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AIMS: This study investigated the diversity of Colletotrichum isolates recovered from Conyza bonariensis leaves through the use of morphological characteristics, growth rate, carbon sources utilization and phylogenetic analysis. METHODS AND RESULTS: In all, 30 Colletotrichum isolates recovered from C. bonariensis leaves showing symptoms of disease were included in the present study. Based on the analysis of morphology and sequences, the isolates were distributed into six Colletotrichum species complexes. The concatenated alignment of GAPDH and ITS sequences showed that 20 out of 30 isolates were included in four species complexes which comprise the most important pathogens causing anthracnose in soybean or anthracnose and stalk rot in maize: C. truncatum, C. orchidearum, C. gloeosporioides and C. graminicola. The remaining 10 isolates were included in the C. boninense and C. destructivum species complexes or could not be assigned to any complex with the available information. CONCLUSION: Weeds belonging to genus Conyza are host to soybean and maize potential pathogenic species of Colletotrichum and could have a role as inoculum reservoir for cross contamination in the agroecosystem. SIGNIFICANCE AND IMPACT OF THE STUDY: The combined use of morphological, kinetics and physiological parameters of growth and phylogenetic analysis in Colletotrichum isolates from Conyza leaves allowed the detection of species complexes previously not identified in Argentina.
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Colletotrichum/classificação , Colletotrichum/fisiologia , Conyza/microbiologia , Doenças das Plantas/microbiologia , Argentina , Carbono/metabolismo , Colletotrichum/isolamento & purificação , DNA Fúngico , Proteínas Fúngicas/genética , Gliceraldeído-3-Fosfato Desidrogenases/genética , Filogenia , Análise de Sequência de DNA , Glycine max/microbiologia , Zea mays/microbiologiaRESUMO
Objective: The aim of the study was to investigate endothelial function in treatment-naïve polymyalgia rheumatica (PMR) patients and its modification during steroid therapy, in relation to changes in clinical and laboratory parameters.Method: This prospective observational study involved patients with a new diagnosis of PMR according to provisional American College of Rheumatology/European League Against Rheumatism 2012 criteria, who were naïve to steroid therapy, and control subjects matched for age, gender, and comorbidities. All participants underwent clinical and vascular ultrasound evaluations at baseline and after 1, 3, 6, and 12 months of steroid therapy. For the study of endothelial function, we evaluated the brachial artery reactivity, which has emerged as the most well-established technique used in adults, by assessing flow-mediated dilatation (FMD), which measures the endothelium-dependent vasodilatation.Results: Sixteen newly diagnosed PMR patients were compared with a population of 16 matched controls. FMD values in all subjects showed an inverse correlation with the values of erythrocyte sedimentation rate and C-reactive protein. At baseline, the FMD of PMR patients was significantly lower than controls and remained significantly lower with respect to controls until the sixth month of therapy, despite a clinical improvement already being evident after 1 month of therapy.Conclusions: PMR is characterized by an important chronic subclinical inflammatory component. This pilot study demonstrates that affected patients show endothelial dysfunction that slowly responds to steroid therapy. Further studies are needed to investigate the clinical relevance of these observations and, in particular, to monitor the cardiovascular risk profile of PMR patients.
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Aterosclerose/etiologia , Artéria Braquial/fisiopatologia , Endotélio Vascular/fisiopatologia , Polimialgia Reumática/complicações , Vasodilatação/fisiologia , Idoso , Aterosclerose/diagnóstico , Aterosclerose/fisiopatologia , Artéria Braquial/diagnóstico por imagem , Endotélio Vascular/diagnóstico por imagem , Feminino , Seguimentos , Glucocorticoides/uso terapêutico , Humanos , Masculino , Projetos Piloto , Polimialgia Reumática/tratamento farmacológico , Polimialgia Reumática/fisiopatologia , Estudos Prospectivos , Ultrassonografia Doppler em CoresRESUMO
Northern corn leaf blight (NCLB) caused by Exserohilum turcicum is an endemic foliar disease in the Argentinean maize production area. Before applying a control method, it is essential to focus on factors that lead to the survival and conservation of E. turcicum inoculum. However, there is little information about the life cycle of this emerging pathogen in our country. The objective of the present work was to analyse the growth ability of three E. turcicum isolates under different type and conditions of maize, wheat and soybean residues, matric potential, temperature and their interactions. Statistical analysis demonstrated a significant effect of three factors on growth rate: residues-based media, matric potential and temperature. Among them the major effect was produced by matric potential followed by temperature. Although there were no significant differences in the growth rate among different residues types, the range of conditions in which growth occurred was different. According to these results, soybean residues would allow a better survival of E. turcicum inoculum under no-tillage system and providing an inoculum source for maize infections in subsequent year. SIGNIFICANCE AND IMPACT OF THE STUDY: Exserohilum turcicum is an emerging pathogen in Argentina that has caused significant economic losses in different maize growing areas. However, at present there is a lack of information about the life cycle of this fungal pathogen. The present study shows the influence of abiotic factors such as temperature and water potential on the growth of E. turcicum on different crop residues used in rotations with maize under no-till system cultivation. According to our results, soybean residues allowed the pathogen growth in a wider range of conditions compared to wheat and maize residue, providing an inoculum source for maize infections in subsequent season.
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Ascomicetos/crescimento & desenvolvimento , Glycine max/microbiologia , Doenças das Plantas/microbiologia , Triticum/microbiologia , Zea mays/microbiologia , Argentina , Ascomicetos/classificação , Ascomicetos/isolamento & purificação , Microbiologia do Solo , TemperaturaRESUMO
OBJECTIVE: The role of inflammatory markers as neutrophil-to-lymphocyte ratio (NLR), monocyte-to-high-density lipoprotein-cholesterol ratio (MHR), and platelet-to-lymphocyte ratio (PLR) in cardiovascular diseases has been widely investigated in recent years. In the context of lower extremity arterial disease (LEAD), this association has been mainly studied in the advanced stages. The aim of our study was to investigate the role of these inflammatory markers in all stages of LEAD, including early ones, using ultrasonography as diagnostic tool, together with ankle-brachial index (ABI) determination. PATIENTS AND METHODS: In this cross-sectional observational study, we enrolled 240 patients undergoing ultrasonographic evaluation of the lower limb arteries and ABI determination because of symptoms suggestive of LEAD or presence of known cardiovascular risk factors. RESULTS: In our study population, we found that ultrasonographic categories of LEAD were associated with NLR, but not with MHR and PLR. CONCLUSIONS: These results confirm that a specific pattern of inflammation can be found in all stages of LEAD, including early ones.
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Extremidade Inferior/diagnóstico por imagem , Doença Arterial Periférica/diagnóstico por imagem , Ultrassonografia , Idoso , Índice Tornozelo-Braço , Estudos Transversais , Feminino , Humanos , Contagem de Linfócitos , MasculinoRESUMO
AIMS: To assess the impact of Bacillus amyloliquefaciens and Microbacterium oleovorans on bacterial and fungal groups associated to the roots of field-grown maize. METHODS AND RESULTS: Identification and count of bacterial and fungal culturable populations associated to the roots of maize seedlings, changes in culturable community structure according to the richness and diversity indexes concept and shifts in microbial activity through analysis of cellulolytic, ammonification and nitrification potentials were determined, in relation to kernel treatment with biological control agents. Following the treatment of maize kernels with B. amyloliquefaciens at 10(7) CFU ml(-1), an increase in bacterial diversity was observed at the rhizoplane of resultant seedlings. Bacterial richness was significantly increased at the root inner tissues of seedlings treated with Mic. oleovorans. Fusarium, Aspergillus, Penicillium and Trichoderma were the main fungal genera isolated and there population sizes were unequally affected by the addition of biocontrol agents. CONCLUSIONS: Numbers and types of isolated bacteria and fungi changed in response to the addition of biocontrol agents, while microbial activity remained unchanged with respect to control. SIGNIFICANCE AND IMPACT OF THE STUDY: This study provides an insight of the effects of proven biocontrol agents on micro-organisms naturally associated to the target crop.
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Actinomycetales/crescimento & desenvolvimento , Bacillus/crescimento & desenvolvimento , Bactérias/crescimento & desenvolvimento , Fungos Mitospóricos/crescimento & desenvolvimento , Controle Biológico de Vetores , Raízes de Plantas/microbiologia , Zea mays/microbiologia , Bactérias/classificação , Contagem de Colônia Microbiana , Meios de Cultura , Fungos Mitospóricos/classificação , Doenças das Plantas/microbiologia , Plântula/crescimento & desenvolvimento , Microbiologia do SoloRESUMO
A third-generation enzymatic biosensor was developed to quantify sterigmatocystin (STEH). It was based on a glassy carbon electrode modified with a composite of the soybean peroxidase enzyme (SPE) and chemically reduced graphene oxide. The optimal conditions to construct the biosensor were obtained through an experimental design based on the response surfaces methodology. The experiments were performed in 0.1â¯molâ¯L-1 phosphate buffer solution, pH 5. Amperometric measurements were carried out at -â¯0.09â¯V vs Ag/AgCl (3â¯molâ¯L-1 NaCl). The biosensor showed a lineal response in the concentration range from 6.9â¯×â¯10-9 to 5.0â¯×â¯10-7 molâ¯L-1. The limit of detection was 2.3â¯×â¯10-9 molâ¯L-1 for a signal: noise ratio of 3: 1. Values of the apparent Michaellis-Menten constant, KMapp, obtained by using both Lineweaver-Burk and Eadi-Hofstee methods were (1.5 ± 0.2) × 10-6 and (1.2 ± 0.2) × 10-6 mol L-1, respectively. STEH was analyzed in corn samples spiked with STEH, with an average recovery of 96.5%. The biosensor was also used to determine STEH in corn samples inoculated with the Aspergillus flavus fungus, which is an aflatoxins producer. Considering that STEH is a precursor of aflatoxin B1 (AFB1) in its biological transformation, its decrease over time was related to the production of AFB1. The STEH concentration determined using the biosensor was in very good agreement with that determined by HPLC.
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Aflatoxina B1/análise , Técnicas Biossensoriais/métodos , Peroxidase/metabolismo , Esterigmatocistina/análise , Técnicas Biossensoriais/instrumentação , Carbono/química , Eletroquímica , Eletrodos , Limite de Detecção , Glycine max/enzimologia , Zea mays/químicaRESUMO
Low molecular weight heparins (LMWH) are a class of drugs including various molecules that inhibit predominantly the factor V of coagulation and are used in a wide range of clinical settings for the management of venous thromboembolism and acute coronary syndrome. Despite LMWH are considered safe and associated with a lower incidence of side effects compared to unfractioned heparin, it is worth considering that the use of LWMH can be associated with complications. Some of these, such as bleeding and thrombocytopenia, are well-known, whereas other ones are often underestimated leading to a diagnostic delay. In this case report, we describe a case of a 73-years-old man who recently started nadroparin for deep vein thrombosis presenting with acute hepatitis. The diagnostic workup of drug-induced liver injury (DILI) requires the exclusion of other causative agents and temporal association between the initiation of the culprit drug and hyper aminotransferasemia. This clinical case analyzes how to deal with a suspicion of DILI and consider LWMH as a potential cause of DILI, which requires a modification of the anticoagulant treatment.
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Anticoagulantes/efeitos adversos , Doença Hepática Induzida por Substâncias e Drogas/diagnóstico , Heparina de Baixo Peso Molecular/efeitos adversos , Doença Aguda , Idoso , Anticoagulantes/uso terapêutico , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Heparina de Baixo Peso Molecular/uso terapêutico , Hepatite/complicações , Humanos , Masculino , Trombose Venosa/complicações , Trombose Venosa/tratamento farmacológicoRESUMO
Amplitude and phase measurements of the near-field generated by isolated subwavelength apertures in a gold film are presented. The near-field distribution of such a structure is complex and the measured signal strongly depends on the electric field components effectively detected by the experimental setup. By comparing this signal with 3D vectorial calculations we are able to determine which electric field components are effectively measured. The sensitivity of the phase distribution is key to this measurement. The proposed characterization technique should prove extremely useful to calibrate a Scanning near-field optical microscopy (SNOM) beforehand in order to retrieve quantitative information on the polarization of the field distribution under study.
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OBJECTIVE: To quantify non-coronary vascular calcifications (VC) in asymptomatic patients at low-intermediate cardiovascular risk by a new color Doppler ultrasound (DUS)-based score (the carotid, aortic, lower limbs calcium score, CALCs), and to correlate this score with classical parameters associated with cardiovascular risk [carotid intima media thickness (IMT), and arterial stiffness (AS)]. PATIENTS AND METHODS: All consecutive asymptomatic patients who underwent a screening DUS of non-coronary circulation were evaluated and patients at low-intermediate cardiovascular risk were selected according to Framingham risk score (FRS). Among them, we enrolled 70 patients with US evidence of VC and 71 age, sex and FRS matched controls. The presence of VC was correlated with classical markers of cardiovascular risk, such as AS and intima-media thickness (IMT). AS, expressed as pulse wave velocity (PWV) and arterial distensibility, carotid IMT and CALCs were measured for both groups. AS and c-IMT were assessed by a new Radio-Frequency (RF) DUS-based method. CALCs was generated by our previously described B-mode DUS-based method according to number/size of VC in 11 non-coronary segments (range 0-33). RESULTS: Patients with VC presented higher AS and IMT values than controls (PWV 8.34±0.98 m/s vs. 6.74±0.68 m/s, p<0.0001; arterial distensibility 267±12 mm vs. 315±65 mm, p=0.001; IMT 687±132 mm vs. 572±91 mm, p<0.0001). Mean CALCs of patients with VC was 8.41±7.78. CALCs were significantly correlated with c-IMT (p<0.0001; r=0.3), PWV (p<0.0001; r=0.4) and arterial distensibility (p=0.002; r=-0.1). CONCLUSIONS: DUS-based CALCs is highly correlated with other validated markers of subclinical atherosclerosis, such as c-IMT and AS. Our results demonstrated the ability of CALCs to identify individual predictive factors beyond the traditional risk factors by quantifying an interesting and novel step of the atherogenic process. Future studies on larger series and with adequate follow up are necessary to confirm these results and to evaluate the role of this new marker in monitoring calcific atherosclerosis progression.
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Aterosclerose/diagnóstico por imagem , Ultrassonografia Doppler em Cores/métodos , Calcificação Vascular/diagnóstico por imagem , Adulto , Idoso , Aterosclerose/fisiopatologia , Espessura Intima-Media Carotídea/efeitos adversos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Análise de Onda de Pulso/métodos , Fatores de Risco , Calcificação Vascular/fisiopatologia , Rigidez Vascular/fisiologiaRESUMO
OBJECTIVE: Most studies on atherosclerotic processes include peripheral arterial disease diagnosis only if patients report symptoms suggestive of peripheral arterial disease and/or an instrumental demonstration of lower limbs perfusion deficit is provided, rather than the sole presence of atherosclerotic lesions localized at lower limbs, this attitude leading to ignore early stages of the disease. To overcome these limitations, we have proposed a new ultrasonographic semiquantitative score to better identify all disease stages. The aim of this study is to compare ultrasonography versus ankle-brachial index in the association between peripheral arterial disease and cardiovascular risk factors. PATIENTS AND METHODS: This cross-sectional observational study included subjects undergoing lower limbs evaluation through ultrasonography and ankle-brachial index determination because of symptoms suggestive of peripheral arterial disease or presence of known cardiovascular risk factors. Associations between ultrasonography and ankle-brachial index with cardiovascular risk factors were assessed by first fitting logistic regression models and then comparing the respective areas under the Receiver Operating Characteristic and 95% confidence intervals. RESULTS: The areas under the Receiver Operating Characteristic for each cardiovascular risk factors were consistently larger in magnitude for ultrasonography compared with ankle-brachial index, this comparison being statistically significant for age, male gender, smoking status, hypertension, diabetes mellitus and previous cardiovascular events. CONCLUSIONS: Our study demonstrates that ultrasonography is a better method to screen peripheral arterial disease respect to ankle-brachial index in order to identify all disease stages. These findings are useful in particular when including peripheral arterial disease as organ damage marker in cardiovascular risk stratification.
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Índice Tornozelo-Braço , Doenças Cardiovasculares/diagnóstico , Doença Arterial Periférica/diagnóstico , Ultrassonografia , Adulto , Idoso , Doenças Cardiovasculares/complicações , Sistema Cardiovascular , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Doença Arterial Periférica/complicações , Fatores de RiscoRESUMO
Ornithine decarboxylase (ODC) is the key enzyme in the synthesis of polyamines, small cationic molecules believed to have a role in many cellular processes such as cell migration, proliferation and differentiation. We show that ODC expression is associated with cell proliferation and commitment in hair follicle development and hair growth. In embryonic epidermis, ODC is expressed in ectodermal cells at sites where follicles develop, and persists in cells at the leading edge of the follicle placode. ODC is abundantly expressed in proliferating bulb cells of anagen follicles, except for a pocket of cells at the base of the bulb. Entry of the follicle into catagen is accompanied by a down-regulation of ODC expression, which is not resumed until a new follicle is initiated. In vibrissae, ODC expression is more complex. ODC is expressed not only in the bulb but also in the hair shaft, presenting a striking biphasic pattern. Additionally, ODC is expressed in a group of outer root sheath cells in the vicinity of the follicle bulge, the putative site of hair follicle stem cells.
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Regulação da Expressão Gênica no Desenvolvimento , Folículo Piloso/embriologia , Cabelo/enzimologia , Ornitina Descarboxilase/genética , Ornitina Descarboxilase/metabolismo , Animais , Divisão Celular , Cabelo/citologia , Cabelo/crescimento & desenvolvimento , Folículo Piloso/enzimologia , Histonas/genética , Histonas/metabolismo , Queratinócitos/enzimologia , CamundongosRESUMO
The Notch signalling pathway is an important mediator of cell fate selection whose involvement in epidermal appendage formation is now becoming recognised. Hair follicle development and hair formation involve the co-ordinated differentiation of several different cell types in which Notch appears to have a role. We report intricate expression patterns for the Notch-1 receptor and three ligands, Delta-1, Jagged-1 and Jagged-2 in the hair follicle. Notch-1 is expressed in ectodermal-derived cells of the follicle, in the inner cells of the embryonic placode and the follicle bulb, and in the suprabasal cells of the mature outer root sheath. Delta-1 is only expressed during embryonic follicle development and is exclusive to the mesenchymal cells of the pre-papilla located beneath the follicle placode. Expression of Jagged-1 or Jagged-2 overlaps Notch-1 expression at all stages. In mature follicles, Jagged-1 and Jagged-2 are expressed in complementary patterns in the follicle bulb and outer root sheath, Jagged-1 in suprabasal cells and Jagged-2 predominantly in basal cells. In the follicle bulb, Jagged-2 is localised to the inner (basal) bulb cells next to the dermal papilla which do not express Notch-1, whereas Jagged-1 expression in the upper follicle bulb overlaps Notch-1 expression and correlates with bulb cell differentiation into hair shaft cortical and cuticle keratinocytes.
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Folículo Piloso/metabolismo , Cabelo/crescimento & desenvolvimento , Proteínas de Membrana/fisiologia , Receptores de Superfície Celular , Transdução de Sinais/fisiologia , Fatores de Transcrição , Vibrissas/crescimento & desenvolvimento , Animais , Proteínas de Ligação ao Cálcio , Proteínas de Transporte/fisiologia , Diferenciação Celular , Ectoderma/metabolismo , Hibridização In Situ , Peptídeos e Proteínas de Sinalização Intercelular , Peptídeos e Proteínas de Sinalização Intracelular , Proteínas de Membrana/biossíntese , Proteínas de Membrana/genética , Mesoderma/metabolismo , Proteínas/fisiologia , Receptor Notch1 , Proteínas Serrate-JaggedRESUMO
BACKGROUND: Carotid intima-media thickness (c-IMT), arterial stiffness (AS) and vascular calcification (VC) are now considered important new markers of atherosclerosis and have been associated with increased prevalence of cardiovascular events. An accurate, reproducible and easy detection of these parameters could increase the prognostic value of the traditional cardiovascular risk factors in many subjects at low and intermediate risk. Today, c-IMT and AS can be measured by ultrasound, while cardiac computed tomography is the gold standard to quantify coronary VC, although concern about the reproducibility of the former and the safety of the latter have been raised. Nevertheless, a safe and reliable method to quantify non-coronary (i.e., peripheral) VC has not been detected yet. AIM: To review the most innovative and accurate ultrasound-based modalities of c-IMT and AS detection and to describe a novel UltraSound-Based Carotid, Aortic and Lower limbs Calcification Score (USB-CALCs, simply named CALC), allowing to quantify peripheral calcifications. Finally, to propose a system for cardiovascular risk reclassification derived from the global evaluation of "Quality Intima-Media Thickness", "Quality Arterial Stiffness", and "CALC score" in addition to the Framingham score.
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Doenças Cardiovasculares/diagnóstico por imagem , Espessura Intima-Media Carotídea , Ultrassonografia Doppler de Pulso/tendências , Calcificação Vascular/diagnóstico por imagem , Rigidez Vascular , Aterosclerose/diagnóstico por imagem , Doenças das Artérias Carótidas/diagnóstico por imagem , Vasos Coronários/diagnóstico por imagem , Humanos , Reprodutibilidade dos Testes , Fatores de Risco , Ultrassonografia Doppler de Pulso/normasRESUMO
OBJECTIVE: To analyze serum biomarkers of CVD in selected patients with primary axial reflux of great saphenous vein in one or both lower limbs. PATIENTS AND METHODS: Ninety-six patients affected by uncomplicated varicose veins, were enrolled in the study. A unilateral, primary axial reflux in great saphenous veins was detected in 54 patients (U-CVD group) and a bilateral one in 42 (B-CVD group). Sixty-five age and sex-matched subjects without venous reflux were enrolled as controls. Mean venous pressure of both lower limbs at the distal great saphenous vein (mGSVP) and venous reflux were measured by continuous-wave Doppler ultrasound and echoduplex scanning, respectively. Reactive Oxygen Species (ROS), tissue Plasminogen Activator (t-PA) and its Inhibitor 1 (PAI-1) activities, Hematocrit (HTC), White Blood Cells (WBC), Neutrophyls (NEU), Platelets (PLT), Fibrinogen (FIB) and Blood Viscosity (BV) were assessed in blood samples drawn from the antecubital vein. RESULTS: B-CVD group showed higher fibrinogen values (p < 0.005) and higher mean venous pressure (0 < 0.0001) in comparison to controls, while U-CVD did not. No difference was found between both groups and controls for all the other parameters. CONCLUSIONS: Increased fibrinogen levels in patients with bilateral varicose veins may represent an early warning signal, as it could be associated to the long-term progression of chronic venous disease.
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Biomarcadores/sangue , Extremidade Inferior/irrigação sanguínea , Varizes/sangue , Vasculite/sangue , Adulto , Estudos de Casos e Controles , Doença Crônica , Progressão da Doença , Feminino , Humanos , Inflamação/sangue , Inflamação/diagnóstico por imagem , Extremidade Inferior/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Veia Safena/diagnóstico por imagem , Veia Safena/patologia , Ultrassonografia Doppler Dupla , Varizes/complicações , Varizes/diagnóstico por imagem , Vasculite/complicações , Vasculite/diagnóstico por imagemRESUMO
A unique type I keratin intermediate filament group, comprising three highly related proteins and expressed in the inner root sheath of hair follicles, has been identified in both sheep and human. The first members from these species are named oIRSa1 and hIRSa1 and each encodes a protein of 450 amino acids, with compositional characteristics intermediate between those of previously described hair keratin and epidermal cytokeratin type I intermediate filaments. Detection of abundant mRNA transcripts derived from the sheep and human genes by cRNA in situ hybridization only in the inner root sheath and not in the medulla concurs with the findings of earlier ultrastructural analyses that have reported intermediate filaments only in the inner root sheath. Clustering of the IRSa keratin genes is apparent in the genomes of both species. The three hIRSa genes, known to reside on human chromosome 17, are closely linked to three further type I keratin intermediate filament genes of unknown function. This new gene complex, contained almost entirely within a 156 kb BAC (hRPK.142_H_19), is likely to lie near the type I intermediate filament cytokeratin and hair keratin gene loci at 17q12-q21. A phylogenetic analysis including all known human type I intermediate filament cytokeratins, hHa keratins, hIRSa, and hIRSa-linked keratins suggests that origin of the IRSa keratin intermediate filament linkage group preceded origin of most of the epidermal cytokeratins and all hair keratins during emergence of the keratin intermediate filament genes.
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Folículo Piloso/metabolismo , Filamentos Intermediários/genética , Queratinas/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Expressão Gênica , Humanos , Hibridização In Situ , Camundongos , Dados de Sequência Molecular , Couro Cabeludo/química , Ovinos , Pele/química , Distribuição Tecidual/genética , Língua/químicaRESUMO
We have cloned ovine Barx2, a member of the Bar class of homeobox genes, and present the first description of Barx2 expression in wool follicle development. Barx2 is uniformly expressed in the embryonic ectoderm but is transiently downregulated during the initiation of follicle morphogenesis. Subsequently, Barx2 is expressed throughout the epithelial component of the developing follicle except for a small group of cells at the leading edge of the follicle placode. These Barx2-negative cells are destined to form the follicle bulb and are the progenitors of the inner root sheath and hair shaft. In adult follicles, Barx2 is expressed throughout the outer root sheath but not in the inner root sheath or hair shaft, or in dermal cells associated with the follicle. The pattern of Barx2 expression in follicle morphogenesis is similar to that of the cell adhesion molecule E-cadherin, a similarity that echoes Barx2 coexpression with the L1 cell adhesion molecule in other tissues during mouse embryogenesis. Barx2 is also expressed in tongue and esophagus, two other keratinizing tissues, and we speculate that Barx2 may have a general function in controlling adhesive processes in keratinizing epithelia.
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Genes Homeobox/genética , Folículo Piloso/crescimento & desenvolvimento , Proteínas de Homeodomínio/genética , Animais , Sequência de Bases , Clonagem de Organismos , Expressão Gênica , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Ovinos , Lã/crescimento & desenvolvimentoRESUMO
In hair growth, as the follicle bulb cells rapidly differentiate into either cortical or cuticle hair keratinocytes, about 50-100 keratin genes are transcriptionally activated. However, this complexity can be reduced to several, highly conserved gene families. In studying the regulation of keratin gene expression in the hair follicle we have isolated genes from most of these families and have examined their expression patterns by in situ hybridization. In the cortical keratinocytes striking patterns of keratin gene expression exist, suggesting that different transcriptional hierarchies operate in the various cell types. Comparisons of the keratin gene promoter regions indicates conserved sequence motifs that could be involved in determining these cell specificities. Similarly, we have isolated related sheep and human cuticle keratin genes and find conserved DNA motifs and expression patterns in cuticle cell differentiation. Additionally, the expression of sheep wool follicle IF and high-sulfur keratin genes in transgenic mice suggests that the regulatory DNA elements and proteins of hair keratin genes are functionally conserved between mammals.
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Regulação da Expressão Gênica , Cabelo/fisiologia , Queratinas/genética , Animais , Sequência de Bases , Diferenciação Celular , Cabelo/anatomia & histologia , Cabelo/citologia , Humanos , Queratinócitos/citologia , Queratinócitos/fisiologia , Dados de Sequência Molecular , Regiões Promotoras Genéticas , TATA BoxRESUMO
The aims of this study were to compare the viability and biomass production of B. amyloliquefaciens and M. oleovorans in different growth media, and the efficiency of a freeze-drying method as a possible formulation process. B. amyloliquefaciens and M. oleovorans were grown in 100 ml of four different media. Media water activity was modified at 0.99, 0.98, 0.97 and 0.96. Nutrient yeast dextrose broth (NYDB) and molasses soy powder (MSB) media were selected and survival levels of cells were determined before and after the freeze-drying process. B. amyloliquefaciens showed the highest survival after freeze-drying when grown in NYDB medium at 0.99 a(w), whereas, at 0.98, 0.97 and 0.96 a(w), the highest survival was obtained in MSB medium. M. oleovorans showed the highest survival in MSB medium at 0.99 a(w). MSB medium was select for biomass production due to high growth and survival after freeze-drying.
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Actinobacteria/fisiologia , Bacillus/classificação , Bacillus/fisiologia , Fusarium/fisiologia , Biomassa , Liofilização , Controle Biológico de Vetores/métodosRESUMO
Amoxicillin (Amx) and cephalexin (Cfx) are ß-lactam antibiotics widely used in human and veterinary medicine. Two points of interest surrounding these molecules are the photodegradation of the molecules and their microbiological implications, as well as the persistence and bioaccumulation in the environment which may cause resistance to bacterial strains. The kinetic and mechanistic aspects of the photosensitized degradation of Amx and Cfx have been studied in water at pH 7.4 and 10 by stationary and time-resolved methods. Kinetic evidence indicates that the Rose Bengal-sensitized photooxidation of Amx at pH 7.4 proceeds via O(2)((1)Δ(g)) and O(2â¢-) mechanisms while at pH 10 the degradation path occurs, principally, via O(2)((1)Δ(g)). For Cfx, this process is attributed to O(2)((1)Δ(g)) and O(2â¢-). Photoproducts, which arise from the addition of oxygen atoms and subsequent oxidation of the groups -CH(3) to -COOH, were detected. For both antibiotics the bacteriostatic activity decreases in parallel to their photodegradation. The results of this study could potentially help scientists to better understand and predict the photodegradability of these antibiotics on living organisms and in different environmental compartments.
Assuntos
Amoxicilina/efeitos da radiação , Antibacterianos/efeitos da radiação , Cefalexina/efeitos da radiação , Amoxicilina/química , Amoxicilina/farmacologia , Antibacterianos/química , Antibacterianos/farmacologia , Cefalexina/química , Cefalexina/farmacologia , Cromatografia Líquida de Alta Pressão , Resíduos de Drogas , Microbiologia Ambiental , Concentração de Íons de Hidrogênio , Cinética , Testes de Sensibilidade Microbiana , Oxirredução , Fenalenos/farmacologia , Fotólise , Fármacos Fotossensibilizantes/farmacologia , Rosa Bengala/farmacologia , Oxigênio Singlete/química , Soluções , Espectrofotometria , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento , Superóxidos/química , ÁguaRESUMO
Natural phytochemicals may be an alternative to synthetic chemicals for controlling fungal growth and mycotoxin production in stored maize. A key to progress in this field is to select the best natural maize phytochemicals to be applied in a storage maize ecosystem. This research was undertaken to evaluate the effects of the natural phytochemicals trans-cinnamic acid (CA) and ferulic acid (FA) alone at concentrations of 20 to 30 mM and in 5 combinations on Aspergillus flavus Link and A. parasiticus Speare populations and aflatoxin B(1) production. Studies on Aspergillus population and aflatoxin B(1) production were carried out in maize grain in relation to a water activity a(w) of 0.99, 0.97, 0.95, and 0.93. CA and FA at concentrations of 25 to 30 mM, respectively, and CA-FA mixture T9 (25 + 30 mM) were the treatments most effective at inhibiting A. flavus and A. parasiticus population at all a(w) assayed after 11 d of incubation. At all a(w) values, the mixture CA-FA T9 (25 + 30 mM) completely inhibited (100%) aflatoxin B(1) production by both strains at a(w)= 0.99, 0.97, 0.95, and 0.93. Decreased aflatoxin B(1) levels in comparison with the control were observed with mixtures CA-FA T6 (10 + 25 mM), T7 (20 + 20 mM), and T8 (20 + 30 mM) of both strains in the majority of a(w) assayed. The data show that CA and FA could be considered as effective fungitoxicants for A. flavus and A. parasiticus in maize in the a(w) range 0.99 to 0.93. The information obtained shows promise for controlling aflatoxigenic fungi in stored maize.