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T Ashihara

Publications and source records attributed to T Ashihara.

At least 55 records · Page 3Linked to original sources
PubMed1996

[Clonal analysis of hepatocellular carcinoma].

We investigated the cell clonality of 12 cases of female solitary hepatocellular carcinoma (HCC) that were associated with hepatitis virus infection. The clonal origin of HCC could be assessed by the method based on restriction fragment length polymorphism (RFLP) of X-chromosome-linked androgen receptor gene (AR) and phosphoglycerate kinase (PGK) gene, taking advantage of random inactivation of one of two X-chromosomes by methylation in females. We extracted DNA samples from both fresh and paraffin-embedded specimens of the same lesion as a source of DNA sample for polymerase chain reaction (PCR). Consequently, it was possible to use methylation-sensitive restriction enzymes and PCR to study differential methylation patterns among alleles of these genes for both DNA samples. The RFLPs of AR gene and PGK gene were found in eight of 12 cases and five of 12 cases, respectively. There were two cases which had no RFLPs in either AR gene or PGK gene. All cases of HCC which had RFLP in either AR gene or PGK gene demonstrated monoclonal origin of the tumor regardless of their histologic patterns.

Aged↗
PubMed1996

Influence of downscatter in simultaneously acquired thallium-201/technetium-99m-PYP SPECT.

UNLABELLED: Simultaneously acquired dual-isotope imaging is a unique and useful approach in SPECT. Photon spillover, however, is a potential limitation of this technique. METHODS: To investigate the degree of 99mTc downscatter into the 201Tl window in patients, simultaneously acquired dual-isotope 201Tl/99mTc-pyrophosphate imaging was performed in 17 patients with acute myocardial infarction (MI). Thallium-201 SPECT imaging was performed first, with a 201Tl photopeak window after the 201Tl injection (early 201Tl images), followed by 99mTc injection and SPECT acquisition using dual-isotope windows (dual 201Tl images). Twenty-four hours after the 99mTc injection, a third set of 201Tl images was obtained (24-hr 201Tl images). Thallium defect size (extent score) and defect severity (severity score) were calculated from these three sets of 201Tl images to quantify the MI. RESULTS: Technetium-99m accumulation of varying intensity was recognized in all patients. Extent scores and severity scores were identical in early 201Tl images and 24-hr 201Tl images. Both scores, however, in the dual 201Tl images were decreased by 36% and 53%, respectively. CONCLUSION: There in a considerable 99mTc downscatter into the 201Tl window, which prevents precise quantification of MI in simultaneously acquired dual-isotope 201Tl/99mTc-pyrophosphate imaging.

Female↗
PubMed1995

Cell proliferation and differentiation of cultured chondrocytes isolated from growth plate cartilage of rat rib.

The present study was undertaken to investigate the relationship among cell morphology, proliferation, and maturation of chondrocytes in primary cultures. Chondrocytes were isolated from the growth cartilages of the rat ribs and cultured for 6 days. In situ DNA cytofluorometry using an inverted epi-illumination cytofluorometer (Nikon P1-I) and 3H-thymidine autoradiography were carried out for the correlated analysis of cell morphology and proliferation. Cytoskeletal staining with fluorescent phalloidin and 35S-sulphate autoradiography were also performed. In addition, in situ hybridization to c-myc mRNA was carried out using DNA probe. According to the results obtained, the cultured chondrocytes were composed of mixed populations of large, polygonal cells and of small, round cells. The round cells showed a significantly higher 35S uptake than the polygonal cells. The cytoskeletal staining clearly revealed stress fibers in the cytoplasm of the polygonal cells, whereas only a fine filamentous structure was shown in the cytoplasm of the round cells. In situ DNA cytofluorometry clearly demonstrated that cell proliferative activity was high in the polygonal cells and low in the round cells. In addition, 3H-thymidine autoradiography with cumulative labeling method revealed that the polygonal cells were changing into the small, round cells. C-myc mRNA signals were detected in the cytoplasm of over a half of the round cells, whereas no evidence of c-myc expression were found in the polygonal cells. From these results, it appears that as the shape of the cultured chondrocytes shifts from polygonal to round, the cell proliferative activity decreases in association with cell differentiation. It was also suggested that c-myc mRNA is amplified in the well differentiated round chondrocytes, and not in the proliferative polygonal cells.

Animals↗
PubMed1995

Iodine-123 metaiodobenzylguanidine images reflect intense myocardial adrenergic nervous activity in congestive heart failure independent of underlying cause.

OBJECTIVES: This study was undertaken to assess myocardial adrenergic activity using iodine-123 metaiodobenzylguanidine (MIBG) imaging in patients with heart failure. BACKGROUND: In patients with congestive heart failure, adrenergic nerve activity is accelerated. However, whether myocardial adrenergic nerve activity reflects the severity of heart failure and its relation to the underlying cause have not yet been elucidated. METHODS: Planar MIBG images were obtained from 96 patients with heart failure and compared with images from 9 age-matched healthy subjects. Groups 1 and 2 included 65 patients with heart failure related to impaired myocardial function and whose left ventricular ejection fraction was < 40% (group 1 = 40 patients with dilated cardiomyopathy; group 2 = 25 patients with ischemic cardiomyopathy). Group 3 included 31 patients with heart failure related to a mechanical abnormality and whose left ventricular ejection fraction was > 40% (mitral regurgitation in 16, aortic regurgitation in 9, aortic and mitral regurgitation in 4, ruptured aneurysm of Valsalva in 2). Myocardial uptake of MIBG was calculated as the heart/mediastinal activity ratio. Storage and release of MIBG were calculated as percent myocardial MIBG washout from 15 min to 4 h after isotope injection. RESULTS: The heart/mediastinal activity ratio in the immediate images (15 min) showed a significant decrease only in patients with severe heart failure (groups 1 and 2). The myocardial washout was accelerated in all three heart failure groups. The level of myocardial washout was related to severity of heart failure and correlated well with New York Heart Association functional classification. CONCLUSIONS: In severe heart failure associated with cardiomyopathy, norepinephrine uptake is reduced. In addition, myocardial adrenergic nerve activity is accelerated in proportion to severity of heart failure, independent of the underlying cause.

3-Iodobenzylguanidine↗
PubMed1995

A staining method for bone canaliculi.

The modified Bodian method with protargol (silver protein) is ordinarily used to detect nerve fibers. With this technique, applied to decalcified rat bone sections, the bone canaliculi were clearly stained black with good contrast to the bone matrix in both lamellar and woven bone. In addition, the connections between the bone canaliculi and other canaliculi, osteoblasts, osteoclasts, and chondrocytes were easily detectable. We found that the bone canaliculi of woven bone were fewer in number and ran more irregularly than those of lamellar bone. We believe that this staining method for bone canaliculi in decalcified bone is superior to previously reported methods and may be useful in studies on bone pathology.

Animals↗
PubMed1995

[Management of polypoid lesions of the gallbladder by endoscopic ultrasonography (EUS)--a retrospective study to establish the diagnostic criteria and a prospective study to evaluate its reliability].

The diagnostic criteria of endoscopic ultrasonography (EUS) in the management of polypoid lesions of the gallbladder was established by a retrospective study using 57 cases with polypoid lesions of the gallbladder that were all resected and confirmed histologically. By this study, EUS findings of polypoid lesions of the gallbladder were classified into the following six groups; Type I with a foamy high echogram, Type II with a globular high echogram, Type III with a papillary high echogram, Type IV with a papillary solid echogram, Type V with a nodular solid echogram and Type VI with a nodular solid echogram including multiple spotty an-echoic areas which suggested the presence of Rokitansky-Aschoff sinus. Comparing the types of EUS findings with histological diagnosis, Type I and II corresponded to cholesterol polyps. Type III and IV contained benign pseudo tumors such as cholesterol polyp or hyperplastic polyp as well as tumorous lesions such as adenocarcinoma or adenoma. Type III with over 10 mm in size and IV with over 5 mm in size had a possibility of tumorous lesions. Type V usually corresponded to adenocarcinoma, and Type VI to adenomyomatous hyperplasia. From these results, the following criteria was established; (1) Polypoid lesions showing Type I, II, III with less than 10 mm in size, IV with less than 5 mm in size and VI should be followed-up as benign diseases. (2) Polypoid lesions of Type III with over 10 mm in size and IV with over 5 mm in size was considered to be relative indications for surgery as tumors. (3) Polypoid lesions of Type V was an absolute surgical indication as malignant. The reliability of this EUS criteria was followingly evaluated by a prospective study using 94 cases with polypoid lesions of the gallbladder; 32 cases with open or laparoscopic cholecystectomy and 62 cases with over one year follow-up observations. The criteria corresponded well with the histological or follow-up findings in Type I, II, III with less than 10 mm in size, IV with less than 5 mm in size, V and VI. It had, however, a tendency of over indications to surgery in Type III with over 10 mm in size and IV with over 5 mm in size because these types were widely set not to overlook tumorous lesions such as adenoma and small adenocarcinoma.(ABSTRACT TRUNCATED AT 400 WORDS)

Endoscopy, Digestive System↗
PubMed1994

Evaluation of hepatic proliferative activity in chronic liver diseases and hepatocellular carcinomas by proliferating cell nuclear antigen (PCNA) immunohistochemical staining of methanol-fixed tissues.

The proliferative activity of chronic liver diseases and hepatocellular carcinomas (HCCs) was studied by PCNA immunohistochemistry. Human liver tissues were obtained by surgical operation or needle biopsy, and PCNA was detected by immunohistochemistry. PCNA-labelling indices (PCNA-LIs) of methanol-fixed tissues corresponded with the incidence of S-phase cells previously reported, whereas paraformaldehyde-fixed tissues showed extremely high PCNA-LIs in all specimens. Therefore, methanol-fixed tissues were used for evaluation. The PCNA-LIs of the methanol-fixed tissues were: normal liver 0.78 +/- 0.38%, chronic persistent hepatitis 1.06 +/- 0.86%, chronic aggressive hepatitis 2A 1.01 +/- 0.50%, chronic aggressive hepatitis 2B 4.20 +/- 1.79%, inactive cirrhosis 0.81 +/- 0.49%, active cirrhosis 1.96 +/- 0.93%, HCC of Edmondson's type I 4.83 +/- 1.98%, type II 6.65 +/- 1.69%, and type III 38.7 +/- 30.6%. PCNA-positive cells showed little specific distribution; in periportal areas in chronic hepatitis, at the margins of pseudolobules in cirrhosis, and throughout the tumor in HCC. These findings indicated that proliferative activity increased during the progression of chronic hepatitis, but that it decreased at the stage of cirrhosis. In chronic liver diseases, the PCNA-LIs reflected hepatitis activity. HCC showed higher proliferative activity than liver cirrhosis, and the histological grade was correlated with the PCNA-LI.

Analysis of Variance↗
PubMed1994

[Cytofluorometric chase of the cancer cells after release from G2-block induced by peplomycin].

To study the alteration of nuclear DNA content of cancer cells after peplomycin (PEP) treatment, DNA cytofluorometry was performed in combination with 3H-thymidine (3H-TdR) autoradiography using cultured A431 cells. The cells in the logarithmic growth were treated with PEP (1.25 micrograms/ml) for 24 hr, during the first 4 hr of which they were pulse-labeled with 3H-TdR (2.4 x 10(4) Bq/ml). After washing with PBS, the cells were then cultured without both PEP and 3H-TdR, fixed at different times and stained with propidium iodide (PI) for the auto-stage cytofluorometry, which enabled DNA content analysis for labeled and unlabeled cells by repeated scanning of the same cell population. The nuclear DNA content histograms demonstrated that A431 cells were mostly arrested in G2 phase of 4C stem line by treatment with PEP for 24 hr. This G2 block lasted up to 8 hr after removal of the drug, and thereafter, marked polyploidization associated with DNA synthesis occurred, showing almost no mitotic figures, while only a few cells returned to G1 phase via M phase. During the period of 72-120 hr, however, the fractions of advanced polyploid cells (DNA content > or = 8C) gradually decreased and the DNA content distribution pattern became eventually similar to the original one as seen before PEP treatment. From these results we hypothesized as follows: 1) At S-G2 boundary, there is some control mechanism that checks whether the cells, after S phase, can enter the M phase or not. 2) The cells, which are not permitted to enter mitosis by the control mechanism, show marked polyploidization. 3) Only the cells that enter into mitosis can live and proliferate, though the advanced polyploid cells die shortly. 4) This control mechanism might be related to the precision of DNA repair that is checked at the G2-M checkpoint.

Autoradiography↗
PubMed1993

Cytofluorometric analysis of spermatocytic seminoma.

Whether spermatocytic seminoma (SS) develops during meiosis or not is still controversial. To determine that, the DNA content of large, small, and intermediate cells of SS was measured by cytofluorometry to obtain DNA histograms for each cell type. The large cells were aneuploid and showed cell cycles with G0/G1 DNA values from 3C to 18C. The ploidy of the large cells doubled stepwise (i.e., 4.5C-9C-18C, 3C-6C-12C, and so forth). The small cells showed distinct cell cycles with a DNA content of 2C or near 2C, and the intermediate cells showed both diploid and aneuploid DNA values. It is speculated that none of the cell types is involved in meiosis, based on the fact that each size of cell appears to have its own cell division cycle. It is concluded that in SS, the diploid cell cycle formation by small cells and the creation of large cells by continuous sequential polyploidization result in the morphologic expression of three types of cells (large, small, intermediate).

Adult↗
PubMed1993

Safety and accuracy of dipyridamole thallium myocardial scintigraphy in elderly patients.

This study examined mainly the adverse effects of 201Tl myocardial scintigraphy with dipyridamole (D-Tl) in 73 elderly patients over 70 years old in comparison with those in 65 younger patients. Fifty-five of 73 elderly patients (75%) and 49 of 65 younger patients (75%) had a persistent or dipyridamole-induced perfusion defect on D-Tl. The hemodynamic changes induced by dipyridamole as well as the incidence of cardiac and noncardiac adverse effects were similar in both groups and no serious adverse effect occurred in either group. Secondly, we examined the procedure's usefulness for detecting ischemic heart disease in elderly and younger patients. Dipyridamole induced perfusion defect was noted in 21 elderly patients and in 24 younger patients (N.S.). Among the patients in whom coronary angiography was performed, significant coronary artery stenosis was found in 5 of 8 elderly patients and 17 of 20 young patients (N.S.). In patients with one or two-vessel disease, the area with dipyridamole induced ischemia was concordant with the stenotic area seen on coronary angiography in 3 of 3 elderly patients and 12 of 13 younger patients (N.S.). Thus, the safety and usefulness of D-Tl for detecting myocardial ischemia were comparable in elderly and young patients.

Age Factors↗
PubMed1993

[An autopsy case of the sinus of Valsalva aneurysm involved with tuberculous inflammation, leading to complete heart block].

A case is presented of unruptured aneurysm of the non coronary sinus of Valsalva, causing involvement of A-V node and right coronary artery compression. The patient was a 68 year-old woman with a complaint of general fatigue. Electrocardiogram showed complete A-V block. Computed tomography showed an aneurysm of the non coronary sinus of Valsalva. A temporary pacemaker was implanted, but the patient developed respiratory failure and heart failure and died. At autopsy, macroscopically disseminated tuberculosis was noted in both lungs and kidneys. Microscopically a tuberculous inflammatory lesion extending into the A-V node was found. We report this rare case with some consideration of the literature.

Aged↗
PubMed1993

[Endoscopic sphincterotomy for lithotripsy (EST-L) of bile duct stones].

We performed EST-L for 555 patients with choledocholithiasis between 1981 and 1992. With the aid of conventional occlusion balloons and dormia-type baskets, calculi < or = 1.5 cm was extracted with relative ease. In patients with larger stone (> 1.5 cm), the mechanical lithotripter, extracorporeal shock wave lithotripsy (ESWL) and electrohydrolic lithotripsy were used for the lithotripsy. The overall success rate was 95%. Important early and late complications from these procedures occurred in 6.9% and 9.1% of all cases respectively. This result reveal that EST-L is safe and effective therapeutic procedures for choledocholithiasis. We would recommend EST-L is adopted as an initial measure to remove common bile duct stones.

Bile Duct Diseases↗
PubMed1993

[Image analysis on isolated colorectal tumor cells].

Image analysis of the nuclear morphology was performed on propidium iodide-stained isolated cells from 9 adenomas and 9 cancers of the colorectum. We analyzed DNA content, seven nuclear geometric features and four shape factors of tumor cells using an image cytometry system that has been developed in our laboratory. Nuclear breadth and the degree of contour irregularity of cancer cells were found to be significantly different from those of adenoma cells. The coefficients of variation (CV) of some nuclear features and the degree of contour irregularity were increased in cancer cells, while CV of the degree of circularity was increased in adenoma cells. Moreover, nuclear in G2 phase were found to be larger and more round than those in G1 phase. These results suggest that cell-cycle-related analysis of nuclear features would be a valid means to assess the nuclear morphology of colorectal tumors.

Adenocarcinoma↗
PubMed1993

[DNA-cytofluorometric, histopathological and immunohistochemical analyses of pancreatoduodenal cancers].

To study the cell characteristics of relatively small pancreatoduodenal cancers (less than 4 cm in the greatest dimension in histopathological examination), we analyzed the relation between the cell kinetics, and histopathological and immunohistochemical findings. Tumors were classified into t1 (0-2 cm in its greatest dimension) and t2 (2-4 cm). We analyzed DNA contents of five tumors of t1 and twelve of t2 by cytofluorometry. Histopathological and immunohistochemical (CA19-9 and CEA) examinations were also carried out. Nuclear DNA content histograms of the tumors in the t1 group showed all diploid pattern, while those in the t2 group exhibited 4 diploid, 7 euploid polyploid and 1 aneuploid patterns. Invasions to the lymphatic (ly), vein (v) and nerve (pn) were found in five cases of diploid tumors (3 of t1 and 2 of t2) and all (8 in t2) of non-diploid tumors. A medullary pattern of tumor growth was only noted in three tumors of t1. This pattern was not found in t2 (4 diploid, 8 non-diploid). These results suggest that the cellular DNA content increased in association with the tumor growth in size. In the histopathological findings, both the invasions (ly, v, pn) and fibrosis of the stroma more often appeared as the tumor size and polyploid and aneuploid cells increased. However, other histopathological findings and the immunohistochemical examination for CA19-9 and CEA had no relation to the tumor growth and the DNA ploidy pattern.

Aged↗
PubMed1992

[Progress in microscopic image analysis and the trend of image cytometry].

Image cytometry has recently developed prominently based on the digital imaging of cell morphology brought about by great advances in microcomputer hardware and software, electronics etc. This method is characterized by the quantitation of both the amount of intracellular bioactive materials and cell morphology, and is expected to further advance many cell analysis techniques involving automated cytology, chromosome image analysis, automated histopathology, viable cell analysis, 3D image construction, etc. The present use is still minimal, and advances in both hardware and software for cyto-histologic recognition are essentially necessary. Perhaps by the end of this century, more sophisticated and faster machines for automated cyto-histologic analysis will appear, replacing many microscopic techniques of presently subjective observation in the biomedical field.

Cell Cycle↗
PubMed1992

[The usefulness of dipyridamole stress myocardial scintigram as a preoperative test for detecting ischemic heart disease before vascular surgery].

We evaluated the usefulness of dipyridamole 201Tl myocardial scintigraphy (DS) for detecting myocardial ischemia in 18 candidate for vascular surgery. DS indicated significant thallium redistribution in 6 patients. Coronary angiography was performed in 5 of these 6 patients and revealed significant coronary artery disease in all patients. As a result, operation was cancelled in 4 patients with severe coronary artery disease. One of these cases died of acute myocardial infarction after being discharged from hospital. One other patient was operated after percutaneous transluminal coronary angioplasty. Another patient was operated knowing that he had significant but mild coronary artery disease. Subsequently, operations were performed in 14 patients. No serious cardiac event occurred in these 14 patients except one case with T wave inversion without myocardial enzyme elevation. Thus, we concluded that DS was a useful method for detecting ischemic heart disease and prevent cardiac event associated with vascular surgery.

Aged↗
PubMed1992

[Analysis of cell proliferation kinetics and the effects of cisplatin on the cell cycle of human gastric cancer cells by autostage cytofluorometry].

Analysis of both cell proliferation kinetics and effects of cis-diamminedichloroplatinum (CDDP) on cell cycle in human gastric cancer cell line (HGC-Y2) by measuring the contents of nuclear DNA, RNA and the Ki-67 antigen using autostage cytofluorometry system was described. In HGC-Y2 cells, RNA content increased during the cell cycle and reached to the maximum at G2/M phase. The results of pulse treatment with CDDP on these cells demonstrated a prolongation of S phase and G2 arrest with increasing of RNA content of these cells. We classified the cells by intranuclear distribution pattern of Ki-67 antigen and thus could identified the cells at G0 and M phases from these classification. The content of Ki-67 antigen was moderate grade at G1 phase and it decreased in the early S phase, then increased gradually during S phase and at the late S phase. It increased rapidly, reaching to the maximum at G2/M phase. After CDDP treatment, the content of Ki-67 antigen increased in the cells in prolonged S phase and in the cells arrested at G2 phase. It was also found that the syntheses of both Ki-67 antigen and RNA were not inhibited by CDDP. These results suggest that the method using autostage cytofluorometry system was useful for the research, on the mechanism of cancer therapy because of making possible to analyze precisely the cell cycle and the influence of anticancer drugs.

Cell Cycle↗