Preparation of polymer-supported amino acid

Summary Insoluble polymer-supported amino acids have been synthesized by simple one-pot synthesis. Amino acids were solubilized in organic solvent by trimethylsilylation. Solubilized amino acids (L-Tyr, L-Ser, D-HPG, L-Cys) having functional groups such as OH or SH were easily attached to crosslinked polystyrene beads through benzyl ether or thioether linkage. Other amino acids without extra functional groups could be attached to the polymer through benzyl amine linkage.     

Efficacy of epidural analgesia in minimally invasive direct coronary artery bypass surgery

Minimally invasive direct coronary artery bypass surgery (MIDCAB), coronary bypass grafting with small thoracotomy using no cardiopulmonary bypass (CPB), became popular recently. To attenuate perioperative stress-response, we used epidural analgesia (EPI) with general anesthesia for MIDCAB operation. In this study, we compared retrospectively 11 cases of MIDCAB managed with EPI [ED (+)], and 14 cases of MIDCAB anesthetized without using EPI [ED (-)], concerning extubation time, ICU stay, hospital stay and perioperative complications. The mean time from cessation of general anesthesia to extubation was significantly shorter in ED (+) patients (0.5 hours) when compared to ED (-) patients (18.2 hours). Mean periods of ICU stay and hospital stay were, also, shorter in ED (+) patients (2.1 days, 30.5 days, respectively) when compared to ED (-) (4.3 days, 45.1 days, respectively) patients. We experienced ventricular tachycardia in three patients of ED (-). No major complication occurred in ED (+) patients. These results suggest that EPI shortened extubation time, ICU and hospital stay for MIDCAB patients.     

Thermodynamics of lead and bismuth in CaO–CaF2 melts

In order to understand a new refining process for removing tramp elements from alloy steels under strongly reducing conditions, the authors previously reported the thermodynamic behaviour of P, Sn, Sb, As and Cu in CaO–CaF₂ melts. In this investigation, the thermodynamic behaviour of Pb and Bi in CaO–CaF₂ melts under oxygen partial pressures from 10^?16 to 10^?20 atm was studied at temperatures ranging from 1360 to 1550°C, using a similar technique. It was shown that Pb and Bi exist in slag mainly as Ca₂Pb and Ca_1.5Bi, respectively, under very low oxygen partial pressure although a part of Pb is soluble in slags as metal. The obtained results were extrapolated to lower oxygen partial pressures to investigate the possibility of removing these tramp elements from molten iron, causing Bi to be removed from molten iron below an oxygen partial pressure of 10^?23 atm, whereas Pb is removed under higher oxygen partial pressures.     

Colour and Constitution of 1,4-Naphthoquinonoid Dyes - Modified PPP MO Calculations and Substituent Effects

Calculation of the n-electron excitation energies of naphthoquinonoid dyes has been carried out by means of the Pariser—Parr—Pople (PPP) method using the variable, β,γ-approximation. A good linear correlation between the observed and calculated values for the first π-π* excitation was found for a new series of naphthoquinonoid dyes. The effect of substituents on the colour of different dyes was studied on the basis of these calculated results, i.e. HOMO—LUMO energy levels and π-electron-density changes accompanying the excitation. The intramolecular charge-transfer character of the π-π* transition was shown to be the same as occurs in some anthraquinonoid dyes.     

Simple,Mild, and Practical Esterification,Thioesterification, and Amide Formation Utilizing p‐Toluenesulfonyl Chloride and N‐Methylimidazole

We have developed an efficient method for the esterification or thioesterification of equimolar amounts of carboxylic acids and alcohols or thiols using a novel reagent, p‐toluenesulfonyl chloride (TsCl) together with N‐methylimidazole. The present method is simple, mild, and reactive, uses readily available and economical reagents. The choice of amine is critical for the present method. The amine, N‐methylimidazole, has two roles: (i) as an HCl scavenger for the initial smooth generation of mixed anhydrides between carboxylic acids and TsCl and (ii) successive formation of highly reactive ammonium intermediates from mixed anhydrides. This method could be applied to various types of carboxylic acids, alcohols, and thiols: a) several functionalities were tolerated; b) two N‐Cbz amino acids were smoothly esterified without racemization; and c) the labile 1β‐methylcarbapenem key intermediate and a pyrethroid insecticide, prallethrin, were successfully prepared. The related amide formation between carboxylic acids and primary or secondary amines was also performed. The proposed reaction mechanism involves a novel method for producing the reactive acylammonium intermediates. The production of these intermediates was rationally supported by a careful ¹H NMR monitoring study.     

Three cases of irritable bowel syndrome treated with stellate ganglion block]

We examined three patients with irritable bowel syndrome (IBS) who did not respond to drug therapy and who were treated by stellate ganglion block (SGB) alone. The clinical symptoms improved by the SGB in all these three patients. There was no recurrence. The pathophysiological mechanism of this disease and the therapeutic efficacy of SGB should be elucidated with respect to the autonomic nervous, endocrine and immune systems. These results suggest that SGB therapy is effective for IBS, a typical psychosomatic disease.     

Genetic polymorphism of the 3' VNTR region of the human dopaminergic function gene DAT1 (human dopamine transporter gene) in the Mongolian population

The hypervariable region of the dopamine transporter gene (DAT1) was amplified from samples in the Mongolian population. This region includes a variable number of tandem repeats of a 40-bp core unit in the 3' untranslated region of DAT1. Vandenbergh et al. (1992) reported variability in the number of repeats of this 3' flanking region ranging from 3 to 11 times in white and black populations. We examined polymorphism at the DAT1 locus in 78 native Mongolian subjects. We found alleles with 7 to 13 repeats, which is different from the findings of Vandenbergh et al. (1992). The allele distribution of the Mongolian population is similar to that in the Japanese population, reported previously by Nakatome et al. (1995). Chi-square analysis showed a significant lack of homogeneity between our findings in Mongolian subjects and those reported previously in white and black populations. The DAT1 locus was estimated to have a heterozygosity index of 14.1%, and the polymorphic information content was calculated to be 0.16.     

Assessment of adrenergic neuron function altered with progression of heart failure

We used MIBG to evaluate cardiac adrenergic neuron integrity and function in congestive heart failure. METHODS: Rats were treated with adriamycin (2 mg/kg, s.c.) once a week for 7, 8 and 9 wk. In analyzing cardiac adrenergic neuron function, we assessed alterations of uptake-1, exocytotic release and nonexocytotic metabolic release in relation to progression of heart failure. RESULTS: LVEF progressively decreased. Cardiac MIBG accumulation (4 hr postinjection) decreased to 53% of control at 7 wk and markedly decreased to 14% of control at 9 wk, accompanied by massive pleural effusions. Reduction of MIBG accumulation in the lung and spleen, which are adrenergic-rich organs similar to the heart, were less pronounced compared to reduction in the heart. There was no difference in cardiac uptake of 3H-norepinephrine between the control and 8-wk groups. Cardiac uptake of 3H-norepinephrine decreased 91.0% in the control and 90.8% in the 8 wk group by pretreatment of desipramine, indicating no difference in the uptake-1 component. CONCLUSION: Congestive heart failure due to adriamycin cardiomyopathy progressively accelerates exocytotic release of norepinephrine predominantly from cardiac adrenergic neurons, but neuronal uptake function is not disturbed so long as heart failure is not advanced. In the advanced stage, nonexocytotic metabolic release is induced specifically in cardiac adrenergic neurons due to energy depletion and norepinephrine release markedly increases.     

Survey on the distribution of the gene 4 alleles of human rotaviruses by polymerase chain reaction

The presence of six gene 4 alleles (or VP4 genotypes) in human rotaviruses has been recognized. Using 16 representative cultivable human rotavirus strains, we confirmed the specificity of VP4 genotyping by polymerase chain reaction (PCR) using the nested oligonucleotides specific to each of the four representative gene 4 alleles. Using the PCR, we surveyed the gene 4 alleles of 199 human rotaviruses in stools collected in Japan and Thailand. Strains with the gene 4 allele, corresponding to P1A serotype, were shown to be the most prevalent, but two strains with P2 gene 4 allele and one strain with P3 gene 4 allele were detected in Thailand and in Japan, respectively.