Brain natriuretic peptide for prediction of Cheyne-Stokes respiration in heart failure patients.

Cheyne-Stokes respiration (CSR) is indicative of adverse outcome in patients with chronic heart failure (CHF). We evaluated the use of brain natriuretic peptide (BNP) plasma levels to predict CSR in CHF patients. In this cross-sectional study, overnight polygraphy and cardiac work-up were performed and neurohumoral activation was determined in 102 consecutive CHF patients (25-82 years).

Association of right ventricular dysfunction and Cheyne-Stokes respiration in patients with chronic heart failure.

Cheyne-Stokes respiration (CSR) is present in up to 40% of patients with congestive heart failure (CHF) and is an independent risk factor for increased overall mortality. We examined whether CSR is associated with right ventricular (RV) dysfunction in CHF patients. Parameters of RV function were assessed by two-dimensional echocardiography and tissue velocity imaging in 42 patients (aged 23-75 years) with a left ventricular (LV) ejection fraction below 40%.

Formation of double-walled microtubules and multilayered tubulin sheets by basic proteins.

Some basic proteins enable microtubule protein to form special assembly products in vitro, known as double-walled microtubules. Using histones (H1, core histones) as well as the human encephalitogenic protein to induce the formation of double-walled microtubules, we made the following electron microscopic observations: (1) Double-walled microtubules consist of an "inner" microtubule which is covered by electron-dense material, apparently formed from the basic protein, and by a second tubulin wall. (2) The tubulin of the second wall seems to be arranged as protofilaments, surrounding the inner microtubule in a helical or ring-like manner.

Effect of microtubule-associated proteins on the protofilament number of microtubules assembled in vitro.

In order to demonstrate the effect of microtubule-associated proteins on the protofilament number of microtubules, we used different systems of microtubule formation in vitro in which these proteins are either functionally eliminated (by DNA or glycerol) or absent (purified tubulin). The results obtained by electron microscopy of ultrathin-sectioned material indicate that under standard conditions in the presence of microtubule-associated proteins microtubules are formed consisting predominantly of 14 protofilaments. In cases of deficiency of microtubule-associated proteins, the mean value of the protofilament number is lower, and the protofilament number within the microtubule population varies remarkably.

Physicochemical properties of salt-soluble, unsheared chromatin. Molecular weight studies.

A chromatin fraction, which can reproducibly be extracted from rat liver nuclei at moderate salt concentration (0.1 M (NH4)2SO4, 0.1 M Tris-HCl, 2 mM MnCl2, pH 7.

Physicochemical properties of salt-soluble, unsheared chromatin. The mass per unit length by light scattering.

The mass per unit length of 7 X 10(3) (formula: see text) and the corresponding DNA packing ratio of about 14 for the chromatin soluble at moderate ionic strengths has been determined by light scattering. With the increase in ionic strength and corresponding release of histone H1 the DNA packing ratio has been found to decrease down to 4.4.

Physicochemical properties of salt-soluble, unsheared chromatin. Salt-dependent structural changes.

Salt-dependent structural changes of rat liver chromatin isolated by an extraction procedure not involving shear and exogenous nucleases were investigated by sedimentation and light scattering methods. The effects observed are complex involving changes in the molecular weight and expansion. Between 0.

Isolation and characterization of salt-soluble, unsheared chromatin.

From rat liver nuclei depending on the extraction time, 10 to 20% of total chromatin has been extracted with a solution containing 0.1 M ammonium sulfate, 2 mM MnCl2, 0.1 M Tris-HCl, pH 7.

Salt-and histone H1-induced structural changes of reconstituted minichromosomes.

Structural changes of reconstituted SV 40 minichromosomes have been studied in relation to the salt concentration and addition of histone H1 by sedimentation and electron microscopy. Sedimentation data are represented as functions of the NaCl concentration and the Debye-Hückel electrostatic screening radius 1/alpha. The latter representation which proved to provide more information revealed three structural states of the SV 40 reconstitutes which can be additionally characterized by electron microscopy as follows: Expanded or relaxed conformation including free DNA spacers between the nucleosomes at low salt concentration (approx.

Altered histone-DNA interactions in rat liver chromatin containing 5-bromodeoxyuridine-substituted DNA.

The extractability of the different histone types from rat liver chromatin was studied following the incorporation of bromodeoxyuridine (BrUdR) in liver DNA. This was accomplished by a continuous application of 20 mumol BrUdR/ml/h 17--41 after partial hepatectomy. As a result, thymidine (TdR) replacement by BrUdR of about 80% in the newly-synthesized DNA strand of approx.

[X-ray small angle scattering and x-ray wide angle scattering of single nucleosomes. Preliminary results].

The X-ray scattering diagram from single chromatin subunit particles is registered within a scattering vector intervall from s = 0 to s = 1 1/A. Preliminary results concerning the dimensions and the structure of the nucleosome core particle are communicated.

A sedimentation study of the interaction of superhelical SV40 DNA with H1 histone.

By moving boundary sedimentation it is shown that the interaction of H1 histone with superhelical circular SV40 DNA results in the formation of giant heterogeneous aggregates. The size of these aggregates grows with increasing H1 concentration. s20,w values of some 10 000 S were measured.

Evidence of altered histone interactions, as investigated by removal of histones, in chromatin isolated from rat liver nuclei by a conventional method.

It is shown that the release of the slightly lysine-rich histones f2a2 and f2b by 0.4 M ammonium sulfate from conventionally isolated chromatin is diminished in comparison to the lysed nuclei. The change in extractability is further demonstrated by the application of ethidium bromide.