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Biomedical subjects

J Webster

Publications and source records attributed to J Webster.

At least 235 records · Page 13Linked to original sources
PubMed1986

Enalapril in moderate to severe hypertension: a comparison with atenolol.

Patients with moderate to severe essential hypertension (mean untreated supine blood pressure 190/112 mm Hg) received once daily enalapril 20-40 mg or atenolol 50-100 mg, supplemented if required by hydrochlorothiazide 25-100 mg, in a randomized observer-blind trial. Both regimens produced a highly significant reduction in supine and standing blood pressure. There was no significant difference in the antihypertensive effects of enalapril and atenolol when they were used as monotherapy. After hydrochlorothiazide was added to patients not achieving 'target' blood pressure, the fall in systolic pressure was significantly greater in the enalapril group than in the atenolol group, despite similar dosage of hydrochlorothiazide in the two groups. At the end of 6 months' treatment, a supine diastolic blood pressure of 90 mm Hg or below was achieved in 74% of patients on enalapril plus hydrochlorothiazide and 56% of patients on atenolol plus hydrochlorothiazide. This difference was not statistically significant. A small rise in plasma urea and creatinine was observed in the enalapril group and a small rise of urea only in the atenolol group. These changes were statistically significant but of uncertain clinical importance. This study confirms that once daily enalapril and atenolol, both alone and in combination with hydrochlorothiazide, are effective drugs in the management of moderate to severe hypertension.

Adolescent↗
PubMed1986

Intravenous adenosine in the treatment of supraventricular tachycardia: a dose-ranging study and interaction with dipyridamole.

Increasing doses of adenosine were given by rapid intravenous bolus to seven patients with spontaneous supraventricular tachycardia. Adenosine restored sinus rhythm in 10 of 14 episodes of narrow complex tachycardia. In those patients in whom adenosine produced only transient ventricular slowing the underlying rhythm was atrial flutter. Transient dyspnoea occurred in all patients. In two patients taking dipyridamole the mean dose of adenosine which produced an electrophysiologic effect (restoration of sinus rhythm or ventricular slowing to under 100 beats min-1) was 1.0 +/- 0.52 mg, whereas in other patients the mean dose was 8.8 +/- 2.6 mg, suggesting potentiation of the action of adenosine by dipyridamole.

Adenosine↗
PubMed1986

General practitioners' attitudes towards the limited list.

From a one in 10 randomly selected sample of Scottish general practitioners 260 (85%) responded to a series of attitude statements concerned with limitation of NHS prescribing which was introduced in April 1985. Although a majority of respondents were against the current limited list scheme, two-fifths were in favour of it and many of the objectors were in favour of the principle of limitation but not the way in which it had been implemented.

Attitude of Health Personnel↗
PubMed1985

Computer assisted shared care in hypertension.

A computer assisted shared care scheme for the long term management and follow up of hypertensive patients has been developed in the Grampian Region. The scheme aims at facilitating the exchange of clinically important information between doctors and at achieving target levels of blood pressure with treatment in patients at highest risk of cardiovascular events. The shared care scheme has been well received by the local practitioners. Two hundred and fifty seven patients (18%) of 1426 patients under current long term follow up are assigned to follow up in the hospital aspect of the scheme. At the most recent visit 32% of patients in the hospital aspect and 10% of 1169 patients in the general practice aspect had blood pressure recordings above the target levels of 160/95 mm Hg. The stratification of patients formerly attending hospital clinics into grades of risk has rationalised our follow up procedures to allow the specialist resources to be freed and concentrated on those patients at highest risk and with the most complex problems. This computer assisted patient records system could be applied to other groups of high risk patients in whom long term follow up and surveillance are necessary--for example, patients with diabetes mellitus--and has implications for optimising and monitoring the delivery and outcome of care without overwhelming limited hospital resources.

Computers↗
PubMed1985

Are pre-obese people energy thrifty?

Metabolic rate and fat-free mass tend to be higher in obese people than in lean people. It has been suggested that pre-obese people have a low metabolic rate and only acquire their high metabolic rate from the storage of lean tissue which they gain while becoming obese. To test this hypothesis resting metabolic rate was related to percentage fat, with fat-free mass held constant, in 104 women with body fat ranging from 6% to 60% of body-weight. Results showed that the greater the percentage fat, the greater the metabolic rate. It is difficult to believe that fat people with a high metabolic rate relative to fat-free mass once had a low metabolic rate.

Adipose Tissue↗
PubMed1985

Ro 31-1118, a new cardioselective beta-adrenoceptor antagonist. Pharmacokinetics and effects on heart rate and blood pressure in mild hypertensives.

Five patients with mild hypertension were given single oral doses of Ro 31-1118 (10,20,40, and 80 mg) and placebo in a randomized, double-blind, within-patient study. Plasma concentrations of Ro 31-1118 and supine, standing, exercise, and post-exercise heart rates and blood pressures were measured before and at regular intervals after drug administration. The pharmacokinetic data were consistent with a one-compartment model with first-order absorption and a variable time lag. Peak plasma concentrations and area under curve were linearly related to dose, whereas time to peak concentration, half-time, clearance and apparent volume of distribution were dose-independent. There was a reduction in exercise and post-exercise heart rate of approximately 10% after 10 mg and 20 mg Ro 31-1118, and of approximately 15% after 40 mg and 80 mg. At all doses standing systolic blood pressure was reduced by approximately 5%. A similar fall was seen in exercise and post-exercise systolic blood pressures. There was no substantial effect of Ro 31-1118 on supine or standing heart rates nor on diastolic blood pressure. No adverse effects were reported. It is concluded that Ro 31-1118 has linear pharmacokinetics over the dose range 10-80 mg, and has a weak antihypertensive effect when administered in single doses to patients with mild hypertension.

Absorption↗
PubMed1985

Implantation, abortion, and birth after in vitro fertilization using the natural menstrual cycle or follicular stimulation with clomiphene citrate and human menopausal gonadotropin.

The incidence of pregnancy and abortion was analyzed in 1679 patients having embryos replaced after oocyte recovery and in vitro fertilization in order to alleviate their infertility. In these patients, 364 pregnancies were achieved and 108 abortions occurred. Patients were treated either on their natural cycle, having a spontaneous luteinizing hormone (LH) surge to induce ovulation, or after ovarian stimulation using clomiphene citrate alone or in combination with human menopausal gonadotropin (hMG). The data were assessed in relation to the numbers of embryos replaced, the follicular stimulation and ovulation induction regime used, the dose of gonadotropins and the dose of antiestrogens, and the age of the patient. The most successful treatment for the number of live births per laparoscopy was the use of clomiphene citrate in combination with human menopausal gonadotropin followed by human chorionic gonadotropin (hCG) to induce follicular maturation and ovulation. This treatment produced a significantly higher (P less than 0.001) number of patients with multiple embryos (86.5%). There was no significant effect on pregnancy or abortion with a low (less than 400-mg) or high (greater than or equal to 400-mg) dose of clomiphene. The total dose of gonadotropins used did not influence the incidence of pregnancy or abortion. The use of hCG with hMG induced a significant (P less than 0.01) positive effect on the incidence of pregnancy. The incidence of pregnancy showed a progressive decline with increasing age but there was a highly significant (P less than 0.01) increase in the incidence of abortion with increasing age. With increasing numbers of embryos replaced, up to three, the incidence of deliveries increased.(ABSTRACT TRUNCATED AT 250 WORDS)

Abortion, Spontaneous↗
PubMed1985

In vitro fertilization: a treatment for male infertility.

Three-quarters of 41 women whose husbands were the cause of infertility in the couple had one or more embryos replaced after in vitro fertilization. One-third became pregnant despite their long history of infertility; the incidence of pregnancy was 45% after one or more replacements of embryos. In a group of 61 couples where both partners were infertile, 26% became pregnant. These data indicate that the lower chance of fertilization with poor semen is balanced by a higher chance of pregnancy in women with a normally functioning reproductive system. Oligospermia, asthenospermia, teratospermia, and autoimmunity are among the many forms of male infertility which can now be successfully treated by in vitro fertilization. Overall, 57% of the oocytes were fertilized, and almost 50% of men with very low numbers of active spermatozoa (less than or equal to 0.5 X 10(6)/ml motile spermatozoa) were successful in establishing pregnancy. Two semen parameters impaired fertilization most: seminal inflammatory cells and low progressive activity. The collection of split ejaculates and the careful preparation of spermatozoa, by sedimentation and layering methods, proved to be beneficial, improving sperm motility and raising the chance of fertilization.

Embryo Transfer↗
PubMed1985

In vitro fertilization using cryopreserved donor semen in cases where both partners are infertile.

The incidence of pregnancy after in vitro fertilization (IVF) was studied in a group of 38 couples (55 cycles) where both partners were infertile. Cryopreserved donor semen (IVF-D) was used in all cycles. Results were compared with those in a control group of couples where the husband's semen was considered normal and only the wife was infertile. No significant differences were found between the IVF-D and control groups in the incidence of fertilization (80% versus 72%), pregnancy per cycle (33% versus 29%), and abortion (18% versus 20%), despite the considerably lower percentage of motile spermatozoa in the IVF-D group. Forty percent of patients, each treated unsuccessfully with at least 12 artificial inseminations with donor semen, became pregnant after one or two IVF-D cycles. It is concluded that IVF with frozen donor semen is a beneficial treatment for couples where both partners are infertile.

Female↗
PubMed1985

A comparison of single doses of bucindolol and oxprenolol in hypertensive patients.

Single doses of bucindolol 50, 100 and 200 mg were compared to placebo and single doses of oxprenolol 40, 80 and 160 mg in seven patients with mild hypertension, in a double-blind randomized study. Both bucindolol and oxprenolol inhibited exercise induced tachycardia. The mean maximum inhibition of exercise heart rate was similar after each dose of both drugs (20%, P less than 0.001). Bucindolol produced a significantly greater reduction in blood pressure than either oxprenolol or placebo. This was most apparent in standing systolic and diastolic and post-exercise systolic blood pressures between 1 and 2 h after dosing and was dose-related. All seven patients experienced adverse effects related to hypotension within the first 2 h after ingestion of bucindolol 200 mg. Plasma concentrations of oxprenolol, bucindolol or 5-hydroxy-bucindolol, sampled 2 h after dosing, could not be related to either the changes in blood pressure or to the occurrence of symptoms. The results emphasise the need for careful dose-finding of new drugs prior to their more widespread evaluation in phase 3 studies.

Adrenergic beta-Antagonists↗
PubMed1985

Interactions of NSAIDs with diuretics and beta-blockers mechanisms and clinical implications.

Indomethacin attenuates the antihypertensive effect of both thiazide diuretics and beta-adrenoceptor blocking drugs. The mechanisms of these interactions are poorly understood but sodium and water retention, suppression of plasma renin activity, alterations in adrenoceptor sensitivity and impaired synthesis of vasodilator prostaglandins may all contribute to this effect. Other non-steroidal anti-inflammatory drugs (NSAIDs) may share this property of indomethacin but sulindac, which is a selective inhibitor of extrarenal prostaglandin synthesis, appears not to. This may have important clinical and theoretical implications. Clinicians must beware of this potential interaction in any patient receiving treatment for hypertension. NSAIDs may also inhibit the natriuretic response to diuretics with resultant adverse effects in patients with heart failure and other forms of oedema. NSAIDs may also have adverse nephrotoxic effects which may be exacerbated by diuretic therapy.

Adrenergic beta-Antagonists↗
PubMed1985

A method of assessment during vocational training: report of a pilot study.

Problems arising from the present rate of failure of vocational trainees in the MRCGP examination are outlined; and the role of formative assessment during training in reducing this rate is considered. A study is described in which trainees in a number of centres were assessed by a method designed to measure specified cognitive abilities and areas of knowledge. The method, based on written papers, provides each candidate with a profile of performance and generates comparative standards. Reliability of marking, the distribution of candidate-scores within and between areas of assessment and techniques for monitoring the effectiveness of questions are reported. Use of the method by College as an educational service to trainees is considered, along with its potential as a Part I MRCGP examination.

Education, Medical, Graduate↗