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Biomedical subjects

G Bell

Publications and source records attributed to G Bell.

At least 19 recordsLinked to original sources
PubMed1992

Electrical states in the rabbit brain can be altered by light and electromagnetic fields.

The effect of low-frequency magnetic fields on the rabbit electroencephalograph (EEG) was studied using a quantitative procedure that permitted statistical evaluation of the response of individual animals. The field conditions used were those predicted by various theories to result in field-animal interactions; light and sham exposure were employed as positive and negative controls, respectively. Sixty-seven percent of the rabbits exhibited changes in the EEG power spectra when light was presented in 2-s epochs; none of the animals responded to sham exposure. When 1 Gauss, 5 Hz, was presented in 2-s epochs, 100% of the animals tested responded to the presence of the field. The rabbits did not respond when the magnetic-field frequency was higher than the physiological range (1-20 Hz) or when it was tuned for resonance of K+. The results showed that an electrical state function may be operationally defined for the rabbit brain, and used to assess the occurrence of an interaction between an animal and external magnetic fields.

Animals↗
PubMed1992

Sources of variance in protein heterozygosity: the importance of the species-protein interaction.

We report on a detailed survey of protein heterozygosity in Canadian freshwater fish and mammals. A simple one-way analysis showed substantial variance among species. However, a two-way analysis of species and proteins showed that there was little if any variance among species or among proteins, but a very large species-protein interaction. We could not remove this interaction by analysing taxa separately by constructing completely balanced datasets, by eliminating study bias or by excluding monomorphic proteins, and we could not decompose the interaction by classifying enzymes according to their form and function. We conclude that most of the variance in protein heterozygosity is attributable to species-protein interaction. This casts some doubt on the interpretation of comparative studies of mean heterozygosity among species or among proteins. Our result seems inconsistent with the neutral theory of protein variation but not with the differential action of natural selection.

Analysis of Variance↗
PubMed1992

Psychiatric admissions and social deprivation: is the Jarman underprivileged area score relevant?

STUDY OBJECTIVE: The aim was to assess the relationship between social deprivation, as measured by the Jarman under-privileged area score (UPA score), and psychiatric admission rates and length of stay within an inner London borough. DESIGN: The study was a retrospective survey of psychiatric admission rates for electoral wards in the London borough of Islington in relation to Jarman UPA scores and subscores. SETTING: Islington Health Authority psychiatric admission wards at the Whittington and Friern Hospitals. PATIENTS: All admissions during the year of 1985 were studied (n = 778). MAIN RESULTS: No correlation was found between the total Jarman UPA score and either admission rates or length of stay. There was, however, a correlation between the Jarman UPA subscore for ethnic minorities and admission rates (r = 0.409, p less than 0.05), and between the Jarman UPA subscore for lone parents and length of stay (r = 0.390, p less than 0.05). CONCLUSIONS: The Jarman UPA score at electoral ward level is not related to psychiatric morbidity, and should not therefore be used for planning local service provision.

Adult↗
PubMed1992

Are groups for parents of children with sleep problems effective?

Sleep groups are increasingly being used to support parents who have children with sleep problems. JANINA SZYNDLER and GEORGINA BELL present a model of sleep groups developed by clinical psychologists in Kingston and Esher and examine the effectiveness of this approach.

Child Behavior Disorders↗
PubMed1991

Spectrum of invasive pulmonary aspergillosis in immunocompetent patients with chronic obstructive pulmonary disease.

Invasive pulmonary aspergillosis is a well-recognized complication in immunocompromised patients, especially those with neutropenia. We report four cases of invasive pulmonary aspergillosis in patients whose main underlying disease was chronic obstructive pulmonary disease (COPD). Two patients had an acute fatal course, one had chronic necrotizing pulmonary aspergillosis ending in an acute fatal course, and the other had a semiacute disease that responded to amphotericin B. Autopsy on three patients showed invasive pulmonary aspergillosis in both lungs, and tissue invasion was documented by transbronchial biopsy in the patient who survived. Retrospective review of all cultures that grew Aspergillus species from bronchoscopic specimens showed no false-positive results, and this procedure proved to be the most useful maneuver in making the diagnosis. Invasive pulmonary aspergillosis should be in the differential diagnosis in patients with COPD and unexplained pulmonary infiltrates.

Acute Disease↗
PubMed1991

Psychiatric screening of admissions to an accident and emergency ward.

One hundred medical and surgical patients admitted to an accident and emergency ward were screened for psychiatric disorder. A psychiatric diagnosis was made in 37 patients, 32 of whom were correctly identified by the GHQ. Psychiatric morbidity was associated with being single, lower social class, unemployment, homelessness and living in Bloomsbury Health District or north-east London. It was also associated with not being registered with a GP. The 14 overdose patients were no more likely to receive a psychiatric diagnosis than other patients, yet constituted most of the psychiatric referrals. Few patients were asked by medical staff about emotional worries or problems. A desire to be asked such questions and a past psychiatric history were associated with a psychiatric diagnosis. Routine screening of psychiatric morbidity in both medical and surgical patients and appropriate psychiatric referral of identified patients is recommended. A system of facilitating GP registration is necessary, as much of the morbidity identified could be contained within primary care.

Adolescent↗
PubMed1991

Analysis of information processing stages using event-related potentials.

The event-related potential (ERP) was recorded to identify the time epochs during which different independent variables have their effects on stages in a memory search task. Stimulus intensity, memory set size and response type were varied. For the most part, the order and timing of effects (evaluated by Principal Components Analysis of within-subjects ERP differences) were consistent with the presumed underlying stages, except for early effects of response type prior to memory set effects (suggesting precategorical target recognition). The usefulness of this type of analysis for the investigation of information processing stages is discussed.

Adult↗
PubMed1990

Screening for psychiatric morbidity in an accident and emergency department.

One hundred and twenty A&E Department daytime attenders were screened for psychiatric disorder in a two stage procedure. Thirty-three patients were identified as General Health Questionnaire (GHQ) 'cases' of whom 28 agreed to a psychiatric interview using the Clinical Interview Schedule. Twenty-eight GHQ 'non-cases' were also interviewed. A psychiatric diagnosis was made in 24 patients, 21 of whom were GHQ cases. Patients were more likely to suffer from psychiatric morbidity if the presenting complaint was other than minor trauma. There were trends for psychiatric morbidity to be associated with not being married and living in Bloomsbury Health District (No Fixed Abode or resident) or Northeast London. Sixty-nine percent of cases had a positive past psychiatric history. Ten of 12 cases (83%) requiring primary care intervention were not registered with a GP. It is suggested that appropriate intervention would be for A&E Departments to routinely facilitate such registration. In addition, resources need to be released to make 9am to 5pm walk-in psychiatric services commonplace.

Adult↗
PubMed1990

Decompression of the brain stem and superior cervical spine for congenital/acquired craniovertebral invagination: an interdisciplinary approach.

A transoropharyngeal/transpalatal approach to the clivus and anterior cervical spine in association with a midline labiomandibular glossotomy has proved successful in the treatment of craniovertebral instability. Nine cases at this institution between 1978 and 1986 were retrospectively reviewed. A head-and-neck surgeon, along with a neurosurgeon and/or orthopedic surgeon collaborated on these procedures. The indications, methods, operative techniques, results and postoperative complications are presented.

Adolescent↗
PubMed1990

Incidence of Campylobacter pylori in a consecutive series of surgical patients referred for endoscopy.

Over a 9-month period, 109 consecutive patients referred from general surgical out-patient clinics for endoscopy were studied. The presenting symptoms, endoscopic diagnosis, clinical history and degree of histological gastritis were determined. The presence of the organism Campylobacter pylori in oesophageal, antral and duodenal biopsies was detected by a combination of culture, histology and fluorescence microscopy. C. pylori was identified in 49.5% of patients by at least one of the methods described. The organism was present only in antral biopsies in patients with both normal and abnormal endoscopies. The presence of C. pylori was significantly associated with the symptom of dyspepsia, and endoscopic diagnosis of peptic ulceration and a greater degree of histological gastritis. Analysis of the clinical history of the patients with a normal endoscopy suggests that a proportion of these patients (7 of 20) had previous evidence of peptic ulceration. Treatment with H2-receptor antagonists may heal ulceration but fails to eradicate C. pylori.

Adolescent↗
PubMed1989

Laparoscopy, ultrasound and computed tomography in cancer of the oesophagus and gastric cardia: a prospective comparison for detecting intra-abdominal metastases.

We have evaluated the sensitivity, specificity and accuracy of laparoscopy under general anaesthesia, ultrasound and computed tomography (CT) in detecting intra-abdominal metastases in 90 consecutive patients with carcinoma of the oesophagus or cardia. Metastases were histologically confirmed as hepatic in 25 patients, nodal in 35 and peritoneal in nine. All investigations had high specificity (86-100 per cent) for each type of metastasis. Laparoscopy was found to be significantly more sensitive (P less than 0.01; P less than 0.02) and more accurate (P less than 0.01; P less than 0.01) than either ultrasound or CT, respectively, with regard to hepatic status. Although laparoscopy performed best with regard to nodal metastases, this reached statistical significance only when sensitivity of ultrasound was compared (P less than 0.01). Neither ultrasound nor CT detected any peritoneal metastases, although laparoscopy detected eight out of nine, giving a sensitivity of 89 per cent and an accuracy of 98 per cent. There was no morbidity or mortality associated with laparoscopy, which offers a safe, reliable method of determining intra-abdominal status and may obviate the need for surgery in some patients with malignant dysphagia.

Abdominal Neoplasms↗