PubMed Health⌕ Search

Biomedical subjects

M Umeda

Publications and source records attributed to M Umeda.

At least 19 recordsLinked to original sources
PubMed1992

Different ability in PC12 clones to recover from MMC toxicity following NGF treatment.

PC12 cells were cloned, and from their ability to form neurite-like processes 3 clones were selected: NGF-highly sensitive clone (HS), -moderately sensitive clone (MS), and -insensitive clone (IS). These clones were tested for the presence of specific NGF receptors by measuring the binding of 125I-labeled NGF. All 3 clones were capable of binding NGF, but the HS clone had more NGF receptors than the MS and IS clones. The effects of methyl mercuric chloride (MMC) and/or nerve growth factor (NGF) on these clones were tested. The HS clone was a little more susceptible to MMC than the MS and IS clones. When NGF was added to the culture medium in addition to MMC, cell recovery was observed. The tendency toward recovery was more prominent in the HS clone than in the IS one. Recovery in the MS clone was intermediate. These results suggest that NGF treatment can contribute to functional recovery of PC12 cloned cells from the cytotoxic effects of MMC depending on their ability to react to NGF.

Animals↗
PubMed1992

Secretion of cell-adhesion-promoting factors, fibronectin, fibronectin fragments and a 53-kDa protein, by human rectal adenocarcinoma cells.

Production of cell-adhesion proteins was examined in 10 cell lines and 5 cultured human cancer cells at an early passage. Two-thirds of the tested cells produced and secreted into their culture medium variable amounts of material active in promoting cell attachment. One of the rectal carcinoma cell lines, CaR-I, grew well in serum-free medium and secreted a large amount of the active principle. The active principles produced by CaR-I cells were characterized after partial purification, and were found to be fibronectin and its fragments. The presence of fibronectin and its fragments was proved by the following facts: (1) reactivity to the monoclonal antibodies which recognize different epitopes of fibronectin, and (2) reactivity to RGD peptide which is the attachment sequence of fibronectin. In addition to fibronectin and its fragments, CaR-I cells were also shown to produce a 53-kDa attachment factor. Unexpectedly, the protein was proved to be most probably the p53 suppressor gene product.

Adenocarcinoma↗
PubMed1992

Multiple secretion of matrix serine proteinases by human gastric carcinoma cell lines.

Proteinase species secreted by 10 human gastric carcinoma cell lines were analyzed by gelatin zymography and immunoblotting. These cell lines were classified into the following three groups with respect to proteinase secretion: cell lines secreting mainly gelatinases A and/or B; those secreting multiple types of serine proteinases; and those scarcely secreting these enzymes. Two cell lines of the second group, STKM-1 and MKN28, hardly secreted metalloproteinases but secreted the following four types of serine proteinases: (a) two trypsin-like enzymes (M(r) 26,000 and 24,000 in proenzyme forms); (b) a tissue kallikrein-like enzyme (M(r) 150,000 in a complex form); (c) a plasmin-like enzyme (M(r) 70,000); and (d) a plasminogen activator (urokinase-type, M(r) 57,000, from STKM-1 and tissue-type, M(r) 70,000, from MKN28). The M(r) 70,000 plasmin-like enzyme was also detected at lower levels in the conditioned media of four other cell lines (MKN1, MKN45, NUGC-3, and KATO III). The M(r) 24,000 proenzyme of the trypsin-like enzyme was purified from the serum-free conditioned medium of STKM-1. The proenzyme was activated by enterokinase treatment or autolytically by incubation at neutral pH, decreasing its apparent molecular weight from 24,000 to 23,000 on nonreducing sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The activated enzyme extensively degraded fibronectin, laminin, and gelatins and to lesser extents type I, III, IV, and V collagens at 30 degrees C. These results suggest that the matrix serine proteinases may play a major role in the matrix degradation by some kinds of human cancer cells.

Blotting, Western↗
PubMed1992

Activation of TIMP-2/progelatinase A complex by stromelysin.

Progelatinase A was purified as a complex with TIMP-2 from the conditioned medium of a human glioblastoma cell line. The TIMP-2/progelatinase complex was resistant to the activation by p-aminophenylmercuric acetic acid (APMA), and showed less than 10% of the activity of the TIMP-2-free active enzyme. When the complex was incubated with stromelysin in the presence of APMA, the 64-kDa progelatinase was effectively converted to the 57-kDa mature enzyme, increasing its gelatinolytic activity about 8-fold. These results suggest that stromelysin is a natural activator of TIMP-2-bound progelatinase A.

Cell Line↗
PubMed1992

Induction of 103-kDa gelatinase/type IV collagenase by acidic culture conditions in mouse metastatic melanoma cell lines.

Gelatinases/type IV collagenases have been shown to be involved in tumor invasion and metastasis. In this study, we examined the effect of culture medium pH on the secretion of the gelatinases from mouse B16 melanoma cell lines and human tumor cell lines using zymography analysis. The highly metastatic clone F10 of B16 melanoma did not secrete any gelatinase in neutral culture media (pH 7.1-7.3), whereas it secreted a high level of a 103-kDa gelatinase in an initial pH range of 5.4-6.1. The addition of an excess amount of glucose into a neutral culture medium also induced the gelatinase secretion from the cells by decreasing the medium pH during incubation. The extent of the acid-induced gelatinase secretion by the B16 melanoma cell lines was in the order of BL6 greater than F10 greater than F1 much greater than the parent B16 line, in good agreement with the order of their metastatic potentials. Two human cell lines (A549 and HT1080) secreted a higher level of a 90-kDa gelatinase at pH 6.8 compared with pH 7.3. The acid-induced gelatinase secretion from B16-F10 cells was blocked by cycloheximide, indicating that the enzyme induction was due to de novo synthesis. When in vitro tumor cell invasion was assayed in Boyden chambers, B16-F10 cells incubated in an acidic medium exerted a more active migration through type IV collagen gel than those in a neutral medium. These results suggest that the acidic environment formed around tumor tissues may be an important factor in invasion and metastasis of some types of tumors.

Animals↗
PubMed1992

Comparison of extracellular matrix-degrading activities between 64-kDa and 90-kDa gelatinases purified in inhibitor-free forms from human schwannoma cells.

Two kinds of gelatinases (or type IV collagenases), 90-kDa and 64-kDa gelatinases, were purified in a tissue inhibitor of metalloproteinases (TIMP)- or TIMP-2-free form from the serum-free conditioned medium of human schwannoma YST-3 cells, and their activities on extracellular matrix proteins were compared. Sequential chromatographies on a gelatin-Sepharose column, an LCA-agarose column, and a gel filtration column in the presence of 5 M urea yielded 600 micrograms of the 64-kDa enzyme and 45 micrograms of the 90-kDa enzyme from 2.8 liters of the conditioned medium. The purified enzymes showed high gelatinolytic activities without activation by p-aminophenyl mercuric acetate (APMA), indicating that 5 M urea used in the final chromatography not only dissociated the inhibitors from the progelatinases but also activated the proenzymes. The inhibitor-free gelatinases showed a much higher activity than the APMA-activated inhibitor-bound enzymes. The specific activity of the 90-kDa enzyme was nearly 25 times higher than that of the 64-kDa enzyme. The 90-kDa gelatinase hydrolyzed type I collagen as well as native and pepsin-treated type IV collagens at 30 degrees C, while at 37 degrees C it potently hydrolyzed types I, III, and IV collagens but not fibronectin or laminin. The 64-kDa gelatinase showed a similar substrate specificity to that of the 90-kDa enzyme, except that it did not hydrolyze type I collagen and native type IV collagen at 30 degrees C.

Collagen↗
PubMed1992

Detection of three distinct phospholipases A2 in cultured mast cells.

Phospholipase A2 activity in lysates of mast cells such as rat mastocytoma RBL-2H3 cells and mouse bone marrow-derived IL-3-dependent mast cells (BMMC) was measured using phosphatidylcholine (PC), phosphatidylethanolamine (PE), or phosphatidylserine (PS) as a substrate. Both types of cells exhibited phospholipase A2 activity with a similar pH profile; the optimum pH observed with PS as a substrate was 5.5-7.4, whereas that with PE or PC was 8.0-9.0. PE and PC bearing an arachidonate at the sn-2 position were cleaved more efficiently by PE, PC-hydrolyzing phospholipase A2 than phospholipids with a linoleate. A monoclonal antibody raised against rabbit platelet 85-kDa cytosolic phospholipase A2 absorbed the PE, PC-hydrolyzing activity. PS-hydrolyzing activity was purified from RBL-2H3 cells and BMMC by sequential heparin-Sepharose, butyl-Toyo-pearl, and reverse-phase HPLC. On reverse-phase HPLC, the PS-hydrolyzing activity of RBL cells was separated into two peaks, A and B. The peak B activity was inhibited by the anti-rat 14-kDa group II phospholipase A2 antibody, while the peak A activity was not. The partially purified peak A activity hydrolyzed PS about 10-fold more efficiently than PE at optimum pH of 5.5-7.4. No appreciable hydrolysis was observed with PC or phosphatidylinositol (PI). Thus, mast cells may express at least three distinct phospholipases A2; 14-kDa group II phospholipase A2, 85-kDa cytosolic arachidonate preferential phospholipase A2, and a novel phospholipase A2 that shows high substrate specificity for PS.

Animals↗
PubMed1992

Isolation of subclones with different tumorigenicity and metastatic ability from rat nephroblastoma cell line, ENUT.

Seven subclones derived from a chemically induced rat nephroblastoma cell line, ENUT, were isolated and their cytological characteristics were examined in order to investigate the biological nature of the parent tumor. The subclones were divisible into two types based on morphological and biological features: polygonal cells with well developed junctional complexes and less developed cell surface microvilli, showing a doubling time of 13.0 to 14.0 h and tumorigenicity in nude mice of 42-100%, and spindle-shaped cells with poorly developed junctional complexes and well developed microvilli, showing a doubling time of 9.7 to 12.2 h and 100% tumorigenicity. Potential for both spontaneous and experimental metastasis to the lungs was apparently higher in the spindle-shaped clones than in the polygonal clones. In spite of their differing characteristics, the cytochemical phenotypes of the two clonal types were almost identical to those of immature renal tubules of the developing fetal kidney. The present findings suggest that these subclones possess characteristics of early nephrogenic epithelial cells, and we speculate that the biological differences observed among the subclones may be explained by differences in malignant progression. In addition, these clones appear to be a useful model for the study of tumorigenicity and metastasis.

Animals↗
PubMed1992

Monoclonal antibody analysis of phosphatidylserine and protein kinase C localizations in developing rat cerebellum.

Understanding the topographical relationships between phosphatidylserine (PS) and protein kinase C (PKC) within neurons can provide clues about the mechanism of translocation and activation of PKC. For this purpose we applied monoclonal antibodies (Abs) of PS and PKC to sections of developing rat cerebellum. The anti-PKC Ab immunohistochemical pattern showed homogeneous staining of Purkinje cells over various postnatal ages, whereas the anti-PS Ab staining showed a heterogeneous localization over these ages. Purkinje cells did not stain well between postnatal day 14 (PND 14) and PND 21, suggesting that the PS was lost from the membrane during preparation of the sections during this period. These data imply that interactions between PS and PKC vary in Purkinje cells during postnatal development.

Aging↗
PubMed1992

Characterization of a plant SINE, p-SINE1, in rice genomes.

We have previously found that a short interspersed element (SINE), named p-SINE1, is present in the Waxy gene of Oryza sativa in two copies. Here, we cloned five members of p-SINE1 located at other loci in O. sativa and determined their nucleotide sequences. These sequences had a T-rich pyrimidine tract at their defined 3' end and were flanked by direct repeats of a sequence of mostly 14-15 bp long like p-SINE1s in the Waxy gene. The consensus sequence derived from total seven members of p-SINE1 was 123 bp in length and had an internal promoter region for RNA polymerase III. The 5'-half region of the sequence was partially homologous to the tRNA-related block of rabbit C family, one of SINEs in the animal system. Two of the seven p-SINE1 members were not present in the corresponding loci in African rice, Oryza glaberrima, and may thus be available for classification of some rice strains. Comparison of the nucleotide sequences of the Waxy gene between O. sativa and O. glaberrima showed that base substitutions have frequently occurred in a p-SINE1 member (p-SINE1-r1) and a transposable element Tnr1 also present in the Waxy gene, suggesting that these elements, which appear as repetitive sequences in the rice chromosome, tend to acquire base substitutions at a higher frequency than do unique sequences.

Base Sequence↗
PubMed1992

[Improvement of pituitary homograft under the kidney capsule in mice].

The model of hyperprolactinemia induced by pituitary homografts under the kidney capsule has been used mainly in the field of reproductive physiology. The authors report an improved method for pituitary grafting in mice. The procedure was as follows: 1. The male pituitary glands with normal saline were aspirated into a polyethylene tube. 2. Two incisions were made in the kidney capsule. 3. The polyethylene tube with pituitary glands was inserted via a large incision. 4. Blowing air into the tube, the pituitary glands were left under the kidney capsule and normal saline streamed out of a small incision. Using this method, all pituitary grafted mice became pseudopregnant.

Animals↗
PubMed1992

Characterization of experimental rat nephroblastoma and its cell line.

Rat nephroblastoma (Wilms' tumor) was induced by transplacental administration of N-ethyl-nitrosourea (ENU). The induced renal tumors were histologically compatible with human nephroblastoma. A cultured cell line (ENU-T-1) established from a xenotransplant, showed similar morphological and biological features to cultured embryonal kidney cells. Introduction of normal human chromosome #11 (#11) bearing Wilms' tumor suppressor gene(s) (WT) suppressed colony-forming ability on soft agar plates (CFA) but tumorigenicity of ENU-T-1 was not affected. Whereas tumorigenicity of human nephroblastoma cell line, SK-NEP-1 was completely suppressed, CFA was unchanged. These facts indicated that pathogenetic mechanism is different between human and experimental rat nephroblastomas.

Animals↗
PubMed1992

[Clinical studies of recombinant human granulocyte colony-stimulating factor in elderly patients with malignant lymphoma].

Recombinant human granulocyte colony-stimulating factor (rhG-CSF) was given in combination with chemotherapy in elderly patients (greater than or equal to 65 years old) with malignant lymphoma, and the therapeutic efficacy and the incidence of side effects were determined. The subjects consisted of 5 males and 8 females with a median age of 74 years. One patient had Hodgkin's disease and 12 had non-Hodgkin's lymphoma. Regarding lymphoma stage, 2 were in stage II, 3 were in stage III, and 8 were in stage IV. The chemotherapy used was COP-BLAM in 8 patients, COP-BLAM III in 2, IMV-triple P in 2, and ACVP-16 in 1. Treatment with rhG-CSF (1.5 micrograms/kg/day) was commenced during or after the 2nd course of chemotherapy when the neutrophil count dropped to greater than or equal to 1,000/microliters, and was continued until the recovery of either the neutrophil or leukocyte count to 10,000/microliters or 20,000/microliters, respectively. The neutrophil nadir in the non-G-CSF group was 367.3 +/- 231.6/microliters. In the G-CSF group it was 754.6 +/- 116.4/microliters for the second course, with the difference between the 2 groups being significant (p less than or equal to 0.05). Also, the following time periods were significantly shorter in the G-CSF group than the non-G-CSF group: 1) the duration of a neutrophil count less than 1,000/microliters, 2) the duration of fever (greater than or equal to 37.5 degrees C), and 3) the time to recovery from the neutrophil nadir.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

[Non-Hodgkin's lymphoma in an elderly patient complicated by cyclophosphamide-induced allergic hepatic dysfunction].

A 77-year-old male presented at our Department of Urology in August 1990 with a gradually enlarging swelling in the right scrotum. On August 21, right high orchietomy was performed. This was diagnosed histologically as non-Hodgkin's lymphoma (diffuse large cell type), and the patient was transferred to our department on September 11 for further examination and treatment. As enlargement of the lymph nodes around the abdominal aorta was evident, it was diagnosed as stage IIA according to the Ann Arbor Classification. Beginning on September 21, three courses of COP-BLAM therapy (CPM, VCR, PDN, BLM, ADR, PCZ) were administered (the third course started on November 8) to achieve complete remission. Hepatic dysfunction appeared, however, from November 16, and by November 19, GOT and GPT increased to 6700 and 2120, respectively, with aggravation of jaundice. PDN therapy was instituted, and GOT and GPT improved gradually, but jaundice did not improve. On December 22, laparoscopy was performed, and liver biopsy produced histologic findings of drug-induced hepatitis. Further, lymphoblastic response was positive for CPM. Hepatic failure occurred on December 29, and plasma exchange was performed, but it failed to improve the condition, and the patient died on January 15. We described a case of non-Hodgkin's lymphoma complicated by hepatic dysfunction, probably induced by CPM, in an elderly patient who died to hepatic failure.

Aged↗
PubMed1992

[Elderly non-Hodgkin's lymphoma presenting with pulmonary squamous cell carcinoma as a complication of chemotherapy for malignant lymphoma].

The authors report a case of pulmonary squamous cell carcinoma which occurred after chemotherapy of non-Hodgkin's lymphoma (NHL). A 76-year-old man, who was admitted to our department because of swelling of cervical lymph nodes, was diagnosed as having NHL (follicular mixed cell lymphoma). He was treated with 11 courses of CHOP therapy. Thereafter, chemotherapy including ifosfamide was carried out for approximately three years. In June, 1991, he was readmitted to our department because of swelling and pain in his left thigh and an abnormal shadow on chest X-ray. Chest CT demonstrated a cavitated shadow (about 5 cm in diameter) with an irregular margin in right S1, which was suggested to be lung cancer or pulmonary infiltration of malignant lymphoma. Bronchoscopy, which was carried out on July 12, showed bloody sputa from the right B1 ramus and markedly reddened mucosa at the orifice of the right upper bronchus. Sputum cytology revealed no malignancy. ACVP-16 chemotherapy including ara-C, CBDCA and VP-16 was initiated on July 14 because of enlarged superficial lymph nodes. On July 18, he fell out of bed and fractured his left femur. He also suffered from respiratory failure. He died of pulmonary haemorrhage on July 26. Autopsy revealed pulmonary squamous cell carcinoma. The occurrence of pulmonary squamous cell carcinoma is rare after the chemotherapy of malignant lymphoma.

Aged↗
PubMed1992

[Clinical and microbiological study of factors determining effective scaling and root planing].

The aim of the present study was to monitor longitudinally the clinical and microbiological parameters after root debridement in order to determine the factors affecting successful and unsuccessful results. Nine patients with moderate and severe periodontitis participated. Four sites of single root with over 5-mm periodontal pockets in each quadrant were selected. The oral hygiene was controlled in all patients, then root debridement was performed without anesthesia at the three sites of the quadrants every two weeks during eight weeks. The clinical parameters consisted of plaque index, gingival index, probing depth, clinical attachment level, bleeding on probing, tooth mobility and the value of gingival crevicular fluid (GCF). The microbiological parameters such as percentages of cocci, motile rods, non-motile rods and spirochetes and the number of microorganisms were examined and the percentages of black pigmented Bacteroides (BPB) and Actinobacillus actinomycetemcomitans as well as the number of anaerobic colonies were counted. The results demonstrated that a reduction in the probing depth was observed in all sites except four. The successful sites clinically showed a decrease of the probing depth and GCF value and, microbiologically, reduced percentages of the spirochetes and BPB. The results indicated that the decrease of the probing depth and GCF under 50 Periotoron units in coincidence with the bacterial reduction can be used to determine the successful response of root debridement.

Adult↗