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Biomedical subjects

J Collier

Publications and source records attributed to J Collier.

At least 109 records · Page 6Linked to original sources
PubMed1990

Promotion by the British pharmaceutical industry, 1983-8: a critical analysis of self regulation.

Since 1958 the Association of the British Pharmaceutical Industry (ABPI) has attempted to regulate the promotion of prescription medicines through its code of practice. This regulation is described and analysed for the six years 1983-8 using the reports on 302 complaints considered by its code of practice committee and annual reports. The complaints came mainly from doctors (143, 48%) and competing companies (103, 33%). The committee found a total of 379 breaches of the code in 192 (63%) of the complaints. Additional breaches were detected by informational scrutiny of advertisements by the ABPI secretariat. Analysis showed that 270 (71%) of these breaches involved possible breaches of the Medicines Act. The rules that forbid misleading or unsubstantiated information and misleading claims or comparisons were broken most often. The committee found the most frequent offenders to be Organon (32 breaches), Smith Kline and French (23), Glaxo (21), A H Robins (18), Bayer (17), Merck Sharp and Dohme (17), and Lederle (16). Often the promotion of one product led to several breaches. The promotional wars over histamine H2 receptor antagonists accounted for 33 breaches. It is estimated that in 1983-8 about 100 breaches of the code were detected a year. In the 18 years 1972-88 the Medicines Act was breached probably over 1200 times. Health ministers, by not enforcing the regulations controlling promotion, have abrogated their responsibility to the ABPI, but the evidence suggests that the code has failed to deter promotional excesses. The ABPI's wish to secure compliance with the code seems weaker than its wish to pre-empt outside criticism and action: its self regulation seems to be a service to itself rather than to the public. It is suggested that the code of practice committee should become publicly accountable, that the majority of its members should represent the health professions and the public, and that effective sanctions are needed.

Advertising↗
PubMed1990

Biphasic response to acetylcholine in human veins in vivo: the role of the endothelium.

1. The dose-response to acetylcholine has been examined in dorsal hand veins of healthy volunteers before and after removal of the endothelium. 2. Measurements were made in single dorsal hand veins during local infusions of acetylcholine. The vein was irrigated with distilled water to remove the endothelium. Dilator studies were performed in vessels preconstricted by a continuous infusion of noradrenaline. 3. In the endothelium-intact vessel the dose-response to acetylcholine was biphasic; low doses produced venodilatation with higher doses causing venoconstriction. 4. Dilatation to low doses of acetylcholine was abolished by prior irrigation with distilled water, consistent with denudation of the endothelium by this process. Irrigation augmented the constriction seen in response to higher doses of acetylcholine. 5. This is the first demonstration of an endothelium-dependent biphasic dose-response to acetylcholine in man. The results raise questions as to the possible physiological actions of endogenous acetylcholine and as to the use of the acetylcholine dose-response curve as a marker of endothelial function.

Acetylcholine↗
PubMed1990

Isolation and structural characterization of a cDNA clone encoding the human DNA repair protein for O6-alkylguanine.

O6-Methylguanine-DNA methyltransferase (MGMT; DNA-O6-methylguanine:protein-L-cysteine S-methyltransferase, EC 2.1.1.63), a unique DNA repair protein present in most organisms, removes the carcinogenic and mutagenic adduct O6-alkylguanine from DNA by stoichiometrically accepting the alkyl group on a cysteine residue in a suicide reaction. The mammalian protein is highly regulated in both somatic and germ-line cells. In addition, the toxicity of certain alkylating drugs in tumor and normal cells is inversely related to the levels of this protein. The cDNA of the human gene, henceforth named MGMT, has been cloned in an expression vector on the basis of its rescue of a methyltransferase-deficient (ada-) Escherichia coli host. A 22-kDa active methyltransferase encoded entirely by the cDNA contains an amino acid sequence of 61 residues that bears 60-65% similarity with segments of E. coli methyltransferase (products of the ada and ogt genes), which encompass the alkyl-acceptor residues. The human cDNA has no sequence similarity with the ada and ogt genes, due in part to differences in codon usage, and shows no detectable homology with E. coli genomic DNA. However, it hybridizes with distinct restriction fragments of human, mouse, and rat DNAs. The lack of methyltransferase observed in many human cell lines is due to the absence of the MGMT gene or to lack of synthesis and/or stability of its 0.95-kilobase poly(A)+ RNA transcript.

Amino Acid Sequence↗
PubMed1990

Use of carbamazepine in psychosis after neuroleptic malignant syndrome.

A case is described of NMS during treatment with sulpiride. The subsequent psychosis resolved during treatment with carbamazepine. It is proposed that this patient may have suffered from a supersensitivity psychosis, and that resolution of her post-NMS psychosis could have been spontaneous.

Carbamazepine↗
PubMed1989

Effects of endothelium-derived nitric oxide on peripheral arteriolar tone in man.

NG monomethyl-L-arginine (L-NMMA), a specific inhibitor of the synthesis of endothelium-derived nitric oxide (NO), was infused into the brachial arteries of healthy volunteers to study the role of NO in the control of forearm blood flow. L-NMMA caused a 50% fall in basal blood flow and attenuated the dilator response to infused acetylcholine but not that to glyceryl trinitrate. These results indicate that the dilator action of endothelium-derived NO contributes to the control of basal and stimulated regional blood flow in man. Impairment of production of NO might account for the abnormalities in vascular reactivity that characterise a wide variety of disease states.

Acetylcholine↗
PubMed1989

Nitric oxide synthesised from L-arginine mediates endothelium dependent dilatation in human veins in vivo.

Endothelium derived relaxing factor (EDRF) has been identified as nitric oxide, synthesised from the amino acid L-arginine, a process which is inhibited by the L-arginine analogue NG-monomethyl L-arginine (L-NMMA). We have studied the effect of local infusions of L-NMMA on venous reactivity in healthy volunteers. Studies were performed using the veins on the back of the hand. The diameter of a single dorsal hand vein was measured in healthy subjects who had taken 600 mg of aspirin 30 min before the experiment. Changes in diameter were recorded during local infusions of noradrenaline, bradykinin, acetylcholine, glyceryl trinitrate, L- and D-arginine and its NG-monomethyl derivatives. L-NMMA (100 nmol.min-1) stereospecifically inhibited vasodilatation induced by acetylcholine and bradykinin (p less than 0.02) but not that induced by the endothelium independent vasodilator glyceryl trinitrate. L-NMMA (100 nmol.min-1) potentiated the venoconstrictor effect of a high dose of acetylcholine (100 nmol.min-1) without affecting the action of noradrenaline and without having a direct venoconstrictor effect in doses up to 10 mumol.min-1. These results show that the venous effects of certain vasodilators in man are mediated through the release of nitric oxide (EDRF) synthesised from L-arginine. They also highlight differences in basal and stimulated production of nitric oxide between arteries and veins.

Adult↗
PubMed1988

Marital problems and sexual dysfunction: how are they related?

In a study of 28 attenders of a sexual and marital clinic, the relationship between marital distress and both general and specific sexual dysfunctions was investigated. It was found that for men there was a much closer relationship between sexual and marital problems than for women. In particular, it was noted that the specific male sexual dysfunctions of impotence and premature ejaculation played a much larger part in marital discord than did the female dysfunctions of anorgasmia and vaginismus.

Adolescent↗
PubMed1986

Clinical experience with sorbinil--an aldose reductase inhibitor.

A considerable volume of animal pharmacologic data support the view that increased flux through the polyol pathway provides a unifying hypothesis for the major complications of diabetes. An extensive clinical program has been established to verify the extrapolation of the animal pharmacologic findings to man. Clinical data accumulated to date confirm the biochemical and electrophysiologic effects, and encouraging evidence of a drug effect in diabetic neuropathy and retinopathy has already been observed. In the large, controlled safety data base already available, the long-term clinical use of sorbinil is devoid of significant adverse effects in terms of both subjective side effects and laboratory parameters. The only clinically important adverse reaction reported to date has been a hypersensitivity reaction in the early weeks of therapy, which is similar to that seen with other hydantoins.

Aldehyde Reductase↗
PubMed1986

Questionnaire assessment of patients' attitudes and beliefs about asthma.

The feasibility, face validity and repeatability of a self-complete questionnaire to assess patients' attitudes and beliefs about asthma was evaluated in 45 adult patients attending a hospital asthma clinic. The questionnaire consisted of 40 statements with which the patient agreed or disagreed by placing an 'X' along a visual analogue line. Patients completed questionnaires at their clinic consultation and then were interviewed to ascertain whether questionnaire responses agreed with a verbal description of their attitudes and beliefs. Repeatability was assessed by having patients complete an identical questionnaire four weeks after their interview. The questionnaire responses showed excellent agreement with interview findings, suggesting that face validity was good. Repeatability also appeared satisfactory in that agreement between responses on the first and second questionnaires was significant for 31 of the 40 items. Many patients (22%) incorrectly used the analogue line response scale making feasibility unacceptably low. However, subsequent studies showed this problem could be overcome by the use of a four-point Likert response scale. These findings suggest that this questionnaire is a satisfactory instrument for assessing patients' attitudes and beliefs about asthma. Its face validity appeared good and, with certain modifications, it was both feasible and repeatable.

Adolescent↗