[Molecular mechanisms of quinolone resistance in non-typhoidal Salmonella].

By conducting retrospective analysis, this study aim to investigate the resistance mechanism of quinolones in non-typhoidal Salmonella (NTS). A total of 105 strains of NTS isolated from clinical specimens from the Fifth Affiliated Hospital of Southern Medical University from May 2020 to February 2021 were used as research objects. VITEK2 Compact automatic identification drug sensitivity analysis system and serological test were used to identify the strains. The sensitivity of the strains to ciprofloxacin, levofloxacin and nalidixic acid was detected by AGAR dilution method. The whole genome of 105 strains of NTS was sequenced. Abricate and other softwares were used to analyze drug-resistant genes, including plasmid-mediated quinolone resistance gene (PMQR) and Quinolone resistance determination region (QRDR). Serotypes and ST types were analyzed using SISTR and MLST, and phylogenetic trees were constructed. The results showed that the NTS isolated in this region were mainly ST34 Salmonella typhimurium (53.3%). The drug sensitivity results showed that the drug resistance rates of NTS to ciprofloxacin, levofloxacin and nalidixic acid were 30.4%, 1.9% and 22.0%, respectively, and the intermediate rates of ciprofloxacin and levofloxacin were 27.6% and 54.2%.A total of 46 (74.2%) of the 62 quinolone non-susceptible strains carried the PMQR gene, mainly qnrS1 (80.4%), followed by aac(6')-Ib-cr(15.2%); there were 14 NTS and 8 NTS had gyrA and parC gene mutations, respectively. The gyrA was mutations at the amino acid position 87, Asp87Tyr, Asp87Asn, Asp87Gly, and Thr57Ser mutations were detected in parC. In conclusion, this study found that NTS had relatively high resistance to quinolones, carrying qnrS1 gene mainly resulted in decreased sensitivity of NTS to ciprofloxacin and levofloxacin, and gyrA:87 mutation mainly resulted in NTS resistance to Nalidixic acid; Salmonella typhimurium in clinical isolates showed clonal transmission and required further epidemiological surveillance.

[Diagnostic and predictive values of three criterias of acute kidney injury in children with chronic kidney disease].

Objective: To compare the consistency in diagnosing and staging acute kidney injury (AKI) in children with chronic kidney disease (CKD) according to three criterias. Methods: Children with CKD hospitalized in the First Affiliated Hospital of Sun Yat sen University from January 2013 to December 2019 were analyzed retrospectively. These patients underwent serum creatinine examination more than twice during hospitalization. The AKI diagnosis and staging were performed for each patient according to the 2007 pRIFLE, 2012 KDIGO and 2018 pROCK criteria respectively. All the children were followed up for 1 year after discharge through outpatient visit, re-hospitalization or online consultation. The clinical characteristics and prognosis of CKD children with or without AKI that were diagnosed by 3 criteria were compared. Analysis of variance and chi-squared tests were used for the comparison among groups. Concordance between the different diagnostic criteria was evaluated using Cohen's kappa coefficient. Result: A total of 2 551 children with CKD were included in this study, with an age of (8±4) years. There were 1 628 boys and 923 girls. Nephrotic syndrome was the most prevalent primary disease (55.4%), followed by lupus nephritis (11.2%) and purpura nephritis (8.2%). Among all stages of CKD, CKD category G1 was the most common type (2 146 cases, 84.1%), followed by CKD category G2 (221 cases, 8.7%). AKI occurence rates according to pRIFLE, KDIGO and pROCK criteria were 33.9% (866/2 551), 26.2%(669/2 551) and 19.5% (498/2 551) respectively (χ²=136.3,P<0.01). The diagnostic consistency within three criteria for AKI was high in children with CKD (κ=0.702), but AKI staging consistency was low (κ=0.329). Both the diagnosis and staging consistency of three AKI criteria were poor in children with CKD category G5 (all κ<0.400). The length of hospital stay (LOS), hospitalization costs, the occurence of intensive care unit (ICU) admission and in-hospital mortality were significantly higher in children with AKI diagnosed by different criteria (P<0.05). After 1-year follow-up, the repeated admission rate and CKD staging progress significantly increased in children with AKI (P<0.05). In children with baseline serum creatinine≥200 µmol/L, compared with children who did not experience AKI during hospitalization, the LOS and the hospitalization costs in children who were diagnosed AKI according to pRIFLE or pROCK criteria was significantly higher (P<0.05). However, there was no significant difference in the LOS and hospitalization costs between children with or without AKI who were diagnosed according to KDIGO criteria (all P>0.05). Conclusions: AKI diagnosed by all of the three criteria (pRIFLE, KDIGO and pROCK criteria) was associated with the poor prognosis in children with CKD. However, in those whose baseline serum creatinine≥ 200 µmol/L, AKI diagnosed by pRIFLE and pROCK criteria could better reflect the poor outcomes than by KDIGO criteria.

Evaluation of a second-generation monoenergetic reconstruction algorithm for lesion contrast and venous invasion in pancreatic ductal adenocarcinomas.

OBJECTIVE: At lower energy levels, virtual monochromatic imaging by dual-energy computed tomography improves lesion attenuation but produces greater image noise with the conventional monoenergetic reconstruction algorithm (Mono). Recently, a second-generation algorithm (Mono+) was introduced to overcome this limitation. We compared the quality of images obtained with these algorithms and investigated the optimal energy selection for pancreatic ductal adenocarcinomas (PDACs). PATIENTS AND METHODS: Image data from 54 PDAC cases were generated at 40, 50, 60, 70, and 80 keV using Mono and Mono+. Image quality was objectively assessed by comparing the signal-to-noise ratios (SNRs), noise, and the contrast-to-noise ratios (CNRs) at different keV levels and between these algorithms at the same keV level. Lesion conspicuity and venous invasion were subjectively assessed. RESULTS: For Mono, the mean pancreas and tumour SNRs peaked at 70 keV (p<0.001). The noise increased as the energy level decreased (p<0.001). CNRtumour remained unchanged. For Mono+, the mean pancreas SNR peaked at 40 keV (p<0.001). The mean tumour SNR and noise remained unchanged. The tumour CNRs were highest at 40 keV (4.9 times the CNR of Mono 40 keV, p<0.001). Subjectively, lesion conspicuity was best at Mono+ 40 keV (p<0.001) and it showed higher diagnostic performance levels on venous invasion assessment against Mono. CONCLUSIONS: Mono+ produced better image quality, and 40 keV is recommended for the diagnosis of PDAC.

Can we make an accurate diagnosis of pyriform sinus fistula by fetal MRI?

AIM: To review the fetal magnetic resonance imaging (MRI) features of pyriform sinus fistula (PSF) and to compare them with the postnatal clinical and surgical findings. The relevant medical literature is also discussed. MATERIALS AND METHODS: The location, shape, signal, effects of adjacent structures and in utero changes detected on fetal MRI were reviewed in three cases of PSF. The patient's respiratory status at birth, the application of ex utero intrapartum therapy (EXIT), infectious complications in the neonatal period, and the surgical and pathological findings were also reviewed and discussed. The study consisted of three pregnant women between 18 and 38 years of age, each with a single fetus. Fetal MRI was performed at 26 and 38 weeks of gestation in case 1, at 34 weeks of gestation in case 2, and at 34 and 38 weeks of gestation in case 3. Postnatal clinical follow-up extended from 9 months to 3 years. RESULTS: All lesions were well-circumscribed unilobular cysts with slightly thickened walls at the neck area. Case 1 was irregular in shape, and the other two cases were oval and extended longitudinally along the neck. The fluid contents showed signals consistent with amniotic fluid. Close contact with the thyroid gland was demonstrated to be a fairly characteristic feature that could be recognised on fetal MRI. The in utero follow-up detected slight changes in the signal, wall characteristics, contour, and airway deviation. Case 1 was bilaterally affected, causing it to be initially mistaken as macro-cystic lymphangioma. The diagnosis was corrected with the aid of postnatal imaging; however, a prenatal diagnosis was correctly made in cases 2 and 3. Airway obstruction was not observed in any of the three cases, and thus, EXIT was not applied. The fetal MRI findings were in good agreement with the postnatal clinical and surgical findings. In addition to the higher spatial delineation provided by fetal MRI, as described in the literature, the observation of close contact with the thyroid gland and a flattened deformity of the thyroid gland are other characteristic features. CONCLUSION: Fetal MRI is useful for displaying characteristics of PSF that can enable an accurate prenatal diagnosis.

[Effect of the Chinese Herbal Medicinal Ingredients in Huoxiang Zhengqi Liquid on Alcohol Metabolism in Rats].

OBJECTIVES: To study the changes of alcohol content and pharmacokinetic parameter in rats after taking Huoxiang Zhengqi liquid. METHODS: The rats were randomly divided into three groups and given with white alcohol at the dose of 3.0 mL/kg, low-dose and high-dose Chinese medicine liquor, respectively. The blood was collected before administration and 5 min, 10 min, 15 min, 30 min, 1 h, 2 h, 3 h, 4 h, 5 h, 6 h and 8 h after administration by cutting rats' tails. The concentrations of alcohol in blood were detected by headspace-gas chromatography method. The main pharmacokinetic parameters were calculated by DAS 2.0, and then analyzed by SPSS 17.0. RESULTS: The difference of maximum blood concentrations between high-dose Chinese medicine alcohol group and white alcohol group was statistically significant （P<0.05）. There was no significant difference in other pharmacokinetic parameters among three groups （P>0.05）. CONCLUSIONS: The Chinese herbal medicinal ingredients in the Huoxiang Zhengqi liquid has no effect on the metabolism and elimination of ethanol in rats. The research provides useful reference for the qualitative assessment and processing of traffic accident cases involved in Huoxiang Zhengqi liquid and the studies related to drug-interaction.