Protective effect of erythropoietin on type II pneumocyte cells after traumatic brain injury in rats

BACKGROUND: The main objective was to evaluate the protective effect of erythropoietin on lung ultrastructure against damage in rats after traumatic brain injury. METHODS: We used forty Wistar-Albino female rats weighing 170-200 gr. The rats were allocated into five groups. The first group was the control and the second was the craniotomy without trauma. The third group was the trauma group. The fourth and fifth groups were erythropoietin (1000 IU/kg) and vehicle (0.4 mL/rat) groups, respectively. A weight-drop method was used for achieving head trauma. Samples were obtained from pulmonary lobes 24-hour post injury. Lipid peroxidation levels were determined and electron microscopic scoring model was used to reveal the ultrastructural changes. RESULTS: Ultrastructural evaluation revealed pathologic changes in the trauma group compared with the control group (p < 0.05). Lipid peroxidation levels were found to be higher in the trauma group (p < 0.05). Erythropoietin significantly reduced both the ultrastructural pathologic changes and the lipid peroxidation levels in the treatment group (p < 0.05). CONCLUSIONS: Erythropoietin protects the ultrastructure of pneumocyte type II cells against damage after traumatic brain injury.     

Ultrastructural Changes of Rat Cardiac Myocytes in a Time-Dependent Manner After Traumatic Brain Injury

We suggest an ultrastructural scoring system to evaluate the degree of damage in a time-dependent manner in cardiac myocytes after traumatic brain injury (TBI). Forty Wistar-Albino female rats weighing 170-200 g were randomly allocated into five groups. Group 1 was the control and Group 2 was the sham-operated group. Group 3, Group 4 and Group 5 were trauma groups. Weight-drop technique was used for achieving TBI. Lipid peroxidation was estimated by thiobarbituric acid test. An electron microscopic scoring model was used to grade the subcellular changes. Results of heart injury score (HIS) showed that the 24-h trauma group had statistically significant levels in nuclear damage compared with the other groups (p < 0.05). Sarcoplasmic reticulum and mitochondria scores of all trauma groups were significantly different from the control and sham groups (p < 0.05). The results showed that lipid per oxidation levels were statistically significant different between the control and all trauma groups (p < 0.05). The electron microscopic scoring model worked well in depicting the traumatic changes, which were supported by lipid peroxidation levels. Traumatic brain injury produced obvious gradual damage on the ultrastructure of the cardiac myocytes and this damage was more significant in the 24-h trauma group.     

Ultrastructural changes in tracheobronchial epithelia following experimental traumatic brain injury in rats: Protective effect of erythropoietin

BACKGROUND: We aimed to demonstrate the time dependent ultrastructural changes in tracheobronchial epithelia after traumatic brain injury. And also, protective effect of erythropoietin was demonstrated. METHODS: We used 56 Wistar-Albino female rats weighing 170 to 200 g. The rats were allocated into 7 groups. First group was the control. The second underwent craniotomy without trauma. The third, fourth, and fifth groups were respectively 2-, 8-, and 24-hour trauma groups. The sixth and seventh groups were respectively treatment (erythropoietin, 1,000 IU/kg) and vehicle (0, 4 ml/rat) groups. Weight-drop method was used for achieving head trauma. Samples were obtained from both trachea and main bronchi. Modified electron microscopic scoring model was used to reveal the ultrastructural changes in both trauma and treatment groups. RESULTS: There was no statistical difference between control and sham groups (p >0.05). Scores of all trauma groups were significantly different from the controls (p <0.05). Trauma produced obvious gradual damage on ultrastructure of the tracheobronchial epithelia. Erythropoietin decreased tracheobronchial scores after traumatic brain injury in significant levels. Erythropoietin attenuated ultrastructural scores for each organelle in significant levels (p <0.05 for each organelle). CONCLUSIONS: The data suggested that ultrastructural damage is obvious at 2 hours deteriorating with time. Erythropoietin protects epithelia against damage after traumatic brain injury. Pharmaceutical lung preservation may help gaining efficacious donor lungs in brain death. But, further time dependent experiments are needed to determine the liability of the donor lung after traumatic brain injury. This fact is to be known for achieving higher graft survival rates.     

Experimental Traumatic Cerebral Contusion: Morphological Study of Brain Microvessels and Characterization of the Oedema

Summary Several experimental brain oedema models are currently available, but most of them are very different from what happens in clinical practice. As it is simple and seems to replicate the range of injuries seen in man we decided to evaluate Marmarou's model of head injury in order to test physiopathogenic and therapeutic hypotheses. Three groups of Wistar rats weighing 360–400 gr, anaesthetized with sodium pentobarbitone and breathing spontaneously, without tracheal intubation, were studied. In the first group six animals were killed two hours after injury and the brain's water content compared with that of nine controls. In another group Evans blue (100 mg/kg) was injected one hour before trauma and dye's extraction ratio determined at various times after injury: five animals at 15 minutes, six at 30 minutes, five at 60 minutes and nine at 120 minutes. A total of twenty-eight animals served as controls. In the last group morphological studies with light and electron microscopy were performed in the traumatized brain tissue from rats killed 5 and 120 minutes after injury and in brain tissue from control rats. Results showed that Marmarou's brain trauma model induced perivascular brain oedema, already visible at the ultrastructural level 5 minutes after the injury. Endothelial cells themselves were “oedematiated”, rich in pinocytotic vesicles and membrane blebs, and presented intact tight junctions. Two hours after trauma the perivascular oedema was more marked. At this time the brain water content was significantly higher than that in controls. Evans blue extraction ratio increased linearly with time, being significantly higher than in controls 120 minutes after injury. We conclude that Marmarou's model is a suitable model for the study of brain oedema induced by trauma, and that this oedema, assessed by three different methodologies, was statistically significant two hours after injury.     

Ultrastructural changes following overhydration with irrigating fluids

We studied ultrastructural alterations caused by intravenous infusion of 150 ml/kg of irrigating fluid containing mannitol and/or sorbitol in 15 rabbits. The osmolality of the solutions varied between 165 and 350 mosmol/kg. Specimens for electron microscopic examination were obtained from the kidney, brain and lung. Regardless of the choice of solute, the hypo-osmotic solutions caused damage to kidney and brain tissue by inducing marked interstitial and cellular oedema. No such changes were observed after administration of isosmotic irrigating fluid. We conclude that ultrastructural changes following overhydration with irrigating fluid vary with the osmolality of the solution but not with the choice of solute. Moreover, the consistent absence of tissue damage in the lungs suggests that the lung is not a primary target organ for the “TUR syndrome”.     

Effect of growth hormone on brain oedema caused by a cryogenic brain injury model in rats

Although growth hormone (GH) is a potential agent to counteract the catabolic response to general and head injuries, the complications of GH treatment have been little studied. To evaluate the safety of GH in head trauma patients, it was investigated whether GH affects brain oedema caused by brain injury, using a rat freeze-injury model. Male Wistar rats (n = 28) were divided into four groups according to the substance injected (GH vs. saline) and whether brain was injured or not. GH (0.8IU/kg) or saline was injected subcutaneously every 24 hours. In the injury groups, immediately before the first injection of GH, an aluminum rod cooled to-50 C was placed on the right parietal region for 4 minutes, under anaesthesia. At 96 hours after the insult, brain and skeletal muscle were excised and their water content was measured, by drying. Freeze injury of the brain caused an increase in water content in skeletal muscle. GH injection augmented this oedema in skeletal muscle. Freeze injury of the brain also caused an increase in water content in the injured and non-injured hemispheres of brain and cerebellum. GH administration did not exacerbate brain oedema caused by brain injury in this model.     

Effects of trapidil on ATPase, lipid peroxidation, and correlation with ultrastructure in experimental spinal cord injury

The present study was performed to investigate the effect of trapidil on ischemic damage of cells after spinal cord injury. The injury was produced by extradural clip compression of the exposed spinal cord in rats according to Rivlin and Tator. The ten rats in group 1 were used to determine normal findings without any surgery or medication. On the 15 rats in group 2, only six-level laminectomy was performed to determine the influence of the total laminectomy on the biochemical factors measured and the light and ultrastructural findings. The 15 rats each in groups 3 and 4 were used as trauma and trapidil (40 mg/kg) treatment groups, respectively. The injury actually produced a significant decrease in Na⁺–K⁺/Mg⁺² ATPase activity of the injured segments as early as 10 min after trauma. Trapidil attenuated Na⁺–K⁺/Mg⁺² ATPase inactivation in the traumatized rats for 120 min after treatment (P<0.05) and significantly reduced the malone dialdehyde content below that in the traumatized group at all determined times (P<0.05). Light and electron microscopic findings supported the biochemical results. Received: 17 April 2000 / Accepted: 27 September 2000     

Influence of Aging on Blood-Brain Barrier Permeability and Free Radical Formation Following Experimental Brain Cold Injury

Summary.  The aim of this study is to investigate the effects of experimental cold brain injury on blood-brain barrier integrity, on brain oedema formation, and on lipid peroxidation and to compare the results between the aged and young rats. Cold brain injury was used to create a standard model of brain trauma in old and young rats. Disruption of the blood-brain barrier was analyzed by Evans blue method. The values of cerebral water content were calculated by using the fresh and dry weights of the cerebral hemispheres. Lipid peroxidation was assessed by measuring the tissue content of malonyl dialdehyde.  Blood-brain barrier was destroyed significantly in young and old rats, but it was more severe in old rats. Accordingly, cerebral water content was increased in both groups, however this increase was significantly more prominent in old rats. No significant difference was found on malonyl dialdehyde levels between young and old rats.  The blood-brain barrier was more easily disrupted in old rats, and this was supposed to be the basic event causing more secondary damage.     

The effects of pirfenidone on ischaemia–reperfusion injury in testicular torsion-induced rat model

The aim of this study was to analyse the effect of pirfenidone against ischaemia–reperfusion injury occurring after detorsion in rats with induced testicular torsion model. Group 1 was assigned as the control group. Group 2 first had testis torsion performed, and then, testicular detorsion was performed. Group 3 had similar procedures to the rats in Group 2. Rats in Group 3 additionally had 325 mg/kg pirfenidone administered immediately after ischaemia. The blood samples were analysed spectrophotometrically. To determine the intensity of tissue injury, haemorrhage, oedema and congestion levels were evaluated with direct microscopic investigation of testis. Seminiferous tubule architecture, spermatogenesis processes and germ cell maturation were graded by Johnsen and Cosentino scoring systems. In Group 3, superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities increased compared with Group 2 (p:.03 and p:.049 respectively). Additionally, the mean malondialdehyde (MDA) value was higher in Group 2 compared with the other groups (p:.001). Histopathological investigation of rats in Group 3 identified positive changes in haemorrhage, oedema and congestion levels compared with Group 2 (p:.031, p:.048, p:.044 respectively). Similarly, Johnsen and Cosentino scores were positively affected in Group 3 (p:.033, p:.032 respectively). Pirfenidone is protective against testicular oxidative damage.     

Antioxidant actions and early ultrastructural findings of thiopental and propofol in experimental spinal cord injury

Thiopental and propofol are effective antioxidant agents. The current study was undertaken to examine the neuroprotective effects of a single intraperitoneal dose of thiopental and propofol. Effects of the drugs were evaluated by lipid peroxidation and ultrastructural findings. Fifty male Wistar rats were divided into five groups. Group 1 was the control group. Rats underwent laminectomy only, and nontraumatized spinal cord samples were obtained 1 hour after surgical intervention. All other rats sustained a 50-g/cm contusion injury by the weight drop technique. Group 2 rats underwent spinal cord injury alone, group 3 rats received 1 mL intralipid solution intraperitoneally immediately after trauma as the vehicle group, group 4 rats received a 15-mg/kg single dose of thiopental, and group 5 rats received a 40-mg/kg single dose of propofol intraperitoneally following the trauma. Samples from groups 2, 3, 4, and 5 were obtained 1 hour after injury. Lipid peroxidation was determined by measuring the concentration of malondialdehyde in the spinal cord tissue. The ultrastructure of the spinal cord was determined by electron microscopy. The contusion injury was associated with a rise in lipid peroxidation. Compared with the trauma group there was significant attenuation in lipid peroxidation of groups 4 and 5. Ultrastructural findings showed that the rats of group 4 sustained minor damage after spinal cord injury, but there was more evident damage in group 5 rats. These results indicate that thiopental decreases lipid peroxidation and improves ultrastructure, whereas propofol decreases lipid peroxidation without improving ultrastructure 1 hour after spinal cord injury in rats.     

氯胺酮对脑外伤大鼠脑组织水通道蛋白-4表达的影响

目的 观察氯胺酮对脑外伤大鼠脑组织水通道蛋白-4（AQP-4）表达的影响，探讨氯胺酮减轻脑外伤的作用机制。方法 健康雄性Wistar大鼠152只，随机分为对照组和治疗组，每组76只。采用自由落体致脑外伤动物模型，治疗组大鼠伤后1 h腹腔注射氯胺酮120 mg／kg，对照组相同时间给予容量生理盐水。每组分别在伤后6、12、24、48和72h随机处死15只大鼠，每个时点的5只大鼠用于测定脑组织含水量，每个时点的其余10只大鼠经心脏灌注后取脑组织，观察脑组织病理学改变及神经元凋亡情况，测定AQP-4表达。结果 与对照组比较，治疗组大鼠伤后各时间点脑含水量、AQP-4表达及神经元凋亡计数均降低（P〈0．05或0．01），脑组织病理学改变明显减轻。结论 氯胺酮120 mg／kg通过抑制脑外伤大鼠脑组织AQP-4的表达，减少了神经元的凋亡，从而减轻脑损伤。     

Effects of magnesium sulfate on traumatic brain edema in rats

svarietyofneuroprotectiveagentshavebeensynthesized .However ,besidessomeagentspresentlybeingevaluatedinclinicaltrails ,mostofthesecompoundshavelimitedclinicalusebecauseofneurotoxicityandbehavioralsideeffects .Recently ,severalstudiesdemonstratedthattraumaticinjurytothebraincausesadecreaseinmagnesiumconcentrationcorrelatedwithinjuryseverity .1Sincethen ,moreandmoreattentionhasbeen paidtoMgSO4 foritsneuroprotectiveeffects .Magnesiumsulfatehasbeenwidelyusedinclinicalpracticeforalmost 10 0 years.…     

Establishment of a mechanical injury model of rat hippocampal neurons in vitro

Objective： To establish a simple, reproducible, and practical mechanical injury model of hippocampal neurons of Sprague-Dawley rats in vitro. Methods ： Hippocampal neurons isolated from 1-2-day old rats were cultured in vitro. Mild, moderate and severe mechanical injuries were delivered to the neurons by syringe needle tearing, respectively. The control neurons were treated identically with the exception of trauma. Cell damage was assessed by measuring the Propidium Iodide （PI） uptaking at different time points （0.5, 1, 6, 12 and 24 hours） after injury. The concentration of neuron specific enolase was also measured at some time points. Results ： Pathological examination showed that degeneration, degradation and necrosis occurred in the injured cultured neurons. Compared with the control group, the ratio of PI-positive cells in the injured groups increased significantly after 30 minutes of injury （P 〈 0.05）. More severe the damage was, more PI-positive neurons were detected. Compared with the control group, the concentration of neuron specific enolase in the injured culture increased significantly after 1 hour of injury （ P 〈 0.05）. Conclusions： The established model of hippocampal neuron injury in vitro can be repeated easily and can simulate the damage mechanism of traumatic brain injury, which can be used in the future research of traumatic brain injury.     

Effects of magnesium sulfate on traumatic brain edema in ats

OBJECTIVE: To investigate the effects of magnesium sulfate on traumatic brain edema and explore its possible mechanism. METHODS: Forty-eight Sprague-Dawley (SD) rats were randomly divided into three groups: Control, Trauma and Treatment groups. In Treatment group, magnesium sulfate was intraperitoneally administered immediately after the induction of brain trauma. At 24 h after trauma, total tissue water content and Na(+), K(+), Ca(2+), Mg(2+) contents were measured. Permeability of blood-brain barrier (BBB) was assessed quantitatively by Evans Blue (EB) dye technique. The pathological changes were also studied. RESULTS: Water, Na(+), Ca(2+) and EB contents in Treatment group were significantly lower than those in Trauma group (P<0.05). Results of light microscopy and electron microscopy confirmed that magnesium sulfate can attenuate traumatic brain injury and relieve BBB injury. CONCLUSIONS: Treatment with MgSO4 in the early stage can attenuate traumatic brain edema and prevent BBB injury.     

预防使用大剂量甲基强的松龙对大鼠急性脊髓损伤的神经保护作用

目的研究预防使用大剂量甲基强的松龙对急性脊髓损伤大鼠的神经功能保护作用方法采用Allen重物打击模型，动物随机分为三组：对照组；脊髓损伤组；预防使用大剂量甲基强的松龙组。分别在脊髓损伤后24h、72h进行神经功能评分(Tarlov评分障碍率、Molt斜板功能障碍率)、脊髓病理形态学及超微结构观察、神经中丝(NF)及胶质纤维酸性蛋白(GFAP)观察、结果预防使用大剂量MP可明显改善损伤脊髓的病理形态及超微结构；脊髓损伤后72h大鼠神经功能评分明显提高；显著提高NF的表达、抑制GFAP的表达．结论预防使用大剂量甲基强的松龙对大鼠急性脊髓损伤有神经保护作用     

Ultrastructural study of severe testicular damage following acute scrotal thermal injury

AIM: The scrotum provides an appropriate environment for the testicles that is essential for spermatogenesis. The aim of this study was to investigate the severity of ultrastructural damage to the testicles after acute thermal injury. MATERIALS AND METHODS: Twenty male Sprague-Dawley rats weighing 250+/-20g were randomly divided into four groups of five rats each (10 testicles in each group). In the sham group, animals were anesthetized, and both testicles were removed through a lower transverse abdominal incision. For animals in the burn induction group, a container filled with boiling water was used. For the T30 group, the scrota were in contact with steam from the boiling water for 30s. This procedure was the same for the other two groups: the T60 group (60s of steam contact) and the T90 group (90s of steam contact). Skin biopsies of scrota and excisional biopsies of both testicles were taken 1h after burn. Specimens were prepared for immunohistochemical and transmission electron microscopic examinations. Apoptotic and proliferative activity in the testicles and epidermal and dermal damage to the skin were measured. RESULTS: Histopathological examination indicated increasing epidermal and dermal damage to the skin in parallel with the length of contact between the scrota and the steam. Increased apoptotic activity was observed in animals after 30s, testicular degeneration began at 60s, and a diffuse degeneration was observed at 90s with a high rate of apoptosis (P<.005). CONCLUSION: Our findings demonstrate that thermal trauma to scrotal skin directly affects proliferation, the occurrence of apoptotic and necrotic cell death of spermatogenic seria, Sertolli and Leydig cells in testicles. Attempts to protect the testicles from severe thermal damage are essential, when the scrotal skin is affected by the burn.     

Ultrastructural and functional characteristics of blast injury-induced neurotrauma

OBJECTIVE: The present study investigates whether whole-body or local (chest) exposure to blast overpressure can induce ultrastructural, biochemical, and cognitive impairments in the brain. METHODS: Male Wistar rats were trained for an active avoidance task for 6 days. On day 6, rats that had acquired the avoidance response were subjected to whole-body blast injury (WBBI), generated by large-scale shock tube (n = 40); or local (chest) blast injury (LBI), induced by blast overpressure focused on the right middle thoracic region and generated by small-scale shock tube (n = 40) while the heads of animals were protected. At the completion of cognitive testing, rats were killed at 3 hours, 24 hours, and 5 days after injury. Ultrastructural changes in the hippocampus were analyzed electron microscopically. Parameters of oxidative stress (malondialdehyde and superoxide anion generation) and antioxidant enzyme defense (superoxide dismutase and glutathione peroxidase activity) were measured in the hippocampus to assess biochemical changes in the brain after blast. RESULTS: Ultrastructural findings in animals subjected to WBBI or LBI demonstrated swellings of neurons, glial reaction, and myelin debris in the hippocampus. All rats revealed significant deficits in performance of the active avoidance task 3 hours after injury, but deficits persisted up to day 5 after injury only in rats subjected to WBBI. Oxidative stress development and altered antioxidant enzyme defense was observed in animals in both groups. Cognitive impairment and biochemical changes in the hippocampus were significantly correlated with blast injury severity in both WBBI and LBI groups. CONCLUSION: These results confirm that exposure to blast overpressure induces ultrastructural and biochemical impairments in the brain hippocampus, with associated development of cognitive deficits.     

Vibration exposure and peripheral nerve fiber damage

The hind leg of adult rats was exposed to vibrations (82 Hz; amplitude peak-to-peak 0.21 mm) for 4 hours during 5 consecutive days. Light and electron microscopic examination of the plantar and sciatic nerves were done immediately after the exposure period or after a 2- or 4-week recovery period. Light microscopic examination did not reveal any distinct signs of injury. However, ultrastructurally unmyelinated fibers in the plantar nerves showed distinct changes, with deranged axoplasmic structure and/or accumulation of smooth endoplasmatic reticulum. These changes were to a large extent reversible in 2 weeks and appeared normalized after a 4-week recovery period. No ultrastructural changes could be observed in the sciatic nerve. However, when the sciatic nerve was crushed after 5 days of vibration exposure, axonal outgrowth was increased 23% as compared with controls. These findings confirm that vibration induces nerve fiber damage, in this experimental model expressed as a "conditioning effect" contributing to increased regeneration potential of the corresponding neurones.     

慢性颅内静脉压增高状态下硬脑膜血管内皮生长因子的表达与超微结构变化

目的探讨慢性颅内静脉压增高状态下硬脑膜血管内皮生长因子(VEGF)表达及其与血管超微结构改变的关系。方法选Wistar雄性大鼠24只(实验组12只;对照组12只),右侧颈总动脉和颈外静脉端端吻合,同时结扎上矢状窦,建立慢性颅内静脉压增高的动物模型;90d后采用免疫组织化学方法检测硬脑膜血管内皮细胞中VEGF的表达和血管生成情况,透射电镜观察血管壁超微结构变化。结果B组的硬脑膜血管中VEGF仅呈微弱表达,其吸光度值(A)为2.12±0.59,A组硬脑膜中血管内皮细胞VEGF表达吸光度值(A)为8.66±1.75,两者相比A组微血管生成数量显著增高(P<0.05);微血管密度(×200倍计数)B组为(2.25±0.23/0.74)mm2,A组为(8.66±1.75/0.74)mm2,两者相比A组微血管生成密度显著增高(P<0.05)。而且A组血管内皮细胞的间隙增宽,平滑肌数量减少,胶原组织增多。结论慢性静脉压增高状态下硬脑膜血管中VEGF表达升高,可能与血管生成及血管的超微结构改变有重要关系     

Behavioural and Morphological Outcome of Mild Cortical Contusion Trauma of the Rat Brain: Influence of NMDA-Receptor Blockade

Summary  The authors studied the effect of a mild cortical contusion to the rat brain on behavioural and morphological outcome and the influence of NMDA-receptor blockade (MK-801, 0.5 mg/kg i.v. 30 min prior to trauma). Spontaneous motor activity was assessed 16–18 days post trauma. Saline treated traumatised rats showed a significant (p<0.01) hyperactive behaviour compared to animals without injury. MK-801 treated rats performed significantly better than the saline treated animals (p<0.05). For histopathological evaluation hippocampal hilar neurons were counted, cortical thickness under the impact was measured and microtubule-associated protein 2 (MAP2) immunoreactivity in the dentate hilus was quantified 1, 3 and 21 days post trauma. In traumatised rats scattered loss of nerve cells, oedema and minute haemorrhages were present at the site of the impact one and three days after injury. At day 21 there was a significant reduction of cortical thickness at the site of impact. One day after trauma there was a bilateral, significant loss of neurons and MAP2 immunostaining in the dentate hilus of the hippocampus. MK-801 pretreated rats showed similar morphological changes. The disturbed spontaneous motor behaviour may be caused by hippocampal damage and a reduction of somatosensory cortical neurons. NMDA-receptor blockade improved the outcome assessed by the functional tests but failed to influence the morphological changes, suggesting that this behavioural test is a more sensitive indicator of outcome after mild traumatic brain injury (TBI).