Objective To observe the effect of mild hypothermia on myocardial β-adrenergic receptor (β-AR) signal pathway after cardiopulmonary resuscitation (CPR) in pigs with cardiac arrest (CA) and explore the mechanism of myocardial protection. Methods Healthy male Landraces were collected for reproducing the CA-CPR model (after 8-minute untreated ventricular fibrillation, CPR was implemented). The animals were divided into two groups according to random number table (n = 8). In the mild hypothermia group, the blood temperature of the animals was induced to 33 ℃ and maintained for 6 hours within 20 minutes after return of spontaneous circulation (ROSC) by using a hypothermia therapeutic apparatus. In the control group, the body temperature of the animals was maintained at (38.0±0.5)℃ with cold and warm blankets. The heart rate (HR), mean arterial pressure (MAP), the maximum rate of increase or decrease in left rentricular pressure (+dp/dt max)were measured during the course of the experiment. The cardiac output (CO) was measured by heat dilution methods before CA (baseline), and 0.5, 1, 3, 6 hours after ROSC respectively, the venous blood was collected to detect the concentration of cTnI. Left ventricular ejection fraction (LVEF) was measured with cardiac ultrasound before CA and 6 hours after ROSC. Animals were sacrificed at 6 hours after ROSC and the myocardial tissue was harvested quickly, the mRNA expression of β1-AR in myocardium was detected by reverse transcription-polymerase chain reaction (RT-PCR), the contents of adenylate cyclase (AC) and cyclic adenosine monophosphate (cAMP) were detected by enzyme linked immunosorbent assay (ELISA), the protein content of G protein-coupled receptor kinase 2 (GRK2) was detected by Western Blot. Results After successful resuscitation, the HR of both groups were significantly higher than the baseline values, CO, ±dp/dt max were significantly decreased, MAP were not significantly changed, serum cTnI levels were significantly increased. Compared with the control group, HR at 0.5, 1, 3 hours after ROSC were significantly decreased in mild hypothermia group (bpm: 142.80±12.83 vs. 176.88±15.14, 115.80±11.48 vs. 147.88±18.53, 112.60±7.40 vs. 138.50±12.02, all 1 < 0.01), CO was significantly increased at 1 hours and 3 hours after ROSC (L/min: 3.97±0.40 vs. 3.02±0.32, 4.00±0.11 vs. 3.11±0.59, both 1 < 0.01), +dp/dt max at 3 hours and 6 hours was also significantly increased after ROSC [+dp/dt max (mmHg/s): 3 402.5±612.7 vs. 2 130.0±450.6, 3 857.5±510.4 vs. 2 562.5±633.9; -dp/dt max (mmHg/s): 2 935.0±753.2 vs. 1 732.5±513.6, 3 520.0±563.6 vs. 2 510.0±554.3, all 1 < 0.05], the cTnI was significantly decreased at 3 hours and 6 hours afher ROSC (μg/L: 1.39±0.40 vs. 3.24±0.78, 1.46±0.35 vs. 3.78±0.93, both 1 < 0.01). The left at 6 hours after ROSC in both groups was decreased as compared with that before CA. The LVEF in the mild hypothermia group was higher than that in the control group (0.52±0.04 vs. 0.40±0.05, 1 < 0.05). The mRNA expression of β1-AR, and concentrations of AC and cAMP in hypothermia group were significantly higher than those in control group [β1-AR mRNA (2-ΔΔCT): 1.18±0.39 vs. 0.55±0.17, AC (ng/L):197.0±10.5 vs. 162.0±6.3, cAMP (nmol/L): 1 310.58±48.82 vs. 891.25±64.95, all 1 < 0.05], GRK2 was lower than that in the control group (GRK2/GAPDH: 0.45±0.05 vs. 0.80±0.08, 1 < 0.05). Conclusion Mild hypothermia can reduce the degree of cardiac function injury after CPR, and its mechanism may be related to the reduction of impaired myocardial β-AR signaling after CPR.

Nuclear magnetic resonance spectroscopy is one of the main analytical techniques for detecting metabolomics, which has the advantages of simple operation, rapid detection and non-invasive feature. By monitoring the changes of metabolites in the body, it is helpful to deeply understand the mechanism of disease and play a role in the diagnosis and treatment of diseases, but its clinical application has not yet been popularized. In recent years, the application of metabolomics in tumors has increasingly become a research hotspot. Therefore, in order to provide a reference for the research and clinical application of tumor metabolomics, the nuclear magnetic resonance spectroscopy and tumor metabolomics were introduced in this paper, and the application progress of metabolomics analysis based on this technique in early tumor screening, clinical diagnosis and prognosis evaluation were reviewed in this paper.

Objective To investigate the relationship between cystatin C level and the plasma trough concentration of teicoplanin, so as to provide a reference for the rational application of teicoplanin in clinical practice. Methods The clinical data of the patients receiving teicoplanin, who admitted to our hospital from October 2017 to July 2020 were retrospectively analyzed. The distribution of teicoplanin concentration, the difference of teicoplanin concentration under different cystatin C level, and influence factors for teicoplanin concentration (<15 µg/ml) were analyzed. Results A total of 98 patients including 65 males and 33 females, aged 19 to 94 (52.2±16.2) years old, with 141 trough concentrations were enrolled. The trough concentration of teicoplanin was 11.51 (8.35, 19.07) µg/ml, and the range was 3.57-41.93 µg/ml. 95 cases (67.38%) had teicoplanin concentration <15 µg/ml. When the concentration of cystatin C was >1.05 mg/L, the trough concentration of teicoplanin were 11.37 (8.96, 20.52) µg/ml, significantly higher than those when the concentration of cystatin C was in normal [8.68 (6.34, 11.79) µg/ml, Z=−2.636, P<0.05]. Logistic regression analysis showed that cystatin C level was the influencing factor for teicoplanin trough concentration does not meet the standard (OR=1.529, 95%CI=1.001-2.336, P<0.05). Conclusion The concentration of teicoplanin is significantly increased when the cystatin C level is higher than the normal. Cystatin C level is the influence factor for teicoplanin trough concentration not meeting the standard. The cystatin C level may be considered as a reference for teicoplanin dosage adjustment in clinical practice.