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Biomedical subjects

H Itoh

Publications and source records attributed to H Itoh.

At least 595 records · Page 33Linked to original sources
PubMed1996

Increase of a type of oxidative DNA damage, 8-hydroxyguanine, and its repair activity in human leukocytes by cigarette smoking.

To investigate the oxidative stress induced by cigarette smoking, the levels of a form of oxidative DNA damage, 8-hydroxyguanine (8-OH-Gua), and its repair activity in the leukocytes of current smokers, ex-smokers, and complete nonsmokers were measured. The mean level of 8-OH-Gua was 1.88-fold higher in smokers as compared to complete nonsmokers (the difference was statistically significant, P = 0.013). The mean 8-OH-Gua repair activity was 1.6-fold higher in smokers than complete nonsmokers (the difference was statistically significant, P = 0.0053). A positive association was observed for the 8-OH-Gua levels and its repair activity. Considerable interindividual variations in the 8-OH-Gua levels (current smokers, 3.5-fold; nonsmokers, 7.2-fold) and in its repair activity (current smokers, 7.5-fold; nonsmokers. 5.5-fold) were observed. These results demonstrate that not only smoking status but also life-style, environment, and genetic differences might have effects on the level of 8-OH-Gua and its repair activity in human leukocytes.

Adult↗
PubMed1996

Topographic representation in human intraparietal sulcus of reaching and saccade.

Regional cerebral blood flow was measured by positron emission tomography in seven subjects during reaching with saccade, reaching without saccade, saccade and control tasks. The reaching with saccade task activated two spatially distinct areas in the contralateral intraparietal sulcus (IPS) compared with the control condition. The area located in the anterior part of the IPS was also activated during the reaching without saccade but not during the saccade task. The other area, located in the posterior part of the IPS was, in contrast, active during the saccade but not the reaching without saccade task. The results indicate that the human IPS is functionally heterogeneous, and that functional roles of its anterior and posterior parts include control of reaching movements and eye movements, respectively.

Adolescent↗
PubMed1996

Molecular cloning and expression of human caldecrin.

Earlier we reported the primary structure of serum calcium-decreasing factor (caldecrin) from rat pancreas, a protein which is considered to be a member of the elastase family. In this report, we describe the isolation of the two homologous cDNA clones encoding caldecrin from human pancreas, the structures of which are identical except for one base and the corresponding amino acid residue. These human caldecrin isoforms are composed of a signal peptide of 16 amino acids, a propeptide of 13 amino acids, and a mature form of 239 amino acids. Both recombinant caldecrins showed the same chymotrypsin-type protease activity and hypocalcemic activity. The hypocalcemic activity of both remained intact even after treatment with PMSF to abolish their protease activity. These results suggest that human caldecrin possesses hypocalcemic activity that has no connection with its protease activity.

Amino Acid Sequence↗
PubMed1996

Changes in regional cerebral blood flow during self-paced arm and finger movements. A PET study.

The purpose of this study was to identify the functional fields activated in relation to the self-paced proximal and distal arm movements. The regional cerebral blood flow (rCBF) was measured with positron emission tomography (PET) and 15O-labelled H2O (H2(15)O) in eight healthy subjects. All subjects performed the following three tasks: (1) repetitive opposition of thumb and index finger of the right hand, (2) repetitive co-contraction of biceps and tricepts brachii muscles of the right arm, and (3) rest. The mean rCBF change images for each task minus control was calculated and fields of significant rCBF changes were identified. Each movement activated different fields in the primary motor area (MI), the dorsal aspect of the premotor area (PMA) and the superior part of the prefrontal area (PFA) of the contralateral hemisphere. In these areas, arm fields were located relatively dorsally to the finger fields. In addition, specific fields in the ventral part of the PMA, the supplementary motor area (SMA), the superior parietal lobule (SPL) of the contralateral hemisphere, and the ipsilateral PFA were consistently activated during both movements. Due to a limited a field of view of the PET scanner in the axial direction, the PET scan could not cover the cerebellum. The results indicate that there may be somatotopical organization not only in the MI but also in the dorsal part of the PMA and the PFA, and that the specific fields in the ventral part of the PMA, the SMA, the SPL, and the PFA may be involved in self-paced movement.

Adult↗
PubMed1996

Cloning of the cDNAs for mast-cell chymases from the jejunum of Mongolian gerbils, Meriones unguiculatus, and their sequence similarities with chymases expressed in the connective-tissue mast cells of mice and rats.

By using the combination of reverse-transcription CR and rapid amplification of cDNA ends methods, two distinct cDNAs encoding mast-cell proteases (chymases; MCPs), designated as gMCP-1 and -2, were successfully cloned and sequenced from the jejunum of Mongolian gerbil, Meriones unguiculatus, infected with Nippostrongylus brasiliensis. On the basis of a comparison of the deduced amino acid sequences with those of known rodent mast-cell chymases, gMCP-1 was found to be highly similar to mouse mast-cell protease (mMCP)-4 and rat mast-cell protease (rMCP)-1, while gMCP-2 was similar to mMCP-5 and rMCP-3. Alghough mMCP-4 and -5 and rMCP-1 and -3 were restrictedly or mainly expressed in connective-tissue mast cells and serosal mast cells, the gMCP-1 and -2 genes were mainly transcribed in the jejunal mucosa and to a lesser extent in the skin and tongue. Moreover, kinetic study after infection revealed that the amounts of the gMCP-1 and -2 mRNAs in jejunum paralleled well the degree of intestinal mastocytosis. The expression of gMCP-1 and -2 in mucosal mast cells of gerbil jejunum was also confirmed by in situ hybridization. Since a tryptase, another type of MCP, was also expressed in mucosal mast cells of gerbils but not in those of mice and rats, the expression of MPCs in mucosal mast cells of gerbils is different from those of mice and rats. The Mongolian gerbil would be a useful model with which to investigate the physiopathological role of MCPs.

Amino Acid Sequence↗
PubMed1996

In vitro analysis of peritoneal adhesions in peritonitis.

Peritoneal adhesions due to peritonitis make surgery more difficult and may cause complications. Clarifying the formation mechanism of peritoneal adhesions could help identify methods useful for their prevention. We cultured mesothelial monolayers on plates and microcarriers to simulate the parietal and visceral peritoneum, respectively. We then investigated the effects of lipopolysacchride (LPS) and tumor necrosis factor (TNF) on the homologous adhesion of these mesothelial monolayers. There was no adhesion of mesothelial monolayers in the control medium. When monolayers were cultured with endotoxin (LPS), approximately 90% of the microcarriers adhered to the mesothelial microplate. Adhesions occurred at LPS concentrations of 10 ng/ml and increased linearly in a dose-dependent manner. Kinetic studies revealed that the mesothelial adhesion appeared at 12 hr, and that 90% of the microcarriers were adherent after 24 hr. Open intercellular spaces were observed after a 24-hr treatment with LPS. Scanning electron microscopy revealed that the mesothelial cells adhered to the naked glass. LPS also caused increased permeability of the mesothelial monolayer. TNF did not cause any significant adhesion. Through our experiments we were able to develop an in vitro model of peritoneal adhesion using peritoneal mesothelial cell culture. Endotoxin caused an increase in homologous adhesion of peritoneal mesothelial monolayers, which may correspond to the initial stage of peritoneal adhesion formation in peritonitis.

Dose-Response Relationship, Drug↗
PubMed1996

Alternative RNA splicing of the human endothelin-A receptor generates multiple transcripts.

In order to elucidate the regulatory mechanisms of expression of the human endothelin-A receptor (hET-AR) gene, we characterized hET-AR transcripts using reverse transcriptase (RT)-PCR analysis in a variety of human tissues. RT-PCR of lung mRNA using a set of primers from exons 2 and 5 showed two lower-molecular-mass transcripts in addition to the expected fragment. When RT-PCR with primers from exons 4 and 8 was performed, no transcripts other than the expected one were detected. PCR cloning utilizing a set of primers from exons 2 and 8 which covered the entire coding sequence revealed that the cDNA clones corresponding to the two novel transcripts contained deletions of 199 bp and 327 bp respectively compared with the previously described hET-AR cDNA. Comparison of their sequences with that of the hET-AR gene showed that the deleted sequences correspond exactly to exon 4 and exons 3 and 4 respectively, indicating that these lower-molecular-mass ET-AR transcripts results from alternative RNA splicing (designated ET-AR delta 4 and ET-AR delta 3,4 respectively). Alternative splicing of exon 4 results in a transcript which would be translated into a C-terminal truncated protein containing the first, second and third transmembrane domains, while the splicing out of exons 3 and 4 would produce a protein with five membrane-spanning domains but lacking the third and fourth domains present in the ET-AR protein. An RNase protection assay revealed that ET-AR delta 4 and ET-AR delta 3,4 as well as ET-AR, transcripts were observed in various human tissues, including the lung, aorta, atrium, kidney and placenta, which are known to express ET-AR abundantly. Thus we have isolated the cDNAs of novel transcripts of hET-AR which are generated by alternative RNA splicing, and these results suggest that this alternative RNA splicing might contribute to the regulation of ET-AR gene expression.

Alternative Splicing↗
PubMed1996

Radical surgery for advanced gallbladder carcinoma.

Forty-four patients with advanced gallbladder carcinoma (18 with stage pT3 and 26 with stage pT4 of the Union Internacional Contra la Cancrum classification) were aggressively managed by extended heptatic resection in 33 patients, bile duct resection in 28, pancreaticoduodenectomy in seven, gastrointestinal resection in eleven and portal vein resection and reconstruction in seven. Adjacent organ involvement was classified as follows: type I, hepatic involvement with or without gastrointestinal invasion (Ia, Ib); type II, bile duct involvement with or without gastrointestinal invasion (IIa, IIb); type III, hepatic and bile duct involvement with or without gastrointestinal invasion (IIIa, IIIb); type IV, gastrointestinal involvement without hepatic or bile duct invasion. Fourteen of 15 patients with type I tumours had a curative resection compared with seven of 26 with type III lesions (P < 0.0001). The surgical mortality rate was two of 15 patients with type I tumours, seven of 26 with type III tumours and nine of 44 for the whole group. The long-term survival rate after curative resection was four and two of 23 at 3 and 5 years respectively, significantly better than two and none of 21 at 1 and 2 years after non-curative resection (P < 0.01). The survival rate after curative resection for patients with type I tumours was four and two of 14 at 3 and 5 years respectively, significantly better than for other types (P < 0.05). This classification of advanced gallbladder carcinoma according to involvement of adjacent organs might be helpful in planning surgery for this condition; in particular, type I tumours should be treated by a radical surgical procedure to achieve a favourable outcome.

Adenocarcinoma↗
PubMed1996

Reduced hepatic acute-phase response after simultaneous resection for gastrointestinal cancer with synchronous liver metastases.

Serum cytokines and hepatic acute-phase responses were studied in seven patients undergoing simultaneous resection of primary gastrointestinal cancer and synchronous metastatic liver tumours and in 12 undergoing partial hepatectomy alone for metachronous hepatic metastases. The incidence of postoperative infectious complications was significantly higher after simultaneous resection than after partial hepatectomy alone (P < 0.05). Although the peak interleukin 6 level was significantly higher after simultaneous resection (P < 0.05), plasma levels of acute-phase proteins were significantly lower (P < 0.05). The results suggest that simultaneous resections further reduce the hepatic acute-phase response and render patients liable to infection compared with partial hepatectomy alone, and result in a higher incidence of postoperative infective complications.

Acute-Phase Proteins↗
PubMed1996

Two cardiac natriuretic peptide genes (atrial natriuretic peptide and brain natriuretic peptide) are organized in tandem in the mouse and human genomes.

Atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP), which act as cardiac hormones, are produced mainly by the atrium and ventricle, respectively, and are involved in body fluid homeostasis and blood pressure control. The ANP and BNP gene expressions are markedly augmented in ventricles of patients with a wide variety of cardiovascular diseases. It has been demonstrated that the ANP and BNP genes are tightly linked on mouse chromosome 4 and on the distal short arm of human chromosome 1. However, the precise physical map of the ANP and BNP genes has never been elucidated. In the present study, we characterized the genomic DNA fragment containing the ANP and BNP genes in mice and humans. Three genomic DNA clones harboring the entire mouse BNP gene were isolated from a 129/Sv mouse genomic DNA library. Nucleotide sequence analysis revealed that a phage clone (lambda mBNP #3) contains at its 3'-end the 5'-flanking region and the first 209-bp sequence of the first exon of the mouse ANP gene. In mice, the BNP gene was located about 12 kb upstream of the ANP gene. By polymerase chain reaction, we isolated an approximately 11-kb human genomic DNA fragment containing the third exon of the BNP gene and the first and second exons of the ANP gene. In humans, the BNP gene was located upstream of the ANP gene, approximately 8 kb apart. The present study provides the direct evidence that the ANP and BNP genes are organized in tandem in the mouse and human genomes.

Animals↗
PubMed1996

Effects of lumbar sympathectomy on the properties of both endothelium and smooth muscle cells of the canine femoral artery and autogenous vein grafts under poor runoff conditions.

The purpose of this study was to determine whether or not a lumbar sympathectomy would modulate the functions of the endothelium, in terms of endothelium-derived relaxing factor (EDRF), under poor distal runoff conditions. First, a poor distal runoff model was developed in the canine right and left femoral arteries. After 5 weeks, a unilateral left sympathectomy was performed from L-3 to L-6. In experiment I, changes in blood flow and endothelium-dependent responses were examined in the canine femoral artery 5 weeks after the lumbar sympathectomy. In experiment II, 5 weeks after the development of a poor runoff model, a unilateral left sympathectomy was performed and both femoral veins were also grafted to the femoral arteries on both sides. Then after 4 weeks, endothelium-dependent responses and intimal thickening of both autogenous vein grafts were examined. The endothelium-dependent responses were examined by mechanical tension recording. In both experiments, the mean blood flow of the left femoral arteries (denervated, 92.2 +/- 47.1 ml/min) and vein grafts (denervated, 100.0 +/- 35.4 ml/min) was significantly higher than that of the right femoral arteries (innervated, 46.9 +/-25.7 ml/min) and vein grafts (innervated, 50.0 +/- 20.1 ml/min) (P < 0.01). In experiment I, the endothelium-dependent relaxations to acetylcholine, ADP, and A23187 were comparable between the right and left femoral arteries. In experiment II, the endothelium-independent contractions to acetylcholine and endothelium-dependent relaxations to ADP and A23187 were all comparable between the right and left vein grafts. In addition, the intimal thickening of the vein graft was comparable between the two groups (denervated, 95.6 +/- 10.8 microm; innervated, 105.0 +/- 15.0 microm). In both experiments, the NE-induced contractions and SNP-induced relaxations were closely similar between the two groups, irrespective of the flow change. These results suggest that lumbar sympathectomy does not alter endothelial function in terms of EDRF, although mean blood flow of the denervated femoral arteries and vein grafts was significantly higher than that of the innervated femoral arteries and vein grafts. These results suggest that continuous vasodilation following sympathectomy may be a more potent factor with respect to regulation of vascular tonus than physiologic regulation of EDRF.

Acetylcholine↗
PubMed1996

An in vitro invasion model for human renal cell carcinoma cell lines mimicking their metastatic abilities.

We developed a modified in vitro invasion assay system using monolayers of vascular endothelial cells. A type I collagen gel was formed in plastic dishes, and overlaid with type IV collagen. Calf pulmonary arterial endothelial (CPAE) cells were seeded onto these plates, and incubated until they reached confluence. Five human renal cell carcinoma cell lines with various metastatic potentials in vivo were then seeded on the monolayer CPAE cells, and their colony formation and invasion activities were examined for 9 days. At day 4, the highly metastatic cell lines increased the number of colony foci on monolayer CPAE cells several fold higher than their poorly metastatic counterpart. The horizontal spreading patterns were also different between poorly and highly metastatic cell lines. On day 9, the number of carcinoma foci that penetrated the monolayer of CPAE cells and type IV collagen sheets into type I collagen gels in highly metastatic cell lines greatly increased as compared with that of poorly metastatic cell lines. Our in vitro invasion assay using monolayer CPAE cells would be useful to evaluate protease activities and colony formation during invasion.

Animals↗
PubMed1996

Detection of circulating anti-p53 antibodies in patients with colorectal carcinoma and the antibody's relation to clinical factors.

PURPOSE: Mutation of the p53 tumor suppressor gene is the most common genetic alternation in colorectal carcinoma and is assessed mainly by molecular analysis of the gene sequence or by immunohistochemical analysis of p53 protein accumulation. Purpose of this study was to detect circulating antibody against p53 proteins in serum of patients with colorectal carcinoma and to evaluate its clinical significance. METHODS: We used immunoblotting techniques to detect circulating anti-p53 antibodies. Relationship among staging, immunohistochemical expression of p53 in the primary tumor, and serum carcinoembryonic antigen level was investigated. RESULTS: Circulating anti-p53 antibodies were detected in 32 (68 percent) of 47 patients. Antibody was found in patients at all clinical stages of disease. In 33 patients whose sera and primary tumor tissues were available for testing, 16 (48 percent) were positive for both circulating anti-p53 antibody and p53 expression in the tumor. The anti-p53 antibody test was positive in 78 and 56 percent of patients with high and normal serum carcinoembryonic antigen levels, respectively. CONCLUSION: Detection of anti-p53 antibodies may become a new diagnostic indicator of colorectal carcinomas.

Antibodies↗
PubMed1996

Use of a suture holder facilitates transanal anastomosis.

We report here that use of a suture holder facilitates transanal anastomosis in cases of total proctocolectomy or low rectal anastomosis. Feasible control of multiple interrupted suturing and unhampered visibility of the entire process are made possible with this approach.

Anal Canal↗
PubMed1996

Case report: primary CD30 (Ki-1)-positive anaplastic large cell lymphoma of the duodenum.

As recently described, Ki-1 anaplastic large cell lymphoma is a distinctive subtype of non-Hodgkin's lymphoma. We report a Ki-1 anaplastic large cell lymphoma of the duodenum in a 62-year-old man. He received modified CHOP therapy and was in complete remission at 18 months. To our knowledge, this is the first report of primary Ki-1 anaplastic large cell lymphoma of the duodenum.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1996

Diffuse ganglioneuromatosis with plexiform neurofibromas limited to the gastrointestinal tract involving a large segment of small intestine.

A rare case of diffuse ganglioneuromatosis with plexiform neurofibromas limited to the gastrointestinal tract in a 20-year-old man is reported. The patient had no cafe-au-lait spots or any apparent tumorous lesions affecting other organs. A fan-shaped resection of the mesentery, including 200cm of the ileum, together with ileocecal resection was done, and the diagnosis was histologically confirmed. The relationship between this benign tumor and other neurogenic disorders is discussed, along with a review of the literature. Long-term follow up of this patient is required because of the possible development of von Recklinghausen's disease or multiple endocrine neoplasia type IIb.

Adult↗