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Biomedical subjects

M Hoffman

Publications and source records attributed to M Hoffman.

At least 379 records · Page 21Linked to original sources
PubMed1979

Cognitive modifiability in retarded adolescents: effects of instrumental enrichment.

The Instrumental Enrichment program, designed to modify the cognitive structures of retarded, disadvantaged adolescents, was contrasted with a General Enrichment program both in a residential setting and a day center. This study is based on 57 matched pairs drawn from the total research sample of 218 adolescents. One group in a residential center (n = 24) and one group in a day center (n = 33) received Instrumental Enrichment; one group in a residential center (n = 24) and one group in a day center (n = 33) received General Enrichment. The Instrumental Enrichment program extended over 2 years, and the subjects were pre- and posttested on a battery of criterion measures: general and specific cognitive tests, scholastic achievement, classroom interaction, and self-concept. The results indicated significantly better performance by the groups receiving Instrumental Enrichment than by the groups receiving General Enrichment on the tests of specific cognitive functions and scholastic achievement and on some of the classroom interaction scales. Results for the residential groups compared with the day-center groups revealed significant differences on the tests of scholastic achievement, in favor of the residential groups and on the classroom interaction scales in favor of the day-center groups.

Achievement↗
PubMed1978

Analysis of antibody assay methods and classes of viral antibodies in serodiagnosis of cytomegalovirus infection.

Forty-nine serum pairs with antibody to cytomegalovirus (CMV) were evaluated for rises in antibody titer (greater than or equal to fourfold) by indirect hemagglutination (IHA) and complement fixation (CF), using a freeze-thaw antigen (FT) and a glycine extract antigen (GE). In this sample CF-FT detected more rises in antibody titer than did CF-GE. IHA detected the least number. The apparent reason for stationary antibody titers with CF-GE and IHA was the presence of high antibody titers in the first serum specimen. Separation of immunoglobulin classes of 20 serum pairs by sucrose gradient centrifugation indicated that these antibodies with IHA were of the immunoglobulin M (IgM) class and those with CF-GE were of the IgG class. By separation of immunoglobulin classes, rises in IgG CMV antibody titers were seen with IHA, rises not observed in the whole serum because of high IgM antibody titers in the first serum specimen. Absence of rises in antibody titers with CF-FT was due in part to too early sampling of the second serum specimen (less than 21 days) and in part to an apparent inability of some individuals to respond with antibody reactive with FT antigen. CF-GE and CF-FT antibodies of the IgM class were detected in some sera, usually in specimens collected more than 10 days after the onset of symptoms. Although reactive with CMV antigen, the specificity of these IgM antibodies in relation to rheumatoid factor requires clarification.

Adult↗
PubMed1978

Role of rheumatoid factor in complement fixation and indirect hemagglutination tests for immunoglobulin M antibody to cytomegalovirus.

Absorption of immunoglobulin M (IgM)-rheumatoid factor (RF) from serum samples by reaction with insolubilized gamma globulin reduced the complement-fixing (CF) antibody titer to cytomegalovirus (CMV) antigen to less than 1:2 in the IgM fraction of some, but not all, sera. Thus, IgM-CF activity in some sera appeared to be due to specific IgM anti-CMV antibody and in other sera to complexes of IgM-RF with antiviral IgG antibody. Prozones were present in the CF tests on IgM fractions. Increasing the concentration of antigen from 2 to 4 U reduced the prozone titer by one or two double dilutions. This observation suggested that a competition for antigen may be operating at low dilutions of IgM antibody fractions. Removal of RF had little or no effect on the reaction of the IgM fraction of sera with CMV by the indirect hemagglutination test.

Absorption↗
PubMed1978

Philosophical aspects of "mental disease".

It is shown that the label "mental disease" derives from value judgements made by the labeller, and that science alone cannot determine the ultimate validity of these judgements. Hence, the term must be, in a genuine sense, based on social and moral convention. However, it is argued that this does not necessarily mean that the medical model, as contended by Szasz and his school, has no value. Rather, it is claimed here that only by returning to the medical model can we make best use of our psychiatric knowledge and best serve our patients.

China↗
PubMed1975

Complement-fixing antibody in human sera reactive with viral and soluble antigens of cytomegalovirus.

Antibody titers to cytomegalovirus were determined in 204 single-serum specimens and in 138 serum pairs, utilizing as antigen extracts of infected cells prepared by either freezing and thawing cells (FT antigen) or extracting them with a glycine buffer (GE antigen). With the serum pairs, 40% of the early sera and 44% of the late sera showed a fourfold or higher antibody titer with the GE antigen compared with those with the FT antigen, whereas 39% of the single sera had a fourfold or higher titer with the GE antigen. Sucrose density gradient centrifugation of the two antigen preparations indicated that the GE antigen contained two peaks of complement-fixing activity, one at a density of 1.18 to 1.22 g/cm3 and one at 1.06 to 1.10 g/cm3. The FT antigen had only one discernible peak of complement-fixing activity at 1.04 to 1.10 g/cm3. On electron microscopy, the more dense peak contained mainly nucleocapsids with some dense bodies and occasional enveloped virions, and the lighter peak was composed of amorphous material. Antibody titers obtained with the crude GE antigen and the more dense peak (designated viral antigen) were in agreement, whereas titers with the FT antigen agreed with those obtained with the lighter peak (soluble antigen). The antibody detected with both antigens was mainly immunoglobulin G.

Antibodies, Viral↗