Randomized controlled trial of supported discharge in patients with exacerbations of chronic obstructive pulmonary disease.

BACKGROUND: A randomised trial was performed on patients presenting to hospital with an exacerbation of chronic obstructive pulmonary disease (COPD) to compare outcomes in those managed at home with support with those admitted to hospital in the standard manner. METHODS: Over an 18 month period all patients presenting to the Royal Infirmary of Edinburgh on weekdays (n=718) with a diagnosis of an exacerbation of COPD were assessed for inclusion in the trial. Patients with impaired level of consciousness, acute confusion, acute changes on radiography, or an arterial pH of <7.35 or with other serious medical or social reasons for admission were excluded. Patients randomised to home support were discharged with an appropriate treatment package (antibiotics, corticosteroids, nebulised bronchodilators and, if necessary, home oxygen). They were visited by a nurse the following day and thereafter at intervals of 2-3 days until recovery when they were discharged from follow up. Parallel observations were made on patients allocated to normal hospital admission up to the point of discharge. Patients in both groups were assessed at home eight weeks after the initial assessment. RESULTS: Among weekday patients 353 (50%) were considered obligatory admissions, 140 (19%) were admitted because of co-morbidity, 17 (2%) because of poor social circumstances, and 24 (3%) did not consent to the trial. The remaining 184 (26%) were randomised (2:1) either to home support or to a standard hospital admission. The median time to discharge was 7 days for the home support group and 5 days for the admitted group (p<0.01); 25% of the home support group and 34% of the admitted group were readmitted before the final assessment at eight weeks (p>0.05). There were no significant differences between the groups in attendances by GPs and carers or in health status measured eight weeks after the initial assessment. Satisfaction with the service was good. The mean total health service cost per patient was estimated as 877 pounds sterling for the home support group and 1753 pounds sterling for the admitted group. CONCLUSIONS: This study shows that home supported discharge is a well tolerated, safe, and economic alternative to hospital admission for a proportion of patients referred to hospital for admission for an exacerbation of COPD.

Cultivation of an L-lactate dehydrogenase mutant of Bacillus stearothermophilus in continuous culture with cell recycle.

Continuous fermentation with cell recycle proved very effective in increasing the ethanol volumetric productivity of the thermophilic facultative anaerobe, Bacillus stearothermophilus strain LLD-15, on sucrose at 70 degrees C. When complete cell recycle was used, cell viability decreased after a few residence times and sucrose consumption was reduced. Operation using a constant bleed rate resulted in greater stability and higher ethanol volumetric productivities. A mathematical model based on maintenance energy requirements provided an adequate description of the system.

von Willebrand factor, the endothelium and obesity.

von Willebrand factor (vWf), risk factors for atherosclerosis, body mass index (BMI) and waist-to-hip ratio (WHR) were measured in 108 non-diabetic patients attending lipid and vascular disease clinics and in 107 normal asymptomatic controls. High levels of vWf and increased BMI relative to controls were found in patients with hyperlipidaemia and vascular disease, but WHR was higher only in patients with vascular disease. Total serum cholesterol concentration (P < 0.001), systolic blood pressure (P < 0.001), smoking (P < 0.02) and BMI (P < 0.001), but not WHR, were associated with vWf. As raised levels of vWf are a probable indicator of endothelial damage in vascular disease, these data suggest that obesity has an adverse influence on the endothelium and may help explain its link with cardiovascular disease.

Development of a synthetic medium for continuous anaerobic growth and ethanol production with a lactate dehydrogenase mutant of Bacillus stearothermophilus.

A synthetic medium was developed by the pulse and medium-shift technique for the continuous cultivation of Bacillus stearothermophilus strain LLD-15 (NCIMB 12428) under anaerobic conditions. This mutant strain lacks L-lactate dehydrogenase activity, and is a promising candidate for the production of ethanol from pentoses and hexoses, using a high-temperature two-stage process. The final medium contained four amino acids and five vitamins, and growth characteristics in this medium compared well with those in complex medium containing yeast extract and tryptone. At 70 degrees C, the medium was capable of supporting good anaerobic and aerobic growth at 10 g input sucrose l-1. High ethanol production indicated that pyruvate metabolism probably occurred via the combined activity of the pyruvate-formate-lyase pathway and pyruvate dehydrogenase.

The circadian rhythm of the N-terminus and C-terminus of the atrial natriuretic factor prohormone.

Circadian variation in the circulating concentrations of the N-terminal and C-terminal portions of the atrial natriuretic factor prohormone (pro ANF) was evaluated in 8 men, ages 41-47, who have been followed for 19 years with respect to circadian variation in physiological variables including blood pressure and clinical chemistries. The N-terminus of the ANF prohormone contains two peptides consisting of amino acids 1-30 and 31-67 while the C-terminus contains 1 peptide (amino acids 99-126) of this 126 amino acid prohormone which lower blood pressure and have natriuretic properties. To determine if either the N-terminus and/or the C-terminus of the prohormone have a circadian variation in their circulating plasma concentrations these 8 men had blood samples obtained for radiommunoassay every 3 hr during a 24-hr period. Three radiommunoassays which immunologically recognize (1) the whole N-terminus (i.e. amino acids 1-98), (2) the midportion of the N-terminus (amino acids 31-67) and (3) the C-terminus (amino acids 99-126) of the ANF prohormone were utilized. The whole N-terminus, the midportion of the N-terminus which circulates after being proteolytically cleaved from the rest of the N-terminus, and the C-terminus each had a peak circulating concentration between 0400 and 0700 which were significantly (P less than 0.001) higher than their concentrations at any other time throughout the 24-hr period.(ABSTRACT TRUNCATED AT 250 WORDS)

Two types of feedback in teaching swimming skills to handicapped children.

Two types of feedback (non-task-specific praise and task-specific praise plus corrections) were used in a counterbalanced design to teach two swimming skills to each of four handicapped children. The children were grouped into pairs, and each member of a pair received the alternate type of feedback for the same skill. In every case, faster and more complete acquisition was found to result from task-specific praise plus corrections.

The length of teacher contacts and students' off-task behavior.

This study investigated the relationship between a teacher's contact durations and the off-task behavior of students not in contact with the teacher. Contact durations were defined as the amount of time the teacher spent working individually with each student. Off-task behavior was recorded for six third-graders who comprised a small instructional group in mathematics. After baseline established that contact durations averaged approximately 38 sec, the teacher was instructed to hold contacts for at least 50 sec. During this phase, the students' off-task behavior increased. The teacher was then instructed to hold contacts for only 20 sec. During this phase, the students' off-task behavior decreased.

The use of programmed materials in the analysis of academic contingencies.

Programmed handwriting materials were used to examine the effects of different reinforcement contingencies on the academic performance of six public school kindergarten children. The children's responses to these materials provided an educationally relevant dependent variable for the analysis of factors that affected the accuracy of their responses and the attainment of criterion performances. Variations in the complexity of most academic materials, which confound the analysis of contingencies, were eliminated by the programmed sequence so that the differential effects of three reinforcement conditions were observed. The three conditions were: baseline without tokens, tokens contingent on correct writing responses, and noncontingent tokens. It was consistently observed that the children were more accurate when their correct responses produced tokens, and that noncontingent tokens reduced accuracy below baseline levels.

The effects of token procedures on a teacher's social contacts with her students.

The effects of a token system on a teacher's rate of social contacts with her students were investigated in a public school kindergarten. A group of six children were observed daily during a 20-min handwriting lesson. The children were divided into two groups (A and B) of three children each. Five conditions were imposed sequentially: (1) baseline without tokens, (2) contingent tokens for Group A, noncontingent tokens for Group B, (3) contingent tokens for Group B, noncontingent tokens for Group A, (4) reinstatement of condition 2, and (5) contingent tokens for both groups. It was consistently observed that the teacher's rate of social contact was higher with the children receiving the contingent tokens than with those who received noncontingent tokens.

Switching requirements in a Head Start classroom.

Two experiments were conducted by the mothers of the children in a Head Start classroom. Both examined the effects of a switching task on the frequency with which children moved from one activity area of the classroom to another. The results indicated that the rate at which the children changed activities could be adjusted by varying the difficulty or magnitude of the switching task and that the task itself could be used to introduce academic subjects which would be poorly attended if initially presented in an activity area.

Applying "group" contingencies to the classroom study behavior of preschool children.

A group of 12 children were enrolled in a preschool class. During the first experimental stage they participated in special events contingent on token earning. Tokens were acquired by engaging in a variety of study behaviors. After a level of study behavior was established under this contingency, the special events were provided noncontingently. Study behavior declined throughout the noncontingent stage. Reestablishing the original contingencies produced an immediate return to the initial level of study behavior. Noncontingent special events reduced the amount of independent study, group participation, and cooperative study. The study behavior of each child was altered in the same direction, though differences in the magnitude of effects from child to child were observed.