[Evaluation of TNF-alpha and IL-6 release in the ventroposterolateral nucleus of the thalamus during central neuropathic pain induced by electrical injury of the spinothalamic tract in male rats: a microdialysis study]

Inflammation and proinflammatory cytokines play an important role in the initiation and maintenance of central neuropathic pain. There are several reports that cytokine production is increased at the lesion site following spinal injury. A few studies have investigated the supraspinal levels of these cytokines. This study intended to determine TNF-alpha and IL-6 release in the ventroposterolateral nucleus of the thalamus in spinal cord injury-related neuropathic pain in rats. Male Sprague-Dawley rats that weighed 200-230 g were used. Following administration of anesthesia, spinothalamic tract injury was performed by a laminectomy at the T9-T10 level in male rats. Mechanical allodynia and motor performance were evaluated at 3, 7, 14, 21 and 28 days after spinal injury by Von Frey filament and the open field test, respectively, in the sham and lesion groups. Concentrations of TNF-alpha and IL-6 in the VPL microdialysate were detected by ELISA in both spinal cord injured and sham groups during four weeks after surgery. Mechanical pain threshold reduced in both hind paws following lateral spinothalamic tract injury. Paw withdrawal threshold in the Spinothalamic tract-injured group was significantly [P<0.05] lower than in sham group at day 14 post-surgery. Motor performance did not show any significant change after surgery. In the microdialysate, TNF-alpha reduced significantly [P<0.05] at days 3 and 7 post-injury compared to the sham group which returned to a level close to the pre-surgery level. VPL concentration of IL-6 increased significantly [P<0.05] at day 21 post-injury compared to the sham group. Lesions in spinal pathways that contain afferent pain fibers appear to change the supraspinal levels of inflammatory mediators, including VPL, concentrations of TNF-alpha and IL-6 which are consistent with spinal injury related pain behavior. Cytokine production results in hyperexcitability of the thalamocortical neurons, a decrease in pain threshold, and persistent neuropathic pain after spinal injury

model portraying experimental loss of hair cell: the use of distortion product otoacoustic emission in the assessment of rat's ear

The use of rats in research academies to study deafness is widespread, meanwhile medicinal methods to eliminate hair cells is also increasing. Thus, aminoglycosides and loop diuretics have grasped more attention. This study aimed at establishing an animal model in which a rapid distortion of the hair cell of cochlea administering amikacin and furosemide and using distortion product otoacoustic emission [DPOAE] the functioning of rat's ear would be assessed. Forty-eight male Sprague-Dawley rats [mean weight 200-250g] were randomly divided into six equal groups. Except the control group the rest received 0.5mg/g, 0.75mg/g, 1mg/g, 1.25mg/g, and 1.5mg/g, of subcutaneous amikacin respectively. 30 minutes later every rat received 0.1mg/g of furosemide intrapritoneally. DPOAE of rats was measured before these injections and 72 hours later. Then tissue sections of the rat's cochlea were prepared. All the cases had a significant decrease in their DPOAE with the frequencies 2KHz-8KHz [p

[ synthesis of chitosan / polyethylene nanofibersoxide on chitosan membrane: an applicable model in tissue engineering]

Nanofibers as nano-scaffolds are widely used in tissue engineering. Electrospun is away to produce these fiberes. In this study, the synthesis of chitosan nanofibers / polyethylene oxide [CS / PEO] on a very thin membrane of CS as a basement membrane has been investigated. For this purpose, composite solutions with volume fractions - density of CS and PEO, respectively, with ratios of 100 to zero [pure chitosan], 90 to 10 and 80 to 20 in Acetic Acid 5/0 M were prepared. Interactions of two polymers on each other were studied by Fourier transform infra-red spectroscopy [FTIR]. Nanofiber diameter and size were studied with Scanning Electron Microscope [SEM]. CS memebrane polymer solution on the interval the electric field kv 20-18 cm 15-10 and feed rate ml / h 5/0 was electrospun. Nanofiber diameter and size were studied by Scanning Electron Microscope [SEM]. FTIR study of the composite CS / PEO ratio of 20/80 and 10/90 peak tensile bond hydroxyl [OH] and [C = O] chitosan showed in certain areas. Scanning Electron Microscopic images showed that pure CS could not produce nanofibers on any ratios, and they appeared as a droplet. Whereas, nanofibers were created with ratios 80 to 20 and 90 to 10 of CS / PEO composite both on the aluminum foils and thin membrane of CS. It seems that high viscosity of pure CS prevents nanofibers formation. Whereas, homogeneous nanofibers obtained from the composite of CS / PEO with the ratios 80 to 20, 90 to 10 and pure CS on thin membrane of CS

[Study of the prophylactic effects of amifostine on decrease of lung tissue injuries in the acute phase in rats exposed to sulfur mustard]

Inhalation of Sulfur mustard [HD] will cause lung epithelial inflammation and injury. There are different results from the prophylactic effects of amifostine [AM] on protection of lung epithelial tissue against HD. The aim of this study was to evaluate the prophylactic effects of AM on protection of rat lung tissue exposed to HD. In this study twenty Albino Wistar adult male rats weighting 200 +/- 20 grams were used. Rats were divided randomly into 4 groups [5 rats in each group] as below: Normal saline group [NS], AM group, HD group [0.25% HD] and HD+AM group. Normal saline and HD solution were injected by intra tracheal catheter. Animals in AM and HD+AM groups received AM by intra peritoneal injection for 14 days daily. All rats were killed after 14 days; parts of the base of right lungs were removed, fixed and processed for histological evaluation by Toluidine blue, H and E staining and apoptotic cell death study by the TUNEL Apoptosis Detection Kit. In addition, glutathione level was measured in all specimens. No significant differences were revealed between Saline and AM groups in any of the aforementioned tests. Significant reduction of mast cells in lung tissue of the HD+AM group was shown when compared to the HD group. Lung tissue inflammation in the HD group was significantly more severe as compared to HD+AM group. In addition, amifostine in HD+AM group could prevent excess reduction of GSH level. The number of apoptotic cells in the HD group was significantly higher than the HD+AM group. Administration of amifostine before exposure to HD in rats prevents collection of mast cells, and excess reduction of GSH level in lung tissue; in addition it can partially reduce pulmonary edema and alveolar cell death apoptosis