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Biomedical subjects

M Umeda

Publications and source records attributed to M Umeda.

At least 235 records · Page 13Linked to original sources
PubMed1994

Expressed sequence tags from cultured cells of rice (Oryza sativa L.) under stressed conditions: analysis of transcripts of genes engaged in ATP-generating pathways.

Large-scale sequencing of randomly selected cDNA clones was used to isolate numerous genes in rice (Oryza sativa L.). Total RNA used for cDNA synthesis was prepared from suspension-cultured cells of rice grown under stressed conditions, such as in saline or nitrogen-starvation conditions. A total of 780 cDNA clones were partially sequenced and about 15% could be identified as putative genes. In the library constructed under saline conditions, we identified several genes associated with signal transduction, such as protein kinase and small GTP-binding protein genes. Many stress-related genes were isolated from both the saline and nitrogen-starvation libraries. These results indicate that stress treatment of suspension-cultured cells makes it possible to efficiently isolate various types of plant genes. To examine the usefulness of such tagged cDNAs for the study of gene expression in a specific metabolic pathway, we analyzed mRNA levels of genes engaged in the ATP-generating pathways in cultured cells of rice under different stresses, such as 20% sucrose, salt stress, cold stress and nitrogen-starvation stress. The results suggest that the coordinated induction of several genes in key steps under stressed conditions may be essential for activation of the entire energy-producing pathway to maintain homeostasis in rice cells. Expressed sequence tags identified by random cDNA sequencing provide the opportunity to generate a transcript map of rice genes.

Adaptation, Biological↗
PubMed1994

Retrotransposition of a plant SINE into the wx locus during evolution of rice.

A new type of plant retroposon, p-SINE1, has been found in the wx locus of rice (Oryza sativa). It has some structural characteristics similar to those of mammalian SINEs, such as members of the Alu or B1 family. In order to estimate the time at which the integration of p-SINE1 into a single locus occurred during rice evolution, we examined the distribution of two members of p-SINE1 in several species of the Oryza genus by the polymerase chain reaction (PCR). We found that one member of p-SINE1 (p-SINE1-r2) in the ninth intron of the wx+ gene was present only in two closely related species, O. sativa and O. rufipogon, and was not present in the other species carrying the AA genome within the Oryza genus. This result indicates that p-SINE1-r2 was integrated into the wx locus after O. sativa and O. rufipogon had diverged from other species with the AA genome. In contrast to p-SINE1-r2, another member (p-SINE1-r1) located in the untranslated 5'-region of the wx+ gene was present not only in all species with the AA genome but also in species with a different genome (CCDD). This result suggests that p-SINE1-r1 was integrated into that position prior to the genomic divergence. Thus, it appears that each member of p-SINE1 was retroposed at a specific site at a different time during rice evolution.

Base Sequence↗
PubMed1994

Estimation of remnant liver function before hepatectomy by means of technetium-99m-diethylenetriamine-pentaacetic acid galactosyl human albumin.

To improve the results of hepatectomy in cirrhotic patients, the likely reserve function of the liver was evaluated before surgery. Asialoglycoprotein receptor (ASGP-R) is a hepatic cell surface receptor specific for galactose-terminated glycoproteins. Technetium-99m-diethylene triamine pentaacetic acid-galactosyl human serum albumin (99mTc-GSA) is a newly developed analog ligand to ASPG-R. The probable functional reserve of the remnant liver after hepatectomy was estimated preoperatively as the hepatic binding protein (HBP) concentration specific for ASGP-R on the hepatocellular membrane of the remnant liver. This estimate was based on the effective liver volume rate, obtained by the uptake of 99mTc-GSA. In all, 3 normal volunteers, 3 patients with chronic hepatitis (CH), 9 patients with liver cirrhosis (LC), 2 patients with hepatic cystadenoma, 3 patients with hepatocellular carcinoma (HCC) associated with CH, and 21 HCC patients with LC were studied. The mean value +/- SD obtained for HBP in normal volunteers (three cases) and in patients with mild (four cases), moderate (two cases), and severe liver damage (five cases) were 0.74 +/- 0.03 microM, 0.43 +/- 0.042 microM, 0.31 +/- 0.05 microM, and 0.20 +/- 0.05 microM, respectively. Most of the cases in which the preoperative HBP of the remnant liver was above 0.22 microM had a good postoperative course irrespective of the type of hepatectomy. On the other hand, in subjects with a remnant liver HBP of between 0.22 and 0.11 microM, postoperative severe liver dysfunction occurred in about 50% of cases. In all cases with a remnant liver HBP below 0.1 microM, the prognosis was very poor, indicating that hepatectomy should be avoided. The HBP concentration detected by the 99mTc-GSA study is a very sensitive indicator of changes in the hepatic functional reserve, and the HBP value for the functional reserve of the remnant liver is extremely useful for estimating the liver function before and after hepatectomy.

Adult↗
PubMed1994

Improvement of ischemic myocardial dysfunction by nisoldipine.

We examined the cardioprotective effect of nisoldipine against myocardial dysfunction during ischemia and reperfusion in Langendorff perfused rabbit hearts. Nisoldipine was administered to the hearts before 60 minutes of global ischemia. This agent inhibited the increase of end-diastolic pressure during ischemia and also improved the recovery of left ventricular developed pressure and coronary flow during reperfusion in a concentration-dependent manner. The maximal cardioprotective effect was observed in 10(-8) M nisoldipine. The beneficial effect was associated with an increase of coronary flow during reperfusion. Therefore, both the nisoldipine-increased coronary flow during reperfusion and the inhibition of ischemic contracture by nisoldipine seem to play a crucial role in improving myocardial dysfunction of ischemic-reperfused hearts.

Animals↗
PubMed1994

Phosphorus-31 nuclear magnetic resonance in vivo spectroscopy of human liver during hepatitis A virus infection.

To evaluate the changes in hepatocellular phospholipid metabolism during hepatitis virus infection, 26 patients with acute viral hepatitis A were studied by means of phosphorus-31 nuclear magnetic resonance (31P-NMR) spectroscopy. The spectroscopy of liver showed six signal components in all patients as well as in the normal volunteers. During the early phase of illness, the phosphomonoester (PME)-phosphodiester (PDE) ratios in the patients became markedly greater than the ratios in the controls (P < 0.001). Within six weeks after the onset, the PME/PDE ratios returned to the level of controls. The time course analysis indicated an inverse correlation between the PME/PDE ratio and the period of time after onset (r = 0.738, P < 0.001). The spectral changes of human liver observed in acute viral hepatitis A are similar to those in the regenerating rat liver, indicating that 31P-NMR spectroscopy allows a noninvasive study of cell turnover in human liver disease associated with acute virus infection.

Acute Disease↗
PubMed1994

Primary malignant melanoma of the oral cavity--its histological classification and treatment.

In contrast to Caucasians, the Japanese population has a relatively high incidence of malignant melanoma in the oral cavity, but its classification and treatment has not been established up to now. We present here the detailed clinical and histological features of 14 cases of oral melanoma. In 13 of the 14 patients, the lesions exhibited three phases: a nodular phase consisting of spindle-shaped or epithelioid tumor cells in the submucosa, a pigmented plaque phase consisting of preinvasive tumor cell nests in the lower epithelial layers, and a macular phase consisting of proliferation of dendritic melanocytes without apparent atypia or simple hyperpigmentation in the basal cell layer. The macroscopic and microscopic findings of 13 melanomas corresponded to those of acral lentiginous melanoma of the skin, while the one lesion showing no radial growth phase was classified as nodular melanoma. We devised a new treatment plan for oral melanoma in 1980, which includes surgical excision via an intraoral approach, therapeutic neck dissection, and adjuvant immunochemotherapy. Out of 11 patients treated in this manner, nine had a good outcome without major cosmetic and functional morbidity. This suggests that the prognosis of oral melanoma is not so poor as reported previously if adequate therapy is provided.

Adult↗
PubMed1994

Establishment and characterization of a malignant melanoma cell line (YP-MEL) derived from a patient with neurocutaneous melanosis.

A cell line, YP-MEL, was established from an intracranial malignant melanoma occurring in a neurocutaneous melanosis (NCMsis) patient. The established cell line was successfully cultured in serum-free medium with a doubling time of 41 h. The cells were refractile and small in size, with occasional pigmented giant cells. Histochemical and immunohistochemical features were compatible with common malignant melanoma and its cell line. Chromosome analysis revealed many supernumerary chromosomes and marker chromosomes including double minutes (DMs). When transplanted into nude mice, YP-MEL formed tumors histologically consistent with the original tumor. Addition of sera to the medium caused cellular spreading and elongation of cytoplasmic processes with an increase of melanin contents and tyrosinase activity. Because there was no melanoma cell line derived from a NCMsis patient, YP-MEL might be a beneficial tool for study on NCMsis.

Biopsy↗
PubMed1994

A novel peptide probe for studying the transbilayer movement of phosphatidylethanolamine.

Ro09-0198 is a cyclic peptide isolated from Streptoverticillium griseoverticillatum which recognizes strictly the structure of phosphatidylethanolamine (PE) and forms an equimolar complex with the phospholipid on biological membranes. To use the peptide as a probe for analyzing the transbilayer movement of PE, we labeled the amino-terminal amino acid of the peptide with biotin without changing either the reactivity or specificity of the peptide. The amount of the peptide bound to the membrane was measured by enzyme linked immunosorbent assay (ELISA) after extraction of the peptide from the membrane. The peptide showed a strict temperature-dependent binding to human erythrocytes and the binding increased with increasing temperature. Since the peptide bound to PE in a temperature-independent manner and the binding to membrane PE is not affected by membrane proteins, the present temperature-dependent binding of the peptide to the cell membranes was likely to reflect temperature-dependent translocation of PE. The binding of the peptide to erythrocytes differed greatly among animal species. The peptide also showed temperature-dependent binding to a human histocytic lymphoma cell line, U937, suggesting that the peptide will provide a novel and convenient probe for analyzing the transbilayer movement of PE in eukaryotic cells.

Animals↗
PubMed1994

Marked stimulation of cell adhesion and motility by ladsin, a laminin-like scatter factor.

Ladsin is a large cell-adhesive protein with potent cell-scattering activity, which was recently identified in the culture of a malignant human gastric carcinoma cell line [Miyazaki, K. et al. (1993) Proc. Natl. Acad. Sci. USA 90, 11767-11771]. It is a heterotrimeric protein, containing a 140-kDa subunit similar or identical to the laminin B2t chain. Ladsin is similar to the keratinocyte-derived matrix proteins, "epiligrin" and "kalinin." In the present study, the cell-adhesion and cell-migration activities of ladsin were examined in comparison with those of three cell adhesion proteins, laminin, fibronectin, and vitronectin. Ladsin showed high cell-adhesion activity toward rat liver cell line BRL at concentrations 4-20-times lower than in the case of the other three proteins. In a monolayer culture, ladsin stimulated the migration of BRL cells about 2-times more strongly than the others, as compared at the minimal concentrations required for the maximal cell-adhesion activity. In Boyden chambers, ladsin stimulated both the chemotactic and chemokinetic migration of BRL cells. When the effect of anti-integrin antibodies on the adhesion of human fibrosarcoma cell line HT1080 was examined, the adhesion to ladsin was effectively inhibited by both the anti-integrin alpha 3 and beta 1 antibodies, but not the anti-integrin alpha 6 antibody, indicating that the primary receptor of ladsin is integrin alpha 3 beta 1. These results demonstrate that ladsin is a unique extracellular matrix component which may play a major role in cell migration.

Adult↗
PubMed1994

cDNA cloning and mRNA expression of a serine proteinase inhibitor secreted by cancer cells: identification as placental protein 5 and tissue factor pathway inhibitor-2.

A serine proteinase inhibitor was purified from conditioned medium of the human glioblastoma cell line T98G. Analysis of its partial amino acid sequences indicated that this protein was identical to placental protein 5 (PP5), a placenta-derived glycoprotein with serine proteinase inhibitor activity, the amino acid sequence of which had been partially determined. cDNA cloning of PP5 demonstrated that it belonged to the Kunitz-type serine proteinase inhibitor family, having three putative Kunitz-type inhibitor domains, and that it was identical to a recently reported inhibitor, tissue factor pathway inhibitor-2 (TFPI-2) [Sprecher et al. (1994) Proc. Natl. Acad. Sci. USA 91, 3353-3357]. PP5/TFPI-2 transcripts were highly abundant in the full-term placenta and widely expressed in various adult human tissues, such as the liver, skeletal muscle, heart, kidney, and pancreas. Several ovarian carcinoma cells as well as T98G also contained significant amounts of the transcripts.

Amino Acid Sequence↗
PubMed1994

Application of oriented poly-L-lactide screws for experimental Salter-Harris type 4 fracture in distal femoral condyle of the dog.

The clinical usefulness of biodegradable oriented poly-L-lactide (PLLA) screws for experimental Salter-Harris type 4 fracture in the distal femoral condyle of dogs was evaluated. Bony union of the osteotomized fragment of the condyle was almost completed radiographically and histologically within 1 to 2 months after surgery, suggesting that PLLA screws maintained strength long enough to fix the fragment until bone healing. At 4 to 6 months after surgery, minute fissures were histologically confirmed on the surface of the screw thread, suggesting the early stage of biodegradation and absorption of the polymer. During the observational period, no significant difference between the treated femur and the contralateral non-treated femur in either total femoral length or maximum condyle width was observed, indicating no growth disturbance in the treated femur. From these results it was concluded that the PLLA screw might be an ideal implant for the reduction and fixation of epiphyseal plate fractures such as Salter-Harris type 3 or type 4 fractures.

Animals↗
PubMed1994

[Lectin histochemical studies on the scent gland in the Syrian hamster and Mongolian gerbil].

The scent gland and ordinary sebaceous gland of Syrian hamsters and Mongolian gerbils were studied using lectin histochemistry. Male scent glands were larger in size than those of female in both species, but in histochemistry there was no distinct difference between both sexes. Histologically, the scent gland of Syrian hamsters had a strong resemblance to ordinary sebaceous glands, compared to that of Mongolian gerbils. Since the duct of Syrian hamsters was very short, it is difficult to distinguish the duct from the infundibulum. The duct and infundibulum of Mongolian gerbils were larger in diameter than those of Syrian hamsters. The duct widely opened to dermis. Seven lectins (ConA, RCA I, PNA, SBA, UEA-I, DBA and WGA) were used in this study. All of them labelled the differentiated cells of acinus in Syrian hamsters, although SBA did not label those cells in Mongolian gerbils. The cells of the duct in Syrian hamsters and Mongolian gerbils were not labelled with SBA. Ordinary sebaceous glands in both species were labelled with all seven lectins. Lectin-binding patterns of scent glands and sebaceous glands were similar in Syrian hamsters. While, in Mongolian gerbils, SBA-binding patterns were different between scent and sebaceous glands. Histologically, the scent gland of Syrian hamsters resembles the sebaceous gland. Therefore, there is a possibility that the scent gland of Syrian hamsters still provides some properties similar to sebaceous gland.

Animals↗
PubMed1994

A novel liposome immune lysis assay (LILA) for determination of CRP antigen using two monoclonal antibodies recognizing different antigenic determinants.

We have already developed the liposome immune lysis assay (LILA) for the determination of C-reactive protein (CRP) by employing an inhibition method and a sandwich method. We herein report a new LILA system involving the use of monoclonal antibodies-bearing liposomes. We established five monoclonal antibodies to CRP antigen, AC-1, -2, -3, -4, -5 which had the capacity to activate complement and form antigen-antibody complex. Each of these antibodies was covalently coupled to carboxyfluorescein-entrapped multilamellar liposomes. When the liposomes were incubated with CRP antigen in the presence of guinea pig complement, CRP antigen-dependent liposome lysis was observed but the sensitivity was not great enough for practical use. On the other hand, when liposomes coupling two monoclonal antibodies (AC-1, AC-2) which recognized distinct CRP antigenic determinants were employed in the assay, the sensitivity increased compared with that using only one monoclonal antibody, and the detectable concentration range was 5-300 ng/ml. These results indicated that the combination of two or more monoclonal antibodies which recognize distinct CRP antigenic determinants is effective for increasing the sensitivity of the assay.

Animals↗
PubMed1994

Clinical, bacteriological, and immunological examinations and the treatment process of two Papillon-Lefèvre syndrome patients.

Papillon-Lefèvre Syndrome (PLS) is a rare disease associated with the early onset of periodontal breakdown in deciduous and permanent dentition. The etiology of the destruction has not been completely clarified. Two female patients (ages 4 and 7 years) with severe destruction of the periodontal structures were examined. Except for palmar and plantar hyperkeratosis, dermatologic examination revealed no other medical disorders. On immunological analysis, measurement of serum antibody titers to 7 periodontopathic bacteria including Porphyromonas gingivalis and Actinobacillus actinomycetemcomitans was performed by enzyme-linked immunosorbent assay (ELISA). Further immunoblot analysis of A. actinomycetemcomitans and microbial culture of samples collected from deep periodontal pockets and mouthrinse solution were performed. The serum of the two patients showed high IgG titer against A. actinomycetemcomitans. Immunoblot results of the two patients against sonicated extract of A. actinomycetemcomitans Y4 strain exhibited a similar pattern. The band pattern differed from that observed in other forms of early onset periodontitis patients or periodontally healthy subjects. Moreover, A. actinomycetemcomitans colonies were cultured in high percentages from the pocket samples. Antibiotic therapy was instituted in addition to conventional periodontal therapy. In the younger patient, all deciduous teeth were extracted as part of the treatment and A. actinomycetemcomitans was no longer detected. All four permanent first molars and 8 permanent incisors subsequently erupted with healthy periodontium. However, the older patient did not improve after periodontal and antibiotic (minocycline and erythromycin) treatments and A. actinomycetemcomitans was consistently detected. Ofloxacin medication finally eliminated A. actinomycetemcomitans from the periodontal pockets. This antibiotic was also associated with reduced gingival inflammation and probing depth.(ABSTRACT TRUNCATED AT 250 WORDS)

Aggregatibacter actinomycetemcomitans↗
PubMed1994

Nucleotide sequence of rice (oryza sativa L.) cDNA homologous to cdc2 gene.

We isolated and determined a nucleotide sequence of a rice DNA clone (SS224) denoted to rcdc2. This clone encodes an open reading frame of 302 amino acids and typical three conserved domains that exist in all cdc2 homologues. The evolutionary tree showed that rcdc2 was far from cdc2 and its homologous genes identified in various plants.

Amino Acid Sequence↗
PubMed1994

[Therapy-related acute non-lymphocytic leukemia (M2) with 7;11 chromosome translocation induced into complete remission by low dose cytosine arabinoside and cytarabine ocfosfate therapy].

A case of therapy-related acute non-lymphocytic leukemia (t-ANLL) in a 70-year-old female patient is reported. An operation for lung cancer was performed in February 1991, and she was treated with etoposide (VP-16), a topoisomerase II inhibitor. Nineteen months after the start of chemotherapy, she complained of palpitations, and anemia and thrombocytopenia developed. The myelogram revealed 41.2% leukemic cells, and a diagnosis of t-ANLL induced by VP-16 was made. The karyotype of bone marrow cells showed 46, XX, t(7;11) (p13;p15), 16p+. She obtained complete remission (CR) by treatment with low dose cytosine arabinoside (Ara-C) and cytarabine ocfosfate (SPAC). Karyotype with t-ANLL induced by alkylate agents frequently shows unbalanced abnormalities. The difference of cytogenetic findings suggest the difference of mechanisms. Detailed chromosomal analysis make clear the oncogenesis of t-ANLL. It is reported that the prognosis of patients with t-ANLL treated by conventional chemotherapy is poor. Considering that elderly cases of acute leukemia have a lower probability of achieving CR than non-elderly cases, because of complications and side effects of chemotherapy such as bone marrow suppression, treatment with low dose Ara-C and SPAC is thought to be indicated in elderly patients with t-ANLL.

Aged↗
PubMed1994

[3 cases of elderly malignant lymphoma of the thyroid gland].

Chemotherapy and radiotherapy were performed on patients over 70 years of age with malignant lymphoma of the thyroid gland and complete remission (CR) was achieved in three patients who are reported here. Case 1: An 87-year-old woman who had been treated for Hashimoto's disease for 10 years as an outpatient was diagnosed as having a diffuse-small cell, B-cell type lymphoma by an aspiration biopsy of the tumor in the left thyroid. COP-BLAM chemotherapy followed by radiotherapy achieved CR. Case 2: A 71-year-old woman was referred to our department because of a right cervical tumor. A biopsy of the tumor revealed a diffuse medium-sized, B-cell type lymphoma. She also has been proved to have hypothyroidism. She entered CR after COP-BLAM chemotherapy combined with a radiotherapy. Case 3: A 76-year-old male patients with Hashimoto's disease who had been treated for 12 years at another outpatient clinic, presented with a right cervical tumor. Aspiration biopsy of the tumor yielded a diagnosis of B-cell lymphoma. COP-BLAM chemotherapy combined with radiotherapy achieved a CR. All three patients entered CR after chemotherapy combined with radiotherapy. Moreover, the microsome test and thyroid test also became negative after the combined modality therapy. In the future, there will probably be increases in the incidence of malignant lymphoma of the thyroid gland, due to the aging of society, and it will be necessary to establish methods of diagnosis and treatment for this disease.

Aged↗