A mass spectrometry-based unique fragment approach for the identification of microcystins

Both qualitative and quantitative methods for the analysis of microcystin variants have been established.

Combinatorial therapy for triple negative breast cancer using hyperstar polymer-based nanoparticles

We report the ability of a novel combinatorial therapy obtained from nanoparticles of hyperstar polymers encompassing drugs to selectively target triple negative breast cancer (TNBC) cell proliferation through STAT3 and topoisomerase-II pathways.

Correlation of rainfall and levels of deoxynivalenol in wheat from Uruguay, 1997-2003

A total of 286 wheat samples for human consumption collected during 1997-2003 from four wheat-producing localities of south-western Uruguay were screened for deoxynivalenol (DON). Quantification was carried on by an immunochemical method using immunoaffinity columns and fluorimetric detection. The incidence of DON was high during the whole survey (58.5-100%), except in 1998 and 1999 in which no contamination occurred. During 2001 and 2002, 100% of samples contained detectable levels of DON, being the mean DON contents 6593 and 5880 µg kg(-1), respectively. The annual maximum levels ranged from 8800 to 11,400 µg kg(-1). A positive correlation between DON levels and precipitation was seen. The 70% of wheat samples destined for human consumption were contaminated with DON. To avoid the introduction of contaminated materials into the food chain process, the adoption of regular screening of the DON level in wheat is recommended, particularly in years with heavy rainfall during the flowering-to-early stages of grain maturity months.

Predictive value of the novel risk score BETTER (BiomarkErs and compuTed Tomography scorE on Risk stratification) for patients with unstable angina

BACKGROUND

The Braunwald classification and TIMI (Thrombolysis In Myocardial Infarction) risk score are used to stratify cardiovascular risk in patients with unstable angina (UA). However, these scores have a limited capacity in the practice of cardiology.

OBJECTIVES

This study sought to develop a new score, based on blood biomarkers and coronary computed tomographic angiography (CCTA) characteristics, for patients with UA.

PATIENTS AND METHODS

The study group consisted of 201 patients with confirmed UA. Follow-up time was 1 year; major adverse cardiac events (MACEs) included cardiovascular death, recurrent acute coronary syndrome (ACS), and re-admission to hospital. Blood biomarkers including high-sensitivity cardiac troponin T (Hs-cTnT), high-sensitivity C-reactive protein (Hs-CRP), myeloperoxidase (MPO) N-terminal pro-B-type natriuretic peptide (NT-proBNP), and ischemia-modified albumin (IMA) were measured. CCTA characteristics such as stenosis, plaque, epicardial fat volume (EFV), and calcification were evaluated. After analysis of relationships, the novel risk BETTER (BiomarkErs and compuTed Tomography scorE on Risk stratification) score was assessed in 201 patients.

RESULTS

In all, 25 MACEs (12.44 %) occurred: 2 cardiac deaths (1.00 %), 13 non-fatal myocardial infarctions (6.47 %), 10 recurrent ACS and re-admission in hospital (4.96 %). Serum levels of MPO, NT-proBNP, Hs-TnT, Hs-CRP, and IMA were correlated with MACEs (r = 0.20, r = 0.40, r = 0.18, r = 0.24, p < 0.01, respectively; r = 0.12, p > 0.05). CCTA characteristics of stenosis, plaque, EFV, and calcification were significantly correlated with MACEs (r = 0.53, r = 0.57, r = 0.42, and r = 0.52, all p < 0.01 respectively) and were significantly higher in the MACEs group than in the non-MACEs group. Thus, a new risk score was created combining biomarkers and CCTA statistics into a Cox multivariable for risk prediction of 1-year MACEs: BETTER risk score = MPO•0.1 + Hs-TnT•50 + Hs-CRP•0.4 + stenosis•9 + plaque•13 + EFV•0.2. The areas under the curve (AUC) for the prediction by Hs-cTnT, Hs-CRP, and MPO were 0.536 (95 % CI 0.409-0.662), 0.745 (95 % CI 0.641-0.850), and 0.650 (95 % CI 0.541-0.760), respectively. The AUC for the prediction of CCTA characteristics of stenosis, plaque, and EFV were 0.905 (95 % CI 0.860-0.950), 0.912 (95 % CI 0.867-0.957), and 0.835 (95 % CI 0.752-0.917), respectively. In addition, the AUC was 0.621 (95 % CI 0.492-0.750) for the Braunwald classification and 0.680 (95 % CI 0.559-0.801) for the TIMI score. The AUC for the BETTER risk score was 0.937 (95 % CI 0.902-0.972).

CONCLUSION

The BETTER risk score is new tool specifically developed for patients with UA. The score displays higher prediction accuracy in terms of discrimination and calibration than other currently available scores for risk stratification.

Peptide dendrimer-Doxorubicin conjugate-based nanoparticles as an enzyme-responsive drug delivery system for cancer therapy

Peptide dendrimers have shown promise as an attractive platform for drug delivery. In this study, mPEGylated peptide dendrimer-doxorubicin (dendrimer-DOX) conjugate-based nanoparticle is prepared and characterized as an enzyme-responsive drug delivery vehicle. The drug DOX is conjugated to the periphery of dendrimer via an enzyme-responsive tetra-peptide linker Gly-Phe-Leu-Gly (GFLG). The dendrimer-DOX conjugate can self-assemble into nanoparticle, which is confirmed by dynamic light scattering, scanning electron microscopy, and transmission electron microscopy studies. At equal dose, mPEGylated dendrimer-DOX conjugate-based nanoparticle results in significantly high antitumor activity, and induces apoptosis on the 4T1 breast tumor model due to the evidences from tumor growth curves, an immunohistochemical analysis, and a histological assessment. The in vivo toxicity evaluation demonstrates that nanoparticle substantially avoids DOX-related toxicities and presents good biosafety without obvious side effects to normal organs of both tumor-bearing and healthy mice as measured by body weight shift, blood routine test, and a histological analysis. Thus, the mPEGylated peptide dendrimer-DOX conjugate-based nanoparticle may be a potential nanoscale drug delivery vehicle for the breast cancer therapy.

Efficacy of endoscopic stapled transanal rectal resection for the treatment of rectocele

OBJECTIVE

The objective of the study was to determine the efficacy of endoscopic stapled transanal rectal resection for the treatment of rectocele.

PATIENTS AND METHODS

For this purpose, the data were collected from 61 patients with severe rectocele that underwent endoscopic stapled transanal rectal resection within the time period from April 2010 to April 2012. The pre- and post-operative Longo's obstructed defecation syndrome (ODS) were compared. The reduction of the rectocele was assessed by defecography on visit and from patients' satisfaction obtained through following up.

RESULTS

We found that the postoperative Longo's ODS was significantly lower than the preoperative value (p < 0.01); and defecography showed that the rectocele was significantly reduced or disappeared. Furthermore, 57 of the 61 (93.4%) patients expressed their satisfaction at follow up.

CONCLUSIONS

The endoscopic stapled transanal rectal resection can be recommended as the treatment of choice for rectocele since it is an easy-to-perform procedure that has satisfactory short and mid to long-term therapeutic efficacy.

Dendrimer–doxorubicin conjugate as enzyme-sensitive and polymeric nanoscale drug delivery vehicle for ovarian cancer therapy

Dendrimer–doxorubicin conjugate prepared via click chemistry was employed as enzyme-sensitive nanoscale drug delivery system for ovarian cancer therapy, showing high accumulation in tumor tissue, significantly increased antitumor activity and good biosafety.

Ferromagnetic interfacial interaction and the proximity effect in a Co2FeAl/(Ga,Mn)As bilayer

The magnetic properties of a Co2FeAl/(Ga,Mn)As bilayer epitaxied on GaAs (001) are studied both experimentally and theoretically. Unlike the common antiferromagnetic interfacial interaction existing in most ferromagnet-magnetic semiconductor bilayers, a ferromagnetic interfacial interaction in the Co2FeAl/(Ga,Mn)As bilayer is observed from measurements of magnetic hysteresis and x-ray magnetic circular dichroism. The Mn ions in a 1.36 nm thick (Ga,Mn)As layer remain spin polarized up to 400 K due to the magnetic proximity effect. The minor loops of the Co2FeAl/(Ga,Mn)As bilayer shift with a small ferromagnetic interaction field of +24 Oe and -23 Oe at 15 K. The observed ferromagnetic interfacial coupling is supported by ab initio density functional calculations. These findings may provide a viable pathway for designing room-temperature semiconductor spintronic devices through magnetic proximity effect.

Dispersion of single walled carbon nanotubes in amidine solvents

The excellent electronic and material properties of single walled carbon nanotubes (SWNTs) makes this nanomaterial very attractive for incorporation into flexible and stretchable electronics. However, the widespread application of SWNTs in electronic devices is still limited. To purify, process and place SWNTs, appropriate solvents for dispersion are needed. However, a fundamental understanding of the reasons why certain solvents are capable of dispersing SWNTs is still missing. Here we report on two new potential solvents containing amidine moieties, 1,8-diazabicycloundec-7-ene (DBU) and 1,5-diazabicyclo(4.3.0)non-5-ene (DBN). Even though these solvents' molecular structures differ by only two -CH(2)- groups, we found that DBU is capable of dispersing SWNTs, while DBN is not. We carried out density functional theory (DFT) calculations to investigate the interaction between DBU and DBN, and we elucidated the reasons for the different performances of the two solvents. DBU has a preferential edge-on interaction with the SWNT, thus allowing for a higher solvent coverage than DBN. In addition, the CH(2)-SWNT interaction present for DBU substantially increases the adsorption energy compared to DBN. Our results point to the important interplay between the interaction of pi electrons, nitrogen lone pairs and the -CH(2)- groups present in aprotic solvent molecules and the delocalized pi electrons in SWNTs.

Hypoglycemic effect and mechanism of a proteoglycan from ganoderma lucidum on streptozotocin-induced type 2 diabetic rats

BACKGROUND AND OBJECTIVES

Diabetes mellitus inducing a leading cause of morbidity are widespread in the entire globe. The present study was to investigate the antidiabetic potency and mechanism of a proteoglycan extract, named FYGL (Fudan-Yueyang-G. lucidum), from the fruiting bodies of Ganoderma Lucidum as published recently, using streptozotocin-induced type 2 diabetic mellitus (T2DM) rats.

MATERIAL AND METHODS

The T2DM model rats were treated with FYGL as well as metformin and rosiglitazone. The levels of plasma glucose and insulin were measured, and the expression and activity of the protein tyrosine phosphatase 1B (PTP1B) and the tyrosine phosphorylation level of the insulin receptor (IR) 3-subunit in the livers and skeletal muscles of the T2DM rats were analyzed by immunoprecipitation and Western blotting methods. In addition, the levels of free fatty acid and serum lipid profile were measured using commercial kits for those trailed rats.

RESULTS

The decrease in fasting plasma glucose and the increase in insulin concentration dose- and time-dependently in the T2DM rats treated by FYGL, comparable with that by the clinical drugs, metformin and rosiglitazone. The levels of the PTP1B expression and activity were decreased, and the tyrosine phosphorylation level of the IR 1-subunit was increased in the skeletal muscles of the T2DM rats. Furthermore, FYGL significantly decreased the levels of free fatty acid, triglyceride, total cholesterol and low density lipoprotein-cholesterol as well as increased the level of high density lipoprotein-cholesterol.

DISCUSSION

It is suggested that the hypoglycemic mechanisms of FYGL are caused by inhibition of the PTP1B expression and activity, consequently, regulation of the tyrosine phosphorylation level of the IR 13-subunit. As those results, FYGL also controlled the plasma biochemistry indexes relative to the type 2 diabetes-accompanied metabolic disorders. This is possibly the first report on the underlying mechanisms responsible for the antidiabetic effect of Ganoderma lucidum.

Numerical studies on the microclimate around a sleeping person and the related thermal neutrality issues

This article reports on two numerical studies on the microclimate around, and the thermal neutrality of, a sleeping person in a space installed with a displacement ventilation system. The development of a sleeping computational thermal manikin (SCTM) placed in a space air-conditioned by a displacement ventilation system is first described. This is followed by reporting the results of the first numerical study on the microclimate around the SCTM, including air temperature and velocity distributions and the heat transfer characteristics. Then the outcomes of the other numerical study on the thermal neutrality of a sleeping person are presented, including the thermal neutrality for a naked sleeping person and the effects of the total insulation value of a bedding system on the thermal neutrality of a sleeping person. STATEMENT OF RELEVANCE: The thermal environment would greatly affect the sleep quality of human beings. Through developing a SCTM, the microclimate around a sleeping person has been numerically studied. The thermal neutral environment may then be predicted and contributions to improved sleep quality may be made.

Large variation of vacancy formation energies in the surface of crystalline ice

Resolving the atomic structure of the surface of ice particles within clouds, over the temperature range encountered in the atmosphere and relevant to understanding heterogeneous catalysis on ice, remains an experimental challenge. By using first-principles calculations, we show that the surface of crystalline ice exhibits a remarkable variance in vacancy formation energies, akin to an amorphous material. We find vacancy formation energies as low as ~0.1-0.2 eV, which leads to a higher than expected vacancy concentration. Because a vacancy's reactivity correlates with its formation energy, ice particles may be more reactive than previously thought. We also show that vacancies significantly reduce the formation energy of neighbouring vacancies, thus facilitating pitting and contributing to pre-melting and quasi-liquid layer formation. These surface properties arise from proton disorder and the relaxation of geometric constraints, which suggests that other frustrated materials may possess unusual surface characteristics.

Detection of bovine herpesvirus 1 sequences in yaks (Bos grunniens) with keratoconjunctivitis, using a highly sensitive nested polymerase chain reaction

Thirty-seven yaks (Bos grunniens) with keratoconjunctivitis and 22 healthy yaks were used to investigate the role of bovine herpesvirus 1 (BoHV-1) in keratoconjunctivitis in yaks. Nucleic acid sequences of BoHV-1 glycoproteins B and E were detected in conjunctival swabs from all yaks with keratoconjunctivitis using a nested polymerase chain reaction (PCR). In 21 yaks, BoHV-1 sequences were detected along with Moraxella bovis (M. bovis) and Neisseria spp. The amplified BoHV-1 sequences were identical, and no nucleotide variation was observed when compared with a BoHV-1 reference strain using single-strand conformation polymorphism analysis of the amplified DNA sequences. Interestingly, BoHV-1 sequences could not be detected in samples from healthy yaks. However, conjunctival swabs from two healthy yaks (9.09%) yielded M. bovis and Neisseria spp. Samples from 35 yaks with keratoconjunctivitis showed positive reactions in an avidin biotin enzyme-linked immunosorbent assay for BoHV-1 antibodies; all the healthy yaks were seronegative. This is the first report of a possible association of BoHV-1 with keratoconjunctivitis in yaks.