BACKGROUND: New porous β-tricalcium phosphate (TCP) was made by appropriate prescription and unique technology, with a porosity of (75±10)%, spheroidal hole>80%, micropore<20%, interlink rate between the holes of 100% and mechanical strength>2MPa.OBJECTIVE: To assess the application outcome of the new porous β-TCP as a scaffold for bone tissue engineering.DESIGN, TIME AND SETTING: The control experiment was performed at the Laboratory of Tissue Engineering of Southern Medical University, China from July 2005 to March 2006.MATERIALS: Twelve 6-month New Zealand rabbits were used to create 1.5cm large bone and periosteum defects of the left radial bone. Porous β-TCP was purchased from bio-lu, France.METHODS: Osteoblasts differentiated from rabbit bone marrow mesenchymal stem cells (BMSCs) were co-cultured with porous β-TCP. Inverted phase contrast microscope and scanning electron microscope were used to observe the growth of BMSCs. MTT assay was employed to assess cell proliferation and compatibility. Cytotoxicity was detected by analyzing the effects of different concentrations of porous β-TCP leaching liquor on cell proliferation.MAIN OUTCOME MEASURES: Cell compatibility and cytotoxicity of β-TCP were measured. The status of bone defect repair was appraised by histology, radionuclide bone scan and X-ray at 2, 6, 12 weeks after surgery.RESULTS: The new porous β-TCP had good cell adhesion and its cytotoxicity was in 0 grade. Histology, imageology and radionuclide bone scan showed the new porous β-TCP could repair large radial bone defect in rabbits. At the same time, its degradation rate was accordance with bone formation rate in vivo.CONCLUSION: The new porous β-TCP with a good compatibility is a good scaffold for bone tissue engineering, and obtains good outcomes in repairing large bone defect of rabbit radial bone.

BACKGROUND:Retinoid X receptor (RXR) plays a central role in the regulation of intracellular receptor signaling pathways. The activation of RXR has protective effect on H2O2-induced apoptosis of H9c2 ventricular cells in rats. But the protective effect and mechanism of activating RXR in cardiomyocytes against hypoxia/reoxygenation (H/R)-induced oxidative iniury are stillunclear. METHODS:The model of H/R injury was established through hypoxia for 2 hours and reoxygenation for 4 hours in H9c2 cardiomyocytes of rats. 9-cis-retinoic acid (9-cis RA) was obtained as an RXR agonist, and HX531 as an RXR antagonist. Cultured cardiomyocytes were randomly divided into four groups:sham group, H/R group, H/R+9-cis RA -pretreated group (100 nmol/L 9-cis RA), and H/R+9-cis RA+HX531-pretreated group (2.5 μmol/L HX531). The cellviability was measured by MTT, apoptosis rate of cardiomyocytes by flow cytometry analysis, and mitochondrial membrane potential (ΔΨm) by JC-1 fluorescent probe, and protein expressions of Bcl-2, Bax and cleaved caspase-9 with Western blotting. Allmeasurement data were expressed as mean±standard deviation, and analyzed using one-way ANOVA and the Dunnett test. Differences were considered significant whenP was <0.05. RESULTS:Pretreatment with RXR agonist enhanced cellviability, reduced apoptosis ratio, and stabled ΔΨm. Dot blotting experiments showed that under H/R stress conditions, Bcl-2 protein level decreased, while Bax and cleaved caspase-9 were increased. 9-cis RA administration before H/R stress prevented these effects, but the protective effects of activating RXR on cardiomyocytes against H/R induced oxidative injury were abolished when pretreated with RXR pan-antagonist HX531. CONCLUSION:The activation of RXR has protective effects against H/R injury in H9c2 cardiomyocytes of rats through attenuating signaling pathway of mitochondria apoptosis.

Tumor immune checkpoint therapy is a clinical treatment strategy developed based on the new principle of the inhibition of negative immune regulation. In this article, the tumor immune checkpoint therapy and the drug delivery strategies were reviewed, mainly including immunity and tumor therapy, tumor immune checkpoint therapy and its mechanism of action, clinical application of tumor immune checkpoint therapy and therapeutic drugs, immune resistance of programmed cell death protein 1 (PD1)/programmed cell death ligand 1 (PDL1) treatment and countermeasures, drug delivery strategies for tumor immune checkpoint therapeutic agents, etc. As a revolutionary new immunotherapy strategy, tumor immune checkpoint therapy has shown obvious superior therapeutic efficacy in a variety types of tumor. However, tumor immune checkpoint therapy is also faced with a big challenge, namely, immunotherapy resistance. With the discovery of new mechanism, the continuous development of new therapeutic drugs and delivery strategies, tumor immune checkpoint therapy is expected to further improve the clinical efficacy of tumor.

AIMTo investigate the effects of shivering on airway rewarming.

METHODSThe hypothermic dog model without shivering was established by immersing an anesthetized dog in cold water and administering atracurium to inhibit the dog shivering. The model dog respired warm fully humidified (40-45 degrees C, RH 99.9%) air and room temperature air(19 +/- 1 degrees C, RH 30% - 75%) to rewarm each for 2 hours, the priority of different temperature air respired was arranged randomly. After rewarming for 4 hours, the relaxed dog breathed warm humidified air by positive pressure ventilation in order to restore its spontaneous respiratory. Then the dog continued to respire warm humidified air spontaneously until the esophageal (Te) and rectal temperature (Tr) of the dog achieved the same degrees as the dog was immersed in the water. The metabolic heat production was detected by indirect calorimetry during the experiment.

RESULTS(1) When the shivering was inhibited, inhaling warm humidified air for 2 hours made the Tr and Te of the dogs increase 0.26-0.39 degrees C and 0.44-1.11 degrees C per hour respectively, inhaling air at room temperature for 2 hours made Tr and Te of the dogs decrease 0.24-0.51 degrees C and 0.58-0.67 degrees C per hour, respectively. And the changes in Tr and Te of the dogs were unrelated to the priority of inhaling air at different temperature. (2) When the dog with shivering respired spontaneously warm humidified air, the rewarming rates of Tr and Te were 2.26-2.33 degrees C/h and 1.96-2.38 degrees C/h respectively, quicker than those of the dogs whose shivering was inhibited. (3) Compared with metabolic heat production of the unshivering dog respiring warm humidified air by positive pressure ventilation, that of the shivering dog respiring warm humidified air spontaneously increased outstandingly, shivering thermogenesis made the rewarming rates increased obviously.

CONCLUSIONAirway rewarming is a method conducive to rewarming of hypothermia. When the body is shivering, the metabolic heat production increases obviously, that makes the rewarming rate increase markedly. So the shivering must be inhibited in order to eliminate the interference of shivering thermogenesis when the effects of airway rewarming are detected.

Animals ; Body Temperature Regulation ; Cold Temperature ; Dogs ; Hypothermia ; physiopathology ; therapy ; Hypothermia, Induced ; Male ; Respiratory Physiological Phenomena ; Shivering

AIMTo investigate the role of ICAM-1 on the surface of vascular endothelial cell (VEC) in freezing/thawing injury of VEC, in order to elucidate the pathogenesis of freezing/thawing injury.

METHODSVEC separated and cultured from rat aorta and PMN separated from rat peripheral blood were selected as experiment materials. The frozen/thawed VEC model was founded by freezing VEC with the type WKL-V rate cooling instrument and then rewarming them in a water bath. ICAM-1 expression on the surface of frozen/thawed VEC was detected at 4, 12 and 24 h after freezing/thawing with immunohistochemical method. After coincubating frozen/thawed VEC with normal PMN, the adhesion of VEC to PMN was monitored with rose bengal staining assay and the injury level of VEC was indicated by measuring LDH activity in nutrient solution.

RESULTSThe ICAM-1 expression on the surface of VEC increased from 13.2% +/- 3.6% before freezing/thawing of VEC to 22.3% +/- 4.4% at 4 hour after freezing/thawing, and reached the peak (37.9% +/- 2.5%) at 12 hour after freezing/thawing of VEC. After coincubation of frozen/thawed VEC with normal PMN, the adherence of frozen/thawed VEC to PMN increased from group control 0.204 +/- 0.025 to 0.363 +/- 0.022 (P < 0.01), LDH activity in nutrient solution increased from group control 104.64 +/- 20.14 U/L to 162.33 +/- 27.88 U/L (P < 0.01), monoclonal antibody against ICAM-1 (ICAM-1 Mab) could partially block the adherence of frozen/thawed VEC to PMN (0.270 +/- 0.021, P < 0.01), and diminish LDH activity in nutrient solution (125.39 +/- 22.26 U/L, P < 0.05).

CONCLUSIONThe freezing/thawing of VEC can elicit an increase in ICAM-1 expression on the surface of VEC, and then proceed to VEC-PMN adherence and lead to VEC injury.

Animals ; Cells, Cultured ; Endothelial Cells ; metabolism ; Endothelium, Vascular ; cytology ; Freezing ; Intercellular Adhesion Molecule-1 ; metabolism ; Neutrophils ; cytology ; Rats

OBJECTIVETo explore and study the relationships between the popularity of HFMD and the climate in Qinhuangdao city.

METHODSHFMD cases were collected on a ten-day basis in 2009 in Qinhuangdao city. At the same time, the data about Qinhuangdao's ten-day average temperature and average humidity were provided by the Qinhuangdao Meteorological bureau. Then the collected data were analysed using the great data analysis function in the EXCELE software.

RESULTSThe results showed that the disease of HFMD had a positive relationship with seasons. The cases of HFMD began to rise at the last ten days of March and rised dramatically at the middle ten days of April; In July, the cases of HFMD arrived at peak and then decline gradually. The cases of HFMD in October were quite similar to the cases of HFMD in March. Then in November, the cases of HFMD declined rapidly. All these evidences suggested that the peak seasons of HFMD were Spring and Summer.

CONCLUSIONThe situations of HFMD had a significant positive relationship with the conditions of climate, such as high temperature and high humidity.

Climate ; Hand, Foot and Mouth Disease ; epidemiology ; Humans ; Humidity ; Seasons ; Temperature

Computer Graphics ; Computer-Assisted Instruction ; Forensic Pathology ; Humans ; Imaging, Three-Dimensional ; Pathology ; education ; Pathology, Clinical ; Specimen Handling ; methods

AIMIn order to study airway rewarming method and rewarming devices for hypothermia, hypothermic dog model was established.

METHODSThe anesthetized dog was immersed in cold water at 16.7 degrees C until the esophageal temperature (Te) of the dog decreased to 34.0 degrees C, the core temperature and skin temperature were monitored by using a 12-channel scanning thermometers. Atracurium besylate, a skeletal muscle relaxant, was injected intravenously when the core temperature of the dog was basically steady after the dog was out of the cold water, the hypothermic dog model was established.

RESULTSRectal and esophageal temperature could stand for the core temperature of the hypothermic dog model, but mixing with each other was prohibited because of leading to mistakes. Administering of atracurium besylate could eliminate the effect of shivering on airway rewarming alone, hypothermic dog model in which shivering was inhibited could be used in determination of airway rewarming technique and rewarming devices for hypothermia.

CONCLUSIONHypothermic dog model in which shivering was inhibited can abolish the interference of shivering, experimental repeatability is good, experimental method quite simple, and the model appropriate for application and dissemination.

Animals ; Body Temperature ; Cold Temperature ; Disease Models, Animal ; Dogs ; Hypothermia ; therapy ; Hypothermia, Induced ; Male ; Respiratory System ; Rewarming ; methods ; Shivering

OBJECTIVETo study the clinical outcome, adverse effect and treatment cost of homoharringtonine (HHT) in combination with all-trans retinoic acid (ATRA) and arsenic trioxide (AS2O3) for newly diagnosed with patients acute promyelocytic leukemia (APL).

METHODSClinical data of treatment of newly diagnosed patients with APL in experimental group (HHT + ATRA + AS2O3, n = 14) and control group \[Idarubicin (IDA) + ATRA + AS2O3, n = 21\] were analyzed retrospectively. The therapeutic effects, side effects and costs during induction therapy were compared between the two groups.

RESULTS(1) The complete remission (CR) rate were 92.9% (13/14) and 95.2% (20/21) in experimental group and control group, respectively. The time to achieve CR were (28.1 ± 3.8) and (31.7 ± 4.2) days, respectively (P > 0.05). The negative rate of PML-RARα fusion gene at the time of CR were 76.9% (10/13) and 75.0% (15/20), respectively, and that in CR patient at the end of the first cycle treatment were 100.0% (13/13) and 95.0% (19/20), respectively (P > 0.05). (2) 5-year overall survival (OS) rate were (92.6 ± 0.6)% and (89.9 ± 0.5)%, respectively (P > 0.05), 5-year disease free survival (DFS) rate were 100.0% and (86.8 ± 0.6)%, respectively (P > 0.05). (3) During induction therapy, the incidence of infection in experimental and control group were 23.1% (3/13), 60.0% (12/20), respectively (P < 0.05). The amount of platelet transfusion were (54.7 ± 29.6) and (76.5 ± 25.6) units, respectively (P > 0.05), and that of fresh frozen plasma were (1157.1 ± 238.4) and (1423.5 ± 324.6) ml, respectively (P > 0.05). The total medical costs (excluding HHT and IDA) in experimental and control group were (36074.9 ± 1245.6) and (50564.5 ± 3658.4)CNY, respectively (P < 0.05).

CONCLUSIONHHT in combination with ATRA and AS2O3 regimen for newly diagnosed APL has a better efficacy, a higher long-term survival rate, and a lower costs, which is one of the reasonable choice.

Antineoplastic Combined Chemotherapy Protocols ; therapeutic use ; Arsenicals ; therapeutic use ; Female ; Harringtonines ; therapeutic use ; Humans ; Leukemia, Promyelocytic, Acute ; drug therapy ; Male ; Middle Aged ; Oxides ; therapeutic use ; Retrospective Studies ; Treatment Outcome ; Tretinoin ; therapeutic use

OBJECTIVETo investigate the effect of farnesoid-X-receptor (FXR) antagonist Z-guggulsterone in an in vivo high-fat fed apolipoprotein E knockout (ApoE(-/-)) mice model of myocardial ischemia/reperfusion (I/R).

METHODSMale ApoE(-/-) mice were randomly divided into three groups: standard ApoE(-/-) group (fed with standard mouse diet for 12 weeks before myocardial I/R procedure, n = 18), high-fat ApoE(-/-) group (fed with high-fat mouse diet for 12 weeks before myocardial I/R procedure, n = 22), and high-fat ApoE(-/-) + FXR antagonist group(fed with high-fat mouse diet for 12 weeks and received FXR antagonist Z-Guggulsterone 30 minutes before myocardial I/R procedure, n = 17). The expression of FXR was detected by real-time quantitative-PCR. Myocardial infarct size was determined by Evans blue/TTC double staining methods. Myocardial apoptosis was determined by in situ TUNEL technique. Markers of the mitochondrial-mediated apoptotic pathway (cytochrome c release, caspase-9 activity, and BAX and BCL-2 levels), endoplasmic reticulum stress apoptotic pathway (caspase-12 activity and CHOP level), and death receptor apoptotic pathway (caspase-8 activity, and Fas and FasL levels) were also measured.

RESULTFXR expression (3.7-fold higher, P < 0.01), myocardial infarct size [(62.1 ± 7.0)% vs. (33.8 ± 5.8)%, P < 0.01] and myocardial apoptosis index[ (36.8 ± 5.7)% vs. (17.2 ± 3.8)%, P < 0.01]were all significantly higher in high-fat ApoE(-/-) group than those in standard ApoE(-/-) group. Compared with high-fat ApoE(-/-) group, myocardial infarct size [(24.4 ± 4.7)% vs. (62.1 ± 7.0)%, P < 0.01] and myocardial apoptosis index [(13.8 ± 2.7)% vs. (36.8 ± 5.7)%, P < 0.01] were significantly reduced in high-fat ApoE(-/-) + FXR antagonist group. Moreover, levels of mitochondrial-mediated apoptotic pathway markers (cytochrome c release, caspase-9 activity, and BAX/BCL-2 levels) and endoplasmic reticulum stress apoptotic pathway markers (caspase-12 activity and CHOP level) were significantly lower in high-fat ApoE(-/-) + FXR antagonist group than those in high-fat ApoE(-/-) group (all P < 0.01). Levels of death receptor apoptotic pathway markers (caspase-8 activity, and Fas and FasL levels) were similar between high-fat ApoE(-/-) group and high-fat ApoE(-/-) + FXR antagonist group.

CONCLUSIONFXR antagonist alleviates myocardial reperfusion injury in cholesterol-fed ApoE(-/-) mice via inhibition of the mitochondrial-mediated and endoplasmic-reticulum stress pathway.

Animals ; Apolipoproteins E ; genetics ; Apoptosis ; drug effects ; Caspase 9 ; metabolism ; Cholesterol, Dietary ; administration & dosage ; Cytochromes c ; metabolism ; Disease Models, Animal ; Endoplasmic Reticulum Stress ; Male ; Mice ; Mice, Knockout ; Myocardial Reperfusion Injury ; metabolism ; pathology ; prevention & control ; Pregnenediones ; pharmacology ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Receptors, Cytoplasmic and Nuclear ; antagonists & inhibitors ; metabolism ; bcl-2-Associated X Protein ; metabolism