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Biomedical subjects

Y Asano

Publications and source records attributed to Y Asano.

At least 451 records · Page 25Linked to original sources
PubMed1993

[Detection of antibody to varicella zoster virus by immune adherence hemagglutination].

Anti varicella-zoster virus (VZV) antibodies were detected by an immune adherence hemagglutination (IAHA) test, and were compared with the CF test, IFA test and ELISA test, respectively. Type O, Rh-positive RBC for IAHA was obtained from five healthy volunteers. All five RBCs had sufficient sensitivity as the indicator cell. Optimum incubation temperature was 37 degrees C in the serum and in the complement. The complement was obtained from guinea pig sera, and the most suitable concentration was 1;100. The convalescent VZV antibody titers were similar to the values obtained from any of the methods previously mentioned. However, mean titers measured by CF were about two-to fourfold lower than in the values of IAHA. Seroconversion rates of the live VZV vaccine, as detected by CF and IFA were relatively low (CF; 76%, IFA; 56%). In contrast, those obtained from ELISA and IAHA showed perfectly (100%). These results indicate that IAHA has sufficient sensitivity and specificity in the detection of VZV antibodies. In addition, the IAHA test is thought to be a rapid and easy test to perform in ordinary laboratories.

Antibodies, Viral↗
PubMed1993

Microbial production of D-malate from maleate.

To produce D-malate from maleate by a microbial reaction, we screened a number of maleate-utilizing microorganisms for enzyme activity by an intact cell system. The strain which showed the best productivity among the 440 strains tested was identified taxonomically as Arthrobacter sp. strain MCI2612. The optical purity of the malate produced by this strain was 100% D type. The culture and reaction conditions for the production were studied for this strain. Addition of amino acids such as L-proline, L-histidine, and L-arginine to the culture medium promoted the formation of reaction activity as well as cell growth. Under optimum conditions, 87 g of D-malate per liter was produced in 20 h. The yield was 72 mol%.

Arthrobacter↗
PubMed1993

Effect of oral acyclovir against primary and secondary viraemia in incubation period of varicella.

The effect of oral acyclovir (approximately 40 mg/kg daily in four divided doses) against primary and secondary viraemia of varicella zoster virus (VZV) was examined in 27 children susceptible to VZV who were exposed to the virus in their families and their clinical features were compared with those of 19 non-treated subjects. The infection was confirmed by a fluorescent antibody to membrane antigen assay in 11 (85%) of 13 children who received acyclovir for the first seven days after exposure to VZV and in 11 (79%) of 14 who received acyclovir for the next seven days. The geometric mean antibody titre of the former group was significantly higher than that of the latter group. Varicella developed in 10 (91%) and was subclinical in one (9%) in the former group, whereas a very mild disease occurred in three (27%) and was subclinical in eight (73%) in the latter group. The severity of varicella was significantly greater in the former group than that in the latter group. On the other hand, all of the control group developed typical varicella and their clinical features were more severe than those of the acyclovir administered group. These data indicate that oral acyclovir more effectively inhibits replication of VZV in secondary viraemia than that of the primary viraemia.

Acyclovir↗
PubMed1993

Functional evidence for an apical V1 receptor in rabbit cortical collecting duct.

In the rabbit cortical collecting duct (CCD) perfused in vitro, we recently found that luminal arginine vasopressin (AVP) hyperpolarizes the transepithelial voltage (Vt) and inhibits the hydrosmotic effect of basolateral AVP. The present study was undertaken to characterize the apical receptor of the CCD for AVP. In contrast to AVP, luminal application of 1-desamino-8-D-arginine vasopressin (DDAVP), a V2 agonist, did not significantly induce hyperpolarization. Luminal oxytocin (OXT) hyperpolarized Vt, interfering with the effect of superimposed luminal AVP, whereas [Thr4,Gly7]OXT, an OXT agonist, did not reproduce the effect of OXT. The effects of luminal AVP and OXT were abolished by [d(CH2)5,Tyr(Me)]-AVP, a V1 antagonist. Finally, luminal applications of AVP metabolite neuropeptides, pGlu-Asn-Cys(Cys)-Pro-Arg and pGlu-Asn-Cys(Cys)-Pro-Arg-Gly-NH2, were without effect on Vt. These data suggest that luminal AVP induces hyperpolarization through an apical V1 receptor but not through a V2 receptor or an OXT receptor.

Amino Acid Sequence↗
PubMed1993

Thyroid hormone stimulates Na(+)-K(+)-ATPase gene expression in cultured rat mesangial cells.

Thyroid hormone 3,3',5-triiodothyronine (T3) is an important regulator of Na(+)-K(+)-adenosinetriphosphatase (Na(+)-K(+)-ATPase) activity in a variety of mammalian target tissues. In the present study, we examined the expression of Na(+)-K(+)-ATPase alpha- and beta-subunit mRNAs by T3 in cultured rat mesangial cells. Northern blot analysis of total RNA isolated from cultured rat mesangial cells revealed the expression of mRNAs encoding Na(+)-K(+)-ATPase alpha 1- and beta 1-subunits; mRNAs encoding alpha 2- and alpha 3-subunits were undetectable. Exposure of mesangial cells to T3 (10(-8) M) caused a threefold increase in the alpha 1-mRNA expression, which was first detected at 6 h and sustained for at least 48 h. The beta 1-mRNA expression was gradually increased by T3, with a maximum fourfold elevation at 48 h. The 50% effective concentration (EC50) for the alpha 1- and beta 1-mRNA induction by T3 was approximately 10(-10) M. The half-life of alpha 1-mRNA analyzed by actinomycin D chase was approximately 3 h and was not affected by T3. The augmented alpha 1-mRNA expression by T3 was associated with a 2.4-fold increase in the alpha 1-subunit protein accumulation and a 1.6-fold increase in Na(+)-K(+)-ATPase activity. These data suggest that thyroid hormone stimulates Na(+)-K(+)-ATPase gene expression, protein accumulation, and enzyme activity in rat mesangial cells.

Animals↗
PubMed1993

Electrical properties of the rabbit cortical collecting duct from obstructed and contralateral kidneys after unilateral ureteral obstruction.

Electrophysiological techniques were used to determine the electrical properties of the collecting duct (CD) cell in the isolated cortical collecting duct from obstructed (UUOOK) and contralateral (UUOCK) kidneys in rabbits 24 h after unilateral ureteral obstruction (UUO); results were compared with those from sham-operated kidneys. The lumen-negative transepithelial voltage and the basolateral membrane voltage (VB) were decreased in the UUOOK, and increased in the UUOCK. The transepithelial conductance (GT) was decreased in parallel with an increase in the fractional apical membrane resistance (fRA) and a decrease in apical membrane conductance in the UUOOK. By contrast, the GT was increased in parallel with increases in apical and basolateral membrane conductances in the UUOCK. The amiloride-sensitive changes in apical membrane voltage (VA), GT and fRA were lower in the UUOOK, but greater in the UUOCK. The changes in VA and GT upon raising the perfusate K+ concentration and upon addition of luminal Ba2+ were decreased in the UUOOK, and increased in the UUOCK. Addition of ouabain to the bath resulted in a smaller depolarization of VB in the UUOOK, but in a greater depolarization in the UUOCK. Upon lowering bath Cl-, the change in basolateral membrane electromotive force (delta EMF) was increased in the UUOOK, and decreased in the UUOCK. Reversely, upon raising bath K+, the delta EMF was decreased in the UUOOK, and increased in the UUOCK. We conclude: (a) the conductances of Na+ and K+ in the apical membrane, and active Na(+)-K+ pump activity and relative K+ conductance in the basolateral membrane are decreased in the UUOOK, and increased in the UUOCK; (b) the relative basolateral membrane Cl- conductance was increased in the UUOOK, and decreased in the UUOCK.

Amiloride↗
PubMed1993

The body surface QRST isointegral maps in infants with right ventricular overload.

Electrocardiographic criteria for right ventricular (RV) hypertrophy in infants generally exhibit low sensitivity in terms of diagnostic accuracy. We studied the QRST isointegral map (QRST-Imap) of body surface potential distribution for the diagnosis of RV overload in patients less than 2 years old. Patients with atrial septal defect (ASD), pulmonary stenosis (PS) and tetralogy of Fallot (TOF) were examined (RV overload group) and the findings of their QRST-Imaps were compared to those of age-matched healthy infants (NOR). QRST-Imaps in RV overload showed abnormal findings, with two maxima or a rightward shift of the maximum with increased amplitude, in contrast to one maximum at the left anterior chest with a single dipole pattern in the NOR group. ASD patients had two maxima with a decreased integral value between them. In PS, two maxima were also observed, with increased integral values of the right maximum as the RV systolic pressure was elevated. TOF patients showed a single maximum shifted to the anterior median line with increased amplitude. These results indicate that the findings of QRST-Imaps are of value in detecting the presence and pattern of RV overload in infants.

Electrocardiography↗
PubMed1993

Use of biplane transesophageal echocardiographic guide in radiofrequency catheter ablation of Wolff-Parkinson-White syndrome with left side Kent bundle.

We report 2 patients with Wolff-parkinson-White Syndrome, who underwent radiofrequency (RF) catheter ablation under observation by biplane transesophageal echocardiography. One of the patients had Kent bundle in the lateral wall of the left ventricle, and the tip of the catheter could be easily confirmed with transverse views. Since perforation was observed where the valve was attached to the posterior leaflet of the mitral valve during the 39th administration of RF energy, ablation was discontinued. The other patient had Kent bundle in the posterior septum of the left ventricle. The tip of the catheter could be easily confirmed with sagittal views. Ablation was successful after the 4th administration of RF energy, but particulate contrast echoes appeared from the site of the tip of the electrode which had been used for ablation during the 4th RF delivery. When the delivery of RF energy was discontinued, the contrast echo disappeared, and a thrombus was found at the tip of the removed catheter. TEE in RF catheter ablation was helpful for confirming the site of the tip of the catheter and for early detection of complications.

Adult↗
PubMed1993

Retinal dopamine and its metabolite contents in zitter rats and spontaneously epileptic rats.

In order to investigate the relationship between visual dysfunction and retinal DA metabolism in zitter rats and spontaneously epileptic rats (SER), we measured the amounts of retinal dopamine (DA) and its metabolites, 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillate (HVA). DA, DOPAC and HVA contents were markedly decreased in zitter rats as compared with the controls, Kyo:Wistar or Sprague-Dawley rats. In contrast, in SER, retinal DA and its metabolite contents were not significantly different from those of Kyo:Wistar rats. SER showed higher levels of DA and its metabolites in comparison with Sprague-Dawley rats. Thus, it is suggested that the debilitation of retinal DA synthesis is at least partly related to the visual dysfunction observed in zitter rats, but not that of SER.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1993

Both beta-1 and beta-2 adrenoceptors are coupled to the cyclic AMP system in connecting tubules of rabbit nephron.

The connecting tubule (CNT), a segment interposed between distal convoluted tubules and collecting ducts, is a well defined segment in the rabbit nephron and have been shown to contain adenylate cyclase activity which is responsive to the beta agonist isoproterenol (ISO) and the nonselective beta blocker propranolol. We examined whether ISO also increased cAMP levels in the intact microdissected CNT in the presence of 1-methyl-3-isobutyl-xanthine and, in particular, which subtype of beta adrenoceptors was stimulated. ISO increased cAMP contents in a dose-dependent way (ED50 approximately equal to 10(-7) M) and the maximal stimulation was achieved at 1 microM ISO. Norepinephrine also elevated cAMP content in the CNT to the same extent as ISO. The increase in cAMP stimulated by ISO and norepinephrine was inhibited by 1 microM propranolol but not by 1 microM phenoxybenzamine. ISO-induced cAMP increased was blocked by the beta-1 antagonist metoprolol and also by the beta-2 antagonist ICI-118551 independently in a dose-dependent manner, and maximal inhibition was observed at 1 microM of both antagonists. These results indicate that both beta-1 and beta-2adrenoceptors appear to be located in the rabbit CNT and both can be positively coupled to adenylate cyclase to generate cAMP accumulation.

Adrenergic alpha-Antagonists↗
PubMed1993

[Cranioplasty using cryopreserved autogenous bone].

Various materials and methods can be used for cranioplasty following external decompression craniotomy. We generally use cryopreserved autogenous bone for cranioplasty following external decompression. We assessed several factors, including histological changes in the stored bone, postoperative skull X-ray changes, postoperative changes in skull morphology, and the incidence of postoperative infections. The purpose of this study was determined if our materials and preservation methods were appropriate. The subjects were 110 patients who underwent cranioplasty using cryopreserved autogenous bone following external decompression at our hospital. They were followed up for at least one year. Bone fragments removed at the time of external decompression were stored at -40 degrees C an ultra-low temperature freezer and returned to room temperature before using them for cranioplasty. Follow-up skull x-ray films were obtained for 1-10 years postoperatively. Almost all of the 46 patients showed bone union at least one year after cranioplasty, but seven patients (15%) had marked bone resorption and bone atrophy after 3 years or longer. Five of these patients had a concomitant ventriculo-peritoneal shunt. Two of them developed collapse of the skull due to bone resorption, and this was considered to have been influenced by the shunt. Epidural empyema occurred postoperatively in five patients (4.5%), and staphylococci were the causative organisms in all five cases. The infections were completely cured by removal of the bone graft, debridement of the wound, and epidural drainage. Cranioplasty following external decompression craniotomy using cryopreserved autogenous bone fragments is a simple procedure, and the materials are inexpensive. Many of our patients who underwent cranioplasty using cryopreserved autogenous bone experienced no serious complications.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Clinical features of primary human herpesvirus-6 infection in an infant with acute lymphoblastic leukemia.

PURPOSE: The primary infection with human herpesvirus-6 developed concurrently with diagnosis of acute lymphoblastic leukemia and initiation of intensive chemotherapy for the disease in a 4-month-old girl. RESULTS: Prolonged viremia persisted for 7 days in the presence of neutralizing antibodies, and clinical features such as prolonged febrile and diarrheal period, no appearance of skin rash, and marked bulging fontanelle for 7 days in the absence of the virus DNA in spinal fluid may suggest an atypical clinical course of exanthem subitum and an unusual viral replication in immunocompromised condition.

DNA, Viral↗
PubMed1993

Effect of the angiotensin converting enzyme inhibitor, captopril, on proteinuria in chronic glomerular disease.

The antiproteinuric effect of the angiotensin-I-converting enzyme inhibitor, captopril, was studied in 14 patients (10 men and 4 women, age range of 24 to 60 years) with chronic glomerulonephritis in whom IgA nephritis had been confirmed by renal biopsy. Eight of the 14 patients had received antihypertensive drugs such as calcium channel blockers, diuretics or beta-blockers. Captopril was added to these regimens at 25 mg twice daily in 3 patients, and 37.5 mg in 11 patients. Proteinuria decreased from 2.55 +/- 0.48 g/day to 1.58 +/- 0.35 g/day within three months after the start of administration. In 4 patients (28.6%), the extent of reduction was over 50%, and in 8 patients (57.1%), over 25%. Blood pressure, creatinine clearance and serum creatinine were not changed significantly. There was a positive linear correlation between the extent of reduction of proteinuria and the increase in plasma renin activity (r = 0.93, p < 0.001). We conclude that captopril reduces proteinuria in some patients with IgA nephritis whose plasma renin activity responds to the drug.

Adult↗
PubMed1993

Effects of long-term, low-fat diet on plasma apo E in familial LCAT deficiency.

To study the metabolic abnormalities in familial lecithin-cholesterol acyltransferase (LCAT) deficiency, the effects of a long-term, low-fat diet and LCAT replacement therapy on plasma lipids and apolipoproteins were investigated in a patient with LCAT deficiency. The patient had elevated triglycerides (TG, 543.7 mg/dl) and phospholipids (PL, 350.3 mg/dl) and normal total cholesterol (TC, 206.9 mg/dl). Change to a low-fat diet reduced TC and TG by 20% and 75%, respectively. These reductions occurred mainly in the d < 1.006 fraction. At baseline, the patient had normal apolipoprotein B (apo B), low apolipoprotein A-I (apoA-I) and apolipoprotein A-II (apoA-II) and elevated apolipoprotein E (apo E). Long-term treatment with a low-fat diet increased plasma apoA-I and decreased apo E. However, urinary protein excretion did not change throughout the observed period. LCAT replacement with fresh frozen plasma (FFP) after the low-fat diet further reduced plasma apo E to the normal range. These results indicate that the elevated plasma apo E in LCAT deficiency was related not only to the lack of LCAT in the plasma, but also to fat intake. A low-fat diet may be effective in correcting lipid abnormalities. Moreover, plasma apo E may be a good indicator of the efficacy of diet therapy.

Apolipoproteins E↗
PubMed1993

The antiseptic effect of a quick drying rubbing type povidone-iodine alcoholic disinfectant solution.

A quick drying rubbing type disinfectant of non-water non-towel type is an antiseptic method suitable for practical use in intensive care units where emergency situations are common. We determined the antiseptic efficacy and safety of a quick drying rubbing type povidone-iodine alcoholic disinfectant solution (HAD Hand Wash) in comparison with benzalkonium chloride alcoholic lotion. The bacterial reduction rate obtained by hand washing with a single 3 ml application was 93.8% for HAD Hand Wash and 94.1% for benzalkonium chloride alcoholic lotion. Thus, excellent antiseptic efficacy was obtained with both disinfectants. Roughening of hand skin which appeared in association with HAD Hand Wash solution was transient and mild in nature in all of the cases, indicating the high safety of this disinfectant. It is justified to say from these findings that HAD Hand Wash is useful as a hand and finger disinfectant.

Antisepsis↗
PubMed1993

Comparison of bactericidal activities of various disinfectants against methicillin-sensitive Staphylococcus aureus and methicillin-resistant Staphylococcus aureus.

Various disinfectants were compared in terms of the duration of bactericidal activity against methicillin-sensitive Staphylococcus aureus (MSSA), and methicillin-resistant Staphylococcus aureus (MRSA), among S. aureus isolated in our hospital. Strains of S. aureus which showed minimum inhibitory concentrations of cloxacillin of less than 1.56 micrograms/ml and of 3.13 micrograms/ml or higher were designated MSSA and MRSA respectively. There was no difference in sensitivity to disinfectants between MSSA and MRSA. There was a great variation in the duration of bactericidal activity of chlorhexidine gluconate against these species with the majority requiring contact times of between 2 minutes and over 20 minutes. All strains except for one strain of MRSA were killed within 20 seconds after disinfection with benzalkonium chloride. All strains were killed within 20 seconds after disinfection with alkyldiaminoethylglycine hydrochloride or povidone-iodine.

Benzalkonium Compounds↗
PubMed1993

[Hemofiltration for the treatment of patients with congestive heart failure].

Hemofiltration is usually performed to patients with renal failure but is also an effective method for treating patients with congestive heart failure due to various causes such as hypotension, low cardiac output, oliguria and anasarca. By continuing 24hr a day at low blood flow rate, CAVH (Continuous Arteriovenous Hemofiltration) or CVVH (Continuous Venousvenous Hemofiltration) can remove the body fluid up to 500 ml/hr without much affecting systemic circulation. Successive management of body fluid even results in the recover of renal insufficiency due to decreased renal blood flow or drug overload. To perform hemofiltration safely, it is important to monitor the systemic circulation. Usually we monitor the diameter of IVC (Inferior vena cava) with ultrasonography thought the procedure the to detect changes in blood volume simultaneously.

Anticoagulants↗