Comparative conformational analyses of μ-selective dermorphin and §-selective deltorphin-II in aqueous solution by 1H-NMR spectroscopy

Two-dimensional ¹H-NMR methods have been used to obtain complete proton resonance assignments and possible solution conformations of dermorphin (H-Tyr-D-Ala-Phe-Gly-Tyr-Pro-Ser-NH₂) and deltorphin-II (H-Tyr-D-Ala-Phe-Glu-Val-Val-Gly-NH₂), naturally occurring μ and §-selective opioids, respectively, in order to examine the conformational characteristics that are closely related to the selectivities towards μ/§ opioid receptors. With the use of the proton-proton distances derived from ROESY measurements in aqueous solution, 50 possible 3D structures are generated by means of distance geometry calculations. The conformers which satisfy the distance constraints and the torsion angles estimated from J_NHCxH vicinal coupling constants within the allowable range are then subjected to molecular dynamics simulations for 10 ps after equilibration. Although dermorphin and deltorphin-II are both in equilibrium among many flexible conformers, some conformational differences are observed between these peptides: many conformers of dermorphin show a structure rounded at the N-terminal Tyr-D-Ala-Phe-Gly-Tyr and C-terminal Gly-Tyr-Pro-Ser-NH₂ moieties, which are almost at right angles to each other, while those of deltorphin-II are characterized by a ‘hook’ -shaped backbone structure in which the nearly extended conformation of the Val-Val-Gly-NH₂ sequence is located under the folded conformation of the N-terminal Tyr-D-Ala-Phe-Glu sequence. The possible relationship between these conformational characteristics and the μ/§-opioid receptor selectivities is discussed.     

Relationship between nocturnal urinary frequency and sleep disturbances in aged men

Abstract The relationship between nocturnal urinary frequency and sleep disturbances is investigated in aged men in 12 rural towns in Kyoto and Shiga Prefectures. The subjects were 178 men who did not have diseases or symptoms that were likely to affect urinary condition or sleep. There were no significant differences in sleep disturbances, except sleep maintenance, between the normal group (nocturnal urinary frequency below twice per night) and the abnormal group (nocturnal urinary frequency twice or more per night). In healthy aged men, nocturnal urinary frequency only caused disturbance in sleep maintenance, but did not cause any other sleep disturbance.     

Evaluation of Oral Mucoadhesive Microspheres in Man on the Basis of the Pharmacokinetics of Furosemide and Riboflavin,Compounds with Limited Gastrointestinal Absorption Sites

When sustained-release adhesive and non-adhesive microspheres which release the same drugs at similar rates are administered orally, drug absorption after administration of adhesive microspheres should, if the gastrointestinal residence of adhesive microspheres is prolonged as a result of mucoadhesion, be higher than that after administration of non-adhesive microspheres. The gastrointestinal transit of oral adhesive microspheres in man has been evaluated pharmacokinetically using furosemide and riboflavin, compounds with limited absorption sites in the upper small intestine. In a preliminary experiment with fasted rats it was confirmed that a higher percentage of the drug remained in the stomach and that plasma drug levels were higher when furosemide was administered in the form of adhesive rather than non-adhesive microspheres. Two kinds of sustained-release microsphere, adhesive and non-adhesive, containing furosemide and riboflavin in hard gelatin capsules were prepared and orally administered to 10 healthy fasted volunteers in a cross-over design. Areas under the plasma concentration-time curves (AUC) were 1.8 times larger for furosemide and urinary recovery was 2.4 times higher for riboflavin when adhesive microspheres rather than when non-adhesive microspheres were used. When adhesive microspheres containing riboflavin were administered to fed volunteers, urinary recovery was 2.1 times higher and mean residence time (MRT) was more prolonged than when the microspheres were administered to fasted volunteers. Adhesive microspheres were found to adhere to the gastric or intestinal mucosa with high affinity in man and rats, resulting in prolonged gastrointestinal residence.     

Experimental His-Bundle Pacing: Histopathological and Electrophysiological Examination

His-bundle pacing gives a more physiological ventricular contraction in comparison to right ventricular apical pacing. However the problems of lead fixation and stability of long-term His-bundle pacing are yet unsolved. We used six adult beagles, in which a screw-in lead was anchored in the His-bundle region for observation of the pacing conditions and histopathologic changes of the conduction system over the course of 2 months. In the results, a satisfactory fixation was obtained using a conventional screw-in lead and no histological influence on the conduction system was observed. The pacing threshold at the time of implantation was 1.15 ± 0.69V (3.23 ± 3.08 mA) in the pulse width of 0.5 ms. R wave amplitude, the impedance and slew rate were 7.28 ± 2.04 mV, 409 ± 102 Ohm, and 0.65 ± 0.41 V/s, respectively. Two months later, these parameters changed to 2.83 ± 1.06 V (10.4 ± 5.71 mA), 5.63 ± 1.62 mV, 310 ± 71.3 Ohm, and 0.49 ± 0.22 V/s, respectively. These results suggest the feasibility of clinical application of permanent His-bundle pacing.     

Idiopathic Ventricular Arrhythmias Originating from the Papillary Muscles in the Left Ventricle: Prevalence, Electrocardiographic and Electrophysiological Characteristics, and Results of the Radiofrequency Catheter Ablation

Idiopathic VAs Originating from the LV Papillary Muscles.   Introduction: Idiopathic ventricular arrhythmias (VAs) can originate from the left ventricular (LV) papillary muscles (PAMs). This study investigated the prevalence, electrocardiographic and electrophysiological characteristics, and results of catheter ablation of these VAs, and compared them with other LV VAs.
Methods and Results: We studied 71 patients with VAs originating from the LV anterolateral and posteroseptal regions among 159 patients undergoing successful catheter ablation of idiopathic LV VAs. PAM VAs were uncommon, rare in a sustained form, and more common from the posterior papillary muscle (PPM) than anterior papillary muscle (APM). A younger age was a good predictor for differentiating left posterior fascicular VAs from PPM VAs. There were several electrocardiographic features that accurately differentiated PAM and LV fascicular VAs from mitral annular VAs. However, an R/S ratio ≤1 in lead V6 in the LV anterolateral region and a QRS duration >160 ms in the LV posteroseptal region were the only reliable predictors for differentiating PAM VAs from LV fascicular VAs. A sharp ventricular prepotential was recorded at the successful ablation site during 42% of the PAM VAs. Radiofrequency current with an irrigated or conventional 8-mm tip ablation catheter was required to achieve a lasting ablation of the PAM VA origins whereas that with a nonirrigated 4-mm tip ablation catheter produced excellent results in LV fascicular and mitral annular VAs.
Conclusions: There are differences in the electrocardiographic and electrophysiological features among VAs originating from these regions that are helpful for their diagnosis and effective catheter ablation. (J Cardiovasc Electrophysiol, Vol. 21, pp. 62–69, January 2010)     

SCREENING FOR AUTOSOMAL ABERRATIONS

Abstract. A method of screening for autosomal aberrations is important as an indication for chromosome analysis such as that used in sex-chromatin examination for sex chromosome aberrations. In our clinic, malformed patients with mental retardation and abnormal dermatoglyphic patterns are strong suspects for autosomal aberrations. Abnormal dermatoglyphic patterns are separated into two categories: (1) Absolutely abnormal—radial loop of 1st finger, radial loop of 4th finger, radial loop of 5th finger, arch over 6 fingers, arch tibial, loop tibial, and arch fibular; (2) Borderline abnormalities—high axial triradius (t' and t"), simian crease, interdigital loop, and single crease of 5th finger. Of 416 cases showing malformation, retardation, and abnormal dermatoglyphics, 308 had autosomal aberrations, while 108 had normal karyotypes. In the group with autosomal aberrations, 279 patients (90.6%) had absolutely abnormal dermatoglyphics. In the group with normal karyotypes only 8 patients (7.4%) had absolutely normal dermatoglyphics, while most had abnormal dermatoglyphics in the borderline category. These clinical manifestations: absolutely abnormal dermatoglyphics, mental retardation, and malformations are therefore very useful in screening for autosomal aberrations.     

Biocompatibility of Heparin-Coated Membrane Oxygenator During Cardiopulmonary Bypass

Abstract: The biocompatibility of the cardiopulmonary bypass (CPB) circuit, in which an oxygenator is solely heparinized, was assessed by systemic inflammatory reactions as an indicator during CPB. Fourteen patients, 11 males and 3 females, underwent coronary artery bypass surgery and were randomly divided into 2 groups of 7 patients each. For the heparin–coated oxygenator group (Group H), a heparin–coated membrane oxygenator was used in the CPB circuit, and in the control (Group C) an uncoated membrane oxygenator was employed. Systemic inflammatory reactions, such as platelet activation, prostaglandin production, complement activation, and activated granulocyte released substance, were measured prior to, during, and 6 h after CPB. The number of platelets decreased after protamine administration in both groups (14. 5 ±4. 7 times 10⁴/μl in Group H and 13. 8 ± 8. 7 times 10⁴/μd in Group C) and returned to baseline levels in Group H while it remained decreased in Group C at 6 h after CPB. The platelet factor 4 level was significantly lower in Group H (181 ± 40 ng/ml) than in Group C (297 ±131 ng/ml) after protamine administration. Thromboxane–B₂ (TXB₂) rose during CPB in both groups; however, there were significantly different levels of TXB₂ between the 2 groups at 60 min after CPB (293±258 pg/ml in Group H versus 408 ± 120 pg/ml in Group C) and after protamine administration (259 ± 122 pg/ml in Group H versus 709 ± 418 pg/ml in Group C). Plasma concentrations of granulocyte elastase were significantly lower in Group H at 30, 60 and 90 min, immediately after, and post–CPB than those of Group C. Although the oxygenator was solely heparinized in the CPB circuit, it was sufficiently effective to reduce inflammatory reactions during coronary artery bypass operation, and the heparin–coated surface seems to be more endothelium–like.