Development of a Bioinformatics Framework for the Detection of Gene Conversion and the Analysis of Combinatorial Diversity in Immunoglobulin Heavy Chains in Four Cattle Breeds.

We have developed a new bioinformatics framework for the analysis of rearranged bovine heavy chain immunoglobulin (Ig) variable regions by combining and refining widely used alignment algorithms. This bioinformatics framework allowed us to investigate alignments of heavy chain framework regions (FRHs) and the separate alignments of FRHs and heavy chain complementarity determining regions (CDRHs) to determine their germline origin in the four cattle breeds Aubrac, German Black Pied, German Simmental, and Holstein Friesian. Now it is also possible to specifically analyze Ig heavy chains possessing exceptionally long CDR3Hs.

An Integrated Care Initiative to Improve Patient Outcome in Schizophrenia.

The optimal treatment of schizophrenia patients requires integration of medical and psychosocial inputs. In Germany, various health-care service providers and institutions are involved in the treatment process. Early and continuous treatment is important but often not possible because of the fragmented medical care system in Germany.

Equine immunoglobulins and organization of immunoglobulin genes.

Our understanding of how equine immunoglobulin genes are organized has increased significantly in recent years. For equine heavy chains, 52 IGHV, 40 IGHD, 8 IGHJ and 11 IGHC are present. Seven of these IGHCs are gamma chain genes.

Inositol-1,4,5-trisphosphate induced Ca2+ release and excitation-contraction coupling in atrial myocytes from normal and failing hearts.

Key Points: Impaired calcium (Ca(2+)) signalling is the main contributor to depressed ventricular contractile function and occurrence of arrhythmia in heart failure (HF). Here we report that in atrial cells of a rabbit HF model, Ca(2+) signalling is enhanced and we identified the underlying cellular mechanisms. Enhanced Ca(2+) transients (CaTs) are due to upregulation of inositol-1,4,5-trisphosphate receptor induced Ca(2+) release (IICR) and decreased mitochondrial Ca(2+) sequestration.

Urocortin 2 stimulates nitric oxide production in ventricular myocytes via Akt- and PKA-mediated phosphorylation of eNOS at serine 1177.

Urocortin 2 (Ucn2) is a cardioactive peptide exhibiting beneficial effects in normal and failing heart. In cardiomyocytes, it elicits cAMP- and Ca(2+)-dependent positive inotropic and lusitropic effects. We tested the hypothesis that, in addition, Ucn2 activates cardiac nitric oxide (NO) signaling and elucidated the underlying signaling pathways and mechanisms.

NFAT transcription factor regulation by urocortin II in cardiac myocytes and heart failure.

Urocortin II (UcnII), a cardioactive peptide with beneficial effects in normal and failing hearts, is also arrhythmogenic and prohypertrophic. We demonstrated that cardiac effects are mediated by a phosphatidylinositol-3 kinase (PI3K)/Akt kinase (Akt)/endothelial nitric oxide synthase (eNOS)/nitric oxide (NO) signaling pathways. Nuclear factor of activated T-cells (NFAT) transcription factors play a key role in the regulation of gene expression in cardiac development, maintenance of an adult differentiated cardiac phenotype, and remodeling processes in cardiac hypertrophy and heart failure (HF).

Subclinical abnormalities in sarcoplasmic reticulum Ca(2+) release promote eccentric myocardial remodeling and pump failure death in response to pressure overload.

Objectives: This study sought to explore whether subclinical alterations of sarcoplasmic reticulum (SR) Ca(2+) release through cardiac ryanodine receptors (RyR2) aggravate cardiac remodeling in mice carrying a human RyR2(R4496C+/-) gain-of-function mutation in response to pressure overload.

Background: RyR2 dysfunction causes increased diastolic SR Ca(2+) release associated with arrhythmias and contractile dysfunction in inherited and acquired cardiac diseases, such as catecholaminergic polymorphic ventricular tachycardia and heart failure (HF).

Methods: Functional and structural properties of wild-type and catecholaminergic polymorphic ventricular tachycardia-associated RyR2(R4496C+/-) hearts were characterized under conditions of pressure overload induced by transverse aortic constriction (TAC).

Exceptionally long CDR3H are not isotype restricted in bovine immunoglobulins.

Exceptionally long third complementarity determining regions of the heavy chain (CDR3H) were previously described as a specificity of bovine IgG and IgM immunoglobulins. In addition, the genomic organization of the immunoglobulin heavy chain locus remains to be elucidated with a special focus on the number of variable segments (IGHV). By analyzing the variable regions according to the isotype-specific PCR using cDNA-PCR, we were able to prove the existence of exceptional long CDR3H in all bovine isotypes.

In situ calibration of nucleoplasmic versus cytoplasmic Ca²+ concentration in adult cardiomyocytes.

Quantification of subcellularly resolved Ca²⁺ signals in cardiomyocytes is essential for understanding Ca²⁺ fluxes in excitation-contraction and excitation-transcription coupling. The properties of fluorescent indicators in intracellular compartments may differ, thus affecting the translation of Ca²⁺-dependent fluorescence changes into [Ca²⁺] changes. Therefore, we determined the in situ characteristics of a frequently used Ca²⁺ indicator, Fluo-4, and a ratiometric Ca²⁺ indicator, Asante Calcium Red, and evaluated their use for reporting and quantifying cytoplasmic and nucleoplasmic Ca²⁺ signals in isolated cardiomyocytes.

cAMP- and Ca²(+) /calmodulin-dependent protein kinases mediate inotropic, lusitropic and arrhythmogenic effects of urocortin 2 in mouse ventricular myocytes.

Background And Purpose: Urocortin 2 is beneficial in heart failure, but the underlying cellular mechanisms are not completely understood. Here we have characterized the functional effects of urocortin 2 on mouse cardiomyocytes and elucidated the underlying signalling pathways and mechanisms.

Experimental Approach: Mouse ventricular myocytes were field-stimulated at 0.

Na+-dependent SR Ca2+ overload induces arrhythmogenic events in mouse cardiomyocytes with a human CPVT mutation.

Aims: Mutations in the cardiac ryanodine receptor Ca(2+) release channel, RyR2, underlie catecholaminergic polymorphic ventricular tachycardia (CPVT), an inherited life-threatening arrhythmia. CPVT is triggered by spontaneous RyR2-mediated sarcoplasmic reticulum (SR) Ca(2+) release in response to SR Ca(2+) overload during beta-adrenergic stimulation. However, whether elevated SR Ca(2+) content--in the absence of protein kinase A activation--affects RyR2 function and arrhythmogenesis in CPVT remains elusive.

Angiotensin II and myosin light-chain phosphorylation contribute to the stretch-induced slow force response in human atrial myocardium.

Aims: Stretch is an important regulator of atrial function. The functional effects of stretch on human atrium, however, are poorly understood. Thus, we characterized the stretch-induced force response in human atrium and evaluated the underlying cellular mechanisms.

Endothelin-1 enhances nuclear Ca2+ transients in atrial myocytes through Ins(1,4,5)P3-dependent Ca2+ release from perinuclear Ca2+ stores.

Nuclear Ca2+ plays a key role in the regulation of gene expression. Inositol (1,4,5)-trisphosphate [Ins(1,4,5)P3)] might be an important regulator of nuclear Ca2+ but its contribution to nuclear Ca2+ signalling in adult cardiomyocytes remains elusive. We tested the hypothesis that endothelin-1 enhances nuclear Ca2+ concentration transients (CaTs) in rabbit atrial myocytes through Ins(1,4,5)P3-induced Ca(2+) release from perinuclear stores.

Urocortin II enhances contractility in rabbit ventricular myocytes via CRF(2) receptor-mediated stimulation of protein kinase A.

Objective: Urocortin II (UcnII), a peptide of the corticotropin-releasing factor (CRF) family, exerts profound actions on the cardiovascular system. Direct effects of UcnII on adult cardiomyocytes have not been evaluated before. Our aim was to characterize functional effects of UcnII on cardiomyocytes and to elucidate the underlying signaling pathway(s) and cellular mechanisms.

Insulin causes [Ca2+]i-dependent and [Ca2+]i-independent positive inotropic effects in failing human myocardium.

Background: Insulin has been shown to exert positive inotropic effects in several in vitro and in vivo models, but signal transduction and substrate dependency remain unclear. We examined inotropic responses and signal transduction mechanisms of insulin in human myocardium.

Methods And Results: Experiments were performed in isolated trabeculae from end-stage failing hearts of 58 nondiabetic and 3 diabetic patients undergoing heart transplantation.