6 results on '"Sahan E"'
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2. Q-VD-OPh, a pancaspase inhibitor, reduces trauma-induced apoptosis and improves the recovery of hind-limb function in rats after spinal cord injury
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Çolak, A., Antar, V., Karaoglan, A., Akdemir, O., Sahan, E., Çelik, Ö., and Sagmanligil, A.
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Q-VD-OPh ,Lesión medular traumática ,SCI ,Secondary damage ,Caspasa ,Spinal cord injury ,Lesión secundaria ,Caspase ,TUNEL - Abstract
Background. Various caspases have been implicated in the development of secondary damage after spinal cord injury (SCI). Anticaspase therapy that targets only one caspase has been investigated in a variety of in vitro and in vivo studies. This study examined the neuroprotective effects of Q-VD-OPh, a pan-caspase inhibitor, in a rat model of SCI. Methods. Thirty Wistar albino rats were divided into 3 groups of 10 each: the sham-operated controls (group 1), the trauma-created controls (group 2), and the QVD-OPh"treated rats (group 3). An SCI (a trauma of 40 g-cm) was produced at the thoracic level (T8-T10) by the weight-drop technique. The response to injury and the neuroprotective effects of Q-VD-OPh were investigated by histopathologic examination and terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) 24 hours and 5 days after trauma. The inclined plane technique of Rivlin and Tator and a modified version of Tarlov's grading scale were used to assess the functional status of the rats 24 hours, 3 days, and 5 days after injury. Results. Twenty-four hours after trauma, light microscopic examination of a specimen taken from group 2 rats revealed hemorrhage, necrosis, vascular thrombi, and edema. Group 3 tissue samples showed similar features at that time. Twenty-four hours after trauma, the mean apoptotic cell number was 4.47 ± 0.35 cells in group 2 and 1.58 ± 0.33 in group 3. Five days after injury, the mean apoptotic cell count was 4.35 ± 0.47 in group 2 and 1.25 ± 0.34 in group 3. Thus the number of TUNEL-positive cells in an injured spinal cord was greatly reduced by treatment with Q-VD-OPh. The neurologic function scores (both the inclined plane performance and motor grading scores) were significantly better in the Q-VD-OPh"treated group than in the trauma-created control group. Conclusion. The marked antiapoptotic properties of Q-VD-OPh due to the inhibition of all caspases render it a promising novel agent. A therapeutic strategy using Q-VD-OPh may eventually lead to the effective treatment of SCI in humans. Introducción. En el desarrollo de daño secundario tras lesión medular están implicadas diversas caspasas. La terapia anti-caspasas ha utilizado como diana una sola caspasa que ha sido investigada en una gran variedad de estudios tanto in-vitro como in-vivo. Estos estudios han examinado el efecto neuroprotector del Q-VD-PPh, un inhibidor pan-caspasa, en un modelo de lesión medular en rata. Material y métodos. Se dividieron 30 ratas Wistar en tres grupos de 10 ratas cada uno: una lesión medular traumática (con un trauma de 40 g-cm) se realizó a nivel torácico grupo control (grupo 1), grupo trauma control (grupo 2) y el grupo de ratas tratadas con Q-VD-OPh (grupo 3) se realizó a nivel torácico (T8-T10) mediante la técnica de caída de peso. La respuesta a la lesión y los efectos neuroprotectores de Q-VD-OPh se valoraron mediante el examen histopatológico y la técnica de TUNEL 24 horas y 5 días tras el traumatismo. Se usó la prueba del plano inclinado de Rivlin y Tator y una versión modificada de la escala de Tarlov para valorar el resultado funcional de las ratas 24 horas, 3 días y 5 días tras la lesión. Resultado. Veinticuatro horas tras la lesión, el estudio histopatológico de las secciones obtenidas del grupo 2 revelaron hemorragia, necrosis, trombos vasculares y edema. Las secciones obtenidos del grupo 3 mostraron hallazgos similares en ese momento. 24 horas tras la lesión el número de células apoptóticas fue 4.47 ± 0.35 en el grupo 2 y 1.58 ± 0.33 en el grupo 3. Cinco días tras la lesión el número medio de células apoptóticas fue de 4.35 ± 0.47 en el grupo 2 y de 1.25 ± 0.34 en el grupo 3. De esta forma el número de células TUNEL positivas en la médula dañada se redujo de forma considerable con el tratamiento con Q-VD-OPh. La función neurológica (tanto con el plano inclinado como con las escalas motoras) fueron significativamente mejores en el grupo de ratas tratadas mediante Q-VD-OPh que en el grupo control. Conclusión. Los marcados efectos antiapoptóticos de la Q-VD-OPh debido a la inhibición de todas las caspasas hace que sea un agente prometedor.
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- 2009
3. Calpain inhibitor AK 295 inhibits calpain-induced apoptosis and improves neurologic function after traumatic spinal cord injury in rats
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Colak, A., Kaya, M., Karaoglan, A., Sagmanligil, A., Akdemir, O., Sahan, E., and Celik, O.
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Calpain inhibitor ,Spinal cord trauma ,Lesión medular traumática ,AK 295 ,Inhibidor de la calpaina ,Secondary damage ,Apoptosis ,Lesión secundaria - Abstract
Background. An increase in the level of intracellular calcium activates the calcium-dependent neutral pro-tease calpain, which in turn leads to cellular dysfunction and cell death after an insult to the central nervous system. In this study, we evaluated the effect of a calpain inhibitor, AK 295, on spinal cord structure, neurologic function, and apoptosis after spinal cord injury (SCI) in a murine model. Methods. Thirty albino Wistar rats were divided into 3 groups of 10 each: the sham-operated control group (group 1), the spinal cord trauma group (group 2), and the spinal cord trauma plus AK 295 treatment group (group 3). After having received a combination of ketamine 60 mg/kg and xylazine 9 mg/kg to induce anesthesia, the rats in groups 2 and 3 were subjected to thoracic trauma by the weight drop technique (40 g-cm). One hour after having been subjected to that trauma, the rats in groups 2 and 3 were treated with an intraperitoneal injection of either dimethyl sulfoxide 2 mg/kg or AK 295 2 mg/kg. The effects of the injury and the efficacy of AK 295 were determined by an assessment of the TUNEL technique and the results of examination with a light microscope. The neurologic performance of 5 rats from group 2 and 5 from group 3 was assessed by means of the inclined plane technique and the modified Tarlov's motor grading scale 1, 3, and 5 days after spinal cord trauma. Findings. Light-microscopic examination of spinal cord specimens from group 2 revealed hemorrhage, edema, necrosis, and vascular thrombi 24 hours after trauma. Similar (but less prominent) features were seen in specimens obtained from group 3 rats. Twenty-four hours after injury, the mean apoptotic cell numbers in groups 1 and 2 were zero and 4.57 ± 0.37 cells, respectively. In group 3, the mean apoptotic cell number was2.30 ± 0.34 cells, a value significantly lower than that in group 2 (P < .05). Five days after trauma, the injured rats in group 2 demonstrated significant motor dysfunction (P < .05). In comparison, the motor scores exhibited by group 3 rats were markedly better (P < .05). Conclusions. AK 295 inhibited apoptosis via calpaindependent pathways and provided neuroprotection and improved neurologic function in a rat model of SCI. To our knowledge, this is the first study to evaluate the use of AK 295, a calpain inhibitor, after SCI. Our data suggest that AK 295 might be a novel therapeutic compound for the neuroprotection of tissue and the recovery of function in patients with a SCI. Introducción. Una lesión en el sistema nervioso central origina un incremento en los niveles de calcio intracelular que activa la proteasa neutral calcio-dependiente calpaina, que a su vez conduce a la producción de disfunción y muerte celular. En este estudio evaluamos el efecto de un inhibidor de la calpaina, AK 295, sobre la estructura de la médula espinal, la función neurológica y apoptosis tras lesión medular en un modelo murino. Métodos. Treinta ratas Wistar se dividieron en tres grupos de 10 ratas cada uno: Un grupo control (grupo 1), un grupo sometido a trauma espinal (grupo 2) y un grupo de ratas a las que se sometió a trauma medular y tratamiento con AK 295 (grupo 3). Después de recibir una combinación de ketamina 60mg/kg y xylazina 8mg/kg para la inducción anestésica, las ratas del grupo 2 y 3 fueron sometidas a trauma medular torácico mediante la técnica de caída de peso (40 g-cm). Una hora después de haber sufrido el traumatismo, las ratas del grupo 2 y 3 fueron tratadas mediante una inyección intraperitoneal bien de dimetil-sulfóxido 2mg/kg o de AK 295 2 mg/kg. Los efectos del traumatismo y la eficacia de AK 295 fueron determinados mediante la estimación de la técnica TUNEL y los resultados del examen del tejido mediante microscopía óptica. La función neurológica de 5 ratas del grupo 2 y 5 del grupo 3 fue estimada mediante la técnica del plano inclinado y la escala motora de Tarlov modificada a 1, 3 y 5 días desde el traumatismo medular. Resultados. El estudio mediante microscopía óptica de las preparaciones de médula espinal del grupo 2 demostró la existencia de hemorragia, edema, necrosis y trombosis vascular 24 horas tras el traumatismo. Hallazgos similares pero menos importantes se encontraron en las preparaciones procedentes del grupo 3. Veinticuatro horas tras el trauma, el número medio de células apoptóticas en los grupos 1 y 2 fueron cero y 4.57 ± 0.37 células respectivamente. En el grupo 3, el número medio de células apoptóticas fue de 2.30 ± 0.34 células, un valor significativamente menor que en el grupo 2 (p < 0.05). Cinco días tras el traumatismo, las ratas lesionadas en el grupo 2 demostraron una significativamente mayor disfunción neurológica (p
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- 2009
4. Ecological differentiation between sympatric pseudocryptic species in the estuarine benthic diatom Navicula phyllepta (Bacillariophyceae)
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Vanelslander, B., Créach, V., Vanormelingen, P., Ernst, A., Chepurnov, V.A., Sahan, E., Muijzer, G., Stal, L.J., Vyverman, W., Sabbe, K., Marine Microbiology, Microbial Wetland Ecology (MWE), and Aquatic Microbiology (IBED, FNWI)
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Diatoms ,Niches ,Salinity ,ANE, Netherlands, Westerschelde ,Navicula phyllepta ,Abundance ,Animal morphology ,RNA ,Bacillariophyceae [Featherlike diatoms] ,Environmental conditions ,Regression analysis ,Salinity tolerance - Abstract
The occurrence of cryptic and pseudocryptic species, often living in sympatry, is widespread among microalgae. This phenomenon raises important questions about niche partitioning between these closely related species. To date, however, few studies have addressed the ecological mechanisms underlying sympatry in cryptic and pseudocryptic species. As a result, we have only a limited understanding of the factors that govern their distribution along environmental gradients. Here, we used the ribosomal internal transcribed spacer (ITS), 18S rRNA gene, and the RUBISCO LSU (rbcL) chloroplast gene sequence data together with cell wall morphology to show that estuarine populations of the widespread and common benthic diatom Navicula phyllepta Kütz. consist of pseudocryptic species. Growth rate measurements in function of salinity showed that N. phyllepta strains assigned to the different species differed in their tolerance to low salinities (N. phyllepta sensu lato comprises different species with specialized ecophysiological characteristics rather than generalists with a broad adaptability to different environmental conditions.
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- 2009
5. State of the art of mitigation ampersand relation mitigation/adaptation
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Sahan, E., Lenstra, W.J., Verheggen, B., and Energieonderzoek Centrum Nederland
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- 2009
6. Carbon in Atmospheric Particulate Matter
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Brink, H.M. ten, Weijers, E.P., Sahan, E., and Energieonderzoek Centrum Nederland
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- 2008
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