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S Takeda

Publications and source records attributed to S Takeda.

At least 343 records · Page 19Linked to original sources
PubMed1996

Induction of exon skipping of the dystrophin transcript in lymphoblastoid cells by transfecting an antisense oligodeoxynucleotide complementary to an exon recognition sequence.

In this paper we first report that exon skipping from the dystrophin gene transcript could be induced in living cells by an antisense oligodeoxynucleotide (ODN) complementary to an exon recognition sequence (ERS). Incubation of lymphoblastoid cells with an antisense ODN against the purine-rich region of dystrophin exon 19 resulted in skipping of the exon from the dystrophin transcript. Skipping of exon 19 started to appear after 6 hours of incubation, and complete skipping was observed after 24 hours of incubation. None of the other 78 dystrophin exons were skipped, and exon 19 skipping could be induced by the sense ODN or by an antisense ODN corresponding to another ERS. These results showed that antisense ODN against ERS can induce exon skipping even in living cells and ERS is functioning as an essential cis-element for proper splicing in dystrophin pre-mRNA.

Alternative Splicing↗
PubMed1996

Intrinsic signaling function of APP as a novel target of three V642 mutations linked to familial Alzheimer's disease.

APP695 is a transmembrane precursor of Abeta amyloid. In familial Alzheimer's disease (FAD), three mutations V642I/F/G were discovered in APP695, which has been suggested by multiple studies to be a cell surface signaling receptor. We previously reported that normal APP695 encodes a potential GO-linked receptor with ligand-regulated function and that expression of the three FAD mutants (FAD-APPs), not normal APP, induces cellular outputs by GO-dependent mechanisms. This suggests that FAD-APPs are constitutively active GO-linked receptors. Here, we provide direct evidence for this notion. Reconstitution of either recombinant FAD-APP with GO vesicles induced activation of GO, which was inhibitable by pertussis toxin, sensitive to Mg2+ and proportional in quantity to the reconstituted amounts of FAD-APP. Consistent with the dominant inheritance of this type of FAD, this function was dominant over normal APP, because little activation was observed in APP695-GO vesicles. Experiments with antibody competition and sequence deletion indicated that His657-Lys676 of FAD-APP, which has been specified as the ligand-dependent GO-coupling domain of normal APP, was responsible for this constitutive activation, confirming that the three FAD-APPs are mutationally activated APP695. This study identifies the intrinsic signaling function of APP to be a novel target of hereditary Alzheimer's disease mutations, providing an in vitro system for the screening of potential FAD inhibitors.

Alzheimer Disease↗
PubMed1996

Synthesis and pharmacological activity of triazole derivatives inhibiting eosinophilia.

In order to develop novel antiasthmatic agents based on a new mechanism of action, a series of 3-substituted 5-amino-1-[(methylamino)(thiocarbonyl)]-1H-1,2,4-triazole derivatives were synthesized and evaluated in a model in which eosinophilia was induced in the airway through intravenous (iv) injection of Sephadex particles on days 0, 2, and 5. After screening of several hundred derivatives, we finally identified the highly potent eosinophilia inhibitor 5-amino-3-(4-chlorophenyl)-1-[(methylamino)(thiocarbonyl)]-1H-tria zole (23c, GCC-AP0341), which had ID50 values of 0.3 and 0.07 mg/kg when administered orally (os) and intraperitoneally (ip), respectively. This compound showed complete inhibition of the hypersensitivity induced by ascaris inhalation at an ip dose of 1 mg/kg as well as low toxicity, with an LD50 value of > 2.0 g/kg in mice. Extensive study of its mechanism of action revealed that 23c inhibited eosinophil survival induced by interleukin-5 (IL-5), but had little or no effect on leukotriene D4 (LTD4) or platelet-activating factor (PAF)-induced responses. Taken together, these results suggest 23c as a novel candidate for the treatment of chronic asthma. Further studies are now underway.

Animals↗
PubMed1996

Prolongation of survival period and improvement of cancer cachexia by long-term administration of UFT.

We assayed the antitumoral and anticachectic activity of an oral fluoropyrimidine, UFT using the Colon-26-bearing murine cachexia model in terms of the survival period and parameters corresponding to clinical symptoms. Tumor growth was inhibited by UFT dose-dependently at the dose range of 12.5-25.0 mg/kg per day. Although UFT did not show significant growth inhibition at 15.0 and 12.5 mg/kg to which UFT gave little toxicity, the survival period was shown to be superior to the case of maximum tolerated dose (25.0 mg/kg per day). Next, we compared the maximum increase of life span (ILS) value for an administration schedule of continuous 9 days and 5 weeks which mimics the clinical schedule and found that the ILS value in the latter group was superior to the former and UFT improved cachexia, in the same manner. In the following experiments, we have clarified that UFT decreased the level of both plasma interleukin-6 (IL-6) and tumorous prostaglandin E2 (PGE2) and it highly accelerated IL-6 production from Colon-26. These findings suggest that UFT therapy, in low-toxic dose, could be useful to cachectic patients with poor performance status.

Animals↗
PubMed1996

Antitumor activity of 1 M tegafur-0.4 M 5-chloro-2,4-dihydroxypyridine-1 M potassium oxonate (S-1) against human colon carcinoma orthotopically implanted into nude rats.

The purpose of this study was to establish a nude rat orthotopic (organ-specific) human colorectal cancer model as an in vivo secondary screen for general evaluation of new anticancer agents against colorectal cancer and to evaluate practically the antitumor activity of 1 M tegafur-0.4 M 5-chloro-2,4-dihydroxypyridine-1 M potassium oxonate (S-1), a new p.o. fluoropyrimidine, in comparison to 1 M tegafur-4 M uracil [(UFT) effective on colorectal tumor in clinical]. After implantation of KM12C, a human colorectal cancer cell line, into the subserosal layer of the colon as a single-cell suspension, extensive local tumor growth and invasion to both the mucosal and the serosal sides were observed in all rats. Metastatic foci were also formed in both lymph nodes and lungs following local tumor growth in all of them. Using this method, an equitoxic dose of S-1 (15 mg/kg/day) and UFT (30 mg/kg/day) was administered p.o. for 14 consecutive days from 7 days after tumor cell implantation. S-1 showed a higher tumor growth inhibition than UFT did [S-1, 57% (significantly different from the tumor weight of the untreated group at P < 0.05) and UFT, 18% (P > 0.05)]. When both drugs were administered to nude rats bearing KM12C injected into the cecal wall for 28 consecutive days at equitoxic doses, the mean survival in the S-1 group was 16 days longer than that in the untreated group (P < 0.01) but that in the UFT group was only 8 days longer (P > 0.05). After the administration of an equitoxic dose of both drugs, S-1 gave the higher levels than UFT in various pharmacokinetic parameters as follows: area under the curve 0-24 h of 5-fluorouracil in plasma (3.5-fold), area under the curve 0-24 h of 5-fluorouracil incorporated into RNA in the tumor (1.3-fold), and thymidylate synthase inhibition rate (percentage) in the tumor (about 20%). Collectively, these findings suggested that this orthotopic human colorectal tumor model in nude rats is useful to evaluate the clinical therapeutic efficacy of drugs or therapies for colorectal cancer, and that S-1 had a higher therapeutic effect on human colorectal tumor than UFT did.

Adenocarcinoma↗
PubMed1996

G protein-mediated neuronal DNA fragmentation induced by familial Alzheimer's disease-associated mutants of APP.

Missense mutations in the 695-amino acid form of the amyloid precursor protein (APP695) cosegregate with disease phenotype in families with dominantly inherited Alzheimer's disease. These mutations convert valine at position 642 to isoleucine, phenylalanine, or glycine. Expression of these mutant proteins, but not of normal APP695, was shown to induce nucleosomal DNA fragmentation in neuronal cells. Induction of DNA fragmentation required the cytoplasmic domain of the mutants and appeared to be mediated by heterotrimeric guanosine triphosphate-binding proteins (G proteins).

Alzheimer Disease↗
PubMed1996

Kinetics of peptide binding to the bovine 70 kDa heat shock cognate protein, a molecular chaperone.

We have measured the kinetics of binding and release of a fluorescently labeled seven-residue peptide (fluorescein-FYQLALT) to recombinant bovine heat shock cognate protein (Hsc70); additionally, we have determined the effect of peptide binding on the kinetic rate constants of individual steps of the Hsc70 ATPase cycle. In the presence of MgADP, peptide binding is a two-step process; the first step results in a low-affinity peptide-Hsc70 complex (Kd calcd approximately 14 microM), while the second step locks the peptide into a higher-affinity complex (Kd = 4.3 microM). In the presence of MgATP, peptide binding is a one-step process which yields a peptide-Hsc70 complex with an affinity of approximately 40-50 microM. The bimolecular rates of initial peptide-Hsc70 association differ less than 2-fold in the presence of MgADP and MgATP. Peptide binding increases the rates of ATP hydrolysis and product release in the Hsc70 ATPase cycle. Taken together with earlier results, these data suggest a model for the interaction of Hsc70 with peptides in which (i) with MgATP there is significant interaction between the carboxy terminal peptide binding domain and the amino terminal ATPase domain of Hsc70 such that the effect of peptide binding is transmitted to the ATPase domain (resulting in increased rates of ATP hydrolysis and product release) and, reciprocally, the ATPase domain constrains the peptide binding domain to a low-peptide affinity conformation; and (ii) with MgADP, the peptide binding domain is less constrained by the ATPase domain, allowing capture of peptides in complexes with significantly slower "off " rates than in the presence of MgATP.

Adenosine Diphosphate↗
PubMed1996

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↗
PubMed1996

Expression of V642 APP mutant causes cellular apoptosis as Alzheimer trait-linked phenotype.

APP is a transmembrane precursor of beta-amyloid. In dominantly inherited familial Alzheimer's disease (FAD), point mutations V6421, V642F and V642G have been discovered in APP695. Here we show that expression of these mutants (FAD-APPs) causes a clone of COS cells to undergo apoptosis associated with DNA fragmentation. Apoptosis by the three FAD-APPs was the highest among all possible V642 mutants; normal APP695 had no effect on apoptosis, suggesting that apoptosis by APP mutants in this system is phenotypically linked to the FAD trait. FAD-APP-induced apoptosis was sensitive to bcl-2 and most probably mediated by heteromeric G proteins. This study presents a model system allowing analysis of the mechanism for FAD-APP-induced cytotoxicity.

Alzheimer Disease↗
PubMed1996

The natural history of herniated nucleus pulposus with radiculopathy.

STUDY DESIGN: The present study retrospectively investigated the morphologic changes that occurred during conservative treatment of patients with unilateral leg pain resulting from herniated nucleus pulposus without significant lumbar canal stenosis. OBJECTIVES: The results were correlated with clinical outcomes and extruding forms to determine which type of herniated nucleus pulposus had the greatest capacity for spontaneous regression and how rapidly such regression might occur. SUMMARY OF BACKGROUND DATA: The study population consisted of 77 patients with radiculopathy. METHODS: All patients complained primarily of unilateral leg pain, and 94% had positive tension signs. Additionally, 32% exhibited muscle weakness corresponding to the symptomatic nerve root. All patients were studied more than twice using magnetic resonance imaging during conservative therapy at a mean interval of 150 days. Morphologic changes on magnetic resonance imaging fell into four categories, with herniated nucleus pulposus classified into three types using T1-weighted sagittal views. Each patient was reexamined on the same scanner; 53 patients were examined twice, and 24 patients were examined more than three times. RESULTS: Morphologic changes, with the exception of 13 false-negative cases, basically corresponded to clinical outcome. In half of the cases that showed some improvement at follow-up evaluation, improvement of clinical findings were seen before those observed on magnetic resonance imaging. Migrating herniated nucleus pulposus frequently presented an obvious decrease in size, and even disappearance in seven cases. The further the herniated nucleus pulposus migrated, the more decrease in size could be observed. The cases apparently corresponding to "protrusion" showed little or no change on follow-up magnetic resonance imaging. Regarding the mechanism of herniated nucleus pulposus disappearance, exposure to the vascular supply undoubtedly took a part, although many factors were suspected to have some influence. CONCLUSION: Morphologic changes on magnetic resonance imaging mainly corresponded to clinical outcomes but tended to lag behind improvement of leg pain. Disappearance of herniate nucleus pulposus was seen frequently in the cases of migrating disc herniation, and it was presumed that exposure to the vascular supply had a lot to do with this phenomenon.

Adolescent↗
PubMed1996

Effects of a synthetic vitamin D analog, ED-71, on bone dynamics and strength in cancellous and cortical bone in prednisolone-treated rats.

To determine the action of corticosteroid on bone metabolism and assess the effects of a synthetic vitamin D analog, ED-71, on them, 56 SD rats, 8 weeks of age, were assigned to seven groups of eight animals each. Group 1 was the basal control. Group 2 was the nontreated control. Groups 3-7 were given prednisolone at 30 mg/kg of body weight (BW) twice a week and concomitantly administered ED-71 with respective doses of 0, 0.0125, 0.025, 0.05, and 0.1 micrograms/kg of BW for 12 weeks. In group 3, urinary calcium (U-Ca) and deoxypyridinoline (U-Dpy) were significantly increased compared with group 2. In groups 4-7, U-Ca values were increased but U-Dpy values were dose-dependently decreased. Age-dependent increases in the parameter values of BMD, compressive strength, trabecular bone volume (BV/TV), and trabecular thickness (Tb.Th) of the lumbar body were significantly suppressed in group 3 but dose-dependently increased in groups 4-7, and the values of group 7 exceeded those of group 2. The parameters of bone mineral density (BMD) and the bending strength of the femur in groups 4-7 were larger than the values in group 3 but did not reach the levels of group 2. The trabecular bone formation rate (BFR/BS) of the lumbar body measured by calcein labeling in group 3 was reduced when compared with group 2, but the values were not further decreased in groups 4-7. The perimeter ratios of double labels over single labels (dLS/sLS) greatly decreased by prednisolone, were dose-dependently increased to the level of the normal control by ED-71. Double-labeled perimeters and the dLS/sLS ratios were also increased in the periosteal envelope of the midfemur. These findings clearly demonstrate that prednisolone administration affects the age-related changes in bone metabolism, and ED-71 administration counteracts the effects by increasing intestinal calcium absorption, reducing bone resorption, and enhancing mineralization. The action of ED-71, however, seems to be less potent in the cortical bone.

Absorptiometry, Photon↗
PubMed1996

In vitro and in vivo analysis of human leukocyte binding by the antitumor polysaccharide, lentinan.

Lentinan (LNT), a (1-->3)-beta-D-glucan with (1--6)-beta-D-glucopyranoside branches, has marked antitumor effects in syngeneic and autochtonous hosts. Clinically, LNT has proved effective with chemotherapeutic agents in patients with recurrent gastric and colorectal cancer. However, the mechanism that triggers subsequent immunologic reactions remains obscure. We hypothesized that LNT must first bind to the host cells. Accordingly, we analyzed LNT binding to host cells in healthy volunteers after incubating their cells under a variety of conditions as well as intravenously injecting LNT then subjecting them to flow cytometry and immunofluorescent staining using monoclonal antibody (anti-LNT mAb). LNT bound to monocytes and neutrophils, but not to lymphocytes in vitro. The most avid LNT binding was to monocytes. The percentage of LNT-bound monocytes after 60 min incubation at 4 degrees C was greater than that at 37 degrees C. The binding of LNT to monocytes was inhibited slightly by anti-iC3b receptor (anti-CR3) mAb, strongly by anti-C3b receptor (anti-CR1) mAb, and completely by anti-CR1 and anti-CR3 mAb together. The percentages of LNT-binding monocytes in the peripheral blood increased significantly 3 and 4 after 2 mg LNT-injection and returned to low levels 5 h later. However, no increase in LNT-binding neutrophils and lymphocytes was observed. We concluded that binding of LNT to human monocytes may initiate the influence of this compound on the immune system and differ between individuals. Its binding site may be similar to the C3b receptor.

Adult↗
PubMed1996

The N-terminal 303 amino acids of the human cytomegalovirus envelope glycoprotein B (UL55) and the exon 4 region of the major immediate early protein 1 (UL123) induce a cytotoxic T-cell response.

We reported earlier that an adenovirus (Ad) recombinant expressing the full-length human cytomegalovirus (HCMV) glycoprotein B (gB) gene induces gB-specific cytotoxic T lymphocyte (CTL) responses in CBA (H-2k) mice (Berencsi et al., J. Gen. Virol. 74, 257-2512, 1993). Here we show that mice immunized with Ad recombinant viruses expressing truncated forms of the gB gene containing the first 700 (Ad-700), 465 (Ad-465) or 303 (Ad-303) amino acids of gB or an Ad construct containing exon 4 (E4) of the HCMV immediate early 1 (IEI) gene (Ad-IEI (E4)) demonstrate HCMV-specific CTL responses. These data suggest the importance of the first 303 amino acids of the gB polypeptide and the IEI E4 product in designing a vaccine to induce anti-HCMV CTL responses.

Animals↗
PubMed1996

Reduction of serum IgG level and peripheral T-cell counts are correlated with CTG repeat lengths in myotonic dystrophy patients.

Myotonic dystrophy (DM) is an autosomal dominant multisystem disorder associated with expansion of the CTG repeat within the 3' non-coding region of the myotonin protein kinase (MT-PK) gene. CTG repeat length has been shown to correlate with the clinical category and age at onset of the disease. The relationship between CTG repeat length and immunological parameters were analyzed in this study. We determined CTG repeat length in 14 DM patients and 15 normal controls using Southern and PCR analyses, and then correlated their CTG repeat lengths with their serum immunoglobulin (IgG, IgA, IgM) levels and the number of peripheral white blood cells, including lymphocyte subsets. In DM patients, increasing CTG repeat lengths correlated significantly with decreasing serum IgG levels, decreasing total lymphocyte counts, and decreasing CD2+, CD3+, and CD4+ cell counts. Immunological parameters were also influenced by the expansion of CTG repeat in DM patients.

Adult↗
PubMed1996

Hearing impairment among young Chinese in a rural area.

To evaluate hearing levels in Chinese young people, audiometry was carried out at a rural village in Shandong Prefecture. The subjects were 282 healthy school children and students ranging in age from 7-17 y. All subjects were asked to complete a brief questionnaire on otological symptoms, personal histories and use of noisy playthings. Audiometric threshold testing was performed at the audiometric frequencies of 0.5, 1, 2, 4 and 8 kHz. Cluster analysis was used to estimate the associations between questions in the questionnaire and hearing impairment. Fifty-six subjects (20% subjects) were excluded from the normal groups. Twenty-two ears of the excluded subjects showed 4 kHz-dip and 38 ears showed high frequency hearing loss. An increased prevalence of hearing impairment was found when compared with young Japanese (1% from the nationwide school health survey) and with young Chinese in Shandong Prefecture (0.5%). In the questionnaire, 4 questions on dizziness, head trauma, aminoglycoside administration, and suspicion of Meniere's syndrome, were included in the cluster of hearing impairment. The cause of this hearing impairment was proposed to be the potentiating effects of aminoglycoside antibiotics and exposure to noise.

Adolescent↗