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Biomedical subjects

A Tanimoto

Publications and source records attributed to A Tanimoto.

At least 73 records · Page 4Linked to original sources
PubMed1994

Ambient pressure stimulates immortalized human aortic endothelial cells to increase DNA synthesis and matrix metalloproteinase 1 (tissue collagenase) production.

In the present study, we investigated the effect of ambient pressure on [3H]-thymidine incorporation and on the production of matrix metalloproteinase 1 (tissue collagenase/proMMP-1) using human aortic endothelial cells immortalized with simian virus 40 (SE-1). Incubation of cells at ambient pressures of 50 and 100 mmHg for 24 h slightly increased [3H]-thymidine incorporation when directly compared with normal culture conditions. The amount of [3H]-thymidine incorporated in SE-1 reached a maximum at 150 mmHg, while a further increase in pressure to 200 mmHg decreased incorporation. The same ambient pressure slightly stimulated human aortic intimal smooth muscle cells (SMC) to increase [3H]-thymidine incorporation but not medial SMC. Immunoblot analysis also showed that ambient pressure, ranging from 50 to 200 mmHg, like 12-O-tetradecanoyl-phorbol-13-acetate stimulated SE-1 to produce proMMP-1, an effect not seen with either intimal or medial SMC. The amount of proMMP-1 produced also reached a maximum level at 150 mmHg. We postulate that human endothelial cells are ambient pressure sensitive and that relatively lower ambient pressures play an important role in the growth of endothelial cells, while higher pressures injure endothelial cells, resulting in the initiation of atherosclerosis. This cell line may prove useful in the investigation of both the physiological and pathological roles of blood pressure on endothelial cell function.

Aorta↗
PubMed1994

Foreign-body granuloma mimicking an extrahepatically growing liver tumor: report of a case.

We herein describe a 74-year-old woman with a foreign-body granuloma mimicking a liver tumor. Imaging studies revealed a pedunculated left lobe mass in the setting of chronic liver disease. She had a past history of a cholecystectomy as well as a previous gynecological operation. A left lateral segmentectomy was performed because of the possibility of a rupture. The dissected specimen showed a foreign-body granuloma caused by gauze. We believe this case to be a very unique granuloma, which should be kept in mind whenever making a diagnosis of a liver tumor particularly in a patient with chronic liver disease, who has a past history of abdominal surgery.

Aged↗
PubMed1994

The receptor, metabolism and effects of androgen in osteoblastic MC3T3-E1 cells.

We investigated the androgen receptor (AR), metabolism and effects of androgens in osteoblastic MC3T3-E1 cells. AR was proved as a transcript of a 10-kb mRNA and as a 110-kDa protein. An immunocytochemical study showed that AR was located mainly in the nuclei. Specific binding of [3H]DHT was observed in both the nuclear and cytosol fractions. MC3T3-E1 cells possessed approximately 1190 binding sites per cell and most of the sites (1150 sites) situated in the nucleus. The apparent Kd value in the nuclear fraction was 1.35 nM for [3H]DHT binding, and it was similar to that for [3H]testosterone. In the competition analysis, there was not much difference in the displacement of the [3H]DHT binding from AR between the addition of radioinert DHT and testosterone. In studies of 5 alpha-reductase activity and aromatase activity of the cells, both activities were lower than the respective values in classical androgen target tissues. Androgens stimulated the incorporation of [3H]thymidine into the cell, and DHT and testosterone had a similar potency on the cell proliferation. Thus, these results suggest testosterone itself acts mainly on the osteoblasts without conversion to DHT.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗
PubMed1994

Cytopathological changes induced by cadmium-exposure in canine proximal tubular cells: a cytochemical and ultrastructural study.

A highly sensitive cytochemical method for demonstrating intracellular Cd using 8-hydroxyquinoline was developed and applied in the cytopathological study of primary-cultured renal tubular cells from beagle kidneys. The Cd-8-hydroxyquinoline emitted a yellowish-green fluorescence which first appeared in the cytoplasm within 30 min and in the nucleus about 60-90 min after exposure to 100 mM CdCl2. It was noteworthy that intranuclear Cd was stained in the nucleolar regions. The sensitivity of the cytochemical method for Cd was estimated to be about 1.0 pg Cd/cell. Ultrastructural features of the dead cells were consistent with those of apoptosis. We conclude that Cd absorbed by proximal tubular cells rapidly reaches to the nuclei and affects nuclear as well as cytoplasmic metabolism.

Animals↗
PubMed1993

A combined occurrence of neuroendocrine carcinoma of the skin and a benign appendageal neoplasm.

A 76-year-old Japanese male presented with a subcutaneous nodule in the dorsal cubital region of the right arm. The center of the nodule showed typical features of neuroendocrine carcinoma of the skin. The peripheral portion showed epithelial islands of squamoid cells with horn cysts suggestive of benign appendageal tumor with pilar differentiation. The coexistence of two skin neoplasms in the same lesion would suggest that both tumors developed from common pluripotential stem cell.

Aged↗
PubMed1993

Orally administered manganese chloride: enhanced detection of hepatic tumors in rats.

To evaluate its potential as a tissue-specific hepatobiliary magnetic resonance (MR) contrast agent, manganese chloride was orally administered to rats in increasing doses of 100-1,500 mumol/kg MnCl2, and the relaxation times of liver, pancreas, kidney, and heart were measured with ex vivo relaxometry and in vivo MR imaging. Two hours after ingestion of 200 mumol/kg MnCl2, liver T1 was decreased by 48%, whereas tumor T1 decreased by only 9%. On spin-echo MR images, the signal-to-noise ratio in liver increased by 54%; the contrast-to-noise ratio in tumor, by 375%. The T1 of pancreas, kidney, and heart decreased by 8%, 23%, and 13%, respectively. At subjective assessment, the signal intensity of the upper gastrointestinal tract was reduced, likely because of the high concentration of manganese in the lumen, and delineation of the intestine from other abdominal structures was improved. These results indicate that orally administered MnCl2 causes substantial, reproducible, and tissue-specific enhancement of liver. Because enhancement of tumor was minimal, orally administered MnCl2 may potentially be used to improve detection of hepatic tumors.

Administration, Oral↗
PubMed1993

Cell death and regeneration of renal proximal tubular cells in rats with subchronic cadmium intoxication.

Male Sprague-Dawley rats were injected subcutaneously with 0.6 mg cadmium (Cd)/kg/day for 8 wk. The subsequent changes in renal proximal tubules were studied histologically, histochemically, and ultrastructurally. The urinary and tissue Cd concentrations were determined by atomic absorption spectrophotometry. After 4 wk of exposure, apoptosis was observed predominantly in segment S3 along with epithelial regeneration in the affected tubules, and these changes gradually became more pronounced as the experimental period was prolonged. The apoptotic cells were shed into the lumen and were found to contain a large quantity of Cd. Apoptotic cells were counted in paraffin sections after various periods of exposure to Cd. Nuclear bromodeoxyuridine uptake, mitotic count, and nuclear density were used as indicators of tubular regeneration. A correlation was found between the numerical increase of apoptotic cells and the rate of urinary Cd excretion, and the rate of increase in the tissue Cd concentration had a tendency to reduce after 4 wk as the rate of urinary Cd increased. These observations suggest that apoptosis might be helpful for the efficient excretion of Cd into urine. Progressive increases in the preceding indicators of regeneration were observed. From our results, it appears that Cd-induced tubular damage, i.e., cell deletion due to apoptosis, is reversible as a result of marked epithelial regeneration. On the basis of these histological changes, the critical concentration of Cd required to produce renal tubular damage was estimated to be 600 micrograms/g dry tissue.

Animals↗
PubMed1992

[Percutaneous transluminal angioplasty for stenotic dialysis arterio-venous fistulas].

From December 1982 to January 1991, we performed fistulography on 40 patients who complained functional failure of arterio-venous dialysis fistula. And percutaneous transluminal angioplasty (PTA) was attempted on 15 patients (19 times) who revealed marked fistula stenosis. Initial successful rate was 78.9% and patency rate was 56.2% in the first 6 months. (75% in the first 6 months when angioplasty was initially successful). We describe the method of fistulography and PTA for stenotic dialysis fistulas, and evaluate the usefulness of PTA. And also we introduce our attempts for improving the initial successful rate and patency rate. In conclusion, when dialysis arterio-venous fistula is stenotic but not occlusive, PTA should be considered first before surgical treatment is done.

Adult↗
PubMed1992

Bladder tumor staging: comparison of conventional and gadolinium-enhanced dynamic MR imaging and CT.

With computed tomography (CT) and unenhanced magnetic resonance (MR) imaging, stage pT3b extravesical extension and beyond can be diagnosed, but tumors confined to the bladder wall (stages pT1-pT3a) are poorly delineated. To determine whether visualization of such tumors could be improved with gadolinium-enhanced MR imaging, dynamic breath-hold T1-weighted MR images were obtained after intravenous infusion of 0.1 mmol/kg gadopentetate dimeglumine in 79 patients (86 tumors). Conventional MR images, CT scans, and histologic correlation were available in all cases. With dynamic gadolinium-enhanced MR imaging, the mucosa could be distinguished from the muscular layers of the bladder wall. Staging accuracy with this technique was 85% (73 of 86), which was significantly better than with CT (55%; 47 of 86) (P < .005) or conventional MR imaging (58%; 50 of 86) (P < .05). The accuracy of staging the intramural extent (pT1-pT3a) of bladder tumors was thus improved with gadolinium-enhanced dynamic MR imaging.

Adult↗
PubMed1991

Efficacy of gadolinium-diethylenetriaminepentaacetic acid-enhanced magnetic resonance imaging for differentiation between superficial and muscle-invasive tumor of the bladder: a comparative study with computerized tomography and transurethral ultrasonography.

Gadolinium-labeled diethylenetriaminepentaacetic acid (Gd-DTPA)-enhanced magnetic resonance imaging (MRI) was evaluated in an effort to clarify whether MRI could replace or be proved to be superior to computerized tomography (CT) and/or transurethral ultrasonography. A total of 57 bladder cancer patients was evaluated. MRI was performed with a superconducting magnet operating at 1.5 Tesla. The images acquired were multisections, having a fast spin-echo pulse sequence of less than a 14-second breath holding. Serial scans were performed before and immediately after Gd-DTPA venous injection. The findings on different imaging techniques were compared with the histological stagings. A proper diagnosis was made in 42 of 57 cases (73.7%) by Gd-DTPA-enhanced MRI, in 27 of 57 (47.4%) by CT and in 31 of 57 (54.4%) by transurethral ultrasonography when comparing the histological findings. The sensitivity and specificity for differentiating superficial and muscle-invasive tumor of each imaging method were, respectively, 96.2 and 83.3% in Gd-DTPA-enhanced MRI, 96.0 and 58.3% in CT, and 88.0 and 66.7% in transurethral ultrasonography. These data suggest that the staging of bladder cancer by Gd-DTPA-enhanced MRI appears to be superior and more accurate than the staging obtained by CT and transurethral ultrasonography.

Adult↗
PubMed1991

Pathological study on beagles after long-term oral administration of cadmium.

Histopathological, histochemical, and electron microscopic examinations were performed on beagles after a long-term oral cadmium (Cd) administration of greater than 8 years. Although renal atrophy was remarkable in groups receiving doses of 50 and 100 mg/kg body weight/day, bone lesions could not be demonstrated by roentgenological and histopathologic examination. It was noticed that concomitant regeneration or recovery and cell death of the epithelium occurred in the proximal convoluted tubules. The cell death was consistent with apoptosis, a special feature of cell death, which was shown to play a major part in the tubular damage of cadmium by electron microscopic examination. Fatty degeneration of the pars recta tubules was seen to show dose-dependence. The intrarenal cadmium was localized predominantly in the cytoplasm of the proximal tubular epithelium by histochemical and ultracentrifugal cell fractionation examinations. Although no remarkable changes were found in the other organs, aggregates of siderophages in the liver and focal hemorrhage in the spleen, known as spontaneous lesions, might be related to Cd intoxication. In conclusion, the present study revealed that no bone lesions occur with Cd administration in adult beagles in spite of long-term administration. An excessive cell death to regeneration or recovery in the proximal tubules might result in the renal cortical atrophy. No remarkable changes were seen in the glomeruli and distal nephrons, which were in good agreement with Cd distribution.

Administration, Oral↗
PubMed1990

Multiple primary cancers in a case of chronic arsenic poisoning--an autopsy report.

This is an autopsy report of multiple primary cancers observed in a patient who had clinically been diagnosed as chronic arsenic poisoning. An 88-year-old man, non-smoker, had worked in an arsenic mine for 6 years from the age of 47. He had undergone operations for Bowen's disease and gastric cancer at ages 80 and 86, respectively. At autopsy, squamous cell carcinoma of the lung and a polypoid lesion in the piriform recess were found. Furthermore, microscopic examination revealed latent prostatic adenocarcinoma and oncocytoma in the kidney. The polypoid lesion of the piriform recess appeared to originate from the duct of the minor salivary gland in the pharynx, showing an adenoid cystic carcinoma-like pattern with squamous cell carcinoma in part. The cause of death was thought to be respiratory failure due to bronchopneumonia and pulmonary edema as well as hydrothorax, and chronic heart failure following ischemic heart disease. Bowen's disease was followed by four internal malignant tumors, even though the etiological relation between these cancers and arsenic is not clear.

Adenocarcinoma↗
PubMed1990

[Imaging diagnosis of genitourinary tract tumors].

Recent advance of imaging technique have brought great advantages for management of genitourinary tract tumors. We described few examples of changes in this field from our experience. Many asymptomatic masses are discovered in the kidney and adrenal gland associated with wide clinical application of CT and US. In the kidney, the greater part of incidental masses are renal cell carcinomas (RCC) and the rate of such cases has been increasing. When small RCC is diagnosed without any clinical symptoms, better survival would be expected. Many adrenal incidental mass are also discovered by routine use of CT for abdominal workup. Since greater part of these masses are benign nonfunctioning adenomas, correct diagnosis should be made in order to avoid inappropriate surgery. Rapid development of MR also resulted in some changes in the diagnosis of urinary tract tumors. However, MR cannot be used as a screening method. For staging of RCC, intravascular or adjacent organ invasion was well determined with MR compared with CT. Differentiation of adrenal carcinomas from nonfunctioning adenomas is suggested by the difference of signal intensity on T2 weighted images. Fast spin echo scan with GD-DTPA enhancement is new MRI technique separating bladder mucosal layer from muscle layer as hyper-intensity area. Using this method, diagnostic accuracy of deep muscle invasion for bladder tumor would be improved.

Adrenal Gland Neoplasms↗
PubMed1989

[Magnetic resonance imaging of bladder tumors: superiority of serial "Fast SE" assisted by Gd-DTPA in tumor staging].

Eighteen cases with bladder tumors were examined by means of superconducting MRI. Sequences used were spin echo (TR/TE (msec) = 500/20 as T1WI (weighted image) and 1500/80 as T2WI) and serial "fast spin echo (fast SE)" pre/post Gd-DTPA administration. "Fast SE" was a new technique offering a distinct T1WI (TR/TE = 100/14, utilizing a 14 second breath hold). Slice thickness of "fast SE" was 10 mm and slice plane was selected perpendicular to the tumor base to detect the extent of invasion. Serial scan of "fast SE" was performed before and immediately after 0.1 mmol/kg Gd administration. Scanning was completed before the bladder was opacified by Gd. Tumor and normal mucosa were both markedly enhanced whereas the surrounding muscle layer remained hypointense. On delayed scan, the elevated character of the tumor was outlined by opacified urine but the distinction between the mucosa and the muscle layer became unclear. Total cystectomy (TC) was performed in 6 of 18 cases and pathological tumor extension was correlated with MR findings. Transurethral resection (TUR) was performed in the remaining 12 patients, and the tumor extension was assessed by follow-up biopsy after TUR. Intact liner hypointensity indicated superficial lesions (= less than pT2), while disruption of the linear hypointensity corresponded pathologically to deep muscle invasion (= greater than pT3a). Accuracy of serial "fast SE" in tumor staging was 94% (17/18). Serial "fast SE" allowed the distinction of superficial from invasive tumors more accurately than conventional studies, and therefore assisted in choosing the correct operative method.

Adult↗
PubMed1989

Diffuse pleural rhabdomyosarcoma with persistent pleural effusion.

A unique case of embryonal rhabdomyosarcoma arising at the left pleura of a 7-year-old Japanese girl is reported. The present case was characterized by persistent pleural effusion, and the malignant cells incidentally found in it were the first diagnostic clue. The tumor showed a rare growth pattern involving diffuse thickening of the parietal pleura. Biopsy of the thickened parietal pleura upon thoracotomy revealed embryonal rhabdomyosarcoma largely composed of immature mesenchymal cells. Immunohistochemical demonstration of creatinine phosphokinase-MM was most helpful among several types of immunostain for the histopathological diagnosis. Ultrastructurally, thin filaments with primitive Z bands could be seen in some tumor cells. Intensive clinical examination revealed only diffuse thickening of the parietal pleura, which was reduced by chemotherapy. This is the first documented case of rhabdomyosarcoma arising at the pleura. Previous reports of rhabdomyosarcoma arising at unusual sites are reviewed and the histogenesis of this tumor is briefly discussed.

Child↗