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Biomedical subjects

S Brant

Publications and source records attributed to S Brant.

At least 19 recordsLinked to original sources
PubMed2006

Transition probabilities in 134Pr: a test for chirality in nuclear systems.

Exited states in 134Pr were populated in the fusion-evaporation reaction 119Sn(19F,4n)134Pr. Recoil distance Doppler-shift and Doppler-shift attenuation measurements using the Euroball spectrometer, in conjunction with the inner Bismuth Germanate ball and the Cologne plunger, were performed at beam energies of 87 MeV and 83 MeV, respectively. Reduced transition probabilities in 134Pr are compared to the predictions of the two quasiparticle + triaxial rotor and interacting boson fermion-fermion models. The experimental results do not support the presence of static chirality in 134Pr underlying the importance of shape fluctuations. Only within a dynamical context the presence of intrinsic chirality in 134Pr can be supported.

Journal Article↗
PubMed2001

Importance of rate control or rate regulation for improving exercise capacity and quality of life in patients with permanent atrial fibrillation and normal left ventricular function: a randomised controlled study.

OBJECTIVE: To determine the importance of rhythm regulation or rate control in patients with permanent atrial fibrillation (AF) and normal left ventricular function. PATIENTS AND INTERVENTIONS: Thirty six patients with a mixed fast and slow ventricular response rate to their AF were randomised to either His bundle ablation (HBA) and VVIR pacemaker (HBA group) or VVI pacemaker and atrioventricular modifying drugs (Med group). Outcomes assessed at one, three, six, and 12 months included exercise duration and quality of life. RESULTS: Exercise duration significantly improved from baseline in both groups. There was no difference in outcome between the groups (Med +40% v HBA +20%, p = NS). The heart rate profile on exercise was similarly slowed in both groups compared to baseline. Quality of life significantly improved in both treatment arms for the modified Karolinska questionnaire (KQ) (Med +50% v HBA +50%, p = NS) and the Nottingham health profile (NHP) (Med +40% v HBA +20%, p = NS). However, for the individual symptom scores of each questionnaire more were improved in the Med group (KQ-Med 6 improved v HBA 4, NHP-Med 3 v HBA 1). Left ventricular function was equally preserved by both treatments during follow up. CONCLUSION: In these patients control of ventricular response rate with either HBA + VVIR pacemaker or atrioventricular modifying drugs + VVI pacemaker will lead to a significant improvement in exercise duration and quality of life. Rhythm regulation by HBA did not confer additional benefit, suggesting rate control alone is necessary for the successful symptomatic treatment of these patients in permanent AF.

Aged↗
PubMed2000

Initial United Kingdom experience with the use of permanent, biventricular pacemakers: implantation procedure and technical considerations.

AIMS: To describe the institution of a biventricular pacing programme with particular reference to the implantation procedure and new technological considerations. METHODS AND RESULTS: Analysis of outcomes of a consecutive series of 54 patients undergoing attempted biventricular pacemaker implantation between February 1998 and April 1999. Successful implantation was achieved in 49 of the 54 patients (91%). Five patients required lead repositioning after initial successful implantation. Left ventricular lead pacing thresholds were found to be satisfactory and stable in the long term, with pacing thresholds of 1.3 V, 1.9 V and 1.6 V at implantation, 1 and 3 months, respectively. Left-sided lead function was not dependent on lead position within the tributaries of the coronary sinus. The implantation procedure was found to be safe, although one patient died during long-term follow-up. CONCLUSION: With appropriate previous experience in complex and coronary sinus pacing and with access to up-to-date pacemaker and lead technology, a biventricular pacemaker implantation service can be instituted with good medium-term results.

Adult↗
PubMed2000

Does resuscitation training affect outcome from cardiac arrest?

It is established that basic life support (BLS) is performed inadequately by both nursing and medical staff and that the ability to retain these skills, once trained, is low. In addition, the initial success rate from cardiopulmonary arrest is poor. By implementing the advanced life support (ALS) course and providing frequent updates on resuscitation skills and management, it is expected that cardiac arrest outcome results should improve. This data is from a 4 year audit of in-hospital cardiac arrest within an adult patient group between January 1993 and December 1996. The average return response of all audit forms was 86.5%. The total sample consisted of 367 separate arrests where the initial rhythm was documented as either ventricular fibrillation (VF)/ventricular tachycardia (VT) (58.3%), asystole (21.7%), electromechanical dissociation (EMD) (7.0%) and other (13.0%). Initial success was defined as return of spontaneous circulation (ROSC). This was achieved in 75.0% of all resuscitation attempts. Within the VF/VT group, successful outcome remained consistent over the 4-year period with an ROSC of 85%. Successful outcome remained consistent in the EMD group, however, the number of arrests was small. Within the asystole group, initial survival increased from 47.5% in 1993-1994 to 67.5% in 1995-1996. These results suggest that BLS and ALS training may only have an impact on initial survival from cardiac arrest.

Adult↗
PubMed2000

Preliminary results with the simultaneous use of implantable cardioverter defibrillators and permanent biventricular pacemakers: implications for device interaction and development.

We report our preliminary experience with the combined use of implantable cardioverter defibrillators (ICD) and biventricular pacemakers in six patients with heart failure and malignant ventricular arrhythmia. Two patients underwent ICD implantation for malignant ventricular arrhythmia after previous biventricular pacemaker implantation. One patient underwent biventricular pacemaker insertion for NYHA Class III heart failure after previous ICD implantation. Two patients underwent single device implantation. In the sixth patient, a combined implantation failed due to an inability to obtain a satisfactory left ventricular pacemaker lead position. The potential for device interaction was explored during implantation. In two patients a potentially serious interaction was discovered. Subsequent alterations in device configuration and programming prevented these interactions with long-term use. No complication of combined device use has been demonstrated during a mean follow-up of 2 months (range 1-4 months). Satisfactory ICD and pacemaker function has also been demonstrated. We conclude that combined device implantation may be feasible with currently available pacing technology and that further prospective studies are required in this area.

Adult↗
PubMed1999

[Simultaneous utilization of an implantable automatic defibrillator in a patient with previously implanted bi-ventricular pacemaker for end-stage heart failure].

We report a case of implantable cardioverter defibrillator (ICD) use after previous biventricular pacemaker insertion for end-stage heart failure. A 75-year-old man with inoperable three-vessel coronary artery disease, permanent atrial fibrillation and end-stage heart failure underwent bi-ventricular pacemaker insertion and His bundle ablation for symptomatic control. NYHA class decreased from class III to II after this procedure. Four months after implant the patient developed paroxysmal sustained, symptomatic ventricular tachycardia. ICD implantation was undertaken. No potentially serious ICD-pacemaker interaction was noted during subsequent follow-up. We conclude that ICD implantation is feasible after previous bi-ventricular pacemaker insertion, without the need to explant the bi-ventricular pacing device.

Aged↗
PubMed1998

Toxicity of atractyloside in precision-cut rat and porcine renal and hepatic tissue slices.

Atractyloside (ATR) causes acute fatal renal and hepatic necrosis in animals and humans. Precision-cut renal cortical and hepatic slices (200 +/- 15 microns) from adult male Wistar rat and domestic pigs, incubated with ATR (0.2-2.0 mM) for 3 h at 37 degrees C, inhibited pyruvate-stimulated gluconeogenesis in a concentration- and time-dependent manner. p-Aminohippurate accumulation was significantly inhibited in both rat and pig renal cortical slices from 0.2 mM ATR (p < 0.05). There was a small decrease in mitochondrial reduction of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium to formazan in both rat and pig kidney slices, which was significant at > or = 2 mM, but no changes in liver slices from either species. However, cellular ATP was significantly depleted at > or = 0.2 mM ATR in kidney and in liver slices from both species. ATR also caused a marked leakage of lactate dehydrogenase and alkaline phosphatase from both pig and rat kidney slices at all concentrations, but only lactate dehydrogenase was significantly elevated in liver slices from both species. ATR > or = 0.5 mM caused a significant increase in lipid peroxidation, but only in liver slices of both species, and > or = 0.2 mM ATR caused a marked depletion of reduced glutathione and significant increase in oxidized glutathione in both kidney and liver slices of both species. However, GSH to GSSG ratio was only significantly altered in the liver slices, indicating that oxidative stress may be the cause of toxicity in this organ. Both rat and pig tissue slices from the same organ responded similarly to ATR, although their basal biochemistry was different. ATR toxicity to both kidney and liver showed similar patterns but it appears that the mechanisms of toxicity are different. While cytotoxicity of ATR in kidney is only accompanied with GSH depletion, that of the liver is linked to both lipid peroxidation and GSH depletion. Striated muscle slices from both species were not affected by the highest ATR concentration. This further strengthens the argument that the molecular basis of ATR, target selective toxicity, is not a measure of the interaction between ATR and mitochondria and that other factors such as selective uptake are involved. Precision-cut tissue slices show organ-specific toxicity in kidney and liver from both rat and pig and suggest different mechanisms of injury for each organ.

Adenosine Triphosphate↗
PubMed1995

Continued prescribing of inappropriate drugs in general practice.

Seven general practitioners used various methods to identify patients in their practices whom they had inherited and whose medication they regarded as inappropriate in the light of current knowledge. Information was collected in each case about the drug concerned, the patient, the original prescriber, and the reason for continued prescribing. Each patient was also interviewed. Altogether, 25 different drugs were prescribed for 40 patients: in 16 the inappropriate drug was one acting on the brain, in 13 an antihypertensive, in seven it was given for heart disease and in three, for asthma. The influence of the original prescriber, and the patient's dependence on the drug, helped to explain its continued use. Almost half the patients said that they might consider changing their medication. The study underlines the importance of reviewing long-term medication and offers a method of scrutinizing repeat prescribing in general practice. Community pharmacists could help in this process.

Adult↗