Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.5.1.1 (asparaginase)
 2,695 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Lymphoblasts from 21 previously untreated patients with acute lymphoblastic leukemia (ALL) and 31 patients in relapse were tested for chemosensitivity. Blast cells were cultured with 22 anticancer drugs for 4 days and assayed by MTT dye using a scanning microplate photometer. The percent cytotoxicity index (%CI) and LD50 (micrograms/ml) were calculated for each drug. The mean absorbances (+/- S.D.) of 1 x 10(5) cells in the untreated group and relapsed groups in control wells were 0.219 (+/- 0.126) and 0.385 (+/- 0.147), respectively (p less than 0.01). Cells in the untreated group were more sensitive in vitro to vincristine, prednisolone, L-asparaginase (L-ASP), vinblastine, 5-fluorouracil, epirubicin, bleomycin (BLM), and etoposide (VP16) with respect to the %CI value and to L-ASP, VP16, BLM, and mitoxantrone with respect to the LD50 value than those in the relapsed groups. In contrast, no significant differences were observed for the other 13 drugs. There was also a significant difference in sensitivity within the relapsed group--13 having good clinical response and 15 showing no response to chemotherapy--with regard to four drugs, mitomycin C, neocarzinostatin, L-ASP, and teniposide. Cells in the relapsed group had more heterogeneous chemosensitivity than those in the untreated group, and divided into sensitive and resistant types, but large interindividual differences existed. The MTT assay and LD50-drug resistance percentile curves are useful for the selection of effective drugs in both untreated and relapsed patients with acute leukemia.
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PMID:In vitro chemosensitivity of lymphoblasts at relapse in childhood leukemia using the MTT assay. 174 57

A 20-year-old man was admitted to our hospital because of fever and knee joint pain on March 20, 1986. Physical examination revealed generalized lymphadenopathy and hepatomegaly. White blood cell count was 32,800 microliters with 74.4% blast cells. Bone marrow was hypercellular with 93.6% blast cells. Blast cells were weakly positive for acid phosphatase and PAS stainings but were negative for peroxidase, sudan black B and esterase stainings. Cell surface marker analysis of blast cells disclosed that they were positive for anti-HLA-DR, CD19, CD24, CD33 and CD38, but were negative for CD10 and CD20. Cytoplasmic immunoglobulin of blast cells was negative and TdT activity by immunofluorescent method was positive. Chromosomal analysis of bone marrow samples revealed normal karyotype. Therefore, this case was diagnosed as having acute lymphoblastic leukemia (L2) and achieved complete remission with LVP therapy consisting of 1-asparaginase, vincristine and prednisolone. Gene analysis of blast cells disclosed germ-line configuration of both the immunoglobulin heavy chain gene and T cell receptor beta chain gene. We speculated that the phenotype of leukemic cells might precede the genotype in some cases of acute leukemia.
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PMID:[Germ-line configuration of the immunoglobulin heavy chain gene in a case of B cell precursor acute lymphoblastic leukemia]. 255 12

Many novel therapeutic agents are proteins and peptides which need stabilisation due to their inherent instability in aqueous solution. Freeze-drying is an established method for protein stabilisation, although the use of additives is often necessary in order to preserve protein structure and activity during lyophilisation itself. The molecular interactions between protein and protective additive are as yet unclear. In this study, we examined the use of a range of saccharide additives to stabilise the model multi-subunit enzyme L-asparaginase during lyophilisation, assessed post-drying enzyme activity and quaternary structure, and related the extrapolated levels of additive necessary to provide full stabilisation to the theoretical levels predicted from an existing hypothesis using molecular modelling. It was found that each of the saccharides tested here displayed similar levels of protection towards L-asparaginase under the conditions used. Amounts of additive required to give full stabilisation to the enzyme were extrapolated from the activity data and were found to be in good agreement with theoretical amounts calculated from molecular modelling studies. Our data suggest that the existing hypothesis may be relevant to the prediction of optimum levels of lyoprotectant for the freeze-drying of proteins. However, further studies would be necessary in order to obtain a full picture of protein-additive interactions at the molecular level.
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PMID:Protection of the enzyme L-asparaginase during lyophilisation--a molecular modelling approach to predict required level of lyoprotectant. 1050 21

Whitefly infestation of cotton crop imparts enormous damage to cotton yield by severely affecting plant health, vigour and transmitting Cotton Leaf Curl Virus (CLCuV). Genetic modification of cotton helps to overcome both the direct whitefly infestation as well as CLCuV based cotton yield losses. We have constitutively overexpressed asparaginase (ZmASN) gene in Gossypium hirsutum to overcome the cotton yield losses imparted by whitefly infestation. We achieved 2.54% transformation efficiency in CIM-482 by Agrobacterium-mediated shoot apex transformation method. The relative qRT-PCR revealed 40-fold higher transcripts of asparaginase in transgenic cotton line vs. non-transgenic cotton lines. Metabolic analysis showed higher contents of aspartic acid and glutamic acid in seeds and phloem sap of the transgenic cotton lines. Phenotypically, the transgenic cotton lines showed vigorous growth and height, greater number of bolls, and yield. Among six representative transgenic cotton lines, line 14 had higher photosynthetic rate, stomatal conductance, smooth fiber surface, increased fiber convolutions (SEM analysis) and 95% whitefly mortality as compared to non-transgenic cotton line. The gene integration analysis by fluorescence in situ hybridization showed single copy gene integration at chromosome number 1. Collectively, asparaginase gene demonstrated potential to control whitefly infestation, post-infestation damages and improve cotton plant health and yield: a pre-requisite for farmer's community.
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PMID:Constitutive expression of Asparaginase in Gossypium hirsutum triggers insecticidal activity against Bemisia tabaci. 3248 33