Usefulness of parathyroid hormone as a predictor of heart failure with preserved ejection fraction

Objective: To investigate the relation between parathyroid hormone (PTH) and heart failure with preserved ejection fraction (HF-PEF) in outpatients.

Methods: One hundred consecutive patients who had preserved left ventricular (LV) ejection fraction and heart failure (HF) symptoms, were enrolled. Echocardiography, assessing the diastolic functions was performed. Blood samples were collected for intact PTH and brain natriuretic peptide (BNP).

Results: Significant correlations between PTH level and predictors of advanced HF-PEF were found (p < 0.05). PTH level and left atrium diameter were found to be independent predictors of DHF.

Conclusion: Measurement of serum PTH provides complementary information for the diagnosis and prognosis of HF-PEF.     

Size as a parameter for tuning visual attention]

The ability of visual attention to tune to the stimulus size (when this size could not be described by spatial frequencies) was studies. Sinusoidal gratings with frequencies of 1.5, 3, and 6 cycle/degree were used as test stimuli. All these stimuli consisted of 3 periods, consequently, they had different sizes: 2 x 2, 1 x 1, and 0.5 x 0.5 degrees. Three reference stimuli had the same sizes but were constructed as a superposition of all the test frequencies. The reference stimulus of suprathreshold contrast was displayed for 400 ms to the left or to the right of a fixation point at a distance of 3 degrees. After that, the test stimulus of threshold contrast was for 100 ms displayed symmetrically to the fixation point on the other side. Subjects were instructed that the sizes of the reference and test stimuli were the same. It was found that the probability of test detection decreased with increase in the difference between the sizes of the reference and test stimuli. Since in our experiments the spatial frequency could not be used for tuning visual attention, the obtained results suggest that there are specialized mechanisms in the visual system for estimation of the general image size.     

Atrial natriuretic factor as a marker in congestive heart failure

Cardiac overload is associated with an overexpression of the atrial natriuretic-factor (ANF) gene in experimental models and in man. Sites of ANF gene overexpression are the atria but also the ventricular myocardium. This recruitment phenomenon of the ventricle to synthesise and secrete ANF is directly dependent on the increase in stress-stretch relationship in each cardiocyte. Therefore, the levels of plasma ANF and its second messenger, cyclic glycophosphate mutase in plasma and urine appear as markers of congestive heart failure in animal models and in man. Particularly, plasma ANF has been recognized recently as independent prognostic factor in congestive heart failure.     

Identification of Nogo as a novel indicator of heart failure.

Numerous genetically engineered animal models of heart failure (HF) exhibit multiple characteristics of human HF, including aberrant beta-adrenergic signaling. Several of these HF models can be rescued by cardiac-targeted expression of the Gbetagamma inhibitory carboxy-terminus of the beta-adrenergic receptor kinase (betaARKct). We recently reported microarray analysis of gene expression in multiple animal models of HF and their betaARKct rescue, where we identified gene expression patterns distinct and predictive of HF and rescue. We have further investigated the muscle LIM protein knockout model of HF (MLP-/-), which closely parallels human dilated cardiomyopathy disease progression and aberrant beta-adrenergic signaling, and their betaARKct rescue. A group of known and novel genes was identified and validated by quantitative real-time PCR whose expression levels predicted phenotype in both the larger HF group and in the MLP-/- subset. One of these novel genes is herein identified as Nogo, a protein widely studied in the nervous system, where it plays a role in regeneration. Nogo expression is altered in HF and normalized with rescue, in an isoform-specific manner, using left ventricular tissue harvested from both animal and human subjects. To investigate cell type-specific expression of Nogo in the heart, immunofluorescence and confocal microscopy were utilized. Nogo expression appears to be most clearly associated with cardiac fibroblasts. To our knowledge, this is the first report to demonstrate the relationship between Nogo expression and HF, including cell-type specificity, in both mouse and human HF and phenotypic rescue.     

Usefulness of serum neopterin levels in acute decompensated heart failure to predict renal dysfunction

Context: Neopterin serum concentration increases in the presence of renal dysfunction.

Objective: We sought to determine the relationship between admission serum neopterin levels and worsening renal function (WRF) in patients with heart failure (HF).

Methods: We prospectively measured serum neopterin levels in patients with HF and the patients were subdivided into two groups: with and without WRF during hospital admission.

Results: Logistic regression analysis showed that high serum neopterin levels at admission were associated with a greater likelihood of developing WRF.

Conclusions: Patients admitted to hospital with HF, elevated serum neopterin levels are associated with an increased risk of developing WRF.     

Usefulness of ELISA and radial immunodiffusion tests for evaluation of the degree of purification of influenza diagnostic and vaccine preparations

It is necessary to use new diagnostic tests for careful and rapid evaluation of a degree of purification and immunogenicity of vaccine anti-influenza preparations. In this study in order to obtain this purpose a radial immunodiffusion++ test and immunoenzymatic test (ELISA) were used Recommended by WHO radial immunodiffusion++ test enable to determine a level of haemagglutinin of particular types and subtypes of influenza virus in polyvalent preparations. However, this test is time consuming therefore for hemagglutinin level determination ELISA test was adapted. This test is hundred times more sensitive and can be applied with success for determination of hemagglutinin level of influenza virus A or B. For evaluation of a degree of purification of vaccine preparations ELISA was elaborated, in which as an index of purification of preparation a level of ovalbumin is determined. This test is specific and extremely sensitive, and it is possible to determine ovalbumin level with accuracy of 1ng in 1 ml of preparation.     

Immune status evaluation of patients with chronic heart failure

Chronic heart failure (CHF) may be considered a state of immune activation and persistent inflammation expressed by increased circulating levels of pro- and anti-inflammatory cytokines. The purpose of the study was to investigate the immune status in patients with CHF compared to normal individuals. We measured serum cytokine levels as well as cytokine production after ex vivo LPS stimulation of whole blood taken from 14 patients with CHF and 14 healthy volunteers. We used 500 pg/ml of LPS for an incubation period of 4h to stimulate 100 microL of whole blood. Patients with CHF had significantly higher levels of TNF-RI, and TNF-RII in serum compared to normal individuals. TNF-alpha, IL-6, and IL-10 did not differ significantly. After LPS stimulation, patients with CHF had significantly higher levels of TNF-alpha and IL-10, and significantly lower IL-6 levels compared to normal individuals. TNF-alpha receptors did not differ significantly. Patients with CHF may be found in a pro- as well as an anti-inflammatory state. They also do not develop endotoxin tolerance in an ex vivo laboratory model using whole blood stimulated with LPS. They may have increased TNF-alpha and IL-10 production after LPS stimulation of whole blood, which may contribute to a worsening of heart function, more severe disease presentation and a worse outcome during infections.     

Right lower lobe oedema as a rare sign of left heart failure

Two cases of right lower lobe oedema are presented as a supposedly very rare sign of left heart failure after myocardial infarction in the presence of acute mitral regurgitation. Causes of unilateral oedema and its clinical relevance in the diagnostic and therapeutic perspectives are discussed, and a review of the literature on this topic is presented.     

Net proton secretion as a parameter for nitrate uptake

Summary Nitrate uptake and its link to net proton secretion in wheat (Triticum aestivum L. cv. Tassilo, Caribo, and Astron) were investigated using a pH-stat system. Since nitrate is taken up in symport with protons, nitrate and proton fluxes should be correlated. Nitrate concentration in the medium, measured by HPLC, decreased in a linear manner. The addition of nitrate caused a drop in net proton secretion rate to negative values (net proton influx). Once nitrate concentration had been lowered to a well defined level, net proton secretion rate started to recover. This critical nitrate concentration depended on the initial nitrate concentration in the medium. A technique to derive nitrate uptake rates from time courses of net proton secretion was developed and is described. Briefly, this method requires the initial nitrate concentration and the time until the minimal net proton secretion rate is achieved. Results determined with this technique were found in excellent agreement to simultaneous direct measurements of nitrate uptake by HPLC. Measurement of net proton secretion therefore can be used as a parameter for nitrate uptake and as a screening method for uptake efficiency. This method was used to compare three varieties of a high nitrogen efficiency breeding line of wheat. The originally less nitrogen efficient variety outperformed the actually sold cultivar in nitrate uptake rate.     

Somatostatin as a modulator of vagal effects on heart rhythm]

In 11 experiments on anesthetised cats burst stimulation of peripheral cut end of right vagus nerve leads to synchronization of cardiac and vagus rhythms. Alterations of burst sequence frequency within definite limits has been synchronously reproduced by heart thus creating managed bradycardia possibility. Somatostatin (10(-8)-10(-9) M intravenously) decreases heart rate and inhibits total vagus chronotropic effect. Vagolytic effect of somatostatin caused a decrease of tonic component of the vagus chronotropic effect. On the other hand, somatostatin augmented the extent of the vagal synchronizing influences and caused enlargement of the ranges of managed bradycardia. The observed results testify to participation of the peptidergic mechanisms in genesis of vagal managed bradycardia.     

Occult aortic stenosis as cause of intractable heart failure

During a three-year period 10 patients with critical aortic stenosis were referred to a cardiac referral centre with symptoms and signs of intractable cardiac failure and low cardiac output. In nine patients the correct diagnosis was not suspected at the referring hospital, and in the remaining patient the true severity of the aortic stenosis was not appreciated and cardiomyopathy was suggested as an additional diagnosis. The most common referral diagnoses were severe mitral regurgitation (four patients), congestive cardiomyopathy (two patients), or both (three patients). Only two patients had soft ejection systolic murmurs at the base of the heart radiating into the neck, and such a murmur appeared in a third patient during medical treatment. The carotid pulses were of small volume but the characteristic slow-rising, anacrotic nature of the pulse could not be appreciated clinically. The diagnosis was suspected in nine patients because of aortic valve calcification detected by lateral chest x-ray examination in seven patients and by x-ray screening of the heart in two, and because of abnormal aortic valve echoes in the echocardiogram of all five patients in whom the aortic valve could be seen. Eight patients underwent aortic valve replacement despite seemingly poor preoperative left ventricular function. Three patients died, of whom two had severe coexistent coronary artery disease. The five survivors all returned to normal lives and needed little or no medication.Critical aortic stenosis should be actively sought in patients with severe heart failure of unknown cause since surgery may enable them to resume their normal lives.