Objective:To analyze the risk factors of bronchopulmonary dysplasia(BPD)in very preterm infants(VPI), and to provide scientific basis for the prevention and treatment of BPD in VPI.Methods:A prospective multicenter study was designed to collect the clinical data of VPI in department of neonatology of 28 hospitals in 7 regions from September 2019 to December 2020.According to the continuous oxygen dependence at 28 days after birth, VPI were divided into non BPD group and BPD group, and the risk factors of BPD in VPI were analyzed.Results:A total of 2 514 cases of VPI including 1 364 cases without BPD and 1 150 cases with BPD were enrolled.The incidence of BPD was 45.7%.The smaller the gestational age and weight, the higher the incidence of BPD( P<0.001). Compared with non BPD group, the average birth age, weight and cesarean section rate in BPD group were lower, and the incidence of male infants, small for gestational age and 5-minute apgar score≤7 were higher( P<0.01). In BPD group, the incidences of neonatal respiratory distress syndrome(NRDS), hemodynamically significant patent ductus arteriosus, retinopathy of prematurity, feeding intolerance, extrauterine growth restriction, grade Ⅲ~Ⅳ intracranial hemorrhage, anemia, early-onset and late-onset sepsis, nosocomial infection, parenteral nutrition-associated cholestasis were higher( P<0.05), the use of pulmonary surfactant(PS), postnatal hormone exposure, anemia and blood transfusion were also higher, and the time of invasive and non-invasive mechanical ventilation, oxygen use and total hospital stay were longer( P<0.001). The time of starting enteral nutrition, cumulative fasting days, days of reaching total enteral nutrition, days of continuous parenteral nutrition, days of reaching 110 kcal/(kg·d) total calorie, days of reaching 110 kcal/(kg·d) oral calorie were longer and the breastfeeding rate was lower in BPD group than those in non BPD group( P<0.001). The cumulative doses of amino acid and fat emulsion during the first week of hospitalization were higher in BPD group( P<0.001). Multivariate Logistic regression analysis showed that NRDS, invasive mechanical ventilation, age of reaching total enteral nutrition, anemia and blood transfusion were the independent risk factors for BPD in VPI, and older gestational age was the protective factor for BPD. Conclusion:Strengthening perinatal management, avoiding premature delivery and severe NRDS, shortening the time of invasive mechanical ventilation, paying attention to enteral nutrition management, reaching whole intestinal feeding as soon as possible, and strictly mastering the indications of blood transfusion are very important to reduce the incidence of BPD in VPI.

Objective To study the effect of noise pollution on serum hormone and heat shock protein-70(Hsp-70)levels in rats. Methods Forty male Wistar rats were randomly divided into control group(normal), experimental group(further divided into 35,65 and 85 dB three groups), each group 10 animals, stimulated for 30 min once a day, continually stimulated for consecutive 20 days. On the 21st day of experiment,the serum noradrenaline(NA),testosterone (T),dopamine(DA)and Hsp-70 levels were determined by enzyme-linked immunosorbent assay(ELISA). Results Compared with the control group, the body weight of experimental group(35, 65 and 85 dB groups)was reduced by 23.45%,30.13%, and 35.64%, respectively The serum T and DA levels were decreased by 9.12%, 20.06%, 37.99% and 15.49%, 8.31%, 24.88%, respectively; while the serum NA and Hsp-70 levels were increased by 35.08%, 171.52%,197.86%, and 39.34%, 195.09%, and 285.25%, respectively. All the result showed a significant difference(P<0.01). Conclusions Noise pollution can significantly affect the serum levels of hormone and heat shock protein-70 expression in rats.

Objective To study the effect of maca extract on sport fatigue and its antioxidant effect.Methods 50 healthy male Wistar rats were randomly divided into control group (normal breeding,without swimming,equal amount of distilled water for gavage),simple swimming group (swimming,equal amount of distilled water for gavage),swimming and medicine group (divided into maca extract 4.0,8.0 and 16.0 g/(kg· bw) groups,respectively),10 rats in each group.All rats were freely swimming in the circulating water flow daily for 15 days.On the 16th day of experiment,liver tissue samples were collected.The liver lipid peroxide (LPO),superoxide dismutase (SOD),glutathione peroxidase (GSH-Px) and liver glycogen level were determined.Results When rats were administered with maca extract at the doses of 4.0,8.0,16.0 g/(kg· bw),respectively,the swimming time before sinking and the total swimming time were increased by 18.99%,64.46% and 90.69%,and 18.99%,56.23% and 94.72%,respectively,while the numbers of times of sinking were decreased by 27.44%,42.86%,64.11% (P<0.01),respectively,compared with the swimming rats without maca extract treatment.The LPO content in the liver of rats treated with maca extract 4.0,8.0,16.0 g/(kg· bw) were reduced by 31.31%,42.00% and 31.31%,respectively,while the levels of SOD,GSH-Px and liver glycogen were enhanced by 25.92%,31.82%,62.09%,12.33%,23.01%,46.36% and 17.83%,44.69%,62.99%,respectively,over those of rats without maca extract treatment.Conclusions Maca extract reduces the liver LPO level,increases liver glycogen level,improves the SOD and GSH-Px activity,therefore,plays a protective role in sport fatigue.

Objective To study the effect of low frequency electrical stimulation on hormone levels in organs of Chinese tree shrews after death.Methods Giving Chinese tree shrews low frequency electrical stimulation.At 0 h, 3 h, 6 h, 12 h, 18 h, 24 h, 36 h and 72 h after death, the thyroid, liver, spleen were taken,and the levels of endothelin (ET), atrial natriuretic factor( ANF) , thromboxane ( TX) were determined by RIA method.At 0 h after death, midbrain ventral tegmental area ( VTA) of Chinese tree shrews was taken to detect the c-fos expression.Results After electrical stimula-tion, ET, ANF, TX levels in the cadaver organs and VTA c-fos expression of Chinese tree shrews were significantly in-creased than in the control group.The contents were decreasing with the time after death.Conclusions Low frequency e-lectrical stimulation can induce the synthesis and release of hormones in organs and c-fos expression in brain tissue of Chi-nese tree shrews.

Objective To study the effect of low frequency electrical stimulation on blood hormone levels in differ -ent animals.Methods At 12 h, 24 h and 36 h after low frequency electrical stimulation to Chinese tree shrews , Wistar rats, and BALB/c mice, respectively, the blood noradrenaline (NA) and endothelin (ET) levels were determined by ra-dioimmunoassay ( RIA) .Results The blood NA and ET levels of electrical stimulation group were significantly higher than that in the control group (P <0.01).At 24 h after reserpine treatment, the same electrical stimulation was given. The NA, ET levels were significantly decreased compared with that in the electrical stimulation group (P<0.05 to 0.01). Different animals responded to the same electric stimulus differently , following the order of Chinese tree shrews >Wistar rats >BALB/c mice.Conclusions Low frequency electrical stimulation can promote the release of noradrenaline and en -dothelin in Chinese tree shrews , Wistar rats and BALB/c mice.Reserpine can reduce the stress induced by low frequency electric stimulation to the body .

BACKGROUND: Diabetic wounds are a major clinical challenge, because minor skin wounds can lead to chronic, unhealed ulcers and ultimately result in infection, gangrene, or even amputation. Studies on bone marrow derived mesenchymal stem cells (BMSCs) and a series of growth factors have revealed their many benefits for wound healing and regeneration. Platelet-rich plasma (PRP) may improve the environment for BMSC development and differentiation. However, whether combined use of BMSCs and PRP may be more effective for accelerating diabetic ulcer healing remains unclear. OBJECTIVE: We investigated the efficacy of BMSCs and PRP for the repair of refractory wound healing in a diabetic rat model. METHODS: Forty-eight rats with diabetes mellitus induced by streptozotocin were divided into four groups: treatment with BMSCs plus PRP, BMSCs alone, PRP alone, phosphate buffered saline. The rate of wound closure was quantified. A histopathological study was conducted regarding wound depth and the skin edge at 7, 14, and 28 days after surgery. RESULTS: Wound healing rates were significantly higher in the BMSC plus PRP group than in the other groups. The immunohistochemistry results showed that the expression of platelet/endothelial cell adhesion molecule 1, proliferating cell nuclear antigen, and transforming growth factor-beta1 increased significantly in the BMSC plus PRP group compared to the other treatment groups. On day 7, CD68 expression increased significantly in the wounds of the BMSC plus PRP group, but decreased markedly at day 14 compared to the controls. CONCLUSION: The combination of BMSCs and PRP aids diabetic wound repair and regeneration.
Amputation ; Animals ; Bone Marrow ; Cell Adhesion ; Diabetes Mellitus ; Gangrene ; Immunohistochemistry ; Intercellular Signaling Peptides and Proteins ; Mesenchymal Stromal Cells* ; Models, Animal ; Platelet-Rich Plasma* ; Proliferating Cell Nuclear Antigen ; Rats* ; Regeneration ; Skin ; Streptozocin ; Ulcer ; Wound Healing ; Wounds and Injuries

Objective To study the effects of living environment conditions and animal-animal interaction on the blood hormone levels and psychological behavior in Chinese tree shrews .Methods Chinese tree shrews were raised in ca-ges of different space sizes or were administered reserpine for 15, 30, 60, 120, 180 days, respectively.Then the animals were anesthetized by ether inhalation , and blood samples were taken from the heart to detect the levels of blood testosterone (T), estradiol (E2), endothelin (ET), adrenaline (A) and noradrenaline (NA) by radioimmunoassay (RIA).Results 1.Chinese tree shrews were bred in large cage (D1group) or small cage (X1 group) for 15, 30, 60, 120, 180 days, re-spectively.Compared with the animals bred in the large cage (D1 group), the level of blood testosterone (T) was signifi-cantly reduced (P<0.01), and the levels of adrenaline , noradrenaline and endothelin were significantly increased in the small cage group (P<0.01 for all).2.The animals raised in small cages in close neighborhood with large cages for 15, 30, 60, 120, 180 days, respectively.The levels of testosterone, adrenaline and noradrenaline in the large cage group (X2 group) were significantly higher than those of the small cage group (X1 group) (P<0.01 for all).3.The adrenaline and noradrenaline levels were significantly lower in all the reserpine groups (P<0.01 for all).4.The animals bred in small cages (X1 group) and in small cages in close neighborhood with large cages showed sudden loss , reduced appetite, testicu-lar atrophy , penile prolapse and stress symptoms .The animals of the reserpine groups appeared gentle temperament , signif-icantly reduced activity and reduced appetite .However , after stopping the reserpine administration and feeding them in large cages , the animals gradually returned to normal behavior .Conclusion Both animals living environment conditions and animal-animal interaction may cause changes of blood hormone levels and psychological behavior in Chinese tree shrews.

Objective To study the anti-fatigue effect of Cynomorium songaricum flavone(CSF)on old rats.Methods50 old male Wistar rats were randomly divided into the control group(no swimming,no drugs),single swimming group(swimming,given saline by gavage),and three swimming plus CSF groups(swimming,given CSF 20 g/kg weight,10 g/kg weight and 5 g/kg weight respectively),total five groups with 10 animals in each group.Animals swam with free swimming in endless cycles water 30 minutes once every day for 10 days.The level of monoamine oxidase(MAO) and glutathione peroxidase(GSH-px) in blood of animals were examined by MAO kit,GSH-px kit and ultraviolet spectrophotometer at 11th day.ResultsCompared with single swimming group,the body weights of swimming plus CSF groups increased significantly by 12.9%,80.6% and 200% respectively(P<0.01);swimming times before sinking increased by 19.4%,29% and 48.4%;sinking times of each rat(time/10 min) decreased by 17.8%,43.2% and 72.9%;total swimming times increased by 2.8%,7% and 29.6% respectively(P<0.01);MAO decreased by 60%,69.8% and 80.5%,GSH-px increased by 465.3%,563.8% and 635% respectively(P<0.01).ConclusionCSF shows anti-oxidative and anti-fatigue properties and can be given as prophylactic/therapeutic supplements for increasing antioxidant enzyme activities and preventing lipid peroxidation during strenuous exercise.

BACKGROUND: The stress can induce sympathic nervous-adrenalmedulla system to release a lot of noradrenalin(NE) and adrenalin(E),pro mote bone marrow hemopoietic stem cells to differentiate towards lympho cyte and plasmocyte,decrease the number of granulocyte,thus organism canadapt to surrounding stress,so as to protect critical organs from damage. OBJECTIVE: To observe effect of confinement and vibration stress on in dexes of hematology and myelogram in Chinese tree shrews. DESIGN: Sex-marched and controlled experiment. MATERIALS: Thirty Chinese tree shrews (15 females, 15 males) weigh ing 120 g to 140 g were selected. Self-made experimental cylinders withmany vent-holes, 16 cm length and 6cm inside diameter,were used, one sideof which was sealed with plexglass,and the other side was blocked by mov able plexiglass for animals in and out.The air bath and homothermal vibra tor(Type SHZ-82,made in Changzhou,China). METHODS: The experiment was completed at the Experimental Center ofPublic Security, Gansu Political Science and Law Institute from March toOctober in 2003. ①Thirty Chinese tree shrews were randomly divided intofive groups(n=6):The animals in the control group(C group) were fed nor mally; The experimental groups consisted of reserpine + vibration and vi bration groups. The animals in the reserpine + vibration (R+V)group wereadministered reserpine (0.05 mg/kg, im.) and vibrated at 140 beats/min; the vibration groups (V1,V2,V3) were vibrated at 70, 140, 210 beats/min, respectively. ② The animals in experimental groups were individually keptin the experimental tubes for 5 minutes, then put the tubes into the air bath and homothermal vibrator for 2 minutes. ③ The bleeding time, bloodsedimentation, clotting time, and indexes of hemogram were determinedwith the methods of Duke, Westergren, glass capillary, and full-automaticbiochemical instruments (type 721, Japan), respectively. ④ Dunnett ANO- VA was used to compare the differences between groups . MAIN OUTCOME MEASURES: Comparison of indexes of hematologyand myelogram in Chinese tree shrews betweem the four groups.RESULTS: Thirty Chinese tree shrews were involved in the final analysis.① Indexes of hematology: compared with those of C group, the bleeding time of the V2 group significantly prolonged by 104.8% (P＜0.01 ),but the clotting time and blood sedimentation decreased by 37.3% and 7.5% (P＜0.01 ), respectively. Also, the counts of red blood cells, reticulocyte, blood platelet and white blood cells,as well as content of hemoglobin increased by i7.5% ,50.9%, 11.8%, 10.3% and 13.7% ,respectively.There was no significant difference between R+V group and C group(P ＞0.05),and also in various vibration groups. ②Indexes of myelogram:compared with those of C group,counts of granulocyte were decreased by 31.5%(P＜0.01),counts of red cells,lymphocyte,mononuelear,plasmocyte,megakaryocyte,mitotic cells increased by 25.7% ,77.6%,213.3% ,65.8% ,100%,161.3%,respectively (P＜0.01); those in R+V group were similar to C group (P＞0.05); There were no significant differences among various vibration groups(P＞0.05).CONCLUSION: Confinement and vibration stress can increase significantly the blood cells and reduce counts of granulocyte in bone marrow,and the above changes can be interfered by reserpine.

AIM To study the inhibitory effect and mechanism of n itrary flavone in Hep and U 14 tumor. METHODS The Hep or U 14 tumor cells were injected in the armpit subcutaneous layer of right foreleg of BALB/c strain mice. After 24 h,nitrary flavone at a does of 100 mg?kg -1 ?d -1 body weight or combine nitrary flavone with 5-Fu(100 mg?kg -1 ?d -1 body weight)was given (ip) and inhibitory rate of nitrary flavone for transplanted tumor and the immune function of mice were determined. RESULTS Administration of nitrary flavone to mice for 10 consecutive days exhibited significantly the inhibitory rate for Hep and U 14 by 34 11%,32 14% and 50 73%,47 22%,respectively, as well as the weight of immune organs of mice, formation value of serolysin and phagociytic index were significantly enhanced(P