Biomedical subjects
R Stark
Publications and source records attributed to R Stark.
Frequency of brain metastasis in adenocarcinoma and large cell carcinoma of the lung: correlation with survival.
From January 1970 through December 1981, 469 patients with histologically or cytologically proven adenocarcinoma (AC) (349) and large cell carcinoma (LC) (120) of the lung were seen at the Department of Radiation Oncology, Medical College of Wisconsin Affiliated Hospitals. One quarter (126/469) of these patients had brain metastasis: 48 patients presented with brain metastasis (AC 35/349 = 10% and LC 13/120 = 11%) and 78 patients subsequently developed brain metastasis (AC 61/314 = 19%, LC 17/107 = 16%). Those patients who received prophylactic cranial irradiation were excluded from this study. Brain was the dominant site of metastasis in 82 patients who received only cranial + thoracic irradiation; 37 patients (17 simultaneous, 20 metachronous) also required irradiation of other sites of metastasis. All 17 patients with LC, and 47/61 (77%) with AC who developed metachronous brain metastasis did so within one year. The cumulative probability of brain metastasis increased with survival to the levels predicted by autopsy studies. Therapeutic brain irradiation may result in long-term survival in patients with single organ brain metastasis. Three of 119 patients who underwent whole brain irradiation for metastasis, are alive at 60 (LC), 48 (AC) and 48 months (AC) after treatment. Since patients with AC and LC so frequently develop brain metastasis and the brain may be the only site of metastasis, prophylactic cranial irradiation may significantly reduce morbidity and mortality from these diseases.
Pituitary portal blood flow in primates: a Doppler study.
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Purification and characterization of actin from normal and chronic lymphocytic leukemia lymphocytes.
Previous studies from this laboratory have shown actin to be a major protein of human lymphocytes (Stark, R., Liebes, L. F., Nevrla, D., and Silber, R. Biochem. Med., 27: 200-206, 1982). We now report the purification to homogeneity and characterization of actin from blood lymphocytes of normal subjects and patients with chronic lymphocytic leukemia. The recovery of the purified protein was about 20%. The properties of the lymphocyte actins were compared to each other and to those of rabbit skeletal muscle actin. Lymphocyte actin consisted of beta and gamma forms in a 2:1 ratio. The Mr 42,000 was determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Normal and leukemic lymphocyte actin had similar polymerization properties as assessed by viscosity measurements at 25 degrees and 4 degrees, and the ultrastructural appearance of the filaments was the same. Similar patterns were observed between normal and chronic lymphocytic leukemia actin tryptic digests analyzed by high-performance liquid chromatography. The Vmax of the actin-activated myosin Mg2+ ATPase activity was compared using rabbit skeletal muscle heavy meromyosin and subfragment 1 preparations. The values obtained with rabbit skeletal muscle and normal lymphocyte actin were identical. The Vmax observed with chronic lymphocytic leukemia lymphocyte actin was 70% of that obtained with normal lymphocyte actin. The amount of actin needed to produce half-maximal activation (Kapparent) of heavy meromyosin and subfragment 1 were, respectively, 26 and 25 microM for normal lymphocytes and 18 and 24 microM for chronic lymphocytic leukemia lymphocytes. The anomalous ATP activation by actin did not reflect differences in B-:T-cell subpopulations between chronic lymphocytic leukemia and normal lymphocytes. The possible significance of the observed differences between the myosin Mg2+ ATPase activation by chronic lymphocytic leukemia and normal lymphocyte actin is discussed.
The quantitation of actin in human lymphocytes by isoelectric focusing.
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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.
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.
Choices of operation for subclavian-vertebral arterial disease.
Subclavian-vertebral artery disease requires careful delineation of symptoms and offers a wide selection of operative procedures. The transition over a 10 year period from intra- to extrathoracic operations in a series of 35 patients is described.
Indications for transluminal angioplasty: a surgical view.
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Improvement in nerve condition after plasma exchange for Guillain-Barré syndrome.
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[Pipemidic acid--Deblaston].
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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.
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.
Modulation of cell membrane antigens during differentiation of rat T-lymphocytes.
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Detection and partial molecular characterization of the rat T-lymphocyte surface protein L21 by allo-(anti-RT-Ly-2.2) and xeno-(anti-RT-LN-LyIg) sera.
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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.
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.
The dental working environment and the risk of mercury exposure.
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