Search PubMed⌕ Search

Biomedical subjects

K Takagi

Publications and source records attributed to K Takagi.

At least 253 records · Page 14Linked to original sources

Molecular analysis of the FHIT gene at 3p14.2 in lung cancer cell lines.

Chromosome 3p is frequently deleted in various cancers including examples in the lung. A novel gene, termed FHIT, was recently isolated from the fragile site at 3p14.2, with aberrant transcripts being reported in lung cancer tumor specimens. To avoid overlooking tumor-specific altered transcripts due to contaminating normal cells in primary tumors, FHIT alterations were examined in 41 lung cancer cell lines in the present study. Lack of detectable expression or exclusive expression of aberrantly spliced transcripts, often accompanied by intragenic homozygous deletions, were observed in 7 of 24 non-small cell lung cancers (29%) but in 0 of 17 small cell lung cancers (0%). Extensive reverse transcription-PCR-single-strand conformation polymorphism analysis revealed polymorphisms and alternative splicing but failed to identify point mutations. These results suggest distinct mechanisms for FHIT alterations in lung tumorigenesis and that further studies of this interesting gene are warranted.

Acid Anhydride Hydrolases↗

Purification and characterization of nuclear alkaline phospholipase A2 in rat ascites hepatoma cells.

The alkaline phospholipase A2 (PLA2) was purified from nuclei of rat ascites hepatoma cells (AH7974) by column chromatography with a Sephacryl S-300 column and an immunoadsorbent using anti-group II PLA2 monoclonal antibody. From these two columns, the alkaline PLA2 was eluted in parallel with a 17-kDa protein which is reactive to another anti-group II PLA2 polyclonal antibody. Approximately 80% of nuclear PLA2 was inhibited by this antibody. The alkaline PLA2 was found in association with the chromatin fraction among subnuclear fractions. By an immunocytochemical staining, the nuclei of AH7974 were stained more strongly than other parts of cells with anti-group II PLA2 antiserum.

Animals↗

Allelic-expression imbalance of the insulin-like growth factor 2 gene in hepatocellular carcinoma and underlying disease.

It has been well documented that the liver is an exceptional organ in which the monoallelic expression of insulin-like growth factor 2 (IGF2) due to genomic imprinting is relaxed during the postnatal period, resulting in biallelic expression thereafter. In the present study, changes in the status of genomic imprinting were examined in 15 hepatocellular carcinomas (HCCs) as well as in 29 liver biopsies of chronic hepatitis or liver cirrhosis without clinical evidence of HCC, following screening for heterozygotes with an ApaI polymorphism in IGF2 in 34 HCCs and 80 such non-HCC cases. Extreme allelic-expression imbalance, leading to restoration of monoallelic IGF2 expression, was observed in 15 (100%) of 15 informative HCCs for the polymorphism with this monoallelic IGF2 expression appearing to be non-random from the paternal allele. Interestingly, the same allelic-expression imbalance was also present in a significant fraction of noncancerous liver specimens of patients with underlying disease known to be associated with HCC development. In contrast, the status of genomic imprinting of H19, another gene closely mapped at 11p15 under opposite imprinting, was strictly maintained in seven (100%) of seven cases informative for an RsaI polymorphism of H19. Together with the previous reports on altered genomic imprinting of IGF2 and H19 in embryonal lesions such as Wilms tumors as well as in lung cancers, the results suggest that perturbations of imprinting status occur as locus and tumor-type specific events in the development of human cancers.

Alleles↗

Selective maternal-allele loss in human lung cancers of the maternally expressed p57KIP2 gene at 11p15.5.

Genomic imprinting at 11p15 is suggested to play a role in certain pediatric tumors such as Wilms' tumor, based on the findings of selective maternal loss of this chromosomal region. Although the allele loss at 11p15 is also frequent in a number of cancers of adults including lung, breast, and bladder cancers, possible involvement of genomic imprinting in these tumors has not been investigated extensively. p57KIP2, a newly described member of the p21 cyclin-dependent kinase (CDK) inhibitor family which is thought to negatively regulate the cell cycle at the G1 checkpoint, has been mapped to 11p15. In the present study, we searched for somatic p57KIP2 mutations in lung cancer, but failed to find such alterations. Interestingly, however, we found that the p57KIP2 gene is imprinted with maternal expression and that the maternal alleles had been selectively lost in 11 of 13 (85%) lung cancer cases carrying 11p15 deletions, this being a significant bias (p=0.01). These data provide the first evidence that genomic imprinting may play a role in the oncogenesis of not only rare pediatric tumors but also this common cancer of adults, suggesting that the imprinted p57KIP2 CDK inhibitor gene is a potential target for maternally biased 11p15 deletions.

Adult↗

Histamine release induced by human natriuretic peptide from rat peritoneal mast cells.

We have been interested in the effects of some popular peptides on tracheal smooth muscle. Previously, we reported that atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP) and C-type natriuretic peptide (CNP) had dose-dependent relaxant effects on guinea pig tracheal smooth muscle. In this study, we compared the effects of ANP, BNP and CNP on histamine release from rat peritoneal mast cells. ANP and BNP were more potent than CNP, dose-dependently increasing histamine release at a concentration of 10(-7) M or higher. CNP induced histamine release at a concentration of 10(-6) M or higher. Extracellular calcium inhibited the histamine release induced by all 3 peptides. In conclusion, the effects of these 3 peptides in rat peritoneal mast cells demonstrated adverse reactions for respiratory diseases, although our previous results showed that these peptides caused relaxation of guinea pig tracheal smooth muscle. We should note that the drugs have different actions in each organ.

Amino Acid Sequence↗

Structure and expression of the mouse necdin gene. Identification of a postmitotic neuron-restrictive core promoter.

Necdin is a 325 amino acid residue protein encoded by a cDNA clone isolated from neurally differentiated embryonal carcinoma cells. In situ hybridization histochemistry revealed that necdin mRNA-containing cells in vivo coincided with postmitotic neurons in the mouse brain from early periods of neurogenesis until adulthood. To study the regulation of necdin gene expression, we have isolated and characterized the necdin gene from a mouse genomic DNA library. The necdin gene contains no intron, and its upstream region lacks canonical TATA and CAAT boxes. To assess promoter activity, the 5'-flanking sequence (844 base pairs) of the necdin gene was fused to the LacZ reporter gene and transiently transfected into retinoic acid-treated P19 embryonal carcinoma cells. Most of the transfectants expressing high levels of LacZ immunoreactivity were postmitotic neurons differentiated from P19 cells. Deletion analysis using luciferase reporter genes demonstrated that a neuron-restrictive core promoter is localized to positions -80 to -35, in which a G+C-rich domain and a putative binding site for transcription factors with PAS (per, arnt, and single-minded) dimerization domain are comprised. These results suggest that postmitotic neuron-restrictive expression of the necdin gene is mediated by the specific cis-acting elements and that this promoter is applicable to postmitotic neuron-targeted expression of various transgenic systems.

Amino Acid Sequence↗

Mesenchymal chondrosarcoma of the rib: report of a case.

Mesenchymal chondrosarcoma is a rare malignant cartilaginous tumor arising within the bone or soft tissue. An 18-year-old woman presented with a tumor on her left fourth rib. We performed a wide resection of the tumor and administered three cycles of postoperative adjuvant chemotherapy. Three years after the operation, the patient is alive without any evidence of either local recurrence or distant metastases. The findings of this case may thus support the usefulness of a radical resection and adjuvant chemotherapy for mesenchymal chondrosarcoma.

Adolescent↗

Periosteal chondroma developing in a rib at the side of a chest wall wound from a previous thoracotomy: report of a case.

We describe herein the case of a 45-year-old man who developed a periosteal chondroma in a rib at the site of a thoracotomy that had been performed 24 years previously. To our knowledge, this is only the third case of a periosteal chondroma in a rib to be documented in the world literature. Some authors have suggested that trauma, including that of surgery, may induce chondroma formation and this association could have been an important contributing factor in the induction of the tumor in this patient.

Bone Neoplasms↗

Relationship between pretreatment viremia level and response to interferon-alpha therapy in chronic hepatitis C differs in viral type 1 and 2 infections.

To determine the contribution of virus-related factors to long-term remission of chronic hepatitis C infection, we analyzed viral type and viremia level in 185 patients who had undergone a six-month course of interferon-alpha therapy. These virus-related factors were measured by an enzyme-linked immunosorbent assay with use of viral type-specific antigens and the branched DNA (bDNA) signal amplification assay, respectively. Sustained and long-term sustained responses were achieved in 55% and 50% of the patients, respectively. Transient or no responses were observed in 30% and 15% of the patients, respectively. Thirty-five percent of viral type 1 patients and 82% of viral type 2 patients had long-term sustained responses. Forty-two percent of bDNA-positive and 71% of bDNA-negative patients experienced long-term sustained responses. On multivariate analysis, viral type, Knodell's intralobular score, and viremia level were strong independent predictors of long-term sustained response (P < 0.0001, = 0.0060, and 0.037, respectively). Viremia level, however, was a significant predictor only in viral type 1, not type 2, patients. The relation between pretreatment viremia level and response to interferon-alpha therapy in chronic hepatitis C differs in viral type 1 and 2 infections.

Chronic Disease↗

Administration of neutralizing antibody against rabbit IL-1 receptor antagonist exacerbates lipopolysaccharide-induced arthritis in rabbits.

Endogenous IL-1 receptor antagonist (IL-1ra) may down-regulate part of IL-1 actions. We examined the participation of endogenous IL-1ra in the production of IL-1 beta in vitro. Macrophages cultured on adherent IgG produced a 100-fold molar excess of IL-1ra, compared with IL-1 beta. In the presence of a neutralizing monoclonal antibody (mAb) against rabbit IL-1ra, the production of antigenic IL-1 beta increased by 20-60%. Since the molar ratio of IL-1ra over IL-1 was 160- to 400-fold in synovial fluid (SF) of lipopolysaccharide (LPS)-induced arthritis, we examined the functional role of endogenous IL-1ra in the regulation of inflammatory responses. When measured in the presence of anti-IL-1ra mAb, masked IL-1 activity in SF became evident, with a 3- to 4-fold increment. The administration of anti-IL-1ra mAb with LPS into rabbit knee joints increased the IL-1 activity 4-fold and the production of antigenic IL-1 beta by 30-50%. The treatment also enhanced by 20-40% LPS-induced leukocyte infiltration and protein leakage. Therefore, endogenous IL-1ra apparently acts as a down-regulating factor for limiting deleterious effects of IL-1 by masking the biological activity and by inhibiting the production.

Animals↗

Pathophysiological effect of hepatic ischemia and reperfusion after hepatectomy in dogs with obstructive jaundice, focusing on the effect of coenzyme Q10 and styrene-co-maleic acid superoxide dismutase.

The purpose of the present study was to elucidate the effect of hepatic reflow following ischemia on the remnant liver after hepatectomy with occluded hepatic blood inflow in dogs with obstructive jaundice. When 40% hepatectomy was performed with 10-min occlusion of hepatic blood inflow in dogs with obstructive jaundice, the lipid peroxide content in the remnant liver increased significantly, together with a reduction in superoxide dismutase (SOD)-like activity. The levels of endotoxin and beta-N-acetyl hexosaminase (NAH) in peripheral blood also increased. The phagocytic index increased transiently after 30 min, followed by a marked decrease after 3h. Histologically, degeneration and necrosis of the hepatic parenchymal cells were demonstrated, and survival rate at 7 days was only 23.1%. With the administration of coenzyme Q10 (CoQ10) or styrene-co-maleic acid SOD (SM-SOD), these phenomena were significantly inhibited, and the survival rate improved. After hepatectomy, Kupffer cells in the remnant liver were activated by increased endotoxin levels in the portal vein, inducing the production of free radicals, which, in turn, damaged the Kupffer cells by reducing endotoxin clearance. Finally, the impaired functional reserve in the remnant liver provoked liver failure. The administration of CoQ10 or SM-SOD prevented the occurrence of these phenomena triggered by the free radicals generated by Kupffer cells, stimulated by endotoxin in the portal vein.

Animals↗

Acute stretching of peripheral nerves inhibits retrograde axonal transport.

The conjugation of horseradish peroxidase with wheat germ agglutinin was used to identify the effect on retrograde axonal transport of stretching the rat sciatic nerve indirectly by 10% and 20% femoral lengthening with a unilateral external fixator. To investigate the relationship between retrograde axonal transport and blood flow in the stretched nerve, nerve blood flow in the sciatic nerve was measured by a hydrogen washout technique. At 11% strain (20% femoral lengthening), the numbers of horseradish peroxidase-labelled motor neuron cells and nerve blood flow had decreased by 43% and 50%, respectively. Histological examination demonstrated ischaemic changes, but not mechanical damage. However, at 6% strain (10% femoral lengthening) there were no significant abnormalities. These findings suggest that the inhibition of retrograde axonal transport can be induced by acute stretching of the peripheral nerve and that circulatory disturbance is the main cause of the inhibition of retrograde axonal transport at the low strain.

Animals↗

Tenosynovial giant-cell tumor arising from the anterior cruciate ligament of the knee.

The localized form of tenosynovial giant-cell tumor is rarely located intraarticularly, especially in the large weight-bearing joints. We report the first case of localized, intraarticular tenosynovial giant-cell tumor arising from the anterior cruciate ligament of a knee in which locking and effusion had occurred. After arthroscopic removal of this tumor, the patient became asymptomatic.

Adult↗

Increased contribution by myofibrillar protein to whole-body protein breakdown according to severity of surgical stress.

A study was conducted to clarify the contribution by myofibrillar protein to whole-body protein breakdown in surgically stressed patients. Thirteen patients who underwent esophagectomy (group E) and 22 who underwent gastric or colorectal operation (group GC) were studied. Patients were all male and younger than 65 y old. Whole-body protein breakdown was determined using constant infusion of 15N-glycine. Urinary excretion of total catecholamines and 3-methylhistidine (3-MH) were measured. Amino acid composition of femoral arterial and venous blood was also analyzed. All the patients were fed exclusively by total parenteral nutrition providing 1.5 g protein and 40 kcal.kg-1.d-1 throughout the study. Whole-body protein breakdown increased significantly in group E (P < 0.01) and group GC (P < 0.05) on the 3rd postoperative day. The increase was significantly greater in group E than group GC (P < 0.01). Urinary excretion of 3-MH also increased significantly in group E (P < 0.01) and in group GC (P < 0.01) on the 3rd postoperative day. The increase was also greater in group E than group GC (P < 0.01). The ratio of urinary 3-MH excretion to whole-body breakdown protein (mumol/g), which is a indicator for the contribution of myofibrillar protein to the whole-body protein breakdown, increased significantly from 0.84 +/- 0.30 of preoperative value to 1.79 +/- 0.38 in group E (mean +/- SD; P < 0.01) and 1.42 +/- 0.18 in group GC (P < 0.05) on the 3rd postoperative day. This ratio was significantly higher in group E (P < 0.05). Furthermore, the ratio of myofibrillar to whole-body protein breakdown correlated significantly with urinary excretion of total catecholamines (r = 0.546; P < 0.01). Therefore, the contribution of myofibrillar protein to whole-body protein breakdown increased proportionately with the severity of surgical stress. On the other hand, femoral-arteriovenous differences of BCAA, Ala, Gln, Tyr, and Phe correlated significantly with the urinary excretion of 3-MH. These data suggest that skeletal muscle protein degradation is proportional to the breakdown of total myofibrillar proteins and both correlate with the severity of stress. From these data, it may be suggested that the contribution of skeletal muscle to whole-body protein catabolism is increased postoperatively, and that the increase is correlated with the severity of surgical stress.

Alanine↗

Tyrosine phosphorylation of 100-130 kDa proteins in lung cancer correlates with poor prognosis.

To search for the signalling pathways in lung cancer relevant to its aggressive behaviour, we studied tyrosine phosphorylated proteins in lung cancer cell lines and surgical specimens. We found that the profiles of protein phosphorylation were closely matched among these cell lines and cancer tissues of different histological origins, and 100-130 kDa proteins were the major components of phosphorylated proteins. In surgical specimens, approximately half of the cases showed tyrosine phosphorylation of these proteins in a tumour-specific manner, and phosphorylation of these proteins showed good correlation with the survival length of patients after operation. By immunoprecipitation with specific antibodies, we found that p125FAK, p120 and beta-catenin were the major components of tyrosine-phosphorylated proteins in the surgical specimens. These results suggest that tyrosine phosphorylation of these proteins may play a role in tumour relapse and is available as a clinical marker.

Aged↗

Late-onset hereditary ataxia with global thermoanalgesia and absence of fungiform papillae on the tongue in a Japanese family.

Two Japanese male siblings, aged 68 and 59 years, affected by late-onset progressive ataxia distinguished by extensive sensory and mild autonomic disturbances are described. They had global thermoanalgesia, positive Romberg signs, sensorineural deafness, canal paresis and ageusia. Their autonomic disturbances consisted of absence of overflow tears with usual stimuli, dysphagia, blood pressure and vasomotor instability, diarrhoea/constipation, and urinary frequency. Sensory nerve action potentials were completely absent, whereas motor conduction velocity was slightly reduced only in the lower extremities. Sural nerve biopsy on the younger brother demonstrated a marked loss of myelinated fibres and a reduction in the number of unmyelinated axons. Tongue histology revealed absence of fungiform papillae and taste buds. Autonomic function tests showed widespread but mild sympathetic and parasympathetic failures. Neuro-imaging studies revealed atrophy of the spinal cord, cerebellum, brainstem and corpus callosum, and enlargement of the lateral, third and fourth ventricles. These siblings represent a previously unrecognized variant of late-onset hereditary spinocerebellar degeneration with global thermoanalgesia and absence of fungiform papillae on the tongue.

Biopsy↗

Clinical application of the Biotrack 516 system for determination of theophylline by a turbidimetric latex agglutination inhibition reaction.

Several automated analytical systems for therapeutic drug monitoring (TDM) have been developed. In the present study, theophylline concentration in plasma was measured by the Biotrack 516 system for theophylline, a newly developed automated system based on the turbidimetric latex agglutination inhibition reaction, using whole blood samples obtained from 35 asthmatic patients receiving chronic theophylline therapy. The data were compared with those obtained by high-performance liquid chromatography (HPLC) and fluorescence polarization immunoassay (FPIA). Within-day and between-day precisions for the Biotrack system using blood samples obtained from nine patients ranged from 4.1 to 5.8% and from 2.0 to 6.2%, respectively. Comparison of this system with HPLC and FPIA methods indicated good correlation coefficients of > 0.960, while the respective slope and intercept did not differ from unity and zero. No cross-reactivity of this system with the main metabolites of theophylline and caffeine was observed, thus indicating that the antibodies possess specificity for theophylline. These findings suggest that the Biotrack-516 system is a method that enjoys both accuracy and precision to the same degree as established methods and hence will prove useful in the routine monitoring of plasma theophylline concentrations.

Anti-Asthmatic Agents↗

Stabilometric assessment in the anterior cruciate ligament-reconstructed knee.

OBJECTIVE: To examine the hypotheses that anterior cruciate ligament (ACL) reconstruction improves the proprioception of the knee beyond the level of ACL-deficient knees, and that proprioception of the knee correlates well with knee function after ACL reconstruction. PATIENTS: Fifty-three patients with ACL-reconstructed knees (22 men and 31 women), 30 physically active healthy volunteers with normal knees (15 men and 15 women), and 30 patients with chronic ACL-deficient knees (15 men and 15 women). MAIN OUTCOME MEASURES: A stabilometric assessment, which is considered to be a useful method for evaluating proprioception objectively, was used to compare the one-leg standing balance among three groups; and the relationship between subjective knee function, satisfaction, hop index, knee laxity, isokinetic thigh muscle strength, and one-leg standing balance in the ACL-reconstructed patients was also analyzed. RESULTS: The one-leg standing balance of the patients with ACL-reconstructed knees was still impaired compared with that of healthy volunteers (men, p < 0.05; women, p < 0.01), but significantly better than that of the patients with ACL-deficient knees (men, p < 0.001; women, p < 0.001). The one-leg standing balance of the patients with ACL-reconstructed knees correlated well with their functional outcomes such as subjective knee function (men, p < 0.001; women, p < 0.01), satisfaction (men, p < 0.01; women, p < 0.001), and hop index (men, p < 0.001; women, p < 0.001), whereas poor correlation was seen between functional outcomes and mechanical stability. CONCLUSIONS: The results suggest that knee function after ACL-reconstruction should be closely related with knee proprioception, and indicate that the usefulness of stabilometric assessment in the evaluation of the function of ACL-reconstructed knees.

Adolescent↗