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Biomedical subjects

N Abe

Publications and source records attributed to N Abe.

At least 19 recordsLinked to original sources
PubMed2006

Subtype analysis of Cryptosporidium parvum isolates from calves on farms around Belgrade, Serbia and Montenegro, using the 60 kDa glycoprotein gene sequences.

Cryptosporidium parvum is composed of multiple subtypes, which appear to be zoonotic or anthroponotic. Therefore, in order to understand the molecular epidemiology of this species and to control the zoonotic transmission, it is essential to identify the isolates at the subtype level. In the present study, 60.2% of 103 examined dairy calves from 10 farms in the Belgrade area were positive for Cryptosporidium infection by PCR, and all of them were identified as C. parvum by PCR-RFLP of SSUrRNA and COWP genes. Eighteen C. parvum isolates selected randomly from 9 positive farms were classified by molecular phylogenetic analysis of the 60 kDa glycoprotein gene sequences into 3 subtype allele families, IIa and IId, which are known to be zoonotic, and a new family IIj. Furthermore 10 isolates in IIa were classified into 3 subtypes IIaA16G1R1b, IIaA18G1R1, IIaA20G1R1, 2 in IId into IIdA18G1b, and 6 in IIj into IIjA16R2 and IIjA17R2. The last 2 subtypes in IIa and 2 subtypes in IIj were new subtypes. These results suggest that C. parvum isolates harboured in calves in the Belgrade area have zoonotic potential and C. parvum is genetically diverse only in a limited area. This is the first molecular epidemiological report about Cryptosporidium infection in Serbia and Montenegro.

Animals↗
PubMed2006

Ferroelectric polarization flop in a frustrated magnet MnWO4 induced by a magnetic field.

The relationship between magnetic order and ferroelectric properties has been investigated for MnWO4 with a long-wavelength magnetic structure. Spontaneous electric polarization is observed in an elliptical spiral spin phase. The magnetic-field dependence of electric polarization indicates that the noncollinear spin configuration plays a key role for the appearance of the ferroelectric phase. An electric polarization flop from the b direction to the a direction has been observed when a magnetic field above 10 T is applied along the b axis. This result demonstrates that an electric polarization flop can be induced by a magnetic field in a simple system without rare-earth 4f moments.

Journal Article↗
PubMed2005

Molecular characterization of Anisakis pegreffii larvae in Pacific cod in Japan.

It is now recognized that the morphospecies Anisakis simplex is not a single species but a complex composed of three sibling species, A. simplex sensu stricto, A. pegreffii and A. simplex C. In Japan, A. simplex-like larvae have been isolated from a variety of fish and humans, but the larvae collected have been identified as A. simplex by only light microscopy. Therefore, the epidemiology of the A. simplex complex, composed of three sibling species, is still unclear in Japan. In the present study, 26 A. simplex-like larval isolates were obtained from two Pacific cod landed in Hokkaido, Japan, and examined genetically by PCR-RFLP and direct sequencing of the ITS region of rDNA. Among the 26 isolates, 24 were identified as A. simplex sensu stricto, the other two as A. pegreffii. The present study is the first to confirm the distribution of A. pegreffii in Japan, and to detect A. pegreffii larvae in Pacific cod.

Animals↗
PubMed2004

Evidence for direct CP violation in B0-->K+pi- decays.

We report evidence for direct CP violation in the decay B0-->K+pi(-) with 253 fb(-1) of data collected with the Belle detector at the KEKB e(+)e(-) collider. Using 275x10(6) BB pairs we observe a B-->K+/-pi(-/+) signal with 2140+/-53 events. The measured CP violating asymmetry is A(CP)(K+pi(-))=-0.101+/-0.025(stat)+/-0.005(syst), corresponding to a significance of 3.9sigma including systematics. We also search for CP violation in the decays B+-->K+pi(0) and B+-->pi(+)pi(0). The measured CP violating asymmetries are A(CP)(K+pi(0))=0.04+/-0.05(stat)+/-0.02(syst) and A(CP)(pi(+)pi(0))=-0.02+/-0.10(stat)+/-0.01(syst), corresponding to the intervals -0.05<A(CP)(K+pi(0))<0.13 and -0.18<A(CP)(pi(+)pi(0))<0.14 at 90% confidence level.

Journal Article↗
PubMed2004

Observation of large CP violation and evidence for direct CP violation in B0-->pi(+)pi(-) decays.

We report the first observation of CP violation in B0-->pi(+)pi(-) decays based on 152x10(6) gamma (4S)-->BB decays collected with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. We reconstruct a B0-->pi(+)pi(-) CP eigenstate and identify the flavor of the accompanying B meson from its decay products. From the distribution of the time intervals between the two B meson decay points, we obtain A(pipi)=+0.58+/-0.15(stat)+/-0.07(syst) and S(pipi)=-1.00+/-0.21(stat)+/-0.07(syst). We rule out the CP-conserving case, A(pipi)=S(pipi)=0, at a level of 5.2 standard deviations. We also find evidence for direct CP violation with a significance at or greater than 3.2 standard deviations for any S(pipi) value.

Journal Article↗
PubMed2004

Endoscopic retreatment of recurrent choledocholithiasis after sphincterotomy.

BACKGROUND: Endoscopic sphincterotomy (ES) carries a substantial risk of recurrent choledocholithiasis but retreatment with endoscopic retrograde cholangiopancreatography (ERCP) is safe and feasible. However, long term results of repeat ERCP and risk factors for late complications are largely unknown. AIMS: To investigate the long term outcome of repeat ERCP for recurrent bile duct stones after ES and to identify risk factors predicting late choledochal complications. METHODS: Eighty four patients underwent repeat ERCP, combined with ES in 69, for post-ES recurrent choledocholithiasis. Long term outcomes of repeat ERCP were retrospectively investigated and factors predicting late complications were assessed by multivariate analysis. RESULTS: Complete stone clearance was achieved in all patients. Forty nine patients had no visible evidence of prior sphincterotomy. Two patients experienced early complications. During a follow up period of 2.2-26.0 years (median 10.9 years), 31 patients (37%) developed late complications, including stone recurrence (n = 26), acute acalculous cholangitis(n = 4), and acute cholecystitis (n = 1). There were neither biliary malignancies nor deaths attributable to biliary disease. Multivariate analysis identified three independent risk factors for choledochal complications: interval between initial ES and repeat ERCP < or =5 years, bile duct diameter > or =15 mm, and periampullary diverticulum. Choledochal complications were successfully treated with repeat ERCP in 29 patients. CONCLUSIONS: Choledochal complications after repeat ERCP are relatively frequent but are endoscopically manageable. Careful follow up is necessary, particularly for patients with a dilated bile duct, periampullary diverticulum, or early recurrence. Repeat ERCP is a reasonable treatment even for recurrent choledocholithiasis after ES.

Adult↗
PubMed2003

An increased high-mobility group A2 expression level is associated with malignant phenotype in pancreatic exocrine tissue.

The altered form of the high-mobility group A2 (HMGA2) gene is somehow related to the generation of human benign and malignant tumours of mesenchymal origin. However, only a few data on the expression of HMGA2 in malignant tumour originating from epithelial tissue are available. In this study, we examined the HMGA2 expression level in pancreatic carcinoma, and investigated whether alterations in the HMGA2 expression level are associated with a malignant phenotype in pancreatic tissue. High-mobility group A2 mRNA and protein expression was determined in eight surgically resected specimens of non-neoplastic tissue (six specimens of normal pancreatic tissue and two of chronic pancreatitis tissue) and 27 pancreatic carcinomas by highly sensitive reverse transcriptase-polymerase chain reaction (RT-PCR) techniques and immunohistochemical staining, respectively. Reverse transcriptase-polymerase chain reaction analysis revealed the expression of the HMGA2 gene in non-neoplastic pancreatic tissue, although its expression level was significantly lower than that in carcinoma. Immunohistochemical analysis indicated that the presence of the HMGA2 gene in non-neoplastic pancreatic tissue observed in RT-PCR reflects its abundant expression in islet cells, together with its focal expression in duct epithelial cells. Intense and multifocal or diffuse HMGA2 immunoreactivity was noted in all the pancreatic carcinoma examined. A strong correlation between HMGA2 overexpression and the diagnosis of carcinoma was statistically verified. Based on these findings, we propose that an increased expression level of the HMGA2 protein is closely associated with the malignant phenotype in the pancreatic exocrine system, and accordingly, HMGA2 could serve as a potential diagnostic molecular marker for distinguishing pancreatic malignant cells from non-neoplastic pancreatic exocrine cells.

Carcinoma↗
PubMed2003

Studies of the decay B+/- -->D(CP)K+/-.

We report studies of the Cabibbo-suppressed decay B+/--->D(CP)K+/-, where D(CP) denotes CP eigenstates of the D0-D0; system. The analysis is based on a 29.1 fb(-1) sample collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric e(+)e(-) storage ring. We measure ratios of branching fractions, relative to Cabibbo-favored B+/--->D(CP)pi(+/-), of B(B--->D1K-)/B(B--->D1pi(-))=0.125+/-0.036+/-0.010 and B(B--->D2K-)/B(B--->D2pi(-))=0.119+/-0.028+/-0.006; the index 1 (2) denotes the CP=+1 (-1) eigenstate. We also extract the partial rate asymmetries for B+/--->D(CP)K+/-, finding A(1)=0.29+/-0.26+/-0.05 and A(2)=-0.22+/-0.24+/-0.04.

Journal Article↗
PubMed2003

Predictive factors for malignancy in intraductal papillary-mucinous tumours of the pancreas.

BACKGROUND: Preoperative assessment of the likelihood of malignancy in intraductal papillary-mucinous tumour (IPMT) of the pancreas is often difficult. Predictive factors for malignancy and invasive carcinoma in IPMT were analysed. METHODS: Sixty-two patients with IPMT underwent surgical treatment, with histological confirmation of adenoma in 28, carcinoma in situ in 14 and invasive carcinoma in 20. Tumours were of the main duct type in 14 patients, branch duct type in 32, and combined type in 16. A multivariate analysis of 17 potential predictive factors, including preoperative clinical and imaging findings, was conducted. RESULTS: Multivariate analysis identified two independent predictive factors for malignancy: mural nodules and main pancreatic duct diameter of 7 mm or more. Mural nodules in the main duct or combined type, and mural nodules and tumour diameter of 30 mm or more in the branch duct type were particularly indicative of malignancy. Mural nodules, jaundice and main duct or combined type were predictors of invasive carcinoma in the multivariate analysis. CONCLUSION: The above factors should be considered in the diagnosis of IPMT to facilitate appropriate management.

Adenocarcinoma, Mucinous↗
PubMed2002

Observation of B+/- -->omegaK+/- decay.

We report the first observation of the charmless two-body mode B+/--->omegaK+/- decay, and a new measurement of the branching fraction for the B+/--->omegapi(+/-) decay. The measured branching fractions are B(B+/--->omegaK+/-)=(9.2(+2.6)(-2.3)+/-1.0)x10(-6) and B(B+/--->omegapi(+/-))=(4.2(+2.0)(-1.8)+/-0.5)x10(-6). We also measure the partial rate asymmetry of B+/--->omegaK+/- decays and obtain A(CP)=-0.21+/-0.28+/-0.03. The results are based on a data sample of 29.4 fb(-1) collected on the Upsilon(4S) resonance by the Belle detector at the KEKB e(+)e(-) collider.

Journal Article↗
PubMed2001

Possible contribution of CD44 variant 6 and nuclear beta-catenin expression to the formation of budding tumor cells in patients with T1 colorectal carcinoma.

BACKGROUND: In an earlier study, the authors demonstrated that tumor budding was useful for predicting lymph node metastasis in patients with early invasive (T1) colorectal carcinoma. This study was undertaken to clarify the associations between tumor budding, E-cadherin-catenin complex, and CD44 variant 6 abnormalities. METHODS: In 51 T1 colorectal carcinomas, tumor budding (the number of dedifferentiation units at the invasive margin) on hematoxylin and eosin-stained slides was counted under light microscopy. Immunostaining for E-cadherin, alpha-catenin, beta-catenin, and CD44 variant 6 was performed on formalin fixed, paraffin embedded sections. The associations between locoregional failure (lymph node metastasis or local recurrence) and tumor budding and clinicopathologic parameters and immunoreactivity were examined statistically. RESULTS: In univariate analysis, tumor budding and nuclear beta-catenin expression were associated significantly with locoregional failure (P = 0.004, 0.01). Multivariate analysis showed that tumor budding alone was associated significantly with locoregional failure (P = 0.02), and the association between nuclear beta-catenin expression and locoregional failure was marginally significant (P = 0.07). Analysis of variance showed that lymphatic invasion alone was associated significantly with tumor budding (P = 0.02), and there was a significant interaction effect for tumor budding between CD44 variant 6 expression and nuclear beta-catenin expression (P = 0.01). There was a significant correlation between expression patterns of these two molecules and locoregional failure (P = 0.01). CONCLUSIONS: The current results suggest that the up-regulation of CD44 variant 6 through nuclear beta-catenin activation may contribute to the formation of tumor budding, and immunostaining of these two adhesion molecules may be useful in identifying those at high-risk for locoregional failure among patients with T1 colorectal carcinoma.

Adult↗
PubMed2001

Overexpression of AML1 transcription factor drives thymocytes into the CD8 single-positive lineage.

To understand the gene regulation involved in the development of single-positive (SP) thymocytes, we generated transgenic mice in which the AML1 transcription factor is overexpressed. In these mice the number of CD8 SP thymocytes was greatly increased, and this continued to be true even when MHC class I was absent. This promotion to the CD8 SP lineage was not, however, observed when both class I and class II were absent. Furthermore, even thymocytes carrying MHC class II-restricted TCR differentiated into the CD8 SP lineage when AML1 was overexpressed. The selected CD8 SP cells were, however, unable to mature, as judged by the expression level of heat-stable Ag. Thus, overexpression of AML1 is able to skew class II-restricted thymocytes into the CD8 SP lineage, but not to drive the maturation of resulting selected CD8 SP cells.

Animals↗
PubMed2001

Multivariable control of alcohol concentrations in the production of polyhydroxyalkanoates (PHAs) by Paracoccus denitrificans.

A novel multivariable control strategy is developed for alcohol (ethanol and n-pentanol) concentrations in the production of poly(3-hydroxybutyrate-co-3-hydroxyvalerate), P(HB-co-HV), a biodegradable polymer by Paracoccus denitrificans ATCC 1774. This controller, which is developed to control the mole fraction of P(HB-co-HV), consists of two parts: one is for ethanol concentration control and the other is for mole fraction control, based on the concept of metabolic flux distribution control. A simple metabolic reaction (MR) model is constructed for flux distribution analysis. The relationship between mole ratio of specific consumption rate of the two alcohols (ethanol and n-pentanol) and the mole fraction of 3HV units in the polymer is linear. This result suggests that the split ratio at a branched point of 3-ketovaleryl-CoA in the P(HB-co-HV) synthetic pathway is constant for several fermentation conditions. When the mole fraction of 3HV units has a target value, the feed rate of n-pentanol becomes a function of the feed rate of ethanol and the set value of 3HV, based on the MR model. The mole fraction of 3HV units successfully reached the target value using this strategy. The mole fraction control strategy is combined with an optimal production strategy based on the optimal profile of the specific growth rate. The combined strategy is realized using multivariable controllers and P(3HB-co-3HV) production is maximized with a given value of mole fraction of 3HV units at the final step of fermentation.

Acyl Coenzyme A↗
PubMed2001

Matrilysin (MMP-7) as a significant determinant of malignant potential of early invasive colorectal carcinomas.

Matrix metalloproteinases play a crucial role in tumour invasion and metastasis. Matrilysin (MMP-7) has been shown to correlate with nodal or distant metastasis in colorectal carcinomas; however, its implication in early invasive colorectal carcinomas has not been determined. This study was undertaken to clarify the association of matrilysin expression with clinicopathologic parameters in early invasive colorectal carcinomas. 38 early invasive colorectal carcinomas treated by local excision or radical surgery were examined. Tumour budding was evaluated as the number of dedifferentiation units along the entire invasive margin. Matrilysin protein levels were determined using immunohistochemical study. Univariate analysis showed that matrilysin expression alone was significantly associated with distant metastasis (P = 0.0339), and both tumour budding and matrilysin expression were significantly associated with adverse outcome (P = 0.0005, 0.0341). Histological differentiation, vessel invasion, and depth of invasion were not significantly associated with either distant metastasis or adverse outcome. Multivariate analysis confirmed that tumour budding and matrilysin expression were independently associated with adverse outcome, although the significance of matrilysin expression was marginal (P = 0.0488). Tumour budding at the invasive margin and matrilysin expression are more useful in identifying high-risk groups for adverse outcome in patients with early invasive colorectal carcinomas.

Aged↗
PubMed2001

High mobility group HMGI(Y) protein expression in human colorectal hyperplastic and neoplastic diseases.

HMGI(Y) proteins are overexpressed in experimental and human malignancies, including colon, prostate and thyroid carcinomas. To determine at which step of the carcinogenic process HMGI(Y) induction occurs, we analysed the expression of the HMGI(Y) proteins in hyperplastic, preneoplastic and neoplastic tissues of colorectal origin by immunohistochemistry. All the colorectal carcinomas were HMGI(Y)-positive, whereas no expression was detected in normal colon mucosa tissue. HMGI(Y) expression in adenomas was closely correlated with the degree of cellular atypia. Only 2 of the 18 non-neoplastic polyps tested were HMGI(Y)-positive. These data indicate that HMGI(Y) protein induction is associated with the early stages of neoplastic transformation of colon cells and only rarely with colon cell hyperproliferation.

Adenoma↗
PubMed2001

The indication of local excision for T2 rectal carcinomas.

BACKGROUND: Several researchers reported that local excision with or without postoperative chemo-radiation therapy is an alternative approach for sphincter preservation in patients with locally invasive rectal carcinoma. However, indications and long-term results have not yet been determined. METHODS: Seventy-two patients with T2 colorectal carcinomas underwent bowel resection with regional lymph node dissection. The associations between lymph node metastasis (LNM) and clinicopathologic factors were examined with special reference to the presence or absence of moderate to severe degree of focal dedifferentiation or mucinous component at the invasive margin (unfavorable histology). RESULTS: Multivariate logistic regression analysis revealed that both sex and unfavorable histology were significantly associated with LNM (P = 0.0102, 0.0226, respectively). However, the associations between LNM and lymphatic invasion or tumor location were not statistically significant (P = 0.0947, 0.1738). CONCLUSIONS: When locally resected T2 rectal carcinoma specimens have unfavorable histology at the invasive margin, additional bowel resection with lymph node dissection should be recommended.

Colorectal Neoplasms↗