Anti-N-methyl-d-aspartate receptor encephalitis in a pre-teenage girl: a case report

Anti-N-methyl-d-aspartate receptor (anti-NMDAR) encephalitis is an auto-immune and paraneoplastic encephalitis which generally affects young adults. It is a multistage illness, with prominent extrapyramidal, neuropsychiatric and autonomic symptoms. The syndrome is frequently associated with an ovarian teratoma. Recently, it has become evident that anti-NMDAR encephalitis is more common in children and adolescents than was previously believed. Prognostic factors that determine a good outcome are presence of a tumour, prompt treatment and no need for admission to an intensive care unit. Increased awareness among paediatricians of this potentially life-threatening disease is important because early recognition and treatment will improve the patients’ chances of a good clinical outcome. In this case report, we describe a 9-year-old girl with behavioural changes and severe extrapyramidal symptoms due to anti-NMDAR encephalitis associated with an ovarian teratoma. She was treated with a variety of immunomodulating therapies and made a slow, but good recovery.     

Progress in understanding oral health and HIV/AIDS

Over the last 30 years, there have been significant advances in our scientific knowledge of HIV disease, including prevention, detection, medical management, and attempts at cure. Investigations and observations of the oral cavity in individuals with HIV disease have contributed substantially to scientific discovery and innovation. Challenges remain for managing existing and emerging oral diseases associated with HIV and understanding the contribution of latent oral mucosal reservoirs to HIV eradication.     

Establishment of tissue-specific tolerance is driven by regulatory T cells selected by thymic epithelium

Grafts of thymic epithelium (TE) rudiments restore T cell development and function in allogeneic athymic mice. These TE chimeras are specifically tolerant to grafts of peripheral tissues (e.g. skin and heart) from the TE donor strain, although they harbor peripheral immunocompetent T cells capable of rejecting those grafts. Initial analysis has shown that TE chimeras also harbor TE-selected CD4 T lymphocytes that inhibit graft rejection by tissue-reactive T cells in immunocompetent recipients. Peripheral tolerance in TE chimeras is thus maintained by dominant mechanisms dependent on regulatory CD4 T lymphocytes. Here we show that TE-selected regulatory T cells recruit nontolerant tissue-reactive CD4 and CD8 T cells to express similar regulatory functions. Only recent thymic emigrants, but not peripheral resident mature T cells are susceptible to this process of functional education, which also requires exposure to specific antigens and occurs entirely in the periphery. We propose that these mechanisms play a major role in establishing and maintaining natural self tolerance to tissue-specific antigens.     

Correction to: Features of intracranial hemorrhage in cerebral venous thrombosis

Journal of Neurology - The original version of this article unfortunately contained mistakes. The correct information is given below.     

Simulations reveal that antimicrobial BP100 induces local membrane thinning,slows lipid dynamics and favors water penetration

BP100, a short antimicrobial peptide, produces membrane perturbations that depend on lipid structure and charge, salts presence, and peptide/lipid molar ratios. As membrane perturbation mechanisms are not fully understood, the atomic scale nature of peptide/membrane interactions requires a close-up view analysis. Molecular Dynamics (MD) simulations are valuable tools for describing molecular interactions at the atomic level. Here, we use MD simulations to investigate alterations in membrane properties consequent to BP100 binding to zwitterionic and anionic model membranes. We focused on membrane property changes upon peptide binding, namely membrane thickness, order parameters, surface curvature, lipid lateral diffusion and membrane hydration. In agreement with experimental results, our simulations showed that, when buried into the membrane, BP100 causes a decrease in lipid lateral diffusion and lipid acyl-chain order parameters and sharp local membrane thinning. These effects were most pronounced on the closest lipids in direct contact with the membrane-bound peptide. In DPPG and anionic-aggregate-containing DPPC/DPPG membranes, peptide flip (rotation of its non-polar facet towards the membrane interior) induced marked negative membrane curvature and enhanced the water residence half-life time in the lipid hydrophobic core and transmembrane water transport in the direction of the peptide. These results further elucidate the consequences of the initial interaction of cationic alpha-helical antimicrobial peptides with membranes.

MD simulations reveal that BP100 peptide induces local membrane thinning and negative curvature, slows lipid dynamics and increases the water life time in the lipid hydrophobic core and transmembrane water transport in the direction of the peptide.     

Is the body fat of the lizard Tupinambis merianae effective against bacterial infections?

Aim of the study

Tupinambis merianae is one of the animals that is most frequently used for medicinal purposes in Brazil as its body fat has many therapeutic indications in local folk medicine. This work presents the chemical compositions of the body fat of Tupinambis merianae and evaluates the antibacterial activity of the body fat as well as the ecological implications of its use in traditional medicine.

Materials and methods

Oil (OTM) was extracted from body fat located in the ventral region of Tupinambis merianae using hexane as a solvent. Fatty acids were determined indirectly using their corresponding methyl esters. The antibacterial activity of OTM was tested against standard as well as multi-resistant lines of Escherichia coli and Staphylococcus aureus, either alone or in combination with antibiotics and UV-A light.

Results

Body fat of Tupinambis merianae presents 57% and 43% of unsaturated and saturated fatty acids respectively. Our results indicated that OTM did not demonstrate relevant antibacterial activity against any of the lines of Escherichia coli or Staphylococcus aureus, nor when combined with antibiotics or with UV-A light.

Conclusions

In light of these results, we recommend (i) development of management plans for a sustainable and rational use of Tupinambis merianae reducing the possible pressure on this species; and (ii) more studies be focused on the use of OTM and other natural products derived from animals that are used to treat other illnesses.