The predictive value of clinical, radiographic, echocardiographic variables and cardiac biomarkers for assessing risk of the onset of heart failure or cardiac death in dogs with preclinical myxomatous mitral valve disease enrolled in the DELAY study.

OBJECTIVES: To identify the predictive value on time to onset of heart failure (HF) or cardiac death of clinical, radiographic, and echocardiographic variables, as well as cardiac biomarkers N-terminal pro brain natriuretic peptide (NT-proBNP) and cardiac troponin I in dogs with preclinical myxomatous mitral valve disease (MMVD). ANIMALS: One hundred sixty-eight dogs with preclinical MMVD and left atrium to aortic root ratio ≥1.6 (LA:Ao) and normalized left ventricular end-diastolic diameter ≥1.7 were included. METHODS: Prospective, randomized, multicenter, single-blinded, placebo-controlled study. Clinical, radiographic, echocardiographic variables and plasma cardiac biomarkers concentrations were compared at different time points. Using receiving operating curves analysis, best cutoff for selected variables was identified and the risk to develop the study endpoint at six-month intervals was calculated. RESULTS: Left atrial to aortic root ratio >2.1 (hazard ratio [HR] 3.2, 95% confidence interval [95% CI] 1.9-5.6), normalized left ventricular end-diastolic diameter > 1.9 (HR: 6.3; 95% CI: 3.3-11.8), early transmitral peak velocity (E peak) > 1 m/sec (HR: 3.9; 95% CI: 2.3-6.7), and NT-proBNP > 1500 ρmol/L (HR: 5.7; 95% CI: 3.3-9.5) were associated with increased risk of HF or cardiac death. The best fit model to predict the risk to reach the endpoint was represented by the plasma NT-proBNP concentrations adjusted for LA:Ao and E peak. CONCLUSIONS: Logistic and survival models including echocardiographic variables and NT-proBNP can be used to identify dogs with preclinical MMVD at higher risk to develop HF or cardiac death.

DELay of Appearance of sYmptoms of Canine Degenerative Mitral Valve Disease Treated with Spironolactone and Benazepril: the DELAY Study.

INTRODUCTION: Efficacy of renin-angiotensin-aldosterone system (RAAS) blockade using angiotensin-converting enzyme inhibitors (ACEi) in dogs with preclinical myxomatous mitral valve disease (MMVD) is controversial. HYPOTHESIS: Administration of spironolactone (2-4 mg q 24 h) and benazepril (0.25-0.5 mg q 24 h) in dogs with preclinical MMVD, not receiving any other cardiac medications, delays the onset of heart failure (HF) and cardiac-related death. Moreover, it reduces the progression of the disease as indicated by echocardiographic parameters and level of cardiac biomarkers N-terminal pro brain natriuretic peptide (NT-proBNP) and cardiac troponin I (cTnI). ANIMALS: 184 dogs with pre-clinical MMVD and left atrium-to-aortic root ratio (LA:Ao) ≥1.6 and normalized left ventricular end-diastolic diameter (LVEDDn) ≥1.7. METHODS: This is a prospective, randomized, multicenter, single-blinded, placebo-controlled study. Primary outcome variable was time-to-onset of first occurrence of HF or cardiac death. Secondary end points included effect of treatment on progression of the disease based on echocardiographic and radiographic parameters, as well as variations of NT-proBNP and cTnI concentrations. RESULTS: The median time to primary end point was 902 days (95% confidence interval (CI) 682-not available) for the treatment group and 1139 days (95% CI 732-NA) for the control group (p = 0.45). Vertebral heart score (p = 0.05), LA:Ao (p < 0.001), LVEDDn (p < 0.001), trans-mitral E peak velocity (p = 0.011), and NT-proBNP (p = 0.037) were lower at the end of study in the treatment group. CONCLUSIONS: This study failed in demonstrating that combined administration of spironolactone and benazepril delays onset of HF in dogs with preclinical MMVD. However, such treatment induces beneficial effects on cardiac remodeling and these results could be of clinical relevance.

Micellar gangliosides mediate the lipid insertion of cholera toxin protomer A.

The topology of the interaction of cholera toxin with ganglioside and detergent micelles was studied with the technique of hydrophobic photolabelling. Cholera toxin alpha and gamma polypeptide chains appear to penetrate into the hydrophobic core of ganglioside micelles. Micelles of SDS cause the labelling also of the beta polypeptide chains, while Triton X-100 micelles have little ability to mediate the labelling of the toxin. The specific reduction of the alpha-gamma disulfide bond allows the penetration of the alpha polypeptide chain into Triton X-100 micelles, but does not affect the interaction of cholera toxin with either ganglioside or SDS micelles. Thus, ganglioside micelles appear to cause a conformational change of the native toxin, such as to induce the penetration of the alpha chain into the micelle hydrophobic core.

Heterogeneity of purified cholera toxin.

The heterogeneity of Vibrio cholerae toxin, obtained from culture filtrates in homogeneous form by gel filtration and preparative disc gel electrophoresis has been studied. By means of disc electrophoresis on polyacrylamide gel cholera toxin was separated into three forms designated I (5%), II (15%) and III (80%). The toxic activity, amino acid content and molecular weight of the three forms were similar. The difference so far observed between the various electrophoretic fractions is a difference in net charge. Incubation of either cholera toxin II or cholera toxin III at relatively high pH leads to the formation of the more acidic forms. These forms, generated in vitro by deamidation of asparagine and/or glutamine residues, are indistinguishable from the toxins of similar electrophoretic mobilities isolated from crude culture filtrates.

The Italian multi-centre project on evaluation of MRI and other imaging modalities in early detection of breast cancer in subjects at high genetic risk.

This report presents the preliminary results of the first phase (21 months) of a multi-centre, non-randomised, prospective study, aimed at evaluating the effectiveness of contrast-enhanced magnetic resonance imaging (MRI), X-ray mammography (XM) and ultrasound (US) in early diagnosis of breast cancer (BC) in subjects at high genetic risk. This Italian national trial (coordinated by the Istituto Superiore di Sanità, Rome) so far recruited 105 women (mean age 46.0 years; median age 51.0; age range 25-77 years), who were either proven BRCA1 or BRCA2 mutation carriers or had a 1 in 2 probability of being carriers (40/105 with a previous personal history of BC). Eight cases of breast carcinomas were detected in the trial (mean age 55.3 years, median age 52.5; age range 35-70 years; five with previous personal history of BC). All trial-detected BC cases (8/8) were identified by MRI, while XM and US correctly classified only one. MRI had one false positive case, XM and US none. Seven "MRI-only" detected cancers (4 invasive, 3 in situ) occurred in both pre- (n = 2) and post-menopausal (n = 5) women. With respect to the current XM screening programmes addressed to women in the age range 50-69 years, the global incidence of BC in the trial (7.6%) was over ten-fold higher. The cost per "MRI-only" detected cancer in this particular category of subjects at high genetic risk was substantially lower than that of an XM-detected cancer in the general women population. These preliminary results confirmed that MRI is a very useful tool to screen subjects at high genetic risk for breast carcinoma, not only in pre-, but also in post-menopausal age, with a low probability of false positive cases.

[Genetic diseases:recent scientific findings and health and ethical problems]. / Malattie genetiche: recenti acquisizioni scientifiche e problemi sanitari ed etici.

Genetic diseases are very numerous, even though rare as single conditions: therefore, overall they represent a significant portion of morbidity at population level. The improvement of molecular genetic techniques has brought a great increase in the diagnostic potential toward genetic diseases, concerning either symptomatic or pre-symptomatic individuals and healthy carriers. However, this has frequently unforeseen consequences, such as a discrepancy between diagnostic and therapeutic potentials. Moreover, the development of genetic tests has raised a number of questions regarding ethical, legal e social problems. The Italian guidelines for genetic tests (available on the Internet site of Istituto Superiore di Sanità: http:@www.iss.it) have been elaborated in 1998 to define general principles for performing and managing genetic tests as well as for programming and promoting genetic testing within the public health system. In accordance with recommendations by international bodies (WHO, EU), the Guidelines give emphasis to the appropriate use of both safe and efficacious tests, the performance in laboratories with high quality standards. A further crucial point is the relationship between the health system and individuals: authonomy of decision, psychological and social assistance, as well as adequate attention to ethical and privacy problems should be guaranteed.

A 31P NMR study on uptake and metabolism of hexose monophosphates in rat diaphragm muscle.

Phosphorus nuclear magnetic resonance spectroscopy was used to study uptake and metabolic conversion of glycolytic intermediates in rat diaphragm muscles. The resonances of several phosphorus-containing metabolites were identified in the intact tissues and in their ethanolic extracts. Experiments on muscles preincubated with glucose 6-phosphate or glucose 1-phosphate indicated that: 1) both substrates penetrate into the tissue and actively participate in glycolytic reactions; 2) glucose 1-phosphate is completely converted into other metabolites, including glucose 6-phosphate and its products; 3) preincubation with either hexose monophosphate in the presence or in the absence of insulin produced the same set of phosphorylated metabolites. Addition of insulin to preincubation media induced a conspicuous spread of chemical shifts in the band arising from phosphorylated sugars in tissues incubated with glucose 1-phosphate but not in those treated with glucose 6-phosphate. The different responses to insulin exhibited by the 31P n.m.r. spectral profiles of tissues incubated with the two substrates substantiate the hypothesis that glucose 6-phosphate and its products may undergo their metabolic conversions in the tissue along distinct intracellular enzymatic pathways, on which insulin would exert different regulatory effects. This study indicates that 31P n.m.r. may provide a useful approach to the elucidation of metabolic processes involving sugar phosphates in intact tissues.