Acid-base characteristics of steady-state exercise in rats adapted to simulated altitude.
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Acclimatization↗
Biomedical subjects
R L Clancy
Publications and source records attributed to R L Clancy.
Inhibition of adhesion of Haemophilus influenzae to buccal cells by respiratory secretions.
The ability of salivary secretions and sputum sol from patients with chronic bronchitis to inhibit the adhesion of non-serotypable Haemophilus influenzae to human buccal epithelial cells has been examined. Specific H. influenzae antibodies were measured by an enzyme-linked immunosorbent assay (ELISA). Saliva and sputum levels of anti-H. influenzae immunoglobulin A (IgA) antibody were related inversely to buccal cell adherence (r = -0.92). Absorption of saliva and sputum sol with H. influenzae removed antibody detected by ELISA but only partially removed inhibition of attachment of bacteria. In patients with a history of recurrent bronchitis significantly more inhibitory activity remained after absorption of the secretory IgA (sIgA) specific antibody compared with patients who were resistant to acute episodes of infection (P less than 0.05). These observations suggest that factors, other than sIgA, are present in respiratory secretions and are capable of modulating H. influenzae attachment to buccal epithelial cells.
Adult↗
Bacterial colonisation of the respiratory tract in chronic bronchitis.
One hundred and nine subjects with chronic bronchitis were studied prior to winter and without clinical infection, to determine baseline patterns of bacterial colonisation. Qualitative analysis of cultures of oropharyngeal swabs showed little difference from age matched normal controls (17) except for growth of small numbers of Gram negative coliforms in the chronic bronchitic group. Quantitation of bacteria colonising the oropharynx showed small numbers (mean of 10(5) cfu/ml), with no particular bacteria dominating. Haemophilus influenzae was present in 7.3% of throat swabs from chronic bronchitic patients, but the organism was always less than 10% of the total count. Quantitation of bacteria in sputum showed significantly higher numbers (mean 10(7) cfu/ml). H. influenzae was detected in 25.7% of available specimens, and when present constituted greater than 90% of the total count. Biotyping of H. influenzae isolates demonstrated a separate colonisation of the upper and lower respiratory tracts.
Aged↗
Effect of cellular acidosis on cell volume in S2 segments of renal proximal tubules.
The presence of pH-sensitive transport mechanisms in the basolateral membrane of proximal tubular cells suggests that cell volume and its regulation may be sensitive to changes in cell pH. We have measured the response of cell pH and cell volume to changes in the acid-base composition of solutions bathing isolated, lumen-collapsed, proximal S2 tubular segments taken from the rabbit kidney. Cell pH was determined by measurement of the fluorescence emission of 2',7'-bis(carboxyethyl)-5(6)-carboxyfluorescein. Cell volume was calculated from measurements of tubular diameter. An increase in CO2 from 5 to 15% reduced cell pH 0.30 units and raised cell bicarbonate concentration ([HCO3]) 10 mM. Cell volume rose to 108.6% of control in 4 min. A decrease in bath [HCO3] from 25 to 5 mM reduced cell pH 0.41 units and cell [HCO3] by 15 mM. Cell volume gradually increased to 105.7% at 8 min. The rate of the regulatory volume decrease after cell swelling on exposure to a 160 mosM solution was determined in the presence of 5 and 15% CO2. The latter reduced the maximum fractional rate of recovery of volume from 0.18 to 0.11 min-1 but did not affect the extent of regulation. We conclude that acidosis causes cell swelling and reduces the rate of volume regulation in response to hypotonic media.
Acidosis↗
Compensation of respiratory alkalosis induced after acclimation to simulated altitude.
Conscious intact rats previously acclimated for 3 wk to barometric pressure of 370-380 Torr (3WHx) were made alkalotic for 3 h by a decrease in inspired O2 fraction from 0.10 to 0.075 at ambient barometric pressure (730-740 Torr). Controls were normoxic littermates (Nx) in which inspired O2 fraction was lowered from approximately 0.21 to 0.10 for 3 h. Arterial PCO2 decreased progressively and similarly in both groups (65-70% of control at 15 min). Initially, arterial pH increased less in 3WHx (0.09 +/- 0.004 vs. 0.15 +/- 0.008). As hypocapnia continued, delta[HCO3-]/delta pH (mmol.l-1.pH) became more negative in Nx, from -15.2 +/- 2.5 at 15 min to -37.0 +/- 2.9 at 3 h, indicating nonrespiratory compensation of alkalosis. In 3WHx, delta[HCO3-]/delta pH did not change during alkalosis. Cumulative renal excretion of base (mueq/100 g) during alkalosis increased by 73.2 +/- 11.1 in Nx and 25.4 +/- 7.3 in 3WHx. This difference was mainly due to a larger increase in HCO3- excretion in Nx. The data suggest that the smaller compensation of hypocapnic alkalosis in 3WHx is partly due to the smaller increase in renal base excretion. Because base availability limits renal base excretion, the smaller renal response of 3WHx may be secondary to the low plasma HCO3- concentration that accompanies altitude acclimation.
Acid-Base Equilibrium↗
Evaluation of a selective medium for the isolation and differentiation of Haemophilus influenzae and Haemophilus parainfluenzae from the respiratory tract of chronic bronchitics.
Respiratory tract specimens from chronic bronchitic patients were cultured for Haemophilus species on conventional chocolate agar and a modified sucrose medium in order to determine the accuracy of the new medium in differentiating Haemophilus influenzae from Haemophilus parainfluenzae strains. Haemophilus influenzae biotypes II and III and Haemophilus parainfluenzae biotypes I and II were found to be the predominant strains isolated from the respiratory tract. The modified sucrose medium was found to be a rapid and reliable means of differentiating Haemophilus influenzae from Haemophilus parainfluenzae by sucrose fermentation, on initial isolation.
Bronchitis↗
Protection induced against acute bronchitis--the use of human and rat models to determine mechanisms of action of oral immunization with Haemophilus influenzae.
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Acute Disease↗
Molecular characteristics of IgA in infant saliva.
Saliva was collected from 57 infants aged 6 weeks to 2.5 years and the molecular form of IgA was studied by centrifugation on sucrose density gradients. Two distinct populations were identified. Seventy-two per cent of the children had secretory IgA in their salivary secretions, while 28% had a molecular form corresponding to monomeric IgA. No samples with concurrent monomeric and secretory forms were detected. Monomeric IgA was not detected in any infant over 12 months of age. Secretory component was detected in all samples but was not associated with monomeric IgA. Forty-seven per cent of the samples contained IgA fragments of approximately 40,600 molecular weight. The presence of fragments dominated in the group of children with monomeric IgA. The presence of monomeric IgA in infant saliva did not result from degradation due to storage or proteolysis. The study demonstrated an apparent maturation sequence in the molecular form of IgA present in the salivary secretions of infants.
Adult↗
An animal model demonstration of enhanced clearance of nontypable Haemophilus influenzae from the respiratory tract after antigen stimulation of gut-associated lymphoid tissue.
An animal model of the clearance of nontypable Haemophilus influenzae has been developed to determine both optimal immunization strategies for controlling colonization of the respiratory tract in patients with damaged airways and mechanisms of action of immune clearance. It was demonstrated that stimulation of gut-associated lymphoid tissue (GALT) (either by direct injection or by ingestion of antigen) followed by local administration of antigen into the bronchus was required to enhance clearance in this model. The primary effect of GALT immunization persisted for at least 6 wk; it was specific and could not be replaced by systemic immunization. Failure to stimulate locally in the bronchus was associated with protracted clearance. No clear correlation between local or systemic antibody and bacterial clearance was demonstrated; however, immunized rats were shown to have faster recruitment of phagocytic cells to the bronchial spaces, and these phagocytes had a higher activity state than cells harvested from nonimmunized animals. It is probable that bacterial clearance is accelerated in immunized animals due in part to factors mediating a change in the behavior of luminal phagocytes.
Animals↗
Appearance of IgG and IgA antibodies in human bile after tetanus toxoid immunization.
Humans immunized intramuscularly with one dose of tetanus toxoid exhibited IgG, and in some cases IgA antibody, in their bile as well as serum. Both isotypes appeared in bile transiently with titres declining after about day 10 for both classes. These kinetics resembled those of the serum IgA response but were markedly different to those for IgG antibody in serum. Measured IgG titres in bile were between 0.07 and 4.2% of those in paired sera, and IgA titres were between 6.8 and 124% of sera. Peak responses in bile, while generally of smaller size, exceeded those of paired sera when expressed as antibody/mg of IgG or IgA present. This calculation showed that during the peak response bile was up to nineteen-fold more abundant in IgG antibody than was serum taken at the same time, and up to forty-five-fold more for IgA. Enrichment of antibody in bile is not consistent with the Ig of bile being solely conferred by plasma, and may mean the involvement of local synthesis too. This study indicates that tetanus toxoid immunization of humans results in biliary antibody and raises the possibility of intra-hepatic antibody production for export to the intestinal tract in man.
Adolescent↗
Regulation of the acid-base balance during prolonged hypoxia: effects of respiratory and non-respiratory acidosis.
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Acid-Base Equilibrium↗
The effect of prolonged hypoxia on striated muscle pH regulation.
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Animals↗
Seasonal variation in non-specific bronchial reactivity: a study of wheat workers with a history of wheat associated asthma.
To investigate seasonal variation in non-specific bronchial reactivity in wheat workers, we carried out histamine inhalation tests in 29 workers (28 of them men) from a small farming community with symptoms of wheat associated asthma before, during and after the 1983-4 Australian wheat harvest season. Four were cigarette smokers, and the age range was 12-54 (mean (SD) 30 (10)) years. Twenty eight subjects were atopic (one positive skinprick test result in tests with 10 common antigens), 60% reacting to house dust mite and all to at least one of eight wheat antigens. Baseline spirometry gave normal results (mean FVC1 90% (SD 8%) predicted; FVC 91% (7%) predicted). Bronchial reactivity was tested by the method of Yan et al. The cumulative doses of histamine acid phosphate (up to 3.91 mumol) that caused a fall of 20% from baseline in FEV1 was determined (PD20) and expressed as the geometric mean. In the low exposure season, May 1983, nine subjects had a PD20 (mean 1.2, range 0.3-3.9 mumol). The number rose to 19 in the summer harvest season, December 1983 (mean 0.8, range 0.07-3.9 mumol) and returned to nine in the subsequent winter, July 1984 (mean 1.8, range 0.4-3.9 mumol). The change in the number of subjects with a PD20 was significant (p less than 0.01). Four additional subjects probably had increased bronchial reactivity in the harvest season: in two the post-saline FEV1 was too unstable to give them histamine challenge and in two the challenge was inadvertently discontinued prematurely. Baseline FEV1 and FVC fell by 8% between the first and second studies (p less than 0.001); values were intermediate in the third study (FEV1 3.74, 3.44, and 3.57; FVC 4.66, 4.28, and 4.41 litres respectively). Linear modelling analysis of log PD20, season, FEV1, FVC, age, seasonality of asthma symptoms and skin test data indicated that the harvest season was the only significant determinant of variation in log PD20. It is concluded that in these wheat workers there is a seasonal variation in bronchial reactivity that may reflect a response to allergens associated with grain.
Adolescent↗
Biotyping respiratory Haemophilus species with the microbact system.
The biochemical characteristics of 114 respiratory Haemophilus isolates were examined by the Minitek and Microbact systems. The Microbact system was easy to use and read, although some of the less important reactions (glucose and xylose) were difficult to interpret on occasions. On the basis of the 3 crucial reactions--indole production, ornithine decarboxylase and urease activity--discrepancies between the two systems were minor. Given careful standardization of techniques the Microbact system is a suitable alternative to established techniques for the biotyping of H. influenzae and H. parainfluenzae.
Bacterial Typing Techniques↗
Efficacy of oral immunization against non-typable Haemophilus influenzae in man.
An oral polybacterial vaccine containing 1.5 X 10(9) killed Haemophilus influenzae per tablet stimulated salivary IgA anti H. influenzae antibody compared to placebo control groups according to statistical analysis using parameter estimates for the logistic model of best fit. Significant antibody secretion could only be demonstrated when three-monthly courses were taken, and when the H. influenzae were combined in a polybacterial mix. This latter form of H. influenzae is functionally defined as adjuvenated. Increasing the immunising dose 60 fold in the absence of the non H. influenzae bacterial species did not stimulate a detectable increase in salivary antibody.
Administration, Oral↗
IgD in infant saliva.
The ontogeny patterns of IgD in saliva were studied prospectively in 27 healthy full-term infants. The concentrations and the proportion of samples with detectable levels of IgD were higher near birth. After 6 months of age IgD was rarely detected in saliva. There was an inverse association between the detection of IgD and IgA in saliva. There were no correlations between IgD and IgG or albumin. These observations support the theory that IgD synthesis and secretion at mucosal sites reflects a 'physiological' deficiency in IgA synthesis.
Child, Preschool↗
The development of IgA-specific antibodies to Escherichia coli O antigen in children.
One hundred and sixty-five infants were studied longitudinally from birth to 5 years of age. One hundred and twenty-three school-age children and 27 adults were examined cross-sectionally. Total salivary IgA levels and IgA antibodies against Escherichia coli O antigens were measured. Total IgA levels were low (less than 20 mg/l) from birth to 4 years of age. At 5 years of age there was a dramatic increase in the total IgA level (geometric mean = 100.7 mg/l), after which the levels fell to values similar to those observed in adults (adult geometric mean = 53.2 mg/l). Low levels of IgA-specific E. coli antibodies were observed for the first 4 years of life (less than 1.0 ELISA units). There was a gradual increase in specific antibodies between 5 and 9 years of age (geometric men at 9 years = 4.66 ELISA units) to levels similar to those observed in adults (adult geometric mean = 8.20 ELISA units). It is suggested that the patterns of development for these variables reflect a balance between antigenic exposure and immune control mechanisms.
Adolescent↗
Development of an immunoglobulin A-specific anti-Haemophilus influenzae antibody assay for detection of antibody in human mucosal secretions.
A micro-enzyme-linked immunosorbent assay for quantitation of immunoglobulin A-specific anti-Haemophilus influenzae antibody is described and characterized. It had a sensitivity of 27 ng/ml, which is appropriate to detect antibody levels in normal saliva. Specificity for H. influenzae was achieved with the H1H2 group of antigens. Absorption studies for a range of bacteria showed little cross-reactivity, with the exception of Pseudomonas aeruginosa. Absorption studies involving various antigen preparations obtained from H. influenzae indicated that the H1H2 antigen group included significant amounts of surface antigen. An analysis of saliva from normal subjects and patients with chronic obstructive lung disease showed significant differences in levels of antibody, highlighting the potential value of the assay.
Aged↗