Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0003864 (arthritis)
 69,039 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Urease (urea amidohydrolase; EC 3.5.1.5) catalyzes the hydrolysis of urea to yield ammonia and carbamate. The latter compound spontaneously decomposes to yield another molecule of ammonia and carbonic acid. The urease phenotype is widely distributed across the bacterial kingdom, and the gene clusters encoding this enzyme have been cloned from numerous bacterial species. The complete nucleotide sequence, ranging from 5.15 to 6.45 kb, has been determined for five species including Bacillus sp. strain TB-90, Klebsiella aerogenes, Proteus mirabilis, Helicobacter pylori, and Yersinia enterocolitica. Sequences for selected genes have been determined for at least 10 other bacterial species and the jack bean enzyme. Urease synthesis can be nitrogen regulated, urea inducible, or constitutive. The crystal structure of the K. aerogenes enzyme has been determined. When combined with chemical modification studies, biophysical and spectroscopic analyses, site-directed mutagenesis results, and kinetic inhibition experiments, the structure provides important insight into the mechanism of catalysis. Synthesis of active enzyme requires incorporation of both carbon dioxide and nickel ions into the protein. Accessory genes have been shown to be required for activation of urease apoprotein, and roles for the accessory proteins in metallocenter assembly have been proposed. Urease is central to the virulence of P. mirabilis and H. pylori. Urea hydrolysis by P. mirabilis in the urinary tract leads directly to urolithiasis (stone formation) and contributes to the development of acute pyelonephritis. The urease of H. pylori is necessary for colonization of the gastric mucosa in experimental animal models of gastritis and serves as the major antigen and diagnostic marker for gastritis and peptic ulcer disease in humans. In addition, the urease of Y. enterocolitica has been implicated as an arthritogenic factor in the development of infection-induced reactive arthritis. The significant progress in our understanding of the molecular biology of microbial ureases is reviewed.
 ...
PMID:Molecular biology of microbial ureases. 756 14

The local T-cell response to bacterial antigens is involved in the pathogenesis of reactive arthritis (ReA). Here, we have identified a 19-kDa antigen of Yersinia enterocolitica O:9 recognized by Yersinia-specific synovial fluid CD4+ T cells in two patients with Yersinia-induced ReA. N-terminal amino acid sequencing of this protein revealed that it was identical to the 19-kDa urease beta subunit of Y. enterocolitica O:9. This protein has previously been shown to be arthritogenic in preimmunized rats after intra-articular injection. Analysis of the T-cell response to this protein showed that it contains several T-cell epitopes, one of which cross-reacts with other enterobacteria not able to induce ReA. This indicates that the arthritogenicity of the 19-kDa antigen is not a property of the 19-kDa protein alone but is dependent on its expression in bacteria able to induce ReA.
 ...
PMID:Identification of the Yersinia enterocolitica urease beta subunit as a target antigen for human synovial T lymphocytes in reactive arthritis. 840 44

The intestinal microflora was indirectly evaluated in juvenile chronic arthritis (JCA) by analysing enzyme activities--urease, beta-glucosidase and beta-glucuronidase--in faeces. In 18 out of 26 JCA patients, the illness had been diagnosed during the past year. The control group was composed of eight age-matched control patients and 18 family members of JCA patients (3-36 yr). The mean [95% confidence interval (CI)] urease activity, but not the activities of beta-glucosidase and beta-glucuronidase, in faeces from the JCA group differed from that in the control group: 32.3 (26.6-38.1) nmol/min/mg protein vs 24.0 (16.8-31.6), P = 0.07. The difference was more marked in a comparison of JCA patients with family members (P = 0.03). In a subgroup of subjects, the effect of 10 days oral bacteriotherapy with Lactobacillus GG on faecal enzyme activities was then investigated (n = 8 JCA patients, n = 8 control patients). This short-term oral bacteriotherapy reduced the increased urease activity in faeces of JCA patients. Keeping in mind the small number of subjects, it may be inferred from the present results that the increased urease activity in JCA is specific for the disease, suggesting altered intestinal microflora in JCA.
 ...
PMID:Increased bacterial urease activity in faeces in juvenile chronic arthritis: evidence of altered intestinal microflora? 867 Jun 6

The use of nonsteroidal anti inflammatory drugs (NSAID) is associated with an increased risk of peptic ulcer and of ulcer complications. However, the relation between Helicobacter pylori infection and gastroduodenal damage associated with NSAID use is unclear. This study investigated the prevalence of Helicobacter pylori infection in patients with arthritis (n = 85) taking NSAID, trying to find out whether the patients taking NSAID and infected with H. pylori were more likely to have dyspepsia, mucosal damage or chronic active gastritis than those without H. pylori infection. H. pylori was identified by biopsy, rapid urease test and histologic test. Dispeptic symptoms were assessed according to a standardized questionnaire. Gastroduodenal mucosal damage was graded endoscopically (using a modified Lanza scale) and the diagnosis of chronic gastritis was based on the histologic criteria of the Sydney system. The frequency of H. pylori infection was found to increase with age. No statistically significant difference was observed in the presence of damage to gastroduodenal mucosa between the patients with and without H. pylori infection. H. pylori infection was found to be associated with an increased frequency and severity of dyspeptic symptoms in patients with arthritis taking long-term NSAID. Chronic active gastritis was only present in patients with H. pylori infection. H. pylori infection was shown to be associated with an increased frequency and severity of dyspeptic symptoms in patients with arthritis on long-term NSAID therapy, without causing an increased damage to gastroduodenal mucosa.
 ...
PMID:Infection with Helicobacter pylori and long-term use of non-steroidal antiinflammatory drugs. 959 13

The effect of dietary therapy with a human Lactobacillus strain GG (ATCC 53103), bovine colostrum, or bovine immune colostrum with specific antibodies against anaerobic intestinal bacteria on gut defence mechanisms were studied in juvenile chronic arthritis. Thirty patients with juvenile chronic arthritis were randomly allocated to receive a freeze-dried powder of Lactobacillus GG, or bovine colostrum, or bovine immune colostrum, for a two-week period. Immunologic and non-immunologic gut defence mechanisms were indirectly investigated in blood and faecal samples. In patients receiving Lactobacillus GG, the median (interquartile range) frequency of immunoglobulin-secreting cells, determined by enzyme-linked immunospot assay, increased in the IgA class from 1840 (690-2530) to 3480 (1030-13 170)/10(6) cells; p=0.02. Likewise the median (interquartile range) frequency of specific antibody-secreting cells against dietary antigens increased during the Lactobacillus GG therapy in the IgM class from 3.8 (1.4-5.0) to 11.2 (5.0-30.0)/10(6) cells; p=0.02. In addition, Lactobacillus GG therapy decreased the median (interquartile range) activity of faecal urease, which has been associated with mucosal tissue damage, from 40.3 (21.7-54.3) to 28.6 (24.5-49.4) nmol. min(-1) (mg protein)(-1); p=0.10, while, in patients receiving bovine colostrum, faecal urease activity increased (from 42.2 to 80.6; p=0.04). All findings were transient. We suggest that gut defence mechanisms are disturbed in juvenile chronic arthritis and we further suggest that orally administered Lactobacillus GG has a potential to reinforce the mucosal barrier mechanisms in juvenile chronic arthritis.
 ...
PMID:Dietary therapy with Lactobacillus GG, bovine colostrum or bovine immune colostrum in patients with juvenile chronic arthritis: evaluation of effect on gut defence mechanisms. 1763 32

Ureaplasma species are the most prevalent genital Mycoplasma isolated from the urogenital tract of both men and women. Ureaplasma has 14 known serotypes and is divided into two biovars- Ureaplasma parvum and Ureaplasma urealyticum. The organism has several genes coding for surface proteins, the most important being the gene encoding the Multiple Banded Antigen (MBA). The C-terminal domain of MBA is antigenic and elicits a host antibody response. Other virulence factors include phospholipases A and C, IgA protease and urease. Besides genital tract infections and infertility, Ureaplasma is also associated with adverse pregnancy outcomes and diseases in the newborn (chronic lung disease and retinopathy of prematurity). Infection produces cytokines in the amniotic fluid which initiates preterm labour. They have also been reported from renal stone and suppurative arthritis. Genital infections have also been reported with an increasing frequency in HIV-infected patients. Ureaplasma may be a candidate 'co factor' in the pathogenesis of AIDS. Culture and polymerase chain reaction (PCR) are the mainstay of diagnosis. Commercial assays are available with improved turnaround time. Micro broth dilution is routinely used to test antimicrobial susceptibility of isolates. The organisms are tested against azithromycin, josamycin, ofloxacin and doxycycline. Resistance to macrolides, tetracyclines and fluoroquinolones have been reported. The susceptibility pattern also varies among the biovars with biovar 2 maintaining higher sensitivity rates. Prompt diagnosis and initiation of appropriate antibiotic therapy is essential to prevent long term complications of Ureaplasma infections. After surveying PubMed literature using the terms 'Ureaplasma', 'Ureaplasma urealyticum' and 'Ureaplasma parvum', relevant literature were selected to provide a concise review on the recent developments.
...
PMID:Ureaplasma: current perspectives. 2586 69