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K Murakami

Publications and source records attributed to K Murakami.

At least 415 records · Page 23Linked to original sources
PubMed1996

Clinicopathologic features of small pancreatic adenocarcinoma. A collective study.

BACKGROUND: Early diagnosis and complete removal of pancreatic adenocarcinoma (PC) is essential to improve its poor prognosis. It is necessary to find PC when it is small and at an early stage if surgical treatment is to be successful. This is an investigation of the clinicopathologic features of small PC. METHODS: Thirty-one resected and histopathologically examined cases of small PC, 2 cm or less in greatest dimension, were collected from 7 institutions between 1989 and 1994, and their clinicopathologic features were analyzed in detail. RESULTS: Eighteen patients (58.1%) had some symptoms or signs at the time of diagnosis, however, the other 13 (41.9%) had no symptoms. There was no sensitive blood test for the detection of small PC. The detection rates of the pancreatic tumor mass on ultrasonography, endoscopic ultrasonography, and computed tomography were 64.5% (20/31), 73.7% (14/19), and 64.5% (20/31), respectively. Only 13 patients (41.9%) were in International Union Against Cancer (UICC) Stage I, and the other 18 were in Stage III or IV due to lymph node metastasis or peritoneal dissemination. The overall 4-year postoperative survival rate was 54.5% and that of patients in Stage I was 77.9%. CONCLUSIONS: To detect a small PC, a thorough examination may be required in patients with slightly abnormal findings on laboratory tests or imaging modalities, even if the patient is asymptomatic. PC 2 cm or less and belonging to Stage I may be regarded as an early carcinoma, because of its good prognosis.

Adenocarcinoma↗
PubMed1996

Transcription factor recognition surface on the RNA polymerase alpha subunit is involved in contact with the DNA enhancer element.

The carboxy-terminal one-third of Escherichia coli RNA polymerase alpha subunit plays a key role in transcription regulation by a group of protein transcription factors and DNA enhancer (UP) elements. The roles of individual amino acid residues within this regulatory domain of the alpha subunit were examined after systematic mutagenesis of the putative contact regions (residues 258-275 and 297-298) for the cAMP receptor protein (CRP). The reconstituted RNA polymerases containing the mutant alpha subunits were examined for their response to transcription activation by cAMP-CRP and the rrnBP1 UP element. Mutations affecting CRP responsiveness were located on the surface of the putative CRP contact helix and most of these mutations also influenced the response to the rrnB UP element. These observations raise the possibility that the CRP contact surface is also involved in contact with the DNA UP element, although some amino acid residues within this region play different roles in molecular communication with CRP and the UP element. Among the amino acid residues constituting the contact surface, Arg265 was found to play a major role in response to both CRP and the DNA UP element. Judged by DNase I footprinting analysis, alpha mutants defective in transcription from the CRP-dependent lacP1 promoter showed decreased activity in the cooperative binding of CRP. Likewise, mutants defective in rrnBP1 transcription showed decreased binding to the UP element. The amino acid residues important for contact with both CRP and DNA are conserved in the alpha subunits of not only bacterial, but also chloroplast RNA polymerases.

Alanine↗
PubMed1996

Identification of an UP element within the IHF binding site at the PL1-PL2 tandem promoter of bacteriophage lambda.

An UP element defines a supplementary promoter element located upstream of the -35 region that stimulates transcription by interacting with the C-terminal domain of the RNA polymerase alpha subunit (alpha CTD). The alpha CTD also responds to various transcription activators, including the integration host factor protein, IHF, in the stimulation of the bacteriophage lambda PL promoter. PL consists of the tandem PL1-PL2 promoters where PL1 is stimulated and PL2 is repressed by IHF. We identified a functional UP element that binds the alpha subunit of RNA polymerase and is located in the region from -36 to -60 relative to the PL2 start site. PL2 expression requires the presence of the UP element and requires an intact alpha CTD. The UP element is nested within the DNA region protected by IHF against DNase I digestion. We used mutational analysis to identify the IHF recognition sequence which was found to be located downstream of the UP element, overlapping the -35 region of PL2. The possible function of the complex structure of the PL promoter is discussed.

Amino Acid Sequence↗
PubMed1996

A cis-acting DNA element located between TATA box and transcription initiation site is critical in response to regulatory sequences in human angiotensinogen gene.

The promoter of the human angiotensinogen (hAG) gene functioned in its own core promoter context but not when replaced with simian virus 40 (SV40) core promoter, suggesting the presence of a transcriptionally important cis-acting sequence. Electrophoretic mobility shift assays demonstrated that a ubiquitously expressed nuclear factor, AGCF1, bound to AGCE1 (hAG core promoter element 1; positions -25 to -1) located between the TATA box and transcription initiation site. Substitution mutation in AGCE1 which disrupted AGCF1 binding affected the promoter activity more severely than a nonsense mutation of the hAG TATA sequences did. When AGCE1 was placed at the downstream of SV40 core promoter, the responsiveness to hAG upstream region was significantly restored. Furthermore, mutation and in vivo competition experiments suggested that AGCF1 acts as a critical regulator of hAG transcription by mediating the activity of the hAG upstream and downstream enhancer elements. DNase I footprinting and UV cross-linking analyses showed that AGCF1 with apparent molecular masses of 31, 33, and 43 kDa as the components protected the region from -26 to -9 which partially overlapped with the TATA box consensus sequences. These findings indicate that AGCE1 in addition to the TATA box plays a key role in mediating the hAG regulatory elements.

Angiotensinogen↗
PubMed1996

An assay for lectin activity using microtiter plate with chemically immobilized carbohydrates.

A simple microtiter plate assay for lectins or carbohydrate-binding proteins was developed. The method utilizes carbohydrates immobilized in the wells of the microtiter plate containing primary amino groups on their surface. After incubation of the lectins, bound proteins are measured by the protein assay using the colloidal gold solution. When the binding of Ricinus communis agglutinin, concanavalin A, and wheat germ agglutinin was measured using the microtiter plate wells coated with lactose, mannose, or N-acetylglucosamine, binding of the lectins according to their known specificity was observed. Inhibition experiments with various carbohydrates also demonstrated that the specificity of lectins for different carbohydrates could be determined quantitatively. Since there is no need for modification of the lectins, such as biotinylation or conjugation with marker enzymes, the carbohydrate-binding ability of intact proteins can be easily determined by this method. When gel filtration fractions from the extract of the marine invertebrate Cucumaria echinata were subjected to this assay, different carbohydrate-binding activities were observed with different elution profiles, suggesting that this assay could also be widely applicable for the simultaneous detection of lectins from various sources.

Animals↗
PubMed1996

Dual termination modes of corticothalamic fibers originating from pyramids of layers 5 and 6 in cat visual cortical area 17.

Terminal morphology of corticothalamic fibers originating from cat area 17 was examined. Injections of an anterograde axonal tracer, phaseolus vulgaris leucoagglutinin (PHA-L), in area 17 resulted in labeling of small boutons in the dorsal lateral geniculate, perigeniculate, and thalamic reticular nuclei and in labeling of large boutons in the lateral nucleus of lateral posterior-pulvinar, ventral lateral geniculate, and pulvinar nuclei. Since it is well known that the dorsal geniculate nucleus is a major corticothalamic target for layer 6 pyramids and the lateral posterior-pulvinar complex is that for layer 5 pyramids, the findings indicate that layer 5 pyramids in cat area 17 project axons ending with large boutons, while layer 6 pyramids project those ending with small boutons.

Animals↗
PubMed1996

Pulmonary vascular injury induced by hemorrhagic shock is mediated by P-selectin in rats.

To investigate whether the P-selectin-mediated leukocyte adhesion to the endothelial cells is involved in pulmonary vascular injury after hemorrhagic shock, we examined the effect of an anti-P-selectin monoclonal antibody (MAb PB1.3) on the pulmonary accumulation of leukocytes and the subsequent pulmonary vascular injury observed after hemorrhagic shock in rats. Two hours after hemorrhagic shock, pulmonary accumulation of leukocytes, as evaluated by measuring myeloperoxidase activity, began to increase and peaked after 6 hours. Pulmonary vascular injury, as evaluated by the extravascular leakage of 125I-albumin, was significantly increased 6 hours after hemorrhagic shock. MAb PB1.3 significantly prevented both the pulmonary accumulation of leukocytes and subsequent pulmonary vascular injury. MAb PNB1.6, an anti-P-selectin monoclonal antibody incapable of inhibiting P-selectin-mediated leukocyte adhesion, did not prevent either of these effects. These observations strongly suggest that the pulmonary sequestration of leukocytes and the subsequent pulmonary vascular injury after hemorrhagic shock are mediated by P-selectin.

Animals↗
PubMed1996

Synaptic relationships between axon terminals from the mediodorsal thalamic nucleus and layer III pyramidal cells in the prelimbic cortex of the rat.

A combined study of anterograde axonal degeneration and Golgi electron microscopic technique was designed to examine the distribution and density of axon terminals from the mediodorsal thalamic nucleus (MD) over layer III pyramidal cells in the prelimbic cortex of the rat. The reconstructive analysis of serial ultrathin sections of gold-toned apical and basal dendrites of layer III pyramidal cells showed that degenerating thalamocortical axon terminals from MD formed asymmetrical synaptic contacts predominantly with dendritic spines of the identified basal dendrites as well as apical dendrites. There was little difference in the numerical density of thalamocortical synapses from MD per unit length of both apical and basal dendrites.

Animals↗
PubMed1996

Activated protein C attenuates endotoxin-induced pulmonary vascular injury by inhibiting activated leukocytes in rats.

We investigated the effect of activated protein C (APC) on lipopolysaccharide (LPS)-induced pulmonary vascular injury in rats to investigate the possible usefulness of APC as a treatment for adult respiratory distress syndrome. Intravenously administered LPS (5 mg/kg) significantly increased pulmonary vascular permeability. APC prevented the LPS-induced increase in pulmonary vascular permeability observed at 6 hours. Heparin plus antithrombin III (ATIII) and active site-blocked factor Xa (DEGR-Xa), a selective inhibitor of thrombin generation, inhibited LPS-induced coagulopathy but did not prevent LPS-induced pulmonary vascular injury. LPS-induced pulmonary vascular injury was significantly attenuated in rats with nitrogen mustard-induced leukocytopenia and in rats treated with ONO-5046, a potent granulocyte elastase inhibitor. Administration of LPS also increased pulmonary accumulation of leukocytes, as evaluated by measurement of myeloperoxidase activity in the lungs. APC significantly reduced LPS-induced increases in pulmonary accumulation of leukocytes at 1 hour. Neither ATIII plus heparin nor DEGR-Xa inhibited leukocyte accumulation. Active site-blocked APC (DIP-APC) prevented neither the LPS-induced pulmonary accumulation of leukocytes nor the LPS-induced increase in pulmonary vascular permeability. These results suggest that the mechanism of APC inhibition of LPS-induced pulmonary vascular injury was independent of its anticoagulant activity and was related to its ability to inhibit accumulation of leukocytes. In addition, these findings suggest that the serine protease activity of APC may be essential to its inhibitory effect on LPS-induced pulmonary accumulation of leukocytes and subsequent pulmonary vascular injury.

Amino Acid Chloromethyl Ketones↗
PubMed1996

Identification of regions in the human angiotensin II receptor type 1 responsible for Gi and Gq coupling by mutagenesis study.

Previous mutagenesis studies of angiotensin II (Ang II) receptor type 1 (AT1) have focused on determining the regions responsible for Gq coupling using the rat AT1 receptor. We created human AT1 receptor mutants, expressed them in COS-7 cells, and identified the domains crucial for Gi coupling as well as for Gq coupling. Substitution of Asp125, Arg126, Tyr127, and Met134 by Gly, Gly, Ala, and Ala in the highly conserved sequence of the second intracellular loop in most G protein-coupled receptors provided a mutant AT1 receptor which lost the ability to couple to both Gq and Gi with no impairment in its binding to Ang II. A truncated mutant lacking the carboxyl terminal 50 residues was completely deficient in coupling to Gi, whereas it retained full ability to bind to Gq, in contrast to the rat AT1 receptor. These findings demonstrate that the cytoplasmic tail in the human AT1 receptor is the determinant of specific Gi coupling.

1-Methyl-3-isobutylxanthine↗
PubMed1996

Determination of plasma soluble fibrin using a new ELISA method in patients with disseminated intravascular coagulation.

We measured plasma levels of soluble fibrin (SF) in 98 patients suspected of having disseminated intravascular coagulation (DIC) using a newly developed enzyme-linked immunosorbent assay (ELISA) and investigated the correlations between SF determinations and measurements of other hemostatic molecular markers to determine the diagnostic usefulness of determinations of SF. Patients were classified into four groups according to their clinical and laboratory findings: overt DIC (n =33), subclinical DIC (n =23) hypercoagulability (n =22), and non-DIC (n =20). SF levels were significantly higher in patients with overt DIC compared with the other three groups and were significantly higher in the subclinical DIC and hypercoagulability groups compared with the non-DIC patients. SF levels increased significantly with each increase in the clinical stage. Although levels of thrombin-antithrombin III complex (TAT), prothrombin fragment 1 + 2 (PF 1+2), cross-linked fibrin degradation products (XDP), and plasmin-antiplasmin complex (PAP) were significantly increased in patients with overt DIC compared with non-DIC patients, the values of these hemostatic molecular markers did not consistently show an increase in association with advances in the disease stage. Plasma levels of SF in patients with overt DIC showed a positive correlation with levels of TAT, XDP,and FDP(E), but not with PF1+2 and PAP. Analysis of receiver-operating characteristic curves showed that the sensitivity and specificity of SF were similar to those of XDP for diagnosis of DIC. The sensitivity and specificity of SF for diagnosis of overt DIC were both above 90% when the cut-off value was set at 65 mu g/ml.plasma levels of SF were also increased in patients with extravascular fibrin formation without DIC. Our findings suggest that measurement of plasma levels of SF by this ELISA method is useful for the diagnosis of DIC and the evaluation of the patient's clinical status.

Amino Acid Sequence↗
PubMed1996

Proto-oncogene expression in human glomerular diseases.

The expression of the protein products and mRNA of c-fos, c-myc, p53, and c-raf was examined in normal renal tissues and biopsy specimens from 73 patients with various glomerular diseases. Immunofluorescent staining showed that there were cell nuclei stained for c-Fos, c-Myc, and p53, and cytoplasm positive for c-Raf, in the glomeruli of patients with proliferative types of glomerulonephritis, including IgA nephritis and lupus nephritis, and in patients with focal glomerular sclerosis. Glomerular expression of c-fos and c-myc mRNA was detected by in situ hybridization. The number of proto-oncogene-positive glomerular cells was significantly higher in lupus nephritis, IgA nephritis, and focal segmental sclerosis, as compared with minimal change nephrotic syndrome and normal specimens. In IgA nephritis, the population of glomerular cells positive for c-Fos and c-Myc and the grade of c-Raf immunoreactivity were significantly correlated with the proportion of proliferating cell nuclear antigen (PCNA)-positive glomerular cells, with histological grading of mesangial hypercellularity and matrix increase, and with the magnitude of proteinuria. These data indicate that proto-oncogene expression is associated with mesangial proliferation and matrix expansion in proliferative types of glomerulonephritis and in focal glomerular sclerosis.

Cell Nucleus↗
PubMed1996

Clinical evaluation of chemosensitivity testing for patients with colorectal cancer using MTT assay.

PURPOSE: Colorectal cancer is one of the tumors most refractory to treatment by chemotherapy. The chemosensitivity test should be performed to individualize the chemotherapy for patients with colorectal cancer, which is less sensitive for anticancer drugs. The present study was designed to determine the chemosensitivity in fresh human colorectal cancer, using highly purified tumor cells, and the correlation of this sensitivity with clinical response. METHODS: We determined the chemosensitivity for cisplatin, mitomycin C, adriamycin, and 5-fluorouracil in vitro in 93 fresh human colorectal cancers using the MTT assay and performed chemotherapy according to results of the MTT assay. RESULTS: Inhibition rate of tumor cells for cisplatin was higher than those for other drugs. Fifteen patients who have evaluable lesions received chemotherapy according to results of the MTT assay. Clinical responses were obtained in 5 of 15 patients, and the inhibition rate for cisplatin was higher in responders than in nonresponders. CONCLUSIONS: It is suggested that the chemotherapy according to results of the MTT assay is effective in patients with colorectal cancer.

Adult↗
PubMed1996

Reconstruction with bilateral gluteus maximus myocutaneous rotation flap after wide local excision for perianal extramammary Paget's disease. Report of two cases.

PURPOSE: Extramammary Paget's disease is a rare dermatosis. Wide local excision is recommended in patients with perianal extramammary Paget's disease. After wide local excision, it is necessary to do reconstruction, with preservation of bowel function. We present here two cases of perianal Paget's disease, in which the patients were treated by reconstruction with bilateral gluteus maximus myocutaneous rotation flap after wide local excision. PATIENTS AND METHODS: A 55-year-old woman and 58-year-old man were admitted with anal pain and bleeding. Histologic examination of the perianal lesion revealed the presence of typical Paget's cells, and no underlying carcinoma and no distant metastasis was detected in either patient. Wide local excision, including the rectal mucosa, was performed, with reference to intraoperative frozen sections. Surgical defect was overlapped with bilateral gluteus maximus myocutaneous rotation flap, and the anus was reconstructed. RESULTS: Postoperative bowel function and quality of life were well preserved, and flaps healed satisfactorily. Patients have had no recurrence and have been able to return to work. CONCLUSION: Bilateral gluteus maximus rotation flap may be useful after wide local excision of perianal extramammary Paget's disease without underlying invasive carcinoma.

Anal Canal↗