[A simple and rapid procedure for detection of DNA damage caused by Aldicarb]

A simple and rapid procedure for detection of low levels DNA damage caused by Aldicarb was developed and compared with some other methods. In the original position the gel was set in high-pH buffer to run electrophoresis after the diluent of bacteria or fragmentized organ was added into hole of agarose gel directly and cells were treated with detergent and high alkaline condition. The impact of Aldicarb to biological individual or ecosystem was assessed according to the quantity of DNA and the extent of DNA migration.

[Sulfa-drug wastewater treatment with anaerobic/aerobic process]

Sulfa drug wastewater was treated with anaerobic/aerobic process. The removal ratios of TOC reached about 50% in anaerobic phase and about 70% in aerobic phase respectively, while volume loading rate of TOC was about 1.2 kg/(m3.d) in anaerobic phase and about 0.6 kg/(m3.d) in aerobic phase. Removal of TOC in anaerobic phase was attributed to the reduction of sulfate.

Enzyme stabilization by covalent binding in nanoporous sol-gel glass for nonaqueous biocatalysis

A unique nanoporous sol-gel glass possessing a highly ordered porous structure (with a pore size of 153 A in diameter) was examined for use as a support material for enzyme immobilization. A model enzyme, alpha-chymotrypsin, was efficiently bound onto the glass via a bifunctional ligand, trimethoxysilylpropanal, with an active enzyme loading of 0.54 wt%. The glass-bound chymotrypsin exhibited greatly enhanced stability both in aqueous solution and organic solvents. The half-life of the glass-bound alpha-chymotrypsin was >1000-fold higher than that of the native enzyme, as measured either in aqueous buffer or anhydrous methanol. The enhanced stability in methanol, which excludes the possibility of enzyme autolysis, particularly reflected that the covalent binding provides effective protection against enzyme inactivation caused by structural denaturation. In addition, the activity of the immobilized alpha-chymotrypsin was also much higher than that of the native enzyme in various organic solvents. From these results, it appears that the glass-enzyme complex developed in the present work can be used as a high-performance biocatalyst for various chemical processing applications, particularly in organic media. Published by John Wiley & Sons

Transcription factor RF2a alters expression of the rice tungro bacilliform virus promoter in transgenic tobacco plants

The promoter from rice tungro bacilliform badnavirus (RTBV) is expressed only in phloem tissues in transgenic rice plants. RF2a, a b-Zip protein from rice, is known to bind to the Box II cis element near the TATA box of the promoter. Here, we report that the full-length RTBV promoter and a truncated fragment E of the promoter, comprising nucleotides -164 to +45, result in phloem-specific expression of beta-glucuronidase (GUS) reporter genes in transgenic tobacco plants. When a fusion gene comprising the cauliflower mosaic virus 35S promoter and RF2a cDNA was coexpressed with the GUS reporter genes, GUS activity was increased by 2-20-fold. The increase in GUS activity was positively correlated with the amount of RF2a, and the expression pattern of the RTBV promoter was altered from phloem-specific to constitutive. Constitutive expression of RF2a did not induce morphological changes in the transgenic plants. In contrast, constitutive overexpression of the b-ZIP domain of RF2a had a strong effect on the development of transgenic plants. These studies suggest that expression of the b-Zip domain can interfere with the function of homologues of RF2a that regulate development of tobacco plants.

The sorption behavior of complex pollution system composed of aldicarb and surfactant--SDBS

The behavior of complex pollution system in soil composed of aldicarb, a carbamate pesticide, and sodium dodecylbenzenesulfonate (SDBS), an anionic surfactant, was studied by the experiment of shaking sorption balance. The range of concentration of aldicarb and SDBS was 0.4-5.0 and 1-1000 mg/kg of dried soil, respectively. Linear sorption isotherm was well fitted for these two chemicals. SDBS can decrease the sorption of aldicarb in soil remarkably. While the concentration of SDBS increased from 0 to 1000 mg/kg, the linear sorption coefficient can be decreased by 50%. But aldicarb showed no effect on the sorption of SDBS in experiment. In addition the mechanism of the effect of SDBS on sorption of aldicarb was discussed.

[Analysis of the lineshape of laser frequency modulation]

In this paper, we analyze the dependence of the output signal spectral lineshape and intensity on the modulation, waveform and modulation index in first- and second-harmonic detection of triangle modulation, square demodulation and saw modulation square demodulation. The signal lineshape in the case of saw modulation, square demodulation is quite different from, whereas the signal lineshape in the case of triangle modulation, square demodulation is similar to that in traditional sine modulation, sine demodulation. Experiments of tunable IR laser frequency modulation absorption spectrum of methane are also done to verify the theoretical analysis. Then we reach a conclusion; the lineshape and intensity of frequency modulation spectrum can be influenced by modulation waveform, demodulation waveform and modulation index. Calculation results can be used to choose better experimental parameters and optimize experimental designs.

[Effect of octreotide on intragastric pH in patients with duodenal ulcer bleeding]

OBJECTIVE

To evaluate the effect of octreotide on the intragastric pH of patients with duodenal ulcer bleeding during the period of 24 hours and to observe if it can advance the effect of hemostasis by endoscopic injection of epinephrine.

METHODS

Twenty-four patients with duodenal ulcer bleeding were randomly divided into three groups, eight in each. Patients in group 1 received an intravenous injection of 0.1 mg of octreotide followed by continuous intravenous drip of octreotide at a constant speed of 25 microg/h for 24 hours. The patients in group 2 received an intravenous injection of 0.1 mg of octreotide followed by continuous intravenous drip of octreotide at a constant speed of 42 microg/h for 24 hours. The patients in group 3 received an intravenous injection of 40 mg of omeprazole followed by continuous intravenous drip of omeprazole at a constant speed of 8 mg/h for 24 hours. Intragastric pH was continuously recorded with a pH meter. The patients with active ulcer bleeding was treated with injection of epinephrine via endoscope and then received intravenous drip of octreotide (with the same dosage as in group 1, n = 42) or omeprazole (with the same dosage as in group 3, n = 54) for 72 hours and were given omeprazole (20 mg Bid).

RESULTS

The mean and median intragastric pH values among the patients in group 2 treated by a larger dosage of octreotide (6.7 +/- 0.5 and 6.9 +/- 0.4) were similar to those in the group 3 treated by omeprazole (6.8 +/- 0.4 and 7.0 +/- 0.4). There was no statistically significant difference between these two groups in percentage of intragastric pH above 4, 6, and 7 The mean and median of intragastric pH among the patients in group 1 treated by a smaller dosage of octreotide were statistically significantly smaller (5.2 +/- 0.5 and 5.4 +/- 0.4) than those in the omeprazole group. There was no statistically significant difference between octreotide treatment and omeprazole treatment in terms of volume of blood transfusion (0.7 +/- 0.5 vs. 0.6 +/- 0.4 L), rebleeding rate (11.6% vs. 12.9%), emergency operation rate (7.1% vs. 3.7%), and mortality (2.3% vs. 3.7%).

CONCLUSION

Octreotide effectively inhibits the secretion of gastric acid. However, the dosage in common use clinically fails to increase the intragastric pH to the best situation needed for effective hemostasis. Only a large dosage (1.10 mg/d) works.

Hierarchically imprinted sorbents

A double imprinting methodology was developed to synthesize novel materials with hierarchical structures. On the microporous level (1-3 A), metal ions served as template. On the mesoporous level (diameters of 25-40 A), micellar structures produced by self-assembly of surfactant molecules were used as templates. Removal of both metal ions and surfactant micelles resulted in the formation of imprints with different sizes within the silica matrix, each with a specific function. This research opens vast opportunities for the applications of ordered mesoporous materials in the area of molecular recognition such as separations, chemical sensors, and catalysts.

[Adsorption of anthraquinone dyes by biosorbent GX2]

The GX2 growing mycelium shows excellent adsorptive capacity on the four kinds of anthraquinone dyes, however, due to the difference of molecular structure of dyes, the adsorption rates are different. Although the dyes show inhibiting effect on the growth of GX2, when the concentration of reactive brilliant blue KN-R is 250 and 400 mg/L, the adsorption rate of dye by the GX2 growing mycelium reaches 100% and 91.4%, respectively. With the increase of salinity (NaCl), the dry weight of GX2 mycelium increases; the diameter of granular mycelium decreases and its adsorption surface area increases accordingly, the salinity shows evident enhancement on the adsorption of reactive brilliant blue KN-R by GX2 growing mycelium in the range of 0%-2% salinity. The adsorption process is influenced by the concentration of carbon source as well, reactive brilliant blue KN-R with the concentration of 120 mg/L can be completely adsorbed only when the concentration of glucose is more than 2.5 g/L. The GX2 growing mycelium has better adsorptive capacity than resting living mycelium and dead mycelium.

[The bindings of typical aldehydes pollutants with cell DNA]

The bindings of 3 kinds of aidehyde pollutants, formaldehyde, acetaldehyde, acrolein, with both prokaryotic and eukaryotic DNA, and their genotoxic effect and mechanism were conducted by the shifts of maximum UV absorption peak to determine binding effects and by HPLC to determine binding sites in vitro model system. The shifts of maximum UV absorption peak of prokaryotic DNA contaminated by 3 kinds of aldehyde pollutants are not significant; but after the DNA extracted from prokaryotic bacteria reacting with formaldehyde in tube, the shifts of maximum UV absorption peak of DNA are significant; the shifts of maximum UV absorption peak of eukaryotic DNA contaminated by 3 kinds of aldehyde pollutants are significant also. The reacition of acetaldehyde with dG reduced by NaBH4 was separated and detected by HPLC, the product was determined qualitatively as N2-ethaldeoxyguanosine adduct. The 3 kinds of aldehyde pollutants could bind with cellular DNA to express genotoxic effects; and the N2 site of deoxyguanosine is the possible covalent binding site.

Neutron detection based upon a lithiated sol-gel glass

The addition of dopants in the wet chemistry formation of glass in sol-gel technology is used for many purposes. Among the uses are the fabrication of films sensitive to pH, temperature, the presence of dissolved chemicals in solutions and many others. This paper describes the use of sol-gel technology for the doping of B-10, Li-6 and U-235 into glass films applied to silicon surface barrier (SSB) detectors. Using a commercial preamp/amplifier and an IEEE-488 NIM counter, the response was recorded of the neutron profile in a neutron activation source. A portable personal computer recorded the thermal neutron map as the detector was lowered in 1.27-cm steps down a Numec thermal neutron activation source. The lithiated glass film on the SSB gave about four times the count rate of the boron-10 doped glass film. The U-235 doped glass film gave a much lower count rate, but maintained a constant output signal due to the presence of the alpha activity from the U-235 and the trace of U-234 present in the sample.

The bi-directional regulation of filamin on the ATPase activity of smooth muscle myosin

OBJECTIVE

The aim of this study is to investigate the functional relationship between filamin, a known actin binding protein, and myosin and the effects of filamin on the interaction between myosin and actin.

METHODS

Ultra-centrifugation method was used to investigate the binding of filamin to both phosphorylated and unphosphorylated myosins. Mg-ATPase activities of both phosphorylated and unphosphorylated myosins in the presence and absence of actin were measured to observe the effects resulted from filamin-actin and filamin-myosin interactions.

RESULTS

It was found that filamin is also a myosin binding protein. Filamin inhibited the actin activated Mg-ATPase activity of phosphorylated myosin and stimulated Mg-ATPase of phosphorylated myosin in the absence of actin; in addition, filamin stimulated Mg-ATPase activity of unphosphorylated myosin in both the presence or absence of actin.

CONCLUSION

The result suggest that the effects of filamin on the myosin Mg-ATPase activities are bi-directional, i.e., stimulatory via binding to myosin and inhibitory via binding to actin.

Optical detection of polycations via polymer film-modified microtiter plates: response mechanism and bioanalytical applications

Microtiter plate wells modified with thin (approximately 20 microm) polymeric films capable of optically sensing macromolecular protamine and other polycationic species are described. The plates are prepared by coating the bottom of each well of a conventional 96-well polypropylene plate with an adherent polymer film (a mixture of poly(vinyl chloride) and polyurethane) containing a lipophilic 2',7'-dichlorofluorescein derivative. Surprisingly, optical response toward polycations is shown to result from the extraction of the fluorescein derivative from the polymer film into a lyophobic colloidal phase at the sample/film interface. This new phase is likely composed of a micellular-type ion pair complex between the analyte polycation from aqueous sample phase and the deprotonated form of the fluorescein derivative. Accumulation of the deprotonated fluorescein species in this interfacial region induces an absorbance change measured at 540 nm. Optimized plates can be used to sense protamine concentrations in the range of 0-100 microg/mL in 10 min with little or no response to physiological levels of common cationic species (Na+, K+, Ca2+, etc.). The modified plates are shown to be useful as simple optical detectors for measuring heparin levels in plasma via titrations with protamine and for monitoring protease activities (trypsin and plasmin) that cleave polycationic peptides/proteins such as protamine into smaller peptide fragments that are not detected by the sensing films. Assays for "clot busting" plasminogen activators (streptokinase, urokinase, and tissue plasminogen activator) are also demonstrated using this relatively simple microtiter plate-based polycation detection system.

[Study on interferon gamma and interleukin-4 contents of plasma and cultured monoclear cell supernatants in patients with endometriosis]

OBJECTIVE

To investigate the cytokin production of T helper cell (Th) 1, Th2 subsets in patients with endometriosis(EM).

METHODS

The cytokine production of Th1, Th2 cells expressed by interferon-gamma (IFN-gamma) and interleukin-4 (IL-4) contents respectively in supernatants of cultured PHA induced peripheral blood mononuclear cell (PBMC) and plasma, obtained from 30 EM patients and 15 normal controls were determined by enzyme linked immunoabsorbent assay (ELISA).

RESULTS

IL-4 contents of EM patients were elevated both in plasma and PBMC supernatants[(32.0 +/- 22.6) ng/L and (32.8 +/- 12.5) ng/L, respectively], while IFN-gamma levels was suppressed in PBMC supernatant as compared with normal controls [(1,095.6 +/- 375.6) ng/L and (1,549.3 +/- 361.9) ng/L, respectively] (P < 0.01, P < 0.05). As a results, the ratio of IFN-gamma/IL-4 decreased in EM patients.

CONCLUSIONS

Changes of IFN-gamma and IL-4 contents in EM patients may reflect functional inbalance between Th1 and Th2 cells, which may play a role in the pathogenesis of EM.

Neuronal distribution and functional characterization of the calcium channel alpha2delta-2 subunit

The auxiliary calcium channel alpha2delta subunit comprises a family of three genes, alpha2delta-1 to 3, which are expressed in a tissue-specific manner. alpha2delta-2 mRNA is found in the heart, skeletal muscle, brain, kidney, liver and pancreas. We report here for the first time the identification and functional characterization of alpha2delta-2 splice variants and their mRNA distribution in the mouse brain. The splice variants differ in the alpha2 and delta protein by eight and three amino acid residues, respectively, and are differentially expressed in cardiac tissue and human medullary thyroid carcinoma (hMTC) cells. In situ hybridization of mouse brain sections revealed the highest expression of alpha2delta-2 mRNA in the Purkinje cell layer of the cerebellum, habenulae and septal nuclei, and a lower expression in the cerebral cortex, olfactory bulb, thalamic and hypothalamic nuclei, as well as the inferior and superior colliculus. As the in situ data did not suggest a specific colocalization with any alpha1 subunit, coexpression studies of alpha2delta-2 were carried out either with the high-voltage-gated calcium channels, alpha1C, alpha1E or alpha1A, or with the low-voltage-gated calcium channel, alpha1G. Coexpression of alpha2delta-2 increased the current density, shifted the voltage dependence of channel activation and inactivation of alpha1C, alpha1E and alpha1A subunits in a hyperpolarizing direction, and accelerated the decay and shifted the steady-state inactivation of the alpha1G current.

A family of gamma-like calcium channel subunits

The gamma subunit was initially identified as an auxiliary subunit of the skeletal muscle calcium channel complex. Evidence for the existence of further gamma subunits arose following the characterization of a genetic defect that induces epileptic seizures in stargazer mice. We present here the first account of a family of at least five putative gamma subunits that are predominantly expressed in brain. The gamma-2 and gamma-4 subunits shift the steady-state inactivation curve to more hyperpolarized potentials upon coexpression with the P/Q type alpha(1A) subunit. The coexpression of the gamma-5 subunit accelerates the time course of current activation and inactivation of the alpha(1G) T-type calcium channel.