Early detection of leprosy by examination of household contacts, determination of serum anti-PGL-1 antibodies and consanguinity

A cross-sectional clinical trial in which the serum anti-phenolic glycolipid (anti-PGL-1) antibodies were analysed in household contacts (HHC) of patients with leprosy as an adjunct early leprosy diagnostic marker was conducted. The families of 83 patients underwent clinical examination and serum anti-PGL1 measurement using enzyme-linked immunosorbent assay. Of 320 HHC, 98 were contacts of lepromatous leprosy (LL), 80 were contacts of borderline lepromatous (BL), 28 were contacts of borderline (BB) leprosy, 54 were contacts of borderline tuberculoid (BT), 40 were contacts of tuberculoid (TT) and 20 were contacts of indeterminate (I) leprosy. Consanguinity with the patients was determined for 232 (72.5%) HHC. Of those 232 contacts, 183 had linear consanguinity. Forty-nine HHC had collateral consanguinity. Fifty-eight contacts (18.1%) tested positive for anti-PGL1 antibodies. The number of seropositive contacts based on the clinical forms of the index case was 17 (29.3%) for LL, 15 (25.9%) for BL, one (1.7%) for BB, 14 (24.1%) for BT, three (5.2%) for TT and eight (13.7%) for I. At the one year follow-up, two (3.4%) of these seropositive contacts had developed BT leprosy. The results of the present study indicate that the serum anti-PGL-1 IgM antibody may be useful for evaluating antigen exposure and as a tool for an early leprosy diagnosis in HHC.     

Recombinant antigen production for assays of intradermoreaction for diagnosis and surveillance of tuberculosis

The goal of the present work was to develop reagents with potential for tuberculosis diagnosis. Genetic sequences of Mycobacterium tuberculosis secretion antigens were amplified by PCR, cloned into the Gateway^® system, and expressed in Escherichia coli. The recombinant M. tuberculosis proteins were purified by metal affinity chromatography and preparative gel SDS-PAGE electrophoresis followed by electroelution and removal of endotoxins using Triton X-114. In total, seven recombinant proteins were obtained (ESAT-6, CFP10, TB10.3, TB10.4, MTSP11, MPT70, and MPT83). Delayed hypersensitivity reactions (DHR) was evaluated in Cavia porcellus and compared to the response using a standard purified protein derivative (PPD). All seven recombinant proteins produced a positive induration reaction in an intradermal test in guinea pigs previously sensitized with M. tuberculosis. When applied together, at a concentration of each recombinant protein 0.04 mg/mL, the intradermoreaction in C. porcellus was significantly higher than that obtained by standard PPD (p-value = 0.00386).     

Adsorption of cysteine on hematite,magnetite and ferrihydrite: FT-IR,Mössbauer,EPR spectroscopy and X-ray diffractometry studies

In the present paper, the adsorption of cysteine on hematite, magnetite and ferrihydrite was studied using FT-IR, electron paramagnetic resonance (EPR), Mössbauer spectroscopy and X-ray diffractometry. Cysteine was dissolved in artificial seawater (two different pHs) which contains the major constituents. There were two main findings described in this paper. First, after the cysteine adsorption, the FT-IR spectroscopy and X-ray diffractometry data showed the formation of cystine. Second, the Mössbauer spectroscopy did not show any increase in the amount of Fe²⁺ as expected due the oxidation of cysteine to cystine. An explanation could be that Fe²⁺ was oxidized by the oxygen present in the seawater or there occurred a reduction of cystine by Fe²⁺ generating cysteine and Fe³⁺. The specific surface area and pH at point of zero charge of the iron oxides were influenced by adsorption of cysteine. When compared to other iron oxides, ferrihydrite adsorbed significantly (p < 0.05) more cysteine. The pH has a significant (p < 0.05) effect only on cysteine adsorption on hematite. The FT-IR spectroscopy results showed that cystine remains adsorbed on the surface of the iron oxides even after being mixed with KCl and the amine and carboxylic groups are involved in this interaction. X-ray diffractometry showed no changes on iron oxides mineralogy and the following precipitated substances were found along with the iron oxides after drying the samples: cysteine, cystine and seawater salts. The EPR spectroscopy showed that cysteine interacts with iron oxides, changing the relative amounts of iron oxides and hydroxide.     

Epilithic biofilms provide large amounts of nitrogen to tropical mountain landscapes

We show that epilithic biofilms are a relevant nitrogen (N) source in a rocky mountain range in Brazil. During different seasons, we quantified nitrate, ammonium, dissolved organic N (DON) and total dissolved N (TDN) leached by a simulated short rain event. We quantified the epilithic autotrophic biomass by taxonomic groups and its correlation with leached N. We hypothesized that leached N would be correlated to heterocystous cyanobacteria biomass since they are more efficient N₂ fixers. We estimated a landscape N supply of 8.5 kg.ha⁻¹.year⁻¹ considering the mean precipitation in the region. TDN in leachate was mainly composed of DON (83.8% ± 22%), followed by nitrate (12.1% ± 3%) and ammonium (5% ± 5%). The autotrophic epilithic community was mainly composed of non-heterocystous (Gloeocapsopsis) and heterocystous cyanobacteria (Scytonema and Stigonema), except for a site more commonly affected by fire events that showed a dominance of Chlorophyta. Biogeochemical upscaling was facilitated by the fact that N leaching was not different among sites or related to autotrophic epilithic biomass or assemblage composition. In conclusion, the capacity of epilithic biofilms to provide N to surrounding systems is an ecosystem service that underscores the necessity to conserve them and their habitats.     

Structural and Topographic Dynamics of Pulmonary Histopathology and Local Cytokine Profiles in Paracoccidioides brasiliensis Conidia-Infected Mice

Background

Paracoccidioidomycosis (PCM), an endemic systemic mycosis caused by the fungus Paracoccidioides brasiliensis (Pb), usually results in severe lung damage in patients.

Methods and Findings

Considering the difficulties to sequentially study the infection in humans, this work was done in mice inoculated intranasally with infective Pb-conidia. Lungs of control and Pb-infected mice were studied after 2-hours, 4, 8, 12 and 16-weeks post-infection (p.i) in order to define histopathologic patterns of pulmonary lesions, multiplex-cytokine profiles and their dynamics during the course of this mycosis. Besides the nodular/granulomatous lesions previously informed, results revealed additional non-formerly described lung abnormalities, such as periarterial sheath inflammation and pseudotumoral masses. The following chronologic stages occurring during the course of the experimental infection were defined: Stage one (2-hours p.i): mild septal infiltration composed by neutrophils and macrophages accompanied by an intense “cytokine burst” represented by significant increases in IL-1α, IL-1β, IL-4, IL-5, IL-6, IL-10, IL12p70, IL-13, IL-17, Eotaxin, G-CSF, MCP1, MIP1α, GM-CSF, IFN-γ, MIP1β and TNFα levels. Stage two (4-weeks p.i): presence of nodules, evidence of incipient periarterial- and intense but disperse parenchymal- inflammation, abnormalities that continued to be accompanied by hyper-secretion of those cytokines and chemokines mentioned in the first stage of infection. Stages three and four (8 and 12-weeks p.i.): fungal proliferation, inflammation and collagenesis reached their highest intensity with particular involvement of the periarterial space. Paradoxically, lung cytokines and chemokines were down-regulated with significant decreases in IL-2,IL-3,IL-5,IL-9,IL-13,IL-15,GM-CSF,IFN-γ,MIP1β and TNFα. Stage five (16-weeks p.i.): inflammation decreased becoming limited to the pseudotumoral masses and was accompanied by a “silent” cytokine response, except for PDGF, MIG, RANTES and IL12p40 which remained up-regulated for the duration of the experiment.

Conclusions

Results of this study identified both classic and novel patterns corresponding to histopathologic and immunologic responses occurring during the course of experimental PCM.     

Electromyographic activity and rate of muscle fatigue of the quadriceps femoris during cycling exercise in the severe domain

This study compared the activation pattern and the fatigue rate among the superficial muscles of the quadriceps femoris (QF) during severe cycling exercise. Peak oxygen consumption (VO(2)peak) and maximal accumulated oxygen Deficit (MAOD) were established by 10 well-trained male cyclists (27.5 ± 4.1 years, 71.0 ± 10.3 kg, 173.4 ± 6.6 cm, mean VO(2)peak 56.7 ± 4.4 ml·kg·min(-1), mean MAOD 5.7 ± 1.1 L). Muscle activity (electromyographic [EMG] signals) was obtained during the supramaximal constant workload test (MAOD) and expressed by root mean square (RMS) and median frequency (MF slope). The RMS of the QF, vastus lateralis (VL) and vastus medialis (VM) muscles were significantly higher than at the beginning after 75% of exercise duration, whereas for the rectus femoris (RF), this was observed after 50% of exercise duration (p ≤ 0.05). The slope of the MF was significantly higher in the RF, followed by the VL and VM (-3.13 ± 0.52 vs. -2.61 ± 0.62 vs. -1.81 ±0.56, respectively; p < 0.05). We conclude that RF may play an important role in limiting performance during severe cycling exercise.     

The Aspergillus nidulans nucA(EndoG) homologue is not involved in cell death

Upon apoptosis induction, translocation of mammalian mitochondrial endonuclease G (EndoG) to the nucleus coincides with large-scale DNA fragmentation. Here, we describe for the first time a homologue of EndoG in filamentous fungi by investigating if the Aspergillus nidulans homologue of the EndoG gene, named nucA(EndoG), is being activated during farnesol-induced cell death. Our results suggest that NucA is not involved in cell death, but it plays a role in the DNA-damaging response in A. nidulans.     

Species–area models to assess biodiversity change in multi-habitat landscapes: The importance of species habitat affinity

Species–area relationships (SARs) are a common tool to assess the impacts of habitat loss on species diversity. Species–area models that include habitat effects may better describe biodiversity patterns; also the shape of the SAR may be best described by other models than the classical power model. We compared the fit of 24 SAR models, i.e. eight basic models using three approaches: (i) single-habitat models, (ii) multi-habitat models which account for the effect of the habitat composition on total species diversity (= choros models) and (iii) multi-habitat models which also account for the differential use of habitats by different species groups (= countryside models). We use plant diversity data from a multi-habitat landscape in NW Portugal. Countryside models had the best fit both when predicting species–area patterns of species groups and of total species richness. Overall, choros models had a better fit than single-habitat models. We also tested the application of multi-habitat models to land-use change scenarios. Estimates of species richness using the choros model only depended on the number of habitats in the landscape. In contrast, for the countryside model, estimates of species richness varied continuously with the relative proportion of the different habitat types in the landscape, and projections suggest that land-use change impacts may be moderated by a species’ ability to use multiple habitats in the landscape. We argue that the countryside SAR is a better model to assess the impacts of land-use changes than the single-habitat SAR or the choros model, as species often face habitat change instead of real habitat loss, and species response to change is contingent on their differential use of habitats in the landscape.