Methane and carbon dioxide are known greenhouse gases, and the conversion of these two C1-building blocks into useful fuels and chemicals is a subject of great importance. By solid-state NMR spectroscopy, we found that methane and carbon dioxide can be co-converted on a zinc-modified H-ZSM-5 zeolite (denoted as Zn/H-ZSM-5) to form acetic acid at a low temperature range of 523-773 K. Solid-state (13)C and (1)H MAS NMR investigation indicates that the unique nature of the bifunctional Zn/H-ZSM-5 catalyst is responsible for this highly selective transformation. The zinc sites efficiently activate CH4 to form zinc methyl species (-Zn-CH3), the Zn-C bond of which is further subject to the CO2 insertion to produce surface acetate species (-Zn-OOCCH3). Moreover, the Brønsted acid sites play an important role for the final formation of acetic acid by the proton transfer to the surface acetate species. The results disclosed herein may offer the new possibility for the efficient activation and selective transformation of methane at low temperatures through the co-conversion strategy. Also, the mechanistic understanding of this process will help to the rational design of robust catalytic systems for the practical conversion of greenhouse gases into useful chemicals.

Background The electrophysiology of long QT syndrome (LQTS) in utero is virtually unstudied. Our goal here was to evaluate the efficacy of fetal magnetocardiography (fMCG) for diagnosis and prognosis of fetuses at risk of LQTS. Methods and Results We reviewed the pre/postnatal medical records of 30 fetuses referred for fMCG due to a family history of LQTS (n=17); neonatal/childhood sudden cardiac death (n=3) and/or presentation of prenatal LQTS rhythms (n=12): 2° AVB, ventricular tachycardia, heart rate < 3rd percentile. We evaluated heart rate and reactivity, cardiac time intervals, T-wave characteristics, and initiation/termination of Torsade de Pointes (TdP), and compared these with neonatal ECG findings. After birth, subjects were tested for LQTS mutations. Based on accepted clinical criteria, 21 subjects (70%; 9 KCNQ1, 5 KCNH2, 2 SCN5A, 2 other, 3 untested) had LQTS. Using a threshold of QTc= 490 ms, fMCG accurately identified LQTS fetuses with 89% (24/27) sensitivity and 89% (8/9) specificity in 36 sessions. Four fetuses (2 KCNH2 and 2 SCN5A), all with QTc ≥ 620 ms, had frequent episodes of TdP, which were present 22–79% of the time. While some episodes initiated with a long-short sequence, most initiations showed QRS aberrancy and a notable lack of pause dependency. T-wave alternans was strongly associated with severe LQTS phenotype. Conclusions QTc prolongation (≥490 ms) assessed by fMCG accurately identified LQTS in utero; extreme QTc prolongation (≥620 ms) predicted TdP. FMCG can play a critical role in the diagnosis and management of fetuses at risk of LQTS.

Mifepristone (RU486) is a born-for-woman molecule discovered three decades ago. Unlike those antihypertensive and antipsychotic pharmaceutical blockbusters, this abortifacient offers relatively low profit potential. Current understanding of mechanism of action of mifepristone and its on-going clinical trials are changing our views on the drug beyond its abortifacient scope. Here we briefly review its metabolism and pharmacokinetic properties including its unique enterohepatic circulation, its mechanisms of actions involving antiprogesterone and antiglucocorticoid, growth inhibition of various cancer cell lines, suppression of invasive and metastatic cancer potential, downregulation of Cdk2, Bcl-2, and NF-kappa B, interference of heterotypic cell adhesion to basement membrane, and cell migration. We comprehensively analyze recent results from preclinical and clinical studies using mifepristone as an anticancer drug for breast, meningioma, and gliomas tumors in the central nervous system, prostate cancer, ovarian and endometrial cancer, and gastric adenocarcinoma. Although mifepristone has more benefits for global public health than we originally thought, its effect as a postmetastatic chemotherapeutic agent is limited. Nonetheless, owing to its unique safe, metabolism and other pharmacological properties, metapristone (the primary metabolite of mifepristone) may have potential for cancer metastatic chemoprevention.

Adhesion of circulating tumor cells (CTCs) to vascular endothelial bed becomes a crucial starting point in metastatic cascade. We hypothesized that nitric oxide (NO) may prevent cancer metastasis from happening by its direct vasodilation and inhibition of cell adhesion molecules (CAMs). Here we show that S-nitrosocaptopril (CAP-NO, a typical NO donor) produced direct vasorelaxation that can be antagonized by typical NO scavenger hemoglobin and guanylate cyclase inhibitor. Cytokines significantly stimulated production of typical CAMs by the highly-purified human umbilical vein endothelial cells (HUVECs). CAP-NO inhibited expression of the stimulated CAMs (particularly VCAM-1) and the resultant hetero-adhesion of human colorectal cancer cells HT-29 to the HUVECs in a concentration-dependent manner. The same concentration of CAP-NO, however, did not significantly affect cell viability, cell cycle and mitochondrial membrane potential of HT-29, thus excluding the possibility that inhibition of the hetero-adhesion was caused by cytotoxicity by CAP-NO on HT-29. Hemoglobin reversed the inhibition of CAP-NO on both the hetero-adhesion between HT-29 and HUVECs and VCAM-1 expression. These data demonstrate that CAP-NO, by directly releasing NO, produces vasorelaxation and interferes with hetero-adhesion of cancer cells to vascular endothelium via down-regulating expression of CAMs. The study highlights the importance of NO in cancer metastatic prevention.

Mifepristone (RU486) is marketed and used widely by women as an abortifacient, and experimentally for psychotic depression and anticancer treatments. After administration, metapristone is found to be the most predominant metabolite of mifepristone. We hypothesized that adhesion of circulating tumor cells (CTCs) to vascular endothelial bed is a crucial starting point in metastatic cascade, and that metapristone can serve as a cancer metastatic chemopreventive agent that can interrupt adhesion and invasion of CTCs to the intima of microvasculature. In the present study, we modified the synthesis procedure to produce grams of metapristone, fully characterized its spectral properties and in vitro cellular activities, including its cytostatic effects, cell cycle arrest, mitochondrial membrane potential, and apoptosis on human colorectal cancer HT-29 cells. Metapristone concentration dependently interrupted adhesion of HT-29 cells to endothelial cells. Metapristone may potentially be a useful agent to interrupt metastatic initiation.

BACKGROUND: This study was aimed at establishing a sensitive and specific isolation, characterization, and enumeration method for living circulating tumor cells (CTCs) in patients with colorectal carcinoma. METHODS: Quantitative isolation and characterization of CTCs were performed through a combination of immunomagnetic negative enrichment and fluorescence-activated cell sorting. Isolated CTCs were identified by immunofluorescence staining. The viability and purity of the sorted cells were determined by flow cytometry. Blood samples spiked with HCT116 cells (range, 3-250 cells) were used to determine specificity, recovery, and sensitivity. The method was used to enumerate, characterize, and isolate living CTCs in 10 mL of blood from patients with colorectal carcinoma. RESULTS: The average recovery of HCT116 cells was 61% or more at each spiking level, and the correlation coefficient was 0.992. An analysis of samples from all 18 patients with colorectal carcinoma revealed that 94.4% were positive for CTCs with an average of 33 6 24 CTCs per 10 mL of blood and with a diameter of 14 to 20 lm (vs 8-12 lm for lymphoma). All patients were CD47 1 , with only 4.3% to 61.2% being CD44 1 . The number of CTCs was well correlated with the patient TNM stage and could be detected in patients at an early cancer stage. The sorted cells could be recultured, and their viability was preserved. CONCLUSIONS: This method provides a novel technique for highly sensitive and specific detection and isolation of CTCs in patients with colorectal carcinoma. This method complements the existing approaches for the de novo functional identification of a wide variety of CTC types. It is likely to help in predicting a patient's disease progression and potentially in selecting the appropriate treatment. Cancer 2015;121:3036-45.

Background Congenital long-QT syndrome (LQTS) may present during fetal development and can be life-threatening. The molecular mechanism for the unusual early onset of LQTS during fetal development is unknown. Objective We sought to elucidate the molecular basis for severe fetal LQTS presenting at 19-weeks gestation, the earliest known presentation of this disease. Methods Fetal magnetocardiography was used to demonstrated torsade de pointes and a prolonged rate-corrected QT interval. In vitro electrophysiological studies were performed to determine functional consequences of a novel SCN5A mutation found in the fetus. Results The fetus presented with episodes of ventricular ectopy progressing to incessant ventricular tachycardia and hydrops fetalis. Genetic analysis disclosed a novel, de novo heterozygous mutation in SCN5A (L409P) and a homozygous common variant (R558). In vitro electrophysiological studies demonstrated that the mutation in combination with R558 caused significant depolarized shifts in voltage-dependence of inactivation and activation, faster recovery from inactivation and a 7-fold greater level of persistent current. When the mutation was engineered in a fetal-expressed SCN5A splice isoform, channel dysfunction was markedly potentiated. Also, R558 alone in the fetal splice isoform evoked a large persistent current, hence both alleles were dysfunctional. Conclusion We report the earliest confirmed diagnosis of symptomatic LQTS, and present evidence that mutant cardiac sodium channel dysfunction is potentiated by a developmentally regulated alternative splicing event in SCN5A. Our findings provide a plausible mechanism for the unusual severity and early onset of cardiac arrhythmia in fetal LQTS.

The selectively direct conversion of methane to methanol on Cu-exchanged zeolites has attracted a lot of interest because of the abundant availability of methane. A detailed reaction mechanism of the transformation of methane to methanol aimed to improve the catalyst design has been long expected. On the basis of EPR and solid-state NMR studies, we demonstrate that CH4 activates on the [Cu2O]2+ core of the Cu/Na–ZSM-5 zeolite, producing a ·CH3 radical and an ·OH radical. The generated methanol molecule, which formed from the combination of ·CH3 and the ·OH radicals, adsorbs on the Cu+ species and forms the copper methoxy species (−Cu–O–CH3) and the −Al–OH group. Through the process of hydration, the copper methoxy species and the adsorbed methanol transform into free methanol. We expect that our mechanistic understanding of the methane to methanol process could pave the way for catalyst design.