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Biomedical subjects

D Bellamy

Publications and source records attributed to D Bellamy.

At least 37 records · Page 2Linked to original sources
PubMed1984

Determination of extracellular pH and tissue temperature in transplantable rat tumors by use of inductive loop telemetry.

Radiotelemetry was used to determine changes in extracellular pH and tissue temperature during tumor development in rats of an inbred WAB substrain. A progressive decrease in the pH of the tumor tissue compared with the pH level in control tissue was observed, so that by 4 days after tumor implantation the tumor tissue was about 0.4 pH units lower than control values. Thereafter, tumor pH rose progressively to reach a value comparable with control levels at 8 days, when the experiment was terminated. No significant difference was detected between the temperature in the tumor tissue and the temperature in the control tissue. Therefore, the observed changes in pH appeared to be independent of temperature. Studies on the rate of tumor cell proliferation during the experiments demonstrated a significant inverse relationship between tumor cell mitotic rate and pH, with the highest rates of cell proliferation occurring at the time of lowest pH values.

Animals↗
PubMed1984

Pulmonary disease in patients with Marfan syndrome.

Hospital case notes and chest radiographs of 100 patients with Marfan syndrome were investigated for evidence of pulmonary disease. The criteria for inclusion of details of a given patient in the study were the occurrence of Marfan abnormalities in at least two separate body systems (skeletal, cardiovascular, ocular) or in one body system where there was a family history of a classically affected first degree relative. Selection of cases was biased towards those with cardiorespiratory problems by virtue of the hospitals from which the patients were drawn. Forty eight patients underwent cardiac surgery. Eleven patients had a history of spontaneous pneumothorax, which had been recurrent in 10 cases and bilateral in six. Eight had had pneumonia or excessively frequent respiratory infections and two had bronchiectasis. Chest radiographs showed emphysematous bullae in five, upper lobe fibrosis in four, and aspergilloma in two. The cases reviewed together with other published evidence suggest that spontaneous pneumothorax and bullae are causally related to Marfan syndrome. The presence of idiopathic upper lobe fibrosis in four Marfan patients is interesting but provides insufficient evidence to assess possible causality.

Adult↗
PubMed1984

Pulmonary tuberculosis complicated by haemophagocytic syndrome and rifampicin-induced tubulointerstitial nephritis.

The benign, or infection-associated, haemophagocytic syndrome (IAHS) is a rare bone marrow disorder of macrophage cell proliferation diagnosed most commonly in immune compromised patients who develop herpes type viral infections (Risdall et al. 1979). It has also been reported in association with bacterial infections and rarely with mycobacterial infection (Chandra et al. 1975; Mamoharon & Catovsky 1981; Bultmann et al. 1982). Despite being potentially reversible it may produce a life-threatening pancytopenia (Seligman et al. 1972). We report a further case of the haemophagocytic syndrome associated with Mycobacterium tuberculosis in which thrombocytopenia was the predominant feature. There were unusual features in the clinical presentation and the patient's treatment and recovery were subsequently complicated by rifampicin-induced renal failure.

Bone Marrow↗
PubMed1983

The effect of dietary restriction on thymus autonomy.

Fifty percent dietary restriction allows for continued body growth in young animals, whereas in older animals this dietary regime resulted in a 25% drop in body weight over a 10-wk period. This resulted in a relatively low rate of mitosis in the thymus tissue from young animals so that thymus size was maintained in proportion with body weight. There was no evidence to suggest that the thymus glands from dietary restricted young animals could not maintain their role in immune function. In the older animals dietary restriction resulted in depletion of thymic lymphocytes, despite a relatively high rate of cell division. It is postulated that this may be a result of stress caused by the dietary regime.

Age Factors↗
PubMed1982

Annual decline of lung function in pulmonary emphysema: influence of radiological distribution.

Fifty-six male patients with pulmonary emphysema and normal serum alpha 1-antitrypsin were followed for a minimum period of three years (range 3-13 yr) to observe the effects of the radiological distribution of emphysema on the annual rate of change of lung function indices. The subjects were placed in three categories--upper zone (UZ), lower zone (LZ), and generalised (G). The influence of smoking was taken into account with subjects in each radiographic category being divided into ex-smokers (group EX-S) and continuing smokers (group S). The rate of decline of FEV1, VC, TCO, and KCO was greater in group S than EX-S in all three x-ray categories. In group S, FEV1, VC, TCO, and KCO declined significantly faster in UZ emphysema than in G emphysema. In group EX-S, FEV1, TCO, and PaO2 declined significantly faster in UZ than G emphysema but VC remained unaltered. KCO and PaCO2 did not change significantly in any radiographic category in either group S or EX-S. Patients with G and LZ emphysema underwent very similar physiological changes over the course of time. Those with UZ emphysema, however, complained of exertional dyspnoea at an earlier age; a number of their lung function indices deteriorated at a faster rate than in patients from the other two categories, suggesting that UZ emphysema is a different disease entity.

Adult↗
PubMed1982

Effects of ipratropium bromide and fenoterol aerosols in pulmonary emphysema.

In patients with radiological evidence of pulmonary emphysema the bronchodilator drugs fenoterol and ipratropium bromide produced a considerable increase in vital capacity and reduction in residual volume. The response to fenoterol was virtually complete 15 minutes after administration, but after ipratropium bromide vital capacity was still increasing at 60 minutes. The change in vital capacity was slightly greater with a combination of the two drugs than with either used alone. Changes in FEV1 and peak flow rate were small.

Aerosols↗
PubMed1982

A comparative study of age involution of the bursa of Fabricius an thymus in birds.

The differential growth patterns of the bursa of Fabricius and thymus of Comet strain chicks were examined up to 60 days of age. It was found that the bursa increased in size, in relation to body weight, during the first 3 wk of life but thereafter underwent involution. The thymic tissue increased in weight throughout the period of investigation, from 3 to 58 days of age; when this total weight was related to the number of thymus glands, it was found that during the first days of life, thymus tissue was increased by the growth of pre-existing thymic glands but that this was followed by a phase when new thymus glands appeared with no increase in the size of the largest glands. Although the growth and involution patterns of the thymus and bursa differed it was found that, for each age group, a linear relationship existed between the bursa and thymus, suggesting that there may be a common control of development in the two organs.

Aging↗
PubMed1982

The influence of cigarette smoking and its withdrawal on the annual change of lung function in pulmonary emphysema.

Fifty-six male patients with pulmonary emphysema were followed for a minimum period of three years (range 3-13), to observe the effects of smoking and smoking withdrawal. The subjects were divided into smokers (Group S) and ex-smokers (Group EX-S). Forced expiratory volume in one second (FEV1) and vital capacity (VC) declined at a significantly (p less than 0.001) faster rate in those who continued to smoke than in ex-smokers. No significant difference between the two groups was observed for kCO (permeability coefficient) and PaO2 (arterial oxygen tension). There was a significant (p less than 0.001) difference between the two groups in the annual change in body weight. We conclude that all patients with emphysema, even those with advanced disease, should be encouraged to stop smoking.

Albuterol↗
PubMed1981

The effects of salbutamol aerosol on lung function in patients with pulmonary emphysema.

The effects of inhaling 400 micrograms of salbutamol were compared with identical placebo inhaler in a double blind cross-over study of 20 patients with radiological evidence of pulmonary emphysema. There was a small but significant rise in the forced expiratory volume in one second (FEV1), but there was a much greater increase in vital capacity (VC), which was accompanied by a reduction in residual volume. Symptomatic improvement after salbutamol was reported by 14 of the patients and VC increased significantly in this group; there was no significant increase in VC in patients who did not prefer the active inhaler. There was no consistent change in the FEV1/VC ratio after salbutamol administration and this ratio is misleading as an indicator of bronchodilator responsiveness in patients with emphysema. Salbutamol is thus a valuable addition to treatment in patients with pulmonary emphysema and the response to treatment is best judged by measuring the improvement in VC.

Adult↗
PubMed1981

An accurate, long-term, pH-sensitive radio pill for ingestion and implantation.

The design of a new radiotelemetry capsule (26 mm long X 7.6 mm diameter), with an in vivo life of 1 month is described in the context of previous work in this field. In vitro evaluation of the capsule indicates an accuracy and performance comparable with a conventional pH meter. Several clinical applications are described, including measurements of gastrointestinal pH in humans and the measurement of extracellular pH in laboratory animals.

Animals↗
PubMed1980

Asthma induced by enkephalin.

A total of 291 diabetics were studied to see whether an asthmatic reaction was associated with facial flushing induced by chlorpropamide and alcohol. Of these patients, 191 reported facial flushing, of whom 12 reported breathlessness as well. Of these 12, five also described wheezing, and respiratory function tests showed them to have asthma. Three of these five patients underwent further tests, which showed that the asthmatic reaction could be prevented by giving disodium cromoglycate and the specific opiate antagonist naloxone. One patient developed wheezing when given an enkephalin analogue with opiate-like activity. Asthma induced by chlorpropamide and alcohol was concluded to be mediated by endogenous peptides with opiate-like activity such as enkephalin.

Asthma↗
PubMed1979

Combined autoradiography and histochemistry: the simultaneous detection of 6-3H thymidine and acid phosphatase activity in cryostate sections.

A method is described for the simultaneous demonstration of 6-3H thymidine incorporation and acid phosphatase activity in cryostae sections of mouse thymus. The method enables a comparison of mitosis and acid hydrolase activity to be made in the same tissue section. In 8-week-old mice acid phosphatase positive cells reprsent 1.23 +/- 0.06% of the total population and 8.4 +/- 0.27% of the cells incorporate tritiated thymidine. Acid phosphatase activity can be used to estimate cell autolysis and death. The implication of the method in relation to tissue dynamics is discussed.

Acid Phosphatase↗
PubMed1979

"Acute" asthma in adults.

Forty-four adult patients with acute severe asthma were studied on admission to a general hospital to determine the mode of presentation and clinical severity of the acute illness. Most patients described poorly controlled wheezing for a mean period of five weeks before a more rapid deterioration, usually over 24 hours, caused them to seek medical attention. The clinical severity of the acute attach was not related to the duration of acute wheezing before admission to hospital. Recovery, studied in 11 of the patients, was slow, and most had reached only 70% of their predicted spirometric values after seven days' treatment in hospital. The rate of recovery was not influenced by the antecedent history of acute wheezing. Very sudden deterioration from a background of good control appears to be uncommon in adults with asthma who present to hospital as emergencies, and it is likely that improvement in the standard of routine management of asthmatics at home would prevent many such admissions.

Acute Disease↗