Search PubMed⌕ Search

Biomedical subjects

M Evans

Publications and source records attributed to M Evans.

At least 361 records · Page 20Linked to original sources
PubMed1983

Administration of meptazinol to opiate-dependent patients.

A double blind comparison of the effect of intravenous meptazinol 100 mg and placebo was carried out on 8 opiate-dependent patients who were on a prolonged methadone withdrawal regime. Psychological and physiological measurements revealed no significant differences between meptazinol and placebo, and no patient reported pleasurable effects following meptazinol injection. These findings support the evidence from animal studies that meptazinol is unlikely to be abused by opiate addicts or to lead to dependence.

Adolescent↗
PubMed1982

Levamisole and postoperative complications: a controlled clinical trial.

We studied the relationship between cell-mediated immunity (assessed by preoperative skin reactions to four recall antigens) and postoperative infective complications in 166 patients undergoing major laparotomies. They were randomly allocated to receive 150 mg of levamisole or placebo on the day of operation and for the following 2 days; their course was followed for at least 1 month. Neither the degree of preoperative anergy nor the administration of levamisole resulted in any significant differences in numbers of postoperative deaths or infective complications, but the levamisole group had significantly less postoperative pyrexia than the control group.

Adolescent↗
PubMed1982

Staples or sutures for colonic anastomoses--a controlled clinical trial.

We randomly allocated 100 patients undergoing colonic or rectal resections to have their anastomoses made either by a single layer of braided polyester interrupted sutures, or by the SPTU circular stapling instrument. Twelve anastomoses leaked, 4 being detected only by contrast enema. There was no difference in leak rate between the two anastomotic methods, but patients in the stapled group had a significantly higher incidence of minor wound infection, and spent significantly more days in hospital after operation. The stapling instrument is no safer than sutures for colonic and rectal anastomoses, but considerably facilities the performance of a low anterior resection.

Adult↗
PubMed1982

Adjuvant oral razoxane (ICRF-159) in resectable colorectal cancer.

One hundred and seventy six patients (81 controls, 95 receiving treatment) have entered a prospective randomized trial of long-term oral adjuvant razoxane (ICRF-159) following removal of a colorectal cancer. The median follow-up is 34 months. The treated patients in Dukes' groups B and C have a significantly longer disease-free interval than the control patients (P = 0.01 'as randomized' and P = 0.004 'as treated'). The differences in survival for Dukes' groups B and C are not significant, although follow-up is short. In Dukes' groups B and C, however, 24 of 56 of the patients in the control group have died (43%), as against only 17 of 64 in the treatment group (27%). The treatment produces very few side-effects, is well tolerated by patients, and is taken orally.

Administration, Oral↗
PubMed1982

Induction of dark-adaptive retinomotor movement (cell elongation) in teleost retinal cones by cyclic adenosine 3','5-monophosphate.

In the teleost retina, the photoreceptors and retinal pigment epithelium (RPE) undergo extensive movements (called retinomotor movements) in response to changes in light conditions and to an endogenous circadian rhythm. Photoreceptor movements serve to reposition the light-receptive outer segments and are effected by changes in inner segment length. Melanin granule movements within the RPE cells provide a movable melanin screen for rod outer segments. In the dark (night), cones elongate, rods contract, and pigment granules aggregate to the base of the RPE cell; in the light (day), these movements are reversed. We report here that treatments that elevate cytoplasmic cyclic adenosine 3',5'-monophosphate (cAMP) provoke retinomotor movements characteristic of nighttime dark adaptation, even in bright light at midday. To illustrate this response, we present a quantitative description of the effects of cyclic nucleotides on cone length in the green sunfish, Lepomis cyanellus. Cone elongation is induced when light-adapted retinas are exposed to exogenous cAMP analogues accompanied by phosphodiesterase (PDE) inhibitors (either by intraocular injection or in retinal organ culture). Cone movements is not affected by cyclic GMP analogies. Dose-response studies indicate that the extent, but not the rate, of cone elongation is proportional to the concentration of exogenous cAMP and analogue presented. As has been reported for other species, we find that levels of cAMP are significantly higher in dark- than in light-adapted green sunfish retinas. On the basis of these observations, we suggest that cAMP plays a role in the light and circadian regulation of teleost cone length.

Animals↗
PubMed1982

Production of tolerance and physical dependence in the rat by simple administration of morphine in drinking water.

1 Rats are capable of consuming solutions of morphine sulphate in drinking water ad libitum in the absence of taste-masking chemicals and without the need for scheduled provision or prior parenteral administration of the drug. 2 The success of this method depends on the initial provision of a 0.1 mg/ml solution of morphine sulphate. 3 When the drug concentration is increased to 0.4 mg/ml, the rats achieve an average daily intake of 50 mg/kg body wt. each. 4 Daily intake of morphine may be increased by at least about three fold by increasing the drug concentration to 1.2 mg/ml. 5 Oral morphine administration causes only a moderate loss in body weight. 6 Rats whose daily intake of the drug is 50 mg/kg exhibit tolerance to the analgesic action of morphine and show a drastic loss in body weight at 24 h after withdrawal and most of the behavioural symptoms of the naloxone-precipitated withdrawal syndrome. 7 It is suggested that this simple method of morphine administration is suitable for further biochemical and behavioural studies of the actions of the drug.

Animals↗
PubMed1982

Inhibition of rat liver tryptophan pyrrolase activity and elevation of brain tryptophan concentration by acute administration of small doses of antidepressants.

1 Administration to rats of a 0.5 mg/kg dose of any of 19 antidepressants, but not that of many other drugs, causes a significant inhibition of the total enzyme and apoenzyme activities of liver tryptophan pyrrolase (of 24-48% and 37-65% respectively) and elevates brain tryptophan concentration by 13-66%. 2 When liver tryptophan pyrrolase activity is enhanced by pretreatment with cortisol or haematin, subsequent administration of a 0.5 mg/kg dose of some, but not other, antidepressants causes inhibition, which is weak (up to 38%). 3 This weak inhibition of the enhanced pyrrolase activity together with other pharmacological and physiological factors could explain the time lag between the start of antidepressant medication and the occurrence of a therapeutic response. 4 The cortisol-induced and haematin-activated pyrrolases respond differentially to inhibition by imipramine and amitriptyline, and this may explain the differential response to these two drugs of depressed patients in relation to urinary excretion of the noradrenaline metabolite 3-methoxy-4-hydroxyphenylglycol. 5 The results are discussed in relation to the mechanism of action of antidepressants and the possible involvement of disturbed hepatic tryptophan metabolism in depressive illness.

Animals↗
PubMed1982

Solvent misuse: educational implications.

1 This article confines itself to an investigation of the possible educational strategies which might be helpful in the prevention of solvent misuse. The empirical evidence for the effectiveness, or otherwise, of the drug education generally is examined and from this the appropriateness of various approaches is assessed. 2 A model unit of teaching material which can be used in a prevention of solvent misuse programme is offered. 3 A brief discussion of some of the ethical considerations related to education about solvent misuse is presented.

Health Education↗
PubMed1981

The role of liver tryptophan pyrrolase in the opposite effects of chronic administration and subsequent withdrawal of drugs of dependence on rat brain tryptophan metabolism.

1. Chronic administration of morphine, nicotine or phenobarbitone has previously been shown to inhibit rat liver tryptophan pyrrolase activity by increasing hepatic [NADPH], whereas subsequent withdrawal enhances pyrrolase activity by a hormonal-type mechanism. 2. It is now shown that this enhancement is associated with an increase in the concentration of serum corticosterone. 3. Chronic administration of the above drugs enhances, whereas subsequent withdrawal inhibits, brain 5-hydroxytryptamine synthesis. Under both conditions, tryptophan availability to the brain is altered in the appropriate direction. 4. The chronic drug-induced enhancement of brain tryptophan metabolism is reversed by phenazine methosulphate, whereas the withdrawal-induced inhibition is prevented by nicotinamide. 5. The chronic morphine-induced changes in liver [NADPH], pyrrolase activity, tryptophan availability to the brain and brain 5-hydroxytryptamine synthesis are all reversed by the opiate antagonist naloxone. 6. It is suggested that the opposite effects on brain tryptophan metabolism of chronic administration and subsequent withdrawal of the above drugs of dependence are mediated by the changes in liver tryptophan pyrrolase activity. 6. Similar conclusions based on similar findings have previously been made in relation to chronic administration and subsequent withdrawal of ethanol. These findings with all four drugs are briefly discussed in relation to previous work and the mechanism(s) of drug dependence.

Animals↗
PubMed1981

Compression suture of the abdominal wall: a controlled trial in 302 major laparotomies.

Monofilament nylon suture material undergoes both plastic and elastic elongation when stretched. Nylon inserted as a continuous suture for approximation of the abdominal musculo-aponeurosis may, therefore, allow early separation of the cut edges, which may predispose to the later development of an incisional hernia. This hypothesis was tested in a consecutive series of 302 major laparotomies randomized to be sutured with continuous mass nylon either to approximate or to compress the deep layers. The incidence of incisional hernia at 6 months in the group sutured with normal tension was 10.0 per cent, compared with 5.5 per cent in those tightly sutured. There was, however, an increased rate of minor wound infection in the latter group.

Abdominal Muscles↗