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Biomedical subjects

R Miller

Publications and source records attributed to R Miller.

At least 757 records · Page 42Linked to original sources

Immunologic phenotype in 30 patients with diffuse large-cell lymphoma.

Frozen sections of 30 diffuse large-cell ("histiocytic") lymphomas that had arisen in both nodal and extranodal sites were stained with immunoglobulin light-chain and heavy-chain reagents, with nonoclonal antibodies to THAT HAD ARISEN IN BOTH NODAL AND EXTRANODAL SITES WERE STAINED WITH IMMUNOGLOBULIN LIGHT-CHAIN AND HEAVY-CHAIN REAGENTS, WITH MONOCLONAL ANTIBODIES TO T and B-cell antigens, and with an esterase marker for macrophages. Fourteen lymphomas expressed immunoglobulin light chains and were shown to be monoclonal; F(ab')2 fragments were sometimes necessary to demonstrate their monoclonal nature. Mu (IgM) was the most frequently expressed heavy chain, but in many patients other heavy chains were found. None of the lymphomas stained with T-cell antibodies or the esterase; 15 did not stain for immunoglobulin, but 13 of these 15 did express Ia antigen. These immunologic markers identified eight different phenotypes. Retrospective clinical analysis of the patients suggested that those who were immunoglobulin-positive had more advanced disease and shorter survival, but confirmation of the clinical relevance of immunologic phenotype will require prospective studies.

Adult↗

Malignant inflammatory histiocytoma (inflammatory fibrous histiocytoma): report of a patient with four lesions.

A patient with four subcutaneous inflammatory fibrous histiocytomas is presented. Three of these tumors developed synchronously. The neoplasms were examined by light and electron microscopy and were composed of well differentiated histiocytes, multinucleated histiocytes, and less differentiated cells. The ultrastructural findings support the histiocytic nature of this particular tumor.

Female↗

Sex chromosome aneuploidy and anthropometry: a new proportionality assessment using the phantom stratagem.

Reported anthropometric data on 121 subjects with 47,XYY,47XXY,47,XXX, and 45,X aneuploidies were compared to those from 578 male and female control subjects by use of a single, unisex reference person ("phantom"). Subjects and controls were geometrically scaled to a standard stature of 170.18 cm, thus eliminating variance due to height. Deviations of anthropometric variables from specified phantom values were expressed as standard z-scores. By comparing z-scores of individual aneuploidy classes with those of their controls, further differences in proportionality came to light. The stratagem disclosed a systematic proportionality pattern between subjects and controls which appeared to be related to each specific sex chromosome aneuploidy. The phantom stratagem for proportional growth assessment appears to merit further use in genetic investigations where individual differences in size and shape confound the analysis of anthropometric data.

Anthropometry↗

Pharmacokinetics of doxycycline reabsorption.

Two cyclic linear compartment models are proposed to investigate the reabsorption mechanism of doxycycline. In one model, reabsorption is considered to be continuous; in the other model, it is discontinuous. The continuous model, when fitted, leads to one real and two complex conjugate eigenvalues, corresponding to a regression equation consisting of a regular exponential term and an exponentially damped trigonometric expression. In spite of the apparent oscillatory nature of this regression equation, the fitted curves show no secondary peaks or humps apparent in the data. Simulation studies indicate that it may not be possible to get response profiles showing secondary peaks or humps that are experimentally detectable with linear compartment systems with cyclic pathways and continuous transfer. The model with discontinuous cyclic transfer was more flexible in describing the discrepancies in the data and appeared to be preferable to the continuous cyclic transfer model judged by the Akaike information criterion.

Absorption↗

Pharmacokinetics and bioavailability of cimetidine in humans.

Cimetidine given orally without food after an overnight fast produces a blood concentration curve with a pronounced second peak that does not appear after parenteral administration or when the drug is taken with food. The following interpretation of this kinetic phenomenon is proposed: 1. The drug cumulates in a tissue or organ that is well perfused in the first-pass transfer. 2. The hepatic parenchymal tissue and the bile phase are the most likely storage areas. 3. The high capacity of the cumulation may be due to the formation of conjugates or other modifications of the drug with a pronounced affinity for the hepatic-biliary system. 4. The rate of cumulation is much higher in the first-pass transfer than from the systemic circulation, possibly due to the difference in the drug concentrations and the conjugation rate. 5. The cumulation appears to occur by a competitive process. 6. Absorbed elements of food seem to compete in this process. 7. The second peak apparently is the result of a rapid release of drug and bioreversible drug compounds from the hepatic-biliary system with subsequent reabsorption. 8. This release may occur spontaneously but appears to be triggered by food intake. A pharmacokinetic model constructed according to this interpretation showed good agreement with data from oral, intravenous, and intramuscular administration. The special problems associated with the evaluation of bioavailability in the presence of reabsorption are discussed.

Administration, Oral↗

Isolation of factors in linseed oil meal protective against chronic selenosis in rats.

Two new cyanogenic glycosides, linustatin and neolinustatin, were isolated from linseed oil meal. Each of the compounds was fed to rats in a corn-based diet at levels of 0.1 and 0.2%. At the 0.2% level, both substances gave significant protection against growth depression caused by 9 ppm selenium as sodium selenite. Both compounds also promoted a significant increase in liver and kidney weight over the selenium control animals. Linustatin and neolinustatin are closely related in structure to linamarin and lotaustralin and were found to be present in linseed oil meal at levels of 0.17 and 0.19%, respectively. Linamarin fed at the level of 0.2% also gave significant protection against growth depression and liver damage. A related cyanogenic glycoside, amygdalin, appeared to give a small but nonsignificant protective response. The isolation of the two new glycosides provides a probable explanation for the protective activity of linseed oil meal against selenium toxicity.

Amygdalin↗

Phycomycosis of the horse caused by Basidiobolus haptosporus.

A case of subcutaneous phycomycosis of a horse from which Basidiobolus haptosporu was isolated is described. Although some clinical signs were similar to the disease caused by Hyphomyces destruens, the gross and microscopic pathology were different in several respects. Main characteristics of the histopathology were the narrow eosinophilic sleeve around wide, frequently septate hyphae scattered throughout the affected tissue and found commonly at the advancing border of the lesion. A retrospective study of 63 cases of phycomycosis diagnosed at this laboratory since 1970 indicated a further 11 cases with similar histological features. The significance of this finding for the epidemiology and pathogenesis of equine dermal granulomas is discussed.

Animals↗

Lymphocyte subpopulations and function in chronic murine toxoplasmosis.

A long-lasting, chronic infection with Toxoplasma gondii was established in C57Bl/6J mice as a model system of slow parasite infection. We quantified all nucleated cells and Thy-1+ and Thy-1- cell subpopulations in thymus, spleen and peripheral and mesenteric lymph nodes throughout the first 8 months of life of mice infected at 8 weeks of age. We found a physiological pattern of change with age in the lymphocyte subpopulations examined; the pattern was distinctive for each lymphoid organ. These normal patterns were altered in infected mice from the beginning of the observation period. The most prominent findings were (a) a relatively early atrophy of the thymus and (b) no increase in Thy-1+ lymphocyte numbers in either spleen or lymph nodes during the first 3 months post-infection, followed by decreasing numbers afterwards. Other findings were a rapid increase in the number of Thy-1- cells in the thymus before the onset of generalized atrophy; accumulation of erythrocytes in the spleen and splenomegaly during the first 3 months post-infection, despite a steady decrease in the number of nucleated cells; and an increase in Thy-1- cells in the peripheral but not in the mesenteric nodes, thereby diluting the Thy-1+ lymphocyte subpopulation.

Aging↗

A two-compartment model for digoxin disposition in dogs.

The disappearance of digoxin from heart and skeletal muscle was studied in dogs using a sequential biopsy technique. The animals were injected with digoxin for five days and subsequently with 3H-digoxin for an additional three days. 12, 24, and 48 h after discontinuation of digoxin, tissue samples of left ventricle, left atrial appendage, and skeletal muscle were taken. In addition, digoxin serum levels were measured. With the help of a computer program, a mathematical model was developed for the description of the disposition and elimination of digoxin from tissue. Disappearance from plasma and tissue was consistent with a two-compartment open model.

Animals↗