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Biomedical subjects

S Ishiguro

Publications and source records attributed to S Ishiguro.

At least 163 records · Page 9Linked to original sources
PubMed1995

Liver with hypoechoic nodular pattern as a risk factor for hepatocellular carcinoma.

BACKGROUND/AIMS: Ultrasonography should be used for screening of hepatocellular carcinoma, but there are few reports on the relationship between liver ultrasonographic findings and the development of hepatocellular carcinoma (HCC). Using prospective follow-up studies, we examined the role of liver with a hypoechoic nodular pattern as a high-risk factor in HCC. METHODS: The study was performed by follow-up on 593 patients with chronic liver disease recorded at our hospital. The ultrasonographic pattern of the liver parenchyma was classified either as a small or large hypoechoic nodular pattern or as a nonnodular pattern. Patients were followed up from the time of initial ultrasonographic examination (1985-1987) until January 1, 1991. RESULTS: During the follow-up period (average, 4.2 years, range, 0.3-6.0 years), 62 patients were found to have HCC (12%). Patients whose livers showed small or large hypoechoic nodular pattern had a significantly higher risk of HCC than did patients whose livers showed a nonnodular pattern (rate ratios were 14.0 and 20.0, respectively, adjusted for age, sex, hepatitis virus markers, ICG R15, alpha-fetoprotein concentration, and ultrasonographic pattern of the liver). CONCLUSIONS: Liver showing a hypoechoic nodular pattern is a major risk factor in HCC.

Adult↗
PubMed1995

Congenital hypomyelination neuropathy: decreased expression of the P2 protein in peripheral nerve with normal DNA sequence of the coding region.

Congenital hypomyelination neuropathy (Lyon type) is characterized by a non-progressive clinical course and a histopathological formation of atypical onion-bulb. We have studied the immunohistochemical expression of the major peripheral myelin proteins including P0 protein, myelin basic protein (MBP) and P2 protein in three such patients. No significant difference was observed between the patients and the controls, as to the P0 and MBP staining. In contrast, P2 protein antiserum scarcely stained the patients' nerve fibers except for a few scattered adequately myelinated fibers. Assuming the pathogenetic contribution of the extremely decreased P2 protein to the disease, we investigated P2 protein gene by sequencing all coding regions but failed to detect any change in the nucleotide sequence. Further investigation including the analysis of promoter region of P2 protein gene is needed to elucidate the mechanism of congenital hypomyelination neuropathy.

Base Sequence↗
PubMed1995

Cloning and sequence analysis of genes for cyclophilin from Arabidopsis thaliana.

Two genomic DNA clones encoding cyclophilin (CyP) from Arabidopsis thaliana were isolated. The deduced protein products of these genes appeared to be cytosol-localized isoforms given the absence of a specific presequence for targeting to cellular compartments. Thus, multiple CyPs may exist and function in the cytosol of Arabidopsis thaliana.

Amino Acid Isomerases↗
PubMed1995

Adenomyoepithelioma of the lung.

A 66-year-old man with an extremely rare neoplasm of the lung, adenomyoepithelioma, is described. The tumor was a well-circumscribed lesion that showed solid, glandular, and papillary growth patterns and was composed of two types of cells, inner epithelial cells and outer myoepithelial cells. This bidirectional differentiation was confirmed immunohistochemically. The inner epithelial cells were positive for carcinoembryonic antigen and epithelial membrane antigen, while the outer myoepithelial cells were S-100 protein-positive. Electron microscopically, the tumor was characterized by a large amount of microfilaments in the cytoplasm and layers of basement membrane-like material in the intercellular spaces. Some glycogen granules were detected.

Adenomyoma↗
PubMed1995

Infrequent replication errors at microsatellite loci in tumors of patients with multiple primary cancers of the esophagus and various other tissues.

Patients with esophageal cancer are at high risk of developing other primary tumors, especially squamous cell carcinoma in the head and neck. Heavy smoking and excessive consumption of alcohol are considered to be crucial environmental risk-factors for development of these multiple primary cancers. To investigate whether any genetic background, such as defects in the DNA-mismatch repair system, may influence the development of these multiple primary tumors, we examined replication errors (RER) at six microsatellite loci in DNAs of 46 tumors from 33 patients who had developed primary cancers in various tissues in addition to the esophagus. RER(+) (RER-positive) phenotype was observed in three tumors in two patients of the 33 patients examined. Our results suggested that development of multiple primary tumors in these patients would not be affected by an abnormality in the DNA repair system(s) detected as the RER phenotype. However, it is noteworthy that a single patient who developed multiple cancers revealed RER(+) phenotypes at multiple microsatellite loci in both tumors, indicating that a defect in the DNA repair gene(s) may have played an important role in the development of the tumors in this patient.

Adenocarcinoma↗
PubMed1995

Mechanisms of the enhanced contractile response to a low concentration of phorbol 12,13-dibutyrate in thoracic aorta isolated from rats with dietary magnesium deficiency.

The mechanisms underlying the enhanced contractile response to phorbol 12,13-dibutyrate (PDBu) were examined in de-endothelialized thoracic aortas isolated from rats with dietary magnesium (Mg) deficiency. PDBu (1.0 nM)-induced contractions were significantly larger in Mg-deficient rats than in the controls. The contraction was completely inhibited by nifedipine, removal of external Ca2+ or by l-(5-isoquinolinesulfonyl)-2-methylpiperazine (H7). PDBu (1.0 nM) and phorbol 12-myristate 13-acetate (1.0 microM) significantly decreased the KD value and increased the Bmax for the binding of [3H]PN200-110 to the aortas. The degree of the decrease in the KD value was significantly greater in Mg-deficient rats than in the controls. The PDBu-induced decrease in the KD value was abolished by H7. These results suggest that activation of protein kinase C by phorbol esters may participate in the activation of L-type Ca2+ channels, which increases both the affinity of [3H]PN200-110 binding and the magnitude of the external Ca(2+)-dependent contraction. Dietary Mg-deficiency may enhance these processes.

Animals↗
PubMed1995

Alteration of glutamine concentration in the vitreous humor in patients with proliferative vitreoretinopathy.

Using sensitive high performance liquid chromatography (HPLC), we measured free amino acid concentrations in the undiluted vitreous samples of patients who underwent pars plana vitrectomy for treatment of idiopathic preretinal macular fibrosis (PMF, n = 8), proliferative diabetic retinopathy (PDR, n = 12), or proliferative vitreoretinopathy (PVR, n = 15) to investigate the effect of vitreoretinal diseases on the concentrations of free amino acids in human vitreous. The most abundant amino acid was glutamine in all of three groups. Other major amino acids commonly found in the human vitreous samples were serine, alanine, arginine, valine, and lysine. Patients with PDR and PVR showed significantly lower concentrations of glutamine in vitreous (PDR: 655 +/- 230 nmoles/ml, PVR: 683 +/- 302 nmoles/ml) than those with PMF (PMF: 975 +/- 247 nmoles/ml; significance level, PDR: p < 0.01, PVR: p < 0.05). In addition, patients with grade D PVR showed significantly lower concentration of glutamine (357 +/- 117 nmoles/ml) than those with grade C PVR (802 +/- 256 nmoles/ml, p < 0.005), or PMF (p < 0.005). These results suggest two possible mechanisms for the alteration of intravitreal glutamine in the pathologic conditions. The first possibility is a reduced amount of supply of glutamine that is normally transported or released from surrounding tissues into vitreous humor. The second possibility is an increased amount of uptake and utilization of glutamine by cells within vitreous and pathologic tissues.

Adolescent↗
PubMed1995

Antiangiogenic substance(s) in a tumor cell line with low metastatic potential originating from the BALB/c mouse liver.

Two cell lines were established from liver cells (BALB/c mouse) exposed to benzo(a)pyrene: one was highly metastatic (G-5) and the other poorly metastatic (G-1) to the lung when subcutaneously implanted. However, there was no difference in lung colonization between G-1 and G-5 cells when they were intravenously injected. When G-1 cells were subcutaneously inoculated on one side of the back of mice followed by a challenge on the other side with G-5 cells 10 days later, the growth of the latter tumor was inhibited and the number of metastatic nodules in the lung was reduced. The functional vascular volume of G-1 tumor was less than the G-5 one. In mice bearing G-1 tumors, the neovascularization of intradermally inoculated G-5 cells was reduced. The conditioned medium from G-1 culture contained an inhibitory activity on the growth of endothelial cells from calf pulmonary artery. The inhibitory substance(s) was heat-stable, trichloroacetic acid-soluble, nondialyzable and resistant to various proteinases. The present results imply that G-1 cells produce an antiangiogenic substance(s), probably a polysaccharide(s), which inhibits the angiogenesis required for growth and metastasis of the G-5 tumor.

Animals↗
PubMed1995

[Preoperative neoadjuvant chemotherapy with a combination of 5-fluorouracil, adriamycin and cisplatin (FAP) for advanced esophageal cancer invading trachea or main bronchus].

Conventional irradiation and systemic chemotherapy is scarcely effective for advanced esophageal cancer invading trachea or main bronchus. Therefore, to reduce the area of invasion and suppress distant metastasis, we have preoperatively treated 4 patients suffering from advanced esophageal cancer invading the trachea or main bronchus by neoadjuvant chemotherapy (FAP) as follows: 2 times every 4 weeks, CDDP 100 mg and ADR 50 mg on day 1 and continuous infusion of 5-FU 1,000 mg/day for 7 days. The response rate (PR) was 75% (3/4). In 2 of 4 patients (50%), no cancer cells except broad fibrosis were detected histologically in the region of the trachea or main bronchus suspected to be invaded. There was no severe complication. This FAP regimen is suspected to be useful chemotherapy for advanced esophageal cancer.

Aged↗
PubMed1995

[A case of a single coronary artery in the presence of coexistent atherosclerotic coronary artery disease].

A 57-year-old female was admitted with 6-month history of effort angina. Ascending aortography showed that the right coronary artery (RCA) did not originate from the right coronary sinus. Coronary arteriography showed that the circumflex branch (CX) continued beyond the crux into the right atrioventricular groove to supply marginal branches to the right ventricle, that is, RCA originated from the CX at the crux. RCA had the 75% stenosis near the crux. Left anterior descending branch (LAD) also had 90% stenosis at segment 6. She did not have the additional congenital cardiac anomalies, and underwent coronary artery bypass grafting to LAD and RCA without problem.

Angina Pectoris↗
PubMed1994

Characterization of a cDNA encoding a novel DNA-binding protein, SPF1, that recognizes SP8 sequences in the 5' upstream regions of genes coding for sporamin and beta-amylase from sweet potato.

We isolated a cDNA encoding a DNA-binding protein, SPF1, of sweet potato that binds to the SP8a (ACTGTGTA) and SP8b (TACTATT) sequences present in the 5' upstream regions of three different genes coding for sporamin and beta-amylase of tuberous roots. SPF1 comprises 549 amino acids and is enriched in both basic and acidic residues. The amino acid sequence of SPF1 shows no significant homology to any known protein sequences, suggesting that it may represent a new class of DNA-binding protein. Binding studies with 35S-labeled SPF1, synthesized in vitro, and synthetic DNA fragments indicated that, although SPF1 binds to both the SP8a and SP8b sequences, it binds much more strongly to SP8a than to SP8b. SPF1 bound to the SP8a sequence as a monomer. The DNA-binding domain of SPF1 was localized within the C-terminal half of this protein, and a 162-amino acid fragment of SPF1 (Met310-Arg472) showed DNA-binding activity with no change in target sequence specificity. This fragment contains a region enriched in basic amino acids adjacent to a highly acidic stretch. A sequence which is highly homologous to a 40-amino acid sequence in the basic region of the DNA-binding domain is duplicated in the N-terminal part of SPF1. The gene coding for SPF1 is present in one or a few copies per haploid genome and the SPF1 mRNA was detected in leaves, stems and tuberous roots of the sweet potato, in addition to petioles. The level of SPF1 mRNA in the petioles decreased when leaf-petiole cuttings were treated with sucrose to induce accumulation of sporamin and beta-amylase mRNAs.

Amino Acid Sequence↗
PubMed1994

Cytologic examination of pancreatic juice for differential diagnosis of benign and malignant mucin-producing tumors of the pancreas.

BACKGROUND: A new clinical type of pancreatic tumor, the mucin-producing tumor, has been recognized recently. However, it is not always easy to distinguish benign from malignant tumors preoperatively. In this study, three different methods of differentiating mucin-producing tumors of the pancreas were compared. METHODS: Endoscopic ultrasonography, endoscopic retrograde pancreatography, and cytologic examination of pancreatic juice were performed in 14 patients who had mucin-producing pancreatic tumors (11 carcinomas and 3 adenomas). Pancreatic juice was collected endoscopically without papillotomy. RESULTS: The sensitivity, specificity, and overall accuracy of endoscopic ultrasonography were 82%, 90%, and 79%, respectively; those of endoscopic retrograde pancreatography were 91%, 91%, and 86%; and those of cytologic examination were 91%, 100%, and 93%. CONCLUSION: Cytologic examination of pancreatic juice was the best of these three methods for differentiating benign from malignant mucin-producing pancreatic tumors.

Adenocarcinoma, Mucinous↗
PubMed1994

Rapidly growing thyroid carcinoma during pregnancy.

We experienced two cases of papillary carcinoma of the thyroid during pregnancy. The thyroid carcinomas grew rapidly in early pregnancy. We speculate that human chorionic gonadotropin plays an important role in the rapid growth of thyroid carcinoma during pregnancy.

Adult↗
PubMed1994

Diagnosis of colorectal tumors by the endoscopic Congo red-methylene blue test.

The endoscopic Congo red-methylene blue test was performed on 51 tumors of the large intestine. Results revealed that colorectal adenocarcinomas and adenomas bleached the Congo red and methylene blue sprayed over their surface and so appeared in sharp contrast to the bluish red mucosa of unaffected areas. No bleaching of the dyes was observed on the surface of non-neoplastic polyps. Moderately differentiated adenocarcinomas, submucosal or advanced cancers, and adenomas with severe atypia bleached the dyes most frequently. Thus this test facilitates early detection of colorectal tumors.

Adenocarcinoma↗
PubMed1994

Analysis of factors affecting uptake of Tc-99m Sn-N-pyridoxyl-5-methyltryptophan by hepatocellular carcinoma.

We performed Tc-99m PMT imaging in 176 patients with HCC and evaluated factors affecting 99mTc-PMT uptake by HCC with a logistic model. The probability of HCC showing increase in uptake of the radioisotope was 104.6 times higher in patients with the Ed I type than in those with the Ed III type and 12.1 times higher in patients with a tumor diameter of 5.0-7.9 cm than in those with a tumor diameter of 2.0-5.0 cm. Among the other variables, the serum AFP level and sex were suggested to have effects similar to those of the tumor size on Tc-99m PMT uptake by HCC. The grade of morphological differentiation of the tumor was therefore most markedly related to Tc-99m PMT uptake.

Age Factors↗