RESUMO
Seminiferous tubules physically connect to the rete testis through short segments called the transition region (TR). During fetal development, this specialized junction is considered the initial site where testis cords begin to form and to grow in length well beyond birth and into adulthood and form convoluted tubular cores. Mitotic activity of the Sertoli cell, the somatic cell of the epithelium, ceases before puberty, but modified Sertoli cells in the TR remain immature and capable of proliferation. This review presents what is known about this specialized region of the testis, with an emphasis on the morphological, molecular and physiological features, which support the hypothesis that this short region of epithelial transition serves as a specialized niche for undifferentiated Sertoli cells and spermatogonial stem cells. Also, the region is populated by an elevated number of immune cells, suggesting an important activity in monitoring and responding to any leakage of autoantigens, as sperm enter the rete testis. Several structure/function characteristics of the transition region are discussed and compared across species.
Assuntos
Células de Sertoli/citologia , Espermatogônias/citologia , Nicho de Células-Tronco , Animais , Masculino , Células de Sertoli/metabolismo , Espermatogênese , Espermatogônias/metabolismo , Junções Íntimas/metabolismo , Junções Íntimas/ultraestruturaRESUMO
BACKGROUND: Sperm cryopreservation of cockerels is a major challenge, and so far there is no adequate information to enable commercial use of frozen semen. OBJECTIVE: To test the toxicity of dimethylacetamide (DMA). MATERIALS AND METHODS: DMA was added at 3%, 6%, 9% and 12% to the freezing diluent, and maintained for equilibration with the semen sample for 1 min, 3 min, 5 min, 7 min and 9 min prior to freezing. Thawed semen was evaluated for kinetic characteristics by computer-assisted semen analysis (CASA) and for structural and functional properties by flow cytometry (plasma membrane rupture, mitochondrial functionality and plasma membrane functionality). RESULTS AND CONCLUSION: The addition of 6% DMA for 3-min equilibration resulted in the highest total and progressive motility, 42.0% and 36.9%, respectively. The point of intersection between a good protection and low plasma membrane rupture was obtained with the addition of 6% of DMA for 3-min equilibration with the rooster semen.
Assuntos
Acetamidas/farmacologia , Galinhas , Criopreservação/veterinária , Preservação do Sêmen/veterinária , Animais , Crioprotetores/farmacologia , Congelamento , Masculino , Sêmen , Análise do Sêmen , Motilidade dos Espermatozoides , EspermatozoidesRESUMO
Paracoccidioides brasiliensis is the major etiologic agent of Paracoccidioidomycosis (PCM), the most frequent human deep mycosis in Latin America. It is proposed that masking of ß-glucan in P. brasiliensis cell wall is a critical virulence factor that contributes to the development of a chronic disease characterized by a long period of treatment, which is usually toxic. In this context, the search for immunomodulatory agents for therapeutic purposes is highly desirable. One strategy is to use pattern recognition receptors (PRRs) ligands to stimulate the immune response mediated by phagocytes. Here, we sought to evaluate if Zymosan, a ß-glucan-containing ligand of the PRRs Dectin-1/TLR-2, would enhance phagocyte function and the immune response of mice challenged with P. brasiliensis. Dendritic cells (DCs) infected with P. brasiliensis and treated with Zymosan showed improved secretion of several proinflammatory cytokines and expression of maturation markers. In addition, when cocultured with splenic lymphocytes, these cells induced the production of a potential protective type 1 and 17 cytokine patterns. In macrophages, Zymosan ensued a significant fungicidal activity associated with nitric oxide production and phagolysosome acidification. Importantly, we observed a protective effect of Zymosan-primed DCs delivered intranasally in experimental pulmonary PCM. Overall, our findings support the potential use of ß-glucan-containing compounds such as Zymosan as an alternative or complementary antifungal therapy. LAY SUMMARY: We report for the first time that Paracoccidioides brasiliensis-infected phagocytes treated with Zymosan (cell wall extract from bakers' yeast) show enhanced cytokine production, maturation, and fungal killing. Also, Zymosan-primed phagocytes induce a protective immune response in infected mice.
Assuntos
Paracoccidioides/imunologia , Paracoccidioidomicose/tratamento farmacológico , Fagócitos/efeitos dos fármacos , Zimosan/farmacologia , Animais , Camundongos , Paracoccidioides/patogenicidade , Paracoccidioidomicose/imunologia , Fagócitos/imunologia , Virulência , Zimosan/uso terapêuticoRESUMO
The analysis of Salmonella in the feces and the birds environment is a way of monitoring the colonization in the flocks and verifying the need for the introduction of stricter controls, in such a way that the results of the tests should be known before being sent for slaughter. The polymerase chain reaction (PCR), as well as other rapid methods represent alternatives increasingly used to detect enteric pathogens, but they need proof of effectiveness for their wide use. The aim of this study was to evaluate the equivalence between the results obtained by the methods: real-time PCR (BAX® System), Modified Rappaport-Vassiliadis Semi-solid Medium (MSRV) (ISO 6579) and the traditional method of official reference in Brazil for research of S. Typhimurium and S. Enteritidis in poultry samples. Two hundred and fifty-two samples of disposable shoe covers (DSC) and 252 samples of feces were infected with an average of 2 to 3 log CFU/g of each serovar, and the same samples without fortification were evaluated by the three methods. Five hundred and four diagnoses were obtained with satisfactory results in terms of repeatability (greater than 80%), reproducibility (mean 83,1%), sensitivity (81% to 100%), specificity (95% to 100%), and accuracy (90% to 100%). The compliance test verified that there was not a significant difference between the alternative and the official methods, allowing us to state that the methodologies have had equivalent performances.
Assuntos
Animais , Biologia Celular , Fezes/microbiologia , Reação em Cadeia da Polimerase , Salmonella/imunologia , AvesRESUMO
The analysis of Salmonella in the feces and the birds environment is a way of monitoring the colonization in the flocks and verifying the need for the introduction of stricter controls, in such a way that the results of the tests should be known before being sent for slaughter. The polymerase chain reaction (PCR), as well as other rapid methods represent alternatives increasingly used to detect enteric pathogens, but they need proof of effectiveness for their wide use. The aim of this study was to evaluate the equivalence between the results obtained by the methods: real-time PCR (BAX® System), Modified Rappaport-Vassiliadis Semi-solid Medium (MSRV) (ISO 6579) and the traditional method of official reference in Brazil for research of S. Typhimurium and S. Enteritidis in poultry samples. Two hundred and fifty-two samples of disposable shoe covers (DSC) and 252 samples of feces were infected with an average of 2 to 3 log CFU/g of each serovar, and the same samples without fortification were evaluated by the three methods. Five hundred and four diagnoses were obtained with satisfactory results in terms of repeatability (greater than 80%), reproducibility (mean 83,1%), sensitivity (81% to 100%), specificity (95% to 100%), and accuracy (90% to 100%). The compliance test verified that there was not a significant difference between the alternative and the official methods, allowing us to state that the methodologies have had equivalent performances.(AU)
Assuntos
Animais , Salmonella/imunologia , Fezes/microbiologia , Biologia Celular , Reação em Cadeia da Polimerase , AvesRESUMO
Current antifungal drugs present poor effectiveness and there is no available vaccine for fungal infections. Thus, novel strategies to treat or prevent invasive mycosis, such as cryptococcosis, are highly desirable. One strategy is the use of immunomodulators of polysaccharide nature isolated from mushrooms. The purpose of the present work was to evaluate the immunostimulatory activity of ß-(1,3)-glucan-containing exopolysaccharides (EPS) from the edible mushrooms Auricularia auricula in phagocytes and mice infected with Cryptococcus neoformans. EPS triggered macrophages and dendritic cell activation upon binding to Dectin-1, a pattern recognition receptor of the C-type lectin receptor family. Engagement of Dectin-1 culminated in pro-inflammatory cytokine production and cell maturation via its canonical Syk-dependent pathway signaling. Furthermore, upon EPS treatment, M2-like phenotype macrophages, known to support intracellular survival and replication of C. neoformans, repolarize to M1 macrophage pattern associated with enhanced production of the microbicidal molecule nitric oxide that results in efficient killing of C. neoformans. Treatment with EPS also upregulated transcript levels of genes encoding products associated with host protection against C. neoformans and Dectin-1 mediated signaling in macrophages. Finally, orally administrated ß-glucan-containing EPS from A. auricular enhanced the survival of mice infected with C. neoformans. In conclusion, the results demonstrate that EPS from A. auricula exert immunostimulatory activity in phagocytes and induce host protection against C. neoformans, suggesting that polysaccharides from this mushroom may be promising as an adjuvant for vaccines or antifungal therapy.
Assuntos
Agaricales/química , Criptococose/prevenção & controle , Polissacarídeos Fúngicos/imunologia , Fagócitos/efeitos dos fármacos , Fagócitos/imunologia , beta-Glucanas/imunologia , Animais , Criptococose/imunologia , Cryptococcus neoformans/imunologia , Citocinas/imunologia , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/imunologia , Células Dendríticas/microbiologia , Fatores Imunológicos/farmacologia , Lectinas Tipo C/imunologia , Pneumopatias Fúngicas , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Macrófagos/microbiologia , Camundongos , Camundongos Endogâmicos C57BL , Fagócitos/microbiologia , Transdução de Sinais , beta-Glucanas/farmacologiaRESUMO
Tamoxifen (TAM) is a first generation-SERM administered for hormone receptor-positive (HER+) breast cancer in both pre- and post-menopausal patients and may undergo metabolic activation in organisms that share similar receptors and thus face comparable mechanisms of response. The present study aimed to assess whether environmental trace concentrations of TAM are bioavailable to the filter feeder M. galloprovincialis (100â¯ngâ¯L-1) and to the deposit feeder N. diversicolor (0.5, 10, 25 and 100â¯ngâ¯L-1) after 14â¯days of exposure. Behavioural impairment (burrowing kinetic), neurotoxicity (AChE activity), endocrine disruption by alkali-labile phosphate (ALP) content, oxidative stress (SOD, CAT, GPXs activities), biotransformation (GST activity), oxidative damage (LPO) and genotoxicity (DNA damage) were assessed. Moreover, this study also pertained to compare TAM cytotoxicity effects to mussels and targeted human (i.e. immortalized retinal pigment epithelium - RPE; and human transformed endothelial cells - HeLa) cell lines, in a range of concentrations from 0.5â¯ngâ¯L-1 to 50⯵gâ¯L-1. In polychaetes N. diversicolor, TAM exerted remarkable oxidative stress and damage at the lowest concentration (0.5â¯ngâ¯L-1), whereas significant genotoxicity was reported at the highest exposure level (100â¯ngâ¯L-1). In mussels M. galloprovincialis, 100â¯ngâ¯L-1 TAM caused endocrine disruption in males, neurotoxicity, and an induction in GST activity and LPO byproducts in gills, corroborating in genotoxicity over the exposure days. Although cytotoxicity assays conducted with mussel haemocytes following in vivo exposure was not effective, in vitro exposure showed to be a feasible alternative, with comparable sensitivity to human cell line (HeLa).
Assuntos
Tamoxifeno/farmacologia , Animais , Biotransformação , Bivalves , Dano ao DNA , Feminino , Brânquias , Humanos , Masculino , Estresse Oxidativo/efeitos dos fármacosRESUMO
OBJECTIVE: To test the role of escitalopram on blood pressure and heart rate of individuals with hypertension and depression. METHODS: A total of 30 individuals participated in this study who were being treated for hypertension and were diagnosed with major depression. Escitalopram (10-20 mg) was administered to 15 individuals, while the other 15 received placebo. These individuals were followed for 8 weeks with regular monitoring of blood pressure and heart rate. Scores on the Hamilton Depression Rating Scale were evaluated within the first, second, fourth, and eighth weeks of the study onset. RESULTS: Comparing with placebo, heart rate was lower in the escitalopram group (66.79 ± 9.85 vs. 74.10 ± 9.52 bpm, p = 0.044). There was not a significant decrease of systolic blood pressure (140.80 ± 16.48 vs 139.61 ± 18.92 mmHg, p = 0.85) and diastolic blood pressure (80.55 ± 12.64 vs 80.18 ± 16.36 mmHg, p = 0.94). CONCLUSION: Escitalopram decreases HR, but not BP, in individuals with hypertension and depression. Abbreviation: SH: systemic hypertension; BP: blood pressure; DSM: Diagnostic and Statistical Manual of Mental Disorders; SRQ 20: Self-Report Questionnaire; SCID: Structured Clinical Interview for DSM-IV; HR: heart rate; SNS: Sympathetic nervous system; HPA: hypothalamus-pituitary-adrenal axis; RAA: renin, angiotensin, aldosterone system; NE: norepinephrine; CSF: cerebrospinal fluid; HAM-D: Hamilton Depression Rating Scale; CRF: corticotropin releasing factor; ACTH: adrenocorticotropic hormone; BMI: Body mass index; SBP: systolic blood pressure; DBP: diastolic blood pressure; t: time.
Assuntos
Pressão Sanguínea/efeitos dos fármacos , Citalopram/farmacologia , Depressão/tratamento farmacológico , Frequência Cardíaca/efeitos dos fármacos , Hipertensão/fisiopatologia , Inibidores Seletivos de Recaptação de Serotonina/farmacologia , Citalopram/uso terapêutico , Depressão/complicações , Depressão/fisiopatologia , Método Duplo-Cego , Feminino , Humanos , Hipertensão/complicações , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Escalas de Graduação Psiquiátrica , Inibidores Seletivos de Recaptação de Serotonina/uso terapêuticoRESUMO
Objetivou-se determinar as possíveis fontes de contaminação de Yersinia enterocolitica em diferentes pontos do processo de ordenha de vacas leiteiras em oito propriedades da região de Pelotas, RS, ao longo de um ano. Foram analisadas amostras de leite cru de conjunto logo após a ordenha, água de estábulo leiteiro, mão de ordenhador, balde de recolhimento do leite e insuflador de teteiras. As amostras de leite cru e água foram coletadas em frascos estéreis, e as amostras de mão, balde e teteiras com zaragatoas estéreis. As amostras de leite cru foram submetidas a um pré-enriquecimento em água peptonada, sendo posteriormente incubadas em caldo PSTA, adicionado de ampicilina. As amostras de água foram filtradas em membrana de éster de celulose e incubadas em caldo TSB. As amostras de leite após incubação em PSTA, as membranas utilizadas na filtragem da água incubadas em TSB, bem como o material de mãos, balde e teteiras coletadas nas zaragatoas, foram semeados em ágar MacConkey e incubados para a obtenção de colônias. Colônias características foram analisadas por meio de duplex PCR para confirmação da espécie. Os perfis moleculares dos isolados de Y. enterocolitica foram comparados utilizando-se a técnica de rep-PCR. Y. enterocolitica foi isolada de 9,37% das amostras de leite, 6,25% das amostras de água e 12,5% das amostras de mão. Não houve similaridade no perfil de bandas dos isolados encontrados, entretanto foi identificada a presença de cepas diferentes na mesma amostra, demonstrando uma variedade grande de cepas distribuídas no ambiente. A presença de Y. enterocolitica em leite cru no Brasil é preocupante, já que uma quantidade considerável do produto ainda é comercializada de forma clandestina, expondo o consumidor ao risco de infecção pela bactéria, ao consumi-lo sem tratamento térmico adequado.(AU)
This work was performed in order to determine the possible Yersinia enterocolitica contamination sources at different points of the dairy cows milking process in eight properties of Pelotas, RS, in a year. Raw milk samples were analyzed immediately after milking, as well as water from milking parlor, milkers' hands, milk collection bucket, and inflator liners. The samples of raw milk and water were collected in sterile bottles and hand samples, and sterile swabs were used for the buckets and liners. The raw milk samples were subjected to a pre-enrichment peptone water buffered and subsequently incubated in PSTA broth with added ampicillin. Water samples were filtered through cellulose ester membrane and incubated in TSB medium. The milk samples after incubation in PSTA, the membranes used in water filtration were incubated in TSB and the material of the hands material, bucket and liners collected in the swabs were plated on MacConkey agar to obtain colonies. Characteristics of colonies were analyzed by duplex PCR to confirm the species. The molecular profiles of Y. enterocolitica isolates were compared using rep-PCR. Y. enterocolitica was isolated from 9,37% of milk samples, 6,25% of water samples and 12,5% of hand samples. There weren't similarities in the band profile of the isolates found; however, the presence of different strains was found in the same sample, demonstrating a variety of strains distributed in the environment. The presence of Y. enterocolitica in raw milk in Brazil is dangerous, considering that the product is sold clandestinely, exposing consumers to the risk of infection by the bacterium, when consuming it without proper heat treatment.(AU)
Assuntos
Leite/microbiologia , Yersinia enterocolitica/isolamento & purificação , Manipulação de Alimentos , Contaminação de Alimentos , Microbiologia da Água , Bovinos , Reação em Cadeia da Polimerase/veterinária , GastroenteriteRESUMO
Objetivou-se determinar as possíveis fontes de contaminação de Yersinia enterocolitica em diferentes pontos do processo de ordenha de vacas leiteiras em oito propriedades da região de Pelotas, RS, ao longo de um ano. Foram analisadas amostras de leite cru de conjunto logo após a ordenha, água de estábulo leiteiro, mão de ordenhador, balde de recolhimento do leite e insuflador de teteiras. As amostras de leite cru e água foram coletadas em frascos estéreis, e as amostras de mão, balde e teteiras com zaragatoas estéreis. As amostras de leite cru foram submetidas a um pré-enriquecimento em água peptonada, sendo posteriormente incubadas em caldo PSTA, adicionado de ampicilina. As amostras de água foram filtradas em membrana de éster de celulose e incubadas em caldo TSB. As amostras de leite após incubação em PSTA, as membranas utilizadas na filtragem da água incubadas em TSB, bem como o material de mãos, balde e teteiras coletadas nas zaragatoas, foram semeados em ágar MacConkey e incubados para a obtenção de colônias. Colônias características foram analisadas por meio de duplex PCR para confirmação da espécie. Os perfis moleculares dos isolados de Y. enterocolitica foram comparados utilizando-se a técnica de rep-PCR. Y. enterocolitica foi isolada de 9,37% das amostras de leite, 6,25% das amostras de água e 12,5% das amostras de mão. Não houve similaridade no perfil de bandas dos isolados encontrados, entretanto foi identificada a presença de cepas diferentes na mesma amostra, demonstrando uma variedade grande de cepas distribuídas no ambiente. A presença de Y. enterocolitica em leite cru no Brasil é preocupante, já que uma quantidade considerável do produto ainda é comercializada de forma clandestina, expondo o consumidor ao risco de infecção pela bactéria, ao consumi-lo sem tratamento térmico adequado.(AU)
This work was performed in order to determine the possible Yersinia enterocolitica contamination sources at different points of the dairy cows milking process in eight properties of Pelotas, RS, in a year. Raw milk samples were analyzed immediately after milking, as well as water from milking parlor, milkers' hands, milk collection bucket, and inflator liners. The samples of raw milk and water were collected in sterile bottles and hand samples, and sterile swabs were used for the buckets and liners. The raw milk samples were subjected to a pre-enrichment peptone water buffered and subsequently incubated in PSTA broth with added ampicillin. Water samples were filtered through cellulose ester membrane and incubated in TSB medium. The milk samples after incubation in PSTA, the membranes used in water filtration were incubated in TSB and the material of the hands material, bucket and liners collected in the swabs were plated on MacConkey agar to obtain colonies. Characteristics of colonies were analyzed by duplex PCR to confirm the species. The molecular profiles of Y. enterocolitica isolates were compared using rep-PCR. Y. enterocolitica was isolated from 9,37% of milk samples, 6,25% of water samples and 12,5% of hand samples. There weren't similarities in the band profile of the isolates found; however, the presence of different strains was found in the same sample, demonstrating a variety of strains distributed in the environment. The presence of Y. enterocolitica in raw milk in Brazil is dangerous, considering that the product is sold clandestinely, exposing consumers to the risk of infection by the bacterium, when consuming it without proper heat treatment.(AU)
Assuntos
Contaminação de Alimentos , Manipulação de Alimentos , Leite/microbiologia , Microbiologia da Água , Yersinia enterocolitica/isolamento & purificação , Bovinos , Gastroenterite , Reação em Cadeia da Polimerase/veterináriaRESUMO
In the development of new materials for orthopedic implants, special attention has been given to Ti alloys that show biocompatible alloy elements and that are capable of reducing the elastic modulus. Accordingly, Ti-Nb-Si alloys show great potential for application. Thus, this is a study on the microstructures and properties of Ti-35Nb-xSi alloys (x=0, 0.15, 0.35 and 0.55) (wt%) which were thermally treated and cooled under the following conditions: furnace cooling (FC), air cooling (AC), and water quenching (WQ). The results showed that Si addition is effective to reduce the density of omega precipitates making beta more stable, and to produce grain refinement. Silicides, referred as (Ti,Nb)3Si, were formed for alloys containing 0.55% Si, and its formation presumably occurred during the heating at 1000°C. In all cooling conditions, the hardness values increased with the increasing of Si content, as a result from the strong Si solid solution strengthening effect, while the elastic modulus underwent a continuous reduction due to the reduction of omega precipitates in beta matrix. Lower elastic moduli were observed in water-quenched alloys, which concentration of 0.15% Si was more effective in their reduction, with value around 65 GPa. Regarding Ti-35Nb-xSi alloys (x=0, 0.15 and 0.35), the "double yield point" phenomenon, which is typical of alloys with shape memory effect, was observed. The increase in Si concentration also produced an increase from 382 MPa to 540 MPa in the alloys' mechanical strength. Ti-35Nb-0.55Si alloy, however, showed brittle mechanical behavior which was related to the presence of silicides at the grain boundary.
Assuntos
Ligas/química , Fenômenos Mecânicos , Nióbio/química , Ortopedia , Próteses e Implantes , Silício/química , Titânio/química , Teste de Materiais , Relação Estrutura-Atividade , Água/químicaRESUMO
The acute administration of L-arginine (L-arg), a nitric oxide (NO) precursor, reduces lactate (LAC) concentration after exercise in healthy individuals. Lower concentration of L-arg may enhance the action of some inflammatory cytokines in HIV-1 infected patients. We tested the hypothesis that acute L-arg administration may reduce post-exercise blood LAC and inflammatory cytokines levels in HIV-infected patients. 10 HIV-infected men performed 2 maximal incremental cardiopulmonary exercise tests, separated by one week. 30 min before each test, patients received oral placebo or 20 g of L-arg, in random order. Blood LAC, tumor necrosis factor alpha (TNF-alpha), interleukin-6 (IL-6), and interleukin-10 (IL-10) were measured before and up to 60 min after exercise. L-arg administration had no significant effect on exercise performance. Compared to placebo, L-arg administration reduced maximal post-exercise blood LAC from 8.7±0.6 to 6.9±0.4 mmol.L-1 (p<0.05). L-arg administration had no significant effect on TNF-alpha or IL-10 concentrations, but increased post-exercise IL-6 (placebo=19±3pg.mL-1; L-arg=63±8 pg.mL-1; p<0.05). In HIV-1 infected men, acute administration of L-arg reduces post-exercise blood LAC and increases IL-6 levels, suggesting the activation of the L-arg-NO pathway, with possible anti-inflammatory consequences.
Assuntos
Arginina/administração & dosagem , Suplementos Nutricionais , Exercício Físico/fisiologia , Infecções por HIV/sangue , Interleucina-6/sangue , Ácido Láctico/sangue , Administração Oral , Terapia Antirretroviral de Alta Atividade , Infecções por HIV/tratamento farmacológico , Hemodinâmica , Humanos , Interleucina-10/sangue , Masculino , Pessoa de Meia-Idade , Respiração , Fator de Necrose Tumoral alfa/sangueAssuntos
Masculino , Feminino , Humanos , Comunicação , Comunicação não Verbal , Síndrome da Imunodeficiência Adquirida , LiteraturaRESUMO
Growth hormone (GH) use has been speculated to improve physical capacity in subjects without GH deficiency (GHD) through stimulation of collagen synthesis in the tendon and skeletal muscle, which leads to better exercise training and increased muscle strength. In this context, the use of GH in healthy elderly should be an option for increasing muscle strength. Our aim was to evaluate the effect of GH therapy on muscle strength in healthy men over 50 years old. Fourteen healthy men aged 50-70 years were evaluated at baseline for body composition and muscle strength (evaluated by leg press and bench press exercises, which focus primarily on quadriceps-lower body part and pectoralis major-upper body part-muscles, resp.). Subjects were randomised into 2 groups: GH therapy (7 subjects) and placebo (7 subjects) and reevaluated after 6 months of therapy. Thirteen subjects completed the study (6 subjects in the placebo group and 7 subjects in the GH group). Subjects of both groups were not different at baseline. After 6 months of therapy, muscle strength in the bench press responsive muscles did not increase in both groups and showed a statistically significant increase in the leg press responsive muscles in the GH group. Our study demonstrated an increase in muscle strength in the lower body part after GH therapy in healthy men. This finding must be considered and tested in frail older populations, whose physical incapacity is primarily caused by proximal muscle weakness. The trial was registered with NCT01853566.
RESUMO
Among hypertensive patients, cardiovascular disease morbidity is common, even in those who are adequately treated. New pharmacological strategies to mitigate the burden of arterial hypertension are needed. This 12-month, randomized, double-blind placebo-controlled study investigated the effect of statin (fluvastatin) treatment on ambulatory blood pressure (ABP), exercise blood pressure (EBP), myocardial structure, endothelial function and insulin resistance in 50 hypertensive patients. At baseline, the groups were comparable in terms of demographic characteristics, ABP, EBP, endothelial function and homeostasis model assessment of insulin resistance (HOMA-IR). At the end of the study, there was no difference between groups in terms of resting systolic blood pressure. However, maximum systolic EBP was lower in the treatment group than in the placebo group (175 ± 18 vs 192 ± 23 mm Hg, P<0.05), as was left ventricular mass index (LVMI; 82 ± 15 vs 100 ± 23, P<0.05), and HOMA-IR index was lower after fluvastatin treatment (2.77 ± 1.46 vs 3.33 ± 1.73, P<0.05). Changes in lipid profile were not correlated with blood pressure, endothelial function, LVMI or HOMA-IR data. In hypertensive patients, fluvastatin can improve maximum systolic EBP, myocardial remodelling and insulin resistance, independently of lipid profile variations and endothelial function.
Assuntos
Ácidos Graxos Monoinsaturados/uso terapêutico , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Hipertensão/tratamento farmacológico , Indóis/uso terapêutico , Resistência à Insulina , Miocárdio/patologia , Adulto , Pressão Sanguínea/efeitos dos fármacos , Método Duplo-Cego , Feminino , Fluvastatina , Humanos , Hipertensão/metabolismo , Hipertensão/patologia , Masculino , Pessoa de Meia-IdadeRESUMO
Carotid artery stenosis due to arteriosclerosis increases the risk of cerebral ischemia via embolic phenomena or reduced blood flow. The changes in cerebral perfusion that may occur after treatment are not clearly understood. This study evaluated the changes in cerebral microcirculation following carotid angioplasty with stenting (CAS) under cerebral protection with filters using ultrafast gradient echo (GRE) perfusion weighted imaging (PWI) with magnetic resonance imaging (MRI). Prospectively, 21 cervical carotid stenosis patients, mean age 69.95 years, underwent MRI 12 h before and 72 h after CAS. PWI parameters were collected for statistical analysis: cerebral blood volume (CBV), mean transit time (MTT) and time to peak (TTP). Statistical analysis was applied to absolute parameters and to values normalized against those from the contralateral parenchyma. The main finding of this study was improved hemodynamics for the normalized data after CAS, shown by reduced MTT (p<0.001) and TTP (p=0.019) in the territory fed by the middle cerebral artery ipsilateral to the CAS. Absolute data showed increased blood volume in the cerebral hemispheres after CAS, which was more accentuated on the stent side (p=0.016) than the contralateral side (p=0.029). Early improvements in cerebral perfusion, mainly seen in the normalized data, were clearly demonstrated in the timing parameters - TTP & MTT - after CAS.
Assuntos
Angioplastia , Estenose das Carótidas/patologia , Estenose das Carótidas/terapia , Circulação Cerebrovascular , Imageamento por Ressonância Magnética/métodos , Stents , Idoso , Idoso de 80 Anos ou mais , Volume Sanguíneo , Isquemia Encefálica/diagnóstico por imagem , Isquemia Encefálica/patologia , Estenose das Carótidas/diagnóstico por imagem , Angiografia Cerebral , Feminino , Humanos , Masculino , Microcirculação , Pessoa de Meia-Idade , Resultado do TratamentoRESUMO
Paracoccidioides brasiliensis, the etiologic agent of paracoccidioidomycosis, is a facultative intracellular human pathogen that can persist within macrophage phagolysosomes, indicating that the fungus has evolved defense mechanisms in order to survive under nutritionally poor environments. The analysis of P. brasiliensis transcriptome revealed several virulence factor orthologs of other microorganisms, including the glyoxylate cycle genes. This cycle allows the utilization of two-carbon (C2) compounds as carbon source in gluconeogenesis. Semiquantitative RT-PCR analyses revealed that these genes were upregulated when P. brasiliensis was recovered from murine macrophages, without any additional in vitro growth. The induction of this cycle, in response to macrophage microenvironments, was shown to be coordinated with the upregulation of the gluconeogenic phosphoenolpyruvate carboxykinase gene. In addition, assays employing RNA extracted from P. brasiliensis grown in a medium with acetate instead of glucose also showed increased levels of glyoxylate cycle transcripts. Our main results suggest that P. brasiliensis uses the glyoxylate cycle as an important adaptive metabolic pathway.
Assuntos
Glioxilatos/metabolismo , Macrófagos/microbiologia , Paracoccidioides/fisiologia , Paracoccidioidomicose/metabolismo , Animais , DNA Fúngico/análise , Regulação Fúngica da Expressão Gênica , Macrófagos/fisiologia , Camundongos , Paracoccidioides/genética , Paracoccidioidomicose/imunologia , RNA Fúngico/genética , RNA Fúngico/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Regulação para CimaRESUMO
The main objective of this paper is the characterization of the spectroscopic properties of new materials that are prospective laser media. This approach allows for the comparison of the properties of the Cr3+ in different environments. Here, we have studied the photoluminescence and optical absorption of Cs2NaScF6:Cr3+ single crystals. On the basis of near-infrared luminescence measurements at 2, 77, and 300 K the observed lines originated from the Cr3+-centres were associated with the 4T2(4F) --> 4A2(4F) transition and the lifetimes were obtained. In spite of the quenching observed as a function of temperature at least 10% of the 2 K emission intensity for Cs2NaScF6 doped with 1% of Cr3+ remains at room temperature. Besides, the 2 K emission broad band could be well described in terms of normal modes of the octahedral complex [CrF6]3-, and the Racah and crystal-field parameters calculated.
RESUMO
Disease cluster detection and evaluation have commonly used spatial statistics methods that scan the map with a fixed circular window to locate candidate clusters. Recently, there has been interest in searching for clusters with arbitrary shape. The circular scan test retains high power of detecting a cluster, but does not necessarily identify the exact regions contained in a non-circular cluster particularly well. We propose, implement and evaluate a new procedure that is fast and produces clusters estimates of arbitrary shape in a rich class of possible cluster candidates. We showed that our methods contain the so-called upper level set method as a particular case. We present a power study of our method and, among other results, the main conclusion is that the likelihood-based arbitrarily shaped scan method is not appropriate to find a cluster estimate. When the parameter space includes the set of all possible spatial clusters in a map, a large and discrete parameter space, maximum likely cluster estimates tend to overestimate the true cluster by a large extent. This calls for a new approach different from the maximum likelihood method for this important public health problem.
Assuntos
Análise por Conglomerados , Interpretação Estatística de Dados , Surtos de Doenças , Modelos Estatísticos , Brasil/epidemiologia , Simulação por Computador , Humanos , IncidênciaRESUMO
Paracoccidioides brasiliensis, the etiologic agent of paracoccidioidomycosis, is a dimorphic fungus, which is found as mycelia at 22-26 degrees C and as yeasts at 37 degrees C. A remarkable feature common to several pathogenic fungi is their ability to differentiate from mycelium to yeast morphologies, or vice-versa. Although P. brasiliensis is a recognized pathogen for humans, little is known about its virulence genes. In this sense, we performed a search for putative virulence genes in the P. brasiliensis transcriptome. BLAST comparative analyses were done among P. brasilienses assembled expressed sequence tags (PbAESTs) and the sequences deposited in GenBank. As a result, the putative virulence PbAESTs were grouped into five classes, metabolism-, cell wall-, detoxification-related, secreted factors, and other determinants. Among these, we have identified orthologs of the glyoxylate cycle enzymes, a metabolic pathway involved in the virulence of bacteria and fungi. Besides the previously described alpha- and beta-glucan synthases, orthologs to chitin synthase and mannosyl transferases, also important in cell wall synthesis and stabilization, were identified. With respect to the enzymes involved in the intracellular survival of P. brasiliensis, orthologs to superoxide dismutase, thiol peroxidase and an alternative oxidase were also found. Among the secreted factors, we were able to find phospholipase and urease orthologs in P. brasiliensis transcriptome. Collectively, our results suggest that this organism may possess a vast arsenal of putative virulence genes, allowing the survival in the different host environments.