Gentamicin-attenuated <i>Leishmania infantum</i>: A clinicopathological study in dogs

The clinicopathological changes following infection with an attenuated line of &lt;i&gt;Leishmania infantum&lt;/i&gt; (&lt;i&gt;L. infantum&lt;/i&gt; H-line) were evaluated in mixed breed dogs. Two groups of dogs were infected intravenously (i.v.) or intradermally (i.d.) with &lt;i&gt;L. infantum&lt;/i&gt; H-line and two control groups were infected i.v. or i.d. with &lt;i&gt;L. infantum&lt;/i&gt; wild-type (&lt;i&gt;L. infantum&lt;/i&gt; WT). None of the dogs, which were infected i.v. or i.d. with &lt;i&gt;L. infantum&lt;/i&gt; H-line, showed any abnormalities during the observation period. In contrast, two out of three dogs, which were infected i.v. with &lt;i&gt;L. infantum&lt;/i&gt; WT, developed clinical signs of disease. In addition, no histopathological changes were seen in the liver and spleen of the dogs infected with the attenuated line of parasite, whereas the histopathological changes in the two dogs infected i.v. with &lt;i&gt;L. infantum&lt;/i&gt; WT were severe in form and manifested by infiltration of high numbers of inflammatory cells. No promastigotes were found in cultures set up from spleens and livers of dogs infected with &lt;i&gt;L. infantum&lt;/i&gt; H-line at 12 months post-infection, whereas promastigotes were seen in the spleen and liver cultures from 2 dogs infected i.v. with &lt;i&gt;L. infantum&lt;/i&gt; WT. Serum levels of total IgG anti-Leishmania antibody were raised in all dogs. The antibody level in the serum of dogs infected i.v. with &lt;i&gt;L. infantum&lt;/i&gt; WT was higher than that in dogs infected with &lt;i&gt;L. infantum&lt;/i&gt; H-line. These results show no clinicopathological abnormalities in the dogs infected with gentamicin-attenuated &lt;i&gt;L. infantum&lt;/i&gt; H-line. Moreover, &lt;i&gt;L. infantum&lt;/i&gt; H-line induced IgG anti-Leishmania antibody in the dogs

Alteration in mononuclear cell subpopulations in dogs immunized with gentamicin-attenuated Leishmania infantum

The impact of immunization with gentamicin-attenuated Leishmania infantum (H-line) on the immunophenotypic profile of popliteal lymph node (PLN) and peripheral blood mononuclear cells (PBMCs) of dogs was assessed by flow cytometry and immunohistochemistry. Compared with the dogs infected with L. infantum wild-type (Group WT), there was a significantly higher percentage of CD4 + , CD44 + T cells and CD14 + , MHC-II + cells and a lower percentage of CD4 + CD25 + regulatory T cells in PLN of the immunized dogs with L. infantum H-line (Group H). The percentage of CD4 + and CD8 + T cells in PBMCs of immunized dogs was higher than that in dogs of Group WT. The CD4:CD8 ratio in PLN of dogs of Group H was significantly higher than that in dogs of Group WT. A significantly higher percentage of CD21 + B cells and a lower percentage of CD79b + cells were found in PLN of the immunized dogs compared with dogs of Group WT. Immunohistochemical investigation showed no parasites in the PLN of immunized dogs whereas there were parasites in the PLN of 60% of dogs infected with L. infantumWT. In this study, the immunophenotypic profile of mononuclear cells of the immunized dogs correlates with cellular immunity

Investigation on the effects of milling atmosphere on synthesis of barium ferrite/magnetite nanocomposite

In this research, barium ferrite /magnetite nanocomposites synthesized via a mechano-chemical route. Graphite was used in order to reduce hematite content of barium ferrite to magnetite to produce a magnetic nanocomposite. The effects of processing conditions on the powder characteristics were investigated by XRD, VSM, and HRTEM techniques. XRD results revealed that milling under air and argon atmospheres resulted in the appearance of Fe3O4 peaks beside BaFe12O19 peaks after 15 and 20 hrs milling, respectively. The intensity of Fe3O4 peaks in the XRD patterns increased by increasing the milling time. VSM studies revealed that saturation magnetization of the 40-hrs milled samples under air and argon atmospheres was 31.25 and 36.42 emu/g, respectively. This difference might be due to more Fe3O4 content in the latter sample. By annealing of the 40-hrs milled sample in air, saturation magnetization increased to 139.12 emu/g.Nanostructured MaterialsApplied Science