Objective To investigate mutations at HBV P gene RT region in lamivudine-resistant patients. Methods Serum samples were collected from 74 hepatitis B patients resistant to lamivudine. HBV P gene RT region was amplified by PCR, and the PCR products were directly sequenced and the viral loads were detected. Results There were 7 forms of mutations in 74 patients harboring YMDD mutations detected in this study. The common mutation forms were rtM204V/rtL180M, rtM204I and rtM204I/rtL180M. The most frequent mutation positions were rtM204I (38.7%), rtM204V (21.8%), rtL180M (38.7%) and rtV173L (0.8%). Conclusions The mutation forms and positions of lamivudine-resistant viral strains are complex. Common mutation forms and positions are not directly correlated with the viral load, but some novel forms may be associated with it.

Objective To explore the application value of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18 F-FDG PET/CT) and 99Tcm-methylene diphosphonate (99 Tcm-MDP) bone scintigraphy for detecting bone destruction in multiple myeloma (MM).Methods 18 F-FDG PET/CT and 99Tcm-MDP bone scintigraphy results of 27 MM patients were analyzed retrospectively.Inspection areas checked by magnetic resonance imaging (MRI) and X-ray were the limited scopes.The location and number of bone destruction were recorded,and the maximal standardized uptake value (SUVmax) was measured simultaneously.The results were comparatively analyzed.Diagnostic certainty regarding the presence or absence of bone destruction was evaluated according to the reference standard consisting of MRI and X-ray.Results A total of 235 lesions were found according to the reference standard.Of these,227 lesions (97％) were identified by 18F-FDG PET/CT,whereas 187 lesions (80％) were identified by bone scintigraphy,with a significant statistical difference (x2 =32.43,P ＜ 0.05).SUVmax was 8.3 ± 1.7 (4.3 to 18.9).The discovery rates of bone fracture of 18F-FDG PET/CT and bone scintigraphy were 100％ (97/97) and 90％ (87/97),and there was a significant statistical difference between them (x2 =78.09,P ＜ 0.05).Conclusion 18 F-FDG PET/CT is a possible method to detect bone lesions in patients with MM,and is better than 99Tcm-MDP bone scintigraphy.

ObjectiveTo investigate the effect of sevoflurane preconditioning on heme oxygenase-1 (HO-1) expression in lung tissues during one lung ventilation (OLV) in rats.MethodsTwenty-four male SD rats weighing 220-250 g were randomly divided into 4 groups ( n =6 each):control group (group C) ; two lung ventilation group (group T); OLV group (group O) and sevoflurane preconditioning+ OLV group (group SO).The animals were anesthetized with intraperitoneal pentobarbital sodium 40 mg/kg.In group T,the animals were tracheal intubated and bilateral lungs were ventilated for 1 h (VT 10 ml/kg,RR 60 bpt/min,I∶E 1∶2) and PETCO2 was maintained at 35-50 mm Hg.In groups O and SO,the animals were tracheal intubated and OLV was performed for 1 h (VT 5 ml/kg,RR 80 bpt/min,I:E 1:2) and PETCO2 was maintained at 35-50 mm Hg.In group SO,2.4％sevoflurane was inhaled for 30 min before OLV and then washed out by inhalation of oxygen for 15 min.The left lung tissues were removed in groups C and T,and the bilateral lung tissues were removed in groups.O and SO for microscopic examination and determination of wet/dry lung weight ratio (W/D ratio) and expression of HO-1 (by Western blot).Results Compared with group C,W/D ratio was significantly increased and the expression of HO-1 was up-regulated in left lung tissues in group T and in bilateral lung tissues in groups O and SO ( P ＜0.05).Compared with group T,W/D ratio was significantly increased and the expression of HO-1 was up-regulated in bilateral lung tissues in group O and in right lung tissues in group SO ( P ＜ 0.05).Compared with group O,W/D ratio was significantly decreased,the expression of HO-1 was up-regulated (P ＜ 0.05) and the pathological changes were reduced in bilateral lung tissues in group SO.ConclusionThe mechanism by which sevoflurane preconditioning reduces OLV-induced lung injury is related to up-regulation of HO-1 expression.

Objective To compare HC video-laryngoscope with Macintosh laryngoscope for tracheal intubation.Methods Sixty ASA Ⅰ or Ⅱ patients of both sexes,aged 18-64 yr,with body mass index 19-27 kg/m2,Mallampati grade Ⅰ-Ⅱ,undergoing elective surgery,were randomly divided into 2 groups (n =30 each):HC video-laryngoscope group (group H) and Macintosh laryngoscope (group M).After induction of anesthesia,the patients underwent orotracheal intubation assisted by HC video-laryngoscope in group H,and by Macintosh laryngoscope in group M.The glottic exposure time,intubation time,Cormack-Lehane grade,the number of pressing the cricoid and intubation-related complications were recorded.Results The rate of satisfactory glottic exposure was significantly higher and the number of pressing the cricoid was smaller in group H than in group M (P ＜ 0.05).There was no significant difference in the glottic exposure time,intubation time and incidence of intubation-related complications between the two groups (P ＞ 0.05).Conclusion The efficacy of tracheal intubation guided by HC video-laryngoscope is better than that guided by Macintosh laryngoscope.

[Objective] To investigate the mesenchymal stem cells (MSC) in treating acute lung injury (ALI) via ALI mouse model.[Methods] By monoclonal antibody Anti-GD2 of specific antigen ganglioside (GD2) only expressed on MSC as a carrier,new fluorescent molecule probe were synthesized through covalently coupling Anti-GD2 and fluorescent group CyDye mono-reactive NHS Esters (Cy7).Synthetic Anti-GD2-Cy7 and MSC were labeled by the specific binding of antigen and antibody in vitro.Total 84 balb/c male mice were selected and randomly selected 48 mice were divided into three groups:sham group (n =16),MSC+ ALI group (n =16),NS + ALI group (n =16).The lung histopathology and scores,lung W/D ratio and permeability of lung microvasculature were examined at 24 h,48 h after ALI mouse model.Other 36 mice were randomly divided into three groups:normal group (n =12),sham group(n =12),MSC +ALI group(n =12).Labeled MSC-GD2-Cy7 were transplanted into MSC+ALI group and sham group mice via tail vein injection.At 30 min,1 d,3 d,and 7 d post-MSC-GD2-Cy7 injection,the mice were sacrificed after anesthesia and then the lung was removed.Excised lung was detected on small animal fluorescent imager.[Results] Contrast to NS+ ALI group,the lung histopathology and scores,lung W/D ratio and permeability of lung microvasculature of MSC +ALI group were more greatly improved at both 24 h and 48 h.Fluorescent results showed that the signal intensity in thc lung of MSC +ALI group was significantly higher than that of sham group at each time point [(3.37 ± 0.02)× 10-4 vs (2.05 ± 0.04) × 10-4 scaled counts/s;(35.54 ± 0.47)× 10-4 vs (25.29 ± 1.48) × 10-4 scaled counts/s;(11.17 ± 0.75)×10-4 vs (6.09 ± 0.62)× 10-4 scaled counts/s;(3.10 ± 0.14) vs (0.00 ± 0.00)× 10-4 scaled counts/s;all P ＜ 0.05].[Conclusion] Our study showed that a proportion of cells migrated into normal and injured lungs 30 min after cell transplantation,and the cells started to recruit and largely gather in injured lungs at day 1 and persisted to day 7,these results suggest that MSC possess the ability to home into injured tissues.

Objective To study the dose-effect relationship and time-effect relationship of T cell receptor (TCR) gene mutation induced by γ-rays in lymphocytes of human peripheral blood.Methods Samples of peripheral blood were collected from 10 healthy adults and lymphocytes were separated.Four samples from males used to fit time-effect curve were exposed to γ-rays at the doses of 0,0.5,1.0,1.5,2.0,2.5,3.0,3.5,4.0,and 5.0 Gy,respectively,and 6 samples from 3 males and 3 females used to fit dose-effect curves were exposed to γ-rays of the dose of 2 Gy.Flow cytometry was used to detect the mutation frequency of TCR gene (TCR MF).Radiation dose-effect curves and time-effect curves were fitted and optimal mathematical models were selected respectively.Results The optimal mathematical model for radiation dose-effect was quadratic equation model:TCR MF = 92.14 + 22.61D2 (R2adj = 0.65).The optimal mathematical model for radiation time-effect was quadratic polynomial equation model:TCR MF = 3.74 + 743.66T + 308.64T2 (R2adj = 0.79).Conclusions TCR MF is increased as the γ-rayirradiation dose increases within the range of 0-5 Gy,and TCR MF is increased with the lapse of time within the range of 4 days after γ-ray radiation.

Objective To monitor the susceptibility of clinical isolates to antimicrobial agents in tertiary hospitals in major regions of China in 2022.Methods Clinical isolates from 58 hospitals in China were tested for antimicrobial susceptibility using a unified protocol based on disc diffusion method or automated testing systems.Results were interpreted using the 2022 Clinical &Laboratory Standards Institute(CLSI)breakpoints.Results A total of 318 013 clinical isolates were collected from January 1,2022 to December 31,2022,of which 29.5％were gram-positive and 70.5％were gram-negative.The prevalence of methicillin-resistant strains in Staphylococcus aureus,Staphylococcus epidermidis and other coagulase-negative Staphylococcus species(excluding Staphylococcus pseudintermedius and Staphylococcus schleiferi)was 28.3％,76.7％and 77.9％,respectively.Overall,94.0％of MRSA strains were susceptible to trimethoprim-sulfamethoxazole and 90.8％of MRSE strains were susceptible to rifampicin.No vancomycin-resistant strains were found.Enterococcus faecalis showed significantly lower resistance rates to most antimicrobial agents tested than Enterococcus faecium.A few vancomycin-resistant strains were identified in both E.faecalis and E.faecium.The prevalence of penicillin-susceptible Streptococcus pneumoniae was 94.2％in the isolates from children and 95.7％in the isolates from adults.The resistance rate to carbapenems was lower than 13.1％in most Enterobacterales species except for Klebsiella,21.7％-23.1％of which were resistant to carbapenems.Most Enterobacterales isolates were highly susceptible to tigecycline,colistin and polymyxin B,with resistance rates ranging from 0.1％to 13.3％.The prevalence of meropenem-resistant strains decreased from 23.5％in 2019 to 18.0％in 2022 in Pseudomonas aeruginosa,and decreased from 79.0％in 2019 to 72.5％in 2022 in Acinetobacter baumannii.Conclusions The resistance of clinical isolates to the commonly used antimicrobial agents is still increasing in tertiary hospitals.However,the prevalence of important carbapenem-resistant organisms such as carbapenem-resistant K.pneumoniae,P.aeruginosa,and A.baumannii showed a downward trend in recent years.This finding suggests that the strategy of combining antimicrobial resistance surveillance with multidisciplinary concerted action works well in curbing the spread of resistant bacteria.