Effects of multi-dose methylprednisolone sodium succinate administration on injured cat spinal cord neurofilament degradation and energy metabolism

Thirty minutes after experimental spinal cord contusion (500 gm-cm) injury, cats were treated with an initial intravenous dose of either vehicle (V) or 30 mg/kg of Solu-Medrol sterile powder (methylprednisolone sodium succinate; MPSS). Two hours later, cats received a second intravenous injection of either V or 15 mg/kg MPSS, giving three treatment groups: V/V; MPSS/V; MPSS/MPSS. At 4 1/2 hours following injury of the cat lumbar spinal cord, the gray and white matter neurofilament protein content was reduced by over 70% within the injured segment of V/V-treated animals. The three major cat spinal cord neurofilament protein subunits of 200,000, 152,000, and 76,000 daltons were reduced in parallel by the injury. Treatment of cats with a single 30-mg/kg dose of MPSS (MPSS/V) provided a clear, although not significant, protection against neurofilament degradation compared with V/V-treated cats when measured at 4 1/2 hours after injury. The lactic acid content of the injured spinal cord segment at 4 1/2 hours after injury was significantly elevated in both V/V- and MPSS/V-treated cats, while the adenosine triphosphate (ATP) content, total adenylates, and energy charge were significantly reduced. The administration of a second intravenous 15-mg/kg dose of MPSS 2 hours after the initial 30-mg/kg dose (MPSS/MPSS) provided complete (p less than 0.01) preservation of neurofilaments within the injured spinal cord segment measured at 4 1/2 hours after injury. The levels of lactate, ATP, total adenylates, and tissue energy charge in MPSS/MPSS-treated cats were not different from those of uninjured spinal cords following laminectomy. The (Na+ + K+)-ATPase activity in the injured spinal segment was enhanced, although highly variable, in MPSS/V-treated animals. On the other hand, spinal cord enzyme activity was significantly and consistently elevated in the MPSS/MPSS-treated group. The results demonstrate that a 30-mg/kg dose of MPSS followed at 2 hours by a 15-mg/kg dose provides significantly better protection against injury-induced ischemia and Ca++-dependent neurofilament degradation than a single 30-mg/kg dose. These findings are in agreement with the spinal cord tissue pharmacokinetics and time-action characteristics of methylprednisolone observed in earlier studies.     

Anaphylaxis following administration of intravenous methylprednisolone sodium succinate in a renal transplant recipient

Methylprednisolone sodium succinate (MPS) is widely used in the management of renal transplantation. Of interest is the rare occurrence of anaphylaxis and anaphylactoid reaction to MPS. We report on a patient who developed anaphylaxis following the intravenous administration of MPS during a renal transplant operation. Intracutaneous testing was carried out with MPS and a strong positive reaction was observed. Histamine and tryptase concentrations were high after the anaphylactic reaction. Including the present case, there have been 13 reports of anaphylactic or anaphylactoid reactions to MPS, occurring in renal transplant recipients. Clinicians should be aware of the potential risk of MPS administration. If transplant patients undergo skin testing against MPS prior to transplant, they may benefit from an alternative medication with other corticosteroids. To use MPS without severe adverse reactions, lower administration rates and dosages are very important.     

Evaluation of an intensive methylprednisolone sodium succinate dosing regimen in experimental spinal cord injury

Beginning 30 minutes after compression trauma of the upper lumbar (L-2) spinal cord, cats were treated with either a high-dose regimen of methylprednisolone (MP) administered as the sodium salt of the 21-succinate ester (Solu-Medrol sterile powder) or the MP vehicle. Animals were randomly assigned to either treatment group (10 cats per group), and all personnel were blind as to which animals received vehicle or drug. The intensive 48-hour dosing regimen was designed to maintain therapeutic tissue levels of MP and consisted of an initial 30 mg/kg intravenous bolus of MP; 2 and 6 hours later additional 15 mg/kg MP doses were administered by intravenous bolus. Immediately following the bolus given at 6 hours, a continuous MP infusion of 2.5 mg/kg/hr was started. The infusion was stopped abruptly at 48 hours with no dose tapering. Animals in the vehicle group received an equivalent volume of MP vehicle. The total MP dose administered over 48 hours was 165 mg/kg. Animals were evaluated weekly for neurological recovery based upon a 12-point functional scale which assessed general mobility, running, and stair-climbing. Mean recovery scores at 1 month after injury (+/- standard error of the mean) were: vehicle group (seven cats) 3.7 +/- 0.9, and MP group (10 cats) 8.7 +/- 0.2; (p less than 0.001). Histological evaluation of the spinal cords revealed a strong negative correlation between neurological recovery and size of the spinal cord cavity at 1 month (r = -0.88). Three of 10 animals in the vehicle group became ill and had to be dropped from the study, whereas all of the 10 MP-treated animals survived in excellent health. The results demonstrate the therapeutic effectiveness and low incidence of side effects associated with an intensive MP dose regimen for treatment of experimental spinal cord injury.     

Early complications of high-dose methylprednisolone sodium succinate treatment in the follow-up of acute cervical spinal cord injury

STUDY DESIGN: A prospective, randomized, and double-blind study comparing high-dose methylprednisolone sodium succinate (MPSS) with placebo, in the treatment of patients with acute cervical spinal cord injury. OBJECTIVES: To evaluate the complications of high-dose MPSS in patients with acute cervical spinal cord injury when administered within 8 hours of injury. SUMMARY OF BACKGROUND DATA: High-dose therapy with MPSS has been demonstrated to improve the recovery of motor function in patients with acute cervical spinal cord injury. However, little is known about the follow-up complications. METHODS: Forty-six patients, 42 men and 4 women (mean age, 60.6 years; range, 18-84), were included in the study: 23 in the MPSS group and 23 in the placebo group. They were treated without surgery for spinal cord injury in the cervical spine, and were enrolled in the trial if a diagnosis had been made and treatment had begun within 8 hours. Complications of high-dose therapy with MPSS were compared with placebo treatment throughout the study period and up to 2 months after injury. RESULTS: The MPSS group had 13 patients (56.5%) with complications, whereas the placebo group had 8 (34.8%). The difference between the two groups was not statistically significant (P = 0.139). There were eight instances of pulmonary complication with MPSS (34.8%) and one instance (4.34%) with placebo (P = 0.009). There were four instances of gastrointestinal complication (17.4%) with MPSS and none with placebo (P = 0.036). Pulmonary (complications were more prevalent in patients aged more than 60 years (P = 0.029). CONCLUSION: Aged patients with cervical spinal injury may be more likely to have pulmonary side effects (P = 0.029) after high-dose therapy with MPSS and thus deserve special care.     

Lactate and pyruvate metabolism in injured cat spinal cord before and after a single large intravenous dose of methylprednisolone

The lactate content and the lactate/pyruvate ratio of the acutely traumatized cat spinal cord have been studied and were found to rise rapidly following a 400 gm-cm injury. Lactate levels rose nearly twofold within 5 minutes after injury, peaked at 2 hours after injury, and remained significantly elevated for at least 8 hours compared to an adjacent uninjured segment of traumatized cord. Pyruvate levels, on the other hand, fell acutely in the injured section of cord during the 1st hour after injury then rose slowly over an 8-hour period. The changes in tissue lactate and pyruvate metabolism in the spinal cord following injury are consistent with a marked injury-induced reduction in blood flow. The elevation in lactate and the fall in pyruvate levels observed at 1 hour after injury were completely prevented by the intravenous administration of a single 30-mg/kg dose of methylprednisolone sodium succinate at 30 minutes after injury. Lower or higher doses of methylprednisolone were far less effective. The effects of the 30-mg/kg dose of methylprednisolone on tissue lactate content were associated with high tissue levels of the glucocorticoid and were short-lived, paralleling the accumulation and elimination pattern of steroid from the injured tissue. The results suggest that, in addition to other reported beneficial actions of large intravenous doses (30 mg/kg) of methylprednisolone on the injured cord, the glucocorticoid may also improve blood flow to the injured segment as has been suggested by others. The use of high glucocorticoid doses, early therapy initiation, and rigorous maintenance dosing is discussed.     

Histologic characterization of acute spinal cord injury treated with intravenous methylprednisolone

OBJECTIVE: Many substances have been investigated for attenuation of spinal cord injury after acute trauma; however, pharmacologically only steroid administration has shown clinical benefits. This study attempts to characterize local spinal cord histologic response to human dose equivalent (HDE) intravenous methylprednisolone (MP) administration in a rodent model of acute spinal cord injury. DESIGN: Forty-eight Sprague-Dawley rats were divided equally into control and experimental groups. Each group was subdivided into eight sets of three animals each, according to postinjury intervals. Paraplegia after lower thoracic laminectomy was achieved using a standardized weight drop technique. INTERVENTION: Within one hour, experimental animals were treated with HDE MP followed by 23-hour continuous infusion of HDE MP. Spinal cords were harvested at variable intervals postinjury and prepared for histologic/immunohistochemistry examination. MAIN OUTCOME MEASUREMENTS: Edema, necrosis, and glial fibrillary acidic protein (GFAP) positivity in the specimens from treated/control groups were graded by microscopy and immunohistochemistry staining and compared in a blinded manner by a qualified neuropathologist and senior authors. RESULTS: Minimal differences were observed between control and MP-treated animals at zero and four hours. At eight hours, increased white matter and medullary edema was evident in control versus MP-treated rats. This trend continued through twelve, sixteen, twenty-four, forty-eight, and seventy-two hours. No difference was observed in the astrocytic response to injury by GFAP immunohistochemistry between the groups. CONCLUSIONS: Histologically, MP reduces the development of severe edema and preserves spinal cord architecture adjacent to the site of injury. In contrast, MP does not alter the development of spinal cord necrosis or astrocytic response at the zone of injury.     

Effects of a single large dose of methylprednisolone sodium succinate on experimental posttraumatic spinal cord ischemia. Dose-response and time-action analysis

The ability of a single large intravenous dose of methylprednisolone sodium succinate (MPSS: 15, 30, or 60 mg/kg) to modify the evolution of lumbar spinal cord ischemia in cats undergoing a contusion injury of 500 gm-cm is examined. Repeated measurements of spinal cord blood flow (SCBF) in the dorsolateral funiculus were made via the hydrogen clearance technique before and for 4 to 5 hours after injury. The mean preinjury SCBF for all animals was 12.29 +/- 0.77 ml/100 gm/min. Following injury, SCBF began to decrease progressively in vehicle-treated animals to a level of 7.71 ml/100 gm/min, a fall of 37.3%. In contrast, cats that received a 30-mg/kg intravenous dose of MPSS at 30 minutes after injury maintained SCBF within normal limits (p less than 0.05 at 3 and 4 hours after contusion). A 15-mg/kg MPSS dose was less effective at preventing posttraumatic white matter ischemia, and a 60-mg/kg dose was essentially ineffective. It was determined that the 30-mg/kg MPSS dose was optimal for supporting SCBF when the drug was given at 30 minutes after spinal trauma, and a second series of experiments was carried out to examine the ability of this dose, when given at longer latencies, to improve decreased flow. Methylprednisolone given at 1 1/2 hours after injury in four cats produced a slight (12.7%) but transient improvement in SCBF, and when administered at 4 1/2 hours in another three animals was totally ineffective. These results show that MPSS in a 30-mg/kg dose can prevent posttraumatic spinal cord ischemia. However, it would appear that the ability of the steroid to reverse the ischemia once it has developed is limited, and probably lost, within a few hours of onset. This further suggests that the ischemic process is irreversible and underscores the need for early treatment with a large MPSS dose in order to prevent full development of ischemia and to promote neurological recovery.     

脊髓损伤后急性期甲基强的松龙干预对脊髓神经细胞凋亡的影响

目的:观察脊髓损伤后即刻甲基强的松龙干预治疗对脊髓神经细胞凋亡的影响,探讨该药物促进脊髓神经功能修复的机制。方法:采用改良Allen′s法建立脊髓损伤(SCI)兔动物模型,实验动物随机分为假手术组(S组)36只,单纯损伤组(C组)与MP治疗组(T组)各36只,分别于损伤后8h、24h、72h、7d、14d和28d时随机取6只动物灌注固定取材,HE染色观察损伤区脊髓组织的病理改变,TUNEL法检测各组脊髓标本细胞凋亡情况;分别于损伤后1d、3d、7d、14d及28d观察各组动物运动神经功能情况,包括Rivlin斜板试验和BBB评分。结果:术后C组和T组斜板试验临界角度值和BBB评分值随时间点延长均逐渐升高,损伤7d及之后各时间点,T组均高于C组,但小于S组(P<0.05)。HE染色S组脊髓组织在各时间点未见明显异常;T组及C组损伤后8h、24h及72h时脊髓组织结构紊乱,可见不同程度出血、神经细胞水肿、坏死,灰质中空泡形成,炎症细胞浸润,两组无明显区别;损伤后7d、14d及28d,T组脊髓组织较C组恢复较好,整体损伤程度轻,血肿逐渐吸收,空泡减少,灰质和白质坏死吸收并胶原纤维组织增生,胶质细胞减少,可见较多神经细胞。TUNEL法检测凋亡细胞,S组未发现阳性细胞,C组及T组在损伤后8h可见阳性细胞,24h达到高峰,3d时仍较多,术后7d渐渐减少,14d及28d时阳性细胞数明显降低。两组对比,在损伤后8h、24h、3d及7d四个时间点,T组阳性细胞明显少于C组(P<0.05),14d及28d时两组比较无统计学意义(P>0.05)。结论:MP在脊髓损伤急性期干预治疗,有利于损伤的脊髓神经功能恢复,可能通过抗细胞凋亡机制产生作用。     

Topical cardiac hypothermia: the effect of methylprednisolone sodium succinate

We evaluated the effects of methylprednisolone sodium succinate (MPSS) on 60 minutes of myocardial ischemia during profound (5 degrees C) topical cardiac hypothermia (ice chips) in a canine right heart bypass preparation. The ventricular function curve shifted to the right and downward, but not significantly, after ischemia, and stroke work declined significantly for both control and treated dogs. Contractility (rate of rise of left ventricular pressure and maximum velocity of the contractile element) declined for both groups but not significantly. Total coronary flow, oxygen consumption, and metabolism of lactate and pyruvate were not different for control and treated dogs. Ultrastructure of the outer and inner myocardium did not demonstrate benefit from MPSS. Intracellular and extracellular edema of moderate severity was slightly worse in the subendocardium, and reversible mitochondrial injury of a mild to moderate degreee was symmetrically present. Ice-related injury was not noted. We were unable to deomonstrate that pretreatment with MPSS favorably alters cardiodynamics or ultrastructure after 60 minutes of profound topical cardiac hypothermia.     

复方丹参注射液和甲基强的松龙治疗大鼠急性脊髓损伤的作用及机制

目的探讨联合应用复方丹参注射液和甲基强的松龙(MP)对大鼠急性脊髓损伤的治疗作用和意义.方法采用Allen法将64只SD大鼠制成脊髓中度损伤模型,随机分为4组,每组16只,分别给予复方丹参注射液(丹参组)、MP(MP组)、二药联合应用(联合组)及生理盐水(对照组)治疗,观察比较治疗前后动物不同时间的神经功能评分、斜板试验和体感诱发电位,并定量观察受损伤脊髓组织的原位末端标记(TUNEL)阳性细胞数目变化.结果从伤后3周起,治疗组神经功能评分、斜板试验角度以及体感诱发电位与对照组比较差异均有显著性(P＜0.01),联合治疗组与丹参组及激素组比较差异有显著性(P＜0.05).从伤后1周起,丹参组和对照组比较,胶质细胞TUNEL阳性细胞数目显著性减少(P＜0.05).结论复方丹参注射液对大鼠急性脊髓损伤有治疗作用,联合应用复方丹参注射液与MP治疗脊髓损伤具有协同作用.复方丹参注射液可能通过抑制胶质细胞凋亡发挥其治疗作用.     

Synergistic neuroprotective effects of hyperbaric oxygen and methylprednisolone following contusive spinal cord injury in rat

ObjectiveRecent studies revealed the neuroprotective effects of hyperbaric oxygen (HBO) on spinal cord injury (SCI). Meanwhile, the use of methylprednisolone (MP) is one of the current protocols with limited effects in SCI patients. Accordingly, the aim of the present study was to investigate the effect of combined HBO and MP treatment on SCI.DesignThe present study was conducted on five groups of rats each as follows: Sham group (underwent laminectomy alone at T9 level vertebra); SCI group (underwent moderate contusive SCI); MP group (underwent SCI and received MP); HBO group (underwent SCI and received HBO); HBO + MP group (underwent SCI and simultaneously received MP and HBO). Blood serum and Spinal cord tissue samples were taken 48 h after SCI for analysis of serum ferric reducing antioxidant power (FRAP) and tissue malodialdehyde (MDA) levels as well as immunohistochemistry of caspase-3 and tumor necrosis factor-alpha (TNF-α). Neurological function was evaluated by the Basso–Beattie–Bresnehan (BBB) locomotion scores until the end of experiments. Additionally, histopathology was assessed at the end of the study.SettingMazandaran University of Medical Sciences, Sari, Iran.ResultsCombination therapy with HBO and MP in the HBO + MP group significantly decreased MDA as well as increased FRAP levels compared to other treatment groups. Meanwhile, attenuated TNF-α and Caspase-3 expression could be significantly detected in the HBO + MP group. At the end of treatment, the neurological outcome was significantly improved and the extent of injured spinal tissue was also significantly reduced in the HBO + MP compared to other treatment groups.ConclusionThe results suggest that combined therapy with MP and HBO has synergistic effects on SCI treatment.     

大鼠脊髓损伤中的细胞凋亡及甲基强的松龙的干预作用

目的：探讨脊髓损伤（SCI）继发损伤机制,研究损伤脊髓细胞的凋亡及其意义,观察甲基强的松龙（MP）对细胞凋亡的影响。方法：使用改良Allen法制作大鼠急性SCI模型,实验分3组,假损伤（脊髓未受打击）,损伤组及MP治疗组,采用HE,荧光Hoechst 33342,TUNEL(末端脱氧核苷转移酶介导的脱氧尿苷三磷酸生物素缺口末端标记技术）等技术观察SCI后4h,8h,3d,7d,14d,21d及28d时损伤中心及邻近节段脊髓细胞的凋亡,治疗组损伤后30min给予大剂量MP,比较MP治疗组与损伤组脊髓细胞凋亡的变化,同时平行观察大鼠神经学和组织学恢复情况及两组神经丝蛋白（NF）含量的变化。结果：假损伤组各检测方法未见脊髓细胞凋亡,损伤组大鼠急性SCI后1d开始出现脊髓细胞凋亡,3d达高峰,自损伤中心向头尾端递减分布,持续21d,MP治疗组在伤后3d及7d凋亡脊髓细胞较损伤组显著减少,神经学恢复及组织学评分较损伤组有显著性提高,结论：凋亡是SCI后脊髓神经元死亡的一种重要方式,在继发性损伤中起极为重要的作用。MP的治疗作用可能与其干预SCI后细胞凋亡有关。     

Survival and number of olfactory ensheathing cells transplanted in contused spinal cord of rats

Objective： To observe the survival and the number of olfactory ensheathing cells （OECs） transplanted in the contused spinal cord, so as to provide a basis for further studying the biological action of OECs.Methods： The rat spinal cords were contused with NYU-impactor Ⅱ at T10 level by dropping a 10 g rod from a height of 25 mm. At the 1st week after injury, OECs isolated freshly from green fluorecense protein （GFP） of the rats were transplanted into the spinal cord at injured site and other two sites 1 mm apart from the caudal and rostral ends with the OECs number of 30000/μl×3 =90000. The survival and the number of OECs were qualitatively and semi-quantitatively observed under the fluorescense microscope from 1 week to 13 weeks after transplantation. The motor function of the cord was evaluated with BBB score.Results： GFP-OECs could survive at least for 13 weeks within the contused spinal cord. Their arrangement was from tight to loose and their number was decreased from 1 week to 13 weeks after injury. The average number of GFP-OECs was 536 at the 1st week, which was less than 1% of the number as compared with original transplantation. After then, the number of GFP-OECs was continually decreased,but the most obvious decrease was found during 1 week to 2 weeks. The extent of decrease at other time points was relatively mild. In contrast to the cell number, motor function of the cord was gradually recovered after transplantation.Conclusions： The survival and the number of GFPOECs are different between the animals and are affected by the pathological reaction of the host cord. Also it is related to the motor function recovery of the contused cord.     

Progressive cystic degeneration of the spinal cord following spinal cord injury

From a group of 520 spinal cord injury patients treated at Rancho Los Amigos Hospital, two cases of progressive myelopathy secondary to cystic degeneration of the spinal cord have been identified. The cyst may dissect proximately to produce progressive neurologic deficit. Surgical treatment with shunting can allow stabilization and improvement with return of newly lost function.