The Dynamic Mechanical Properties and Damage Constitutive Model of Ultra-High-Performance Steel-Fiber-Reinforced Concrete (UHPSFRC) at High Strain Rates

A high strain rate occurs when the strain rate exceeds 100 s-1. The mechanical behavior of materials at a high strain rate is different from that at middle and low strain rates. In order to study the dynamic compressive mechanical properties of ultra-high-performance steel-fiber-reinforced concrete (UHPSFRC) at high strain rates, an electro-hydraulic servo universal testing machine and a separate Hopkinson pressure bar (SHPB) with a diameter of 120 mm were used, respectively. A quasi-static compression test (strain rate 0.001 s-1) and impact compression test with a strain rate range of 90~200 s-1 were carried out to study the failure process, failure mode, and stress-strain curve characteristics of UHPSFRC at different strain rates and quantify the strain rate strengthening effect and fiber toughening effect. Based on the statistical damage theory and energy conversion principle, a dynamic damage constitutive model considering the effects of strain rate and fiber content was constructed. The results showed that the rate correlation of UHPSFRC and the fiber toughening properties showed a certain coupling competition mechanism. When the fiber content was less than 1.5%, with an increase in the steel fiber content, the crack initiation and propagation time of the specimen was extended, and the strain rate sensitivity gradually decreased. When the fiber content was 2%, the impact compressive strength of the specimen was optimal. Compared with UHPC, the dynamic increase factor (DIF) of UHPSFRC was significantly lower. The dynamic damage constitutive model established in this paper, considering the influence of strain rate and fiber content, has a good applicability and can describe the mechanical behavior of UHPSFRC at a high strain rate.

Nickel-Catalyzed Reductive Arylation of α-Bromo Sulfoxide

A nickel-catalyzed cross-electrophile coupling of aryl iodides with α-bromo sulfoxide to access a diverse array of aryl benzyl sulfoxides has been discovered. These reactions occurred under mild conditions with excellent functional group tolerance so that optically enriched sulfoxides could be coupled with aryl iodides, generating corresponding sulfoxides with excellent stereochemical integrity. Furthermore, the scalability of this transformation was demonstrated. Initial mechanistic studies revealed that the reaction undergoes a radical pathway.

Predicting willingness to donate blood based on machine learning: two blood donor recruitments during COVID-19 outbreaks

Machine learning methods are a novel way to predict and rank donors' willingness to donate blood and to achieve precision recruitment, which can improve the recruitment efficiency and meet the challenge of blood shortage. We collected information about experienced blood donors via short message service (SMS) recruitment and developed 7 machine learning-based recruitment models using PyCharm-Python Environment and 13 features which were described as a method for ranking and predicting donors' intentions to donate blood with a floating number between 0 and 1. Performance of the prediction models was assessed by the Area under the receiver operating characteristic curve (AUC), accuracy, precision, recall, and F1 score in the full dataset, and by the accuracy in the four sub-datasets. The developed models were applied to prospective validations of recruiting experienced blood donors during two COVID-19 pandemics, while the routine method was used as a control. Overall, a total of 95,476 recruitments via SMS and their donation results were enrolled in our modelling study. The strongest predictor features for the donation of experienced donors were blood donation interval, age, and donation frequency. Among the seven baseline models, the eXtreme Gradient Boosting (XGBoost) and Support vector machine models (SVM) achieved the best performance: mean (95%CI) with the highest AUC: 0.809 (0.806-0.811), accuracy: 0.815 (0.812-0.818), precision: 0.840 (0.835-0.845), and F1 score of XGBoost: 0.843 (0.840-0.845) and recall of SVM: 0.991 (0.988-0.994). The hit rate of the XGBoost model alone and the combined XGBoost and SVM models were 1.25 and 1.80 times higher than that of the conventional method as a control in 2 recruitments respectively, and the hit rate of the high willingness to donate group was 1.96 times higher than that of the low willingness to donate group. Our results suggested that the machine learning models could predict and determine the experienced donors with a strong willingness to donate blood by a ranking score based on personalized donation data and demographical details, significantly improve the recruitment rate of blood donors and help blood agencies to maintain the blood supply in emergencies.

[The ineffective or short-term recurrence of trigeminal neuralgia after microballoon compression:different causes and management strategies]

Objectives: To explore the causes of ineffective or short-term recurrence (within 3 months)of trigeminal neuralgia treated by percutaneous microballoon compression(PBC), and to examine the reoperative strategies and clincal outcomes of modified PBC. Methods: The clinical data of 21 patients with ineffective or short-term recurrence after PBC treatment (5.7% of 369 patient received PBC) admitted to the Department of Neurosurgery,Nanjing Drum Tower Hospital Clinical College of Nanjing Medical University from June 2018 to June 2020 were retrospectively analyzed.There were 8 males and 13 females, mean aged 66.6 years (range:51 to 79 years).Among them,2 patients was ineffective after PBC and 19 patients relapsed within 3 months.The distribution of pain was along V₂ branches in 2 cases,V₃ branches in 3 cases,V₁+V₂ branches in 1 case,and V₂+V₃ branches in 15 cases.The mean time of recurrence was 46.8 days (range:23 to 76 days) among the 19 patients with short-term recurrence.The patients were divided into 4 types based on the causes of postoperative ineffectiveness or short-term recurrence.TypeⅠ:extracapsular false pear (1 case);Type Ⅱ:invalid true pear(2 cases);Type Ⅲ:capsular rupture (6 cases);Type Ⅳ:compression blind area (12 cases).The individualized modified PBC operation plans were used according to the types of the patients and the clinical effect and complications of the patients were observed. Results: The pain symptoms of the patients disappeared after the second operation with immediate effective rate of 100%. All patients had mild facial numbness after surgery.Five patients(23.8%,5/21) had masseter muscle weakness, 3 (14.3%,3/21) had peristomatous herpes, 1(4.8%, 1/21) had diplopia.No bleeding or other complications occurred.All patients were followed up for at least 12 months (range:13 to 28 months). One patient (4.8%,1/21) (compression blind area type) had pain recurrence 9 months after surgery, and cured by receiving the original modified PBC surgery again with no recurrence after another 13 months' follow-up. None of the other patients relapsed during the follow-up period.Up to the last follow-up,19 cases(90.5%,19/21) were cured,and 2 cases (9.5%,2/21) were relieved. Conclusions: The main reason for ineffective or short-term recurrence of PBC in trigeminal neuralgia patients is the ineffectively compressed of trigeminal ganglion.According to the different types of patients,the use of individualized modified surgical scheme can improve the efficacy of PBC surgery.

Enhancing the interfacial stability of LiNi0.8Co0.15Al0.05O2 cathode materials by a surface-concentration gradient strategy

Ni-rich LiNi_0.8Co_0.15Al_0.05O₂ materials have been successfully applied in electric vehicles due to the merits of high energy density which can meet the requirements for driving range. Nevertheless, the electrochemical performances of Ni-rich materials are limited by their structural instability. Herein, LiNi_0.8Co_0.15Al_0.05O₂ materials with the concentration-gradient structure of a Ni-rich core and a Co-rich surface were synthesized. The electrochemical results indicate that surface-concentration gradient LiNi_0.8Co_0.15Al_0.05O₂ provides improved electrochemical performance. It not only displays an initial Coulomb efficiency of 82.4%, and a capacity retention of 80.37% after 200 cycles at 25 °C, but also shows a capacity retention of 77.76% after 150 cycles at a high temperature of 55 °C. These excellent performances can be attributed to adjusting the distribution of Ni on the surface of the LiNi_0.8Co_0.15Al_0.05O₂ material, which inhibits the interfacial reaction between the material surface and electrolyte, lowers the consumption of active Li⁺ and decreases the interfacial film impedance. Moreover, less Ni content on the material surface is beneficial for reducing the formation of a NiO rock salt phase during the charging process and inhibits the surface structural evolution. The proposed method and detected mechanism will provide guidance for the design of cathode materials and their practical industrial applications.

Research Progress on Computer-Aided Skeleton-Based Individual Identification in Forensic Radiology

Abstract

Individual identification based on imaging data of the skeleton of a corpse is a key technique for forensic identification. To reduce the influence of artificial factors, computer-aided semi-automatic or automatic individual identification has become one of the research directions of skeleton-based individual identification in forensic radiology. Therefore, this paper reviews and summarizes literatures related to estimation of anthropological information such as, age and sex by computer-aided forensic radiology bone characteristics and individual identification based on bone imaging characteristics, in order to provide reference on skeleton-based individual identification in forensic radiology.

Forensic Application of Plant Evidence

Abstract

With the increasingly obvious role of plant evidence in case detection, forensic botany, which provides clues and evidence in crime scene investigation by using botanical research method has attracted growing attention. The common experimental techniques used in forensic botany are morphological examination, physical and chemical examination, molecular genetic examination, and so on. This paper briefly expounds the advantages and disadvantages of different test methods, summarizes the problems that need to be paid attention to in the application of forensic botany by arranging the related literatures and cases of forensic botanical research, in order to provide reference for scene investigation of cases.

Rab11B participates in erythrocyte storage lesion of under-collected whole blood

BACKGROUND AND OBJECTIVES

The storage lesion of the red blood cell affects the life span of RBC and the quality of blood component. The elucidation of this mechanism is helpful to reduce the storage damage of RBC and improve the efficacy and safety of blood transfusion. The aim of this study was to discover the potential molecular mechanism of erythrocyte storage lesion with Under-collected whole blood (UC-WB) model.

METHODS

The label-free MS/MS quantitative method was used to identify the differential proteins of erythrocyte membrane proteins and the difference of Rab11B, V-ATPase and plasma GDI2 protein expression were further verified by western blot at the end of blood storage.

RESULTS

A total of 12 Rab proteins and 3 interacting effector proteins were identified among the membrane protein of normal WB and UC-WB, including 5 differential Rab proteins and 2 interacting effector proteins. Compared with normal WB, the expression of membrane Rab11B protein and ATP6V1B1/2 subunit of V-ATPases protein as well as the plasma GDI2 protein of UC-WB increased at the end of storage period.

CONCLUSION

Rab protein might be related to RBC storage lesions, Rab11B participates in the RBC storage lesion through Rab11B/V-ATPases pathways.

Research on Fractal Characteristics and Energy Dissipation of Concrete Suffered Freeze-Thaw Cycle Action and Impact Loading

In order to study the fractal characteristics and energy dissipation of concrete suffered freeze-thaw cycle actions and impact loading, C35 concrete was taken as the research object in this paper, and freeze-thaw cycle tests were carried out with a freeze-thaw range of -20 °C~20 °C and a freeze-thaw frequency of 0~50 times. The degradation characteristics of concrete material and the variation rules of basic physical parameters under various freeze-thaw cycle conditions were obtained consequently. By using the SHPB (separated Hopkinson pressure bar) test device, impact compression tests of concrete specimens under different freeze-thaw cycle actions were developed, then the process of impact crushing and the mechanism of damage evolution were analyzed. Based on the screening statistical method and the fractal theory, the scale-mass distribution rules and fractal dimension characteristics of crushing blocks are investigated. Furthermore, the absorption energy, fracture energy and block kinetic energy of concrete under different conditions were calculated according to the energy dissipation principle of SHPB test. The relationship between the energy consumption density and the fractal dimension of fragments was established, and the coupling effect mechanism of freeze-thaw cycle action and strain rate effect on the fractal characteristics and energy consumption was revealed additionally. The research results show that the concrete under different freeze-thaw cycle conditions and impact loading speeds has fractal properties from the microscopic damage to the macroscopic fracture. The energy dissipation is intrinsically related to the fractal characteristics, and the energy consumption density increases with the increase of the fractal dimension under a certain freeze-thaw cycle condition. When at a certain loading speed, with the growth of freeze-thaw cycles, the energy consumption density reduces under the same fractal dimension, while the fractal dimension improves under the same energy consumption density.

Combination of LINE-1 hypomethylation and RASSF1A promoter hypermethylation in serum DNA is a non-invasion prognostic biomarker for early recurrence of hepatocellular carcinoma after curative resection

Hepatocarcinogenesis, a multistep process, involves not only genetic mutations but also epigenetic alterations. Widespread of global DNA hypomethylation is accompanied with specific regional hypermethylation especially at tumor suppressor genes' promoters. The aim of this study is to determine the efficacy of combined DNA methylation analysis of a global DNA methylation marker - LINE-1 and a tumor suppressor gene highly associated with the malignancy of HCC- RASSF1A in serum as a novel prognostic marker for diagnosis of early recurrence after curative resection.LINE-1 was hypomethylated in 66.7% (70/105) and RASSF1A promoter was hypermethylated in 73.3% (77/105) of HCC serum DNA samples by methylation specific PCR, but in none of the healthy controls: LINE-1 hypometylation (0/50) and RASSF1A hypermethylation (0/50). A significant association was found between LINE-1 hypomethylation and clinical pathologic features including HBsAg positivity (p=0.009), tumor size (p=0.001) and AFP levels (p<0.001). Besides, significant correlation was detected between RASSF1A promoter hypermethylation and lymph nodes metastasis (p=0.045).The results of Kaplan-Meier estimates of survival suggested that LINE-1 hypomethylation was highly associated with poor survival of patients (disease-free survival p=0.002, overall survival p=0.0123). More importantly, co-evaluation of LINE-1 hypomethylation and RASSF1A promoter hypermethylation was found to be significantly correlated to early recurrence and poor prognosis (disease-free survival p=0.0001, overall survival p=0.05) in patients after curative resection.In conclusion, our study showed that the combined examination of LINE-1 hypomethylation and RASSF1A promoter hypermethylation was effective in predicting early recurrence of HCC after curative resection. Patients with dual positivity of LINE-1 hypomethylation and RASSF1A promoter hypermethylation should be supplied with more intensive care and close follow-up after they undergo tumor resection.

CRISPR-Cas13a Nanomachine Based Simple Technology for Avian Influenza A (H7N9) Virus On-Site Detection

It is urgent to find an avian influenza A H7N9 detection simple method which is suitable for on-site detection. The Cas13a protein just likes a nanomachine, when specifically bound to target RNA by single-stranded RNA (crRNA), changes its protein structure and produces RNase activity, which degrades RNA non-specifically. Harnessing Cas13a, the paper aims to establish an underlying on-site H7N9 virus nucleic acid detection method. LwCas13a protein nanomachine was expressed in a prokaryotic expression system and purified by nickel column. In vitro transcribed RNA of H7N9 HA gene has been used as a target, to design a specific crRNA. The activity of Cas13a was verified with a single-stranded RNA-bound fluorescent group and a quenching fluorophore as signals. Using Cas13a, a room temperature H7N9 detection system was established. Detection of 1 nm of single-stranded RNA can be done within 5 min. When combined with the RT-RPA and T7 transcription system at room temperature, the detection limits of HA and NA are 1 fM and the reaction time is 50 min. Excellent specificity was achieved by comparison with subtype viruses such as H1N1 and H5N1. The rapid detection method based on CRISPR-Cas13a nanomachine H7N9 has been successfully established, which can detect H7N9 quickly and specifically. In the future, it can be quickly detected in the field with portable fluorescence detector.

MicroRNA-375 regulates proliferation and apoptosis of glioma cancer cells by inhibiting CTGF-EGFR signaling pathway

AIM

To evaluate the correlation between miRNA-375 and cell proliferation and apoptosis in glioma cancer cell.

METHODS

Collecting 30 cases of glioma cancer patients and 30 cases of cerebral infarction patients. The miRNA-375 and CTGF protein expressions were evaluated by ISH and IHC methods. In the cell experiment, the U87 cells were divided into 3 groups: NC group (the cells were treated with normal method); BL group (the cells were transfected with empty vector) and miRNA group (the cells were transfected with miRNA-375). The U87 cell proliferation and apoptosis rates and cell cycle of the different groups were measured by MTT and flow cytometry. The relative proteins (CTGF, EGFR, AKT, Erk and P21) expressions were measured by WB assay.

RESULTS

The miRNA-375 and CTGF expressions of glioma cancer tissues were significantly different compared with those of no-cancer tissues (p < 0.05, respectively). In the cell experiments, the cell proliferation of miRNA group was significantly decreased compared with that of NC group (p < 0.05); the cell apoptosis and G1 phase rate of miRNA group was significantly decreased compared with NC group (p < 0.05, respectively). Depending on the WB assay, the CTGF, EGFR, AKT, Erk and P21 proteins expressions of miRNA group were significantly different compared with proteins expressions of NC group (p < 0.05, respectively).

CONCLUSION

miRNA-375 over-expression suppresses glioma cancer cells development via CTGF-EGFR pathway (Fig. 3, Ref. 30).

Analysis of hemorrhagic fever with renal syndrome and its pathogenic gene sequence based on geographic information system

This study analyzed the temporal-spatial distribution characteristics, epidemiological characteristics and gene sequences of hemorrhagic fever with renal syndrome (HFRS) in Guangxi, with the intention of providing a theoretical and technical support for the prevention of HFRS. A map of the incidence of HFRS of different cities in Guangxi was drawn up using the Geographic Information System (GIS) to investigate the epidemiological characteristics and infection source of HFRS between 2013 and 2016. Guangxi has a low incidence of HFRS, and autumn and winter are the main high-incidence seasons. Cases of HFRS were reported in all regions in Guangxi except Laibin city between 2013 and 2016. The distribution of cases in the four years suggested that Guilin, Nanning, Hechi and Wuzhou were the main infected regions, especially the local areas in the north of Guilin. The nucleotide and amino acid of S fragment and M fragment of Hantaviruses (HV) detected were highly homologous, and no obvious variation was found. Through analyzing the space-time characteristics, epidemiological characteristics and gene sequence of HFRS in Guangxi, it was found that areas rich in water, grass and moisture, such as paddy fields, are the main active areas for the host of HFRS.

Integration of Nucleic Acid Extraction Protocol with Automated Extractor for Multiplex Viral Detection

The isolation of nucleic acids (NA) is the preliminary step to carry out genetic studies and DNA biosensor development. The presence of inhibitors in the purified NA interferes with the downstream application. These salts and other organic contaminations particularly challenge the analytical sensitivity of DNA biosensors. The detailed study was carried out to optimize the factors which might affect viral nucleic acid purification. The results suggested that 6 M guanidinium hydrochloride salt concentration was critical for NA isolation. The inverse relation has been found in the pH of the lysis buffer and quality and quantity of NA. The NA yield was relatively stable at pH 4–5. It has been observed that the use of carrier RNA was indispensable for viral genome isolation. The addition of ethanol to lysate in 1:1 ratio greatly improved NA recovery. The elution efficiency of DNase and RNase free water, 1× TE buffer and 1× PCR buffer was compared. The carrier RNA was best eluted in DNase and RNase free water and 1× TE buffer. It was further demonstrated that this method can be automatized for high throughput detection. A simple experiment was conducted to optimize the different parameters of an automated NA extractor to simultaneously extract HBV DNA and HCV RNA. The purified NA was successfully amplified in PCR and RT-PCR to verify the reliability of the established protocol. Thus a semi-automated system for the simultaneous detection of multiple viruses has been demonstrated.

Long spacer arm-functionalized magnetic nanoparticle platform for enhanced chemiluminescent detection of hepatitis B virus

A simple and cost-effective platform based on conjugating long spacer arms (LSA) onto magnetic nanoparticles (MNPs) was developed to enhance the chemiluminescent (CL) detection of pathogens. The modification method is both convenient and practical because it utilizes the commercially available macromolecule, carboxymethylated glucan (CMG), as the LSA. CMG-MNPS are designed to have low steric hindrance and high suspension properties, which allow for facile modification and hybridization reactions that enhance the CL sensitivity and detection. The infectious pathogen, hepatitis B virus (HBV) was selected for feasibility testing on this platform. The biotinylated amplicon of HBV, obtained by polymerase chain reaction (PCR), was hybridized to DNA probes functionalized on CMG-MNPs. The magnetic complexes were then incubated with streptavidin-alkaline phosphatase (SA-AP) to form linkages through biotin-streptavidin interactions. Finally, the magnetic complexes were mixed with 3-(2'-spiroadamantyl)-4-methoxy-4-(3"-phosphoryoxy)-phenyl-1,2-dioxetane (AMPPD) to generate CL signals that were proportional to the concentration of the HBV target. The detection of HBV with CMG-MNPs was more sensitive than that with the conventional carboxylated MNPs (CMNPs, succinic anhydride-modified MNPs). When optimized, the novel method showed high specificity and a detection limit of 0.5 pM. This new platform shows promise for the early clinical diagnosis of infectious diseases.

Chemiluminescent labels released from long spacer arm-functionalized magnetic particles: a novel strategy for ultrasensitive and highly selective detection of pathogen infections

Previously, the unique advantages provided by chemiluminescence (CL) and magnetic particles (MPs) have resulted in the development of many useful nucleic acid detection methods. CL is highly sensitive, but when applied to MPs, its intensity is limited by the inner filter-like effect arising from excess dark MPs. Herein, we describe a modified strategy whereby CL labels are released from MPs to eliminate this negative effect. This approach relies on (1) the magnetic capture of target molecules on long spacer arm-functionalized magnetic particles (LSA-MPs), (2) the conjugation of streptavidin-alkaline phosphatase (SA-AP) to biotinylated amplicons of target pathogens, (3) the release of CL labels (specifically, AP tags), and (4) the detection of the released labels. CL labels were released from LSA-MPs through LSA ultrasonication or DNA enzymolysis, which proved to be the superior method. In contrast to conventional MPs, LSA-MPs exhibited significantly improved CL detection, because of the introduction of LSA, which was made of water-soluble carboxymethylated β-1,3-glucan. Detection of hepatitis B virus with this technique revealed a low detection limit of 50 fM, high selectivity, and excellent reproducibility. Thus, this approach may hold great potential for early stage clinical diagnosis of infectious diseases.

Elevation of MMP-9 and IDO induced by pancreatic cancer cells mediates natural killer cell dysfunction

Background

Natural killer (NK) cells play a key role in non-specific immune response in different cancers, including pancreatic cancer. However the anti-tumor effect of NK cells decreases during pancreatic cancer progression. The regulatory pathways by which NK cells facilitate tumor immune escape are unclear, therefore our purpose was to investigate the roles of the contributory factors.

Methods

NK cells isolated from fresh healthy peripheral blood were co-cultured with normal human pancreatic ductal cells hTERT-HPNE and human pancreatic cancer cell lines SW1990 and BxPc-3 in vitro. Then NK cell function was determined by Flow cytometric analysis of surface receptors and cytotoxic granules in NK cells, NK cell apoptosis and cytotoxicity, and Enzyme-linked immunosorbent assay of cytokines. Expression level of MMP-9, IDO and COX-2 in hTERT-HPNE and SW1990 cells were detected by quantitative RT-PCR. Statistical differences between data groups were determined by independent t-tests using SPSS 19.0 software.

Results

Our results showed that NK cell function was significantly downregulated following exposure to pancreatic cancer cells compared to normal pancreatic cells, as demonstrated by lower expressions of activating surface receptors (NKG2D, DNAM-1, NKp30 and NKp46) and cytotoxic granules (Perforin and Granzyme B); decreased secretion of cytokines (TNF-α and IFN-γ); and reduced cytotoxicity against myelogenous leukemia K562 cells. Further investigations revealed that MMP-9 and IDO may be implicated in SW1990 cell-induced NK cell dysfunction by facilitating tumor immune evasion. Blockade by TIMP-1 and/or 1-MT could partially restore NK function.

Conclusions

Taken together, elevation of MMP-9 and IDO induced by pancreatic cancer cells mediates NK cell dysfunction. Our findings could contribute to the development of NK cell-based immunotherapy in patients with pancreatic cancer.

Solid-phase hybridization efficiency improvement on the magnetic nanoparticle surface by using dextran as molecular arms

For reducing the steric hindrance and nonspecific binding of the target DNA, the dextran was used as molecular arms to be immobilized on the surface of magnetic nanoparticles (MNPs). Magnetic separation was used in preparation of dextran-MNPs (DMNPs). Aspartic acid and aminated DNA probe were successively modified on the dextran immobilized on the surface of MNPs. These probe-DMNPs were successfully applied to detect biotin-labeled PCR product of E. coli O157:H7 genome by hybridization. Then the complexes were bonded with streptavidin-modified alkaline phosphatase (ALP-SA). Finally the chemiluminescent signals were detected by adding 3-(2-spiroadamantane)-4-methoxy-4- (3-phosphoryloxy) phenyl-1,2-dioxetane (AMPPD). The results showed that this method had a good specificity, and higher sensitivity than that when only MNPs were used as solid carriers.

[The serological and genetic identification of a CisAB blood sample]

OBJECTIVE

To verify the DNA sequence of a sample serologically identified as CisAB.

METHODS

Forward and reverse group methods were used to determine the blood serological type of that the sample, and PCR-sequence specific primer (PCR-SSP) method was used for genotyping the sample.

RESULTS

Serologically, the forward group test showed that the sample was AB, while the reverse group test showed that the sample had the anti-B and anti-H + + +. The auto antibodies were negative. PCR-SSP assay showed the sample was CisAB01. ABO genetic locus sequencing showed c.261delG in exon 6, c.297 was homozygous AA. Mutations c.467C to T and c.803G to C were found in exon 7. A novel heterozygous mutation, c.724G to T, was detected.

CONCLUSION

The serological phenotype of the specimen was CisAB. The genotype was ABO *CisAB01 and ABO *O01. A novel mutation c.724G to T in exon 7 was identified (GenBank accession no. JF304777).

Enhanced induction of anti-tumor CTLs in vitro by a lentivirus-transduced dendritic cell vaccine expressing secondary lymphoid tissue chemokine and mucin 1

AIMS

Dendritic cell (DC)-based cancer immunotherapy requires an immunogenic tumor associated antigen (TAA) and an effective strategy for its presentation to lymphocytes. Here, we explored whether transduction of DCs with lentiviruses (LVs) expressing a fusion protein of secondary lymphoid tissue chemokine (SLC) and mucin 1 (MUC1) could stimulate antigen-specific cytotoxic T cells (CTLs) to human cancer cells in vitro.

MATERIALS AND METHODS

HLA-A2+ peripheral blood monocyte-derived DCs were transduced with recombinant lentiviruses LV at different multiplicities of infection (MOI), and MUC1, SLC or SLC-MUC1 mRNA and protein were detected by RT-PCR and Western blotting, respectively. Transduction efficiencies and phenotypes of DCs were evaluated by flow cytometry. Induction of T lymphocyte proliferation by DCs was examined with a Cell Count Kit-8 (CCK-8). CTL activities against tumor cells were analyzed by lactate dehydrogenase (LDH) cytotoxicity and enzyme-linked immunospot (ELISPOT) assays.

RESULTS

Stable expression of MUC1, SLC and SLC-MUC1 was obtained in DCs transduced with recombinant LVs, and the transduction efficiencies were dose-dependent. Transduction with LVs did not appreciably change the DC phenotype. CTL induced by LV MUC1 DCs potently and specifically lysed the HLA-A2+, MUC1+colon cancer cell line HCT-116. Moreover, this cytolytic activity against HCT-116 was enhanced with CTL stimulated by LV SLC-MUC1 DCs.

CONCLUSIONS

DCs transduced with MUC1 could induce effective cytolytic activity against tumor cells in an antigen-specific and HLA-restricted fashion in vitro, and SLC promoted MUC1-specific anti-tumor activity. The transduction of DCs with LV SLC- MUC1 may be a promising strategy in DC-based cancer immunotherapy.

The increase in the expression and hypomethylation of MUC4 gene with the progression of pancreatic ductal adenocarcinoma

The MUC4 gene could have a key role in the progression of pancreatic cancer, but the quantitative measurement of its expression in clinical tissue samples remains a challenge. The correlations between MUC4 promoter methylation status in vivo and either pancreatic cancer progression or MUC4 mRNA expression need to be demonstrated. We used the techniques of quantitative real-time PCR and DNA methylation-specific PCR combined microdissection to precisely detect MUC4 expression and promoter methylation status in 116 microdissected foci from 57 patients with pancreatic ductal adenocarcinoma. Both mRNA expression and hypomethylation frequency increased from normal to precancerous lesions to pancreatic cancer. Multivariate Cox regression analysis showed that high-level MUC4 expression (P = 0.008) and tumor-node-metastasis staging (P = 0.038) were significant independent risk factors for predicting the prognosis of 57 patients. The MUC4 mRNA expression was not significantly correlated with promoter methylation status in 30 foci of pancreatic ductal adenocarcinoma. These results suggest that high mRNA expression and hypomethylation of the MUC4 gene could be involved in carcinogenesis and in the malignant development of pancreatic ductal adenocarcinoma. The MUC4 mRNA expression may become a new prognostic marker for pancreatic cancer. Microdissection-based quantitative real-time PCR and methylation-specific PCR contribute to the quantitative detection of MUC4 expression in clinical samples and reflect the epigenetic regulatory mechanisms of MUC4 in vivo.

[Effects of vitamin K on bone metabolism in tail-suspended rats]

Objective. To study the effects of vitamin K on bone metabolize in simulated weightlessness rats. Method. Male SD rats were divided into three groups (n = 9): the free active control (FAC), the tail-suspended control (SC), and the tail-suspended group treated with vitamin K (SVK) (50 mg/kg weight/d). The experiment lasted for 3 weeks. Bone biomechanical properties, bone mineral contents (BMC) and bone biochemical markers of bone metabolism were determined. Result. Compared with SC, total and bound bone gla protein (BGP) of serum, BMC of the femur and tibia, femoral mechanical properties, ALP activity of tibia all increased significantly; while NO content of femoral trunk decreased significantly. Conclusion. Vitamin K improved the bone metabolism and bone structure, decreased bone loss, increased bone biomechanical properties, decreased catagmatic fatalness. It proved that vitamin K prevented bone loss of simulated weightlessness rats.