Transient serum exposure regimes to support dual differentiation of human mesenchymal stem cells

Human mesenchymal stem cells (MSCs), which can generate both osteoblasts and chondrocytes, represent an ideal resource for orthopaedic repair using tissue‐engineering approaches. One major difficulty for the development of osteochondral constructs using undifferentiated MSCs is that serum is typically used in culture protocols to promote differentiation of the osteogenic component, whereas existing chondrogenic differentiation protocols rely on the use of serum‐free conditions. In order to define conditions which could be compatible with both chondrogenic and osteogenic differentiation in a single bioreactor, we have analysed the efficiency of new biphasic differentiation regimes based on transient serum exposure followed by serum‐free treatment. MSC differentiation was assessed either in serum‐free medium or with a range of transient exposure to serum, and compared to continuous serum‐containing treatment. Although osteogenic differentation was not supported in the complete absence of serum, marker expression and extensive mineralization analyses established that 5 days of transient exposure triggered a level of differentiation comparable to that observed when serum was present throughout. This initial phase of serum exposure was further shown to support the successful chondrogenic differentiation of MSCs, comparable to controls maintained in serum‐free conditions throughout. This study indicates that a culture based on temporal serum exposure followed by serum‐free treatment is compatible with both osteogenic and chondrogenic differentiation of MSCs. These results will allow the development of novel strategies for osteochondral tissue engineering approaches using MSCs for regenerative medicine. Copyright © 2012 John Wiley & Sons, Ltd.     

Gluconic acid aqueous solution: A bio-based catalytic medium for organic synthesis

Gluconic acid is non-toxic, non-volatile, non-corrosive, and easily biodegradable chemical, which can be produced from biomass using several methods: oxidation by molecular oxygen using heterogeneous catalysis, enzymatic oxidation, and microbial fermentation. Being highly soluble in water, gluconic acid can form concentrated aqueous solutions, and its 50% aqueous solution has found application as a catalytic medium for organic synthesis. For some reactions, gluconic acid aqueous solutions (GAAS) outperform conventional and green solvents when used as media for organic synthesis. GAAS was found to be particularly efficient in the Knoevenagel condensation, the Michael addition, and multicomponent reactions based on them. These and other chemical transformations utilizing GAAS as a medium are discussed in this review. We also compare the effectiveness of GAAS as a new green catalytic medium and the performance of other solvents and catalysts.     

Large-scale analysis of interindividual variability in single and paired-pulse TMS data

ObjectiveThis study brought together over 60 transcranial magnetic stimulation (TMS) researchers to create the largest known sample of individual participant single and paired-pulse TMS data to date, enabling a more comprehensive evaluation of factors driving response variability.MethodsAuthors of previously published studies were contacted and asked to share deidentified individual TMS data. Mixed-effects regression investigated a range of individual and study level variables for their contribution to variability in response to single and paired-pulse TMS data.Results687 healthy participant’s data were pooled across 35 studies. Target muscle, pulse waveform, neuronavigation use, and TMS machine significantly predicted an individual’s single-pulse TMS amplitude. Baseline motor evoked potential amplitude, motor cortex hemisphere, and motor threshold (MT) significantly predicted short-interval intracortical inhibition response. Baseline motor evoked potential amplitude, test stimulus intensity, interstimulus interval, and MT significantly predicted intracortical facilitation response. Age, hemisphere, and TMS machine significantly predicted MT.ConclusionsThis large-scale analysis has identified a number of factors influencing participants’ responses to single and paired-pulse TMS. We provide specific recommendations to minimise interindividual variability in single and paired-pulse TMS data.SignificanceThis study has used large-scale analyses to give clarity to factors driving variance in TMS data. We hope that this ongoing collaborative approach will increase standardisation of methods and thus the utility of single and paired-pulse TMS.     

Cross-neutralization between vaccine and circulating wild-type mumps viruses in Korea

Mumps is a contagious disease caused by the mumps virus. It can be prevented using mumps vaccines, administered as a measles-mumps-rubella (MMR) vaccine. For first and second dose immunization, children aged 12–15 months and 4–6 years have been administered this vaccine since 1997 in Korea. Nevertheless, mumps outbreaks still occur in vaccinated populations worldwide. Hence, immunity against these diseases may be attenuated, or there are antigenic differences between currently available vaccine strains and circulating wild-type viruses. After the introduction of national immunization programs in Korea, mumps cases became sporadic. Viral genotypes F, H, and I have emerged since 1998 whereas the vaccine strains belong to genotype A. Here, we compared the amino acid sequences of the haemagglutinin-neuraminidase (HN) gene from wild-type viruses and the mumps vaccine and measured the cross-neutralization titers between them. We selected the F, H, and I wild-type mumps strains circulating in Korea from 1998 to 2016 and analyzed changes in the amino acid sequence of the protein encoded by the HN gene. We measured mumps virus-specific IgG and rapid focus reduction neutralization test (FRNT) titers in Korean isolates and sera obtained from 50 children aged 1–2 years who had been administered a single dose of MMR vaccine. Analysis of the HN protein sequences disclosed no changes in the glycosylation sites but did reveal 4–5 differences between the Korean isolates and the genotype A vaccine strain in terms of the neutralizing epitope sites on their HN proteins. Post-vaccination FRNT titers were significantly lower against genotypes F, H, and I than they were against genotype A. This finding highlights the possibility of a recurrence of mumps outbreaks in vaccinated populations depending on the degree of genetic conservation of the HN gene. Further research into this issue is needed to prevent the resurgence of mumps.     

3,5-O-二咖啡酰基奎宁酸的制备及其对HeLa细胞的抗增殖活性研究

目的 制备高纯度3，5-O-二咖啡酰基奎宁酸，并评价其对人宫颈癌HeLa细胞的抗增殖活性。方法 采用柱色谱提取法和中压液相色谱法从奇蒿花中分离、纯化得到高纯度的3，5-O-二咖啡酰基奎宁酸。采用MTT法评价该化合物对人宫颈癌HeLa细胞的体外抗增殖活性。结果 柱色谱提取的提取率和中压液相色谱法的回收率分别为99.0%，61.2%，总回收率为54.0%。随着3，5-O-二咖啡酰基奎宁酸浓度升高，HeLa细胞存活率下降，细胞形态损伤增加，受试药物的IC₅₀值为26.5µg·mL^-1。结论 本研究提供了一种简单、高效、节能的3，5-O-二咖啡酰基奎宁酸制备方法。3，5-O-二咖啡酰基奎宁酸对HeLa细胞具有一定的体外抗增殖活性。     

Rociletinib (CO-1686) enhanced the efficacy of chemotherapeutic agents in ABCG2-overexpressing cancer cells in vitro and in vivo

Overexpression of adenosine triphosphate (ATP)-binding cassette subfamily G member 2 (ABCG2) in cancer cells is known to cause multidrug resistance (MDR), which severely limits the clinical efficacy of chemotherapy. Currently, there is no FDA-approved MDR modulator for clinical use. In this study, rociletinib (CO-1686), a mutant-selective epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI), was found to significantly improve the efficacy of ABCG2 substrate chemotherapeutic agents in the transporter-overexpressing cancer cells in vitro and in MDR tumor xenografts in nude mice, without incurring additional toxicity. Mechanistic studies revealed that in ABCG2-overexpressing cancer cells, rociletinib inhibited ABCG2-mediated drug efflux and increased intracellular accumulation of ABCG2 probe substrates. Moreover, rociletinib, inhibited the ATPase activity, and competed with [¹²⁵I] iodoarylazidoprazosin (IAAP) photolabeling of ABCG2. However, ABCG2 expression at mRNA and protein levels was not altered in the ABCG2-overexpressing cells after treatment with rociletinib. In addition, rociletinib did not inhibit EGFR downstream signaling and phosphorylation of protein kinase B (AKT) and extracellular signal-regulated kinase (ERK). Our results collectively showed that rociletinib reversed ABCG2-mediated MDR by inhibiting ABCG2 efflux function, thus increasing the cellular accumulation of the transporter substrate anticancer drugs. The findings advocated the combination use of rociletinib and other chemotherapeutic drugs in cancer patients with ABCG2-overexpressing MDR tumors.     

A comparison between two powder compaction parameters of plasticity: The effective medium A parameter and the Heckel 1/K parameter

The purpose of the research was to introduce a procedure to derive a powder compression parameter (EM A) representing particle yield stress using an effective medium equation and to compare the EM A parameter with the Heckel compression parameter (1/K).     

CHROMagar mSuperCARBA and RAPIDEC® Carba NP test for detection of carbapenemase-producing Enterobacteriaceae

A novel chromogenic medium CHROMagar mSuperCARBA was evaluated to detect carbapenem-resistant Gram-negatives. This medium is as sensitive and as specific as the SUPERCARBA medium for detecting KPC, MBL and OXA-48-type producers (100% and 100%, respectively) and is compatible with subsequent testing of carbapenemase activity using the RAPIDEC^® CARBA NP.     

Salidroside protects PC12 cells from MPP-induced apoptosis via activation of the PI3K/Akt pathway

Oxidative stress plays an important role in the pathogenesis of Parkinson’s disease (PD). Salidroside (SAL), a phenylpropanoid glycoside isolated from Rhodiola rosea L., can exert potent antioxidant properties. In this study, we investigated the protective effects, and the possible mechanism of action, of SAL against 1-methyl-4-phenylpyridinium (MPP⁺)-induced cell damage in rat adrenal pheochromocytoma PC12 cells. Pretreatment of PC12 cells with SAL significantly reduced the ability of MPP⁺ to induce apoptosis in a dose and time-dependent manner. SAL significantly and dose-dependently inhibited MPP⁺-induced chromatin condensation and MPP⁺-induced release of lactate dehydrogenase by PC12 cells. SAL enhanced Akt phosphorylation in PC12 cells, and the protective effects of SAL against MPP⁺-induced apoptosis were abolished by LY294002, a specific inhibitor of phosphatidylinositol 3-kinase (PI3K) phosphorylation. These findings suggest that SAL prevents MPP⁺-induced apoptosis in PC12 cells, at least in part through activation of the PI3K/Akt pathway.     

Expression of muscarinic acetylcholine receptors in hepatocytes from rat fibrotic liver

The pathological changes of parasympathetic nerve are considered as an independent prognostic factor of the survival rate of patients with chronic liver disease. The non-selective muscarinic acetylcholine receptors (mAchR) agonists and antagonists can affect the proliferation of hepatocytes and hepatic stellate cells, but the subtypes of mAchR expressions in HCs are still uncertain. Here, we investigate the expression of mAchR in hepatic fibrosis on rats. 3 ml/kg 40% carbon tetrachloride (CCL4) was given to induce hepatic fibrosis on rats and the hepatocytes were isolated. Compared to the normal state, the expression levels of m1, 3, 5 in fibrotic liver tissues or hepatocytes were obviously increased, while m2, 4 decreased. 10 μM pilocarpine or 10 μM acetylcholine could increase the alanine aminotransferase (ALT), hydroxyproline (Hyp), collagen I, III in the hepatocytes, and decreased albumin (ALB). They also changed the expressions of mAchR similarly as the fibrotic hepatocytes and livers. However, atropine could ameliorate the state of fibrotic hepatocytes. These data indicate that mAchR played an important role in the regulation of hepatic fibrosis process. Targeting mAchR would have therapeutic potential for hepatic fibrosis.