Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.4.2.7 (adenine phosphoribosyltransferase)
 692 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

DtxR is a dimeric, sequence-specific, DNA-binding protein that functions as an iron-dependent, negative global regulator in Corynebacterium diphtheriae. Under high-iron conditions, DtxR represses the synthesis of diphtheria toxin, corynebacterial siderophore, and other components of the high-affinity iron uptake system. Three DtxR-regulated promoter/operators designated tox, IRP1, and IRP2 were reported previously. In this study, we identified and characterized three additional DtxR-regulated promoter/operators from C. diphtheriae designated IRP3, IRP4, and IRP5. When beta-galactosidase was expressed from these three new promoter/ operators in Escherichia coli containing dtxR+ on pDSK29, enzyme levels were 5- to 30-fold lower during high-iron growth than during low-iron growth. In gel shift assays, the mobility of DNA fragments containing each promoter/operator decreased in the presence of purified DtxR and Co2+. In footprinting assays, DtxR protected 36-, 35-, and 30-bp regions of IRP3, IRP4, and IRP5, respectively, from cleavage by DNase I. In the 19-bp core of each promoter/operator, 12 or 13 bp matched the consensus for the DtxR-binding site. The putative polypeptides encoded by the open reading frames (ORFs) downstream from IRP3 and IRP4 were homologous, respectively, to several bacterial transcriptional regulators and to the deduced polypeptide encoded by an ORF located between the E. coli genes for primosomal replication protein N and adenine phosphoribosyltransferase. The putative polypeptide encoded by the ORF downstream from IRP5 was not homologous to any sequence in the protein database at the National Center for Biotechnology Information. When the ORFs downstream from IRP3 and IRP4 were expressed under the control of the phage T7 promoter in E. coli, polypeptide products of the predicted sizes were detected in small amounts by sodium dodecyl sulfate-polyacrylamide gel electrophoresis.
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PMID:Identification and characterization of three new promoter/operators from Corynebacterium diphtheriae that are regulated by the diphtheria toxin repressor (DtxR) and iron. 931 37

To review the outcome of successive surgery, chemotherapy and abdomino-pelvic radiotherapy in ovarian cancer; 212 patients who had been treated with surgery, chemotherapy, and APRT, during 10 years were studied. The patients ranged in age from 23 to 76 years (median 53). International Federation of Gynecology and Obstetrics staging showed 32 patients in stage Ic, 57 in stage II and 123 in stage III. Serous carcinoma was the most frequent type. Most of the patients had grade 1 histology. The majority had undergone optimal cytoreductive surgery. They were put on platinum-based chemotherapy and got APRT. Chemotherapy was started before, after or three courses before and three after radiation. Radiotherapy was delivered using Cobalt-60 anterior posterior fields to encompass the peritoneal cavity. They received at least 2000 cGy to abdomen and 5000 cGy to the pelvis. Minimum follow-up was 60 months. The result showed that most of the patients experienced RTOG grade 1 or 2 acute toxicities that responded to medication. Late complications were reasonable (3.8%), mostly were managed conservatively. Unplanned radiation interruptions were necessary in 42 patients (20%). Stage, grade and histology affected survival. Failure sites were abdomen in 35 cases, pelvis in 34, both pelvis and abdomen in 19 and distant metastasis in 34 cases. Overall, five-ear survival was 84.4%, 65%, 21% in stages Ic, II, III, respectively. We came to the conclusion that: Abdomino-pelvic radiotherapy is a safe adjuvant treatment in ovarian cancer and is well tolerated by most patients. Abdomino-pelvic radiotherapy does not significantly increase treatment complications in ovarian cancer. Radiation should be concerned in patients with high probability of recurrence of epithelial ovarian tumours.
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PMID:Results of post-operative abdomino-pelvic radiotherapy in intermediate- and high-risk epithelial ovarian carcinoma. 1853 15