Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.7.1.2 (nitrate reductase)
 3,861 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Carcinoma of the urinary bladder is the most common malignancy in Egyptians. At the National Cancer Institute in Cairo, it accounts for 27.6% of all cancers--38.5% of cancers in the male and 11.3% in the female. This very high frequency is attributed to underlying schistosomiasis. The infection can lead to malignancy through local tissue damage, mechanical irritation, bilharzial toxins or through secondary bacterial infection. Bacterial products include nitrate reductase capable of synthesizing nitrosoamines and beta glucuronidase enzymes, active at pH 7. Through liver involvement and dysfunction, tryptophan metabolism is disturbed, with the excretion of carcinogenic metabolites. Vitamin A deficiency is responsible for the squamous metaplasia and the high frequency of squamous cell carcinoma observed in the bladder. The characteristic clinico-pathological features of cancer of the urinary bladder are outlined, mainly the occurrence at a young age, the male predominance, especially farmers, and the high association with schistosomiasis. The tumors are often first seen in an advanced stage, arising from the posterior bladder wall and vault. The trigone is only affected in 8.5% of the cases. Histologically, squamous cell carcinomas of low grade are the most frequent cell type. Lymph node involvement is low in spite of the advanced stage of the tumor. Therefore, the results of radical surgery are encouraging. The results of a special study correlating the above parameters with the intensity of ova deposition are presented. Patients with heavy infection at a slightly earlier age but other tumor parameters the same are similar to those of egg-negative cases. This study indicates that other factors also play a role in the induction of tumors that are enhanced by the schistosomal infection. In Fayoum Province, schistosomiasis is decreasing while bladder cancer is increasing. Urine cytology as a screening tool is effective in detecting early bladder cancer. Studies are now in progress to detect tumor associated antigens in sera and urine of patients.
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PMID:Carcinoma of the urinary bladder associated with schistosomiasis in Egypt: the possible causal relationship. 314 81

A correlation was obtained between a positive nitrite test in urine and the severity of urinary bacterial infection. Bacteria isolated from the urine of bilharzial or bladder cancer patients were found to be rich in nitrate reductase activity. "Escherichia coli" was the most common microorganism isolated from these specimens. Urine and several urinary constituents activate bacterial nitrate reductase. beta-Glucuronidase activity in the urine of patients with chronic "Schistosoma haematobium" infection and bladder cancer was measured and shown to be significantly greater than that of urine of normal control subjects. Urinary bacterial infection was shown to be the source of the increased urinary level of enzyme activity at pH 7.0.
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PMID:A study on the etiological factors of bilharzial bladder cancer in Egypt. 6. The possible role of urinary bacteria. 704 78

From two different specimens of a chronic prosthetic hip infection taken at an interval of 2 months a slow-growing gram-negative bacterium was isolated in pure culture. The strain grew with the typical features of a small-colony variant (SCV). 16S rRNA sequencing identified the bacterium as Escherichia coli. Biochemical characterization demonstrated multiple phenotypic alterations of a mutant carrying a defect in the heme biosynthetic pathway (Hem-): (i) catalase and nitrate reductase reactions were both negative, (ii) a negative benzidine reaction demonstrated the lack of heme-containing cytochromes, and (iii) growth stimulation under anaerobic conditions as well as gentamicin resistance indicated defective aerobic respiration. PCR and Southern hybridization demonstrated that the mutation of the SCV of E. coli was localized in the hemB gene and was most likely due to a deletion of the hemB gene. On blood agar plates revertants were recognized growing as normal-sized colonies between the dominant small colonies of the strain. Feeding experiments indicated that the revertants but not the small colonies were permeable for hemin. A strong antibody response against the infecting SCV of E. coli was found. To our knowledge, this is the first report of a Hem- E. coli strain as the etiological agent of a chronic bacterial infection.
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PMID:Chronic prosthetic hip infection caused by a small-colony variant of Escherichia coli. 970 87

Nitrate reductase (NR) has emerged as a potential NO source in plants. Indeed, the Arabidopsis thaliana NR double-deficient mutant (nia1 nia2) produces low NO and develops abnormal susceptibility to bacterial infection. We have employed quantitative real-time polymerase chain reactions to analyze the effects of NO gas on the expression of defense-related genes in wild-type and nia1 nia2 A. thaliana plants that were inoculated with an avirulent strain of Pseudomonas syringae pv. tomato. The pathogenesis-related gene 1 (PR1) was up-regulated by bacterial infection, and its expression was higher in the wild type than in nia1 nia2. Fumigation with NO attenuated the expression of PR1 and other salicylic acid-related genes in plants that had been inoculated with P. syringae. Nevertheless, NO inhibited the most intense bacterial growth and disease symptoms in nia1 nia2 leaves. The NO fumigation also directly modulated lignin biosynthesis-related gene expression (CAD1) and parts of the auxin (TIR1, ILL1, GH3) and ethylene (ACCS7) pathways, among other defense-related genes, and their modulation was more intense in the NR-deficient mutant. Pathogen inoculation induced delayed but intense H2O2 production in mutant leaves in comparison with the wild type. Hydrogen peroxide potentiated the microbicidal effects of NO against bacterial cultures. These results suggest that NO has a direct microbicidal effect in combination with H2O2 to allow for the attenuation of the SA-mediated defense response, thereby reducing the energy expenditure associated with defense-related gene transcription. Overall, these results highlight the importance of NR-dependent NO production in the establishment of disease resistance.
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PMID:Nitrate reductase is required for the transcriptional modulation and bactericidal activity of nitric oxide during the defense response of Arabidopsis thaliana against Pseudomonas syringae. 2374 75