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Biomedical subjects

J Christie

Publications and source records attributed to J Christie.

At least 55 records · Page 3Linked to original sources
PubMed1994

Cardiorespiratory and symptomatic variables during maximal and submaximal exercise in men with stable effort angina: a comparison of atenolol and celiprolol.

Celiprolol is a novel beta 1 selective adrenoreceptor blocker with partial beta 2 agonism and direct vasodilator activity. These ancillary properties may reduce symptomatic breathlessness and fatigue and modify respiration during exercise. To test this hypothesis 20 men with stable effort angina were enrolled in a double-blind crossover study to investigate the effects of atenolol 100 mg once daily (A) and celiprolol 400 mg once daily (C) on cardiorespiratory and symptomatic variables during maximal and submaximal exercise. Total exercise time on a modified Bruce protocol was similar on both treatments: C12.5 min, A 13.1 min. During steady state submaximal exercise at 60-75% (mean 68%) of maximum work capacity, minute ventilation (C33.81 min-1, A 33.51 min-1), oxygen uptake (C14.6 ml.kg-1.min-1, A15.1 ml.kg-1.min-1), respiratory exchange ratio (C 0.89, A 0.87), ratio of VE/VCO2 (C 33.6, A 33.4), ratio of VE/VO2 (C 2.34, A 2.72), Borg perceived exertion score (C 11.2, A 10.9) and visual analogue scores for breathlessness (C 29.5, A 25.9) and muscle fatigue (C 28.9, A 26.0) were all similar on both treatments. At maximal exercise capacity on the modified Bruce protocol, minute ventilation (C 58.31 min-1, A 60.41 min-1), oxygen uptake (C 21.3 ml.kg-1.min-1, A 21.7 ml.kg-1.min-1), respiratory exchange ratio (C 1.02, A.1.05), ratio VE/VCO2 (C 34.8, A 35.9), and ratio VE/VO2 (C 2.80, A 2.83) were also similar on both drugs. Over a 10 day period anginal attacks (C 10.1 +/- 10.4, A 5.4 +/- 5.9) and sublingual GTN use (C 5.9 +/- 10.3, A 4.4 +/- 9.8) were both more frequent on celiprolol).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1994

Pacemaker failure induced by radiotherapy.

It is well documented that radiation therapy can have significant transitory and permanent effects on the function of cardiac pacemakers. In this study 18 multiprogrammable pacemakers were tested to establish any pattern by which these pacemakers are affected. The results confirm previous predictions on how pacemakers are damaged. The damage could be divided essentially into three types: (1) temporary change to interference or safety mode pacing lasting for the duration of the irradiation only; (2) change to interference mode pacing--from which recovery may occur after reprogramming the pacemaker; and (3) severe damage; in this case the pacemaker stops generating pulses. Recovery from this may occur a long time after the end of the treatment, but this recovery is mostly incomplete and the pacemaker cannot be used reliably thereafter. Therefore it is essential that patients with implanted pacemakers undergoing radiation therapy, should be monitored closely during the course of the treatment and for a few weeks thereafter.

Electromagnetic Fields↗
PubMed1994

Echocardiography of transatrial embolism during cemented and uncemented hemiarthroplasty of the hip.

We performed transoesophageal echocardiography on 20 patients with femoral neck fractures randomly treated with an uncemented Austin-Moore or cemented Hastings hemiarthroplasty. Cemented arthroplasty caused greater and more prolonged embolic cascades than did uncemented arthroplasty. Some emboli were more than 3 cm in length. In some patients the cascades were associated with pulmonary hypertension, diminished oxygen tension and saturation, and the presence of fat and marrow in aspirates from the right atrium.

Arthroplasty↗
PubMed1993

The two-part proximal humeral fracture: a review of operative treatment using two techniques.

A review of 45 patients who have undergone surgery for two-part fractures of the proximal humerus (Neer Group III) is reported using two operative techniques, AO plating and intramedullary Rush pins. Good functional results were obtained using the former technique in seven out of eight of the patients under the age of 50 years who mainly sustained their original injury as a result of high-energy motor vehicle accidents. However, in the more common low-energy, osteoporotic fracture in the elderly population, results were unsatisfactory in 12 out of 14 cases where AO plating was used, usually as a result of fixation failure. The Rush pin technique produced more reliable results in this age group, with satisfactory functional scores being obtained in 16 out of 23 patients. It is suggested that the Rush pin technique is preferable to plate fixation in the more common osteoporotic insufficiency fracture in the elderly.

Adult↗
PubMed1993

Nonsteroidal antiinflammatory drugs, perioperative blood loss, and transfusion requirements in elective hip arthroplasty.

A study of 160 elective total hip arthroplasties revealed that those patients receiving nonsteroidal antiinflammatory drugs (NSAIDs) in the preoperative period had a significantly increased perioperative blood loss and transfusion requirement when compared with a control group receiving other forms of analgesia for their osteoarthritis. The results suggest that NSAIDs are implicated in increasing the operative blood loss in these patients. The range of increased blood loss varied from 1.57 to 2.08 times the blood loss in the control group, and this effect was seen when the operation was carried out under spinal as well as when under general anesthesia.

Aged↗
PubMed1993

Does the use of an assessment tool in the accident and emergency department improve the quality of care?

The aim of this study was to evaluate the effect of introducing a nursing record, using the SOAPE model, in the accident and emergency department. A working group was formed to design and implement a new record and evaluate its effect. A 6-month teaching programme was run to prepare staff. Quality of documentation was measured using the Phaneuf Audit Tool both before and after the implementation of the new record and the teaching sessions. The results were compared. It was concluded that, overall, the documentation showed significant improvement. Therefore, it could be assumed that there had been an improvement in the quality of care.

Documentation↗
PubMed1993

Early treatment with captopril after acute myocardial infarction.

OBJECTIVES: To determine the effects of early treatment with captopril on haemodynamic function, neuroendocrine biochemistry, left ventricular structure, clinical outcome, and exercise capacity over one year from acute myocardial infarction. DESIGN: Randomised, double blind, placebo controlled comparison of captopril and placebo. SETTING: Coronary care units and cardiology departments of two university teaching hospitals in Glasgow. PATIENTS: 99 haemodynamically stable patients with acute myocardial infarction, selected on clinical grounds as being at risk of late ventricular dilatation. INTERVENTION: Captopril or identical placebo started between six and 24 hours after start of symptoms and continued for 12 months. Target maintenance dose was 25 mg three times a day. MAIN OUTCOME MEASURES: (a) Acute haemodynamic effects of treatment; (b) neuroendocrine biochemistry from admission to two months; and (c) change in echocardiographic measures of left ventricular size, clinical outcome, and exercise capacity after 12 months of treatment with a separate analysis of the effects of one month of treatment withdrawal on left ventricular volumes. RESULTS: Captopril caused acute reductions in mean (SEM) pulmonary artery pressure (2.48 (0.69) mm Hg) and systemic vascular resistance (260 (103)) dyn.s.cm-5). Over the first 10 hours captopril reduced mean arterial pressure by 12.1 (2.4) mm Hg compared with 3.8 (1.9) mm Hg in the placebo group. No patient had to be withdrawn from the captopril group because of hypotension. From day 1 onwards systolic and diastolic arterial pressures in the captopril treated group were slightly but not significantly lower than on placebo. There was no difference in the incidence of ventricular or supraventricular arrhythmia with treatment. Captopril prevented the day 3 peak in angiotensin II that occurred in the placebo group (peak concentration (interquartile range): 10.1 (4.8-19.4) pg/ml v 16.8 (4.3-46.3) pg/ml)) but had no effect on atrial natriuretic factor, arginine vasopressin, or catecholamines. Plasma atrial natriuretic factor remained above normal in both groups at two months after infarction. After one year left ventricular volume indices had increased less on captopril than on placebo: left ventricular end systolic volume index 5.4 ml/m2 v 14.7 ml/m2 (95% confidence interval (95% CI) of difference -14.6 to -3.9; p = 0.0011); left ventricular end diastolic volume index 8.4 ml/m2 v 19.0 ml/m2 (95% CI of difference, -17.0 to -4.2; p = 0.0016). Withdrawal of captopril for one month did not affect ventricular volumes. There was no difference in exercise capacity. CONCLUSIONS: Captopril started between six and 24 hours after acute myocardial infarction is not associated with significant hypotension. It suppresses activation of the renin angiotensin system but has no effect on plasma concentrations of other neurohormones. Atrial natriuretic factor remains raised at two months after myocardial infarction. Captopril significantly decreases left ventricular dilatation. This effect is not lost after one month of treatment withdrawal and is thus due to an alteration of left ventricular structure and not to a short lived haemodynamic action of captopril. Long-term treatment with captopril does not result in improved aerobic exercise capacity after acute myocardial infarction.

Adult↗
PubMed1993

Open adult femoral shaft fracture treated by early intramedullary nailing.

In two hospitals, 115 consecutive open femoral shaft fractures were treated by meticulous wound excision and early locked (97) or unlocked (18) intramedullary nailing. All the fractures united; union was delayed in four, three of which required bone grafting. The average range of knee flexion at follow-up was 134 degrees (60 to 148). Five patients had a final range of less than 120 degrees, but three of these improved after manipulation under general anaesthesia. Three patients developed staphylococcal infections and required further surgical treatment. All eventually healed.

Adolescent↗
PubMed1993

The detection of fat embolism by transoesophageal echocardiography during reamed intramedullary nailing. A study of 24 patients with femoral and tibial fractures.

We performed transoesophageal echocardiography on 24 patients during reamed intramedullary nailing of 17 tibial and seven femoral fractures. In 14 patients there was only minimal evidence of emboli passing through the heart, but in six copious showers of small emboli (< 10 mm maximum dimension) were observed. In four other patients, there were also multiple large emboli (> 10 mm maximum dimension). Three of these patients developed fat embolism syndrome postoperatively and one died. Earlier nailing was associated with smaller quantities of emboli.

Adolescent↗
PubMed1993

The relationship of scrotal circumference to histological testicular parameters and sperm reserves.

Bonsmara bulls (n = 10) were castrated at 410 d of age. Their scrotal circumference varied between 31.0 and 42.0 cm (mean: 36.0; SD: 1.7). Bulls were divided into above average (> 36 cm) and below average (< 36 cm) groups. Significant correlations were reported for scrotal circumference with seminiferous tubules diameter (r = 0.84), percentage vacuolisation (r = -0.74) and epididymal sperm reserves (r = 0.79). A significant linear relationship (Y = 3.9 X = 105.3) was reported between scrotal circumference and epididymal sperm reserves.

Animals↗
PubMed1993

Spatial orientation and posture during and following weightlessness: human experiments on Spacelab Life Sciences 1.

The 4 payload crew members of the Spacelab Life Sciences 9-day space flight in 1991 were subjected to limited vestibular testing in flight as well as pre and post flight. Major differences in individual "perceptual style" appeared in their reaction to the visual-vestibular stimuli in the rotating dome experiment, and especially in the extent to which nondirectional tactile cues served to anchor the subjective vertical and body postural reactions. The ability of subjects to point to remembered target positions was degraded in space, which produced a tendency to point low in some subjects in flight. The eye movements and subjective response to sudden stops and head pitching following continuous spinning (dumping) were measured both in space and on the ground. Although subjective duration of inflight rotation for the dumping tests was shorter than that for the preflight tests, the postrotatory nystagmus, with or without head pitch, was lengthened in time constant relative to preflight. Ground tests, in addition to the flight experiments, investigated the changes following weightlessness in subjective and oculomotor reactions to whole body tilt, the ability to balance with eyes open and closed; leg muscles strength and stamina as related to posture; visual field dependence; and the perceptual and oculomotor reactions to horizontal linear acceleration. Several of these tests, as well as post-flight measures of motion sickness susceptibility, revealed subtle evidence of neurovestibular alterations that lasted a week or more following the 10-day orbital exposure.

Adaptation, Physiological↗
PubMed1992

Enhancement of incisional wound healing and neovascularization in normal rats by thrombin and synthetic thrombin receptor-activating peptides.

To better define thrombin-receptor interactions, we synthesized human thrombin peptides and identified binding-domain peptides that bind thrombin receptors and activate mitogenic signals (Glenn, K.C., G.H. Frost, J.S. Bergmann, and D.H. Carney. 1988. Pept. Res. 1:65-73). Treatment of full dermal dorsal incisions with a single topical application of thrombin receptor-activating peptide (TRAP-508) or human alpha-thrombin in saline enhances 7-d incisional breaking strength in normal rats up to 82% or 55% over saline-treated controls, respectively. Control wounds require approximately 11.5 d to achieve breaking strength equivalent to TRAP-treated wounds at day 7. Thus, a single application of TRAP accelerates healing, shifting the time course forward by up to 4.5 d. Histological comparisons at day 7 show more type I collagen, less evidence of prolonged inflammation, and an increase in number and maturity of capillaries in TRAP- and thrombin-treated incisions. Angiograms also show 50-65% more functional vascularization going across thrombin- and TRAP-treated surgical incisions. Thus, alpha-thrombin and thrombin peptides, such as those released following injury, appear to initiate or enhance signals required for neovascularization and wound healing. The ability to accelerate normal wound healing events with synthetic peptides representing receptor binding domains of human thrombin may offer new options for management of wound healing in man.

Amino Acid Sequence↗
PubMed1992

Sleep shift dissociates the nocturnal peaks of parathyroid hormone (1-84), nephrogenous cyclic adenosine monophosphate, and prolactin in normal men.

The secretion of PTH(1-84) and PRL over a 24-h period in normal subjects has been shown to be highly correlated, with changes in PRL occurring approximately 2 h after those in PTH(1-84). It has been postulated that there may be neuroendocrine control common to PTH(1-84) and PRL. As the secretion of PRL is known to be strongly influenced by sleep we investigated the effect of a 7-h acute sleep shift on the nocturnal secretion of PTH(1-84), PRL, and nephrogenous cAMP, a marker of PTH(1-84) bioactivity. Six normal male subjects were studied on two occasions (study A sleep, 0100-0800 h; study B, 0800-1400 h) with samples withdrawn at 30-min intervals. Sleep shift produced the expected shift in PRL secretion to new time of sleep. The overall timing of the PTH(1-84) nocturnal peak (0200-0600 h) was not altered by sleep shift. However, the start of the rise in PTH(1-84) (0200-0300 h) was blunted (P less than 0.05), and the peak of nephrogenous cAMP, coincident with the nocturnal rise in PTH(1-84) in study A, was markedly attenuated (P less than 0.01). Thus whereas the results of this study argue against a direct neuroendocrine link between PTH(1-84) and PRL, it is postulated that sleep shift disrupts a high degree of temporal organization which, under normal conditions, may allow concerted metabolic effects between PTH(1-84) and other hormones over a 24-h period.

Adult↗
PubMed1991

Effects of early captopril administration on infarct expansion, left ventricular remodeling and exercise capacity after acute myocardial infarction.

In a double-blind study, 99 patients (82 men, age range 40 to 75 years) with acute myocardial infarction (AMI) were randomly assigned to receive captopril or placebo. Treatment began within 24 hours of admission. Serial echocardiographic measurements of endocardial segment lengths and left ventricular (LV) volumes, and ejection fractions were obtained. The 2 groups were matched at baseline except for an excess of previous AMI in the placebo group (13 of 50 vs 2 of 49 patients, p = 0.002). The increase in anterior segment length, from baseline to 2 months, was significantly less in the captopril than in the placebo group (2.8 +/- 1.6 vs 10.4 +/- 2.4mm, 95% confidence interval [CI] -13.5 to -1.7, p = 0.01). The increase in posterior segment length was also less in the captopril group, but the difference was not significant (3.2 +/- 1.2 vs 7.0 +/- 1.8mm, 95% CI -8.0 to 0.5, p = 0.08). Fewer patients in the captopril group demonstrated increases in segment length greater than 2 standard deviations of the measurement error (14 of 70 [20%] vs 29 of 72 [40%] patients, p = 0.009). In patients with anterior AMI, the infarct-containing anterior segment length increased by 4.5 +/- 2.3 mm in the captopril versus 12.4 +/- 3.1 mm in the placebo group (95% CI -15.7 to -0.2, p = 0.046), and fewer patients in the captopril group demonstrated infarct expansion (6 of 20 [30%] vs 13 of 21 [62%] patients, p = 0.04).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗