Biomedical subjects

N Taira

Publications and source records attributed to N Taira.

At least 19 recordsLinked to original sources

PubMed2003

Larvicidal effects of several chemicals on Strongyloides infective larvae.

The larvicidal effects of 11 anthelmintics, 7 pesticides and 4 disinfectants were evaluated with infective larvae of Strongyloides papillosus (SPL) and Strongyloides venezuelensis (SVZ). The lethal concentrations against SPL and SVZ were found to be similar. Three chemicals (dichlorvos, levamisole and trichlorfon) showed highest larvicidal effects. The 50% lethal concentration (LC(50)) values for the three compounds against SPL larvae were 0.08, 0.24, and 0.59 ppm, respectively.

Animals↗

PubMed2001

Pancreatitis induced by valproic acid: report of a case.

A 22-year-old woman with intellectual impairment, who had been taking valproic acid continuously for 19 years since being diagnosed with epiloia at the age of 3 years, presented to our hospital following the sudden development of epigastric pain. An abdominal computed tomography scan revealed acute exacerbation of chronic pancreatitis. Conservative treatment was initiated, despite which the pancreatitis became exacerbated, necessitating resection of the pancreatic head and duodenum. Histological examination of the resected specimens revealed a large number of pancreatic calculi in the main pancreatic duct, suggesting chronic pancreatitis with fibrosis at the periphery. The incidence of pancreatitis developing in association with valproic acid is unclear; however, only 40 such cases have been reported in the English literature. Most of the patients previously described presented with acute pancreatitis in the initial stage. However, the clinical course of our patient, with acute exacerbation following a relatively chronic course, was different from those previously described, suggesting the presence of chronic pancreatitis related to valproic acid.

Adult↗

PubMed2001

Primary subclavian venous thrombosis which developed after sleeping with the arm in an outstretched position: report of a case.

Primary subclavian venous thrombosis is more rare than secondary thrombosis. This type of thrombosis is called "effort thrombosis" or Paget-Schroetter syndrome, and develops after a strenuous effort of the superior limb. A day after a 55-year-old man got drunk and slept in the left lateral position in combination with an abducted and elevated position of the left superior limb, he became aware of swelling and an oppressive feeling in his left superior limb and was admitted 9 days later. Thrombus of the left axillary-subclavian vein was confirmed by venography, and thrombolytic therapy with urokinase was performed immediately. The left arm symptoms improved for the most part. Venography after the therapy revealed thrombolysis at the site of the axillary vein, while the subclavian vein enhanced the collateral vessel pathway. The patient was discharged on the seventh hospital day, and anticoagulant therapy with oral warfarin sodium has since been continued. This is considered to be a rare case of subclavian venous thrombosis caused by sleeping in an abnormal position with the arm outstretched.

Alcoholic Intoxication↗

PubMed2001

Frontal lobe dementia with abnormal cholesterol metabolism and heterozygous mutation in sterol 27-hydroxylase gene (CYP27).

Of the primary dementing disorders that cause frontotemporal dementia, the best-known is Pick disease. We report on a 44-year-old woman with progressive frontal lobe dementia and spastic paraplegia. Examination revealed increased serum levels of cholestanol with abnormal cholesterol metabolism and a heterozygous mutation of the sterol 27-hydroxylase gene (CYP27). Biochemical findings were compatible with cerebrotendinous xanthomatosis (CTX); however, the clinical manifestations were very dissimilar. To our knowledge, a symptomatic carrier of this mutation among CTX patients has not been reported. We speculate that the present patient has a previously undescribed neurodegenerative disease related to abnormal cholesterol metabolism with this heterozygous mutation.

Adult↗

PubMed2001

Differential sensitivity of Kv1.4, Kv1.2, and their tandem channel to acidic pH: involvement of a histidine residue in high sensitivity to acidic pH.

We studied the effects of acidic pH on the currents through voltage-gated K+ channels, Kv1.2, Kv1.4, and their tandem construct (Kv1.4-Kv1.2). Kv1.4 currents were inhibited considerably under acidic pH in a voltage-independent manner, whereas Kv1.2 currents were less inhibited in an apparently voltage-dependent manner. The apparent voltage-dependent block of Kv1.2 currents was mostly ascribed to the shift of activation voltage, which is probably due to surface charge effects of H+ ions. Mutagenesis analysis identified the histidine residue at 508 (H508) in the S5-H5 linker as a molecular determinant of pH sensitivity of Kv1.4. Currents through the tandem channel showed intermediate characteristics between the two parent channels in both sensitivity and voltage dependence of pH effects. Our results suggest that 1) the H508 plays a critical role in determining pH sensitivity of Kv1.4; and 2) the two parent channels, Kv1.2 and Kv1.4, are involved in determining pH sensitivity and apparent voltage dependence of the tandem channel.

Amino Acid Sequence↗

PubMed2000

Changes in the inactivation of rat Kv1.4 K(+) channels induced by varying the number of inactivation particles.

N-type inactivation of rat Kv1.4 channels with one, two, or four inactivation balls was investigated using homogeneous populations of channels expressed in Xenopus oocytes. Tandem dimeric and tetrameric constructs of Kv1.4 were made. Channels encoded by tandem cDNAs Kv1. 4-Kv1.4Delta1-145 and Kv1.4-[Kv1.4Delta1-145](3) have two or only one tethered inactivation ball, respectively, whereas Kv1.4 itself encodes channels having four inactivation balls. The time constants for inactivation of macroscopic currents were increased significantly as the number of inactivation balls was decreased, whereas the time constants for recovery from inactivation were not modified. The ratios of the rate constants of inactivation (k(inact)) of Kv1.4-Kv1.4Delta1-145 and Kv1.4-[Kv1.4Delta1-145](3) channels to that of the Kv1.4 channel were 0.65 and 0.4, respectively, whereas the ratios of the rate constant of recovery (k(rec)) of these channels to that of Kv1.4 were almost unity. The rate constants k(inact) for channels having two and four inactivation balls are smaller than those that would be expected if inactivation balls on each channel are independent, suggesting some interaction occurs between inactivation balls. Furthermore, noninactivating current became apparent as the number of inactivation balls on a channel was decreased.

Animals↗

PubMed2000

A patient with primary biliary cirrhosis associated with autoimmune hemolytic anemia.

Primary biliary cirrhosis is often associated with autoimmune conditions, such as thyroid disease, sicca complex, and rheumatoid arthritis. However, an association with autoimmune hemolytic anemia has rarely been reported. We present a case of primary biliary cirrhosis associated with warm type autoimmune hemolytic anemia, and we review prior reports.

Aged↗

PubMed1999

Psychiatric inpatients and chromosome deletions within 22q11.2.

Velocardiofacial syndrome (VCFS) is a congenital disorder characterised by multiple dysmorphisms, cleft palate, cardiac anomalies, and learning disabilities due to a microdeletion of chromosome 22q11.2. Although VCFS is often associated with psychiatric symptoms, its prevalence among psychiatric patients is unknown. A total of 326 patients admitted in September and October 1997 to a Japanese psychiatric hospital were screened for the clinical features of VCFS. Twelve patients with minor facial dysmorphia were identified; chromosomal analysis with fluorescent in situ hybridisation (FISH) was performed in six patients who, further assessment suggested, were most likely to have VCFS. Chromosome 22q11.2 deletion was identified in a 41 year old woman who had symptoms of schizophrenia but no major dysmorphia, such as cardiovascular anomalies and cleft palate. Her behavioural and neuropsychological profiles were similar to those previously reported in VCFS. She was hemizygous for the FISH probe N25 (GDB locus D22S75) and also for probes N72H9 (D22S181), sc11.1a, C443 (D22S941), sc4.1 (D22S134), sc11.1b, N19B3 (D22S264), N122B5 (D22S934), and N77F7 (D22S939). The size of the deletion was about 3 Mb. Our patient had only some features of VCFS including a square nasal root, hypernasal speech, and hypoparathyroidism. She did, however, have the common larger deletion of type A. This finding suggests that psychiatric symptoms in VCFS can occur without major developmental symptoms such as cardiovascular anomalies and cleft palate. Additional patients with schizophrenia may have subtle features of VCFS which are unrecognised on routine medical examinations.

Abnormalities, Multiple↗

PubMed1999

Similarity and dissimilarity in mode and mechanism of action between YT-146, a selective adenosine receptor A2 agonist, and adenosine in isolated canine hearts.

To elucidate the differences in mode and mechanism of action between YT-146, a highly selective adenosine A2 receptor agonist, and adenosine, we compared their effects on coronary circulation and myocardium and modifications of these effects by glibenclamide, a blocker of ATP-sensitive potassium (K) channels, in three kinds of isolated, blood-perfused canine heart preparations. YT-146 and adenosine were injected i.a. In all preparations both YT-146 and adenosine increased coronary blood flow and in this respect YT-146 was about 5 times as potent as adenosine. The increase in blood flow caused by adenosine was transient, whereas that produced by YT-146 was biphasic; the transient increase was followed by a sustained one. In isolated, blood-perfused sinoatrial (SA) node preparations, YT-146 failed to affect sinus rate, whereas adenosine reduced sinus rate by about 38% at its maximum effect. In isolated, blood-perfused atrioventricular (AV) node preparations, when injected into the artery supplying the AV node, YT-146 exerted no effect on AV conduction time, whereas adenosine prolonged AV conduction time by about 17% at the maximum effect. In isolated, blood-perfused papillary muscle preparations, the force of contraction was affected by neither YT-146 nor adenosine. In the same preparations the effect of YT-146 in increasing coronary blood flow was antagonized by glibenclamide in such a manner that the maximum increase was suppressed, but that of adenosine was not. Reactive hyperemia induced by ischemia for 30 seconds was not affected by glibenclamide. These results suggest that although both YT-146 and adenosine produce an increase in coronary blood flow via adenosine A2 receptors, the opening of ATP- or glibenclamide-sensitive K channels is involved in the action of the former, but scarcely in the action of the latter. The opening of ATP- or glibenclamide-sensitive K-channels is less likely involved in reactive hyperemia.

Adenosine↗

PubMed1999

[Palliation for a recurrent lung cancer patient with superior vena cava syndrome by arterial infusion of CDDP through the implantable port system--a case report].

A case of lung cancer with superior vena cava syndrome treated with internal thoracic arterial infusion of anti-cancer drugs by the implantable port system was reported with our technique. In this case, blood supply was mainly from internal thoracic artery. A trans-catheterial contrast enhanced helical CT was very helpful to identify the routes of blood supply to the lung cancer.

Aged↗

PubMed1999

[Documents related to a medical prescription book in the Date Museum (Date City, Hokkaido)].

This is a report of a prescription book which Munetomo Murayama, a medical doctor attached to the Date Watari Feudal Clan, inherited from his ancestors and handed on to his descendants. It is now preserved in the Date Museum in Date, Hokkaido, Japan, and the records there show that it was donated by a descendant of Dr. Murayama. The prescription book is unique in its detailed descriptions that are different from traditional medicine. It describes specific illnesses and the medications that were used in their treatment. The illnesses described are not serious ailments but illnesses commonly encountered in daily life and commonly available (over-the-counter) drugs recommended for the treatment of stomach ailments, diarrhea ; drugs for external use, also 'tochino' (a non-prescription drug commonly used for all kinds of illnesses in old times in Japan), drugs for tiredness, hemorrhoids, cough relief, aroma therapy, and others. Some of the drugs are also recognized today as being effective and having medicinal effects. They are thought to be agents with medicinal effects and the treatments reported by Dr. Murayama are separate and different from the Shimizu style in which they are applied.

Drug Prescriptions↗

PubMed1998

[Primary liposarcoma of the anterior mediastinum--case report and review of literature].

A 76-year-old male with anterior mediastinal tumor was admitted to our hospital. He had undergone mediastinal lipoma surgery 3 years earlier. The tumor was excised surgically. Microscopic sections of the tumor showed liposarcoma composed of myxoid tissue. Further examination of prior specimens taken from this patient proved this case to be a recurrence of liposarcoma. Poorly differentiated tumors, which pathologically tend to be more cellular with less fat per cell component, are likely to have high CT numbers. But CT number is not sufficient to distinguish well-differentiated liposarcoma from benign lipoma.

Aged↗

PubMed1997

A mammalian transient type K+ channel, rat Kv1.4, has two potential domains that could produce rapid inactivation.

The "ball and chain" model has been shown to be suitable for explaining the rapid inactivation of voltage-dependent K+ channels. For the Drosophila Shaker K+ channel (ShB), the first 20 residues of the amino terminus have been identified as the inactivation ball that binds to the open channel pore and blocks ion flow (Hoshi, T., Zagotta, W. N., and Aldrich, R. W. (1990) Science 250, 533-538; Zagotta, W. N., Hoshi, T., and Aldrich, R. W. (1990) Science 250, 568-571). We studied the structural elements responsible for rapid inactivation of a mammalian transient type K+ channel (rat Kv1.4) by constructing various mutants in the amino terminus and expressing them in Xenopus oocytes. Although it has been reported that the initial 37 residues might form the inactivation ball for rat Kv1.4 (Tseng-Crank, J., Yao, J.-A., Berman M. F., and Tseng, G.-N. (1993) J. Gen. Physiol. 102, 1057-1083), we found that not only the initial 37 residues, but also the following region, residues 40-68, could function independently as an inactivation gate. Like the Shaker inactivation ball, both potential inactivation domains have a hydrophobic amino-terminal region and a hydrophilic carboxyl-terminal region having net positive charge, which is essential for the domains to function as an inactivation gate.

Amino Acid Sequence↗

PubMed1997

Zoonotic potential of infection with Fasciola spp. by consumption of freshly prepared raw liver containing immature flukes.

Mice were successfully infected with metacercariae of the Japanese Fasciola sp., resulting in the recovery of a mean number of 110 live immature flukes per mouse 4-5 days after inoculation. Twenty-four mice were then inoculated orally, each with a mean number of 68 freshly recovered immature flukes. The livers of 7 of the 24 recipient mice showed migratory lesions of capsular and subcapsular granulomatous infiltration and 2 of those mice also had haemorrhagic lesions. The lesions were typical of those caused by active migration of early immature flukes. However, no flukes were found in the livers of the recipient mice at necropsy when the flukes were aged 14 weeks. In another experiment, 10 piglets were given fresh livers of mice harbouring approximately 2000 live immature flukes aged 3-7 days. Two additional piglets were inoculated with 2000 metacercariae of Fasciola. All pigs were killed when the flukes were 14 days old. Granulomatous lesions were present in all pigs, except in those that were given livers containing flukes aged 7 days. The lesions were localized, forming well-defined foci, different from the typical migratory lesions normally observed in mouse or sheep liver at the early stage of fluke migration. From the 10 pigs given livers, 65 live flukes were recovered at necropsy, 0.29% of the estimated number of immature flukes given. From the 2 pigs which received 2000 metacercariae each, a total of 198 flukes were recovered (5%). The results of the experiments suggest that humans consuming raw liver dishes prepared from fresh livers infected with immature Fasciola spp. could become infected with liver fluke.

Animals↗

PubMed1996

Faecal examination of Fasciola eggs fixed with formalin solution using the beads technique.

Faecal examination for Fasciola eggs which were preserved in 5% and 10% formalin and TAF solutions for 6 years was carried out using the Beads technique. The morphological characters and the distinctive yellowish color of Fasciola eggs were retained and appeared similar to those of fresh eggs. The mean egg recovery rate of eggs in TAF solution was significantly lower than the others (P < 0.01). The egg recovery rates from 5% and 10% formalin samples were 57.2% and 60.8%, respectively, and these values were similar to the value of 58.8% for fresh Fasciola eggs in cattle faeces. For Paramphistomum eggs, preserved with 5% formalin, the mean egg recovery rate was 64.7%. Fasciola eggs and Paramphistomum eggs were easily identified by their morphological characters in this experiment. The present data demonstrated that preservation with 5% formalin solution is an acceptable means of storing faecal samples for later examination of Fasciola and Paramphistomum eggs using the Beads technique and presumably by other fluke sedimentation methods.

Animals↗

PubMed1996

Unitary current through the inward rectifier K+ channel cloned from rabbit heart--comparison with the native K+ channel.

Recently, we have cloned a cDNA for a putative cardiac inward rectifier K+ channel (RBHIK1) from rabbit cardiac muscles. However, it's single channel characteristics have remained unknown. Therefore, we investigated the single channel characteristics of the RBHIK1 channel expressed in Xenopus oocytes by the cell attached patch clamp configuration, and compared them with those of the native Ik1 channel of the freshly-isolated ventricular myocytes under similar temperature conditions. In patch clamp experiments with 145 mmol/l K+ in the pipette at room temperature (20-22 degrees C), both the RBHIK1 currents and the native Ik1 showed a strong inward rectifying property. The single channel conductance of the RBHIK1 channel was 17.8 +/- 0.47 pS (n = 4), and that of the native Ik1 channel was 23.5 +/- 0.29 pS (n = 5). The activities of the cloned channel were sensitive to the putative K+ channel blockers (TEA, Cs+ and Ba2+). The open and closed time histograms at -140 mV could be fitted by a single exponential both in the RBHIK1 channel and the native Ik1 channel. Although the closed-time histogram of the native Ik1 channel was fitted by a sum of two exponential curves, that of the RBHIK1 channel was fitted by a single exponential curve. The sublevel corresponding to two-thirds of the unitary current was observed both in the RBHIK1 channel and the native Ik1, but it was more frequently detected in the RBHIK1 channel. Amplitude histogram constructed at -140mV in the RBHIK1 channel exhibited three peaks, which indicated closed, full-open, and 2/3 sublevel state, respectively. Unitary current was calculated to be 2.5 pA and sublevel of the unitary current was 1.68 pA. These characterization in the single channel activities of the RBHIK1 channel will help to study the molecular regulation of the Ik1 channel in cardiac cells.

Animals↗

PubMed1996

Larval somatic antigens effective in inducing an IgG response and protection against Strongyloides papillosus infection.

A serum IgG response to Strongyloides papillosus infection was analysed in rabbits. IgG production was induced against 30-200 kDa larval somatic antigens and 21-160 kDa adult excretory/secretory (ES) antigens at 4 weeks postinfection. No immunoreactivity was detected between sera of infected animals and any proteins of larval ES and adult somatic antigens. Protection against larval challenge infection was investigated in rabbits immunized by primary infection and by intradermal inoculations of larval somatic and adult ES antigens. Primarily infected animals had 90% fewer or less worms from day 2 onwards after challenge, and lower faecal egg outputs after challenge, when compared with those in susceptible animals. Immunization with larval somatic antigens induced effective protection, showing 52.6-81.5% reductions in worm recovery from day 5 onwards after challenge, and lower faecal egg outputs after challenge. Systemic immunization with adult ES antigens failed to protect the animals against challenge. The possibility that resistance to S. papillosus reinfection is performed on the killing of migrating larvae in the early stages of infection is discussed. Systemic immune responses to larval somatic antigens might play an important role in the resistance.

Animals↗

PubMed1996

Biphasic antagonisms by beta-blockers against positive inotropic response through beta1-adrenoceptors in isolated canine right ventricular muscles: possible involvement of two beta 1-adrenoceptor subtypes.

In isolated canine right ventricular muscles, we investigated the differences in antagonisms by beta-blockers against the positive inotropic effects (PIEs) of isoproterenol, a nonselective agonist, and T-0509, a beta1-selective agonist. The selective beta1-blockers atenolol and bisoprolol antagonized the PIE of T-0509 monophasically in Schild analysis, showing pA2 values of 7.05 and 7.63, respectively. On the other hand, both blockers produced biphasic antagonism against the PIE of isoproterenol (ISO); therefore, two pKB values were obtained (7.75 and 4.25 and 7.82 and 5.76, respectively). Nadolol, a nonselective beta-blocker, also antagonized the PIE of T-0509 monophasically (pA2 value 7.58), but antagonized the PIE of ISO biphasically (pKB values 7.42 and 4.39). Because the different mode of antagonism by three beta-blockers between T-0509 and ISO could not be explained by the selectivities of beta-agonists and blockers for beta1- and beta2-adrenoceptors in the heart, two subtypes of beta1-adrenoceptors may exist together in canine ventricular muscles, and atenolol, bisoprolol, and nadolol may act as antagonists for the two subtypes with two different affinities.

Adrenergic beta-Agonists↗