Permanent Photodynamic Activation of the Cholecystokinin 2 Receptor

The cholecystokinin 2 receptor (CCK2R) is expressed in the central nervous system and peripheral tissues, playing an important role in higher nervous and gastrointestinal functions, pain sensation, and cancer growth. CCK2R is reversibly activated by cholecystokinin or gastrin, but whether it can be activated permanently is not known. In this work, we found that CCK2R expressed ectopically in CHO-K1 cells was permanently activated in the dark by sulfonated aluminum phthalocyanine (SALPC / AlPcS4, 10-1,000 nM), as monitored by Fura-2 fluorescent calcium imaging. Permanent CCK2R activation was also observed with AlPcS₂, but not PcS₄. CCK2R previously exposed to SALPC (3 and 10 nM) was sensitized by subsequent light irradiation (> 580 nm, 31.5 mW·cm^-2). After the genetically encoded protein photosensitizer mini singlet oxygen generator (miniSOG) was fused to the N-terminus of CCK2R and expressed in CHO-K1 cells, light irradiation (450 nm, 85 mW·cm^-2) activated in-frame CCK2R (miniSOG-CCK2R), permanently triggering persistent calcium oscillations blocked by the CCK2R antagonist YM 022 (30 nM). From these data, it is concluded that SALPC is a long-lasting CCK2R agonist in the dark, and CCK2R is photogenetically activated permanently with miniSOG as photosensitizer. These properties of SALPC and CCK2R could be used to study CCK2R physiology and possibly for pain and cancer therapies.

Stability of 5,5-dimethyl-1-pyrroline-N-oxide as a spin-trap for quantification of hydroxyl radicals in processes based on Fenton reaction

Fenton reaction was used to produce hydroxyl radicals under conditions similar to AOPs with 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) as a spin trap agent in electron paramagnetic resonance (EPR) analysis. A theoretical kinetics model was developed to determine conditions under which the spin-adduct DMPO-OH is not further oxidized by Fe(3+) and excessive radicals, so that hydroxyl radicals concentration could be accurately inferred. Experiments were designed based upon the model and H2O2 and Fe(2+) concentrations were varied from 1 to 100 mM and from 0.1 to 10 mM, respectively, with a constant H2O2: Fe(2+) ratio of 10:1. Results confirmed that DMPO concentration should be at least 20 times higher than the concentration of H2O2 and 200 times higher than iron concentration to produce stable DMPO-OH EPR signal. When DMPO: H2O2 ratio varied from 1 to 10, DMPO-OH could generate intermediates and be further oxidized leading to the apparition of an additional triplet. This signal was attributed to a paramagnetic dimer: its structure and a formation mechanism were proposed. Finally, the utilization of sodium sulfite and catalase to terminate Fenton reaction was discussed. Catalase appeared to be compatible with DMPO. However, sodium sulfite should be avoided since it reacted with DMPO-OH to form DMPO-SO3.

Serial analysis of gene expression in adenocarcinoma samples and normal colonic mucosa in a Chinese population

The goal of this study was to identify the differences in gene expression between adenocarcinoma samples and colonic normal mucosa of a Chinese population. Gene expression libraries of adenocarcinoma and normal colonic mucosa were generated by serial analysis of gene expression (SAGE). Expression tags were obtained from sequencing results using the SAGE2000 software. Representative genes of tags were determined based on the SAGEmap from NCBI. Expressed genes were selected and their expression in different libraries was compared using the SPSS 17.0 software. The expression of 78 tags representing 88 types of genes showed significant differences. Compared with normal mucosa, 38 genes showed decreased expression in cancer, whereas the expression of the remaining 50 genes showed significant up-regulation. Expressed tags in SAGE libraries of normal and cancerous tissues were significantly different. Further studies examining these genes, which showed different expression levels between the 2 tissues, may be used as tumor markers and offer clues for studying the etiopathogenesis of colon cancer.

INT-dehydrogenase activity test for assessing anaerobic biodegradability of organic compounds

This study assessed anaerobic biodegradability of organic compounds from microorganism activity. Dehydrogenase activity can be a good parameter characterizing the microorganism activity. A modified method of 2-(p-iodophenyl-3-(p-nitrophenyl)-5-pheny tetrazolium chloride-dehydrogenase activity determination was proposed in anaerobic biodegradability assessment. Cubic spline curves were adopted to link the data points. This curve was integrated twice to calculate areas. The microorganism activity index in anaerobic biodegradability assessment was calculated by standardizing the integral. According to the results of the activity index, 14 kinds of organic compounds were classified into readily, partially, and poorly biodegradable under anaerobic conditions, respectively. As a result, some conclusions for anaerobic biodegradability of organic compounds were reached, based on the activity index value.

Biological treatment of dye wastewaters using an anaerobic-oxic system

Three dye solutions, namely, C.I. Acid Yellow 17, C.I. Basic Blue 3, and C.I. Basic Red 2, were treated in an upflow anaerobic sludge blanket (UASB) reactor followed by a semi-continuous aerobic activated sludge tank. When hydraulic retention time was about 12 hours, no significant color removal was observed in the aerobic stage. In the anaerobic stage, Acid Yellow 17, Basic Blue 3, and Basic Red 2 were removed by 20%, 72%, and 78%, respectively. To treat wastewater from a dye manufacturing factor with COD concentration of 1200 mg/l and Color of 500 degrees (dilution factor), an UASB reactor (4.5 liters) and an activated sludge tank (5 liters, adjustable), COD and color were removed by more than 83% and 90% at a COD loading rate of 5.3 kg COD/m3-day in the anaerobic stage, and at the hydraulic retention time of 6-10 hours for the anaerobic stage and 6.5 for the aerobic stage. The anaerobic stage of the A/O system removes both color and COD. In addition, it also improves biodegradability of dyes for further aeroic treatment.

Teaching chronic psychiatric inpatients to use differential attention to change each other's behaviors

For nine months, all psychiatric inpatients who came into a 26-bed coed adult ward in a state hospital were taught the principles and application of differential attention to determine whether it could be a used as a significant therapeutic modality on a ward for chronic patients. In two half-hour classes each week, patients were encouraged to praise each other's desirable behaviors and ignore undesirable ones. Thirteen patients were measured for improvement of 21 behaviors that included self-care, adaptive, and social skills. The target behaviors doubled in frequency as a result of the intervention, and praise improved the performance of target behaviors whether the praise was prompted by staff or not. Men and women improved equally from the intervention. Behaviors that were consistently prompted by patients improved more than self-initiated behaviors. Patients who volunteered to be helped by peer praise appeared to benefit the most.

The crystallographic study of the complex of the Lys active fragment of the mung bean trypsin inhibitor with bovine trypsin

The Lys fragment of mung bean trypsin inhibitor can combine with bovine trypsin to form a complex at an equal molar ratio. The single crystals of the complex were obtained by using the micro-still-setting method and the X-ray diffraction extended to 1.8A resolution. Its space group is P212121 with cell dimensions a = 62.9(1)A, b = 63.4(1)A and c = 69.7 (2)A. There is one complex molecule in a crystallographic asymmetric unit.