Objective:To observe the dynamic change of cystathionine β-synthase during cerebral ischemia-reperfusion and its effect in rats.Methods:The ischemic model was established with line embolism to block the middle cerebral artery .The reverse tran-scription-polymerase chain reaction ( RT-PCR) and Western blot assay were used to assess the expression of cystathionine β-synthase (CBS) in SHAM group,I group,and IR group.ELISA assay was performed to detected the homocysteine (HCY) level in plasma.After treating with the inhibitor of cystathionine β-synthase called hydroxyla mine(HA),the expression of hemeoxygenase 1(HO-1) and the pathologic change of the brain was evaluated .Results:As compared to sham group ,the expression of CBS was significantly up-regulated in ischemia-reperfusion group at 12 h post-reperfusion.Meanwhile,it existed the lowest level of HCY at 12 h post-reperfusion,comparing to sham grouzp ( 5.73 ±1.17 vs 2.88 ±0.93 , F=25.56 , P=0.001 ) .When inhibited the activity of CBS via using HA , the down-regulation of HO-1 protein and further damage in neuron were observed .Conclusion:Cystathionine β-synthase serves as an protective factor during cerebral ischemia-reperfusion.

Objective:To study the changes and clinical significance of Th1/Th2 cytokines in peripheral blood of children with mycoplasma pneumoniae pneumonia(MPP).Methods:The clinical data of 60 MPP children who were treated in the hospital from January 2016 to February 2020 were retrospectively analyzed.According to disease progression, MPP children were divided into acute period group( n=29) and recovery period group( n=31). Another 50 healthy children who underwent physical examination in the hospital during the same period were enrolled as healthy control group.The levels of interleukin 4(IL-4) and γ-interferon(IFN-γ) were detected by double sandwich antibody ELISA. Results:The levels of IFN-γ and IL-4 in the acute period group[(1 235.24±254.64)ng/L, (781.13±113.09)ng/L] were significantly higher than those in the recovery period group[(545.38±58.57)ng/L, (331.27±64.18)ng/L]( t=14.683, 19.108, P<0.001, <0.001) and the control group[(477.96±46.61)ng/L, (241.86±39.07)ng/L]( t=20.534, 30.813, P<0.001, <0.001), while Th1/Th2 level(1.65±0.37) in the acute period group was significantly lower than that in the recovery period group(1.97±0.42)( t=3.123, P=0.003) and the control group(2.28±0.56)( t=5.405, P<0.001). The levels of IFN-γ and IL-4 in the recovery period group were higher than those in the control group( t=5.729, 7.805, P=0.003, <0.001), while Th1/Th2 level in the recovery period group was lower than that in the control group( t=2.652, P=0.010). Conclusion:There are immune disorders of Th2 advantages in MPP children.

Objective To investigate the role of heme oxygenase-1 ( HO-1 ) and carbon monoxide ( CO) in children with mycoplasma pneumoniae infection. Methods A total of 198 cases with mycoplasma pneumoniae infection under 3 years were enrolled in this study. According to whether with wheezing,all cases were divided into wheezing group( n=58 ) and no wheezing group ( n=140 ) . According to having hypox-emia,wheezing group was divided into mild wheezing group(n=34) and severe wheezing group(n=24). And no wheezing group was set as control group. The serum COHb levels were measured by dual-wavelength spectrophotometry. The serum HO-1 were measured by ELISA. Results The levels of serum HO-1 and COHb% in severe wheezing group were ( 2 734. 10 ± 707. 59 ) ng/L, ( 3. 88 ± 0. 83 )%, and ( 1 130. 03 ± 671. 02) ng/L,(1. 16 ± 0. 63)% in mild wheezing group,and(931. 32 ± 451. 67) ng/L,(1. 04 ± 0. 37)% in no wheezing group,respectively. There were significant differences in serum HO-1 and COHb% between se-vere wheezing group and mild wheezing group(P<0. 01,respectively),and there were no significan differ-ences in serum HO-1 and COHb% between mild wheezing group and no wheezing group( P>0. 05,respec-tively). There was significant positive correlation between serum HO-1 and COHb%(r=0. 875,P<0. 01). Conclusion With mycoplasma pneumoniae infection,the expression of HO-1 and COHb% increase by the wheezing disease progression. HO-1 and CO may participate in the development process of infantile wheezing diseases.

Objective To investigate the hygienic status of large bottles of medical ultrasonic coupling gel in medical institution.Methods From February 2012 to April 2016, microbial contamination of large bottles of medical ultrasonic coupling gel in a women and children''s hospital was investigated and analyzed through on-the-spot random sampling and detection method.Results A total of 170 large bottles of medical ultrasonic coupling gel specimens were collected, 25 specimens were qualified, the qualified rate was 14.71％.Specimens were mainly from inpatient wards(58.24％) and operating departments(21.76％);there was no statistical difference in the qualified rate of specimens in each department(P>0.05).Contamination rates of coupling gel before and after the opening were both>80％, difference was not significant(P>0.05).A total of 145 strains of pathogenic bacteria were isolated, 18 of which were from unopened bottles, and 127 from opened bottles.Burkholderia cepacia was the main strain in both unopened and opened bottles, which accounting for 83.33％ and 54.33％ respectively,in addition, Pseudomonas aeruginosa and Serratia marcescens were also isolated from opened bottles, both were 15.75％, mixed contamination bacteria all included Serratia marcescens Conclusion The total bacteria counts in medical ultrasonic coupling gel in large bottles exceed the standard seriously, the manufacturer should strictly observe the quality control standards, medical institutions should adopt effective cleaning and disinfection measures.

Background: To date, consistent data have not been reported on the association between serum amyloid A (SAA) levels and type 2 diabetes mellitus (T2DM). The purpose of this study was to systematically summarize their relationship. Methods: Databases including PubMed, Cochrane Library, Embase, Web of Science, and MEDLINE were searched until August 2021. Cross-sectional and case-control studies were included. Results: Twenty-one studies with 1,780 cases and 2,070 controls were identified. SAA levels were significantly higher in T2DM patients than in healthy groups (standardized mean difference [SMD], 0.68; 95% confidence interval [CI], 0.39 to 0.98). A subgroup analysis showed that the mean age of participants and the continent that participants were from were related to differences in SAA levels between cases and controls. Furthermore, in T2DM patients, SAA levels were positively associated with body mass index (r=0.34; 95% CI, 0.03 to 0.66), triglycerides (r=0.12; 95% CI, 0.01 to 0.24), fasting plasma glucose (r=0.26; 95% CI, 0.07 to 0.45), hemoglobin A1c (r=0.24; 95% CI, 0.16 to 0.33), homeostasis model assessment for insulin resistance (r=0.22; 95% CI, 0.10 to 0.34), C-reactive protein (r=0.77; 95% CI, 0.62 to 0.91), and interleukin-6 (r=0.42; 95% CI, 0.31 to 0.54), but negatively linked with highdensity lipoprotein cholesterol (r=–0.23; 95% CI, –0.44 to –0.03). Conclusion The meta-analysis suggests that high SAA levels may be associated with the presence of T2DM, as well as lipid metabolism homeostasis and the inflammatory response.

Objective:To investigate the multilocus sequence typing feature of the virulence-associated genes of Staphylococcus aureus(S. aureus) separated from the clinical specimens of a multi-center cohort children in Guangzhou area. Methods:A total number of 412 Staphylococcus aureus strains isolated from 2 059 non-repeated fecal specimens of children by three groups′ researchers in Guangzhou Women and Children′s Medical Center from August 2018 to November 2018. While collecting specimens, patient clinical information is also properly collected and preserved. After extracting the DNA of the strain, the virulence-associated genes were detected by polymerase chain reaction (PCR), including the staphylococcal enterotoxin (SE) genes ( sea, seb, sec, sed, see) and the Panton-Valentine leucocidin-encoding gene ( pvl).The multi-locus sequence typing (MLST) method was performed to reveal the MLST feature of these genes and the statistical difference were examined by the the χ 2 test. Results:Among the 412 isolates of S. aureus, 256 strains (256/412, 62.1%) contains at least one SE gene. Among the enterotoxin gens, the sec (125/412, 30.3%), seb(98/412, 23.8%)and sea (66/412, 16.0%)genes were the three most prevalent members of SEs. The frequency of pvl gene in Staphylococcus aureus was 18.7%(77/412).Among them, the frequency of Staphylococcus aureus sea gene isolated from patients with gastroenteritis (58/319, 18.2%) was significantly higher than that from the non-gastroenteritis group (8/93, 8.6%)(χ2=4.912, P=0.027). The frequency of Staphylococcus aureus pvl gene isolated from the patients with pneumonia (8/21, 38.1%) was greater than that from the non-pneumonia group (6/47, 12.8%)(χ2=4.252, P=0.039). In addition, the virulence-associated gene of S. aureus was closely related to the specific ST type, 82.4% (28/34) of ST6 carried sea gene, all ST338 and ST59 carried seb gene, 96% (48/50) ST45 carried sec gene, and the pvl gene carrying rate of ST338 was 5/5. Conclusions:The SEA toxin produced by ST6 Staphylococcus aureus may be closely related to the diagnosis of gastroenteritis in children. The frequency of pvl virulence gene in Staphylococcus aureus in children with community-acquired pneumonia was higher than that in the non-pneumonia group, and closely related to the CC59.

Background Tricresyl phosphate (TCP) is mainly used as a flame retardant. Studies have confirmed that it has cytotoxicity and neurotoxicity, but its reproductive toxicity is not clear. Objective To investigate the reproductive toxicity and potential mechanism of TCP subacute exposure on Caenorhabditis elegans. Methods Caenorhabditis elegans were exposed to solvent control and 0.1, 1, 10, 100, and 1000 μg·L⁻¹ TCP respectively for 72 h. Brood size and number of fertilized eggs in the uterus were detected to evaluate reproductive ability. The number of total germline cells and the relative area of gonad arm were measured to evaluate the development of gonads. The body length and body width of Caenorhabditis elegans were detected to evaluate growth and development. The activities of reactive oxygen species (ROS) and superoxide dismutase (SOD) in Caenorhabditis elegans, and the mitochondrial active oxygen metabolism genes (mev-1 and gas-1) of N2 nematodes were detected by real-time fluorescence quantitative polymerase chain reaction (qRT-PCR) to evaluate oxidative stress. WS1433 transgenic nematodes and wild-type nematodes N2 were exposed to solvent control or TCP (0.1, 1, 10, 100, and 1000 μg·L⁻¹) respectively. DNA damage in germ cells of WS1433 transgenic nematodes was detected, the relative expressions of DNA damage-related genes (hus-1, clk-2, cep-1, and egl-1) in N2 nematodes were detected by qRT-PCR to evaluate the effect of TCP exposure on genetic damage. Results Compared with the solvent control group (217.00 ± 12.20), the brood size of N2 nematodes in the 100 μg·L⁻¹ and 1000 μg·L⁻¹ TCP groups decreased (170.80 ± 11.51, 169.60 ± 10.52, P < 0.05). Compared with the solvent control group (18.43 ± 1.69), the number of fertilized eggs of N2 nematodes in the 100 μg·L⁻¹ and 1000 μg·L⁻¹ TCP groups decreased (13.47 ± 0.81, 11.95 ± 0.90, P < 0.05). Compared with the solvent control group (312.46 ± 77.4), the number of total germline cells of N2 nematodes in the 100 μg·L⁻¹ and 1000 μg·L⁻¹ TCP groups decreased (281.80 ± 12.98, 273.50 ± 8.53, P < 0.05). Compared with the solvent control group, the relative area of gonads of N2 nematodes in the 100 μg·L⁻¹ and 1000 μg·L⁻¹ TCP groups decreased by 13.83% and 17.25% respectively (P<0.05). Compared with the solvent control group [(1058.10±80.12) μm, (78.21±14.69) μm], the body length and body width of N2 nematodes in the 100 μg·L⁻¹ and 1000 μg·L⁻¹ TCP groups decreased (P<0.05). Compared with the solvent control group, the relative fluorescence intensity of ROS in nematodes in the 10, 100, and 1000 μg·L⁻¹ TCP groups increased significantly (107.60%±1.02%, 105.90%±1.40%, and 106.40%±1.85%, respectively, P<0.05), and the activities of SOD were reduced (by 20.66%, 15.88%, and 16.44%, respectively, P<0.05). Compared with the solvent control group (1.3±1.3), the number of DNA-damaged germ cells of WS1433 nematodes in the 100 and 1000 μg·L⁻¹ TCP groups increased significantly (2.4±0.3, 2.7±0.3, P<0.05); the expressions of mev-1 and gas-1 genes in N2 nematodes in the 10, 100 and 1000 μg·L⁻¹ TCP groups decreased significantly (P<0.05); the expressions of hus-1 in the 0.1-1000 μg·L⁻¹ TCP groups significantly increased (P<0.05); the expressions of clk-2 and egl-1 in the 100 and 1000 μg·L⁻¹ TCP groups increased significantly (P<0.05); the expressions of cep-1 in the 1, 10, and 100 μg·L⁻¹ TCP groups increased significantly (P<0.05). Conclusion TCP may cause reproductive damage to nematodes through oxidative stress and germ cell DNA damage.