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Biomedical subjects

J Walker

Publications and source records attributed to J Walker.

At least 343 records · Page 19Linked to original sources
PubMed1989

Enterovirus-specific IgM in the diagnosis of meningitis.

Samples of serum from 557 patients with a clinical diagnosis of meningitis or encephalitis and referred to the Epsom Public Health Laboratory during a period of 3 years were tested for enterovirus-specific IgM in a mu capture enzyme-linked immunosorbent assay (ELISA). Enterovirus-specific IgM was detected in 45% samples from all age groups. In the 3-5-year age group, 67% specimens were positive. A notable male predominance (73%) was seen in the age group 0-15 years. As predicted, a seasonal increase in incidence was found in the summer and autumn months. Data from a questionnaire sent to the referring laboratories showed only a 5% enterovirus isolation rate from cerebrospinal fluids when isolation of a virus was attempted. The enterovirus IgM ELISA is a sensitive economical and rapid method for use in the diagnosis of viral meningitis.

Adolescent↗
PubMed1989

Improved pulmonary function in chronic quadriplegics after pulmonary therapy and arm ergometry.

Quadriplegics suffer from restrictive lung disease due to neural damage, spasticity, and prolonged immobilisation. These studies were undertaken to see whether respiratory therapy can improve expiratory capacity in quadriplegics. Fifteen patients with chronic quadriplegia participated in a programme of pulmonary therapy and resistance exercise for 7 to 12 weeks. Pulmonary therapy consisted of incentive spirometry for 15 minutes a day 3 to 5 days per week. Resistance exercise consisted of pedalling an arm ergometer up to 30 minutes three times a week. Forced vital capacity was measured with the subject in a wheelchair wearing a nose clip. The volume of expired air (max Ve) was as determined with a paramagnetic analyser during arm ergometry. The volume of expired air was divided by the number of breaths, giving the volume of expired air per breath (Ve). The results indicated that a combination of incentive spirometry and arm ergometry improves vital capacity and increased the maximum volume of expired air during exercise. These methods are non-invasive, and such modalities should constitute part of the rehabilitation of patients with neuromuscular disease.

Adolescent↗
PubMed1989

Successful management of faecal incontinence using the enema continence catheter.

Faecal incontinence in the school age child is a social and educational handicap, and its relief can revolutionise the life of the family. Shandling and Gilmour have successfully managed this using their "enema continence catheter" for effective colonic lavage. We report our methods and experience using this technique.

Adolescent↗
PubMed1989

Monoclonal antibody to SER immune suppressor detects polymeric forms of haptoglobin.

A series of monoclonal antibodies has been developed which is directed to a serum immunosuppressive factor, known as suppressive E-receptor factor (SER). SER, purified from the body fluids of cancer patients, is a polymeric form of haptoglobin, which is 100-1,000 times more potent an immunosuppressor than normal plasma haptoglobin and is immunochemically analogous to the neonatal form. Unlike the neonatal haptoglobin found in cord blood, SER, however, does not contain bound-hemoglobin. One group of monoclonal antibodies described in this study detects the polymeric forms of haptoglobin (SER) under non-denaturing conditions, but fails to recognize SER under the denaturing conditions of SDS-PAGE. A second group of monoclonal antibodies reacts only with the alpha subunit of haptoglobin but not with the beta subunit; in contrast, the commercially prepared polyclonal antisera to haptoglobin react with both the alpha and beta subunit. The average level of SER in normal human plasma (n = 19) was 1.0 micrograms/ml, regardless of age or sex. Since macrophages appear to secrete SER but do not synthesize haptoglobin, SER may represent an oxidized form of plasma haptoglobin generated from macrophages activated during an inflammatory response. These studies suggest that SER may be a negative feed-back regulator of immune response produced by activated macrophages.

Adult↗
PubMed1989

The expression in Escherichia coli of sequences coding for the p18 protein of human immunodeficiency virus and the use of the recombinant protein in characterizing a panel of monoclonal antibodies against the viral p18 protein.

The sequences coding for the p18 protein of CBL-1, a British human immunodeficiency virus (HIV) type 1 isolate, were expressed in Escherichia coli as beta-galactosidase fusion proteins. The recombinant proteins were used to screen a panel of five monoclonal antibodies (MAbs) raised against p18 expressed in CBL-1-infected cells. The regions containing the epitopes for four of the MAbs were located using carboxy deletion mutants and synthetic peptides. The epitope of one of the MAbs (1D9) was reconstructed as part of an unfused, E. coli-expressed p18 protein using the polymerase chain reaction technique. Four different HIV strains and one lymphadenopathy virus type 2 strain were analysed by fluorescence-activated cell sorting of live infected cells using the p18-reactive MAbs.

Amino Acid Sequence↗
PubMed1989

The Wessex Growth Study: first report.

The Wessex Growth Study is a community-based longitudinal survey of short children recruited from two Health Districts in Wessex during 1985-86 (cohort I) and 1986-87 (cohort II). Screening of new school entrants during 1985-86 identified only 1.3% who were at or below the 3rd centile for height as defined by Tanner and Whitehouse, suggesting a strong secular trend and an urgent need for updated height charts. After exclusion of the small number of children with underlying organic pathology and those from ethnic minorities, there were 84 children in cohort I on whom this report is based. These apparently normal, short children were sex- and age-matched with normal controls (10th-90th centile) from the same school class. Forty-two per cent of cohort I had a delayed bone age, and 34% lay above the 3rd centile after correction for parental height. Forty-four per cent were of low birth weight. The correlation between two successive height velocities measured at 6 and 12 months was only -0.14 for cohort I and -0.15 for their controls. Twelve-month mean height velocity SD scores (SDS) were -0.45 and +0.25, respectively, corresponding to the 33rd and 60th centiles, and rather higher than the 25th and 50th centiles expected in view of the heights of these children. Thirty-eight per cent of cohort I had a 12-month height velocity below the 25th centile, and in 16% height velocity was below the 10th centile. As a group, the children in cohort I grew more slowly than their controls, but the height velocity in 88% of cases lay within the control range.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Determination by Skeleton↗
PubMed1989

Effect of Streptococcus pneumoniae on human respiratory epithelium in vitro.

A total of 11 of 15 Streptococcus pneumoniae culture filtrates and all five bacterial autolysates produced by cell death in the stationary phase caused slowed ciliary beating and disruption of the surface integrity of human respiratory epithelium in organ culture. This effect was inhibited by cholesterol and was heat labile and reduced by standing at room temperature but was stable at -40 degrees C. The activity was detected at the late stationary phase of culture and was associated with the presence of hemolytic activity. Gel filtration of a concentrated culture filtrate and autolysate both yielded a single fraction of approximately 50 kilodaltons which slowed ciliary beating and were the only fractions with hemolytic activity. Rabbit antiserum to pneumolysin, a sulfhydryl-activated hemolytic cytotoxin released by S. pneumoniae during autolysis, neutralized the effect of the culture filtrate on respiratory epithelium. Both native and recombinant pneumolysin caused ciliary slowing and epithelial disruption. Electron microscopy showed a toxic effect of pneumolysin on epithelial cells: cytoplasmic blebs, mitochondrial swelling, cellular extrusion, and cell death, but no change in ciliary ultrastructure. Recombinant pneumolysin (10 micrograms/ml) caused ciliary slowing in the absence of changes in cell ultrastructure. Release of pneumolysin in the respiratory tract during infection may perturb host defenses, allowing bacterial proliferation and spread.

Autolysis↗
PubMed1989

Giemsa staining for cysts and trophozoites of Pneumocystis carinii.

Although Giemsa staining has been routinely used for the detection of trophozoites and intracystic bodies in smears of bronchoalveolar lavage fluid (BAL) from patients with Pneumocystis carinii pneumonia, it does not normally stain the cyst wall. For detection of the cysts other stains such as toluidine Blue 'O' and methenamine silver must be used as well. Sulphation of smears before staining with Giemsa allows cysts to be visualised, thus enabling a single stain to be used to show all the stages of BAL or sputum, which is particularly useful, considering the increase in the prevalence of P carinii pneumonia in conjunction with the spread of AIDS.

Animals↗
PubMed1989

Regulation of the hepatic response to glucagon: role of insulin, growth hormone and cortisol.

The hepatic response to glucagon was investigated in five groups of animals: (1) controls; (2) excess growth hormone (GH; tumor-bearing); (3) streptozotocin-induced diabetic; (4) cortisol-treated, and (5) insulin-treated animals. Blood samples were collected from the animal models and hepatocytes were prepared and used for glucagon-binding studies and studies of total glucose production, gluconeogenesis and glycogen determinations. Glucagon binding was elevated in GH-tumor-bearing and cortisol-treated hepatocytes but lower in hepatocytes from diabetic animals. Basal total glucose production wash higher in hepatocytes from diabetic rats but not changed in hepatocytes from GH-tumor-bearing, insulin-treated or cortisol-treated animals. Glucagon significantly stimulated total glucose production in hepatocytes from control, insulin-treated and cortisol-treated but not diabetic and GH tumor models. Gluconeogenesis as evaluated by alanine conversion to glucose was significantly increased in hepatocytes from diabetic and cortisol-treated animals and was significantly lower in hepatocytes from GH-tumor-bearing animals. Glucagon failed to significantly stimulate gluconeogenesis in hepatocytes from diabetic and tumor-bearing animals. Hepatic glycogen content was significantly decreased in diabetic and GH-tumor-bearing animals but not changed in insulin-treated and cortisol-treated animals. We conclude that increased glucagon binding was not always correlated with an increase in glucagon-stimulated glycogenolysis, gluconeogenesis or increased sensitivity to glucagon. Persistent hyperinsulinism may effectively suppress glucagon- or cortisol-stimulated pathways.

Alanine↗
PubMed1989

Growth hormone treatment of children with short stature increases insulin secretion but does not impair glucose disposal.

Pediatricians willing to administer GH to non-GH-deficient children with short stature are concerned about the potential adverse effects of this hormone on glucose homeostasis and insulin action. This study was designed to determine the effects of GH therapy on carbohydrate metabolism in 10 prepubertal non-GH-deficient children with short stature. After 12 months of treatment with 0.3 U GH/kg BW.day, which resulted in an increase in height velocity from 4.0 +/- 0.3 (+/- SE) to 11.0 +/- 0.4 cm/yr, glucose tolerance was not impaired in these children. Not only were their fasting and postprandial plasma glucose concentrations unchanged from the pretreatment values, but basal glucose turnover did not vary; it was 0.53 +/- 0.04 before and 0.64 +/- 0.06 mmol/m2.min after GH treatment. Using the euglycemic clamp technique, the dose-response curves describing the effects of insulin on glucose disposal were comparable before and after GH treatment. There was a consistent 1.5- to 2-fold increase in plasma insulin and C-peptide concentrations during GH treatment, in both the basal and postprandial states, and after oral glucose or iv glucagon stimulation. We conclude that the GH regimen employed was remarkably effective in increasing growth velocity and devoid of detectable diabetogenic effects during a 1-yr treatment period in these non-GH-deficient children. (glucose, 1 mmol/L = 18 mg/dL; insulin, 1 pmol/L = 0.139 microU/mL; C-peptide, 1 pmol/L = 0.003 ng/ml).

Body Height↗
PubMed1989

Human papillomavirus genotype as a prognostic indicator in carcinoma of the uterine cervix.

The clinical implications of specific human papillomavirus (HPV) types in invasive cervical carcinomas are only beginning to be appreciated. In this series of 100 women with cervical cancers analyzed for the presence of HPVs 6, 11, 16, 18, and 31 by Southern blot hybridization, a more aggressive clinical behavior was demonstrated for tumors containing HPV 18 than for those with HPV 16 or those in which no HPV was identified. Among 69 stage Ib tumors, no significant differences were found in the size of tumor, presence of parametrial involvement, or lymph node metastasis among patients whose tumor contained HPV 16, HPV 18, or no HPV DNA; however, 45% of the women with HPV 18-containing tumors (five of 11) had recurrence, as compared with only 16% of those with HPV 16 (five of 31) during the 20-month mean follow-up period. This tendency for HPV 18-containing tumors to recur was seen with all histologic subtypes of cervical cancers and with all grades of tumor. In addition, patients with HPV 18-containing tumors were more likely to give a history of recent normal Papanicolaou smears than were those whose tumors contained HPV 16. Forty-four percent of women with HPV 18 in their tumors had a history of three class I Papanicolaou smears in the 3 years before the diagnosis of cancer, whereas a similar history was elicited in only 16% of those with HPV 16 in their tumors, suggesting that HPV 18-containing tumors might progress to invasion without a prolonged preinvasive period.

Carcinoma, Squamous Cell↗
PubMed1989

Effects of allopurinol in experimental endotoxin shock in horses.

The effect of allopurinol pretreatment 12 hours before an intraperitoneal challenge with a sublethal dose of Escherichia coli endotoxin (50 micrograms kg-1) was evaluated in 18 horses. The horses were divided among three equal groups: 1-endotoxin alone; 2-5 mg allopurinol kg-1 bodyweight plus endotoxin; and 3-50 mg allopurinol kg-1 bodyweight plus endotoxin. A variety of evaluation parameters were used. No differences among the groups were noted in rectal temperature, heart rate, respiration rate, haematological values, blood PaO2, blood PaCO2, blood pH or blood bicarbonate. Significant (P less than 0.05) differences between the groups were noted as regards the changes in capillary refill time, base excess, blood glucose, blood lactate, blood beta-glucuronidase and recumbency time. The protection afforded by 5 mg allopurinol kg-1 appeared to be superior to that with 50 mg allopurinol kg-1.

Allopurinol↗
PubMed1989

A bidirectional, turbulent, delaying, centripetal, suction filter.

The physiologic functions of the outer retina and the pathophysiology of drusen-related macular failure are best explained by attributing the properties of a bidirectional, turbulent, delaying, centripetal, suction filter to Bruch's membrane.

Cell Membrane Permeability↗
PubMed1989

Is phimosis overdiagnosed in boys and are too many circumcisions performed in consequence?

Thirty thousand circumcisions are performed annually in England and 70% of these are upon boys under 15 years of age. In the Mersey Region some 950 boys are circumcised each year for medical indications, the commonest being 'phimosis', which accounts for 87% of cases, of whom almost one-half are under 5 years of age. Regional practice is compared with that of our Unit, where the majority of referrals had developmentally non-retractile foreskin rather than true phimosis, where circumcisions for phimosis and for balanoposthitis occurred in almost equal numbers, and where no example of true phimosis was seen in boys under 5 years of age. It appears that in the Mersey Region many boys are circumcised for development non-retractability of the prepuce rather than for true phimosis and that in consequence some two-thirds of the operations are unnecessary.

Adolescent↗