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Braverman Y.,Kimron Veterinary Institute | Frish K.,Kimron Veterinary Institute | Reis M.,Bar - Ilan University | Mumcuoglu K.Y.,The Institute for Medical Research Israel Canada
Entomologia Generalis | Year: 2012

Host preference determines which host will be bitten and therefore potentially be infected with vectored pathogenic microorganisms by hematophagous arthropods such as Culicoides. In Israel, the feeding behavior of 8 out of 60 Culicoides species was confirmed by using the precipitin tests. In the present study several morphometric parameters, which characterize bird and mammal feeders were used. By means of the number of antennomer bearing sensilla coeloconica, the following fourteen probable mammal feeders could be detected: Culicoides derisor, Culicoides fagineus, Culicoides fascipennis, Culicoides imicola, Culicoides montanus, Culicoides newsteadi, Culicoides obsoletus, Culicoides pulicaris, Culicoides punctatus, Culicoides puncticollis, Culicoides schultzei group, Culicoides shaklawensis, Culicoides pallidicornis, and Culicoides vitreipennis. In addition, the following eighteen probable bird feeders were identified: Culicoides begueti, Culicoides brunnicans, Culicoides cataneii, Culicoides circumscriptus, Culicoides kibunensis, Culicoides distinctipennis, Culicoides gejgelensis, Culicoides haranti, Culicoides indistinctus, Culicoides odiatus, Culicoides maritimus, Culicoides festivipennis, Culicoides pseudopallidus, Culicoides griseidorsum, Culicoides sejfadinei, Culicoides simulator and Culicoides univittatus. The probable bird feeders possessed a significantly larger third palpal segment. The values of the antennal ratio in probable feeders on birds were signifi-cantly higher than those in probable mammal feeders. The number of bulb-shaped sensilla in the pit of the third palpal segment was found unreliable for determining host groups. © 2012 E. Schweizerbart'sche Verlagsbuchhandlung, D-70176 Stuttgart.


Gur C.,The Institute for Medical Research Israel Canada | Gur C.,Hebrew University of Jerusalem | Enk J.,The Institute for Medical Research Israel Canada | Enk J.,Hebrew University of Jerusalem | And 15 more authors.
PLoS ONE | Year: 2013

NK cells rapidly kill tumor cells, virus infected cells and even self cells. This is mediated via killer receptors, among which NKp46 (NCR1 in mice) is prominent. We have recently demonstrated that in type 1 diabetes (T1D) NK cells accumulate in the diseased pancreas and that they manifest a hyporesponsive phenotype. In addition, we found that NKp46 recognizes an unknown ligand expressed by beta cells derived from humans and mice and that blocking of NKp46 activity prevented diabetes development. Here we investigated the properties of the unknown NKp46 ligand. We show that the NKp46 ligand is mainly located in insulin granules and that it is constitutively secreted. Following glucose stimulation the NKp46 ligand translocates to the cell membrane and its secretion decreases. We further demonstrate by using several modalities that the unknown NKp46 ligand is not insulin. Finally, we studied the expression of the NKp46 ligand in type 2 diabetes (T2D) using 3 different in vivo models and 2 species; mice and gerbils. We demonstrate that the expression of the NKp46 ligand is decreased in all models of T2D studied, suggesting that NKp46 is not involved in T2D. © 2013 Gur et al.


Wikstrom J.D.,Hebrew University of Jerusalem | Israeli T.,Hebrew University of Jerusalem | Bachar-Wikstrom E.,Hebrew University of Jerusalem | Swisa A.,The Institute for Medical Research Israel Canada | And 6 more authors.
Molecular Endocrinology | Year: 2013

Experimental lipotoxicity constitutes a model for β-cell demise induced by metabolic stress in obesity and type 2 diabetes. Fatty acid excess induces endoplasmic reticulum (ER) stress, which is accompanied by ER morphological changes whose mechanisms and relevance are unknown. We found that the GTPase dynamin-related protein 1 (DRP1), a key regulator of mitochondrial fission, is an ER resident regulating ER morphology in stressed β-cells. Inhibition of DRP1 activity using a GTP hydrolysis-defective mutant (Ad-K38A) attenuated fatty acid-induced ER expansion and mitochondrial fission. Strikingly, stimulating the key energy-sensor AMP-activated protein kinase (AMPK) increased the phosphorylation at the anti-fission site Serine 637 and largely prevented the alterations in ER and mitochondrial morphology. Expression of a DRP1 mutant resistant to phosphorylation at this position partially prevented the recovery of ER and mitochondrial morphology by AMPK. Fatty acid-induced ER enlargement was associated with proinsulin retention in the ER, together with increased proinsulin/insulin ratio. Stimulation of AMPK prevented these alterations, as well as mitochondrial fragmentation and apoptosis. In summary, DRP1 regulation by AMPK delineates a novel pathway controlling ER and mitochondrial morphology, thereby modulating the response of β-cells to metabolic stress. DRP1 may thus function as a node integrating signals from stress regulators, such as AMPK, to coordinate organelle shape and function. © 2013 by The Endocrine Society.


PubMed | Health Science University, The Institute for Medical Research Israel Canada and Addis Ababa Institute of Technology
Type: | Journal: Parasites & vectors | Year: 2015

Phlebotomus orientalis feeds on a variety of wild and domestic animals and transmits Leishmania donovani from hitherto unknown reservoir hosts to humans in extra-domestic habitats in the Metema-Humera lowlands. The aim of this study was to determine the nocturnal activities of P. orientalis and its preferred blood meal hosts.Collections of Phlebotomus orientalis were made by using CDC light traps to determine the density as P. orientalis/hour CDC trap and preference to rodents by using Turners traps in agricultural fields, animal shelters and thickets of Acacia seyal in Baeker site-1 and Gelanzeraf site-2. The blood meal sources were detected by Reverse Line Blot (RLB) of cytochrome b polymerase chain reaction (PCR) amplification in August, 2012 from collections of sand flies in thickets of A. seyal (March 2011) and dense mixed forest (July 2011) in Baeker site 1. RLB PCR involved first amplification of animal specific sequences of cytochrome b using PCR techniques. Then the amplified sequence was hybridized with 11 species-specific probes for domestic animals adsorbed on nitrocellulose membrane for calorimetric color detection.A total of 6,083 P. orientalis (2,702 males and 3,381 females) were collected at hourly intervals using 22 CDC traps from January to May 2013. The peak activities of P. orientalis were at 1.00 a.m (134.07.21) near animal shelters, 3.00 a.m (66.3346.40) in agricultural fields and 21:00 pm (40.630.06) in thickets of A. seyal. This species was not attracted to the different species of rodents in trials carried out in March and April 2013. RLB PCR identified 7 human (28%), 9 mixed (human and cattle) (36%) and 2 cattle (8%) blood meals while 7 were unknown (28%).Female P. orientalis can bite humans in extra-domestic habitats of Kafta-Humera lowlands at any hour of the night with peak biting after midnight.


PubMed | The Institute for Medical Research Israel Canada
Type: Journal Article | Journal: The Journal of neuroscience : the official journal of the Society for Neuroscience | Year: 2010

Activity of single neurons in the motor cortex has been shown to change during acquisition of motor skills. We previously reported that the combined activity of cell ensembles in the motor cortex of monkeys (Macaca fascicularis) evolves during adaptation to a novel force field perturbation to encode the direction of compensatory force when reaching to visual targets. We also showed that the population directional signal was altered by the available sensory feedback. Here, we examined whether traces of such activity would linger on to later constitute motor memories of the newly acquired skill and whether memory traces would differ depending on feedback. We found that motor-cortical cell ensembles retained features of their adaptive activity pattern in the absence of perturbation when reaching to both learned and unlearned targets. Moreover, the preferred directions of these cells rotated in the direction of force field while the entire population of cells produced no net rotation of preferred direction when returning to null-field reaches. Whereas the activity pattern and preferred direction rotations were comparable with and without visual feedback, changes in tuning amplitudes differed across feedback conditions. Last, savings in behavioral performance and neuronal activity during later reexposure to force field were apparent. Overall, the findings reflect a novel representation of motor memory by cell ensembles and indicate a putative role of the motor cortex in early acquisition of motor memory.

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