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Biomedical subjects

G Silverman

Publications and source records attributed to G Silverman.

At least 19 recordsLinked to original sources
PubMed1990

Effects on students of teacher training in use of a drug education curriculum.

The study reported here examines the effects of differential teacher training in use of a drug education curriculum on students' knowledge levels, problem-solving and coping skills, attitudes towards planned decision making, behavioral intentions and tobacco and alcohol use. An experimental design was used to compare the effects of exposure to teachers who had either intensive staff development, in-service training or no training. The findings indicate a statistically significant difference between groups of students on the intention to drink alcohol. Students whose teachers had intensive staff development were less likely to intend to take a drink if offered than students whose teachers had in-service or no training. Possible reasons for a lack of significant results on other variables are the confounding influences of school, classroom and teacher effects.

Adolescent↗
PubMed1987

Rheumatoid factor and immune networks.

Rheumatoid factors represent a normal component of the immune network. The autoantibodies promote complement fixation and clearance of immune complexes. They amplify the avidity of polyclonally induced IgG. Genes related to the primary structure of rheumatoid-factor light chains are widely distributed in the human population and have been conserved during the evolution and dispersion of the species. Products of these genes may be detected with anti-idiotypic antibodies against synthetic peptides corresponding to individual hypervariable regions on rheumatoid-factor light chains. Such anti-peptide antibodies provide unique reagents for analyzing the genetics of immunoglobulins in outbred populations. Precursors of rheumatoid factor are abundant among immature B lymphocytes. Some of these cells may tend to localize to mucosal surfaces, where they are stimulated directly by pathogenic microorganisms with polyclonal B cell-activating properties. Synthesis of rheumatoid factor regularly accompanies all secondary immune responses but is usually transient. Production of the autoantibody is T-cell dependent. The T cells may recognize antigen in an IgG-antigen immune complex that is processed and presented by B-cell precursors of rheumatoid factor. Rheumatoid factor-associated light-chain idiotypes are rare in serum IgG and on IgG myeloma proteins. They are common among monoclonal IgM proteins and on the surface of the malignant B cells from patients with chronic lymphatic leukemia. The rheumatoid factors that are produced by patients with mixed cryoglobulinemia, or primary Sjogren's syndrome can share idiotypic antigens with monoclonal rheumatoid factors. Rheumatoid factor synthesis in the diseases may reflect an abnormal proliferation of B-cells that is not antigen-driven and that can degenerate into malignancy. The rheumatoid factors in patients with rheumatoid arthritis are diverse and almost certainly represent the outcome of antigen-induced, T cell-dependent mechanisms. The antigens that drive the T cells have not been identified but could represent exogenous microorganisms, self components, or idiotypic antigens that fortuitously interact with rheumatoid factors.

Autoantibodies↗
PubMed1984

Computer based instruments for laboratory environments.

The personal computer is viewed as an all-purpose laboratory instrument and work station. Popular architectures are examined with regard to advantages and limitations, and applications discussed in terms of "stand alone" environments, situations requiring passive interfaces, and those employing intelligent configurations. A new hardware/software architecture is presented which is highly modular, and which supports rapid instrumental reconfiguration, high throughput (information capacity), and ease of use.

Computers↗
PubMed1984

Binocular summation on fused annular backgrounds.

A paradigm has been proposed to test the hypothesis that binocular fusion results in simple summation, S, of monocular photopic luminances: S = delta LBM(L)/delta LB(2L) = 1, where delta LBM and delta LB are threshold luminances for a monocular and a binocular increment, appearing on a fused background of luminance L or 2L, respectively. This prediction was tested psychophysically, with background size as parameter. Thresholds were measured for a brief (20 ms) foveal flash centered on a luminous disk encircled by a massive black annulus serving as a fusion lock. The flash was presented binocularly, or monocularly, at 30 and 60 cd m-2 background luminances. The diameter of the disk was varied from 3 min to 40 min visual angle. The size of the flash was constant (6 min diameter), except for the smallest disk (3 min diameter). All thresholds varied as a function of background size (the known 'sensitization effect'). The summation index S did not vary with background size. A mean value S = 0.9 was found; this is consistent with the notion that summation of the order of 90% occurs during binocular fusion. We surmise that even a weak monocular test flash makes fusion less than perfect.

Adult↗
PubMed1981

A teachers' guide to teaching medical interviewing.

Success in teaching a course in medical interviewing requires competence on the part of instructors, who also need training, and have to provide a structured approach. Problems encountered by course coordinators at the Department of Family Medicine, University of Miami School of Medicine, Miami, Florida have been: (1) a shortage of skilled teachers; (2) inadequate motivation of instructors for teaching the course; (3) differences in content, teacher's style, and outcomes from small groups; and (4) ambiguities in structure or guidelines provided for teachers. The development of a teacher's guide, giving specific objectives and step-by-step methods for teaching significantly improved teacher satisfaction and commitment to the course, as well as student learning.

Education, Medical, Undergraduate↗
PubMed1980

Clinical evaluation of a new treatment for dentinal hypersensitivity.

The effectiveness of potassium nitrate (5%, delivered in a low abrasive toothpaste vehicle) as a daily home treatment of dentinal hypersensitivity was evaluated in a 4-week, double-blind, parallel, comparative study of 27 subjects with the condition. Hypersensitivity levels in affected teeth were assessed by two quantifying methods--electrical stimulus and cold air stimulus--and by a subjective recall procedure. The results from these three methods of assessment indicate that potassium nitrate desensitizes hypersensitive teeth to a significant degree. The therapeutic response (decline in dentinal hypersensitivity) to potassium nitrate was evident within 1 week and increased continuously for the length of the study period. Sensitivity threshold of teeth adjudged to be normally sensitive were not altered by treatment with potassium nitrate, nor did the agent exert any discernable effects on oral tissues.

Adolescent↗
PubMed1979

An evaluation of two methods for the quantitation of dentinal hypersensitivity.

In a well-controlled, double-blind, parallel study design using burnishing with 33% sodium fluoride paste and "sham" burnishing with a placebo paste, both a cold air stimulus method and an electrical stimulus method can discriminate between levels of dentinal hypersensitivity. Correlation between the scores obtained by the methods was significant. The electrical stimulus method discriminated between the sodium fluoride and placebo effects to a greater degree than did the cold air method. Use of these methods should broaden the scientific foundation and rationale for evaluating the condition of dentinal hypersensitivity and the agents designed for treatment of persons with this condition.

Adult↗