Involvement of Holotrichia parallela odorant-binding protein 3 in the localization of oviposition sites.

Organic fertilizers-derived volatiles attract Holotrichia parallela during oviposition. However, the mechanisms underlying the perception of oviposition cues in H. parallela remain unclear. Here, H. parallela odorant-binding protein 3 (HparOBP3) was identified as a key OBP. Bioinformatics analysis showed that HparOBP3 clustered together with Holotrichia oblita OBP8. HparOBP3 was mainly expressed in the antennae of both sexes. Recombinant HparOBP3 exhibited distinct binding affinities towards 22 compounds released by organic fertilizers. After 48 h of RNA interference (RNAi), the expression of HparOBP3 in male and female antennae was decreased by 90.77 % and 82.30 %, respectively. In addition, silencing of HparOBP3 significantly reduced the electrophysiological responses and tropism of males to cis-3-hexen-1-ol, 1-hexanol, and (Z)-ß-ocimene as well as females to cis-3-hexen-1-ol, 1-hexanol, benzaldehyde, and (Z)-ß-ocimene. Molecular docking indicated that hydrophobic residues Leu-83, Leu-87, Phe-108, and Ile-120 of HparOBP3 were important amino acids for interacting with ligands. Mutation of the key residue, Leu-83, significantly diminished the binding ability of HparOBP3. Furthermore, acrylic plastic arena bioassays showed that the attraction and oviposition indexes of organic fertilizers to H. parallela were reduced by 55.78 % and 60.11 %, respectively, after silencing HparOBP3. These results suggest that HparOBP3 is essential in mediating the oviposition behavior of H. parallela.

PI3K/Akt/CncC signaling pathway mediates the response to EPN-Bt infection in Holotrichia parallela larvae.

BACKGROUND: Combining the entomopathogenic nematode (EPN), Heterorhabditis beicherriana LF strain, and Bacillus thuringiensis (Bt) HBF-18 strain is a practical strategy to manage the larvae of Holotrichia parallela Motschulsky (white grubs). However, the mechanisms underlying the larval defense response to this combined biocontrol strategy are unknown. RESULTS: The activities of some antioxidant enzymes (SOD, POD, CAT) and some detoxifying enzymes (AChE, P-450, CarE, GST) in grubs showed an activation-inhibition trend throughout the EPN-Bt exposure time course. Eight potentially key antioxidant and detoxifying enzyme genes in response to EPN-Bt infection were identified from the midgut of grubs through RNA sequencing. After silencing CAT, CarE18, and GSTs1, the enzyme activities were significantly decreased by 30.29%, 68.80%, and 34.63%, respectively. Meanwhile, the mortality of grubs was increased by 18.40%, 46.30%, and 42.59% after exposure to EPN-Bt for 1 day. Interestingly, the PI3K/Akt signaling pathway was significantly enriched in KEGG enrichment analysis, and the expression levels of phosphatidylinositol 3-kinase (PI3K), protein kinase B (Akt), cap 'n' collar isoform-C (CncC), kelch-like ECH-associated protein 1 (Keap1), and CarE18 were all up-regulated when exposed to EPN-Bt for 1 day. Furthermore, RNAi-mediated PI3K silencing showed a similar down-regulated trend between PI3K/Akt/CncC and CarE18. Moreover, silencing PI3K rendered grubs more susceptible to EPN-Bt and accelerated symbiotic bacteria multiplication in grubs. CONCLUSION: These results suggest that the PI3K/Akt/CncC pathway mediates the expression of CarE18 and participates in the defense response of H. parallela larvae against EPN-Bt infection. Our data provide valuable insights into the design of appropriate management strategies for this well-known agricultural pest. © 2022 Society of Chemical Industry.

Molecular characterization of sex pheromone binding proteins from Holotrichia oblita (Coleoptera: Scarabaeida).

Pheromone binding proteins (PBPs), a subfamily of the odorant binding proteins (OBPs), capture and transfer sex pheromones across the sensillum lymph to pheromone receptors and initiate insect courtship and mating. In this study, we functionally characterized ten OBPs from the black chafer, Holotrichia oblita (HoblOBPs), among which six HoblOBPs (HoblOBP2, 4, 5, 8, 9 and 24) were shown to recognize sex pheromones using electroantennography assays (EAG) and in vitro fluorescence competitive binding assays. Insect tropism to sex pheromones was significantly reduced after those genes were knocked down in vivo, e.g. HoblOBP24 RNAi reduced the tropism of H. oblita to methyl glycinate by 34%. Furthermore, molecular docking revealed key residues for the binding of the six HoblOBPs with sex pheromones. And hydrogen bonds and hydrophobic forces were shown to be the main forces in the binding of the six HoblOBPs and their sex pheromone ligands. Our study characterized six H. oblita PBPs and their binding abilities to sex pheromone ligands. The results will improve our understanding on the olfactory mechanisms that H. oblita utilizes to recognize sex pheromones, and will promote the development of novel strategies for controlling H. oblita and other insect pests.

[Red Mud-activated Peroxymonosulfate for Ciprofloxacin Degradation: Efficiency and Mechanism].

In this paper, the effects and mechanism of ciprofloxacin (CIP) degradation with peroxymonosulfate (PMS) catalyzed by solid waste red mud (RM) was firstly studied. The results indicated that RM has large specific surface area (10.96 m2·g-1) and complex pore structure, containing ferric, alumina and calcium oxide, which enhanced ciprofloxacin degradation by PMS effectively. Radical quenching experiments revealed that SO4-·and HO·were contributed to ciprofloxacin oxidation, and the reaction was mainly occurred on RM's surface. An increase in temperature could accelerate CIP degradation, and the corresponding reaction activation energy Ea was about 5.74 kJ·mol-1. Meanwhile, CIP degradation rate increased with PMS concentration and the optimal dosage of RM was 1.0 g·L-1. Eight degradation intermediates were identified using HPLC/MS/MS, and consequently, CIP was degraded mainly through two pathways; the piperazine groups were preferentially attacked by active free radicals. This study further indicated that RM is a cheap catalyst and can be potentially used in the treatment of antibiotic contaminated wastewater.

The mechanism underlying OBP heterodimer formation and the recognition of odors in Holotrichia oblita Faldermann.

Insect odorant-binding proteins (OBPs) play key roles in transport odors to receptors and contribute to insect survival. The cooperative interaction of HoblOBP1 and HoblOBP2 in Holotrichia oblita Faldermann (Coleoptera: Melolonthidae) could increase their binding capacity for ligands. In present study, molecular docking results showed that OBP1/OBP2 complex formed a large binding pocket and interacted with the ligands by hydrogen bonds and hydrophobic interactions. Then, nine amino acids for single site mutations, three paired for double sites, and negative control were mutated into alanine successfully by site-directed mutagenesis. Finally, fluorescence binding assays of these mutants showed that breaking one or two pairs of hydrogen bonds between HoblOBP1 and HoblOBP2 or formed with the ligands significantly decrease the binding affinity with the ligands. However, hydrophobic site mutants still showed slight binding affinity to the ligands. Therefore, the three pairs of hydrogen bonds involved in heterodimer formation and the five hydrogen bonding sites in binding pocket played a key role in response to odors in H. oblita. Our findings may promote further understanding of the mechanisms underlying OBP dimer formation and the role of OBP dimers in odor perception and discrimination.

Molecular and functional characterization of odorant-binding protein genes in Holotrichia oblita Faldermann.

Holotrichia oblita is one of the nastiest pests in China. In present research, four full-length cDNA encoding of HoblOBP genes were cloned and sequenced from H. oblita. The mRNA of HoblOBPs were predominantly expressed in antenna. The recombinant HoblOBPs proteins were obtained for fluorescence binding assays. Four of HoblOBPs could mediate the response of H. oblita to organic fertilizers-derived attractants, including HoblOBP5 binding to skatole; HoblOBP8 binding to p-cresol, indole and skatole; HoblOBP9 binding to indole and 4-allylanisole; and HoblOBP24 binding to p-cresol, indole and 4-ethylphenol. Further, RNA interference demonstrated that transcripts of HoblOBP5, 8, 9, and 24 decreased in a time-dependent manner after dsRNA-injection. Knockdown of HoblOBP5, 8, 9, and 24 by injection of dsRNA successfully interfered with behavioral responses towards the target compounds in beetles. Our results showed that HoblOBP5, HoblOBP8, HoblOBP9 and HoblOBP24 are essential in mediating the approach behavior of H. oblita.

[Behavioral responses of Holotrichia oblita larvae to root exudates from three host plants]. / 华北大黑鳃金龟幼虫对3ç§å¯„ä¸»æ¤ç‰©æ ¹ç³»åˆ†æ³Œç‰©çš„è¶‹æ€§ååº”.

The larva of Holotrichia oblita is a serious soil pest that feed with plant roots in north China. To explore the effects of host root exudates on the larva could provide theoretical basis for the development of green prevention and control methods. In order to elucidate the behavioral responses of Holotrichia oblita larva to the roots of peanut, soybean and maize, an experiment was conducted using the Y-olfactometers with the air as control. The constituents of the root exudates from the three host plants were identified by the gas chromatography-mass spectrometer (GC-MS). The olfactory responses of H. oblita larvae to the main components were tested. The results showed that H. oblita larvae had a significant behavioral preference toward the roots of peanut, soybean and maize than the control. The GC-MS analysis showed that the main components of volatile compounds in the three plants had more than twenty compounds, with only three shared ones, which was glycerol, dodecanol, ethyl benzene. The results of the Y-olfactometers showed that at low concentrations (40 to 80 µg·mL-1), the number of insects attracted by compound 2-butenoic acid, methylsuccinic acid, myristic acid, acetic acid and phthalate was significantly higher than that of control. At the concentrations of 100 µg·mL-1, 200 µg·mL-1, compound tetradecane and hexadecane were more attractive to the larvae than the control. The compounds p-xylene, o-xylene, and palmitic acid glycerol were found to significantly induce the larva at the concentration of 300 µg·mL-1 and 500 µg·mL-1. In summary, the main components of plant root exudates had a significant luring effect on H. oblita larvae.

Iodine-enhanced ultrasound degradation of sulfamethazine in water.

This study investigated sulfamethazine (SMT) ultrasound degradation, enhanced by iodine radicals, generated by potassium iodide (KI) and hydrogen peroxide (H2O2) in situ. The results showed that the ultrasound/H2O2/KI (US/H2O2/KI) combination treatment achieved an 85.10 ±â€¯0.45% SMT removal (%) in 60 min under the following conditions: pH = 3.2, ultrasound power of 195 W, initial SMT concentration of 0.04 mmol·L-1, H2O2 concentration of 120 mmol·L-1, and KI concentration of 2.4 mmol·L-1. UV-Vis spectrophotometric monitoring of molecular iodine (I2) and triiodide (I3-) revealed a correlation between the SMT degradation and the iodine change in the solution. Quenching experiments using methanol, t-butanol and thiamazole as radical scavengers indicated that iodine radicals, such as I and I2-, were more important than hydroxyl radicals (HO) for SMT degradation. SMT degradation under the US/H2O2/KI treatment followed pseudo-first order reaction kinetics. The activation energy (Ea) of SMT degradation was 7.75 ±â€¯0.61 kJ·mol-1, which suggested the reaction was controlled by the diffusion step. Moreover, TOC removal was monitored, and the obtained results revealed that it was not as effective as SMT degradation under the US/H2O2/KI system.

Cell penetrating peptide of sodium-iodide symporter effect on the I-131 radiotherapy on thyroid cancer.

The aim of the present study was to clarify whether the cell penetrating peptide of sodium-iodide symporter (NIS) has an effect on the I-131 radiotherapy of thyroid cancer. Firstly, we combined the HIV-1 TAT peptide (a cell penetrating peptide, dTAT) and established a nanoparticle vector (dTAT NP) to study the delivery efficiency of this cell-penetrating strategy for tumor-targeted gene delivery. dTAT NP was transfected into cultured TPC-1 cells as a model to study the effects of I-131 radiotherapy on thyroid cancer. Reverse transcription-quantitative polymerase chain reaction and western blotting results showed that the mRNA and protein expression levels of NIS in the transfected TPC-1 cells were substantially higher than in the negative control cells. MTT and flow cytometric analyses demonstrated that the cell growth and apoptosis rates of the TPC-1 cells were significantly inhibited and activated, respectively, by treatment with dTAT NP. The results of DAPI staining showed that treatment with dTAT NP visibly increased the nuclear apoptosis rate of the TPC-1 cells. The effect of dTAT NP on TPC-1 cells was associated with the promotion of caspase-3 and downregulation of the PI3K/Akt signaling pathway. In summary, the present data provide a pre-clinical proof-of-concept for a novel gene delivery system that efficiently delivers NIS to the targeted cancer cells and presents a satisfactory efficacy. This approach may offer an effective strategy for improving thyroid cancer gene therapy.

Identification of candidate chemosensory genes by transcriptome analysis in Loxostege sticticalis Linnaeus.

Loxostege sticticalis Linnaeus is an economically important agricultural pest, and the larvae cause great damage to crops, especially in Northern China. However, effective and environmentally friendly chemical methods for controlling this pest have not been discovered to date. In the present study, we performed HiSeq2500 sequencing of transcriptomes of the male and female adult antennae, adult legs and third instar larvae, and we identified 54 candidate odorant receptors (ORs), including 1 odorant receptor coreceptor (Orco) and 5 pheromone receptors (PRs), 18 ionotropic receptors (IRs), 13 gustatory receptors (GRs), 34 odorant binding proteins (OBPs), including 1 general odorant binding protein (GOBP1) and 3 pheromone binding proteins (PBPs), 10 chemosensory proteins (CSPs) and 2 sensory neuron membrane proteins (SNMPs). The results of RNA-Seq and RT-qPCR analyses showed the expression levels of most genes in the antennae were higher than that in the legs and larvae. Furthermore, PR4, OR1-4, 7-11, 13-15, 23, 29-32, 34, 41, 43, 47/IR7d.2/GR5b, 45, 7/PBP2-3, GOBP1, OBP3, 8 showed female antennae-biased expression, while PR1/OBP2, 7/IR75d/CSP2 showed male antennae-biased expression. However, IR1, 7d.3, 68a/OBP11, 20-22, 28/CSP9 had larvae enriched expression, and OBP15, 17, 25, 29/CSP5 were mainly expressed in the legs. The results shown above indicated that these genes might play a key role in foraging, seeking mates and host recognition in the L. sticticalis. Our findings will provide the basic knowledge for further studies on the molecular mechanisms of the olfactory system of L. sticticalis and potential novel targets for pest control strategies.

[Enhancement of Sulfamerazine Degradation Under H2O2/KI System by Ultrasound and UVA Irradiation].

The degradation of Sulfamerazine(SMR) enhanced by molecular iodine under ultrasound/H2O2/KI and UVA/H2O2/KI was investigated. The main affecting parameters, iodine generation, active species and degradation products in the two systems were discussed as well. The experimental results showed that sulfamerazine degradation was effectively enhanced in both systems, and the enhancement of ultrasound was much better. The initial pH had an obvious effect on sulfamerazine removal in the range of 2.6-5.6, and the SMR removal efficiency decreased with initial pH value. Iodine radicals (I2-·, I·) were determined as the main species in ultrasound/H2O2/KI and UVA/H2O2/KI systems. HPLC/MS/MS analysis indicated that iodo-benzene was detected in both system.

[TiO2-Induced Photodegradation of Levofloxacin by Visible Light and Its Mechanism].

Levofloxacin is an emerging pollutant. Single levofloxacin and TiO2 have no visible-light activity. However, photodegradation of levofloxacin dramatically enhanced in the presence of TiO2 under visible light irradiation. Considering this finding, he photodegradation of levofloxacin over TiO2 was investigated under visible light irradiation. Effects of TiO2 dosage, levofloxacin concentration, and solution pH on levofloxacin photodegradation were examined by monitoring its concentration decay with time. The results showed that levofloxacin photodegradation fitted the Langmuir-Hinshelwood kinetic model. Solution pH, TiO2 dose, and levofloxacin concentration had significant effects on the photodegradation rates. In addition, batch adsorption experiments revealed that adsorption of levofloxacin on TiO2 conformed to the pseudo-second-order kinetics and the Langmuir isotherm. DRS spectrum of levofloxacin-adsorbed TiO2 suggested that a surface complex was formed between levofloxacin and TiO2. Addition of radical scavengers and N2-degassing affecting levofloxacin photodegradation indicated that the superoxide ion radical was mainly active species. UV-Vis spectra of a deaerated TiO2 and levofloxacin suspensions further confirmed that the electron injection into TiO2 conduction band took place under visible light irradiation. Based on these results, a charge-transfer mechanism initiated by photoexcitation of TiO2/ levofloxacin surface complex was proposed for levofloxacin photocatalytic degradation over TiO2 under visible light. This study indicates that the charge-transfer-complex-mediated photocatalytic technique has promising applications in the removal of colorless organic pollutants.

[Norfloxacin Solution Degradation Under Ultrasound, Potassium Persulfate Collaborative System].

High oxidative sulfate radicals can be produced by potassium persulfate (K2S2O8). The integrated effect of ultrasonic and K2S2O8, on norfloxacin degradation was investigated. The experimental parameters such as K2S2O8 concentration, norfloxacin initial concentration, initial pH value, free radicals quenching agents such as methanol and tert-butyl on norfloxacin degradation were discussed. The results indicated that ultrasonic/K2S2O8, system had an obvious degradation and mineralization effect on norfloxacin. Norfloxacin removal efficiencies were 3.2 and 8.9 times in ultrasonic/K2S2O8 system than those in single K252O8 and ultrasonic oxidation system, respectively. And the reaction followed the first-order kinetics. Norfloxacin removal efficiency varied gently with K2S2O8 concentration. Solution initial pH had a significant effect on norfloxacin degradation, which was attributed to the different oxidizing species under different pH values. The radicals were sulfate radicals under acidic and neutral conditions, and was the combination of sulfate and hydroxyl radicals under alkaline conditions. TOC and agar diffusion test with E. coli showed that 49.12% norfloxacin was mineralized and antibacterial activity was completely removed, with the diameter of E. coli inhibition zone decreased from 45 mm to 14 mm (filter paper diameter). The result implied that ultrasound/K2S2O8 showed promising results as a possible application for treatment of norfloxacin antibiotics wastewater.

[Photocatalytic reductive degradation of direct red 4BE by phosphotungstic acid].

The photoreductive degradation of Azo-dye Direct Red 4BE (4BE) in aqueous solution was studied in a batch photoreactor, with phosphatotungstic acid (H3PW12O40, PW12) as the homogeneous catalyst and isopropanol as the electron donor. The parameters such as concentrations of PW12, isopropanol and 4BE, ionic strength were carefully evaluated. The results showed that 4BE could be reductively decolorized by heteropoly blue, which was produced by phosphatotungstic acid in the presence of isopropanol under UV irradiation. The decolorization rate reached 90.39% within 50 min at a pH value of 2.0, a 4BE initial concentration of 50 mg x L(-1), a PW12 and IS concentration of 600 mg x L(-1) and 0.13 mol x L(-), respectively. The decolonization rate of 4BE increased with the increase of PW12 and isopropanol concentrations until reaching a constant value. However, the first-order rate constants k for the degradation of 4BE decreased with the increase of the 4BE initial concentration. Mutual effects were found between the concentration of isopropanol and PW12 on the photocatalytic degradation of 4BE. Moreover, the concentration of salt showed a negative effect on the photoreductive degradation of 4BE. It was assumed that the charge-transfer occurred within the complex formed by heteropoly bule and 4BE, which led to the reduction of 4BE and regeneration of heteropoly bule. This study indicates that PW12/isopropanol/UV system could be used for the reductive degradation of azo dyes.

2-Amino-N,3-dimethyl-benzamide.

In the title compound, C9H12N2O, the mean plane through the amide group and the benzene ring form a dihedral angle of 33.93 (7)°. An intra-molecular N-H⋯O hydrogen bond is present. In the crystal, mol-ecules are linked by N-H⋯N and N-H⋯O hydrogen bonds, forming double-stranded chains parallel to the b axis.

[In vivo and in vitro stability of ¹³¹I-Herceptin and its form of existence in the blood of rabbits].

OBJECTIVE: To evaluate the in vivo and in vitro stability of (131)I-Herceptin and its form of existence in the blood. METHODS: Herceptin was labelled with iodine-131 using the Iodogen method. (131)I-Herceptin was stored at 4 degrees celsius for 3, 24, 48, 72 and 96 h, and the radiochemical purity (RCP) was measured by high performance liquid chromatography (HPLC). Five rabbits received injections of (131)I-Herceptin and at 1, 3, 6, 24, 48, 72, 96 and 120 h after the injection, blood samples were taken to measure the RCP of (131)I-Herceptin in the serum, and the radio count of the serum and blood cells was calculated. RESULTS: The baseline RCP of (131)I-Herceptin was (94.9±2.7)%. The RCP was stable after placement at 4 degrees celsius for not over 72 h (F=15.985, P<0.001), but was significantly lowered to (82.6±2.8)% after preservation for over 72 h (t=9.971, P<0.001). Within the time of 1.0 to 96 h after injection in rabbits, (131)I-Herceptin existed mainly in the serum with a radio count of 81%-87%; 24 h after the injection, the RCP of (131)I-Herceptin in the serum was significantly lowered to (75.4±3.9)% (t=6.564, P<0.001). CONCLUSION: Storage at 4 degrees celsius for no more than 72 h does not obviously affect the activity of (131)I-Herceptin in terms of RCP. After injection in rabbits, (131)I-Herceptin exists mainly in the serum and its radiochemical purity remains stable within 24 h, after which obvious degradation occurs.

Identification and molecular characterization of a new member of the peritrophic membrane proteins from the meadow moth, loxostege sticticalis.

The peritrophic membrane (PM) plays an important role in protecting insects. The PM proteins are important to determinate the formation and function of the PM. A new PM protein, named Lsti99, was identified from the PM of Loxostege sticticalis larvae by cDNA library screening. The full cDNA of Lsti99 is 1392 bp in length, contains an open reading frame (ORF) of 1245 bp that encodes a preprotein of 415 amino acid residues with a 17-amino acid signal peptide. The sequence of Lsti99 showed no homology to other known PM proteins. The recombinant Lsti99 was successfully expressed in insect cells (Sf9) using recombinant baculoviruses and was used to isolate the antibodies to Lsti99 from the polyclonal antiserum. Lsti99 was expressed mainly in the PM, but weaker bands could be detected in the head and integument as well. The Lsti99 protein could be separated from the PM complex by chitinase in vitro, but M2R did not show effect in vitro confirming the chitin-binding activity of Lsti99. The biochemical and physiological functions of Lsti99 in L. sticticalis require further investigation.

[Mechanism of cardiotoxicity associated with Herceptin using (131)I-Herceptin radioimmunoimaging].

OBJECTIVE: To study the mechanism of cardiotoxicity associated with Herceptin. METHODS: Herceptin was labeled with iodine-131 using the Iodogen method. Radioimmunoimaging was performed in 5 rabbits at 3 h to 5 days following (131)I-Herceptin injection to investigate the biodistribution of Herceptin. (131)I-Herceptin uptake in each organ or tissue relative to that in the muscular tissue (O/M ratio) was calculated and compared. On the fifth day following the injection, the organs including the heart, lung, liver and muscles were taken for measurement of the weight and radiocounts. HER2 expression was measured by immunohistochemistry in these organs and tissues. RESULTS: The O/M ratio of the heart was significantly higher than that of the lung (P=0.032) and liver (P=0.019) at 3 h after Herceptin injection, but reduced significantly at 24 h (P=0.001). The uptake of (131)I-Herceptin in the myocardium was slightly higher that that in the muscle and intestine, but lower than that in the lung and spleen. HER2 expression showed no significant difference between the myocardium and the other tissues such as the liver, lung, and kidney (H=3.236, P=0.172). CONCLUSION: Myocardium expresses low levels of HER2 and accumulates Herceptin no more than the other tissues.

[Adsorption of Acid Red 3R on chitosan and its enhancement by Cu2+ co-sorption].

Chitosan was used for the removal of Acid Red 3R from aqueous solutions. Batch adsorption studies were carried out to investigate adsorption kinetics and thermodynamics and the effect of coexisting pH, NaCl, and Cu2+ on adsorption. Experimental data were exploited for kinetic and thermodynamic evaluations related to the adsorption processes. The kinetic data correlated well with the pseudo-second-order kinetic model, indicating the chemical sorption via complex formation/ion exchange. The equilibrium data were well fitted by three isotherm models, namely, Langmuir, Freundlich and Dubinin-Radushkevich (D-R) equations. Moreover, adsorption of Acid Red 3R onto the chitosan was found to be strongly depending on solution temperature and pH. However, the addition of sodium chloride was found to have little effect on the adsorption process. Thermodynamic studies revealed the adsorption process was exothermic in natural. The adsorption free energies derived from D-R equation were in range of 9.5-10.7 kJ x mol(-1), implying that the sorption process is a chemical ion-exchange mechanism. In addition, adsorption capacity of chitosan to Acid Red 3R was found to be greatly enhanced in the presence of Cu2+. A model correlating the concentration of Cu2+ with the enhanced amount of dye adsorbed was established.

[Relationship between fluorodeoxyglucose uptake and vascular endothelial growth factor in early-stage nasophygeal carcinoma].

OBJECTIVE: To study the overexpression of vascular endothelial growth factor (VEGF) and fluorine-18 fluorodeoxyglucose (FDG) uptake in early-stage nasopharyngeal carcinoma (NPC) and evaluate their relationship. METHODS: FDG positron emission tomography (PET) was performed in forty patients with stage I and stage II NPC. The maximum and mean standard uptake values (SUVmax and SUVmean, respectively) were measured in each patient, and the expression of VEGF was measured on paraffin sections using immunohistochemistry. RESULTS: The FDG uptake in the patients were 9.45-/+1.87 (SUVmax) and 6.04-/+1.09 (SUVmean), 8.95-/+1.91 (SUVmax) and 6.04-/+1.09 (SUVmean) in stage I patients, and 11.55-/+1.70 (SUVmax) and 7.98-/+1.1 (SUVmean) in stage II patients. The FDG uptake of stage II patients was higher than that of stage I patients. The FDG uptake of non-keratinizing differentiated carcinoma was 9.74-/+1.82 (SUVmax) and 6.82-/+1.23 (SUVmean) and 10.44-/+2.16 (SUVmax) and 6.68-/+1.35 (SUVmean) in non-keratinizing undifferentiated carcinoma, showing no significant differences between them (SUVmax: t=1.230, P>0.05; SUVmean: t=0.346, P>0.05). The VEGF-positive cells were 60.80% in the tumor. A correlation between VEGF expression and FDG uptake in he tumor was noted (r=0.460, P=0.03). CONCLUSION: VEGF overexpression is correlated to FDG uptake in patients with early-stage NPC. The SUV value reflects the glucose metabolism of NPC, and also shows the degree of oxygen insufficiency in the tumor tissue.