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Biomedical subjects

J Evans

Publications and source records attributed to J Evans.

At least 397 records · Page 22Linked to original sources
PubMed1988

Phenobarbital does not alter phenytoin steady-state serum concentration or pharmacokinetics.

Phenytoin pharmacokinetics and biotransformation were studied with stable isotope tracer techniques in six patients before and after addition of phenobarbital. No significant (p less than 0.05) changes in phenytoin serum concentration, clearance, elimination half-life, volume of distribution, or clearance via production of p-hydroxyphenyl-phenylhydantoin or phenytoin dihydrodiol occurred after addition of phenobarbital. Thus, frequent phenytoin serum concentration determinations or a change in phenytoin dosing rate are probably not necessary after adding phenobarbital.

Adult↗
PubMed1988

Iron deficiency in inner city pre-school children: development of a general practice screening programme.

Iron deficiency in children has been associated with behavioural disorder and developmental delay. Screening for iron deficiency was offered to all 527 children aged between one and four years in an inner city practice. Half the children belong to an ethnic minority group, and there is widespread social deprivation in the area. Capillary haemoglobin concentration and mean corpuscular volume were estimated in 365 children (69%). Dietary history, birth weight and current weight were also recorded. Fifty-eight (16%) of the children were iron deficient as defined by a mean corpuscular volume of less than 75 fl and/or a haemoglobin concentration of less than 10.5 g dl(-1). All were hypochromic and among 23 tested all had serum ferritin levels below 10microg I(-1). Twenty-one children (5.8%) were anaemic (haemoglobin concentration less than 10.5 g dl(-1)). Anaemia was significantly more common among children who were currently underweight but was not related to weight at birth. Iron deficiency was significantly more prevalent in non-Caucasian children - 25.0% compared with 7.8% of Caucasian children. There was also a significant linear decrease in iron deficiency with increasing age. Sex, weight at birth, current weight, whether breast fed, age weaned or whether on a vegetarian diet were not significant factors in iron deficiency. Iron supplements were given to all the children with iron deficiency.In view of the high prevalence of iron deficiency, all children in the practice are now routinely offered screening for iron deficiency at the age of 14 months. The programme has been welcomed by all parents. It is suggested that screening for iron deficiency should be part of routine child surveillance.

Anemia, Hypochromic↗
PubMed1988

Thoracic outlet syndrome: a comprehensive evaluation.

Using various modalities, 480 patients were evaluated for thoracic outlet compression syndrome. Of this group, 300 patients were eventually diagnosed as having thoracic outlet syndrome after extensive evaluation. Ninety of these patients underwent a total of 103 operative procedures for thoracic outlet decompression. Nerve conduction velocities and directional Doppler studies were the most useful adjuncts in making the diagnosis. Surgical therapy after proper selection yielded an 80.6 per cent long-term "good" operative result and an additional 6.9 per cent long-term "fair" operative result in follow-up to 12 years.

Adult↗
PubMed1987

Pharmacology of L-655,240 (3-[1-(4-chlorobenzyl)-5-fluoro-3-methyl-indol-2-yl]2,2-dimethylpro pan oic acid); a potent, selective thromboxane/prostaglandin endoperoxide antagonist.

L-655,240 (3-[1-(4-chlorobenzyl)-5-fluoro-3-methyl-indol-2-yl]2,2-dimethylpropa noic acid) has been studied in vitro on the guinea-pig tracheal chain, pulmonary artery and thoracic aorta ring and shown to be a potent, competitive antagonist of contractions induced by the prostaglandin endoperoxide analogue, U-44069 (pA2 values 8.0, 8.4 and 8.0 respectively). Selectivity on the guinea-pig trachea was indicated by non-competitive antagonism of contractions induced by prostaglandin D2 and minimal activity against contractions induced by leukotriene D4, prostaglandin F2 alpha, serotonin, histamine and acetylcholine. L-655,240 was a potent inhibitor of the aggregation of washed human platelets induced by U-44069 (IC50 value 7 X 10(-9) M) and inhibited aggregation of human platelet rich plasma induced by U-44069, U-46619, thromboxane A2 and collagen but not ADP or platelet activating factor. In vivo i.v. L-655,240 administered to guinea-pigs inhibited bronchoconstriction induced by i.v. U-44069 and arachidonic acid (ED50 values 0.09 and 0.23 mg kg-1) but not histamine, acetylcholine or serotonin. When administered to rhesus monkeys (3 and 10 mg/kg p.o.), L-655,240 inhibited ex vivo platelet aggregation induced by U-44069 but not ADP. It is concluded that L-655,240 is a potent, selective, orally active thromboxane/prostaglandin endoperoxide antagonist.

Animals↗
PubMed1987

Plasma albumin concentrations and intestinal permeability in Bangladeshi children infected with Ascaris lumbricoides.

Plasma albumin concentration and intestinal permeability have been investigated in Bangladeshi children before and 9-14 d after successful treatment for ascariasis. Children infected with A. lumbricoides had lower plasma albumin concentrations than counterparts not harbouring this worm and values increased with successful treatment. Intestinal permeability tests indicated that the children had impaired gastrointestinal function and some loss of mucosal integrity; these factors had not improved 9-14 d after A. lumbricoides expulsion. The lowered nitrogen nutritional status implied by the reduced plasma albumin values in infected children, and the improvement following treatment, are in keeping with previous reports that A. lumbricoides impairs protein digestion or absorption. This may be the basis of the better growth rates of dewormed children in this area.

Anthelmintics↗
PubMed1987

Residential care of youth: convergent versus divergent thinkers.

Effective residential care of disturbed adolescents depends on the treatment programmes being integrated. Readily achievable with defined illness, special difficulties exist when dealing with disturbed adolescents. For a unit to be successful an important function of its director is monitoring the therapeutic input so the recurring but inevitable conflicts of aims (e.g. encouraging independence of adolescents but maintaining control of unit functioning) do not render staff ineffective. Amongst the qualities required are a capacity to be at ease with divergent thinking.

Adolescent↗
PubMed1987

Quantitation of aortic regurgitation by computer analysis of digital subtraction angiography.

Digital subtraction angiography provides the potential to determine aortic regurgitant fraction by computer analysis of time-intensity curves generated from regions of interest positioned over the aorta and left ventricle after aortography. To validate this ability, we studied six dogs instrumented with an electromagnetic flow probe on the ascending aorta. Aortic regurgitation of varying severity was produced by a basket catheter introduced through the right carotid artery. Aortograms were performed using continuous fluoroscopy at 30 frames/s and stored in digital format in a 256 x 256 pixel matrix. An image-processing computer was utilized to plot summated pixel intensity versus time for both the aortic and the left ventricular regions of interest. Regurgitant fraction was calculated from the time-intensity curves using an algorithm analogous to that employed by dye-dilution methods. Regurgitant fraction determined from digital angiography was compared with that obtained by electromagnetic flow and was found to correlate well (r = 0.94, SEE = 7.4%) over a wide range of values. Thus, these data indicate that aortic regurgitant fraction can be accurately determined from computer analysis of digitally acquired aortograms in an animal model of acute aortic regurgitation.

Animals↗
PubMed1987

Early intravenous indomethacin prolongs respiratory support in very low birth weight infants.

Infants weighing 1500 g at birth requiring either intermittent positive pressure ventilation or continuous positive airway pressure by 12 hours of age were entered in a randomized double blind controlled trial to test the efficacy of early intravenous indomethacin therapy in preventing chronic pulmonary disease of prematurity. Of the 30 newborns enrolled, 15 were treated with indomethacin and 15 were treated with placebo at 12, 24 and 36 hours of age. The groups were similar for birth weight, gestational age, sex, hyaline membrane disease and intracranial hemorrhage. Infants in the placebo group were successfully weaned from intermittent positive pressure ventilation at an earlier age than infants in the indomethacin group (p less than 0.05). Furthermore, chronic pulmonary disease of prematurity was similar in the two groups despite a reduction in the incidence of patent ductus arteriosus in the indomethacin group.

Clinical Trials as Topic↗
PubMed1987

A comparison of psychotropic drug use between the general population and clients of health and social service agencies.

The purpose of this research was to study the epidemiology of psychotropic drug use among the general population and to draw comparisons to drug use among clients of medical, mental health, and social services in the same jurisdiction. Results showed considerably higher percentages of users for all drug categories among agency clientele. Age and sex differences in drug use replicated previous research in the general population but were noticeably absent among the clients of local services. Notably, the proportion of long-term daily users of minor tranquilizers in the agency population was about three times that of the general population. However, tranquilizer users in the two populations were similar in many respects. Results of the study are discussed in terms of the need for screening for persons with psychotropic drug problems in health and social services.

Adult↗