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T Nishimura

Publications and source records attributed to T Nishimura.

At least 37 records · Page 2Linked to original sources
PubMed2004

Gap junctions are required for trophoblast proliferation in early human placental development.

Little is known about the role of gap junctional intercellular communication (GJIC) in human trophoblast differentiation, particularly during the formation of extravillous trophoblast (EVT) cell columns and their subsequent differentiation into invasive cells. We have identified transcripts for five connexin gap junction proteins in the early human placenta (Cx32, Cx37, Cx40, Cx43 and Cx45). Of these, Cx40 and Cx45 proteins immunolocalize to EVT in anchoring cell columns. Cx40 expression is prominent in the anchoring column throughout the first trimester of pregnancy (6-14 weeks gestation). We used first trimester placental villous explant cultures to determine the functional significance of the inhibition of GJIC in EVT cell proliferation and differentiation using two known GJIC inhibitors, carbenoxolone (CBX) and heptanol. The morphology of EVT outgrowths changed dramatically upon GJIC-blockade, from compact and organized outgrowths into a scattered group of rounded individual trophoblast cells, reminiscent of an early invasive phenotype. Furthermore, the inhibition of GJIC in placental explants by CBX or heptanol induced a switch away from the proliferative and towards an invasive EVT phenotype, as evident from (a) the loss of the proliferation marker Ki67 and (b) an increase in the invasive marker alpha1 integrin. We also utilized antisense oligonucleotides to inhibit Cx40 protein expression in placental explants. Cx40 antisense treatment also resulted in the abolishment of outgrowth EVT cell proliferation (as determined by Ki67 immunostaining). Together, these results suggest that gap junctions composed particularly of Cx40 channels are required for the proliferation of EVT cells in anchoring cell columns, and that a loss of GJIC contributes to differentiation to the invasive EVT phenotype.

Carbenoxolone↗
PubMed2004

A key factor of translation reinitiation, ribosomal protein L24, is involved in gynoecium development in Arabidopsis.

In polycistronic genes, uORFs (upstream open reading frames) within the 5'-transcript leader sequence of major ORFs may regulate the translation of these major ORFs. In this case, ribosome reinitiates translation at a start codon of downstream ORF after translation termination of uORF. The plant RPL24 (ribosomal protein L24) is a key factor for translation reinitiation of downstream ORFs on the polycistronic cauliflower mosaic virus 35S RNA transcription unit. In the RPL24-deficient mutant of Arabidopsis, short valve (stv), the basal region of the ovary is shortened, whereas the gynophore appears elongated. This phenotype is never seen in known mutants of other ribosomal protein genes, suggesting that RPL24 has a specific role in gynoecium development. Similar phenotypes were observed in the ett (ettin) and mp (monopteros) mutants. Both ETT and MP genes possess uORFs. We examined the hypothesis that these uORFs regulate their downstream major ORFs by a transient expression assay in Arabidopsis mesophyll protoplasts. Our results supported the idea, suggesting that the structural defects of the gynoecium in stv mutants were caused by decreased efficiency of translation reinitiation of ETT and/or MP.

Arabidopsis↗
PubMed2004

CT-based evaluation of axillary sentinel lymph node status in breast cancer: value of added contrast-enhanced study.

PURPOSE: To evaluate the diagnostic reliability of CT-based sentinel lymph node (SLN) size criteria for selecting the candidates for direct axillary dissection without SLN biopsy and to determine the value of added contrast-enhanced study. MATERIAL AND METHODS: Breast cancer patients (n = 107) underwent triple phasic (1-min, 3-min, 8-min) contrast-enhanced 5 mm-computed tomography (CT) of the breasts and axillae. In the CT image, the most inferior lymph node in the axilla was designated the SLN. Axillary status was judged based on SLN size criteria. CT density, enhancement rate, and peak enhancement time of each SLN were correlated with histopathological results. RESULTS: SLN size criteria demonstrated a sensitivity of 76% and a positive predictive value of 95% in predicting SLN metastasis. The density values at each scanning time-point were significantly different for metastatic and non-metastatic SLN. However, their enhancement rates differed significantly only at 1 min. Their peak enhancement occurred primarily at 1 min. The use of contrast-enhancement criteria improved the predictive sensitivity, but failed to decrease the false-positive rate of the SLN size criteria. CONCLUSION: The enhancement rate at 1 min proved to be the most useful parameter in contrast-enhanced CT studies; however, it failed in improving the accuracy of the SLN size criteria.

Adult↗
PubMed2004

Expression of pigment epithelium derived factor and vascular endothelial growth factor in choroidal neovascular membranes and polypoidal choroidal vasculopathy.

AIMS: To determine whether pigment epithelium derived factor (PEDF), a protein that inhibits angiogenesis, is expressed in human choroidal neovascular membranes (CNVMs) and in tissues from an eye with polypoidal choroidal vasculopathy (PCV). In addition, to compare the expression of PEDF with that of vascular endothelial growth factor (VEGF), a known stimulator of angiogenesis, in these tissues. METHODS: CNVMs, associated with age related macular degeneration (AMD), angioid streaks, and PCV, were obtained during surgery. The expression of PEDF and VEGF in the excised subretinal fibrovascular membranes was determined by immunohistochemistry. RESULTS: PEDF and VEGF were strongly expressed in the vascular endothelial cells and retinal pigment epithelial (RPE) cells in the CNVMs where numerous new vessels were prominent (clinically active CNVMs). On the other hand, immunoreactivity for PEDF and VEGF was weak in the new vessels where fibrosis was prominent (clinically quiescent CNVMs). However, the RPE cells were still positive for PEDF and VEGF. The specimens from the eye with PCV also showed strong expression of PEDF and VEGF in the vascular endothelial cells and the RPE cells. CONCLUSION: Because PEDF is an inhibitor of ocular angiogenesis and an inhibitor of ocular cell proliferation, our results suggest that PEDF along with VEGF may modulate the formation of subfoveal fibrovascular membranes.

Aged↗
PubMed2004

Case report: adenosquamous carcinoma of the liver successfully treated with repeated transcatheter arterial infusion chemotherapy (TACE) with degradable starch microspheres.

This report describes a 58-year-old female with adenosquamous carcinoma (ASC) of the liver presenting with right lower abdominal pain. In most ASC of the liver, surgery is the first choice of treatment. However, surgery often seems to be ineffective because of the aggressive behaviour of this disease. At surgical laparotomy in the present case, there was a large tumour occupying the entire right lobe of the liver and invading the diaphragm. Thus, partial hepatectomy was performed. For the residual tumour, we performed repeated transcatheter arterial infusion chemotherapy with degradable starch microspheres (DSM). After four sessions of transcatheter arterial infusion chemotherapy, tumour size decreased remarkably and tumour markers had also decreased. Despite the poor prognosis, the patient remains alive and well 12 months after laparotomy. It is suggested that minimally invasive transcatheter infusion chemotherapy with DSM can be an effective treatment preserving a high quality of life.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2004

Intrahepatic portosystemic venous shunt passing through the left inferior phrenic vein and draining into the left renal vein.

We report a case of an intrahepatic portosystemic venous shunt (IPSVS) passing through the left inferior phrenic vein and draining into the left renal vein and then to the inferior vena cava. We incidentally detected the IPSVS while performing a transcatheter arterial embolisation for the treatment of hepatocellular carcinoma. IPSVS with the left inferior phrenic vein as the draining vein is very rare. The complete pathway of this IPSVS could be clearly demonstrated by multidetector row CT during arterial portography.

Aged↗
PubMed2003

A continuing high incidence of subacute sclerosing panencephalitis (SSPE) in the Eastern Highlands of Papua New Guinea.

The aims of this descriptive study were to confirm the high incidence of subacute sclerosing panencephalitis (SSPE) previously reported from Papua New Guinea (PNG) and to relate SSPE to previous measles vaccination and measles illness. From February 1997 to April 1999 we diagnosed a total of 55 patients with SSPE at Goroka Base General Hospital in Eastern Highlands Province (EHP) of PNG. The diagnosis was based on high cerebrospinal fluid and serum measles virus antibody titres with progressive neurological disorder and myoclonic jerks. Of these 55 patients 42 were from EHP, including 32 whose onset was in the 2-year period 1997-1998. The annual incidence of SSPE in EHP in these 2 years was 98 per million population under 20 years of age, the highest ever reported. This incidence was more than ten times higher than the highest incidence in the prevaccine era reported from elsewhere. The mean age of onset of SSPE was 7.7 years (range 2.8-14.8 years) and the interval between measles and the onset of SSPE, where known, had a mean of 5.9 years and a range of 2.5-11.1 years. Among the SSPE patients 19 had a documented history of measles vaccination. Eight of these 19 also had documentation of previous measles illness; of these, seven were vaccinated after the development of measles and one was vaccinated 20 days before measles illness. Two non-SSPE children received vaccination twice which was documented and subsequently developed measles which was also substantiated by documentation. Two patients with SSPE yielded amplified nucleotide sequences of measles virus that were different from any of the vaccine strains. We found no evidence to implicate measles vaccination in the development of SSPE.

Acute Disease↗
PubMed2003

Impaired cardiac response to exercise in post-menopausal women: relationship with peripheral vascular function.

Endothelial dysfunction has been demonstrated in post-menopausal women. To assess the relationship between peripheral vascular reserve and cardiac function during exercise in post-menopausal women, 91 subjects, who had no ischaemic findings on myocardial SPECT, were assigned to four groups: pre-menopausal women (n=13), post-menopausal women (n=33), younger men aged < or =50 years (n=10), and older men aged >50 years (n=35). First-pass radionuclide angiography was performed before and during bicycle exercise to calculate ejection fraction (EF) and peripheral vascular resistance (VR). There were no differences in haemodynamic variables among the groups at baseline. The per cent increase in EF=(exercise EF - resting EF)x100/resting EF, and the per cent decrease in VR=(resting VR - exercise VR)x100/resting VR were depressed in the post-menopausal women (0.4+/-2% and 35+/-3%, respectively) compared to the pre-menopausal women (10+/-3% and 47+/-3%, respectively; P<0.05 each). Although the age dependent impairment is thought to cause this depression, neither the per cent increase in EF nor the per cent decrease in VR in the older men was significantly different from that in the younger men. Post-menopausal women exhibited depressed cardiac function during exercise, which may be related to the impairment of peripheral vascular function after menopause.

Adult↗
PubMed2003

Gamma camera coincidence imaging with [18F]fluorodeoxyglucose in the pretreatment evaluation of patients with oesophageal cancer.

This study investigated the role of [18F]fluorodeoxyglucose (FDG) dual-head gamma camera coincidence imaging (GCI) in the pretreatment evaluation of patients with oesophageal cancer. Twenty-two patients (20 men; mean age, 64 years) with untreated, biopsy proven squamous cell carcinoma of the oesophagus underwent positron emission tomography (PET) and GCI 1 and 3 h after a single injection of FDG, respectively. Computed tomography (CT) was performed within 2 weeks of the FDG imaging. The sensitivity of lesion detection was compared between GCI and PET. Regional (N) and distant (M) metastases detected by GCI were evaluated with reference to PET and CT. The staging obtained by each modality was also compared with pathological staging in nine patients who underwent surgery. FDG PET detected 22 primary tumours, 34 metastatic lymph nodes and four organ metastases. Of them, GCI detected all primary tumours, 24 (71%) metastatic lymph nodes, and none of the organ metastases. Lymph nodes missed by GCI were smaller in size and the majority of them were located in the thoracic region. GCI provided N and M staging identical to CT and PET in eight patients and improved staging over CT in four patients. On the other hand, GCI missed metastases detected by both PET and CT in five patients. The addition of GCI to CT could improve detection of patients with metastasis to 82% (18/22) compared with 64% (14/22) detected by CT alone. In patients with pathological staging (n = 9), GCI could influence management changes in two patients (22%). In conclusion, FDG GCI has a role that is complementary to CT in the initial staging of patients with oesophageal cancer, and due to the additional detection of nodal metastasis, GCI can provide staging information, which may influence changes in management.

Aged↗
PubMed2003

Retrievable vena cava filter placement during treatment for deep venous thrombosis.

The purpose of our study is to evaluate the safety of insertion and removal of the retrievable vena cava filter and the efficacy of this filter in preventing pulmonary embolism during treatment of stenosis or obstruction of the lower extremity due to deep venous thrombosis. We retrospectively evaluated placement of 10 filters in 6 patients with lower extremity deep venous thrombosis who had undergone various treatments, including those utilizing techniques of interventional radiology. Worsening of or the new formation of pulmonary embolism was prevented in all patients. All attempts at both implantation and retrieval of the filter were safely accomplished. No complication related to filter placement occurred. Filters were left in the vena cava for permanent use when deep venous thrombosis was refractory to treatment. These results demonstrate that both placement and removal of the retrievable vena cava filter can be accomplished safely and that this type of filter is useful to prevent pulmonary embolism during treatment of deep venous thrombosis of the lower extremity. Further, the use of a retrievable vena cava filter might be preferred over that of a temporary vena cava filter, especially if further implantation of a filter becomes necessary since replacement with a permanent filter would not be required when using a retrievable vena cava filter.

Adult↗
PubMed2003

Visualization of prostate cancer using dynamic contrast-enhanced MRI: comparison with transrectal power Doppler ultrasound.

This study was designed to assess the efficacy of dynamic contrast-enhanced MRI (DCE-MRI), in comparison with power Doppler ultrasound (PDUS), for visualizing prostate cancer. 111 men suspected of having prostate cancer underwent imaging before undergoing octant biopsy. Subsequently, 31 cancer-positive patients were enrolled in this study. DCE-MRI was obtained using a three-dimensional fast-field echo sequence, which assured wide coverage of the prostate gland. The transrectal PDUS were scored according to the degree of power Doppler flow signals. The time intensity curve types for the DCE-MRI and the PDUS scores were compared with the histopathologic results for each region. The time intensity curves were correlated significantly with PDUS scores (p<0.001). Using PDUS, the overall sensitivity, specificity and accuracy of cancer visualization in peripheral zones were 69%, 61% and 66%, respectively. Using DCE-MRI, the corresponding values were 87%, 74% and 82%. In the inner gland, using PDUS, the overall sensitivity, specificity and accuracy were 68%, 94% and 83%, respectively. Using DCE-MRI, the corresponding values were similar (68%, 86% and 78%). DCE-MRI was significantly more sensitive than transrectal PDUS in peripheral zones (p<0.05). In conclusion, both transrectal PDUS and DCE-MRI can be used to demonstrate hypervascularity in many prostate cancers. DCE-MRI was significantly more sensitive than PDUS for visualizing of prostate cancers without loss of specificity in the peripheral zone.

Aged↗
PubMed2003

Chromosomal instability and human hepatocarcinogenesis.

Recently, many studies have identified losses and gains of several chromosomal loci in human hepatocellular carcinoma (HCC) with fine microsatellite analysis and comparative genomic hybridization. Although distribution of aberrant chromosomal arms differs among HCCs, loss of 1p, 4q, 6q, 8p, 9p, 10q, 13q, 16q and 17p, and gain of 1q, 6p, 8q, 17q and 20q have been recurrently reported, and loss of 4q and 16q seems to occur preferentially in hepatitis B virus-related HCCs. Accumulation of these aberrant chromosomal regions is associated with tumor progression, and some chromosomal aberrations, such as loss of 1p, are frequently identified in well-differentiated HCCs and also detected even in dysplastic nodule and cirrhotic nodule. This evidence suggests that chromosomal instability (CIN) emerges at an early stage during hepatocarcinogenesis and is successively inherent to tumor cells, resulting in acquisition of malignant phenotype. The molecular basis of CIN is beginning to be explored; however, several mechanisms may be involved for CIN of HCC.

Allelic Imbalance↗