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Biomedical subjects

R Stark

Publications and source records attributed to R Stark.

At least 91 records · Page 5Linked to original sources
PubMed1982

Decreased actin content of lymphocytes from patients with chronic lymphocytic leukemia.

Actin, a major cytoskeletal protein, was quantitated in normal and chronic lymphocytic leukemia lymphocytes. The actin content of normal human blood lymphocytes was 2.2 +/- 0.4 mg/10(9) cells and represented 6.6% +/- 1.8% of the total cellular protein. A significant decrease (p less than 0.001) was noted in chronic lymphocytic leukemia lymphocytes that contained 1.4 +/- 0.3 mg actin/10(9) cells, constituting 4.3% +/- 1.1% of the total protein. Normal T and B cells did not differ in actin content. Reduced actin levels were found in the T as well as in the B lymphocytes of "B-cell" chronic lymphocytic leukemia. The possible importance of the decreased actin level in the anomalous capping response and motility of chronic lymphocytic leukemia lymphocytes is discussed.

Actins↗
PubMed1981

A reexamination of some nonverbal perceptual abilities of language-impaired and normal children as a function of age and sensory modality.

A battery of nonverbal perceptual and memory tests were given to 35 language-impaired (LI) and 38 control subjects. Three modalities of tests were given: auditory, visual, and cross-modal (auditory and visual). The purpose was to reexamine some nonverbal perceptual and memory abilities of LI children as a function of age and modality of stimulation. Results failed to replicate previous findings of a temporal processing deficit that is specific to the auditory modality in LI children. The LI group made significantly more errors than did controls regardless of modality of stimulation when 2-item sequences were presented rapidly, or when more than two stimuli were presented in series. However, further analyses resolved this apparent conflict between the present and earlier studies by demonstrating that age is an important variable underlying modality specificity of perceptual performance in LI children. Whereas younger LI children were equally impaired when responding to stimuli presented rapidly to the auditory and visual modality, older LI subjects made nearly twice as many errors responding to rapidly presented auditory rather than visual stimuli. This developmental difference did not occur for the control group.

Aging↗
PubMed1979

Comparison of enteric-coated levodopa with levodopa-carbidopa combination. A double-blind crossover trial.

Twenty-seven patients with idiopathic Parkinson's disease completed a double-blind crossover trial which compared enteric-coated levodopa (Prodopa) with levodopa-carbidopa combination (Sinemet). It was easy to stabilize the patients' condition with either drug, and the dose-sparing effect both of the enteric-coated preparation, and of the levodopa-carbidopa combination was again noted. At the dosages used, the levodopa-carbidopa combination was objectively shown to be more effective in 71% of the patients investigated, although there was no clear personal preference for either preparation when patients compared the two parts of the trial. Both drugs play a valuable role in the treatment of Parkinson's disease.

Adult↗
PubMed1979

Detection and partial characterization of a new murine T-lineage antigen: evidence for its enzymatic modulation.

A molecule with an apparent molecular weight of 21,000 daltons was found to be a predominating differentiation antigen of peripheral rat T lymphocytes. This antigen is also expressed on the cell surface of thymus lymphocytes though partially in masked form. The observation that these determinants could be unmasked by neuraminidase treatment in vitro suggests that enzymatic processes may play an important role in antigenic transformation along the differentiation pathway of T axis lymphocytes. Since this structure was found to be displayed also by peritoneal exudate macrophages, it is referred to as T lymphocyte-macrophage antigen. The finding that an identical antigen could be identified in the mouse suggests its more common biological significance.

Animals↗
PubMed1978

Bromocriptine in lieu of levodopa for Parkinson's disease.

Thirteen patients with Parkinson's disease, whose disability was increasing and on long-term levodopa therapy (both with and without carbidopa), had the levodopa fully replaced by bromocriptine. At three months, eight of the 13 patients (62%) were less disabled on bromocriptine and none became worse. The present indications for the use of bromocriptine are discussed.

Adult↗
PubMed1978

Sixth graders can take blood pressures.

A curriculum guide entitled "Heart Health Curriculum Guide" was developed with and by teachers in Peabody Public Schools under a Massachusetts Public Health grant to the American Heart Association. The 67-page manual describes the format of the 12-hour teacher workshop, background physiology of heart/circulatory system, hypertension risk factors, a set of 20 lessons, and evaluating procedures. (Copies may be obtained for $3.00 by writing the corresponding author.) As a result of teaching this unit, sixth grade students in each school ran a Blood Pressure Screening Clinic for their parents and school staff.

Blood Pressure Determination↗
PubMed1978

Serological and chromatographic analyses of antigenic structures detected in human brain, thymus and lymph nodes.

In the present paper it is shown that the non-species specific determinant of the antigenic thymus-brain system previously detected in murine and human brain also exists in human thymus. However, in contrast to the situation in mice and rats this antigenic structure is not expressed on suspended thymic lymphocytes, but is associated with thymic tissue largely depleted of thymic lymphocytes. Moreover, this determinant is also detectable in human lymph nodes. Besides the non-species-specific antigenic determinant human thymus and brain also share a species-specific determinant. In contrast to the non species specific determinant this structure is also displayed by suspended thymic lymphocytes, certain peripheral blood lymphocytes and bone marrow cells. The non-species-specific determinant detected in human thymus is borne by a structure, which physico-chemically resembles the thymus-brain antigen isolated from murine brain and thymus as well as from human brain. Although the structure bearing the species specific antigenic determinant has a similar apparent molecular weight both antigens could be separated by ion exchange chromotography indicating their molecular diversity.

Animals↗
PubMed1977

Analysis of the antigenic structure of the thymocyte surface membrane by heterologous anti-thymocyte serum.

The surface membrane of rat thymocytes and lymph node cells was analyzed by comparing the capability of different rat cell types and of solubilized and chromatographically separated rat thymocyte membrane fractions to absorb cytotoxic antibodies on rat thymocytes and lymph node cells from a heterologous anti-rat thymocyte serum. The experiments described cause distinct antigenic specificities of the thymocyte membrane to be brought into relationship to structures of defined physio-chemical properties, and thus are an approach of a thymocyte cell surface mapping in antigenic as well as in molecular terms. Futhermore, the data presented allow conclusions on the distribution pattern of single antigenic determinants on different cells or tissues used as absorbents and target cells.

Animals↗
PubMed1977

Evidence for the presence of choleragen receptor on the thymocyte-brain antigen molecule of mice.

CBA thymocytes were subjected to cocapping experiments using AThy-1.2 and choleragen. The finding that both structures showed a common ligant-induced redistribution implies that choleragen receptors of the cell membrane are associated with the thymocyte-brain molecule. Furthermore, it was found that the thymocyte-brain antigenic determinants on the thymocyte were not blocked by prior choleragen treatment. This suggests a spatial distance between these structures on the molecule.

Animals↗
PubMed1977

Detection and molecular characterization of the thymus-brain antigen in human brain.

Anti-human brain sera were found to contain antibodies reacting with determinants present on murine thymocyte plasma membranes. This determinant is borne by the thymocyte-brain antigen of mouse thymocytes. The non species-specific determinant of the thymocyte-brain system is detectable on the thymocyte-brain antigen of human and mouse brain in comparable amounts. In contrast to these findings, the allogenic Thy-1 and the species-specific determinant of this system were only found on the thymocyte-brain antigen of mouse brain but not on the corresponding antigen of human brain. The molecular weight, Stokes radius and diffusion coefficient of the thymocyte-brain antigen of human and mouse brain are in good accordance with the data estimated for the corresponding antigen of murine thymocytes.

Animals↗