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Biomedical subjects

N Yoshimi

Publications and source records attributed to N Yoshimi.

At least 109 records · Page 6Linked to original sources
PubMed1993

Modifying effects of benzyl isothiocyanate and benzyl thiocyanate on DNA synthesis in primary cultures of rat hepatocytes.

The effects of benzyl isothiocyanate (BITC) and benzyl thiocyanate (BTC) on two types of DNA synthesis were examined in hepatocyte primary cultures (HPC). Male F344 rats were fed BITC- or BTC-containing diets at a concentration of 400 p.p.m. Using hepatocytes isolated from these rats, DNA repair was measured by unscheduled DNA synthesis (UDS) for some genotoxic carcinogens, e.g. 2-acetylaminofluorene (AAF), methylazoxymethanol (MAM) acetate, 9,10-dimethyl-1,2-benzanthracene (DMBA) and diethylnitrosamine (DEN), and compared with that in the hepatocytes from rats without BITC or BTC treatment. Replicative DNA synthesis (RDS) was also evaluated in the hepatocytes of rats with or without thiocyanate treatment. Both BITC and BTC reduced UDS elicited by these carcinogens. The level of RDS in the hepatocytes of rats exposed to BITC or BTC was markedly lower than in the cells of rats without BITC or BTC exposure. These results indicate that in vivo exposure to BITC and BTC suppressed carcinogen-induced genotoxicity and cell proliferative activity and suggest that this assay may prove useful in detecting chemopreventive agents for cancer and in investigating the properties of carcinogenesis modifiers.

Animals↗
PubMed1993

The numerical aberrations of chromosome 7 detected by fluorescence in situ hybridization in human breast cancers.

The relationship between the numerical aberrations of chromosome 7 in interphase cells and the clinicopathological behavior of breast tumors was investigated in 51 touch imprinted preparations of breast tumors. Using fluorescence in situ hybridization with a chromosome 7-specific DNA probe, the fluorescein-isothiocyanate (FITC) spots mean and the representative copy number of each breast tumor were examined. The FITC spots mean (2.34) of 40 breast cancers increased compared with that of 11 benign lesions (1.98) (P < 0.02). The FITC spots mean tended to increase with the advancing stage and tumor size of the breast cancer. The FITC spots mean in the case with metastasis was also of a higher value than that without metastasis (P < 0.01). Furthermore, the existence of trisomy or over-trisomy of the copy number was related to the advancing stage and tumor size (P < 0.05 and P < 0.01, respectively). These findings suggest that the FITC spots mean and polysomy of the number of chromosome 7 may be highly predictive for breast tumor aggressiveness.

Adult↗
PubMed1993

Morphological changes of the nucleolar organizer regions induced by 7,12-dimethylbenz[a]anthracene in the hamster cheek pouch.

The staining of nucleolar organizer regions (NORs), which equate to rDNA transcription, was applied to chemically induced-lesions of the hamster cheek pouch. The cheek pouches of 16 male golden Syrian hamsters were treated three times a week with 0.5% 7,12-dimethylbenz[a]anthracene (DMBA) in mineral oil for 16 weeks. The percentage of gathered-type NORs with high activity nucleoli increased in the pouch epithelium during DMBA treatment and reached the highest values in malignant tumors. The percentage of dispersed-type NORs also increased in the malignant lesions. However, the absolute number of NORs was not affected by DMBA treatment. These results suggest that DMBA induces modification of NOR activity at the early stages of carcinogenesis and shows the potential of this model for studying NOR alterations in neoplasia.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1993

Localization of the placental form of glutathione S-transferase messenger ribonucleic acid in human glioma cell lines.

Localization of the placental form of glutathione S-transferase (GST-pi) messenger ribonucleic acid (mRNA) in three human glioma cell lines (A172, T98G, and Tc77) was studied by in situ hybridization with digoxigenin-labeled GST-pi complementary DNA followed by immunocytochemistry with antidigoxigenin antibody. A172 glioma cells showed hardly any GST-pi mRNA. GST-pi mRNA was recognized in the cytoplasm of T98G and Tc77 glioma cells. Tc77 cells especially had a strong expression of GST-pi mRNA. GST activity and the expression of GST-pi protein were also investigated for these cell lines. Cytosolic GST activity was determined with 1-chloro-2,4-dinitrobenzene as substrate, and the results were as follows: A172, 24.3 +/- 2.0; T98G, 60.8 +/- 4.9; Tc77, 84.0 +/- 1.7 (mean +/- standard deviation, in nanomoles per minute per milligram of protein). The expression level of GST-pi protein analyzed by Western blotting with anti-GST-pi antibody as a primary antibody was compatible with the results of both in situ hybridization of GST-pi mRNA and GST activity. A172 cells possessing the lowest GST activity showed a weak expression of both GST-pi mRNA and protein. Tc77 cells with the highest GST activity had the strongest expression of GST-pi mRNA and protein in three cell lines. The GST-pi expression of T98G cells was moderate. These findings indicate that some human glioma cells have GST-pi expression and that GST-pi in glioma cells is the major isozyme of GSTs for the significant activity of glutathione conjugation.

Blotting, Western↗
PubMed1992

Inhibitory effect of 5-hydroxy-4-(2-phenyl-(E)-ethenyl)-2(5H)-furanone, a novel synthesized retinoid, on azoxymethane-induced intestinal carcinogenesis in rats.

Modifying effects of 5-hydroxy-4-(2-phenyl-(E)-ethenyl)-2(5H)-furanone, a novel synthesized retinoid (KYN-54), on intestinal carcinogenesis were examined in a rat model using azoxymethane (AOM). A total of ninety male F344 rats, 6 weeks old, were divided into 4 groups. Group 1 (20 rats) was fed a diet containing KYN-54 at a concentration of 0.02% for 3 weeks, during which time 2 s.c. injections of azoxymethane (15 mg/kg) were applied and then kept on a basal diet until the end of the experiment (1 year). Group 2 (30 rats) was given azoxymethane as in group 1 and fed the basal diet throughout, without synthetic retinoid exposure. Group 3 (20 rats) was administered KYN-54 at the commencement of the experiment, but not given the carcinogen. Group 4 (20 rats) received a basal diet alone throughout the experiment and served as a control. Intestinal tumors were seen in groups 1 and 2, their incidence and average number in group 1 (74%, 1.07 +/- 0.87) being significantly less than in group 2 (39%, 0.56 +/- 0.78) (P < 0.02 and P < 0.05, respectively). These results suggest that the synthetic retinoid might be a promising chemopreventive agent for intestinal neoplasia.

4-Butyrolactone↗
PubMed1992

A rare case of serous cystadenocarcinoma of the pancreas.

Serous cystadenocarcinoma of the pancreas, a rare disease, developed in a 63-year-old Japanese woman. Pathologic examinations of the pancreatic tumor at the subtotal pancreatectomy showed it to be serous cystadenoma with focal atypical lesions. Three years after the operation, however, metastatic liver nodules were found, and the histologic characteristics of these lesions were quite similar to those of the pancreatic neoplasm. Both primary and metastatic tumors were composed of multiple cysts separated by fibrous septa. The epithelium of cysts was cuboidal and had clear cytoplasm, which had positive results for periodic acid-Schiff (PAS) and negative results for PAS with diastase, Alcian blue, and mucicarmine. To the knowledge of the authors, serous cystic neoplasms of the pancreas have been uniformly benign in biologic behavior. Recently, however, serous cystadenocarcinoma of the pancreas has been reported as a new entity. The current case is the second reported case and might support the existence of serous cystadenocarcinoma of the pancreas.

Cystadenocarcinoma↗
PubMed1992

Effect of magnesium hydroxide on methylazoxymethanol acetate-induced epithelial proliferation in the large bowels of rats.

The effect of magnesium hydroxide on the epithelial proliferation of the large bowel was examined using rats given methylazoxymethanol (MAM) acetate. Dietary administration of magnesium hydroxide at 250, 500, 1000 or 2000 ppm. for 1, 3 or 5 weeks did not influence the cell cycle of the cryptal cells of the large bowel. However, the exposure to magnesium hydroxide under these conditions lowered the bromodeoxyuridine labeling index of the cells of the large bowel of the rats which had been initiated by MAM acetate (25 mg/kg, 3 times). The decrease in labeling index was more apparent in the proximal segment than in the distal segment. Such an inhibitory effect on the DNA synthesis of the epithelial cells by magnesium hydroxide may be related to the suppressive action of the trace element on the carcinogen-induced large bowel carcinogenesis.

Animals↗
PubMed1992

Extra-adrenal pheochromocytoma-ganglioneuroma. A case report.

A case of rare extra-adrenal tumor composed of pheochromocytoma-ganglioneuroma which developed in a 48-year-old Japanese male is reported. Histologically, the tumor contained equal proportion of two distinct patterns, pheochromocytoma and ganglioneuroma. Immunohistochemical examination revealed that pheochromocytoma cells were positive for Leu-7 and ganglion cells in ganglioneuroma were positive for vasoactive intestinal peptide (VIP), respectively. Neuron specific enolase (NSE) was positive in the neoplastic cells of both components, and S-100 protein was also positive in fibers around ganglion cells. Ultrastructural examination revealed that neurosecretory granules were present in the neoplastic cells.

Ganglioneuroma↗
PubMed1992

Cell kinetic analysis of the mucosal epithelium and assay of ornithine decarboxylase activity during the process of 1-hydroxyanthraquinone-induced large bowel carcinogenesis in rats.

Cell kinetics and activity of ornithine decarboxylase (ODC) were studied during the process of 1-hydroxyanthraquinone (1-HA)-induced intestinal carcinogenesis in rats. Starting at 6 weeks of age, a total of 37 male ACI/N rats were divided into two groups and treated as follows: group I (18 rats) received diet containing 1% 1-HA for 12 months; group II (19 rats) was given the basal diet alone. Sub-groups of 5-7 rats were sequentially killed at 4, 8 and 12 months for evaluation of the length, cell numbers and 5-bromo-2'-deoxyuridine (BrDU) labeling indices of large bowel crypts together with ODC activity. All kinetic and ODC data indicated increased DNA synthesis and proliferation at all time points. Morphological observation of the intestines also revealed melanosis, crypt abscesses and erosion, becoming more pronounced with length of exposure to the anthraquinone. The data thus suggest that cell proliferation in the crypts of the cecum or colon is important for 1-HA-induced intestinal carcinogenesis.

Animals↗
PubMed1992

Modifying effects of fungal and herb metabolites on azoxymethane-induced intestinal carcinogenesis in rats.

Modifying effects of a fungal product, flavoglaucin, and four plant-derived chemicals, shikonin, gingerol, oleanolic acid and paeoniflorin, on intestinal carcinogenesis were examined in a rat model using azoxymethane (AOM). A total of 280 male F344 rats, 6 weeks old, were divided into 12 groups. Group 1 (30 rats) was given two subcutaneous injections of 15 mg/kg of AOM at the start of the experiment. Groups 2 (30 rats), 3 (20 rats), 4 (20 rats), 5 (30 rats) and 6 (30 rats) received a test chemical (flavoglaucin, shikonin, gingerol, oleanolic acid or paeoniflorin, respectively) in the diet at a concentration of 0.02% for 3 weeks, during which time AOM was applied, and then kept on basal diet until the end of experiment (one year). Groups 7-11 (each 20 rats) were given a test chemical corresponding to Groups 2-6, respectively. Group 12 (20 rats) served as a control. The incidence and average number of intestinal tumors in Group 2 (47%, 0.57 +/- 0.68) were significantly less than in Group 1 (74%, 1.07 +/- 0.87) (P < 0.05, respectively). Multiplicity of intestinal neoplasms of Group 3 (0.55 +/- 0.60) or 4 (0.47 +/- 0.51) was also significantly smaller than that of Group 1 (P < 0.05 and P < 0.01, respectively). These results suggest that flavoglaucin, shikonin and gingerol might be promising chemopreventive agents for intestinal neoplasia.

Animals↗
PubMed1992

Primary malignant melanoma of the urinary bladder.

Primary malignant melanoma is an unusual neoplasm in the urinary bladder that is infrequently found in association with melanosis. We report a case of bladder-invasive malignant melanoma with melanosis in which the melanosis exhibited melanocytic atypia extending through to melanoma in situ and was diagnosed by immunohistochemical techniques using a monoclonal antibody, HMB-45. To our knowledge, such findings have not been reported previously.

Antibodies, Monoclonal↗
PubMed1991

Second meiotic nondisjunction of the rearranged chromosome in a familial reciprocal 5/13 translocation.

We describe a 20-week-gestation male fetus with partial dup(5p) and proximal dup(13q), 47,XY,t(5;13)(p15;q21), + der(13)t(5;13)(p15;q21) mat. This finding is attributable to second meiotic nondisjunction of the rearranged chromosome in a maternal balanced reciprocal translocation. To the best of our knowledge, there have been only 3 previous reports of a similar error in the segregation of the rearranged chromosomes. For the first time evidence has been given that this unusual segregation is due to maternal second meiotic nondisjunction, using QFQ banding heteromorphisms. Second meiotic malsegregation should be taken into account in the consideration of reproductive problems in carriers of balanced translocations.

Abnormalities, Multiple↗
PubMed1991

Rapid detection of proliferating potential in human brain tumors by nucleolar organizer region staining on squash preparations.

Rapid detection of the proliferating potential of 37 human brain tumors was attempted using squash preparations stained by a silver colloid technique for argyrophilic protein associated with nucleolar organizer regions (AgNORs). Less than 1 h was required for staining. The mean number of AgNORs in cell nuclei of malignant or recurrent brain tumors (16 cases) including meningeal sarcoma, recurrent meningioma, recurrent craniopharyngioma, anaplastic astrocytoma, glioblastoma multiforme and metastatic brain tumor was 3.18, and the number for benign brain tumors (21 cases) including meningioma, neurinoma, pituitary adenoma, benign astrocytoma, ependymoma, and adenoma of lachrymal gland was 1.85. The former value was significantly greater than the latter value (P less than 0.001). These results indicate that quantitative analysis of AgNORs in brain neoplastic cells, using squash preparations, is useful to differentiate malignant from benign tumors within 1 h. Thus, this method provides rapid and useful information about the proliferative potential of human brain tumors even during operation.

Adenoma↗
PubMed1991

Fine-needle aspiration cytology of xanthogranulomatous pyelonephritis.

Fine-needle aspiration cytology of xanthogranulomatous pyelonephritis in a fifty-seven-year-old Japanese woman is reported. Foamy cells and cells showing a gland-like pattern originating from degenerative renal tubules were found in the aspirated smears. Multinucleated giant cells and cells with pale yellowish cytoplasm were seen in the imprint smears at operation. These findings were diagnostic for xanthogranulomatous pyelonephritis. The cytologic diagnostic differences among xanthogranulomatous pyelonephritis, well-differentiated renal cell carcinoma, and renal oncocytoma are also described.

Biopsy, Needle↗
PubMed1991

Inhibitory effect of the non-steroidal anti-inflammatory drug, indomethacin on the naturally occurring carcinogen, 1-hydroxyanthraquinone in male ACI/N rats.

The effect of the non-steroidal anti-inflammatory drug indomethacin on 1-hydroxyanthraquinone (1-HA)-induced carcinogenesis was investigated in male ACI/N rats. Animals were fed the diet containing 1.5% 1-HA and simultaneously given indomethacin solution (16 p.p.m.) as drinking water for 48 weeks. The incidences of large bowel neoplasms (adenomas and adenocarcinomas) and forestomach (papillomas) in rats given 1-HA and indomethacin (large intestinal tumors: 0/14, 0%; forestomach tumors: 2/14, 14%) were significantly lower than those in rats given 1-HA alone (large intestinal tumors: 12/27, 44%; forestomach tumors: 14/27, 52%) (P = 0.002 and P = 0.01 respectively). Liver cell adenomas were developed in a rat given 1-HA and no liver tumors in rats treated with 1-HA and indomethacin. Altered liver cell foci were present in rats given 1-HA alone (18/27, 67%) and those given 1-HA and indomethacin (8/14, 57%), but no significant difference in the incidence between the two groups was found. Untreated animals and rats given indomethacin alone had no neoplasms in the large bowel, forestomach and liver. Thus, the non-steroidal anti-inflammatory drug indomethacin significantly inhibited carcinogenesis induced by the naturally occurring carcinogen, 1-HA.

Adenocarcinoma↗
PubMed1991

Alterations of the nucleolar organizer regions during 4-nitroquinoline 1-oxide-induced tongue carcinogenesis in rats.

The number of silver-stained nucleolar proteins (AgNORs) was enumerated in preneoplastic and neoplastic rat tongue lesions induced by 4-nitroquinoline 1-oxide (4-NQO). Male ACI/N rats were given 0 to 10 p.p.m. 4-NQO for 12, 20 or 36 weeks to induce hyperplasia, dysplasia and neoplasm in tongue. The mean numbers of AgNORs stained by a modified one-step silver colloid method in various epithelial lesions were as follows: normal squamous epithelium (n = 5), 1.52 +/- 0.03; non-lesional squamous epithelium (n = 5), 1.58 +/- 0.04; hyperplasia (n = 20), 1.84 +/- 0.15; dysplasia (n = 20), 2.32 +/- 0.12; papilloma (n = 6), 2.23 +/- 0.10; and squamous cell carcinoma (n = 4), 3.06 +/- 0.26. Thus, the mean number of AgNORs showed a stepwise increase from untreated and treated, histologically normal squamous epithelium through hyperplasia and dysplasia to squamous cell papilloma and carcinoma, although the value of severe dysplasia was between those of papilloma and carcinoma. These results indicate that the mean number of AgNORs may reflect the proliferative nature of tongue lesions, as suggested in carcinogenesis of other organs, and also suggest that severe dysplasia is a direct precursor lesion for squamous cell carcinoma of the tongue induced by 4-NQO.

4-Nitroquinoline-1-oxide↗