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Query: UMLS:C0034186 (pyelonephritis)
 6,144 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Renal scars have been considered to occur in later stages of chronic pyelonephritis. In our experimental pyelonephritis model, bacteria which possessed mannose-sensitive (MS) pili on the surface promoted renal scarring following inoculation to the renal parenchyma. Polyethylene glycol-modified superoxide dismutase (PEG-SOD) and 2-O-octadecylascorbic acid (CV3611) significantly suppressed scarring when administered orally or parenterally during the early stage of kidney infection with MS-piliated bacteria. These findings suggest that the superoxide and other active oxygens play an important role in renal scarring following infection and that PEG-SOD and CV3611 may be agents capable of preventing renal scarring following bacterial pyelonephritis.
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PMID:Antioxidant effect on renal scarring following infection of mannose-sensitive-piliated bacteria. 134 8

Escherichia coli is the most frequent cause of pyelonephritis. Its possible virulence factors include the ability to adhere and colonize the urinary tract, an important initiating factor in all urinary tract infections (UTIs). The importance of P fimbriae in this adhesion is stressed and the evidence for its importance in pyelonephritis is presented in epidemiologic studies of patients, as well as in animal studies. It appears that both host receptor density and the nonsecretor state is responsible for susceptibility to urinary tract infection. Vesicoureteral reflux can be responsible for ascending upper tract infection, but infection with P-fimbriated E coli may lead to ascending pyelonephritis without reflux because of the paralytic effect of lipid A on ureteral peristaltic activity. Renal ischemia leads to renal damage following infection by reperfusion damage due to the release of superoxide. Experimentally, this ischemic damage can be prevented by allopurinol, a xanthine oxidase inhibitor. The acute inflammatory response can produce renal damage because of the respiratory burst of phagocytosis, which while killing phagocytosed bacteria also damages renal tubules. An amelioration of the inflammatory response by treatment with superoxide dismutase or corticosteroids has been shown to modulate renal damage. Vaccination with P fimbriae has been shown experimentally to prevent the initiation of the disease. However, since vaccines are not clinically available, the clinical and animal studies on therapy of acute disease are stressed. Acute pyelonephritis during the first 3 years of life more often produced the renal damage that could lead to end-stage renal disease.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Etiology and pathophysiology of pyelonephritis. 167 Sep 5

The role of superoxide in scar formation following renal infection caused by mannose-sensitive (MS) piliated strains of bacteria was studied in the experimental pyelonephritis model using female Sprague-Dawley rats. The MS piliated strain stimulated renal scarring to a significantly greater extent than either the non-piliated or MR-piliated strain. Modulation of leukocytes by administering cyclophosphamide to induce neutropenia and colchicine to inhibit leukocyte migration was effective in preventing renal scarring. Treatment with superoxide dismutase during the early stage of infection was also effective in preventing scar formation. Finally, the production of superoxide by rat leukocytes was significantly larger following stimulation by MS piliated than either the non-piliated or MR piliated strains. These observations suggest that superoxide released from leukocytes plays a critical role in the development of renal scarring following a bacterial infection, especially by MS piliated strains.
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PMID:Role of superoxide in renal scarring following infection by mannose-sensitive piliated bacteria. 168 8

Two new strains of Serratia marcescens were constructed by the gene manipulation method from the clinical isolate US 46, which has two kinds of pili--mannose-sensitive (MS) and mannose-resistant (MR) ones--on the cell surface. After cloning the genes of the MS and MR pili, either the MS or the MR gene was transferred to the nonpiliated Escherichia coli, and MS- or MR-piliated strains were obtained. In the experimental pyelonephritis model of rats, MS- or MR-piliated bacteria were inoculated directly to the renal parenchyma, and the following results were obtained. MS-piliated rather than MR-piliated strains stimulated severe scarring of the kidney, and this scarring was suppressed by treatment with colchicine or superoxide dismutase (SOD) during an early stage of the infection. These findings suggest that MS-piliated bacteria stimulated polymorphonuclear leukocytes, which released large amounts of superoxide resulting in renal scarring. SOD was hoped to be a drug capable of preventing renal scarring, and such a result was successfully obtained.
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PMID:Suitability of colchicine and superoxide dismutase for the suppression of renal scarring following an infection with bacteria showing mannose-sensitive pili. 168 29

The enzyme superoxide dismutase affords a protective effect from renal scarring secondary to acute pyelonephritis in primates. To investigate the relationship between renal superoxide dismutase content and age we selected formalin-fixed normal human renal tissue from subjects of varying age, ranging from premature infant to adult, for immunostaining with human anti-superoxide dismutase antibody using the peroxidase-antiperoxidase technique. Sections that demonstrated acute pyelonephritis were immunostained for comparison. Immunostaining for superoxide dismutase was detected consistently in the proximal tubular cell cytoplasm in all specimens regardless of subject age. Superoxide dismutase was not detected in other segments of the nephron. In kidneys that demonstrated acute pyelonephritis we detected enhanced immunostaining in the proximal tubules, as well as increased background staining related to the inflammatory cells present. These results in conjunction with recent demonstrations of proximal tubular cell endocytosis of bacteria suggest that superoxide dismutase has an important role in mediating the initial events of pyelonephritis within the proximal tubular cell.
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PMID:Role of superoxide dismutase in the pathogenesis of pyelonephritis: immunological localization of superoxide dismutase in human renal tissues. 266 28

Reactive oxygen species have been found to be responsible for the tissue injury caused in experimental pyelonephritis in mice. The extent of lipid peroxidation (as assayed by malondialdehyde formation) was found to be increased significantly (p less than .001) in the infected group as compared to the normal mice. Superoxide dismutase and catalase (oxygen free radical scavengers) showed a significant decrease (p less than .001) in the extent of lipid peroxidation even in the presence of infection. Dimethyl sulfoxide, a hydroxyl ion scavenger, was however found to be effective only at 4 and 7 days postinfection (p less than .001). Allopurinol, an inhibitor of xanthine oxidase, did not significantly (p greater than .05) inhibit the formation of lipid peroxides, even upto 7 days postinfection. There was a significant decrease (p less than .05) in the activities of renal brush border membrane enzymes used as markers of renal tissue damage (i.e. alkaline phosphatase, leucine amino-peptidase and gamma-glutamyl transpeptidase) in the infected group as compared to the normal group. In the presence of superoxide dismutase, dimethylsulfoxide and catalase except allopurinol, the activities of all the enzymes but maltase were found to be increased significantly (p less than .05) as compared to the infected group. There was a significant increase (p less than .01) in the bacterial count in the presence of superoxide dismutase and DMSO in infected mice as compared to the infected control mice. However, no significant difference was observed in the catalase and allopurinol treated groups.
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PMID:Effect of various oxygen free radical scavengers in preventing tissue injury caused by Escherichia coli in pyelonephritic mice. 305 56

Ascending acute pyelonephritis was produced in monkeys by infusion of bacteria through a ureteral catheter to the point of intrarenal reflux. This led to a significant inflammatory response with death of renal tubular cells in the area of the tubular granulocytes and bacteria. We gave superoxide dismutase, and found that the inflammatory response was decreased and fewer tubular cells were killed. Ultrastructural change was also decreased in tubular cells adjoining phagocytosing neutrophils. This suggests that renal damage following a bacterial infection may be due to the production and release of superoxide into the tubular lumen during phagocytosis. We believe that it is the initial event which may lead to the eventual loss of renal tissue and function called chronic pyelonephritis.
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PMID:Immunology of pyelonephritis in the primate model. V. Effect of superoxide dismutase. 675 91

Renal scarring is considered to develop in the later stages of chronic pyelonephritis. In our experimental model of pyelonephritis, bacteria with mannose-sensitive (MS) pili on their surface promoted renal scarring following inoculation into the renal parenchyma. The administration of cyclophosphamide to induce leukopenia and of superoxide dismutase to inactivate superoxide released from polymorphonuclear leukocytes (PMN) at the infection site suppressed any renal scarring following the infection. Conversely, the administration of phorbol myristate acetate at an early stage of infection significantly enhanced the renal scarring. These findings suggest that the PMNs which infiltrate the infection site and the superoxide they release play an important role in any renal scarring following infection with MS-piliated bacteria.
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PMID:Renal scarring is enhanced by phorbol myristate acetate following infection with bacteria with mannose-sensitive pili. 793 44

Pyelonephritis is the most common urinary tract infection in females, but the pathogenetic mechanisms are not well understood. Reactive oxygen species (ROS) have been implicated as cause of injury in several renal diseases. In this study, we have demonstrated the role of ROS in pathogenesis of pyelonephritis in Balb/c mice. A clear correlation between extent of ROS generation and subsequent lipid peroxidation and DNA damage in kidneys was observed during the course of infection, from 2 to 14 days. Activities of brush border membrane marker enzymes were also significantly altered. Administration of antioxidants, superoxide dismutase, catalase and dimethylsulfoxide significantly reversed the histopathological changes, reduced the extent of lipid peroxidation in renal brush border membrane, and also reversed the altered enzyme activities to near normal situation. These results clearly suggest that interaction of ROS with various cellular organelles in kidneys has a significant deleterious effect, and this could be the underlying mechanism for renal dysfunction in pyelonephritis.
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PMID:Reactive oxygen species-mediated tissue injury in experimental ascending pyelonephritis. 877 Sep 45

To investigate the pathogenicity of the hyphal form of Candida in pyelonephritis a Candida albicans strain, assuming only the yeast form but not the hyphal form when induced by ultraviolet mutagenesis, and a revertant strain from this mutant strain showing bimorphism were compared in a rat experimental model with regard to the incidence of ascending Candida pyelonephritis and the grade of inflammation. To increase the frequency of pyelonephritis unilateral incomplete ureteral stenosis was created. The revertant strain assuming the hyphal form showed a significantly (p < 0.01) higher frequency of pyelonephritis as compared with the mutant strain not assuming this form, and the grade of inflammation was also higher in the revertant strain group. Also, higher renal tissue and serum levels of both lipid peroxide and superoxide dismutase, which are related to marked renal oxidant injury, tended to be correlated with the degree of neutrophil infiltration in the acute phase. These findings suggest that the hyphal form plays an important role in the development of C. albicans pyelonephritis and also that the oxygen radicals from neutrophils appearing at the sites of inflammation play a major part in the further extension of inflammatory lesions.
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PMID:Experimental study of ascending Candida albicans pyelonephritis focusing on the hyphal form and oxidant injury. 918 32


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