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Biomedical subjects

R L Clancy

Publications and source records attributed to R L Clancy.

At least 19 recordsLinked to original sources
PubMed1992

Measurement of lysozyme by an enzyme-linked immunosorbent assay.

In this study an enzyme-linked immunosorbent assay has been developed for the determination of lysozyme in saliva, serum and urine. The assay relies on the detection of specific protein rather than lytic activity, a property which has been shown to be most suitable for the quantitation of lysozyme in mucin containing substances. Our results indicate that no pretreatment is necessary for the immunochemical method. The assay is sensitive to concentrations as low as 1 microgram lysozyme/l. The intra-assay and inter-assay coefficients of variation were 5.9% and 15.8% respectively. The lysozyme level in whole saliva was 55.53 +/- 30.35 mg/l, in serum the level was 0.64 +/- 0.15 mg/l and in urine it was 0.17 +/- 0.22 mg/l. Comparisons between immunochemical determination and lytic assays showed a good correlation (serum, r = 0.79, P less than 0.01; saliva, r = 0.85, P less than 0.005; treated saliva, r = 0.96, P less than 0.001).

Adult↗
PubMed1992

Mechanism of the effect of alkalosis on maximum oxygen uptake in hypoxic exercise.

Maximum oxygen uptake (VO2max) of rats is increased in alkalosis; this increase is larger in hypoxic than in normoxic exercise (Gonzalez et al. (1991b). J. Appl. Physiol., 71: 1050-1056). The objective of the present experiments was to determine the mechanism of this phenomenon. NaHCO3 (0.3 M, 9 mmol/kg) was given 15 min before exercise to rats acclimated to PB 380 Torr for 3 weeks (HxBic) and to normoxic rats (NxBic). Additional groups of acclimated and normoxic rats received 0.3 M NaCl (HxNaCl and NxNaCl, respectively). Hx rats exercised at PIO2 approximately 70 Torr; Nx rats at PIO2 approximately 140 Torr. VO2max was higher after NaHCO3 than after NaCl; this effect was larger in hypoxia. The increase in VO2max was mediated through an increased arterio-venous oxygen concentration difference ((Ca - Cv)O2), due, in turn, to a higher CaO2 without changes in CvO2. (Ca - Cv)O2 after NaHCO3 was larger in hypoxia because a change in pH results in a larger change in HbO2 saturation at the values prevalent in arterial blood of the hypoxic rats (i.e. PO2 approximately 40-50 Torr, SO2 50-60%), than at either the values of normoxic arterial blood or of venous blood during maximum exercise. These results suggest that an increase in hemoglobin-oxygen affinity improves oxygen uptake in the lungs during hypoxia, without hindering its release in the tissues, and therefore has a beneficial effect in hypoxic exercise.

Acid-Base Equilibrium↗
PubMed1992

Biotypes of Haemophilus parainfluenzae from the respiratory secretions in chronic bronchitis.

A total of 2401 isolates of Haemophilus parainfluenzae was isolated from respiratory secretions of 36 healthy adults and 128 patients with chronic bronchitis over a period of 1 year. The isolates were allocated to eight biotypes, by their production of indole, urease and ornithine decarboxylase. Biotypes I and II constituted most of the isolates of H. parainfluenzae from the oropharynx of controls (75%) and chronic bronchitics (c. 90%). Among the patients, there was no difference in the isolation rate between oropharyngeal swabs and sputum specimens. Biotypes III, IV, VI, VII and VIII were isolated less frequently, as was a new taxon defined here as biotype V which does not produce indole, urease or ornithine decarboxylase. Biotype III was isolated significantly less frequently from cases of chronic bronchitis than from controls, whereas biotype II was isolated somewhat more frequently from the patients, especially during acute episodes.

Adult↗
PubMed1992

A novel particulate influenza vaccine induces long-term and broad-based immunity in mice after oral immunization.

The immunogenicity of a novel particulate oral influenza vaccine was examined in terms of antibody response and protection in mice. Oral immunization with chicken erythrocytes (CRBC) adsorbed with gamma-irradiated influenza A virus induced high levels of immunoglobulin G antibodies and protection in the lung compared with gamma-irradiated virus administered alone or CRBC. Immunoglobulin A antibodies were the predominant antibodies in nasal washings, and their presence did not correlate with protection as well as immunoglobulin G antibodies. Immunity was not specific for the immunizing virus subtype, as antibodies and enhanced lung clearance of virus were demonstrated with different virus subtypes. However, mice were not protected when challenged with live influenza B virus. The antibody response and the degree of protection were dependent on both the concentration of virus adsorbed to CRBC and number of CRBC adsorbed to virus. Virus-adsorbed CRBC given subcutaneously failed to induce antibodies or protection. Oral immunization with A/Qld/6/72 (H3N2) virus gave a high level of protection over 12 weeks, which could be demonstrated with different subtypes. Protection correlated with antibody levels in the lung determined by both enzyme-linked immunosorbent and hemagglutination inhibition assays, although the levels detected by the latter declined over time.

Animals↗
PubMed1991

Maximum oxygen uptake and arterial blood oxygenation during hypoxic exercise in rats.

The objectives of these experiments were 1) to describe the effect of maximum treadmill exercise on gas exchange, arterial blood gases, and arterial blood oxygenation in rats acclimated for 3 wk to simulated altitude (SA, barometric pressure 370-380 Torr) and 2) to determine the contribution of acid-base changes to the changes in arterial blood oxygenation of hypoxic exercise. Maximum O2 uptake (VO2max) was measured in four groups of rats: 1) normoxic controls run in normoxia (Nx), 2) normoxic controls run in acute hypoxia [AHx inspiratory PO2 (PIO2) approximately 70 Torr], 3) SA rats run in hypoxia (3WHx, PIO2 approximately 70 Torr), and 4) SA rats run in normoxia (ANx). VO2max (ml STPD.min-1.kg-1) was 70.8 +/- 0.9 in Nx, 46.4 +/- 1.9 in AHx, 52.6 +/- 1.1 in 3WHx, and 70.0 +/- 2.4 in ANx. Exercise resulted in acidosis, hypocapnia, and elevated blood lactate in all groups. Although blood lactate increased less in 3WHx and ANx, pH was the same or lower than in Nx and AHx, reflecting the low buffer capacity of SA. In AHx and 3WHx, arterial PO2 increased with exercise; however, O2 saturation of hemoglobin in arterial blood (SaO2) decreased. In vitro measurements of the Bohr shift suggest that SaO2 decreased as a result of a decrease in hemoglobin O2 affinity. The data indicate that several features of hypoxic exercise in this model are similar to those seen in humans, with the exception of the mechanism of decrease in SaO2, which, in humans, appears to be due to incomplete alveolar-capillary equilibration.

Acclimatization↗
PubMed1991

Effect of alkalosis on maximum oxygen uptake in rats acclimated to simulated altitude.

The objective of the present experiments was to determine whether prevention or moderation of exercise acidosis would influence arterial blood oxygenation and exercise capacity in hypoxia. The effect of administration of 0.3 M NaHCO3 (3 ml/100 g) on maximum O2 uptake (VO2max) and arterial blood oxygenation was determined in rats acclimated to simulated altitude (370-380 Torr barometric pressure) for 3 wk (HxBic) and in normoxic littermates (NxBic). Controls were simulated-altitude (HxNaCl) and normoxic rats (NxNaCl) given 0.3 M NaCl. Inspiratory PO2 during treadmill exercise was approximately 70 Torr for hypoxic rats and 140-145 Torr for normoxic rats. VO2max was 18% higher in HxBic than in HxNaCl (62.8 + 1.6 vs. 53.1 + 1.0 ml STPD.min-1.kg-1, respectively, P less than 0.05) and only 8% higher in NxBic than in NxNaCl (74.0 + 1.1 vs. 68.7 + 1.5 ml STPD.min-1.kg-1, respectively, P less than 0.05). Exercise in HxNaCl resulted in a decrease in arterial O2 concentration (CaO2), which was largely due to a pH-induced decrease in O2 saturation of arterial blood, and occurred despite an increase in arterial PO2. NaHCO3 moderated the acidosis of exercise and largely attenuated the decrease in CaO2. The effects of acidosis and bicarbonate on CaO2 were much less evident in the normoxic controls. There was an almost linear relationship between VO2max and the corresponding CaO2 for all four groups, suggesting that the effect of NaHCO3 on VO2max may be related to moderation of the decrease in CaO2.

Acclimatization↗
PubMed1991

Cellular electrolyte and volume changes induced by acidosis in the rabbit proximal straight tubule.

Cellular acidosis induced either by high Pco2 or by low HCO3- concentrations has been shown to cause cell swelling in isolated, lumen-collapsed, S2 segments of the rabbit proximal tubule (Sullivan et al., Am J Physiol 1990; 258: F831-F839). The swelling is not followed by a volume regulatory response. The ionic basis of the swelling has been investigated by measurement of the cellular K+, Na+, and Cl- content (electron probe) and HCO3- concentration (pH-sensitive fluorescent dye). Cell content of K+, Na+, and Cl- was expressed as a ratio to P content. Exposure to 15% CO2 increased K/P from 0.98 to 1.16, Cl/P from 0.14 to 0.20, and Na/P from 0.09 to 0.11. Cell (HCO3-) increased from 22 to 32 mM. Reduction in bath (HCO3-) from 25 to 5 mM reduced cell (HCO3-) from 24 to 8 mM and increased K/P from 0.75 to 0.90. Na/P fell from 0.13 to 0.09, and Cl/P fell from 0.15 to 0.12. Thus, swelling resulting from acidosis induced by high CO2 was accompanied by an accumulation of K+, Cl-, and HCO3-; that resulting from acidosis induced by a fall in (HCO3-) was combined with an accumulation of K+ and an unidentified anion. To determine if the swelling induced by a fall in pH might be coupled with depolarization of the basolateral membrane, the effect of 1 mM barium was tested. Barium caused cell volume to increase 10.2%. Cell pH rose from 7.38 to 7.56, K/P increased from 0.63 to 0.73, Na/P did not change, and Cl/P rose from 0.17 to 0.20. Cell (HCO3-) increased 10.4 mM. When the pH of the barium-treated tissue was reduced to 7.02 by raising Pco2, additional cell swelling and accumulation of K+ occurred. The effect on cell volume of a reduction of bath (HCO3-) from 25 to 5 mM at constant bath pH was determined. Cell pH was not altered. Cell volume decreased 3% initially and then returned to the control level. When the bath (HCO3-) was restored to 25 mM, cell volume increased 3.9% and then returned to the baseline. Thus, volume regulation was not impaired. It was concluded that a fall in cell pH induces swelling, and this is coupled with an accumulation of K+. This is probably the result of a pH effect on barium-sensitive and barium-insensitive K+ conductance pathways. The nature of the anions that balance the gain in K+ depends on the means used to induce acidosis.

Acidosis, Renal Tubular↗
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↗