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Biomedical subjects

J A Rees

Publications and source records attributed to J A Rees.

At least 37 records · Page 2Linked to original sources
PubMed1984

A communication aid for the physically handicapped.

A communications aid for the severely handicapped is described. The aid is primarily intended to be mounted on an electric wheelchair and to be powered from the chair's battery. It may be operated by any two-switch input system or by more elaborate controls such as joy-sticks. The central unit of the aid is a purpose-built 8085 microcomputer, the operating program and data tables being sorted in a 2 kbyte EPROM. The input control is used to drive a cursor around an 8 X 8 letter board array, the selected alphanumeric character being output to a liquid crystal display. Up to 64 messages, each of no more than 15 characters, can be composed and stored by the user and recalled as required. The messages are stored in a 2 kbyte CMOS memory and are retained when the aid is switched off. It is a simple matter to increase the number of stored messages. The aid was designed with the needs of a particular 15 year old, athetoid child in mind and the results of his tests of the aid will be briefly discussed.

Biomedical Engineering↗
PubMed1983

The effect of flurbiprofen on the responses to frusemide in healthy volunteers.

Ten subjects participated in a four-way, open, crossover study to investigate the effect of frusemide, flurbiprofen, flurbiprofen plus frusemide, and placebo on urinary volume, sodium, and potassium. Compared with placebo, flurbiprofen was shown to significantly reduce all three parameters. The diuretic effect of frusemide was reduced by the addition of flurbiprofen but not to a statistically significant degree. The reduction was less than in previous reports using indomethacin. As flurbiprofen is a more potent inhibitor of prostaglandin synthesis than indomethacin, these data cast doubt on the theory that nonsteroidal anti-inflammatory drugs antagonize the action of diuretics by prostaglandin synthetase inhibition. The methods for assaying the two drugs are described. A pharmacokinetic explanation of the reduction of the diuretic effects of frusemide by flurbiprofen was sought but not found.

Adult↗
PubMed1980

Chemical ionisation mass fragmentographic measurement of dothiepin plasma concentrations following a single oral dose in man.

A method is described for the measurement of the antidepressant drug dothiepin in human plasma. The procedure involves the addition of deuterodothiepin as an internal standard, extraction and measurement by chemical ionisation mass fragmentography. The minimum measurable concentration of 0.5 ng/ml enabled the pharmacokinetics of dothiepin in man to be studied after a single oral dose of 75 mg of dothiepin hydrochloride. Unlike other tricyclic antidepressants the apparent half-life of elimination (approximately 24 h) showed very little intersubject variation. However, the apparent volume of distribution was much more variable and could account for the wide range of steady state concentrations which have been found in patients taking dothiepin.

Administration, Oral↗
PubMed1980

A double-blind comparison of dothiepin and amitriptyline in patients with primary affective disorder: serum levels and clinical response.

In a double-blind parallel group study, thirty-two patients suffering from a primary affective disorder received either dothiepin or amitriptyline. Serum concentrations of total dothiepin plus northiaden or amitriptyline and nortriptyline were estimated. A similar therapeutic response was seen with both drugs but there was no correlation with serum concentrations of amitriptyline or nortriptyline, whereas serum dothiepin correlated positively with clinical response.

Adult↗
PubMed1977

Steady-state serum concentrations of dothiepin and northiaden after two dosage regimens of dothiepin hydrochloride (Prothiaden).

Five healthy volunteers took part in a crossover study which examined the serum concentrations of dothiepin and northiaden after a 25 mg three times a day and a 75 mg once a day dosage regimen of Prothiaden. The inter-individual variation of serum levels was large after either schedule which is to be expected with this group of drugs. The minimum steady-state level of dothiepin tended to be lower after the single daily dose, but the differences were small and not statistically significant. The approximate maximum steady-state levels of dothiepin showed large intra-and inter-subject variation and no obvious trend. The values of the desmethylated metabolite, norhiaden, tended to follow the dothiepin concentrations but were lower than the parent drug. Average steady-state levels tended, with one exception, to be very similar after both regimens with no evidence with no evidence fo any trend when comparing the two regiments. The study showed that the two regimens yielded similar steady-state serum concentrations both of drug and metabolite but inter-individual differences were large.

Adult↗
PubMed1976

An evaluation of a once daily dosage régime of dothiepin hydrochloride (prothiaden).

This paper reports on the use of a single daily dose of dothiepin hydrochloride (Prothiaden). The results from a metabolism study using [14C] dothiepin were used to calculate the daily variations in blood levels after once daily and thrice daily dose regimes. A clinical study on the use of a single daily dose of 75 mg of dothiepin showed this type of regime to be well tolerated and efficacious in the treatment of 105 depressed patients in general practice. Compared to a thrice daily regime the once daily dose appeared to be more beneficial on symptomatic insomnia during the early treatment period.

Adult↗
PubMed1976

A single-blind comparative study of once daily dothiepin ("Prothiaden") and divided daily doses of amitriptyline.

Forty-eight patients took part in a single-blind clinical trial comparing a once daily dose of dothiepin (75 mg) and 25 mg 3-times a day of amitriptyline. The results showed that dothiepin caused a greater improvement than amitriptyline after 4 weeks of treatment as judged by depression scores, total scores and global assessments. The incidence of side-effects was less with dothiepin and in those patients who actually reported side-effects the severity was much less with dothiepin than with amitriptyline.

Adult↗
PubMed1975

Lymphocyte reactivity in patients with carcinoma of the breast and large bowel.

The reactivity of lymphocytes from patients with either carcinoma of the breast or large bowel has been studied using the human to mouse normal lymphocyte transfer (NLT) reaction. It was found that, in the case of breast cancer, there was a direct correlation between the clinical stage and a reduced NLT reaction. Only patients with regional lymph node or generalized metastases showed significantly reduced lymphocyte reactivity. However, in the case of large bowel cancer there was a generalized reduction in NLT reactivity which was independent of the clinical stage. Incubation of lymphocytes from individuals without neoplastic disease in serum or plasma from breast cancer patients, showing reduced NLT reactivity, resulted in a reduced NLT reaction. This appears to be indicative of the presence of circulating "blocking factor" in such patients.

Aged↗
PubMed1975

Some relations between dissolution rates and physical parameters of a drug in aqueous micellar solutions of a non-ionic surfactant.

Dissolution rates of salicylic acid from a constant surface area into a series of aqueous micellar polysorbate 20 solutions at pH 1-0 to 4-0 have been measured using two different methods; a stirred beaker and a rotating disc technique. The micellar molecular weight of polysorbate 20 has been obtained from light scattering and differential refractometry data and used with other independently determined physical data to calculate diffusion coefficients of the diffusing species. Linear multiple regression analysis was used to assess the dependence of drug dissolution rate on the diffusion coefficient and the viscosity of the dissolution medium.

Colloids↗
PubMed1975

The outcome of dothiepin treatment in 1,900 depressed patients.

One thousand, nine hundred and sixty-five depressed patients took part in a multicentre study of dothiepin hydrochloride, which involved 392 doctors. The results indicated that a large percentage of patients improved as measured by all the assessments and no serious or adverse effects were encountered. A good correlation was seen between the global scale and the Rockliff depression scale; and also between the final mean Rockliff score and the number of patients stopping therapy due to recovery, and continuing treatment until recovery, at the final assessment.

Adolescent↗
PubMed1974

A method of comparing differences in tumour growth rates applied to a study of the increasing growth capacity of mouse carcinomata.

A method of comparing differences in growth rates of tumours in small groups of animals is described. A common slope can be fitted to the growth curves of a given tumour in a group of isogeneic animals. Differences between growth potentials can be demonstrated by comparing the common slope for a given tumour against that of another tumour (or the same tumour at a later stage of development).A highly significant difference is shown between the growth potential of an A-strain mammary carcinoma after 7 or after 28 days' growth in isogeneic animals. Since this increase in autonomy is reflected in the tumour's subsequent growth rate in secondary hosts, it is suggested that it involves adaptation of the tumour rather than progressive immunodepression of the primary host.

Animals↗