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Biomedical subjects

D R Nash

Publications and source records attributed to D R Nash.

At least 55 records · Page 3Linked to original sources
PubMed1979

Serum immunoglobulin abnormalities in patients with respiratory tract disease.

Serum immunoglobulin concentrations in patients representing four different categories of respiratory diseases are compared with each other and with an age related group of healthy voluntees. Natural immune stimulation of the respiratory tract results in a significant rise in serum IgA and IgG but not IgM. A comparision with their respective normal serum control values further indicates that the major increase is within the IgA class and, that although significant, the rise in IgG is relatively minor. The preferential serum IgA response observed in the patient population suggests that bronchial associated lymphoid tissue in the diseased lung is an important source of circulating IgA.

Aged↗
PubMed1976

Ventilatory defects in atypical mycobacteriosis. A comparison study with tuberculosis.

Two hundred thirty-two patients infected with Mycobacterium kansasii and 120 patients infected with M. intracellulare who were admitted to the East Texas Chest Hospital between 1965 and 1974 were individually matched according to age (+/- 5 years), sex, and extent of disease with an equal number of patients infected with M. tuberculosis. The ventilatory function in these patients was compared. The frequency of obstructive ventilatory defect, defined as forced expiratory volume in 1 sec less than 70 per cent of forced vital capacity, was greater among M. kansasii patients (68.9 per cent of 232) than among M. tuberculosis patients less than 80 per cent of predicted, was greater among M. intracellulare patients (68.3 per cent of 120) than among M. tuberculosis patients (57.5 per cent of 120). Above age 40, obstructive ventilatory defects tended to be more common in M. kansasii patients, whereas restricted ventilatory defects tended to be more common in M. intracellulare patients when compared with the same age group of M. tuberculosis patients. As expected, ventilatory function values among the M. tuberculosis groups decreased as extent of disease increased. In contrast, among the M. kansasii and M. intracellulare groups, these values were poorly related to the extent of disease; values were relatively low even with minimal extent of disease. It is suggested that the increased ventilatory defects among the M. kansasii and M. intracellulare patients could be accounted for by coexistent lung disease.

Adolescent↗
PubMed1975

The effect of metal ions on the atypical mycobacteria: growth and colony coloration.

The effect of 30 metal ions on growth and colony color has been evaluated for 215 isolates of "atypical" mycobacteria and 5 isolates of Mycobacterium tuberculosis. Of the total number of ions tested, ten proved to have a variable effect on growth and eight induced specific changes in colony coloration. Although both effects could be generally related to the Runyon grouping system, neither procedure proved to be practical or specific for differential identification of individual species. Spectrophotometric analyses of acetone extracts were made from representative strains of "atypical" mycobacteria, grown in the presence (test) or absence (control) of metal ions, in an attempt to determine the chemical nature of metal ion induced color changes in colonies of these organisms. Induced colors were not extractable with organic solvents, indicating that these colors are not lipid associated. In all cases where applicable (chromogenic strains) the naturally occurring carotenoid pigments were found to be unaffected, in their spectral properties, by the presence of metal ions even though the natural yellow color was frequently masked by the ion induced colors. The close association of metal ion induced colors with acetone nonextractable cell components suggests the presence of reduced metal ions or the formation of metal hydroxides. The apparent presence of several metal ion reductase systems and their physiological implications are discussed.

Metals↗
PubMed1972

Recovery of dengue viruses from tissues of experimentally infected rhesus monkeys.

A tissue explant culture technique for the recovery of dengue virus from experimentally infected monkey tissue is described and compared with tissue culture assay of tissue triturates and co-cultivation of trypsinized cells in cell cultures. The most efficient technique was one in which minced tissue was explanted in co-culture with dengue virus-susceptible LLC-MK2 monkey kidney cells. This technique shows promise of being useful for detection of virus in autopsy material from fatal dengue hemorrhagic fever cases.

Animals↗
PubMed1971

Nonspecific factors in monkey tissues and serum causing inhibition of plaque formation and hemagglutination by dengue viruses.

Normal monkey serum and the supernatant fluid from different triturated monkey tissues have been studied for the presence of nonspecific arbovirus hemagglutination and plaque forming inhibitors of dengue viruses types 1, 2, 3, and 4. Hemagglutination inhibition (HI) activity was present in most tissue specimens and demonstrated a significant gradient of effectiveness starting with, respectively, serum, spleen, adrenal, and lung having a high degree of activity, whereas skin, heart, muscle, brain, and liver demonstrated low HI titers. A slightly reversed gradient of effectiveness was obtained for the case of dengue virus inhibition of plaque formation with bile, liver, thymus, spleen, and adrenal giving high 50% plaque reduction titers and heart, muscle, serum, skin, and fat demonstrating little or no activity. Analysis by Sephadex G-200 chromatography and sucrose density gradient centrifugation suggests that HI and plaque formation inhibition are independent activities of normal serum or tissue constituents or both. Also, in addition to the physical methods of characterization, chemical treatment by absorption with kaolin or acetone extraction indicate both phenomena to be the result of the action of lipids or lipoproteins.

Journal Article↗
PubMed1969

Antibodies of the IgA type in intestinal plasma cells of germfree mice after oral or parenteral immunization with ferritin.

In adult germfree C(3)H mice immunized with horse spleen ferritin, either subcutaneously or intraperitoneally, plasma cells containing specific antibodies were found in lymph nodes and spleen and, in smaller numbers, also in the lamina propria of the intestine. In extraintestinal sites, these antiferritin-containing plasma cells were mainly of the IgM class after a single stimulation, and of the IgG(1) class after repeated stimulation. In the intestine, all the anti-ferritin-containing cells appeared to be of the IgA class. Circulating antibodies, after repeated stimulation, were for the major part IgG(1) and IgG(2). In germfree mice given ferritin in their drinking water, antiferritin-containing cells were abundant in the intestinal mucosa, much less numerous in the mesenteric lymph nodes, and extremely scarce in other lymphoid tissues. All these cells, whatever their location, appeared to belong exclusively to the IgA class. Similarly, all the circulating antibody in these animals was found to be IgA. These findings illustrate the role of the gut as a site of antibody synthesis, as well as its selective commitment to the production of antibodies of the IgA class.

Animals↗