Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 131
Filtrar
Mais filtros

Tipo de documento
Intervalo de ano de publicação
1.
Nature ; 555(7695): 220-222, 2018 03 07.
Artigo em Inglês | MEDLINE | ID: mdl-29517001

RESUMO

The gravity harmonics of a fluid, rotating planet can be decomposed into static components arising from solid-body rotation and dynamic components arising from flows. In the absence of internal dynamics, the gravity field is axially and hemispherically symmetric and is dominated by even zonal gravity harmonics J2n that are approximately proportional to qn, where q is the ratio between centrifugal acceleration and gravity at the planet's equator. Any asymmetry in the gravity field is attributed to differential rotation and deep atmospheric flows. The odd harmonics, J3, J5, J7, J9 and higher, are a measure of the depth of the winds in the different zones of the atmosphere. Here we report measurements of Jupiter's gravity harmonics (both even and odd) through precise Doppler tracking of the Juno spacecraft in its polar orbit around Jupiter. We find a north-south asymmetry, which is a signature of atmospheric and interior flows. Analysis of the harmonics, described in two accompanying papers, provides the vertical profile of the winds and precise constraints for the depth of Jupiter's dynamical atmosphere.

2.
Lett Appl Microbiol ; 73(2): 247-256, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34008189

RESUMO

Lactic acid bacteria (LAB) exert antagonistic activities against diverse microorganisms, including pathogens. In this work, we aimed to investigate the ability of LAB strains isolated from food to produce biofilms and to inhibit growth and surface colonization of Enterohaemorrhagic Escherichia coli (EHEC) O157:H7 at 10°C. The ability of 100 isolated LAB to inhibit EHEC O157:H7 NCTC12900 growth was evaluated in agar diffusion assays. Thirty-seven LAB strains showed strong growth inhibitory effect on EHEC. The highest inhibitory activities corresponded to LAB strains belonging to Lactiplantibacillus plantarum, Pediococcus acidilactici and Pediococcus pentosaceus species. Eighteen out of the 37 strains that showed growth inhibitory effects on EHEC also had the ability to form biofilms on polystyrene surfaces at 10°C and 30°C. Pre-established biofilms on polystyrene of four of these LAB strains were able to reduce significantly surface colonization by EHEC at low temperature (10°C). Among these four strains, Lact. plantarum CRL 1075 not only inhibited EHEC but also was able to grow in the presence of the enteric pathogen. Therefore, this strain proved to be a good candidate for further technological studies oriented to its application in food-processing environments to mitigate undesirable surface contaminations of E. coli.


Assuntos
Antibiose , Biofilmes/crescimento & desenvolvimento , Escherichia coli O157/crescimento & desenvolvimento , Lactobacillales/fisiologia , Manipulação de Alimentos , Microbiologia de Alimentos , Interações Microbianas , Probióticos
3.
BMC Cancer ; 20(1): 1079, 2020 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-33167914

RESUMO

BACKGROUND: In recent years, the identification of genetic and phenotypic biomarkers of cancer for prevention, early diagnosis and patient stratification has been a main objective of research in the field. Different multivariable models that use biomarkers have been proposed for the evaluation of individual risk of developing breast cancer. METHODS: This is a case control study based on a population-based cohort. We describe and evaluate a multivariable model that incorporates 92 Single-nucleotide polymorphisms (SNPs) (Supplementary Table S1) and five different phenotypic variables and which was employed in a Spanish population of 642 healthy women and 455 breast cancer patients. RESULTS: Our model allowed us to stratify two groups: high and low risk of developing breast cancer. The 9th decile included 1% of controls vs 9% of cases, with an odds ratio (OR) of 12.9 and a p-value of 3.43E-07. The first decile presented an inverse proportion: 1% of cases and 9% of controls, with an OR of 0.097 and a p-value of 1.86E-08. CONCLUSIONS: These results indicate the capacity of our multivariable model to stratify women according to their risk of developing breast cancer. The major limitation of our analysis is the small cohort size. However, despite the limitations, the results of our analysis provide proof of concept in a poorly studied population, and opens up the possibility of using this method in the routine screening of the Spanish population.


Assuntos
Biomarcadores Tumorais/genética , Neoplasias da Mama/epidemiologia , Predisposição Genética para Doença , Fenótipo , Polimorfismo de Nucleotídeo Único , Medição de Risco/métodos , Adulto , Idoso , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/genética , Estudos de Casos e Controles , Feminino , Seguimentos , Estudo de Associação Genômica Ampla , Genótipo , Humanos , Pessoa de Meia-Idade , Prognóstico , Espanha/epidemiologia , Adulto Jovem
4.
Clin Genet ; 85(2): 184-8, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23509885

RESUMO

In the last decades, nine inherited errors of the distal part of cholesterol biosynthesis have been recognized. Affected patients present complex malformation syndromes involving different organs and systems with variable degrees of severity. We report on the phenotype evolution of three patients with enzymatic defects at three distinct steps of such pathway: Smith-Lemli-Opitz syndrome, X-linked dominant chondrodysplasia punctata type 2 and congenital hemidysplasia with ichthyosiform erythroderma and limb defects syndrome. The patients' natural history, from childhood to adulthood, is thoroughly described in order to contribute for a better knowledge of these diseases. Our ultimate goals are to contribute for a better characterization of the long-term course of these metabolic disorders and for the recognition of such diseases in older patients.


Assuntos
Anormalidades Múltiplas/fisiopatologia , Condrodisplasia Punctata/fisiopatologia , Doenças Genéticas Ligadas ao Cromossomo X/fisiopatologia , Eritrodermia Ictiosiforme Congênita/fisiopatologia , Deformidades Congênitas dos Membros/fisiopatologia , Fenótipo , Síndrome de Smith-Lemli-Opitz/fisiopatologia , Adolescente , Adulto , Criança , Pré-Escolar , Colesterol/biossíntese , Progressão da Doença , Feminino , Humanos , Recém-Nascido , Masculino
5.
Artigo em Inglês | MEDLINE | ID: mdl-38082841

RESUMO

Atrial biophysical simulations have the potential to enhance outcomes by enabling the simulation of pharmacological and ablative strategies. However, the high computational times associated with such simulations render them unsuitable for diagnostic purposes. To address this challenge, discrete models such as cellular automata (CA) have been developed, which consider a finite number of states, thus significantly reducing computational times. Yet, there is a pressing need to determine whether CA can replicate pathological simulations with accuracy. The analysis of simulations under different degrees of electrical remodeling shows an expected increase of Action Potential Duration (APD) with the previous Diastolic Interval (DI) interval, indicating short-term memory of atrial cardiomyocytes: shorter APD0 provoked shorter APD+1, and previous DI has a similar effect on APD+1. Independent prediction using both APD0 and DI was found to provide a far better estimation of APD+1 values, compared to relying on DI alone (p<<0.01). Finally, the CA models were able to replicate reentrant patterns and cycle lengths of different states of atrial remodeling with a high degree of accuracy when compared to biophysical simulations. Overall, the use of atrial CA with short-term memory allows accurate reproduction of arrhythmic behavior in pathological tissue within a clinically relevant timeframe.Clinical Relevance- Discrete electrophysiological models simulate pathological self-sustained arrhythmias in diagnostic times.


Assuntos
Fibrilação Atrial , Humanos , Fibrilação Atrial/diagnóstico , Átrios do Coração , Miócitos Cardíacos , Potenciais de Ação
6.
Artigo em Inglês | MEDLINE | ID: mdl-38083190

RESUMO

Patients that have suffered a myocardial infarction are at high risk of developing ventricular tachycardia. Patient stratification is often determined by characterization of the underlying myocardial substrate by cardiac imaging methods. In this study, we show that computer modeling of cardiac electrophysiology based on personalized fast 3D simulations can help to assess patient risk to arrhythmia. We perform a large simulation study on 21 patient digital twins and reproduce successfully the clinical outcomes. In addition, we provide the sites which are prone to sustain ventricular tachycardias, i.e, onset sites around the scar region, and validate if they colocalize with exit sites from slow conduction channels.Clinical relevance- Fast electrophysiological simulations can provide advanced patient stratification indices and predict arrhythmic susceptibility to suffer from ventricular tachycardia in patients that have suffered a myocardial infarction.


Assuntos
Infarto do Miocárdio , Taquicardia Ventricular , Humanos , Taquicardia Ventricular/diagnóstico , Arritmias Cardíacas , Miocárdio , Infarto do Miocárdio/complicações , Infarto do Miocárdio/diagnóstico , Eletrofisiologia Cardíaca
7.
Physiol Res ; 72(6): 809-818, 2023 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-38215066

RESUMO

Wound healing is a dynamic process involving different cell types with distinct roles according to the stages of healing. Fibroblasts and stem cells actively participate in tissue regeneration. A proper stimulation could contribute to enhance wound healing process-es. Helichrysum italicum (H. italicum) is a medical plant well described for its pharmacological, antimicrobial, and anti-inflammatory activities. Aim of the present work was to examine the effect of the hydrolat derivate from H. italicum on stem cells isolated from skin and fibroblasts in vitro in presence or absence of tissue damage. The viability and proliferation of all cell types cultured in dif-ferent conditions were analyzed by MTT and BrdU assays. Cell proliferation after wound was analyzed with scratch test. Also, the expression of the main genes involved in tissue repair was evaluated by RT-qPCR analysis. Here we describe the capability of hy-drolat of H. italicum to promote tissue regeneration after scratch test both in stem cells and in fibroblasts. Moreover, the gene ex-pression analysis revealed that, hydrolat of H. italicum is also able to enhance stemness related. In conclusion our results are en-couraging, highlighting novel regenerative properties of hydrolat of H. italicum and paving the way for future application of this wasting product in accelerating wound healing.


Assuntos
Helichrysum , Cicatrização , Pele , Anti-Inflamatórios/farmacologia , Células-Tronco , Fibroblastos/metabolismo
8.
Langmuir ; 28(19): 7461-9, 2012 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-22515332

RESUMO

Adherence to a biological surface allows bacteria to colonize and persist within the host and represents an essential first step in the pathogenesis of most bacterial diseases. Consequently, the physicochemical properties of the outer membrane in bacteria play a key role for attachment to surfaces and therefore for biofilm formation. Bordetella pertussis is a Gram-negative bacterium that colonizes the respiratory tract of humans, producing whooping cough or pertussis, a highly infectious disease. B. pertussis uses various adhesins exposed on its surface to promote cell-surface and cell-cell interactions. The most dominant adhesin function is displayed by filamentous hemagglutinin (FHA). B. pertussis Tohama I wild-type (Vir+) strain and two defective mutants, an avirulent (Vir-) and a FHA-deficient (FHA-) B. pertussis strains were studied by AFM under physiological conditions to evaluate how the presence or absence of adhesins affects the mechanical properties of the B. pertussis cell surface. Quantitative information on the nanomechanical properties of the bacterial envelope was obtained by AFM force-volume analysis. These studies suggested that the presence of virulence factors is correlated with an increase in the average membrane rigidity, which is largely influenced by the presence of FHA. Moreover, for this system we built a nanoscale stiffness map that reveals an inhomogeneous spatial distribution of Young modulus as well as the presence of rigid nanodomains on the cell surface.


Assuntos
Adesinas Bacterianas/metabolismo , Fenômenos Biomecânicos/fisiologia , Bordetella pertussis/metabolismo , Virulência/fisiologia
9.
G Ital Dermatol Venereol ; 146(2): 155-8, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21505400

RESUMO

We report the case of a 65-year-old female patient that has suffered several flares of exanthematous pustulosis, some of them attributable to pustular psoriasis and others that were drug-induced, resembling acute generalized exanthematous pustulosis. In particular, we describe two severe flares that were induced by ciprofloxacin. Patch tests yielded positive results to ciprofloxacin and to other quinolones and reproduced the original lesional pattern both clinically and histologically. We discuss the diagnostic challenge that exanthematous pustulosis represents and the value of patch testing in this setting, as a helpful tool to assess drug participation in these eruptions.


Assuntos
Anti-Infecciosos/efeitos adversos , Ciprofloxacina/efeitos adversos , Exantema/induzido quimicamente , Psoríase/complicações , Dermatopatias Vesiculobolhosas/induzido quimicamente , Idoso , Diagnóstico Diferencial , Exantema/diagnóstico , Feminino , Humanos , Testes do Emplastro , Dermatopatias Vesiculobolhosas/diagnóstico
10.
Arch Environ Occup Health ; 76(1): 1-11, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32048551

RESUMO

Cashew nut shells (CNS) is already used in the energy matrix of some industries. However, it is necessary to know the harmful health effects generated by exposure to pollutants of its combustion, especially in the workers exposed to industrial pollutants. In addition, it is known that the incidence of asthma grows among workers in industries, and due to its previously reported biological effects of anethole, these will also be objects of the present study. We used 64 Balb/C mice, randomly divided into eight groups. Groups were sensitized and challenged with saline or ovalbumin, then subjected to intranasal instillation of 30 µg PM4.0 (occupational exposure) from the combustion of CNS or saline, and then were subsequently treated with oral anethole 300 mg/kg or 0.1% Tween 80. Our results serve as a starting point for the development of public policies for the prevention of diseases in workers that are exposed to the pollutants coming from industries.


Assuntos
Poluentes Ocupacionais do Ar/efeitos adversos , Anacardium , Indústria de Processamento de Alimentos , Exposição Ocupacional/efeitos adversos , Material Particulado/efeitos adversos , Derivados de Alilbenzenos , Animais , Anisóis , Modelos Animais de Doenças , Pulmão/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos BALB C , Polissorbatos , Distribuição Aleatória
11.
J Eur Acad Dermatol Venereol ; 24(12): 1421-4, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20384689

RESUMO

BACKGROUND: Management of incompletely excised basal cell carcinomas (BCC) remains controversial. OBJECTIVE: The aim of this study was to assess the rate and the factors associated with the recurrence of incompletely excised BCC. METHODS: In this retrospective monocentric study, data from all surgically excised BCC during 4 years (2000 to 2003) were analysed. RESULTS: A total of 947 BCC were excised. Of these, 90 were incompletely excised (9.5%). This group was kept under clinical follow-up for a median period of 62.5 months (range 12-84). Recurrence was confirmed in 29 patients (32.2%). The median interval to recurrence was 12 months (range 1-57). Recurrence of incompletely excised BCC was significantly higher (P < 0.05) in younger patients, in aggressive histological types and in localizations like postauricular and nasogenian folds. CONCLUSION: Observation might be an acceptable option in many situations, but for patients with aggressive types of BCC, or with tumours localized in risk areas of the face, immediate re-excision appears to be the treatment of choice. A careful follow-up is indicated for at least 3 years; however, long lasted recurrence should not be underestimated.


Assuntos
Carcinoma Basocelular/patologia , Neoplasias Cutâneas/patologia , Idoso , Carcinoma Basocelular/cirurgia , Feminino , Humanos , Incidência , Masculino , Recidiva , Neoplasias Cutâneas/cirurgia
12.
J Neuroradiol ; 36(4): 237-9, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19682745

RESUMO

The epidermal nevus syndrome is characterized by several developmental anomalies associated with an epidermal nevus. In addition to the skin, other organs commonly affected include the brain, eyes and musculoskeletal system. We report here on a 24-year-old woman with this syndrome who presented with hemifacial hypertrophy, hearing abnormalities, arrhythmia and an unusual infratentorial brain involvement.


Assuntos
Doenças Cerebelares/complicações , Nevo Pigmentado/complicações , Neoplasias Cutâneas/complicações , Arritmias Cardíacas/complicações , Assimetria Facial/complicações , Feminino , Perda Auditiva/complicações , Humanos , Imageamento por Ressonância Magnética , Síndrome , Adulto Jovem
13.
Cytotherapy ; 10(3): 289-302, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18418774

RESUMO

BACKGROUND: Cytomegalovirus (CMV) infection and its treatment causes significant morbidity following allogeneic stem cell transplantation (SCT) for malignancies. We studied the phenotype, function and growth kinetics of CMV pp65 antigen (Ag)-specific T cells expanded in a short-term culture for adoptive therapy. METHODS: Peripheral blood mononuclear cells (PBMC) from CMV-seropositive donors were cultured in various conditions with CMV pp65((495-503)) peptide to determine the most effective method for generating CMV-specific T cells. CMV-expanded cultures were tested for frequency, phenotype and functionality using peptide-MHC tetramer analysis, cytokine flow cytometry and cytolytic assays. A patient undergoing allogeneic SCT was administered CMV pp65-specific T cells generated from the donor based on these data, and recipient PBMC were analyzed following T-cell infusion. RESULTS: CMV pp65-specific T cells were consistently generated from CMV-seropositive donors at high frequencies (20-40% of CD8+ T cells), secreted interferon-gamma (IFN-gamma) in response to CMV peptide and had lytic activity against CMV peptide-expressing targets. Cultured CMV-specific T cells were infused into a SCT recipient without toxicity. DISCUSSION: Stimulating donor PBMC to generate functional, Ag-specific T cells for infusion into SCT recipients was accomplished consistently using readily available technology. We observed no toxicity in one patient receiving T cells and were able to monitor infused cells. These findings support further study of this approach as a prophylaxis against the risk of infection in patients receiving allogeneic transplantation from CMV-seropositive donors.


Assuntos
Infecções por Citomegalovirus/imunologia , Citomegalovirus/imunologia , Imunoterapia Adotiva , Neoplasias/terapia , Transplante de Células-Tronco , Linfócitos T/imunologia , Linfócitos T CD8-Positivos/imunologia , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Células Clonais , Citocinas/metabolismo , Citomegalovirus/efeitos dos fármacos , Epitopos , Transplante de Células-Tronco Hematopoéticas , Humanos , Cinética , Ativação Linfocitária/efeitos dos fármacos , Neoplasias/imunologia , Neoplasias/patologia , Peptídeos/farmacologia , Fenótipo , Receptores de Antígenos de Linfócitos T alfa-beta/imunologia , Linfócitos T/efeitos dos fármacos , Linfócitos T/metabolismo , Transplante Homólogo
14.
Int J Clin Pharmacol Ther ; 46(7): 349-64, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18793589

RESUMO

BACKGROUND: Vildagliptin is a selective inhibitor of dipeptidyl peptidase IV (DPP-4) that improves glycemic control and pancreatic b-cell function in patients with Type 2 diabetes. Vildagliptin may be an appropriate agent to combine with other antihyperglycemic agents in patients requiring combination therapy to achieve optimal glycemic control. Two studies were performed to determine the potential for pharmacokinetic and pharmacodynamic interactions between vildagliptin and the sulfonylurea, glyburide, or pioglitazone in patients with Type 2 diabetes. METHODS: Two open-label, multiple-dose, 3-period, randomized, crossover studies in patients with Type 2 diabetes were carried out. Steady state drug pharmacokinetics and postprandial plasma glucose and insulin responses were assessed during treatment with vildagliptin 100 mg b.i.d. alone and in combination with glyburide 10 mg q.d. (n = 17) or with vildagliptin 100 mg q.d. alone or in combination with pioglitazone 45 mg q.d. (n = 15). RESULTS: Coadministration of vildagliptin with either glyburide or pioglitazone had no clinically significant effect on the pharmacokinetics of any of the 3 drugs. Changes in AUC and Cmax during combination treatment were small ( pound 15%), and 90% confidence intervals for the geometric mean ratios (drug coadministration/monotherapy) were generally contained within the acceptance range for bioequivalence (0.80 - 1.25). Vildagliptin/glyburide coadministration significantly reduced the area under the plasma glucose-time curve compared with glyburide alone (AUE0-5h reduced by 12% (p = 0.005) and AUE0-15h by 13% (p = 0.003)), and increased the area under the plasma insulin-time curve (AUE0-15h increased by 12% (p = 0.041)). Vildagliptin/pioglitazone coadministration also significantly reduced postprandial glucose exposure compared with pioglitazone alone (AUE0.5-5.5h reduced by 11% (p = 0.029) and AUE0-15.5h by 10% (p = 0.019)). Vildagliptin was generally well tolerated whether administered alone or in combination with glyburide or pioglitazone, and was not associated with hypoglycemia. CONCLUSIONS: Coadministration of vildagliptin with either glyburide or pioglitazone in patients with Type 2 diabetes improves postprandial glycemic control without notable effects on drug pharmacokinetics.


Assuntos
Adamantano/análogos & derivados , Diabetes Mellitus Tipo 2/tratamento farmacológico , Inibidores da Dipeptidil Peptidase IV/administração & dosagem , Hipoglicemiantes/administração & dosagem , Nitrilas/administração & dosagem , Pirrolidinas/administração & dosagem , Adamantano/administração & dosagem , Adamantano/efeitos adversos , Adamantano/farmacocinética , Adulto , Idoso , Área Sob a Curva , Glicemia/efeitos dos fármacos , Estudos Cross-Over , Inibidores da Dipeptidil Peptidase IV/efeitos adversos , Inibidores da Dipeptidil Peptidase IV/farmacocinética , Interações Medicamentosas , Feminino , Glibureto/administração & dosagem , Glibureto/efeitos adversos , Glibureto/farmacocinética , Humanos , Hipoglicemiantes/efeitos adversos , Hipoglicemiantes/farmacocinética , Insulina/metabolismo , Masculino , Pessoa de Meia-Idade , Nitrilas/efeitos adversos , Nitrilas/farmacocinética , Pioglitazona , Pirrolidinas/efeitos adversos , Pirrolidinas/farmacocinética , Tiazolidinedionas/administração & dosagem , Tiazolidinedionas/efeitos adversos , Tiazolidinedionas/farmacocinética , Vildagliptina
15.
Rev Epidemiol Sante Publique ; 56(5): 303-13, 2008 Oct.
Artigo em Francês | MEDLINE | ID: mdl-18951740

RESUMO

BACKGROUND: The two aims of the study were, first to estimate the declared two-year coverage of breast cancer and cervical cancer screenings, and second to determine the main factors influencing female cancer screening behaviors. METHODS: Three groups of women from the 2003 French decennial health interview survey were analyzed: 3378 women aged 50-74 years who answered the question on mammography use, 7912 women aged 25-65 years who answered the question on Pap-smear use, and 2528 women aged 50-65 years who answered both questions. RESULTS: The declared coverage of breast cancer screening was 71.2%, the declared coverage of cervical cancer screening was 76.3%. Almost 18% of women declared having undergone neither a mammography nor a Pap-smear in the last two years. The main factor linked to a more frequent practice of one or both cancer screenings (breast or cervix) was to have undergone recently the other screening. The other factors linked to mammography use were mainly healthcare and practitioner access variables. Those linked to Pap-smear use were mainly socioeconomic and socio-demographic variables, healthcare and practitioner access variables being also linked. The main factors linked to having undergone none of these two screenings were of financial nature, particularly household income and home ownership. CONCLUSION: The study showed that it is appropriate to communicate on both screenings at the same time since they have a positive effect each other. Finally, practitioners continue to play a central role in collecting information on cancer screenings and encouraging screening in women not regularly screened.


Assuntos
Neoplasias da Mama/prevenção & controle , Mamografia/estatística & dados numéricos , Programas de Rastreamento/estatística & dados numéricos , Teste de Papanicolaou , Neoplasias do Colo do Útero/prevenção & controle , Esfregaço Vaginal/estatística & dados numéricos , Idoso , Índice de Massa Corporal , Interpretação Estatística de Dados , Exercício Físico , Feminino , França , Acessibilidade aos Serviços de Saúde , Humanos , Pessoa de Meia-Idade , Fatores Socioeconômicos , Inquéritos e Questionários , Fatores de Tempo
16.
J Clin Invest ; 77(6): 1917-24, 1986 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-2423559

RESUMO

Pulmonary alveolar macrophages (PAM), obtained by bronchoalveolar lavage from 47 individuals, reduced hexavalent chromium [Cr(VI)] and decreased its mutagenicity. Their specific activity--mostly mediated by cytosolic, enzyme-catalyzed mechanisms--was significantly higher than in corresponding preparations of mixed-cell populations from human peripheral lung parenchyma or bronchial tree, or from rat lung or liver. At equivalent number of PAM, Cr(VI) reduction, total protein, and some oxidoreductase activities were significantly increased in smokers. No appreciable variation could be detected between lung cancer and noncancer patients. In rats, the Cr(VI)-reducing activity of PAM preparations was induced by Aroclor 1254. Thus, alveolar macrophages provide crucial defense mechanisms not only by phagocytizing metals, but also by metabolically reducing Cr(VI). The epithelial-lining fluid (ELF) also displayed some Cr(VI) reduction. Together with already investigated metabolic processes occurring inside lung cells, these mechanisms are expected to determine thresholds in the pulmonary carcinogenicity of chromium.


Assuntos
Cromo/metabolismo , Alvéolos Pulmonares/metabolismo , Fumar , Animais , Arocloros/farmacologia , Dicumarol/farmacologia , Di-Hidrolipoamida Desidrogenase/análise , Glucosefosfato Desidrogenase/análise , Humanos , Concentração de Íons de Hidrogênio , Masculino , Testes de Mutagenicidade , NADPH Desidrogenase/análise , Fosfogluconato Desidrogenase/análise , Ratos , Ratos Endogâmicos , Fatores de Tempo
17.
Nucleic Acids Res ; 29(14): 3108-15, 2001 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-11452036

RESUMO

Carnitine octanoyltransferase (COT) produces three different transcripts in rat through cis- and trans-splicing reactions, which may lead to the synthesis of two proteins. Generation of the three COT transcripts in rat does not depend on sex, development, fat feeding, the inclusion of the peroxisome proliferator diethylhexyl phthalate in the diet or hyperinsulinemia. In addition, trans-splicing was not detected in COT of other mammals, such as human, pig, cow and mouse, or in Cos7 cells from monkey. Rat COT exon 2 contains two purine-rich sequences. Mutation of the rat COT exon 2 upstream box does not affect the trans-splicing in vitro between two truncated constructs containing exon 2 and its adjacent intron boundaries. In contrast, mutation of the downstream box from the rat sequence (GAAGAAG) to a random sequence or the sequence observed in the other mammals (AAAAAAA) decreased trans-splicing in vitro. In contrast, mutation of the AAAAAAA box of human COT exon 2 to GAAGAAG increases trans-splicing. Heterologous reactions between COT exon 2 from rat and human do not produce trans-splicing. HeLa cells transfected with minigenes of rat COT sequences produced cis- and trans-spliced bands. Mutation of the GAAGAAG box to AAAAAAA abolished trans-splicing and decreased cis-splicing in vivo. We conclude that GAAGAAG is an exonic splicing enhancer that could induce natural trans-splicing in rat COT.


Assuntos
Processamento Alternativo , Carnitina Aciltransferases/genética , Elementos Facilitadores Genéticos/genética , Éxons/genética , Animais , Sequência de Bases , Northern Blotting , Células COS , Bovinos , DNA Complementar/química , DNA Complementar/genética , Feminino , Regulação Enzimológica da Expressão Gênica , Células HeLa , Humanos , Intestinos/enzimologia , Fígado/enzimologia , Masculino , Camundongos , Dados de Sequência Molecular , Mutação , Precursores de RNA/genética , Precursores de RNA/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Alinhamento de Sequência , Análise de Sequência de DNA , Homologia de Sequência do Ácido Nucleico , Suínos
18.
Cancer Res ; 45(7): 3188-96, 1985 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-4005852

RESUMO

Rat liver postmitochondrial (S-12) fractions accounted for the bulk of the activity of whole cell homogenates in reducing chromium(VI) and accordingly in decreasing its mutagenicity. Both cytosolic (S-105) and microsomal fractions concurred to this process, which in all subcellular preparations tested was selectively induced by phenobarbital and especially by Aroclor 1254, but not by 3-methylcholanthrene. Cytosolic fractions were markedly more efficient in reducing chromium(VI) than microsomal fractions recovered from the same amount of tissue (liver or lung), although the latter preparations had a higher specific activity. The microsomal activity was exclusively NADPH dependent. A minor part of the cytosolic reduction was determined by nonenzymatic components, notably by some electron donors and chiefly by reduced glutathione, which proved to reduce chromium(VI) at physiological concentrations. However, also in cytosolic fractions, the most important contribution to chromium reduction was enzyme catalyzed, as shown by the following properties: thermolability; requirement for exogenous NADH or NADPH [supplied as such or in the form of a NADPH-generating system (S-9 mix)]; and saturation by chromium(VI). The likely involvement of DT-diaphorase in this metabolic process is supported by several findings, including its sharp pH dependence and its partial suppression by known inhibitors of this enzyme protein, such as p-chloromercuribenzoate, L-thyroxine, and dicumarol (which conversely did not counteract the metabolic deactivation of the other direct-acting mutagens 2-methoxy-6-chloro-9-[3-(2-chloroethyl)aminopropylamino]acridine 2HCl and epichlorohydrin). Similarly, cytosolic reduction of chromium(VI) was partially inhibited by selective metabolic depletors of both coenzymes of DT-diaphorase, i.e., NADPH and NADH. Pretreatment of rats with enzyme inducers (phenobarbital and 3-methylcholanthrene) stimulated the activity of DT-diaphorase in liver cytosolic fractions. A dramatic stimulation (35 to 40 times over untreated controls) was produced by Aroclor 1254, which also coinduced the liver cytosolic activity of enzymes involved in the glucose 6-phosphate-dependent pathway of both nicotinamide-adenine-dinucleotide phosphate and glutathione reduction (glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, and glutathione reductase). In the lung cytosol, a slight yet significant stimulation of some of these enzyme activities was determined by the daily intratracheal instillations of high doses of chromium(VI) itself for 4 weeks, a condition which has been found to enhance the pulmonary metabolism of this metal ion.


Assuntos
Cromo/metabolismo , Mutagênicos/metabolismo , NADH NADPH Oxirredutases/fisiologia , Quinona Redutases/fisiologia , Animais , Citosol/enzimologia , Glutationa/farmacologia , Temperatura Alta , Concentração de Íons de Hidrogênio , Técnicas In Vitro , Cinética , Fígado/enzimologia , Pulmão/enzimologia , Masculino , Microssomos/metabolismo , NAD/farmacologia , NADP/farmacologia , Oxirredução , Quinona Redutases/antagonistas & inibidores , Ratos , Ratos Endogâmicos , Fatores de Tempo
19.
Rev. cir. (Impr.) ; 73(2): 158-165, abr. 2021.
Artigo em Espanhol | LILACS | ID: biblio-1388809

RESUMO

Resumen Introducción: La incorporación de tecnologías en la práctica quirúrgica, ha cambiado la forma de enfrentar el proceso quirúrgico. Objetivo: Describir la experiencia de los últimos 9 años, en cirugía ortognática, con la incorporación de la cefalometría 3D. Materiales y Método: Se realizó una revisión retrospectiva de pacientes operados de cirugía ortognática durante el período enero de 2011 a agosto de 2018. Se registraron datos demográficos, quirúrgicos, tipo de planificación quirúrgica, complicaciones y resultados a largo plazo. Resultados: 21 pacientes requirieron cirugías ortognáticas. Se realizaron 16 cirugías bimaxilares (76%), 3 cirugías de avance maxilar superior (14%) y 2 cirugías de osteotomía sagital de rama (10%). Las principales etiologías fueron: 67% maloclusión clase III (n = 14), 28% maloclusión clase II (n = 6) y 5% desviación mandibular (n = 1). La planificación prequirúrgica virtual fue utilizada en 11 pacientes (52%). La tasa de complicaciones Clavien-Dindo > III fue 4,8% (n = 1). Conclusiones: En nuestra experiencia, las técnicas de cirugía ortognática son seguras. Las complicaciones de la serie fueron escasas y bien toleradas por los pacientes. Durante los últimos años y, de acuerdo a los avances tecnológicos, la incorporación de la planificación quirúrgica virtual 3D favoreció el desarrollo de la cirugía ortognática en nuestro centro.


Introduction: Technological advances have been incorporated into cranio-maxillo-facial surgery changing the clinical practice of surgeons. Aim: The aim of this article is to describe our experience in orthognatic surgery in the last 9-years, with the incorporation of 3D cephalometry. Materials and Method: A retrospective chart review was performed from January 2011 to August 2018 on patients undergoing Orthognatic Surgery. Demographic and surgical data, type of surgical planning, complications and long-term results were recorded. Results: A total of 21 patients underwent orthognatic surgery. Average age was 28 years (DE 8.1), 11 men (52.3%) and 10 women (47.61%). The principal surgeries performed were: 16 (76%) bimaxillary, 3 maxillary advancement surgery 3 (14%) and bilateral sagital split osteotomy 2 (10%). Ethiologies were: 14 patients (this 67%) with malocclusion class III, 6 patients (28%) with malocussion class II, and 1 patient (5%) with mandibular deviation. Virtual 3D presurgical planning was used in 11 patients (52%). The total of complications Clavien-Dindo > III was 4.8% (n = 1). None patient required reoperation. Satisfaction rate with the procedure was high. Conclusions: Based on our experience, orthognatic surgery techniques are safe. The complication rate was lower and well tolerated by patients. The introduction of virtual planning provided a better scenario to develop maxillo-facial surgery.


Assuntos
Humanos , Imageamento Tridimensional/métodos , Cirurgia Ortognática/métodos , Cirurgia Ortognática/tendências , Resultado do Tratamento , Imageamento Tridimensional/tendências , Procedimentos Cirúrgicos Ortognáticos/métodos , Mandíbula/cirurgia
20.
Oncogene ; 20(28): 3683-94, 2001 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-11439331

RESUMO

In man, activated N-, K- and H-ras oncogenes have been found in around 30% of the solid tumours tested. An exon known as IDX, which has been described previously and is located between exon 3 and exon 4A of the c-H-ras pre-mRNA, allows an alternative splicing process that results in the synthesis of the mRNA of a putative protein named p19. It has been suggested that this alternative pathway is less tumorigenic than that which results in the activation of p21. We have used the mammalian trans-splicing mechanism as a tool with which to modulate this particular pre-mRNA processing to produce mRNA similar to that of mature p19 RNA. The E4A exon of the activated H-ras gene was found to be a good target for external trans-splicing. We reprogrammed the rat carnitine octanoyltransferase exon 2 to specifically invade the terminal region of H-ras. Assays performed with this reprogrammed trans-exon showed that the trans-splicing product was obtained in competition with cis-splicing of the D intron of the H-ras gene, and was associated with concomitant down-modulation of D intron cis-splicing. We also found that the exon 4A of the human c-H-ras gene underwent successive trans-splicing rounds with an external exon.


Assuntos
Regulação Neoplásica da Expressão Gênica , Genes ras , Trans-Splicing , Animais , Elementos Facilitadores Genéticos , Éxons , Células HeLa , Humanos , Íntrons , Ratos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA