Biomedical subjects

T Enomoto

Publications and source records attributed to T Enomoto.

At least 181 records · Page 10Linked to original sources

PubMed1995

Characterization of DNA synthesis and DNA-dependent ATPase activity at a restrictive temperature in temperature-sensitive tsFT848 cells with thermolabile DNA helicase B.

A temperature-sensitive mutant defective in DNA replication, tsFT848, was isolated from the mouse mammary carcinoma cell line FM3A. In mutant cells, the DNA-dependent ATPase activity of DNA helicase B, which is a major DNA-dependent ATPase in wild-type cells, decreased at the nonpermissive temperature of 39 degrees C. DNA synthesis in tsFT848 cells at the nonpermissive temperature was analyzed in detail. DNA synthesis measured by incorporation of [3H]thymidine decreased to about 50% and less than 10% of the initial level at 8 and 12 h, respectively. The decrease in the level of thymidine incorporation correlated with a decrease in the number of silver grains in individual nuclei but not with the number of cells with labeled nuclei. DNA fiber autoradiography revealed that the DNA chain elongation rate did not decrease even after an incubation for 10 h at 39 degrees C, suggesting that initiation of DNA replication at the origin of replicons is impaired in the mutant cells. The decrease in DNA-synthesizing ability coincided with a decrease in the level of the DNA-dependent ATPase activity of DNA helicase B. Partially purified DNA helicase B from tsFT848 cells was more heat sensitive than that from wild-type cells. Inactivation of DNA-dependent ATPase activity of DNA helicase B from mutant cells was considerably reduced by adding DNA to the medium used for preincubation, indicating that the DNA helicase of mutant cells is stabilized by binding to DNA.

Animals↗

PubMed1995

Intrasyringal hemorrhage of the cervical cord associated with Chiari type I malformation--case report.

A 34-year-old male presented with intrasyringal hemorrhage associated with Chiari type I malformation manifesting as a history of repetitive severe pain around his neck and back and progressive sensory disturbance. Magnetic resonance imaging clearly demonstrated syringomyelia at the cervical region associated with Chiari type I malformation and hemorrhage in the syrinx which was strongly suggestive of bleeding into pre-existing syringomyelia or Gowers' syringal hemorrhage. Irrigation of the syrinx and syringosubarachnoid shunting were performed, but rebleeding occurred causing shunt malfunction. Shunt revision was performed, but a new cavity developed above the original syrinx. Foramen magnum decompression resulted in successful reduction of the new syrinx and subsequent neurological improvement. Simultaneous foramen magnum decompression and syrinx irrigation may be a better approach to treat this disease.

Adult↗

PubMed1995

Cerebral gumma mimicking glioblastoma on magnetic resonance images--case report.

A 39-year-old female presented with a syphilitic cerebral gumma mimicking small glioblastoma multiforme manifesting as visual impairment. Magnetic resonance imaging showed a low signal intensity area on T1-weighted images and marked small ring-like enhancement less than 1 cm in diameter following the administration of gadolinium. The symptoms and radiological abnormalities improved several weeks after penicillin therapy. The small ring-like enhancement was probably caused by inflammation associated with treponemal infection. A mass with a small ring-like enhancement less than 1 cm in diameter is a useful finding indicating an inflammatory lesion rather than a glial tumor.

Adult↗

PubMed1995

Epidural hematoma associated with cephalohematoma in a neonate--case report.

A female neonate presented with cephalohematoma over the temporoparietal region on the right side. Computed tomography (CT) revealed the presence of an underlying epidural hematoma (EDH) and associated skull fracture with communication between the hematomas. Aspiration of the cephalohematoma was followed by reduction in the size of the EDH. CT revealed cure without the need for an operative procedure. Aspiration is indicated for neonatal EDH with mild symptoms and liquefied cephalohematoma.

Brain↗

PubMed1995

[Giant cell interstitial pneumonia in a metal grinder with an abnormally high level of serum CA19-9].

Interstitial pneumonia and recurrent pneumothorax developed in a 48-year-old man who had worked as a metal grinder. He died of respiratory failure despite having received antibiotics and steroids, and despite having undergone pleural sclerosis therapy. Giant cell interstitial pneumonia was diagnosed; innumerable bizarre giant cells engulfing black granules were found within the alveoli. The results of high-energy dispersion X-ray microanalysis indicated that the patient had hard metal pneumoconiosis associated with tungsten in the black granules. When he was admitted to the hospital, his serum CA19-9 and SLEX concentrations were abnormally high (2600 and 200 ng/ml, respectively). Immunohistochemical analysis of lung tissue was done with anti-CA19-9 and SLEX antibodies. CA19-9 staining revealed strong bronchialization and squamous metaplasia in contrast to type II hyperplasia. SLEX staining showed strong type II hyperplasia. Further investigations will be needed to determine the mechanism of elevated tumor-associated carbohydrate antigens in serum.

Biomarkers, Tumor↗

PubMed1995

[Examination on aspirin-induced asthma and hypersensitivity to steroids--a questionnaire to 850 asthma on hypersensitivity to non-steroidal anti-inflammatory drugs and hypersensitivity to steroids].

We surveyed 850 patients with bronchial asthma and investigated such clinical features as the frequency of aspirin-induced asthma and hypersensitivity to steroids in the 457 available answers. We divided them into two groups, one was ASN: the asthmatics who had history of hypersensitivity to non-steroidal anti-inflammatory drugs, another was non-ASN: the asthmatics who had no history of hypersensitivity to non-steroidal anti-inflammatory drugs, and compared the two groups. The survey showed that the frequency of ASN was 12.0%. Its frequency rose with the severity of asthma to a level of 29.0% in severe cases. In ASN it was more frequent rates of female, infectious type, severe cases, and ASN had more frequent histories of oral use of steroids, use of ambulance, treatment in emergency rooms, and hospitalization than non-ASN. The serum IgE level was lower in ASN. The patients were 6 in ASN, none in non-ASN who had histories of hypersensitivity to steroids. They were 1.3% in all patients. 5 of 6 had past asthma attack progressived severely by rapid injection of succinate ester steroids and 2 of 6 had past by rapid injection of phosphoric acid ester steroids. In conclusion it was considered that we had to avoid rapid injection of steroids to aspirin-induced asthma and severe cases who were doubtful of aspirin-induced asthma in case of treatment of asthma attack.

Adult↗

PubMed1994

Identification of the nature of modification that causes the shift of DNA topoisomerase II beta to apparent higher molecular weight forms in the M phase.

Human cell lines express two genetically distinct isoforms of DNA topoisomerase (topo II) II: topo II alpha (p170) and topo II beta (p180). We detected a higher molecular weight form with an apparent molecular mass of about 190 kDa in M phase-arrested HeLa cells (Kimura, K., Saijo, M., Ui, M., and Enomoto, T. (1994) J. Biol. Chem. 269, 1173-1176). In this study we confirmed, using anti-topo II alpha and topo II beta monoclonal antibodies, that this higher molecular weight form is topo II beta and consists of doublet bands around 190 kDa. We confirmed that the doublet bands constituted an M phase-specific phenomenon and were not an artifact of the procedure used to accumulate mitotic cells. Digesting the immunoprecipitated materials from mitotic cell extracts with alkaline phosphatase resulted in the disappearance of the doublet bands and the appearance of the 180-kDa band with the concomitant disappearance of 32P label in the region of the doublet bands. Neither heat-inactivated alkaline phosphatase nor phosphodiesterase affected the doublet bands and the 32P label. Topo II beta in interphase cells was also phosphorylated, but the shift in apparent molecular weight was very slight after alkaline phosphatase digestion. Analysis of the labeled phosphoamino acids present in topo II beta from M phase and logarithmically growing cells indicated that phosphorylation occurred mainly on serine and fairly on threonine residues in both topo II beta isoforms. These results indicated that topo II beta is phosphorylated at specific sites in M phase, resulting in the formation of the doublet bands.

Amino Acid Sequence↗

PubMed1994

A frequent alteration of p53 gene in carcinoma in adenoma of colon.

In general, colorectal carcinoma is thought to originate mainly from adenoma, and this pathway is called the adenoma-carcinoma sequence. Carcinoma in adenoma is an appropriate model for analysis of this mechanism, because adenoma and carcinoma tissues coexist in the same polyp and the carcinoma is thought to have originated from the surrounding adenoma. Expression of the p53 protein was analyzed in 36 cases of carcinoma in adenoma in the colon by immunohistochemistry using an anti-human p53 monoclonal antibody (PAb1801). Alterations of the p53 gene were analyzed by the polymerase chain reaction for microanalysis of normal mucosa, adenoma, and carcinoma from histological slides. Mutations were assessed by the polymerase chain reaction-single strand conformation polymorphism analysis and identified by DNA sequencing in some cases. Loss of heterozygosity was studied by polymerase chain reaction-restriction fragment length polymorphism analysis. Positive staining for p53 was detected in three (8%) of 37 adenomas and 20 (53%) of 38 focal carcinomas. One (7%) of 15 adenomas with mild dysplasia, three (14%) of 22 adenomas with moderate dysplasia, and 16 (42%) of 38 focal carcinomas had a mutation in exon 5 through exon 8 of the p53 gene. As for allelic loss in the p53 gene locus, only one adenoma with moderate dysplasia had loss of heterozygosity, whereas six (40%) of 15 focal carcinomas had loss of heterozygosity. Of those tumors (3 of 37 adenomas and 20 of 38 focal carcinomas) that reacted with PAb1801, 78% (18 of 23) showed genetic alterations. Among 52 tumors which showed negative staining, five tumors had a p53 mutation and four of them were nonsense mutations. Putting all of these results together, 71% (24 of 34) of the cases underwent p53 gene and protein alterations during the conversion from adenoma to focal carcinoma. These data clearly indicate that genetic alterations of p53 are involved mainly in the malignant transformation from adenoma to focal carcinoma in colon carcinogenesis. In addition, some cases show heterogeneity of the p53 gene in carcinoma in adenoma of the colon. There may be other pathways than p53 responsible for malignant change in the colon.

Adenocarcinoma↗

PubMed1994

Vascular endothelial growth factor induces the disorganization of actin stress fibers accompanied by protein tyrosine phosphorylation and morphological change in Balb/C3T3 cells.

The effects of vascular endothelial growth factor (VEGF) on cytoskeletal actin networks, cell morphology and tyrosine phosphorylation of cellular proteins were studied in Balb/c3T3 A31-1-1 cells. VEGF induced the disorganization of actin stress fibers accompanied by drastic morphological rounding. A binding assay of [125I]VEGF demonstrated high and low affinity receptors for VEGF in the cells. Moreover, VEGF induced tyrosine phosphorylation of at least five cellular proteins in a dose and a time dependent manner. A tyrosine kinase inhibitor, genistein, inhibited the VEGF-induced morphological rounding. These results indicate that VEGF exerts the alteration of cytoskeletal organization resulting in morphological changes through inducing receptor-mediated tyrosine phosphorylation of cellular proteins.

3T3 Cells↗

PubMed1994

Clinicopathological characteristics of p53 overexpression in endometrial cancers.

Using immunohistochemical methods, we analyzed the association between nuclear p53 overexpression and various clinicopathological parameters in patients with endometrial cancers. Formalin-fixed and paraffin-embedded tissue sections from 139 cases of endometrial cancer (endometrioid type, 126; serous papillary type, 12; and clear-cell type, 1) were stained with anti-p53 monoclonal antibody (MAb) DO7. Overexpression of p53 was associated with high malignant potential, including extensive muscular invasion, advanced surgical stage, high histological grade, serous papillary type and a personal history of cancer. Lymph-node metastasis was also related to p53 overexpression with marginal significance. Survival curves determined by the Kaplan-Meier method and univariate analysis showed p53 overexpression to be associated with a poor outcome in endometrial cancer patients. However, multivariate analysis using the stepwise Cox proportional-hazard model showed that whereas lymph-node metastasis, a personal history of cancer and muscular invasion were related to poor survival rates, p53 overexpression was not. Consequently, p53 overexpression itself does not appear to be an independent prognostic factor in endometrial cancer, although a still larger sample of patient material would be required to assess this issue definitively.

Adult↗

PubMed1994

Coexpression of the c-kit receptor and the stem cell factor in gynecological tumors.

The protooncogene c-kit encodes a transmembrane receptor-type tyrosine kinase which belongs to the beta-PDGER/CSF-1 receptor tyrosine kinase family. The interaction between c-kit receptor and its corresponding ligand, stem cell factor (SCF), has been suggested to be involved in embryogenesis as well as carcinogenesis via the autocrine/paracrine system. In the present study, cancer cell lines and normal/benign/malignant tissues of the human female genital tract were examined for the expression of both c-kit and SCF by Northern blot and immunohistochemical analyses. Two of 16 cell lines showed mRNA expression of both c-kit and SCF, while 2 and 12 cell lines expressed c-kit and SCF, respectively. In tissues, several cases of malignant tumors, including three cervical cancers, one ovarian cancer, and one ovarian immature teratoma, expressed mRNA of both c-kit and SCF. In normal tissues, squamous epithelium expressed SCF immunohistochemically, while c-kit protein was detected only in melanocytes. Some tissues of malignant tumors, one squamous cell carcinoma of the cervix, two small cell carcinomas of the cervix, two serous adenocarcinomas of the ovary, and two immature teratomas of the ovary, expressed both c-kit and SCF proteins immunohistochemically. It is also notable that c-kit protein was expressed only in malignant germ cells of dysgerminomas, while SCF was expressed in the connective tissues surrounding germ cells. The present study suggests that the c-kit/SCF system may play an important role in the carcinogenesis of the female genital tract.

Endometrial Neoplasms↗

PubMed1994

Purification and cloning of a nucleotide excision repair complex involving the xeroderma pigmentosum group C protein and a human homologue of yeast RAD23.

Complementation group C of xeroderma pigmentosum (XP) represents one of the most common forms of this cancer-prone DNA repair syndrome. The primary defect is located in the subpathway of the nucleotide excision repair system, dealing with the removal of lesions from the non-transcribing sequences ('genome-overall' repair). Here we report the purification to homogeneity and subsequent cDNA cloning of a repair complex by in vitro complementation of the XP-C defect in a cell-free repair system containing UV-damaged SV40 minichromosomes. The complex has a high affinity for ssDNA and consists of two tightly associated proteins of 125 and 58 kDa. The 125 kDa subunit is an N-terminally extended version of previously reported XPCC gene product which is thought to represent the human homologue of the Saccharomyces cerevisiae repair gene RAD4. The 58 kDa species turned out to be a human homologue of yeast RAD23. Unexpectedly, a second human counterpart of RAD23 was identified. All RAD23 derivatives share a ubiquitin-like N-terminus. The nature of the XP-C defect implies that the complex exerts a unique function in the genome-overall repair pathway which is important for prevention of skin cancer.

Amino Acid Sequence↗

PubMed1994

Growth state- and cell cycle-dependent fluctuation in the expression of two forms of DNA topoisomerase II and possible specific modification of the higher molecular weight form in the M phase.

The fluctuations in the expression of two forms of DNA topoisomerase II, p170 and p180, were examined by immunoblotting during the transition of the growth state and the cell cycle in Swiss 3T3 cells. The level of p170 expression was higher during the exponentially growing phase than in the stationary phase, and the level of p180 did not appear to change when the cells changed the growth state. When quiescent cells were stimulated with serum, the p170 level began to increase at 12 h and reached a maximal level at 24-28 h, corresponding to the G2 phase. In contrast, the level of p180 was almost constant during the cell cycle, and the p180 band became obscure when the number of mitotic cells increased. Immunoblotting of the samples prepared from metaphase-synchronized HeLa cells did not have a p180 band, but did exhibit a band with a higher molecular weight. This band increased and p180 decreased in parallel with the increase in the number of mitotic cells. When the cells exited from the M phase, p180 reappeared and the higher molecular weight band disappeared.

3T3 Cells↗

PubMed1994

Immunohistochemical analysis of p53 in gynecologic tumors.

Immunohistochemical staining for the p53 protein was performed in microwave-fixed, paraffin-embedded sections of normal, premalignant and malignant tissues of the female genital tract using a monoclonal antibody, PAb 1801. No staining was detected in normal and premalignant tissues, whereas nuclear staining of cancer cells was observed in 12 (22%) of 55 cervical squamous cell carcinomas, 4 (25%) of 16 cervical adenocarcinomas, 37 (42%) of 88 endometrial carcinomas, 23 (38%) of 60 ovarian adenocarcinomas, and 6 (100%) of 6 squamous cell carcinomas arising in dermoid cysts. Of interest, 1 of 7 endometrial cancers with concomitant atypical hyperplasia showed weak nuclear staining in a few atypical hyperplastic glands in addition to the cancerous lesions. Although staining was associated with cancers having a high histologic grade and serous papillary adenocarcinomas of the endometrium, it did not correlate with invasion, metastasis, or clinical stage. Comparison of the staining patterns with molecular analysis of mutations in the p53 gene showed the expected correlation of nuclear staining with missense mutations but not with nonsense mutations, which consistuted one third of all mutations found in this series. In addition, cytoplasmic staining did not predict mutation.

Cervix Uteri↗

PubMed1994

Deficiency of tyrosine phosphorylation in a Balb/c 3T3 cell variant hypersensitive to phorbol ester-induced cell transformation.

To identify the cellular factors which are involved in tumor promotion, we isolated and cloned a Balb/c 3T3 variant (designated Balb/c 3T3 TR4) showing hypersensitivity to phorbol ester-induced neoplastic cell transformation; variant cells were 50- to 100-fold more sensitive to phorbol ester induced cell transformation than the parent Balb/c 3T3 A31-1-1 cells. By using an anti-phosphotyrosine antibody, the variant TR4 cells were found to be deficient in the phorbol ester-induced tyrosine-phosphorylation of a cellular protein with a mol. wt of 66 kDa. The phosphorylation of this protein was rapidly induced by phorbol ester tumor promoters on tyrosine residues in the parent 1-1 cells. Biological and biochemical analyses using fusion cells revealed a good correlation between the deficiency in the tyrosine phosphorylation of this protein and their sensitivity to phorbol ester-induced cell transformation, suggesting that the deficiency in phorbol ester-induced tyrosine phosphorylation of the 66 kDa protein may be involved in the determination of the sensitivity of TR4 variant cells to phorbol ester-mediated neoplastic cell transformation. In addition, our observations suggest the possible involvement of the modulation of tyrosine phosphorylation of cellular proteins in the process of phorbol ester-mediated tumor promotion.

3T3 Cells↗

PubMed1994

Purification of two DNA-dependent adenosinetriphosphatases having DNA helicase activity from HeLa cells and comparison of the properties of the two enzymes.

DNA-dependent ATPase activities in crude extracts prepared from HeLa cells were separated into five peaks designated Q1 to Q5 by FPLC Mono Q column chromatography. In our previous study, we observed that crude extracts prepared from xeroderma pigmentosum complementation group C (XP-C) cells contained no DNA-dependent ATPase activity at the peak position of Q1 and exhibited a broader peak with higher activity than normal Q2 at the peak position of Q2 [Yanagisawa, J., Seki, M., Ui, M., & Enomoto, T. (1992) J. Biol. Chem. 267, 3585-3588]. We have purified two DNA-dependent ATPases Q1 and Q2 from HeLa cells and characterized their properties in order to obtain a means to discriminate ATPase Q1 from Q2 in XP-C cells. The apparent molecular masses of Q1 and Q2 on SDS-polyacrylamide gel electrophoresis were 73 and 100 kDa, respectively. The two enzymes required a divalent cation for activity. DNA-dependent ATPase Q1 hydrolyzed ATP and dATP and Q2 hydrolyzed ATP preferentially among the nucleotides tested. Both enzymes preferred single-stranded DNA as a cofactor. The DNA-dependent ATPase activity of Q2 was inhibited by 90% in the presence of 200 mM NaCl, whereas that of Q1 was not affected by NaCl at concentrations up to 200 mM. Both enzymes had DNA helicase activity, that of Q1 being more resistant to NaCl than that of Q2. The DNA helicase activity of Q2 was about 150-fold higher than that of Q1, when compared with units of ATPase activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Triphosphatases↗

PubMed1994

Analysis of clonality by amplification of short tandem repeats. Carcinomas of the female reproductive tract.

The clonal composition of cancers of the female reproductive tract was evaluated by analysis of patterns of X-chromosome inactivation. Using DNA extracted from frozen tissues or paraffin-embedded archival specimens as template, polymerase chain reaction (PCR) was performed to generate amplified DNA fragments of exon 1 of the X-linked androgen receptor gene, which contains a highly polymorphic trinucleotide repeat. Predigestion of tumor DNA with methylation-sensitive restriction endonuclease Hha I or Hpa II permitted selective PCR amplification from the methylated (uncleaved) allele. Of a total of 54 tumors analyzed, 50 cases showed heterozygosity (93%) and were therefore informative for clonal analysis. Monoclonal composition of the tumors was suggested in a total of 49 of 50 cases, including 12 adenocarcinomas of the uterine endometrium, 13 squamous cell carcinomas of the uterine cervix, 6 adenocarcinomas of the uterine endocervix, and 18 epithelial tumors of the ovary. However, polyclonal composition was observed in one mucinous carcinoma of the ovary, in which we previously showed that both GGT-->GAT and GGT-->GTT mutations are present in > 20% of total K-ras copies in the tissue. Our studies demonstrate the utility of PCR amplification of highly polymorphic repetitive sequences for analysis of patterns of X-chromosome inactivation. This approach is practical for the analysis of clonal cell composition in a high proportion of both formalin-fixed and frozen archival tissues.

Carcinoma↗

PubMed1994

A case-control study on risk factors for uterine endometrial cancer in Japan.

A case-control study of 143 Japanese women with uterine endometrial cancer and 143 individually age-matched controls was conducted to assess the risk factors for endometrial cancers in Japan. Among the characteristics studied, the following factors were significantly greater in the cases than in the controls: nulliparity (odds ratio for parity 1-3 and > or = 4 versus nullipara are 0.40 and 0.02, respectively), obesity (odds ratio: 2.73), hypertension (odds ratio: 2.4), diabetes mellitus (odds ratio: 6.30), and a personal medical history of cancer (odds ratio: 3.06). The present study showed that Japanese women have the same risk factors for endometrial cancer as those reported in Western countries. The recent increase in the incidence of endometrial cancer in Japan may be largely attributed to the decrease in parity.

Adenocarcinoma↗