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Biomedical subjects

R L Clancy

Publications and source records attributed to R L Clancy.

At least 163 records · Page 9Linked to original sources
PubMed1981

Disordered immune homeostasis in chronic idiopathic thrombocytopenic purpura.

A T:B co-culture system was used to test for the presence of disordered immune homeostasis in the autoimmune disease, chronic idiopathic thrombocytopenic purpura (ITP). Various numbers of T cells were added to a fixed number of B cells in the presence or absence of the polyclonal activator, pokeweed mitogen, and IgG production measured in the culture supernatants 6 days later. The results demonstrated a defect in T cell-dependent suppression and/or a state of B cell hyper-responsiveness in lymphocytes from patients compared to normal controls. The loss of T cell-dependent suppression could not be readily explained in terms of the therapy being used nor by the presence of circulating IgG containing immune complexes. The findings of a similar abnormality in some cases of non-immune thrombocytopenia suggested that the reduction in suppression observed in chronic ITP was unlikely to be a primary event in disease pathogenesis, although it could well contribute to the ongoing autoimmune response.

Adult↗
PubMed1981

Increased circulating T alpha lymphocyte population in bronchogenic and colonic carcinoma.

The proportion of T lymphocytes bearing membrane receptors for IgA (T alpha cells) was markedly increased in the peripheral blood of patients suffering from cancers of the colon and bronchus compared to an age-matched normal population and to age-matched control patients being treated for non-malignant chronic inflammatory conditions of the intestine and lung. By contrast, the percentage of the T lymphocyte population having Fc-IgG receptors (T gamma cells) and Fc-IgM receptors (T mu cells) in mucosal malignancy was similar to that found in the two control populations. It is suggested that the increased percentage of T alpha cells found in colonic and bronchogenic carcinoma patients may reflect an as yet unknown regulatory function for this subset.

Carcinoma, Bronchogenic↗
PubMed1980

Immune complexes in thrombocytopenic patients: cause or effect?

Immune complexes (ICs) in the serum of 43 patients with chronic idiopathic thrombocytopenic purpura (ITP) were measured by the C1q deviation assay during the active and inactive phases of the disease. An inverse relationship between platelet count and levels of ICs was demonstrated in all but one patient. To test whether this phenomenon was specific for chronic ITP, ICs were assayed in sera from two groups of control patients with thrombocytopenia. Goup 1 had thrombocytopenia due to recognized immune mechanisms while group 2 had thrombocytopenia secondary to non-immune mechanisms. In both these groups the degree of thrombocytopenia proved to be inversely proportional to IC levels, which was similar to the pattern observed in chronic ITP. The specificity of the assay for detection of ICs was confirmed by demonstrating a positivity rate of 65% in sera of patients with systemic lupus erythematosus, a known IC disease. On analysis the ICs were shown to have molecular weights in excess of 500,000 daltons and contain variable immunoglobulin classes. The findings implicate ICs in immune destruction of platelets both in chronic ITP (as has been suggested previously) and also in thrombocytopenia secondary to known immune mechanisms. In addition the association of ICs with non-immune thrombocytopenias is consistent with the hypothesis that platelets play an important role in clearance of ICs from the circulation, thereby protecting the vascular endothelium from damage.

Antigen-Antibody Complex↗
PubMed1978

An Australian exclusion diet.

Exclusion diets may have a practical place in determining the precipitating dietary factors in certain clinical conditions. We present an exclusion diet which is based on the exclusion of food commonly known to cause food allergies, and the exclusion of food which contains salicylates, benzoates, tartrazine, yeast, and penicillin. This provided a basis for challenge with these additives and natural chemicals. Preliminary information in urticaria suggests a use for this diet in some allergic conditions.

Australia↗
PubMed1978

The effect of dibutyryl cyclic AMP and glucagon on the myocardial cell pH1.

DBcAMP or crystalline glucagon was utilized to elevate the intracellular cyclic AMP concentration in isolated rat hearts. Butyric acid, a metabolite of DBcAMP, was also investigated. Their effect on the intracellular pH (pHi) as determined by the distribution of [14C]DMO was investigated. Rat hearts, perfused with a recirculated modified Krebs-Henseleit solution maintained at 30 degrees C, were exposed to respiratory acidosis by bubbling the perfusate with 20% CO2. alpha- and beta-receptor antagonists were used to block the effects of endogenous catecholamines. Hypercapnia decreased the pHi from 7.09 to 6.82. A similar degree of hypercapnia decreased the pHi to only 6.95 in the presence of DBcAMP and to only 6.96 in the presence of glucagon. The effective buffer values (delta[HCO-3]i/deltapHi) were: control, 19; butyric acid, 16; DBcAMP, 139; glucagon, 148. These data suggest that cAMP mediates the effect of norepinephrine, which has been shown to diminish the change in pHi accompanying respiratory acidosis.

Acid-Base Equilibrium↗
PubMed1978

Immunologic "memory" for microbial antigens in lymphocytes obtained from human bronchial mucosa.

Memory for previous immunologic contact with microbial antigens has been detected in lymphocytes from human bronchi as a secondary immune response, when tested in vitro. Antigens stimulated a predominantly proliferative response in blood lymphocytes that was significantly greater than the response in mucosal lymphocytes with purified protein derivative and Herpes simplex type 1 antigens. Co-culture experiments with autologous blood lymphocytes showed that cell-dependent suppression was one mechanism of the low response of bronchial lymphocytes. In the patient who inhaled a foreign body, a proliferative response to antigens was restricted to bronchus-associated lymphoid tissue lymphocytes, suggesting a recruitment of antigen-reactive cells from a circulating pool.

Antigens, Viral↗
PubMed1977

Determinants of transmembrane bicarbonate flux during acid-base changes.

Experiments were designed to determine the contribution of increased extracellular HCO3- concentration, [HCO-3e], to the net extracellular-to-intracellular HCO3- flux observed in hearts during hypercapnia. Isolated rabbit hearts were perfused by recirculating for 15-min periods a small volume of Ringer solution in which [HCO-3e] and carbon dioxide tension (PCO2) could be independently altered. A net HCO-3 flux was evidenced by a decrease in [HCO-3e] during recirculation. [HCO-3e] was randomly increased from 19 mM over a range of 19-42 mM at a constant PCO2 of 38.7 Torr. The resulting flux increased linearly with the [HCO-3e] existing at the start of recirculation. The same relationship was observed at 95.8 Torr PCO2. The disappearance of HCO-3 from the perfusate could not be explained by dilution in the interstitium or by lactate accumulation. When PCO2 was increased from 40 Torr over a range of 40-160 Torr at a constant [HCO-3e] of 20 or 30 mM, a small flux was observed only at the highest PCO2 levels. Essentially the same results were obtained when recirculation time was prolonged to 30 min. These results suggest that the major determinant of the HCO-3 flux is a change in extracellular HCO-3 concentration.

Acid-Base Equilibrium↗
PubMed1977

Contribution of a net transmembrane HCO3- flux to intracellular acid-base regulation.

Experiments were performed to determine the relative effects of a net extracellular-to-intracellular HCO3- flux and of elevated carbon dioxide tension (PCO2) on cellular acid-base regulation. Isolated rabbit hearts were perfused by recirculating a small volume of Ringer solution in which the PCO2 and the HCO3- concentration could be independently altered. Net HCO3- flux was assessed by the disappearance of HCO3- from perfusate. Between 40 and 100 Torr PCO2, a HCO3- flux into the cell occurs only when perfusate HCO3- concentration is increased. Therefore, by selective manipulation of perfusate HCO3- and PCO2 it is possible to induce hypercapnia with or without an accompanying HCO3- flux. When perfusate HCO3- concentration was increased from 20 to 36 mM, cellular HCO3- concentration increased from 22.5 +/- 0.8 to 26.1 +/- 1.0 mM at 40 Torr PCO2 and from 27.8 +/- 0.7 to 34.1 +/- 1.4 mM at 98 Torr PCO2. These increases can be accounted for by the amount of HCO3- that disappeared from the perfusate. The results suggest that most of the initial cell CO2 buffering is provided by the net HCO3- flux in addition to the passive physicochemical buffering.

Acid-Base Equilibrium↗
PubMed1976

An approach to immunotherapy using antibody to IgE in mast cell leukemia.

Passive immunotherapy was attempted in a patient with mast cell leukemia using antibody against IgE. The results of both in vitro and in vivo studies indicate that although receptor sites for IgE were retained by the malignant mast cell, a secretory defect was present characterized by the spontaneous release of histamine and an impaired secretory response to anti-IgE antibody. Anti-IgE antibody selectively and reproducibly reduced the number of circulating mast cells probably by facilitating their permanent uptake by the reticuloendothelial system. Tolerance was not achieved with high dose deaggregated sheep IgG, nor were we able to confirm the effectivity of immunochemotherapy based on linking chlorambucil to antibody directed against the tumor-associated "antigen" IgE.

Animals↗
PubMed1976

Cardiac and skeletal muscle acid-base composition during metabolic acidosis in dogs.

Nephrectomized, open chested dogs were infused with 25-30 ml.kg(-1) body weight of 0.15 M NaCl (group I), 0.15 MHCl (Group II) or 0.3 M lactic acid (Group) III). Pulmonary ventilation was maintained constant in the three groups. Intracellular pH was calculated with the CO2 method. No significant intracellular or extracellular acid-base changes were produced in Group I. A similar degree of extracellular acidosis was achieved in Groups II and III. In spite of constant arterial PCO2, the PCO2 of mixed, coronary sinus and femoral vanous blood increased moderately after the infusion in Groups II and III. It was calculated that less than half of the HCl acid infused remained in the extracellular space. However, no significant changes were observed in the acid-base composition of skeletal muscle in either Group II or III. Comparison of the cardiac muscle cell acid-base composition of Group I with that of Groups II and III whows that metabolic acidosis of the degree and duration produced in these experiments does not produce appreciable myocardial acidosis.

Acid-Base Equilibrium↗
PubMed1976

Cell mediated immunity to corn starch in starch-induced granulomatous peritonitis.

Two patients with histologically diagnosed starch induced granulomatous peritonitis (SGP) have been shown to have cell mediated immunity to corn starch using the techniques of macrophage migration inhibition and lymphocyte DNA synthesis. Control groups of normal subjects, patients with uncomplicated laparotomy, and patients with Crohn's disease were negative in both tests. Lymphocytes from two patients with band adhesions, one of whom had biopsy evidence of a granulomatous reaction to starch, were sensitized to starch. Cell mediated immunity to starch may contribute to the pathogenesis of SGP, and some band adhesions may be a chronic low grade manifestation of this disorder.

Adolescent↗
PubMed1976

Myocardial CO2 buffering: role of transmembrane transport of H+ or HCO3-ions.

Isolated rabbit hearts were perfused with rabbit red cells suspended in Ringer solution. A small volume of perfusate was recirculated for 10 min at Pco2 of 33.4 +/- 0.9 or 150.8 +/- 7.5 mmHg. Hypercapnia resulted in an increase in perfusate HCO3- concentration that was smaller than that observed when isolated perfusate was equilibrated in vitro with the same CO2 tensions (delta HCO-3e = 1.6 mM, P less than 0.01). This difference is consistent with a net movement of HCO3- into or H+ out of the mycardial cell, and cannot be accounted for by dilution of HCO3- in the myocardial interstitium. Recirculation of perfusate through the coronary circulation at normal Pco2 for two consecutive 10-min periods was not followed by changes in perfusate HCO3- concentration. A high degree of correlation (r = 0.81) was observed between intracellular HCO-3e concentration and the corresponding delta HCO-3e in individual experiments. The results suggest that transmembrane exchange of H+ or HCO3- is a buffer mechanism for CO2 in the myocardial cell.

Animals↗
PubMed1976

Effect of beta-adrenoreceptor blockade on rat cardiac and skeletal muscle pH.

The effect of catecholamines on the intracellular pH of rat cardiac and skeletal muscle during varying extracellular acid-base states was determined. Intracellualr pH (pHi) was calculated from the distribution of [14C]DMO. Acid-base disturbances were produced by placing the animals in an environmental chamber containing 10 or 20% CO2 or by administering HCL or NaHCO3. Two hours later the animals were anesthetized with sodium pentobarbital and blood and tissue samples obtained. In one series of animals, the effects of catecholamines were attenuated by administering the beta-adrenoreceptor antagonist MJ 1999 (Sotalol). In animals breathing 20% CO2, cardiac muscle pH was lower in beta-blocked than unblocked animals (6.69 vs. 6.78). During metabolic acidosis, cardiac muscle pH of beta-blocked animals was lower than that of unblocked animals (6.75 vs. 6.84). The same relationship was observed for skeletal muscle during metabolic acidosis-beta blockade pHi, 6.66; unblocked pHi, 6.77. The pHi of beta-blocked versus unblocked animals was not significantly different under normal acid-base conditions or metabolic alkalosis for cardiac or skeletal muscle. The effective buffer value of both tissue over the normal acidotic range was decreased by the beta-blocking agent. These results indicate that catecholamine release accompanying acidosis attenuates the change in pHI and increases the effective buffer value of cardiac and skeletal muscle.

Acid-Base Imbalance↗
PubMed1975

Isolation and characterization of an aetiological agent in Whipple's disease.

A cell wall deficient form of an alpha-haemolytic streptococcus was grown from a prolonged monolayer cell culture of a lymph node taken from a patient with Whipple's disease. Serological cross reactivity was shown between the organism and the material within Whipple's disease macrophages positive for diastase-resistant periodic acid-Schiff (D./P.A.S.). In vitro studies characterized the organism as a facultative intracellular parasite which caused the accumulation within cells of D./P.A.S.-positive material. These results suggest that a pathogenic bacterium is the essential aetiological agent and that the culture of Whipple's disease tissues in hypertonic media may have practical value.

Adult↗