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Biomedical subjects

M Tsujimoto

Publications and source records attributed to M Tsujimoto.

At least 73 records · Page 4Linked to original sources

Structural organization of the 5'-end and chromosomal assignment of human placental leucine aminopeptidase/insulin-regulated membrane aminopeptidase gene.

Placental leucine aminopeptidase (P-LAP) which is identical with cystine aminopeptidase as oxytocinase was found to be a homologue of rat insulin-regulated membrane aminopeptidase (IRAP) by cDNA cloning. In this study, we confirmed 5'-end cDNA sequence of P-LAP and isolated genomic clones containing the upstream region of human P-LAP gene. The transcription initiation sites determined by primer extension located 478 and 480 bp upstream of the initiation methionine codon, 38 bp downstream of TATA box-like motif. The 5'-flanking region of human P-LAP gene contained DNA-binding motifs for several ubiquitous transcription factors such as SP1 and AP2. Chromosomal localization by fluorescence in situ hybridization showed that the gene was assigned to 5q14.2-q15 of the human chromosome. This study establishes the genetic basis for P-LAP gene research, thereby leading to better understanding of the molecular mechanism underlying the P-LAP gene.

Aminopeptidases↗

Expression and prognostic roles of the G1-S modulators in hepatocellular carcinoma: p27 independently predicts the recurrence.

Expression of cell-cycle modulators at the G1-S boundary, retinoblastoma gene product (pRb), p21, p16, p27, p53, cyclin D1, and cyclin E was investigated with 104 hepatocellular carcinomas (HCC), as well as 90 of their adjacent noncancerous lesions and 9 normal liver control specimens. The labeling indices (LI) of pRb, p21, p16, and p27 were higher in HCC lesions than in the adjacent noncancerous lesions and normal controls. Especially, p27 LI in noncancerous lesions was significantly higher than that in normal livers (P =.011). Aberrant p53 expression and cyclin D1 and E overexpression were observed exclusively in HCC lesions. pRb was positive in 85.6% of the HCC cases and was not related to any clinicopathological parameters. The p21 LI was generally low (average, 5.5 +/- 9.8). Although a negative regulator, p21 LI was higher in cases with intrahepatic metastasis (P =.0359). The p16 LI was significantly decreased (P =.0121) in cases with advanced stage. p27 LI was significantly decreased in cases with portal invasion (P =.0409), poor differentiation (P <.0001), larger size (P =.0421), and intrahepatic metastasis (P =.0878, borderline significance). On the other hand, aberrant p53 expression showed positive relationships with poor differentiation (P =.0004) and Ki-67 LI (P =. 0047). Cyclin D1 overexpression was found in 32.6% of the cases and occurred more frequently in those with high Ki-67 LI (P =.0032), pRb expression (P =.0202), poor differentiation (P =.0612, borderline significance), and intrahepatic metastasis (P =.0675, borderline significance). Cyclin E was overexpressed in 35.5% and had positive relationships with Ki-67 LI (P =.0269) and stage (P =.0125). In univariate analysis, cases with p27 LI < 50 (P =.0004), cyclin D1 overexpression (P =.0041), and cyclin E overexpression (P =.0572, borderline significance) showed poorer outcomes for disease-free survival (DFS). In multivariate analysis, p27 expression could be recognized as an independent prognostic marker for DFS. These findings suggest that in HCC: 1) p27 is active against HCC progression in early phases and, possibly, hepatocarcinogenesis as a negative regulator and can be a novel prognostic marker for DFS; and 2) cyclin D1 predominantly works for cell-cycle progression at the G1-S boundary.

Adult↗

Both cell proliferation and apoptosis significantly predict shortened disease-free survival in hepatocellular carcinoma.

In this study, we investigated the proliferating cell index by the percentage of Ki-67 expressing cells (Ki-67 LI) and the apoptotic index (AI) by the number of morphologically apoptotic cells per 1000 carcinoma cells in haematoxylin and eosin sections of 76 hepatocellular carcinomas (HCC). Both indices showed excellent correlation with each other (P < 0.0001) and were significantly higher in cases of poor differentiation, of advanced stages, with portal invasion and with intrahepatic metastasis. Furthermore, cases with higher Ki-67 LI or higher AI displayed poor outcomes for disease-free survival (P = 0.0001 and P = 0.0005) by univariate analysis. By multivariate analysis, both indices could be regarded as independent prognostic factors. These results strongly suggest that Ki-67 LI and AI have very similar clinical significance, reflecting the existence of biologically aggressive phenotypes and poor disease-free survival rate in HCC.

Aged↗

Bone morphogenetic protein-2 promotes survival and differentiation of striatal GABAergic neurons in the absence of glial cell proliferation.

We examined the potential neurotrophic effects of bone morphogenetic protein (BMP)-2 on the survival and differentiation of neurons cultured from the rat developing striatum at embryonic day 16, a period during which the mRNAs for BMP-2 and its receptor subunits (types IA, IB, and II) were detected. BMP-2 exerted potent activity to promote the survival of striatal neurons and increased the number of surviving microtubule-associated protein-2-positive cells by 2.4-fold as compared with the control cultures after 4 days in vitro. Although basic fibroblast growth factor (bFGF) also showed relatively high activity to promote the survival of striatal neurons, transforming growth factor-beta1, -beta2, and -beta3, glial cell line-derived neurotrophic factor, or brain-derived neurotrophic factor promoted their survival weakly. Striatal neurons cultured in the presence of BMP-2 or bFGF possessed extensive neurite outgrowths, the majority of which were GABA-immunoreactive. Inhibition of glial cell proliferation by 5-fluorodeoxyuridine did not affect the capacity of BMP-2 to promote the survival of striatal GABAergic neurons. In contrast, the ability of bFGF to promote the survival of striatal neurons was inhibited significantly by the treatment of cells with 5-fluorodeoxyuridine. All these results suggest that BMP-2 exerts potent neurotrophic effects on the striatal GABAergic neurons in a glial cell-independent manner.

Animals↗

Molecular cloning of adipocyte-derived leucine aminopeptidase highly related to placental leucine aminopeptidase/oxytocinase.

In the current study, we report the cloning and initial characterization of a novel human cytosolic aminopeptidase named adipocyte-derived leucine aminopeptidase (A-LAP). The sequence encodes a 941-amino acid protein with significant homology (43%) to placental leucine aminopeptidase (P-LAP)/oxytocinase. The predicted A-LAP contains the HEXXH(X)18E consensus sequence, which is characteristic of the M1 family of zinc-metallopeptidases. Although the deduced sequence contains a hydrophobic region near the N-terminus, the enzyme localized mainly in cytoplasm when expressed in COS-7 cells. Northern blot analysis revealed that A-LAP was expressed in all the tissues tested, some of which expressed at least three forms of mRNA, suggesting that the regulation of the gene expression is complex. When aminopeptidase activity of A-LAP was measured with various synthetic substrates, the enzyme revealed a preference for leucine, establishing that A-LAP is a novel leucine aminopeptidase with restricted substrate specificity. The identification of A-LAP, which reveals strong homology to P-LAP, might lead to the definition of a new subfamily of zinc-containing aminopeptidases belonging to the M1 family of metallopeptidases.

Adipocytes↗

Clinicopathological significance of poorly differentiated thyroid carcinoma.

The clinicopathological importance of a heterogeneous group of poorly differentiated thyroid carcinomas is not fully understood. Using data obtained from 303 surgically treated patients with differentiated thyroid carcinomas, the correlations between the aggressive histologic features and the clinicopathological findings, postoperative recurrences, and prognosis were retrospectively examined. In 201 cases, the carcinomas were well differentiated. The remaining 102 cases of poorly differentiated carcinomas were divided into two groups: focal-poorly differentiated (<10%) and diffuse-poorly differentiated (> or = 10%) carcinomas according to the extent of the poorly differentiated component. These poorly differentiated carcinomas were associated with high age (focal-poorly differentiated and diffuse-poorly differentiated versus well differentiated: 55 years and 59 versus 49; p < 0.0001), frequent presence of lymph node metastases (70% and 66% versus 48%; p = 0.0099) and distant metastases at diagnosis (11% and 11% versus 2%; p = 0.0098), and extrathyroidal invasion (53% and 53% versus 21%; p < 0.0001). There was independent correlation with age and the presence of extrathyroidal invasion. Cases of diffuse-poorly differentiated carcinomas showed frequent relapse (diffuse-poorly differentiated versus focal-poorly differentiated and well differentiated: 45% versus 30% and 24%; p = 0.0062) and poor prognoses (mean survival period = 9.15 versus 19.03 and 20.87 years; p < 0.0001) compared with the well and focal-poorly differentiated carcinomas. These data suggest that diffuse-poorly differentiated carcinoma is an important clinicopathological entity.

Adenocarcinoma, Follicular↗

Sperm chromatin decondensation by template activating factor I through direct interaction with basic proteins.

Template activating factor I (TAF-I) was originally identified as a host factor required for DNA replication and transcription of adenovirus genome complexed with viral basic proteins. Purified TAF-I was shown to bind to core histones and stimulate transcription from nucleosomal templates. Human TAF-I consists of two acidic proteins, TAF-Ialpha and TAF-Ibeta, which differ from each other only in their amino-terminal regions. Here, we report that TAF-I decondenses demembraned Xenopus sperm chromatin. Human TAF-Ibeta has a chromatin decondensation activity comparable to that of NAP-I, another histone binding protein, whereas TAF-Ialpha has only a weak activity. Analysis of molecular mechanisms underlying the chromatin decondensation by TAF-I revealed that TAF-I interacts directly with sperm basic proteins. Deletion of the TAF-I carboxyl-terminal acidic region abolishes the decondensation activity. Interestingly, the acidic region itself is not sufficient for decondensation, since an amino acid substitution mutant in the dimerization domain of TAF-I which has the intact acidic region does not support chromatin decondensation. We detected the beta form of TAF-I in Xenopus oocytes and eggs by immunoblotting, and the cloning of its cDNA led us to conclude that Xenopus TAF-Ibeta also decondenses sperm chromatin. These results suggest that TAF-I plays a role in remodeling higher-order chromatin structure as well as nucleosomal structure through direct interaction with chromatin basic proteins.

Amino Acid Sequence↗

Changes in the incidence and prevalence of rheumatoid arthritis in Kamitonda, Wakayama, Japan, 1965-1996.

OBJECTIVE: To evaluate secular trends in the incidence and prevalence of rheumatoid arthritis (RA) in Japan. METHODS: The incidence and prevalence of RA were determined in a longitudinal population based study in the Kamitonda district, Wakayama, Japan, from 1965 to 1996. RESULTS: In the study area consisting of about 3000 inhabitants, 16 incident cases, satisfying definite RA by the Rome criteria were detected during the study period. The age and sex adjusted incidence in both men and women combined and the age adjusted incidence in women significantly decreased (p<0.025 and p<0. 01, respectively). The age and sex adjusted prevalence in all inhabitants tended to decrease (p<0.1), and the age adjusted prevalence in women significantly declined (p<0.025). In men, however, neither incidence nor prevalence showed significant change. CONCLUSIONS: The decline of incidence and prevalence of female RA may be reducible to some environmental changes preferentially occurring more obviously in Japanese women than in men. Because the use of oral contraceptives has been extremely low in Japan, the decline should be explained by other factors.

Adolescent↗

[Intravesical bacillus Calmette-Guerin instillation therapy for carcinoma in situ of the urinary bladder and prediction of effects by urinary cytologic examination].

PURPOSE: We investigated the effects of intravesical BCG instillations for carcinoma in situ (CIS) of the urinary bladder. And we have retrospectively analyzed the prediction of effects by fresh urinary cytologic examinations before instillation. MATERIAL AND METHODS: 33 patients were treated for bladder CIS (1991-1997) with a median follow-up of 30 months (range from 9 to 90 months). The patients (27 males and 6 females) ranged in age from 46 to 91 (average 71 years) and received 6 to 12 weekly BCG Tokyo 172 strain 80 mg instillations. They were divided into 3 groups based on tumor history: primary (9), secondary (15), concurrent (9). The prediction of effects were analyzed by scoring fresh urinary cytologic examinations before instillation. RESULTS: 22 cases (67%) were responded and they have remained free of disease for follow-up period. The statistic evaluation proved to show the significance between the effects of treatment and the sum of scoring (cellular appearance and existence of large nuclear cells). CONCLUSION: We confirmed the effects of this treatment. The prediction of effect of this treatment seemed to be indicative by fresh urinary cytologic examinations before instillation, especially cellular appearance and existence of large nuclear cells.

Adjuvants, Immunologic↗

[Mediastinoscopic resection combined with a sternum lift technique in a case of thymic cyst].

We report on a case of thymic cyst which was successfully treated with mediastinoscopic resection combined with a sternum lift technique. A 62-year-old man was admitted to our hospital with a thymic cyst, which was causing chest discomfort and was increasing in size. The tumor was located above the pulmonary artery in the anterior mediastinum. He underwent mediastinoscopic resection while lifting the inferior portion of the sternum with a Laparolift. The cyst was resected sharply and bluntly with the Harmonic Scalpel without rupture. The patient was discharged on the 6th postoperative day in a good condition. Mediastinoscopic resection of a thymic cyst through a xiphoid approach is a useful surgical approach because of the absence of postoperative pain and because it allows early discharge from the hospital.

Endoscopy↗

[Brain surface clear cell ependymoma: case report].

We report a case of brain surface clear cell ependymoma. A 13-year-old boy presented with complaints of right hypesthesia. Computed tomography and magnetic resonance image showed a left fronto-parietal cystic, calcified mass lesion. He underwent total resection of the tumor including cyst wall. The tumor located on the surface of the parietal lobe was sharply demarcated from the surrounding brain tissue and there was no continuity with the ventricular wall. Histological examination of the surgical specimens showed oligodendroglioma-like cells that had round unclei, clear cytoplasm which formed perivascular pseudorosettes, and immunoreactivity for glial fibrillary acidic protein (GFAP). Electromicroscopically, microvilli were seen. The findings were compatible with clear cell ependymoma. The cyst wall was lined with a layer of single cuboidal cells and, immunohistochemically, had no basal membrane. The inner surface of the cyst was positive for EMA, and the cuboidal cells were positive for GFAP. We discuss possible mechanisms for tumor growth in our case and the histogenesis of its cyst.

Adolescent↗

[A case report of gastric carcinoma with complete remission of paraaortic lymph node metastasis by 5'-DFUR and MMC administration after resection of primary tumor].

A 53-year-old man was referred to our hospital with Borrmann type 2 advanced gastric cancer with a Virchow's node metastasis. A CT scan revealed a paraaortic lymph node metastasis. Because the tumor was diagnosed as being a poor candidate for curative resection, only a total gastrectomy was done. After surgery, administration of 5'-DFUR and MMC was begun. As a result, the paraaortic lymph node metastasis disappeared and the Virchow's node metastasis was reduced. The patient is well with no sign of recurrence 20 months after the operation.

Antineoplastic Combined Chemotherapy Protocols↗

Prognostic Factors in Breast Cancer and their Limitations.

Evaluation of the prognosis of patients with breast cancer is criticai in determining post-surgical adjuvant therapy because of great heterogeneity in response to the therapy, At present, the decision-making for adjuvant therapy largely depends on histologic nodal status, but a significant number of patients without nodal involvement undergo relapse. Although great efforts have been made for more accurate and potent factors, significant indicators have not yet been found. One of the promising candidates, however, is histologic angiogenesis in tumors, which we and others have indicated as an independent prognostic factor in node-negative subset by the multivariate analysis. Here we will evaluate several prognostic factors in clinical use.

Journal Article↗

Expression of CD44 variant 6 and lymphatic invasion: importance to lymph node metastasis in gastric cancer.

Lymph node metastasis is a critical prognostic factor for gastric cancer. In the present investigation we examined clinicopathologic factors influencing the metastatic processes to the lymph mode and their prognostic importance. A randomly selected group of 98 patients with adenocarcinomas of the stomach who underwent gastrectomy plus systematic lymph node dissection at Osaka Police Hospital from 1991 to 1996 were analyzed. Altogether 37 (38%) cancers were positive for CD44 variant 6 (v6) staining, 31 (32%) were intermediately stained, and 30 (30%) were negative. CD44-v6 expression correlated well with lymph node metastasis. Expression of CD44-v6 and lymphatic invasion were independent risk factors for metastatic lymph nodes. Among the patients with CD44-v6-positive and lymphatic invasion-positive cancers, 88% had lymph node metastasis, whereas only 13% of patients negative for both factors had lymph node metastasis. Although CD44-v6 expression and lymphatic invasion have been reported to be risk factors for recurrence and a poor prognosis, in this investigation these factors were found not to be significant for hematogenous and lymphatic recurrences or overall survival rates. Thus expression of CD44-v6 and lymphatic invasion may regulate lymph node metastases from gastric cancer.

Adenocarcinoma↗

Significance of biologic aggressiveness and proliferating activity in papillary thyroid carcinoma.

Papillary thyroid carcinoma is a frequent thyroid cancer. Many factors have been reported to be of prognostic importance, but the significance of biologic factors suggesting aggressiveness and proliferating activity has not been sufficiently documented. Conventional prognostic factors such as age, extrathyroidal invasion, lymph node and distant metastasis, and biologic factors including histologic differentiation, DNA ploidy, S-phase and G2M-phase fractions, and expression of CD44 variant 6 (CD44-v6) obtained from 131 patients who underwent surgery for papillary thyroid carcinoma at Osaka Police Hospital were analyzed retrospectively. Age was closely related to extrathyroidal invasion, G2M-phase fraction, and CD44-v6 expression. Extrathyroidal invasion was independently related to age, gender, and lymph node metastasis. The grade of lymph node metastasis was related to extrathyroidal invasion, gender, distant metastasis, and CD44-v6 expression. Distant metastasis was associated with aneuploid tumors. Cause-specific survival was independently related to biologic factors including extrathyroidal invasion, distant metastasis, DNA ploidy and S-phase fraction. These results suggest that biologic factors indicating aggressiveness and proliferating activity are important for papillary thyroid carcinoma.

Aged↗

Independent prognostic factors in breast cancer patients.

BACKGROUND: Recently tumor microvessel density has been shown to be a powerful prognostic tool in breast cancer. We attempted to assess its significance as a prognostic factor. METHODS: We analyzed the medical records of 100 patients using univariate and multivariate analyses of nine factors as follows; age, tumor size, nodal status, estrogen receptor, C-erbB2, p53, microvessel density, DNA ploidy pattern, and S-phase fraction. RESULTS: Nodal status and microvessel density were independent prognostic indicators for both survival and relapse-free survival. Microvessel density was independent in the node-negative subgroup for survival, but not independent in the node-positive subgroup, while it was independent in both the node-negative and node-positive subgroups for relapse-free survival. Short-term survival rates in the high and low vessel density subgroups were almost the same, and all patients with early death were node-positive. CONCLUSION: Microvessel density was an important prognostic factor especially in node-negative patients and more significant in long-term survival.

Age Factors↗