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A Narita

Publications and source records attributed to A Narita.

At least 19 recordsLinked to original sources
PubMed2006

Genome-wide linkage disequilibrium in two Japanese beef cattle breeds.

There is little knowledge about the degree of linkage disequilibrium (LD) in beef cattle. This study aims to perform a genome-wide search for LD in Japanese Black and Japanese Brown beef cattle and to compare the level of LD between these two breeds. Parameter D' (the LD coefficient) was used as a measure of LD, and LD was tested for significance of allelic associations between syntenic and between non-syntenic marker pairs. Effects of breed, chromosome, genetic map distance and their interactions with D' were tested based on least squares analyses. Both breeds showed high levels of LD, which ranged over several tens of cM and declined as the marker distance increased for syntenic marker pairs. A rapid decline of the D' value was observed between markers that were spaced 5 and 20 cM apart. LD was significant in most cases for marker pairs <40 cM apart but was not significant between non-syntenic loci. The pattern of LD found in these two breeds was similar to that previously published for dairy cattle. The D' value between breeds was not significantly different (P > 0.05), but the interaction between breed and chromosome was highly significant (P < 0.001). Genetic selection seems to have caused the heterogeneity of the D' values among chromosomes within breed. These results indicate that LD mapping is a useful tool for fine-mapping quantitative trait loci of economically important traits in Japanese beef cattle.

Alleles↗
PubMed2005

Genome-wide linkage analysis of mandibular prognathism in Korean and Japanese patients.

The existence of familial aggregation of mandibular prognathism (MP) suggests that genetic components play an important role in its etiology. In this study, a genome-wide linkage analysis to identify loci susceptible to MP was conducted with 90 affected sibling-pairs in 42 families, comprised of 40 Korean sibling-pairs and 50 Japanese sibling-pairs. Two non-parametric linkage analyses, GENEHUNTER-PLUS and SIBPAL, were applied and detected nominal statistical significance of linkage to MP at chromosomes 1p36, 6q25, and 19p13.2. The best evidence of linkage was detected near D1S234 (maximum Z(lr) = 2.51, P = 0.0012). In addition, evidence of linkage was observed near D6S305 (maximum Z(lr) = 2.23, P = 0.025) and D19S884 (maximum Z(lr) = 1.93, P = 0.0089). Identification of the susceptible genes in the linkage regions will pave the way for insights into the molecular pathways that cause MP, especially overgrowth of the mandible, and may lead to the development of novel therapeutic tools.

Adolescent↗
PubMed2001

Ca(2+)-induced switching of troponin and tropomyosin on actin filaments as revealed by electron cryo-microscopy.

Muscle contraction is regulated by the intracellular Ca(2+ )concentration. In vertebrate striated muscle, troponin and tropomyosin on actin filaments comprise a Ca(2+)-sensitive switch that controls contraction. Ca(2+ )binds to troponin and triggers a series of changes in actin-containing filaments that lead to cyclic interactions with myosin that generate contraction. However, the precise location of troponin relative to actin and tropomyosin and how its structure changes with Ca(2+ )have been not determined. To understand the regulatory mechanism, we visualized the location of troponin by determining the three-dimensional structure of thin filaments from electron cryo-micrographs without imposing helical symmetry to approximately 35 A resolution. With Ca(2+), the globular domain of troponin was gourd-shaped and was located over the inner domain of actin. Without Ca(2+), the main body of troponin was shifted by approximately 30 A towards the outer domain and bifurcated, with a horizontal branch (troponin arm) covering the N and C-terminal regions of actin. The C-terminal one-third of tropomyosin shifted towards the outer domain of actin by approximately 35 A supporting the steric blocking model, however it is surprising that the N-terminal half of tropomyosin shifted less than approximately 12 A. Therefore tropomyosin shifted differentially without Ca(2+). With Ca(2+), tropomyosin was located entirely over the inner domain thereby allowing greater access of myosin for force generation. The interpretation of three-dimensional maps was facilitated by determining the three-dimensional positions of fluorophores labelled on specific sites of troponin or tropomyosin by applying probabilistic distance geometry to data from fluorescence resonance energy transfer measurements.

Actins↗
PubMed2001

Molecular design of hairpin imidazole-pyrrole polyamide for effective DNA alkylation.

A new type of hairpin polyamide-CPI conjugate possessing a vinyl linker has been synthesized. Sequence-selective alkylation of double-stranded DNA by conjugates was investigated by high resolution denaturing gel electrophoresis using 450 bp DNA fragments. Highly-efficient DNA alkylation predominantly occurs at the purines of 5'-(A/T)G(T/A)CPu-3' site at nanomolar concentration.

Alkylation↗
PubMed2001

Identification of epistatic interactions involved in non-insulin-dependent diabetes mellitus in the Otsuka Long-Evans Tokushima Fatty rat.

The Otsuka Long-Evans Tokushima Fatty (OLETF) rat is an animal model for obese-type non-insulin-dependent diabetes mellitus (NIDDM) in humans. Our present investigation was designed to identify epistatic interactions influencing NIDDM by performing least squares analysis of variance of all pairs of informative markers in 160 F2 progenies bred from an intercross of OLETF and Fischer-344 rats. We identified four interactions between Nidd15/of (chromosome 7) and Nidd16/of (chromosome 14), Nidd15/of and Nidd17/of (chromosome 15), Nidd16/of and Nidd18/of (chromosome 15), and Nidd16/of and Nidd19/of (chromosome 17), which account for a total of approximately 40% of the genetic variation of entire glucose levels after glucose challenge in the F2. The Nidd16/of locus, which is involved in three of four digenic interactions, and the Nidd19/of are likely to correspond to Nidd2/of and Nidd14/of, NIDDM loci previously identified in the F2 by single-QTL model and multiple-QTL model, respectively, while Nidd15/of, Nidd17/of and Nidd18/of loci reflect novel NIDDM loci. An aberrant increase of the entire glucose level due to synergism occurs in the double OLETF homozygote genotype of Nidd15/of and Nidd16/of, and of Nidd16/of and Nidd19/of, as well as in the OLETF homozygote genotypes of Nidd15/of and Nidd16/of, respectively, combined with the heterozygote genotypes of Nidd17/of and Nidd18/of. These findings demonstrate that inter-allelic interactions are likely to be an important component of NIDDM susceptibility.

Animals↗
PubMed2001

Effects of long-term acidification of extracellular pH on ATP-induced calcium mobilization in rabbit lens epithelial cells.

ATP-induced calcium (Ca2+) mobilization was investigated in rabbit lens epithelial cells that had been cultured in a medium with pH of 7.4 (group 1), 7.2 (group 2), or 7.0 (group 3) for 10 to 21 d. Intracellular free Ca2+ ([Ca2+]i and pH (pHi) were measured by using fluorescent dyes, fura-2 and BCECF, respectively. The long-term acidification decreased the pHi to 7.15 +/- 0.01, from 7.22 +/- 0.01, in group 2 and to 7.09 +/- 0.01 in group 3. The administration of 10 micromol/l ATP produced an initial peak followed by a sustained increase in [Ca2+]i in the lens cells of group 1. Both the initial peak and the sustained increase in [Ca2+]i were enhanced in groups 2 and 3. The initial peak was abolished by pretreatment with 1 micromol/l thapsigargin, an ER Ca2+ pump inhibitor, but was not affected by the removal of extracellular Ca2+. On the other hand, the sustained increase was suppressed either by the thapsigargin treatment or by the Ca2+ removal. Treatment with only thapsigargin caused a sustained increase in [Ca2+]i that was greater in group 3 than in group 1. These results suggest that (1) the ATP-induced initial peak in [Ca2+]i is due to Ca2+ release from the intracellular stores, (2) the sustained increase in [Ca2+]i is mediated through either Ca2+ influx from the extracellular space or Ca2+ release from the store triggered by the Ca2+ influx, and (3) long-term, moderate acidification enhances both the initial peak and the sustained increase in [Ca2+)]i in rabbit lens epithelial cells. One possible mechanism of the ATP-induced Ca2+ influx seems to be a capacitative Ca2+ entry pathway.

Adenosine Triphosphate↗
PubMed2000

Cerebral blood flow on xenon CT: correlation with the blood flow detected at the common carotid artery on ultrasonography.

To correlate cerebral blood flow (CBF) on xenon CT with the flow at common carotid artery (CCA) detected by color doppler ultrasonography, 82 patients (29 men, 53 women; 20-90 yrs) were examined. They included normal volunteers (n = 33), patients with cerebral infarction (n = 8), multiple lacunar infarcts (n = 12), dementia (n = 14), and parkinson disease (n = 15). Flow at the CCA was graded as extremely low (< 0.3 l/min), low (0.3-0.4), and normal (> 0.4). CBF was measured in the following distribution: anterior, middle, posterior cerebral arteries (ACA, MCA, PCA); white matter border zones (BZ); basal ganglia (BA), thalamus in two slices. CBF may be reduced in the BZ, cortical and deep gray matter with extremely low flow at CCA. We suggest that color doppler ultrasonography may aid in triage of patients for further CBF evaluation. As some overlap in CBF exists between normal and diseased groups with respect to low flow at CCA, color doppler ultrasonography must be evaluated in combination with xenon CT to reflect cerebral blood flow.

Adult↗
PubMed2000

Dissociation of epistatic effects involved in fasting and postprandial hyperglycemia.

The Otsuka Long-Evans Tokushima Fatty (OLETF) rat is an animal model for obese-type non-insulin-dependent diabetes mellitus (NIDDM) in humans. Our previous study has identified four epistatic interactions between Niddel (chromosome 7) and 2/of (chromosome 14), Niddel and 3/of (chromosome 15), Nidde2 and 4/of (chromosome 15), and Nidde2 and 5/of (chromosome 17), which exerted effects on NIDDM, by performing least squares analysis of variance of all pairs of informative markers in 160 F2 progenies bred from the OLETF rat. In the present study, we found that the four interactions affect postprandial glucose metabolism, but not glucose levels during fasting states. In addition, we identified novel interactions between Nidde6 (chromosome 1) and 7/of (chromosome 13), and Nidde8 (chromosome 5) and 9/of (chromosome 19), which is involved in fasting glucose levels but not postprandial glucose levels. These findings demonstrate that distinction between genetic bases of fasting hyperglycemia and postprandial hyperglycemia is made by not only single main effect but also epistatic interaction effect of NIDDM loci.

Animals↗
PubMed1997

[Mantle cell lymphoma with multiple extranodal involvement].

A 79-year-old male was admitted to our hospital because of general fatigue and night sweat. Physical examination showed generalized superficial lymphadenopathy, marked splenomegaly, and tumors in the conjunctiva and the abdomen. Chest X-ray and computed tomography (CT) revealed pleural effusion and intrathoracic lymphadenopathy. Abdominal ultrasonography and CT showed hepatosplenomegaly and intraperitoneal tumors. Upper gastrointestinal fiberscopy revealed multiple polypoid lesions and ulcers in the duodenum and the stomach. Involvement of relatively small-sized lymphocytes with cleaved nuclei was identified in each biopsied specimen from a cervical lymph node, a tumor in the conjunctiva, gastrointestinal polypoid lesions, and the bone marrow. Surface marker analysis of abnormal lymphocytes in the bone marrow revealed that CD5, CD19, and CD20 were strongly positive, but CD23 was weakly positive. Although (11:14)(q13:q32) translocation was not identified by chromosome analysis of bone marrow cells, Northern blot analysis of bone marrow cells revealed overexpression of the PRAD1 oncogene. Diagnosis of mantle cell lymphoma (MCL) was made. Combination chemotherapy by cyclophosphamide and vincristine was not effective, but etoposide perorally given at a dose of 50 mg per day was effective. In MCL, extranodal involvement of a digestive tract and bone marrow is well known. This case suggests that involvement of multiple organs including lacrimal glands and pleura could be characteristic of MCL cells.

Abdominal Neoplasms↗
PubMed1996

The effectiveness of papilledema as an indicator of raised intracranial pressure in children with craniosynostosis.

Craniosynostosis management partially depends on the detection and treatment of elevated intracranial pressure (ICP). Examination for papilledema is considered to be the most reliable screening method for identifying raised ICP, but its effectiveness has not been defined. One hundred and twenty-two children with craniosynostosis who underwent funduscopic examinations and then Camino ICP monitoring were studied. All eye examinations were performed by an ophthalmologist after pharmacological pupillary dilation. Fifteen patients (12%) had papilledema. Subsequent ICP monitoring showed that the median ICP was 12.7 mm Hg, with 41 patients (34%) having elevated ICPs (> 15 mm Hg). Those with papilledema had higher ICPs (17.5 +/- 3.2 versus 12.7 +/- 5.5 mm Hg), were older (5.9 +/- 4.7 versus 1.9 +/- 2.6 years), and were more likely to have craniofacial syndromes (73 versus 41%) than those without papilledema (P < 0.05). Patients with both elevated ICPs and papilledema were older (5.9 +/- 4.7 versus 1.6 +/- 1.4 years) and more likely to have multiple-suture synostosis (92 versus 61%) than those with elevated ICPs and no papilledema (P < 0.05). The presence of papilledema was a specific (98%) indicator of raised ICP, but its sensitivity was age-dependent. It was 100% sensitive in children older than 8 years, but it indicated elevated ICP in only 22% of younger patients. These results suggest that ICP monitoring to document elevated ICP is unnecessary in children older than 8 years who have detailed ophthalmological examinations. In the younger child, the presence of papilledema reliably indicates elevated ICP but its absence does not rule out elevated ICP; formal ICP measurement has a greater role in detecting elevated ICP in these patients.

Adolescent↗
PubMed1996

Forskolin derivatives. I. Synthesis, and cardiovascular and adenylate cyclase-stimulating activities of water-soluble forskolins.

Water-soluble forskolin and 7-deacetylforskolin derivatives with an aminoacetyl, a 3-aminopropionyl, or a 4-aminobutyryl group at the 6- or 7-position were prepared, and their positive inotropic as well as vasodilative activities were evaluated in anesthetized dogs. 7-Deacetylforskolin (2) and 7-deacetyl-1-silylforskolin (6) were converted to the corresponding 7-chloroacylderivatives (3, 7, 10), which were reacted with amines to obtain 7-aminoacyl-7-deacetylforskolins (4a-f, 9a, b, 11). The 7-acyl substituents migrated to the 6-position with sodium hydroxide in acetonitrile-water to afford 6-aminoacyl-7-deacetylforskolins (12a-f). The 7-position of 12a, d-f was selectively acetylated with acetyl chloride to obtain the corresponding 6-aminoacylforskolins (13a-d). Among the 6-aminoacylforskolins, 6-(3-dimethylaminopropionyl)forskolin (13b) and 6-(4-dimethylaminobutyryl)forskolin (13d) exhibited potent positive inotropic and vasodilative activities comparable to those of forskolin (1). The activities of 13b and 13d were approximately ten times more potent than those of 7-aminoacyl- and 6-aminoacyl-7-deacetylforskolins (4a-f, 9a, 12a-c, f). 6-Dimethylaminoacetylforskolin (13a) and 6-(3-diethylaminopropionyl)forskolin (13c) were less potent than 1. The effects of the soluble forskolins on adenylate cyclase activity were also examined in vitro. 6-Aminoacylforskolins (13a-d) exhibited potent adenylate cyclase-stimulating activity, comparable to that of 1.

Adenylyl Cyclases↗
PubMed1996

[CABG operation with sequential bypass using arterial grafts].

We evaluated 39 cases where sequential anastomoses had been performed using arterial graft (AG) in coronary artery bypass grafting (CABG). Fourty three AGs were used, and anastomosed to 87 coronary arterial branches. The details of these anastomoses were: 25 right gastroepiploic arteries (RGEA) to 51 branches; 10 left internal thoracic arteries (LITA) to 20 branches; 8 right internal thoracic arteries (RITA) to 16 branches. The interrupted suture was employed for all anastomoses. The proxymal site was initially anastomosed in the parallel way to a native coronary artery, and then, the distal anastomosis was done. In CABG using RGEA, the number of cases receiving anastomoses to RCA and LCX was the largest as in 13 cases, and the patent rate was favorable. There were also 8 cases of anastomoses to LAD and Dx and these GEA'S grafts were all patent. But, in the 2 cases of astomoses to RCA and LAD, the GEA's grafts between RCA and LAD were occluded. Therefore, this combination was thought to be inadequate for sequential hypass. On the other hand, in the 10 cases using LITA, these grafts were all anastomosed to LCA system, and were all patent. In the 8 cases using RITA, 4 in-situ grafts and 4 free grafts were employed. There were 3 anastomoses to LAD and D1 in the former, and 2 cases each of anastomoses to LAD and D1, and LCx (segment 12) in the latter. The patency was excellent, 100%. Although there were 1 case of post-operative early death (renal failure) and 1 case of remote death (cerebral infarction), they were found not due to arterial sequential bypass. In the 37 cases of post-operative angiography, patency was recognized in 40 AGs out of the 41 (97.6%) and 78 anastomosed branches out of the 83 (94.0%). These satisfactory findings indicate that it is possible and effective to perform sequential bypass in multivessel GABG using AG.

Adult↗
PubMed1995

Overexpression of the PRAD1 oncogene in a patient with prolymphocytic leukemia with t(11;14)(q13;q32).

Prolymphocytic leukemia (PLL) was diagnosed by morphologic and immunophenotypical studies in a 72-year-old Japanese man. Massive splenomegaly was present but lymphadenopathy was minimal in this case. Chromosomal analysis of peripheral mononuclear cells showed t(11;14)(q13;q32) in all metaphases examined, except for one normal karyotype. Northern blot analysis of RNA prepared from leukemic cells obtained from the patient revealed overexpression of the PRAD1/cyclin D1 proto-oncogene, which has not been described previously in patients with PLL.

Aged↗
PubMed1995

Overexpression of the PRAD1 oncogene in a patient with multiple myeloma and t(11;14)(q13;q32).

The t(11;14)(q13;q32) chromosomal translocation is associated with several B-cell lymphoproliferative disorders and is thought to result in upregulation of expression of PRAD1/cyclin D1 proto-oncogene. A patient with multiple myeloma of IgG kappa-type with t(11;14)(q13;q32) is now shown to overexpress PRAD1. The clinical stage of the disease was advanced (IIIA), with a myeloma cell count of 94.6% in the bone marrow. Chromosomal analysis of bone marrow cells showed t(11;14)(q13;q32) in five of 20 metaphases as well as other karyotypic features. Northern blot analysis of RNA prepared from myeloma cells revealed overexpression of PRAD1. Multiple myeloma with t(11;14)(q13;q32) has been associated with an aggressive clinical course. Although neither myeloma cells in the peripheral blood nor extramedullary lesions were apparent in the present patient, the myeloma was refractory to several chemotherapeutic regimens from the beginning. Detection of PRAD1 expression may offer an easier alternative to cytogenetic analysis in myeloma and is a potentially useful indicator of a poor prognosis.

Blotting, Northern↗
PubMed1995

[The potential of anastomosis of the gastroepiploic artery to the left anterior descending artery in coronary artery bypass grafting].

It would be a great contribution in coronary artery bypass grafting (CAGB) using arterial graft (AG) if right gastroepiploic artery (GEA) could be grafted onto left anterior descending artery (LAD) in situ. In this study, we discussed 22 cases where anastomosis of GEA to LAD was made in situ. The subjects were limited to high stenotic cases of > 90% stenosis or more > 75% stenoses recognized in the proximal segment of coronary artery from the anastomosed site. The sex ratio of 18 (male): 4 (female) and the age varied from 40 to 78 years (the mean age: 58 years). The details were 2 cases of single CABG, 6 cases of double CABG, 11 cases of triple CABG and 3 cases of quadruple CABG and 22 GEA's were anastomosed onto 32 vessels. There was no operative death. Postoperative angiography performed on the 21 cases showed the patency of 95.2% (20/21). These finding indicate that the use of GEA is effective for multivessel CABGs in LAD.

Aged↗