Assessment of blended biochemistry classes based on massive open online courses and a "semi-flipped" learning environment.

Flipped classroom based on active learning is becoming an increasingly popular pedagogical method in higher education capable of increasing student performance in higher-order learning outcomes including application, analysis, evaluation, and creation. However, the success of a flipped classroom model relies on various supporting elements such as the accessibility of technology, and it may not be appropriate for all students and courses. In this study, a new blended biochemistry classroom model based on massive open online courses and a "semi-flipped" environment was applied to the students enrolled in three majors (stomatology, pharmacy, and preventive medicine) at Cheeloo College of Medicine, Shandong University, China. To assess the improvement of the students' perception of self-cognition in the blended biochemistry classes, surveys were conducted before and after undertaking the biochemistry course. Survey responses and total (final) score for the biochemistry course were analyzed using appropriate statistical methods. Compared to students who received traditional classroom instruction, students who participated in the blended classroom model achieved higher academic performance (p < 0.01) and reported a significant improvement in their perception of self-cognition (p < 0.01, or p < 0.05). More than 80% of participants preferred the blended classroom model to that of traditional classroom instruction.

How Do Blended Biochemistry Classes Influence Students' Academic Performance and Perceptions of Self-Cognition?

The flipped classroom is becoming a popular new instructional model in higher education capable of increasing student performance in higher-order learning outcomes. However, the success of a flipped classroom model depends on various supporting elements, and it may not be appropriate for all students and courses. In this study, a new blended Biochemistry classroom model based on Massive Open Online Courses (MOOC) and a "semi-flipped" environment was applied to Biochemistry instruction of Nursing and Clinical Medicine majors. The students' academic performance and perceptions of self-cognition were used to assess the blended Biochemistry classroom. Students who participated in the blended classroom model achieved higher academic performance (p < 0.01) and reported a significant improvement in their perceptions of self-cognition (p < 0.05) compared to the control group. Moreover, the effectiveness of the blended Biochemistry classroom on the small size class (Nursing major) was stronger than on the large size class (Clinical Medicine major).

Roles of conserved residues in the receptor binding sites of human parainfluenza virus type 3 HN protein.

Human parainfluenza virus type 3 (hPIV-3) entry and intrahost spread through membrane fusion are initiated by two envelope glycoproteins, hemagglutinin-neuraminidase (HN) and fusion (F) protein. Binding of HN protein to the cellular receptor via its receptor-binding sites triggers conformational changes in the F protein leading to virus-cell fusion. However, little is known about the roles of individual amino acids that comprise the receptor-binding sites in the fusion process. Here, residues R192, D216, E409, R424, R502, Y530 and E549 located within the receptor-binding site Ⅰ, and residues N551 and H552 at the putative site Ⅱ were replaced by alanine with site-directed mutagenesis. All mutants except N551A displayed statistically lower hemadsorption activities ranging from 16.4% to 80.2% of the wild-type (wt) level. With standardization of the number of bound erythrocytes, similarly, other than N551A, all mutants showed reduced fusogenic activity at three successive stages: lipid mixing (hemifusion), content mixing (full fusion) and syncytium development. Kinetic measurements of the hemifusion process showed that the initial hemifusion extent for R192A, D216A, E409A, R424A, R502A, Y530A, E549A and H552A was decreased to 69.9%, 80.6%, 71.3%, 67.3%, 50.6%, 87.4%, 84.9% and 25.1%, respectively, relative to the wt, while the initial rate of hemifusion for the E409A, R424A, R502A and H552A mutants was reduced to 69.0%, 35.4%, 62.3%, 37.0%, respectively. In addition, four mutants with reduced initial hemifusion rates also showed decreased percentages of F protein cleavage from 43.4% to 56.3% of the wt. Taken together, Mutants R192A, D216A, E409A, R424A, R502A, Y530A, E549A and H552A may lead to damage on the fusion activity at initial stage of hemifusion, of which decreased extent and rate may be associated with impaired receptor binding activity resulting in the increased activation barrier of F protein and the cleavage of it, respectively.

Association of KIR Genotypes and Haplotypes in HBeAg-positive Chronic Hepatitis B Patients Treated with Entecavir.

BACKGROUND: A large proportion of patients with chronic hepatitis B (CHB) in China do not respond to entecavir (ETV) treatment. It remains unclear whether the Killer immunoglobulin-like receptor (KIR) genotypes and haplotypes were associated with the advantage of seroconversion in phepatitis B e-Antigen (HBeAg) positive CHB patients treated with ETV. METHODS: Polymerase chain reaction with sequence-specific primers (PCR-SSP) was used to analyze KIR genes in a Chinese Han population of 198 ETV-treated HBeAg-positive CHB patients and 200 healthy controls. Of the 198 patients, 59 were complete response group (CRG) and 139 were null or partial response group (NPRG) to the treatment with ETV. RESULTS: The frequencies of KIR genotype M, and haplotype 8 were significantly higher(P = 0.017, OR = 2.497，95%CI = 5.39-1.16 and P = 0.034, OR = 1.905，95%CI = 3.48-1.04, respectively), while the frequencies of genotype AH and haplotype 5 were significantly lower (P = 0.039, OR = 0.504, 95%CI = 0.97-0.26 and P = 0.031, OR = 0.601, 95%CI = 0.96-0.38, respectively) in HBeAg-positive CHB patient group than those in healthy group. Of note, the frequencies of KIR genotype AF and haplotype 1 were significantly higher (P = 0.022, OR = 2.860, 95%CI = 7.24-1.13 and P = 0.001, OR = 3.261, 95%CI = 6.47-1.64, respectively), while the frequencies of genotype AH and haplotype 5 were significantly lower (P = 0.038, OR = 0.338, 95%CI = 0.98-0.12 and P = 0.004, OR = 0.354, 95%CI = 0.73-0.17, respectively) in NPRG than those in CRG. CONCLUSIONS: The patients with KIR genotype AF and haplotype 1 might be negative, while genotype AH and haplotype 5 might be of advantage to the therapy with ETV, which are useful for improving novel personalized precise therapy strategy in HBeAg-positive CHB patients.

Association between KIR Genes and Efficacy of Treatment of HBeAg-Positive Chronic Hepatitis B Patients with Entecavir.

Entecavir (ETV) is commonly used to treat chronic hepatitis B (CHB) in China. However, certain percentages of e-Antigen (HBeAg) positive CHB patients do not respond to ETV therapy. OBJECTIVE: To investigate whether the killer immunoglobulin-like receptor (KIR) genes were associated with seroconversion in HBeAg positive CHB responder patients treated with ETV. METHODS: Polymerase chain reaction with sequence-specific primers (PCR-SSP) method was performed to genotype KIR genes in 200 healthy controls and 198 HBeAg-positive CHB patients which 59 were defined as the complete response group (CRG) to the treatment with ETV and 139 were defined as null or partial response group (NPRG). RESULTS: The frequencies of KIR2DS2 and KIR2DS3 were significantly higher (P=0.030, OR=1.57，95%CI=2.36-1.05 and P=0.018, OR=1.773，95%CI=2.77-1.13, respectively), while, the frequencies of KIR2DL3, KIR2DS1 and KIR3DS1 were significantly lower (P=0.038, OR=0.525, 95%CI=0.96-0.29,and P=0.031, OR=0.640, 95%CI =0.95-0.43, and P=0.035, OR=0.641, 95%CI=0.96-0.43, respectively) in HBeAg-positive CHB patients than those in healthy controls. The frequency of KIR2DS3 gene was significantly higher in NPRG than that in CRG (P=0.018, OR=0.402, 95%CI=0.83-0.20). The frequencies of KIR2DL3 and KIR3DS1 genes were significantly higher in CRG than those in NPRG (P=0.019, OR=3.625, 95%CI=10.83-1.21 and P=0.041, OR=1.949, 95%CI=3.65-1.04, respectively). CONCLUSION: Patients with KIR2DS3 might have negative responses to anti-HBV therapy with ETV and patients with KIR2DL3 and KIR3DS1 might have advantage in the therapy with ETV.

Downregulation of reticulocalbin-1 differentially facilitates apoptosis and necroptosis in human prostate cancer cells.

Reticulocalbin 1 (RCN1), an endoplasmic reticulum (ER)-resident Ca2+ -binding protein, is dysregulated in cancers, but its pathophysiological roles are largely unclear. Here, we demonstrate that RCN1 is overexpressed in clinical prostate cancer (PCa) samples, associated with cyclin B, not cyclin D1 expression, compared to that of benign tissues in a Chinese Han population. Downregulation of endogenous RCN1 significantly suppresses PCa cell viability and arrests the cell cycles of DU145 and LNCaP cells at the S and G2/M phases, respectively. RCN1 depletion causes ER stress, which is evidenced by induction of GRP78, activation of PERK and phosphorylation of eIF2α in PCa cells. Remarkably, RCN1 loss triggers DU145 cell apoptosis in a caspase-dependent manner but mainly causes necroptosis in LNCaP cells. An animal-based analysis confirms that RCN1 depletion suppresses cell proliferation and promotes cell death. Further investigations reveal that RCN1 depletion leads to elevation of phosphatase and tensin homolog (PTEN) and inactivation of AKT in DU145 cells. Silencing of PTEN partially restores apoptotic cells upon RCN1 loss. In LNCaP cells, predominant activation of CaMKII is important for necroptosis in response to RCN1 depletion. Thus, RCN1 may promote cell survival and serve as a useful target for cancer therapy.

Oxidative stress induced autophagy in cancer associated fibroblast enhances proliferation and metabolism of colorectal cancer cells.

Tumors are comprised of malignant cancer cells and stromal cells which constitute the tumor microenvironment (TME). Previous studies have shown that cancer associated fibroblast (CAF) in TME is an important promoter of tumor initiation and progression. However, the underlying molecular mechanisms by which CAFs influence the growth of colorectal cancer cells (CRCs) have not been clearly elucidated. In this study, by using a non-contact co-culture system between human colorectal fibroblasts (CCD-18-co) and CRCs (LoVo, SW480, and SW620), we found that fibroblasts existing in tumor microenvironment positively influenced the metabolism of colorectal cancer cells, through its autophagy and oxidative stress pathway which were initially induced by neighboring tumor cells. Therefore, our data provided a novel possibility to develop fibroblasts as a potential target to treat CRC.

Identification of a benzo imidazole thiazole derivative as the specific irreversible inhibitor of protein tyrosine phosphatase.

Protein tyrosine phosphatases (PTPs) play key roles in many physiological processes, including cell proliferation, differentiation, immune responses and neural activities. Inappropriate regulation of the PTP activity could lead to human diseases, such as cancer or diabetes. Functional studies of PTP can be greatly facilitated by chemical probes that covalently label the active site of a PTP through an activity-dependent chemical reaction. Here, we characterize compound E4 as a new class of PTP activity probes. Compound E4 inactivate STEP in a time- and concentration-dependent fashion. Further study showed that compound E4 inhibits a series of PTPs in a time dependent manner, whereas it shows little or no inhibition toward metal dependent protein phosphatases. Collectively, this new identified covalent inhibitor of PTPs has the potential to be developed to an active site Cys directed PTP probes to study the active properties of the PTPs in cell signaling.

Mutations in the Leucine Zipper-Like Motif of the Human Parainfluenza Virus 3 Fusion Protein Impair Fusion Activity.

OBJECTIVE: To investigate the effect of the leucine zipper-like motif between HRA and HRB of the human parainfluenza virus 3 fusion protein on fusion activity. METHODS: Site-directed mutagenesis was utilized to substitute the heptadic residues at 257, 264, 271, 278, 285, 292, and 299 in this motif with alanine. Additionally, 3 middle heptadic leucine residues at 271, 278, and 285 were replaced with alanine singly or in combination. A vaccinia virus-T7 RNA polymerase transient expression system was employed to express the wild-type or mutated fusion (F) proteins. Three different types of membrane fusion assays were performed to analyze the fusogenic activity, fluorescence-activated cell sorting (FACS) analysis was executed to examine the cell surface expression level, and a coimmunoprecipitation assay was conducted to probe the hemagglutinin-neuraminidase (HN)-F interaction at the cell surface. RESULTS: All of the substitutions in this motif exhibited diminished or even lost fusion activity in all stages of fusion, although they all had no effect on cell surface expression. In the coimmunoprecipitation assay, all mutants resulted in decreased detection of the HN-F complexes compared with that of the wild-type F protein. CONCLUSIONS: This motif has an important influence on fusion activity, and its integrality is indispensable for membrane fusion.

Metformin prevents DMH-induced colorectal cancer in diabetic rats by reversing the warburg effect.

Epidemiologic studies have shown that the treatment of diabetics with metformin reduced the risk of cancer-related mortality. Here, we investigated the chemopreventive effects of metformin on dimethylhydrazine (DMH)-induced colorectal carcinogenesis in diabetic SD rats following metformin treatment and the effect on Warburg effect involved in this process. Diabetic rat models were induced with high-fat feeding in combination with a low dose of Streptozotocin (STZ) and then induce colorectal cancer with a low dose of DMH. The formation of colorectal Aberrant crypt foci (ACF) and the incidence, number and size of the tumor were measured. The proliferation indices of colonic tissues were determined through Proliferating cell nuclear antigen (PCNA) immunostaining. Then detect the expression of PK and IDH in colonic tissues using immunohistochemistry and Western blot. The enzyme activities of HK and PDH in colonic tissues were measured. The growth and expression of PK and IDH and activity of HK and PDH in cell lines LoVo and HT-29 were measured after metformin treatment. The results showed that metformin treatment significantly inhibited the formation of ACF and tumors. The proliferation index of colonic tissues was significantly decreased following metformin treatment. In addition, metformin inhibited cell growth and decreased the imbalance in the expression of the enzymes involved in glycolysis and the TCA cycle. These findings suggested that metformin might produce a synergistic colon cancer-preventative effect in diabetic patients through the regulation of the enzymes expression involved in glucose metabolism.

Mutations in the DI-DII Linker of Human Parainfluenza Virus Type 3 Fusion Protein Result in Diminished Fusion Activity.

Human parainfluenza virus type 3 (HPIV3) can cause severe respiratory tract diseases in infants and young children, but no licensed vaccines or antiviral agents are currently available for treatment. Fusing the viral and target cell membranes is a prerequisite for its entry into host cells and is directly mediated by the fusion (F) protein. Although several domains of F are known to have important effects on regulating the membrane fusion activity, the roles of the DI-DII linker (residues 369-374) of the HPIV3 F protein in the fusogenicity still remains ill-defined. To facilitate our understanding of the role of this domain might play in F-induced cell-cell fusion, nine single mutations were engineered into this domain by site-directed mutagenesis. A vaccinia virus-T7 RNA polymerase transient expression system was employed to express the wild-type or mutated F proteins. These mutants were analyzed for membrane fusion activity, cell surface expression, and interaction between F and HN protein. Each of the mutated F proteins in this domain has a cell surface expression level similar to that of wild-type F. All of them resulted in a significant reduction in fusogenic activity in all steps of membrane fusion. Furthermore, all these fusion-deficient mutants reduced the amount of the HN-F complexes at the cell surface. Together, the results of our work suggest that this region has an important effect on the fusogenic activity of F.

Roles of the highly conserved amino acids in the globular head and stalk region of the Newcastle disease virus HN protein in the membrane fusion process.

Newcastle disease virus (NDV), an avain paramyxovirus, has been assigned to the genus Avulavirus within the family Paramyxoviridae. It causes Newcastle disease (ND) that is a highly contagious and fatal viral disease affecting poultry and most species of birds. The hemagglutinin-neuraminidase (HN) protein of NDV has multiple functions including mediating hemadsorption (HAD), neuraminidase (NA), and fusion promotion activities affecting the process of viral attachment, entry, replication and dissemination. Fusion ability of the NDV was highly correlated to its virulence. Mutations in the HN globular head and headless HN of NDV were constructed to determinate the impact of highly conserved amino acids in the globular head of paramyxovirus HN proteins and the roles of the stalk region of HN in the fusion process. It was found that the interaction between F and HN mutants E401A, G402A, G468A, V469A, Y526A, and T527A was equal to that in F and wt HN. The mutations of G402A, G468A, V469A, and T527A had various effects on cell fusion promotion, receptor binding ability, and NA activity, but the membrane merging rate was comparable to wt HN. The elimination of hemadsorption ability and NA activity of E401A and Y526A resulted in the loss of the fusion promotion function of HN. The conclusion was that receptor binding and NA had a common active site and E401 and Y526 amino acids were essential for virus attachment, entry, and dissemination. In addition, G468A mutation made different contributions to HAD and NA, which indicated that G468 was one of the potential key amino acids in switching the two functions between receptor binding and sialic acid destruction of HN. It was also proven that the headless HN of NDV could promote the fusion event mediated by F. Thus, it revealed a novel mechanism in F activation of NDV.

In vitro properties of apheresis platelet during extended storage in plasma treated with anandamide.

BACKGROUND: In China apheresis platelets (PLTs) are stored in plasma for only 5 days, resulting in PLT inventory pressures. Anandamide (ANA) was reported to be a potential agent to inhibit PLT apoptosis. The aim of this study was to evaluate the characteristics of extended storage PLTs in plasma treated with ANA in vitro. METHODS: Apheresis PLTs (n = 20) were prepared in plasma treated with ANA, and stored at 22 °C for up to 11 days. On day 1, 3, 5, 7, 9 and 11, PLTs were tested for PLT count, mean PLT volume (MPV), PLT distribution width (PDW), pH, pCO(2), pO(2), hypotonic shock response (HSR), phosphatidylserine (PS) exposure and soluble P-selectin content. RESULTS: PLTs stored in plasma with/without ANA didn't show significant differences during the first 5 days of storage. From the 7(th) day on, PLTs stored in plasma with ANA displayed significantly lower PS expression, soluble P-selectin content and higher HSR scores than those stored in plasma without ANA (P <0.05), respectively. CONCLUSION: The extended storage of PLTs in plasma treated with 0.5 µmol/l ANA showed better characteristics of the PLTs, compared with the control group, which was suggested to potentially alleviate the PLT storage lesion.

Acidic amino acids increase fusion activity in the specific fusion domain of Newcastle disease virus fusion protein.

To explore the effects of amino acids Gln and Asn within the specific fusion domain of fusion (F) protein on the specific membrane fusion in Newcastle disease virus (NDV), the mutants Q204E-Q205E and N245D were constructed in the specific fusion domain of F protein. The mutant genes were co-expressed with homologous or heterologous hemagglutinin-neuraminidase (HN) in BHK21 cells. Cell fusion functions of mutants were analyzed with Giemsa staining and reporter gene methods. Cell surface expression efficiency was analyzed with immunofluorescence assay and fluorescence-activated cell sorter analysis. Co-immunoprecipitation was performed to analyze the interaction of mutant F proteins with the homotypic HN protein. Both Q204E-Q205E and N245D mutations caused increased cell-cell fusion activity when they were co-expressed with homotypic HN protein. The mutant F proteins had slight changes in cell surface expression compared with that of wild-type F protein. The interactions of Q204E-Q205E or N245D with their homotypic HN increased significantly (P < 0.01) compared with the wild-type F protein. Neither Q204-Q205E nor N245D caused cell fusion in the presence of heterologous HN protein. Our data suggested that the residues Q204, Q205, and N245 play a critical role in the regulation of cell fusion. They may decrease the interaction of wild-type NDV F and NDV HN to suppress the fusion activity for survival of the infected host, which may enable a persistent virus infection and long-term virus reproduction and spread.

Role of N-linked glycosylation of the human parainfluenza virus type 3 hemagglutinin-neuraminidase protein.

Human parainfluenza virus type 3 (hPIV-3) is a major respiratory tract pathogen that affects infants and young children. The hPIV-3 hemagglutinin-neuraminidase (HN) protein is a multifunctional protein mediating hemadsorption (HAD), neuraminidase (NA), and fusion promotion activities, each of which affects the ability of HN to promote viral fusion and entry. The hPIV-3 HN protein contains four potential sites (N308, N351, N485 and N523) for N-linked glycosylation. Electrophoretic mobility analysis of mutated HN proteins indicated that N308, N351 and N523 sites, but not the N485 site in HN protein, were targeted for the addition of glycans in BHK-21 cells. These functional glycosylation sites were systematically eliminated in various combinations from HN to form a panel of mutants in which the roles of individual carbohydrate chains and groups of carbohydrate chains could be analyzed. Removal of individual or multiple N-glycans on the hPIV-3 HN protein had no effects on transport to the cell surface, expression and NA activity. Single glycosylation site mutants (G1, G2 and G4) not only impaired fusion promotion activity but also reduced HAD activity of HN protein, which was even more obvious for all three double mutants (G12, G14 and G24) and the triple mutant (G124). In addition, every mutant protein retained F-interactive capability that was equal to the wild-type protein capability. Interestingly, the F protein that could be co-immunoprecipitated with the G12 mutated protein or immunoprecipitated with anti-F antibody was not efficiently cleaved. For G14, G24 and G124, little cleaved F protein was detected in co-immuoprecipitation F protein assay and its total amounts where in the cell lysates. The mechanism underlying hPIV-3 HN and F protein remained associated before and after receptor engagement and the strength of the HN-receptor interaction modulated the activation of F the protein which could determine the extent of fusion. Finally, we demonstrated that single or multiple N-glycosylation site mutations inhibited fusion at the earliest stages. Taken together, these results indicated that N-glycosylation of hPIV-3 HN is critical to its receptor recognition activity, cleavage of the F protein, and fusion promotion activity, but had no influence on its interaction with the homologous F protein and NA activity.

'a'-Position-mutated and G4-mutated hemagglutinin-neuraminidase proteins of Newcastle disease virus impair fusion and hemagglutinin-neuraminidase-fusion interaction by different mechanisms.

OBJECTIVES: To determine the effects of heptad repeat regions (HRs) and N-linked carbohydrate sites of the Newcastle disease virus hemagglutinin-neuraminidase (HN) protein on fusion of HN and fusion (F) proteins and HN-F interaction. METHODS: We mutated six 'a' residues in the HRs and four asparagines in N-linked carbohydrate sites to alanine in the HN protein. A vaccinia-T7 RNA polymerase expression system was used to express HN cDNAs in BHK-21 cells to determine the HN functions. Deglycosylation was treated with PGNase F digestion. The formation of HN-F protein complexes was determined by the coimmunoprecipitation assay. RESULTS: Each HR-mutated protein interfered with fusion and the HN-F interaction. The G4-mutated protein not only impaired fusion and HN-F interaction but also decreased activities in cell fusion promotion, hemadsorption and neuraminidase. CONCLUSIONS: It is assumed that two different mechanisms for mutations in these two regions are responsible for the decreased fusion promotion activity and the reduced ability of interaction with F protein. Mutations in the HRs impair fusion and HN-F interaction by altering the transmission of a signal from the globular domain to the F-specific region in the stalk, but the G4 mutation modulates fusion and HN-F interaction by the misfolding of some important structures.

[Study on functions of N-carbohydrate chains in human parainfluenza virus type 3 hemagglutinin-neuraminidase protein].

To determine the functions of N-carbohydrate chains in human parainfluenza virus type 3 hemagglutinin-neuraminidase(HN) protein, a PCR-based site-directed mutagenesis method was used to obtain N-glycan mutants. Protein electrophoresis rate, cell surface expression,receptor binding activity, neuraminidase activity and cell fusion promotion activity were determined. The HN proteins of single mutants (G1, G2, and G4) and multiple mutants (G12, G14, G24 and G124) migrated faster than the wild-type (wt) HN protein on polyacrylamide gels, while G3-mutated protein and wt HN protein migrated at the same position. There was no statistic difference in cell surface expression and neuraminidase activity between wt and each mutant HN protein (P>0.05), but receptor binding activity and cell fusion promotion activity of each mutant protein was reduced to significant extent (P<0.05). G1, G2 and G4 mutants exhibited re duced receptor binding activity, which was 83.94%, 76.45% and 55.32% of the wt level, respectively. G1, G2 and G4-mutated proteins also showed reductions in fusion promotion activity, which was 80.84%, 77.83% and 64.16%, respectively. Multiple mutants with G12-, G14-, G24- and G124- substitutions could further reduce receptor binding activities, 33.07%, 20.67%, 19.96% and 15.11% of the wt HN level, respectively. G12, G14, G24 and G124 mutants exhibited levels of fusion promotion activity that were only 46.360, 12.04%, 13.43% and 4.05% of the wt amount, respectively. As N-glycans of hPIV3 HN protein play an important role in receptor binding activity and cell fusion promotion activity of HN protein. We propose that the loss of N-glycans change the conformation or orientation of globular domain that is responsible for receptor binding and lower receptor binding activity and cell fusion promotion activi ty.

Human leukocyte antigen-C and killer cell immunoglobulin-like receptor gene polymorphisms among patients with syphilis in a Chinese Han population.

Syphilis is a sexually transmitted infection caused by the Treponema pallidum subspecies pallidum spirochete bacterium. The killer cell immunoglobulin-like receptors (KIR), interacting with human leukocyte antigens (HLA), regulate the activations of natural killer (NK) cells and certain T-cell subsets in response to microbe infection. The objective of this study was to explore whether KIR and HLA-C gene polymorphisms were associated with syphilis in a Chinese Han population. Polymerase chain reaction with sequence-specific primers (PCR-SSP) method was used to genotype KIR and HLA-C genes in 231 syphilis patients and 247 healthy controls. Framework genes KIR2DL4, KIR3DL2, KIR3DL3 and KIR3DP1 were present in all individuals. The frequencies of KIR2DS3 and KIR3DS1 were higher in syphilis patients than in healthy controls (p = 0.030 and p = 0.038, respectively), while the frequency of KIR2DS5 was higher in healthy controls than in syphilis patients (p = 0.015; OR = 0.575). The homozygote for HLA-C1 allele (HLA-C1C1) was more common in controls compared with syphilis patients (p = 0.030; OR = 0.667). The frequency of individuals with HLA-C1C1 and KIR2DL3 genotype was higher in control group relative to syphilis patient group (p = 0.018; OR = 0.647). These data indicated that KIR2DS3 and KIR3DS1 were more prevalent in syphilis patients than in controls, and that KIR2DS5, HLA-C1C1 and HLA-C1C1-KIR2DL3 were more prevalent in controls than in syphilis patients, respectively. These will require further investigation using functional studies.

Oridonin nanosuspension was more effective than free oridonin on G2/M cell cycle arrest and apoptosis in the human pancreatic cancer PANC-1 cell line.

Oridonin, a diterpenoid isolated from Rabdosia rubescencs, has been reported to have antitumor effects. However, low solubility has limited its clinical applications. Preparation of drugs in the form of nanosuspensions is an extensively utilized protocol. In this study, we investigated the anticancer activity of oridonin and oridonin nanosuspension on human pancreatic carcinoma PANC-1 cells. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was performed to investigate the effect of oridonin on cell growth. Propidium iodide and Hoechst 33342 staining were used to detect morphologic changes. The percentage of apoptosis and cell cycle progression was determined by flow cytometric method staining with propidium iodide. Annexin V-fluorescein isothiocyanate (FITC)/PI staining was used to evaluate cell apoptosis by flow cytometry. Caspase-3 activity was measured by spectrophotometry. The apoptotic and cell cycle protein expression were determined by Western blot analysis. Both oridonin and oridonin nanosuspension induced apoptosis and G(2)/M phase cell cycle arrest, and the latter had a more significant cytotoxic effect. The ratio of Bcl-2/Bax protein expression was decreased and caspase- 3 activity was stimulated. The expression of cyclin B1 and p-cdc2 (T161) was suppressed. Our results showed that oridonin nanosuspension was more effective than free oridonin on G(2)/M cell cycle arrest and apoptosis in the human pancreatic cancer PANC-1 cell line.

Preventive action of curcumin in experimental acute pancreatitis in mouse.

BACKGROUND & OBJECTIVES: Curcuma longa (turmeric) has a long history of use in Ayurvedic medicine as a treatment for inflammatory conditions. The purpose of the present study was to investigate the preventive effects of curcumin against acute pancreatitis (AP) induced by caerulein in mouse and to elucidate possible mechanism of curcumin action. METHODS: Curcumin (50 mg/kg/day) was intraperitoneally injected to Kun Ming male mice for 6 days, followed by injection of caerulein to induce AP. GW9662 (0.3 mg/kg), a specific peroxisome proliferator-activated receptor gamma (PPARγ) antagonist, was intravenously injected along with curcumin. Murine macrophage RAW264.7 cells were treated with 100 µmol/l curcumin for 2 h, and then stimulated with 0.1 µ g/ml lipopolysaccharide (LPS). Serum amylase and transaminase levels were measured at 10 h after AP. TNF-α level in mouse serum and cell culture medium were detected by ELISA. Expression of PPARγ and NF-κB were analyzed by RT-PCR and Western blot. RESULTS: Curcumin significantly decreased the pancreas injury and reversed the elevation of serum amylase, ALT and AST activities and TNF-α level in mice with AP. Curcumin treatment inhibited the elevation of NF-κB-p65 in the nucleus of mouse pancreas AP group and RAW264.7 cells, but significantly increased the expression of PPARγ. GW9662 could abolish the effects of curcumin on serum levels of amylase, ALT, AST, TNF-α, and NF-κB level. INTERPRETATION & CONCLUSIONS: Our results suggest that curcumin could attenuate pancreas tissue and other organ injury by inhibiting the release of inflammatory cytokine TNF-α. These effects may involve upregulation of PPARγ and subsequent downregulation of NF-κB.