Comparative Genomic Analyses of New and Old World Viscerotropic Leishmanine Parasites: Further Insights into the Origins of Visceral Leishmaniasis Agents.

Visceral leishmaniasis (VL), also known as kala-azar, is an anthropozoonotic disease affecting human populations on five continents. Aetiologic agents belong to the Leishmania (L.) donovani complex.

Whole-Genome Sequencing of Leishmania infantum chagasi Isolates from Honduras and Brazil.

This work reports on the whole-genome sequencing of Leishmania infantum chagasi from Honduras (Central America) and Brazil (South America).

Value of the oral swab for the molecular diagnosis of dogs in different stages of infection with Leishmania infantum.

This study was based on the need to employ a sensitive and specific method with samples that could be easily collected for diagnosing dogs infected with Leishmania infantum. To this end, we used real time-PCR (qPCR) to assess the value of the oral swab (OS) in detecting infected sick dogs (SD; n=62), including, for the first time, the analysis of apparently healthy infected dogs (AD; n=30), both from endemic areas for visceral leishmaniasis (VL). For comparison, we also evaluated the performance of the conjunctival swab (CS), blood (BL), lymph node (LN) and serology.

Serum Cytokine Responses over the Entire Clinical-Immunological Spectrum of Human Leishmania (L.) infantum chagasi Infection.

The clinical-immunological spectrum of human Leishmania (L.) infantum chagasi infection in Amazonian Brazil was recently reviewed based on clinical, DTH, and IFAT (IgG) evaluations that identified five profiles: three asymptomatic (asymptomatic infection, AI; subclinical resistant infection, SRI; and indeterminate initial infection, III) and two symptomatic (symptomatic infection, SI; American visceral leishmaniasis, AVL; and subclinical oligosymptomatic infection, SOI). TNF-α, IL-4, IL-6, and IL-10 serum cytokines were analyzed using multiplexed Cytometric Bead Array in 161 samples from endemic areas in the Brazilian Amazon: SI [AVL] (21 cases), III (49), SRI (19), SOI (12), AI (36), and a control group [CG] (24).

Preclinical diagnosis of American visceral leishmaniasis during early onset of human Leishmania (L.) infantum chagasi-infection.

American visceral leishmaniasis (AVL) is an infectious disease, often with long-duration evolution, caused by Leishmania (L.) infantum chagasi. However, although the disease is considered the major clinical manifestation of the link between L.

Salivary gland homogenates from wild-caught sand flies Lutzomyia flaviscutellata and Lutzomyia (Psychodopygus) complexus showed inhibitory effects on Leishmania (Leishmania) amazonensis and Leishmania (Viannia) braziliensis infection in BALB/c mice.

During the natural transmission of Leishmania parasites, the infected sand fly female regurgitates promastigotes into the host's skin together with its saliva. It has been reported that vector saliva contains immunomodulatory molecules that facilitate the establishment of infection. Thus, the main objective of this study was to evaluate the specificity of Lutzomyia (Lu.

Dynamic of the cellular immune response at the dermal site of Leishmania (L.) amazonensis and Leishmania (V.) braziliensis infection in Sapajus apella primate.

The purpose of this study was to characterize the immunopathological response in the skin of S. apella infected with Leishmania (L.) amazonensis and L.

Expression of inducible nitric oxide synthase in macrophages inversely correlates with parasitism of lymphoid tissues in dogs with visceral leishmaniasis.

Background: There are only a few studies reporting the role of nitric oxide metabolites for controlling macrophage intracellular parasitism, and these are controversial. Therefore, the present study aimed to evaluate the expression of inducible nitric oxide synthase (iNOS) in the lymph nodes and spleen of dogs affected by visceral leishmaniasis through immunohistochemistry and to determine its correlation with tissue parasite burden and serum interferon (IFN)-γ levels. Twenty-eight dogs were selected and assigned to one of two groups, symptomatic (n = 18) and asymptomatic (n = 10), according to clinical status and laboratory evaluation.

Severe visceral leishmaniasis in children: the relationship between cytokine patterns and clinical features.

Introduction: The relationship between severe clinical manifestations of visceral leishmaniasis (VL) and immune response profiles has not yet been clarified, despite numerous studies on the subject. This study aimed to investigate the relationship between cytokine profiles and the presence of immunological markers associated with clinical manifestations and, particularly, signs of severity, as defined in a protocol drafted by the Ministry of Health (Brazil).

Methods: We conducted a prospective, descriptive study between May 2008 and December 2009.

Treatment with triterpenic fraction purified from Baccharis uncinella leaves inhibits Leishmania (Leishmania) amazonensis spreading and improves Th1 immune response in infected mice.

The current medications used to treat leishmaniasis have many side effects for patients; in addition, some cases of the disease are refractory to treatment. Therefore, the search for new leishmanicidal compounds is indispensable. Recently, it was demonstrated that oleanolic- and ursolic-containing fraction from Baccharis uncinella leaves eliminated the promastigote and amastigote forms of Leishmania (Leishmania) amazonensis and L.

Epithelial cell turnover is increased in the excluded stomach mucosa after Roux-en-Y gastric bypass for morbid obesity.

Background: Mucosal alterations after Roux-en-Y gastric bypass for morbid obesity have not been clearly evaluated. This study aims to analyze the mucosal alterations (proliferative status (Ki-67); apoptosis (caspase-3 and BCL-2); hormonal function (gastrin)) in the excluded stomach.

Methods: Double-balloon enteroscopy was performed in 35 patients who underwent Roux-en-Y gastric bypass longer than 36 months.

Molecular markers of mucosa harboring gastric adenomas.

Context: Gastric adenoma is a precursor lesion of the adenocarcinoma.

Objective: To characterize gastric adenomas according to the mucin immunoexpression and to evaluate the immunoexpression of p53, p16ink4a, BCL-2, cyclin D, Ki-67, in the adenoma and in the gastric mucosa harboring adenoma.

Methods: Forty gastric specimens from 20 patients were classified as intestinal (MUC2-goblet cell mucin) or foveolar (MUC5AC-gastric-foveolar mucin) adenomas.

Asymptomatic dogs are highly competent to transmit Leishmania (Leishmania) infantum chagasi to the natural vector.

We evaluated the ability of dogs naturally infected with Leishmania (Leishmania) infantum chagasi to transfer the parasite to the vector and the factors associated with transmission. Thirty-eight infected dogs were confirmed to be infected by direct observation of Leishmania in lymph node smears. Dogs were grouped according to external clinical signs and laboratory data into symptomatic (n=24) and asymptomatic (n=14) animals.

A cross-sectional study on canine Leishmania (L.) infantum chagasi infection in Amazonian Brazil ratifies a higher prevalence of specific IgG-antibody response than delayed-type hypersensitivity in symptomatic and asymptomatic dogs.

This was a cross-sectional study which analyzed the prevalence and the clinical and immunological spectrum of canine Leishmania (L.) infantum chagasi infection in a cohort of 320 mongrel dogs living in an endemic area of American visceral leishmaniasis in the Amazonian Brazil by using, mainly, the indirect fluorescence antibody test (IFAT-IgG) and the delayed-type hypersensitivity (DTH), and the parasite research by the popliteal lymph node aspiration. The IFAT and DTH reactivity recognized three different immune response profiles: (1) IFAT((+))/DTH((-)) (107 dogs), (2) IFAT((-))/DTH((+)) (18 dogs), and (3) IFAT((+))/DTH((+)) (13 dogs), providing an overall prevalence of infection of 43% (138/320).

Susceptibility of peritoneal macrophage from different species of neotropical primates to ex vivo Leishmania (L.) infantum chagasi-infection.

This study examined the susceptibility of peritoneal macrophage (PM) from the Neotropical primates: Callithrix jacchus, Callithrix penicillata, Saimiri sciureus, Aotus azarae infulatus and Callimico goeldii to ex vivo Leishmania (L.) infantum chagasi-infection, the etiological agent of American visceral leishmaniasis (AVL), as a screening assay for evaluating the potential of these non-human primates as experimental models for studying AVL. The PM-susceptibility to infection was accessed by the PM-infection index (PMI) at 24, 72 h and by the mean of these rates (FPMI), as well as by the TNF-α, IL-12 (Capture ELISA) and Nitric oxide (NO) responses (Griess method).

Proteins of Leishmania (Viannia) shawi confer protection associated with Th1 immune response and memory generation.

Background: Leishmania (Viannia) shawi parasite was first characterized in 1989. Recently the protective effects of soluble leishmanial antigen (SLA) from L. (V.

Leishmania (Viannia) shawi purified antigens confer protection against murine cutaneous leishmaniasis.

Objective: Leishmania (Viannia) shawi was characterized only recently, and few studies concerning the immunogenic and protective properties of its antigens have been performed. The present study aimed to evaluate the protective potential of the five antigenic fractions isolated from L. (V.

Analysis of the protective potential of antigens released by Leishmania (Viannia) shawi promastigotes.

Leishmania (Viannia) shawi causes cutaneous lesions in humans. Parasite antigens conferring significant protection against American tegumentar leishmaniosis (ATL) might be important for the development of effective vaccine. Therefore, this work evaluates the protective effect of antigenic fractions released by L.

Human cutaneous leishmaniasis: interferon-dependent expression of double-stranded RNA-dependent protein kinase (PKR) via TLR2.

We investigated the type I interferon (IFN-1)/PKR axis in the outcome of the Leishmania (Leishmania) amazonensis infection, along with the underlying mechanisms that trigger and sustain this signaling pathway. Reporter assays of cell extracts from RAW-264.7 macrophages infected with L.

Evaluation of Helicobacter pylory colonization by serologic test (IgG) and dyspepsia in volunteers from the countryside of Monte Negro, in the Brazilian western Amazon region.

The present study intended to analyze the seroprevalence of Helicobacter pylori, IgG, and its relation to dyspepsia in a population from the western Amazon region. During the "Projeto Bandeira Científica", a University of São Paulo Medical School program, in Monte Negro's rural areas, state of Rondônia, 266 blood samples were collected from volunteers. The material was tested for IgG antibodies anti-Helicobacter pylori by ELISA method and the participants were also interviewed on dyspepsia, hygiene and social aspects.

Evaluation of anti-inflammatory activity of derivatives from aerial parts of Baccharis uncinella.

Context: Species of Baccharis exhibit antibiotic, antiseptic, and wound-healing properties, and have been used in the traditional medicine of South America for the treatment of inflammation, headaches, diabetes, and hepatobiliary disorders.

Objective: To investigate the anti-inflammatory activity of organic phases from EtOH extract of the aerial parts of Baccharis uncinella DC (Asteraceae).

Materials And Methods: The crude EtOH extract from the aerial parts of B.

Susceptibility of Cebus apella monkey (Primates: Cebidae) to experimental Leishmania (L.) infantum chagasi-infection.

In Amazonian Brazil, the Cebus apella monkey (Primates: Cebidae) has been associated with the enzootic cycle of Leishmania (V.) shawi, a dermotropic parasite causing American cutaneous leishmaniasis (ACL). It has also been successfully used as animal model for studying cutaneous leishmaniasis.

Leishmania sp. identification by PCR associated with sequencing of target SSU rDNA in paraffin-embedded skin samples stored for more than 30 years.

Paraffin-embedded samples commonly stored at educational and research institutions constitute tissues banks for follow-up or epidemiological studies; however, the paraffin inclusion process involves the use of substances that can cause DNA degradation. In this study, a PCR protocol was applied to identify Leishmania strains in 33 paraffin-embedded skin samples of patients with American cutaneous leishmaniasis. DNA was obtained by the phenol-chloroform protocol following paraffin removal and then used in PCR or nested PCR based on the nucleotide sequence of the small subunit ribosomal RNA (SSU rDNA).

Exacerbation of Leishmania (Viannia) shawi infection in BALB/c mice after immunization with soluble antigen from amastigote forms.

The present study aimed to evaluate the effects of immunization with soluble amastigote (AmaAg) and promastigote (ProAg) antigens from Leishmania (Viannia) shawi on the course of infection in BALB/c mice. After immunization with AmaAg, the challenged group showed greater lesion size and parasite load in the skin and lymph nodes, associated with diminished interleukin (IL)-2, IL-4, IL-10, interferon (IFN)-γ and nitrate levels in the supernatant of lymph node cell cultures, together with increases in transforming growth factor (TGF)-β concentrations and humoral immune response. In contrast, immunization with ProAg led to smaller lesion size with reduced numbers of viable parasites in the skin.