Expression of the guanine nucleotide exchange factor, mr-gef, is regulated during the differentiation of specific subsets of telencephalic neurons

We have performed a screen combining subtractive hybridization with PCR to isolate genes that are regulated when neuroepithelial (NE) cells differentiate into neurons. From this screen, we have isolated a number of known genes that have not previously been associated with neurogenesis, together with several novel genes. Here we report that one of these genes, encoding a guanine nucleotide exchange factor (GEF), is regulated during the differentiation of distinct neuronal populations. We have cloned both rat and mouse GEF genes and shown that they are orthologs of the human gene, MR-GEF, which encodes a GEF that specifically activates the small GTPase, Rap1. We have therefore named the rat gene rat mr-gef (rmr-gef) and the mouse gene mouse mr-gef (mmr-gef). Here, we will collectively refer to these two rodent genes as mr-gef. Expression studies show that mr-gef is expressed by young neurons of the developing rodent CNS but not by progenitor cells in the ventricular zone (VZ). The expression pattern of mr-gef during early telencephalic neurogenesis is strikingly similar to that of GABA and the LIM homeobox gene Lhx6, a transcription factor expressed by GABAergic interneurons generated in the ventral telencephalon, some of which migrate into the cortex during development. These observations suggest that mr-gef encodes a protein that is part of a signaling pathway involved in telencephalic neurogenesis; particularly in the development of GABAergic interneurons.

The effect of flavanol-rich cocoa on cerebral perfusion in healthy older adults during conscious resting state: a placebo controlled, crossover, acute trial

Rationale: There has recently been increasing interest in the potential of flavanols, plant derived compounds found in foods such as fruit and vegetables, to ameliorate age-related cognitive decline. Research suggests that cocoa flavanols improve memory and learning, possibly as a result of their anti-inflammatory and neuroprotective effects. These effects may be mediated by increased cerebral blood flow (CBF), thus stimulating neuronal function. Objectives: The present study employed arterial spin labelling (ASL) functional magnetic resonance imaging (FMRI) to explore the effect of a single acute dose of cocoa flavanols on regional CBF. Methods: CBF was measured pre and post consumption of low (23mg) or high (494mg) 330ml equicaloric flavanol drinks matched for caffeine, theobromine, taste and appearance according to a randomised counterbalanced crossover double-blind design in eight males and ten females, aged 50-65 years. Changes in perfusion from pre to post consumption were calculated as a function of each drink. Results: Significant increases in regional perfusion across the brain were observed following consumption of the high flavanol drink relative to the low flavanol drink, particularly in the anterior cingulate cortex (ACC) and the central opercular cortex of the parietal lobe. Conclusions: Consumption of cocoa flavanol improves regional cerebral perfusion in older adults. This provides evidence for a possible acute mechanism by which cocoa flavanols are associated with benefits for cognitive performance.

Arterial spin labeling of cerebral perfusion territories using a seperate labeling coil

Purpose: To obtain cerebral perfusion territories of the left, the right. and the posterior circulation in humans with high signal-to-noise ratio (SNR) and robust delineation. Materials and Methods: Continuous arterial spin labeling (CASL) was implemented using a dedicated radio frequency (RF) coil. positioned over the neck, to label the major cerebral feeding arteries in humans. Selective labeling was achieved by flow-driven adiabatic fast passage and by tilting the longitudinal labeling gradient about the Y-axis by theta = +/- 60 degrees. Results: Mean cerebral blood flow (CBF) values in gray matter (GM) and white matter (WM) were 74 +/- 13 mL center dot 100 g(-1) center dot minute(-1) and 14 +/- 13 mL center dot 100 g(-1) center dot minute(-1), respectively (N = 14). There were no signal differences between left and right hemispheres when theta = 0 degrees (P > 0.19), indicating efficient labeling of both hemispheres. When theta = +60 degrees, the signal in GM on the left hemisphere, 0.07 +/- 0.06%, was 92% lower than on the right hemisphere. 0.85 +/- 0.30% (P < 1 x 10(-9)). while for theta = -60 degrees, the signal in the right hemisphere. 0.16 +/- 0.13%, was 82% lower than on the contralateral side. 0.89 +/- 0.22% (P < 1 x 10(-10)). Similar attenuations were obtained in WM. Conclusion: Clear delineation of the left and right cerebral perfusion territories was obtained, allowing discrimination of the anterior and posterior circulation in each hemisphere.

Mår kvinnliga lärare sämre än manliga?

Stress på jobbet har väckt stor uppmärksamhet de senaste åren. Generellt kan man säga att den psykiska ohälsan ökar. Kvinnor och lärare är överrepresenterade bland de utbrända. Syftet med undersökningen var att genom en enkätstudie ta reda på om det fanns några könsskillnader gällande mäns och kvinnors psykiska ohälsa på två gymnasier i Dalarna. Undersökningen bestod av ett frågeformulär bestående av 18 frågor. Sammanlagt 78 personer valde att delta i studien. Resultatet visade inga signifikanta könsskillnader. Man kan däremot utläsa en tendens till att kvinnorna mår sämre än männen. Då tidigare forskning pekar mot att kvinnor mår sämre än män, kan undersökningens utslag bero på för få deltagare eller på undersökningens låga svarsfrekvens.

Skolsköterskans upplevelse av att arbeta med barn och ungdomar som mår psykiskt dåligt : En intervjustudie med kvalitativ ansats

Syfte: Att beskriva skolsköterskans upplevelse av att arbeta med barn och ungdomar som mår psykiskt dåligt, det preventiva arbetet samt samarbetet med andra vårdgivare.Metod: Studien har en kvalitativ design med fenomenologisk ansats. Deltagare i studien var fem skolsköterskor i en svensk kommun. Utgången i intervjun var tre stora öppna frågor i området "skolsköterskans upplevelse av att arbeta med barn och unga som mår psykiskt dåligt". Analysen genomfördes med hjälp av Kvales metod för analys, så kallad meningskoncentrering, vilket skedde efter transkribering i tre steg. Resultat: Analysen resulterade i följande deskriptiva teman. Viktigt arbete, Tidsbrist, Känslor av otillräcklighet, Barnens företrädare, Att skapa tillit, Tillgänglighet, Betydelsen av preventiva metoder, Betydelsen av samarbete inom skolan, Samarbete med föräldrar - en svår gränsdragning, Socialtjänstens sekretess försvårar arbetet, Utebliven remisshantering försvårar samarbetet med BUP samt "Hål i organisationen".Slutsats: Skolsköterskorna ansåg att det var viktigt att arbeta för psykisk hälsa hos eleverna. De upplevde tidspressen som ett hinder i arbetet med detta, vilket var frustrerande. Alla informanter önskade få möjlighet att arbeta mer preventivt. Samarbetet med lärare, kuratorer och föräldrar var betydelsefullt för att kunna hjälpa barnen. Samarbetet med andra vårdgivare upplevdes skiftande. Samtliga informanter var dock överens om att samarbetet kan förbättras.

Dancing with Mr. Penrose and other stories

Stories: Fallen Angel The Inheritance Schlog's Dance The New World Dancing With Mr. Penrose

Maintaining Tissue Perfusion in High-Risk Surgical Patients: A Systematic Review of Randomized Clinical Trials

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Gastric mucosal perfusion in dogs: Effects of halogenated anesthetics and of hemorrhage

The gastrointestinal tract is one of the first organs affected by hypoperfusion during hemorrhagic shock. The hemodynamics and oxygen transport variables during hemorrhagic shock and resuscitation can be affected by the anesthetics used. In a model of pressure-guided hemorrhagic shock in dogs, we studied the effects of three halogenated anesthetics - halothane, sevoflurane, and isoflurane - at equipotent concentrations on gastric oxygenation. Thirty dogs were anesthetized with 1.0 minimum alveolar anesthetic concentration (MAC) of either halothane, sevoflurane, or isoflurane. A gastric tonometer was placed in the stomach to determine mucosal gastric CO2 (PgCO(2)) and for the calculation of gastric-arterial PCO2 gradient (PCO2 gap). The dogs were splenectomized and hemorrhaged to hold mean arterial pressure at 40-50 mm Hg over 45 min and then resuscitated with the shed blood volume. Hemodynamics, systemic oxygenation, and PCO2 gap were measured at baseline, after 45 min of hemorrhage, and at 15 and 60 min after blood resuscitation. Hemorrhage induced reductions of mean arterial pressure and cardiac index, while systemic oxygen extraction increased (p < .05), without significant differences among groups (p > .05). Halothane group showed significant lower PCO2 gap values than the other groups (p < .05). After 60 min of shed blood replacement, all groups restored hemodynamics, systemic oxygenation, and PCO2 gap to the prehemorrhage levels (p > .05), without significant differences among groups (p > .05). We conclude that halothane is superior to preserve the gastric mucosal perfusion in comparison to isoflurane and sevoflurane, in dogs submitted to pressure-guided hemorrhagic shock at equipotent doses of halogenated anesthetics.