[Analysis of efficacy and prognosis of allogeneic hematopoietic stem cell transplantation for the treatment of combined immunodeficiency]

Objective: To evaluate the efficacy of allogeneic hematopoietic stem cell transplantation for the treatment of combined immunodeficiency (CID) and explore prognostic risk factors. Methods: In this retrospective cohort study, clinical characteristics, laboratory tests and prognosis of 73 CID children who underwent allogeneic hematopoietic stem cell transplantation from February 2014 to April 2022 in the Children's Hospital of Fudan University were analyzed. Based on the subtypes of diseases, all patients were divided into severe combined immunodeficiency disease (SCID) group and other CID group. Based on the types of donors, all patients were divided into matched sibling donor group, matched unrelated donor group, unrelated cord blood group, and haploidentical donor group. Kaplan-Meier method and Log-Rank test were used to analyze the survival data. Cox regression was used to analyze prognostic factors. Results: Among the 73 patients, there were 61 (84%) males and 12 (16%) females. Fifty-five (75%) patients were SCID, and 18 (25%) patients were other CID. Donor source included 2 (3%) matched sibling donors (MSD), 3 (4%) matched unrelated donors (MUD), 64 (88%) unrelated cord blood (UCB), and 4 (5%) haploidentical donors. The age at transplant was 10.7 (5.9, 27.5) months, and the follow-up time was 36.2 (2.5, 62.9) months. The 3-year overall survival rate of 73 patients with CID was (67±6) %. No significant difference was found in the 3-year overall survival rates between patients with SCID (55 cases) and other CID (18 cases) ((64±7) % vs. (78±10) %, χ2=1.31, P=0.252). And no significant difference was found in the 3-year overall survival rates among patients who received MSD or MUD (5 cases), UCB (64 cases), and haploidentical donor (4 cases) transplant (100% vs. (66±6)% vs. (50±25) %, χ2=2.30, P=0.317). Cox regression analysis showed that the medical history of sepsis (HR=2.55, 95%CI 1.05-6.20, P=0.039) and hypoalbuminemia at transplant (HR=2.96, 95%CI 1.14-7.68, P=0.026) were independent risk factors for the prognosis of allogeneic hematopoietic stem cell transplantation in pediatric patients with CID. Conclusions: Allogeneic hematopoietic stem cell transplantation is an effective treatment for CID. The medical history of sepsis and hypoalbuminemia at transplant were risk factors for prognosis. Enhancing infection prevention and nutritional intervention before transplant can improve patient prognosis.

Visual and Electrochemical Detection of let-7a: A Tumor Suppressor and Biomarker

Let-7a, a type of low-expressed microRNAs in cancer cells, has been investigated as a promising biomarker and therapeutic target for tumor suppression. Developing simple and sensitive detection methods for let-7a is important for cancer diagnosis and treatment. In this work, the hybridization chain reaction (HCR) was initiated by let-7a via two hairpin primers (H1 and H2). After the HCR, the remaining hairpin H1 was further detected by lateral flow assay (LFA) and electrochemical impedance spectroscopy. For LFA, biotin-modified H1(bio-H1) and free H2 were used for HCR. With the decrease of let-7a concentration, the color of T line gradually increased. As for electrochemical methods, the H1'-AuNP-modified electrode was used for detection of bio-H1 based on the difference of impedance (ΔR_ct) detected without and with different concentrations of let-7a participating in the HCR. This method could detect let-7a in the range of 10.0 fM and 1.0 nM with detection limits of 4.2 fM.

Oral Metal-Organic Gel Protected Whole-Cell Biosensor for in Situ Monitoring Nitrosamines in the Gastrointestinal Tract

Nitrite, a type of food additive, has been proved convertible to genotoxic nitrosamines in the gastrointestinal tract by intestinal flora. There is no appropriate method for in situ detection of nitrosamines. Herein, plasmid-introduced Saccharomyces cerevisiae, which can respond to nitrosamine-induced DNA damage and activate pMAG1-based DNA damage repair (DDR), was designed as whole-cell biosensors (WCBs) for monitoring the in situ generated nitrosamines by a reporter gene expressing enhanced green fluorescent protein (EGFP). In order to protect the validity of WCBs (pMAG1 yeast) from the gastric acid environment, a type of metal-organic gel (MOG), coordinated by Fe³⁺ and 2,2'-thiodiacetic acid (TDA), was prepared to embed the WCBs. The MOG(Fe-TDA) is gastric acid resistant and can deliver the pMAG1 yeast to the gut without compromising the performance of pMAG1 yeast to detect in situ generated nitrosamines. The genotoxicity of nitrosamines converted from nitrite was successfully detected in the gastrointestinal tract of mice.

[Analysis of risk factors and prognosis of cytomegalovirus infection post umbilical cord blood stem cell transplantation in children with primary immunodeficiency diseases]

Objective: To investigate the risk factors and outcomes of cytomegalovirus (CMV) infection post umbilical cord blood stem cell transplantation (UCBT) in children with primary immunodeficiency diseases (PID). Methods: Clinical data of 143 PID children who received UCBT in the Children's Hospital of Fudan University from January 2015 to June 2020 were collected retrospectively. CMV-DNA in the plasma was surveilled once or twice a week within 100 days post-UCBT. According to the CMV-DNA test results, children were divided into the CMV-infected group and the CMV-uninfected group. The incidence and risk factors of CMV infection were analyzed. At 1-month post-UCBT, the absolute lymphocyte count, ratio of lymphocyte subsets and immunoglobulin levels were compared between those whose CMV infection developed 1-month later post-UCBT and those not. Mann-Whitney U test and chi-squared test were used for comparision between groups. Kaplan-Meier survival analysis was used to analyze the impact of CMV infection on survival. Results: Among 143 patients, there were 113 males and 30 females, with a age of 14 (8, 27) months at UCBT. Chronic granulomatosis disease (n=49), very-early-onset inflammatory bowel disease (n=43) and severe combined immunodefiency (n=29) were the three main kinds of PID. The rate of CMV infection was 21.7% (31/143), and the time of infection occurring was 44 (31, 49) days post-UCBT. The incidence of recurrent CMV infection was 4.2% (6/143) and refractory CMV infection was 4.9% (7/143).There was no significant difference in the first time CMV-DNA copy and peak CMV-DNA copy during treatment between the recurrent CMV infection group and the non-recurrent CMV infection group (32.8 (18.3, 63.1)×10⁶ vs. 22.5 (13.2, 31.9)×10⁶ copies/L, Z=-0.95, P=0.340;35.2 (20.2, 54.6)×10⁶ vs. 28.4 (24.1, 53.5)×10⁶copies/L, Z=-0.10, P=0.920), so were those between the refractory CMV infection group and non-refractory CMV infection group (21.8 (13.1, 32.2)×10⁶ vs. 25.9 (14.2, 12.2)×10⁶copies/L, Z=-1.04, P=0.299; 47.7 (27.9, 77.6)×10⁶ vs. 27.7 (19.7,51.8)×10⁶copies/L, Z=-1.49, P=0.137). The CMV-infected group accepted more reduced-intensity conditioning (RIC) regimen than the CMV-uninfected group (45.2% (14/31) vs. 25.0% (28/112), χ²=4.76, P<0.05). The rate of CMV-seropositive recipients and Ⅱ-Ⅳ acute graft versus host diseases (aGVHD) are significantly higher in the CMV-infected group than the CMV-uninfected group (100% (31/31) vs. 78.6% (88/112), 64.5% (20/31) vs. 26.8% (30/112), χ²=7.98,15.20, both P<0.05). The follow-up time was 31.6 (13.2, 45.9) months, CMV infection had no effect on overall survival (OS) rate (χ²=0.02, P=0.843). There was significant difference in the survival rate among three groups of refractory CMV infection, non-refractory CMV infection and the CMV-uninfected (4/7 vs.95.8% (23/24) vs. 86.6% (97/112), χ²=5.91, P=0.037), while there was no significant difference in the survival rate among three groups of recurrent CMV infection, non-recurrent CMV infection and the CMV-uninfected (5/6 vs. 88.0% (22/25) vs. 86.6% (97/112), χ²=0.43, P=0.896). Children who developed CMV infection after 30 days post-UCBT had lower absolute count and rate of CD4⁺ T cells and immunoglobulin G (IgG) level than those in the CMV-uninfected group (124.1 (81.5, 167.6) ×10⁶ vs. 175.5 (108.3, 257.2) ×10⁶/L, 0.240 (0.164, 0.404) vs. 0.376 (0.222, 0.469), 9.3 (6.2, 14.7) vs. 13.6 (10.7, 16.4) g/L, Z=-2.48, -2.12,-2.47, all P<0.05), but have higher rate of CD8⁺T cells than those in CMV-uninfected group (0.418 (0.281, 0.624) vs. 0.249 (0.154, 0.434), Z=-2.56, P=0.010). Conclusions: RIC regimen, grade Ⅱ-Ⅳ aGVHD and CMV-seropositive recipients are the main risk factors associated with CMV infection in PID patients post-UCBT. Survival rate of children with refractory CMV infection after UCBT is reduced. Immune reconstitution in children after UCBT should be regularly monitored, and frequency of CMV-DNA monitoring should be increased for children with delayed immune reconstitution.

[Mid-term efficacy of China Net Childhood Lymphoma-mature B-cell lymphoma 2017 regimen in the treatment of pediatric Burkitt lymphoma]

Objective: To analyze the clinical characteristics of children with Burkitt lymphoma (BL) and to summarize the mid-term efficacy of China Net Childhood Lymphoma-mature B-cell lymphoma 2017 (CNCL-B-NHL-2017) regimen. Methods: Clinical features of 436 BL patients who were ≤18 years old and treated with the CNCL-B-NHL-2017 regimen from May 2017 to April 2021 were analyzed retrospectively. Clinical characteristics of patients at disease onset were analyzed and the therapeutic effects of patients with different clinical stages and risk groups were compared. Survival analysis was performed by Kaplan-Meier method, and Cox regression was used to identify the prognostic factors. Results: Among 436 patients, there were 368 (84.4%) males and 68 (15.6%) females, the age of disease onset was 6.0 (4.0, 9.0) years old. According to the St. Jude staging system, there were 4 patients (0.9%) with stage Ⅰ, 30 patients (6.9%) with stage Ⅱ, 217 patients (49.8%) with stage Ⅲ, and 185 patients (42.4%) with stage Ⅳ. All patients were stratified into following risk groups: group A (n=1, 0.2%), group B1 (n=46, 10.6%), group B2 (n=19, 4.4%), group C1 (n=285, 65.4%), group C2 (n=85, 19.5%). Sixty-three patients (14.4%) were treated with chemotherapy only and 373 patients (85.6%) were treated with chemotherapy combined with rituximab. Twenty-one patients (4.8%) suffered from progressive disease, 3 patients (0.7%) relapsed, and 13 patients (3.0%) died of treatment-related complications. The follow-up time of all patients was 24.0 (13.0, 35.0) months, the 2-year event free survival (EFS) rate of all patients was (90.9±1.4) %. The 2-year EFS rates of group A, B1, B2, C1 and C2 were 100.0%, 100.0%, (94.7±5.1) %, (90.7±1.7) % and (85.9±4.0) %, respectively. The 2-year EFS rates was higher in group A, B1, and B2 than those in group C1 (χ²=4.16, P=0.041) and group C2 (χ²=7.21, P=0.007). The 2-year EFS rates of the patients treated with chemotherapy alone and those treated with chemotherapy combined with rituximab were (79.3±5.1)% and (92.9±1.4)% (χ²=14.23, P<0.001) respectively. Multivariate analysis showed that stage Ⅳ (including leukemia stage), serum lactate dehydrogenase (LDH)>4-fold normal value, and with residual tumor in the mid-term evaluation were risk factors for poor prognosis (HR=1.38,1.23,8.52,95%CI 1.05-1.82,1.05-1.43,3.96-18.30). Conclusions: The CNCL-B-NHL-2017 regimen show significant effect in the treatment of pediatric BL. The combination of rituximab improve the efficacy further.

Lanthanide Complexes for Tumor Diagnosis and Therapy by Targeting Sialic Acid

Sialic acid (SA) is overexpressed on cell membranes of tumor cells, and increased serum SA concentration has been observed in tumor-bearing patients. Herein, a series of lanthanide-containing bimetallic complexes (TDA-M-Lns) for targeting SA were prepared via coordination among luminescent lanthanide ions (Ln³⁺ = Tb³⁺, Eu³⁺, Dy³⁺, or Sm³⁺), metal ion quenchers (M²⁺ = Cu²⁺ or Co²⁺), and the organic ligand 2,2'-thiodiacetic acid (TDA). SA can competitively coordinate with Ln³⁺, resulting in the "signal-on" of the Ln³⁺. Therefore, the TDA-M-Lns can be simply used for cost-saving detection of SA in the blood samples. Among the TDA-M-Lns, TDA-Co-Eu showed the highest sensitivity to detect SA in the blood of tumor-bearing mice. Furthermore, the TDA-Co-Eu was successfully used to target SA and deposit Eu³⁺ on the surfaces of tumor cells for the inhibition of tumor cell growth and migration. The therapeutic effect of TDA-Co-Eu on a Balb/c mouse liver tumor model was evaluated. It was proved that TDA-Co-Eu can be applied for SA detection as well as for inhibiting tumor growth.

[Modified mattress inversion suturing with double barbed sutures used for totally laparoscopic esophagojejunostomy overlap anastomosis after radical total gastrectomy]

Objective: To explore the advantages and safety of a modified mattress inversion suturing using double barbed sutures compared with the traditional overlap method in totally laparoscopic esophagojejunostomy overlap anastomosis. Methods: A retrospective cohort study was conducted. The inclusion criteria were as follows: (1) patients were aged 18 - 80 years old; (2) adenocarcinoma was preoperatively confirmed by pathological analysis; (3) patients had undergone a complete laparoscopic radical total gastrectomy; (4) patients had undergone esophagojejunostomy using the overlap method; (5) patients received a grade of I-III on the American Society of Anesthesiologists physical status classification system; (6) patients' complete follow-up data had been collected. Patients with a history of other malignant tumors, multi-origin tumors, emergency surgery, non-R0 radical resection or distant metastasis were excluded. The clinical data of 89 gastric cancer patients who underwent total laparoscopic radical total gastrectomy in the Department of Gastrointestinal Surgery in the Sixth Affiliated Hospital of Sun Yat-sen University from January 2019 to December 2020 were collected. These patients were grouped according to the esophagojejunostomy method used. Of 89 patients, 32 received modified mattress inversion suturing with double barbed sutures to close the common opening of esophagojejunostomy (the modified anastomosis group), while 57 received traditional overlap anastomosis in which the common opening was closed by barbed suture (the traditional anastomosis group). The operation conditions (incision length, conversion to laparotomy, duration of esophagojejunostomy) and postoperative recovery (time to commencement of a liquid diet, duration of postoperative hospital stay, anastomotic leakage, anastomotic stenosis, and anastomotic bleeding) were compared between the two groups. Results: There was no significant difference in the baseline data of the two groups for any parameter (all P>0.05). All patients received complete laparoscopic radical gastrectomy without conversion to laparotomy. There were no significant differences in the length of the median incision, the proportion of food intake on the first day after surgery, or in the incidence of anastomotic complications such as anastomotic leakage, anastomotic stenosis, and anastomotic bleeding between the two groups (P>0.05). Compared with the traditional anastomosis group, patients in the modified anastomosis group had shorter anastomosis time [26 (19-62) minutes vs. 36 (20-50) minutes, Z=-2.546, P=0.011] and postoperative hospital stay [7 (6-12) days vs. 9 (7-42) days, Z=-4.202, P<0.001]. The differences were statistically significant (all P<0.05). In a subgroup analysis of tumor TNM stage III, Siewert type II and neoadjuvant chemotherapy patients, there was no significant difference in the incidence of anastomotic complications between the modified group and the traditional group. However, the postoperative hospital stay duration in the modified anastomosis group was less than in the traditional anastomosis group. The duration of anastomosis in Siewert type II patients was also shorter in the modified anastomosis group than in the traditional anastomosis group [26 (19-62) minutes vs. 38 (21-50) minutes, Z=-2.105, P=0.035], and the difference was statistically significant (all P<0.05). Conclusion: Complete laparoscopic esophagojejunostomy using modified mattress inversion suturing with double barbed sutures is a safe and feasible anastomosis method to close the common opening of esophagojejunostomy, with shorter operation time, faster postoperative recovery and shorter hospital stay than the traditional method.

Enzyme-immobilized metal-organic frameworks: From preparation to application

As a class of widely used biocatalysts, enzymes possess advantages including high catalytic efficiency, strong specificity and mild reaction condition. However, most free enzymes have high requirements on the reaction environment and are easy to deactivate. Immobilization of enzymes on nanomaterial-based substrates is a good way to solve this problem. Metal-organic framework (MOFs), with ultra-high specific surface area and adjustable porosity, can provide a large space to carry enzymes. And the tightly surrounded protective layer of MOFs can stabilize the enzyme structure to a great extent. In addition, the unique porous network structure enables selective mass transfer of substrates and facilitates catalytic processes. Therefore, these enzyme-immobilized MOFs have been widely used in various research fields, such as molecule/biomolecule sensing and imaging, disease treatment, energy and environment protection. In this review, the preparation strategies and applications of enzymes-immobilized MOFs are illustrated and the prospects and current challenges are discussed.

Fluorescent intracellular imaging of reactive oxygen species and pH levels moderated by a hydrogenase mimic in living cells

The catalytic generation of H₂ in living cells provides a method for antioxidant therapy. In this study, an [FeFe]-hydrogenase mimic [Ru + Fe₂S₂@F127(80)] was synthesized by self-assembling polymeric pluronic F-127, catalytic [Fe₂S₂] sites, and photosensitizer Ru(bpy)₃²⁺. Under blue light irradiation, hydrated protons were photochemically reduced to H₂, which increased the local pH in living cells (HeLa cells). The generated H₂ was subsequently used as an antioxidant to decrease reactive oxygen species (ROS) levels in living cells (HEK 293T, HepG2, MCF-7, and HeLa cells). Our findings revealed that the proliferation of HEK 293T cells increased by a factor of about six times, relative to that of other cells (HepG2, MCF-7, and HeLa cells). Intracellular ROS and pH levels were then monitored using fluorescent cell imaging. Our study showed that cell imaging can be used to evaluate the ability of Ru + Fe₂S₂@F127 to eliminate oxidative stress and prevent ROS-related diseases.

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An [FeFe]-hydrogenase mimic was synthesized for H₂ photogeneration.

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The catalytic generation of H₂ was evaluated in HEK 293T cells.

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The H₂ generated by Ru + Fe₂S₂@F127(80) was able to decrease ROS levels.

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Light irradiation of Ru + Fe₂S₂@F127(80) led to an increase in intracellular pH.

[Analysis of clinical and genetic characteristics of epilepsy associated with chromosome 16p11.2 microdeletion]

Objective: To investigate the clinical and genetic characteristics of epilepsy associated with chromosome 16p11.2 microdeletion. Methods: The patients (n=10) with 16p11.2 microdeletion found in children with epilepsy treated in Beijing Children's Hospital Affiliated to Capital Medical University from January 2018 to January 2021 were collected. The clinical manifestations, gene variations and prognosis were analyzed retrospectively. Results: A total of 10 children's data were collected, including 5 male and 5 female. The onset age of epilepsy was 4.5 (4.1,5.0) months. Regarding the seizure types, 7 cases had focal seizures with secondary generalization, 2 cases had generalized seizures, and 1 case had tonic seizures and spasms. Nine cases had cluster seizure attacks and 3 cases had status epilepticus. Seven cases had focal or multifocal epileptiform discharges in interictal electroencephalogram (EEG), 3 cases had borderline or normal EEG. Brain magnetic resonance imaging showed polymicrogyria in 1 case, paraventricular leukomalacia in 1 case, delayed myelination of white matter in 3 cases, and no obvious abnormalities in the other 5 cases. The patients were followed up for 0.5-3.5 years, with 1-3 kinds of antiepileptic drugs taken orally. The case with polymicrogyria still had seizures, however the other 9 cases had seizures controlled. The age of the last seizure attack was 8 (6, 12) months. There were 6 cases with mental and motor developmental delay before epilepsy onset. During the follow-up, 7 cases were retarded to varying degrees, while 3 cases had normal development. Regarding the genetic detection methods, 7 cases underwent whole exome sequencing, 2 cases underwent whole genome copy number variation detection, and 1 case underwent whole genome sequencing. The length of the 16p11.2 deletion in 10 cases ranged from 525 to 951 kb, and all contained the PRRT2 gene intact. Six cases were de novo variants, 1 case was inherited from the mother who had a history of convulsions in early childhood, and the source of variant was not verified in 3 cases, none of whose parents had relevant phenotype. Conclusions: The epilepsy associated with 16p11.2 microdeletion is mainly induced by the heterozygous deletion of PRRT2 gene in this region, however the phenotype is usually severe, and often combined with developmental and epileptic encephalopathy. Detection of copy number variation should be emphasized in children whose etiology is considered genetic but second-generation sequencing result is negative.

[Risk factors of pancreatitis after percutaneous transhepatic biliary drainage in patients with pancreatic cancer and obstructive jaundice]

Objective: To explore the risk factors and preventive strategies of pancreatitis after percutaneous transhepatic biliary drainage (PTBD) in patients with pancreatic cancer and obstructive jaundice. Methods: A total of 241 patients were retrospectively analyzed from May 2001 to October 2014 in Tianjin Medical University Cancer Institute and Hospital. The possibly correlated 9 factors were analyzed, including gender, age, hemoglobin level, total bilirubin level, degree of pancreatic duct dilatation, degree of pancreatic atrophy, degree of biliary stenosis, the pancreatic duct visualization, and drainage mode. Results: Univariate analysis suggested that pancreatic duct dilatation, pancreatic atrophy, visualized pancreatic duct and drainage mode were associated with the incidence of pancreatitis after PTBD (P<0.05). Logistic regression analysis showed that visualization of pancreatic duct (OR=6.33) was a risk factor for pancreatitis, while pancreatic duct dilatation (OR=0.14), pancreatic atrophy (OR=0.12) and external drainage (OR=0.11) were protective factors for pancreatitis. Conclusion: In pateints with pancreatic cancer and obstructive jaundice, pancreatic duct dilatation and pancreatic atrophy predict low risk of pancreatitis after PTBD,while intraoperative pancreatic duct visualization and internal or external drainage may increase the incidence of postoperative pancreatitis.

Cancer drug resistance related microRNAs: recent advances in detection methods

MiRNAs are related to cancer drug resistance through various mechanisms. The advanced detection methods for the miRNAs are reviewed.

Surface functionalized biomimetic bioreactors enable the targeted starvation-chemotherapy to glioma

Altering the glucose supply and the metabolic pathways would be an intriguing strategy in starvation therapy toward cancers. Nevertheless, starvation therapy alone could be inadequate to eliminate tumor cells completely. Herein, a multifunctional bioreactor was fabricated for synergistic starvation-chemotherapy through embedding glucose oxidase (GOx) and doxorubicin (DOX) in the tumor targeting ligands (RGD) modified red blood cell membrane camouflaged metal-organic framework (MOF) nanoparticle (denoted as RGD-mGZD). Owing to the remarkable biointerfacing property, the designed RGD-mGZD could not only possess enhanced blood retention time inherited from red blood cells, but also preferentially target the tumor site after the modification with RGD peptide. Once the bioreactor reached the desired region, GOx promptly consumed the intratumoral glucose and oxygen to starve cancer cells for robust starvation therapy. More importantly, the aggravated acidic microenvironment at the tumor region was found to induce the decomposition of the MOF structure, thus triggering the release of DOX for reinforced chemotherapy. This bioreactor would further prompt the development of synergistic patterns toward cancer treatment in a spatiotemporally controlled manner.

Anti-cancer adjuvant drug screening via epithelial-mesenchymal transition-related aptamer probe

Epithelial-mesenchymal transition (EMT) is implicated in the pathological processes of cancer metastasis and drug resistance. Anti-cancer drugs may also potentially lead to EMT, resulting in their reduced therapeutic effect. Therefore, the combination of these anti-cancer drugs with anti-EMT agents has been promoted in clinic. Screening anti-EMT drugs and evaluation of EMT process are highly dependent on EMT biomarkers on cell membrane. At present, the detection of EMT biomarker is mainly by Western blot method, which is time-consuming and complicated. In this work, for effectively screening anti-EMT drugs by evaluation of the EMT process, a type of aptamer probe based on aggregation-induced emission (AIE) was designed. The aptamer SYL3C was employed to target the EMT biomarker EpCAM on cell membrane. Two fluorophores, FAM and tetraphenylethene (TPE, an AIE dye), were modified at the two ends of SYL3C, respectively. This aptamer probe (TPE-SYL3C-FAM) can monitor the EpCAM expression, which can be recovered by anti-EMT drugs. By observation of the change in TPE emission intensity, the anti-EMT effect of drugs can be evaluated. The FAM emission was used as internal reference to reduce environmental interferences. This probe can be potentially used to screen anti-EMT agents as anti-cancer adjuvant drugs with high throughput.

Circulating tumor DNA analysis for tumor diagnosis

Tumor is a kind of abnormal organism generated by the proliferation and differentiation of cells in the body under the action of various initiating and promoting factors, which seriously threatens human life and health. Tumorigenesis is a gradual process that involves multistage reactions and the accumulation of mutations. Gene mutation usually occurs during tumorigenesis, and can be used for tumor diagnosis. Early diagnosis is the most effective way to improve the cure rate and reduce the mortality rate. Among the peripheral blood circulating tumor DNA (ctDNA), gene mutation in keeping with tumor cells can be detected, which can potentially replace tumor tissue section for early diagnosis. It has been considered as a liquid biopsy marker with good clinical application prospect. However, the high fragmentation and low concentration of ctDNA in blood result in the difficulty of tumor stage determination. Therefore, high sensitive and specific mutation detection methods have been developed to detect trace mutant ctDNA. At present, the approaches include digital PCR (dPCR), Bead, Emulsion, Amplification and Magnetic (BEAMing), Next Generation Sequencing (NGS), Amplification Refractory Mutation System (ARMS), etc. In this paper, the principle, characteristics, latest progress and application prospects of these methods are reviewed, which will facilitate researchers to choose appropriate ctDNA detection approaches.

Multiple adsorption properties of aptamers on metal-organic frameworks for nucleic acid assay

Enrichment and detection of circulating free nucleic acids in biological samples have gained great attention for disease diagnosis or prognostic evaluation. Nanoscale metal-organic frameworks (NMOFs) have been used for aptamer-based nucleic acid sensing. In this work, different NMOFs, including ZIF-8, MIL-88, MIL-100, MIL-101, as well as Eu-TDA and Tb-TDA [prepared by the coordination of 2,2'-thiodiacetic acid (TDA) and Eu³⁺ or Tb³⁺], were investigated in nucleic acid sensing by employing their aptamer adsorption ability and fluorescence quenching capacity for the labeled dyes. Two types of dye aptamer, FAM-labeled aptamer (FAM-Ap) and TexasRedaptamer (TexasRed-Ap) were designed, and their adsorption properties on NMOFs-were compared. It was found that the TexasRed-Ap can be well used for nucleic acid (miR-21) extraction and sensing by linking with a pH-responsive nucleotide chain (TexasRed-Ap-pH) or with an additional random chain ssDNA-1' (TexasRed-Ap-a). After interacted with the target miR-21 in biosamples, the TexasRed-dsDNA + NMOFs composites can be collected, and the formed TexasRed-dsDNA can be released by changing pH value or addition of ssDNA-1, which is matched with ssDNA-1'. A linear relationship from 0.1 to 200 pM for miR-21 detection was obtained. The results show that the NMOFs can be used as promising platforms for nucleic acid extraction and fluorescent sensing.

Development of biological metal-organic frameworks designed for biomedical applications: from bio-sensing/bio-imaging to disease treatment

Metal-organic frameworks (MOFs) are built using various organic ligands and metal ions (or clusters). With properties of high porosity, tunable chemical composition, and potential for post-synthetic modification, they have been applied in biomedicine, especially in bio-sensing, bio-imaging, and drug delivery. Since organic ligands and metal centers (ions or clusters) in the structure of MOFs can directly influence the property, function, and performance of MOFs, strict screening of organic ligands and metal centers is necessary. Especially, to improve the application of MOFs in the field of biomedicine, biocompatible organic ligands with low toxicity are desirable. In recent years, biological metal-organic frameworks (bio-MOFs) with ideal biocompatibility and diverse functionality have attracted wide attention. Endogenous biomolecules, including nucleobases, amino acids, peptides, proteins, porphyrins and saccharides, are employed as frameworks for MOF construction. These biological ligands coordinate with diverse metal centers in different ways, leading to the structural diversity of bio-MOFs. In this review, we summarize the organic ligand selectivity in constructing different types of bio-MOFs and their influence in biomedical applications with attractive new functions.

Colorable Zeolitic Imidazolate Frameworks for Colorimetric Detection of Biomolecules

We report a series of colorable zeolitic imidazolate framework (ZIF)-based nanomaterials prepared by encapsulating starches (amylopectin, dextrin, or amylose) or tannic acid in the frameworks of ZIFs and first applied them in colorimetric assay of microRNA/DNA by adding I₂/KI or FeCl₃ solutions as chromogenic reagents. We found that iodine molecules can lead to rapid degradation of the ZIF-8 framework, while ZIF-90 remains stable. Therefore, ZIF-90 was selected for encapsulating the starches or tannic acid, and then assembled with polyethylenimine (PEI) and aptamers of microRNA/DNA. After interacting with the target microRNA/DNA, the aptamers (Ap) move away from the surface of the prepared Ap-starch@ZIF-90 or Ap-tan@ZIF-90, and the I₂/KI or FeCl₃ solution is added into the system to interact the starches (amylopectin, dextrin, or amylose) or tannic acid to generate different colors. According to the absorbance spectra, good linear correlations between the logarithm of absorbance intensity and the concentration of microRNA (1-180 nM) can be observed, and the naked eye can distinguish the change from ∼60 to ∼180 nM with a concentration gradient of 20 nM. A similar colorimetric assay ability for pathogenic bacteria can also be realized by detecting the gene fragments IS200 and eaeA. The detection limits can be potentially optimized by changing the amount of adsorbed PEI and aptamers on the surface of Ap-starch@ZIF-90 (or Ap-tan@ZIF-90) nanoparticles. This method could be a promising alternative for simple and cost-effective assay of microRNA/DNA.

Fluorescence resonance energy transfer (FRET)-based nanoarchitecture for monitoring deubiquitinating enzyme activity

A novel nanoarchitecture (MSN-Tb-UbR) was prepared by modifying rhodamine B-labelled Ubs (Ub-Rs) on the surface of mesoporous silica nanoparticles (MSNs) loaded with Tb³⁺-complexes. The MSN-Tb-UbR exhibits ratiometric sensing ability for DUB (UCH-L1) with good sensitivity and selectivity.

[Expression of p-AKT and p-mTOR in pediatric Burkitt lymphoma and their correlation with prognosis]

Objective: To evaluate the expression of p-AKT and p-mTOR, the key proteins in PI3K/AKT/mTOR pathway in pediatric Burkitt lymphoma (BL), and to investigate the clinical and prognostic significance. Methods: Fifty-eight cases of pediatric BL and thirty cases of reactive hyperplastic lymphadenitis (RH) were collected at Children's Hospital of Fudan University from September 2011 to July 2018. Paraffin sections of tissues were immune stained for p-AKT and p-mTOR, and the expression was assessed and correlated with the clinical features and prognosis. Results: A total of 58 cases were diagnosed and 6 cases lost the follow-up. Of the remaining 52 BL patients including 43 males and 9 females, the median age was 5 years (range: 2 to 14 years). Regarding to the correlation between the two biomarkers, Spearman test showed that p-mTOR was positively associated with the expression of p-AKT (r=0.759, P<0.001). Of all BL patients, the positive rates of p-AKT and p-mTOR were 62.1% (36/58) and 60.3%(35/58) respectively, both significantly higher than control group (P=0.011, P=0.035 respectively). The presence of p-AKT was significantly associated with higher lactate dehydrogenase (LDH≥573 IU/L) level in patients of the disease (P=0.006), while p-mTOR was increased both in the higher LDH and lower ratio of albumin to globulin (A/G) group (P=0.006, P=0.034 respectively). Expression of p-AKT and p-mTOR did not show any statistical correlation with sex, age, St.jude stage, tumor size, B-symptom present or not, number of extra-nodal sites or international prognostic index (IPI) (P>0.05). Fifty-two patients had a median follow-up of 40 months (range: 5-87 months). Univariate analysis showed that p-AKT expression was significant in predicting both inferior OS (5-year estimate, 72.7% vs. 94.7%, χ(2)=4.123, P=0.042) and PFS (5-year estimate, 66.7% vs. 94.7%, χ(2)=5.822, P=0.016). The 5-year OS rate was 71.0% (22/31) for the p-mTOR positive cohort of patients compared to 95.2% (17/21) for p-mTOR negative group (χ(2)=4.881, P=0.027); however, there was no statistical significance in 5-year PFS rate (P>0.05). Especially, the 5-year OS and PFS rate of p-AKT/p-mTOR double-positive group were significantly lower than negative control group (including absence of single p-AKT or p-mTOR expression, and absence of both) (OS: 69.0% vs. 95.7%, χ(2)=6.285, P=0.012; PFS: 65.5% vs. 91.3%, χ(2)=5.405, P=0.020). The results of multivariate COX proportional risk regression analysis indicated that p-AKT/p-mTOR double-positive, higher LDH and IPI score 3-5 were independent prognostic factors for both OS and PFS, and the bulky tumor (>10 cm) for PFS of pediatric BL. Conclusion: The expression of p-AKT and p-mTOR may be a potential reference for diagnosis and the independent prognostic indicators of pediatric BL.

[Short-term outcomes and prognosis of palliative surgery for malignant bowel obstruction caused by peritoneal metastasis of colorectal cancer]

Objective: To explore the short-term efficacy and prognosis of palliative surgical treatment for malignant bowel obstruction (MBO) caused by peritoneal metastasis of colorectal cancer (mCRC). Methods: A retrospective cohort study was conducted. The inclusion criteria for patients were as follows: (1) primary colorectal cancer; (2) massive peritoneal metastasis; (3)obstructive site located below Treitz ligament by imaging; (4) obstruction refractory to conservative treatment; (5) estimated rese survival time more than 2 months; (6) patients and their families had strong willingness for operation; (7) surgical treatment included stoma/bypass and debulking surgery. In accordance with the above criteria, clinicopathological data of 46 patients undergoing palliative surgery at Peking University Gastrointestinal Cancer Center, Unit III from January 2016 to October 2018 were retrospectively collected. Postoperative symptomatic relief rate, morbidity of complication within 30 days, complication classification (Clavien-Dindo classification), mortality and survival after operation were analyzed. Kaplan-Meier method was used to evaluate survival and Cox regression analysis was used to identify prognostic factors. Results: Among 46 patients, 30 were male and 16 were female with median age of 63 (19-87) years; 23 patients received stoma/bypass surgery (stoma/bypass group), and 23 cases received tumor debulking surgery (debulking group). The overall symptom relief rate was 76.1% (35/46), while symptom relief rate in the debulking group was 91.3% (21/23), which was significantly higher than 60.9% (14/23) in the stoma/bypass group (χ(2)=4.301, P=0.038). Postoperative complications occurred in 25 patients. The complication rate was 52.2% (12/23) in the debulking group and 56.5% (13/23) in the stoma/bypass group, without statistically significant difference (χ(2)=0.088, P=0.767). Morbidity of complication beyond grade III was 8.7% (2/23) and 13.0% (3/23) in the debulking group and stoma/bypass group respectively, without statistically significant difference (χ(2)=0.224, P=0.636). Four patients died within 30 days after operation, 2 (8.7%) in each group. Twenty-four patients underwent 1-8 cycles of chemotherapy ± targeting therapy (regimens: CapeOX ± Bevacizumab, FOLFOX/FOLFIRI ± Bevacizumab/Cetuximab), including 10 cases in the stoma/bypass group and 14 cases in the debulking group. Two patients of debulking group received postoperative radiotherapy and chemotherapy (50.6 Gy/22 f, with concurrent oral capecitabine). Till the last follow up of April 2019, 34 patients died (34/46, 73.9%) with a median overall survival time of 6.4 months, and the 6-month and 1-year survival rate was 54.5% and 29.2% respectively. The median survival time in the debulking group was significantly longer than that in the stoma/bypass group (11.5 months vs. 5.2 months, χ(2)=5.117, P=0.024). The median survival time of the 35 patients with symptomatic relief after operation was significant longer than that of 11 patients without relief (7.1 months vs 5.1 months, χ(2)=3.844, P=0.050). Multivariate analysis showed stoma/bypass surgery (HR=2.917, 95%CI:1.357-6.269, P=0.006) and greater omental metastasis (HR=4.060, 95%CI:1.419-11.617, P=0.009) were independent risk factors associated with prognosis of patients with MBO caused by peritoneal mCRC. Conclusions: For patients of MBO caused by peritoneal mCRC, tumor debulking surgery may achieve higher symptom relief rate and prolong survival. Greater omental metastasis indicates poor prognosis.

[Research on knowledge status and relevant factors of breastfeeding among medical staff in China based on network platform]

From August 1(st) to 7(th), 2017, the breastfeeding knowledge of medical staff were collected from 52 medical health institutions in 29 provinces through a network system. A total of 35 243 questionnaires were included in the study to analyze the current status of breastfeeding knowledge and related factors. The qualified rate of breastfeeding knowledge questionnaires for medical staff in this study was 75.3% (26 546/35 243). Compared with those in the eastern region and those who were mothers, the qualified rate of breastfeeding knowledge of medical staff in the central region or the western region and medical staff who were fathers or expectant parents was lower, with OR (95%CI) values about 0.71 (0.67-0.75), 0.66 (0.61-0.72), 0.63 (0.55-0.72) and 0.87 (0.80-0.95), respectively. Compared with those attaining high school education or below and those with children aged<1 month, the qualified rate of breastfeeding knowledge was higher in medical staff with bachelor's degree, graduate degree or above, and with children aged 1-5, 6-23 and ≥24 months, with OR (95%CI) values about 1.92 (1.80-2.05), 2.16 (1.94-2.42), 2.28 (1.93-2.70), 2.41 (2.06-2.83) and 1.99 (1.72-2.32), respectively.

Regulating Fluorescent Aptamer-Sensing Behavior of Zeolitic Imidazolate Framework (ZIF-8) Platform via Lanthanide Ion Doping

Nanoscale metal-organic frameworks (NMOFs) have been proved to be effective quenching platforms for fluorescent detection of DNA via fluorophore-quencher pairs. Zeolitic imidazolate framework-8 (ZIF-8) is one type of the most promising NMOFs because of its excellent biocompatibility and easy preparation. However, ZIF-8 is rarely used as platforms for fluorescence sensing of DNA because of its bad fluorescence quenching property. In this study, lanthanide ions were doped into ZIF-8 to regulate its fluorescence quenching behavior. The La³⁺ doped ZIF-8 (ZIF-8-La) showed the best quenching efficiency on dye-labeled DNA. The signal-to-background ratio was around 3 times higher than ZIF-8. Furthermore, a core-shell La³⁺-doped ZIF-8 (CS-ZIF-8-La) was designed to modify more La³⁺ on the surface of ZIF-8. Compared with ZIF-8-La, the CS-ZIF-8-La exhibited the same fluorescence sensing behavior toward positive-dye-labeled DNA, but showed completely contrary quenching property on the negative-dye-labeled DNA. On the basis of this phenomenon, CS-ZIF-8-La was successfully used as quenching platform for designing a ratiometric sensor for DNA and microRNA.

[Genetic screening in early diagnosis of neonatal WAS gene-related disorders]

Objective: To explore the clinical value of genetic screening for early identification of WAS gene-related disorders in newborns. Methods: This was a retrospective study. Neonatal Genome Project from Children's Hospital of Fudan University collected 5 800 high-risk newborns in the neonatal intensive care unit to study the patients' genetic causes using high-throughput sequencing from January 2016 to December 2017. Eleven newborns (all were boys) with pathogenic or likely pathogenic variants in WAS gene were enrolled. Data of clinical characteristics,gene variants and genotype-phenotype correlation were collected and summarized. Results: Eleven patients included 5 cases with Wiskott-Aldrich syndrome (WAS) and 6 cases with X-linked thrombocytopenia (XLT).Two patients with WAS developed clinical manifestations in the early neonatal period,and 3 patients in 5-8 weeks after birth. Three neonates with XLT were hospitalized for other diseases in the first place.Their platelet count was found to be reduced after admission to hospital, and diagnosis was made after genetic testing. Eleven pathogenic or likely pathogenic variants in WAS gene were identified. Among them, 7 were first reported in this study, including 2 frame shift variants c.138delG and c.388_390del, 4 splicing variants c.1453+1G>A,c.734+1G>C,c.135G>A and c.1453+3G>C, and 1 missense variant c.1118C>T. The other 4 reported variants were c.777+1G>A,c.107_108delTT, c.436delC and c.1509_*3delAGTG. Conclusions: The clinical features of WAS gene-related disorders in neonatal period lack specificity. Genetic screening in newborns plays an important role in the early diagnosis of diseases and provides providing evidence for the early intervention.

Fluorescent Disulfide-functional Coordination Polymers for Sensitive Detection of Hydrogen Peroxide

A new type of fluorescent coordination polymer (NCP_Cd) based on disulfide carboxylate ligand was prepared by using one-pot synthesis for sensitive detection of reactive oxygen species (ROS). With the reaction between NCP_Cd and ROS, the morphology of the NCP_Cd was transformed from nanorods to hexagon particles, then broken into nano-fragments. Meanwhile, the fluorescence of NCP_Cd (at 421 nm) was quenched accordingly. For designing the highly sensitive probe for ROS, Rhodamine 6G (R6G) was doped in NCP_Cd. In the presence of ROS, the fluorescence of NCP_Cd moiety at 421 nm was quenched, but the R6G moiety was released from the broken nanorods and the fluorescence at 555 nm from R6G moiety was recovered. The R6G doped NCP_Cd (NCP_Cd-R) can be used as a highly sensitive and selective probe for hydrogen peroxide (H₂O₂) with detection limit of 12.4 nM. Moreover, the NCP_Cd-R was further extended to the glucose sensing combined with glucose oxidase (GOx) to oxidate glucose and generate H₂O₂, demonstrating the potential for practical applications.

Mitochondria: promising organelle targets for cancer diagnosis and treatment

Mitochondrial-mediated tumor monitoring provides a new perspective on mitochondria-based therapy.

[Role of maternal drug use and environmental exposure during pregnancy and delivery pattern in allergic infants and toddlers]

Objective: To understand correlation between maternal drug use and environmental exposure during pregnancy and delivery pattern and allergy in infants and toddlers, and provide theoretical bases for the early prevention and intervention of infantile allergies. Methods: Case control study based on cross-sectional investigation was conducted. Thirty-three cities were selected in China. Randomly cluster sampling method was used to select a community in each city as the study sample, the women with infants aged 0-24 months were interviewed in the form of face-to-face questionnaire survey. Infants and toddlers were divided into two groups: case group, including 2 113 children who had allergic symptoms and were diagnosed with allergic disease, and control group, including 6 303 children who never had symptoms of allergic disease. Results: Children whose parents had allergic disease histories were more likely to have allergic disease (OR=3.950) compared with the children whose mother or father had allergic disease histories (OR=2.277). Maternal use of antibiotics (OR=1.396), disinfector exposure (OR=1.386), smoking exposure (OR=1.301) during pregnancy and cesarean delivery (OR=1.255) were risk factors for allergic disease in infants and toddlers, the differences were significant (P<0.05). Conclusion: It is essential to conduct primary prevention of infant allergy during pregnancy, and it is necessary to avoid unnecessary cesarean delivery and irrational antibiotic use, disinfector and smoking exposures during pregnancy.

[Percentile curves on growth among breastfed 1-4 year olds in 8 urban areas]

Objective: To construct the growth percentile curves of weight-, length/height-, head circumference and BMI for 1 to 4 year-olds who had been breastfed in urban areas. Methods: Data was from the longitudinal study on 1 025 breastfed children aged 1 to 4 years, in 8 urban areas during 2008-2012. MLwiN2.25 was selected to construct the multi-level models of weight-for-age,length for-age, head circumference-for-age and BMI-for-age. The models included many growth relevant factors including gender, age, family and social demographic characteristics, perinatal factors, parent biological characteristics, dietary patterns and diseases of childen. Based on these models, predicted values (P(3), P(15), P(50), P(85), P(97)) were estimated to fit the percentiles reference curves. Results: The percentiles reference curves of weight-, length/height, head circumferenceand BMI-for-age for the 1-4 year-olds who had been breastfed in the urban areas were developed. Differences of all the indicators between boys and girls were statistically significant (P<0.001). Weight, length/height, head circumference and BMI were higher in boys than those in girls, with an average differences as 0.56-0.76 kg, 0.89-1.12 cm, 0.64-0.91 cm and 0.31-0.52 kg/m(2). Conclusion: The percentiles reference curves on growth, constructed by the longitudinal observational data and scientific method, were important in reflecting the development of breastfed children in urban areas.

Osteoblast differentiation of rabbit adipose-derived stem cells by polyethylenimine-mediated BMP-2 gene transfection in vitro

The aim of this study was to examine the efficiency of polyethylenimine-mediated transfection of the human bone morphogenetic protein-2 (BMP-2) gene into rabbit adipose-derived stem cells (ADSCs), and its effect on osteoblast differentiation. Adipose tissue was isolated from the necks of adult Japanese white rabbits and cultured in vitro to obtain ADSCs. Gene delivery of BMP-2 was mediated by polyethylenimine and stable transformants were selected by G-418. The expression of BMP-2 mRNA was confirmed by reverse transcription-polymerase chain reaction, and of the BMP-2 protein by ELISA. Osteocalcin and collagen type I were detected by western blot and by an alkaline phosphatase kit. Alizarin red S stain was also utilized to examine osteogenesis. The non-transfected group was considered as a control. In this study, we successfully derived ADSCs from rabbit adipose tissue. Through passages 3-6, the expression of CD29 and CD44 gradually increased, whereas the expression of CD34 and CD45 gradually decreased. Both mRNA and protein expression of BMP-2 were confirmed following polyethylenimine-mediated BMP-2 gene delivery. In addition, the expression of alkaline phosphatase, osteocalcin, and collagen type I was found to be upregulated and alizarin red S staining was positive in transfected ADSCs, indicating BMP-2-induced osteogenesis. Therefore, this study determined that polyethylenimine was able to mediate BMP-2 gene delivery and induce osteogenic differentiation of ADSCs.

[Safety and efficacy of Cox-maze Ⅲ procedure for patients with atrial fibrillation associated with rheumatic mitral valve disease]

OBJECTIVE

To evaluate the safety and efficacy of cut-and-sew Cox-Maze (CM) Ⅲ procedure for patients with atrial fibrillation associated with rheumatic mitral valve disease.

METHODS

Patients received mitral valve replacement and CM procedure between January 2007 and July 2015, were 1∶1 matched and assigned to CM Ⅳ group (undergoing surgical ablation) and CM Ⅲ group (undergoing cut-and-sew CM Ⅲ). Safety indices, mortality rate, complications and recovery rate of sinus rhythm were compared between the two groups.

RESULTS

Mean extracorporeal circulation time was (154±22) min in the CM Ⅲ group and (136±21) min in the CM Ⅳ group (P<0.001), and aortic clamp time was (85±9) min in the CM Ⅲ group and (74±12) min in the CM Ⅳ group (P<0.001). One patient (1.18%) in the CM Ⅲ group died of multi-organ failure 4 day after left ventricular rupture being sucessfully repaired, and 2 patients died (2.35%) in the CM Ⅳ group ( 1 due to left ventricular rupture and 1 due to low cardiac output syndrome). There was no significant difference in mortality between the two groups. Temporary pacemaker were applied for 76 cases (89.41%) in the CM Ⅲ and 70 cases (82.35%) in the CM Ⅳ group, without a statistical difference (P=0.186). There were also no statistical difference between the two groups in intraoperative urinary volume, postoperative drainage of fluid volume, hemoglobinuria, ventilator time, ICU time, hospital stay and the incidence of the complications (all P>0.05). Sinus rhythm recovery rate was 62.35 % in the CM Ⅲ group and 57.65 % in the CM Ⅳ group, without a statistical difference (P=0.531) at the operation day, but at discharge a statistical difference was found (97.62% in the CM Ⅲ group vs 81.93% in the CM Ⅳ group, P<0.001). All patients were followed up for three months, and no deaths occurred. Sinus rhythm recovery rate was 96.43 % in the CM Ⅲ group and 86.75% in the CM Ⅳ group, with a statistical difference (P=0.024).

CONCLUSION

The cut-and-sew Cox-Maze Ⅲ procedure is a safe and effective method for patients with atrial fibrillation associated with rheumatic mitral valve disease.

[The effect and safety of tirofiban on acute ST segment elevation myocardial infarction patients receiving no early reperfusion therapy]

OBJECTIVE

To study the efficacy and safety of tirofiban on acute ST segment elevation myocardial infarction (STEMI) in patients who do not receive early reperfusion therapy.

METHODS

A total of 153 STEMI patients without early reperfusion therapy were randomly distributed into tirofiban group (therapeutic group, n=78) and non-tirofiban group (control group, n=75). Coronary angiography was performed on the 5(th) and 10(th) day after treatment, and percutaneous coronary intervention (PCI) was conducted when necessary. The differences of initial patency of the infarct related artery (IRA), bleeding complication and clinic events within 30 days between these two groups were compared.

RESULTS

Tirofiban did not increase the percentage of patients with initial patency of IRA (60.3% vs 64.0%, P=0.63). The percentage of patients with thrombolysis in myocardial infarction (TIMI) 3 after PCI was 100.0% in tirofiban group and 97.1% in the control group (P=0.09). However, application of tirofiban significantly decreased poor myocardial perfusion rate after PCI (1.4% vs 8.8%, P=0.04). No significant differences were observed in major adverse cardiovascular events (MACE) (3.8% vs 2.7%, P=0.68) between therapeutic and control group. The same is true for mild (5/78 vs 4/75 cases, P=0.78) and severe hemorrhage (2/78 vs 1/75 cases, P=0.58), and severe thrombocytopenia (2/78 vs 0/75 cases, P=0.10) between these two groups within 30 days.

CONCLUSIONS

Tirofiban did not increase initial patency in STEMI patients without early reperfusion therapy. However, it can improve myocardial perfusion after PCI.

Functional Interfaces Constructed by Controlled/Living Radical Polymerization for Analytical Chemistry

The high-value applications of functional polymers in analytical science generally require well-defined interfaces, including precisely synthesized molecular architectures and compositions. Controlled/living radical polymerization (CRP) has been developed as a versatile and powerful tool for the preparation of polymers with narrow molecular weight distributions and predetermined molecular weights. Among the CRP system, atom transfer radical polymerization (ATRP) and reversible addition-fragmentation chain transfer (RAFT) are well-used to develop new materials for analytical science, such as surface-modified core-shell particles, monoliths, MIP micro- or nanospheres, fluorescent nanoparticles, and multifunctional materials. In this review, we summarize the emerging functional interfaces constructed by RAFT and ATRP for applications in analytical science. Various polymers with precisely controlled architectures including homopolymers, block copolymers, molecular imprinted copolymers, and grafted copolymers were synthesized by CRP methods for molecular separation, retention, or sensing. We expect that the CRP methods will become the most popular technique for preparing functional polymers that can be broadly applied in analytical chemistry.

A simple way to fine tune the redox potentials of cobalt ions encapsulated in nitrogen doped graphene molecular catalysts for the oxygen evolution reaction

A simple approach to fine-tuning the redox potential of Co²⁺ ions encapsulated in nitrogen doped graphene (NG) has been proposed. We found that the redox potential determines the oxygen evolution reaction activity of the catalyst.

Emerging enantiomeric resolution materials with homochiral nano-fabrications

The major scientific challenge of enantiomeric separation is to develop simple, rapid, and sensitive routine analytical methods. Generally, enantio-resolution is still based on "three-point interaction" theory, which indicates that homochiral sites are needed for enantio-selective interaction. However, in recent years, advanced materials with precise homochiral fabrication at the nanoscale have been synthesized, and have shown great potential in development of high-throughput enantio-resolution methods. This tutorial review summarizes fabrication and applications of homochiral materials for enantio-selective recognition and separation. These materials, which include intrinsic and restructured chiral metal surfaces, plasmonic nanostructures, coordination polymers, organic polymer sensors, and molecularly imprinted polymers, have been applied as sensors or chiral stationary phases (CSPs) for efficient enantio-resolution.

Ice crystals growth driving assembly of porous nitrogen-doped graphene for catalyzing oxygen reduction probed by in situ fluorescence electrochemistry

In recent years, doped carbonaceous materials as alternative catalysts for oxygen reduction reaction (ORR) have received considerable attention due to the low cost and high CO tolerance capability. Different theoretical studies have suggested that oxygen is reduced in a rapid sequence intermediated by diverse oxygen-containing reactive intermediates (ORI). However, due to the short lifetimes of the possible ORI, direct experimental evidence is very difficult to be obtained. Here, we report the synthesis of an ultralight and porous nitrogen-doped graphene (NG) by annealing graphite oxide (GO)-melamine scaffold shaped in ice template. The resultant NG exhibits excellent electrocatalytic activity toward 4e-reduction of oxygen with the onset potential as low as -0.05 V vs. Ag/AgCl in alkaline media. Using this material as model study, sensitive in situ fluorescence spectroelectrochemistry is applied to demonstrate the presence the reactive ORI. The global ORR pathway is unraveled as stepwise electron transfer involving hydroxyl radical as the important intermediate via both inner- and outer-sphere process. This result would likely provide a new insight into the further understanding of ORR mechanism on those intrinsic carbonaceous materials.

KCNE1 112G>a polymorphism and atrial fibrillation risk: a meta-analysis

KCNE1, a membrane protein that spans the membrane once is responsible for modulating potassium channel functions and plays an important role in the etiology of arrhythmia. Emerging evidence indicates that a common polymorphism (112G>A; rs1805127 G>A) in the KCNE1 gene contributes to atrial fibrillation (AF) risk; however, these studies showed inconclusive results. In this meta-analysis, we derived a more precise estimation of the association between the KCNE1 112G>A polymorphism and AF risk. The following databases were searched: Web of Science (1945-2013), the Cochrane Library Database (Issue 12, 2013), PubMed (1966-2013), EMBASE (1980-2013), CINAHL (1982-2013), and the Chinese Biomedical Database (1982-2013). The crude odds ratios with their 95% confidence intervals were calculated. Nine case-control studies were included, with a total of 1792 AF patients and 1924 healthy controls. The meta-analysis results indicated that the KCNE1 112G variant is associated with an increased risk of AF. Further subgroup analysis based on ethnicity revealed significant associations between the KCNE1 112G variant and an increased risk of AF among both Asians and Caucasians. No publication bias was detected in this meta-analysis. In conclusion, our results indicate that the KCNE1 112G polymorphism may be a risk factor for AF. KCNE1 112G>A may be useful as a biomarker for predicting the development of AF.

Sensitive determination of reactive oxygen species in cigarette smoke using microchip electrophoresis-localized surface plasmon resonance enhanced fluorescence detection

A sensitive approach to the determination of reactive oxygen species (ROS) in puffs of cigarette smoke (CS) has been developed. The experimental system consists of a microfluidic chip electrophoresis and a laser induced fluorescence (LIF) device enhanced by localized surface plasmon resonance. Core-shell Ag@SiO2 nanoparticles were prepared and then immobilized on the surface of the microchannel to increase the fluorescence intensity based on localized surface plasmon resonance-enhanced fluorescence (LSPREF) effect. The ROS in puffs of CS were trapped via the oxidation of 2',7'-dichlorodihydrofluorescein (DCHF) that had been loaded on polyacrylonitrile (PAN) nanofibers in a micro-column. Determination of ROS was based on the amount of 2',7'-dichlorofluorescein (DCF), which is the sole product from DCHF oxidation. With the optimization of the trapping efficiency, we detected about 8.0 pmol of ROS per puff in the mainstream CS. This microchip electrophoresis-SPREF system enables sensitive quantitation of ROS in CS with low consumption of reagent, material, and analysis time.

Core-shell Ag@SiO(2) nanoparticles concentrated on a micro/nanofluidic device for surface plasmon resonance-enhanced fluorescent detection of highly reactive oxygen species

A micro/nanofluidic device integrating a nanochannel in a microfluidic chip was developed for sensitive fluorescent determination of highly reactive oxygen species (hROS) enhanced by surface plasmon resonance-enhanced fluorescence (SPREF). The nanochannel was simply fabricated by polyaniline nanostructures modified on a glass slide. Core-shell Ag@SiO2 nanoparticles were concentrated in front of the nanochannel for fluorescence enhancement based on the SPREF effect. As a demonstration, hROS in the mainstream of cigarette smoke (CS) were detected by the present micro/nanofluidic device. The fluorescent probe for trapping hROS in puffs of CS employed a microcolumn that was loaded with a composite of DNA (conjugated fluorophores, FAM) and Au membrane (coated on cellulose acetate). With a laser-induced fluorescence detection device, hROS was determined on the basis of the amount of FAM groups generated by DNA cleavage. With the optimization of the trapping efficiency, we detected about 4.91 pmol of hROS/puff in the mainstream CS. This micro/nanofluidic-SPREF system promises a simple, rapid, and highly sensitive approach for determination of hROS in CS and other practical systems.

Assessment of heavy metals/metalloid (As, Pb, Cd, Ni, Zn, Cr, Cu, Mn) concentrations in edible fish species tissue in the Pearl River Delta (PRD), China

The major aim of this study was to investigate heavy metal content of edible fish in the PRD. Eleven species of fish (consisting of 711 individuals) [catfish (Clarias fuscus), tilapia (Oreochromis mossambicus), grass carp (Ctenopharyngodon idellus), bighead carp (Aristichthys nobilis), mandarin fish (Siniperca kneri), snakehead (Channa asiatiea), black bass (Micropterus salmoides), mangrove snapper (Lutjanus griseus), star snapper (Lutjanu stellatus), snubnose pompano (Trachinotus blochii) and orange-spotted grouper (Epinephelus coioides)] were collected for the analyses of heavy metals. Overall concentrations (mg/kg, ww) in the fish muscles were: As (0.03-1.53), Pb (0.03-8.62), Cd (0.02-0.06), Ni (0.44-9.75), Zn (15.7-29.5), Cr (0.22-0.65), Cu (0.79-2.26), Mn (0.82-6.91). Significant level of Pb were found in tilapia at all locations. It is recommended that heavy metal concentrations in different fish species must be determined on a regular basis in the future so as to reduce human health risks from acute and chronic food intoxication.

Heat transfer coefficient of cryotop during freezing

Cryotop is an efficient vitrification method for cryopreservation of oocytes. It has been widely used owing to its simple operation and high freezing rate. Recently, the heat transfer performance of cryotop was studied by numerical simulation in several studies. However, the range of heat transfer coefficient in the simulation is uncertain. In this study, the heat transfer coefficient for cryotop during freezing process was analyzed. The cooling rates of 40 percent ethylene glycol (EG) droplet in cryotop during freezing were measured by ultra-fast measurement system and calculated by numerical simulation at different value of heat transfer coefficient. Compared with the results obtained by two methods, the range of the heat transfer coefficient necessary for the numerical simulation of cryotop was determined, which is between 9000 W/(m(2)·K) and 10000 W/(m (2)·K).

Agents that induce pseudo-allergic reaction

Pseudo-allergic reactions may result from the activation of inflammatory or anaphylactic mechanisms independent of antigen-specific immune responses. Recent statistics show that pseudo-allergic reactions may represent as high as two thirds of all immediate hypersensitivity reactions, implying a great amount of morbidity and numerous health care costs. In this review, we concentrate on agents mediating pseudo-allergic reactions and evaluate accurately the available information on their modes of action. The agents discussed here are divided into three types: (i) Direct mast cell activators, which may activate mast cells in an IgE-independent manner, such as opioid drugs, basic secretagogues and calcium ionophore A23187; (ii) Complement activators, including liposomes, radiocontrast media and Cremophor EL, which may activate the complement system by different pathways: the classical pathway, the mannose-binding lectin pathway or the alternative pathway; (iii) Nonsteroidal anti-inflammatory drugs, which may inhibit the function of cyclooxygenase-1, resulting in the occurrence of adverse reactions. In addition, nonclinical detection methods of pseudo-allergic reactions are also reviewed in order to supply valuable information for clinical diagnosis.

[FTIR spectral fitting algorithm based on continuous wavelet transform]

An FTIR spectrum fitting algorithm based on continuous wavelet transform is proposed. In calculating the factor of difference spectrum, the algorithm takes into account both the original spectrum and its continuous wavelet transformed spectra, which effectively overcomes the problem of reference peak selection and manual factor selection in most commercial software. The detailed discussions on wavelet scale, order and basis are included. The spectral fitting is performed on six wavelet basis functions and the obtained scale factor is used to quantify the content of liquor, and the corresponding mean absolute error ranges from 0.047 to 0.072, and the standard deviation ranges from 0.056 to 0.091. Experimental results show that the CWT combined with least squares fitting provides an accurate and reliable new method for FTIR spectral subtraction.