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Biomedical subjects

H Ohtani

Publications and source records attributed to H Ohtani.

At least 145 records · Page 8Linked to original sources
PubMed1998

Reliability of internal jugular vein in oral microvascular reconstruction.

OBJECTIVE: The purpose of this study was to review the reliability of the internal jugular vein when used as a recipient vein in oral microvascular reconstruction. STUDY DESIGN: A retrospective study was done of 36 consecutive cases in which microvascular reconstruction was accomplished with a free flap using the internal jugular vein in an end-to-side fashion. The postoperative patency of 25 internal jugular veins used as recipient veins was examined by postcontrast computed tomography scanning. RESULTS: The overall flap success rate was 97%. Venous thromboses occurred in 2 cases. A common venous thrombosis occurred in one case, but the flap survived after re-anastomosis. In another case, internal jugular vein thrombosis occurred at 5 days of anastomosis, and the flap could not be salvaged by exploratory surgery. All other cases were completely uneventful. All internal jugular veins assessed on postcontrast computed tomography scans were patent at 51 to 107 days after surgery (mean, 89 days). CONCLUSION: Internal jugular vein, if available, is reliable when used as a recipient vein in oral microvascular reconstruction. However, it is not necessarily flawless.

Adult↗
PubMed1998

Comparison of the effect of bezafibrate on improvement of atherogenic lipoproteins in Japanese familial combined hyperlipidemic patients with or without impaired glucose tolerance.

The effect of bezafibrate on plasma lipoproteins was investigated in Japanese familial combined hyperlipidemic patients with or without an impaired glucose tolerance accompanied by a low-density lipoprotein subclass, with the major gradient gel peak at a particle diameter of less than 25.5 nm. Bezafibrate treatment at a dose of 400 mg/d for 12 weeks produced an antiatherogenic effect on lipoprotein profiles, as reflected by a decrease in plasma triglyceride levels, an increase in plasma high-density lipoprotein-cholesterol levels, induction of the large-size subclass of low-density lipoprotein, and disappearance of intermediate-density lipoproteins. The plasma total and low-density lipoprotein-cholesterol-lowering effect of bezafibrate was significant in patients without impaired glucose tolerance but was not significant in patients with impaired glucose tolerance. Bezafibrate increased lipoprotein lipase activity and decreased the activity of cholesteryl ester transfer protein, both in patients with or without impaired glucose tolerance. There was no difference in the distribution of signal peptide insertion/deletion or Xbal polymorphisms of the apolipoprotein B gene in patients with or without impaired glucose tolerance. Mechanisms other than lipoprotein lipase, cholesteryl ester transfer protein activities, and an apolipoprotein B gene polymorphism may be responsible for the resistance to lowering of plasma total and low-density lipoprotein cholesterol levels with bezafibrate treatment in familial combined hyperlipidemic patients with impaired glucose tolerance.

Adult↗
PubMed1998

Clinical application of the Personal Dialysis Capacity (PDC) test: serial analysis of peritoneal function in CAPD patients.

BACKGROUND: Peritoneal damage has been reported since the beginning of CAPD therapy. METHODS: To clarify the change of peritoneal function in CAPD patients, we used the Personal Dialysis Capacity (PDC) test in 22 patients with 49 serial studies and 14 patients with single studies. The data were expressed at the condition of 2.5% (2.27 g/dl of glucose), four times at 2,000 ml/day. RESULTS: In the mass analysis, the urea generation rate, creatinine generation rate, PNA/PCR, and water removal via the peritoneum (PD) were kept at the same level for almost eight years, and then gradually decreased. Urine volume and residual renal creatinine clearance (CCr) became zero at six years. On the other hand, PD CCr increased gradually with the time course of CAPD, and therefore the total CCr remained at the level of 6.0 ml/min even after six years. Weekly urea KT/V decreased gradually from almost 2.800 to 2.000. The protein loss remained approximately 7.0 g/day for the initial five years, then became 6.0 g/day, except in five patients who showed levels above 10.0 g/day on the first test of PDC. Weekly urea KT/V was correlated with residual renal CCr (P < 0.005), and significantly correlated with total CCr (weekly urea KT/V = -0.2798 + 0.3720 x total CCr; r = 0.915, P < 0.001). In the serial analysis, when the first and the last tests were compared, the urea generation rate increased significantly (mean +/- SD, 2.800 +/- 3.204 vs. 3.882 +/- 3.382; P < 0.0001); however, water removal via PD (1364 +/- 887 vs. 813 +/- 609; P = 0.021), total ultrafiltration (1762 +/- 841 vs. 1124 +/- 843; P = 0.042), and weekly urea KT/V (2.285 +/- 0.486 vs. 2.112 +/- 0.512; P = 0.026) decreased significantly. The delta water removal via PD/ duration became negative (-10.03 +/- 6.59 ml/week) in all 7 patients after more than four years, however, it was positive (+14.40 +/- 7.84 ml/week) in 6 of 10 patients after less than one year. CONCLUSION: These results suggest that water removal via PD increases within one year, then decreases after four years. The PDC test is useful to evaluate the change of peritoneal function in mass and serial analyses.

Adult↗
PubMed1998

Crescentic glomerulonephritis accompanied by myeloperoxidase-antineutrophil cytoplasmic antibodies in a patient having myelodysplastic syndrome with trisomy 7.

A 63-year-old woman developed rapidly progressive glomerulonephritis syndrome with serum myeloperoxidase-anti-neutrophil cytoplasmic antibodies (MPO-ANCA). A renal biopsy showed diffuse crescentic glomerulonephritis. Immunofluorescence and electron microscopic studies showed no significant deposits in the glomeruli. The morphological findings were consistent with pauci-immune type crescentic glomerulonephritis. In addition, the patient had erythropoietin-resistant anemia and subsequent pancytopenia. Bone marrow was normocellular without an excess of blasts. However, multinuclear erythroblasts, hypersegmented neutrophils, and megakaryocytes without platelet formation were observed. Chromosome analysis of the bone marrow showed 47,XX,+7. This is the first case of MPO-ANCA-related crescentic glomerulonephritis in a patient with myelodysplastic syndromes (MDS). A possible relationship between MPO-ANCA and MDS is discussed.

Antibodies, Antineutrophil Cytoplasmic↗
PubMed1998

The origin and differentiation of the heteromorphic sex chromosomes Z, W, X, and Y in the frog Rana rugosa, inferred from the sequences of a sex-linked gene, ADP/ATP translocase.

Sex chromosomes of the Japanese frog Rana rugosa are heteromorphic in the male (XX/XY) or in the female (ZZ/ZW) in two geographic forms, whereas they are still homomorphic in both sexes in two other forms (Hiroshima and Isehara types). To make clear the origin and differentiation mechanisms of the heteromorphic sex chromosomes, we isolated a sex-linked gene, ADP/ATP translocase, and constructed a phylogenetic tree of the genes derived from the sex chromosomes. The tree shows that the Hiroshima gene diverges first, and the rest form two clusters: one includes the Y and Z genes and the other includes the X, W, and Isehara genes. The Hiroshima gene shares more sequence similarity with the Y and Z genes than with the X, W, and Isehara genes. This suggests that the Y and Z sex chromosomes originate from the Hiroshima type, whereas the X and W chromosomes originate from the Isehara-type sex chromosome. Thus, we infer that hybridization between two ancestral forms, with the Hiroshima-type sex chromosome in one and the Isehara-type sex chromosome in the other, was the primary event causing differentiation of the heteromorphic sex chromosomes.

Animals↗
PubMed1998

Mechanisms of cytotoxic effects of heavy water (deuterium oxide: D2O) on cancer cells.

Heavy water (deuterium oxide: D2O) contains a neutron and a proton in its hydrogen atoms and shows a variety of biologic activities different from normal light water. In the present study the cytotoxic and cytostatic activity of D2O was assessed using a BALB/c-3T3 fibroblast cell line and four human digestive organ cancer cell lines, i.e. HepG2 hepatic, Panc-1 pancreatic, KATO-3 gastric and Colo205 colonic cancer cell lines. Against four cancer cell lines, D2O showed significant cytotoxic and cytostatic effects in a MTT assay and a Trypan blue dye exclusion assay, at concentrations higher than 30% D2O. These effects were time and dose dependent, and the IC50 after 72 h of culture ranged from 20 to 30% D2O in the Trypan blue dye exclusion assay and from 30 to 50% D2O in the MTT assay. By contrast, IC50 for the 3T3 fibroblast cell line after 72 h of culture was about 15% in the Trypan blue dye exclusion assay and 50% inhibition was not achieved in the MTT assay. Furthermore, D2O was found to significantly inhibit the invasion of tumor cells in a Matrigel invasion chamber assay at concentrations higher than 10% D2O. Incubation with D2O resulted in enlargement of cells, nuclear pyknosis and vacuolization, and immunostaining studies demonstrated that D2O treatment resulted in an increase in nuclear nick-end-labeling, which indicates DNA fragmentation, in KATO-3 and HepG2 cell lines. Furthermore, the nucleic acids and protein synthesis inhibition assay suggested that the inhibition of DNA synthesis may be one of the mechanisms responsible for the antitumor effects of D2O. Furthermore, oral administration of D2O resulted in a significant inhibition of the growth of Panc-1 tumor xenografted s.c. in nude mice, but survival was not prolonged. In conclusion, D2O has cytotoxic and cytostatic activities against human digestive organ cancer cell lines, and D2O may be a potential anticancer agent.

3T3 Cells↗
PubMed1998

Stromal reaction in cancer tissue: pathophysiologic significance of the expression of matrix-degrading enzymes in relation to matrix turnover and immune/inflammatory reactions.

Cancers are characterized by invasive growth and distant metastasis. Cancer cells not only destroy the pre-existing extracellular matrix, but cancer invasion per se usually induces new matrix formation by activation of stromal cells; that is, desmoplastic reaction. This process includes both matrix production and degradation; that is, the remodeling process. The similarity between desmoplastic reactions in cancer stroma and the wound healing process has already been pointed out, and it has been well documented that matrix-degrading processes are actively involved in the would healing process. A recent study revealed that most matrix-degrading enzymes, generally considered to be one of the main mechanisms of cancer invasion and metastasis, are originated from stromal cells. Based on these preconditions, the present review postulates that the abundant expression of matrix-degrading enzymes by fibroblasts, coupled with the abundant expression of type I procollagen, is involved in the matrix remodeling processes occurring in cancer stroma; that is, the mechanism similar to the wound healing process. Next, macrophages distributed along the invasive margin are known to express matrix-degrading enzymes/factors. Data from past studies of colon carcinoma indicate that the tissue expression of matrix metalloproteinase-9 and urokinase-type plasminogen activator receptor is inversely associated with simultaneous liver metastasis and infiltrating growth pattern. Previous clinicopathologic data have indicated that immune/inflammatory cells are one of the factors for a favorable prognosis. This suggests that the expression of matrix-degrading enzymes/factors by these host cells may be involved in host immune/inflammatory reactions, and that the net function of these cells can be defensive towards the host. Data from past studies of colon carcinoma on the expression of the intercellular adhesion molecule-1 suggest that the interaction between macrophages, lymphocytes, and the phenotypes of venules distributed along the invasive margin, further support the pro-inflammatory milleu there. Therefore, the matrix degradation process in cancer tissue is multifunctional: besides the involvement in cancer invasion and metastasis, the matrix degradation process is also involved in the tissue remodeling process and in the immune/inflammatory reaction occurring in the stroma.

Carcinoma↗
PubMed1998

Malignant rhabdoid tumor of the vulva: case report with cytological, immunohistochemical, ultrastructural and DNA ploidy studies and a review of the literature.

A case of malignant rhabdoid tumor of the vulva in a 25-year-old female was examined. The patient presented with a subcutaneous nodule in the left labium majus. Smears of the material obtained by percutaneous fine-needle aspiration demonstrated clusters of atypical cells with prominent nucleoli. The tumor measured 6 x 5 x 5 cm and appeared tan to brown on the cut surface and partly cystic. Pathological findings obtained from intraoperative frozen tissue sections had been originally interpreted as rhabdomyosarcoma. Light microscopic examination revealed that polygonal tumor cells having vesicular nuclei with prominent nucleoli were arranged in sheets and the great majority of the tumor cells contained an eosinophilic globular paranuclear cytoplasmic inclusion. Ultrastructurally, this cytoplasmic inclusion corresponds to whirls of intermediate filaments. Vimentin immunoreactivity was detected in both the cytoplasm and cytoplasmic inclusion of almost all the tumor cells. No cytokeratin and desmin immunoreactivity were detected in the tumor cells. The Ki-67 labeling index was 36% and the DNA content of the tumor cells, which was examined by image cytometry, demonstrated diploidy (DNA index = 0.95).

Adult↗
PubMed1998

Stromal expression of urokinase-type plasminogen activator receptor (uPAR) is associated with invasive growth in primary liver cancer.

AIMS/BACKGROUND: Expression of urokinase-type plasminogen activator receptor (uPAR) was studied in 25 hepatocellular carcinomas (HCCs) and seven cholangiocellular carcinomas (CCCs) by immunohistochemistry. METHODS AND RESULTS: uPAR was expressed mostly by host cells distributed along the tumour-host interface in all cases of HCC and CCC, and its expression was higher in CCC. These uPAR-positive cells were identified as macrophages by observation of serial sections stained for CD68, a marker for macrophages. Cancer cells were positive for uPAR in only one case of poorly differentiated HCC with sarcomatous changes and in three cases of CCC. Hepatocellular carcinomas were classified into two types: those with a fibrous capsule (expansive type) and those without a fibrous capsule (invasive type). Invasive-type HCCs showed more prominent expression of uPAR by macrophages than expansive HCCs (p<0.001), to approximately the same degree as that of CCC. Extrahepatic metastasis was observed in two of 16 expansive HCCs, five of nine invasive HCCs and six of seven CCCs. CONCLUSIONS: Our findings suggest that uPAR expression mainly by macrophages is associated with invasive growth of cancer cells into the surrounding tissue in primary carcinoma of the liver.

Animals↗
PubMed1998

The erythrophore in the larval and adult dorsal skin of the brown frog, Rana ornativentris: its differentiation, migration, and pigmentary organelle formation.

To determine whether or not the erythrophore originates from xanthophores in the dorsal skin of the brown frog, Rana ornativentris, we morphologically examined the differentiation and migration of the two chromatophore types and their pigmentary organelle formation. At an early tadpole stage, three kinds of chromatophores, xanthophores, iridophores, and melanophores, appeared in the subdermis, whereas the erythrophore did so just before the foreleg protrusion stage. By the middle of metamorphosis, most chromatophores other than erythrophores had migrated to the subepidermal space. Erythrophores, which appeared late in the subdermis, proliferated actively there during metamorphosis and finished moving into the subepidermal space by the completion of metamorphosis. Carotenoid vesicles and pterinosomes within the erythrophores and xanthophores showed several significant differences in structure. In xanthophores, carotenoid vesicles were abundant throughout life, whereas those in erythrophores decreased in number with the growth of the frogs. The fibrous materials contained in the pterinosomes were initially scattered but soon formed a concentric lamellar structure. In erythrophores, the lamellar structure began to form at the periphery of the organelles but at the center in xanthophores. In addition, the pterinosomes of erythrophores were uniform in size throughout development, while those of xanthophores showed a tendency to become smaller after metamorphosis. The pterinosomes of xanthophores were significantly larger than those of erythrophores. These findings suggest that an erythrophore is not a transformed xanthophore, although they resemble each other closely in many respects.

Animals↗
PubMed1998

Analysis of lipid components in zooplankter individuals by reactive pyrolysis-gas chromatography in the presence of organic alkali.

It has been eagerly requested to develop a highly-sensitive method to characterize extremely minute amounts of natural organic materials occluded in meteorites and/or space dusts in order to confirm the existence of life in the extraterrestrial space. In this article, the reactive pyrolysis-gas chromatography (Py-GC) applied to the analysis of the lipid components contained in every zooplankter individual is introduced for the sake of its potential extension to the characterization of trace amounts of the extraterrestrial organic materials. Here, Py-GC was applied to 1) the discriminative analysis among zooplankter individuals cultured in different food concentrations, and 2) the correlation analysis between the distributions of fatty acid components in the lipids of zooplankter individuals and ingested algae phytoplankton.

Animals↗
PubMed1998

[The significance of 123I-BMIPP myocardial SPECT on the evaluation of angina pectoris].

Some patients of ischemic heart disease have low uptake in 123I-labeled beta methyl-iodophenyl penta-decanoic acid (BMIPP) SPECT in spite of normal uptake in thallium-201 (Tl) SPECT. To investigate their clinical significance, we performed both T1 and BMIPP myocardial SPECT in 26 cases with stable angina (n = 16) and unstable angina (n = 10), and compared with clinical backgrounds electrocardiogram (ECG) and left ventriculography (LVG). In 11 patients of them, the uptake of BMIPP was moderately reduced. We divided 26 cases into two groups according to uptake of BMIPP (normal/reduced). The two groups had no differences in length of angina attack and duration of disease, but they had a significant difference in the abnormality of either ECG or LVG. Three to six months after PTCA, we examined LVG in 18 cases, 12 of 16 cases with the abnormality of LVG showed the improvement of wall motion. We concluded the reduced uptake of BMIPP with normal uptake of Tl was related to more severe ischemia in cases with unstable angina.

Aged↗
PubMed1998

[Host reactions affect cancer progression].

The tumor-host relationship is one of the factors determining the biological behavior of malignant tumors. In colon cancer, the costimulatory molecules B7-1/B7-2 are expressed by macrophages distributed along the invasive margin (tumor-host interface). T-lymphocytes are also distributed in the same area with direct cell-to-cell contact with these B7+ macrophages. The distribution of these macrophages is lower in colon cancer patients with liver metastasis. CD8+ T cells are distributed within cancer cell nests of colon cancer. The survival rate of patients with higher levels of these T-cells is favorable. Our data suggest the presence of a host immune reaction by macrophages and T-lymphocytes, which diminishes the aggressiveness of cancer cells. As shown in the present paper, comparative analysis is required to assess the biological behavior of cancer.

Antigen Presentation↗
PubMed1998

[Concentrations of free form and complex form of prostate-specific antigen in serum of alpha 2 macroglobulin deficient patients with prostatic carcinoma].

Prostate-specific antigen (PSA) is present in blood in free form as well as in complex form with various protease inhibitors such as alpha 2 macroglobulin (alpha 2M) and alpha 1 antichymotrypsin (alpha 1 ACT). We had found that alpha 2M is deficient (below approximately 40 mg/dl) in some patients with prostatic carcinoma. Therefore, we investigated the levels of free and complex form of PSA in patients with prostatic disease and obtained the following results. The HPLC study showed that total (free plus complex) PSA level was much higher in the alpha 2M deficient patients with prostatic carcinoma stage D (n = 7, range 1,530-14,746 ng/ml, median value 6,800 ng/ml) than in the non-deficient patients with stage D (n = 16, range 121.6-4,210 ng/ml, median value 851 ng/ml). In the deficient patients, the complex of PSA with alpha 1 ACT increased extraordinarily while free PSA increased to only some extent. In the more severe cases of prostatic carcinoma, the ratio (complex/total PSA) was higher while the ratio (free/total PSA) was lower. The SDS-PAGE Western blotting showed that complex PSA increased extraordinarily and free PSA increased in sera of the deficient patients which was consistent with the HPLC results. Many bands appeared on the blotting at the positions smaller than alpha 2M molecule, which indicated that many fragments of alpha 2M were present in their sera. These bands were more intense than the bands with sera of controls or benign prostatic hypertrophy. The alpha 2M deficiency may be due to the rapid disappearance of the complex with PSA or any other prostate-originated proteases. The complex may undergo accelerated degradation or catabolism of alpha 2M.

Aged↗
PubMed1998

[Quantitative levels of serum amyloid A protein and other proteins in cerebrospinal fluid and serum of patients with meningitis].

Serum amyloid A protein (SAA), a putative precursor of the AA protein which constitutes amyloid fibrils in secondary amyloidosis, is evaluated as a sensitive acute-phase reactant in serum. At present, SAA concentration in serum is determined by latex nephelometry, but this assay cannot detect SAA in the low concentration range lower than 10 ng/ml. We have developed a sensitive enzyme immunoassay (EIA) for determining low concentrations of SAA. The assay is reproducible, reliable and requires no pretreatment of specimen prior to assay. We measured levels of SAA by this EIA in both cerebrospinal fluid (CSF) and serum of patients with suspected meningitis, measured also levels of albumin, alpha 2 macroglobulin and C-reactive protein (CRP) to investigate if these protein levels are useful for differential diagnoses of meningitis and for indicators damage of blood-CSF barrier. The SAA reference value in CSF is 3.99 +/- 1.74 ng/ml (mean +/- SD for nonmeningitis patients). The CRP concentration in CSF in bacterial meningitis was much higher than in viral meningitis, but CRP in CSF was also high in bacterial infection other than meningitis. On the other hand, SAA concentration in CSF in these patients with any meningitis are significantly higher than the reference values of SAA (p < 0.001). However, the differences in SAA concentrations among the three types (bacterial, viral and mycotic meningitis) of meningitis were not significant.

Acute-Phase Proteins↗
PubMed1997

Amphidiploidy recovers the viability of hybrids of European and east Asian water frogs.

Reciprocal diploid hybrids, artificially produced from crosses between Rana nigromaculata and Rana lessonae, die at the stage from neurula to tailbud. We found in a previous study that triploid hybrids having two R. nigromaculata genomes and one R. lessonae genome in R. nigromaculata cytoplasm grow into mature frogs, whereas triploid hybrids composed of the other combinations of genome and cytoplasm arrest before hatching. In this study, we made amphidiploid hybrids with two R. nigromaculata and two R. lessonae genomes in the cytoplasm of either species and examined their viability to discover the interaction between parental genomes in each cytoplasm. The amphidiploids with R. nigromaculata cytoplasm developed into mature frogs, whereas ones with R. lessonae cytoplasm arrested at almost the same embryo stage as the lethal triploid hybrids. These findings suggest that the arrest of the reciprocal diploid hybrids is not caused only by the incompatibility between the R. nigromaculata genome and the R. lessonae genome. Taking these together with the results of the triploid hybrids, we suppose that the lethality of the hybrids is mainly due to the incompatibility between the egg cytoplasm and foreign genome(s). With the R. nigromaculata cytoplasm, doubling the maternal genome can ease this incompatibility, but it cannot with the R. lessonae cytoplasm.

Animals↗