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1.
Allergol Int ; 63(3): 457-66, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24851949

RESUMO

BACKGROUND: Rapamycin has been reported to inhibit mesenchymal cell proliferation in a murine model of pulmonary fibrosis. In the present study, we examined the effects of rapamycin on vascular remodeling including intraluminal myofibroblast proliferation in a murine model of allergic vasculitis with eosinophil infiltration. METHODS: C57BL/6 mice were sensitized with ovalbumin (OVA) and alum. The positive controls were exposed to aerosolized OVA daily for 7 days. The other group of mice was administered with rapamycin (1mg/kg) intraperitoneally, in parallel with daily exposure to aerosolized OVA for 7 days. On the 3rd and 7th day, bronchoalveolar lavage (BAL) was performed and the lungs were excised for pathological analysis. Cell differentials were determined and concentrations of IL-4, IL-5, IL-13 and TGF-ß in the BAL fluid (BALF) were measured. Semi-quantitative analysis of pathological changes in the pulmonary arteries was evaluated according to the severity of vasculitis. RESULTS: The number of eosinophils in BALF was reduced significantly in the mice treated with rapamycin compared to the positive control. There was a significant decrease in the TGF-ß concentration of the BALF in the rapamycin-treated group compared to that of the positive control. The pathological scores were reduced significantly in the rapamycin-treated group compared to the positive control group. Intraluminal myofibroblasts in pulmonary arteries were reduced dramatically in the rapamycin-treated group compared to the positive control group. CONCLUSIONS: Rapamycin suppressed pulmonary vascular remodeling in a murine model of allergic vasculitis with eosinophil infiltration through reducing eosinophil infiltration and TGF-ß production in the lung and inhibition against biological action of TGF-ß.


Assuntos
Hipersensibilidade/tratamento farmacológico , Imunossupressores/administração & dosagem , Pneumopatias/tratamento farmacológico , Artéria Pulmonar/efeitos dos fármacos , Sirolimo/administração & dosagem , Fator de Crescimento Transformador beta/metabolismo , Remodelação Vascular/efeitos dos fármacos , Vasculite/tratamento farmacológico , Animais , Proliferação de Células/efeitos dos fármacos , Modelos Animais de Doenças , Progressão da Doença , Eosinófilos/efeitos dos fármacos , Eosinófilos/patologia , Feminino , Humanos , Hipersensibilidade/imunologia , Pneumopatias/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Miofibroblastos/efeitos dos fármacos , Miofibroblastos/fisiologia , Artéria Pulmonar/patologia , Vasculite/imunologia
2.
Nucleic Acids Res ; 38(12): e133, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20406772

RESUMO

Estrogen-DNA adducts are potential biomarkers for assessing the risk and development of estrogen-associated cancers. 4-Hydroxyequilenin (4-OHEN) and 4-hydroxyequilin (4-OHEQ), the metabolites of equine estrogens present in common hormone replacement therapy (HRT) formulations, are capable of producing bulky 4-OHEN-DNA adducts. Although the formation of 4-OHEN-DNA adducts has been reported, their quantitative detection in mammalian cells has not been done. To quantify such DNA adducts, we generated a novel monoclonal antibody (4OHEN-1) specific for 4-OHEN-DNA adducts. The primary epitope recognized is one type of stereoisomers of 4-OHEN-dA adducts and of 4-OHEN-dC adducts in DNA. An immunoassay with 4OHEN-1 revealed a linear dose-response between known amounts of 4-OHEN-DNA adducts and the antibody binding to those adducts, with a detection limit of approximately five adducts/10(8) bases in 1 microg DNA sample. In human breast cancer cells, the quantitative immunoassay revealed that 4-OHEN produces five times more 4-OHEN-DNA adducts than does 4-OHEQ. Moreover, in a mouse model for HRT, oral administration of Premarin increased the levels of 4-OHEN-DNA adducts in various tissues, including the uterus and ovaries, in a time-dependent manner. Thus, we succeeded in establishing a novel immunoassay for quantitative detection of 4-OHEN-DNA adducts in mammalian cells.


Assuntos
Anticorpos Monoclonais/imunologia , Adutos de DNA/imunologia , Ensaio de Imunoadsorção Enzimática , Envelhecimento , Animais , Especificidade de Anticorpos , Linhagem Celular Tumoral , Adutos de DNA/análise , Adutos de DNA/química , Equilenina/análogos & derivados , Equilenina/química , Equilenina/metabolismo , Equilina/análogos & derivados , Equilina/química , Equilina/metabolismo , Estrogênios Conjugados (USP)/administração & dosagem , Feminino , Humanos , Camundongos , Camundongos Endogâmicos BALB C
3.
J Bacteriol ; 193(19): 5147-54, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21804005

RESUMO

The production of water-insoluble glucan (WIG) enables Streptococcus mutans to survive and persist in the oral niche. WIG is produced from sucrose by glucosyltransferase encoded tandemly by the highly homologous gtfB and gtfC genes. Conversely, a single hybrid gene from the endogenous recombination of gtfB and gtfC is easily generated using RecA, resulting in S. mutans UA159 WIG- (rate of ∼1.0×10(-3)). The pneumococcus recA gene is regulated as a late competence gene. comX gene mutations did not lead to the appearance of WIG- cells. The biofilm collected from the flow cell had more WIG- cells than among the planktonic cells. Among the planktonic cells, WIG- cells appeared after 16 h and increased ∼10-fold after 32 h of cultivation, suggesting an increase in planktonic WIG- cells after longer culture. The strain may be derived from the biofilm environment. In coculture with donor WIG+ and recipient WIG- cells, the recipient cells reverted to WIG+ and acquired an intact gtfBC region from the environment, indicating that the uptake of extracellular DNA resulted in the phenotypic change. Here we demonstrate that endogenous DNA rearrangement and uptake of extracellular DNA generate WIG- cells and that both are induced by the same signal transducer, the com system. Our findings may help in understanding how S. mutans can adapt to the oral environment and may explain the evolution of S. mutans.


Assuntos
Biofilmes/crescimento & desenvolvimento , DNA Bacteriano/metabolismo , Streptococcus mutans/crescimento & desenvolvimento , Streptococcus mutans/metabolismo , Bacteriocinas/metabolismo , Regulação Bacteriana da Expressão Gênica/genética , Regulação Bacteriana da Expressão Gênica/fisiologia , Reação em Cadeia da Polimerase , Streptococcus mutans/genética
4.
Int J Cancer ; 128(4): 974-82, 2011 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-20824696

RESUMO

Treatment with tamoxifen (TAM) increases the risk of developing endometrial cancer in women. The carcinogenic effect is thought to involve initiation and/or promotion resulting from DNA damage induced by TAM as well as its estrogenic action. To minimize this serious side-effect while increasing the anti-breast cancer potential, a new benzopyran antiestrogen, 2E-3-{4-[(7-hydroxy-2-oxo-3-phenyl-2H-chromen-4-yl)-methyl]-phenyl}-acrylic acid (SS5020), was synthesized. Unlike TAM, SS5020 exhibits no genotoxic activity to damage DNA. Furthermore, SS5020 does not present significant uterotrophic potential in rats; in contrast, the structurally related compounds, TAM, toremifene, raloxifene (RAL) and SP500263 all have uterotrophic activity. At the human equivalent molar dose of TAM (0.33 or 1.0 mg/kg), SS5020 had much stronger antitumor potential than those same antiestrogens against 7,12-dimethylbenz(a)anthracene-induced mammary carcinoma in rats. The growth of human MCF-7 breast cancer xenograft implanted into athymic nude mice was also effectively suppressed by SS5020. SS5020, lacking genotoxic and estrogenic actions, could be a safer and stronger antiestrogen alternative to TAM and RAL for breast cancer therapy and prevention.


Assuntos
Cinamatos/uso terapêutico , Moduladores de Receptor Estrogênico/uso terapêutico , Neoplasias Mamárias Experimentais/prevenção & controle , Umbeliferonas/uso terapêutico , 9,10-Dimetil-1,2-benzantraceno/toxicidade , Animais , Carcinógenos/toxicidade , Cinamatos/síntese química , Cinamatos/química , Adutos de DNA , Moduladores de Receptor Estrogênico/síntese química , Moduladores de Receptor Estrogênico/química , Feminino , Humanos , Neoplasias Mamárias Experimentais/induzido quimicamente , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Células Neoplásicas Circulantes , Ratos , Ratos Sprague-Dawley , Tamoxifeno/uso terapêutico , Umbeliferonas/síntese química , Umbeliferonas/química
5.
Int J Cancer ; 127(5): 1021-7, 2010 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-20039324

RESUMO

Ingestion of aristolochic acids (AA) contained in herbal remedies results in aristolochic acid nephropathy (AAN), which is characterized by chronic renal failure, tubulointerstitial fibrosis and urothelial cancer. AA I and AA II, primary components in AA, have similar genotoxic potential, whereas only AA I shows severe renal toxicity in rodents. AA I is demethylated to form 8-hydroxy-aristolochic acid I (AA Ia) as a major metabolite. However, the nephrotoxicity and genotoxicity of AA Ia has not yet been determined. AA Ia was isolated from urine collected from rats treated with AA I and characterized by NMR and mass spectrometry. The purified AA Ia was administered intraperitoneally to C3H/He male mice for 9 days and its toxicity was compared with AA I. Using (32)P-postlabeling/polyacrylamide gel electrophoresis, the level of AA Ia-derived DNA adducts in renal cortex was approximately 70-110 times lower than that observed with AA I, indicating that AA Ia has only a limited genotoxicity. Supporting this result, when calf thymus DNA was reacted with AA Ia in a buffer containing zinc dust, the formation of AA Ia-DNA adducts was two-orders of magnitude lower than that of AA I. Histopathologic analysis revealed that unlike AA I, no significant changes were detected in the renal cortex of mice treated with AA Ia. Therefore, the contribution of AA Ia to renal toxicity is minimum. We conclude the metabolic pathway of converting AA I to AA Ia functions as the detoxification of AA I.


Assuntos
Ácidos Aristolóquicos/toxicidade , Ácidos Aristolóquicos/urina , Carcinógenos/toxicidade , Adutos de DNA/genética , Nefropatias/induzido quimicamente , Metilação , Animais , Ácidos Aristolóquicos/isolamento & purificação , Cromatografia Líquida de Alta Pressão , DNA/genética , Inativação Metabólica , Nefropatias/patologia , Masculino , Camundongos , Camundongos Endogâmicos C3H , Ratos , Ratos Wistar
6.
Int J Cancer ; 127(7): 1718-26, 2010 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-20073065

RESUMO

Long-term treatment with tamoxifen (TAM) increases the risk of developing endometrial cancer in women. Several antiestrogens developed in last decades have been discontinued from clinical testing because of their undesirable effects on the uterus. To avoid such serious side-effect while increasing the drug's anti-breast cancer potential, new triphenylethylene antiestrogens, 2E-3-{4-[(E)-4-chloro-1-(4-hydroxyphenyl)-2-phenylbut-1-enyl]-phenyl} acrylic acid (SS1020) and 2E-3-{4-[(Z)-4-chloro-1,2-diphenylbut-1-enyl]phenyl}acrylic acid (SS1010), were designed as safer alternatives. Unlike TAM, SS1020 does not present significant uterotrophic potential in rats; in contrast, SS1010, a compound removing a 4-OH moiety from SS1020, represented weak uterotrophic activity. The structurally related compounds 4-hydroxytamoxifen, toremifene, ospemifene, raloxifene (RAL) and GW5638 all have uterotrophic activity. In addition, SS1020 and SS1010 exhibit no genotoxic activity to damage hepatic DNA in rats. Therefore, SS1020 was selected as a safer antiestrogen candidate and used for evaluating the antitumor potential in animals. At the human equivalent doses of TAM, SS1020 had antitumor potential much higher than that of TAM, RAL and GW5638 against 7,12-dimethylbenz(a)anthracene-induced mammary carcinoma in rats. The growth of human MCF-7 breast cancer xenograft implanted into athymic nude mice was also effectively suppressed by SS1020. SS1020, lacking estrogenic and genotoxic actions and having strong antitumor potency superior to that of TAM and RAL, could be a safer alternative for breast cancer therapy and prevention.


Assuntos
Neoplasias do Endométrio/prevenção & controle , Antagonistas de Estrogênios/uso terapêutico , Moduladores de Receptor Estrogênico/uso terapêutico , 9,10-Dimetil-1,2-benzantraceno , Animais , Adutos de DNA/farmacologia , Antagonistas de Estrogênios/farmacologia , Moduladores de Receptor Estrogênico/síntese química , Feminino , Humanos , Neoplasias Mamárias Experimentais/induzido quimicamente , Neoplasias Mamárias Experimentais/prevenção & controle , Camundongos , Ratos , Tamoxifeno/análogos & derivados , Tamoxifeno/uso terapêutico , Útero/efeitos dos fármacos , Útero/fisiologia
7.
Case Rep Gastroenterol ; 14(1): 63-69, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32110202

RESUMO

Lenvatinib is a first-line standard treatment for advanced hepatocellular carcinoma (HCC) with better anti-tumor effects than sorafenib, as shown by greater inhibition of the kinases of fibroblast growth factor receptor and vascular endothelial growth factor (VEGF) receptor. This report describes a patient with advanced HCC who experienced perforation of the small intestine 1 month after starting the treatment with lenvatinib. This patient likely had partial necrosis of a metastasis to the small intestine before starting lenvatinib treatment, with subsequent ischemic changes leading to perforation of the small intestine. Although metastasis of HCC to the small intestine is rare, patients with these metastases should be regarded as being at risk for perforation during lenvatinib treatment.

8.
Biochemistry ; 47(25): 6695-701, 2008 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-18512958

RESUMO

Treatment with estrogen increases the risk of breast, ovary, and endometrial cancers in women. DNA damage induced by estrogen is thought to be involved in estrogen carcinogenesis. In fact, Y-family human DNA polymerases (pol) eta and kappa, which are highly expressed in the reproductive organs, miscode model estrogen-derived DNA adducts during DNA synthesis. Since the estrogen-DNA adducts are a mixture of 6alpha- and 6beta-diastereoisomers of dG-N(2)-6-estrogen or dA-N(6)-6-estrogen, the stereochemistry of each isomeric adduct on translesion synthesis catalyzed by DNA pols has not been investigated. We have recently established a phosphoramidite chemical procedure to insert 6alpha- or 6beta-isomeric N(2)-(estradiol-6-yl)-2'-deoxyguanosine (dG-N(2)-6-E(2)) into oligodeoxynucleotides. Using such site-specific modified oligomer as a template, the specificity and frequency of miscoding by dG-N(2)-6alpha-E(2) or dG-N(2)-6beta-E(2) were explored using pol eta and a truncated form of pol kappa (pol kappaDeltaC). Translesion synthesis catalyzed by pol eta bypassed both the 6alpha- and 6beta-isomers of dG-N(2)-6-E(2), with a weak blockage at the adduct site, while translesion synthesis catalyzed by pol kappaDeltaC readily bypassed both isomeric adducts. Quantitative analysis of base substitutions and deletions occurring at the adduct site showed that pol kappaDeltaC was more efficient than pol eta by incorporating dCMP opposite both 6alpha- and 6beta-isomeric dG-N(2)-6-E(2) adducts. The miscoding events occurred more frequently with pol eta, but not with pol kappaDeltaC. Pol eta promoted incorporation of dAMP and dTMP at both the 6alpha- and 6beta-isomeric adducts, generating G --> T transversions and G --> A transitions. One- and two-base deletions were also formed. The 6alpha-isomeric adduct promoted slightly lower frequency of dCMP incorporation and higher frequency of dTMP incorporation and one-base deletions, compared with the 6beta-isomeric adduct. These observations were supported by steady-state kinetic studies. Taken together, the miscoding property of the 6alpha-isomeric dG-N(2)-6-E(2) is likely to be similar to that of the 6beta-isomeric adduct.


Assuntos
Adutos de DNA/metabolismo , DNA Polimerase Dirigida por DNA/metabolismo , Estradiol/análogos & derivados , Guanosina/análogos & derivados , Monofosfato de Adenosina/química , Monofosfato de Adenosina/metabolismo , Sequência de Bases , Catálise , Monofosfato de Citidina/química , Monofosfato de Citidina/metabolismo , Adutos de DNA/química , Adutos de DNA/genética , DNA Polimerase Dirigida por DNA/genética , Eletroforese em Gel de Poliacrilamida , Estradiol/química , Estradiol/metabolismo , Guanosina/química , Guanosina/metabolismo , Humanos , Cinética , Estrutura Molecular , Mutação , Nucleotídeos/química , Nucleotídeos/metabolismo , Oligodesoxirribonucleotídeos/química , Oligodesoxirribonucleotídeos/genética , Oligodesoxirribonucleotídeos/metabolismo , Deleção de Sequência , Estereoisomerismo , Especificidade por Substrato , Timidina Monofosfato/química , Timidina Monofosfato/metabolismo
9.
Int J Cancer ; 122(9): 2142-7, 2008 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-18183587

RESUMO

Raloxifene (RAL) significantly reduced the incidence of breast cancer in women at high risk of developing the disease. Unlike tamoxifen (TAM), an increased incidence of endometrial cancer was not observed in women treated with RAL. However, RAL, having two hydroxyl moieties, can be conjugated rapidly through phase II metabolism and excreted, making it difficult to achieve adequate bioavailability by oral administration in humans. As a result, higher doses must be administered to obtain an efficacy equivalent to that achieved with TAM. To improve oral bioavailability and antitumor potential, RAL diphosphate was prepared as a prodrug. RAL diphosphate showed several orders of magnitude lower binding potential to both ER alpha and ER beta and weak antiproliferative potency on cultured human MCF-7 and ZR-75-1 breast cancer cells, as compared to RAL. However, RAL diphosphate has a much higher bioavailability than RAL, endowing it with higher antitumor potential than RAL against both 7,12-dimethylbenz(a)anthracene-induced mammary carcinoma in rats and human MCF-7 breast cancer implanted in athymic nude mice. The RAL prodrug may provide greater clinical benefit for breast cancer therapy and prevention.


Assuntos
Antineoplásicos Hormonais/farmacologia , Neoplasias da Mama/tratamento farmacológico , Moduladores de Receptor Estrogênico/farmacologia , Neoplasias Mamárias Experimentais/tratamento farmacológico , Organofosfatos/farmacologia , Pró-Fármacos , Cloridrato de Raloxifeno/análogos & derivados , Cloridrato de Raloxifeno/farmacologia , 9,10-Dimetil-1,2-benzantraceno , Administração Oral , Animais , Antineoplásicos Hormonais/sangue , Disponibilidade Biológica , Carcinógenos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Moduladores de Receptor Estrogênico/sangue , Feminino , Humanos , Neoplasias Mamárias Experimentais/induzido quimicamente , Camundongos , Camundongos Nus , Fosforilação , Cloridrato de Raloxifeno/sangue , Ratos , Ratos Sprague-Dawley , Moduladores Seletivos de Receptor Estrogênico/farmacologia , Transplante Heterólogo
10.
J Mol Biol ; 371(5): 1151-62, 2007 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-17603077

RESUMO

4-Hydroxyequilenin (4-OHEN)-dC is a major, potentially mutagenic DNA adduct induced by equine estrogens used for hormone replacement therapy. To study the miscoding property of 4-OHEN-dC and the involvement of Y-family human DNA polymerases (pols) eta, kappa and iota in that process, we incorporated 4-OHEN-dC into oligodeoxynucleotides and used them as templates in primer extension reactions catalyzed by pol eta, kappa and iota. Pol eta inserted dAMP opposite 4-OHEN-dC, accompanied by lesser amounts of dCMP and dTMP incorporation and base deletion. Pol kappa promoted base deletions as well as direct incorporation of dAMP and dCMP. Pol iota worked in conjunction with pol kappa, but not with pol eta, at a replication fork stalled by the adduct, resulting in increased dTMP incorporation. Our results provide a direct evidence that Y-family DNA pols can switch with one another during synthesis past the lesion. No direct incorporation of dGMP, the correct base, was observed with Y-family enzymes. The miscoding potency of 4-OHEN-dC may be associated with the development of reproductive cancers observed in women receiving hormone replacement therapy.


Assuntos
DNA Polimerase Dirigida por DNA/química , Equilenina/química , Equilina/química , Estrogênios/química , Animais , Sequência de Bases , Catálise , Adutos de DNA , Feminino , Terapia de Reposição Hormonal/métodos , Cavalos , Humanos , Cinética , Modelos Químicos , Dados de Sequência Molecular
11.
Chem Res Toxicol ; 21(5): 1120-4, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18447394

RESUMO

Long-term hormone replacement therapy with equine estrogens is associated with a higher risk of breast, ovarian, and endometrial cancers. Reactive oxygen species generated through redox cycling of equine estrogen metabolites may damage cellular DNA. Such oxidative stress may be linked to the development of cancers in reproductive organs. Xeroderma pigmentosa complementation group C-knockout ( Xpc-KO) and wild-type mice were treated with equilenin (EN), and the formation of 7,8-dihydro-8-oxodeoxyguanosine (8-oxodG) was determined as a marker of typical oxidative DNA damage, using liquid chromatography electrospray tandem mass spectrometry. The level of hepatic 8-oxodG in wild-type mice treated with EN (5 or 50 mg/kg/day) was significantly increased by approximately 220% after 1 week, as compared with mice treated with vehicle. In the uterus also, the level of 8-oxodG was significantly increased by more than 150% after 2 weeks. Similar results were observed with Xpc-KO mice, indicating that Xpc does not significantly contribute to the repair of oxidative damage. Oxidative DNA damage generated by equine estrogens may be involved in equine estrogen carcinogenesis.


Assuntos
Dano ao DNA/genética , Proteínas de Ligação a DNA/deficiência , Proteínas de Ligação a DNA/metabolismo , Estrogênios/farmacologia , Cavalos , Animais , Proteínas de Ligação a DNA/genética , Equilenina/análogos & derivados , Equilenina/química , Equilenina/farmacologia , Feminino , Fígado/efeitos dos fármacos , Fígado/metabolismo , Camundongos , Camundongos Knockout , Estrutura Molecular , Oxirredução
12.
Arterioscler Thromb Vasc Biol ; 27(7): 1535-41, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17478760

RESUMO

OBJECTIVES: Acyclic retinoid (ACR) is a synthetic retinoid with a high safety profile that has been pursued with high expectations for therapeutic use in prevention (recurrence) and treatment of malignancies. With the objective of addressing the therapeutic potential in the cardiovasculature, namely neointima formation, effects of ACR on neointima formation and the involved mechanisms were investigated. METHODS AND RESULTS: ACR was administered to cuff-injured mice which showed inhibition of neointima formation. Investigation of involved mechanisms at the cellular and molecular levels showed that ACR induces apoptosis of neointimal cells and this to be mediated by selective induction of retinoic-acid receptor beta (RARbeta) which shows growth inhibitory and proapoptotic effects on smooth muscle cells. CONCLUSION: We show that ACR inhibits neointima formation by inducing RARbeta which in turn inhibits cell growth and induces apoptosis. The retinoid, ACR, may be potentially exploitable for treatment and prevention of neointima formation.


Assuntos
Apoptose/fisiologia , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/crescimento & desenvolvimento , Receptores do Ácido Retinoico , Retinoides/farmacologia , Animais , Apoptose/efeitos dos fármacos , Células Cultivadas , Modelos Animais de Doenças , Artéria Femoral/efeitos dos fármacos , Artéria Femoral/fisiologia , Imuno-Histoquímica , Marcação In Situ das Extremidades Cortadas , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Sensibilidade e Especificidade , Túnica Íntima/efeitos dos fármacos , Túnica Íntima/metabolismo
13.
Microscopy (Oxf) ; 67(5): 280-285, 2018 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-30053169

RESUMO

LiMn1.5Ni0.5O4 is an excellent candidate as a cathode-active material in high-voltage lithium-ion batteries and studied using atomic resolution scanning transmission electron microscope. High-angle annular dark-field (HAADF) images obtained at [100] orientation demonstrate that Mn and Ni atoms are regularly ordered at octahedral sites in a spinel structure, in a 3:1 ratio between columns with high and low intensities. Simulations of HAADF images revealed that atomic columns including Mn exhibit a larger intensity than that by Ni columns, primarily because of the effect of the Debye-Waller factor.

14.
J Vet Med Sci ; 80(12): 1834-1838, 2018 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-30333360

RESUMO

Asian and African elephants are frequently afflicted by foot disorders that can be very challenging to manage even with aggressive therapy. Such conditions may have indirect life-threatening effects. Mohs' paste (zinc chloride based escharotic agent) was used to treat a female Indian elephant (Elephas maximus indicus) aged 39 years with foot disorder at Kanazawa Zoological Gardens. Degenerated hyperplastic tissue was observed inside the hoofs of digits 2 and 5. Mohs' paste was applied on the lesions, which coagulated the hyperplastic tissue and restrained its proliferation. Subsequently, the hyperplastic tissue could be trimmed with little pain, and the disorder became manageable. Mohs' paste treatment was effective and is expected to be an alternative treatment for hoof disorder.


Assuntos
Cloretos/uso terapêutico , Dermatite/veterinária , Elefantes , Doenças do Pé/veterinária , Casco e Garras , Compostos de Zinco/uso terapêutico , Animais , Dermatite/tratamento farmacológico , Dermatite/patologia , Feminino , Doenças do Pé/tratamento farmacológico , Doenças do Pé/patologia , Casco e Garras/patologia
15.
Methods Mol Biol ; 314: 307-21, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16673890

RESUMO

32P-Postlabeling analysis is a powerful technique for detecting, identifying, and quantifying DNA adducts induced by mutagens or carcinogens. The method involves enzymatic digestion of the DNA sample to nucleoside 3'-monophosphates, and partial purification of the adducted nucleotides followed by their 5'-labeling with 32P. For analysis of DNA adducts, polyethyleneimine-cellulose thin-layer chromatography (TLC) plates have traditionally been used to resolve 32P-labeled DNA adducts (32P-postlabeling/ TLC analysis). However, the TLC procedure is time consuming and labor intensive. To expedite analyses, we recently devised a 32P-postlabeling protocol that utilizes nondenaturing polyacrylamide gel electrophoresis (PAGE) and permits multiple DNA samples to be run on a single gel (32P-postlabeling/PAGE analysis). Using this method, the detection limit for 5 microg of DNA is approx 7 adducts/10(9) nucleotides, similar to that for 32P-postlabeling/TLC. For still higher sensitivity and resolution, high-performance liquid chromatography (HPLC) combined with a radioisotope detector system (32P-postlabeling/HPLC analysis) can be used to increase the detection limit to approx 3 adducts/10(10) nucleotides. Here we describe all three 32P-postlabeling techniques.


Assuntos
Cromatografia Líquida de Alta Pressão , Cromatografia em Camada Fina , Adutos de DNA/análise , Dano ao DNA , Eletroforese em Gel de Poliacrilamida , Marcação por Isótopo , Animais , Células Cultivadas , DNA/química , Desoxirribonucleases/química , Humanos , Nucleosídeos/química , Radioisótopos de Fósforo/análise
16.
Cancer Res ; 63(15): 4402-6, 2003 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-12907611

RESUMO

The risk of developing endometrial cancer is increased in breast cancer patients treated with tamoxifen (TAM) and in healthy women undergoing TAM chemoprevention. We have detected previously TAM-DNA adducts in the endometrium of women receiving TAM (Shibutani et al., Carcinogenesis, 21: 1461-1467, 2000). To investigate the genotoxic damage induced by TAM in the uterus and other tissues of primates, we gave adult female cynomolgus monkeys six times the human-equivalent dose of TAM (2 mg/kg body weight/day) for 30 days. DNA samples were prepared from the uterus, ovary, liver, kidney, and brain cortex of three TAM-exposed monkeys and one control monkey and were analyzed as coded specimens. To identify the TAM-DNA adducts, we established a new high-performance liquid chromatography gradient system for (32)P-postlabeling/high-performance liquid chromatography analysis, which can resolve the trans- and cis-diastereoisomers of alpha-(N(2)-deoxyguanosinyl)TAM (dG-N(2)-TAM), alpha-(N(2)-deoxyguanosinyl)-N-desmethylTAM, and alpha-(N(2)-deoxyguanosinyl)tamoxifen N-oxide. Trans-forms of dG-N(2)-TAM and dG-N(2)-N-desTAM adducts were detected in the livers of all three TAM-fed monkeys at levels of 2.7 adducts/10(8) nucleotides and 1.7 adducts/10(8) nucleotides, respectively. The levels of dG-N(2)-TAM adducts observed in the uterus of one monkey and in the ovaries of two monkeys were approximately 10-fold lower than those observed in the livers. TAM exposure also induced dG-N(2)-TAM adduct in the brain cortex of all three monkeys with a value of 1.5 adducts/10(8) nucleotides. No TAM-DNA adducts were detected in the kidneys or in any tissues obtained from the unexposed monkey. Our results suggest that women receiving TAM may form genotoxic damage in many organs, including the reproductive organs.


Assuntos
Adutos de DNA/análise , DNA/metabolismo , Moduladores de Receptor Estrogênico/metabolismo , Moduladores de Receptor Estrogênico/farmacologia , Tamoxifeno/metabolismo , Tamoxifeno/farmacologia , Animais , Córtex Cerebral/metabolismo , Cromatografia Líquida de Alta Pressão/métodos , DNA/efeitos dos fármacos , Adutos de DNA/metabolismo , Feminino , Fígado/metabolismo , Macaca fascicularis , Ovário/metabolismo , Radioisótopos de Fósforo , Útero/metabolismo
17.
J Mol Biol ; 344(3): 665-74, 2004 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-15533436

RESUMO

Cellular DNA is damaged by nitric oxide (NO), a multifunctional bioregulator and an environmental pollutant that has been implicated in diseases associated with cancer and chronic inflammation. 2'-Deoxyxanthosine (dX) is a major NO-derived DNA lesion. To explore the mutagenic potential of dX, a 38-mer oligodeoxynucleotide ((5')CATGCTGATGAATTCCTTCXCTTCTTTCCTCTCCCTTT) modified site-specifically with dX at the X position was prepared post-synthetically and used as a DNA template in primer extension reactions catalyzed by calf thymus DNA polymerase (pol) alpha and human DNA pol beta, eta, and kappa. Primer extension reactions catalyzed by pol alpha or beta in the presence of four dNTPs were retarded at the dX lesion while pol eta and kappa readily bypassed the lesion. The fully extended products were analyzed to quantify the miscoding specificity and frequency of dX using two-phase polyacrylamide gel electrophoresis (PAGE). With pol alpha, eta and kappa, incorrect dTMP was preferentially incorporated opposite the lesion, along with lesser amounts of dCMP, the correct base. When pol beta was used, direct incorporation of correct dCMP was primarily observed, accompanied by small amounts of misincorporation of dTMP, dAMP and dGMP. Steady-state kinetic analyses supported the results obtained from the two-phase PAGE assay. dX is a miscoding lesion capable of preferentially generating G-->A mutations. The miscoding frequency varied depending on DNA polymerase used.


Assuntos
Adutos de DNA , Reparo do DNA , DNA Polimerase Dirigida por DNA/metabolismo , Desoxirribonucleosídeos/química , Óxido Nítrico/química , Animais , Sequência de Bases , Cromatografia Líquida de Alta Pressão , Cinética , Oligodesoxirribonucleotídeos , Moldes Genéticos
18.
Chem Biol Interact ; 152(2-3): 131-8, 2005 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-15840386

RESUMO

2-Acetylaminonaphthalene (2-AAN) has been recognized as a urinary bladder carcinogen in humans. The deacetylated form, 2-aminonaphthalene (2-AN), is metabolized in vivo and reacts primarily with guanine residues in DNA, resulting in the formation of dG-N(2)-aminonaphthalene (dG-N(2)-AN) adduct. Phosphoramidite chemical procedure has recently been established in our laboratory to prepare oligodeoxynucleotides containing a single dG-N(2)-acetylaminonaphthalene (dG-N(2)-AAN) adduct. Oligodeoxynucleotides ((5')TCCTCCTNXCCTCTC, where X is dG or dG-N(2)-AAN and N is C, A, T or G) with different bases 5' flanking to the lesion were prepared and were inserted into a single-strand shuttle vectors and used to establish the mutational frequency and specificity of dG-N(2)-AAN adduct in simian kidney cells. dG-N(2)-AAN adduct promoted preferential incorporation of dCMP, the correct base, opposite the lesion. When the 5' flanking base to the lesion was C, A or T, the mutational frequency was under 2.1%. When G flanked to the lesion, the mutational frequency was slightly increased to 4.2%. Misincorporation of dAMP, dTMP, and/or dGMP varied depending on the 5' flanking base. When dG-N(2)-AAN was positioned at codon 61 of noncoding strand of human c-Ha-ras1 gene ((5')TCCTCCTXGCCTCTC, where X is dG-N(2)-AAN), the mutational frequency was 6.7%; G-->T transversions (4.7%), followed by G-->A transition (2.0%), were observed. These results demonstrated that dG-N(2)-AAN is a weak mutagenic lesion in mammalian cells. The influence of 5' flanking sequence context was observed on the mutational frequency and specificity of this adduct.


Assuntos
2-Naftilamina/análogos & derivados , 2-Naftilamina/toxicidade , Carcinógenos/toxicidade , Adutos de DNA/metabolismo , 2-Naftilamina/metabolismo , Animais , Sequência de Bases , Células COS , Carcinógenos/metabolismo , Chlorocebus aethiops , Adutos de DNA/genética , Desoxiguanosina/genética , Desoxiguanosina/metabolismo , Vetores Genéticos , Humanos , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Oligodesoxirribonucleotídeos/síntese química , Oligodesoxirribonucleotídeos/metabolismo
19.
Respir Investig ; 51(3): 147-52, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23978640

RESUMO

BACKGROUND: A single nucleotide polymorphism (SNP; rs20541) in the IL-13 gene has been recognized as a risk factor for asthma. This SNP causes Arg to Gln (Q) substitution at position 110 in the mature IL-13 protein. We have recently showed that FEV1 in asthmatics with the Q110 variant of IL-13 declined faster, and progressive airway remodeling was observed in these subjects (Wynn, 2003 [1]). However, the effects of the IL-13 variant on airway hyperresponsiveness (AHR) remain to be elucidated. We analyzed the relationship between SNP rs20541 in IL-13 and AHR in asthmatics. METHODS: We recruited 182 asthmatics who visited the asthma outpatient clinic at Iwate Medical University Hospital from 2006 to 2011. Subjects were genotyped for rs20541. Asthma severity, atopic status, age of asthma onset, serum IgE concentration, AHR, and pulmonary function were studied in these subjects. AHR was measured using the continuous methacholine inhalation method (Astograph; Chest; Tokyo, Japan). RESULTS: Genotyping of rs20541 revealed 26 A/A, 77 A/G, and 79 G/G patient genotypes. The D min (U) of the 3 genotypes was 1.17±0.300 in A/A, 1.99±0.35 in A/G, and 2.85±0.39 in G/G. The D min in the 3 genotypes was significantly different. Spirometric data revealed that % FEV1 and % FEF75 were significantly different among the 3 groups of IL-13 genotypes, whereas no significant differences were observed in therapeutic steps, atopic status, house dust mite sensitization, or serum IgE concentration. CONCLUSION: The SNP rs20541 in IL-13 was associated with AHR in Japanese adult asthmatics.


Assuntos
Asma/genética , Hiper-Reatividade Brônquica/genética , Interleucina-13/genética , Polimorfismo de Nucleotídeo Único/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Remodelação das Vias Aéreas/genética , Substituição de Aminoácidos/genética , Povo Asiático , Hiper-Reatividade Brônquica/diagnóstico , Feminino , Genótipo , Humanos , Interleucina-13/química , Masculino , Pessoa de Meia-Idade , Testes de Função Respiratória , Fatores de Risco , Adulto Jovem
20.
Int J Rheum Dis ; 16(4): 455-62, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23992268

RESUMO

OBJECTIVES: Imatinib mesylate (IM) is a potent and specific tyrosine inhibitor and has been reported to inhibit mesenchymal cell proliferation in pulmonary fibrosis. In the present study, we examine the effects of IM on vascular remodeling in a murine model of allergic vasculitis with eosinophil infiltration. METHODS: C57BL/6 mice were sensitized with ovalbumin (OVA) and alum. The positive controls were exposed to aerosolized OVA daily for 7 days. IM treated mice with exposure to OVA were administered IM in parallel with daily exposure to aerosolized OVA for 7 days. On the 7th day, bronchoalveolar lavage (BAL) was performed and the lungs were excised for pathological analysis. Cell differentials were determined and the concentrations of cytokines in the BAL fluid (BALF) were measured. Semi-quantitative analysis of pathological changes in the pulmonary arteries was evaluated according to the criteria of severity of vasculitis. Immunohistochemistry for Ki-67 to detect proliferating cells was performed. RESULTS: The number of eosinophils in BALF was reduced significantly in the IM-treated group compared to the positive control. There was no significant difference in the concentrations of interleukin (IL)-2, IL-4, IL-5, interferon (IFN)-γ, tumor necrosis factor (TNF)-α, tumor growth factor (TGF)-ß or platelet-derived growth factor in the BAL fluid between the positive control and the IM-treated group. The pathological scores of vasculitis and the ratio of Ki-67-positive intra-luminal cells were reduced significantly in the IM-treated group compared to the control group after OVA exposure. CONCLUSION: IM-suppressed pulmonary vascular remodeling in a murine model of allergic vasculitis with eosinophil infiltration.


Assuntos
Benzamidas/uso terapêutico , Piperazinas/uso terapêutico , Inibidores de Proteínas Quinases/uso terapêutico , Pirimidinas/uso terapêutico , Hipersensibilidade Respiratória/tratamento farmacológico , Hipersensibilidade Respiratória/epidemiologia , Vasculite/tratamento farmacológico , Vasculite/epidemiologia , Administração por Inalação , Administração Oral , Animais , Benzamidas/administração & dosagem , Benzamidas/farmacologia , Líquido da Lavagem Broncoalveolar , Proliferação de Células/efeitos dos fármacos , Comorbidade , Citocinas/metabolismo , Modelos Animais de Doenças , Eosinófilos/patologia , Feminino , Mesilato de Imatinib , Camundongos , Camundongos Endogâmicos C57BL , Miofibroblastos/patologia , Ovalbumina/administração & dosagem , Ovalbumina/efeitos adversos , Piperazinas/administração & dosagem , Piperazinas/farmacologia , Inibidores de Proteínas Quinases/administração & dosagem , Inibidores de Proteínas Quinases/farmacologia , Pirimidinas/administração & dosagem , Pirimidinas/farmacologia , Hipersensibilidade Respiratória/induzido quimicamente , Vasculite/metabolismo
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