Objective To develop a sensitive liquid chromatography-tandem mass spectrometric (LC-MS/MS) method for the determination of forsklin in rat plasma.Methods After extraction with methyl tert-butyl ether,chromatographic separation was performed on a C18 column with the mobile phase consisting of water ( 0.1％ formic acid)-acetonitrile in a gradient elution mode.A tandem mass spectrometer equipped with electrospray ionization (ESI) source was used as detector in the positive ion mode.Quantification was performed using multiple reaction monitoring (MRM) with the precursor product combination ions of m/z 411→375.3 and 285→193 for forsklin and diazepam.Results Good linearity was obtained in the 0.5-1000 ng/ml range for the analyte and the analytical method was validated in terms of specificity,precision,accuracy,recovery,stability and matrix effect.These assays gave RSD values always lower than 14.4％ and RE values between -3.5 ％ and 3.8％.In addition,the specificity,extraction recovery,stability and matrix effect were satisfactory.Conclusion Due to its high sensitivity,specificity and simplicity,the method could be used for pharmacokinetic studies of forsklin.

ABSTRACT:In recent years ,there has been high prevalence of murine typhus in Yunnan Province ,People's Republic of China .A large outbreak of murine typhus occurred in Xishuangbanna Prefecture ,Yunnan Province in 2010 .However ,not all cases were confirmed by laboratory assays ;therefore ,field epidemiologic and laboratory investigations of murine typhus in Xishuangbanna Prefecture were conducted in 2011 .Blood samples were collected from clinical diagnostic cases at the acute and convalescence stages of murine typhus in Xishuangbanna Prefecture ,Yunnan Province ,from June to September of 2011 ,and blood and spleen samples were collected from mice sharing the same habitats as the patients .Immunofluorescence assays were used to test for the presence of IgM and IgG antibodies against Rickettsia typhi in sera from patients and mice .Real‐time PCR was used to detect the groEL gene of R .typhi in blood clots from patients at the acute stage and in spleen tissue from mice .A total of 1 157 clinically diagnosed murine typhus cases occurred in Xishuangbanna Prefecture ,Yunnan Province in 2011 ,with an incidence of 102 .10/100 000 .Of these cases ,80 were investigated by laboratory assays and 74 of 80 patients were confirmed to have murine typhus .The coincidence rate between the clinical diagnosis and laboratory detection was 92 .50% .The positivi‐ty rate for IgG antibodies against R .typhi was 14 .0% (14/100) for Rattus f lavipectus ,while the rate by PCR was 9 .0%(9/100) .That laboratory diagnoses confirmed that the severity of the murine typhus outbreak in Xishuangbanna cannot be ig‐nored .The distribution of host animals transmitting R .typhi underscores this conclusion .

Objective To investigate the expression of HOXB4 gene in patients with myelodysplastic syn-dromes(MDS)and its clinical significance in disease progression.Methods mRNA expression of HOXB4 gene in bone marrow mononuclear cells was detected by real-time fluorescence quantitative PCR(RT-qPCR),and the difference in HOXB4 expression was compared between 49 patients with MDS(MDS group)and 35 patients without MDS(group C).The relationship of mRNA expression of HOXB4 with disease characteristics and clinical prognosis was explored in MDS patients.Results mRNA expression level of HOXB4 gene was higher in MDS group than that in group C(P＜0.05).The patients were divided into a high-and a low-expression group according to the median expression level of HOXB4.Leukocyte count was lower in the high-expression group in the low-expression group at the time of initial diagnosis.The proportion of patients with subtypes of primitive cellular hyperplasia,poor prognostic staging and leukemic transformation was higher in the high-expression group than in the low-expression group.Conclusions mRNA expression level of HOXB4 gene has certain relation with AML transformation in MDS patients.

Objective:To discuss the inhibitory effect of Schisandrin B on the proliferation of pancreatic cancer Pan02 cells,and to clarify the mechanism.Methods:CCK-8 method was used to detect the proliferation rates of the Pan02 cells after treated with different concentrations(0,0.78,1.56,3.12,6.25,12.50,and 25.00 mg·L-1)of Schisandrin B to select the optimal concentration and treatment time of Schisandrin B.The mouse pancreatic cancer Pan02 cells were divided into control group(0 mg·L-1 Schisandrin B),2.5 mg·L-1 Schisandrin B group,5.0 mg·L-1 Schisandrin B group,and 10.0 mg·L-1 Schisandrin B group.The morpholoy of Pan02 cells invarious groups was observed with light microscope;5-ethynyl-2'-deoxyuridine(EdU)staining assay was used to detect the positive expression rates of the Pan02 cells in various groups;flow cytometry was used to detect the percentages of the Pan02 cells at different cell cycles and the apoptotic rates of the cells in various groups;Western blotting method was used to detect the expression levels of cell cycle and apoptosis-related proteins in the cells in various groups.Results:The CCK-8 method results showed that after treated with Schisandrin B for 48 and 72 h,compared with 0 mg·L-1 Schisandrin B,the proliferation rates of the Pan02 cells after treated with different concentrations of Schisandrin B were decreased(P<0.01),especially at 72 h.0.25,5.0,and 10.0 mg·L-1 Schisandrin B were selected to treat the Pan02 cells,and 72 h was the treatment time.In control group,the Pan02 cells had a spindle shape,with good condition,and grew closely adhered to the wall with normal organelles and cytoplasm,in 2.5 and 5.0 mg·L-1 Schisandrin B groups,the cell volume was decreased,the intercellular adhesion was disappeared,and the cell membrane was intact but more permeable;the cytoplasm shrank and vacuolar structures appeared inside the cells,with some fragmented and floating on the surface of the solution;in 10.0 mg·L-1 Schisandrin B group,the Pan02 cells exhibited notable apoptotic bodies,indicating an apoptotic state.The EdU staining results showed that compared with control group,the rates of EdU positive cells in 2.5,5.0,and 10.0 mg·L-1 Schisandrin B groups were significantly decreased(P<0.01).The flow cytometry results showed that compared with control group,the percentages of the cells at S phase in 2.5,5.0,and 10.0 mg·L-1 Schisandrin B groups were significantly increased(P<0.01),while the percentages of the cells at G2/M phase were significantly decreased(P<0.01),and the percentages of the cells at G0/G1 phase in 5.0 amd 1.0 mg·L-1 Schisandrin groups were decreased(P<0.01);compared with control group,the apoptotic rates of the cells in 2.5,5.0,and 10.0 mg·L-1 Schisandrin B groups were significantly increased(P<0.01).The Western blotting results showed that compared with control group,the expression levels of p27,B-cell lymphoma 2(Bcl-2)associated X protein(Bax),cleaved cysteine aspartic acid protease-3(cleaved Caspase-3),and cleaved poly adenosine diphosphate(ADP)ribose polymerase(cleaved PARP)proteins in the cells in 2.5 mg·L-1 Schisandrin B group were significantly increased(P<0.05 or P<0.01),the expression levels of cyclin A2,cyclin E2,and Bcl-2 proteins in the cells in 5.0 and 10.0 mg·L-1 Schisandrin B groups were significantly decreased(P<0.05 or P<0.01),while the expression levels of p27,Bax,cleaved Caspase-3,and cleaved PARP proteins in the cells in 5.0 and 10.0 mg·L-1 Schisandrin B groups were significantly increased(P<0.01).Conclusion:Schisandrin B has an inhibitory effect on proliferation of the pancreatic cancer Pan02 cells,and its mechanism may be related to the activation of the cysteine aspartic acid protease-3(Caspase-3)pathway to induce the apoptosis and activating p27 protein to induce the arrest of cell cycle at S phase.

Objective:To discuss the effect of D-limonene on the proliferation and apoptosis of the glioblastoma(GBM)cells,and to clarify its possible mechanism.Methods:The GBM cells were divided into control group(0 mmol·L-1 D-limonene)and 0.2,0.4,0.6,0.8,and 1.0 mmol·L-1 D-limonene groups.CCK-8 method was used to detect the inhibitory rates of proliferation of the cells in various groups;clone formation assay was used to detect the clone formation rates of the cells in various groups;Annexin Ⅴ-FITC/PI method was used to detect the apoptotic rates of the cells in various groups;Western blotting method was used to detect the expression levels of protein kinase B(AKT),B-cell lymphoma-2(Bcl-2),Bcl-2-associated X protein(Bax),and poly adenosine diphosphate(ADP)-ribose polymerase(PARP)proteins in the cells in various groups;imunofluorescence method was used to detect the expression levels of cleaved Caspase-3 protein in the cells in various groups.Fifteen model mice with subcutaneous tumor xenografts were randomly divided into blank group(0 mg·kg-1·d-1 D-limonene),low dose of D-limonene group(200 mg·kg-1·d-1 D-limonene),and high dose of D-limonene group(400 mg·kg-1·d-1 D-limonene),and there were 5 mice in each group.The inhibitory rates of the tumor in vitro in various groups were calculated;HE staining and immunohistochemical staining were used to observe the morphology of subcutaneous tumor tissue of the mice in various groups and the growth curves of the tumor were drawn;immunohistochemical assay was used to detect the positive expression rates of Ki67 protein in subcutaneous tumor tissue of the mice in various groups;TUNEL staining was used to detect the apoptosis of the tumor cells in various groups.Results:In control group,the cells were spindle-shaped,in good condition,growing closely and adherently,with normal organelles and cytoplasm.After treated for 48 h,the cells in 0.6 mmol·L-1 D-limonene group showed reduced volume,intact but more permeable cell membranes,shrunken cytoplasm,internal vacuole structures,and some fragments floating in the solution.The cells in 0.8 and 1.0 mmol·L-1 D-limonene groups exhibited significant apoptotic bodies and were in an apoptotic state.The CCK-8 results showed that compared with control group,the inhibitory rates of proliferation of the U87,LN229,and GL261 cells in 0.6,0.8,and 1.0 mmol·L-1 D-limonene groups were significantly increased(P<0.01),the inhibitory rates of proliferation of the U87 and GL261 cells were significantly increased(P<0.01).The clone formation assay results showed that compared with control group,the clone formation rates of the U87,LN229,and GL261 cells in 0.4,0.6,and 0.8 mmol·L-1 D-limonene groups were significantly decreased(P<0.05 or P<0.01).The AnnexinⅤ-FITC/PI results showed that compared with control group,after treated with D-limonene for 48 h,the apoptotic rates of the LN229 cells in 0.6,0.8,and 1.0 mmol·L-1 D-limonene groups were significantly increased(P<0.01).The Western blotting results showed that compared with control group,the expression levels of Bax proteins in the LN229 cells in 0.6,0.8,and 1.0 mmol·L-1 D-limonene groups were significantly increased(P<0.01),while the expression levels of AKT and Bcl-2 proteins were significantly decreased(P<0.01),the expression level of PARP protein in the LN229 cells in 0.8 and 1.0 mmol·L-1 D-limonene group was significanthy increased(P<0.01).The immunofluorescence results showed that compared with control group,the expression levels of cleaved Caspase-3 protein in the LN229 cells in 0.6,0.8,and 1.0 mmol·L-1 D-limonene groups were significantly increased(P<0.01).Compared with blank group,the tumor volumes of the mice in low and high doses of D-limonene groups were significantly decreased(P<0.01).Compared with blank group,the tumor weights of the mice in low and high doses of D-limonene groups were significantly decreased(P<0.05),and the inhitory rates of tumor were significantly increased(P<0.05).The tumor cells in blank group were diffusely distributed,with deepened nuclear staining and increased nucleocytoplasmic ratio;a large number of degenerated and necrotic tumor cells were observed in tumor tissue of the mice in low and high doses of D-limonene groups.Compared with blank group,the positive expression rates of Ki67 protein in tumor tissue of the mice in low and high doses of D-limonene groups were significantly decreased(P<0.01).Compared with blank group,the apoptotic rates of tumor cells of the mice in low and high doses of D-limonene groups were significantly increased(P<0.01).Conclusion:D-limonene has the inhibitory effect on the proliferation of the GBM cells;its mechanism may be related to the regulation of AKT protein expression and the activation of the Caspase-3 pathway to induce the apoptosis.