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Biomedical subjects

A Fulton

Publications and source records attributed to A Fulton.

36 records · Page 2Linked to original sources
PubMed1984

The effects of benzodiazepines on hormones in women with idiopathic hirsutism.

A single blind study was planned to investigate whether benzodiapines would reduce androgens in women with idiopathic hirsutism. Placebo was given for the first month followed by four months of a benzodiazepine (chlorazepate 15 mg nocte or diazepam 10 mg nocte ). Plasma samples were collected during the follicular and luteal phases of each therapy month. Hair growth was assessed monthly. Eighteen women concluded the five months of the trial of whom ten received chlorazepate and eight diazepam. Comparison of follicular plasma samples during the placebo phase and fourth month of benzodiazepine found a significant increase in sex hormone binding globulin and a significant decrease in dehydroepiandrosterone sulphate with benzodiazepine therapy. No significant effects on hair growth were observed. A longer therapy time may be needed to demonstrate effects of benzodiapines on hirsutism. Further studies are needed to determine whether benzodiazepines affect hormonal parameters in normal men and women.

Adult↗
PubMed1984

Benzodiazepine anxiolytic action and affinities for serotonergic and adrenergic receptors.

Tissue homogenates were prepared from brains of four week old Lewis rats. 5HT receptors were prepared from three brain regions and labelled with 3H-5HT and 3H-spiperone. Alpha-receptors were prepared from rat forebrains and labelled with 3H-WB4101 and 3H-clonidine. Incubations were carried out at seven concentrations for each of twelve benzodiazepines. IC50 values were derived from specific binding versus log (drug concentration) plots. The benzodiazepines appeared to have little affinity for 5HT or NA post-synaptic receptors in rat brain.

Animals↗
PubMed1982

Assessment of the antidepressant activity of dothiepin and its metabolites by preclinical tests.

The affinities of dothiepin and its principal metabolites northiaden, dothiepin sulphoxide and northiaden sulphoxide for [3H]imipramine binding sites in the rat cortical homogenates, and for [3H]spiperone and [3H]serotonin receptor sites in preparations from the rat frontal cortex and hippocampus were studied. As inhibitors of [3H]imipramine binding, the strengths of the drugs are, in terms of their IC50 (concentration corresponding to 50% inhibition): dothiepin 2.8 X 10(-6) M, northiaden 5.0 X 10(-6) M, northiaden sulphoxide 4.0 X 10(-5) M and dothiepin sulphoxide 3.2 X 10(-5) M. The potencies of the drugs in inhibiting serotonergic binding followed a similar trend. Using frontal cortical tissue suspensions and [3H]spiperone, the IC50 values were determined to be: dothiepin 4.2 X 10(-6) M, northiaden 5.0 X 10(-6) M, northiaden sulphoxide 1.6 X 10(-4) M and dothiepin sulphoxide 1.6 X 10(-4) M; whereas in hippocampal suspensions and using [3H]serotonin, the IC50 values were 2.5 X 10(-6) M, northiaden 4.0 X 10(-5) M, dothiepin sulphoxide 2.5 X 10(-4) M and northiaden sulphoxide greater than 10(-3) M. The influence of the drugs on the uptake of [14C]serotonin into human platelets was also investigated. All had an inhibitory effect upon the uptake, the order of potency being dothiepin greater than northiaden greater than northiaden sulphoxide greater than dothiepin sulphoxide. Plots of 1/v versus 1/s showed that the inhibition was competitive for all four compounds.

Animals↗
PubMed1982

Ligand binding and platelet uptake studies of loxapine, amoxapine and their 8-hydroxylated derivatives.

Loxapine, amoxapine and their 8-hydroxylated derivatives were studied by means of [3H]imipramine binding to rat cortical membranes, [3H]spiperone binding to rat striatal membranes, and the inhibition of serotonin uptake by human platelets. As inhibitors of [3H]imipramine binding: amoxapine greater than hydroxyamoxapine greater than loxapine = hydroxyloxapine; as inhibitors of platelet serotonin uptake: hydroxyamoxapine greater than amoxapine greater than hydroxyloxapine greater than loxapine; and as inhibitors of [3H]spiperone binding: loxapine greater than amoxapine greater than hydroxyamoxapine greater than hydroxyloxapine. The antipsychotic properties of loxapine and amoxapine were supported by the binding results, which also indicated the probable antipsychotic activities of the metabolites. All 4 compounds may possess dual action of antidepressant effect as well as antipsychotic effect.

Amoxapine↗
PubMed1981

Pharmacokinetics of N-desmethyldiazepam after a single oral dose of clorazepate: the effect of smoking.

The pharmacokinetics of N-desmethyldiazepam was evaluated after oral administration of clorazepate 20 mg to 12 healthy male volunteers (6 smokers; 6 non-smokers), aged 23-29 years. Plasma levels of desmethyldiazepam were measured by gas liquid chromatography. The half life of elimination (t1/2 beta) was significantly longer in the non-smoking volunteers than in the smokers: 54.7 +17.7 versus 29.8 +9.9 h (p less than 0.05). Peak plasma concentrations (Cmax) were higher in non-smokers than in smokers, 413 +106 micrograms/l and 245 +50 micrograms/l, respectively (p less than 0.05). The sedative effect of clorazepate was less severe in smokers than in non-smokers.

Administration, Oral↗
PubMed1981

The value or arthrography in the management of internal derangements of the knee: the first 1000 are the worst.

The acceptance of arthrography of the knee as an accurate diagnostic procedure by both radiologists and orthopaedic surgeons in the United Kingdom has been slow compared to many other parts of the world. The value of arthrography in the diagnosis of meniscal lesions is discussed with reference to the first 1000 documented cases in the authors' series. It is considered that the results obtained from such early experience is more relevant to those about to start as an arthrographic service. Problems in clinical, arthrographic and arthroscopic diagnosis are discussed. Arthrography constitutes an accurate method of diagnosing such lesions and should be employed whenever clinical doubt about the diagnosis of an internal derangement of the knee is encountered. In a selected group of 137 patients, in whom both arthrography and arthroscopy was performed, the two investigations showed a comparable accuracy of 89.8 and 88.3% respectively.

Adolescent↗
PubMed1979

Antitumor activity of Listeria monocytogenes on a guinea pig fibrosarcoma.

Listeria monocytogenes-mediated tumor inhibition was studied in strain 13 guinea pigs by using a methylcholanthrene-induced fibrosarcoma (MCA-1). Mixtures of Listeria and tumor cells in ratios of 1:100, 1:200, or 1:400 (Listeria:MCA-1 cells) led to significant suppression of tumor growth. Intralesional injection of tumors on day 6 posttransplantation led to the regression of a highly significant number of tumors. Animals receiving injections of Listeria, either in a mixture with tumor cells or intralesionally, displayed enhanced skin test reactivity to a tumor extract. Tumor regressors were resistant for at least 2 to 3 months after the initial transplant to rechallenge with MCA-1 cells. Thus, with this particular tumor-host system, Listeria was successfully employed as an antitumor agent with no visibly detrimental side effects to the host.

Animals↗
PubMed1978

Subcutaneous ancrod after operation for fractured hip--a dose-ranging and feasibility study.

We have conducted a dose-ranging and feasibility study of daily subcutaneous injections of ancrod (Arvin) as a potential antithrombotic method in 28 patients following operation for fractured neck of femur. Sustained, predictable fibrinogen depletion during the first post-operative week was induced by four different regimes. A total dose of 10 units/kg weight, given in divided doses starting on the day of operation, is suggested as a possible antithrombotic regime. Ancrod treatment produced a rise in fibrinogen/fibrin degradation products, prolongation of the thrombin clotting time, and a fall in plasminogen, plasma fibrinogen and corrected blood viscosity were observed in 14 control patients. Plasma fibrinogen was correlated with plasma viscosity and corrected blood viscosity. No adverse effects of treatment occurred. Subcutaneous ancrod appears to be a simple, safe, and feasible potential antithrombotic method, and merits trials of efficacy in the prevention of post-operative thromboembolism.

Adult↗
PubMed1978

Enflurane nephrotoxicity and pre-existing renal dysfunction.

This study provides the first morphological evidence of significant structural damage following high doses of enflurane alone and confirms previous findings of transient renal functional abnormalities following high dosage enflurane. The study also indicates that enflurane may have a greater potential for renal toxicity in the presence of renal impairment. Treatment of Fischer 344 rats with a nephrotoxic dose of gentamicin prior to six hours of enflurane (GE) anaesthesia at 1 MAC resulted in increased serum concentration of the enflurance metabolite inorganic fluoride (GE, 43.9 +/- 1.5; E, 34.5 +/- 1.8 mu mol/L), increased urine flow rate and a greater degree of structural damage in renal proximal convoluted tubule cells than was observed with either gentamicin (G) or enflurane (E) alone. Treatment with gentamicin prior to enflurane also resulted in reduced urinary osmolality compared to enflurane or gentamicin alone (GE, 742 +/- 57; E, 1709 +/- 66; G, 985 +/- 32 m0sm/kg).

Anesthesia, Inhalation↗
PubMed1977

Bacteriological and histopathological evaluation of guinea pigs after infection with Listeria monocytogenes.

Randomly bred guinea pigs were infected with Listeria monocytogenes using the intracardial, intravenous and intraperitoneal routes of infection. Doses of Listeria ranged from 5 to 1,000 x the 50% lethal dose based on the 50% lethal dose for intracardially injected Listeria. A complete necropsy was performed on all animals that died after infection. Gross and microscopic examination of tissues revealed major pathological features which include myocarditis, edema and congestion with interstitial pneumonitis present in the lungs, and fatty hepatic changes with focal necrosis. For all or a majority of the animals, large numbers of Listeria were likewise recovered from these organs and from lymph nodes, spleen, kidneys, and adrenal gland tissue. Of the three routes of infection used, guinea pigs were most susceptible to Listeria injected via the intracardial route. The relatively high lethal dose of listeric for the quinea pig, however, suggests that the organism is a low-grade pathogen for this species.

Animals↗
PubMed1976

Gastrointestinal sarcoidosis diagnosed by conjunctival biopsy.

Ophthalmologic examination of a 31-year-old black man presenting with an intractable gastric ulcer revealed small conjunctival nodules in the lower cul-desac that were sarcoid granulomas by microscopy. Previous endoscopic examination had revealed polyps in the gastric antrum, and a biopsy and microscopic examination had revealed granulomatous lesions, but a definite diagnosis could not be made until the ophthalmoscopic examination.

Adult↗
PubMed1975

Initial experience with a small dedicated computer system in a diagnostic x-ray department.

The operation of a small computer system involved in day to day management in an X-ray department is described. The system consists of the following equipment: PDP 8/F central processor with 8K core storage, 32K magnetic disc storage, High-speed paper tape reader (300 characters/s) and punch (50 characters/s), 3 Olivetti TE318 terminals with sprocket feed, paper tape reader and punch (10 characters/s). The system stores patient data relating to name, address, age, ward, referring physician, examination(s) requested, date of request, date of examination, date of report. From this data a large volume of relevant statistics is made available to the department and to the health authority. Labels for identifying record card, film envelope and X-ray films are automatically typed. During reporting coded phrases can be used by the radiologist. Interesting films can be recorded and recalled for library or consultation purposes as can research items. At report typing stage, the report heading is automatically recalled from the computer store. Coded phrases are typed automatically as is the radiologist's name and the date of the report. A 'DAYBOOK' IS TYPED AUTOMatically at the end of each working day. Problems encountered in running the system and future developments are described.

Computers↗