Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 72
Filtrar
1.
Bull Environ Contam Toxicol ; 103(4): 515-520, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31143976

RESUMO

Concentration of essential (Se, Zn and Cu) and non-essential (As, Cd, Hg and Pb) trace elements were measured in selected tissues of two dead whale sharks (Rhincodon typus) stranded in the Gulf of California (GC) in 2017 and 2018. Concentrations of Cd and Pb in the skeletal muscle of the whale shark from La Paz Bay, GC were higher compared to a previous study on whale shark from China. The shark from La Paz Bay also presented higher concentration of Pb in the epidermis, compared to the same tissue of the other whale shark stranded in Punta Bufeo, GC. The Hg in all analysed tissues was lower than those documented in carnivorous sharks. Molar ratio Se:Hg shows an excess of Se over Hg in all the tissues sampled in both sharks.


Assuntos
Monitoramento Ambiental/métodos , Epiderme/química , Metais Pesados/análise , Músculo Esquelético/química , Tubarões/metabolismo , Oligoelementos/análise , Poluentes Químicos da Água/análise , Animais , Baías/química , México , Oceano Pacífico
2.
Osteoporos Int ; 28(7): 2239-2245, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28378290

RESUMO

In older adults, lower bone density in the proximal femur was associated with increased heart burden, and this association was linked to calcification in the aorta. These results were seen in women but not in men. PURPOSE: To determine whether there is an association between lower bone mineral density (BMD) and increased cardiac workload in older adults, and if this association was independent of abdominal aortic calcification (AAC). METHODS: Three hundred thirty-seven participants [mean ± SD age = 70 ± 5 years and BMI = 28 ± 5 kg/m2, 61% females] had BMD determined by dual-energy X-ray absorptiometry and AAC determined by radiography. Aortic calcification score (ACS) was determined visually in the L1-L4 vertebrae (range 0-24). Systolic blood pressure (BP) and heart rate (HR) were measured. The rate pressure product (RPP), a measure of cardiac workload, was determined by multiplying BP and HR. RESULTS: AAC was present in 205 (61%) participants. Mean ± SD RPP was 9120 ± 1823; range was 5424-18,537. In all participants, ACS was positively associated with log-transformed RPP [LnRPP] (ß = 0.011, p < 0.001), and severe calcification was positively associated with LnRPP (ß = 0.083, p = 0.004 relative to no calcification). In sex-stratified analyses, these associations were significant only in females. Lower odds of any AAC were observed per 1 g/cm2 increment in femoral neck BMD (OR = 0.08, 95% CI 0.01-0.95). A similar trend was evident in women separately (OR = 0.05, 95% CI 0-1.17) but not men. In all participants, femoral neck (ß = -0.20, p = 0.04) and total hip BMD (ß = -0.17, p = 0.04) were inversely associated with LnRPP after multivariate adjustment. Adjusting additionally for AAC reduced the strength of the association in femoral neck (ß = -0.19, p = 0.05) but not total hip BMD (ß = -0.17, p = 0.04). CONCLUSION: Lower BMD was marginally, but significantly with increased LnRPP, and this relationship was partially mediated by AAC suggesting that older adults, particularly females, with osteoporosis may have an increased cardiovascular risk.


Assuntos
Aorta Abdominal , Pressão Sanguínea/fisiologia , Densidade Óssea/fisiologia , Articulação do Quadril/fisiopatologia , Osteoporose/complicações , Calcificação Vascular/etiologia , Absorciometria de Fóton , Idoso , Antropometria/métodos , Aorta Abdominal/diagnóstico por imagem , Feminino , Colo do Fêmur/fisiopatologia , Frequência Cardíaca/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Osteoporose/epidemiologia , Osteoporose/fisiopatologia , Fatores Sexuais , Calcificação Vascular/diagnóstico por imagem , Calcificação Vascular/epidemiologia , Calcificação Vascular/fisiopatologia , Vitória/epidemiologia
3.
Clin Exp Dermatol ; 40(3): 298-300, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25557471

RESUMO

Idiopathic facial aseptic granuloma (IFAG) is a condition that is commonly encountered in clinical practice, but is rarely reported. It appears in childhood and its pathogenesis is still unknown. It has a benign course with resolution within a few months without aggressive treatment. Microbiological tests are negative and histological findings are nonspecific. It is possible that this condition is part of the spectrum of granulomatous rosacea in childhood. We present two cases in which diagnosis of IFAG was established and resolved without sequelae following topical antibiotic treatment.


Assuntos
Dermatoses Faciais/patologia , Granuloma/patologia , Adolescente , Criança , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Rosácea/patologia
4.
Environ Monit Assess ; 187(1): 4158, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25523271

RESUMO

The mining district of El Triunfo (ET-MD) has an estimated 800,000 t of mine wastes scattered in the environment, contaminating the sediment with potentially toxic elements such as As, Cd, Pb, and Zn. In order to estimate the toxicity of the sediment to the adjacent biota, the aims of our study are to calculate the mortality and inhibition through bioassays, using sediment, and test organisms such as Daphnia magna and Selenastrum capricornutum (Pseudokirchneriella subcapitata), respectively. The D. magna mortality was 31 ± 12% and the S. capricornutum growth inhibition was 53 ± 24%. The contamination of the sediment determines the high mortality of D. magna and the high inhibition of S. capricornutum in the system, indicating risk for the biota in the contaminated system.


Assuntos
Monitoramento Ambiental , Sedimentos Geológicos/análise , Mineração , Poluentes do Solo/toxicidade , Animais , Bioensaio , Clorófitas , Daphnia , Sedimentos Geológicos/química , Ouro , Poluentes do Solo/análise , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
5.
Actas Dermosifiliogr ; 106(5): 350-64, 2015 Jun.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-25638325

RESUMO

Intense pulsed light (IPL) systems have evolved since they were introduced into medical practice 20 years ago. Pulsed light is noncoherent, noncollimated, polychromatic light energy emitted at different wavelengths that target specific chromophores. This selective targeting capability makes IPL a versatile therapy with many applications, from the treatment of pigmented or vascular lesions to hair removal and skin rejuvenation. Its large spot size ensures a high skin coverage rate. The nonablative nature of IPL makes it an increasingly attractive alternative for patients unwilling to accept the adverse effects associated with other procedures, which additionally require prolonged absence from work and social activities. In many cases, IPL is similar to laser therapy in effectiveness, and its versatility, convenience, and safety will lead to an expanded range of applications and possibilities in coming years.


Assuntos
Terapia de Luz Pulsada Intensa , Dermatopatias/terapia , Remoção de Cabelo/métodos , Humanos , Terapia de Luz Pulsada Intensa/efeitos adversos , Terapia a Laser/efeitos adversos , Fotoquimioterapia , Lesões Pré-Cancerosas/tratamento farmacológico , Rejuvenescimento , Neoplasias Cutâneas/tratamento farmacológico , Neoplasias Cutâneas/terapia
6.
J Appl Microbiol ; 116(3): 586-95, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24206231

RESUMO

AIM: This study was aimed to investigate the influence of malolactic fermentation (MLF) on sensory profile and organoleptic characteristics of Albariño and Caiño white wines. METHODS AND RESULTS: Autochthonous bacteria were isolated from wines after alcoholic fermentation (AF) and further identified as Pediococcus damnosus by 16S rRNA gene sequence analysis. When a commercial Oenococcus oeni starter was inoculated into Albariño and Caiño white wines to perform MLF, which was checked by HPLC quantification of malic and lactic acids, it was shown that autochthonous Ped. damnosus strains were able to predominate over the commercial O. oeni starter and perform MLF in Caiño wine. By contrast, neither commercial strain nor indigenous Pediococcus carried out MLF in Albariño wine. However, MLF was achieved when autochthonous strains that predominated in Caiño were inoculated into Albariño. Sensory analysis showed that after the MLF Albariño increased its body and softness, while Caiño result a more mature wine. CONCLUSIONS: MLF can positively affect Albariño and Caiño wines giving them new attributes. Pediococci isolated and characterized in this work can successfully perform MLF without negative effects on the wine, because no production of biogenic amines or exopolysaccharides by the selected pediococcus strains was detected. SIGNIFICANCE AND IMPACT OF THE STUDY: The effect of MLF in the sensory profile of Albariño and Caiño wines has never been studied before. Results obtained in this work showed that Ped. damnosus strains can be considered as a new topic of investigation on malolactic starter.


Assuntos
Fermentação , Ácido Láctico/metabolismo , Malatos/metabolismo , Pediococcus/metabolismo , Vinho/microbiologia , Oenococcus/metabolismo , Pediococcus/isolamento & purificação , Vinho/análise
7.
Arch Esp Urol ; 67(2): 167-74, 2014 Mar.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-24691038

RESUMO

OBJECTIVES: Hemorrhagic cystitis (HC) presenting with gross hematuria, bladder pain and urinary frequency develops in 13-38% of patients following bone marrow transplantation (BMT). The objective of the study was to study the characteristics of patients suffering hemorrhagic cystitis after hematopoietic stem cell transplantation in our center. METHODS: We conducted a retrospective chart review of all patients who underwent BMT at our institution between January 1996 and August 2012. We recorded the age, sex, diagnosis, conditioning regimen, interval between BMT and development of symptoms of cystitis and treatment instituted. RESULTS: Five hundred patients underwent BMT in the period of time studied. 52 of them developed hemorrhagic cystitis. The mean age of the affected patients was 39 years; there were 34 males and 18 females. The diagnoses include AML (n=11), ALL (n=8), CML (n=6), MDS (n=11), CLL (n=5), NHL (n=1), HD (n=5), MM (n=2), Medular aplasia((n=3). HC appeared 59.48 days after BMT. There were no differences between sexes. Mortality among the 52 patients was 51.14% but HC was not the cause of death in any patient. Polyomaviruses were detected in the urine of 78.94 % of survivors. CONCLUSIONS: Polyomavirus infection with BK and JC types is usually acquired in infancy and the virus remains latent in renal tissue. Immunosuppression facilitates reactivation of the renal infection and replication of the virus responsible for the clinical manifestations of HC. The differential diagnoses include other urinary infections, lithiasis, thrombocytopenia and adverse effects of pharmacological agents. The urologist plays a limited role in the management of this disease.


Assuntos
Transplante de Medula Óssea/efeitos adversos , Cistite/etiologia , Hemorragia/etiologia , Adulto , Idoso , Feminino , Hematúria/etiologia , Humanos , Masculino , Pessoa de Meia-Idade , Dor/etiologia , Estudos Retrospectivos , Adulto Jovem
10.
J Chem Ecol ; 39(5): 653-65, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23609163

RESUMO

Plants growing under elevated CO2 concentration may acclimate by modifying chemical traits. Most studies have focused on the effects of environmental change on plant growth and productivity. Potential effects on chemical traits involved in resistance, and the consequences of such effects on plant-insect interactions, have been largely neglected. Here, we evaluated the performance of two Brassica specialist herbivores from contrasting feeding guilds, the leaf-feeding Pieris brassicae and the phloem-feeding Brevicoryne brassicae, in response to potential CO2-mediated changes in primary and major secondary metabolites (glucosinolates) in Brassica oleracea. Plants were exposed to either ambient (400 ppm) or elevated (800 ppm) CO2 concentrations for 2, 6, or 10 weeks. Elevated CO2 did not affect primary metabolites, but significantly increased glucosinolate content. The performance of both herbivores was significantly reduced under elevated CO2 suggesting that CO2-mediated increases in constitutive defense chemistry could benefit plants. However, plants with up-regulated defenses could also be subjected to intensified herbivory by some specialized herbivores, due to a chemically-mediated phagostimulatory effect, as documented here for P. brassicae larvae. Our results highlight the importance of understanding acclimation and responses of plants to the predicted increases in atmospheric CO2 concentrations and the concomitant effects of these responses on the chemically-mediated interactions between plants and specialized herbivores.


Assuntos
Afídeos/fisiologia , Brassica/efeitos dos fármacos , Borboletas/fisiologia , Dióxido de Carbono/farmacologia , Glucosinolatos/metabolismo , Herbivoria/fisiologia , Animais , Brassica/metabolismo
11.
Actas Dermosifiliogr ; 104(2): 156-8, 2013 Mar.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-22551703

RESUMO

Local anesthetics are widely used in clinical practice, and adverse effects are not uncommon. Delayed hypersensitivity reactions are among the most common effects, but immediate-type reactions may also occur. Patch testing should be considered in patients with hypersensitivity reactions. We present a case of allergic contact dermatitis to benzocaine that was detected incidentally by patch testing and highlight the importance of correctly interpreting patch test results when there are concomitant positive reactions.


Assuntos
Anestésicos Locais/efeitos adversos , Benzocaína/efeitos adversos , Dermatite Alérgica de Contato/diagnóstico , Dermatite Alérgica de Contato/etiologia , Testes do Emplastro , Feminino , Humanos , Pessoa de Meia-Idade
12.
J Environ Manage ; 105: 53-60, 2012 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-22525833

RESUMO

The degradation and detoxification towards the duckweed Lemna minor of 4-nitrophenol (4NP) was studied by means of bench-scale constructed wetlands (CWs), TiO(2)-photocatalysis and Fenton + photoFenton reactions. The main goal of this work was to compare the three treatment techniques to evaluate their possible combination for the efficient, low cost treatment of 4NP effluents. In CWs, adsorption on the substrate of 4NP was found to achieve 34-45%. Low concentrations (up to 100 ppm) of 4NP were successfully treated by CWs in 8-12 h. The microbial degradation of 4NP started after a lag phase which was longer with higher initial concentrations of the pollutant. The greatest degradation rate was found to occur at initial concentrations of 4NP between 60 and 90 ppm. Solar TiO(2)-photocatalysis was faster than the CWs. The greatest removals in terms of mass of 4NP removed after 6 h of irradiation were found to occur at 4NP concentrations of about 200 ppm. Fenton reaction provided complete 4NP degradation up to 500 ppm in only 30 min but TOC was removed by only about 40%. The resulting toxicities were below 20% for initial 4NP concentrations below 300 ppm. It was the Fenton + photoFenton combination (180 min in total) that provided TOC reductions up to 80% and negative L. minor growth inhibition for almost all the 4NP concentrations tested. The combination of solar TiO(2)-photocatalysis (6 h) with CWs (16 h) was able to completely treat and detoxify 4NP effluents with concentrations as high as 200 ppm of the organic.


Assuntos
Nitrofenóis/química , Nitrofenóis/toxicidade , Áreas Alagadas , Biodegradação Ambiental , Catálise , Luz , Nitrofenóis/metabolismo , Oxirredução , Plantas/metabolismo , Titânio , Microbiologia da Água
13.
Sci Total Environ ; 848: 157731, 2022 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-35917965

RESUMO

Hydrological and erosion dynamics are prone to change due to natural factors, human activities, or climate change. These changes are mainly related to modifications of land use and cover and can be assessed through the concept of connectivity, which analyzes how the spatial distribution of the elements facilitates runoff and sediment transport. The objective of this study was to evaluate changes in hydrological and sediment connectivity over 42 years and projected under a climate change scenario in the tropical Santa Cruz catchment in Aquismón, S.L.P., Mexico. The index of connectivity (IC) was computed using SedInConnect version 2.3 and the ArcSWAT model to estimate runoff. Hydrological connectivity and runoff were projected for 2027 using the MPI ECHAM 5 in the A2 climate change scenario. The results indicated that spatio-temporal changes in land use/cover, in conjunction with geomorphological features and expected climate change, would modify hydrological and sediment connectivity, especially in flat areas, where conversion of natural vegetation to cropland was steadily increasing over the years. Under future conditions, runoff and sediment transport are likely to increase, which will impact soil erosion and vulnerability to flooding but will not necessarily be negative. The study shows how spatial-temporal integration of runoff, sediments, landforms, land use cover and change, and connectivity can improve our understanding of catchment dynamics and the importance of analyses that characterize their evolution. The results can subsequently be applied and replicated in other catchments for management and restoration purposes.


Assuntos
Mudança Climática , Hidrologia , Inundações , Atividades Humanas , Humanos , México
14.
J Exp Biol ; 213(Pt 19): 3388-97, 2010 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-20833933

RESUMO

Ratios of compounds in host plant odors fluctuate with the phenological stage of the plant. In the present study, we investigated the effect of changing ratios of host plant volatile constituents on herbivore insect attraction and olfactory information processing. We tested a synthetic mixture of bioactive peach shoot volatiles with different concentrations of one of the mixture constituents, benzonitrile, on oriental fruit moth Cydia (=Grapholita) molesta females. Y-tube olfactometer bioassays showed that female attraction to the mixture was maintained while increasing the benzonitrile level up to 100 times. Further increases led to behaviorally ineffective mixtures. Then, we recorded odor-evoked neural activity patterns in the antennal lobes, the main olfactory center of the brain, using calcium imaging. Benzonitrile-containing mixtures elicited strong activation in two glomeruli, which were found to process mixture-related information in specific ways. Activation in one glomerulus directly paralleled behavioral effects of the different ratios tested whereas a deviating pattern was noted in the other glomerulus. Our results indicate that the ratio of constituents in a volatile mixture can be varied to a certain degree without reducing female attraction. Thus, volatile blends in nature might vary quantitatively within a certain range without affecting odor-guided host location. Neurophysiological results showed that the processing of mixture-related information inside the antennal lobes is not uniform across glomeruli. Thus, final processing of this information probably takes place in higher-order brain centers.


Assuntos
Mariposas/fisiologia , Plantas/química , Plantas/parasitologia , Animais , Antenas de Artrópodes/efeitos dos fármacos , Antenas de Artrópodes/inervação , Antenas de Artrópodes/fisiologia , Comportamento Animal/efeitos dos fármacos , Feminino , Interações Hospedeiro-Parasita/fisiologia , Mariposas/efeitos dos fármacos , Nitrilas/farmacologia , Odorantes , Feromônios/química , Feromônios/farmacologia , Prunus/química , Prunus/parasitologia , Compostos Orgânicos Voláteis/química , Compostos Orgânicos Voláteis/farmacologia , Volatilização
15.
Sci Total Environ ; 736: 139649, 2020 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-32474267

RESUMO

Connectivity is an emergent property that describes how complex topography favors or impedes sediment transfer processes. In active volcanic areas, high connectivity may lead to extremely efficient processes, such as lahars. The aim of the present study is to examine the behavior (activation-deactivation) of sub-basins affected by volcanic and anthropogenic processes by studying the changes in connectivity and hydrological efficiency. Two volcanic zones in Mexico were selected: Volcán de Colima and Popocatépetl volcano, the two most active and dangerous volcanoes in the country. The joint index of connectivity (ICJ) and lateral hydrological efficiency index (LHEI) were calculated for both volcanic areas in basins recently affected by eruptive activity (Volcán de Colima) and co-seismic landslides (Popocatépetl). The analyses enabled the identification of eleven recently activated sub-basins (3.82 km2) at the Volcán de Colima and fifteen (3.77 km2) at the Popocatepetl volcano, as a consequence of natural processes and economic activities. Critical thresholds indicating the percentage area of land cover/use at which a sub-basin reaches high or very high LHEI values and the percentage of land cover/use change required for a sub-basin to modify its behavior (activation-deactivation) were identified using classification trees. The holistic capacity of the concepts of connectivity and hydrological efficiency permits analyzing the spatiotemporal variations of sediment transport based on the interactions between the hydrogeomorphological dynamics of volcanic processes and the territorial impact of socio-economical activities. Through this approach, new active areas have been identified in both volcanoes; the knowledge of the processes that occurred in these areas represents a key factor for hazard and risk assessment for the population in the near future.

16.
Actas Urol Esp (Engl Ed) ; 44(3): 187-195, 2020 Apr.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-31843220

RESUMO

INTRODUCTION: Gleason score biopsy undergrading (GSBU) can have an impact on the management and prognosis of patients with prostate cancer. We analyze the possible impact of time and other clinical and analytical factors in the appearance of GSBU in our series. PATIENTS AND METHOD: Ambispective, multicenter study of 1955 patients with localized prostate cancer undergoing radical prostatectomy between 2005 and 2018. Descriptive statistics and hypothesis testing are reported by univariate and multivariate analyses. RESULTS: Mean age 63.69 (44-80) years, median PSA 8.70 ng / ml (1.23-99). GSBU was observed in 34.7% of the entire cohort. In 72.8% of the cases, the GSBU occurred in one consecutive Gleason score, with the progression from 3 + 3 to 3 + 4 being the most frequent (289 patients, 47.6%). Performing radical prostatectomy 90-180 days before or after the biopsy does not have an impact on its undergrading in any of the groups. In the univariate and multivariate analysis, the presence of tumor or pathological rectal examination in both lobes, the tumor load ≥50% of cylinders and a DPSA ≥0.20, showed independent discriminative capacity to select patients who presented GSBU. CONCLUSIONS: The time from biopsy to radical prostatectomy did not show impact on GSBU. The number of affected cylinders, bilateral tumor and DPSA are easily accessible parameters that can help us select patients with greater probability of presenting GSBU.


Assuntos
Próstata/patologia , Prostatectomia , Neoplasias da Próstata/patologia , Neoplasias da Próstata/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Biópsia , Humanos , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Estudos Prospectivos , Prostatectomia/métodos , Estudos Retrospectivos , Fatores de Tempo , Tempo para o Tratamento
17.
J Food Prot ; 72(8): 1735-8, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19722411

RESUMO

The antimicrobial activities of three chitosans with different molecular masses against six gram-negative and three gram-positive bacteria were examined. Campylobacter spp. were the microorganisms most sensitive to chitosan, regardless of their molecular mass. The MIC of chitosan for Campylobacter ranged from 0.005 to 0.05%, demonstrating the global sensitivity of campylobacters to chitosan. Chitosan caused a loss in the membrane integrity of Campylobacter, measured as an increase in cell fluorescence due to the uptake of propidium iodide, a dye that is normally excluded from cells with intact membranes. As cells entered the stationary phase, there was a change in cell membrane resistance toward a loss of integrity caused by chitosan. This study demonstrates that chitosans could be a promising antimicrobial to control Campylobacter.


Assuntos
Antibacterianos/farmacologia , Campylobacter/efeitos dos fármacos , Permeabilidade da Membrana Celular/efeitos dos fármacos , Quitosana/farmacologia , Campylobacter/crescimento & desenvolvimento , Contagem de Colônia Microbiana , Relação Dose-Resposta a Droga , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Negativas/crescimento & desenvolvimento , Bactérias Gram-Positivas/efeitos dos fármacos , Bactérias Gram-Positivas/crescimento & desenvolvimento , Testes de Sensibilidade Microbiana , Peso Molecular
18.
J Food Prot ; 72(1): 55-9, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19205464

RESUMO

The main objective of the present work was to study the influence of yeast-derived mannoproteins on the adherence to and invasion of Caco-2 cells by Campylobacter jejuni. Mannoprotein fractions were prepared by enzymatic and thermal extraction methods. The method used to prepare the mannoprotein extracts influenced their composition and determined the efficacy of the extract against C. jejuni adherence and/or invasion. The availability of mannose in the mannoprotein fraction seemed to be important for inhibiting effective adherence and invasion of Caco-2-cells by C. jejuni, although protein moieties also played a role in the process. The study of the mechanisms involved in the inhibition of C. jejuni adherence and invasion by mannoproteins may have further implications in the control of this foodborne pathogen.


Assuntos
Aderência Bacteriana/efeitos dos fármacos , Aderência Bacteriana/fisiologia , Células CACO-2/microbiologia , Campylobacter jejuni , Glicoproteínas de Membrana/farmacologia , Animais , Campylobacter jejuni/efeitos dos fármacos , Campylobacter jejuni/patogenicidade , Campylobacter jejuni/fisiologia , Qualidade de Produtos para o Consumidor , Microbiologia de Alimentos , Humanos , Virulência , Leveduras/química
19.
Food Chem Toxicol ; 46(9): 3003-14, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18602441

RESUMO

We tested the most widely held theory about the mode of action of petroleum spray oils (PSOs) on insects (i.e. anoxia). An nC24 petroleum oil was applied topically to cotton aphids (Aphis gossypii) and cluster caterpillars (Spodoptera litura), which then showed signs of mortality that are inconsistent with anoxia. The insects died soon after treatment, with most of the mortality occurring within the first 10min. Toxicity symptoms included loss of locomotory ability, unusual abdominal contractions associated with spiracular fluttering, and ultimately dehydration and necrosis within 24h. We therefore investigated the main mechanism(s) by which the nC24 petroleum oil interacts with the insects' cells and organs, and ultimately kills the insects. The results suggest a mode of action that relates to the liphophylic properties of the oil. This includes rapid penetration through the insect cuticle followed by accumulation in the lipid-containing tissues, mainly those of the CNS, and finally penetration into the nerve cells themselves. In vitro tests with isolated insect cells further revealed that the oil penetrates the cytoplasm and induces 100% mortality of these cells within 2min of application. No signs of oil accumulation within the tracheae were observed, so it is unlikely that anoxia is taking place at any stage of the intoxication process. Electrophysiological studies confirm that oil accumulation in the nerve ganglia has the direct effect of suppressing synaptic transmission in insect ganglia as well as in the neuromuscular junctions of vertebrates (toads and rats). These results demonstrate conclusively that at least some modern PSOs do not kill insects by anoxia, but by a range of cellular disruptions that lead to rapid insect death. The implications of our findings for the development of oil-based integrated pest management strategies are discussed.


Assuntos
Afídeos/fisiologia , Controle de Insetos/métodos , Petróleo/toxicidade , Spodoptera/fisiologia , Animais , Bufo marinus , Permeabilidade da Membrana Celular/efeitos dos fármacos , Drosophila melanogaster , Gânglios dos Invertebrados/efeitos dos fármacos , Larva/efeitos dos fármacos , Microscopia Confocal , Sistema Nervoso/efeitos dos fármacos , Ratos , Ratos Wistar
20.
J Food Prot ; 71(7): 1496-9, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18680954

RESUMO

A wine model was evaluated to determine the influence of aging on the ability of whole yeast cells (WY) and yeast cell walls (YCW) to remove ochratoxin A (OTA). Aging and autolysis were monitored for 214 h in the model wine. The original concentration of OTA in the model wine was 10 microg/liter, and WY and YCW were added at a final concentration of 1 g/liter. YCW mannoproteins were involved in the removal of OTA from the model wine through adsorption mechanisms. Aging affected the capacity of WY to remove OTA, but YCW removal capacity remained constant during aging. A previous heat treatment (85 degrees C for 10 min) of WY and YCW increased their removal capacity and increased the efficiency of the decontamination process.


Assuntos
Descontaminação/métodos , Contaminação de Alimentos/análise , Ocratoxinas/análise , Saccharomyces cerevisiae/fisiologia , Vinho/análise , Adsorção , Autólise , Temperatura Alta , Humanos , Microbiologia Industrial , Fatores de Tempo , Vitis/química , Vitis/microbiologia , Vinho/microbiologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA