Detection of Leishmania braziliensis in human paraffin-embedded tissues from Tucumán, Argentina by polymerase chain reaction

American cutaneous leishmaniasis (ACL) is an endemic disease in Northern Argentina. We applied the polymerase chain reaction (PCR) followed by a hybridization labelled probe to 21 paraffin embedded human skin biopsies, already analyzed histologically, from leishmaniasis endemic areas in the province of Tucumán, Argentina. We used primers previously designed to detect a Leishmania-specific 120-base-pair fragment of kinetoplast DNA minicircle, other two primer pairs that amplify kDNA minicircles belonging to the L. braziliensis and L. mexicana complexes respectively, and specific oligonucleotide primers to detect L. (V.) braziliensis which amplify the sequence of the ribosomal protein L-14 of this species. The PCR-hybridization showed a sensitivity of 90.5% when compared to the histopathology test which was 61.9%. Five of the total samples analyzed were positive for the L. braziliensis complex whilst none was positive for the L. mexicana complex. The specific primers for L. (V.) braziliensis detected the parasite in four samples. These results are consistent with those reported for close endemic areas and demonstrate that the causative agent of human leishmaniasis in the analyzed cases was L. (V.) braziliensis. PCR should be used as a diagnostic tool for tegumentary leishmaniasis, especially in the mucosal form, and as a valuable technique for the identification of the Leishmania species that causes the disease in certain areas.     

Pentamidine is an antiparasitic and apoptotic drug that selectively modifies ubiquitin

We have determined the cytotoxic properties of pentamidine isethionate (2) towards the promastigotes of the protozoan parasite Leishmania infantum. The leishmanicidal activity of 2 was 60 times higher after 72 h of incubation than that of cisplatin (4). The pentamidine salt 2 induced a higher amount of programmed cell death (PCD) than cisplatin, which is associated with inhibition of DNA synthesis and cell-cycle arrest in the G2/M phase. Circular dichroism (CD) data indicate that binding of 2 to calf-thymus DNA (CT-DNA) induces conformational changes in the DNA double helix, consistent with a B-->A transition. Moreover, the interaction of 2 with ubiquitin led to a 6% increase in the beta-sheet content of the protein as observed by CD spectroscopy. Fluorescence-spectroscopy studies agreed with the CD data, showing that the pentamidine portion of 2 induces a significant decrease in the fluorescence of the Ub residues Phe4 and Phe45 located on the beta-cluster of the molecule, but not of Tyr59 on the alpha-cluster. These data indicate that pentamidine specifically modifies the beta-cluster, i.e., the 'basic face' of ubiquitin. Our results suggest that the biochemical mechanism of action of pentamidine may be a consequence of its dual binding to DNA and proteins.     

Investigating Gaze of Children with ASD in Naturalistic Settings

Background

Visual behavior is known to be atypical in Autism Spectrum Disorders (ASD). Monitor-based eye-tracking studies have measured several of these atypicalities in individuals with Autism. While atypical behaviors are known to be accentuated during natural interactions, few studies have been made on gaze behavior in natural interactions. In this study we focused on i) whether the findings done in laboratory settings are also visible in a naturalistic interaction; ii) whether new atypical elements appear when studying visual behavior across the whole field of view.

Methodology/Principal Findings

Ten children with ASD and ten typically developing children participated in a dyadic interaction with an experimenter administering items from the Early Social Communication Scale (ESCS). The children wore a novel head-mounted eye-tracker, measuring gaze direction and presence of faces across the child''s field of view. The analysis of gaze episodes to faces revealed that children with ASD looked significantly less and for shorter lapses of time at the experimenter. The analysis of gaze patterns across the child''s field of view revealed that children with ASD looked downwards and made more extensive use of their lateral field of view when exploring the environment.

Conclusions/Significance

The data gathered in naturalistic settings confirm findings previously obtained only in monitor-based studies. Moreover, the study allowed to observe a generalized strategy of lateral gaze in children with ASD when they were looking at the objects in their environment.     

Increased rat alveolar macrophage expression of functional iNOS induced by a Dirofilaria immitis immunoglobulin superfamily protein.

Dirofilaria immitis is a worldwide filarial nematode causing heartworm disease in dogs and cats. Several mosquito species, which are able to feed both on humans and animals, can transmit this parasite. Inflammatory progression of host tissues induced by parasites are mediated by several molecules, including nitric oxide (NO), which usually exerts deleterious effects on parasites and occasionally on the host. We analyze the in vitro effect of total D. immitis adult worm somatic antigens on na?ve rat alveolar macrophage NO production and further separation of parasite proteins to define specific D. immitis somatic molecules influencing host cell NO secretion. Additionally, we address the possible influence of Wolbachia spp. on the in vitro production of NO by macrophages. Our results demonstrate that D. immitis adult worm soluble antigens are able to specifically induce NO production from host macrophages. Furthermore, we demonstrated that this effect is due to nematode antigens rather than to defined components (LPS and metabolic molecules) derived from its endosymbiont, Wolbachia spp. In addition, we were able to isolate and identify one of the parasite specific components from the DiSo extract, denominated DiID35.3 and putatively belonging to the Immunoglobulin Superfamily Protein (ISP) group, triggering NO release from macrophages in a dose-dependent and specific manner.     

Lipoprotein alterations, abdominal fat distribution and breast cancer.

Plasma lipid profile and abdominal obesity have been associated with breast cancer risk, however published results have been inconsistent. To clarify these associations we studied lipid and lipoprotein alterations, obesity degree and body fat distribution, in 30 newly diagnosed breast cancer patients without treatment and 30 controls matched by age and menopausal status. Both pre and postmenopausal breast cancer patients presented higher body mass index, waist/hip ratio and insulin levels than their matched controls. An increase in triglycerides and a decrease in HDL-cholesterol, especially in the HDL2 subfraction, were observed in patients with breast cancer. Besides, HDL particle from these patients showed increased apo A1/HDL-cholesterol ratio. These alterations were correlated with waist/hip ratio. The association between lipoprotein alterations and abdominal obesity independent of menopausal status, in untreated newly diagnosed breast cancer patients is reported for the first time in this study.     

The discovery of moriniafungin, a novel sordarin derivative produced by Morinia pestalozzioides

A novel sordarin derivative, moriniafungin (1), containing a 2-hydroxysebacic acid residue linked to C-3' of the sordarose residue of sordarin through a 1,3-dioxolan-4-one ring was isolated from the fungus Morinia pestalozzioides. Isolation of moriniafungin employed a highly specific bioassay consisting of a panel of Saccharomyces cerevisiae strains containing chimeric eEF2 for Candida glabrata, Candida krusei, Candida lusitaniae, Crytpococcus neoformans, and Aspergillus fumigatus as well as wild type and human eEF2. Moriniafungin exhibited an MIC of 6 microg/mL versus Candida albicans and IC(50)'s ranging from 0.9 to 70 microg/mL against a panel of clinically relevant Candida strains. Moriniafungin was shown to inhibit in vitro translation in the chimeric S. cerevisae strains at levels consistent with the observed IC(50). Moriniafungin has the broadest antifungal spectrum and most potent activity of any natural sordarin analog identified to date.