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Biomedical subjects

M Ueda

Publications and source records attributed to M Ueda.

At least 757 records · Page 42Linked to original sources
PubMed1994

Hepatocyte growth factor and its variant with a deletion of five amino acids are distinguishable in their biological activity and tertiary structure.

A naturally occurring splice variant of hepatocyte growth factor (HGF) lacks a 5-amino acid sequence in the first kringle domain. Comparison of HGF and the deletion variant (dHGF) revealed that the deletion significantly altered the biological activities, solubility, and immunological property of HGF. HGF was respectively about 20-, 10-, and 2-fold more potent than dHGF in the stimulation of DNA synthesis in human umbilical vein endothelial cells, human aorta smooth muscle cells, and NSF-60 (murine myeloblastic cells). Conversely, dHGF was respectively about 3-, 2-, and 2-fold more potent than HGF in the stimulation of DNA synthesis in LLC-PK1 (pig kidney epithelial cells), OK (American opossum kidney epithelial cells), and rat hepatocytes. Moreover, HGF was over 70-fold more soluble than dHGF in PBS. Several monoclonal antibodies raised against dHGF recognized only dHGF and neither HGF nor reduced dHGF, demonstrating that the deletion caused a tertiary structural change. The structural change in HGF may be responsible for its altered biological activities and solubility.

Animals↗
PubMed1994

Triiodothyronine resuscitates the impaired liver function after Pringle's maneuver.

OBJECTIVE: To evaluate the changes in thyroid hormone levels and the effectiveness of exogenous triiodothyronine (T3) in shock caused by prolonged use of Pringle's maneuver (cross-clamping of hepatic triads). DESIGN: Pringle's maneuver was performed on dogs for 1 hour. In the T3 group (n = 7), 1 microgram/kg per hour of T3 was administered intravenously for 3 hours after declamping. In the control group (n = 7), the same volume of saline solution without T3 was administered. MAIN OUTCOME MEASURES: Serum T3, reverse T3, thyroxine, aspartate aminotransferase (AST), alanine aminotransferase (ALT), and the ketone body ratio (AKBR), which reflect the hepatic energy charge, were measured. Tissue blood flow, tissue blood velocity, and tissue blood mass of the liver were measured by means of a laser Doppler flowmeter. Oxygen saturation of the hemoglobin in the liver tissue was measured by tissue near-infrared spectroscopy. Dogs were observed until the seventh postoperative day. RESULTS: In the control group, the low T3 syndrome was observed. None of the dogs recovered from the shock and none survived for more than 24 hours. In the T3 group, all dogs recovered from the shock and survived. In the control group, hepatic tissue blood flow and oxygen saturation of hemoglobin in liver tissue were decreased, and the AKBR was deteriorated. In the T3 group, however, these parameters were markedly improved. CONCLUSION: It is suggested that T3 administration is beneficial in managing the critical resuscitation period of liver function after Pringle's maneuver is performed in dogs.

Alanine Transaminase↗
PubMed1994

Delay in expression of a mammary tumor provirus is responsible for defective clonal deletion during postnatal period.

A gene-encoding ligand for deletion of T cells bearing TcRV beta 6 and V beta 8.1 cosegregates a new mammary tumor provirus locus, Mtv-50 in NC mice. The sequence of the open reading frame (ORF) in the 3' long terminal repeat (LTR) of Mtv-50 was strikingly similar to those of Mtv-7, Mtv-43 and exogenous mouse mammary tumor virus (SW) with properties of minor lymphocyte stimulating antigen 1a. Consistent with previous reports, clonal deletion of mature thymocytes bearing TcRV beta 6 was defective during the early postnatal period of mice carrying Mtv-50. Appreciable levels of mRNA corresponding to common Mtv ORF and Mtv-6 ORF were expressed in the neonatal thymus, while little, if any, mRNA corresponding to Mtv-50 ORF was detected in the thymus at the early postnatal stage. Delay in expression of Mtv-50 ORF during the postnatal period may be responsible for the failure of clonal deletion of V beta 6-T cells in the early postnatal life of mice carrying Mtv-50.

Amino Acid Sequence↗
PubMed1994

Calcium-dependent neutral proteinase (calpain) in fracture healing in rats.

Calpain refers to Ca(2+)-dependent neutral cysteine proteinase, which originally was thought to be an intracellular proteinase but recently has been shown to function extracellularly as well. This report describes the immunohistochemical demonstration of calpain and biochemical changes in the amount of calpain during fracture healing in rats. The tibiae of 6-week-old Wistar rats were fractured, and calluses were obtained 5-28 days after fracture. A frozen section of the fracture callus was stained by the immunoperoxidase method with use of polyclonal antibodies of calpains I and II. Positive staining was noted with the anti-calpain II antibody in the perivascular areas, chondrocytes, and cartilage matrix in calluses at 5, 7, and 10 days. Less intense staining was seen in older calluses. The caseinolytic activity of calpain II reached its maximum on the 5th day, was high on the 7th and 10th days, and decreased rapidly thereafter. The quantity of calpain II was dependent on the process of fracture healing. It was concluded that calpain was working as one of the matrix proteinases in fracture callus.

Animals↗
PubMed1994

Preclinical studies using immobilized OKT3 to activate human T cells for adoptive immunotherapy: optimal conditions for the proliferation and induction of non-MHC-restricted cytotoxicity.

In order to obtain large numbers of T cells for adoptive immunotherapy after bone marrow transplantation (BMT), we optimized conditions for long-term proliferation of T cells that exhibit non-MHC-restricted cytotoxicity using immobilized anti-CD3 (OKT3) activation and culture in IL-2. Proliferation and cytotoxicity directed at Daudi, K562, and B cell lines were used to determine (1) the optimal concentration of IL-2 and the optimal time of exposure to immobilized OKT3 for maintaining growth and cytotoxicity, (2) the starting populations that can be used, (3) the T cell subsets that mediate cytotoxicity, and (4) the optimal medium and concentration of serum for maintaining growth and cytotoxicity. Peripheral blood lymphocytes (PBL) activated with OKT3 would proliferate and mediate cytotoxicity at IL-2 doses as low as 30 IU/ml. Increasing the IL-2 concentrations beyond 600 IU/ml did not augment the proliferative or cytotoxic responses of PBL. A 24-hr incubation on OKT3 was sufficient to activate PBL. Increasing the incubation time on OKT3 from 24 to 72 hr did not significantly enhance cytotoxicity. Comparisons between PBL and purified T cells (E-rosette) indicated that either cell population could be activated with OKT3 in the presence of IL-2 to proliferate and mediate non-MHC-restricted cytotoxicity. Purified populations of CD4+ or CD8+ T cells demonstrated equivalent proliferation and cytotoxicity when activated using IL-2 and OKT3. With equal concentrations of human or fetal bovine serum, RPMI 1640 and X-Vivo 10 were comparable for supporting proliferation and cytotoxicity. These conditions are being used to activate and expand T cells for clinical trials that involve infusing activated T cells into recipients after autologous BMT.

Blood Physiological Phenomena↗
PubMed1994

N-glycosylation of erythropoietin is critical for apical secretion by Madin-Darby canine kidney cells.

Erythropoietin (Epo) has three N-linked carbohydrate chains at positions 24, 38, and 83 in its 166-amino acid residues. When the human wild-type Epo was expressed in the polarized Madin-Darby canine kidney (MDCK) epithelial cells, Epo was preferentially secreted from the apical domain. The polarized secretion was perturbed by the treatment of the cells with tunicamycin, suggesting the involvement of N-linked carbohydrate chains in the apical sorting mechanism in MDCK cells. Replacement of asparagine residues at all N-glycosylation sites of Epo with glutamine by site-directed mutagenesis resulted in roughly equal secretion from apical and basolateral domains. Comparative studies on MDCK clones expressing the mutant Epos lacking one or two of the three N-glycosylation sites in every possible combination showed that the N-linked carbohydrate chain at position 38 is critical for the polarized secretion. Nocodazole, a microtubule-disrupting drug, reversed the polarized secretion of the wild-type Epo from the apical to basolateral preference with little change in the total secretion. Hepatocyte growth factor, a scatter factor known to induce the tubule-like structure of MDCK cells, caused almost equal secretion of the wild-type Epo into the apical and basolateral sides, although the tight junctions of MDCK cells remained intact.

Animals↗
PubMed1994

Conservative therapy for microinvasive carcinoma of the uterine cervix.

The purpose of this study was to evaluate conservative therapy for microinvasive carcinoma (MIC) of the cervix. Large contact Nd-YAG laser conization (laser cone) with contact vaporization using contact probes was performed on 90 cases of MIC and 21 cases of early invasive carcinoma (early IC), with long-term postoperative follow-up for patients at Osaka Medical College, Osaka, Japan. The cure rates of MIC and early IC were 96.7 and 80.9%, respectively. The rates of incomplete excision and true residuation in cases with MIC were 17.8 and 10.0% and those in cases with early IC were 76.2 and 19.0%. Therefore, the spontaneous cure rate following incomplete excision of MIC and early IC was 43.7 and 75.0%. Hysterectomy was performed, for various indications, after cone in 5 patients (5.6%) with MIC, none of the patients with IC of less than 3 mm, 2 (22.2%) of the patients with IC of 3.1 to 5 mm, and 7 patients (87.5%) whose IC was 5.1 mm or more in depth. Combining the data from our department and those in the literature collected an incidence of lymph node metastasis of 0.15% for MIC and of 1.13% of IC of less than 5 mm. In conclusion, conservative therapy is indicated for MIC, and the contact laser cone with contact vaporization is considered to be an excellent therapeutic conservative method.

Adult↗
PubMed1994

Peptide synthesis with halophenylalanines by thermolysin.

Thermolysin was able to catalyze enantioselective peptide synthesis with non-natural amino acids, halophenylalanines. However, the reactivity of thermolysin was considerably influenced by the kind and position of halogen substituents on these analogues. The manner of the recognition of the amino component by the enzyme was different from that of the carboxyl component in the synthesis of peptides with non-natural phenylalanine analogues. The phenomena observed are discussed, based on the kinetic parameters obtained.

Amino Acid Sequence↗
PubMed1994

Characterization of the catalase of the n-alkane-utilizing yeast Candida tropicalis functionally expressed in Saccharomyces cerevisiae.

Candida tropicalis catalase (CTC) genomic DNA was recombined on a plasmid with the galactose-inducible GAL7 promoter and expressed highly as a heme protein in Saccharomyces cerevisiae as host. The percentage of recombinant CTC (rCTC) in total extractable protein amounted to at least 25%. The rCTC was purified and characterized in terms of subunit mass, behavior in native polyacrylamide gel electrophoresis, absorption spectrum, amino-terminal amino acid sequence, peptide map, specific activity, and Michaelis constant (Km) value for hydrogen peroxide. These properties were similar or identical to those of the purified enzyme from C. tropicalis (CTC). From these results, this system appears suitable for high expression of functional catalase protein having heme.

Base Sequence↗
PubMed1994

Ultrastructural and immunohistochemical characterization of basal cells in three-dimensional culture models of the skin.

Keratinocytes were cultured on fibroblast-free dermal substitutes made of type I collagen film (collagen dermal substitute) and an extracellular matrix gel film (matrix dermal substitute), each of which was laid on a lyophilized type I collagen sponge. The morphology of the basal keratinocytes in these three-dimensional culture models of the skin was studied ultrastructurally and immunohistochemically to assess their differentiation to basal cells. The basal keratinocytes in the artificial epidermis cultured on the collagen dermal substitute showed poorly organized tonofibril networks and desmosomes. Neither the tonofibril-hemidesmosome complex nor the lamina densa were detected along the interface, where many cytoplasmic projections of basal keratinocytes were noted. There were no detectable antigens of type IV or VII collagen, LDA-1, or laminin in the interface. Bullous pemphigoid (BP) and 1-2B7B antigens and integrins were expressed along the cytoplasmic membrane and the projections of the basal keratinocytes. A high molecular weight keratin (keratin 1, 68 kDa, 34 beta B4) was detected only in part of the uppermost layers of this artificial epidermis. In contrast, basal keratinocytes in the artificial epidermis on the matrix dermal substitute developed tonofibril networks radiating to desmosomes and hemidesmosomes, under which a primitive lamina densa was present. Basement membrane zone antigens, such as type IV and VII collagens, LDA-1 and laminin were noted along the interface as were 1-2B7B and BP antigens and integrins. Laminin and type VII collagen were also detected along or in the membrane of the endoplasmic reticulum of basal keratinocytes.(ABSTRACT TRUNCATED AT 250 WORDS)

Basement Membrane↗
PubMed1994

M-VEC (methotrexate, vinblastine, epirubicin, and cisplatin) with granulocyte colony-stimulating factor for the treatment of urothelial cancer: an effective and safe chemotherapy regimen.

The toxicity of combination chemotherapy is significant, with the most prominent side effect being myelosuppression. To reduce the toxicity, we used a recombinant human granulocyte colony-stimulating factor (rhG-CSF). A total of 52 patients were enrolled in this study. The sites of tumor involvement included the urinary bladder in 24 patients, the renal pelvis in 5, the ureter in 4, lymph nodes in 11, bone in 4, the lung in 1, and miscellaneous sites in 4 patients. The chemotherapy was given in 21-day cycles as follows: 30 mg/m2 methotrexate was given intravenously on day 1, and approximately 24 h later, 3 mg/m2 vinblastine, 30 mg/m2 epirubicin, and 70 mg/m2 cisplatin were given intravenously. The rhG-CSF (2 micrograms/kg per day) was injected subcutaneously on days 3-16 of each cycle. All patients received full doses of the antineoplastic agents on time according to the protocol design. The response rates were 61% for primary sites, 55% for lymph nodes, 0 for bone, and 67% for miscellaneous sites. Of 42 patients evaluated, 5 (12%) achieved a complete response and 20 (48%) achieved a partial response, for an overall response rate of 60%. Of the 42 patients, 27 (64%) are alive, and the median duration of survival is 14 months. The mean nadir white blood count was more than 5,600 cells/mm3. The incidence of mucositis in the total toxic symptoms was low. There was no cardiac toxicity or drug-related death. These results indicate that the present combination chemotherapy with coadministration of rhG-CSF is an effective and safe regimen for the treatment of urothelial cancer.

Adenocarcinoma↗
PubMed1994

Age and sex-dependent alterations of serum amylase and isoamylase levels in normal human adults.

Total amylase and salivary- and pancreatic-type isoamylase levels were assayed in sera from 606 apparently healthy adults of different sex and age groups. There were significant differences in both total amylase and isoamylase levels, depending on age and sex, one of the characteristics being that levels of these three enzymes were significantly higher in the elderly group in both men and women than in other age groups. Another feature was that all of these enzyme levels were significantly greater in women in the third and fourth decade than in men. Age and sex differences should be taken into consideration in the evaluation of mild hyperamylasemia.

Adolescent↗
PubMed1994

An ultrastructural study of extracellular fibrillar components of developing mouse mandibular condyle with special reference to type VI collagen.

The localization of type VI collagen was examined from birth to 8 weeks of age. Immunohistochemical staining with anti-type VI collagen antibody was strongly positive in the hypertrophic zone and moderately positive in the fibrous zone and the outer periphery of the proliferative zone, but negative in the inner area of the proliferative zone and mature zone. After ATP treatment, type VI collagen periodic fibrils with about 80-nm intervals were frequently observed but only in the fibrous zone. They occurred mainly in the superficial area of this zone, where striated collagen fibrils were sparse, while a few were noted in the inner area, where bundles of collagen fibrils were abundant. From these distributional differences of both components, a subzonation of the fibrous zone into superficial and inner area is suggested. Moreover, with ATP treatment there were fewer type VI collagen periodic fibrils formed with increasing age (8 weeks). Testicular hyaluronidase digestion before ATP treatment facilitated the formation of periodic fibrils, in all the ages examined, in the intercellular space and around the fibroblastic cells. The interaction of type VI collagen with other components such as collagen fibrils, glycosaminoglycans or proteoglycans may play a part in maintaining the structural integrity of extracellular matrix in the mouse mandibular condyle.

Adenosine Triphosphate↗
PubMed1994

Altered production of nerve growth factor in aganglionic intestines.

Nerve growth factor (NGF), a target-derived neurotrophic molecule, is required specifically by sympathetic and dorsal root ganglion cells for their survival and maturation during embryonic and early postnatal development. In the present study, the NGF expression was studied both at the protein and mRNA level in normal and aganglionic intestines of Piebald-strain mice and also in 10 human specimens using immunohistochemical and reverse transcriptase polymerase chain reaction (RT-PCR) techniques. In the aganglionic intestines of the mice, immunoreactive NGF was found on the giant nerve fibers in the submucosal layer, but not found in the mucosal layer. In the mRNA study, the signal for NGFmRNA was less intense in the aganglionic rectum of the congenitally megacolonic mice than in the rectum of the normal mice. In contrast, the distal dilated colon of the congenitally megacolonic mice had a more intense signal for NGFmRNA than did the colon of normal mice. The results obtained from human specimens were compatible with the findings in the Piebald mice; the distal colons harvested from the patients with Hirschsprung's disease (or its allied disease) had a uniformly more intense signal for NGFmRNA than did the normal colons. The results of this study may indicate that NGF production is altered in the aganglionic intestines and also in the "transitional zone" in Hirschsprung's disease. The altered production of NGF may be useful in increasing the accuracy of diagnosis of Hirschsprung's disease.

Animals↗