Dielectric selective mirror for intracavity wavelength selection in far-infrared p-Ge lasers

A robust metal-free intracavity fixed-wavelength selector for the cryogenically cooled far-infrared p-Ge laser is demonstrated. The device is a back mirror consisting of a thin silicon etalon and dielectric SrTiO3 flat. A laser line width of 0.2 cm-1 is achieved, which corresponds to an active cavity finesse of similar to0.15. The wavelength position and spectral purity are maintained over a wide range of laser operating fields. Use of SrTiO3 lowers the laser resonance line frequencies by similar to1 cm-1 compared with expectations for metal mirrors. The effect is due to phase shift, which is determined from far-infrared reflectivity measurements of SrTiO3. A p-Ge laser with such selector is free from danger of electrical breakdown and mirror oxidation during repeatable thermal cycling, which makes it more reliable than previous selection schemes for practical applications

Posterior reversible encephalopathy syndrome in a child with cyclical vomiting and hypertension: a case report

<p>Abstract</p> <p>Introduction</p> <p>Posterior reversible encephalopathy syndrome is characterized by headache, nausea and vomiting, seizures and visual disturbances. It has certain characteristic radiological features, which allow diagnosis in the appropriate clinical setting and enable appropriate clinical therapy to be instituted.</p> <p>Case presentation</p> <p>A 10-year-old Caucasian girl who was hospitalized due to recurrent vomiting was diagnosed as having posterior reversible encephalopathy syndrome after an initial diagnosis of cyclical vomiting and hypertension was made.</p> <p>Conclusion</p> <p>Posterior reversible encephalopathy syndrome is a rare disorder in children. Early recognition of characteristic radiological features is key to the diagnosis as clinical symptoms may be non-specific or mimic other neurological illnesses. To the best of our knowledge this is the first case to report an association between posterior reversible encephalopathy syndrome, cyclical vomiting and hypertension. Furthermore, in this case, the resolution of the abnormalities found on magnetic resonance imaging over time did not appear to equate with clinical recovery.</p

A survey of emergency department use in patients with cyclic vomiting syndrome

<p>Abstract</p> <p>Background</p> <p>Cyclic vomiting syndrome (CVS), a chronic disorder characterized by recurrent episodes of vomiting, is frequently unrecognized and is associated with high utilization of emergency department (ED) services.</p> <p>Methods</p> <p>A web-based survey was posted on the Cyclic Vomiting Syndrome Association (CVSA) website to assess utilization of ED services in patients with CVS.</p> <p>Results</p> <p>Of 251 respondents, 104 (41.4%) were adult CVS patients and 147 (58.6%) were caregivers of pediatric and adult patients. In the adult group, the median number of ED visits for CVS symptoms was 15(range 1 - 200), with a median of 7 ED visits prior to a diagnosis of CVS (range 0 - 150). In the caregiver group, the median number of ED visits was 10 (range 1 - 175) and the median number of ED visits prior to a diagnosis of CVS was 5 (range 0 - 65). CVS was not diagnosed in the ED in 89/104 (93%) adults and 119/147 (93%) patients in the caregiver group. CVS was not recognized in the ED in 84/95 (88%) of adults and 97/122 (80%) of patients in the caregiver group, despite an established diagnosis of CVS.</p> <p>Conclusion</p> <p>There is a sub-group of adult and pediatric CVS patients who are high utilizers of ED services and CVS is not recognized in the ED in the majority of patients. Improved efforts to educate ED physicians are indicated to optimize treatment of patients with CVS and to decrease potential overuse of ED services.</p

Cyclic vomiting syndrome in adults

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72300/1/j.1365-2982.2008.01113.x.pd

Task shifting: the answer to the human resources crisis in Africa?

Ever since the 2006 World Health Report advocated increased community participation and the systematic delegation of tasks to less-specialized cadres, there has been a great deal of debate about the expediency, efficacy and modalities of task shifting

Mechanosensitive Enteric Neurons in the Myenteric Plexus of the Mouse Intestine

BACKGROUND: Within the gut the autonomous enteric nervous system (ENS) is able to sense mechanical stimuli and to trigger gut reflex behaviour. We previously proposed a novel sensory circuit in the ENS which consists of multifunctional rapidly adapting mechanosensitive enteric neurons (RAMEN) in the guinea pig. The aim of this study was to validate this concept by studying its applicability to other species or gut regions. METHODOLOGY/PRINCIPAL FINDINGS: We deformed myenteric ganglia in the mouse small and large intestine and recorded spike discharge using voltage sensitive dye imaging. We also analysed expression of markers hitherto proposed to label mouse sensory myenteric neurons in the ileum (NF145kD) or colon (calretinin). RAMEN constituted 22% and 15% of myenteric neurons per ganglion in the ileum and colon, respectively. They encoded dynamic rather than sustained deformation. In the colon, 7% of mechanosensitive neurons fired throughout the sustained deformation, a behaviour typical for slowly adapting echanosensitive neurons (SAMEN). RAMEN and SAMEN responded directly to mechanical deformation as their response remained unchanged after synaptic blockade in low Ca(++)/high Mg(++). Activity levels of RAMEN increased with the degree of ganglion deformation. Recruitment of more RAMEN with stronger stimuli may suggest low and high threshold RAMEN. The majority of RAMEN were cholinergic but most lacked expression of NF145kD or calretinin. CONCLUSIONS/SIGNIFICANCE: We showed for the first time that fundamental properties of mechanosensitive enteric neurons, such as firing pattern, encoding of dynamic deformation, cholinergic phenotype and their proportion, are conserved across species and regions. We conclude that RAMEN are important for mechanotransduction in the ENS. They directly encode dynamic changes in force as their firing frequency is proportional to the degree of deformation of the ganglion they reside in. The additional existence of SAMEN in the colon is likely an adaptation to colonic motor patterns which consist of phasic and tonic contractions

The Mast Cell Degranulator Compound 48/80 Directly Activates Neurons

Background Compound 48/80 is widely used in animal and tissue models as a “selective” mast cell activator. With this study we demonstrate that compound 48/80 also directly activates enteric neurons and visceral afferents. Methodology/Principal Findings We used in vivo recordings from extrinsic intestinal afferents together with Ca++ imaging from primary cultures of DRG and nodose neurons. Enteric neuronal activation was examined by Ca++ and voltage sensitive dye imaging in isolated gut preparations and primary cultures of enteric neurons. Intraluminal application of compound 48/80 evoked marked afferent firing which desensitized on subsequent administration. In egg albumen-sensitized animals, intraluminal antigen evoked a similar pattern of afferent activation which also desensitized on subsequent exposure to antigen. In cross-desensitization experiments prior administration of compound 48/80 failed to influence the mast cell mediated response. Application of 1 and 10 µg/ml compound 48/80 evoked spike discharge and Ca++ transients in enteric neurons. The same nerve activating effect was observed in primary cultures of DRG and nodose ganglion cells. Enteric neuron cultures were devoid of mast cells confirmed by negative staining for c-kit or toluidine blue. In addition, in cultured enteric neurons the excitatory action of compound 48/80 was preserved in the presence of histamine H1 and H2 antagonists. The mast cell stabilizer cromolyn attenuated compound 48/80 and nicotine evoked Ca++ transients in mast cell-free enteric neuron cultures. Conclusions/Significance The results showed direct excitatory action of compound 48/80 on enteric neurons and visceral afferents. Therefore, functional changes measured in tissue or animal models may involve a mast cell independent effect of compound 48/80 and cromolyn

Inter-connection between land use/land cover change and herders’/farmers’ livestock feed resource management strategies: a case study from three Ethiopian eco-environments

AbstractWe assessed land use/land cover changes from remotely sensed satellite imagery and compared this with community perceptions on availability/use of livestock feed resources and feed deficit management strategies since the 1973s in three districts representing the pastoral, agro-pastoral and mixed crop-livestock eco-environments of Ethiopia. We found that land use/land cover changes are proceeding in all eco-environments and that transitions are from grasslands, and forest lands to bush/shrub lands and crop lands in the pastoral site (Liben), from bush/shrub lands and grasslands to crop lands in agro-pastoral site (Mieso) and from bush/shrub lands, forest lands and grasslands to crop lands in the mixed crop-livestock site (Tiyo). The changes significantly affected livestock feed resources and feed deficit management strategies available to households. Over the last 30–40 years, grazing resources available to livestock keepers have been declining with resultant increase in the contribution of crop residues and other feeds from crop lands (weeds and crop thinnings) as compared to feeds from grasslands. The feed deficit management strategies of households are also changing significantly from mobility to herd management and feed conservation in the pastoral areas; from mobility to feed conservation and purchasing of feed in the agro-pastoral areas and from transhumance to feed conservation and purchase of feed in the mixed crop-livestock areas. Hence feed resources and their availability vary with time and eco-environments indicating the need for the development of eco-environment/site specific feed management strategies in order to support productive stock in the study areas and similar eco-environments

Binding of Gemini Bisbenzimidazole Drugs with Human Telomeric G-Quadruplex Dimers: Effect of the Spacer in the Design of Potent Telomerase Inhibitors

The study of anticancer agents that act via stabilization of telomeric G-quadruplex DNA (G4DNA) is important because such agents often inhibit telomerase activity. Several types of G4DNA binding ligands are known. In these studies, the target structures often involve a single G4 DNA unit formed by short DNA telomeric sequences. However, the 3′-terminal single-stranded human telomeric DNA can form higher-order structures by clustering consecutive quadruplex units (dimers or n-mers). Herein, we present new synthetic gemini (twin) bisbenzimidazole ligands, in which the oligo-oxyethylene spacers join the two bisbenzimidazole units for the recognition of both monomeric and dimeric G4DNA, derived from d(T2AG3)4 and d(T2AG3)8 human telomeric DNA, respectively. The spacer between the two bisbenzimidazoles in the geminis plays a critical role in the G4DNA stability. We report here (i) synthesis of new effective gemini anticancer agents that are selectively more toxic towards the cancer cells than the corresponding normal cells; (ii) formation and characterization of G4DNA dimers in solution as well as computational construction of the dimeric G4DNA structures. The gemini ligands direct the folding of the single-stranded DNA into an unusually stable parallel-stranded G4DNA when it was formed in presence of the ligands in KCl solution and the gemini ligands show spacer length dependent potent telomerase inhibition properties

Dual alpha2C/5HT1A receptor agonist allyphenyline induces gastroprotection and inhibits fundic and colonic contractility

Allyphenyline, a novel α2-adrenoceptor (AR) ligand, has been shown to selectively activate α2C-adrenoceptors (AR) and 5HT1A receptors, but also to behave as a neutral antagonist of α2A-ARs. We exploited this unique pharmacological profile to analyze the role of α2C-ARs and 5HT1A receptors in the regulation of gastric mucosal integrity and gastrointestinal motility