A diagnostic challenge for schistosomiasis japonica in China: consequences on praziquantel-based morbidity control

Worldwide schistosomiasis continues to be a serious public health problem. Over the past five decades, China has made remarkable progress in reducing Schistosoma japonicum infections in humans to a relatively low level. Endemic regions are currently circumscribed in certain core areas where re-infection and repeated chemotherapy are frequent. At present, selective chemotherapy with praziquantel is one of the main strategies in China's National Schistosomiasis Control Program, and thus diagnosis of infected individuals is a key step for such control. In this paper we review the current status of our knowledge about diagnostic tools for schistosomiasis japonica. A simple, affordable, sensitive, and specific assay for field diagnosis of schistosomiasis japonica is not yet available, and this poses great barriers towards full control of schistosomiasis. Hence, a search for a diagnostic approach, which delivers these characteristics, is essential and should be given high priority

Cordycepin reverses cisplatin resistance in human bladder cancer cells via the PTEN/PI3K/AKt pathway

Purpose: To study the influence of cordycepin (Cor) on cisplatin insensitivity in bladder carcinoma, and its underlying mechanism of action.Methods: The effects of cisplatin and Cor treatments on the viability of T24-sensitive and T24/DDPinsensitive bladder carcinoma cells were investigated by using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) method to assess selectivity index. Flow cytometry was employed to evaluate the apoptosis of T24/DDP-resistant bladder cancer cells treated with cisplatin and Cor. The concentrations of PTEN, p-AKt and Akt in T24/DDP-resistant bladder cancer cells treated with cisplatin and Cor were determined by western blot assay.Results: Compared with T24-sensitive cells, the sensitivity of T24/DDP-resistant bladder cancer cells to cisplatin was significantly decreased, along with significant increase in half-inhibitory concentration (IC50) value, resulting in 10.56-fold increase in resistance (p < 0.05). The median effective concentration (EC50) value of Cor for DDP reversal was 1.03 ± 0.15 μM, and it had a high selectivity index for normal cells (> 48.5). The results from flow cytometry showed that Cor significantly enhanced the apoptosisinducing capacity of DDP in T24/DDP-resistant cells (p < 0.05), while Western blot data indicate that PTEN protein expression increased and phosphorylated Akt protein expression decreased in T24/DDPresistantcells after Cor treatment when compared with control group (p < 0.05).Conclusion: Cordycepin significantly improves the sensitivity of T24/ DDP-resistant bladder cancer cells to cisplatin via a mechanism related to the activation of PTEN/AKt signaling pathway, thus indicating that it is a potential candidate reversing DDP-resistance in bladder cancer. Keywords: Bladder cancer, Cordycepin, Cisplatin resistance, PTEN/Akt signaling pathwa

Antioxidant Properties of Polysaccharide from the Brown Seaweed Sargassum graminifolium (Turn.), and Its Effects on Calcium Oxalate Crystallization

We investigated the effects of polysaccharides from the brown seaweed Sargassum graminifolium (Turn.) (SGP) on calcium oxalate crystallization, and determined its antioxidant activities. To examine the effects of SGP on calcium oxalate crystallization, we monitored nucleation and aggregation of calcium oxalate monohydrate crystals, using trisodium citrate as a positive control. We assessed antioxidant activities of SGP by determining its reducing power, its ability to scavenge superoxide radicals, and its activity in the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. The nucleation inhibition ratio of trisodium citrate and SGP was 58.5 and 69.2%, respectively, and crystal aggregation was inhibited by 71.4 and 76.8%, respectively. Increasing concentrations of SGP resulted in increased scavenging of superoxide anions and DPPH radicals (IC50 = 1.9 and 0.6 mg/mL, respectively). These results suggest that SGP could be a candidate for treating urinary stones because of its ability to inhibit calcium oxalate crystallization and its antioxidant properties

Pharmacological isolation of postsynaptic currents mediated by NR2A- and NR2B-containing NMDA receptors in the anterior cingulate cortex

NMDA receptors (NMDARs) are involved in excitatory synaptic transmission and plasticity associated with a variety of brain functions, from memory formation to chronic pain. Subunit-selective antagonists for NMDARs provide powerful tools to dissect NMDAR functions in neuronal activities. Recently developed antagonist for NR2A-containing receptors, NVP-AAM007, triggered debates on its selectivity and involvement of the NMDAR subunits in bi-directional synaptic plasticity. Here, we re-examined the pharmacological properties of NMDARs in the anterior cingulate cortex (ACC) using NVP-AAM007 as well as ifenprodil, a selective antagonist for NR2B-containing NMDARs. By alternating sequence of drug application and examining different concentrations of NVP-AAM007, we found that the presence of NVP-AAM007 did not significantly affect the effect of ifenprodil on NMDAR-mediated EPSCs. These results suggest that NVP-AAM007 shows great preference for NR2A subunit and could be used as a selective antagonist for NR2A-containing NMDARs in the ACC

Numerical study on the coupled vibration characteristics of dual-rotors system with little rotation speed difference

In view of statically indeterminate structures of the decanter centrifuge, an iteration calculation model of nonlinear bearing stiffness is built innovatively. Based on gear meshing stiffness, material and lubricant film damping, coupled dual-rotors vibration model of screw-differential mechanism-bowl is constructed using solid elements. Applying ANSYS modal analysis, critical speeds along with vibration modes of dual-rotors and single-rotor are simulated, and the impacts of the differential mechanism and single-rotor modal on dual-rotors modal are obtained. Built on the harmonic response analysis, the results indicate that the system responses differently for the different rotors by manipulating the dynamic responses of the centrifuge under single rotor unbalance excitation. On the basis of transient structural analysis, beat vibration characteristics of dual-rotors system with little rotation speed difference are obtained, and a conclusion of the system responses separately for the unbalance mass of different rotors at a low rotating speed is acquired. The models and methods adopted in simulation are proved to be reasonable and feasible by experiment. The results have certain significance for the design and the dynamic balancing technique of the decanter centrifuge