Heme oxygenase-1 counteracts contrast media-induced endothelial cell dysfunction.

Endothelial cell (EC) dysfunction is involved in the pathogenesis of contrast-induced acute kidney injury, which is a major adverse event following coronary angiography. In this study, we evaluated the effect of contrast media (CM) on human EC proliferation, migration, and inflammation, and determined if heme oxygenase-1 (HO-1) influences the biological actions of CM. We found that three distinct CM, including high-osmolar (diatrizoate), low-osmolar (iopamidol), and iso-osmolar (iodixanol), stimulated the expression of HO-1 protein and mRNA. The induction of HO-1 was associated with an increase in NF-E2-related factor-2 (Nrf2) activity and reactive oxygen species (ROS). CM also stimulated HO-1 promoter activity and this was prevented by mutating the antioxidant responsive element or by overexpressing dominant-negative Nrf2. In addition, the CM-mediated induction of HO-1 and activation of Nrf2 was abolished by acetylcysteine. Finally, CM inhibited the proliferation and migration of ECs and stimulated the expression of intercellular adhesion molecule-1 and the adhesion of monocytes on ECs. Inhibition or silencing of HO-1 exacerbated the anti-proliferative and inflammatory actions of CM but had no effect on the anti-migratory effect. Thus, induction of HO-1 via the ROS-Nrf2 pathway counteracts the anti-proliferative and inflammatory actions of CM. Therapeutic approaches targeting HO-1 may provide a novel approach in preventing CM-induced endothelial and organ dysfunction.

Current concepts of contrast-induced nephropathy: a brief review.

Contrast-induced nephropathy (CIN) is a common hospital-acquired acute kidney injury. Published studies on this condition have dramatically increased in recent years. This article aims to provide a brief literature review. English articles published from 1983 to 2012 were retrieved from PubMed by searching using the term "contrast-induced nephropathy." Patients with CIN were associated with increased resource utilization, prolonged hospital stay, and increased long-term mortality. CIN is defined as a ≥ 0.5 mg/dL rise in serum creatinine or a 25% increase, assessed within 48-72 hours after administration of contrast medium (CM). All patients receiving CM should be evaluated for their CIN risk, especially preexisting kidney disease. The CM should be prewarmed to 37 °C and injected at the lowest possible dose. Repeat injection within 72 hours should be avoided. Either iso-osmolar CM or low-osmolar CM, except ioxaglate or iohexol, can be used in all patients. Iso-osmolar CM iodixanol may be a better choice for high-risk patients with chronic kidney disease requiring intra-arterial administration. Nephrotoxic drugs should be stopped 2 days prior to when the patient undergoes a procedure. All patients receiving CM should be at an optimal volume status. Parenteral isotonic saline without any diuretic should be started 12 hours prior to CM at a rate of 1 mL/kg/h and continued for 24 hours if there is no contraindication. In patients who require shorter volume supplement periods or are at a higher risk, bicarbonate infusion (154 mEq/L, 3 mL/kg/h for 1 hour bolus prior to CM, followed by 1 mL/kg/h for 6 hours) may be used as an alternative to isotonic saline. Oral N-acetylcysteine (600 mg bid, starting on the day prior to the procedure) together with parenteral hydration is suggested for patients at risk. Hemodialysis/hemofiltration is only considered in chronic kidney disease stage 4/5 patients when an access is available. The other medications or techniques for reducing CIN risk are still unclear. CIN is a potentially preventable clinical condition. A careful review of published reports gives us a deeper understanding of CIN and a greater chance of decreasing its risk.

Gene polymorphisms of interleukin-10 and tumor necrosis factor-α are associated with contrast-induced nephropathy.

BACKGROUND/AIMS: Contrast-induced nephropathy (CIN) is the third most common cause of hospital-acquired acute renal failure. However, the pathogenesis of CIN remains unclear. This study evaluated the role of anti-inflammatory cytokine interleukin-10 (IL-10) and pro-inflammatory cytokine tumor necrosis factor-α (TNF-α) gene polymorphisms as CIN susceptibility markers after percutaneous coronary intervention (PCI). METHODS: Four IL-10 tag SNPs (rs1554286, rs3021094, rs3790622, rs1800896) and three TNF-α tag SNPs (rs1799964, rs1800630, rs1800629) were analyzed by MALDI-TOF mass spectrometry in 53 CIN patients and 455 control subjects. Serum IL-10 and TNF-α were detected using ELISA. RESULTS: When compared to controls, the CIN patients showed increased frequencies of CC (rs1554286) and AG+GG (rs1800896) genotypes in IL-10 and GA+AA (rs1800629) genotype in TNF-α (OR = 2.24 (1.13-4.44), p = 0.018; OR = 2.61 (1.30-5.26), p = 0.005, and OR = 2.11 (1.08-4.09), p = 0.025, respectively). Baseline serum IL-10 levels in CIN patients were significantly lower (1.02 ± 1.14 vs. 2.78 ± 4.73 pg/ml, p = 0.008). Patients with CIN had a higher rate of decline in renal function than those without CIN (0.89 ± 1.67 vs. 0.30 ± 0.95 ml/min/1.73 m(2) per month, p = 0.002). Significantly higher rates of decline in creatinine clearance were noted in patients with TNF-α (rs1800629) GA+AA than GG genotype (0.88 ± 1.83 vs. 0.36 ± 0.70, p = 0.03), and with IL-10 (rs1800896) AG+GG than AA genotype (1.28 ± 2.14 vs. 0.33 ± 0.90, p < 0.001). CONCLUSIONS: Gene polymorphisms of IL-10 and TNF-α are associated with CIN risk and long-term renal outcome after PCI. More prospective studies are needed to confirm our results.

Immune response and protective efficacy of live attenuated Salmonella vaccine expressing antigens of Mycobacterium avium subsp. paratuberculosis against challenge in mice.

Mycobacterium avium subsp. paratuberculosis (MAP) causes chronic granulomatous enteritis in ruminants that leads to diarrhea and eventually death. Existing vaccines have proven useful in limiting disease progression but have not been effective in preventing infection. To address this problem we constructed an attenuated Salmonella (ΔyejE; ΔssaV) strain harboring a plasmid that expressed a fusion protein comprised of the Salmonella Type III secretion system (T3SS) effector SopE and MAP antigens (85A, 85B, SOD, 74F) and evaluated its potential as vaccine candidate against MAP infection in mice. Of various SopE-MAP fusion proteins analyzed, only SopE104-Ag85A C-terminal(202-347)-SOD N-terminal(1-72)-Ag85B C-terminal(173-330) and SopE104-74F(1-148+669-786)were successfully expressed and secreted into culture media as revealed by western blot analysis. Mice immunized with attenuated Salmonella (ΔyejE; ΔssaV) harboring the SopE104-Ag85A C-terminal(202-347)-SOD N-terminal(1-72)-Ag85B C-terminal(173-330) and SopE104-74F(1-148+669-786)plasmid generated a potent and long lasting Th1 response characterized by production of IFN-γ. The cytokine profile varied at various time points after immunization and challenge, which showed down regulation of Th2 cytokines (IL-4, IL-10) and up-regulation of proinflammatory cytokines (IL-12 and IL-17). Further, the immune response correlated with protection as revealed by reduced bacterial load and improved histopathology of spleen and liver, which showed fewer granulomas and lower numbers of acid-fast bacilli as compared to PBS controls. Interestingly, vaccination with antigens mixed with Ribi adjuvant (Agmix+Ribi) imparted better protection than the attenuated salmonella vectored vaccine. Thus, priming with a live recombinant Salmonella strain that secretes MAP antigens represents a promising approach that could lead to development of an efficacious and cost effective vaccine for Johne's disease.

Immunogenicity and protective efficacy of the Mycobacterium avium subsp. paratuberculosis attenuated mutants against challenge in a mouse model.

Johne's disease (JD), caused by Mycobacterium avium subsp. paratuberculosis (MAP), results in serious economic losses worldwide especially in cattle, sheep and goats. To control the impact of JD on the animal industry, an effective vaccine with minimal adverse effects is urgently required. In order to develop an effective vaccine, we used allelic exchange to construct three mutant MAP strains, leuD, mpt64 and secA2. The mutants were attenuated in a murine model and induced cytokine responses in J774A.1 cell. The leuD mutant was the most obviously attenuated of the three constructed mutant strains. Our preliminary vaccine trial in mice demonstrated different levels of protection were induced by these mutants based on the acid-fast bacilli burden in livers and spleens at 8 and 12 weeks postchallenge. In addition, vaccination with leuD mutant induced a high level of IFN-γ production and significant protective efficacy in both the reduction of inflammation and clearance of acid-fast bacilli, as compared with the mock vaccinated group.

Resistin induces monocyte-endothelial cell adhesion by increasing ICAM-1 and VCAM-1 expression in endothelial cells via p38MAPK-dependent pathway.

Resistin, firstly reported as an adipocyte-specific hormone, is suggested to be an important link between obesity and diabetes. Recent studies have suggested an association between resistin and atherogenic processes. The adhesion of circulating monocytes to endothelial cells is a critical step in the early stages of atherosclerosis. The purpose of the present study was to investigate the effect of resistin on the adhesion of THP-1 monocytes to human umbilical vein endothelial cells (HUVECs) and the underlying mechanism. Our results showed that resistin caused a significant increase in monocyte adhesion. In exploring the underlying mechanisms of resistin action, we found that resistin-induced monocyte adhesion was blocked by inhibition of p38MAPK activation using SB203580 and SB202190. Furthermore, resistin increased the expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) by HUVECs and these effects were also p38MAPK-dependent. Resistin-induced monocyte adhesion was also blocked by monoclonal antibodies against ICAM-1 and VCAM-1. Taken together, these results show that resistin increases both the expression of ICAM-1 and VCAM-1 by endothelial cells and monocyte adhesion to HUVECs via p38MAPK-dependent pathways.

Immunostimulatory and antigen delivery properties of liposomes made up of total polar lipids from non-pathogenic bacteria leads to efficient induction of both innate and adaptive immune responses.

Novel liposomes prepared from total polar lipids of non-pathogenic bacteria, viz. Leptospira biflexa serovar Potac (designated leptosomes) and Mycobacterium smegmatis (designated smegmosomes) were evaluated for their adjuvant effects with various antigen presenting cells (APCs), viz. murine macrophage cell line, J774A.1 and bone marrow derived dendritic cells (BMDCs). These liposomes induced strong membrane fusion as evident from resonance energy transfer (RET) assays and effectively transferred the fluorescent probe to the membrane of these APCs. Moreover, both vesicles caused significant activation of APCs as revealed by release of proinflammatory cytokines (IL-6, IL-12, TNF-α) and enhanced expression of co-stimulatory signals and maturation markers (CD80, CD86, MHCII), which was significantly higher for smegmosomes as compared to leptosomes. Additionally, activation of APCs by liposomes correlated with their ability to stimulate allospecific T cell proliferation and IFN-γ release. In contrast, conventional PC/chol liposomes failed to fuse and induced only a very low level of APC activation. Interestingly, the stimulatory activity of these lipid vesicles was restricted to APCs as they did not cause any significant activation or mitogenic effect on lymphocytes (B and T cells) in vitro. Overall, the activation of APCs by both leptosomes and smegmosomes correlated with activation of strong humoral and cell mediated immune responses in C57/BL6 mice to entrapped ovalbumin (OVA) and was significantly higher than those induced by conventional liposomes and alum, which failed to activate cytotoxic T lymphocytes (CTLs). Taken together these results demonstrate the adjuvant potential of these novel lipid vesicles that may simultaneously induce both innate and adaptive immune responses due to their immune stimulatory and antigen delivery properties.

Evaluation of immune responses and protective efficacy in a goat model following immunization with a coctail of recombinant antigens and a polyprotein of Mycobacterium avium subsp. paratuberculosis.

The protective efficacy of four recombinant antigens (85A, 85B, superoxide dismutase [SOD], and a fusion polypeptide [Map74F]) of Mycobacterium avium subsp. paratuberculosis (MAP) along with the adjuvant dimethydioctadecyl ammonium bromide (DDA) was assessed in a goat challenge model. Animals were immunized with the four antigens with adjuvant DDA (Group I, eight goat kids) or without the adjuvant (Group II, eight goat kids) or adjuvant only (Group III, nine goat kids). Animals were boostered 3 weeks after the primary vaccination and challenged 3 weeks after the booster. Significant antigen-specific lymphoproliferation was observed in the immunized animals 3 weeks after the booster immunization. This response increased further at 4 weeks after the booster. Similarly, antigen-specific IFN-gamma responses increased in the immunized animals 3 weeks after the booster. The response was significantly higher for 85A and Map74F at 10 weeks after primary vaccination (APV) in Group I animals compared to the other two groups. CD4+ T-cell populations were higher in the vaccinated animals from 6 to 10 weeks APV than those of the control animals. A significant increase in recombinant antigen-specific IFN-gamma gene expression was detected in the vaccinated animals. At necropsy (38 weeks APV), our multicomponent subunit vaccine imparted a significant protection in terms of reduction of MAP burden in target organs as compared to sham-immunized goats. This study indicates that our multicomponent subunit vaccine induced a good Th1 response and conferred protection against MAP infection in a goat challenge model.

Immune responses in mice to Mycobacterium avium subsp. paratuberculosis following vaccination with a novel 74F recombinant polyprotein.

Johne's disease (JD) is a chronic infectious disease of ruminants caused by Mycobacterium avium subsp. paratuberculosis (MAP). Here, we report the cloning and expression of a 74kDa recombinant polyprotein (Map74F) and its protective efficacy against MAP infection in mice. Map74F was generated by the sequential linkage of the ORFs of the approximately 17.6-kDa C-terminal fragment of Map3527 to the full-length ORF of Map1519, followed at the C-terminus with approximately 14.6-kDa N-terminal portion of Map3527. Mice immunized with Map74F had a significant IgG1 response but not IgG2a. In immunized animals, the IgG1/IgG2a ratio increased until 4 weeks after MAP challenge. The ratio decreased from 8 weeks indicating a shift to a Th1 response. Antigen specific IFN-gamma response, CD3+ and CD4+ T cells increased significantly in immunized mice. Following challenge, MAP burden was significantly lower in liver, spleen and mesenteric lymph nodes of immunized animals compared to control animals indicating protection against MAP infection. This was further evident by the improved liver and spleen pathology of the immunized animals, which had fewer granulomas and lower numbers of acid-fast bacilli. Results of this study indicated that immunization of mice with Map74F protected mice against MAP infection.

Vaccination with recombinant Mycobacterium avium subsp. paratuberculosis proteins induces differential immune responses and protects calves against infection by oral challenge.

We previously reported the in vitro cellular immune responses to recombinant antigens (rAgs) of Mycobacterium avium subsp. paratuberculosis (MAP). Here we report the differential immune responses and protective efficacy of four rAgs of MAP (85A, 85B, 85C, and superoxide dismutase (SOD)) used with two adjuvants (monophosphoryl lipid A (MPLA) containing synthetic trehalose dicorynomycolate, cell wall skeleton (MPLA) and bovine IL-12), against MAP challenge in calves. Group I was administered the four rAgs with MPLA and IL-12. Group II was administered the four rAgs and MPLA. Group III received MPLA and IL-12, and Group IV MPLA. rAgs induced significant lymphoproliferative responses in vaccinated animals (Groups I and II). All the rAgs induced significant IFN-gamma production from 11 to 23 wk after primary vaccination (APV), except for SOD. Significant increases were noted in CD3(+), CD4(+), CD8(+), CD21(+), CD25(+), and gammadelta(+) cells against all four rAgs in vaccinated animals. rAg-specific expression of IL-2, IL-12p40, IFN-gamma and TNF-alpha was significantly higher in the two vaccinated groups. Culture results found 4/8 animals in Group I, 3/8 animals in Group II, and 3/4 animals in Groups III and IV were positive for MAP in one or more tissues. Among the seven positive animals in Groups I and II, all but one had had <10CFU. Isolation was confined to one tissue in these animals, except in one animal in which MAP was isolated from two tissues. In the control groups (III and IV), MAP was cultured from up to five different tissues with >250CFU. Preliminary data from this study indicates that all four rAgs induced a good Th1 response and conferred protection against MAP infection in calves.

In vitro cellular immune responses to recombinant antigens of Mycobacterium avium subsp. paratuberculosis.

Five recombinant antigens (Ags; 85A, 85B, 85C, superoxide dismutase [SOD], and 35-kDa protein) were purified from Mycobacterium avium subsp. paratuberculosis and evaluated for their ability to stimulate peripheral blood mononuclear cells (PMBCs) from fecal-culture-positive cows (low and medium shedders) and culture-negative healthy cows. Recombinant Ags 85A, 85B, and 85C induced significant lymphocyte proliferation as well as the production of gamma interferon (IFN-gamma), interleukin-2 (IL-2), IL-12, and tumor necrosis factor alpha (TNF-alpha), but not IL-4, from low and medium shedders. The 85 antigen complex did not stimulate PMBC proliferation from culture-negative healthy cows. The 35-kDa protein also induced significant lymphocyte proliferation as well as the production of IFN-gamma and IL-4 from low and medium shedders. CD4(+) T cells and CD25(+) (IL-2R) T cells were stimulated the most by 85A and 85B, while the 35-kDa protein primarily stimulated CD21(+) B cells involved in humoral immune responses. Interestingly, SOD was less immunostimulatory than other antigens but strongly induced gammadelta(+) T cells, which are thought to be important in the early stages of infection, such as pathogen entry. These data provide important insight into how improved vaccines against mycobacterial infections might be constructed.

Antibiotic treatment of experimentally Borrelia burgdorferi-infected ponies.

The objective of this study is to determine whether doxycycline, ceftiofur or tetracycline could be effectively used to treat equine Lyme disease. Ponies experimentally infected with Borrelia burgdorferi by tick exposure were treated with doxycycline, ceftiofur or tetracycline for 4 weeks (28 days). Doxycyline and ceftiofur treatment were inconsistent in eliminating persistent infection in this experimental model. However, tetracycline treatment seems to eliminate persistent infection. Although serum antibody levels to B. burgdorferi in all ponies declined gradually after antibiotic treatment, three out of four ponies treated with doxycline and two out of four ponies treated with ceftiofur, serum KELA titers were raised again 3 month after treatment was discontinued. Five months after antibiotic treatment, tissues aseptically collected at necropsy from ponies with increased antibody levels after antibiotic treatment also showed culture positive to B. burgdorferi in various post-mortem tissues. However, all four-tetracycline treatment ponies showed a negative antibody level and culture negative from post-mortem tissues. Untreated infected ponies maintained high KELA titers throughout the study and were tissue culture positive.

Infective endocarditis in maintenance hemodialysis patients: fifteen years' experience in one medical center.

BACKGROUND: Infective endocarditis (IE) is a serious infectious condition, with high morbidity and mortality in hemodialysis (HD) patients. This study was undertaken to determine the IE risk factors in maintenance HD patients, and the mortality risk factors. METHODS: We retrospectively reviewed all IE cases of maintenance HD patients at our center over the past 15 yrs (the study group). Regular HD patients without IE in the same period were used as the control group. The basic data of the two groups were analyzed to determine IE risk factors in HD patients. The in-hospital parameters of survival and mortality in the study group patients were used for mortality risk factors analysis. RESULTS: There were 18 definite, and two possible, IE diagnoses in the study group and no cases in the 268 controls. There was no significant difference in age, sex, diabetes, hypertension, underlying malignancy, previous cerebral vascular accident (CVA) history, and calcium multiplied by phosphate product. There was a significant difference between the two groups (study group vs. controls) in pacemaker implant history (15 vs. 1.1%, p<0.01), previous heart surgery history (15 vs. 0.4%, p<0.01), congestive heart failure (CHF) (50 vs. 10.4%, p<0.05), duration on maintenance HD (12.9+/-19.1 vs. 57.9+/-42.3 months, p<0.001), serum albumin at the time of admission (2.91+/-0.40 vs. 3.96+/-0.52 g/dL, p<0.001). There were more patients dialyzed via non-cuffed dual-lumen catheters in the study group (55 vs. 0%, p<0.001), and fewer patients dialyzed via arteriovenous fistula (AVF) (25 vs. 87.7%, p<0.001). The mortality in HD patients with IE was high (60%), especially in patients with methicillin-resistant Staphylococcus aureus (MRSA) endocarditis (100%). The most common pathogen was S. aureus (n=12). MRSA was more common than methicillin-susceptible S. aureus (MSSA) (67 vs. 33%). Univariant analysis of in-hospital clinical parameters for mortality revealed no significant difference in age, diabetes, dual-lumen catheter implantation, serum albumin, time to diagnosis, and time to antibiotic use. Borderline statistical significance was noted in serum C-reactive protein (CRP) (p=0.051), and blood glucose level (p=0.056). There were more IE cases due to MRSA in the mortality group than in the survival group (8 vs. 0 cases, p=0.013), but fewer cases due to MSSA (0 vs. 4 cases, p=0.050). CONCLUSIONS: IE should be considered in HD patients with the following risk factors, which include previous heart surgery or pacemaker implantation, shorter HD duration, and especially for patients dialyzed via dual-lumen catheters. The in-hospital clinical parameters including CRP and blood sugar level can offer information concerning prognosis. Since MRSA has increased in recent years and is associated with high mortality, strategies for prevention and treatment require development.

Tacrolimus-associated hemolytic uremic syndrome: a case analysis.

BACKGROUND: Tacrolimus is an effective organ transplantation immunosuppressant. Hemolytic uremic syndrome (HUS) is a rare but severe complication of tacrolimus. METHODS: We report a case of tacrolimus-associated HUS and review the 15 previously reported cases. RESULTS: The results of the 16 cases indicated that tacrolimus-associated HUS is more frequent in females (56.3%), with the mean age at onset of 41.3 years. Forty-four percent of cases received renal transplantations. The average time from the first tacrolimus dose to HUS onset was 7.1 months. Prevalence was between 0.14.7%. The tacrolimus trough level did not predict the prognosis. Seven patients (43.7%) had improved graft function after treatment, including anticoagulation and antiplatelet therapy, reduction or discontinuation of tacrolimus, switch to cyclosporine (CyA), plasma exchange (PE) and dialysis. Five patients (31.3%) died and four patients (25%) lost their graft in spite of the above treatment. Mortality risk factors for transplant recipients with tacrolimus-associated HUS included: (1) non-renal transplant recipients (100% vs. 36.4%, p = 0.034); (2) lower peak serum Cr (2.58 +/- 1.23 vs. 6.16 +/- 1.96, p < 0.002); (3) liver dysfunction (60% vs. 0, p < 0.02); (4) higher serum lactate dehydrogenase (LDH) level (3119 +/- 1019 vs. 982 +/- 522, p < 0.001). A lower platelet count carried borderline mortality risk (29500 +/- 14480 vs. 59625 +/- 25584, p = 0.057). CONCLUSIONS: HUS should be included in the differential diagnosis of renal function deterioration in patients on tacrolimus post-organ transplantation. Frequent renal function monitoring and appropriate treatment should be performed aggressively to decrease morbidity and mortality, especially in patients with risk factors.

Lipoprotein glomerulopathy associated with psoriasis vulgaris: report of 2 cases with apolipoprotein E3/3.

Lipoprotein glomerulopathy (LPG) is a rare disease, characterized by a special histology, including dilated glomerular capillaries filled with pale-stained and meshlike lipoprotein thrombi. It always presents with proteinuria or nephrotic syndrome. Although hyperlipidemia is not always seen, most patients have type III hyperlipoproteinemia with apolipoprotein (apo) E2/3 phenotyping. Although the clinical feature of LPG is rarely described, LPG associated with other glomerulopathy, including IgA nephropathy, membranous nephropathy, and lupus nephritis, has been documented. Until now, there have been no reports of psoriasis vulgaris associated with LPG. The authors present 2 cases of LPG with apo E3/3 genotyping associated with psoriasis vulgaris. The first patient was a 65-year-old woman who presented with nephrotic syndrome with daily urinary protein loss of 9.05 g and itchy erythematous scaly plaques on her trunk and lower limbs for 1 year. The renal biopsy results showed LPG, and the skin biopsy results showed psoriasis. The second patient was a 50-year-old man with history of psoriasis over his trunk and 4 limbs for 30 years. He also presented with nephrotic syndrome with daily urinary protein loss of 7.55 g. The renal biopsy results also showed LPG. The genotype of apo E showed E3/3, and lipoprotein electrophoresis showed a type III hyperlipoproteinemia-like pattern in both cases. The authors suggest that presence of apo E3/3 genotype cannot rule out the diagnosis of type III hyperlipoproteinemia and LPG. Besides, LPG should be included in the differential diagnosis of psoriatic patients with nephrotic syndrome, especially in Asian patients who show poor response to traditional therapy. Renal biopsy should be performed to make the definitive diagnosis.

Antineutrophil cytoplasmic antibody-negative pauci-immune crescentic glomerulonephritis associated with rheumatoid arthritis: An unusual case report.

Clinically relevant renal lesions in rheumatoid arthritis (RA) are not common. More often renal involvement is related to complications of therapy than the disease itself. The most common forms of primary renal disease in RA are membranous glomerulonephropathy and a pure mesangial proliferative glomerulonephritis. Some studies have described the association between crescentic glomerulonephritis (crescentic GN) and RA, but they were all found to be perinuclear antineutrophil cytoplasmic antibody (p-ANCA) positive. However, RA associated with ANCA negative pauci-immue crescentic GN has not been reported. This is a case report of a 37-year-old female with RA who initially presented with general oedema and acute deterioration of renal function. The renal biopsy revealed ANCA negative pauci-immune crescentic GN. The patient was treated with steroid pulse and plasmapheresis, but not cyclophosphamide because of severe urosepsis. Despite the use of aggressive therapy, her renal function was not improved and she underwent maintenance haemodialysis thereafter. Because ANCA negative crescentic GN may occur in RA patients without frank systemic vasculitis, but with severe clinical manifestation, a heightened suspicion for a relatively 'silent' crescentic GN would have led to the correct diagnosis and appropriate treatment.

Cloning and characterization of a Helicobacter bizzozeronii urease gene cluster.

The urease gene cluster from Helicobacter bizzozeronii was cloned and sequenced. A genomic library was constructed in a lambda-ZAPII vector using TSP5091-digested H. bizzozeronii chromosomal DNA. Four overlapping recombinant bacteriophages carrying the H. bizzozeronii urease genes were identified by using a fragment of H. bizzozeronii ureB as a probe. Sequence analysis of two clones (pHB1 and pHB3) revealed seven open reading frames encoding proteins with predicted masses of 26.5, 60.3, 21.7, 19.5, 28.6, 21.7 and 29.6 kDa representing the structural genes, Urease A and B and its accessory genes, urease I, E, F, G and H, respectively. In addition, three open reading frames upstream of the ureA gene encoding a putative tRNA transferase, a putative Glucose inhibited division protein B (GidB) and a protein with unknown function were also identified. A clone (pHB5) containing a complete urease gene cluster was constructed. The homologue analysis revealed that UreA polypeptide exhibited 64-90% identity to that of Helicobacter heilmanii, Helicobacter felis, Helicobacter pylori, Helicobacter mustelae and Helicobacter hepaticus. UreB polypeptides exhibited 76.8-96% identity to that of H. heilmanii, H. felis, H. pylori, H. mustelae and H. hepaticus. The UreI, E, F, G and H also showed 44-86% identity to that of H. pylori. Among these accessory genes, UreE had a lowest percentage identity to that of H. pylori.

Cloning and characterization of an iron regulated locus, iroA, in Salmonella enterica serovar Choleraesuis.

To identify genes belonging to the Ferric update regulator (Fur) regulon of Salmonella enterica serovar Choleraesuis, the Fur titration assay (FURTA) was used to screen a genomic library for Fur promoters and iron-regulated genes. Fifteen FURTA positive clones were identified from this assay. DNA sequence analysis of these clones showed that 11 out of 15 clones had a Fur binding site (Fur box), and 6 of these clones showed homology to the iron-regulated genes of S. enterica serovar Typhi and/or E. coli. One of these clones (pSC4) was homologous to the iroB gene of the iroA locus of S. enterica serovar Typhi. The iroA locus of S. enterica serovar Choleraesuis was cloned from a lambda-dash library and subjected to DNA sequencing. The complete nucleotide sequence of 9848 bp of the iroA locus of S. enterica serovar Choleraesuis consists of iroB, C, D, E and N genes, which are transcriptionally regulated by Fur. The amino acid sequence of IroB, C, D, E and N was 95%, 86, 89, 96 and 96% identity to that of S. enterica serovar Typhi. The IroN gene was homologous to the family of TonB-dependent outer membrane receptors and the putative virulence factor, IroNE. coli, of the extraintestinal pathogenic E. coli. The convalescent porcine sera contained antibodies against the three major iron-regulated outer membrane proteins of S. enterica serovar Choleraesuis. An insertional inactivation of the iroN gene of S. enterica serovar Choleraesuis by allelic exchange resulted in the loss of expression of the 78 kDa protein. However, this mutant had a similar LD50 to mice compared to the parent strain when given intraperitoneally.