PubMed Health⌕ Search

Biomedical subjects

T Mackenzie

Publications and source records attributed to T Mackenzie.

At least 19 recordsLinked to original sources
PubMed2003

The effectiveness of scalp cooling in preventing alopecia for patients receiving epirubicin and docetaxel.

The aim of this study was to establish the effectiveness of scalp cooling in preventing alopecia for patients with breast cancer who received the trial combination chemotherapy of Epirubicin and Docetaxel. Doubt remains about the general effectiveness of scalp cooling in preventing hair loss for patients receiving chemotherapy. There is very little information available about its specific effectiveness with combinations of Taxanes and Anthracycline drugs. Of the 40 patients who received this drug combination, 10 were included in a pilot study whereas the remaining 30 constituted the main study sample. A randomized controlled study was undertaken whereby the intervention group received scalp cooling via gel cool caps and the control group received no specific preventative intervention. Nurses assessed participants' hair loss using a modified version of the WHO scale at seven time points and also recorded hair loss photographically. Two independent experts rated the photographs using the same scale. Patients self-reported in relation to overall hair loss, hair condition, levels of emotional upset, negativity about appearance, hair re-growth and wig use. Significantly greater hair loss was apparent in the control group during most of the treatment period. However, the level of protection afforded by the cool caps was relatively poor with this chemotherapy combination. The marginal benefits of scalp cooling in this context must be clearly explained to patients.

Alopecia↗
PubMed2001

Heterogeneity of type I diabetes: analysis of monozygotic twins in Great Britain and the United States.

AIMS: To determine the risk, hazard rate and factors affecting progression to diabetes in monozygotic twins of patients with Type I (insulin-dependent) diabetes mellitus. METHODS: Prospective analysis was done of two cohorts of non-diabetic monozygotic twins of patients with Type I diabetes from Great Britain (n = 134) and the United States (n = 53). RESULTS: The diabetes-free survival analysis was similar between both cohorts (p = 0.6). The combined survival analysis (n = 187, median follow-up = 17.7 years, range = 0.01-57) at 40 years of discordance estimated a 39% probability of diabetes for the initially discordant twin. Survival analysis with left truncation of data estimated that probability to be 50%. For twins who became concordant (n = 47), the median discordance time was 4.2 years (range 0.4 to 39), exceeding 15 years in 23.4%. Twins of probands diagnosed at 24 years of age or younger had a 38% probability of diabetes by 30 years of discordance, compared with 6% for twins of probands diagnosed after 24 years of age (p = 0.004). The twins of probands diagnosed before 15 years of age had the highest diabetes hazard rate in the first discordance year, decreasing thereafter. By survival analysis, diabetes risk was higher in twins who were heterozygous for DR3-DQ2 and DR4-DQ8 than in twins with neither DR3-DQ2 nor DR4-DQ8 (p < 0.05). CONCLUSION/INTERPRETATION: Monozygotic twins of patients with Type I diabetes from two different countries had similar rates of progression to diabetes. Whereas most twins did not develop diabetes, 25% of the twins who progressed did so after more than 14 years of discordance. An age-related heterogeneity was observed, with higher progression to diabetes for twins of patients diagnosed at a younger age.

Adolescent↗
PubMed2001

Risk factors for intermediate-term survival after coronary artery bypass grafting.

BACKGROUND: Risk factors for short-term mortality after coronary artery bypass grafting are well established, but little is known about risk factors for intermediate-term mortality. METHODS: We analyzed the outcomes of 11,815 patients undergoing coronary artery bypass grafting in one of the 43 cardiac surgery programs of the Department of Veteran Affairs. Risk factors for intermediate- and short-term mortality were determined using Cox proportional hazards regression models. Effects of risk factors during these two periods were explicitly compared. RESULTS: We found important differences in mortality risk-factor sets between the intermediate- and short-term periods after coronary artery bypass grafting. The majority of predictors of intermediate-term mortality were noncardiac-related variables, whereas the majority of predictors of short-term mortality were cardiac-related variables. Impaired functional status, chronic obstructive pulmonary disease, and renal dysfunction had greater effects in the intermediate-term period. Previous heart operation, angina class III or IV, previous myocardial infarction, and preoperative use of an intraaortic balloon pump had greater effects in the short-term period. CONCLUSIONS: The risk factors for intermediate-term mortality identified in this study can augment preoperative risk assessment and counseling of patients. Clinicians should be aware of the importance of noncardiac-related variables as predictors of mortality in the intermediate-term period after coronary artery bypass grafting.

Aged↗
PubMed2001

Health-related quality of life with coronary heart disease prevention and treatment.

Estimating the net benefits of dyslipidemia treatment is limited by the lack of comprehensive and standardized information on the preference for dyslipidemia and coronary heart disease. In a hospital-based study, we measured the health-related quality of life (HRQOL) of healthy participants without dyslipidemia (n = 307) and with dyslipidemia (n = 251) and patients with coronary heart disease (n = 320). Compared to the healthy participants without dyslipidemia, those with dyslipidemia reported lower adjusted mean scores on the Rating Scale (-2.8 points, P = 0.02) and the SF-36 General Health Scale (-3.3 points, P = 0.02). No differences were observed on the Time Trade-off and the Standard Gamble Scales. Coronary patients reported lower scores on all preference scales and most SF-36 scales. The causes of the small but real reduction in HRQOL reported by dyslipidemic individuals should be identified in order to optimize the net benefits of lipid therapy.

Adult↗
PubMed2001

Survival after first esophageal variceal hemorrhage in patients with biliary atresia.

OBJECTIVE: To determine the influence of the new onset of esophageal variceal hemorrhage (EVH) on transplant-free survival in children with biliary atresia and to examine variables that predicted survival after the onset of EVH. METHODS: Retrospective chart review of 134 patients with biliary atresia who underwent portoenterostomy between 1973 and 1992 at a single institution; 29% had EVH. RESULTS: The risk of death or need for liver transplantation was 50% at 6 years after the initial episode of EVH. Patients with a serum bilirubin concentration < or =4 mg/dL at the first episode of EVH had transplant-free survival of >80% for 4 years after this episode, those with bilirubin levels >4 to 10 mg/dL had 50% survival at 1 year, and those with bilirubin levels >10 mg/dL had 50% survival at 4 months. The risk of death or transplant for a child with EVH and total serum bilirubin levels >10 mg/dL was 12.0 (95% CI: 6.0, 24.1), 4 to 10 mg/dL was 7.2 (3.1, 16.7), and < or =4 mg/dL was 0.6 (0.1, 3.1) times the risk of a same-aged child who did not have EVH. CONCLUSIONS: Children with biliary atresia and first EVH episode have a variable prognosis related to total serum bilirubin concentration at the time of the episode.

Biliary Atresia↗
PubMed2000

Does midazolam alter the clinical effects of intravenous ketamine sedation in children? A double-blind, randomized, controlled, emergency department trial.

STUDY OBJECTIVE: This study was conducted to investigate the frequency and severity of adverse effects, specifically emergence phenomena, experienced by patients receiving intravenous ketamine with or without midazolam for sedation in a pediatric emergency department. METHODS: Patients aged 4.5 months to 16 years receiving ketamine sedation were prospectively enrolled in a double-blind, randomized, controlled study at a university-affiliated children's hospital-pediatric ED. All patients received ketamine (1 mg/kg) and glycopyrrolate (5 microgram/kg) intravenously. Patients were randomly assigned to receive midazolam (0.1 mg/kg) intravenously or no midazolam. Total time of sedation, sedation efficacy, and adverse effects were recorded. Adverse effects were compared between patients receiving ketamine versus those who received ketamine and midazolam. Additional comparisons were made based on age and number of ketamine doses administered. RESULTS: Two hundred sixty-six patients were studied; 129 received ketamine and 137 patients received ketamine and midazolam. Time of sedation and efficacy of sedation were equivalent between groups. Overall, adverse effects with ketamine sedation included respiratory events (12 [4.5%]), vomiting (50 [18.7%]), emergence phenomena in the pediatric ED (71 [26.7%]), and emergence phenomena at home (60 [22.4%]). Significant emergence phenomena in the pediatric ED (ie, nightmares, hallucinations, and severe agitation) occurred in 7.1% of the ketamine group and in 6.2% of the ketamine-midazolam group, a rate difference of 0.8 (95% confidence interval [CI] -5.3 to 7.0). The addition of midazolam led to an increased incidence of oxygen desaturation events (ketamine 1.6% versus ketamine-midazolam 7.3%; rate difference -5.7, 95% CI -10.6 to -0.9) but a decreased incidence of vomiting (ketamine 19.4%, ketamine-midazolam 9.6%, rate difference 9.8, 95% CI 1.4 to 18.2). The incidence of emergence phenomena and significant emergence phenomena was not affected by the addition of midazolam. However, the addition of midazolam was associated with more agitation in the pediatric ED in children 10 years or older (ketamine 5.7% versus ketamine-midazolam 35.7%; rate difference -30.0, 95% CI -10.7 to -49.3). Age breakdown further showed 6.3% (95% CI 0.9 to 11.6) more episodes of oxygen desaturation in the ketamine-midazolam group in children younger than 10 years, and 12.1% (95% CI 1.5 to 22.6) more vomiting episodes in the ketamine group in children younger than 10 years. CONCLUSION: Ketamine and combined ketamine and midazolam provided equally effective sedation. The addition of midazolam did not alter the incidence of emergence phenomena. Vomiting occurred more frequently in the ketamine only group, whereas oxygen desaturation occurred more frequently in the ketamine-midazolam group. These findings were more pronounced in patients younger than 10 years. Parental and physician satisfaction remained high for all patients receiving intravenous ketamine sedation.

Adolescent↗
PubMed1999

Comparing the psychometric properties of preference-based and nonpreference-based health-related quality of life in coronary heart disease. Canadian Collaborative Cardiac Assessment Group.

A cross-sectional survey (n = 878) was conducted to compare the psychometric properties of three preference-based and one nonpreference-based health-related quality of life measures among healthy subjects with and without treatment for dyslipidemia and/or hypertension and patients with coronary heart disease (CHD). All measures were stable over a 3 to 6 week period. Compared to the Time Trade-off (TTO) and the Standard Gamble (SG), the Rating Scale (RS) correlated with the SF-36 Health Survey most highly. In contrast to the SF-36 General Health Perception (GHP), the SF-36 Physical Component scale and the RS, the TTO and SG were less able to discriminate CHD patients with various levels of physical disability. Only the SF-36 GHP subscale and the RS were able to differentiate healthy participants from participants receiving dyslipidemia and/or hypertension treatment. Neither the SF-36 Physical or Mental Component scales were able to discriminate these two groups. Overall, these results suggest that unlike the RS, the TTO and the SG, as administered in this study, may not be sufficiently sensitive to measure the impact of primary cardiovascular disease prevention strategies on the health-related quality of life of the participants.

Adult↗
PubMed1999

Long-term efficacy of humalog in subjects with Type 1 diabetes mellitus.

AIMS: To evaluate the long-term effectiveness of Humalog insulin in lowering post meal glucose excursions. METHODS: Twenty young subjects with Type 1 diabetes mellitus (DM) who had received insulin-lispro (Humalog) for a least 1 year (mean +/- SD 1.8+/-1.6 years) were studied on two occasions, 3-14 days apart. They consumed a similar breakfast consisting of 450-600 kCal having fasted overnight. The same amount of human soluble Humulin Regular or Humalog insulin was given 10 min before the meal in a randomized, double-blind fashion. RESULTS: Postprandial glucose excursions at 30, 60, and 120 min were significantly lower (P<0.001, ANCOVA) when subjects received Humalog as compared to human soluble insulin. Serum-free insulin levels were significantly higher (P<0.001, ANOVA) at 30 and 60 min when subjects received Humalog as compared with human soluble insulin. Humalog antibody levels after up to 5.4 years of receiving Humalog insulin were not elevated beyond the values at 1 year. CONCLUSIONS: We conclude that Humalog insulin is effective in lowering postprandial glucose excursions even after up to 5.4 years of treatment.

Adult↗
PubMed1999

A Canadian survey of prophylactic antibiotic use among hip-fracture patients.

OBJECTIVE: To study how surgical prophylactic antibiotics (SPAs) were utilized in the perioperative management of surgery for hip fractures. DESIGN: Retrospective chart review of randomly selected medical records. SETTING: Twenty-two hospitals (teaching, nonteaching, community, and large urban referral centers) from across Canada. PATIENTS: Patients admitted in 1990 with a diagnosis of hip fracture. METHODS: Complete medical records of 438 patients were examined; 352 cases who underwent surgical repair of a fractured hip with insertion of prosthetic material were included in analysis. Perioperative SPA use was assessed by abstracting the agent(s) chosen, dosages, time given with respect to the incision, and duration of postoperative use. Fourteen patient and process-of-care variables related to SPA were examined. RESULTS: 247 (70%) of 352 cases did not receive a dose of SPA 2 hours preoperatively. Ten percent of preoperative SPA was administered either too early or during the procedure. In 91 (39%) of 231 cases receiving SPA, the first dose was not administered until the end of the procedure. Preoperative SPA consisted of a parenteral first-generation cephalosporin for 94% of cases. SPAs were continued more than 24 hours postoperatively in 78% of cases. Lack of a written order for SPA, being a nonteaching hospital, and shorter duration of surgical procedure were predictive of failure to receive SPA in an effective manner. CONCLUSIONS: Most hip-fracture-surgery patients did not receive effective antibiotic prophylaxis as required to prevent serious wound infections. This important variable can be included for surveillance, so that corrective measures can be taken to assure effective prophylactic antibiotic administration.

Antibiotic Prophylaxis↗
PubMed1996

Use of ECT after brain injury.

Electroconvulsive therapy (ECT) was administered to a man with a history of a gunshot wound to the head with persisting skull defect and intracranial metallic foreign bodies. It appears that ECT is a safe and effective treatment for depression in this setting. Electrode placement is selected to avoid the skull defect and anticonvulsant therapy may be continued if the patient was previously receiving it.

Adult↗
PubMed1995

Evaluating individual performance in higher education: a new challenge for nurse educators.

In response to the demands for more accountability and efficiency in higher education, of which nurse education is now a part, this paper explores the evaluation of individual performance. It considers the purposes of staff appraisal and draws upon a study of criteria for self-appraisal of teachers and upon experience gained in introducing teacher appraisal into schools. Different teaching environments are discussed and the additional demands upon academic staff in universities in terms of research are considered in the light of the recent Research Assessment Exercises. Particular consideration is given to the performance of nursing departments in the 1992 exercise and to the implications for staff appraisal. Successful procedures for evaluating individual performance in schools that might transfer to higher education are identified and strategies that might be adopted by nursing departments are suggested. This paper argues that evaluation of individual performance is a worthwhile departmental function which, when successful, may help to create an atmosphere more conductive to the eventual successful introduction of total quality management to the institution as a whole. It concludes that the extra substantial demands upon staff time and energy, at a time when nursing departments are trying to establish themselves in the higher education sector, might be alleviated if the groundwork already undertaken in schools is put to good use.

Education, Nursing, Baccalaureate↗
PubMed1992

Can experienced clinicians predict the outcome of lupus nephritis?

The ability of four experienced clinicians to predict short-term outcome (serum creatinine level at 1 year) and long-term outcome (renal insufficiency) was evaluated in 87 patients with lupus nephritis. The correlational agreement and the accuracy of their predictions were contrasted with the actual outcomes observed and with statistically generated prognostic regression models. In contrast to previously published data, all four clinicians predicted both short-term outcomes (P < 0.001) and long-term outcomes (P < 0.02) well. The clinicians' predictions approximated that of a statistically generated computer model for both agreement and accuracy for renal function at 1 year. The four clinicians identified nearly identical clinical variables as important in determining prognosis. Provision of biopsy data to the clinicians improved short-term and long-term prediction slightly. The value of the statistical models was 'validated' by demonstrating that three of the four clinical variables identified by the models, but not by the clinicians, could enhance clinical prediction (P < 0.05). In addition, the extent of tubulo-interstitial involvement on biopsy, a predictor that has recently received increased attention, could improve the long-term clinical predictions of all four clinicians (P < 0.05).

Adolescent↗
PubMed1989

Depression and posttraumatic stress disorder in Southeast Asian refugees.

The authors report on 404 Southeast Asian refugees seen at a community clinic. Approximately three-quarters of these patients met DSM-III criteria for major depressive episode, and 14% had posttraumatic stress disorder. Complaints of pain and sleep disturbances were the predominant presenting symptoms. Most of the men were married, but more than 40% of the women were widowed. Between 15% and 30% of the patients reported specific traumatic experiences either in their homeland or during their escape. Widowhood and such traumatic experiences were positively correlated with more symptoms of depression and anxiety.

Acculturation↗
PubMed1986

Effects of immune colostrum on the expression of a K88 plasmid encoded determinant: role of plasmid stability and influence of phenotypic expression of K88 fimbriae.

Passaging of the K88-positive Escherichia coli strain CN6913 through synthetic medium containing immune colostrum gave rise to large numbers of K88-negative CN6913 variants. These K88-negative variants had all lost a single large plasmid known to encode the K88 genetic determinant. Four other large plasmids harboured by this strain were unaffected. Viable K88-positive and K88-negative variants of CN6913 accumulated at a similar rate in synthetic medium and in medium containing non-immune colostrum. In the presence of immune colostrum, viable cells of the K88-negative variant accumulated faster and to a greater extent in cultures than the K88-positive variant if incubated at 37 degrees C, which favours the phenotypic expression of K88. However, when similar cultures were incubated at 18 degrees C, a temperature known to inhibit phenotypic expression of K88, the accumulation of viable cells of the two variants was strictly comparable in all media and no loss of plasmid or increase in K88-negative variants was observed. Cells containing a pBR322-based K88-encoding recombinant plasmid were also eliminated by immune colostrum whereas cells containing pBR322 were not. Plasmids encoding the K99 antigen were not readily eliminated from strains passaged through medium containing immune colostrum. K99-negative variants that were detected still harboured the K99-encoding plasmid.

Animals↗
PubMed1985

Evaluation of procholeragenoid against experimental colibacillosis in piglets of vaccinated dams.

A toxoid prepared from the toxin of Vibrio cholera was adjuvanted with aluminium hydroxide and used for immunisation of pregnant gilts. Litters of these and of non-vaccinates were experimentally challenged with Escherichia coli producing either heat labile and heat stable (LT and ST) enterotoxins or ST enterotoxin only. Both the challenge strains of E coli produced high rates of mortality (64 and 68 per cent) and morbidity (80 and 100 per cent) in litters of non-vaccinated dams. Statistically highly significant protection against the LT/ST enterotoxin producing strain of E coli was obtained accompanied by the absence of colonisation of the small intestine by the pathogen. No protection against the ST enterotoxin producing strain was found. It is suggested that this vaccine would not confer passive protection to piglets against K99 and 987-positive E coli which usually produce ST enterotoxin only.

Animals↗
PubMed1985

Hemoglobin A1 in renal transplant recipients.

Studies were undertaken to determine levels of hemoglobin A1 in renal and heart transplant recipients. Hemoglobin A1 was measured by separation from Hb A using an affinity-column chromatography system. Significantly elevated levels of Hb A1 were found in all renal transplant patients; diabetic transplant recipients had the highest levels. There was no correlation between serum creatinine and Hb A1 levels in these transplant recipients. The Hb A1 level did correlate with the prior level of glycemia in these patients. Our findings raised the specter of the consequences of disturbed carbohydrate metabolism in these patients as not being different than that observed with other forms of end-stage renal disease management. Finally, in both diabetic and nondiabetic renal transplant recipients, measurement of Hb A1 can serve as a useful adjunct to assess prior glycemia when such information is not available to the clinician.

Adult↗
PubMed1984

The importance of age on prostaglandin E2 excretion in normal and hypertensive men.

Previous studies have shown reduced levels and total urinary excretion of prostaglandin E2 in a heterogeneous population of patients with hypertension. The following study was undertaken to extend these observations to focus on the influence of age and blood pressure on renal prostaglandin E2 excretion in males. Four groups of human subjects were studied on an ad libitum diet of at least 2 g salt per day: group 1 consisted of normal young men; group 2 consisted of young men with essential hypertension; group 3 consisted of older nonhypertensive men; group 4 consisted of older hypertensive men. Reduced urinary prostaglandin E2 excretion was seen in the elderly hypertensive group but not the young hypertensives. Thus, when all hypertensives were compared to control the reduced prostaglandin E2 excretion was accounted for primarily by the elderly hypertensives. The reduction of prostaglandin E2 excretion could not be accounted for by normal ageing alone. Whether cause or effect, alterations of renal prostaglandin physiology accompanied hypertension in elderly men. No clear alteration of prostaglandin E2 physiology was noted in young male hypertensives.

Adult↗