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C MacLeod

Publications and source records attributed to C MacLeod.

At least 37 records · Page 2Linked to original sources
PubMed1997

High-dose-rate brachytherapy in the management of high-grade intraepithelial neoplasia of the vagina.

The majority of women with high-grade intraepithelial neoplasia (VAIN 3) are over 60 years of age and have a history of premalignant or malignant disease of the cervix. Although the natural history of VAIN is not well defined, high-grade lesions are premalignant. Ablative treatment with laser or 5-fluorouracil cream is commonly unsatisfactory. Several series have reported a low rate of recurrence and complications if VAIN 3 is treated with low-dose-rate brachytherapy. This retrospective review reports the outcome of 14 patients treated with high-dose-rate brachytherapy, with a dose of 34 to 45 Gy in 4.5- to 8.5-Gy fractions. Treatment was well tolerated with no severe early or late toxicity observed. At a median follow-up of 46 months 1 patient progressed to invasive carcinoma of the vagina; in another patient VAIN 3 persisted.

Adult↗
PubMed1997

Carcinoma of the esophagus treated with radical chemoradiation 19 years after irradiation for recurrent breast cancer.

Prior irradiation to a site is a relative and often absolute contraindication to further irradiation because the tolerance dose of normal tissues is usually exceeded and therefore the risk of serious long-term side-effects is high. This case report describes radical salvage chemoradiation for an esophageal carcinoma in a patient who had prior high-dose neck and chest wall irradiation for the management of a breast cancer 19 years previously.

Adenocarcinoma↗
PubMed1997

Influence of the angiotensin converting enzyme I/D gene polymorphisms on left ventricular diastolic filling in patients with essential hypertension.

BACKGROUND: An insertion/deletion (I/D) polymorphism in the angiotensin converting enzyme (ACE) gene accounts for 50% of the variance in serum ACE activity. ACE is responsible for the generation of angiotensin II, which not only has pressor and mitogenic activities but also exerts effects on left ventricular diastolic performance. OBJECTIVE: To investigate the contribution of genetic polymorphisms at the ACE gene to the development of diastolic functional abnormalities in 100 patients with essential hypertension. METHODS AND RESULTS: The left ventricular mass (LVMI) of each patient was assessed echocardiographically. We calculated peak and integral early:late left ventricular diastolic filling ratios (E:AP, and E:AI, respectively) and determined the ACE genotype from leukocyte DNA. There was no significant difference in age, sex, blood pressure and LVMI among genotype groups. Analysis of covariance modelled for indices of diastolic function, adjusted for age, sex, heart rate and LVMI, demonstrated that the E:AP interacted with age (P < 0.0001), heart rate (P < 0.001) and ACE genotype (P = 0.018). Similarly, the E:AI interacted with age (P < 0.001), heart rate (P = 0.025) and ACE genotype (P = 0.047). There was a strong correlation between the E:AP and the LVMI for the DD group (r = -0.81, P < 0.0001) but not for the ID (r = -0.03, P = 0.83) and II (r = -0.23, P = 0.23) groups. CONCLUSIONS: These findings suggest that that the I/D polymorphism of the ACE gene influences the relationship between left ventricular mass and echocardiographic left ventricular diastolic filling abnormalities in patients with essential hypertension.

Adult↗
PubMed1997

High-dose-rate brachytherapy in the management of carcinoma of the cervix: an 8-year Australian experience.

High-dose-rate brachytherapy was introduced at this hospital for the treatment of gynaecological malignancy in 1985. A retrospective analysis was performed of 103 patients with cervix cancer treated with this technique from 1985 to June, 1993. The patients were analyzed for treatment parameters, response, survival, relapse and toxicity. Five-year survival was 78% for Stage 1B, 72% for Stage 2A, 42% for Stage 2B and 29% for Stage 3B. The severe late toxicity rate was 4.9%. These results are similar to reported international series that have used either low-dose-rate or high-dose-rate brachytherapy.

Actuarial Analysis↗
PubMed1996

The emotional Stroop task and psychopathology.

Attentional bias is a central feature of many cognitive theories of psychopathology. One of the most frequent methods of investigating such bias has been an emotional analog of the Stroop task. In this task, participants name the colors in which words are printed, and the words vary in their relevance to each theme of psychopathology. The authors review research showing that patients are often slower to name the color of a word associated with concerns relevant to their clinical condition. They address the causes and mechanisms underlying the phenomenon, focusing on J.D. Cohen, K. Dunbar, and J.L. McClelland's (1990) parallel distributed processing model.

Anxiety Disorders↗
PubMed1995

Implicit and explicit memory bias in anxiety: a conceptual replication.

Williams, Watts, MacLeod and Mathews' (1988) [Cognitive psychology and the emotional disorders. Chichester, Wiley] model of anxiety and cognition leads to the prediction that anxious subjects will show an implicit, but not an explicit, memory advantage for threat-related information. Mathews, Mogg, May and Eysenck (1989) [Journal of Abnormal Psychology, 98, 401-407] obtained marginally significant support for this prediction in an experiment that tested memory using word stem completion tasks following a self-referent encoding procedure. However, neither the reliability nor generality of these findings have been established. The current experiment was designed to provide a conceptual replication of Mathews et al.'s study, using different tests of implicit memory (i.e. tachistoscopic identification) and explicit memory (i.e. recognition) and an alternative type of encoding task (i.e. colour naming stimulus words). 16 generalised anxiety disorder patients, and 16 non-anxious control subjects were tested. As predicted, the anxiety patients showed a relative implicit memory advantage for threat-related stimulus words, while the two subject groups did not differ in their pattern of explicit memory performance. These results support the predictions generated by Williams et al.'s model of anxiety and cognition.

Adult↗
PubMed1995

Representational consequences of two modes of learning.

Two experiments tested the hypothesis that a non-strategic mode of rule learning results in atomic representations. In each case subjects were taught concepts under two different conditions, designed to favour either non-strategic or strategic learning. Following training, subjects demonstrated an equivalent ability to discriminate exemplars from non-exemplars of the concepts acquired under each of these two learning conditions. However, performance on a decompositional inference task, which required access to critical constituent elements within the rule representations, was disproportionately poor for a concept acquired under the training condition that favoured non-strategic learning. These findings lend support to the view that rule acquisition can be mediated by either of two modes of learning, and that the format of knowledge representations is not equivalent across these two learning modes.

Adult↗
PubMed1995

QT dispersion in essential hypertension.

Increased QT dispersion is associated with sudden cardiac death in congestive heart failure, hypertrophic cardiomyopathy, and following acute myocardial infarction. Patients with hypertension, in particular those with left ventricular hypertrophy, are also at greater risk of sudden cardiac death. We examined whether QT dispersion, which is easily obtained from a routine ECG, correlates with echo LVH. Sixty-nine untreated patients with essential hypertension had QT dispersion measured from a surface 12-lead electrocardiogram, and two-dimensional echocardiography performed to measure interventricular septal thickness, posterior wall thickness, and left ventricular internal diameter. Office blood pressure was recorded, and in 56 patients, 24 h ambulatory blood pressure monitoring was also done. Multivariate analysis demonstrated significant relationships between QT dispersion and office systolic blood pressure, and left ventricular mass index. Similar findings were obtained when QT dispersion was corrected for heart rate (QTc dispersion). After patients with electrocardiographic left ventricular hypertrophy (n = 5) were excluded from the analysis, the above relationships persisted. Increased QT dispersion is thus found in those essential hypertensives at greatest risk of sudden death. Since this relationship persists even in the absence of electrocardiographic left ventricular hypertrophy, measurement of QT dispersion might be a simple, non-invasive screening procedure to identify those hypertensives at greatest risk of sudden death.

Adolescent↗
PubMed1994

Effects of angiotensin II and aldosterone on diastolic function in vivo in normal man.

1. Doppler echocardiographic indices of diastolic function and systemic haemodynamics were studied in response to infusions of angiotensin II (1, 2, 5 and 10 ng min-1 kg-1), D-aldosterone (2, 4, 10 and 20 ng min-1 kg-1) and placebo [0.9% (w/v) NaCl] in ten normal male subjects. 2. Dose-related increases in systolic and diastolic blood pressure were observed with angiotensin II infusion at rates of 2 ng min-1 kg-1 and above, whereas no changes in blood pressure occurred with D-aldosterone. No changes in aortic stroke distance or heart rate were seen with either angiotensin II or aldosterone infusion. 3. Compared with placebo, angiotensin II infusion produced a dose-related prolongation of the isovolumic relaxation time [mean and 95% confidence intervals 12.0 (8.2-15.8) ms, P < 0.001] at 10 ng min-1 kg-1, and a significant reduction in the ratio between early and late transmitral flow velocity integrals at 2 ng min-1 kg-1, [-0.84 (-1.63 to -0.05), P < 0.05] and 5 ng min-1 kg-1 [-0.76 (-1.47 to -0.05), P < 0.05]. No changes in Doppler echocardiographic indices of diastolic function were observed with D-aldosterone infusion. 4. These data suggest that angiotensin II, even at a sub-pressor concentration, produces an impairment of left ventricular diastolic filling, which occurs independently of its effect on aldosterone release.

Adult↗
PubMed1994

Trends in bacterial infections in febrile neutropenic patients: 1986-1992.

BACKGROUND: Bacterial infection is a major cause of morbidity and mortality in neutropenic patients. AIMS: (1) To review patterns and trends in bacterial infections in three cohorts of febrile neutropenic patients managed by a single unit over a seven year period. (2) To relate any changes to the use of central venous (Hickman's) catheters and high-dose cytosine arabinoside chemotherapy. METHODS: Retrospective review of the results of initial bacteriological work-up performed on 344 episodes of febrile neutropenia. The three cohorts were 1986-87 (n = 102), 1989-90 (n = 92) and 1991-92 (n = 150). RESULTS: (1) The ratio of gram-negative to gram-positive bacteraemias fell from 1.36 in the first cohort to 1.05 in the second and 0.40 in the third (p = 0.03). There was a fall in both percentage and number of gram-negative isolates coupled with a rise in the frequency of gram-positive isolates. (2) Coincidentally there was a rise in the frequency of positive cultures from Hickman catheter entry wounds and an increasing frequency of simultaneous isolation of the same organism from the catheter entry site and the blood. The types of organisms isolated from catheter entry wounds showed a trend towards fewer gram-negative and more gram-positive. (3) A relationship was observed between the use of high-dose cytosine arabinoside chemotherapy and the incidence of bacteraemia (p = 0.025) but not with the change in types of organisms. CONCLUSIONS: Over seven years we have documented a major change in the types of infections, particularly bacteraemias, seen in febrile neutropenic patients. In our institution the more widespread use of intravenous catheters and high-dose cytosine arabinoside chemotherapy have been identified as two possible contributing factors.

Bacteremia↗
PubMed1994

A randomised dosage study of ceftazidime with single daily tobramycin for the empirical management of febrile neutropenia in patients with hematological diseases.

A single-institution, randomised trial was conducted to compare the clinical and microbiological efficacy of two different doses of ceftazidime in combination with a single daily dose of tobramycin for the empirical management of febrile neutropenic patients with hematologic disorders (absolute neutrophil count < 1 x 10(9)/l). Upon the development of fever or signs of sepsis, patients received either 2 g ceftazidime every 8 h plus a single daily dose tobramycin (5 mg/kg/day) (C2T, n = 73) or 1 g ceftazidime every 8 h plus a single daily dose of tobramycin (C1T, n = 77). In addition, flucloxacillin (1-2 g every 4 h) could be added if there was clinical suspicion of staphylococcal infection. Analysis was performed for the whole group and for the subset which did not receive flucloxacillin. When evaluated at 96 h, 70% (95% CI, +/- 11%) of patients randomised to C2T and 60% (95% CI, +/- 11%) randomised to C1T had responded (chi 2 = 1.27, P = 0.26). The response rates at 96 h for those who did not receive flucloxacillin were 77% (+/- 12%) and 74% (+/- 13%), respectively (chi 2 = 0.01, P = 0.92). Overall, 68 (93% +/- 6%) and 72 (94% +/- 6%) patients, respectively, eventually became afebrile (chi 2 = 0.06, P = 0.81). Renal function, as judged by serum creatinine, was unaffected by either antibiotic schedule. Within 10 days of antibiotic commencement there was one death in each arm and overall there were five deaths in each arm.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

Anxiety and the interpretation of ambiguity: a text comprehension study.

Beck's influential cognitive account of anxiety has led to the prediction that individuals vulnerable to anxiety should favor threatening interpretations of ambiguity (e.g., Beck & Clark, 1988; Beck, Emery, & Greenberg, 1986). The current study introduces a novel adaptation of the RSVP technique, previously used in text comprehension research, to evaluate this hypothesis. Results suggest that a group of 24 high trait anxious students did indeed selectively impose threatening interpretations on unconstrained ambiguous sentences. In contrast, a matched group of 24 low trait anxious students appeared to selectively impose non-threatening interpretations on such ambiguous sentences. These findings are fully consistent with the predicted anxiety-linked interpretative bias. Specific testable hypotheses are developed concerning the types of interpretative idiosyncrasies that plausibly may contribute to pathological anxiety.

Adolescent↗
PubMed1993

Single daily ceftriaxone and tobramycin in the empirical management of febrile neutropenic patients: a randomised trial.

A single-institution, randomised pilot trial was conducted to compare the clinical efficacy, microbiological efficacy and possible toxicity of empirical single daily antibiotic administration in febrile neutropenic patients with haematologic disorders (absolute neutrophil count < 1 x 10(9)/l). Upon the development of signs of sepsis, patients received either single daily dose tobramycin (5 mg/kg per day) plus ceftriaxone (2 g/day) (C + T, n = 47) or tobramycin (1.5 mg/kg, every 8 h) plus azlocillin (4 g, every 6 h) (A + T, n = 45). In addition, flucloxacillin (1-2 g, every 4 h) could be added if there was clinical suspicion of staphylococcal infection (17 in each arm). Analysis was performed for the whole group and for the subset which did not receive flucloxacillin. When evaluated at 96 h, 62% of patients randomised to C + T and 67% randomised to A + T had responded (95% confidence interval (CI) for the difference in rates, -25% to +15%). Ninety-six hour response rates for those who did not receive flucloxacillin were 73% and 78%, respectively (95% CI, -17% to +27%). Overall, 42 (89%) and 41 (91%) patients, respectively, eventually became afebrile (95% CI, -14 to 10%) and there was no evidence of altered renal function or electrolyte imbalance in patients randomised to single daily antibiotic therapy compared with the conventional (multi-daily dose) arm. Within 10 days of antibiotic commencement there was 1 death in the C + T arm and 4 deaths in the A + T arm, although overall there were 4 deaths in each arm. Our results suggest that single daily empirical antibiotic therapy with tobramycin and ceftriaxone is efficacious and is not associated with an increased incidence of renal dysfunction or electrolyte imbalance compared with conventional administration schedules of azlocillin plus tobramycin. Single daily therapy has the potential to lead to savings in nursing-staff time and materials and may well contribute to an improved quality of life for febrile neutropenic patients.

Adolescent↗
PubMed1992

Antibiotic-associated colitis and cystic fibrosis.

The use of antibiotics in patients with cystic fibrosis is widespread, and fecal carriage of Clostridium difficile occurs in up to 50% of these patients; however, antibiotic-associated colitis appears to be a rare occurrence. The reasons why this is so remain unknown. A case of antibiotic-associated colitis occurring in a patient with cystic fibrosis is described. Possible mechanisms for the rarity of antibiotic-associated colitis are reviewed and implications for prompt diagnosis and therapy are discussed.

Adult↗