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91.
Gabriel Capella Machado Daniela Vanessa Moris Thales Domingos Arantes Luciane Regina Franciscone Silva Raquel Cordeiro Theodoro Rinaldo P?ncio Mendes Adriana Pardini Vicentini Eduardo Bagagli 《Memórias do Instituto Oswaldo Cruz》2013,108(5):637-643
We aimed to evaluate whether the occurrence of cryptic species of
Paracoccidioides brasiliensis, S1, PS2, PS3 and
Paracoccidioides lutzii, has implications in the
immunodiagnosis of paracoccidioidomycosis (PCM). Small quantities of the antigen
gp43 were found in culture filtrates of P. lutzii strains and
this molecule appeared to be more variable within P. lutzii
because the synonymous-nonsynonymous mutation rate was lower, indicating an
evolutionary process different from that of the remaining genotypes. The
production of gp43 also varied between isolates belonging to the same species,
indicating that speciation events are important, but not sufficient to fully
explain the diversity in the production of this antigen. The culture filtrate
antigen AgEpm83, which was obtained from a PS3 isolate, showed large quantities
of gp43 and reactivity by immunodiffusion assays, similar to the standard
antigen (AgB-339) from an S1 isolate. Furthermore, AgEpm83 was capable of
serologically differentiating five serum samples from patients from the Botucatu
and Jundiaí regions. These patients had confirmed PCM but, were non-reactive to
the standard antigen, thus demonstrating an alternative for serological
diagnosis in regions in which S1 and PS2 occur. We also emphasise that it is not
advisable to use a single antigen preparation to diagnose PCM, a disease that is
caused by highly diverse pathogens. 相似文献
92.
Fernanda Augusta de Lima Barbosa Guterres Glaucia Regina MartinezMaria Eliane Merlin Rocha Sheila Maria Brochado Winnischofer 《Experimental cell research》2013
Recent studies demonstrated that simvastatin has antitumor properties in several types of cancer cells, mainly by inducing apoptosis and inhibiting growth. The arrest of proliferation is a feature of cellular senescence; however, the occurrence of senescence in melanoma cells upon simvastatin treatment has not been investigated until now. Our results demonstrated that exposure of human metastatic melanoma cells (WM9) to simvastatin induces a senescent phenotype, characterized by G1 arrest, positive staining for senescence-associated β-galactosidase assay, and morphological changes. Also, the main pathways leading to cell senescence were examined in simvastatin-treated human melanoma cells, and the expression levels of phospho-p53 and p21 were upregulated by simvastatin, suggesting that cell cycle regulators and DNA damage pathways are involved in the onset of senescence. Since simvastatin can act as a pro-oxidant agent, and oxidative stress may be related to senescence, we measured the intracellular ROS levels in WM9 cells upon simvastatin treatment. Interestingly, we found an increased amount of intracellular ROS in these cells, which was accompanied by elevated expression of catalase and peroxiredoxin-1. Collectively, our results demonstrated that simvastatin can induce senescence in human melanoma cells by activation of p53/p21 pathway, and that oxidative stress may be related to this process. 相似文献
93.
Camila Arantes Hartmann Vilma Regina Martins Flavia Regina Souza Lima 《FEBS letters》2013,587(2):238-244
Prion protein (PrPC) has neuroprotective functions and herein we demonstrate that astrocytes from PrPC-over-expressing mice are more resistant to induced cell death than wild-type astrocytes. The Stress-Inducible-Protein 1 (STI1), a PrPC ligand, prevents cell death in both wild-type and PrPC-over-expressing astrocytes through the activation of protein-kinase-A. Cultured embryonic astrocytes and brain extracts from PrPC-over-expressing mice show higher glial fibrillary acidic protein expression and reduced vimentin and nestin levels when compared to wild-type astrocytes, suggesting faster astrocyte maturation in the former mice. Our data indicate that PrPC levels modulate astrocyte development, and that PrPC–STI1 interaction contributes to protect against astrocyte death. 相似文献
94.
Ryan M. Burrows Jason B. Fellman Regina H. Magierowski Leon A. Barmuta 《Hydrobiologia》2013,703(1):1-14
Clearfell, burn and sow (CBS) forestry can potentially alter stream environments by increasing available light and the input of woody debris. However, little is known about how CBS forestry affects in-stream processes such as nutrient uptake. We evaluate whether short-term (2–7 years) environmental changes (e.g. light availability and woody debris) associated with CBS forestry lead to differences in nutrient uptake metrics. To do this, we measured in-stream uptake of soluble reactive phosphorus (SRP) and ammonium (NH4) in three old growth (OG) and four CBS-affected headwater stream reaches. The abundance of fine woody debris and light availability were significantly greater in CBS-affected than in OG reaches. Uptake velocities varied from 0.0880 to 0.951 mm min?1 for NH4 and from 0.0383 to 1.06 mm min?1 for SRP across all sites. The mean uptake of SRP, but not NH4, was significantly greater (i.e. higher uptake velocities and lower uptake lengths) in CBS-affected than in OG reaches. These results suggest that CBS forestry altered the stream environment enabling greater SRP uptake relative to OG reaches. Our findings highlight the tight linkage between headwater streams and their surrounding terrestrial environment, which has direct implications for catchment-scale biogeochemical processes. 相似文献
95.
96.
Maricy Raquel Lindenbah Bonfá Matthew James Grossman Francine Piubeli Encarnación Mellado Lucia Regina Durrant 《Biodegradation》2013,24(5):699-709
Phenol is a toxic aromatic compound used or produced in many industries and as a result a common component of industrial wastewaters. Phenol containing waste streams are frequently hypersaline and therefore require halophilic microorganisms for efficient biotreatment without dilution. In this study three halophilic bacteria isolated from different saline environments and identified as Halomonas organivorans, Arhodomonas aquaeolei and Modicisalibacter tunisiensis were shown to be able to grow on phenol in hypersaline media containing 100 g/L of total salts at a concentration of 3 mM (280 mg/L), well above the concentration found in most waste streams. Genes encoding the aromatic dioxygenase enzymes catechol 1,2 dioxygenase and protocatechuate 3,4-dioxygenase were present in all strains as determined by PCR amplification using primers specific for highly conserved regions of the genes. The gene for protocatechuate 3,4-dioxygenase was cloned from the isolated H. organivorans and the translated protein was evaluated by comparative protein sequence analysis with protocatechuate 3,4-dioxygenase proteins from other microorganisms. Although the analysis revealed a wide range of sequence divergence among the protocatechuate 3,4-dioxygenase family, all of the conserved domain amino acid structures identified for this enzyme family are identical or conservatively substituted in the H. organivorans enzyme. 相似文献
97.
Carlos Alberto Pires Pereira Alexandre R. Marra Luis Fernando Aranha Camargo Ant?nio Carlos Campos Pignatari Teresa Sukiennik Paulo Renato Petersen Behar Eduardo Alexandrino Servolo Medeiros Julival Ribeiro Evelyne Gir?o Luci Correa Carla Guerra Irna Carneiro Carlos Brites Marise Reis Marta Antunes de Souza Regina Tranchesi Cristina U. Barata Michael B. Edmond Brazilian SCOPE Study Group 《PloS one》2013,8(7)
Background
Nosocomial bloodstream infections (nBSIs) are an important cause of morbidity and mortality and are the most frequent type of nosocomial infection in pediatric patients.Methods
We identified the predominant pathogens and antimicrobial susceptibilities of nosocomial bloodstream isolates in pediatric patients (≤16 years of age) in the Brazilian Prospective Surveillance for nBSIs at 16 hospitals from 12 June 2007 to 31 March 2010 (Br SCOPE project).Results
In our study a total of 2,563 cases of nBSI were reported by hospitals participating in the Br SCOPE project. Among these, 342 clinically significant episodes of BSI were identified in pediatric patients (≤16 years of age). Ninety-six percent of BSIs were monomicrobial. Gram-negative organisms caused 49.0% of these BSIs, Gram-positive organisms caused 42.6%, and fungi caused 8.4%. The most common pathogens were Coagulase-negative staphylococci (CoNS) (21.3%), Klebsiella spp. (15.7%), Staphylococcus aureus (10.6%), and Acinetobacter spp. (9.2%). The crude mortality was 21.6% (74 of 342). Forty-five percent of nBSIs occurred in a pediatric or neonatal intensive-care unit (ICU). The most frequent underlying conditions were malignancy, in 95 patients (27.8%). Among the potential factors predisposing patients to BSI, central venous catheters were the most frequent (66.4%). Methicillin resistance was detected in 37 S. aureus isolates (27.1%). Of the Klebsiella spp. isolates, 43.2% were resistant to ceftriaxone. Of the Acinetobacter spp. and Pseudomonas aeruginosa isolates, 42.9% and 21.4%, respectively, were resistant to imipenem.Conclusions
In our multicenter study, we found a high mortality and a large proportion of gram-negative bacilli with elevated levels of resistance in pediatric patients. 相似文献98.
Joshua P. Vogel Maria Regina Torloni Armando Seuc Ana Pilar Betrán Mariana Widmer Jo?o Paulo Souza Mario Merialdi 《PloS one》2013,8(8)
Background
Twin pregnancies in low- and middle-income countries (LMICs) pose a high risk to mothers and newborns due to inherent biological risks and scarcity of health resources. We conducted a secondary analysis of the WHO Global Survey dataset to analyze maternal and perinatal outcomes in twin pregnancies and factors associated with perinatal morbidity and mortality in twins.Methods
We examined maternal and neonatal characteristics in twin deliveries in 23 LMICs and conducted multi-level logistic regression to determine the association between twins and adverse maternal and perinatal outcomes.Results
279,425 mothers gave birth to 276,187 (98.8%) singletons and 6,476 (1.2%) twins. Odds of severe adverse maternal outcomes (death, blood transfusion, ICU admission or hysterectomy) (AOR 1.85, 95% CI 1.60–2.14) and perinatal mortality (AOR 2.46, 95% CI 1.40–4.35) in twin pregnancies were higher, however early neonatal death (AOR 2.50, 95% CI 0.95–6.62) and stillbirth (AOR 1.22, 95% CI 0.58–2.57) did not reach significance. Amongst twins alone, maternal age <18, poor education and antenatal care, nulliparity, vaginal bleeding, non-cephalic presentations, birth weight discordance >15%, born second, preterm birth and low birthweight were associated with perinatal mortality. Marriage and caesarean section were protective.Conclusions
Twin pregnancy is a significant risk factor for maternal and perinatal morbidity and mortality in low-resource settings; maternal risk and access to safe caesarean section may determine safest mode of delivery in LMICs. Improving obstetric care in twin pregnancies, particularly timely access to safe caesarean section, is required to reduce risk to mother and baby. 相似文献99.
Regina Vyšniauskienė Vida Rančelienė Jolanta Patamsytė Donatas Žvingila 《Central European Journal of Biology》2013,8(5):480-491
Alfalfa (Medicago sativa; =M. sativa ssp. sativa) in Lithuania is sown as albuminous forage for cattle due to favourable climatic condition. Over many generations, alfalfa plants have escaped from cultivation fields into natural ecosystems and established wild populations. We collected and analyzed individuals from seventeen wild populations of M. sativa. Using random amplified polymorphic DNA (RAPD) and inter-simple sequence repeat (ISSR) analyses, 117 RAPD and 64 ISSR reproducible and highly polymorphic (90.8% for RAPD and 86.3% for ISSR) loci were established. AMOVA showed a high genetic differentiation of M. sativa populations for both types of DNA markers utilized. According to RAPD markers, the genetic variability among populations was 63.1% and 57.0% when ISSR markers were used. Taken together, these results demonstrate that wild populations of M. sativa possess a high potential of genetic variability, that could potentially result in colonization of natural ecosystems. The UPGMA cluster analysis also showed that the DNA markers discovered in this study can distinguish between M. sativa and M. falcata (=M. sativa ssp. falcata) populations and therefore may be used to study the genetic impact of M. sativa on the native populations of M. falcata. 相似文献
100.