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1.
R Soc Open Sci ; 8(2): 201686, 2021 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-33972861

RESUMO

The diverse living Australian lizard fauna contrasts greatly with their limited Oligo-Miocene fossil record. New Oligo-Miocene fossil vertebrates from the Namba Formation (south of Lake Frome, South Australia) were uncovered from multiple expeditions from 2007 to 2018. Abundant disarticulated material of small vertebrates was concentrated in shallow lenses along the palaeolake edges, now exposed on the western of Lake Pinpa also known from Billeroo Creek 2 km northeast. The fossiliferous lens within the Namba Formation hosting the abundant aquatic (such as fish, platypus Obdurodon and waterfowl) and diverse terrestrial (such as possums, dasyuromorphs and scincids) vertebrates and is hereafter recognized as the Fish Lens. The stratigraphic provenance of these deposits in relation to prior finds in the area is also established. A new egerniine scincid taxon Proegernia mikebulli sp. nov. described herein, is based on a near-complete reconstructed mandible, maxilla, premaxilla and pterygoid. Postcranial scincid elements were also recovered with this material, but could not yet be confidently associated with P. mikebulli. This new taxon is recovered as the sister species to P. palankarinnensis, in a tip-dated total-evidence phylogenetic analysis, where both are recovered as stem Australian egerniines. These taxa also help pinpoint the timing of the arrival of scincids to Australia, with egerniines the first radiation to reach the continent.

2.
Nutr Metab Cardiovasc Dis ; 28(6): 582-591, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29691148

RESUMO

BACKGROUND AND AIMS: Angiotensin receptor blockers (ARB) and angiotensin converting enzyme inhibitors (ACEI) reduce cardiovascular events in the general population. Maintenance hemodialysis (MHD) patients are at high cardiovascular risk but few studies have directly addressed the comparative efficacy of these drugs. MHD disrupts the normally atheroprotective actions of high density lipoprotein (HDL), therefore, we compared ACEI or ARB treatment on HDL functions in MHD. METHODS AND RESULTS: HDL was isolated at the starting point (pre) and 3-6 months later (post) in 30 MHD randomly assigned to placebo, ramipril or valsartan. Outcomes included cholesterol efflux, inflammatory cytokine response, effects on Toll-like receptors (TLR), superoxide production, methylarginine and serum amyloid A (SAA) levels. HDL from ARB- or ACEI-treated subjects was more effective in maintaining efflux than HDL of placebo. HDL from ARB- or ACEI-treated subjects but not placebo lessened cellular superoxide production. In contrast, neither ARB nor ACEI improved HDL anti-inflammatory effect. Indeed, HDL of ACEI-treated subjects potentiated the cytokine responses in association with activation of TLR but did not alter the HDL content of methylarginines or SAA. CONCLUSION: Both ACEI and ARB stabilized HDL cholesterol acceptor function and sustained cellular anti-oxidative effects but not anti-inflammatory effects, and ACEI-treatment instead amplified the HDL inflammatory response. The findings reveal possible utility of antagonizing angiotensin actions in MDH and suggest a possible mechanism for superiority of ARB vs ACEI in the setting of advanced kidney disease.


Assuntos
Bloqueadores do Receptor Tipo 1 de Angiotensina II/uso terapêutico , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , HDL-Colesterol/sangue , Falência Renal Crônica/terapia , Ramipril/uso terapêutico , Diálise Renal , Valsartana/uso terapêutico , Adulto , Bloqueadores do Receptor Tipo 1 de Angiotensina II/efeitos adversos , Inibidores da Enzima Conversora de Angiotensina/efeitos adversos , Biomarcadores/sangue , Método Duplo-Cego , Feminino , Humanos , Mediadores da Inflamação/sangue , Falência Renal Crônica/sangue , Falência Renal Crônica/diagnóstico , Masculino , Pessoa de Meia-Idade , Estresse Oxidativo/efeitos dos fármacos , Ramipril/efeitos adversos , Diálise Renal/efeitos adversos , Tennessee , Fatores de Tempo , Resultado do Tratamento , Valsartana/efeitos adversos
3.
Clin Genet ; 89(1): 115-9, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25810209

RESUMO

Wiedemann-Steiner syndrome (WSS) is an autosomal dominant congenital anomaly syndrome characterized by hairy elbows, dysmorphic facial appearances (hypertelorism, thick eyebrows, downslanted and vertically narrow palpebral fissures), pre- and post-natal growth deficiency, and psychomotor delay. WSS is caused by heterozygous mutations in KMT2A (also known as MLL), a gene encoding a histone methyltransferase. Here, we identify six novel KMT2A mutations in six WSS patients, with four mutations occurring de novo. Interestingly, some of the patients were initially diagnosed with atypical Kabuki syndrome, which is caused by mutations in KMT2D or KDM6A, genes also involved in histone methylation. KMT2A mutations and clinical features are summarized in our six patients together with eight previously reported patients. Furthermore, clinical comparison of the two syndromes is discussed in detail.


Assuntos
Anormalidades Múltiplas/diagnóstico , Anormalidades Múltiplas/genética , Histona-Lisina N-Metiltransferase/genética , Mutação , Proteína de Leucina Linfoide-Mieloide/genética , Fenótipo , Criança , Pré-Escolar , Exoma , Feminino , Loci Gênicos , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Masculino
6.
Cancer Chemother Pharmacol ; 73(2): 259-70, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24253175

RESUMO

PURPOSE: Angiosarcomas are rare, aggressive vascular tumours known to express vascular endothelial growth factor (VEGF), a key pro-angiogenic growth factor. The aim of this study was to determine the potential effects of vascular-targeted agents for the treatment of angiosarcoma, using two human cutaneous angiosarcoma cell lines (ASM and ISO-HAS), and human dermal microvascular endothelial cells (HuDMECs) for comparison. METHODS: Protein arrays were used to assess the expression of angiogenesis-related proteins, and potential drug targets were assessed by ELISA and Western blotting. Response to vascular-targeted agents, including bevacizumab an anti-VEGF antibody, axitinib a VEGF-receptor tyrosine kinase inhibitor, everolimus an mTOR inhibitor, selumetinib a MEK inhibitor and vadimezan a vascular-disrupting agent were compared in functional in vitro cellular assays, including viability, differentiation and migration assays. RESULTS: ASM and ISO-HAS cells expressed a broad range of pro-angiogenic growth factors. ASM and ISO-HAS VEGF expression was significantly increased (p = 0.029) compared with HuDMECs. Striking responses were seen to vadimezan with an IC50 of 90 and 150 µg/ml for ASM and ISO-HAS cells, respectively. Selumetinib inhibited ASM with an IC50 of 1,750 ng/ml, but was not effective in ISO-HAS. Everolimus reduced both ASM and ISO-HAS viable cell counts by 20 % (p < 0.001). Minimal responses were observed to bevacizumab and axitinib in assays with ASM and ISO-HAS cells. CONCLUSIONS: Further studies are warranted to investigate mTOR inhibitors, MEK inhibitors and vascular-disrupting agents for the treatment of angiosarcoma.


Assuntos
Inibidores da Angiogênese/farmacologia , Hemangiossarcoma/irrigação sanguínea , Hemangiossarcoma/tratamento farmacológico , Anticorpos Monoclonais Humanizados/farmacologia , Axitinibe , Bevacizumab , Morte Celular/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Doxorrubicina/farmacologia , Everolimo , Hemangiossarcoma/metabolismo , Hemangiossarcoma/patologia , Humanos , Imidazóis/farmacologia , Indazóis/farmacologia , Neovascularização Patológica/tratamento farmacológico , Neovascularização Patológica/metabolismo , Neovascularização Patológica/patologia , Paclitaxel/farmacologia , Análise Serial de Proteínas , Sirolimo/análogos & derivados , Sirolimo/farmacologia , Fator A de Crescimento do Endotélio Vascular/antagonistas & inibidores , Fator A de Crescimento do Endotélio Vascular/metabolismo
7.
Chem Commun (Camb) ; 49(94): 11074-6, 2013 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-24141490

RESUMO

Colloidal solutions of ZnO-Cu nanoparticles can be used as catalysts for the reduction of carbon dioxide with hydrogen. The use of phosphinate ligands for the synthesis of the nanoparticles from organometallic precursors improves the reductive stability and catalytic activity of the system.

8.
Clin Pharmacol Ther ; 93(4): 326-34, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23361105

RESUMO

Bradykinin increases during cardiopulmonary bypass (CPB) and stimulates the release of nitric oxide, inflammatory cytokines, and tissue-type plasminogen activator (t-PA), acting through its B2 receptor. This study tested the hypothesis that endogenous bradykinin contributes to the fibrinolytic and inflammatory response to CPB and that bradykinin B2 receptor antagonism reduces fibrinolysis, inflammation, and subsequent transfusion requirements. Patients (N = 115) were prospectively randomized to placebo, ε-aminocaproic acid (EACA), or HOE 140, a bradykinin B2 receptor antagonist. Bradykinin B2 receptor antagonism decreased intraoperative fibrinolytic capacity as much as EACA, but only EACA decreased D-dimer formation and tended to decrease postoperative bleeding. Although EACA and HOE 140 decreased fibrinolysis and EACA attenuated blood loss, these treatments did not reduce the proportion of patients transfused. These data suggest that endogenous bradykinin contributes to t-PA generation in patients undergoing CPB, but that additional effects on plasmin generation contribute to decreased D-dimer concentrations during EACA treatment.


Assuntos
Ácido Aminocaproico/uso terapêutico , Transfusão de Sangue/estatística & dados numéricos , Antagonistas dos Receptores da Bradicinina , Bradicinina/análogos & derivados , Bradicinina/fisiologia , Ponte Cardiopulmonar/efeitos adversos , Fibrinólise/fisiologia , Inflamação/tratamento farmacológico , Antifibrinolíticos/uso terapêutico , Bradicinina/antagonistas & inibidores , Bradicinina/uso terapêutico , Feminino , Produtos de Degradação da Fibrina e do Fibrinogênio/metabolismo , Fibrinólise/efeitos dos fármacos , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias , Hemorragia Pós-Operatória/tratamento farmacológico
9.
J Hum Hypertens ; 27(3): 176-80, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22648267

RESUMO

Serum- and glucocorticoid-inducible kinase 1 (SGK1) has a central role in epithelial sodium channel (ENaC)-dependent Na(+) transport in the distal nephron. We hypothesized that SGK1 gene variants may contribute to the effect of dietary salt intake on blood pressure (BP) in humans with hypertension, and consequentially influence renin-angiotensin-aldosterone (RAA) system activity. Our study population included 421 hypertensive Caucasian participants of the HyperPath group who had completed a dietary salt protocol with measurement of BP and RAA system activity. Three SGK1 tagging single nucleotide polymorphisms (SNPs) from the HapMap CEU population captured the genetic variation in the SGK1 region. Assuming an additive genetic model, two SNPs (rs2758151 and rs9402571) were associated with BP and plasma renin activity (PRA) effects of dietary salt intake. Major alleles were associated with higher systolic BP on high salt and decreased PRA on low salt. In contrast, low salt neutralized genotype differences. Similar, non-significant trends were observed in a normotensive population (N=152). Genotype was also associated with two salt-sensitive subtypes of hypertension. SGK1 genetic variants are associated with salt sensitivity of BP and PRA in human hypertension. Genotype status at these SGK1 variants may identify individuals prone to salt-sensitive hypertension.


Assuntos
Pressão Sanguínea/genética , Hipertensão/genética , Proteínas Imediatamente Precoces/genética , Polimorfismo de Nucleotídeo Único , Proteínas Serina-Treonina Quinases/genética , Cloreto de Sódio na Dieta/administração & dosagem , Adulto , Biomarcadores/sangue , Distribuição de Qui-Quadrado , Europa (Continente)/epidemiologia , Feminino , Frequência do Gene , Predisposição Genética para Doença , Humanos , Hipertensão/sangue , Hipertensão/enzimologia , Hipertensão/etnologia , Hipertensão/fisiopatologia , Modelos Lineares , Desequilíbrio de Ligação , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Fenótipo , Renina/sangue , Sistema Renina-Angiotensina , Cloreto de Sódio na Dieta/efeitos adversos , Estados Unidos/epidemiologia , População Branca/genética
10.
Pharmacogenomics J ; 13(1): 44-51, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21912424

RESUMO

The ω-hydroxylase CYP4A11 catalyzes the transformation of epoxyeicosatrienoic acids (EETs) to ω-hydroxylated EETs, endogenous peroxisome proliferator-activated receptor-α (PPARα) agonists. PPARα activation increases high-density lipoprotein cholesterol (HDL-C). A cytosine-for-thymidine (T8590C) variant of CYP4A11 encodes for an ω-hydroxylase with reduced activity. This study examined the relationship between CYP4A11 T8590C genotype and metabolic parameters in the Framingham Offspring Study and in a clinical practice-based biobank, BioVU. In women in the Framingham Offspring Study, the CYP4A11 8590C allele was associated with reduced HDL-C concentrations (52.1±0.5 mg dl(-1) in CYP4A11 CC- or CT-genotype women versus 54.8±0.5 mg dl(-1) in TT women at visit 2, P=0.02), and with an increased prevalence of low HDL-C, defined categorically as 50 mg dl(-1) (odds ratio 1.39 (95% CI 1.02-1.90), P=0.04). In the BioVU cohort, the CYP4A11 8590C allele was also associated with low HDL-C in women (odds ratio 1.69 (95% CI 1.03-2.77, P=0.04)). There was no relationship between genotype and HDL-C in men in either cohort.


Assuntos
HDL-Colesterol/genética , HDL-Colesterol/metabolismo , Sistema Enzimático do Citocromo P-450/genética , Sistema Enzimático do Citocromo P-450/metabolismo , Adulto , Alelos , Estudos de Coortes , Citocromo P-450 CYP4A/genética , Citocromo P-450 CYP4A/metabolismo , Feminino , Variação Genética , Genótipo , Humanos , Masculino
11.
Clin Pharmacol Ther ; 91(6): 1065-73, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22549281

RESUMO

The effects of angiotensin-converting enzyme (ACE) inhibition and angiotensin II type 1 receptor blockade (ARB) on fibrinolysis and inflammation after cardiopulmonary bypass (CPB) are uncertain. This study tested the hypothesis that ACE inhibition enhances fibrinolysis and inflammation to a greater extent than ARB in patients undergoing CPB. One week to 5 days before surgery, patients were randomized to ramipril 5 mg/day, candesartan 16 mg/day, or placebo. ACE inhibition increased intraoperative bradykinin and tissue-type plasminogen activator (t-PA ) concentrations as compared to AR B. Both ACE inhibition and AR B decreased the need for plasma transfusion relative to placebo, but only ACE inhibition decreased the duration of hospital stay. Neither ACE inhibition nor AR B significantly affected concentrations of plasminogen activator inhibitor-1 (PAI -1), interleukin (IL )-6, IL -8, or IL -10. ACE inhibition enhanced intraoperative fibrinolysis without increasing the likelihood of red-cell transfusion. By contrast, neither ACE inhibition nor ARB affected the inflammatory response. ACE inhibitors and ARBs may be safely continued until the day of surgery.


Assuntos
Bloqueadores do Receptor Tipo 1 de Angiotensina II/uso terapêutico , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Benzimidazóis/uso terapêutico , Ponte Cardiopulmonar/efeitos adversos , Fibrinólise/efeitos dos fármacos , Inflamação/tratamento farmacológico , Ramipril/uso terapêutico , Tetrazóis/uso terapêutico , Idoso , Compostos de Bifenilo , Transfusão de Sangue , Bradicinina/metabolismo , Determinação de Ponto Final , Feminino , Hematócrito , Mortalidade Hospitalar , Humanos , Inflamação/etiologia , Interleucinas/metabolismo , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Monitorização Intraoperatória , Assistência Perioperatória , Complicações Pós-Operatórias/epidemiologia , Resultado do Tratamento
12.
Br J Anaesth ; 108(6): 929-35, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22511481

RESUMO

BACKGROUND: Propofol acts as an L-type calcium channel (LTCC) antagonist to decrease peripheral resistance and initiate hypotension. This study investigated LTCC sensitivity/expression in hypertension and the role of LTCCs in exaggerated hypotension to propofol in this situation. METHODS: Age-matched 12- to 15-week-old normotensive rats [male Wistar Kyoto (WKY)] and spontaneously hypertensive rats (SHR) were used. Propofol (10 mg kg(-1), 10-50 mg kg(-1) h(-1) i.v.) was administered and the mesenteric microcirculation (<70 µm) observed with fluorescent in vivo microscopy using fluorescein isothiocyanate-conjugated bovine serum albumin (100 mg kg(-1) i.v.). Western blotting was used to measure tissue expression of the α(1C) LTCC subtype. Pressure myography was used to assess isolated mesenteric arterioles (<350 µm) in response to BAYK8644 (0.1 nM-1 µM), a specific LTCC channel agonist. RESULTS: Propofol dilated isolated arterioles {336.6 µM [mean (sd) change 16.2 (5.8)%]}. However, constriction to BAYK8644 was reduced at this concentration of propofol [EC(50)=8.3 (0.1) log mol(-1)] compared with controls [7.4 (0.1) log mol(-1), P<0.05], suggesting that propofol inhibited LTCCs. The sensitivity of LTCCs increased during hypertension, as in vivo there was a greater increase in mean arterial pressure (MAP) to BAYK8644 [10 µg kg(-1), WKY: 59.5 (9.3)%; SHR: 97.7 (6.3)%, P<0.05] with exaggerated constriction of arterioles [10 µg kg(-1), WKY: 9.1 (2.5)%; SHR: 19.1 (2.6)%, P<0.05]. Propofol also decreased MAP in SHR over time (P<0.05), but remained unchanged in WKY. Using western blotting, expression of α(1C) was greater in SHR compared with WKY (P<0.05). CONCLUSIONS: Propofol acts via LTCC channels, with increased channel expression and sensitivity in genetically hypertensive rats. We suggest that increased sensitivity and expression of LTCCs may be a mechanism for exaggerated hypertension during propofol anaesthesia.


Assuntos
Anestésicos Intravenosos/farmacologia , Bloqueadores dos Canais de Cálcio/farmacologia , Canais de Cálcio Tipo L/fisiologia , Hipertensão/fisiopatologia , Microvasos/efeitos dos fármacos , Propofol/farmacologia , Éster Metílico do Ácido 3-Piridinacarboxílico, 1,4-Di-Hidro-2,6-Dimetil-5-Nitro-4-(2-(Trifluormetil)fenil)/farmacologia , Animais , Pressão Sanguínea/efeitos dos fármacos , Canais de Cálcio Tipo L/efeitos dos fármacos , Relação Dose-Resposta a Droga , Masculino , Microvasos/fisiologia , Ratos , Ratos Endogâmicos SHR , Ratos Endogâmicos WKY , Circulação Esplâncnica/efeitos dos fármacos
13.
Br J Cancer ; 106(6): 1153-9, 2012 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-22353811

RESUMO

BACKGROUND: Thalidomide has potent anti-inflammatory and anti-angiogenic properties. It was evaluated in combination with chemotherapy in two randomised placebo-controlled trials in patients with small cell lung cancer (SCLC, n=724) and advanced non-small cell lung cancer (NSCLC, n=722). Neither study demonstrated an improvement in overall survival with the addition of thalidomide to chemotherapy. This study investigated circulating angiogenic biomarkers in a subset of these patients. METHODS: Serial plasma samples were collected in a cohort of patients enrolled in these two trials (n=95). Vascular endothelial growth factor (VEGF), soluble truncated form of VEGF receptor-2 (sVEGFR-2), interleukin-8 (IL-8), tumour necrosis factor-α (TNF-α), basic fibroblast growth factor (bFGF) and soluble intercellular adhesion molecule-1 (sICAM-1) levels were measured by enzyme-linked immunosorbent assays. Results were correlated with patient clinical data including stage, response rate and progression-free survival (PFS). RESULTS: Baseline biomarker levels were not significantly different between SCLC and NSCLC. For pooled treatment groups, limited stage SCLC was associated with lower baseline VEGF (P=0.046), sICAM-1 (P=0.008) and IL-8 (P=0.070) than extensive stage disease. Low baseline IL-8 was associated with a significantly improved PFS in both SCLC and NSCLC (P=0.028), and a greater reduction in IL-8 was associated with a significantly improved tumour response (P=0.035). Baseline angiogenic factor levels, however, did not predict response to thalidomide. CONCLUSION: Circulating angiogenic biomarkers did not identify patients who benefited from thalidomide treatment.


Assuntos
Inibidores da Angiogênese/uso terapêutico , Biomarcadores Tumorais/sangue , Carcinoma Pulmonar de Células não Pequenas/sangue , Neoplasias Pulmonares/sangue , Neovascularização Patológica/sangue , Carcinoma de Pequenas Células do Pulmão/sangue , Talidomida/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carboplatina/administração & dosagem , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/mortalidade , Ensaios Clínicos Fase III como Assunto , Desoxicitidina/administração & dosagem , Desoxicitidina/análogos & derivados , Etoposídeo/administração & dosagem , Feminino , Fator 2 de Crescimento de Fibroblastos/sangue , Humanos , Molécula 1 de Adesão Intercelular/sangue , Interleucina-8/sangue , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/mortalidade , Masculino , Pessoa de Meia-Idade , Estudos Multicêntricos como Assunto , Análise Multivariada , Neovascularização Patológica/tratamento farmacológico , Neovascularização Patológica/mortalidade , Modelos de Riscos Proporcionais , Ensaios Clínicos Controlados Aleatórios como Assunto , Carcinoma de Pequenas Células do Pulmão/tratamento farmacológico , Carcinoma de Pequenas Células do Pulmão/mortalidade , Análise de Sobrevida , Resultado do Tratamento , Fator A de Crescimento do Endotélio Vascular/sangue , Gencitabina
14.
Diabetologia ; 54(8): 2152-63, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21519965

RESUMO

AIMS/HYPOTHESIS: Aldosterone concentrations increase in obesity and predict the onset of diabetes. We investigated the effects of aldosterone on glucose homeostasis and insulin secretion in vivo and in vitro. METHODS: We assessed insulin sensitivity and insulin secretion in aldosterone synthase-deficient (As [also known as Cyp11b2](-/-)) and wild-type mice using euglycaemic-hyperinsulinaemic and hyperglycaemic clamps, respectively. We also conducted studies during high sodium intake to normalise renin activity and potassium concentration in As (-/-) mice. We subsequently assessed the effect of aldosterone on insulin secretion in vitro in the presence or absence of mineralocorticoid receptor antagonists in isolated C57BL/6J islets and in the MIN6 beta cell line. RESULTS: Fasting glucose concentrations were reduced in As (-/-) mice compared with wild-type. During hyperglycaemic clamps, insulin and C-peptide concentrations increased to a greater extent in As (-/-) than in wild-type mice. This was not attributable to differences in potassium or angiotensin II, as glucose-stimulated insulin secretion was enhanced in As (-/-) mice even during high sodium intake. There was no difference in insulin sensitivity between As (-/-) and wild-type mice in euglycaemic-hyperinsulinaemic clamp studies. In islet and MIN6 beta cell studies, aldosterone inhibited glucose- and isobutylmethylxanthine-stimulated insulin secretion, an effect that was not blocked by mineralocorticoid receptor antagonism, but was prevented by the superoxide dismutase mimetic tempol. CONCLUSIONS/INTERPRETATION: We demonstrated that aldosterone deficiency or excess modulates insulin secretion in vivo and in vitro via reactive oxygen species and in a manner that is independent of mineralocorticoid receptors. These findings provide insight into the mechanism of glucose intolerance in conditions of relative aldosterone excess.


Assuntos
Aldosterona/metabolismo , Aldosterona/farmacologia , Glucose/farmacologia , Insulina/metabolismo , Ilhotas Pancreáticas/efeitos dos fármacos , Ilhotas Pancreáticas/metabolismo , Animais , Glicemia/efeitos dos fármacos , Linhagem Celular , Citocromo P-450 CYP11B2/deficiência , Citocromo P-450 CYP11B2/genética , Técnicas In Vitro , Secreção de Insulina , Células Secretoras de Insulina/efeitos dos fármacos , Células Secretoras de Insulina/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL
16.
Breast Cancer Res Treat ; 128(3): 691-701, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20830515

RESUMO

In breast cancer, there is a correlation between tissue factor (TF) expression, angiogenesis and disease progression. TF stimulates tumour angiogenesis, in part, through up-regulation of vascular endothelial growth factor (VEGF). Therefore, this study aimed to establish whether TF stimulates angiogenesis and tumour progression directly and independent of VEGF up-regulation. Initially, the effects of TF and VEGF were assessed on endothelial cell migration (Boyden chamber) and differentiation (tubule formation on Matrigel). Subsequently, MDA-MB-436 breast cancer cells, which produce high levels of both TF and VEGF (western blot analysis), were established in vivo, following which tumours were treated three times per week for 3 weeks with intra-tumoural injections of either anti-VEGF siRNA, anti-TF shRNA, the two treatments combined, or relevant controls. Both VEGF and TF significantly stimulated endothelial cell migration and tubule formation (P < 0.02). Breast cancer xenografts (MDA-MB-436) treated with TF or VEGF-specific agents demonstrated significant inhibition in tumour growth (VEGFsiRNA 61%; final volume: 236.2 ± 23.2 mm(3) vs TFshRNA 89%; 161.9 ± 17.4 mm(3) vs combination 93%; 136.3 ± 9.2 mm(3) vs control 400.4 ± 32.7 mm(3); P < 0.005). Microvessel density (MVD), a measure of angiogenesis, was also significantly inhibited in all groups (MVD in control = 29 ± 2.9; TFshRNA = 18 ± 1.1; VEGFsiRNA = 16.7 ± 1.5; both = 12 ± 2.1; P < 0.004), whereas the proliferative index of the tumours was only reduced in the TFshRNA-treated groups (control = 0.51 ± 0.011; TFshRNA = 0.41 ± 0.014; VEGFsiRNA = 0.49 ± 0.013; both = 0.41 ± 0.004; P < 0.008). These data suggest that TF has a direct effect on primary breast cancer growth and angiogenesis, and that specific inhibition of the TF-signalling pathway has potential for the treatment of primary breast cancer.


Assuntos
Neoplasias da Mama/metabolismo , RNA Interferente Pequeno/metabolismo , Tromboplastina/metabolismo , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Movimento Celular/genética , Células Endoteliais/metabolismo , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , RNA Interferente Pequeno/genética , Tromboplastina/genética , Carga Tumoral/genética , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/metabolismo
17.
J Photochem Photobiol B ; 101(3): 224-32, 2010 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-20724176

RESUMO

Photodynamic therapy (PDT) is a local cancer treatment which induces cell death by the interaction of light with a photosensitizing drug. Previous studies indicate that nitric oxide (NO) plays a role in Photofrin-PDT, but this has not been investigated in aminolaevulinic acid (ALA)-PDT. The current study determines whether inhibition of nitric oxide synthase (NOS) activity modulates treatment responses to ALA-PDT, in tumours displaying differential levels of NO. Murine tumours with low (EMT6) or high (RIF-1) NO levels were implanted into the cremaster muscle of BALB/c or C3H/HeN mice respectively. Animals were prepared for in vivo microscopy 7-14days later. Mice received oral ALA (200mg/kg) 4h before PDT. l-NAME, l-NNA or 1400W (10mg/kg) were administered via the jugular vein 5min before PDT. NOS inhibition (l-NAME or l-NNA) combined with ALA-PDT in RIF-1 tumours demonstrated enhanced damage to both the tumour and normal microvasculature, with increased macromolecular leak and reduction in vessel diameter, whereas ALA-PDT alone had no effect. In contrast, EMT6 tumours responded to ALA-PDT alone but sensitivity was not enhanced in the presence of NOS inhibition. 1400 W combined with ALA-PDT induced similar microvascular effects to l-NAME in both tumours, but were less pronounced. The data demonstrates that NO has an important role in events likely to be critical for treatment response, sensitivity and therapeutic outcome of ALA-PDT.


Assuntos
Ácido Aminolevulínico/uso terapêutico , Neoplasias Experimentais/tratamento farmacológico , Óxido Nítrico/fisiologia , Fotoquimioterapia , Fármacos Fotossensibilizantes/uso terapêutico , Administração Oral , Animais , Linhagem Celular Tumoral , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C3H , NG-Nitroarginina Metil Éster/farmacologia , Neoplasias Experimentais/patologia , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo II/antagonistas & inibidores , Óxido Nítrico Sintase Tipo II/metabolismo , Nitroarginina/farmacologia , Protoporfirinas/metabolismo
18.
Br J Dermatol ; 163(5): 920-7, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20633009

RESUMO

BACKGROUND: The angiopoietin (Ang)/Tie-2 ligand/receptor system is known to interact with the vascular endothelial growth factor (VEGF) pathway to determine the fate of blood vessels during angiogenesis. However, the precise contribution of this system to angiogenesis and the mechanisms of vascular maturation and remodelling in human tissue repair have yet to be elucidated. OBJECTIVES: To examine the spatial and temporal expression of Ang-1, Ang-2, Tie-2 and VEGF in relation to angiogenesis in human surgical wounds. METHODS: Punch biopsies were taken either from normal unwounded skin (controls) during surgery or from mastectomy scars between 3 days and 2 years postsurgery. Ang-1, Ang-2, Tie-2 and VEGF fibroblast/myofibroblast and endothelial expression were characterized by immunohistochemistry, analysed semiquantitatively and correlated with microvessel density (MVD) and scar age. RESULTS: The expression of VEGF, Ang-1, Ang-2 and Tie-2 in fibroblasts/myofibroblasts was increased significantly in early scars, decreased in older scars and was related to scar age (P < 0·001) and MVD (P < 0·0004), with strong correlations between all factors. In contrast, vascular expression of Ang-1 was decreased slightly in early scars, vascular Ang-2 remained constant and Tie-2 vascular expression increased, although there were no correlations with scar age or MVD. CONCLUSIONS: These data demonstrate that angiopoietins and their receptor, Tie-2, are expressed in both fibroblasts/myofibroblasts and endothelial cells in healing human wounds. Fibroblast/myofibroblast expression correlates with angiogenesis and VEGF expression, suggesting a role for the angiopoietin/Tie-2 system in normal wound repair and scarring.


Assuntos
Angiopoietina-1/metabolismo , Angiopoietina-2/metabolismo , Cicatriz/metabolismo , Neovascularização Fisiológica/fisiologia , Receptor TIE-2/metabolismo , Pele/metabolismo , Cicatrização/fisiologia , Biópsia , Cicatriz/patologia , Células Endoteliais/metabolismo , Feminino , Fibroblastos/metabolismo , Humanos , Imuno-Histoquímica , Miofibroblastos/metabolismo , Pele/patologia , Fator A de Crescimento do Endotélio Vascular/metabolismo
19.
Allergy ; 65(11): 1381-7, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20557296

RESUMO

BACKGROUND: Immunosuppressants decrease circulating dipeptidyl peptidase IV (DPPIV) activity in transplant patients, and decreased DPPIV activity has been associated with angiotensin-converting enzyme (ACE) inhibitor-associated angioedema. One study has reported an increased incidence of ACE inhibitor-associated angioedema among transplant patients compared to published rates, while several case series report angioedema in patients taking specific immunosuppressant agents. OBJECTIVE: To test the hypothesis that transplant patients are at increased risk of ACE inhibitor-associated angioedema. METHODS: We assessed the proportion of transplant patients in 145 cases with ACE inhibitor-associated angioedema and 280 ACE inhibitor-exposed controls. We measured the relationship between case-control status, transplant status, and immunosuppressant use and circulating DPPIV activity. We also assessed the incidence of angioedema among consecutive patients who underwent renal or cardiac transplant and were treated with an ACE inhibitor. RESULTS: Transplant patients were significantly overrepresented among ACE inhibitor-associated angioedema cases compared to controls (odds ratio 18.5, 95% CI 2.3-147.2, P = 0.0004). Immunosuppressant use, chronic renal failure, seasonal allergies and smoking were also associated with ACE inhibitor-associated angioedema in univariate analysis. The association of transplant status with ACE inhibitor-associated angioedema was no longer significant after inclusion of immunosuppressant therapy in a multivariate analysis. Dipeptidyl peptidase IV activity was significantly decreased in sera from cases compared to ACE inhibitor-exposed controls, as well as in individuals taking immunosuppressants. Two of 47 ACE inhibitor-treated renal transplant patients and one of 36 ACE inhibitor-treated cardiac transplant patients developed angioedema. CONCLUSION: Transplant patients are at increased risk of ACE inhibitor-associated angioedema possibly because of the effects of immunosuppressants on the activity of DPPIV.


Assuntos
Angioedema/induzido quimicamente , Angioedema/epidemiologia , Inibidores da Enzima Conversora de Angiotensina/efeitos adversos , Dipeptidil Peptidase 4/metabolismo , Imunossupressores/efeitos adversos , Transplante de Órgãos , Angioedema/enzimologia , Estudos de Casos e Controles , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/enzimologia , Feminino , Humanos , Hospedeiro Imunocomprometido , Masculino , Pessoa de Meia-Idade , Transplante de Órgãos/estatística & dados numéricos , Fatores de Risco
20.
Br J Anaesth ; 104(2): 183-90, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20086063

RESUMO

BACKGROUND: Sepsis induces microvascular inflammation and production of the vasodilator nitric oxide (NO) via endothelial and inducible nitric oxide synthase (eNOS or NOS III and iNOS or NOS II). Statins are cholesterol-lowering drugs; however, they also attenuate inflammation. This study aimed to determine whether pravastatin protected against sepsis-induced hypotension, loss of vascular tone, and microvascular inflammation via NOS pathways. METHODS: Male Wistar rats (n=18) were anaesthetized and the mesentery prepared for fluorescent intravital microscopy. Animals received either lipopolysaccharide (LPS; n=6); LPS+pravastatin (18 and 3 h before LPS; n=6), or saline as a control, for 4 h. RESULTS: Mean arterial pressure decreased in LPS-treated animals (P<0.05), but not in those also receiving pravastatin. Acetylcholine-induced relaxation of venules was abolished by LPS but improved by pravastatin. Pravastatin also reduced the increase in nitrite concentration and macromolecular leak from venules induced by LPS (P<0.05). The increased leucocyte adhesion seen in LPS-treated rats was also reduced in those also treated with pravastatin. Immunohistochemical analysis showed that pravastatin increased endothelial cell expression of NOS III during sepsis, but had no effect on LPS-induced up-regulation of NOS II. CONCLUSIONS: Pravastatin improved NOS III-mediated vessel relaxation and exerted anti-inflammatory effects within the microcirculation after LPS administration in rats. Pravastatin therefore appears to have beneficial effects during sepsis, as a result of increased microvascular expression and function of NOS III.


Assuntos
Anti-Inflamatórios não Esteroides/uso terapêutico , Endotoxemia/complicações , Óxido Nítrico Sintase Tipo III/fisiologia , Pravastatina/uso terapêutico , Vasculite/prevenção & controle , Animais , Pressão Sanguínea/efeitos dos fármacos , Permeabilidade Capilar/efeitos dos fármacos , Adesão Celular/efeitos dos fármacos , Avaliação Pré-Clínica de Medicamentos/métodos , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/fisiopatologia , Endotoxemia/fisiopatologia , Leucócitos/enzimologia , Leucócitos/fisiologia , Lipopolissacarídeos , Masculino , Microcirculação/efeitos dos fármacos , Ratos , Ratos Wistar , Vasculite/etiologia , Vasculite/fisiopatologia
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