Vibrations of probe used for the defect detection of helical heating tubes in a fast breeder reactor: Part 1. Experimental results by using mock-up

This paper deals with the vibration and the sensor signal noise of the eddy current testing (ECT) probe used for a defect detection of helical heating tubes in the fast breeder reactor “Monju”, developed in Japan. ECT probes are used for the detection of defects in a heating tube. The heating tube is composed of a helical tube and a straight tube because of their advantages of thermal efficiency and saving space. No vibrations of the ECT probe have been generated in usual straight heating tubes. However, vibrations of the ECT probe in the helical tube cause some noise and decrease the sensitivity of the ECT probe. The experiment was performed using a mock-up, and the noise characteristics of an ECT sensor mounted in an ECT probe were examined. The experimental results showed that the sensor signal noise during the insertion process of the ECT probe was higher than that of the return process, and vibrations of the insertion process had a certain emerging frequency. Attaching the long and flexible guide probe to the top of the ECT probe was an effective countermeasure against sensor signal noise.     

Expression of type IV collagen in the developing human kidney

The distribution of alpha1-6 chains of type IV collagen (alpha1-6(IV)) in human fetal kidneys was examined by indirect immunofluorescence. By 11 weeks of gestation, alpha1, 2, 3, 4, and 6(IV) were already present, but alpha5(IV) appeared relatively late, at 21 weeks. Alpha1(IV) and alpha2(IV) were present in all basement membranes, alpha3(IV) and alpha4(IV) were restricted to the glomerular basement membrane and parts of the tubular basement membrane. Alpha5(IV) was distributed in the glomerular basement membrane, Bowman's capsule, and parts of the tubular basement membrane. Alpha6(IV) was present in the Bowman's capsule, parts of the tubular basement membrane, and occurred in parts of the glomerular basement membrane at the early capillary loop stage, but disappeared during the later capillary loop stage.     

Intraoperative transient incomplete left bundle branch block in a patient with left axis deviation in pre-anesthetic electrocardiogram

We encountered a case of transient incomplete left bundle branch block (TILBBB) during standard mastectomy under general anesthesia. The patient was a 40 year-old female (70 kg, 164 cm) without any abnormalities on preanesthetic examinations except -61 degrees left axis deviation in exercise electrocardiogram. Adriamycin 20 mg was administered preoperatively. After the skin incision, heart rate increased from 104 min-1 to 130 min-1 and the cardiac axis gradually rotated leftward with increasing Q wave depth on leads I and aVL. We diagnosed this as blockade of the anterior branch in the left bundle branch. After the administration of fentanyl (0.2 mg) and sevoflurane (3%), the heart rate decreased to 105 min-1 and the electrocardiogram returned to the initial wave form. This anesthetic course indicated that adriamycin had slightly damaged the cardiac muscle and inadequate anesthesia had caused tachycardia and transient left bundle branch block. Left axis deviation on preoperative exercise electrocardiogram suggests that the left bundle branch can easily be blocked with an increasing heart rate. Adequate depth of anesthesia would have prevented the increase in heart rate and abnormality in the cardiac conduction process.     

Isothermal Adsorption Behavior of Cesium Ions in a Novel Chitosan‐Prussian Blue‐Based Membrane

Prussian blue (PB) particles were successfully immobilized on a novel chitosan membrane. Morphological observations confirmed that the PB particles were densely immobilized within the membrane. From isothermal adsorption analysis, an increase in the mass fraction of PB contained within the membrane (MF_PB) assisted the improvement of the initial adsorption rate as well as the adsorption uptake of cesium ions. A high MF_PB led to a decrease in the effective diffusion coefficient of cesium ions in the membrane. Adsorption equilibrium data were found in good agreement with the Langmuir model. The maximum adsorption capacity of the membrane immobilizing PB as well as the adsorption constant in the Langmuir model increased with higher MF_PB.     

Congenital tracheoesophageal fistula with symptoms commencing at the onset of trauma: report of a case

Congenital tracheoesophageal fistula without atresia can persist and remain undetected without symptoms until adulthood. We have recently encountered such a rare case and also conducted a review of the literature. Symptoms are commonly present during infancy, but occasionally patients do not develop symptoms until adulthood. In this case, it is suggested that the symptoms commenced after the redundant mucosal flap or membrane was broken due to a trauma to the chest.     

Gonadotropin-releasing hormone-induced elevation of serum hCG in choriocarcinoma: a case report

OBJECTIVE: To determine the effect of low doses of linoleic acid and calcium on prostaglandin (PG) levels and the efficacy of this treatment in the prevention of preeclampsia. METHODS: In a randomized, double-blind, placebo-controlled study we treated 86 primigravidas with risk factors for preeclampsia (high biopsychosocial risk [above 3 points], positive roll-over test, and high mean blood pressure [above 85 mmHg)] with daily doses of either 450 mg linoleic acid and 600 mg calcium (n=43) or 450 mg starch and 600 mg lactose placebo (n=43) during the third trimester of pregnancy. RESULTS: Four women in the experimental group (9.3%) developed preeclampsia compared with 16 (37.2%) controls (relative risk 0.25, 95% confidence interval 0.09, 0.69, P < .001). The median serum levels of PGE2 after 4 weeks of treatment increased by 106% in the experimental group (P=.03) and decreased by 33% in the control group (P=.02). The median ratio between thromboxane B2 and PGE2 decreased by 40% in the experimental group (P=.02) and increased by 18% in the control group (P=.14). No significant differences were observed in the median ratio between thromboxane B2 and 6-keto PGF1alpha in either group. No serious maternal or neonatal side effects of treatment occurred in either group. CONCLUSION: The administration of low daily doses of linoleic acid and calcium during the third trimester of pregnancy reduced the incidence of preeclampsia significantly in women at high risk, possibly by correcting the PGE2 levels.     

Kinetic studies on bovine cytochrome p45011 beta catalyzing successive reactions from deoxycorticosterone to aldosterone

The reactions for the synthesis of aldosterone from deoxycorticosterone were investigated kinetically in the membrane-reconstituted system with bovine cytochrome P45011 beta at 37 degrees C. Reaction rapid-quenching experiments for the metabolism of deoxycorticosterone by P45011 beta showed that aldosterone was produced via corticosterone, not via 18-hydroxydeoxycorticosterone. The kinetic analysis revealed that aldosterone was formed successively from fractions of intermediate metabolites which did not dissociate from P45011 beta. The rate of each reaction step in the successive reactions was estimated from the combination of results of the rapid-quenching experiments and the metabolism of deoxycorticosterone in the presence of an excess amount of substrate, in which the dissociation of final product, aldosterone, from the enzyme was the slowest step in the synthesis from deoxycorticosterone. Under steady-state reaction conditions, the interaction of P45011 beta with P450scc stimulates the production of corticosterone from deoxycorticosterone by about 10-fold but inhibits further reactions from corticosterone. The rapid-quenching experiments showed, however, that the rate constant for the 11 beta-hydroxylation of deoxycorticosterone for corticosterone production in the presence of P450scc was almost the same as that without P450scc. The interaction of P45011 beta with P450scc in the reaction system for deoxycorticosterone metabolism was found to slow the rate of the subsequent 18-hydroxylation of the produced corticosterone and to accelerate the dissociation of the corticosterone from P45011 beta, which stimulated the corticosterone production and inhibited the further reaction for aldosterone synthesis in the steady-state reaction.     

The effects of genetic polymorphisms of CYP2C9 and CYP2C19 on phenytoin metabolism in Japanese adult patients with epilepsy: studies in stereoselective hydroxylation and population pharmacokinetics

PURPOSE: The aim of this study was to clarify the effects of genetic polymorphisms of cytochrome P450 (CYP) 2C9 and 2C19 on the metabolism of phenytoin (PHT). In addition, a population pharmacokinetic analysis was performed. METHODS: The genotype of CYP2C9 (Arg144/Cys, Ile359/Leu) and CYP2C19(*1, *2 or *3) in 134 Japanese adult patients with epilepsy treated with PHT were determined, and their serum concentrations of 5-(4-hydroxyphenyl)-5-phenylhydantoin (p-HPPH) enantiomers, being major metabolites of PHT, were measured. A population pharmacokinetic analysis (NONMEM analysis) was performed to evaluate whether genetic polymorphism of CYP2C9/19 affects the clinical use of PHT by using the 336 dose-serum concentration data. RESULTS: The mean maximal elimination rate (Vmax) was 42% lower in the heterozygote for Leu359 allele in CYP2C9, and the mean Michaelis-Menten constants (Km) in the heterozygous extensive metabolizers and the poor metabolizers of CYP2C19 were 22 and 54%, respectively, higher than those without the mutations in CYP2C9/19 genes. (R)- and (S)-p-HPPH/PHT ratios were lower in patients with mutations in CYP2C9 or CYP2C19 gene than those in patients without mutations. CONCLUSIONS: Although the hydroxylation capacity of PHT was impaired with mutations of CYP2C9/19, the impairment was greater for CYP2C9. In view of the clinical use of PHT, two important conclusions were derived from this population study. First, the serum PHT concentration in patients with the Leu359 allele in CYP2C9 would increase dramatically even at lower daily doses. Second, the patients with CYP2C19 mutations should be treated carefully at higher daily doses of PHT.