Biomedical subjects

A Tanimoto

Publications and source records attributed to A Tanimoto.

At least 55 records · Page 3Linked to original sources

PubMed1998

Small solid renal lesions: usefulness of power Doppler US.

PURPOSE: To evaluate whether the vascular pattern at power Doppler ultrasonography (US) improves diagnostic accuracy in small solid renal lesions over that at gray-scale US. MATERIALS AND METHODS: Gray-scale and power Doppler US were performed prospectively in 64 small (1.5-3.0-cm-diameter) solid renal lesions (26 renal cell carcinomas [RCCs], 34 angiomyolipomas, two oncocytomas, two pseudotumors). At gray-scale US, echogenicity and homogeneity of the lesion, an anechoic rim, intratumoral cysts, shadowing, or a central scar were sought. At power Doppler US, the vascular distribution was divided into four patterns. RESULTS: Findings at gray-scale US included an anechoic rim or intratumoral cysts in 20 of 26 RCCs (77%) and the two oncocytomas. Shadowing was seen in seven of 34 angiomyolipomas (21%). Echogenicity, homogeneity, and a central scar were not pathognomonic. At power Doppler US, pattern 3 (peripheral) or 4 (mixed penetrating and peripheral) was seen in all RCCs, seven of 34 angiomyolipomas, and the two oncocytomas. Pattern 1 (intratumoral focal) or 2 (penetrating) was seen in 27 angiomyolipomas. Pattern 1 or 2 was characteristic of angiomyolipoma. The rate of correct diagnosis was significantly increased with combined US (78%) as compared to that with gray-scale (42%) or power Doppler (45%) US alone. CONCLUSION: The vascular distribution at power Doppler US could add important information to gray-scale US findings for differential diagnosis of small solid renal lesions.

Adenoma, Oxyphilic↗

PubMed1997

Hepatitis C virus NS5A protein is phosphorylated in vitro by a stably bound protein kinase from HeLa cells and by cAMP-dependent protein kinase A-alpha catalytic subunit.

Hepatitis C virus (HCV) has a positive-strand RNA genome that codes for a polyprotein precursor, which is processed co- and post-translationally by cellular and viral proteinases into three structural and at least six non-structural (NS) proteins. The NS5A protein, expressed in mammalian cells, exists in two phosphorylated forms of 56-kDa and 58-kDa. In this study, we provide evidence for a stable association between NS5A and a protein kinase from HeLa cells and hepatocellular carcinoma (HepG2) cells by co-immunoprecipitation and by affinity to immobilized glutathione-S-transferase (GST)-NS5A fusion protein produced in E. coli. This protein kinase could phosphorylate in vitro the native NS5A on serine residues, (GST)-NS5A, histone H1, and casein as substrates. In addition, the GST-NS5A was also phosphorylated in vitro by the cAMP-dependent protein kinase A-alpha catalytic subunit.

Binding Sites↗

PubMed1997

The amino terminal deletion mutants of hepatitis C virus nonstructural protein NS5A function as transcriptional activators in yeast.

To investigate the biological function of hepatitis C virus (HCV)-NS5A, the NS5A was fused at its N-terminus with the DNA binding domain (DBD) of yeast transcriptional activator GAL4 (GAL4-DBD). The GAL4-DBD alone had no transcriptional activation function. However, a mutant of the GAL4-DBD/NS5A fusion protein, in which 129 amino acid residues were deleted from the N-terminus of NS5A, exhibited strong transcriptional activation in yeast cells, bearing the Escherichia coli lacZ reporter gene encoding the beta-galactosidase under the transcriptional control of GAL4 promoter and TATA box. Further mutational analysis of NS5A revealed that the region between the amino acid residues 130 to 352 were critical for optimal level of transactivation. This region includes two acidic domains and one proline-rich region which have been shown to be involved in the function of several transcriptional activators.

Gene Expression Regulation, Viral↗

PubMed1997

Apoptosis induced by cadmium.

Cell death resulting from cadmium (Cd) intoxication has been confirmed to occur through apoptosis by morphological and biochemical studies. However it is still not clear whether Cd itself or metallothionein (MT) induced by Cd is the major factor responsible for the apoptosis. Although apoptosis is inducible by exposure of cells to various stimuli, the common pathway involved is generally accepted to be activation of endonucleases that induce internucleosomal cleavage of DNA, resulting in the 'ladder' formation observed upon agarose gel electrophoresis and the chromatin condensation seen by electron microscopy. Cd does not seem to activate the endonuclease in vitro. However, Cd itself can be associated with apoptosis through indirect oxidative stress by inhibition of antioxidant enzymes and possible interaction with zinc finger protein. In addition to the direct effect of Cd, MT appears to play dual roles in apoptosis induction: one as a Cd carrier by which Cd accumulates in the nucleus, and the other as an inhibitor of zinc finger proteins, which include transcriptional factors related to apoptosis such as the product of the apoptosis resistance gene A20. In this review, we demonstrated that the mode of cell death following Cd exposure is associated with intracellular movement of Cd and MT. A possible mechanism for Cd-induced apoptosis is also discussed.

Journal Article↗

PubMed1997

Angiomyolipoma: imaging findings in lesions with minimal fat.

PURPOSE: To investigate a method of diagnosing angiomyolipoma that contains minimal fat. MATERIALS AND METHODS: In six cases of angiomyolipoma with minimal fat, the attenuation on contrast material-enhanced and unenhanced computed tomographic (CT) images, the echogenicity on sonograms, the signal intensity on T2-weighted magnetic resonance (MR) images, and the gross configuration of the lesion were retrospectively analyzed. In 100 cases of renal cell carcinoma, the same parameters were analyzed, and results were compared with those of angiomyolipoma. RESULTS: When compared with the surrounding renal parenchyma, all six angiomyolipomas showed homogeneously high attenuation on unenhanced CT images, homogeneous enhancement on contrast-enhanced CT images, and homogeneous isoechogenicity on sonograms. Of the five angiomyolipomas examined with MR imaging, four were hypointense and one was isointense on T2-weighted images. All six angiomyolipomas protruded from the renal margin. None of the 100 renal cell carcinomas showed homogeneously high attenuation on unenhanced CT images, homogeneous enhancement on contrast-enhanced CT images, or homogeneous isoechogenicity on sonograms. CONCLUSION: In the kidney, homogeneously high attenuation on unenhanced CT images, homogeneous enhancement on contrast-enhanced CT images, and homogeneous isoechogenicity on sonograms are suggestive of angiomyolipoma that contains abundant muscle and minimal fat.

Adipose Tissue↗

PubMed1996

Determination of arsenic in blood and stomach contents by inductively coupled plasma/mass spectrometry (ICP/MS).

Inductively coupled plasma/mass spectrometry (ICP/MS) was used and evaluated for the practical analysis of the arsenic content of body fluid samples without ashing. The calibration curve for arsenic in blood solution was shown to have good sensitivity, linearity and reproducibility. Blood obtained from normal volunteers was determined by ICP/MS, and compared with that determined by atomic absorption spectrometry (AAS). The arsenic contents determined by ICP/MS showed a linear correlation with that determined by AAS. Furthermore, arsenic was determined in the blood and supernatant of stomach contents obtained from a suicide autopsy case resulting from ingestion of an arsenic compound. It was therefore concluded that ICP/MS could be used rapidly and conveniently in the field of forensic toxicology in acute metal poisoning cases.

Arsenic↗

PubMed1996

Apoptosis of human kidney 293 cells is promoted by polymerized cadmium-metallothionein.

Transformed human kidney cells (293 cells) exposed to 12.5 to 37.5 microM CdCl(2) showed apoptosis as confirmed by characteristic electron microscopic features, a ladder on gel electrophoresis of extracted DNA, and fragmentation of nucleosomes as detected by enzyme linked immunosorbent assay (ELISA). Higher concentrations of Cd were less effective in inducing apoptosis. Furthermore, addition of the protein extract from the serum-free medium used for Cd-exposure promoted apoptosis exhibiting the same features as that after Cd-exposure. The apoptosis induced by the protein was dose-dependent. The molecular weight of the protein (Cd-protein) was shown to be 40 kDa by gel filtration. Two-dimensional electrophoresis revealed the Cd-protein as a single spot with a molecular weight of 6 kDa and pI of 4.5. Competitive ELISA showed that the Cd-protein reacted with anti-metallothionein antibody. The present findings suggest that apoptosis is induced not only by Cd itself but also by polymerized metallothionein molecules (MT) released from cells into the medium.

Animals↗

PubMed1996

Syringomyelia associated with Hajdu-Cheney syndrome: case report.

OBJECTIVE AND IMPORTANCE: Hajdu-Cheney syndrome is a rare idiopathic bone disease based on a generalized bone dysplasia accompanied by acro-osteolysis. We describe a surgical case of this syndrome that was accompanied by neurological signs associated with cervical syringomyelia. CLINICAL PRESENTATION: A 41-year-old woman was referred to our hospital with mild quadriparesis and sensory disturbance resulting from a car accident. There was a neck injury. She showed almost all of the major characteristic clinical features and roentgenographic findings of Hajdu-Cheney syndrome with syringomyelia. INTERVENTION: Surgical treatment was indicated because of the progressive neurological deficits. Foramen magnum decompression and C1 laminectomy were performed, and the dura was exposed. The dura was opened at the area of the foramen magnum and C1. The occipitocervical posterior fusion was carried out with an iliac bone graft and titanium wires. CONCLUSION: Postoperatively, quadriparesis and sensory disturbance improved and the patient showed improved ambulation. Magnetic resonance imaging disclosed the well-decompressed foramen magnum. The syringomyelia disappeared in the segmental area of C2 and was decreased in the segmental areas of C5-T6. The treatment of this syndrome is symptomatic. In this patient, magnetic resonance imaging disclosed compression of the brain stem by basilar invagination and platybasia, disturbance of cerebrospinal fluid flow at the level of the foramen magnum, and syringomyelia. It was suspected that the obstruction of cerebrospinal fluid flow at the level of foramen magnum caused the cervical syringomyelia. However, the long-term prognosis remains uncertain. Follow-up is necessary to assess the final result of the treatment.

Adult↗

PubMed1996

Endometrial stromal sarcoma of the uterus with rhabdoid features.

A case of endometrial stromal sarcoma of the uterus with rhabdoid features, occurring in a 57 year old woman is reported. Electron microscopy and immunohistochemistry revealed that the rhabdoid cells contained intermediate filaments which were positive for vimentin, cytokeratin, alpha-smooth muscle actin, and muscle specific actin, but not for myoglobin and desmin. This indicated that the tumor in this case differed somewhat from the three rhabdoid tumors and an endometrial stromal sarcoma with rhabdoid differentiation previously reported and that, therefore, these tumors were heterogeneous.

Biomarkers, Tumor↗

PubMed1996

[Early phase II trial of Gd-BOPTA (E7155) for the MR imaging of liver tumors].

A clinical early phase II trial of Gd-BOPTA (E7155) was performed to assess its safety and usefulness for the detection of the hepatic lesions. Seventy-nine patients were assigned to three groups; a low dose group (0.025 mmol/kg), medium dose group (0.05 mmol/kg) and high dose group (0.1 mmol/kg). In terms of safety, Gd-BOPTA was assessed as "safe" in 76 patients and "somewhat questionable" in three patients including one with nausea and two with obvious changes in laboratory findings. No severe adverse reaction was experienced. In terms of the usefulness of dynamic study, the percentage of more than "useful" in the high dose group, medium dose group and low dose group were 100%, 100% and 76.9%, respectively. The result of "usefulness" of early and delayed post-contrast images showed more than "useful" in over 60% of cases. These results indicated that both dynamic and post-contrast early and delayed images were useful for the evaluation of liver tumors, suggesting that this contrast agent would have characteristics of both extracellular and liver-specific contrast agents.

Adolescent↗

PubMed1995

Ovarian mucinous cystadenocarcinoma with sarcoma-like mural nodules.

A rare case of ovarian mucinous cystadenocarcinoma with sarcoma-like mural nodules is reported. Macroscopically, nodular or granular lesions were scattered over the inner surface of a huge, multilocular tumor in the left ovary. The histopathological features were consistent with those of previously documented cases, except significant squamous metaplasia in the present case. The pleomorphic sarcoma-like cells showed a positive reaction for vimentin and alpha-antichymotrypsin but were negative for carcinoembryonic antigen and common epithelial membrane antigen by immunohistochemistry. Electron microscopically, the tumor cells had neither desmosomes nor secretory granules, but they possessed abundant intermediate filaments. Both immunostaining and ultrastructure suggested that the sarcoma-like nodules were derived from reactive proliferation of fibrohistiocytic cells. The fibrohistiocytic reaction seemed to occur in response to hemorrhage, because hemorrhage was reported to be associated with the mural nodules in most of the previous cases as well as ours.

Cystadenocarcinoma, Mucinous↗

PubMed1995

Mild emphysema: a novel method using formalin-fixed lungs for computed tomography and pathological analyses.

We evaluated a novel method of computed tomography (CT) analysis using formalin-fixed lungs of autopsy cases with mild emphysema. Eight formalin-inflated lungs (FILs) obtained at autopsy were examined using CT after draining off the formalin and air inflation with an air pump, and subjected to pathological study including pathological scoring of emphysema and microscopic image analysis (MIA). Satisfactory CT examination was carried out within 5 h of lung fixation. The mean alveolar area determined by MIA correlated highly with the lung volume (r = 0.845) and CT score (r = 0.722). This method is simple compared with conventional polyethylene glycol fixation for CT and enables CT examination of resected lungs without anxiety about biohazards, Mild emphysema can be detected by MIA.

Aged↗

PubMed1995

Immunopathological mechanisms of human T cell lymphotropic virus type 1 (HTLV-I) uveitis. Detection of HTLV-I-infected T cells in the eye and their constitutive cytokine production.

The immunopathology of human T cell lymphotropic virus type 1 (HTLV-I) uveitis was addressed by using T cell clones (TCC) established from the intraocular fluid of patients with HTLV-I uveitis. Proviral DNA of HTLV-I was identified in 55 out of 94 (59%) or 13 out of 36 (36%) TCC from the ocular fluid or the peripheral blood of these patients, respectively. Most of HTLV-I-infected TCC had a CD3+ CD4+ CD8- phenotype. HTLV-I infection on TCC was confirmed by analysis of the viral mRNA, nucleotide sequence, virus-associated proteins, and virus particles. HTLV-I-infected TCC, but not HTLV-I negative TCC, constitutively produced high amounts of IL-6 (1,336 +/- 1,050 pg/ml) and TNF-alpha (289 +/- 237 pg/ml) in the absence of any stimuli. HTLV-I-infected TCC from the ocular lesion also constitutively produced high amounts of IL-1 alpha (12,699 pg/ml), IL-2 (61 pg/ml), IL-3 (428 pg/ml), IL-8 (1,268 pg/ml), IL-10 (28 pg/ml), IFN-gamma (5,095 pg/ml), and GM-CSF (2,886 pg/ml). Hydrocortisone, a drug effective in vivo for the treatment of HTLV-I uveitis, severely depressed cytokine production in vitro in most cases. In summary, the results demonstrated direct evidence of HTLV-I infection of the eye and suggest that cytokines produced by HTLV-I-infected T cells are responsible for the intraocular inflammation in patients with HTLV-I uveitis.

Adult↗

PubMed1995

Expression of the histamine H1 receptor gene in relation to atherosclerosis.

Histamine in serum and arterial tissue contributes to the pathogenesis of atherosclerosis and the formation of coronary artery vasospasm. As the effect of histamine at a given site will be mediated by its specific receptors, we investigated by in situ hybridization and Northern blot analysis the expression and localization of human histamine H1 receptor mRNA in the arterial wall and in cultured human aortic intimal smooth muscle cells (SMC) and immortalized SMC (ISS10) and endothelial cells (SE1). In situ hybridization showed that SMC and endothelial cells expressed H1 receptor mRNA in vivo and that the expression was increased in SMC in the thickened intima of atherosclerotic foci in both the aorta and coronary artery. By Northern blot analysis, we also detected histamine H1 receptor mRNA in cultured SMC, ISS10, and SE1 and found that platelet-derived growth factor stimulated SMC to increase their expression of the mRNA in vitro. These results suggest that up-regulation of histamine H1 receptor expression by platelet-derived growth factor plays an important role in the initiation and progression of cardiovascular diseases.

Aorta↗

PubMed1995

[CT anatomy of the caudate lobe of the liver].

The anatomy of the portal vein branches in the caudate lobe of the liver was studied in 20 patients by double-phase CT arterial portography (DP-CTAP). DP-CTAP provided excellent images of the portal venous system in the first phase and the perfusion defects of intrahepatic tumors in the second phase. From DP-CTAP images of the first phase, a sufficient number of interpolated images were created for a smooth paging display. The ramifying structures of the portal system were traced on the monitor using the tracking ball. This method was found to be very effective and reliable for the anatomical assessment of the caudate lobe. The number and origins of the caudal portal branches were investigated in each case, and the caudate lobe of the liver could be divided into right and left segments.

Humans↗

PubMed1995

Establishment and characterization of immortalized human coronary endothelial cells.

We established an immortalized cell line from endothelial cells derived from a human coronary artery, isolated at autopsy from 76-year-old male, by transfecting the cells with origin-minus simian virus 40 DNA. These cells showed SV40 T antigen in the nuclei and Ulex europaeus I agglutinin and factor VIII-related antigen, as endothelial cell markers, in their cytoplasm. This cell line synthesized prostacyclin, tissue-type plasminogen activator (tPA), and plasminogen activator inhibitor-1 (PAI-1) as well as produced the proform of matrix metalloproteinase 1, which was activated by cultivating the cells with plasminogen. These findings reveal that this immortalized endothelial cell line retains characteristics of human coronary endothelial cells, indicating that this cell line is useful for studying atherogenesis of the coronary artery.

Aged↗

PubMed1995

[Methicillin-resistant Staphylococcus aureus forming the fried egg appearance colonies isolated from a patient with septicemia].

Slower growing and peculiar colonies, "fried egg" appearance, of different sizes were temporally grown on a sheep blood agar plate from a clinical blood sample obtained from a patient with mediastinitis due to infection by methicillin-resistant Staphylococcus aureus (MRSA) following the graft replacement of thoracic aorta. The organisms revealed morphologically characteristic "fried egg" appearance, mainly Gram-positive cocci including some Gram-negative cells and cell-debris, catalase test positive and coagulase test positive as well as having the identical profiles for S. aureus on biochemical examination with VITEK Systems. The rough surfaced cell walls with unequal thickness of the organisms were observed in an electronmicroscope. According to these bacteriological studies, the organisms were identified as a mutant of S. aureus which had many similarities to staphylococcal L-form. Being resistant to oxacillin, instead of methicillin susceptibility test, and possessing a mecA gene, the organisms were confirmed to belong to MRSA. It is likely that this mutant of S. aureus was induced by a long term medication of sulfamethoxazole-trimetoprim, since the patient had been receiving the drug during 5 weeks when the colonies were first detected.

Aged↗

PubMed1995

Combined treatment of probucol with diltiazem regresses atherosclerosis induced by 196 cholesterol diet in rabbit aorta.

To clarify whether probucol, an antioxidant, or diltiazem, a Ca2+ antagonist, favorably affect the regression of established atherosclerosis, rabbits were fed a 1% cholesterol diet for 10 weeks, then a standard diet for an additional 25 weeks (regression period). During the regression period, rabbits were grouped into a saline (S) group (n=8, 1 ml saline/d), a probucol (P) group (n=8, 1000 mg/d probucol), or a probucol and diltiazem (P+D) group (n=8, probucol 1000 mg/d in diet and diltiazem 30 mg/d). We measured cholesterol in serum, lipoprotein fractions, and serum triglyceride or phospholipid concentration and found no significant differences among the three groups at 10, 15, or 35 weeks. After 10 weeks of the atherogenic diet, the ratio of macroscopic atherosclerotic lesions in aortic intima rose to 36.6 + or - 5.6%. After the regression period, the S group developed more atherosclerotic lesions (48.6 + or - 6.4%). The P+D and P groups, however, had decreased scores of 24.3 + or - 5.5% (p<0.05 vs. S) and 32.3 + or - 5.6%, respectively. Moreover, these decreased scores were well correlated with the decrease in aortic tissue lipid compositions, but not the parameters for extracellular matrices. We concluded that P+D or P therapy might be effective in regressing established atherosclerosis by removing lipid contents but not extracellular matrices.

Animals↗