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1.
Clin Exp Allergy ; 44(11): 1347-60, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25255717

RESUMO

BACKGROUND: Infiltration of fibrocytes (FC) in the airway smooth muscle is a feature of asthma, but the pathological significance is unknown. OBJECTIVE: We sought to explore whether FC modulate the phenotype of airway smooth muscle cells (ASMC) in asthmatic vs. control subjects. METHODS: Fibrocytes were isolated from CD14+ monocytes from asthmatic and normal subjects. Proliferation of ASMC of asthmatic or normal subjects was analysed by (3) H-thymidine incorporation, cell number counting and Ki-67 expression after treatment of ASMC with FC-conditioned medium (FCCM) or co-culture with FC. ASMC-associated cytokines/chemokines implicated in asthma (TGF-ß1, eotaxin, IL-6 and IL-8) were measured in co-culture or transwell culture of ASMC + FC by ELISA. Immunofluorescence staining was performed to localize these cytokines in ASMC. Cytokine secretion was measured in the transwell culture of ASMC + FC, where NF-κB-p65 or ERK1/2 in ASMC was silenced by siRNA. Contractile phenotype of ASMC in transwell culture was assessed by immunoblotting of α-smooth muscle actin (α-SMA) and myosin light chain kinase (MLCK). RESULTS: Fibrocytes did not affect ASMC proliferation and expression of TGF-ß1, eotaxin, α-SMA and MLCK; however, ASMC production of IL-8 and IL-6 was increased in the co-culture and transwell culture by FC. ASMC treated with FCCM were immunopositive for IL-8/IL-6 and produced more IL-8/IL-6. Furthermore, siRNA silencing of NF-κB-p65 or ERK1/2 in transwell cultures of asthmatic ASMC with normal subject FC decreased IL-8 and IL-6 production. CONCLUSIONS AND CLINICAL RELEVANCE: Fibrocytes promoted IL-8 and IL-6 production by ASMC, demonstrating a proinflammatory role for FC and a possible mechanism of the inflammatory phenotype in asthma.


Assuntos
Asma/metabolismo , Asma/patologia , Monócitos/metabolismo , Miócitos de Músculo Liso/metabolismo , Fenótipo , Actinas/metabolismo , Adulto , Asma/diagnóstico , Asma/imunologia , Estudos de Casos e Controles , Comunicação Celular , Diferenciação Celular , Células Cultivadas , Técnicas de Cocultura , Colágeno Tipo I/metabolismo , Feminino , Humanos , Interleucina-6/biossíntese , Interleucina-8/biossíntese , Masculino , Pessoa de Meia-Idade , Monócitos/citologia , Quinase de Cadeia Leve de Miosina/metabolismo , Transdução de Sinais
2.
Acta Crystallogr Sect E Struct Rep Online ; 70(Pt 2): o106, 2014 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-24764838

RESUMO

In the title compound, C22H15N3O, the dihedral angle between the two indole units is 33.72 (3)°. The mol-ecular structure features a weak intra-molecular C-H⋯N inter-action. In the crystal, weak C-H⋯O and C-H⋯π inter-actions, forming a two-dimensional network parallel to the bc plane.

3.
Acta Crystallogr Sect E Struct Rep Online ; 70(Pt 2): o197, 2014 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-24764907

RESUMO

In the title compound C20H13N5, the dihedral angle between the carbazole ring system (r.m.s. deviation = 0.027 Å) and the pendant benzene ring is 55.08 (6)°. One of the azide N atoms is disordered over two positions in a 0.65 (2):0.35 (2) ratio. In the crystal, aromatic π-π stacking is observed [minimum centroid-centroid separation = 3.6499 (13) Å] as well as inversion-dimers connected by pairs of weak C-H⋯π inter-actions.

4.
Ann Oncol ; 22(1): 68-73, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20647220

RESUMO

BACKGROUND: although trastuzumab has improved the prognosis for HER-2-positive breast cancer patients, not all HER-2-positive breast tumours respond to trastuzumab treatment and those that initially respond frequently develop resistance. Insulin-like growth factor-1 receptor (IGF1R) signalling has been previously implicated in trastuzumab resistance. We tested IGF1R inhibition to determine if dual targeting of HER-2 and IGF1R improves response in cell line models of acquired trastuzumab resistance. MATERIALS AND METHODS: HER-2, IGF1R, phospho-HER-2, and phospho-IGF1R levels were measured by enzyme-linked immunosorbent assays in parental and trastuzumab-resistant SKBR3 and BT474 cells. IGF1R signalling was targeted in these cells using both small interfering RNA (siRNA) and the tyrosine kinase inhibitor, NVP-AEW541. RESULTS: IGF1R levels were significantly increased in the trastuzumab-resistant model, SKBR3/Tr, compared with the parental SKBR3 cell line. In both the SKBR3/Tr and BT474/Tr cell lines, inhibition of IGF1R expression with siRNA or inhibition of tyrosine kinase activity by NVP-AEW541 significantly increased response to trastuzumab. The dual targeting approach also improved response in the parental SKBR3 cells but not in the BT474 parental cells. CONCLUSIONS: our results confirm that IGF1R inhibition improves response to trastuzumab in HER-2-positive breast cancer cells and suggest that dual targeting of IGF1R and HER-2 may improve response in HER-2-positive tumours.


Assuntos
Anticorpos Monoclonais/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias da Mama/terapia , Receptor ErbB-2/antagonistas & inibidores , Receptor IGF Tipo 1/antagonistas & inibidores , Anticorpos Monoclonais/administração & dosagem , Anticorpos Monoclonais Humanizados , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/enzimologia , Neoplasias da Mama/genética , Processos de Crescimento Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Terapia Combinada , Resistencia a Medicamentos Antineoplásicos , Sinergismo Farmacológico , Feminino , Humanos , Inibidores de Proteínas Quinases/administração & dosagem , Pirimidinas/administração & dosagem , Pirróis/administração & dosagem , RNA Interferente Pequeno/administração & dosagem , RNA Interferente Pequeno/genética , Receptor ErbB-2/biossíntese , Receptor ErbB-2/genética , Receptor ErbB-2/metabolismo , Receptor IGF Tipo 1/genética , Receptor IGF Tipo 1/metabolismo , Transfecção , Trastuzumab
5.
Acta Crystallogr Sect E Struct Rep Online ; 67(Pt 10): o2796, 2011 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-22058824

RESUMO

In the title compound, C(20)H(14)N(2), the carbazole ring system is essentially planar (r.m.s. deviation = 0.187 Å) and is inclined at an angle of 54.33 (4) ° with respect to the benzene ring. The crystal packing is stabilized by weak C-H⋯N and C-H⋯π inter-actions.

6.
Public Health Action ; 11(3): 146-154, 2021 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-34567991

RESUMO

BACKGROUND: WHO drug-resistant TB (DR-TB) treatment recommendations now emphasize all-oral regimens, recommending against certain injectable agents and deprioritizing others due to inferior safety and efficacy. Despite increasing focus on patient-centered care, we are not aware of systematic attempts to qualitatively document patients' perspectives on injectable agents. This may inform implementation of WHO guidelines, emphasizing the importance of consultation with affected communities. METHODS: Testimonies were provided by TB survivors who experienced hearing loss from treatment with injectable agents. Testimonies were submitted in writing in response to minimal, standardized, open-ended prompts. Participants provided a signed consent form (with options to participate anonymously or as a named co-author), and later gave input into the overall shape and recommendations of the article. RESULTS: Fourteen TB survivors in 12 countries contributed testimonies. The following common themes emerged: lack of access to appropriate testing, information, treatment, or a collaborative treatment environment; the power of supportive care and social environments; stigma and isolation from TB treatment itself and resultant disability; and inaccessibility of cochlear implants. CONCLUSIONS: Survivor testimonies indicate strong preferences for avoidance of injectable agents, supporting rapid implementation of revised WHO guidelines, as well as for quality and supportive care for both TB and disabilities.


CONTEXTE: Les recommandations de l'OMS pour le traitement de la TB pharmacorésistante (DR-TB) mettent désormais l'accent sur les schémas thérapeutiques entièrement par voie orale, préconisant de ne pas utiliser certains agents injectables et de ne plus donner la priorité à d'autres en raison d'une innocuité et d'une efficacité inférieures. Malgré l'attention accrue portée aux soins centrés sur le patient, nous ne connaissons aucune étude systématique ayant cherché à documenter de manière qualitative le point de vue des patients sur les agents injectables. Ce travail pourrait guider la mise en place des directives de l'OMS, en mettant l'accent sur l'importance de consulter les communautés concernées. MÉTHODES: Des personnes ayant survécu à une TB et ayant connu une perte d'audition due à un traitement par agents injectables ont apporté leurs témoignages. Les témoignages ont été soumis par écrit en réponse à des questions courtes, ouvertes et standardisées. Les participants ont signé un formulaire de consentement (avec possibilité de participer de manière anonyme ou en tant que coauteur nommé) et ont ensuite contribué au format général et aux recommandations de l'article. RÉSULTATS: Quatorze personnes ayant survécu à une TB provenant de 12 pays ont apporté leur témoignage. Les thématiques suivantes ont été fréquemment mentionnées : manque d'accès aux tests, informations et traitements appropriés ou à un environnement thérapeutique collaboratif ; importance des soins de soutien et de l'environnement social ; stigmatisation et isolement dus au traitement antituberculeux et handicaps qui en résultent ; et inaccessibilité aux implants cochléaires. CONCLUSIONS: Le témoignage des personnes ayant survécu à une TB indique qu'elles préfèrent nettement éviter les agents injectables, allant ainsi dans le sens d'une mise en place rapide des directives révisées de l'OMS, et qu'elles préfèrent des soins de qualité et de soutien pour la TB mais aussi pour les handicaps qui en résultent.

7.
Oncogene ; 37(4): 461-477, 2018 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-28967906

RESUMO

Recently, we reported that the histone methyltransferase, EZH2, controls leukocyte migration through interaction with the cytoskeleton remodeling effector, VAV, and direct methylation of the cytoskeletal regulatory protein, Talin. However, it is unclear whether this extranuclear, epigenetic-independent function of EZH2 has a profound impact on the initiation of cellular transformation and metastasis. Here, we show that EZH2 increases Talin1 methylation and cleavage, thereby enhancing adhesion turnover and promoting accelerated tumorigenesis. This transforming capacity is abolished by targeted disruption of EZH2 interaction with VAV. Furthermore, our studies demonstrate that EZH2 in the cytoplasm is closely associated with cancer stem cell properties, and that overexpression of EZH2, a mutant EZH2 lacking its nuclear localization signal (EZH2ΔNLS), or a methyl-mimicking Talin1 mutant substantially promotes JAK2-dependent STAT3 activation and cellular transformation. Taken together, our results suggest a critical role for the VAV interaction-dependent, extranuclear action of EZH2 in neoplastic transformation.


Assuntos
Transformação Celular Neoplásica/genética , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Regulação Neoplásica da Expressão Gênica , Neoplasias/patologia , Proteínas Proto-Oncogênicas c-vav/metabolismo , Animais , Adesão Celular/genética , Linhagem Celular Tumoral , Transformação Celular Neoplásica/patologia , Citoplasma/genética , Citoplasma/patologia , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Proteína Potenciadora do Homólogo 2 de Zeste/isolamento & purificação , Feminino , Técnicas de Silenciamento de Genes , Células HEK293 , Humanos , Janus Quinase 2/genética , Janus Quinase 2/metabolismo , Células Jurkat , Metilação , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos NOD , Camundongos SCID , Mutagênese Sítio-Dirigida , Neoplasias/genética , Sinais de Localização Nuclear/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Fator de Transcrição STAT3/genética , Fator de Transcrição STAT3/metabolismo , Talina/genética , Talina/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
8.
Clin Transl Sci ; 10(6): 496-502, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28675684

RESUMO

A translational need exists to understand and predict vancomycin-induced kidney toxicity. We describe: (i) a vancomycin high-performance liquid chromatography (HPLC) method for rat plasma and kidney tissue homogenate; (ii) a rat pharmacokinetic (PK) study to demonstrate utility; and (iii) a catheter retention study to enable future preclinical studies. Rat plasma and pup kidney tissue homogenate were analyzed via HPLC for vancomycin concentrations ranging from 3-75 and 15.1-75.5 µg/mL, respectively, using a Kinetex Biphenyl column and gradient elution of water with 0.1% formic acid: acetonitrile (70:30 v/v). Sprague-Dawley rats (n = 10) receiving 150 mg/kg of vancomycin intraperitoneally had plasma sampled for PK. Finally, a catheter retention study was performed on polyurethane catheters to assess adsorption. Precision was <6.1% for all intra-assay and interassay HPLC measurements, with >96.3% analyte recovery. A two-compartment model fit the data well, facilitating PK exposure estimates. Finally, vancomycin was heterogeneously retained by polyurethane catheters.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Testes de Toxicidade , Vancomicina/farmacocinética , Vancomicina/toxicidade , Animais , Teorema de Bayes , Bioensaio , Cateterismo , Rim/metabolismo , Masculino , Ratos Sprague-Dawley , Extratos de Tecidos , Vancomicina/sangue
9.
J Laryngol Otol ; 131(4): 350-356, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28124628

RESUMO

OBJECTIVES: To validate the ovine model of profound oropharyngeal dysphagia and compare swallowing outcomes of laryngotracheal separation with those of total laryngectomy. METHODS: Under real-time fluoroscopy, swallowing trials were conducted using the head and neck of two Dorper cross ewes and one human cadaver, secured in lateral fluoroscopic orientation. Barium trials were administered at baseline, pre- and post-laryngohyoid suspension, following laryngotracheal separation, and following laryngectomy in the ovine model. RESULTS: Mean pre-intervention Penetration Aspiration Scale and National Institutes of Health Swallow Safety Scale scores were 8 ± 0 and 6 ± 0 respectively in sheep and human cadavers, with 100 per cent intra- and inter-species reproducibility. These scores improved to 1 ± 0 and 2 ± 0 post-laryngohyoid suspension (p < 0.01). Aerodigestive tract residue was 18.6 ± 2.4 ml at baseline, 15.4 ± 3.8 ml after laryngotracheal separation and 3.0 ± 0.7 ml after total laryngectomy (p < 0.001). CONCLUSION: The ovine model displayed perfect intra- and inter- species reliability for the Penetration Aspiration Scale and Swallow Safety Scale. Less aerodigestive tract residue after narrow-field laryngectomy suggests that swallowing outcomes after total laryngectomy are superior to those after laryngotracheal separation.


Assuntos
Transtornos de Deglutição/cirurgia , Deglutição/fisiologia , Laringectomia/métodos , Laringoscopia/métodos , Animais , Cadáver , Transtornos de Deglutição/fisiopatologia , Modelos Animais de Doenças , Feminino , Humanos , Laringe/cirurgia , Período Pós-Operatório , Reprodutibilidade dos Testes , Índice de Gravidade de Doença , Ovinos , Traqueia/cirurgia , Resultado do Tratamento
10.
J Control Release ; 111(1-2): 19-26, 2006 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-16377018

RESUMO

The absorption of erythropoietin (EPO) from rat small intestine was studied using gastro-intestinal patches (GI-PS) in the presence of absorption enhancers. Surfactants such as a saturated polyglycolysed C8-C18 glyceride (Gelucire 44/14), PEG-8 capryl/caprylic acid glycerides (Labrasol), and polyoxyethylene hydrogenated castor oil derivative (HCO-60) were used as absorption enhancers at 143, 94 and 20 mg/kg, respectively. The absorption of EPO was studied by measuring serum EPO levels by an ELISA method after small intestinal administration of EPO-GI-PS preparation in rats at the EPO dose level of 100 IU/kg. Labrasol showed the highest absorption enhancing effect after intrajejunum administration with maximum serum EPO level of 84.1+/-11.4 mIU/ml while Gelucire 44/14 and HCO-60 showed 43.5+/-9.8 and 26.5+/-2.3 mIU/ml, respectively. The appropriate site for EPO absorption was also investigated. Jejunum was found to be the most efficient absorption site for the absorption of EPO from GI-PS. Using Labrasol as the absorption enhancer and jejunum as the absorption site, the effect of EPO dose on EPO absorption was studied by increasing the EPO dose from 50, to 100, 300 and 600 IU/kg. It was found that 100 IU/kg was the optimum dose with a serum EPO level of 84.1+/-11.4 mIU/ml while escalating doses showed decreases in serum EPO levels 48.3+/-5.6 for 300 IU/kg and 50.6+/-10.3 mIU/ml for 600 IU/kg. The percent bioavailability (BA) of EPO-GI-PS with Labrasol as absorption enhancer was 7.9 at 50 IU/kg, 12.1 at 100 IU/kg, 3.2 at 300 IU/kg and 1.2 at 600 IU/kg. Histological studies showed no adverse effect at the site of administration.


Assuntos
Portadores de Fármacos/química , Eritropoetina/farmacocinética , Trato Gastrointestinal/metabolismo , Administração Oral , Algoritmos , Animais , Área Sob a Curva , Óleo de Rícino/análogos & derivados , Óleo de Rícino/química , Sistemas de Liberação de Medicamentos , Eritropoetina/administração & dosagem , Eritropoetina/química , Glicerídeos , Absorção Intestinal , Jejuno/metabolismo , Masculino , Taxa de Depuração Metabólica , Compostos Orgânicos/química , Polietilenoglicóis/química , Ratos , Ratos Wistar
11.
Int J Pharm ; 310(1-2): 46-52, 2006 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-16439074

RESUMO

Oral administration of mucoadhesive tablets containing erythropoietin (EPO) and an absorption enhancer Labrasol was studied in rats and dogs. Mucoadhesive tablets were prepared using Sylysia 550 holding the absorption enhancer and Carbopol 974P as a mucoadhesive agent. Mucoadhesive tablets were covered with a water-insoluble backing layer made of cellulose acetate and a pH-sensitive covering layer made of Eudragit L/Eudragit S. Tablet was administered into the rat jejunum at EPO dose of 100 IU/kg and serum samples were collected for 6h. Serum EPO level was analysed with a standard ELISA procedure. After administration, rats showed a maximum serum EPO level of C(max) 70.6 +/- 8.9 mIU/ml. Oral administration of a single tablet containing 100 IU/kg EPO to beagle dogs showed a C(max) of 24.6 +/- 4.1. When EPO dose was increased to 500 IU/kg and the number of tablets was also increased to 5, the C(max) was 54.8 +/- 9.0 mIU/ml. However, when EPO, 100 IU/kg dose was divided into five tablets, the C(max) was 15.5 +/- 1.8 mIU/ml. In the absence of absorption enhancer, the C(max) was 35.8 +/- 3.8 with 500 IU/kg dose distributed among five tablets. Pharmacodynamic studies were carried out following oral administration of mucoadhesive tablets for 6 consecutive days at an EPO dose of 500 IU/kg. Whole blood samples were collected and percent circulating reticulocytes were counted using Miller technique. The increase in percent circulating reticulocytes was found to be 1.7% on day 8 following oral administration. As a control study, EPO was administered by i.v. route at a dose of 300 IU/kg for 3 consecutive days and the percent circulating reticulocytes were counted. Mucoadhesive tablets showed promising results as an oral drug delivery system for protein therapeutics.


Assuntos
Eritropoetina/administração & dosagem , Eritropoetina/farmacocinética , Absorção Intestinal , Acrilatos/química , Adesividade , Administração Oral , Animais , Química Farmacêutica , Cães , Relação Dose-Resposta a Droga , Eritropoetina/química , Glicerídeos , Absorção Intestinal/efeitos dos fármacos , Masculino , Mucosa/química , Compostos Orgânicos/farmacologia , Ratos , Ratos Sprague-Dawley , Contagem de Reticulócitos , Comprimidos com Revestimento Entérico
12.
Cancer Res ; 38(9): 2922-4, 1978 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28178

RESUMO

Cyclophosphamide, an extensively used cancer chemotherapeutic agent, requires metabolic activation through a mixed-function oxygenase system. The capacity of this agent to produce oncogenic transformation and chromosomal damage, including increases in sister chromatid exchanges, was investigated in cell culture with or without an exogenous liver metabolic activation system. No oncogenic transformation or chromosomal aberrations were produced by cyclophosphamide in the absence of metabolic activation, whereas significant transformation, chromosomal breaks, and increases in sister chromatid exchanges were observed when the activation system was incorporated into the assays. The oncogenic transformation and chromosomal changes were completely eliminated by removing glucose 6-phosphate and nicotinamide adenine dinucleotide phosphate from the metabolic generating system. These studies emphasize the necessity to incorporate some activation procedure into short-term assays used for evaluating the mutagenic and/or oncogenic potential of various chemicals.


Assuntos
Transformação Celular Neoplásica , Aberrações Cromossômicas , Troca Genética/efeitos dos fármacos , Ciclofosfamida/farmacologia , Microssomos Hepáticos/metabolismo , Animais , Carcinógenos , Linhagem Celular , Ciclofosfamida/metabolismo , Avaliação Pré-Clínica de Medicamentos/métodos , Glucofosfatos/administração & dosagem , Técnicas In Vitro , Masculino , Mutagênicos , NADP/administração & dosagem , Ratos
14.
Oncogene ; 9(7): 2089-96, 1994 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8208556

RESUMO

Cyclin-dependent, proline-directed protein kinases normally function to execute critical cell cycle transitions; abnormal expression and/or viral subversion of the positive (cyclins) and negative (Pic1) regulatory subunits may contribute to neoplastic transformation and tumorigenesis. In addition to the binding of regulatory subunits, the enzymatic activities of the cyclin-dependent kinases, Cdc2 and Cdk2, are tightly regulated by site-specific protein phosphorylation events. Recent studies have identified a critical phosphorylation site (Thr-161) located within kinase Subdomain VIII that is necessary for Cdc2 activation, and enzymatic activities capable of carrying out this heterologous phosphorylation event have been detected in both Xenopus oocytes and human somatic cells. In this report, we characterize by molecular cloning a human homologue of the Xenopus Cdk-activating kinase (Cak, encoded by MO15); the novel human gene is designated (HS)CAK1. While only 75% identity is observed at the nucleotide level, the deduced amino acid sequence encoded by (HS)CAK1 is approximately 87% identical to that of the Xenopus MO15 gene in corresponding regions. The catalytic domain of (HS)Cak1, defined by conserved kinase Subdomains I through XI, exhibits considerable homology with (HS)Cdc2, suggesting that this kinase cascade involves closely related enzymes. Immunological studies with anti-Cak antibodies confirm the presence of specific immunoreactivity in highly purified preparations of the human Cdc2-activating kinase. The molecular characterization of (HS)CAK1 should facilitate studies of its physiological regulation, as well as its potential utility as a target for therapeutic intervention in the treatment of proliferative disorders.


Assuntos
Proteína Quinase CDC2/genética , Quinases Ciclina-Dependentes , Proteínas Serina-Treonina Quinases/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Proteína Quinase CDC2/metabolismo , Clonagem Molecular , Sondas de DNA , DNA Complementar , Humanos , Dados de Sequência Molecular , Homologia de Sequência de Aminoácidos , Células Tumorais Cultivadas , Quinase Ativadora de Quinase Dependente de Ciclina
15.
Biochim Biophys Acta ; 478(4): 454-60, 1977 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-199257

RESUMO

Regulation of DNA synthesis was investigated in SV40 transformed 3T3 cells exhibiting variable growth rates and residence times in S phase when cultured in the presence of different serum concentrations. Pulse-labeled DNA was chased into large molecular weight material in vivo much more slowly in slowly growing cells than in cells growing at the normal rate. Consistent with this, the joining of short (less than 10 S) chains to form long (greater than 10 S) chains by whole cell lysate system in vitro was greatly impaired in slowly growing cells compared to controls. Thus the lengthening of S phase in SV3T3 cells growing slowly in low serum is reflected in a reduced rate of DNA chain elongation. The presence of cycloheximide during chase in vivo reduced the rate of conversion of pulse-labeled molecules into large molecular weight DNA in both slowly growing and normally growing cells.


Assuntos
Ciclo Celular , DNA/biossíntese , Divisão Celular , Transformação Celular Neoplásica , Células Cultivadas , Técnicas In Vitro , Precursores de Ácido Nucleico/biossíntese , Vírus 40 dos Símios , Fatores de Tempo
16.
Biochim Biophys Acta ; 1407(2): 125-34, 1998 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-9685608

RESUMO

The present study investigated the glycosylation state of proteins in lung tissue of a cyclophosphamide-induced model of pulmonary fibrosis in rats. In fibrotic lung, the carbohydrate constituents (total hexose, fucose, sialic acid and hexosamine) of salt-soluble, collagenase, elastase and papain digested glycoproteins were significantly higher compared to normal lungs. Interestingly, fibrotic lung tissues had higher activities of mannosyl, glucosyl, galactosyl, sialyl and fucosyl transferases than normal lung tissues. Similarly, mannosyl, glucosyl, galactosyl, sialyl and fucosyl transferases were higher in serum from rats with fibrosis than in that from normals. These data indicate that glycoprotein metabolism is significantly altered from normal in animals with interstitial lung fibrosis.


Assuntos
Ciclofosfamida/farmacologia , Glicoproteínas/química , Pulmão/patologia , Animais , Modelos Animais de Doenças , Endopeptidases/metabolismo , Fibrose/induzido quimicamente , Glicosiltransferases/análise , Hidroxiprolina/metabolismo , Pulmão/enzimologia , Masculino , Monossacarídeos/análise , Ratos , Ratos Wistar
17.
Diabetes ; 40(4): 492-8, 1991 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-1849104

RESUMO

The effects of oral vanadyl sulfate administration for 9-12 days on carbohydrate and lipid metabolism in the basal state and on glucose dynamics during submaximal hyperinsulinemic clamps were investigated in nondiabetic and streptozocin-induced diabetic rats. Decreases in growth rate and water and food consumption were the only significant alterations noted in control animals receiving vanadyl. Administration of vanadyl to diabetic rats resulted in weight loss; a significant decrease in plasma glucose, triglyceride, and cholesterol levels; and decreases in food and water intake, without a concomitant change in plasma insulin concentrations. Vanadyl treatment did not modify either peripheral glucose utilization or hepatic glucose production in control rats during submaximal insulin clamps. In contrast, vanadyl therapy increased insulin-induced glucose utilization significantly and had a small but nonsignificant effect on insulin-mediated suppression of glucose production in diabetic rats. The tyrosine kinase activity of liver- and muscle-derived insulin receptors from diabetic rats that underwent clamp study, which reflected the in vivo phosphorylation state of insulin receptor, was not altered by vanadyl treatment. In conclusion, these results show that augmentation of peripheral glucose utilization is the major determinant of the antidiabetic action of vanadyl and support the notion that the action of vanadyl is independent of insulin-receptor kinase activity.


Assuntos
Diabetes Mellitus Experimental/metabolismo , Hipoglicemiantes , Fígado/metabolismo , Proteínas Tirosina Quinases/metabolismo , Receptor de Insulina/metabolismo , Vanadatos/farmacologia , Animais , Glicemia/metabolismo , Diabetes Mellitus Experimental/enzimologia , Cinética , Masculino , Ratos , Ratos Endogâmicos , Receptor de Insulina/efeitos dos fármacos , Receptor de Insulina/isolamento & purificação , Valores de Referência
18.
Diabetes ; 37(7): 885-90, 1988 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-3290006

RESUMO

To test the hypothesis that glucose transport is rate limiting for skeletal muscle glucose metabolism, intracellular free glucose was measured in in situ abdominal wall muscle and liver that were rapidly freeze-clamped and removed from normal and streptozocin-induced diabetic (STZ-D) Sprague-Dawley rats exposed to different concentrations of serum insulin and glucose achieved by 90-min glucose clamps. Three groups of anesthetized normal (n = 17) and three groups of STZ-D (n = 19) animals were studied. In each group, infusions were adjusted to expose rats to basal, euglycemic-hyperinsulinemic, and hyperglycemic-hyperinsulinemic conditions. Final steady-state serum glucose and insulin concentrations (mean +/- SE) achieved in the six groups ranged from 112 +/- 2 to 467 +/- 26 mg/dl and from 5.8 +/- 1.9 to 3644 +/- 116 microU/ml, respectively. Intracellular free-glucose content of all tissue was calculated from total tissue glucose content minus the contribution of glucose in extracellular water estimated with [14C]inulin. Intracellular free glucose was not detected in muscle of any of the experimental groups. However, intracellular free glucose was detected in liver from all normal and STZ-D rats, and the calculated intracellular concentrations of free glucose correlated with serum glucose concentrations (r = .68, P less than .001). We conclude that intracellular free glucose does not accumulate, regardless of glucose or insulin concentration, in normal skeletal muscle and muscle made insulin resistant (by STZ-D), suggesting that glucose transport remains rate limiting.


Assuntos
Diabetes Mellitus Experimental/metabolismo , Glucose/metabolismo , Músculos/metabolismo , Animais , Transporte Biológico , Glicemia/metabolismo , Água Corporal/metabolismo , Insulina/sangue , Líquido Intracelular/metabolismo , Cinética , Fígado/metabolismo , Masculino , Ratos , Ratos Endogâmicos
19.
J Pharm Pharm Sci ; 8(1): 39-46, 2005 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-15946596

RESUMO

PURPOSE: Asparagus racemosus Wild root has been used traditionally in Ayurveda for the treatment of diarrhoea and dysentery. However, the claims of Ayurveda need to be validated by a suitable experimental model. Therefore, the present study was undertaken to evaluate the effect of ethanol and aqueous extracts of Asparagus racemosus for its antidiarrhoeal potential against several experimental models of diarrhoea in Albino Wistar rats. METHODS: The antidiarrhoeal activity of ethanol and aqueous extracts of Asparagus racemosus root was evaluated using castor oil-induced diarrhoea model in rats. Further, we evaluated the effect of ethanol and aqueous extracts on gastrointestinal tract motility after charcoal meal administration and PGE2 induced intestinal fluid accumulation (enteropooling). Loperamide was used as positive control. RESULTS: The plant extracts showed significant (P < 0.05) inhibitor activity against castor oil induced diarrhoea and PGE2 induced enteropooling in rats when tested at 200 mg/kg. Both extracts also showed significant (P < 0.001) reduction in gastrointestinal motility in charcoal meal test in rats. CONCLUSION: The results point out the possible anti-diarrhoeal effect of the plant extracts and substantiate the use of this herbal remedy as a non-specific treatment for diarrhoea in folk medicine.


Assuntos
Antidiarreicos/uso terapêutico , Asparagus , Diarreia/tratamento farmacológico , Fitoterapia/métodos , Raízes de Plantas , Animais , Diarreia/fisiopatologia , Feminino , Masculino , Extratos Vegetais/uso terapêutico , Ratos , Ratos Wistar
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