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Biomedical subjects

R Graham

Publications and source records attributed to R Graham.

At least 91 records · Page 5Linked to original sources

Collagenase production by rheumatoid synovial cells: stimulation by a human lymphocyte factor.

Human peripheral blood lymphocytes incubated in culture for 1 to 3 days at 37 degree C, but not at 4 degree C, release a soluble factor which can stimulate, up to 400-fold, collagenase production by isolated, adherent, rheumatoid synovial cells. Production of lymphocyte factor is enhanced by phytohemagglutinin or concanavalin A. By gel filtration the factor has an apparent molecular weight of about 12,000.

Arthritis, Rheumatoid

Metabolism of bile alcohols in the perfused rabbit liver - C26 bile alcohols.

The metabolism of a C26 bile alcohol (I, 24-nor-5beta-cho-lestane-3alpha, 7alpha,25-triol) was studied in the isolated perfused rabbit liver. The new bile alcohol and bile acid metabolites secreted into the bile were isolated and identified by a combination of TLC, GLC and GLC-MS. The following bile alcohols were found: II, 24-nor-5beta-cholestane-3alpha,7alpha,12alpha,25-tetrol, III, 24-nor-5beta-cholestane-3alpha,7alpha,12alpha,25,26-pentol; IV, 24-nor-5beta-cholest-23-ene-3alpha,7alpha,12alpha-triol; and V, 24-nor-5beta-cholest-23-ene-3alpha,7alpha-diol. In the bile acid fraction, 24-nor-cholic acid and 3alpha,7alpha,12alpha-trihydroxy-24-nor-5beta-cholest-23-en-26-oic acid were present. The perfused nor-triol was not resistant to 12alpha-hydroxylation.

Animals

Increased clonogenic (CFU-C, PFU-C) populations from bone marrow and spleen of nude mice.

Clonogenic populations from bone marrow and spleen of nude mice and their normal littermates were enumerated in vitro using a methylcellulose supported culture system. This technique allows for the simultaneous quantitation of progenitors of granulocyte-monocyte pathways (colony forming units in culture, CFU-C) and for progenitors of "mesenchymal" elements (plaque-forming units in culture or PFU-C). These populations were distinguished in culture by their growth, characteristics and morphology. CFU-C gave rise to suspended colonies of granulocyte-monocyte composition while PFU-C formed surface-adherent colonies of mesenchymal morphological features (fibroblastic and reticuloendothelial morphology). Significant elevations in the relative and absolute numbers of CFU-C and PFU-C were observed in the bone marrow and spleen of 6 wk old nu/nu mice relative to heterozygous littermates. The results are discussed in terms of non-T cells components involved in cell-medited immunity against neoplastic development.

Age Factors

Role of pressure gradients and bulk flow in dynamics of vasogenic brain edema.

The authors present the results of an investigation of the vasogenic type of brain edema using cold injury in cats as a model. Their findings indicate that bulk flow and not diffusion should be considered the main mechanism for the spread of edema through the white matter. This conclusion is based on: 1) comparison of the distances actually traveled by various substances during edema spread with those calculated theoretically for migration of the substances by diffusion; 2) coincidence in the speed of movement by two substances (sucrose and albumin) with widely different diffusion coefficients; 3) measurement of interstitial fluid pressure (IFP) at various distances from the lesion showing the presence of increased IFP in the lesion area and decreasing pressures along the edema pathway toward the normal tissue; and 4) the fact that spreading of edema can be significantly impeded by inducing before the cold lesion an intracellular type of brain edema that reduces the size of the extracellular space (ECS) and increases the resistance to flow of edema fluid. The pressure-volume curve of the brain ECS, as derived from determinations of IFP and tissue water content, indicates that initial steep slope in IFP probably represents the high resistance to fluid mobility through the small diameter extracellular channels and the counteracting resistance of the intermingled structures of brain parenchyma to be separated. Once the IFP exceeds these opposing forces, the ECS dilates, fluid mobility increases, and the edema front advances.

Animals

Central nervous system involvement in mycosis fungoides: pre mortem diagnosis by light and electron microsocopic study of the spinal fluid.

Involvement of the brain, spinal cord, peripheral nerves, meninges, and cerebrospinal pathways in mycosis fungoides manifests itself, clinically, as an obscure neurologic disturbance, occurring in patients with cutaneous manifestations of that disorder. Neurologic expressions of this particular cutaneous lymphoma are infrequently reported, in spite of the fact that many patients dying in the course of mycosis fungoides have pathologically demonstrable central nervous system, peripheral nervous system, and meningeal involvement. We report here a patient who incurred devastating neurologic illness as one of the initial features of the course of systemic dissemination of mycosis fungoides. Death occurred nine years after the onset of cutaneous illness. In this instance, cerebrospinal fluid cytologic studies established the diagnosis of nervous system involvement. Mycosis fungoides cells shed into the cerebrospinal fluid were studied by special techniques of light and electron microscopy. Brain scan abnormalities were present, which were clinically correlative with foci of brain involvement. The initial response of patient's nervous system illness to therapy was gratifying but unsustained, and she went on to fatal brain and multiple organ involvement with disseminated mycosis fungoides. The techniques of spinal fluid cytologic diagnosis, confirmatory of the etiology of disease in this case, may have practical appications in the diagnosis of otherwise obscure neurologic disorders.

Adult

The effect of the organization and status of family practice undergraduate programs on residency selection.

Family practice, as a medical specialty, is designed to help fill the void in primary care availability. In order to expose medical students to family practice and provide a basis for choosing a residency in the field, many medical schools have developed undergraduate programs in family practice. This paper reports the results of a survey conducted in March 1975 on the status of undergraduate programs with particular focus on the relationships between administrative status, size of program, faculty size, and type of undergraduate curricula to the number of graduates choosing family practice as a specialty. The data indicate that there is a relationship between the commitment of the school to family practice, the size of the program, and the presence of required courses in the curriculum to the success of the program, as measured by the proportion of students in each school who choose family practice residencies.

Education, Medical, Undergraduate

The effect of several diphosphonates on acid phosphohydrolases and other lysosomal enzymes.

Diphosphonates are known to inhibit bone resorption in tissue culture and in experimental animals. This effect may be due to their ability to inhibit the dissolution of hydroxyapatite crystals, but other mechanisms may be important. Since lysosomal enzymes have implicated in the process of bone resorption, we have examined the effect of several phosphonates and of a polyphosphate (P20,2) on lysosomal hydrolases derived from rat liver and rat bone. Dichloromethylene diphosphonate strongly inhibited acid beta-glycerophosphatase (EC 3.1.3.2) and acid p-nitrophenyl phosphatase (EC 3.1.3.2) and to a lesser degree (in descending order) acid pyrophosphatase (EC 3.1.3.-), arylsulfatase A (EC 3.1.6.1), deoxyribonuclease II(EC 3.1.4.6) and phosphoprotein phosphatase (EC 3.1.3.16) of rat liver. Inhibition of acid p-nitrophenyl phosphatase and arylsulfatase A was competitive. Ethane-1-hydroxy-1, 1-diphosphonate did not inhibit any of these enzymes, except at high concentrations. Neither dichloromethylene diphosphonate nor ethane-1-hydroxy-1, 1-diphosphonate had any effect on beta-glucuronidase (EC 3.2.1.31), arylesterase (EC 3.1.1.2) and cathepsin D (EC 3.4.23.5). Of several other phosphonates tested only undec-10-ene-1-hydroxy-1, 1-diphosphonic acid inhibited acid p-nitrophenyl phosphatase strongly, the polyphosphate (P20, I) had little effect. Acid p-nitrophenyl phosphatase in rat calvaria extract behaved in the same way as the liver enzyme and was also strongly inhibited by dichloromethylene diphosphonate, but not by ethane-1-hydroxy-1, 1-diphosphonate. It is suggested that the inhibition of bone resorption by dichloromethylene diphosphonate might be due in part to a direct effect of this diphosphonate on lysosomal hydrolases.

Acid Phosphatase