SEARCH · PubMed Health

Results for “Colorimetry”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,009 records · Page 56Linked to original sources

PubMed1991

[A nonisotopic enzymolysis assay method of phosphatidylinositol kinase].

A nonisotopic enzymolysis assay method of phosphatidylinositol kinase (PIK) has been developed. Phosphatidylinositol 4-phosphate (PIP), phosphorylated from phosphatidylinositol (PI) by PIK was hydrolyzed with phosphainositide-specific phospholipase C. The product, inositol 1, 4-bisphosphate (IP2), was separated from inositol 1-phosphate (IP) with Dowex-1 column chromatography. Then, the IP2 was hydrolyzed by alkaline phosphatase to yield PI, and the PI was determined by colorimetry. The PIK activity was defined as PI nmol/mg protein per min. The recovery was 91%, CV = 6.5%

1-Phosphatidylinositol 4-Kinase↗

PubMed2006

[Study of the construction and function of an eukaryotic expression plasmid of immunotoxin DT390 gene].

AIM: To construct a new recombinant eukaryotic expression plasmid of murine IFN-gamma-inducible protein 10 (mIP10) gene and a truncated diphtheria toxin (DT390) gene and investigate its biological function. METHODS: mIP10 cDNA was cloned from murine liver tissue by RT-PCR and was inserted into eukaryotic expression plasmid SRalpha containing DT390 gene to construct plasmid SRalpha-DT390-mIP10. After being identified with restriction endonucleases digestion analysis and DNA sequencing, the recombinant plasmid was transfected into NIH3T3 cells through PolyFect. The expression of recombinant plasmid was detected by immunofluorescence assay and the bioactivity of mIP10-DT390 in cultured supernatant of the transfected NIH3T3 cells was detected by MTT colorimetry. RESULTS: A new recombinant immunotoxin expression plasmid SRalpha-DT390-mIP10 was constructed successfully and was expressed in NIH3T3 cells. The expressed DT390-mIP10 killed the activated T cells effectively. CONCLUSION: A new recombinant eukaryotic expression plasmid SRalpha-DT390-mIP10 has been constructed and expressed successfully, which is useful in further studying the treatment of cancer and autoimmune diseases.

Animals↗

PubMed2005

[Blocking the escape of leukemic cells from killing of T cell by combining anti-Fas ribozyme and CD80-IgG fusion protein].

OBJECTIVE: To study Fas expression regulation of cytotoxic T lymphocyte(CTL)via anti-Fas ribozyme, increasing of CD80 epitope on the surface of acute myelomonocytic leukemia cells by CD80-IgG fusion protein and their effects on the apoptosis and killing ability against acute myelomonocytic leukemia cells of CTL. METHODS: A hammerhead ribozyme gene targeting the Fas mRNA was synthesized and its expression vector pEGFP-RZ596 was constructed and transfected into the mouse spleen T cells via electroporation. The Fas expression on T cells was detected by RT-PCR and Western bloting. In the meantime the eukaryotic expression vector pcDNA/CD80-IgG was constructed by gene recombinant technique and transfected into ovarian cells of hamster of the line CHO. The CD80-IgG fusion protein was purified from the supernatant of G418-selected CHO cells by Protein G affinity chromatography method. Then allogeneic mixed lymphocytes culture between the mouse spleen T cells transfected with pEGFP-RZ596 and WEHI-3 cells (mouse acute myelomonocyte leukemia cell line) incubated with CD80-IgG fusion protein was performed. The apoptosis rate of the T cells was detected with annexin V-FITC. The proliferation and killing ability in vitro against WEHI-3 cells of the T cells were detected by MTT colorimetry. RESULTS: The luminance of Fas Western bloting results from the mouse spleen T cells negative control, transfected with pEGFPC1 and transfected with pEGFP-RZ596 were separately 1, 0.98 and 0.45 (P < 0.01). After being cocultured with WEHI-3 cells, which has higher expression of Fas ligand (64% +/- 3%), the apoptosis rate and the killing ability against WEHI-3 cells of the mouse spleen T cells transfected with pEGFP-RZ596 were separately 37% and 67%. Whereas that of the mouse spleen T cells negative control and transfected with pEGFPC1 were separately 88%, 84% (P < 0.01) and 32%, 31% (P <0.01). The CD80 positive expression rate of WEHI-3 cells was upregulated from 5.1% +/- 0.4% to 27.4% +/- 2.2% after these cells were preincubated with CD80-IgG fusion protein (P < 0.01). The killing ability of the mouse spleen T cells against WEHI-3 cells preincubated and not preincubated with CD80-IgG fusion protein were separately 64% and 49% (P <0.01), but that of the mouse spleen T cells, which were transfected with pEGFP-RZ596, was further promoted to 82% (P < 0.01) CONCLUSION: The apoptosis of mouse CTL inducing by FasL-Fas pathway could be avoided and the killing ability of mouse CTL against WEHI-3 cells can be significantly promoted at the same time by combining anti-Fas ribozyme and CD80-IgG fusion protein.

Animals↗

PubMed2006

[Neuroprotective effect of BDNF on hypoxia for embryonic rat cortical neurons in vitro].

OBJECTIVE: To investigate the neuroprotective function of BDNF on hypoxic- cultured neurons in vitro. METHODS: The embryonic cerebral cortical neurons of rat were cultured in vitro in hypoxic and non-hypoxic environments and were observed under transmission electron microscope. MTT colorimetry was used to detect the viability of the neurons. Both DAPI colorated measurement and TUNEL methods were used to calculate the percentages of neuron apoptosis. Three groups were designed and compared: Group A - normal control; Group B - exposed to hypoxia; Group C-BDNF intervened (with different dosages and durations) and exposed to hypoxia. RESULTS: The ultrastructural alterations of the hypoxic cultured neurons indicated that hypoxia induced necrosis, apoptosis or both. The neurons were most sensitive to hypoxia at the initial 10 hours. At six hours after hypoxic cultures, Group C had significant greater livability of neurons and less percentages of neuron apoptosis than Group B (P<0.05). CONCLUSION: Hypoxia damages embryonic cerebral cortical neurons of rat in vitro. Extrinsic BDNF plays a neuroprotective role against hypoxic-induced neurotoxicity in vitro.

Animals↗

PubMed2006

[Relationship between paraoxonase 1 55 Met/Leu, paraoxonase 2 148 Ala/Gly genetic polymorphisms and coronary artery disease].

OBJECTIVE: To study the relationships between paraoxonase 1 55 Met/Leu (PON1 55Met/Leu), paraoxonase 2 148 Ala/Gly(PON2 148Ala/Gly) genetic polymorphisms and coronary artery disease(CAD), plasma activities of paraoxonase (PON), total superoxide dismutase (T-SOD), as well as plasma concentration of maleic dialdehyde (MDA). METHODS: The PCR-RFLP method was applied to identify the genetic polymorphisms of PON1 55Met/Leu and PON2 148Ala/Gly, and the colorimetry way was used to detect plasma activities of PON, T-SOD and plasma MDA concentration of 262 CAD patients and 100 controls. RESULTS: Comparing with control, the CAD patient had the obviously lower activities of enzymes PON (349.27+/- 138.36 nmol/min.mL vs 454.75+/- 166.00 nmol/min.mL, P< 0.001) and T-SOD (23.61+/- 16.51 U/mL vs 44.01+/- 22.68 U/mL, P< 0.001) while getting the plasma MDA concentration increased markedly(2.47+/- 0.73 nmol/mL vs2.15+/- 0.55 nmol/mL, P< 0.01). The CAD patient had more LM genotype and M allele of PON1 55Met/Leu(24.8% vs 1.4%, P< 0.001 and 12.4% vs 0.5%, P was 0.001 respectively), GG and AG genotype and G allele of PON2 148 Ala/Gly(11.8% vs 5.0%, P< 0.001; 48.1% vs 24.0%, P< 0.001 and 36.0% vs 17.0%, P< 0.001 respectively) than control did. The activities of plasma PON and T-SOD were lower in individuals with PON??1 55 LM genotype than those with LL genotype(304.73+/- 125.04 vs 394.84+/- 154.87 nmol/min.mL and 24.89+/- 16.14 vs 30.22+/- 21.29 U/mL, P< 0.001 and P< 0.05 respectively). The activity of plasma PON was also lower in individuals with PON2 148 GG/AG genotype than that with AA genotype(281.47+/- 84.70 vs 356.00+/- 145.95 vs 417.34+/- 159.00 nmol/min.mL, P< 0.001). Logistic regression analysis showed that PON1 55 LM genotype (OR 29.08, 95%CI 2.88-294.04, P was 0.004) and M allele(OR 15.17, 95%CI 1.32-174.29, P was 0.029), PON2 148 GG/AG genotype (OR 2.32, 95%CI 1.52-3.54, P< 0. 001) and G allele (OR 3.24, 95%CI 1.38-7.61, P was 0.007) were independent risk factors for CAD. CONCLUSION: The CAD patient has the obviously low activities of plasma PON and T-SOD but on the contrary, get the plasma MDA concentration increased markedly. PON1 55 LM genotype and M allele, PON2 148 GG/AG genotype and G allele are the risk factors for coronary artery disease, and the activity of plasma PON is also markedly reduced in individuals with above genotypes.

Adult↗

PubMed2006

[Immune modulatory effects of mesenchymal stem cells on T lymphocytes in mixed lymphocyte culture].

AIM: To investigate the features of immune modulatory function derived from the interaction of mesenchymal stem cells (MSC) with T lymphocytes in vitro. METHODS: Normal human bone marrow mononuclear cells were isolated by Ficoll-Hypaque density gradient, then ex vivo MSCs were cultured, expanded, and obtained after the third passage. The MSCs were added to the two-way mixed lymphocyte culture (MLC) according to different proportion. On day 3 and 5, proliferation of T lymphocytes in each group of MLC-MSC and ctrl-MLC was measured with MTT colorimetry. The surface phenotypes of T lymphocytes were analyzed by flow cytometry before and after co-culture of MLC with MSC. RESULTS: MLC added with MSC induced dose- and time-dependent inhibition of T lymphocytes proliferation. CD4(+) T cell subsets were not suppressed so obviously as CD8(+) T cell subsets. CD25 expression of T lymphocytes appeared to be lower in MLC-MSC than in ctrl-MLC. But the CD4(+) CD25(+) double positive cells were evidently increased versus control cultures without MSC. The HLA-DR of activated T lymphocytes was slightly decreased compared to the control. CONCLUSION: MSC can significantly suppress T lymphocytes' proliferation, especially CD8(+) T cell subsets (CTL). In addition, it can down-regulate the expression of some special surface marker, such as CD25 and HLA-DR, on the activated T lymphocytes.

Animals↗

PubMed2006

[Immune response and protective efficacy induced by fusion protein ESAT6-CFP10 of M.tuberculosis in mice].

AIM: To study murine humoral and cellular immune response induced by fusion protein ESAT6-CFP10 and to examine its protective efficacy against M. tuberculosis (MTB) in mice. METHODS: BALB/c mice were immunized subcutaneously on the back with fusion protein ESAT6-CFP10 that was transferred to nitro cellulose (NC) membrane beforehand. Stimulation index (SI) of the spleen lymphocytes of the immunized mice was measured by MTT colorimetry. The level of IFN-gamma and IL-2 and CTL upon antigen-specific stimulation were detected. The vaccinated BALB/c mice were intravenously infected with MTB H37Rv (10(5) CFU/mouse). Four weeks later the number of CFU in spleens was determined. RESULTS: The titer of serum specific antibody in BALB/c mice immunized with fusion protein ESAT6-CFP10 was 1:6,400. The SI of fusion protein immunized group (1.90+/-0.15) was significantly higher than that of saline-immunized group (0.9+/-0.15). The level of IFN-gamma and IL-2 induced by the fusion protein was 1.792+/-19 ng/L and 0.211+/-11 ng/L respectively, which was significantly higher than that of saline-immunized group and lower than that of BCG-immunized group. The specific killing activity of splenocytes was 36%. Compared with the saline-immunized mice (bacterial load was 6.51+/-0.13), MTB number (bacterial load was 5.24+/-0.15) was reduced dramatically in the spleens of BALB/c mice immunized with the fusion protein, but the protective efficacy of the mice immunized with BCG was higher than that of ESAT6-CFP10 vaccinated group. CONCLUSION: Fusion protein ESAT6-CFP10 can be used as a candidate for novel vaccines.

Animals↗

PubMed2006

[Anti-tumor effect of monkshood polysaccharide with adriamycin long circulating temperature-sensitive liposome and its mechanism].

AIM: To observe the synergic action of monkshood polysaccharide (MPS) and adriamycin (ADM) long circulating temperature-sensitive liposome (ALTSL) in targeting therapy for H22 tumor-bearing mice and explore the mechanism. METHODS: The anti-tumor activity was evaluated by using the tumor's weight as an index. The life prolongation rate of mice was calculated according to the survival time of the tumor-bearing mice. The killer activity of NK cells and the lymphocyte transformation rate were detected by the LDH release assay and MTT colorimetry, respectively. The apoptosis of tumor cells and the expressions of p53, Fas, Fas-L and caspase-3 were analyzed by flow cytometry. The expressions of IL-2 mRNA and IL-12 mRNA in spleen lymphocytes were determined by RT-PCR. The pathologic changes of tumor, heart, liver and kidney tissues of the tumor-bearing mice were observed under light microscope. RESULTS: Compared with the adriamycin liposome group, the anti-tumor effects were enhanced in (MPS+ALTSL) group with tumor growth inhibitory rate up to 80.4%. The survival time of the tumor-bearing mice in ALTSL and (MPS+ALTSL) groups was significantly prolonged compared with the ADM group (P<0.01). The killer activity of NK cells was higher in ALTSL group than in the NS and ADM groups, and was highest in (MPS+ALTSL) group. The lymphocyte transformation rate of (MPS+ALTSL) group was markedly increased (P<0.01) as compared with the ADM group. The result of RT-PCR indicated that the expressions of IL-2 mRNA and IL-12 mRNA in lymphocytes in the adriamycin long circulating liposome (ALCL) group were significantly higher than those in the ADM group. Expressions of IL-2 mRNA and IL-12 mRNA was much higher in (MPS+ALTSL) group than in ALTSL group. The pathological examination indicated that in (MPS+ALTSL) group, more lymphocytes and monocytes were found in tumor tissue. CONCLUSION: ALTSL can increase the anti-tumor effect and decrease the side-effects (such as the cytotoxicity) of ADM. MPS combined with ALTSL can enhance killer activity of NK cells and transformation of T cells, supporting their synergic anti-tumor effect.

Aconitum↗

PubMed2006

[Knockdown of Hsp701A induces K562 cells apoptosis by RNA interference].

AIM: To investigate the apoptosis of K562 cells induced by RNA interference(RNAi) targeting Hsp701A. METHODS: Small interference RNA (siRNA) targeting Hsp701A was generated and its eukaryotic expression vectors was constructed and transected into K562 cells. Proliferation, apoptosis and cell cycle of the transected cells was respectively detected by MTT colorimetry and FCM. RESULTS: The eukaryotic expression vector of siRNA against Hsp701A was successfully constructed and transfected into K562 cells, which markedly decreased the expression of Hsp701A on both mRNA and protein level. K562 cells transfected with the vector exhibited slower proliferation, increased apoptosis and increased G(0)/G(1) arrest. CONCLUSION: The inhibition of Hsp701A gene by RNAi may provide a foundation for the development of novel therapeutic strategy for chronic granulocyte leukemia (CML).

Apoptosis↗

PubMed2006

[Expression and analysis of biological activity of wild-type and mutant interleukin-13 in E.coli].

AIM: To express recombinant wild-type human interleukin-13 (rhIL-13) and mutant interleukin-13 (rhIL-13') in E.coli BL21 (DE3) and get active proteins through purification and renaturation. METHODS: IL-13 and IL-13' gene fragments were amplified by PCR and site-directed mutagenesis PCR, respectively and then were inserted into expression vector pET30a(+). Recombinant plasmids were transformed to E.coli BL21 (DE3) and were expressed under IPTG induction. Expressed products were purified through Ni-NTA chromatographic column. The purified proteins were renatured by GSH-GSSG (reduced glutathione, oxidized glutathione) system and dialysis and their bioactivity was detected by MTT colorimetry. RESULTS: The expressed recombinant proteins existed in the form of inclusion body with relative molecular mass about 17 000. The recombinant proteins with higher purity were obtained after purification. The renatured inclusion bodies were biologically active. CONCLUSION: rhIL-13/rhIL-13' with biological activity have been obtained successfully, which lays the foundation for further study on their function.

Blotting, Western↗

PubMed2006

[Increased sensitivity to chemotherapeutic drug by RNAi targeting Hsp701A in HepG2 cells].

AIM: To investigate the effects on chemotherapeutic sensitivity to the drugs of tumor cells induced by Hsp701A targeting siRNA expression vector. METHODS: Specific small interference RNA (siRNA) targeting Hsp701A gene was generated and its eukaryotic expression vector was constructed and transfected into human HepG2 cells.Sensitivity to the chemotherapeutic drug of HepG2 cells transfected with the vector was detected by MTT colorimetry. RESULTS: The eukaryotic expression vector of siRNA targeting Hsp701A was successfully constructed and transfected into human HepG2 cells. Sensitivity to the chemotherapeutic drug of HepG2 cells was increased after Hsp701A was knock down (P<0.05). CONCLUSION: Knockdown of Hsp701A gene by siRNA enhances sensitivity to chemotherapeutic drug in HepG2 cells.

Animals↗

PubMed1990

Simultaneous assay for megakaryocyte colony-stimulating factor and megakaryocyte potentiator and its application.

We have devised a simultaneous assay system for megakaryocyte colony-stimulating factor (Meg-CSF) and megakaryocyte potentiator (Meg-Pot) by modifying a quantitative measuring technique for acetylcholinesterase activity (Ach-E) of megakaryocytes by automatic colorimetry using microplates. We cultured murine bone marrow cells treated with diisopropyl fluorophosphate in a serum-free system with serum-free pokeweek mitogen-stimulated spleen cell conditioned medium (PWM-SCM) and an unknown factor, preparing two microplates with the identical culture system. In the first plate, the total number of Ach-E-positive cells induced solely by the factor tested was indicative of Meg-CSF activity and additive increases in this parameter on simultaneous addition of PWM-SCM and the factor tested were indicative of early Meg-Pot activity. Total Ach-E activity (total change at optical density of 414 nm) per well was measured in the second plate to calculate total change at optical density of 414 nm per megakaryocyte, an indicator of late Meg-Pot activity. With this system, recombinant human erythropoietin showed both Meg-CSF and early and late Meg-Pot activities in in vitro megakaryopoiesis. Recombinant murine granulocyte-macrophage colony-stimulating factor possessed weak Meg-CSF and early Meg-Pot activity, whereas recombinant human granulocyte colony-stimulating factor exhibited late Meg-Pot activity and thrombocytopenic serum exhibited early and late Meg-Pot activities. This assay system is useful in screening Meg-CSF or Meg-Pot activities in unknown factors.

Acetylcholinesterase↗

PubMed2006

[Effects of Cinnabar and Realgar in Angong Niuhuang powder on heat shock protein, nitric oxide synthase and inflammatory cytokines in contusion cerebral edema].

OBJECTIVE: To explore the pharmacological mechanism of Cinnabar and Realgar in Angong Niuhuang powder (ANP). METHODS: SD rats were randomly divided into six groups (12 rats/group): normal controls group (NS group), contusion cerebral edema model group( CCE group) , cerebral edema rats administrated by cinnabar 0. 15 g/kg 1h (CA group), cerebral edema rats administrated by realgar 0.15 g/kg 1h (RG group), cerebral edema rats administrated by Angong Niuhuang powder 1.5 g/kg 1h (ANP I group), cerebral edema rats administrated by Angong Niuhuang powder substracted cinnabar and realgar 1.2 g/kg 1h (ANP II group). Each group was divided into two subgroups (6 rats/subgroup). The rats in subgroups were killed at 8h and 24h after modeling respectively. Expression of heat shock protein 70 ( HSP 70) mRNA in brain tissues was measured by RT-PCR. Activities of nitric oxide synthase (NOS) and its isoenzymes (iNOS, cNOS) in brain tissues were tested by colorimetry. Levels of tumor necrosis factor-alpha (TNF-alpha) and interleukin-1 beta (IL-1beta) in serum were determined by radioimmunoassay (RIA). RESULTS: Expression of HSP 70 mRNA in ANP I group and ANP II group significantly increased as compared with CCE group 8h after being modeled (P < 0.05), and increase range in ANP I group were singificantly higher than that in ANP II group (P < 0.05). Activities of iNOS in CA group, RG group, ANP I group and ANP II group were lower than that in CCE group 8h after being modeled (P < 0.05) , and the activities in ANP I group were the lowest in the four groups. Levels of TNF-alpha in RG group, ANP I group and ANP II group decreased obviously as compared with CCE group 8h after being modeled (P < 0.05) , so did levels of IL-1beta in ANP I group and ANP II group (P < 0.05). But no significant difference was shown between ANP I group and ANP 11 group. CONCLUSION: HSP 70, iNOS, TNF-alpha and IL-1beta are involved in contusion cerebral edema. ANP and CA, RG in ANP are protective against CCE in rats. It may be associated with the increase of HSP 70 mRNA expression, inhibition of iNOS activity, and the decreasae of inflammatory cytokines (TNF-alpha, IL-1beta) levels.

Animals↗

PubMed2006

Effects of lower fluence pulsed dye laser irradiation on production of collagen and the mRNA expression of collagen relative gene in cultured fibroblasts in vitro.

BACKGROUND: Lower fluence of 585-nm flashlamp-pumped pulsed dye laser has been successfully used as a nonablative technique in the treatment of wrinkles. The objective of this study was to evaluate the effect of the pulsed dye laser (585 nm) on the production of collagen and the mRNA expression of collagen related gene in fibroblasts in vitro. METHODS: Cultured fibroblasts were treated with a 585-nm flashlamp-pumped pulsed dye laser (fluence 3 J/cm(2), 4 J/cm(2), spot size 7 mm, pulse duration 450 micros). The production of collagen and the mRNA expression of transforming growth factor (TGF)-beta1, SMAD2, SMAD3, SMAD4, SMAD7 and type I procollagen alpha1, alpha2 in fibroblasts were investigated by colorimetry or real time polymerase chain reaction. RESULTS: The production of collagen was significantly up-regulated after treatment with a 585-nm flashlamp-pumped pulsed dye laser with a fluence of 3 J/cm(2) (P < 0.001). The mRNA expression of TGF-beta1, SMAD2, SMAD3, SMAD4, SMAD7 and procollagen I was significantly up-regulated after treatment with a 585-nm flashlamp-pumped pulsed dye laser with a fluence of 3 J/cm(2) (P < 0.001). No significant difference of mRNA expression of SMAD2, SMAD3, SMAD4, SMAD7 and type I procollagen was found between controls and fibroblasts treated with pulsed dye laser with a fluence of 4 J/cm(2) (P > 0.05). CONCLUSIONS: Lower fluence (3 J/cm(2)) pulsed dye laser increased the collagen production in fibroblasts by up-regulating TGF-beta1, SMAD2, SMAD3, SMAD4, SMAD7 and type I procollagen mRNA expression. These may be the reason it can be effectively used in the treatment of wrinkles.

Analysis of Variance↗

PubMed2006

[The study on angiogenesis activity of danggui, chuanxiong and danshen].

OBJECTIVE: To observe the effect of danggui (Radix angelicae sinensis), chuanxiong (Rhizoma chuanxiong) and danshen (Radix salvae miltionrrhizae) on cardiac microvascular endothelial cells (CMECs) obtained from rat and quantitation of vessels on chick embryo chorioallantoic membrane (CAM) model. METHODS: Normal rat cardiac microvascular endothelial cells (CMECs) were cultured by collagenase and trypsin and the influences of the herbs on the CMECs were observed by cell count and MTT colorimetry. The activity of blood vessels was determined by quantitation of vessels on chick embryo chorioallantoic membrane (CAM) model. RESULTS: Compared with the normal group, after treatment with chuanxiong of high dosage, danggui of high and middle dosages, danshen of high and middle and low dosages, they enhanced proliferation significantly (P < 0.05). The two later could be in dependent dose. And the herbs might increase quantitation of vessels on CAM. CONCLUSION: These Chinese herbs may promote angiogenesis by stimulating proliferation of CMEC and incresasing blood vessels.

Allantois↗

PubMed2006

[Correlation studies of contents of copper and organic components in Astragalus roots].

OBJECTIVE: To study the relationship between copper and organic components, total flavonoids of Astragalus (TFA), total saponins of Astragalus (TSA) and total polysaccharide of Astragalus (TPA). METHOD: TFA, TSA and TPA were extracted from Astragalus roots using different organic solvents, and determined by colorimetry. The concentration of copper in extracts was determined by graphite furnace atomic absorption spectrometry (GFAAS). RESULT: Copper was found in TFA, TPA and TSA, and its concentration in TFA and TPA was higher; the content of copper was correlated significantly to that of TFA and TPA (r1(2) = 0.754 8, F1 = 57.202, P < 0.01 and r2(2) = 0.499, F2 = 21.906, P < 0.01), while not to that of TSA ( r3(2) = 0.0026, F3 = 0.041, P > 0.1). CONCLUSION: Correlation analysis could reveal the relationship of copper with organic components in Astragalus roots; contents and structure characteristics of organic components might be important factors influencing the distribution of copper in Astragalus roots.

Astragalus propinquus↗

PubMed2006

[Soil carbohydrates: their determination methods and indication functions].

Soil carbohydrates are the important component of soil organic matter, and play an important role in soil aggregation formation. Their hydrolysis methods involve sulfur acid (H2SO4), hydrochloric acid (HCl), and trifluoroacetic acid (TFA) hydrolysis, and their determination methods include colorimetry, gas-liquid chromatography (GLC) , high performance liquid chromatography (HPLC), and high performance anion-exchange chromatography with pulsed amperometric detection (HPAE-PAD). This paper summarized the methods of carbohydrates' hydrolysis, purification and detection, with focus on the derived methods of GLC, and briefly introduced the indication functions of carbohydrates in soil organic matter turnover.

Carbohydrates↗

PubMed2006

[Mutations of tumor suppressor gene PTEN mutations in hepatocellular carcinoma and its implications in tumor proliferation and apoptosis].

OBJECTIVE: To study mutations of tumor suppressor gene PTEN in human hepatocellular carcinomas and its effects on the proliferation and apoptosis of hepatocellular carcinoma cell line HHCC. METHODS: (1) PCR-SSCP and sequence analysis were used to detect the mutations of the 5th and 8th exon of PTEN in 42 cases of human primary hepatocellular carcinoma. (2) Eukaryotic expression vectors of the wild-type (pEGFP-wt-PTEN) and the mutant type (pEGFP-PTEN, G129R) of PTEN were constructed. Lipofectamine 2000 mediated gene transfection was used to transfect hepatocellular carcinoma cell line HHCC, in which the PTEN protein is not expressed. Culture medium containing G418 was used to select stable transfectants. MTT colorimetry was used to analyze the proliferation ability of selected cell lines. Naive HHCC cells and HHCC cells transfected with empty vector (pEGFP-C1) served as controls. (3) TNF-alpha was used to induce apoptosis of selected cell clones. RESULTS: (1) Point mutation involving the 5th exon of PTEN was detected in 4 of 42 primary hepatocellular carcinomas. (2) Compared with the control groups, the proliferation of hepatocellular carcinoma cells was significantly inhibited by the transfection of wild-type PTEN gene, while the transfection with mutant PTEN construct did not significantly change the proliferation. (3) The apoptosis indices of cells transfected with the wild-type and the mutant PTEN genes were 13.8% and 8.1% respectively. Compared with the control, the apoptosis index of HHCC cell transfected by the wild type PTEN was significantly lower (P < 0.05). There were no significant differences between HHCC cells transfected with mutated PTEN gene and the control (P > 0.05). The expression of internal 473-phosphorylated Akt of HHCC was weak, but was enhanced when the cells treated with TNF-alpha. However, it was down regulated by the wild type PTEN. CONCLUSIONS: (1) First time report that PTEN mutations can be found in 9.5% human primary hepatocellular carcinomas. (2) The expression of the wild-type PTEN can suppress the proliferation of HHCC cells, and such suppression was lost when PTEN gene was mutated. (3) PTEN inhibition of the proliferation and the enhancement of apoptosis of hepatocellular carcinoma cells is likely related to a down-regulation of the TNF-alpha induced activation of protein kinase Akt pathway.

Apoptosis↗