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Biomedical subjects

A White

Publications and source records attributed to A White.

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

Gastroesophageal reflux and posterior laryngitis.

Esophageal acid exposure was assessed by 23-hour ambulatory pH monitoring and compared with a biopsy of the posterior larynx and proximal esophagus in 97 patients with hoarseness, burning pharyngeal discomfort, or globus sensation. Patient results were compared with normal acid exposure times obtained in 54 control subjects. In 24 patients there were laryngeal abnormalities but both esophageal biopsy results and acid exposure times were normal. Laryngeal disease was found in association with prolonged acid exposure time or esophagitis in only 17 of the 97 patients (17.5%) studied. Recent reports appear to have overestimated the importance of acid reflux as a cause of posterior laryngitis.

Adult↗
PubMed1989

Assessment of the potency of different standards in the immunoradiometric assay of ACTH.

There is no generally accepted human international reference preparation for ACTH. The different centres offering clinical ACTH measurement therefore select assay standards from the limited range of human-purified and synthetic preparations currently available. We have examined the relative potencies of three synthetic ACTH standards in comparison with the NIBSC human-purified 1-39 (code 74/555) in a two-site immunoradiometric assay (IRMA) for ACTH. All of the standards produced parallel curves in the IRMA but there was a wide variation in potency between the preparations giving highly significant differences in quality control and patients' ACTH results. Standards supplied by the National Hormone and Pituitary Programme, Bachem UK Ltd and Universal Biologicals Ltd gave lower ACTH results than results calculated using the NIBSC preparation. The potency differences between these standards emphasise the need for a reference preparation and, in the meantime, the necessity to define normal reference ranges for each laboratory.

Adrenocorticotropic Hormone↗
PubMed1989

Advantages of IRMA over RIA in the measurement of ACTH.

A technically simple and rapid two-site immunoradiometric assay (IRMA) for human ACTH, based on monoclonal antibodies (MAbs), was compared with a clinically validated ACTH radioimmunoassay (RIA). Both methods measure ACTH 1-39 in unextracted plasma and cross-react less than 0.5% with ACTH fragments. ACTH levels were assessed in 103 patient samples: for concentrations in the range 5.3-1000 ng/L, results by the two methods were significantly correlated (r = 0.82, n = 86, P less than 0.001). The IRMA was more sensitive and had a wider working range than the RIA (detection limits 5.3 ng/L (IRMA) vs 11 ng/L (RIA); CV less than 10% between 19 and 1000 ng/L (IRMA) and CV less than 15% between 30 and 400 ng/L (RIA). In two patients for whom discrepant results were obtained, measurement of ACTH by bioassay and ACTH precursors by direct IRMA demonstrated the greater accuracy of the ACTH IRMA result. The improved performance of the IRMA combined with its many practical advantages compared to RIA, make it ideal for use in detailed clinical and physiological studies which have previously been hampered by the poor reliability of ACTH measurement.

Adrenocorticotropic Hormone↗
PubMed1989

Submandibular duct relocation for drooling: a 10-year experience with 194 patients.

Management of drooling in the neurologically disabled individual has been accomplished with a team approach using surgical and nonsurgical methodology. Submandibular duct relocation has been the primary surgical procedure of choice in 194 patients during the past 10 years. Drooling has been reduced significantly in the majority of patients. Ranulas requiring intraoral sublingual gland excision occurred in 8% of patients. Persistent submandibular duct obstruction necessitating external excision of the submandibular gland occurred in 1% of the ducts relocated.

Adolescent↗
PubMed1989

Pro-opiomelanocortin gene expression and peptide secretion in human small-cell lung cancer cell lines.

Expression of the RNA coding for the ACTH-beta-lipotrophin precursor, pro-opiomelanocortin (POMC), has been demonstrated in five human small-cell lung cancer (SCLC) cell lines. Using Northern and slot-blot hybridization analysis of RNA and a bovine POMC cDNA as probe, the processed POMC RNA from SCLC cells was found to be approximately 1350 nucleotides in length, which is larger than that found in the normal human pituitary. Expression of the POMC gene was confirmed by measurement of ACTH precursors secreted by the cells, using a novel two-site immunoradiometric assay based on monoclonal antibodies, which directly quantifies both POMC and pro-ACTH but does not recognize ACTH. Levels of POMC in medium accumulated throughout the growth of the cells, in contrast to POMC RNA which showed a relatively constant level of expression. We conclude that human SCLC cell lines are valuable models for studying the aberrant expression and regulation of the human POMC gene.

Adrenocorticotropic Hormone↗
PubMed1989

Ivermectin treatment of patients with severe ocular onchocerciasis.

The treatment of onchocerciasis with diethylcarbamazine and suramin is associated with an exacerbation of ocular disease. This occurs more frequently in patients with severe onchocercal ocular disease. We assessed ocular changes following ivermectin treatment in 39 patients with severe ocular onchocerciasis. Patients were treated with 100, 150, or 200 micrograms/kg of ivermectin at either 1 or 2 year intervals and followed for 3 years. There was no evidence for an acute exacerbation of either anterior or posterior segment eye disease, and there was a marked improvement in ocular status in the group as a whole. There was a significant decrease in onchocercal involvement which was maintained for at least 3 years. Annual treatment with ivermectin can be used safely in patients with severe ocular disease and is beneficial over a prolonged period of time.

Adolescent↗
PubMed1988

Characterisation of the CDC7 gene product of Saccharomyces cerevisiae as a protein kinase needed for the initiation of mitotic DNA synthesis.

The product of the CDC7 gene of Saccharomyces cerevisiae, which is needed for the initiation of mitotic DNA synthesis, has homology with known and putative protein kinases. This homology is confined to the kinase catalytic domain, which has a unique organisation in CDC7. To demonstrate that, nonetheless, CDC7 protein has kinase activity, the gene was subcloned under the control of the SP6 promoter. Protein synthesised by transcription and translation in vitro was capable of transferring 32P from [gamma-32P]ATP to histone. This activity was not dependent on Ca2+ or cyclic nucleotides. A mutation of CDC7 constructed in vitro, in which the organisation of the kinase catalytic domain was converted to that found in all other similar enzymes, was unable to function in vivo, as judged by its inability to complement the cdc7-1 allele. This suggests that the abnormal structure of the CDC7 catalytic domain is a key element in the cellular function of this protein in initiating DNA synthesis.

Amino Acid Sequence↗
PubMed1988

The use of thiopentone in the treatment of non-organic locomotor disorders.

Eleven patients who had been fully investigated and diagnosed by orthopaedic surgeons as suffering from non-organic locomotor disorders were assessed and treated by a psychiatrist (AW) using a technique involving one or more injections of thiopentone sodium. The patients had been ill for an average of 3.4 yr (3 mths to 10 yr) and suffered severe disablement. Injections of short-acting barbiturates have been used for many years to facilitate the release and discussion of repressed feelings and emotions (narcoanalysis). This paper describes the use of a similar injection but given to facilitate the movement and return to normality of muscles whose function is deranged. The authors suggest that this technique be called 'narcokinesis'. All eleven patients showed initial improvement with seven patients showing moderate or marked benefit from the treatment at the time of discharge from hospital. A detailed case study is described of the advantages of narcokinesis and possible mode of action discussed. The general practitioners of these patients were sent a questionnaire by post and all replied. At the time of follow-up (6-9 yr) the whereabouts of three patients were unknown, three had died, two remained ill and three patients remained well or moderately well.

Adolescent↗
PubMed1988

Neuroendocrine changes produced by competition stress on the Thoroughbred race horse.

1. Packed cell volume (PCV) and plasma catecholamines, cortisol and glucose were determined in blood samples obtained from race horses, after competition. 2. All these parameters were higher than basals but catecholamines increased 6-7 times while cortisol was enhanced only by 25%. 3. The increase of glucose and PCV was related to the rise of catecholamines. 4. In samples withdrawn after overnight stress caused by change of horseshoes, it was not possible to find values from basal values significantly different. 5. Influence of nervous temperament was observed only in the higher hematocrit found in basal conditions, particularly in females.

Animals↗
PubMed1988

Immunoreactivity of various peptides in typical and atypical bronchopulmonary carcinoid tumours.

The presence of a number of regulatory peptides (bombesin, gastrin, glucagon, somatostatin, calcitonin and ACTH) was compared in 30 typical carcinoid tumours and 27 well differentiated neuroendocrine carcinomas (atypical carcinoids) using conventional immunocytochemistry. Strong immunostaining for one or more peptide was observed in 97% of the typical carcinoids (29/30) whereas only 67% of the neuroendocrine carcinomas showed immunoreactivity. The peptide most frequently detected in typical carcinoids was bombesin (67%), while gastrin was more common in neuroendocrine carcinomas (44%). Immunoreactivity for more than one peptide was present in 33 tumours and in three cases, six different peptides were detected. The study shows that immunoreactivity to various peptides is more common in typical carcinoids than well differentiated neuroendocrine carcinomas. The significance of these findings is discussed.

Adolescent↗
PubMed1988

Back impairment and disability determination. Another attempt at objective, reliable rating.

Present disability evaluation schedules for the low back are not scientifically based and produce very great interexaminer differences. The authors have developed a new impairment schedule based on a comprehensive review of the medical literature and the collected opinions of a large number of back specialists. Tests of the new schedule show a marked decrease in interexaminer differences compared to the prior California disability rating schedule. The impairment schedule can be readily adapted to any legal system of disability rating and can be modified easily to reflect new medical knowledge. The result should be a disability rating which is more objective, more scientifically valid, and more consistent, reducing litigation, with fairness to both the low-back impaired worker and the employer.

Disability Evaluation↗
PubMed1988

Early results of spinal fusion using variable spine plating system.

Seventy-seven consecutive patients underwent application of variable spine plating (VSP) spinal plates between August 1984 and October 1985. Sixty-four percent had previous procedures at the same level or levels operated. Operative indications were spinal stenosis, segmental instability, unstable spondylolisthesis, herniated disc with instability, pseudoarthrosis, unstable fracture, and failed surgery syndrome with evidence of one of the preceding. Overall results showed 30% excellent, 30% good, 34% fair, 6% poor. There were four deep wound infections and 19 patients with one or more broken screws. Screw alignment and the angular relationship of each screw to the spinal plate are considered important technical factors in minimizing screw failure. Vigorous distraction of the vertebrae using interpedicular screws is rarely indicated. Twenty-four patients required reoperation. We feel the procedure is relatively indicated in cases of moderate to severe instability, such as some cases of spondylolisthesis, failed surgery with marked segmental instability, the obese, deconditioned patient, or cases of spinal stenosis rendered very unstable by surgical decompression, and most strongly indicated in unstable lumbar and thoracolumbar fractures.

Adult↗
PubMed1988

Normal magnetic resonance imaging with abnormal discography.

In degenerative lumbar spine disease, recent studies have supported the clinical usefulness of discography, especially when used with computed tomography (CT) scanning. The role and capabilities of magnetic resonance imaging (MRI) scanning are currently evolving and being defined. This study reviews a series of patients with prolonged disabling symptoms who had normal MRI scans and abnormal discography. Discograms and discogram-CT scans may at times allow detection of clinically correlative and significant pathology (usually annular disruptions) not suggested by MRI scanning. This fact should be considered in patients with normal MRI scanning and continuing unexplained symptomatology.

Adult↗
PubMed1988

The effect of oxytocin infusion on adenohypophysial and adrenal cortical responses to insulin-induced hypoglycaemia.

The responses of plasma adrenocorticotrophin (ACTH), cortisol, growth hormone (GH) and prolactin to insulin-induced hypoglycaemia were studied in six lean male subjects (age 22-29 years). Intravenous insulin tests were performed with and without oxytocin infusion. Blood sugar nadir occurred at the onset of symptoms (time S) with no significant differences between oxytocin and saline infusion. During the oxytocin infusion mean plasma oxytocin increased from 1.9 pmol/l to 138 pmol/l. Peak increase in plasma ACTH (oxytocin 266 +/- 54 ng/l; saline 281 +/- 43 ng/l, mean +/- SEM) was at S + 10 min while peak plasma cortisol (oxytocin 680 +/- 47 nmol/l: saline 656 +/- 40 nmol/l) was measured at S +/- 60 min, peak GH (oxytocin 96 +/- 17.8 mU/l; saline 106 +/- 18.6 mU/l) at S + 60 min and prolactin (oxytocin 1332 +/- 239 mU/l; saline 1242 +/- 273 mU/l) at S + 30 min. There were no significant differences in plasma concentrations of ACTH, cortisol, GH or prolactin between saline and oxytocin infusion. The results indicate that oxytocin has no effect on plasma ACTH, cortisol, GH and prolactin responses to insulin-induced hypoglycaemia. In particular they fail to support previous studies which suggested an inhibitory role for oxytocin in ACTH secretion.

Adrenal Cortex↗
PubMed1988

Oral tranexamic acid in the management of epistaxis.

This study evaluated oral tranexamic acid as an adjunct in controlling epistaxis and preventing or reducing recurrent epistaxis. Patients entered into the trial were randomized in double blind fashion to placebo or tranexamic acid 1 g, 3 times daily. Treatment continued for 10 days. The patients were reviewed daily and any rebleeds categorized into minor, moderate or severe according to length and briskness of bleed and subsequent treatment. Of the 89 patients who completed the course of tablets, 25 (57%) in the placebo group and 21 (47%) in the treatment group had a rebleed. More patients in the placebo group had minor and moderate rebleeds, but the same number of patients in the placebo and treatment groups had severe rebleeds; this difference was not statistically significant. Oral tranexamic acid is, therefore, of no proven value as an adjunct in the treatment of epistaxis in patients requiring hospital admission.

Administration, Oral↗
PubMed1988

Intranasal adhesion formation following surgery for chronic nasal obstruction.

Several publications have addressed the problem of atrophic rhinitis and ozaena following turbinate resection for chronic nasal obstruction, but little attention has been given to the problem of intranasal adhesion formation following this procedure. To determine the incidence of postoperative intranasal adhesion formation, a retrospective study of 479 operations on the inferior turbinate and nasal septum, either alone or in combination, was carried out. Adhesion formation complicated 36.2% of turbinate resections, 30.6% of turbinate resections in combination with septal surgery and only 6.8% of all the other procedures. There was also a significantly higher incidence of postoperative haemorrhage following turbinate resection (7.4%) than that following other procedures (1.9%). There was no noted occurrence of atrophic rhinitis, rhinitis sicca or ozaena.

Hemorrhage↗