Search PubMed⌕ Search

Biomedical subjects

K D MacRae

Publications and source records attributed to K D MacRae.

At least 55 records · Page 3Linked to original sources

Pragmatic versus explanatory trials.

This article considers the distinction between "explanatory" and "pragmatic" aims in clinical trials--the distinction between testing a biological hypothesis and providing evidence to permit a choice between alternative treatment policies. The choice of treatments to compare, the selection of patients for the trial, the study size, and how the treatment comparison should be made are among the matters discussed. In general, where explanatory and pragmatic aims conflict, the pragmatic aim will often take priority.

Bias↗

Human immunodeficiency virus infection, hepatitis B virus infection, and sexual behaviour of women attending a genitourinary medicine clinic.

During the six months immediately after a public information campaign about the acquired immune deficiency syndrome 1115 women who attended a genitourinary medicine clinic in west London were tested for antibodies to the human immunodeficiency virus (HIV). Three women (0.27%) were positive, and all three were regular sexual partners of men with high risk lifestyles--two intravenous drug users and one bisexual. A consecutive series of 647 women from the cohort was tested for antibodies for hepatitis B core antigen: 27 were positive, of whom six had been born in the United Kingdom and were not known to have been at risk. The two women who were seropositive for HIV who completed a questionnaire on their sexual behaviour before they were tested reported both anal and oral receipt of semen and were in the upper fifth percentile for lifetime sexual partners. More than half (53%) of 424 women who reported that they had non-regular sexual partners never used a condom. It is concluded that heterosexual women in London are at a low risk of becoming infected with HIV.

Acquired Immunodeficiency Syndrome↗

Randomised trial of endoscopic versus percutaneous stent insertion in malignant obstructive jaundice.

Patients with biliary obstruction due to malignant disease, and judged unfit for open operation, were randomised to have a biliary stent inserted either endoscopically via the papilla of Vater or percutaneously. Analysis after 75 patients had been entered showed that the endoscopic method had a significantly higher success rate for relief of jaundice (81% versus 61%, p = 0.017) and a significantly lower 30-day mortality (15% versus 33%, p = 0.016). The higher mortality after percutaneous stents was due to complications associated with liver puncture (haemorrhage and bile leaks). When stenting is indicated in elderly and frail patients the endoscopic method should be tried first.

Aged↗

Controlled acute trial of a thyrotrophin releasing hormone analogue (RX77368) in motor neuron disease.

Twenty five patients with motor neuron disease completed a double blind randomised cross over trial of RX77368, a stabilised TRH analogue, iv over 2 hours against saline. Temporary improvement in bulbar symptoms including speech, respiratory parameters, tongue movements and swallowing were seen. Fasciculations increased and spasticity decreased. Change in muscle force with drug was different from placebo but both increase and decrease in force were seen and did not result in detectable changes in function. Side effects were clinically significant in 50% of the patients and cleared within 12 hours. Prolonged rise of thyroxine and an increase in plasma levels of prolactin, thyroid stimulating hormone and growth hormone were seen and followed characteristic patterns.

Adult↗

The promising role of safe initial non-cisplatin-containing combination chemotherapy in nasopharyngeal tumors.

Twenty patients with previously untreated nasopharyngeal tumors received, as initial treatment, two courses of Schedule A chemotherapy including vincristine, 5-fluorouracil, bleomycin, hydrocortisone, methotrexate, and a folinic acid rescue, prior to definitive radiotherapy. Thirteen patients had Stage IV and seven had Stage III tumors, with nodal involvement in 18 patients (90%). Response to two courses of Schedule A chemotherapy was assessed on day 28, and overall, 18 patients responded. Side effects were minimal. Following radiotherapy 17 patients achieved a clinical complete remission. Durations of response ranged from 6 to 95+ months (median 40 months) and of survival from 8 to 95+ months (median 53 months). This chemotherapy protocol should be more widely evaluated as initial treatment in nasopharyngeal carcinomas since the 90% chemotherapy response rate and, after radiotherapy, 85% clinical complete remission rate was accomplished with minimal toxicity and interference with patients' quality of life and resulted in median overall survival figures of approximately four years.

Adult↗

Adjuvant chemotherapy in the treatment of breast cancer: results of a multicentre study.

248 patients with locally radically treated early breast cancer (196 node-positive) were randomized post-operatively between 6 courses of a 'CMF like' chemotherapy and no further treatment. Results (with a minimum of 5 years follow-up on every patient) favour chemotherapy with a significant increase in the median time to recurrence from 31 to 50 months for all patients (P = 0.04) and from 26 to 49 months for node-positive patients (P = 0.023). No significant effect on survival is seen although there is a trend towards longer survival in the treated group. The regimen used was relatively non-toxic when compared to the traditional CMF with 34% of patients experiencing mild nausea and vomiting immediately post-injection and only 11% complaining of more severe nausea and vomiting. Because of this lower toxicity the treatment was found to be amenable to administration in both regional hospitals and specialized centres.

Adult↗

Is bladder catheterization really necessary before laparoscopy?

A randomized prospective controlled trial compared a policy of bladder catheterization with no catheterization in patients undergoing laparoscopy. Of the 41 patients randomized to receive no catheterization, seven were actually catheterized on the judgement of the surgeon, but only one of them had greater than 50 ml of urine. Midstream urine obtained 6 days after laparoscopy was infected in 9 (21%) of the 42 patients allocated to receive catheterization and in only five (12%) of those allocated to the no-catheter group. Four of these five were actually not catheterized, giving an infection rate of 12% in the 34 patients not catheterized. The differences are statistically significant. A routine policy of catheterization for patients undergoing laparoscopy is questionable. All patients who are catheterized should be investigated for urinary tract infections after operation.

Adult↗

Effects of moderate alcohol consumption and smoking on fetal outcome.

Previous studies of the effects of moderate drinking on the outcome of pregnancy are assessed. The results of a prospective study of the association between alcohol consumption in pregnancy and birthweight, length of baby, head circumference and premature delivery are described. Consumption of more than 10 g alcohol per day in very early pregnancy or even before conception approximately doubled the risk that the infant would have a low birthweight. Cigarette smoking was also a risk factor for low birthweight. It may therefore be beneficial for women to reduce their alcohol consumption to one drink a day or less from before conception and give up smoking as well.

Abnormalities, Drug-Induced↗

Comparison of mucus substances in gastric juice of normal subjects, duodenal ulcer and dyspeptic patients.

The sugar and nitrogen content of the gastric juice was assessed in 27 patients with duodenal ulceration, 17 patients with dyspepsia, and 27 normal volunteers. Comparing the data for each constituent for each patient using a discriminant function analysis, it was shown that the normal group differed significantly from both the duodenal ulcer group and the dyspeptic group, but that there was only a degree of variation between the two groups of patients.

Adolescent↗

Head circumference as an index of fetal age.

By means of a light pen coupled with a microprocessor, the fetal head circumference of 594 fetuses was measured and the results compared with the biparietal diameter and abdominal circumference. In a statistically significant proportion of cases, the head circumference was more closely related than the biparietal diameter to both the abdominal circumference and the gestational age of the fetus as calculated from the mother's menstrual history. Possible reasons for this finding are discussed. It is concluded that the head circumference is a more accurate index of the age of the fetus and its growth potential than is the biparietal diameter, and that use of the head circumference should, in consequence, replace that of the biparietal diameter in obstetric scanning.

Abdomen↗