Distinct Expression Profiles and Different Functions of Odorant Binding Proteins in Nilaparvata lugens Stål

Background: Odorant binding proteins (OBPs) play important roles in insect olfaction. The brown planthopper (BPH), Nilaparvata lugens Sta˚l (Delphacidae, Auchenorrhyncha, Hemiptera) is one of the most important rice pests. Its monophagy (only feeding on rice), wing form (long and short wing) variation, and annual long distance migration (seeking for rice plants of high nutrition) imply that the olfaction would play a central role in BPH behavior. However, the olfaction related proteins have not been characterized in this insect. Methodology/Principal Findings: Full length cDNA of three OBPs were obtained and distinct expression profiles were revealed regarding to tissue, developmental stage, wing form and gender for the first time for the species. The results provide important clues in functional differentiation of these genes. Binding assays with 41 compounds demonstrated that NlugOBP3 had markedly higher binding ability and wider binding spectrum than the other two OBPs. Terpenes and Ketones displayed higher binding while Alkanes showed no binding to the three OBPs. Focused on NlugOBP3, RNA interference experiments showed that NlugOBP3 not only involved in nymph olfaction on rice seedlings, but also had non-olfactory functions, as it was closely related to nymph survival. Conclusions: NlugOBP3 plays important roles in both olfaction and survival of BPH. It may serve as a potential target fo

Effects of {2-[(3-carboxy-1-oxoprogy1)amino]-2-deoxy-D-glucose} on human hepatocellular carcinoma cell line

Aim: To study the effects of {2-[(3-carboxy-1-oxoprogyl)amino]-2-deoxy-D- glucose (COPADG) on cultured human hepatocellular carcinoma cells (HepG2). Methods: HepG2 cells were cultured in RPMI-1640 medium. Cell proliferation was determined by MTT assay. Apoptosis was determined by fluorescence microscopy, transmission electron microscopy, agarose gel electrophoresis of DNA fragmentation, and flow cytometry. Results: At the concentration ranging between 1-30 μmol/L, COPADG potently inhibited the growth and induced apoptosis of HepG2 cells. Conclusion: COPADG could effectively induce apoptosis in human hepatocellular carcinoma cells. More investigations are warranted for the potential use of this compound as a new agent for the non-surgical management of human hepatocellular carcinoma. ©2005 CPS and SIMM.link_to_subscribed_fulltex

Contribution of GABAergic modulation in DRGs to electroacupuncture analgesia in incisional neck pain rats

Li Na Qiao,1,2 Yong Sheng Yang,2 Jun Ling Liu,2 Jiang Zhu,1 Lian Hong Tan,2 Yi Nan Shi,2 Bing Zhu,2 Pei Jing Rong2 1School of Acupuncture-Moxibustion and Tuina, Beijing University of Chinese Medicine, Beijing, China; 2Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, China Purpose: Acupuncture therapy is effective for relieving postoperative pain. Our previous study showed that electroacupuncture (EA) at Futu (LI18) and Hegu (LI4)–Neiguan (PC6) could alleviate incisional neck pain, which was related with its effect in upregulating γ-aminobutyric acid (GABA) expression in cervical (C3–6) dorsal root ganglions (DRGs); but whether its receptor subsets GABAAA2R and GABABR1 in C3–6 DRGs are involved in EA analgesia or not, it remains unknown. Materials and methods: Seventy-five male Sprague Dawley rats were randomized to normal control, model, LI18, LI4–PC6, and Zusanli (ST36)–Yanglingquan (GB34) groups. The incisional neck pain model was established by making a longitudinal incision along the midline of the rats’ neck, followed by repeated mechanical stimulation. EA was applied to bilateral LI18, LI4–PC6, or ST36–GB34 for 30 minutes at 4, 24, and 48 hours after operation. The thermal pain threshold of the neck was detected by a tail-flick unit, and the C3–6 DRGs were removed for assaying the immunoactivity of substance P (SP), GABAAα2R, glial fibrillary acidic protein (GFAP; a marker of satellite glial cells [SGCs]), and GABABR1 and the expression of GABAAα2R and GABABR1 mRNA and proteins using immunofluorescence, real-time PCR, and Western blotting, respectively. Results: The cervical thermal pain threshold was significantly lower in the model group than the normal group (P<0.001), indicating hyperalgesia after neck incision, and was considerably increased in both EA-LI18 and LI4–PC6 groups (P<0.001), but not in ST36–GB34 group compared with model group (P>0.05). Immunofluorescence staining showed that GABAAα2R R expressed on SP+ neurons, and GABABR1 on SGCs. EA of LI18 and LI4–PC6 markedly suppressed the modeling-induced upregulation of the immunoactivity of SP (P<0.001 and P<0.01, respectively) and GFAP (P<0.01 and P<0.001, respectively) and significantly reversed neck incision–induced downregulation of the expression of GABAAα2R and GABABR1 mRNAs and proteins (P<0.05). Conclusion: EA of LI18 and LI4–PC6 has an analgesic effect in incisional neck pain rats, which is related to its effects in upregulating GABAergic inhibitory modulation on nociceptive peptidergic neurons and SGCs in cervical DRGs. Keywords: electroacupuncture, incisional neck pain, substance P, satellite glial cells, GABAAα2R, GABABR

Numerical simulation of the stability of water fiber-optic in water jet-guided laser machining

Water jet-guided laser machining is a new compound machining technology, which has been widely used in many fields due to its better processing effect. In this technology, the coupling of laser beam and micro-water jet directly determines the machining effect, and the prerequisite for successful coupling is the steady flow of the water jet, so ensuring the stability of the micro-water jet is the key to the stable machining of water jet-guided laser. Therefore, it is of great significance to studying the stability of the water fiber-optic in water jet-guided laser processing. In this paper, aiming at the problem that the stability of the water fiber-optic is difficult to control, a finite element model of the water fiber-optic is established. The convection model is vortex gas-phase flow &ldquo;enveloped&rdquo; water fiber-optic which is used to explain the interaction mechanism, and the flow field distribution of gas-phase flow and water fiber-optic convection was obtained. The results show that water fiber-optic is refined under the constraint of gas-phase flow, and the maximum processing distance can increase by three times. At the same time, the gas-phase flow can accelerate the removal of processing debris, and the processing accuracy and efficiency are improved.</p

Study on reducing burrs of super alloy through structures in water jet guided laser ablation

With the increase of thrust-weight ratio of aero-engine, the working temperature of core parts is becoming higher and higher. In order to improve the service life of core parts, many high-precision micro holes are machined on those core parts. To realize the fabrication of micro hole with less burrs on super alloy substrates, a novel water jet guided laser processing method is proposed in this paper. A material removal principle based on plasma detonation assistant machining is proposed and proved to be valid through experiments. Then a laser-induced plasma assisted ablation method using sacrificial layer in the machining of through holes and grooves on super alloy is approved. This method can get higher machining efficiency and avoid longtime trimming in subsequent experiments. The size of burrs in through hole decreases 57.89%, while the area of burrs decreases 42.32% after using 304 stainless steel as sacrificial layer in the machining of through hole. Grooves with fewer burrs are also achieved on super alloy with this method. That method can also be used to fabricate a variety of functional structures.</p