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R L Walsh

Publications and source records attributed to R L Walsh.

15 recordsLinked to original sources
PubMed1992

A rapid procedure for the measurement of elastase inhibitory function of plasma and bronchoalveolar lavage fluid.

We describe a method to measure human leukocyte elastase (HLE) inhibitory capacity and compared it with porcine pancreatic elastase (PPE) inhibitory capacity and with a turbidimetric method using a specific antibody to alpha-1 antitrypsin (AAT), all performed on a Cobas Bio centrifugal analyser. This assay used methoxysuccinyl-dialanine-proline-valine-p-nitroanilide as substrate in the presence of 0.01% Brij 35, an HLE enzyme activator. Samples containing commonly used anti-coagulants and serum could be used in the assay, except for those containing heparin which strongly inhibited HLE. This assay was used to determine the functional AAT concentrations in plasma from a number of normal volunteers and patient groups, and was compared to the immuno-turbidimetric AAT assay. No difference in the proportion of functional to immuno-turbidimetric AAT was noted between any of the groups studied except for the adult respiratory distress syndrome (ARDS), where this percentage was reduced (p less than 0.05). An increase in both immuno-turbidimetric and functional AAT was seen for children (both p less than 0.01), in emphysema (p less than 0.05 and p less than 0.01 respectively) and ARDS (both p less than 0.05) when compared to adult non-smokers. This assay was also used to determine the HLE inhibitory capacity of serum and bronchoalveolar lavage (BAL) fluid from normal volunteer smokers (n = 4) and non-smokers (n = 4), and in the serum and BAL fluid from patients with ARDS (n = 5). Serum AAT was 94% functional in non-smokers (91% with PPE functional assay) and 96% in smokers (97% with PPE assay).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Plasma elastin-derived peptide levels in normal adults, children, and emphysematous subjects. Physiologic and computed tomographic scan correlates.

Pulmonary emphysema is likely to be the result of elastic tissue digestion by unrestrained elastase activity in the lung. Elastin breakdown by elastases results in the release of soluble elastin fragments (EDP), which may be measured in plasma by an ELISA. Plasma EDP levels measured using an ELISA were determined in the following groups: disease-free children (n = 24), 0.162 +/- 0.082 ng/ml; disease-free adult nonsmokers (n = 114), 1.74 +/- 0.8 ng/ml; smokers (n = 68), 2.76 +/- 4.59 ng/ml; reformed smokers (n = 43), 1.91 +/- 1.14 ng/ml. Adults with established pulmonary emphysema (n = 50), as defined by bullous formation on the chest radiograph, had levels of 50.83 +/- 24.8 ng/ml, significantly higher than the disease-free groups at p < 0.01. Pulmonary emphysema can be reflected by pulmonary function tests, especially those that measure the pulmonary elastic properties, and by computed tomographic (CT) scan percent emphysema score. We therefore examined the relationship of plasma EDP to these other indicators of pulmonary emphysema in a separate group of 26 subjects using elastic recoil measurements (K), and a further group of 30 subjects with CT scan percent emphysema score. A significant correlation of p < 0.001 was shown for plasma EDP and K and a significant correlation of p < 0.01 was shown for plasma EDP and CT scan percent emphysema score, these correlations suggesting that plasma EDP levels are indicators of the loss of pulmonary distensibility and of mild to moderate pulmonary emphysema. These findings suggest that pulmonary emphysema is characterized by active elastin breakdown.

Adult↗
PubMed1991

Heparin and heparan sulphate are inhibitors of human leucocyte elastase.

1. Heparin and heparan sulphate strongly inhibited human leucocyte elastase activity in an automated assay using the soluble substrate, n-succinyl-(L-alanine)3-p-nitroanilide (50% inhibition of 250 microliters of 10 micrograms of human leucocyte elastase/ml was obtained with 80 microliters of 2.8 micrograms of heparin/ml and 8 micrograms of heparan sulphate/ml). Less significant inhibition at the same concentrations was seen with the other glycosaminoglycans tested: hyaluronic acid and chondroitin sulphates A-C. 2. Heparin and heparan sulphate also strongly inhibited human leucocyte elastase activity towards insoluble human lung elastin, as determined by an e.l.i.s.a. for soluble elastin-derived peptides released by elastolytic activity on the elastin. This inhibition was shown not to be due to a direct interference of the glycosaminoglycans in the e.l.i.s.a. nor to the inhibition causing a change in the size of the elastin-derived peptides. However, unlike the chromogenic assay with n-succinyl-(L-alanine)3-p-nitroanilide as substrate, where heparin was the more effective inhibitor, in this assay system heparan sulphate was the more effective inhibitor (50% inhibition of 100 microliters of 50 ng of human leucocyte elastase/ml was obtained with 100 microliters of 4.5 micrograms of heparin/ml and 0.8 microgram of heparan sulphate/ml). These results suggest that heparin and heparan sulphate, as components of cellular and basement membranes, are likely to have a role in protecting structural proteins, such as elastin, from the proteolytic activity of human leucocyte elastase.(ABSTRACT TRUNCATED AT 250 WORDS)

Cells, Cultured↗
PubMed1986

Lyme carditis. Electrophysiologic and histopathologic study.

To further define the nature of Lyme carditis, electrophysiologic study and endomyocardial biopsy were performed in a patient with Lyme disease, whose principal cardiac manifestation was high-degree atrioventricular block. Intracardiac recording demonstrated supra-Hisian block and complete absence of an escape mechanism. Gallium 67 scanning demonstrated myocardial uptake, and right ventricular endomyocardial biopsy revealed active lymphocytic myocarditis. A structure compatible with a spirochetal organism was demonstrated in one biopsy specimen. It is concluded that Lyme disease can produce active myocarditis, as suggested by gallium 67 imaging and confirmed by endomyocardial biopsy. Furthermore, the presence of high-grade atrioventricular block in this disease requires aggressive management with temporary pacemaker and corticosteroid therapy.

Adult↗
PubMed1985

Autonomic dysfunction and Eaton Lambert syndrome.

Autonomic dysfunction associated with Eaton Lambert syndrome in a patient with oat cell carcinoma of the lung is reported. Widespread postganglionic adrenergic and cholinergic defects suggested the presence of autonomic neuropathy. Clinical remission accompanied tumor regression after combined chemotherapy and radiation.

Autonomic Nervous System↗
PubMed1985

Bronchoalveolar lavage.

Bronchoalveolar lavage (BAL) is a relatively new technique for assessment of the alveolar compartment of the lung. Its current clinical applications are the initial assessment of acute and chronic diffuse interstitial lung disease and the diagnosis of pulmonary infections, especially in the immunocompromised host. In addition, BAL provides information on the pathophysiology of diffuse interstitial lung disease. Future studies of BAL fluids should confirm its use in the prognostic assessment of diffuse interstitial lung diseases and in the assessment of effects of therapy.

History, 20th Century↗
PubMed1983

Albumin I.M.V.S.: a variant detected by a Bromcresol Green dye binding method.

A unique variant of human albumin was discovered in a family following routine multiple biochemical analysis. Their sera demonstrated increased Bromcresol Green (BCG) dye binding under certain reaction conditions (excess amounts of the detergent Pegosperse in the presence of Merthiolate). This effect was also seen with a structurally similar dye, Bromcresol Purple (BCP). The variant sera also showed an altered pattern of BCG dye binding (in the presence of Merthiolate and excess Pegosperse) compared to normal sera when the temperature or the pH of the dye reagent was changed. Decreased binding of the dye 2-(4'-hydroxybenzeneazo)benzoic acid (HABA) was also noted. Similar findings were observed in six other patients over a period of 21 months. Column chromatography of the variant sera on a DEAE-Sepharose column separated the albumin into two fractions, one showing normal dye binding properties, the other showing the more extreme pattern of dye binding seen for the whole variant serum.

Autoanalysis↗
PubMed1983

A comparison of dye binding methods for albumin determination: the effects of abnormal sera, reaction times, acute phase reactants and albumin standards.

Four bromcresol green methods were evaluated, three of which were used with a reaction time of 15 seconds. An immunonephelometric assay and a bromcresol purple method were used as comparison methods. The bromcresol purple method agreed well with the more specific immunonephelometric procedure. Forty-seven human sera, thirty with low albumin concentrations and seventeen with high albumin concentrations were used in each assessment. The best bromcresol green methods were those using low dye and surfactant (Brij-35) concentrations and the shortest possible reaction times. Except in one bromcresol green method with a long reaction time of 10 minutes, there was no significant difference in values overall between sera having a low albumin concentration with either raised or normal acute phase reactants. Comparable results were obtained using standards of human and bovine albumin preparations in bromcresol green methods but not in the bromcresol purple method.

Bromcresol Green↗
PubMed1980

Binding of IgG and other proteins to microfilters.

We evaluated 10 microfilters for their ability to filter diluted sera without removing immunoglobulins (Ig) G, A, and M, albumin, and transferrin. In general, filters containing cellulose nitrate remove IgG from solution, the amount adsorbed being proportional to the IgG concentration in the solution. With some sera we noted IgA and IgM adsorption to cellulose-nitrate-containing filters, but there was no significant adsorption of albumin or transferrin to any of the filters. We also found that cellulose-nitrate filters adsorbed IgG from antiserum, with consequent loss of titre as seen in a nephelometric assay. Adsorption of IgG was not seen if the filters were prewashed with polyethylene glycol or if the antisera contained polyethylene glycol. With a sufficiently large antibody excess in the nephelometric assay, this loss of titre through filtration becomes undetectable.

Adsorption↗
PubMed1979

Evaluation of two commercially available laser nephelometers and their recommended methods for measurement of serum immunoglobulin G.

The Hyland and Behring laser nephelometer systems for assay of specific proteins are described. Immunoglobulin G was measured to assess the overall performance of the two systems. Intra-batch precision figures were comparable to those for the radial immunodiffusion method run routinely in our laboratory. There was no significant interference from turbid or lipemic specimens. Accuracy, ease of instrument operation, standard curve stability, linearity, and accessory equipment are discussed. Immunoglobulin G is measured rapidly, accurately, and precisely by either system.

Humans↗