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AIMS: This study aimed to gather information on farming practices employed in organic lettuce fields in Sao Paulo, Brazil and associate these practices with the microbiological characteristics of the products. METHODS AND RESULTS: Practices were surveyed using a questionnaire applied in ten farms, where 200 heads of lettuce were collected and submitted to enumeration of total coliforms and generic Escherichia coli and tested for Salmonella spp. using culture and molecular (qPCR) methods. Based on the responses, the farms could be clustered in two groups: group 1, comprised by six farms, where chicken manure was used as fertilizer in most of them and the composting process was not performed on site; and group 2, comprised by four farms, where other types of fertilizer were used, and the composting process was performed on site. Generic E. coli was detected in 56 (28%) samples, with an average of 1·1 ± 0·7 log MPN per g. Salmonella DNA was detected in two (1%) samples by qPCR. CONCLUSIONS: The prevalence and bacterial loads of generic E. coli, and the occurrence of Salmonella, even at low populations undetectable by conventional culture methods, highlight the need for control measures during farming practices to reduce microbial contamination and risks of foodborne illnesses. These measures include the use of properly composted manure and appropriate washing procedures for leafy vegetables before consumption. SIGNIFICANCE AND IMPACT OF THE STUDY: The obtained data contribute to a better understanding of the farming practices of organically grown lettuces in Sao Paulo, Brazil.
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Escherichia coli/isolamento & purificação , Microbiologia de Alimentos , Lactuca/microbiologia , Agricultura Orgânica/estatística & dados numéricos , Salmonella/isolamento & purificação , Brasil , Escherichia coli/genética , Escherichia coli/crescimento & desenvolvimento , Fazendas , Humanos , Agricultura Orgânica/normas , Salmonella/genética , Salmonella/crescimento & desenvolvimentoRESUMO
Migraine as primary headache is a life-long disease which is relevant for the quality of life and is based on complex genetics. It often starts in childhood with symptoms typical for the specific age. These show different nuances compared to the migraine symptoms in adults, for example, regarding (bilateral/unilateral) localization of the acute migraine headache. Only over the course of years-during adolescence and young adulthood-do the more specific symptoms as defined by the International Classification of Headache Disorders (ICHD 3 beta) develop. In this article we focus on the clinical specifics of children and adolescents with migraine. We elaborately refer to the trigeminocervical complex (TCC) because it forms a conceptual bridge for the understanding of migraine, for psychoeducation, and for therapeutic options. We pragmatically discuss options and limits of treatments.
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Transtornos de Enxaqueca/diagnóstico , Transtornos de Enxaqueca/fisiopatologia , Músculos do Pescoço/fisiopatologia , Analgésicos/uso terapêutico , Terapia Combinada , Traumatismos Craniocerebrais/complicações , Traumatismos Craniocerebrais/fisiopatologia , Diagnóstico Diferencial , Humanos , Transtornos de Enxaqueca/genética , Transtornos de Enxaqueca/terapia , Fatores de Risco , Estimulação Magnética Transcraniana , Nervo Trigêmeo/fisiopatologiaRESUMO
BACKGROUND AND PURPOSE: Headache is a common health problem in adolescents. There are a number of risk factors for headache in adolescents that are amenable to intervention. The aim of the study was to assess the effectiveness of a low-level headache prevention programme in the classroom setting to prevent these risk factors. METHODS: In all, 1674 students in 8th-10th grade at 12 grammar schools in greater Munich, Germany, were cluster randomized into intervention and control groups. A standardized 60-min prevention lesson focusing on preventable risk factors for headache (physical inactivity, coffee consumption, alcohol consumption and smoking) and providing instructions on stress management and neck and shoulder muscle relaxation exercises was given in a classroom setting. Seven months later, students were reassessed. The main outcome parameter was headache cessation. Logistic regression models with random effects for cluster and adjustment for baseline risk factors were calculated. RESULTS: Nine hundred students (intervention group N = 450, control group N = 450) with headache at baseline and complete data for headache and confounders were included in the analysis. Headache cessation was observed in 9.78% of the control group compared with 16.22% in the intervention group (number needed to treat = 16). Accounting for cluster effects and confounders, the probability of headache cessation in the intervention group was 1.77 (95% confidence interval = [1.08; 2.90]) higher than in the control group. The effect was most pronounced in adolescents with tension-type headache: odds ratio = 2.11 (95% confidence interval = [1.15; 3.80]). CONCLUSION: Our study demonstrates the effectiveness of a one-time, classroom-based headache prevention programme.
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Cefaleia/terapia , Educação em Saúde/métodos , Adolescente , Feminino , Alemanha , Cefaleia/prevenção & controle , Humanos , Masculino , Resultado do TratamentoRESUMO
OBJECTIVE: Animal experiments and studies in adults have shown that the neurotransmitter serotonin (5-HT) plays an important role in learning and memory processes. However, data on this relationship in young persons are scarce, and neurodietary research in this age group is limited compared with the extensive literature on adults. Here, we aimed to explore the effects of a diminished central nervous 5-HT synthesis, which is achieved by acute tryptophan depletion (ATD) Moja-De , on memory function in young males with attention deficit hyperactivity disorder (ADHD). METHOD: Twenty-two male patients with ADHD (ages 9-15 years, mean 10.95 ± 1.17 years) received ATD, thus diminishing central nervous 5-HT synthesis, and a tryptophan-balanced amino acid load (BAL) in a randomized, double-blind, within-subject, crossover design study. Approximately 1.7 h after administration of ATD/BAL, verbal declarative memory was assessed using the 'Auditory Verbal-Learning-Test' (AVLT). RESULTS: There were no significant effects of ATD administration on verbal declarative memory function. CONCLUSION: In this study, changes in 5-HT neurotransmission were not associated with specific aspects of verbal declarative memory in young persons with ADHD. Future studies with healthy control groups that address effects of covarying attentional processes are warranted.
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Transtorno do Deficit de Atenção com Hiperatividade , Dietoterapia/métodos , Rememoração Mental/efeitos dos fármacos , Serotonina/biossíntese , Triptofano , Comportamento Verbal/efeitos dos fármacos , Adolescente , Transtorno do Deficit de Atenção com Hiperatividade/diagnóstico , Transtorno do Deficit de Atenção com Hiperatividade/metabolismo , Transtorno do Deficit de Atenção com Hiperatividade/psicologia , Transtorno do Deficit de Atenção com Hiperatividade/terapia , Sistema Nervoso Central/metabolismo , Criança , Estudos Cross-Over , Método Duplo-Cego , Humanos , Masculino , Técnicas Psicológicas , Psicotrópicos/metabolismo , Psicotrópicos/farmacologia , Tempo de Reação/efeitos dos fármacos , Fatores Sexuais , Transmissão Sináptica/efeitos dos fármacos , Transmissão Sináptica/fisiologia , Resultado do Tratamento , Triptofano/metabolismo , Triptofano/farmacologiaRESUMO
Primary immune thrombocytopenia (ITP) in children is usually self-limiting and harmless but can, rarely, result in life-threatening complications. The case of an 11-year-old girl with ITP is presented who developed recurrent intracranial hemorrhages followed by cerebral infarctions. The clinical course was complicated by a graft-versus-host disease involving several organs. Treatment was performed according to the current international consensus report of 2010 with glucocorticoids, immunoglobulin G, anti-D-immunoglobulin and additionally embolisation of the splenic artery. The girl survived. Reliable predictors, preventive measures for life-threatening complications in ITP and more information about the effectiveness and side-effects of the recommended treatment are urgently needed.
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Doença Enxerto-Hospedeiro/complicações , Hemorragias Intracranianas/complicações , Púrpura Trombocitopênica Idiopática/complicações , Infarto Cerebral/complicações , Infarto Cerebral/terapia , Criança , Terapia Combinada , Craniotomia , Embolização Terapêutica , Feminino , Glucocorticoides/uso terapêutico , Doença Enxerto-Hospedeiro/terapia , Humanos , Imunoglobulina G/uso terapêutico , Infusões Intravenosas , Hemorragias Intracranianas/terapia , Metilprednisolona/uso terapêutico , Transfusão de Plaquetas/efeitos adversos , Púrpura Trombocitopênica Idiopática/terapia , Recidiva , Imunoglobulina rho(D)/uso terapêutico , Baço/irrigação sanguínea , Tomografia Computadorizada por Raios XRESUMO
OBJECTIVE: The number of studies investigating and understanding the disease mechanisms of Duchenne muscular dystrophy (DMD) in human clinical trials have increased substantially over the last decade. Suitable clinical instruments for the measurement of disease progress and drug efficiency are mandatory, but currently not available, especially in the youngest patients. The aim of this study was to detect a reproducible pattern of muscle involvement in early stages potentially preceding evidence of motor regression. MATERIAL AND METHODS: A cohort of 25 DMD patients aged 1-6 years at the first presentation were examined at multiple timepoints and compared with age-matched healthy controls. Muscle ultrasound was quantified using computer-analyzed gray scale levels (GSL) and blinded visual rating, using a modified Heckmatt scale. RESULTS: Changes in muscle echogenicity in DMD patients occurred very early, clearly preceding motor regression and in some cases, even before the motor plateau phase was reached. Visual rating and GSL identified the earliest changes in the proximal adductor magnus muscle. CONCLUSION: Muscle ultrasound can be used as an additional method to assess the disease progression and for decision-making in paucisymptomatic DMD patients. Sonographic changes in the ad-ductor magnus muscle seem to be the first detectable changes with a recognisable pattern.
Assuntos
Músculo Esquelético/diagnóstico por imagem , Músculo Esquelético/patologia , Distrofia Muscular de Duchenne/diagnóstico por imagem , Distrofia Muscular de Duchenne/patologia , Criança , Pré-Escolar , Progressão da Doença , Humanos , Lactente , Masculino , Ultrassonografia/métodosRESUMO
Interstellar dust grains intercepted by the dust detectors on the Ulysses and Galileo spacecrafts at heliocentric distances from 2 to 4 astronomical units show a deficit of grains with masses from 1 x 10(-17) to 3 x 10(-16) kilograms relative to grains intercepted outside 4 astronomical units. To divert grains out of the 2- to 4-astronomical unit region, the solar radiation pressure must be 1.4 to 1.8 times the force of solar gravity. These figures are consistent with the optical properties of spherical or elongated grains that consist of astronomical silicates or organic refractory material. Pure graphite grains with diameters of 0.2 to 0.4 micrometer experience a solar radiation pressure force as much as twice the force of solar gravity.
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Poeira Cósmica , Gravitação , Magnetismo , Sistema SolarRESUMO
We describe the extent to which presynaptic structures at the embryonic neuromuscular junction of Drosophila can form in mutants where development of postsynaptic somatic muscles is affected. Although twist mutant embryos lack mesoderm, motor axons still grow out of the CNS and form morphologically normal presynaptic active zones, independent of their target cells. In myoblast city mutant embryos, myoblasts do not fuse but form fully differentiated mononucleate muscles, which make functional neuromuscular synapses with correctly localized presynaptic active zones. Myoblasts also fail to fuse but still attract appropriate innervation in mef2 mutant embryos. However, these myoblasts fail to differentiate into muscles and presynaptic active zones fail to localize at neuromuscular contacts. Thus, the process of synapse formation can be genetically separated from the process of target recognition, revealing that localization of presynaptic active zones requires mef2-dependent muscle differentiation.
Assuntos
Axônios/fisiologia , Drosophila/embriologia , Junção Neuromuscular/fisiologia , Sinapses/fisiologia , Animais , Axônios/ultraestrutura , Diferenciação Celular , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/fisiologia , Drosophila/genética , Proteínas de Drosophila , Embrião não Mamífero , Genes de Insetos , Fatores de Transcrição MEF2 , Potenciais da Membrana , Mesoderma , Neurônios Motores/fisiologia , Neurônios Motores/ultraestrutura , Músculos/citologia , Músculos/embriologia , Músculos/inervação , Fatores de Regulação Miogênica , Fibras Nervosas/fisiologia , Fibras Nervosas/ultraestrutura , Junção Neuromuscular/ultraestrutura , Mutação Puntual , Deleção de Sequência , Sinapses/ultraestrutura , Fatores de Transcrição/genética , Fatores de Transcrição/fisiologiaRESUMO
Axon pathfinding and target choice are governed by cell type-specific responses to external cues. Here, we show that in the Drosophila embryo, motorneurons with targets in the dorsal muscle field express the homeobox gene even-skipped and that this expression is necessary and sufficient to direct motor axons into the dorsal muscle field. Previously, it was shown that motorneurons projecting to ventral targets express the LIM homeobox gene islet, which is sufficient to direct axons to the ventral muscle field. Thus, even-skipped complements the function of islet, and together these two genes constitute a bimodal switch regulating axonal growth and directing motor axons to ventral or to dorsal regions of the muscle field.
Assuntos
Axônios/fisiologia , Proteínas de Bactérias , Proteínas de Drosophila , Drosophila/embriologia , Proteínas de Homeodomínio/fisiologia , Neurônios Motores/fisiologia , Fatores de Transcrição , Animais , Adesão Celular/fisiologia , Embrião não Mamífero/fisiologia , Expressão Gênica/fisiologia , Proteínas de Homeodomínio/antagonistas & inibidores , Proteínas de Homeodomínio/genética , Músculos/inervação , Vias Neurais/embriologia , Junção Neuromuscular/embriologia , Transmissão Sináptica/fisiologiaRESUMO
Listeria monocytogenes is a cause of concern to food industries, mainly for those producing ready-to-eat (RTE) products. This microorganism can survive processing steps such as curing and cold smoking and is capable of growing under refrigeration temperatures. Its presence in RTE fish products with extended shelf life may be a risk to the susceptible population. One example of such a product is gravlax salmon; a refrigerated fish product not exposed to listericidal processes and was the subject of this study. In order to evaluate the incidence and dissemination of L. monocytogenes 415 samples were collected at different steps of a gravlax salmon processing line in São Paulo state, Brazil. L. monocytogenes was confirmed in salmon samples (41%), food contact surfaces (32%), non-food contact surfaces (43%) and of food handlers' samples (34%), but could not be detected in any ingredient. 179 L. monocytogenes isolates randomly selected were serogrouped and typed by PFGE. Most of L. monocytogenes strains belonged to serogroup 1 (73%). 61 combined pulsotypes were found and a dendrogram identified six clusters: most of the strains (120) belonged to cluster A. It was suggested that strains arriving into the plant via raw material could establish themselves in the processing environment contaminating the final product. The wide dissemination of L. monocytogenes in this plant indicates that a great effort has to be taken to eliminate the microorganism from these premises, even though it was not observed multiplication of the microorganism in the final product stored at 4°C up to 90 days.
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BACKGROUND: The objective was to evaluate a supposed clinical interdependency of myofascial trigger points and migraine in children. Such interdependency would support an interaction of spinal and trigeminal afferences in the trigemino-cervical complex as a contributing factor in migraine. METHODS: Children ≤18 years with the confirmed diagnosis of migraine were prospectively investigated. Comprehensive data on medical history, clinical neurological and psychological status were gathered. Trigger points in the trapezius muscle were identified by palpation and the threshold of pressure pain at these points was measured. Manual pressure was applied to the trigger points, and the occurrence and duration of induced headache were recorded. At a second consultation (4 weeks after the first), manual pressure with the detected pressure threshold was applied to non-trigger points within the same trapezius muscle (control). Headache and related parameters were again recorded and compared to the results of the first consultation. RESULTS: A total of 13 girls and 13 boys with migraine and a median age of 14.5 (Range 6.3-17.8) years took part in the study. Manual pressure to trigger points in the trapezius muscle led to lasting headache after termination of the manual pressure in 13 patients while no patient experienced headache when manual pressure was applied to non-trigger points at the control visit (p < 0.001). Headache was induced significantly more often in children ≥12 years and those with internalizing behavioural disorder. CONCLUSION: We found an association between trapezius muscle myofascial trigger points and migraine, which might underline the concept of the trigemino-cervical complex, especially in adolescents. SIGNIFICANCE: In children with migraine headache can often be induced by pressure to myofascial trigger points, but not by pressure to non-trigger points in the trapezius muscle. This supports the hypothesis of a trigemino-cervical-complex in the pathophysiology of migraine, which might have implications for innovative therapies in children with migraine.
Assuntos
Transtornos de Enxaqueca/fisiopatologia , Síndromes da Dor Miofascial/fisiopatologia , Músculos Superficiais do Dorso/fisiopatologia , Pontos-Gatilho/fisiopatologia , Adolescente , Criança , Feminino , Humanos , Masculino , Estudos ProspectivosRESUMO
During Drosophila embryogenesis, motor axons leave the central nervous system (CNS) as two separate bundles, the segmental nerve (SN) and intersegmental nerve (ISN). From these, axons separate (defasciculate) progressively in a characteristic pattern, initially as nerve branches and then as individual axons, to innervate target muscles [1] [2]. This pattern of branching resembles the outgrowth and defasciculation of motor axons from the neural tube of vertebrate embryos. The factors that trigger nerve branching are unknown. In vertebrate limbs, the branched innervation may depend on mesodermal cues, in particular on the connective tissues that organise the muscle pattern [3]. In Drosophila, the muscle pattern is organised by specific mesodermal cells, the founder myoblasts, which initiate the development of individual muscles [4][5][6]. Founder myoblasts fuse with neighbouring non-founder myoblasts and entrain these to a specific muscle programme, which also determines their innervation [4] [7]. In the absence of mesoderm, ISN and SN can form, but motor axons fail to defasciculate from these bundles [7]. The cue(s) for nerve branching therefore lie within the mesoderm, most likely in the muscles and/or in the precursor cells of the adult musculature [8]. Here, we show that founder myoblasts are the source of the cue(s) that are required to trigger defasciculation and targeted growth of motor axons. Moreover, we found that a single founder myoblast can trigger the defasciculation of an entire nerve branch. This suggests that the muscle field is structured into sets of muscles, each expressing a common defasciculation cue for a particular nerve branch.
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Axônios/fisiologia , Proteínas de Drosophila , Drosophila/embriologia , Neurônios Motores/fisiologia , Músculos/fisiologia , Animais , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Fatores de Transcrição MEF2 , Músculos/citologia , Fatores de Regulação Miogênica , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismoRESUMO
BACKGROUND: The present study investigated the effects of rapid tryptophan depletion (RTD), and the ensuing reduction of central nervous system levels of serotonin (5-HT), upon reactive aggression in patients with attention deficit/hyperactivity disorder (ADHD). Furthermore, it was asked whether the relation between 5-HT function and behavioural aggression in patients is influenced by their age, the intensity of their attention problems or their comorbid symptoms. METHODS: The study employed a double-blind, within-subject crossover design. On day 1, 22 male adolescent patients with ADHD were subjected to RTD and the subsequent reduction of central 5-HT levels. On day 2, they received a tryptophan-balanced amino acid mixture (BAL), which acted as a placebo. On both days, 4.5 h after the intake of the RTD/BAL amino acids, reactive aggressive behaviour was provoked using a competitive reaction time game, which consisted of both high and low provocation conditions. RESULTS: The number of aggressive responses was significantly higher after low provocation during acute tryptophan depletion, in comparison to the placebo. Furthermore, this study provides evidence that neither age nor the intensity of attention symptoms in ADHD patients had an impact on the relation between 5-HT and reactive aggression. CONCLUSION: This study indicates that in children with ADHD, there is an inverse relationship between 5-HT and aggression.
Assuntos
Agressão/psicologia , Transtorno do Deficit de Atenção com Hiperatividade/fisiopatologia , Transtorno do Deficit de Atenção com Hiperatividade/psicologia , Triptofano/sangue , Adolescente , Transtorno do Deficit de Atenção com Hiperatividade/sangue , Estudos Cross-Over , Método Duplo-Cego , Alimentos Formulados/efeitos adversos , Humanos , Masculino , Análise Multivariada , PsicometriaRESUMO
A new instrument to analyze the chemical composition of dust particles in situ in space has been developed. The large target area ( approximately 0.2 m(2)) makes this instrument well suited for detecting a statistically significant number of interstellar dust grains or other dust particles with a low flux. The device is a reflectron-type time-of-flight mass spectrometer that uses only flat electrodes for the generation of the parabolic potential. The instrument analyzes the ions from the impact generated plasma due to hypervelocity dust impacts onto a solid target surface. The SIMION ion optics software package is used to investigate different potential field configurations and optimize the mass resolution and focusing of the ions. The cylindrically symmetric instrument operates with six ring electrodes and six annular electrodes biased to different potentials to create the potential distribution of the reflectron. The laboratory model of the instrument has been fabricated and tested. Hypervelocity dust impacts are simulated by laser ablation using a frequency doubled Nd:YAG laser with approximately 8 ns pulse length. The experimental data show typical mass resolution m/Deltam approximately 200.
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Poeira Cósmica/análise , Lasers , Espectrometria de Massas , Software , Eletrodos , Espectrometria de Massas/instrumentação , Espectrometria de Massas/métodos , Tamanho da Partícula , Sensibilidade e EspecificidadeRESUMO
BACKGROUND/PURPOSE: Migraine is frequent in young adults and adolescents and often associated with neck muscle tension and pain. Common pathophysiological pathways, such as reciprocal cervico-trigeminal activation, are assumed. Tense areas within the neck muscles can be clinically observed many patients with migraine. The aim of this pilot case study was to visualize these tense areas via magnet resonance imaging (MRI). METHODS: Three young patients with migraine were examined by an experienced investigator. In all three patients tense areas in the trapezius muscles were palpated. These areas were marked by nitroglycerin capsules on the adjacent skin surface. RESULTS: The MRI showed focal signal alterations at the marked locations within the trapezius muscles. CONCLUSION: Visualization of palpable tense areas by MRI may be usefully applied in the future to help elucidate the underlying pathophysiological processes of migraine.
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Transtornos de Enxaqueca/fisiopatologia , Músculos Superficiais do Dorso/fisiopatologia , Adolescente , Adulto , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Transtornos de Enxaqueca/etiologia , Projetos Piloto , Espasmo/complicações , Adulto JovemRESUMO
This study examined the occurrence of Y. enterocolitica and other Yersinia species in Brazilian food products. Samples included raw vegetables (lettuce, spinach, watercress and chicory), raw and pasteurized milk as well as meat and meat products. Raw milk samples were obtained in a dairy plant and the other food samples were purchased at the retail level in Sao Paulo city. Yersinia spp. was isolated from raw milk (45.2%), pasteurized milk (14.3%), raw vegetables samples (13.3%) and meat and meat products (40.0%). Most of the strains isolated were Y. enterocolitica followed by Y. intermedia. This high incidence in raw milk and meat and meat products implies that these products are a likely sources of contamination with Yersinia spp.
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Microbiologia de Alimentos , Yersinia/isolamento & purificação , Animais , Tipagem de Bacteriófagos , Brasil , Carne/microbiologia , Produtos da Carne/microbiologia , Leite/microbiologia , Sorotipagem , Esterilização , Verduras/microbiologia , Yersinia/classificação , Yersinia enterocolitica/classificação , Yersinia enterocolitica/isolamento & purificaçãoRESUMO
The detection and identification of Salmonella spp. is still troublesome and time consuming to the food industry. Employing the modified semi-solid Rappaport-Vassiliadis medium (MSRV), presumptive results for Salmonella can be obtained in 48 h, representing an interesting alternative to the standard methods. The specificity and sensitivity of the MSRV method were evaluated in this research. The efficiency of this method was also compared with the methodology recommended by the US Food and Drug Administration (FDA) using bismuth sulfite agar, XLT4 agar and Rambach agar. A total of 146 food samples comprised of 41 chicken thighs, 35 Brazilian fresh pork sausages, 35 samples of cocoa powder and/or granulated cocoa and 35 samples of grated fresh coconut, were examined. Overall, the rapid method (direct + indirect) and the standard culture detected 96.1% and 84.6% of the positive samples, respectively. No Salmonella was detected in the coconut or cocoa samples by any of the methods. Eighteen (43.9%) chicken thigh samples were contaminated with the microorganism. The rapid method (direct + indirect) and the standard culture detected 94.4% and 88.9% of these, respectively. Salmonella was detected in eight (22.8%) fresh pork sausage samples. The MSRV method detected Salmonella in all eight samples, while the standard gave positive results in six (75%). When compared with the standard method, the indirect method showed 86.4% sensitivity and 96.8% specificity, while the direct MSRV showed a sensitivity of 71.4% and specificity of 99.2%. Combined, both MSRV methods showed 95.5% sensitivity and 96.8% specificity. The MSRV medium also reduces the time necessary for the isolation of Salmonella from foods.
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Microbiologia de Alimentos , Salmonella/isolamento & purificação , Animais , Cacau/microbiologia , Galinhas , Cocos/microbiologia , Meios de Cultura , Carne/microbiologia , Sensibilidade e Especificidade , Suínos , Fatores de TempoRESUMO
The incidence of Salmonella spp., Listeria spp. and Listeria monocytogenes in horsemeat for human consumption was investigated. One-hundred and twenty-one samples of frozen horsemeat collected from two Brazilian abattoirs were analysed over a period of 1 year. Twenty-two samples (18.2%) were positive for Listeria spp. with nine (7.4%) containing L. monocytogenes. None of the samples harbored Salmonella spp.
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Microbiologia de Alimentos , Listeria monocytogenes/isolamento & purificação , Listeria/isolamento & purificação , Carne/microbiologia , Salmonella/isolamento & purificação , Animais , Contagem de Colônia Microbiana , Cavalos , Humanos , IncidênciaRESUMO
PURPOSE: Retinal dystrophic (rd) mice lose most of their rod photoreceptors within the first three weeks after birth. We determined the age-related distribution of peanut agglutinin lectin (PNA)-labeled cones during the first 12 months of age. We also investigated whether the density of ON-bipolar cells expressing L7 protein was affected by their loss of photoreceptor inputs. METHODS: rd mice were selected from a transgenic strain which expresses an L7-beta-galactosidase fusion gene localized to ON-bipolar cells. Cones were stained with PNA and ON-bipolar cells with bluo-gal (halogenated indolyl-beta-D-galactoside). Retinas were flat-mounted and observed at 1, 2, 3, 6 and 12 months of age. RESULTS: PNA-labeled cones are distributed unevenly across the retina at 1 month postnatal. Their concentration decreases first in the central and far peripheral retina, leaving a ring of labeled cells in the midperipheral region. At 3 months, a larger patch of cones remains in the supero-temporal midperipheral region and a smaller patch in the infero-nasal retina. By 6 months, few cones remain in the infero-nasal retina; by 1 year approximately 100 cones remain in the entire retina, localized to the superior midperipheral region. ON-bipolar cells appear evenly distributed at 1 month. By 2-3 months, relatively more bluo-gal staining is seen in the midperipheral regions underlying dense cone populations. At 6-12 months, bluo-gal label is distributed in a spotty pattern with little or no staining seen in areas of apparent neovascularization. CONCLUSIONS: (1) PNA-labeling of cones in the rd retina deteriorates in a distinct spatial pattern with the longest cone survival in the midperipheral superior retina. (2) ON-bipolar cells are more densely labeled in regions of high cone density during the early months of cone degeneration and, in later stages, show relative decreases in regions of apparent neovascularization.