C-type natriuretic peptide and its relation to non-invasive indices of left ventricular function in patients with chronic heart failure.

C-type natriuretic peptide (CNP) significantly increases in chronic heart failure (CHF) patients as a function of clinical severity. Aim of this study was to evaluate in CHF patients the relationship between circulating CNP concentrations and echo-Doppler conventional indices of left ventricular (LV) function as well as less load independent parameters as dP/dt. LV ejection fraction (EF), left ventricular end-diastolic dimension (LVEDD) and LV dP/dt were evaluated together with plasma CNP levels in 38 patients with CHF and in 63 controls. CNP levels resulted significantly higher in CHF patients than in controls (7.19+/-0.59 pg/ml vs. 2.52+/-0.12 pg/ml, p<0.0001). A significant correlation between dP/dt and CNP levels (r=-0.61, p<0.0001) was observed. A good correlation with EF (r=-0.55, p<0.001) and a less significant relation with LVEDD (r=0.316, p<0.05) were also reported. When patients were divided according to dP/dt values a very significant difference in CNP levels was observed: Group I (<600, n=25) vs. Group II (>600, n=13): 8.46+/-0.69 and 4.75+/-0.75 pg/ml, respectively, p<0.001. This is the first study that reports a correlation between CNP and dP/dt in CHF patients, thus suggesting a possible role on cardiac contractility.

[Methodological evaluation of an enzyme-immunoassay for plasma Big-et-1 determination]. / Valutazione metodologica di un metodo immunoenzimatico per la determinazione della Big-endotelina-1.

BACKGROUND: The evaluation of big-endothelin (ET)-1 plasmatic concentrations may serve as another noninvasive marker in patients with cardiovascular diseases, based on the assumption that it may reflect endothelin overproduction more accurately than circulating ET-1. For this reason the analytical performance of an immunoenzimatic assay for plasma Big-ET-1, with or without a preliminary step of extraction, was evaluated. METHODS AND RESULTS: Sensitivity for direct assay was 0.15+/-0.010 fmol/ml (n=27), inter-assay variability, evaluated at 2 different concentrations, resulted 2.5+/-0.062, CV%=5.6 (n=5) and 1.47+/-0.09 fmol/ml, CV%=12.8 (n=4), respectively, while intra-assay variability was 0.89+/-0.022 fmol/ml, CV%=5.6. Sensitivity for the assay with extraction resulted 0.71+/-0.104 (n=6) fmol/ml and intra-assay variability was 3.6+/-0.13 fmol/ml, CV=7.4% (n=4). The comparison between the 2 procedures, performed on 107 plasma samples at different peptide concentrations, showed a close agreement between the results of the 2 procedures for Big-ET-1 values higher than 1 fmol/ml. CONCLUSION: The main limitation of the direct assay is due to possible interference effects while the correct evaluation of extraction yield of the individual samples is the main drawback of the procedure with extraction. These effects become important when assaying samples with low levels of analyte. The direct assay of plasma Big-ET-1, easier to perform, more rapid and less expensive, could be the choice method.

Ulnar nerve entrapment in Guyon's tunnel by an anomalous palmaris longus muscle with a persisting median artery.

A case of ulnar nerve entrapment in Guyon's tunnel caused by an aberrant palmaris muscle, associated with a patent median artery and duplication of the median nerve, is reported.

Adiponectin circulating levels: a new emerging biomarker of cardiovascular risk.

Fat is now considered as an endocrine organ that produces a lot of molecules having biological activity, called adipocytokines. Among these, adiponectin, a 247 amino acid protein produced abundantly and specifically by adipose tissue, besides its effects on glucose metabolism, plays important protective function against cardiovascular diseases. Circulating levels lower than those of healthy control subjects have found to be associated to conditions such as obesity, diabetes and cardiovascular diseases. In animal experimental models, administration of adiponectin has been shown to have beneficial effects against the development of obesity-related vascular diseases, including atherosclerosis. In humans, circulating levels can be raised by life style modification (weight loss or exercise training) or pharmacological treatments. Adiponectin is present in the human plasma in different isoforms: a large multimeric structure of high molecular weight and in a trimer and examer form, whereas the monomeric form is found only in the adipose tissue. The biological activities of the different multimers are not yet fully known, although the different isoforms appear to have different functional importance following the different diseases. This paper reports the main biological features of adiponectin in order to highlight its possible role as diagnostic/prognostic marker in cardiovascular diseases. Particular attention is paid to practical considerations relative to the analytical determination of this protein in humans.

Effects of aging and anti-aging caloric restrictions on carbonyl and heat shock protein levels and expression.

Heat shock proteins (Hsps) are induced by stressful stimuli and have been shown to protect cells and organs from such stresses both in vitro and in vivo, and play a positive role in lifespan determination. An attenuated response to stress is characteristic of senescence and no Hsp induction is observed upon exposure to stress and no protective effect of a mild stress is observed in cells from aged individuals. The artificial over-expression of Hsps, can produce a protective effect against a variety of damaging stimuli in cells from aged rats or aged humans, in whom cardiovascular disease is a major cause of morbidity in older age. Here, we show that aging significantly decreases the levels of Hsp27, Hsp60, Hsp72 and Hsc70 in right atrium and left ventricle of the rat heart, both at level of protein and of mRNA. Two different caloric restriction regimens have been found to counteract in part the decrease in the levels of Hsp expression in the aged heart tissue as well as the tendency to an increase of the levels of carbonyl in cardiac proteins. Our data suggest that cardiac Hsp levels may be a determinant of longevity in rodents, and that generation of new regimens of caloric restriction may eventually show how to improve modulation of cardiac aging.

The effects of the administration of tamoxifen, ethynyloestradiol, and prednisolone on the activities of certain enzymes of carbohydrate metabolism in primary human breast carcinomas in vivo.

Postmenopausal patients with primary breast cancer were treated with tamoxifen, ethynyloestradiol or prednisolone for up to 12 days before mastectomy and the effects of pretreatments with these drugs on the activities of phosphofructokinase (PFK), 6-phosphogluconate dehydrogenase (6PGDH) and alpha-glycerolphosphate dehydrogenase (alpha-GPDH) in the carcinomas were compared with age, stage and menopausal status matched untreated controls. The administration of tamoxifen or prednisolone resulted in a significant increase in the activity of alpha-GPDH and the alpha-GPDH/6PGDH ratio, whereas ethynyl-oestradiol treatment produced a significant decrease in the activity of the enzyme and the ratio. When tamoxifen and ethynyl-oestradiol were administered together, it was found that tamoxifen failed to reverse the oestrogen-induced reduction in the activity of alpha-GPDH. Since increased activity of the enzyme or a higher alpha-GPDH/6PGDH ratio are associated with a lower risk of recurrence (Deshpande et al., 1981), it is postulated that the beneficial effects of tamoxifen or prednisolone in terms of prolongation of the relapse free interval might be mediated via alterations in the activity of alpha-GPDH in micrometastases. The activities of PFK and 6PGDH remained unaffected by these treatments.