Echocardiographic assessment of left ventricular outflow tract in d-transposition of the great arteries

The left ventricular outflow tract in 38 patients (aged 0.3 to 13 years) with complete d-transposition of the great arteries, 31 with intraatrial (Mustard) repair, was quantitated with echocardiography, and the findings were correlated with hemodynamic and angiographic data. The left ventricular outflow tract (LVO) was measured on the echocardiogram as an anteroposterior dimension between the closure point on the mitral valve below the pulmonary arterial root (PA) and the left endocardial surface of the interventricular septum. This measurement was expressed as an LVO/PA ratio and on the basis of these measurements three groups were recognized.Group I consisted of 14 patients who had an unobstructed left ventricular outflow tract and no significant pressure differences between the pulmonary artery and left ventricle. In Group II, the 16 patients had evidence of dynamic obstruction and mild to moderate pressure differences between the pulmonary artery and left ventricle, characterized in the echocardiogram by LVO/PA ratios comparable with those of Group I, but with an abnormally prominent early posterior systolic septal bulge in the left ventricular outflow tract, abnormal systolic anterior motion of the mitral valve and coarse fluttering of the pulmonary valve. In Group III the eight patients had anatomically fixed stenosis of the left ventricular outflow tract and severe left ventricular outflow pressure gradients characterized in the echocardiogram by a reduced LVO/PA ratio and fine vibrations of the pulmonary valve. Angiographically discrete or long segmental narrowing of the left ventricular outflow tract correlated well with the echocardiographic data. Echocardiographic measurements of left ventricular posterior wall thickness also correlated well with the severity of left ventricular outflow stenosis in these three groups. The echocardiogram provides clinically useful quantitative and qualitative analysis of the left ventricular outflow tract in patients with complete transposition of the great arteries.     

Assessment of coronary bypass graft patency by electron-beam computed tomography

Twenty-one patients undergoing coronary artery bypass grafting were prospectively evaluated by conventional selective coronary angiography and electron-beam computed tomography. Eighty bypass grafts (60 saphenous vein and 20 left or right internal mammary artery) were evaluated for patency. The sensitivity and specificity of electron-beam computed tomography were 72% and 100%, respectively; positive and negative predictive values were 100% and 92.5%, respectively. Sensitivity and specificity according to coronary region were: left anterior descending artery, 33% and 100%; diagonal artery, 67% and 100%; circumflex artery, 75% and 100%; right coronary artery, 100% and 100%. Electron-beam computed tomography is relatively accurate and a promising tool for noninvasive evaluation of graft patency after coronary artery bypass graft surgery.     

Evaluation of the FASTPlaqueTB assay for direct detection of Mycobacterium tuberculosis in sputum specimens.

SETTING: Sputum samples were collected from suspected tuberculosis patients attending out-patient clinics at the Ojha Institute of Chest Diseases, Karachi, Pakistan. OBJECTIVE: To evaluate the performance of the FASTPlaqueTB assay for rapid diagnosis of pulmonary tuberculosis. DESIGN: A comparative study of 584 sputum samples using acid-fast smear microscopy, Lowenstein-Jensen culture and FASTPlaqueTB. RESULTS: A total of 514 samples yielded complete results. Seventy specimens were lost to analysis due to the overgrowth of contaminants. The addition of antimicrobials inhibited growth of gram-positive contaminants, and reduced the overall contamination rate from 18.2% to 7.2%. Mycobacterium tuberculosis was isolated from 175 smear-positive and 70 smear-negative specimens. FASTPlaqueTB detected M. tuberculosis in 81.6% of specimens, with a specificity of 97.7%. The sensitivity and specificity of the assay for smear-positive specimens were respectively 87.4% and 88.2%. For smear-negative specimens, the sensitivity of the assay was 67.1% and the specificity was 98.4%. The combined sensitivity of smear and FASTPlaqueTB for M. tuberculosis was 90%. Test results were available in 48 hours. CONCLUSION: FASTPlaqueTB is a sensitive and specific test for rapid diagnosis of pulmonary tuberculosis in high prevalence areas. The test is sensitive enough to confirm a large number of clinically suspected smear-negative cases and improve case finding.     

Do practices comply with key recommendations of the British Asthma Guideline? If not, why not?

AIMS: Amongst general practices in the NHS Borders region of Scotland, we aimed to determine compliance with the three key recommendations of the British Guideline for the Management of Asthma and to understand the nature of barriers and facilitators to their implementation. METHODS: Using piloted audit tools, a researcher extracted data from computerised and/or paper patient medical records to assess compliance with recommendations for objective diagnosis and stepwise management. Provision of asthma action plans was assessed by patient survey. Clinicians' attitude to guidelines was assessed by postal survey. RESULTS: Fifteen of the 24 practices in the NHS Borders region participated. Audited compliance with the three key recommendations varied markedly amongst and within practices. Whilst 367/547 (67%) of patients were treated appropriately with add-on therapy, only 58/254 (23%) of patients reported having been given an asthma action plan. Barriers to implementation identified by the clinicians' survey (response rate 64/84 - 76%) were theoretical (doubt about the evidence base and relevance to primary care, lack of knowledge and skills, misconceptions) as well as practical (lack of time and resources) and were exacerbated by poor teamwork. Facilitators were good teamwork and appropriate organisation of work within the practice. CONCLUSIONS: Implementation of key recommendations was variable, particularly in the more complex intervention of issuing asthma action plans. An intervention to enhance compliance with these guideline recommendations will need to address both theoretical and practical barriers within the context of improved teamwork.     

Alcohol-based pressurised metered-dose inhalers for use in asthma: a descriptive study.

BACKGROUND: Chlorofluorocarbons (CFCs) have historically served as the propellants of choice in pressurised metered-dose asthma inhalers, but concern has been raised in recent decades regarding their damaging effect on the ozone layer. Among the alternative propellants being considered is alcohol, which can be used as a co-solvent in asthma inhalers. Healthcare professionals need to be aware of alcohol-containing inhalers, since certain populations may have religious and/or cultural concerns regarding the use of such preparations. OBJECTIVES: To identify pressurised metered-dose asthma inhalers which contain alcohol-based propellants. METHODS: We searched the British National Formulary to identify companies that manufacture asthma treatments and wrote to them to enquire about which of their products contained alcohol and if so in what percentage. These direct contacts were supplemented by searching medical databases and the Internet for additional information. RESULTS: We identified 11 manufacturers of asthma inhalers, seven of which produced pressurised metered-dose inhalers; of these, six were willing to disclose the requested information, and information on the seventh product was obtained from an alternative valid source of information. Most CFC preparations contain alcohol, but CFC- and alcohol-free preparations do exist. CONCLUSIONS: Clinicians need to be aware that the majority of CFC-free inhalers contain alcohol. Alcohol-free, and CFC- and alcohol-free, preparations are available for the delivery of both rescue and preventative treatment and these should be considered for use in those patients who may have concern about alcohol-based treatments.     

Use of pH-impedance testing to evaluate patients with suspected extraesophageal manifestations of gastroesophageal reflux disease

GOALS: To report the use of pH-impedance testing in evaluating patients with suspected gastroesophageal reflux disease (GERD) with atypical symptoms. BACKGROUND: Although the role of acid reflux in causing atypical GERD symptoms is generally accepted, the role, if any, of nonacid reflux is controversial, largely because until recently it has not been possible to detect nonacid reflux. The advent of intraluminal combined pH impedance testing (MII-pH), to detect nonacid reflux has heightened interest in its possible contribution to atypical symptoms. STUDY: Fifty consecutive patients referred for MII-pH testing to evaluate the cause of atypical symptoms presumed due to GERD were evaluated. The symptoms were either refractory to acid inhibition therapy or so atypical that further work up was desired by the referring physician. Patients underwent MII-pH testing to determine whether reflux was present, and, if so, if it was due to acid, nonacid, or gas. RESULTS: Only 16%, 22%, and 2% patients were found to have symptoms due to acid reflux, nonacid reflux, or both, respectively. Ten percent of these patients had gas reflux. MII-pH testing was useful in redirecting the management of patients who did not have reflux as the cause of their symptoms. CONCLUSIONS: MII-pH testing is useful in determining whether gastroesophageal reflux is present in patients with atypical symptoms that have not responded to proton pump inhibitor therapy. It also distinguishes between reflux due to acid, nonacid, and gas, with consequences for management.     

Activity distribution of seven digestive enzymes along small intestine in calves during development and weaning

Ten groups of calves were used to study the changes in activity levels and distribution of seven hydrolases in the intestinal mucosa during development and weaning. The calves in the first group were sacrificed at birth while those in the remaining nine groups were either milk-fed until slaughter on days 2, 7, 28, 56, 70, and 119; or weaned between days 28 and 56 and then slaughtered on days 56, 70, and 119, respectively. The small intestine was immediately cut off and divided into five segments, ie, duodenum, proximal jejunum, median jejunum, distal jejunum, and ileum. In the milk-fed animals, the activity levels of aminopeptidases A and N, alkaline phosphatase, lactase, and isomaltase were maximum at 2 days of age, and then declined sharply between days 2 and 7 but did not change significantly thereafter. By contrast, the maltase activity increased between days 7 and 119, while no sucrase activity was detected. Weaning resulted in a decrease in the activity of lactase and an increase in that of aminopeptidase N, maltase, and isomaltase. The distribution of all these enzymes along the small intestine was slightly influenced by age but not at all by weaning.     

Role of renin-angiotensin system in liver diseases: an outline on the potential therapeutic points of intervention

Introduction: The current review aimed to outline the functions of the renin angiotensin system (RAS) in the context of the oxidative stress-associated liver disease.

Areas covered: Angiotensin II (Ang II) as the major effector peptide of the RAS is a pro-oxidant and fibrogenic cytokine. Mechanistically, NADPH oxidase (NOX) is a multicomponent enzyme complex that is able to generate reactive oxygen species (ROS) as a downstream signaling pathway of Ang II which is expressed in liver. Ang II has a detrimental role in the pathogenesis of chronic liver disease through possessing pro-oxidant, fibrogenic, and pro-inflammatory impact in the liver. The alternative axis (ACE2/Ang(1-7)/mas) of the RAS serves as an anti-inflammatory, antioxidant and anti-fibrotic component of the RAS.

Expert commentary: In summary, the use of alternative axis inhibitors accompanying with ACE2/ Ang(1-7)/mas axis activation is a promising new strategy serving as a novel therapeutic option to prevent and treat chronic liver diseases.