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Biomedical subjects

P Wilkinson

Publications and source records attributed to P Wilkinson.

At least 109 records · Page 6Linked to original sources
PubMed1985

Further data on the distribution of biting midges in southern Europe and the Mediterranean area, with special reference to Culicoides imicola.

Studies on the Culicoides midges of Spain and Turkey suggest that the range of C. imicola may extend to about 40 degrees N. However, catches of midges from mainland Greece, Sicily and Italy failed to reveal the presence of this species. These findings are discussed in the light of the possibility of the occurrence of bluetongue (BT) disease in these areas, consequent upon windborne spread of infected vectors from countries where the disease is endemic.

Animals↗
PubMed1984

Clinical trial of hyposensitisation in hay fever: two methods of relating symptom scores to daily pollen counts.

Two methods of relating daily pollen counts to patients' symptom scores in clinical trials of hyposensitisation in hay fever are described. The problems involved in comparing results from different centres and years of a trial are discussed with particular reference to symptoms which are not pollen related. The Normalised Regression method is a powerful technique, but often the Pollen Interval method is preferable on the grounds of simplicity of communication and calculation.

Clinical Trials as Topic↗
PubMed1984

A randomized study comparing chemotherapy alone with chemotherapy followed by radiotherapy in patients with pathologically staged IIIA Hodgkin's disease.

This paper reports the five-year follow-up (range, 1-8 years) of 56 patients with pathologic stage IIIA Hodgkin's disease randomized for chemotherapy alone or chemotherapy followed by radiotherapy to previous areas of disease (26 treated with mustine, vinblastine, procarbazine, and prednisolone [MVPP] alone, 30 with MVPP and radiotherapy). Of the 56 patients 53 (95%) achieved a complete remission with chemotherapy and of these only five (9%) have relapsed; three died of Hodgkin's disease. There was no improvement in relapse-free survival associated with the uses of radiotherapy following chemotherapy but in view of the small numbers of relapses and the excellent results following chemotherapy alone, a significant improvement could not be expected. The use of MVPP alone can be recommended as an alternative therapy for patients with stage IIIA Hodgkin's disease. This avoids both the physical and psychologic morbidity associated with the high relapse rate following extensive primary radiotherapy and the necessity of combined modality treatment for about half these patients. The question of whether radiotherapy should be given to areas of previous bulk following chemotherapy has not yet been answered in this trial which is continuing.

Adult↗
PubMed1983

Increased chromosomal mutation rate after hybridization between two subspecies of grasshoppers.

Hybridization between two chromosomally distinct subspecies of the grasshopper Caledia captiva results in a high incidence of novel chromosomal rearrangements among the backcross progeny. Rearrangements are restricted to those chromosomes derived from the F1 hybrid parent. Chromosomal involvement is nonrandom with the same rearrangement occurring repeatedly in different backcrosses. A single individual can also generate an array of different rearrangements among its offspring. Several of the rearrangements have also been found in natural populations. The nonrandom and recurrent nature of these chromosomal mutations at high frequencies provides a plausible explanation for the establishment and fixation of chromosomal rearrangements in natural populations.

Animals↗
PubMed1983

Trimazosin in chronic congestive heart failure: improved left ventricular function at rest and during exercise.

The hemodynamic effects of the oral vasodilator trimazosin were evaluated in patients with chronic congestive heart failure (CHF), initially over a 72-hour period (13 patients), and after 3 months of maintenance therapy (seven patients). During the initial evaluation, cardiac index and stroke work index increased an average of 24% and 37% respectively, and pulmonary capillary wedge pressure decreased by 26%. These beneficial hemodynamic effects were maintained during supine bicycle exercise. After 3 months of maintenance therapy, cardiac index (+30%) and stroke work index (+38%) remained elevated, and pulmonary capillary wedge pressure was lower (-38%). Improved hemodynamics during exercise were also seen after maintenance therapy. Withdrawal of trimazosin was associated with deterioration in hemodynamics and left ventricular function. Thus trimazosin has the potential to cause sustained improvement in left ventricular function, both at rest and during exercise, in patients with chronic CHF.

Adrenergic alpha-Antagonists↗
PubMed1982

Intermittent high-dose cyclophosphamide with and without prednisolone: a study of the relationships between toxicity, response and survival in metastatic lung cancer.

Fifty-seven patients with metastatic lung carcinoma were treated with either high-dose cyclophosphamide (Cy) alone or with a combination of high dose Cy and prednisolone (Pred) 100 mg/m2 orally daily for two days. The Cy was given IV on three occasions, at 1.5 g/m2, 2.5 g/m2 and 3.5 g/m2 with three-week intervals between courses. The overall response rate was 57% (18% CR), a median survival of 24 weeks (range, 6--130) for Cy alone, and 24% (3% CR), a median of 14 weeks (range, 1--94) for Cy + Pred. Patients with small cell carcinoma given Cy alone had a 69% response rate (19% CR), a median survival of seven months, and with non-small cell pathologic conditions 42% (16% CR), a median survival of 16 weeks. Performance scores and survival were better for responding patients. Addition of Pred did not improve the therapeutic efficacy of high dose Cy or ameliorate toxicity. No marked or unexpected toxicity was observed with the high-dose Cy regimen. The blood counts had returned to normal by three weeks in the great majority of patients. A short course of high-dose Cy was not associated with unacceptable side effects and the therapeutic results obtained were superior to those described for Cy at conventional dosage. High-dose Cy is of value to patients with metastatic lung cancer, and the incorporation of the regimen into chemotherapeutic combinations could be advantageous.

Adult↗
PubMed1981

Comparative assessment of two booklets about rheumatoid arthritis, intended for use by patients.

Increases in patient knowledge after reading booklets about rheumatoid arthritis demonstrated the effectiveness of written material as a teaching aid. Two groups of patients (35 and 37 in number) in a specialist hospital acted as their own controls. Group A, after reading a booklet produced by the Arthritis and Rheumatism Council, increased their scores by a mean of 21 per cent. Group B, after reading a booklet produced by the Leeds Health Education Service, and containing substantially more information, achieved a 45 per cent average increase, indicating that this is the more effective of the two. Overall low scores before reading indicate a need for more patient education.

Arthritis, Rheumatoid↗
PubMed1980

Clinical pharmacology of tamoxifen and N-desmethyltamoxifen in patients with advanced breast cancer.

Serum concentrations of tamoxifen and its metabolite, N-desmethyltamoxifen (DMT) were determined in six post-menopausal patients with advanced breast cancer. Following a single 10-mg dose PO parent drug was detected in the serum, with a peak concentration of 17.5 ng/ml. Concentrations of the N-desmethyl metabolite were below the limit of detection (less than 2.5 ng/ml). After 21 days' oral therapy with 10 mg b.i.d. the serum concentration of tamoxifen had increased ten fold, while DMT was now present in comparable amounts. Two patients were further studied for a longer time period. There was little change in the serum concentration of tamoxifen, while the DMT increased two fold above its value at 21 days.

Breast Neoplasms↗
PubMed1980

Intranasal and oral cocaine kinetics.

Plasma cocaine levels were determined in 7 subjects after intranasal and oral cocaine. Intranasal doses of 0.19, 0.38, 0.75, 1.5, and 2.0 mg/kg were given as a 10% aqueous solution; 0.38 mg/kg was given as crystalline cocaine HCl. Oral cocaine was administered in doses of 2.0 and 3.0 mg/kg. Intranasal cocaine kinetics were described by a 1-compartment open model with 2 consecutive first-order input steps and first-order elimination. Oral cocaine disposition was described by a 1-compartment open model with a lag time followed by a single first-order input phase and first-order elimination. The mean elimination half-life (t 1/2) for cocaine by the intranasal route to 7 subjects was 75 +/- 5 min (mean +/- SE). The mean t 1/2 after oral administration to 4 subjects was 48 +/- 3 min. The relative bioavailability [as determined by the area under the concentration-time curve (AUC)] for the 2.0-mg/kg dose by the intranasal and oral routes was not different. There was a linear increase in AUC with increasing intranasal dose.

Administration, Intranasal↗
PubMed1980

Observations on Onchocerca gibsoni and nodule development in naturally-infected cattle in Australia.

O. gibsoni worms were extracted from 185 nodules of a total of 370 worm nodules collected from 94 naturally infected cattle at Townsville, Australia. 183 of the 185 nodules contained a single female worm, 60% of them contained a single male worm and 7% contained two male worms. Nodules containing males alone were not found. Small nodules (less than 0.2 g) contained immature female worms without microfilariae and no males. As nodule size and female worm size increased, the number of female worms with microfilariae and the number of nodules with males increased reaching almost 100% in nodules weighing greater than 3.0 g. It is suggested that female worms normally become encapsulated when young, grow within the nodule and tht the male enters the nodule later, fertilises the female and remains in the nodule.

Animals↗
PubMed1980

Experimental infection of laboratory rodents and calves with microfilariae of Onchocerca gibsoni.

Uterine microfilariae of Onchocerca gibsoni migrated to skin of all parts of the body when inoculated into rats and mice. Higher microfilarial densities were obtained in the skin of mice compared with rats. In guinea pigs very few microfilariae migrated to the skin and densities of microfilariae were very low. Densities of skin microfilariae were lower in rats when inoculated intraperitoneally compared with inoculation by 2 subcutaneous routes. In the latter case, higher densities of microfilariae were obtained in areas of skin closer to the injection sites. Persistence of microfilariae in the skin of rats was variable but only low numbers were recovered between 21 and 70 days after infection. Microfilariae also migrated to the skin in calves experimentally infected by subcutaneous injection into the dewlap. Microfilaria were recovered consistently and in high numbers from skin snips along the ventral midline. Small numbers of microfilariae were occasionally found in skin snips from the dorsal midline.

Animals↗
PubMed1979

A comparison of chromosomal and allozymal variation across a narrow hybrid zone in the grasshopper Caledia captiva.

A hydrid zone between the Moreton and Torresian taxa of the grasshopper Caledia captiva in S.E. Queensland has been characterised in terms of allozyme and chromosome variation within the same individuals.--On chromosomal criteria (pericentric rearrangements), the zone is asymmetrical with evidence of high levels of introgression of Torresian chromosomes into the Moreton taxon. This is apparent from the analysis of two independent transects across the hydrid zone. Major changes in chromosomal frequency occur over distances of less than 0.5 km. and the level of introgression differs between the two transects, with much higher levels in the northern Moreton populations, characterised by an acrocentric X-chromosome, when compared with the southern metacentric-X Moreton populations. Chromosome analysis of samples taken from the same transect over two years has revealed no major changes in the structure of the zone. Moreover, a Moreton population located only 0.5 km. from the null point was found to be stable over 6 generations with evidence for a new balanced genome having originated following the differential incorportation of Torresian chromosomes.--Contrary to the chromosomal situation, the same hybrid zone was found to be symmetrical with respect to allozyme variation with evidence of movement of diagnostic alleles in both directions across the zone. The alleles are independent and not tightly linked to any of the pericentric rearrangements. Thus these 5 alleles are acting as markers of the background genome and reveal the relatively free movement of genes which are located outside the pericentric rearrangements.--It is proposed that the hybrid zone in Caledia captiva is unstable and is moving slowly in a westerly direction into the Torresian territory. This is due to the ability of the Moreton taxon to incorporate more readily into its genome those Torresian chromosomes or chromosome segments which increase the fitness of the Moreton taxon. On chromosomal criteria, the Torresian taxon does not share the same capacity.--It is suggested that, so long as the two taxa retain their ability to hybridise with subsequent asymmetrical introgression, the zone will continue to move westwards and eventually lead to the selective incorporation of the Torresian genome into the Moreton taxon. This will result in a polymorphic situation with clinal variation in chromosomal frequencies. The structure of the zone is dependent upon a fine balance between genomic reorganisation in recombinant genotypes and the relative dispersal capacities of the two hydridising taxa.

Animals↗
PubMed1979

A comparative trial of pivmecillinam and ampicillin in bacteriuria of pregnancy.

A comparative trial of pivmecillinam and ampicillin was performed on 100 women with bacteriuria of pregnancy. They received either 400 mg pivmecillinam four times daily or 500 mg ampicillin four times daily for seven days. Cure rates at two weeks were 88% in the pivmecillinam group and 85% in the ampicillin group. At six weeks the respective rates were 76% and 64%. Failure of therapy was not associated with the appearance of bacterial resistance in either treatment group. Side-effects, particularly vomiting and premature cessation of therapy, were significantly more frequent in the pivmecillinam group. No significant effects on liver function were found. In subsequent patients treated in a non-comparative manner with 200 mg pivmecillinam three times daily, the incidence of side effects was markedly reduced with no loss of efficacy.

Amdinocillin Pivoxil↗