Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 8 de 8
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Vet Anaesth Analg ; 45(4): 529-538, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29705687

RESUMO

OBJECTIVE: To test the hypothesis that plasma propofol concentration (PPC) is associated with anesthetic effect in koi carp administered propofol by immersion. STUDY DESIGN: Prospective study. ANIMALS: Twenty mature koi carp (mean ± standard deviation, 409.4 ± 83.7 g). METHODS: Fish were immersed in propofol (5 mg L-1). Physiological variables and induction and recovery times were recorded. In phase I, blood was sampled for PPC immediately following induction and at recovery. In phase II, following induction, fish were maintained with propofol (4 mg L-1) via a recirculating system for 20 minutes. Following established induction, blood was sampled at 1, 10 and 20 minutes. In phase III (n = 19), fish were anesthetized as in phase II with blood sampled nine times in a sparse sampling strategy. Simultaneously, a pharmacodynamics rubric was used to evaluate anesthetic depth. PPC was determined using high performance liquid chromatography with fluorescence detection. Following evaluation of normality, data were analyzed using paired t test or Spearman correlation test (significance was set at p < 0.05). RESULTS: In phase I, mean PPCs at induction (20.12 µg mL-1) and recovery (11.62 µg mL-1) were different (p < 0.001). In phase II, only mean PPCs at induction (17.92 µg mL-1) and 10 minutes (21.50 µg mL-1) were different (p = 0.013). In phase III, a correlation between PPCs and the pharmacodynamic rubric scores was found (p < 0.001, r = -0.93). There was no correlation between PPCs and recovery time (p = 0.057, r = 0.433). A two-compartment open model was chosen for the pharmacokinetic model. Absorption rate constant, elimination rate constant and intercompartmental rate constant were 0.48, 0.006 and 0.02 minute-1, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: Measurable PPCs were achieved in koi carp anesthetized with propofol by immersion. Anesthetic depth of fish was negatively correlated with PPCs, but recovery time was not.


Assuntos
Carpas/metabolismo , Hipnóticos e Sedativos/farmacocinética , Propofol/farmacocinética , Período de Recuperação da Anestesia , Animais , Cromatografia Líquida de Alta Pressão/veterinária , Sedação Profunda/métodos , Sedação Profunda/veterinária , Frequência Cardíaca/efeitos dos fármacos , Hipnóticos e Sedativos/administração & dosagem , Hipnóticos e Sedativos/sangue , Hipnóticos e Sedativos/farmacologia , Imersão , Propofol/administração & dosagem , Propofol/sangue , Propofol/farmacologia
2.
PLoS One ; 16(4): e0249179, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33844694

RESUMO

There is no FDA approved therapy for the treatment of celiac disease (CeD), aside from avoidance of dietary gluten. Larazotide acetate (LA) is a first in class oral peptide developed as a tight junction regulator, which is a lead candidate for management of CeD. A delayed release formulation was tested in vitro and predicted release in the mid duodenum and jejunum, the target site of CeD. The aim of this study was to follow the concentration versus time profile of orally administered LA in the small intestine using a porcine model. A sensitive liquid chromatography/tandem mass spectrometry method was developed to quantify LA concentrations in porcine intestinal fluid samples. Oral dosing of LA (1 mg total) in overnight fasted pigs resulted in time dependent appearance of LA in the distal duodenum and proximal jejunum. Peak LA concentrations (0.32-1.76 µM) occurred at 1 hour in the duodenum and in proximal jejunum following oral dosing, with the continued presence of LA (0.02-0.47 µM) in the distal duodenum and in proximal jejunum (0.00-0.43 µM) from 2 to 4 hours following oral dosing. The data shows that LA is available in detectable concentrations at the site of CeD.


Assuntos
Doença Celíaca/tratamento farmacológico , Oligopeptídeos/farmacocinética , Administração Oral , Animais , Liberação Controlada de Fármacos , Duodeno/metabolismo , Jejuno/metabolismo , Oligopeptídeos/administração & dosagem , Oligopeptídeos/uso terapêutico , Suínos
3.
Steroids ; 74(7): 595-601, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19071151

RESUMO

Luteinizing hormone (LH) mediates many important processes in ovarian follicles, including cumulus cell expansion, changes in gap junction expression and activity, sterol and steroid production, and the release of paracrine signaling molecules. All of these functions work together to trigger oocyte maturation (meiotic progression) and subsequent ovulation. Many laboratories are interested in better understanding both the extra-oocyte follicular processes that trigger oocyte maturation, as well as the intra-oocyte molecules and signals that regulate meiosis. Multiple model systems have been used to study LH-effects in the ovary, including fish, frogs, mice, rats, pigs, and primates. Here we provide a brief summary of oocyte maturation, focusing primarily on steroid-triggered meiotic progression in frogs and mice. Furthermore, we present new studies that implicate classical steroid receptors rather than alternative non-classical membrane steroid receptors as the primary regulators of steroid-mediated oocyte maturation in both of these model systems.


Assuntos
Oócitos/crescimento & desenvolvimento , Oogênese/fisiologia , Receptores de Esteroides/fisiologia , Testosterona/fisiologia , Animais , Feminino , Camundongos , Ovário/metabolismo , Xenopus laevis
4.
J Exp Clin Cancer Res ; 34: 31, 2015 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-25888489

RESUMO

PURPOSE: The anti-tumor activity of glucose analogs 2-deoxy-glucose (2-DG) and D-allose was investigated alone or in combination with p38 mitogen-activated protein kinase (MAPK) inhibitor SB202190 or platinum analogs as a strategy to pharmacologically target glycolytic tumor phenotypes. METHODS: Hypoxia inducible factor-1 alpha (HIF-1α) protein accumulation in pancreatic cell lines treated with SB202190 alone and in combination with glucose analogs was analyzed by Western blot. HIF-1α transcriptional activity was measured in MIA PaCa-2 cells stably transfected with a hypoxia response element luciferase reporter following treatment with glucose analogs alone, and in combination with SB202190. Induction of cleaved poly(ADP-ribose) polymerase (PARP) was measured by Western blot in the MIA PaCa-2 cells. In vitro anti-proliferative activity of 2-DG and D-allose alone, or in combination with oxaliplatin (pancreatic cell lines), cisplatin (ovarian cell lines), or with SB202190 were investigated using the MTT assay. RESULTS: SB202190 decreased HIF-1α protein accumulation and transcriptional activity. 2-DG demonstrated greater anti-proliferative activity than D-allose. Pre-treatment with SB202190 enhanced activity of both 2-DG and D-allose in MIA PaCa-2, BxPC-3, ASPC-1, and SK-OV-3 cells. The combination of D-allose and platinum agents was additive to moderately synergistic in all but the OVCAR-3 and HEY cells. SB202190 pre-treatment further enhanced activity of D-allose and 2-DG with platinum agents in most cell lines investigated. CONCLUSIONS: SB202190 induced sensitization of tumor cells to 2-DG and D-allose may be partially mediated by inhibition of HIF-1α activity. Combining glucose analogs and p38 MAPK inhibitors with chemotherapy may be an effective approach to target glycolytic tumor phenotypes.


Assuntos
Antineoplásicos/farmacologia , Desoxiglucose/farmacologia , Glucose/farmacologia , Proteínas Quinases p38 Ativadas por Mitógeno/antagonistas & inibidores , Hipóxia Celular , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Feminino , Genes Reporter , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Imidazóis/farmacologia , Ácido Láctico/metabolismo , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/metabolismo , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/metabolismo , Poli(ADP-Ribose) Polimerases/metabolismo , Piridinas/farmacologia , Transcrição Gênica
6.
J Exp Clin Cancer Res ; 33: 111, 2014 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-25612802

RESUMO

BACKGROUND: Carfilzomib (CFZ) is a proteasome inhibitor that selectively and irreversibly binds to its target and has been approved in the US for treatment of relapsed and refractory multiple myeloma. Phase 1B studies of CFZ reported signals of clinical activity in solid tumors, including small cell lung cancer (SCLC). The aim of this study was to investigate the activity of CFZ in lung cancer models. METHODS: A diverse panel of human lung cancer cell lines and a SHP77 small cell lung cancer xenograft model were used to investigate the anti-tumor activity of CFZ. RESULTS: CFZ treatment inhibited both the constitutive proteasome and the immunoproteasome in lung cancer cell lines. CFZ had marked anti-proliferative activity in A549, H1993, H520, H460, and H1299 non-small cell lung cancer (NSCLC) cell lines, with IC50 values after 96 hour exposure from <1.0 nM to 36 nM. CFZ had more variable effects in the SHP77 and DMS114 SCLC cell lines, with IC50 values at 96 hours from <1 nM to 203 nM. Western blot analysis of CFZ-treated H1993 and SHP77 cells showed cleavage of poly ADP ribose polymerase (PARP) and caspase-3, indicative of apoptosis, and induction of microtubule-associated protein-1 light chain-3B (LC3B), indicative of autophagy. In SHP77 flank xenograft tumors, CFZ monotherapy inhibited tumor growth and prolonged survival, while no additive or synergistic anti-tumor efficacy was observed for CFZ + cisplatin (CDDP). CONCLUSIONS: CFZ demonstrated anti-proliferative activity in lung cancer cell lines in vitro and resulted in a significant survival advantage in mice with SHP77 SCLC xenografts, supporting further pre-clinical and clinical investigations of CFZ in NSCLC and SCLC.


Assuntos
Antineoplásicos/farmacologia , Neoplasias Pulmonares/patologia , Oligopeptídeos/farmacologia , Carcinoma de Pequenas Células do Pulmão/patologia , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Modelos Animais de Doenças , Resistencia a Medicamentos Antineoplásicos , Feminino , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/mortalidade , Camundongos , Inibidores de Proteassoma/farmacologia , Carcinoma de Pequenas Células do Pulmão/tratamento farmacológico , Carcinoma de Pequenas Células do Pulmão/mortalidade , Carga Tumoral , Ensaios Antitumorais Modelo de Xenoenxerto
7.
Mol Endocrinol ; 25(6): 1055-65, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21454403

RESUMO

Previous work has demonstrated that cross talk between G protein-coupled LH receptors and epidermal growth factor receptors (EGFR) is essential for LH-induced steroid production in ovarian follicles and testicular Leydig cells. Here we demonstrate that G protein-coupled receptor (GPCR)/EGFR cross talk is also required for ACTH-induced steroidogenesis in Y1 adrenal cells. Moreover, we confirm that the signaling pathway from GPCR to Erk activation is conserved in all three steroidogenic tissues. ACTH or LH induces Gα(s), resulting in elevated cAMP and protein kinase A activation. cAMP/protein kinase A then triggers EGFR trans-activation, which promotes Erk signaling and subsequent steroidogenesis. Interestingly, although EGFR trans-activation is conserved in all three tissues, the specific mechanisms regulating this receptor cross talk differ. ACTH and LH trigger matrix metalloproteinase (MMP)-mediated release of EGFR ligands in adrenal and gonadal cells, respectively. However, this extracellular, ligand-dependent EGFR transactivation is required only for LH-induced steroidogenesis in ovarian follicles, reflecting the unique requirement of cell-cell cross talk for ovarian steroid production. Furthermore, MMP2 and MMP9 appear to regulate LH-induced steroidogenesis in mouse ovarian follicles, because a specific MMP2/9 inhibitor as well as the MMP2/9 inhibitor doxycycline suppress LH-induced follicular steroid production in vitro. Notably, although EGFR or MMP inhibition minimally affects estrous cycling in female mice, they attenuate ovarian steroidogenesis in response to LHR overstimulation in vivo. These results may have implications with regard to EGFR inhibitor use in various cancers as well as in polycystic ovarian syndrome, where excess LH-driven ovarian androgen production might be controlled by MMP2/9 inhibition.


Assuntos
Glândulas Suprarrenais/metabolismo , Receptores ErbB/metabolismo , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Ovário/metabolismo , Progesterona/biossíntese , Receptor Cross-Talk , Receptores da Corticotropina/metabolismo , Glândulas Suprarrenais/citologia , Hormônio Adrenocorticotrópico/farmacologia , Animais , Butadienos/farmacologia , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Doxiciclina/farmacologia , Receptores ErbB/antagonistas & inibidores , MAP Quinases Reguladas por Sinal Extracelular/antagonistas & inibidores , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Feminino , Gonadotropinas Equinas/farmacologia , Humanos , Hormônio Luteinizante/farmacologia , Inibidores de Metaloproteinases de Matriz , Camundongos , Nitrilas/farmacologia , Folículo Ovariano/efeitos dos fármacos , Ovário/citologia , Ovário/efeitos dos fármacos , Quinazolinas , Receptores do LH/antagonistas & inibidores , Receptores do LH/metabolismo , Transdução de Sinais , Tirfostinas/farmacologia
8.
Zebrafish ; 6(4): 319-27, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20047465

RESUMO

Germ cell tumors (GCTs) affect infants, children, and adults and are the most common cancer type in young men. Progress in understanding the molecular basis of GCTs has been hampered by a lack of suitable animal models. Here we report the identification of a zebrafish model of highly penetrant, heritable testicular GCT isolated as part of a forward genetic screen for cancer susceptibility genes. The mutant line develops spontaneous testicular tumors at a median age of 7 months, and pedigree analysis indicates dominant inheritance of the GCT susceptibility trait. The zebrafish model exhibits disruption of testicular tissue architecture and the accumulation of primitive, spermatogonial-like cells with loss of spermatocytic differentiation. Radiation treatment leads to apoptosis of the tumor cells and tumor regression. The GCT-susceptible line can serve as a model for understanding the mechanisms regulating germ cells in normal development and disease and as a platform investigating new therapeutic approaches for GCTs.


Assuntos
Modelos Animais de Doenças , Regulação Neoplásica da Expressão Gênica , Predisposição Genética para Doença , Neoplasias Embrionárias de Células Germinativas/genética , Peixe-Zebra/genética , Animais , Diferenciação Celular , Feminino , Humanos , Masculino , Mutação , Neoplasias Embrionárias de Células Germinativas/patologia , Neoplasias Embrionárias de Células Germinativas/radioterapia , Linhagem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA