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Biomedical subjects

K Uchino

Publications and source records attributed to K Uchino.

At least 19 recordsLinked to original sources
PubMed2007

Germ line transformation of the silkworm, Bombyx mori, using the transposable element Minos.

We investigated the use of Minos as a vector for transgenesis in the silkworm, Bombyx mori. We first constructed a vector plasmid with the green fluorescent protein (GFP) gene fused with the silkworm cytoplasmic actin gene (A3) promoter, and a helper plasmid with the Minos transposase gene controlled by the same A3 promoter. Injection of the vector and helper plasmid DNA into silkworm eggs produced transgenic animals in the following generation. The efficiency of transgenic silkworm production using this method was much lower than that obtained using piggyBac-mediated germ line transformation. However, >40-fold increase in the efficiency of producing transgenic silkworms was obtained using an in vitro synthesized source of Minos transposase mRNA. We conclude that the Minos transposon is a useful vector for construction of transgenic silkworms, particularly when in vitro synthesized mRNA is used. This is the first report showing that Minos can be used as a vector for germ-line transformation in lepidopteran insects.

Actins↗
PubMed2005

Gastro-intestinal patch system for the delivery of erythropoietin.

The absorption of erythropoietin (EPO) from rat small intestine was studied using gastro-intestinal patches (GI-PS) in the presence of absorption enhancers. Surfactants such as a saturated polyglycolysed C8-C18 glyceride (Gelucire 44/14), PEG-8 capryl/caprylic acid glycerides (Labrasol), and polyoxyethylene hydrogenated castor oil derivative (HCO-60) were used as absorption enhancers at 143, 94 and 20 mg/kg, respectively. The absorption of EPO was studied by measuring serum EPO levels by an ELISA method after small intestinal administration of EPO-GI-PS preparation in rats at the EPO dose level of 100 IU/kg. Labrasol showed the highest absorption enhancing effect after intrajejunum administration with maximum serum EPO level of 84.1+/-11.4 mIU/ml while Gelucire 44/14 and HCO-60 showed 43.5+/-9.8 and 26.5+/-2.3 mIU/ml, respectively. The appropriate site for EPO absorption was also investigated. Jejunum was found to be the most efficient absorption site for the absorption of EPO from GI-PS. Using Labrasol as the absorption enhancer and jejunum as the absorption site, the effect of EPO dose on EPO absorption was studied by increasing the EPO dose from 50, to 100, 300 and 600 IU/kg. It was found that 100 IU/kg was the optimum dose with a serum EPO level of 84.1+/-11.4 mIU/ml while escalating doses showed decreases in serum EPO levels 48.3+/-5.6 for 300 IU/kg and 50.6+/-10.3 mIU/ml for 600 IU/kg. The percent bioavailability (BA) of EPO-GI-PS with Labrasol as absorption enhancer was 7.9 at 50 IU/kg, 12.1 at 100 IU/kg, 3.2 at 300 IU/kg and 1.2 at 600 IU/kg. Histological studies showed no adverse effect at the site of administration.

Administration, Oral↗
PubMed2004

Ischemic stroke subtypes among Mexican Americans and non-Hispanic whites: the BASIC Project.

Ischemic stroke subtype distribution was compared between Mexican Americans (MAs) and non-Hispanic whites (NHWs) in a community-based stroke surveillance study in Nueces County, TX. There was no difference in the distribution of stroke subtype by ethnicity (p = 0.19). There was a similar proportion of small-vessel and large-artery strokes between the two ethnic groups (p = 0.32). Differences in stroke rates among MAs and NHWs are not explained by the distribution of ischemic stroke subtypes.

Age Distribution↗
PubMed2003

Quantitative assessment of the total myocardial uptake ratio of 123I-BMIPP by using the Ishii-MacIntyre method is useful for predicting cardiac complications in patients with mitochondrial encephalomyopathy or myotonic dystrophy.

We evaluated the usefulness of the total myocardial uptake ratio (TMUR) of 15-(p-[123I]iodophenyl)-3(R,S)-methyl-pentadecanoic acid (123I-BMIPP) for predicting cardiac complications in patients with mitochondrial encephalomyopathy or myotonic dystrophy. Six patients with mitochondrial encephalomyopathy, four with myotonic dystrophy, and 10 control subjects were studied. Quantitative assessment of 123I-BMIPP dynamic myocardial imaging was performed, and the TMUR of 123I-BMIPP was calculated according to the Ishii-MacIntyre method. Then, the TMUR was compared in the 10 patients and 10 healthy controls, and all patients were followed for 56.1+/-22.1 months to evaluate cardiac complications. TMUR in patients (2.69+/-0.64) was significantly (P =0.01) lower than that in controls (3.28+/-0.25). Three patients in whom the TMUR value was above 3.00 had no cardiac complications. On the other hand, all patients in whom TMUR was below 3.00 had some kind of cardiac complication during the follow-up period. Two patients showed progressive conduction abnormality and underwent pacemaker implantation, one patient had sick sinus syndrome and underwent pacemaker implantation, another patient showed non-sustained ventricular tachycardia and paroxysmal atrial fibrillation, and four of seven patients, including one with a pacemaker, showed an increased cardiothoracic ratio value over 50%. In conclusion, measurement of the TMUR by the Ishii-MacIntyre method is useful for evaluating the development of cardiac complications in patients with mitochondrial encephalomyopathy or myotonic dystrophy.

Adult↗
PubMed2003

[The stratification of surgically treated T4 (stage IIIb) primary lung cancers; analysis of cases with intrapulmonary metastases in the same lobe as the primary tumors (pm 1) and invading adjacent organs].

OBJECTIVE: The purpose of this article was to investigate the validity of T4 classification of primary non-small cell lung cancer. METHODS: We retrospectively reviewed the clinical outcome of cases with pm 1 (n = 65) and T4 tumors invading adjacent organs (n = 36). RESULTS: When the pm 1 tumors were excised completely (n = 57), the prognosis of these cases was affected by the pN factor (5-year survival rate: pN 0-1; 70.1%, pN 2-3; 7.7%, p = 0.0002) and comparable to that of T2 diseases (pN 0-1 cases: p = 0.7315). The patients who underwent complete resection for their pm 1 tumors had a significantly better prognosis than cases with disseminations or malignant pleural effusions which had the same T4 classification (p < 0.0001). The prognosis of the patients who underwent complete resection for the tumors invading adjacent organs (classified under T4) was similar to that of T3 diseases (pN 0-1 cases: p = 0.7116). CONCLUSIONS: Patients whose lung cancer is classified as T4 comprise 2 subgroups; those whose tumors can be completely resected, and those in whom complete resection is impractical. There is a significant difference in the management and the prognosis between these 2 groups although they share the same T4 classification.

Adolescent↗
PubMed2002

Diffusion abnormalities in patients with Wernicke encephalopathy.

Diffusion-weighted imaging (DWI) can help to diagnose acute ischemic stroke. Other nonischemic disorders may show abnormal signals with DWI. The authors report two cases of Wernicke encephalopathy with DWI signal changes in characteristic midline locations, one with reduction in apparent diffusion constant and one without. DWI abnormalities may suggest early thiamine deficiency and are useful in diagnosing Wernicke encephalopathy.

Adult↗
PubMed2001

Synthesis and anti-HIV activity of nonatyrosine N- and O1-9-decasulfate.

To develop a potent and effective anti-HIV compound with a definite polyanionic structure, synthesis of oligotyrosine sulfates by oligomerization with simultaneous sulfation of tyrosine was tried. One component was successfully isolated from the mixture containing many products as its sodium salt (Y-ART-4) and was identified as the salt of nonatyrosine N- and O1-9-decasulfate, NaO3S-[Tyr(SO3Na)]9-ONa. Anti-HIV activity of Y-ART-4, determined from the protection it provided against HIV-induced cytopathic effects, was almost the same with that of dextran sulfate and curdlan sulfate.

Anti-HIV Agents↗
PubMed2001

Loss mechanisms in piezoelectrics: how to measure different losses separately.

Losses in piezoelectrics are considered in general to have three different mechanisms: dielectric, mechanical, and piezoelectric losses. This paper deals with the phenomenology of losses first, then how to measure these losses separately in experiments. We found that heat generation at off-resonance is caused mainly by dielectric loss tan delta' (i.e., P-E hysteresis loss), not by mechanical loss, and that a significant decrease in mechanical Qm with an increase of vibration level was observed in resonant piezoelectric ceramic devices, which is due to an increase in the extensive dielectric loss, not in the extensive mechanical loss. We propose the usage of the antiresonance mode rather than the conventional resonance mode, particularly for high power applications because the mechanical quality factor QB at an antiresonance frequency is larger than QA at a resonance frequency.

Journal Article↗
PubMed2001

Longitudinal-bending mode micromotor using multilayer piezoelectric actuator.

Longitudinal-bending mode ultrasonic motors with a diameter of 3 mm were fabricated using stacked multilayer piezoelectric actuators, which were self-developed from hard lead zirconate titanate (PZT) ceramic. A bending vibration was converted from a longitudinal vibration with a longitudinal-bending coupler. The motors could be bidirectionally operated by changing driving frequency. Their starting and braking torque were analyzed based on the transient velocity response. With a load of moment of inertia 2.5 x 10(-7) kgm2, the motor showed a maximum starting torque of 127.5 microNm. The braking torque proved to be a constant independent on the motor's driving conditions and was roughly equivalent to the maximum starting torque achievable with our micromotors.

Journal Article↗
PubMed2001

Entry criteria and baseline characteristics predict outcome in acute stroke trials.

UNLABELLED: Background and Purpose-We sought to study the range of entry criteria and baseline characteristics in acute stroke trials and to understand their effects on patient outcomes. METHODS: -Randomized, placebo-controlled therapeutic trials in patients with acute ischemic stroke were identified. Entry criteria, baseline clinical characteristics, and outcome were extracted for the placebo group of each trial. The relationship between key variables was then determined. RESULTS: -Across 90 placebo groups identified, there was great variation in entry criteria and outcome measures. This was associated with divergent outcomes; for example, in some studies most placebo group patients died, while in other studies nearly all had no disability. Entry criteria were significantly correlated with outcome; for example, higher age cutoff for study entry correlated with 3-month mortality. Entry criteria also predicted baseline clinical characteristics; for example, wider time window for study entry correlated directly with time to treatment and inversely with stroke severity (initial National Institutes of Health Stroke Scale score). Baseline characteristics predicted outcome. Greater stroke severity predicted higher 3-month mortality rate; despite this, successful thrombolytic trials have enrolled more severe strokes than most trials. The mean age of enrollees also predicted 3-month mortality and was inversely related to percentage of patients with 3-month Barthel Index score >/=95. The strongest predictors of 3-month mortality were obtained with multivariate models. CONCLUSIONS: -Acute stroke studies vary widely in entry criteria and outcome measures. Across multiple studies, differences in entry criteria, and the baseline clinical characteristics they predict, influence patient outcomes along a continuum. In some studies, enrolling a specific subset of patients may have improved the chances of identifying a treatment-related effect, while in others, such chances may have been reduced. These findings may be useful in the design of future stroke therapeutic trials.

Acute Disease↗
PubMed2001

[No relation between angiotensin-converting enzyme (ACE) inhibitor-induced cough and ACE gene polymorphism, plasma bradykinin, substance P and ACE inhibitor concentration in Japanese patients].

Persistent dry cough is well known as the most common side-effect of angiotensin-converting enzyme (ACE) inhibitors. We examined the relationship between a cough and ACE gene polymorphism, plasma bradykinin (BK), substance P (SP) and ACE inhibitor concentrations in patients with hypertension or chronic nephritis. First, ACE genotyping was carried out in 96 patients, 42 with coughs and 54 without coughs, which had been treated with various kinds of ACE inhibitors. However, no significant difference in the ACE genotypes was observed between the two groups. Second, the plasma concentrations of BK, SP and ACE inhibitor were measured in 12 patients, which were treated with trandolapril at a daily dose of 1 mg for 4-33 weeks. In 3 patients, the cough was induced during the trandolapril therapy, while it was induced not in 9 patients. The plasma levels of BK and SP did not significantly change after trandolapril administration in the patients with and without coughs. Between the two groups, there were no significant differences in the plasma levels of BK and SP either before or after the trandolapril therapy. Also the plasma concentrations of trandolapril and trandolaprilat, the active metabolite of trandolapril, did not significantly differ between the two groups. These results suggest that there is no significant relationship between the ACE inhibitor-induced cough and ACE gene polymorphism, plasma BK, SP and ACE inhibitor concentrations in patients with hypertension or chronic nephritis.

Aged↗
PubMed2001

Involvement of CYP2B6 in n-demethylation of ketamine in human liver microsomes.

Ketamine is metabolized by cytochrome P450 (CYP) leading to production of pharmacologically active products and contributing to drug excretion. We identified the CYP enzymes involved in the N-demethylation of ketamine enantiomers using pooled human liver microsomes and microsomes from human B-lymphoblastoid cells that expressed CYP enzymes. The kinetic data in human liver microsomes for the (R)- and (S)-ketamine N-demethylase activities could be analyzed as two-enzyme systems. The K(m) values were 31 and 496 microM for (R)-ketamine, and 24 and 444 microM for (S)-ketamine. Among the 12 cDNA-expressed CYP enzymes examined, CYP2B6, CYP2C9, and CYP3A4 showed high activities for the N-demethylation of both enantiomers at the substrate concentration of 1 mM. CYP2B6 had the lowest K(m) value for the N-demethylation of (R)- and (S)-ketamine (74 and 44 microM, respectively). Also, the intrinsic clearance (CL(int): V(max)/K(m)) of CYP2B6 for the N-demethylation of both enantiomers were 7 to 13 times higher than those of CYP2C9 and CYP3A4. Orphenadrine (CYP2B6 inhibitor, 500 microM) and sulfaphenazole (CYP2C9 inhibitor, 100 microM) inhibited the N-demethylase activities for both enantiomers (5 microM) in human liver microsomes by 60 to 70%, whereas cyclosporin A (CYP3A4 inhibitor, 100 microM) failed to inhibit these activities. In addition, the anti-CYP2B6 antibody inhibited these activities in human liver microsomes by 80%, whereas anti-CYP2C antibody and anti-CYP3A4 antibody failed to inhibit these activities. These results suggest that the high affinity/low capacity enzyme in human liver microsomes is mediated by CYP2B6, and the low affinity/high capacity enzyme is mediated by CYP2C9 and CYP3A4. CYP2B6 mainly mediates the N-demethylation of (R)- and (S)-ketamine in human liver microsomes at therapeutic concentrations (5 microM).

Aryl Hydrocarbon Hydroxylases↗
PubMed2000

Stereoselective high-performance liquid chromatographic determination of ketamine and its active metabolite, norketamine, in human plasma.

A stereoselective high-performance liquid chromatographic method for the determination of the enantiomers of ketamine and its active metabolite, norketamine, in human plasma is described. The compounds were extracted from plasma by liquid-liquid extraction three times in a combination of cyclohexane with 2.5 M NaOH, 1 mM HCl and 1 M carbonate buffer. Stereoselective separation was achieved on a Chiralcel OD column with a mobile phase of n-hexane-2-propanol (98:2, v/v). The detection wavelength was 215 nm. The lower limits of the determination of the method were 5 ng/ml for ketamine and 10 ng/ml for norketamine. The intra- and inter-day coefficients of variation ranged from 2.9 to 9.8% and from 3.4 to 10.7% for all compounds, respectively. The method was sensitive and sufficiently reproducible for stereoselective monitoring of ketamine and norketamine in human plasma during pharmacokinetic studies after the administration of ketamine for analgesia.

Adult↗
PubMed2000

Molecular characterization of Hop latent virus and phylogenetic relationships among viruses closely related to carlaviruses.

The complete nucleotide sequence of the hop latent virus (HpLV) genome was determined. The viral RNA genome is 8,612 nucleotides long, excluding the poly(A) tail, and contains six open reading frames (ORFs), which encode putative proteins of 224-kDa (ORF 1), 25-kDa (ORF 2), 11-kDa (ORF 3), 7-kDa (ORF 4), 34-kDa (ORF 5), and 12-kDa (ORF 6). ORF 5 encodes the coat protein as demonstrated by N-terminal sequencing of three proteolytic peptides derived from the virus particle. The genome organization of HpLV is similar to that of other species in the genus Carlavirus, and the overall sequence of HpLV is more similar to that of Potato virus M than to sequences of other carlaviruses reported to date. The amino acid sequences of the putative methyltransferase, RNA helicase, and RNA-dependent RNA polymerase encoded in ORF 1 and an 'accessory' helicase encoded in ORF 2 of the HpLV genome were compared with those of viruses in the 'tymo' lineage: the genera Carlavirus, Potexvirus, Allexivirus, Foveavirus, Trichovirus, Capillovirus, Vitivirus, and Tymovirus. The phylogenetic relationships among the viruses in these genera are discussed. This is the first molecular characterization of a carlavirus infecting hop plants.

Amino Acid Sequence↗
PubMed2000

Cymbal array: a broad band sound projector.

A prototype 3 x 3 planar cymbal transducer array was built and tested. The array has a radiating area of 5.5 cm x 5.5 cm and a thickness of less than 8 mm. The measured transmitting voltage response was above 134 dB re 1 microPa/V @ 1 m and flat over the frequency range of 16 and 100 kHz. Array interaction was analyzed using an equivalent circuit model. The array interaction leads to variations in radiation resistance and velocity of the transducers in the array according to their surroundings in the array. The effect is enhanced overall efficiency and a flat response.

Equipment Design↗
PubMed2000

Acute eosinophilic myocarditis in a young woman.

The first stage of eosinophilic myocarditis is called the necrotizing phase. This stage of eosinophilic myocarditis of unknown cause is often fulminant and rapidly fatal, occurring predominantly in males. Here, we report a case of eosinophilic myocarditis in the acute necrotizing phase occurred without known cause in a 23-year-old Japanese female. Severe diffuse hypokinesis of the left ventricular wall motion (ejection fraction 19.3%), significant concentric edematous thickening of the left ventricular wall (20.1 mm in diastole) and a moderate amount of pericardial effusion (10 mm wide echo free space posteriorly) were revealed by echocardiography. Eosinophils were observed and degranulated eosinophilic cationic proteins were stained with antibody against eosinophilic cationic proteins (EG2) in the myocardial specimens obtained by myocardial biopsy. In spite of its severity, the disease resolved promptly with steroid therapy.

Acute Disease↗
PubMed1999

[Preparation of ketamine tablets for treatment of patients with neuropathic pain].

Ketamine is known to have distinguished analgesic effects without anesthetic when administered in a low dose. Since ketamine is not commercially available except injection forms, we prepared ketamine tablets for the home-care medication of patients with neuropathic pain. The direct compression or wet granulation method was employed to form 150 mg of tablets containing 50 mg of ketamine. The latter method was superior to the former one in terms of content uniformity, weight variation and disintegration tests of the tablets. Ketamine contents in the tablet prepared by the wet granulation method were unchanged for 12 weeks under the conditions of 25 degrees C and 75% relative humidity (RH). The Cmax and AUC0-3 h values for ketamine after administration of the tablet were slightly smaller than those of the syrup in a healthy volunteer. However, analgesic effects of the tablet was similar to that of the syrup in a patient with neuropathic pain. And the tablet was also effective for another four patients with neuropathic pain. These results indicate that ketamine tablets are useful for the home-care medication of patients with neuropathic pain.

Adult↗