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1.
J Insect Physiol ; 72: 61-69, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25497117

RESUMO

In the present study, we investigated the modulatory effects of ecdysteroidogenesis of prothoracic glands (PGs) by bombyxin, an endogenous insulin-like peptide in the silkworm, Bombyx mori. The results showed that bombyxin stimulated ecdysteroidogenesis during a long-term incubation period and in a dose-dependent manner. Moreover, the injection of bombyxin into day 4-last instar larvae increased ecdysteroidogenesis 24h after the injection, indicating its possible in vivo function. Phosphorylation of the insulin receptor and Akt, and the target of rapamycin (TOR) signaling were stimulated by bombyxin, and stimulation of Akt phosphorylation and TOR signaling appeared to be dependent on phosphatidylinositol 3-kinase (PI3K). Bombyxin inhibited the phosphorylation of adenosine 5'-monophosphate-activated protein kinase (AMPK), and the inhibition appeared to be PI3K-independent. Bombyxin-stimulated ecdysteroidogenesis was blocked by either an inhibitor of PI3K (LY294002) or a chemical activator of AMPK (5-aminoimidazole-4-carboxamide-1-ß-D-ribofuranoside, AICAR), indicating involvement of the PI3K/Akt and AMPK signaling pathway. Bombyxin did not stimulate extracellular signal-regulated kinase (ERK) signaling of PGs. Bombyxin, but not prothoracicotropic hormone (PTTH) stimulated cell viability of PGs. In addition, bombyxin treatment also affected mRNA expression levels of insulin receptor, Akt, AMPKα, -ß, and -γ in time-dependent manners. These results suggest that bombyxin modulates ecdysteroidogenesis in B. mori PGs during development.


Assuntos
Bombyx/metabolismo , Ecdisteroides/biossíntese , Neuropeptídeos/farmacologia , Aminoimidazol Carboxamida/agonistas , Aminoimidazol Carboxamida/análogos & derivados , Animais , Bombyx/crescimento & desenvolvimento , Cromonas/farmacologia , Glândulas Endócrinas/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Hormônios de Inseto/biossíntese , Proteínas de Insetos/metabolismo , Larva/metabolismo , Morfolinas/farmacologia , Inibidores de Fosfoinositídeo-3 Quinase , Fosforilação , Ribonucleotídeos/agonistas , Transdução de Sinais
2.
PLoS One ; 8(5): e63102, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23671658

RESUMO

In this study, we investigated inhibition of the phosphorylation of adenosine 5'-monophosphate-activated protein kinase (AMPK) by prothoracicotropic hormone (PTTH) in prothoracic glands of the silkworm, Bombyx mori. We found that treatment with PTTH in vitro inhibited AMPK phosphorylation in time- and dose-dependent manners, as seen on Western blots of glandular lysates probed with antibody directed against AMPKα phosphorylated at Thr172. Moreover, in vitro inhibition of AMPK phosphorylation by PTTH was also verified by in vivo experiments: injection of PTTH into day 7 last instar larvae greatly inhibited glandular AMPK phosphorylation. PTTH-inhibited AMPK phosphorylation appeared to be partially reversed by treatment with LY294002, indicating involvement of phosphatidylinositol 3-kinase (PI3K) signaling. A chemical activator of AMPK (5-aminoimidazole-4-carboxamide-1-ß-d-ribofuranoside, AICAR) increased both basal and PTTH-inhibited AMPK phosphorylation. Treatment with AICAR also inhibited PTTH-stimulated ecdysteroidogenesis of prothoracic glands. The mechanism underlying inhibition of PTTH-stimulated ecdysteroidogenesis by AICAR was further investigated by determining the phosphorylation of eIF4E-binding protein (4E-BP) and p70 ribosomal protein S6 kinase (S6K), two known downstream signaling targets of the target of rapamycin complex 1 (TORC1). Upon treatment with AICAR, decreases in PTTH-stimulated phosphorylation of 4E-BP and S6K were detected. In addition, treatment with AICAR did not affect PTTH-stimulated extracellular signal-regulated kinase (ERK) phosphorylation, indicating that AMPK phosphorylation is not upstream signaling for ERK phosphorylation. Examination of gene expression levels of AMPKα, ß, and γ by quantitative real-time PCR (qRT-PCR) showed that PTTH did not affect AMPK transcription. From these results, it is assumed that inhibition of AMPK phosphorylation, which lies upstream of PTTH-stimulated TOR signaling, may play a role in PTTH stimulation of ecdysteroidogenesis.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Bombyx/efeitos dos fármacos , Ecdisteroides/biossíntese , Glândulas Endócrinas/efeitos dos fármacos , Hormônios de Inseto/farmacologia , Proteínas de Insetos/metabolismo , Proteínas Quinases Ativadas por AMP/genética , Sequência de Aminoácidos , Aminoimidazol Carboxamida/análogos & derivados , Aminoimidazol Carboxamida/farmacologia , Animais , Western Blotting , Bombyx/genética , Bombyx/metabolismo , Cromonas/farmacologia , Relação Dose-Resposta a Droga , Glândulas Endócrinas/metabolismo , Fatores de Iniciação em Eucariotos/metabolismo , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Isoenzimas/genética , Isoenzimas/metabolismo , Larva/efeitos dos fármacos , Larva/genética , Larva/metabolismo , Dados de Sequência Molecular , Morfolinas/farmacologia , Fosfatidilinositol 3-Quinases/metabolismo , Inibidores de Fosfoinositídeo-3 Quinase , Fosforilação/efeitos dos fármacos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Ribonucleotídeos/farmacologia , Proteínas Quinases S6 Ribossômicas 70-kDa/metabolismo , Homologia de Sequência de Aminoácidos , Fatores de Tempo
3.
Insect Biochem Mol Biol ; 42(4): 296-303, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22227406

RESUMO

The prothoracicotropic hormone (PTTH) is a stimulator of ecdysteroidogenesis in prothoracic gland of larval insects. Our recent studies showed that phosphoinositide 3-kinase (PI3K)/Akt signaling was involved in PTTH-stimulated ecdysteroidogenesis by Bombyx mori prothoracic glands. In the present study, downstream signaling of PI3K/Akt was further investigated. Results showed that PTTH rapidly enhanced the phosphorylation of translational repressor 4E-binding protein (4E-BP) and p70 ribosomal protein S6 kinase (S6K), two known downstream signaling targets of the target of rapamycin complex 1 (TORC1). PTTH stimulated 4E-BP phosphorylation in time- and dose-dependent manners. Injection of PTTH into day-6 last instar larvae greatly increased 4E-BP phosphorylation, verifying the in vitro effect. PTTH-stimulated 4E-BP phosphorylation was blocked by both LY294002 and wortmannin, indicating the involvement of PI3K. Mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) kinase (MEK) inhibitors (PD 98059 and U0126), did not inhibit PTTH-stimulated 4E-BP phosphorylation, implying that ERK signaling is not related to PTTH-stimulated 4E-BP phosphorylation. The phosphorylation of S6K was also stimulated by PTTH both in vitro and in vivo. PI3K signaling appears to be involved in PTTH-stimulated phosphorylation of S6K. Rapamycin, a specific inhibitor of mammalian TOR signaling attenuated PTTH-stimulated phosphorylation of 4E-BP and S6K of the glands, and greatly inhibited PTTH-stimulated ecdysteroidogenesis. Examination of gene expression levels of 4E-BP and S6K showed that PTTH inhibited mRNA levels of both 4E-BP and S6K, indicating that PTTH may exert its action at both the transcriptional and phosphorylation levels. These results suggest that PTTH/PI3K/TOR/4E-BP (S6K) signaling is involved in PTTH-stimulated ecdysteroidogenesis by prothoracic glands in B. mori.


Assuntos
Bombyx/metabolismo , Ecdisteroides/biossíntese , Hormônios de Inseto/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Animais , Butadienos , Flavonoides , Expressão Gênica , Quinases de Proteína Quinase Ativadas por Mitógeno/antagonistas & inibidores , Nitrilas , Inibidores de Fosfoinositídeo-3 Quinase , Fosforilação , Proteínas Quinases S6 Ribossômicas/metabolismo , Transdução de Sinais , Sirolimo
4.
J Insect Physiol ; 58(1): 102-9, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22085674

RESUMO

The present study investigated transcriptional regulation of the prothoracicotropic hormone (PTTH) receptor (Torso) gene in prothoracic glands (PGs) of the silkworm, Bombyx mori. The results showed that PTTH treatment in vitro time-dependently affected Torso mRNA levels, with an inhibitory effect being detected after 1- and 2-h periods of incubation. When methoprene, a juvenile hormone analogue (JHA), was applied to newly ecdysed last instar larvae, a decline in Torso mRNA levels during the early last larval instar was delayed compared to those treated with acetone. Injection of 20-hydroxyecdysone appeared to have a stimulatory effect on Torso mRNA levels. Torso mRNA levels were also shown to be nutrition-sensitive. From these results, it was suggested that Torso mRNA levels of the PGs appear to be hormonally regulated and nutrition-sensitive, and the endogenous precisely coordinated regulation of Torso mRNA levels may play a role in regulating ecdysteroidogenesis by PGs during development.


Assuntos
Bombyx/metabolismo , Ecdisterona/metabolismo , Regulação da Expressão Gênica , Hormônios de Inseto/metabolismo , Metamorfose Biológica , Receptores Proteína Tirosina Quinases/metabolismo , Animais , Bombyx/genética , Privação de Alimentos , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Metoprene , RNA Mensageiro/metabolismo , Receptores Proteína Tirosina Quinases/genética
5.
J Insect Physiol ; 57(7): 978-85, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21600900

RESUMO

Phosphorylation of the translational repressor 4E-binding protein (4E-BP) plays a critical role in regulating the overall translation levels in cells. In the present study, we investigated 4E-BP phosphorylation of Bombyx mori eggs by an immunoblot analysis of a conserved phospho-specific antibody to 4E-BP and demonstrated its role during embryonic development. When HCl treatment was applied to diapause-destined eggs at 20 h after oviposition, a dramatic increase in the phosphorylation of 4E-BP occurred 5 min after treatment with HCl, and high phosphorylation levels were maintained throughout embryonic stage in HCl-treated eggs compared to those in diapause (control) eggs. When HCl treatment was applied to diapause eggs on day 10 after oviposition, no dramatic activation in 4E-BP phosphorylation occurred, indicating stage-specific effects of HCl treatment. In both non-diapause eggs and eggs whose diapause had been terminated by chilling of diapausing eggs at 5°C for 70 days and then were transferred to 25°C, high phosphorylation levels of 4E-BP were also detected. Moreover, 4E-BP phosphorylation dramatically increased when dechorionated eggs were incubated in medium. The addition of rapamycin, a specific inhibitor of mammalian target of rapamycin (TOR) signaling, and LY294002, a phosphoinositide 3-kinase (PI3K) inhibitor, but not the mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) kinase (MEK) inhibitor, U0126, dose-dependently inhibited 4E-BP phosphorylation in dechorionated eggs, indicating that PI3K/TOR signaling is an upstream signaling event involved in 4E-BP phosphorylation. Examination of 4E-BP gene expression levels showed no differences between treatments with HCl and water in the first hour after treatment, indicating that changes in phosphorylation of 4E-BP upon HCl treatment are mainly regulated at the post-transcriptional level. In addition, MAPK pathways and glycogen synthase kinase (GSK)-3ß phosphorylation were not significantly affected in the first hour after HCl treatment. These results demonstrate that the rapid phosphorylation of 4E-BP is an early signaling event in embryonic development in the eggs whose diapause initiation was prevented by HCl treatment, thus being involved in the embryonic development of B. mori.


Assuntos
Bombyx/embriologia , Bombyx/enzimologia , Proteínas de Drosophila/metabolismo , Sequência de Aminoácidos , Animais , Bombyx/genética , Bombyx/metabolismo , Butadienos/química , Butadienos/metabolismo , Cromonas/química , Cromonas/metabolismo , Desenvolvimento Embrionário , Inibidores Enzimáticos/química , Inibidores Enzimáticos/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Regulação Enzimológica da Expressão Gênica , Ácido Clorídrico , Immunoblotting , Metamorfose Biológica , Proteínas Quinases Ativadas por Mitógeno/antagonistas & inibidores , Proteínas Quinases Ativadas por Mitógeno/química , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Morfolinas/química , Morfolinas/metabolismo , Nitrilas/química , Nitrilas/metabolismo , Óvulo/enzimologia , Óvulo/metabolismo , Fosfatidilinositol 3-Quinase/química , Fosfatidilinositol 3-Quinase/metabolismo , Inibidores de Fosfoinositídeo-3 Quinase , Fosforilação , Transdução de Sinais , Sirolimo/metabolismo , Serina-Treonina Quinases TOR/antagonistas & inibidores , Serina-Treonina Quinases TOR/química , Serina-Treonina Quinases TOR/metabolismo , Fatores de Tempo
6.
Insect Biochem Mol Biol ; 41(3): 197-202, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21199670

RESUMO

The prothoracicotropic hormone (PTTH) stimulates ecdysteroidogenesis by prothoracic gland in larval insects. Previous studies showed that Ca(2+), cAMP, extracellular signal-regulated kinase (ERK), and tyrosine kinase are involved in PTTH-stimulated ecdysteroidogenesis by the prothoracic glands of both Bombyx mori and Manduca sexta. In the present study, the involvement of phosphoinositide 3-kinase (PI3K)/Akt signaling in PTTH-stimulated ecdysteroidogenesis by B. mori prothoracic glands was further investigated. The results showed that PTTH-stimulated ecdysteroidogenesis was partially blocked by LY294002 and wortmannin, indicating that PI3K is involved in PTTH-stimulated ecdysteroidogenesis. Akt phosphorylation in the prothoracic glands appeared to be moderately stimulated by PTTH in vitro. PTTH-stimulated Akt phosphorylation was inhibited by LY294002. An in vivo PTTH injection into day 6 last instar larvae also increased Akt phosphorylation of the prothoracic glands. In addition, PTTH-stimulated ERK phosphorylation of the prothoracic glands was not inhibited by either LY294002 or wortmannin, indicating that PI3K is not involved in PTTH-stimulated ERK signaling. A23187 and thapsigargin, which stimulated B. mori prothoracic gland ERK phosphorylation and ecdysteroidogenesis, could not activate Akt phosphorylation. PTTH-stimulated ecdysteroidogenesis was not further activated by insulin, indicating the absence of an additive action of insulin and PTTH on the prothoracic glands. The present study, together with the previous demonstration that insulin stimulates B. mori ecdysteroidogenesis through PI3K/Akt signaling, suggests that crosstalk exists in B. mori prothoracic glands between insulin and PTTH signaling, which may play a critical role in precisely regulated ecdysteroidogenesis during development.


Assuntos
Bombyx/enzimologia , Ecdisteroides/biossíntese , Hormônios de Inseto/metabolismo , Transdução de Sinais , 1-Fosfatidilinositol 4-Quinase/metabolismo , Androstadienos/antagonistas & inibidores , Animais , Bombyx/metabolismo , Calcimicina/metabolismo , Cromonas/antagonistas & inibidores , Ecdisteroides/metabolismo , Insulina/metabolismo , Larva/enzimologia , Larva/metabolismo , Morfolinas/antagonistas & inibidores , Fosforilação , Proteínas Proto-Oncogênicas c-akt/metabolismo , Tapsigargina/metabolismo , Wortmanina
7.
Environ Mol Mutagen ; 51(4): 315-21, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20143344

RESUMO

Epidemiological studies have demonstrated that cooking oil fumes (COF) are an environmental risk factor for the development of lung adenocarcinoma among nonsmoking females in Taiwan. Aside from polycyclic aromatic hydrocarbons, aldehydes, especially trans, trans-2,4-decadienal (tt-DDE) are found to be abundant in COF. Although there is indication that tt-DDE induces DNA damage, the precise role of tt-DDE in the induction of DNA damage in lung cells is still not clear. When we assessed DNA breaks with the Comet assay, we found that the DNA breaks induced by 1 muM tt-DDE in human bronchial epithelial cells (BEAS-2B) could be significantly reduced by antioxidants, suggesting that oxidative stress was involved. Indeed, when tt-DDE-treated cells were coincubated with endonuclease III/formamidopyrimidine-DNA glycosylase or with nuclear extract (NE), an enhancement of DNA breaks was observed at 1 hr after tt-DDE exposure. Furthermore, when NE was incubated with an antibody against 8-oxoguanine DNA glycosylase (anti-OGG1), a reduction in tt-DDE/NE-induced DNA breaks could be demonstrated. Since OGG1 is a specific repair enzyme for 8-oxo-deoxyguanosine (8-oxo-dG), these findings indicated that 8-oxo-dG was involved. On the other hand, when NE was incubated with antibodies against nucleotide excision repair enzymes, there was a significant reduction in tt-DDE/NE-induced DNA breaks at 4 hr after tt-DDE treatment. These observations indicate that, in addition to early oxidative DNA damage, nonoxidative DNA damage such as bulky adduct formation, was also induced by tt-DDE. Our study further affirms that tt-DDE is genotoxic to human lung cells and can increase carcinogenic risk.


Assuntos
Aldeídos/toxicidade , Brônquios/efeitos dos fármacos , Dano ao DNA , Óleos Combustíveis/toxicidade , Brônquios/citologia , Linhagem Celular , Ensaio Cometa , Adutos de DNA/metabolismo , Quebras de DNA/efeitos dos fármacos , Feminino , Humanos , Estresse Oxidativo/efeitos dos fármacos , Mucosa Respiratória/efeitos dos fármacos , Mucosa Respiratória/metabolismo
8.
Am J Emerg Med ; 26(2): 252.e3-4, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18272132

RESUMO

Transdiaphragmatic intercostal hernia (TDIH) is a rare consequence from blunt chest-abdominal injury. The diagnosis of TDIH is often delayed. We report a patient who had a history of left-sided upper abdominal blunt injury 2 months before admission presented with a newly developed, massive pleural effusion and clinical manifestations of intestinal obstruction. A multidetector-row computed tomography confirmed the diagnosis of traumatic diaphragm rupture and TDIH. He underwent thoracotomy with reduction of herniated viscera and repair of the diaphragm and chest wall. He was discharged uneventfully and remained well on follow-up at 2 months.


Assuntos
Traumatismos Abdominais/complicações , Hérnia Diafragmática Traumática/etiologia , Derrame Pleural/etiologia , Idoso , Hérnia Diafragmática Traumática/diagnóstico por imagem , Hérnia Diafragmática Traumática/cirurgia , Humanos , Masculino , Derrame Pleural/diagnóstico por imagem , Derrame Pleural/cirurgia , Radiografia
9.
Arch Toxicol ; 81(1): 45-55, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16676162

RESUMO

Piper betel leaves (PBL) are used in Chinese folk medicine for the treatment of various disorders. PBL has the biological capabilities of detoxication, antioxidation, and antimutation. In this study, we evaluated the antihepatotoxic effect of PBL extract on the carbon tetrachloride (CCl(4))-induced liver injury in a rat model. Fibrosis and hepatic damage, as reveled by histology and the activities of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were induced in rats by an administration of CCl(4) (8%, 1 ml/kg body weight) thrice a week for 4 weeks. PBL extract significantly inhibited the elevated AST and ALT activities caused by CCl(4) intoxication. It also attenuated total glutathione S-transferase (GST) activity and GST alpha isoform activity, and on the other hand, enhanced superoxide dismutase (SOD) and catalase (CAT) activities. The histological examination showed the PBL extract protected liver from the damage induced by CCl(4) by decreasing alpha-smooth muscle actin (alpha-sma) expression, inducing active matrix metalloproteinase-2 (MMP2) expression though Ras/Erk pathway, and inhibiting TIMP2 level that consequently attenuated the fibrosis of liver. The data of this study support a chemopreventive potential of PBL against liver fibrosis.


Assuntos
Tetracloreto de Carbono/toxicidade , Medicamentos de Ervas Chinesas/uso terapêutico , Cirrose Hepática Experimental/prevenção & controle , Piper betle/química , Folhas de Planta/química , Actinas/metabolismo , Alanina Transaminase/metabolismo , Animais , Aspartato Aminotransferases/metabolismo , Western Blotting , Peso Corporal/efeitos dos fármacos , Tetracloreto de Carbono/administração & dosagem , Catalase/metabolismo , Relação Dose-Resposta a Droga , Medicamentos de Ervas Chinesas/química , Medicamentos de Ervas Chinesas/isolamento & purificação , Glutationa Transferase/metabolismo , Radical Hidroxila/metabolismo , Injeções Intraperitoneais , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Cirrose Hepática Experimental/induzido quimicamente , Cirrose Hepática Experimental/tratamento farmacológico , Masculino , Metaloproteinase 2 da Matriz/metabolismo , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , Fitoterapia , Ratos , Ratos Wistar , Superóxido Dismutase/metabolismo
10.
Am Surg ; 72(5): 419-26, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16719197

RESUMO

Carcinoma of the parathyroid is a rare malignancy that can be cured surgically if the proper diagnosis and treatment is given initially. Arriving to the clinical suspicion of a malignancy preoperatively is by far the most important step for a good prognosis. Our goal is to review the correlation between clinical and final histopathological findings that can arouse the suspicion of such malignancy and their true predictive value in the diagnosis. All patients that underwent surgical removal of the parathyroid mass between March of 1992 and March of 2003 were reviewed retrospectively at Providence Hospital and Medical Centers. Among 168 patients who underwent parathyroid excision, 14 (8.3%) had hyperplasia of the parathyroid, 121 (72%) had benign adenoma, 25 (14.8%) had other benign lesions, and 8 (4.7%) patients had primary carcinoma of the parathyroid confirmed by pathology. Our mean serum calcium level was 11.57 mg/dL, which was lower than the mean level (12 mg/dL) for benign hyperparathyroidism. The mean tumor size was 2.18 cm, smaller than the proposed for malignant criteria, and none of the eight patients (0%) had any symptoms of hypercalcemia at the time of diagnosis. Seven of eight patients (87.5%) had frank signs of invasion together with other histological features, and two patients had associated papillary carcinoma of the thyroid. Five patients from our series did not meet clinical criteria for malignancy (tumor size > 3 cm, palpable mass, and serum calcium > 14 mg/dL), but had undisputable histological findings (high mitotic pattern, fibrous trabeculae, capsular invasion, vascular invasion, and nodular involvement). On the other hand, 17 patients with benign histology had tumors greater than 3 cm, and an additional 18 had palpable masses on physical examination. We believe that these patients need to be followed closely. The patients with diagnosis of parathyroid carcinoma, their kindred, and those with large adenomas may benefit from genetic screening for HRTP2 gene mutations in search of early detection of tumors suspicious for malignancy. This is based on the fact that we did not find correlation between the clinical presentation and the histological features in our patients with proven malignancy.


Assuntos
Neoplasias das Paratireoides/diagnóstico , Neoplasias das Paratireoides/patologia , Adenoma/sangue , Adenoma/diagnóstico , Adenoma/cirurgia , Idoso de 80 Anos ou mais , Cálcio/sangue , Feminino , Humanos , Hiperparatireoidismo/etiologia , Masculino , Pessoa de Meia-Idade , Mitose , Invasividade Neoplásica , Neoplasias das Paratireoides/sangue , Neoplasias das Paratireoides/cirurgia , Paratireoidectomia
11.
Arch Toxicol ; 80(6): 319-27, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16341694

RESUMO

Piper betel leaves (PBL) are used in Chinese folk medicine for the treatment of various disorders. PBL has the biological capabilities of de-toxication, anti-oxidation and anti-mutation. In this study we first examined the effect of PBL extract on the activity of Glutathione S-transferase (GST) isoforms, and found that it inhibited total GST and the alpha class of GST (GSTA), but not the pi class of GST (GSTP), and the mu class of GST (GSTM), activity in Hep G2 cells. RT-PCR results verified a reduction in the expression of GSTA1. Next, we examined whether PBL extract could increase the sensitivity of Hep G2 cells to anti-cancer drugs. The data showed that the cytotoxicity of cisplatin was significantly enhanced by the presence of PBL extract, accompanied by a reduction in the expression of multidrug resistance protein 2 (MRP2). These effects of PBL extract were compared to its major constitute, eugenol. Although eugenol decreased MRP2 level more effectively than PBL extract, it exhibited less sensitizing effect. In conclusion, we demonstrated that PBL extract was able to increase the sensitivity of Hep G2 cells to cisplatin via at least two mechanisms, reducing the expression of MRP2 and inhibiting the activity of total GST and the expression of GSTA. The data of this study support an application of PBL as an additive to reduce drug resistance.


Assuntos
Antineoplásicos/farmacologia , Cisplatino/farmacologia , Inibidores Enzimáticos/farmacologia , Hepatócitos/efeitos dos fármacos , Piper betle , Extratos Vegetais/farmacologia , Fracionamento Celular , Linhagem Celular Tumoral/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Medicamentos de Ervas Chinesas , Eugenol/farmacologia , Fase G2 , Glutationa Transferase/metabolismo , Hepatócitos/enzimologia , Hepatócitos/patologia , Humanos , Isoenzimas , Neoplasias Hepáticas/tratamento farmacológico , Proteínas de Membrana Transportadoras/metabolismo , Proteína 2 Associada à Farmacorresistência Múltipla , Proteínas Associadas à Resistência a Múltiplos Medicamentos/metabolismo , Compostos Organoplatínicos/farmacologia , Oxaliplatina , Folhas de Planta/química
12.
Toxicol Appl Pharmacol ; 208(2): 155-62, 2005 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-16183389

RESUMO

Geniposide, an iridoid glycoside isolated from the fruit of Gardenia jasminoides Ellis, has biological capabilities of detoxication, antioxidation, and anticarcinogenesis. We have recently found that geniposide possesses a potential for detoxication by inducing GST activity and the expression of GST M1 and GST M2 subunits. In this study, the signaling pathway of geniposide leading to the activation of GSH S-transferase (GST) was investigated. Primary cultured rat hepatocytes were treated with geniposide in the presence or absence of mitogen-activated protein kinase (MAPK) inhibitors and examined for GST activity, expression of GST M1 and M2 subunits, and protein levels of MAPK signaling proteins. Western blotting data demonstrated that geniposide induced increased protein levels of GST M1 and GST M2 (approximately 1.76- and 1.50-fold of control, respectively). The effect of geniposide on the increased protein levels of GST M1 and GST M2 was inhibited by the MEK-1 inhibitor PD98059, but not by other MAPK inhibitors. The GST M1 and GST M2 transcripts as determined by RT-PCR and GST activity were also inhibited concurrently by the MEK-1 inhibitor PD98059. The protein levels of up- and down-stream effectors of the MEK-1, including Ras, Raf, and Erk1/2, and the phosphorylation state of Erk1/2 were found to be induced by geniposide, indicating a two-phase influence of geniposide. The results suggest that geniposide induced GST activity and the expression of GST M1 and GST M2 acting through MEK-1 pathway by activating and increasing expression of Ras/Raf/MEK-1 signaling mediators.


Assuntos
Glutationa Transferase/biossíntese , Hepatócitos/enzimologia , Iridoides/farmacologia , MAP Quinase Quinase 1/genética , MAP Quinase Quinase 1/fisiologia , Piranos/farmacologia , Animais , Ativação Enzimática/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Glutationa Transferase/genética , Hepatócitos/efeitos dos fármacos , Isoenzimas/biossíntese , Isoenzimas/genética , Masculino , Proteínas Quinases Ativadas por Mitógeno/antagonistas & inibidores , Fosforilação , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacos , Transcrição Gênica
13.
JSLS ; 9(1): 87-90, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-15791978

RESUMO

BACKGROUND: Complications following laparoscopic cholecystectomy are encountered infrequently due to increasing proficiency in laparoscopic surgery. The occurrence of portal venous thrombosis following laparoscopic cholecystectomy has not been previously described and forms the basis of this report. METHODS: A healthy, 32-year-old, female on oral contraceptives underwent an uneventful laparoscopic cholecystectomy for symptomatic gallbladder disease. Sequential compression devices and mini-dose unfractionated heparin were used before the procedure. The patient was discharged home on the first postoperative day without complaints. She returned 1 week later with nausea, bloating, and diffuse abdominal pain. RESULTS: Ultrasonography of the abdomen revealed thrombosis of the portal vein not seen in the preoperative ultrasound and the superior mesenteric vein. Computer tomography of the abdomen and pelvis on the same day confirmed this finding and showed a wedge-shaped infarction of the right lobe of the liver. The patient was anticoagulated with intravenous heparin. An extensive coagulation workup revealed elevation of the Immunoglobulin G anticardiolipin antibody. A percutaneous transhepatic portal vein thrombectomy was performed. A postprocedure duplex ultrasound of the abdomen demonstrated recannalization of the portal venous system with no flow voids. Anticoagulation therapy was continued, and the patient was discharged home with resolution of her ileus. She was maintained on a therapeutic dose of warfarin. CONCLUSIONS: This case demonstrates an unusual complication of laparoscopic cholecystectomy. It may have resulted from the use of oral contraceptives, elevation of the Immunoglobulin G anticardiolipin antibody, unrecognized trauma, and was accentuated by the pneumoperitoneum generated for the performance of the laparoscopic cholecystectomy. Our case report provides insight and poses questions regarding necessary perioperative measures for thromboprophylaxis in young females on oral contraceptives undergoing elective laparoscopic abdominal surgery.


Assuntos
Colecistectomia Laparoscópica/efeitos adversos , Veia Porta , Trombose/etiologia , Adulto , Feminino , Humanos
15.
Pharmacology ; 70(1): 15-22, 2004 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-14646352

RESUMO

Geniposide, an iridoid glycoside isolated from the fruit of Gardenia jasminoides Ellis, has the biological capabilities of detoxication, antioxidation, and anticarcinogenesis. In this study, the mechanism of geniposide affecting the GST (glutathione S-transferase) system was investigated. Primary cultured rat hepatocytes were treated with geniposide and examined for total GST activity and expression of GST subunits. The results showed that the geniposide-induced GST activity was dose and time dependent. Western blotting data demonstrated that geniposide induced increased protein levels of GSTM1 and GSTM2 (approximately 1.7- and 1.8-fold of control, respectively), but did not increase those of GSTA1. The corresponding transcripts levels were confirmed by RT-PCR. Using PD98059, the effect of geniposide was verified to be via the MEK pathway. The results suggest that geniposide possesses a potential for detoxication by inducing GST activity via increasing the transcription of GSTM1 and GSTM2.


Assuntos
Indução Enzimática/efeitos dos fármacos , Glutationa Transferase/biossíntese , Hepatócitos/efeitos dos fármacos , Hepatócitos/enzimologia , Iridoides/farmacocinética , Iridoides/uso terapêutico , Animais , Células Cultivadas , Relação Dose-Resposta a Droga , Medicamentos de Ervas Chinesas , Indução Enzimática/genética , Flavonoides/farmacologia , Frutas , Glutationa Transferase/antagonistas & inibidores , Glutationa Transferase/genética , Glicosídeos/administração & dosagem , Glicosídeos/farmacocinética , Glicosídeos/uso terapêutico , Hepatite/tratamento farmacológico , Iridoides/administração & dosagem , Isoenzimas/biossíntese , Masculino , Extratos Vegetais , Piranos , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , Rubiaceae , Fatores de Tempo
16.
Am Surg ; 68(3): 281-4; discussion 284-5, 2002 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11893108

RESUMO

There is an ongoing debate about the proposed regionalization of pancreaticoduodenectomies. The purpose of our study is to demonstrate that good outcomes can be achieved in a well-managed low-volume community hospital. We retrospectively analyzed pathologic findings, morbidity, mortality, and one-year survival in 32 patients who underwent pancreaticoduodenectomy at Providence Hospital over a 10-year period and compared these results with data collected at Johns Hopkins, and the Mayo Clinic. The patients had a mean age of 68.5 +/- 2.96 years; 56.3 per cent were female and 71.9 per cent were white. Overall in our series 90.6 per cent of specimens were found to be malignant, which is statistically higher than the 68 per cent at Johns Hopkins (P = 0.013) and not significantly different from Mayo Clinic (76%). The 30-day mortality rate at Providence Hospital was 3.1 per cent, which is not statistically different from Johns Hopkins (1.3%) and Mayo Clinic (3.6%). One-year survival rate at Providence Hospital was 59.4 per cent, which is significantly different from 79 per cent at Johns Hopkins (P = 0.016). The one-year survival rate at Providence Hospital is higher than an approximately 50 per cent average reported nationally. The postoperative complication rate was 62.5 per cent; the most common complication was delayed early gastric emptying (28.1%). A statistical difference in morbidity exists between Providence Hospital and Johns Hopkins (P = 0.027) but not between Providence Hospital and Mayo Clinic (46%). The higher rate of malignant disease treated in the population at Providence Hospital may contribute to a higher complication rate and lower one-year survival rate than the reported rates at Johns Hopkins because of the poorer health of cancer patients. However, statistical analysis of mortality rates for pancreaticoduodenectomy at Providence Hospital show no difference from mortality rates at Johns Hopkins and Mayo Clinic. Therefore in low-volume community hospitals pancreaticoduodenectomy can be performed safely as evidenced by a comparable low mortality rate and a high one-year survival rate.


Assuntos
Neoplasias Pancreáticas/mortalidade , Neoplasias Pancreáticas/cirurgia , Pancreaticoduodenectomia/métodos , Idoso , Distribuição de Qui-Quadrado , Intervalo Livre de Doença , Feminino , Hospitais Comunitários , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Pancreáticas/diagnóstico , Pancreaticoduodenectomia/efeitos adversos , Probabilidade , Prognóstico , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Sensibilidade e Especificidade , Taxa de Sobrevida , Resultado do Tratamento
17.
Curr Surg ; 59(3): 330-2, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-16093158

RESUMO

PURPOSE: Completion of a United States surgical residency enables the graduate to provide service in most populated areas. Graduates are technically well trained and efficient in performing most surgeries. United States-based teaching facilities are generally furnished with technically advanced supplies and equipment. Access to financial reserve is also available. Surgery in third-world countries, however, can be challenging. These countries, particularly in the outskirts, lack supplies and innovation, such as advanced equipment, medication, and personnel. Compounding the problem, patients tend to have advanced pathology and diminished financial means. METHODS: The United States-based surgical team annually collaborated with a medical mission to provide service to a rural community of the Dominican Republic. A senior-level surgery resident accompanied the surgeon. Surgical supplies were donated and brought with the team. The average number of cases performed was approximately 37 per week. All procedures were performed for symptomatic pathology. All patients were preoperatively screened and evaluated for comorbidities. RESULTS: No immediate complications occurred. Local physicians provide long-term follow-up. Pediatric procedures were not performed secondary to lack of postoperative resources. CONCLUSIONS: Surgical experience is beneficial to the recipient community and the resident surgeon. The extent of pathology and lack of resources enforces efficiency and broadens skills. This opportunity can potentially prepare surgeons for the growing need of rural surgery.

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