RESUMO
PURPOSE: To longitudinally evaluate the cortical thickness and deep gray matter structures volume, measured from T1 three-dimensional (3D) Gradient echo-weighted imaging, and white matter integrity, assessed from diffusion tensor imaging (DTI) of HIV-positive patients. MATERIALS AND METHODS: Twenty-one HIV-positive patients on stable highly active antiretroviral therapy (HAART) with CD4+ T lymphocytes count >200 cells/mL and viral load <50 copies/mL underwent two magnetic resonance imaging (MRI) scans with a median interval of 26.6 months. None of the patients had HIV-related dementia. T1 3D magnetization prepared rapid gradient echo-weighted imaging and DTI along 30 noncolinear directions were performed using a 1.5 Tesla MR scanner. FreeSurfer was used to perform cortical volumetric reconstruction and segmentation of deep gray matter structures. For tract-based spatial statistics analysis, a white matter skeleton was created, and a permutation-based inference with 5000 permutations, with a threshold of P < 0.05 was used to identify abnormalities in fractional anisotropy (FA). The median, radial, and axial diffusivities were also projected onto the mean FA skeleton. RESULTS: There were no significant differences in cortical thickness, deep gray matter structures volumes or diffusivity parameters between scans at the two time points (considering P < 0.05). CONCLUSION: No longitudinal differences in cortical thickness, deep gray matter volumes, or white matter integrity were observed in an HIV-positive population on stable HAART, with undetectable viral load and high CD4+ T lymphocytes count. J. Magn. Reson. Imaging 2016;44:1262-1269.
Assuntos
Imagem de Tensor de Difusão/métodos , Encefalite Viral/tratamento farmacológico , Encefalite Viral/patologia , Substância Cinzenta/patologia , Infecções por HIV/tratamento farmacológico , Infecções por HIV/patologia , Substância Branca/patologia , Adulto , Terapia Antirretroviral de Alta Atividade/métodos , Encefalite Viral/imunologia , Feminino , Substância Cinzenta/imunologia , Infecções por HIV/imunologia , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Tamanho do Órgão/imunologia , Resultado do Tratamento , Carga Viral/imunologia , Substância Branca/imunologiaRESUMO
When total splenectomy is inevitable, heterotopic splenic autotransplantation seems to be the only alternative to maintain the functions of the spleen. The present study was carried out to analyse the critical mass of splenic autotransplant (SAT) for the development of phagocytic activity in rats. Wistar rats were submitted to total splenectomy (TS) alone or in combination with slices of SAT ranging from an average rate of 21·9% (one slice) to 100% (five slices) of the total splenic mass implanted into the greater omentum. Sixteen weeks after the beginning of the experiment, the animals were inoculated intravenously with a suspension of Escherichia coli labelled with Tc-99m. After 20 min, the rats were killed and the liver, lung and spleen or SAT, as well as blood samples were removed to determine the percentage of labelled bacteria uptake in these tissues. As the percentage of the total splenic mass contained in the SAT increased, the bacteria remaining in the blood decreased. From the implant of 26% up to the implant of the total splenic mass (100%) there was no difference in the bacteria remaining in the blood between the healthy animals of the control group and those submitted to TS combined with SAT. This finding shows that the critical mass needed for the development of phagocytic activity of macrophages in splenic autotransplants in adult rats is 26% of the total splenic mass.
Assuntos
Macrófagos/imunologia , Fagocitose , Baço/imunologia , Baço/transplante , Animais , Escherichia coli/imunologia , Infecções por Escherichia coli/imunologia , Humanos , Macrófagos/microbiologia , Masculino , Omento/imunologia , Tamanho do Órgão/imunologia , Ratos , Ratos Wistar , Baço/anatomia & histologia , Esplenectomia , Transplante Autólogo/imunologiaRESUMO
Vanadium, an important air pollutant derived from fuel product combustion, aggravates respiratory diseases and impairs cardiovascular function. In contrast, its effects on immune response are conflicting. The aim of our work was to determine if spleens of vanadium-exposed CD1 mice showed histological lesions that might result in immune response malfunction. One hundred and twelve CD-1 male mice were placed in an acrylic box and inhaled 0.02 M vanadium pentoxide (V2O5); actual concentration in chamber approximately 1.4 mg V2O5/m(3)) for 1 hr/d, twice a week, for 12 wk. Control mice inhaled only vehicle. Eight mice were sacrificed prior to the exposures. Eight control and eight V2O5-exposed mice were sacrificed 24 hr after the second exposure of each week until the 12-wk study was over. Another 8 mice that completed the 12-wk regimen were immunized with recombinant Hepatitis B surface antigen (HBsAg; three times over an 8-wk period) before sacrifice and analyses of their levels of anti-HBsAg antibody (HBSAb) using ELISA. In all studies, at sacrifice, blood samples were obtained by direct heart puncture and the spleen was removed, weighed and processed for H-E staining and quantitation of CD19 cells. The results indicated that the spleen weight of V2O5-exposed animals peaked at 9 wk (546 +/- 45 vs. 274 +/- 27 mg, p < 0.0001) and thereafter progressively decreased (321 +/- 39 mg at 12 wk, p < 0.001; control spleen = 298 +/- 35 mg). Spleens of V2O5-exposed animals showed an increased number of very large and non-clearly delimited germinal centers (that contained more lymphocytes and megakaryocytes) compared to those of control mice. In addition, their red pulp was poorly delimited and had an increase in CD19+ cells within hyperplasic germinal nodes. The mean HBsAb levels in immunized control mice were greater than that in the exposed hosts (i.e., OD = 0.39 +/- 0.03 vs. 0.11 +/- 0.05, p < 0.01). HBsAb avidity dropped to a value of 40 in V2O5-exposed animals vs. 86 in controls (p < 0.0001). We conclude that the chronic inhalation of V2O5, a frequent particle (PM(2.5)) component, induces histological changes and functional damage to the spleen, each of which appear to result in severe effects on the humoral immune response.
Assuntos
Poluentes Atmosféricos/toxicidade , Formação de Anticorpos/efeitos dos fármacos , Centro Germinativo/imunologia , Exposição por Inalação/efeitos adversos , Baço/imunologia , Compostos de Vanádio/toxicidade , Animais , Formação de Anticorpos/imunologia , Antígenos CD19/imunologia , Doenças Cardiovasculares/induzido quimicamente , Doenças Cardiovasculares/imunologia , Doenças Cardiovasculares/patologia , Centro Germinativo/patologia , Anticorpos Anti-Hepatite B/imunologia , Antígenos de Superfície da Hepatite B/administração & dosagem , Hiperplasia/induzido quimicamente , Hiperplasia/imunologia , Hiperplasia/patologia , Imunização , Linfócitos/imunologia , Linfócitos/patologia , Masculino , Megacariócitos/imunologia , Megacariócitos/patologia , Camundongos , Tamanho do Órgão/efeitos dos fármacos , Tamanho do Órgão/imunologia , Doenças Respiratórias/induzido quimicamente , Doenças Respiratórias/imunologia , Doenças Respiratórias/patologia , Baço/patologia , Fatores de TempoRESUMO
OBJECTIVES: Considering that sex steroids can influence the immune system, we studied the development of experimental autoimmune encephalomyelitis (EAE), a T-cell-mediated autoimmune disease of the central nervous system, and the concomitant cell-mediated immunity in gonadally intact and gonadectomized male Wistar rats given testosterone supplementation. METHODS/RESULTS: Sham-operated rats and surgically castrated animals were orally self-administered with vehicle or testosterone added in the water bottle for 20 days before EAE induction. The androgenic effect of oral testosterone self-administration was evidenced by changes in body weight, and in the weights of androgen-dependent testes and seminal vesicles. Testosterone administration reduced the incidence of clinical signs of EAE in sham-operated animals and reversed the clinical symptoms of the disease associated with castrated EAE animals. The clinical signs observed in the different groups correlated with changes in delayed-type hypersensitivity and mononuclear cell-proliferative responses to the encephalitogenic myelin basic protein. Moreover, testosterone but not cholesterol supplementation in vitro suppressed the proliferative response of mononuclear cells to myelin basic protein suggesting that testosterone may affect specific immune functions through direct actions on immune cells. Finally, self-administration of testosterone induced also elevated corticosterone levels that in sham-operated rats correlated with the low incidence of the disease and in gonadectomized animals could be involved in the remission of clinical symptoms of EAE. CONCLUSIONS: These results suggest that orally self-administered testosterone can modulate specific cellular immune responses and serum corticosterone levels leading to changes in the development of EAE.
Assuntos
Encefalomielite Autoimune Experimental/imunologia , Tolerância Imunológica/imunologia , Imunossupressores/farmacologia , Testosterona/farmacologia , Administração Oral , Animais , Peso Corporal/efeitos dos fármacos , Peso Corporal/imunologia , Proliferação de Células/efeitos dos fármacos , Colesterol/imunologia , Colesterol/farmacologia , Corticosterona/sangue , Modelos Animais de Doenças , Encefalomielite Autoimune Experimental/fisiopatologia , Tolerância Imunológica/efeitos dos fármacos , Imunidade Celular/efeitos dos fármacos , Imunidade Celular/imunologia , Imunossupressores/administração & dosagem , Imunossupressores/imunologia , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/imunologia , Ativação Linfocitária/efeitos dos fármacos , Ativação Linfocitária/imunologia , Masculino , Proteína Básica da Mielina/imunologia , Proteína Básica da Mielina/farmacologia , Orquiectomia , Tamanho do Órgão/efeitos dos fármacos , Tamanho do Órgão/imunologia , Ratos , Ratos Wistar , Autoadministração , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia , Testículo/efeitos dos fármacos , Testículo/imunologia , Testosterona/administração & dosagem , Testosterona/imunologiaRESUMO
OBJECTIVES: We studied the effect of a low-quality dietary protein on cellular proliferation and maturation in the thymus of growing rats over time. METHODS: After weaning Wistar rats were fed a diet containing 6.5 g/100 g of corn flour for 6, 10, 18, and 45 d (M groups). For comparison, other rats were fed a diet containing 6.5 g/100 g of casein (Cas groups), and well-nourished age-matched control rats were fed a commercial laboratory diet (C groups). Food intake, body weight, thymus weight, total number of thymocytes, and the percentages of CD43(+) and Thy1(+) thymocyte phenotypic antigen determinants were measured. RESULTS: M versus Cas and C groups showed significant differences (P < 0.01) in body and thymus weights after 6 d of feeding, and the total number of thymocytes and the percentages of CD43(+) and Thy1(+) were significantly lower after 10 d of feeding. The results indicated that consuming a cereal diet for short or long periods causes thymus atrophy in growing rats, with significant reductions in the total number of T-cells concomitant with increases in the number of immature thymocytes. CONCLUSIONS: The data showed that, in addition to low-protein concentration, low-quality dietary protein is a limiting factor in certain steps of cellular intrathymic pathways, probably related to the requirement of specific amino acids for optimal immune response.