Beauty of Chromatin Structure: Chromatin Accessibility / 中国生物化学与分子生物学报

Chromatin accessibility is one of the important indicators to evaluate the stability of chromatin structure, which is used to evaluate the binding ability of chromatin binding factors to chromosome DNA. It plays an important role in different nuclear processes, including gene transcription regulation and DNA damage repair. Abnormal regulation of chromatin accessibility is closely related to the occurrence and development of a variety of diseases, including tumors and neurodegenerative diseases. Therefore, exploration of this attribute has become a hot spot in the field of life science and disease. More and more new technologies came into being, such as chromatin conformation capture, high-throughput sequencing, and the combination of these two technologies. With the progress of technology, more and more factors involved in the regulation of chromosome accessibility have been found and summarized, including nucleosome occupation, histone modification and non-coding RNA. A number of large-scale genomic data have drawn the chromatin accessibility map of a variety of diseases, which provides data support for revealing the relationship between the occurrence and development of diseases and chromatin accessibility. Meanwhile, with the development of single-cell chromatin accessibility sequencing technology, the investigation for division of cell types at chromatin level was achieved, which makes up for the deficiency of solely relying on gene expression for cell type division. This review will explain the development and prospect of the research about chromatin accessibility from the aspects of chromatin composition and accessibility, factors affecting chromatin accessibility, detection methods of chromatin accessibility, and its roles in cancer, briefly.

Chemical Compositions and Antioxidant Activity of Volatile Oils from Doellingeria scaber / 中国实验方剂学杂志

Objective: To identify the chemical compositions and conduct relative content analysis of the essential oil from wild Doellingeria scaber in high altitude area of Dabie mountains, and investigate its antioxidant capacity. Method: The volatile oil of D. scaber was extracted by simultaneous distillation extraction (SDE) method. Its chemical compositions were analyzed by gas chromatography-mass spectometry (GC-MS), and the relative percentage content of each composition was determined by peak area normalization method. The antioxidant activities of the oil were evaluated by reducing ability method, 1, 1-diphenyl-2-picrylhydrazyl (DPPH) method and β-carotene bleaching assay. Result: A total of 50 components representing 86.91% in this plant were identified. The main chemical compositions were (E)-β-farnesene(20.21%), germacrene D(9.94%), hexadecanoic acid(8.66%), β-terpinene(7.82%), caryophyllene(6.9%) and p-cymen-8-ol(4.48%). The main components of volatile oils include alkenes (56.57%), alcohols (12.24%), fatty acids (11.24%), epoxides(2.93%), esters(1.82%), aldehydes and ketones (1.60%), and aromatics (0.51%). The reduction ability of volatile oil to iron ions increases with the increase of concentration, but the reduction ability is far weaker than that of vitamin C. The 50% inhibiting concentration (IC50) of volatile oil on DPPH free radicals and in β-carotene/linoleic acid lipid system was 0.72 g·L-1 and 0.10 g·L-1, respectively, indicating that the volatile oil had a certain scavenging capacity on DPPH free radicals and a good inhibition effect on lipid peroxidation. Conclusion: GC-MS was used to identify the chemical compositions of the volatile oil from D. scaber, and antioxidant test in vitro showed that D. scaber had certain antioxidant capacity, providing experimental basis for its development and utilization.

Inhibitory effects of Qushuanling Capsule () on thrombus formation and platelet aggregation in rats / 中国结合医学杂志

<p><b>OBJECTIVE</b>To investigate the effects of Qushuanling Capsule ( QSLC) on thrombus formation and platelet aggregation in rats.</p><p><b>METHODS</b>Arteriovenous bypass, venous thrombosis, and middle cerebral artery thrombosis models were used in rats to investigate the anti-thrombotic effects of QSLC, a compound of nine Chinese herbs. The platelet aggregation induced by adenosine diphosphate (ADP), thrombin or arachidonic acid (AA), as well as the contents of thromboxane B(2) (TXB(2)) and 6-keto-prostaglandin F1α (6-keto-PGF1α) in rat plasma and aortic walls, were determined to investigate the possible mechanisms of the anti-thrombotic effects of QSLC.</p><p><b>RESULTS</b>After oral administration with QSLC for 7 days, arteriovenous bypass thrombosis was obviously suppressed compared with the model group, venous thrombosis was also obviously suppressed, rat behaviors were obviously improved, and brain infarct size as well as water content were also reduced. The platelet aggregation induced by ADP or thrombin was inhibited by QSLC, but the drug had no effect on AA-induced platelet aggregation and content of TXB(2) and 6-keto-PGF1α in plasma and the aortic wall.</p><p><b>CONCLUSION</b>These results suggest that QSLC can be used in the prevention and treatment of thrombotic diseases, and that its mechanism of action may be related to inhibition of platelet aggregation.</p>

Puerarin enhances superoxide dismutase activity and inhibits RAGE and VEGF expression in retinas of STZ-induced early diabetic rats

OBJECTIVE@#To investigate the effects of puerarin on the activity of superoxide dismutase (SOD), and expressions of advanced glycation end-product (AGE) receptor (RAGE) and vascular endothelial growth factor (VEGF) in retinas of streptozotocin (STZ)-induced early diabetic rats.@*METHODS@#Diabetic rat models were established by inducing diabetes via intra-peritoneal injection of STZ. Rats were randomly divided into normal (control), diabetic (DM), and DM+ puerarin groups. After intra-gastric administration of puerarin (500 mg/kg/day for 4 weeks), levels of SOD and malondialdehyde (MDA) were determined in serum and retina. mRNA and protein expression levels of RAGE and VEGF in retinas were determined by real-time polymerase chain reaction (RT-PCR) (mRNA) and Western blot analysis (protein levels).@*RESULTS@#There was significantly lower SOD activity and significantly higher MDA in serum and retinas of the DM group compared with the two other groups (P<0.05). After treatment with puerarin, SOD activity increased and MDA content decreased in this group (P<0.05). mRNA and protein expression levels of RAGE and VEGF in the DM group were significantly higher than those of the other groups (P<0.05), and decreased after puerarin treatment (P<0.05).@*CONCLUSIONS@#Puerarin is able to enhance SOD activity, and inhibit RAGE and VEGF expressions in retinas of STZ-induced early diabetic rats.

Therapeutic effect of syringin on adjuvant arthritis in rats and its mechanisms / 药学学报

This study is to investigate the therapeutic effect of syringin on adjuvant arthritis (AA) in rats and its mechanisms. Complete Freund's adjuvant (FCA) was used to induce AA in rats. Secondary paw swelling of AA rats was measured with volume meter. Pain response and polyarthritis index were scored. Meanwhile, splenic lymphocyte proliferation response induced by concanavalin A (ConA) or lipopolysaccharide (LPS) was examined with MTT assay. IL-2 production of splenic lymphocytes and IL-1 beta, TNF-alpha production of peritoneal macrophage (PM phi) were estimated by enzyme linked immunosorbent assay (ELISA). The secondary inflammation of AA rats appeared on the 14th day after injection of FCA. Syringin and tripterygium glycosides (TG) were given by intragastric administration for 16 days from the 14th day. Treatment of AA rats with syringin and TG from the 22th day significantly attenuated the secondary hind paw swelling, as well as relieved the pain response and the polyarthritic symptoms of the whole body as compared with that of the AA model group. The suppressed lymphocyte proliferation and IL-2 production of splenic lymphocytes in AA rats were reversed by treatment with syringin. Meanwhile, syringin remarkably down-regulated IL-1 beta, TNF-alpha productions from PM phi. These results indicate that anti-inflammatory effects of syringin on AA rats are mediated by modulating the immune function of abnormal cells and the balance of cytokines.

Effect of p21-activated kinase-1 on the invasiveness of colorectal carcinoma cells in vitro / 南方医科大学学报

<p><b>OBJECTIVE</b>To observe the effect of p21-activated kinase-1 (PAK1) gene transfection on the invasiveness of human colorectal carcinoma SW480 cells in vitro.</p><p><b>METHODS</b>SW480 cells in routine culture were transfected with the recombinant plasmid EGFP-C1/PAK1 via Lipofectamine(TM) 2000. The expression of PAK1 protein in SW480 cells was detected using Western blotting, and the changes of the invasiveness of SW480 cells were evaluated using Boyden chamber invasion assay.</p><p><b>RESULTS</b>Forty-eight hours after transfection with pEGFP-C1/ PAK1, the PAK1 protein expression increased significantly in comparison with those in negative and vector control groups. The invasiveness of the SW480 cells was significantly enhanced after the transfection.</p><p><b>CONCLUSION</b>The PAK1 gene transfection can increase the expression of PAK1 in SW480 cells and enhance the invasiveness of the cells. PAK1 can be associated with the invasiveness and metastasis of colorectal carcinoma cells.</p>

Effect of ibudilast on apoptosis of airway eosinophil in asthmatic guinea pigs / 药学学报

This study is to investigate the effect of ibudilast on apoptosis of airway eosinophil in asthmatic guinea pigs and its mechanism. Experimental asthma model of guinea pigs was induced with ovalbumin (OVA). Differential count in BALF was examined. The apoptosis of eosinophils (EOS) was labeled with TdT-mediated dUTP nick end labeling (TUNEL) technique. Fas mRNA expression of EOS was detected by reverse transcription-polymerase chain reaction (RT-PCR). The quantification of GM-CSF and IL-5 in BALF was conducted with ELISA. After treatment of ibudilast, the number of EOS and the quantification of GM-CSF and IL-5 decreased significantly. The number of apoptotic cells as well as Fas mRNA expression of EOS obviously increased. The results indicated that anti-asthma mechanisms of ibudilast can antagonize asthma through decreasing the number of EOS, inducing apoptosis of EOS, enhancing Fas mRNA expression of EOS and reducing the content of GM-CSF and IL-5.

Effect of nebulized TFG on Th1/Th2 imbalance in mouse model with asthma / 中国中药杂志

<p><b>OBJECTIVE</b>To investigate the effect of nebulized total ginkgo flavone glycosides (TFG) on Th1/Th2 imbalance in mice with athma.</p><p><b>METHOD</b>Forty-eight BALB/C mice were randomly divided into four groups: group A (control group, n=12); group B (asthmatic model group, n=12); group C (TFG nebulized treated group, n=12); group D (dexamethasone intraperitoneal treated group, n=12). The asthmatic model was established by sensitivity and local activation with Ovalbumin(OVA) and aluminum hydroxide Al(OH)3. TFG (50 g x L(-1), per aerosol per six mice, 30 minutes) was nebulized 20 days after modeling, while dexamethasone (1 g x L(-1)) was intraperitoneal once daily for 10 days. Perfusate of bronchoalveolar lavage fluid(BALF) was collected on day 32. The level of IL-4, IFN-gamma in BALF, and the level of total IgE in serum was determined. The airway inflammation pathology change and the expression of GATA-3 protein in lungs was detected by immunohistochemical staining.</p><p><b>RESULT</b>Compared with model group, the decreased content of IL-4(49.30 +/- 7.95) ng x L(-1) and increased level of IFN-gamma (49.08 x 5.46) ng x L(-1). were found in BALF, and the level of total IgE (9.47 +/- 1.52) microg x L(-1) in serum also decreased in TFG treated group. In model group, smooth muscle hypertrophing, mucous hyperemia, mucous layer thickening, and inflammatory cell in filtration were observed. Phlegmasia was appeared in the bronchi, which was filled with lots of mucus. In contrast, the inflammatory reaction in TFG and Dexamethasone treated group was less obvious. Expression of GATA-3 was markly increased in model group with decreased expression in TFG treated group.</p><p><b>CONCLUSION</b>Nebulized TFG showed a therapeutic effect for asthmatic mice, the mechanism may be explained by blockingnnnn GATA-3 expression and regulating the disorder Th1/Th2 imbalance.</p>

Purification of total flavonoid glycosides from Hypericum perforatum by macroporous adsorption resin with on-line detection system / 中国中药杂志

<p><b>OBJECTIVE</b>To design a macroporous resin chromatography system with on-line detector which can be used to purify total flavonoid glycosides from Hypericum perforatum.</p><p><b>METHOD</b>Compared with the present detection methods, the ultraviolet detector which can be applied to flow liquid, and a self-made shunt were applied to design the on-line detection system. This system was successfully applied to purify the total flavonoid glycosides from H. perforatum.</p><p><b>RESULT</b>This on-line detection system was simple and feasible, and the results were accurate and reliable. The purity of total flavonoid glycosides from H. perforatum. separated by this system was higher than 90%.</p><p><b>CONCLUSION</b>This technique provides a simple and reliable on-line detection method for industrial chromatography purification of TCM extracts, which is the basis of automatic manufactory of TCM purification.</p>

Cloning of human migfilin N-terminal domain and preparation of anti-migfilin polyclonal antibody / 南方医科大学学报

<p><b>OBJECTIVE</b>To clone migfilin-N terminal sequence into E.coli and obtain a fusion protein for preparing rabbit polyclonal antibody against migfilin, thereby facilitating the study of the role of migfilin in the biological behavior of colon cancer.</p><p><b>METHODS</b>Based on human migfilin cDNA sequence, a pair of primers was designed to amplify migfilin-N terminal sequence by PCR. The PCR product was subcloned into the bacterial expression vector pGEX-4T-1 with EcoRI/XhoI sites, and the target recombinant plasmids were identified with enzymatic cleavage followed by DNA sequence analysis. By transforming the expression vector into component E.coli BL(21) cells, the GST-migfilin-N fusion protein was expressed with IPTG induction. Glutathione-sepharose beads were used to purify the fusion protein, and anti-migfilin polyclonal antibody was produced by immunization of rabbits with the purified GST-migfilin N-terminal fusion protein. The resultant anti-migfilin polyclonal antibody was purified by protein A beads and used for Western blotting for detecting migfilin expression in different cell lines.</p><p><b>RESULTS AND CONCLUSION</b>The migfilin-N terminal gene fragment was cloned successfully, and purified GST-migfilin N-terminal fusion protein and anti-rabbit migfilin polyclonal antibodies were obtained. Western blot analysis demonstrates that the antibodies specifically detected migfilin expression in the cell lines, which may facilitate further investigation of the role of migfilin in the biology of colon cancer.</p>

Effect of total flavonoid in leaves of Ginkgo biloba on the apoptosis of eosinophil in broncho alveloar lavage fluid / 药学学报

This study was to investigate the effect of total flavonoid in leaves of Ginkgo biloba (total flavonoid in leaves of Ginkgo biloba, FG) on the apoptosis of eosinophils (EOS) in broncho alveloar lavage fluid (BALF) of asthma mice. Mouse asthma model was established by ovalbumin (OVA) challenge methods. After atomizing therapy for two weeks, differential count in BALF, morphological change and proportion of apoptosis were detected by AO/EB stain and Annexin V-FITC/PI. The number of total leucocytes and eosinophils in BALF decreased obviously after FG treatment. Compared with model group, the number and proportion of EOS apoptosis increased significantly after FG treatment. The results indicated that one of the anti-inflammation mechanisms of FG might be promoting apoptosis of eosinophils.

Cloning of tight junction protein claudin-1 and construction of the mammalian expression vector / 南方医科大学学报

<p><b>OBJECTIVE</b>To construct a recombinant plasmid containing the coding region of tight junction protein claudin-1 gene to understand the functional role of claudin-1 in human colorectal carcinoma.</p><p><b>METHODS</b>The total RNA was extracted using Trizol from human colorectal carcinoma cell line SW620, and the DNA for claudin-1 was obtained by means of RT-PCR. The PCR product was inserted into the plasmid pEGFP-C1 after restriction endonuclease digestion and ligation. The recombinant plasmid was then transfected into human colorectal carcinoma cell line SW480.</p><p><b>RESULTS</b>The sequence of the recombinant plasmid was verified by restriction endonuclease and DNA sequence analysis, and the target protein expression was detected mostly on the cell membrane.</p><p><b>CONCLUSION</b>The expression vector claudin-1/pEGFP-C1 has been constructed successfully and the target protein can be expressed in human colorectal carcinoma cell line.</p>

Apoptosis induced by the C21 sterols in Baishouwu and its mechanism of action in hepatoma / 药学学报

This study is to investigate the effect of the C21 sterols on inducing apoptosis of hepatocellular cancer cells and its potential mechanism. The transplanted model of hepatoma substantiality (Heps) was established in mice, and the mice were divided into four groups: negative controls group and C21 sterols groups (10, 20, 40 mg x kg(-1)) , treated with drugs separately once a day for 9 days. Then the mice were sacrificed, the tumor growth inhibition rate (IR) was calculated and tumor tissue samples were taken and examined under electron microscope. The tumor cells were harvested and cell viability or apoptosis was analyzed by acridine orange and ethidium bromide (AO/EB) stain. B-cell lymphoma/leukemia-2 gene (bcl-2) in tumor cells was inspected by immunohistochemistry. After treatment with C21 sterols (10, 20, 40 mg x kg(-1)), inhibitory effect on the transplanted Heps was observed. The IR was 34.79%, 47.08% and 50.23%, respectively. Apoptosis induced by the C21 sterols was observed, low growth density and some apoptotic cells were observed in tumor under the electron microscope. The expression of bcl-2 gene on tumor cells decreased in the C21 sterols groups, but the percentage of positive area is higher in 40 mg x kg(-1) group than that in 20 mg x kg(-1) group, which differed from apoptosis results. Inhibiting the excessive expression of bcl-2 gene to promote apoptosis may be one of anti-tumor mechanisms for the C21 sterols in Baishouwu.

Experimental study on effect of Shenling Yigan Granule in antagonizing duck hepatitis B virus / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To study the viral inhibitory effect of Shenling Yigan Granule (SYG) on duck hepatitis B virus (DHBV) in vivo.</p><p><b>METHODS</b>Chongqing ducks infected with DHBV were used. They were randomly divided into five groups, the small-, medium- and high-dose (1.6 g/kg, 3.2 g/kg, 6.4 g g/kg) SYG groups, the lamivudine positive control group, and the model group. The changes of serum DHBV-DNA, DHB-sAg contents and hepatic pathology were observed.</p><p><b>RESULTS</b>The serum content of DHBV-DNA in the three SYG groups and the positive control group was significantly decreased (P < 0.05), while it was rebounded in the latter at day 7 after stopped lamivudine administration. The change of DHBsAg level was insignificantly in all groups. And the hepatic pathological change in the SYG groups and positive control group was slighter than that in the model control group, but showed insignificant difference in comparison between the SYG groups and the model group (P > 0.05).</p><p><b>CONCLUSION</b>SYG has certain in vivo inhibitory effects on DHBV-DNA.</p>

Cloning of human PAK6 cDNA, preparation of anti-PAK6 polyclonal antibody and PAK6 expression in prostate cancer / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the role of PAK6 in prostate cancer by cloning PAK6-N terminal sequence into E.coli and preparing its polyclonal rabbit antibody to detect PAK6 expression in prostate cancer.</p><p><b>METHODS</b>Based on human PAK6 cDNA sequence, we designed a pair of primers to amplify the PAK6-N terminal sequence by PCR. The PCR product was subcloned into the bacterial expression vector pGEX-4T-1 via EcoRI/XhoI sites, and the recombinant plasmids were identified by enzymatic cleavage followed by DNA sequence analysis. By transforming the expression vector into component E.coli BL21 cells, the GST-PAK6-N fusion protein was expressed with IPTG induction. Glutathione-Sepharose beads were used to purify GST- PAK6-N fusion protein. Anti-PAK6 polyclonal antibody was produced by immunizing rabbits with purified GST-PAK6 N-terminal fusion protein. Anti-PAK6 polyclonal antibody was purified by protein A beads and used for detection of PAK6 expression in 3 prostate cancer specimens.</p><p><b>RESULTS AND CONCLUSION</b>We cloned PAK6-N terminal gene fragment successfully, purified GST-PAK6 N-terminal fusion protein, and obtained polyclonal rabbit PAK6 antibody. Immunohistochemistry indicated that PAK6 expressed in the stroma instead of the cancer cells in prostate cancer. All of the 3 prostate cancer specimens showed positive staining in the stroma, suggesting that PAK6 may participate in the stroma-cancer cell interaction in prostate cancer.</p>

Short hairpin RNA-mediated survivin gene silencing inhibits invasion and metastasis of human colon carcinoma cell line SW480 in vitro / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effect of short hairpin RNA (shRNA) targeting survivin on adhesion and invasion of human colon carcinoma cell line SW480 in vitro.</p><p><b>METHODS</b>According to the sequence of the coding region of survivin gene, two strings of 19 nucleotides of inverted sequence flanking the loop sequence of two complementary 9-base oligonucleotides were designed and synthesized to prepare the hairpin construct as the DNA templates for the target shRNA. The shRNA templates were cloned into shRNA expression vector pRNAT-U6.1/Neo, and the resulted vector pRNAT-U6.1/Neo-survivin was transfected into SW480 cells using Lipofectamine 2000. Western blotting was performed to evaluate survivin gene silencing induced by shRNA transfection at the protein level, and the biological behaviors of the SW480 cells were investigated by cell-matrix adhesion, invasion and gelatin-zymography assays.</p><p><b>RESULTS</b>Western blotting revealed significantly lowered survivin protein expression in transfected SW480 cells, and survivin gene silencing induced by shRNA significantly suppressed the metastatic potential of SW480 cells in association with suppressed MMPs activity.</p><p><b>CONCLUSIONS</b>Survivin may play an important role in modulating human colorectal carcinoma cell invasion and metastasis, and survivin gene silencing can inhibit human colorectal cancer cell invasion and the production of MMP-2 and MMP-9. Survivin may affect invasion and metastasis of human colorectal carcinoma cells via regulating the production of MMPs.</p>

Effect of C21 steroidal glycoside from root of Cynanchum auriculatum on D-galactose induced aging model mice / 中国中药杂志

<p><b>OBJECTIVE</b>To study the effect of C21 steroidal glycoside (CSG) from the root of Cynanchum auriculatum from Jiangsu on D-galactose (D-gal) induced aging model mice.</p><p><b>METHOD</b>D-gal aging mouse model was established by cervicodorsal region subcutaneous injection with D-gal once a day for eight successive weeks. The mice in the normal control group (NCG, non-modeled) and the model control group (MCG, modeled but untreated) were treated with 1% CMC-Na. The model mice in the low, middle and high-dose CSG and Vitamin E treated groups were treated with a dose of (10, 20, 40, 100 mg x kg(-1) per day, respectively. The SOD activity, MDA content and telomerase activity in serum, heart, liver and brain tissues of mice were measured.</p><p><b>RESULT</b>CSG could obviously increase the SOD activity and decrease the MDA level in serum, heart, liver and brain tissues in D-gal aging mice (P < 0.01). There was no significant difference between three CSG treated groups and Vitamin E treated groups. In comparison of telomerase activity between MCG and the treated groups, it was shown that there was a significant increase in serum in middle and high dose group, and in heart tissues in CSG and Vit E treated groups, but was not in liver and brain tissue.</p><p><b>CONCLUSION</b>This study demonstrates that CSG can antagonize free radical injury, increase the SOD activity and decrease the MDA content of serum, heart, liver and brain in D-gal aging mice, and increase the telomerase activity in serum and heart tissues but not in liver and brain tissue.</p>

Antitumor effects of nobiletin on Heps and its mechanism / 药学学报

<p><b>AIM</b>To study the inhibitory effect and mechanism of nobiletin on Heps tumor bearing mice.</p><p><b>METHODS</b>Models of Heps tumor bearing mice were established. The inhibitory rates of tumor growth were calculated, the apoptosis morphology of tumor tissue was observed. The T lymphocyte transformation capacity was tested by MTT assay, the TNFalpha and IL-2 production were measured by LDH kits.</p><p><b>RESULTS</b>Nobiletin could significantly inhibit Heps tumor growth. The inhibitory rates were 42.14% - 65.09% (P < 0.01). The morphology of tumor tissues in nobiletin group had typical characters of necrosis and apoptosis through transmission electron microscope. Nobiletin could stimulate T lymphocyte transformation and the production of TNFalpha and IL-2.</p><p><b>CONCLUSION</b>Nobiletin has obvious antitumor effect on Heps, the main mechanism is to enhance the cellular immune function and induce apoptosis of tumor tissue.</p>

Preparation of anti-P21-activated kinase 5 polyclonal antibody and its application in dental germ cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To clone PAK5-N terminal sequence for expression in E. coli to prepare its polyclonal antibody, and examine the role of PAK5 in dental germ cells.</p><p><b>METHODS</b>Based on human PAK5 cDNA sequence, PCR primers were designed to amplify PAK5-N terminal sequence. The PCR product was cloned into the expression vector pGEX-4T-1 EcoRI/XhoI sites, and the recombinant plasmids were identified by agarose gel electrophoresis followed by DNA sequence analysis. The recombinant plasmids were transformed into E. coli BL21 and the expression of GST-fusion protein was induced by IPTG. Glutathione-Sepharose beads were used to purify GST-fusion PAK5-N-terminal fragment. Anti-PAK5 polyclonal antibody was obtained in immunizing rabbits with purified GST-PAK5 N-terminal fusion protein, and the antibodies were purified by protein A beads and used for detection of PAK5 expression in dental germ cells.</p><p><b>RESULTS AND CONCLUSIONS</b>We successfully cloned PAK5-N terminal gene fragment, and achieved protein expression, purification and production of PAK5-NT polyclonal antibody. The results of Western blotting indicated that PAK5 can be highly expressed in the dental germ cells, suggesting that PAK5 may play an important role in biological function of dental germ cells.</p>

Study on the pretreatment of the series of HPD macroporous adsorption resin / 中国中药杂志

<p><b>OBJECTIVE</b>To develop a method for the pretreatment of the series of HPD macroporous adsorption resin (MAR).</p><p><b>METHOD</b>The effect of 2% NaOH to pretreatment of the series of HPD MAR was studied by gas chromatography and UV spectrometery.</p><p><b>RESULT</b>The eluting effect by ethanol was better after the MAR was marinated and eluted by 2% NaOH.</p><p><b>CONCLUSION</b>The pretreatment of the series of HPD MAR was: after marinated and eluted by 2% NaOH, the series of HPD MAR were eluted by ethanol at 2 BV x h(-1) at 60 degrees C for 3-4 bed volumes (BV). At then the UV absorbance of eluate was 0.2-0.5. Benzene was not detected and the other residues less than 10 mg x L(-1) in eluted-MAR by GC. And the MARs match to the standard of medicine.</p>