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Biomedical subjects

N Tait

Publications and source records attributed to N Tait.

At least 19 recordsLinked to original sources

Clinician opinion on the management of patients with hepatic colorectal metastases.

BACKGROUND AND AIMS: Clinical practice is determined by many different factors, but with the advent of evidence-based medicine, there may be a tendency to concentrate upon the scientific facts when decision-making rather than focusing on the patient. Furthermore, individual clinician opinion or bias may potentially influence patient management. This study outlines clinician opinion with regard to management of patients with hepatic colorectal metastases, and compares it to present practice in the Sydney metropolitan area. METHODS: Clinician opinion was assessed by using a questionnaire and compared to results from a prospective multicenter study looking at patterns of care of patients with hepatic colorectal metastases. RESULTS: Clinicians participating in the present study had a good knowledge of the current evidence concerning hepatic colorectal metastases and its treatment. However, there was a discrepancy between clinician knowledge that matched scientific evidence and actual clinical practice. CONCLUSIONS: This study suggests that clinician bias/opinion does influence patterns of care for patients with hepatic colorectal metastases.

Chi-Square Distribution↗

Implementing clinical practice guidelines: a community-based audit of breast cancer treatment. Australian Capital Territory and South Eastern New South Wales Breast Cancer Treatment Group.

OBJECTIVE: To improve breast cancer management by facilitating implementation of treatment guidelines. DESIGN: A prospective, longitudinal study (developed by clinicians and consumers) of all patients with newly diagnosed breast cancer. Four locally agreed breast cancer management guidelines were established (based on 1995 National Health and Medical Research Council guidelines) as practice indicators. SETTING: Breast cancer treatment facilities and medical practices in the Australian Capital Territory and South Eastern New South Wales, May 1997 to July 1998. MAIN OUTCOME MEASURES: Actual treatment received by patients for primary breast cancer during the study period. RESULTS: During the 14 months of the study, 19 clinicians registered 221 new patients with a proven diagnosis of breast cancer. Of 191 women with localised invasive breast cancer, 112 (59%) had tumours 2 cm or less in diameter. Axillary surgery in 173 (91%) of these women showed 107 (56%) had no axillary lymph node involvement. Of 87 women treated with breast-conserving surgery for locally invasive cancer, 85 (98%) also received postoperative radiotherapy. Some form of systemic adjuvant therapy was indicated in 99 women (axillary nodes positive or tumours > 2 cm diameter) and this treatment was received by 95 (96%). All 27 women aged under 50 years with node-positive disease received adjuvant chemotherapy. CONCLUSIONS: Enhancing uptake of breast cancer management guidelines is feasible at a regional level with an audit program and broad support among clinicians and consumers.

Adult↗

Use of the Hasson cannula producing major vascular injury at laparoscopy.

Despite the recent demonstration that vascular lesions occur significantly more frequently in patients having closed rather than "open" laparoscopy, there never has been a published case report of injury to the great vessels associated with the open technique of initial access to the peritoneal cavity at laparoscopy. We present the first two such cases reported, along with a brief review of the literature related to such major vascular injuries (MVI) sustained at laparoscopy. Lacking appreciation of aortic anatomy and intraoperative technical factors contribute to the occurrence of these injuries. Delayed diagnosis and management contribute to poor outcomes. Secondary injury frequently is associated with MVI at laparoscopy.

Adult↗

Fabrication of nanocolumns for liquid chromatography.

This paper shows that in situ micromachining can be used to simultaneously position and define (i) support particles, (ii) convective transport channels, (iii) an inlet distribution network of channels, and (iv) outlet channels in multiple chromatography columns on a single quartz wafer to the level of a few tenths of a micrometer. Stationary phases were bonded to 5 x 5 x 10 microns collocated monolith support structures separated by rectangular channels 1.5 microns wide and 10 microns deep with a low degree of deviation of channel width between the top and bottom of channels. High aspect ratio microfabrication can only be achieved with deep reactive ion etching. The volume of a 150 microns x 4.5 cm column was 18 nL. Column efficiency was evaluated in the capillary electrochromatography (CEC) mode using rhodamine 123 and a hydrocarbon stationary phase. Plate heights in these columns were typically 0.6 micron in the nonretained and 1.3 microns in the retained modes of operation. Columns were designed to have identical mobile-phase velocity in all channels in an effort to minimize outgassing during operation. When the total lateral cross-sectional area of channels at all points along the separation axis is identical, linear velocity of the mobile phase in a CEC column should be the same. Columns were operated at atmospheric pressure.

Chromatography, Liquid↗

Phase I study of the orally administered butyrate prodrug, tributyrin, in patients with solid tumors.

Butyrates have been studied as cancer differentiation agents in vitro and as a treatment for hemoglobinopathies. Tributyrin, a triglyceride with butyrate molecules esterified at the 1, 2, and 3 positions, induces differentiation and/or growth inhibition of a number of cell lines in vitro. When given p.o. to rodents, tributyrin produces substantial plasma butyrate concentrations. We treated 13 patients with escalating doses of tributyrin from 50 to 400 mg/kg/day. Doses were administered p.o. after an overnight fast, once daily for 3 weeks, followed by a 1-week rest. Intrapatient dose escalation occurred after two courses without toxicity greater than grade 2. The time course of butyrate in plasma was assessed on days 1 and 15 and after any dose escalation. Grade 3 toxicities consisted of nausea, vomiting, and myalgia. Grades 1 and 2 toxicities included diarrhea, headache, abdominal cramping, nausea, anemia, constipation, azotemia, lightheadedness, fatigue, rash, alopecia, odor, dysphoria, and clumsiness. There was no consistent increase in hemoglobin F with tributyrin treatment. Peak plasma butyrate concentrations occurred between 0.25 and 3 h after dose, increased with dose, and ranged from 0 to 0.45 mM. Peak concentrations did not increase in three patients who had dose escalation. Butyrate pharmacokinetics were not different on days 1 and 15. Because peak plasma concentrations near those effective in vitro (0.5-1 mM) were achieved, but butyrate disappeared from plasma by 5 h after dose, we are now pursuing dose escalation with dosing three times daily, beginning at a dose of 450 mg/kg/day.

Administration, Oral↗

Use of spiral and non-spiral computed tomography arterial portography in the detection of potentially malignant liver masses.

The present study assesses the usefulness of computed tomography (CT) arterial portography (CTAP) in detecting and defining the number and anatomy of potentially malignant liver lesions. One hundred and one adults studied in 1993 and 1994 were retrospectively reviewed, including patients with primary or secondary tumours for possible resection and patients with non-hepatic malignancies in whom the detection of liver metastases would preclude surgery. Twenty-three patients underwent non-spiral CT studies and 78 had studies on a spiral unit, with 22 of these having single phase and 56 having dual phase studies to overcome artefact problems. The relationship between lesion size and detection sensitivity is critical. On non-spiral studies, the overall lesion detection sensitivity and positive predictive value was 69 and 90%, respectively. Detection sensitivity was 100 and 20% for lesions > 1 cm and < 1 cm, respectively. On single phase spiral CTAP the overall detection sensitivity and positive predictive value was 80 and 66%, respectively. Detection sensitivity for lesions > 1 cm and < 1 cm was 100 and 0%, respectively. On dual phase spiral CTAP the overall detection sensitivity and positive predictive value was 76 and 71%, respectively. For lesions > 1 cm and < 1 cm the sensitivity was 81 and 55%, respectively. Eighteen patients with non-hepatic malignancies with unsuspected metastatic spread did not proceed to major surgery because of liver metastases detected on CTAP. Perfusion artefacts occurred in 30 and 64% of non-spiral and of initial portal venous spiral CTAP studies, respectively. By using the double-phase technique, these artefacts were substantially diminished. In conclusion, CTAP is a valuable tool for assessing the presence, site and size of possible liver tumours and confers a benefit even when previous ultrasound and conventional CT have already been used. In addition, CTAP has a lower limit of useful resolution of approximately 1 cm. Perfusion artefacts can be reduced by a dual phase protocol.

Adult↗

Is an intercalated BSc degree associated with higher marks in examinations during the clinical years?

Do medical students taking an intercalated BSc degree obtain higher marks during their subsequent clinical examination? Fourteen students who did a BSc during the academic year 1988-89 were matched, by sex and preclinical grades, with students in the year they left, and with students in the year they subsequently joined. Marks or grades in 10 subsequent examinations were compared. Seven of 10 comparisons with the year the BSc students left were to the advantage of the intercalated students, and two comparisons were statistically significant. Seven of 10 comparisons with the year the BSc students subsequently joined were to the advantage of the non-intercalating students, though none reached statistical significance. No consistent short-term academic advantages arising from having done a BSc could be found. We suggest the study be replicated in other medical schools with different course examination structures.

Adult↗

Frantz's tumour: papillary and cystic carcinoma of the pancreas.

Frantz's tumour (papillary and cystic tumour) of the pancreas is a rare neoplasm usually seen in young women. It is of low grade malignancy and deserves special note among pancreatic malignancies as it is frequently amenable to local resection and has a good long-term survival rate after excision. Three such cases have been treated at Westmead Hospital, one young male and two females. In two the disease was confined to the pancreas. In one, local invasion outside the pancreas and trans-coelomic spread to the ovaries was present at the time of diagnosis. Complete surgical removal of macroscopic disease was achieved in all three and all remain disease free between 2 and 4 years post-surgery. All have good exocrine and endocrine pancreatic function. These cases are discussed in detail. The need to be aware of this uncommon variant of pancreatic cancer is stressed. Investigation and treatment options are reviewed. The role of cytology studies in diagnosis and the potential for long-term surgical control of this tumour are highlighted on the basis of our limited experience and that presented in recent surgical literature.

Adolescent↗

Oesophageal cancer: outcome of modern surgical management.

Many clinicians still associate oesophagectomy for oesophageal carcinoma with low cure rates, poor palliation and prohibitive peri-operative mortality. Surgical advances have rendered such perceptions inaccurate. A prospective study of all patients undergoing surgery for oesophageal cancer in an Australian teaching hospital between 1979 and 1993 has been undertaken. Selection, staging, pre-operative preparation, surgical technique and postoperative care were all carefully controlled. One hundred and thirty-seven patients were explored. Twenty-one were inoperable. One hundred and sixteen underwent resection with intent to cure. Hospital mortality for oesophagectomy was 1.7%. There were no cases of clinical anastomotic leakage. Eighty-nine per cent achieved excellent to good swallowing. The median survival for all cases was 14 months and the 5 year survival was 18%. Median survival for resected cases was 18 months and the 5 year survival was 26%. The long-term survival was related to postoperative stage of the disease but not to tumour type. Oesophagectomy for oesophageal cancer will restore good swallowing in 90% of cases. Operative mortality should be less than 5% and the overall 5 year survival 20-30%. Early tumours can often be cured (ca in situ 100%, stages I and II 50-60%), indicating the benefits of early detection. Poor survival in advanced disease (stage III 15%, stage IV 0%) on a background of low surgical mortality indicate the need for better staging and more effective adjuvant therapies.

Adenocarcinoma↗

Cold agglutinins: preoperative diagnosis leads to an uneventful perfusion.

This report presents the successful use of normothermic cardiopulmonary bypass (CPB) and warm continuous retrograde cardioplegia to facilitate coronary artery bypass grafting (CABG) in a patient with cold agglutinins. As a result of their agglutinating action and resultant haemolysis, cold-reactive autoantibodies have the potential for causing morbidity and mortality when a patient is placed on hypothermic CPB and the heart is arrested with profoundly cold cardioplegia. The crux of the situation is to keep the temperature above the critical temperature of the cold agglutinin; this technique guarantees accomplishing that goal.

Aged↗

Hepatocellular carcinoma in western Sydney. Aetiology, changes in incidence, and opportunities for better outcomes.

OBJECTIVES: To examine the incidence of hepatocellular carcinoma (HCC) in western Sydney over the last 14 years, to assess risk factors for the disease among ethnic groups of Australian residents, and to consider the opportunities for improving its usually poor outcome. DESIGN AND SUBJECTS: Retrospective case-record review of clinical features in all (122) patients discharged from a 900-bed tertiary-referral teaching hospital with a diagnosis of HCC from January 1979 to March 1993. MAIN OUTCOME MEASURES: Annual number of new cases; risk factors according to birthplace; surgical resectability of tumours. RESULTS: New cases admitted each year at least doubled between 1979-1985 and 1986-1992. This apparent increase involved individuals born in Australia (50% of all patients) as well as immigrants. Cirrhosis was found in 93% at liver biopsy or autopsy. Excessive alcohol intake was an associated risk factor for 46% of Australian-born patients and for 13% of those born overseas. Among the latter, HCC was associated with markers of hepatitis B virus infection in 64%. Since hepatitis C virus (HCV) tests became available in 1990, five of nine patients tested were anti-HCV positive. Surveillance screening of patients known to have cirrhosis detected eight cases of early HCC. Seven of these had surgical resection and all are alive. CONCLUSIONS: New diagnoses of HCC have increased recently, irrespective of country of birth. In Australian-born patients alcoholic liver disease remains a major aetiological factor but the role of HCV requires further evaluation. Among immigrants, cirrhosis from chronic viral hepatitis accounts for most cases. We propose that prevention of cirrhosis caused by chronic viral hepatitis should have the greatest long-term impact on prevention of HCC in Australia. The role of surveillance of people with cirrhosis to detect small and potentially resectable tumours should be explored.

Adult↗

Non-iatrogenic trauma to the extrahepatic biliary tract.

Between 1980 and 1991, 15 cases of non-iatrogenic extrahepatic biliary tract trauma have been managed at Westmead and the Royal Canberra Hospitals. There were seven cases of gall-bladder injury and eight bile duct injuries. Four cases resulted from penetrating trauma whereas 11 resulted from blunt trauma. Associated injuries were common. Cholecystectomy was the preferred method of management for gall-bladder injuries whereas the bile duct injuries were managed by a variety of techniques. There were three deaths in the series, mostly related to associated injuries. Bile duct injuries were associated with longer hospitalization than gallbladder injuries.

Adolescent↗