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K Nagata

Publications and source records attributed to K Nagata.

At least 55 records · Page 3Linked to original sources
PubMed2001

The presence of chemokine receptor (CCR5, CXCR3, CCR3)-positive cells and chemokine (MCP1, MIP-1alpha, MIP-1beta, IP-10)-positive cells in human periapical granulomas.

The infiltration of leukocytes into inflammation sites such as observed in human periapical granulomas is considered to be mediated by chemotactic factors. In this study, we examined the presence of chemokine- and chemokine receptor-positive cells in samples obtained from human subjects by means of immunohistochemical methods. Macrophage chemotactic protein-1 (MCP-1), macrophage inflammatory protein (MIP)-1alpha, MIP-1beta and IFN-inducible protein 10 (IP-10)-producing cells were present in periapical granulomas. In addition, chemokine receptor CCR3-, CCR5-, and CXCR3-positive cells were also present. In contrast, no factor expression was observed in clinically healthy periodontal ligament, serving as a negative control. Our findings suggest that these chemokines are responsible for modulating the process of disease, such as human apical periodontitis.

Adolescent↗
PubMed2001

Chromosome 6p21.2, 18q21.2 and human papilloma virus (HPV) DNA can predict prognosis of cervical cancer after radiotherapy.

Loss of heterozygosity (LOH) is one of the most important mechanisms for inactivation of tumor-suppressor genes. Studies of LOH in patients with cervical carcinoma have reported a high frequency of LOH on 3p21.3, 6p21.2, 17p13.1, and 18q21.2. Our study explored whether p53 status, human papilloma virus (HPV), and LOH on chromosome 3p21.3, 6p21.2, 17p13.1, and 18q21.2 are associated with treatment outcome in 65 patients with cervical cancer after radiotherapy. Tumors and normal DNA were analyzed by polymerase chain reaction (PCR) for genetic losses at 10 polymorphic microsatellite loci. The presence of HPV and its type were analyzed by PCR-based assay using the consensus primers for E6, E7, and L1 region. Mutations of the p53 gene were identified by a single-strand conformation polymorphism analysis. Chromosomes 3p21.3, 6p21.2, 17p13.1, and 18q21.2 were involved in the LOH in 23.1%, 41.5%%, 33.8%, and 23.1% of the tumors in our study, respectively. HPV-positive tumors were found in 73.8% of the patients and p53 mutation in 10.8%. The patients with LOH on chromosome 6p21.2 and 18q21.2 survived significantly shorter compared with those without LOH on chromosome 6p21.2 and 18q21.2 in both the overall survival (P = 0.006 and P = 0.007) and the disease-free survival (P = 0.005 and P = 0.008). The HPV-negative patients survived significantly shorter compared with the HPV-positive patients in both the overall survival (P = 0.01) and the disease-free survival (P = 0.04). According to multivariate analysis, HPV status (P = 0.0004, P = 0.01), LOH on 6p21.2 (P = 0.006, P = 0.02), and LOH on 18q21.2 (in both P = 0.01) is a significant predictor of both overall and disease-free survival time. The results of our study suggest that absence of HPV infection, LOH on 6p21.2, and LOH on 18q21.2 are the most important determinants of outcome of patients with cervical carcinoma after radiotherapy.

Adult↗
PubMed2001

Aggressive NK cell lymphoma/leukemia with clonal der(3)t(1;3) (q12;p25), del(6)(q13) and del(13)(q12q14).

We describe a 54-year-old man with CD2, CD7, and CD56-positive but CD3, CD4, and CD8-negative aggressive NK cell lymphoma/leukemia. Chromosome analysis of the peripheral blood cells showed clonal aberration consisting of 46,XY,dup(3)(p21p25),der(3)t(1;3)(q12;p25),del(5)(q13q22), del(6)(q13),del(13)(q12q14). The peripheral blood lymphoma cells contained clonal EBV-DNA by Southern blot analysis. The disease was refractory to chemotherapy and the clinical course was aggressive and rapid. Deletion 6q and deletion 13q have been frequently reported in NK cell lymphoma/leukemia. Thus, some tumor suppressor genes involving NK cell malignancies may be present in these regions.

Antigens, CD7↗
PubMed2001

Function of nucleophosmin/B23, a nucleolar acidic protein, as a histone chaperone.

We previously identified and purified a nucleolar phosphoprotein, nucleophosmin/B23, as a stimulatory factor for replication from the adenovirus chromatin. We show here that nucleophosmin/B23 functions as a histone chaperone protein such as nucleoplasmin, TAF-I, and NAP-I. Nucleophosmin/B23 was shown to bind to histones, preferentially to histone H3, to mediate formation of nucleosome, and to decondense sperm chromatin. These activities of B23 were dependent on its acidic regions as other histone chaperones, suggesting that B23/nucleophosmin is a member of histone chaperone proteins.

Cell Nucleolus↗
PubMed2001

Interobserver and intraobserver reliability of the japanese orthopaedic association scoring system for evaluation of cervical compression myelopathy.

STUDY DESIGN: The inter- and intraobserver reliabilities of an assessment scale for cervical compression myelopathy were examined statistically. This scoring system consists of seven categories: motor function of fingers, shoulder and elbow, and lower extremity; sensory function of upper extremity, trunk and lower extremity; and function of the bladder. It evaluates the severity of myelopathy by allocating points based on degree of dysfunction in each category. OBJECTIVES: To determine the inter- and intraobserver reliabilities of the revised scoring system (17 - 2 points) for cervical compression myelopathy proposed by the Japanese Orthopedic Association. SUMMARY OF BACKGROUND DATA: Several scales to assess clinical outcome from treatment of cervical compression myelopathy have been proposed. Most of these scales include items evaluated by observers. However, no system, including the Japanese Orthopedic Association scoring system, has yet been validated in terms of interobserver reliability. METHODS: From five different university hospitals, 10 spine surgery specialists, 10 orthopedic surgeons who had just passed the board examination of the Japanese Orthopedic Association, and 13 residents in the first or second year of orthopedic residency programs were chosen. The participants in this study were 29 patients with myelopathy secondary to ossification of the posterior longitudinal ligament selected from five participating university hospitals. Several surgeons interviewed each patient twice at intervals of 1 to 6 weeks. Inter- and intraobserver reliabilities of the total score for all categories were evaluated by the intraclass correlation coefficient. The extension of the kappa coefficient of Kraemer also was calculated for each category to assess reliability of multivariate categorical data. RESULTS: The interobserver reliability of the total score for the first interview (intraclass correlation coefficient = 0.813) and the intra- and interobserver reliabilities of the total score (intraclass correlation coefficient = 0.826) were high. The level of experience and the hospital slightly affected the reliability of the Japanese Orthopedic Association scoring system. The kappa values for intraobserver data generally were high in each category, whereas the kappa values for interobserver data were relatively low for the categories of shoulder-elbow motor function and lower extremity sensory function. CONCLUSIONS: The inter- and intraobserver reliabilities of the Japanese Orthopedic Association scoring system for cervical myelopathy were high, suggesting that this system is useful for assessment of cervical myelopathy in comparative studies of treatment.

Activities of Daily Living↗
PubMed2001

Reduced myocardial sarcoplasmic reticulum Ca(2+)-ATPase mRNA expression and biphasic force-frequency relations in patients with hypertrophic cardiomyopathy.

BACKGROUND: The relationship between left ventricular (LV) contractile functional reserve and gene expression of Ca(2+)-handling proteins in patients with hypertrophic cardiomyopathy (HCM) remains to be clarified. METHODS AND RESULTS: We calculated the maximum first derivative of LV pressure (LV dP/dt(max)) and the LV pressure half-time (T(1/2)) during pacing in 14 patients with nonobstructive HCM (LV ejection fraction >55%) and 7 control subjects. Endomyocardial tissue was obtained, and mRNA levels of sarcoplasmic reticulum Ca(2+)-ATPase (SERCA2), ryanodine receptor-2, phospholamban, calsequestrin, and Na(+)/Ca(2+) exchanger were quantified by use of a real-time quantitative reverse transcription-polymerase chain reaction method. Group A consisted of 7 HCM patients who showed a progressive rise in the LV dP/dt(max) with increased heart rate. Group B consisted of 7 HCM patients in whom the heart rate-LV dP/dt(max) relation was biphasic at physiological pacing rates. Both the mean maximal wall thickness and the LV hypertrophy score in group B were greater than in group A (20+/-5 versus 15+/-3 mm and 7+/-1 versus 5+/-2 points, respectively). SERCA2 mRNA levels were significantly lower in group B (SERCA2/GAPDH ratio 0.34+/-0.15) compared with group A (0.72+/-0.27) and control subjects (0.85+/-0.47), whereas the mRNA expression of ryanodine receptor-2, phospholamban, calsequestrin, and Na(+)/Ca(2+) exchanger were similar in all groups. CONCLUSIONS: These results suggest that downregulation of SERCA2 mRNA, resulting in altered Ca(2+) handling, may contribute to impaired LV contractile reserve in HCM patients with severe hypertrophy, even in the absence of detectable baseline systolic dysfunction.

Adult↗
PubMed2001

Identification of nucleophosmin/B23, an acidic nucleolar protein, as a stimulatory factor for in vitro replication of adenovirus DNA complexed with viral basic core proteins.

The processes governing chromatin remodeling and assembly, which occur prior to and/or after transcription and replication, are not completely understood. To understand the mechanisms of transcription and replication from chromatin templates, we have established in vitro replication and transcription systems using adenovirus (Ad) DNA complexed with viral basic core proteins, called Ad core, as a template. Using this system, we have previously identified, from HeLa cells, template activating factor-I as a stimulatory factor for the Ad core DNA replication. Here, using this system as a tool, we identified and purified a novel template activating factor activity that consists of two acidic polypeptides whose apparent molecular masses are 38 kDa and 37 kDa. These two polypeptides correspond to two splicing variants of nucleolar phosphoprotein, nucleophosmin/B23. Recombinant B23 proteins stimulate the Ad core DNA replication, and the acidic regions of B23 proteins are important for its activity. In addition, B23 proteins directly bind to core histones and transfer them to naked DNA. Furthermore, chromatin components such as histones and topoisomerase II are co-immunoprecipitated with B23 from cell extracts. These observations lead to a hypothesis that nucleophosmin/B23 is involved in structural changes of chromatin, thereby regulating transcription and replication within the ribosomal DNA region or maintaining the nucleolar structure.

Adenoviridae↗
PubMed2001

Novel recognition mode between Vav and Grb2 SH3 domains.

Vav is a guanine nucleotide exchange factor for the Rho/Rac family that is expressed exclusively in hematopoietic cells. Growth factor receptor-bound protein 2 (Grb2) has been proposed to play important roles in the membrane localization and activation of Vav through dimerization of its C-terminal Src-homology 3 (SH3) domain (GrbS) and the N-terminal SH3 domain of Vav (VavS). The crystal structure of VavS complexed with GrbS has been solved. VavS is distinct from other SH3 domain proteins in that its binding site for proline-rich peptides is blocked by its own RT loop. One of the ends of the VavS beta-barrel forms a concave hydrophobic surface. The GrbS components make a contiguous complementary interface with the VavS surface. The binding site of GrbS for VavS partially overlaps with the canonical binding site for proline-rich peptides, but is definitely different. Mutations at the interface caused a decrease in the binding affinity of VavS for GrbS by 4- to 40-fold. The structure reveals how GrbS discriminates VavS specifically from other signaling molecules without binding to the proline-rich motif.

Adaptor Proteins, Signal Transducing↗
PubMed2001

Transduction of antisense cyclin D1 using two-step gene transfer inhibits the growth of rat hepatoma cells.

Cyclin D1, one of the G(1) cyclins, is frequently overexpressed in several types of carcinomas and is thought to play an important role in tumorigenesis and tumor progression including hepatocellular carcinoma. We constructed a retrovirus vector-carrying rat cyclin D1 cDNA in the reverse orientation, resulting in expression of antisense (AS) cyclin D1 mRNA. For efficient transduction of this recombinant retrovirus, two-step gene transfer was performed. The rat hepatoma cell line (dRLh84) was infected with this recombinant retrovirus after preinfection with adenovirus expressing the retrovirus receptor. In the rat hepatoma cells, AS cyclin D1 mRNA was expressed, inducing a decrease in the expression of endogenous cyclin D1 mRNA and an inhibition of cell growth. Moreover, two-step gene transfer of AS cyclin D1 into s.c. hepatoma xenografts resulted in inhibition of tumor growth and prolonged animal survival. In the virus-infected tumor xenografts, expression of cyclin D1 was immunohistochemically inhibited, and apoptosis of hepatoma cells was detected. These findings suggest that transduction of AS cyclin D1 is useful as an adjunct to standard treatments for hepatocellular carcinoma.

Animals↗
PubMed2001

Presence of IFN-gamma and IL-4 in human periapical granulation tissues and regeneration tissues.

To study mediators associated with the progression of disease and the process of bone regeneration in human apical periodontitis, we examined samples of periapical granulation tissues and regeneration tissues obtained from five patients by use of immunohistochemical methods. Periapical granulation tissues were found to contain a large number of CD4-positive T cells and CD68-positive monocytes/macrophages (CD4: 35.2%, CD68: 32.7%). The CD4-positive T cells and CD68-positive monocytes/macrophages were predominantly present in regeneration tissues (CD4: 62.1%, CD68: 16.0%). In these the percentages of CD4-positive T cells were higher as compared with periapical granulation tissues (from 35.2% to 62.1%). In periapical granulation tissues, CD4-positive T cells stained positively for interferon-gamma (IFN-gamma) and negatively for interleukin-4 (IL-4). In regeneration tissues, IL-4-producing cells could be detected. However, IFN-gamma-producing cells could not be detected. These results suggest that IFN-gamma and IL-4 may modulate the pathogenesis of infectious disease and the process of bone regeneration in local inflammation sites such as human apical periodontitis.

Adolescent↗
PubMed2001

A missense mutation of the Na+ channel alpha II subunit gene Na(v)1.2 in a patient with febrile and afebrile seizures causes channel dysfunction.

Generalized epilepsy with febrile seizures plus (GEFS+), a clinical subset of febrile seizures (FS), is characterized by frequent episodes beyond 6 years of age (FS+) and various types of subsequent epilepsy. Mutations in beta1 and alpha(I)-subunit genes of voltage-gated Na(+) channels have been associated with GEFS+1 and 2, respectively. Here, we report a mutation resulting in an amino acid exchange (R188W) [corrected] in the gene encoding the alpha-subunit of neuronal voltage-gated Na(+) channel type II (Na(v)1.2) in a patient with FS associated with afebrile seizures. The mutation R188W [corrected] occurring on Arg(187), a highly conserved residue among voltage-gated Na(+) channels, was not found in 224 alleles of unaffected individuals. Whole-cell patch clamp recordings on human embryonic kidney (HEK) cells expressing a rat wild-type (rNa(v)1.2) and the corresponding mutant channels showed that the mutant channel inactivated more slowly than wild-type whereas the Na(+) channel conductance was not affected. Prolonged residence in the open state of the R188W [corrected] mutant channel may augment Na(+) influx and thereby underlie the neuronal hyperexcitability that induces seizure activity. Even though a small pedigree could not show clear cosegregation with the disease phenotype, these findings strongly suggest the involvement of Na(v)1.2 in a human disease and propose the R188W [corrected] mutation as the genetic defect responsible for febrile seizures associated with afebrile seizures.

Amino Acid Substitution↗
PubMed2001

A novel serum protein that is selectively produced by cytotoxic lymphocytes.

Cytotoxic lymphocytes such as CTL and NK cells play principal roles in the host defense mechanisms. Monitoring these effector cells in vivo is helpful to understand the immune responses in disorders such as cancer and infectious diseases. In this study, we identified a novel secretory protein, killer-specific secretory protein of 37 kDa (Ksp37), as a Th1-specific protein by a subtractive cloning method between human Th1 and Th2 cells. In peripheral blood leukocytes, Ksp37 expression was limited to Th1-type CD4(+) T cells, effector CD8(+) T cells, gammadelta T cells, and CD16(+) NK cells. Most of these Ksp37-expressing cells coexpressed perforin, indicating that Ksp37 is selectively and commonly expressed in the lymphocytes that have cytotoxic potential. Ksp37 was released at constant rate from both unstimulated and stimulated PBMCs in vitro and also detected in normal human sera. In healthy individuals, serum Ksp37 levels were significantly higher in children (mean +/- SD; 984 +/- 365 ng/ml for age 0-9) than in adults (441 +/- 135 ng/ml for age 20-99), consistent with reported differences in the absolute counts of blood T and NK cells between children and adults. In patients with infectious mononucleosis, transient elevation of serum Ksp37 levels was observed during the early acute phase of primary EBV infection. These results suggest that Ksp37 may be involved in an essential process of cytotoxic lymphocyte-mediated immunity and that Ksp37 may also have clinical value as a new type of serum indicator for monitoring cytotoxic lymphocytes in vivo.

Adolescent↗
PubMed2001

Role of FK506-binding protein 12 in development of the chick embryonic heart.

A cDNA encoding chicken FK506-binding protein 12 (FKBP12) was isolated and sequenced. The predicted amino acid sequence of the chicken protein shows high homology to those of FKBP12 proteins of other species ranging from human to frog. The possible role of FKBP12 in chick embryonic cardiac development was examined. Northern blot analysis revealed that FKBP12 mRNA is distributed widely in chick embryos, being especially abundant in the heart; the amount of FKBP12 mRNA in the embryonic heart decreased with time. Administration of FK506 to chick embryos at 7 to 9 days resulted in marked cardiac enlargement. FK506 also reduced the expression of myosin, induced a more elongated cell morphology, and impaired network formation in cultured chick embryonic cardiomyocytes. These results suggest that FKBP12 is important in the regulation of contractile function and phenotypic expression in chick cardiomyocytes during embryonic development.

Amino Acid Sequence↗
PubMed2001

Gene therapy targeting for hepatocellular carcinoma: selective and enhanced suicide gene expression regulated by a hypoxia-inducible enhancer linked to a human alpha-fetoprotein promoter.

We previously reported that the retroviral vector expressing the herpes simplex virus-thymidine kinase gene under the control of 0.3-kb human alpha-fetoprotein (AFP) gene promoter (AF0.3) provided the cytotoxicity to ganciclovir (GCV) in high-AFP-producing human hepatoma cells but not in low-AFP-producing cells. Therefore, specific enhancement of AFP promoter activity is likely to be required to induce enough cytotoxicity in low-AFP-producing hepatoma cells. In this study, we constructed a hybrid promoter, [HRE]AF, in which a 0.4-kb fragment of human vascular endothelial growth factor 5'-flanking sequences containing hypoxia-responsive element (HRE) was fused to AF0.3 promoter. By means of the reporter gene transfection assay, hypoxia-inducible transcriptions that were mediated by [HRE]AF promoter were detected in low- and non-AFP-producing human hepatoma cells, but not in nonhepatoma cells. When the herpes simplex virus-thymidine kinase gene controlled by [HRE]AF promoter was transduced into hepatoma and nonhepatoma cells by a retroviral vector, the exposure to 1% O2 induced GCV cytotoxicity specifically in the hepatoma cells. Moreover, in nude mice bearing solid tumor xenografts, only the tumors consisting of the virus-infected hepatoma cells gradually disappeared by GCV administration. These results indicate that the hypoxia-inducible enhancer of the human vascular endothelial growth factor gene, which is directly linked to human AFP promoter, involves selective and enhanced tumoricidal activity in gene therapy for hepatocellular carcinoma.

Animals↗
PubMed2001

Upregulation of HSP47 and collagen type III in the dermal fibrotic disease, keloid.

Keloid is a dermal fibrotic disease characterized by excessive accumulation of mainly type I collagen in extracellular matrix of the dermis. We have studied the expression levels of collagen types I and III, and its molecular chaperone HSP47 in keloid lesions and surrounding unaffected skin using Northern and Western blotting and immunohistochemical analyses. Collagen types I and III mRNA levels were found to be upregulated 20-fold in keloid tissues, contradicting previous reports of nearly normal type III collagen levels in this disease. HSP47 expression in keloid lesions was also highly upregulated; eightfold at mRNA level and more than 16-fold at the protein level. Strong upregulation of these three proteins in keloid was confirmed by immunohistochemical staining. These results suggest that accumulation of both type I and type III collagen is important for the development of keloid lesions, and that HSP47 plays a role in the rapid and extensive synthesis of collagen in keloid tissues.

Adolescent↗
PubMed2001

Intraneural monophasic synovial sarcoma: a case report.

STUDY DESIGN: A case report. OBJECTIVES: To illustrate a rare case of synovial sarcoma arising within a peripheral nerve. SUMMARY OF BACKGROUND DATA: A synovial sarcoma arising within a peripheral nerve is very unusual. Only five cases of primary synovial sarcoma within a peripheral nerve have been reported. This is the first case with involvement of the nerve root. The authors diagnosed the tumor arising within the S1 nerve root as synovial sarcoma using cytogenetic analysis that detected the chimeric SYT/SSX gene. METHODS: In addition to the immunohistochemical study, a reverse transcription-polymerase chain reaction (RT-PCR) assay was conducted for the SYT-SS10 fusion gene using archival formalin-fixed paraffin-embedded tumor specimens. RESULTS: Computed tomography scan, magnetic resonance imaging performed before surgery, and the intraoperative findings showed that the tumor was embedded within the S1 nerve root. Although the histologic findings were suggestive of a malignant peripheral nerve sheath tumor, the results of the cytologic study confirmed its diagnosis of synovial sarcoma. CONCLUSION: Primary intraneural synovial sarcoma, although rare, must be distinguished from malignant peripheral nerve sheath tumor. The molecular assay of the detection of the SYT/SSX fusion gene is useful to make a definite diagnosis of monophasic synovial sarcoma.

Female↗
PubMed2001

Mnl1p, an alpha -mannosidase-like protein in yeast Saccharomyces cerevisiae, is required for endoplasmic reticulum-associated degradation of glycoproteins.

The endoplasmic reticulum (ER) has a mechanism to block the exit of misfolded or unassembled proteins from the ER for the downstream organelles in the secretory pathway. Misfolded proteins retained in the ER are subjected to proteasome-dependent degradation in the cytosol when they cannot achieve correct folding and/or assembly within an appropriate time window. Although specific mannose trimming of the protein-bound oligosaccharide is essential for the degradation of misfolded glycoproteins, the precise mechanism for this recognition remains obscure. Here we report a new alpha-mannosidase-like protein, Mnl1p (mannosidase-like protein), in the yeast ER. Mnl1p is unlikely to exhibit alpha1,2-mannosidase activity, because it lacks cysteine residues that are essential for alpha1,2-mannosidase. However deletion of the MNL1 gene causes retardation of the degradation of misfolded carboxypeptidase Y, but not of the unglycosylated mutant form of the yeast alpha-mating pheromone. Possible roles of Mnl1p in the degradation and in the ER-retention of misfolded glycoproteins are discussed.

Amino Acid Sequence↗