RESUMO
Livestock constitute habitual hosts and carriers for several infectious pathogens which may represent a serious public health concern affecting the readiness of military forces and lead to wide economic losses. The present report aimed to investigate the prevalence of some haemopathogens infecting military livestock, particularly, dromedaries, sheep and horses using Giemsa-stained blood smears. A total of 300 animals (100 from each species) were selected, clinically examined and sampled. Trypanosoma spp. (22.0%), Anaplasma spp. (17.0%) and Babesia spp. (1.0%) were identified in camels' blood. Six dromedaries were found to be co-infected by Trypanosoma and Anaplasma organisms (6.0%). Camels of female gender, infested by ticks and showing clinical signs were statistically more infected by Trypanosoma spp., compared to those of male gender, free of ticks and apparently healthy (P= 0.027, 0.000 and 0.004, respectively). Babesia spp. infection (1.0%) was identified, for the first time in Tunisia, in one adult female camel that presented abortion and anemia. Anaplasma spp. was the only haemopathogen identified in examined sheep (6.0%) and horses (17.0%). Horses infested by Hippobosca equina flies and sheep infested by Rhipicephalus turanicus ticks were more infected by Anaplasma spp. than other non-infested animals (P=0.046 and 0.042, respectively). Hyalomma dromedarii, H. impeltatum and H. excavatum were the most prevalent diagnosed ticks removed from camels with an intensity of infestation of 1.2 ticks per animal. However, in sheep, only R. turanicus was identified. H. equina and Tabanus spp. were the potential hematophagous flies found in dromedaries and horses herds. This useful data must be taken into consideration during animal treatment and vectors' control programs in Tunisian military farms which help to limit the diffusion of vector-borne diseases, keep our livestock healthy and reduce economic losses.
Assuntos
Anaplasmose/epidemiologia , Babesiose/epidemiologia , Gado/parasitologia , Tripanossomíase/veterinária , Animais , Camelus/parasitologia , Dípteros/parasitologia , Feminino , Cavalos/parasitologia , Masculino , Instalações Militares , Carneiro Doméstico/parasitologia , Infestações por Carrapato/parasitologia , Infestações por Carrapato/veterinária , Tripanossomíase/epidemiologia , Tunísia/epidemiologiaRESUMO
Hepatitis B virus (HBV) infection is a global health problem. The mechanisms of immune tolerance in HBV infection are still unclear. The host immune response plays a critical role in determining the outcome of HBV infection. Human leucocyte antigen-G (HLA-G) is involved in immunotolerogenic process and infectious diseases. This study aimed to explore the implication of soluble HLA-G (sHLA-G) and its isoforms in HBV infection. Total sHLA-G (including shedding HLA-G1 and HLA-G5) was analysed by ELISA in 95 chronic HBV patients, 83 spontaneously resolvers and 100 healthy controls (HC). To explore the presence of sHLA-G dimers, we performed an immunoprecipitation and a Western blot analysis on positive samples for sHLA-G in ELISA. The serum levels of sHLA-G were significantly increased in patients with chronic HBV patients compared to spontaneously resolvers and HC (P<.0001). Interestingly, we found an increased level of sHLA-G1 in chronic HBV patients than in spontaneously resolvers and HC (P<.001). In addition, the expression of HLA-G5 seems to be higher in the sera of chronic HBV patients than spontaneously resolvers (P=.026). The analysis of HLA-G dimers showed the presence of homodimers in 93% of chronic HBV patients, 67% in spontaneously resolvers and 60% in HC. These results provide evidence that sHLA-G may have a crucial role in the outcome of HBV infection and could be proposed as a biomarker for infection outcome. Based on its tolerogenic function, HLA-G might be considered as a new promising immunotherapeutic approach to treat the chronic infection with HBV.
Assuntos
Antígenos HLA-G/sangue , Antígenos HLA-G/imunologia , Hepatite B Crônica/sangue , Hepatite B Crônica/epidemiologia , Adulto , Biomarcadores , Western Blotting , Feminino , Antígenos HLA-G/química , Vírus da Hepatite B/imunologia , Hepatite B Crônica/virologia , Humanos , Testes de Função Hepática , Masculino , Vigilância da População , Multimerização Proteica , Tunísia/epidemiologia , Adulto JovemRESUMO
The electroactive orthophosphate Na2Co2Fe(PO4)3 was synthesized using a solid state reaction. Its crystal structure was solved using the combination of powder X-ray- and neutron-diffraction data. This material crystallizes according to the alluaudite structure (S.G. C2/c). The structure consists of edge sharing [MO6] octahedra (M = Fe, Co) resulting in chains parallel to [-101]. These chains are linked together via the [PO4] tetrahedra to form two distinct tunnels in which sodium cations are located. The electrochemical properties of Na2Co2Fe(PO4)3 were evaluated by galvanostatic charge-discharge cycling. During the first discharge to 0.03 V, Na2Co2Fe(PO4)3 delivers a specific capacity of 604 mA h g(-1). This capacity is equivalent to the reaction of more than seven sodium ions per formula unit. Hence, this is a strong indication of a conversion-type reaction with the formation of metallic Fe and Co. The subsequent charge and discharge involved the reaction of fewer Na ions as expected for a conversion reaction. When discharged to 0.9 V, the material intercalated only one Na(+)-ion leading to the formation of a new phase Na3Co2Fe(PO4)3. This phase could then be cycled reversibly with an average voltage of 3.6 V vs. Na(+)/Na and a capacity of 110 mA h g(-1). This result is in good agreement with the theoretical capacity expected from the extraction/insertion of two sodium atoms in Na3Co2Fe(PO4)3.
RESUMO
A new orthophosphate α-Na2Ni2Fe(PO4)3 was synthesized using a solid state reaction route, and its crystal structure was determined from powder X-ray diffraction data. The physical properties of α-Na2Ni2Fe(PO4)3 were studied by magnetic and electrochemical measurements and by Mössbauer and Raman spectroscopy. α-Na2Ni2Fe(PO4)3 crystallizes according to a stuffed α-CrPO4-type structure with the space group Imma and the cell parameters a = 10.42821(12), b = 13.19862(15), c = 6.47634(8) Å, and Z = 4. The structure consists of a 3D-framework of octahedra and tetrahedra sharing corners and/or edges with channels along [100] and [010], in which the sodium atoms are located. The (57)Fe Mössbauer spectrum indicates that the Fe(3+) cation is distributed over two crystallographic sites implying the presence of a Ni(2+)/Fe(3+) statistical disorder. Magnetic susceptibility follows the Curie-Weiss behavior above 100 K with θ = -114.3 K indicating the occurrence of predominant antiferromagnetic interactions. Electrochemical tests indicate that during the first discharge to 1 V vs. Na(+)/Na in a sodium cell, one Na(+) ion could be inserted into the α-Na2Ni2Fe(PO4)3 structure. This has led to the formation of a new phase Na3Ni2Fe(PO4)3 which was found to be promising as a positive electrode material for sodium batteries. When α-Na2Ni2Fe(PO4)3 is further discharged to 0.03 V, it delivers a capacity of 960 mA h g(-1). This corresponds to the intercalation of more than seven sodium atoms per formula unit which is an indication of a conversion-type behaviour with the formation of metallic Fe and Ni. When cycled in the voltage range 0.03-3 V vs. Na(+)/Na, at 20 °C, under the current rates of 50, 100, 200, and 400 mA g(-1), reversible capacities of 238, 196, 153, and 115 mA h g(-1), were obtained, respectively.
RESUMO
Identification of an HLA-G 14-bp Insertion/Deletion (Ins/Del) polymorphism at the 3' untranslated region of HLA-G revealed its importance in HLA-G mRNA stability and HLA-G protein level variation. We evaluated the association between the HLA-G 14-bp Ins/Del polymorphism in patients with chronic Hepatitis B virus (HBV) infection in a case-control study. Genomic DNA was extracted from 263 patients with chronic HBV hepatitis and 246 control subjects and was examined for the HLA-G 14-bp Ins/Del polymorphism by PCR. The polymorphic variants were genotyped in chronic HBV seropositive cases stratified according to HBV DNA levels, fibrosis stages and in a control population. There was no statistical significant association between the 14-bp Ins/Del polymorphism and increased susceptibility to HBV infection neither for alleles (P = 0.09) nor for genotypes (P = 0.18). The stratification of HBV patients based on HBV DNA levels revealed an association between the 14-bp Ins/Del polymorphism and an enhanced HBV activity with high HBV DNA levels. In particular, the Ins allele was significantly associated with high HBV DNA levels (P = 0.0024, OR = 1.71, 95% CI 1.2-2.4). The genotype Ins/Ins was associated with a 2.5-fold (95% CI, 1.29-4.88) increased risk of susceptibility to high HBV replication compared with the Del/Del and Ins/Del genotypes. This susceptibility is linked to the presence of two Ins alleles. No association was observed between the 14-bp Ins/Del polymorphism and fibrosis stage of HBV infection. We observed an association between the 14-bp Ins/Del polymorphism and high HBV replication characterized by high HBV DNA levels in chronic HBV patients. These results suggest a potential prognostic value for disease outcome evaluation.