Biomedical subjects

H Kikuchi

Publications and source records attributed to H Kikuchi.

At least 289 records · Page 16Linked to original sources

PubMed1996

Altered nitric oxide synthase immunoreactivity in the brain of stroke-prone spontaneously hypertensive rats.

To obtain information about the role of nitric oxide (NO) in the development of hypertensive cerebral lesions, we used immunohistochemical methods to study the distribution and level of nitric oxide synthase (NOS) in the brain of stroke-prone spontaneously hypertensive rats (SHRSPs). The early changes in the brain of SHRSPs were petechiae, edema and massive glial accumulation around fibrin deposits, which contained necrotized microvessels, whereas advanced cerebral lesions comprised massive bleeding, cavity formation and diffuse degeneration of the white matter. In the normotensive control rats, immunoreactivity for NOS was demonstrated in scattered neuronal cells, as has been reported previously, but there was no reactivity in glial cells. In the present study in SHRSPs, however, considerable NOS immunoreactivity was observed in most reactive astrocytes and in a proportion of the microglial cells and macrophages in the vicinity of the cortical lesions and in the subcortical white matter both ipsi- and contralateral to the cortical lesion. The nerve cells in the edematous region also showed weak immunoreactivity for NOS. The distribution of increased NOS in SHRSP brains corresponded well with the sites of extravasated plasma fluid as demonstrated by anti-fibrinogen antibody. Based on these findings, we postulate that edema and the simultaneously generated free radicals or some extravasated plasma components may induce expression of NOS in the reactive cells and nerve cells, and that the NO thus generated may be involved in the development of hypertensive cerebral lesions.

Animals↗

PubMed1996

Cross-linking of B cell antigen receptor-related structure of pre-B cell lines induces tyrosine phosphorylation of p85 and p110 subunits and activation of phosphatidylinositol 3-kinase.

To understand the function of B cell antigen receptor (BCR)-related complex on pre-B cells (pre-BCR, Vpre-B/lambda 5/mu heavy chain/Ig-alpha/Ig-beta), we examined pre-BCR- and BCR-mediated signaling events in human and mouse pre-B (Nalm-6, 697, NFS-5), immature B (IgM+ Daudi, WEHI-231) and mature B (IgM+ IgD+ BALL1) cell lines. Anti-mu cross-linking induced tyrosine phosphorylation of the cytoplasmic proteins in each cell type, but did not induce a detectable Ca2+ mobilization response in pre-B cells. While the pre-B cells expressed Syk protein at levels similar to those found in B cell lines, pre-BCR cross-linkage did not induce phosphorylation of Syk tyrosine residues. Different protein kinase C isozymes were expressed by pre-B (PKC-alpha), immature B (PKC-alpha and -beta) and mature B (PKC-beta) cell lines. Anti-mu cross-linking induced PKC translocation from the cytosolic to the membrane compartment in immature and mature B cells, but did not have this effect in a pre-B cell line. Anti-mu cross-linking induced tyrosine phosphorylation of the p85 and p110 subunits of phosphatidylinositol 3-kinase (P13-kinase) in both pre-B and B cell lines, but the pre-BCR induced P13-kinase activation was Syk independent. Ligation of the pre-BCR complex thus triggers a characteristic signaling pattern in pre-B cells.

Animals↗

PubMed1996

The department of neurosurgery, Kyoto University School of Medicine.

Kyoto University, founded in 1897, is the second oldest national university in Japan. Kyoto University Hospital opened in 1899, and neurosurgical activities began soon thereafter, mainly within the Department of Surgery. The Department of Neurosurgery was established in 1964 and has since steadily extended its clinical territory. The department has provided neurosurgeons and residents for 80 neurosurgical services at 12 related universities/colleges and 68 satellite hospitals. Approximately 400 operations per year are performed, and more than 30 research projects are ongoing in collaboration with other departments and scientific institutions. The main function of our department is the education and production of leading neurosurgeons who have profound knowledge in basic sciences.

Academic Medical Centers↗

PubMed1996

Absence of down-regulation and translocation of the eta isoform of protein kinase C in normal human keratinocytes.

Among 11 isoforms of protein kinase C (PKC), we previously reported that the eta isoform of PKC plays a crucial role in mediating differentiation of keratinocytes. Activation of PKC is associated with its intracellular translocation from the cytoplasm to the plasma membrane, followed by down-regulation through proteolytic cleavage of the PKC molecules. In the present study, we demonstrated that the eta isoform of PKC is unique in that it is not translocated nor down-regulated upon stimulation. The level of the eta isoform, assayed by immunoblotting, remained unchanged during the first 12 h and then increased slightly up to 24 h when treated with tumor promoters or activators of PKC in constitutively expressing normal human keratinocytes. The activity of the eta isoform also remained unchanged after the 12-O-tetradecanoyl-phorbol-13-acetate treatment, as judged by binding ATP analog, autophosphorylation, and phosphorylation of an exogenous substrate. The alpha isoform of PKC, however, was rapidly down-regulated and was undetectable by 6 h after the treatment. These observations were further confirmed by immunohistochemical staining of normal human keratinocytes and transiently expressing COS1 cells. In addition, although the alpha isoform rapidly translocated to the plasma membrane, the eta isoform remained in the cytoplasm.

Amino Acid Sequence↗

PubMed1996

Effect of two levels of transgalactosylated oligosaccharide intake in rats associated with human faecal microflora on bacterial glycolytic activity, end-products of fermentation and bacterial steroid transformation.

The effects of two levels of transgalactosylated oligosaccharide (TOS) intake on bacterial glycolytic activity, end products of fermentation and bacterial steroid transformation were studied in rats associated with a human faecal flora. Rats were fed a human-type diet containing 0, 5 or 10% TOS. Caecal pH decrease correlated with the amount of TOS in the diet. Intake of the TOS diet induced a decrease in blood cholesterol and a strong increase in beta-galactosidase activity in the hindgut. TOS fermentation led to production of hydrogen and short chain fatty acids, whereas ammonia and branched-chain fatty acids were decreased. A diet containing 10% TOS increased caecal lactic acid concentrations and reduced beta-glucuronidase activities and steroid transformation.

Animals↗

PubMed1996

A case of malignant transformation in thoracic vertebral hemangioma following repetitive irradiation and extraction.

We report a rare case of thoracic vertebral hemangioma which developed into angiosarcoma during the course of repetitive operations and irradiation. A 44 year old female was operated on for hemangioma of the first thoracic vertebra. The diagnosis of hemangioma was confirmed histopathologically with the specimen from the first operation. The tumor developed multiple lesions later in the clinical course after the first operation, these lesions were removed in four consecutive operations and each histological diagnosis was that of hemangioma. Throughout the period of these operations, the patient was treated with steroid, and with radiotherapy simultaneously. The patient underwent the fifth operation for the recurrence of the tumor on 26 March 1990, and the histopathological diagnosis was not hemangioma but hemangiosarcoma which was considered a malignant transformation. The tumor cells immunohistochemically revealed positive staining with UEA-I, Factor-VIII, as the tumor immunohistochemically showed a vascular endothelioid nature.

Adult↗

PubMed1996

Clinico-epidemiological features of infantile hydrocephalus in Japan.

In 1988, a nationwide survey was conducted in Japan, in order to examine the prevalence and clinico-epidemiological features of hydrocephalus that developed before 1 year of age. The study was based on questionnaires that were sent to all hospitals in Japan with more than 200 beds. There were 1435 patients who were eligible for the analysis. They were born before 1987 and diagnosed as having infantile hydrocephalus. Approximately two-thirds of the patients had primary hydrocephalus. Neural tube defects were the most frequent cause of the primary hydrocephalus and common among full-term infants. On the other hand, secondary hydrocephalus occurred more often in preterm infants, mainly following intracranial hemorrhage. Intracranial hemorrhage as a cause of hydrocephalus increased over the year, while the incidence of hydrocephalus secondary to intracranial infection decreased during the same period.

Brain↗

PubMed1996

[Detection of DNA specific for Aspergillus species in serum samples from two patients with invasive pulmonary aspergillosis].

We investigated the possible presence of DNA specific for Aspergillus species in serum samples of two patients who were strongly suspected for invasive pulmonary aspergillosis (IPA) by a nested polymerase chain reaction (PCR) method. Both patients were diagnosed as having acute myelogenous leukemia and treated with induction chemotherapy. During chemotherapy-induced granulocytopenia, they complained of high fever, and the chest X-rays indicated infiltration shadows in their lungs. They were treated with antibiotics intravenously, but no clinical improvement was observed. As the results of the nested PCR were positive at the acute stage of infection, amphotericin B i.v. and granulocyte colony stimulating factor s.c. administrations were started in both cases. In case 1, the infectious disease improved and the nested PCR results turned negative after treatment. In case 2, in spite of the progression of the disease, the nested PCR results turned negative during treatment. Although we consider this method very useful for the diagnosis of IPA, further prospective evaluation with a large clinical population sample is required.

Aged↗

PubMed1996

[Prevention of infections in a case with myelodysplastic syndrome by an intermittent subcutaneous administration of G-CSF].

An 83-year-old male was admitted to our hospital because of pancytopenia and low grade fever on April 19, 1993. On admission, hematological data were as follows: WBC 1,000/microliters with 19% neutrophils, RBC 367 x 10(4)/microliters, Hb 9.5 g/dl and platelets 6.7 x 10(4)/microliters. Bone marrow examination revealed 6.6% myeloblasts and 33.5% erythroblasts. Morphological abnormalities included hypersegmentation, degranulation and pseudo-Pelger's nuclear anomaly in neutrophils. Based on these findings the diagnosis of refractory anemia with excess of blasts (RAEB) of the myelodysplastic syndrome (MDS) was made and therapy with low dose Cytarabine (Ara-C) was initiated in April 1993. The patient had two episodes of severe pneumonia in June and July. Therefore, 75 micrograms/day of G-CSF was given in addition to antibiotic therapy for the second episode of infection in July. Thereafter the severe infection subsided, and G-CSF administration was switched to an intermittent schedule (75 micrograms twice a week) since September. Cytarabine ocfosfate (100 mg/day) was added for 10-14 days at interval 1-2 months from October,1993. He has been well with no episode of infection for more than two year. One major concern regarding the clinical application of G-CSF in MDS patients is related to the possible stimulation of leukemic cell proliferation. Frequent hematological monitoring is necessary in patients with RAEB who are prone to develop acute myeloid leukemia. However, we administered G-CSF at a relatively low dose twice a week for over two year and could successfully prevent infections without inducing the leukemic changes.

Aged↗

PubMed1996

Positive regulation by nitrite of the nitrate assimilation operon in the cyanobacteria Synechococcus sp. strain PCC 7942 and Plectonema boryanum.

In the absence of fixation of ammonium to glutamine, nitrate and nitrite activated transcription of the nitrate assimilation (nirA-nrtABCD-narB) operon of Synechococcus sp. strain PCC 7942. In a nitrate reductase-deficient mutant, only nitrite activated transcription, indicating that nitrite is the actual activator of the operon. Nitrate and nitrite were also found to activate the transcription of a nitrate assimilation operon in the filamentous nonheterocystous nitrogen-fixing cyanobacterium Plectonema boryanum.

Anion Transport Proteins↗

PubMed1996

Decreased serum antioxidant activity of hemodialysis patients demonstrated by methylguanidine synthesis and microsomal lipid peroxidation.

This study aims to raise the possibility of methylguanidine, a peroxidative product of creatinine, as a measure of the peroxidative state. As a known standard, we measured the inhibitory effect of uremic serum on the NADPH-dependent microsomal lipid peroxidation. This is an established method for evaluating the peroxidative state and is compared to the effect of uremic serum on methylguanidine synthesis. The study shows decreased serum antioxidant activity in hemodialysis patients by both methods, though there is no correlation between them. These results support the use of methylguanidine as a peroxidative marker and suggest a difference in the reactive oxygen species involved in the reactions of methylguanidine synthesis and microsomal lipid peroxidation.

Adult↗

PubMed1996

Enhancing the effect of anticancer drugs against the colorectal cancer cell line with electroporation.

Electroporation was applied in vitro and in vivo in the treatment of human colorectal cancer cell lines to study whether it can enhance the effect of bleomycin (BLM), 5-fluorouracil (5-FU) and cis-platinum (CDDP). We used LS174T and Colo320 cells derived from human colon cancer as target cells in this study. When the LS174T cells were used as target cells, the IC50 of BLM decreased to 10(-3) times, while that of 5-FU decreased to only about one fifth with the application of electric current. In the case of the Colo320 cells, the IC50 of BLM and 5-FU were about one hundredth and a half, respectively. The effect of CDDP was not enhanced with electric current. In vivo experiments were also performed using LS174T cells transplanted subcutaneously (s.c.) into nude mice. By treatment with intravenously (i.v.) administered BLM and simultaneous application of the electric current, tumors were markedly decreased in size after three weeks.

Animals↗

PubMed1996

Effects of a hydroxyl radical scavenger on delayed ischemic neurological deficits following aneurysmal subarachnoid hemorrhage: results of a multicenter, placebo-controlled double-blind trial.

A water-soluble, novel synthetic compound, AVS ((+/-)-N, N'-propylenedinicotinamide; nicaraven) has no demonstrable vasoactive properties but scavenges hydroxyl radicals in aqueous environmental conditions at neutral pH. Based on the results of preceding experimental and clinical studies showing marked ameliorative effects of AVS on cerebral vasospasm and ischemic brain damage, a multicenter, placebo-controlled double-blind clinical trial was undertaken to verify its beneficial effects on delayed ischemic neurological deficits (DINDs) due to vasospasm and on the overall outcome of patients with subarachnoid hemorrhage (SAH). A total of 162 patients with SAH who had Glasgow Coma Scale scores between 7 and 15 on admission were enrolled in the trial. Drug administration (4 g AVS or 4 g glucose as placebo; infused intravenously for 6-8 hours once a day) was begun within 5 days post-SAH and continued for 10 to 14 days. Intent-to-treat analysis of these patients revealed that the overall incidence of DINDs, which was defined as an exacerbation of impaired consciousness and/or focal neurological deficits, was significantly reduced, by 34.5% (placebo 54.2%, AVS 35.5%; p < 0.05, Mann-Whitney U-test). The Glasgow Outcome Scale (GOS) score at 1 month was significantly improved by AVS (p < 0.05, U-test). At 3 months, the difference in the GOS scores between the groups became marginal on U-tests (p < 0.10), but the percentage of good outcome tended to increase, with a relative increase of 20.3% (AVS 76.3%, placebo 63.4%; p < 0.10, chi-square test), and the cumulative incidence of death was significantly reduced (p < 0.05, log-rank test). No significant adverse reaction attributable to treatment was observed. the usefulness of AVS in therapy for SAH is strongly indicated by the fact that the agent significantly ameliorated DINDs, leading to a marked improvement in the GOS scores at 1 month, as well as a reduction in the cumulative incidence of death by 3 months.

Adult↗

PubMed1996

Apoptosis of human glioma cells in vitro and in vivo induced by a neutralizing antibody against human basic fibroblast growth factor.

Basic fibroblast growth factor (bFGF) is mitogenic to neuroectoderm- and mesoderm-derived cells and is a potent angiogenic factor. Abundant amounts of this factor and its receptor are detected in human glioma tissues and cells, and bFGF in glioma is thought to be involved in autonomous cell growth as an autocrine growth factor. A neutralizing mouse monoclonal antibody (MAb) against bFGF, 3H3 MAb, has been shown to inhibit both in vitro and in vivo growth of human glioma cell lines. This study shows that the human glioma cell lines U-87MG and U-251MG, which express high levels of bFGF and its receptor, can be induced to undergo apoptosis when cultured with 3H3 MAb. It is also demonstrated that 3H3 MAb can cause apoptosis in the same glioma cells that were transplanted into nude mice. Furthermore, enforced overexpression of bcl-2 protein by gene transfection prevented 3H3 MAb-induced apoptosis of glioma cells. It is concluded that induction of apoptosis by the neutralizing antibody is a promising therapeutic strategy for glioma.

Antibodies↗

PubMed1996

[A case of Paget's disease with progressive sensorineural hearing loss involved in the bilateral bony labyrinths].

Paget's disease of the bone is a chronic, progressive disease of unknown etiology characterized by abnormal bony resorption and deposition. It is a common skeletal disease in Europe and North America, while in Japan it is very rare. Paget's disease of the temporal bone has been reported to cause hearing loss frequently. We report a 50-year-old woman with Paget's disease who had progressive bilateral sensorineural hearing loss and right vestibular dysfunction. CT and 3 Dimensional CT (3D-CT) images demonstrated resorption of the entire bony labyrinth and its surroundings on both sides and that the temporal bone elsewhere remained intact. Bone scans revealed disease symmetrically in the bilateral otic capsules. Previous studies indicated that the bone changes in Paget's disease in the petrous pyramid begin in areas best supplied with marrow tissue and that the otic capsule is relatively spared until advanced changes are present in the remainder of the petrous pyramid. But, this patient mainly had foci in the bilateral otic capsules and the pattern was similar to cochlear otosclerosis. 3D-CT was useful for differentiation of Paget's disease and cochlear otosclerosis. The pattern of the affected areas indicated that this is a very rare situation even in the reports of Europe and North America, where the disease is rather common.

Diagnosis, Differential↗

PubMed1996

[BA top aneurysm].

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Basilar Artery↗

PubMed1996

[Acute lymphoblastic leukemia with marked morphologic abnormalities after chemotherapy for gastric cancer].

A 76-year-old man was admitted to our hospital in February, 1994 because of fever and general fatigue. The patient had received radical gastrectomy for gastric cancer in August, 1987 and was subsequently treated with adjuvant chemotherapy using UFT for 25 months. On admission, the leukocyte count was 57,700/microliters with 74% blasts. Bone marrow aspiration revealed proliferation of blasts with marked giant cells and polynucleolar cells. The diagnosis of T-lineage of acute lymphoblastic leukemia (ALL) was then made by analysis of surface markers and T-cell receptor rearrangement. Although combination chemotherapy was initially effective, blasts rapidly reappeared in the peripheral blood, and the patient died of pneumonia in August, 1994. In the presented case, blasts showed marked morphologic abnormalities. It is well known that most cases of therapy-related leukemia deviate from the myeloid lineage, and rarely from the lymphoid lineage. In addition, morphologic abnormalities are rare in de novo ALL. Since such abnormalities were demonstrated in our patient, and UFT was administered for a long period, it is possible that this leukemia occurred as a second malignancy related to UFT treatment.

Aged↗

PubMed1996

[Mononeuritis multiplex associated with measles virus infection].

We describe a 19-year-old patient who developed mononeuritis multiplex associated with measles virus infection. On April 30th, 1995, he suffered from fever and skin eruption, which disappeared ten days later. Thirteen days later, he noticed weakness of the fingers of both hands and forearms, and pain on both elbow joints. He was admitted to our hospital on June 12th, 1995. Neurologic examination revealed weakness and sensory disturbance, confined to the distal aspects of the right radial nerve and left median nerve. The electrodiagnostic findings confirmed those of axonal neuropathy in the right radial and left median nerves. Routine laboratory studies were normal. The cerebrospinal fluid test and EEG were normal. The IgG and IgM antibody titers against measles virus continued to be elevated in serum over four months after the onset, while they were not elevated in the cerebrospinal fluid. The corticosteroid therapy was mildly effective. Although the pathogenesis of this case is unclear, we speculate that the mononeuritis multiplex was caused by vasculitis related to the persistent measles virus infection in both elbow areas.

Adult↗