Biomedical subjects

E B Dowdle

Publications and source records attributed to E B Dowdle.

At least 55 records · Page 3Linked to original sources

PubMed1980

Molecular species of plasminogen activators secreted by normal and neoplastic human cells.

A survey of 56 normal and neoplastic tissues has shown that plasminogen activators were released by cultured human cells in several molecular weights and their susceptibility to inhibition by antibodies to the normal urinary enzyme, urokinase. Melanoma cells characteristically secreted plasminogen activators which were immunochemically distinct from urokinase and which migrated on sodium dodecyl sulfate-polyacrylamide gel electrophoresis as a prominent, closely spaced doublet with an apparent molecular weight of approximately 70,000 and a minor molecular weight component of approximately 60,000. Enzymes with similar characteristics have been observed in serum-free harvest fluids collected from other neoplastic tissue (a breast carcinoma, a glioblastoma, a malignant teratoma, a uterine sarcoma, and a carcinoma of the renal pelvis) and from normal tissue (8-week embryo fibroblasts, normal esophageal fibroblasts, and one culture of normal adult bladder epithelium). Plasminogen activators released by cells derived from most normal adult tissues, or from a 26-week-old embryo, and from other tumors of ectodermal or mesenchymal origin were inhibited by anti-urokinase antibody and showed a closely spaced doublet with a molecular weight of 60,000 as the most abundant molecular species with no evidence of the enzyme with a molecular weight of 70,000.

Antigen-Antibody Reactions↗

PubMed1979

Biochemical aspects of neutrophil chemotaxis.

Solutions of crude casein contain a chemotactic peptide with a molecular weight of 2 200 daltons. As in the case of other cytotaxins, this compound displays hydrophobic properties. Partially purified casein cytotaxin stimulated the disproportionate oxidation of glucose-1-carbon, from which we infer that hexose monophosphate shunt activity is increased in cells exposed to cytotaxin. No evidence could be found to support the suggestion that cytotaxin stimulation leads to activation of latent cellular esterases.

Animals↗

PubMed1979

Serum complement concentrations, nutritional status and the outcome of measles and measles pneumonia.

A prospective study of children with measles has shown a significant association between malnutrition and a poor prognosis. Levels of a number of complement components bore no relationship to the severity of the disease or to its prognosis. Some of the children with acute measles had depressed serum concentrations of factor D, Clq or C3, but complement deficiency does not appear to be implicated in the heightened susceptibility to secondary bacterial and viral infection so commonly found after acute measles.

Body Weight↗

PubMed1979

Deficiency in kwashiorkor serum of factors required for optimal lymphocyte transformation in vitro.

Blastogenic responses of normal human peripheral blood lymphocytes cultured in media supplemented with serum from children with kwashiorkor were, on average, 47.7% of those observed when the same cells were cultured in the presence of normal AB serum. Incorporation of radioactive uridine was also diminished in the presence of normal AB serum. Incorporation of radioactive uridine was also diminished in the presence of kwashiorkor serum indicating that lectin-induced RNA synthesis was also affected. The kwashiorkor serum effect was not due to a cytotoxic action nor could it be attributed to the presence of saccharides or other inhibitors of the inducing lectins. Mixing experiments showed that kwashiorkor serum was not inhibitory, but that it lacked factors present in normal serum that are required for optimal lymphocyte blastogenesis. The deficiency of these factors could largely be rectified by supplementing kwashiorkor serum with an ultrafiltrate of normal serum containing components with molecular weights of less than 500 Daltons. We conclude that nutritional deprivation of severity sufficient to cause kwashiorkor leads to a deficiency of low molecular weight lymphocyte growth factors. This lack may contribute to the immunodeficiency associated with the disease.

Cell Survival↗

PubMed1978

Serum factor affecting neutrophil function during acute viral hepatitis.

Sera from eight of 17 patients with acute viral hepatitis was deficient in its ability to support neutrophil bactericidal function in vitro. This defect appeared to be related to the viral infection itself. Sera from patients with drug hepatitis or mechanical obstructive jaundice did not show this effect.

Acute Disease↗

PubMed1978

Neutrophil chemotaxis: the kinetics of cellular locomotion in vitro.

The Boyden chamber system has been used to study the motile response of rabbit peritoneal neutrophils to partially purified casein cytotaxin. The results of these in vitro experiments indicate that neutrophils respond in two distinct ways to cytotaxin. Firstly, they increase their innate random mobility. Secondly, they respond to the information contained in a cytotaxin concentration gradient by exhibiting directional movement with a velocity vector directed towards the higher cytotaxin concentration. Since the two responses are kinetically distinct, one may infer that they are mechanistically distinct.

Animals↗

PubMed1978

The effects of kwashiorkor serum on lymphocyte transformation in vitro.

The serum from twelve children with kwashiorkor was deficient in its ability to support lymphocyte transformation in vitro, whereas lymphocytes from these children responded to phytohaemagglutinin and al-ogeneic lymphocytes in a relatively normal manner when cultured in normal serum. This serum abnormality improved with therapy and could not be clearly correlated with the degree of malnutrition, the presence or absence of infection or other laboratory manifestations of kwashiorkor. These observations indicate that defective cellular immune reactions in kwashiorkor may be symptomatic of a lack of some humoral factor and do not necessarily reflect an intrinsic cellular defect.

Blood Proteins↗

PubMed1977

The effect of prolonged isolation from environmental allergens on the clinical and laboratory manifestations of the allergic state. Observation on members of the South African Antarctic expedition.

The 1975 South African Antarctic expedition included 8 men with a history of allergy, 7 who showed cutaneous hypersensitivity to common allergens, but denied having experienced symptoms, and 6 who had neither symptoms nor positive skin tests. During a year of residence in the essentially allergen-free, barren environment of Antarctica, allergic subjects were entirely sypmtom-free. Prolonged isolation from environmental allergens did not consistently diminish the serum concentration of total or specific IgE or the intensity of positive skin test reactions, which indicates that the cells responsible for the synthesis and secretion of reaginic antibodies have a prolonged existence and do not require repeated allergenic stimulation for maintenance of function.

Allergens↗

PubMed1977

Studies on Bermuda grass pollen allergens.

Two allergens, BGP-1 and BGP-2, were identified in crude Bermuda grass pollen extract. BGP-1 was a major allergen and elicited a skin reaction in all subjects sensitive to the crude extract, whereas BGP-2 was a minor allergen and elicited a reaction in only 75% of such subjects. Calibrated column chromatography was used to determine the molecular weights and Stokes radii of the allergens. For BGP-1 they were 30 000 daltons and 24,3 X 10(-8) cm respectively and for BGP-2 they were 14 000 daltons and 18,1 X 10(-8) respectively. The sedimentation coefficient (S20,w) of BGP-1 on sucrose density gradient ultracentrifugation was 3,1 and on iso-electric focusing its iso-electric point was found to be pH 5,4. The reason why only certain individuals sensitive to BGP-1 are sensitive to BGP-2 is discussed. It is possible that the former is a dimer of the latter.

Centrifugation, Density Gradient↗

PubMed1976

Chronic granulomatous disease of childhood.

Two boys and one girl suffering from recurrent severe bacterial infections were investigated. All 3 exhibited normal cellular and humoral immunity, normal neutrophil phagocytic ability, and defective neutrophil bacterial capacity. The clinical features and laboratory findings in these patients are diagnostic of chronic granulomatous disease. A sex-linked inheritance pattern was confirmed in 1 patient by the demonstration of a heterozygous carrier state in the mother.

Child, Preschool↗

PubMed1975

Serum immunoglobin E concentrations of allergic patients and blood donors. Influence of allergy, sex and race on IgE values.

Serum IgE concentrations were measured in allergic subjects attending the Allergy Clinic at Groote Schuur Hospital, Cape Town. White and Cape Coloured clinic subjects had serum IgE concentrations which were significantly higher than those found in comparable groups of either non-allergic blood donors or blood donors with symptoms of allergy; in Blacks these differences were not apparent. Although serum IgE concentrations in clinic subjects tended to increase in the order White -- Cape Coloureds -- Blacks, these racial differences were not as pronounced as in blood donors. Also, olinic subjects showed no sex difference in serum IgE concentrations.

Adolescent↗

PubMed1975

The effects of sex and age on serum IgE concentrations in three ethnic groups.

Serum IgE concentrations were measured using a radio-radial immunodiffusion method in 4,440 blood donors resident in the Western Cape Province, South Africa, and the following differences were observed. Firstly, in all three ethnic groups studied, that is the Whites, the Cape Coloureds and the Africans, there was a tendency for males to have higher serum IgE concentrations than females. This differences was highly significantly in Whites. Secondly, in the Whites, serum IgE concentrations tended to be lower with advancing age. Thirdly, previous reports of elevated serum IgE concentration in indigenous African population were confirmed. No clearly defined cause for these differences emerged rom this study.

Adolescent↗

PubMed1975

Effects of allergy, intestinal helminthic infestation and sex on serum IgE concentrations and immediate skin hypersensitivity in three ethnic groups.

Serum IgE concentrations were measured in 232 blood donors resident in the Western Cape, South Africa. Subjects were interviewed for histories of allergy and skin tested with a variety of common allergens. Faecal specimens were collected for microscopic examination. Results confirmed that Cape Coloureds and Africans tend to have elevated serum IgE concentrations and showed that African males have a high prevalence of immediate skin hypersensitivity. Cape Coloureds and Africans had high prevalences of helminthic infestation and relatively low prevalence of allergic symptoms. Only in Whites were elevated serum IgE concentrations associated with positive allergic histories; in this group, results suggested that the sex difference in serum IgE concentrations observed previously is owing to differences in the IgE responses of allergic males and females.

Blood Donors↗

PubMed1974