Protective effect of α-lipoic acid against antimycin A cytotoxicity in MC3T3-E1 osteoblastic cells.

Oxidative stress represents a major cause of cellular damage and death in the process of osteoporosis. Antimycin A (AMA) has been shown to stimulate mitochondrial superoxide anions and reactive oxygen species (ROS). α-Lipoic acid (α-LA) is a naturally occurring essential coenzyme in mitochondrial multienzyme complexes and acts as a key player in mitochondrial energy production. However, whether α-LA affects the cytotoxicity of AMA in osteoblastic cells is unknown. In this study, we investigated the protective effects of α-LA against AMA-induced cytotoxicity using the MC3T3-E1 osteoblast-like cell line. Our results indicated that α-LA treatment attenuated AMA-induced cytotoxicity and LDH release in a dose-dependent manner. Notably, a significant recovery effect of α-LA on mineralization inhibited by AMA was found. Our results also demonstrated that treatment with 50 µM AMA leads to a reduction of mitochondrial membrane potential (MMP) and the complex IV dysfunction, which was inhibited by pretreatment with α-LA in a dose-dependent manner. In addition, treatment with α-LA significantly reduced the generation of ROS and mitochondrial superoxide production induced by AMA. In addition, our result suggests that PI3K/Akt and CREB pathways are related to the protective effect of α-LA. Importantly, Hoechst 33258 staining results indicated that pretreatment with α-LA prevented AMA-induced apoptosis. Mechanistically, we found that α-LA prevents MC3T3-E1 cells from apoptosis through attenuating cytochrome C release and reducing the level of cleaved caspase-3.

Development of improved enzymatic creatinine reagents / 国际检验医学杂志

Objective To develop improved enzymatic creatinine(Cr)assay reagents (self-R&D),and to investigate their appli-cation on serum detection by comparing with imported commercial Cr reagents(enzymatic Cr reagents from Toyobo)Methods En-zymatic method was used to evaluate the effect of every component and different concentrations of reagents on Cr assay by detecting the alteration of absorbance of Cr before or after the reaction.Meanwhile,the blank absorbance and analysis sensitivity of self-R&D and imported reagents,the technical indicators of precision,linearity,as well as method comparison of self-R&D reagents,were de-tected on the same automatic biochemical analyzer.Results The blank absorbance of self-R&D reagents was 0.009,and the detec-tion sensitivity was 0.13,better than that of imported Cr reagents.The coefficient of variation (CV)of high and low values of ser-um of self-R&D reagents were 1.5%,and 1.1%,respectively.The linear range was 0-2 850 μmol/L and the method comparison result was Y =0.98X +1.15 (r =0.999).The expected bias was less than the allowable error region.Using relative deviation≥10% as an index to evaluate the existence of significant interference,it shows that 35 mmol/L of creatine,3.42 mmol/L of biliru-bin,0.03 g/L of vitamin C,5 g/L of hemoglobin and 1450 FTU chyle in both low and high concentration serum samples did not interfere with the test result.Conclusion The quality of self-R&D reagents was good,and there was a good relativity between self-R&D reagents and imported Cr reagents with excellent quality.This indicates the self-R&D reagents could satisfy the application requirements of the clinics.

Evaluation and improvement of anti-interference performance of D-3-hydroxybutyrate detection reagent / 国际检验医学杂志

Objective To evaluate the anti-interference performance of D-3-hydroxybutyrate (D3H ) reagent kit by using the NCCLS document EP7-A2 and to improve its anti-interference performance .Methods The anti-interference evaluation test of D3H kit was performed according to NCCLS document EP7-A2 and its anti-interference performance was improved by adding vitamin C oxidase .Results 342 mol/L free bilirubin ,342 mol/L conjugated bilirubin ,1 450 FTU chyle and 5 g/L hematoglobin had no inter-ference on the high concentration D3H detection ,0 .03 g/L vitamin C interfered with the low and high concentration D3H detection . The dosage-effect experiment results showed that vitamin C produced the linear positive interference effect on D 3H detection . Adding 2 500 U/L of vitamin C oxidase could antagonize the interference of vitamin C on detection .Conclusion Vitamin C can in-terfere with the D3H detection and adding vitamin C oxidase in reagent can antagonize its interference .

Perioperative management in traumatic soft tissue defects with revascularized flaps / 中国组织工程研究

BACKGROUND:Traumatic soft tissue defects of the limbs are usual y accompanied with the exposure of tendon, joint capsule, bone or internal fixator, which can be reconstructed by skin flap. Previous research has shown that it is an important method to repair traumatic tissue defects with flaps. However, rarely research reports perioperative management about flap bed so far. OBJECTIVE:To explore the perioperative strategy for repairing traumatic soft tissue defects with revascularized flaps. METHODS:Total y 94 cases undergoing secondary skin flap repair were enrol ed. Intraoperative debridement using tourniquet was performed, and the wound was washed with mass of physiological saline. Whether the tissues, including bone, tendon, joint capsule and internal fixator, were reserved or not depended on their viability, and then the flaps were harvested to repair defects, and drainage was placed properly at last. RESULTS AND CONCLUSION:The flaps survived in al cases. Exudation occurred in 5 cases with the exposure of bone, and 28 cases with the exposure of tendon or joint capsule healed normal y. No complications were associated with the reservation of the internal fixators, but delayed-union occurred in three cases and nonunion in one case. These findings indicate that the perioperative treatment of the application of skin flap is worthy of attention. Careful debridement, advisable choice of the flap, efficient drainage and using antibiotic normatively are al keys. Treatment of the bone, tendon, joint capsule and internal fixator which are exposed should not only weigh the advantage and disadvantage, but also relax the indication of reserving them.

Effects of nerve growth factor on early-stage fracture healing of the tibia combined with peripheral nerve injury / 中国组织工程研究

BACKGROUND:It is exhibit that nerve growth factor(NGF)and its receptor expresses in normal bone tissue and callus,the local administration of exogenous NGF can promote the healing of fractures.When fracture following peripheral nerve injury happened,the quality of callus significantly affected.OBJECTIVE:To verify the effect of NGF on tibia with peripheral nerve injury in early-stage fracture healing.DESIGN,TIME AND SETTING:A randomized grouping design,animal controlled experiment was performed at the Experimental Animal Center,General Hospital of Jinan Military Area Command of Chinese PLA between May and November 2007.MATERIALS:Forty-eight male Wistar rats,weighting(220?20)g;NGF injection was produced by Xiamen Road of Beijing University Bio-Engineering Co.,Ltd.(Batch number:20070502).METHODS:Forty-eight male Wistar rats were randomly divided into 4 groups,with 24 limbs in each group.Rats in the sodium chloride group were injected sodium chloride after tibia fracture.Rats in the nerve injury with sodium chloride group were injected sodium chloride after tibia fracture combined with nerve injury.In the NGF group,rats were injected NGF after tibia fracture.Rats in the nerve injury with NGF group were nerve injury plus tibia fracture plus NGF.First,the mid-point department circumference of tibia was measured,and then a wedge-shaped groove on the upper tibia anterior was got,and then femoral nerve about 10 mm at the level of the inguinal ligament was cut.Tibia slotted for the opposite,exposed,but not to remove nerve.Turn to prone position,executed the sciatic nerve with a length of about 10 mm on the side of femoral nerve resection at the same time.Contralateral incision exposed.After the surgery,sodium chloride group and nerve injury with sodium chloride group were injected with physiological saline,0.1 mL/limb per day.The rats in the NGF group and nerve injury with NGF group were injected 0.1 mL(0.2 U)NGF per day.MAIN OUTCOME MEASURES:The circumference of crus,X-ray film,wet weight of specimen,and callus metrology observation was measured at weeks 2 and 4 after operation.RESULTS:①The crus shrunk more obvious after never injury,however,NGF promoted the muscle restoration.②The wet weight of specimen and callus at the nerve injury side was more than contralateral side.③There were more callus at the never injury side of nerve injury with sodium chloride group and nerve injury with NGF group than contralateral side at the 2 and 4 weeks,but there were more osteoid,which lacking of normal bone trabecula structure.The callus quantity of NGF group and nerve injury with NGF group had small amount of high density callus with orderly arrayed bone trabecula.CONCLUSION:During fracture,whether nerve injury or not,local injection of NGF can have a passive effect.