The distribution of ^(125)I recombinant E. coli L-asparaginase in tissues ororgans and the excretion in urine, feces and bile were studied with in vivo radioactive tracertechnique. The amount of radioactivity excreted...The distribution of ^(125)I recombinant E. coli L-asparaginase in tissues ororgans and the excretion in urine, feces and bile were studied with in vivo radioactive tracertechnique. The amount of radioactivity excreted in urine, feces and bile within 24 h afterintravenous administration of ^(125)I recombinant E. col L-asparaginase to rats was 68.95% ,4.44%and 5.36% of the dose respectively. ^(125)I recombinant E. coli L-asparaginase in plasma samples wasdetermined. The levels of structural intact molecule in plasma samples were evaluated by SDS-PAGEand bio-imaging analyzer system. Pharmacokinetic parameters were assessed with a model-dependentmethod. The concentration-time curves of recombinant E. coli L-asparaginase after intravenousinjection at 1 250 IU·kg^(-1), 2 500, IU·kg^(-1), 5 000 IU·kg^(-1) to rats were consistent withthe two-compartment model. The first and terminal elimination t_(1/2) were 0.52 ~ 0.63 h and 2.39 ~2.76 h respectively. AUC was linearly related to the doses. The results of distribution in tissuesor organs and excretion in urine suggested that the metabolites of the enzyme were cleared bymechanisms of urinary excretion. Pharmacokinetics parameters of recombinant E. coli L- asparaginasein rats are warranted for the design of future clinical trials.展开更多
AIM： To analyse the role of two common polymorphisms in genes coding for histamine metabolising enzymes as it relates to the risk to develop ulcerative colitis （UC） and the clinical course of these patients. METHOD...AIM： To analyse the role of two common polymorphisms in genes coding for histamine metabolising enzymes as it relates to the risk to develop ulcerative colitis （UC） and the clinical course of these patients. METHODS： A cohort of 229 unrelated patients with UC recruited from a single centre and 261 healthy volunteers were analysed for the presence of Thr105Ile and His645Asp amino acid substitutions at histamine N-methyltransferase （HNMT） and diamine oxidase （ABP1） enzymes, respectively, by amplification-restriction procedures. All patients were phenotyped and followed up for at least 2 years （mean time 11 years）. RESULTS： There were no significant differences in the distribution of ABP1 alleles between ulcerative colitis patients and healthy individuals [OR （95% CI） for variant alleles = 1.22 （0.91-1.61）]. However, mutated ABP1 alleles were present with higher frequency among the 58 patients that required immunosuppresive drugs [OR （95 % CI） for carriers of mutated alleles 2.41 （1.21-4.83; P=0.006）], with a significant gene-dose effect （P= 0.0038）. In agreement with the predominant role of ABP1 versus HNMT on local histamine metabolism in human bowel, the frequencies for carriers of HNMT genotypes or mutated alleles were similar among patients,regardless clinical evolution, and control individuals. CONCLUSION： The His645Asp polymorphism of the histamine metabolising enzyme ABP1 is related to severity of ulcerative colitis.展开更多
LSD1 （KDM1 under the new nomenclature） was the first identified lysine-specific histone demethylase belonging to the flavin-dependent amine oxidase family. Here, we report that AOF1 （KDM1B under the new nomenclatur...LSD1 （KDM1 under the new nomenclature） was the first identified lysine-specific histone demethylase belonging to the flavin-dependent amine oxidase family. Here, we report that AOF1 （KDM1B under the new nomenclature）, a mammalian protein related to LSD1, also possesses histone demethylase activity with specificity for H3K4mel and H3K4me2. Like LSD1, the highly conserved SWIRM domain is required for its enzymatic activity. However, AOF1 differs from LSD1 in several aspects. First, AOF1 does not appear to form stable protein complexes containing histone deacetylases. Second, AOF1 is found to localize to chromosomes during the mitotic phase of the cell cycle, whereas LSD1 does not. Third, AOF1 represses transcription when tethered to DNA and this repression activity is independent of its demethylase activity. Structural and functional analyses identified its unique N-terminal Zf-CW domain as essential for the demethylase activity-independent repression function. Collectively, our study identifies AOF1 as the second histone demethylase in the family of flavin-dependent amine oxidases and reveals a demethylase-independent repression function of AOF1.展开更多
AIM:To investigate whether a tissue-transglutaminase antibody(tTGA) level ≥ 100 U/mL is sufficient for the diagnosis of celiac disease(CD).METHODS:Children suspected of having CD were prospectively included in our st...AIM:To investigate whether a tissue-transglutaminase antibody(tTGA) level ≥ 100 U/mL is sufficient for the diagnosis of celiac disease(CD).METHODS:Children suspected of having CD were prospectively included in our study between March 2009 and September 2011.All patients with immune globulin A deficiency and all patients on a gluten-free diet were excluded from the study.Anti-endomysium antibodies(EMA) were detected by means of immunofluorescence using sections of distal monkey esophagus(EUROIMMUN,Luebeck,Germany).Serum anti-tTGA were measured by means of enzyme-linked immunosorbent assay using human recombinant tissue transglutaminase(ELiA Celikey IgA kit Phadia AB,Uppsala,Sweden).The histological slides were graded by a single experienced pathologist using the Marsh classification as modified by Oberhuber.Marsh Ⅱ and Ⅲ lesions were considered to be diagnostic for the disease.The positive predictive values(PPVs),negative predictive values(NPVs),sensitivity and specificity of EMA and tTGA along with their 95% CI(for the cut off values > 10 and ≥ 100 U/mL) were calculated using histology as the gold standard for CD.RESULTS:A total of 183 children were included in the study.A total of 70(38.3%) were male,while 113(61.7%) were female.The age range was between 1.0 and 17.6 years,and the mean age was 6.2 years.One hundred twenty(65.6%) patients had a small intestinal biopsy diagnostic for the disease;3 patients had a Marsh Ⅱ lesion,and 117 patients had a Marsh Ⅲ lesion.Of the patients without CD,only 4 patients had a MarshⅠlesion.Of the 183 patients,136 patients were positive for EMA,of whom 20 did not have CD,yielding a PPV for EMA of 85%(95% CI:78%-90%) and a corresponding specificity of 68%(95% CI:55%-79%).The NPV and specificity for EMA were 91%(95% CI:79%-97%) and 97%(95% CI:91%-99%),respectively.Increased levels of tTGA were found in 130 patients,although only 116 patients truly had histological evidence of the disease.The PPV for tTGA was 89%(95% CI:82%-94%),and the corresponding specificity was 78%(95% CI:65%-87%).The NPV and sensitivity were 92%(95% CI:81%-98%) and 97%(95% CI:91%-99%),respectively.A tTGA level ≥ 100 U/mL was found in 87(47.5%) patients,all of whom were also positive for EMA.In all these 87 patients,epithelial lesions confirming CD were found,giving a PPV of 100%(95%CI:95%-100%).The corresponding specificity for this cutoff value was also 100%(95% CI:93%-100%).Within this group,a total of 83 patients had symptoms,at least gastrointestinal and/or growth retardation.Three patients were asymptomatic but were screened because they belonged to a group at risk for CD(diabetes mellitus type 1 or positive family history).The fourth patient who lacked CD-symptoms was detected by coincidence during an endoscopy performed for gastro-intestinal bleeding.CONCLUSION:This study confirms based on prospective data that a small intestinal biopsy is not necessary for the diagnosis of CD in symptomatic patients with tTGA ≥ 100 U/mL.展开更多
Objective. To study the characteristics of changes of LDH enzyme patterns of mice under slight hypoxia.Methods. Mice treated with artificial hypoxia, various tissues were made for the test of LDH enzymatic activity by...Objective. To study the characteristics of changes of LDH enzyme patterns of mice under slight hypoxia.Methods. Mice treated with artificial hypoxia, various tissues were made for the test of LDH enzymatic activity by the specific staining technique. LDH (1 -5) relative percentage enzymatic activity (RPEA) were measured with CS-910 dual-wavelength thin layer chromatography scanner.Results. The RPEA of LDH isozymes of various tissues after slight hypoxia shifted to the isozymes LDH1 and LDH2, whose principal subunits are H subunits, and the RPEA of LDH,(H4), LDH2(H3M) increased, while RPEA of LDH5(M4) in various tissues decreased prominently except the cardiac muscle, and that of LDH4(HM3) decreased as well. After polyacrylamide gel electrophoresis (PAGE) of the hypoxia treated cardiac muscle specimen was made, activity subbands originated regularly in the isozyme patterns of LDH, with the regularity of LDH1 (0 subband), LDH2 (0-1 subbands), LDH3 (0-2 subbands), LDH4 (1-3 subbands), LDH5 (2-4 subbands). After adding appropriate amount of NAD+ to the hypoxia treated cardiac muscle specimen, PAGE showed the subbands of four isozymes (LDH2-LDH5) reduced or even totally disappeared in the isozyme patterns.Conclusions. The negative feedback regulation of coenzymization and decoenzymization of LDH isozymes is one of the mouse stress responses to slight hypoxia.展开更多
基金ProjectsupportedbytheNationalNinth FivePlanKeyProjectFoundation No 96 90 2 0 1 2 5
文摘The distribution of ^(125)I recombinant E. coli L-asparaginase in tissues ororgans and the excretion in urine, feces and bile were studied with in vivo radioactive tracertechnique. The amount of radioactivity excreted in urine, feces and bile within 24 h afterintravenous administration of ^(125)I recombinant E. col L-asparaginase to rats was 68.95% ,4.44%and 5.36% of the dose respectively. ^(125)I recombinant E. coli L-asparaginase in plasma samples wasdetermined. The levels of structural intact molecule in plasma samples were evaluated by SDS-PAGEand bio-imaging analyzer system. Pharmacokinetic parameters were assessed with a model-dependentmethod. The concentration-time curves of recombinant E. coli L-asparaginase after intravenousinjection at 1 250 IU·kg^(-1), 2 500, IU·kg^(-1), 5 000 IU·kg^(-1) to rats were consistent withthe two-compartment model. The first and terminal elimination t_(1/2) were 0.52 ~ 0.63 h and 2.39 ~2.76 h respectively. AUC was linearly related to the doses. The results of distribution in tissuesor organs and excretion in urine suggested that the metabolites of the enzyme were cleared bymechanisms of urinary excretion. Pharmacokinetics parameters of recombinant E. coli L- asparaginasein rats are warranted for the design of future clinical trials.
基金Supported by Grants SAF 2003-00967 from Ministerio de Ciencia y Tecnología and FIS 02/0255 from Fondo de Investigación Sanitaria,Instituto de Salud Carlos Ⅲ,Madrid,Spain
文摘AIM： To analyse the role of two common polymorphisms in genes coding for histamine metabolising enzymes as it relates to the risk to develop ulcerative colitis （UC） and the clinical course of these patients. METHODS： A cohort of 229 unrelated patients with UC recruited from a single centre and 261 healthy volunteers were analysed for the presence of Thr105Ile and His645Asp amino acid substitutions at histamine N-methyltransferase （HNMT） and diamine oxidase （ABP1） enzymes, respectively, by amplification-restriction procedures. All patients were phenotyped and followed up for at least 2 years （mean time 11 years）. RESULTS： There were no significant differences in the distribution of ABP1 alleles between ulcerative colitis patients and healthy individuals [OR （95% CI） for variant alleles = 1.22 （0.91-1.61）]. However, mutated ABP1 alleles were present with higher frequency among the 58 patients that required immunosuppresive drugs [OR （95 % CI） for carriers of mutated alleles 2.41 （1.21-4.83; P=0.006）], with a significant gene-dose effect （P= 0.0038）. In agreement with the predominant role of ABP1 versus HNMT on local histamine metabolism in human bowel, the frequencies for carriers of HNMT genotypes or mutated alleles were similar among patients,regardless clinical evolution, and control individuals. CONCLUSION： The His645Asp polymorphism of the histamine metabolising enzyme ABP1 is related to severity of ulcerative colitis.
基金We thank Dr Ramin Shiekhattar （Wistar Institute, USA） for the baculoviruses expressing Flag-LSD1 and Drs Jianguo Song and Degui Chen （Shanghai Institute of Biochemistry and Cell Biol- ogy, China） for anti-HDAC1 antibody and H3K36me2 antibody, respectively. This study was partially supported by grants from the National Natural Science Foundation of China （90919025, 30871381）, the Ministry of Science and Technology of China （2009CB918402, 2009CB825601） and the Research Platform for Cell Signaling Networks from the Science and Technology Com- mission of Shanghai Municipality （06DZ22923）.
文摘LSD1 （KDM1 under the new nomenclature） was the first identified lysine-specific histone demethylase belonging to the flavin-dependent amine oxidase family. Here, we report that AOF1 （KDM1B under the new nomenclature）, a mammalian protein related to LSD1, also possesses histone demethylase activity with specificity for H3K4mel and H3K4me2. Like LSD1, the highly conserved SWIRM domain is required for its enzymatic activity. However, AOF1 differs from LSD1 in several aspects. First, AOF1 does not appear to form stable protein complexes containing histone deacetylases. Second, AOF1 is found to localize to chromosomes during the mitotic phase of the cell cycle, whereas LSD1 does not. Third, AOF1 represses transcription when tethered to DNA and this repression activity is independent of its demethylase activity. Structural and functional analyses identified its unique N-terminal Zf-CW domain as essential for the demethylase activity-independent repression function. Collectively, our study identifies AOF1 as the second histone demethylase in the family of flavin-dependent amine oxidases and reveals a demethylase-independent repression function of AOF1.
文摘AIM:To investigate whether a tissue-transglutaminase antibody(tTGA) level ≥ 100 U/mL is sufficient for the diagnosis of celiac disease(CD).METHODS:Children suspected of having CD were prospectively included in our study between March 2009 and September 2011.All patients with immune globulin A deficiency and all patients on a gluten-free diet were excluded from the study.Anti-endomysium antibodies(EMA) were detected by means of immunofluorescence using sections of distal monkey esophagus(EUROIMMUN,Luebeck,Germany).Serum anti-tTGA were measured by means of enzyme-linked immunosorbent assay using human recombinant tissue transglutaminase(ELiA Celikey IgA kit Phadia AB,Uppsala,Sweden).The histological slides were graded by a single experienced pathologist using the Marsh classification as modified by Oberhuber.Marsh Ⅱ and Ⅲ lesions were considered to be diagnostic for the disease.The positive predictive values(PPVs),negative predictive values(NPVs),sensitivity and specificity of EMA and tTGA along with their 95% CI(for the cut off values > 10 and ≥ 100 U/mL) were calculated using histology as the gold standard for CD.RESULTS:A total of 183 children were included in the study.A total of 70(38.3%) were male,while 113(61.7%) were female.The age range was between 1.0 and 17.6 years,and the mean age was 6.2 years.One hundred twenty(65.6%) patients had a small intestinal biopsy diagnostic for the disease;3 patients had a Marsh Ⅱ lesion,and 117 patients had a Marsh Ⅲ lesion.Of the patients without CD,only 4 patients had a MarshⅠlesion.Of the 183 patients,136 patients were positive for EMA,of whom 20 did not have CD,yielding a PPV for EMA of 85%(95% CI:78%-90%) and a corresponding specificity of 68%(95% CI:55%-79%).The NPV and specificity for EMA were 91%(95% CI:79%-97%) and 97%(95% CI:91%-99%),respectively.Increased levels of tTGA were found in 130 patients,although only 116 patients truly had histological evidence of the disease.The PPV for tTGA was 89%(95% CI:82%-94%),and the corresponding specificity was 78%(95% CI:65%-87%).The NPV and sensitivity were 92%(95% CI:81%-98%) and 97%(95% CI:91%-99%),respectively.A tTGA level ≥ 100 U/mL was found in 87(47.5%) patients,all of whom were also positive for EMA.In all these 87 patients,epithelial lesions confirming CD were found,giving a PPV of 100%(95%CI:95%-100%).The corresponding specificity for this cutoff value was also 100%(95% CI:93%-100%).Within this group,a total of 83 patients had symptoms,at least gastrointestinal and/or growth retardation.Three patients were asymptomatic but were screened because they belonged to a group at risk for CD(diabetes mellitus type 1 or positive family history).The fourth patient who lacked CD-symptoms was detected by coincidence during an endoscopy performed for gastro-intestinal bleeding.CONCLUSION:This study confirms based on prospective data that a small intestinal biopsy is not necessary for the diagnosis of CD in symptomatic patients with tTGA ≥ 100 U/mL.
文摘Objective. To study the characteristics of changes of LDH enzyme patterns of mice under slight hypoxia.Methods. Mice treated with artificial hypoxia, various tissues were made for the test of LDH enzymatic activity by the specific staining technique. LDH (1 -5) relative percentage enzymatic activity (RPEA) were measured with CS-910 dual-wavelength thin layer chromatography scanner.Results. The RPEA of LDH isozymes of various tissues after slight hypoxia shifted to the isozymes LDH1 and LDH2, whose principal subunits are H subunits, and the RPEA of LDH,(H4), LDH2(H3M) increased, while RPEA of LDH5(M4) in various tissues decreased prominently except the cardiac muscle, and that of LDH4(HM3) decreased as well. After polyacrylamide gel electrophoresis (PAGE) of the hypoxia treated cardiac muscle specimen was made, activity subbands originated regularly in the isozyme patterns of LDH, with the regularity of LDH1 (0 subband), LDH2 (0-1 subbands), LDH3 (0-2 subbands), LDH4 (1-3 subbands), LDH5 (2-4 subbands). After adding appropriate amount of NAD+ to the hypoxia treated cardiac muscle specimen, PAGE showed the subbands of four isozymes (LDH2-LDH5) reduced or even totally disappeared in the isozyme patterns.Conclusions. The negative feedback regulation of coenzymization and decoenzymization of LDH isozymes is one of the mouse stress responses to slight hypoxia.
