In primary human monocyte-derived macrophages exposed to Human immunodeficiency virus type 1, does the increased intracellular growth of Leishmania infantum rely on its enhanced uptake?

Concurrent uncontrolled development of human immunodeficiency virus type 1 (HIV-1) and Leishmania spp. is regarded as an emerging pathogenic combination in countries where human beings are exposed to these two micro-organisms. The present study was aimed at exploring whether HIV-1 development within a culture of human monocyte-derived macrophages (MDMs) affected the further development of luciferase-encoding Leishmania infantum using the luciferase activity as a readout assay.

Identification of developmentally-regulated proteins in Leishmania panamensis by proteome profiling of promastigotes and axenic amastigotes.

We have employed proteomics to identify proteins upregulated in the amastigote life-stage of Leishmaniapanamensis, using axenically-differentiated forms as models of authentic intracellular parasites. Resolution of the soluble proteomes of axenic amastigotes and promastigotes by two-dimensional electrophoresis (2DE) in the neutral pI range (5-7) revealed equivalent numbers of protein spots in both life-stages (644-682 using Coomassie Blue and 851-863 by silver staining). Although representing a relatively low proportion (8.

Resistance of Leishmania donovani to sodium stibogluconate is related to the expression of host and parasite gamma-glutamylcysteine synthetase.

Sequencing studies showed that the gamma-glutamylcysteine synthetase (gamma-GCS) heavy chain genes from sodium stibogluconate (SSG)-resistant (SSG-R) and SSG-susceptible (SSG-S) Leishmania donovani strains were identical, indicating that SSG resistance was related to quantitative differences in gamma-GCS expression rather than gene interstrain polymorphisms. In vitro infection of murine macrophages with the SSG-R strain, but not the SSG-S strain, down regulated expression of host gamma-GCS, which would result in a reduction in intramacrophage glutathione (GSH) levels and promote an oxidative intramacrophage environment. This would inhibit, or minimize, the reduction of SSG pentavalent antimony to its more toxic trivalent form.

A proteomic analysis of penicillin resistance in Streptococcus pneumoniae reveals a novel role for PstS, a subunit of the phosphate ABC transporter.

Resistance to penicillin is widespread in the Gram-positive bacterium Streptococcus pneumoniae, and while several mutations are known to be implicated in resistance other mechanisms are likely to occur. We used a proteomic screen of two independent mutants in which resistance was selected in vitro. We found a number of differentially expressed proteins including PstS, a subunit of the phosphate ABC transporter of S.

Live nonpathogenic parasitic vector as a candidate vaccine against visceral leishmaniasis.

To date, there are no proven vaccines against any form of leishmaniasis. The development of live attenuated vectors shows promise in the field of Leishmania vaccination because these organisms mimic more effectively the course of real infections and can elicit potent activation of the immune system. In the present study, we investigated the potential of a parasitic protozoan that is nonpathogenic to humans, Leishmania tarentolae, as a live candidate vaccine that efficiently targets dendritic cells and lymphoid organs, thus enhancing antigen presentation and consequently influencing the magnitude and quality of T-cell immune responses.

Phylogeny of the Enterobacteriaceae based on genes encoding elongation factor Tu and F-ATPase beta-subunit.

The phylogeny of enterobacterial species commonly found in clinical samples was analysed by comparing partial sequences of their elongation factor Tu gene (tuf) and of their F-ATPase beta-subunit gene (atpD). An 884 bp fragment for tuf and an 884 or 871 bp fragment for atpD were sequenced for 96 strains representing 78 species from 31 enterobacterial genera. The atpD sequence analysis exhibited an indel specific to Pantoea and Tatumella species, showing, for the first time, a tight phylogenetic affiliation between these two genera.

Modulation in aquaglyceroporin AQP1 gene transcript levels in drug-resistant Leishmania.

Antimonial-containing drugs are the first line of treatment against the parasite Leishmania. Resistance to antimonials has been correlated to its reduced accumulation. We used a dominant negative functional cloning strategy where a Leishmania mexicana expression cosmid bank was transfected in cells resistant to trivalent antimony (SbIII).

Microfluidic device for rapid (<15 min) automated microarray hybridization.

Background: Current hybridization protocols on microarrays are slow and need skilled personnel. Microfluidics is an emerging science that enables the processing of minute volumes of liquids to perform chemical, biochemical, or enzymatic analyzes. The merging of microfluidics and microarray technologies constitutes an elegant solution that will automate and speed up microarray hybridization.

Correlation between microarray DNA hybridization efficiency and the position of short capture probe on the target nucleic acid.

The hybridization behavior of small oligonucleotides arrayed on glass slides is currently unpredictable. In order to examine the hybridization efficiency of capture probes along target nucleic acid, 20-mer oligonucleotide probes were designed to hybridize at different distances from the 5' end of two overlapping 402- and 432-bp ermB products amplified from the target DNA. These probes were immobilized via their 5' end onto glass slides and hybridized with the two labeled products.

The cAMP-specific phosphodiesterase 4B mediates Abeta-induced microglial activation.

Microglial activation is a key player in the degenerative process that accompanies the deposition of amyloid-beta (Abeta) peptide into senile plaques in Alzheimer's disease (AD) patients. The goal of this study is to identify novel genes involved in microglial activation in response to Abeta peptide. Prompted by the fact that soluble Abeta(1-42) (sAbeta(1-42))-stimulated primary rat microglia produce more tumor necrosis factor-alpha (TNF-alpha) than fibrillar Abeta(1-42) (fAbeta(1-42))-stimulated microglia, we examined gene expression in these cells following stimulation using cDNA arrays.

Notch 2-positive progenitors with the intrinsic ability to give rise to pancreatic ductal cells.

Pancreatic adenocarcinomas display foci of duct-like structures that are positive for markers of pancreatic ductal cells. The development of these tumors is promoted by conditions leading to acinar-to-ductal metaplasia, a process by which acinar cells are replaced by ductal cells. Acinar-to-ductal metaplasia has recently been shown to proceed through intermediary cells expressing Nestin.

Half-life of the doubly magic r-process nucleus 78Ni.

Nuclei with magic numbers serve as important benchmarks in nuclear theory. In addition, neutron-rich nuclei play an important role in the astrophysical rapid neutron-capture process (r process). 78Ni is the only doubly magic nucleus that is also an important waiting point in the r process, and serves as a major bottleneck in the synthesis of heavier elements.

Role of the ABC transporter MRPA (PGPA) in antimony resistance in Leishmania infantum axenic and intracellular amastigotes.

Antimonial compounds are the mainstay for the treatment of infections with the protozoan parasite Leishmania. We present our studies on Leishmania infantum amastigote parasites selected for resistance to potassium antimonyl tartrate [Sb(III)]. Inside macrophages, the Sb(III)-selected cells are cross-resistant to sodium stibogluconate (Pentostam), the main drug used against Leishmania.

Egocentric search for disappearing objects in domestic dogs: evidence for a geometric hypothesis of direction.

In several species, the ability to locate a disappearing object is an adaptive component of predatory and social behaviour. In domestic dogs, spatial memory for hidden objects is primarily based on an egocentric frame of reference. We investigated the geometric components of egocentric spatial information used by domestic dogs to locate an object they saw move and disappear.

The heat shock protein HSP70 and heat shock cognate protein HSC70 contribute to antimony tolerance in the protozoan parasite leishmania.

Antimony-containing drugs are still the drugs of choice in the treatment of infections caused by the parasite Leishmania. Resistance to antimony is now common in some parts of the world, and several mechanisms of resistance have been described. By transfecting cosmid banks and selecting with potassium antimonyl tartrate (SbIII), we have isolated a cosmid associated with resistance.

Culture and immortalization of pancreatic ductal epithelial cells.

Some populations of the epithelial cells from the duct and ductular network of the mammalian pancreas have been isolated and maintained in vitro for up to 3 mo. These cells express many of the surface factors that are unique to them in vivo. They also retain significant drug- and carcinogen-metabolizing capacity in vitro.

Leishmaniasis: drugs in the clinic, resistance and new developments.

The control of Leishmania infections relies primarily on chemotherapy. The arsenal of drugs available for treating Leishmania infections is limited and includes pentavalent antimonials, pentamidine, amphotericin B, miltefosine, fluconazole and few other drugs at various stages of their development process. In this review, we will discuss the latest results regarding resistance mechanisms to drugs used in the clinic against Leishmania infections.

Growth phase regulation of the main folate transporter of Leishmania infantum and its role in methotrexate resistance.

The protozoan parasite Leishmania relies on the uptake of folate and pterin from the environment to meet its nutritional requirements. We show here that a novel gene (folate transporter 1 (FT1)) deleted in a Leishmania infantum methotrexate-resistant mutant corresponds to the main folate transporter (K(m), 410 nM). FT1 was established as the main folate transporter by both gene transfection and by targeted gene deletion.

Use of tuf sequences for genus-specific PCR detection and phylogenetic analysis of 28 streptococcal species.

A 761-bp portion of the tuf gene (encoding the elongation factor Tu) from 28 clinically relevant streptococcal species was obtained by sequencing amplicons generated using broad-range PCR primers. These tuf sequences were used to select Streptococcus-specific PCR primers and to perform phylogenetic analysis. The specificity of the PCR assay was verified using 102 different bacterial species, including the 28 streptococcal species.

Leishmania major LmACR2 is a pentavalent antimony reductase that confers sensitivity to the drug pentostam.

Arsenicals and antimonials are first line drugs for the treatment of trypanosomal and leishmanial diseases. To create the active form of the drug, Sb(V) must be reduced to Sb(III). Because arsenic and antimony are related metalloids, and arsenical resistant Leishmania strains are frequently cross-resistant to antimonials, we considered the possibility that Sb(V) is reduced by a leishmanial As(V) reductase.

Apoptosis induced by adenovirus-mediated p14ARF expression in U2OS osteosarcoma cells is associated with increased Fas expression.

The INK4A/ARF locus on chromosome 9 is a tumor suppressor gene frequently mutated in human cancers. In order to study the effects of p14ARF expression in tumor cells, we constructed a recombinant adenovirus containing p14ARF cDNA (Adp14ARF). Adp14ARF infection of U2OS osteosarcoma cells which has wild type p53 and mutant p14ARF revealed high levels of p14 (ARF) expression within 24h.

Differential protein expression analysis of Leishmania major reveals novel roles for methionine adenosyltransferase and S-adenosylmethionine in methotrexate resistance.

Leishmania is a trypanosomatid parasite causing serious disease and displaying resistance to various drugs. Here, we present comparative proteomic analyses of Leishmania major parasites that have been either shocked with or selected in vitro for high level resistance to the model antifolate drug methotrexate. Numerous differentially expressed proteins were identified by these experiments.

Drug uptake and modulation of drug resistance in Leishmania by an aquaglyceroporin.

Leishmaniasis is a protozoan parasitic disease that affects 12 million people worldwide. The first line choice for the treatment of this disease is antimonial drugs. In the endemic regions, resistance to this class of drugs is a major impediment to treatment.

New real-time PCR assay for rapid detection of methicillin-resistant Staphylococcus aureus directly from specimens containing a mixture of staphylococci.

Molecular methods for the rapid identification of methicillin-resistant Staphylococcus aureus (MRSA) are generally based on the detection of an S. aureus-specific gene target and the mecA gene. However, such methods cannot be applied for the direct detection of MRSA from nonsterile specimens such as nasal samples without the previous isolation, capture, or enrichment of MRSA because these samples often contain both coagulase-negative staphylococci (CoNS) and S.

High-intensity resistance training improves muscle strength, self-reported function, and disability in long-term stroke survivors.

Background And Purpose: To evaluate the efficacy of supervised high-intensity progressive resistance training (PRT) on lower extremity strength, function, and disability in older, long-term stroke survivors.

Methods: Forty-two volunteers aged 50 years and above, 6 months to 6 years after a single mild to moderate stroke, were randomized into either a control group of upper extremity stretching or a PRT group that received a 12-week supervised high-intensity resistance training program consisting of bilateral leg press (LP), unilateral paretic and nonparetic knee extension (KE), ankle dorsiflexion (DF), and plantarflexion (PF) exercises. Functional performance was assessed using the 6-minute walk, stair-climb time, repeated chair-rise time, and habitual and maximal gait velocities.