Preexcitation in Hypertrophic Cardiomyopathy: A Case of a Fasciculoventricular Mahaim Fiber

STELLBRINK, C., et al .: Preexcitation in Hypertrophic Cardiomyopathy: A Case of a Fasciculoventricular Mahaim Fiber . A patient with hypertrophic cardiomyopathy (HCM) who presented with preexcitation pattern on the surface ECG suggestive of the Wolff-Parkinson-White (WPW) syndrome is described. Intracardiac electrophysiological study revealed a fixed anomalous QRS complex and a short fixed His-ventricular interval indicating a fasciculoventricular Mahaim fiber. As this specific form of accessory connection does not cause reentrant tachycardias, no treatment was required. It is important to distinguish this entity from atriofascicular or nodoventricular Mahaim fibers or the WPW syndrome in patients with HCM showing a preexcitation pattern in the surface ECG, as these may cause life-threatening arrhythmias in this patient population.     

Conformational stability of antamanide and analogs Crystal structure of perhydrosymmetric antamanide,cyclic (-Val-Pro-Pro-Cha-Cha-Val-Pro-Pro-Cha-cha-)

The synthetic perhydrogenated symmetric analog of the cyclic decapeptide antamanide is biologically inactive, although the conformation of the molecule and the crystal packing are very similar to that of the active symmetric analog of antamanide. In fact, the same conformation for the molecule has now been found in six polymorphs of uncomplexed antamanide and its analogs. The differences between the active and inactive antamanide analogs are displayed dramatically in the conformations of their metal ion (Na⁺ or Li⁺) complexes, thus suggesting strongly that for physiological activity antamanide is not in the conformation assumed by the uncomplexed molecule, but rather in the conformation assumed by the complexed state of natural antamanide. The present structure crystallizes in space group P2₁2₁2₁ with a = 20.515(14) Å, b = 21.316(16) Å, c = 17.128(16) Å and four peptide molecules in the unit cell. There are three cocrystallized water molecules at full occupancy intrinsic to the peptide, and several more water molecules or other solvent molecules at partial occupancy. The formula of the peptide is C₆₆ H₁₀₆ N₁₀O₁₀· 4-H₂O·2X.     

Liposomal 1,25 (OH)2 vitamin D3 compounds block proliferation and induce differentiation in myelomonocytic leukaemia cells

The vitamin D₃ derived hormone 1,25 (OH)₂ vitamin D₃ (1,25 D₃) is able to induce growth arrest and differentiation in myelomonocytic leukaemia cells. In order to allow for specific delivery to leukaemic cells the lipophilic compound was incorporated into the lipid membranes of liposomes. Liposomal 1,25 D₃ reduced proliferation as measured by ³H-thymidine incorporation in HL60 leukaemia cells by up to 60%. When liposomes were prepared at different concentrations of 1,25 D₃ 65% inhibition was achieved at 48 n M . The MC 1288 stereoisomer of 1,25 D₃ was more potent and had the same activity at 48 n M .
The effect of the liposomal compounds was specific to myeloid cells as they reduced proliferation in myelomonocytic HL60, monoblastic U937 and monocytic Mono Mac 6 cells but not in the T-cell lines Jurkat and Molt 4.
The antiproliferative effect of liposomal 1,25 D₃ was associated with an induction of differentiation since treated HL60 cells showed a monocytic morphology, increased expression of CD14 and decreased expression of CD33.
When peripheral blood leukaemic cells from M4 and M5 acute myeloid leukaemia (AML) patients were admixed with liposomal compounds an antiproliferative effect was seen in all five cases, including the two cases where free compounds led to enhanced growth. Liposomal delivery of 1,25 (OH)₂ vitamin D₃ may offer a novel approach to treatment of myelomonocytic leukaemia.     

Transcoronary Venous Radiofrequency Catheter Ablation of Ventricular Tachycardia

Coronary Venous Ablation of VT. Ventricular tachycardias in coronary artery disease arise mostly from endocardial sites. However, little is known about the site of origin in other diseases. We present the case of an incessant, adenosine-sensitive ventricular tachycardia arising from the lateral wall of the left ventricle in a patient with mildly reduced left ventricular function. Intracardiac mapping suggested an epicardial origin, and the tachycardia was successfully ablated from a coronary sinus branch. After ablation, left ventricular function returned to normal. Transcoronary venous radiofrequency catheter ablation is a new approach for the treatment of ventricular tachycardia. Its value in the management of other types of ventricular tachycardia has yet to he determined.     

Vecuronium titration for muscle relaxation in myotonic dystrophy

A 14-year-old boy with pronounced myotonic dystrophy and cardiac malformation had a normal ED₉₅ (53 μg·kg^?1) of vecuronium, whereas the recovery index (25-75% twitch recovery) was three times as long as in the absence of neuromuscular disease. We conclude that in young patients with dystrophic muscle disease individual titration of the muscle relaxant with the aid of a nerve stimulator does not preclude a considerable delay in the recovery of neuromuscular transmission.     

The impact of performance uncertainty on the postimperative negative variation

In a delayed matching-to-sample task, the impact of clear or ambiguous go versus clear no-go signals on the post-imperative negative variation (PINV) was examined in 11 patients with a chronic schizophrenic disorder (DSM-III-R) and in a control group of 13 healthy subjects matched to the patient sample by age, sex, and education. Size and spatial position of a visual S2 had to be matched to one of two visual patterns in the S1 presented 4 s earlier. In 96 trials, the S2 was identical in size with one of the two patterns of S1 (clear matching). These trials varied pseudorandomly, with 60 trials in which the S2 was of intermediate size. On a randomly interspersed additional 48 trials, an S2 differing in color and shape signaled no-go. The electroencephalogram was recorded from Fz, Cz, Pz, F3, F4, C3, C4, P3, and P4. Although groups did not differ in contingent negative variation amplitude the PINV was generally more pronounced in patients than in controls. In both groups, ambiguity of the to-be-matched S2 produced larger PINV amplitudes; the no-go signal elicited only a small PINV. Differential effects of ambiguity and no-go on PINV amplitude and its scalp distribution suggest that “performance” and “action” uncertainty contribute to PINV generation and that thresholds for both effects are reduced in schizophrenics.     

Fourth polymorph of [Phe 4 Val 6] antamanide (pentahydrate)

The cyclic decapeptide antamanide and the synthetic, biologically active analog [Phe⁴ Val⁶] antamanide (cyclic[ValProProPhePhe]₂) crystallize in various crystal forms as a function of the solvent. The present crystalline polymorph obtained from acetone/water (also from ethanol/water and DMSO/water) crystallizes in space group P2₁2₁2₁ with a = 20.194 (30) Å, b = 21.118 (31) Å, c = 16.132 (25) Å and four molecules of peptide in the unit cell. There are five cocrystallized water molecules per peptide molecule, of which four water molecules are intrinsic to the peptide molecule. Although the molecular packing is entirely different in each of the polymorphs, the conformation of the peptide molecule, including the intrinsic water molecules, is very similar in all the polymorphs.     

Reforming health care for the elderly--the example of Vorarlberg

Vorarlberg—Austria'S most western province with a populationof about 325 000—has always implemented forms of socialpolicy in which the principles of subsidiarity and solidarityplay an important role. This is reflected in the structure ofthe organizations traditionally providing social services aswell as in the more recent programme.s the government has developedfor social policy. This paper discusses two cases in point: the private associationsfor home care (Krankenpflegerverbände)—which nowexist in 65 Vorarlberg communities and cover 85% of the populationin the province—offering nursing services at home to membersor to persons who are willing to join the organization whenthey need care, and the new organizational model, called GesunderLebensraum Vorarlberg (GLV), which is successfully operatingin a few pilot communities. GLV has spawned umbrella organizations,run by volunteers, and offering a variety of social servicesrelevant to the elderly, for example visiting services or neighbourhoodhelp in case of emergencies. The volunteers get organizationalhelp from a profit-making firm financed by the government. The Vorarlberg models can be interpreted as a step towards demedicalizationand dein.stitutionalization of health care for the elderly.Nevertheless, they also show the problems that arise when professionalsand volunteers must cooperate. The models may lead to savingsfor the governments involved, although details are still subjectto future empirical investigations.     

Water structure in [Phe4 Val6] antamanide • 12H2O crystallized from dioxane

Crystals of [Phe⁴ Val⁶] antamanide (cyclic[ValProProPhePhe]₂) grown from dioxane/H₂O, with space group P2₁2₁2 and cell parameters a= 15.099(4), b = 22.008(5) and c = 11.024(3) Å, are almost identical to crystals grown from H₂O/acetone, the structure of which was determined a number of years ago. Perpeptide molecule there are the equivalent of 12 water molecules occupying 16 sites in both crystals; however, in the new investigation a number of water molecules present at one-half occupancy have been found in different positions than in the earlier analysis. The interpretation of the hydrogen bonding between peptide/water and between water/water is much more satisfactory. Pentagonal water assemblies are present in the solvent channel. There is a distinct indication of the occurrence of a bifurcated bond between two water molecules, as well as the presence of three-center hydrogen bonds joining three water molecules. This may be the first experimental example of a bifurcated bond between two water molecules.