High-Throughput/High-Precision Sampling of Single Cells into ICP-MS for Elucidating Cellular Nanoparticles.

In single-cell analysis with ICP-MS it is highly important to ensure precise single-cell sampling into ICP. For this purpose, a simple configured pressure-resistant MicroCross interface is developed for high-throughput/high-precision microdroplet generation and single-cell encapsulation. Aqueous cell suspension is ejected and sheared into droplets by tangent-flowing hexanol-continuous phases in the flow-focusing geometry of MicroCross, wherein to precisely trap a single cell into a droplet, with an extremely low probability of <0.005% for a single droplet encapsulating two cells. MicroCross interface is coupled with time-resolved ICP-MS (TRA-ICP-MS) for quantifying nanoparticles in single MCF-7 cells. At the optimal conditions, sufficient temporal-spatial resolution of the microdroplets is achieved facilitating high-throughput sampling of single cells into ICP. For solving the serious carbon deposition on the sampling cone and the unstable plasma torch caused by incomplete oxidation of hexanol phase in ICP, dimethyl carbonate (DMC) is for the first time used as a superb oxygen compensation reagent, which ensures adequate oxidation of hexanol, effectively eliminates the carbon deposition, and maintains a stable plasma. The single-cell analysis results indicated a remarkable discrepancy of the number of nanoparticles among the individual cells, falling into a range of 130-584 per MCF-7 cell in the case of AuNPs.

Relationship between cytotoxic T-lymphocyte antigen 4 -318C/T (rs5742909) gene polymorphism and the risk of acute rejection in renal transplantation.

Results on the relationship between CTLA4 -318C/T (rs5742909) gene polymorphism and risk of acute rejection in renal transplantation are still conflicting. This meta-analysis was performed to update the association between CTLA4 -318C/T and risk of acute rejection in renal transplantation. The association investigations were identified from PubMed and Cochrane Library, and eligible studies were included and synthesized using meta-analysis method. Twelve reports were included in this meta-analysis for the association of CTLA4 -318C/T gene polymorphism with acute rejection risk in renal transplantation, consisting of 728 acute rejection patients and 1628 non-acute rejection controls. The association between CTLA4 -318C/T gene polymorphism and acute rejection risk in renal transplantation for overall populations was not found in this meta-analysis (T allele: OR=0.96, 95% CI: 0.60-1.54, P=.88; TT genotype: OR=0.90, 95% CI: 0.47-1.71, P=.74; CC genotype: OR=1.00, 95% CI: 0.62-1.59, P=.98). Interestingly, T allele was associated with the risk of acute rejection in renal transplantation in African population. In conclusion, CTLA4 -318C/T gene polymorphism is not associated with the risk of acute rejection in renal transplantation in overall populations.

Association of cytotoxic T-lymphocyte antigen 4 +49A/G gene polymorphism with acute rejection risk in renal transplantation.

The conclusions on the association between cytotoxic T-lymphocyte antigen 4 (CTLA4) +49A/G gene polymorphism and acute rejection risk in renal transplantation are still debated. This meta-analysis was performed to update the association between CTLA4 +49A/G and acute rejection risk in renal transplantation. The association investigations were identified from PubMed and Cochrane Library, and eligible studies were included and synthesized using meta-analysis method. Fourteen reports were included into this meta-analysis for the association of CTLA4 A/G gene polymorphism and acute rejection risk in renal transplantation, consisting of 962 acute rejection patients and 2084 non-acute rejection controls. The association between CTLA4 G allele/GG genotype and acute rejection risk in renal transplantation was found in this meta-analysis (G allele: OR=1.21, 95% CI: 1.03-1.44, P=.02; GG genotype: OR=1.37, 95% CI: 1.10-1.69, P=.004). However, the AA genotype was not associated with acute rejection risk in renal transplantation. In conclusion, CTLA4 G allele/GG genotype is associated with the acute rejection risk in renal transplantation.

In situ self-assembled reduced graphene oxide aerogel embedded with nickel oxide nanoparticles for the high-efficiency separation of ovalbumin.

A three-dimensional reduced graphene oxide aerogel with embedded nickel oxide nanoparticles was prepared by a one-step self-assembly reaction in a short time. The nanoparticles could be captured into the interior of reduced graphene oxide network during the formation of the three-dimensional architecture. The composite exhibited porosity, good biocompatibility, and abundant metal affinity binding sites. The aerogel was used to isolate ovalbumin selectively from egg white, and favorable adsorption was achieved at pH 3. An adsorption efficiency of 90.6% was obtained by using 1 mg of the composite for adsorbing 70 µg/mL of ovalbumin in 1.0 mL of sample solution, and afterwards a recovery of 90.7% was achieved by using an eluent of 1.0 mL Britton-Robinson buffer solution at pH 5. After the adsorption/desorption, ovalbumin showed no change in the conformation. The adsorption behavior of ovalbumin on the reduced graphene oxide composite well fitted to the Langmuir adsorption model, and a corresponding theoretical maximum adsorption capacity was 1695.2 mg/g. A sodium dodecyl sulfate polyacrylamide gel electrophoresis assay demonstrated that the aerogel could selectively isolate ovalbumin from chicken egg white.

Multitarget sensing of glucose and cholesterol based on Janus hydrogel microparticles.

A visualized sensing method for glucose and cholesterol was developed based on the hemispheres of the same Janus hydrogel microparticles. Single-phase and Janus hydrogel microparticles were both generated using a centrifugal microfluidic chip. For glucose sensing, concanavalin A and fluorescein labeled dextran used for competitive binding assay were encapsulated in alginate microparticles, and the fluorescence of the microparticles was positively correlated with glucose concentration. For cholesterol sensing, the microparticles embedded with γ-Fe2O3 nanoparticles were used as catalyst for the oxidation of 3,3',5,5'-Tetramethylbenzidine by H2O2, an enzymatic hydrolysis product of cholesterol. And the color transition was more sensitive in the microparticles than in solutions, indicating the microparticles are more applicable for visualized determination. Furthermore, Janus microparticles were employed for multitarget sensing in the two hemespheres, and glucose and cholesterol were detected within the same microparticles without obvious interference. Besides, the particles could be manipulated by an external magnetic field. The glucose and cholesterol levels were measured in human serum utilizing the microparticles, which confirmed the potential application of the microparticles in real sample detection.

[The study of the risk factors of fungal infection after liver transplantation].

OBJECTIVE: To explore the risk factors of fungal infection so as to provide rationales for the prevention of fungal infection after liver transplantation. METHODS: The clinical data of 94 cases of fungal infections after liver transplantation from January 1, 2003 to November 30, 2010 at our hospital were collected as the infective group. A total of 603 liver transplant patients without fungal infections during the same period were selected as the control group. χ(2) test and t test were utilized for the analysis of possible risk factors for fungal infection. RESULTS: Fungal infection rate was 13.5% (94/697) after liver transplantation and mortality rate of fungal infection 86.2% (81/94). Candida albicans was the majority infective fungi. And the main site of infection was the lungs. The postoperative acute physiology and chronic health evaluation III (APACHE III) score of the infective group was significantly higher than that of the control group (26.0 ± 5.4 vs 21.5 ± 4.7, P < 0.01). The number of patients with primary liver cancer was lower than that of the control group (26.6% vs 45.8%, P < 0.01). The number of decompensated HBV cirrhosis and diabetics in the infective group was higher than that of the control group at pre-operation (23.4% vs 11.6%, 9.6% vs 2.8%, both P < 0.01). The number of patients with postoperative mechanical ventilation over 10 days, postoperative antibiotics over 14 days, postoperative cardiopulmonary dysfunction and liver function recovery time over 7 days, parenteral nutrition over 12 days and hyperglycemia over 7 days in the infective group were significantly higher than that in the control group (all P < 0.01). CONCLUSION: Preoperative primary disease, postoperative disease severity, postoperative organ dysfunction, long-term mechanical ventilation, antibiotics and hyperglycemia, etc. may be the important risk factors of fungal infection after liver transplantation.

Fungal infection in patients after liver transplantation in years 2003 to 2012.

BACKGROUND: Fungal infections after liver transplantation have received considerable interests because of their association with substantial morbidity and mortality. This study investigated risk factors of fungal infection after liver transplantation. MATERIAL/METHODS: Retrospective analysis was performed based on clinical data from 120 patients with fungal infection after liver transplantation from January 1, 2003 to May 30, 2012. χ2 test was used to analyze risk factors for fungal infections. RESULTS: The fungal infection rate after liver transplantation is 13.5% (120/886) and the case fatality rate reaches 70.8%; most are infected by Candida albicans (67.5%), with infection located in the lung (73.3%). Acute physiology and chronic health evaluation scores of the infected group are higher than those of the control group 24 hours after the surgery (27.1±5.2 vs. 21.9±5.0). The percentage of primary liver cancer patients in the infected group was lower than in the control group (26.7% vs. 45.8%). Compared to the control group, the infected group had a higher percentage of patients with HBV, gestational diabetes mellitus, and multiple organ dysfunction syndrome. Percentages of patients with long continuous parenteral nutrition time, poorly controlled high blood sugar, long-term mechanical ventilation, and antibiotics use were higher in the infected group than in the control group. CONCLUSIONS: Preoperative original attack, postoperative critical condition, chronically high blood sugar, long-term use of antibiotics, and mechanical ventilation are probably vital risk factors for fungal infection after liver transplantation.

Brønsted acid-catalyzed efficient Strecker reaction of ketones, amines and trimethylsilyl cyanide.

A general method for the one-pot, three-component Strecker reaction of ketones was developed using Brønsted acids as organocatalysts. A series of alpha-aminonitriles were obtained in good to excellent yields (79-99%). A preliminary extension to a catalytic enantioselective three-component Strecker reaction of ketones (up to 40% ee) is also described.