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Biomedical subjects

R A Cooke

Publications and source records attributed to R A Cooke.

At least 19 recordsLinked to original sources
PubMed1999

Primary osteogenic sarcoma of the tongue.

A 56-year-old man presented with the difficulty of swallowing and respiratory distress due to a large tumour arising from the tongue and occupying the entire oral cavity. Histological examination revealed it to be an extraskeletal osteogenic sarcoma. The tumour was excised. After six weeks, he came back with massive local recurrence and bleeding from the tumour, but died despite chemotherapy. Review of the literature revealed only four other such cases of this rare tumour. A brief review of these four cases is also made.

Fatal Outcome↗
PubMed1998

Hepatitis B--are surgeons putting patients at risk?

The 1993 Department of Health guidelines permit a surgeon who is hepatitis B surface antigen (HBsAg) positive but e-antigen (HBeAg) negative to perform exposure prone procedures, unless demonstrated to have infected patients. However, there is increasing evidence of transmission of hepatitis B to patients from health care workers in this supposedly low infectivity category. The Occupational Physician must decide whether existing guidelines represent an adequate risk assessment and indeed whether this is an acceptable risk for patients. If an NHS Trust continues to follow these guidelines it may be in breach of its duty of care to patients. Yet refusing to allow such carriers to operate without testing for additional serological markers may be unlawful discrimination. Further research is clearly needed as well as an urgent review of the guidelines.

Biomarkers↗
PubMed1998

A prospective study of oesophageal function in patients with normal coronary angiograms and controls with angina.

AIMS: To compare the incidence of oesophageal abnormalities and their correlation with chest pain in patients with normal coronary angiograms, and in controls with angina. PATIENTS: Sixty one patients with normal coronary angiograms (NCA group) referred to a single cardiac centre between March 1990 and April 1991; 25 matched controls with confirmed coronary artery disease (CAD group). SETTING: Cardiac referral centre and oesophageal function testing laboratory. MAIN OUTCOME MEASURES: Oesophageal manometry, provocation tests, and 24 hour ambulatory pH monitoring. RESULTS: Simultaneous contractions were more common (6.7% versus 0.8%, p < 0.01), and the duration of peristaltic contractions was longer (2.9 versus 2.4 seconds, p < 0.01) in the NCA group than in the CAD group. There were no group differences in the amplitude of peristaltic contractions, and none had nutcracker oesophagus. Ten (16%) patients with NCA and no patients with CAD had diffuse spasm (p = 0.03). Twenty one (34%) patients with NCA, and five (20%) patients with CAD had abnormal gastro-oesophageal reflux (p > 0.05). There was no significant difference between the groups in the number of patients whose pain was temporally related to pH events. Particular chest pain characteristics, or the presence of additional oesophageal symptoms, were not predictive of an oesophageal abnormality. CONCLUSION: Oesophageal function tests commonly implicate the oesophagus as a source of pain in patients with normal coronary angiograms. With the exception of simultaneous contractions during manometry however, the incidence of abnormalities and in particular the correlation of pH events with chest pain are as common in patients with normal coronary angiograms as in controls with angina. The oesophagus may often be an unrecognised source of pain in both groups of patients.

Angina Pectoris↗
PubMed1997

Haemodynamic changes during dobutamine stress echocardiography in patients with and without ischaemia.

We studied haemodynamic changes during dobutamine stress echocardiography in 69 patients (mean age 58 years, 6 female, 63 male) referred for investigation of chest pain. We used a standard protocol of 3 min stages using infusion rates of 5, 10, 20, 30 and 40 micrograms/kg/min. Heart rate rose from 74 (13) to 123 (21) beats per min with the major increment occurring during the high dose phase of the study (> 20 micrograms/kg/min). Stroke volume was calculated as the product of left ventricular outflow tract cross-sectional area and the velocity integral of the continuous wave aortic signal. Mean stroke volume increased from 67.5 (22) ml pre-test to 82 (22) ml at 20 micrograms/kg/min dose (P < 0.0001) and 85 (21) ml at 40 micrograms/kg/min (P < 0.00001). Only 15 patients (26%) reached their maximal stroke volume by 10 micrograms/kg/min, 38 patients (65%) reached maximal stroke volume by 20 micrograms/kg/min. Patients with ischaemic responses tended to have a blunted rise in stroke volume from 67 (22) ml to 85 (22) ml at maximum compared with a rise from 69 (23) to 92 (19) ml in those without ischaemic (P = 0.09). In conclusion, the early rise in cardiac output during dobutamine stress was mainly due to a rise in stroke volume and the later due to an increase in heart rate. Individual increases in stroke volume did not adequately differentiate between ischaemic and non-ischaemic results.

Adult↗
PubMed1997

Comparative study of chest pain characteristics in patients with normal and abnormal coronary angiograms.

OBJECTIVE: To improve the characterisation of chest pain by comparing symptoms in patients with normal and abnormal coronary angiograms. STUDY DESIGN: Prospective case-control study. SETTING: Single tertiary cardiac referral centre. PATIENTS: 65 consecutive patients with chest pain and completely normal coronary angiograms recruited over a period of one year, and 65 sex matched patients with significant stenoses at angiography. MAIN OUTCOME MEASURES: Standardised chest pain questionnaires. RESULTS: 61 of 65 patients (94%) and every control reported chest pain on exertion. There were no important differences in the site, quality, and radiation of pain but three symptoms had discriminatory value expressed in binary fashion ("typical" v "atypical"): the consistency with which pain was reproduced by exercise (typical, score index 10/10), the duration of pain episodes (typical, five minutes), and the frequency of pain at rest (typical, 10% all pain episodes). All three symptoms were atypical in 21 (32%) patients with normal coronary angiograms, but only one patient with an abnormal coronary angiogram. Patients with no typical features had a 2% chance of an abnormal coronary angiogram if aged under 55 years or 12% if aged 55 years or more. The additional impact of exercise stress testing was low. CONCLUSIONS: Chest pain characteristics which separate patients with normal coronary angiograms from patients with obstructive coronary heart disease can be defined objectively. This may allow improvements in referral patterns for specialist opinion or angiography, and in characterisation of patients in research studies.

Age Factors↗
PubMed1996

Malignant lymphomas in Papua New Guinea: an immunohistological study of 125 cases.

A total of 179 cases of lymphoma, both nodal and extranodal, recorded in the Papua New Guinea Tumor Registry were reviewed and classified by the updated Kiel classification. Fifteen (8.4%) were Hodgkin's disease, 39 (21.8%) probable Burkitt's lymphoma (poorly preserved), 46 (25.7%) Burkitt's lymphoma, 33 (18.4%) Burkitt's-like lymphoma, 36 (20.1%) other B-cell subtypes and 10 (5.6%) T-cell lymphoma. No case of follicular B-cell lymphoma was encountered.

Humans↗
PubMed1996

Essential acquired cold urticaria: stimulated only by systemic as well as local cooling.

The background and differential diagnosis of essential acquired cold urticaria are discussed. The case report is of a 22-year old male who had previously been diagnosed as suffering from eczema. Working in a cold environment, with both systemic and local cooling stimulated development of an urticaria rash, diagnosed as being essential acquired cold urticaria.

Adult↗
PubMed1996

Hyperventilation and esophageal dysmotility in patients with noncardiac chest pain.

OBJECTIVES: Hyperventilation is known to cause esophageal spasm, but the importance of this interaction in clinical practice is unknown. In the present study, we report the effects of hyperventilation provocation on esophageal motility in a consecutive series of patients with noncardiac chest pain. METHODS: In a prospective observational study design, 46 consecutive patients with normal coronary angiograms were studied. Esophageal motility was recorded at rest and after voluntary over-breathing at 40 breaths/min for 3 min. RESULTS: Hyperventilation was associated with a significant fall in mean distal peristaltic amplitude [66 (SD 28) to 55 (SD 24) mm Hg, p <0.001] and mean duration [2.9 (SD 0.7) to 2.6 (SD 0.9) s,p = 0.02]. It induced diffuse spasm in two (4%) patients, and nonspecific motility disorders in 10 (22%). Chest pain was reproduced in seven (15%) patients, but in none did this coincide with an important change in peristaltic amplitude, duration, or frequency. CONCLUSION: Hyperventilation has important effects on esophageal motility, and manometrists should be aware of these before recommending that anxious patients overbreathe to help relaxation during clinical studies. Although overbreathing is a common source of dysmotility, it rarely produces chest pain via its effects on the esophagus.

Breath Tests↗
PubMed1996

A comparison of valve resistance, the continuity equation, and the Gorlin formula against directly observed orifice area in bioprosthetic valves in the mitral position: an in vitro study.

BACKGROUND AND AIMS OF THE STUDY: There is no consensus over how to describe forward flow through valves in the mitral position. There are three main candidate hydraulic formulae; resistance, the Gorlin formula and the continuity equation. However, virtually no work has been performed to validate resistance and the continuity equation for valves in the mitral position. The aim of this study, therefore, was to compare the three formulae against an independent standard provided by directly observed orifice areas. MATERIALS AND METHODS: Five bioprosthetic valves with orifice areas between 0.14 cm2 and 2.33 cm2 were studied in a pulse simulator at up to 20 different stroke volume/rate combinations using quasi-physiologic flow curves. Orifice areas were measured using a video camera, pressure difference using strain gauge transducers and Doppler signals using a 1.9 MHz Pedoff probe with a Vingmed SD50 system. RESULTS: The Gorlin ratio (flow/square root of mean delta P) had a direct curvilinear relationship with the orifice area (log(y) = 0.31 + 0.36x; r = 0.94, SEE 0.08 cm2, p < 0.0001). Resistance (mean delta P/flow) had an indirect curvilinear relationship (log(y) = 0.19 - 0.55x, r = -0.93, SEE 0.13 cm2, p < 0.0001). The continuity equation was directly related to observed orifice area although with high scatter (y = 1.13 + 0.79x; r = 0.90, SEE 0.23 cm2, p < 0.0001). Although both the Gorlin ratio and resistance changed with flow, there was also a tendency for observed orifice areas to increase with flow. Empirical effective orifice areas calculated using the regression equations closely resembled observed orifice areas and agreement was reasonable, with 95% limits of -0.33 cm2 to +0.33 cm2 (Gorlin), -0.41 cm2 to +0.42 cm2 (resistance) and -0.40 cm2 to +0.48 cm2 (continuity). CONCLUSION: In conclusion, no single formula adequately predicted all observed orifice areas although resistance and the Gorlin formula gave useful predictions after empirical correction.

Bioprosthesis↗
PubMed1995

Liver disease in Papua New Guinea 1981 to 1988, twenty years after the first surveys were done.

Twenty years after the first surveys of liver disease were done cirrhosis and hepatocellular carcinoma were still found to be the most important liver diseases in Papua New Guinea. Hepatitis B virus appears to be the main cause of both these conditions. Data from a number of different sources suggest a prevalence of hepatitis B positivity of about 17%. The most significant new finding was grade 3 iron deposition in 8 patients. This raises the question as to whether iron storage disease may now contribute to the spectrum of liver disease in Papua New Guinea. Many biopsies in the 1960s and 1980s were interpreted as nonspecific hepatitis; in the light of recent observations, at least some of these may have been due to hepatitis C infection.

Adolescent↗
PubMed1994

Percutaneous transluminal coronary angioplasty in patients with prior coronary artery bypass grafting: ten years' experience.

We evaluated the acute and long-term results of percutaneous transluminal coronary angioplasty in 140 patients with prior coronary artery bypass grafting treated over a 10-year period (1981-1991). Angioplasty was technically successful in 85% of 122 nonoccluded native vessels and in 86% of 50 saphenous vein grafts. Two patients (1.4%) had a myocardial infarction and there were three procedure-related deaths (2.1%). The cumulative probability of survival was 91.5% and 74.5% at 1 and 5 years, respectively. Survival free from myocardial infarction and repeat bypass grafting at 1 and 5 years was 77.3% and 53.9%, respectively. At census, 31% of the 117 survivors were asymptomatic, and 47% were improved by at least two angina grades. Coronary angioplasty provides an apparently safe and effective alternative method of revascularization in selected patients with prior coronary artery bypass grafting. This treatment strategy potentially avoids reoperation with its attendant risks.

Adult↗
PubMed1994

Noonan's cardiomyopathy: a non-hypertrophic variant.

OBJECTIVE: To describe the association of the Noonan's phenotype and a primary, familial non-hypertrophic cardiomyopathy with restrictive pathophysiology. DESIGN: Observational study. SETTING: Tertiary cardiac referral centre. PATIENTS: Affected family members. METHODS: Two generations of a single family were examined and a description of the clinical characteristics and electrocardiographic, echocardiographic, and haemodynamic data of those affected is given. RESULTS: Three family members have classic Noonan's phenotype and all have a non-dilated, non-hypertrophic cardiomyopathy. Inheritance is autosomal dominant but with variable penetrance. The electrocardiograms show increased left ventricular voltages in two patients. On echocardiography left ventricular wall and internal end diastolic dimensions are normal, and there is considerable bilateral atrial enlargement. Systolic function is moderately impaired in one patient and mildly impaired in another. Doppler echocardiography showed restrictive pathophysiology as an early end of left ventricular filling and considerable reversal of flow in the superior vena cava during atrial systole. CONCLUSION: Hypertrophic cardiomyopathy is well described in Noonan's syndrome. This is the first report of a non-hypertrophic cardiomyopathy with echocardiographic and haemodynamic features of restrictive pathophysiology.

Adult↗
PubMed1994

QT interval in anorexia nervosa.

OBJECTIVES: To determine the incidence of a long QT interval as a marker for sudden death in patients with anorexia nervosa and to assess the effect of refeeding. To define a long QT interval by linear regression analysis and estimation of the upper limit of the confidence interval (95% CI) and to compare this with the commonly used Bazett rate correction formula. DESIGN: Prospective case control study. SETTING: Tertiary referral unit for eating disorders. SUBJECTS: 41 consecutive patients with anorexia nervosa admitted over an 18 month period. 28 age and sex matched normal controls. MAIN OUTCOME MEASURES: maximum QT interval measured on 12 lead electrocardiograms. RESULTS: 43.6% of the variability in the QT interval was explained by heart rate alone (p < 0.00001) and group analysis contributed a further 5.9% (p = 0.004). In 6 (15%) patients the QT interval was above the upper limit of the 95% CI for the prediction based on the control equation (NS). Two patients died suddenly; both had a QT interval at or above the upper limit of the 95% CI. In patients who reached their target weights the QT interval was significantly shorter (median 9.8 ms; p = 0.04) relative to the upper limit of the 60% CI of the control regression line, which best discriminated between patients and controls. The median Bazett rate corrected QT interval (QTc) in patients and controls was 435 v 405 ms.s-1/2 (p = 0.0004), and before and after refeeding it was 435 v 432 ms.s1/2 (NS). In 14(34%) patients and three (11%) controls the QTc was > 440 ms.s-1/2 (p = 0.053). CONCLUSIONS: The QT interval was longer in patients with anorexia nervosa than in age and sex matched controls, and there was a significant tendency to reversion to normal after refeeding. The Bazett rate correction formula overestimated the number of patients with QT prolongation and also did not show an improvement with refeeding.

Adolescent↗
PubMed1994

Gastroesophageal reflux in patients with angiographically normal coronary arteries: an uncommon cause of exertional chest pain.

OBJECTIVES: To investigate the association between exertional chest pain and gastroesophageal reflux in patients with normal coronary angiograms and in controls by measuring oesophageal pH during treadmill exercise tests and to compare the results with routine ambulatory monitoring. DESIGN: Case control study. SETTING: Tertiary referral cardiac unit. PATIENTS: 50 consecutive patients with chest pain and completely normal coronary angiograms and 16 controls with coronary artery stenoses. MAIN OUTCOME MEASURES: Episodes of acid reflux and chest pain during treadmill exercise; a symptom index expressing the percentage of episodes of pain related to acid reflux during ambulatory monitoring. RESULTS: Four (8%) patients and two (12%) controls had reflux during treadmill exercise (NS). 32 (64%) and 16 (100%) reported chest pain, but only three (6%) and two (12%) had coincident reflux (NS). Reflux was as frequent before, during, and after treadmill exercise (five (8%) v six (9%) v two (3%)) in the 66 subjects; (NS). 19 (38%) patients and three (19%) controls had abnormal reflux on ambulatory monitoring (NS). Eight (16%) and three (19%) had a symptom index > 50%, but six and two of these reported pain without coincident reflux during treadmill exercise. CONCLUSION: There are many potential causes of chest pain in patients with angiographically normal coronary arteries. Although gastroesophageal reflux is commonly implicated and many patients have a high incidence of spontaneous reflux during ambulatory monitoring, it rarely occurs during exertion and the association with chest pain is poor.

Adult↗
PubMed1993

Caring for children with chronic illness.

This article has outlined some factors to consider in designing services for chronically ill children and their families. The most important factors are ensuring coordination and communication among providers, meeting the psychosocial needs of patients and families, and designing a child-friendly outpatient environment. In going beyond the suggestions outlined here, do not be afraid of trying new ideas even if it means making mistakes. When the oncology clinic at The Children's Hospital of Philadelphia moved to its present location in the fall of 1989, one of the new spaces that had been designed was a parent lounge adjacent to the day hospital. The aim was to provide a place for parents to relax while their children were receiving treatment. The parent lounge was a large room with windows, comfortable furniture, and a television set. When the parent lounge was not used, it became clear that parents were unwilling to leave their children while they were undergoing treatment. Sometimes the only way to discover whether an idea will work is to try it and find out from children and their families whether or not it best serves their needs.

Child↗