Mutation of critical residues reveals insights of yellow fever virus nonstructural protein 1 (NS1) stability and its formation

Communicated by Ramaswamy H. Sarma     

Characterization and expression analysis of P5CS (Δ1-pyrroline-5-carboxylate synthase) gene in two distinct populations of the Atlantic Forest native species Eugenia uniflora L.

Molecular Biology Reports - Eugenia uniflora is an Atlantic Forest native species, occurring in contrasting edaphoclimatic environments. The identification of genes involved in response to abiotic...     

Molecular Identification of Candida Species in the Oral Microbiota of Individuals with Down Syndrome: A Case–Control Study

Mycopathologia - Candida species are common in the human oral microbiota and may cause oral candidiasis (OC) when the microbiota equilibrium is disturbed. Immunosuppressed individuals are...     

High temporal and individual variation in the prevalence and intensity of chytrid infection in the southernmost Leaf Frog of the genus Pithecopus (Anura,Phyllomedusidae)

Hydrobiologia - Pithecopus rusticus is an endemic amphibian restricted to the type locality, in southern Brazil, and possibly endangered to extinction, due to habitat degradation. However, an...     

In Vitro Evaluation of the Effect of Stimulation with Magnetic Fields on Chondrocytes

Magnetic fields (MFs) have been used as an external stimulus to increase cell proliferation in chondrocytes and extracellular matrix (ECM) synthesis of articular cartilage. However, previously published studies have not shown that MFs are homogeneous through cell culture systems. In addition, variables such as stimulation times and MF intensities have not been standardized to obtain the best cellular proliferative rate or an increase in molecular synthesis of ECM. In this work, a stimulation device, which produces homogeneous MFs to stimulate cell culture surfaces was designed and manufactured using a computational model. Furthermore, an in vitro culture of primary rat chondrocytes was established and stimulated with two MF schemes to measure both proliferation and ECM synthesis. The best proliferation rate was obtained with an MF of 2 mT applied for 3 h, every 6 h for 8 days. In addition, the increase in the synthesis of glycosaminoglycans was statistically significant when cells were stimulated with an MF of 2 mT applied for 5 h, every 6 h for 8 days. These findings suggest that a stimulation with MFs is a promising tool that could be used to improve in vitro treatments such as autologous chondrocyte implantation, either to increase cell proliferation or stimulate molecular synthesis. Bioelectromagnetics. 2020;41:41–51 © 2019 Bioelectromagnetics Society     

The novel NhaE-type Na+/H+ antiporter of the pathogenic bacterium Neisseria meningitidis

Neisseria meningitidis is a pathogenic bacterium responsible for meningitis. The mechanisms underlying the control of Na⁺ transmembrane movement, presumably important to pathogenicity, have been barely addressed. To elucidate the function of the components of the Na⁺ transport system in N. meningitidis, an open reading frame from the genome of this bacterium displaying similarity with the NhaE type of Na⁺/H⁺ antiporters was expressed in Escherichia coli and characterized for sodium transport ability. The N. meningitidis antiporter (NmNhaE) was able to complement an E. coli strain devoid of Na⁺/H⁺ antiporters (KNabc) respecting the ability to grow in the presence of NaCl and LiCl. Ion transport assays in everted vesicles prepared from KNabc expressing NmNhaE from a plasmid confirmed its ability to translocate Na⁺ and Li⁺. Here is presented the characterization of the first NhaE from a pathogen, an important contribution to the comprehension of sodium ion metabolism in this kind of microorganisms.     

Different assembly of acid and salt tolerance response in two dairy Listeria monocytogenes wild strains

A lack on the association between acid tolerance response (ATR) and osmotolerance response (OTR) among Listeria monocytogenes dairy isolates was found. In order to evaluate how wild L. monocytogenes isolates mount tolerance responses under a sub-lethal pH and a low sodium chloride concentration (pH 5.5 and 3.5 % [w/v] NaCl), a proteomic approach was used. The ATR and OTR of two L. monocytogenes cheese dairy isolates (strain T8, serotype 4b and A9, serotype 1/2b or 3b) were determined. The proteomes of the adapted and non-adapted cultures were evaluated by 2-DE. One strain displayed an ATR, but not an OTR and the other displayed an OTR, but not an ATR. The ATR positive strain showed the over-production of proteins related with protein synthesis, protein folding, attainment of reduction power, ribose production and cell wall. In contrast, in the OTR-positive-strain proteins related with glycolysis, general stress and detoxification were identified.     

Effect of Acute Administration of l-Tyrosine on Oxidative Stress Parameters in Brain of Young Rats

Tyrosinemia type II, also known as Richner–Hanhart syndrome, is an autosomal recessive inborn error of metabolism caused by a deficiency of hepatic cytosolic tyrosine aminotransferase, and is associated with neurologic and development difficulties in numerous patients. Considering that the mechanisms underlying the neurological dysfunction in hypertyrosinemic patients are poorly known and that studies demonstrated that high concentrations of tyrosine provoke oxidative stress in vitro and in vivo in the cerebral cortex of rats, in the present study we investigate the oxidative stress parameters (enzymatic antioxidant defenses, thiobarbituric acid-reactive substances and protein carbonyl content) in cerebellum, hippocampus and striatum of 30-old-day rats after acute administration of l-tyrosine. Our results demonstrated that the acute administration of l-tyrosine increased the thiobarbituric acid reactive species levels in hippocampus and the carbonyl levels in cerebellum, hippocampus and striatum. In addition, acute administration of l-tyrosine significantly decreased superoxide dismutase activity in cerebellum, hippocampus and striatum, while catalase was increased in striatum. In conclusion, the oxidative stress may contribute, along with other mechanisms, to the neurological dysfunction characteristic of hypertyrosinemia and the administration of antioxidants may be considered as a potential adjuvant therapy for tyrosinemia, especially type II.