scholarly journals Clinical and Histological Effects of the Intrathecal Administration of a Single Dose of Dexmedetomidine in Rabbits

2016 ◽  
Vol 19 (2;2) ◽  
pp. E319-E327 ◽  
Author(s):  
Eliana Marisa Ganem

Background: There is experimental evidence that dexmedetomidine has neuroprotective effects. So, it could be expected that its intrathecal or epidural administration presents no harm. However, whether dexmedetomidine is neurotoxic to the spinal cord remains to be fully elucidated. Objective: To evaluate the effect of preservative-free dexmedetomidine administered as a subarachnoid single injection on the spinal cord and meninges of rabbits. Study Design: Research article. Setting: Experimental research laboratory. Methods: Twenty young adult female rabbits, each weighing between 3200 and 4900 g, and having a spine length between 36 and 40 cm, were divided by lot into 2 groups (G): 0.9% saline in G1 and preservative-free dexmedetomidine in G2 (dose of 10 μg). After intravenous anesthesia with ketamine and xylazine, the subarachnoid space was punctured at S1-S2 under ultrasound guidance, and a random 5 µl.cm-1 of spinal length (0.2 mL) of solution (saline or dexmedetomidine) was injected. The animals remained in captivity for 21 days under medical observation and were sacrificed by decapitation. The lumbosacral spinal cord portion was removed for immunohistochemistry to assess the glial fibrillary acidic protein (GFAP), and histology was assessed using hematoxylin and eosin (HE) stain. Results: None of the animals had impaired motor function or decreased nociception during the period of clinical observation. None of the animals from the control group showed signs of injuries to meninges. In the dexmedetomidine group, however, 9 animals presented with signs of meningeal injury. The main histological changes observed were areas with meningeal thickening and lymphoplasmocitary infiltration in the pia-mater and arachnoid. Further histological examination also revealed adherence areas among the pia and arachnoid. There was no signal of injury in neural tissue in any animal of both groups. Limitations: Evaluation of the possible analgesic effects of the intrathecal dexmedetomidine was not performed. Conclusion: On the basis of the present results, dexmedetomidine administered in the subarachnoid space in a single dose of 10 µg is capable of producing histological changes over the meninges of rabbits. Key Words: Anesthesia, spinal; dexmedetomine; injections, spinal; spinal cord; rabbits

2011 ◽  
Vol 15 (4) ◽  
pp. 414-421 ◽  
Author(s):  
Junko Kawabe ◽  
Masao Koda ◽  
Masayuki Hashimoto ◽  
Takayuki Fujiyoshi ◽  
Takeo Furuya ◽  
...  

Object Granulocyte colony-stimulating factor (G-CSF) has neuroprotective effects on the CNS. The authors have previously demonstrated that G-CSF also exerts neuroprotective effects in experimental spinal cord injury (SCI) by enhancing migration of bone marrow–derived cells into the damaged spinal cord, increasing glial differentiation of bone marrow–derived cells, enhancing antiapoptotic effects on both neurons and oligodendrocytes, and by reducing demyelination and expression of inflammatory cytokines. Because the degree of angiogenesis in the subacute phase after SCI correlates with regenerative responses, it is possible that G-CSF's neuroprotective effects after SCI are due to enhancement of angiogenesis. The aim of this study was to assess the effects of G-CSF on the vascular system after SCI. Methods A contusive SCI rat model was used and the animals were randomly allocated to either a G-CSF–treated group or a control group. Integrity of the blood–spinal cord barrier was evaluated by measuring the degree of edema in the cord and the volume of extravasation. For histological evaluation, cryosections were immunostained with anti–von Willebrand factor and the number of vessels was counted to assess revascularization. Real-time reverse transcriptase polymerase chain reaction was performed to assess expression of angiogenic cytokines, and recovery of motor function was assessed with function tests. Results In the G-CSF–treated rats, the total number of vessels with a diameter > 20 μm was significantly larger and expression of angiogenic cytokines was significantly higher than those in the control group. The G-CSF–treated group showed significantly greater recovery of hindlimb function than the control group. Conclusions These results suggest that G-CSF exerts neuroprotective effects via promotion of angiogenesis after SCI.


2000 ◽  
Vol 93 (2) ◽  
pp. 287-290 ◽  
Author(s):  
Christopher G. Paramore

✓ Spinal arachnoid cysts are diverticula of the subarachnoid space that may compress the spinal cord; these lesions are most commonly found in the thoracic spine. Two patients who presented with thoracic myelopathy were noted on magnetic resonance imaging to have focal indentation of the dorsal thoracic cord, with syringomyelia inferior to the site of compression. Both patients were found at operation to have discrete arachnoid “webs” tenaciously attached to the dura mater and pia mater. These webs were not true arachnoid cysts, yet they blocked the flow of cerebrospinal fluid (CSF) and caused focal compression of the spinal cord. The mass effect appeared to be the result of a pressure gradient created by the obstruction of CSF flow in the dorsal aspect of the subarachnoid space. Both patients responded well to resection of the arachnoid web. Arachnoid webs appear to be rare variants of arachnoid cysts and should be suspected in patients with focal compression of the thoracic spinal cord.


2006 ◽  
Vol 25 (3) ◽  
pp. 127-133 ◽  
Author(s):  
M Kanter ◽  
O Coskun ◽  
M Kalayc ◽  
S Buyukbas ◽  
F Cagavi

The aim of this study was to investigate the possible beneficial effects of Nigella sativa (NS) in comparison to methylprednisolone on experimental spinal cord injury (SCI) in rats. SCI was performed by placing an aneurysm clip extradurally at the level of T11-12. Rats were neurologically tested over 24 h after trauma and spinal cord tissue samples were harvested for both biochemical and histopathological evaluation. The neurological scores of rats were not found to be different in SCI groups. SCI significantly increased the spinal cord tissue malondialdehyde (MDA) and protein carbonyl (PC) levels, however SCI decreased superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) enzyme activities compared to the control. Methylprednisolone and NS treatment decreased tissue MDA and PC levels and prevented inhibition of SOD, GSH-Px and CAT enzymes in the tissues. The most significant results were obtained when NS was given. In SCI and placebo groups, the neurons of spinal cord tissue became extensively dark and degenerated with picnotic nuclei. The morphology of neurons in methylprednisolone and NS-treated groups were well protected, however, not as well as the neurons of the control group. The number of neurons in the spinal cord tissue of the SCI and placebo groups was significantly less than the control, laminectomy, methylprednisolone and NS-treated groups. In conclusion, NS treatment might be beneficial in spinal cord tissue damage, and therefore shows potential for clinical implications.


2000 ◽  
Vol 93 (5) ◽  
pp. 1303-1311 ◽  
Author(s):  
Jeroen Lips ◽  
Peter de Haan ◽  
Pieter Bodewits ◽  
Ivo Vanicky ◽  
Misa Dzoljic ◽  
...  

Background Massive release of central excitatory neurotransmitters is an important initial step in ischemic neuronal injury, and modification of this process may provide neuroprotection. We studied the protective effects of the voltage-dependent sodium channel antagonist riluzole and the N-methyl-d-aspartate receptor antagonist ketamine on hind limb motor function and histopathologic outcome in an experimental model of spinal cord ischemia. Methods Temporary spinal cord ischemia was induced by 29 min of infrarenal balloon occlusion of the aorta in 60 anesthetized New Zealand white rabbits. Animals were randomly assigned to one of four treatment groups (n = 15 each): group C, saline (control); group R, riluzole, 8 mg/kg intravenously; group K, ketamine, 55 mg/kg intravenously; group RK, riluzole and ketamine. After reperfusion, riluzole treatment was continued with intraperitoneal infusions. Normothermia (38 degrees C) was maintained during ischemia, and rectal temperature was assessed before and after intraperitoneal infusions. Neurologic function, according to Tarlov's criteria, was evaluated every 24 h, and infarction volume and the number of eosinophilic neurons and viable motoneurons in the lumbosacral spinal cord was evaluated after 72 h. Results Neurologic outcome was better in groups R and RK than in groups C and K. All animals in group C (100%) and all animals but one in group K (93%) were paraplegic 72 h after the ischemic insult versus 53% in group R and 67% in group RK (P < 0.01 each). More viable motoneurons were present in groups R and RK than in controls (P < 0.05). Conclusions The data indicate that treatment with riluzole can increase the tolerance of spinal cord motoneurons to a period of normothermic ischemia. Intraischemic ketamine did not provide neuroprotection in this model.


2010 ◽  
Vol 132 (6) ◽  
Author(s):  
C. D. Bertram

A finite-element numerical model was constructed of the spinal cord, pia mater, filum terminale, cerebrospinal fluid in the spinal subarachnoid space (SSS), and dura mater. The cord was hollowed out by a thoracic syrinx of length 140 mm, and the SSS included a stenosis of length 30 mm opposite this syrinx. The stenosis severity was varied from 0% to 90% by area. Pressure pulse excitation was applied to the model either at the cranial end of the SSS, simulating the effect of cranial arterial pulsation, or externally to the abdominal dura mater, simulating the effect of cough. A very short pulse was used to examine wave propagation; a pulse emulating cardiac systole was used to examine the effects of fluid displacement. Additionally, repetitive sinusoidal excitation was applied cranially. Bulk fluid flow past the stenosis gave rise to prominent longitudinal pressure dissociation (“suck”) in the SSS adjacent to the syrinx. However, this did not proportionally increase the longitudinal motion of fluid in the syrinx. The inertia of the fluid in the SSS, together with the compliance of this space, gave a resonance capable of being excited constructively or destructively by cardiac or coughing impulses. The main effect of mild stenosis was to lower the frequency of this resonance; severe stenosis damped out to-and-fro motions after the end of the applied excitation. Syrinx fluid motion indicated the fluid momentum and thus the pressure developed when the fluid was stopped by the end of the syrinx; however, the tearing stress in the local cord material depended also on the instantaneous local SSS pressure and was therefore not well predicted by syrinx fluid motion. Stenosis was also shown to give rise to a one-way valve effect causing raised SSS pressure caudally and slight average cord displacement cranially. The investigation showed that previous qualitative predictions of the effects of suck neglected factors that reduced the extent of the resulting syrinx fluid motion and of the cord tearing stress, which ultimately determines whether the syrinx lengthens.


2021 ◽  
Vol In Press (In Press) ◽  
Author(s):  
Mehdi Goudarzi ◽  
Zahra Basir ◽  
Alireza Malayeri ◽  
Ali Nesari ◽  
Narjes Zaeemzadeh

Background: Methotrexate (MTX) is mainly used for the chemotherapy of different types of malignancy and some autoimmune diseases like rheumatoid arthritis and inflammatory bowel disease. The MTX application is limited by its severe side effects, including several types of hepatic injury. Objectives: In this study, we decided to evaluate if zingerone (the main constituent of ginger) can reduce the hepatic side effects of MTX. Methods: Thirty-five rats were divided into five groups: Control group receiving normal saline (N/S), once daily, by gavage, for 10 days, and N/S intraperitoneally (i.p.), a single dose on the ninth day; Methotrexate (MTX) group receiving N/S, once daily, by gavage, for 10 days, and MTX (i.p.), a single dose (20 mg/kg) on the ninth day; Groups 3 (ZG25), 4 (ZG50), and 5 (ZG100) receiving zingerone (25, 50, and 100 mg/kg, respectively), once daily, by gavage, for 10 days, and MTX (i.p.), a single dose (20 mg/kg) on the ninth day. Results: The results showed a significant decrease in serum AST, ALT, and ALP, as well as the hepatic content of MDA, NO, PC, TNF-α, and IL-1β, in the ZG groups compared with the MTX group. The activity of SOD, CAT, and GPX, as well as the hepatic content of GSH, showed a significant increase in the ZG groups compared with the MTX group. Histopathological improvement in the hepatic tissue of ZG groups compared with the MTX group confirmed all other findings. Conclusions: It is concluded that zingerone can improve hepatic injury induced by MTX in rats regarding the redox system features, inflammation, and histological changes. This can make humans hopeful for using Ginger in the future for attenuating the hepatic side effects of MTX when used chronically.


2005 ◽  
Vol 2 (1) ◽  
pp. 50-54 ◽  
Author(s):  
Iftikharul Haq ◽  
Yenisel Cruz-Almeida ◽  
Edir B. Siqueira ◽  
Michael Norenberg ◽  
Barth A. Green ◽  
...  

Object. Postoperative adhesion- and fibrosis-induced spinal cord tethering is not uncommon and may be associated with delayed clinical sequelae. Multiple dural substitutes have been used in surgery without a full appreciation of the grafts' adverse effects. The authors conducted a comparative animal experimental study to evaluate the degree of chronic inflammatory reactions, adhesions, and fibrosis caused by the use of four dural substitutes—Surgicel, Durasis, DuraGen, and Preclude. Methods. Twenty-six pigs weighing 30 to 40 kg underwent a two-level lumbar laminectomy (a midline durotomy, implantation of a 2-cm dural substitute in the subarachnoid space, and watertight dural closure). After 8 weeks the animals were killed, and two independent neuropathologists blinded to the dural substitute group evaluated several sites along the implants, providing descriptions and quantitative scoring of fibrosis, chronic inflammatory reactions, foreign-body reactions, and spinal cord changes. Kruskal—Wallis one-way analysis of variance for ranks corrected for multiple comparisons was used to examine differences among the materials. Conclusions. The DuraGen dural substitute produced the least amount of inflammation in the subarachnoid space and Preclude generated the most (p < 0.001). Surgicel and DuraGen were completely resorbed on histological sections, but both produced some inflammation, which diminished gradually from the dural implant center. Histological evaluation of the nonresorbed grafts demonstrated that Durasis caused the least degree of inflammatory cell infiltration (p < 0.001). The Preclude dural substitute consistently demonstrated encapsulation and arachnoidal reaction. There was no evidence of implant-related adverse effects on the underlying pia mater and white matter regardless of the substitute type.


2018 ◽  
Vol 19 (8) ◽  
pp. 2274 ◽  
Author(s):  
Xian-Bing Chen ◽  
Zi-Li Wang ◽  
Qing-Yu Yang ◽  
Fang-Yu Zhao ◽  
Xiao-Li Qin ◽  
...  

Spinal cord injury (SCI) is a severe traumatic lesion of central nervous system (CNS) with only a limited number of restorative therapeutic options. Diosgenin glucoside (DG), a major bioactive ingredient of Trillium tschonoskii Max., possesses neuroprotective effects through its antioxidant and anti-apoptotic functions. In this study, we investigated the therapeutic benefit and underlying mechanisms of DG treatment in SCI. We found that in Sprague-Dawley rats with traumatic SCI, the expressions of autophagy marker Light Chain 3 (LC3) and Beclin1 were decreased with concomitant accumulation of autophagy substrate protein p62 and ubiquitinated proteins, indicating an impaired autophagic activity. DG treatment, however, significantly attenuated p62 expression and upregulated the Rheb/mTOR signaling pathway (evidenced as Ras homolog enriched in brain) due to the downregulation of miR-155-3p. We also observed significantly less tissue injury and edema in the DG-treated group, leading to appreciable functional recovery compared to that of the control group. Overall, the observed neuroprotection afforded by DG treatment warrants further investigation on its therapeutic potential in SCI.


2019 ◽  
Vol 44 (3) ◽  
pp. 355-359
Author(s):  
Ronaldo Antonio da Silva ◽  
Isabela Leite Ferraz ◽  
Ricardo Santos Zuza ◽  
Camila Camara ◽  
Mariângela Alencar Marques ◽  
...  

Background and objectivesAs the number of people with tattoos has been increasing, anesthesiologists are more and more faced with the decision to perform a neuraxial blockage through tattooed skin. In this study, we evaluated the possibility of puncture through tattooed skin determines acute inflammatory changes in the meninges and spinal cord and later evolve into adhesive arachnoiditis.MethodForty-two male rabbits were randomized into 3 groups of 14: G1, spinal puncture through non-tattooed skin and saline solution injection; G2, spinal puncture through tattooed skin and saline solution injection, captive for 30 days; G3, spinal puncture through tattooed skin and saline solution injection, captive for 360 days. The animals were anesthetized and ultrasound-guided spinal puncture was performed in the intervertebral spaces between S1 – S2. During the period of captivity, the animals were clinically assessed for sensitivity and motor function. After that, they were sacrificed and the lumbosacral portion of the spinal cord was excised for histological analysis.ResultsNo histological changes were found on group 1. Eleven animals from group two presented with foci of perivascular lymphocytic inflammatory infiltrate in the pia mater and/or arachnoid. In Group 3, eight rabbits presented with inflammatory changes in the meninges, which were associated with thickening and/or adhesion of the pia mater and arachnoid in some cases and five rabbits presented only thickening of pia-mater.ConclusionsSpinal puncture through tattooed skin of rabbits can trigger acute inflammatory changes in the meninges and after a prolonged period of observation evolve into adhesive arachnoiditis.


Author(s):  
Mustafa Salah Hasan ◽  
Ayman Barzan Abdulgafor ◽  
Maher Saber Owain ◽  
Mohammed Ali Hussein ◽  
Qusay Mohammed Aboud ◽  
...  

This study aimed to evaluate the liver, kidney damage caused by S. typhimurium and to estimate the oxidative damage in association with this bacteria. A highly virulent isolates of S. typhimurium were obtained from the department of internal and preventive medicine/ College of Veterinary Medicine/ University of Baghdad. A twenty five local rabbits of both genders with age range (2-4 months) weeks old were used for this study, the rabbits were divided randomly into five groups each group contains 5 rabbits :- group 1: drenched orally with 5 ml of normal saline and consider as control group, group 2: were drenched orally with (5 ml) suspension which contain (5��109 CFU) of Salmonella typhimurium and regarded as infected group, group 3 were drenched orally with (5 ml) suspension which have (5��109 CFU) of Salmonella typhimurium then treated with a single dose of gentamicin alone at 0.05ml/kg (5mg/ml) orally after presence of signs (after 24hrs. post inoculation), group 4 were drenched (5 ml) suspension having (5��109 CFU) of Salmonella typhimurium then treated with a single dose of Ca-EDTA alone at 40mg/kg orally after presence of signs (after 24hrs. post inoculation) and group 5 were drenched (5 ml) suspension that contain (5��109 CFU) of Salmonella typhimurium then treated with a single dose of combined gentamicin at 0.05ml/kg (5mg/ml) orally after presence of signs (after 24hrs. post inoculation) and Ca-EDTA 40mg/kg after presence of signs (after 24hrs. post inoculation).The results of biochemical profile showed a significant increase (p less than 0.05) in ALT, creatinine and urea levels in infected group as compared with control group, while, the treated groups especially group 5 showed a significant improvement in ALT, Urea and creatinine levels which returned to relative normal levels as compared with infected group after 96hrs. post treatment. Also, the results of oxidative stress showed a significant increase in the levels of MDA in G2, G3, G4 and G5 after 48 hrs. post treatment, while the level of GSH showed a significant decrease in the level at 48hrs., both were returned to relative normal levels after 96hrs.post treatment especially in group 5.In conclusion, S. typhimurium can causing liver and kidney damage which is manifested by increase ALT, Urea and Creatinine. Also, MDA and GSH is increased due to salmonellosis.


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