Different response to antiepileptic drugs according to the type of epileptic events in a neonatal ischemia-reperfusion model.

Perinatal arterial stroke is the most frequent form of cerebral infarction in children. Neonatal seizures are the most frequent symptom during the neonatal period. The current management of perinatal stroke is based on supportive care.

An evolutionarily significant unicellular strategy in response to starvation in Dictyostelium social amoebae.

The social amoeba Dictyostelium discoideum is widely studied for its multicellular development program as a response to starvation. Aggregates of up to 10 (6) cells form fruiting bodies containing (i) dormant spores (~80%) that can persist for months in the absence of nutrients, and (ii) dead stalk cells (~20%) that promote the dispersion of the spores towards nutrient-rich areas. It is often overlooked that not all cells aggregate upon starvation.

Ceramides and sphingomyelinases in senile plaques.

The senile plaque is a hallmark lesion of Alzheimer disease (AD). We compared, without a priori, the lipidome of the senile plaques and of the adjacent plaque-free neuropil. The analysis by liquid chromatography coupled with electrospray ionization mass spectrometry revealed that laser microdissected senile plaques were enriched in saturated ceramides Cer(d18:1/18:0) and Cer(d18:1/20:0) by 33 and 78% respectively with respect to the surrounding neuropil.

Sildenafil mediates blood-flow redistribution and neuroprotection after neonatal hypoxia-ischemia.

Background And Purpose: The best conceivable treatment for hypoxia-ischemia (HI) is the restoration of blood flow to the hypoxic-ischemic region(s). Our objective was to examine whether boosting NO-cGMP signaling using sildenafil citrate, a phosphodiesterase-type 5 inhibitor, could modify cerebral blood flow and reduce lesions in the developing brain.

Methods: HI was induced in P7 Sprague-Dawley rats by unilateral carotid artery occlusion and hypoxia, and followed by either PBS or sildenafil.

Clinical deterioration following middle cerebral artery hemodynamic changes after intravenous thrombolysis for acute ischemic stroke.

Background: Little information exists regarding what occurs in the affected artery in the days after acute ischemic stroke and its impact in the outcome. We sought to determine the hemodynamic evolution and correlated this evoution with clinical outcome in stroke patients treated with intravenous thrombolysis.

Methods: Using serial transcranial Doppler ultrasound (TCD) on days 1 (TCD1), 3 to 6 (TCD2), and 7 to 10 (TCD3) after stroke, we determined the hemodynamics in the affected artery by means of the thrombolysis in brain ischemia (TIBI) score and compared this with clinical outcome (National Institutes of Health Stroke Scale [NIHSS] score) and functional outcome (modified Rankin Scale score) at discharge and at 3 months.

A potential role of chondroitin sulfate on bone in osteoarthritis: inhibition of prostaglandin E₂ and matrix metalloproteinases synthesis in interleukin-1β-stimulated osteoblasts.

Objectives: To determine the effect of chondroitin sulfate (CS) on inflammatory mediators and proteolytic enzymes induced by interleukin-1β (IL-1β) and related to cartilage catabolism in murine osteoblasts.

Design: Osteoblasts were obtained by enzymatic digestion of calvaria from Swiss mice and cultured for 3 weeks as a primary culture. Cells were then stimulated with IL-1β (1 or 10 ng/ml).

Concordance rates of Doppler ultrasound and CT angiography in the grading of carotid artery stenosis: a systematic literature review.

Physicians have been increasingly relying on noninvasive imaging methods to grade carotid stenosis. The accuracy of Doppler ultrasound (DUS) and CT angiography (CTA) versus intra-arterial angiography (IA) has been assessed in many studies and at least two meta-analyses. Here, we performed a systematic review of studies that compared DUS to CTA.

The hemodynamic status within 24 h after intravenous thrombolysis predicts infarct growth in acute ischemic stroke.

A rapid and complete recanalization of the occluded artery is the ideal goal when intravenous (IV) recombinant tissue plasminogen activator (rt-PA) is administrated to patients with acute ischemic stroke, i.e., limiting the ongoing ischemia to achieve a better outcome.

Combining contemporary and ancient DNA in population genetic and phylogeographical studies.

The analysis of ancient DNA in a population genetic or phylogeographical framework is an emerging field, as traditional analytical tools were largely developed for the purpose of analysing data sampled from a single time point. Markov chain Monte Carlo approaches have been successfully developed for the analysis of heterochronous sequence data from closed panmictic populations. However, attributing genetic differences between temporal samples to mutational events between time points requires the consideration of other factors that may also result in genetic differentiation.

From grazing resistance to pathogenesis: the coincidental evolution of virulence factors.

To many pathogenic bacteria, human hosts are an evolutionary dead end. This begs the question what evolutionary forces have shaped their virulence traits. Why are these bacteria so virulent? The coincidental evolution hypothesis suggests that such virulence factors result from adaptation to other ecological niches.

Detection of paroxysmal atrial fibrillation with transtelephonic EKG in TIA or stroke patients.

Background: Paroxysmal atrial fibrillation (PAF) may remain underdiagnosed after stroke, as suggested by long-duration EKG monitoring. Here we report the sensitivity of transtelephonic EKG monitoring (TTM) for detection of PAF in patients following a recent stroke or TIA and a negative 24-hour Holter.

Methods: We analyzed data from 98 consecutive patients with TTM and noncardioembolic TOAST stroke (n = 78) or TIA (n = 20).

Microembolic signals in systemic lupus erythematosus and other cerebral small vessel diseases.

Microembolic signals (MES) are detected by transcranial Doppler (TCD), and are mainly observed in cardiac and large-artery diseases; however they might also be observed in conditions affecting small vessels of the brain. We aimed to review the current medical literature related to MES assessed by TCD in patients with cerebral small vessel disease. We conducted a systematic review in PubMed and selected the articles with information on this topic.

Single-layered chrysotile nanotubes: A quantum mechanical ab initio simulation.

Chrysotile single-layered nanotubes, obtained by wrapping the Mg(3)Si(2)O(5)(OH)(4) lizardite monolayer along the (n,-n) hexagonal lattice vector, are simulated at the ab initio level by using an all electron 6-31G( *) basis set and the B3LYP functional for n varying from 14 to 24 (the nanotube radius R referred to the oxygen connecting the Mg and Si layers increases from 20 to 35 A). Because of the full exploitation of the helical symmetry, recently implemented in the CRYSTAL code, the computational cost for the full self-consistent field (SCF) and gradient calculation increases only by a factor of 2 and 1.2, respectively, when passing from the lizardite monolayer [18 atoms and 236 AOs (atomic orbitals) in the unit cell] to the (24, -24) tube (864 atoms and 11,328 AOs).

Stigmasterol: a phytosterol with potential anti-osteoarthritic properties.

Objective: Although most studies have focused on the cholesterol-lowering activity of stigmasterol, other bioactivities have been ascribed to this plant sterol compound, one of which is a potential anti-inflammatory effect. To investigate the effects of stigmasterol, a plant sterol, on the inflammatory mediators and metalloproteinases produced by chondrocytes.

Method: We used a model of newborn mouse chondrocytes and human osteoarthritis (OA) chondrocytes in primary culture stimulated with or without IL-1beta (10 ng/ml), for 18 h.

Allium compounds, dipropyl and dimethyl thiosulfinates as antiproliferative and differentiating agents of human acute myeloid leukemia cell lines.

Epidemiologic studies support the premise that Allium vegetables may lower the risk of cancers. The beneficial effects appear related to the organosulfur products generated upon processing of Allium. Leukemia cells from patients with acute myeloid leukemia (AML) display high proliferative capacity and have a reduced capacity of undergoing apoptosis and maturation.

On the use of symmetry in the ab initio quantum mechanical simulation of nanotubes and related materials.

Nanotubes can be characterized by a very high point symmetry, comparable or even larger than the one of the most symmetric crystalline systems (cubic, 48 point symmetry operators). For example, N = 2n rototranslation symmetry operators connect the atoms of the (n,0) nanotubes. This symmetry is fully exploited in the CRYSTAL code.

Using classical population genetics tools with heterochroneous data: time matters!

Background: New polymorphism datasets from heterochroneous data have arisen thanks to recent advances in experimental and microbial molecular evolution, and the sequencing of ancient DNA (aDNA). However, classical tools for population genetics analyses do not take into account heterochrony between subsets, despite potential bias on neutrality and population structure tests. Here, we characterize the extent of such possible biases using serial coalescent simulations.

Classification and basic pathology of Alzheimer disease.

The lesions of Alzheimer disease include accumulation of proteins, losses of neurons and synapses, and alterations related to reactive processes. Extracellular Abeta accumulation occurs in the parenchyma as diffuse, focal or stellate deposits. It may involve the vessel walls of arteries, veins and capillaries.

Involvement of the Notch pathway in the regulation of matrix metalloproteinase 13 and the dedifferentiation of articular chondrocytes in murine cartilage.

Objective: To demonstrate the activation of the Notch signaling pathway during changes in the phenotype of chondrocytes in vitro, and to assess the influence of Notch on the production of chondrocyte markers.

Methods: Serial monolayer primary cultures of murine articular chondrocytes (MACs), as a model of chondrocyte dedifferentiation, were prepared. MACs were cultured with or without a Notch inhibitor and transfected with different Notch-expressing vectors.

Adult-onset Still disease.

Adult-onset Still disease (AOSD) is an uncommon inflammatory condition of unknown origin typically characterized by four main (cardinal) symptoms: spiking fever > or =39 degrees C, arthralgia or arthritis, skin rash and hyperleucocytosis (> or =10,000 cells/mm3) with neutrophils > or =80%. As many other manifestations are possible, diagnosis is potentially challenging. Determination of the total and glycosylated ferritin levels, although not pathognomonic, can help in diagnosis.

Cholesterol in the senile plaque: often mentioned, never seen.

The lipid components of the senile plaque (SP) remain largely unknown. Senile plaques were said to be enriched in cholesterol in a few studies using the cholesterol probe filipin and a histoenzymatic method based upon cholesterol oxidase activity. We provide data that strongly suggest that these results are false-positive: the SPs were still stained in the absence of the enzyme cholesterol oxidase; filipin still labeled the plaques after lipid extraction.

Mechanical stress and prostaglandin E2 synthesis in cartilage.

Knee osteoarthritis (OA) results, at least in part, from overloading and inflammation leading to cartilage degradation. Prostaglandin E2 (PGE2) is one of the main catabolic factors involved in OA in which metalloproteinase (MMP) is crucial for cartilage degradation. Its synthesis is the result of cyclooxygenase (COX) and prostaglandin E synthase (PGES) activities whereas NAD+-dependent 15 hydroxy-prostaglandin dehydrogenase (15-PGDH) is the key enzyme implicated in the catabolism of PGE2.

Primary culture and phenotyping of murine chondrocytes.

The culture of chondrocytes is one of the most powerful tools for exploring the intracellular and molecular features of chondrocyte differentiation and activation. However, chondrocytes tend to dedifferentiate into fibroblasts when they are subcultured, which is a major problem. This protocol, involving primary cultures to limit dedifferentiation, describes two different methods for culturing chondrocytes of different anatomical origins (articular and costal chondrocytes, both of which represent hyaline cartilage) from mice.