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1.
Rev. esp. cardiol. (Ed. impr.) ; 77(2): 150-175, feb. 2024.
Artigo em Espanhol | IBECS | ID: ibc-230483

RESUMO

Introduction and objectives The optimal antithrombotic strategy following left atrial appendage closure (LAAC) is poorly defined in patients with nonvalvular atrial fibrillation. We assessed the safety and effectiveness of a single antiplatelet treatment (SAPT) strategy after LAAC in a population at high risk of ischemic and bleeding events. Methods This single-center, observational, prospective study included a consecutive cohort of patients who underwent LAAC using the LAmbre device (Lifetech Scientific, China) and who were discharged with SAPT. The primary outcome was a composite of stroke, systemic embolism, and device-related thrombosis during follow-up. Secondary endpoints were cardiovascular mortality and major bleeding events (BARC ≥3a). Clinical follow-up was performed at 1, 6, and 12 months and subsequently on an annual basis. Transesophageal echocardiography was performed at 1 and 12 months of follow-up. Results The study comprised 74 patients. The median age was 77 [72-83] years and 43% were women. The cohort exhibited a high prevalence of comorbidities and cardiovascular risk factors. The median CHA2DS2-VASc and HAS-BLED scores were 4 [3-6] and 4 [4-5], respectively. The median length of follow-up was 2.5 years (188 patients-year). During follow-up, device-related thrombosis occurred in 3 patients (4%). Ischemic stroke occurred in 1 patient (1.3%, rate 0.5%/y), representing a 90.9% relative risk reduction compared with the risk predicted by CHA2DS2-VASc. Major bleeding events occurred in 12 patients (16%, 6.4%/y), with a relative risk reduction of 26.4% of that predicted by HAS-BLED. Cardiovascular-related mortality was observed in 2 patients (2.7%). Conclusions SAPT appears to be a safe and effective treatment following LAAC in patients at high ischemic and hemorrhagic risk. Further studies are needed to confirm our findings (AU)


Introducción y objetivos Se desconoce cuál es la terapia antitrombótica óptima tras el cierre percutáneo de la orejuela izquierda (CPOI) en pacientes con fibrilación auricular no valvular. El objetivo de este estudio es analizar la efectividad y la seguridad de un régimen de tratamiento antiagregante plaquetario simple (TAPS) tras el CPOI en una población con alto riesgo isquémico y hemorrágico. Métodos Estudio observacional prospectivo que incluyó una cohorte consecutiva de pacientes a los que se realizó CPOI con dispositivo LAmbre (Lifetech Scientific, China) y que recibieron TAPS al alta. El evento primario fue un combinado de ictus, embolia sistémica y trombosis del dispositivo. Los eventos secundarios fueron mortalidad cardiovascular y hemorragia mayor (BARC ≥ 3a). Se realizó seguimiento clínico al mes y a los 6 y 12 meses y cada año después. Se realizó ecocardiograma transesofágico al mes y a los 12 meses. Resultados Se incluyó a 74 pacientes (el 43% mujeres) con una mediana de edad de 77 [intervalo intercuartílico, 72-83] años, que presentaban gran comorbilidad y factores de riesgo cardiovascular. Los valores de CHA2DS2-VASc y HAS-BLED fueron una mediana de 4 [3-6] y 4 [4-5] respectivamente. Durante el seguimiento (mediana, 2,5 años), 3 pacientes (4%) presentaron trombosis del dispositivo. Uno sufrió ictus isquémico (1,3%, 0,5%/año), lo que supone, según la incidencia esperada por CHA2DS2-VASc, una reducción del riesgo relativo del 90,9%. Sufrieron eventos hemorrágicos 12 pacientes (16%; 6,4%/año), una tasa el 26,4% menor que el riesgo HAS-BLED predicho. Se produjo la muerte cardiovascular de 2 pacientes (2,7%). Conclusiones Una estrategia de TAPS tras el CPOI parece ser una opción efectiva y segura para los pacientes con altos riesgos isquémico y hemorrágico. Se necesitan más estudios que corroboren nuestros resultados (AU)


Assuntos
Idoso , Idoso de 80 Anos ou mais , Fibrilação Atrial/tratamento farmacológico , Fibrilação Atrial/cirurgia , Inibidores da Agregação Plaquetária , Inibidores da Agregação Plaquetária/uso terapêutico , Apêndice Atrial/diagnóstico por imagem , Apêndice Atrial/cirurgia , Hemorragia , Estudos Prospectivos , Resultado do Tratamento
2.
Mol Oncol ; 2024 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-38214418

RESUMO

Metformin and IACS-010759 are two distinct antimetabolic agents. Metformin, an established antidiabetic drug, mildly inhibits mitochondrial complex I, while IACS-010759 is a new potent mitochondrial complex I inhibitor. Mitochondria is pivotal in the energy metabolism of cells by providing adenosine triphosphate through oxidative phosphorylation (OXPHOS). Hence, mitochondrial metabolism and OXPHOS become a vulnerability when targeted in cancer cells. Both drugs have promising antitumoral effects in diverse cancers, supported by preclinical in vitro and in vivo studies. We present evidence of their direct impact on cancer cells and their immunomodulatory effects. In clinical studies, while observational epidemiologic studies on metformin were encouraging, actual trial results were not as expected. However, IACS-01075 exhibited major adverse effects, thereby causing a metabolic shift to glycolysis and elevated lactic acid concentrations. Therefore, the future outlook for these two drugs depends on preventive clinical trials for metformin and investigations into the plausible toxic effects on normal cells for IACS-01075.

3.
Rev Esp Cardiol (Engl Ed) ; 77(2): 150-157, 2024 Feb.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-37879431

RESUMO

INTRODUCTION AND OBJECTIVES: The optimal antithrombotic strategy following left atrial appendage closure (LAAC) is poorly defined in patients with nonvalvular atrial fibrillation. We assessed the safety and effectiveness of a single antiplatelet treatment (SAPT) strategy after LAAC in a population at high risk of ischemic and bleeding events. METHODS: This single-center, observational, prospective study included a consecutive cohort of patients who underwent LAAC using the LAmbre device (Lifetech Scientific, China) and who were discharged with SAPT. The primary outcome was a composite of stroke, systemic embolism, and device-related thrombosis during follow-up. Secondary endpoints were cardiovascular mortality and major bleeding events (BARC ≥3a). Clinical follow-up was performed at 1, 6, and 12 months and subsequently on an annual basis. Transesophageal echocardiography was performed at 1 and 12 months of follow-up. RESULTS: The study comprised 74 patients. The median age was 77 [72-83] years and 43% were women. The cohort exhibited a high prevalence of comorbidities and cardiovascular risk factors. The median CHA2DS2-VASc and HAS-BLED scores were 4 [3-6] and 4 [4-5], respectively. The median length of follow-up was 2.5 years (188 patients-year). During follow-up, device-related thrombosis occurred in 3 patients (4%). Ischemic stroke occurred in 1 patient (1.3%, rate 0.5%/y), representing a 90.9% relative risk reduction compared with the risk predicted by CHA2DS2-VASc. Major bleeding events occurred in 12 patients (16%, 6.4%/y), with a relative risk reduction of 26.4% of that predicted by HAS-BLED. Cardiovascular-related mortality was observed in 2 patients (2.7%). CONCLUSIONS: SAPT appears to be a safe and effective treatment following LAAC in patients at high ischemic and hemorrhagic risk. Further studies are needed to confirm our findings.


Assuntos
Fibrilação Atrial , Oclusão do Apêndice Atrial Esquerdo , Inibidores da Agregação Plaquetária , Idoso , Feminino , Humanos , Masculino , Apêndice Atrial/diagnóstico por imagem , Apêndice Atrial/cirurgia , Fibrilação Atrial/tratamento farmacológico , Fibrilação Atrial/cirurgia , Hemorragia/induzido quimicamente , Hemorragia/epidemiologia , Inibidores da Agregação Plaquetária/efeitos adversos , Inibidores da Agregação Plaquetária/uso terapêutico , Estudos Prospectivos , Acidente Vascular Cerebral/epidemiologia , Trombose/epidemiologia , Resultado do Tratamento , Idoso de 80 Anos ou mais
4.
J Clin Med ; 11(24)2022 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-36556059

RESUMO

The potential benefits of Lactobacillus gasseri LA806 in IBS were previously identified in a comprehensive preclinical research program. The purpose of this multicenter study was to explore in real-life conditions changes in IBS symptoms and quality of life in patients receiving a 4-week supplementation with L. gasseri LA806. Altogether 119 patients meeting Rome IV criteria for IBS were included, of whom 118 received the supplement. The majority of patients (71.8% (95% CI 63.6−79.9%)) manifested a ≥30% decrease in abdominal pain at 4 weeks, the mean abdominal pain score diminishing by 54.2% (from 5.3 ± 2.2 to 2.2 ± 2.4, p < 0.0001). A statistically significant decrease in abdominal pain was seen as early as the first week. A decrease of ≥30% in both abdominal pain score and global IBS symptom score was attained in 61.5% of patients (95% CI 51.7−71.2%). The mean IBS-SSS score fell by 152 ± 112 points (p = 0.001), with symptoms being attenuated in 85% of patients (CGI-I). Supplementation led to a 10-fold decrease in the number of patients reporting severe IBS symptoms. The concomitant intake of antidiarrheals, antispasmodics and analgesics decreased and quality of life scores significantly improved. These preliminary results warrant confirmation by a randomized, placebo-controlled study that this study will allow a better design.

5.
J Vis Exp ; (179)2022 01 29.
Artigo em Inglês | MEDLINE | ID: mdl-35156659

RESUMO

Wood-boring invertebrates rapidly destroy marine timbers and wooden coastal infrastructure, causing billions of dollars of damage around the globe every year. As treatments of wood with broad spectrum biocides, such as creosote and chromated copper arsenate (CCA), are now restricted in marine use by legislation, naturally durable timber species and novel preservation methods of wood are required. These methods undergo testing in order to meet regulatory standards, such as the European standard for testing wood preservatives against marine borers, EN 275. Initial investigation of durable timbers species or wood preservative treatments can be achieved quickly and inexpensively through laboratory testing, which offers many advantages over marine field trials that are typically costly, long-term endeavours. Many species of Limnoria (gribble) are marine wood-boring crustaceans. Limnoria are ideal for use in laboratory testing of biodegradation of wood by marine wood-borers, due to the practicality of rearing them in aquaria and the ease of measuring their feeding rates on wood. Herein, we outline a standardizable laboratory test for assessing wood biodegradation using gribble.


Assuntos
Desinfetantes , Madeira , Animais , Cobre/análise , Desinfetantes/análise , Invertebrados , Madeira/química
6.
Clin Genitourin Cancer ; 19(6): 501-509, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34629300

RESUMO

BACKGROUND: Docetaxel (DOCE) is a standard of care in metastatic castration-resistant prostate cancer (mCRPC). Several retrospective studies suggested a decrease in Prostate Cancer incidence and mortality with metformin (MET). MET has also demonstrated anti-tumor activity in Prostate Cancer preclinical models, with increased apoptosis when added to DOCE. We aimed at exploring the role of MET in combination with DOCE in mCRPC. PATIENTS AND METHODS: Non-diabetic mCRPC patients were randomly assigned to receive DOCE 75 mg/m2 every 21 days + prednisone (5 mg. BID) with either MET 850 mg BID (D+M) or placebo (D+P) up to 10 cycles. Prostate-Specific Antigen (PSA) response ≥50% from baseline was the primary end point. Secondary end points included objective response rate (ORR), progression-free survival (PFS), overall survival (OS), toxicity and quality of life (QoL). RESULTS: Out of 99 patients were randomized (D+M = 50; D+P = 49) in 10 French centers. The median follow-up was 86 (IQR 73-88) months. The PSA-response rate reached 66% in the D+M arm, but was not different from that observed in the D+P arm (63%, P = 0,94). In the D+M and D+P arms, the ORR was 28% and 24%, the median PFS was 7.8 and 6.0 months and the median OS was 27 and 20 months (ns), respectively. Diarrhea grade I to II was more frequent in the MET arm (66% vs. 43%). No impairment of QoL was observed. CONCLUSION: MET addition failed to improve the standard DOCE regimen in mCRPC. Further research targeting tumor cell metabolism should be performed.


Assuntos
Metformina , Neoplasias de Próstata Resistentes à Castração , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Intervalo Livre de Doença , Docetaxel/uso terapêutico , Humanos , Masculino , Metformina/uso terapêutico , Prednisona/uso terapêutico , Estudos Prospectivos , Antígeno Prostático Específico , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Qualidade de Vida , Estudos Retrospectivos , Resultado do Tratamento
7.
J Clin Med ; 10(7)2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33915971

RESUMO

The LAmbreTM device is a novel system designed for left atrial appendage closure (LAAC). First registries showed a high rate of device implantation success. However, few mid-term results are available. We present our 1- and 12-month follow-up results for this device. This prospective, single-center registry included consecutive patients with nonvalvular atrial fibrillation who underwent LAAC with the LAmbreTM device. Transesophageal echocardiography (TEE) was performed at 1-month follow-up. In total, 55 patients were included. The population was elderly (75 ± 9.4 years), with a high proportion of comorbidities. The mean CHA2DS2-VASc and HAS-BLED scores were 4.6 ± 1.6 and 3.9 ± 1.0, respectively. Previous history of a major bleeding event was present in 37 patients (67.3%). Procedural success was achieved in 54 patients (98.2%). Device success was achieved in 100% of patients in whom device implantation was attempted (54 patients). Major in-hospital device-related complications included mortality of one patient (1.8%) and pericardial tamponade in two patients (3.6%); the incidence of stroke was 0%. No thrombus or significant leaks (≥5 mm) were observed on 1-month TEE. At 12 months, adverse events were overall death (1.8%), transient ischemic attack/ischemic stroke (1.8%), and major bleeding events (Bleeding Academic Research Consortium (BARC) 3a and 3c; 11%). In this high-risk population, the LAmbreTM device seems to be a safe and effective option for LAAC with a remarkable mid-term performance.

8.
J Clin Endocrinol Metab ; 106(1): e45-e60, 2021 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-33000146

RESUMO

CONTEXT: In primary aldosteronism (PA), aldosterone secretion is relatively independent of the renin-angiotensin system, but can be regulated by several other stimuli. OBJECTIVE: To evaluate aldosterone response to several stimuli in a series of patients with PA secondary either to bilateral adrenal hyperplasia (BAH) or unilateral aldosterone-producing adenoma (APA). DESIGN AND SETTING: Prospective cohort study conducted in a university teaching hospital research center. PATIENTS: Forty-three patients with confirmed PA and subtyped by adrenal vein sampling (n = 39) were studied, including 11 with BAH, 28 with APA, and 4 with undefined etiology. We also studied 4 other patients with aldosterone and cortisol cosecretion. INTERVENTIONS: We systematically explored aberrant regulation of aldosterone using an in vivo protocol that included the following stimulation tests performed over 3 days under dexamethasone suppression: upright posture, mixed meal, adrenocorticotropin (ACTH) 1-24, gonadotropin-releasing hormone (GnRH), vasopressin, and serotonin R4 agonist. MAIN OUTCOME MEASURES: Positive response was defined as >50% renin or ACTH-independent increase in plasma aldosterone/cortisol concentration following the various stimulation tests. RESULTS: Renin-independent aldosterone secretion increased in response to several aberrant stimuli (upright posture, GnRH) in up to 83% of patients with APA or BAH in whom ACTH 1-24 and HT4R agonists also produced aldosterone oversecretion in all patients. The mean significant aberrant responses per patient was similar in BAH (4.6) and in APA (4.0). CONCLUSIONS: Aldosterone secretion in PA is relatively autonomous from the renin-angiotensin system, but is highly regulated by several other stimuli, which contributes to the large variability of aldosterone levels in PA patients.


Assuntos
Aldosterona/metabolismo , Hiperaldosteronismo/epidemiologia , Hiperaldosteronismo/metabolismo , Neoplasias do Córtex Suprarrenal/epidemiologia , Neoplasias do Córtex Suprarrenal/metabolismo , Glândulas Suprarrenais/metabolismo , Glândulas Suprarrenais/patologia , Adenoma Adrenocortical/epidemiologia , Adenoma Adrenocortical/metabolismo , Adulto , Idoso , Aldosterona/sangue , Técnicas de Diagnóstico Endócrino , Feminino , Hormônio Liberador de Gonadotropina , Humanos , Hidrocortisona/sangue , Hiperaldosteronismo/sangue , Hiperaldosteronismo/diagnóstico , Hiperplasia/metabolismo , Hiperplasia/patologia , Masculino , Redes e Vias Metabólicas/fisiologia , Pessoa de Meia-Idade , Estimulação Física/métodos , Prevalência , Estudos Prospectivos , Quebeque/epidemiologia , Renina/sangue
10.
Molecules ; 24(7)2019 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-30934832

RESUMO

The use of adequate thermal energy storage (TES) systems is an opportunity to increase energy efficiency in the building sector, and so decrease both commercial and residential energy consumptions. Nano-enhanced phase change materials (NEPCM) have attracted attention to address one of the crucial barriers (i.e. low thermal conductivity) to the adoption of phase change materials (PCM) in this sector. In the present study two PCM based on fatty acids, capric and palmitic acid, were nano-enhanced with low contents (1.0 wt.%, 1.5 wt.% and 3.0 wt.%) of copper (II) oxide (CuO) nanoparticles. Copper (II) oxide (CuO) was synthesized via coprecipitation method obtaining 60⁻120 nm diameter sized nanoparticles. Thermal stability and high thermal conductivity were observed for the nano-enhanced phase change materials (NEPCM) obtained. Experimental results revealed remarkable increments in NEPCM thermal conductivity, for instance palmitic acid thermal conductivity was increased up to 60% with the addition of 3 wt.% CuO nanoparticles. Moreover, CuO nanoparticles sedimentation velocity decreases when increasing its content.


Assuntos
Materiais de Construção/análise , Nanopartículas/análise , Fenômenos Químicos , Nanopartículas/química , Nanopartículas/ultraestrutura , Análise Espectral , Condutividade Térmica , Termogravimetria
11.
Oncologist ; 22(11): 1339-1346, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28935772

RESUMO

On November 19, 2015, a marketing authorization valid through the European Union was issued for carfilzomib in combination with lenalidomide and dexamethasone for the treatment of adult patients with multiple myeloma (MM) who have received at least one prior therapy.In a phase III trial in patients with relapsed MM, median progression-free survival (PFS) for patients treated with carfilzomib in combination with lenalidomide and dexamethasone (CRd) was 26.3 months versus 17.6 months for those receiving lenalidomide and dexamethasone alone (hazard ratio = 0.69; 95% confidence interval, 0.57-0.83; one-sided log-rank p value < .0001). The most frequently observed toxicity (grade ≥3, treatment arm vs. control arm) in the phase III trial included neutropenia (29.6% vs. 26.5%), anemia (17.9% vs. 17.7%), thrombocytopenia (16.8% vs. 12.3%), pneumonia (12.5% vs. 10.5%), fatigue (7.7% vs. 6.4%), hypertension (4.6% vs. 2.1%), diarrhea (3.8% vs. 4.1%), and respiratory tract infection (4.1% vs. 2.1%).The objective of this article is to summarize the scientific review of the application leading to regulatory approval in the European Union. The scientific review concluded that the gain in PFS of 8.7 months observed with the combination of CRd was considered clinically meaningful and was supported by a clear trend in overall survival benefit, although the data were not mature. The delay in disease progression appeared superior to available alternatives in the setting of relapsed MM at the time of the marketing authorization of carfilzomib. Therefore, given the overall accepted safety profile, which was considered manageable in the current context, the benefit risk for CRd was considered positive. IMPLICATIONS FOR PRACTICE: Carfilzomib (Kyprolis) was approved in the European Union in combination with lenalidomide and dexamethasone for the treatment of adult patients with multiple myeloma who have received at least one prior therapy. The addition of carfilzomib to lenalidomide and dexamethasone resulted in a clinically meaningful and statistically significant improvement of progression-free survival compared with lenalidomide and dexamethasone, which was supported by a clear trend in overall survival benefit, although the data were not mature. At the time of the marketing authorization of carfilzomib, the delay in disease progression appeared superior to available alternatives in the setting of relapsed multiple myeloma. In terms of safety, the overall accepted safety profile was considered manageable.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Mieloma Múltiplo/tratamento farmacológico , Recidiva Local de Neoplasia/tratamento farmacológico , Oligopeptídeos/administração & dosagem , Adulto , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Dexametasona/administração & dosagem , Dexametasona/efeitos adversos , Progressão da Doença , Intervalo Livre de Doença , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/classificação , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/patologia , Europa (Continente)/epidemiologia , Feminino , Humanos , Lenalidomida , Masculino , Pessoa de Meia-Idade , Mieloma Múltiplo/epidemiologia , Mieloma Múltiplo/patologia , Recidiva Local de Neoplasia/patologia , Oligopeptídeos/efeitos adversos , Talidomida/administração & dosagem , Talidomida/efeitos adversos , Talidomida/análogos & derivados
13.
Chemistry ; 13(6): 1842-50, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17115464

RESUMO

The initial steps of an enantioselective Diels-Alder reaction catalyzed by a CuII-bissulfoximine complex were followed by EXAFS (EXAFS=extended X-ray absorption fine structure), EPR (EPR=electron paramagnetic resonance) spectroscopy (CW-EPR, FID-detected EPR, pulse ENDOR, HYSCORE; CW=continuous wave; ENDOR=electron nuclear double resonance; HYSCORE=hyperfine sublevel correlation; FID=free induction decay), and UV-visible spectroscopy. The complexes formed between the parent CuX2 (X=Cl-, Br-, TfO-, SbF6-) salts, the chiral bissulfoximine ligand (S,S)-1, and N-(1-oxoprop-2-en-1-yl)oxazolidin-2-one (2) as the substrate in CH2Cl2 were investigated in frozen and fluid solution. In all cases, penta- or hexacoordinated CuII centers were established. The complexes with counterions indicating high stereoselectivity (TfO- and SbF6-) reveal one unique species in which substrate 2 binds to pseudoequatorial positions (via O atoms), shifting the counterions to axial locations. On the other hand, those lacking stereoselectivity (X=Cl- and Br-) form two species in which the parent halogen anions remain at equatorial positions preventing the formation of geometries compatible with those found for X=TfO- and SbF6-.

14.
Bioorg Med Chem ; 14(23): 8109-25, 2006 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-16893650

RESUMO

HIV-1 infection of the brain and PAF neurotoxicity are implicated in AIDS dementia complex. We previously reported that a trisubstituted piperazine derivative is able to diminish both HIV-1 replication in monocyte-derived macrophages and PAF-induced platelet aggregation. We report in this work new compounds obtained by modifying its piperazine substituents. The structure-activity relationship study shows that a better dual activity or even pure antiretroviral compounds can be obtained in this series.


Assuntos
Síndrome da Imunodeficiência Adquirida/complicações , Fármacos Anti-HIV/síntese química , Antirretrovirais/síntese química , Demência/prevenção & controle , Piperazinas/farmacologia , Fator de Ativação de Plaquetas/antagonistas & inibidores , Fármacos Anti-HIV/farmacologia , Antirretrovirais/farmacologia , Demência/etiologia , Relação Dose-Resposta a Droga , HIV-1 , Humanos , Piperazinas/síntese química , Relação Estrutura-Atividade
15.
Eur Biophys J ; 35(6): 495-501, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16572269

RESUMO

We have performed a very extensive investigation of chromatin folding in different buffers over a wide range of ionic conditions similar to those found in eukaryotic cells. Our results show that in the presence of physiological concentrations of monovalent cations and/or low concentrations of divalent cations, small chicken erythrocyte chromatin fragments and chromatin from HeLa cells observed by transmission electron microscopy (TEM) show a compact folding, forming circular bodies of approximately 35 nm in diameter that were found previously in our laboratory in studies performed under very limited conditions. Since TEM images are obtained with dehydrated samples, we have performed atomic force microscopy (AFM) experiments to analyze chromatin structure in the presence of solutions containing different cation concentrations. The highly compact circular structures (in which individual nucleosomes are not visible as separated units) produced by small chromatin fragments in interphase ionic conditions observed by AFM are equivalent to the structures observed by TEM with chromatin samples prepared under the same ionic conditions. We have also carried out experiments of sedimentation and trypsin digestion of chromatin fragments; the results obtained confirm our AFM observations. Our results suggest that the compaction of bulk interphase chromatin in solution at room temperature is considerably higher than that generally considered in current literature. The dense chromatin folding observed in this study is consistent with the requirement of compact chromatin structures as starting elements for the building of metaphase chromosomes, but poses a difficult physical problem for gene expression during interphase.


Assuntos
Cátions/química , Montagem e Desmontagem da Cromatina/fisiologia , Cromatina/química , Animais , Fenômenos Biofísicos , Biofísica , Galinhas , Cromatina/ultraestrutura , Eritrócitos , Células HeLa , Humanos , Microscopia de Força Atômica , Microscopia Eletrônica de Transmissão , Tripsina , Água
16.
J Clin Endocrinol Metab ; 91(2): 361-4, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16278263

RESUMO

CONTEXT: Calcitonin is a well-established tumor marker for medullary thyroid carcinoma (MTC). Because surgery is the only effective treatment for patients with MTC, the postoperative level of serum calcitonin will dictate whether residual disease was left behind and whether reintervention is necessary. RESULTS: We describe here the case of a 41-yr-old man with metastatic MTC. Despite extensive disease in the neck as well as metastatic lesions in the liver, his serum calcitonin, measured with a commercial one-step immunoradiometric assay, was only minimally elevated (244 ng/liter). After serial dilutions, a nonlinear relationship became evident, suggesting the presence of a "hook effect." Treatment of the serum with heterophilic blocking reagent revealed no change. Calcitonin was then measured with a different immunoradiometric assay and revealed a much higher level. Similar discrepancies were found in different samples from various patients when analyzed with different calcitonin immunoassays. CONCLUSION: To our knowledge, this is the first reported case of a phenomenon such as the hook effect in a calcitonin immunoradiometric assay in patients with MTC. Being aware of this phenomenon is important, because a low calcitonin result could give false reassurance to both the patient and the clinician and could dramatically change the prognosis of the patient.


Assuntos
Biomarcadores Tumorais/sangue , Calcitonina/sangue , Carcinoma Medular/sangue , Neoplasias da Glândula Tireoide/sangue , Adulto , Carcinoma Medular/patologia , Carcinoma Medular/secundário , Humanos , Ensaio Imunorradiométrico/métodos , Neoplasias Hepáticas/sangue , Neoplasias Hepáticas/secundário , Neoplasias da Glândula Tireoide/patologia
17.
Int Immunol ; 17(8): 1047-57, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15976033

RESUMO

IFN-tau is a non-cytotoxic type I IFN responsible for maternal recognition of the foetus in ruminants. IFN-tau has been found to inhibit HIV replication more strongly than human IFN-alpha, particularly in human monocyte-derived macrophages, without associated toxicity. Ovine IFN-tau uses the same anti-viral cellular pathways as human IFN-alpha in human macrophages, principally inhibiting the early steps of the biological cycle of HIV, preventing the integration of HIV DNA into the host-cell genome. In this study, we investigated the immunomodulatory properties of IFN-tau in human macrophages. We found that IFN-tau increased the production of IL-10 and IL-6, but not of IL-1beta or tumour necrosis factor alpha, in unstimulated, LPS-stimulated and HIV-1/Ba-L-infected macrophages. We also found that treatment with IL-6 inhibited HIV replication. Moreover, the neutralization of IL-6 activity in the cell culture supernatants of IFN-tau-treated macrophages led to a decrease in the anti-retroviral effects of IFN-tau, suggesting that IL-6 was involved in the anti-viral activity induced by IFN-tau. By focusing on the very early steps of the biological cycle of HIV, we showed that IL-6 co-operated with IFN-tau to decrease intracellular HIV RNA levels 2 h after infection.


Assuntos
HIV-1/efeitos dos fármacos , HIV-1/imunologia , Interferon Tipo I/farmacologia , Interleucina-6/biossíntese , Proteínas da Gravidez/farmacologia , Animais , HIV-1/fisiologia , Humanos , Fatores Imunológicos/farmacologia , Técnicas In Vitro , Interleucina-1/biossíntese , Interleucina-10/biossíntese , Interleucina-10/farmacologia , Interleucina-6/farmacologia , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Macrófagos/virologia , Proteínas Recombinantes/farmacologia , Ovinos , Fator de Necrose Tumoral alfa/biossíntese , Replicação Viral/efeitos dos fármacos
18.
J Med Chem ; 47(25): 6410-9, 2004 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-15566310

RESUMO

The HIV-1 central nervous system infection leads to the onset of neurological impairments called AIDS dementia complex (ADC). PAF plays an important role in this pathology, as it is an HIV-1-induced neurotoxin produced by infected or activated macrophages and microglia, in the brain. We previously reported that PAF-antagonists bearing a trisubstituted piperazine presented in vitro anti-HIV-1 activity in human macrophages. To improve the pharmacological activities of our lead compound, 1a, we modified its carbamate function and evaluated both its antiretroviral and anti-PAF activities. One carbamate derivative (10c) demonstrated a similar antiviral activity but a higher anti-PAF potency, whereas 4a, with an ureide function, presents an increased antiviral activity and can be considered as a pure antiretroviral drug, as it does not present PAF-antagonism. Moreover, we measured the ability of 1a to cross the blood-brain barrier, using the in situ mouse brain perfusion method and its plasmatic concentrations after iv and po administration. The transport parameter measured (K(in)) proves that 1a is able to cross this biological barrier, but a pharmacokinetic study reveals its weak bioavailability in rats.


Assuntos
Fármacos Anti-HIV/síntese química , HIV-1/efeitos dos fármacos , Piperazinas/síntese química , Fator de Ativação de Plaquetas/antagonistas & inibidores , Animais , Fármacos Anti-HIV/química , Fármacos Anti-HIV/farmacologia , Disponibilidade Biológica , Barreira Hematoencefálica/metabolismo , Carbamatos/síntese química , Carbamatos/química , Carbamatos/farmacologia , Células Cultivadas , Humanos , Técnicas In Vitro , Macrófagos/efeitos dos fármacos , Macrófagos/virologia , Masculino , Camundongos , Permeabilidade , Piperazinas/química , Piperazinas/farmacologia , Agregação Plaquetária/efeitos dos fármacos , Coelhos , Ratos , Ratos Sprague-Dawley , Relação Estrutura-Atividade , Replicação Viral/efeitos dos fármacos
19.
J Virol ; 77(23): 12914-20, 2003 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-14610214

RESUMO

Tau interferon (IFN-tau) is a noncytotoxic type I IFN responsible for maternal recognition of the fetus in ruminants. IFN-tau inhibits human immunodeficiency virus (HIV) replication more strongly than human IFN-alpha, particularly in human monocyte-derived macrophages. In this study performed in human macrophages, IFN-tau efficiently inhibited the early steps of the biological cycle of HIV, decreasing intracellular HIV RNA and inhibiting the initiation of the reverse transcription of viral RNA into proviral DNA. Two mechanisms induced by IFN-tau treatment in macrophages may account for this inhibition: (i) the synthesis of the cellular antiviral factors such as 2',5'-oligoadenylate synthetase/RNase L and MxA protein and (ii) an increased production of MIP-1alpha, MIP-1beta, and RANTES, which are natural ligands of CCR5, the principal coreceptor of HIV on macrophages. Our results suggest that IFN-tau induces the same antiviral pathways in macrophages as other type I IFNs but without associated toxicity.


Assuntos
Quimiocinas CC/fisiologia , HIV/efeitos dos fármacos , Interferon Tipo I/farmacologia , Proteínas da Gravidez/farmacologia , Replicação Viral/efeitos dos fármacos , HIV/genética , HIV/fisiologia , Humanos , Macrófagos/metabolismo , Macrófagos/virologia , RNA Viral/sangue , Transcrição Gênica
20.
J Am Chem Soc ; 125(20): 6222-7, 2003 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-12785854

RESUMO

The structure of Cu(II) complex 3 formed within the course of a stereoselective Diels-Alder reaction was investigated by EXAFS, CW-EPR at X- and W-band, HYSCORE, pulsed ENDOR, and UV-vis spectroscopy. The experimental techniques indicate that the chiral bis(sulfoximine) ligand (S,S)-1 and the dienophile form a tetragonally distorted complex in CH(2)Cl(2). The ligand binds to the Cu(II) center via the imine nitrogens, whereas the dienophile interacts via the carbonyl oxygen atoms. The additional sites of the first coordination sphere are occupied by counterions and, presumably, solvent molecules. At the axial position, a triflate anion binds via an oxygen atom.

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