Investigation of multiple nosocomial infections using a semi-Markov multi-state model.

BACKGROUND: The prevalence of multiple nosocomial infections (MNIs) is on the rise, however, there remains a limited comprehension regarding the associated risk factors, cumulative risk, probability of occurrence, and impact on length of stay (LOS). METHOD: This multicenter study includes all hospitalized patients from 2020 to July 2023 in two sub-hospitals of a tertiary hospital in Guangming District, Shenzhen. The semi-Markov multi-state model (MSM) was utilized to analyze risk factors and cumulative risk of MNI, predict its occurrence probability, and calculate the extra LOS of nosocomial infection (NI). RESULTS: The risk factors for MNI include age, community infection at admission, surgery, and combined use of antibiotics. However, the cumulative risk of MNI is lower than that of single nosocomial infection (SNI). MNI is most likely to occur within 14 days after admission. Additionally, SNI prolongs LOS by an average of 7.48 days (95% Confidence Interval, CI: 6.06-8.68 days), while MNI prolongs LOS by an average of 15.94 days (95% CI: 14.03-18.17 days). Furthermore, the more sites of infection there are, the longer the extra LOS will be. CONCLUSION: The longer LOS and increased treatment difficulty of MNI result in a heavier disease burden for patients, necessitating targeted prevention and control measures.

Singlet oxygen induces cell wall thickening and stomatal density reducing by transcriptome reprogramming.

Singlet oxygen (1O2) has a very short half-life of 10-5 s; however, it is a strong oxidant that causes growth arrest and necrotic lesions on plants. Its signaling pathway remains largely unknown. The Arabidopsis flu (fluorescent) mutant accumulates a high level of 1O2 and shows drastic changes in nuclear gene expression. Only two plastid proteins, EX1 (executer 1) and EX2 (executer 2), have been identified in the singlet oxygen signaling. Here, we found that the transcription factor abscisic acid insensitive 4 (ABI4) binds the promoters of genes responsive to 1O2-signals. Inactivation of the ABI4 protein in the flu/abi4 double mutant was sufficient to compromise the changes of almost all 1O2-responsive-genes and rescued the lethal phenotype of flu grown under light/dark cycles, similar to the flu/ex1/ex2 triple mutant. In addition to cell death, we reported for the first time that 1O2 also induces cell wall thickening and stomatal development defect. Contrastingly, no apparent growth arrest was observed for the flu mutant under normal light/dim light cycles, but the cell wall thickening (doubled) and stomatal density reduction (by two-thirds) still occurred. These results offer a new idea for breeding stress tolerant plants.

ABO blood groups and nosocomial infection.

The timely identification of the high-risk groups for nosocomial infections (NIs) plays a vital role in its prevention and control. Therefore, it is crucial to investigate whether the ABO blood group is a risk factor for NI. In this study, patients with NI and non-infection were matched by the propensity score matching method and a logistic regression model was used to analyse the matched datasets. The study found that patients with the B&AB blood group were susceptible to Escherichia coli (OR = 1.783, p = 0.039); the A blood group were susceptible to Staphylococcus aureus (OR = 2.539, p = 0.019) and Pseudomonas aeruginosa (OR = 5.724, p = 0.003); the A&AB blood group were susceptible to Pseudomonas aeruginosa (OR = 4.061, p = 0.008); the AB blood group were vulnerable to urinary tract infection (OR = 13.672, p = 0.019); the B blood group were susceptible to skin and soft tissue infection (OR = 2.418, p = 0.016); and the B&AB blood group were vulnerable to deep incision infection (OR = 4.243, p = 0.043). Summarily, the patient's blood group is vital for identifying high-risk groups for NIs and developing targeted prevention and control measures for NIs.

Quantitative evaluation of the role of Fangcang shelter hospitals in the control of Omicron transmission: A case study of the outbreak in Shanghai, China in 2022.

Since Omicron began to spread in China, Shanghai has become one of the cities with more severe outbreaks. Under the comprehensive consideration of the vaccine coverage rate, the number of Fangcang shelter hospital beds and the number of designated hospital beds in Shanghai, this paper established a deterministic compartmental model and used the Nelder-Mead Simplex Direct Search Algorithm and chi-square values to estimate the model parameters. we calculate ℛ0 = 3.6429 when the number of beds in the Fangcang shelter hospital is relatively tight in the second stage and ℛ0 = 0.4974 in the fifth stage when there are enough beds in both Fangcang shelter hospital and designated hospital. Then we perform a sensitivity analysis on ℛ0 by using perturbation of fixed point estimation of model parameters in the fifth stage, and obtain three parameters that are more sensitive to ℛ0, which are transmission rate (ß 1d ), proportion of the infectious (η) and the hospitalization rate of asymptomatic infected cases (δ 1). Through simulation, we obtain that if the hospitalization rate of asymptomatic infections δ 2 > 0.9373 or the transmission rate ß 1b  < 0.0467, the second stage of Omicron transmission in Shanghai can be well controlled. Finally, we find the measure that converting the National Convention and Exhibition Center (NECC) into a Fangcang shelter hospital has played an important role in curbing the epidemic. Whether this temporary Fangcang shelter hospital is not built or delayed, the cumulative number of confirmed cases will both exceed 100,000, and the cumulative asymptomatic infections will both exceed 1 million. In addition, for a city of 10 million people, we obtain that if a permanent Fangcang shelter hospital with 17,784 beds is built ahead of epidemic, there will be no shortage of beds during the outbreak of Omicron. Our findings enrich the content of the impact of Fangcang shelter hospital beds on the spread of Omicron and confirm the correct policy adopted by the Chinese government.

The Impact of Quarantine and Medical Resources on the Control of COVID-19 in Wuhan based on a Household Model.

In order to understand how Wuhan curbed the COVID-19 outbreak in 2020, we build a network transmission model of 123 dimensions incorporating the impact of quarantine and medical resources as well as household transmission. Using our new model, the final infection size of Wuhan is predicted to be 50,662 (95%CI: 46,234, 55,493), and the epidemic would last until April 25 (95%CI: April 23, April 29), which are consistent with the actual situation. It is shown that quarantining close contacts greatly reduces the final size and shorten the epidemic duration. The opening of Fangcang shelter hospitals reduces the final size by about 17,000. Had the number of hospital beds been sufficient when the lockdown started, the number of deaths would have been reduced by at least 54.26%. We also investigate the distribution of infectious individuals in unquarantined households of different sizes. The high-risk households are those with size from two to four before the peak time, while the households with only one member have the highest risk after the peak time. Our findings provide a reference for the prevention, mitigation and control of COVID-19 in other cities of the world.

The influence of mask use on the spread of COVID-19 during pandemic in New York City.

In New York City, the situation of COVID-19 is so serious that it has caused hundreds of thousands of people to be infected due to its strong infectivity. The desired effect of wearing masks by the public is not ideal, though increasingly recommended by the WHO. In order to reveal the potential effect of mask use, we posed a dynamical model with the effective coverage of wearing face masks to assess the impact of mask use on the COVID-19 transmission. We obtained the basic reproduction number R 0 which determined the global dynamics. According to the implement of policies in New York City, we divided the transmission of COVID-19 in three stages. Based on mathematical model and data, we obtain the mean value R 0 = 1 . 822 in the first stage of New York City, while R 0 = 0 . 6483 in the second stage due to that the US Centers for Disease Control and Prevention (CDC) recommended the public wear masks on April 3, 2020, R 0 = 1 . 024 in the third stage after reopening. It was found that if the effective coverage rate of mask use α exceed a certain value α c = 0 . 182 , COVID-19 can be well controlled in the second stage of New York City. Additionally, when the effective coverage of masks reaches a certain level α = 0 . 5 , the benefits are not obvious with the increased coverage rate compared to the cost of medical resources. Moreover, if the effective coverage of mask use in public reaches 20% in the first stage, then the cumulative confirmed cases will be reduced about 50% by 03 April, 2020. Our results demonstrated a new insight on the effect of mask use in controlling the transmission of COVID-19.

Modeling the early transmission of COVID-19 in New York and San Francisco using a pairwise network model.

Classical epidemiological models assume mass action. However, this assumption is violated when interactions are not random. With the recent COVID-19 pandemic, and resulting shelter in place social distancing directives, mass action models must be modified to account for limited social interactions. In this paper we apply a pairwise network model with moment closure to study the early transmission of COVID-19 in New York and San Francisco and to investigate the factors determining the severity and duration of outbreak in these two cities. In particular, we consider the role of population density, transmission rates and social distancing on the disease dynamics and outcomes. Sensitivity analysis shows that there is a strongly negative correlation between the clustering coefficient in the pairwise model and the basic reproduction number and the effective reproduction number. The shelter in place policy makes the clustering coefficient increase thereby reducing the basic reproduction number and the effective reproduction number. By switching population densities in New York and San Francisco we demonstrate how the outbreak would progress if New York had the same density as San Francisco and vice-versa. The results underscore the crucial role that population density has in the epidemic outcomes. We also show that under the assumption of no further changes in policy or transmission dynamics not lifting the shelter in place policy would have little effect on final outbreak size in New York, but would reduce the final size in San Francisco by 97%.

Nonpharmaceutical interventions contribute to the control of COVID-19 in China based on a pairwise model.

Nonpharmaceutical interventions (NPIs), particularly contact tracing isolation and household quarantine, play a vital role in effectively bringing the Coronavirus Disease 2019 (COVID-19) under control in China. The pairwise model, has an inherent advantage in characterizing those two NPIs than the classical well-mixed models. Therefore, in this paper, we devised a pairwise epidemic model with NPIs to analyze COVID-19 outbreak in China by using confirmed cases during February 3rd-22nd, 2020. By explicitly incorporating contact tracing isolation and family clusters caused by household quarantine, our model provided a good fit to the trajectory of COVID-19 infections. We calculated the reproduction number R = 1.345 (95% CI: 1.230 - 1.460) for Hubei province and R = 1.217 (95% CI: 1.207 - 1.227) for China (except Hubei). We also estimated the peak time of infections, the epidemic duration and the final size, which are basically consistent with real observation. We indicated by simulation that the traced high-risk contacts from incubated to susceptible decrease under NPIs, regardless of infected cases. The sensitivity analysis showed that reducing the exposure of the susceptible and increasing the clustering coefficient bolster COVID-19 control. With the enforcement of household quarantine, the reproduction number R and the epidemic prevalence declined effectively. Furthermore, we obtained the resumption time of work and production in China (except Hubei) on 10th March and in Hubei at the end of April 2020, respectively, which is broadly in line with the actual time. Our results may provide some potential lessons from China on the control of COVID-19 for other parts of the world.

Comparison of two electronic hand hygiene monitoring systems in promoting hand hygiene of healthcare workers in the intensive care unit.

BACKGROUND: Hand hygiene (HH) is the cornerstone of infection control, and the promotion of HH is the focus of the world. The study aims to compare the role of two different types of electronic hand hygiene monitoring systems (EHHMSs) in promoting HH of healthcare workers (HCWs) in the intensive care unit (ICU). METHODS: In a 16-bed ICU of a general tertiary hospital in Shenzhen, the research was divided into three stages with interrupted time series (ITS) design. In the first stage, the direct observation method was used to monitor and feed back the HH compliance rate of HCWs monthly. In the second stage, the type1 EHHMS was applied to monitor and feed back the individual number of HH events monthly. In the third stage, the type2 EHHMS with a function of instant reminder and feedback was employed, and the personal HH compliance rates were fed back monthly. Meanwhile, direct observation continued in the last two stages. RESULTS: In the second stage, The HH compliance rate increased. However, there was no significant difference in the trajectory of the rate compared with the first stage. In the first month of the third stage, the HH compliance rate increased by 12.324% immediately and then ascended by 1.242% over time. The number of HH events per bed day and HH products' consumption per bed day were consistent with the change of HH compliance rate observed. CONCLUSION: Monitoring and feedback can improve the HH of HCWs. The EHHMS, with the function of real-time reminders and feedback, has a more noticeable effect on promoting HH.

A lysosome-targetable two-photon excited near-infrared fluorescent probe for visualizing hypochlorous acid-involved arthritis and its treatment.

Lysosome of phagocyte is the main site of hypochlorous acid (HClO) production, and HClO can be employed as the biomarker for the diagnosis and treatment evaluation of arthritis. In recent years, developing fluorescent probes for lysosomal HClO has attracted considerable attention, but most of them still have some defects, such as autofluorescence, phototoxicity and photobleaching because of their excitation and emission located in short-wavelength region. Due to the advantages of two-photon fluorescent probes with near-infrared emissions, a lysosome-targetable two-photon fluorescent probe (Lyso-TP-HClO) with a near-infrared emission was reported in this paper. Lyso-TP-HClO has a high selectivity and a high sensitivity to HClO in the linear range (10.0 × 10-8 to 5.0 × 10-6 M), with a detection limit of 3.0 × 10-8 M. Due to the two-photon excited near-infrared emission, Lyso-TP-HClO has excellent imaging performances, such as small autofluorescence, excellent photostability, and large imaging depth. Furthermore, Lyso-TP-HClO was successfully employed for visualizing lysosomal HClO in bacteria-infected cells. At last, we have successfully used Lyso-TP-HClO to image the arthritis and evaluate the treatment of arthritis in mice. All the results confirm that Lyso-TP-HClO is a useful chemical tool for imaging of lysosomal HClO, the diagnosis of arthritis, and treatment evaluation of arthritis.

Iron overload as a risk factor for poor graft function following allogeneic hematopoietic stem cell transplantation.

Hematological malignancies are increasingly treated with allogeneic hematopoietic stem cell transplantation (allo-HSCT). Unfortunately, iron overload is a frequent adverse effect of allo-HSCT and is associated with poor prognosis. In the present study, we investigated hematopoiesis in iron-overloaded mice and elucidated the effects of iron overload on the bone marrow (BM) microenvironment. Iron-overloaded BALB/C mice were generated by injecting 20 mg/mL saccharated iron oxide intraperitoneally. Hematoxylin-eosin staining was performed to evaluate the effects of an iron overload in mice. BM cells obtained from C57BL/6 mice were transplanted into irradiated BALB/C mice (whole-body irradiation of 4 Gy, twice with a 4-hours interval) by tail vein injection. Two weeks after allo-HSCT, the hematopoietic reconstitution capacity was evaluated in recipients by colony-forming assays. Histopathological examinations showed brown-stained granular deposits, irregularly arranged lymphocytes in the liver tissues, and blue-stained blocks in the BM collected from mice received injections of high-dose saccharated iron oxide (20 mg/mL). Iron-overloaded mice showed more platelets, higher-hemoglobin (HGB) concentration, fewer granulocyte-macrophage colony-forming units (CFU-GM), erythrocyte colony-forming units (CFU-E), and mixed granulocyte/erythrocyte/monocyte/megakaryocyte colony-forming units (CFU-mix) than healthy mice. Iron-overloaded recipients presented with reduced erythrocytes and HGB concentration in peripheral blood, along with decreased marrow stroma cells, CFU-GM, CFU-E, and CFU-mix relative to healthy recipients. Taken together, our findings demonstrate that iron overload might alter the number of red blood cells after transplantation in mice by destroying the BM microenvironment, thereby affecting the recovery of BM hematopoietic function.

Impact of a quality control circle on the incidence of catheter-associated urinary tract infection: An interrupted time series analysis.

BACKGROUND: To report a quality control circle (QCC) activity on the theme of reducing the incidence of catheter-associated urinary tract infection (CAUTI), and used an interrupted time series analysis to evaluate the impact of the QCC. METHODS: In a general tertiary hospital in Shenzhen, China, we carried out a QCC activity with the theme of reducing CAUTI from April 2017 to December 2017. Before the QCC, we carried out the routine measures; during the QCC, we implemented usual measures and the countermeasures of QCC, and after the QCC, we performed the routine measures and adhered to the core measures of QCC. The interrupted time series analysis method was used to analyze the changes in the CAUTI incidence during the 3 stages. RESULTS: Before, during, and after the QCC activities, the catheter use ratios and mean indwelling time both had a downward trend; meanwhile, the compliance rate of CAUTI prevention measures showed an upward trend. After the interventions, the CAUTI incidence decreased by 1.317‰ immediately, then gradually decreased by 0.510‰ per month. After the completion of QCC, the CAUTI incidence increased by 0.266‰ immediately and increased by 0.070‰ over time, but the difference was not statistically significant. CONCLUSIONS: The CAUTI incidence is reduced through QCC, providing a useful reference for the prevention of CAUTI and the development of medical quality improvement activities.

[Effect of Serum Free Light Chain on Renal Function and Prognosis in Patients with Newly Diagnosed Multiple Myeloma].

OBJECTIVE: To analyze the effect of serum free light chain (sFLC) on renal function and prognosis in patients with newly diagnosed multiple myeloma (MM). METHODS: The clinical data of 70 newly diagnosed MM patients who received sFLC examination in Fujian Medical University Union Hospital were retrospectively analyzed from April 2012 to November 2016. Univariate analysis was used to analyze the risk factors that associated with renal impairment (RI) and prognosis. Logistic regression and Kaplan-Meier analyze were used to analyze the roles of sFLC in RI and the prognosis. RESULTS: Out of the 70 patients, 20 patients had RI at the initial diagnosis. Compared to normal renal function group, RI group had lower level of hemoglobin, elevated levels of serum uric acid, corrected calcium, serum creatinine, serum ß2 microglobulin, and involved sFLC, higher proportion of patients with ISS stage III, involved sFLC≥500 mg/L, hemodialysis (all P＜0.05). Multivariate logistic regression analysis showed that serum uric acid≥430 µmol/L, ISS stage III and a involved sFLC≥500 mg/L were all the independent risk factors for RI in patients with newly diagnosed MM patients (all P＜0.05). Receiver operating characteristic (ROC) curves analysis showed that the involved sFLC was 705.0 mg/L, which was a best cut-off value area under curve (AUC) for prediting RI in patients with MM was 0.727 (P=0.003), sensitivity was 65.0% and specificity was 82.0%). After a median follow-up period of 31 (1-84) months, the median overall survival (OS) of patients with involved sFLC≥500mg/L and involved sFLC＜500 mg/L were 52.0 and 27.0 months, respectively, there was no statistically significant difference (P=0.137). There was also no statistically significant difference in median OS between the high sFLC ratio group (κ/λ＞32 or ＜0.03) and the low sFLC ratio group (0.03≤κ/λ≤32) (27 months vs 40 months, P=0.436). CONCLUSION: The involved sFLC in the RI group is significantly higher than that in the normal renal function group in newly diagnosed MM patients. Serum uric acid≥430 µmol/L, ISS stage III and involved sFLC≥500 mg/L are the independent risk factors for RI. Monitoring sFLC in newly diagnosed MM patients is helpful to the prediction of RI, and the involved sFLC level or sFLC ratio may not affect the prognosis of newly diagnosed MM patients.

Differential distributions of parvalbumin-positive interneurons in the sulci and gyri of the adult ferret cerebral cortex.

Although accumulating evidence suggests that there are significant anatomical and histological differences between the sulci and gyri of the cerebral cortex, whether there is a difference in the distribution of interneurons between the two cortical regions remains largely unknown. In this study, we systematically compared the distributions of parvalbumin-positive interneurons among three neighboring gyrus and sulcus pairs-coronal gyrus and cruciate sulcus, anterior ectosylvian gyrus and rostral suprasylvian sulcus, and posterior ectosylvian gyrus and pseudosylvian sulcus-in the adult ferret cerebral cortex. We proposed a method to partition sulci and gyri into several specific subregions through the deepest points of the sulci and the highest points of gyri in the inner and outer cortical contours of coronal sections. We found that the density of parvalbumin-positive interneurons in the gyri was significantly higher than that in the sulci. Further study revealed that the density of PV interneurons in superficial cortical layers (layers 2/3 and layer 4) was comparable among the three pairs of sulci and gyri. However, the density of parvalbumin-positive interneurons in cortical layers 5/6 was significantly higher in gyri than in sulci. These results indicate that parvalbumin-positive interneurons are differently distributed in infragranular layers of cortical sulci and gyri.

Prognostic significance of neutrophil to lymphocyte ratio in patients with gastrointestinal stromal tumors: A meta-analysis.

BACKGROUND: The neutrophil to lymphocyte ratio (NLR) is reported to be a prognostic factor in multiple malignancies. However, its prognostic value in patients with gastrointestinal stromal tumors (GISTs) remains controversial. This study aims to evaluate the prognostic value of preoperative NLR in GISTs. METHODS: MEDLINE, EMBASE, and, Cochrane databases were searched until February 2017. Eligible articles were defined as studies assessing the prognostic role of preoperative NLR in GISTs. The end points were overall survival (OS), disease-free survival (DFS), recurrence-free survival (RFS), and clinicopathological parameters. Pooled hazard ratios (HRs) or odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using fixed-effects/random-effects models. RESULTS: A total of eight studies comprising 1676 patients with GISTs were included. Elevated NLR had an association with decreased DFS/RFS (HR: 2.18, 95% CI: 1.30-3.67, P=0.003), but not OS (HR: 1.74, 95% CI: 0.63-4.84, P=0.29). The findings from most subgroup analyses were consistent with those from the overall analysis. Moreover, high NLR was significantly correlated with male, stomach lesion, tumor size (>5cm), tumor rupture (+), tumor recurrence (+), mitotic index (>5/50HPF), and NIH risk category (high/intermediate). CONCLUSIONS: Elevated preoperative NLR may be an unfavorable prognostic biomarker in patients with GISTs.

Cost Effectiveness of Imatinib, Dasatinib, and Nilotinib as First-Line Treatment for Chronic-Phase Chronic Myeloid Leukemia in China.

BACKGROUND AND OBJECTIVE: Tyrosine kinase inhibitors (TKIs) have obvious effects on chronic myeloid leukemia (CML), but they are expensive in China. Moreover, the overall cost of treatment of CML is high and the medical economic burden of patients with CML on the government is heavy. This study tested the cost effectiveness of imatinib, nilotinib, and dasatinib as first-line treatment in Chinese patients who were first diagnosed with chronic myeloid leukemia in the chronic phase (CML-CP). METHODS: A state-transition Markov model combining clinical effectiveness, utility, and cost data was used. Sensitivity analyses were conducted to determine the robustness of the model outcomes. RESULTS: The imatinib-first, dasatinib-first, and nilotinib-first strategy offered patients 9.76, 9.87, and 9.72 quality-adjusted life years (QALYs) at a cost of US$303,502.42, US$381,681.03, and US$305,509.92 over 20 years, respectively. The nilotinib-first strategy exhibited the lowest utility and highest price and was thus eliminated. An incremental cost-effectiveness analysis of the imatinib-first strategy and the dasatinib-first strategy showed that the dasatinib-first strategy yielded an incremental cost-utility ratio (ICER) of 710,714.64 $/QALY compared with the imatinib-first strategy, which exceeded the threshold; hence, the dasatinib-first strategy was not cost effective and was eliminated. The results were robust for multiple sensitivity analyses. CONCLUSION: From the perspective of the Chinese medical system, imatinib is likely to be more cost effective than dasatinib and nilotinib for patients who were first diagnosed with CML-CP.

Platelet to lymphocyte ratio in biliary tract cancer: Review and meta-analysis.

BACKGROUND: The platelet to lymphocyte ratio (PLR) has been found to predict clinical outcomes in multiple malignancies. The aim of this study was to assess the prognostic value of pretreatment PLR in biliary tract cancer (BTC). METHODS: We searched the MEDLINE, EMBASE, and Cochrane databases to identify studies evaluating the prognostic significance of pretreatment PLR in BTC. The end points were overall survival (OS), recurrence-free survival (RFS). Pooled hazard ratios (HRs) or odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using fixed-effects/random-effects models. RESULTS: A total of eleven studies comprising 2392 patients were included in the study. Pooled results showed that elevated PLR was significantly associated with decreased overall survival (HR: 1.59, 95% confidence interval [CI]: 1.42-1.78, p<0.001) and recurrence-free survival (HR: 1.53, 95% CI: 1.16-2.00, p=0.002). Subgroup analyses suggested that a high PLR predicted decreased OS in patient with BTC, regardless of sample size (<200 or ≥200), treatment methods (surgery, mixed, or chemotherapy), tumor stage (mixed or metastatic), analysis methods (univariate or multivariate), cut-off values (<150 or ≥150), and NOS score (<7 or ≥7). CONCLUSIONS: Elevated pretreatment PLR may be an unfavorable prognostic factor for clinical outcomes in patients with biliary tract cancer.

In vitro effects of reprogramming factors on the expressions of pluripotent genes and CD34 gene in human acute promyelocytic leukemia HL-60 cells.

OBJECTIVE: Our study aims to explore the in vitro effects of reprogramming factors on the expressions of pluripotent genes and CD34 gene in HL-60 cells. METHODS: According to the construction of lentiviral vector LV-OSCK of reprogramming factors (Oct-4, Sox2, Klf4, c-Myc), 293T cells were transfected to detect virus titer. The endogenous pluripotent genes (Oct4, SOX2, c-Myc and Klf4) and CD34 mRNA and protein expressions were detected by AP staining, immunofluorescence staining, qRT-PCR and flow cytometry. RESULTS: Expressions of Oct4, SOX2, c-Myc and Klf4 were 0.220±0.013, 0.186±0.009, 0.287±0.015 and 0.153±0.007. These levels were significantly higher in the experimental group than the control and blank groups. CD34 protein expression in the experimental group was also discovered to be significantly higher than the other two groups. CONCLUSION: The reprogramming factors could increase the expressions of pluripotent genes and CD34 gene in HL-60 cells.

Bone marrow-derived mesenchymal stem cells overexpressing MiR-21 efficiently repair myocardial damage in rats.

OBJECTIVE: We investigated the ability of bone marrow derived mesenchymal stem cells (BMSCs) overexpressing microRNA-21 (miR-21) to repair cardiac damage induced by anthracyclines in rats. METHODS: Sprague-Dawley (SD) rats of 2~3 weeks old were selected to isolate and culture BMSCs. A lentivirus harboring pLVX-miR-21 was generated and transfected into rat BMSCs. The rats were assigned into an untreated negative control group, and groups injected with adriamycin alone or with adriamycin followed by BMSCs, pLVX-BMSCs or pLVX-miR-21-BMSCs (n = 10 each). Proliferation and migration of cells were detected by cholecystokinin-8 (CCK- 8) and transwell. MiR-21 expression, mRNA expressions of B cell lymphoma 2 (Bcl2), BAX (BCL-2-associated X protein) and vascular endothelial growth factor (VEGF) were tested by qRT-PCR. Western blotting was applied to detect protein expressions of Bcl-2, Bax and VEGF. RESULTS: Using CCK- 8 and transwell assays, we found that pLVX-miR-21-BMSCs, which overexpressed miR-21, exhibited greater proliferation and migration than untransfected BMSCs or pLVX-BMSCs. Ultrasonic cardiograms and immunohistochemical analysis demonstrated that among the five groups, the pLVX-miR-21-BMSC group exhibited the most improved heart function and enhanced angiogenesis. Moreover, the pLVX-miR-21-BMSC group showed enhanced expression of Bcl-2, VEGF and Cx43 and reduced expression of Bax, BNP and troponin T. CONCLUSION: These findings suggest miR-21 overexpression enhanced the proliferation, invasiveness and differentiation of BMSCs as well as expression of key factors (Bcl-2, VEGF and Bax) essential for repairing the cardiac damage induced by anthracyclines and restoring heart function.

The Construction and Identification of Induced Pluripotent Stem Cells Derived from Acute Myelogenous Leukemia Cells.

OBJECTIVE: The present study aimed to establish an induced pluripotent stem cell (iPSC) line from acute myelogenous leukemia (AML) cells in vitro and identify their biological characteristics. METHODS: Cells from the AML-infiltrated skin from an M6 patient were infected with a lentivirus carrying OCT4, SOX2, KLF4 and C-MYC to induce iPSCs. The characteristics of the iPSCs were confirmed by alkaline phosphatase (ALP) staining. The proliferation ability of iPSCs was detected with a CCK-8 assay. The expression of pluripotency markers was measured by immunostaining, and the expression of stem cell-related genes was detected by qRT-PCR; distortion during the induction process was detected by karyotype analysis; the differentiation potential of iPSCs was determined by embryoid body-formation and teratoma-formation assays. ALP staining confirmed that these cells exhibited positive staining and had the characteristics of iPSCs. RESULTS: The CCK-8 assay showed that the iPSCs had the ability to proliferate. Immunostaining demonstrated that iPSC clones showed positive expression of NANOG, SSEA-3, SSEA-4, TRA-1-60 and TRA-1-81. qRT-PCR results revealed that the mRNA expression of Nanog, Lin28, Cripto, FOX3, DNMT3b, DPPA2, and DPPA4 significantly increased in iPSCs. Karyotype analysis found no chromosome aberration in the iPSCs. The results of the embryoid body-formation and teratoma-formation assays indicated that the iPSCs had the potential to differentiate into all three germ layers. CONCLUSION: Our study provided evidence that an iPSC line derived from AML cells was successfully established.