Optimization of ventricular function by improving the activation sequence during ventricular pacing.

Abnormal electrical activation occurring during ventricular pacing reduces left ventricular (LV) pump function. Two strategies were compared to optimize LV function using ventricular pacing, minimal asynchrony and optimal sequence of electrical activation. ECG and hemodynamics aortic flowprobe, thermodilution cardiac output, LV pressure and its maximal rates of rise (LVdP/dtpos) and fall (LVdP/dtneg) were measured in anesthetized open-chest dogs (n = 7) with healthy hearts.

Familial breast cancer risk assessment.

A family, with a strong history of dominant breast and ovarian cancer, is described. Using highly polymorphic microsatellite markers within the BRCA1 breast cancer gene on chromosome 17q21; three affected sisters, their father and a paternal second cousin once removed, are shown to share the same "abnormal" haplotype. Because of this informative linkage, the carrier status of the unaffected siblings can be established by determining whether they inherited their father's "normal" or "abnormal" haplotype.

Acute hemodynamic effects and preload-dependent cardiovascular profile of the partial phosphodiesterase inhibitor nanterinone in patients with mild to moderate heart failure.

Nanterinone (UK-61,260) is a novel positive inotropic and balanced-type vasodilating drug, only partially based on phosphodiesterase III inhibition. Preliminary data from controlled studies suggest satisfactory long-term efficacy and safety. As its acute hemodynamic effects in humans are unknown, an oral dose of 2 mg nanterinone was studied in 14 patients with heart failure (NYHA class II-III) on chronic diuretic and angiotensin-converting enzyme (ACE) inhibitor treatment.

Three-dimensional densitometric reconstruction and visualization of stenosed coronary artery segments.

In this paper we report results from an ongoing study about the diagnostic benefits of three-dimensional (3D) visualization and quantification of stenosed coronary artery segments. Biplane angiographic images do not provide enough information for the exact reconstruction of the coronary arteries. Therefore, a priori information about the 3D shape to be reconstructed must be incorporated into the reconstruction algorithm.

Minibands and chromosome structure. A theory.

Bright and dark field microscopy were used to examine interphase nuclei and RBG-banded human chromosomes. In dark field microscopy both chromosomes and interphase chromatin appeared to be composed of similar independent structures alternating between bright and dull light intensity. The position, colour, and number of these structures may support the theory that the transition from interphase chromatin to metaphase chromosomes, takes place without any dramatic changes in local chromatin structure.

Localization of landmarks and bands in the karyotype of Felis catus.

Using 5-bromodeoxyuridine and Giemsa solution, representative high resolution RBG-banded haploid karyotypes of Felis catus and corresponding idiograms at the 525 band stage were established and the results are discussed.

Hemodynamic, neurohumoral, and myocardial energetic effects of pimobendan, a novel calcium-sensitizing compound, in patients with mild to moderate heart failure.

In contrast to cyclic AMP-dependent positive inotropes, the calcium-sensitizer and partial phosphodiesterase (PDE) inhibitor pimobendan may induce beneficial effects in heart failure. However, its effect on relaxation, myocardial energetics and neurohormones are unknown. Twelve patients with heart failure, New York Heart Association (NYHA) classification II-III, due to ischemic cardiomyopathy, were studied for 1 h after they received 5 mg pimobendan intravenously (i.

Acute systemic and antiischemic effects of epanolol in patients with coronary artery disease.

Antiischemic effects of beta 1-blocking agents are based on intrinsic negative inotropic and chronotropic properties. Partial beta 1-agonistic activity, although useful in preserving cardiac function, may counteract such antiischemic properties by modulating the intrinsic negative cardiac effects of beta-blockade. To investigate the acute hemodynamic and antiischemic profile of epanolol, a cardioselective beta 1-antagonist and partial agonist, 20 patients with left coronary artery disease underwent two incremental atrial pacing tests, 45 minutes before (APST I) and 15 minutes after (APST II) 4 mg intravenous epanolol, administered over 5 minutes.

A severed pacemaker lead entrapped in a hepatic vein.

Complete lead fracture is a uncommon phenomenon in cardiac pacing. Recently we encountered a patient with a severed lead at routine pacemaker follow-up visit. In this case report, the typical ECG changes and noninvasive pacemaker measurements are discussed.

The RBG-banded karyotype of Oryctolagus cuniculus at the 550-band stage.

Representative haploid RBG-banded karyotypes of Oryctolagus cuniculus and diagrammatic representation of the banding patterns at the 550 band stage are presented.

Cellular pharmacology of phosphorothioate homooligodeoxynucleotides in human cells.

The uptake and distribution of phosphorothioate oligodeoxynucleotides by human cells were studied using 35S-labeled 28-mer phosphorothioate oligodeoxycytidine [S-(dC)28]. Accumulation of intracellular S-(dC)28 was found to be higher in the carcinoma cells (grown in monolayers) than in the leukemia cells (grown in suspension culture). A hepatoma cell line transfected with hepatitis B virus, 2215, was chosen for further studies.

Phosphorothioate oligonucleotides are inhibitors of human DNA polymerases and RNase H: implications for antisense technology.

Phosphorothioate oligodeoxycytidine (S-dCn) was used as a model compound to examine the impact of the number of phosphorothioate linkages and their position on the inhibition of human DNA polymerases and RNase H in vitro. S-dCn with a chain length longer than 15 could inhibit human DNA polymerases and RNase H activities, in a linkage number-dependent manner. Longer oligomers were more potent inhibitors than shorter ones.

Abasic oligodeoxyribonucleoside phosphorothioates: synthesis and evaluation as anti-HIV-1 agents.

The syntheses and anti-HIV-1 evaluations of two, abasic oligodeoxyribonucleotide phosphorothioate analogs, d[Cps(Eps)26C] and d[Cps(Vps)26C] (where E and V derive from 1,2-dideoxy-D-ribofuranose and (+/-)-butane 1, 3-diol, respectively), are described.

Neurohumoral activation during acute myocardial ischaemia. Effects of ACE inhibition.

ACE inhibition may be useful in several manifestations of ischaemic heart disease, such as heart failure due to ischaemic cardiomyopathy. Recent evidence suggests that these effects may also be present in normotensive patients with ischaemic heart disease without heart failure. Theoretically, converting-enzyme inhibition, through coronary and systemic vasodilating effects and negative inotropic properties, should have a favourable effect on the myocardial oxygen supply/demand ratio and, hence, affect the incidence and severity of myocardial ischaemia.

Acute hemodynamic and antiischemic properties of intravenous bepridil in coronary artery disease.

The acute hemodynamic and antiischemic effects of intravenous bepridil (3 mg/kg/5 minutes followed by 1 mg/kg/hour) were studied in 19 patients with coronary artery disease under basal conditions and during 2 identical pacing stress tests 30 minutes before (pace test I) and 15 minutes after (pace test II) onset of infusion. Bepridil immediately decreased coronary and systemic vascular resistance (26 and 17%, respectively). This resulted in a 19 and 21% reduction in left ventricular systolic and mean aortic pressures and a 15% increase in coronary flow and stroke index (p less than 0.

Acute antiischaemic properties of high dosages of intravenous diltiazem in humans in relation to its coronary and systemic haemodynamic effects.

The antiischaemic properties of intravenous diltiazem in recommended therapeutic doses are disputed. In 17 patients with coronary artery disease the systemic and coronary haemodynamic effects of diltiazem were assessed during a high-dose infusion (0.4 mg kg-1 per 5 min, followed by 0.

Dose related coronary and systemic haemodynamic effects of intravenous bepridil in patients with coronary artery disease.

The acute coronary and systemic haemodynamic effects of intravenous bepridil were investigated in 27 patients with coronary artery disease; 13 (group 1) received 2 mg kg-1 and 14 (group 2) 4 mg kg-1 over 5 min. An immediate systemic and coronary vasodilation occurred in both groups during and immediately after the infusion. Changes were dose-related with a maximal decrease in left ventricular (LV) systolic pressure of 11% (group 1) and 18% (group 2), in mean aortic pressure of 11% (group 1) and 19% (group 2), and in coronary resistance of 23% (group 1) and 41% (group 2).

Temporal relation of changes in regional coronary flow and myocardial lactate and nucleoside metabolism during pacing-induced ischemia.

The temporal relation between myocardial lactate and hypoxanthine metabolism and regional changes in krypton-81m perfusion during pacing-induced ischemia was studied in 17 patients with coronary artery disease (CAD). During incremental atrial pacing, lactate production and hypoxanthine release occurred early and simultaneously, accompanied by ST-segment changes, but before angina and only few minutes after a significant (17%) reduction in krypton-81m perfusion in areas with more than 90% luminal diameter reduction. During maximal pacing heart rates, krypton-81m distribution decreased to 68 +/- 7% of control in areas with more than 90% diameter reduction and to 80 +/- 4% in 70 to 90% reduction (both p less than 0.