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Biomedical subjects

J Thornton

Publications and source records attributed to J Thornton.

At least 19 recordsLinked to original sources
PubMed1992

Effect of using protocols on medical care: randomised trial of three methods of taking an antenatal history.

OBJECTIVE: To compare the effectiveness of three methods of taking an antenatal history on the quality of obstetric care. DESIGN: Randomised controlled trial. SETTING: Antenatal clinic of St James's University Hospital, Leeds. SUBJECTS: 2424 women attending the hospital for the first (booking) visit. INTERVENTIONS: Histories were taken by midwives using an unstructured paper questionnaire, a structured paper questionnaire (incorporating a checklist), or an interactive computerised questionnaire (incorporating 101 clinical reminders). MAIN OUTCOME MEASURES: The number of clinical responses to factors arising from the antenatal booking history according to method of taking the history. Actions were categorised as medical and surgical, obstetric, personal, current symptoms and treatment, related to maternal age, and related to two common actions (cervical smear testing and dental hygiene) and were weighted for clinical importance by 10 obstetricians. RESULTS: Overall the unstructured questionnaire generated 1063 actions, the structured questionnaire 1146, and the computerised questionnaire 1122. The clinical importance of these actions was lowest for the unstructured questionnaire (overall total value score 1987 v 2182 and 2110 for the structured and computerised questionnaires respectively). The structured questionnaire was better than the computerised questionnaire in the medical and surgical (total value score 191 v 184), obstetric (275 v 241), and personal (430 v 360) categories but inferior in the current symptoms category (179 v 191). CONCLUSION: Structured questionnaires (computerised or paper) provide more and better information, and their use improves clinical response to risk factors. Computerised systems offer no further advantage in antenatal clinics.

Clinical Protocols↗
PubMed1992

Adenosine is an endogenous protectant against stunning during repetitive ischemic episodes in the heart.

To investigate whether adenosine receptor blockade alters the response to serial coronary occlusions in the rabbit heart, we measured changes in segment length with ultrasonic dimension gauges placed in the field of a coronary branch. The coronary branch was subjected to four 5-minute occlusions, each separated by 10 minutes of reperfusion. In control hearts, the percentage of segment shortening fell from 15.7% to 9.3% after release of the first occlusion with no further deterioration after each of the subsequent three occlusions. In hearts in which adenosine receptors were blocked with PD 115,199, a potent blocker of both A1 and A2 receptors, segment shortening again recovered to about two thirds of the preischemic value during the reperfusion period after the first occlusion. Each subsequent occlusion, however, resulted in a further deterioration of function to the extent that shortening was less than 20% of the preischemic value during reperfusion after the fourth occlusion. Therefore the first occlusion of a series of four occlusions, while mildly stunning the heart, also preconditions the myocardium against further stunning by subsequent occlusions. Because that protection was when adenosine receptors were blocked, adenosine must play an important role in the mediation of this protective effect.

Adenosine↗
PubMed1992

Body-fat measurement in patients with acquired immunodeficiency syndrome: which method should be used?

Malnutrition is common in patients with acquired immunodeficiency syndrome (AIDS), which distorts the chemical contents in the fat-free mass (FFM) and alters the assumptions underlying the traditional methods for calculating body-fat content so that such measurements may not be accurate. In vivo neutron-activation analysis (IVNA) measures FFM independently of the traditional assumptions, thereby providing more accurate measurements of body fat. We compared seven methods for measuring body fat in 18 male patients with AIDS: IVNA, total body water (TBW by 3H2O dilution), total body potassium (TBK by 40K counting), dual-photon absorptiometry (DPA), bioelectrical impedance analysis (BIA), and two well-calibrated anthropometric methods. FatTBW and fatDPA were not significantly different from fatIVNA. FatTBW gave the highest correlation with fatIVNA and the smallest SEE of +/- 1.8% (1.1 kg). The traditional and widely available TBW and the newer DPA method provide reliable estimates of fatIVNA in patients with AIDS.

Absorptiometry, Photon↗
PubMed1992

Protection from reperfusion injury by preconditioning hearts does not involve increased antioxidant defenses.

Preconditioning the heart with 5 min of ischemia renders the heart very resistant to infarction from subsequent ischemia by an unknown mechanism. We investigated whether the protective effect of preconditioning might be related to an increase in rabbit heart antioxidant defenses. The antioxidant activities of catalase, glutathione peroxidase, Mn superoxide dismutase, Cu,Zn superoxide dismutase, glucose-6-phosphate dehydrogenase, glutathione reductase, and total glutathione were measured in ischemic and normal regions from both control and preconditioned rabbit hearts. All hearts experienced 30 min regional ischemia and 5 min reperfusion. None of the antioxidant enzymes changed in activity when comparing nonischemic and postischemic zones in either nonpreconditioned or preconditioned hearts. Total glutathione, however, was reduced in reperfused zones and showed better preservation in preconditioned hearts. To determine whether this preservation resulted from a higher value at the onset of reperfusion or slower washout during reperfusion, we analyzed a second group of nonreperfused hearts after 30 min ischemia. The hearts had normal glutathione content in both ischemic and nonischemic zones of either preconditioned or control hearts. The most likely explanation is that preconditioned hearts experienced less washout of glutathione simply because they were less injured. We therefore conclude that enhancement of antioxidant defenses is not the mechanism of preconditioning.

Adaptation, Physiological↗
PubMed1992

Needs of well siblings of persons with schizophrenia.

The practical concerns of well siblings of persons with schizophrenia were examined in a descriptive study that included a needs assessment survey and a workshop designed to increase well siblings' knowledge about schizophrenia. A questionnaire focusing on needs for information, support, and practical skills was completed by 88 well siblings and 19 of their spouses. The results indicated a desire for more specific information about schizophrenia, particularly prognosis, and difficulties in communicating and problem solving with siblings with schizophrenia. Although respondents to the questionnaire were neutral about the need for support from other well siblings, participants at the workshop indicated that they found the opportunity to meet and share experiences with other well siblings to be the workshop's strongest feature. The study indicates that well siblings of persons with schizophrenia have specific needs that may differ from those of other family members.

Activities of Daily Living↗
PubMed1992

A prospective randomized trial of laparoscopic versus open appendectomy.

BACKGROUND: Laparoscopic appendectomy is feasible, but whether it confers any advantage to patients with acute appendicitis is not known. We performed a randomized controlled trial to compare results of laparoscopic and open appendectomy in patients with signs and symptoms suggesting acute appendicitis who were seen by one surgical team. METHODS: Sixty-two consecutive patients were randomized, 30 to laparoscopy and 32 to a classical open appendectomy. Postoperative recovery, complications, and return to normal activities were compared in the two groups. RESULTS: The laparoscopy group were discharged earlier (2.5 vs 3.8 days, p less than 0.01). Postoperative complications were more frequent after open appendectomy. Follow-up showed less pain, shorter bed stay at home, and faster return to work and sport after laparoscopic appendectomy. CONCLUSIONS: This prospective randomized study shows that laparoscopic appendectomy is superior to open appendectomy in terms of hospital stay, postoperative complications, and return to normal activities and is recommended as the approach of choice in the management of acute appendicitis.

Adult↗
PubMed1979

Decrease in vital capacity in PCB-exposed workers in a capacitor manufacturing facility.

Pulmonary function was evaluated in 243 workers exposed to PCB in the manufacture of capacitors. Mean employment was greater than 15 years. Thirty-four of the workers (14%) were found to have a reduced Forced Vital Capacity (FVC less than 80% of Morris' predicted). Of the 34 with reduced FVC, 27 (80%) demonstrated a restrictive pattern of impairment (FEV1/FVC greater than 0.7). Only one of these 27 workers had an abnormal chest roentgenogram (greater than or equal to 1/0 by ILO UC Classification of Radiographs of Pneumoconioses). These findings are of interest in view of recent experimental data indicating the accumulation of PCBs and PCB metabolites in lung tissue (Brandt and Jansson). Restrictive spirometric impairment with no radiographic change is unusual in occupational exposure.

Adult↗
PubMed1979

Visual evoked potentials and the visuogram in multiple sclerosis.

Visual evoked potential (VEP) latency to a sinusoidal grating pattern was measured in each eye of 103 patients with multiple sclerosis (MS) and compared with results in a control group of 56 patients hospitalized for other neurological conditions. Of the 50 patients classified as having definite MS, 90% showed prolonged latency (over 131 msec) in one or both eyes. In each eye of 24 of the MS patients, psychophysical measurement of the detectability of grating patterns was obtained. This test was abnormal in 11 of 13 patients with definite MS, 3 of 4 with probable MS, and 5 of 7 with possible MS. There was no concordance between prolonged VEP latency and visual impairment as revealed by the psychophysical test. Apparently pathways determining VEP latency and spatial contrast detection may be unequally affected in MS.

Evoked Potentials↗
PubMed1978

Current status of skin substitutes.

In the current state of the art, viable human allograft is the best skin prosthesis available, but it leaves much to be desired. Characteristics of skin substitutes can be defined and measured, resulting in the rational approach to design and testing of synthetic skin substitutes. Thin silicone polymer and modified plastic membranes, collagen films, and adherent methacrylate polymer applied by a spray technique (Hydron) are the most promising materials at present.

Adhesiveness↗
PubMed1977

Evaluation of a psychiatric clerkship by videotape.

The authors used a videotape-based objective examination ingeneral psychiatry to assess the clinical competence of medical students who had completed their third-year clerkship. The test has been shown to be a reliable, valid measure of clinical competence. Subjective faculty grading related positively to test scores. Students on one ward had significantly lower overall test scores, with particularly low scores on clinical judgement questions. However, faculty grades for these students were not significantly different. This suggests that the faculty was unable to assess the relative efficacy of its own teaching. The test can provide objective assessment of student clinical competence and is a means of program evaluation.

Clinical Competence↗