[Active screening of intestinal carbapenem-resistant Enterobacteriaceae in high-risk patients admitted to the hematology wards and its effect evaluation].

Objective: To evaluate the effect of intestinal carbapenem-resistant Enterobacteriaceae (CRE) active screening combined with enhanced intervention in the prevention and control of nosocomial infection in patients admitted to the hematological ward. Methods: Patients who were admitted to the Department of Hematology in a tertiary-care general hospital from March 1, 2017 to December 31, 2019 and underwent chemotherapy or immunosuppressive therapy comprised the intervention group. They were screened for intestinal CRE at least thrice. From December 1, 2016 to February 28, 2017, patients who underwent chemotherapy or immunosuppressive therapy without active intestinal CRE screening in the Department of Hematology formed the control group. Both the patient groups were monitored for CRE infection in real time. The χ(2) test was used to compare the changes in the CRE infection rate and mortality in high-risk patients before and after the active screening. Results: During the intervention period, the CRE colonization rate of patients was 16.46% (66/401) ; in terms of disease distribution, the colonization rate of acute leukemia was the highest 23.03% (26/113) . Of the 66 colonized patients, 27 (40.9%) patients were identified as positive for CRE at the first screening, 15 (22.7%) were identified at the time of the second screening, and the remaining 24 (36.4%) were identified at the third or subsequent screening; Carbapenem-resistant Klebsiella pneumoniae (CRPK) strains were dominant among the pathogens, accounting for 54.55% (36/66) . During the active screening period, the CRE infection rate (2.49%) and mortality rate (50.00%) of high-risk patients were significantly lower than those of the controls (11.30% and 69.23%, respectively) . The pathogens of 10 CRE infection patients during the intervention period were exactly the same as the previous active screening pathogens, and the coincidence rate was 100%. Conclusion: The CRE colonization rate was the highest in patients with acute leukemia who were admitted in the hematology wards. CRPK is the main pathogen of CRE colonization, infection, and death. Increasing the frequency of screening can significantly raise the positive rate of screening, Active screening can effectively reduce the incidence and subsequent mortality of CRE in high-risk patients admitted in the hematological wards. High coincidence rate between CRE screening positive pathogens and subsequent CRE infection pathogens. Intestinal CRE screening can serve as an indicator of CRE bloodstream infection in patients with hematological diseases as well as provide information for antibiotics therapy.

[Anti-lung cancer effect of myeloid and plasmacytoid dendritic cell combined vaccines loaded with tumor cell lysates in vitro].

Objective: To investigate the feasibility of myeloid and plasmacytoid dendritic cell combined vaccines loaded with heat-treated Lewis lung cancer cell lysates for treatment of lung cancer in mice. Methods: Bone marrow cells were induced by the recombinant mouse fms-like tyrosine kinase receptor 3 ligand (rmFlt3-L) in vitro, myeloid dendritic cells (mDC) and plasmacytoid dendritic cells (pDC) were separated by magnetic beads. The mDC, pDC, and mDC∶pDC=1∶1 were stimulated with heat-treated Lewis lung cancer cell lysates, respectively. The effects of each group on stimulating of lymphocyte proliferation and inducing of T cell to kill tumor cells in vitro were compared. The alternations of the immunophenotypes of CD80, CD86, CD40 and major histocompatibility complex Ⅱ (MHC-Ⅱ) were detected by flow cytometry. The secretion of cytokines including interlukin-12 (IL-12), interlukin-6 (IL-6), and tumor necrosis factor α (TNF-α) were detected by enzyme-linked immunosorbent assay (ELISA). Results: The lymphocyte proliferation in mice stimulated with mDC+ pDC group loaded with heat-treated Lewis lung cancer cell lysates was 10.80±0.66, significantly higher than 8.63±0.65 of mDC group and 7.10±0.46 pDC group under the same culture conditions, respectively (P<0.05). When the ratio of effector cells: target cells (E∶T) was 10∶1, the killing rate of the mDC+ pDC group loaded with heat-treated tumor cell lysate was 31.68%±2.93%, significantly higher than 17.44%±0.97% of mDC group and 10.29%±1.33% of pDC group, respectively (P<0.05). When the ratio of E∶T was 20∶1, the killing rate of the mDC+ pDC group loaded with heat-treated tumor cell lysate was 54.77%±3.28%, significantly higher than 35.25%±1.51% of mDC group and 15.52%±0.73% of pDC group, respectively (P<0.05). When the ratio of E∶T was 40∶1, the killing rate of the mDC+ pDC group loaded with heat-treated tumor cell lysate was 73.01%±0.91%, significantly higher than 51.36%±0.58% of mDC group and 22.65%±1.28% of pDC group, respectively (P<0.05). With the rate of E∶T increased, the killing rate also increased. The mean fluorescence intensities of surface molecules including CD80, CD86, CD40 and MHC-Ⅱ of mDC: pDC=1 group pulsed with heat-treated Lewis lung cancer cell lysates were higher than those of mDC group and pDC group. The IL-6 cytokine concentrations of mDC+ pDC group, mDC group and pDC group loaded with heat-treated Lewis lung cancer cell lysates were (586.67±52.52) pg/ml, (323.33±67.14) pg/ml and (166.67±16.07) pg/ml, respectively. The concentrations of IL-12 in each group were (2 568.75±119.24) pg/ml, (2 156.25±120.55) pg/ml and (672.92±31.46) pg/ml, respectively. The concentrations of TNF-α in each group were (789.33±48.08) pg/ml, (584.89±116.49) pg/ml and (291.56±40.73) pg/ml, respectively. The concentrations of IL-6, IL-12 and TNF-α secreted by mDC+ pDC group were much higher than those of mDC group and pDC group under the same culture conditions (P<0.05). Conclusions: The mDCs and pDCs combined vaccines pulsed with heat-treated Lewis lung cancer cell lysates have synergistic effects on inducing of T lymphocyte proliferation and killing tumor cells in vitro. This synergistic anti-tumor effect is related with up-regulation of co-stimulatory molecules and increased secretion of cytokines.

[Comparison of the etiological constitution of two and three or more recurrent miscarriage].

Objective: To compare the etiological constitution of recurrent miscarriage (RM) between patients with consecutive two and three or more miscarriages through combining the routine examination results and embryonic karyotype. Methods: Patients with a history of two or more consecutive clinical miscarriages (≤12 weeks of gestation) consulting in the RM clinic of the First Affiliated Hospital of Sun Yat-sen University from March 2011 to January 2016 were collected. Six hundred and ninety-six with detailed history recorded, routine clinical examinations of RM and at least once embryonic karyotype were ultimately enrolled in this study. Their etiological constitution of RM were analyzed in groups of consecutive two and three or more miscarriage. The etiologies of RM in analysis consisted of women age, body mass index (BMI) , chromosome abnormalities of couples, uterine abnormalities, endocrinology abnormalities and antiphospholipid syndrome (APS) . Results: (1) Among 696 patients, the abnormal embryonic karyotypes was 60.6% (422/696) and routine RM etiologies was 32.2% (224/696) , leaving the ratio of unexplained RM was only 29.0% (202/696). (2) A total of 717 embryo karyotype were found in 696 patients, included21 cases with twice embryo karyotype results the percentage of normal embryo was 39.7% (285/717) , while abnormal ones was 60.3% (432/717). Among the types of abnormal karyotype, the most common ones (>10%) were trisomy 16 (19.2%, 83/432) , monosome X (11.3%, 49/432) and trisomy 22 (10.9%, 47/432). (3) Among the 696 RM patients, the number of two and three or more miscarriages were respectively 446 (64.1%, 446/696) and 250 (35.9%, 250/696). Comparing groups of three or more miscarriages with two miscarriages, there were significant differencein older age as well as uterine adhesion (P<0.05). But no difference was found in body mass index (BMI) , the rates of chromosome abnormalities of couples, uterine abnormalities except uterine adhesion, endocrinology abnormalities and APS (all P>0.05) between two groups. Conclusions: The abnormal embryonic karyotype is the most common cause of first-trimester RM. The etiological constitution of two and three or more recurrent miscarriages is accordant, suggesting that routine clinical examination and the embryonic karyotype should be started following two consecutive clinical early miscarriages.

Inhibition of STAT3 by RNA interference suppresses angiogenesis in colorectal carcinoma

In order to investigate signal transduction and activation of transcription 3 (STAT3) signaling on angiogenesis in colorectal carcinoma (CRC) after inhibiting STAT3 expression, we constructed the HT-29-shSTAT3 cell line by lentivirus-mediated RNAi. Cell growth was assessed with MTT and the cell cycle distribution by flow cytometry. CRC nude mouse models were established and tumor growth was monitored periodically. On day 30, all mice were killed and tumor tissues were removed. Microvessel density (MVD) was determined according to CD34-positive staining. The expression of vascular endothelial growth factor A (VEGFA), matrix metalloproteinase-2 (MMP2) and basic fibroblast growth factor (FGF2) was monitored by quantitative real-time PCR and Western blot analysis. Knockdown of STAT3 expression significantly inhibited cell growth in HT-29 cells, with a significantly higher proportion of cells at G0/G1 (P < 0.01). Consistently, in vivo data also demonstrated that tumor growth was significantly inhibited in mice injected with HT-29-shSTAT3 cells. MVD was 9.80 ± 3.02 in the HT-29-shSTAT3 group, significantly less than that of the control group (P < 0.01). mRNA and protein levels of VEGFA and MMP2 in the HT-29-shSTAT3 group were significantly lower than in the control group (P < 0.05), but no significant difference was observed in the mRNA or protein level of FGF2 (P > 0.05). Taken together, these results demonstrate that STAT3 signaling is important to the growth of CRC and promotes angiogenesis by regulating VEGFA and MMP2 expression.

Inhibition of STAT3 by RNA interference suppresses angiogenesis in colorectal carcinoma.

In order to investigate signal transduction and activation of transcription 3 (STAT3) signaling on angiogenesis in colorectal carcinoma (CRC) after inhibiting STAT3 expression, we constructed the HT-29-shSTAT3 cell line by lentivirus-mediated RNAi. Cell growth was assessed with MTT and the cell cycle distribution by flow cytometry. CRC nude mouse models were established and tumor growth was monitored periodically. On day 30, all mice were killed and tumor tissues were removed. Microvessel density (MVD) was determined according to CD34-positive staining. The expression of vascular endothelial growth factor A (VEGFA), matrix metalloproteinase-2 (MMP2) and basic fibroblast growth factor (FGF2) was monitored by quantitative real-time PCR and Western blot analysis. Knockdown of STAT3 expression significantly inhibited cell growth in HT-29 cells, with a significantly higher proportion of cells at G0/G1 (P < 0.01). Consistently, in vivo data also demonstrated that tumor growth was significantly inhibited in mice injected with HT-29-shSTAT3 cells. MVD was 9.80 ± 3.02 in the HT-29-shSTAT3 group, significantly less than that of the control group (P < 0.01). mRNA and protein levels of VEGFA and MMP2 in the HT-29-shSTAT3 group were significantly lower than in the control group (P < 0.05), but no significant difference was observed in the mRNA or protein level of FGF2 (P > 0.05). Taken together, these results demonstrate that STAT3 signaling is important to the growth of CRC and promotes angiogenesis by regulating VEGFA and MMP2 expression.

Correlating transfection barriers and biophysical properties of cationic polymethacrylates.

Transfection efficiencies of several polymeric gene carriers were compared and correlated quantitatively to the amounts of cellular accumulation of plasmid DNA and to the expression of mRNA by quantitative real-time polymerase chain reaction (real-time PCR). Three polycations polymers with similar chemical structure were used in this study: poly(dimethylamino)ethyl methacrylate (PDMA) homopolymer, PEO-b-PDMA copolymer, and PEO-b-poly(diethylamino)ethyl methacrylate (PEO-b-PDEA) copolymer. Despite their similar chemical structures, the transfection efficiencies were significantly different. PEO-b-PDEA copolymer was significantly less efficient as gene carrier as compared to both PDMA and PEO-b-PDMA. Correlations between cytotoxicity, cellular uptake of plasmid DNA, expression levels of transgene and protein, and the physical properties of the polymers were observed. With the PEO-b-PDEA studies, cytotoxicity was due primarily to the excess of polymers that did not participate in the DNA binding. In addition, the inability of the polymer/DNA polyplexes to interact with cell effectively was identified as a critical barrier for high efficiency of transfection. This study demonstrated that the use of quantitative real-time PCR in combination with physical characterization techniques could provide useful insights into the transfection barrier at different cellular levels.

Aggregation behavior and thermodynamics of binding between poly(ethylene oxide)-block-poly(2-(diethylamino)ethyl methacrylate) and plasmid DNA.

The aggregation behavior and the thermodynamics of binding between poly(ethylene oxide)-block-poly(2-(diethylamino)ethyl methacrylate) (PEO-b-PDEAEMA) block copolymers and plasmid DNA were examined. Binding between the polymer and DNA were confirmed by gel electrophoresis. The high affinity between the polymer and DNA was demonstrated through the ethidium bromide (EtBr) displacement assay, and the binding was found to be related to the stoichiometric balance between the amine group of the polymer and the DNA nucleotide molar ratio (N/P molar ratio). The light scattering and TEM results showed that, at low polymer concentration, the hydrodynamic radii (R(h)) of the polymer/DNA complexes was around 90 nm; however, at sufficiently high polymer concentration, the complexes condensed to around 35 nm induced by a structural rearrangement of the amphiphilic nature of the block copolymer. The isothermal titration calorimetric results showed that the binding between the polymer and DNA is driven by a large favorable enthalpy.

Association behavior of biotinylated and non-biotinylated poly(ethylene oxide)-b-poly(2-(diethylamino)ethyl methacrylate).

Biotinylated and non-biotinylated copolymers of poly(ethylene oxide) (PEO) and poly(2-(diethylamino)ethyl methacrylate) (PDEAEMA) were synthesized by the atom transfer radical polymerization technique. The chemical compositions of the copolymers as determined by NMR are represented by PEO(113)PDEAEMA(70) and biotin-PEO(104)PDEAEMA(93), respectively. The aggregation behavior of these polymers in aqueous solutions at different pHs and ionic strengths was studied using a combination of potentiometric titration, dynamic light scattering, static light scattering, and transmission electron microscopy. Both PEO-b-PDEAEMA and biotin-PEO-b-PDEAEMA diblock copolymers form micelles at high pH with hydrodynamic radii (R(h)) of about 19 and 23 nm, respectively. At low pH, the copolymers are dispersed as unimers in solution with R(h) values of about 6-7 nm. However, at a physiological salt concentration (c(s)) of about 0.16 M NaCl and a pH of 7-8, the copolymers form large loosely packed Gaussian chains, which were not present at the low c(s) of 0.001 M NaCl. The critical micelle concentrations (cmc's) and the cytotoxicities of the copolymers were investigated to determine a suitable polymer concentration range for future biological applications. Both PEO-b-PDEAEMA and biotin-PEO-b-PDEAEMA diblock copolymers possess identical cmc values of about 0.0023 mg/g, while the cytotoxicity test indicated that the copolymers are not toxic up to 0.05 mg/g (>83% cell survival at this concentration).