Mohsen Akhavan Sepahi, Mostafa Sharifian, Ahmad Shajari, Akram Heidary,
Volume 12, Issue 3 (10-2009)
Abstract
Abstract Background: Prevalence of urolithiasis is increasing in children and maybe hematury is only sign. This study was conducted to investigate clinical manifestation and etiology of urolithiasis in children younger than 14 year-old. Materials and Methods: This descriptive and case-series study was carried out on 100 patients referring to Sahamie Pediatric hospital in Qom in 2007-8. Age, sex, family history, clinical manifestation (fever, dysuria and Pain) and laboratory tests (Na, K, Ca, P, urea, Cr, Albumin, Alkaline phosphates of serum ABG, urine sediment, urine culture Na, K, Ca, P, Cr, oxalate and citrate of urine/24h and cysteine in random sample of urine) were determined. Ceratenin correcting formula was used for adequacy controlling of urine collecting. Results: Hypocitraturia (56.8%), hypercalciuria (29.4%), hyperuricosuria (26.3%), hyperoxaluria (14.7%), phosphaturia (8.4%) and cystinuria (6.3%) were detected. Also, 54% patients had urinary tract infection. Pain (27.7%), fever (33.3%), irritability and dysuria (62.2%) and hematuria (77.7%) were seen. Positive family history was reported in 23% of patients. Conclusion: Most common clinical manifestations in children with stone were hematuria, dysuria, fever and pain. The common etiology of urolithiasis respectively was hypocitraturia, hypercalciuria, hyperuricosuria, hyperoxaluria, phosphaturia and cystinuria.
Ramin Fallahzadeh, Kasra Esfahani, Abbas Akhavan Sepahi, Nasrin Kamali, Bijan Bambai,
Volume 22, Issue 5 (11-2019)
Abstract
Background and Aim The flavin reductase DszD enzyme is a key enzyme for providing required reduction potential in the bacterial desulfurization process. Considering the low speed of desulfurization process because of low catalytic power of this enzyme, it is necessary to increase the catalytic power of flavin reductase for industrial use of this enzyme as biocatalyst.
Methods & Materials The three-dimensional structure of the flavin reductase DszD enzyme was predicted by a CPHmodel server and its amino acid sequence was searched in the protein data bank to identify the homologue molecules. Based on the alignment of the amino acid sequence and the model molecules, the key residues at the flavin mononucleotide substrate were identified. The key residue of asparagine at position 77 was replaced with phenylalanine using the site-directed mutagenesis method.
Ethical Considerations This study with research ethics code IR.NIGEB.EC.1398.6.24 A has been approved by research ethics committee at National Institute of Genetic Engineering and Biotechnology, Tehran, Iran.
Results The cloning and expression of each of the wild-type and mutant genes were performed separately. The catalytic power of the produced wild-type and mutant enzymes were compared. The catalytic activity measurements showed that the mutant enzyme had a 2.5 fold increase in catalytic power.
Conclusion Replacing phenylalanine with asparagine at position 77 of flavin reductase DszD enzyme leads to an increase in enzyme catalytic power to increase the speed of bacterial desulfurization process.
