Molecular beacon probe was designed based on a specific DNA sequence of Nocardia to PCR detection of thisbacterium.The strains of Nocardia、Gordina and Rhodococcus were inoculated in Brain Heart Infusion Agar medium separately,then the growth condition was observed,DNA was extracted as a template;the molecular beacon probe was designed based on the partial secA 1 gene sequences of Nocardia strains,and the probe was added into the reaction system of real time fluorescence quantitative PCR (RT-PCR),and the fluorescence signal was tested at the end of PCR.Showed that the amplified secA1 gene of Nocardia could produce positive fluorescence signal in RT-PCR,but those of Gordonia and Rhodococcus with control groups showed negative results because of no fluorescence signal.In conclusion as a housekeeping gene,secA1 is an ideal target molecule to identify the actinomycetes strains on the species level in the systematic evolution research,and the technique of fluorescence molecular beacon probe is accurate,rapid and sensitive for detecting the Nocardia strains with secA1 gene.

Objective To establish the fingerprints of QiangliDingxuan tablets(QLDX),determine their pharmacody-namic indexes of vasodilation and study the spectrum-effect relationships between the chemical components of QLDX and the property of vasodilation.Methods The rate of vascular relaxation was used as an index to evaluate the extent to which QLDX relaxed isolated superior mesenteric artery ring.The Grey correlation degree and partial least square regression(PLSR)were used to analyze"spectrum-effect"correlations before components with greater contribution to drug efficacy were screened out.Results There were 21 common peaks in the HPLC fingerprint of QLDX,and the similarity exceeded 0.88.A comparison with the chromatogram of the reference substance revealed 14 characteristic peaks.Vasodilative experiments showed that all the 10 batches of samples had vasodilatory effects.The correlation between the 21 chromato-graphic peaks was greater than 0.73.PLSR showed that 11 components were positively correlated with the vasodilatory effect.Six known compounds included parishin A,parishin C,5-hydroxymethylfurfural,luteolin,Linarin and ligustrazine.Conclusion The vasodilatory effect of QLDX results from the combined action of multiple components.Parishin A,parishin C,5-hydroxymethylfurfural,luteolin,Linarin and ligustrazine are positively correlated with this effect,which may be the main pharmacodynamic substance basis of vascular relaxation.

BackgroundNegative effects of mobile phone addiction on undergraduate students have led to several health problems including depression， anxiety， attention deficit disorder， cognitive impairment and sleep disturbance. The undergraduate nursing students serve as an important reserve force of the clinical nursing work， and their poor psychological health would have a non-ignorable impact on the quality of the nursing work and the nurse-patient relationship in the future. ObjectiveTo investigate the relation between neuroticism and tendency of mobile phone addiction among undergraduate nursing students， and to examine the pathways through which perceived stress and self-control play a role in the relation by constructing a chain-mediated model. MethodsFrom February to March 2023， a total of 900 undergraduate nursing students across 10 universities in Xi'an， Shaanxi Province were selected through convenient sampling method. Several scales were adopted to assess undergraduate nursing students respectively， including the neuroticism subscale of Eysenck Personality Questionnaire-Revised Short Scale for Chines （EPQ-RSC）， Perceived Stress Scale （PSS）， Self-Control Scale （SCS） and Mobile Phone Addiction Tendency Scale （MPATS）. The assessment were conducted on multiple aspects of these students including neurotic personality， subjective stress， self-control and mobile phone addiction tendency. Model 6 in the SPSS Macro Process 4.1 was used to examine the mediating effect of perceived stress and self-control between neuroticism and mobile phone addiction tendency among undergraduate nursing students. Results① Among the 900 students， 314 cases （34.89%） were found to be addicted to mobile phones. ② The score of neuroticism subscale in EPQ-RSC of nursing undergraduates was positively correlated with the total scores of PSS and MPATS （r=0.400， 0.287， P<0.01）， and negatively correlated with score of SCS （r=-0.364， P<0.01）. The total score of MPATS was positively correlated with the total score of PSS （r=0.362， P<0.01）， and negatively correlated with the total score of SCS （r=-0.468， P<0.01）. The total score of SCS was negatively correlated with the total score of PSS （r=-0.515， P<0.01）. ③ Perceived stress and self-control performed partial mediation between neuroticism personality and mobile phone addiction tendency （with indirect effect values of 0.056 and 0.065， respectively， accounting for 19.72% and 22.89% of the total effect）. Perceived stress and self-control played a chain mediating role between neuroticism personality and mobile phone addiction tendency （with an indirect effect value of 0.064， accounting for 22.54% of the total effect）. ConclusionNeuroticism personality， perceived stress and self-control are confirmed to play important roles in mobile phone addiction tendency among undergraduate nursing students. Neuroticism personality not only directly affects the tendency of mobile phone addiction， but also affects their mobile phone addiction tendency through the chain mediating effect of perceived stress and self-control.［Funded by The 2020 Annual Project of the 13th Five-Year Plan of Education Science in Shaanxi Province （number， SGH20Y1386）］

OBJECTIVE: To explore the role of bone marrow niche in the chemotherapy resistance of patient with acute myeloid leukemia (AML), and to investigate the effects of the MSCs on the apoptosis of HL-60 cell and its underlying mechanisms. METHODS: MSCs were derived from the bone marrow of newly diagnosed AML patients (AML-MSCs) and health donors(MSCs) were co-cultured with HL-60 cells respectively. The apoptosis of HL-60 cells in the presence/absence of MSCs and/or Daunorubicin were determined by flow cytometry with Annexin V/PI double staining. In addition, the morphological features of HL-60 cells were observed by Wright-Giemsa staining, and the ratio of blasts and differentiated cells were counted. Furthermore, the expressions of apoptosis-related factors including Caspase-3, Caspase-8,Caspase-9 and Survivin were detected by Western blot. RESULTS: The flow cytometry showed that there was no significant change in apoptosis of HL-60 cells co-cultured with MSC derived from healthy donors or AML patients. After adding Daunorubicin into different cultural systems, the apoptotic rates of HL-60, HL-60 co-cultured with normal MSCs and HL-60 co-cultured with AML-MSCs were (49.57±7.44)%, (30.72±4.05)% and (22.99±4.08)%, respectively, which showed that normal MSCs and AML-MSCs could remarkably supress Daunorubicin-induced HL-60 apoptosis, however, there was no statistically significant difference of apoptosis between HL-60 co-cultured with normal MSCs and HL-60 co-cultured with AML-MSCs. Wright-Giemsa staining showed that most of the HL-60 cells co-cultured with AML-MSCs were primitive, and cell differentiation was unusual. In AML-MSCs co-cultured group, the cell apoptosis and differentiation caused by DNR was significant decreased, and most of HL-60 cells were initial. Western blot showed that the cleavage activity of Caspase-3 of HL-60 in AML-MSCs and normal MSCs co-cultured group was decreased, compared with HL-60 in single cultured group, moreover, the decrease was significantly in AML-MSC group. Additionally, the expression of survivin in AML-MSCs and normal MSCs co-cultured group was increased, compared with that in single cultured group, and increase was significant in AML-MSCs group. CONCLUSION MSCs can suppress Daunorubicin-induced HL-60 apoptosis via inhibiting Caspase-3 and maintaining survivin level.
Apoptosis ; Bone Marrow Cells ; Caspase 3 ; Cell Proliferation ; Daunorubicin ; HL-60 Cells ; Humans ; Leukemia, Myeloid, Acute ; Mesenchymal Stem Cells ; Survivin

OBJECTIVE: To study the influence of acute myeloid leukemia (AML) microenvironment on mesenchymal stem cells (MSCs). METHODS: MSCs were isolated from the bone marrow of newly diagnosed AML patients (AML-MSCs) and were cultured. The morphology of MSC was observed by inverted microscopy, the immunophenotypes of MSC were detected by flow cytometry, the proliferation ability of MSC was detected by using MTT method, the multi-differentation ability of MSC was assayed by osteogenic, lipogenic and chrondrogenic induction. The morphologic features, immunophenotypic characteristics, cell proliferation, and multipotential differentiation capability were compared between the MSC derived from normal healthy donors and AML patients. RESULTS: AML-MSCs presented the morphological features similar to the normal MSCs. In addition, AML-MSCs highly expressed CD29, CD44, CD73, CD105 and HLA-ABC. Meanwhile, they were homogenously negative for CD14，CD31, CD34, CD45, CD80, CD86 and HLA-DR. Further-more, AML-MSCs showed cell proliferation ability similar to normal MSCs. Notably, AML-MSCs exerted increased osteogenic-differentiation capacity as compared with normal MSCs. CONCLUSION AML-MSCs possess typical MSC phenotypes but displayed enhanced osteogenic-differentiation capacity.
Bone Marrow Cells ; Cell Differentiation ; Cells, Cultured ; Humans ; Leukemia, Myeloid, Acute ; Mesenchymal Stem Cells ; Osteogenesis ; Tumor Microenvironment

OBJECTIVE: To explore the role of bone marrow microenvironment(niche) in the development of acute myeloid leukemia (AML) and the effect of AML patients-derived MSC on the proliferation, cell cycle and immuno-phenotypes of HL-60 cells. METHODS: The MSC derived from bone marrow of patients with newly diagnosed AML were isolated and co-cultured with HL-60 cells. The effect of MSC on proliferation of HL-60 cells was detected by using 3H-TdR incorporation method, the cell cycle and immunophenotypes of HL-60 cells were detected by flow cytometry. RESULTS: The results of 3H-TdR incorporation assay showed that both AML-MSCs and normal MSCs remarkably suppressed the HL-60 cell proliferation in a time- and dose-dependent manner. The results of cell cycle analysis demonstrated that AML MSCs and normal MSCs induced arrest of the HL-60 cells in G/G phase. The results of immunophenotyping revealed that MSCs suppressed the expression of CD11a and CD154 on the surface of HL-60 cells. Moreover, AML MSCs exhibited increased inhibitory effects than that of normal MSCs. However, no remarkable effect of MSCs on CD54 expressions of HL-60 cells was observed in the current study. CONCLUSION AML-MSCs possess effects on HL-60 cell proliferation, cell cycle and immunophenotypes similiar to normal MSCs, but exhibited increased suppressive capacity on the expression of CD11a and CD154.
Bone Marrow Cells ; Cell Cycle ; Cell Proliferation ; HL-60 Cells ; Humans ; Immunophenotyping ; Leukemia, Myeloid, Acute ; Mesenchymal Stem Cells ; Tumor Microenvironment