stearothermophilus ATCC 7953 were developed at 62 degrees C on 32 media composed of various amounts of 11 components: D-glucose, L-glutamic acid, yeast extract, peptone, sodium chloride, magnesium sulfate, ammonium phosphate, potassium phosphate, calcium chloride, ferrous sulfate and manganese sulfate. Statistical models were used and demonstrated a strong interaction of yeast/peptone/ammonium phosphate, contributing positively to the best sporulation yield (6-7 log10 spores). The most influential medium components on the thermal resistance (at 121 degrees C) of spores in suspension (calcium acetate, pH 9.7) were yeast extract (positively) and potassium phosphate (negatively), both creating the positive interaction, for spores from a 6-day incubation period. However, the strong negative effect of sodium chloride decreased the D-value from 1.81 min to 0.57 min upon increasing the incubation period (62 degrees C) from 3 days to 6 days. The D-glucose and peptone exhibited greater effects than the yeast extract and potassium phosphate interaction on D-values for 3-day spores on strip, just as the highly joint-positive peptone/sodium chloride effect maintained the thermal resistance of 6-day spores on strips. The spores on strip system showed less stability than the spores in suspension. The most stable spore system confirmed D-values at 121 degrees C at a range between 1.5 min and 1.9 min, which were obtained by keeping sodium chloride and potassium phosphate at minimum concentrations and yeast extract and peptone at maximum concentrations, regardless of the 3- to 6-day sporulation.     

Coeliac disease in identical twins.

Coeliac disease occurred at the same age in MZ twins. The diagnosis was confirmed by histology of the small intestine, rapid response to a gluten-free diet, and relapse after reintroduction of gluten.     

Effect of a Practice Guideline for Emergency Department Care of Falls in Elder Patients on Subsequent Falls and Hospitalizations for Injuries

OBJECTIVE: To determine the effect of a practice guideline for the ED management of falls in community-dwelling elders on selected health outcomes. METHODS: The experimental design was a prepost-intervention comparison with one-year pre- and post-intervention phases. The guideline was presented to emergency physicians and nurses during a two-week interval between these two periods. The intervention also included health information provided to the subjects and a one-time educational intervention directed at primary care providers. The number of falls in the year following the ED visit was determined by telephone interview. The number of hospitalizations for falls was determined from the HMO database of all health care encounters. RESULTS: 1,899 patients were eligible for the study; 1,140 pre-intervention and 759 post-intervention patients. Of these, 1,504 (79%) were interviewed by telephone 12 to 15 months after their initial ED visits. Eighteen percent of the pre-intervention and 21% of the post-intervention subjects reported at least one fall in the 12 months following their ED visits (p = 0.162). The rate of falls per 100 patient years was 36.2 in both groups. Three percent of both groups were hospitalized at least once for a fall in the year following their ED visits. One percent in each group were hospitalized for a hip fracture. CONCLUSIONS: The attempted implementation of a practice guideline for the ED management of falls in community-dwelling elders did not result in a reduction in total falls, or in hospitalizations for falls, injuries, or fractures.     

Simulating prosopagnosia through a lesion of lateral connections in a feed-forward neural network

We show that particular features of prosopagnosic impairment can be simulated by a connectionist model trained with an unsupervised learning procedure. In particular we describe a Kohonen's neural network which is able to correctly recognize and categorize a series of digitized pictures of faces when learning is characterized by certain parameter values, but which shows a prosopagnosic behavior when lateral connections are lesioned. We discuss the relationship between this result and some neurophysiological hypotheses about prosopagnosia.     

Assessment of peri-neonatal mortality and morbidity risk in twin pregnancy

A case control study on peri-neonatal mortality and morbidity rates in 154 twin pregnancies has been performed. The mortality rates along with main neonatal morbidity factors were evaluated in relation to the birth weight and gestational age. The risk of death in peri-neonatal period was 17 times greater (relative risk 17.30) (p less than .00005) in newborns weighing less than 2000 g and about 15 times (r.r. 14.53) (p less than .00005) in twins born before 34th week of gestational age with respect to the controls. The Apgar score of the 2nd twin was lower than that of the 1st, both at 1' (p less than .05) and 5' (p less than .025). The development of HMD was strongly influenced by the gestational age when less than 34th week (r.r. 15.89) (p less than .00005). No difference in incidence was found between the newborns with gestational age between 34-37 weeks and those at term. The potential implications of these findings on obstetric and neonatologic treatment of LBW and VLBW twins was discussed.     

Modulation of alpha-adrenergic-induced contractions by endothelium-derived relaxing factor in rat aorta.

1. In rat thoracic aorta, endothelium removal produced a significant increase of the maximal contraction (Emax) and of the pD2 value (-log ED50) induced by norepinephrine, phenylephrine and clonidine, and did not affect the maximal contractile response to 70 mM KCl. 2. Clonidine did not induce a contraction in aorta with intact endothelium, but after endothelium removal, the contractile response was 94.8% of the Emax produced by norepinephrine in aorta with endothelium. 3. Pre-incubation with methylene blue (10(-5) M) and hemoglobin (0.02%), which inhibit EDRF effects, produced the same effects as the mechanical removal of endothelium on the contractile responses to alpha-adrenergic agonists. 4. These results suggest that EDRF formation and release is an important factor in the modulation of alpha-adrenergic-induced vasoconstriction.     

A low-cost approach to prospective identification of impending high cost outcomes.

OBJECTIVES: The overall objective of this study was to define and evaluate patterns of use of medical services in the care of patients with chronic illness that represent circumstances which, if modified, might lead to reduction in risk of acute-level care. METHODS: This was a retrospective observational study. The study population consisted of Kaiser Permanente enrollees at four sites during January 1993 through June 1995, who were 20 to 64 years of age and had two of three chronic diseases (diabetes, circulatory disorders, obstructive pulmonary disorders). Using logistic regression, the effect of primary care visit patterns and therapeutically risky drug combinations on likelihood of hospital admission in a subsequent 3-month period is adjusted for age, gender, and disease state in the prior 12-month period. RESULTS: Enrollees with visits to three or more different primary care physicians were 46% more likely to be admitted than expected (P < 0.01) according to their age, gender, and disease state, and those with therapeutically risky drug combinations were 34% more likely to be admitted (P < 0.01). CONCLUSIONS: The risk adjustment models evaluated in this study defined care processes associated with increased risk of subsequent acute-level services. Those processes may represent nascent acute disease states or suboptimal organization of care delivery. The results of these models can be used to inform changes in organization and delivery of outpatient care that might improve patient outcomes.     

Spatial Distribution of Leprosy in the Amazon Region of Brazil

To detect areas with increased case-detection rates, we used spatial scan statistics to identify 5 of 10 clusters of leprosy in the Amazon region of Brazil. Despite increasing economic development, population growth, and road infrastructure, leprosy is endemic to this region, which is a source of case exportation to other parts of Brazil.