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Biomedical subjects

R Stanton

Publications and source records attributed to R Stanton.

At least 19 recordsLinked to original sources
PubMed2001

Elucidating the nature of enzyme catalysis utilizing a new twist on an old methodology: quantum mechanical-free energy calculations on chemical reactions in enzymes and in aqueous solution.

How do enzymes achieve very large rate enhancements compared to corresponding uncatalyzed reactions in solution? We present a computational approach which combines high-level ab initio quantum mechanical calculations with classical free energy calculations to address this question. Our calculations lead to accurate estimates of DeltaG for both trypsin and catechol O-methyltransferase-catalyzed and reference uncatalyzed reactions and give new insights into the nature of enzyme catalysis. The same methodology applied to steps in the catalytic mechanism of citrate synthase further supports the conclusion that one need not invoke special concepts such as "low-barrier hydrogen bonds" or "pK(a) matching" to explain enzyme catalysis.

Catalysis↗
PubMed2001

Initial experience of vocal cord evaluation using grey-scale, real-time, B-mode ultrasound.

BACKGROUND: To evaluate whether grey-scale, real-time, B-mode ultrasound (US) is a reliable alternative to nasopharyngoscopy for assessing vocal cord function post-thyroid and post-parathyroid surgery. METHODS: A prospective validation study was undertaken comparing grey-scale, real-time, B-mode vocal cord US with the standard of nasopharyngoscopy in 100 consecutive patients undergoing thyroid and parathyroid surgery between 1 February 1999 and 31 August 1999, with seven patients with known cord palsy. The sensitivity and specificity of grey-scale, real-time vocal cord US for the detection of vocal cord palsy when compared to the standard of nasopharyngoscopy was analysed. RESULTS: In the postsurgical group, there were six nerves (3.2% of the nerves at risk) transient and no permanent vocal cord palsies. US identified four of six transient palsies and reported two false negatives and three false positives. US identified four of seven cord palsies in the non-surgical group with known cord palsy. Analysis of the 107 combined patients showed US had sensitivity of 62% (8/13), specificity of 97% (91/94), a positive predictive value of 73% (8/11) and a negative predictive value of 95% (91/96) for detecting cord paralysis compared to the standard of nasopharyngoscopy. CONCLUSION: Despite the enthusiasm of earlier reports, our initial experience with grey-scale, real-time, B-mode US suggests it is not a reliable alternative to nasopharyngoscopy for assessing vocal cord function post-thyroid and post-parathyroid surgery. Further recruitment of patients with known vocal cord palsy is required to confirm or refute these initial impressions.

Female↗
PubMed2000

Heartburn: community perceptions.

BACKGROUND AND AIMS: To determine the prevalence of heartburn in the Australian community, and document factors precipitating it and medications used in treatment. METHODS: Telephone interviews with 1200 individuals aged 18 years or more were conducted one weekend in 1996. Each respondent was asked four questions about heartburn, its severity, factors causing it and current therapy. RESULTS: Fifty-six per cent of respondents reported that they had suffered from heartburn at some time in the past and 37% had symptoms at least once every 4-6 months. The frequency of heartburn increased with age and was more common in men (40.7%) than women (32.6%). There was no difference in frequency between city and rural dwellers, or between white- and blue-collar workers. Almost half the individuals experienced mild pain or discomfort, one-third had moderate discomfort and 15% reported severe pain or discomfort. Women were more likely to report greater problems than men. Aggravating factors included spicy foods, greasy/rich foods, stress, alcohol, overeating, pregnancy, smoking, food allergy and coffee. More than half the respondents relied on antacids to control symptoms, 20% used prescription medications and a similar number did not use any medication. CONCLUSION: Heartburn is common in the Australian community and sufferers attribute symptoms to various lifestyle events, including diet and stress. Antacid usage is the commonest mode of therapy.

Adolescent↗
PubMed2000

Kinanthropometric and physiological characteristics of outrigger canoe paddlers.

We describe the physiological characteristics of amateur outrigger canoe paddlers. Twenty-one paddlers (13 males, 8 females) were evaluated for body stature, aerobic power, muscular strength and endurance, peak paddle force, flexibility and 250 m sprint paddle performance at the end of the outrigging season. The mean variables (+/- s) for the males were: age 27 +/- 9 years, height 175 +/- 5 cm, body mass 80 +/- 5 kg, arm span 178 +/- 7 cm, sitting height 100 +/- 2 cm, aerobic power 3.0 +/- 0.4 l x min(-1), maximum bench press strength 85 +/- 19 kg, right peak paddle force 382 +/- 66 N and left peak paddle force 369 +/- 69 N. For the females, these were: age 26 +/- 6 years, height 168 +/- 5 cm, body mass 70 +/- 8 kg, arm span 170 +/- 5 cm, sitting height 97 +/- 3 cm, aerobic power 2.3 +/- 0.51 l x min(-1), maximum bench press strength 47 +/- 10 kg, right peak paddle force 252 +/- 63 N and left peak paddle force 257 +/- 60 N. Analysis of variance revealed differences (P < 0.05) between the dominant and non-dominant sides of the body for peak paddle force, isokinetic internal and external rotation, and flexion and extension torque of the shoulder joint. The outrigger canoe paddlers were generally within the range of scores found to describe participants of other water craft sports. Outrigger canoeists should be concerned with the muscular strength imbalances associated with paddling technique.

Adult↗
PubMed1998

Leakage via aberrant bile duct due to cholangiocarcinoma.

The case of a male who had an open cholecystectomy complicated by persistent bile leak from an aberrant bile duct is presented. The persistence and volume of bile leak resulted in subsequent investigation of the biliary tree which demonstrated a cholangiocarcinoma of the right hepatic duct. This case is presented as an unusual presentation of cholangiocarcinoma and to highlight the value of modern techniques in imaging the biliary tree.

Aged↗
PubMed1997

Suicide among psychiatric in-patients in a changing clinical scene. Suicidal ideation as a paramount index of short-term risk.

BACKGROUND: Rapid changes in styles of clinical practice mean that we should carefully monitor the way suicides occur among psychiatric patients both in hospital and in the wider community. METHOD: Patients who had died through suicide either while receiving in-patient care or within 2 months of discharge from hospital were compared with a similar series reported 10 years previously. Clinicians' perceptions of patients' behaviour were compared with concurrent controls. RESULTS: Patients in the more recent study were younger, more often male, and a greater proportion had been discharged from in-patient status. Hazards which complicated risk assessment included short-lasting misleading clinical improvements, variability in degree of distress, and a reluctance to discuss suicidal ideas. Over a range of perceived behaviours it was not possible to distinguish suicides from controls. CONCLUSIONS: In assessing suicide risk paramount importance should be attached to monitoring suicidal ideation and addressing the several hazards which might complicate this procedure.

Adult↗
PubMed1997

Mesenchymal chondrosarcoma of the cervical spine in a child.

Mesenchymal chondrosarcoma is a rare small-cell neoplasm of bone and soft tissue. After reviewing the literature, we believe that the patient in this report is the youngest in whom mesenchymal chondrosarcoma originating in a cervical vertebra has been diagnosed.

Cervical Vertebrae↗
PubMed1996

Can a lecture influence attitudes to suicide prevention?

Attitudes held by various groups of healthcare professionals with regard to suicide prevention were assessed using an attitude inventory before and after they attended a formal lecture. The lecture presented basic facts and statistics, discussed clinical techniques and challenged negative attitudes. Evidence is presented to suggest that a reduction in the proportion of expressed attitudes which were equivocal or negative towards the feasibility of suicide prevention in clinical practice, can be achieved by a lecture of this kind.

Attitude of Health Personnel↗
PubMed1996

Paediatric dentistry--what's new. Paediatric dentistry and diet.

Many children are given so many soft, easy-to-swallow foods that they do not learn to chew. This affects not only their dental development but also their health. Up to one-third of Australian children are overweight and 50 per cent of 10-15 year olds have high levels of serum cholesterol. It's time to encourage children to eat fewer soft, fatty, sugary foods and more fruits, vegetables, chewy breads, and grain-based foods. This paper aims to show that the diet that is good for children's teeth is also good for their health.

Australia↗
PubMed1992

Adenosine in the treatment of paroxysmal supraventricular tachycardia in children.

Intravenous bolus adenosine was given to four pediatric patients aged 1 month to 8 years who had paroxysmal supraventricular tachycardia that had not responded to conventional medical therapy. Adenosine (one to three doses) was successful in converting the arrhythmia to normal sinus rhythm in all four cases, and no side effects of the drug were noted.

Adenosine↗
PubMed1991

Behavioural psychotherapy in the treatment of irritable bowel syndrome.

The irritable bowel syndrome is a highly prevalent condition whose underlying aetiology is not understood. While many patients respond to a combination of gastrointestinal antispasmodics, bulking agents and dietary manipulation, controlled clinical trials have suggested that the benefit is only marginal and is due mainly to the large placebo effect found in this condition, which has been calculated to range between 54 and 81%. Associations between the syndrome and psychological and social stresses suggest, however, that treatment involving a systematic approach to the management of symptoms may hold out real therapeutic possibilities. In the current study, 42 IBS patients were randomly allocated to either medical treatment or to behavioural psychotherapy with a nurse therapist. They were assessed initially and at 4 and 9 months. There was a general improvement over the 9 months on a number of physical and psychological symptoms measured. However, no differences were found between treatment groups except for changes in two avoidance scores. A significant correlation was found, however, between improvement in the bowel symptoms of IBS (stomach pain and diarrhoea) and improvement in the psychological symptoms measured by the Clinical Interview Schedule, suggesting a close interrelationship between the two.

Adult↗
PubMed1991

A survey of 658 women who report symptoms of premenstrual syndrome.

A treatment trial was briefly mentioned in two British publications and women suffering from premenstrual syndrome were invited to write to us. After initial screening, postal questionnaires were sent to all eligible women. Six-hundred and ninety-nine questionnaires were returned and of these 658 were included in the analyses. Although the results of the study need to be considered cautiously because of the unrepresentative nature of the sample, the survey was helpful in ascertaining the views of women who report PMS symptoms and what they had found helpful. The majority of respondents were aged in their 30s and were married with children. Over 60% were chronic sufferers, having had symptoms for 5 years or more. High proportions of the women experienced both psychological and somatic symptoms but it was the psychological symptoms which were perceived as the most distressing. Over 60% of the sample were ascertained as suffering from some degree of psychological distress and the same proportion had one or more social problems. Overall 84% had visited their GP for this problem and many had also visited gynaecologists, family planning clinicians and psychiatrists. Agencies offering alternative medicine were also frequently contacted and often found more helpful. Most women had tried more than one type of medication but no one treatment was found to be particularly helpful.

Female↗
PubMed1991

Dosimetric considerations in the choice of photon energy for external beam radiation therapy: clinical examples.

Laughlin, Mohan, and Kutcher have evaluated photon beams for Co-60 through 24 MV for eight clinical disease sites plus pediatrics and concluded that two energy ranges are required for the best patient care: a 4 to 6 MV beam and a 10 to 18 MV beam. The present study investigates the question which two energies in a dual energy machine are optimum for the average patient mix. The method used is to calculate two dimensional sample cases including breast, head and neck, and pelvic tumors on the same treatment planning system using machine data including Co-60, 4 MV, 6 MV, 10 MV, and 18 MV x-ray beams. The resulting plans were evaluated considering tumor doses, spinal cord doses, doses to subcutaneous tissues and doses to other radiosensitive structures. The conclusion is that the optimum two beams are 6 and 10 MV.

Cobalt Radioisotopes↗
PubMed1990

Physical symptom severity, psychological and social dysfunction in a series of outpatients with irritable bowel syndrome.

Details of physical symptoms, psychological and social dysfunction of 42 outpatients diagnosed as having irritable bowel syndrome (IBS) were collected by interview and questionnaire. Social stresses and problems were also elicited as well as the impact of symptoms on their subjects' daily lives. High proportions of subjects were handicapped in their social, sexual and working lives by IBS symptoms and social stresses and problems were common. Forty-eight per cent were classified as having a 'minor psychiatric illness' using the Clinical Psychiatric Interview. Women were more severely affected by physical symptoms (with the exception of diarrhoea) and were more likely to be in pain longer and for more days in the month. They were also more likely than men to be diagnosed as having a psychiatric illness.

Activities of Daily Living↗