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Biomedical subjects

R Johnson

Publications and source records attributed to R Johnson.

At least 469 records · Page 26Linked to original sources

Intestinal atresia and stenosis: a review comparing its morphology.

A review of the literature on intestinal atresia of domestic animal species and humans was done. The 5 types of intestinal occlusions described in human infants are atresia type 1, atresia type 2, atresia type 3, stenosis, and the "apple peel" or "Christmas tree" deformity. The intestinal defects described in domestic animal species such as the bovine, equine and porcine are similar to those of human infants. The "T-formation", an intestinal defect of the bovine resembling atresia type 3, and rectal stricture, an acquired intestinal defect of the porcine resembling stenosis, were described recently. Intestinal atresia is similar in several species and these similarities raise the questions as to whether the pathogenic mechanism and possibly etiologies of intestinal atresia are similar in these species.

Animals↗

The group selection of variola minor in the Americas: an anthroponootic analogue for the myxomatosis epizootic in Australia.

It is an axiom of many parasitology texts that host-parasite systems coevolve toward a state approximating commensalism. While this hypothesis has an apriori intuitive appeal there is little empirical evidence to support it. The only documented case of a parasite evolving toward avirulence is the group selection of less virulent strains of the myxoma virus in the Australian rabbit population. It is hypothesized here that group selection also accounted for the appearance of variola minor in the Americas.

Americas↗

Isolated teenagers, cooperative learning, and the training of social skills.

The effects of individual and group contingencies on the achievement and social integration of isolated, learning-disabled students were studied. Five socially isolated and withdrawn eighth-grade students in foreign-language and math classes were subjects. The choice of working alone or in a group with no academic contingency (i.e., bonus points) was compared with working in cooperative learning groups with a group-academic contingency (i.e., bonus points), a group-academic contingency with social-skills training, and a group-academic contingency in combination with a social-skills contingency (i.e., bonus points). The results indicated that the combination of group-academic and social-skills contingencies produced in the socially isolated and withdrawn students the highest rates of appropriate social interaction with peers, acceptance and liking by peers, positive attitudes toward the subject area, and achievement.

Achievement↗

Physically ill and mentally ill.

Undetected physical illnesses in psychiatric patients are common. Why do so many physical illnesses go undetected? These disorders are difficult to detect and need an elaborate consultatory process. Some of the problems may be related to the fact that psychiatrists do not do physical examinations. Clues suggesting an organic etiology may be attributed to psychodynamic issues by many physicians. In this paper, seven case reports are presented to illustrate the following: perform your own physical examination; do not attribute physical signs to dynamic issues; all physical signs should be explained; be alert to atypical presentations; conduct relevant laboratory workup; avoid bias against unattractive patients; and pose specific questions to consultants.

Attitude of Health Personnel↗

Central auditory processing and attention deficit disorders.

Nineteen children who met criteria for attention deficit disorder (ADD) received neurodevelopmental attention testing and central auditory processing (CAP) tests. The CAP tests consisted of the Staggered Spondaic Word (SSW) test and the Willeford battery of tests. Teacher and parent questionnaires (originally devised at the Learning Disabilities Clinic, The Children's Hospital, Boston) were obtained. There was a very high concordance between the questionnaires and the CAP tests, but a low concordance between the neurodevelopmental measures and the questionnaires. After treatment with central nervous system stimulants, there was again a high concordance between teacher/parent reports and CAP measures, and less than 50% concordance between neurodevelopmental measures and teacher/parent observations. We conclude that the SSW and Willeford battery are sensitive performance indicators of attention disorder. Furthermore, these tests are more useful in titrating response to CNS stimulants than neurodevelopmental assessments and provide objective support for the subjective teacher and parent observations.

Adolescent↗

Comparison of mannitol regimens in patients with severe head injury undergoing intracranial monitoring.

Eighty patients sustaining head injuries and presenting with Glasgow Coma Scale scores of 8 or less were entered into a prospective randomized study to assess the benefit of intracranial pressure (ICP) monitoring with two regimens of mannitol administration. Group I was treated with mannitol for ICP elevations greater than 25 mm Hg, while Group II received empirical mannitol therapy irrespective of ICP readings. No statistically significant differences in mortality rate or neurological outcome were demonstrated between the two groups. These results are comparable to those of several published series of head-injured patients receiving similar treatment from 1977 to 1982. However, those series must be reassessed in light of recently published studies with treatment initiated at lower levels of ICP.

Adolescent↗

Quality assessment of determinations of serum fructosamine in 33 clinical chemistry laboratories.

We investigated the analytical performance of fructosamine measurement in 33 routine clinical chemistry laboratories. We prepared 12 human control sera spanning a range of nondiabetic and diabetic fructosamine concentrations and assigned target values by using commercial reagents and a Cobas Bio centrifugal analyzer. Each control serum was analyzed by participating laboratories on two separate occasions. Averaged results were compared with target values, and systematic error was determined from slope and intercept regression coefficients. Overall, we found no significant (p greater than 0.05) slope or intercept bias, although slight nonlinearity was found with bichromatic instruments. Random error was determined from the standard error of estimate and from duplicate measurements. We found a median interlaboratory CV of 5.36% and similar analytical performance with all automated instruments used. The median random error with manual techniques was 18.1%. We conclude that fructosamine measurement as currently performed in routine laboratories is sufficiently accurate and reliable to function as an index of blood glucose control in diabetic patients.

Blood Glucose↗