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Biomedical subjects

S Robertson

Publications and source records attributed to S Robertson.

At least 91 records · Page 5Linked to original sources
PubMed1996

Isoetharine versus albuterol for acute asthma: greater immediate effect, but more side effects.

PURPOSE: To compare the magnitudes of the immediate effects of the nebulized beta-agonists isoetharine and albuterol in the treatment of acute severe asthma. PATIENTS AND METHODS: Fifty-one adults presenting with severe asthma exacerbations (forced expiratory volumes in the first second of exhalation [FEV1] <40% of predicted) to the emergency department were randomized (double-blind) to receive hourly inhaled nebulization treatment with either isoetharine (5 mg) or albuterol (2.5 mg). The FEV1 was measured immediately before and after each nebulized treatment. Any side effects were recorded. RESULTS: Immediately after the first nebulized treatment, the isoetharine group improved its mean FEV1 (+/-SEM) by a significantly greater amount than did the albuterol group: 60% +/- 11% versus 39% +/- 5%, respectively (P <0.05). One hour later the mean FEV1 were equivalent. This pattern repeated itself after the second hourly treatment. The two groups did not differ in any outcome parameters (FEV1 at discharge, number of nebulized treatments required, the number of inpatient admissions, number of clinical relapses after discharge). More patients treated with isoetharine had side effects (36% versus 4% for albuterol, P <0.01), 1 of whom required discontinuation from the study. CONCLUSIONS: Both medications were equally effective in alleviating bronchospasm. The immediate effect of isoetharine was significantly greater, but equalized that of albuterol within an hour after treatment. There were more side effects with isoetharine.

Acute Disease↗
PubMed1996

Specificity of learning and dynamic balance.

Contrary to a strict specificity of learning position, Robertson, Collins, Elliott, and Starkes (1994) have reported that the balance beam performance of expert gymnasts is less affected by the withdrawal of vision than is the performance of novice gymnasts. In this study, we employed a training paradigm in order to exercise complete control over the sensory conditions under which a dynamic balance beam task was acquired. Novice participants were trained either with or without vision to walk across a balance beam as quickly as possible and later tested in the other vision condition. Although participants improved more in the condition in which they trained, practice in one sensory condition did not negatively affect performance in a different sensory circumstance. The finding that vision was still extremely important after 5 days of practice is problematic for models of motor learning that propose a progression with learning from closed-loop to open-loop control.

Adult↗
PubMed1996

A broader phenotype of autism: the clinical spectrum in twins.

The diagnostic boundaries of the behavioural phenotype for autism were examined in 28 MZ pairs and 20 DZ same-sex twin pairs, where one or both twins had autism. In the non-autistic cotwin (i.e. in twin pairs discordant for autism) it was common to find language impairments in childhood and social deficits persisting into adulthood. Concordance for this broader phenotype was much greater in MZ pairs than DZ pairs, indicating a strong genetic component. Behavioural and cognitive manifestations of autism were compared both within and between MZ twin pairs. The variation was as great within MZ twin pairs as between pairs, suggesting that it does not index genetic heterogeneity (although aetiological heterogeneity probably exists). Current diagnostic practices need re-evaluation.

Activities of Daily Living↗
PubMed1996

Evaluation of humoral and cell-mediated inducible immunity to Haemophilus ducreyi in an animal model of chancroid.

To study the mechanisms of inducible immunity to Haemophilus ducreyi infection in the temperature-dependent rabbit model of chancroid, we conducted passive immunization experiments and characterized the inflammatory infiltrate of chancroidal lesions. Polyclonal immunoglobulin G was purified from immune sera raised against H. ducreyi 35000 whole-cell lysate or a pilus preparation and from naive control rabbits. Rabbits were passively immunized with 24 or 48 mg of purified polyclonal immunoglobulin G intravenously, followed 24 h after infusion by homologous titered infectious challenge. Despite titratable antibody, no significant difference in infection or disease was observed. We then evaluated the immunohistology of lesions produced by homologous-strain challenge in sham-immunized rabbits and those protectively vaccinated by pilus preparation immunization. Immunohistochemical stains for CD5 and CD4 T-lymphocyte markers were performed on lesion sections 4, 10, 15, and 21 days from infection. Lesions of pilus preparation vaccinees compared with those of controls had earlier infiltration with significantly more T lymphocytes (CD5+) and with a greater proportion of CD4+ T lymphocytes at day 4 (33% +/- 55% versus 9.7% +/- 2%; P = 0.002), corroborating earlier sterilization (5.0 +/- 2 versus 13.7 +/- 0.71 days; P < 0.001) and lesion resolution. Intraepithelial challenge of pilus-vaccinated rabbits with 100 micrograms of the pilus preparation alone produced indurated lesions within 48 h with lymphoid and plasmacytoid infiltration, edema, and extravasation of erythrocytes. We conclude that passive immunization may not confer a vaccine effect in this model and that active vaccination with a pilus preparation induces a delayed-type hypersensitivity skin test response and confers protection through cell-mediated immunity seen as an amplified lymphocytic infiltrate and accelerated maturation of the T-lymphocyte response.

Animals↗
PubMed1996

An exploration of the quality of peer review group activities within Australasia.

OBJECTIVE: To describe a two-phase study of the structure of Australasian psychiatrist peer review groups. METHOD (Phase one): Initially, information was sought from chairs/coordinators of psychiatrist peer review groups regarding the nature and organisation of their group. RESULTS (Phase one): One hundred and three questionnaires were returned describing a number of models of peer review. Three principal models were identified: a teaching hospital model, a private practice model, and a private institution model. METHOD (Phase two): The second-phase questionnaire sought information on the quality of the review, using six proposed standards developed by the Quality Assurance Committee of the Royal Australian and New Zealand College of Psychiatrists. RESULTS (Phase two): Many groups indicated that four of the proposed standards (those relating to documentation, having clear goals, reviewing actual clinical cases, and rigorous protection of confidentiality) were either already being followed or would be relatively easy to implement. The remaining two proposed standards (including structure, process and outcome dimensions of health care in the case discussion, and the use of explicit criteria) presented more difficulty. CONCLUSION: The application of such standards to peer review group meetings should assist groups to provide a forum for presentation and evaluation of clinical work where participants know they will be challenged in an environment which is both supportive and educational.

Attitude of Health Personnel↗
PubMed1996

To whom do you refer? A referrer satisfaction study.

OBJECTIVE: To report the development of a referrer satisfaction measure. METHOD: Urban and rural general practitioners, physicians, neurologists, as well as obstetricians and gynaecologists rated 36 items in terms of their judged importance to the respondent's satisfaction with a psychiatric service. Responses of the whole sample and component practitioner sub-groups were ranked. RESULTS: We established a high level of agreement across the several subgroups suggesting that we had identified general rather than idiosyncratic variables contributing to referrer satisfaction. Referrers prioritised as most important the immediacy of initial appointment, the psychiatrist reporting at the beginning and end of any treatment course, and ready verbal communication between the referrer and the psychiatrist. Items accorded low priority were the psychiatrist's billing arrangements, the psychiatrist being 'perfect' (in either having a high 'cure' rate or making a definitive diagnosis initially), or the psychiatrist taking complete responsibility for difficult patients. A principal components analysis identified four factors underpinning the item set, and we again established that scores on these factors were not influenced by the particular referrer sub-group. CONCLUSIONS: Such findings suggest that only minor modifications would need to be made to the item set in developing a referrer satisfaction measure for quality assurance activities.

Family Practice↗
PubMed1996

The development of a patient satisfaction measure for psychiatric outpatients.

OBJECTIVE: To describe the first stage of development of a patient satisfaction form designed for psychiatric outpatients. METHOD: An initial 62-item questionnaire was completed by 172 patients, who were asked to assess the importance of a number of practice and practitioner features in contributing to their satisfaction. RESULTS: Mean scores prioritized the psychiatrist respecting the rights of the patient; appointment and billing arrangements were of intermediate importance, while amenity issues were rated as unimportant. When rankings across the several practices were examined, very high levels of agreement were demonstrated, supporting the likely validity of the overall rankings. Four underlying domains were identified by factor analysis, the principal one being defined by respect for confidentiality, by support and adequate communication. The three remaining factors were contributed to more by practice (e.g. billing arrangements, amenities) than by practitioner features. CONCLUSION: We consider how a refined and modified version of the measure might be developed for use by both individual practitioners and group practices, as well as being used as a formal QA component activity.

Australia↗
PubMed1995

Pharmacokinetics and presystemic gut metabolism of methyldopa in healthy human subjects.

This study examined the pharmacokinetics and metabolism of methyldopa after giving single 250-mg oral and intravenous doses to 16 healthy human volunteers. A 48-hour washout period was allowed between oral and intravenous treatments. Blood and urine samples were collected; methyldopa was assayed in blood and urine, and its metabolites (methyldopa sulfate, alpha-methyldopamine, and alpha-methyldopamine sulfate) were assayed in urine. Pharmacokinetic parameters were recorded as follows: half-life was 2.0 +/- 0.7 hours; total body and renal clearance were 268 +/- 72 and 107 +/- 35 mL/min, respectively; and volume of distribution at steady-state was 33 +/- 11 L. The absolute bioavailability of the drug was 42 +/- 16%. The measurable metabolites in urine after oral and intravenous administration accounted for 27% and 17% of the dose, respectively. Methyldopa sulfate was the most abundant metabolite recorded; its quantity was higher after oral than after intravenous administration, 20.1 +/- 5.7% versus 6.7 +/- 5.3% of the dose (P < .05), suggesting significant presystemic gut metabolism. First-pass gut metabolism for methyldopa was estimated to be 17.6 +/- 6.9% of the dose given.

Administration, Oral↗
PubMed1995

Methyldopa kinetics before and after ingestion of methyldopa for eight weeks.

Methyldopa urine and plasma levels and urine metabolite levels were assessed following intravenous (IV) and oral (PO) methyldopa before, and after ingestion of methyldopa (500 mg) daily for eight weeks. There was no increase in (estimated) methyldopa absorption (8.4%) or renal clearance (PO 13.9%, IV 2.33%) after the eight weeks of methyldopa ingestion. However, the initial methyldopa absorption and renal clearance values in this study were higher than that in previous studies. There was an inverse relation between the initial methyldopa absorption and the change in absorption (r - 0.605) and between the initial methyldopa renal clearance and the change in renal clearance (PO r -0.874, IV r -0.891). Overall, this study did not confirm our previous studies showing induction of methyldopa absorption and renal clearance, possibly due to prior up regulation of transporter function. Consistent with methyldopa inducing drug transporters, those with low initial absorption and renal clearance values had the greatest increases.

Absorption↗
PubMed1995

Routine prostate biopsies following radiotherapy for prostate cancer: results for 226 patients.

OBJECTIVES: To determine the time course of histologic resolution of prostate cancer following radiotherapy (RT) and to correlate biopsy results with clinical outcome. METHODS: Since July 1990, all patients treated with radical external beam RT for prostate cancer at the General Division of the Ottawa Regional Cancer Centre have had systematic transrectal ultrasound (TRUS) and TRUS-guided biopsies beginning 12 months after RT and then every 6 months until negative or until clinical failure. Thus, 226 patients have had 375 TRUS with four to seven specimens per examination. Stage distribution was T1b: 32, T1c: 11, T2a: 45, T2b: 82, T3: 50, and T4: 6. Median follow-up was 33 months. RESULTS: Biopsy results were negative in 69.5% of patients by 30 months of follow-up. Thirty-two (14%) had local failure (T1b: 12.5%, T1c: 0%, T2a: 11%, T2b: 15%, T3: 18%, T4: 33%). Seven (3%) had chemical failure, and 47 (21%) had biopsy-only failure. Median follow-up for the biopsy-only failure group is only 19.5 months and mean prostate-specific antigen (PSA) is 1.0 ng/mL. Thirty-nine patients, initially with biopsy-only failure, have converted to negative biopsies at a median of 26 months. Nadir PSA for patients with local failure was 3.9 ng/mL at 14 months versus 0.7 ng/mL at 23 months for those without failure. Patients with late conversion to negative biopsy results had a later nadir PSA of 1.3 ng/mL at 27.3 months. CONCLUSIONS: Routine prostate biopsy specimens after RT in an unselected population show tumor clearance that is in agreement with long-term clinical follow-up, although tumor may take more than 30 months to resolve. Nadir PSA can be used to predict outcome.

Aged↗
PubMed1995

Inducible immunity with a pilus preparation booster vaccination in an animal model of Haemophilus ducreyi infection and disease.

Using the temperature-dependent rabbit model of Haemophilus ducreyi infection as a quantitative virulence assay, we tested the abilities of two bacterial antigen preparations to induce protection against subsequent infection and disease. Lipooligosaccharide (LOS) and a pilus preparation were purified from H. ducreyi 35000 and were used in a booster immunization procedure. The serologic response to each immunogen was monitored by enzyme immunoassay. H. ducreyi virulence was assayed by intraepithelial inoculation and subsequent measurement of disease for homologous strain 35000 or clinical isolate RO-34. LOS and the pilus preparation induced humoral responses. The kinetics of the LOS antibody response suggest a type 1 T-independent response, whereas the pilus preparation induced an anamnestic response. An inoculum of 10(5) CFU of H. ducreyi 35000 or RO-34 consistently produced ulcerative chancroidal lesions in naive rabbit controls. Immunization with LOS did not modify the virulence of H. ducreyi 35000. Immunization with the strain 35000 pilus preparation significantly reduced the severity of disease and the duration of infection and disease compared with controls, with either homologous or heterologous strain infection. The histology of lesions from pilus preparation-vaccinated rabbits compared with that of lesions from controls revealed accelerated lymphoid cell recruitment, more prominent plasma cell infiltrate, and reduction in subsequent histiocytic infiltration. We conclude that both LOS and the pilus preparation are immunogenic and that the latter induces homologous and heterologous strain protection in this animal model of infection and disease.

Animals↗
PubMed1995

Characterization of a neurologic disease induced by a polytropic murine retrovirus: evidence for differential targeting of ecotropic and polytropic viruses in the brain.

A variety of ecotropic murine leukemia viruses cause neurodegenerative disease. We describe here the clinical and histopathological features of a neurologic disease induced by a polytropic murine leukemia virus, FMCF98. Clinical disease was dominated by hyperexcitability and ataxia, and the histopathology was characterized primarily by astrocytosis and astrocytic degeneration. The viral envelope gene harbored the determinants of neurovirulence, since the chimeric virus Fr98E, which contained the envelope gene of FMCF98 on a background of the nonneurovirulent virus FB29, caused a similar disease. The disease caused by Fr98E differed from that induced by the coisogenic neurovirulent ecotropic virus FrCasE in clinical presentation, histopathology, and distribution of virus in the central nervous system. Since Fr98E contains a polytropic envelope gene and FrCasE contains an ecotropic envelope gene, these phenotypic differences appeared to be determined by envelope sequences and may reflect differences in virus receptor usage in the central nervous system.

3T3 Cells↗
PubMed1995

The use of aspirin and opiates by Dumfries and Galloway general practitioners in the management of acute myocardial infarction.

In March 1994 a study in the British Medical Journal indicated a low rate of administration of aspirin and opiates by general practitioners in cases of suspected myocardial infarction. A retrospective analysis was made of 120 consecutive admissions to the medical intensive care unit of Dumfries and Galloway Royal Infirmary, by general practitioners, with a primary diagnosis of acute myocardial infarction. Of these 120 cases, 24% were given aspirin by their G.P. prior to admission and 64% were given opiate (IV or IM). Thirty-three percent were already on regular aspirin and of these 18% received further aspirin prior to admission. These figures were considerably better than those previously quoted and they showed that prior regular aspirin therapy did influence the GPs' decision on further administration of aspirin in the acute event. A questionnaire sent to all GPs in Dumfries and Galloway revealed that 100% carried aspirin in their medical bags, 62% claimed to give aspirin to patients with suspected MI, 95% used a British Heart Foundation approved dose of aspirin and 83.3% administered the aspirin using one of the approved methods.

Aspirin↗