BACKGROUND:The plateau environment affects the immune function and metabolic status of patients with osteomyelitis,leading to acceleration or complication of the disease process.The construction of effective and stable animal models of chronic osteomyelitis is essential for experimental studies of chronic osteomyelitis.OBJECTIVE:To establish a sheep model of chronic osteomyelitis in plateau regions for toxicity assessment and therapeutic research.METHODS:Fifteen healthy sheep were selected in this study.Sodium morrhuate and Staphylococcus aureus suspension were injected into the medullary cavity of the middle segment of the tibia to establish the chronic osteomyelitis model.General observation,body mass and temperature monitoring,blood infection index detection,radiological scoring,and microbial culture were performed for evaluation and analysis.RESULTS AND CONCLUSION:(1)Local tissue swelling and lameness of the affected leg were observed in all sheep in the early stage after modeling,accompanied by varying degrees of anorexia.A slight decrease in body mass was observed in sheep 1 week after modeling,while no significant changes in body temperature were observed.(2)The erythrocyte sedimentation rate significantly accelerated 4 days after modeling(P<0.05)and gradually returned to normal levels after 1 month.The white blood cell count showed a significant increase within 4 days after modeling and returned to normal after 1 week.The level of C-reactive protein increased significantly after modeling(P<0.05)and remained significantly higher than normal until the end of the experiment(P<0.05).(3)Fifteen sheep exhibited typical radiological manifestations of osteomyelitis,including unclear boundaries,irregular osteolytic lesions,and low-density bright absorption areas with interspersed necrotic bone fragments of increased and uneven density.Different degrees of periosteal reaction were observed in the cortex near the lesion.(4)Thirteen sheep were cultured for a single strain of Staphylococcus aureus,while two sheep were cultured for Staphylococcus aureus and Escherichia coli.These findings indicate that a reliable chronic osteomyelitis animal model of sheep tibia can be successfully established in plateau regions by injecting an appropriate amount of Staphylococcus aureus suspension into the medullary cavity of sheep,combined with local implantation of foreign cotton thread and sodium morrhuate.

BACKGROUND:The plateau environment affects the immune function and metabolic status of patients with osteomyelitis,leading to acceleration or complication of the disease process.The construction of effective and stable animal models of chronic osteomyelitis is essential for experimental studies of chronic osteomyelitis.OBJECTIVE:To establish a sheep model of chronic osteomyelitis in plateau regions for toxicity assessment and therapeutic research.METHODS:Fifteen healthy sheep were selected in this study.Sodium morrhuate and Staphylococcus aureus suspension were injected into the medullary cavity of the middle segment of the tibia to establish the chronic osteomyelitis model.General observation,body mass and temperature monitoring,blood infection index detection,radiological scoring,and microbial culture were performed for evaluation and analysis.RESULTS AND CONCLUSION:(1)Local tissue swelling and lameness of the affected leg were observed in all sheep in the early stage after modeling,accompanied by varying degrees of anorexia.A slight decrease in body mass was observed in sheep 1 week after modeling,while no significant changes in body temperature were observed.(2)The erythrocyte sedimentation rate significantly accelerated 4 days after modeling(P<0.05)and gradually returned to normal levels after 1 month.The white blood cell count showed a significant increase within 4 days after modeling and returned to normal after 1 week.The level of C-reactive protein increased significantly after modeling(P<0.05)and remained significantly higher than normal until the end of the experiment(P<0.05).(3)Fifteen sheep exhibited typical radiological manifestations of osteomyelitis,including unclear boundaries,irregular osteolytic lesions,and low-density bright absorption areas with interspersed necrotic bone fragments of increased and uneven density.Different degrees of periosteal reaction were observed in the cortex near the lesion.(4)Thirteen sheep were cultured for a single strain of Staphylococcus aureus,while two sheep were cultured for Staphylococcus aureus and Escherichia coli.These findings indicate that a reliable chronic osteomyelitis animal model of sheep tibia can be successfully established in plateau regions by injecting an appropriate amount of Staphylococcus aureus suspension into the medullary cavity of sheep,combined with local implantation of foreign cotton thread and sodium morrhuate.

Objective:To compare the effects of leukocyte-poor platelet-rich plasma (Lp-PRP) and leukocyte-rich platelet-rich plasma (Lr-PRP) on dorsal wound healing in rats.Methods:Thirty-six male Sprague-Dawley rats were randomly divided into Lp-PRP group, Lr-PRP group and control group, each containing twelve rats. Venous blood was drawn and the Lp-PRP and Lr-PRP were prepared separately using a centrifugal method. Circular full-thickness skin defect wounds (15 mm in diameter) were created on the backs of the rats in the three groups. The wounds were then treated with 100 μl Lp-PRP, Lr-PRP and saline, respectively. At 7 and 14 days post-operation, the wounds were photographed, and Image J software was used to calculate the wound area rate (postoperative wound area/wound area at modeling time × 100%). At 14 days post-operation, the total neo-epithelium length and collagen deposition rate of the wounds were evaluated using HE and Masson staining, respectively. At 7 days post-operation, the relative expression of vascular endothelial growth factor (VEGF) in the wounds was detected by Western blotting, and the number of CD31 positive microvessels in the wounds was examined by immunohistochemistry. Statistical analysis was performed using SPSS 28.0. One-way analysis of variance (ANOVA) was used to compare the three groups, and Tukey’s test was used for pairwise comparisons. A significance level of P<0.05 was considered statistically significant. Results:Blood analysis revealed that the platelet concentrations in the prepared Lp-PRP and Lr-PRP were 4.1 times and 4.5 times that of whole blood, respectively ( P<0.01), with no significant difference between the two PRPs ( P>0.05). The leukocyte concentration in Lp-PRP was undetectable, while in Lr-PRP, it was 3.5 times that of whole blood ( P<0.01). The wound area rate at 7 and 14 days post-operation, the total neo-epithelium length and collagen deposition rate at 14 days post-operation, as well as the relative expression of VEGF and the number of CD31-positive microvessels at 7 days post-operation in the Lp-PRP and Lr-PRP groups were superior to those in the control group (all P<0.01). However, there was no significant difference between the two PRP groups (all P>0.05). Conclusion:Both Lp-PRP and Lr-PRP promote dorsal wound healing in rats by enhancing re-epithelialization, collagen deposition, and angiogenesis. The impacts of Lp-PRP and Lr-PRP on promoting wound healing are comparable and not influenced by the presence of leukocytes in PRPs.

Objective:To compare the effects of leukocyte-poor platelet-rich plasma (Lp-PRP) and leukocyte-rich platelet-rich plasma (Lr-PRP) on dorsal wound healing in rats.Methods:Thirty-six male Sprague-Dawley rats were randomly divided into Lp-PRP group, Lr-PRP group and control group, each containing twelve rats. Venous blood was drawn and the Lp-PRP and Lr-PRP were prepared separately using a centrifugal method. Circular full-thickness skin defect wounds (15 mm in diameter) were created on the backs of the rats in the three groups. The wounds were then treated with 100 μl Lp-PRP, Lr-PRP and saline, respectively. At 7 and 14 days post-operation, the wounds were photographed, and Image J software was used to calculate the wound area rate (postoperative wound area/wound area at modeling time × 100%). At 14 days post-operation, the total neo-epithelium length and collagen deposition rate of the wounds were evaluated using HE and Masson staining, respectively. At 7 days post-operation, the relative expression of vascular endothelial growth factor (VEGF) in the wounds was detected by Western blotting, and the number of CD31 positive microvessels in the wounds was examined by immunohistochemistry. Statistical analysis was performed using SPSS 28.0. One-way analysis of variance (ANOVA) was used to compare the three groups, and Tukey’s test was used for pairwise comparisons. A significance level of P<0.05 was considered statistically significant. Results:Blood analysis revealed that the platelet concentrations in the prepared Lp-PRP and Lr-PRP were 4.1 times and 4.5 times that of whole blood, respectively ( P<0.01), with no significant difference between the two PRPs ( P>0.05). The leukocyte concentration in Lp-PRP was undetectable, while in Lr-PRP, it was 3.5 times that of whole blood ( P<0.01). The wound area rate at 7 and 14 days post-operation, the total neo-epithelium length and collagen deposition rate at 14 days post-operation, as well as the relative expression of VEGF and the number of CD31-positive microvessels at 7 days post-operation in the Lp-PRP and Lr-PRP groups were superior to those in the control group (all P<0.01). However, there was no significant difference between the two PRP groups (all P>0.05). Conclusion:Both Lp-PRP and Lr-PRP promote dorsal wound healing in rats by enhancing re-epithelialization, collagen deposition, and angiogenesis. The impacts of Lp-PRP and Lr-PRP on promoting wound healing are comparable and not influenced by the presence of leukocytes in PRPs.

Anterior cruciate ligament(ACL)injury is caused by strong violence,which can destabilize the knee joint,cause joint cartilage degeneration,meniscus injury,and in severe cases,develop osteoarthropathy.The gold standard for the treatment of ACLR injuries at this stage is arthroscopic anterior cruciate ligament recon-struction(ACLR).In clinical practice,the LARS(Ligament advanced reinforcement system)artificial ligament made of polyethylene terephthalate(PET)as the material has a good effect in the short and medium term,but the long-term biological healing between the graft and the host bone is poor,and the real"ligamentization"requirement of the postoperative graft cannot be met.Coating-modified modification of artificial ligaments can improve their hydrophilicity and biocompatibility,which in turn can promote the healing of graft-bone tunnels.Tendon bone healing is a bone-derived progressive process from indirect insertion to direct insertion,which takes a relatively long time and is closely related to the prognosis and early rehabilitation effect of patients.This article reviews the progress of superficial modification of artificial ligaments to promote ACLR tendon bone healing.

Objective:To explore the relationship between the maternal dietary patterns during pregnancy and the early childhood BMI change trajectory.Methods:The subjects were 1 241 pairs of pregnant women and their children in Ma'anshan maternal and infant health cohort. The food frequency questionnaire was used to collect the maternal diet data during pregnancy. The cohort children were followed up at birth, month 3, 6, 12, 18 and 24, respectively. The body height and weight data of the cohort children were collected. The principal component analysis was used to determine the categories of maternal dietary patterns during pregnancy, group-based multi-trajectory modeling was used to fit the early childhood BMI change trajectory, and the multiple classification logistic regression model was used to evaluate the relationship between the maternal dietary patterns during pregnancy and the early childhood BMI change trajectory.Results:The maternal dietary patterns during pregnancy included protein type, healthy type, vegetarian type, processing type and beverage type, which could explain 50.04% of the total dietary variation. Among them, the protein type, main dietary pattern, could explain 21.34% of the total dietary variation. The early childhood BMI change trajectory was from thinnish stature to average stature, then to mild obesity, accounting for 42.9%, 45.6% and 11.5% respectively. After controlling the potential confounding factors, it was found that there was a statistical correlation between healthy type and beverage type of maternal dietary patterns during pregnancy and early childhood BMI change trajectory ( P<0.05). Comparison of change trajectories between thinnish type and average stature type, children in the low-level group of healthy diet pattern tended to have a thinnish type change trajectory in early life ( OR=1.286, 95% CI: 1.002-1.651). Comparison of change trajectories between mild obesity type and average stature type, children in the high-level group of beverage diet pattern tended to have a mild obesity type change trajectory in early life ( OR=0.565, 95% CI: 0.342-0.935). The other dietary patterns had no statistical correlation with the early childhood BMI change trajectory. Conclusions:Maternal dietary patterns during pregnancy can affect the early childhood BMI change trajectory, and the low-level healthy type diet is an independent risk factor for thinnish type change trajectory, and the high-level beverage type diet is an independent risk factor for the mild obesity type change trajectory.

Objective:To explore the effect of distal veins on the survival of a dorsal four-territory perforator flap in rats.Methods:A total of 32 SD rats were randomly divided into the control group and the experimental group, with 16 rats in each group. The multi-territory perforator flap including the bilateral iliolumbar and bilateral posterior intercostal angiosomes was cut from the back of each rat, with the size of 6 cm×7 cm. The right iliolumbar artery and vein were preserved in the control group, while the right iliolumbar artery and the right posterior intercostal vein were preserved in the experimental group. In both groups, incisions were made between the right iliolumbar angiosome and the right posterior intercostal angiosome. Finally, the flap was sutured back to their orthotopic site. At 6 hours and 1, 3, 5, 7 days after surgery, the blood perfusion at the bilateral iliolumbar and the left posterior intercostal vascular territories were measured. On the seventh day after surgery, the percentage of the survived area of the flaps were evaluated, arteriography was performed to observe the dilation of arteries within the flap, the intraluminal diameter of the choke artery in the choke 2 area was measured using hematoxylin and eosin staining, and the relative expression of endothelial nitric oxide synthase (eNOS) was detected by Western blotting. SPSS 28.0 was used for statistical analysis, and measurement data were presented as Mean±SD. Independent sample t-test was used to compare data across two groups. P<0.05 was considered statistically significant. Results:(1) At 6 hours and 1, 3, 5, 7 days after surgery, the experimental group displayed higher blood perfusion than the control group at the bilateral iliolumbar and the left posterior intercostal vascular territories (all P<0.01). (2) On the 7th day after surgery, the artery dilation of the experimental group was more obvious than that of the control group; the percentage of the survived flap area in the experimental group was higher than that in the control group [(87.6±3.2)% vs. (65.3±3.0)%, P<0.01]; the intraluminal diameter of the choke artery was greater in the experimental group than that in the control group[(49.3±3.1) μm vs. (35.1±2.3) μm, P<0.01]; and the relative expression of eNOS in the experimental group was higher than that in the control group (0.87±0.07 vs. 0.50±0.05, P<0.01). Conclusion:The distal vein (right posterior intercostal vein) of dorsal four-territory perforator flap of SD rats directly guided the pedicle artery blood supply to promote the expression of eNOS, dilated the arteries in each zone of the flap, increased the blood supply to the distal artery of the flap, and ultimately enhanced the flap survival area.

Objective:To explore the effect of distal veins on the survival of a dorsal four-territory perforator flap in rats.Methods:A total of 32 SD rats were randomly divided into the control group and the experimental group, with 16 rats in each group. The multi-territory perforator flap including the bilateral iliolumbar and bilateral posterior intercostal angiosomes was cut from the back of each rat, with the size of 6 cm×7 cm. The right iliolumbar artery and vein were preserved in the control group, while the right iliolumbar artery and the right posterior intercostal vein were preserved in the experimental group. In both groups, incisions were made between the right iliolumbar angiosome and the right posterior intercostal angiosome. Finally, the flap was sutured back to their orthotopic site. At 6 hours and 1, 3, 5, 7 days after surgery, the blood perfusion at the bilateral iliolumbar and the left posterior intercostal vascular territories were measured. On the seventh day after surgery, the percentage of the survived area of the flaps were evaluated, arteriography was performed to observe the dilation of arteries within the flap, the intraluminal diameter of the choke artery in the choke 2 area was measured using hematoxylin and eosin staining, and the relative expression of endothelial nitric oxide synthase (eNOS) was detected by Western blotting. SPSS 28.0 was used for statistical analysis, and measurement data were presented as Mean±SD. Independent sample t-test was used to compare data across two groups. P<0.05 was considered statistically significant. Results:(1) At 6 hours and 1, 3, 5, 7 days after surgery, the experimental group displayed higher blood perfusion than the control group at the bilateral iliolumbar and the left posterior intercostal vascular territories (all P<0.01). (2) On the 7th day after surgery, the artery dilation of the experimental group was more obvious than that of the control group; the percentage of the survived flap area in the experimental group was higher than that in the control group [(87.6±3.2)% vs. (65.3±3.0)%, P<0.01]; the intraluminal diameter of the choke artery was greater in the experimental group than that in the control group[(49.3±3.1) μm vs. (35.1±2.3) μm, P<0.01]; and the relative expression of eNOS in the experimental group was higher than that in the control group (0.87±0.07 vs. 0.50±0.05, P<0.01). Conclusion:The distal vein (right posterior intercostal vein) of dorsal four-territory perforator flap of SD rats directly guided the pedicle artery blood supply to promote the expression of eNOS, dilated the arteries in each zone of the flap, increased the blood supply to the distal artery of the flap, and ultimately enhanced the flap survival area.

Objective:To investigate the developmental behavior of early term infants at 6 months and its difference from that of complete full-term infants.Methods:A healthy maternal and infant birth cohort in maanshan city, established in Maanshan Maternal and Child Health Hospital from June 2015 to June 2016. Birth outcomes were copied from the hospital electronic medical record system after delivery. The Chinese Ages and Stages Questionnaires was used to assess developmental behavior. The chi-square test and multivariate unconditional logistic regression model were used to analyze the differences in the behavioral development of early and full term infants.Results:The birth rate of early term infants was 24.74% (500/2 021). The detection rates of communication, gross motor, fine motor, problem solving and individual-social areas in early term infants were 2.1%, 3.2%, 6.1%, 6.3% and 2.7%, respectively. The detection rate of problem-solving area in early term infants was significantly higher than that in the full-term infants (6.3% vs. 3.7%, χ 2=5.42, P<0.05). After controlling for confounding factors, compared with full-term infants, the risk of problem-solving area in early infants was significantly increased ( OR=1.65, 95%CI:1.01-2.70, P<0.05). Conclusion:The risk of behavioral retardation in Early term infants is significantly higher than that in full-term infants, and long-term follow-up and appropriate early development promotion interventions are needed to improve their quality of life.

Objective:To examine the relationship between pre-pregnancy BMI, gestational diabetes (GDM) and different indicators of childhood obesity at the age of 4.Methods:Based on Ma’anshan Birth Cohort Study, singleton children who were born in Ma’anshan of Anhui province from October 2013 to April 2015, were followed for 4 years, consecutively. During the first questionnaire survey, data including pre-pregnancy weight, height and socio-demography were collected. During 24-28 week of gestation, 75 g oral glucose tolerance test was conducted for them. Childhood height, weight, waist circumference and body composition were measured at the age of 4. Comparisons between groups were performed using chi-square test, analysis of variance or t-test. The relationship between pre-pregnancy overweight/obesity, GDM and childhood obesity-related characteristics were analyzed by logistic regression model and generalized linear model analysis. Results:The prevalence rates of overweight and obesity in children at the age of 4 were 13.08% and 6.03%, respectively. After adjustment for characteristics related to mothers and their children, significantly increased risk of obesity ( OR=3.27, 95% CI: 2.15-4.98), larger waist circumference ( OR=2.32, 95% CI: 1.72-3.14) and higher waist-to-weight ratio ( OR=2.29, 95% CI: 1.73-3.02) were seen in the offspring of women with pre-pregnancy overweight/obesity. Body composition (skeletal muscle, body fat, body fat percentage) of the offspring were strongly correlated with pre-pregnancy overweight/obesity of the mothers ( P<0.05). Maternal GDM was associated with higher risk of childhood obesity ( OR=1.78, 95% CI: 1.14-2.79), on mothers without GDM during pregnancy. However, neither larger waist circumference, or higher waist-to-weight ratio seemed to increase the risk. Moreover, maternal GDM was not associated with body composition measures (skeletal muscle, body fat, body fat percentage). Conclusion:Pre-pregnancy BMI and maternal GDM were independent risk factors for obesity in 4-year-old children, and pre-pregnancy BMI was correlated with various indicators of body composition in children.