Temporary hypothyroidism in severe crush syndrome: a potential novel entity.

BACKGROUND: Thyroid hormone synthesis is a complex process in the human body. Although the thyroid gland is essential for thyroid hormone synthesis, skeletal muscles also have crucial roles in thyroid hormone metabolism due to the deiodinase activities of the muscle cells. Hypothyroidism-related myopathy is a well-known entity. However, systemic effects of acute myopathies, such as rhabdomyolysis, on thyroid hormone metabolism have not to date been fully clarified. METHODS: Fifty-three earthquake victims were evaluated retrospectively. We investigated the thyroid function tests (TFTs) among patients with creatine kinase (CK) levels higher than 10.000 U/L at admission. Fifteen patients had CK levels higher than 10.000 U/L and 12 of them had data of TFTs, including thyroid stimulating hormone (TSH), free T4 (FT4), and free T3 (FT3) during hospitalization. These patients were evaluated. RESULTS: TSH levels were increased in all seven patients who required HD due to severe crush syndrome. Decreased FT4 levels were detected in 71.4% of them. None of the five non-HD patients had increased TSH levels or reduced FT4 levels. During follow-up, all patients survived. Renal and thyroid functions were normalized during follow-up without thyroxin replacement in patients with no prior history of hypothyroidism. Moreover, TFTs were normalized in two patients with history of hypothyroidism under thyroxine treatment without dose adjustments. CONCLUSIONS: In severe forms of crush syndrome, temporary hypothyroidism might be seen. The exact mechanism underlying this entity is not well-known. Further clinical and experimental trials should be conducted to illuminate the mechanism of disrupted thyroid hormonogenesis in crush syndrome victims.

Thromboprophylaxis in pediatric patients with earthquake-related crush syndrome: a single centre experience.

PURPOSE: Injuries increase the risk of venous thromboembolism (VTE). However, the literature on the management of anticoagulant therapy in pediatric patients with crush injury is limited. In this study, we aimed to share our experience about anticoagulant thromboprophylaxis in pediatric patients with earthquake-related crush syndrome. METHODS: This study included patients who were evaluated for VTE risk after the Turkey-Syria earthquake in 2023. Since there is no specific pediatric guideline for the prevention of VTE in trauma patients, risk assessment for VTE and decision for thromboprophylaxis was made by adapting the guideline for the prevention of perioperative VTE in adolescent patients. RESULTS: Forty-nine patients [25 males and 24 females] with earthquake-related crush syndrome had participated in the study. The median age of the patients was 13.5 (8.8-15.5) years. Seven patients (14.6%) who had no risk factors for thrombosis were considered to be at low risk and did not receive thromboprophylaxis. Thirteen patients (27.1%) with one risk factor for thrombosis were considered to be at moderate risk and 28 patients (58.3%) with two or more risk factors for thrombosis were considered to be at high risk. Moderate-risk patients (n = 8) and high-risk patients aged < 13 years (n = 11) received prophylactic enoxaparin if they could not be mobilized early, while all high-risk patients aged ≥ 13 years (n = 13) received prophylactic enoxaparin. CONCLUSION: With the decision-making algorithm for thyromboprophylaxis we used, we observed a VTE rate of 2.1% in pediatric patients with earthquake-related crush syndrome.

Precision engineered peptide targeting leukocyte extracellular traps mitigate acute kidney injury in Crush syndrome.

Crush syndrome induced by skeletal muscle compression causes fatal rhabdomyolysis-induced acute kidney injury (RIAKI) that requires intensive care, including hemodialysis. However, access to crucial medical supplies is highly limited while treating earthquake victims trapped under fallen buildings, lowering their chances of survival. Developing a compact, portable, and simple treatment method for RIAKI remains an important challenge. Based on our previous finding that RIAKI depends on leukocyte extracellular traps (ETs), we aimed to develop a novel medium-molecular-weight peptide to provide clinical treatment of Crush syndrome. We conducted a structure-activity relationship study to develop a new therapeutic peptide. Using human peripheral polymorphonuclear neutrophils, we identified a 12-amino acid peptide sequence (FK-12) that strongly inhibited neutrophil extracellular trap (NET) release in vitro and further modified it by alanine scanning to construct multiple peptide analogs that were screened for their NET inhibition ability. The clinical applicability and renal-protective effects of these analogs were evaluated in vivo using the rhabdomyolysis-induced AKI mouse model. One candidate drug [M10Hse(Me)], wherein the sulfur of Met10 is substituted by oxygen, exhibited excellent renal-protective effects and completely inhibited fatality in the RIAKI mouse model. Furthermore, we observed that both therapeutic and prophylactic administration of M10Hse(Me) markedly protected the renal function during the acute and chronic phases of RIAKI. In conclusion, we developed a novel medium-molecular-weight peptide that could potentially treat patients with rhabdomyolysis and protect their renal function, thereby increasing the survival rate of victims affected by Crush syndrome.

Zinc chelator treatment in crush syndrome model mice attenuates ischemia-reperfusion-induced muscle injury due to suppressing of neutrophil infiltration.

In crush syndrome, massive muscle breakdown resulting from ischemia-reperfusion muscle injury can be a life-threatening condition that requires urgent treatment. Blood reperfusion into the ischemic muscle triggers an immediate inflammatory response, and neutrophils are the first to infiltrate and exacerbate the muscle damage. Since free zinc ion play a critical role in the immune system and the function of neutrophils is impaired by zinc depletion, we hypothesized that the administration of a zinc chelator would be effective for suppressing the inflammatory reaction at the site of ischemia-reperfusion injury and for improving of the pathology of crush syndrome. A crush syndrome model was created by using a rubber tourniquet to compress the bilateral hind limbs of mice at 8 weeks. A zinc chelator N,N,N',N'-tetrakis-(2-pyridylmethyl)-ethylenediamine (TPEN) was administered immediately after reperfusion in order to assess the anti-inflammatory effect of the chelator for neutrophils. Histopathological evaluation showed significantly less muscle breakdown and fewer neutrophil infiltration in TPEN administration group compared with control group. In addition, the expression levels of inflammatory cytokine and chemokine such as IL-6, TNFα, CXCL1, CXCL2, CXCR2, CCL2 in ischemia-reperfusion injured muscle were significantly suppressed with TPEN treatment. Less dilatation of renal tubules in histological evaluation in renal tissue and significantly better survival rate were demonstrated in TPEN treatment for ischemia-reperfusion injury in crush syndrome. The findings of our study suggest that zinc chelators contributed to the resolution of exacerbation of the inflammatory response and attenuation of muscle breakdown in the acute phase after crush syndrome. In addition, our strategy of attenuation of the acute inflammatory reaction by zinc chelators may provide a promising therapeutic strategy not only for crush syndrome, but also for other diseases driven by inflammatory reactions.

Ulinastatin ameliorates acute kidney injury induced by crush syndrome inflammation by modulating Th17/Treg cells.

BACKGROUND: Acute kidney injury (AKI) is the main complication of crush syndrome (CS), and it is also a cause of lethality in CS. However, effective treatments for AKI are still lacking. Ulinastatin (UTI) is a broad-spectrum serine protease inhibitor extracted from human urine that reportedly modulates innate immunity and pro-inflammatory responses in sepsis. Here, we explored the effect and the potential mechanism of ulinastatin on crush syndrome-induced acute kidney injury (CSAKI). METHODS: A CSAKI rat model was established by using a digital crush injury device platform. Forty-six male Wistar rats were randomly divided into five groups: the normal control (n = 6), CSAKI model (n = 10), CSAKI plus UTI1 (50,000 U/kg) (n = 10), CSAKI plus UTI2 (100,000 U/kg) (n = 10) and CSAKI plus UTI3 (200,000 U/kg) (n = 10) groups. Hematoxylin-eosin (HE) staining was used to investigate the reliability of the CSAKI model. The percentage of Th17/Treg lymphocytes in peripheral blood was measured by flow cytometry, and the expression of transcription factors associated with Th17/Treg cells was evaluated by quantitative real-time polymerase chain reaction (PCR). In addition, specific cytokines released by Th17/Treg cells in serum and kidney tissues were detected by enzyme-linked immunosorbent assay (ELISA). RESULTS: Treatment with ulinastatin could significantly decrease serum BUN, CK, Scr, Mb and K+ levels compared with CSAKI group. HE staining results showed that ulinastatin could inhibit inflammatory cells infiltration, decrease sarcomere rupture in muscle tissues induced by extrusion, and alleviate the glomerular congestion and edema, as well as decrease myoglobin cast in kidney tissues. The proportion of CD4+CD25+Foxp3+ regulatory T (Treg) cells and Foxp3 expression levels were decreased in the CSAKI animals, while IL-17 expression levels were significantly increased, compared with those of the normal control group. Treatment with ulinastatin upregulated the proportion of Treg cells in CD4+ T cells and downregulated the expression of IL-17 compared with those of the CSAKI group. CONCLUSION: The findings of our study indicate that UTI attenuates CS-induced AKI and alleviate the inflammatory response during the early stage. The mechanism of UTI may be due to regulating the balance between Th17/Treg cells. Our study provides a new mechanism for the beneficial effect of ulinastatin on CSAKI.

Immunomodulatory role of recombinant human erythropoietin in acute kidney injury induced by crush syndrome via inhibition of the TLR4/NF-κB signaling pathway in macrophages.

Objective: The present study aimed to investigate whether recombinant human erythropoietin (rHuEPO) plays an immunomodulatory function by regulating the TLR4/NF-κB signaling pathway.Materials and methods: C57BL/6 mice were intraperitoneally injected with rHuEPO and, half an hour later, with 50% glycerol at the dose of 7.5 ml/kg to induce crush syndrome (CS)-acute kidney injury (AKI). The levels of TNF-α, IL-1ß, IL-6, serum creatinine (Scr), and creatine kinase (CK) were measured. The kidney tissues were analyzed by HE staining, and macrophage infiltration was detected by immunohistochemistry. Double immunofluorescence staining, RT-qPCR, and western blotting were conducted to analyze TLR4/NF-κB p65 expression. Ferrous myoglobin was co-cultured with RAW264.7 cells to mimic crush injury and the production of proinflammatory cytokines. The expression levels of TLR4 and NF-κB p65 were measured.Results: In vivo study results revealed that rHuEPO ameliorated renal function, tissue damage, production of proinflammatory cytokines, and macrophage infiltration in the kidneys. The protein and mRNA expression levels of genes involved in the TLR4/NF-κB signaling pathway in CS-induced AKI mice were upregulated (p < .05). Meanwhile, the expression levels of TLR4, NF-κB p65, and proinflammatory cytokines in RAW264.7 cells were downregulated in CS-AKI mice injected with rHuEPO (p < .05).Conclusions: Our results demonstrated the immunomodulatory capacity of rHuEPO and confirmed that rHuEPO exerts protective effects against CS-induced AKI by regulating the TLR4/NF-κB signaling pathway in macrophages. Therefore, our findings highlight the therapeutic potential of rHuEPO in improving the prognosis of CS-AKI patients.

Nitrite as a pharmacological intervention for the successful treatment of crush syndrome.

Crush syndrome is characterized by ischemia/reperfusion injury (IRI). The protective effect of nitrite on experimentally induced IRI has been demonstrated in the heart, kidney, liver, and skeletal muscle. IRI in tissues and systemic organs occurs due to the massive generation of reactive oxygen species and subsequent systemic inflammation. Therefore, ischemic pre and postconditioning are performed in clinical practice. Intravenous administration of nitrite inhibits IRI through nitric oxide-mediated mechanisms. In this paper, we discuss the utility of nitrite as a pharmacological postconditioning agent in the treatment of crush syndrome.

Combined administration of anisodamine and neostigmine rescued acute lethal crush syndrome through α7nAChR-dependent JAK2-STAT3 signaling.

Previously we showed that Ani (anisodamine)/Neo (neostigmine) combination produced anti-shock effect via activating α7 nicotinic acetylcholine receptor (α7nAChR). In this study, we aim to investigate the therapeutic effect and underlying mechanisms of Ani/Neo combination in acute lethal crush syndrome (CS). In rat and rabbit CS models, Ani/Neo combination increased the 24 h survival rates, improved hemodynamics and decreased the levels of creatine kinase, MB isoenzyme of creatine kinase, blood urea nitrogen, creatinine, K+ in serum. It also decreased the levels of H2O2, myeloperoxidase (MPO) and nitric oxide (NO) in serum and compressed muscle in rat CS model. In wild-type (WT) mice with CS, Ani/Neo combination increased 24 h survival rate and decreased the levels of H2O2, MPO, NO, TNFα, IL-6 and IL-10 in compressed muscle. These effects were attenuated by α7nAChR knockout (KO). Moreover, Ani/Neo combination prevented the decrease of phosphorylation of Janus kinase 2 (JAK2) and phosphorylation of signal transducer and activator of transcription 3 (STAT3) induced by CS. These effects of Ani/Neo in CS mice were cancelled by methyllycaconitine (α7nAChR antagonist) and α7nAChR KO. Collectively, our results demonstrate that Ani/Neo combination could produce therapeutic effects in CS. The underlying mechanism involves the activation of α7nAChR-dependent JAK2-STAT3 signaling pathway.

Effects of acetaminophen and mannitol on crush injuries in rats: An experimental study.

BACKGROUND: The present objective was to evaluate effects of acetaminophen and mannitol on renal function and histopathology in crush injuries. METHODS: Thirty-six rats weighing 370-400 g each were used. No surgery was performed on the first (control) group. The gastrocnemius muscle regions of each rat in the remaining 5 groups were compressed for 2 or 24 hours. In the 4th group, 100 mg/kg acetaminophen was intraperitoneally administered. In the 5th group, 1 g/kg mannitol was administered. In the 6th group, 100 mg/kg acetaminophen and 1 g/kg mannitol were administered. RESULTS: No statistically significant differences were observed among the treatment groups in terms of sodium, potassium, alanine aminotransferase (ALT), and average creatinine clearance values. Hydropic degeneration, tubular necrosis, presence of immunoperoxidase and myoglobin, tubulus epithelial cell degeneration, and presence of PAS-dyed material in tubular lumen was more prominently decreased in the acetaminophen group than the mannitol group. Improvement was observed in the group that was administered both drugs, compared to the mannitol-only group, though findings were still worse than those of the group administered acetaminophen only. CONCLUSION: In crush injuries, acetaminophen improves histopathological renal damage better than mannitol. When used in conjunction with mannitol, the toxic effect of acetaminophen on the liver is decreased.

Early Therapeutic Intervention for Crush Syndrome: Characterization of Intramuscular Administration of Dexamethasone by Pharmacokinetic and Biochemical Parameters in Rats.

Crush syndrome (CS) is the systemic manifestation of muscle cell damage resulting from pressure and crushing. It is associated with a high mortality rate, even when patients are treated with conventional therapy. We demonstrated the utility of intramuscular administration of dexamethasone (DEX) in disaster medical care by using a model of CS to characterize the pharmacokinetics and biochemical parameters. We compared intravenous (IV) and intramuscular (IM) injection. The IM sites were the right anterior limb (AL), bilateral hind limbs (bHL), and unilateral hind limb (uHL). DEX (5.0 mg/kg) was administered in sham-operated (sham, S-IV, S-AL, S-bHL, S-uHL groups) and CS rats (control, C-IV, C-AL, C-bHL, C-uHL groups). The survival rate in the IM groups was lower than that in the C-IV group. Survival was highest in the C-AL group, followed by the C-uHL and C-bHL groups. The blood DEX concentration of the C-AL group was similar to that in the C-IV group. The C-bHL and C-uHL groups had decreased blood DEX concentrations. Moreover, inhibition of inflammation was related to these changes. Administration of DEX to non-injured muscle, as well as IV administration, increased the survival rate by modulating shock and inflammatory mediators, consequently suppressing myeloperoxidase activity and subsequent systemic inflammation, resulting in a complete recovery of rats from lethal CS. These results demonstrate that injection DEX into the non-injured muscle is a potentially effective early therapeutic intervention for CS that could easily be used in transport to the hospital.

The Beneficial Effects of ETS-GS, a Novel Vitamin E Derivative, on a Rat Model of Crush Injury.

Crush syndrome is a devastating condition leading to multiple organ failure. The mechanisms by which local traumatic injuries affect distant organs remain unknown. ETS-GS is a novel water-soluble, stable anti-oxidative agent composed of vitamin E derivative. Given that one of the main pathophysiological effects in crush syndrome is massive ischemia-reperfusion, reactive oxygen species (ROS) generated from the injured extremities would be systemically involved in distant organ damage. We investigated whether ETS-GS could suppress inflammatory response and improve mortality in a rat model of crush injury. Crush injury was induced by compression of bilateral hindlimbs for 6 h followed by release of compression. Seven-day survival was significantly improved by ETS-GS treatment. To estimate anti-oxidative and anti-inflammatory effects of ETS-GS, serum was collected 6 and 20 h after the injury. ETS-GS treatment significantly dampened the up-regulation of malondialdehyde and reduction of superoxide dismutase in the serum, which were induced by crush injury. Serum levels of interleukin 6 and high mobility group box 1 were significantly decreased in the ETS-GS group compared with those in the control group. Lung damage shown by hematoxylin-eosin staining at 20 h after the injury was ameliorated by the treatment. Ex vivo imaging confirmed that ETS-GS treatment reduced ROS generation in both the lung and the muscle following crush injury. The administration of ETS-GS could suppress ROS generation, systemic inflammation, and the subsequent organ damage, thus improving survival in a rat model of crush injury. These findings suggest that ETS-GS can become a novel therapeutic agent against crush injury.

Improved angiogenesis and healing in crush syndrome by fibroblast growth factor-2-containing low-molecular-weight heparin (Fragmin)/protamine nanoparticles.

BACKGROUND: We produced fibroblast growth factor (FGF)-2-containing low-molecular-weight heparin (Fragmin)/protamine nanoparticles (FGF-2 + F/P NPs). The purpose of this study was to evaluate the effectiveness of the local administration of FGF-2 + F/P NPs on repairing crush syndrome (CS)-injured lesions after compression release using a nonlethal and reproducible CS injury rat model. MATERIALS AND METHODS: The hind limbs of the anesthetized rats were compressed for 6 h using 3.6 kg blocks, as previously described. The effects of administering FGF-2 + F/P NPs (group A), F/P NPs alone (group B), FGF-2 alone (group C), and saline (control; group D) were examined. Motor function, surface blood flow in the hind limbs, and the wet/dry weight ratio in the tibialis anterior muscle were examined for 1-28 d after the compression release. Histologic analyses were also performed. RESULTS: At the middle and late stages (3-28 d after the compression release), group A had higher scores in the motor function, improved blood flow, increased number of blood vessels, and faster recovered muscle tissue, compared with the other groups. There was no significant difference in enhanced edema in the tibialis anterior muscle among all groups. CONCLUSIONS: The local administration of FGF-2 + F/P NPs to a CS-injured lesion was effective in repairing damaged muscle tissue after compression release.

[Key points in clinical pharmaceutical education and research, as seen from pharmaceutical consultation clinics].

Pharmaceutical education was expanded to a 6-year system in 2006, in an efforts to enhance clinical pharmaceutical research and education. Since that time, pharmacists have attempted to participate in medical all aspects of medical care, but an environment in which they can master direct pharmaceutical techniques for patients has not yet been sufficiently developed. This is because pharmaceutical education emphasizes the acquisition of knowledge and has not reached the point where it cultivates minds that can adapt to the multitude of situations that are envisaged in medical settings. By incorporating physical assessment in pharmaceutical settings, it is believed that a mind-set of treating patients can be formed in students, leading to the development of pharmacists skilled in the implementation of their area of treatment. We feel that, by shifting to clinical pharmaceutical education and research we will realize an integrated ability in pharmacists to treat patients, which will earn multifaceted appreciation from both patients themselves and medical practitioners. The pharmaceutical consultation clinic established at Mie University offers second opinions by pharmacists, but patients' opinions of pharmacists are tepid and the letter sometimes became the target of acerbic comments. This is a reflection of the current state in which pharmacists have not made their role in medicine clear. Ultimately, efforts must be made to resolve anxiety with respect to the things patients want to hear, without evading this responsibility even when under pressure. Pharmaceutical science should always be cognizant of what the pharmacists' contribution to medicine, should be, and research a means to help that individual acquire the ability to make quick though careful judgments while gathering needed findings.

[Pharmacokinetics characteristics of dexamethasone in Crush syndrome model rats].

Crush syndrome (CS) is characterized by ischemia/reperfusion-induced rhabdomyolysis and subsequent systemic inflammation and has a high mortality rate, even when treated with conventional therapy. In previous studies, we demonstrated that treatment of rats with acute lethal CS using dexamethasone (DEX) had therapeutic effects in laboratory findings and improved the clinical course of CS. However, because the application of DEX in CS therapy is unknown, evaluation of the pharmacokinetic parameters of DEX was considered essential to support its clinical use. Here, we investigated the pharmacokinetic characteristics of DEX in a rat model of CS. Anesthetized rats were subjected to bilateral hind limb compression using rubber tourniquets for 5 h, followed by reperfusion for 0 to 24 h. Rats were divided randomly into 4 groups: saline-treated sham (S) and CS groups and 5.0 mg/kg DEX-treated S (S-DEX) and CS (CS-DEX) groups. Blood and tissue samples were collected for HPLC analysis. In the CS-DEX group, the pharmacokinetic parameters of the area under the concentration-time curve, mean residence time, and distribution volume levels increased significantly compared to the S-DEX group, whereas total body clearance, elimination rate constant, and renal clearance levels decreased significantly. Moreover, decrease of muscle tissue DEX concentration and of CYP3A activity were observed in the CS-DEX group. These results show the pharmacokinetic characteristics of DEX in the rat CS model and support the potential use of DEX in disaster medical care.

Acute lethal crush-injured rats can be successfully rescued by a single injection of high-dose dexamethasone through a pathway involving PI3K-Akt-eNOS signaling.

BACKGROUND: Crush syndrome (CS) is characterized by ischemia/reperfusion-induced rhabdomyolysis and the subsequent onset of systemic inflammation. CS is associated with a high mortality, even when patients are treated with conventional therapy. We hypothesized that treatment of lethal CS rat model with dexamethasone (DEX) have therapeutic effects on the laboratory findings and clinical course and outcome. METHODS: To create a CS model, anesthetized rats were subjected to bilateral hind limb compression with rubber tourniquets for 5 hours and randomly divided into three groups as follows: saline-treated CS group, CS groups treated with low (0.1 mg/kg) and high doses (5.0 mg/kg) of DEX. Saline for the CS group or DEX for the DEX-treated CS groups was intravenously administered immediately before reperfusion. Under continuous monitoring and recording of arterial blood pressures, blood and tissue samples were collected for histologic and biochemical analysis at designated period before and after reperfusion. RESULTS: Ischemic compression of rat hind limbs reduced the nitrite content in the crushed muscle, and the subsequent reperfusion induced reactive oxygen species-mediated circulatory collapse and systemic inflammation, finally resulting in a mortality rate of 76% by 48 hours after reperfusion. A single injection of high-dose DEX immediately before reperfusion activated endothelial nitric oxide synthase (eNOS) by sequential phosphorylation through the nongenomic phosphoinositide 3-kinase (PI3K)-Akt-eNOS signaling pathway. DEX also exhibited anti-inflammatory effects by modulating proinflammatory and anti-inflammatory mediators, consequently suppressing myeloperoxidase activities and subsequent systemic inflammation, showing a complete recovery of the rats from lethal CS. CONCLUSION: These results indicate that high-dose DEX reduces systemic inflammation and contributes to the improved survival rate in a rat CS model.

Effect of free radical scavenger on c-jun activation in rats with crush syndrome.

OBJECTIVES: To evaluate the relationship between reactive oxygen species (ROS)-mediated kidney injuries and Jun N-terminal kinase (JNK) activity and the therapeutic effects of tempol in crush syndrome (CS) model rats. METHODS: Male Wister rats were randomly divided into sham operation group (SOG), CS groups (CS6G, CS12G and CS24G) and tempol treatment group (TG, a ROS scavenger). CS model rats were established by crushing the hind limbs of rats with 15 kg pressure for 6 hours, and inferior caval vein blood and kidney samples were harvested at 6, 12, 24 hours after removing crush pressure. In TG, 100 mg/kg tempol was intraperitoneally injected into CS model rats after withdraw of crush pressure. In SOG, rats were fixed on the board without any crush pressure. The activation of c-jun was determined by western blotting. Serological parameters and the content of malondialdehyde (MDA) in kidney tissues were determined by standard methods. RESULTS: Acute kidney injury reached the peak at 12 hours after the crush pressure. Compared with SOG, the content of phosphorylated c-jun was significantly higher in CSG and TG (p < 0.05), and the content of phosphorylated c-jun in the CSG was significantly higher than that in TG (p < 0.05). Interestingly, the changes of the MDA content in the kidney tissues of the 3 groups were similar to the changes of phosphorylated c-jun content. CONCLUSION: ROS-mediated phosphorylation of c-jun may play important roles in the acute kidney injury of CS rats. Tempol can inhibit the phosphorylation of c-jun and alleviate the acute kidney injury.

(-)-Epigallocatechin-3-gallate (EGCG) attenuates peripheral nerve degeneration in rat sciatic nerve crush injury.

Recently, we have shown that green tea (GT) consumption improves both reflexes and sensation in unilateral chronic constriction injury to the sciatic nerve. Considering the substantial neuroprotective properties of GT polyphenols, we sought to investigate whether (-)-epigallocatechin-3-gallate (EGCG) could protect the sciatic nerve and improve functional impairments induced by a crushing injury. We also examined whether neuronal cell apoptosis induced by the crushing injury is affected by EGCG treatment. Histological examination of sciatic nerves from EGCG-treated (50mg/kg; i.p.) showed that axonotmized rats had a remarkable axonal and myelin regeneration with significant decrease in the number of myelinated axonal fibers compared to vehicle-treated crush group. Similarly, ultrastructural evaluation of EGCG-treated nerves displayed normal unmyelinated and myelinated axons with regular myelin sheath thickness and normalized appearance of Schmidt-Lantermann clefts. Extracellular matrix displayed normal collagen fibers appearance with distinctively organized distribution similar to sham animals. Analysis of foot position and extensor postural thrust test showed a progressive and faster recovery in the EGCG-treated group compared to vehicle-treated animals. EGCG-treated rats showed significant increase in paw withdrawal thresholds to mechanical stimulation compared to vehicle-treated crush group. EGCG treatment also restored the mRNA expression of Bax, Bcl-2 and survivin but not that of p53 to sham levels on days 3 and 7 post-injury. Our results demonstrate that EGCG treatment enhanced functional recovery, advanced morphological nerve rescue and accelerated nerve regeneration following crush injury partly due to the down regulation of apoptosis related genes.

Sivelestat improves outcome of crush injury by inhibiting high-mobility group box 1 in rats.

Severe crush injury is associated with high mortality because of resulting hyperkalemia in early phase and multiorgan dysfunction in later phase. In this study, we investigated the effects of sivelestat administration 1 h before reperfusion on the outcome of crush injury. Crush injury was induced by 6 h of direct compression to both hindlimbs of anesthetized rats with blocks weighing 3.5 kg each side, followed by 3 h of reperfusion. Rats were randomly assigned to three groups. In the control group, rats were infused with normal saline at 1 mL/kg per hour throughout the experiment without compression. Rats in the positive control group were compressed for 6 h, followed by fluid resuscitation initiated 1 h before release with normal saline. The infusion rate was increased from 1 to 10 mL/kg per hour and continued for 4 h. Rats in the treated group underwent the same procedures as in the positive control group, but sivelestat was added to normal saline (concentration was adjusted to infuse 10 mg/kg per hour) during fluid resuscitation (for 4 h). Treatment with sivelestat significantly improved survival rate with P = 0.032. This was accompanied by lower serum high-mobility group box 1 (HMGB1) levels after 3-h reperfusion, attenuated lung injury (assessed using hematoxylin-eosin stain), and suppression of HMGB1 expression in the lung and the liver. These results suggest that treatment with sivelestat improves the outcome of crush injury, likely by inhibiting HMGB1 in rats.

Effect of ginkgo biloba extract on recovery after facial nerve crush injury in the rat.

BACKGROUND AND OBJECTIVE: Many pharmacological agents have shown successful results in experimental crush injury of the peripheral nerve. To date, therapeutic effect of ginkgo biloba extract (GBE) on the peripheral nerve crush injury of rats has been rarely reported, moreover, neuroprotective effect on the facial nerve crush injury has not been reported. MATERIALS AND METHODS: Prospective functional recovery, using a vibrissae movement and electrophysiological analysis of recovery 4 weeks after the facial nerve crush in adult rats, and comparison with randomized intraperitoneal injection of either GBE or control phosphate buffered saline. RESULTS: Relative to the control group (26 days post operation), administration of GBE significantly accelerated the recovery of vibrissae orientation to 11.7 days post the operation. A significant functional recovery was observed by postoperative 2nd week in the experimental group. The recovery of threshold and conduction velocity, postoperative 4th week in the experimental group, showed statistically significant difference compared to that of the control group. CONCLUSION: From this result, intraperitoneal injection of GBE has been found effective in promoting the regeneration of the nerve in an experimental facial nerve crush rat model. Further studies, including morphological and molecular analyses, are necessary to clarify the mechanisms of GBE on the facial nerve crush.