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M Nishi

Publications and source records attributed to M Nishi.

At least 235 records · Page 13Linked to original sources
PubMed1991

Biosynthesis of islet amyloid polypeptide. Elevated expression in mouse beta TC3 cells.

Islet amyloid polypeptide (IAPP) messenger RNA levels, biosynthesis, processing, and secretion were studied in cultured mouse beta TC3 insulinoma cells. Northern blot analysis revealed that the size of IAPP mRNA (0.9 kb) in beta TC3 cells was the same as that in normal mouse islets; IAPP mRNA was approximately 60% of the level of insulin mRNA in beta TC3 cells. However, the ratio of synthesis of insulin to IAPP was approximately 6:1, suggesting that IAPP mRNA is not translated efficiently in these cells. Metabolic labeling of beta TC3 cells with [3H]leucine revealed the synthesis of both a precursor form of IAPP (pro-IAPP) of apparent Mr 7400 and a mature form (IAPP) of apparent Mr 3900. In pulse-chase experiments, pro-IAPP could be shown to be processed to IAPP in a manner similar to proinsulin. The t1/2 for conversion of pro-IAPP to IAPP was about 25 min, faster than the t1/2 for proinsulin to insulin of 70 min. A significant proportion of newly synthesized IAPP and insulin precursors were secreted via a constitutive pathway from beta TC3 cells. Possible effects of dexamethasone and forskolin on IAPP mRNA levels and biosynthesis were examined but no effects were observed. In conclusion, the IAPP gene is strongly expressed in beta TC3 cells leading to the biosynthesis, proteolytic processing, and secretion of IAPP, a putative islet hormone.

Amyloid↗
PubMed1991

Regional chromosomal assignment of carcinoembryonic antigen gene (CEA) to chromosome 19 at band q13.2.

Carcinoembryonic antigen (CEA), a glycoprotein, is one of the most widely used human tumor markers. It is a member of a gene family comprising about 10 closely related genes and might be found throughout mammalians. Recently, two parts of a genomic DNA for CEA were isolated and sequenced. Using these genomic DNA fragments as probes we assigned the human CEA gene to chromosome 19 at the band q13.2 by in situ hybridization.

Carcinoembryonic Antigen↗
PubMed1991

Sequences of islet amyloid polypeptide precursors of an Old World monkey, the pig-tailed macaque (Macaca nemestrina), and the dog (Canis familiaris).

The 37-amino acid islet amyloid polypeptide represents the major protein component present in islet amyloid deposits. Although the presence of islet amyloid is a characteristic pathological feature of the islets of humans, monkeys and cats with Type 2 (non-insulin-dependent) diabetes mellitus, it is not found in the islets of diabetic rats, mice or dogs. To further explore the molecular basis for these species differences in amyloid deposition we have used a polymerase chain reaction based method to clone cDNAs encoding the monkey (Macaca nemestrina) and dog (Canis familiaris) islet amyloid polypeptide precursors. The predicted amino acid sequence of the monkey precursor is 96% identical to that of the human protein; differences include one replacement in the signal peptide and three in the islet amyloid polypeptide domain. The sequence of the dog precursor is most closely related to that of the cat protein (85% identity); the sequences of dog and cat islet amyloid polypeptide differ only at two positions and are identical in the region of amino acids 20-29, the region thought to be primarily responsible for amyloidogenesis. Thus, amino acid residues in addition to those at positions 20-29 may facilitate the aggregation of islet amyloid polypeptide. The presence of amyloid deposits in some dog pancreatic endocrine tumours suggests that the dog protein can be amyloidogenic, perhaps due to elevated expression of islet amyloid polypeptide by the tumours relative to normal islets.

Amino Acid Sequence↗
PubMed1991

Duct endoscopy and endoscopic biopsy in the evaluation of nipple discharge.

Microdochectomy is usually performed on patients with nipple discharge caused by intraductal proliferative lesions, such as intraductal papilloma and carcinoma. But this operation often sacrifices large amounts of normal mammary gland even when the lesion is a benign intraductal papilloma a few millimeters in diameter. We have developed duct endoscopy for the mammary duct system, and have reliably performed biopsies for intraductal proliferative lesions intraductally. From June 1989 to April 1990, we examined 22 cases by duct endoscopy, and performed endoscopic biopsy in 16 cases. The method of endoscopic biopsy is as follows. First, a bougie is inserted, without anesthesia other than Xylocaine jelly, into the orifice of the duct to enlarge it. Second, the outer cylinder and the inner needle are inserted; then the inner needle is removed, and the endoscope is inserted. After examination, the outer cylinder is moved up to the lesion to be biopsied and the endoscope is taken out. Then a sample is taken into the outer cylinder by aspiration. We diagnosed 10 cases of benign lesion and 5 cases of malignant lesion by cytological and/or histological examination. In conclusion, endoscopic biopsy, aided by duct endoscopy, is a useful and harmless diagnostic procedure in the evaluation of nipple discharge.

Biopsy↗
PubMed1991

Developmental regulation of gap junction gene expression during mouse embryonic development.

The expression of products from three different gap junction genes (alpha 1, beta 1 and beta 2) was studied in pre- and postimplantation mouse embryos, during organogenesis, during differentiation of F9 teratocarcinoma cells, and in cultured embryonic stem (ES) cells. In this analysis, the following results were obtained. 1) Pre- and postimplantation mouse embryos. The alpha 1 transcript was the earliest gap junction RNA detected (in the 4 cell stage embryo) and its abundance increased significantly throughout subsequent development. 2) Organogenesis. Evidence was obtained for developmental expression of these three different gap junction genes during early embryogenesis and throughout the late stages of organogenesis. The expression patterns for these genes may be related to differences in gap junctional communication requirements for fetal organ development versus neonatal and adult organ function, or the utilization of different genes by different cell types during organogenesis. 3) During the differentiation of F9 cells in culture, expression of these three genes was modulated. Thus, this is the first evidence for modulation of gap junction gene expression during the differentiation of a single cell type in culture. 4) In an ES cell culture line, alpha 1 was the only gap junction gene product detected. This is consistent with the findings of alpha 1 expression in the embryonic inner cell mass region and in undifferentiated teratocarcinoma cells.

Amino Acid Sequence↗
PubMed1991

The morphologic feature of mucus leakage appearing in low papillary carcinoma of the breast.

This report summarizes the clinicopathologic findings in 11 cases of low papillary carcinoma of the breast accompanied by the morphologic feature of mucus leakage into the mammary stroma. These cases were characterized by two morphologic findings. First, abundant mucus produced by the tumor cells filled the intraductal spaces where neoplastic epithelium formed very low papillary projections, ie, a feature of mucinous-producing low papillary carcinoma in situ. Second, there was expansive leakage of mucus into the mammary stroma occasionally accompanied by a few epithelial cells. All the cases showed a high level of mucus production and contained no elements of invasive ductal carcinoma or ordinary invasive mucinous carcinoma. These cases have no evidence of direct invasion of the mammary stroma by malignant cells. The average age of the 11 patients was 41 years. Foci of microcalcification were seen in some tumors (seven cases; 64%). There were no cases with lymph node metastases. All the patients underwent mastectomy with no adjuvant therapy, and they are currently alive and well.

Adenocarcinoma, Mucinous↗
PubMed1991

Anaplastic large cell lymphoma, so-called Ki-1 lymphoma: a report of a case of long course.

A 55-year-old female with a complaint of tumors on the right lower extremity was reported. The condition was diagnosed as anaplastic large cell lymphoma, so-called Ki-1 lymphoma, by its histological and immunohistochemical features. The clonal proliferation of the infiltrating cells of the skin lesions was confirmed by the analysis of T cell receptor gene rearrangement. The lesions have repeatedly occurred on the right lower extremity for more than ten years. In this report, we also discuss the prognosis of anaplastic large cell lymphoma with or without skin lesions.

Anaplasia↗
PubMed1991

Quantitative assay of epidermal growth factor receptor in human squamous cell carcinomas of the oral region by an avidin-biotin method.

A quantitative assay method for epidermal growth factor receptors (EGFRs) of human tumor tissues was established, based on enzyme-labeled avidin-biotin (LAB) interaction with anti-human EGFR monoclonal antibody 528IgG. A standard calibration curve for EGFR estimation in human tumor tissues was obtained with A431#8 cells cloned from A431 human epidermoid carcinoma cell line. The coefficient of variance for the standard curve was below 35% in the application to tumor tissues from nude mice implanted with human tumor cell lines. The minimum tissue amount required for the quantitative assay was around 0.1 g (wet weight). Using the LAB method, the correlation between the level of EGFR number and tumor malignancy was examined for 14 human squamous cell carcinomas (SCCs) from the oral region. Seven of the SCCs showed a more than two-fold higher EGFR number compared to normal gingival tissues. Three highly aggressive carcinomas with poor prognosis possessed five to ten times higher levels of EGFR number than normal tissues. The elevated EGFR level in the SCCs seems to correlate to increasing tumor size and the stage of SCCs as clinically classified according to the 1987 UICC TNM system.

Adult↗
PubMed1991

Conversion of Friend mink cell focus-forming virus to Friend spleen focus-forming virus by modification of the 3' half of the env gene.

The 3' half of the env gene of the dualtropic Friend mink cell focus-forming virus was modified by replacing the restriction enzyme fragment of the genome DNA with the corresponding fragment of the acutely leukemogenic, polycythemia-inducing strain of Friend spleen focus-forming virus (F-SFFVP) genome DNA. Replacement with the fragment of F-SFFVP env containing the 585-bp deletion, the 6-bp duplication, and the single-base insertion converted the resulting chimeric genome so that the mutant had a pathogenic activity like that of F-SFFVP. Replacement with the fragment containing only the 585-bp deletion did not result in a pathogenic virus. However, when this virus pseudotyped by Friend murine leukemia virus was passaged in newborn DBA/2 mice, we could recover weakly pathogenic viruses with a high frequency. Molecular analysis of the genome of the recovered virus revealed the presence of a single-base insertion in the same T5 stretch where the wild-type F-SFFV env has the single-base insertion. These results provided evidence that the unique genomic structures present in the 3' half of F-SFFV env are the sole determinants that distinguish the pathogenicity of F-SFFV from that of Friend mink cell focus-forming virus. The importance of the dualtropic env-specific sequence present in the 5' half of F-SFFV env for the pathogenic activity was evaluated by constructing a mutant F-SFFV genome in which this sequence was replaced by the ecotropic env sequence of Friend murine leukemia virus and by examining its pathogenicity. The results indicated that the dualtropic env-specific sequence was essential to pathogenic activity.

Animals↗
PubMed1991

Can a patient with neuroblastoma be diagnosed by a single urine sample collected randomly?

We have observed that a fairly large amount of vanillylmandelic acid and homovanillic acid in urine samples taken randomly from patients with a tumor of about 10 g was less than the cutoff values and overlapped with the respective ranges of normal infants. Consequently, with only a single random urine sample there is a risk of overlooking a patient, especially in cases where the tumor is small. However, according to theoretical calculation, several random urine samples may enable us to discriminate a patient from a normal infant and can replace the 24-hour urine accumulation for 3 days which is currently performed for final judgement in the mass screening of neuroblastoma.

Homovanillic Acid↗
PubMed1991

Islet amyloid polypeptide and insulin expression are controlled differently in primary and transformed islet cells.

The pancreatic beta-cell is a major site of islet amyloid polypeptide (IAPP) biosynthesis, and the peptide is coreleased with insulin. We have analyzed the expression of IAPP (mRNA and protein) in various cell types in normal and transformed murine islet cell cultures by Northern blot analyses and immunocytochemistry. IAPP is primarily coexpressed with insulin in the beta-cell of GH-promoted primary rat islet cell cultures. Additionally, a small population of non-beta-cells exhibited a prominent IAPP expression, and double staining experiments showed colocalization with glucagon or somatostatin in some of these cells. IAPP mRNA was confined to the beta-cell phenotype when analyzing the phenotypically stable in vivo tumor lines, MSL-G2-IN (insulinoma) and MSL-G-AN (glucagonoma), and the transgenic mouse islet cell lines, beta-Tc and alpha-Tc. However, IAPP and insulin expression were completely uncoupled in unstable heterogeneous clones such as NHI-6F. This clone is composed of primarily glucagon-producing cells in vitro, but insulin gene expression becomes dominant after passage in vivo. Interestingly, IAPP was hyperexpressed with glucagon under in vitro conditions in this clone. We conclude that the tissue specificity of expressions of IAPP and insulin are controlled differently, and that coexpression of IAPP with hormones different from insulin may be a marker for pluripotent transformed rat islet cell clones, which are able to activate insulin gene transcription during passage in vivo.

Amyloid↗
PubMed1991

Is islet amyloid polypeptide a significant factor in pathogenesis or pathophysiology of diabetes?

Islet amyloid polypeptide (IAPP) or amylin, a recently discovered minor secretory peptide of the beta-cell related to calcitonin gene-related peptide (CGRP), is a constituent of amyloid deposits in the islets of many non-insulin-dependent (type II) diabetic individuals and some elderly nondiabetic subjects. IAPP is synthesized as a small precursor at a level of approximately 1% that of insulin and is processed, amidated, stored in beta-granules, and released along with insulin and C-peptide. Analysis of its gene (located on chromosome 12) supports an evolutionary relationship to calcitonin and CGRP, peptides with which it shares some biological actions. Like CGRP, IAPP antagonizes the action of insulin mainly at the level of muscle glycogen synthesis, but the levels required for this effect seem to be considerably higher than reported circulating levels. No evidence for overproduction of IAPP in diabetic subjects has been found thus far, but much more work is necessary to define its normal secretory rates and clearance. Other proposed actions of IAPP include serum calcium-lowering effects and smooth muscle relaxation; the latter effect might promote the uptake of insulin into the circulation within the islets. Deposition of amyloid is species selective due to structural differences within the central part of the molecule and may be initiated intracellularly in type II diabetes by several mechanisms. No differences in the structure of IAPP or its precursor have been found in individuals with maturity-onset diabetes of the young or type II diabetes.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1991

[Clinical evaluation of severe toxicity in two patients with acute lymphoblastic leukemia receiving outpatient methotrexate therapy].

Methotrexate (MTX) is now widely used for the treatment of acute leukemia and non-Hodgkin lymphoma in the pediatric oncology field and is thought to be one of the key drugs for this treatment. A regimen utilizing high dose MTX (HD-MTX) with leucovorin rescue is being investigated as effective chemotherapy in the patients with these kinds of cancer. Relatively large amounts of MTX (225 mg/m2) are given to such outpatients by intravenous push as a course of maintenance therapy. It is said that those amounts will infuse safely. However, we experienced two serious cases-patients T.H. and M.Y.--which developed into severe side effects after this treatment. Both patients showed acute renal failure, severe myelosuppression, erosion around the oral and anal region, and continuous diarrhea. Judging from the serum concentration of MTX, patient T. H. was exposed to more than the maximum allowance serum MTX level for 9.6 days, patient M. Y. for 6.5 days. This suggests physicians must pay attention to the clinical symptoms even after treatment using MTX without HD-MTX.

Acute Kidney Injury↗
PubMed1991

Unusual signal broadening in NMR of oligonucleotides.

Solution structure of single-stranded small oligonucleotides (up to pentamer) has been studied by 1H-NMR (600 MHz) and it has been found that when those having some specific base sequences produce unusual broadening of the lines attributed to the protons of guanine residues. These broadened signals did not become sharp even at elevated temperature. This extremely unusual behavior has been attributed to the interaction between the guanine residues.

Hydrogen-Ion Concentration↗
PubMed1991

[Evaluation of effective neo-adjuvant chemotherapy (FLEP therapy) in the treatment of advanced gastric cancer].

Ten patients with non-resectable gastric cancer were subjected to a neo-adjuvant chemotherapy (FLEP therapy), consisting of 4 drugs (leucovorin and 5-FU i.v., CDDP and etoposide i.a.) combination therapy from August 1989 to April 1991. The response rate of this therapy with primary lesions, metastatic lymph-nodes (mainly paraaortic lymph nodes), metastatic liver tumor and peritoneal dissemination were 50, 50, 25 and 33%, respectively. Five cases underwent total gastrectomy. Pathological evaluation of these cases was Grade 1 or 2. Side effects were mainly gastrointestinal disturbances, namely stomatitis, nausea, vomiting and anorexia, along with bone marrow suppression. Performance status of these patients improved to a significant degree by the therapy. This therapy seemed to be effective in controlling paraaortic lymph-node metastasis. The advantage of i.a. delivery was investigated by Tc-MAA scintigraphy. The distribution of Tc-MAA after i.a. injection suggested that i.a. chemotherapy enhanced intraabdominal drug concentration. There is no established treatment for far advanced cases, so this therapy seems to be worth a try.

Adult↗
PubMed1991

[Possible radiation induced cancer of the thoracic esophagus after postoperative irradiation in breast cancer].

We report 11 cases with cancer of the thoracic esophagus developing after postoperative irradiation therapy for the breast cancer. Irradiation was done immediately after mastectomy in these cases and the irradiation field included the unilateral or bilateral parasternal region. They received a total dose ranging from 35 Gy to 60 Gy and the dose received to the thoracic esophagus was estimated from 10 Gy to 48 Gy. All cancer sites were involved in the irradiation filed. The latent intervals of 10 cases from radiation to the manifest of cancer ranged between 10 to 19 years. Among 4777 women undergone mastectomy for breast cancer between 1946 and 1980 in our hospital, 8 women (0.17%) developed cancer of the thoracic esophagus, whereas 5 (0.335%) out of 1534 women treated with mastectomy and radiotherapy with Linac between 1964 and 1980 developed cancer of the thoracic esophagus. Higher incidence of esophageal cancer in patients treated with surgery and radiation suggests that these cancers might be induced by radiation. Eight patients had esophagectomy and 4 patients of them received postoperative irradiation. They have survived from 9 months to 13 years. Two patients were controlled well by the irradiation alone. It is interesting that radiation therapy is sensitive to the possible radiation induced cancer of the thoracic esophagus. Follow up study should be directed to the possible development of second malignancy in patients who survive for a long time after radiation therapy.

Adenocarcinoma↗