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Biomedical subjects

M Kaneko

Publications and source records attributed to M Kaneko.

At least 91 records · Page 5Linked to original sources
PubMed2000

Biologically active oligodeoxyribonucleotides. Part 12: N2-methylation of 2'-deoxyguanosines enhances stability of parallel G-quadruplex and anti-HIV-1 activity.

2'-Deoxyguanosine residues of a 3',5'-end-modified hexadeoxyribonucleotide (R-95288) with anti-HIV-1 activity were substituted with N2-methyl-2'-deoxyguanosine (m2dG). These modified oligodeoxyribonucleotides (ODNs) showed a 2-fold higher activity than R-95288. Also, the CD spectra of these ODNs indicated that the m2dG modification stabilized the tertiary structure of the G-quadruplex.

Anti-HIV Agents↗
PubMed2000

Involvement of nuclear factor-kappaB (NF-kappaB) signaling in the expression of inducible nitric oxide synthase (iNOS) gene in rat C6 glioma cells.

It has been demonstrated from studies using NF-kappaB inhibitors that NF-kappaB may be involved in the iNOS induction stimulated by cytokines and/or lipopolysaccharide (LPS) in various cell types and tissues. However, the actions of the inhibitors are less selective and highly cytotoxic. We constructed stable clones of C6 cells transfected with two types of IkappaBalpha mutant genes (IkappaBalpha(SS --> AA); Ser-32/36 to Ala-32/36, IkappaBalpha(KK --> RR); Lys-21/22 to Arg-21/22). IkappaBalpha(SS --> AA) strongly inhibited (1) LPS-, IL-1beta-, and TNF-alpha-induced nuclear translocation and DNA binding of NF-kappaB to the kappaB site; and (2) iNOS induction stimulated by LPS or IL-1beta plus IFN-gamma. These results indicate that NF-kappaB plays a critical role in cytokines and/or LPS-induced iNOS induction. Surprisingly, similar to the endogenous IkappaBalpha, IkappaBalpha(KK --> RR) was degraded by various stimuli, and proteasome inhibitors blocked this event. These results suggest that another Lys residue(s), other than Lys-21/22, may be required for the ligand-induced IkappaBalpha degradation by the ubiquitin-proteasome pathway.

Animals↗
PubMed2000

Neuroanatomy of cells expressing clock genes in Drosophila: transgenic manipulation of the period and timeless genes to mark the perikarya of circadian pacemaker neurons and their projections.

Subsets of brain neurons expressing the clock genes period (per) and timeless (tim) are involved in the generation of circadian behavioral rhythms. However, current knowledge of projection patterns of these neurons is limited to those immunoreactive to an antibody against a crustacean neuropeptide. The GAL4-expression system was utilized to visualize neuronal processes from all per and tim-expressing neurons in the central nervous system. Each of two types of GAL4-driver fusion genes, per-gal4 or tim-gal4, was combined in transgenic flies with marker genes-lacZ, and sequences encoding green fluorescent protein or TAU protein-under the control of the GAL4-responsive element UAS. This allowed visualization of the cytoplasm of GAL4-expressing cells. Thus, neurites of clock neurons in the adult brain as well as those of larvae and pupae were revealed. Among the anatomical patterns revealed by per-gal4- or tim-gal4-driven marker expression were a previously unknown, dorsally located neuronal cluster, along with the projections of these cells and of other dorsal neurons characterized in earlier studies only by the location of their perikarya. The similarity of projections from PER- or TIM-containing neurons during development to those in the adult implies that these features of mature clock neurons are established by the larval stages. Neurons that have never been identified as PER- or TIM-immunoreactive were also visualized in this assay system, indicating promoter activity of the clock genes in these cells and suggesting that their products cannot accumulate to detectable levels in certain neurons.

Animals↗
PubMed2000

Increased oxidative stress with gene alteration in urinary bladder urothelium after the Chernobyl accident.

We have previously shown that bladder urothelium of people living in the cesium-137 ((137)Cs)-contaminated areas of Ukraine demonstrates accumulation of stable p53 and p53 mutational inactivation, preferentially through G:C to A:T transition mutations at CpG dinucleotides, with a codon 245 hot spot. In the present study, we analyzed immuno-histochemically the relationship between oxidative stress markers and over-expression of p53 and H-ras in urinary bladder urothelium from 42 men with benign prostatic hyperplasia. Bladder mapping biopsies were obtained from 15 patients from a highly radiocontaminated area (group I), 14 patients from the less contaminated city of Kiev (group II) and 13 patients as a control group from "clean" (without radiocontamination) areas of Ukraine (group III). Irradiation cystitis with multiple foci of severe dysplasia and carcinoma in situ were observed in 15 of 15 (100%, group I) and 9 of 14 (64%, group II) cases, with 4 small transitional-cell carcinomas incidentally detected in groups I and II. Markedly elevated levels of inducible nitric oxide synthase (iNOS), cyclooxygenase 2 (COX-2) and 8-hydroxy-2;-deoxyguanosine (8-OHdG) were noted in these bladder urothelial lesions from groups I and II, accompanied by strong over-expression of p53 and less H-ras expression. These findings support the hypothesis that iNOS, COX-2 and 8-OHdG in bladder urothelium are induced by long-term exposure to low-dose radiation with a close relationship to p53 over-expression that could predispose to bladder carcinogenesis.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed2000

Contribution of automated hematology analysis to the detection of apoptosis in peripheral blood lymphocytes.

Automated hematology analyzers (analyzers) can provide complete blood counts and white blood cell (WBC) differentials in clinical laboratories and alert users to the presence of quantitative and qualitative cell abnormalities through cautionary flags. In this study, we applied analyzers to the screening of apoptotic cells in peripheral blood and examined the triggering capacity of cautionary flags to detect apoptotic cell populations. EDTA-anticoagulated fresh peripheral blood from patients with acute infectious mononucleosis containing atypical lymphocytes comprising 12.3 +/- 4. 0% of WBC was applied to a Beckman-Coulter MAXM A/L Retic (MAXM) analyzer. The lymphocyte cluster spread upward in VOLUME/DF1 scattergrams and the threshold lines between lymphocyte and monocyte clusters shifted upward. Flags for the number and percentage of lymphocytes, variant lymphocytes, and blast cells were generally present for samples containing atypical lymphocytes. After the blood from acute infectious mononucleosis patients was incubated for 4 h at 37 degrees C, peripheral blood smears revealed the presence of morphologically apoptotic cells comprising 9.0 +/- 4.2% of WBC and a comparable reduction of lymphocytes. On the MAXM analyzer, the apoptotic lymphocyte cluster appeared under the lymphocyte cluster in VOLUME/DF1 scattergrams. However, no specific flag was present to alert users to the presence of the apoptotic lymphocyte cluster. We conclude that visual inspection of scattergrams generated by the MAXM analyzer can be useful for the detection of apoptotic lymphocytes in peripheral blood. Cytometry (Comm. Clin. Cytometry) 42:209-214, 2000. Published 2000 Wiley-Liss, Inc.

Apoptosis↗
PubMed2000

Disruption of synaptic transmission or clock-gene-product oscillations in circadian pacemaker cells of Drosophila cause abnormal behavioral rhythms.

To study the function of clock-gene-expressing neurons, the tetanus-toxin light chain (TeTxLC), which blocks chemical synaptic transmission, was expressed under the control of promoters of the clock genes period (per) and timeless (tim), each fused to GAL4-encoding sequences. Although TeTxLC did not affect cycling of a clock-gene product at the gross level, it disrupted the rhythmic behavior of adult Drosophila. In constant darkness, the proportion of rhythmic flies was reduced in flies expressing active TeTxLC compared to controls, including those expressing inactive toxin. The behavior of TeTxLC-expressing flies was less synchronized to light:dark cycles than that of controls. To determine which neurons are responsible for these effects on behavior, the toxin was also expressed in restricted subsets of per/tim-expressing, laterally located pacemaker neurons by expressing TeTxLC under the control of a driver in which GAL4-encoding sequences are fused to the promoter of the pigment dispersing factor (pdf) gene. pdf-gal4-driven TeTxLC expression had relatively little effect on behavioral rhythms, implying that per/tim neurons other than pdf-expressing lateral neurons participate in the generation of rhythmic behavior. In another set of experiments, period gene products were expressed under the control of per-gal4 or tim-gal4. This resulted in an increased level of PER protein in many brain cells and reduction of bioluminescence cycling reported by a per-luciferase transgene, especially in the case of per expression affected by tim-gal4. This indicates a disruption of the transcriptional feedback loop that is a part of the oscillatory mechanism underlying Drosophila's circadian rhythms. Consistent with this molecular defect, the proportion of rhythmic individuals in constant darkness was subnormal in flies expressing PER under the control of tim-gal4, and their behavior in light:dark cycles was abnormal.

Animals↗
PubMed2000

Calcium associated resistance to H(2)O(2) in Chinese hamster V79 cells.

To investigate whether the difference in cellular sensitivity of Chinese hamster V79 and their H(2)O(2)-resistant variant cells (Hpr-4) to H(2)O(2) relates to the difference in intracellular Ca(2+) concentration in these cells, we measured Ca(2+) concentration by calcium ion analysis after loading these cells with Fura-2/AM. Intracellular Ca(2+) concentration increased in both Chinese hamster V79 and Hpr-4 cells as extracellular Ca(2+) concentration increased. However, the increase in intracellular Ca(2+) concentration in response to extracellular H(2)O(2) was more pronounced in Hpr-4 than V79 cells. H(2)O(2) cytotoxicity of Hpr-4 but not V79 cells was also decreased in response to the increase in extracellular Ca(2+) concentration. In parallel with the decrease in cytotoxicity in response to increasing extracellular Ca(2+) concentration, the frequency of mitochondrial DNA single strand breaks (SSB) in Hpr-4 cells also decreased without producing observable nuclear DNA SSB. Use of permeabilized V79 and Hpr-4 cells exposed to H(2)O(2) showed that mitochondrial DNA SSB decreased when extramitochondrial Ca(2+) concentration increased. These findings indicate that elevated intracellular Ca(2+) concentration may protect against H(2)O(2)-induced mitochondrial damage and cytotoxicity in these cells.

Animals↗
PubMed2000

SYT-SSX fusion proteins in synovial sarcomas: detection and characterization with new antibodies.

To identify and characterize the SYT-SSX fusion proteins in synovial sarcomas, we developed two polyclonal antibodies against the N-terminal part and for the C-terminal part of the SYT-SSX2 protein. Specificity was demonstrated on COS-7 cells transfected with two subtypes of SYT-SSX fusion genes, SYT-SSX1 and SYT-SSX2. Both antibodies recognized a single protein of 61 kDa in an immunoprecipitation of the transfected COS-7 cell lysates. These antibodies also detected the native protein of 61 kDa in the lysate of a human synovial sarcoma cell line (HS-SY41) with immunoprecipitation, and in extracts of human synovial sarcomas with western blot analysis. An immunohistochemical study, using human synovial sarcoma tissues, demonstrated that the SYT-SSX fusion proteins localized in the nucleus of the tumor cells. These antibodies provide a useful method for studying the expression of the SYT-SSX fusion proteins.

Antibodies, Neoplasm↗
PubMed2000

Significance of alpha 9 beta 1 and alpha v beta 6 integrin expression in breast carcinoma.

BACKGROUND: Both alpha 9 beta 1 and alpha v beta 6 integrins have been newly identified from the tracheal epithelium of guinea pig. It has been pointed out that alpha 9 beta 1 functions as a receptor for tenascin-C and osteopontin. As for the ligands of alpha v beta 6, fibronectin and tenascin-C have been identified. It has not been ascertained whether alpha 9 beta 1 and alpha v beta 6 are expressed in normal breast tissue, benign breast lesion or breast carcinoma. METHODS: Immunohistochemical staining for alpha 9 beta 1 and alpha v beta 6 was performed in benign breast lesion and breast carcinoma specimens. Western blotting was carried out on 11 breast carcinoma cases. RESULTS: alpha 9 beta 1 was expressed in the cytoplasm of carcinoma cells in 23 of 90 cases (26%) and alpha v beta 6 in the membrane of carcinoma cells in 16 of 90 cases (18%). However, these findings of alpha 9 beta 1 and alpha v beta 6 did not correlate with any clinicopathological factors including the patients' age, tumor size, histological type of carcinoma, location of carcinoma cells and hormone receptor status. With regard to the histological grade of carcinoma, alpha v beta 6 and alpha 9 beta 1 expression did not statistically correlate, although no expression of alpha v beta 6 was observed in 14 cases of Grade I. On Western-blott analysis strong and weak bands consistent with alpha v beta 6 were noted in the membrane fraction extracted from breast carcinoma cells. On the other hand weak bands consistent with alpha 9 subunit were noted in the whole cell lysates of breast carcinoma cells and very weak or no bands consistent with alpha 9 subunit were noted in the membrane fraction extracted from the breast carcinoma cells. CONCLUSIONS: Significance of alpha 9 beta 1 and alpha v beta 6 integrins expression in breast carcinoma was still unknown on clinicopathological examination. The findings of Western blot analysis may indicate that the transportation system of glycoproteins such as integrins to the cell membrane of carcinoma cells is disturbed, although these integrins can be produced.

Adenoma↗
PubMed2000

Cytokines facilitate chemotactic motility of breast carcinoma cells.

BACKGROUND: Both growth and motility of various tumor cells have been shown to be influenced by surrounding cells such as lymphocytes, histiocytes and fibroblasts through various cytokines, growth factors and extracellular matrices. The role of cytokines and extracellular matrices produced by lymphocytes, histiocytes and fibroblasts on migration and invasion of breast carcinoma cells has not been fully investigated METHODS: We investigated the effect of hepatocyte growth factor (HGF), interleukin (IL)-6, IL-8, IL-11, soluble type IV collagen and soluble laminin on the migration of 3 human breast carcinoma cell lines, MDA-MB-231, MCF-7 and T-47D, using a cell culture insert and a biocoat matrigel invasion chamber to assess migration across a matrigel-coated polyethylene telephtalate membrane. RESULTS: HGF, IL-6, IL-11 and IL-8 induced significant migration of MDA-MB-231 cells depending on the dose of each cytokine. However, type IV collagen and laminin inhibited migration of MDA-MB-231 cells. In contrast, IL-8 inhibited migration of MCF-7 cells and IL-6 induced significant migration of T-47D cells, while no other cytokine or extracellular matrix induced significant migration of MCF-7 and T-47D cells. Only HGF induced significant invasion of MDA-MB-231 cells depending on the dose. MCF-7 and T-47D cells did not invade in response to any of the cytokines and extracellular matrices tested. CONCLUSIONS: These results suggest the possibility that the potency of chemotaxis or chemoinvasion differs according to the breast carcinoma cell line and that various cytokines and extracellular matrices secreted by lymphocytes, histiocytes and fibroblasts in the stroma of breast carcinoma can affect the invasion of breast carcinoma cells.

Biocompatible Materials↗
PubMed2000

Immunohistochemical detection of cathepsin D, K, and L in the process of endochondral ossification in the human.

Cathepsins D, K, and L were immunolocalized in tissue undergoing endochondral ossification in the human. Cathepsins D, K, and L were localized in osteoclasts and chondroclasts attached to bone matrix and cartilage matrix, respectively. Cathepsins D and L were immunostained in chondrocytes. Immunolocalization of cathepsin D was limited to hypertrophic chondrocytes adjacent to the osteochondral junction. In contrast, cathepsin L was immunolocalized in both proliferating and hypertrophic chondrocytes. In the bone marrow space, cathepsins D, K, and L were localized in multinucleated cells. Cathepsin D was diffusely detected in mononuclear bone marrow cells which were negative for cathepsins K and L. The present findings indicated that cathepsins K, D, and L were associated with the process of endochondral ossification in the human, and suggested that these cathepsins share roles in bone and cartilage turnover in the human.

Bone Marrow↗
PubMed2000

Standard radial bone mineral density and physical factors in ordinary Japanese women.

To prevent osteoporosis, which is expected to increase in incidence in this rapidly aging society, in recent years bone mineral density (BMD) has frequently been measured as a predisposition index. However, these measurements are made on different sites with different apparatus, and the results are independently studied by different institutions. In our present investigation, to establish the standard radius BMD as determined by dual-energy X-ray absorptiometry (DXA), we carried out a general population survey in 29 municipalities and prefectures on 11,252 locally residing females aged 15 to 83 years (mean, 35.61 +/- 12.85 years). Their YAM (young adult mean) BMD was estimated at 0.664 +/- 0.054 g/cm2, which was almost the same as the figure given in the 1996 version of the diagnostic criteria for primary osteoporosis. We further studied the relationships of BMD to age and physical factors known to be influential to BMD. It was found that BMD was correlated negatively to age and positively to body mass index (BMI). The average values we obtained for age and physique groups appeared to have provided reliable indices for the primary prevention of osteoporosis.

Adolescent↗
PubMed2000

Uterine myxoid leiomyosarcoma.

BACKGROUND: Uterine myxoid leiomyosarcoma is rare, has a poor prognosis, and must be distinguished from a uterine myoma with myxomatous change. CASE: A 56-year-old woman with a history of epigastric pain and generalized abdominal swelling had a peritoneal cavity filled with tumor that originated from the posterior uterine wall. Chemotherapy and two operations for recurrence could not prevent fatal metastases to the vascular system. Histopathology showed a typical myxoid leiomyosarcoma. CONCLUSION: Although the patient's prognosis was poor, no mitoses were observed, and the nuclear abnormalities were not sufficient to diagnose the tumor as malignant at the initial surgery. Whenever a uterine myoma with myxomatous change is found, the patient should be monitored carefully.

Fatal Outcome↗
PubMed2000

Effect of an antioxidant, ebselen, on development of chronic cerebral vasospasm after subarachnoid hemorrhage in primates.

BACKGROUND: Oxidation and/or free radical reactions after subarachnoid hemorrhage (SAH) may be involved in the development of chronic cerebral vasospasm. The inhibition of these reactions is thought to be one of the therapeutic strategies for prevention of cerebral vasospasm. We investigated the effect of Ebselen, a synthetic seleno-organic compound, which exhibits anti-oxidation by glutathione peroxidaselike activity to inhibit free radical reactions by lipid peroxidation on the development of chronic cerebral vasospasm in a primate model. METHODS: Seventeen monkeys were used. SAH was produced by introduction of a blood clot around the right middle cerebral artery and the right side of the circle of Willis in all animals. The monkeys were randomly divided into three groups according to Ebselen dosage: 1) no dosage or non-treated group; 2) high-dose Ebselen group; and 3) low-dose Ebselen group. The drug was administered at 10 mg/Kg in the high-dose group and 5 mg/Kg in the low-dose group twice a day in each group for 7 days after SAH. The vessel diameter was evaluated on angiograms before the induction of SAH and at Day 7 following SAH. RESULTS: In the untreated group, the angiograms showed significant (p < 0.05) reductions of the mean vessel caliber of the right internal carotid (ICA) (38 +/- 10% reduction) and the middle cerebral artery (MCA) (56 +/- 9.7%) compared with the baseline value before SAH. In the high-dose Ebselen-treated group, the mean percent reduction in vessel caliber of the right ICA (16 +/- 11%) and MCA (28 +/- 9.5%) on Day 7 angiograms were significantly (p < 0.05) lower than those in the nontreated group, whereas the mean percent reduction of these vessels in the low-dose Ebselen-treated group showed no significant difference compared with the untreated group. CONCLUSIONS: Chronic cerebral vasospasm was inhibited in the animals in which a relatively large amount of Ebselen was administered for 7 days after SAH. The results suggest that the oxidation or free radical reaction by lipid peroxidation after SAH might be involved in the pathogenesis of vasospasm, and that inhibition of these reactions by drugs, such as Ebselen, may have a promising effect for prevention of vasospasm.

Animals↗
PubMed2000

Ipsilateral irradiation for carcinomas of tonsillar region and soft palate based on computed tomographic simulation.

PURPOSE: To reduce xerostomia in selected patients with carcinomas of the tonsillar region and soft palate. METHODS AND MATERIALS: We evaluated the treatment results of 32 patients with tonsillar region and soft palate carcinoma treated by radical radiotherapy between May 1989 and December 1996. They have a unilateral tumor that did not cross midline and have no contralateral neck lymphnode metastasis and treated with an ipsilateral technique (an anterior oblique and a posterior oblique field). All patients were planned with computed tomographic (CT) simulation and given 65 Gy in 26 fractions in 6.5 weeks with or without 5-15 Gy boost irradiation. The median follow-up was 44 months (4-86 months). RESULTS: Five-year overall, cause-specific survival, local control, and regional control rate was 64, 79, 74 and 81%. No failure at the contralateral neck occurred. Moderate or severe symptomatic xerostomia was seen in 3 (9%) patients and ostero-radionecrosis requiring surgery occurred in one (3.3%) of 32 patients. CONCLUSION: It is suggested that the ipsilateral technique is indicated in patients who had an unilateral tonsillar region or soft palate carcinoma that did not cross midline and have no contralateral neck lymphnode metastasis.

Adult↗