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 detection success rates (DSRs) of different kinds of near-infrared spectrum non-invasive hemoglobin monitors in high-altitude environments.Methods:One hundred and forty-four healthy volunteers of either sex, aged 18-50 yr, were assigned to one of 3 groups using a random number table method: simulated high-altitude 3 500 meter group ( n=35), 4 000 meter group ( n=55) and 4 500 meter group ( n=54). Hemoglobin was detected by Radical-7, NW-9002SHM, A5 and TensorTip MTX type hemoglobin monitors in plain environment and simulated environment at different altitudes, and the DSRs were compared.Logistic regression analysis was conducted to identify the risk factors affecting the success rate of instrument detection, and the cut-off value was determined by ROC curve and the Youden index. Results:In the simulated high-altitude environment of 3500, 4000 and 4500 m, the DSR of TensorTip MTX was significantly higher than that of Radical-7, NW-9002SHM and A5 ( P<0.001), and there was no significant difference in the DSR among Radical-7, NW-9002SHM and A5 ( P>0.05). Low SpO 2 was the main factor affecting the DSRs of the Radical-7, NW-9002SHM and A5 type hemoglobin monitor in high-altitude environment ( P<0.001), and the cut-off value of SpO 2 in determining the success of detection was 88.5%, 87.5% and 89.5%, respectively.The DSR of TensorTip MTX was not affected by low SpO 2. Conclusions:The DSR of TensorTip MTX hemoglobin monitor is minimally affected by the high-altitude environment and can be preferred in the absence of oxygen supply; when Radical-7, NW-9002SHM or A5 hemoglobin monitor applied in high-altitude environments, oxygen saturation needs to be increased to ensure a high DSR.

Objective: To determine the contribution of follow-up formula (FUF) to the nutrient intake of 7-24-month-old infants and young children. Methods: The cluster random sampling method and the convenience sampling method were used in combination, and geographic and economic factors were taken into consideration. Four areas of China (Beijing, Hebei, Guangxi, Guangdong) were selected, with 120 infants chosen from each of these areas (half of which were 7-12 months old, and half were 13-24 months old). A dietary survey was completed by a continuous 24-hour weighing method over two days. Questionnaires were completed by their caregivers which included weighing the FUF and supplementary food given to the infant, and recording the frequency of breast feeding and any supplementary nutrients. A total of 518 questionnaires were distributed, and 472 questionnaires qualified for inclusion. Nutrient intake was calculated using the China food composition, infant formula food nutrient content and infant nutrition supplement brand-label information databases, and then the nutrient intake proportion (the percentage of estimated energy requirement (EER%), recommended nutrient intake (RNI%) or adequate intake (AI%)), and the contribution rate of FUF were analyzed. Results: A total of 472 infants were investigated (227 infants aged 7-12 months old, 245 infants aged 13-24 months old). The findings revealed that the median energy intake of 7- 12-month-old and 13- 24-month-old infants were 2 530.08 kJ and 3 445.48 kJ, respectively, which accounted for 85.18% and 94.14% of EER, respectively; and the median intake of protein reached 91.50% and 105.88% of their RNI/AI, respectively. For micronutrients, the median intake of vitamin B₁, vitamin B₂, niacin, vitamin E, potassium, zinc and manganese in 7- 12-month-old infants and vitamin B₂, vitamin E, potassium, magnesium, iron and manganese in 13-24-month-old children accounted for 82.00% and 114.29% of RNI/AI (RNI%/AI%), respectively. The intake of vitamin B₆, iron and selenium in 7-12-month-old infants and vitamin B₁, vitamin B₆, vitamin C, calcium and selenium in 13-24-month-old children was less than 80% RNI/AI. Furthermore, some nutrients showed higher intake levels, such as vitamin A, calcium, phosphorus and magnesium in 7-12-month-old infants and vitamin A and phosphorus in 13-24-month-old children, which were higher than 130% RNI/AI. In total, 40.53% (92) of infants aged 7-12 months and 52.65% (129) of children aged 13- 24 months were fed FUF as part of their diet, and its contribution rate to macronutrients was 29.69% for carbohydrates and 51.77% for fats, and to micronutrients was 2.04% for manganese and 74.24% for vitamin C. Conclusion FUF contributes to the nutrient intake of infants and young children aged from 7-24 months old at different rates depending on the macronutrient or micronutrient analyzed.