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J Kuroki

Publications and source records attributed to J Kuroki.

At least 19 recordsLinked to original sources
PubMed2003

[Ruptured aortic arch aneurysm with hemorrhagic cardiac tamponade; report of a case].

The ruptured aortic arch aneurysm with cardiac tamponade is rare and has severely high mortality. We report a case of ruptured aortic arch aneurysm with cardiac tamponade. A 66-year-old man who had syncope attack was transferred to city hospital. Brain computed tomography (CT) showed no significant lesion and he admitted to our hospital for suspecting of aortic dissection. Chest CT showed ruptured aortic arch aneurysm and pericardial effusion. Emergent operation was done on the same day. It was found that the hematoma beneath the tunica adventitia existed at the distal arch and extended to the ascending aorta. Cardiac tamponade was caused by rupture of subadventitial hematoma in pericardial space. Aortic arch replacement was performed using selective cerebral perfusion under deep hypothermia. Postoperatively, he had no cerebral complication and was discharged uneventfully.

Aged↗
PubMed2000

Induction of tissue factor production but not the upregulation of adhesion molecule expression by ceramide in human vascular endothelial cells.

Binding of tumor necrosis factor-alpha (TNF-alpha) to p60 TNF-alpha receptor induces the activation of sphingomyelinase to generate ceramide, which in turn activates certain protein kinases and phosphatases, resulting in various TNF-alpha-mediated biological effects. We have investigated the role for the sphingomyelin/ceramide pathway in the TNF-alpha-induced upregulation of adhesion molecule expression and tissue factor production of human endothelial cells. TNF-alpha stimulated human umbilical vascular endothelial cells (HUVECs) to upregulate the expression of vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1) and HLA class I molecules in addition to the induction of procoagulant tissue factor production. C2-ceramide, a highly cell-permeable ceramide analog, was able to stimulate HUVECs to produce tissue factor activity as well as TNF-alpha. However, C2-ceramide did not stimulate HUVECs to upregulate the expression of VCAM-1, ICAM-1 and HLA class I molecules. These results suggest that there exist both the ceramide-dependent and -independent pathways in TNF-alpha signal transduction system in human vascular endothelial cells.

Antigens, CD↗
PubMed1999

Defective apoptotic signal transduction pathway downstream of caspase-3 in human B-lymphoma cells: A novel mechanism of nuclear apoptosis resistance.

Mitochondria play a central role in controlling apoptosis, and activation of the caspase cascade appears to be crucial event during the apoptotic process. Human B lymphoma Raji cells are resistant to nuclear apoptosis induced by various stimuli. Using this cell line, we have asked whether reduction of the mitochondrial transmembrane potential and activation of caspase-3 are sufficient to induce DNA fragmentation during the apoptotic process. After stimulation with cell-permeable C2-ceramide or mitochondrial permeability transition (PT) inducers, not only apoptosis-sensitive cell lines (HL-60, Jurkat, and Daudi cells), but also Raji cells showed reduction of the mitochondrial transmembrane potential (triangle uppsim), activation of caspase-3, and loss of clonogenic potential. However, Raji cells did not show detectable levels of nuclear apoptosis (DNA degradation). In a cell-free system, cell lysates from tetra-butylhydroperoxide (t-BHP)-treated HL-60 cells induced DNA degradation of Raji nuclei, whereas cell lysates from t-BHP-treated Raji cells failed to induce DNA degradation in either apoptosis-sensitive cell lines or apoptosis-resistant Raji cells. Cleavage of DFF-45, which is a downstream target molecule for caspase-3, was observed in Raji cells as well as in apoptosis-sensitive Daudi cells. These results indicate that there is a defective apoptotic pathway in the cytoplasm downstream of caspase-3 in Raji cells.

Alkylating Agents↗
PubMed1997

"Crushed glass" appearance of particles observed in roentgenograms after hysterosalpingography as an indicator of pelvic abnormalities.

OBJECTIVE: To evaluate the diagnostic value of the crushed glass appearance of particles observed on roentgenogram after hysterosalpingography in patients with pelvic abnormalities. DESIGN: Retrospective study of 32 patients whose roentgenogram had particles with a crushed glass appearance and 16 patients without crushed glass appearance, with laparoscopy conducted to determine the location and severity of the pelvic disease. SETTING: Fujita Health University Hospital, Aichi, Japan. PATIENT(S): A total of 240 patients underwent hysterosalpingography to determine the cause of infertility. MAIN OUTCOME MEASURE(S): We compared the location of the pelvic endometriosis and/or inflammation that was observed on roentgenogram as the crushed glass appearance versus definitive findings at laparoscopy. RESULT(S): A total of 30 of the 32 cases (93.8%) with the crushed glass appearance were confirmed as having pelvic abnormalities, such as endometriosis (73.3%) and pelvic inflammation (26.7%). The rate of the concurrence of the location of the crushed glass appearance observed on the film and that of the lesions verified by laparoscopy was 66.7%. Histopathological examination showed that specimens taken from endometriosis or inflammatory lesions that comprised the crushed glass appearance were lacking in epithelium in proportion to the size of the particles. CONCLUSION(S): Identification of the crushed glass appearance of particles was a useful noninvasive method of detecting pelvic abnormalities, such as pelvic endometriosis and inflammation, in infertile women.

Adult↗
PubMed1996

Dopamine D3 agonists disrupt social behavior in rats.

Behavioral studies were conducted in rats administered a selective D3 agonist, 7-hydroxy-N,N-di-n-propyl-2-aminotetralin (7-OH-DPAT) or 4aR, 10bR-(+)-trans-3,4,4a,10b-tetrahydro-4-propyl-2H,5H-[1] benzopyrano[4,3-b]-1,4-oxazin-9-ol (PD 128907). Both drugs induced disruption of huddling behavior in rats at doses that did not produce hyperlocomotion. The effects of the D3 agonists were dependent upon dosage and time after administration. These results suggest that D3 receptors are concerned with social interaction in rats.

Animals↗
PubMed1996

Transmembrane signaling through CD80 (B7-1) induces growth arrest and cell spreading of human B lymphocytes accompanied by protein tyrosine phosphorylation.

We addressed the issue of the role for CD80 (B7-1) expressed on human B cells in transmembrane signaling. Cross-linking of CD80 on B lymphoma Raji cells induced tyrosine phosphorylation in 160-, 120-, 55-, 46- and 44-kDa proteins, which was inhibited by genistein. CD80-mediated signaling resulted in the inhibition of DNA replication of B cells and induced the changes in morphology like macrophages or fibroblasts. This cell spreading was inhibited by the pre-treatment of the cells with genistein. These results suggest that the CD80 antigen is involved in transmembrane outside-in signaling in B cells and its biological effects appear to be mediated by tyrosine kinases.

B-Lymphocytes↗
PubMed1996

Cell-permeable ceramide inhibits the growth of B lymphoma Raji cells lacking TNF-alpha-receptors by inducing G0/G1 arrest but not apoptosis: a new model for dissecting cell-cycle arrest and apoptosis.

We examined the effects of a cell-permeable ceramide analog, C2-ceramide, on the growth of TNF-alpha-resistant B lymphoma Raji cells lacking TNF-alpha-receptors (TNF-R). C2-ceramide inhibited the clonal growth of not only TNF-alpha-sensitive myeloid leukemia cells (HL60 and U937) but also Raji cells. Following stimulation with C2-ceramide, HL60 and U937 cells showed apoptotic cell death, whereas Raji cells did not show a detectable level of apoptosis. However, a cell-cycle arrest in G0/G1 phase was observed in Raji cells after the treatment with C2-ceramide, which was accompanied by the dephosphorylation of retinoblastoma (RB) gene products and decreased expression of p53 proteins. Failure of C2-ceramide to induce apoptosis in Raji cells might be explained by the lack or low expression of apoptosis-inducing proteins by two lines of evidence: (1) Raji cells were resistant to apoptosis induced by ceramide even in the presence of transcription/translation inhibitors; (2) Bax protein expression was not detectable in Raji cells, although Bcl-2 protein expression in Raji cells was even less than that in HL60 and U937 cells. Moreover, protein kinase C (PKC), whose activation has been described to inhibit ceramide-induced apoptosis, inhibitor H-7 did not induce apoptotic cell death in Raji cells, suggesting that an imbalance between PKC and ceramide pathways is not the reason for the resistance of Raji cells against ceramide-induced apoptosis. Finally, ceramide-induced activation of nuclear factor kappaB (NF-kappaB) was observed in Raji cells as well as HL60 cells, indicating that activation of this molecule may not be specific for apoptosis. By using the present model, one can dissect cell-cycle arrest and apoptosis induced by ceramide.

Apoptosis↗
PubMed1995

Cloning, characterization, and tissue distribution of porcine SPAI, a protein with a transglutaminase substrate domain and the WAP motif.

The primary and gene structures and tissue distribution of porcine SPAI-2, a protein that belongs to the WAP protein superfamily and has a sodium-potassium ATPase inhibitory activity, were determined by molecular cloning and Northern analysis. A full-length cDNA clone was isolated from a porcine duodenum cDNA library. The cDNA insert encoded a polypeptide of 187 amino acids, which is composed of three domains: a hydrophobic presequence of 21 amino acids, a prosegment of 105 amino acids ending with Asp126, and the mature SPAI-2 sequence of 61 amino acids beginning with Pro127. The prosegment contained 16 repeats of a hexapeptide that is highly homologous to the repetitive sequence found in the transglutaminase domain of the human elafin, an elastase-specific inhibitor that also belongs to the WAP superfamily. The repetitive sequence was demonstrated to be a good substrate of transglutaminase using a recombinant preparation produced in Escherichia coli. A porcine genomic library was then screened for the SPAI gene. Characterization and sequencing of positive clones indicated that the gene is similar to the elafin gene, having 3 exons encoding the 5'-untranslated region and signal sequence, proSPAI, and 3'-untranslated region, respectively. Northern blot analysis revealed intestine-specific expression of SPAI mRNA; the message was especially abundant in the small intestine. ProSPAI was also found in the circulation. The similarity of proSPAI to elafin in the domain structure, the acid-labile nature of the cleavage site (Asp126-Pro127), and the fact that the major form of SPAI in the plasma is proSPAI strongly suggest that proSPAI is not the precursor but rather it is the native form of SPAI. Like elafin, therefore, SPAI appears to be a new type of biologically active substance with a transglutaminase substrate domain that acts as an anchoring sequence.

Amino Acid Sequence↗
PubMed1995

Granulocyte colony-stimulating factor downregulates allogeneic immune responses by posttranscriptional inhibition of tumor necrosis factor-alpha production.

We report downregulatory effects of granulocyte colony-stimulating factor (G-CSF) on allogeneic immune responses in vitro. G-CSF did not affect the proliferative response of peripheral blood mononuclear cells (PBMC) against allogeneic Daudi cells but did inhibit tumor necrosis factor (TNF)-alpha secretion. In contrast with G-CSF, granulocyte-macrophage (GM)-CSF and interleukin (IL)-3 enhanced alloactivation-induced TNF-alpha production. G-CSF-mediated suppression of TNF-alpha production was not affected by fixation of stimulators. G-CSF did not inhibit TNF-alpha mRNA expression or accelerate mRNA degradation, whereas pentoxifylline inhibited the expression of TNF-alpha mRNA. These results indicate that G-CSF acts directly on responder cells and modulates TNF-alpha production at posttranscriptional levels. Suppression of TNF-alpha secretion was accompanied by an increase of intracellular cyclic adenosine monophosphate (cAMP) concentration in alloactivated PBMC. The cell-permeable cAMP analogue, dibutyryl cAMP, suppressed TNF-alpha secretion without affecting TNF-alpha mRNA expression. G-CSF showed an inhibitory effect on the development of cytotoxic effector cells against allogeneic Daudi cells. Anti-TNF-alpha monoclonal antibody (MoAb) also inhibited the induction of cytolytic activity, and the inhibitory effects of G-CSF and anti-TNF-alpha MoAb on killer activity generation were overcome by adding exogenous TNF-alpha. Hence, impaired generation of cytolytic effector cells by G-CSF is believed to be the result of reduced TNF-alpha production. Collectively, the results described above suggest that G-CSF downregulates allogeneic immune responses by posttranscriptionally inhibiting TNF-alpha production.

Antibodies, Monoclonal↗
PubMed1995

Signal transduction by B7/BB1 expressed on activated T lymphocytes: cross-linking of B7/BB1 induces protein tyrosine phosphorylation and synergizes with signalling through T-cell receptor/CD3.

We report here that B7/BB1 molecules expressed on activated T lymphocytes are involved in signal transduction. Anti-B7/BB1 monoclonal antibody (mAb) enhanced allogeneic proliferative responses against three different B lymphoma lines in a dose-dependent manner, while the same mAb inhibited T-cell response against allogeneic T cells expressing B7/BB1. Induction of B7/BB1 expression on T cells with allogeneic stimulation was confirmed by flow cytometric analysis. With the purified preactivated T cells as responder cells, anti-B7/BB1 mAb costimulated these primed T cells with coimmobilized anti-CD3 mAb. Moreover, cross-linking of B7/BB1 molecules induced protein tyrosine phosphorylation in preactivated T cells with a phosphorylation pattern distinct from those induced by signalling through other T-cell molecules. These results suggest that B7/BB1 molecules function not only as costimulatory ligands expressed on antigen-presenting cells but as receptors on T cells to transduce the costimulatory signals into the cells and may play a role for T-cell-T-cell interactions leading to clonal expansion of activated T lymphocytes. However, the physiological relevance of our finding remains to be explored.

Antibodies, Monoclonal↗
PubMed1995

Autoantibodies against 70-kDa heat shock proteins (HSP70) in allogeneic bone marrow transplant recipients.

We report that autoantibodies against the 70-kDa heat shock protein family (HSP70) were detected in allogeneic bone marrow transplant recipients. Antibodies to HSP70 family proteins were detected in three out of 14 recipients of an allogeneic marrow graft but in none of the seven patients receiving autologous peripheral blood stem cell transplant (PBSCT). Immunoblotting analysis combined with two-dimensional SDS-PAGE revealed that these patients had antibodies to a constitutive 73-kDa/pI 5.5 heat shock protein (HSP73) and to a stress-inducible 72-kDa/pI 5.6 protein (HSP72). This is the first report, to our knowledge, describing the presence of autoantibody against HSP73 in allogeneic marrow transplant recipients. Our results may provide additional insight into the etiology and the pathophysiology of allogeneic transplant-related disorders.

Adolescent↗
PubMed1994

Successful vidarabine therapy for adenovirus type 11-associated acute hemorrhagic cystitis after allogeneic bone marrow transplantation.

A 36-year-old man underwent an allogeneic BMT for acute lymphoblastic leukemia. Eighteen days later the patient developed sudden onset of painful, gross hematuria due to adenovirus type 11 infection that did not respond to conservative therapy. There was an increase in serum creatinine levels and delayed recovery of the platelet count, associated with hemophagocytosis. After obtaining informed consent, vidarabine, which has been shown to be active against adenovirus in vitro, was started. The patient's symptoms improved within a few days of vidarabine therapy and urine cultures for adenovirus became negative. No serious adverse effects were observed. Vidarabine may be one therapeutic option in life-threatening adenovirus infection.

Adenovirus Infections, Human↗
PubMed1992

Primary structure of the human elafin precursor preproelafin deduced from the nucleotide sequence of its gene and the presence of unique repetitive sequences in the prosegment.

The human elafin gene was cloned and its entire nucleotide sequence was determined to deduce the amino acid sequence for the precursor of elafin, an elastase-specific inhibitor. The gene spans approximately 1.7 kb and is divided into 3 exons. The gene product preproelafin consists of 117 amino acids: the initiator Met, a putative 25-amino acid signal peptide, a pro-sequence of about 34 amino acids, and the C-terminal 57 amino acids for mature elafin. Possible covalent clotting of the prosegment and its physiological significance have been pointed out based on a remarkable sequence similarity between the pro-sequence and the guinea pig seminal clotting protein SVP-1.

Amino Acid Sequence↗
PubMed1991

[Electrolyte abnormality and renal insufficiency in malignant lymphoma; clinical and pathological analysis in 123 cases].

The clinical studies about the electrolyte abnormality (EA) in patients with malignant lymphoma (ML) are rarely reported. We analyzed the EA and renal insufficiency in 123 patients with ML between June. 1976 and Jan. 1989; 8 patients with Hodgkin's disease, and 115 patients with non-Hodgkin's lymphoma (NHL). Before treatment, the incidence of the EA was 24.2% and hypercalcemia, hypocalcemia, and hyperkalemia were predominant. After treatment it became to 74.7% and the number of hyponatremia and hypokalemia increased. The incidence of proteinuria and renal insufficiency (serum creatinine above 1.5 mg/dl), were 7.3% and 2.4% before treatment, and became to 26.8% and 26.8% after treatment, respectively. There was a significant difference between two groups with and without the EA before treatment as for serum lactate dehydrogenase (LDH) levels (p less than 0.01), clinical stages (p less than 0.05) and the incidence of bone marrow involvement (p less than 0.01). In 34 autopsied cases, 3 cases showed massive renal involvement and about a half of cases showed various renal changes. The EA before treatment was caused by extrarenal factors, because the incidence of proteinuria and renal insufficiency were almost same to healthy controls. And renal factors play an important role on the E.A after treatment. Above results suggest that the EA before treatment indicates the progress of malignant lymphoma and the EA after treatment means not only the progress of the disease but also therapy-related renal damages.

Adult↗
PubMed1991

[Acute toxicity, inductive effects of liver enzymes and distribution in the liver of 1,2,3,7,8-pentachlorodibenzo-p-dioxin in rats].

Acute toxicity, inductive effects of liver enzymes and liver persistency of 1,2,3,7,8-pentachlorodibenzo-p-dioxin (PenCDD) were compared with those of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) using male Wistar rats. 1,2,3,7,8-PenCDD treatment at a dose of 0.1 mumol/kg resulted in significant depression of growth of rats from a day to 28 days after treatment. However, the effect was relatively less than that of 2,3,7,8-TCDD. On 5 days, similarly to 2,3,7,8-TCDD-treated group, liver hypertrophy and thymic atrophy were observed in 1,2,3,7,8-PenCDD-treated groups. In addition, 1,2,3,7,8-PenCDD showed potent 3-methylcholanthrene-type inducing ability. For example, the activities of benzo(a)pyrene 3-hydroxylase and DT-diaphorase were 25-fold and 10-fold of control, respectively. On 30 days, about 50% of the inductive effects on 5 days were maintained in both 1,2,3,7,8-PenCDD- and 2,3,7,8-TCDD-treated groups. Amount of 1,2,3,7,8-PenCDD distributed to the liver on 5 days was about 80-90% of dose and was about 1.5 times greater than that of 2,3,7,8-TCDD. About 50% of dose of 1,2,3,7,8-PenCDD remained even on 30 days after treatment. From these results, it is suggested that 1,2,3,7,8-PenCDD possessing the potent acute toxicity comparable to 2,3,7,8-TCDD and higher persistency in the liver might be more important than 2,3,7,8-TCDD in terms of the chronic toxicity.

Animals↗
PubMed1990

Four disulfide bonds' allocation of Na+, K(+)-ATPase inhibitor (SPAI).

We have recently reported the primary structures of the three unique peptide inhibitors (SPAI-1, -2, and -3) against Na+, K(+)-ATPase which contained four disulfide bridges in common (Biochem. Biophys. Res. Commun. 164, 496 (1989)). The disulfide connectivities of SPAI were determined by the combination of amino acid analyses with the direct application to a gas-phase sequencer of its proteolytic fragments. The disulfide bond was identified by detection of phenylthiohydantoin derivatives of cystine and its decomposed product dehydroalanine. The four cysteine pairs were disclosed to be Cys20 to Cys49, Cys27 to Cys53, Cys36 to Cys48, and Cys42 to Cys57, all linked by disulfide bridge formation. The allocation pattern of these disulfide bonds was the same as that recently reported for human mucous proteinase inhibitor (EMBO J. 7, 345 (1988], though SPAI showed no proteinase inhibitory activity at all.

Amino Acid Sequence↗
PubMed1989

Novel peptide inhibitor (SPAI) of Na+, K+-ATPase from porcine intestine.

Three unique inhibitors (SPAI-1, -+2, and -3) were first purified from porcine duodenal extract based on the Na+, K+-ATPase inhibitory activity. These peptide inhibitors had four disulfide bridges in common. The sequencing results of their S-carboxymethyl derivatives, lysilendopeptidase fragments, and chymotryptic peptides disclosed their entire primary structures. Both SPAI-2 and -3 consisted of 61 amino acids, respectively, and had almost the same sequences except for two amino acid substitutions, while SPAI-1 was found to lack the N-terminal twelve amino acid sequence of SPAI-2. The kinetics study revealed that SPAIs inhibited Na+, K+-ATPase by the competitive mode against Na+ and were uncompetitive with K+.

Amino Acid Sequence↗