Palmitoylation of inducible nitric-oxide synthase at Cys-3 is required for proper intracellular traffic and nitric oxide synthesis

A number of cell types express inducible nitric-oxide synthase (NOS2) in response to exogenous insults such as bacterial lipopolysaccharide or proinflammatory cytokines. Although it has been known for some time that the N-terminal end of NOS2 suffers a post-translational modification, its exact identification has remained elusive. Using radioactive fatty acids, we show herein that NOS2 becomes thioacylated at Cys-3 with palmitic acid. Site-directed mutagenesis of this single residue results in the absence of the radiolabel incorporation. Acylation of NOS2 is completely indispensable for intracellular sorting and .NO synthesis. In fact, a C3S mutant of NOS2 is completely inactive and accumulates to intracellular membranes that almost totally co-localize with the Golgi marker beta-cop. Likewise, low concentrations of the palmitoylation blocking agents 2-Br-palmitate or 8-Br-palmitate severely affected the .NO synthesis of both NOS2 induced in muscular myotubes and transfected NOS2. However, unlike endothelial NOS, palmitoylation of inducible NOS is not involved in its targeting to caveolae. We have created 16 NOS2-GFP chimeras to inspect the effect of the neighboring residues of Cys-3 on the degree of palmitoylation. In this regard, the hydrophobic residue Pro-4 and the basic residue Lys-6 seem to be indispensable for palmitoylation. In addition, agents that block the endoplasmic reticulum to Golgi transit such as brefeldin A and monensin drastically reduced NOS2 activity leading to its accumulation in perinuclear areas. In summary, palmitoylation of NOS2 at Cys-3 is required for both its activity and proper intracellular localization.     

DNA damage in peripheral blood lymphocytes in patients during combined chemotherapy for breast cancer

Combined chemotherapy is used for the treatment of a number of malignancies such as breast cancer. The target of these antineoplastic agents is nuclear DNA, although it is not restricted to malignant cells. The aim of the present study was to assess DNA damage in peripheral blood lymphocytes (PBLs) of breast cancer patients subjected to combined adjuvant chemotherapy (5-fluorouracil, epirubicin and cyclophosphamide, FEC), using a modified comet assay to detect DNA single-strand breaks (SSB) and double-strand breaks (DSB).

Forty-one female patients with advanced breast cancer before and after chemotherapy and 60 healthy females participated in the study. Alkaline and neutral comet assays were performed in PBLs according to a standard protocol, and DNA tail moment was measured by a computer-based image analysis system.

Breast cancer patients before treatment had higher increased background levels of SSB and DSB as compared to healthy women. During treatment, a significant increase in DNA damage was observed after the 2nd cycle, which persisted until the end of treatment. Eighty days after the end of treatment the percentage of PBLs with SSB and DSB remained elevated, but the magnitude of DNA damage (tail moment) returned to baseline levels. There was no correlation between PBL DNA damage and response to chemotherapy.

DNA-SSB and DSB in PBLs are present in cancer patients before treatment and increase significantly after combined chemotherapy. No correlation with response to adjuvant chemotherapy was found. Biomonitoring DNA damage in PBLs of cancer patients could help prevent secondary effects and the potential risks of developing secondary cancers.     

Inotropic activity induced by carbamazepine-alkyne derivative in an isolated heart model and perfused to constant flow

Inotropic activity induced by carbamazepine-alkyne derivative in an isolated heart model and perfused to constant flow Introduction. Few data exist with respect to the effects of carbamazepine and its derivatives at cardiovascular level; furthermore, the molecular mechanisms and cellular site of action are still unclear. Objective. The effects induced by carbamazepine-alquine derivative on perfusion pressure, vascular resistance and left ventricular pressure were evaluated. Materials and methods. The effects of carbamazepine and carbamazepine-alquine on the perfusion pressure, vascular resistance and left ventricular pressure were examined in isolated rat hearts (Langendorff model). Results. Four results were obtained: (1) The carbamazepine-alquine derivative 10-9 mM increased the perfusion pressure and vascular resistance in comparison with the carbamazepine 10-9 mM; (2) the effect of carbamazepine-alquine derivative 10-9-10-4 mM on left ventricular pressure not was inhibited by metoprolol or prazosin at a dose of 10-6 mM; (3) nifedipine 10-6 mM blocked the effects exerted by the carbamazepine-alquine derivative 10-9-10--4 mM on left ventricular pressure, and (4) the carbamazepine-alquine derivative at dose of 10-9 mM increased the concentration of intracellular calcium over a time period of 3-18 min; nevertheless, in presence of nifedipine 10-6 mM this effect was inhibited significantly (p=0.005). Conclusions. The activity exerted by carbamazepine-alquine derivative on perfusion pressure, vascular resistance and left ventricular pressure involved activation of calcium channel type-L, brought indirectly changes in the intracellular calcium levels and subsequently induced a positive inotropic effect.     

Cognitive impairment and the risk of falling in the elderly

Risk of fall is significantly increased in old people with cognitive decline due to specific associations between gait parameters and cognition. This association has recently been demonstrated, there being increasing evidence that cognitive domains such as attention, executive function and types of memory are critical for the correct regulation of gait. Gait disturbances can appear as early predictors of dementia in elderly patients. In the assessment of the fall risk, the use of dual tasks is novel, simple and relevant, especially in cognitive decline. Evidence for interventions in this population is limited, with vitamin D and physical exercise being the most encouraging, for decreasing the risk of fall in dementia.     

Synthesis, characterization and antiproliferative studies of the enantiomers of cis-[(1,2-camphordiamine)dichloro]platinum(II) complexes

The platinum(II) complex cis-[(1S,2R,3S)-1,7,7-trimethylbicyclo[2.2.1]heptane-2,3-diamine]dichloroplatinum(II) (1) and its enantiomer (2) have been synthesized and physically and spectroscopically characterized. To obtain the enantiopure complexes the chiral pool approach was applied. The synthetic pathway has four steps, starting from (+/-)-diphenylethylenediamine (DPEDA) (3) and the natural products (1S)-camphorquinone or (1R)-camphorquinone to obtain enantiomers 1 and 2, respectively. The interaction of the Pt(II) complexes with DNA was studied by several techniques: circular dichroism, electrophoresis on agarose gel and atomic force microscopy (AFM). These studies showed differences in the degree of interaction between both enantiomers and DNA (calf thymus DNA and plasmid pBR322 DNA). The cytotoxicity of enantiomers 1 and 2 against the HL-60 cell line was studied by in vitro tests of antiproliferative activity, incubating during both 24 h and 72 h. An important difference of activity was found between both enantiomers regarding the IC50 data at 24 h of incubation. Thus, complex 1 showed to be much more active than its enantiomer 2.     

EAHFE – TROPICA2 study. Prognostic value of troponin in patients with acute heart failure treated in Spanish hospital emergency departments

Objective: Evaluate the use of different cardiac troponin (cTn) immunoassays and the prognostic value of increased cTn values in patients diagnosed with acute heart failure (AHF) in the emergency department (ED).

Method: The epidemiology acute heart failure emergency-TROPonin in acute heart failure2 (EAHFE-TROPICA2) is a retrospective study including patients with AHF admitted in 34 Spanish EDs with cTn values determined in the ED. We studied the prevalence of elevated troponin (value above the established reference limit) for the different types of troponin. We also assessed crude and adjusted primary (1-year all-cause death) and secondary (30 d ED revisit due to AHF) outcomes for every type of cTn and different magnitudes of troponin elevation.

Results: We analysed 4705 episodes of AHF. Troponin was elevated in 48.4% of the cases (25.3% in cTnI, 37.9% in cTnT and 82.2% in hs-cTnT). Mortality at one year was higher in patients with elevated troponin (adjusted HR 1.61; CI 95% 1.38–1.88) regardless of the type of cTn determined. Elevated troponin was not related to ED revisit within 30 d after discharge (1.01; 0.87–1.19).

Conclusions: The use of conventional troponin in the ED is useful to predict one-year mortality in patients with AHF. Highly sensitive cTnT (hs-cTnT) elevations less than double the reference value have no impact on patient outcome.     

Differentiation of Human Umbilical Cord Matrix Mesenchymal Stem Cells into Neural-Like Progenitor Cells and Maturation into an Oligodendroglial-Like Lineage

Mesenchymal stem cells (MSCs) are viewed as safe, readily available and promising adult stem cells, which are currently used in several clinical trials. Additionally, their soluble-factor secretion and multi-lineage differentiation capacities place MSCs in the forefront of stem cell types with expected near-future clinical applications. In the present work MSCs were isolated from the umbilical cord matrix (Wharton''s jelly) of human umbilical cord samples. The cells were thoroughly characterized and confirmed as bona-fide MSCs, presenting in vitro low generation time, high proliferative and colony-forming unit-fibroblast (CFU-F) capacity, typical MSC immunophenotype and osteogenic, chondrogenic and adipogenic differentiation capacity. The cells were additionally subjected to an oligodendroglial-oriented step-wise differentiation protocol in order to test their neural- and oligodendroglial-like differentiation capacity. The results confirmed the neural-like plasticity of MSCs, and suggested that the cells presented an oligodendroglial-like phenotype throughout the differentiation protocol, in several aspects sharing characteristics common to those of bona-fide oligodendrocyte precursor cells and differentiated oligodendrocytes.     

Learning Probabilistic Features for Robotic Navigation Using Laser Sensors

SLAM is a popular task used by robots and autonomous vehicles to build a map of an unknown environment and, at the same time, to determine their location within the map. This paper describes a SLAM-based, probabilistic robotic system able to learn the essential features of different parts of its environment. Some previous SLAM implementations had computational complexities ranging from O(Nlog(N)) to O(N²), where N is the number of map features. Unlike these methods, our approach reduces the computational complexity to O(N) by using a model to fuse the information from the sensors after applying the Bayesian paradigm. Once the training process is completed, the robot identifies and locates those areas that potentially match the sections that have been previously learned. After the training, the robot navigates and extracts a three-dimensional map of the environment using a single laser sensor. Thus, it perceives different sections of its world. In addition, in order to make our system able to be used in a low-cost robot, low-complexity algorithms that can be easily implemented on embedded processors or microcontrollers are used.