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Biomedical subjects

T Kono

Publications and source records attributed to T Kono.

At least 109 records · Page 6Linked to original sources
PubMed1998

Neuropeptide Y stimulates bile secretion via Y1 receptor in the left dorsal vagal complex in rats.

Neuropeptide Y (NPY) injected into the cerebrospinal fluid and the left dorsal vagal complex enhances bile acid-independent and bicarbonate-dependent bile secretion through vagal muscarinic pathways in animal models. NPY binds to and activates six different receptor subtypes, and NPY Y1 and Y2 receptors are distributed in the dorsal vagal complex. We sought to determine which NPY receptor subtypes are involved in central stimulation of bile secretion by examining the effect of microinjection of specific NPY receptor agonists into the dorsal vagal complex. The bile duct was cannulated in urethane-anesthetized and bile acid-compensated rats. After measuring basal secretion, NPY, peptide YY (PYY), [Leu31, Pro34]NPY, NPY(13-36), or NPY(3-36) was microinjected into the either right or left dorsal vagal complex and bile secretion was observed for 100 minutes. Hepatic branch vagotomy was performed 2 hours before the peptide injection. Microinjection of NPY and PYY (8 pmol) into the left dorsal vagal complex increased bile secretion. [Leu31, Pro34]NPY microinjected into the left dorsal vagal complex also dose-dependently (1-8 pmol) stimulated bile acid-independent and bicarbonate-dependent bile secretion. Microinjection of NPY(13-36) into the left dorsal vagal complex did not stimulate and NPY(3-36) dose-dependently inhibited bile secretion. Stimulation of bile secretion by [Leu31, Pro34]NPY was abolished by hepatic branch vagotomy. NPY acts in the left dorsal vagal complex to stimulate bile acid-independent and bicarbonate-dependent bile secretion via Y1 receptor subtype.

Animals↗
PubMed1998

Nitric oxide release from the liver surface to the intraabdominal cavity during acute endotoxemia in rats.

Nitric oxide (NO) is produced by the liver during lipopolysaccharide (LPS)-induced endotoxemia. The aim of this study was to examine whether NO, which is produced in the liver, is released from the liver surface to the intraabdominal cavity during endotoxemia. NO was quantitatively determined by chemiluminescence and a newly developed gas purge technique was used to directly measure NO released from the liver surface and the intraabdominal cavity of rats before and after LPS (0.1 mg/kg, intraperitoneally) or saline administration. The expression of inducible NO synthase (iNOS) mRNA in the liver was detected by Northern blot analysis. NO levels from both the liver surface and in the intraabdominal cavity were elevated at 2 h after LPS injection and peaked at 10 h and both the time course of NO level were well correlated with each other. Both NO levels were below the detectable range before LPS and after saline administration. Inducible NOS mRNA in the liver exhibited a sharp increase to a maximum level at 4 h after LPS injection. The present study indicates that the hepatic NO, which might have been produced by iNOS in the liver, is released from the liver surface to the intraabdominal cavity during endotoxemia.

Acute Disease↗
PubMed1998

[A case of complete circumferential aortic rupture due to blunt chest trauma].

A case of complete circumferential rupture of the thoracic aorta due to blunt chest trauma is presented. A 30-year-old man was admitted after a traffic accident. The admission chest X-ray film demonstrated mediastinal widening. About 6 hours after the traffic accident, chest CT scanning demonstrated mediastinal hematoma, left pleural effusion and partial aortic dissection. Diagnoses of aortic rupture and liver injury were made, and surgery for the thoracic aorta was performed immediately. The aorta was found to be completely disrupted for the length of 2 cm, and a vascular prosthesis was interposed between the two ends of the aorta under partial cardiopulmonary bypass. We conclude that the enhanced chest CT scanning is helpful for diagnosis, and that if other organ injuries are not severe, the emergency operation should be performed.

Accidents, Traffic↗
PubMed1998

Metastatic malignant meningioma of the liver with hypoglycemia: report of a case.

We herein present the case of a 68-year-old male who suffered an episode of hypoglycemic shock 2 years after undergoing total removal of a bifrontal parasagittal malignant meningioma. Imaging studies revealed three giant hypervascular tumors with a cystic portion in the right lobe, but no confirmed preoperative diagnosis could be made. At laparotomy, liver tumors were found in the medial segment of the left lobe as well as in the right lobe, and thus an extended right lobectomy was performed. All the resected tumors were histologically diagnosed as metastatic malignant meningiomas of the liver. Despite subsequent transarterial chemoembolization for a recurrence in the residual liver, the patient died 11 months after surgery. To the best of our knowledge, only one other case of a hepatectomy for liver metastases from an intracranial malignant meningioma has been reported in the literature, but there has never been any report of surgical treatment for a metastatic meningeal tumor in the liver associated with hypoglycemia. Although our surgical treatment provided effective palliation, the prognostic significance of a surgical strategy for such patients has yet to be established.

Aged↗
PubMed1998

Successful treatment of pustulosis palmaris et plantaris with granulocyte colony stimulating factor in a patient with hereditary neutropenia.

A 26-year-old female with hereditary neutropenia had Pustulosis Palmaris et Plantaris. Drug administration did not improve her symptoms. Following administration of granulocyte colony stimulating factor (G-CSF; filgrastim), her neutrophil count increased from 300 to 58,000/microliters, and her dermatosis improved. Pustulosis Palmaris et Plantaris has been described as a representative second lesion of focal infection. Neutropenia may be one cause of Pustulosis Palmaris et Plantaris due to refractory focal infection. In the present case, increase in neutrophils with G-CSF may have improved focal infection, resulting in improvement in refractory Pustulosis Palmaris et Plantaris.

Adult↗
PubMed1998

Influence of epigenetic changes during oocyte growth on nuclear reprogramming after nuclear transfer.

Genomic imprinting is the epigenetic mechanism that distinguishes whether the loci that are inherited from the maternal or paternal genome lead to parent-specific gene expression. The mechanism also regulates development in mammalian embryos. Genomic imprinting is established after implantation according to the specific markers that are imposed on the genome during gametogenesis; the allele-specific gene expression is then maintained throughout embryogenesis. The genomic imprinting markers are erased and renewed on an own-sex basis only in cells that differentiate into germline cells. This report shows that the epigenetic modifications that occur during oogenesis perform the crucial function of establishing the allele-specific expression of imprinted genes, and also suggests that the epigenetic DNA modification is related to the reprogramming and aberrant development seen in manipulated embryos.

Animals↗
PubMed1998

Co-stimulation of T cells with CD2 augments TCR-CD3-mediated activation of protein tyrosine kinase p72syk, resulting in increased tyrosine phosphorylation of adapter proteins, Shc and Cbl.

Complete T cell activation requires not only the first signal via TCR-CD3 engagement, but also a co-stimulatory signal through accessory receptors such as CD2, LFA-1 and CD28. However, the pathway of co-stimulatory signaling through accessory receptors is incompletely understood. We report here that CD2 provides a co-stimulus for activation of CD3-mediated syk/ZAP-70 family kinase, p72Syk (Syk), in Jurkat T cells. Although cross-linking of CD2 alone or any combination of CD2 with LFA-1alpha, LFA-1beta or CD28 did not induce tyrosine phosphorylation of Syk, co-cross-linking of CD2 with CD3 enhanced CD3-mediated tyrosine phosphorylation of Syk. Enhancement of tyrosine phosphorylation of Syk by CD2 co-stimulation was CD2 antibody concentration-dependent, and time course studies showed that CD2 co-stimulation enhanced Syk tyrosine phosphorylation by 30 s and through 5 min stimulation compared with the control. In vitro kinase assay revealed that co-cross-linking of CD2 with CD3 augmented Syk kinase activity using myelin basic protein as a substrate. Furthermore, CD2 co-stimulation with CD3 resulted in enhanced tyrosine phosphorylation of adapter proteins, such as Shc and Cbl, in an antibody concentration-dependent manner. Finally, CD2 provided a co-stimulatory signals for synthesis of IL-2 in Jurkat cells and phytohemagglutinin (PHA)-activated T cells and for proliferation of PHA-activated T cells. Taken together, these results indicate that CD2 is an important co-stimulatory receptor for CD3-mediated T cell activation and functions in concert with CD3.

Adaptor Proteins, Signal Transducing↗
PubMed1998

Purification of pierisin, an inducer of apoptosis in human gastric carcinoma cells, from cabbage butterfly, Pieris rapae.

A substance strongly cytotoxic to human carcinoma cell line TMK-1 has been found in pupae, larvae and adults of the cabbage butterfly, Pieris rapae, and named pierisin. Pierisin was purified from the pupae of P. rapae by ammonium sulfate precipitation followed by DEAE-cellulose, Phenyl-Sepharose and hydroxyapatite column chromatographies. The molecular weight of the purified pierisin, which was homogenous on SDS-polyacrylamide gel, was analyzed by mass spectrometry and found to be 98 kDa. Pierisin showed a strong cytotoxic effect, with and IC50 of 0.75 ng/ml for human gastric carcinoma TMK-1 cells. The dying cells exhibited characteristic morphological features of apoptosis, such as cell shrinkage, chromatin condensation and nuclear fragmentation. Oligonucleosomal DNA fragmentation was also observed in DNA isolated from pierisin-treated cells. Moreover, similar characteristic changes showing apoptotic cell death were observed in TMK-1 cells treated with a crude extract of pupae of P. rapae. These results indicate that pierisin from the pupae of P. rapae induces apoptosis in human carcinoma cells.

ADP Ribose Transferases↗
PubMed1998

Exfoliative cheilitis: a case report and review of the literature.

We examined a 16-year-old male with persistent crusting of the lips. Biopsy showed parakeratosis, which is a normal feature, and a mild inflammatory infiltrate without fungal infection. These findings are compatible with a diagnosis of exfoliative cheilitis. Medication with anti-depressants was helpful. To date, the condition has been reported under various names: factitious cheilitis, localized crusting as an artifact, factitious lip crusting, and exfoliative cheilitis, because some cases are thought to be factitious. We suggest to call this condition 'factitious type' or 'idiopathic type' of exfoliative cheilitis, respectively, independent of the presence of a psychiatric problem.

Adolescent↗
PubMed1998

Disruption of primary imprinting during oocyte growth leads to the modified expression of imprinted genes during embryogenesis.

Parthenogenetic embryos, which contained one genome from a neonate-derived non-growing oocyte and the other from a fully grown oocyte, developed to day 13.5 of gestation in mice, 3 days longer than previously recorded for parthenogenetic development. To investigate the hypothesis that disruption of primary imprinting during oocyte growth leads to the modified expression of imprinted genes and this parthenogenetic phenotype, we have examined Peg1/Mest, Igf2, Peg3, Snrpn, H19, Igf2r and excess p57KIP2. We show that paternally expressed genes, Peg1/Mest, Peg3 and Snrpn, are expressed in the parthenotes, presumably due to a lack of maternal epigenetic modifications during oocyte growth. In contrast, the expression of Igf2, which is repressed in a competitive manner by transcription of the H19 gene, was very low. Furthermore, we show that the maternally expressed Igf2r and p57KIP2 genes were repressed in the alleles of the non-growing oocyte indicating maternal modifications during oocyte growth are necessary for its expression. Thus, our results show that primary imprinting during oocyte growth exhibits a crucial effect on both the expression and repression of maternal alleles during embryogenesis.

Animals↗
PubMed1998

Effect of magnetite on the hematocrit value in exsanguinated rats.

Magnetite prepared by an enzyme-dependent reaction gradually released iron ion into the acidic-to-neutral buffer solution. A preparatory experiment was performed to examine the efficiency of magnetite as an iron supplement. Feeding exsanguinated rats with being magnetite resulted in the hematocrit value being recovered without any serious adverse effect on the digestive organs.

Animals↗
PubMed1998

[Immunohistochemical study of retinal Müller cell response in experimental epiretinal membrane formation].

Experimental epiretinal membranes (ERM) composed of Müller cells were formed by injecting autologous whole blood into the vitreous cavity of rabbits. Müller cell responses at the early stages of epiretinal membrane formation were studied using immunostaining of proliferative cell nuclear antigen (PCNA) (for identification of the proliferating cells) and glial fibrillary acidic protein (GFAP) (as an appropriate marker for glial cell response), and the electron microscope in the experimental rabbit model. Three days after the injection, nuclei of Müller cells were found in the inner part of the retina and were PCNA positive. PCNA positive staining was seen from day 3 to day 7. No PCNA-positive nuclei were seen at day 14 in the retina or ERM. A GFAP-positive reaction was first seen in the inner retina at day 3. Afterwards, the retina and the ERM were GFAP-positive in the experimental period. We concluded that activation and proliferation of Müller cells began at an early stage after the blood injection. Müller cells remained active and expanded onto the retinal surface.

Animals↗
PubMed1998

Pelvic nerve grafts restore bladder function in denervated rats.

BACKGROUND: Autonomic nerve preservation techniques for use during surgery for rectal cancer have improved. Nevertheless, in some patients pelvic nerves must be sacrificed to excise all tumor. For these patients, nerve reconstruction at the time of operation by using nerve grafting would be useful. A rat model of this type of nerve reconstruction is described. METHODS: Animals were divided into three groups. In the sham control group, a pelvic exploration was conducted without division of the pelvic nerves. In the nerve ablation group, both pelvic nerves were excised segmentally. In the graft group, both pelvic nerves were excised and genitofemoral nerves were interposed bilaterally. At 2-week intervals postoperatively, animals from each group underwent cystometry under urethane anesthesia and neuronal tracing using fragment C of tetanus toxin for demonstration of axonal transport via regenerated nerves. RESULTS: At 6 weeks postoperatively, 60% of the grafted animals produced rhythmic contractions of the bladder. In neuronal tracing studies at weeks 4 and 6, respectively, 40% and 100% of the nerve-grafted rats had labeled neurons in the sacral parasympathetic nucleus. CONCLUSIONS: These findings suggest that pelvic nerve grafting in rats can successfully restore bladder function after surgical injury. Clinical use of pelvic nerve grafting may be indicated for patients whose pelvic nerves must be sacrificed to excise all tumor.

Animals↗
PubMed1997

Inhibition of DNA synthesis and tube morphogenesis of cultured vascular endothelial cells by chondromodulin-I.

Cartilage is an avascular tissue, and exhibits anti-angiogenic properties. Cartilage extracts have been shown to contain an inhibitor for DNA synthesis in vascular endothelial cells in vitro. Here we purified the inhibitory activity in the 10-50 kDa fraction of guanidine extracts from fetal bovine epiphyseal cartilage, and found that the inhibitor was identical with chondromodulin-I (ChM-I). Purified ChM-I inhibited tube morphogenesis of cultured vascular endothelial cells, as well as DNA synthesis. These results indicate that cartilage-specific glycoprotein ChM-I may participate in the maintenance of avascularity and anti-angiogenic properties of cartilage.

Animals↗