Dietary butylated hydroxytoluene improves lipid metabolism, antioxidant and anti-apoptotic response of largemouth bass (Micropterus salmoides)

A 10-week growth trail was conducted to investigate the efficacy and tolerance of dietary butylated hydroxytoluene (BHT) by evaluating inflammation, apoptosis and hepatic disease related to oxidative stress in largemouth bass (Micropterus salmoides). Four experimental diets were prepared with BHT supplement levels of 0 (B0), 150 (B150), 300 (B300) and 1500 (B1500) mg/kg, in which B150 was at the maximum recommended level established by European Union Regulation, and the B300 and B1500 levels were 2 and 10-fold of B150, respectively. Each diet was fed to 6 replicates with 30 largemouth bass (initial body weight, IBW = 6.20 ± 0.01 g) in each tank. The BHT inclusion level did not affect the specific growth rate, but fish in the B150 group showed the lowest feed conversion rate (P < 0.05). BHT inclusion significantly decreased the levels of plasma TC, TG, LDL, ALT and AKP, and increased the (HDL-C)/TC ratio (P < 0.05). Plasma MDA was significantly decreased in the B150 group and GSH-Px was extremely enhanced in each BHT inclusion group (P < 0.05). Hepatic T-AOC was significantly enhanced and O₂^- was significantly decreased in each BHT inclusion group compared to the B0 group (P < 0.05), as well as hepatic MDA was significantly decreased in B1500 group (P < 0.05). Dietary BHT inclusion down-regulated the hepatic mRNA levels of inflammation, apoptosis and fibrosis related genes, including TNFα, TGF-β1, α-SMA, IL8, IL11β and caspase-9. Moreover, BHT could improve hepatic lipid metabolism via up-regulating the mRNA levels of APOA1, CYP7A1, CYP8B1, and down-regulating the mRNA levels of PPAR-γ and APOB. Histological examination of the liver morphology with H&E and Sirius Red staining showed that BHT inclusion decreased necrotic degenerative changes and collagen deposition in largemouth bass. An immunofluorescence examination revealed significantly decreased cleaved caspase-3 signals in the BHT groups. In conclusion, the results demonstrated that ROS induces hepatic cell apoptosis and fibrosis via the intrinsic pathway of apoptosis by activating caspase-9 in the mitochondria and then initiates apoptosis by activating caspase-3. Consuming 2.32-23.80 mg/kg·bw/d (150-1500 mg/kg in diet) of BHT effectively improved the plasma and hepatic lipid metabolism, antioxidant response as well as reduced ROS production, protecting hepatic cells from injury. It is implied that even a 10-fold increase of the maximum level of BHT (150 mg/kg) is safe for the largemouth bass.

[Systematic review on orofacial myofunctional therapy to treat obstructive sleep apnea-hypopnea syndrome]

Obstructive sleep apnea-hypopnea syndrome (OSAHS) is an important risk factor for cardiovascular and cerebrovascular diseases. The widespread collapse of the airway, which can't maintain its normal position and structure, is an important cause of OSAHS. Noninvasive ventilator-assisted ventilation is the preferred treatment for OSAHS, but there are shortcomings of poor compliance. Orofacial myofunctional therapy (OMT) is a noninvasive, simple, low-cost, low-risk therapy that is expected to replace noninvasive ventilator-assisted ventilation to a certain extent. So far, there is little Chinese literature on OMT, especially no training methods in Chinese version. Therefore, this paper systematically reviewed anatomical abnormalities and pathology of OSAHS, possible treatment mechanism of OMT and related research progress. And we translated two kinds of training method of OMT (Guimarase's and Hemmat Baz's) into Chinese for researchers and clinicians' reference, which is widely cited in foreign literature.

[Mutant Rad50 enhances killing effects of radiation on nasopharyngeal carcinoma cell line CNE1]

Objective: To investigate the killing effects of radiation and mutant Rad50 transfection on human nasopharyngeal carcinoma cell line CNE1. Methods: The experimental groups included: control group, Ad-Rad50-GFP group, Ad-EGFP group, irradiation group, Ad-Rad50-GFP combined with irradiation group, and Ad-EGFP combined with irradiation group. CNE1 cells were transfected with recombinant adenoviral vector Ad-Rad50-GFP carrying mutant Rad50 gene. The expressions of Mre11, Rad50, Nbs1, and relevant constituents composing MRN complex were detected by Western Blot. Neutral comet assay was used to detect the effect of mutant Rad50 on restoration process of DNA damage. Cell growth curve was used to evaluate the growth inhibition of CNE1 by mutant Rad50 and radiation. Results: Expressions of Mre11, Rad50, and Nbs1 in cells of Ad-Rad50-GFP group were less significantly than those in control group when irradiation was completed (0.48 vs 0.62, 0.42 vs 0.5, and 0.53 vs 0.69, respectively, P<0.05) and 24 hours after irradiation (0.41 vs 0.69, 0.46 vs 0.58, and 0.34 vs 0.78, respectively, P<0.05). The mean tail moment (MTM) in Ad-Rad50-GFP plus irradiation group was higher than that in irradiation group when irradiation was completed (16.06 vs 14.8, P<0.05), 24 hours after irradiation (58.23 vs 15.89, P<0.05) and 48 hours after irradiation: (45.12 vs 11.42, P<0.05). Seven days after irradiation, the cells in Ad-Rad50-GFP plus irradiation group was less than those in control group or irradiation group (both P<0.05). Conclusion: Mutant Rad50 enhances killing effects of radiation on nasopharyngeal carcinoma cell line CNE1.

Scorpion Venom Heat-Resistant Peptide Protects Transgenic Caenorhabditis elegans from β-Amyloid Toxicity

Scorpion venom heat-resistant peptide (SVHRP) is a component purified from Buthus martensii Karsch scorpion venom. Our previous studies found SVHRP could enhance neurogenesis and inhibit microglia-mediated neuroinflammation in vivo. Here, we use the transgenic CL4176, CL2006, and CL2355 strains of Caenorhabditis elegans which express the human Aβ_1-42 to investigate the effects and the possible mechanisms of SVHRP mediated protection against Aβ toxicity in vivo. The results showed that SVHRP-fed worms displayed remarkably decreased paralysis, less abundant toxic Aβ oligomers, reduced Aβ plaque deposition with respect to untreated animals. SVHRP also suppressed neuronal Aβ expression-induced defects in chemotaxis behavior and attenuated levels of ROS in the transgenic C. elegans. Taken together, these results suggest SVHRP could protect against Aβ-induced toxicity in C. elegans. Further studies need to be conducted in murine models and humans to analyze the effectiveness of the peptide.

The expression and significance of WT1 in xenotransplanted ovarian carcinoma treated by paclitaxel

In this study, the authors investigated the expression and significance of WTl in xenotransplanted ovarian carcinoma cell SKOV3 of nude mice treated with paclitaxel. Xenotransplanted ovarian carcinoma was established in nude mice using the SKOV3 cell line. The mice were randomized into the treatment group with paclitaxel and control group with normal sodium. The sizes of the xenotransplanted tumors were measured and the tumor specimens were confirmed by routine hemotoxylin-eosin (H&E) staining. The apoptosis index was then assayed using flow cytometry. WTl and bcl-2 expression were detected with immunohistochemistry, and WT1 mRNA expression was determined by reverse transcriptase polymerase chain reaction (RT-PCR). The authors found that the growth of the xenotransplanted tumor was inhibited by paclitaxel therapy. Compared to the control group, the apoptosis rate was significantly increased in the treatment group (p < 0.05). At the same time, the expression of WTl, bcl-2 and WTI, mRNA were significantly decreased in the paclitaxel therapy group (p < 0.05). The authors conclude that the WTl gene may play an important role during apoptosis of ovarian carcinoma and the mechanism may be closely related to bcl-2.

Metabolic response of maize plants to multi-factorial abiotic stresses

Clarification of the metabolic mechanisms underlying multi-stress responses in plants will allow further optimisation of crop breeding and cultivation to obtain high yields in an increasingly variable environment. Using NMR metabolomic techniques, we examined the metabolic responses of maize plants grown under different conditions: soil drought, soil salinity, heat and multiple concurrent stresses. A detailed time-course metabolic profile was also performed on maize plants sampled 1, 3 and 7 days after initiation of soil drought and heat stress. The metabolic profile of maize plants subjected to soil drought was more similar to plants exposed to salt stress than to heat-stressed plants. Drought-stressed maize plants subjected to salt or heat stress showed distinct integrated metabolic profiles compared with those exposed to either stressor individually. These differences show the considerable metabolic plasticity of maize in response to different growth conditions. Moreover, glucose, fructose, malate, citrate, proline, alanine, aspartate, asparagine, threonine and one unknown compound fluctuated obviously between maize plants grown in controlled growth cabinet and a natural regime. These changes were associated with the TCA cycle and core nitrogen metabolism, and could be related to their multiple functions during plant growth. The evident stress-induced trajectory of metabolic changes in maize indicated that the primary metabolic responses to soil drought, heat and combined drought and heat stresses occurred in a time-dependent manner. Plasticity at the metabolic level may allow maize plants to acclimatise their metabolic ranges in response to changing environmental conditions.

Scorpion Venom Heat-Resistant Peptide Attenuates Glial Fibrillary Acidic Protein Expression via c-Jun/AP-1

Scorpion venom has been used in the Orient to treat central nervous system diseases for many years, and the protein/peptide toxins in Buthus martensii Karsch (BmK) venom are believed to be the effective components. Scorpion venom heat-resistant peptide (SVHRP) is an active component of the scorpion venom extracted from BmK. In a previous study, we found that SVHRP could inhibit the formation of a glial scar, which is characterized by enhanced glial fibrillary acidic protein (GFAP) expression, in the epileptic hippocampus. However, the cellular and molecular mechanisms underlying this process remain to be clarified. The results of the present study indicate that endogenous GFAP expression in primary rat astrocytes was attenuated by SVHRP. We further demonstrate that the suppression of GFAP was primarily mediated by inhibiting both c-Jun expression and its binding with AP-1 DNA binding site and other factors at the GFAP promoter. These results support that SVHRP contributes to reducing GFAP at least in part by decreasing the activity of the transcription factor AP-1. In conclusion, the effects of SVHRP on astrocytes with respect to the c-Jun/AP-1 signaling pathway in vitro provide a practical basis for studying astrocyte activation and inhibition and a scientific basis for further studies of traditional medicine.

Bromate oxidized from bromide during sonolytic ozonation

Sonolytic ozonation (US/O3) is an effective way to degrade many pollutants in drinking water as the elevated mass transfer rate of ozone gas and the enhanced forming of hydroxyl radicals (OH). This work investigated the formation of bromate (BrO3(-)) from bromide (Br(-)) in sonolytic ozonation. At neutral pH, the bromate conversion rate ([BrO3(-)]/[Br(-)]0) was increased to 60% by ultrasound at continuous ozone flow (0-0.2Lmin(-1)), much higher than that without ultrasound or without bubbling. This indicates that the promoting effect of sonolysis on BrO3(-) formation is mainly due to the sonolytic decomposition of ozone and the enhancement of gas-liquid transfer. The [BrO3(-)]/[Br(-)]0 was increased with increasing pH. In addition, the reduction of HOBr/OBr(-) with ultrasound demonstrates that bromate may be inhibited as the bromide was formed with the H2O2 generation under ultrasound. This suggests the competition between bromate and bromide during the US/O3 led to the inhibition of bromate formation at high ozone flow. Therefore, our result reveals that the bromate formation under ultrasound is improved remarkably in US/O3 in quick treatment with proper ozone flow (<0.2Lmin(-1)).

Single-photon property characterization of 1.3 μm emissions from InAs/GaAs quantum dots using silicon avalanche photodiodes

We developed a new approach to test the single-photon emissions of semiconductor quantum dots (QDs) in the optical communication band. A diamond-anvil cell pressure device was used for blue-shifting the 1.3 μm emissions of InAs/GaAs QDs to 0.9 μm for detection by silicon avalanche photodiodes. The obtained g⁽²⁾(0) values from the second-order autocorrelation function measurements of several QD emissions at 6.58 GPa were less than 0.3, indicating that this approach provides a convenient and efficient method of characterizing 1.3 μm single-photon source based on semiconductor materials.

Diabetic retinopathy in predicting diabetic nephropathy in patients with type 2 diabetes and renal disease: a meta-analysis

AIMS/HYPOTHESIS

The aim of this meta-analysis is to determine the predictive value of diabetic retinopathy in differentiating diabetic nephropathy from non-diabetic renal diseases in patients with type 2 diabetes and renal disease.

METHODS

Medline and Embase databases were searched from inception to February 2012. Renal biopsy studies of participants with type 2 diabetes were included if they contained data with measurements of diabetic retinopathy. Pooled sensitivity, specificity, positive predictive value, negative predictive value and other diagnostic indices were evaluated using a random-effects model.

RESULTS

The meta-analysis investigated 26 papers with 2012 patients. The pooled sensitivity and specificity of diabetic retinopathy to predict diabetic nephropathy were 0.65 (95% CI 0.62, 0.68) and 0.75 (95% CI 0.73, 0.78), respectively. The pooled positive and negative predictive value of diabetic retinopathy to predict diabetic nephropathy were 0.72 (95% CI 0.68, 0.75) and 0.69 (95% CI 0.67, 0.72), respectively. The area under the summary receiver operating characteristic curve was 0.75, and the diagnostic odds ratio was 5.67 (95% CI 3.45, 9.34). For proliferative diabetic retinopathy, the pooled sensitivity was 0.25 (95% CI 0.16, 0.35), while the specificity was 0.98 (95% CI 0.92, 1.00). There was heterogeneity among studies (p < 0.001), and no publishing bias was identified.

CONCLUSIONS/INTERPRETATION

Diabetic retinopathy is useful in diagnosing or screening for diabetic nephropathy in patients with type 2 diabetes and renal disease. Proliferative diabetic retinopathy may be a highly specific indicator for diabetic nephropathy.

[Spectral analysis of formation of trihalomethanes during reaction of tryptophan with disinfectants]

UV and fluorescence spectra were applied to analyze the characteristics of reaction of disinfectants (free chlorine, free bromine) with tryptophan, as well as the formation of disinfection byproduct-trihalomethanes (THMs). The results show that disinfecting reaction decrease both the intensity and FRI (fluorescence region integration) of tryptophan. A linear relationship was found between the two indexes. Increasing the ratio of free bromine led to a lowering of FRI, a decrease in UV280 and an increase in UV254. Bromine-substitution ratio of THMs also went up with increasing the ratio of free bromine, whereas the total THMs concentration didn't follow such mono-increase pattern. Those phenomena are mainly due to a higher substitution but a lower oxidation capacity of free bromine, when compared with free chlorine. A linear relationship between FRI and CHBr3 concentration was found using free bromine alone, which did not exist by dosing ammonia to change the characteristic of disinfectant.

Confined three-dimensional plasmon modes inside a ring-shaped nanocavity on a silver film imaged by cathodoluminescence microscopy

The confined modes of surface plasmon polaritons in boxing ring-shaped nanocavities have been investigated and imaged by using cathodoluminescence spectroscopy. The mode of the out-of-plane field components of surface plasmon polaritons dominates the experimental mode patterns, indicating that the electron beam locally excites the out-of-plane field component of surface plasmon polaritons. Quality factors can be directly acquired from the spectra induced by the ultrasmooth surface of the cavity and the high reflectivity of the silver (Ag) reflectors. Because of its three-dimensional confined characteristics and the omnidirectional reflectors, the nanocavity exhibits a small modal volume, small total volume, rich resonant modes, and flexibility in mode control.

Short axis contact in the chaining of ellipsoidal particles of polar molecule dominated electrorheological fluid

We simulate the effect of the chaining direction of ellipsoidal particles of polar molecule dominated electrorheological (PM-ER) fluids using commercially available COMSOL Multiphysics® software for the distribution of electric field and the total electrostatic energy. It is proved that adding ferroelectric materials to the channels parallel to the short axis would make the short axis parallel to the field direction when the ellipsoidal particles are chained under an electric field. According to our simulation, while the concentration of the channels stays constant, the greater the dielectric constant of the inserted material, the stronger the maximum local electric field will be.

Gene transfer using recombinant simian virus 40 viral vectors into mice bone marrow progenitor cells depressed the immunogenicity of keratinocyte stem cells

Hematopoietic stem cell (HSC) gene transfer has been attempted almost entirely ex vivo and has been limited by loss of self-renewal capacity and transplantation-related defects in homing and engraftment. Herein we have attempted to overcome these limitations by injecting vectors directly into the bone marrow (BM) to transduce HSCs in their native environment. Simian virus 40 (SV40)-derived gene delivery vectors were used because they efficiently transduce resting CD34+ cells. Neonatal C57BL/6 (H-2b) mice (3 days old) received SV(Nef-FLAG), carrying FLAG marker epitope directly into both femoral marrow cavities. Keratinocyte stem cells (KSCs) were purified at 7 and 14 days after SV40 injection. The KSCs from 10-day-old C57BL/6 mice were designated as controls. Flow cytometric (FCM) analyses indicated that KSCs from transgenic mice showed strong down-regulation of surface immunological molecules CD40, CD80, CD86, and human major histocompatibility complex class I chain-related antigen A (MICA). Mixed lymphocyte reaction (MLR) assays showed that transgenic KSCs depressed allogeneic T-cell proliferation. Immunofluorescence showed transgenic KSCs expressed FLAG for the entire study as well as high levels of transforming growth factor (TGF)-beta and BCL-2. Thus, direct intramarrow administration of recombinant SV40 yielded efficient gene transfer to mice BM progenitor cells. KSCs with low immunogenicity may be obtained for further investigations of skin transplantation immunity.

[Effects of scorpion venom heat-resistant protein on kainic acid induced-damage of cultured primitive rat hippocampal neuropeptide Y-nergic neurons]

AIM

To investigate the effects of scorpion venom heat-resistant protein (SVHRP) on kainic acid induced-damage of cultured primitive rat hippocampal neuropeptide Y-nergic neurons.

METHODS

We observed morphological changes, celluar vigor, NPY-immunoreactivity and NPY mRNA expression by means of Thionine staining, MTT assay, immunocytochemistry and RT-PCR, respectively, on the primitively cultured Sprague-Dawley rat hippocampal neuron treated with KA and SVHRP for 24 h.

RESULTS

MTT assay and morphologic analysis showed that SVHRP markedly increased neuron survival-rate, and protected them from kA-induced damage. The expression of NPY-immunoreactivity and NPY mRNA in SVHRP group increased obviously compared with other groups.

CONCLUSION

SVHRP protected the primitively cultured hippocampal neurons from KA-induced neuroexcitotoxicity and promoted the expression of NPY.

X-ray Flares from Postmerger Millisecond Pulsars

Recent observations support the suggestion that short-duration gamma-ray bursts are produced by compact star mergers. The x-ray flares discovered in two short gamma-ray bursts last much longer than the previously proposed postmerger energy-release time scales. Here, we show that they can be produced by differentially rotating, millisecond pulsars after the mergers of binary neutron stars. The differential rotation leads to windup of interior poloidal magnetic fields and the resulting toroidal fields are strong enough to float up and break through the stellar surface. Magnetic reconnection-driven explosive events then occur, leading to multiple x-ray flares minutes after the original gamma-ray burst.

The role of microglia in paraquat-induced dopaminergic neurotoxicity

The herbicide paraquat (PQ) has been implicated as a potential risk factor for the development of Parkinson's disease. In this study, PQ (0.5-1 microM) was shown to be selectively toxic to dopaminergic (DA) neurons through the activation of microglial NADPH oxidase and the generation of superoxide. Neuron-glia cultures exposed to PQ exhibited a decrease in DA uptake and a decline in the number of tyrosine hydroxylase-immunoreactive cells. The selectivity of PQ for DA neurons was confirmed when PQ failed to alter gamma-aminobutyric acid uptake in neuron-glia cultures. Microglia-depleted cultures exposed to 1 microM PQ failed to demonstrate a reduction in DA uptake, identifying microglia as the critical cell type mediating PQ neurotoxicity. Neuron-glia cultures treated with PQ failed to generate tumor necrosis factor-alpha and nitric oxide. However, microglia-enriched cultures exposed to PQ produced extracellular superoxide, supporting the notion that microglia are a source of PQ-derived oxidative stress. Neuron-glia cultures from NADPH oxidase-deficient (PHOX-/-) mice, which lack the functional catalytic subunit of NADPH oxidase and are unable to produce the respiratory burst, failed to show neurotoxicity in response to PQ, in contrast to PHOX+/+ mice. Here we report a novel mechanism of PQinduced oxidative stress, where at lower doses, the indirect insult generated from microglial NADPH oxidase is the essential factor mediating DA neurotoxicity.

[Study on differentially expressed genes of ulcerative colitis in the rat treated by herbs-partitioned moxibustion]

OBJECTIVE

To probe the mechanism of herbs-partitioned moxibustion for treatment of ulcerative colitis.

METHODS

The rats with ulcerative colitis were randomly divided into 3 groups, normal control group, model group, and herbs-partitioned moxibustion group. The rats in the herbs-partitioned moxibustion group were treated by herbs-partitioned moxibustion at bilateral Tianshu (ST 25). BiostarR-40s gene chip was applied to detect the differentially expressed gene of their colonic tissues and fluorescence quantitative polymerase chain reaction was employed to confirm the results of the microarray analysis with interleukin-1 beta messenger RNA (IL-1beta mRNA) expression.

RESULTS

Of 174 differential expression genes identified, 28 genes (including 7 known genes) elevated in rats of ulcerative colitis were down-regulated and 146 genes (including 42 known genes) reduced in the rat of ulcerative colitis were up-regulated after herbs-partitioned moxibustion treatment.

CONCLUSION

Many abnormally expressed genes are involved in occurrence of ulcerative colitis and herbs-partitioned moxibustion can regulate expression of IL-1beta and other genes to exert therapeutic effect.

Gene cloning, expression and vaccine testing of Schistosoma japonicum SjFABP

A 600 bp DNA fragment was amplified by PCR from an adult Schistosoma japonicum cDNA library. Sequence analysis confirmed that this fragment contained an S. japonicum Chinese mainland strain fatty acid binding protein (Sj14FABP) gene. This gene was subsequently expressed in Escherichia coli (E. coli) and in Baculovirus/silkworm systems. The recombinant protein from E. coli was a 41 kDa GST fusion protein (rSj14/GST), which could be purified by glutathione agarose affinity chromatography, with a yield of 25 mg/L E. coli culture. The recombinant protein from the Baculovirus/silkworm system was an 18 kDa fusion protein (rSj14/His), which could be purified by Ni-NTA resin chromatography column with a yield of 3.5 mg per silkworm larva. Both rSj14/GST and rSj14/His could be recognized by S. japonicum-infected mouse sera and anti-rSj14/GST mouse sera in Western blotting. The purified recombinant protein was immunogenic in mice, rats and sheep, and 34.3%, 31.9% and 59.2% worm reductions, respectively, were obtained in vaccinated Kunming mice, Wistar rats and sheep vaccinated with Sj14/GST, compared to non-vaccinated control groups. Worm reductions of 48.8% and 49.0% were recorded in Balb/c mice immunized with Sj14/His, compared to non-vaccinated and BCG-vaccinated groups, respectively. These results indicate that rSj14FABP is a promising candidate vaccine for schistosomiasis japonica, particularly as in the rat and sheep vaccination experiments, no adjuvant was used.

[Studies on the sex difference in proteins between male and female adult worm of Schistosoma japonicum]

OBJECTIVE

To explore the sex difference in proteins between male and female adult worm of Schistosoma japonicum.

METHODS

Two-electrophoresis was used to analyse the difference of protein between the male and female adult worm of S. japonicum (Chinese strain).

RESULTS

Two-dimensional electrophoresis analysis revealed that at the site of 43 kDa and an isoelectric point (pI) of 5.60-5.90 the male worm exhibited a band carrying a number of spots and dots, being longer and wider than that exhibited by the female worm. The female worm exhibited 7 specific dots.

CONCLUSION

The sex differences in proteins between male and female adult worms of S. japonicum are significant.

[Cloning and expression of gynecophoral canal protein gene of Schistosoma japonicum (Chinese strain)]

A 1949 bp cDNA fragment was amplified by RT-PCR from adult Schistosoma japonicum (Chinese strain) mRNA with 3 pair of primers that were designed according to published SmGCP gene encoding gynecophoral canal protein of Schistosoma mansoni and SjGCP1 gene encoding the conservative region of gynecophoral canal protein of Schistosoma japonicum. Sequence analysis indicated that this fragment, named SjGCP, with 85% identity to SmGCP, contained a complete open reading frame (ORF) of gynecophoral canal protein gene of Schistosoma japonicum (Chinese strain). The amino acid sequence shared 83.7% identity with gynecophoral canal protein of Schistosoma mansoni. This fragment was cloned into the expression vector pET28c(+) and subsequently expressed in Escherichia coli. SDS-PAGE revealed that the molecular weight of this expressed product was 80 kD. Western blotting showed that the recombinant protein reacted well with the rabbit serum immunized with Sj worm antigen, indicating that this expressed product had good antigenicity.

[The hemolytic site of the basic phospholipase A(2) from Agkistrodon halys pallas]

The gene of the basic phospholipase A(2) from Agkistrodon halys Pallas (BPLA(2) )was mutated site-directedly by polymerase chain reaction (PCR) and the residue Arg(34) of the encloding protein was substituted by Glu and Gln respectively. The mutant gene has been cloned into the expression vector pBLMVL2 and has been expressed in E.coli RR1 effectively. The protein was produced as insoluble inclusion bodies. After partial purification, the inclusion bodies were denatured and renatured into active form, and the renatured recombinant protein was purified by gel-filtration. The expression product has the same enzymatic activity as the denatured-refolded BPLA(2) and its hemolytic activity dropped distinctly, which suggest that the basic residue Arg(34) of BPLA(2) is a crucial amino acid residue during the process of hemolysis.

[Separation and determination of pseudoephedrine in bufferin cold tablet by capillary electrophoresis with hydropropyl-beta-cyclodextrin as chiral selective reagent]

A method for the separation and analysis of the chiral pseudoephedrine enantiomers using capillary electrophoresis was established. The buffer solution for separation was 25 mmol/L Tris-phosphate, including 38 mmol/L hydropropyl-beta-cyclodextrin with pH value of 2.65. (1S, 2S)(+) Pseudoephedrine in Bufferin Cold tablet was determined. The method has good precision, recovery and linear relationship.

[Cloning of secondary lymphoid-tissue chemokine (SLC) and its expression in prokaryotic system]

The total RNA from lymphoid tissue in Chinese was extracted, and the gene encoding the mature peptide of secondary lymphoid-tissue chemokine (SLC) was cloned by RT-PCR. Nucleotide sequence analysis showed that there is only one nucleotide different from that reported, but it doesn't alter the amino acid encoded. The SLC cDNA was inserted into an expression vector pET-28a(+) under T7 promoter and constructed recombinant plasmid pET28a-SLC. pET28a-SLC was transformed to E. coli BL21(DE3) and the expression strain was gotten. After inducing with IPTG for 3-5 hours the bacterium were sonicated. After centrifuging the supernatant was analysed by SDS-PAGE. An obvious expression band about 18 kD can be seen. The expressed product was purified by Ni2+ affinity chromatography column, and the purity is up to 90 percent.