Displaying publications 21 - 40 of 55 in total

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  1. Sujeewa, A.K.W., Norrakiah, A.S., Laina, M.
    MyJurnal
    Vibrio parahaemolyticus is prevalent in tropical marine environment in all seasons and can cause seafood-borne gastroenteritis. A total of 251 suspected isolates were tested including 60 from frozen shrimp, 50 from cultured live shrimp, 67 from sediments of culture ponds and 74 from water were subjected to polymerase chain reaction (PCR) targeting the toxR gene for confirmation as V. parahaemolyticus. Of the 128 toxR positive isolates, 15% of the isolates from culture environment (from live shrimp, sediments and water) and 7% of frozen shrimp samples were positive for the tdh and trh genes. Since urease production could be a marker of trh but not tdh in V. parahaemolyticus, a total of 189 of the 251 suspected V. parahaemolyticus isolates were tested for urease production and 41% of the isolates were found to be positive for urease production. However not all urease positive strains of V. parahaemolyticus were positive for either tdh or trh genes. Detection of virulent strains in shrimp culture environment in Malaysia suggests a probable risk for health of people consuming raw shrimp.
    Matched MeSH terms: Urease
  2. Athar Abbasi M, Raza H, Aziz-Ur-Rehman, Zahra Siddiqui S, Adnan Ali Shah S, Hassan M, et al.
    Bioorg Chem, 2019 03;83:63-75.
    PMID: 30342387 DOI: 10.1016/j.bioorg.2018.10.018
    Present work aimed to synthesize some unique bi-heterocyclic benzamides as lead compounds for the in vitro inhibition of urease enzyme, followed by in silico studies. These targeted benzamides were synthesized in good yields through a multi-step protocol and their structures were confirmed by IR, 1H NMR, 13C NMR, EI-MS and elemental analysis. The in vitro screening results showed that most of the ligands exhibited good inhibitory potentials against the urease. Chemo-informatics analysis envisaged that all these compounds obeyed the Lipinski's rule. Molecular docking results showed that 7h exhibited good binding energy value (-8.40 kcal/mol) and was bound within the active region of urease enzyme. From the present investigation, it was inferred that some of these potent urease inhibitors might serve as novel templates in drug designing.
    Matched MeSH terms: Urease
  3. Rosaida MS, Goh KL
    JUMMEC, 2000;5:11-16.
    Many tests are available for the diagnosis of H. pylori infection. Broadly they can be divided into invasive- endoscopy biopsy based tests and non-invasive tests. Of the endoscopy biopsy based tests the rapid urease tests (RUT) have been found to be the most convenient, accurate and inexpensive tests and they have therefore been recommended by several consensus panels and working parties as the test of choice during endoscopy. Several RUTS are available; some are commercial: CLO test, Pyloritek, Helicobacter urease test, H. yylori test and others- "homemade". We strongly recommend the "homemade" 1 min rapid urease test using an unbuffered solution as originally described by Arvind et al. This test has been shown to be easy to prepare, inexpensive and accurate on field-testing. Several factors affect the accuracy of the RUT. The larger the size of biopsy samples, the quicker is the postive reaction time. With the CLO test, warming the tests to 37'C has also been shown to hasten the reaction time. The effect of blood on the RUT poses an important problem in testing. It is vitally important to determine the H. yylori status in patients with bleeding peptic ulcers as the recurrence of bleeding has been shown to be markedly reduced or virtually abolished with H. yylori eradication. While the results of studies have not been entirely consistent, it is likely that presence of blood does reduce the sensitivity of the RUT. It is therefore sensible that in patients with bleeding ulcers, the RUT should not be the sole endoscopy biopsy test used and that samples should also be taken for histological examination.
    Matched MeSH terms: Urease
  4. Alqasaimeh M, Heng LY, Ahmad M, Raj AS, Ling TL
    Sensors (Basel), 2014 Jul 22;14(7):13186-209.
    PMID: 25054632 DOI: 10.3390/s140713186
    A new silica-gel nanospheres (SiO2NPs) composition was formulated, followed by biochemical surface functionalization to examine its potential in urea biosensor development. The SiO2NPs were basically synthesized based on sol-gel chemistry using a modified Stober method. The SiO2NPs surfaces were modified with amine (-NH2) functional groups for urease immobilization in the presence of glutaric acid (GA) cross-linker. The chromoionophore pH-sensitive dye ETH 5294 was physically adsorbed on the functionalized SiO2NPs as pH transducer. The immobilized urease determined urea concentration reflectometrically based on the colour change of the immobilized chromoionophore as a result of the enzymatic hydrolysis of urea. The pH changes on the biosensor due to the catalytic enzyme reaction of immobilized urease were found to correlate with the urea concentrations over a linear response range of 50-500 mM (R2 = 0.96) with a detection limit of 10 mM urea. The biosensor response time was 9 min with reproducibility of less than 10% relative standard deviation (RSD). This optical urea biosensor did not show interferences by Na+, K+, Mg2+ and NH4+ ions. The biosensor performance has been validated using urine samples in comparison with a non-enzymatic method based on the use of p-dimethylaminobenzaldehyde (DMAB) reagent and demonstrated a good correlation between the two different methods (R2 = 0.996 and regression slope of 1.0307). The SiO2NPs-based reflectometric urea biosensor showed improved dynamic linear response range when compared to other nanoparticle-based optical urea biosensors.
    Matched MeSH terms: Urease/chemistry
  5. Saeedfar K, Heng LY, Ling TL, Rezayi M
    Sensors (Basel), 2013;13(12):16851-66.
    PMID: 24322561 DOI: 10.3390/s131216851
    A novel method for the rapid modification of fullerene for subsequent enzyme attachment to create a potentiometric biosensor is presented. Urease was immobilized onto the modified fullerene nanomaterial. The modified fullerene-immobilized urease (C60-urease) bioconjugate has been confirmed to catalyze the hydrolysis of urea in solution. The biomaterial was then deposited on a screen-printed electrode containing a non-plasticized poly(n-butyl acrylate) (PnBA) membrane entrapped with a hydrogen ionophore. This pH-selective membrane is intended to function as a potentiometric urea biosensor with the deposition of C60-urease on the PnBA membrane. Various parameters for fullerene modification and urease immobilization were investigated. The optimal pH and concentration of the phosphate buffer for the urea biosensor were 7.0 and 0.5 mM, respectively. The linear response range of the biosensor was from 2.31 × 10-3 M to 8.28 × 10-5 M. The biosensor's sensitivity was 59.67 ± 0.91 mV/decade, which is close to the theoretical value. Common cations such as Na+, K+, Ca2+, Mg2+ and NH4+ showed no obvious interference with the urea biosensor's response. The use of a fullerene-urease bio-conjugate and an acrylic membrane with good adhesion prevented the leaching of urease enzyme and thus increased the stability of the urea biosensor for up to 140 days.
    Matched MeSH terms: Urease/chemistry*
  6. Ulianas A, Heng LY, Ahmad M
    Sensors (Basel), 2011;11(9):8323-38.
    PMID: 22164078 DOI: 10.3390/s110908323
    New acrylic microspheres were synthesised by photopolymerisation where the succinimide functional group was incorporated during the microsphere preparation. An optical biosensor for urea based on reflectance transduction with a large linear response range to urea was successfully developed using this material. The biosensor utilized succinimide-modified acrylic microspheres immobilized with a Nile blue chromoionophore (ETH 5294) for optical detection and urease enzyme was immobilized on the surface of the microspheres via the succinimide groups. No leaching of the enzyme or chromoionophore was observed. Hydrolysis of the urea by urease changes the pH and leads to a color change of the immobilized chromoionophore. When the color change was monitored by reflectance spectrophotometry, the linear response range of the biosensor to urea was from 0.01 to 1,000 mM (R2 = 0.97) with a limit of detection of 9.97 μM. The biosensor response showed good reproducibility (relative standard deviation = 1.43%, n = 5) with no interference by major cations such as Na+, K+, NH4+ and Mg2+. The use of reflectance as a transduction method led to a large linear response range that is better than that of many urea biosensors based on other optical transduction methods.
    Matched MeSH terms: Urease/chemistry
  7. Lee M, Lambros C
    Am J Trop Med Hyg, 1988 Nov;39(5):421-6.
    PMID: 3057927
    A visual, enzyme-linked immunosorbent assay using urease (ELISA-U) as the enzyme marker was adapted for rapid detection of antibody against Plasmodium falciparum. Flat-bottom, 96-well microtiter plates were coated with P. falciparum soluble antigen obtained by saponin and NP-40 treatment of parasite cultures. Antibody was detected by successive incubations with test sera, urease-conjugated rabbit-human antibody, and urease substrate. Reactive sera developed a definite and easily visualized purple color. Sera from patients with single infections of P. vivax or P. ovale were unreactive. No cross-reactivity was noted with sera from patients with rheumatoid arthritis, filariasis, amebiasis, schistosomiasis, dengue, scrub typhus, leptospirosis, or toxoplasmosis. The procedure can be performed at room temperature and completed within 1 hr. The sensitivity of the assay is comparable to that of the indirect fluorescent antibody test at all but the lowest dilutions tested.
    Matched MeSH terms: Urease*
  8. Seraj F, Kanwal, Khan KM, Khan A, Ali M, Khalil R, et al.
    Mol Divers, 2021 Feb;25(1):143-157.
    PMID: 31965436 DOI: 10.1007/s11030-019-10032-x
    Novel ibuprofen derivatives 1-19 including ibuprofen hydrazide 1, and substituted thiourea derivatives 2-19 were synthesized and characterized by EI-MS, FAB-MS, HREI-MS, HRFAB-MS, 1H-, and 13C-NMR spectroscopic techniques. The synthetic molecules 1-19 were examined for their in vitro urease inhibition and were found to display a diversified degree of inhibitory potential in the range of IC50 = 2.96-178 μM as compared to the standard thiourea (IC50 = 21.32 ± 0.22 μM). Out of nineteen, thirteen derivatives 2-4, 6, 7, 9, 11-15, 17, and 18 demonstrated remarkable inhibitory activity with IC50 values of 2.96 ± 1.11 to 16.1 ± 1.07 μM, compound 5 exhibited moderate inhibition with IC50 value of 37.3 ± 0.41 μM, whereas, compounds 1, 8, and 10 demonstrated weak inhibition against urease enzyme. Almost all structural features are participating in the activity; however, limited structure-activity relationship was discussed on the basis of different structural features, i.e., different functional groups and their positions at aryl part. In addition, molecular docking study was performed in order to understand the ligands binding interactions with the active site of urease enzyme.
    Matched MeSH terms: Urease/antagonists & inhibitors*
  9. Wang W, Zhou F, Chang Y, Cui J, He D, Du J, et al.
    Bull Environ Contam Toxicol, 2020 Mar;104(3):380-385.
    PMID: 31932904 DOI: 10.1007/s00128-020-02786-0
    In this study, three soil amendments (inorganic, liming, or organic-inorganic materials) were used in a Cd-contaminated purple field soil to investigate their impacts on soil Cd availability, enzyme (urease, catalase, sucrase, and acid phosphatase) activities, microbial biomass (carbon/nitrogen) and type (bacteria, fungi, and actinomycetes) in mustard and corn trials. Results showed that soil amendments generally decreased soil exchangeable Cd, fungi and bacterial populations while increasing the activities of all the four soil enzymes tested, microbial biomass carbon and populations of actinomycetes (p  0.05) whereas stronger effects appeared in soil organic matter and available nutrients (nitrogen, phosphorous and potassium; p 
    Matched MeSH terms: Urease/analysis
  10. Said RM, Cheah PL, Chin SC, Goh KL
    Eur J Gastroenterol Hepatol, 2004 Feb;16(2):195-9.
    PMID: 15075994
    BACKGROUND: The gastric biopsy urease test is the most frequently used test for the diagnosis of Helicobacter pylori infection in routine gastrointestinal endoscopy practice. In Malaysia up to recently, only one commercial biopsy urease test was available: the CLO test (Ballard Medical Products, Draper, Utah, USA). Large endoscopy units use their own 'homemade' unbuffered ultra rapid urease test for diagnosis of H. pylori infection.

    OBJECTIVE: To compare the accuracy and reaction time of a new biopsy urease test, Pronto Dry (Medical Instruments Corporation, Solothurn, Switzerland) and the CLO test in the diagnosis of H. pylori infection.

    METHODS: Consecutive patients presenting with dyspepsia to the endoscopy unit, University of Malaya Medical Centre were recruited for the study. Patients who were previously treated for H. pylori infection or who had received antibiotics, proton pump inhibitors or bismuth compounds in the preceding 4 weeks were excluded. H. pylori diagnosis was made based on the ultra rapid urease test and histological examination of gastric biopsies. Four antral and four corpus biopsies were taken for this purpose from all patients. A diagnosis of H. pylori infection was made when both the ultra rapid urease test and histology were positive in either the antral or corpus biopsies. A negative diagnosis of H. pylori was made when both tests from antral and corpus biopsies were all negative. Another four antral and four corpus biopsies (two each) were taken for the Pronto Dry and CLO tests. The Pronto Dry and CLO tests were stored and performed according to the manufacturer's instruction.

    RESULTS: Two hundred and eight patients were recruited in the study. Eighty-six of the patients were males and 122 were females. The mean age was 46.3 years with a range of 15-82 years. The results for both the Pronto Dry and the CLO tests were completely concordant with sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of 98.1%, 100%, 100%, 98.1% and 99%, respectively. The Pronto Dry test showed a faster reaction time to positive compared with the CLO test, with 96.2% positive reaction by 30 min versus 70.8% and 100% positive reaction time by 55 min versus 83%. The colorimetric change was also more distinct with the Pronto Dry test compared with the CLO test.

    CONCLUSIONS: Both the Pronto Dry and the CLO tests were highly accurate for the diagnosis of H. pylori infection. The Pronto Dry test showed a quicker positive reaction time and the positive colour change was more distinct.

    Matched MeSH terms: Urease/analysis*
  11. Taha M, Rahim F, Ullah H, Wadood A, Farooq RK, Shah SAA, et al.
    Sci Rep, 2020 06 30;10(1):10673.
    PMID: 32606439 DOI: 10.1038/s41598-020-67414-7
    In continuation of our work on enzyme inhibition, the benzofuran-based-thiazoldinone analogues (1-14) were synthesized, characterized by HREI-MS, 1H and 13CNMR and evaluated for urease inhibition. Compounds 1-14 exhibited a varying degree of urease inhibitory activity with IC50 values between 1.2 ± 0.01 to 23.50 ± 0.70 µM when compared with standard drug thiourea having IC50 value 21.40 ± 0.21 µM. Compound 1, 3, 5 and 8 showed significant inhibitory effects with IC50 values 1.2 ± 0.01, 2.20 ± 0.01, 1.40 ± 0.01 and 2.90 ± 0.01 µM respectively, better than the rest of the series. A structure activity relationship (SAR) of this series has been established based on electronic effects and position of different substituents present on phenyl ring. Molecular docking studies were performed to understand the binding interaction of the compounds.
    Matched MeSH terms: Urease/antagonists & inhibitors*
  12. Rahim F, Taha M, Ullah H, Wadood A, Selvaraj M, Rab A, et al.
    Bioorg Chem, 2019 10;91:103112.
    PMID: 31349115 DOI: 10.1016/j.bioorg.2019.103112
    Alpha-amylase and urease enzyme over expression endorses various complications like rheumatoid arthritis, urinary tract infection, colon cancer, metabolic disorder, cardiovascular risk, and chronic kidney disease. To overcome these complications, we have synthesized new arylhydrazide bearing Schiff bases/thiazolidinone analogues as α-amylase and urease inhibitors. The analogues 1a-r were evaluated for α-amylase inhibitory potential. All analogues were found active and show IC50 value ranging between 0.8 ± 0.05 and 12.50 ± 0.5 μM as compare to standard acarbose (IC50 = 1.70 ± 0.10 μM). Among the synthesized analogs, compound 1j, 1r, 1k, 1e, 1b and 1f having IC50 values 0.8 ± 0.05, 0.9 ± 0.05, 1.00 ± 0.05, 1.10 ± 0.10, 1.20 ± 0.10 and 1.30 ± 0.10 μM respectively showed an excellent inhibitory potential. Analogs 2a-o were evaluated against urease activity. All analogues were found active and show IC50 value ranging between 4.10 ± 0.02 and 38.20 ± 1.10 μM as compare to standard thiourea (IC50 = 21.40 ± 0.21 μM). Among the synthesized analogs, compound 2k, 2a, 2h, 2j, 2f, 2e, 2g, 2b and 2l having IC50 values 4.10 ± 0.02, 4.60 ± 0.02, 4.70 ± 0.03, 5.40 ± 0.02, 6.70 ± 0.05, 8.30 ± 0.3, 11.20 ± 0.04, 16.90 ± 0.8 and 19.80 ± 0.60 μM respectively showed an excellent inhibitory potential. All compounds were characterized through 1H, 13C NMR and HR-EIMS analysis. Structure activity relationship of the synthesized analogs were recognized and confirmed through molecular docking studies.
    Matched MeSH terms: Urease/antagonists & inhibitors*; Urease/metabolism
  13. Isaac IO, Al-Rashida M, Rahman SU, Alharthy RD, Asari A, Hameed A, et al.
    Bioorg Chem, 2019 02;82:6-16.
    PMID: 30267972 DOI: 10.1016/j.bioorg.2018.09.032
    Urease is a bacterial enzyme that is responsible for virulence of various pathogenic bacteria such as Staphylococcus aureus, Proteus mirabilis, Klebsiella pneumoniae, Ureaplasma urealyticum, Helicobacter pylori and Mycobacterium tuberculosis. Increased urease activity aids in survival and colonization of pathogenic bacteria causing several disorders especially gastric ulceration. Hence, urease inhibitors are used for treatment of such diseases. In search of new molecules with better urease inhibitory activity, herein we report a series of acridine derived (thio)semicarbazones (4a-4e, 6a-6l) that were found to be active against urease enzyme. Molecular docking studies were carried out to better comprehend the preferential mode of binding of these compounds against urease enzyme. Docking against urease from pathogenic bacterium S. pasteurii was also carried out with favorable results. In silico ADME evaluation was done to determine drug likeness of synthesized compounds.
    Matched MeSH terms: Urease/antagonists & inhibitors*; Urease/chemistry
  14. Zaman K, Rahim F, Taha M, Sajid M, Hayat S, Nawaz M, et al.
    Bioorg Chem, 2021 10;115:105199.
    PMID: 34329995 DOI: 10.1016/j.bioorg.2021.105199
    Synthesis of quinoline analogs and their urease inhibitory activities with reference to the standard drug, thiourea (IC50 = 21.86 ± 0.40 µM) are presented in this study. The inhibitory activity range is (IC50 = 0.60 ± 0.01 to 24.10 ± 0.70 µM) which displayed that it is most potent class of urease inhibitor. Analog 1-9, and 11-13 emerged with many times greater antiurease potential than thiourea, in which analog 1, 2, 3, 4, 8, 9, and 11 (IC50 = 3.50 ± 0.10, 7.20 ± 0.20, 1.30 ± 0.10, 2.30 ± 0.10, 0.60 ± 0.01, 1.05 ± 0.10 and 2.60 ± 0.10 µM respectively) were appeared the most potent ones among the series. In this context, most potent analogs such as 1, 3, 4, 8, and 9 were further subjected for their in vitro antinematodal study against C. elegans to examine its cytotoxicity under positive control of standard drug, Levamisole. Consequently, the cytotoxicity profile displayed that analogs 3, 8, and 9 were found with minimum cytotoxic outline at higher concentration (500 µg/mL). All analogs were characterized through 1H NMR, 13C NMR and HR-EIMS. The protein-ligand binding interaction for most potent analogs was confirmed via molecular docking study.
    Matched MeSH terms: Urease/antagonists & inhibitors*; Urease/metabolism
  15. Taha M, Ismail NH, Imran S, Wadood A, Rahim F, Riaz M
    Bioorg Med Chem, 2015 Nov 15;23(22):7211-8.
    PMID: 26507431 DOI: 10.1016/j.bmc.2015.10.017
    Disulfide analogs (1-20) have been synthesized, characterized by HR-MS, (1)H NMR and (13)C NMR and screened for urease inhibitory potential. All compounds were found to have varied degree of urease inhibitory potential ranging in between 0.4 ± 0.01 and 18.60 ± 1.24 μM when compared with standard inhibitor thiourea with IC50 19.46 ± 1.20 μM. Structure activity relationship has been established. The binding interactions of compounds with enzyme were confirmed through molecular docking. All the synthesized compounds 1-20 are new. Our compounds are cheaply synthesizable with high yield and can further be studied to discovery lead compounds. We further, tested for carbonic anhydrase, PDE1 and butyrylcholinesterase but they show no activity. On the other hand we evaluated all compounds for cytotoxicity they showed no toxicity.
    Matched MeSH terms: Urease
  16. Ahmed Z, Aziz S, Hanif M, Mohiuddin SG, Ali Khan SH, Ahmed R, et al.
    J Pharm Bioallied Sci, 2020 04 10;12(2):192-200.
    PMID: 32742119 DOI: 10.4103/jpbs.JPBS_222_19
    Background: This study aimed to evaluate the phytochemicals screening of Erythrina suberosa (Roxb) bark and to analyze the enzymatic activities of its various organic fractions.

    Materials and Methods: Crude methanolic fraction of E. suberosa (Roxb) bark and its respective fractions were screened for the presence of different phytochemicals with different reagents. On the basis of increasing order of polarity, different organic solvents were used to obtain different fractions. Enzymatic studies were performed on crude methanolic extract of the plant. All the assays were performed under standard in vitro conditions.

    Results: The phytochemical analysis shows the presence of alkaloids, phenols, triterpenoids, phytosterols, and flavonoids. Phenolic compounds and flavonoids are the major constituents of the plant. In anticholinesterase assay, the percent inhibition of standard drug (eserine) was 91.27 ± 1.17 and the half maximal inhibitory concentration (IC50) was 0.04 ± 0.0001. For α-glucosidase inhibition, the IC50 value for Dichloromethane fraction was 8.45 ± 0.13, for Methanol fraction it was 64.24 ± 0.15, and for aqueous fraction it was 42.62 ± 0.17 as compared with standard IC50 that is 37.42 (acarbose). Furthermore, results show that all fractions have potential against anti-urease enzyme, but DCM fraction of crude aqueous extract has significant IC50 value (45.26 ± 0.13) than other fractions.

    Conclusion: Keeping in view all the results, it is evident that the plant can be used in future for formulating effective drugs against many ailments. Secondary metabolites and their derivatives possess different biological activities, for example, .g. flavonoids in cancer, asthma, and Alzheimer. Furthermore, the extracts of this plant can be used in their crude form, which is an addition to the complementary and alternative treatment strategies.

    Matched MeSH terms: Urease
  17. Omoregie AI, Ong DEL, Nissom PM
    Lett Appl Microbiol, 2019 Feb;68(2):173-181.
    PMID: 30537001 DOI: 10.1111/lam.13103
    Biocalcification through the use of ureolytic bacteria and biochemical activities has evolved in recent decades into a fervent resourceful effective technology suitable for soil stabilization, crack repair and bioremediation. Extensive studies have been carried out on numerous ureolytic bacterial species isolated from soils and sewage samples. However, very limited attention has been given to limestone caves with natural calcite formations as a possible source for isolation of ureolytic bacteria. In this study, bacterial isolates were recovered from limestone cave samples to determine their suitability for biocalcification. Twenty-seven morphologically distinct bacterial isolates were identified by partial 16S rRNA gene sequencing and their various genetic diversity was characterized according to their phylogenetic affiliations. Based on the molecular identification, Sporosarcina was the most abundant genus among all the ureolytic isolates, while the rest belonged to Pseudogracilibacillus and Bacillus genera. Analytical analysis on urease measurement showed that urease activities for the isolates ranged from 1·130 to 21·513 mol urea hydrolysed per minute, with isolate NB33 achieving the highest value and TSB4 achieving the lowest value. The estimated CaCO3 precipitates for the isolates ranged from 4·04 to 17·26 mg ml-1 , with isolate NB30 achieving the highest value and TSB20 achieving the lowest value. The findings in this study demonstrated that the ureolytic bacteria from limestone caves are promising bio-calcifying agents. SIGNIFICANCE AND IMPACT OF THE STUDY: Ureolytic bacteria continues to play an important role as microbial tools used in geotechnical engineering for soil biocalcification. Microbial strains with the ability to produce urease enzyme and induce calcium carbonate mineral are often isolated from soil, water and sludge samples. However, screening for these essential microbes from extreme regions such as caves are rarely investigated. In this study, native bacteria which were isolated from limestone cave samples are identified and characterized. The findings suggested that these ureolytic bacterial isolates have the potential to serve as suitable alternative microbial agents for soil strengthening and stabilization.
    Matched MeSH terms: Urease
  18. Iqbal DM, Wong LS, Kong SY
    Materials (Basel), 2021 Apr 23;14(9).
    PMID: 33922871 DOI: 10.3390/ma14092175
    The rapid development of the construction sector has led to massive use of raw construction materials, which are at risk of exhaustion. The problem is aggravated by the high demand for cement as binding powder and the mass production of clay bricks for construction purposes. This scenario has led to high energy consumption and carbon emissions in their production. In this regard, bio-cementation is considered a green solution to building construction, because this technology is environmentally friendly and capable of reducing carbon emissions, thus slowing the global warming rate. Most of the previously published articles have focused on microbiologically induced calcium carbonate precipitation (MICP), with the mechanism of bio-cementation related to the occurrence of urea hydrolysis as a result of the urease enzymatic activity by the microbes that yielded ammonium and carbonate ions. These ions would then react with calcium ions under favorable conditions to precipitate calcium carbonate. MICP was investigated for crack repair and the surface treatment of various types of construction materials. Research on MICP for the production of binders in construction materials has become a recent trend in construction engineering. With the development of cutting edge MICP research, it is beneficial for this article to review the recent trend of MICP in construction engineering, so that a comprehensive understanding on microbial utilization for bio-cementation can be achieved.
    Matched MeSH terms: Urease
  19. Alfizah, H., Rizal, A.M., Isa, M.R., Aminuddin, A., Jasmi, A.Y., Ramelah, M.
    Medicine & Health, 2010;5(1):13-21.
    MyJurnal
    Helicobacter pylori has been implicated as an aetiologic agent for type B chronic gastritis, peptic ulcer and gastric cancer. It is considered the most common bacterial infection in the world with approximately 50% of the population being infected. The majority of infected individuals are asymptomatic, with some developing gastritis only. However, chronic infection with H. pylori without antibiotic treatment predisposes infected individuals to the development of gastric cancer. The aim of this study is to determine active H. pylori infection among patients with symptoms of dyspepsia using three combinations of diagnostic methods. In this report, we studied 1,376 consecutive patients who underwent upper gastrointestinal endoscopy at Universiti Kebangsaan Malaysia Medical Center (UKMMC) for dyspepsia from the period January 1999 to December 2002. The classification of patient’s diagnosis was assessed by endoscopic and histological examination. The H. pylori status was determined by rapid urease test, histological examination or H. pylori culture. Presence of H. pylori infection was confirmed in 30.8% of patients with dyspepsia. H. pylori infection was more prevalent in older patients and in males compared to females. Patients with severe gastroduodenal diseases were more commonly infected with H. pylori. There was a significant difference in H. pylori prevalence among the different ethnic groups. Indians had the highest infection rate (45.4%), followed by Chinese (36.8%) and the lowest were seen in Malays (18.3%). This finding on determination of active H. pylori infection among patients with dyspepsia is consistent with serological studies that showed racial differences in H. pylori prevalence. However, the pattern of H. pylori infection does not reflect the prevalence of severe gastroduodenal diseases among different ethnic groups.
    Matched MeSH terms: Urease
  20. Abbasi MA, Raza H, Rehman AU, Siddiqui SZ, Nazir M, Mumtaz A, et al.
    Drug Res (Stuttg), 2019 Feb;69(2):111-120.
    PMID: 30086567 DOI: 10.1055/a-0654-5074
    In this study, a new series of sulfonamides derivatives was synthesized and their inhibitory effects on DPPH and jack bean urease were evaluated. The in silico studies were also applied to ascertain the interactions of these molecules with active site of the enzyme. Synthesis was initiated by the nucleophilic substitution reaction of 2-(4-methoxyphenyl)-1-ethanamine (1: ) with 4-(acetylamino)benzenesulfonyl chloride (2): in aqueous sodium carbonate at pH 9. Precipitates collected were washed and dried to obtain the parent molecule, N-(4-{[(4-methoxyphenethyl)amino]sulfonyl}phenyl)acetamide (3): . Then, this parent was reacted with different alkyl/aralkyl halides, (4A-M: ), using dimethylformamide (DMF) as solvent and LiH as an activator to produce a series of new N-(4-{[(4-methoxyphenethyl)-(substituted)amino]sulfonyl}phenyl)acetamides (5A-M: ). All the synthesized compounds were characterized by IR, EI-MS, 1H-NMR, 13C-NMR and CHN analysis data. All of the synthesized compounds showed higher urease inhibitory activity than the standard thiourea. The compound 5 F: exhibited very excellent enzyme inhibitory activity with IC50 value of 0.0171±0.0070 µM relative to standard thiourea having IC50 value of 4.7455±0.0546 µM. Molecular docking studies suggested that ligands have good binding energy values and bind within the active region of taget protein. Chemo-informatics properties were evaluated by computational approaches and it was found that synthesized compounds mostly obeyed the Lipinski' rule.
    Matched MeSH terms: Urease/antagonists & inhibitors*; Urease/metabolism; Urease/chemistry
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