RESUMO

During prolonged dehydration, body fluid homeostasis is challenged by extracellular fluid (ECF) hyperosmolality, which induce important functional changes in the hypothalamus, in parallel with other effector responses, such as the activation of the local renin-angiotensin system (RAS). Therefore, in the present study we investigated the role of sodium-driven ECF hyperosmolality on glial fibrillary acid protein (GFAP) immunoreactivity and protein expression, membrane capacitance, mRNA expression of RAS components and glutamate balance in cultured hypothalamic astrocytes. Our data show that hypothalamic astrocytes respond to increased hyperosmolality with a similar decrease in GFAP expression and membrane capacitance, indicative of reduced cellular area. Hyperosmolality also downregulates the transcript levels of angiotensinogen and both angiotensin-converting enzymes, whereas upregulates type 1a angiotensin II receptor mRNA. Incubation with hypertonic solution also decreases the immunoreactivity to the membrane glutamate/aspartate transporter (GLAST) as well as tritiated-aspartate uptake by astrocytes. This latter effect is completely restored to basal levels when astrocytes previously exposed to hypertonicity are incubated under isotonic conditions. Together with a direct effect on two important local signaling systems (glutamate and RAS), these synaptic rearrangements driven by astrocytes may accomplish for a coordinated increase in the excitatory drive onto the hypothalamic neurosecretory system, ultimately culminating with increased AVP release in response to hyperosmolality.

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Persistent methicillin-resistant Staphylococcus aureus (MRSA) infection in cystic fibrosis (CF) patients has been associated with a more rapid decline in lung function, increased hospitalisation and mortality. The aim of this study was to evaluate the clonal relationships among 116 MRSA isolates from 12 chronically colonised CF pediatric patients over a 6-year period in a Rio de Janeiro CF specialist centre. Isolates were characterised by antimicrobial resistance, SCCmec type, presence of Panton-Valentine Leukocidin (PVL) genes and grouped according to DNA macrorestriction profile by pulsed-field gel electrophoresis (PFGE) and spa gene type. High resistance rates were detected for erythromycin (78%) and ciprofloxacin (50%) and SCCmec IV was the most common type (72.4%). Only 8.6% of isolates were PVL positive. High genetic diversity was evident by PFGE (39 pulsotypes) and of nine that were identified spa types, t002 (53.1%) and t539 (14.8%) were the most prevalent. We conclude that the observed homogeneity of spa types within patients over the study period demonstrates the persistence of such strain lineages throughout the course of chronic lung infection.

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Albinism is a rare phenotype that affects the pigmentation in eyes, hair, and skin. The effects of albinism in color vision are still unclear. Our study aimed to evaluate the color vision phenotype and genotype of an albino capuchin monkey. An adult albino male capuchin monkey (Sapajus apella) had the L and M opsin gene analyzed, and was trained in a behavioral task of color discrimination. Color discrimination thresholds were determined along 20 chromatic axes around the background chromaticity. A color discrimination ellipse was drawn by interpolation among these thresholds. The albino monkey's behavioral color discrimination ellipse showed poor discrimination along the red-green axis indicating a deutan phenotype. Genetic analysis revealed only the presence of the L gene in the albino monkey. This result did not differ from that obtained with ten previously tested non-albino monkeys. Behavioral and molecular analyses agreed that the albino capuchin monkey had color vision similar to that of non-albino dichromat monkeys, suggesting no influence of albinism on color discrimination.

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We describe the first detection of a KPC-2- and QnrB-producing Enterobacter cloacae from a patient with cystic fibrosis. The blaKPC-2 and qnrB-1 genes were located in a 79.8-kb plasmid. The presence of blaKPC-2 and qnrB-1 genes was determined by PCR and sequencing. Mobilization of plasmid containing blaKPC2 gene was assayed by conjugation.

RESUMO

Splinted and unsplinted overdenture attachment systems have unique advantages and disadvantages. The aim of the present systematic review was to determine the influence of splinted and unsplinted overdenture attachment systems on the marginal bone loss, prosthetic complications and implant survival rate. PubMed/MEDLINE, Scopus and Cochrane databases were searched for articles published up to October 2017, using the following search terms: "overdenture AND attachment OR overdenture AND bar OR overdenture splinted." The PICO question "Do splinted overdenture attachment systems promote better clinical results in comparison to unsplinted systems?" was evaluated. Eligible studies included randomized controlled clinical trials, prospective studies with at least 10 participants and a minimum follow-up of 6 months, and studies published in English that compared splinted and unsplinted attachment systems within the same study. The 95% confidence interval (CI) was considered for all outcomes analysed. After completion of the different steps in the article selection process, nine articles were included in the qualitative and quantitative analyses. A total of 984 implants were placed in 380 patients (mean age: 62.8 years). The meta-analysis demonstrated no statistically significant differences between splinted and unsplinted attachment systems with regard to marginal bone loss (P = .39; MD: -0.11; 95% CI: -0.37 to 0.14), complications (P = .31; RR: 1.26; CI: 0.80-1.99) and implant survival rate (P = .14; RR: 0.37% CI: 0.10-1.36). In addition, splinted and unsplinted overdenture attachment systems achieved similar results with regard to marginal bone loss, prosthetic complications and implant survival rate.

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RESUMO

Acinetobacter spp. are important healthcare pathogens, being closely linked to antibiotic resistance and outbreaks worldwide. Although such species are rarely observed in patients with cystic fibrosis (CF), we describe the characteristics of 53 strains of Acinetobacter spp. isolated from the sputum of 39 Brazilian patients with CF. The species distribution was A. baumannii (n = 29), A. pittii (n = 13), A. nosocomialis (n = 8), A. seifertii (n = 1), A. soli (n = 1) and A. variabilis (n = 1) determined by partial rpoB gene sequencing. Sixteen strains (10 A. baumannii, 3 A. pittii and 3 A. nosocomialis) were multidrug-resistant (MDR) by disk diffusion test (30%) and eight MDR carbapenem-resistant A. baumannii strains harboured the bla OXA-23-like oxacillinase gene. Thirty-three sequence types (STs) were identified by multilocus sequence typing of which eight were novel (A. baumannii: 843, 844, 845, 847, 848; A. pitti: 643; A. nosocomialis: 862 and A. seifertii: 846); six STs (2 A. baumannii, 3 A. pittii and 1 A. nosocomialis) were found in more than one patient. Four strains of A. baumannii were assigned to two common clonal complexes (CCs), namely, CC1 (ST1, ST20 and ST160), and CC79 (ST79). This study underlines the extensive species diversity of Acinetobacter spp. strains in CF lung infections which may present difficulties for therapy due to significant antimicrobial resistance.

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RESUMO

In broiler breeder roosters, the weight of the testes is positively associated with daily sperm production and fertility. In birds, the testes are located in the coelomic cavity, not being accessible to reproductive evaluation as mammalian testes. The reproductive evaluation of roosters is based on phenotypic traits. Any changes on testes will be reflected on fertility levels. The aim of this paper was to evaluate the potential of association of phenotypic traits as body weight (BW), comb scores (COS), cloaca scores (CLS) and feet scores (FS) with testicular morphometric parameters in adult Cobb® Mx roosters in two ages (25 and 45 weeks of age). The low BW roosters had lower testes weight (TW), smaller seminiferous tubule diameter (STD) and lower comb and cloaca scores than the medium and high BW roosters (P≤0.05). Heavy roosters had the highest COS and bigger seminiferous epithelium height (SEH). There was no statistical difference between the BW categories in FS and volumetric proportion of seminiferous tubule (ST) and interstitial tissue (IT). Considering the age effect, roosters with 45 weeks of age had lower TW and ST than 25-week roosters. Positive, moderate and significant correlation was found between testes weight and phenotypic characteristics as BW, COS and CLS in 45week roosters. A positive, moderate and significant correlation was found between body weight and histologic testicular characteristics as STD and SHE in both evaluated ages. In conclusion, there is a regression in the testes weight with age and it is more intense in Cobb® Mx roosters with lower BW. Furthermore, it is concluded that the BW positively influences the testes weight and histological quality of the testes. COS and CLS can be used with moderate potential prediction to identify roosters with low testes weight at 45 weeks of age.(AU)

Em galos de matriz pesada sabe-se que o peso dos testículos pode ser associado positivamente com a produção diária de espermatozoides e que alterações nos testículos irão refletir na fertilidade. Nas aves, os testículos estão localizados dentro da cavidade celomática, e, portanto, não são acessíveis para exame andrológico direto, como em mamíferos. A avaliação reprodutiva de galos se baseia principalmente em características fenotípicas. Buscou-se avaliar o potencial de associação de alguns parâmetros fenotípicos, como peso corporal (PC), escores de crista (ECR), escores de cloaca (ECL) e escores de pés (EP), com parâmetros morfológicos de testículos em galos Cobb® Mx em duas idades (25 e 45 semanas de idade). Galos leves apresentaram menor peso testicular (PT), menor diâmetro de túbulo seminífero (DT), e menores ECR e ECL que galos médios e pesados (P≤0.05). Galos pesados apresentaram os maiores ECR e maiores valores para altura do epitélio seminífero (AE), e DT. Não houve diferença estatisticamente significativa entre as categorias de peso para escores de pé e proporções de túbulo seminífero (TS) e interstício (INT). Considerando-se o efeito da idade, galos com 45 semanas de idade apresentaram menores PT e TS que galos com 25 semanas de idade. Correlação positiva, moderada e significativa foi encontrada entre peso de testículo e características fenotípicas como ECR, ECL e PC em galos de 45 semanas de idade. Foi encontrada correlação positiva, moderada e significativa entre PC e características testiculares como DT e AE nas duas idades avaliadas. Conclui-se que em galos Cobb® Mx ocorre regressão do testículo com o avanço da idade, e ela é mais intensa em galos com menor peso corporal. Conclui-se que o PC tem influência positiva no peso e índices histomorfométricos dos testículos, e que escores de crista e de cloaca podem ser utilizados com potencial moderado de predição para identificar galos com baixo peso de testículos em galos com 45 semanas de idade.(AU)

Assuntos

RESUMO

In broiler breeder roosters, the weight of the testes is positively associated with daily sperm production and fertility. In birds, the testes are located in the coelomic cavity, not being accessible to reproductive evaluation as mammalian testes. The reproductive evaluation of roosters is based on phenotypic traits. Any changes on testes will be reflected on fertility levels. The aim of this paper was to evaluate the potential of association of phenotypic traits as body weight (BW), comb scores (COS), cloaca scores (CLS) and feet scores (FS) with testicular morphometric parameters in adult Cobb® Mx roosters in two ages (25 and 45 weeks of age). The low BW roosters had lower testes weight (TW), smaller seminiferous tubule diameter (STD) and lower comb and cloaca scores than the medium and high BW roosters (P≤0.05). Heavy roosters had the highest COS and bigger seminiferous epithelium height (SEH). There was no statistical difference between the BW categories in FS and volumetric proportion of seminiferous tubule (ST) and interstitial tissue (IT). Considering the age effect, roosters with 45 weeks of age had lower TW and ST than 25-week roosters. Positive, moderate and significant correlation was found between testes weight and phenotypic characteristics as BW, COS and CLS in 45week roosters. A positive, moderate and significant correlation was found between body weight and histologic testicular characteristics as STD and SHE in both evaluated ages. In conclusion, there is a regression in the testes weight with age and it is more intense in Cobb® Mx roosters with lower BW. Furthermore, it is concluded that the BW positively influences the testes weight and histological quality of the testes. COS and CLS can be used with moderate potential prediction to identify roosters with low testes weight at 45 weeks of age.(AU)

Em galos de matriz pesada sabe-se que o peso dos testículos pode ser associado positivamente com a produção diária de espermatozoides e que alterações nos testículos irão refletir na fertilidade. Nas aves, os testículos estão localizados dentro da cavidade celomática, e, portanto, não são acessíveis para exame andrológico direto, como em mamíferos. A avaliação reprodutiva de galos se baseia principalmente em características fenotípicas. Buscou-se avaliar o potencial de associação de alguns parâmetros fenotípicos, como peso corporal (PC), escores de crista (ECR), escores de cloaca (ECL) e escores de pés (EP), com parâmetros morfológicos de testículos em galos Cobb® Mx em duas idades (25 e 45 semanas de idade). Galos leves apresentaram menor peso testicular (PT), menor diâmetro de túbulo seminífero (DT), e menores ECR e ECL que galos médios e pesados (P≤0.05). Galos pesados apresentaram os maiores ECR e maiores valores para altura do epitélio seminífero (AE), e DT. Não houve diferença estatisticamente significativa entre as categorias de peso para escores de pé e proporções de túbulo seminífero (TS) e interstício (INT). Considerando-se o efeito da idade, galos com 45 semanas de idade apresentaram menores PT e TS que galos com 25 semanas de idade. Correlação positiva, moderada e significativa foi encontrada entre peso de testículo e características fenotípicas como ECR, ECL e PC em galos de 45 semanas de idade. Foi encontrada correlação positiva, moderada e significativa entre PC e características testiculares como DT e AE nas duas idades avaliadas. Conclui-se que em galos Cobb® Mx ocorre regressão do testículo com o avanço da idade, e ela é mais intensa em galos com menor peso corporal. Conclui-se que o PC tem influência positiva no peso e índices histomorfométricos dos testículos, e que escores de crista e de cloaca podem ser utilizados com potencial moderado de predição para identificar galos com baixo peso de testículos em galos com 45 semanas de idade.(AU)

Assuntos

RESUMO

Exposure to loud sounds has become increasingly common. The most common consequences of loud sound exposure are deafness and tinnitus, but emotional and cognitive problems are also associated with loud sound exposure. Loud sounds can activate the hipothalamic-pituitary-adrenal axis resulting in the secretion of corticosterone, which affects hippocampal synaptic plasticity. Previously we have shown that long-term exposure to short episodes of high intensity sound inhibited hippocampal long-term potentiation (LTP) without affecting spatial learning and memory. Here we aimed to study the impact of short term loud sound exposure on hippocampal synaptic plasticity and function. We found that a single minute of 110 dB sound inhibits hippocampal Schaffer-CA1 LTP for 24 hours. This effect did not occur with an 80-dB sound exposure, was not correlated with corticosterone secretion and was also observed in the perforant-dentate gyrus synapse. We found that despite the deficit in the LTP these animals presented normal spatial learning and memory and fear conditioning. We conclude that a single episode of high-intensity sound impairs hippocampal LTP, without impairing memory and learning. Our results show that the hippocampus is very responsive to loud sounds which can have a potential, but not yet identified, impact on its function.

Assuntos

RESUMO

Achromobacter spp. are opportunistic pathogens increasingly recovered from adult patients with cystic fibrosis (CF). We report the characterization of 122 Achromobacter spp. isolates recovered from 39 CF patients by multilocus sequence typing, virulence traits, and susceptibility to antimicrobials. Two species, A. xylosoxidans (77%) and A. ruhlandii (23%) were identified. All isolates showed a similar biofilm formation ability, and a positive swimming phenotype. By contrast, 4·3% and 44·4% of A. xylosoxidans and A. ruhlandii, respectively, exhibited a negative swarming phenotype, making the swimming and swarming abilities of A. xylosoxidans significantly higher than those of A. ruhlandii. A. xylosoxidans isolates from an outbreak clone also exhibited significantly higher motility. Both species were generally susceptible to ceftazidime, ciprofloxacin, imipenem and trimethoprim/sulphamethoxazole and there was no significant difference in susceptibility between isolates from chronic or sporadic infection. However, A. xylosoxidans isolates from chronic and sporadic cases were significantly more resistant to imipenem and ceftazidime than isolates of the outbreak clone.

Assuntos

RESUMO

ABSTRACT In broiler breeder roosters, the weight of the testes is positively associated with daily sperm production and fertility. In birds, the testes are located in the coelomic cavity, not being accessible to reproductive evaluation as mammalian testes. The reproductive evaluation of roosters is based on phenotypic traits. Any changes on testes will be reflected on fertility levels. The aim of this paper was to evaluate the potential of association of phenotypic traits as body weight (BW), comb scores (COS), cloaca scores (CLS) and feet scores (FS) with testicular morphometric parameters in adult Cobb® Mx roosters in two ages (25 and 45 weeks of age). The low BW roosters had lower testes weight (TW), smaller seminiferous tubule diameter (STD) and lower comb and cloaca scores than the medium and high BW roosters (P0.05). Heavy roosters had the highest COS and bigger seminiferous epithelium height (SEH). There was no statistical difference between the BW categories in FS and volumetric proportion of seminiferous tubule (ST) and interstitial tissue (IT). Considering the age effect, roosters with 45 weeks of age had lower TW and ST than 25-week roosters. Positive, moderate and significant correlation was found between testes weight and phenotypic characteristics as BW, COS and CLS in 45week roosters. A positive, moderate and significant correlation was found between body weight and histologic testicular characteristics as STD and SHE in both evaluated ages. In conclusion, there is a regression in the testes weight with age and it is more intense in Cobb® Mx roosters with lower BW. Furthermore, it is concluded that the BW positively influences the testes weight and histological quality of the testes. COS and CLS can be used with moderate potential prediction to identify roosters with low testes weight at 45 weeks of age.

RESUMO Em galos de matriz pesada sabe-se que o peso dos testículos pode ser associado positivamente com a produção diária de espermatozoides e que alterações nos testículos irão refletir na fertilidade. Nas aves, os testículos estão localizados dentro da cavidade celomática, e, portanto, não são acessíveis para exame andrológico direto, como em mamíferos. A avaliação reprodutiva de galos se baseia principalmente em características fenotípicas. Buscou-se avaliar o potencial de associação de alguns parâmetros fenotípicos, como peso corporal (PC), escores de crista (ECR), escores de cloaca (ECL) e escores de pés (EP), com parâmetros morfológicos de testículos em galos Cobb® Mx em duas idades (25 e 45 semanas de idade). Galos leves apresentaram menor peso testicular (PT), menor diâmetro de túbulo seminífero (DT), e menores ECR e ECL que galos médios e pesados (P0.05). Galos pesados apresentaram os maiores ECR e maiores valores para altura do epitélio seminífero (AE), e DT. Não houve diferença estatisticamente significativa entre as categorias de peso para escores de pé e proporções de túbulo seminífero (TS) e interstício (INT). Considerando-se o efeito da idade, galos com 45 semanas de idade apresentaram menores PT e TS que galos com 25 semanas de idade. Correlação positiva, moderada e significativa foi encontrada entre peso de testículo e características fenotípicas como ECR, ECL e PC em galos de 45 semanas de idade. Foi encontrada correlação positiva, moderada e significativa entre PC e características testiculares como DT e AE nas duas idades avaliadas. Conclui-se que em galos Cobb® Mx ocorre regressão do testículo com o avanço da idade, e ela é mais intensa em galos com menor peso corporal. Conclui-se que o PC tem influência positiva no peso e índices histomorfométricos dos testículos, e que escores de crista e de cloaca podem ser utilizados com potencial moderado de predição para identificar galos com baixo peso de testículos em galos com 45 semanas de idade.

RESUMO

High-intensity sound can induce seizures in susceptible animals. After repeated acoustic stimuli changes in behavioural seizure repertoire and epileptic EEG activity might be seen in recruited limbic and forebrain structures, a phenomenon known as audiogenic kindling. It is postulated that audiogenic kindling can produce synaptic plasticity events leading to the spread of epileptogenic activity to the limbic system. In order to test this hypothesis, we investigated if long-term potentiation (LTP) of hippocampal Schaffer-CA1 synapses and spatial navigation memory are altered by a repeated high-intensity sound stimulation (HISS) protocol, consisting of one-minute 120 dB broadband noise applied twice a day for 10 days, in normal Wistar rats and in audiogenic seizure-prone rats (Wistar Audiogenic Rats - WARs). After HISS all WARs exhibited midbrain seizures and 50% of these animals developed limbic recruitment, while only 26% of Wistar rats presented midbrain seizures and none of them had limbic recruitment. In naïve animals, LTP in hippocampal CA1 neurons was induced by 50- or 100-Hz high-frequency stimulation of Schaffer fibres in slices from both Wistar and WAR animals similarly. Surprisingly, HISS suppressed LTP in CA1 neurons in slices from Wistar rats that did not present any seizure, and inhibited LTP in slices from Wistar rats with only midbrain seizures. However HISS had no effect on LTP in CA1 neurons from slices of WARs. Interestingly HISS did not alter spatial navigation and memory in both strains. These findings show that repeated high-intensity sound stimulation prevent LTP of Schaffer-CA1 synapses from Wistar rats, without affecting spatial memory. This effect was not seen in hippocampi from audiogenic seizure-prone WARs. In WARs the link between auditory stimulation and hippocampal LTP seems to be disrupted which could be relevant for the susceptibility to seizures in this strain.

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RESUMO

Avaliou-se a proporção volumétrica dos constituintes do placentomo de vacas mestiças Holandês-Zebude diferentes ordens de parto, utilizando-se 15 fêmeas gestantes, sem retenção de placenta e classificadas em trêsgrupos de acordo com a ordem de parto: o G1 formado por cinco vacas de primeira ordem de parto, o G2 porcinco vacas de segunda e o G3 por cinco vacas de terceira ou mais ordens de parto. A proporção volumétrica doscomponentes estruturais estudados não diferiu estatisticamente entre os três grupos, exceto para o tecidoconjuntivo materno (CM) e o epitélio fetal (EF). As proporções volumétricas do tecido CM foram 31,36 ± 6,97no G1, 19,82 ± 4,06 no G2 e 19,38 ± 0,88 no G3, e observou-se diferença estatística significativa do G1 quandocomparado ao G2 e ao G3 (P < 0,05). Na proporção volumétrica do tecido EF, as médias do G1, G2 e G3 foram12,52 ± 2,57, 18,46 ± 3,11 e 22,04 ± 4,62, respectivamente. Para essa análise, houve diferença estatística entre oG1 e o G3 (P < 0,05), entretanto o G2 não diferiu estatisticamente do G1 e do G3 (P < 0,05). Conclui-se que oplacentomo de vacas de primeira ordem de parto exibe maior proporção do tecido conjuntivo materno emrelação às vacas de segundo ou mais partos e que ocorre aumento progressivo da proporção do epitélio fetal noplacentomo com o aumento do número de partos.

The volumetric proportion of the placentome was evaluated in crossbred Holstein-Zebu cows ofdifferent delivery orders. Fifteen pregnant cows without retained placenta were used and classified into threegroups according to the delivery order, being the first group (G1) formed by heifers, the second (G2) by cows insecond delivery and third (G3) by cows with two or more delivery orders. The volumetric proportion ofstructural components evaluated did not differ significantly among the three groups, except for the connectivematernal tissue (CM) and fetal epithelium (FE). Volumetric proportions of the CM were 31.36 ± 6.97 in G1,19.82 ± 4.06 in G2, and 19.38 ± 0.88 in G3, and the difference was statistically significant when comparing G1with G2 and G3 (P 0.05). It can be concluded that theplacentome of first-order cows exhibits a higher proportion of the maternal conjunctive tissue than the second ormore delivery orders, and that there is a progressive increase in the proportion of fetal epithelium in theplacentome with the increasing number of pregnancies.

Assuntos

RESUMO

Avaliou-se a proporção volumétrica dos constituintes do placentomo de vacas mestiças Holandês-Zebude diferentes ordens de parto, utilizando-se 15 fêmeas gestantes, sem retenção de placenta e classificadas em trêsgrupos de acordo com a ordem de parto: o G1 formado por cinco vacas de primeira ordem de parto, o G2 porcinco vacas de segunda e o G3 por cinco vacas de terceira ou mais ordens de parto. A proporção volumétrica doscomponentes estruturais estudados não diferiu estatisticamente entre os três grupos, exceto para o tecidoconjuntivo materno (CM) e o epitélio fetal (EF). As proporções volumétricas do tecido CM foram 31,36 ± 6,97no G1, 19,82 ± 4,06 no G2 e 19,38 ± 0,88 no G3, e observou-se diferença estatística significativa do G1 quandocomparado ao G2 e ao G3 (P < 0,05). Na proporção volumétrica do tecido EF, as médias do G1, G2 e G3 foram12,52 ± 2,57, 18,46 ± 3,11 e 22,04 ± 4,62, respectivamente. Para essa análise, houve diferença estatística entre oG1 e o G3 (P < 0,05), entretanto o G2 não diferiu estatisticamente do G1 e do G3 (P < 0,05). Conclui-se que oplacentomo de vacas de primeira ordem de parto exibe maior proporção do tecido conjuntivo materno emrelação às vacas de segundo ou mais partos e que ocorre aumento progressivo da proporção do epitélio fetal noplacentomo com o aumento do número de partos.(AU)

The volumetric proportion of the placentome was evaluated in crossbred Holstein-Zebu cows ofdifferent delivery orders. Fifteen pregnant cows without retained placenta were used and classified into threegroups according to the delivery order, being the first group (G1) formed by heifers, the second (G2) by cows insecond delivery and third (G3) by cows with two or more delivery orders. The volumetric proportion ofstructural components evaluated did not differ significantly among the three groups, except for the connectivematernal tissue (CM) and fetal epithelium (FE). Volumetric proportions of the CM were 31.36 ± 6.97 in G1,19.82 ± 4.06 in G2, and 19.38 ± 0.88 in G3, and the difference was statistically significant when comparing G1with G2 and G3 (P < 0.05). In the FE volumetric proportion the average for G1, G2 and G3 was 12.52 ± 2.57,18.46 ± 3.11 and 22.04 ± 4.62, respectively. For this analysis there was statistical difference between G1 and G3(P < 0.05), however G2 did not differ statistically from G1 and G3 (P > 0.05). It can be concluded that theplacentome of first-order cows exhibits a higher proportion of the maternal conjunctive tissue than the second ormore delivery orders, and that there is a progressive increase in the proportion of fetal epithelium in theplacentome with the increasing number of pregnancies.(AU)

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RESUMO

Foram avaliadas características morfológicas do corpo lúteo de 48 vacas Nelore gestantes obtidos de abatedouros. Os ovários com o corpo lúteo foram coletados, identificados e divididos em três grupos, considerando o estágio da gestação determinado pelo tamanho do feto: Grupo I - onze animais com gestação até 90 dias; Grupo 2 - vinte animais com gestação de 90 a 180 dias, e Grupo 3 - 17 animais com gestação de 180 a 261 dias. Todos os corpos lúteos foram dissecados, submetidos a processamento histológico e avaliados utilizando microscopia de luz. As características morfológicas das células luteais esteroidogênicas não mudou durante a gestação. Porém, foi observado um aumento de tecido conjuntivo, fibroblastos e matriz extracelular durante o final da gestação. Células em degeneração foram observadas em todos os períodos da gestação, mas com maior intensidade no fim do terceiro trimestre. Grânulos foram observados após a coloração com Tricrômico de Gomory e Xylidine Ponceau, caracterizados como grânulos de proteína. Nenhuma explicação foi encontrada na literatura para coloração de grânulos pelo Tricrômico de Gomory.

RESUMO

Foram avaliadas características morfológicas do corpo lúteo de 48 vacas Nelore gestantes obtidos de abatedouros. Os ovários com o corpo lúteo foram coletados, identificados e divididos em três grupos, considerando o estágio da gestação determinado pelo tamanho do feto: Grupo I - onze animais com gestação até 90 dias; Grupo 2 - vinte animais com gestação de 90 a 180 dias, e Grupo 3 - 17 animais com gestação de 180 a 261 dias. Todos os corpos lúteos foram dissecados, submetidos a processamento histológico e avaliados utilizando microscopia de luz. As características morfológicas das células luteais esteroidogênicas não mudou durante a gestação. Porém, foi observado um aumento de tecido conjuntivo, fibroblastos e matriz extracelular durante o final da gestação. Células em degeneração foram observadas em todos os períodos da gestação, mas com maior intensidade no fim do terceiro trimestre. Grânulos foram observados após a coloração com Tricrômico de Gomory e Xylidine Ponceau, caracterizados como grânulos de proteína. Nenhuma explicação foi encontrada na literatura para coloração de grânulos pelo Tricrômico de Gomory.(AU)

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RESUMO

Preclinical studies have shown that repeated stress experiences can result in an increase in the locomotor response to the subsequent administration of drugs of abuse, a phenomenon that has been termed behavioral cross-sensitization. Behavioral sensitization reflects neuroadaptive processes associated with drug addiction and drug-induced psychosis. Although cross-sensitization between stress- and drug-induced locomotor activity has been clearly demonstrated in adult rats, few studies have evaluated this phenomenon in adolescent rats. In the present study, we determined if the simultaneous exposure to stress and nicotine was capable of inducing behavioral sensitization to nicotine in adolescent and adult rats. To this end, adolescent (postnatal day (P) 28-37) and adult (P60-67) rats received nicotine (0.4 mg/kg, sc) or saline (0.9 percent NaCl, sc) and were immediately subjected to restraint stress for 2 h once a day for 7 days. The control group for stress was undisturbed following nicotine or saline injections. Three days after the last exposure to stress and nicotine, rats were challenged with a single dose of nicotine (0.4 mg/kg, sc) or saline and nicotine-induced locomotion was then recorded for 30 min. In adolescent rats, nicotine caused behavioral sensitization only in animals that were simultaneously exposed to stress, while in adult rats nicotine promoted sensitization independently of stress exposure. These findings demonstrate that adolescent rats are more vulnerable to the effects of stress on behavioral sensitization to nicotine than adult rats.

Assuntos

RESUMO

Preclinical studies have shown that repeated stress experiences can result in an increase in the locomotor response to the subsequent administration of drugs of abuse, a phenomenon that has been termed behavioral cross-sensitization. Behavioral sensitization reflects neuroadaptive processes associated with drug addiction and drug-induced psychosis. Although cross-sensitization between stress- and drug-induced locomotor activity has been clearly demonstrated in adult rats, few studies have evaluated this phenomenon in adolescent rats. In the present study, we determined if the simultaneous exposure to stress and nicotine was capable of inducing behavioral sensitization to nicotine in adolescent and adult rats. To this end, adolescent (postnatal day (P) 28-37) and adult (P60-67) rats received nicotine (0.4 mg/kg, sc) or saline (0.9% NaCl, sc) and were immediately subjected to restraint stress for 2 h once a day for 7 days. The control group for stress was undisturbed following nicotine or saline injections. Three days after the last exposure to stress and nicotine, rats were challenged with a single dose of nicotine (0.4 mg/kg, sc) or saline and nicotine-induced locomotion was then recorded for 30 min. In adolescent rats, nicotine caused behavioral sensitization only in animals that were simultaneously exposed to stress, while in adult rats nicotine promoted sensitization independently of stress exposure. These findings demonstrate that adolescent rats are more vulnerable to the effects of stress on behavioral sensitization to nicotine than adult rats.

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RESUMO

The glomus cells in the carotid bodies (CB) detect alterations in pH and pCO2 and low pO2 level in arterial blood. The carotid sinus nerve conveys the information related to the oxygen level to 2nd-order neurons in the nucleus tractus solitarius (NTS) via tractus solitarius (TS), which is part of the chemoreflex pathways. It has been demonstrated that in 2nd-order NTS neurons receiving inputs from the aortic depressor nerve (ADN), the TS stimulation presents high temporal fidelity. However, the temporal properties of synaptic activity in NTS neurons receiving inputs from CB were not yet fully investigated. Herein using patch-clamp recordings in NTS brainstem slices, we studied TS-evoked excitatory postsynaptic currents (TS-eEPSCs) on morphologically identified 2nd-order NTS neurons that receive afferent inputs from the CB and compared with 2nd-order ADN-NTS neurons recorded in the same experimental conditions. The amplitudes of TS-eEPSCs were similar in both groups, but the latencies and standard deviation (SD) of latency were significantly higher in the CB-NTS neurons (latency: 4±0.2 ms, SD: 0.49±0.03 ms) than in ADN-NTS neurons (latency: 3.3±0.3 ms, SD: 0.19±0.02 ms; P=0.049 for latency and P<0.001 for SD of latency). In a series of double-labeling experiments, we confirmed that some CB-NTS 2nd-order neurons send direct projections to the rostral ventrolateral medulla (RVLM). We conclude that: (a) CB-NTS 2nd-order neurons present temporally distinct postsynaptic currents when compared with ADN-NTS 2nd-order neurons; (b) low SD of latency of TS-eEPSCs is not necessarily a characteristic of all 2nd-order neurons in the NTS; and (c) the presence of direct connections between these 2nd-order neurons in the NTS and RVLM is indicative that these synaptic properties of CB-NTS neurons are relevant for the processing of respiratory and autonomic responses to chemoreflex activation.

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A proporção volumétrica dos constituintes do corpo lúteo foi estudada em 48 ovários de vacas Nelore gestantes, coletados em frigorífico e distribuídos em três grupos, considerando-se o terço da gestação. No primeiro terço, utilizaram-se 11 animais em gestação de até 90 dias; no segundo terço, 20 animais em gestação entre 91 e 180 dias, e no terceiro terço 17 animais em gestação entre 181 e 261 dias. O corpo lúteo foi dissecado e submetido a processamento histológico para avaliação em microscopia óptica. Os animais em gestação de até 90 dias apresentaram maior proporção volumétrica de células endoteliais e pericitos, e nos acima de 181 dias de gestação ocorreu menor proporção de citoplasma (42,7 por cento) e núcleo (5,1 por cento) de células lúteas esteroidogênicas, bem como aumento do tecido conjuntivo e fibroblastos (47,7 por cento).

The volumetric proportion of the corpus luteum was evaluated in 48 ovaries from pregnant Nelore cows slaughtered in abattoirs, and divided into three groups, considering the trimester of gestation, and classified by the size of the fetus: First trimester - eleven animals with gestation up to 90 days; Second trimester - twenty animals with gestation between 91 and 180 days, and Third trimester - 17 animals with gestation between 181 and 261 days. The corpus luteum was dissected and submitted to histological processing and evaluations under light microscopy. The animals with gestation up to 90 days presented a higher proportion of endotelial cells and pericites. In the Third trimester there occurred a smaller proportion of cytoplasm (42,7 percent) and nucleus (5,1 percent) of steroidogenic luteal cells, and an increase in the conjunctive tissue, fibroblasts (47,7 percent).

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