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Biomedical subjects

Y Takahashi

Publications and source records attributed to Y Takahashi.

At least 19 recordsLinked to original sources
PubMed2006

Spindle cell carcinoma arising in the pharynx, with granulocytosis and high serum granulocyte colony stimulating factor titre.

We report the case of a 67-year-old man with a left pharyngeal tumour, whose peripheral blood showed granulocytosis (white blood cell count, 58,300/microl) and a high serum granulocyte colony stimulating factor titre (184 pg/ml). The tumour showed pleomorphic proliferation of atypical spindle cells in a myxomatous stroma, revealing a sarcomatous pattern. The spindle-shaped neoplastic cells had irregularly shaped nuclei, a thick nuclear membrane, prominent eosinophilic nucleoli and abundant cytoplasm. They strongly expressed wide-spectrum keratin, cytokeratins (CAM5.2, MNF116), vimentin and vascular endothelial growth factor. A few neoplastic cells expressed granulocyte colony stimulating factor. A spindle cell carcinoma was diagnosed. This may be the first documented case of a granulocyte colony stimulating factor producing cancer arising in the pharynx. The patient died four months after the initial symptoms appeared.

Aged↗
PubMed2006

Association between dietary fiber, water and magnesium intake and functional constipation among young Japanese women.

OBJECTIVE: Most research on constipation has focused on dietary fiber intake. Here, we examined the intake of water and magnesium, nutrients possibly associated with constipation, as well as that of dietary fiber in relation to constipation. DESIGN: Cross-sectional study. SUBJECTS: A total of 3835 female Japanese dietetic students aged 18-20 years from 53 institutions in Japan. METHODS: Dietary intake was estimated with a validated, self-administered diet history questionnaire. Functional constipation was defined using the Rome I criteria. RESULTS: The prevalence of functional constipation was 26.2%. Neither dietary fiber intake (mean=6.4 g/4186 kJ) nor intakes of total water and water from fluids were associated with constipation. Conversely, low intake of water from foods was associated with an increasing prevalence of constipation. In comparison with women in the first (lowest) quintile, the multivariate adjusted odds ratio (OR) (95% confidence interval (CI)) for women in the second, third, fourth, and fifth quintiles were 0.72 (0.57, 0.90), 0.78 (0.62, 0.98), 0.71 (0.56, 0.89), and 0.77 (0.61, 0.97), respectively (P for trend=0.04). Additionally, low magnesium intake was associated with increasing prevalence of constipation. Compared with women in the first quintile, the multivariate adjusted OR (95% CI) for women in the second, third, fourth and fifth quintiles were 0.70 (0.56, 0.88), 0.75 (0.60, 0.95), 0.73 (0.58, 0.92) and 0.79 (0.63, 0.996), respectively (P for trend=0.09). CONCLUSIONS: Low intakes of water from foods and magnesium are independently associated with an increasing prevalence of functional constipation among a population whose dietary fiber intake is relatively low.

Adolescent↗
PubMed2006

Fate of cystic ovarian follicles and the subsequent fertility of early postpartum dairy cows.

The fate of cystic ovarian follicles that developed spontaneously during the early postpartum period of 50 lactating dairy cows was traced by ultrasonography to characterise the follicular dynamics in relation to the fertility of the cows. The absence of postpartum ovulations caused by repeated waves of anovulatory large follicles was also characterised and evaluated. Fifteen of the 50 cows developed cystic follicles, and these follicles became follicular cysts in five of the 15 cows. Most of the cystic follicles emerged before the first postpartum ovulation of the cows. The transition from cystic follicles to follicular cysts delayed the cows' first ovulation, oestrus and insemination, but had less influence on their fertility after they had recovered spontaneously. In addition to the 15 cows that developed cystic follicles or follicular cysts, six of the cows had five to 13 waves of follicles before their first ovulation. These repeated waves of follicles caused a more severe delay in the early postpartum reproductive events but did not affect the cows' fertility.

Animals↗
PubMed2006

Molecular cloning and characterization of an Rcd1-like protein in excretory-secretory products of Trichinella pseudospiralis.

A cDNA library was constructed from muscle larvae of Trichinella pseudospiralis. A cDNA clone, designated as Tp8 contained a cDNA transcript of 1326 bp length with a single open reading frame, which encoded 303 amino acid residues (34,187 Da, estimated molecular mass). The predicted amino acid sequence of the clone had an identity of approximately 60% to the Rcd1 (Required cell differentiation 1) -like proteins among a wide range of organisms. Real-time quantitative polymerase chain reaction results showed that the transcription level of Tp8 gene reached the highest value in adult worms, and that the transcription level in muscle larvae before stichosome formation was higher than in muscle larvae after stichosome formation. The recombinant Tp8 protein migrated at 37 kDa and reacted to antibody against T. pseudospiralis excretory-secretory (E-S) products and sera from mice infected with T. pseudospiralis. An antibody against the Tp8 recombinant protein could stain proteins migrating at approximately 34 kDa (which is the expected size from the sequence) on Western blotting of E-S products from muscle larvae. An immunocytochemical study showed that the Tp8 protein was present within the stichocyte of muscle larvae and adults worms.

Amino Acid Sequence↗
PubMed2006

Risk factors for de novo acute cardiac events in patients initiating hemodialysis with no previous cardiac symptom.

An initial major adverse cardiac event (MACE) is an important predictor of future cardiovascular events in patients with chronic kidney disease (CKD). We sought to identify factors influencing occurrence of initial MACE in new maintenance hemodialysis patients without previous cardiac symptoms during the predialysis phase of CKD. Among 112 participating patients with no predialysis cardiac history, 57 underwent coronary angiography, whereas the other 55 underwent stress thallium-201 single-photon emission computed tomography within 1 month of beginning hemodialysis to detect asymptomatic coronary artery disease (CAD). In subsequent follow-up for a median of 24 months, subjects experiencing an initial MACE were compared with those who did not have such an event based on several clinical parameters at the end of predialysis phase. Asymptomatic CAD was present in 47 patients (42%), who had a higher cumulative MACE rate, than subjects without CAD (49 vs 3%, P<0.001). Multivariate Cox's regression analysis showed that three variables independently predicted initial MACE: asymptomatic CAD (hazard ratio or HR, 611.31; 95% confidence interval or CI, 14.07-26549.23; P<0.001), diabetes (HR, 20.41; 95% CI, 2.07-200.00; P=0.010), and each 1 mg/l increment in C-reactive protein (CRP) (HR, 1.94; 95% CI, 1.27-2.94; P=0.002). In conclusion, detection of asymptomatic CAD, presence of diabetes, or elevated CRP at the end of the predialysis phase were significantly associated with occurrence of an initial MACE in CKD patients starting hemodialysis who had no CAD symptoms.

Aged↗
PubMed2006

Involvement of the c-Ski oncoprotein in cell cycle arrest and transformation during nurse cell formation after Trichinella spiralis infection.

The role of c-Ski, an oncoprotein encoded by the oncogene, c-ski, in Trichinella spiralis-infected muscle tissues during nurse cell formation, was investigated by following the expression kinetics and distribution of c-Ski (both protein and mRNA) in the infected muscle cell, as well as the expression kinetics of the transforming growth factor beta (TGF-beta) signaling pathway factor genes (TGF-beta, Smad2 and Smad4) which cooperate with c-Ski. Immunohistochemical analysis using an anti-c-Ski antibody indicated that in the early stages of infection (13 and 18 days post-infection (p.i.)) the increased expression of the c-Ski protein was limited to the eosinophilic cytoplasm and not the enlarged nuclei or basophilic cytoplasm. At a later stage of infection (23 and 28 days p.i.) the c-Ski protein was limited to the enlarged nuclei in the basophilic cytoplasm, rather than the eosinophilic cytoplasm. At 48 days p.i., the c-Ski protein was barely detectable. Real-time PCR analysis showed that expression of the c-ski gene increased from 13 days p.i., reached a peak at 23-28 days p.i. and then decreased to a low level by 48 days p.i. Expression kinetics for the TGF-beta signaling pathway factor genes (TGF-beta, Smad2 and Smad4) were similar to that of c-ski. These findings provide evidence that the c-Ski protein is involved in nurse cell formation through the TGF-beta signaling pathway process in the host cell nucleus.

Animals↗
PubMed2006

Valley polarization in Si(100) at zero magnetic field.

The valley splitting, which lifts the degeneracy of the lowest two valley states in a SiO(2)/Si(100)/SiO(2) quantum well, is examined through transport measurements. We demonstrate that the valley splitting can be observed directly as a step in the conductance defining a boundary between valley-unpolarized and -polarized regions. This persists to well above liquid helium temperature and shows no dependence on magnetic field, indicating that single-particle valley splitting and valley polarization exist in (100) silicon even at zero magnetic field.

Journal Article↗
PubMed2006

Periventricular heterotopia: phenotypic heterogeneity and correlation with Filamin A mutations.

Periventricular heterotopia (PH) occurs when collections of neurons lay along the lateral ventricles or just beneath. Human Filamin A gene (FLNA) mutations are associated with classical X-linked bilateral periventricular nodular heterotopia (PNH), featuring contiguous heterotopic nodules, mega cisterna magna, cardiovascular malformations and epilepsy. FLNA encodes an F-actin-binding cytoplasmic phosphoprotein and is involved in early brain neurogenesis and neuronal migration. A rare, recessive form of bilateral PNH with microcephaly and severe delay is associated with mutations of the ADP-ribosylation factor guanine nucleotide-exchange factor-2 (ARFGEF2) gene, required for vesicle and membrane trafficking from the trans-Golgi. However, PH is a heterogeneous disorder. We studied clinical and brain MRI of 182 patients with PH and, based on its anatomic distribution and associated birth defects, identified 15 subtypes. Classical bilateral PNH represented the largest group (98 patients: 54%). The 14 additional phenotypes (84 patients: 46%) included PNH with Ehlers-Danlos syndrome (EDS), temporo-occipital PNH with hippocampal malformation and cerebellar hypoplasia, PNH with fronto-perisylvian or temporo-occipital polymicrogyria, posterior PNH with hydrocephalus, PNH with microcephaly, PNH with frontonasal dysplasia, PNH with limb abnormalities, PNH with fragile-X syndrome, PNH with ambiguous genitalia, micronodular PH, unilateral PNH, laminar ribbon-like and linear PH. We performed mutation analysis of FLNA in 120 patients, of whom 72 (60%) had classical bilateral PNH and 48 (40%) other PH phenotypes, and identified 25 mutations in 40 individuals. Sixteen mutations had not been reported previously. Mutations were found in 35 patients with classical bilateral PNH, in three with PNH with EDS and in two with unilateral PNH. Twenty one mutations were nonsense and frame-shift and four missense. The high prevalence of mutations causing protein truncations confirms that loss of function is the major cause of the disorder. FLNA mutations were found in 100% of familial cases with X-linked PNH (10 families: 8 with classical bilateral PNH, 1 with EDS and 1 with unilateral PH) and in 26% of sporadic patients with classical bilateral PNH. Overall, mutations occurred in 49% of individuals with classical bilateral PNH irrespective of their being familial or sporadic. However, the chances of finding a mutation were exceedingly gender biased with 93% of mutations occurring in females and 7% in males. The probability of finding FLNA mutations in other phenotypes was 4% but was limited to the minor variants of PNH with EDS and unilateral PNH. Statistical analysis considering all 42 mutations described so far identifies a hotspot region for PNH in the actin-binding domain (P < 0.05).

Abnormalities, Multiple↗
PubMed2006

Intrauterine fetal demise following laser treatment in twin-to-twin transfusion syndrome.

OBJECTIVE: To evaluate the incidence, risk factors and consequences of intrauterine fetal demise (IUFD) of at least one twin in twin-to-twin transfusion syndrome (TTTS) treated by laser. DESIGN: Retrospective analysis. SETTING: Experience of a single centre between 1999 and 2004. POPULATION: A subgroup of 45 cases with fetal demise of one or both twins from a series of 120 cases of TTTS treated by laser. METHODS: All cases were entered prospectively into a dedicated database and the results were analysed retrospectively. MAIN OUTCOME MEASURES: Fetal demise prognostic factors, survival, fetal anaemia, brain lesions, neonatal death and intact survival. RESULTS: IUFD of one twin occurred in 40 of 120 cases (19 donors and 21 recipients). IUFD of both twins occurred in another five cases. From these 40 cases, miscarriage occurred in two and pregnancy termination was requested in another two cases because of antenatal brain lesions. Two neonates died and two presented severe morbidity, survivors were therefore neurologically normal at 6-44 months of life in 89% (32/36) of the cases. Univariate analysis showed that preoperative abnormal umbilical artery Doppler in the donor before laser treatment and in the recipient following laser treatment was associated with their demise. Incomplete coagulation was suspected in cases where anaemia or cerebral lesions developed following the death of the first twin (10). CONCLUSIONS: IUFD of one or both twins occurred in 45 of 120 (38%) cases of severe TTTS treated by laser. In these, separation of the placental circulations was incomplete in at least 22% (10/45) of the cases. Umbilical artery Doppler abnormalities before laser were found to be risk factors for the donors' demise following the procedure.

Anemia, Neonatal↗
PubMed2006

Evaluation of modified crystal violet chromoendoscopy procedure using new mucosal pit pattern classification for detection of Barrett's dysplastic lesions.

BACKGROUND: Pit pattern diagnosis is important for endoscopic detection of dysplastic Barrett's lesions, though using magnification endoscopy can be difficult and laborious. We investigated the usefulness of a modified crystal violet chromoendoscopy procedure and utilised a new pit pattern classification for diagnosis of dysplastic Barrett's lesions. METHODS: A total of 1,030 patients suspected of having a columnar lined oesophagus were examined, of whom 816 demonstrated a crystal violet-stained columnar lined oesophagus. The early group of patients underwent 0.05% crystal violet chromoendoscopy, while the later group was examined using 0.03% crystal violet with 3.0% acetate. A targeted biopsy of the columnar lined oesophagus was performed using crystal violet staining after making a diagnosis of closed or open type pit pattern with a newly proposed system of classification. The relationship between type of pit pattern and histologically identified dysplastic Barrett's lesions was evaluated. RESULTS: Dysplastic Barrett's lesions were identified in biopsy samples with an open type pit pattern with a sensitivity of 96.0%. Further, Barrett's mucosa with the intestinal predominant mucin phenotype was closely associated with the open type pit pattern (sensitivity 81.9%, specificity 95.6%). CONCLUSIONS: The new pit pattern classification for diagnosis of Barrett's mucosa was found to be useful for identification of cases with dysplastic lesions and possible malignant potential using a crystal violet chromoendoscopic procedure.

Acetates↗
PubMed2006

Randomized clinical trial of hepatectomy using intermittent pedicle occlusion with ischaemic intervals of 15 versus 30 minutes.

BACKGROUND: The optimal ischaemic interval during hepatectomy with intermittent pedicle occlusion (IPO) remains to be established. The aim of the present randomized clinical trial was to compare the short-term outcome of hepatectomy using IPO with an ischaemic interval of 15 versus 30 min. METHODS: Between October 2002 and September 2004, 108 consecutive patients scheduled to undergo hepatectomy without bilioenterostomy were enrolled. During liver transection, IPO was performed with an ischaemic interval of either 15 min with 5 min of reperfusion (standard group, SG) or 30 min with 5 min of reperfusion (prolonged group, PG). After randomization and subsequent exclusion of certain patients, 44 patients in the SG and 48 in the PG were analysed. RESULTS: The mean(s.d.) bilirubin ratio (serum total bilirubin level on day 2 after operation divided by the preoperative level) was 1.6(0.8) in the SG and 1.7(0.8) in the PG (P = 0.874). The transection area per unit transection time was significantly greater in the latter group (median (range) 1.0 (0.4-2.1) versus 0.8 (0.0-1.5) cm(2)/min; P = 0.046). CONCLUSION: There was no difference in the bilirubin ratio when IPO was carried out for 30 or 15 min. By extension of IPO to 30 min, a greater resection area per unit time was possible with preservation of remnant liver function.

Adult↗
PubMed2006

Determination of bovine serum low-density lipoprotein cholesterol using the N-geneous method.

The N-geneous method is a recently developed method for determination of low-density lipoprotein cholesterol (LDL-C) in human serum. In the present study, we attempted to adapt this method to bovine serum. The values of LDL-C obtained using the N-geneous method were highly correlated with those from the method using ultracentrifugation and heparin sepharose affinity chromatography (r = 0.934, p < 0.001). The reproducibility of this method was acceptable (intra-assay CV 4.2%, inter-assay CV 7.6%) for clinical use. Using the N-geneous method, serum LDL-C was evaluated in cows around parturition, and in cows with fatty liver induced by fasting. The concentration of LDL-C decreased significantly in cows close to parturition. A reduced concentration of LDL-C was also observed in cows with fatty liver. In both cases, the changes of LDL-C were similar to those of apolipoprotein B (apoB)-100, and the values of LDL-C were highly correlated (r = 0.876, p < 0.001) with those of apoB-100. These results suggest that the concentration of LDL-C reflects the level of apoB-100. The N-geneous method is simple and rapid, and might to be a useful tool to elucidate the clinical significance of LDL-C in bovine serum.

Animals↗
PubMed2006

A high incidence of intussusception in Japan as studied in a sentinel hospital over a 25-year period (1978-2002).

The development of second-generation rotavirus vaccines requires knowledge of baseline incidence rates for intussusception in infants prior to vaccine introduction. To obtain such estimates we reviewed clinical records in a hospital that served as the major provider of paediatric beds in a local community in the northern part of Japan. During the 25-year period (1978-2002), there were 91 hospitalizations due to radiologically confirmed intussusception in children <5 years of age, of which 45% were <1 year of age. Assuming that all children with intussusception in the area had been admitted to this hospital, there were an average of 185 and 78 hospitalizations per 100000 person-years for children <1 year old and 5 years old respectively. There was period-to-period variability with no long-term secular trend in the incidence of intussusception. The incidence rate in Japan was among the highest thus far reported, providing further evidence of geographic variability.

Child, Preschool↗
PubMed2006

Physical association of the patient-specific GATA1 mutants with RUNX1 in acute megakaryoblastic leukemia accompanying Down syndrome.

Mutations of the GATA1 gene on chromosome X have been found in almost all cases of transient myeloproliferative disorder and acute megakaryoblastic leukemia (AMKL) accompanying Down syndrome (DS). Although most GATA1 mutations lead to the expression of GATA1s lacking the N-terminal activation domain, we recently found two novel GATA1 proteins with defects in another N-terminal region. It has been suggested that loss of the N-terminal portion of GATA1 might interfere with physiological interactions with the critical megakaryocytic transcription factor RUNX1, and this would imply that GATA1s is not able to interact properly with RUNX1. However, the interaction domain of GATA1 remains controversial. In this study, we show that GATA1 binds to RUNX1 through its zinc-finger domains, and that the C-finger is indispensable for synergy with RUNX1. All of the patient-specific GATA1 mutants interacted efficiently with RUNX1 and retained their ability to act synergistically with RUNX1 on the megakaryocytic GP1balpha promoter, whereas the levels of transcriptional activities were diverse among the mutants. Thus, our data indicate that physical interaction and synergy between GATA1 and RUNX1 are retained in DS-AMKL, although it is still possible that increased RUNX1 activity plays a role in the development of leukemia in DS.

Animals↗
PubMed2006

Fat-tailed gene flow in the dioecious canopy tree species Fraxinus mandshurica var. japonica revealed by microsatellites.

Pollen flow, seed dispersal and individual reproductive success can be simultaneously estimated from the genotypes of adults and offspring using stochastic models. Using four polymorphic microsatellite loci, gene flow of the wind-pollinated and wind-seed-dispersed dioecious tree species, Fraxinus mandshurica var. japonica, was quantified in a riparian forest, in northern Japan. In a 10.5-ha plot, 74 female adults, 76 male adults and 292 current-year seedlings were mapped and genotyped, together with 200 seeds. To estimate dispersal kernels of pollen and seeds, we applied normal, exponential power, Weibull, bivariate t-distribution kernels, and two-component models consisting of two normal distribution functions, one with a small and one with a large variance. A two-component pollen flow model with a small contribution (26.1%) from short-distance dispersal (sigma = 7.2 m), and the rest from long-distance flow (sigma = 209.9 m), was chosen for the best-fitting model. The average distance that integrated pollen flows inside and outside the study plot was estimated to be 196.8 m. Tree size and flowering intensity affected reproduction, and there appeared to be critical values that distinguished reproductively successful and unsuccessful adults. In contrast, the gene flow model that estimated both pollen and seed dispersal from established seedlings resulted in extensive seed dispersal, and the expected spatial genetic structures did not satisfactorily fit with the observations, even for the selected model. Our results advanced small-scale individual-based parentage analysis for quantifying fat-tailed gene flow in wind-mediated species, but also clarified its limitations and suggested future possibilities for gene flow studies.

Alleles↗
PubMed2006

Restraint stress enhances alveolar bone loss in an experimental rat model.

BACKGROUND AND OBJECTIVE: The purpose of the present study was to examine the effects of restraint stress on periodontal breakdown resulting from Porphyromonas gingivalis-challenged periodontitis in rats. MATERIAL AND METHODS: To examine the influence of restraint stress on periodontal breakdown, rats were orally challenged with the periodontal pathogen P. gingivalis. Twenty male, specific pathogen-free (SPF) 3-wk-old, Sprague-Dawley rats were divided into four groups: group A (controls), group B (exposed to restraint stress for 12 h/d for 22 d), group C (orally challenged with P. gingivalis), and group D (exposed to restraint stress for 12 h/d for 22 d and orally challenged with P. gingivalis). After 22 d, all animals were killed. The distance from the alveolar bone crest to the cemento-enamel junction was determined, concentrations of adrenocorticotropic hormone were measured as stress markers, and atrophy of the thymus and spleen were assessed. In addition, the furcation area of the maxillary molars was examined histologically, while gingival cytokine gene expression was assessed by mRNA using reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: In the restrained group, all stress markers were elevated, and the thymus and spleen were atrophied. Combined restraint stress and oral challenge with P. gingivalis resulted in significantly higher bone loss, and osteoclasts were observed. RT-PCR analysis revealed low cytokine gene expression in the restrained groups. CONCLUSION: These results suggest that the presence of restraint stress significantly enhances the progression of P. gingivalis-challenged periodontitis in rats.

Alveolar Bone Loss↗