[Response of Organic Carbon Loss to Soil Erosion and Its Drivers: A Meta-analysis].

Soil erosion is the main driving force of soil organic carbon (SOC) loss and plays an important role in the global carbon cycle. It is helpful to understand the mechanism of SOC loss under soil erosion by evaluating the main driving factors of SOC loss under soil erosion and their influence degree. Therefore, based on 24 cases published in domestic and foreign journals from 2007 to 2021, this study investigated the effects of soil erosion on SOC loss in China under different climatic factors (climate types, rainfall, and rainfall intensity) and soil factors (soil types, bulk density, and aggregate size) by using Meta-analysis. The results showed that:① compared with that under no erosion disturbance, the SOC content under erosion decreased significantly (overall decreased 16.0%), showing obvious negative response characteristics. ② Under the erosion background, the negative response degree of SOC to different factors was as follows:rainfall intensity (65.0%)>mean annual rainfall (24.3%)>soil types (21.4%)>bulk density (20.2%)>aggregate size (16.5%)>climate types (9.1%). ③ Principal component analysis showed that climate was the dominant factor affecting SOC loss, and rainfall intensity was again shown to be the key factor. In this study, the characteristics and influencing factors of SOC loss under soil erosion in China were analyzed, which provided theoretical reference for the systematic understanding of the role of soil erosion in the carbon cycle.

Population pharmacokinetics-pharmacodynamics of ceftazidime in neonates and young infants: Dosing optimization for neonatal sepsis.

Ceftazidime is a third-generation cephalosporin with high activity against many pathogens. But the ambiguity and diversity of the dosing regimens in neonates and young infants impair access to effective treatment. Thus, we conducted a population pharmacokinetic study of ceftazidime in this vulnerable population and recommended a model-based dosage regimen to optimize sepsis therapy. Totally 146 neonates and young infants (gestational age (GA): 36-43.4 weeks, postnatal age (PNA): 1-81 days, current weight (CW): 900-4500 g) were enrolled based on inclusion and exclusion criteria. Ceftazidime bloods samples (203) were obtained using the opportunistic sampling strategy and determined by the high-performance liquid chromatography. The population pharmacokinetic-pharmacodynamic analysis was conducted by nonlinear mixed effects model (NONMEM). A one-compartment model with first-order elimination best described the pharmacokinetic data. Covariate analysis showed the significance of GA, PNA, and CW on developmental pharmacokinetics. Monte Carlo simulation was performed based on above covariates and minimum inhibitory concentration (MIC). In the newborns with PNA ≤ 3 days (MIC=8 mg/L), the dose regimen was 25 mg/kg twice daily (BID). For the newborns with PNA > 3 days (MIC=16 mg/L), the optimal dose was 30 mg/kg three times daily (TID) for those with GA ≤ 37 weeks and 40 mg/kg TID for those with GA > 37 weeks. Overall, on the basis of the developmental population pharmacokinetic-pharmacodynamic analysis covering the whole range of neonates and young infants, the evidence-based ceftazidime dosage regimens were proposed to optimize neonatal early-onset and late-onset sepsis therapy.

[Professor WU Xu's experience in treatment of tic disorders in children with acupuncture from "meridian tendons"].

Professor WU Xu believes that the pathogenesis of tic disorders in children is "agitation of liver wind, lending to excessive wind and spasm of tendons" "deficiency of yin fluid, the tendons failing to be nourished" "spirit failing to govern, leading to tendons not be restrained" and advocates to treat this disease from the theory of "meridian tendons". He suggests the acupoints that related to "meridian tendons", and emphasizes the depth of needling and the procedure of acupuncture, and believes that the core of treating is to balance the yin and yang of "meridian tendons" and regulate spirit.

[Effect of breastfeeding on the development of infection-related diseases during hospitalization in late preterm infants in 25 hospitals in Beijing, China].

OBJECTIVE: To investigate the incidence rate of infectious diseases during hospitalization in late preterm infants in Beijing, China, as well as the risk factors for infectious diseases and the effect of breastfeeding on the development of infectious diseases. METHODS: Related data were collected from the late preterm infants who were hospitalized in the neonatal wards of 25 hospitals in Beijing, China, from October 23, 2015 to October 30, 2017. According to the feeding pattern, they were divided into a breastfeeding group and a formula feeding group. The two groups were compared in terms of general status and incidence rate of infectious diseases. A multivariate logistic regression analysis was used to investigate the risk factors for infectious diseases. RESULTS: A total of 1 576 late preterm infants were enrolled, with 153 infants in the breastfeeding group and 1 423 in the formula feeding group. Of all infants, 484 (30.71%) experienced infectious diseases. The breastfeeding group had a significantly lower incidence rate of infectious diseases than the formula feeding group (22.88% vs 31.55%, P=0.033). The multivariate logistic regression analysis showed that breastfeeding was an independent protective factor against infectious diseases (OR=0.534, P=0.004), while male sex, premature rupture of membranes, gestational diabetes mellitus, and asphyxia were risk factors for infectious diseases (OR=1.328, 5.386, 1.535, and 2.353 respectively, P < 0.05). CONCLUSIONS: Breastfeeding can significantly reduce the incidence of infectious diseases and is a protective factor against infectious diseases in late preterm infants. Breastfeeding should therefore be actively promoted for late preterm infants during hospitalization.

Population pharmacokinetics and dosing optimization of latamoxef in neonates and young infants.

OBJECTIVES: There has been recent renewed interest in historical antibiotics because of the increased antibiotic-resistant bacterial strains. Latamoxef, a semi-synthetic oxacephem antibiotic developed in 1980s, has recently been brought back into use for treatment of infections in newborns; however, it is still used off-label in neonatal clinical practice due to the lack of an evidence-based dosing regimen. This study was performed to evaluate the pharmacokinetics of latamoxef in neonates and young infants, and to provide an evidence-based dosing regimen for newborns based on developmental pharmacokinetics-pharmacodynamics (PK-PD). METHODS: Opportunistic blood samples from newborns treated with latamoxef were collected to determine the latamoxef concentration by high-performance liquid chromatography with UV detection. Population PK-PD analysis was conducted using NONMEM and R software. A total of 165 plasma samples from 128 newborns (postmenstrual age range 28.4-46.1 weeks) were available for analysis. RESULTS: A two-compartment model with first-order elimination showed the best fit with the data. Current body weight, birth weight, and postnatal age were identified as significant covariates influencing latamoxef clearance. Simulation indicated that the current dosing regimen (30 mg/kg q12h) is adequate with an MIC of 1 mg/L. For an MIC of 4 mg/L, 30 mg/kg q8h was required to achieve a target rate of 70% of patients having a free antimicrobial drug concentration exceeding the MIC during 70% of the dosing interval. CONCLUSIONS: Based on the developmental PK-PD analysis of latamoxef, a rational dosing regimen of 30 mg/kg q12h or q8h was required in newborns, depending on the pathogen.

Population Pharmacokinetics and Dosing Optimization of Amoxicillin in Neonates and Young Infants.

Amoxicillin is widely used to treat bacterial infections in neonates. However, considerable intercenter variability in dosage regimens of antibiotics exists in clinical practice. The pharmacokinetics of amoxicillin has been described in only a few preterm neonates. Thus, we aimed to evaluate the population pharmacokinetics of amoxicillin through a large sample size covering the entire age range of neonates and young infants and to establish evidence-based dosage regimens based on developmental pharmacokinetics-pharmacodynamics. This is a prospective, multicenter, pharmacokinetic study using an opportunistic sampling design. Amoxicillin plasma concentrations were determined using high-performance liquid chromatography. Population pharmacokinetic analysis was performed using NONMEM. A total of 224 pharmacokinetic samples from 187 newborns (postmenstrual age range, 28.4 to 46.3 weeks) were available for analysis. A two-compartment model with first-order elimination was used to describe population pharmacokinetics. Covariate analysis showed that current weight, postnatal age, and gestational age were significant covariates. The final model was further validated for predictive performance in an independent cohort of patients. Monte Carlo simulation demonstrated that for early-onset sepsis, the currently used dosage regimen (25 mg/kg twice daily [BID]) resulted in 99.0% of premature neonates and 87.3% of term neonates achieving the pharmacodynamic target (percent time above MIC), using a MIC breakpoint of 1 mg/liter. For late-onset sepsis, 86.1% of premature neonates treated with 25 mg/kg three times a day (TID) and 79.0% of term neonates receiving 25 mg/kg four times a day (QID) reached the pharmacodynamic target, using a MIC breakpoint of 2 mg/liter. The population pharmacokinetics of amoxicillin was assessed in neonates and young infants. A dosage regimen was established based on developmental pharmacokinetics-pharmacodynamics.

[Effects of hydrocortisone on circulating and intramyocardial inflammatory mediators in severe septic rats with myocardial injury induced by Escherichia coli].

OBJECTIVE: Severe sepsis and septic shock remain the most common cause of death in intensive care units. The main causes of death in sepsis are the cardiac dysfunction and hypotension resistant to cateolamines. The prevalence of relative adrenal insufficiency in severe sepsis and septic shock was estimated at about 32%-51%. Several meta-analysis demonstrated that high-dose glucocorticoids decreased survival during sepsis, while stress doses of corticosteroids may benefit these patients. The exact reason for such widely divergent outcome produced by different doses of corticosteroid is still not understood. Therefore, the study was undertaken to observe the effects of different doses of hydrocortisone (HC) on circulating and intramyocardial inflammatory mediators in severe septic rats with myocardial injury induced by Escherichia coli (E. coli). METHODS: The model was established by two injections of inactivated E. coli Forty male Wistar rats were randomly divided into five groups: high-dose of HC group (150 mg/kg), medium-dose group (20 mg/kg), low-dose group (6 mg/kg), model group (NS substituted for HC), and control group (NS for E. coli and HC). Each group had eight rats. After 2 hours of treatment, specimens were collected to measure serum cardiac troponin I (cTnI), tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), nitric oxide (NO) and total NO synthase (NOS). NO and total NOS in myocardial homogenate were also detected. The expression of inducible NOS (iNOS) of myocytes was investigated. RESULTS: All the above-mentioned markers in model group significantly higher than those in control group. After HC injection, serum cTnI concentrations in low-dose group decreased to normal values compared to that of model group, while in another two HC groups, the concentrations were higher than those in model group. TNF-alpha level was not significantly influenced. But IL-1beta level declined to normal values, being prominent in low-dose HC group. Neither high-dose nor middle-dose HC could lower serum NO or total NOS, but low-dose HC could greatly inhibit both NO and NOS levels (P < 0.05). There was no significant difference in the level of NO and total NOS of myocardial homogenate between left and right ventricles. There was no iNOS expression by normal myocardium, while the expression in model group was significantly increased. After HC injection, the iNOS expressions by myocardium in three HC groups were weaker than those in model group. The intensity of iNOS signals became weak with the decrease in HC dose. CONCLUSION: Different doses of HC might exert different effects on circulating and intramyocardial inflammatory mediators in severely septic rats with myocardial injury induced by E. coli. Low-dose HC could significantly inhibit such mediators as well as iNOS expression by cardiomyocytes. The results suggest that low dose HC exert protective effect on myocardial injury of severely septic rats.

[Effects of different doses of hydrocortisone on acute lung injury in rats with early septic shock induced by Escherichia coli].

OBJECTIVE: To observe the effects of different doses of hydrocortisone (HC) on acute lung injury (ALI) and inflammatory response in rats at early stage of septic shock induced by Escherichia coli and to investigate the possible mechanisms for such differences. METHODS: ALI model of early septic shock was induced in rats by two injections of Escherichia coli at 5 hours interval, with the first intraperitoneal injection of 6.50 x 10(10) cfu/kg and followed by an external jugular vein injection of 2.00 x 10(11) cfu/kg. Forty Wistar rats were randomly divided into the following five groups: normal control, ALI without HC treatment, high-dose HC (150 mg/kg), medium-dose HC (20 mg/kg) and low-dose HC (6 mg/kg). Two hours after the treatment, the specimens were collected for histopathological examination and the biological indexes of lung injury were measured. The expressions of intercellular adhesion molecule-1 (ICAM-1) and glucocorticoid receptor (GR) in lung tissues were also investigated by immunohistochemical assays. RESULTS: The biological indexes of lung injury [wet/dry weight ratio (g/g), total protein concentration in bronchoalveolar lavage fluid (mg/L) and lung permeability index (10(-3))] in ALI group (4.76 +/- 0.10, 278.96 +/- 60.45, 4.73 +/- 0.60) were significantly increased as compared to those in normal control group (4.10 +/- 0.07, 67.46 +/- 13.27, 1.12 +/- 0.15) (P < 0.05). The grades of ALI pathologic changes in ALI group (11.13 +/- 1.13) was significantly higher than that in the normal control group (0.50 +/- 0.53, P < 0.05). The ratio of expression area of ICAM-1 in ALI group (0.149 +/- 0.037) was significantly increased as compared to that in the normal control group (0.051 +/- 0.018) (P < 0.05). The ratio of expression area of GR all group (0.043 +/- 0.037) was significantly decreased as compared to that in the normal Control group (0.124 +/- 9.040) (P < 0.05) After administration of HC, all the lung injury indexes, pathological grades and the ratios of expression area of ICAM-1 and GR were significantly improved, with the most remarkable effects observed in the low-dose HC group. The expressions of ICAM-1 and GR showed a significantly negative linear correlation (r = 0.55, P < 0.0001). CONCLUSION: These results indicated that the low-dose HC treatment had the most remarkable effects of improving the biological indexes of lung injury, inflammatory mediators and pathological changes. These HC dose dependent therapeutic effects might be associated with the level of GR expression.