Abstract: Objective　To determine the rate of nasal carriage Staphylococcus aureus among healthcare workers in Department of Infectious Diseases department of the First Affiliated Hospital of Xi'an Jiaotong University Hospital, and to perform characterization on isolated strains. Methods　A cross-sectional study was performed on 86 healthcare workers from February 2022 to June. Nasal swabs were collected from the healthcare workers, and S. aureus were identified after incubation. Antibiotic susceptibility, including chlorhexidine and mupirocin, was assessed by disk diffusion and minimal inhibitory concentration method. The PCR technique was used to detect the biocide resistance genes (qacAB, smr, lmrS mepA, and sepA), virulence genes (pvl, fnbA/fnbB, sea, seb, sec, sed, tst, eta, etb) and mecA gene. SCCmec typing and multilocus sequence typing was performed. For mupirocin-resistant strains, PCR amplification and sequencing were used to identify whether the strains had ileS gene mutations or carried resistant genes (mupA and mupB). Results　S. aureus was isolated from 37 of the 86 healthcare workers (43.02%) , including 13 methicillin-resistant Staphylococcus aureus (MRSA) strains. The strains showed low resistance rates to levofloxacin (2.70%, 1/37), chloramphenicol (8.11%, 3/37), tetracycline (8.11%, 3/37), gentamicin (10.81%, 4/37), and ciprofloxacin (10.81%, 4/37). A total of 17 strains were identified as multidrug-resistant strains. Four SCCmec types were identified in MRSA strains, with the type II being the most frequent (53.85%, 7/13), followed by type IV (30.77%, 4/13). ST59 (46.15%, 6/13) was the most frequent among MRSA strains, while ST5 (41.67%, 10/24) was the most frequent among methicillin-susceptible S. aureus (MSSA) strains. sea was the most frequent virulence gene (56.76%, 21/37). sepA and mepA were detected in all 37 isolates. One Staphylococcus aureus strain was not sensitive to chlorhexidine, two strains had the missense mutation V588F (G1762T) and showed low level resistance to mupirocin, and one strain carrying mupA gene was highly resistant to mupirocin. Conclusion　The nasal colonization rate of Staphylococcus aureus among healthcare worker in the investigated hospital was high, indicating a risk for nosocomial infections. Strengthened monitoring and decolonization treatment should be carried out to reduce these risks.

Whennearinfraredspectroscopyisappliedtoon-linemonitoringandcontroloftobaccoflavors,the variation in temperature can severely deteriorate the predictive performance of near infrared spectroscopic calibration models and results in a significant increases of the root mean square error value for the main constituents in syrup samples from 2. 4% to 29. 0%. In this paper, near infrared spectroscopy has been incorporated with an advanced calibration transfer method-loading space standardization to effectively eliminate the deteriorate effects of temperature variation on quantitative results and finally realize the fast and accurate on-line quantitative monitoring and control of tobacco flavors. The root mean square error value for the main constituents in syrup samples is successfully retained at a satisfying low level of 3 . 8%. The results of this paper will provide technical support for the preparation, preservation and use of tobacco flavors, and realize on-line process quality control of cigarettes.

Objective To investigate changes in CD_4~+ CD_(28)~(null)T cell numbers of peripheral blood and the expression of perforin in patients with coronary heart disease.Methods Sixty-eight patients with acute coronary syndromes,56 with stable angina and 65 healthy subjects were enrolled in the study.CD_4~+ CD_(28)~(null)T lymphocytes were measured by flow cytometric analysis.Results The numbers of CD_4~+ CD_(28)~(null)T lymphocytes in patients with acute coronary syndromes were higher than those in patients with stable angina and in the control subjects(11.6 % vs 2.84% and 0.59%,P

Objective To explore mutation diagnosis and discuss the pathogenic and clinical characteristics of neurofibromatosis type 1 (NF1).Methods DNA sequencing combined with denaturing highperformance liquid chromatography (DHPLC) method was used to diagnose patients and parents.Results A new nonsense mutations c.503C ＞ G(p.S168 *) was identified.Conclusions NF1 is a rare autosomal dominant genetic disease.Most of them are caused by new mutations.Genetic diagnosis of sporadic cases is very important for treatment and the future generations.

OBJECTIVETo investigate the effect of nuclear receptor inhibitor importazole (IPZ) on cell cycle and apoptosis of multiple myeloma (MM) cells and its regulatory mechanisms.

METHODSMM cell lines RPMI 8226 and NCI-H929 cells were treated with different concentrations of IPZ. Cell viability was detected through MTT method. Cell cycle and apoptosis were measured by flow cytometry (FCM). Nuclear NF-κBprotein expression was tested by Western blot. Electrophoretic mobility shift assay (EMSA) was used to analyze the DNA binding activity.

RESULTSIPZ induced a dose- and time- dependent inhibition of myeloma cells growth. And the IC50 values of IPZ on RPMI 8226 and NCI-H929 after 48 hours incubation were (4.43±0.41) and (4.78±0.35) μmol/L, respectively, and the percentages of S phase cells decreased from (54.95±4.34)％ and (51.38±2.43)％ to (42.77±3.19)％ and (40.98±6.46)％, respectively. After treatment with IPZ at 8, 12 and 16 μmol/L, the apoptosis rate significantly increased from (2.47±0.60)％ of the control group to (14.53±0.90)%, (32.57±1.80)% and (58.3±1.9)% (P<0.05) in RPMI 8226 and from (2.37±0.70)％ of the control group to (19.46±0.70) %, (46.02±1.10) % and (60.63±1.60)% in NCI-H929, respectively. Treatment of RPMI 8226 and NCI-H929 cells with 8 μmol/L IPZ for 24 h could inhibit NF-κB import to nucleus and reduce its DNA binding activity.

CONCLUSIONThe nuclear receptor inhibitor importazole inhibits proliferation and induces apoptosis of multiple myeloma cells by blocking the NF-κB signal pathway in vitro.

Apoptosis ; drug effects ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Humans ; Multiple Myeloma ; metabolism ; pathology ; NF-kappa B ; metabolism ; Quinazolines ; pharmacology ; Signal Transduction ; drug effects

This study was conducted to investigate the paclitaxel loaded by hydrazone bonds in poly(ethylene glycol)-poly(caprolactone) micelles (mPEG-PCL-PTX) on proliferation and apoptosis of human lung cancer A549 cells and its possible mechanisms of anti-tumor activity. The cell proliferation was measured with MTT assay. Flow cytometry were used to analyze the cell cycle. The cell apoptosis was analyzed using Hoechst/P staining. The expression levels of apoptotic genes expression in the mitochondrial apoptosis pathway were detected by RT-PCR and Western blotting, respectively. The mPEG-PCL-PTX could inhibit the proliferation of A549 cells and promote the apoptosis. The Bax, caspase-3 protein expression were increased while Bcl-2 protein expression was decreased in A549 cells. Results showed that the polymer containing hydrazone bond is non-toxic in vitro, the mPEG-PCL-PTX micelles can inhibit the proliferation and induce the apoptosis of A549 cells. Key words: paclitaxel; micelle; A549 cell; proliferation; cell cycle; apoptosis
Apoptosis ; Caspase 3 ; metabolism ; Cell Line, Tumor ; drug effects ; Cell Proliferation ; Humans ; Lung Neoplasms ; metabolism ; pathology ; Micelles ; Paclitaxel ; pharmacology ; Polyesters ; Polyethylene Glycols ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; bcl-2-Associated X Protein ; metabolism

Objective:To study the dynamic changes of cellular immune function in peripheral blood of trauma patients and its role in the evaluation of traumatic complications.Methods:A prospective cohort study design was conducted. Patients with blunt trauma admitted to Chongqing Emergency Medical Center from November 2019 to January 2020 were consecutively enrolled. The peripheral blood samples were collected at 1, 3, 5, 7, and 14 days after injury. The expressions of CD64, CD274, and CD279 on the surface of neutrophils, lymphocytes, and monocytes as well as CD3 +, CD4 + and CD8 + T lymphocyte subsets were measured by flow cytometry. The trauma patients were divided into different groups according to the injury severity score (ISS) and sepsis within 28 days after injury, respectively. The dynamic changes of cellular immune function in different time points after injury and differences between different groups were compared. Furthermore, the correlation with acute physiology and chronic health evaluation Ⅱ (APACHEⅡ), sequential organ failure assessment (SOFA), and ISS were evaluated by Pearson correlation analysis. Results:A total of 42 patients with trauma were finally enrolled, containing 8 severe trauma patients with ISS greater than 25 scores, 17 patients with ISS between 16 and 25 scores, and 17 patients with ISS less than 16 scores. The sepsis morbidity rates were 14.3% (n = 6) within 28 days after injury. CD64 index and CD4 +T lymphocyte subsets were significantly increased at different time points after trauma (H = 15.464, P = 0.004; F = 2.491, P = 0.035). The CD64 index and positive rates of CD279 in neutrophils, lymphocytes, and monocytes were increased with the severity of injury at day 1 and day 3 after injury, respectively. At the first day after injury, CD64 index were 2.81±1.79, 1.77±0.92, 3.49±1.09; positive rate of CD279 in neutrophils were 1.40% (0.32%, 2.04%), 0.95% (0.44%, 2.70%), 12.73% (3.00%, 25.20%); positive rate of CD279 in lymphocytes were 3.77% (3.04%, 5.15%), 4.71% (4.08%, 6.32%), 8.01% (4.59%, 11.59%); positive rate of CD279 in monocytes were 0.57% (0.24%, 1.09%), 0.85% (0.22%, 1.25%), 6.74% (2.61%, 18.94%) from mild to severe injury groups, respectively. The CD64 index in severe injury group was significantly higher than that in moderate group, and the positive rates of CD279 in neutrophils, lymphocytes and monocytes of severe injury patients were higher than those in other two groups (all P < 0.05). At 3rd day after injury, compared to moderate group, severe injury patients had significantly higher CD64 index and positive rate of CD279 in lymphocytes [4.58±2.41 vs. 2.43±1.68, 7.35% (5.90%, 12.28%) vs. 4.63% (3.26%, 6.06%), both P < 0.05]. Compared with the non-sepsis patients, the sepsis patients had significantly higher CD64 index and positive rate of CD279 in monocytes at day 1 after injury [4.06±1.72 vs. 2.36±1.31, 3.29% (1.14%, 12.84%) vs. 0.67% (0.25%, 1.48%), both P < 0.05], and positive rate of CD279 in lymphocytes significantly higher at 3rd day after injury [8.73% (7.52%, 15.82%) vs. 4.67% (3.82%, 6.21%), P < 0.05]. In addition, correlation analysis showed that positive rate of CD279 in lymphocytes was positively correlated with SOFA and ISS, respectively (r values were 0.533 and 0.394, both P < 0.05), positive rate of CD279 in monocytes was positively correlated with APACHEⅡ, SOFA and ISS scores, respectively (r values were 0.579, 0.452 and 0.490, all P < 0.01), positive rate of CD279 in neutrophils was positively correlated with APACHEⅡ and ISS, respectively (r values were 0.358 and 0.388, both P < 0.05). Conclusions:CD64 index and CD279 expression in neutrophils, lymphocytes, and monocytes are significantly related to the severity and prognosis of trauma. Dynamic monitoring the cellular immune function may be helpful for assessing the prognosis of trauma patients.

OBJECTIVETo investigate the clinical and molecular genetics characteristics of a patient with mild androgen insensitivity syndrome (MAIS).

METHODSClinical data of the patient was collected, and DNA was isolated from peripheral blood sample. Eight exons of AR gene were amplified by PCR with specific primers and directly sequenced by Sanger method. The results were compared with standard sequences from GenBank. Online Polyphen-2 software was applied to predict the effect of mutation on the protein function and compare the conservation of the sequence at the mutation site in various species. The exon of the AR gene containing the mutated site was analyzed in 90 unrelated normal males using PCR and restrictive digestion with Sfa NI.

RESULTSSequence analysis has detected a novel missense mutation in codon 176 of exon 1 (Ser176Arg) of the AR gene. Analysis with polyphen-2 software has indicated the codon to be highly conserved across various species, and that the S176A mutation has caused damage to the protein structure and function (prediction score=0.999). The same mutation was not detected in 90 healthy males.

CONCLUSIONThe S176A mutation of the AR gene may contribute to the mild androgen insensitivity syndrome.

Adult ; Amino Acid Sequence ; Androgen-Insensitivity Syndrome ; genetics ; Humans ; Male ; Molecular Sequence Data ; Mutation ; Receptors, Androgen ; genetics

OBJECTIVETo detect SCN4A gene mutation in a pedigree with paramyotonia congenita in order to facilitate genetic counseling and assisted reproduction.

METHODSClinical data of the family was collected. DNA was extracted from peripheral blood samples. Potential mutation of the SCN4A gene was screened using PCR-Sanger sequencing. Potential mutation was detected in 3 affected relatives, 4 unaffected relatives and 100 unrelated healthy controls. Bioinformatics software was used to predict the effect of mutation on the protein function and conservation of the sequence at the mutation site across various species.

RESULTSA novel missense mutation c.4427T>C (p.Met1476Thr) was detected in the exon 24 of the SCN4A gene in the proband and other 3 affected relatives, but not in 4 unaffected relatives and 100 unrelated controls. Bioinformatic analysis indicated that the codon is highly conserved across various species, and that the mutation has caused damage to the structure and function of SCN4A protein.

CONCLUSIONThe c.4427 T>C (p.Met1476Thr) mutation of the SCN4A gene may contribute to the paramyotonia congenita. Detection of SCN4A gene mutation is an effective method for the diagnosis of paramyotonic congenita.

Adult ; Amino Acid Sequence ; Asian Continental Ancestry Group ; genetics ; Base Sequence ; China ; Exons ; Female ; Humans ; Male ; Middle Aged ; Molecular Sequence Data ; Mutation, Missense ; Myotonic Disorders ; genetics ; NAV1.4 Voltage-Gated Sodium Channel ; genetics ; Pedigree ; Point Mutation ; Sequence Alignment

The quality of higher medical education is generally concerned and valued in medical education systems of various countries.Postgraduate tutors play a very important role in higher medical education and tutor quality is directly related to the quality of postgraduate education.The article summarizes experience and knowledge of years in medical postgraduate education management and construction of supervisor team work and discusses how to strengthen the construction of postgraduate tutor team of higher medical education combined with examples.The article points out the problems and defects in the construction of the current tutor team and puts forward practical and constructive suggestions for the reference of higher education management counterparts.