Analysis of SARS-CoV-2 Infection Among Inpatients in a Tertiary Hospital in Guangzhou During the Covid-19 Pandemic / 中山大学学报(医学科学版)

ObjectiveAt the end of November 2022， Guangzhou implemented the latest Covid-19 epidemic prevention policy and began to gradually lift the lockdown. However， under the new epidemic prevention situation， the situation of SARS-CoV-2 infection in hospitalized patients in China is still unclear. Accordingly， this paper aims to study the SARS-CoV-2 infection of hospitalized patients in Guangzhou under the new epidemic prevention and control situation. MethodsThe results of SARS-CoV-2 nucleic acid tests in our hospital from the end of November 2022 to the beginning of February 2023 were retrospectively analyzed. The positive rate of SARS-CoV-2 nucleic acid tests in outpatients and inpatients under the new epidemic prevention situation， and the nosocomial infection of SARS-CoV-2 in inpatients were statistically analyzed. ResultsThis study retrospectively analyzed the SARS-CoV-2 nucleic acid test results of 13 959 patients， including 6 966 outpatients and 6 993 inpatients. On November 30， 2022， the SARS-CoV-2 nucleic acid test results of outpatients began to be positive， indicating that the outbreak of the SARS-CoV-2 infection had begun. On December 7， one case of SARS-CoV-2 nucleic acid test results of hospitalized patients was positive， and nosocomial infections began to break out. On December 15， the positive rate of SARS-CoV-2 nucleic acid test among patients exceeded 40 %， and the epidemic entered its peak period. After the end of December， the test positive rate gradually decreased， but the positive rate of inpatients was always higher than that of outpatients. Compared with December 2022， the positive rate of SARS-CoV-2 nucleic acid test of patients in many departments in January 2023 decreased， but the positive rate of SARS-CoV-2 nucleic acid test of inpatients in the oncology department increased significantly （P < 0.001）. Further analysis found that the nosocomial infection rate of SARS-CoV-2 in inpatients was 86.57 % （329/380）. However， the nosocomial infection rate in lymphoma patients ［58.33 % （14/24）］ was significantly lower than that of the hospitalized patients with other disease types （P < 0.001）. ConclusionThe positive rate of SARS-CoV-2 nucleic acid testing among patients reached its peak in mid-December 2022. In January 2023， the positive rate of SARS-CoV-2 nucleic acid testing gradually decreased， while the number or positive rate of SARS-CoV-2 nucleic acid testing positive patients in some departments increased. The nosocomial infection rate among hospitalized patients is as high as 90 %. There are differences in the nosocomial infection rate of SARS-CoV-2 among inpatients with different disease types. In summary， this study provides preliminary data on the epidemiological characteristics of SARS-CoV-2 infection among hospitalized patients in Guangzhou， as well as the protection against infection among hospitalized patients and cross-infection between medical staffs and patients.

Regulatory Mechanism of Youguiwan on Articular Cartilage Degeneration via IL-6/STAT3 Signaling Pathway in Rats with Knee Osteoarthritis / 中国实验方剂学杂志

<b>Objective::To observe the effect of Youguiwan on the levels of cartilage transducers and activators of transcription 3 (STAT3) and interleukin-6 (IL-6) in rats with knee osteoarthritis (KOA). <b>Method::Sixty SD rats were randomly divided into six groups: sham control group, model group, glucosamine sulfate group and Youguiwan (high, middle and low-dose) groups. The modified Hulth method was used to prepare KOA models for 6 weeks. The shame control group and the model group were treated with normal saline, Youguiwan high, middle, low-dose groups received Youguiwan 4.8, 2.4, 1.2 g·kg^-1 by gavage respectively, and the glucosamine sulfate group was treated with glucosamine sulfate 0.17 g·kg^-1. The rats were administrated for 8 weeks according to the dose. After intervention, each group was put to death by femoral artery blood collection, and the keen cartilages of the rats were collected. The pathological changes were observed by htoxylin eosin (HE) staining method, and Mankin score was evaluated. The expressions of STAT3, superoxide dismutase3(SOD3) and Wnt inhibitory factor 1(WIF1) in articular cartilage were detected by immunohistochemistry. The expressions of IL-6 mRNA in articular cartilage were detected by quantitative real-time fluorescence polymerase chain reaction (Real-time PCR). The expression of WIF1 in articular cartilage was detected by Western blot. <b>Result::Compared with the sham control group, the Makin score was obviously increased in the model group, the protein expression of STAT3 was increased significantly, the mRNA of IL-6 was raised significantly, but the protein expression of WIF1 was decreased significantly (<italic>P</italic><0.01), articular cartilage was seriously damaged, and chondrocytes were arranged in disorder. Compared with the model group, the Makin score was declined obviously in the high-dose Youguiwan group, the protein expression of STAT3 was significantly reduced, the mRNA expression of IL-6 was significantly reduced in Youguiwan treatment group, while the protein expression of WIF1 was significantly increased (<italic>P</italic><0.05, <italic>P</italic><0.01), the cartilage structure returned to be normal, the chondrocytes distribution was uneven, and articular cartilage surface was not smooth. <b>Conclusion::Youguiwan could significantly improve the articular cartilage degeneration of KOA rats, and inhibit the inflammation of chondrocytes, which may be related to the suppression of STAT3 and IL-6 expression.

Molecular epidemiology of Listeria monocytogenes isolated from ready-to-eat food in 2017 in China / 中华预防医学杂志

To analyze the molecular characteristics of strains from ready-to eat food in China. A total of 239 strains isolated from ready-to-eat food in 2017, all strains underwent whole-genome sequencing (WGS) , and comparisons uncovered population structure derived from lineages, clonal complex, serogroups, antimicrobial susceptibility and virulence, which were inferred in silico from the WGS data. Core genome multilocus sequence typing was used to subtype isolates. All strains were categorized into three different lineages, lineage Ⅱ was the predominant types in food, and IIa was the main serogroups. CC8, CC101 and CC87 were the first three prevalent CCs among 23 detected CCs, accounting for 49.4%. Only 4.6% (11 isolates) of tested strains harbored antibiotic resistance genes, which were mostly trimethoprim genes (7 isolates, 2.9%). All strains were positive for LIPI-1, and only a part of strains harbored LIPI-3 and LIPI-4, accounting for 13.8% (33 isolates) and 14.2% (34 isolates), respectively. ST619 carried both LIPI-3 and LIPI-4. 51.5% (123 isolates) of strains carried SSI-1, and all CC121 strains harbored SSI-2. Different lineages, serogroups and CCs can be separated obviously through cgMLST analysis, and 24 sublineages were highly concordant with CCs. Ⅱa was the main serogroups in ready-to-eat food isolates in China; CC8, CC101 and CC87 were the prevalent CCs, and CC87 isolates was hypervirulent isolates, cgMLST method can be adopted for prospective foodborne disease surveillance and outbreaks detection.

Analgesic and anti-inflammatory activities and mechanisms of 70% ethanol extract of Zygophyllum macropodum in animals / 中草药·英文版

Objective: To screen the preliminary phytochemical components, to investigate the acute oral toxicity, the analgesic and anti-inflammatory effects, and to analyze inflammatory factors on mice or rats of 70% ethanol extract of Zygopgyllum macropodum aerial parts (ZME). Methods: Preliminary phytochemical screening was carried out by color reaction. Acute oral toxicity was investigated by body weight, relative organ weight and other toxic signs. Acetic acid induced writhing and hot plate test were used to determine analgesic effect. Acetic acid induced vascular permeability and carrageenan induced paw edema were used to confirm anti-inflammation. Protein in pleural effusion, prostaglandin E2 (PGE2) and tumor necrosis factor alpha (TNF-α) in serum of pleuritic rats induced by carrageenan were analyzed to explore the action mechanisms. The test groups received ZME with 100, 300, 600 mg/kg, the positive control with aspirin (ASP) 200 mg/kg for mice, and ZME with 70, 210, 420 mg/kg and ASP 150 mg/kg for rats orally. The control (C) or negative control (NC) groups received 2% Tween 80 of 10 mL/kg orally. Results: ZME contain flavonoids, saponins, phenols and tannins, steroids, terpenoids, fats and oils, glycosides, carbohydrates, and reducing sugar, but no alkaloids. The lethal dose 50% (LD50) of ZME was greater than 2000 mg/kg and no toxic or deleterious effects and death during 14 d. Oral administration 300 and 600 mg/kg of ZME produced analgesic and anti-inflammatory effects significantly (P < 0.05 or P < 0.001) vs NC. It can reduce the writhing number, prolong the heat resisting time, suppress the permeability of the capillary wall increasing, mitigate the paw edema, reduce the content of protein in pleural effusion, and reduce PGE2 and TNF-α in blood. Conclusions: ZME possessed analgesic and anti-inflammatory activities which related to inhibit the production of protein, PGE2 and TNF-α. The LD50 of ZME treated orally to mice was greater than 2000 mg/kg.

The Survey of Cronobacter spp. (formerly Enterbacter sakazakii) in Infant and Follow-up Powdered Formula in China in 2012 / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To determine Cronobacter spp. contamination in infant and follow-up powdered formula in China.</p><p><b>METHODS</b>All of 2282 samples were collected from the retail markets in China from January 2012 to December 2012, and analyzed for Cronobacter spp. by the Chinese National Food Safety Standard. Characterization of the isolates was analyzed by pulsed-field gel electrophoresis (PFGE) with XbaI and SpeI restriction enzymes.</p><p><b>RESULTS</b>Cronobacter spp. strains were isolated from 25 samples, and the positive rates in infant powdered formulas and follow-up powdered formulas were 0.90% (10/1011) and 1.18% (15/1271), respectively. Analysis of variable data regarding different purchasing store formats, seasonality, and production locations as well as comparison of infant versus follow-up formulas did not reveal statistically significant factors. During the sampling period, one of six surveillance zones did exhibit a statistically significant trend towards higher positive rate. PFGE characterization of Cronobacter spp. to elucidate genetic diversity revealed only three pairs of Cronobacter spp. out of 25 having the same PFGE patterns.</p><p><b>CONCLUSION</b>The current investigation indicated a lower positive rate of Cronobacter spp. in the powdered formula in China. This evidence suggested contamination originating from multiple different sources during the manufacturing process.</p>

Effect of citric acid stimulation on salivary alpha-amylase, total protein, salivary flow rate and pH value in Pi deficiency children / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To compare the effect of citric acid stimulation on salivary alpha-amylase (sAA), total protein (TP), salivary flow rate, and pH value between Pi deficiency (PD) children and healthy children, thereby providing evidence for Pi controlling saliva theory.</p><p><b>METHODS</b>Twenty PD children were recruited, and 29 healthy children were also recruited at the same time. Saliva samples from all subjects were collected before and after citric acid stimulation. The sAA activity and amount, TP contents, salivary flow rate, and pH value were determined and compared.</p><p><b>RESULTS</b>(1) Citric acid stimulation was able to significantly increase salivary flow rate, pH value, sAA activities, sAA specific activity and sAA amount (including glycosylated and non-glycosylated sAA amount) in healthy children (P<0.05), while it could markedly increase salivary flow rate, pH value, and glycosylated sAA levels in PD children (P<0.05); (2) Although there was no statistical difference in determined salivary indices between the two groups (P>0.05), salivary indices except salivary flow rate and glycosylated sAA levels decreased more in PD children. There was statistical difference in sAA activity ratio, sAA specific activity ratio, and the ratio of glycosylated sAA levels between PD children and healthy children (P<0.05).</p><p><b>CONCLUSION</b>PD children had decreased response to citric acid stimulation.</p>

Correlation study on Chinese medical syndrome types of chronic hepatitis B patients and HLA-DR13 gene, BCP mutation, and T-lymphocyte subsets / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To explore the correlation between the HLA-DR13, basic core promoter (BCP), changes of T lymphocyte subset and clinical Chinese medical syndromes of chronic hepatitis B (CHB).</p><p><b>METHODS</b>Totally 102 CHB patients were syndrome typed as Gan depression Pi deficiency syndrome (GDPDS), Pi-Shen yang deficiency syndrome (PSYDS), Gan-gallbladder dampness heat syndrome (GGDHS), Gan-Shen yin deficiency syndrome (GSYDS), and static blood blocking collaterals syndrome (SBBCS). Besides, 30 healthy subjects were recruited as the normal control group. The blood HBV-DNA level and HLA-DR13 gene were detected with real time fluorescent PCR. The expression of CD4+ and CD8+ in T lymphocytes was detected using flow cytometry. The mutation of serum A1762T/G1764A was detected using PCR sequencing. Hepatitis Be antigen (HBeAg) was detected with ELISA, and correlation between various Chinese medical syndrome types and objective indicators were analyzed.</p><p><b>RESULTS</b>There was no statistical difference in HBV-DNA quantitative results among various syndrome types (P > 0.05). HBeAg positive rate was higher in GDPDS than in other syndrome types (P < 0.05). It was sequenced as GDPDS > GSYDS > SBBCS > GGDHS > PSYDS. Compared with the normal control group, percentages of CD3+ and CD3+ CD4+ were lower in PSYDS (P < 0.05). The ratio of CD3+ CD4+/CD3+ CD8 was lower in GGDHS and PSYDS than in the normal control group (P < 0.05). There was no statistical difference in the CD3+ CD8+ percentage among various syndrome types (P > 0.05). The quantitation of HLA-DR13 gene was lower in GDPDS and GSYDS than in the normal control group (P < 0.05). The positive rate of BCP mutation was higher in GSYDS than in other syndrome types (P < 0.05).</p><p><b>CONCLUSION</b>Co-detection results of HLA-DR13 and BCP could be used as reference indices of Chinese medical syndrome typing of CHB.</p>

Prevalence and antibiogram distribution of Salmonella isolated from broiler production and processing course in four provinces, China / 中华预防医学杂志

<p><b>OBJECTIVE</b>To determine the contamination condition of Salmonella in broiler breeding and slaughter processing in China and to investigate the distribution of antimicrobial resistance profiles.</p><p><b>METHODS</b>Five large-scale broiler holdings and fourteen slaughterhouses were chosen to detect Salmonella in Henan, Jiangsu, Sichuan and Shandong provinces in 2010. A total of 835 anal swabs and 744 chicken carcasses were sampled to compare the difference of Salmonella contamination rate.Salmonella isolates were identified by serotyping according to Kauffmann-White scheme.The antimicrobial susceptibilities of Salmonella isolates were determined by broth microdilution method and sixteen antimicrobial agents were chosen and examined.</p><p><b>RESULTS</b>In total, Salmonella isolates were recovered in 56 (6.7%) specimens among 835 collected anal swabs and 122 (16.4%) specimens among 744 broiler carcasses. Positive rate of Salmonella in broiler carcasses was higher than anal swabs (χ(2) = 36.94, P < 0.05). The dominant Salmonella serovars isolated from broiler anal swabs were S.enterica serovar Indiana and S.enterica serovar Enteritidis, accounting for 58.9% (33/56) and 32.1% (18/56) respectively. The prevalent serovars in broiler carcasses were also the two serovars and occupied 29.8% (37/124), 32.2% (40/124) respectively. Nearly 95.0% (171/180) Salmonella isolates were resistant to at least one antimicrobial, 78.3% (141/180) Salmonella strains were multi-drug resistant isolates and 20 (11.1%) Salmonella isolates were resistant to 14 antimicrobials.</p><p><b>CONCLUSION</b>Our findings indicated that Salmonella contamination was common and serious in commercial broiler production and processing course in China. Salmonella contamination rate in broiler slaughter processing performance was higher than broiler flocks. Additionally, antibiotic resistance of Salmonella was in serious situation.</p>

Expressions of BNP and NPR-A in rat models of chronic nonbacterial prostatitis and their significance / 中华男科学杂志

<p><b>OBJECTIVE</b>To investigate the expressions of brain natriuretic peptide (BNP) and natriuretic peptide receptor (NPR-A) in the cord dorsal horn ganglion (DRG) of rat models of chronic nonbacterial prostatitis (CNP) and the relation of BNP and NPR-A with CNP-induced chronic pain.</p><p><b>METHODS</b>We established CNP models in 30 healthy clean SD rats using Freund's complete adjuvant, and included another 10 in a sham-operation group. The prostate tissues were subjected to HE staining, and the expressions of BNP and NPR-A in the L5-S2 DRGs were detected by real-time PCR.</p><p><b>RESULTS</b>Higher degree of inflammation was related to longer modeling time. At 3, 7 and 10 days, the expressions of BNP in the CNP models were 2.16 +/- 0.35, 1.61 +/- 0.21 and 1.32 +/- 0.36, and those of NPR-A were 2.75 +/- 0.06, 2.15 +/- 0.15 and 1.04 +/- 0.13, respectively, significantly higher at 3 and 7 days as compared with the sham-operation group (P<0.05), but with no statistically significant difference at 10 days.</p><p><b>CONCLUSION</b>BNP and NPR-A are expressed in the L5-S2 DRGs of SD rats and their expressions can be upregulated by CNP. BNP and NPR-A may be involved in the mechanisms of CNP-induced pain.</p>

Involvement of MAPK pathways in NMDA-induced apoptosis of rat cortical neurons / 生理学报

NMDA-induced excitotoxicity cause severe neuronal damage including apoptosis and necrosis. The present study was aimed to evaluate the proportion of NMDA-induced apoptosis of rat cortical neurons and discover signal transduction mechanism. Caspase inhibitor and lactate dehydrogenase (LDH) assay were used to study the NMDA-induced apoptosis. To explore the involved signal pathways, the primary culture of rat cortical neurons were pretreated by the inhibitors of three MAPK pathways, extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38 MAPK. With 2 h of NMDA treatment, cellular apoptosis was measured by caspase-3 activity, terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling (TUNEL) and Annexin V staining. The results showed that: (1) Caspase-dependent apoptosis accounted for 22.49% in NMDA-induced neuronal death; (2) Pretreatment with p38 MAPK inhibitor SB203580 (10 μmol/L) significantly decreased NMDA-mediated caspase-3 activity by 30.43% (P < 0.05). However, ERK inhibitor PD98059 (20 μmol/L) or JNK inhibitor SP600125 (20 μmol/L) did not influence caspase-3 activity; (3) Pretreatment with SB203580 significantly reduced the number of NMDA-induced TUNEL-positive cells by 33.10% (P < 0.05). PD98059 (20 μmol/L) or SP600125 (20 μmol/L) did not show obvious effect; (4) Pretreatment with SB203580 (10 μmol/L) significantly reduced the number of NMDA-induced early apoptotic neurons by 55.56% (P < 0.05). Also, SP600125 (20 μmol/L) significantly decreased the amount of late apoptotic/dead cells by 67.59% (P < 0.05). There was no effect of PD98059 (20 μmol/L). These results indicate that: (1) NMDA induces neuronal apoptosis besides necrosis; (2) p38 MAPK, but not JNK and ERK, is involved in NMDA-induced neuronal apoptosis, and inhibition of the apoptotic signaling pathway contributes to neuroprotection; (3) JNK activation might contribute to NMDA-induced neuronal necrosis rather than apoptosis.

Neuroprotective role of silent information regulator 1 in Alzheimer's disease / 生理学报

Silent information regulator 1 (SIRT1), an NAD(+)-dependent deacetylase, is involved in the regulation of gene transcription, energy metabolism and cell aging. Recent studies have showed that SIRT1 possesses neuroprotective effects, however, it is not very clear how SIRT1 exerts the neuroprotection in Alzheimer's disease (AD). In this review, we summarized the neuroprotective role of SIRT1 in AD and its possible molecular mechanisms, proposing a novel strategy for preventing and treating neurodegeneration.

Activation of periphery group III metabotropic glutamate receptors inhibits formalin-induced activation of spinal p38-MAPK in rats / 中国应用生理学杂志

<p><b>AIM</b>To explore the effects of periphery injection of L-SOP on the activation of p38MAPK in spinal cord in formalin pain model in rats.</p><p><b>METHODS</b>Fourty-eight male Wistar rats were divided randomly into four groups (n=12): NS group and three different dose of L-SOP groups. For each group, 6 rats used to observe flinching and licking time every as nociception behavior 3 minutes in 1 hour after formalin injected and the other 6 rats used to observe the activation of p38(P-p38) by Western blotting.</p><p><b>RESULTS</b>All the three different groups of L-SOP could inhibit nociception behavior in the tonic phase,and 250 nmoVl/L and 500 nmol/L groups could suppress not only in the tonic phase but also in the acute phase. 250 nmol/L and 500 nmol/L groups could reduce activated or phosphorylated p38MAPK in spinal cord.</p><p><b>CONCLUSION</b>Periphery injection of L-SOP can reduce nociceptive behavior and phosphorylated p38MAPK in the spinal cord in formalin-induced hyperalgia, it is suggested that there is functional expression of mGluRs III in the periphery and is involved in the processing of peripheral noxious informations.</p>

Chitosan nanoparticles as gene vector: effect of particle size on transfection efficiency / 药学学报

The aim was to investigate the effect of particle size on transfection efficiency of chitosan (CS)-based nanoparticles. Nanoparticles were synthesized through complex coacervation CS with plasmid DNA (pDNA). Three kinds of pDNA/CS nanoparticles with different sizes (250, 580 and 1300 nm) were prepared by altering the adding rate and the vortexing time. The particle size, zeta potential and the stability in cultural medium were evaluated by zetasizer. The association efficiency was determined by spectrofluorophotometer. The combination of chitosan with pDNA as well as the ability to protect pDNA from nuclease degradation was analyzed by gel electrophoresis. The transfection efficiency of pDNA/CS nanoparticles in HEK293 cells was investigated by flow cytometry. Using CS grafted fluorescein isothiocyanate as a fluorescent marker, the adsorption features of the nanoparticles were visualized by fluorescence microscopy and the cellular uptake percent was quantitated by flow cytometry. The internalization process of the nanoparticles was visualized by confocal laser scanning microscopy (CLSM) using nanoparticles of the size of 250 nm. Results showed that the three kinds of pDNA/CS nanoparticles had no differences in zeta potential, association efficiency, protection ability, stability and transfection efficiency in HEK293. The nanoparticles were all adsorbed on cell surface in the form of aggregates, and similar cellular uptake percent as well as quantities were observed 4 h post-incubation with HeLa cells. CLSM images showed that the aggregates below 2 microm could be internalized by endocytosis. These results suggest that the transfection efficiency of pDNA/CS nanoparticles does not depend on particle size in the range from 250 nm to 1300 nm.