Biomedical subjects

K Murata

Publications and source records attributed to K Murata.

At least 127 records · Page 7Linked to original sources

PubMed2000

Suppression by apigenin of peritoneal metastasis of intestinal adenocarcinomas induced by azoxymethane in Wistar rats.

The effect of a naturally occurring flavonoid apigenin on the development of bombesin-enhanced peritoneal metastasis from intestinal adenocarcinomas induced by azoxymethane was investigated in male Wistar rats. From the start of the experiment, rats were given weekly s.c. injections of azoxymethane (7.4 mg/kg body weight) for 10 weeks and s.c. injection of bombesin (40 microg/kg body weight) every other day, and from week 16, s.c. injections of apigenin (0.75 or 1.5 mg/kg body weight) every other day until the end of the experiment in week 45. Bombesin significantly increased the incidence of intestinal tumors and cancer metastasis to the peritoneum in week 45. It also significantly increased the labeling index of intestinal cancers. Although administration of apigenin at either dose with bombesin had little or no effect on the enhancement of intestinal carcinogenesis by bombesin, the location, histologic type, depth of involvement, infiltrating growth patterns and labeling index, it was found to decrease significantly the incidence of cancer metastasis. Apigenin significantly decreased the incidence of lymphatic vessel invasion of adenocarcinomas, which was enhanced by bombesin. In vitro experiments revealed that apigenin inhibited bombesin-enhanced phosphorylation of mitogen-activated protein kinase (MAPK), but not matrix metalloprotease (MMP)-9 expression. Our findings indicate that apigenin inhibits cancer metastasis through inhibition of phosphorylation of MAPK.

Adenocarcinoma↗

PubMed2000

Angiotropic lymphoma: proliferation of B cells in the capillaries of cutaneous angiomas.

We report a 52-year-old patient with cutaneous angiomas on the trunk in association with angiotropic lymphoma involving the nervous system. The lesional skin showed proliferation of atypical B cells in the capillaries. The diagnosis of angiotropic lymphoma with neurological deficits is often difficult before death. Thus, skin biopsy in this case proved to be diagnostic of the central nervous system disease without the risk of brain biopsy. The diagnosis of angiotropic lymphoma in the future may be achievable by biopsy of coincidental angiomas.

Biopsy↗

PubMed2000

Synchronous esophageal and renal cell carcinoma.

Multiple cancer associated with esophageal cancer is not uncommon; however, synchronous esophageal and renal cell carcinoma is very rare. Only three cases have been reported to date, and one of these patients was treated in our institution. We have since successfully treated another patient. Here, we report the two cases treated in our institution. In the first case, esophagectomy, nephrectomy, and reconstruction using a gastric tube were carried out in one stage. Post-operative renal function was temporarily impaired by the complications of anastomotic leakage and pyothorax but no hemodialysis was needed. In the second case, as the patient had undergone distal gastrectomy because of gastric cancer, we chose a two-stage operation, i.e. esophagectomy and nephrectomy as the first stage, followed by reconstruction using a colon substitute after 4 weeks, resulting in only slight renal dysfunction. Patients 1 and 2 are alive and well 7 years and 2 years after the operations respectively.

Aged↗

PubMed2000

Troglitazone reduces plasma levels of tumour necrosis factor-alpha in obese patients with type 2 diabetes.

We evaluated the effect of troglitazone (given orally 400 mg/day) on glucose intolerance and on the plasma levels of tumour necrosis factor-alpha (TNF-alpha) in 12 obese patients with type 2 diabetes for 12 weeks. Troglitazone significantly decreased fasting plasma glucose, serum C-peptide, serum insulin and HbA1c levels. Plasma levels of TNF-alpha were significantly reduced by troglitazone administered for 8 and 12 weeks. Troglitazone administration significantly improved insulin resistance, but did not affect pancreatic beta-cell function as evaluated by the homeostasis model assessment (HOMA). In the present study, we reported for the first time that troglitazone administration significantly reduces plasma levels of TNF-alpha in obese patients with type 2 diabetes.

Blood Glucose↗

PubMed2000

Increased expression of S100A6 at the invading fronts of the primary lesion and liver metastasis in patients with colorectal adenocarcinoma.

Two members of the S100 gene family, S100A6 and S100A4 have been suggested to be associated with cancer invasion and metastasis. To study their involvement in the malignancy of human colorectal adenocarcinoma, we examined the protein expression levels of S100A6 and S100A4 in the primary colorectal adenocarcinoma (T) and paired adjacent normal colorectal mucosa (N) from 12 cases, quantitatively by Western blot analysis. In 11 of 12 and seven of 12 cases, S100A6 and S100A4 expression levels were higher in T than in N, respectively. Average S100A6 level in T was significantly higher than in N (about x 2.3;P = 0.001), whereas average S100A4 level in T was not. When S100A6 expression levels in three sets of matched samples of primary colorectal adenocarcinoma (T) and liver metastasis (M) were examined, S100A6 levels were higher in M than in T in two of three cases. Immunohistochemical analysis using monoclonal anti-S100A6 antibody showed that 23 of 42 (55%) primary colorectal adenocarcinoma and 15 of 16 (94%) liver metastasis specimens were positively stained. S100A6 immunostaining of primary colorectal adenocarcinomas was significantly more intense in the invading fronts with structural atypia than in central portions with glandular structure (P< 0.0001), whereas Ki-67 staining (a growth marker) was similar in these two portions. Interestingly, S100A6 and Ki-67 immunostaining patterns in liver metastases were also the same as in primary lesions. These results suggest that S100A6 is involved in the invasive process of human colorectal adenocarcinomas and that S100A6 expression levels decrease when carcinoma cells form glandular structure again at the central portions of metastatic nodules.

Adenocarcinoma↗

PubMed2000

Laparoscopic findings in an adult case of Alagille syndrome.

Laparoscopic findings in a 32-year-old woman presenting with Alagille syndrome are reported. The liver surface showed a segmental whitish discoloration on the surface of both lobes with a transverse sulcus which was not stained enough after an intravenous injection of indocyanine green (ICG). These findings suggested an acquired bile duct injury in addition to a congenital anomaly of the bile duct in this patient.

Adult↗

PubMed2000

Inner ear anomaly of three-dimensional computed tomography: computed tomographic attenuation and image changes.

With regard to image diagnosis of inner ear anomalies, three-dimensional computed tomography (3D-CT) is useful in obtaining very realistic images that are unmatched by 2D-CT. Unlike the step scanning in the existing 2D-CT, in helical 3D-CT, scanning is performed in a spiral motion by continuously rotating the scanner and moving the table along the body axis at a constant speed. As a result, data obtained by this CT are continuous and very smooth curves can be obtained. Among the data, the CT attenuation determines the quality of the final 3D images. In the present paper, the usefulness of 3D-CT was investigated in a case with Mondini-type inner ear malformation.

Adult↗

PubMed2000

Three-dimensional magnetic resonance imaging findings of inner ear anomaly.

Using three-dimensional magnetic resonance imaging (3D-MRI), the membranous labyrinth was examined in normal cases and in a case with bilateral Mondini-type inner ear malformations. Both ears were also examined by high-resolution computed tomography (CT) of the temporal bone. 3D-MRI provided more detail than findings obtained by conventional high-resolution CT and it enabled 3D observations to be made. Detailed examination of maximum intensity projection images along the cochlea axis revealed the cochlear turns in three dimensions.

Adolescent↗

PubMed2000

Expression of the co-stimulatory molecule BB-1, the ligands CTLA-4 and CD28 and their mRNAs in chronic inflammatory demyelinating polyneuropathy.

To examine whether the Schwann cells in patients with autoimmune neuropathies have the potential to behave as professional antigen-presenting cells, we investigated the expression of the co-stimulatory molecules BB-1, B7-1 (CD80) B7-2 (CD86) and their counter-receptors CD28 or CTLA-4 (CD152) at the protein and mRNA levels in sural nerve biopsies of patients with chronic inflammatory demyelinating polyneuropathy (CIDP), CIDP associated with human immunodeficiency virus infection (HIV-CIDP), IgM paraproteinaemic neuropathy and normal or non-immune axonal neuropathy. In single- and double-labelling experiments, we used the S-100 antigen as a pan-Schwann cell marker, myelin-associated glycoprotein as a marker for myelinating Schwann cells and the fibrillary acidic protein as a marker for unmyelinating Schwann cells. The expression of the B7 family of molecules was limited to BB-1 and was observed only on the Schwann cells. There was constitutive expression of BB-1 on unmyelinating Schwann cells in all nerves studied. However, in CIDP and HIV-CIDP, but not the other diseases, there was prominent upregulation of BB-1 on the myelinating Schwann cells. The endoneurial T cells in the proximity of BB-1-positive Schwann cells expressed the CD28 or CTLA-4 counter-receptors. Reverse transcription-polymerase chain reaction confirmed that these ligands were upregulated only in CIDP. Because the myelinating BB-1-positive Schwann cells expressed HLA-DR antigen, the findings indicate that, in CIDP, Schwann cells possess the necessary markers to function as antigen-presenting cells.

Abatacept↗

PubMed2000

Effect of grepafloxacin on cytokine production in vitro.

The effect of a new quinolone antibacterial agent, grepafloxacin, on the production of cytokines was investigated using lipopolysaccharide-stimulated human peripheral blood cells. Grepafloxacin 1-30 mg/L inhibited the production of interleukin 1alpha (IL-1alpha) and IL-1beta, and the expression of IL-1alpha, IL-1beta, tumour necrosis factor alpha (TNFalpha), IL-6 and IL-8 mRNA. These results suggest that the inhibitory effect of grepafloxacin is exerted, in part, at the gene transcription level.

Anti-Infective Agents↗

PubMed2000

Use of a cauterizing laparoscopic linear stapler in intestinal anastomosis.

The purpose of this study was to assess the usefulness of a cauterizing laparoscopic linear stapler for intestinal anastomosis. In a porcine model, intestinal anastomoses performed with a standard laparoscopic linear stapler, a cauterizing laparoscopic linear stapler (RF stapler), and a two-layer, hand-sewn technique were compared by measuring bursting pressures at 4 and 7 days after surgery. During surgery, the RF stapler provided better hemostasis than the regular stapler for mesenteric transection. At 4 days, one leak occurred in the RF stapler group, and the bursting pressure in the RF stapler group was significantly lower than the bursting pressures in the regular stapler group and the hand-sewn group. In addition, the bursting pressure was significantly greater in the hand-sewn group than in the regular stapler group at 4 days. By 7 days, there were no differences in bursting pressure among the groups. We recommend that the RF stapler not be used for intestinal anastomosis. However, the device may be beneficial for controlling vasculature.

Anastomosis, Surgical↗

PubMed2000

A novel bacterial ATP-binding cassette transporter system that allows uptake of macromolecules.

A gram-negative bacterium, Sphingomonas sp. strain A1, isolated as a producer of alginate lyase, has a characteristic cell envelope structure and forms a mouth-like pit on its surface. The pit is produced only when the cells have to incorporate and assimilate alginate. An alginate uptake-deficient mutant was derived from cells of strain A1. One open reading frame, algS (1,089 bp), exhibiting homology to the bacterial ATP-binding domain of an ABC transporter, was cloned as a fragment complementing the mutation. algS was followed by two open reading frames, algM1 (972 bp) and algM2 (879 bp), which exhibit homology with the transmembrane permeases of ABC transporters. Disruption of algS of strain A1 resulted in the failure to incorporate alginate and to form a pit. Hexahistidine-tagged AlgS protein (AlgS(His6)) overexpressed in Escherichia coli and purified by Ni(2+) affinity column chromatography showed ATPase activity. Based on these results, we propose the occurrence of a novel pit-dependent ABC transporter system that allows the uptake of macromolecules.

ATP-Binding Cassette Transporters↗

PubMed2000

Molecular identification of oligoalginate lyase of Sphingomonas sp. strain A1 as one of the enzymes required for complete depolymerization of alginate.

A bacterium, Sphingomonas sp. strain A1, can incorporate alginate into cells through a novel ABC (ATP-binding cassette) transporter system specific to the macromolecule. The transported alginate is depolymerized to di- and trisaccharides by three kinds of cytoplasmic alginate lyases (A1-I [66 kDa], A1-II [25 kDa], and A1-III [40 kDa]) generated from a single precursor through posttranslational autoprocessing. The resultant alginate oligosaccharides were degraded to monosaccharides by cytoplasmic oligoalginate lyase. The enzyme and its gene were isolated from the bacterial cells grown in the presence of alginate. The purified enzyme was a monomer with a molecular mass of 85 kDa and cleaved glycosidic bonds not only in oligosaccharides produced from alginate by alginate lyases but also in polysaccharides (alginate, polymannuronate, and polyguluronate) most efficiently at pH 8.0 and 37 degrees C. The reaction catalyzed by the oligoalginate lyase was exolytic and thought to play an important role in the complete depolymerization of alginate in Sphingomonas sp. strain A1. The gene for this novel enzyme consisted of an open reading frame of 2,286 bp encoding a polypeptide with a molecular weight of 86,543 and was located downstream of the genes coding for the precursor of alginate lyases (aly) and the ABC transporter (algS, algM1, and algM2). This result indicates that the genes for proteins required for the transport and complete depolymerization of alginate are assembled to form a cluster.

Alginates↗

PubMed2000

Hgs (Hrs), a FYVE domain protein, is involved in Smad signaling through cooperation with SARA.

Smad proteins are effector molecules that transmit signals from the receptors for the transforming growth factor beta (TGF-beta) superfamily to the nucleus; of the Smad proteins, Smad2 and Smad4 are essential components for mouse early embryogenesis. We demonstrated that Hgs, a FYVE domain protein, binds to Smad2 in its C-terminal half and cooperates with another FYVE domain protein, the Smad anchor for receptor activation (SARA), to stimulate activin receptor-mediated signaling through efficient recruitment of Smad2 to the receptor. Furthermore, a LacZ knock-in allele of the C-terminal half-deletion mutant of mouse Hgs was created by gene targeting. The introduced mutation causes an embryonic lethality between embryonic days 8.5 and 10.5. Mutant cells showed significantly decreased responses to stimulation with activin and TGF-beta. These findings suggest that the two FYVE domain proteins, Hgs and SARA, are prerequisites for receptor-mediated activation of Smad2.

Activin Receptors↗

PubMed2000

Inhibition of baroreflex vagal bradycardia by activation of the rostral ventrolateral medulla in rats.

In stressful conditions, baroreflex vagal bradycardia (BVB) is often suppressed while blood pressure is increased. To address the role of the rostral ventrolateral medulla (RVL), a principal source of sympathetic tone, in inhibition of BVB, we microinjected DL-homocysteic acid (DLH, 6 nmol) into the RVL of chloralose-urethan-anesthetized, sinoaortic-denervated rats to examine the effect on BVB. The BVB was provoked by electrical stimulation of the aortic depressor nerve ipsilateral to the injection sites. DLH microinjection was found to suppress BVB while increasing blood pressure. The inhibition of BVB was observed even during the early phase in which DLH transiently suppressed central inspiratory activity. The inhibition was not affected either by upper spinal cord transection or suprapontine decerebration. Similar results were obtained by microinjection of bicuculline methiodide (160 pmol), a GABA antagonist, into the RVL of carotid sinus nerve-preserved rats due to withdrawal of a tonic GABA-mediated, inhibitory influence including the input from arterial baroreceptors. In conclusion, activation of the RVL inhibits BVB at brain stem level independently of central inspiratory drive.

Animals↗

PubMed2000

Usefulness of transesophageal echocardiographic monitoring in transluminal endovascular stent-graft repair for thoracic aortic aneurysm.

The endovascular stent-graft has been devised for the treatment of thoracic aortic aneurysm (TAA) to reduce complications associated with conventional surgical repair. The present study assessed the usefulness of transesophageal echocardiography (TEE) for intra- and post-operative examinations in patients treated with transluminal endovascular stent-graft repair for TAA. Nine patients with TAA and 2 with chronic type B aortic dissection were studied. Immediately after stent-graft deployment, perigraft leakage was evaluated with both intraoperative TEE and aortography. In 9 of 11 patients, TEE and aortography immediately after stent-graft deployment revealed the same perigraft leakage results. TEE might therefore be useful for evaluating perigraft leakage and thrombus formation after stent-graft repair for TAA and could be an alternative to aortography, especially for patients with renal dysfunction who have the possibility of contrast agent-induced complications.

Aged↗

PubMed2000

Determination of the complete nucleotide sequence and haplotypes in the D-loop region of the mitochondrial genome in the oriental white stork, Ciconia boyciana.

The complete nucleotide sequence of the mitochondrial genome of the Oriental white stork, Ciconia boyciana, has been determined from captive storks by a novel method incorporating Long PCR and shotgun sequencing. 13 protein-coding genes, two ribosomal RNA genes and 22 transfer RNA genes were identified as in other vertebrate mitochondrial genomes. The position and direction of the NADH6 and tRNA-Glu genes were the same as previously reported for avian mitochondrial genomes. A 71 bp direct repeat and long CAAA repeat sequences were found at the 3' end of the D-loop region, together with SCB-1, SCB-2, SCB-3, and three TAS sequences. Direct sequencing of the PCR fragments in the D-loop region in 26 captive Oriental white storks originating from Japan, China, and Russia revealed nucleotide differences at 18 sites along 1,248 bp, and a total of nine haplotypes have been identified. It was found that one pair of individuals in the Japanese captive breeding program were of the same haplotype, suggesting that they were caught from the same nest. The pair has since been dissolved in consideration of the possibility of inbreeding depression.

Animals↗

PubMed2000

Safety assessment of rice genetically modified with soybean glycinin by feeding studies on rats.

Feeding studies on rice genetically modified with soybean glycinin were performed on rats for four weeks. The rats were divided into three groups, each being fed on (I) only a commercial diet, (II) this diet plus control rice and (III) this diet plus rice genetically modified with glycinin. The rats were fed with 10 g/kg-weight of rice every day by oral administration. During the test period, the rats in every group grew well without marked differences in appearance, food intake, body weight, or cumulative body weight gain. There were also no significant differences in the blood count, blood composition or internal organ weights among the rats. Necropsy at the end of the experiment indicated neither pathological symptoms nor histopathological abnormalities in the liver and kidney. Judging from these results, the rice genetically modified with glycinin is considered to have been essentially the same in nutritional and biochemical characteristics as the control rice.

Animal Feed↗