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Junji Ueda

Publications and source records attributed to Junji Ueda.

14 recordsLinked to original sources
PubMed2006

Analysis of specific factors generating 2-cell block in AKR mouse embryos.

The phenomenon of the developmental arrest at the 2-cell stage of 1-cell embryos from some mouse strains during in vitro culture is known as the 2-cell block. We investigated the specific factors involved in the 2-cell block of AKR embryos by means of a modified culture system, the production of reconstructed embryos by pronuclear exchange and a cross experiment. In a culture medium with phosphate, 94.6% of 1-cell embryos from the C57BL mouse strain developed to the blastocyst stage, but 95.7% of embryos from the AKR mouse strain showed 2-cell block. Phosphate-free culture medium rescued the 2-cell block of AKR embryos and accelerated the first cell cycle of the embryos. Co-culture with BRL cells and a BRL-conditioned medium fractionated below 30 kDa also rescued the 2-cell block of AKR embryos. Examinations of in vitro development of reconstructed embryos and of embryos from F1 females between AKR and C57BL strains clearly demonstrated that the AKR cytoplast caused the 2-cell block. In the backcrossed female progeny between (AKR x C57BL) F1 males and AKR females, about three-quarters of the embryos were of the 2-cell blocking phenotype and about one-quarter were of the non-blocking phenotype. These results suggest that two genes are responsible for the 2-cell block of AKR embryos.

Animals↗
PubMed2006

Successful emergency enterectomy for bleeding ileal varices in a patient with liver cirrhosis.

We report a rare case of bleeding ileal varices successfully treated with emergency enterectomy. A 72-year old woman with hepatic cirrhosis due to hepatitis C was admitted to our hospital because of anemia and hematochezia. An endoscopic examination showed no evidence of bleeding in the upper and lower gastrointestinal tracts. Angiographic studies of portal hemodynamics revealed extravasation from the ileal varices and total occlusion of the portal vein due to portal thrombus. This made it difficult to remove the ileal varices using interventional radiology. Therefore, the patient underwent emergency enterectomy for the ileal varices. No further gastrointestinal bleeding occurred during the 1-year follow-up.

Aged↗
PubMed2006

Molecular cloning, testicular postnatal expression, and oocyte-activating potential of porcine phospholipase Czeta.

The molecular mechanism by which sperm triggers Ca2+ oscillation, oocyte activation, and early embryonic development has not been clarified. Recently, oocyte activation has been shown to be induced by sperm-specific phospholipase Czeta (PLCzeta). The ability of PLCzeta to induce oocyte activation is highly conserved across vertebrates. In the present study, porcine PLCzeta cDNA was identified and the nucleotide sequence was determined. The expression pattern of porcine PLCzeta mRNA during the period of postnatal testicular development was shown to be similar to that of mouse PLCzeta. PLCzeta mRNA expression in the pig and mouse was detected only in the testes when the elongated spermatids had differentiated, and was detected from day 96 after birth in the pig. Histological examination of porcine testis during the period of postnatal development revealed the presence of spermatozoa from day 110 after birth. These findings suggest that the synthesis of PLCzeta mRNA starts when spermiogenesis is initiated. Microinjection of porcine PLCzeta complementary RNA into porcine oocytes demonstrated that porcine PLCzeta has the ability to trigger repetitive Ca2+ transients in porcine oocytes similar to that observed during fertilization. It was also found that porcine PLCzeta cRNA has the potential to induce oocyte activation and initiate embryonic development up to the blastocyst stage.

Amino Acid Sequence↗
PubMed2005

Resection of liver metastases from an alpha-fetoprotein-producing gastric cancer.

We describe successful resection of rapidly enlarging liver metastases from an alpha-fetoprotein-producing gastric cancer, as these usually carry a dismal prognosis. A 68-year-old woman underwent distal gastrectomy for an alpha-fetoprotein-producing gastric cancer without liver metastasis. The tumor was a moderately differentiated tubular adenocarcinoma with invasion of the muscularis propria. Venous and lymphatic invasion were noted, as was metastasis to lymph nodes along the greater curvature. Serum alpha-fetoprotein was 331 ng/mL before gastrectomy, decreasing to 18.6 ng/mL by postoperative day 28. At 2 months after operation, computed tomography detected no metastasis, but at 4 months alpha-fetoprotein increased to 2,190 ng/mL, and at 5 months liver tumors were detected by ultrasonography and computed tomography. Serum alpha-fetoprotein increased to 5,673 ng/mL, and serum PIVKA2 concentration was 18 mAU/ml just before operation. Extended left hepatectomy was performed. The resected specimen of segment 4 contained two well-defined tumors, measuring 5 x 4 cm and 2 x 2 cm, while that of segment 5 contained a similar-appearing tumor measuring 2 x 2 cm. The resected tumors had the same histologic appearance as the previously removed gastric cancer. The tumor cells were immunohistochemically reactive for alpha-fetoprotein. The postoperative course was uneventful, and the patient was discharged on postoperative day 15. Serum alpha-fetoprotein decreased to 20 ng/mL by postoperative day 15, and to 5 ng/mL by 2 months after operation. For 5 months since operation, no recurrence has become evident, and serum alpha-fetoprotein has remained within the normal range.

Adenocarcinoma↗
PubMed2005

[Meningioma].

Explore the source record for details and available documents.

Diagnosis, Differential↗
PubMed2004

Novel and quantitative DNA dot-blotting method for assessment of in vivo proliferation.

Immunohistochemical assessment of 5-bromo-2-deoxyuridine (BrdU) in tissue sections is a widely used method to evaluate cell proliferation in vivo. However, this method requires time-consuming preparation of paraffin sections and laborious counting of BrdU-labeled nuclei on multiple sections. Here, we report the development of a rapid and reliable method to quantitate BrdU incorporation in intestinal and liver tissues using a dot-blot method. In vivo models of colon or liver proliferation were used to analyze the usefulness and reliability of this new method. Mice were killed after BrdU injection, and genomic DNA was isolated from the tissues, denatured, and dot-blotted onto a nitrocellulose membrane. The incorporated BrdU was detected with a BrdU monoclonal antibody, and the signal intensity was densitometrically quantified. Results were compared with BrdU index determined by conventional immunohistochemistry on the same tissue samples. The patterns of colonic BrdU incorporation during fasting and refeeding, measured by the dot-blotting method and the immunohistochemical method, were similar. The BrdU incorporation in the regenerating liver after partial hepatectomy, evaluated by these two different methods, showed a strong correlation (R(2) = 0.91, P < 0.01). In addition, the inhibition of colon proliferation by the phosphoinositol 3-kinase inhibitor wortmannin was demonstrated by this dot-blotting method. In conclusion, the dot-blotting technique described in this report provides an accurate, more efficient, and possibly more reliable method for the assessment of in vivo proliferation compared with conventional immunohistochemical determination of BrdU-labeling index.

Androstadienes↗
PubMed2004

Cyclin expression in the atrophying and proliferating lobes of the liver after portal vein branch ligation and hepatectomy in rats.

BACKGROUND: Portal vein branch ligation causes atrophy of the portal vein ligated lobes (PVL) and proliferation of the nonligated lobes (PVNL) of the liver. However, the mechanisms underlying atrophy of the PVL and proliferation of PVNL after portal vein branch ligation have not been clarified except that interleukin-6 (IL-6), nuclear factor kappa B (NF-kappaB), signal transducer and activator of transcription 3 (STAT3), and immediate-early gene expression are similarly induced in both the PVL and the PVNL. Thus, it is still unclear what factors cause the subsequent atrophy and proliferation. MATERIALS AND METHODS: Male Wistar rats were randomly separated into a portal vein branch ligation group and partial hepatectomy group. In the portal vein branch ligation group, the branch of portal vein supplying the median and left lateral lobes of the liver was ligated. In the partial hepatectomy group, the correspondent lobes of the liver were excised. We examined cyclin expression in the PVL and PVNL after portal vein branch ligation in comparison to cyclin expression in the remaining liver (HEP) after partial hepatectomy. Cyclin D1, E, and A mRNA and protein expressions were analyzed by RT-PCR and Western blotting, respectively. RESULTS: The mRNA and protein expressions of cyclin D1 and A were not up-regulated in the PVL, whereas those in the PVNL and HEP were up-regulated. Cyclin D1 mRNA and protein expressions were significantly lower in the PVL than in the PVNL and HEP at 18 h. The levels of mRNA and protein expression of cyclin A were significantly lower in the PVL than in the PVNL and HEP at 36 h. Liver regeneration, assessed by the relative liver weight, thymidine incorporation into DNA, and proliferating cell nuclear antigen (PCNA) labeling index was delayed significantly in the PVNL compared to that in the HEP. Cyclin D1 mRNA and protein expressions were significantly lower in the PVNL than in the HEP at 12 and 18 h, respectively. CONCLUSIONS: Cell-cycle progression might be inhibited at G(1)-phase accompanied by impaired cyclin D1 expression in the PVL, which results in atrophy. The fact that liver proliferation of the PVNL is delayed in comparison to that of the HEP is likely due to delayed expression of cyclin D1.

Animals↗
PubMed2004

A functional truncated form of c-kit tyrosine kinase is produced specifically in the testis of the mouse but not the rat, pig, or human.

The complete nucleotide sequence of mouse-truncated mRNA of c-kit, tr-kit, has been determined using the CD1 strain. In this study, the nucleotide sequences of tr-kit from AKR/N, C57BL/6, and ICR strains of mice were determined and found to be identical, although many silent variations were found compared with the sequence in a database for CD1. Tr-kit protein consists of 12 amino acids encoded by the 16th intron and the following 190 amino acids of c-kit. In the sequences of tr-kit encoding 12 specific amino acids, no substitution was detected among the three strains and CD1. Furthermore, RT-PCR analysis clearly showed that tr-kit mRNA expression was present only in testis. No nucleotide mutation in two important regions of the presumptive promoter for tr-kit mRNA was detected within the 16th intron of the mouse strains examined. However, no functional form of tr-kit was found in the rat, pig, or human by sequence analysis and homology testing.

Amino Acid Sequence↗
PubMed2004

Effects of delipidation and oxygen concentration on in vitro development of porcine embryos.

The effects of delipidation and the oxygen (O(2)) concentration in the atmosphere during culture on in vitro development and H(2)O(2) content were investigated in porcine in vivo fertilized embryos and embryos after in vitro maturation and in vitro fertilization (IVM/IVF embryos). There was no significant difference in the developmental rates to the blastocyst stage between the intact and delipidated IVM/IVF embryos. However, the mean number of cells in blastocysts derived from delipidated IVM/IVF embryos (19.8 +/- 0.8 cells) was significantly smaller than that from intact embryos (24.2 +/- 1.2 cells). Although there were no significant differences in the developmental rates to the blastocyst stage of intact and delipidated IVM/IVF embryos between the cultures under 5% O(2) and 20% O(2), the developmental rate of intact IVM/IVF embryos cultured under 5% O(2) (27.1%) was significantly higher than that of the delipidated embryos cultured under 20% O(2) (19.3%). On the other hand, there was no difference in the developmental rate to the blastocyst stage between in vivo fertilized embryos cultured under 5% O(2) and 20% O(2). Hydrogen peroxide (H(2)O(2)), one of the reactive oxygen species (ROS), is thought to cause damage to embryos. The H(2)O(2) content per embryo derived from oocytes cultured under 5% O(2) (in vivo fertilized, 58.0 +/- 2.5 pixels; IVM/IVF, 79.6 +/- 3.2 pixels) was significantly lower than that (in vivo fertilized, 100.2 +/- 3.8 pixels; IVM/IVF, 103.9 +/- 3.2 pixels) under 20% O(2). Furthermore, the level of H(2)O(2) in delipidated IVM/IVF embryos (94.7 +/- 3.9 pixels) was significantly lower than that in intact embryos (103.9 +/- 3.2 pixels) cultured under 20% O(2). The present results indicate that the delipidation of porcine IVM/IVF embryos and reduction of the O(2) concentration decreased the H(2)O(2) level rather than the in vitro developmental rate to the blastocyst stage.

Animals↗
PubMed2002

Inhibited activities in CCAAT/enhancer-binding protein, activating protein-1 and cyclins after hepatectomy in rats with thioacetamide-induced liver cirrhosis.

Transcriptional activation of nuclear factor (NF)-kappaB, signal transducers and activators of transcription (STAT) 3, activating protein (AP)-1 and CCAAT/enhancer-binding protein (C/EBP) plays an important role in liver regeneration by modulating cell cycle regulators. The regeneration of cirrhotic liver after hepatectomy is inhibited despite intact expression of growth factors. To elucidate the mechanism involved, regeneration responses in growth factor receptors, transcription factors, and cell cycle regulators after two-thirds hepatectomy were compared between rats with thioacetamide-induced cirrhotic and normal liver. The expression of c-met and epidermal growth factor receptor analyzed by RT-PCR and immunohistochemistry did not differ between the two groups. The activities of C/EBP and AP-1 evaluated by electrophoretic mobility shift assay were significantly inhibited in the cirrhotic group compared with those in the control group, but not those of NF-kappaB and STAT3. The expression of cyclin-D1, -E, and -A assessed by Western blot analysis was significantly decreased in the cirrhotic group compared with the control group. The level in p21(Cip1) or p27(Kip1) did not differ between the two groups. The liver regeneration estimated by the rates of [(3)H]thymidine incorporation into DNA and staining of proliferating cell nuclear antigen was significantly lower in the cirrhotic rats than in the controls. In conclusion, downregulation of cyclin -D1, -E, and -A expression, which may be induced by impaired activities of C/EBP and AP-1, is responsible for the decreased regenerative capacity of cirrhotic liver after partial hepatectomy.

Animals↗
PubMed2002

Relation of biliary bile acid output to hepatic adenosine triphosphate level and biliary indocyanine green excretion in humans.

We have previously demonstrated that there are two subgroups of patients with different types of biliary bile acid output after relief of obstructive jaundice by percutaneous transhepatic biliary drainage (PTBD). The reason for two groups is not clear but is possibly the difference in hepatic reserve function. The aim of this study was to examine the relation of biliary bile acid output to the hepatic ATP level and biliary excretion rate of indocyanine green (ICG) in humans. Patients whose bile could be collected through a PTBD tube participated in this study. The mean serum total bilirubin concentration was 12.7 mg/dl at the time of PTBD, decreasing to 1.1 mg/dl before surgery. These patients underwent curative resection for cancer of the bile duct, duodenal papilla, or pancreatic head after the relief of hyperbilirubinemia. Bile was collected at 1-hour intervals for 5 hours after intravenous administration of ICG (0.5 mg/kg) within a few days before surgery, and a small liver tissue sample was obtained immediately after laparotomy without using ischemic procedures. The concentrations of total bile acid and ICG in bile, the bile flow rate, and the bile acid output and ICG excretion rate in bile over 5 hours were determined. ATP concentrations in liver tissue were determined by high performance liquid chromatography. Results of hepatic ATP levels were correlated with the bile acid output and ICG excretion rate into bile. Both the biliary bile acid output (micromoles per 5 hours) and ICG excretion rate (percent of injected dose of ICG) over 5 hours were significantly correlated with the hepatic ATP level (p = 0.0190 and p = 0.0084, respectively). Neither the bile flow rate nor the serum liver function tests were related to the hepatic ATP level. Significant correlation was found between the bile acid output and the ICG excretion rate (p = 0.0127). Biliary bile acid output reflects the hepatic ATP level. Determination of the biliary bile acid output and ICG excretion may provide useful parameters for evaluating the hepatic energy status, which is essential for organ viability.

Adenosine Triphosphate↗
PubMed2002

Lack of intestinal bile results in delayed liver regeneration of normal rat liver after hepatectomy accompanied by impaired cyclin E-associated kinase activity.

BACKGROUND: The importance of bile in liver regeneration after hepatectomy is unknown, although we have recently shown that preoperative internal biliary drainage is superior to external biliary drainage for liver regeneration in obstructive jaundiced rats. This study examined the hypothesis that the presence or absence of bile in the intestinal tract modulates cyclins and cyclin-dependent kinases after hepatectomy in rats. METHODS: In male Wistar rats, bile was drained externally (ED group) or into the duodenum (ID group) for 7 days before 70% hepatectomy. Relative liver weight, DNA synthesis rate, and proliferating cell nuclear antigen labeling index were determined at the time of hepatectomy (day 0) and on days 1, 3, and 7 after hepatectomy. Posthepatectomy expressions of cyclin D1 and E and of cyclin D1- and E-associated kinases were serially analyzed. Hepatic function tests were performed. RESULTS: No significant difference in liver function was found between the 2 groups at hepatectomy except for the lower albumin level in the ED group. The relative liver weight was lower in the ED group than in the ID group on day 3 after hepatectomy (ED, 2.58% +/- 0.06%; ID, 2.84% +/- 0.08%; P <.05). Both the DNA synthesis rate and proliferating cell nuclear antigen labeling index in the ED group (77 +/- 36 disintegrations per minute/microg DNA and 8.3% +/- 1.9%, respectively) were lower than those in the ID group (262 +/- 50 disintegrations per minute/microg DNA and 21.6% +/- 5.6%, respectively) on day 1 after hepatectomy (P <.05, respectively). Cyclin D1-associated kinase activity and cyclin D1 expression were not significantly different between the 2 groups. Cyclin E-associated kinase activity was lower in the ED group than in the ID group at 18 hours after hepatectomy (ED, 84% +/- 17%; ID, 146% +/- 28% of the value at 0 hour in the ID group; P <.05), although expressions of cyclin E and p27 binding to cyclin E were not significantly different between the 2 groups. CONCLUSIONS: These results suggest that the absence of bile in the intestine delays liver regeneration associated with cyclin E-associated kinase inactivation after hepatectomy.

Amylases↗
PubMedDate not supplied

Combination therapy of resection and intraoperative radiation for patients with carcinomas of extrahepatic bile duct and ampulla of Vater: prognostic advantage over resection alone?

BACKGROUND/AIMS: To investigate the therapeutic efficacy of intraoperative radiation for carcinomas of the bile duct and ampulla of Vater. METHODOLOGY: Postoperative morbidity, mortality and survival of patients undergoing surgical resection of ampullary cancer (n = 19) and bile duct cancer (n = 28) were retrospectively compared between two groups with and without intraoperative radiation. RESULTS: Background items (age, gender, preoperative laboratory data, operative time and bleeding volume, tumor stage) did not differ significantly between the two groups. The predominant postoperative complication was leakage of pancreatic juice, which occurred in similar rates in both groups. No significant differences were noted in the 3-year survival rates between the resection plus intraoperative radiation group and resection alone group (60.0% (n = 5) vs. 50.1% (n = 13) for ampullary cancer; 0% (n = 4) vs. 27.1% (n = 24) for bile duct cancer, respectively). The main causes of recurrence were distant metastasis for ampullary cancer and microscopic residue of carcinoma for bile duct cancer. CONCLUSIONS: The combination of intraoperative radiation and resection may add no significant benefit to patients with ampullary and bile duct cancer when compared with resection alone.

Aged↗