Spiral computed tomography angiography (SCTA) and color coded duplex ultrasound (CCDUS): two complementary diagnostic techniques for assessment of extracranial cerebral artery stenosis

Atherosclerotic lesions of the extracranial cerebral arteries account for ischemic stroke in over half of all cases. The risk of stroke associated with symptomatic carotid artery disease is related to the severity of the stenosis. Results of the two major clinical trials, North American Symptomatic Carotid Endarterectomy Trial (NASCET) and European Carotid Surgery Trial (ECST), showed that patients with symptomatic carotid artery disease may benefit from carotid endarterectomy. Therefore, detection and quantification of stenosis are essential. Discrepancies in the angiographic criteria used in both NASCET and ECST trials resulted in continued controversy about the most accurate method of measuring carotid artery stenosis. Moreover, to avoid complications related to the angiography procedure, a good evaluation of vessel wall and plaque composition need to be considered. Both SCTA and CCDUS are non invasive techniques that could overcome angiographic complications and give detailed information on stenosis grading and plaque characteristics. They have been used to evaluate carotid stenosis as a single or combined methods.     

Effect of Blood Ammonia Elevation Following Oral Glutamine Load on the Psychometric Performance of Cirrhotic Patients

Oral glutamine challenge is a method to increase blood ammonia and may be used to study the ammonia lowering effect of drugs potentially useful in hepatic encephalopathy (HE). We tested its influence on the psychometric performance of 18 cirrhotic patients without HE. Twelve nonencephalopatic cirrhotic patients were studied before and after glutamine load (20 g in 100 mL tap water) and six patients before and after placebo (100 mL tap water) by using the Number Connection Test (NCT), the Covert Visual Attention Orienting Test (CVAOT), and the Scan Test (SCT). Blood ammonia increased significantly after glutamine (from 79 ± 34 to 211 ± 66 g/dL) but not after placebo (from 94 ± 41 to 88 ± 26). No difference in the NCT was found before and after glutamine load or placebo. The CVAOT was similar after glutamine challenge and placebo, nor any interaction between Loads (glutamine or placebo) × Cue position was found, suggesting that glutamine load did not influence attention-orienting. SCT results were also similar after glutamine and placebo, suggesting a lack of influence on the working memory. Glutamine challenge is a safe method to induce hyperammonemia in nonencephalopatic cirrhotic patients and, therefore, to study the efficacy of ammonia lowering treatments.     

Co-administration of nitric oxide-aspirin (NCX-4016) and aspirin prevents platelet and monocyte activation and protects against gastric damage induced by aspirin in humans

OBJECTIVES: The goal of this study was to test the hypothesis that NCX-4016 may have broader anti-inflammatory and antithrombotic effects as well as better gastric tolerability than aspirin in humans. BACKGROUND: NCX-4016 is an aspirin derivative containing a nitric oxide-releasing moiety that prevents platelet activation and modulates tissue factor (TF) expression and cytokine release from lipopolysaccharide (LPS)-stimulated monocytes. METHODS: This was a blind-observer, placebo-controlled, parallel-group study in which 48 healthy subjects were randomized to receive NCX-4016 800 mg twice a day, NCX-4016 800 mg twice a day plus aspirin 325 mg, aspirin 325 mg, or placebo for 21 days. RESULTS: Similar to aspirin alone, NCX-4016 effectively inhibited platelet aggregation induced by 0.6 mmol/ arachidonic acid, clot-stimulated thromboxane (TX) B2 generation in whole blood, and urinary excretion of 11-dehydro-TXB2. Unlike aspirin alone, the administration of NCX-4016 significantly inhibited TF expression in monocytes stimulated ex vivo with 10 micromol/l LPS (determined by flow-cytometry analysis of TF on CD14 positive cells). NCX-4016 also inhibited the rapid TF expression induced in monocytes by a proteinase activated receptor agonist (thrombin receptor activator protein, 2 micromol/l) as well as LPS-induced expression of CD11b . Ex vivo, release of MCP-1 and interleukin-6 were significantly inhibited by NCX-4016, but not by aspirin. NCX-4016 was not associated with gastric damage, and significantly reduced gastric injury when co-administered with aspirin, although both drugs reduced gastric PGE2 production to the same extent. CONCLUSIONS: NCX-4016 is equally effective as aspirin in inhibiting cyclooxygenase activity. However, NCX-4016 causes less gastric damage and prevents monocyte activation. Larger multicenter trials are warranted to establish clinical efficacy and safety of NCX-4016.     

Visceral leishmaniasis: current status of control,diagnosis, and treatment,and a proposed research and development agenda

Visceral leishmaniasis is common in less developed countries, with an estimated 500000 new cases each year. Because of the diversity of epidemiological situations, no single diagnosis, treatment, or control will be suitable for all. Control measures through case finding, treatment, and vector control are seldom used, even where they could be useful. There is a place for a vaccine, and new imaginative approaches are needed. HIV co-infection is changing the epidemiology and presents problems for diagnosis and case management. Field diagnosis is difficult; simpler, less invasive tests are needed. Current treatments require long courses and parenteral administration, and most are expensive. Resistance is making the mainstay of treatment, agents based on pentavalent antimony, useless in northeastern India, where disease incidence is highest. Second-line drugs (pentamidine and amphotericin B) are limited by toxicity and availability, and newer formulations of amphotericin B are not affordable. The first effective oral drug, miltefosine, has been licensed in India, but the development of other drugs in clinical phases (paromomycin and sitamaquine) is slow. No novel compound is in the pipeline. Drug combinations must be developed to prevent drug resistance. Despite these urgent needs, research and development has been neglected, because a disease that mainly affects the poor ranks as a low priority in the private sector, and the public sector currently struggles to undertake the development of drugs and diagnostics in the absence of adequate funds and infrastructure. This article reviews the current situation and perspectives for diagnosis, treatment, and control of visceral leishmaniasis, and lists some priorities for research and development.     

Outcome of anti-HBe positive chronic hepatitis B in alpha-interferon treated and untreated patients: a long term cohort study

BACKGROUND/AIMS: We studied the influence of biochemical and virologic patterns and interferon on the outcome of anti-HBe positive chronic hepatitis B in 164 (103 treated) consecutive patients, followed-up prospectively for a mean of 6 years (21 months-12 years). METHODS: Histology, biochemical and virologic profiles were characterized by monthly monitoring during the first 12 months of follow-up. Thereafter patients underwent blood and clinical controls every 4 and 6 months, respectively. Cirrhosis at follow-up histology or end stage complications of cirrhosis served as end points for the analysis of factors influencing disease progression in patients with baseline chronic hepatitis or cirrhosis, respectively. RESULTS: Disease progression was associated with older age (P<0.001), absence of previous HBeAg history (P=0.017) and higher serum HBV-DNA levels (P=0.009) (more frequently observed in unremitting disease profile, P=0.012) at multivariate analysis. Fluctuations of IgM anti-HBc levels (associated with disease exacerbations, P=0.045) correlated with end stage complications in cirrhotics (P=0.011). Disease improved in 14.6 and 1.6% of treated and untreated patients, respectively (P=0.015): interferon slowed disease progression (P<0.001). CONCLUSIONS: The outcome of anti-HBe positive chronic hepatitis B is worsened by older age and persistent viral replication or hepatitis exacerbations in chronic hepatitis or in cirrhotic patients, respectively. Interferon reduces by 2.5-folds disease progression.     

Effect of plasma metformin concentrations on serum lipid levels in type II diabetic patients

Summary In this study we evaluated the relationships between plasma metformin levels, measured by reversed-phase high-performance liquid chromatography, and serum lipid levels in 20 metformintreated, type II diabetic patients. Mean fasting plasma metformin concentration was 490 ± 188 ng/ml. No correlation was found between daily dose of drug and lipid parameters. A significant correlation emerged between circulating metformin concentration and serum triglycerides (r=−0.574, p<0.01), HDL-cholesterol (r=0.583, p<0.01) and HDL₂-cholesterol (r=0.670, p<0.05). Multiple linear regression analysis showed that the correlation between plasma metformin concentration and serum triglycerides still remained significant after correction for other clinical and metabolic parameters. Total cholesterol and HDL₃-cholesterol were not correlated with metformin concentrations. These results demonstrate the clinical usefulness of measuring plasma metforminc concentrations and indicate that some effects of metformin on lipid metabolism depend on the drug plasma levels.     

How general practitioners perceive and grade the cardiovascular risk of their patients.

BACKGROUND: Although risk assessment charts have been proposed to identify patients at high cardiovascular risk, in everyday practice general practitioners (GPs) often use their knowledge of the patients to estimate the risk subjectively. DESIGN: A cross-sectional study aimed to describe how GPs perceive, qualify and grade cardiovascular risk in everyday practice. METHODS: General practitioners had to identify in a random sample of 10% of their contacts the first 20 consecutive patients perceived as being at cardiovascular risk. For each patient essential data were collected on clinical history, physical examination and laboratory tests, for the qualification of risk. At the end of the process GPs subjectively estimated the overall patient's level of risk. General practitioners grading was compared with the risk estimate from a reference chart. RESULTS: Over a mean time of 25 days 3120 patients perceived as being at cardiovascular risk were enrolled. According to the inclusion scheme each GP had contact with more than 200 patients at cardiovascular risk every month. Thirty percent of these patients had atherosclerotic diseases. Up to 72% of patients without any history of atherosclerotic diseases but perceived to be at risk could be classified according to a reference chart as being at moderate to very high risk. Comparing GPs' grading of risk with a chart estimate there was agreement in 42% of the cases. Major determinants of GPs' underestimation of risk were age, sex and smoking habits, while obesity and family history were independently associated with overestimation. CONCLUSIONS: On the basis of their perception GPs properly identify patients at cardiovascular risk in the majority of cases. General practitioners subjective grading of risk level only partially agreed with that given by a chart.