OBJECTIVE To determine the role of endogenous carbon monoxide(CO) in oxidant-mediated organ injury following limb ischemia-reperfusion (I/R) in rats. METHODS: Sixty-four SD rats were divided into 4 groups: Sham group, Sham + zinc protoporphyrin (ZnPP, an inhibitor of heme oxygenase activity), 2-hour ischemia followed by 4-hour reperfusion (I/R) group and I/R + ZnPP group. Carboxyhemoglobin (COHb) level in the artery blood, malondialdehyde (MDA) content and superoxide dismutase (SOD) activity in the lung, heart, liver and kidney were detected. The 24-hour survival rate of rats was studied. RESULTS: Compared with the sham group, the COHb level and MDA content significantly increased, while the SOD activity and the survival rate significantly decreased in I/R group (P lt; 0.05). Compared with the I/R group, MDA content significantly increased, while the SOD activity, the 24-hour survival rate and COHb level significantly decreased in I/R + ZnPP group (P lt; 0.05, respectively). CONCLUSION: Limb I/R could lead to the oxidant-mediated multiple organ injury accompanied by the increase of CO level which play an important role in the defense against I/R-induced remote multiple organ injury in rats.
【Abstract】Objective To investigate the effect of donor blood transfusion on inducing pancreatic allograft tolerance in outbred rat model. Methods Wistar male rats were used as blood and pancreas donor, and diabetic recipients. One ml of donor blood injected into abdomen of diabetic recipients on the day of transplantation and azathioprine given 2 days pretransplant and continued for three days. Results Pancreas allograft survival was significantly prolonged (28 to 112 days, media survival time 64.2 days). One ml of donor blood alone injected into the abdomen and azathioprine given alone 2 days pretransplant did not improve allograft survival (media survival time 9.8 vs 10.2 days). Conclusion Donor blood injected on the day of transplantation and a 3 days course of azathioprine started 2 days pretransplant have b synergism in inducing long term graft survival in this rat model.
The current quantitative methods of bilirubin have disadvantages such as high cost and low sensitivity. Due to the negative correlation between the level of serum bilirubin and the risk of cardiovascular diseases, a fluorescent ratiometric film sensor was developed aiming at bilirubin detection at low level concentration. Blue-emitting and red-emitting gold nanoclusters were assembled into the same film using layer-by-layer self-assembly technology. Detection of bilirubin was achieved based on the intensity ratio of the two nanoclusters. Bilirubin exposure causes fluorescent quenching of the film. The fluorescence intensity ratio of the two cluster probes had quantitative relationship versus bilirubin concentration. Based on this film sensor, a portable fluorescence detection system was designed for the ratiometric sensing of bilirubin. The hardware of the system was mainly composed of main control chip STM32F407, TSL237 and TSL238T optical frequency sensor. A light-avoiding dark room and detection light path were designed through three-dimensional printing to reduce the interference from ambient light and improve detection accuracy. Experimental results showed that the proposed detection system had strong anti-interference, good stability and accuracy. The linear coefficient of bilirubin detected by this system was 0.987. The system presented good results in reproducible experiments and possessed a good linear relationship with the data obtained by standard spectrofluorometer. The portable system is expected to detect serum bilirubin at low levels.
Objective To study the growth characteristics of umbil ical cord MSCs (UCMSCs) in vitro and its effect on the nerve regeneration after spinal cord injury (SCI). Methods UCMSCs isolated from pregnant rats umbil ical cord were cultured and purified in vitro. Sixty female Wistar rats weighing (300 ± 10) g were randomized into three groups (n=20per group). UCMSCs group (group A) in which UCMSCs suspension injection was conducted; DMEM control group (groupB) in which 10% DMEM injection was conducted; sham group (group C) in which the animal received laminectomy only.Establ ish acute SCI model (T10) by Impactor model-II device in group A and group B. The recovery of the lower extremity was observed using BBB locomotor scoring system, neurofilament 200 (NF-200) immunofluorescence staining was performed to detect the neural regeneration, and then the corticospinal tract (CST) was observed using the biotinylated dextran amine (BDA) tracing. Results Cultured UCMSCs were spindle-shaped fibrocyte-l ike adherent growth, swirl ing or parallelly. The USMSCs expressed CD29, but not CD31, CD45, and HLA-DR. The BBB score was higher in group A than group B 4, 5, and 6 weeks after operation, and there was a significant difference between two groups (P lt; 0.05). The BBB scores at different time points were significantly lower in groups A and B than that in group C (P lt; 0.05). UCMSCs was proved to survive and assemble around the injured place by frozen section of the cords 6 weeks after injury. NF-200 positive response area in groups A, B, and C was (11 943 ± 856), (7 986 ± 627), and (13 117 ± 945) pixels, respectively, suggesting there was a significant difference between groups A, C and group B (P lt; 0.05), and no significant difference was evident between group A and group C (P gt; 0.05). BDA anterograde tracing 10 weeks after operation demonstrated that more regenerated nerve fibers went through injured area in group A, but just quite few nerve fibers in group B went through the injuried cavity. The ratios of regenerative axons amount to T5 axons in group A and group B were smaller than that of group C (P lt; 0.05). Conclusion UCMSCs can prol iferate rapidly in vitro, survive and differentiate to neurons after being grafted into injured spinal cord. The transplantation of UCMSCs is effective in promoting functional recovery and axonal regeneration after SCI.
Objective To explore the effect of age and gene therapyon the differentiation of marrow mesenchymal stem cells （MSCs） of the rats. Methods MSCs from the young (1-month-old), adult (9-month-old), and the aged(24monthold) rats were expanded in culture and infected with adenovirus mediated human bone morphogenetic protein 2 gene (Ad-BMP-2). The expression of BMP-2 and osteoblastic markers such as alkaline phosphatase(ALP), collagen Ⅰ(Col Ⅰ), bone sialoprotein(BSP) and osteopontin(OPN) were assayed during the process of differentiation. Their abilities to induce ectopic bone formation in nude mice were also tested. Results There was no significant difference in the expression of BMP-2 among the 3 groups. ALP activity assay and semi-quantitative reverse transcription polymerase chain reaction(RT-PCR) demonstrated that there were no significant differences in the expression of osteoblastic markers ALP, Col-Ⅰ, OPN and BSP amongthe 3 groups. Histomorphometric analysis indicated that there were no significant differences in the volume of the newly formed ectopic bones in nude mice amongthe 3 groups. Conclusion MSCs obtained from the aged ratscan restore their osteogenic activity following human BMP-2 gene transduction, therefore provides an alternative to treating the aged bone disease.
A acute partial obstructive hepatocholangitis model by selective ligation and injection of E coli into left hepatic bile duct was successfully founded in rat. Using parameters including mortality, mitochondrial glutamic oxalacetic transaminase and ornithine carbamoytransferase activity, pathological observation and blood culture of bacteria, we evaluated the model. The authors emphasize that this models is superior to the wole-bile-duct-challenged cholangitis model, which is characterized by liver injury.
ObjectiveTo construct recombinant adenovirus expressing nerve growth factor (NGF) and myelin associated glycoprotein (MAG) (Ad-NGF-MAG) and to investigate its effect on repair and regeneration of sciatic nerve injury in rats. MethodsNGF and MAG gene sequences were cloned into shuttle plasmid pCA13 of adenovirus type 5. After packed in HEK293 cells, the recombinant Ad-NGF-MAG underwent sequence and identification. Thirty-two male Sprague Dawley rats were randomly divided into 4 groups (n=8): control group (normal control), adenovirus vector group (Ad group), Ad-NGF group, and Ad-NGF-MAG group. The sciatic nerve injury model was established by transection of the right sciatic nerve; then, the empty adenovirus vector, Ad-NGF, and Ad-NGF-MAG were injected into the gastrocnemius muscle of the affected limb at a dose of 1×108 PFU every other day for 3 times in Ad group, AdNGF group, and Ad-NGF-MAG group, respectively. The right sciatic nerve was exposed only, and then the incision was closed in the control group. The sciatic nerve function index (SFI) was measured, and neuro-electrophysiology was observed; mRNA and protein expressions of NGF and MAG were detected by RT-PCR and Western blot; and histological examination was performed at 31 days after operation. ResultsRecombinant adenovirus vectors of Ad-NGF and Ad-NGF-MAG were constructed successfully. All rats survived and incision healed by first intension. The SFI, nerve conduction velocity, evoked potential amplitude, and latent period of Ad-NGF-MAG group were significantly better than those of Ad group and Ad-NGF group (P < 0.05). MAG mRNA and protein expressions of Ad-NGF-MAG group were the highest in all the groups (P < 0.05). The expressions of NGF mRNA and protein increased in Ad-NGF group and AdNGF-MAG group when compared with control group and Ad group (P < 0.05). Histological examination showed that the nerve had good continuity in control group; nerve fibers disarranged in Ad group; neurons connections formed in some nerve fibers of Ad-NGF group, but nerve fibers arrange disorderly; and the growth of the nerve were ordered and wellstructured in Ad-NGF-MAG group. ConclusionAd-NGF-MAG can effectively promote the growth of the nerve and inhibit the form of abnormal branches, facilitating the repair of sciatic nerve injury in rats.
Objective To investigate the quantity and distribution of motor fiber of rat’s C7 nerve root. Methods Motor fiber quantity and section area in the main nerves of the upper extremity and the fascicles of C7 in 30 SD rats were analyzed.Results Fascicles and certain amount (207) of motor fibers from the anterior division of C7 were distributed to musculocutaneous nerve and median nerve, the orientation of these fibers were not clear. The ones (323) from posterior division were to the axillary, radial, and dorsal thoracic nerves, thus the orientation of these fascicles was relatively definite. Conclusion Thedistribution of the motor fibers and fascicles in the divisions of C7 in rat is similar to human beings, so rat is a relatively good model for the study of selective C7 nerve root transfer.
Objective To explore the key technique of allogeneic whole pancreaticoduodenal transplantation (WPDT) in rats. MethodsWPDT model was established between Lewis rats as donors and Wistar rats (with type 1 diabetes mellitus) as recipients. End to side anastomosis was performed in abdominal aorta of donors and recipients. The portal vein of the graft was anastomosed with the recipients left renal vein by cuff technique. And side to side anastomosis was made between the graft duodenum and the host jejunum. ResultsForty-four of 50 rats were successfully performed WPDT. Amongthem, 8 rats died in postoperative 3 days, the survival time of residual 36 rats was 6-16 days, with an average of (10.45±3.30) days. The peak of death appeared on day 7-10 after operation. The typical acute rejection in pathological changes were observed on day 7. ConclusionSkilled microsurgical techniques and emphasis on details are important to establish WPDT model.
Objective To study the adhesion characteristic in vitrobetween porous biphasic calcium phosphate(BCP) nanocomposite and bone marrow mesenchymal stem cells (MSCs) that have been induced and proliferated. Methods MSCs obtained from SD ratbone marrow were in vitro induced and proliferated. After their osteoblastic phenotype were demonstrated, MSCs were seeded onto prepared porous BCP nanocomposite(experiment group)and common porous hydroxyapatite (control group). Their adhesion situation was analyzed by scanning electron microscope. The initial optimal cell seeding density was investigated between new pattern porous BCP nanocomposite and MSCs by MTT automated colormetric microassay method. Results The differentiation of MSCs to osteoblastic phenotype were demonstrated by the positive staining of mineralized node, alkaline phosphatase (ALP) and collagen typeⅠ, the most appropriate seeding density between them was 2×106／ml. The maximal number which MSCs could adhere to porous BCP nanocomposite was 1.28×107/cm3. Conclusion MSCs can differentiate to osteoblastic phenotype.The MSCs were well adhered to porous BCP nanocomposite.