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H Itoh

Publications and source records attributed to H Itoh.

At least 613 records · Page 34Linked to original sources
PubMed1996

Reversed-phase HPLC separation of proteins on chemically bonded silica gel columns.

Reversed-phase high-performance liquid chromatographic (RP-HPLC) separation of proteins on chemically bonded silica gel columns is described. Efficiency of nonporous alkylsilyl bonded silica gel is compared with that of a macroporous gel that has been widely used for the purpose. A comparative study of the separation under conventional and fast separation conditions is also given. The fast separation technique on the nonporous reversed-phase column has the advantage of improving the recovery of late-eluting hydrophobic and large proteins, such as ovalbumin and apoferritin.

Chromatography, High Pressure Liquid↗
PubMed1996

Expression of the RET proto-oncogene in normal human tissues, pheochromocytomas, and other tumors of neural crest origin.

In order to evaluate the roles of the RET proto-oncogene in normal human tissues and tumors derived from the neural crest cells, we examined the expression of RET in a variety of adult human tissues, pheochromocytomas, medullary thyroid carcinomas (MTCs), ganglioneuromas, and a neurinoma. Northern blot analysis demonstrated that RET is normally expressed in the adrenal medulla and cerebellum among adult human tissues. RET transcripts were detected in all of 11 sporadic and one familial pheochromocytomas. The levels of RET mRNA were higher in 8 of 12 pheochromocytomas than in the normal adrenal medulla, indicating that RET is overexpressed in the majority of sporadic pheochromocytomas. There was a considerable difference in the level of RET expression in each pheochromocytoma ranging from 0.2 to 10 times the transcripts found in the normal adrenal medulla. The sizes of the transcripts of 7.0, 6.0, 4.5, and 3.9 kb were the same as those found in the adrenal medulla, suggesting no rearrangements of the RET gene in pheochromocytomas. Southern blot analysis revealed neither amplification nor gross structural changes in the RET gene. RET was also expressed at high levels in four MTCs examined, whereas its transcripts were detected at low abundance in only one of three ganglioneuromas. RET was not expressed in a neurinoma. These results suggest that RET may play some roles in a limited range of adult human tissues, and that its high levels of expression may have relevance to development or growth of pheochromocytomas and MTCs.

Adult↗
PubMed1996

Refractory thrombocytopenia with chromosome 11q23 abnormality.

Although cytopenia is a common manifestation of myelodysplastic syndrome (MDS), isolated thrombocytopenia is rare. The term "refractory thrombocytopenia" (RTC) has been proposed as a counterpart of refractory anemia. We describe here a case of RTC associated with chromosome abnormality on 11q23. A 59-year-old man was admitted because of severe thrombocytopenia. A bone marrow examination revealed an increased number of micromegakaryocytes and the absence of normal-sized megakaryocytes without obvious dysplasia in either the myeloid or the erythroid lineage. A remarkable increase of GPIIb/IIIa (CD41a)-positive precursor cells in the bone marrow was observed. Cytogenetic examination detected the chromosome abnormality, an addition on chromosome 11q23. Translocation of the HRX gene was not detectable by Southern blot analysis. The diagnostic problems of isolated thrombocytopenia and possible participation of gene(s) on chromosome 11q23 in megakaryocytopoiesis as well as early hematopoiesis are discussed.

Biopsy, Needle↗
PubMed1996

GABAB-ergic stimulation in hypothalamic pressor area induces larger sympathetic and cardiovascular depression in spontaneously hypertensive rats.

To determine whether central GABA (gamma-aminobutyric acid) B receptor stimulation would affect the sympathetic and cardiovascular activities, baclofen (a GABAB receptor agonist) was injected into lateral cerebral ventricles (intracerebroventricularly, ICV) in urethane-anesthetized normotensive rats. Intracerebroventricular injections of GABAA agonist (muscimol, 1 microgram) consistently decreased blood pressure and heart rate. In contrast ICV injections of baclofen (2 micrograms) increased blood pressure (BP) and heart rate with initial transient cardiovascular depression, and these effects of baclofen were abolished by ICV pretreatment with GABAB antagonist (saclofen, 100 micrograms). To determine whether the cardiovascular effects of ICV injections were elicited by activating GABA receptors in the hypothalamus, we injected baclofen or muscimol directly into various hypothalamic areas. Baclofen (100 and 800 ng) injected into the ventromedial hypothalamus (VMH) or posterior hypothalamus (PH) of normotensive rats produced dose-related decreases in sympathetic nerve activity, blood pressure, and heart rate. These effects of baclofen were larger in VMH injections than in PH injections. The depressor responses elicited by VMH injections of baclofen were abolished by intravenous pretreatment with alpha-blocker, but unaffected by parasympathetic blocker, further indicating that the depressor responses of baclofen (VMH) were not due to parasympathetic activation, but due to peripheral sympathetic depression. Muscimol (400 ng) and baclofen (800 ng) injected into VMH produced similar amplitude of sympathetic-depressant, depressor and bradycardic responses. In contrast, BP was increased by the same dose of baclofen injected into the hypothalamic depressor area (anterior hypothalamus, AH), but was unaffected by muscimol. Final experiments were performed to determine whether these sympathetic and cardiovascular effects to hypothalamic GABAB stimulations would be altered in hypertension. In spontaneously hypertensive rats (SHR), basal BP and heart rate were already higher than in normotensive controls (Wistar-Kyoto rat, WKY). Baclofen injected into VMH reduced sympathetic nerve activity, BP, and heart rate in both groups of rats, and these effects were significantly larger in SHR than in WKY. This enhanced depressor response induced by baclofen (VMH) in SHR persisted even after sinoaortic denervation, which indicates that the enhanced depressor response is not due to reduced peripheral baroreflex sensitivity in SHR. On the other hand, baclofen injected into AH increased BP and heart rate in both WKY and SHR, but the magnitude of these responses did not differ between two groups. In summary, GABA reduces sympathetic nerve activity, BP, and heart rate through both GABAA and B receptors in VMH. The GABAB system acts on the depressor area, AH, to further regulate the cardiovascular activities. In SHR, the GABAB-ergic system in VMH but not in AH is altered, and this might contribute to the development of hypertension.

Animals↗
PubMed1996

Preparation of giant liposomes in physiological conditions and their characterization under an optical microscope.

Unilamellar liposomes with diameters of 25-100 microns were prepared in various physiological salt solutions, e.g., 100 mM KCl plus 1 mM CaCl2. Successful preparation of the giant liposomes at high ionic strengths required the inclusion of 10-20% of a charged lipid, such as phosphatidylglycerol, phosphatidylserine, phosphatidic acid, or cardiolipin, in phosphatidylcholine or phosphatidylethanolamine. Three criteria were employed to identify unilamellar liposomes, yielding consistent results. Under a phase-contrast microscope those liposomes that showed the thinnest contour and had a vigorously undulating membrane were judged unilamellar. When liposomes were stained with the lipophilic fluorescent dye octadecyl rhodamine B, fluorescence intensities of the membrane of individual liposomes were integer multiples (up to four) of the lowest ones, the least fluorescent liposomes being those also judged unilamellar in the phase-contrast image. Micropipette aspiration test showed that the liposomes judged unilamellar in phase and fluorescence images had an area elastic modulus of approximately 160 dyn/cm, in agreement with literature values. The giant liposomes were stable and retained a concentration gradient of K+ across the membrane, as evidenced in fluorescence images of the K(+)-indicator PBFI encapsulated in the liposomes. Ionophore-induced K+ transport and associated volume change were observed in individual liposomes.

Elasticity↗
PubMed1996

Split transplantation of the trachea: a new operative procedure for extended tracheal resection.

Before tracheal transplantation can be applied clinically, several problems must be solved: immunosuppression, blood supply to grafts, and reliable long-term preservation of grafts. We have conducted experiments on tracheal transplantation to solve these problems. In the present study, we tried a new operative procedure to accomplish reliable revascularization of transplanted tracheal grafts. It has been reported that transplantation of a 10-ring length of trachea is difficult even with omentopexy. Long tracheal allografts can be transplanted with use of direct revascularization, but this technique is extremely troublesome. Thus we developed a new operative procedure, "split tracheal transplantation," in which grafts are divided at the midportion and covered with omentum, after demonstrating that the blood supply to tracheal grafts can be reestablished around the suture lines. Two groups of dogs were used. In group A (control, n = 4), a 10-ring length of trachea was autotransplanted. The anastomotic sites and grafts were covered with omental pedicles. In group B (split tracheal transplantation, n = 10), tracheal grafts 10 rings long were autotransplanted. These grafts were divided at the midportion, a piece of omentum was inserted between the two halves, and the midportion was sutured. Grafts were observed regularly by bronchoscopy and examined histopathologically after the animals died or were killed. In some animals, microangiography of the bronchial circulation was done. In the control group, necrosis, stenosis, or malacia of the grafts was observed in three of the four animals. In the split transplantation group, all animals survived for at least 2 months, all grafts were incorporated, and none showed ischemia, stenosis, or malacia. Microscopic examination and microangiography revealed that neovascularization of the graft was promoted by omentum inserted at the midportion of the graft. Split transplantation of the trachea is an easy and reliable way to extend tracheal resection.

Anastomosis, Surgical↗
PubMed1996

Glucose loading induces DNA fragmentation in rat proximal tubular cells.

A 10% glucose, 10% mannitol, or 0.9% saline solution was infused in male Wistar rats for 300 minutes via the left cervical vein. Glomerular filtration rates (GFRs) were not significantly altered in any of the three groups. DNA was extracted from isolated proximal tubular cells at the end of each infusion. Electrophoresis on agarose gels showed a distinct ladder pattern of DNA fragmentation in 10% glucose-loaded rats, but no such pattern in 10% mannitol- or 0.9% saline-loaded rats. After infusion for 300 minutes, the plasma glucose level of the 10% glucose-loaded group was higher than that of the other two groups (each P < .005). These results suggest that hyperglycemia led to DNA fragmentation in the DNA of proximal tubular cells, similar to the process of programmed cell death known as apoptosis. DNA fragmentation may be associated with renal proximal tubular damage in the early stages of diabetic nephropathy.

Animals↗
PubMed1996

Centroblastic and centroblastic-centrocytic lymphomas associated with prominent epithelioid granulomatous response without plasma cell differentiation: a clinicopathologic study of 12 cases.

To clarify the clinicopathologic features of B-cell lymphoma associated with prominent epithelioid granulomatous responses other than immunocytomas, 12 patients were studied. There were six men and six women. The lymphoma generally affected elderly patients (median age, 58.5 years) and was mostly nodal in origin. Seven of the 12 patients had a localized lesion (stage I or II), and five had an advanced lesion (stage III or IV). Histologically, four patients showed a follicular growth pattern and eight a diffuse growth pattern. Based on the updated Kiel classification, nine patients showed centroblastic lymphomas, and three showed centroblastic-centrocytic lymphomas. The epithelioid cells were accumulated in large, poorly demarcated masses. Trabecular fibrosis compartmentalized in the lymph nodes, producing a vague nodular pattern in low-power fields. Immunohistochemical studies of the tumor cells revealed positive membrane staining with L26 in all 12 patients and with LN-1 antibody in 9 of 10 patients. Expression of the bcl-2 protein was present in all seven patients tested. Genotypic investigation exhibited germline configuration of the immunoglobulin heavy chain gene, the T-cell receptor beta-chain gene and the bcl-2 gene in all three patients investigated. By in situ hybridization, Epstein-Barr virus genomes were detected in only a few tumor cells in three of the patients tested. This study indicated that most, if not all, of the B-cell lymphomas with prominent epithelioid granulomatous responses other than immunocytoma were of follicular center cell origin.

Adult↗
PubMed1996

Expression ratio of hepatocyte nuclear factor-1 to variant hepatocyte nuclear factor-1 in differentiation of hepatocellular carcinoma and hepatoblastoma.

BACKGROUND/AIMS: Liver-specific protein genes have multiple cis-/trans-acting elements, but those accountable for hepatocytic differentiation are unclear. An AT-rich core sequence (AT motif) is essential as a cis-acting element for the hepatic transcription. Homologous proteins hepatocyte nuclear factor-1 (HNF-1) and variant HNF-1 (vHNF-1) bind to this motif. The ratio of HNF-1 to vHNF-1 mRNA was examined in various liver tissues with respect to their differentiation. METHODS: The competitive reverse transcriptional polymerase chain reaction was employed to amplify HNF-1 and vHNF-1 mRNA simultaneously and to examine their expression ratio in total RNA extracted from frozen liver tissues of 37 patients with hepatocellular carcinoma, five patients with hepatoblastoma, and 15 non-neoplastic liver tissues. RESULTS: The ratio of HNF-1 to vHNF-1 mRNA was higher in well-differentiated cases than in poorly-differentiated and undifferentiated cases, except that one poorly-differentiated hepatoblastoma displayed a high ratio. Non-neoplastic liver tissues had low ratios similar to poorly-differentiated hepatocellular carcinoma, the reason for which remained unknown. However, chronic hepatitis and liver cirrhosis cases also demonstrated low ratios, and hence degenerative changes themselves displayed no obvious influence on such ratios. Thus, the gene expression of HNF-1 and vHNF-1 seemed to be differentially regulated in neoplastic and non-neoplastic hepatocytes. CONCLUSIONS: These results suggested that the ratio of HNF-1 to vHNF-1 mRNA correlated with histological differentiation of HCC and hepatoblastoma.

Adult↗
PubMed1996

Growth of cultured human bronchiogenic epithelioid CCD-14 Br cells and dermal fibroblasts, NB1 RGB treated with ginseng tetrapeptide and its isomer.

The configurations of the component amino acids in ginseng tetrapeptide 1 isolated from Panax ginseng were determined by HPLC with an optical resolution column and the structure of 1 was established to be H-L-Val-gamma-D-Glu-D-Arg- Gly-OH. Synthesis of the ginseng tetrapeptide, 1, and of the configuration and conjugation isomers, H-L-Val-gamma-L-Glu-L-Arg-Gly-OH (2), H-L-Val-D-Glu- D-Arg-Gly-OH (3), and H-L-Val-L-Glu-L-Arg-Gly-OH (4) was carried out by a solid-phase method using the Fmoc strategy. The effects of 1-4 on the proliferation of baby hamster kidney (BHK)-21 cells, normal female bronchiogenic epithelioid (CCD-14 Br) cells, and normal human epidermal fibroblast (NB1 RGB) were examined. Only 1 showed 32 and 23% enhancement of BHK-21 and human CCD-14 Br cells growth, respectively, at a concentration of 13.6 microM and 41% enhancement of NB1 RGB cells growth at a concentration of 32 microM under the conditions employed. It was shown that both the configuration of the component amino acids and the peptide conjugation at a gamma-position of D-Glu in 1 are important for proliferation of the cells. Compound 1 exerted a prominent effect on cell stimulation and growth rate without any morphological change and showed no cytotoxicity.

Amino Acid Sequence↗
PubMed1996

Cloning of the cDNA encoding mouse PP5/TFPI-2 and mapping of the gene to chromosome 6.

Placental protein 5 (PP5)/tissue factor pathway inhibitor-2 (TFPI-2) is a new homologue of TFPI, which contains three tandemly repeated Kunitz-type proteinase inhibitory (KPI) domains and potently inhibits the extrinsic blood coagulation cascade. In this study, mouse PP5/TFPI-2 cDNA was cloned using a human PP5/TFPI2 cDNA fragment as a probe. The characteristic three KPI domains with short spacer sequences and a basic amino acid stretch in the carboxyl-terminal region present in human PP5/TFPI-2 were well conserved in mouse PP5/TFPI-2. In general, the P1 reactive site residues of active KPI domains are basic amino acids. However, the putative P1 residues of the first, second, and third KPI domains were glutamine, aspartic acid, and serine, respectively. Mouse PP5/TFPI-2 mRNA was highly expressed in developing placenta as in humans. Adult liver and kidney also contained a significant amount of its transcripts. The mouse PP5/TFPI-2 gene was found to be located in the R-positive A2 band by the direct R-banding FISH and identified at 2.7 cM proximal to D6Mit 1 by interspecific backcross analysis.

Amino Acid Sequence↗
PubMed1996

Glutathione S-transferase M1 (GSTM1) and T1 (GSTT1) genetic polymorphism and susceptibility to gastric and colorectal adenocarcinoma.

Genes coding for the glutathione S-transferase M1 (GSTM1) and Theta 1 (GSTT1) proteins are polymorphic in humans and these genes are absent, or homozygous null, in 10-60% of different ethnic populations. These enzymes catalyze the conjugation of glutathione to numerous carcinogenic chemicals and previous epidemiologic studies have associated the null genotypes of these GST genes with higher risk of cancer. In this study the frequency of GSTM1 and GSTT1 null genotypes was determined in Japanese patients with gastric adenocarcinoma and colorectal adenocarcinoma and compared to frequencies determined in a community-based control group. The frequency of the null GSTM1 genotype in patients with gastric adenocarcinoma (56.8%) showed a statistically significant increase compared to the control group frequency (43.6%) (odds ratio (OR) = 1.70; 95% CI, 1.05-2.76). The frequency of GSTM1 null individuals was also higher among all colorectal adenocarcinoma cases, but this increase did not reach statistical significance. After grouping by tumor site, the GSTM1 null genotype was a risk factor among the subgroup with distal colorectal tumors (61.1%) (OR = 2.03; 95% CI, 1.06-3.90). No consistent difference was observed between smoking patients and corresponding controls for the frequency of the GSTM1 null genotype for either cancer, although a large risk (OR = 5.76; 95% CI 1.18-28.3) was associated with the GSTM1 null genotype in the low smoking group of gastric adenocarcinoma patients. On the other hand, no statistically significant differences were observed in the frequency of null GSTT1 genotypes in gastric (47.5%) or colorectal (48.5%) adenocarcinoma patients when compared with the control population (44.4%). These results suggest that the GSTM1 null genotype may be associated with susceptibility to gastric adenocarcinoma and distal colorectal adenocarcinoma in Japanese; however, the associations observed were relatively weak and additional studies will be needed to confirm these findings.

Adenocarcinoma↗
PubMed1996

Expression of inter-alpha-trypsin inhibitor light chain (bikunin) in human pancreas.

Expression of inter-alpha-trypsin inhibitor light chain (ITI-LC, also known as bikunin or urinary trypsin inhibitor) was examined in various human tissues. By reverse-transcription polymerase chain reaction, the mRNA was detected not only in the liver, a known site of ITI-LC production, but also in the kidney, heart, lung, and pancreas. By RNA blot analysis, the mRNA was also detected in the pancreas and liver, but not in the kidney, heart, or lung. The ITI-LC protein was immunohistochemically detected along the surface of pancreatic acinar cells. These results indicate the apparent expression of the gene for ITI-LC in the pancreas. ITI-LC protein on the surface of pancreatic acinar cells may play an important role in preventing autodigestion by exocrine enzymes such as trypsinogen and chymotrypsinogen.

Base Sequence↗
PubMed1996

Regulation of secretion and clearance of C-type natriuretic peptide in the interaction of vascular endothelial cells and smooth muscle cells.

OBJECTIVE: To clarify the significance of C-type natriuretic peptide in the interaction between endothelial cells and vascular smooth muscle cells by investigating the endothelial production of C-type natriuretic peptide and the clearance mechanism of C-type natriuretic peptide using the endothelial cells-smooth muscle cells co-culture system. RESULTS: Secretion of C-type natriuretic peptide in the direct co-culture of endothelial cells with smooth muscle cells elicited as much as a 60-fold increase compared with endothelial cells alone. The accumulation of intracellular cyclic GMP in the co-culture was consequently increased and the elevation of cyclic GMP level in the co-culture was abolished by the anti-C-type natriuretic peptide monoclonal antibody. The elevated cyclic GMP production in the co-culture was abolished by the anti-transforming growth factor-beta neutralizing antibody. Candoxatrilat (10(-6)-10(-4) mol/l), a neutral endopeptidase inhibitor, dose-dependently increased the concentrations of C-type natriuretic peptide in the culture medium with endothelial cells alone, but not in the endothelial cells-smooth muscle cells co-culture. The transcript of neutral endopeptidase messenger RNA was detected in endothelial cells but not in smooth muscle cells by reverse transcriptase polymerase chain reaction. Treatment with C-atrial natriuretic factor4-23 (10(-9)-10(-6) mol/l), the specific ligand for the clearance receptor of the natriuretic peptides, resulted in dose-dependent augmentation of C-type natriuretic peptide concentration and concomitant intracellular cyclic GMP production in the endothelial cells-smooth muscle cells co-culture but not in endothelial cells alone. CONCLUSION: The present study demonstrated that direct interaction between endothelial cells and smooth muscle cells augments C-type natriuretic peptide secretion from endothelial cells through transforming growth factor-beta activation, and revealed that the enzymatic degradation is responsible for the steady state level of C-type natriuretic peptide in endothelial cells alone and that the receptor-mediated clearance mainly determines the augmented level of C-type natriuretic peptide in the interaction between endothelial cells and smooth muscle cells. The results taken together raise the possibility that endothelial C-type natriuretic peptide might play a role in regulation of vascular tone and remodelling.

Animals↗
PubMed1996

The natriuretic peptide family.

The natriuretic peptide system is a complicated system comprising at least three endogenous peptides (atrial natriuretic peptide, brain natriuretic peptide and C-type natriuretic peptide) and three receptors [the atrial natriuretic peptide-A receptor (guanylyl cyclase A), the atrial natriuretic peptide-B receptor (guanylyl cyclase B) and the clearance receptor]. The accumulated evidence indicates that this system is implicated in the control of blood pressure, body fluid homeostasis and vascular remodelling as cardiac hormone and local regulator.

Animals↗
PubMed1996

Efficacy and side effects of intermittent recombinant interferon-alpha 2a in chronic aggressive hepatitis C: with or without initial daily administration.

To investigate the therapeutic effect and incidence of side effects of recombinant interferon-alpha 2a (IFN-alpha) in chronic aggressive hepatitis C under stratification by administration mode, a study was conducted by assigning patients to either group A (daily consecutive administration of 9 million units (MU) IFN-alpha for 2 weeks and, thereafter, 3 MU intermittently 3 times weekly for 22 weeks) or group B (exclusively intermittent administration; 9 MU IFN-alpha twice weekly or 6 MU IFN-alpha thrice weekly for 24 weeks). The 28 patients in group A received IFN-alpha for 24 weeks up to a total dose of 324 MU and the 53 patients in group B received the same for 24 weeks up to a total dose of 432 MU. When recovery was defined as the absence of hepatitis C virus (HCV)-RNA 6 months after the completion of treatment, the rate of recovery for group A was 32.1% and that for group B was 37.7%, the latter being higher but without significance. Side effects in groups A and B consisted of leucopenia occupying 14.3 and 7.5%, respectively, and thrombocytopenia occupying 42.9 and 11.3%, respectively; group B exhibited lower values for both side effects. No difference was detected between these groups in other side effects, including pyrexia, generalized malaise, arthralgia or psilosis. Intermittent administration from the outset permitted shortened duration of hospitalization and earlier rehabilitation. Intermittent administration of INF-alpha is required when treating patients with chronic hepatitis C showing lower leucocyte or platelet counts.

Chronic Disease↗
PubMed1996

Imprint cytology of cat scratch disease. A report of eight cases.

The cytologic features of cat scratch disease (CSD) from eight cases in imprint smears are presented. All patients were clinicopathologically diagnosed with CSD as follows: 1) a history of animal exposure was recorded 2 to 4 weeks before lymphadenopathy; 2) the disease occurred in the autumn and winter months; 3) a characteristic histopathology in the biopsied lymph node specimens was observed; and 4) Warthin-Starry silver stain-positive bacteria were detected in four of the seven cases examined. The characteristic cytologic finding was the presence of confluent epithelioid cells with nearby and central scattering of neutrophils against a background of polymorphic inflammatory cells. Furthermore, a varying number of medium-sized to large lymphoid cells with an appearance suggestive of monocytoid B lymphocytes (MBLs) were noted to be associated with the epithelioid cells. These cytologic findings closely paralleled the histologic patterns of epithelioid cell granulomas, with and without MBLs, which we have previously reported are probably associated with the disease.

Adult↗