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Biomedical subjects

R Barton

Publications and source records attributed to R Barton.

At least 73 records · Page 4Linked to original sources
PubMed1979

Carcinoma of the lip.

We reviewed 250 patients with carcinoma of the lip who were treated with radiation therapy during a 30-year period. Although radiation techniques underwent continued refinement, the radiation dose delivered to the tumor remained relatively constant. Nearly all tumors were squamous cell carcinoma (247/250) and located on the lower lip (240/250). Only 9% initially manifested lymph node metastases. The median survival was 13.8 years. Treatment failure occurred in 11% of patients. Surgery salvaged half of these patients. Eighteen patients died from carcinoma of the lip, and six others had persistent tumor when last seen. Our experience would support the work of others. Early lesions can be successfully managed by either surgical or radiation treatment. The intermediate tumors and those near the commissure are better handled by radiation. Late lesions and those with lymph node metastases challenge the best surgical and radiation techniques.

Adult↗
PubMed1979

The distribution of adenosine deaminase among lymphocyte populations in the rat.

Adenosine deaminase (ADA) activity was determined in young rat lymphocyte populations. The ADA-specific activity (per 10(8) cells and per milligram protein) was 3- to 10-fold higher in thymocytes than in lymphocytes from thoracic duct, lymph node, spleen, and bone marrow. The high ADA activity in thymocytes appeared to be preferentially associated with cortical thymocytes. Enrichment or depletion of cortical thymocytes by density gradient centrifugation, cortisone treatment, or selective lysis with anti-Thy-1 plus complement resulted in parallel increases or decreases in ADA levles. These results also suggested that medullary thymocytes have ADA levels similar to those of peripheral lymphocytes. "Immature" cortical thymocytes and thymocyte progenitors appeared to have low ADA activity; low enzyme levels were found in fetal thymus at 16 days of embryonic life, in the early phases of thymus regeneration, and in a "null" cell population isolated from bone marrow. This study demonstrates that ADA activity varies markedly during T lymphocyte differentiation and suggests that fundamental differences in nucleotide metabolism may exist in T cells at different stages of development.

Adenosine Deaminase↗
PubMed1977

Malignant teratoma of the nasal cavity.

A case of malignant teratoma of the nasal cavity in an adult is presented. Histologically, the tumor consisted of mesenchymal malignant structures in addition to entodermal and ectodermal malignant elements. Whereas surgical treatment of the primary tumor has been generally considered preferred, this patient was given a full course of radiation therapy alone to the primary lesion. There is no clinical evidence of tumor 5 years following diagnosis. Three years following treatment of the primary tumor, neck lymph node metastasis appeared contralaterally. Management of this problem was with radical neck dissection followed by postoperative radiotherapy. Function of the eyes, nose, and paranasal sinuses remains normal. A review of the literature suggests that radiotherapy is of little value in the management of malignant teratomas. This case demonstrates an opposite point of view.

Ethmoid Sinus↗
PubMed1976

The distribution of terminal deoxynucleotidyl transferase (TdT) among subsets of thymocytes in the rat.

Terminal deoxynucleotidyl transferase (TdT), a unique DNA-polymerizing enzyme,has been shown to be present in a moderately dense subpopulation of rat thymocytes separated on discontinuous Ficoll density gradients. This subpopulation has been characterized by using antigenic and functional markers to identify directly and quantify cortical and medullary thymocytes. The TdT-positive thymocytes are depleted by cortisone administration, lack responsiveness to phytohemagglutinin, concanavalin-A, and histocompatibility alloantigens, bear surface antigens characteristic of cortical thymocytes (bone marrow lymphocyte antigen) and lack surface antigens characteristic of medullary thymocytes (rat-masked thymocyte antigen and histocompatibility antigens). The results indicate that TdT is present exclusively (or in markedly higher concentrations) in a subset of cells which comprised about 65% of cortical thymocytes. Two other major subsets of cortical thymocytes were identified which appeared to be TdT-negative. A minor subset of very low density cortical thymocytes was also defined. These observations have provided insight into the possible pathways of thymocyte ontogeny.

Animals↗
PubMed1975

Abandoning the mentally ill.

Mentally ill people have been avoided and abandoned by their families and public authorities for hundreds of years. Present day abandonment includes the deployment of professionals from patients to paper; the destruction of availability and effectiveness of institutional facilities; the obfuscation of mental illness by captious, sematic criticism; the aspirations of paramedical and paraprofessional groups; and the subordination of the primary purpose of institutions and physicians to other objectives. The nature of authority is discussed and the need for the treatment of mentally ill people to be based on the art and science of medicine, rather than the pretension and advocacy of the gullible, unqualified or unscrupulous, is noted.

Attitude of Health Personnel↗
PubMed1975

Technique for determining nickel in blood by flameless atomic absorption spectrophotometry.

We describe a technique for determining nickel in serum by flameless atomic absorption, with use of dimethylglyoxime. The procedure permits a greater number of analyses per technician at a relatively low cost, yet provides acceptable accuracy and reliability. After the sample is evaporated and dry ashed in a muffle furnace at 560 degrees C for 5 h, the residual salts are dissolved in hydrochloric acid (1 mol/liter). Sodium citrate and dimethylglyoxime are then added for complexation of iron and nickel, respectively. The pH is adjusted to 9 with ammonia and the nickel dimethylglyoxime is extracted with methyl isobutyl ketone. The determination is carried out by injecting 50 mul of the organic phase into the graphite furnace, where the sample is dried at 120 degrees C and ashed at 1200 degrees C, respectively.

Deuterium↗