Expression of the gene for the atrial natriuretic peptide in cardiac myocytes in vitro

Summary Primary cultures of neonatal cardiocytes expreses the gene for atrial natriuretic peptide (ANP). In general the levels of expression follow the rank order: atrial > ventricular nonmyocardial cells. Following the initial dispersion cardlocytes require 48 to 72 hours before ANP seeretion and ANP mRNA accumulation approach a new steadystate level. In situ hybridization analysis indicates that ANP gene expression is concentrated in a subpopulation of cardiocytes in both the atrial and the ventricular cell cultures. These findings suggest that these primary cultures may be of value in defining the faciors governing the expression of the ANP gene in the cardiac cell.     

Increased incidence of life-threatening ventricular arrhythmias in implantable defibrillator patients after the World Trade Center attack

OBJECTIVES: This study was designed to evaluate whether the destruction of the World Trade Center (WTC) on September 11, 2001 (9/11), led to an increased frequency of ventricular arrhythmias among patients fitted with an implantable cardioverter-defibrillator (ICD). BACKGROUND: The WTC attack induced psychological distress. Because ICDs store all serious arrhythmias for months, the attack provided a unique opportunity to compare pre- and post-9/11 frequencies of potentially lethal arrhythmias among ICD patients. METHODS: Two hundred consecutive ICD patients who presented for regularly scheduled follow-up to six affiliated clinics were recruited into this observational study. The electrograms stored in the ICDs for the three months before 9/11 and 13 months thereafter were scrutinized in a blinded manner (relative to date) for all ventricular tachyarrhythmias (tachycardia or fibrillation) triggering ICD therapy. RESULTS: The frequency of tachyarrhythmias increased significantly for the 30 days post-9/11 (p = 0.004) relative to all other months between May 2001 and October 2002. In the 30 days post-9/11, 16 patients (8%) demonstrated tachyarrhythmias, compared with only seven (3.5%) in the preceding 30 days, representing a 2.3-fold increase in risk (95% confidence interval 1.1 to 4.9; p = 0.03). The first arrhythmic event did not occur for three days following 9/11, with events accumulating in a progressive non-clustered pattern. CONCLUSIONS: Ventricular arrhythmias increased by more than twofold among ICD patients following the WTC attack. The delay in onset and the non-clustered pattern of these events differ sharply from effects following other disasters, suggesting that subacute stress may have served to promote this arrhythmogenesis.     

Changes in the histology and function of gastric mucosa and in Helicobacter pylori colonization during a long-term follow-up period after vagotomy in duodenal ulcer patients

BACKGROUND/AIMS: To investigate changes in the histology and the Helicobacter pylori (H. pylori) prevalence and density of the gastric mucosa, as well as in fasting serum gastrin and serum pepsinogen I, depending on completeness of vagotomy, and in cases of recurrent ulcer, during 14 years after operation in duodenal ulcer patients. METHODOLOGY: 122 vagotomized duodenal ulcer patients were studied twice on average 9 and 14 years after operation. The presence of recurrent ulcer and completeness of vagotomy were assessed simultaneously endoscopically and by endoscopic Congo red test. The histology of the gastric antrum and corpus mucosa was assessed in accordance with the Sydney system. The amount of H. pylori in the specimens was detected by microscopic counting; gastrin and pepsinogen I in serum were determined radioimmunologically. RESULTS: During the 14-year follow-up period, complete vagotomy patients were characterized by a smaller amount of active antrum gastritis and a larger amount of active chronic corpus gastritis involving corpus atrophy in 46% of cases 14 years after operation. Recurrent ulcer patients were characterized by a significantly higher prevalence of high-grade H. pylori colonization and active mucosal inflammation in the antrum as well as by a lower level of active mucosal inflammation and atrophy in the corpus and a higher serum pepsinogen I level compared with complete vagotomy cases. The data of incomplete vagotomy patients without recurrent ulcer became more similar to those recorded for recurrent ulcer patients. CONCLUSIONS: In duodenal ulcer patients, changes in the histology of the gastric antrum and corpus mucosa as well as in H. pylori prevalence and density and in serum pepsinogen I levels are different depending on completeness of vagotomy during 14 years after operation.     

A randomised controlled trial of the Buteyko technique as an adjunct to conventional management of asthma

OBJECTIVE: To assess the effectiveness of a non-pharmacological intervention in patients with asthma on conventional therapy including inhaled corticosteroid. DESIGN: A randomised controlled trial of the Buteyko technique in a group of adults with asthma. The control group was trained by a physiotherapist in breathing and relaxation techniques. SETTING: A single centre associated with a University-based asthma programme. MAIN OUTCOME MEASURE: Asthma control, defined by a composite score based on the Canadian asthma consensus report 6 months after completion of the intervention. RESULTS: Both groups showed substantial and similar improvement and a high proportion with asthma control 6 months after completion of the intervention. In the Buteyko group the proportion with asthma control increased from 40% to 79% and in the control group from 44% to 72%. In addition the Buteyko group had significantly reduced their inhaled corticosteroid therapy compared with the control group (p=0.02). None of the other differences between the groups at 6 months were significant. CONCLUSIONS: Six months after completion of the interventions, a large majority of subjects in each group displayed control of their asthma with the additional benefit of reduction in inhaled corticosteroid use in the Buteyko group. The Buteyko technique, an established and widely recognised intervention, or an intensive programme delivered by a chest physiotherapist appear to provide additional benefit for adult patients with asthma who are being treated with inhaled corticosteroid.     

Difficulties of recruitment for a randomized controlled trial involving influenza vaccination in healthy older people

BACKGROUND: In a randomized controlled trial to determine the cost benefits of influenza vaccination in fit healthy individuals aged 65-74 years, recruiting individuals to the study was more difficult than anticipated. OBJECTIVES: To investigate reasons for poor recruitment. MATERIALS AND METHODS: 6,058 people were initially identified as eligible for the study but only 729 (12%) were subsequently randomized. Individuals (n = 2,583) who returned cards indicating that they did not wish to participate were sent a postal questionnaire asking for reasons why they felt unable to consent for the study. RESULTS: 1,173/2,583 (45.4%) questionnaires were returned. A total of 2,621 reasons were given for nonparticipation, i.e. a mean of 2.2 reasons per questionnaire returned. Reasons given for noninvolvement were: reluctance to participate in a research project (53%); concerned about side effects (34%); self-perceived view of not requiring influenza vaccination (31.7%); preference for own doctor to give the vaccine (29.1%); objection to name "Geriatric Medicine" on the letter of invitation (25.2%); already been vaccinated (17.3%); illness requiring vaccination out of the study (13.8%); previous bad reaction to the vaccine (6.4%); unable to attend on day of vaccination (4.3%); unable to get to general practice surgery (4%); already involved in a clinical trial (2.5%); fear of needles/dislike of injections (1.6%); doubts about vaccine efficacy (0.3%); egg allergy (0.2%). CONCLUSION: Inaccurate beliefs about influenza vaccination persist across a wide section of the community. Efforts should be made by all health professionals to correct these false beliefs and ensure that those at risk can be easily recognized and targeted for vaccination.     

Spontaneous arrhythmias in various models of cardiac hypertrophy and senescence of rats. A Holter monitoring study.

OBJECTIVE: The aim was to define experimental models of spontaneous arrhythmias in various models of cardiac hypertrophy in rats. METHODS: Cardiac hypertrophy was induced by several methods and 24 h Holter monitoring was recorded in conscious rats to quantify spontaneous arrhythmias in hypertrophied hearts. Male Wistar rats were studied. A group of young controls 1-2 months old (n = 16) was compared to four groups of animals with cardiac hypertrophy: (1) thyrotoxic rats which received a daily intraperitoneal injection of L-thyroxine for 7 d (n = 6); (2) rats subjected to abdominal suprarenal aortic stenosis (n = 11); (3) senescent rats 22-24 month old (n = 6); and (4) S-DOCA-salt (senescent animals rendered hypertensive by uninephrectomy and DOCA-salt treatment, n = 8). RESULTS: (1) Thyroxine resulted in 20% cardiac hypertrophy, with normal arterial tension, sinus tachycardia, a shorter P wave length and PR interval, and frequent (5/6) atrioventricular block. No premature beats were seen. (2) In aortic stenosis, atria and left ventricle were hypertrophied by 53% and systolic carotid pressure increased by 63%. The incidence of supraventricular premature beats was increased [frequency = 0.70 (SEM 0.3) per 24 h in control v 99(61) in aortic stenosis, p < 0.05]. Ventricular premature beats remained as rare as in control. (3) In senescent and S-DOCA-salt rats all types of spontaneous arrhythmias, but specially supraventricular arrhythmias and atrioventricular block, were frequent. Cardiac hypertrophy produced by DOCA-salt treatment in senescent rats had no effect on the incidence and nature of arrhythmias, but resulted in an increased QTc interval. CONCLUSIONS: Senescent rats and rats with aortic stenosis represent valid models of spontaneous arrhythmias occurring in the absence of ischaemia or toxic insult. Spontaneous arrhythmias in rats are mainly of supraventricular origin. Hyperthyroidism in rats is a model of atrioventricular block probably related to tachycardia. Holter monitoring in rats may have several potential pathophysiological and pharmacological applications.     

The incidence of oral Gram-negative bacteria in patients with Parkinson's disease

Background: Parkinson's disease is a common neurodegenerative disorder that affects an increasing number of older people every year. Dysphagia is not only a common feature, but one that results in poor nutrition and an increased risk of bronchopneumonia. Previous work has suggested that the oral flora is altered in patients with oral pathology. Methods: Fifty patients were assessed to quantify the incidence of oral Gram-negative bacteria. Results: Sixteen of the patients with Parkinson's disease were found to have six different Gram-negative bacilli in their oral cavities. The 20 different Gram-negative bacteria present were Escherichia coli (n=7), Klebsiella spp. (n=3), Kluyvera spp. (n=3), Serratia spp. (n=3), Proteus spp. (n=2) and Enterobacter spp. (n=2). We found that the oral cavity of 16 (32%) of the patients with Parkinson's disease was abnormally colonised with Gram-negative bacteria and that Gram-negative bacteria were more likely to occur in those patients in whom oromuscular dysfunction was present (88% vs. 21%; p<0.05). Conclusion: Further work is required to determine the association between oral flora and the pathogenic organisms found in aspiration pneumonia as well as work on innovative treatments to reduce oral Gram-negative bacteria in those patients at particular risk of aspiration pneumonia.