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N Hatano

Publications and source records attributed to N Hatano.

At least 37 records · Page 2Linked to original sources
PubMed1998

Significance of "hands-on training" in laparoscopic surgery.

BACKGROUND: The objective of this study is to investigate the role and significance of a hand-on program designed to teach laparoscopic skills. METHODS: The course consisted of 3 half days. In vitro training in suturing and knot tying was covered on the 1st half day, and live animal surgery on the 2nd and 3rd half days, respectively. In vitro suturing and knot tying of the 15 course participants were video-recorded and analyzed four times during the course, basing on the time required to mount a needle in the needle driver (M), driving the needle in a rubber glove (D), and knot tying (T). RESULTS: Laparoscopic skills which require two-hand coordination (M, T) were significantly improved by hands-on training. Needle driving skill appeared to be essentially the same as that needed for open surgery. CONCLUSION: Hands-on training is an effective format particularly for laparoscopic skills in which two-hand coordination is essential.

Adult↗
PubMed1998

Enhancer-dependent, locus-wide regulation of the imprinted mouse insulin-like growth factor II gene.

The mouse insulin-like growth factor II (IGF-II) gene is subject to parental imprinting and is predominantly expressed from the paternal chromosome. This allele-specific expression is modified further by cell type, developmental stage, and growth conditions. We show that the ratio of the three major IGF-II mRNAs, each produced from a distinct promoter, is consistent in a variety of tissues and cells representing different modes and phases of the complex regulation. Nuclear run-on assays show that the major changes in total IGF-II mRNA level occur at the level of transcription. Moreover, a targeted disruption of the endoderm-specific enhancers, located 90 kb away from the gene, affects all promoters. The dependency of the promoters on distal enhancers is also shown by transgenesis experiments. Our findings suggest that enhancer-dependent, locus-wide mechanisms play a major role in the coordinate regulation of the multiple IGF-II promoters.

Animals↗
PubMed1998

A novel beta-N-acetylglucosaminidase from Streptomyces thermoviolaceus OPC-520: gene cloning, expression, and assignment to family 3 of the glycosyl hydrolases.

A beta-N-acetylglucosaminidase gene (nagA) of Streptomyces thermoviolaceus OPC-520 was cloned in Streptomyces lividans 66. The nucleotide sequence of the gene, which encodes NagA, revealed an open reading frame of 1,896 bp, encoding a protein with an Mr of 66, 329. The deduced primary structure of NagA was confirmed by comparison with the N-terminal amino acid sequence of the cloned beta-N-acetylglucosaminidase expressed by S. lividans. The enzyme shares no sequence similarity with the classical beta-N-acetylglucosaminidases belonging to family 20. However, NagA, which showed no detectable beta-glucosidase activity, revealed homology with microbial beta-glucosidases belonging to family 3; in particular, striking homology with the active-site regions of beta-glucosidases was observed. Thus, the above-mentioned results indicate that NagA from S. thermoviolaceus OPC-520 is classified as a family 3 glycosyl hydrolase. The enzyme activity was optimal at 60 degreesC and pH 5.0, and the apparent Km and Vmax values for p-nitrophenyl-beta-N-acetylglucosamine were 425.7 microM and 24.8 micromol min-1 mg of protein-1, respectively.

Acetylglucosaminidase↗
PubMed1998

Construction of a marine cyanobacterial strain with increased heavy metal ion tolerance by introducing exogenic metallothionein gene.

A marine cyanobacterial strain with enhanced heavy metal ion tolerance was constructed by introducing an exogenous cyanobacterial metallothionein gene, smtA, from a freshwater unicellular cyanobacterium, Synechococcus sp. PCC 7942. An expression vector harboring the c-phycocyanin (cpc) promoter and cpc N-terminal region was constructed and smtA was inserted into its multiple cloning site. The marine cyanobacterium, Synechococcus sp. NKBG 15041c, was highly sensitive to the heavy metal ions present in the medium. However, the recombinant marine cyanobacteria harboring the expression vector with smtA could grow even in the presence of 4 µM of CdCl2, at which concentration the wild-type strain did not grow.

Journal Article↗
PubMed1996

Nucleotide sequence of a 28-kb mouse genomic region comprising the imprinted Igf2 gene.

The mouse insulin-like growth factor II gene (Igf2) is physically linked to the insulin II gene (Ins2) and both are subject to tissue-specific genomic imprinting. The paternal-specific expression of Igf2 has been associated with hypermethylation of some CpG sites in the 5' flanking region and in the body of the gene. As a first step in analyzing the structural features of this imprinted locus, we here report the complete nucleotide sequence of Igf2, including all introns and the intergenic region adjacent to Ins2. This 28-kb segment of mouse chromosome 7 exhibits 80% overall identity with the corresponding rat sequence and has a high GC content of 52%. In addition to the known CpG island within the second Igf2 promoter, another island was identified approximately 2 kb 5' to the first exon. Other features of this locus include a 35-fold tandem repeat of an 11-bp sequence that overlaps Igf2 pseudo-exon 2, and a B2 repeat element in the intergenic region between Ins2 and Igf2. The GC-richness and the presence of CpG islands associated with tandem repeats are common features of imprinted genes and thus may play a role in the imprinting mechanism.

Animals↗
PubMed1996

Cloning of a marine cyanobacterial promoter for foreign gene expression using a promoter probe vector.

A marine cyanobacterial promoter was cloned to allow efficient foreign gene expression. This was carried out using chloramphenicol acetyl transferase (CAT) as a marker protein. For rapid and simple measurement of CAT activity, a method based on a fluorescently labeled substrate was improved by utilizing HPLC equipped with a flow-through fluorescent spectrophotometer. This method was used in conjunction with a newly constructed promoter probe vector. Cyanobacterial transformants, harboring plasmid containing a cloned 2-kbp marine cyanobacterial genomic fragment, showed a 10-fold higher CAT activity, compared with that achieved using the kanamycin-resistant gene promoter. From the sequence analysis of the cloned fragment, a putative promoter region was found.

Base Sequence↗
PubMed1996

The association of antibodies against human T cell lymphotropic virus type I (HTLV-I) pX gene mutant products with HTLV-I-associated myelopathy/tropical spastic paraparesis.

Antibodies specific for the products of the human T cell lymphotropic virus type I (HTLV-I) pX frame-shift mutants were studied by ELISA. The serum IgG antibodies to the synthetic peptide corresponding to one nucleotide insertion at position 7784 were significantly more common in patients with HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP) patients than in HTLV-I carriers who had neither HAM/TSP nor adult T cell leukemia (39% vs. 5%). The seropositivities to the other synthetic peptides, which corresponded to the one nucleotide deletion at position 7475 and the internal deletion of nt 7754-7819 and nt 7853-7936, were rare. A genetic study confirmed the presence of the responsible mutation of the pX gene in peripheral blood mononuclear cells and central nervous system tissue from HTLV-I-infected subjects with and without HAM/TSP. These results suggest that HTLV-I pX frame-shift mutants are expressed in vivo in HTLV-I carriers; they also induce antibodies. especially in those with HAM/TSP.

Adult↗
PubMed1995

A novel mutation causing an aberrant splicing in the protein 4.2 gene associated with hereditary spherocytosis (protein 4.2Notame).

We investigated a Japanese patient with protein 4.2 deficiency. SDS-PAGE showed a complete deficiency of protein 4.2, while Western blot analysis revealed a marked decrease in the amount of protein 4.2, and the existence of a doublet of 74 and 72 kDa bands. Direct sequencing and dot-blot hybridization with allele-specific oligonucleotide probes indicated that the proband was compound heterozygous for a missense mutation in codon 142 with Ala-->Thr (GCT-->ACT) and a single nucleotide substitution (G-->A) of the first base of intron 6 (G-->A) of the protein 4.2 gene. The former is the commonest mutation observed in cases of protein 4.2 deficiency, whereas the latter is a novel mutation, located within the consensus sequence of the 5' splicing site (AGGU) (Protein 4.2Notame). RT-PCR analysis using total RNA isolated from reticulocytes of the proband revealed that the intron 6 donor site mutation causes an abnormal splicing; exon 6 is spliced out with intron 6. The abnormal mRNA has a premature termination codon, as the result of a frameshift, and this instability may lead to degradation. Thus, there is a close relation between this mutation and the molecular pathogenesis of protein 4.2 deficiency.

Base Sequence↗
PubMed1995

Disposition of diadenosine 5',5"'-P1,P4-tetraphosphate (Ap4A) in rats.

The disposition of diadenosine 5'5"'-P1,P4-tetraphosphate (Ap4A), an endogenous dinucleotide, was investigated in rats. The degradation of Ap4A in rat plasma was very rapid and could be explained by a Michaelis-Menten equation: Km and Vmax values were 1.69 micrograms/ml and 4.32 micrograms/min/ml, respectively. Ap4A was degraded in rat plasma to ATP and AMP, but not to 2 ADP molecules, and these nucleotides were further degraded through adenosine. The degradations kinetics were examined. After intravenous bolus injection, Ap4A in plasma declined rapidly and the rate of elimination was dose-dependent: the biological half-life was about 3s at the dose of 1 mg/kg and was longer at 3 mg/kg. When Ap4A was administered by intravenous infusion (0.5 or 1.0 mg/kg/min), the plasma level rapidly reached a steady-state, which then rapidly declined after stopping the infusion.

Adenosine↗
PubMed1994

Foreign gene expression in marine cyanobacteria under pseudo-continuous culture.

Foreign gene expression in a marine cyanobacterium, Synechococcus NKBG 15041c, has been carried out in both batch and pseudo-continuous culture, using chloramphenicaol acetyltransferase (CAT) as a model peptide and the broad host range vector pKT230. CAT has been successfully expressed in marine cyanobacteria under kanamycin resistance gene promoter. Pseudo-continuous culture of these recombinant marine cyanobacteria has been done by varying the dilution rate. At a dilution rate between 0.01 to 0.02 h-1, highest productivity was achieved. Under these conditions, long-term pseudo-continuous culture of recombinant marine cyanobacteria was achieved for more than 600 h with CAT productivity 18-fold greater than that observed in batch culture.

Chloramphenicol O-Acetyltransferase↗
PubMed1993

Effects of the new calcium antagonist monatepil on cardiac function and myocardial oxygen supply and demand in animals.

The effects of monatepil ([(+/-)-N-(6,11-dihydrodibenzo[b,e]thiepin-11-yl)-4-(p-fluor ophenyl)-1- piperazinebutyramide]maleate, AJ-2615, CAS 103377-41-9), a new calcium antagonist, on cardiac function and myocardial oxygen supply and demand were examined. 1. Monatepil reduced the spontaneous beats of isolated rabbit atria at the concentration of 3 x 10(-6) and 10(-5) mol/l. Monatepil decreased the contractile force of papillary muscles in a concentration-dependent manner (3 x 10(-8)-10(-5) mol/l). 2. Monatepil (0.3 mg/kg i.v.) slightly decreased heart rate in anesthetized open-chest dogs. This drug (0.1, 0.3 mg/kg i.v.) increased cardiac output and decreased blood pressure and total peripheral resistance. Monatepil decreased left ventricular dP/dtmax and slightly increased left ventricular end-diastolic pressure. 3. Monatepil (0.1-1.0 mg/kg i.v.) did not affect the PR interval, QRS duration and QTc interval of electrocardiograms in anesthetized dogs, whereas diltiazem (0.3 and 1.0 mg/kg i.v.) markedly prolonged the PR interval. 4. Monatepil (0.1-0.3 mg/kg i.v.) increased coronary blood flow (CoBF) and decreased myocardial oxygen consumption (MOC) and extraction. 5. Monatepil and diltiazem showed almost the same effects on cardiac function and myocardial oxygen supply and demand, but the negative chronotropic and negative dromotropic effects of monatepil were less potent than those of diltiazem.

Anesthesia↗
PubMed1991

A new class of calcium antagonists. Synthesis and biological activity of 11-[(omega-aminoalkanoyl)amino]-6,6a,7,8,9,10,10a,11-octahydrodibenzo [b,e]thiepin derivatives.

A series of 11-[(omega-aminoalkanoyl)amino]-6,6a,7,8,9,10,10a,11- octahydrodibenzo[b,e]thiepin derivatives were prepared and found to be a structurally new class of calcium antagonists. The structure-activity relationship studies indicated that the optimum was (6aR*,10aR*,11R*)-11-[[4-[4-(4-fluorophenyl)-1- piperazinyl]butyryl] amino]-6,6a,7,8,9,10,10a,11-octahydrodibenzo[b,e]thiepin (31,pA2 8.16), which was superior to diltiazem (pA2 7.42) in calcium antagonistic activity. Compound 31 showed antihypertensive activity in anesthetized rats, without a significant effect on the heart rate. It had also antianginal effects in vasopressin-induced ST-depression and methacholine-induced ST-elevation testings in rats. These potencies of 31 were essentially equal to those of diltiazem.

Animals↗
PubMed1991

A new class of calcium antagonists. 2. Synthesis and biological activity of 11-[[4-[4-(4-fluorophenyl)-1-piperazinyl]butyryl]amino]-6,11- dihydrodibenzo[b,e]-thiepin maleate and related compounds.

A series of [(epsilon-aminoalkanoyl)amino]-6,11- dihydrodibenzo[b,e]thiepins and -5H-dibenzo[a,d]cycloheptenes and related compounds were synthesized and evaluated for calcium antagonistic activity by calcium-induced constriction of potassium-depolarized rat aorta. Semiempirical molecular orbital calculations of the dibenzotricyclic systems indicated that calcium antagonistic activity increased with a decrease of the angle between the planes of the two phenyl rings. AM1 net charge calculations showed that a neutral or positive charge distribution in the bridge portion was necessary for activity. 11-[[4-[4-(4-Fluorophenyl)-1- piperazinyl]butyryl]amino]-6,11-dihydrodibenzo[b,e]thiepin maleate (16, AJ-2615) showed a more gradual and longer lasting antihypertensive effect than diltiazem and nifedipine in spontaneously hypertensive rats (SHR) administered orally. Compound 16 also possessed antianginal effects in methacholine-induced ST elevation and vasopressin-induced ST depression tests in rats. The alteration of the dibenzotricyclic system of 16 to 5H-dibenzo[a,d]cycloheptene (19, 5-[[4-[4-(4-fluorophenyl)-1-piperazinyl]-butyryl]amino]-5H- dibenzo[a,d]cycloheptene) resulted in selectivity for cardiac tissue over vascular tissue, thereby conferring antianginal activity without an effect on blood pressure. Antianginal potencies of 16 and 19 were equal to or somewhat more potent than those of diltiazem.

Animals↗
PubMed1991

[Decreased cerebral blood flow in remote areas in deep-seated cerebrovascular lesions].

Recent positron or single photon emission computed tomographic studies have demonstrated that the impairment of regional hemodynamics or metabolism in cerebrovascular disease is not limited to the focal lesion, but also involves more remote areas. The present study evaluated cerebral blood flow in areas remote from the primary lesion in patients with subcortical cerebrovascular disease, and assessed correlations with the clinical features. Twenty patients aged 61-89 (mean, 74.7 +/- 6.7 years) were divided into the L group (lacunar infarction in deep penetrating arterial territory, n = 7), the NL group (non-lacunar subcortical infarction caused by main trunk occlusion or severe stenosis, n = 6), and the H group (putaminal or thalamic hemorrhage, n = 7). Ipsilateral cortical and contralateral cerebellar blood flow were assessed using single photon emission computed tomography with 123I-IMP. Although only some patients of the L group showed a mild reduction of ipsilateral cortical blood flow, most of the patients in the NL and H groups showed a moderate or severe flow reduction. The cortical blood flow reduction was suggested to be caused by several mechanisms, including brain edema, a decreased perfusion pressure associated with disease of large arteries, partial cortical neuronal damage, and deactivation. The degree of the flow reduction was considered to depend on the relative contribution of each of these factors. Contralateral cerebellar blood flow reduction, i.e., crossed cerebellar diaschisis, was observed more frequently and prominently in the NL and H groups than in the L group.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗