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Biomedical subjects

H C Ryley

Publications and source records attributed to H C Ryley.

At least 37 records · Page 2Linked to original sources
PubMed1988

Neonatal screening for cystic fibrosis in Wales and the West Midlands: 1. Evaluation of immunoreactive trypsin test.

A study programme was set up in Wales and the West Midlands to evaluate serum immunoreactive trypsin screening for cystic fibrosis in neonates using blood spots collected for metabolic screening. By screening half the blood spots from each area, it was hoped to generate two comparable groups of fibrocystic children; those detected by screening and those not screened who would be diagnosed clinically. Over almost three years, more than 120,000 specimens were screened and 37 infants detected with cystic fibrosis. Four additional fibrocystic patients were missed on screening: two had negative immunoreactive trypsin values, of which one had meconium ileus, and two, although giving initial positive tests, were negative on follow up. Excluding infants known to be at risk, comparison of the numbers of children detected in the screened and unscreened groups showed more than a two-fold difference in favour of the screened group. There may be a large number of undiagnosed fibrocystic patients in the general population.

Clinical Enzyme Tests↗
PubMed1986

Haptoglobin-haemoglobin complex in human plasma inhibits endothelium dependent relaxation: evidence that endothelium derived relaxing factor acts as a local autocoid.

Endothelium dependent relaxation of isometrically mounted rabbit aortic strip preparations was rapidly inhibited by human plasma at dilutions down to 1:1000. Gel filtration and ion exchange chromatography were used to demonstrate that this inhibitory activity was present in fractions containing haptoglobin. Purified haptoglobin itself possessed no inhibitory action against endothelium dependent relaxation, but the haptoglobin-haemoglobin complex did, consistent with the documented ability of haemoglobin to inhibit this phenomenon. The concentration of haemoglobin normally bound to haptoglobin is sufficient to account for the inhibitory properties of human plasma. This suggests that endothelium derived relaxing factor exerts no downstream intravascular effect in vivo and thus that its physiological dilator role is that of a local autocoid acting on subjacent smooth muscle.

Animals↗
PubMed1983

The composition of a mucus glycoprotein from meconium of cystic fibrosis, healthy pre-term and full-term neonates.

A high molecular mass mucus glycoprotein fraction (molecular mass greater than 1 million) which is a major component of meconium mucin, has been isolated from individual specimens collected from 20 healthy full-term infants, 19 premature infants and 19 infants with proven cystic fibrosis. The mucus glycoprotein fraction isolated from cystic fibrosis meconium had a significantly lower saccharide content than that isolated from specimens from healthy full-term infants but had a similar composition to that isolated from meconium of premature infants, gestational age 28-32 weeks. The composition of the glycoprotein fraction from the meconium of infants, gestational age 32-36 weeks, lay between that from cystic fibrosis and full-term. There is therefore a change or 'maturation' of epithelial mucin during gestation and it is hypothesised that the cystic fibrosis genetic lesion affects the maturation of epithelial secretion, resulting in the abnormal exocrine secretion associated with the disease.

Carbohydrates↗
PubMed1982

The effect of secretory immunoglobulin A on the in-vitro adherence of the yeast Candida albicans to human oral epithelial cells.

Secretory immunoglobulin A (s-IgA) isolated from human breast milk inhibited the adherence of C. albicans to human oral epithelial cells. This inhibitory effect of s-IgA was maximal at 1 1/2 hours, it was concentration-dependent and was still detectable at subagglutinating antibody concentrations. The inhibitory action of s-IgA was due to its content of specific candidal antibody. Non-specifically bound s-IgA enhanced adherence of the yeast and presumably tends to impair the immune disposal of candida by specific antibody. The reduced adherence of candida pre-treated with 0.4 per cent formol saline at a concentration which kills the organism but leaves its surface antigens intact suggests that, although dead organisms may form an initial loose attachment to the epithelial surface, only viable organisms bind irreversibly. The specific-s-IgA appears to block surface sites on C. albicans involved in epithelial adherence but this action of s-IgA cannot be attributed solely to its agglutinating properties.

Candida albicans↗
PubMed1982

Screening for cystic fibrosis.

Practicable methods are now available for whole population screening of neonates for cystic fibrosis. Although diagnosis and treatment of the disease from birth has not yet been unequivocally shown to improve prognosis, existing evidence suggests that this is likely. Further ethical reasons are proposed in support of neonatal diagnosis and early treatment. The development of tests for prenatal diagnosis and carrier detection is under active investigation, and raises ethical problems for heterozygotes and their medical advisers. The heavy financial and emotional burden this disease imposes on the patient and the family should not be underestimated when policy decisions are made.

Cystic Fibrosis↗
PubMed1981

Distribution of non-plasma protein components in meconium from healthy and cystic fibrosis neonates.

The distribution of four antigens of alimentary tract origin was studied in meconium collected from healthy and cystic fibrosis (CF) neonates. Two antigens, carcinoembryonic antigen and a beta glycoprotein designated Mec 6, had significantly lower concentrations in the meconium from CF neonates compared with that from healthy full-term infants. As their concentrations were unrelated to whether or not the infants had had pancreatic insufficiency at birth, their measurement may be of value for screening. Their concentrations also depended on the gestational age of the newborn, and it is speculated that the CF lesion may affect the maturation of intestinal secretions.

Alkaline Phosphatase↗
PubMed1981

Assay of serum immunoreactive trypsin in dried blood spots and the early detection of cystic fibrosis.

Immunoreactive trypsin (IRT) content in blood spots from 17 cystic fibrosis (CF) children born between 1975-80 were assayed with reagents from two commercial radioimmunoassay kits. The manufacturers' procedures were modified to allow assay of blood spot IRT. Half of the CF samples had a significantly raised IRT content compared to normal blood spots. Of the blood spots from five children whose meconium screening gave negative results, three or five (depending on the kit used) had a raised IRT content. On the other hand, less than 50% of children initially detected by meconium screening had raised blood spot IRT values. In our hands, analysis of blood spots for IRT does not consistently identify the newborn with CF and offers no advantage over other screening methods.

Adult↗
PubMed1980

Tumour-necrosis factor from the rabbit. IV. Purification and chemical characterization.

Serum from rabbits with BCG/endotoxin-induced shock is growth inhibitory or cytotoxic to a range ot tumour cell lines. The active component, tumour-necrosis factor (TNF), has been purified 1000-fold by sequential salt precipitation, ion-exchange chromatography and gel-filtration. TNF had a mol. wt of 67,000 on gradient PAGE and 39,000 on Ultrogel AcA44 gel-filtration. The isoelectric point was pH 5.1-5.2. TNF was susceptible to the proteolytic enzyme pronase, but resistant to trypsin or papain. On isopycnic ultracentrifugation it had a buoyant density of 1.27, confirming that it is protein in nature, with little or no carbohydrate. This is also suggested by its failure to bind to a range of lectins.

Animals↗
PubMed1980

Composition of bronchopulmonary secretions from patients with bronchiectasis.

Pulmonary function tests were carried out on 17 patients with bronchiectasis and six indices were selected to grade severity. Average concentrations of nine plasma proteins were determined by quantitative immunoelectrophoresis in specimens of sputum and serum from each patients. Wide patient-to-patient variation in concentration was encountered which appeared to follow a continuous progression unrelated to clinical severity. Patients at the upper end of the scale appeared to be responding by exudation and a pulmonary hypersensitivity reaction may be occurring in their lungs. There was evidence of selective concentration in sputum of alpha 1-antichymotrypsin and IgA although IgA concentrations were lower than would be expected in patients with chronic bronchitis. It is suggested that sputum IgA levels could be explored as a diagnostic criterion in those patients who could equally be suffering from chronic bronchitis.

Adult↗
PubMed1979

Screening for cystic fibrosis in the newborn by meconium analysis.

During a 4-year routine screening programme for cystic fibrosis (CF) 15 464 specimens were examined for raised meconium albumin levels by a test strip method and by electroimmunoassay. The incidence of false-positive results was about 5 per 1000 specimens in either test. This could be reduced by 90% by determining the ratio of albumin : alpha-1-trypsin inhibitor (a ratio below 2.0 being considered as a negative result), and it could be reduced to zero by determining the ratio in subsequent faecal specimens. Three of 12 meconium specimens from infants with proved CF gave false-negative results in all 3 tests. The other 9 specimens had greater than 100 mg albumin/g dry weight and albumin: alpha-1-trypsin inhibitor ratios of greater than 3.0; in subsequent faecal specimens the ratios were over 4.0. 176 meconium specimens from elsewhere in the UK were examined and these included 23 from infants who were subsequently proved to have CF. Six of these 23 CF specimens gave false-negative results, the other 17 being strongly positive. The origins of meconium serum protein suggest that infants with CF in whom meconium gives false-negative results have normal pancreatic functions at birth. The specificity of current meconium tests therefore cannot be improved as they depend on pancreatic dysfunction.

Albumins↗
PubMed1978

Effect of storage and heat on antimicrobial proteins in human milk.

Human milk, after storage and pasteurisation at 73 degrees C for 30 minutes at a milk bank, was found to have little surviving IgA, IgG, lactoferrin, lysozyme, and C3 complement. Accurate pasteurisation at 62.5 degrees C produced a loss of 23.7% of the lysozyme, 56.8% of the lactoferrin 34% of the IgG, but no loss of IgA. Storage by deep freezing at -20 degrees C for 3 months produced no appreciabile loss of lactoferrin, lysozyme, IgG, IgA, or C3.

Complement C3↗
PubMed1978

Meningococcal infection and proteolytic control.

Cascade enzyme inhibitors (C1-esterase inhibitor, C3b inactivator, antithrombin III) and other major proteolytic enzyme inhibitors (alpha 1 trypsin inhibitor, alpha 1 chymotrypsin inhibitor, inter-alpha-trypsin inhibitor, alpha 2 macroglobulin) as well as C3 and alpha 1 acid glycoprotein, have been examined in the sera of Nigerian patients suffering from meningococcal infection of varied severity. Patients with meningococcaemia had lower serum concentrations of important inhibitors than did patients with localised meningitic infection. Within the coccaemic group, those who died had the lowest values, notably of antithrombin III and alpha 2 macroglobulin (and also of C3). The clinical end-result of meningococcal infection may be related to the degree of disequilibrium of the linked system of proteolytic control induced by the meningococcal endotoxin.

Antithrombin III↗