Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 26
Filtrar
1.
Mol Psychiatry ; 22(7): 1035-1043, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-27725661

RESUMO

Developmental risk factors, such as the exposure to stress or high levels of glucocorticoids (GCs), may contribute to the pathogenesis of anxiety disorders. The immunomodulatory role of GCs and the immunological fingerprint found in animals prenatally exposed to GCs point towards an interplay between the immune and the nervous systems in the etiology of these disorders. Microglia are immune cells of the brain, responsive to GCs and morphologically altered in stress-related disorders. These cells are regulated by adenosine A2A receptors, which are also involved in the pathophysiology of anxiety. We now compare animal behavior and microglia morphology in males and females prenatally exposed to the GC dexamethasone. We report that prenatal exposure to dexamethasone is associated with a gender-specific remodeling of microglial cell processes in the prefrontal cortex: males show a hyper-ramification and increased length whereas females exhibit a decrease in the number and in the length of microglia processes. Microglial cells re-organization responded in a gender-specific manner to the chronic treatment with a selective adenosine A2A receptor antagonist, which was able to ameliorate microglial processes alterations and anxiety behavior in males, but not in females.


Assuntos
Ansiedade/metabolismo , Receptor A2A de Adenosina/fisiologia , Animais , Transtornos de Ansiedade/patologia , Células Cultivadas , Dexametasona/farmacologia , Feminino , Glucocorticoides/metabolismo , Glucocorticoides/farmacologia , Lipopolissacarídeos/farmacologia , Masculino , Microglia/efeitos dos fármacos , Microglia/fisiologia , Gravidez , Efeitos Tardios da Exposição Pré-Natal , Ratos , Ratos Wistar , Sexismo
2.
Int J Sports Med ; 37(8): 653-8, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27176885

RESUMO

The objective of this investigation was to evaluate the accuracy of peak vertical jump power (VJP) to identify children with bone mineral density (BMD) below average, defined as BMD measured by DXA and adjusted for body height at the whole body less head≤- 1.0 standard deviation (SD). The sample included 114 boys and girls aged 8.5±0.4 years old. VJP was estimated from a countermovement jump performed on a contact mat using the measured flight time to calculate the height of rise of the center of gravity. Logistic regression analysis revealed that the odds ratio of having BMD≤1.0 SD decreased 1.2% per watt of power and the probability of BMD below average was 75.6% higher in boys than in girls with the same peak power jump. Receiver operating characteristic analysis showed that the best trade-off between sensitivity and specificity to identify children with BMD<- 1.0 SD was 635 watts in boys (sensitivity=63.3%; specificity=69.2%; AUC=0.816, 95% CI: 0.681-0.95; p<0.001) and 515 watts in girls (sensitivity=75.0%; specificity=77.0%; AUC=0.849, 95% CI: 0.698-0.999; p=0.002). These cut-off values correspond to a vertical jump of 19.9 cm and 20.5 cm in 8-year-old boys and girls, respectively. The VJP showed a reasonable sensitivity and specificity as well good discriminant ability to identify children with BMD below average.


Assuntos
Densidade Óssea , Osso e Ossos/fisiologia , Composição Corporal , Estatura , Criança , Teste de Esforço , Feminino , Humanos , Modelos Logísticos , Masculino , Curva ROC , Sensibilidade e Especificidade
3.
Osteoporos Int ; 25(8): 2035-45, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24809809

RESUMO

UNLABELLED: Physical activity (PA) have long been identified as a determining factor of the mineralization of the skeleton, particularly in children. Our research supports the hypothesis that the geometry of the pelvis and proximal femur (PF) might moderate the effect of PA in the relative mineralization of the PF subregions. INTRODUCTION: Using a longitudinal observational study with two evaluations and a 1-year follow-up interval, we investigated the influence of PA and skeletal geometry in bone mineral density (BMD) and bone mass distribution at the PF in 96 girls and 81 boys (10-12 years). It is plausible that the geometry of the pelvis-PF structure moderates mechanical forces exerted at the hip and therefore creates different degrees of mineralization among PF subregions. METHODS: Whole body and left hip dual X-ray absorptiometry scans were used to derive geometric measures of the pelvis-inter-acetabular distance (IAD) and PF abductor lever arm (ALA). BMD was measured at the integral, superolateral (SL), and inferomedial (IM) femoral neck (FN), and at the trochanter (TR). These subregions were used to represent bone mass distribution via three BMD ratios: FN/PF, IM/SL, and TR/PF. PA was measured using accelerometry and a bone-specific PA questionnaire (BPAQ). RESULTS: A longitudinal data approach revealed BPAQ as a positive predictor for all BMD variables (p < 0.05) except TR BMD in girls and FN BMD in boys. Comparing the most active with the less-active participants, the greatest benefits of PA were observed at the FN of the girls with the lowest IAD (p < 0.001), at the FN of the boys with the highest IAD (p < 0.001) and at the TR of the boys with the lowest ALA (p < 0.01). CONCLUSIONS: Geometric measures of IAD and ALA seem to moderate the effect of PA role in the relative mineralization of the PF regions. On the other hand, absolute BMD levels appear to be determined by mechanical loading.


Assuntos
Densidade Óssea/fisiologia , Fêmur/fisiologia , Atividade Motora/fisiologia , Absorciometria de Fóton/métodos , Composição Corporal/fisiologia , Criança , Feminino , Fêmur/anatomia & histologia , Fêmur/diagnóstico por imagem , Colo do Fêmur/anatomia & histologia , Colo do Fêmur/diagnóstico por imagem , Colo do Fêmur/fisiologia , Articulação do Quadril/anatomia & histologia , Articulação do Quadril/diagnóstico por imagem , Humanos , Estudos Longitudinais , Masculino , Caracteres Sexuais
4.
J Sports Med Phys Fitness ; 52(2): 190-7, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22525656

RESUMO

AIM: This study investigated the variation with age of different attributes that support the physical functioning in community-dwelling older adults having as reference scores from young adults. METHODS: The study was a cross-sectional study. Participants were 559 older adults and 79 young adults grouped according to gender and age (Y:20-29, A:60-64, B:65-69, C:70-74, D:75-79 and E:≥ 80 years). Strength, flexibility, agility, aerobic endurance, and balance were evaluated by Fullerton tests. RESULTS: ANOVA and Bonferroni post-hoc tests showed that compared to young, the 60-64 years group showed decreased values in almost all attributes of physical function. In older adults, additional differences were observed in females mainly between the 60-64 years group and the 70-74 years, 75-79 years, and:≥ 80 years groups, and in males between the 60-64 years group and the ≥ 80 years group (P<0.05). Comparisons between standardized physical function attributes (T-scores) done by repeated measures and contrasts demonstrated that, across age groups, agility and dynamic balance showed the highest rate loss in both genders, and lower body flexibility showed the lowest (P<0.01). CONCLUSION: Physical function reduction seems to occur earlier in women than in men and abilities involving multiple structures such as balance, agility, and aerobic endurance showed the most loss.


Assuntos
Envelhecimento/fisiologia , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Destreza Motora , Força Muscular , Resistência Física , Equilíbrio Postural , Amplitude de Movimento Articular , Fatores Sexuais , Adulto Jovem
5.
Epidemiol Infect ; 139(5): 754-64, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-20653990

RESUMO

Targets for maximum acceptable levels of Salmonella in pigs and pork are to be decided. A stochastic simulation model accounting for herd and abattoir information was used to evaluate food safety and economic consequences of different surveillance and control strategies, based among others on Danish surveillance data. An epidemiological module simulated the Salmonella carcass prevalence for different scenarios. Cost-effectiveness analysis was used to compare the costs of the different scenarios with their expected effectiveness. Herd interventions were not found sufficient to attain Salmonella carcass prevalence <1%. The cost-effectiveness of abattoir interventions changed with abattoir size. The most cost-effective strategy included the use of steam vacuum and steam ultrasound. Given uncertainty of the effect of steam vacuum and steam ultrasound, model results should be updated as more information becomes available. This framework contributes to informed decision-making for a more cost-effective surveillance and control of Salmonella in pigs and pork.


Assuntos
Inocuidade dos Alimentos/métodos , Carne/microbiologia , Gestão da Segurança/economia , Gestão da Segurança/métodos , Infecções por Salmonella/prevenção & controle , Salmonella/isolamento & purificação , Suínos/microbiologia , Animais , Análise Custo-Benefício , Dinamarca , Métodos Epidemiológicos , Humanos
6.
J Sports Med Phys Fitness ; 49(1): 54-63, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19188896

RESUMO

AIM: We aimed to explore associations between hours per week of sports training and molecular and cellular body composition components in adolescent athletes. METHODS: A total of 33 female athletes (13.3+/-3.5 years; 47.8+/-12.6 kg; 154+/-14.0 cm) and 90 male athletes (14.1+/-2.7 years; 60.6+/-17.8 kg; 167+/-16.2 cm) were measured. Based on the total of hours per week of training, athletes were divided into tertiles: <4.5 h/week; 4.5-8.9 h/week; 9 h/week. Dual-energy X-ray absorptiometry (DXA) was used to assess lean mass (lean), body fat (BF), percent body fat (%BF), bone mineral content (BMC) and density (BMD). Total body water (TBW), intracellular (ICW) and extracellular water (ECW) were assessed using bioelectrical impedance spectroscopy (BIS). Extracellular fluids (ECF), solids (ECS), body cell mass (BCM) and body fluid distribution (E/I) were calculated. Total hours per week of sports training (h/week), habitual physical activity (PA) and dietary were assessed by questionnaire. Statistics included analysis of covariance (ANCOVA) and simple regression analyses. RESULTS: Athletes training 9 h/week presented greater levels of TBW, lean, bone mass, BCM, and ECF and a lower %BF, independently of confounders. No significant differences in body composition estimates were found between athletes training <9 h/week. Hours per week of sports training were positively associated with fat free components, only in the group exercising 9 h/week CONCLUSIONS: In this group of Portuguese athletes from different sports we observed that training 9 h/week significantly improved body composition, especially fat free components, which may be important for a healthy growth and sports performance.


Assuntos
Desempenho Atlético/fisiologia , Composição Corporal/fisiologia , Água Corporal/fisiologia , Densidade Óssea/fisiologia , Exercício Físico/fisiologia , Líquido Extracelular/metabolismo , Esportes/fisiologia , Absorciometria de Fóton , Adolescente , Estudos Transversais , Impedância Elétrica , Feminino , Seguimentos , Humanos , Masculino , Inquéritos e Questionários , Fatores de Tempo
7.
J Dairy Sci ; 91(1): 109-18, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18096931

RESUMO

Somatic cell counts (SCC) in bulk tank milk delivered for human consumption are one of the indicators of milk quality and are used for milk pricing. Consequently, milk from cows with high SCC is frequently used by farmers for feeding of calves to lower the SCC in bulk tank milk. Young calves are more susceptible to Mycobacterium avium ssp. paratuberculosis (MAP) and may acquire the infection early in life through ingestion of MAP-contaminated milk. The occurrence of MAP antibodies can be an indicator of MAP shedding. Because MAP can be shed in milk from infected cows, and antibodies to MAP can be an indicator of the infectious status, an association between antibodies to MAP and high SCC can result in high-SCC milk being at risk of containing MAP. Feeding milk containing high SCC to susceptible calves may result in MAP infections. Somatic cell counts and MAP antibodies in milk were measured repeatedly in 7,251 cows from 26 Danish dairy herds to investigate the association between the occurrence of MAP antibodies and high SCC. The results of robust regression showed a log-linear relationship between the age at first positive ELISA and the age at first high SCC sample (R2 = 0.51). Of the 1,733 cows positive for MAP antibodies and with high SCC, high SCC was detected prior to MAP antibodies in 46% of the cows. Still, in 40% of the cows, MAP antibodies were detected before a high SCC. Therefore, the findings do not point to a causal relationship between high SCC and antibodies to MAP, but suggest a strong association and highlight a potentially increased risk of MAP transmission when milk with high SCC is fed to calves.


Assuntos
Anticorpos Antibacterianos/metabolismo , Doenças dos Bovinos/microbiologia , Doenças dos Bovinos/patologia , Leite/citologia , Mycobacterium avium subsp. paratuberculosis/imunologia , Paratuberculose/imunologia , Paratuberculose/patologia , Animais , Anticorpos Antibacterianos/análise , Bovinos , Doenças dos Bovinos/imunologia , Contagem de Células/veterinária , Estudos Transversais , Ensaio de Imunoadsorção Enzimática/veterinária , Feminino , Estudos Longitudinais , Leite/microbiologia , Paratuberculose/microbiologia , Paratuberculose/transmissão , Análise de Regressão
8.
Folia Microbiol (Praha) ; 48(5): 597-604, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-14976715

RESUMO

Recombinant haploid segregants were recovered in filamentous fungus Aspergillus nidulans (Eidam) G. Winter directly from the heterokaryons instead of diploid segregants (process described earlier as parameiosis). In spite of the reproductive complexity of A. nidulans, parameiosis has only now been observed in this fungus. Since parameiosis was characterized by the occurrence of genetic recombination inside heterokaryotic hyphae, master strains (uvs+) and uvs mutants with high rate of both mitotic exchanges or chromosome nondisjunction were used to form heterokaryons. Two groups of mitotic segregants were recovered directly from heterokaryons--aneuploids and stable haploids. Heterokaryons formed with uvs mutants produced a higher number of parameiotic segregants compared to the heterokaryons formed with uvs+ strains. Segregants were analyzed by nutritional markers, acriflavine resistance and conidial color. Normal meiotic behavior of haploid recombinants was observed.


Assuntos
Aspergillus nidulans/crescimento & desenvolvimento , Aspergillus nidulans/genética , Genes Fúngicos , Marcadores Genéticos , Haploidia , Meiose , Mitose , Fenótipo , Esporos Fúngicos/genética
9.
Acta Med Port ; 13(1-2): 1-6, 2000.
Artigo em Português | MEDLINE | ID: mdl-11059048

RESUMO

OBJECTIVE: To evaluate the relationship between the educational level, weight and obesity of young Portuguese males, aged 20 years. DESIGN: Cross-sectional study, based on the national military census files of 1990, provided by the military selection centres of Portugal (north, centre, south--including Azores and Madeira islands). SUBJECTS AND METHODS: In Portugal, all males aged 20 must present themselves to the military authorities to be submitted to a health exam in order to be screened for the armed forces. The data of 70,858 young Portuguese males aged 20 were gathered. Height and weight were measured by skilled teams. The educational level was confirmed by the presentation of educational attainment certificates. The population was divided into deciles of body mass index (BMI). The whole group was classified as obese or non-obese, according to a cut-off point of 27.8 Kg/sqm. The educational level was classified in four groups: group A--less than 5 years of schooling; group B--5 to 6 years; group C--7 to 9 years; group D--> or = 10 years. The level of education in each decile of BMI was determined and the percentage of obese subjects was calculated for each level of schooling. The odds of obesity associated with each group of schooling was determined as well as their 95% confidence intervals. Statistical significance was considered to exist when p < 0.05. RESULTS: The average BMI in the study population was 22.5 Kg/sqm. A slight increase in schooling was noticed from the lowest to the highest decile of BMI. The same result was obtained when we analysed the upper extreme of the BMI distribution in greater detail. According to our criteria for obesity, the percentages of obesity in each level of schooling were as follows: group A--4.2%; group B--5%; group C--5.1%; and group D--5.4%. The odds ratio (OR) of obesity according to each education level was higher in those with a higher level of education. In fact, those with 10 or more years of schooling presented an OR = 1.05(0.94;1.17) which was not statistically significant (ns) when compared to those with 7-9 years; while an OR = 1.08(0.97;1.21), was also ns when compared to those with 5-6 years, and, finally, an OR = 1.29(1.14;1.47) was statistically significant (p < 0.001) in comparison to those with only 0-4 years of schooling. CONCLUSIONS: As major conclusions one can say that the prevalence of obesity is low among young Portuguese males (4.9%), only 2.1% with a BMI > 30 Kg/sqm. Furthermore, our results show that, in Portugal, contrary to the results found mostly in western European countries, males aged 20 years with higher levels of education are slightly more prone to be obese than others with lower levels of schooling.


Assuntos
Escolaridade , Obesidade/epidemiologia , Adulto , Estudos Transversais , Humanos , Masculino , Portugal
10.
Bone ; 67: 193-9, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25016094

RESUMO

The study of bone mass distribution at proximal femur may contribute to understand the role of hip geometry on hip fracture risk. We examined how bone mineral density (BMD) of proximal femur adapts to inter individual variations in the femoral neck length (FNL), femoral neck width (FNW) and neck shaft angle (NSA). A parameterized and dimensionally scalable 3-D finite element model of a reference proximal femur geometry was incrementally adjusted to adopt physiological ranges at FNL (3.90-6.90cm), FNW (2.90-3.46cm), and NSA (109-141º), yielding a set of femora with different geometries. The bone mass distribution for each femur was obtained with a suitable bone remodelling model. The BMDs at the integral femoral neck (FN) and at the intertrochanteric (ITR) region, as well as the BMD ratio of inferomedial to superolateral (IM:SL) regions of FN and BMD ratio of FN:ITR were used to represent bone mass distribution. Results revealed that longer FNLs present greater BMD (g/cm(3)) at the FN, mainly at the SL region, and at the ITR region. Wider FNs were associated with reduced BMD at the FN, particularly at the SL region, and at the ITR region. Larger NSAs up to 129° were associated with BMD diminutions at the FN and ITR regions and with increases of the IM:SL BMD ratio while NSAs larger than 129° resulted in decrease of the IM:SL BMD ratio. These findings suggest hip geometry as moderator of the mechanical loading influence on bone mass distribution at proximal femur with higher FNL favoring the BMD of FN and ITR regions and greater FNW and NSA having the opposite effect. Augmented values of FNL and FNW seem also to favor more the BMD at the superolateral than at the inferomedial FN region.


Assuntos
Fêmur/anatomia & histologia , Articulação do Quadril/anatomia & histologia , Densidade Óssea , Biologia Computacional , Análise de Elementos Finitos , Humanos , Modelos Teóricos
11.
J Biomech ; 46(13): 2179-85, 2013 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-23910540

RESUMO

Individual differences in bone mass distribution at the proximal femur may be determined by daily weight-bearing physical activity (PA) since bone self-adapts according to the mechanical loads that is submitted. The aim of this study was to analyse computationally the effect of different weight-bearing PA types in the adaptation of the femoral neck (FN) by analysing regional differences in bone mineral density (BMD) at the integral FN and its superior, inferior, anterior and posterior subregions. To achieve this, it was adopted a 3-D femoral finite element (FE) model coupled with a suitable bone remodeling model. Different PA types were determined based both on ordinary lifestyle and mechanically more demanding PA as low magnitude impacts (L-I), moderate-magnitude impacts from odd directions (O-I) and high-magnitude vertical impacts (H-I). It was observed that as time spent in weight-bearing PA increases, BMD augment around the integral FN, but with different bone mass gain rates between subregions depending on the magnitude and directions of the hip contact forces; H-I was the type of weight-bearing PA which structurally most favor the gain of bone mass superiorly at the FN while both the H-I and the O-I types of PA promoted the largest bone mass gain rates at the anterior and posterior subregions of the FN. Because these types of weight-bearing PA were associated with a more uniform bone mass spatial distribution at the FN, they should provide a potential basis for targeted PA-based intervention programs for improving hip strength.


Assuntos
Remodelação Óssea/fisiologia , Colo do Fêmur/fisiologia , Modelos Biológicos , Atividade Motora/fisiologia , Densidade Óssea , Análise de Elementos Finitos , Humanos , Suporte de Carga
12.
Prev Vet Med ; 106(3-4): 308-14, 2012 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-22579393

RESUMO

Residues of pharmacological active substances or their metabolites might be found in food products from food-producing animals. Maximum Residue Limits for pharmacological active substances in foodstuffs of animal origin are established to assure high food safety standards. Each year, more than 20,000 samples are analysed for the presence of antibacterial residues in Danish pigs. This corresponds to 0.1% of the size of the slaughter pig population and more than 1% of the sows slaughtered. In this study, a Bayesian model was used to evaluate the Danish surveillance system accuracy and to investigate the impact of a potential risk-based sampling approach to the residue surveillance programme in Danish slaughter pigs. Danish surveillance data from 2005 to 2009 and limited knowledge about true prevalence and test sensitivity and specificity were included in the model. According to the model, the true antibacterial residue prevalence in Danish pigs is very low in both sows (∼0.20%) and slaughter pigs (∼0.01%). Despite data constraints, the results suggest that the current screening test used in Denmark presents high sensitivity (85-99%) and very high specificity (>99%) for the most relevant antibacterial classes used in Danish pigs. If high-risk slaughter pigs could be identified by taking into account antibacterial use or meat inspection risk factors, a potential risk-based sampling approach to antibacterial residue surveillance in slaughter pigs would allow reducing the sample size substantially, while increasing or maintaining the probability of detection. Hence, the antibacterial residue surveillance programme in Danish pigs would be more cost-effective than today.


Assuntos
Antibacterianos/análise , Resíduos de Drogas/análise , Inspeção de Alimentos/normas , Carne/normas , Suínos/metabolismo , Animais , Teorema de Bayes , Cromatografia Líquida de Alta Pressão/veterinária , Dinamarca , Cromatografia Gasosa-Espectrometria de Massas/veterinária , Espectrometria de Massas/veterinária , Sensibilidade e Especificidade
13.
Neuroscience ; 219: 23-32, 2012 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-22659015

RESUMO

Diabetic retinopathy and diabetic encephalopathy are two common complications of diabetes mellitus. The impairment of glutamatergic neurotransmission in the retina and hippocampus has been suggested to be involved in the pathogenesis of these diabetic complications. In this study, we investigated the effect of elevated glucose concentration and diabetes on the protein content and surface expression of AMPA receptor subunits in the rat retina and hippocampus. We have used two models, cultured retinal and hippocampal cells exposed to elevated glucose concentration and an animal model of streptozotocin-induced type 1 diabetes. The immunoreactivity of GluA1, GluA2 and GluA4 was evaluated by Western blot and immunocytochemistry. The levels of these subunits at the plasma membrane were evaluated by biotinylation and purification of plasma membrane-associated proteins. Elevated glucose concentration increased the total levels of GluA2 subunit of AMPA receptors in retinal neural cells, but not of the subunits GluA1 or GluA4. However, at the plasma membrane, elevated glucose concentration induced an increase of all AMPA receptor subunits. In cultured hippocampal neurons, elevated glucose concentration did not induce significant alterations in the levels of AMPA receptor subunits. In the retinas of diabetic rats there were no persistent changes in the levels of AMPA receptor subunits comparing to aged-matched control retinas. Also, no consistent changes were detected in the levels of GluA1, GluA2 or GluA4 in the hippocampus of diabetic rats. We demonstrate that elevated glucose concentration induces early changes in AMPA receptor subunits, mainly in GluA2 subunit, in retinal neural cells. Conversely, hippocampal neurons seem to remain unaffected by elevated glucose concentration, concerning the expression of AMPA receptors, suggesting that AMPA receptors are more susceptible to the stress caused by elevated glucose concentration in retinal cells than in hippocampal neurons.


Assuntos
Diabetes Mellitus Experimental/metabolismo , Hipocampo/metabolismo , Hiperglicemia/metabolismo , Receptores de AMPA/metabolismo , Retina/metabolismo , Animais , Western Blotting , Glucose , Imuno-Histoquímica , Neurônios/metabolismo , Ratos , Ratos Wistar
14.
Prev Vet Med ; 95(3-4): 231-8, 2010 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-20537741

RESUMO

The Danish Salmonella Surveillance-and-Control Programme in finisher pigs includes both herd and carcass surveillance. Herd surveillance consists of serological testing of meat-juice samples and classification of herds into three Salmonella seroprevalence levels. At the abattoirs, carcass swabs from five pigs are collected daily and analysed as a pooled sample to evaluate the Salmonella carcass prevalence. This study aimed to investigate factors associated with Salmonella carcass prevalence in Denmark. A total of 20,196 pooled carcass swabs collected in 23 Danish abattoirs were included in the analysis. A multilevel logistic regression model was used taking into account the two-level data structure (abattoir, carcass pool) and adjusting the parameter estimates to the random variation at the abattoir level. Study results indicated that carcass contamination was mainly influenced by the probability that at least one pig contributing to the pool was seropositive, the log-transformed number of seropositive pigs delivered to the abattoir on the same day and weekday. No other factors were found to be significant (P>0.05). Large reductions in the number of seropositive pigs delivered to slaughter are unlikely to result in large reductions of the Salmonella carcass prevalence, unless the number of seropositive pigs can be kept below approximately 200. On average, individual Salmonella carcass prevalence can be kept below 1% by keeping a Salmonella input to the abattoir below approximately 50 seropositive pigs. Variation between abattoirs suggested that improved hygiene practices in some of the abattoirs would reduce the Salmonella carcass prevalence further.


Assuntos
Matadouros , Intoxicação Alimentar por Salmonella/prevenção & controle , Salmonelose Animal/epidemiologia , Salmonella/imunologia , Doenças dos Suínos/epidemiologia , Matadouros/normas , Animais , Anticorpos Antibacterianos/sangue , Dinamarca/epidemiologia , Higiene , Prevalência , Fatores de Risco , Vigilância de Evento Sentinela/veterinária , Estudos Soroepidemiológicos , Suínos
15.
Neuroscience ; 169(4): 1589-600, 2010 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-20600668

RESUMO

Diabetes has been associated with cognitive and memory impairments, and with alterations in color and contrast perception, suggesting that hippocampus and retina are particularly affected by this disease. A few studies have shown that diabetes differentially affects neurotransmitter release in different brain regions and in retina, and induces structural and molecular changes in nerve terminals in both hippocampus and retina. We now detailed the impact over time of diabetes (2, 4 and 8 weeks of diabetes) on a large array of exocytotic proteins in hippocampus and retina.The exocytotic proteins density was evaluated by immunoblotting in purified synaptosomes and in total extracts of hippocampus and retina from streptozotocin-induced diabetic and age-matched control animals. Diabetes affected differentially the content of synaptic proteins (VAMP-2, SNAP-25, syntaxin-1, synapsin-1 and synaptophysin) in hippocampal and retinal nerve terminals. Changes were more pronounced and persistent in hippocampal nerve terminals. In general, the alterations in retina occurred earlier, but were transitory, with the exception of synapsin-1, since its content decreased at all time points studied. The content of synaptotagmin-1 and rabphilin 3a in nerve terminals of both tissues was not affected. In total extracts, no changes were detected in the retina, whereas in hippocampus SNAP-25 and syntaxin-1 content was decreased, particularly when more drastic changes were also detected in nerve terminals. These results show that diabetes affects the content of several exocytotic proteins in hippocampus and retina, mainly at the presynaptic level, but hippocampus appears to be more severely affected. These changes might influence neurotransmission in both tissues and may underlie, at least partially, previously detected physiological changes in diabetic humans and animal models. Since diabetes differentially affects exocytotic proteins, according to tissue and insult duration, functional studies will be required to assess the physiological impairment induced by diabetes on the exocytosis in central synapses.


Assuntos
Complicações do Diabetes/metabolismo , Diabetes Mellitus Experimental/metabolismo , Exocitose/fisiologia , Hipocampo/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Retina/metabolismo , Animais , Complicações do Diabetes/fisiopatologia , Diabetes Mellitus Experimental/fisiopatologia , Modelos Animais de Doenças , Hipocampo/fisiopatologia , Masculino , Ratos , Ratos Wistar , Retina/fisiopatologia
16.
Zoonoses Public Health ; 57 Suppl 1: 49-59, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21083818

RESUMO

Salmonella surveillance-and-control programs in pigs are highly resource demanding, so alternative cost-effective approaches are desirable. The aim of this study was to develop and evaluate a tool for predicting the Salmonella test status in pig herds based on herd information collected from 108 industrial farrow-to-finish pig herds in Portugal. A questionnaire including known risk factors for Salmonella was used. A factor analysis model was developed to identify relevant factors that were then tested for association with Salmonella status. Three factors were identified and labelled: general biosecurity (factor 1), herd size (factor 2) and sanitary gap implementation (factor 3). Based on the loadings in factor 1 and factor 3, herds were classified according to their biosecurity practices. In total, 59% of the herds had a good level of biosecurity (interpreted as a loading below zero in factor 1) and 37% of the farms had good biosecurity and implemented sanitary gap (loading below zero in factor 1 and loading above zero in factor 3). This implied that they, among other things, implemented preventive measures for visitors and workers entering the herd, controlled biological vectors, had hygiene procedures in place, water quality assessment, and sanitary gap in the fattening and growing sections. In total, 50 herds were tested for Salmonella. Logistic regression analysis showed that factor 1 was significantly associated with Salmonella test status (P = 0.04). Herds with poor biosecurity had a higher probability of testing Salmonella positive compared with herds with good biosecurity. This study shows the potential for using herd information to classify herds according to their Salmonella status in the absence of good testing options. The method might be used as a potentially cost-effective tool for future development of risk-based approaches to surveillance, targeting interventions to high-risk herds or differentiating sampling strategies in herds with different levels of infection.


Assuntos
Salmonelose Animal/microbiologia , Salmonella/imunologia , Vigilância de Evento Sentinela/veterinária , Doenças dos Suínos/microbiologia , Matadouros , Criação de Animais Domésticos , Animais , Anticorpos Antibacterianos/análise , Estudos Transversais , Ensaio de Imunoadsorção Enzimática/métodos , Ensaio de Imunoadsorção Enzimática/veterinária , Análise Fatorial , Fezes/microbiologia , Modelos Logísticos , Portugal , Valor Preditivo dos Testes , Medição de Risco , Fatores de Risco , Salmonella/classificação , Salmonelose Animal/epidemiologia , Salmonelose Animal/transmissão , Sorotipagem , Inquéritos e Questionários , Suínos , Doenças dos Suínos/epidemiologia
17.
Neuroscience ; 171(4): 981-92, 2010 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-20950673

RESUMO

A few studies have reported the existence of depletion of synaptic vesicles, and changes in neurotransmitter release and in the content of exocytotic proteins in the hippocampus of diabetic rats. Recently, we found that diabetes alters the levels of synaptic proteins in hippocampal nerve terminals. Hyperglycemia is considered the main trigger of diabetic complications, although other factors, such as low insulin levels, also contribute to diabetes-induced changes. Thus, the aim of this work was to evaluate whether long-term elevated glucose per se, which mimics prolonged hyperglycemia, induces significant changes in the content and localization of synaptic proteins involved in exocytosis in hippocampal neurons. Hippocampal cell cultures were cultured for 14 days and were exposed to high glucose (50 mM) or mannitol (osmotic control; 25 mM plus 25 mM glucose), for 7 days. Cell viability and nuclear morphology were evaluated by MTT and Hoechst assays, respectively. The protein levels of vesicle-associated membrane protein-2 (VAMP-2), synaptosomal-associated protein-25 (SNAP-25), syntaxin-1, synapsin-1, synaptophysin, synaptotagmin-1, rabphilin 3a, and also of vesicular glutamate and GABA transporters (VGluT-1 and VGAT), were evaluated by immunoblotting, and its localization was analyzed by immunocytochemistry. The majority of the proteins were not affected. However, elevated glucose decreased the content of SNAP-25 and increased the content of synaptotagmin-1 and VGluT-1. Moreover, there was an accumulation of syntaxin-1, synaptotagmin-1 and VGluT-1 in the cell body of some hippocampal neurons exposed to high glucose. No changes were detected in mannitol-treated cells. In conclusion, elevated glucose per se did not induce significant changes in the content of the majority of the synaptic proteins studied in hippocampal cultures, with the exception of SNAP-25, synaptotagmin-1 and VGluT-1. However, there was an accumulation of some proteins in cell bodies of hippocampal neurons exposed to elevated glucose, suggesting that the trafficking of these proteins to the synapse may be compromised. Moreover, these results also suggest that other factors, in addition to hyperglycemia, certainly contribute to alterations detected in synaptic proteins in diabetic animals.


Assuntos
Glucose/farmacologia , Hipocampo/citologia , Proteínas do Tecido Nervoso/metabolismo , Neurônios/efeitos dos fármacos , Proteína 2 Associada à Membrana da Vesícula/metabolismo , Proteínas de Transporte Vesicular/metabolismo , Animais , Células Cultivadas , Relação Dose-Resposta a Droga , Embrião de Mamíferos , Exocitose/efeitos dos fármacos , Exocitose/fisiologia , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Manitol/farmacologia , Neurônios/citologia , Neurônios/fisiologia , Gravidez , Transporte Proteico/efeitos dos fármacos , Ratos , Ratos Wistar , Fatores de Tempo
19.
Prev Vet Med ; 92(4): 301-8, 2009 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-19775766

RESUMO

In 1995, Denmark implemented a National Surveillance-and-Control Programme for Salmonella in finisher pigs. It was based on serological surveillance that enabled assignment of pig herds into three prevalence levels. Herds in levels 2 and 3 (corresponding to moderate and high Salmonella seroprevalence) were subjected to control measures, compulsory pen faecal sampling for bacteriological examination and serotyping. The initial dataset contained all herds that had mandatory bacteriological samples taken (N=3691 samples), out of which 44.4% were negative. Data from January 2005 to November 2007 obtained from the Danish programme were used to investigate the persistence of high serology (Salmonella index > or =40, corresponding to levels 2 or 3) for herds infected with one of the four most common Salmonella serotypes found in pig herds, S. Typhimurium, S. Derby, S. Infantis or S. Livingstone, using survival analysis. The effects of other potential factors, such as season, year, herd size and herd health status were also evaluated. An event was defined as return to low serology measured by a Salmonella index <40, for at least 6 consecutive months. A total of 1242 pig herds positive for one of the four serotypes of interest and 1433 events were included in the preliminary analysis using the Kaplan-Meyer method. The median high serology time (survival time) was 8 months and all explanatory variables were found to be significant (p<0.05), except the herd health status (p=0.49). Cox proportional hazards regression was used for herds infected with S. Typhimurium (N=1066) or S. Derby (N=314). Herds infected with S. Typhimurium presented a lower probability for returning to low serology (HR=0.69, p<0.001), compared to S. Derby, indicating longer high serology periods. Herds that started having high seroprevalence in Summer and Fall had a higher probability of returning to low serology compared to those starting in Winter and Spring (p<0.001). Compared to 2005, periods with high Salmonella serology were fewer and shorter in 2006 and 2007 (p<0.001). A positive impact of herd size was found, with larger herds being associated with shorter high serology periods, compared to smaller herds (p=0.012). This might indicate effective implementation of biosecurity measures in large herds. The health status of the herds was not found to be a significant factor (p=0.87), which might reflect that biosecurity measures in place in SPF herds are not effective for clearing Salmonella infections.


Assuntos
Salmonelose Animal/imunologia , Salmonella/imunologia , Doenças dos Suínos/microbiologia , Animais , Anticorpos Antibacterianos/sangue , Dinamarca/epidemiologia , Fezes/microbiologia , Estimativa de Kaplan-Meier , Salmonelose Animal/epidemiologia , Salmonelose Animal/microbiologia , Estações do Ano , Estudos Soroepidemiológicos , Sorotipagem , Suínos , Doenças dos Suínos/epidemiologia , Doenças dos Suínos/imunologia
20.
Arq. Inst. Biol. (Online) ; 77(3): 517-520, jul.-set. 2010. tab
Artigo em Português | VETINDEX, LILACS | ID: biblio-1391686

RESUMO

De outubro a dezembro de 2007, 845 amostras de sangue foram coletadas de 836 vacas (98,9%) e nove touros (1,1%), em um matadouro com inspeção federal no Estado do Tocantins. Cento e quarenta e duas amostras [(16,8%) IC 95% 14,3-19,4] tiveram reação positiva ao teste do antígeno acidificado e tamponado de Brucella abortus. Um touro foi positivo ao teste. Quinhentos e sessenta e um bovinos (66,3%) procederam do Estado do Pará e 284 (33,7%) do Estado do Tocantins. A prevalência de soropositividade foi de 17,2% [IC (95%) 13,6 - 19,9] e de 16,6% [IC (95%) 13,0 - 22,2] para o gado do Pará e Tocantins, respectivamente. Estas prevalências não são significativamente diferentes (p > 0,05). Nenhuma das vacas tinha registro de vacinação contra brucelose. Os exames "ante e post-mortem" não detectaram qualquer sinal ou lesão sugestiva à brucelose, como descargas vaginais, orquites, artrites ou bursites [(0,00%) IC 95% 0,00-0,43] em todos os bovinos da amostra. Esta situação, associada às altas prevalências da doença e à falta de diagnóstico da brucelose nos rebanhos, aumenta o número de bovinos infectados abatidos sob condições sanitárias inadequadas, o risco de contaminação dos trabalhadores e a colocação no mercado, sem restrição, de carne de animais infectados.


From October to December 2007, 845 blood samples were collected from 836 cows (98.9%) and nine bulls (1.1%), in a slaughterhouse with federal inspection in the state of Tocantins. One hundred and forty-two samples [(16.8%) 95% CI 14.3-19.4] had positive reaction to the plate agglutination test carried out with acidified and buffered antigen of Brucella abortus. One bull was positive to the test. Five hundred and sixty one bovines came from the State of Pará (66.3%) and 284 (33.7%) came from the State of Tocantins. The prevalence of serum positivity was 17.2% [CI (95%) 13.6 ­ 19.9] and 16.6% [CI (95%) 13.0 ­ 22.2] for cattle came from Pará and Tocantins, respectively, with no significant difference between these frequencies (p > 0.05). None of the cows had record of vaccination against brucellosis. "Ante and post-mortem" examinations could not find any sign or lesion attributable to brucellosis, such as vaginal discharges, joint inflammation or bursitis [(0.00%) 95% CI 0.00-0.43] in all bovines sampled. This situation, coupled with the high prevalence of the disease and the lack of brucellosis diagnostic at herds, increases the number of infected cattle slaughtered under inadequate sanitary conditions, the risk of contamination of workers and placing on the market, without restriction, the meat from infected animals.


Assuntos
Animais , Bovinos , Ferimentos e Lesões/veterinária , Brucella abortus/isolamento & purificação , Brucelose Bovina/sangue , Brucelose Bovina/epidemiologia , Brasil , Saúde Pública Veterinária , Inspeção Sanitária
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA