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Biomedical subjects

K Ueda

Publications and source records attributed to K Ueda.

At least 505 records · Page 28Linked to original sources
PubMed1996

Cellular factors controlling the activity of woodchuck hepatitis virus enhancer II.

Woodchuck hepatitis virus (WHV) efficiently induces hepatocellular carcinoma in chronically infected hosts. A key step in hepatocarcinogenesis by WHV is insertional activation of the cellular N-myc gene by integrated viral DNA. WHV enhancer II (En II) is the major cis-acting element involved in this activation. Here we characterize this viral enhancer element and define the cellular factors involved in its activity. WHV En II activity is strongly liver specific and maps to an 88-nucleotide DNA segment (nucleotides 1772 to 1859) located 5' to the pregenomic RNA start site. Genetic analyses and electrophoretic mobility shift assays indicate that the enhancer contains three subregions important to its activity. The core elements of the enhancer are recognition sites for the liver-enriched factors HNF1 and HNF4; together, these signals account for the bulk of En II activity as well as its strong liver specificity. Multimerization of either recognition site produced strong activity even in the absence of other En II sequences. 5' to these elements is a binding site for the ubiquitous Oct-1 transcription factor, which further augments enhancer activity ca. twofold.

3T3 Cells↗
PubMed1996

Rheumatoid factor in the serum of hepatitis C virus-infected patients: an increase in the titre during cold storage.

Storage of serum at 4 degrees C elevated the titre of rheumatoid factor (RF) as measured by nephelometry with IgG-coated latex in 12 of 38 specimens positive for hepatitis C virus. Increased RF following cold storage was not detected in HCV-negative sera. Most of the sera showing the cold-dependent elevation of RF had decreased complement hemolytic activity (CH50) after the cold storage. The RF titre elevated by cold storage decreased to the level of fresh serum by the addition of guinea pig serum as a complement supplement in a dose-dependent fashion. Thus, in the serum of some HCV-infected patients, the affinity of RF appears to be weak, and the binding between the RF and IgG coated on latex may be inhibited by the complement components of fresh serum.

Cold Temperature↗
PubMed1996

Synergistic response of cord blood myeloid progenitor cells to the combined administration of human granulocyte colony-stimulating factor and human stem cell factor in vitro.

We compared the in vitro response of myeloid progenitor cells [colony-forming units of culture (CFU-C)] that were prepared from human umbilical cord blood to the administration of the combination of granulocyte colony-stimulating factor (G-CSF) and stem cell factor (SCF) versus that of CFU-C obtained from normal human bone marrow. Progenitors were purified according to CD34 expression; the number and size of colonies were evaluated by culture in agar or methylcellulose, respectively. In the presence of G-CSF alone, the mean number of colonies was significantly greater in the bone marrow culture versus that of cord blood. SCF alone bad little effect on colony formation, but in the presence of optimal or suboptimal concentrations of G-CSF, SCF significantly increased colony formation from both cell sources. Its effect on cord blood significantly exceeded that on bone marrow. SCF used in combination with G-CSF significantly increased the size of the colonies with cord blood CFU-C; this effect was less marked with bone marrow CFU-C. The percentage of cells that expressed c-Kit, the SCF receptor, did not appear to differ between the two sources of CFU-C. Results indicate that cord blood CFU-C showed a greater response to SCF in combination with G-CSF than did bone marrow CFU-C.

Cells, Cultured↗
PubMed1996

Amino acids and peptides. XXVII. Solid phase synthesis of fibrinogen-related peptides with disulfide bond formed on solid support.

Fibrinogen-related peptides, monomeric cyclic peptides through a disulfide bond [cyclo(H-Cys-Arg-Gly-Asp-Phe-Cys-NH2), cyclo(H-Cys-Arg-Gly-Asp-Phe-Cys-Gly-NH2), cyclo(H-Cys-Arg-Gly-Asp-Cys-NH2) and cyclo(H-Cys-Arg-Gly-Asp-Cys-Gly-NH2)], were prepared by the solid phase method with disulfide bond formation on the solid support. The acetamidomethyl group was used for protection of the thiol group of Cys and synthetic peptide-resins were treated with iodine to give the disulfide bond. Monomeric cyclic peptides were obtained as main products. Purified S-acetamidomethylated peptides were also oxidized with iodine, but the desired materials could not be isolated by HPLC. The disulfide formation from S-acetamidomethylcysteine-containing peptide resin by iodine treatment on the solid support was more effective than that from S-acetamidomethylcysteine-containing peptide. The inhibitory effect of the cyclic peptides on platelet aggregation were much more potent than that of H-Arg-Gly-Asp-NH2.

Amino Acid Sequence↗
PubMed1996

A study of the luteolytic mechanism of the antiprogesterone RU486 during the late-luteal phase in pseudopregnant rats.

The purpose of this study was to examine the possible mechanism through which RU486 induces luteolysis during the late-luteal phase in pseudopregnant (PSP) rats. PSP rats received a subcutaneous injection of RU486 in sesame oil (5 mg/kg body weight) or sesame oil alone once a day between day 9 and day 11 of pseudopregnancy. Serial blood samples were collected on days 5, 9, 10, 11 and 12 and assayed for progesterone content. To examine the possible action of RU486 through a uterine and/or a pituitary (prolactin-dependent) mechanism, PSP rats and chronic hysterectomized PSP rats which had been hysterectomized before PSP induction received a subcutaneous injection of RU486 in sesame oil (5 mg/kg body weight), sesame oil alone, prolactin in 50% polyvinylpyrrolidone (15 IU/day), or RU486 and prolactin once a day between day 9 and day 11 of pseudopregnancy. Serial blood samples were collected on days 5, 9, 10 and 11 and assayed for progesterone content. Blood samples were also collected at 0400 h on day 12 and used for prolactin and progesterone determinations. To examine the direct effect of RU486 on corpus luteum and/or pituitary, hysterectomized rats underwent hypophysectomy and pituitary autotransplantation on dioestrus 1 and received a subcutaneous injection of RU486 in sesame oil or sesame oil alone for 3 days between day 21 and day 23 after surgery. Serial blood samples were collected on days 10, 21, 22, 23 and 24 and assayed for progesterone and prolactin contents. In ordinary PSP rats, serum progesterone levels were significantly (P < 0.01) lower in the RU486-treated group than in the control group (9 +/- 1 vs 53 +/- 7 ng/ml; mean +/- S.E.M.) on day 11. Serum prolactin levels at 0400 h on day 12 of pseudopregnancy were significantly (P < 0.05) lower in the RU486-treated group than in the control group (16 +/- 4 vs 154 +/- 44 ng/ml; mean +/- S.E.M.). The concomitant prolactin treatment reversed the luteolytic effects of RU486 on day 11 of pseudopregnancy. In hysterectomized PSP rats, RU486 also suppressed serum prolactin levels, and the concomitant prolactin treatment again reversed the luteolytic effects of RU486. In hysterectomized rats which were hypophysectomized and pituitary autotransplanted, RU486 treatment did not induce any significant changes in serum progesterone and prolactin levels. These results indicated that RU486 induced luteolysis during the late-luteal phase in PSP rats by suppressing prolactin secretion via a hypothalamic mechanism.

Animals↗
PubMed1996

Isolation, characterization, and chromosomal mapping of the human insulin promoter factor 1 (IPF-1) gene.

Insulin promoter factor 1 (IPF-1) is a homeodomain-containing protein that is thought to be a key regulator of pancreatic islet development and insulin gene transcription in beta-cells. This report describes the isolation and characterization of the human IPF-1 gene. The coding region, which showed 83% nucleotide identity with the mouse IPF-1 gene, was encoded by two exons that extended over a 5-kb region of human genome. The deduced human IPF-1 protein contained 283 amino acids, 1 amino acid less than the mouse IPF-1 protein. The homeodomain region of IPF-1 was encoded by the second exon, and it was highly conserved among species. The human IPF-1 gene was mapped to chromosome 13q12(12.1) by fluorescent in situ hybridization (FISH) analysis. A simple sequence repeat polymorphism (ipf1CA2) was identified in the genomic clone. Polymerase chain reaction (PCR) amplification of this repeat region revealed two alleles (heterozygosity = 0.32). This simple sequence repeat polymorphism, and thus the IPF-1 gene, was incorporated into the human linkage map by genotyping reference Human Polymorphism Study Center (CEPH) pedigrees. Multipoint analysis with the CEPH genotype database placed the gene with equal likelihood between two marker intervals: D13S292-cdx3GA1 and cdx3GA1-D13S289 on chromosome 13, consistent with the results of FISH analysis. Two-point linkage analysis inferred that the most likely location for ipf1CA2 was at theta = 0 from cdx3GA1 locus. The exon-intron boundaries of the IPF-1 gene were sequenced, and primers were synthesized to search the homeodomain region for potential variants in patients with NIDDM. By single-strand conformational polymorphism analysis, no variants were found within this region in 61 Japanese patients, which could contribute to the pathogenesis of NIDDM. The isolation of the human IPF-1 gene, along with characterization of its genomic structure and chromosomal mapping, will now permit the assessment of the role of this gene in the pathogenesis of NIDDM in various populations.

Amino Acid Sequence↗
PubMed1996

Aging effects in skeletal muscle recovery after reinnervation.

To investigate the influence of age on the process of muscle recovery after nerve repair, the nerves of the right extensor digitorum longus (EDL) and the right soleus muscles of 63 2-month-old and 61 15-month-old rats, respectively, were transsected and resutured. At four, eight, 16, and 24 weeks after nerve repair, functional recovery of the muscle was assessed by electromyographic (EMG) recordings and isometric muscle contraction. Muscle weight, morphological, and morphometric studies were also done. At four and eight weeks after nerve repair the younger age groups showed higher rates of recovery compared with the control side (left EDL and soleus) (recovery rate (%) = operated/control x 100) than the older age groups, and the recovery rates of soleus (slow twitch muscle) in both age groups were higher than EDL (fast twitch muscle). However, the differences between the two age groups decreased at 16 and 24 weeks after nerve repair in both muscles. We therefore conclude that earlier differences were the effects of nerve regeneration on the muscle between different ages and the reason for the reduced differences at later stages was that after reinnervation began, not only the nerve but also the muscle recovered successfully in older age groups, and slow motor units reinnervated faster than the fast units in both age groups. Our present study shows that the older age groups also have a good prognosis for recovery of muscle function after nerve repair.

Aging↗
PubMed1996

Surgical treatment of mandibular osteoradionecrosis: versatility of the scapular osteocutaneous flap.

Osteoradionecrosis of the mandible is a serious complication of radiotherapy for head and neck cancer and no single treatment has to date met with consistent success. A free scapular osteocutaneous flap was successfully transferred in nine patients with mandibular osteoradionecrosis who before this had not responded to conservative treatment. All but one of the patients had good bone union and there was no evidence of recurrence during a mean follow up period of four years and one month. This flap not only provides a well-vascularised segment of the bone but also multiple, large skin paddles, each with an abundant and reliable blood supply. In addition, well-vascularised fascia and overlying subcutaneous tissue can be used to fill dead spaces and cover the bony segment and fixation plates. This reduces postoperative infection and promotes primary wound healing. This flap has proved useful for reconstruction of mandibular osteoradionecrosis, particularly when there is a large soft tissue defect.

Adult↗
PubMed1996

A flap to monitor a temporoparietal fascial flap. Case report.

The temporoparietal fascial flap is useful in reconstructions of the hands and feet as tendon gliding material, but it is difficult to monitor its viability postoperatively. We have monitored such flaps by attaching a small preauricular skin flap 2 x 1 cm in size to the vascular pedicle. This preauricular island flap can be used as a "monitoring" flap.

Carcinoma, Squamous Cell↗
PubMed1996

Clinical and prognostic implications of bone lesions in childhood leukemia at diagnosis.

We studied 168 children with acute lymphoblastic leukemia (ALL) and 57 with acute nonlymphoblastic leukemia (ANLL) by retrospectively analyzing clinical symptoms, bone or joint involvement, and hematological findings to verify the clinical features and prognosis of children with acute leukemia who showed radiographic bone changes at the time of diagnosis. Of these, 36 with ALL (21.4%) and 6 with ANLL (10.5%) had symptoms referable to the bones or joints. Thirteen patients (7.7%) with ALL showed bone lesions radiographically. Phenotypically, 12 of the 13 had common ALL, 8 were incorrectly diagnosed and had received treatment for osteomyelitis or juvenile rheumatoid arthritis for 1 to 7 months prior to diagnosis of ALL. Leukocyte count was nearly normal with few or no blasts, and anemia and thrombocytopenia were mild or absent in all patients. Twelve of them remained in a complete remission for 26 to 148 months. Our data suggest that children with bone lesions related to acute leukemia exhibit clinical features that mimic infectious or collagen disease at diagnosis, and may belong to a subgroup of ALL with a better prognosis.

Adolescent↗
PubMed1996

[Occurrence of numerical aberrations of chromosomes in metachronous liver metastases of colorectal cancers].

To investigate the change of numerical aberrations of chromosome 17 or 18 during progression of Colorectal carcinoma, we applied FISH, using chromosome specific probes, to 3 colorectal primary carcinomas and a total of 4 metachronous metastatic lesions in the liver. We also investigated the relationship between the DNA content of whole nucleus and the number of chromosome 17 by multiparametric analysis using autostage cytofluorometry. When compared with the results for primary lesions, in 4 metastatic lesions, the population of tetrasomy 17 cells increased in 2 lesions, and that of monosomy 18 cells increased in 1 lesion. The nuclear DNA contents histograms for disomy 17 and aneusomy 17 cells analyzed individually for 3 primary and 4 metastatic lesions, showed almost no appreciable difference of peak DNA values. These results indicate that the numerical aberrations of chromosome 17 and 18 accumulate during the progression of colorectal carcinomas, and that the subpopulation of aneusomy 17 consist mainly of those cells that involve the numerical aberrations in a few chromosomes.

Chromosome Aberrations↗
PubMed1996

[Clonal analysis of hepatocellular carcinoma].

We investigated the cell clonality of 12 cases of female solitary hepatocellular carcinoma (HCC) that were associated with hepatitis virus infection. The clonal origin of HCC could be assessed by the method based on restriction fragment length polymorphism (RFLP) of X-chromosome-linked androgen receptor gene (AR) and phosphoglycerate kinase (PGK) gene, taking advantage of random inactivation of one of two X-chromosomes by methylation in females. We extracted DNA samples from both fresh and paraffin-embedded specimens of the same lesion as a source of DNA sample for polymerase chain reaction (PCR). Consequently, it was possible to use methylation-sensitive restriction enzymes and PCR to study differential methylation patterns among alleles of these genes for both DNA samples. The RFLPs of AR gene and PGK gene were found in eight of 12 cases and five of 12 cases, respectively. There were two cases which had no RFLPs in either AR gene or PGK gene. All cases of HCC which had RFLP in either AR gene or PGK gene demonstrated monoclonal origin of the tumor regardless of their histologic patterns.

Aged↗
PubMed1996

Clinicopathological evaluation of repeated courses of intravesical bacillus Calmette-Guerin instillation for preventing recurrence of initially resistant superficial bladder cancer.

PURPOSE: The efficacy of repeated courses of intravesical bacillus Calmette-Guerin (BCG) for superficial bladder cancer was assessed with particular attention to initially resistant cases. MATERIALS AND METHODS: A total of 75 patients with stages Ta to T1b superficial transitional cell bladder carcinoma received 6 weekly instillations of 80 mg. Tokyo strain BCG in 40 ml. saline followed by 6 instillations at monthly intervals. If tumors recurred, another course of treatment was given with surgery. RESULTS: Of 17 patients (22.7%) with recurrent tumor at followup periods of up to 84 months 12 received an additional course of BCG instillations according to the same protocol after transurethral resection of bladder tumors, and 10 (83.3%) showed no further recurrence with or without additional surgery and BCG therapy after a median followup of 42.9 months. Thus, the overall success rate with this approach was 90.7% (68 of 75 patients). Comparison of patients with and without recurrence revealed a significant difference in number of tumors before therapy (p < 0.05), and a pronounced tendency (p = 0.00507) for recurrence after prior systemic chemotherapy or intravesical instillation. CONCLUSIONS: The results suggest that up to 3 courses of repeated intravesical instillation of BCG are effective even for cases that initially did not respond, and that best results may be achieved if no other prior chemotherapy has been attempted.

Administration, Intravesical↗
PubMed1996

[Papillary muscle rupture complicating acute myocardial infarction--treatment with mitral valve replacement and coronary bypass surgery in acute phase].

Complete rupture of a papillary muscle following acute myocardial infarction is a severe complication that is typically associated with acute left ventricular failure, pulmonary edema, and relentless clinical deterioration. The reported mortality rates without surgical intervention is almost 90%, therefore, prompt operation without prolonged attempts at medical stabilization is the key to decrease operative mortality. Although the complete coronary revascularization in conjunction with mitral valve replacement is advocated in the western medical academic society, there is only a few case of conjunct surgery has been reported in Japan. Three successful cases of conjunct surgery of mitral valve replacement and coronary complete revascularization in acute phase within one week from the onset of acute myocardial infarction (AMI) are described. There were one male and two female patients with an average age of 60-year-old (range 48-67), who developed cardiogenic shock and admitted to our hospital. The average interval between onset of AMI and the appearance of mitral regurgitation (MR) was 38 hours, and that of the appearance of MR and admission was 40 hours. Surgeries were performed within 26 hours (average 13 hours) after admission. The mitral valve was replaced with a mechanical valve (St. Jude Medical Valve) and a complete coronary revasculatization was done using saphenous vein graft. The average period of operation time and aortic cross clamping time were 6 hours 22 minutes and 109 minutes respectively. The average number of coronary grafting was 2.3 (range 1-3). Postoperative recovery from cardiogenic shock was uneventful in all three patients. The average periods of ICU stay and hospital stay were 5 days and 43 days respectively. All patients have regained their social activities with mean follow up period of 52 months. Since ischemic heart disease remains the leading cause of death in such patients, it is suggested that complete coronary revascularization should be performed immediately in conjunction with valve replacement even in the acute phase after onset of AMI.

Aged↗
PubMed1996

Prostacyclin analog OP2507 prevents pulmonary arterial and airway constriction during lung preservation and reperfusion.

BACKGROUND: The effects of OP2507 on lung preservation with cold Euro-Collins solution and during the reperfusion period were evaluated. METHODS: For this study, canine lungs were flushed with a 10 micrograms/ml OP2507 solution (n = 7) or saline solution (control group, n = 7) (0.1 ml/kg body weight) and stored in the same solution. Pulmonary arterial pressure, pulmonary vascular resistance, airway pressure, respiratory capacity, and wet to dry weight ratio of the lungs were measured before and after 24 hours of cold preservation and after a 60-minute reperfusion period. RESULTS: Treatment with OP2507 significantly attenuated increases in pulmonary arterial pressure, pulmonary vascular resistance, and airway pressure after preservation and during the reperfusion period. Oxygen tension in outflow blood also was maintained with OP2507 treatment throughout the experimental period, whereas it was depressed during the reperfusion period in the control group. By electron microscopy, there was little evidence of vascular endothelial damage, such as cell swelling, detachment of endothelial cells from the lamina, and attenuation of the cytoplasm, in both groups. However, the tight junctions between cells were observed more clearly in the control group than in the OP2507 group, suggesting more cell membrane damage in the control group. CONCLUSIONS: Pretreatment with OP2507 prevented pulmonary artery and airway constriction after 12 hours of cold lung preservation and a decrease of oxygen tension in outflow blood during a 60-minute reperfusion period.

Animals↗
PubMed1996

Mechanism of mobilization of cadmium by dithiocarbamates in rat primary hepatocyte cultures.

The mechanism of mobilization of cadmium (Cd) by N-benzyl-D-glucamine dithiocarbamate (BGD) and N-p-hydroxymethylbenzyl-D-glucamine dithiocarbamate (HBGD) in rat primary hepatocyte cultures was studied. Probenecid pretreatment increased Cd efflux from the hepatocytes by BGD, but did not affect Cd efflux by HBGD. p-Aminohippurate treatment had no effect on Cd efflux by the chelating agents. These results suggest that an enhancing effect of probenecid on the BGD-induced Cd mobilization is due to its inhibitory effect on the glucuronidation of BGD and not its specific action on BGD transport. Verapamil and nicardipine had no effect on the chelating agent-induced Cd mobilization. Phlorizin did not affect Cd efflux by BGD or HBGD. Phloretin and cytochalasin B inhibited Cd efflux by the chelating agents. These results seem to be evidence that BGD and HBGD may be transported by a facilitated diffusion system in the hepatocytes.

Animals↗