Objective:To analyze the carriage status, subtype distribution and flanking gene sequence characteristics of oxacillinases (OXA enzyme) in 241 clinical strains of Pseudomonas aeruginosa, and assess their roles in the drug resistance of Pseudomonas aeruginosa and ability to horizontally transfer across species. Methods:Clinical P. aeruginosa isolates were collected from four hospitals in Sanya, Tangshan, Zhangjiakou, and Beijing. The prevalence of oxacillinases and their flanking gene sequences was analyzed by whole-genome sequencing (NGS) and bioinformatic approaches. Results:A total of 241 isolates of P. aeruginosa were gathered, and 35 blaOXA subtypes were identified through screening of 252 blaOXA genes. These genes were classified into three subfamilies: blaOXA-50-like (241, 95.6%), blaOXA-1-like (9, 3.6%) and blaOXA-10-like (2, 0.8%). Among these, 11 subtypes (11, 31.4%) were novel blaOXA subtypes. Nine of these belonged to the blaOXA-50-like subfamily and were designated as blaOXA-1244, blaOXA-1245, blaOXA-1246, blaOXA-1250, blaOXA-1252, blaOXA-1253, blaOXA-1254, blaOXA-1255, and blaOXA-1256. The remaining two belonged to the blaOXA-10-like subfamily and were named blaOXA-1247 and blaOXA-1248. Compared to the amino acid sequence of OXA-10, the newly identified subtype OXA-1247 exhibited a mutation at position 117, where a valine was replaced by a leucine. This change was thought to improve the enzyme′s ability to hydrolyze carbapenems. In the analysis of the flanking sequences of the blaOXA genes, Class I integrons were identified in four bacterial strains. The variable regions of these integrons carried three distinct patterns of resistance gene cassettes: aac( 6′) -Ib-blaOXA-1247-ant( 3′′) -Ia, aac( 6′) -Ib-blaOXA-1248 and aac( 6′) -Ib- blaIMP-45-blaOXA-1-catB3. Among these, the strain BJ2326 carried a class I integron that was connected to the downstream IS CR1 element to form a composite class I integron structure, additionally carrying the resistance gene blaPER-1. Out of the 223 non-wild-type P. aeruginosa strains, 127 strains exhibited non-wild-type profiles to the four beta-lactam antibiotics MEM, CAZ, FEP, and TZP, with the combination of MEM+CAZ+FEP being the most prevalent, representing 57.0% of the total. Conclusions:The blaOXA genes in 241 clinical P. aeruginosa strains showed diversity. Some blaOXA genes had a co-transfer risk with the metallo-β-lactamase resistance gene blaIMP-45. Among the 11 newly discovered blaOXA subtypes, the new subtype OXA-1247 may have carbapenemase activity and potential for horizontal transfer.

Objective:To analyze the three-dimensional radiographic characteristics of solid variant of odontogenic keratocyst(SOKC)using multi-slice spiral tomography(MSCT).Methods:Clinical records,histopathological reports and MSCT images of 8 patients were retrospectively acquired,radiographic features,including lesion site,size,borders,jaw expansion,internal structures and relationship with surrounding tissues were analyzed.Results:8 cases(4 males and 4 females)aged 37-65 years were included.Among them,4 lesions were located in the maxilla and the other 4 in mandible.Clinically,the lesions manifested as an enlargement of the affected area in the jaw bone,with pain present in 6 cases.On MSCT scans,all lesions showed evident jaw expansion.The boundaries of the lesions were clear in 3 cases,and unclear in 5 cases.4 cases exhibited multilocular radiolucent lesions,while the other 4 cases showed mixed radiolucent/opaque lesions resembling fibro-osseous lesion.The maxilla lesions involved the palate,na-sal cavity,maxillary sinus and orbital floor.All mandible SOKCs were recurrent and infectious,with involvement of the surrounding soft tissue.Conclusion:SOKC exhibits imaging characteristics that differentiate from conventional odontogenic keratocysts.Radio-graphically,it presents as a benign or low-grade malignant solid jaw mass.

Objective:To analyze the carriage status, subtype distribution and flanking gene sequence characteristics of oxacillinases (OXA enzyme) in 241 clinical strains of Pseudomonas aeruginosa, and assess their roles in the drug resistance of Pseudomonas aeruginosa and ability to horizontally transfer across species. Methods:Clinical P. aeruginosa isolates were collected from four hospitals in Sanya, Tangshan, Zhangjiakou, and Beijing. The prevalence of oxacillinases and their flanking gene sequences was analyzed by whole-genome sequencing (NGS) and bioinformatic approaches. Results:A total of 241 isolates of P. aeruginosa were gathered, and 35 blaOXA subtypes were identified through screening of 252 blaOXA genes. These genes were classified into three subfamilies: blaOXA-50-like (241, 95.6%), blaOXA-1-like (9, 3.6%) and blaOXA-10-like (2, 0.8%). Among these, 11 subtypes (11, 31.4%) were novel blaOXA subtypes. Nine of these belonged to the blaOXA-50-like subfamily and were designated as blaOXA-1244, blaOXA-1245, blaOXA-1246, blaOXA-1250, blaOXA-1252, blaOXA-1253, blaOXA-1254, blaOXA-1255, and blaOXA-1256. The remaining two belonged to the blaOXA-10-like subfamily and were named blaOXA-1247 and blaOXA-1248. Compared to the amino acid sequence of OXA-10, the newly identified subtype OXA-1247 exhibited a mutation at position 117, where a valine was replaced by a leucine. This change was thought to improve the enzyme′s ability to hydrolyze carbapenems. In the analysis of the flanking sequences of the blaOXA genes, Class I integrons were identified in four bacterial strains. The variable regions of these integrons carried three distinct patterns of resistance gene cassettes: aac( 6′) -Ib-blaOXA-1247-ant( 3′′) -Ia, aac( 6′) -Ib-blaOXA-1248 and aac( 6′) -Ib- blaIMP-45-blaOXA-1-catB3. Among these, the strain BJ2326 carried a class I integron that was connected to the downstream IS CR1 element to form a composite class I integron structure, additionally carrying the resistance gene blaPER-1. Out of the 223 non-wild-type P. aeruginosa strains, 127 strains exhibited non-wild-type profiles to the four beta-lactam antibiotics MEM, CAZ, FEP, and TZP, with the combination of MEM+CAZ+FEP being the most prevalent, representing 57.0% of the total. Conclusions:The blaOXA genes in 241 clinical P. aeruginosa strains showed diversity. Some blaOXA genes had a co-transfer risk with the metallo-β-lactamase resistance gene blaIMP-45. Among the 11 newly discovered blaOXA subtypes, the new subtype OXA-1247 may have carbapenemase activity and potential for horizontal transfer.

Objective:To analyze the three-dimensional radiographic characteristics of solid variant of odontogenic keratocyst(SOKC)using multi-slice spiral tomography(MSCT).Methods:Clinical records,histopathological reports and MSCT images of 8 patients were retrospectively acquired,radiographic features,including lesion site,size,borders,jaw expansion,internal structures and relationship with surrounding tissues were analyzed.Results:8 cases(4 males and 4 females)aged 37-65 years were included.Among them,4 lesions were located in the maxilla and the other 4 in mandible.Clinically,the lesions manifested as an enlargement of the affected area in the jaw bone,with pain present in 6 cases.On MSCT scans,all lesions showed evident jaw expansion.The boundaries of the lesions were clear in 3 cases,and unclear in 5 cases.4 cases exhibited multilocular radiolucent lesions,while the other 4 cases showed mixed radiolucent/opaque lesions resembling fibro-osseous lesion.The maxilla lesions involved the palate,na-sal cavity,maxillary sinus and orbital floor.All mandible SOKCs were recurrent and infectious,with involvement of the surrounding soft tissue.Conclusion:SOKC exhibits imaging characteristics that differentiate from conventional odontogenic keratocysts.Radio-graphically,it presents as a benign or low-grade malignant solid jaw mass.

Objective:To investigate the effect of highly active antiretroviral therapy(HAART) on thyroid function in adult patients with acquired immunodeficiency syndrome(AIDS).Methods:A cross-sectional retrospective study was conducted on 1 276 AIDS patients hospitalized in the Department of Infection, Guangzhou Eighth People′s Hospital from June 2017 to May 2020. General data, the first laboratory examination on admission, thyroid function, and related antibodies were collected and analyzed. A total of 176 patients were included in the study and divided into HAART group( n=83) and no-HAART group( n=93) according to whether they received HAART treatment. Results:Among 176 AIDS patients, the rate of thyroid dysfunction was 53.98%. It was significantly lower in the HAART group, compared with no-HAART group(40.96% vs 65.59%), with a statistically significant difference ( P=0.001). The course of AIDS, body mass index, CD4 + T lymphocyte count, free triiodothyronine, and serum creatinine in HAART group were significantly higher than those in no-HAART group, and aspartate aminotransferase was significantly lower than those in no-HAART group, with statistical significance(all P<0.05). There was no significant difference in age, sex, smoking history, free thyroxine, thyroid stimulating hormone, thyroid peroxidase antibody, thyroglobulin antibodies, and alanine aminotransferase between HAART group and no-HAART group(all P>0.05). The prevalence of low T 3 syndrome in HAART group was significantly lower than that in no-HAART group(14.46% vs 39.78%), and the difference was statistically significant( P<0.001). There was no significant difference in the prevalence of hyperthyroidism, hypothyroidism, and isolated low T 4 between HAART group and No-HAART group(all P>0.05). Multivariate logistics regression analysis showed that HAART was an independent protective factor for thyroid dysfunction and isolated low T 4 in AIDS patients. Conclusions:Thyroid dysfunction is a common endocrine disorder in AIDS patients that requires attention from infectious disease specialists. HAART therapy serves as a protective factor against thyroid dysfunction. Thyroid dysfunction mainly manifests as low T3 syndrome and requires continuous monitoring of thyroid function changes.

Objective:To analyze the clinical characteristics of patients with different types of coronavirus disease 2019 (COVID-19).Methods:A total of 272 eligible COVID-19 patients who were admitted to Guangzhou Eighth People′s Hospital, Guangzhou Medical University from January 22 to February 15, 2020 were retrospectively enrolled. General characteristics, the first laboratory examination and imaging data of these patients were collected. According to the clinical classification, there were 236 cases in non-severe group (mild+ common type) and 36 cases in severe group (severe+ critical type). Comparisons between groups were performed by t test, chi-square test or rank-sum test when appropriate. Results:There were 23 males and 13 females in the severe group, 103 males and 133 females in the non-severe group, and the difference was statistically significant ( χ2=5.149, P=0.023). The age of severe group was (60.5±11.2) years, which was higher than that of non-severe group (46.8±15.7) years. The difference was statistically significant ( t=6.43, P<0.01). The lymphocyte (LYM) count, platelet (PLT) count and arterial partial pressure of oxygen (PaO 2) in the severe group were 0.90(0.55, 1.10)×10 9/L, 170.00(143.50, 198.00)×10 9/L and 73.50(69.70, 83.00) mmHg(1 mmHg=0.133 kPa), respectively, which were all lower than those in the non-severe group (1.42(1.09, 1.95)×10 9/L, 187.00(148.00, 230.00)×10 9/L and 96.00(83.20, 108.00) mmHg, respectively). The differences were all statistically significant ( Z=5.59, 2.00 and 5.00, respectively, all P<0.05). The levels of creatine kinase (CK), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), C reaction protein (CRP) and procalcitonin (PCT) in the severe group were 123.00(79.00, 212.00) U/L, 32.10(27.00, 47.40) U/L, 305.50(216.00, 396.00) U/L, 37.02(23.92, 63.66) mg/L and 0.09(0.05, 0.19) μg/L, respectively, which were all higher than those in the non-severe group (68.00(48.00, 103.00) U/L, 20.10(16.70, 26.20) U/L, 179.00(150.00, 222.00) U/L, 26.55(18.11, 36.96) mg/L and 0.04(0.03, 0.06) μg/L respectively), and the differences were all statistically significant ( Z=3.89, 5.60, 5.12, 2.85 and 5.43, respectively, all P<0.01). No significant differences were observed in white blood cell count, creatine kinase isoenzyme and blood lactate between the two groups ( Z=1.53, 0.41 and 1.00, respectively, all P>0.05). Conclusion:Gender, age, LYM count, PLT count, PaO 2, CK, AST, LDH, CRP and PCT could be used to provide reference for clinical classification of COVID-19 patients.

OBJECTIVETo study the CPS-II mechanism underlying the pathological process of elevated blood ammonia leading to liver injury.

METHODSAn in vitro hyperammonemia hepatocyte cell model was constructed by exposure to various concentrations of NH4Cl. The subsequent changes to cellular morphology were observed by microscopy. to cell apoptosis were determined by flow cytometry, and to mRNA and protein expression of CPS-II were examined by real-time PCR and western blotting, respectively.

RESULTSExposure to NH₄Cl led to dose-dependent morphological damage, apoptosis and necrosis of the hepatocytes. The apoptosis rate was significantly higher for the high-dose group than for the control (no exposure) group (24.7% ± 2.39% vs. 4.1% ± 0.78%, q =8.06, P less than 0.05). Expression of the CPS-II mRNA was significantly elevated in response to NH₄Cl exposure (vs. the control group; F=191.881, P < 0.05).The CPS-II mRNA expression level increased with increasing NH₄Cl concentration (grey values: 1.040 ± 0.045, 1.641 ± 0.123, 2.285 ± 0.167 and 3.347 ± 0.124, respectively). The CPS-II protein expression level was also significantly enhanced in response to the NH₄Cl exposures (CPS-II protein and internal GAPDH grey value ratios: 0.099 ± 0.0130, 0.143 ± 0.025, 0.161 ± 0.036 and 0.223 ± 0.042, respectively; t=3.825, 3.968 and 6.908, P less than 0.05).

CONCLUSIONCPS-II mRNA and protein expression levels become elevated with increase in the NH₄Cl concentrations, suggesting that in addition to the urea cycle, CPS-II may play an important role in the ammonia metabolism under the condition of hyperammonemia.

Objective To explore the clinical value of serum procalcitonin (PCT)-based antibiotic therapy in the second-classedexacerbations of chronic obstructive pulmonary disease (AECOPD). Methods 240 patients diagnosised as AECOPD were randomized to the PCT group and the control group. Serum PCT levels of patients from the PCT group were measured 1 h after hospitalized and the third, fifth, eighth day respectively. When PCT < 0.1 μg / L, patients will stop taking antibiotics and initiated while PCT≥0.1 μg / L. Antibiotic treatment in the control group was based on guidelines of COPD diagnosis and treatment. Results Duration of antibiotic therapy and hospitalization were respectively 5.6 ± 1.4 and 8.2 ± 1.1 days in the PCT group, 9.2 ± 2.2 and 11.4 ± 2.5 days in the control group (both P < 0.05). Mean costs of hospitalization expensesand antibiotic therapy were 5700 ± 201 and 1650 ± 189) yuan in the PCT group, 6210 ± 220 and 2350 ± 210 yuan in the control group (both P < 0.05). The clinical effective rate, times of exacerbation, one-year ΔFEV1, the 1-year hospitalization rate and time to next exacerbation all showed no significant differences between the two groups. Conclusion PCT-guided antibiotic treatment reduces antibiotic use inthe second-classed acute exacerbations patients.

A total of 209 type 2 diabetic patients were divided into three groups:without,with mild to moderate,or severe diabetic lower extremity arterial disease based on the ankle brachial index value.60 healthy subjects were used as a control group.Retinol binding protein4 (RBP4),cystatin C,and biochemical parameters were determined in all subjects.The results showed that RBP4 and cystatin C levels were progressively raised with the increasing severity of lower extremity arterial disease in various groups,being significantly higher in patients with type 2 diabetes mellitus with mild to moderate and severe arterial disease compared with control group (P＜0.05 or P＜0.01).RBP4 and cystatin C levels in groups with lower extremity arterial disease were significantly higher than those in the group without arterial disease (P＜0.01).Pearson correlation analysis showed that RBP4 level was positively correlated with total cholesterol,triglyceride,low density lipoprotein-cholesterol,fasting serum insulin,body mass index,cystatin C etc while negatively correlated with high density lipoprotein-cholesterol (P＜0.05 or P＜0.01).Logistic regression analysis showed that serum RBP4 and cystatin C were significantly associated with lower extremity arterial disease in type 2 diabetes mellitus.

Objective To study the protective effect of ROP2 nuclei acid vaccine in mice.Methods Forty-two BALB/c mice were divided into three groups.Each mouse in experiment group was injected with 50 ?g recombinant plasmid pc-DNA3-ROP2 through musculus quadriceps fexoris.In control groups,each mouse was injected with 50 ?g blank plasmid pc-DNA3 and with 50 ?l PBS respectively.All mice were immunized for three times with an interval of three weeks.The volume was doubled for the final injection in the two plasmid groups.Blood,spleens and lymph nodes of 4 mice in each group were taken for the detection of CD4+,CD8+ T cells and cytokines 2 weeks after the final immunization.The rest mice in 3 groups were challenged with 500 tachyzoites of Toxoplasm gondii RH strain for further observation.Results The vaccine induced strong cellular and humoral immune response.The titer of antibody in serum was high after inoculation and recognized ROP2 protein antigen expressed in vitro.The lymphocyte phenotype was analyzed.CD4+ T cells proliferated sharply(69.5?3.4)%,and the ratio of CD4+/CD8+ increased considerably by(4.69?1.32)%(P