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Sample records for acute glomerulonephritis agn

  1. An approach to the child with acute glomerulonephritis.

    PubMed

    Welch, Thomas R

    2012-01-01

    Acute glomerulonephritis (AGN) is a common condition in childhood. Many children with AGN can be managed in the primary care setting. The diagnosis is usually made on the basis of urinary findings, especially the presence of red blood cell casts. One of the most important initial investigations is determining the complement C3 level; hypocomplementemia is most characteristic of post streptococcal AGN, while normocomplementemia is most often seen with IgA nephropathy. Children whose AGN is accompanied by significant hypertension or renal insufficiency should be assessed by a specialist immediately. The presence of serious extrarenal signs or symptoms also merits urgent referral. Otherwise, serial followup in the primary care office is appropriate.

  2. Cortical blindness in a child with acute glomerulonephritis.

    PubMed

    Kaarthigeyan, K; Vijayalakshmi, A M

    2012-01-01

    The association between hypertensive encephalopathy and cortical blindness in children with acute glomerulonephritis is extremely rare. We report the case of a 9-year old girl who presented with headache, seizures, altered sensorium, hematuria, and transient cortical blindness as a complication of hypertensive encephalopathy which showed complete reversal following normalization of blood pressure and an underlying post-infectious acute glomerulonephritis was revealed.

  3. Lymphocyte surface markers in acute rheumatic fever and post-streptococcal acute glomerulonephritis.

    PubMed Central

    Williams, R C; Zabriskie, J B; Mahros, F; Hassaballa, F; Abdin, Z H

    1977-01-01

    Lymphocyte cell-surface markers were examined in forty children with acute rheumatic fever (ARF) and twelve with acute post-streptococal glomerulonephritis (AGN) and compared to thirty-six normal controls of similar age. Cell-surface-marker studies included surface Ig using fluorescein-labelled F(ab)2 anti-F(AB')2, IgG aggregate binding cells, and EAC rosettes. T cells were identified both as 'active' rosettes and total E-binding cells. Proportions and absolute numbers of cells bearing surface Ig and Fc receptors were elevated in subjects with AGN (Pless than0-01-0-5), whereas proportions of cells producing EAC rosettes were diminished. Patients with acute rheumatic carditis or chorea showed a substantial elevation in proportions and numbers of active T-cell rosettes (Pless than0-01). Streptococcal antigen binding cells capable of forming rosettes with autologous cells coated with group A streptococcal membranes were elevated in the acute phase of both rheumatic fever and acute glomerulonephritis(Pless than0-01). The majority of such cells were removed by passage over insolubilized Ig-anti-IgG columns and appeared to be B cells. PMID:300301

  4. Acute glomerulonephritis with bacteriuria: a probable etiologic relationship.

    PubMed

    El Said, W; Awad, S; Farid, F; Maged, Z; Fattah, F A; El Maghraby, M

    1979-01-01

    Twenty-one cases of acute glomerulonephritis in children with no previous history of renal disease were studied. Urinary infection with a rising titre of serum agglutinins against the organisms isolated from urine was found in 5 cases. No evidence of previous streptococcal infection was found in these cases. In the meantime all 8 cases with post-streptococcal glomerulonephritis remained without bacteriuria. In one case acute glomerulonephritis followed virus hepatitis, and in the remaining 7 cases the cause of glomerulonephritis was unknown. It is suggested that in predisposed patients the bacteria present in urinary infections might act as antigens starting immunologic reactions in the glomeruli, leading to glomerulonephritis. The final proof of this theory awaits immunofluorescence identification of these antigens in the glomeruli.

  5. Plasmodium vivax malaria associated with acute post infectious glomerulonephritis.

    PubMed

    Kanodia, Kamal V; Vanikar, Aruna V; Kute, Vivek Balkrishna; Trivedi, Hargovind L

    2013-08-01

    Malaria remains a major health problem in many parts of the world leading to high morbidity and mortality related to renal dysfunction and relapsing nature of Plasmodium vivax malaria. Acute renal failure occurs commonly in Plasmodium falciparum malaria, although its rare occurrences have been reported in P. vivax malaria also. We reported a rare case of P. vivax malaria monoinfection associated with acute post infectious glomerulonephritis.

  6. Human parvovirus B19-induced acute glomerulonephritis: a case report.

    PubMed

    Shimohata, Homare; Higuchi, Takashi; Ogawa, Yujiro; Fujita, Shogo; Nagai, Miho; Imaizumi, Masahiro; Maruyama, Hiroshi; Hirayama, Kouichi; Kobayashi, Masaki

    2013-01-01

    Human parvovirus B19 (HPV B19) infection is well known as a cause of erythema infectiosum in children. Acute glomerulonephritis due to HPVB19 infection is rarely observed in adults. Here, we present the case of a 45-year-old female who showed acute glomerulonephritis induced by HPVB19 infection with various autoantibodies. She had proteinuria (175 mg/g creatinine) and hematuria (20-29 erythrocytes per high-power field) in a urinalysis, and various autoantibodies such as antinuclear antibodies, proteinase-3-antineutrophil cytoplasmic antibodies (PR3-ANCA), antiglomerular basement membrane (GBM) antibodies, and anticardiolipin antibodies in a blood examination. A renal biopsy showed that endocapillary proliferative glomerulonephritis comprised of mononuclear cell infiltration. By using immunofluorescence microscopy, IgG, IgA, IgM, C3, C4, and C1q deposits were detected mainly in glomerular capillaries. Electron-dense deposits were detected in the subendothelial area and mesangial area by using electron microscopy. All symptoms and abnormal laboratory data were self-improved. Our patient's case may provide a clue to the etiology of ANCA-associated vasculitis or lupus nephritis.

  7. Concomitant severe normocytic and normochromic anemia in poststreptococcal acute glomerulonephritis.

    PubMed

    Asano, Takeshi; Sudoh, Mariko; Watanabe, Makoto; Fujino, Osamu

    2009-10-01

    Although anemia frequently occurs in poststreptococcal acute glomerulonephritis (PSAGN), severe anemia is rare. We report severe normocytic, normochromic anemia (hematocrit, 19.8%) in PSAGN in a 6-year-old girl with edema, macrohematuria, and proteinuria for 1 month. The potential causes of severe anemia found in this case were: 1) longer duration of massive hematuria from onset of macrohemauria to treatment, 2) a level of erythropoietin much lower than that in cases of iron deficiency anemia, and 3) hemodilution. We speculate that these factors combined to cause an unusual case of severe anemia in PSAGN.

  8. Acute post-infection glomerulonephritis caused by new 'thongs'. A case report.

    PubMed

    O'Donnell, D; Markowitz, S

    1986-04-26

    Acute glomerulonephritis complicated secondary infection in a patient suffering from traumatic blisters caused by new footwear. This unlikely setting for acute glomerulonephritis was made more interesting by its occurrence in an adult in contrast with its more frequent recognition in a child. The age of the patient and the severity of the local symptoms masked the significance of the initial finding of haematuria until deteriorating renal function indicated the diagnosis of concomitant glomerular disease.

  9. HBV-Associated Postinfectious Acute Glomerulonephritis: A Report of 10 Cases

    PubMed Central

    Zhang, Yong; Li, Junxia; Peng, Weihua; Yu, Guoqing; Wang, Liping; Chen, Jian; Zheng, Feng

    2016-01-01

    Postinfectious acute glomerulonephritis (PIGN) may occur after various bacterial and viral infections. Hepatitis B virus (HBV) infection is a cause of chronic glomerulonephritis. We report here 10 cases (ages 7–20 years-old) of chronic HBV carriers with acute glomerulonephritis, with positive glomerular staining of hepatitis B surface antigen, and detectable presence of HBV DNA in the glomeruli. This form of PIGN, HBV-PIGN, has not been previously identified. To further characterize clinical and pathological features of HBV- PIGN, we selected 10 cases of age-matched non-HBV PIGN for comparison. While both HBV associated PIGN and non-HBV PIGN similarly presented as proteinuria, hematuria, and hypertension, there was a trend of higher acute kidney injury and worsened prognosis in HBV-PIGN. 6 months after the onset, 4 patients with HBV associated PIGN did not show improvement from the disease, whereas all patients with non-HBV PIGN had complete or partial recovery. Pathologically, both HBV associated PIGN and non-HBV PIGN showed typical diffuse glomerular endocapillary proliferation, but HBV associated PIGN differed from classical PIGN with much fewer sub-epithelial glomerular “hump-shape” immune complex depositions. In conclusion, we have identified a novel association of HBV infection with acute glomerulonephritis. PMID:27512989

  10. Coexistence of Acute Crescent Glomerulonephritis and IgG4-Related Kidney Disease

    PubMed Central

    Lu, Zeyuan; Yin, Jianyong; Bao, Hongda; Jiao, Qiong; Wu, Huijuan; Wu, Rui; Xue, Qin; Wang, Niansong; Zhang, Zhigang; Wang, Feng

    2016-01-01

    Introduction IgG4-related disease (IgG4-RD) is a fibroinflammatory disorder that may involve almost each organ or system. IgG4-related kidney disease (IgG4-RKD) refers to renal lesions associated with IgG4-RD. The most frequent morphological type of renal lesions is IgG4-related tubulointerstitial nephritis (IgG4-TIN) which is associated with increased IgG4-positive plasma cell infiltration and interstitial fibrosis. Case Report Herein, we present a rare case with coexisting IgG4-RKD and acute crescent glomerulonephritis with concomitant severe tubulointerstitial lesions instead of classic IgG4-TIN. Conclusion IgG4-RKD and acute crescent glomerulonephritis can occur in the same patient. This case may give us a clearer viewpoint of the disease. PMID:27504450

  11. Histologically confirmed superimposition of post-streptococcal acute glomerulonephritis during IgA nephropathy.

    PubMed

    Horita, Yoshio; Tadokoro, Masato; Taura, Koichi; Suyama, Naofumi; Taguchi, Takashi; Miyazaki, Masanobu; Kohno, Shigeru

    2004-12-01

    We describe a 39-year-old Japanese man with post-streptococcal acute glomerulonephritis (PSAGN) super-imposed on long-term immunoglobulin A nephropathy (IgA-N). The histological findings of the first renal biopsy, done at 21 years of age, revealed mild mesangial proliferative glomerulonephritis with mesangial IgA deposition. Nineteen years later, acute nephritic syndrome with hypocomplementemia and an increasing anti-streptolysin O (ASO) titer developed 2 weeks after the onset of an upper respiratory infection. A second renal biopsy revealed severe segmental endocapillary proliferative and exudative glomerulonephritis, with fibrocellular crescents in about 40% of the glomeruli. Immunofluorescence showed that more C3 than IgA was deposited in the mesangium and that the IgA deposits had decreased. Electron microscopy revealed "hump" electron-dense deposits on the epithelial side of the glomerular basement membrane. These features were consistent with PSAGN superimposed on IgA-N. After 2 weeks of observation, blood pressure, C3 level, and ASO titer had returned to normal, although the persisting nephritic syndrome necessitated steroid therapy. Six months after the onset of the acute nephritic syndrome, the patient remained asymptomatic, except for microhematuria.

  12. Endostreptosin: isolation of the probable immunogen of acute post-streptococcal glomerulonephritis (PSGN).

    PubMed Central

    Cronin, W; Deol, H; Azadegan, A; Lange, K

    1989-01-01

    It is now generally accepted that acute post-streptococcal glomerulonephritis (PSGN) is the consequence of the formation of antigen-antibody-complement complexes on the basement membrane of the glomerulus and that the antigen is of streptococcal origin. In cases of acute PSGN a high titre of specific antibodies to a streptococcal cytoplasmic extract can be found at the very beginning of the disease. This cytoplasmic antigen which we called endostreptosin (ESS) is probably the pathogenetic antigen of glomerulonephritis. It is deposited on the subendothelial side of the basement membrane in the first few days of the disease and is rapidly covered by newly-formed and specific antibody and complement with resultant immune injury causing signs and symptoms of symptomatic but also frequently asymptomatic acute glomerulonephritis. To further characterize and isolate ESS we used immunoaffinity chromatography and Western blotting techniques. PAGE analysis of the affinity-isolated ESS revealed the major component to have a molecular weight of approximately 45 kD. Sera from patients with PSGN or sera of rabbits immunized with affinity-isolated ESS reacted by Western blotting with at least one antigenic component with a molecular weight of approximately 45 kD. Normal human sera or the sera of non-immunized rabbits failed to demonstrate activity against this antigen. The basement membranes of the glomeruli of patients with very early PSGN stain with fluorescein-labelled gammaglobulin of patients with glomerulonephritis. This staining can be prevented when these sera are pre-absorbed with ESS but not by pre-absorption with intact cells or cytoplasmic extracts of other bacteria. Images Fig. 1 Fig. 2 Fig. 3 Fig. 5 PMID:2667818

  13. Diffuse alveolar hemorrhage in a patient with acute poststreptococcal glomerulonephritis caused by impetigo.

    PubMed

    Yoshida, Masahiro; Yamakawa, Hideaki; Yabe, Masami; Ishikawa, Takeo; Takagi, Masamichi; Matsumoto, Kei; Hamaguchi, Akihiko; Ogura, Makoto; Kuwano, Kazuyoshi

    2015-01-01

    We herein report a case of pulmonary renal syndrome with nephritis in a 17-year-old boy with diffuse alveolar hemorrhage (DAH) associated with acute poststreptococcal glomerulonephritis (APSGN). The patient exhibited hemoptysis two weeks after developing impetigo, and DAH was diagnosed on bronchoscopy. Respiratory failure progressed, and high-dose methylprednisolone therapy was administered; the respiratory failure regressed immediately after the onset of therapy. Streptococcus pyogenes was detected in an impetigo culture, and, together with the results of the renal biopsy, a diagnosis of APSGN was made. This case demonstrates the effects of high-dose methylprednisolone therapy in improving respiratory failure.

  14. Post-streptococcal acute glomerulonephritis complicated by gouty arthritis: a case report.

    PubMed

    Kuniyoshi, Yasutaka; Kamura, Azusa; Yasuda, Sumie; Tashiro, Makoto

    2015-06-17

    Gouty arthritis is uncommon in childhood and adolescence. On the other hand, there has been no report of cases with development of gouty arthritis with post-streptococcal acute glomerulonephritis (PSAGN) in pediatric patients. Here we report the case of a mildly obese 12-year-old boy with PSAGN complicated by gouty arthritis of the left first metatarsophalangeal joint. On follow-up, it was confirmed that as serum C3 level returned to normal, urinary excretion of uric acid increased and serum uric acid level decreased, thereby resolving the burning pain of the left big toe. In this case, not only did renal insufficiency associate with PSAGN but also mild obesity may have led to hyperuricemia and gouty arthritis. In conclusion, clinicians should be aware that PSAGN may be complicated by gouty arthritis in obese pediatric patients.

  15. IgA-dominant acute poststreptococcal glomerulonephritis with concomitant rheumatic fever successfully treated with steroids: a case report

    PubMed Central

    Rus, Rina R; Toplak, Nataša; Vizjak, Alenka; Mraz, Jerica; Ferluga, Dušan

    2015-01-01

    There are only a few reports of the co-occurrence of acute poststreptococcal glomerulonephritis (APGN) and acute rheumatic fever. We report an unusual case of a 3-year-old boy with nephrotic syndrome and acute renal failure with the transitional need for peritoneal dialysis, biopsy-proven atypical IgA-dominant APGN, and concomitant acute rheumatic fever, successfully treated by steroids. Aggressive treatment with pulses of methylprednisolone proved to be successful and we recommend its use in this type of cases. PMID:26718763

  16. Renal Biopsy Findings in Acute Renal Failure in the Cohort of Patients in the Spanish Registry of Glomerulonephritis

    PubMed Central

    López-Gómez, Juan M.; Rivera, Francisco

    2008-01-01

    Background and objectives: Renal biopsy in acute renal failure of unknown origin provides irreplaceable information for diagnosis, treatment, and prognosis. This study analyzed the frequency and clinicopathologic correlations of renal native biopsied acute renal failure in Spain during the period 1994 through 2006. Design, setting, participants, & measurements: Acute renal failure was defined as a rapid deterioration of glomerular filtration rate, with or without oligoanuria or rapidly progressive renal insufficiency, including acute-on-chronic renal failure. Patients who were younger than 15 yr were considered children, those between 15 and 65 yr adults, and those >65 elderly. Results: Between 1994 and 2006, data on 14,190 native renal biopsies were collected from 112 renal units in Spain. Of these, 16.1% (2281 biopsies) were diagnosed with acute renal failure. The prevalence of the main clinical syndromes was different in the three age groups: Biopsy-confirmed acute renal failure in children was 5.7%, in adults was 12.5%, and in elderly increased significantly to 32.9%. The prevalence of biopsy-confirmed acute renal failure according to cause was as follows: Vasculitis, 23.3%; acute tubulointerstitial nephritis, 11.3%; and crescentic glomerulonephritis types 1 and 2, 10.1%. The prevalence of the different causes differed significantly according to age group. Conclusions: The Spanish Registry of Glomerulonephritis provides useful information about renal histopathology in biopsy-confirmed acute renal failure. The prevalence of vasculitis and crescentic glomerulonephritis is high, especially in elderly patients. These data obtained from a national large registry highlight the value of renal biopsy in undetermined acute renal failure. PMID:18354075

  17. Activation of the lectin complement pathway in post-streptococcal acute glomerulonephritis.

    PubMed

    Hisano, Satoshi; Matsushita, Misao; Fujita, Teizo; Takeshita, Morishige; Iwasaki, Hiroshi

    2007-06-01

    The aim of the present study was to elucidate the correlation between complement pathways and clinicopathological findings in post-streptococcal acute glomerulonephritis (PSAGN). Immunohistological staining was performed on renal specimens obtained from 18 patients with PSAGN and 20 controls, using antibodies against IgG, IgA, IgM, C1q, C3c, C4, fibrinogen, factor B, C4-binding protein (C4-bp), C5b-9, CD59, mannose-binding lectin (MBL) and MBL-associated serine protease-1 (MASP-1). Controls showed no deposition of any antibody. In seven patients, glomerular deposits of C3c, C4, factor B, C4-bp, C5b-9, CD59, MBL and MASP-1 were found. In the remaining 11 patients, glomerular deposits of neither C4 nor MBL/MASP-1 were found, and glomerular deposits of C3c, factor B, C5b-9 and CD59 were evident. C4-bp was detected in seven of these 11 patients. Glomerular deposits of fibrinogen were detected in five of seven patients with MBL/MASP-1 deposits and in only two of 11 patients without MBL/MASP-1 deposits. Hematuria was prolonged in three of seven patients with MBL/MASP-1 deposits through follow up, whereas urinalysis was normal in all patients without MBL/MASP-1 deposits. However, the histological indicators were not different between the two groups. To the authors' knowledge this is the first report to show that complement activation through both the alternative and lectin pathways is evident in some patients with PSAGN. Complement activation is promoted in situ in the glomerulus.

  18. Acute Cardiac Tamponade in a 58-Year-Old Male with Poststreptococcal Glomerulonephritis

    PubMed Central

    Bottinor, Wendy; Fronk, Daniel; Sadruddin, Salima; Foster, Harriet; Patel, Nilang; Prinz, Andreas; Jovin, Ion S

    2016-01-01

    Pericarditis in conjunction with nephritis is an uncommon clinical scenario with a broad differential diagnosis. We present the case of a 58-year-old male who developed nephritis and pericardial effusion with tamponade physiology. In the following, we discuss the differential diagnosis for concomitant nephritis and pericarditis and discuss the work-up performed on our patient. We also review the epidemiology of postinfectious glomerulonephritis in adults and describe previous cases of Streptococcus pyogenes pericarditis in the literature. PMID:27826373

  19. Immune Complex Mediated Glomerulonephritis with Acute Thrombotic Microangiopathy following Newly Detected Hepatitis B Virus Infection in a Kidney Transplant Recipient.

    PubMed

    Salter, Tracey; Burton, Hannah; Douthwaite, Sam; Newsholme, William; Horsfield, Catherine; Hilton, Rachel

    2016-01-01

    Hepatitis B virus (HBV) presents a risk to patients and staff in renal units. To minimise viral transmission, there are international and UK guidelines recommending HBV immunisation for patients commencing renal replacement therapy (RRT) and HBV surveillance in kidney transplant recipients. We report the case of a 56-year-old male who was immunised against HBV before starting haemodialysis. He received a deceased donor kidney transplant three years later, at which time there was no evidence of HBV infection. After a further six years he developed an acute kidney injury; allograft biopsy revealed an acute thrombotic microangiopathy (TMA) with glomerulitis, peritubular capillaritis, and C4d staining. Due to a "full house" immunoprofile, tests including virological screening were undertaken, which revealed acute HBV infection. Entecavir treatment resulted in an improvement in viral load and kidney function. HBV genotyping demonstrated a vaccine escape mutant, suggesting "past resolved" infection that reactivated with immunosuppression, though posttransplant acquisition cannot be excluded. This is the first reported case of acute HBV infection associated with immune complex mediated glomerulonephritis and TMA. Furthermore, it highlights the importance of HBV surveillance in kidney transplant recipients, which although addressed by UK guidelines is not currently practiced in all UK units.

  20. Immune Complex Mediated Glomerulonephritis with Acute Thrombotic Microangiopathy following Newly Detected Hepatitis B Virus Infection in a Kidney Transplant Recipient

    PubMed Central

    Burton, Hannah; Douthwaite, Sam; Newsholme, William; Horsfield, Catherine

    2016-01-01

    Hepatitis B virus (HBV) presents a risk to patients and staff in renal units. To minimise viral transmission, there are international and UK guidelines recommending HBV immunisation for patients commencing renal replacement therapy (RRT) and HBV surveillance in kidney transplant recipients. We report the case of a 56-year-old male who was immunised against HBV before starting haemodialysis. He received a deceased donor kidney transplant three years later, at which time there was no evidence of HBV infection. After a further six years he developed an acute kidney injury; allograft biopsy revealed an acute thrombotic microangiopathy (TMA) with glomerulitis, peritubular capillaritis, and C4d staining. Due to a “full house” immunoprofile, tests including virological screening were undertaken, which revealed acute HBV infection. Entecavir treatment resulted in an improvement in viral load and kidney function. HBV genotyping demonstrated a vaccine escape mutant, suggesting “past resolved” infection that reactivated with immunosuppression, though posttransplant acquisition cannot be excluded. This is the first reported case of acute HBV infection associated with immune complex mediated glomerulonephritis and TMA. Furthermore, it highlights the importance of HBV surveillance in kidney transplant recipients, which although addressed by UK guidelines is not currently practiced in all UK units. PMID:27800206

  1. New trends of an old disease: the acute post infectious glomerulonephritis at the beginning of the new millenium.

    PubMed

    Stratta, Piero; Musetti, Claudio; Barreca, Antonella; Mazzucco, Gianna

    2014-06-01

    The association between acute renal disease and infection has been known since the mid '800s: acute post-infectious glomerulonephritis (PIGN) is a reactive immunological process against the kidney secondary to an infection, classically caused by a Streptococcus. The typical clinical presentation of PIGN is an acute nephritic syndrome with macro- or microscopic hematuria, proteinuria, hypertension, edema and renal function impairment of variable degree. The histology is characterized by an intracapillary glomerular proliferation, but may rarely be associated with an extracapillary proliferation. The classical childhood form is still present nowadays, even with severe cases, in developing countries, while in the last decades it almost disappeared in industrialized countries, where post-infectious GN are often found in elderly patients with multiple comorbidities. These clinical variants are usually related to other infective agents, like Staphylococcus aureus, both methicillin resistant (MRSA) and susceptible, and may be characterized by an IgA-dominant deposition. Kidney biopsy is rarely needed, especially in the child, while in the adult or old patient a biopsy is warranted if there is an atypical presentation or evolution, like rapidly progressive renal failure, absent or delayed function recovery, persisting low C3, nephrotic range proteinuria and persisting high proteinuria. Current therapy strategies rely on culture-guided systemic antibiotics, especially in the old patient, in which MRSA are relatively frequent, support therapy and only in very selected cases on steroids. These latter cases include the rare PIGN with crescents and those with a severe interstitial inflammation.

  2. Ruptured Sinus of Valsalva with Infective Endocarditis Complicated with Post-Infectious Acute Glomerulonephritis: A Rare Case Presentation

    PubMed Central

    Daga, Mradul Kumar

    2016-01-01

    Ruptured Sinus of Valsalva (RSOV) is a rarely seen disease condition. RSOV can have varied presentations from being asymptomatic with just a cardiac murmur to profound hypotension. There has been simultaneous occurrence of RSOV with Infective Endocarditis (IE) in literature. Glomerulonephritis has also been reported in approximately 20% patients with IE. Large amount of proteinuria or decline in kidney functions is rarely encountered and mostly this finding has been incidental on routine evaluation. The co-existence of all the three conditions in a single patient is rare. This case was diagnosed to have RSOV with IE and was also diagnosed with post-infectious glomerulonephritis on renal biopsy. Patient was advised corrective cardiac surgery, but due to financial constraints, patient could not be operated and he died. Here, we report for the first time an unusual presence of both RSOV and sub-aortic membrane with IE complicated by glomerulonephritis. PMID:27891383

  3. Kartagener syndrome associated with mesangioproliferative glomerulonephritis.

    PubMed

    Krishnamurthy, Sriram; Choudhary, Bharat; Rajesh, Nachiappa Ganesh; Ramesh, Ananthakrishnan; Srinivasan, Sadagopan

    2012-05-01

    An 11-year-old girl with clinical features of Kartagener syndrome presented with signs of acute glomerulonephritis. Blood urea and creatinine were mildly elevated and anti-streptolysin O and C3 levels were normal. Renal biopsy demonstrated mesangial proliferation and direct immunofluorescence showed IgM and C3 deposits. This appears to be the first report of Kartagener syndrome in association with mesangioproliferative glomerulonephritis. The literature is reviewed and the possible mechanisms for this association are discussed.

  4. Acute tubular necrosis as a part of vancomycin induced drug rash with eosinophilia and systemic symptoms syndrome with coincident postinfectious glomerulonephritis

    PubMed Central

    Kim, Kyung Min; Sung, Kyoung; Yang, Hea Koung; Kim, Seong Heon; Kim, Hye Young; Ban, Gil Ho; Park, Su Eun; Lee, Hyoung Doo

    2016-01-01

    Drug rash with eosinophilia and systemic symptoms (DRESS) syndrome is a rare and potentially fatal condition characterized by skin rash, fever, eosinophilia, and multiorgan involvement. Various drugs may be associated with this syndrome including carbamazepine, allopurinol, and sulfasalazine. Renal involvement in DRESS syndrome most commonly presents as acute kidney injury due to interstitial nephritis. An 11-year-old boy was referred to the Children's Hospital of Pusan National University because of persistent fever, rash, abdominal distension, generalized edema, lymphadenopathy, and eosinophilia. He previously received vancomycin and ceftriaxone for 10 days at another hospital. He developed acute kidney injury with nephrotic range proteinuria and hypocomplementemia. A subsequent renal biopsy indicated the presence of acute tubular necrosis (ATN) and late exudative phase of postinfectious glomerulonephritis (PIGN). Systemic symptoms and renal function improved with corticosteroid therapy after the discontinuation of vancomycin. Here, we describe a biopsy-proven case of severe ATN that manifested as a part of vancomycin-induced DRESS syndrome with coincident PIGN. It is important for clinicians to be aware of this syndrome due to its severity and potentially fatal nature. PMID:27186222

  5. Glomerulonephritis (For Parents)

    MedlinePlus

    ... salt, and potassium diuretics (medicines that increase urine production) medicines to lower blood pressure (if high blood pressure is a problem) antibiotics (if a bacterial infection is causing glomerulonephritis) steroids ...

  6. Fibrillary glomerulonephritis presenting as crescentic glomerulonephritis

    PubMed Central

    Shah, H. H.; Thakkar, J.; Pullman, J. M.; Mathew, A. T.

    2017-01-01

    Fibrillary glomerulonephritis (FGN) is a rare primary glomerular disease that commonly presents clinically with hypertension, proteinuria, microscopic hematuria, and varying degree of renal insufficiency. Histologically, FGN can present with different patterns of glomerular injury, more commonly mesangioproliferative, membranoproliferative, and membranous nephropathy. While crescent formation has been described in some kidney biopsy series of FGN, crescentic glomerulonephritis pattern of glomerular injury has been rarely described. Optimal therapy and outcomes in FGN presenting with crescentic GN is not currently known. We report an adult patient who presented with massive proteinuria and severe renal failure. The kidney biopsy revealed crescentic FGN (C-FGN). The patient remained dialysis dependent despite immunosuppressive therapy. We also briefly review FGN, and the few reported cases of C-FGN that presented as rapidly progressive or advanced renal failure in the literature. PMID:28356674

  7. Quantitative morphometry of glomerulonephritis with crescents. Diagnostic and predictive value.

    PubMed

    Elfenbein, I B; Baluarte, H J; Cubillos-Rojas, M; Gruskin, A B; Coté, M; Cornfeld, D

    1975-01-01

    Histologic patterns in the glomerular tufts in "Glomerulonephritis with many crescents" take three main forms: (1) compression and sclerosis of glomeruli, (2) necrotizing glomerulitis, and (3) proliferation with or without exudation. In the third group, histologic differentiation between patients with poststreptococcal glomerulonephritis with many crescents (AGN) and those with nonstreptococcal rapidly progressive glomerulonephritis (RPGN) may be impossible. In a retrospective study, quantitative morphometry of glomeruli effectively separated three patients with AGN from two patients with RPGN after the usual histologic and electron microscopic observations had failed. Parameters studied were areas of tufts and crescents and total number of cells and granulocytes in tufts and crescents. Surface areas of tufts and crescents were separately determined by photographing glomeruli, projecting and tracing outlines of tufts and crescents, and cutting out and weighing the tracings. The cell density of glomerular tufts (cell per 1000-sq. mum. area) was significantly greater in AGN than in RPGN when either total cell densities (17.64 plus or minus 0.41 versus 13.63 plus or minus 0.30) or total cells minus granulocytes (16.39 plus or minus 0.50 versus 12.99 plus or minus 0.52) were compared. The cell density in the tufts was 120 and 70 per cent greater than controls in AGN and RPGN, respectively. Exudation of inflammatory cells is contributory but not the major cause of hypercellularity in AGN. Follow-up studies with biopsies showed marked resolution in two of three patients with AGN, with normal blood urea nitrogen levels and focal scarring in the third, whereas the two patients with RPGN had either extensive scarring and reduced renal function or required chronic hemodialysis.

  8. Crescentic glomerulonephritis in children.

    PubMed

    Jardim, H M; Leake, J; Risdon, R A; Barratt, T M; Dillon, M J

    1992-05-01

    Data on patients with crescentic glomerulonephritis (greater than 50% glomeruli with crescents), referred to the Hospital for Sick Children during the past 13 years, were reviewed. Thirty patients (13 male, 17 female) aged 3.7-15.7 years (mean 9.5) were evaluated. Initial clinical features included: oedema (24/30), hypertension (19/30), gross haematuria (15/30), oliguria (15/30) and a decreased glomerular filtration rate (GFR less than 30 ml/min per 1.73 m2) (22/30). Henoch-Schönlein purpura was present in 9 patients, microscopic polyarteritis in 3, polyarteritis nodosa in 1, Wegener's granulomatosis in 1, systemic lupus erythematosus in 1, post-streptococcal glomerulonephritis in 2, mesangiocapillary glomerulonephritis in 7, anti-glomerular basement membrane glomerulonephritis in 2, and 4 were idiopathic. In 10 patients 50%-79% of glomeruli were affected by crescentic changes (group 1) and in the remaining 20, 80% or more (group 2). The crescents were cellular, fibrocellular or fibrous, and the degree of sclerosis was assessed. Patients in both groups were treated with plasma exchange, corticosteroids, anticoagulants, cyclophosphamide and azathioprine in different combinations. On follow-up, 3 patients were dead, 1 was lost to follow-up, 12 were on dialysis/transplant programmes, 4 had a GFR of less than 30 and 10 a GFR of more than 30 ml/min per 1.73 m2. In our experience, 50% progressed to end-stage renal failure. The interval between disease onset and start of treatment was a prognostic factor for outcome. Fibrous crescents were associated with a worse outcome than fibrocellular crescents (P less than 0.05). Outcome was not, however, related to the percentage of glomeruli affected (P greater than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

  9. [Glomerulonephritis in diabetics].

    PubMed

    Mágori, A; Sonkodi, S; Lászik, Z; Mohácsi, G

    1989-10-01

    Diagnosis of glomerulonephritis (GN) is rare among diabetics and few data relevant to this issue can be found in literature. In Institute of Pathology of "Szent-Györgyi Albert" University of Medicine the presence of GN was found in cases during the examination of renal biopsy material of 36 diabetics. All patients have suffered from diabetes mellitus of 2nd type and of less than 10 year existence, requiring no insulin treatment. In 2 cases diffuse diabetic glomerulosclerosis associated with GN. It is emphasized that kidney biopsy and its complex--light and electronmicroscopic and immunhistological--examination are essential to the diagnosis of GN of diabetics.

  10. Hypertension in Chronic Glomerulonephritis

    PubMed Central

    2015-01-01

    Chronic glomerulonephritis (GN), which includes focal segmental glomerulosclerosis and proliferative forms of GN such as IgA nephropathy, increases the risk of hypertension. Hypertension in chronic GN is primarily volume dependent, and this increase in blood volume is not related to the deterioration of renal function. Patients with chronic GN become salt sensitive as renal damage including arteriolosclerosis progresses and the consequent renal ischemia causes the stimulation of the intrarenal renin-angiotensin-aldosterone system(RAAS). Overactivity of the sympathetic nervous system also contributes to hypertension in chronic GN. According to the KDIGO guideline, the available evidence indicates that the target BP should be ≤140mmHg systolic and ≤90mmHg diastolic in chronic kidney disease patients without albuminuria. In most patients with an albumin excretion rate of ≥30mg/24 h (i.e., those with both micro-and macroalbuminuria), a lower target of ≤130mmHg systolic and ≤80mmHg diastolic is suggested. The use of agents that block the RAAS system is recommended or suggested in all patients with an albumin excretion rate of ≥30mg/ 24 h. The combination of a RAAS blockade with a calcium channel blocker and a diuretic may be effective in attaining the target BP, and in reducing the amount of urinary protein excretion in patients with chronic GN. PMID:26848302

  11. Membranous glomerulonephritis and Landry-Guillain-Barre syndrome.

    PubMed

    Murphy, B F; Gonzales, M F; Ebeling, P; Fairley, K F; Kincaid-Smith, P

    1986-10-01

    Two cases of idiopathic membranous glomerulonephritis associated with acute inflammatory demyelinating polyradiculoneuropathy (Landry-Guillian-Barre syndrome) are described. In both of the patients, the onset of the nephrotic syndrome coincided with the development of severe ascending sensorimotor neuropathy. Although this association has previously been reported in four other isolated cases, it is not generally recognized by nephrologists and may be of significance in the future understanding of the immunopathogenesis of both diseases.

  12. An unusual case of Plasmodium vivax malaria monoinfection associated with crescentic glomerulonephritis: a need for vigilance.

    PubMed

    Patel, Mohan P; Kute, Vivek B; Gumber, Manoj R; Gera, Dinesh N; Shah, Pankaj R; Patel, Himanshu V; Trivedi, Hargovind L; Vanikar, Aruna V

    2013-01-01

    Plasmodium vivax infection is increasingly a major public health burden and the second most frequent human malaria. Higher levels of clinical severity and chloroquine resistance are major factors responsible for such increases. Malarial glomerular injury is uncommon and mainly observed in Plasmodium malariae-infected patients. Occasionally, transient immune complex-mediated glomerulonephritis is associated with Plasmodium falciparum infection. Coexistent crescentic glomerulonephritis and vivax malaria have not previously been reported. We report a fatal case of P. vivax malaria, who presented with acute renal failure. P. vivax monoinfection status was diagnosed with peripheral blood smear and rapid antigen test. Further evaluation for renal failure related to systemic illness and immunological markers were inconclusive. He was treated with antimalarial drugs, hemodialysis, and supportive therapy. Renal biopsy performed for nonrecovering renal failure reveled crescentic glomerulonephritis. This case highlights the need to thoroughly search for malaria-associated crescentic glomerulonephritis using renal biopsy after nonrecovering renal failure.

  13. Haematuria on the Spanish Registry of Glomerulonephritis

    PubMed Central

    Yuste, Claudia; Rivera, Francisco; Moreno, Juan Antonio; López-Gómez, Juan Manuel

    2016-01-01

    Recent studies suggest a pathogenic role for glomerular haematuria among renal function. However, there is no data on the prevalence of haematuria from a large renal biopsy registry. We analysed the prevalence of gross (GH) and microscopic (mH) haematuria in 19,895 patients that underwent native renal biopsies from the Spanish Registry of Glomerulonephritis. Haematuria’s overall incidence was 63% (GH 8.6% and mH 55.1%), being more frequent in males (64.7% vs. 62.4%). GH was more prevalent in patients <18 years (21.3% vs. 7.7%). The commonest clinical presentation associated with GH was acute kidney injury (31.5%) and IgA Nephropathy (IgAN) (33.6%) was the most frequent histological finding. GH patients showed a significantly (p < 0.05) lower eGFR and proteinuria levels as compared with patients with mH and without haematuria. Moreover, mH was more prevalent in adults (56.3%). Nephrotic syndrome was the commonest clinical presentation in mH patients (32.2%) and IgAN (18.5%) the most frequent histological finding. In conclusion, haematuria, is a frequent urinalysis finding in patients underwent native renal biopsy. The most frequent histological finding in both GH and mH is IgAN. Whereas, GH is more frequent in young males with acute kidney injury, mH is commoner among adults with nephrotic syndrome. PMID:26818712

  14. Haematuria on the Spanish Registry of Glomerulonephritis.

    PubMed

    Yuste, Claudia; Rivera, Francisco; Moreno, Juan Antonio; López-Gómez, Juan Manuel

    2016-01-28

    Recent studies suggest a pathogenic role for glomerular haematuria among renal function. However, there is no data on the prevalence of haematuria from a large renal biopsy registry. We analysed the prevalence of gross (GH) and microscopic (mH) haematuria in 19,895 patients that underwent native renal biopsies from the Spanish Registry of Glomerulonephritis. Haematuria's overall incidence was 63% (GH 8.6% and mH 55.1%), being more frequent in males (64.7% vs. 62.4%). GH was more prevalent in patients <18 years (21.3% vs. 7.7%). The commonest clinical presentation associated with GH was acute kidney injury (31.5%) and IgA Nephropathy (IgAN) (33.6%) was the most frequent histological finding. GH patients showed a significantly (p < 0.05) lower eGFR and proteinuria levels as compared with patients with mH and without haematuria. Moreover, mH was more prevalent in adults (56.3%). Nephrotic syndrome was the commonest clinical presentation in mH patients (32.2%) and IgAN (18.5%) the most frequent histological finding. In conclusion, haematuria, is a frequent urinalysis finding in patients underwent native renal biopsy. The most frequent histological finding in both GH and mH is IgAN. Whereas, GH is more frequent in young males with acute kidney injury, mH is commoner among adults with nephrotic syndrome.

  15. Systemic lupus erythematosus with membranous glomerulonephritis and transverse myelitis associated with anabolic steroid use.

    PubMed

    Radis, C D; Callis, K P

    1997-10-01

    This report describes a 29-year-old bodybuilder taking anabolic steroids who presented with urinary retention, arthralgias, and peripheral edema, subsequently developed acute lower-extremity paralysis, and was diagnosed as having transverse myelitis and membranous glomerulonephritis secondary to systemic lupus erythematosus (SLE). The association of anabolic steroid use and hyperprolactinemia, and their possible link to the development of SLE, are reviewed.

  16. Glomerulonephritis

    MedlinePlus

    ... due to excess protein in the urine) Swelling (edema) of the face, eyes, ankles, feet, legs, or ... overload, including abnormal heart and lung sounds Swelling ( edema ) Imaging tests that may be done include: Abdominal ...

  17. Implications of Antiphospholipid and Antineutrophilic Cytoplasmic Antibodies in the Context of Postinfectious Glomerulonephritis

    PubMed Central

    Leifer, Daniel

    2017-01-01

    While antineutrophil cytoplasmic antibody (ANCA) positivity has been documented in some patients with postinfectious glomerulonephritis (PIGN) and is associated with more severe disease, antiphospholipid antibodies (APA) are not known to be a common occurrence. We describe a child with severe acute kidney injury who was noted to have prolonged positivity of both ANCA and APA; a renal biopsy showed noncrescentic immune complex mediated glomerulonephritis with subepithelial deposits compatible with PIGN. He recovered without maintenance immunosuppressive therapy and at last follow-up had normal renal function. We discuss the cooccurrence and implications of ANCA and APA in children with PIGN. PMID:28255306

  18. Fibrillary glomerulonephritis in Castleman's disease.

    PubMed

    Miadonna, A; Salmaso, C; Palazzi, P; Elli, A; Braidotti, P; Lambertenghi Deliliers, G

    1998-01-01

    Castleman's disease is an uncommon lymph node disorder which can be associated with renal disease. In this report we describe a patient with fever, weight loss, anorexia, increase in inflammatory proteins, anemia and nephrotic syndrome. Castleman's disease, plasma cell type, was diagnosed by histologic analysis after surgical excision of a pelvic lymph node. The disease was considered localized, since further investigations did not show any other pathologic mass. After resection of the pelvic lymphoid mass, clinical remission of systemic symptoms and laboratory abnormalities was observed, with the exception of the nephrotic syndrome. Renal biopsy was performed and showed a pattern compatible with fibrillary glomerulonephritis. Progressive decline in renal function was observed, despite immunosuppressive therapy.

  19. Poststreptococcal glomerulonephritis with pulmonary edema presenting as respiratory distress.

    PubMed

    Chiu, Chih-Yung; Huang, Yhu-Chering; Wong, Kin-Sun; Hsia, Shao-Hsuan; Lin, Chi-Jen; Lin, Tzou-Yien

    2004-11-01

    Acute poststreptococcal glomerulonephritis(PSGN) is characterized by an abrupt onset of edema,hypertension, and hematuria. Although the association of pulmonary edema with acute glomerulonephritis has been established, it is uncommon for children with PSGN to present with respiratory distress due to pulmonary edema. We encountered six such patients, aged 6-10 years, during a 10-month period. The demographic data, clinical manifestations, laboratory data, radiographic pictures, and clinical courses were collected. All patients presented to the primary pediatricians with dyspnea and alveolar infiltrates with bilateral pleural effusions on plain chest radiographs that were misinterpreted as pneumonia initially. The diagnosis of PSGN was de-layed until the awareness of the presence of pulmonary edema complicating PSGN. Subsequent urinalysis and blood pressure measurement all showed microscopic hematuria and hypertension. Elevated serum antistreptolysin 0 titers and depressed serum complement C3 levels confirmed the diagnosis of PSGN. Two patients progressed to respiratory failure because of a delayed diagnosis of PSGN. All patients recovered without sequelae following appropriate diuresis and antihypertensive therapy. We conclude that in preschool and school-age children who present with dyspneic respirations and a chest radiograph showing radiographic features of pulmonary edema, proper evaluation including blood pressure recording and urinalysis should be performed immediately. Prompt diagnosis and early therapy of PSGNmay avoid mortality and unnecessary therapeutic intervention.

  20. Multi-faceted AGN

    NASA Astrophysics Data System (ADS)

    Farrar, Glennys R.; Chen, Yanping; Dai, Yuxiao; Zaw, Ingyin

    2016-08-01

    An interesting question is how frequently an object is an AGN by multiple different criteria — e.g., is simultaneously a narrow-line optical AGN and an X-ray or radio AGN, possibly as a function of luminosities in the various wavebands and perhaps host galaxy type. Answering such questions quantitatively has been difficult up to now because of the lack of a complete, uniformly selected optical AGN catalog. Here we report first results of such an analysis, using the new, all-sky catalog of uniformly selected optical AGNs from Zaw, Chen and Farrar (2016), the Swift-BAT 70-month catalog of X-ray AGN (Baumgartner et al., 2013), and the van Velzen et al. (2012) catalog of radio AGN.

  1. Signatures of AGN feedback

    NASA Astrophysics Data System (ADS)

    Wylezalek, D.; Zakamska, N.

    2016-06-01

    Feedback from active galactic nuclei (AGN) is widely considered to be the main driver in regulating the growth of massive galaxies. It operates by either heating or driving the gas that would otherwise be available for star formation out of the galaxy, preventing further increase in stellar mass. Observational proof for this scenario has, however, been hard to come by. We have assembled a large sample of 133 radio-quiet type-2 and red AGN at 0.1AGN-ionized gas, the stellar masses of the host galaxies and their star formation rates. We then investigate the relationships between AGN luminosities, specific star formation rates (sSFR) and outflow strengths W_{90} - the 90% velocity width of the [OIII]λ5007Å line power and a proxy for the AGN-driven outflow speed. Outflow strength W_{90} is independent of sSFR for AGN selected based on their mid-IR luminosity. This is in agreement with previous work that demonstrates that star formation is not sufficient to produce the observed ionized gas outflows which have to be powered by AGN activity. More importantly, we find a negative correlation between W_{90} and sSFR in the AGN hosts with the highest star formation rates, i.e., with the highest gas content. This relationship implies that AGN with strong outflow signatures are hosted in galaxies that are more `quenched' considering their stellar mass than galaxies with weaker outflow signatures. This correlation is only seen in AGN host galaxies with SFR >100 M_{⊙} yr^{-1} where presumably the coupling of the AGN-driven wind to the gas is strongest. This observation is consistent with the AGN having a net suppression, or `negative' impact, through feedback on the galaxies' star formation history.

  2. A Molecular Signature of Proteinuria in Glomerulonephritis

    PubMed Central

    Reich, Heather N.; Tritchler, David; Cattran, Daniel C.; Eichinger, Felix; Boucherot, Anissa; Henger, Anna; Berthier, Celine C.; Nair, Viji; Cohen, Clemens D.

    2010-01-01

    Proteinuria is the most important predictor of outcome in glomerulonephritis and experimental data suggest that the tubular cell response to proteinuria is an important determinant of progressive fibrosis in the kidney. However, it is unclear whether proteinuria is a marker of disease severity or has a direct effect on tubular cells in the kidneys of patients with glomerulonephritis. Accordingly we studied an in vitro model of proteinuria, and identified 231 “albumin-regulated genes” differentially expressed by primary human kidney tubular epithelial cells exposed to albumin. We translated these findings to human disease by studying mRNA levels of these genes in the tubulo-interstitial compartment of kidney biopsies from patients with IgA nephropathy using microarrays. Biopsies from patients with IgAN (n = 25) could be distinguished from those of control subjects (n = 6) based solely upon the expression of these 231 “albumin-regulated genes.” The expression of an 11-transcript subset related to the degree of proteinuria, and this 11-mRNA subset was also sufficient to distinguish biopsies of subjects with IgAN from control biopsies. We tested if these findings could be extrapolated to other proteinuric diseases beyond IgAN and found that all forms of primary glomerulonephritis (n = 33) can be distinguished from controls (n = 21) based solely on the expression levels of these 11 genes derived from our in vitro proteinuria model. Pathway analysis suggests common regulatory elements shared by these 11 transcripts. In conclusion, we have identified an albumin-regulated 11-gene signature shared between all forms of primary glomerulonephritis. Our findings support the hypothesis that albuminuria may directly promote injury in the tubulo-interstitial compartment of the kidney in patients with glomerulonephritis. PMID:20976140

  3. Monoclonal gammopathy-associated proliferative glomerulonephritis.

    PubMed

    Sethi, Sanjeev; Rajkumar, S Vincent

    2013-11-01

    Monoclonal gammopathy is characterized by circulating monoclonal immunoglobulin owing to clonal proliferation of immunoglobulin-producing B lymphocytes or plasma cells. Clonal proliferation of B lymphocytes is seen in B-cell lymphoma/leukemia, and clonal plasma cell proliferation is seen in multiple myeloma and monoclonal gammopathy of undetermined significance. The monoclonal immunoglobulin in the setting of a B-cell or plasma cell disorder can cause a proliferative glomerulonephritis via 2 mechanisms: (1) glomerular deposition of the monoclonal immunoglobulin with activation of the classical pathway of complement (direct mechanism), resulting in an immunoglobulin-positive C3-positive glomerulonephritis, and (2) glomerular deposition of complement factors of the alternative and terminal pathway via inhibition of alternative pathway-regulating proteins by the monoclonal immunoglobulin (indirect mechanism), resulting in immunoglobulin-negative C3-positive glomerulonephritis (C3 glomerulopathy). Evaluation should include serum and urine electrophoresis and immunofixation as well as serum-free light-chain assay. If a monoclonal immunoglobulin is detected on these tests, bone marrow biopsy or imaging is needed to exclude more advanced plasma cell dyscrasia. Evaluation of alternative pathway of complement should be done in patients with Ig-negative C3-positive glomerulonephritis. If monoclonal gammopathy is due to an underlying malignant disease such as myeloma, lymphoma, or chronic lymphocytic leukemia, then specific treatment should be aimed at treating the malignant disease, with the goal of eradicating the clonal cells producing the immunoglobulin. In contrast, if monoclonal gammopathy is due to a monoclonal gammopathy of undetermined significance, treatment options include bortezomib, cyclophosphamide, and dexamethasone for a non-IgM monoclonal immunoglobulin and rituximab alone or in combination with cyclophosphamide and dexamethasone for an IgM monoclonal

  4. [Oligomeganephronic renal hypoplasia complicated by glomerulonephritis].

    PubMed

    Kan'shina, N F; Rykov, V A; Lakhno, P A

    1990-01-01

    Clinico-anatomical data of a rare condition congenital oligomeganephronic renal hypoplasia with a glomerulonephritis as a complication are available for a 13-year-old girl who died of chronic renal failure. Large aglomerular zones consisting of primitive canaliculi in a loose stroma were observed in kidneys that were decreased in size. The glomeruli were few in number, some of them of a large size (2-2.5-fold), firmly attached to the capsule, with pronounced extracapillary proliferation.

  5. Identifying Distant AGNs

    NASA Astrophysics Data System (ADS)

    Trouille, Laura; Barger, Amy; Tremonti, Christy

    2014-07-01

    The Baldwin, Phillips, and Terlevich emission-line ratio diagnostic ([OIII]/Hβ versus [NII]/Hα, hereafter BPT diagram) efficiently separates galaxies whose signal is dominated by star formation (BPT-SF) from those dominated by AGN activity (BPT-AGN). Yet the BPT diagram is limited to z<0.5, the redshift at which [NII]λ6584 leaves the optical spectral window. Using the Sloan Digital Sky Survey (SDSS), we construct a new diagnostic, or TBT diagram, that is based on rest-frame g-z color, [NeIII]λ3869, and [OII]λλ3726+3729 and can be used for galaxies out to z<1.4. The TBT diagram identifies 98.7% of the SDSS BPT-AGN as TBT-AGN and 97% of the SDSS BPT-SF as TBT-SF. Furthermore, it identifies 97% of the OPTX Chandra X-ray selected AGNs as TBT-AGN. This is in contrast to the BPT diagram, which misidentifies 20% of X-ray selected AGNs as BPT-SF.

  6. Signatures of AGN feedback

    NASA Astrophysics Data System (ADS)

    Wylezalek, Dominika; Zakamska, Nadia L.; MaNGA-GMOS Team

    2017-01-01

    Feedback from actively accreting SMBHs (Active Galactic Nuclei, AGN) is now widely considered to be the main driver in regulating the growth of massive galaxies. Observational proof for this scenario has, however, been hard to come by. Many attempts at finding a conclusive observational proof that AGN may be able to quench star formation and regulate the host galaxies' growth have shown that this problem is highly complex.I will present results from several projects that focus on understanding the power, reach and impact of feedback processes exerted by AGN. I will describe recent efforts in our group of relating feedback signatures to the specific star formation rate in their host galaxies, where our results are consistent with the AGN having a `negative' impact through feedback on the galaxies' star formation history (Wylezalek+2016a,b). Furthermore, I will show that powerful AGN-driven winds can be easily hidden and not be apparent in the integrated spectrum of the galaxy. This implies that large IFU surveys, such as the SDSS-IV MaNGA survey, might uncover many previously unknown AGN and outflows that are potentially very relevant for understanding the role of AGN in galaxy evolution (Wylezalek+2016c)!

  7. IgA glomerulonephritis. Mesangial IgA deposition without systemic signs (Berger's disease).

    PubMed

    Nagy, J; Brasch, H; Süle, T; Hámori, A; Deák, G; Ambrus, M

    1979-01-01

    Renal biopsy specimens from 204 patients with glomerulonephritis or nephrotic syndrome have been studied. In ten of the patients not suffering from acute poststreptococcal glomerulonephritis, systemic lupus erythematosus or Schönlein-Henoch syndrome, diffuse, selective mesangial IgA deposition was observed. Clinically, persistent microscopic haematuria, mild proteinuria and, except in one patient, normal renal function were found. Light microscopically the histological picture was dominated by a diffuse or focal increase in volume of the mesangial matrix, and mild mesangial cell proliferation. Exceptionally, there was also crescent formation. Immunofluorescence revealed large IgA, IgG and C3 deposits, as well as small IgM and fibrinogen deposits in the mesangial glomeruli. The authors' assumption that immunocomplexes containing a secretory component might be implicated in the pathomechanism of Berger's disease, could not be proved.

  8. Forty years abuse of baking soda, rhabdomyolysis, glomerulonephritis, hypertension leading to renal failure: a case report.

    PubMed

    Forslund, Terje; Koistinen, Arvo; Anttinen, Jorma; Wagner, Bodo; Miettinen, Marja

    2008-01-01

    We present a patient who had ingested sodium bicarbonate for treatment of alcoholic dyspepsia during forty years at increasing doses. During the last year he had used more than 50 grams daily. He presented with metabolic alkalosis, epileptic convulsions, subdural hematoma, hypertension and rhabdomyolysis with end stage renal failure, for which he had to be given regular intermittent hemodialysis treatment. Untreated hypertension and glomerulonephritis was probably present prior to all these acute incidents. Examination of the kidney biopsy revealed mesangial proliferative glomerulonephritis and arterial wall thickening causing nephrosclerosis together with interstitial calcinosis. The combination of all these pathologic changes might be responsible for the development of progressive chronic renal failure ending up with the need for continuous intermittent hemodialysis treatment.

  9. Forty Years Abuse of Baking Soda, Rhabdomyolysis, Glomerulonephritis, Hypertension Leading to Renal Failure: A Case Report

    PubMed Central

    Forslund, Terje; Koistinen, Arvo; Anttinen, Jorma; Wagner, Bodo; Miettinen, Marja

    2008-01-01

    We present a patient who had ingested sodium bicarbonate for treatment of alcoholic dyspepsia during forty years at increasing doses. During the last year he had used more than 50 grams daily. He presented with metabolic alkalosis, epileptic convulsions, subdural hematoma, hypertension and rhabdomyolysis with end stage renal failure, for which he had to be given regular intermittent hemodialysis treatment. Untreated hypertension and glomerulonephritis was probably present prior to all these acute incidents. Examination of the kidney biopsy revealed mesangial proliferative glomerulonephritis and arterial wall thickening causing nephrosclerosis together with interstitial calcinosis. The combination of all these pathologic changes might be responsible for the development of progressive chronic renal failure ending up with the need for continuous intermittent hemodialysis treatment. PMID:24179353

  10. Neutrinos from AGN

    NASA Technical Reports Server (NTRS)

    Kazanas, Demosthenes; White, Nicholas E. (Technical Monitor)

    2000-01-01

    The great penetrating power of neutrinos makes them ideal probe of astrophysical sites and conditions inaccessible to other forms of radiation. These are the centers of stars (collapsing or not) and the centers of Active Galactic Nuclei (AGN). It has been suggested that AGN presented a very promising source of high energy neutrinos, possibly detectable by underwater neutrino detectors. This paper reviews the evolution of ideas concerning the emission of neutrinos from AGN in view of the more recent developments in gamma-ray astronomy and their implications for the neutrino emission from these class of objects.

  11. Sjögren Syndrome-Related Membranous Glomerulonephritis Progressing to Membranoproliferative Glomerulonephritis

    PubMed Central

    Yabuuchi, Junko; Suwabe, Tatsuya; Ueno, Toshiharu; Hoshino, Junichi; Sekine, Akinari; Hayami, Noriko; Oguro, Masahiko; Kunisawa, Kyohei; Kawada, Masahiro; Yamanouchi, Masayuki; Sumida, Keiichi; Mizuno, Hiroki; Hasegawa, Eiko; Sawa, Naoki; Takaichi, Kenmei; Ohashi, Kenichi; Fujii, Takeshi; Ubara, Yoshifumi

    2016-01-01

    We report a case of glomerulopathy in a 36-year-old Japanese woman with primary Sjögren syndrome (pSS). The first renal biopsy suggested membranous glomerulonephritis. However, repeat biopsy was performed after 16 years because of increased proteinuria, revealing membranoproliferative glomerulonephritis with mesangial deposits, subendothelial deposits, and subepithelial deposits. Immunofluorescent studies showed predominant deposition of IgG2 and IgG4. This patient was positive for antinuclear antibody and anti-SS-A antibody. Sicca syndrome was confirmed by a positive Schirmer test and positive Rose Bengal test. Therefore, pSS-related glomerulopathy was considered to be the most likely diagnosis. PMID:27904866

  12. Optically-selected AGN

    NASA Astrophysics Data System (ADS)

    Richard, Gordon

    2016-08-01

    will discuss the selection and properties of optically-selected AGN as contrasted with other multi-wavelength investigations. While optical surveys are able to identify *more* AGNs than other wavelengths, this size comes with a bias towards brighter, unobscured sources. Although optical surveys are not ideal for probing obscured AGNs, I will discuss how they can guide our search for them. The bias towards unobscured sources in the optical is partially mitigated, however, by an increase in information content for the sources that *are* identified---in the form of physics probed by the combination of optical continuum, absorption, and emission. An example is the ability to estimate the mass of AGNs based on the optical/UV emission lines. I will discuss the range of mass (and accretion rate) probed by the optical in addition to serious biases in the black hole mass scaling relations that corrupt these estimates at high redshift.

  13. Post-infectious glomerulonephritis following infective endocarditis: Amenable to immunosuppression

    PubMed Central

    Mantan, M.; Sethi, G. R.; Batra, V. V.

    2013-01-01

    Glomerulonephritis develops in about 20% patients with infective endocarditis (IE), but is mostly asymptomatic. Heavy proteinuria or derangement of kidney functions is uncommon. We report here a child with IE and proliferative glomerulonephritis who manifested as significant proteinuria that recovered on treatment with immunosupressants. PMID:24049276

  14. Rapidly progressive glomerulonephritis after immunotherapy for cancer.

    PubMed

    Parker, M G; Atkins, M B; Ucci, A A; Levey, A S

    1995-04-01

    Cytokines have been used in experimental and standard protocols for immune enhancement for cancer. The combination of interleukin-2 and interferon-alpha 2 beta has been used in experimental protocols for metastatic renal cell carcinoma. A man who developed rapidly progressive renal failure after receiving this combination therapy is reported. A renal biopsy revealed a pauci-immune crescentic glomerulonephritis. Antineutrophil cytoplasmic antibodies and antiglomerular basement membrane antibodies were absent. The spectrum of renal disease and potentially related extrarenal manifestations associated with interleukin-2 and inteferon-alpha are reviewed. A pathogenesis of altered cell-mediated immunity, consistent with abnormalities in extrarenal organs after immune enhancement, is proposed.

  15. Correlation of disease activity in proliferative glomerulonephritis with glomerular spleen tyrosine kinase expression.

    PubMed

    McAdoo, Stephen P; Bhangal, Gurjeet; Page, Theresa; Cook, H Terence; Pusey, Charles D; Tam, Frederick W K

    2015-07-01

    Spleen tyrosine kinase (SYK) is an important component of the intracellular signaling pathway for various immunoreceptors. Inhibition of SYK has shown promise in preclinical models of autoimmune and glomerular disease. However, the description of SYK expression in human renal tissue, which would be desirable ahead of clinical studies, is lacking. Here we conducted immunohistochemical analysis for total and phosphorylated SYK in biopsy specimens from >120 patients with a spectrum of renal pathologies, including thin basement membrane lesion, minimal change disease, membranous nephropathy, IgA nephropathy, lupus nephritis, ANCA-associated glomerulonephritis, antiglomerular basement membrane disease, and acute tubular necrosis. We found significant SYK expression in proliferative glomerulonephritis and that glomerular expression levels correlated with presenting serum creatinine and histological features of disease activity that predict outcome in IgA nephropathy, lupus nephritis, ANCA-associated glomerulonephritis, and antiglomerular basement membrane disease. SYK was phosphorylated within pathological lesions, such as areas of extracapillary and endocapillary proliferation, and appeared to localize to both infiltrating leucocytes and to resident renal cells within diseased glomeruli. Thus SYK is associated with the pathogenesis of proliferative glomerulonephritides, suggesting that these conditions may respond to SYK inhibitor treatment.

  16. [Glomerulonephritis with IgA mesangial deposits].

    PubMed

    Pillebout, Evangéline; Nochy, Dominique

    2010-11-01

    IgA nephropathy is the primitive glomerulonephritis the most frequently encountered worldwide. In about one case out of three, it is responsible for the progression from progressive renal failure to end-stage renal failure. The pathophysiological mechanisms of this disease which is mediated by immune complexes remain unclear. The presentation, clinical progression and optical microscope aspect of the renal biopsy may widely vary, making any histological classification very difficult. Most therapeutic studies include the patients only on clinical criteria of severity. The only consensual management is that of patients with a nephropathy and mild glomerular lesions and a nephritic syndrome, or with an extracapillar glomerulonephritis and a rapidly progressive renal failure; corticoids are indicated in former cases while corticoids must be combined with immunosuppressive agents in the latter ones. Corticotherapy may be considered in patients with a proteinuria higher than 1g/day without renal failure. In any patient with primitive IgA nephropathy, the overall management used for chronic glomerulopathy must be initiated, including, in case of arterial hypertension or proteinuria, the renin-angiotensin system blockade.

  17. Polyarthritis and membranoproliferative glomerulonephritis as paraneoplastic manifestation of Hodgkin's lymphoma: A case report and literature review.

    PubMed

    Erlij, Daniel; Calderón, Beatriz; Rivera, Angela; Mella, Cristián; Valladares, Ximena; Roessler, Emilio; Rivera, María Teresa; Méndez, Gonzalo

    2016-01-01

    Paraneoplastic syndromes can be presented in multiple ways, which include endocrinological, hematologic, rheumatologic and nephrologic manifestations. While most of the publications described solid tumors as responsible for these manifestations, hematologic neoplasms are important cause to consider as part of the differential diagnosis. We report the case of a 46 year-old man with seronegative symmetric polyarthritis of large and small joints associated with membranoproliferative glomerulonephritis with deposits of immune complexes and acute impairment of renal function, as part of a paraneoplastic syndrome secondary of a classical Hodgkin lymphoma with bone marrow invasion, which reversed completely with chemotherapy treatment.

  18. The evolution of obscured AGN

    NASA Astrophysics Data System (ADS)

    Brightman, Murray

    2012-09-01

    We present results on the evolution of Compton thick AGN with redshift, and the nature of this obscuration, important for understanding the accretion history of the universe and for AGN unification schemes. We use lessons learned from spectral complexity of local AGN (Brightman & Nandra 2012) and up to date spectral models of heavily absorbed AGN, which take into account Compton scattering, self consistent Fe Ka modeling and the geometry of the circumnuclear material (Brightman & Nandra 2011), to optimise our identification of Compton thick AGN and understanding of the obscuring material. Results from the Chandra Deep Field South are presented (Brightman & Ueda, 2012), which show an increasing fraction of CTAGN with redshift and that most heavily obscured AGN are geometrically deeply buried in material, as well as new results from and extension of this study to AEGIS-XD and Chandra-COSMOS survey, which aim to fully characterise the dependence of heavy AGN obscuration on redshift and luminosity.

  19. Antiglomerular basement membrane antibody-mediated glomerulonephritis after intranasal cocaine use.

    PubMed

    Peces, R; Navascués, R A; Baltar, J; Seco, M; Alvarez, J

    1999-01-01

    We report a case of rapidly progressive glomerulonephritis due to antiglomerular basement membrane (anti-GBM) antibodies that progressed to end-stage renal disease in a 35-year-old man who used intranasal cocaine on an occasional basis. In contrast to many prior reports of acute renal failure occurring with cocaine-associated rhabdomyolysis, this patient did not have any evidence of acute muscle damage and myoglobin release. Circulating anti-GBM antibodies and renal biopsy with linear IgG and C3 deposits confirmed the diagnosis of anti-GBM disease. The possibility of anti-GBM must be considered in the differential diagnosis of acute renal failure in cocaine addicts. This unusual combination raises complex questions regarding the pathogenesis of this type of renal injury.

  20. Ionized Absorbers in AGN

    NASA Technical Reports Server (NTRS)

    Mathur, S.

    1999-01-01

    As a part of this program, we observed three AGN:PKS2251 + 113, PG0043 = 039 and PLH909. Two objects show signatures of absorbtion in their UV spectra. Based on our earlier modeling of X-ray warm absorbents, we expected to observe X-ray observation in these objects. The third, PLH909, is known to have soft excess in EINSTEIN data. Attachment: "Exploratory ASCA observation of broad absorption line quasi-stellar objects".

  1. An unusual case of IgA-dominant postinfectious glomerulonephritis: a case report and review of the literature.

    PubMed

    Wagrowska-Danilewicz, M; Danilewicz, M; Fisiak, I; Piskorska, J

    2016-06-01

    We report a case of IgA-dominant postinfectious glomerulonephritis in a 49-year-old man presenting with acute kidney injury, nephrotic range proteinuria and hematuria. He suffered from ischemic heart disease, cardiac insufficiency, mitral regurgitation, tricuspid insufficiency, septal aneurysm and hypertension. Renal biopsy revealed segmental and focal endocapillary and mesangial hypercellularity, and thickening of the glomerular capillary wall. Immunofluorescence showed co-dominant strong coarse granular immunostaining of IgA, IgG and C3 mainly along the glomerular capillary wall. On electron microscopy some large subepithelial hump-shaped deposits were present. In summary, this case demonstrates the presence of a broad spectrum of glomerular histological findings in postinfectious glomerulonephritis.

  2. Spectrum and outcome of primary glomerulonephritis.

    PubMed

    Al Wakeel, Jamal S; Mitwalli, Ahmed H; Tarif, Nauman; Alam, Awatif A; Hammad, Durdana; Abu-Aisha, Hassan; Memon, Nawaz; Sulimani, Fathia; Askar, Akram; Qudsi, Abdo

    2004-01-01

    Glomerulonephritis (GN) is a major cause of chronic renal failure (CRF). To evaluate the trends and outcome with modern improved treatment strategies, we retrospectively reviewed the clinical records of 120 patients with biopsy proven primary GN at our center from January 1990 to June 2001. All the biopsy specimens were subjected to light, electron and immunofluorescent microscopy. The recorded clinical parameters included the presenting symptoms, blood pressure readings, complete blood count, urinalysis, 24-hr urinary protein excretion, creatinine clearance besides rendered therapy and the outcome. Focal segmental glomerulosclerosis was the most common GN and accounted for 56 (47.6%) cases. The frequency of other GN cases in our study included IgA GN in 21 (17.5%) patients, membranous GN in 20 (16.7%), minimal change disease (MCD) in 13 (10.8%), membranoproliferative GN in 4 (3.3%), post infection in 4 (3.3%) and rapidly progressive glomerulonephritis (RPGN) in 2 (1.7%). The type of nephropathy had great influence on outcome and response to therapy. The deterioration of patients with FSGS was the fastest of the glomerulopathies, and nine (16.1%) patients developed end-stage renal failure (ESRD). MCD and post infection GN had the best outcome. Corticosteroids alone along with supportive medication conferred good results in MCD, while combined therapies of mycophenolate mofetil (MMF) and/or cyclophosphamide with corticosteroids provided better outcomes in the rest of the GN. RPGN responded well to the cyclophosphamide and the patients did not develop ESRD. Hyperuricemia, high serum creatinine and hypertension predicted worse outcomes. The control of blood pressure and glucose, and treatment of hyperuricemia and hypoalbuminemia had salutary effect on the outcome. We conclude that due to the better delivered care the outcome of primary GN has improved over the years. However, FSGS is still the most frequently encountered primary GN and has the worst outcome. In the

  3. Starburst or AGN dominance in submm-luminous candidate AGN

    NASA Astrophysics Data System (ADS)

    Coppin, Kristen; Alexander, Dave; Aretxaga, Itziar; Blain, Andrew; Chapman, Scott; Clements, Dave; Dunlop, James; Dunne, Loretta; Dye, Simon; Farrah, Duncan; Hughes, David; Ivison, Rob; Kim, Sungeun; Menendez-Delmestre, Karin; Oliver, Sebastian; Page, Mat; Pope, Alexandra; Rowan-Robinson, Michael; Scott, Douglas; Smail, Ian; Swinbank, Mark; Vaccari, Mattia; van Kampen, Eelco

    2008-03-01

    It is widely believed that starbursts/ULIRGs and AGN activity are triggered by galaxy interactions and merging; and sub-mm selected galaxies (SMGs) seem to be simply high redshift ULIRGs, observed near the peak of activity. In this evolutionary picture every SMG would host an AGN, which would eventually grow a black hole strong enough to blow off all of the gas and dust leaving an optically luminous QSO. In order to probe this evolutionary sequence, a crucial sub-sample to focus on would be the 'missing link' sources, which demonstrate both strong starburst and AGN signatures and to determine if the starburst is the main power source even in SMGs when we have evidence that an AGN is present. The best way to determine if a dominant AGN is present is to look in the mid-IR for their signatures, since often even deep X-ray observations miss identifying the presence of AGN in heavily dust-obscured SMGs. We have selected a sample of SMGs which are good candidates for harboring powerful AGN on the basis of their IRAC colours (S8um/S4.5um>2). Once we confirm these SMGs are AGN-dominated, we can then perform an audit of the energy balance between star-formation and AGN within this special sub-population of SMGs where the BH has grown appreciably to begin heating the dust emission. The proposed observations with IRS will probe the physics of how SMGs evolve from a cold-dust starburst-dominated ULIRG to an AGN/QSO by measuring the level of the mid-IR continuum, PAH luminosity, and Si absorption in these intermediate `transitory' AGN/SMGs.

  4. The Changing Looks of AGN

    NASA Astrophysics Data System (ADS)

    LaMassa, S.

    2015-09-01

    According to the AGN unification model, the difference between Type 1 and Type 2 AGN is explained by the orientation of a circumnuclear obscuring torus to the observer's line of sight. Observations of seemingly anomalous sources challenge this theory. A handful of AGN have been discovered which have transitioned from Type 1, with strong, prominent broad-emission lines, to Type 1.8 or 1.9, with weak broad components to only H-alpha and/or H-beta, or vice versa. The rate of discovery of these objects has increased this past year thanks to the Sloan Digital Sky Survey BOSS and TDSS surveys which have repeated spectroscopic observations of AGN. While in some cases this transition can be explained by circumnuclear clouds eclipsing the broad line region, it seems clear that stochastic accretion is responsible for other changing-look AGN. In this talk, I will discuss the changing-look AGN discovered thus far and the implications these objects have for AGN unification and the intermittency of AGN activity.

  5. Obscured accretion from AGN surveys

    NASA Astrophysics Data System (ADS)

    Vignali, Cristian

    2014-07-01

    Recent models of super-massive black hole (SMBH) and host galaxy joint evolution predict the presence of a key phase where accretion, traced by obscured Active Galactic Nuclei (AGN) emission, is coupled with powerful star formation. Then feedback processes likely self-regulate the SMBH growth and quench the star-formation activity. AGN in this important evolutionary phase have been revealed in the last decade via surveys at different wavelengths. On the one hand, moderate-to-deep X-ray surveys have allowed a systematic search for heavily obscured AGN, up to very high redshifts (z~5). On the other hand, infrared/optical surveys have been invaluable in offering complementary methods to select obscured AGN also in cases where the nuclear X-ray emission below 10 keV is largely hidden to our view. In this review I will present my personal perspective of the field of obscured accretion from AGN surveys.

  6. ANCA positivity in a patient with infective endocarditis-associated glomerulonephritis: a diagnostic dilemma.

    PubMed

    Ghosh, Gopal Chandra; Sharma, Brijesh; Katageri, Bhimarey; Bhardwaj, Minakshi

    2014-09-01

    Glomerulonephritis (GN) is an immunological phenomenon in bacterial endocarditis. These may be pauci-immune/vasculitic GN, post-infective GN, and sub-endothelial membranoproliferative glomerulonephritis. Each type of glomerulonephritis usually occurs in isolation. We report a case of infective endocarditis with dual existence of pauci-immune/vasculitic GN and post infective type of GN at the same time.

  7. Arterial hypertension in chronic glomerulonephritis. An analysis of 310 cases.

    PubMed

    Danielsen, H; Kornerup, H J; Olsen, S; Posborg, V

    1983-06-01

    310 cases of glomerulonephritis classified morphologically according to the criteria of the WHO were analyzed retrospectively in order to determine the frequency of arterial hypertension. The overall prevalence of arterial hypertension was 61%. Hypertension was most frequent and severe in membranoproliferative and sclerotic glomerulonephritis, but often mild and transient in extracapillary glomerulonephritis. Hypertension usually developed during the early stages of the disease when kidney function was well preserved and in only 16% was hypertension first seen during the uremic stage. No correlation was found between hypertension and the presence of the nephrotic syndrome. During dialysis, hypertension was present in 78%; in 90% of these patients hypertension was "controllable" and in 10% it was "uncontrollable".

  8. Membranoproliferative glomerulonephritis associated with autoimmune diseases.

    PubMed

    Zand, Ladan; Fervenza, Fernando C; Nasr, Samih H; Sethi, Sanjeev

    2014-04-01

    Membranoproliferative glomerulonephritis (MPGN) has been classified based on its pathogenesis into immune complex-mediated and complement-mediated MPGN. The immune complex-mediated type is secondary to chronic infections, autoimmune diseases or monoclonal gammopathy. There is a paucity of data on MPGN associated with autoimmune diseases. We reviewed the Mayo Clinic database over a 10-year period and identified 12 patients with MPGN associated with autoimmune diseases, after exclusion of systemic lupus erythematosus. The autoimmune diseases included rheumatoid arthritis, primary Sjögren's syndrome, undifferentiated connective tissue disease, primary sclerosing cholangitis and Graves' disease. Nine of the 12 patients were female, and the mean age was 57.9 years. C4 levels were decreased in nine of 12 patients tested. The serum creatinine at time of renal biopsy was 2.2 ± 1.0 mg/dl and the urinary protein was 2,850 ± 3,543 mg/24 h. Three patients required dialysis at the time of renal biopsy. Renal biopsy showed an MPGN in all cases, with features of cryoglobulins in six cases; immunoglobulin (Ig)M was the dominant Ig, and both subendothelial and mesangial electron dense deposits were noted. Median follow-up was 10.9 months. Serum creatinine and proteinuria improved to 1.6 ± 0.8 mg/dl and 428 ± 677 mg/24 h, respectively, except in 3 patients with end-stage renal disease. In summary, this study describes the clinical features, renal biopsy findings, laboratory evaluation, treatment and prognosis of MPGN associated with autoimmune diseases.

  9. Anti-neutrophil cytoplasmic autoantibody-associated glomerulonephritis and vasculitis.

    PubMed Central

    Jennette, J. C.; Wilkman, A. S.; Falk, R. J.

    1989-01-01

    Anti-neutrophil cytoplasmic autoantibodies (ANCA) react with constituents of neutrophil primary granules and monocyte lysosomes. Indirect immunofluorescence microscopy using alcohol-fixed neutrophils demonstrates two ANCA types: one causing cytoplasmic staining (C-ANCA), and a second causing artifactual perinuclear staining (P-ANCA) that frequently has specificity for myeloperoxidase. Using indirect immunofluorescence microscopy (IIFM) and enzyme immunoassays (EIA), sera from over 300 patients with renal disease, with and without systemic vasculitis, were analyzed. Of 76 patients with pauci-immune glomerulonephritis with crescents or necrosis, 87% had ANCA by IIFM (38% of C-ANCA type, 49% of P-ANCA type), and 78% had ANCA by EIA. Of 55 patients with nonlupus immune complex-mediated glomerulonephritis, only 11% had ANCA by IIFM and 5% had ANCA by EIA. Of 24 patients with anti-GBM antibody-mediated glomerulonephritis, none had ANCA. Renal and extrarenal lesions were studied in 81 patients with ANCA-associated glomerulonephritis. These patients formed a pathologic continuum ranging from renal-limited to widespread systemic vascular injury, including patients with primary crescentic glomerulonephritis, Wegener's granulomatosis, and polyarteritis nodosa. In ANCA-positive patients the frequency of C-ANCA and P-ANCA correlated with disease distribution. P-ANCA was most frequent with renal-limited disease and C-ANCA was most frequent when there was lung and sinus involvement. It is proposed that ANCA are not only useful diagnostic markers, but may also be directly involved in a novel pathogenetic mechanism that is a frequent cause of crescentic glomerulonephritis and systemic necrotizing vasculitis. Images Figure 1 Figure 4 Figure 5 Figure 6 Figure 7 PMID:2683800

  10. Classifying murine glomerulonephritis using optical coherence tomography and optical coherence elastography.

    PubMed

    Liu, Chih-Hao; Du, Yong; Singh, Manmohan; Wu, Chen; Han, Zhaolong; Li, Jiasong; Chang, Anthony; Mohan, Chandra; Larin, Kirill V

    2016-08-01

    Acute glomerulonephritis caused by antiglomerular basement membrane marked by high mortality. The primary reason for this is delayed diagnosis via blood examination, urine analysis, tissue biopsy, or ultrasound and X-ray computed tomography imaging. Blood, urine, and tissue-based diagnoses can be time consuming, while ultrasound and CT imaging have relatively low spatial resolution, with reduced sensitivity. Optical coherence tomography is a noninvasive and high-resolution imaging technique that provides superior spatial resolution (micrometer scale) as compared to ultrasound and CT. Changes in tissue properties can be detected based on the optical metrics analyzed from the OCT signals, such as optical attenuation and speckle variance. Furthermore, OCT does not rely on ionizing radiation as with CT imaging. In addition to structural changes, the elasticity of the kidney can significantly change due to nephritis. In this work, OCT has been utilized to quantify the difference in tissue properties between healthy and nephritic murine kidneys. Although OCT imaging could identify the diseased tissue, its classification accuracy is clinically inadequate. By combining optical metrics with elasticity, the classification accuracy improves from 76% to 95%. These results show that OCT combined with OCE can be a powerful tool for identifying and classifying nephritis. Therefore, the OCT/OCE method could potentially be used as a minimally invasive tool for longitudinal studies during the progression and therapy of glomerulonephritis as well as complement and, perhaps, substitute highly invasive tissue biopsies. Elastic-wave propagation in mouse healthy and nephritic kidneys.

  11. Granulomatosis with Polyangiitis Presenting as Pauci-Immune Crescentic Glomerulonephritis in Pregnancy

    PubMed Central

    Kunjal, Ryan; Makary, Raafat; Poenariu, Andreea

    2016-01-01

    Antineutrophil cytoplasmic antibody (ANCA) associated vasculitis rarely affects females of reproductive age. A 28-year-old African American woman presented at 8 weeks of gestation with intractable vomiting attributed to hyperemesis gravidarum. She was found to have acute kidney injury that was unresponsive to vigorous fluid resuscitation and urine sediment examination was suggestive of an underlying glomerulonephritis. Serum c-ANCA and PR3 were elevated and there was no peripheral eosinophilia. During her course she also developed one episode of small volume hemoptysis with right upper lobe infiltrates on CT Chest. There were no cutaneous manifestations of vasculitis or upper respiratory symptoms. Renal biopsy revealed a pauci-immune crescentic glomerulonephritis (PICGN). The diagnosis was consistent with granulomatosis with polyangiitis (GPA). Management initially comprised teratogen sparing agents; steroids, intravenous immunoglobulin; and plasma exchange. The response was suboptimal and she became dependent on daily renal replacement therapy. Ultimately the pregnancy was terminated allowing for traditional treatment approaches with dramatic effect. This is the first case of GPA presenting as PICGN in pregnancy and highlights the challenges of its management. PMID:27293925

  12. Pediatric case of crescentic post-streptococcal glomerulonephritis with myeloperoxidase anti-neutrophil cytoplasmic antibody.

    PubMed

    Kanai, Hiroaki; Sawanobori, Emi; Koizumi, Keiichi; Ohashi, Ryuji; Higashida, Kosuke

    2015-04-01

    Post-streptococcal glomerulonephritis (PSGN) generally has a good renal prognosis, and immunosuppressive therapies are not needed. However, a few patients present with severe acute kidney injury and extensive crescent formations. The etiology of such patients is not well known, and involvement of anti-neutrophil cytoplasmic antibodies is rarely reported. A 9-year-old girl with rapidly progressive nephritic syndrome was diagnosed with PSGN. A biopsy showed diffuse crescentic glomerulonephritis with immunoglobulin G and C3 deposits; moreover, humps were observed on electron microscopy. After she was administered methylprednisolone pulse therapy and intravenous cyclophosphamide, followed by prednisolone and azathioprine therapy, her urinary abnormalities improved and renal function normalized. However, the myeloperoxidase anti-neutrophil cytoplasmic antibody (MPO-ANCA) titers gradually increased. We speculated that PSGN may be augmented by increased MPO-ANCA levels. Therefore, the patient is currently being treated with losartan, enalapril, azathioprine, and prednisolone. Although the MPO-ANCA titer remains high, urinary findings show mild proteinuria and her renal function has been norma for 18 months since onset. A progressive clinical course and severe histological findings may indicate the involvement of ANCA in deterioration of condition in patients with PSGN. Furthermore, in such cases immunosuppressive therapies should be considered even in pediatric PSGN.

  13. Starburst or AGN Dominance in Submillimetre-Luminous Candidate AGN?

    NASA Astrophysics Data System (ADS)

    Coppin, Kristen; Pope, Alexandra; Menéndez-Delmestre, Karín; Alexander, David M.; Dunlop, James

    2010-06-01

    It is widely believed that ultraluminous infrared (IR) galaxies and active galactic nuclei (AGN) activity are triggered by galaxy interactions and merging, with the peak of activity occurring at z~2, where submillimetre galaxies are thousands of times more numerous than local ULIRGs. In this evolutionary picture, submillimetre galaxies (SMGs) would host an AGN, which would eventually grow a black hole (BH) strong enough to blow off all of the gas and dust leaving an optically luminous QSO. To probe this evolutionary sequence we have focussed on the `missing link' sources, which demonstrate both strong starburst (SB) and AGN signatures, in order to determine if the SB is the main power source even in SMGs when we have evidence that an AGN is present from their IRAC colours. The best way to determine if a dominant AGN is present is to look for their signatures in the mid-infrared with the Spitzer IRS, since often even deep X-ray observations miss identifying the presence of AGN in heavily dust-obscured SMGs. We present the results of our audit of the energy balance between star-formation and AGN within this special sub-population of SMGs-where the BH has grown appreciably to begin heating the dust emission.

  14. Spectrum of glomerular diseases causing acute kidney injury; 25 years experience from a single center

    PubMed Central

    Naqvi, Rubina; Mubarak, Muhammed; Ahmed, Ejaz; Akhtar, Fazal; Bhatti, Sajid; Naqvi, Anwar; Rizvi, Adib

    2015-01-01

    Introduction: Acute kidney injury (AKI) is common in nephro-urological practice. Its incidence, prevalence and etiology vary widely, mainly due to variations in the definitions of AKI. Objectives: We aim to report the spectrum of glomerular diseases presenting as AKI at a kidney referral center in Pakistan. Patients and Methods: An observational cohort of patients identified as having AKI which was defined according to RIFLE criteria, with normal size, non-obstructed kidneys on ultrasonography, along with active urine sediment, edema and new onset hypertension. Results: From 1990 to 2014, 236 cases of AKI secondary to acute glomerulonephritis (AGN) registered at this institution. Mean age of patients was 27.94± 12.79 years and M:F ratio was 0.77:1. Thirty percent patients revealed crescents on renal biopsy. AGN without crescents was seen in 33.05% of cases. Postinfectious GN was found in 14.4%, lupus nephritis in 8.5% and mesangiocapillary GN in 3.4% cases. Renal replacement therapy (RRT) required in 75.84% patients. Pulse steroids were given in 45.33% cases followed by oral steroids. Pulse cyclophoshphamide was given in 23.7% cases and plasmapheresis was used in 3.38% cases. Complete recovery was seen in 44%, while 11.44% died during acute phase of illness. About 19.49 % developed chronic kidney disease (CKD) and 25.84% were lost to long- term follow-up. Conclusion: Although glomerular diseases contribute only 4.19 % of total AKI at this center, morbidity associated with illness and its treatment is more marked than other AKI groups. Another notable factor is late referral of these patients to specialized centers resulting in undesirable outcome. PMID:26693497

  15. Predictors of outcome in idiopathic rapidly progressive glomerulonephritis (IRPGN)

    PubMed Central

    Alexopoulos, Efstathios; Gionanlis, Lazaros; Papayianni, Ekaterini; Kokolina, Elizabeth; Leontsini, Maria; Memmos, Dimitrios

    2006-01-01

    Background Small vessel vasculitides are known to follow a devastating course towards end-stage renal disease, unless treated with immunosuppressive regiments. We investigated the value of clinical, histological and immunohistochemical parameters as predictors of outcome at diagnosis in patients with pauci immune necrotizing glomerulonephritis. Methods In 34 patients the percentage and evolution stage of crescents, the presence of glomerular necrosis, the degree or severity of arteriosclerosis, as well as the extent of tubulointerstitial infiltration, interstial fibrosis and tubular atrophy were assessed. Monoclonal antibodies were used to identify infiltrating macrophages, α-SMA(+) and PCNA(+) cells, the expression of integrins α3β1 and LFA-1β, the adhesion molecule ICAM-1, the growth factor TGF-β1 and the terminal complement component C5b-9. Results 24 pts (70.6%) showed a complete or partial response to the treatment. The follow-up period was 20 ± 22 months. At multivariate analysis, serum CRP (p = 0.024), the intensity of tubular expression of C5b-9 (p < 0.0001) as well as the extent of glomerular and tubular expression of α3β1 integrin (p = 0.001 and 0.008 respectively) independently predicted the response to treatment. The response rate was better in ANCA(+) pts (p = 0.008). The extent of interstitial infiltrate (p < 0.0001), the severity of tubulointerstitial fibrosis (p < 0.0001) and the severity of tubular TGF-β1 expression (p < 0.0001) were independent predictors of long term outcome of renal function. Conclusion Patients with ANCA-associated renal vasculitis seem to respond better to the treatment. Acute phase reactants, such as CRP, implying a more intense parenchymal inflammatory reaction, as well as the intensity of the de novo expression of C5b-9 and the glomerular and tubular expression of α3β1 integrin predict the response to therapy. The severity of TIN lesions and of the tubulo-interstitial TGF-β1 and C5b-9 expression predict an

  16. Accretion Timescales from Kepler AGN

    NASA Astrophysics Data System (ADS)

    Kasliwal, Vishal P.; Vogeley, Michael S.; Richards, Gordon T.

    2015-01-01

    We constrain AGN accretion disk variability mechanisms using the optical light curves of AGN observed by Kepler. AGN optical fluxes are known to exhibit stochastic variations on timescales of hours, days, months and years. The excellent sampling properties of the original Kepler mission - high S/N ratio (105), short sampling interval (30 minutes), and long sampling duration (~ 3.5 years) - allow for a detailed examination of the differences between the variability processes present in various sub-types of AGN such as Type I and II Seyferts, QSOs, and Blazars. We model the flux data using the Auto-Regressive Moving Average (ARMA) representation from the field of time series analysis. We use the Kalman filter to determine optimal mode parameters and use the Akaike Information Criteria (AIC) to select the optimal model. We find that optical light curves from Kepler AGN cannot be fit by low order statistical models such as the popular AR(1) process or damped random walk. Kepler light curves exhibit complicated power spectra and are better modeled by higher order ARMA processes. We find that Kepler AGN typically exhibit power spectra that change from a bending power law (PSD ~ 1/fa) to a flat power spectrum on timescales in the range of ~ 5 - 100 days consistent with the orbital and thermal timescales of a typical 107 solar mass black hole.

  17. Probing AGN Accretion Physics through AGN Variability: Insights from Kepler

    NASA Astrophysics Data System (ADS)

    Kasliwal, Vishal Pramod

    Active Galactic Nuclei (AGN) exhibit large luminosity variations over the entire electromagnetic spectrum on timescales ranging from hours to years. The variations in luminosity are devoid of any periodic character and appear stochastic. While complex correlations exist between the variability observed in different parts of the electromagnetic spectrum, no frequency band appears to be completely dominant, suggesting that the physical processes producing the variability are exceedingly rich and complex. In the absence of a clear theoretical explanation of the variability, phenomenological models are used to study AGN variability. The stochastic behavior of AGN variability makes formulating such models difficult and connecting them to the underlying physics exceedingly hard. We study AGN light curves serendipitously observed by the NASA Kepler planet-finding mission. Compared to previous ground-based observations, Kepler offers higher precision and a smaller sampling interval resulting in potentially higher quality light curves. Using structure functions, we demonstrate that (1) the simplest statistical model of AGN variability, the damped random walk (DRW), is insufficient to characterize the observed behavior of AGN light curves; and (2) variability begins to occur in AGN on time-scales as short as hours. Of the 20 light curves studied by us, only 3-8 may be consistent with the DRW. The structure functions of the AGN in our sample exhibit complex behavior with pronounced dips on time-scales of 10-100 d suggesting that AGN variability can be very complex and merits further analysis. We examine the accuracy of the Kepler pipeline-generated light curves and find that the publicly available light curves may require re-processing to reduce contamination from field sources. We show that while the re-processing changes the exact PSD power law slopes inferred by us, it is unlikely to change the conclusion of our structure function study-Kepler AGN light curves indicate

  18. AGN Observations with STACEE

    NASA Astrophysics Data System (ADS)

    Bramel, D. A.; Boone, L. M.; Carson, J.; Chae, E.; Covault, C. E.; Fortin, P.; Gingrich, D. M.; Hanna, D. S.; Hinton, J. A.; Mukherjee, R.; Mueller, C.; Ong, R. A.; Ragan, K.; Scalzo, R. A.; Schuette, D. R.; Theoret, C. G.; Williams, D. A.; Wong, J.; Zweerink, J.

    2003-03-01

    The Solar Tower Atmospheric Cherenkov Effect Experiment (STACEE) is a gamma-ray detector designed to study astrophysical sources at energies between 50 and 500 GeV. It uses 64 large, steerable mirrors at the National Solar Tower Test Facility near Albuquerque, NM, USA to collect Cherenkov light from extended air showers and concentrate it onto an array of photomultiplier tubes. The large light-collection area gives it a lower energy threshold than imaging-type Cherenkov detectors. STACEE is now fully operational, and we report here on the performance of the complete STACEE instrument, as well as preliminary results of recent observations of several AGN targets. This work was supported in part by the National Science Foundation (under Grant Numbers PHY-9983836, PHY-0070927, and PHY-0070953), the Natural Sciences and Engineering Research Council, Le Fond Quebecois de la Recherche sur la Nature et les Technologies (FQRNT), the Research Corporation, and the California Space Institute. CEC is a Cottrell Scholar of the Research Corporation.

  19. Intermittent Activity in AGN

    NASA Astrophysics Data System (ADS)

    Janiuk, A.; Czerny, B.; Siemiginowska, A.

    2004-10-01

    There is a growing evidence that the AGN activity could be intermittent. It remains an open question if this behavior is caused by changes in the fuel sup- ply to the supermassive black hole from the large distances, or rather by a processes intrinsic to the active nucleus. We consider the possibility that ac- cretion onto a supermassive black hole is controlled by an accretion disk which is subject to the hydro- gen ionization instability. This drives the observed on-off activity cycle, since periodically the accretion flow becomes inefficient and the disk goes to quies- cence. We consider effects of the MHD turbulence on the viscosity during the evolution of a standard α - disk. We perform a self-consistency check of the α de- scription of the angular momentum transfer. Hav- ing shown that the viscosity parameter is constant throughout the whole instability cycle, as implied by the strength of the MHD turbulence, we calcu- late the time evolution of the disk under the influ- ence of the ionization instability. We demonstrate that if the accretion onto a supermassive black hole proceeds through an outer standard accretion disk and inner, radiatively inefficient and advection dom- inated flow, the modelled amplitudes of disk lumi- nosity variations are sufficiently high to account for the observations. Key words: accretion disks; galaxies: active.

  20. AGN jets as pion factories

    NASA Astrophysics Data System (ADS)

    Mannheim, Karl

    There has been a dramatic revolution in gamma-ray astronomy throughout the last few years. Beginning with the discovery made by the spark chamber EGRET on board the Compton Gamma Ray Observatory that AGN with jets are the most powerful quasi-steady gamma-ray sources in the Universe, air-Cerenkov telescopes have soon after succeeded in detecting gamma-rays up to TeV energies. In the last year, it has become clear that these AGN emit photons even up to 10 TeV and more. This is a strong indication for proton acceleration going on in them, since protons owing to their large mass suffer weaker energy losses than electrons and can thus reach higher energies. Nucleons escaping from the AGN jets contribute to the local flux of cosmic rays at highest energies. If AGN produce the diffuse gamma-ray background, they would also be able to produce all the cosmic rays above the ankle in the local spectrum. The majority of AGN resides at large distances, indicated by their cosmological redshifts, and can therefore not be seen through the fog of electron-positron pairs which they produce interacting with diffuse infrared radiation from the era of galaxy formation. To observe the cosmic accelerators at large redshifts, neutrino observations are required. It is important to understand the astrophysical neutrino sources in order to be able to recognize signatures of new physics, e.g. due to decaying or annihilating particles from the early phases of the Universe.

  1. Antineutrophil cytoplasmic antibodies crescentic allograft glomerulonephritis after sofosbuvir therapy

    PubMed Central

    Gadde, Shilpa; Lee, Belinda; Kidd, Laura; Zhang, Rubin

    2016-01-01

    Antineutrophil cytoplasmic antibodies (ANCA) are well known to be associated with several types of vasculitis, including pauci-immune crescentic glomerulonephritis, a form of rapid progressive glomerular nephritis (RPGN). ANCA vasculitis has also been reported after administration of propylthiouracil, hydralazine, cocaine (adulterated with levimasole), allopurinol, penicillamine and few other drugs. All previously reported cases of drug-associated ANCA glomerulonephritis were in native kidneys. Sofosbuvir is a new and effective drug for hepatitis C virus infection. Here, we report a case of ANCA vasculitis and RPGN following sofosbuvir administration in a kidney transplant recipient. It also represents the first case of drug-associated ANCA vasculitis in a transplanted kidney. Further drug monitoring is necessary to elucidate the degree of association and possible causal effect of sofosbuvir and perinuclear ANCA vasculitis. PMID:27872837

  2. Poststreptococcal glomerulonephritis in a patient with essential thrombocytosis.

    PubMed

    Ulusoy, Sukru; Ozkan, Gulsum; Sonmez, Mehmet; Mungan, Sevdegül; Köseoğlu, Rahman; Cansız, Muammer; Kaynar, Kübra

    2015-01-01

    In addition to being the main cause of glomerulonephritis in children, poststreptococcal glomerulonephritis (PSGN) has recently been shown in older patients, especially those with malignancy or diabetes mellitus. The pathogenesis of PSGN has been ascribed to activation of complement 3 (C3) of the alternative complement cascade which, along with immunoglobulin (Ig) G and IgM deposits, is observed in renal tissue. Our aim here is to discuss the probable causes of PSGN developing with isolated IgM deposition in a 52-year-old patient with essential thrombocytosis followed-up over the previous 3.5 years. These characteristics make our case the first to be reported in the literature.

  3. Primary glomerulonephritis: A review of important recent discoveries.

    PubMed

    Floege, Jürgen

    2013-09-01

    The publication of the Kidney Disease: Improving Global Outcomes (KDIGO) guidelines on the treatment of glomerular diseases in 2012 marked a milestone in this field, as it is the first time that comprehensive guidelines are provided for such disease entities. The current review focuses on major findings, both pathogenesis related and clinical, in the primary glomerulonephritis that have been made after the guidelines came into effect.

  4. Primary glomerulonephritis: A review of important recent discoveries

    PubMed Central

    Floege, Jürgen

    2013-01-01

    The publication of the Kidney Disease: Improving Global Outcomes (KDIGO) guidelines on the treatment of glomerular diseases in 2012 marked a milestone in this field, as it is the first time that comprehensive guidelines are provided for such disease entities. The current review focuses on major findings, both pathogenesis related and clinical, in the primary glomerulonephritis that have been made after the guidelines came into effect. PMID:26877924

  5. Heavily Obscured AGN with SIMBOL-X

    SciTech Connect

    Ceca, R. Della; Caccianiga, A.; Severgnini, P.

    2009-05-11

    By comparing an optically selected sample of narrow lines AGN with an X-ray selected sample of AGN we have recently derived an estimate of the intrinsic (i.e. before absorption) 2-10 keV luminosity function (XLF) of Compton Thick AGNs. We will use this XLF to derive the number of Compton Thick AGN that will be found in the SIMBOL-X survey(s)

  6. Heavily Obscured AGN with SIMBOL-X

    NASA Astrophysics Data System (ADS)

    Della Ceca, R.; Caccianiga, A.; Severgnini, P.

    2009-05-01

    By comparing an optically selected sample of narrow lines AGN with an X-ray selected sample of AGN we have recently derived an estimate of the intrinsic (i.e. before absorption) 2-10 keV luminosity function (XLF) of Compton Thick AGNs. We will use this XLF to derive the number of Compton Thick AGN that will be found in the SIMBOL-X survey(s).

  7. Pauci-immune crescentic glomerulonephritis in the Down's syndrome.

    PubMed

    Cherif, Mejda; Hedri, Hafedh; Ounissi, Mondher; Gergah, Taher; Goucha, Rim; Barbouch, Samia; Abderrahim, Ezzedine; Maiz, Hedi Ben; Kheder, Adel

    2013-11-01

    Kidney disease is a rare complication in patients with the Down's syndrome. However, with increased survival, it appears that a growing number of these patients present with glomerulonephritis. Most cases have been reported as case reports and include lesions such as mesangiocapillary glomerulonephritis with hypo-complementemia, crescentic glomerulonephritis with anti-neutrophil cytoplasmic antibodies (ANCA), amyloidosis and immunotactoid glomerulopathy. We report the observation of a 38-year-old man with the Down's syndrome who presented with severe renal failure, proteinuria and microscopic hematuria evolving over two months. There was no history of congenital heart disease or urinary symptoms. Percutaneous renal biopsy revealed fibrous crescents, rupture of Bowman's capsule and peri-glomerular granuloma; there were no deposits on immunofluorescence study. Thoracic computerized tomography scan showed alveolar congestion. The patient tested negative for ANCA. At the time of reporting, the patient is on regular chronic hemodialysis. Our case illustrates a distinct entity that further expands the spectrum of renal disease known to occur in the Down's syndrome. Early detection of the renal disorders may prevent or slow down the progression.

  8. [Nephrotic syndrome presumable caused by an complex glomerulonephritis (author's transl)].

    PubMed

    Seelig, H P; Seelig, R; Fischer, K; Maurer, R; Safer, A; Schnitzlein, W

    1977-04-29

    The nephrotic syndrome presumably caused by an immune complex glomerulonephritis constitutes a major side effect attendant upon chronic administration of penicillamine. The possible induction of an immune-complex glomerulonephritis by penicillamine and its further development after stopping the drug was investigated in rats. --60 rats were fed perorally 2000 mg D-Penicillamine/kg BW/die resp. for a period of 8--44 days. Following unilateral nephrectomy the animals were observed for further 5 weeks. --Dependent to the time of penicillamine application there was an increasing deposition of IgG and C3 in a granular pattern along the glomerular basement membrane and within the mesangium. The IgG deposits initially were focal and segmental later on diffuse and global in distribution. 5 weeks after stopping the penicillamine the immune globulin deposits had disappeared completely or at least in part as did the mild focal glomerulonephritis and the moderate proteinuria which developed in some animals after a 44 day treatment with penicillamine. --The results confirm the hitherto presumed immune complex pathogenesis of the penicillamine induced nephropathy. The disappearance of the immunoglobulins deposited and of proteinuria stopping penicillamine alludes the good prognosis of this kind of nephropathy.

  9. Effectiveness of mycophenolate mofetil in C3 glomerulonephritis.

    PubMed

    Rabasco, Cristina; Cavero, Teresa; Román, Elena; Rojas-Rivera, Jorge; Olea, Teresa; Espinosa, Mario; Cabello, Virginia; Fernández-Juarez, Gema; González, Fayna; Ávila, Ana; Baltar, José María; Díaz, Montserrat; Alegre, Raquel; Elías, Sandra; Antón, Monserrat; Frutos, Miguel Angel; Pobes, Alfonso; Blasco, Miguel; Martín, Francisco; Bernis, Carmen; Macías, Manuel; Barroso, Sergio; de Lorenzo, Alberto; Ariceta, Gema; López-Mendoza, Manuel; Rivas, Begoña; López-Revuelta, Katia; Campistol, José María; Mendizábal, Santiago; de Córdoba, Santiago Rodríguez; Praga, Manuel

    2015-11-01

    C3 glomerulonephritis is a clinicopathologic entity defined by the presence of isolated or dominant deposits of C3 on immunofluorescence. To explore the effect of immunosuppression on C3 glomerulonephritis, we studied a series of 60 patients in whom a complete registry of treatments was available over a median follow-up of 47 months. Twenty patients had not received immunosuppressive treatments. In the remaining 40 patients, 22 had been treated with corticosteroids plus mycophenolate mofetil while 18 were treated with other immunosuppressive regimens (corticosteroids alone or corticosteroids plus cyclophosphamide). The number of patients developing end-stage renal disease was significantly lower among treated compared with untreated patients (3 vs. 7 patients, respectively). No patient in the corticosteroids plus mycophenolate mofetil group doubled serum creatinine nor developed end-stage renal disease, as compared with 7 (significant) and 3 (not significant), respectively, in patients treated with other immunosuppressive regimens. Renal survival (100, 80, and 72% at 5 years) and the number of patients achieving clinical remission (86, 50, and 25%) were significantly higher in patients treated with corticosteroids plus mycophenolate mofetil as compared with patients treated with other immunosuppressive regimens and untreated patients, respectively. Thus, immunosuppressive treatments, particularly corticosteroids plus mycophenolate mofetil, can be beneficial in C3 glomerulonephritis.

  10. The classification of glomerulonephritis in systemic lupus erythematosus revisited.

    PubMed

    Weening, Jan J; D'Agati, Vivette D; Schwartz, Melvin M; Seshan, Surya V; Alpers, Charles E; Appel, Gerald B; Balow, James E; Bruijn, Jan A; Cook, Terence; Ferrario, Franco; Fogo, Agnes B; Ginzler, Ellen M; Hebert, Lee; Hill, Gary; Hill, Prue; Jennette, J Charles; Kong, Norella C; Lesavre, Philippe; Lockshin, Michael; Looi, Lai-Meng; Makino, Hirofumi; Moura, Luiz A; Nagata, Michio

    2004-02-01

    The currently used classification reflects our understanding of the pathogenesis of the various forms of lupus nephritis, but clinicopathologic studies have revealed the need for improved categorization and terminology. Based on the 1982 classification published under the auspices of the World Health Organization (WHO) and subsequent clinicopathologic data, we propose that class I and II be used for purely mesangial involvement (I, mesangial immune deposits without mesangial hypercellularity; II, mesangial immune deposits with mesangial hypercellularity); class III for focal glomerulonephritis (involving <50% of total number of glomeruli) with subdivisions for active and sclerotic lesions; class IV for diffuse glomerulonephritis (involving > or = 50% of total number of glomeruli) either with segmental (class IV-S) or global (class IV-G) involvement, and also with subdivisions for active and sclerotic lesions; class V for membranous lupus nephritis; and class VI for advanced sclerosing lesions]. Combinations of membranous and proliferative glomerulonephritis (i.e., class III and V or class IV and V) should be reported individually in the diagnostic line. The diagnosis should also include entries for any concomitant vascular or tubulointerstitial lesions. One of the main advantages of the current revised classification is that it provides a clear and unequivocal description of the various lesions and classes of lupus nephritis, allowing a better standardization and lending a basis for further clinicopathologic studies. We hope that this revision, which evolved under the auspices of the International Society of Nephrology and the Renal Pathology Society, will contribute to further advancement of the WHO classification.

  11. The classification of glomerulonephritis in systemic lupus erythematosus revisited.

    PubMed

    Weening, Jan J; D'Agati, Vivette D; Schwartz, Melvin M; Seshan, Surya V; Alpers, Charles E; Appel, Gerald B; Balow, James E; Bruijn, Jan A; Cook, Terence; Ferrario, Franco; Fogo, Agnes B; Ginzler, Ellen M; Hebert, Lee; Hill, Gary; Hill, Prue; Jennette, J Charles; Kong, Norella C; Lesavre, Philippe; Lockshin, Michael; Looi, Lai-Meng; Makino, Hirofumi; Moura, Luiz A; Nagata, Michio

    2004-02-01

    The currently used classification reflects our understanding of the pathogenesis of the various forms of lupus nephritis, but clinicopathologic studies have revealed the need for improved categorization and terminology. Based on the 1982 classification published under the auspices of the World Health Organization (WHO) and subsequent clinicopathologic data, we propose that class I and II be used for purely mesangial involvement (I, mesangial immune deposits without mesangial hypercellularity; II, mesangial immune deposits with mesangial hypercellularity); class III for focal glomerulonephritis (involving <50% of total number of glomeruli) with subdivisions for active and sclerotic lesions; class IV for diffuse glomerulonephritis (involving > or =50% of total number of glomeruli) either with segmental (class IV-S) or global (class IV-G) involvement, and also with subdivisions for active and sclerotic lesions; class V for membranous lupus nephritis; and class VI for advanced sclerosing lesions. Combinations of membranous and proliferative glomerulonephritis (i.e., class III and V or class IV and V) should be reported individually in the diagnostic line. The diagnosis should also include entries for any concomitant vascular or tubulointerstitial lesions. One of the main advantages of the current revised classification is that it provides a clear and unequivocal description of the various lesions and classes of lupus nephritis, allowing a better standardization and lending a basis for further clinicopathologic studies. We hope that this revision, which evolved under the auspices of the International Society of Nephrology and the Renal Pathology Society, will contribute to further advancement of the WHO classification.

  12. AGN identification: what lies ahead

    NASA Astrophysics Data System (ADS)

    Fotopoulou, Sotiria

    2016-08-01

    Classification has been one the first concerns of modern astronomy, starting from stars sorted in the famous Harvard classification system and promptly followed by the morphological classification of galaxies by none other than Edwin Hubble himself (Hubble 1926). Both classification schema are essentially connected to the physics of the objects reflecting the temperature for stars and e.g. the age of the star population for galaxies. Systematic observations of galaxies have revealed the intriguing class of Active Galactic Nuclei (AGN), objects of tremendous radiation that do not share the same properties of what we now call normal galaxies. Observations have led to the definition of distinct and somewhat arbitrary categories (Seyfert galaxies, quasars, QSO, radio AGN, etc), essentially rediscovering the many faces of the same phenomenon, up until the unification of AGN (Antonucci 1993, Urry and Padovani 1995). Even after the realization that all AGN have the same engine powering their amazing radiation, astronomers are still using and refining the selection criteria within their favorite electromagnetic range in the hope to better understand the impact of the AGN phenomenon in the greater context of galaxy evolution. In the dawn of Big Data astronomy we find ourselves equipped with new tools. I will present the prospects of machine learning methods in better understanding the AGN population. Namely, I will show results from supervised learning algorithms whereby a labeled training set is used to amalgamate decision tree(s) (Fotopoulou et al., 2016) or neural network(s), and unsupervised learning where the algorithm performs clustering analysis of the full dataset in a multidimensional space identifying clusters of objects sharing potentially the same physical properties (Fotopoulou in prep.).

  13. Fading AGN Candidates: AGN Histories and Outflow Signatures

    NASA Astrophysics Data System (ADS)

    Keel, William C.; Lintott, Chris J.; Maksym, W. Peter; Bennert, Vardha N.; Chojnowski, S. Drew; Moiseev, Alexei; Smirnova, Aleksandrina; Schawinski, Kevin; Sartori, Lia F.; Urry, C. Megan; Pancoast, Anna; Schirmer, Mischa; Scott, Bryan; Showley, Charles; Flatland, Kelsi

    2017-02-01

    We consider the energy budgets and radiative history of eight fading active galactic nuclei (AGNs), identified from an energy shortfall between the requirements to ionize very extended (radius > 10 kpc) ionized clouds and the luminosity of the nucleus as we view it directly. All show evidence of significant fading on timescales of ≈50,000 yr. We explore the use of minimum ionizing luminosity Qion derived from photoionization balance in the brightest pixels in Hα at each projected radius. Tests using presumably constant Palomar–Green QSOs, and one of our targets with detailed photoionization modeling, suggest that we can derive useful histories of individual AGNs, with the caveat that the minimum ionizing luminosity is always an underestimate and subject to uncertainties about fine structure in the ionized material. These consistency tests suggest that the degree of underestimation from the upper envelope of reconstructed Qion values is roughly constant for a given object and therefore does not prevent such derivation. The AGNs in our sample show a range of behaviors, with rapid drops and standstills; the common feature is a rapid drop in the last ≈2 × 104 yr before the direct view of the nucleus. The e-folding timescales for ionizing luminosity are mostly in the thousands of years, with a few episodes as short as 400 yr. In the limit of largely obscured AGNs, we find additional evidence for fading from the shortfall between even the lower limits from recombination balance and the maximum luminosities derived from far-infrared fluxes. We compare these long-term light curves, and the occurrence of these fading objects among all optically identified AGNs, to simulations of AGN accretion; the strongest variations over these timespans are seen in models with strong and local (parsec-scale) feedback. We present Gemini integral-field optical spectroscopy, which shows a very limited role for outflows in these ionized structures. While rings and loops of emission

  14. The Close AGN Reference Survey (CARS)

    NASA Astrophysics Data System (ADS)

    Rothberg, Barry; Husemann, Bernd; Busch, Gerold; Dierkes, Jens; Eckart, Andreas; Krajnovic, Davor; Scharwaechter, Julia; Tremblay, Grant R.; Urrutia, Tanya

    2015-08-01

    We present the first science results from the Close AGN Reference Survey (CARS). This program is a snapshot survey of 39 local type 1 AGN (0.01 < z <0.06) designed to address the issue of AGN-driven star formation quenching by characterizing the condition for star formation in AGN host galaxies. The primary sample was observed with Multi Unit Spectrscopic Explorer (MUSE), an optical wavelength integral field unit (IFU) with a 1'x1' field of view on the VLT. The optical 3D spectroscopy complements existing sub-mm CO(1-0) data and near-IR imaging to establish a unique dataset combining molecular and stellar masses with star formation rates, gas, stellar kinematics and AGN properties. The primary goals of CARS are to:1) investigate if the star formation efficiency and gas depletion time scales are suppressed as a consequence of AGN feedback; 2) identify AGN-driven outflows and their relation to the molecular gas reservoir of the host galaxy; 3) investigate the the balance of AGN feeding and feedback through the ratio of the gas reservoir to the AGN luminosity; and 4) provide the community with a reference survey of local AGN with a high legacy value. Future work will incorporate near-infrared IFU observations to present a complete spatially resolved picture of the interplay among AGN, star-formation, stellar populations, and the ISM.

  15. Be alert to tuberculosis-mediated glomerulonephritis: a retrospective study.

    PubMed

    Sun, L; Yuan, Q; Feng, J; Yao, L; Fan, Q; Ma, J; Wang, L

    2012-05-01

    Mycobacterium tuberculosis infection causing glomerulonephritis is a rare disorder. This retrospective study analyzed the clinical characteristics of patients diagnosed with tuberculosis-mediated glomerulonephritis (TB-GN) between 2002 and 2009, as well as the diagnostic tools used. These findings were then compared with those of patients with primary glomerulonephritis (P-GN). The records of all patients were reviewed. The diagnosis of TB-GN was based on renal hematuria and/or proteinuria and cure after antituberculosis therapy alone plus urine culture positive for M. tuberculosis, demonstration of typical tubercle granulomas on renal biopsy specimens, or the detection of M. tuberculosis DNA by polymerase chain reaction (PCR) on renal specimens. Forty-six patients with TB-GN and 49 patients with P-GN were included. Compared with patients in the P-GN group, most (76%) patients with TB-GN had a history of TB. Systemic symptoms were much more frequent in patients with TB-GN than local genitourinary symptoms. Serological testing showed a statistical difference between the two groups. Immunoglobulin A nephropathy was found in the majority (72%) of patients with TB-GN. M. tuberculosis DNA detection was positive in 39 (84.8%) patients, a much higher positive rate of diagnosis than that with urine culture for M. tuberculosis. The manifestation of TB-GN is atypical and nonspecific. It warrants a high index of suspicion when patients with renal hematuria and proteinuria fail to respond to standard treatments for P-GN. Clinicians should pay close attention to the medical history and results of special laboratory tests. M. tuberculosis DNA detection on renal biopsy specimens should be considered in order to confirm the diagnosis of TB-GN.

  16. Infantile immunoglobulin A nephropathy showing features of membranoproliferative glomerulonephritis.

    PubMed

    Kurosu, Akira; Oka, Noriko; Hamaguchi, Takeshi; Yoshikawa, Norishige; Joh, Kensuke

    2012-01-01

    Immunoglobulin A nephropathy (IgAN) showing predominant IgA and complement 3 (C3) deposition on the mesangium is an immune complex-mediated glomerulonephritis. This renal disease is the most common primary glomerular disease worldwide. However, infantile onset of IgAN is rare. In the present patient, urinary protein and occult blood were detected in a girl aged 1 year and 8 months on urinalysis at a nursery school. Despite being young, a kidney biopsy was performed for diagnosis and the correct choice of therapy. Glomerular mesangial cell proliferation and a double contour of the glomerular basement membrane (GBM) resembling a railroad track were noted on light microscopy. Therefore, the patient was diagnosed morphologically with membranoproliferative glomerulonephritis (MPGN), because mesangial hypercellularity and thickening of the GBM were identified. However, on immunofluorescent staining, the deposition of immune complexes mainly consisting of IgA, IgG, and C3 was noted in the mesangial region and glomerular capillary loops. On electron microscopy, electron-dense deposits were recognized in the subendothelial and paramesangial regions associated with mesangial cell interposition into the subendothelial space. Autoimmune diseases and infection-associated secondary glomerulonephritis were clinically excluded, because there were no relevant signs or symptoms. Steroid treatment was initiated and findings of urinalysis were normalized within 8 months. This patient was finally diagnosed with IgA nephropathy showing the features of MPGN. The present patient was the youngest among reported cases of IgA nephropathy, suggesting that early onset of IgAN is associated with an MPGN-like lesion. The present report provides information for pathogenesis of IgA nephropathy.

  17. Proliferative glomerulonephritis with monoclonal IgG deposits in a patient with autoimmune hemolytic anemia.

    PubMed

    Fujiwara, Takashi; Komatsuda, Atsushi; Ohtani, Hiroshi; Togashi, Masaru; Sawada, Ken-Ichi; Wakui, Hideki

    2013-06-01

    A 25-year-old woman was admitted because of proteinuria. A renal biopsy showed mesangial/endocapillary proliferative glomerulonephritis with IgG2-κ deposits. Electron microscopy showed immune complex-type deposits. She also had Coombs-positive hemolytic anemia, anticardiolipin antibodies, and antinuclear antibodies. Middle-dose steroid therapy led to improvement of proteinuria and hemolytic anemia. Six years later, she developed crescentic glomerulonephritis with IgG2-κ deposits during pregnancy. Middle-dose steroid therapy improved renal dysfunction. This is an exceptional case of proliferative glomerulonephritis with monoclonal IgG deposits (PGNMID), a recently described rare dysproteinemia-related glomerulonephritis, associated with autoimmune disease. This case also suggests that crescentic glomerulonephritis can be superimposed on PGNMID.

  18. Monoclonal gammopathy associated membranous glomerulonephritis: A rare entity.

    PubMed

    Gowda, K K; Joshi, K; Ramachandran, R; Nada, R

    2015-01-01

    A 40-year-old male presented with nephrotic syndrome. Light microscopic analysis of the renal biopsy showed thickening of the glomerular capillary wall. Immunofluorescence examination revealed granular deposition of monoclonal immunoglobulin (Ig) G3-kappa and complement C3 along the glomerular basement membrane. Electron microscopy showed subepithelial electron dense deposits, thus confirming membranous glomerulonephritis (MGN) with monoclonal gammopathy. MGN with monoclonal gammopathy is an extremely rare but distinctive entity. This patient was treated with a combination of bortezomib, thalidomide and dexamethasone and showed partial remission of his nephrotic state and dysproteinemia.

  19. Accretion Rate: An Axis Of Agn Unification

    NASA Astrophysics Data System (ADS)

    Trump, Jonathan R.; Impey, C. D.; Kelly, B. C.

    2011-01-01

    We show how accretion rate governs the physical properties of broad-line, narrow-line, and lineless active galactic nuclei (AGNs). We avoid the systematic errors plaguing previous studies of AGN accretion rate by using accurate accretion luminosities from well-sampled multiwavelength SEDs from the Cosmic Evolution Survey (COSMOS), and accurate black hole masses derived from virial scaling relations (for broad-line AGNs) or host-AGN relations (for narrow-line and lineless AGNs). In general, broad emission lines are present only at the highest accretion rates (L/L_Edd>0.01), and these rapidly accreting AGNs are observed as broad-line AGNs or possibly as obscured narrow-line AGNs. Narrow-line and lineless AGNs at lower specific accretion rates (L/L_Edd<0.01) are unobscured and yet lack a broad line region. The disappearance of the broad emission lines is caused by an expanding radiatively inefficient accretion flow (RIAF) at the inner radius of the accretion disk. The presence of the RIAF also drives L/L_Edd<0.01 narrow-line and lineless AGNs to be 10-100 times more radio-luminous than broad-line AGNs, since the unbound nature of the RIAF means it is easier to form a radio outflow. The IR torus signature also tends to become weaker or disappear from L/L_Edd<0.01 AGNs, although there may be additional mid-IR synchrotron emission associated with the RIAF. Together these results suggest that specific accretion rate is an important physical "axis" of AGN unification, described by a simple model.

  20. Non-thermal AGN models

    SciTech Connect

    Band, D.L.

    1986-12-01

    The infrared, optical and x-ray continua from radio quiet active galactic nuclei (AGN) are explained by a compact non-thermal source surrounding a thermal ultraviolet emitter, presumably the accretion disk around a supermassive black hole. The ultraviolet source is observed as the ''big blue bump.'' The flat (..cap alpha.. approx. = .7) hard x-ray spectrum results from the scattering of thermal ultraviolet photons by the flat, low energy end of an electron distribution ''broken'' by Compton losses; the infrared through soft x-ray continuum is the synchrotron radiation of the steep, high energy end of the electron distribution. Quantitative fits to specific AGN result in models which satisfy the variability constraints but require electron (re)acceleration throughout the source. 11 refs., 1 fig.

  1. Gamma-ray-selected AGN

    NASA Astrophysics Data System (ADS)

    Giommi, Paolo

    2016-08-01

    The gamma-ray band is the most energetic part of the electromagnetic spectrum. As such it is also where selection effects are most severe, as it can only be reached by the most extreme non-thermal AGN. Blazars, with their emission dominated by non-thermal blue-shifted radiation arising in a relativistic jet pointed in the direction of the observer, naturally satisfy this though requirement. For this reason, albeit these sources are intrisically very rare (orders of magnitude less abundant than radio quiet AGN of the same optical magnitude) they almost completely dominate the extragalactic gamma-ray and very high energy sky. I will discuss the emission of different types of blazars and the selection effects that are at play in the gamma-ray band based on recent results from the current generation of gamma-ray astronomy satellites, ground-based Cherenkov telescopes, and Monte Carlo simulations.

  2. The Importance of Winds for AGN Feedback

    NASA Astrophysics Data System (ADS)

    Crenshaw, D. M.; Kraemer, S. B.; Schmitt, H. R.; Fischer, T. C.; Gagne, J.

    2014-01-01

    Active galactic nuclei (AGN) are fed by accretion of matter onto supermassive black holes (SMBHs), generating huge amounts of radiation from very small volumes. AGN also provide feedback to their environments via mass outflows of ionized gas, which could play a critical role in the formation of large-scale structure in the early Universe, chemical enrichment of the intergalactic medium, and self-regulation of SMBH and galactic bulge growth. We provide an update on our research on the winds in nearby moderate-luminosity AGN, In particular, we concentrate on winds that occur on relatively large scales (hundreds of parsecs) that are revealed through spatially resolved HST spectra of emission-line gas in the narrow line regions (NLRs) of nearby AGN. We discuss the techniques for measuring the mass outflow rates and kinetic luminosities of these AGN winds and gauge their importance for providing significant AGN feedback.

  3. Comparing Simulations of AGN Feedback

    NASA Astrophysics Data System (ADS)

    Richardson, Mark L. A.; Scannapieco, Evan; Devriendt, Julien; Slyz, Adrianne; Thacker, Robert J.; Dubois, Yohan; Wurster, James; Silk, Joseph

    2016-07-01

    We perform adaptive mesh refinement (AMR) and smoothed particle hydrodynamics (SPH) cosmological zoom simulations of a region around a forming galaxy cluster, comparing the ability of the methods to handle successively more complex baryonic physics. In the simplest, non-radiative case, the two methods are in good agreement with each other, but the SPH simulations generate central cores with slightly lower entropies and virial shocks at slightly larger radii, consistent with what has been seen in previous studies. The inclusion of radiative cooling, star formation, and stellar feedback leads to much larger differences between the two methods. Most dramatically, at z=5, rapid cooling in the AMR case moves the accretion shock to well within the virial radius, while this shock remains near the virial radius in the SPH case, due to excess heating, coupled with poorer capturing of the shock width. On the other hand, the addition of feedback from active galactic nuclei (AGNs) to the simulations results in much better agreement between the methods. For our AGN model, both simulations display halo gas entropies of 100 keV cm2, similar decrements in the star formation rate, and a drop in the halo baryon content of roughly 30%. This is consistent with the AGN growth being self-regulated, regardless of the numerical method. However, the simulations with AGN feedback continue to differ in aspects that are not self-regulated, such that in SPH a larger volume of gas is impacted by feedback, and the cluster still has a lower entropy central core.

  4. New insights into AGN coronae

    NASA Astrophysics Data System (ADS)

    Lohfink, Anne; Fabian, Andrew C.; Malzac, Julien; Belmont, Renaud; Buisson, Douglas

    2016-04-01

    Active galactic nuclei (AGN) are some of the most energetic sources of radiation in the Universe. The conversion of gravitational energy into radiation is thought to take place in an accretion disk/corona system just outside the black hole. In this system thermal, UV/optical photons from the accretion disk are upscattered in a corona of hot electrons situated above the accretion disk producing X-rays. The nature of this Comptonizing corona remains a key open question in AGN physics. The NuSTAR satellite provides the opportunity to study the Comptonization spectrum produced by the corona in great detail. In our talk we will show some key results from these new studies of the Comptonization spectrum. We explore how, together with our growing knowledge of coronal sizes, we are able to draw first conclusions about the physics taking place in the corona. We find evidence for coronae to be hot and radiatively compact, putting them close to the boundary of the region in the compactness-temperature diagram which is forbidden due to runaway pair production. This suggests that pair production and annihilation are essential ingredients in the coronae of AGN and that they control the coronal temperature and shape of the observed spectra.

  5. Pauci-Immune Crescentic Glomerulonephritis in Connective Tissue Disease

    PubMed Central

    Cronin, Mary; Robin, Adam; Lorna, Campbell; Rosenthal, Ann K.

    2016-01-01

    Pauci-immune crescentic glomerulonephritis is commonly seen in ANCA-associated vasculitis but it is rarely seen during the course of other connective tissue diseases like lupus or Sjogren's syndrome or MCTD. We report 3 cases of pauci-immune crescentic glomerulonephritis in patients with connective tissue disease other than vasculitis. We reviewed literature and made summary of previously reported cases of this rare entity. Clinical and laboratory features of these patients varied widely, but most of patients have met criteria for lupus. In this small population of patients there is no correlation with ANCAs. Most of the patients were treated with aggressive immunosuppression and did well if they were treated early in the course of their disease. One of our patients required renal transplant, but she presented late in the course of her disease, as evidenced by chronicity on her renal biopsy. Whether these patients are overlap of vasculitis and other connective tissue diseases or to be considered as a separate entity is yet to be described. Clinicians must be aware of these presentations because initial presentation can be severe. PMID:27504208

  6. Nephrotoxic nephritis and glomerulonephritis: animal model versus human disease.

    PubMed

    Muhammad, S

    2014-01-01

    Glomerulonephritis (GN) encompasses a range of immune-mediated disorders that cause inflammation within the glomerulus of the kidney. The pathogenesis of GN is complex. Intricacy arises from factors such as autoimmunity, cancer and structural abnormalities within the kidney. Studies using animal models have highlighted crucial interaction between inflammatory cells and cells intrinsic to the kidney, both of which are fundamental to the pathogenesis of GN. This review aims to provide insight on a 'suitable' model for nephrotoxic nephritis and glomerulonephritis (NTN GN) and relate its experimental validity to humans. The BALB/c NTN murine model and Wistar Kyoto (WKY) rat have held experimental validity in the study of GN in humans. The chemokine receptor CXCR3 also mediates renal T-cell recruitment and subsequent tissue injury in NTN. It is noteworthy to consider CXCR3 blockade in Th1-mediated renal inflammation as future therapeutic options for patients with GN and subsets thereof. Currently used immunosuppressive therapies for GN are not always uniformly effective and are frequently associated with serious side-effects. Corticosteroids are effective in several types of GN owing to their ability to inhibit the pro-inflammatory effects of cytokines known to promote glomerular inflammation. Differences between experimental and human GN complicate translation of experimental therapies into practice. More research is required to translate animal model research into a better comprehension of human GN disease. However, the complexity of GN research makes findings a challenge to replicate.

  7. Familial C4B Deficiency and Immune Complex Glomerulonephritis

    PubMed Central

    Soto, K; Wu, YL; Ortiz, A; Aparício, SR; Yu, CY

    2010-01-01

    Homozygous complement C4B deficiency is described in a Southern European young female patient with Membranoproliferative Glomerulonephritis (MPGN) type III characterized by renal biopsies with strong complement C4 and IgG deposits. Low C4 levels were independent of clinical evolution or type of immunosuppression and were found in three other family members without renal disease or infections. HLA typing revealed that the patient has homozygous A*02, Cw*06, B*50 at the class I region, and DRB1*08 and DQB1*03 at the class II region. Genotypic and phenotypic studies demonstrated that the patient has homozygous monomodular RCCX in the HLA class III region, with single long C4A genes coding for C4A3 and complete C4B deficiency. Her father, mother, son and niece have heterozygous C4B deficiency. The patient’s deceased brother had a history of Henoch-Schönlein Purpura (HSP), an immune complex-mediated proliferative glomerulonephritis. These findings challenge the putative pathophysiological roles of C4A and C4B and underscore the need to perform functional assays, C4 allotyping and genotyping on patients with persistently low serum levels of a classical pathway complement component and glomerulopathy associated with immune deposits. PMID:20580617

  8. Familial C4B deficiency and immune complex glomerulonephritis.

    PubMed

    Soto, K; Wu, Y L; Ortiz, A; Aparício, S R; Yu, C Y

    2010-10-01

    Homozygous complement C4B deficiency is described in a Southern European young female patient with Membranoproliferative Glomerulonephritis (MPGN) type III characterized by renal biopsies with strong complement C4 and IgG deposits. Low C4 levels were independent of clinical evolution or type of immunosuppression and were found in three other family members without renal disease or infections. HLA typing revealed that the patient has homozygous A*02, Cw*06, B*50 at the class I region, and DRB1*08 and DQB1*03 at the class II region. Genotypic and phenotypic studies demonstrated that the patient has homozygous monomodular RCCX in the HLA class III region, with single long C4A genes coding for C4A3 and complete C4B deficiency. Her father, mother, son and niece have heterozygous C4B deficiency. The patient's deceased brother had a history of Henoch-Schönlein Purpura (HSP), an immune complex-mediated proliferative glomerulonephritis. These findings challenge the putative pathophysiological roles of C4A and C4B and underscore the need to perform functional assays, C4 allotyping and genotyping on patients with persistently low serum levels of a classical pathway complement component and glomerulopathy associated with immune deposits.

  9. Detecting Dual AGN at High Redshift

    NASA Astrophysics Data System (ADS)

    Barrows, Robert S.

    2012-01-01

    The existence of supermassive black holes (SMBHs) in most, if not all, galaxies, along with observations of galaxy mergers, suggests that pairs of SMBHs should exist for some time in the merger remnant. Observational evidence for these systems at kpc-scale separations (i.e. dual AGN) has dramatically increased recently through a combination of spectral and morphological selections. I discuss observations of CXOXBJ142607.6+353351 (CXOJ1426+35), a candidate dual AGN at z=1.175, and put its properties, including significant obscuration, within the context of other candidate/confirmed dual AGN at lower redshifts. Though dual AGN are expected to be more common at higher redshifts, they are more difficult to detect. Furthermore, adding to the difficulties of detection are a number of other physical mechanisms which can mimic the spectroscopic signature of two Type 2 AGN. In particular, I will discuss the possibility of strong outflows from an AGN. These outflow phenomena can be an important feedback mechanism in galaxies and are apparently common in AGN, making them a viable alternative to the dual AGN scenario. Based on our candidate's luminosity and emission line intensities, we find that an outflow is a possibility. If this is the case, such an outflow would be especially strong and has implications for AGN feedback in galaxies. However, the dual AGN scenario cannot be ruled out, and at z=1.175, the two putative AGN could potentially be resolved with Chandra. Other candidate dual AGN at similar redshifts and with significant obscuration could also be confirmed this way. This research was sponsored by the Strategic University Research Partnership Program, the National Aeronautics and Space Administration and the Arkansas NASA EPSCoR program.

  10. AGN feedback in action? - outflows and star formation in type 2 AGNs

    NASA Astrophysics Data System (ADS)

    Woo, Jong-Hak

    2017-01-01

    We present the statistical constraints on the ionized gas outflows and their connection to star formation, using a large sample of ~110,000 AGNs and star-forming galaxies at z < 0.3. First, we find a dramatic difference of the outflow signatures between AGNs and star-forming galaxies based on the [OIII] emission line kinematics. While the [OIII] velocity and velocity dispersion of star forming galaxies can be entirely accounted by the gravitational potential of host galaxies, AGNs clearly show non-gravitational kinematics, which is comparable to or stronger than the virial motion caused by the gravitational potential. Second, the distribution in the [OIII] velocity - velocity dispersion diagram dramatically expands toward large values with increasing AGN luminosity, implying that the outflows are AGN-driven. Third, the fraction of AGNs with a signature of outflow kinematics, steeply increases with AGN luminosity and Eddington ratio. In particular, the majority of luminous AGNs presents strong non-gravitational kinematics in the [OIII] profile. Interestingly, we find that the specific star formation of non-outflow AGNs is much lower than that of strong outflow AGNs, while the star formation rate of strong outflow AGNs is comparable to that of star forming galaxies. We interpret this trend as a delayed AGN feedback as it takes dynamical time for the outflows to suppress star formation in galactic scales.

  11. The Universal Unification Model of AGN

    NASA Astrophysics Data System (ADS)

    Vilkoviskij, E. Y.

    1998-12-01

    It is shown, that the model calculations of the absorption line profiles are possible in the framework of a common model both for BAL QSOs and the Seyfert galaxies with BAL. We suppose that in both cases the BAL-clouds move in the space between two conic surface, starting in the internal surface of the absorbing torus. We argue that the common nature of the intrinsic line absorption in these objects can be explained in an universal unified AGN model, where BAL AGNs are objects intermediate between AGN1 and AGN2

  12. Probing AGN Unification with galaxy neighbours: pitfalls and prospects

    NASA Astrophysics Data System (ADS)

    Villarroel, B.

    2015-09-01

    Statistical tests of AGN unification harbour many caveats. One way of constraining the validity of the AGN unification is through studies of close neighbours to Type-1 and Type-2 AGN. Examining thousands of AGN- galaxy pairs from the Sloan Digital Sky Survey Data Release 7 and the Galaxy Zoo project, we found that Type-2 AGN appear to reside in more star-forming environments than Type-1 AGN.

  13. Combined optical coherence tomography and optical coherence elastography for glomerulonephritis classification

    NASA Astrophysics Data System (ADS)

    Liu, Chih-Hao; Du, Yong; Singh, Manmohan; Wu, Chen; Han, Zhaolong; Li, Jiasong; Mohammadzai, Qais; Raghunathan, Raksha; Hsu, Thomas; Noorani, Shezaan; Chang, Anthony; Mohan, Chandra; Larin, Kirill V.

    2016-03-01

    Acute Glomerulonephritis caused by anti-glomerular basement membrane disease has a high mortality due to delayed diagnosis. Thus, an accurate and early diagnosis is critical for preserving renal function. Currently, blood, urine, and tissue-based diagnoses can be time consuming, while ultrasound and CT imaging have relatively low spatial resolution. Optical coherence tomography (OCT) is a noninvasive imaging technique that provides superior spatial resolution (micron scale) as compared to ultrasound and CT. Pathological changes in tissue properties can be detected based on the optical metrics analyzed from the OCT signal, such as optical attenuation and speckle variance. Moreover, OCT does not rely on ionizing radiation as with CT imaging. In addition to structural changes, the elasticity of the kidney can significantly change due to nephritis. In this work, we utilized OCT to detect the difference in tissue properties between healthy and nephritic murine kidneys. Although OCT imaging could identify the diseased tissue, classification accuracy using only optical metrics was clinically inadequate. By combining optical metrics with elasticity, the classification accuracy improved from 76% to 95%. These results show that OCT combined with OCE can be potentially useful for nephritis detection.

  14. Polymorphisms in NADPH oxidase CYBA gene modify the risk of ESRD in patients with chronic glomerulonephritis.

    PubMed

    Zhou, Hui; Chen, Min; Zhu, Ying; Wang, Bing; Liu, Xiao-ning; Zuo, Zhi; Tang, Feng-Ying

    2016-01-01

    End-stage renal disease (ESRD) was defined as start of renal replacement therapy or death due to kidney disease. However, death due to acute kidney injury was not included. It typically occurs when chronic renal failure progresses to a point where the kidneys are permanently functioning at less than 10% of their capacity. Oxidative stress (OS) plays a crucial role in ESRD. Nicotinamide adenine dinucleotide phosphate (NADPH) is one of the most important enzymes during oxidative stress. Cytochrome b light chain (CYBA), encoded by a polymorphic gene, which is a critical component of the nicotinamide adenine dinucleotide (NADH)/NADPH oxidase system and plays an important role in electron transport and superoxide anion production, is located on chromosome band 16q24 and has six exons spanning almost 7.76 kb of genomic DNA. CYBA gene polymorphisms can influence the activity of NADPH oxidase. To evaluate the association between CYBA gene polymorphisms and ESRD, we genotyped five CYBA polymorphisms using TaqMan allelic discrimination assay on DNA samples from 306 healthy controls and 332 patients with ESRD. Our results suggested that rs1049255 polymorphism of CYBA modified the risk of ESRD (p  =  0.019; OR  =  0.625; 95%CI  =  0.424-0.921). GG genotype and G allele might be a protective factor against the risk of ESRD, especially in patients with chronic glomerulonephritis.

  15. A Case of Concurrent MPO-/PR3-Negative ANCA-Associated Glomerulonephritis and Membranous Glomerulopathy

    PubMed Central

    Nakada, Yasuyuki; Tsuboi, Nobuo; Takahashi, Yasuto; Yoshida, Hiraku; Hara, Yoriko; Okonogi, Hideo; Kawamura, Tetsuya; Arimura, Yoshihiro; Yokoo, Takashi

    2015-01-01

    We report a case in which antineutrophil cytoplasmic antibody- (ANCA-) associated glomerulonephritis and membranous glomerulopathy (MGN) were detected concurrently. The patient showed rapidly progressive renal deterioration. A renal biopsy showed crescentic glomerulonephritis, together with marked thickening and spike and bubbling formations in the glomerular basement membranes. Indirect immunofluorescence examination of the patient's neutrophils showed a perinuclear pattern. Enzyme-linked immunosorbent assays revealed that the ANCA in this case did not target myeloperoxidase (MPO) or proteinase 3 (PR3) but bactericidal-/permeability-increasing protein, elastase, and lysosome. The relationship between these two etiologically distinct entities, MPO-/PR3-negative ANCA-associated glomerulonephritis and MGN, remains unclear. PMID:25648906

  16. SWIFT BAT Survey of AGN

    NASA Technical Reports Server (NTRS)

    Tueller, J.; Mushotzky, R. F.; Barthelmy, S.; Cannizzo, J. K.; Gehrels, N.; Markwardt, C. B.; Skinner, G. K.; Winter, L. M.

    2008-01-01

    We present the results1 of the analysis of the first 9 months of data of the Swift BAT survey of AGN in the 14-195 keV band. Using archival X-ray data or follow-up Swift XRT observations, we have identified 129 (103 AGN) of 130 objects detected at [b] > 15deg and with significance > 4.8-delta. One source remains unidentified. These same X-ray data have allowed measurement of the X-ray properties of the objects. We fit a power law to the logN - log S distribution, and find the slope to be 1.42+/-0.14. Characterizing the differential luminosity function data as a broken power law, we find a break luminosity logL*(ergs/s)= 43.85+/-0.26. We obtain a mean photon index 1.98 in the 14-195 keV band, with an rms spread of 0.27. Integration of our luminosity function gives a local volume density of AGN above 10(exp 41) erg/s of 2.4x10(exp -3) Mpc(sup -3), which is about 10% of the total luminous local galaxy density above M* = -19.75. We have obtained X-ray spectra from the literature and from Swift XRT follow-up observations. These show that the distribution of log nH is essentially flat from nH = 10(exp 20)/sq cm to 10(exp 24)/sq cm, with 50% of the objects having column densities of less than 10(exp 22)/sq cm. BAT Seyfert galaxies have a median redshift of 0.03, a maximum log luminosity of 45.1, and approximately half have log nH > 22.

  17. Measuring Feedback in Nearby AGN

    NASA Astrophysics Data System (ADS)

    Crenshaw, D. M.; Fischer, T. C.; Kraemer, S. B.; Schmitt, H. R.; Turner, T. J.

    2012-08-01

    We investigate the impact of feedback from outflowing UV and X-ray absorbers in nearby (z < 0.04) AGN. From studies of the kinematics, physical conditions, and variability of the absorbers in the literature, we calculate the possible ranges in total mass outflow rate (Ṁout) and kinetic luminosity (LK) for each AGN, summed over all of the absorbers. These calculations make use of values (or limits) for the radial locations of the absorbers determined from variability, excited-state absorption, or other considerations. From a sample of 10 Seyfert 1 galaxies with detailed photoionization models for their absorbers, we find that 7 have sufficient constraints on the absorber locations to determine Ṁout and LK. The 6 Seyfert 1s with moderate bolometric luminosities (Lbol = 1043 - 1045 ergs s-1) all have mass outflow rates that are 10 - 1000 times the mass accretion rates needed to generate their observed luminosities, indicating that most of the mass outflow originates from outside the inner accretion disk. Three of these (NGC 4051, NGC 3516, and NGC 3783) have LK in the range 0.5 - 5% Lbol, which is the range typically required by feedback models for efficient self-regulation of black-hole and galactic bulge growth. The other three (NGC 5548, NGC 4151, and NGC 7469) have LK > 0.1%Lbol, although these values may increase if radial locations can be determined for more of the absorbers. We conclude that the outflowing UV and X-ray absorbers in moderate-luminosity AGN have the potential to deliver significant feedback to their environments.

  18. Fibrillary glomerulonephritis combined with chronic inflammatory demyelinating polyneuropathy

    PubMed Central

    Sung, Woo Kyung; Jeong, Jin Uk; Bang, Ki Tae; Shin, Jong Ho; Yoo, Ji Hyung; Kim, Nak Min; Park, Jun Hyung; Kim, Joo Heon

    2015-01-01

    A 58-yr-old man presented with leg edema and subacute weakness of his bilateral lower extremities. Urinary and serum immunoelectrophoresis revealed the presence of lambda-type Bence Jones proteins. He was ultimately diagnosed with monoclonal gammopathy of undetermined significance (MGUS). A renal biopsy specimen showed fibrillary glomerulonephritis (FGN), which was randomly arranged as 12–20 m nonbranching fibrils in the basement membranes. Immunofluorescence studies were negative for immunoglobulin (Ig)G, IgM, IgA, C3, and kappa light chains in the capillary walls and mesangial areas. A Congo red stain for amyloid was negative. Electromyography and nerve conduction velocity examinations results were compatible with the presence of demyelinating polyneuropathy. This case showed a rare combination of FGN, without Ig deposition, and MGUS combined with chronic inflammatory demyelinating polyneuropathy (CIDP). PMID:26484033

  19. Crescentic glomerulonephritis in a polar bear (Ursus maritimus).

    PubMed

    Baba, Hiroshi; Kudo, Tomoo; Makino, Yoshinori; Mochizuki, Yasumasa; Takagi, Takayo; Une, Yumi

    2013-11-01

    Spontaneous crescentic glomerulonephritis (CrGN) in animals has only been reported in dog and sheep. We report the pathological features of CrGN in a 17-year-old male polar bear that died due to renal failure. Histologically, the lesions were characterized by fibrocellular crescents, adhesion between Bowman's capsule and the glomerular capillary tuft and an increase in the mesangial matrix in glomeruli. The proliferating cells in the crescent were partly immunopositive for cytokeratin and intensely positive for vimentin, WT-1 and α-smooth muscle actin, suggesting they originated from parietal epithelial cells. Ultrastructually, thickening of the glomerular basement membrane and loss of epithelial cell foot processes were observed with electron-dense deposits.

  20. Fibrillary glomerulonephritis with hepatitis C viral infection and hypocomplementemia.

    PubMed

    Ray, Susan; Rouse, Kelly; Appis, Andrew; Novak, Robert; Haller, Nairmeen Awad

    2008-01-01

    Fibrillary glomerulonephritis (FGN) is a relatively rare cause of renal disease, found in only 0.6-1.5% of native renal biopsies. The pathogenesis of FGN is not well described, and very few associations with disease processes other than hepatitis C virus (HCV) have been made. We describe a case that provides evidence in support of the FGN-HCV association, as well as introduces the association of FGN-HCV and hypocomplementemia. The case is a 53-year-old African-American female demonstrating a classical presentation of FGN complicated by a concomitant HCV infection. Treating an HCV infection with alpha-interferon has been shown to result in subsequent improvement in the nephrotic syndrome and renal function. However, this patient is unique in that she is complicated with hypocomplementemia, creating a complex treatment situation.

  1. White-blue pyelocalyceal cyst with hydrotic glomerulonephritis.

    PubMed

    Chaurasia, Jai Kumar; Soni, Mayank; Ahmed, Murad; Naim, Mohammed

    2013-12-17

    A 5-month-old male infant presented with a 15 day history of distension of abdomen. On clinical examination, a soft lump was palpable in the left lumbar region. Radiological findings suggested an enlarged non-functional left kidney with ureteropelvic adhesive obstruction. The left renal mass was excised and submitted for histopathological examination. The excised renal mass was cystic with its wall partly white and partly blue. Gross and histopathological findings were diagnostic of a white-blue pyelocalyceal cyst with hydrotic glomerulonephritis. This entity needs to be differentiated from a large number of other cystic diseases of the kidney. Intrauterine screening and diagnosis may be significant for a possible early intrauterine uro-laparoscopic recanalisation of the pyeloureteral obstruction to save the affected kidney.

  2. Spectral Energy Distributions of Quasars and AGN

    NASA Astrophysics Data System (ADS)

    Wilkes, B.

    2004-06-01

    Active Galactic Nuclei (AGN) are multiwavelength emitters. To have any hope of understanding them, or even to determine their energy output, we must observe them in multiple wavebands using many telescopes. I will review what we have learned from broad-band observations of relatively bright, low-redshift AGN over the past ˜ 15 years. AGN can be found at all wavelengths but each provides a different view of the intrinsic population, often with little overlap between samples selected in different wavebands. I look forward to the full view of the intrinsic population which we will obtain over the next few years with surveys using today's new, sensitive observatories. These surveys are already finding enough new and different AGN candidates to pose the question ``What IS an AGN?".

  3. The BAT AGN Spectroscopic Survey (BASS)

    NASA Astrophysics Data System (ADS)

    Koss, Michael; Trakhtenbrot, Benny; Ricci, Claudio; Lamperti, Isabella; Oh, Kyuseok; Berney, Simon; Schawinski, Kevin; Balokovic, Mislav; Baronchelli, Linda; Gehrels, Neil; Stern, Daniel; Mushotzky, Richard; Veilleux, Sylvain; Ueda, Yoshihiro; Crenshaw, D. Michael; Harrison, Fiona; Fischer, Travis C.; Treister, Ezequiel; BASS Team; Swift BAT Team

    2017-01-01

    We present the Swift BAT AGN Spectroscopic Survey (BASS) and discus the first four papers. The catalog represents an unprecedented census of hard-X-ray selected AGN in the local universe, with ~90% of sources at z<0.2. Starting from an all-sky catalog of AGN detected based on their 14-195 keV flux from the 70-month Swift/BAT catalog, we analyze a total of 1279 optical spectra, taken from twelve dierent telescopes, for a total of 642 spectra of unique AGN. We present the absorption and emission line measurements as well as black hole masses and accretion rates for the majority of obscured and un-obscured AGN (473), representing more than a factor of 10 increase from past studies. Consistent with previous surveys, we find an increase in the fraction of un-obscured (type 1) AGN, as measured from broad Hbeta and Halpha, with increasing 14-195 keV and 2-10 keV luminosity. We find the FWHM of the emission lines to show broad agreement with the X-ray obscuration measurements. Compared to narrow line AGN in the SDSS, the X-ray selected AGN in our sample with emission lines have a larger fraction of dustier galaxies suggesting these types of galaxies are missed in optical AGN surveys using emission line diagnostics. Additionally, we discuss follow-on efforts to study the variation of [OIII] to Xray measurements, a new method to measure accretion rates from using line ratios, a sample of 100 AGN observed with NIR spectroscopy, and an effort to measure the accretion rates and obscuration with merger stage in a subsample of mergers.

  4. Patterns of glomerulonephritis in Zimbabwe: survey of disease characterised by nephrotic proteinuria.

    PubMed

    Seggie, J; Davies, P G; Ninin, D; Henry, J

    1984-01-01

    Ninety-eight Zimbabweans with glomerulonephritis characterised by nephrotic proteinuria were studied. There was no evidence to implicate Schistosoma mansoni or S. haemotobium in the aetiology, although schistosomiasis was diagnosed in 54 patients in the series. Similarly, Plasmodium malariae proved unimportant as a cause of the nephrotic syndrome, only one patient showing focal segmental glomerulosclerosis which was associated with subclinical quartan malarial infection. Nevertheless, infections were shown to play a major role in the genesis of glomerulonephritis which was associated with beta-haemolytic streptococcal, hepatitis B and syphilitic infection in 45 patients in the series. The major patterns of disease in childhood proved to be membranous glomerulopathy associated with hepatitis B antigenaemia. In young adults post-streptococcal proliferative glomerulonephritis constituted the commonest disease pattern. In older adult patients a miscellany of primary and secondary glomerulonephritides was encountered but proliferative glomerulonephritis, which was both idiopathic and streptococcus-related, predominated.

  5. Necrotizing ANCA-Positive Glomerulonephritis Secondary to Culture-Negative Endocarditis

    PubMed Central

    Van Haare Heijmeijer, Sophie; Wilmes, Dunja; Aydin, Selda; Clerckx, Caroline; Labriola, Laura

    2015-01-01

    Infective endocarditis (IE) and small-vessel vasculitis may have similar clinical features, including glomerulonephritis. Furthermore the association between IE and ANCA positivity is well documented, making differential diagnosis between IE- and ANCA-associated vasculitis particularly difficult, especially in case of culture-negative IE. We report on one patient with glomerulonephritis secondary to culture-negative IE caused by Bartonella henselae which illustrates this diagnostic difficulty. PMID:26819786

  6. Canadian Society of Nephrology Commentary on the 2012 KDIGO clinical practice guideline for glomerulonephritis: management of glomerulonephritis in adults.

    PubMed

    Cybulsky, Andrey V; Walsh, Michael; Knoll, Greg; Hladunewich, Michelle; Bargman, Joanne; Reich, Heather; Humar, Atul; Samuel, Susan; Bitzan, Martin; Zappitelli, Michael; Dart, Allison; Mammen, Cherry; Pinsk, Maury; Muirhead, Norman

    2014-03-01

    The KDIGO (Kidney Disease: Improving Global Outcomes) clinical practice guideline for management of glomerulonephritis was recently released. The Canadian Society of Nephrology convened a working group to review the recommendations and comment on their relevancy and applicability to the Canadian context. A subgroup of adult nephrologists reviewed the guideline statements for management of glomerular disease in adults and agreed with most of the guideline statements developed by KDIGO. This commentary highlights areas for which there is lack of evidence and areas in need of translation of evidence into clinical practice. Areas of controversy or uncertainty, including the choice of second-line agents, are discussed in more detail. Existing practice variation also is addressed. The relevance of treatment recommendations to the Canadian practitioner is discussed.

  7. The 60-month all-sky BAT Survey of AGN and the Anisotropy of Nearby AGN

    SciTech Connect

    Ajello, M.; Alexander, D.M.; Greiner, J.; Madejski, G.M.; Gehrels, N.; Burlon, D.; /Garching, Max Planck Inst., MPE

    2012-04-02

    Surveys above 10 keV represent one of the the best resources to provide an unbiased census of the population of Active Galactic Nuclei (AGN). We present the results of 60 months of observation of the hard X-ray sky with Swift/BAT. In this timeframe, BAT detected (in the 15-55 keV band) 720 sources in an all-sky survey of which 428 are associated with AGN, most of which are nearby. Our sample has negligible incompleteness and statistics a factor of {approx}2 larger over similarly complete sets of AGN. Our sample contains (at least) 15 bona-fide Compton-thick AGN and 3 likely candidates. Compton-thick AGN represent a {approx}5% of AGN samples detected above 15 keV. We use the BAT dataset to refine the determination of the LogN-LogS of AGN which is extremely important, now that NuSTAR prepares for launch, towards assessing the AGN contribution to the cosmic X-ray background. We show that the LogN-LogS of AGN selected above 10 keV is now established to a {approx}10% precision. We derive the luminosity function of Compton-thick AGN and measure a space density of 7.9{sub -2.9}{sup +4.1} x 10{sup -5} Mpc{sup -3} for objects with a de-absorbed luminosity larger than 2 x 10{sup 42} erg s{sup -1}. As the BAT AGN are all mostly local, they allow us to investigate the spatial distribution of AGN in the nearby Universe regardless of absorption. We find concentrations of AGN that coincide spatially with the largest congregations of matter in the local ({le} 85 Mpc) Universe. There is some evidence that the fraction of Seyfert 2 objects is larger than average in the direction of these dense regions.

  8. Spitzer's contribution to the AGN population

    NASA Astrophysics Data System (ADS)

    Donley, Jennifer Lynn

    2009-06-01

    Using large multiwavelength datasets, we study obscured AGN in the distant universe that have been missed via traditional selection techniques (e.g. UV/ optical/X-ray). To do so, we take particular advantage of the mid-IR, which is minimally affected by obscuration. We first select as AGN candidates those objects whose radio emission is significantly brighter, relative to the mid-IR, than would be predicted by the well known radio/infrared correlation, indicating that the radio emission originates in the central engine. We find that of the 27 such sources identified in the CDF-N, 60% lack solid X-ray detections and 25% lack even 2s X-ray emission. The absorbing columns of the faint X-ray-detected objects indicate that they are obscured but unlikely to be Compton thick, whereas the radio-excess AGN which are X-ray non-detected are Compton-thick candidates. We similarly use the infrared emission to select IRAC (3.6-8.0 mm) power-law AGN. In these luminous AGN, the hot dust emission from the AGN fills in the gap in a galaxy's SED between the 1.6 mm stellar bump and the long-wavelength dust emission feature. While sources selected in this way are more luminous than the radio-excess AGN, we find a similar X-ray detection fraction. Of the 62 power- law galaxies in the CDF-N, only 55% are detected in the X-ray, and 15% lack evidence for even weak 2s X-ray emission. A study of their X-ray properties indicates that ~ 75% are obscured. Finally, we test IRAC color-color and infrared-excess selection criteria. We find that while these selection techniques identify a number of obscured AGN, they may also select a significant number of star-forming galaxies. By combining only the secure AGN candidates selected via all methods discussed above, we estimate that the addition of Spitzer-selected AGN candidates to the deepest X-ray selected AGN samples directly increases the number of known AGN by 54-77%, and implies a total increase to the number of AGN of 71-94%.

  9. CD11b is protective in complement-mediated immune complex glomerulonephritis.

    PubMed

    Alexander, Jessy J; Chaves, Lee D; Chang, Anthony; Jacob, Alexander; Ritchie, Maria; Quigg, Richard J

    2015-05-01

    In chronic serum sickness, glomerular immune complexes form, yet C57BL/6 mice do not develop glomerulonephritis unless complement factor H (CfH) is absent, indicating the relevance of complement regulation. Complement receptor 3 (CD11b) and Fcγ receptors on leukocytes, and CfH on platelets, can bind immune complexes. Here we induced immune complex-mediated glomerulonephritis in CfH(-/-) mice chimeric for wild-type, CfH(-/-), CD11b(-/-), or FcRγ(-/-) bone marrow stem cells. Glomerulonephritis was worse in CD11b(-/-) chimeras compared with all others, whereas disease in FcRγ(-/-) and wild-type chimeras was comparable. Disease tracked strongly with humoral immune responses, but not glomerular immune complex deposits. Interstitial inflammation with M1 macrophages strongly correlated with glomerulonephritis scores. CD11b(-/-) chimeras had significantly more M1 macrophages and CD4(+) T cells. The renal dendritic cell populations originating from bone marrow-derived CD11c(+) cells were similar in all experimental groups. CD11b(+) cells bearing colony-stimulating factor 1 receptor were present in kidneys, including CD11b(-/-) chimeras; these cells correlated negatively with glomerulonephritis scores. Thus, experimental immune complex-mediated glomerulonephritis is associated with accumulation of M1 macrophages and CD4(+) T cells in kidneys and functional renal insufficiency. Hence, CD11b on mononuclear cells is instrumental in generating an anti-inflammatory response in the inflamed kidney.

  10. AGN Accretion Physics: Insights from K2

    NASA Astrophysics Data System (ADS)

    Vogeley, Michael

    We propose to use Kepler K2 mission observations of 1800 supermassive black holes at the centers of galaxies (Active Galactic Nuclei; AGN) to test models for accretion physics, to study the relationship between variability and other AGN properties such as accretion rate, and to guide methods for detecting and classifying AGN in future time-domain surveys. AGN exhibit optical brightness fluctuations on timescales from below an hour up to many years. These fluctuations are determined by the physics of accretion of matter onto black holes from their galactic environment. By observing variability on timescales down to below an hour, Kepler probes the accretion region on length scales that are too small to be directly imaged using conventional telescopes. These data allow us to test competing models for accretion physics that make different predictions for the statistics of variability. Our previous work provides strong evidence that models of AGN variability that work on long timescale data are not adequate to describe the full range of fluctuation timescales probed by Kepler. We will analyze the light curves of 1800 AGN that have been monitored by Kepler during recent and ongoing K2 campaigns. These objects span a large range of luminosity and AGN type, thus allowing study of the relationship between variability and other physical properties. We will characterize the statistics of AGN variability using state-of-the-art methods of time series analysis that are appropriate for quantifying the stochastic behavior of AGN. This analysis builds on our previous work in which we developed and tested new analysis software that extracts the full information content of these light curves and will enable several key outcomes: (1) Measurement of the relationship between types of AGN and their variability. (2) Tests for dependence of variability on accretion rate. (3) Investigation of changes in variability behavior that point to changes in the mode of accretion. (4) Correlations

  11. [The interaction of atrial natriuretic peptide with other bioregulators of kidney function in chronic glomerulonephritis in children].

    PubMed

    Kucherenko, A G; Markov, Kh M; Zokirov, N Z; Naumova, V I

    1994-01-01

    A study was made of renin-angiotensin-aldosterone system activity and plasmic concentrations of atrial natriuretic peptide (NUP) as well as antidiuretic hormone in children with primary glomerulonephritis. A close relationship was established of these parameters in regulation of water-salt homeostasis. The above systems are involved in pathogenesis of childhood glomerulonephritis. This finding should be considered in development of pathogenetically validated therapy of glomerulonephritis, including introduction of synthetic NUP.

  12. Resolving AGN with PanSTARRS transients

    NASA Astrophysics Data System (ADS)

    Lawrence, Andy

    2012-10-01

    With PanSTARRS we have discovered a new class of slow, blue nuclear transients which we believe to be rare examples of background AGN microlensed by stars in foreground galaxies, amplified by a factor of 10--100. The background AGN should be somewhat resolved by the foreground lens, providing a unique new diagnostic of AGN size and structure - the UV, optical, IR, BLR, and X-ray regions should have differing evolutions during the event. This proposal is a first step towards understanding the structure of the X-ray source : testing the microlensing hypothesis, characterising the SED, and establishing the first two epochs in an expected gradual decline.

  13. Probing Agn Accretion Physics With Kepler

    NASA Astrophysics Data System (ADS)

    Vogeley, Michael

    We propose to use Kepler observations of a sample of ~100 supermassive black holes at the centers of galaxies (Active Galactic Nuclei; AGN) to test models for accretion physics, to study the relationship between variability and other AGN properties, and to guide methods for detecting and classifying AGN in future time-domain surveys. AGN exhibit optical brightness fluctuations on timescales from below an hour up to many years. These fluctuations are determined by the physics of accretion of matter onto black holes from their galactic environment. By observing variability on timescales down to below an hour, Kepler probes the accretion region on length scales that are too small to be directly imaged using conventional telescopes. Data from this unique time- domain telescope now allow us to test competing models for accretion physics that make different predictions for the statistics of variability. Preliminary work provides strong evidence that models of AGN variability that work on long timescale data are not adequate to describe the full range of fluctuation timescales probed by Kepler. We will analyze the light curves of Kepler AGN that span a large range of luminosity and AGN type, thus allowing study of the relationship between variability and other physical properties. Using methods developed and tested by the Kepler team, we will perform custom post-processing of these light curves to remove known systematics. Statistical analyses of the AGN light curves will include estimation of the Structure Function, which quantifies the correlations of brightness fluctuations, and maximum likelihood light curve reconstruction. Competing models for the stochastic behavior of AGN will be tested to evaluate which models best describe variability of AGN over the full range of timescales probed by Kepler. Correlations between the stochastic model parameters and physical parameters will provide new methods for classification of AGN from their variability and aid in

  14. Toward a Unified AGN Structure

    NASA Technical Reports Server (NTRS)

    Kazanas, Demosthenes; Fukumura, Keigo; Shrader, Chris; Behar, Ehud; Contopoulosa, Ioannis

    2012-01-01

    We present a unified model for the structure and appearance of accretion powered sources across their entire luminosity range from galactic X-ray binaries (XRB) to luminous quasars, with emphasis on AG N and their phenomenology. Central to this model is the notion of MHD winds launched by the accretion disks that power these objects. These winds provide the matter that manifests as blueshifted absorption features in the UV and X-ray spectra of a large fraction of these sources; furthermore, their density distribution in the poloidal plane determines their "appearance" (i.e. the column and velocity structure of these absorption features and the obscuration of the continuum source) as a function of the observer inclination angle (a feature to which INTEGRAL has made significant contributions). This work focuses on just the broadest characteristics of these objects; nonetheless, it provides scaling laws that allow one to reproduce within this model the properties of objects extending in luminosity from luminous quasars to XRBs. Our general conclusion is that the AGN phenomenology can be accounted for in terms of three parameters: The wind maSS flux in units of the Eddington value, m(dot), the observers' inclination angle Theta and the logarithmic slope between the 0/UV and X-ray fluxes alpha(sub ox); however because of a correlation between alpha(sub ox) and UV luminosity the number of significant parameters is two. The AGN correlations implied by this model appear to extend to and consistent with the XRB phenomenology, suggesting the presence of a truly unified underlying structure for accretion powered sources.

  15. The Evolution of Obscuration in AGN

    NASA Astrophysics Data System (ADS)

    Treister, Ezequiel; Urry, M.; Virani, S.

    2006-09-01

    One fundamental ingredient in our understanding of the AGN population is the ratio of obscured to unobscured AGN and whether this ratio depends on other parameters like intrinsic luminosity or redshift. Observationally, deep X-ray surveys found that the obscured AGN fraction depends on luminosity. However, the dependence on redshift is less clear. In this work, we constructed the largest sample to date of AGN selected in hard X-rays, containing a total of 1229 sources, 631 of them obscured, with a high spectroscopic completeness in order to study the possible dependence of the fraction of obscured sources with redshift and/or luminosity. We confirm that this fraction decreases with increasing luminosity as previously reported and found that at the same time it increases with increasing redshift. This is the first time that this evolution is significantly detected using only optical spectroscopy to separate obscured and unobscured AGN. Additionally, we use the spectral shape and intensity of the X-ray background as a separate constraint on the evolution of the obscured AGN fraction finding consistent results. This result can be interpreted as an evolution in the location of the obscuration, from the central parsec-scale region (the torus) at low redshift to kiloparsec scales (the host galaxy) at high redshift, as it is known that most galaxies contained more dust in the past. Using these results, we calculate the integrated bolometric AGN emission finding it to be at most 5% of the total extragalactic light. Hence, while AGN contribute most of the light at X-ray wavelengths, they constitute only a small fraction of the integrated extragalactic light. We thank the support of the Centro de Astrof\\'{\\i}sica FONDAP and from NASA/{\\it INTEGRAL} grant NNG05GM79G.

  16. Molecular mimicry in pauci-immune focal necrotizing glomerulonephritis

    PubMed Central

    Kain, Renate; Exner, Markus; Brandes, Ricarda; Ziebermayr, Reinhard; Cunningham, Dawn; Alderson, Carol A; Davidovits, Agnes; Raab, Ingrid; Jahn, Renate; Ashour, Oliver; Spitzauer, Susanne; Sunder-Plassmann, Gere; Fukuda, Minoru; Klemm, Per; Rees, Andrew J; Kerjaschki, Dontscho

    2009-01-01

    Pauci-immune focal necrotizing glomerulonephritis (FNGN) is a severe inflammatory disease associated with autoantibodies to neutrophil cytoplasmic antigens (ANCA). Here we characterize autoantibodies to lysosomal membrane protein-2 (LAMP-2) and show that they are a new ANCA subtype present in almost all individuals with FNGN. Consequently, its prevalence is nearly twice that of the classical ANCAs that recognize myeloperoxidase or proteinase-3. Furthermore, antibodies to LAMP-2 cause pauci-immune FNGN when injected into rats, and a monoclonal antibody to human LAMP-2 (H4B4) induces apoptosis of human microvascular endothelium in vitro. The autoantibodies in individuals with pauci-immune FNGN commonly recognize a human LAMP-2 epitope (designated P41–49) with 100% homology to the bacterial adhesin FimH, with which they cross-react. Rats immunized with FimH develop pauci-immune FNGN and also develop antibodies to rat and human LAMP-2. Finally, we show that infections with fimbriated pathogens are common before the onset of FNGN. Thus, FimH-triggered autoimmunity to LAMP-2 provides a previously undescribed clinically relevant molecular mechanism for the development of pauci-immune FNGN. PMID:18836458

  17. [Rapidly progressive glomerulonephritis in a 68-year-old man].

    PubMed

    Rubio, E; Acevedo, M

    2004-01-01

    A 68-year-old male with macroscopic hematuria and constitutional symptoms as fever and weight loss. There was nothing interesting in the anamnesis or in the physical exploration. The laboratory test had an elevation of creatinine of 4 mg/dL and ten days before it had been 1.4 mg/dL. In the urine analysis: proteinuria of 1.5 G/24 h, and hematuria. On the second day we made a renal biopsy where we could seen segmental glomerular necrosis and crescent fromation in 80% of the glomeruli. In the immune study c-ANCA anti-PR3 was positive. In the complementary studies we didn't find other organs affected. With the diagnosis of pauci-immune glomerulonephritis limited to the kidney we began treatment with corticosteroids and cyclophosphamide. As the renal function was severely affected the patient needed one dialysis session. We began with 1 g intravenous methylprednisolone daily for 3 days followed by oral prednisone 60 mg daily tapering to 10 mg daily by 3 months. This was combined with 150 mg oral cyclophosphamide daily. Seven plasma exchanges were performed. At the beginning of treatment creatinine was 7 mg/dL, it was decreasing rapidly and three week after cretinine was 3 mg/Dl and he was asymptomatic. One year after treatment, creatinine is 1.4 mg/dL and the urine analysis is normal, C-ANCA are negative.

  18. Clinicopathological insights into lupus glomerulonephritis in Japanese and Asians.

    PubMed

    Yokoyama, Hitoshi; Okuyama, Hiroshi; Yamaya, Hideki

    2011-06-01

    Lupus nephritis comprises a spectrum of glomerular, vascular, and tubulointerstitial lesions, which has significant racial variation in severity and manifestations. The current classification (ISN/RPS 2003) has been improved successfully for the categorization of lupus glomerulonephritis (LGN). On the basis of this classification, 480 Japanese cases revealed the following distribution: class I 3%, class II 16%, class III 13%, class IV-S 11%, class IV-G 41%, class V 16%, and class VI 1%. Class IV-G with chronicity tended to have the worst renal outcome. Nephrotic syndrome was a more frequent complication in class IV-S (50%), class IV-G (72%), and class V (56%), with poor renal and actuarial outcomes. With regard to therapy, treatment options including glucocorticoids alone or combined with antimetabolites (azathioprine, mizoribine, mycophenolate mofetil), calcineurin inhibitors (cyclosporine A, tacrolimus), or alkylating agents (intravenous cyclophosphamide injection) improved the outcome of LGN; however, there is no high-grade clinical evidence from Japan. Further studies are needed to resolve the clinicopathological problems of LGN, especially IV-S, IV-G, and pure membranous lupus nephritis in Japanese patients.

  19. Mycophenolate Mofetil (MMF) Efficacy in Glomerulonephritis (GN), a Retrospective Analysis.

    PubMed

    Huraib, Sameer O; Qureshi, Junaid I; Quadri, Khaja Hm; Al Flaiw, Ahmed; Al Ghamdi, Ghormullah; Jumani, Abdulqadir; Al Hejaili, Fayez; Raza, Hammad; Al Johani, Abdulaziz; Al-Katheri, Abdulmalik; Al-Khader, Abdullah A

    2005-01-01

    Mycophenolate Mofetil MMF has been widely used in post-transplant immunosuppression. Its role is emerging in GN. MMF demonstrated promising results compared with cyclosphosphamide in stage IV lupus nephritis, in a recently published trial. It has been found to have a wide safety profile, with mostly gastroinetestinal side effects, which can be avoided through titration. Its action is through inhibition of the enzyme IMDPH (ionosine monophosphate dehydrogenase), leading to purine antagonism and inhibition of lymphocytes. We were aiming to demonstrate the efficacy of MMF in our GN population. In this study, we reviewed 17 patients who received MMF (dose - 1 gm po bid) for the past year. They were only included if it was given for the management of resistant primary glomerulonephritis. Complete remission has been defined as proteinuria of less than 0.5 g/day and partial remission as a reduction of proteinuria 50% of starting MMF therapy; all 17 MMF therapy patients uniformly achieved good BP ((29%) achieved complete remission and this group consisted of 1 membranous GN, 2 lupus GN (type IV and membranous), one FSGS and one with MPGN. Four of 17 (23%) were non-responders to therapy. This group articles.aspx? id=41 to side effects. We conclude that the MMF appears to be an effective alternate treatment modality in resistant membranous GN, lupus nephritis (type IV and V) and possibly MPGN, and to a lesser extent in resistant FSGS. Further prospective data may demonstrate the efficacy of MMF in GN.

  20. A New Catalog of Type 1 AGNs and its Implications on the AGN Unified Model

    NASA Astrophysics Data System (ADS)

    Oh, Kyuseok; Yi, Sukyoung K.; Schawinski, Kevin; Koss, Michael; Trakhtenbrot, Benny; Soto, Kurt

    2015-07-01

    We have recently identified a substantial number of type 1 active galactic nuclei (AGNs) featuring weak broad-line regions (BLRs) at z\\lt 0.2 from detailed analysis of galaxy spectra in the Sloan Digital Sky Survey Data Release 7. These objects predominantly show a stellar continuum but also a broad Hα emission line, indicating the presence of a low-luminosity AGN oriented so that we are viewing the central engine directly without significant obscuration. These accreting black holes have previously eluded detection due to their weak nature. The newly discovered BLR AGNs have increased the number of known type 1 AGNs by 49%. Some of these new BLR AGNs were detected with the Chandra X-ray Observatory, and their X-ray properties confirm that they are indeed type 1 AGNs. Based on our new and more complete catalog of type 1 AGNs, we derived the type 1 fraction of AGNs as a function of [O iii] λ 5007 emission luminosity and explored the possible dilution effect on obscured AGNs due to star formation. The new type 1 AGN fraction shows much more complex behavior with respect to black hole mass and bolometric luminosity than has been suggested previously by the existing receding torus model. The type 1 AGN fraction is sensitive to both of these factors, and there seems to be a sweet spot (ridge) in the diagram of black hole mass and bolometric luminosity. Furthermore, we present the possibility that the Eddington ratio plays a role in determining opening angles.

  1. First Detections of Compact AGN-triggered Radio Cores in RQ AGNs in the ECDFS

    NASA Astrophysics Data System (ADS)

    Prandoni, I.; Maini, A.; Norris, R. P.; Giovannini, G.; Spitler, L. R.

    2016-08-01

    The mechanism triggering the radio emission in Radio-Quiet (RQ) Active Galactic Nuclei (AGN), found to be a relevant component of the faint radio population in deep fields, is hotly debated. Most RQ AGNs are unresolved or barely resolved at a few arcsec scale, comparable to the host galaxy size. RQ AGNs have also been found to share many properties with Star Forming Galaxies (SFG). They have similar radio luminosities and similar optical- /infrared-to-radio flux ratios. Their radio luminosity functions show similar evolutionary trends, and their host galaxies have similar colours, optical morphologies and stellar masses. For all these reasons it was concluded that the radio emission in such RQ AGNs is mainly triggered by star formation (SF). However in the local Universe (z<0.5) it is well known that both AGN and SF processes can contribute to the total radio emission in RQ AGNs (see e.g., Seyfert 2 galaxies), and there is growing evidence that composite SF/AGN systems are common at mid to high redshift (z>1-2). We used the Australian Long Baseline Array to observe a number of RQ AGNs in the Extended Chandra Deep Field South (ECDFS), and we detected compact, high-surface-brightness radio cores in some of them. Our pilot study shows that at least some of the sources classified as radio quiet contain an AGN that can contribute significantly (~50% or more) to the total radio emission. This is a first direct evidence of the presence of such AGN-triggered radio emission in RQ AGNs at cosmological redshifts.

  2. AGN Absorption Linked to Host Galaxies

    NASA Astrophysics Data System (ADS)

    Juneau, Stéphanie

    2014-07-01

    Multiwavelength identification of AGN is crucial not only to obtain a more complete census, but also to learn about the physical state of the nuclear activity (obscuration, efficiency, etc.). A panchromatic strategy plays an especially important role when the host galaxies are star-forming. Selecting far-Infrared galaxies at 0.3AGN tracers in the X-ray, optical spectra, mid-infrared, and radio regimes, we found a twice higher AGN fraction than previous studies, thanks to the combined AGN identification methods and in particular the recent Mass-Excitation (MEx) diagnostic diagram. We furthermore find an intriguing relation between AGN X-ray absorption and the specific star formation rate (sSFR) of the host galaxies, indicating a physical link between X-ray absorption and either the gas fraction or the gas geometry in the hosts. These findings have implications for our current understanding of both the AGN unification model and the nature of the black hole-galaxy connection.

  3. Obscured AGN Accretion Across Cosmic Time

    NASA Astrophysics Data System (ADS)

    Coil, Alison

    We propose to combine data from XMM-Newton, the Chandra X-ray Observatory, and the Spitzer Space Telescope with ground-based optical spectroscopy from Keck and Magellan to measure the relationship between AGN obscuration and accretion activity over the bulk of cosmic history. This work will establish the prominence of both obscured and unobscured growth phases of black holes and shed light on the processes that trigger and fuel AGN as a function of time. We will complete three complementary projects that focus on a) understanding the completeness and biases of AGN selection at mid-IR versus X-ray wavelengths, b) tracing optical obscuration as a function of luminosity and redshift, and c) measuring the distribution and evolution of X-ray absorption of AGN. We will undertake a study of AGN demographics comparing selection techniques at three different wavelengths: mid-IR selection using data from the Spitzer Space Telescope, X- ray selection using data from the XMM-Newton and Chandra satellites, and broad-line optical selection using PRIMUS spectroscopy. We will determine the overlap and uniqueness of samples created using each method, to quantify the completeness and biases inherent in AGN selection at each wavelength. This will lead to a constraint on the fraction of heavily obscured, Compton-thick AGN to z~1. To study the optical obscuration of AGN, we will use three recently-completed spectroscopic surveys -- PRIMUS, DEEP2, and our own Keck program -- to robustly determine the ratio of unobscured (broad-line) to obscured (non--broad-line) X-ray selected AGN as a function of luminosity from z~0.2 to z~3. We will utilize the well- understood selection functions and characterize the AGN completeness of each survey as a function of redshift, magnitude, and obscuration properties. This will allow us to correct for a variety of observational effects to measure the underlying joint redshift- and luminosity-dependence of optical obscuration, which has direct implications

  4. AGN multi-wavelength identification and host galaxy properties

    NASA Astrophysics Data System (ADS)

    Azadi, Mojegan; Coil, Alison L.; MOSDEF Team; PRIMUS Team

    2017-01-01

    I present results on AGN identification, selection biases, and host galaxy properties at z~2.3 and results on the relation between AGN accretion and star formation activity at z~0.8. In the MOSDEF survey, with a sample of X-ray, IR, and optically selected AGN at z~2.3, using rest-frame optical spectra obtained with the Keck/MOSFIRE instrument, I find clear selection biases in identifying AGN at these wavelengths. There is a strong bias against identifying AGN at any wavelength in low mass galaxies, and an additional bias against identifying IR AGN in the most massive galaxies. While AGN hosts span a wide range of SFR, IR AGN are mainly in less dusty galaxies with relatively higher SFR and optical AGN are in dusty galaxies with relatively lower SFR in our sample. X-ray AGN selection does not display a bias with host SFR. I also consider the relation between the growth of galaxies and their SMBHs using a large sample of X-ray AGN in the PRIMUS survey. I do not find a significant correlation between SFR and AGN instantaneous luminosity. However, I find a weak but significant correlation between the average luminosity of AGN and SFR, which likely reflects that AGN luminosities vary on shorter timescales than host galaxies SFR. My results indicate that AGN are also often hosted by quiescent galaxies, and within both the star-forming and quiescent galaxy populations the probability of hosting an AGN is a power-law distribution as a function of specific accretion rate. However, at a given stellar mass, I find that a star-forming galaxy is ~2-3 times more likely than a quiescent galaxy to host an AGN of a given specific accretion rate. The probability of a galaxy hosting an AGN is constant across the main sequence of star formation, while in quiescent galaxies increases with SFR.

  5. The Angular Clustering of WISE-Selected AGN: Different Haloes for Obscured and Unobscured AGN

    NASA Astrophysics Data System (ADS)

    Yan, Lin

    2015-08-01

    We calculate the angular correlation function for a sample of 170,000 AGN extracted from the Wide-field Infrared Survey Explorer (WISE) catalog, selected to have red mid-IR colors (W1 - W2 > 0.8) and 4.6 micron flux densities brighter than 0.14 mJy). The sample is expected to be >90% reliable at identifying AGN, and to have a mean redshift of z=1.1. In total, the angular clustering of WISE-AGN is roughly similar to that of optical AGN. We cross-match these objects with the photometric SDSS catalog and distinguish obscured sources with (r - W2) > 6 from bluer, unobscured AGN. Obscured sources present a higher clustering signal than unobscured sources. Since the host galaxy morphologies of obscured AGN are not typical red sequence elliptical galaxies and show disks in many cases, it is unlikely that the increased clustering strength of the obscured population is driven by a host galaxy segregation bias. By using relatively complete redshift distributions from the COSMOS survey, we find obscured sources at mean redshift z=0.9 have a bias of b = 2.9 \\pm 0.6 and are hosted in dark matter halos with a typical mass of log(M/M_odot)~13.5. In contrast, unobscured AGN at z~1.1 have a bias of b = 1.6 \\pm 0.6 and inhabit halos of log(M/M_odot)~12.4. These findings suggest that obscured AGN inhabit denser environments than unobscured AGN, and are difficult to reconcile with the simplest AGN unification models, where obscuration is driven solely by orientation.

  6. The ROSAT/NVSS AGN sample

    NASA Astrophysics Data System (ADS)

    Paronyan, Gurgen M.; Abrahamyan, Hayk V.; Harutyunyan, Gohar S.; Mickaelian, Areg M.

    2014-07-01

    We attempt to create an X-ray/radio AGN catalog and make its multiwavelength studies. ROSAT Bright Source Catalogue (BSC) contains 18,806 and ROSAT Faint Source Catalogue (FSC), 105,922 X-ray sources giving the total number of ROSAT X-ray sources 124,727 (one source is listed twice). On the other hand, NVSS radio catalogue contains 1,773,484 sources. Taking into account that X-ray sources contain AGN, bright stars and galaxies, clusters, white dwarfs (WD), cataclysmic variables (CV), etc., the cross-identification with radio catalogue may distinguish the extragalactic sources. We have cross-correlated ROSAT catalogs with NVSS one with a search radius 30 arcsec. 9,193 associations have been found. To distinguish AGN from the normal bright galaxies and clusters, Veron-Cetty & Veron AGN catalog (v.13, 2010; VCV-13) containing 168,940 objects have been used. A cross-correlation of the 9,193 ROSAT/NVSS sources with the VCV-13 with a search radius 30 arcsec resulted in 3,094 associations. Thus we are left with more 6,099 X-ray/radio sources without an optical identification. Brighter objects are normal bright galaxies, while we believe that all faint ones are candidate AGN with some contamination of distant clusters. SDSS spectroscopic survey allows us classify objects by activity types, and a number of our candidate AGN is found to be present in SDSS. We attempt to find connections between the fluxes in different wavelength ranges, which will allow us to confirm AGN and blazars candidates and in some cases find new ones.

  7. Do food antigens play a role in the pathogenesis of some cases of human glomerulonephritis?

    PubMed Central

    van der Woude, F J; Hoedemaeker, P J; van der Giessen, M; de Graeff, P A; de Monchy, J; The, T H; van der Hem, G K

    1983-01-01

    Circulating immune complexes after a test meal were measured with three methods (PEG precipitation, Clq-ELISA and the indirect granulocyte phagocytosis test) in 10 controls, two symptomless persons with selective IgA deficiency and 14 patients with various types of glomerulonephritis, of which two patients (with idiopathic membranous glomerulopathy and local focal glomerulonephritis) also had selective IgA deficiency. The PEG and Clq-ELISA test did not show significant differences between the groups. In the two symptomless persons with selective IgA deficiency and in the patient with local focal glomerulonephritis and selective IgA deficiency the indirect granulocyte phagocytosis test (IGFT) showed a reproducible increase in IgG, IgM and complement containing immune complexes. In the last patient multiple food antigens were probably responsible for this phenomenon, a rapid amelioration of kidney function could be induced three times by giving an antigen free diet. PMID:6851247

  8. Membranous glomerulonephritis in the Iberian lynx (Lynx pardinus).

    PubMed

    Jiménez, Angeles; Sánchez, Belén; Pérez Alenza, Dolores; García, Pilar; López, Jose Vicente; Rodriguez, Alejandro; Muñoz, Alvaro; Martínez, Fernando; Vargas, Astrid; Peña, Laura

    2008-01-15

    The Iberian lynx is the most endangered felid species in the world, confined nowadays to two isolated metapopulations in the southwest of Spain, where less than 200 individuals survive. Little is known about the diseases that affect these animals in the wild or in captivity. Kidney samples from necropsies of 27 Iberian lynxes, wild and captive, were examined by histopathology, immunohistochemistry (IgG, IgM, IgA, laminin, type IV collagen, and fibronectin), electron microscopy (n=8) and immunogold labelling for IgM, IgG and IgA in one case, in order to characterize the glomerulopathy prevalent in this species. Urinalyses from records were available for 9 of the necropsied animals and blood and urine samples from 23 free ranging and captive Iberian lynxes were prospectively obtained in order to evaluate the renal function of the living population. A focal, diffuse membranous glomerulonephritis (MGN) that progressed with age was diagnosed in all but one of the animals in different stages not associated to concurrently known infectious diseases. Positive immunoexpression of IgM and IgG was observed in the glomerular capillary basement membranes and intramembranous electron-dense deposits, compatible with immune complexes (ICs) were seen with electron microscopy. The immunogold labelling was also positive for IgM and IgG in the electron-dense areas. The serum biochemistry and urinalyses also revealed signs of mild chronic kidney disease in 16 of the 23 animals evaluated. In conclusion, the membranous glomerulopathy affecting the Iberian lynx is a progressive disease of immune origin. We postulate a possible genetic predisposition towards the disease, enhanced by inbreeding and a possible connection to an immune-mediated systemic disease.

  9. Experimental immune complex-mediated glomerulonephritis in the nonhuman primate

    SciTech Connect

    Hebert, L.A.; Cosio, F.G.; Birmingham, D.J.; Mahan, J.D.; Sharma, H.M.; Smead, W.L.; Goel, R. )

    1991-01-01

    This study was undertaken to develop a model of immune complex (IC)-mediated glomerulonephritis (GN) in the nonhuman primate that could be used in subsequent studies to examine critically the role of the erythrocyte complement receptor (E-CR) in the pathogenesis of IC-mediated disease. Cynomolgus monkeys were chosen for study because they constitutively express E-CR levels that are either less than, equal to, or greater than that seen in normal man. After immunization with bovine gamma globulin (BGG), the GN induction protocol was begun in 10 cynomolgus by initiating daily i.v. administration of BGG in amounts sufficient to achieve or exceed antigen/antibody equivalence (assessed by the quantitative precipitin assay) for precipitating antibody present in the plasma volume. We found that within eight weeks of daily BGG administration of all the cynomolgus developed IC-mediated GN, irrespective of the initial E-CR level of the animals. However, the high E-CR cynomolgus tended to receive the higher BGG doses because of higher initial antibody levels to BGG. When the total number of glomerular deposits (determined by morphometric studies) per total BGG dose for each animal was plotted against the initial CR/E of that animal, there was a tendency for the animals with higher CR/E levels to have a lower number of glomerular deposits/BGG dose. Also, the total number of glomerular deposits correlated with the severity of the GN. During the early weeks of the GN induction protocol, the IC that formed in vivo (assessed by infusion of 125I-BGG) bound in large amounts to the circulating erythrocytes of the cynomolgus with medium or high E-CR levels. However, when tested after the onset of heavy proteinuria, which occurred between weeks 5 and 8 of daily BGG administration, the IC that formed in the circulation bound only poorly to circulating erythrocytes.

  10. ANCA-Associated Glomerulonephritis: Risk Factors for Renal Relapse

    PubMed Central

    Göçeroğlu, Arda; Berden, Annelies E.; Fiocco, Marta; Floßmann, Oliver; Westman, Kerstin W.; Ferrario, Franco; Gaskin, Gill; Pusey, Charles D.; Hagen, E. Christiaan; Noël, Laure-Hélène; Rasmussen, Niels; Waldherr, Rüdiger; Walsh, Michael; Bruijn, Jan A.; Jayne, David R. W.; Bajema, Ingeborg M.

    2016-01-01

    Relapse in ANCA-associated vasculitis (AAV) has been studied previously, but there are few studies on renal relapse in particular. Identifying patients at high risk of renal relapse may aid in optimizing clinical management. We investigated which clinical and histological parameters are risk factors for renal relapse in ANCA-associated glomerulonephritis (AAGN). Patients (n = 174) were newly diagnosed and had mild–moderate or severe renal involvement. Data were derived from two trials of the European Vasculitis Society: MEPEX and CYCAZAREM. The Cox regression model was used to identify parameters increasing the instantaneous risk (= rate) of renal relapse (useful for instant clinical decisions). For identifying predictors of renal relapse during follow-up, we used Fine & Gray’s regression model. Competing events were end-stage renal failure and death. The cumulative incidence of renal relapse at 5 years was 9.5% (95% CI: 4.8–14.3%). In the Cox model, sclerotic class AAGN increased the instantaneous risk of renal relapse. In Fine & Gray’s model, the absence of interstitial infiltrates at diagnosis was predictive for renal relapse. In this study we used two different models to identify possible relationships between clinical and histopathological parameters at time of diagnosis of AAV with the risk of experiencing renal relapse. Sclerotic class AAGN increased the instantaneous risk of renal relapse. This association is most likely due to the high proportion of sclerosed glomeruli reducing the compensatory capacity. The absence of interstitial infiltrates increased the risk of renal relapse which is a warning sign that patients with a relatively benign onset of disease may also be prone to renal relapse. Renal relapses occurring in patients with sclerotic class AAGN and renal relapses occurring in patients without interstitial infiltrates were mutually exclusive, which may indicate that they are essentially different. PMID:27973575

  11. CD11b is protective in complement-mediated immune complex glomerulonephritis

    PubMed Central

    Alexander, Jessy J; Chaves, Lee D; Chang, Anthony; Jacob, Alexander; Ritchie, Maria; Quigg, Richard J

    2015-01-01

    In chronic serum sickness, glomerular immune complexes form, yet C57BL/6 mice do not develop glomerulonephritis unless complement factor H (CfH) is absent, indicating the relevance of complement regulation. Complement receptor 3 (CD11b) and Fcγ receptors on leukocytes, and CfH on platelets, can bind immune complexes. Here we induced immune complex–mediated glomerulonephritis in CfH−/− mice chimeric for wild-type, CfH−/−, CD11b−/−, or FcRγ−/− bone marrow stem cells. Glomerulonephritis was worse in CD11b−/− chimeras compared with all others, whereas disease in FcRγ−/− and wild-type chimeras was comparable. Disease tracked strongly with humoral immune responses, but not glomerular immune complex deposits. Interstitial inflammation with M1 macrophages strongly correlated with glomerulonephritis scores. CD11b−/− chimeras had significantly more M1 macrophages and CD4+ T cells. The renal dendritic cell populations originating from bone marrow–derived CD11c+ cells were similar in all experimental groups. CD11b+ cells bearing colony-stimulating factor 1 receptor were present in kidneys, including CD11b−/− chimeras; these cells correlated negatively with glomerulonephritis scores. Thus, experimental immune complex–mediated glomerulonephritis is associated with accumulation of M1 macrophages and CD4+ T cells in kidneys and functional renal insufficiency. Hence, CD11b on mononuclear cells is instrumental in generating an anti-inflammatory response in the inflamed kidney. PMID:25565310

  12. A case of a 6-year-old girl with anti-neutrophil cytoplasmic autoantibody-negative pauci-immune crescentic glomerulonephritis.

    PubMed

    Shimizu, Maki; Sekiguchi, Takanori; Kishi, Natsuko; Goji, Aya; Takahashi, Tomoko; Kozan, Hiroko; Sakaguchi, Zenichi; Kinoshita, Yukiko; Matsuura, Sato; Suga, Kenichi; Urushihara, Maki; Kondo, Shuji; Kagami, Shoji; Ohara, Katsuaki

    2011-08-01

    A 6-year-old girl was admitted to our hospital with proteinuria, hematuria, skin rash and joint pain of the lower limbs. Due to rapid progression of renal insufficiency, hemodialysis and peritoneal dialysis were performed. She was diagnosed with rapidly progressive glomerulonephritis. Kidney biopsy showed severe crescent formation (50% of glomeruli) and no deposition of any immunoglobulins or complements. Serologically, anti-neutrophil cytoplasmic autoantibody (ANCA) was negative not only by ELISA against proteinase-3 and myeloperoxidase-ANCA but also by indirect immunofluorescent assay against cytoplasmic and perinuclear ANCA. Anti-glomerular basement membrane antibody was also negative. In the acute phase, proinflammatory cytokines such as soluble tumor necrosis factor receptor 1 (sTNFR1), soluble interleukin (IL)-2 receptor (sIL2R), IL-6 and chemokine IL-8 were elevated. The patient was diagnosed with ANCA-negative pauci-immune crescentic glomerulonephritis (CrGN). Intensive treatment with methylprednisolone pulse therapy, plasma exchange, and multiple drug therapy including prednisolone and cyclophosphamide resulted in histopathological improvement and complete remission of proteinuria. There was a possibility that sTNFR1, sIL2R, IL-6 and IL-8 might be involved in the initiation and progression of ANCA-negative pauci-immune CrGN, and to remove and suppress these cytokines might be an effective way to treat ANCA-negative pauci-immune CrGN.

  13. Structural characterization of the mesangial cell type IV collagenase and enhanced expression in a model of immune complex-mediated glomerulonephritis.

    PubMed Central

    Lovett, D. H.; Johnson, R. J.; Marti, H. P.; Martin, J.; Davies, M.; Couser, W. G.

    1992-01-01

    Secretion of glomerular cell-derived matrix metalloproteinases (MMPs) and their specific inhibitors, TIMP-1,2, may play an important role in the turnover of the glomerular extracellular matrix under basal and pathologic conditions. A 66-68 kd MMP secreted by cultured mesangial cells (MC) with activity against Type IV collagen and gelatin was purified and shown by amino-acid sequence analysis to be identical with a Type IV collagenase/gelatinase secreted by certain transformed tumor cell lines. The expression of the mesangial MMP in vivo was limited within the kidney to a small subset of the intrinsic glomerular mesangial cell population. After induction of acute anti-Thy 1.1 glomerulonephritis, there was a large increment in the number of Type IV collagenase-secreting MC, temporally coincident with the development of mesangial hypercellularity. The expression of the MMP inhibitor protein, TIMP-1, was not changed over this period. Ultrastructural studies localized the mesangial MMP to areas of evolving mesangiolysis and at sites of glomerular basement membrane disruption. Enhanced expression of the mesangial cell-derived Type IV collagenase may contribute to the evolution of glomerular injury in this model of immune complex-mediated glomerulonephritis or may be involved in the extensive matrix remodeling process that accompanies this form of glomerular injury. Images Figure 2 Figure 3 Figure 5 Figure 4 Figure 6 Figure 7 Figure 8 and Figure 9 Figure 10 Figure 11 Figure 12 PMID:1321565

  14. Immune complex erythrocyte complement receptor interactions in vivo during induction of glomerulonephritis in nonhuman primates

    SciTech Connect

    Birmingham, D.J.; Hebert, L.A.; Cosio, F.G.; VanAman, M.E. )

    1990-08-01

    Multiple lines of evidence indicate that the erythrocyte complement receptor (E-CR) system, which is unique to the primate, may play an important role in the clearing of immune complexes (ICs) from the circulation. However, all previous investigations of IC/E-CR interactions in vivo have involved the study of small amounts of preformed or passively formed ICs interacting with E-CR that were numerically in vast excess. The present study was undertaken to assess IC/E-CR interactions under conditions in which large amounts of ICs were formed in the circulation, amounts that when sustained for several weeks by daily intravenous administration of antigen resulted in the development of active glomerulonephritis. Twelve cynomolgus monkeys with E-CR levels ranging from 25 to 5000 mean CRs per erythrocyte (CR/E) were actively immunized to BGG, and 6 to 12 weeks later they were studied first at low levels of IC formation in vivo and then at high levels of IC formation in vivo (H-Protocol experiments, mean 125I-labeled BGG dose 4.9 mg/kg given over 10 minutes, a state approximating antigen-antibody equivalence). Cynomolgus monkeys with fewer than 100 CR/E showed no evidence of binding of ICs to erythrocytes with either low-dose or high-dose 125I-labeled BGG. However, cynomolgus monkeys with greater than 450 CR/E showed significant binding of ICs to erythrocytes: mean peak binding of 125I-labeled BGG to erythrocytes was 22.1% +/- 1.1% in the L-Protocol experiments and 33.4% +/- 8.0% in the H-Protocol experiments. During H-Protocol experiments, mean CR/E, measured by using a monoclonal anti-human CR1 antibody, decreased acutely, with recovery of E-CR levels within the next 24 to 72 hours. The acute decrease in E-CR levels could not be accounted for by occupancy of E-CR by ICs or by change in hematocrit.

  15. Incidental healed postinfectious glomerulonephritis: a study of 1012 renal biopsy specimens examined by electron microscopy.

    PubMed

    Haas, Mark

    2003-01-01

    Glomerulonephritis (GN) characterized by immune complex deposits typical of postinfectious GN but with a paucity or absence of overt clinical symptoms and/or urinary abnormalities may occur after a group A streptococcus infection. The overall incidence of this type of subclinical GN is not known. To address this question, electron microscopy findings in 1012 consecutive renal biopsy specimens (952 native kidney, 60 transplant) examined by a single renal pathologist from August 1999 to April 2002 were retrospectively reviewed for the presence of distinct subepithelial and intramembranous deposits indicative of postinfectious GN. Such deposits were noted in 83 biopsy specimens, including 26 with a primary diagnosis of postinfectious GN (acute, persistent, or latent) and 57 in which these deposits were an incidental finding. In each of the latter 57 cases, some or all of the deposits showed partial or extensive loss of electron density typical of partially or largely resorbed deposits. A diagnosis of incidental postinfectious GN was not made in any biopsy specimen exhibiting another immune complex-related glomerular disease that could possibly account for the deposits, composing 443 of the 1012 biopsy specimens examined. Thirty of the 57 biopsy specimens with incidental postinfectious GN showed mesangial hypercellularity, although this was focal and segmental in all but 3 cases and was not accompanied by the endocapillary hypercellularity typical of acute postinfectious lesions. Immunofluorescence microscopy revealed glomerular deposits of C3 in >90% of these biopsy specimens and IgM deposits in 66%, but only rare IgG, IgA, and Cq deposits. Twenty-three (40%) of these 57 biopsy specimens exhibited diabetic nephropathy, either alone or in combination with another lesion; for perspective, only 128 (13%) of the 1012 biopsy specimens examined showed evidence of diabetic nephropathy. In summary, incidental evidence of resolving or largely healed postinfectious GN was noted

  16. Steps Toward Unveiling the True Population of AGN: Photometric Selection of Broad-Line AGN

    NASA Astrophysics Data System (ADS)

    Schneider, Evan; Impey, C.

    2012-01-01

    We present an AGN selection technique that enables identification of broad-line AGN using only photometric data. An extension of infrared selection techniques, our method involves fitting a given spectral energy distribution with a model consisting of three physically motivated components: infrared power law emission, optical accretion disk emission, and host galaxy emission. Each component can be varied in intensity, and a reduced chi-square minimization routine is used to determine the optimum parameters for each object. Using this model, both broad- and narrow-line AGN are seen to fall within discrete ranges of parameter space that have plausible bounds, allowing physical trends with luminosity and redshift to be determined. Based on a fiducial sample of AGN from the catalog of Trump et al. (2009), we find the region occupied by broad-line AGN to be distinct from that of quiescent or star-bursting galaxies. Because this technique relies only on photometry, it will allow us to find AGN at fainter magnitudes than are accessible in spectroscopic surveys, and thus probe a population of less luminous and/or higher redshift objects. With the vast availability of photometric data in large surveys, this technique should have broad applicability and result in large samples that will complement X-ray AGN catalogs.

  17. Satellites of radio AGN in SDSS: Insights into agn triggering and feedback

    SciTech Connect

    Pace, Cameron; Salim, Samir E-mail: salims@indiana.edu

    2014-04-10

    We study the effects of radio jets on galaxies in their vicinity (satellites) and the role of satellites in triggering radio-loud active galactic nuclei (AGNs). The study compares the aggregate properties of satellites of a sample of 7220 radio AGNs at z < 0.3 (identified by Best and Heckman from the SDSS and NVSS+FIRST surveys) to the satellites of a control sample of radio-quiet galaxies, which are matched in redshift, color, luminosity, and axis ratio, as well as by environment type: field galaxies, cluster members, and brightest cluster galaxies (BCGs). Remarkably, we find that radio AGNs exhibit on average a 50% excess (17σ significance) in the number of satellites within 100 kpc even though the cluster membership was controlled (e.g., radio BCGs have more satellites than radio-quiet BCGs, etc.). Satellite excess is not confirmed for high-excitation sources, which are only 2% of radio AGN. Extra satellites may be responsible for raising the probability for hot gas AGN accretion via tidal effects or may otherwise enhance the intensity or duration of the radio-emitting phase. Furthermore, we find that the incidence of radio AGNs among potential hosts (massive ellipticals) is similar for field galaxies and for non-BCG cluster members, suggesting that AGN fueling depends primarily on conditions in the host halo rather than the parent, cluster halo. Regarding feedback, we find that radio AGNs, either high or low excitation, have no detectable effect on star formation in their satellites, as neither induced star formation nor star formation quenching is present in more than ∼1% of radio AGN.

  18. Satellites of Radio AGN in SDSS: Insights into AGN Triggering and Feedback

    NASA Astrophysics Data System (ADS)

    Pace, Cameron; Salim, Samir

    2014-04-01

    We study the effects of radio jets on galaxies in their vicinity (satellites) and the role of satellites in triggering radio-loud active galactic nuclei (AGNs). The study compares the aggregate properties of satellites of a sample of 7220 radio AGNs at z < 0.3 (identified by Best & Heckman from the SDSS and NVSS+FIRST surveys) to the satellites of a control sample of radio-quiet galaxies, which are matched in redshift, color, luminosity, and axis ratio, as well as by environment type: field galaxies, cluster members, and brightest cluster galaxies (BCGs). Remarkably, we find that radio AGNs exhibit on average a 50% excess (17σ significance) in the number of satellites within 100 kpc even though the cluster membership was controlled (e.g., radio BCGs have more satellites than radio-quiet BCGs, etc.). Satellite excess is not confirmed for high-excitation sources, which are only 2% of radio AGN. Extra satellites may be responsible for raising the probability for hot gas AGN accretion via tidal effects or may otherwise enhance the intensity or duration of the radio-emitting phase. Furthermore, we find that the incidence of radio AGNs among potential hosts (massive ellipticals) is similar for field galaxies and for non-BCG cluster members, suggesting that AGN fueling depends primarily on conditions in the host halo rather than the parent, cluster halo. Regarding feedback, we find that radio AGNs, either high or low excitation, have no detectable effect on star formation in their satellites, as neither induced star formation nor star formation quenching is present in more than ~1% of radio AGN.

  19. Reverberation Mapping of AGN Accretion Disks

    NASA Astrophysics Data System (ADS)

    Fausnaugh, Michael; AGN STORM Collaboration

    2017-01-01

    I will discuss new reverberation mapping results that allow us to investigate the temperature structure of AGN accretion disks. By measuring time-delays between broad-band continuum light curves, we can determine the size of the disk as a function of wavelength. I will discuss the detection of continuum lags in NGC 5548 reported by the AGN STORM project and implications for the accretion disk. I will also present evidence for continuum lags in two other AGN for which we recently measured black hole masses from continuum-Hbeta reverberations. The mass measurements allow us to compare the continuum lags to predictions from standard thin disk theory, and our results indicate that the accretion disks are larger than the simplest expectations.

  20. Observational evidence for thin AGN disks

    NASA Technical Reports Server (NTRS)

    Netzer, Hagai

    1992-01-01

    AGN spectrum and spectral features, polarization, inclination, and X-ray line and continuum reflection features are discussed in a critical way in order to determine the ones that are the least model-dependent. The sign and strength of absorption and emission edges are found to be model-dependent, and relativistic broadening and shifting makes them hard to detect. The presence or absence of the predicted Lyman edge polarization feature may be used as a decisive test for thin, bare AGN disks. Other good model-independent tests are several inclination-related line and continuum correlations in big AGN samples. It is shown that electron temperature near the surface of the disk can greatly exceed the disk equilibrium temperature, which causes deviations from LTE. This effect must be incorporated into realistic disk models.

  1. Probing AGN Accretion History Through X-Ray Variability

    NASA Astrophysics Data System (ADS)

    Paolillo, Maurizio; Papadakis, I.; Brandt, W. N.; Xue, Y. Q.; Luo, B.; Tozzi, P.; Shemmer, O.; Allevato, V.; Bauer, F.; Koekemoer, A.; Vignali, C.; Vito, F.; Yang, G.; Wang, J. X.; Zheng, X.

    2016-10-01

    I will present recent results on AGN variability in the CDFS survey. Using over 10 years of X-ray monitoring and comparison with local AGNs we are able to constrain the variability dependence on BH mass and accreton rate, and use it to trace the accretion hisory of the AGN population up to z=3.

  2. AGN Host Galaxy Properties And Mass Function

    NASA Astrophysics Data System (ADS)

    Bongiorno, Angela

    2016-10-01

    Supermassive black hole growth, nuclear activity, and galaxy evolution have been found to be closely related. In the context of AGN-galaxy coevolution, I will discuss about the relation found between the host galaxy properties and the central BH and I will present the latest determination of the host galaxy stellar mass function (HGMF), and the specific accretion rate distribution function (SARDF), derived from the XMM-COSMOS sample up to z˜2.5, with particular focus on AGN feedback as possible responsible mechanism for galaxy quenching.

  3. PS1-1000305 an AGN outburst?

    NASA Astrophysics Data System (ADS)

    Drake, A. J.; Mahabal, A. A.; Djorgovski, S. G.; Graham, M. J.; Williams, R.; Prieto, J.; Catelan, M.; Christensen, E.; Beshore, E. C.; Larson, S. M.

    2010-07-01

    Kankare et al. (2010, ATel#2716) recently reported the discovery of an AGN outburst (PS1-1000305) detected in PS1 taken data on May 19.3 UT. The redshift of the AGN is given by Kankare et al. as z=0.77 with the host galaxy SDSS J152844.16+425722.5. We have extracted the five year archival CSS/CRTS lightcurve at the location of PS1-1000305.

  4. Multi-Frequency View Of Jetted AGN

    NASA Astrophysics Data System (ADS)

    Giroletti, Marcello; Orienti, M.; D'Ammando, F.; Lico, R.; Giovannini, G.:

    2016-10-01

    I will present a review on the context and the most recent results about radio loud AGNs as seen in different parts of the electromagnetic spectrum, with an eye also to multi-messenger astrophysics and neutrinos in particular. I will focus on various topics of interest about RL AGNs, such as: the study of the physics of relativistic jets and particle acceleration, in particular through VLBI and gamma ray observations; the feedback to the host galaxy and on galaxy cluster scales; the possibility to probe distant and obscured environments.

  5. Star Formation and AGN activity of X-ray selected AGN host galaxies in the Chandra-COSMOS Legacy Survey

    NASA Astrophysics Data System (ADS)

    Suh, Hyewon

    2017-01-01

    One of the ongoing issues for understanding the galaxy formation and evolution is how active galactic nuclei (AGNs) affect the growth of their host galaxies. We investigate the correlations between AGN activity and star formation properties of a large sample of ~3700 X-ray selected AGNs over a wide range of luminosities (42 < log Lx < 45) up to z~5 in the Chandra-COSMOS Legacy Survey. We perform a multi-component modeling from the far-infrared, when available, to the near-UV using AGN emission from the big-blue-bump (for Type 1 AGNs), a nuclear dust torus model, a galaxy model and a starburst component for the spectral energy distributions (SEDs). Through detailed analysis of SEDs, we derive AGN host galaxy properties, such as stellar masses, star formation rates (SFRs), and AGN luminosities. We find that AGN host galaxies have, on average, similar SFRs compared to the normal star-forming main sequence galaxies, suggesting no significant enhancement or quenching of star formation. The average SFR of AGN host galaxies shows a flat distribution in bins of AGN luminosity, consistent with recent ideas that the shorter variability timescale of AGN compared to star formation can lead to a flat relationship between the SFR and black hole accretion rates. Our results suggest that both star formation and nuclear activity in the majority of AGN host galaxies might be driven more by internal secular processes at z<3, implying that they have substantially grown at much earlier epoch.

  6. Glomerular nitrite synthesis in in situ immune complex glomerulonephritis in the rat.

    PubMed Central

    Cook, H. T.; Sullivan, R.

    1991-01-01

    Nitrite (NO2-) is the major end product of nitric oxide (NO) production in cell culture. The authors have examined nitrite production by glomeruli in in situ immune complex glomerulonephritis in the rat. Glomerulonephritis was induced by unilateral renal perfusion of cationized human gamma G immunoglobulin (IgG) in preimmunized rats. NO2- was measured in culture supernatants of isolated glomeruli after 48 hours. NO2- was produced by nephritic glomeruli with a maximum 4 days after induction of glomerulonephritis (24.4 +/- 11.4 pmol/glomerulus/48 hours). Production was increased by lipopolysaccharide (LPS; 1 micrograms/ml) (54 +/- 4.9 pmol/glomerulus; P less than 0.001). NO2- production was inhibited by the nitric oxide synthase inhibitor NG-monomethyl-L-arginine demonstrating synthesis through NO. Dexamethasone (10(-7) mol/l [molar]) reduced LPS-stimulated production by peritoneal macrophages and nephritic glomeruli (P less than 0.01). Macrophages isolated from nephritic glomeruli produced NO2- (4.9 +/- 0.6 nmols/10(5) cells). The production of NO by nephritic glomeruli has implications for mechanisms of glomerular injury and glomerular hemodynamics. The effect of dexamethasone may explain in part the ameliorative effect of steroids in glomerulonephritis. Images Figure 4 PMID:1951626

  7. Bartonella Endocarditis and Pauci-Immune Glomerulonephritis: A Case Report and Review of the Literature.

    PubMed

    Raybould, Jillian E; Raybould, Alison L; Morales, Megan K; Zaheer, Misbah; Lipkowitz, Michael S; Timpone, Joseph G; Kumar, Princy N

    2016-09-01

    Among culture-negative endocarditis in the United States, Bartonella species are the most common cause, with Bartonella henselae and Bartonella quintana comprising the majority of cases. Kidney manifestations, particularly glomerulonephritis, are common sequelae of infectious endocarditis, with nearly half of all Bartonella patients demonstrating renal involvement. Although a pauci-immune pattern is a frequent finding in infectious endocarditis-associated glomerulonephritis, it is rarely reported in Bartonella endocarditis. Anti-neutrophil cytoplasmic antibody (ANCA) positivity can be seen with many pathogens causing endocarditis and has been previously reported with Bartonella species. In addition, ANCA-associated vasculitis can also present with renal and cardiac involvement, including noninfectious valvular vegetations and pauci-immune glomerulonephritis. Given the overlap in their clinical presentation, it is difficult to differentiate between Bartonella endocarditis and ANCA-associated vasculitis but imperative to do so to guide management decisions. We present a case of ANCA-positive Bartonella endocarditis with associated pauci-immune glomerulonephritis that was successfully treated with medical management alone.

  8. Glomerulonephritis mediated by antibody to glomerular basement membrane. Immunological, clinical, and histopathological characteristics.

    PubMed Central

    McPhaul, J J; Mullins, J D

    1976-01-01

    A prospective study was undertaken to establish the incidence of glomerular basement membrane (GBM) antibody-mediated glomerulonephritis and its histopathological characteristics in a clinical group of patients presenting with renal disease. Biopsies from 43 of 409 consecutive patients technically satisfactory for direct immunofluorescent (IF) examination had diffuse and generalized linear localization of host immunoglobulin (Ig); two other badly scarred kidneys tested negative to IF although GBM antibodies were eluted. Confirmatory evidence of GBM antibody-mediated disease in these patients came from whole kidney or biopsy elutions (15 patients), serologic assays for circulating GBM antibodies by indirect IF (9 of 38 patients), radioimmunoassay (26 of 34), and hemagglutination (31 of 32). Although sera were not tested from six patients, circulating antibodies were demonstrated by some test in 36 of 39 of the remainder. Histologically, half of the patients had minor and nonspecific glomerular abnormalities or mild focal proliferative glomerulonephritis. More severely involved kidneys had focal necrotizing (17%), rapidly progressive (7%), and chronic, usually sclerosing, glomerulonephritis (27%). Clinical courses of these patients comparably were quite variable, ranging from indolent microhematuria and/or gross hematuric bouts to progressive renal failure; nephrotic syndrome was observed in 11 patients. GBM antibody-mediated glomerulonephritis may be a relatively mild disease with apparently stable renal function, although 16 patients have experienced functional deterioration, and 11 have progressed to dialysis, renal transplantation, or death. Images PMID:56340

  9. NF-κB upregulates ubiquitin C-terminal hydrolase 1 in diseased podocytes in glomerulonephritis.

    PubMed

    Zhang, Hongxia; Mao, Xing; Sun, Yu; Hu, Ruimin; Luo, Weili; Zhao, Zhonghua; Chen, Qi; Zhang, Zhigang

    2015-08-01

    Podocyte injury is a pivotal factor during the progression of glomerular diseases. It has been demonstrated that the expression of ubiquitin carboxy-terminal hydrolase L1 (UCH-L1) is increased in injured podocytes in a number of types of glomerulonephritis. However, its mechanism of regulation remains to be elucidated. A previous study by our group suggested that UCH-L1 is a downstream protein of nuclear factor (NF)-κB signaling. In the present study, the involvement of NF-κB in the regulation of the expression of UCH-L1 was investigated in diseased podocytes in vivo and in vitro. Increases in the expression of phosphorylated NF-κB at p65 and UCH-L1 were detected using immunohistochemical analysis of kidney biopsy tissues from 56 cases of nephritis, including immunoglobulin A nephropathy, membranous glomerulonephritis and lupus nephritis. The two indicators were also analyzed using western blot analysis in cultured murine podocytes stimulated by inflammatory factors. The results of the present study demonstrated that in human renal biopsies of several cases of immune complex-mediated glomerulonephritis, the increases of NF-κB and UCH-L1 were positively correlated with the number of diseased podocytes. By contrast, in non-immune complex-mediated glomerulonephritis, no clear activation of NF-κB and increase of UCH-L1 expression was observed. In vitro, immune stimulation also led to the upregulation of UCH-L1 through the NF-κB signaling pathway in mouse podocytes. In conclusion, the results of the present study suggested that the activation of NF-κB and upregulation of UCH-L1 in podocytes may be vital in podocyte injury associated with immune complex-mediated glomerulonephritis.

  10. The effects of soluble recombinant complement receptor 1 on complement-mediated experimental glomerulonephritis.

    PubMed

    Couser, W G; Johnson, R J; Young, B A; Yeh, C G; Toth, C A; Rudolph, A R

    1995-05-01

    Complement is a major mediator of tissue injury in several types of glomerulonephritis. However, no therapeutic agents that inhibit complement activation are available for human use. sCR1 (TP10, BRL 55736) is a recombinant, soluble human complement receptor 1 (CR1) molecule lacking transmembrane and cytoplasmic domains that inhibits C3 and C5 convertase activity by preferentially binding C4b and C3b. To test the efficacy of sCR1 on complement-mediated glomerulonephritis, rats were pretreated with sCR1 (60 mg/kg per day) before and during the induction of three models of complement-dependent glomerulonephritis (concanavalin A and antithymocyte serum models of proliferative glomerulonephritis, passive Heyman nephritis). Daily sCR1 and complement hemolytic activity levels were measured, and renal histology and urine protein excretion were examined. Mean serum sCR1 levels of 100 to 200 micrograms/mL were maintained with a reduction in complement hemolytic activity to less than 15% in most animals. In the antithymocyte serum model, sCR1-treated animals had significant reductions in mesangiolysis, glomerular platelet and macrophage infiltrates, and proteinuria at 48 h. In the concanavalin A model, sCR1 significantly reduced glomerular C3 and fibrin deposits, platelet infiltrates, and proteinuria at 48 h. In passive Heymann nephritis, proteinuria was also significantly reduced (199 +/- 8.5 versus 125 +/- 16 mg/day, P < 0.002) at 5 days. It was concluded that sCR1 significantly reduces both morphologic and functional consequences of several different types of complement-mediated glomerulonephritis and deserves evaluation as a potential therapeutic agent in complement-mediated immune glomerular disease in humans.

  11. The HORIZON-AGN simulation: morphological diversity of galaxies promoted by AGN feedback

    NASA Astrophysics Data System (ADS)

    Dubois, Yohan; Peirani, Sébastien; Pichon, Christophe; Devriendt, Julien; Gavazzi, Raphaël; Welker, Charlotte; Volonteri, Marta

    2016-12-01

    The interplay between cosmic gas accretion on to galaxies and galaxy mergers drives the observed morphological diversity of galaxies. By comparing the state-of-the-art hydrodynamical cosmological simulations HORIZON-AGN and HORIZON-NOAGN, we unambiguously identify the critical role of active galactic nuclei (AGN) in setting up the correct galaxy morphology for the massive end of the population. With AGN feedback, typical kinematic and morpho-metric properties of galaxy populations as well as the galaxy-halo mass relation are in much better agreement with observations. Only AGN feedback allows massive galaxies at the centre of groups and clusters to become ellipticals, while without AGN feedback those galaxies reform discs. It is the merger-enhanced AGN activity that is able to freeze the morphological type of the post-merger remnant by durably quenching its quiescent star formation. Hence morphology is shown to be driven not only by mass but also by the nature of cosmic accretion: at constant galaxy mass, ellipticals are galaxies that are mainly assembled through mergers, while discs are preferentially built from the in situ star formation fed by smooth cosmic gas infall.

  12. A Global Picture of AGN Winds

    NASA Technical Reports Server (NTRS)

    Kazanas, D.; Fukumura, K.

    2011-01-01

    We present a unified structure for accretion powered sources across their entire luminosity range from accreting galactic black holes to the most luminous quasars, with emphasis on AGN and their phenomenology. Central to this end is the notion of MHD winds launched from the accretion disks that power these objects. This work similar in spirit to that of Elvis of more that a decade ago, provides, on one hand, only the broadest characteristics of these objects, but on the other, also scaling laws that allow one to make contact with objects of different luminosity. The conclusion of this work is that AGN phenomenology can be accounted for in terms of dot(m), the wind mass flux in units of the Eddington value, the observer's inclination angle theta and alpha_OX the logarithmic slope between UV and X-ray flares. However given the well known correlation between alpha(sub ox) and UV Luminosity, we conclude that the AGN structure depends on only two parameters. The small number of model parameters hence suggests that an understanding of the global AGN properties maybe within reach.

  13. The AGN Luminosity Fraction in Galaxy Mergers

    NASA Astrophysics Data System (ADS)

    Dietrich, Jeremy; Weiner, Aaron; Ashby, Matthew; Martinez-Galarza, Juan Rafael; Smith, Howard Alan

    2017-01-01

    Galaxy mergers are key events in galaxy evolution, generally triggering massive starbursts and AGNs. However, in these chaotic systems, it is not yet known what fraction each of these two mechanisms contributes to the total luminosity. Here we measure and model spectral energy distributions (SEDs) using the Code for Investigating Galaxy Emission (CIGALE) in up to 33 broad bands from the UV to the far-IR for 23 IR-luminous galaxies to estimate the fraction of the bolometric IR luminosity that can be attributed to the AGN. The galaxies are split nearly evenly into two subsamples: late-stage mergers, found in the IRAS Revised Bright Galaxy Sample or Faint Source Catalog, and early-stage mergers found in the Spitzer Interacting Galaxy Sample. We find that the AGN contribution to the total IR luminosity varies greatly from system to system, from 0% up to ~90%, but is substantially greater in the later-stage and brighter mergers. This is consistent with what is known about galaxy evolution and the triggering of AGNs.The SAO REU program is funded in part by the National Science Foundation REU and Department of Defense ASSURE programs under NSF Grant no. 1262851, and by the Smithsonian Institution.

  14. NuSTAR Observations of Bright AGNs

    NASA Astrophysics Data System (ADS)

    Elvis, Martin; Ballantyne, D. R.; Blandford, R. D.; Boggs, S.; Boydstun, K.; Brenneman, L.; Cappi, M.; Christensen, F.; Craig, W.; Fabian, A.; Fuerst, F.; Guainazzi, M.; Hailey, C. J.; Harrison, F.; Madejski, G. M.; Marinucci, A.; Matt, G.; Nandra, K.; Reynolds, C. S.; Stern, D.; Walton, D.; Zhang, W.; NuSTAR Team

    2013-01-01

    The dramatically improved signal-to-noise provided by NuSTAR up to ~80 keV allows a qualitative change in our understanding of the X-ray emission of Active Galactic Nuclei (AGNs). Despite intensive investigation for over 30 years, during which the 0.1-10 keV spectra and variability of AGNs have been mapped out in detail, we do not know the origin of the X-ray source in AGNs. The "standard model" of supermassive black hole, accretion disk and relativistic jet does not predict an X-ray source in a straightforward way. It is usually assumed that the X-rays were UV photons from the accretion disk that have been Compton up-scattered in a "hot corona", but the temperature, optical depth and geometry of this corona are unknown - if it exists. NuSTAR enables the measurement of the high energy cut-off of the X-ray spectrum, and so the corona temperature, to be measured precisely for the first time, and tests the relativistic Fe-K line and Compton reflection models. If this model is correct then, with Suzaku and XMM-Newton, NuSTAR can measure black hole spins to high accuracy. We outline the NuSTAR GTO program on bright, unobscured, AGNs including simultaneous observations with Suzaku and XMM-Newton, and show early data.

  15. Mabel Agnes Elliott, We Hardly Knew You

    ERIC Educational Resources Information Center

    McGonigal, Kathryn; Galliher, John F.

    2008-01-01

    Sociologist Mabel Agnes Elliott was elected the fourth president of the Society for the Study of Social Problems in 1956-1957 and was the first woman to hold this position. She was an anti-war activist, a feminist and a creative and diligent writer. Yet she experienced many challenges. The Federal Bureau of Investigation kept an active file on…

  16. What are the galaxies that host MIR-selected AGN?

    NASA Astrophysics Data System (ADS)

    Rosario, David

    2016-08-01

    Infra-red selection techniques, sensitive to dust strongly heated by an AGN, offer a way to identify some of the most obscured accretion events in the Universe. I will describe the results of a comprehensive multi-wavelength study of AGN to z>2 selected using Spitzer/IRAC based methods in the COSMOS field. Armed with AGN-optimised redshifts and stellar masses, we explore the dust emission from the active nucleus and the host galaxy. We demonstrate that IR-selected AGN tend to be found in low mass host galaxies, when compared to other AGN identification methods. The star-formation rates of obscured and unobscured IR-selected AGN are very similar, implying that large-scale obscuration with co-eval star-bursts are not found in a major proportion of heavily obscured AGN.

  17. ANCA-associated crescentic glomerulonephritis with mesangial IgA deposits.

    PubMed

    Haas, M; Jafri, J; Bartosh, S M; Karp, S L; Adler, S G; Meehan, S M

    2000-10-01

    Antineutrophil cytoplasmic autoantibodies (ANCA) are commonly associated with a necrotizing and crescentic glomerulonephritis (GN) that is pauci-immune, with few or no glomerular immune complex deposits detectable by immunofluorescence (IF) or electron microscopy (EM). Immunoglobulin A (IgA) nephropathy may also be manifest as a crescentic GN, but it is characterized by mesangial immune complex deposits containing IgA and is rarely associated with myeloperoxidase (MPO)- or proteinase 3 (PR3)-specific ANCA when an enzyme immunoassay is used to detect these antibodies. This report describes six patients with severe crescentic GN with mesangial IgA deposits by IF and mesangial electron-dense deposits by EM in patients with positive ANCA serological test results (four patients, anti-PR3; one patient, anti-MPO; one patient, anti-PR3 and anti-MPO). Patients presented with acute or progressive renal insufficiency, hematuria, proteinuria (nephrotic range in two patients), and hypertension. Three patients had evidence of systemic vasculitis: two patients at initial presentation and one patient later in the clinical course. Renal biopsy specimens showed crescents in greater than 50% of glomeruli in all cases, but only mild, focal and segmental mesangial and endocapillary hypercellularity, more typical of ANCA-associated crescentic GN than of crescentic IgA nephropathy without associated ANCA. Semiquantitative analysis of mesangial and endocapillary cellularity performed on renal biopsy slides from these six patients and from eight ANCA-negative patients with IgA nephropathy and crescents in greater than 50% of glomeruli showed significantly greater hypercellularity in the ANCA-negative cases. Three of five ANCA-positive patients for whom follow-up clinical data were available showed improved renal function after treatment with cyclophosphamide and corticosteroids and have not developed end-stage renal disease 17, 20, and 25 months postbiopsy. The remaining two patients were

  18. AGN-host galaxy connection: multiwavelength study

    NASA Astrophysics Data System (ADS)

    Pović, M.; Sánchez-Portal, M.; García, A. M. Pérez; Bongiovanni, A.; Cepa, J.; Cepa

    2013-02-01

    The connection between active galactic nuclei (AGN) and their hosts showed to be important for understanding the formation and evolution of active galaxies. Using X-ray and deep optical data, we study how morphology and colours are related to X-ray properties at redshifts z<=2.0 for a sample of > 300 X-ray detected AGN in the Subaru/XMM-Newton Deep Survey (SXDS; Furusawa et al. 2008) and Groth-Westphal Strip (GWS; Pović et al. 2009) fields. We performed our morphological classification using the galSVM code (Huertas-Company et al. 2008), which is a new method that is particularly suited when dealing with high-redshift sources. To separate objects between X-ray unobscured and obscured, we used X-ray hardness ratio HR(0.5-2 keV/2-4.5 keV). Colour-magnitude diagrams were studied in relationship to redshift, morphology, X-ray obscuration, and X-ray-to-optical flux ratio. Around 50% of X-ray detected AGN at z<=2.0 analysed in this work reside in spheroidal and bulge-dominated galaxies, while at least 18% have disk-dominated hosts. This suggests that different mechanisms may be responsible for triggering the nuclear activity. When analysing populations of X-ray detected AGN in both colour-magnitude (CMD) and colour-stellar mass diagrams (Figure 1), the highest number of sources is found to reside in the green valley at redshifts ~ 0.5-1.5. For the first time we studied CMD of these AGN in relation to morphology and X-ray obscuration, finding that they can reside in both early- and late-type hosts, where both morphological types cover similar ranges of X-ray obscuration (Figure 1). Our findings appear to confirm some previous suggestions that X-ray selected AGN residing in the green valley represent a transitional population (e.g. Nandra et al. 2007, Silverman et al. 2008, Treister et al. 2009), quenching star formation by means of different AGN feedback mechanisms and evolving to red-sequence galaxies. More details on analysis and results presented here can be found in

  19. A POWERFUL AGN OUTBURST IN RBS 797

    SciTech Connect

    Cavagnolo, K. W.; McNamara, B. R.; Wise, M. W.; Nulsen, P. E. J.; Gitti, M.; Brueggen, M.; Rafferty, D. A.

    2011-05-10

    Utilizing {approx}50 ks of Chandra X-Ray Observatory imaging, we present an analysis of the intracluster medium (ICM) and cavity system in the galaxy cluster RBS 797. In addition to the two previously known cavities in the cluster core, the new and deeper X-ray image has revealed additional structure associated with the active galactic nucleus (AGN). The surface brightness decrements of the two cavities are unusually large and are consistent with elongated cavities lying close to our line of sight. We estimate a total AGN outburst energy and mean jet power of {approx}(3-6) x 10{sup 60} erg and {approx}(3-6) x 10{sup 45} erg s{sup -1}, respectively, depending on the assumed geometrical configuration of the cavities. Thus, RBS 797 is apparently among the most powerful AGN outbursts known in a cluster. The average mass accretion rate needed to power the AGN by accretion alone is {approx}1 M{sub sun} yr{sup -1}. We show that accretion of cold gas onto the AGN at this level is plausible, but that Bondi accretion of the hot atmosphere is probably not. The brightest cluster galaxy (BCG) harbors an unresolved, non-thermal nuclear X-ray source with a bolometric luminosity of {approx}2 x 10{sup 44} erg s{sup -1}. The nuclear emission is probably associated with a rapidly accreting, radiatively inefficient accretion flow. We present tentative evidence that star formation in the BCG is being triggered by the radio jets and suggest that the cavities may be driving weak shocks (M {approx} 1.5) into the ICM, similar to the process in the galaxy cluster MS 0735.6+7421.

  20. AGN Variability: Probing Black Hole Accretion

    NASA Astrophysics Data System (ADS)

    Moreno, Jackeline; O'Brien, Jack; Vogeley, Michael S.; Richards, Gordon T.; Kasliwal, Vishal P.

    2017-01-01

    We combine the long temporal baseline of Sloan Digital Sky Survey (SDSS) for quasars in Stripe 82 with the high precision photometry of the Kepler/K2 Satellite to study the physics of optical variability in the accretion disk and supermassive black hole engine. We model the lightcurves directly as Continuous-time Auto Regressive Moving Average processes (C-ARMA) with the Kali analysis package (Kasliwal et al. 2016). These models are extremely robust to irregular sampling and can capture aperiodic variability structure on various timescales. We also estimate the power spectral density and structure function of both the model family and the data. A Green's function kernel may also be estimated for the resulting C-ARMA parameter fit, which may be interpreted as the response to driving impulses such as hotspots in the accretion disk. We also examine available spectra for our AGN sample to relate observed and modelled behavior to spectral properties. The objective of this work is twofold: to explore the proper physical interpretation of different families of C-ARMA models applied to AGN optical flux variability and to relate empirical characteristic timescales of our AGN sample to physical theory or to properties estimated from spectra or simulations like the disk viscosity and temperature. We find that AGN with strong variability features on timescales resolved by K2 are well modelled by a low order C-ARMA family while K2 lightcurves with weak amplitude variability are dominated by outliers and measurement errors which force higher order model fits. This work explores a novel approach to combining SDSS and K2 data sets and presents recovered characteristic timescales of AGN variability.

  1. AGN flickering on 10-100 kyr timescales

    NASA Astrophysics Data System (ADS)

    Sartori, Lia F.; Schawinski, Kevin; Kill, Bill; Maksym, Peter; Koss, Michael; Argo, Megan; Urry, Meg; Wong, Ivy; Lintott, Chris

    2016-08-01

    The study of AGN variability on timescales of 10^4-10^5 years is important in order to understand the BH - host galaxy interaction and coevolution. The discovery of "Hanny's Voorwerp" (HV), an extended emission line region associated with the nearby galaxy IC 2497, provided us with a laboratory to study AGN variability over such timescales. HV was illuminated by a strong quasar in IC 2497, but this quasar significantly shut down in the last 200 kyrs. Thanks to its recent shutdown we can now explore the host galaxy unimpeded by the presence of a quasar dominating the observations, while the Voorwerp preserves the echoes of its past activity. Recent studies on the optical properties of hard X-ray selected AGN suggest that AGN may flicker on and off hundreds or thousands times with each burst lasting ~10^5 yrs. Systems similar to IC 2497 and HV, the so-called Voorwerpjes, allow us to constrain the last stages of the AGN lifecycle. On the other hand, we recently suggested that the switch on phase may be observed in the so-called optically elusive AGN. In this talk I will review both observational evidence and results from simulation work which support this picture, and explain how optically elusive AGN and Voorwerpjes galaxies can help us to understand different phases of the AGN lifecycle. Moreover, I will discuss possible implications for AGN feedback, BH - host galaxy coevolution, and the analogy between AGN and X-ray binaries accretion physics.

  2. The Lick AGN Monitoring Project 2016: Extending Reverberation Mapping to Higher Luminosity AGNs

    NASA Astrophysics Data System (ADS)

    U, Vivian; LAMP2016 Collaboration

    2017-01-01

    The technique of reverberation mapping has been used to estimate virial black hole masses and, more fundamentally, to probe the broad line region structure in Seyfert I galaxies. Efforts from the previous Lick AGN Monitoring Project (LAMP) campaigns and other studies to date have culminated in a large sample of reverberation mapped AGNs and measurements of their black hole masses, which in turn enabled major improvement to various AGN scaling relations. However, the high-luminosity end of such relations remains poorly constrained; this is because of observational challenges presented by the weaker continuum flux variations and longer time dilation in these sources. To this end, we have initiated a new LAMP2016 campaign to target AGNs with luminosities of 10^44 erg/s, with predicted H-beta lags of ~20 - 60 days or black hole masses of 10^7 - 10^8.5 Msun. Designed to monitor ~20 AGNs biweekly from Spring 2016 through Winter 2017 with the Kast spectrograph on the 3-m Shane Telescope at Lick Observatory, we aim to probe luminosity-dependent trends in broad line region structure and dynamics, improve calibrations for single-epoch estimates of high-redshift quasar black hole masses, and test photoionization models for the radially-stratified structure of the broad line region. In this talk, I will present the overview and scope of LAMP2016 and show preliminary results from our ongoing campaign.

  3. AGN Coronae through a Jet Perspective

    NASA Astrophysics Data System (ADS)

    King, Ashley L.; Lohfink, Anne; Kara, Erin

    2017-02-01

    This paper presents an in-depth look at the jet and coronal properties of 41 active galactic nuclei (AGNs). Utilizing the highest quality NuSTAR, XMM-Newton, and NRAO VLA Sky Survey 1.4 GHz data, we find that the radio Eddington luminosity inversely scales with X-ray reflection fraction, and positively scales with the distance between the corona and the reflected regions in the disk. We next investigate a model fit to the data that predicts the corona is outflowing and propagates into the large-scale jet. We find this model describes the data well and predicts that the corona has mildly relativistic velocities, 0.04< β < 0.40. We discuss our results in the context of disk–jet connections in AGNs.

  4. AGN feedback in the Perseus cluster

    NASA Astrophysics Data System (ADS)

    Gendron-Marsolais, Marie-Lou; Hlavacek-Larrondo, Julie; Clarke, Tracy E.; Intema, Huib; Fabian, Andrew C.; Taylor, Gregory B.; Blundell, Katherine

    2016-04-01

    Deep Chandra images of the Perseus cluster of galaxies have revealed a succession of cavities created by the jets of the central supermassive black hole, pushing away the X-ray emitting gas and leaving bubbles filled with radio emission. Perseus is one of the rare examples showing buoyantly rising lobes from past radio outbursts, characterized by a steep spectral index and known as ghost cavities. All of these structures trace the complete history of mechanical AGN feedback over the past 500 Myrs. I will present results on new, ultra deep 230-470 MHz JVLA data. This low-frequency view of the Perseus cluster will probe the old radio-emitting electron population and will allow us to build the most detailed map of AGN feedback in a cluster thus far.

  5. Study of the mid-infrared properties of obscured AGN

    NASA Astrophysics Data System (ADS)

    Severgnini, P.; Caccianiga, A.; della Ceca, R.

    2008-10-01

    The comprehension of the physical properties of obscured AGNs is one of the main goals of the high energy astronomy given their key role in tracing the accretion history of the Universe. Although X-ray and infrared data of AGN with a different level of absorption could provide a direct tool to test the predictions of the AGN models, only few sparse SED of obscured AGN are available so far. We present here the results obtained from Spitzer observations of a statistically complete sample of obscured AGN drawn from the XMM-Newton Hard Bright Sample. This is the largest hard X-ray sample with a complete spectroscopic identification. The Spitzer data, combined with good X-ray and optical spectroscopic data, has allowed us to define powerful diagnostic plots to select heavily obscured AGNs and to build up their spectral energy distributions.

  6. Granulomatosis with polyangiitis: rapidly progressive necrotizing glomerulonephritis in a pediatric patient

    PubMed Central

    Luna, Mariana; Bocanegra, Victoria; Vallés, Patricia G

    2014-01-01

    Granulomatosis with polyangiitis (GPA) is associated with a broad range of clinical manifestations including renal disease. It is a systemic vasculitis that is rarely encountered in children. We present a 14-year-old girl who suffered from pharyngitis 1 week before admittance to hospital. She was admitted for macroscopic hematuria and oliguria, under the possibility of nephritic syndrome. Renal failure with rapidly progressive glomerulonephritis occurred within 24 hours. Immunologic tests showed the presence of type-C anti-neutrophil cytoplasmic antibodies (c-ANCA with antiproteinase 3 specificity) and renal biopsy revealed pauci-immune crescentic focal necrotizing glomerulonephritis. Treatment including methylprednisolone and cyclophosphamide intravenous pulses allowed renal recovery after 3 weeks. The clinical, hematological, and biochemical parameters improved substantially, achieving remission. Granulomatosis with polyangiitis, although rare in children, should be considered in the above clinical scenario. This case underlines that knowledge of renal histology diagnosis and early aggressive immunosuppressive therapy are essential for the management of these patients. PMID:24790466

  7. [First case of primary IgA glomerulonephritis (Berger's disease) in Senegal].

    PubMed

    Diouf, B; Diao, M; Niang, A; Ka, E F; Moreira Diop, T

    1999-01-01

    Berger's disease or IgA glomerulonephritis is the most common glomerular nephropathy in Europe and represent a rare event in blacks. Here, we describe the case of a 43 years old black Senegalese whose disease was discovered while investigating a persistent proteinuria with high blood pressure and chronic renal failure, but without hematuria. We point out the uncommon feature of this clinical presentation and the importance of bad prognostic factors presented by this patient. We obtained a good outcome by means of converting enzyme inhibitors and corticosteroid therapies: regression of renal failure and normalization of blood pressure. The generalization of renal biopsy practice would lead to a better knowledge of the incidence of this disease among Senegalese people. Indeed, renal biopsy is the main tool to diagnose glomerulonephritis and subsequently adapt the therapy aimed at preventing the possible evolution to end stage renal disease.

  8. AGES: THE AGN AND GALAXY EVOLUTION SURVEY

    SciTech Connect

    Kochanek, C. S.; Eisenstein, D. J.; Caldwell, N.; Jones, C.; Murray, S. S.; Forman, W. R.; Green, P.; Cool, R. J.; Assef, R. J.; Eisenhardt, P.; Stern, D.; Jannuzi, B. T.; Dey, A.; Brown, M. J. I.; Gonzalez, A. H.

    2012-05-01

    The AGN and Galaxy Evolution Survey (AGES) is a redshift survey covering, in its standard fields, 7.7 deg{sup 2} of the Booetes field of the NOAO Deep Wide-Field Survey. The final sample consists of 23,745 redshifts. There are well-defined galaxy samples in 10 bands (the B{sub W} , R, I, J, K, IRAC 3.6, 4.5, 5.8, and 8.0 {mu}m, and MIPS 24 {mu}m bands) to a limiting magnitude of I < 20 mag for spectroscopy. For these galaxies, we obtained 18,163 redshifts from a sample of 35,200 galaxies, where random sparse sampling was used to define statistically complete sub-samples in all 10 photometric bands. The median galaxy redshift is 0.31, and 90% of the redshifts are in the range 0.085 < z < 0.66. Active galactic nuclei (AGNs) were selected as radio, X-ray, IRAC mid-IR, and MIPS 24 {mu}m sources to fainter limiting magnitudes (I < 22.5 mag for point sources). Redshifts were obtained for 4764 quasars and galaxies with AGN signatures, with 2926, 1718, 605, 119, and 13 above redshifts of 0.5, 1, 2, 3, and 4, respectively. We detail all the AGES selection procedures and present the complete spectroscopic redshift catalogs and spectral energy distribution decompositions. Photometric redshift estimates are provided for all sources in the AGES samples.

  9. Intermediate inclinations of type 2 Coronal-Line Forest AGN

    NASA Astrophysics Data System (ADS)

    Rose, Marvin; Elvis, Martin; Crenshaw, Michael; Glidden, Ana

    2015-07-01

    Coronal-Line Forest Active Galactic Nuclei (CLiF AGN) are remarkable in the sense that they have a rich spectrum of dozens of coronal emission lines (e.g. [Fe VII], [Fe X] and [Ne V]) in their spectra. Rose, Elvis & Tadhunter suggest that the inner obscuring torus wall is the most likely location of the coronal line region in CLiF AGN, and the unusual strength of the forbidden high-ionization lines is due to a specific AGN-torus inclination angle. Here, we test this suggestion using mid-IR colours (4.6-22 μm) from the Wide-Field Infrared Survey Explorer for the CLiF AGN. We use the Fischer et al. result that showed that as the AGN-torus inclination becomes more face on, the Spitzer 5.5-30 μm colours become bluer. We show that the [W2-W4] colours for the CLiF AGN (<[W2-W4]> = 5.92 ± 0.12) are intermediate between Sloan Digital Sky Survey (SDSS) type 1 (<[W2-W4]> = 5.22 ± 0.01) and type 2 AGN (<[W2-W4]> = 6.35 ± 0.03). This implies that the AGN-torus inclinations for the CLiF AGN are indeed intermediate, supporting the work of Rose, Elvis & Tadhunter. The confirmed relation between CLiF AGN and their viewing angle shows that CLiF AGN may be useful for our understanding of AGN unification.

  10. Ultra-fast outflows (aka UFOs) from AGNs and QSOs

    NASA Astrophysics Data System (ADS)

    Cappi, M.; Tombesi, F.; Giustini, M.

    During the last decade, strong observational evidence has been accumulated for the existence of massive, high velocity winds/outflows (aka Ultra Fast Outflows, UFOs) in nearby AGNs and in more distant quasars. Here we briefly review some of the most recent developments in this field and discuss the relevance of UFOs for both understanding the physics of accretion disk winds in AGNs, and for quantifying the global amount of AGN feedback on the surrounding medium.

  11. Ameliorative effects of arctiin from Arctium lappa on experimental glomerulonephritis in rats.

    PubMed

    Wu, Jian-Guo; Wu, Jin-Zhong; Sun, Lian-Na; Han, Ting; Du, Jian; Ye, Qi; Zhang, Hong; Zhang, Yu-Guang

    2009-11-01

    Membranous glomerulonephritis (MGN) remains the most common cause of adult-onset nephrotic syndrome in the world and up to 40% of untreated patients will progress to end-stage renal disease. Although the treatment of MGN with immunosuppressants or steroid hormones can attenuate the deterioration of renal function, numerous treatment-related complications have also been established. In this study, the ameliorative effects of arctiin, a natural compound isolated from the fruits of Arctium lappa, on rat glomerulonephritis induced by cationic bovine serum albumin (cBSA) were determined. After oral administration of arctiin (30, 60, 120 mg/kgd) for three weeks, the levels of serum creatinine (Scr) and blood urea nitrogen (BUN) and 24-h urine protein content markedly decreased, while endogenous creatinine clearance rate (ECcr) significantly increased. The parameters of renal lesion, hypercellularity, infiltration of polymorphonuclear leukocyte (PMN), fibrinoid necrosis, focal and segmental proliferation and interstitial infiltration, were reversed. In addition, we observed that arctiin evidently reduced the levels of malondialdehyde (MDA) and pro-inflammatory cytokines including interleukin-6 (IL-6) and tumor necrosis factor (TNF-alpha), suppressed nuclear factor-kappaB p65 (NF-kappaB) DNA binding activity, and enhanced superoxide dismutase (SOD) activity. These findings suggest that the ameliorative effects of arctiin on glomerulonephritis is carried out mainly by suppression of NF-kappaB activation and nuclear translocation and the decreases in the levels of these pro-inflammatory cytokines, while SOD is involved in the inhibitory pathway of NF-kappaB activation. Arctiin has favorable potency for the development of an inhibitory agent of NF-kappaB and further application to clinical treatment of glomerulonephritis, though clinical studies are required.

  12. Renal biopsy in patients with systemic lupus erythematosus: Not just lupus glomerulonephritis!

    PubMed

    Howell, David N

    2017-01-01

    Kidney biopsy is a mainstay in the diagnosis and management of renal disease in patients with systemic lupus erythematosus. Though biopsies from patients with lupus typically show various forms of immune complex glomerulonephritis, other pathologies are occasionally encountered, including unusual lupus-related nephropathies, other forms of autoimmune disease, and occasional renal disorders without any direct connection with lupus or autoimmunity. Electron microscopy is a powerful tool for detecting and classifying these unusual conditions, which frequently have important therapeutic and prognostic implications.

  13. Suppression of Rapidly Progressive Mouse Glomerulonephritis with the Non-Steroidal Mineralocorticoid Receptor Antagonist BR-4628

    PubMed Central

    Ma, Frank Y.; Han, Yingjie; Nikolic-Paterson, David J.; Kolkhof, Peter; Tesch, Greg H.

    2015-01-01

    Background/Aim Steroidal mineralocorticoid receptor antagonists (MRAs) are effective in the treatment of kidney disease; however, the side effect of hyperkalaemia, particularly in the context of renal impairment, is a major limitation to their clinical use. Recently developed non-steroidal MRAs have distinct characteristics suggesting that they may be superior to steroidal MRAs. Therefore, we explored the benefits of a non-steroidal MRA in a model of rapidly progressive glomerulonephritis. Methods Accelerated anti-glomerular basement membrane (GBM) glomerulonephritis was induced in groups of C57BL/6J mice which received no treatment, vehicle or a non-steroidal MRA (BR-4628, 5mg/kg/bid) from day 0 until being killed on day 15 of disease. Mice were examined for renal injury. Results Mice with anti-GBM glomerulonephritis which received no treatment or vehicle developed similar disease with severe albuminuria, impaired renal function, glomerular tuft damage and crescents in 40% of glomeruli. In comparison, mice which received BR-4628 displayed similar albuminuria, but had improved renal function, reduced severity of glomerular tuft lesions and a 50% reduction in crescents. The protection seen in BR-4628 treated mice was associated with a marked reduction in glomerular macrophages and T-cells and reduced kidney gene expression of proinflammatory (CCL2, TNF-α, IFN-γ) and profibrotic molecules (collagen I, fibronectin). In addition, treatment with BR-4626 did not cause hyperkalaemia or increase urine Na+/K+ excretion (a marker of tubular dysfunction). Conclusions The non-steroidal MRA (BR-4628) provided substantial suppression of mouse crescentic glomerulonephritis without causing tubular dysfunction. This finding warrants further investigation of non-steroidal MRAs as a therapy for inflammatory kidney diseases. PMID:26700873

  14. The Keck OSIRIS Nearby AGN (KONA) Survey: AGN Fueling and Feedback

    NASA Astrophysics Data System (ADS)

    Hicks, Erin K. S.; Müller-Sánchez, Francisco; Malkan, Matthew A.; Yu, Po-Chieh

    In an effort to better constrain the relevant physical processes dictating the co-evolution of supermassive black holes and the galaxies in which they reside we turn to local Seyfert AGN. It is only with these local AGN that we can reach the spatial resolution needed to adequately characterize the inflow and outflow mechanisms thought to be the driving forces in establishing the relationship between black holes and their host galaxies at higher redshift. We present the first results from the KONA (Keck OSIRIS Nearby AGN) survey, which takes advantage of the integral field unit OSIRIS plus laser and natural guide star adaptive optics to probe down to scales of 5-30 parsecs in a sample of 40 local Seyfert galaxies. With these K-band data we measure the two-dimensional distribution and kinematics of the nuclear stars, molecular gas, and ionized gas within the central few hundred parsecs.

  15. Glomerular C3c localization indicates ongoing immune deposit formation and complement activation in experimental glomerulonephritis.

    PubMed Central

    Schulze, M.; Pruchno, C. J.; Burns, M.; Baker, P. J.; Johnson, R. J.; Couser, W. G.

    1993-01-01

    In antibody-mediated glomerular disease, deposits of C3 (C3b) are common and are degraded by factor I to C3c and C3d. However, the kinetics of C3b degradation in glomerulonephritis have not been defined. To do this, we studied three models of complement-dependent glomerulonephritis with established C3 deposits (passive Heymann nephritis, cationized immunoglobulin G membranous nephropathy, and concanavalin A-anticoncanavalin A glomerulonephritis). C3b deposition was halted by administration of cobra venom factor, and the disappearance of C3c and C3d from glomeruli was measured with specific antibodies and quantitative fluorescence densitometry. Results showed that C3c deposits were reduced by over 85% within 24 hours in all three models. C3c clearance was unaffected by site or mechanism of deposit formation. C3d deposits persisted despite lack of ongoing complement activation. In passive Heymann nephritis when disease activity was monitored by urinary C5b-9 excretion, C3c was cleared in parallel with return of urine C5b-9 excretion to normal values. We conclude that glomerular deposits of C3c are cleared within 24 hours of cessation of complement activation. Positive staining for C3 utilizing antibody specific for the C3c portion documents recent complement activation usually reflecting new immune deposit formation. Images Figure 1 Figure 2 Figure 3 PMID:7678717

  16. CCR6 Recruits Regulatory T Cells and Th17 Cells to the Kidney in Glomerulonephritis

    PubMed Central

    Turner, Jan-Eric; Paust, Hans-Joachim; Steinmetz, Oliver M.; Peters, Anett; Riedel, Jan-Hendrik; Erhardt, Annette; Wegscheid, Claudia; Velden, Joachim; Fehr, Susanne; Mittrücker, Hans-Willi; Tiegs, Gisa; Stahl, Rolf A.K.

    2010-01-01

    T cells recruited to the kidney contribute to tissue damage in crescentic and proliferative glomerulonephritides. Chemokines and their receptors regulate T cell trafficking, but the expression profile and functional importance of chemokine receptors for renal CD4+ T cell subsets are incompletely understood. In this study, we observed that renal FoxP3+CD4+ regulatory T cells (Tregs) and IL-17–producing CD4+ T (Th17) cells express the chemokine receptor CCR6, whereas IFNγ-producing Th1 cells are CCR6−. Induction of experimental glomerulonephritis (nephrotoxic nephritis) in mice resulted in upregulation of the only CCR6 ligand, CCL20, followed by T cell recruitment, renal tissue injury, albuminuria, and loss of renal function. CCR6 deficiency aggravated renal injury and increased mortality (from uremia) among nephritic mice. Compared with wild-type (WT) mice, CCR6 deficiency reduced infiltration of Tregs and Th17 cells but did not affect recruitment of Th1 cells in the setting of glomerulonephritis. Adoptive transfer of WT but not CCR6-deficient Tregs attenuated morphologic and functional renal injury in nephritic mice. Furthermore, reconstitution with WT Tregs protected CCR6−/− mice from aggravated nephritis. Taken together, these data suggest that CCR6 mediates renal recruitment of both Tregs and Th17 cells and that the reduction of anti-inflammatory Tregs in the presence of a fully functional Th1 response aggravates experimental glomerulonephritis. PMID:20299360

  17. Hot Dust Obscured Galaxies with Excess Blue Light: Dual AGN or Single AGN Under Extreme Conditions?

    NASA Astrophysics Data System (ADS)

    Assef, R. J.; Walton, D. J.; Brightman, M.; Stern, D.; Alexander, D.; Bauer, F.; Blain, A. W.; Diaz-Santos, T.; Eisenhardt, P. R. M.; Finkelstein, S. L.; Hickox, R. C.; Tsai, C.-W.; Wu, J. W.

    2016-03-01

    Hot dust-obscured galaxies (Hot DOGs) are a population of hyper-luminous infrared galaxies identified by the Wide-field Infrared Survey Explorer (WISE) mission from their very red mid-IR colors, and characterized by hot dust temperatures (T > 60 K). Several studies have shown clear evidence that the IR emission in these objects is powered by a highly dust-obscured active galactic nucleus (AGN) that shows close to Compton-thick absorption at X-ray wavelengths. Thanks to the high AGN obscuration, the host galaxy is easily observable, and has UV/optical colors usually consistent with those of a normal galaxy. Here we discuss a sub-population of eight Hot DOGs that show enhanced rest-frame UV/optical emission. We discuss three scenarios that might explain the excess UV emission: (i) unobscured light leaked from the AGN by reflection over the dust or by partial coverage of the accretion disk; (ii) a second unobscured AGN in the system; or (iii) a luminous young starburst. X-ray observations can help discriminate between these scenarios. We study in detail the blue excess Hot DOG WISE J020446.13-050640.8, which was serendipitously observed by Chandra/ACIS-I for 174.5 ks. The X-ray spectrum is consistent with a single, hyper-luminous, highly absorbed AGN, and is strongly inconsistent with the presence of a secondary unobscured AGN. Based on this, we argue that the excess blue emission in this object is most likely either due to reflection or a co-eval starburst. We favor the reflection scenario as the unobscured star formation rate needed to power the UV/optical emission would be ≳1000 M⊙ yr-1. Deep polarimetry observations could confirm the reflection hypothesis.

  18. HOT DUST OBSCURED GALAXIES WITH EXCESS BLUE LIGHT: DUAL AGN OR SINGLE AGN UNDER EXTREME CONDITIONS?

    SciTech Connect

    Assef, R. J.; Diaz-Santos, T.; Walton, D. J.; Brightman, M.; Stern, D.; Eisenhardt, P. R. M.; Tsai, C.-W.; Alexander, D.; Bauer, F.; Blain, A. W.; Finkelstein, S. L.; Hickox, R. C.; Wu, J. W.

    2016-03-10

    Hot dust-obscured galaxies (Hot DOGs) are a population of hyper-luminous infrared galaxies identified by the Wide-field Infrared Survey Explorer (WISE) mission from their very red mid-IR colors, and characterized by hot dust temperatures (T > 60 K). Several studies have shown clear evidence that the IR emission in these objects is powered by a highly dust-obscured active galactic nucleus (AGN) that shows close to Compton-thick absorption at X-ray wavelengths. Thanks to the high AGN obscuration, the host galaxy is easily observable, and has UV/optical colors usually consistent with those of a normal galaxy. Here we discuss a sub-population of eight Hot DOGs that show enhanced rest-frame UV/optical emission. We discuss three scenarios that might explain the excess UV emission: (i) unobscured light leaked from the AGN by reflection over the dust or by partial coverage of the accretion disk; (ii) a second unobscured AGN in the system; or (iii) a luminous young starburst. X-ray observations can help discriminate between these scenarios. We study in detail the blue excess Hot DOG WISE J020446.13–050640.8, which was serendipitously observed by Chandra/ACIS-I for 174.5 ks. The X-ray spectrum is consistent with a single, hyper-luminous, highly absorbed AGN, and is strongly inconsistent with the presence of a secondary unobscured AGN. Based on this, we argue that the excess blue emission in this object is most likely either due to reflection or a co-eval starburst. We favor the reflection scenario as the unobscured star formation rate needed to power the UV/optical emission would be ≳1000 M{sub ⊙} yr{sup −1}. Deep polarimetry observations could confirm the reflection hypothesis.

  19. AGN Triggering in Kpc-scale Separation Merging Galaxies

    NASA Astrophysics Data System (ADS)

    Comerford, Julia M.

    2017-01-01

    As supermassive black holes in galaxy mergers evolve from Mpc to mpc separations, the kpc-scale separations are pivotal for igniting AGN activity. At these separations the galaxy mergers drive central inflows of gas, which can trigger AGN activity in one or both supermassive black holes, in systems known as offset AGN and dual AGN, respectively. Offset and dual AGN are direct tracers of the connection between galaxy mass growth (via galaxy mergers) and supermassive black hole mass growth (via gas accretion). These systems are also the smallest separation supermassive black hole pairs that have been observationally confirmed, offering the last glimpse of supermassive black hole pair dynamics before gravitational wave emission dominates and drives the coalescence of the supermassive black holes. I will present multiwavelength approaches to building catalogs of offset AGN and dual AGN, and show the results of our observing campaigns with HST, Chandra, VLA, and Keck. Finally, I will discuss what our results show about whether galaxy mergers preferentially fuel the most luminous AGN, which supermassive black hole in a merger is more efficient at accreting gas, and where in a merger the AGN fueling occurs.

  20. AGN physics - A Chandra-Swift Census of AGN activity in Compact Groups

    NASA Astrophysics Data System (ADS)

    Tzanavaris, Panayiotis

    2012-09-01

    We present a missing link in the study of AGN activity in compact groups of galaxies. The level of this activity in compact groups remains controversial, but has only been studied with optical and infrared diagnostics. We present the first systematic study of 40 compact group galaxies in 9 groups, combining Chandra and Swift data, and providing the first X-ray/UV view of galactic nuclei in compact groups. Our results provide independent evidence that the level of AGN activity in compact groups is representative of their unique environment, which is distinct to that of rich clusters and the field.

  1. AGN Luminosity and Stellar Age: Two Missing Ingredients for AGN Unification as Seen with iPTF Supernovae

    NASA Astrophysics Data System (ADS)

    Villarroel, Beatriz; Nyholm, Anders; Karlsson, Torgny; Comerón, Sébastien; Korn, Andreas J.; Sollerman, Jesper; Zackrisson, Erik

    2017-03-01

    Active galactic nuclei (AGNs) are extremely powerful cosmic objects, driven by accretion of hot gas upon super-massive black holes. The zoo of AGN classes is divided into two major groups, with Type-1 AGNs displaying broad Balmer emission lines and Type-2 narrow ones. For a long time it was believed that a Type-2 AGN is a Type-1 AGN viewed through a dusty kiloparsec-sized torus, but an emerging body of observations suggests more than just the viewing angle matters. Here we report significant differences in supernova (SN) counts and classes in the first study to date of SNe near Type-1 and Type-2 AGN host galaxies, using data from the intermediate Palomar Transient Factory, the Sloan Digital Sky Survey Data Release 7, and Galaxy Zoo. We detect many more SNe in Type-2 AGN hosts (size of effect ∼5.1σ) compared to Type-1 hosts, which shows that the two classes of AGN are located inside host galaxies with different properties. In addition, Type-1 and Type-2 AGNs that are dominated by star formation according to Wide-field Infrared Survey Explorer colors {m}W1-{m}W2< 0.5 and are matched in 22 μm absolute magnitude differ by a factor of ten in L[O iii] λ5007 luminosity, suggesting that when residing in similar types of host galaxies Type-1 AGNs are much more luminous. Our results demonstrate two more factors that play an important role in completing the current picture: the age of stellar populations and the AGN luminosity. This has immediate consequences for understanding the many AGN classes and galaxy evolution.

  2. A Case of Anti-Glomerular Basement Membrane Glomerulonephritis Complicated by Type 1 Diabetes Mellitus, Mimicking Urinary Tract Infection

    PubMed Central

    Aoki, Yoshihiro; Tanimoto, Izumi; Miyauchi, Yoshihiro; Suzuki, Yoshio; Shiojiri, Toshiaki

    2017-01-01

    Patient: Female, 44 Final Diagnosis: Anti-glomerular basement membrane glomerulonephritis Symptoms: Fever Medication: — Clinical Procedure: — Specialty: Nephrology Objective: Rare co-existance of disease or pathology Background: Type 1 diabetes mellitus (DM) tends to complicate other autoimmune diseases. When considering renal dysfunction in patients with DM, diabetic nephropathy is a likely diagnosis. By contrast, anti-glomerular basement membrane (GBM) glomerulonephritis, an autoimmune disease, is one cause of rapidly progressive glomerulonephritis. Case Report: We report the case of a 44-year-old woman diagnosed with anti-glomerular basement membrane (GBM) glomerulonephritis. The diagnosis was made on the basis of serological test results and pathological findings of a renal biopsy. Five years before admission, she was diagnosed with type 1 DM. At admission, she presented with a fever, chills, nausea, low back pain, and malaise, which were followed by progressive renal dysfunction. The initial presentation mimicked a urinary tract infection, which delayed the correct diagnosis. Conclusions: Our patient’s course strongly suggests that rapidly progressive glomerulonephritis should be considered as an early differential diagnosis in cases of progressive renal dysfunction, especially when accompanied by fever, regardless of the underlying disease. PMID:28344312

  3. [Anti-neutrophil cytoplasmic autoantibody-associated rapid progressive glomerulonephritis complicated with both limited and diffuse scleroderma].

    PubMed

    Miyata, Naoko; Kobayashi, Tomoko; Matsukawa, Yoshihiro; Sawada, Shigemasa; Nishinarita, Susumu; Horie, Takashi

    2002-12-01

    We report two patients with scleroderma, 73-year-old female and 67-year-old female, who developed anti neutrophil cytoplasmic autoantibody (ANCA) associated rapid progressive glomerulonephritis (RPGN). Both patients have had a long history of scleroderma (23 and 14 years, respectively) when ANCA-associated glomerulonephritis occurred. In the first patient, scleroderma was localized in both fingers. She has been followed-up as CREST syndrome rather than systemic sclerosis. The complaints on admission were leg edema and left chest pain in the first patient, and a pyrexia and dyspnea in the second patient. Both patients showed pulmonary manifestation (pleural effusion in the first patient, interstitial pneumonia and alveolar hemorrhage in the second patient, respectively) and rapid progressive glomerulonephritis. Both patients died in spite of corticosteroid therapy. Autopsy findings in the second patient demonstrated crescentic glomerulonephritis and alveolar hemorrhage. Our cases demonstrated that MPO-ANCA associated glomerulonephritis could be associated with limited scleroderma as well as systemic scleroderma. In these condition, the prognosis will be poor if scleroderma seemed to be stable.

  4. Warm Absorber Diagnostics of AGN Dynamics

    NASA Astrophysics Data System (ADS)

    Kallman, Timothy

    Warm absorbers and related phenomena are observable manifestations of outflows or winds from active galactic nuclei (AGN) that have great potential value. Understanding AGN outflows is important for explaining the mass budgets of the central accreting black hole, and also for understanding feedback and the apparent co-evolution of black holes and their host galaxies. In the X-ray band warm absorbers are observed as photoelectric absorption and resonance line scattering features in the 0.5-10 keV energy band; the UV band also shows resonance line absorption. Warm absorbers are common in low luminosity AGN and they have been extensively studied observationally. They may play an important role in AGN feedback, regulating the net accretion onto the black hole and providing mechanical energy to the surroundings. However, fundamental properties of the warm absorbers are not known: What is the mechanism which drives the outflow?; what is the gas density in the flow and the geometrical distribution of the outflow?; what is the explanation for the apparent relation between warm absorbers and the surprising quasi-relativistic 'ultrafast outflows' (UFOs)? We propose a focused set of model calculations that are aimed at synthesizing observable properties of warm absorber flows and associated quantities. These will be used to explore various scenarios for warm absorber dynamics in order to answer the questions in the previous paragraph. The guiding principle will be to examine as wide a range as possible of warm absorber driving mechanisms, geometry and other properties, but with as careful consideration as possible to physical consistency. We will build on our previous work, which was a systematic campaign for testing important class of scenarios for driving the outflows. We have developed a set of tools that are unique and well suited for dynamical calculations including radiation in this context. We also have state-of-the-art tools for generating synthetic spectra, which are

  5. AGN Feedback in Clusters of Galaxies

    DTIC Science & Technology

    2010-01-01

    bubbles created by the radio lobes evacuating regions of the ICM vary widely from a few kpc (e.g. Abell 262 [21, 22]) to hundreds of kpc (e.g. MS0735.6...diameters of approximately 200 kpc . The total energy injection required to inflate the cavities and produce the ob- served shocks is 6 × 1061 erg...cluster center, and these are modeled as shocks in [32] based on the earlier 163 ksec dataset. These features are at 31 and 46 kpc from the AGN and the

  6. Obscured AGN With NuSTAR

    NASA Astrophysics Data System (ADS)

    Marinucci, Andrea; Bianchi, S.; Matt, G.; Balokovic, M.; Bauer, F. E.; Brandt W. N.; Gandhi, P.; Guainazzi, M.; Harrison, F.; Iwasawa, K.; Nicastro, F.; Puccetti, S.; Ricci, C.; Walton, D. J.; Stern, D.

    2016-10-01

    The Nuclear Spectroscopic Telescope Array (NuSTAR) is the first orbiting telescope to focus high energy X-ray light above 10 keV. Compared to the previous generation of coded mask observatories, this change in technology provides NuSTAR with 10x sharper images and 100x improved sensitivityThe unprecedented spectral quality in the 3-80 keV band has provided unique information about the circumnuclear reflecting environment of AGNI will present and discuss results from the NuSTAR observations of nearby Obscured AGN in its first four years of science.

  7. Clues to the Structure of AGN Through Massive Variability Surveys

    NASA Astrophysics Data System (ADS)

    Lawrence, A.

    2016-06-01

    Variability studies hold information on otherwise unresolvable regions in Active Galactic Nuclei (AGN). Population studies of large samples likewise have been very productive for our understanding of AGN. These two themes are coming together in the idea of systematic variability studies of large samples - with SDSS, PanSTARRS, and soon, LSST. I summarise what we have learned about the optical and UV variability of AGN, and what it tells us about accretion discs and the BLR. The most exciting recent results have focused on rare large-scale outbursts and collapses - Tidal Disruption Events, changing-look AGN, and large amplitude microlensing. All of these promise to give us new insight into AGN physics.

  8. Searching for Compton-thick AGN with INTEGRAL

    NASA Astrophysics Data System (ADS)

    Virani, S. N.; Treister, E.; Urry, C. M.; Maccarone, T.; Bird, T.; Beckmann, V.; Lira, P.; Coppi, P.; Uchiyama, Y.

    2005-12-01

    The 30 keV peak in the X-ray background strongly suggests there should be a large number of highly obscured AGN in the local universe. However, the exact number of these objects remains unknown, even though they could nearly double the space density of supermassive black holes. These Compton-thick AGN can be detected in the hard X-rays with INTEGRAL. As part of the current observing cycle, we were awarded 2 Msec to perform INTEGRAL imaging of the XMM-LSS field in order to find highly obscured AGN in the local Universe. In this paper, we present preliminary results for the ˜1 Ms of IBIS data obtained so far, including new hard X-ray detections of AGN. We also present the 20---200 keV spectra of the brightest AGN including the z<0.1 Seyfert galaxies NGC 788, NGC 1068, and NGC 1142.

  9. Does the obscured AGN fraction really depend on luminosity?

    NASA Astrophysics Data System (ADS)

    Sazonov, S.; Churazov, E.; Krivonos, R.

    2015-12-01

    We use a sample of 151 local non-blazar active galactic nuclei (AGN) selected from the INTEGRAL all-sky hard X-ray survey to investigate if the observed declining trend of the fraction of obscured (i.e. showing X-ray absorption) AGN with increasing luminosity is mostly an intrinsic or selection effect. Using a torus-obscuration model, we demonstrate that in addition to negative bias, due to absorption in the torus, in finding obscured AGN in hard X-ray flux-limited surveys, there is also positive bias in finding unobscured AGN, due to Compton reflection in the torus. These biases can be even stronger taking into account plausible intrinsic collimation of hard X-ray emission along the axis of the obscuring torus. Given the AGN luminosity function, which steepens at high luminosities, these observational biases lead to a decreasing observed fraction of obscured AGN with increasing luminosity even if this fraction has no intrinsic luminosity dependence. We find that if the central hard X-ray source in AGN is isotropic, the intrinsic (i.e. corrected for biases) obscured AGN fraction still shows a declining trend with luminosity, although the intrinsic obscured fraction is significantly larger than the observed one: the actual fraction is larger than ˜85 per cent at L ≲ 1042.5 erg s-1 (17-60 keV), and decreases to ≲60 per cent at L ≳ 1044 erg s-1. In terms of the half-opening angle θ of an obscuring torus, this implies that θ ≲ 30° in lower luminosity AGN, and θ ≳ 45° in higher luminosity ones. If, however, the emission from the central supermassive black hole is collimated as dL/dΩ ∝ cos α, the intrinsic dependence of the obscured AGN fraction is consistent with a luminosity-independent torus half-opening angle θ ˜ 30°.

  10. The Prevalence of Gas Outflows in Type 2 AGNs

    NASA Astrophysics Data System (ADS)

    Woo, Jong-Hak; Bae, Hyun-Jin; Son, Donghoon; Karouzos, Marios

    2016-02-01

    To constrain the nature and fraction of the ionized gas outflows in active galactic nuclei (AGNs), we perform a detailed analysis on gas kinematics as manifested by the velocity dispersion and shift of the [{{O}}\\{{III}}] λ5007 emission line, using a large sample of ˜39,000 type 2 AGNs at z < 0.3. First, we confirm a broad correlation between [{{O}} {{III}}] and stellar velocity dispersions, indicating that the bulge gravitational potential plays a main role in determining the [{{O}} {{III}}] kinematics. However, [{{O}} {{III}}] velocity dispersion is on average larger than stellar velocity dispersion by a factor of 1.3-1.4 for AGNs with double Gaussian [{{O}} {{III}}], suggesting that the non-gravitational component, i.e., outflows, is almost comparable to the gravitational component. Second, the increase of the [{{O}} {{III}}] velocity dispersion (after normalized by stellar velocity dispersion) with both AGN luminosity and Eddington ratio suggests that non-gravitational kinematics are clearly linked to AGN accretion. The distribution in the [{{O}} {{III}}] velocity-velocity dispersion diagram dramatically expands toward large values with increasing AGN luminosity, implying that the launching velocity of gas outflows increases with AGN luminosity. Third, the majority of luminous AGNs present the non-gravitational kinematics in the [{{O}} {{III}}] profile. These results suggest that ionized gas outflows are prevalent among type 2 AGNs. On the other hand, we find no strong trend of the [{{O}} {{III}}] kinematics with radio luminosity, once we remove the effect of the bulge gravitational potential, indicating that ionized gas outflows are not directly related to radio activity for the majority of type 2 AGNs.

  11. A UV to mid-IR study of AGN selection

    SciTech Connect

    Chung, Sun Mi; Kochanek, Christopher S.; Assef, Roberto; Brown, Michael J. I.; Stern, Daniel; Jannuzi, Buell T.; Gonzalez, Anthony H.; Hickox, Ryan C.; Moustakas, John

    2014-07-20

    We classify the spectral energy distributions (SEDs) of 431,038 sources in the 9 deg{sup 2} Boötes field of the NOAO Deep Wide-Field Survey (NDWFS). There are up to 17 bands of data available per source, including ultraviolet (GALEX), optical (NDWFS), near-IR (NEWFIRM), and mid-infrared (IRAC and MIPS) data, as well as spectroscopic redshifts for ∼20,000 objects, primarily from the AGN and Galaxy Evolution Survey. We fit galaxy, active galactic nucleus (AGN), stellar, and brown dwarf templates to the observed SEDs, which yield spectral classes for the Galactic sources and photometric redshifts and galaxy/AGN luminosities for the extragalactic sources. The photometric redshift precision of the galaxy and AGN samples are σ/(1 + z) = 0.040 and σ/(1 + z) = 0.169, respectively, with the worst 5% outliers excluded. On the basis of the χ{sub ν}{sup 2} of the SED fit for each SED model, we are able to distinguish between Galactic and extragalactic sources for sources brighter than I = 23.5 mag. We compare the SED fits for a galaxy-only model and a galaxy-AGN model. Using known X-ray and spectroscopic AGN samples, we confirm that SED fitting can be successfully used as a method to identify large populations of AGNs, including spatially resolved AGNs with significant contributions from the host galaxy and objects with the emission line ratios of 'composite' spectra. We also use our results to compare with the X-ray, mid-IR, optical color, and emission line ratio selection techniques. For an F-ratio threshold of F > 10, we find 16,266 AGN candidates brighter than I = 23.5 mag and a surface density of ∼1900 AGN deg{sup –2}.

  12. T cells, adhesion molecules and modulation of apoptosis in visceral leishmaniasis glomerulonephritis

    PubMed Central

    2010-01-01

    Background Immune complex deposition is the accepted mechanism of pathogenesis of VL glomerulopathy however other immune elements may participate. Further in the present study, no difference was seen between immunoglobulin and C3b deposit intensity in glomeruli between infected and non-infected dogs thus T cells, adhesion molecules and parameters of proliferation and apoptosis were analysed in dogs with naturally acquired VL from an endemic area. The dog is the most important domestic reservoir of the protozoa Leishmania (L.) chagasi that causes visceral leishmaniasis (VL). The similarity of VL manifestation in humans and dogs renders the study of canine VL nephropathy of interest with regard to human pathology. Methods From 55 dogs with VL and 8 control non-infected dogs from an endemic area, kidney samples were analyzed by immunohistochemistry for immunoglobulin and C3b deposits, staining for CD4+ and CD8+ T cells, ICAM-1, P-selectin and quantified using morphometry. Besides proliferation marker Ki-67, apoptosis markers M30 and TUNEL staining, and related cytokines TNF-α, IL-1α were searched and quantified. Results We observed similar IgG, IgM and IgA and C3b deposit intensity in dogs with VL and non-infected control dogs. However we detected the Leishmania antigen in cells in glomeruli in 54, CD4+ T cells in the glomeruli of 44, and CD8+ T cells in 17 of a total of 55 dogs with VL. Leishmania antigen was absent and T cells were absent/scarse in eight non-infected control dogs. CD 4+ T cells predominate in proliferative patterns of glomerulonephritis, however the presence of CD4+ and CD8+ T cells were not different in intensity in different patterns of glomerulonephritis. The expression of ICAM-1 and P-selectin was significantly greater in the glomeruli of infected dogs than in control dogs. In all patterns of glomerulonephritis the expression of ICAM-1 ranged from minimum to moderately severe and P-selectin from absent to severe. In the control animals the

  13. The jet-disc connection in AGN

    NASA Astrophysics Data System (ADS)

    Sbarrato, T.; Padovani, P.; Ghisellini, G.

    2014-11-01

    We present our latest results on the connection between accretion rate and relativistic jet power in active galactic nuclei (AGN), by using a large sample which includes mostly blazars, but contains also some radio galaxies. The jet power can be traced by γ-ray luminosity in the case of blazars, and radio luminosity for both classes. The accretion-disc luminosity is instead traced by the broad emission lines. Among blazars, we find a correlation between broad line emission and the γ-ray or radio luminosities, suggesting a direct tight connection between jet power and accretion rate. We confirm that the observational differences between blazar subclasses reflect differences in the accretion regime, but with blazars only we cannot properly access the low-accretion regime. By introducing radio galaxies, we succeed in observing the fingerprint of the transition between radiatively efficient and inefficient accretion discs in the jetted AGN family. The transition occurs at the standard critical value Ld/LEdd ˜ 10-2 and it appears smooth. Below this value, the ionizing luminosity emitted by the accretion structure drops significantly.

  14. Extremely efficient Zevatron in rotating AGN magnetospheres

    NASA Astrophysics Data System (ADS)

    Osmanov, Z.; Mahajan, S.; Machabeli, G.; Chkheidze, N.

    2014-12-01

    A novel model of particle acceleration in the magnetospheres of rotating active galactic nuclei (AGN) is constructed. The particle energies may be boosted up to 1021 eV in a two-step mechanism: in the first stage, the Langmuir waves are centrifugally excited and amplified by means of a parametric process that efficiently pumps rotational energy to excite electrostatic fields. In the second stage, the electrostatic energy is transferred to particle kinetic energy via Landau damping made possible by rapid `Langmuir collapse'. The time-scale for parametric pumping of Langmuir waves turns out to be small compared to the kinematic time-scale, indicating high efficiency of the first process. The second process of `Langmuir collapse' - the creation of caverns or low-density regions - also happens rapidly for the characteristic parameters of the AGN magnetosphere. The Langmuir collapse creates appropriate conditions for transferring electric energy to boost up already high particle energies to much higher values. It is further shown that various energy loss mechanism are relatively weak, and do not impose any significant constraints on maximum achievable energies.

  15. Glomerular common gamma chain confers B- and T-cell-independent protection against glomerulonephritis.

    PubMed

    Luque, Yosu; Cathelin, Dominique; Vandermeersch, Sophie; Xu, Xiaoli; Sohier, Julie; Placier, Sandrine; Xu-Dubois, Yi-Chun; Louis, Kevin; Hertig, Alexandre; Bories, Jean-Christophe; Vasseur, Florence; Campagne, Fabien; Di Santo, James P; Vosshenrich, Christian; Rondeau, Eric; Mesnard, Laurent

    2017-01-19

    Crescentic glomerulonephritis is a life-threatening renal disease that has been extensively studied by the experimental anti-glomerular basement membrane glomerulonephritis (anti-GBM-GN) model. Although T cells have a significant role in this model, athymic/nude mice and rats still develop severe renal disease. Here we further explored the contribution of intrinsic renal cells in the development of T-cell-independent GN lesions. Anti-GBM-GN was induced in three strains of immune-deficient mice (Rag2(-/-), Rag2(-/-)Il2rg(-/-), and Rag2(-/-)Il2rb(-/-)) that are devoid of either T/B cells or T/B/NK cells. The Rag2(-/-)Il2rg(-/-) or Rag2(-/-)Il2rb(-/-) mice harbor an additional deletion of either the common gamma chain (γC) or the interleukin-2 receptor β subunit (IL-2Rβ), respectively, impairing IL-15 signaling in particular. As expected, all these strains developed severe anti-GBM-GN. Additionally, bone marrow replenishment experiments allowed us to deduce a protective role for the glomerular-expressed γC during anti-GBM-GN. Given that IL-15 has been found highly expressed in nephritic kidneys despite the absence of lymphocytes, we then studied this cytokine in vitro on primary cultured podocytes from immune-deficient mice (Rag2(-/-)Il2rg(-/-) and Rag2(-/-)Il2rb(-/-)) compared to controls. IL-15 induced downstream activation of JAK1/3 and SYK in primary cultured podocytes. IL-15-dependent JAK/SYK induction was impaired in the absence of γC or IL-2Rβ. We found γC largely induced on podocytes during human glomerulonephritis. Thus, renal lesions are indeed modulated by intrinsic glomerular cells through the γC/IL-2Rβ receptor response, to date classically described only in immune cells.

  16. Curcumin alleviates immune-complex-mediated glomerulonephritis in factor-H-deficient mice

    PubMed Central

    Jacob, Alexander; Chaves, Lee; Eadon, Michael T; Chang, Anthony; Quigg, Richard J; Alexander, Jessy J

    2013-01-01

    Complement factor H (Cfh) is a key regulator of the complement cascade and protects C57BL/6 mice from immune complex-mediated complement-dependent glomerulonephritis. In chronic serum sickness (CSS) there are increased deposits of immune complexes in the glomeruli with inflammation and a scarring phenotype. As cucurmin is an effective anti-inflammatory agent and reduces complement activation, we hypothesized that it should alleviate renal disease in this setting. To determine the effectiveness of curcumin, an apoferritin-induced CSS model in Cfh-deficient (Cfh−/−) mice was used. Curcumin treatment (30 mg/kg) given every day in parallel with apoferritin reduced glomerulonephritis and enhanced kidney function (blood urea nitrogen, 45·4 ± 7·5 versus 35·6 ± 5·1; albuminuria, 50·1 ± 7·1 versus 15·7 ± 7·1; glomerulonephritis, 2·62 + 0·25 versus 2 + 0·3, P < 0·05). In line with reduced IgG deposits in mice with CSS given curcumin, C9 deposits were reduced indicating reduced complement activation. Mice treated with curcumin had a significant reduction in the number of splenic CD19+ B cells and the ratio of CD19 : CD3 cells (P < 0·05) with no change in the T-cell population. Myeloperoxidase assay showed reduced macrophages in the kidney. However, a significant reduction in the M2 subset of splenic macrophages by apoferritin was prevented by curcumin, suggesting a protective function. Curcumin treatment reduced mRNA expression of inflammatory proteins monocyte chemoattractant protein-1 and transforming growth factor-β and matrix proteins, fibronectin, laminin and collagen. Our results clearly illustrate that curcumin reduces glomerulosclerosis, improves kidney function and could serve as a therapeutic agent during serum sickness. PMID:23347386

  17. Curcumin alleviates immune-complex-mediated glomerulonephritis in factor-H-deficient mice.

    PubMed

    Jacob, Alexander; Chaves, Lee; Eadon, Michael T; Chang, Anthony; Quigg, Richard J; Alexander, Jessy J

    2013-07-01

    Complement factor H (Cfh) is a key regulator of the complement cascade and protects C57BL/6 mice from immune complex-mediated complement-dependent glomerulonephritis. In chronic serum sickness (CSS) there are increased deposits of immune complexes in the glomeruli with inflammation and a scarring phenotype. As cucurmin is an effective anti-inflammatory agent and reduces complement activation, we hypothesized that it should alleviate renal disease in this setting. To determine the effectiveness of curcumin, an apoferritin-induced CSS model in Cfh-deficient (Cfh(-/-)) mice was used. Curcumin treatment (30 mg/kg) given every day in parallel with apoferritin reduced glomerulonephritis and enhanced kidney function (blood urea nitrogen, 45·4 ± 7·5 versus 35·6 ± 5·1; albuminuria, 50·1 ± 7·1 versus 15·7 ± 7·1; glomerulonephritis, 2·62 + 0·25 versus 2 + 0·3, P < 0·05). In line with reduced IgG deposits in mice with CSS given curcumin, C9 deposits were reduced indicating reduced complement activation. Mice treated with curcumin had a significant reduction in the number of splenic CD19(+) B cells and the ratio of CD19 : CD3 cells (P < 0·05) with no change in the T-cell population. Myeloperoxidase assay showed reduced macrophages in the kidney. However, a significant reduction in the M2 subset of splenic macrophages by apoferritin was prevented by curcumin, suggesting a protective function. Curcumin treatment reduced mRNA expression of inflammatory proteins monocyte chemoattractant protein-1 and transforming growth factor-β and matrix proteins, fibronectin, laminin and collagen. Our results clearly illustrate that curcumin reduces glomerulosclerosis, improves kidney function and could serve as a therapeutic agent during serum sickness.

  18. Erythropoietin-producing cells in the liver of ICR-derived glomerulonephritis (ICGN) mice.

    PubMed

    Yamaguchi-Yamada, Misuzu; Akashi, Naotsugu; Goto, Yasufumi; Anan, Sayuri; Yamamoto, Yoshie; Ogura, Atsuo; Manabe, Noboru

    2006-01-01

    The ICR-derived glomerulonephritis (ICGN) mouse is an appropriate model for anemia associated with chronic renal disorder (CRD). Insufficient renal production of erythropoietin (EPO) induces the anemia associated with CRD. EPO mRNA is expressed in both kidneys and liver of progressing-stage ICGN mice. Hypoxic stimulation induced the EPO mRNA expression in the liver as well as in the kidneys of ICGN mice. The localization of EPO-producing cells in the liver remains controversial. Present study using an amplified in situ hybridization technique identified that nonparenchymal cells were the source of hepatic EPO production in ICGN mice under both normoxia and hypoxia.

  19. Clinical spectrum and outcomes of crescentic glomerulonephritis: A single center experience.

    PubMed

    Rampelli, S K; Rajesh, N G; Srinivas, B H; Harichandra Kumar, K T; Swaminathan, R P; Priyamvada, P S

    2016-01-01

    There is limited data on the etiology, clinical and histopathological spectrum and outcomes of crescentic glomerulonephritis (CrGN) in adult Indian population. This prospective study was done to evaluate the etiology, clinicohistological patterns and predictors of outcome of CrGN in South Indian population. All the patients received standard protocol based immunosuppression in addition to supportive care. Immune-complex glomerulonephritis (ICGN) was the most common etiology (n = 31; 77.5%) followed by pauci-immune glomerulonephritis (PauciGN; n = 8; 20%) and anti-glomerular basement membrane disease (n = 1; 2.5%). The most common etiology of ICGN was IgA nephropathy (n = 11; 27.5%) followed by lupus nephritis (n = 7; 17.5%) and post-infectious glomerulonephritis (PIGN) (n = 7; 17.5%). The patients with PauciGN were significantly older compared to those with ICGN (44.5 ± 15 years vs. 31.8 ± 11 years; P = 0.01). The patients with PauciGN presented with significantly higher serum creatinine (9.7 ± 4.4 vs. 6.6 ± 3.3 mg/dl; P = 0.03). The histopathologic parameters of ICGN and PauciGN were comparable except for a higher proportion of sclerosed glomeruli in ICGN. At the end of 3 months follow-up, only two patients went into complete remission (5.4%). Majority of the patients had end-stage renal failure (48.6%) and were dialysis dependent and seven patients (18.9%) expired. There was no signifi difference in the renal survival (10.9 ± 1.9 vs. 9.6 ± 3.3 months) or patient survival (17.5 ± 2.1 vs. 17.3 ± 4.3 months). The parameters associated with adverse outcomes at 3 months were hypertension (odds ratio [OR]: 0.58; confidence interval [CI]: 0.36-0.94), need for renal replacement therapy (OR: 0.19; CI: 0.04-0.9), serum creatinine at admission (P = 0.019), estimated glomerular filtration rate (P = 0.022) and percentage of fibrocellular crescents (P = 0.022).

  20. Hydralazine-induced pauci-immune glomerulonephritis: intriguing case series with misleading diagnoses

    PubMed Central

    Babar, Faizan; Posner, Jeffery N.; Obah, Eugene A.

    2016-01-01

    Hydralazine has been used since the 1950s for the management of hypertension. Evidence for hydralazine-associated vasculitis dates to pre-ANCA (antineutrophil cytoplasmic antibodies) era. This abstract describes two cases of ANCA-positive pauci-immune glomerulonephritis (GN) in challenging scenarios where diagnosis was misconstrued. A comprehensive literature review was done to understand the pathogenesis of drug-induced pauci-immune GN. We have described key diagnostic features that are helpful in distinguishing idiopathic ANCA vasculitis from drug-induced vasculitis. Additionally, we have also described different treatments meant to provide therapy options with the least side effects. PMID:27124161

  1. Hydralazine-induced pauci-immune glomerulonephritis: intriguing case series with misleading diagnoses.

    PubMed

    Babar, Faizan; Posner, Jeffery N; Obah, Eugene A

    2016-01-01

    Hydralazine has been used since the 1950s for the management of hypertension. Evidence for hydralazine-associated vasculitis dates to pre-ANCA (antineutrophil cytoplasmic antibodies) era. This abstract describes two cases of ANCA-positive pauci-immune glomerulonephritis (GN) in challenging scenarios where diagnosis was misconstrued. A comprehensive literature review was done to understand the pathogenesis of drug-induced pauci-immune GN. We have described key diagnostic features that are helpful in distinguishing idiopathic ANCA vasculitis from drug-induced vasculitis. Additionally, we have also described different treatments meant to provide therapy options with the least side effects.

  2. Membranous glomerulonephritis and cellular crescents induced by levamisole-adulterated cocaine abuse: a case report

    PubMed Central

    Moll-Guillen, Jose-Luis; Espí-Reig, Jordi; Blanes-Julia, Marino; García-Martínez, Ana-María; Pujol-Marco, Conrad; Hernández-Jaras, Julio

    2015-01-01

    Levamisole is illicitly employed as a cocaine adulterant. The consumption of levamisole-adulterated cocaine can provoke anti-neutrophil cytoplasmic antibody (ANCA)-associated syndromes. Patients carrying an HLAB27 allele are known to be at higher risk of developing agranulocytosis when treated with levamisole. Likewise, patients with ANCA-associated vasculitis (AAV) and internal organ involvement have typically been exposed to offending agents for prolonged periods of time, often on the order of years. Here, we report an unusual case of a patient in which kidney biopsy showed membranous glomerulonephritis with cellular crescents associated with levamisole-contaminated cocaine use. PMID:26605317

  3. Progeria with post-streptococcal glomerulonephritis: a rare case report with differential diagnosis.

    PubMed

    Sebastian, Alphy A; Ahsan, Auswaf K

    2013-02-01

    Hutchinson-Gilford progeria syndrome is a rare autosomal dominant disorder associated with skin fragility. It is characterized by craniofacial disproportion, delayed dentition, micrognathia, and plucked bird appearance. The genetic defect is mainly de nova mutation in the lamin A gene. This report describes a 16-year-old patient with classical features of progeria along with post-streptococcal glomerulonephritis. The symptoms of hepatomegaly were also present in the patient. The differential diagnoses of this lesion are also discussed in detail in this literature.

  4. Crescentic Glomerulonephritis in IgA Multiple Myeloma: A Case Report

    PubMed Central

    Moscoso-Solorzano, Grace T.; Madureira-Silva, Marcus V.; Balda, Carlos; Franco, Marcello F.; Mastroianni-Kirsztajn, Gianna

    2011-01-01

    Background There are few reports of glomerulonephritis (GN) with crescents and a rapidly progressive course that lead to a diagnosis of a previously unsuspected B-cell dyscrasia. Case Presentation: We report a case of rapidly progressive GN: the patient showed no evidence of etiology at the time of biopsy and was diagnosed as IgA multiple myeloma (MM) during investigation based on a renal biopsy. He presented diffuse proliferative and exudative GN and marked plasma cell infiltration of the kidney. Conclusion The present case raises the possibility that proliferative GN with crescents may be a rare mode of presentation of MM. PMID:22470380

  5. Glomerulonephritis associated with simultaneous canine adenovirus-1 and Dirofilaria immitis infection in a dog.

    PubMed

    Sánchez-Cordón, P J; Salguero, F J; Núnez, A; Gómez-Villamandos, J C; Carrasco, L

    2002-06-01

    This article describes a case of glomerulonephritis and immunocomplex (IgM, IgG and C3c) deposition in the mesangium and basement membranes of a 2-year-old dog with canine viral hepatitis and dirofilariasis. The deposits observed in the mesangium were in the vicinity of cells with viral replication. However, no clear relationship was found between viral replication and the deposition of immunocomplexes in the glomerular capillary basement membranes, which may be the reason why these deposits have only been tentatively related to the concomitant infestation by Dirofilaria immitis.

  6. Tonsillar Kaposi sarcoma in a patient with membranous glomerulonephritis on immunosuppressive therapy.

    PubMed

    Al-Brahim, Nabeel; Zaki, Ashraf H; El-Merhi, Khaled; Ahmad, Mahmoud S

    2013-07-01

    Kaposi sarcoma is a malignant vascular neoplasm uncommonly seen in immunosuppressed patients. Herein we report an unusual case of tonsillar Kaposi sarcoma in a patient with membranous glomerulonephritis treated with prednisolone and cyclosporine. The patient presented after 10 months of starting the treatment with a tonsillar mass. Histological examination was typical of monomorphic spindle cell proliferation with slit-like vascular channels. The tumor cells expressed CD34, D2-40 and positive nuclear stain for HHV-8. Kaposi sarcoma is associated with immunosuppression and rarely occurs in the tonsil. Clinicians should be aware of this rare presentation of Kaposi sarcoma.

  7. Mini-Survey on SDSS OIII AGN with Swift

    NASA Technical Reports Server (NTRS)

    Angelini, Lorella

    2008-01-01

    The number of AGN and their luminosity distribution are crucial parameters for our understanding of the AGN phenomenon. There is a common wisdom that every massive galaxy has a massive black hole. However, most of these objects either are not radiating or until recently have been very difficult to detect. The Sloan Digital Sky Survey (SDSS) data, based on the [OIII] line indicate that perhaps up to 20% of all galaxies may be classified as AGN a surprising result that must be checked with independent data. X-ray surveys have revealed that hard X-ray selected AGN show a strong luminosity dependent evolution and their luminosity function (LF) shows a dramatic break towards low $L_X$ (at all $z$). This is seen for all types of AGN, but is stronger for the broad-line objects. In sharp contrast, the local LF of {it optically-selected samples} shows no such break and no differences between narrow and broad-line objects. Assuming both hard X-ray and [O{\\sc iii}] emission are fair indicators of AGN activity, it is important to understand this discrepancy. We present here the results of a min-survey done with Swift on a selected sample of SDSS selected AGN. The objects have been sampled at different L([O{\\sc iii}]) to check the relation with the $L_X$ observed with Swift.

  8. Spectral decomposition of broad-line agns and host galaxies

    SciTech Connect

    Vanden Berk, Daniel E.; Shen, Jiajian; Yip, Ching-Wa; Schneider, Donald P.; Connolly, Andrew J.; Burton, Ross E.; Jester, Sebastian; Hall, Patrick B.; Szalay, Alex S.; Brinkmann, John; /Apache Point Observ.

    2005-09-01

    Using an eigenspectrum decomposition technique, we separate the host galaxy from the broad line active galactic nucleus (AGN) in a set of 4666 spectra from the Sloan Digital Sky Survey (SDSS), from redshifts near zero up to about 0.75. The decomposition technique uses separate sets of galaxy and quasar eigenspectra to efficiently and reliably separate the AGN and host spectroscopic components. The technique accurately reproduces the host galaxy spectrum, its contributing fraction, and its classification. We show how the accuracy of the decomposition depends upon S/N, host galaxy fraction, and the galaxy class. Based on the eigencoefficients, the sample of SDSS broad-line AGN host galaxies spans a wide range of spectral types, but the distribution differs significantly from inactive galaxies. In particular, post-starburst activity appears to be much more common among AGN host galaxies. The luminosities of the hosts are much higher than expected for normal early-type galaxies, and their colors become increasingly bluer than early-type galaxies with increasing host luminosity. Most of the AGNs with detected hosts are emitting at between 1% and 10% of their estimated Eddington luminosities, but the sensitivity of the technique usually does not extend to the Eddington limit. There are mild correlations among the AGN and host galaxy eigencoefficients, possibly indicating a link between recent star formation and the onset of AGN activity. The catalog of spectral reconstruction parameters is available as an electronic table.

  9. Disentangling AGN and Star Formation in Soft X-Rays

    NASA Technical Reports Server (NTRS)

    LaMassa, Stephanie M.; Heckman, T. M.; Ptak, A.

    2012-01-01

    We have explored the interplay of star formation and active galactic nucleus (AGN) activity in soft X-rays (0.5-2 keV) in two samples of Seyfert 2 galaxies (Sy2s). Using a combination of low-resolution CCD spectra from Chandra and XMM-Newton, we modeled the soft emission of 34 Sy2s using power-law and thermal models. For the 11 sources with high signal-to-noise Chandra imaging of the diffuse host galaxy emission, we estimate the luminosity due to star formation by removing the AGN, fitting the residual emission. The AGN and star formation contributions to the soft X-ray luminosity (i.e., L(sub x,AGN) and L(sub x,SF)) for the remaining 24 Sy2s were estimated from the power-law and thermal luminosities derived from spectral fitting. These luminosities were scaled based on a template derived from XSINGS analysis of normal star-forming galaxies. To account for errors in the luminosities derived from spectral fitting and the spread in the scaling factor, we estimated L(sub x,AGN) and L(sub x,SF))from Monte Carlo simulations. These simulated luminosities agree with L(sub x,AGN) and L(sub x,SF) derived from Chandra imaging analysis within a 3sigma confidence level. Using the infrared [Ne ii]12.8 micron and [O iv]26 micron lines as a proxy of star formation and AGN activity, respectively, we independently disentangle the contributions of these two processes to the total soft X-ray emission. This decomposition generally agrees with L(sub x,SF) and L(sub x,AGN) at the 3 sigma level. In the absence of resolvable nuclear emission, our decomposition method provides a reasonable estimate of emission due to star formation in galaxies hosting type 2 AGNs.

  10. The Swift AGN and Cluster Survey

    NASA Astrophysics Data System (ADS)

    Danae Griffin, Rhiannon; Dai, Xinyu; Kochanek, Christopher S.; Bregman, Joel N.; Nugent, Jenna

    2016-01-01

    The Swift active galactic nucleus (AGN) and Cluster Survey (SACS) uses 125 deg^2 of Swift X-ray Telescope serendipitous fields with variable depths surrounding X-ray bursts to provide a medium depth (4 × 10^-15 erg cm^-2 s^-1) and area survey filling the gap between deep, narrow Chandra/XMM-Newton surveys and wide, shallow ROSAT surveys. Here, we present the first two papers in a series of publications for SACS. In the first paper, we introduce our method and catalog of 22,563 point sources and 442 extended sources. We examine the number counts of the AGN and galaxy cluster populations. SACS provides excellent constraints on the AGN number counts at the bright end with negligible uncertainties due to cosmic variance, and these constraints are consistent with previous measurements. The depth and areal coverage of SACS is well suited for galaxy cluster surveys outside the local universe, reaching z ˜ 1 for massive clusters. In the second paper, we use Sloan Digital Sky Survey (SDSS) DR8 data to study the 203 extended SACS sources that are located within the SDSS footprint. We search for galaxy over-densities in 3-D space using SDSS galaxies and their photometric redshifts near the Swift galaxy cluster candidates. We find 103 Swift clusters with a > 3σ over-density. The remaining targets are potentially located at higher redshifts and require deeper optical follow-up observations for confirmations as galaxy clusters. We present a series of cluster properties including the redshift, BCG magnitude, BCG-to-X-ray center offset, optical richness, X-ray luminosity and red sequences. We compare the observed redshift distribution of the sample with a theoretical model, and find that our sample is complete for z ≤ 0.3 and 80% complete for z ≤ 0.4, consistent with the survey depth of SDSS. We also match our SDSS confirmed Swift clusters to existing cluster catalogs, and find 42, 2 and 1 matches in optical, X-ray and SZ catalogs, respectively, so the majority of these

  11. X-ray-selected AGNs near bright galaxies

    NASA Technical Reports Server (NTRS)

    Stocke, John T.; Schneider, Peter; Morris, Simon L.; Gioia, Isabella M.; Maccacaro, Tommaso

    1987-01-01

    Among the numerous low-redshift low-luminosity X-ray sources discovered with the Einstein Observatory, ten AGNs were identified that are projected within three optical diameters of bright (V less than 18) foreground galaxies. These AGNs near galaxies have significantly higher redshifts than the sample as a whole. This discovery is interpreted in terms of gravitational 'microlensing' in which stars in the foreground galaxy have significantly brightened the X-ray emission from these higher redshift AGNs, allowing their detection. It is suggested that microlensing may be responsible for a significant alteration of the inherent QSO luminosity function.

  12. Vanillic Acid Ameliorates Cationic Bovine Serum Albumin Induced Immune Complex Glomerulonephritis in BALB/c Mice.

    PubMed

    Motiram Kakalij, Rahul; Tejaswini, G; Patil, Madhoosudan A; Dinesh Kumar, B; Diwan, Prakash V

    2016-06-01

    Preclinical Research Vanillic acid (VA) is a dihydroxybenzoic acid derivative widely used as a flavoring agent. It has chemopreventive effects on experimentally-induced carcinogenesis and in ulcerative colitis. The object of the present study was to investigate the effects of VA, alone and in combination with methylprednisolone (MP), on cationic bovine serum albumin (cBSA induced immune-complex glomerulonephritis in female BALB/c mice. Pre-immunization was carried out with cBSA in BALB/c mice and repeated (cBSA, 13 mg/kg, 3 times/week, i.v.) for 6 weeks to induce glomerulonephritis which was confirmed by the presence of severe proteinuria. The effect of VA (50, 100, and 200 mg/kg, p.o.) and its combination with MP (12.5 mg/kg, p.o.) was assessed in the nephrotic disease model. Treatment with VA decreased inflammatory nephrotic injury as evidenced by decreased proteinuria, serum creatinine, blood urea nitrogen, serum IgG1 and TNF-α levels. Co-administration of VA with MP showed an improvement in the immunohistochemistry of glomerular nephrin and podocin. The present results indicate that VA has a nephroprotective effect in the management of autoimmune nephritis. Drug Dev Res 77 : 171-179, 2016.   © 2016 Wiley Periodicals, Inc.

  13. Characterization of the macrophage transcriptome in glomerulonephritis-susceptible and -resistant rat strains.

    PubMed

    Maratou, K; Behmoaras, J; Fewings, C; Srivastava, P; D'Souza, Z; Smith, J; Game, L; Cook, T; Aitman, T

    2011-03-01

    Crescentic glomerulonephritis (CRGN) is a major cause of rapidly progressive renal failure for which the underlying genetic basis is unknown. Wistar-Kyoto (WKY) rats show marked susceptibility to CRGN, whereas Lewis rats are resistant. Glomerular injury and crescent formation are macrophage dependent and mainly explained by seven quantitative trait loci (Crgn1-7). Here, we used microarray analysis in basal and lipopolysaccharide (LPS)-stimulated macrophages to identify genes that reside on pathways predisposing WKY rats to CRGN. We detected 97 novel positional candidates for the uncharacterized Crgn3-7. We identified 10 additional secondary effector genes with profound differences in expression between the two strains (>5-fold change, <1% false discovery rate) for basal and LPS-stimulated macrophages. Moreover, we identified eight genes with differentially expressed alternatively spliced isoforms, by using an in-depth analysis at the probe level that allowed us to discard false positives owing to polymorphisms between the two rat strains. Pathway analysis identified several common linked pathways, enriched for differentially expressed genes, which affect macrophage activation. In summary, our results identify distinct macrophage transcriptome profiles between two rat strains that differ in susceptibility to glomerulonephritis, provide novel positional candidates for Crgn3-7 and define groups of genes that play a significant role in differential regulation of macrophage activity.

  14. Role of the plasma contact system in the pathogenesis of experimental anti-GBM glomerulonephritis.

    PubMed Central

    Villaro, J; Sánchez Ibarrola, A; Purroy, A

    1988-01-01

    To study the participation of the Hageman factor-related contact system of plasma in the pathogenesis of glomerulonephritis (GN), an anti-BM GN was induced in a group of 10 normal Brown Norway rats and another of seven Brown Norway BN/Mai Pfd f rats. The latter strain is characterized by a congenital deficiency of plasma prekallikrein and of high-molecular weight kininogen, with lengthening of the activated partial thromboplastin time. In the deficient group, one animal developed crescents in less than 25% of glomeruli, five in 25-50% and one in 50-75%. In the group of normal rats, extracapillary proliferation was of greater severity: one animal showed crescents in less than 25% of glomeruli, two in 50-75% and five in more than 75% of glomeruli. Although in both groups intense glomerular fibrin deposition was documented, the intensity of these deposits was less severe in the deficient animals. These data suggest, in the first place, that functional integrity of the contact system is not a necessary requirement for glomerular fibrinogenesis, other mechanisms being implicated in this phenomenon. On the other hand, this functional deficit has exerted a protective effect on crescent formation, which suggests that the contact system can play a role as a mediator of injury in glomerulonephritis, perhaps through the release of contact system-dependent mediators of inflammation. PMID:3396222

  15. C3 glomerulonephritis and autoimmune disease: more than a fortuitous association?

    PubMed

    Alexander, Mariam P; Fervenza, Fernando C; De Vriese, An S; Smith, Richard J H; Nasr, Samih H; Cornell, Lynn D; Herrera Hernandez, Loren P; Zhang, Yuzhou; Sethi, Sanjeev

    2016-04-01

    C3 glomerulonephritis (C3GN) results from genetic or acquired dysregulation of the alternative complement pathway. A subset of patients may have clinical and biochemical characteristics compatible with an autoimmune disorder. We studied a cohort of 85 patients with confirmed C3GN (2007-2014), of which ten patients (3 male, 7 female; mean age 38.5 years) had an associated autoimmune disorder. All patients had abnormal ANA titers, 6 also had positive ds-DNA titers. At the time of presentation with C3GN, all 7 female patients had autoimmune-related presentations. Of the 3 male patients, only 1 patient had autoimmune-related presentations. Kidney biopsy showed predominantly mesangial proliferative or membranoproliferative glomerulonephritis. In 5 patients, the alternative pathway was evaluated. All had allele variants/polymorphisms associated with C3GN. One patient was also positive for C3Nefs. Treatment varied form conservative management to the use of prednisone alone or with cytotoxic therapy. Mean serum creatinine decreased from 2.0 to 1.4 mg/dL while proteinuria decreased from 2300 to 994 mg/24 h in 8 patients with follow-up. The study highlights the association between C3GN and autoimmune disorders, particularly in female patients. The study suggests that an autoimmune milieu may act as a trigger for the development of C3GN in genetically susceptible patients. Short-term prognosis of C3GN associated with autoimmune disorders appears excellent.

  16. [The x-ray diagnosis of a predisposition to nephrogenic pulmonary edema in glomerulonephritis patients].

    PubMed

    Kamenetskiĭ, M S; Pervak, M B; Tkachenko, G D; Vernikov, B L

    1995-01-01

    To develop criteria for determining predisposition to pulmonary edema in patients with glomerulonephritis, clinical, laboratory and X-ray examinations were made in 697 patients with glomerulonephritis at different stages of its development. X-ray examination included chest tele X-ray and its densitometric analysis. Twenty two patients underwent computerized tomography with histographic analysis. In 106 patients, X-ray findings were compared with the volume of circulating blood, cardiac and stroke indices. Changes in the lungs and pleural cavities were found in 22.7%, pulmonary edema was revealed in 15.7% of the patients. The prognostically unfavourable criteria for the development of pulmonary edema were found to be Stage II pulmonary venous hypertension with hypervolemia and peripheral edemas. The densitometrically detected increase in the density of the lower lungs in patients with Stage II venous hypertension suggests early manifestations of interstitial edema of the lung and the narrowing of the histogram angle limited by its ascending and descending lines is indicative of the fact that interstitial edema progresses to alveolar one.

  17. A case of multicentric Castleman's disease with membranoproliferative glomerulonephritis type 3-like lesion.

    PubMed

    Nagai, Kei; Usui, Joichi; Noguchi, Kazuyuki; Unai, Kei; Hiwatashi, Akira; Arakawa, Yoh; Togashi, Amane; Morito, Naoki; Saito, Chie; Yoh, Keigyou; Tsuruoka, Syuichi; Kojima, Hiroshi; Aita, Kumi; Nagata, Michio; Yamagata, Kunihiro

    2011-11-01

    Renal involvement is a significant complication of multicentric Castleman's disease (MCD) and various glomerular involvements have been reported. A 45-year-old Japanese man presented with persistent proteinuria, with lymphadenopathy and hypergammaglobulinemia. He had been diagnosed 4 years previously with MCD. As his renal impairment had progressed to renal failure, he underwent a renal biopsy. Histology revealed diffuse and global membranous lesions with large and heterogeneous epimembranous deposits. In addition, mesangial cell proliferation and focal extracapillary lesions were found. Under immunofluorescence, granular staining for anti-IgG, IgG1, IgG2 and IgA was strongly positive in the capillary loop, and weakly positive in the mesangium. As such, there was a diversity of histological features. Our perspective with regard to pathogenesis is that the formation of the immune-complex contributed to the membranoproliferative glomerulonephritis type 3-like lesion. This histological multiform with MCD is valuable for increasing our understanding of the mechanism for onset of immune-complex glomerular deposition and cellular proliferation of glomerulonephritis.

  18. Myeloperoxidase-antineutrophil cytoplasmic antibody-associated crescentic glomerulonephritis in autosomal dominant polycystic kidney disease

    PubMed Central

    2013-01-01

    Background Autosomal dominant polycystic kidney disease (ADPKD) is an inherited disorder that is characterized by the development of cysts in the kidneys and other organs. Urinary protein excretion is usually less than 1 g/day, and ADPKD is rarely associated with nephrotic syndrome or rapidly progressive glomerulonephritis (RPGN). To date, myeloperoxidase (MPO)-antineutrophil cytoplasmic antibody (ANCA)-associated crescentic glomerulonephritis (CrGN) has not been reported in a patient with ADPKD. Case presentations We report two cases of MPO-ANCA positive ADPKD. A 60-year-old Japanese woman (case 1) and a 54-year-old Japanese woman (case 2) presented with RPGN featuring severe proteinuria and microscopic hematuria. In both patients percutaneous needle biopsy of the kidney revealed MPO-ANCA-associated CrGN with a paucity of glomerular immunoglobulin staining. Each patient received intravenous methylprednisolone for 3 days, followed by oral prednisolone. Case 1 showed gradual improvement and has not progressed to end-stage renal disease (ESRD), but case 2 developed ESRD requiring hemodialysis within one month despite treatment. Conclusion These are the first two reported cases of MPO-ANCA-associated CrGN in patients with ADPKD. Our experience suggests that serial measurement of the ANCA titer and renal biopsy should be considered for accurate diagnosis and appropriate treatment of ADPKD patients who present with proteinuria, hematuria, and rapid decline of renal function. PMID:23617397

  19. Accretion-ejection models for AGN jets

    NASA Astrophysics Data System (ADS)

    Zanni, C.

    2008-10-01

    It is likely that jets from Active Galactic Nuclei derive their energy from accretion onto the central black hole. It is actually possible to fuel the jets by extracting energy and angular momentum from the accretion disk and/or the rotating black hole via the action of large-scale magnetic fields. In this talk I will first present results of analytical and numerical models of the launching process of jets from magnetized accretion disks: I will show that, although a sizeable fraction of the accretion power goes into the jets, these outflows are presumably only mildly relativistic. In the second place, I will therefore suggest that the strongly relativistic components observed at the VLBI scales are accelerated in the innermost parts of the AGNs by Blandford-Znajek and/or Compton-rocket processes. Nonetheless, the non-relativistic disk-wind is needed to collimate the relativistic component and to reproduce the total power of extragalactic jets.

  20. AGN warm absorption with the ATHENA

    NASA Astrophysics Data System (ADS)

    Różańska, Agata; Gronkiewicz, Dominik; Hryniewicz, Krzysztof; Adhikari, Tek Prasad; Rataj, Mirosław; Skup, Konrad

    2016-06-01

    X-ray astronomy requires satellites to make progress in searching the distribution of hot matter in the Universe. Approximately 15 years period of time is needed for full construction of the flight instrument from the mission concept up to the launch. A new generation X-ray telescope ATHENA (the Advanced Telescope for High Energy Astrophysics) was approved by European Space Agency as a large mission with a launch foreseen in 2028. In this paper we show how microcalorimeter on the board of ATHENA will help us to study warm absorption observed in active galactic nuclei (AGN). We show that future observations will allow us to identify hundreds of lines from highly ionized elements and to measure Galactic warm absorption with very high precision.

  1. Neutrino radiation of the AGN black holes

    NASA Astrophysics Data System (ADS)

    Ter-Kazarian, G.; Shidhani, S.; Sargsyan, L.

    2007-07-01

    In the framework of ‘microscopic’ theory of black holes (J. Phys. Soc. Jpn. Suppl. B 70, 84, 2001; Astrophys. USSR 4, 659, 1996; 35, 335, 1991, 33, 143, 1990, 31, 345, 1989a; Astrophys. Space Sci. 1, 1992; Dokl. Akad. Nauk USSR 309, 97, 1989b), and references therein, we address the ‘pre-radiation time’ (PRT) of neutrinos from black holes, which implies the lapse of time from black hole’s birth till radiation of an extremely high energy neutrinos. For post-PRT lifetime, the black hole no longer holds as a region of spacetime that cannot communicate with the external universe. We study main features of spherical accretion onto central BH and infer a mass accretion rate onto it, and, further, calculate the resulting PRT versus bolometric luminosity due to accretion onto black hole. We estimate the PRTs of AGN black holes, with the well-determined masses and bolometric luminosities, collected from the literature by Woo Jong-Hak and Urry (Astrophys. J. 579, 530, 2002) on which this paper is partially based. The simulations for the black holes of masses M BH ≃(1.1ṡ106 ÷4.2ṡ109) M ⊙ give the values of PRTs varying in the range of about T BH ≃(4.3ṡ105 ÷5.6ṡ1011) yr. The derived PRTs for the 60 AGN black holes are longer than the age of the universe (˜13.7 Gyr) favored today. At present, some of remaining 174 BHs may radiate neutrinos. However, these results would be underestimated if the reservoir of gas for accretion in the galaxy center is quite modest, and no obvious way to feed the BHs with substantial accretion.

  2. Acute kidney injury in the cancer patient.

    PubMed

    Campbell, G Adam; Hu, Daniel; Okusa, Mark D

    2014-01-01

    Acute kidney injury (AKI) is a frequent and significant complication of cancer and cancer therapy. Cancer patients frequently encounter risk factors for AKI including older age, CKD, prerenal conditions, sepsis, exposure to nephrotoxins, and obstructive physiology. AKI can also be secondary to paraneoplastic conditions, including glomerulonephritis and microangiopathic processes. This complication can have significant consequences, including effects on patients' ability to continue to receive therapy for their malignancy. This review will serve to summarize potential etiologies of AKI that present in patients with cancer as well as to highlight specific patient populations, such as the critically ill cancer patient.

  3. The Role of Star Formation and AGN in Dust Heating of z=0.3-2.8 Galaxies - II. Informing IR AGN Fraction Estimates through Simulations

    NASA Astrophysics Data System (ADS)

    Roebuck, Eric; Sajina, Anna; Hayward, Christopher C.; Pope, Alexandra; Kirkpatrick, Allison; Hernquist, Lars; Yan, Lin

    2016-12-01

    A key question in extragalactic studies is the determination of the relative roles of stars and active galactic nuclei (AGNs) in powering dusty galaxies at z ˜ 1-3 where the bulk of star formation and AGN activity took place. In Paper I, we present a sample of 336 24 μm selected (Ultra)Luminous Infrared Galaxies, (U)LIRGs, at z˜ 0.3-2.8, where we focus on determining the AGN contribution to the IR luminosity. Here, we use hydrodynamic simulations with dust radiative transfer of isolated and merging galaxies to investigate how well the simulations reproduce our empirical IR AGN fraction estimates and determine how IR AGN fractions relate to the UV-mm AGN fraction. We find that: (1) IR AGN fraction estimates based on simulations are in qualitative agreement with the empirical values when host reprocessing of the AGN light is considered; (2) for star-forming galaxy (SFG)-AGN composites our empirical methods may be underestimating the role of AGN, as our simulations imply \\gt 50 % AGN fractions, ˜ 3× higher than previous estimates; (3) 6% of our empirically classified SFGs have AGN fractions ≳50%. While this is a small percentage of SFGs, if confirmed it would imply that the true number density of AGNs may be underestimated; (4) this comparison depends on the adopted AGN template—those that neglect the contribution of warm dust lower the empirical fractions by up to two times; and (5) the IR AGN fraction is only a good proxy for the intrinsic UV-mm AGN fraction when the extinction is high ({A}V≳ 1 or up to and including coalescence in a merger).

  4. AGN STORM: A Leap Forward In Reverberation Mapping

    NASA Astrophysics Data System (ADS)

    Dalla Bontà, Elena; AGN STORM Team

    2016-10-01

    Reverberation mapping is a tomographic technique that can be used to determine the structure and kinematics of the broad- line emitting region at the center of active galactic nuclei. By-products of these investigations are the masses of the central black holes and information about the structure of the accretion disk. I will show some of the most recent results from the AGN Space Telescope and Optical Reverberation Mapping (AGN STORM) project, which was built around 180 daily observations of the bright Seyfert 1 galaxy NGC 5548 with the Cosmic Origins Spectrograph on Hubble Space Telescope. AGN STORM included observations made with Swift, XMM, and several ground-based telescopes, including the 1.22-m telescope at Asiago Observatory. Elena Dalla Bonta` on behalf of the AGN STORM Team.

  5. AGN-selected clusters as revealed by weak lensing

    NASA Technical Reports Server (NTRS)

    Wold, M.; Lacy, M.; Dahle, H.; Lilje, P. B.; Ridgway, S. E.

    2002-01-01

    We discuss the results in light of the cooling flow and the merger/interaction scenarios for triggering and fuelling AGN in clusters, but find that the data do not point unambiguously to neither of the two.

  6. [Follow-up of two patients with mesangial IgA glomerulonephritis exposed to cadmium and organic solvents].

    PubMed

    Fernández, J; Colomé, Jaime Fernández; Sanz-Gallén, P; Sanz-Gallén, Pere; Nogué, S; Xarau, Santiago Nogué

    2010-01-01

    For several years we carried out a follow-up of two patients with IgA mesangial glomerulonephritis with antecedents of exposure to toxic substances (cadmium and organic solvents). The first case involved a 47 year old male who was diagnosed with mesangial IgA glomerulonephritis eight years ago; he had been working for twelve years as a solderer. He had used metal bars containing 25% cadmium as part of the soldering material. Very high levels of cadmium were detected in his blood and urine. The second case involved a 50 year male who was exposed to a wide number of organic dissolvents for 23 years. Three years ago he was diagnosed with a proliferative diffuse mesangial glomerulonephritis with IgA deposits; in spite of that, the patient continued working until one year ago, when was found to have a chronic stage 3 renal disease secondary to IgA nephropathy. Patients diagnosed with mesangial IgA glomerulonephritis should be kept apart from exposure to nephrotoxic substances.

  7. Association of idiopathic retroperitoneal fibrosis, rapidly progressive glomerulonephritis and antiproteinase 3 antineutrophil cytoplasmic antibodies (anti PR3-ANCA).

    PubMed

    Martínez-Odriozola, P; Gutiérrez-Macías, A; Moina Eguren, I; Arrieta Lezama, J

    2008-09-01

    We report a case of idiopathic retroperitoneal fibrosis and rapidly progressive glomerulonephritis with serum antiproteinase 3 antineutrophil cytoplasmic antibodies (anti-PR3-ANCA), without clinical or histological signs of Wegener's granulomatosis, in a 46-year-old man. Our case and previously reported cases showing the same association support the hypothesis that the association is not fortuitous, but reflects a common immunological mechanism.

  8. α-1-Antitrypsin detected by MALDI imaging in the study of glomerulonephritis: Its relevance in chronic kidney disease progression.

    PubMed

    Smith, Andrew; L'Imperio, Vincenzo; De Sio, Gabriele; Ferrario, Franco; Scalia, Carla; Dell'Antonio, Giacomo; Pieruzzi, Federico; Pontillo, Claudia; Filip, Szymon; Markoska, Katerina; Granata, Antonio; Spasovski, Goce; Jankowski, Joachim; Capasso, Giovambattista; Pagni, Fabio; Magni, Fulvio

    2016-06-01

    Idiopathic glomerulonephritis (GN), such as membranous glomerulonephritis, focal segmental glomerulosclerosis (FSGS), and IgA nephropathy (IgAN), represent the most frequent primary glomerular kidney diseases (GKDs) worldwide. Although the renal biopsy currently remains the gold standard for the routine diagnosis of idiopathic GN, the invasiveness and diagnostic difficulty related with this procedure highlight the strong need for new diagnostic and prognostic biomarkers to be translated into less invasive diagnostic tools. MALDI-MS imaging MALDI-MSI was applied to fresh-frozen bioptic renal tissue from patients with a histological diagnosis of FSGS (n = 6), IgAN, (n = 6) and membranous glomerulonephritis (n = 7), and from controls (n = 4) in order to detect specific molecular signatures of primary glomerulonephritis. MALDI-MSI was able to generate molecular signatures capable to distinguish between normal kidney and pathological GN, with specific signals (m/z 4025, 4048, and 4963) representing potential indicators of chronic kidney disease development. Moreover, specific disease-related signatures (m/z 4025 and 4048 for FSGS, m/z 4963 and 5072 for IgAN) were detected. Of these signals, m/z 4048 was identified as α-1-antitrypsin and was shown to be localized to the podocytes within sclerotic glomeruli by immunohistochemistry. α-1-Antitrypsin could be one of the markers of podocyte stress that is correlated with the development of FSGS due to both an excessive loss and a hypertrophy of podocytes.

  9. Multiwavelength Number Counts of AGN in the GOODS Fields

    NASA Astrophysics Data System (ADS)

    Urry, C. M.; Treister, E.; Chatzichristou, E. T.; Van Duyne, J.; Bauer, F. E.; Alexander, D. M.; Koekemoer, A. M.; Moustakas, L. A.; Brandt, W. N.; Grogin, N. A.; Bergeron, J.; Stern, D.; Chary, R.-R.; Conselice, C. J.; Cristiani, S.

    2004-05-01

    We model the X-ray, optical, and far-infrared flux distributions of AGN in the GOODS fields, starting from hard X-ray luminosity functions and spectral energy distributions appropriate to the unified scheme for AGN. The deep optical counts measured from HST ACS images can be well explained by a unified scheme that postulates roughly 3 times as many obscured as unobscured AGN. This scenario is consistent with the observed spectroscopic and photometric redshift distributions of the GOODS AGN once selection effects are considered. The previously reported discrepancy between observed spectroscopic redshift distributions and the predictions of population synthesis models for the X-ray background (which include a similarly large number of obscured AGN) is explained by bias against the most heavily obscured AGN in both X-ray surveys and optical spectroscopic samples. We present the model predictions for the number counts of AGN in the Spitzer MIPS 24 micron and IRAC 3.6-8 micron bands. The GOODS Spitzer observations will verify whether large numbers of obscured AGN are indeed present in the early Universe; these will be very bright far-infrared sources, including some, missed by X-ray observations, that look like ultraluminous infrared galaxies. Based on observations obtained with the NASA/ESA Hubble Space Telescope, which is operated by the Association of Universities for Research in Astronomy (AURA), Inc, under NASA contract NAS5-26555. This work was supported by NASA grants HST-GO-09425(.01-A,.13-A,.26-A); NSF CAREER award AST 99-83783; NASA contract number 1224666 issued by JPL/Caltech under NASA contract 1407; ASI grant I/R/088/02; and a Royal Society University Research Fellowship.

  10. Broad Band Properties of the BAT Selected AGN

    NASA Technical Reports Server (NTRS)

    Mushotzky, Richard; Winter, Lisa; Tueller, jack

    2008-01-01

    We will present the x-ray spectral properties of approximately 150 Burst Alert Telescope (BAT) selected active galactic nuclei (AGN) focusing on the issues of spectral complexity, x-ray absorption and its distribution and that contribution of sources to the x-ray background. If time permits we will also present the nature of the host galaxies of the AGN and their relationship to merger candidates.

  11. Combining Chandra Observations and Near-Infrared Imaging to Search for Dual AGNs Among Double-Peaked [O III] SDSS AGN

    NASA Astrophysics Data System (ADS)

    McGurk, Rosalie C.; Max, Claire E.; Holden, Bradford; Shields, Gregory A.; Medling, Anne

    2016-01-01

    When galaxies merge, gas accretes onto both central supermassive black holes. Thus, one expects to see close pairs of active galactic nuclei (AGNs), or dual AGNs, in a fraction of galaxy mergers. However, finding them remains a challenge. We studied a sample of double-peaked SDSS [O III] AGNs using Keck 2 Laser Guide Star Adaptive Optics assisted imaging to find that 30% of double-peaked SDSS AGNs have two spatial components within a 3" radius. However, the identity of the companion object is not revealed with imaging; X-ray observations can confirm these galaxy pairs as systems containing two AGNs. We performed Chandra X-ray ACIS-S observations on 12 double-peaked candidate dual AGNs with a possible near-infrared companion 1-3" away. Using our observations and 8 archival observations of additional candidate dual AGNs, we compare the distribution of X-ray photons to our spatially double near-IR images, measure X-ray luminosities and hardness ratios, and estimate column densities. Additionally, we can compare our near-IR spatially double candidates with 7 double-peaked [O III] SDSS AGNs that are spatially single in our near-IR imaging and have archival Chandra ACIS-S observations. By assessing what fraction of double- peaked emission line SDSS AGNs are true dual AGNs, we can better determine whether double-peaked [O III] is an efficient dual AGN indicator and constrain the statistics of dual AGNs

  12. Improved characterization of intranight optical variability of prominent AGN classes

    NASA Astrophysics Data System (ADS)

    Goyal, Arti; Gopal-Krishna, Wiita, Paul J.; Stalin, C. S.; Sagar, Ram

    2013-10-01

    The incidence of intranight optical variability (INOV) is known to differ significantly among different classes of powerful active galactic nuclei (AGN). A number of statistical methods have been employed in the literature for testing the presence of INOV in the light curves, sometimes leading to discordant results. In this paper, we compare the INOV characteristics of six prominent classes of AGN, as evaluated using three commonly used statistical tests, namely the χ2-test, the modified C-test and the F-test, which has recently begun to gain popularity. The AGN classes considered are: radio-quiet quasars, radio-intermediate quasars, lobe-dominated quasars, low optical polarization core-dominated quasars, high optical polarization core-dominated quasars and TeV blazars. Our analysis is based on a large body of AGN monitoring data, involving 262 sessions of intranight monitoring of a total 77 AGN, using 1-2 m class optical telescopes located in India. In order to compare the usefulness of the statistical tests, we have also subjected them to a `sanity check' by comparing the number of false positives yielded by each test with the corresponding statistical prediction. The present analysis is intended to serve as a benchmark for future INOV studies of AGN of different classes.

  13. Mini-Survey Of SDSS of [OIII] AGN With Swift

    NASA Technical Reports Server (NTRS)

    Angelini, L.; George, I. M.; Hill, J.; Padgett, C. A.; Mushotzky, R. F.

    2008-01-01

    The number of AGN and their luminosity distribution are crucial parameters for our understanding of the AGN phenomenon. Recent work (e.g. Ferrarese and Merritt 2000) strongly suggests every massive galaxy has a central black hole. However, most of these objects either are not radiating or have been very difficult to detect. We are now in the era of large surveys, and the luminosity function (LF) of AGN has been estimated in various ways. In the X-ray band, Chandra and XMM surveys (e.g., Barger et al. 2005; Hasinger, et al. 2005) have revealed that the LF of Hard X-ray selected AGN shows a strong luminosity-dependent evolution with a dramatic break towards low L(x) (at al z). This is seen for all types of AGN, but is stronger for the broad-line objects (e.g., Steffen et al. 2004). In sharp contrast, the local LF of optically-selected samples shows no such break and no differences between narrow and broad-line objects (Hao et al. 2005). If, as been suggested, hard X-ray and optical emission line can both be fair indicators of AGN activity, it is important to first understand how reliable these characteristics are if we hope to understand the apparent discrepancy in the LFs.

  14. Lyman continuum leaking AGN in the SSA22 field

    NASA Astrophysics Data System (ADS)

    Micheva, Genoveva; Iwata, Ikuru; Inoue, Akio K.

    2017-02-01

    Subaru/SuprimeCam narrow-band photometry of the SSA22 field reveals the presence of four Lyman continuum (LyC) candidates among a sample of 14 active galactic nuclei (AGNs). Two show offsets and likely have stellar LyCin nature or are foreground contaminants. The remaining two LyC candidates are type I AGN. We argue that the average LyC escape fraction of high-redshift, low-luminosity AGN is not likely to be unity, as often assumed in the literature. From direct measurement we obtain the average LyC-to-UV flux density ratio and ionizing emissivity for a number of AGN classes and find it at least a factor of 2 lower than values obtained assuming fesc = 1. Comparing to recent Ly α forest measurements, AGNs at redshift z ˜ 3 make up at most ˜12 per cent and as little as ˜5 per cent of the total ionizing budget. Our results suggest that AGNs are unlikely to dominate the ionization budget of the Universe at high redshifts.

  15. YOUNG AGN OUTBURST RUNNING OVER OLDER X-RAY CAVITIES

    SciTech Connect

    Bogdán, Ákos; Van Weeren, Reinout J.; Kraft, Ralph P.; Forman, William R.; Randall, Scott; Jones, Christine; Giacintucci, Simona; Churazov, Eugene; O'Dea, Christopher P.; Baum, Stefi A.; Noell-Storr, Jacob

    2014-02-20

    Although the energetic feedback from active galactic nuclei (AGNs) is believed to have a profound effect on the evolution of galaxies and clusters of galaxies, details of AGN heating remain elusive. Here, we study NGC 193—a nearby lenticular galaxy—based on X-ray (Chandra) and radio (Very Large Array and Giant Meter-wave Radio Telescope) observations. These data reveal the complex AGN outburst history of the galaxy: we detect a pair of inner X-ray cavities, an outer X-ray cavity, a shock front, and radio lobes extending beyond the inner cavities. We suggest that the inner cavities were produced ∼78 Myr ago by a weaker AGN outburst, while the outer cavity, the radio lobes, and the shock front are due to a younger (13-26 Myr) and 4-8 times more powerful outburst. Combining this with the observed morphology of NGC 193, we conclude that NGC 193 likely represents the first example of a second, more powerful, AGN outburst overrunning an older, weaker outburst. These results help us to understand how the outburst energy is dissipated uniformly in the core of galaxies, and therefore may play a crucial role in resolving how AGN outbursts suppress the formation of large cooling flows at cluster centers.

  16. Young AGN Outburst Running over Older X-Ray Cavities

    NASA Astrophysics Data System (ADS)

    Bogdan, Akos; van Weeren, Reinout Johannes; Kraft, Ralph; Forman, William; Scott, Randall; Giacintucci, Simona; Churazov, Eugene; O'Dea, Christopher; Baum, Stefi; Noell-Storr, Jacob; Jones, Christine

    2015-08-01

    Although the energetic feedback from active galactic nuclei (AGNs) is believed to have a profound effect on the evolution of galaxies and clusters of galaxies, details of AGN heating remain elusive. Here, we study NGC 193 -- a nearby lenticular galaxy in a group -- based on X-ray and radio observations. These data reveal the complex AGN outburst history of the galaxy: we detect a pair of inner X-ray cavities, an outer X-ray cavity, a shock front, and radio lobes extending beyond the inner cavities. We suggest that the inner cavities were produced about 78 Myr ago by a weaker AGN outburst, while the outer cavity, the radio lobes, and the shock front are due to a younger (13-26 Myr) and 4-8 times more powerful outburst. Combining this with the observed morphology of NGC 193, we conclude that NGC 193 likely represents the first example of a second, more powerful, AGN outburst overrunning an older, weaker outburst. These results help us to understand how the outburst energy is dissipated uniformly in the core of galaxies, and therefore may play a crucial role in resolving how AGN outbursts suppress the formation of large cooling flows at cluster centers.

  17. Unwrapping the X-ray Spectra of AGN

    NASA Astrophysics Data System (ADS)

    Reynolds, C.

    2015-07-01

    Active galactic nuclei (AGN) are complex phenomena. At the heart of an AGN is a relativistic accretion disk around the spinning supermassive black hole with a compact, probably pair-regulated, X-ray corona. On larger scales, the outer accretion disk and molecular torus act as the reservoirs of gas for the continuing AGN activity. And on all scales from the black hole outwards, powerful winds (and sometimes jets) are seen and can dominate the source energetics. As I shall review in this talk, each of these components imprints its own characteristic signature into the (time-variable) X-ray spectrum of the AGN. I shall then touch upon a few contemporary topics : (i) the use of new spectral timing techniques for aiding in the decomposition of the spectrum and for probing the geometry of the AGN central engine, (ii) the determination of supermassive black hole spin, (iii) direct confirmation of quasar-mode feedback in some luminous systems. The prospect of AGN observations with Astro-H will be discussed.

  18. Properties and evolution of radio-AGN hosts since z~4

    NASA Astrophysics Data System (ADS)

    Delvecchio, Ivan

    2016-08-01

    We analyse the multi-wavelength properties of about 6200 radio (3-GHz) selected sources in the COSMOS field to investigate the impact of AGN activity on the integrated properties of their hosts. Two main classes of AGN are identified: radiatively-efficient AGN, by combining X-ray, mid-IR diagnostics and SED decomposition, and radiatively-inefficient AGN, that show up only in radio. Interestingly, we find significantly distinct galaxy properties for the two AGN classes, as a function of redshift. At z<2, radiatively-inefficient AGN are typically found in more massive and less star-forming galaxies than radiatively-efficient AGN, while at higher redshift we observe a possible reversal of their stellar mass distributions. We interpret these trends in the context of the anti-hierarchical growth of AGN host galaxies, with a particular focus on the role of AGN feedback over cosmic time in radio-selected samples.

  19. Properties And Evolution Of Radio-AGN Hosts Since z ~ 4

    NASA Astrophysics Data System (ADS)

    Delvecchio, Ivan; Smolčić, V.; Zamorani, G.; Del P. Lagos, C.; Berta, S.; Delhaize, J.; Baran, N.; Alexander, D.; Rosario, D.; et al.

    2016-10-01

    We analyse the multi-wavelength properties of about 7500 radio (3-GHz) selected sources in the COSMOS field to investigate the impact of AGN activity on the integrated properties of their hosts. Two main classes of AGN are identified: radiatively- efficient AGN, by combining X-ray, mid-IR diagnostics and SED decomposition, and radiatively-inefficient AGN, that show up only in radio. Interestingly, we find significantly distinct galaxy properties for the two AGN classes, as a function of redshift. At z<1.5, radiatively-inefficient AGN are typically found in more massive and less star-forming galaxies than radiatively-efficient AGN, while at higher redshift we observe a possible reversal of their stellar mass distributions. We interpret these trends in the context of the anti-hierarchical growth of AGN host galaxies, with a particular focus on the role of AGN feedback over cosmic time in radio-selected samples.

  20. Hiding in plain sight - recovering clusters of galaxies with the strongest AGN in their cores

    NASA Astrophysics Data System (ADS)

    Green, T. S.; Edge, A. C.; Ebeling, H.; Burgett, W. S.; Draper, P. W.; Kaiser, N.; Kudritzki, R.-P.; Magnier, E. A.; Metcalfe, N.; Wainscoat, R. J.; Waters, C.

    2017-03-01

    A key challenge in understanding the feedback mechanism of active galactic nucleus (AGN) in Brightest Cluster Galaxies (BCGs) is the inherent rarity of catching an AGN during its strong outburst phase. This is exacerbated by the ambiguity of differentiating between AGN and clusters in X-ray observations. If there is evidence for an AGN then the X-ray emission is commonly assumed to be dominated by the AGN emission, introducing a selection effect against the detection of AGN in BCGs. In order to recover these 'missing' clusters, we systematically investigate the colour-magnitude relation around some ∼3500 ROSAT All-Sky Survey selected AGN, looking for signs of a cluster red sequence. Amongst our 22 candidate systems, we independently rediscover several confirmed systems, where a strong AGN resides in a central galaxy. We compare the X-ray luminosity to red sequence richness distribution of our AGN candidate systems with that of a similarly selected comparison sample of ∼1000 confirmed clusters and identify seven 'best' candidates (all of which are BL Lac objects), where the X-ray flux is likely to be a comparable mix between cluster and AGN emission. We confirm that the colours of the red sequence are consistent with the redshift of the AGN, that the colours of the AGN host galaxy are consistent with AGN, and, by comparing their luminosities with those from our comparison clusters, confirm that the AGN hosts are consistent with BCGs.

  1. SUPERNOVAE AND AGN DRIVEN GALACTIC OUTFLOWS

    SciTech Connect

    Sharma, Mahavir; Nath, Biman B. E-mail: biman@rri.res.in

    2013-01-20

    We present analytical solutions for winds from galaxies with a Navarro-Frank-White (NFW) dark matter halo. We consider winds driven by energy and mass injection from multiple supernovae (SNe), as well as momentum injection due to radiation from a central black hole. We find that the wind dynamics depends on three velocity scales: (1) v{sub *}{approx}( E-dot / 2 M-dot ){sup 1/2} describes the effect of starburst activity, with E-dot and M-dot as energy and mass injection rate in a central region of radius R; (2) v {sub .} {approx} (GM {sub .}/2R){sup 1/2} for the effect of a central black hole of mass M {sub .} on gas at distance R; and (3) v{sub s}=(GM{sub h} / 2Cr{sub s}){sup 1/2}, which is closely related to the circular speed (v{sub c} ) for an NFW halo, where r{sub s} is the halo scale radius and C is a function of the halo concentration parameter. Our generalized formalism, in which we treat both energy and momentum injection from starbursts and radiation from the central active galactic nucleus (AGN), allows us to estimate the wind terminal speed to be (4v {sup 2} {sub *} + 6({Gamma} - 1)v {sub .} {sup 2} - 4v {sup 2} {sub s}){sup 1/2}, where {Gamma} is the ratio of force due to radiation pressure to gravity of the central black hole. Our dynamical model also predicts the following: (1) winds from quiescent star-forming galaxies cannot escape from 10{sup 11.5} M {sub Sun} {<=} M{sub h} {<=} 10{sup 12.5} M {sub Sun} galaxies; (2) circumgalactic gas at large distances from galaxies should be present for galaxies in this mass range; (3) for an escaping wind, the wind speed in low- to intermediate-mass galaxies is {approx}400-1000 km s{sup -1}, consistent with observed X-ray temperatures; and (4) winds from massive galaxies with AGNs at Eddington limit have speeds {approx}> 1000 km s{sup -1}. We also find that the ratio [2v {sup 2} {sub *} - (1 - {Gamma})v {sub .} {sup 2}]/v {sup 2} {sub c} dictates the amount of gas lost through winds. Used in conjunction with

  2. Membranoproliferative glomerulonephritis

    MedlinePlus

    ... glomeruli. The glomeruli of the kidney help filter wastes and fluids from the blood to form urine. ... the glomerular basement membrane. This membrane helps filter wastes and extra fluids from the blood. Damage to ...

  3. Mini Survey of SDSS [OIII] AGN with Swift: Testing the Hypothesis that L(sub [OIII]) Traces AGN Luminosity

    NASA Technical Reports Server (NTRS)

    2007-01-01

    The number of AGN and their luminosity distribution are crucial parameters for our understanding of the AGN phenomenon. Recent work strongly suggests every massive galaxy has a central black hole. However most of these objects either are not radiating or have been very difficult to detect We are now in the era of large surveys, and the luminosity function (LF] of AGN has been estimated in various ways. In the X-ray band. Chandra and XMM surveys have revealed that the LF of hard X-ray selected AGN shows a strong luminosity-dependent evolution with a dramatic break towards low L(sub x) (at all z). This is seen for all types of AGN, but is stronger for the broad-line objects. In sharp contrast, the local LF of optically-selected samples shows no such break and no differences between narrow and broad-line objects. If as been suggested, hard X ray and optical emission line can both can be fair indicators of AGN activity, it is important to first understand how reliable these characteristics are if we hope to understand the apparent discrepancy in the LFs.

  4. On the Importance of Very Light Internally Subsonic AGN Jets in Radio-mode AGN Feedback

    NASA Astrophysics Data System (ADS)

    Guo, Fulai

    2016-07-01

    Radio-mode active galactic nucleus (AGN) feedback plays a key role in the evolution of galaxy groups and clusters. Its physical origin lies in the kiloparsec-scale interaction of AGN jets with the intracluster medium. Large-scale jet simulations often initiate light internally supersonic jets with density contrast 0.01 < η < 1. Here we argue for the first time for the importance of very light (η < 0.01) internally subsonic jets. We investigated the shapes of young X-ray cavities produced in a suite of hydrodynamic simulations, and found that bottom-wide cavities are always produced by internally subsonic jets, while internally supersonic jets inflate cylindrical, center-wide, or top-wide cavities. We found examples of real cavities with shapes analogous to those inflated in our simulations by internally subsonic and internally supersonic jets, suggesting a dichotomy of AGN jets according to their internal Mach numbers. We further studied the long-term cavity evolution, and found that old cavities resulted from light jets spread along the jet direction, while those produced by very light jets are significantly elongated along the perpendicular direction. The northwestern ghost cavity in Perseus is pancake shaped, providing tentative evidence for the existence of very light jets. Our simulations show that very light internally subsonic jets decelerate faster and rise much slower in the intracluster medium than light internally supersonic jets, possibly depositing a larger fraction of jet energy to cluster cores and alleviating the problem of low coupling efficiencies found previously. The internal Mach number points to the jet’s energy content, and internally subsonic jets are energetically dominated by non-kinetic energy, such as thermal energy, cosmic rays, or magnetic fields.

  5. The dissociation of arterial hypertension and lupus glomerulonephritis in systemic lupus erythematosus.

    PubMed

    Petrin, J; Rozman, B; Dolenc, P; Logar, D; Bozic, B; Vizjak, A; Ferluga, D; Jezersek, P

    1993-06-01

    In spite of several articles questioning the general opinion that arterial hypertension in patients with systemic lupus erythematosus (SLE) is only the consequence of lupus glomerulonephritis (LGN), this still remains the usual pathophysiologic explanation. The purpose of this study was to explore the correlations between hypertension and LGN and to assess the importance of hypertension control for the prognosis of patients. A retrospective analysis of 173 patients with SLE over a period of 14 years was performed. For most of the patients, data were available from regular follow-up visits over an average of 6 years. Our results show a dissociation of hypertension and LGN and an association of hypertension and renal dysfunction. Severe hypertensive renal vascular lesions correlated well with a decrease of renal function. Successful treatment of hypertension is therefore essential in order to prevent deterioration of renal function in patients with LGN.

  6. Anti-glomerular basement membrane crescentic glomerulonephritis: A report from India and review of literature

    PubMed Central

    Gupta, A.; Agrawal, V.; Kaul, A.; Verma, R.; Pandey, R.

    2016-01-01

    Anti-glomerular basement membrane (anti-GBM) disease is an autoimmune disease that most commonly presents as rapidly progressive glomerulonephritis with or without pulmonary involvement. It is characterized by the presence of antibodies directed to antigenic targets within glomerular and alveolar basement membranes. This study was performed to evaluate the clinicopathological features and outcome in anti-GBM crescentic glomerulonephritis (CrGN) at a tertiary care center in North India over a period of 9 years (January 2004 to December 2012). A diagnosis of anti-GBM CrGN was made in the presence of >50% crescents, linear deposits of IgG along GBM, and raised serum anti-GBM antibody titer. Of 215 cases of CrGN diagnosed during this period, 11 had anti-GBM CrGN. Anti-GBM CrGN was found at all ages but was most common in the third to fifth decade with no gender predilection (mean age 48 +/- 15 years, 13–67 years). Patients presented with a mean serum creatinine of 10.2 +/- 5.3 mg/dl and sub-nephrotic proteinuria. Pulmonary involvement was present in two patients. Myeloperoxidase-antineutrophil cytoplasmic antibody was positive in two (2/11) elderly patients. Follow-up was available in four patients for a range of 30-270 (mean 99.5 ± 114.5) days, two remained dialysis dependent while two died due to uremia and sepsis. Our findings show that anti-GBM disease is a rare cause of CrGN in India, accounting for only 5% of patients. It usually presents as a renal-limited disease and is associated with a poor renal outcome. PMID:27795626

  7. Plasma exchange for renal vasculitis and idiopathic rapidly progressive glomerulonephritis: a meta-analysis

    PubMed Central

    Walsh, Michael; Catapano, Fausta; Szpirt, Wladimir; Thorlund, Kristian; Bruchfeld, Annette; Guillevin, Loic; Haubitz, Marion; Merkel, Peter A.; Peh, Chen Au; Pusey, Charles; Jayne, David

    2011-01-01

    Background Plasma exchange may be effective adjunctive treatment for renal vasculitis. We performed a systematic review and meta-analysis of randomized control trials of plasma exchange for renal vasculitis. Study Design Systematic review and meta-analysis of manuscripts identified from electronic databases, bibliographies, and studies identified by experts. Data was abstracted in parallel by two reviewers. Setting & Population Adults with idiopathic renal vasculitis or rapidly progressive glomerulonephritis Selection Criteria for Studies Randomized controlled trials that compared standard care with standard care plus adjuvant plasma exchange in adult patients with either renal vasculitis or idiopathic rapidly progressive glomerulonephritis. Intervention Adjuvant plasma exchange Outcome Composite of end-stage renal disease or death. Results We identified 9 trials including 387 patients. In a fixed-effects model the pooled relative risk of end-stage renal disease or death was 0.80 for patients treated with adjunctive plasma exchange compared to standard care alone (95% confidence interval 0.65 to 0.99; p=0.04). No significant heterogeneity was detected (p=0.5; I2=0%). The effect of plasma exchange did not differ significantly across the range of baseline serum creatinine values (p=0.7) or number of plasma exchange treatments (p=0.8). The relative risk for end-stage renal disease was 0.64 (95% confidence interval 0.47 to 0.88; p=0.006) while the relative risk for death alone was 1.01 (95% confidence interval 0.71 to 1.4; p=0.9). Limitations Although the primary result was statistically significant, there is insufficient statistical information to reliable determine if plasma exchange reduces the composite of end-stage renal disease or death. Conclusions Plasma exchange may reduce the composite endpoint of end-stage renal disease or death in renal vasculitis. Further trials are required given the limited data available. PMID:21194817

  8. Platelets are not critical effector cells for the time course of murine passive crescentic glomerulonephritis.

    PubMed

    Hohenstein, Bernd; Daniel, Christoph; Johnson, Richard J; Amann, Kerstin U; Hugo, Christian P M

    2013-01-01

    Although platelets are well-known effector cells of inflammatory renal disease, clinical studies were not able to establish platelet inhibition as an effective therapy. Our previous studies using Vasodilator stimulated Phosphoprotein- and P2Y1-deficient mice suggested some early, but no long-term effects of platelets in passive crescentic glomerulonephritis. To define the role of platelets for this disease model, passive crescentic glomerulonephritis was induced in 72 C57Bl/6 mice by intraperitoneal injection of sheep anti-rabbit glomerular basement membrane antibody on 2 consecutive days. Platelets were depleted using anti-glycoprotein Ibα antibodies (p0p3/p0p4) every 4th day. Mice treated with equal amounts of sterile Phosphate buffered solution or rat-IgG served as controls. Blood, urine, and tissues were harvested on days 3 and 28. Renal tissue sections were evaluated after immunostaining using (semi)quantitative and computer-assisted image analysis. Compared to controls, efficient depletion was achieved as indicated by a markedly prolonged bleeding time and a more than 90% reduction in platelet counts (800/nl vs. 42/nl; P < 0.001). Functional (creatinine-clearance and proteinuria) parameters demonstrated no significant differences between the groups. Neither parameters of renal injury (glomerulosclerosis and fibrosis) nor glomerular/tubulointerstitial matrix expansion (by collagen IV staining), glomerular capillary rarefaction (lectin staining), and the glomerular/tubulointerstitial proliferative response (proliferating cell nuclear antigen) demonstrated any differences between platelet-depleted mice and PBS- or rat-IgG-treated nephritic mice at any time point. Despite effective platelet inhibition/depletion, neither the short- nor long-term course of passive crescentic nephrotoxic nephritis was affected. These data indicate that platelets play a minor role during the time course of this disease model in the mouse.

  9. Reclassification of membranoproliferative glomerulonephritis: Identification of a new GN: C3GN

    PubMed Central

    Salvadori, Maurizio; Rosso, Giuseppina

    2016-01-01

    This review revises the reclassification of the membranoproliferative glomerulonephritis (MPGN) after the consensus conference that by 2015 reclassified all the glomerulonephritis basing on etiology and pathogenesis, instead of the histomorphological aspects. After reclassification, two types of MPGN are to date recognized: The immunocomplexes mediated MPGN and the complement mediated MPGN. The latter type is more extensively described in the review either because several of these entities are completely new or because the improved knowledge of the complement cascade allowed for new diagnostic and therapeutic approaches. Overall the complement mediated MPGN are related to acquired or genetic cause. The presence of circulating auto antibodies is the principal acquired cause. Genetic wide association studies and family studies allowed to recognize genetic mutations of different types as causes of the complement dysregulation. The complement cascade is a complex phenomenon and activating factors and regulating factors should be distinguished. Genetic mutations causing abnormalities either in activating or in regulating factors have been described. The diagnosis of the complement mediated MPGN requires a complete study of all these different complement factors. As a consequence, new therapeutic approaches are becoming available. Indeed, in addition to a nonspecific treatment and to the immunosuppression that has the aim to block the auto antibodies production, the specific inhibition of complement activation is relatively new and may act either blocking the C5 convertase or the C3 convertase. The drugs acting on C3 convertase are still in different phases of clinical development and might represent drugs for the future. Overall the authors consider that one of the principal problems in finding new types of drugs are both the rarity of the disease and the consequent poor interest in the marketing and the lack of large international cooperative studies. PMID:27458560

  10. Spectropolarimetry of AGN, and `Women &\\ Science'

    NASA Astrophysics Data System (ADS)

    Kay, L.

    1999-12-01

    I have been using optical spectropolarimetry to investigate the nature of AGN. For the CAREER project, I have worked with A. M. Magalhães of the IAG in Brazil to use a visiting polarimetry module with the RC Spectrograph at CTIO, as well as conduct observations at Lick. Projects include observations of broad--line radio galaxies with double--peaked emission line profiles suggestive of accretion disks, and observations of a sample of X-ray selected narrow--line Seyfert 1 galaxies. Another project involves optical and X-ray observations of a complete sample of nearby Seyfert 2 galaxies in order to investigate the frequency of obscured broad--line regions and to determine their contribution to the X-ray background. In addition to involving undergraduate students in research, my educational efforts have focused on getting science into our Women's Studies program. I teach a course on the history and sociology of women in science, co-teach a course on feminist science studies, helped to create a course on women's health, organized a faculty seminar on gender and science issues, and lead a project at Barnard on gender and scientific literacy. I gratefully acknowledge support from NSF CAREER grant AST-9501835, as well as support from NSF International Research Fellowship INT-9423970, and from NSF grant EHR-9555808 to the AAC&U for the Gender and Scientific Literacy project.

  11. Optically faint radio sources: reborn AGN?

    NASA Astrophysics Data System (ADS)

    Filho, M. E.; Brinchmann, J.; Lobo, C.; Antón, S.

    2011-12-01

    We present our discovery of several relatively strong radio sources in the field-of-view of SDSS galaxy clusters that have no optical counterparts down to the magnitude limits of the SDSS. The optically faint radio sources appear as double-lobed or core-jet objects in the FIRST radio images and have projected angular sizes ranging from 0.5 to 1.0 arcmin. We followed-up these sources with near-infrared imaging using the wide-field imager HAWK-I on the VLT. We detected Ks-band emitting regions, about 1.5 arcsec in size and coincident with the centers of the radio structures, in all sources, with magnitudes in the range 17-20 mag. We used spectral modelling to characterize the sample sources. In general, the radio properties are similar to those observed in 3CRR sources but the optical-radio slopes are consistent with those of moderate to high redshift (z < 4) gigahertz-peaked spectrum sources. Our results suggest that these unusual objects are galaxies whose black hole has been recently re-ignited but that retain large-scale radio structures, which are signatures of previous AGN activity.

  12. Reconfinement shocks in relativistic AGN jets

    SciTech Connect

    Nalewajko, Krzysztof; Sikora, Marek

    2008-12-24

    Stationary knots observed in many AGN jets can be explained in terms of a reconfinement shock that forms when relativistic flow of the jet matter collides with the external medium. The position of these knots can be used, together with information on external pressure profile, to constrain dynamical parameters of the jet. We present a semi-analytical model for the dynamical structure of reconfinement shocks, taking into account exact conservation laws both across the shock surface and in the zone of the shocked jet matter. We show that, due to the transverse pressure gradient in the shock zone, the position of the reconfinement is larger than predicted by simple models. A portion of kinetic energy is converted at the shock surface to internal energy, with efficiency increasing strongly with both bulk Lorentz factor of the jet matter and the jet half-opening angle. Our model may be useful as a framework for modeling non-thermal radiation produced within the stationary features.

  13. Accretion disk modeling of AGN continuum using non-LTE stellar atmospheres. [active galactic nuclei (AGN)

    NASA Technical Reports Server (NTRS)

    Sun, Wei-Hsin; Malkan, Matthew A.

    1988-01-01

    Active galactic nuclei (AGN) accretion disk spectra were calculated using non-LTE stellar atmosphere models for Kerr and Schwarzschild geometries. It is found that the Lyman limit absorption edge, probably the most conclusive observational evidence for the accretion disk, would be drastically distorted and displaced by the relativistic effects from the large gravitational field of the central black hole and strong Doppler motion of emitting material on the disk surface. These effects are especially pronounced in the Kerr geometry. The strength of the Lyman limit absorption is very sensitive to the surface gravity in the stellar atmosphere models used. For models at the same temperature but different surface gravities, the strength of the Lyman edge exhibits an almost exponential decrease as the surface gravity approach the Eddington limit, which should approximate the thin disk atmosphere. The relativistic effects as well as the vanishing of the Lyman edge at the Eddington gravity may be the reasons that not many Lyman edges in the rest frames of AGNs and quasars are found.

  14. AGN host galaxy mass function in COSMOS. Is AGN feedback responsible for the mass-quenching of galaxies?

    NASA Astrophysics Data System (ADS)

    Bongiorno, A.; Schulze, A.; Merloni, A.; Zamorani, G.; Ilbert, O.; La Franca, F.; Peng, Y.; Piconcelli, E.; Mainieri, V.; Silverman, J. D.; Brusa, M.; Fiore, F.; Salvato, M.; Scoville, N.

    2016-04-01

    We investigate the role of supermassive black holes in the global context of galaxy evolution by measuring the host galaxy stellar mass function (HGMF) and the specific accretion rate, that is, λSAR, the distribution function (SARDF), up to z ~ 2.5 with ~1000 X-ray selected AGN from XMM-COSMOS. Using a maximum likelihood approach, we jointly fit the stellar mass function and specific accretion rate distribution function, with the X-ray luminosity function as an additional constraint. Our best-fit model characterizes the SARDF as a double power-law with mass-dependent but redshift-independent break, whose low λSAR slope flattens with increasing redshift while the normalization increases. This implies that for a given stellar mass, higher λSAR objects have a peak in their space density at earlier epoch than the lower λSAR objects, following and mimicking the well-known AGN cosmic downsizing as observed in the AGN luminosity function. The mass function of active galaxies is described by a Schechter function with an almost constant M∗⋆ and a low-mass slope α that flattens with redshift. Compared to the stellar mass function, we find that the HGMF has a similar shape and that up to log (M⋆/M⊙) ~ 11.5, the ratio of AGN host galaxies to star-forming galaxies is basically constant (~10%). Finally, the comparison of the AGN HGMF for different luminosity and specific accretion rate subclasses with a previously published phenomenological model prediction for the "transient" population, which are galaxies in the process of being mass-quenched, reveals that low-luminosity AGN do not appear to be able to contribute significantly to the quenching and that at least at high masses, that is, M⋆ > 1010.7 M⊙, feedback from luminous AGN (log Lbol ≳ 46 [erg/s]) may be responsible for the quenching of star formation in the host galaxy.

  15. Average Heating Rate of Hot Atmospheres in Distant Galaxy Clusters by Radio AGN: Evidence for Continuous AGN Heating

    NASA Astrophysics Data System (ADS)

    Ma, Cheng-Jiun; McNamara, B.; Nulsen, P.; Schaffer, R.

    2011-09-01

    X-ray observations of nearby clusters and galaxies have shown that energetic feedback from AGN is heating hot atmospheres and is probably the principal agent that is offsetting cooling flows. Here we examine AGN heating in distant X-ray clusters by cross correlating clusters selected from the 400 Square Degree X-ray Cluster survey with radio sources in the NRAO VLA Sky Survey. The jet power for each radio source was determined using scaling relations between radio power and cavity power determined for nearby clusters, groups, and galaxies with atmospheres containing X-ray cavities. Roughly 30% of the clusters show radio emission above a flux threshold of 3 mJy within the central 250 kpc that is presumably associated with the brightest cluster galaxy. We find no significant correlation between radio power, hence jet power, and the X-ray luminosities of clusters in redshift range 0.1 -- 0.6. The detection frequency of radio AGN is inconsistent with the presence of strong cooling flows in 400SD, but cannot rule out the presence of weak cooling flows. The average jet power of central radio AGN is approximately 2 10^{44} erg/s. The jet power corresponds to an average heating of approximately 0.2 keV/particle for gas within R_500. Assuming the current AGN heating rate remained constant out to redshifts of about 2, these figures would rise by a factor of two. Our results show that the integrated energy injected from radio AGN outbursts in clusters is statistically significant compared to the excess entropy in hot atmospheres that is required for the breaking of self-similarity in cluster scaling relations. It is not clear that central AGN in 400SD clusters are maintained by a self-regulated feedback loop at the base of a cooling flow. However, they may play a significant role in preventing the development of strong cooling flows at early epochs.

  16. CHARACTERIZATION OF A SAMPLE OF INTERMEDIATE-TYPE AGNs. I. SPECTROSCOPIC PROPERTIES AND SERENDIPITOUS DISCOVERY OF NEW DUAL AGNs

    SciTech Connect

    Benitez, Erika; Cruz-Gonzalez, Irene; Martinez, Benoni; Jimenez-Bailon, Elena; Mendez-Abreu, Jairo; Lopez-Martin, Luis; Fuentes-Carrera, Isaura; Leon-Tavares, Jonathan; Chavushyan, Vahram H.

    2013-01-20

    A sample of 10 nearby intermediate-type active galactic nuclei (AGNs) drawn from the Sloan Digital Sky Survey is presented. The aim of this work is to provide estimations of the black hole (BH) mass for the sample galaxies from the dynamics of the broad-line region. For this purpose, a detailed spectroscopic analysis of the objects was done. Using Baldwin-Phillips-Terlevich diagnostic diagrams, we have carefully classified the objects as true intermediate-type AGNs and found that 80%{sup +7.2%} {sub -17.3%} are composite AGNs. The BH mass estimated for the sample is within 6.54 {+-} 0.16 < log M {sub BH} < 7.81 {+-} 0.14. Profile analysis shows that five objects (J120655.63+501737.1, J121607.08+504930.0, J141238.14+391836.5, J143031.18+524225.8, and J162952.88+242638.3) have narrow double-peaked emission lines in both the red (H{alpha}, [N II] {lambda}{lambda}6548,6583 and [S II] {lambda}{lambda}6716, 6731) and the blue (H{beta} and [O III] {lambda}{lambda}4959, 5007) regions of the spectra, with velocity differences ({Delta}V) between the double peaks within 114 km s{sup -1} < {Delta}V < 256 km s{sup -1}. Two of them, J121607.08+504930.0 and J141238.14+391836.5, are candidates for dual AGNs since their double-peaked emission lines are dominated by AGN activity. In searches of dual AGNs, type 1, type II, and intermediate-type AGNs should be carefully separated, due to the high serendipitous number of narrow double-peaked sources (50% {+-} 14.4%) found in our sample.

  17. Interferometric IR observations: a diversity of dusty AGN tori

    NASA Astrophysics Data System (ADS)

    Burtscher, Leonard

    Interferometric observations in the infrared have resolved dusty structures on parsec and sub-parsec scales in more than two dozen AGNs by now -- a giant leap when considering that the first infrared interferometric observation of an extragalactic object is only about 10 years old. Since then, studies have confirmed the existence of dust in AGNs at its sublimation radius and have clearly dismissed models of very extended tori. Individual, well studied sources have been instrumental to reveal the complexity of these parsec-scale structures and statistical studies have shown a perplexing diversity in the population as a whole. Surprisingly, the diversity does not seem to follow the expected bimodality between optical type 1 and type 2 AGNs -- which are thought to be just face-on and edge-on tori. This central premise of viewing-angle dependent unified models is challenged if not dismissed by interferometric observations. The next step in understanding the AGN phenomenon -- beyond unification aspects -- is now to combine multi-scale observations with multi-scale simulations to constrain the physical processes driving the feeding and feedback of AGNs.

  18. Mini-Survey of SDSS OIII AGN with Swift

    NASA Technical Reports Server (NTRS)

    Angelina, Lorella; George, Ian

    2007-01-01

    There is a common wisdom that every massive galaxy has a massive block hole. However, most of these objects either are not radiating or until recently have been very difficult to detect. The Sloan Digital Sky Survey (SDSS) data, based on the [OIII] line indicate that perhaps up to 20% of all galaxies may be classified as AGN a surprising result that must be checked with independent data. X-ray surveys have revealed that hard X-ray selected AGN show a strong luminosity dependent evolution and their luminosity function (LF) shows a dramatic break towards low Lx (at all z). This is seen for all types of AGN, but is stronger for the broad-line objects. In sharp contrast, the local LF of (optically-selected samples) shows no such break and no differences between narrow and broad-line objects. Assuming both hard X-ray and [OIII] emission are fair indicators of AGN activity, it is important to understand this discrepancy. We present here the results of a mini-survey done with Swift on a selected sample of SDSS selected AGN. The objects have been sampled at different L([OIII]) to check the relation with the Lx observed with Swift.

  19. Inverse Compton X-ray signature of AGN feedback

    NASA Astrophysics Data System (ADS)

    Bourne, Martin A.; Nayakshin, Sergei

    2013-12-01

    Bright AGN frequently show ultrafast outflows (UFOs) with outflow velocities vout ˜ 0.1c. These outflows may be the source of AGN feedback on their host galaxies sought by galaxy formation modellers. The exact effect of the outflows on the ambient galaxy gas strongly depends on whether the shocked UFOs cool rapidly or not. This in turn depends on whether the shocked electrons share the same temperature as ions (one-temperature regime, 1T) or decouple (2T), as has been recently suggested. Here we calculate the inverse Compton spectrum emitted by such shocks, finding a broad feature potentially detectable either in mid-to-high energy X-rays (1T case) or only in the soft X-rays (2T). We argue that current observations of AGN do not seem to show evidence for the 1T component. The limits on the 2T emission are far weaker, and in fact it is possible that the observed soft X-ray excess of AGN is partially or fully due to the 2T shock emission. This suggests that UFOs are in the energy-driven regime outside the central few pc, and must pump considerable amounts of not only momentum but also energy into the ambient gas. We encourage X-ray observers to look for the inverse Compton components calculated here in order to constrain AGN feedback models further.

  20. Analyses of the Variability Asymmetry of Kepler AGNs

    NASA Astrophysics Data System (ADS)

    Chen, Xiao-Yang; Wang, Jun-Xian

    2015-05-01

    The high-quality light curves from the Kepler space telescope make it possible to analyze the optical variability of active galactic nuclei (AGNs) with unprecedented time resolution. Studying the asymmetry in variations could provide independent constraints on physical models for AGN variability. In this paper, we use Kepler observations of 19 sources to perform analyses of the variability asymmetry of AGNs. We apply smoothing correction to light curves to deduct their bias toward high-frequency variability asymmetry caused by long-term variations that have been poorly sampled due to the limited length of light curves. A parameter β based on structure functions is introduced to quantitively describe the asymmetry and its uncertainty is measured using extensive Monte Carlo simulations. Individual sources show no evidence of asymmetry at timescales of 1˜ 20 days and there is no general trend toward positive or negative asymmetry over the whole sample. Stacking the data from all 19 AGNs, we derive an averaged \\bar{β } of 0.00 ± 0.03 and -0.02 ± 0.04 over timescales of 1 ˜ 5 days and 5 ˜ 20 days, respectively, which are statistically consistent with zero. Quasars and Seyfert galaxies show similar asymmetry parameters. Our results indicate that short-term optical variations in AGNs are highly symmetric.

  1. Mid-infrared Flux Variability in an Awakening AGN

    NASA Astrophysics Data System (ADS)

    Yeh, Sherry

    We propose FORCAST spectroscopic observations between 8 um to 40 um near the nucleus of NGC 660. NGC 660 underwent an AGN outburst 6 years ago, which is an ideal case for studying AGN astrophysics in a rather quiecent system. However, this rare event has not yet been monitored. Our immidiate goal is to verify the MIR spectroscipic variabilitiy in NGC 660, and to study the AGN effects on dust destruction and ISM. We will compare the FORCAST spectra with the Spitzer IRS spectra (taken before the AGN outburst), including dust continuum, PAH emission, and high- and low-ionization emission lines. FORCAST's slit width is a close match to the IRS slit width, allowing a direct comparison of the spectra between FORCAST and IRS. Our single-slit Subaru COMICS spectrum taken after the outburst shows significantly weakened PAH emission and dust continuum, suggesting dust destruction. However, it is difficult to draw robust intepretations due to systematic uncertainties in the Subaru data. If dust destruction is confirmed in the post-outburst FORCAST observaitons, we will evaluate the energy budget using the MIR line ratio diagnostics, with archival X-ray and radio data. We will then propose cadence observations of MGC 660's nucleus to monitor the MIR flux variability, and employ the reverberation mapping technique to study NGC 660's AGN.

  2. Circular Polarization in AGNs: Polarity and Spectra

    NASA Astrophysics Data System (ADS)

    Aller, M. F.; Aller, H. D.; Plotkin, R. M.

    2005-12-01

    Circular polarization (Stokes V) observations potentially provide information on the nature and origin of the underlying magnetic fields in AGNs. We have been systematically monitoring a group of sources with detectable circular polarization (V>0.1 percent, a level set by the instrumental polarization of our system) in all 4 Stokes parameters at 8.0 and 4.8 GHz since 2000, and also at 14.5 GHz since November 2003, with the University of Michigan prime focus paraboloid antenna. These data are compared with historical observations obtained with the same instrument at 8.0 and 4.8 GHz extending back to 1978. Specific goals are to study the temporal spectral behavior of Stokes V and its relation to variability in total flux and linear polarization, and to investigate the question of polarity stability on decade-long time scales using data obtained with the same instrumentation and at the same frequencies. The data are consistent with linear-to-circular mode conversion in partially opaque regions of the source. We find examples of polarity changes with time at one or more frequencies associated with outbursts in total flux and linear polarization, and polarity differences within the 3 frequencies at a single epoch in one case, 3C 279. Such behavior argues against the notion that the sign of Stokes V is a simple tracer of the net flow of magnetic energy from the central engine to the jet or an indicator of the direction of rotation of the spinning central black hole/accretion disk via the winding up of the initial seed magnetic field. This work was supported in part by NSF grant AST-0307629 and by funds from the University of Michigan.

  3. Agnes Pockels: Life, Letters and Papers

    NASA Astrophysics Data System (ADS)

    Helm, Christiane A.

    2004-03-01

    Agnes Pockels (1862 - 1935) was a German woman, whose studies pioneered surface science. She was born in malaria infected North Italy while her father served in the Austrian army. Because he suffered adverse health effects, the family moved in1871 to Braunschweig (North Germany). There, Pockels went to high school. She was interested in science, but formal training was not available for girls. She took on the role of household manager and nurse as her parents' health deteriorated further. Her diary illustrates the difficulties she faced in trying to maintain her own health, the health of her parents and her scientific research at the same time. When Pockels was 18 or 19, she designed a ring tensiometer. Additionally, she found a new method to introduce water-insoluble compounds to the water surface by dissolving them in an organic solvent, and applying drops of the solution. Her surface film balance technique from 1882 is the basis for the method later developed by Langmuir. Since her experimental work was highly original and in a new field, she failed to get it recognized in her own country. When she was 28, she wrote to Lord Rayleigh, since she had read about his recent experiments in surface physics. Rayleigh was so impressed with her experimental methods and results that he had her letter translated from German and published it in Nature (1891). She continued her research on surface films, interactions of solutions and contact angles (more papers, 3 in Nature). Still, she did all experiments at home. With the death of her brother in 1913 and the onset of the war, she retired into private life. Thus she was surprised when she was awarded in her late 60ies with a honorary doctorate by the TU Braunschweig (1932) and the annual prize of the German Colloid Society (1931).

  4. AGN variability in the radio band

    NASA Astrophysics Data System (ADS)

    Max-Moerbeck, Walter

    2016-08-01

    Variability is an important and defining characteristic of AGN, that along with their broadband spectral energy distribution make their study interesting and challenging. A complete understanding of the physics of these objects requires monitoring observations over the whole electromagnetic spectrum, and includes studying their properties at a given band and also the relationship between multiple wavelengths. Here we present the main results obtained so far with the ongoing OVRO 40m blazar monitoring program at 15 GHz with twice a week cadence. This program started in mid-2007 and is currently monitoring about 1800 blazars, including most of the bright blazars north of declination -20 degrees. These results include: characterization of the variability in the radio band; its relationship with optical and gamma-ray properties; and its relationship to gamma-ray emission as observed with Fermi-LAT, which can provide constrains on the location of the gamma-ray emission region. We will also discuss our ongoing work on the characterization of radio variability using the power spectral density. For this, we are using 8 years of OVRO 40m data for ~1200 sources, and also F-GAMMA monitoring data taken with the Effelsberg 100m telescope for 60 sources with about monthly cadence monitoring data at 8 frequencies between 2.6 and 43.0 GHz. These studies will provide an improved understanding of blazar variability, a better basis to evaluate the statistics of correlated variability between different emission bands, and a long and consistent record of radio observations to be used in gamma-ray and multi-wavelength investigations.

  5. BAT AGN Spectroscopic Survey - III. An observed link between AGN Eddington ratio and narrow-emission-line ratios

    NASA Astrophysics Data System (ADS)

    Oh, Kyuseok; Schawinski, Kevin; Koss, Michael; Trakhtenbrot, Benny; Lamperti, Isabella; Ricci, Claudio; Mushotzky, Richard; Veilleux, Sylvain; Berney, Simon; Crenshaw, D. Michael; Gehrels, Neil; Harrison, Fiona; Masetti, Nicola; Soto, Kurt T.; Stern, Daniel; Treister, Ezequiel; Ueda, Yoshihiro

    2017-01-01

    We investigate the observed relationship between black hole mass (MBH), bolometric luminosity (Lbol) and Eddington ratio (λEdd) with optical emission-line ratios ([N II] λ6583/Hα, [S II] λλ6716, 6731/Hα, [O I] λ6300/Hα, [O III] λ5007/Hβ, [Ne III] λ3869/Hβ and He II λ4686/Hβ) of hard X-ray-selected active galactic nuclei (AGN) from the BAT AGN Spectroscopic Survey. We show that the [N II] λ6583/Hα ratio exhibits a significant correlation with λEdd (RPear = -0.44, p-value = 3 × 10-13, σ = 0.28 dex), and the correlation is not solely driven by MBH or Lbol. The observed correlation between [N II] λ6583/Hα ratio and MBH is stronger than the correlation with Lbol, but both are weaker than the λEdd correlation. This implies that the large-scale narrow lines of AGN host galaxies carry information about the accretion state of the AGN central engine. We propose that [N II] λ6583/Hα is a useful indicator of Eddington ratio with 0.6 dex of rms scatter, and that it can be used to measure λEdd and thus MBH from the measured Lbol, even for high-redshift obscured AGN. We briefly discuss possible physical mechanisms behind this correlation, such as the mass-metallicity relation, X-ray heating, and radiatively driven outflows.

  6. Time-Dependent Photoionization of Gas Outflows in AGN

    NASA Astrophysics Data System (ADS)

    Elhoussieny, Ehab E.; Bautista, M.; Garcia, J.; Kallman, T. R.

    2013-01-01

    Gas outflows are fundamental components of Active Galactic Nuclei (AGN) activity. Time-variability of ionizing radiation, which is characteristic of AGN in various different time scales, may produce non-equilibrium photoionization conditions over a significant fraction of the flow and yields supersonically moving cooling/heating fronts. These fast fronts create pressure imbalances that can only be resolved by fragmentation of the flow and acceleration of such fragments. This mechanism can explain the kinematic structure of low ionization BAL systems (FeLoBAL). This mechanism may also have significant effects on other types of outflows given the wide range of variability time scales in AGN. We will study these effects in detail by constructing time-dependent photoionization models of the outflows and incorporating these models into radiative-hydrodynamic simulations.

  7. Disentangling AGN-Host Galaxy Interactions with Chandra

    NASA Astrophysics Data System (ADS)

    Wang, Junfeng

    2014-11-01

    The circum-nuclear region in active galaxies is often complex with presence of high excitation gas, collimated radio outflow, and star forming regions, besides the active central supermassive black hole. In Chandra studies of a number of archetypal Seyfert galaxies to investigate AGN-host galaxy interaction, we were able to evaluate the mass outflow rate and shock heating by radio jet. For galaxies in the throes of a violent merging event such as NGC6240, we were able to resolve 70MK hot gas surrounding the double nuclei and discovered a large scale soft X-ray halo. The unique resolving power of Chandra also enables more discovery of such dual AGN systems and signs of past AGN outburst activities.

  8. Proteomics and glomerulonephritis: A complementary approach in renal pathology for the identification of chronic kidney disease related markers.

    PubMed

    L'Imperio, Vincenzo; Smith, Andrew; Chinello, Clizia; Pagni, Fabio; Magni, Fulvio

    2016-04-01

    Glomerulonephritis (GN) is one of the most common origins of chronic kidney disease and its careful evaluation is crucial for prognostic and therapeutic purposes, with the renal biopsy still playing a central role for the diagnosis. However, due to its invasiveness, it is not devoid of complications and many investigations have focused on identifying biomarkers for chronic kidney diseases using less-invasive and easy-to-collect samples, such as urine and blood. In this context, proteomics has played a crucial role in determining the molecular changes related to disease progression and early pathological glomerular modifications. Here, we report a review of selected literature for each GN, based on selected works published in the last 10 years, showing how these approaches have generated clinically relevant findings in the study of glomerulonephritis. We also describe several proteomic strategies, highlighting their technical advantages and limitations, future perspectives for proteomic applications in the study of GNs, and their possible application in routine practice.

  9. Quenching histories of galaxies and the role of AGN feedback

    NASA Astrophysics Data System (ADS)

    Smethurst, Rebecca Jane; Lintott, Chris; Simmons, Brooke; Galaxy Zoo Team

    2016-01-01

    Two open issues in modern astrophysics are: (i) how do galaxies fully quench their star formation and (ii) how is this affected - or not - by AGN feedback? I present the results of a new Bayesian-MCMC analysis of the star formation histories of over 126,000 galaxies across the colour magnitude diagram showing that diverse quenching mechanisms are instrumental in the formation of the present day red sequence. Using classifications from Galaxy Zoo we show that the rate at which quenching can occur is morphologically dependent in each of the blue cloud, green valley and red sequence. We discuss the nature of these possible quenching mechanisms, considering the influence of secular evolution, galaxy interactions and mergers, both with and without black hole activity. We focus particularly on the relationship between these quenched star formation histories and the presence of an AGN by using this new Bayesian method to show a population of type 2 AGN host galaxies have recently (within 2 Gyr) undergone a rapid (τ < 1 Gyr) drop in their star formation rate. With this result we therefore present the first statistically supported observational evidence that AGN feedback is an important mechanism for the cessation of star formation in this population of galaxies. The diversity of this new method also highlights that such rapid quenching histories cannot account fully for all the quenching across the current AGN host population. We demonstrate that slower (τ > 2 Gyr) quenching rates dominate for high stellar mass (log10[M*/M⊙] > 10.75) hosts of AGN with both early- and late-type morphology. We discuss how these results show that both merger-driven and non-merger processes are contributing to the co-evolution of galaxies and supermassive black holes across the entirety of the colour magnitude diagram.

  10. AGN Survey to characterize the clumpy torus using FORCAST

    NASA Astrophysics Data System (ADS)

    Lopez-Rodriguez, Enrique

    2015-10-01

    A geometrically and optically thick torus of gas and dust obscures the black hole and accretion disk in active galactic nuclei (AGN) in some lines of sight. One of the most important question that still remain uncertain is: How do the properties, such as torus geometry and distribution of clumps, of the torus depend on the AGN luminosity and/or activity class? Infrared (IR) observations are essential to these investigations as the torus intercepts and re-radiates (peaking within 30-40 um) a substantial amount of flux from the central engine. Near-IR (NIR) and mid-IR (MIR) observations from the ground have been key to advance our knowledge in this field. However, the atmosphere is opaque to the 30-40 um range and observations are impossible from ground-based telescopes. FORCAST presents a unique opportunity to explore AGN, providing the best angular resolution observations within the 30-40 um range for the current suite of instruments. From our analysis using Cycle 2 observations, we found that FORCAST provides the largest constraining power of the clumpy torus models in the suggested wavelength range. We therefore request an AGN Survey using FORCAST of snapshot imaging observations of a flux-limited (>500 mJy at 37.1 um) sample of 23 Seyfert galaxies with existing high-angular resolution MIR spectra observed on 8-m class telescopes. Using the FORCAST data requested here in combination with already acquired NIR and MIR data, we will have an unprecedentedly homogeneous AGN sample of IR (1-40 um) SED at the largest spatial-resolution, which yield to a better knowledge of the torus structure in the AGN unified model.

  11. The most obscured AGN in the COSMOS field

    NASA Astrophysics Data System (ADS)

    Lanzuisi, G.; Perna, M.; Delvecchio, I.; Berta, S.; Brusa, M.; Cappelluti, N.; Comastri, A.; Gilli, R.; Gruppioni, C.; Mignoli, M.; Pozzi, F.; Vietri, G.; Vignali, C.; Zamorani, G.

    2015-06-01

    Highly obscured active galactic nuclei (AGN) are common in nearby galaxies, but are difficult to observe beyond the local Universe, where they are expected to significantly contribute to the black hole accretion rate density. Furthermore, Compton-thick (CT) absorbers (NH ≳ 1024 cm-2) suppress even the hard X-ray (2-10 keV) AGN nuclear emission, and therefore the column density distribution above 1024 cm-2 is largely unknown. We present the identification and multi-wavelength properties of a heavily obscured (NH ≳ 1025 cm-2), intrinsically luminous (L2-10 > 1044 erg s-1) AGN at z = 0.353 in the COSMOS field. Several independent indicators, such as the shape of the X-ray spectrum, the decomposition of the spectral energy distribution and X-ray/[NeV] and X-ray/6 μm luminosity ratios, agree on the fact that the nuclear emission must be suppressed by a ≳1025 cm-2 column density. The host galaxy properties show that this highly obscured AGN is hosted in a massive star-forming galaxy, showing a barred morphology, which is known to correlate with the presence of CT absorbers. Finally, asymmetric and blueshifted components in several optical high-ionization emission lines indicate the presence of a galactic outflow, possibly driven by the intense AGN activity (LBol/LEdd = 0.3-0.5). Such highly obscured, highly accreting AGN are intrinsically very rare at low redshift, whereas they are expected to be much more common at the peak of the star formation and BH accretion history, at z ~ 2-3. We demonstrate that a fully multi-wavelength approach can recover a sizable sample of such peculiar sources in large and deep surveys such as COSMOS.

  12. Statin attenuates experimental anti-glomerular basement membrane glomerulonephritis together with the augmentation of alternatively activated macrophages.

    PubMed

    Fujita, Emiko; Shimizu, Akira; Masuda, Yukinari; Kuwahara, Naomi; Arai, Takashi; Nagasaka, Shinya; Aki, Kaoru; Mii, Akiko; Natori, Yasuhiro; Iino, Yasuhiko; Katayama, Yasuo; Fukuda, Yuh

    2010-09-01

    Macrophages are heterogeneous and include classically activated M1 and alternatively activated M2 macrophages, characterized by pro- and anti-inflammatory functions, respectively. Macrophages that express heme oxygenase-1 also exhibit anti-inflammatory effects. We assessed the anti-inflammatory effects of statin in experimental anti-glomerular basement membrane glomerulonephritis and in vitro, focusing on the macrophage heterogeneity. Rats were induced anti-glomerular basement membrane glomerulonephritis and treated with atorvastatin (20 mg/kg/day) or vehicle (control). Control rats showed infiltration of macrophages in the glomeruli at day 3 and developed crescentic glomerulonephritis by day 7, together with increased mRNA levels of the M1 macrophage-associated cytokines, interferon-gamma, tumor necrosis factor-alpha, and interleukin-12. In contrast, statin reduced the level of proteinuria, reduced infiltration of macrophages in glomeruli with suppression of monocyte chemotactic protein-1 expression, and inhibited the formation of necrotizing and crescentic lesions. The number of glomerular ED3-positive macrophages decreased with down-regulation of M1 macrophage-associated cytokines. Furthermore, statin augmented ED2-positive M2 macrophages with up-regulation of the M2 macrophage-associated chemokines and cytokines, chemokine (C-C motif) Iigand-17 and interleukin-10. Statin also increased the glomerular interleukin-10-expressing heme oxygenase-1-positive macrophages. Statin inhibited macrophage development, and suppressed ED3-positive macrophages, but augmented ED2-positive macrophages in M2-associated cytokine environment in vitro. We conclude that the anti-inflammatory effects of statin in glomerulonephritis are mediated through inhibition of macrophage infiltration as well as augmentation of anti-inflammatory macrophages.

  13. Autoimmunity to the alpha 3 chain of type IV collagen in glomerulonephritis is triggered by ‘autoantigen complementarity’

    PubMed Central

    Reynolds, John; Preston, Gloria A.; Pressler, Barrak M.; Hewins, Peter; Brown, Michael; Roth, Aleeza; Alderman, Elizabeth; Bunch, Donna; Jennette, J. Charles; Cook, H. Terence; Falk, Ronald J.; Pusey, Charles D.

    2015-01-01

    ‘Autoantigen complementarity’ is a theory proposing that the initiator of an autoimmune response is not necessarily the autoantigen or its molecular mimic, but may instead be a peptide that is ‘antisense/complementary’ to the autoantigen. We investigated whether such complementary proteins play a role in the immunopathogenesis of autoimmune glomerulonephritis. Experimental autoimmune glomerulonephritis, a model of anti-glomerular basement membrane (GBM) disease, can be induced in Wistar Kyoto (WKY) rats by immunization with the α3 chain of type IV collagen. In this study, WKY rats were immunized with a complementary α3 peptide (c-α3-Gly) comprised of amino acids that ‘complement’ the well characterized epitope on α3(IV)NC1, pCol(24–38). Within 8 weeks post-immunization, these animals developed cresentic glomerulonephritis, similar to pCol(24–38)-immunized rats, while animals immunized with scrambled peptide were normal. Anti-idiotypic antibodies to epitopes from c-α3-Gly-immunized animals were shown to be specific for α3 protein, binding in a region containing sense pCol(24–38) sequence. Interestingly, anticomplementary α3 antibodies were identified in sera from patients with anti-GBM disease, suggesting a role for ‘autoantigen complementarity’ in immunopathogenesis of the human disease. This work supports the idea that autoimmune glomerulonephritis can be initiated through an immune response against a peptide that is anti-sense or complementary to the autoantigen. The implications of this discovery may be far reaching, and other autoimmune diseases could be due to responses to these once unsuspected ‘complementary’ antigens. PMID:25841937

  14. The NuSTAR view of radio-quiet AGN

    NASA Astrophysics Data System (ADS)

    Marinucci, Andrea

    AUTHORS: A. Marinucci and the NuSTAR Team ABSTRACT: The Nuclear Spectroscopic Telescope Array (NuSTAR), thanks to its improved sensitivity in hard X-rays with respect to coded aperture observatories, is providing new and exciting results on radio-quiet AGN. In this talk I will present results from the NuSTAR AGN Physics program after the first two years of science operations. In particular, measurements of the black hole spin and coronal temperature in nearby sources will be discussed.

  15. The MOSDEF Survey: AGN Multi-wavelength Identification, Selection Biases, and Host Galaxy Properties

    NASA Astrophysics Data System (ADS)

    Azadi, Mojegan; Coil, Alison L.; Aird, James; Reddy, Naveen; Shapley, Alice; Freeman, William R.; Kriek, Mariska; Leung, Gene C. K.; Mobasher, Bahram; Price, Sedona H.; Sanders, Ryan L.; Shivaei, Irene; Siana, Brian

    2017-01-01

    We present results from the MOSFIRE Deep Evolution Field (MOSDEF) survey on the identification, selection biases, and host galaxy properties of 55 X-ray, IR, and optically selected active galactic nuclei (AGNs) at 1.4< z< 3.8. We obtain rest-frame optical spectra of galaxies and AGNs and use the BPT diagram to identify optical AGNs. We examine the uniqueness and overlap of the AGNs identified at different wavelengths. There is a strong bias against identifying AGNs at any wavelength in low-mass galaxies, and an additional bias against identifying IR AGNs in the most massive galaxies. AGN hosts span a wide range of star formation rates (SFRs), similar to inactive galaxies once stellar mass selection effects are accounted for. However, we find (at ∼2–3σ significance) that IR AGNs are in less dusty galaxies with relatively higher SFR and optical AGNs in dusty galaxies with relatively lower SFR. X-ray AGN selection does not display a bias with host galaxy SFR. These results are consistent with those from larger studies at lower redshifts. Within star-forming galaxies, once selection biases are accounted for, we find AGNs in galaxies with similar physical properties as inactive galaxies, with no evidence for AGN activity in particular types of galaxies. This is consistent with AGNs being fueled stochastically in any star-forming host galaxy. We do not detect a significant correlation between SFR and AGN luminosity for individual AGN hosts, which may indicate the timescale difference between the growth of galaxies and their supermassive black holes.

  16. Exanthema and acute anuric renal failure.

    PubMed

    Resch, M; Banas, B; Endemann, D; Mack, M; Riegger, G A J; Gröne, H J; Krämer, B K

    2006-05-01

    A 15-year-old girl with a history of Kawasaki disease was admitted to our nephrological department due to acute renal failure. Despite antibiotic therapy because of fever and the symptoms of a pharyngitis in the last few days, the girl showed persisting fever and developed arthralgias, an exanthema and a rising serum creatinine as well as anuria. A wide variety of differential diagnoses has to be thought of because of the history of the Kawasaki disease (symptoms like fever, pharyngitis, exanthema and arthralgia), i.e. hemolytic-uremic syndrome, vasculitis, ascending infection, postinfection glomerulonephritis. In consideration of etiologically unclear "rapidly progressive renal failure" with anuria and thrombocytopenia an immediate renal biopsy was done and revealed a severe drug induced acute interstitial nephritis. Due to this diagnosis we treated the patient with corticosteroids. Within 4 weeks serum creatinine declined to 1.8 mg/dl but did not normalize.

  17. Clinical spectrum and outcome of crescentic glomerulonephritis in children in developing countries.

    PubMed

    Dewan, Deepak; Gulati, Sanjeev; Sharma, Raj K; Prasad, Narayan; Jain, Manoj; Gupta, Amit; Kumar, Alok

    2008-03-01

    Crescentic glomerulonephritis (CsGN) is an uncommon entity in children. This prospective study was conducted to evaluate the aetiology, clinical spectrum and outcome in children with crescentic glomerulonephritis. The single-centre prospective study comprised of 22 children with biopsy proven CsGN who had been referred to our institute over the period January 2000 to December 2005. These patients were subjected to detailed clinical and biochemical examinations. The diagnosis of underlying renal disease was based on various criteria, including the clinical picture, serology and histopathology. The patients received intravenous methyl prednisolone, oral steroid treatment, and oral cyclophosphamide with or without plasmapheresis. All patients received supportive care, including control of hypertension and oedema and supportive management of renal insufficiency. During this 5-year period, CsGN accounted for 5.1% of all biopsies done in children. The mean age was 12.27 years (range 4 years to 18 years). There were eight girls and 14 boys. The mean duration of symptoms prior to referral was 2.47 months (range 5 days to 21 months). Aetiology was immune complex in 19 cases, anti-glomerular basement membrane (anti-GBM) antibody disease in two cases and pauci-immune (Wegener's granulomatosis) in one case. The percentage of crescents ranged from 50% to 100% (mean 70.6%). Twenty-one out of 22 (95.5%) children in our series had hypertension at presentation that required treatment with antihypertensive medications. The serum creatinine level at presentation ranged from 1.5 mg/dl to 11.4 mg/dl (mean 5.5 mg/dl). Of the 22 children, two were lost to follow-up, while the mean follow-up period of the rest of the 20 children was 8.13 months (range 1 month to 43 months). At the last follow-up of the 22 children, ten had stage 5 chronic kidney disease (CKD) and three had stage 4 CKD, while seven children had a calculated glomerular filtration rate (GFR) of >60 ml/min per 1.73 m(2) body

  18. Th1, Th2 and Treg/T17 cytokines in two types of proliferative glomerulonephritis

    PubMed Central

    Stangou, M.; Bantis, C.; Skoularopoulou, M.; Korelidou, L.; Kouloukouriotou, D.; Scina, M.; Labropoulou, I. T.; Kouri, N. M.; Papagianni, A.; Efstratiadis, G.

    2016-01-01

    IgA nephropathy (IgAN) and focal segmental necrotizing glomerulonephritis (FSNGN) are characterized by proliferation of native glomerular cells and infiltration by inflammatory cells. Several cytokines act as mediators of kidney damage in both diseases. The aim of the present study was to investigate the role of Th1, Th2 and Treg/T17 cytokines in these types of proliferative glomerulonephritis. Simultaneous measurement of Th1 interleukin (IL-2, IL-12, tumor necrosis factor-alpha [TNF-α], interferon-gamma [INF-γ]), Th2 (IL-4, IL-5, IL-6, IL-10, IL-13), Treg/T17 transforming growth factor-beta 1 (TGF-β1, granulocyte-macrophage colony-stimulating factor [GM-CSF], IL-17) cytokines and C-C chemokines Monocyte chemoattractant protein-1 (MCP-1, macrophage inflammatory protein-1 [MIP-1] β) was performed in first-morning urine samples, at the day of renal biopsy, using a multiplex cytokine assay. Cytokine concentrations were correlated with histological findings and renal function outcome. Urinary excretion of Th1, Th2 and Treg/Th17 cytokines were significantly higher in FSNGN compared to IgAN patients. In IgAN patients (n = 50, M/F: 36/14, M age: 40.7 [17–67] years), Th1, Th2 and T17 cytokines correlated significantly with the presence of endocapillary proliferation, while in FSNGN patients (n = 40, M/F: 24/16, M age: 56.5 [25–80] years), MCP-1 and TGF-β1 had a positive correlation with severe extracapillary proliferation (P = 0.001 and P = 0.002, respectively). Urinary IL-17 was the only independent parameter associated with endocapillary proliferation in IgAN and with MCP-1 urinary excretion in FSNGN. Response to treatment was mainly predicted by IL-6 in IgAN, and by Th2 (IL-4, IL-6), Treg (GM-CSF) cytokines and MIP-1 β in FSNGN. Th1, Th2 and T17 cytokines were directly implicated in renal pathology in IgAN and possibly through MCP-1 production in FSNGN. IL-17 and IL-6 seem to have a central role in inflammation and progression of kidney injury. PMID:27194829

  19. Expression of alternatively spliced fibronectin variants during remodeling in proliferative glomerulonephritis.

    PubMed Central

    Barnes, J. L.; Torres, E. S.; Mitchell, R. J.; Peters, J. H.

    1995-01-01

    Fibronectin (Fn) plays an important role in tissue remodeling during embryogenesis, wound repair, and vascular disease, and is thought to regulate cellular processes such as cell adhesion, migration, proliferation, and differentiation through specialized domains within the molecule. In addition, Fn can be alternatively spliced at three regions: extradomains EIIIA, EIIIB, and a variable segment V, potentially giving rise to functionally distinct variants of the molecule. We have previously shown a sequential expression of cellular Fn first by platelets, followed by macrophages, then mesangial cells in habu snake venom-induced proliferative glomerulonephritis (Am J Pathol 145: 585-597, 1994). These studies examined the cellular sources and glomerular localization of Fn in general but did not distinguish between the various alternatively spliced isoforms. In this study, we examine by in situ hybridization and immunohistochemistry the temporal expression and cellular sources of EIIIA, EIIIB, and V in a model of proliferation glomerulonephritis that has cell migration, proliferation, and extracellular matrix synthesis as features of tissue remodeling. Macrophages were the first cells to express Fn mRNA showing an EIIIA+, EIIIB-, and V95+ pattern beginning at 8 hours after habu snake venom injection. Migrating mesangial cells at the margins of early lesions (8 and 24 hours) did not overexpress mRNA encoding these Fn variants, but immunofluorescence microscopy revealed V95 and EIIIA protein at the margins of lesions. EIIIB was absent in lesions at this time. At 48 hours and peaking at 72 hours after habu snake venom injection, mesangial cells in central aspects of glomerular lesions expressed abundant mRNA and protein for V95 and EIIIA. EIIIB mRNA and protein was slight in the mesangium at these times. Parietal epithelial cells, particularly adjacent to glomerular lesions, also expressed abundant mRNA and protein for all three variants throughout the course of the disease

  20. Localization of the membrane attack complex (MAC) in experimental immune complex glomerulonephritis

    PubMed Central

    1983-01-01

    The role of the membrane attack complex (MAC) as a mediator of renal tissue injury was evaluated in rats affected by bovine serum albumin (BSA)-induced immune complex glomerulonephritis. Immunofluorescence studies revealed concurrent deposits of IgG, BSA, C3, and the MAC along glomerular capillary walls, although the MAC manifested a more restricted distribution than that observed for immune complexes. Immunoelectron microscopic techniques were utilized to demonstrate immune complexes, C3, and the MAC within dense deposits in the subepithelial aspect of the basement membrane. Visceral epithelial foot processes were fused in areas overlying large dense deposits and exhibited intense staining for the MAC, lesser reactivity for C3 but IgG was absent from the foot process membranes. Smaller granular deposits of immune complexes, C3, and the MAC were observed in the subendothelial region of the lamina rara interna and the lamina densa. Immune complexes may activate the classical complement pathway causing diffuse injury to the glomerular basement membrane (GBM), allowing subepithelial accumulation of complexes. These observations implicate the MAC as a mediator of GBM and juxtaposed podocyte membrane injury, thereby contributing to disruption of the glomerular filtration barrier. IgG and C3 were demonstrated within tubulointerstitial regions on the surface of collagen fibers in close proximity to the tubular basement membrane (TBM) of proximal convoluted tubules. Within the TBM, C3 localization was prominent with diminished reactivity for the MAC, but IgG was not detectable. The demonstration of C3 and scant MAC deposits in the TBM of nonimmunized control rats without evidence of interstitial IgG and C3 deposits suggests that both nonimmune and immune processes play a role in the pathogenesis of extraglomerular lesions. Evidence derived from these morphologic studies indicates that the MAC is associated with injury to the GBM, foot process membranes of visceral

  1. A Method of Identifying AGNs Based on Emission-Line Excess and the Nature of Low-Luminosity AGNs in the Sloan Digital Sky Survey. II. The Nature of Low-Luminosity AGNs

    NASA Astrophysics Data System (ADS)

    Tanaka, Masayuki

    2012-04-01

    We have developed a new method of identifying active galactic nuclei (AGNs) and studied the nature of low-luminosity AGNs in the Sloan Digital Sky Survey. This is the latter part of a series of papers in which we consider correlations between the AGN activities and the host-galaxy properties. Based on a sample of AGNs identified by a new method developed in the former part (2012, PASJ, 64, 36), we found that AGNs typically show extinction of τV = 1.2, and exhibit a wide range of ionization levels. The finding of ionization levels motivated us to use [O II] + [O III] as an indicator of AGN power. We found that AGNs are preferentially located in massive, red, early-type galaxies. Taking into account a selection bias of the Oxygen-excess method, we showed that strong AGNs are located in active star-forming galaxies, and that rapidly growing super-massive black holes are located in rapidly growing galaxies, which clearly shows the coevolution of super-massive black holes and their host galaxies. This is a surprising phenomenon, given that the growths of black holes and host galaxies occur on their respective physical scales which are very different. Interestingly, the AGN power does not strongly correlate with the host-galaxy mass. It seems that the mass works as a ``switch'' for activating AGNs. The absence of AGNs in low-mass galaxies might be due to the absence of super-massive black holes there, but a dedicated observation of the nuclear region of nearby low-mass galaxies would be necessary to obtain a deeper insight into it.

  2. Review of Space VLBI RadioAstron studies of AGN

    NASA Astrophysics Data System (ADS)

    Gurvits, Leonid; Kovalev, Yuri

    2016-07-01

    Space VLBI offers an unrivalled resolution in studies of the AGN phenomena. Since 2011, the Russia-led SVLBI mission RadioAstron conducts observations at 92, 18, 6 and 1.3 cm with baselines an order of magnitude longer than the Earth diameter, therefore offering an order of magnitude "sharper" view at the brightest radio sources than achieved with Earth-based VLBI systems. In our presentation we will review the current status of the RadioAstron's scientific programme. Over the first 4.5 years of the in-orbit operations, the mission achieved successful VLBI detections of extragalactic continuum radio sources at all four observing bands. To date, detections on SVLBI baselines have been obtained for more than 150 AGN's at projected baselines up to 350 000 km (about 28 Earth diameters, ED). The highest resolution achieved is 14 microarcscends from 1.3 cm observations. RadioAstron is an international project; it conducts observations with up to 30 Earth-based radio telescopes located on different continents. We will review results of total intensity and polarisation imaging with extreme angular resolution of blazars and nearby active galaxies. We will also discuss typical and maximum brightness temperatures of blazar cores from the AGN Survey obtained with RadioAstron. Physical implications for the AGN jets formation, magnetic field and emission mechanism will be discussed on the basis of the results obtained to date.

  3. The Evolution of the AGN population in the MORGANA model

    NASA Astrophysics Data System (ADS)

    Fontanot, F.; Monaco, P.; Cristiani, S.; Tozzi, P.

    2008-10-01

    We present the results of the MOdel for the Rise of Galaxies aNd Agns (MORGANA), that includes in a self-consistent way the accretion of matter onto Super-Massive Black Holes. We compare MORGANA predictions to the observed evolution of the AGN space density (inferred from optical and X-ray surveys) and we find that that it is possible to reproduce the apparent downsizing of the AGN population in the framework of concordance cosmology. We will show that this result is likely due to the improved treatment of gas cooling and feedback in MORGANA, and in particular to the modeling of the stellar kinetic feedback, arising in star-forming bulges as a consequence of the level of turbolence. On the other hand, the predicted low-mass end of BH-bulge relation is steeper than observed: we discuss this disagreement on the light of the predicted excess of small bulges, which is common to several models of galaxy formation and evolution. Finally we will show that a stronger constrain on the relative importance of the physical processes involved in the build up of the AGN population move from the observed redshift evolution of the BH-Bulge relation.

  4. Fast Ionized X-ray Absorbers in AGNs

    NASA Astrophysics Data System (ADS)

    Fukumura, K.; Tombesi, F.; Kazanas, D.; Shrader, C.; Behar, E.; Contopoulos, I.

    2015-07-01

    We present a study of X-ray ionization of MHD accretion-disk wind models in an effort to explain the highly-ionized ultra-fast outflows (UFOs) identified as X-ray absorbers recently detected in various sub-classes of Seyfert AGNs. Our primary focus is to show that magnetically-driven outflows are physically plausible candidates to account for the AGN X-ray spectroscopic observations. We calculate its X-ray ionization and the ensuing X-ray absorption line spectra in comparison with an XXM-Newton/EPIC spectrum of the narrow-line Seyfert AGN, PG 1211+143. We find, through identifying the detected features with Fe Kα transitions, that the absorber has a characteristic ionization parameter of log(xi[erg cm/s]) = 5-6 and a hydrogen-equivalent column density on the order of 1e23 cm-2, outflowing at a sub-relativistic velocity of v/c = 0.1-0.2. The best-fit model favors its radial location at R = 200 Rs (Rs is the Schwarzschild radius), with a disk inner truncation radius at Rt = 30Rs. The overall K-shell feature in data is suggested to be dominated by Fe XXV with very little contribution from Fe XXVI and weakly-ionized iron, which is in a good agreement with a series of earlier analysis of the UFOs in various AGNs including PG 1211+143.

  5. Converting the Audience: A Conversation with Agnes Wilcox

    ERIC Educational Resources Information Center

    Becker, Becky

    2006-01-01

    This article presents a conversation with Agnes Wilcox, Executive Director of Prison Performing Arts in St. Louis, Missouri, about Prison Performing Arts. Although the average person might balk at the notion of interacting with prison inmates, finding it intimidating, worrisome, or self-sacrificial, for Wilcox, Prison Performing Arts is a…

  6. X-Ray Selected AGN in A Merging Cluster

    NASA Astrophysics Data System (ADS)

    Taylor, Joanna M.; Norman, D.; Soechting, I.; Coldwell, G.

    2012-01-01

    We investigate the X-ray AGN population and evolution in the merging galaxy cluster DLSCL J0522.2-4820 discovered via weak gravitational lensing shear from the Deep Lens Survey (DLS). Since weak lensing shear is dependent only on mass, it does not introduce the biases that typical cluster selection methods do. This cluster is of particular interest due to both its extended multiple X-ray emission peaks and the large number of X-ray point sources identified in the field. We measured the redshifts of X-ray AGN as well as cluster galaxies in order to investigate the 3-dimensional distribution and possible clustering of AGN in galaxy clusters. Of the 125 objects in our sample, 54 are galaxies in the cluster; the cluster redshift is determined to be z=0.2997±0.0096. This agrees well with a previous value of z=0.296±0.001. We identified several broad line AGN at high redshift including a quasar pair at redshift z=1.8. Currently, we have found no X-ray point sources to be within the cluster. This project was supported by the NOAO/KPNO Research Experiences for Undergraduates (REU) Program which is funded by the National Science Foundation Research Experiences for Undergraduates Program and the Department of Defense ASSURE program through Scientific Program Order No. 13 (AST-0754223) of the Cooperative Agreement No. AST-0132798 between the Association of Universities for Research in Astronomy (AURA) and the NSF.

  7. First Results from the NuSTAR AGN Physics Program

    NASA Astrophysics Data System (ADS)

    Brenneman, Laura; Fuerst, F.; Matt, G.; Walton, D.; Madejski, G. M.; Marinucci, A.; Elvis, M.; Risaliti, G.; Harrison, F.; Stern, D.; Boggs, S.; Christensen, F.; Craig, W. W.; Zhang, W.; NuSTAR Team

    2013-04-01

    The Nuclear Spectroscopic Telescope Array (NuSTAR, launched June 2012) is revolutionizing our knowledge of the physics at work in active galactic nuclei (AGN). With its high collecting area, focusing optics and low background from 3-79 keV, NASA's newest X-ray observatory is providing an unprecedented look at the spectral and timing properties of AGN in this energy range, which have been notoriously difficult to access. NuSTAR has observed several AGN to date simultaneously with XMM-Newton, Suzaku and/or Swift for the purposes of understanding their coronal properties (e.g., plasma temperature, optical depth) and measuring the spins of their supermassive black holes. We present the first results from these observing campaigns, highlighting the spectral and timing analysis of the bright, nearby AGN IC 4329A, NGC 4151, NGC 1365 and MCG--6-30-15. These are the highest signal-to-noise datasets ever obtained across the 0.2-79 keV energy band for these three sources, allowing us to cleanly deconvolve the X-ray continuum, absorption and reflection components in each galaxy for the first time via time-averaged and time-resolved spectroscopy.

  8. Radio-AGN feedback: when the little ones were monsters

    NASA Astrophysics Data System (ADS)

    Williams, W. L.; Röttgering, H. J. A.

    2015-06-01

    We present a study of the evolution of the fraction of radio-loud active galactic nuclei (AGN) as a function of their host stellar mass. We make use of two samples of radio galaxies: one in the local Universe, 0.01 < z ≤ 0.3, using a combined SDSS-NVSS (Sloan Digital Sky Survey NRAO Very Large Array Sky Survey) sample and the other at higher redshifts, 0.5 < z ≤ 2, constructed from the VLA-COSMOS_DEEP Radio Survey at 1.4 GHz and a Ks-selected catalogue of the COSMOS/UltraVISTA field. We observe an increase of more than an order of magnitude in the fraction of lower mass galaxies (M* < 1010.75 M⊙) which host radio-loud AGN with radio powers P1.4 GHz > 1024 W Hz-1 at z ˜ 1-2 while the radio-loud fraction for higher mass galaxies (M* > 1011.25 M⊙) remains the same. We argue that this increase is driven largely by the increase in cold or radiative mode accretion with increasing cold gas supply at earlier epochs. The increasing population of low-mass radio-loud AGN can thus explain the upturn in the radio luminosity function at high redshift which is important for understanding the impact of AGN feedback in galaxy evolution.

  9. Feedback from AGN: The Kinetic/Radio Luminosity Function

    NASA Astrophysics Data System (ADS)

    Melini, Gabriele; La Franca, Fabio; Fiore, Fabrizio

    2010-05-01

    We have measured the probability distribution function of the ratio RX = log L1.4/LX, where L1.4/LX = ν Lν(1.4 GHz)/LX(2-10 keV), between the 1.4 GHz and the unabsorbed 2-10 keV luminosities and its dependence on LX and z. We have used a complete sample of ~1800 hard X-ray selected AGN, observed in the 1.4 GHz band, cross-correlated in order to exclude FR II-type objects, and thus obtain a contemporaneous measure of the radio and X-ray emission. The distribution P(RX|LX,z) is shown in Figure 1. Convolution of the distribution P(RX|LX,z) with the 2-10 keV X-ray AGN luminosity function from La Franca et al. (2005) and the relations between radio power and kinetic energy from Best et al. (2006) and Willott et al. (1999) allows us to derive the AGN kinetic power and its evolution. As shown in Figure 1, our results are in good agreement with the predictions of the most recent models of galaxy formation and evolution (e.g., Croton et al. 2006), where AGN radio feedback is required to quench the star formation.

  10. Fast ionized X-ray absorbers in AGNs

    NASA Astrophysics Data System (ADS)

    Fukumura, K.; Tombesi, F.; Kazanas, D.; Shrader, C.; Behar, E.; Contopoulos, I.

    2016-05-01

    We investigate the physics of the X-ray ionized absorbers often identified as warm absorbers (WAs) and ultra-fast outflows (UFOs) in Seyfert AGNs from spectroscopic studies in the context of magnetically-driven accretion-disk wind scenario. Launched and accelerated by the action of a global magnetic field anchored to an underlying accretion disk around a black hole, outflowing plasma is irradiated and ionized by an AGN radiation field characterized by its spectral energy density (SED). By numerically solving the Grad-Shafranov equation in the magnetohydrodynamic (MHD) framework, the physical property of the magnetized disk-wind is determined by a wind parameter set, which is then incorporated into radiative transfer calculations with xstar photoionization code under heating-cooling equilibrium state to compute the absorber's properties such as column density N_H, line-of-sight (LoS) velocity v, ionization parameter ξ, among others. Assuming that the wind density scales as n ∝ r-1, we calculate theoretical absorption measure distribution (AMD) for various ions seen in AGNs as well as line spectra especially for the Fe Kα absorption feature by focusing on a bright quasar PG 1211+143 as a case study and show the model's plausibility. In this note we demonstrate that the proposed MHD-driven disk-wind scenario is not only consistent with the observed X-ray data, but also help better constrain the underlying nature of the AGN environment in a close proximity to a central engine.

  11. Unveiling the physics of AGN through X-ray variability

    NASA Astrophysics Data System (ADS)

    Hernández-García, L.; González-Martín, O.; Masegosa, J.; Márquez, I.

    2017-03-01

    Although variability is a general property characterizing active galactic nuclei (AGN), it is not well established whether the changes occur in the same way in every nuclei. The main purpose of this work is to study the X-ray variability pattern(s) in AGN selected at optical wavelengths in a large sample, including low ionization nuclear emission line regions (LINERs) and type 1.8, 1.9, and 2 Seyferts, using the public archives in Chandra and/or XMM–Newton. Spectra of the same source gathered at different epochs were simultaneously fitted to study long term variations; the variability patterns were studied allowing different parameters to vary during the spectral fit. Whenever possible, short term variations from the analysis of the light curves and long term UV flux variability were studied. Variations at X-rays in timescales of months/years are very common in all AGN families but short term variations are only found in type 1.8 and 1.9 Seyferts. The main driver of the long term X-ray variations seems to be related to changes in the nuclear power. Other variability patterns cannot be discarded in a few cases. We discuss the geometry and physics of AGN through the X-ray variability analysis.

  12. Membranoproliferative glomerulonephritis with isolated C3 deposits: case report and literature review.

    PubMed

    Darouich, Sihem; Goucha, Rym; Jaafoura, Mohamed Habib; Zekri, Semy; Kheder, Adel; Ben Maiz, Hédi

    2011-02-01

    Membranoproliferative glomerulonephritis with isolated C3 deposits (MPGNC3) is an uncommon condition characterized by overt glomerular C3 deposits in the absence of immunoglobulins and intramembranous dense deposits. Here the authors describe the clinical and morphological features of primary MPGNC3 in a 13-year-old boy and critically review the previously published cases. The patient presented with nephrotic syndrome and microscopic hematuria. Blood tests revealed very low circulating C3 levels. The renal biopsy exhibited subendothelial, subepithelial, and mesangial deposits, with C3 but not immunoglobulins seen on immunofluorescence. This case and the review of the literature indicate that the serum complement profile with decreased levels of C3 and normal levels of classical pathway components together with glomerular deposits containing exclusively complement C3 is highly suggestive of alternative pathway activation. The diagnosis of acquired and/or genetic complement abnormalities in some cases supports that complement dysregulation is implicated in the pathogenesis of MPGNC3. Such data show great promise to provide new therapy strategies based on modulation of the complement system activity.

  13. Effects of pegylated interferon alpha-2a on hepatitis-C-virus-associated glomerulonephritis.

    PubMed

    Sugiura, Tokio; Yamada, Takuji; Kimpara, Yuri; Fujita, Naoya; Goto, Kenji; Koyama, Norihisa

    2009-01-01

    Hepatitis C virus (HCV) infection leads to chronic liver disease, but it has also been associated with extrahepatic manifestations. Membranoproliferative glomerulonephritis (MPGN) is the most common renal disease associated with HCV. Although renal disease related to HCV in adults has been well studied, it has not been well studied in children because it is rare. A recent study found that antiviral therapy was effective for adult patients with HCV-associated MPGN. We report a 9-year-old girl with HCV-associated MPGN. Her HCV genotype was 1b, and her virus load was high. The first renal biopsy showed mesangial proliferation and partial double contours of the basement membrane on light microscopy and immunofluorescence staining with immunoglobulin (Ig) M, IgG, and C3. The patient was successfully treated with pegylated interferon (IFN) alpha-2a monotherapy. The antiviral therapy was generally well tolerated. After antiviral therapy, a sustained virological response-defined as negative HCV ribonucleic acid (RNA) at least 24 weeks after antiviral treatment-was achieved, the proteinuria disappeared, and the second renal biopsy showed improvement.

  14. IgA glomerulonephritis (Berger's disease): evidence of high serum levels of polymeric IgA.

    PubMed

    Trascasa, M L; Egido, J; Sancho, J; Hernando, L

    1980-11-01

    Eleven out of 15 patients with IgA mesangial glomerulonephritis (Berger's disease) had an increased proportion of serum IgA in 9-21S fractions on 5-40% sucrose density-gradient ultracentrifugation; the heavier fractions decreased at acid pH. Serum IgA purified by starch electrophoresis was subjected to reduction-alkylation yielding fragments of lower molecular weight. J chain was detected on urea alkaline polyacrylamide electrophoresis and the high-molecular weight IgA bound the human secretory component. In six patients treated with phenytoin for 1 year there was a decrease in polymeric IgA and an increase in monomeric IgA adopting a pattern similar to that of the controls. Our results show the presence of a large amount of true IgA polymers, partially as immune complexes, in the serum of patients with Berger's disease. These data together with their normalization after phenytoin treatment may open a new pathogenic and therapeutic approach to this entity.

  15. Hereditary C2 deficiency and systemic lupus erythematosus associated with severe glomerulonephritis.

    PubMed Central

    Roberts, J L; Schwartz, M M; Lewis, E J

    1978-01-01

    Although an unusually high incidence of immunological diseases has been described in patients with hereditary C2 deficiency, the severity of these illnesses has been relatively mild, suggesting that blocking complement activation beyond C4 may protect against significant complement-mediated inflammation. This report describes studies in a C2-deficient patient with severe systemic lupus erythematosus (SLE) and diffuse proliferative glomerulonephritis. An immunopathological study of the kidney revealed the deposition of properdin, properdin factor B, C3 and C5 in a pattern similar to immunoglobulin G deposits. Serum properdin and properdin factor B levels were low at various times during the patient's course. In vitro complement fixation studies showed C3 fixation by glomerular deposits could occur via the alternative pathway. Studies of the immune deposits in the patients' skin revealed similar results. These studies suggest that inflammation may be effectively mediated via the alternative complement pathway in the C2 deficiency-lupus syndrome. Images FIG. 1 FIG. 2 FIG. 3 FIG. 4 PMID:348363

  16. Post-reperfusion rapidly progressive glomerulonephritis in post-transplant IgA nephropathy.

    PubMed

    Tovbin, David; Shnaider, Alla; Kachko, Leonid; Basok, Anna; Vorobiov, Marina; Rogachev, Boris; Abramov, Dan; Zlotnik, Moshe

    2004-01-01

    Rapidly progressive glomerulonephritis (RPGN) is a rare occurrence in IgA nephropathy (IgAN) in renal transplant patients on immunosuppressive therapy. RPGN post ischemia-reperfusion has not been previously reported. We report a 62 year old male patient on azathioprine therapy, 9 years after left cadaveric renal transplantation due to end stage renal disease of unknown etiology, who presented with progressive deterioration in renal function and hematuria. Renal biopsy was consistent with IgAN. Duplex and CT scan demonstrated a decreased renal graft perfusion, due to severe atherosclerosis and stenosis of iliac arteries. The patient underwent left axilo-femoral bypass graft surgery with improvement in kidney graft perfusion and function. However, few weeks later, patient presented with pulmonary edema and advanced renal failure and he was initiated on hemodialysis. Repeated renal biopsy demonstrated crescentic GN. To the best of our knowledge, this is the first report of RPGN following reversal of ischemia and reperfusion. There was no evidence for atherembolic disease which is not uncommon after vascular surgery and it has been reported to be rarely associated to crescentic GN. Theoretical explanations for exacerbation of IgAN to crescentic GN, following successful reperfusion, could be enhancement of capillary damage, inflammation and oxidative stress. Putative mechanisms for these phenomena may be interaction of reperfusion-induced hyperfiltration, high intraglomerular capillary pressure, oxidative stress, increased polymorphonucler cells infiltration and inflammation; the presence of IgA immune deposits and azathioprine metabolites, both can also be associated to enhancement of oxidative stress.

  17. Amelioration of immune complex-mediated glomerulonephritis by synthetic protease inhibitors.

    PubMed

    Jennette, J C; Tidwell, R R; Geratz, J D; Bing, D H; Falk, R J

    1987-06-01

    Proteases are involved in the pathogenesis of inflammatory diseases by participating in the activation of mediator systems and by producing proteolytic tissue injury. Homeostatic control of inflammation is accomplished in part by physiologic protease inhibitors. The authors investigated the effectiveness of a number of synthetic protease inhibitors in ameliorating the glomerular injury induced by immune complex-mediated glomerulonephritis in mice. Two amidine-type protease inhibitors, bis (5-amidino-2-benzimidazolyl)methane and 1,2-bis (5-amidino-2-benzimidazolyl)ethane, had the greatest effects. They caused a marked reduction in glomerular necrosis (P less than 0.001) but did not affect the amount or site of immune complex localization or leukocyte influx. The inhibition constants of the protease inhibitors against nine purified physiologic proteases were determined. These results were discussed in relation to the effectiveness of the protease inhibitors in reducing glomerular injury. This investigation indicates that the administration of synthetic protease inhibitors can have a beneficial effect on immune-mediated inflammatory injury.

  18. Histological, immunohistochemical and biological data in assessing interstitial fibrosis in patients with chronic glomerulonephritis.

    PubMed

    Bob, Flaviu Raul; Gluhovschi, Gheorghe; Herman, Diana; Potencz, Elena; Gluhovschi, Cristina; Trandafirescu, Virginia; Schiller, Adalbert; Petrica, Ligia; Velciov, Silvia; Bozdog, Gheorghe; Vernic, Corina

    2008-01-01

    The aim of this study was to determine the relationship between histological, immunohistochemical (IHC) and biological data in the assessment of interstitial fibrosis in patients with glomerular diseases. A group of 41 patients with primary and secondary glomerulonephritis was studied. In order to quantify the histological changes and to assess the extent of active-inflammatory and chronic-sclerotic/fibrotic interstitial lesions, we adapted a scoring system, initially used for lupus nephritis, and ANCA-associated vasculitis. IHC labeling procedures with monoclonal antibodies anti-smooth muscle actin (SMA), anti-vimentin and anti-transforming growth factor beta (TGFbeta) were assessed using a semi-quantitative score, correlated with the histological and biological data. Our results showed that interstitial labeling of SMA correlated with scores for sclerotic/fibrotic lesions (chronicity index) and with active-inflammatory lesions (interstitial infiltrate, activity index). Interstitial vimentin correlated with the score for interstitial infiltrate. Both interstitial vimentin and TGFbeta immunopositivity correlated with sclerotic/fibrotic lesions (interstitial fibrosis, tubular atrophies, vascular hyalinosis/fibrosis, chronicity index), and negatively with glomerular filtration rate. An important correlation was found between the interstitial labeling of the two IHC markers of myofibroblasts (SMA and vimentin). We conclude that IHC studies related to clinico-biological and histological data can have an important role in the evaluation of the glomerular diseases, but the classical histological investigation assessed through quantification has still not lost its importance.

  19. A Case of Thyroid Storm Associated with Cardiomyopathy and Poststreptococcal Glomerulonephritis.

    PubMed

    Underland, Lisa J; Villeda, Gerson A Vallencia; Pal, Abhijeet; Lam, Leslie

    2016-01-01

    Thyroid storm has a high mortality rate and is often associated with a precipitating factor such as intercurrent illness or infection. It is rare in pediatric patients. Cardiac disease in hyperthyroidism mostly manifests itself as tachycardia but more serious cardiac findings have also been described. A 5-year-old male with recent strep throat infection presented with dilated cardiomyopathy, hematuria, and symptoms and lab findings consistent with severe hyperthyroidism. He was diagnosed with thyroid storm secondary to concurrent Graves' disease and poststreptococcal glomerulonephritis (PSGN). After starting the treatment with methimazole and a beta-blocker, his cardiac disease gradually improved and the PSGN resolved over time. There are no specific pediatric criteria for thyroid storm. Adult criteria can be difficult to apply to pediatric cases. Criteria for diagnosis of thyroid storm are less clear for pediatric patients. Dilated cardiomyopathy is a rare cardiac manifestation of hyperthyroidism. PSGN is due to glomerular immune complexes and can complicate group A strep infection. Providers should be aware of cardiac disease as a complication of hyperthyroidism. PSGN should not mechanistically be related to hyperthyroidism but can precipitate the signs of thyroid storm such as hypertension. This association has not been previously reported in the literature.

  20. Membranoproliferative glomerulonephritis. A prospective clinical trial of platelet-inhibitor therapy

    SciTech Connect

    Donadio, J.V. Jr.; Anderson, C.F.; Mitchell, J.C.; Holley, K.E.; Ilstrup, D.M.; Fuster, V.; Chesebro, J.H.

    1984-05-31

    Forty patients with Type I membranoproliferative glomerulonephritis were treated for one year with dipyridamole, 225 mg per day, and aspirin, 975 mg per day, in a prospective, randomized, double-blind, placebo-controlled study. At the base line, the half-life of /sup 51/Cr-labeled platelets was reduced in 12 of 17 patients. The platelet half-life became longer and renal function stabilized in the treated group, as compared with the placebo group, suggesting a relation between platelet consumption and the glomerulopathy. The glomerular filtration rate, determined by iothalamate clearance, was better maintained in the treated group (average decrease, 1.3 ml per minute per 1.73 m/sup 2/ of body-surface area per 12 months) than in the placebo group (average decrease, 19.6). Fewer patients in the treated group than in the placebo group had progression to end-stage renal disease (3 of 21 after 62 months as compared with 9 of 19 after 33 months). The data suggest that dipyridamole and aspirin slowed the deterioration of renal function and the development of end-stage renal disease.

  1. [A case of combination therapy with MMF and steroids for idiopathic membranoproliferative glomerulonephritis].

    PubMed

    Mori, Yutaro; Ihara, Katsuhito; Yamaguchi, Wakaba; Fujii, Tetsuro; Toda, Takayuki; Nagata, Michio; Matsui, Noriaki

    2013-01-01

    A 26-year-old man diagnosed with nephrotic syndrome was administered steroid monotherapy. Urinary protein excretion was 2-3 g/day despite the therapy. Percutaneous renal biopsy revealed Type I idiopathic membranoproliferative glomerulonephritis (IMPGN). Although intravenous steroid therapy at the dose of 1,000 mg/day for 3 days was administered, proteinuria persisted at the level of 1 g/day. Renal dysfunction (cystatin C, 1.33 mg/L) was evident. Strong inflammation was suggested by occult blood (3+) and urinary (red blood cells: 30-50/high power field) sediment. We considered steroid monotherapy to be ineffective, and initiated combina-tion therapy with mycophenolate mofetil (MMF) and steroids. Consequently, urinary protein excretion moderately decreased to 0.34 g/day without adverse events or worsening of the renal function. The steroid quantity could be reduced without relapse. Subsequently, we were able to reduce the dose of MMF gradually, then terminated the medication. IMPGN is a rare disease with a poor renal prognosis. Recently, MMF therapies for IMPGN have been attempted, but there are few cases in Japan. Our case suggests that combination therapy with MMF and steroids is effective and safe for treating IMPGN.

  2. Volatile Organic Metabolites Identify Patients with Mesangial Proliferative Glomerulonephritis, IgA Nephropathy and Normal Controls

    PubMed Central

    Wang, Changsong; Feng, Yue; Wang, Mingao; Pi, Xin; Tong, Hongshuang; Wang, Yue; Zhu, Lin; Li, Enyou

    2015-01-01

    Urinary volatile organic compounds (VOCs) analysis for kidney diseases has attracted a large amount of scientific interest recently, and urinary metabolite analysis has already been applied to many diseases. Urine was collected from 15 mesangial proliferative glomerulonephritis (MsPGN) patients, 21 IgA nephropathy (IgAN) patients and 15 healthy controls. Solid phase microextraction–chromatography– mass spectrometry (SPME-GC-MS) was used to analyse the urinary metabolites. The statistical methods principal component analysis (PCA) and orthogonal partial least-squares discriminant analysis (OPLSDA) were performed to process the final data. Five metabolites were significantly greater in the group of MsPGN patients than in the normal control group (P < 0.05) while three metabolites were found at increased levels in the group of IgAN patients compared with the normal controls (P < 0.05). In addition, five metabolites were significantly increased in the group of IgAN patients compared with the MsPGN patients (P < 0.05). These five metabolites may be specific biomarkers for distinguishing between MsPGN and IgAN. The analysis of urinary VOCs appears to have potential clinical applications as a diagnostic tool. PMID:26443483

  3. Enigma (partially) resolved: phospholipase A2 receptor is the cause of "idiopathic" membranous glomerulonephritis.

    PubMed

    Truong, Luan D; Seshan, Surya V

    2015-12-15

    Membranous glomerulonephritis (MGN) is a very significant kidney disease. It is one of the frequent causes of heavy protein excretion in urine. MGN is thought to be an immune-mediated disease caused by glomerular deposition of antigen-antibody complexes. The pathogenic antigen, however, has been an enigma until recently. It was discovered in 2009 that phospholipase A2 receptor (PLA2R), a normal transmembrane protein in podocyte plasma membrane, is the antigen causing MGN. Within 5 yr of its discovery, this seminal finding has leaded to novel insights into the treatment of this disease including diagnosis, therapy, and prediction of outcome. This finding also paves the way for fundamental studies on how and why autoimmunity against PLA2R develops. The discovery of PLA2A as the cause of "idiopathic" MGN after a half century of speculation, followed by further fundamental insights with such an expedient and successful application in patient care, embodies the elegance of science at its junction with society. This perspective traces the story of this remarkable discovery.

  4. A radio view of high-energy emitting AGNs

    NASA Astrophysics Data System (ADS)

    Schulz, Robert Frank

    2016-07-01

    Active galactic nuclei (AGNs) are among the most energetic objects in the Universe. These galaxies that are dominated in part or even throughout the electromagnetic spectrum by emission from their central, compact region. AGNs are extensively studied by multi-wavelength observations. In the standard picture, the main driver of an AGN is a supermassive black hole (SMBH) in its centre that is surrounded by an accretion disk. Perpendicular to the disk, in the vicinity of highly magnetized SMBH relativistic outflows of plasma, so-called jets, can form on either side that can reach far beyond the host galaxy. Only about 10% of all AGNs are dominated by emission from these jets due to relativistic beaming effects and these so-called blazars dominate the extragalactic gamma-ray sky. It is commonly accepted that the low-energy emission (radio to UV/X-ray) is due to synchrotron emission from the jet. The high-energy emission is considered to stem from inverse-Compton scattering of photons on the jet particles, but different sources for these photons are discussed (internal or external to the AGN) and other models for the high-energy emission have also been proposed. The nature of the high-energy emission is strongly linked to the location of the emission region in the jet which requires a detailed understanding of the formation and evolution of jets. Radio observations especially using very long baseline interferometry (VLBI) provide the best way to gain direct information on the intrinsic properties of jets down to sub-pc scales, close to their formation region. In this thesis, I focus on the properties of three different AGNs, IC 310, PKS2004-447, and 3C 111 that belong to the small non-blazar population of gamma-ray-loud AGNs. I study them in detail with a variety of radio astronomical instruments with respect to their high-energy emission and in the context of the large monitoring programmes MOJAVE (Monitoring Of Jets in Active galactic nuclei with VLBA Experiments) and

  5. Understanding AGNs in the Local Universe through Optical Reverberation Mapping

    NASA Astrophysics Data System (ADS)

    Pei, Liuyi

    2016-01-01

    I present the results of observational projects aimed at measuring the mass of the black hole at the center of active galactic nuclei (AGNs) and understanding the structure and kinematics of the broad-line emitting gas within the black hole's sphere of influence.The first project aims to measure the black hole mass in the Kepler-field AGN KA1858. We obtained simultaneous spectroscopic data from the Lick Observatory 3-m telescope using the Kast Double Spectrograph and photometry data from five ground-based telescopes, and used reverberation mapping (RM) techniques to measure the emission-line light curves' lags relative to continuum variations. We obtained lags for H-beta, H-gamma, H-delta, and He II, and obtained the first black hole mass measurement for this object. Our results will serve as a reference point for future studies on relations between black hole mass and continuum variability characteristics using Kepler AGN light curves.The second project, in collaboration with the AGN STORM team, aims to understand the structure and dynamics of the broad line region (BLR) in NGC 5548 in both UV and optical wavelengths. To supplement 6 months of HST UV observations, we obtained simultaneous optical spectroscopic data from six ground-based observatories. We obtained emission-line lags for the optical H-beta and He II lines as well as velocity-resolved lag measurements for H-beta. We also compared the velocity-resolved lags for H-beta to the UV emission lines C IV and Ly-alpha and found similar lag profiles for all three lines.Finally, I will discuss my contributions to two other collaborations in AGN RM. A key component in RM is monitoring continuum variability, which is often done through ground-based photometry. I will present a pipeline that performs aperture photometry on any number of images of an AGN with WCS coordinates and immediately produces relative light curves. This pipeline enables quick looks of AGN variability in real time and has been used in the

  6. Incidence of WISE-Selected Obscured AGNs in Major Mergers and Interactions from the SDSS

    NASA Astrophysics Data System (ADS)

    Weston, Madalyn; McIntosh, Daniel H.; Brodwin, Mark; Mann, Justin; Cooper, Andrew; McConnell, Adam; Nielson, Jennifer L.

    2017-01-01

    We use the Wide-field Infrared Survey Explorer (WISE) and the Sloan Digital Sky Survey (SDSS) to confirm a connection between dust-obscured active galactic nuclei (AGNs) and galaxy merging. Using a new, volume-limited (z≤0.08) catalog of visually-selected major mergers and galaxy-galaxy interactions from the SDSS, with stellar masses above 2×10^10 M⊙, we find that major mergers (interactions) are 5--17 (3--5) times more likely to have red [3.4]-[4.6] colors associated with dust-obscured or `dusty' AGNs, compared to non-merging galaxies with similar masses. Using published fiber spectral diagnostics, we map the [3.4]-[4.6] versus [4.6]-[12] colors of different emission-line galaxies and find one-quarter of Seyferts have colors indicative of a dusty AGN. We find that AGNs are five times more likely to be obscured when hosted by a merging galaxy, half of AGNs hosted by a merger are dusty, and we find no enhanced frequency of optical AGNs in merging over non-merging galaxies. We conclude that undetected AGNs missed at shorter wavelengths are at the heart of the ongoing AGN-merger connection debate. The vast majority of mergers hosting dusty AGNs are star-forming and located at the centers of Mhalo<10^13 M⊙ groups. Assuming plausibly short duration dusty-AGN phases, we speculate that a large fraction of gas-rich mergers experience a brief obscured AGN phase, in agreement with the strong connection between central star formation and black hole growth seen in merger simulations. We will use the WISE-selected AGNs (and AGNs selected by other methods) to perform SED analysis of mergers and interactions and dissect the SEDs to disentangle AGN and SF activity.

  7. Host Galaxy Properties of the Swift BAT Ultra Hard X-Ray Selected AGN

    NASA Technical Reports Server (NTRS)

    Koss, Michael; Mushotzky, Richard; Veilleux, Sylvain; Winter, Lisa M.; Baumgartner, Wayne; Tueller, Jack; Gehrels, Neil; Valencic, Lynne

    2011-01-01

    We have assembled the largest sample of ultra hard X-ray selected (14-195 keV) AGN with host galaxy optical data to date, with 185 nearby (z<0.05), moderate luminosity AGN from the Swift Burst Alert Telescope (BAT) sample. The BAT AGN host galaxies have intermediate optical colors (u -- r and g -- r) that are bluer than a comparison sample of inactive galaxies and optically selected AGN from the Sloan Digital Sky Survey (SDSS) which are chosen to have the same stellar mass. Based on morphological classifications from the RC3 and the Galaxy Zoo, the bluer colors of BAT AGN are mainly due to a higher fraction of mergers and massive spirals than in the comparison samples. BAT AGN in massive galaxies (log Stellar Mass >10.5) have a 5 to 10 times higher rate of spiral morphologies than in SDSS AGN or inactive galaxies. We also see enhanced far-IR emission in BAT AGN suggestive of higher levels of star formation compared to the comparison samples. BAT AGN are preferentially found in the most massive host galaxies with high concentration indexes indicative of large bulge-to-disk ratios and large supermassive black holes. The narrow-line (NL) BAT AGN have similar intrinsic luminosities as the SDSS NL Seyferts based on measurements of [O III] Lambda 5007. There is also a correlation between the stellar mass and X-ray emission. The BAT AGN in mergers have bluer colors and greater ultra hard X-ray emission compared to the BAT sample as whole. In agreement with the Unified Model of AGN, and the relatively unbiased nature of the BAT sources, the host galaxy colors and morphologies are independent of measures of obscuration such as X-ray column density or Seyfert type. The high fraction of massive spiral galaxies and galaxy mergers in BAT AGN suggest that host galaxy morphology is related to the activation and fueling of local AGN.

  8. Fraction of the X-ray selected AGNs with optical emission lines in galaxy groups

    NASA Astrophysics Data System (ADS)

    Li, Feng; Yuan, Qirong; Bian, Weihao; Chen, Xi; Yan, Pengfei

    2017-04-01

    Compared with numerous X-ray dominant active galactic nuclei (AGNs) without emission-line signatures in their optical spectra, the X-ray selected AGNs with optical emission lines are probably still in the high-accretion phase of black hole growth. This paper presents an investigation on the fraction of these X-ray detected AGNs with optical emission-line spectra in 198 galaxy groups at z<1 in a rest frame 0.1-2.4 keV luminosity range 41.3 < log(LX/erg s^{-1}) < 44.1 within the Cosmological Evolution Survey (COSMOS) field, as well as its variations with redshift and group richness. For various selection criteria of member galaxies, the numbers of galaxies and the AGNs with optical emission lines in each galaxy group are obtained. It is found that, in total 198 X-ray groups, there are 27 AGNs detected in 26 groups. AGN fraction is on average less than 4.6 (±1.2)% for individual groups hosting at least one AGN. The corrected overall AGN fraction for whole group sample is less than 0.98 (±0.11) %. The normalized locations of group AGNs show that 15 AGNs are found to be located in group centers, including all 6 low-luminosity group AGNs (L_{ 0.5-2 keV} < 10^{42.5} erg s^{-1}). A week rising tendency with z are found: overall AGN fraction is 0.30-0.43% for the groups at z<0.5, and 0.55-0.64% at 0.5 < z < 1.0. For the X-ray groups at z>0.5, most member AGNs are X-ray bright, optically dull, which results in a lower AGN fractions at higher redshifts. The AGN fraction in isolated fields also exhibits a rising trend with redshift, and the slope is consistent with that in groups. The environment of galaxy groups seems to make no difference in detection probability of the AGNs with emission lines. Additionally, a larger AGN fractions are found in poorer groups, which implies that the AGNs in poor groups might still be in the high-accretion phase, whereas the AGN population in rich clusters is mostly in the low-accretion, X-ray dominant phase.

  9. Modeling the reverberation of optical polarization in AGN

    NASA Astrophysics Data System (ADS)

    Rojas Lobos, P. A.; Goosmann, R.; Marin, F.

    2016-12-01

    According to the standard paradigm, the strong and compact luminosity of active galactic nuclei (AGN) is due to multi-temperature black body emission originating from an accretion disk formed around a supermassive black hole. This central engine is thought to be surrounded by a dusty region along the equatorial plane and by ionized winds along the poles. The innermost regions cannot yet be resolved neither in the optical nor in the infrared and it is fair to say that we still lack a satisfactory understanding of the physical processes, geometry and composition of the central (sub-parsec) components of AGN. Like spectral or polarimetric observations, the reverberation data needs to be modeled in order to infer constraints on the AGN geometry (such as the inner radius or the half-opening angle of the dusty torus). In this research note, we present preliminary modeling results using a time-dependent Monte Carlo method to solve the radiative transfer in a simplified AGN set up. We investigate different model configurations using both polarization and time lags and find a high dependency on the geometry to the time-lag response. For all models there is a clear distinction between edge-on or face-on viewing angles for fluxes and time lags, the later showing a higher wavelength-dependence than the former. Time lags, polarization and fluxes point toward a clear dichotomy between the different inclinations of AGN, a method that could help us to determine the true orientation of the nucleus in Seyfert galaxies.

  10. Recurrent Proliferative Glomerulonephritis With Monoclonal IgG Deposits After a Renal Transplant Which Was Insensitive to Pulse Therapy Remitted by Double Filtration Plasmapheresis.

    PubMed

    Wu, Di; Chen, Jin-Song; Cheng, Dong-Rui; Chen, Hao; Li, Xue; Ji, Shu-Ming; Xie, Ke-Nan; Ni, Xue-Feng; Liu, Zhi-Hong; Wen, Ji-Qiu

    2015-10-01

    Proliferative glomerulonephritis with monoclonal IgG deposits manifesting as a nephrotic syndrome recently has been described as a renal disease with the pathological features of mesangial and subendothelial deposits of monoclonal IgG. Eight cases of recurrent proliferative glomerulonephritis with monoclonal IgG deposits after a renal transplant have been reported. Almost all of these patients had a certain remission of proteinuria by steroids alone or with cyclophosphamide, and had further remission through other special treatments (ie, rituximab and plasmapheresis). We present a case of recurrent proliferative glomerulonephritis with monoclonal IgG deposits of the IgG3? subtype after a renal transplant, which was insensitive to pulse intravenous methyl-prednisolone and cyclophosphamide remitted by double filtration plasmapheresis. This case report reveals that recurrent proliferative glomerulo-nephritis with monoclonal IgG deposits may be insensitive to intravenous pulse therapy of methylprednisolone and cyclophosphamide. We advocate double filtration plasmapheresis as an effective treatment of proliferative glomerulo-nephritis with monoclonal IgG deposits on remission of proteinuria.

  11. Brain damage complicating septic shock: acute haemorrhagic leucoencephalitis as a complication of the generalised Shwartzman reaction.

    PubMed Central

    Graham, D I; Behan, P O; More, I A

    1979-01-01

    The neuropathological findings in six patients who developed neurological signs after the onset of "septic shock" caused by Gram-negative septicaemia are described. The changes in the brains were characteristic of acute haemorrhagic leucoencephalitis, and there was evidence, particularly in the kidneys, of disseminated intravascular coagulation with tubular necrosis and, in some, appearances indistinguishable from membrano-proliferative glomerulonephritis. It is agreed that acute haemorrhagic leucoencephalitis is another manifestation of a generalised Shwartzman reaction, and it is suggested that activation of complement is the final common pathway that produces tissue damage in the brain and kidney. Images PMID:762582

  12. AGN feedback in the nucleus of M 51

    NASA Astrophysics Data System (ADS)

    Querejeta, M.; Schinnerer, E.; García-Burillo, S.; Bigiel, F.; Blanc, G. A.; Colombo, D.; Hughes, A.; Kreckel, K.; Leroy, A. K.; Meidt, S. E.; Meier, D. S.; Pety, J.; Sliwa, K.

    2016-10-01

    AGN feedback is invoked as one of the most relevant mechanisms that shape the evolution of galaxies. Our goal is to understand the interplay between AGN feedback and the interstellar medium in M 51, a nearby spiral galaxy with a modest AGN and a kpc-scale radio jet expanding through the disc of the galaxy. For this purpose, we combine molecular gas observations in the CO(1-0) and HCN(1-0) lines from the Plateau de Bure interferometer with archival radio, X-ray, and optical data. We show that there is a significant scarcity of CO emission in the ionisation cone, while molecular gas emission tends to accumulate towards the edges of the cone. The distribution and kinematics of CO and HCN line emission reveal AGN feedback effects out to r ~ 500 pc, covering the whole extent of the radio jet, with complex kinematics in the molecular gas which displays strong local variations. We propose that this is the result of the almost coplanar jet pushing on molecular gas in different directions as it expands; the effects are more pronounced in HCN than in CO emission, probably as the result of radiative shocks. Following previous interpretation of the redshifted molecular line in the central 5'' as caused by a molecular outflow, we estimate the outflow rates to be ṀH2 ~ 0.9 M⊙/ yr and Ṁdense ~ 0.6 M⊙/ yr, which are comparable to the molecular inflow rates (~1 M⊙/ yr); gas inflow and AGN feedback could be mutually regulated processes. The agreement with findings in other nearby radio galaxies suggests that this is not an isolated case, and is probably the paradigm of AGN feedback through radio jets, at least for galaxies hosting low-luminosity active nuclei. The reduced HCN(1-0) datacube is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/593/A118

  13. Do some AGN lack X-ray emission?

    NASA Astrophysics Data System (ADS)

    Simmonds, C.; Bauer, F. E.; Thuan, T. X.; Izotov, Y. I.; Stern, D.; Harrison, F. A.

    2016-12-01

    Context. Intermediate-mass black holes (IMBHs) are thought to be the seeds of early supermassive black holes (SMBHs). While ≳100 IMBH and small SMBH candidates have been identified in recent years, few have been robustly confirmed to date, leaving their number density in considerable doubt. Placing firmer constraints both on the methods used to identify and confirm IMBHs/SMBHs, as well as characterizing the range of host environments that IMBHs/SMBHs likely inhabit is therefore of considerable interest and importance. Additionally, finding significant numbers of IMBHs in metal-poor systems would be particularly intriguing, since such systems may represent local analogs of primordial galaxies, and therefore could provide clues of early accretion processes. Aims: Here we study in detail several candidate active galactic nuclei (AGN) found in metal-poor hosts. Methods: We utilize new X-ray and optical observations to characterize these metal-poor AGN candidates and compare them against known AGN luminosity relations and well-characterized IMBH/SMBH samples. Results: Despite having clear broad optical emission lines that are long-lived (≳10-13 yr), these candidate AGN appear to lack associated strong X-ray and hard UV emission, lying at least 1-2 dex off the known AGN correlations. If they are IMBHs/SMBHs, our constraints imply that they either are not actively accreting, their accretion disks are fully obscured along our line-of-sight, or their accretion disks are not producing characteristic high energy emission. Alternatively, if they are not AGN, then their luminous broad emission lines imply production by extreme stellar processes. The latter would have profound implications on the applicability of broad lines for mass estimates of massive black holes. The reduced spectra (FITS files) are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/596/A64

  14. Constraining the properties of AGN host galaxies with spectral energy distribution modelling

    NASA Astrophysics Data System (ADS)

    Ciesla, L.; Charmandaris, V.; Georgakakis, A.; Bernhard, E.; Mitchell, P. D.; Buat, V.; Elbaz, D.; LeFloc'h, E.; Lacey, C. G.; Magdis, G. E.; Xilouris, M.

    2015-04-01

    Detailed studies of the spectral energy distribution (SED) of normal galaxies have increasingly been used to understand the physical mechanism dominating their integrated emission, mainly owing to the availability of high quality multi-wavelength data from the UV to the far-infrared (FIR). However, systems hosting dust-enshrouded nuclear starbursts and/or an accreting supermassive black hole (an active galactic nucleus or AGN) are especially challenging to study. This is due to the complex interplay between the heating by massive stars and the AGN, the absorption and emission of radiation from dust, as well as the presence of the underlying old stellar population. We used the latest release of CIGALE, a fast state-of-the-art galaxy SED-fitting model relying on energy balance, to study the influence of an AGN in a self consistent manner in estimating both the star formation rate (SFR) and stellar mass in galaxies, as well as to calculate the contribution of the AGN to the power output of the host. Using the semi-analytical galaxy formation model galform, we created a suite of mock galaxy SEDs using realistic star formation histories (SFH). We also added an AGN of Type-1, Type-2, or intermediate-type whose contribution to the bolometric luminosity can be variable. We performed an SED-fitting of these catalogues with CIGALE, assuming three different SFHs: a single-exponentially-decreasing (1τ-dec), a double-exponentially-decreasing (2τ-dec), and a delayed SFH. Constraining the overall contribution of an AGN to the total infrared luminosity (fracAGN) is very challenging for fracAGN< 20%, with uncertainties of ~5-30% for higher fractions depending on the AGN type, while FIR and sub-mm are essential. The AGN power has an impact on the estimation of M∗ in Type-1 and intermediate-type AGNs but has no effect on galaxies hosting Type-2 AGNs. We find that in the absence of AGN emission, the best estimates of M∗ are obtained using the 2τ-dec model but at the expense of

  15. Formation of tight junctions between neighboring podocytes is an early ultrastructural feature in experimental crescentic glomerulonephritis

    PubMed Central

    Succar, Lena; Boadle, Ross A; Harris, David C; Rangan, Gopala K

    2016-01-01

    Purpose In crescentic glomerulonephritis (CGN), the development of cellular bridges between podocytes and parietal epithelial cells (PECs) triggers glomerular crescent formation. However, the sequential changes in glomerular ultrastructure in CGN are not well defined. This study investigated the time course of glomerular ultrastructure in experimental CGN. Methods Transmission electron microscopy (TEM) was performed using kidney samples from rats with nephrotoxic serum nephritis (NSN) from day 1 to day 14. Morphometric analysis was conducted on randomly selected glomeruli captured on TEM digital images. Results On day 1 of NSN, there was widespread formation of focal contacts between the cell bodies of neighboring podocytes, and tight junctions were evident at the site of cell-to-cell contact. This was confirmed by the increased expression of the tight junction molecule, zonula occludens-1 (ZO-1), which localized to the points of podocyte cell–cell body contact. On day 2, the interpodocyte distance decreased and the glomerular basement membrane thickness increased. Foot process effacement (FPE) was segmental on day 3 and diffuse by day 5, accompanied by the formation of podocyte cellular bridges with Bowman’s capsule, as confirmed by a decrease in podocyte-to-PEC distance. Fibrinoid necrosis and cellular crescents were evident in all glomeruli by days 7 and 14. In vitro, the exposure of podocytes to macrophage-conditioned media altered cellular morphology and caused an intracellular redistribution of ZO-1. Conclusion The formation of tight junctions between podocytes is an early ultrastructural abnormality in CGN, preceding FPE and podocyte bridge formation and occurring in response to inflammatory injury. Podocyte-to-podocyte tight junction formation may be a compensatory mechanism to maintain the integrity of the glomerular filtration barrier following severe endocapillary injury. PMID:27920570

  16. Post-infectious glomerulonephritis with crescents in adults: a retrospective study

    PubMed Central

    Baikunje, Shashidhar; Vankalakunti, Mahesha; Nikith, A.; Srivatsa, A.; Alva, Suhan; Kamath, Janardhan

    2016-01-01

    Background Crescent formation generally reflects severe glomerular injury. There is sparse literature on post-infectious glomerulonephritis (PIGN) with crescents in adults. This retrospective study looked at nine such cases to see if there is a correlation between the severity of presentation, steroid treatment, histological severity and outcome. Methods Biopsy reports of all the adults who underwent kidney biopsy from February 2010 to June 2014 in a tertiary care hospital were screened and all the cases with the diagnosis of PIGN with crescents were selected. Clinical presentation, laboratory data, histology, treatment and outcome were analysed. Results Six patients had evidence of recent/current infection, but all except two were non-streptococcal. The mean creatinine was 360.67 μmol/L (range 70.72–770.85) and the mean estimated glomerular filtration rate (MDRD eGFR) was 30.28 mL/min/1.73 m2 (range 6.4–111.1) on presentation. All five patients who were treated with steroids had an excellent response. Among the four patients who did not receive steroids, two were left with significant renal impairment (mean MDRD eGFR 23.5 mL/min/1.73 m2) at a mean follow-up of 15.5 months (range 10–21). The mean percentage of glomeruli with crescents was 36.13% (range 11.76–100) and except in one, there was no tubular atrophy or interstitial fibrosis and none had glomerulosclerosis. None of the patients progressed to end-stage renal disease. Conclusion Non-streptococcal infections are more common precipitants. There was no correlation between histological and clinical severity. Patients treated with steroids had better renal outcomes. PMID:26985372

  17. Nitric oxide mediates prolyl hydroxylase 3 expression in mesangial cells and in glomerulonephritis.

    PubMed

    Aglan, Ahmed; Longen, Sebastian; Dehne, Nathalie; Köhler, Yvette; Hassan, Mohamed; Beck, Martina; Tredup, Claudia; Boosen, Meike; Hsieh, Tzung-Harn Louise; Schaefer, Liliana; Beck, Karl-Friedrich; Pfeilschifter, Josef

    2017-03-01

    Renal mesangial cells are regarded as main players in glomerular inflammatory diseases. To investigate a possible crosstalk between inflammatory and hypoxia-driven signaling processes, we stimulated cultured mouse mesangial cells with different inflammatory agents and analyzed the expression of prolyl hydroxylase domain containing proteins (PHDs), the main regulators of hypoxia-inducible factor (HIF) stability. Administration of IL-1β (1 nM) and TNF-α (1 nM), a combination further referred to as cytokine mix (CM), resulted in a fivefold increase in PHD3 but not PHD1 and PHD2 mRNA expression compared to untreated controls. In contrast, a combination of IL-1β, TNF-α with lipopolysaccharide (10 μg/ml), and interferon-γ (20 ng/ml) designated as CM+ showed a high (60-fold) induction of PHD3 and a moderate (twofold) induction of PHD2 mRNA expression. Interestingly, CM+ but not CM induced the expression of inducible NO synthase and endogenously produced NO was responsible for the immense induction of PHD3 in mesangial cells treated with CM+. We found that CM+ affected PHD3 expression mainly via the NO/HIF axis, whereas PHD3 regulation by CM occurred in a NF-κB-dependent manner. In turn, silencing of PHD3 expression resulted in a decrease in the mRNA expression of ICAM-1, MIP-2, MCP-1, and CXCL-10, which are under control of NF-κB. In a rat model of mesangio-proliferative glomerulonephritis, PHD3 mRNA and protein expression was markedly induced and this effect was nearly abolished when rats were treated with the iNOS-specific inhibitor L-NIL, thus confirming our findings also in vivo.

  18. Cocaine/levamisole-induced systemic vasculitis with retiform purpura and pauci-immune glomerulonephritis

    PubMed Central

    Veronese, F.V.; Dode, R.S.O.; Friderichs, M.; Thomé, G.G.; da Silva, D.R.; Schaefer, P.G.; Sebben, V.C.; Nicolella, A.R.; Barros, E.J.G.

    2016-01-01

    Levamisole has been increasingly used as an adulterant of cocaine in recent years, emerging as a public health challenge worldwide. Levamisole-associated toxicity manifests clinically as a systemic vasculitis, consisting of cutaneous, hematological, and renal lesions, among others. Purpura retiform, cutaneous necrosis, intravascular thrombosis, neutropenia, and less commonly crescentic nephritis have been described in association with anti-neutrophil cytoplasmic antibodies (ANCAs) and other autoantibodies. Here we report the case of a 49-year-old male who was a chronic cocaine user, and who presented spontaneous weight loss, arthralgia, and 3 weeks before admission purpuric skin lesions in the earlobes and in the anterior thighs. His laboratory tests on admission showed serum creatinine of 4.56 mg/dL, white blood count 3,800/μL, hemoglobin 7.3 g/dL, urinalysis with 51 white blood cells/μL and 960 red blood cells/μL, and urine protein-to-creatinine ratio 1.20. Serum ANCA testing was positive (>1:320), as well as serum anti-myeloperoxidase and anti-proteinase 3 antibodies. Urine toxicology screen was positive for cocaine and levamisole, with 62.8% of cocaine, 32.2% of levamisole, and 5% of an unidentified substance. Skin and renal biopsies were diagnostic for leukocytoclastic vasculitis and pauci-immune crescentic glomerulonephritis, respectively. The patient showed a good clinical response to cocaine abstinence, and use of corticosteroids and intravenous cyclophosphamide. Last serum creatinine was 1.97 mg/dL, white blood cell count 7,420/μL, and hemoglobin level 10.8 g/dL. In levamisole-induced systemic vasculitis, the early institution of cocaine abstinence, concomitant with the use of immunosuppressive drugs in severe cases, may prevent permanent end organ damage and associate with better clinical outcomes. PMID:27119429

  19. Proliferative glomerulonephritis with monoclonal immunoglobulin G deposits complicated by immunoglobulin A nephropathy in the renal allograft.

    PubMed

    Sawada, Anri; Kawanishi, Kunio; Horita, Shigeru; Koike, Junki; Honda, Kazuho; Ochi, Ayami; Komoda, Mizuki; Tanaka, Yoichiro; Unagami, Kohei; Okumi, Masayoshi; Shimizu, Tomokazu; Ishida, Hideki; Tanabe, Kazunari; Nagashima, Yoji; Nitta, Kosaku

    2016-07-01

    Immunoglobulin (Ig) A nephropathy (IgAN) is a known autoimmune disease due to abnormal glycosylation of IgA1, and occasionally, IgG co-deposition occurs. The prognosis of IgG co-deposition with IgAN is adverse, as shown in the previous studies. However, in the clinical setting, monoclonality of IgG co-deposition with IgAN has not been observed. We describe a case of proliferative glomerulonephritis with monoclonal IgG deposits (PGNMID) combined with IgAN in a renal allograft. A-21-year-old man developed end-stage renal failure with unknown aetiology and underwent living-donor kidney transplantation from his mother 2 years after being diagnosed. One year after kidney transplantation, proteinuria 2+ and haematuria 2+ were detected; allograft biopsy revealed mesangial IgA and C3 deposits, indicating a diagnosis of IgAN. After tonsillectomy and steroid pulse therapy, proteinuria and haematuria resolved. However, 4 years after transplantation, pedal oedema, proteinuria (6.89 g/day) and allograft dysfunction (serum creatinine (sCr) 203.3 µmol/L) appeared. A second allograft biopsy showed mesangial expansion and focal segmental proliferative endocapillary lesions with IgA1λ and monoclonal IgG1κ depositions. Electron microscopic analysis revealed a massive amount of deposits, located in the mesangial and subendothelial lesions. A diagnosis of PGNMID complicated with IgAN was made, and rituximab and plasmapheresis were added to steroid pulse therapy. With this treatment, proteinuria was alleviated to 0.5 g/day, and the allograft dysfunction recovered to sCr 132.6 µmol/L. This case suggests a necessity for investigation of PGNMID and IgA nephropathy in renal allografts to detect monoclonal Ig deposition disease.

  20. Sequential expression of cellular fibronectin by platelets, macrophages, and mesangial cells in proliferative glomerulonephritis.

    PubMed Central

    Barnes, J. L.; Hastings, R. R.; De la Garza, M. A.

    1994-01-01

    Fibronectin (Fn) regulates cell migration, proliferation, and extracellular matrix formation during embryogenesis, angiogenesis, and wound healing. Fn also promotes mesangial cell migration and proliferation in vitro and contributes to extracellular matrix formation and tissue remodeling during glomerular disease. In this study, we examined, by immunohistochemistry and in situ hybridization, the temporal glomerular localization and cellular sources of Fn in Habu snake venom (HSV)-induced proliferative glomerulonephritis. Early HSV-induced glomerular lesions consisted of microaneurysms devoid of resident glomerular cells and filled with platelets, leukocytes, and erythrocytes. Over the course of the disease, mesangial cells migrated into the lesions, proliferated, and formed a confluent cellular mass. Fn was present in lesions beginning at 8 hours, with highest intensity at 72 hours and diminishing at 2 weeks after HSV. Staining for Fn at 8 and 24 hours after HSV was attributed to platelets and macrophages. In situ hybridization and phenotypic identification of cell types within lesions revealed macrophages as the predominant source of cellular Fn mRNA at these times. At 48 hours after HSV, Fn mRNA was expressed in proliferating mesangial cells in addition to macrophages. Most cells in lesions at 72 hours after HSV were mesangial, at a time when expression of Fn mRNA peaked. Cellular expression for Fn mRNA and translated protein declined at 2 weeks after HSV. These studies support the hypothesis that Fn, derived from platelets and macrophages, provides a provisional matrix involved with mesangial cell migration into glomerular lesions. Fn produced by mesangial cells might contribute to the formation of a stable extracellular matrix. Images Figure 1 Figure 3 Figure 4 Figure 5 Figure 6 PMID:8080041

  1. Myeloperoxidase-Specific Plasma Cell Depletion by Bortezomib Protects from Anti-Neutrophil Cytoplasmic Autoantibodies–Induced Glomerulonephritis

    PubMed Central

    Bontscho, Julia; Manz, Rudolf A.; Schneider, Wolfgang; Luft, Friedrich C.; Kettritz, Ralph

    2011-01-01

    Anti-neutrophil cytoplasmic autoantibodies (ANCA) cause vasculitis and necrotizing crescentic glomerulonephritis (NCGN). Steroids and cytotoxic drugs reduce mortality but can cause significant adverse events. The proteasome inhibitor bortezomib (BTZ) prevents glomerulonephritis in mouse models of lupus but its efficacy in ANCA-associated glomerulonephritis is unknown. We induced anti-MPO IgG-mediated NCGN by transplanting wild-type bone marrow (BM) into irradiated MPO-deficient mice immunized with MPO. Four weeks after BM transplantation, we treated mice with steroid/cyclophosphamide (S/CYC) or BTZ. Compared with untreated control mice, both S/CYC and BTZ significantly reduced urine abnormalities, NCGN, and infiltration of neutrophils and macrophages. Response to BTZ depended on timing of administration: BTZ abrogated NCGN if begun 3 weeks, but not 5 weeks, after BM transplantation. BTZ treatment significantly reduced total and MPO-specific plasma cells in both the spleen and bone marrow, resulting in significantly reduced anti-MPO titers. Furthermore, BTZ affected neither B cells nor total CD4 and CD8 T cells, including their naive and effector subsets. In contrast, S/CYC reduced the total number of cells in the spleen, including total and MPO-specific plasma cells and B cells. In contrast to BTZ, S/CYC did not affect total and MPO-specific plasma cells in the bone marrow. Three of 23 BTZ-treated mice died within 36 hours after BTZ administration. In summary, BTZ depletes MPO-specific plasma cells, reduces anti-MPO titers, and prevents NCGN in mice. PMID:21233415

  2. Cholesterol Independent Suppression of Lymphocyte Activation, Autoimmunity and Glomerulonephritis by Apolipoprotein A-I in Normocholesterolemic Lupus-Prone Mice

    PubMed Central

    Black, Leland L.; Srivastava, Roshni; Schoeb, Trenton R.; Moore, Ray D.; Barnes, Stephen; Kabarowski, Janusz H.

    2015-01-01

    Apolipoprotein A-I (ApoA-I), the major lipid-binding protein of high-density lipoprotein (HDL), can prevent autoimmunity and suppress inflammation in hypercholesterolemic mice by attenuating lymphocyte cholesterol accumulation and removing tissue oxidized lipids. However, whether ApoA-I mediates immune suppressive or anti-inflammatory effects in normocholesterolemic conditions and the mechanisms involved remain unresolved. We transferred bone marrow from SLE-prone Sle123 mice into normal, ApoA-I knockout (ApoA-I−/−) and ApoA-I transgenic (ApoA-Itg) mice. Increased ApoA-I in ApoA-Itg mice suppressed CD4+ T and B cell activation without changing lymphocyte cholesterol levels or reducing major ApoA-I-binding oxidized fatty acids. Unexpectedly, oxidized fatty acid peroxisome proliferator-activated receptor gamma (PPARγ) ligands 13-hydroxyoctadecadienoic acid (HODE) and 9-HODE were increased in lymphocytes of autoimmune ApoA-Itg mice. ApoA-I reduced Th1 cells independently of changes in CD4+FoxP3+ regulatory T cells or CD11c+ dendritic cell activation and migration. Follicular helper T cells, germinal center B cells and autoantibodies were also lower in ApoA-Itg mice. Transgenic ApoA-I also improved SLE-mediated glomerulonephritis. However, ApoA-I deficiency did not have opposite effects on autoimmunity or glomerulonephritis, possibly due to compensatory increases of ApoE on HDL. We conclude that although compensatory mechanisms prevent pro-inflammatory effects of ApoA-I deficiency in normocholesterolemic mice, increasing ApoA-I can attenuate lymphocyte activation and autoimmunity in SLE independently of cholesterol transport, possibly through oxidized fatty acid PPARγ ligands, and can reduce renal inflammation in glomerulonephritis. PMID:26466956

  3. [Acute lupus pneumonitis--case report and literature review].

    PubMed

    Starczewska, Małgorzata H; Wawrzyńska, Liliana; Opoka, Lucyna; Małek, Grzegorz; Wieliczko, Monika; Amatuszkiewicz-Rowińska, Joanna; Szturmowicz, Monika

    2013-01-01

    Systemic lupus erythematosus (SLE) is an autoimmune connective tissue disease that is characterized by its chronic course and the involvement of many organs and systems. The most common abnormality in the respiratory system of SLE patients is lupus pleuritis. Less common is parenchymal involvement, which may present as acute lupus pneumonitis (ALP) or chronic interstitial lung disease. Other possible pulmonary manifestations of SLE include pulmonary embolism, diffuse alveolar haemorrhage, acute reversible hypoxaemia, and shrinking lung syndrome. We present the case report of a young woman with previously diagnosed membranous glomerulonephritis with nephrotic syndrome and antiphospholipid syndrome, who was admitted with marked of shortness of breath. The diagnostic process, including imaging studies and laboratory tests, enabled us to confirm a diagnosis of ALP. After initiation of treatment with high doses of methyloprednisolone, nearly complete remission of pulmonary changes was observed. We also perform a literature review regarding acute lupus pneumonitis.

  4. Sustained remission of antineutrophil cytoplasmic antibody-mediated glomerulonephritis and nephrotic syndrome in mixed connective tissue disease.

    PubMed

    Konstantinov, Konstantin N; Harris, Alexis A; Barry, Marc; Murata, Glen H; Tzamaloukas, Antonios H

    2013-08-01

    A woman diagnosed with mixed connective tissue disease (MCTD) developed an anti-myeloperoxidase (MPO) antineutrophil cytoplasmic antibody (ANCA) and nephrotic syndrome with normal serum creatinine. Percutaneous kidney biopsy showed pauci-immune glomerulonephritis with superimposed immune complex deposition. After treatment with cyclophophamide and prednisone, proteinuria decreased progressively to a level of 0.4 g/g creatinine, ANCA became undetectable, while serum creatinine remained normal seven years after the beginning of treatment. Sustained remission of nephrotic proteinuria with preserved renal function may follow treatment of ANCA-mediated disease developing in patients with MCTD.

  5. A case of adult periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) syndrome associated with endocapillary proliferative glomerulonephritis.

    PubMed

    Cazzato, Massimiliano; Neri, Rossella; Possemato, Niccolo; Puccini, Rodolfo; Bombardieri, Stefano

    2013-03-01

    PFAPA is an acronym for periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis. This syndrome has been usually described in pediatric patients and it generally resolves spontaneously. The endocapillary proliferative glomerulonephritis (EPG) is a glomerular injury characterized by hypercellularity in glomerular lumen and is caused by post-infectious or autoimmune diseases. In this paper, we describe the case of a 35-year-old man affected by PFAPA and EPG. To our knowledge this association has never been reported in the literature before.

  6. Increased atherosclerosis and glomerulonephritis in cynomolgus monkeys (Macaca fascicularis) given injections of BSA over an extended period of time.

    PubMed Central

    Stills, H. F.; Bullock, B. C.; Clarkson, T. B.

    1983-01-01

    A study was conducted to compare the effects of experimental immune complex disease on the development of glomerulonephritis and aortic and coronary artery atherosclerosis. Fourteen adult male macaques (Macaca fascicularis) were fed a mildly atherogenic diet. Ten of these animals were given repeated intravenous injections of bovine serum albumin (BSA), and the remaining 4 were given similar injections of saline. Three of the monkeys given BSA responded with a high antibody titer, 4 with a moderate titer, and 3 with a low level titer to BSA. In all 4 monkeys with the moderate antibody response glomerulonephritis developed, characterized by increased glomerular cellularity, electron-dense deposits in the glomerular capillary basal lamina, and deposits of IgG, IgM, C3, C4, and BSA. Glomerulonephritis was not seen in the other 6 monkeys given BSA or the 4 control monkeys. Aortic lesions seen at necropsy consisted of a few fatty intimal streaks with no differences between test monkeys (given BSA) and control monkeys (given saline). There was no correlation between total serum cholesterol concentration, high-density lipoprotein cholesterol concentration, or BSA antibody levels and the degree of aortic atherosclerosis. Immunochemical stains for immunoglobulins and complement components revealed increased intimal staining when intimal thickness increased. Medial staining for immunoglobulin and complement components appeared to be slightly increased in monkeys with moderately high-level titers of BSA. The extent of atherosclerosis in the coronary arteries of monkeys given BSA was greater than in the control animals. Differences in the extent and severity of the atherosclerotic lesions were most pronounced in the proximal portions of the main coronary arteries, suggesting an increased susceptibility of this site to immune-complex-exacerbated atherosclerosis. In addition to the increased lesion severity in monkeys given BSA, there were numerous granulocytes seen within

  7. S100A8/A9 (Calprotectin) Is Critical for Development of Glomerulonephritis and Promotes Inflammatory Leukocyte–Renal Cell Interactions

    PubMed Central

    Pepper, Ruth J.; Wang, Hsu-Han; Rajakaruna, Gayathri K.; Papakrivopoulou, Eugenia; Vogl, Thomas; Pusey, Charles D.; Cook, H. Terence; Salama, Alan D.

    2015-01-01

    Glomerulonephritis is a common cause of end-stage renal disease. Infiltrating leukocytes interacting with renal cells play a critical role during the initiation and progression of glomerulonephritis, but the exact mechanisms are not clearly defined. By using the murine model of nephrotoxic nephritis, we investigated the role of S100A8/A9 [myeloid-related protein (MRP) 8/14, calprotectin] in promoting glomerulonephritis. In nephrotoxic nephritis, wild-type (WT) mice with glomerulonephritis have elevated serum levels of S100A8/A9, whereas mice deficient in MRP14 (S100a9−/−), and hence S100A8/A9, are significantly protected from disease. By using bone marrow transplants, we showed that MRP14 deficiency is required in both the hemopoietic and intrinsic cells for the protective effect. In vitro, both the WT bone marrow–derived macrophages and renal mesangial cells stimulated with S100A8/A9 secrete IL-6, CXCL1, and tumor necrosis factor α; however, Mrp14−/− cells exhibit significantly blunted proinflammatory responses. The interaction of WT bone marrow–derived macrophages with renal microvascular endothelial cells results in increased levels of monocyte chemotactic protein 1, IL-8, and IL-6 cytokines, which is attenuated in Mrp14−/− bone marrow–derived macrophages. Data shows that S100A8/A9 plays a critical role during glomerulonephritis, exerting and amplifying autocrine and paracrine proinflammatory effects on bone marrow–derived macrophages, renal endothelial cells, and mesangial cells. Therefore, complete S100A8/A9 blockade may be a new therapeutic target in glomerulonephritis. PMID:25759267

  8. S100A8/A9 (calprotectin) is critical for development of glomerulonephritis and promotes inflammatory leukocyte-renal cell interactions.

    PubMed

    Pepper, Ruth J; Wang, Hsu-Han; Rajakaruna, Gayathri K; Papakrivopoulou, Eugenia; Vogl, Thomas; Pusey, Charles D; Cook, H Terence; Salama, Alan D

    2015-05-01

    Glomerulonephritis is a common cause of end-stage renal disease. Infiltrating leukocytes interacting with renal cells play a critical role during the initiation and progression of glomerulonephritis, but the exact mechanisms are not clearly defined. By using the murine model of nephrotoxic nephritis, we investigated the role of S100A8/A9 [myeloid-related protein (MRP) 8/14, calprotectin] in promoting glomerulonephritis. In nephrotoxic nephritis, wild-type (WT) mice with glomerulonephritis have elevated serum levels of S100A8/A9, whereas mice deficient in MRP14 (S100a9(-/-)), and hence S100A8/A9, are significantly protected from disease. By using bone marrow transplants, we showed that MRP14 deficiency is required in both the hemopoietic and intrinsic cells for the protective effect. In vitro, both the WT bone marrow-derived macrophages and renal mesangial cells stimulated with S100A8/A9 secrete IL-6, CXCL1, and tumor necrosis factor α; however, Mrp14(-/-) cells exhibit significantly blunted proinflammatory responses. The interaction of WT bone marrow-derived macrophages with renal microvascular endothelial cells results in increased levels of monocyte chemotactic protein 1, IL-8, and IL-6 cytokines, which is attenuated in Mrp14(-/-) bone marrow-derived macrophages. Data shows that S100A8/A9 plays a critical role during glomerulonephritis, exerting and amplifying autocrine and paracrine proinflammatory effects on bone marrow-derived macrophages, renal endothelial cells, and mesangial cells. Therefore, complete S100A8/A9 blockade may be a new therapeutic target in glomerulonephritis.

  9. THE ORIGIN OF DOUBLE-PEAKED NARROW LINES IN ACTIVE GALACTIC NUCLEI. I. VERY LARGE ARRAY DETECTIONS OF DUAL AGNs AND AGN OUTFLOWS

    SciTech Connect

    Müller-Sánchez, F.; Comerford, J. M.; Nevin, R.; Barrows, R. S.; Cooper, M. C.; Greene, J. E.

    2015-11-10

    We have examined a subset of 18 active galactic nuclei (AGNs) drawn from a sample of 81 galaxies that possess double-peaked narrow optical emission line spectra in the Sloan Digital Sky Survey, have 2 optical AGN emission components separated by >0.″2, and are detected in the Faint Images of the Radio Sky at Twenty-centimeters survey. Without follow-up observations, the sources of the double-peaked narrow emission lines are uncertain, and may be produced by kiloparsec-scale separation dual active supermassive black holes, AGN outflows, or disk rotation. In this work, we propose a new methodology to characterize double-peaked narrow emission line galaxies based on optical long-slit spectroscopy and high-resolution multi-band Very Large Array observations. The nature of the radio emission in the sample galaxies is varied. Of the 18 galaxies, we detect 2 compact flat-spectrum radio cores with projected spatial separations on the sky between 0.6 and 1.6 kpc in 3 galaxies: J1023+3243, J1158+3231, and J1623+0808. The two radio sources are spatially coincident with the two optical components of ionized gas with AGN-like line ratios, which confirms the presence of dual AGNs in these three galaxies. Dual AGNs account for only ∼15% (3/18) of the double-peaked AGNs in our sample. Gas kinematics produce ∼75% (13/18) of the double-peaked narrow emission lines, distributed in the following way: seven AGN wind-driven outflows, five radio-jet driven outflows, and one rotating narrow-line region. The remaining 10% (2/18) are ambiguous cases. Our method demonstrates the power of spatially resolved spectroscopy and high-resolution radio observations for the identification of AGN outflows and AGN pairs with angular separations as small as 0.″18.

  10. The first experiment of accretion disc tomography in AGNs

    NASA Astrophysics Data System (ADS)

    Risaliti, Guido

    2011-10-01

    We propose four one-orbit observations of the AGN in NGC~1365, with the main aim of measuring the spectral variations during an eclipse. This source showed extraordinary variability in the past observations, indicating a high probability of catching an eclipse by a Compton-thick cloud in the proposed observation time. The differences in the shape of the iron broad emission line at different phases of the eclipse would be a decisive proof of the relativistic effects on this line due to the strong gravity and fast orbital motion of the inner part of the accretion disc. In addition to this unique experiment, the spectral complexity of NGC~1365 (with the highest S/N detection of iron absorption lines in AGNs) makes it the ideal target for a deep ``legacy'' observation.

  11. NGC 741: Mergers and AGN feedback at the group scale

    NASA Astrophysics Data System (ADS)

    Vrtilek, Jan

    2014-09-01

    While AGN and mergers are thought to play important roles in group and cluster evolution, their effects in galaxy groups are poorly understood. We propose to observe the NGC 741 group, which hosts both an old central radio galaxy, and a spectacular infalling head-tail source. Strongly-bent jets, a 100kpc radio trail and intriguing narrow X-ray filaments suggest that NGC 742 is moving trans-sonically, undergoing stripping and shock heating. NGC 741 possesses both an old, faint radio lobe and an X-ray cavity, whose inflating plasma may have unusual properties. We request Chandra and XMM observations of the group with the goal of examining the roles of the central AGN and infalling galaxy in heating the intra-group medium, and determining the origin of the intriguing X-ray filaments.

  12. Announcment: Conference on Obscured AGN Across Cosmic Time

    NASA Astrophysics Data System (ADS)

    2006-12-01

    Current deep surveys, notably in X-rays and the mid-IR, are making it possible to carry out a census of essentially all the luminous AGN in the Universe. By pene-trating the obscuration that, in Type 2 sources, hides the nuclear regions in the UV to the near-IR spectrum, these new surveys are finding the radio quiet coun-terparts of the powerful radio galaxies.

  13. The international AGN watch: A multiwavelength monitoring consortium

    NASA Technical Reports Server (NTRS)

    Alloin, D.; Clavel, J.; Peterson, B. M.; Reichert, G. A.; Stirpe, G. M.

    1994-01-01

    The International AGN Watch, an informal consortium of over 100 astronomers, was established to coordinate multiwavelength monitoring of a limited number of active galactic nuclei and thus obtain comprehensive continuum and emission-line variability data with unprecedented temporal and wavelength coverage. We summarize the principal scientific results from two completed space-based and ground-based campaigns on the Seyfert galaxies NGC 5548 and NGC 3783. We describe a project in progress and outline our future plans.

  14. The AGN Population and the Cosmic X-ray Background

    NASA Astrophysics Data System (ADS)

    Treister, Ezequiel; Urry, C. Meg; Schawinski, Kevin

    2015-08-01

    In order to fully understand galaxy formation we need to know when in the cosmic history are supermassive black holes (SMBHs) growing more intensively, in what type of galaxies this growth is happening and what fraction of these sources are invisible at most wavelengths due to obscuration. Active Galactic Nuclei (AGN) population synthesis models that can explain the spectral shape and intensity of the cosmic X-ray background (CXRB) indicate that most of the SMBH growth occurs in moderate-luminosity (Lx~1044 erg/s) sources (Seyfert-type AGN), at z~0.5-1 and in heavily obscured but Compton-thin, NH~1023 cm-2, systems.However, this is not the complete history, as a large fraction of black hole growth does not emit significantly in X-rays either due to obscuration, intrinsic low luminosities or large distances. Using a combination of X-ray stacking and multi wavelength selection techniques we constrain the amount of black hole accretion as a function of cosmic history, from z~0 to z~6. The integrated intensity at high energies indicates that a significant fraction of the total black hole growth, 22%, occurs in heavily-obscured systems that are not individually detected in even the deepest X-ray observations.We finally investigate the AGN triggering mechanism as a function of bolometric luminosity, finding evidence for a strong connection between significant black hole growth events and major galaxy mergers from z~0 to z~3, while less spectacular but longer accretion episodes are most likely due to other (stochastic) processes. AGN activity triggered by major galaxies is responsible for ~60% of the total black hole growth.

  15. Triggering star formation by both radiative and mechanical AGN feedback

    NASA Astrophysics Data System (ADS)

    Liu, Chao; Gan, Zhao-Ming; Xie, Fu-Guo

    2013-08-01

    We perform two dimensional hydrodynamic numerical simulations to study the positive active galactic nucleus (AGN) feedback which triggers, rather than suppresses, star formation. Recently, it was shown by Nayakshin et al. and Ishibashi et al. that star formation occurs when the cold interstellar medium (ISM) is squeezed by the impact of mass outflow or radiation pressure, respectively. Mass outflow is ubiquitous in this astrophysical context, and radiation pressure is also important if the AGN is luminous. For the first time in this subject, we incorporate both mass outflow feedback and radiative feedback into our model. Consequently, the ISM is shocked into shells by the AGN feedback, and these shells soon fragment into clumps and filaments because of Rayleigh-Taylor and thermal instabilities. We have two major findings: (1) the star formation rate can indeed be very large in the clumps and filaments. However, the resultant star formation rate density is too large compared with previous works, which is mainly because we ignore the fact that most of the stars that are formed would be disrupted when they move away from the galactic center. (2) Although radiation pressure feedback has a limited effect, when mass outflow feedback is also included, they reinforce each other. Specifically, in the gas-poor case, mass outflow is always the dominant contributor to feedback.

  16. Compton Reflection in AGN with Simbol-X

    NASA Astrophysics Data System (ADS)

    Beckmann, V.; Courvoisier, T. J.-L.; Gehrels, N.; Lubiński, P.; Malzac, J.; Petrucci, P. O.; Shrader, C. R.; Soldi, S.

    2009-05-01

    AGN exhibit complex hard X-ray spectra. Our current understanding is that the emission is dominated by inverse Compton processes which take place in the corona above the accretion disk, and that absorption and reflection in a distant absorber play a major role. These processes can be directly observed through the shape of the continuum, the Compton reflection hump around 30 keV, and the iron fluorescence line at 6.4 keV. We demonstrate the capabilities of Simbol-X to constrain complex models for cases like MCG-05-23-016, NGC 4151, NGC 2110, and NGC 4051 in short (10 ksec) observations. We compare the simulations with recent observations on these sources by INTEGRAL, Swift and Suzaku. Constraining reflection models for AGN with Simbol-X will help us to get a clear view of the processes and geometry near to the central engine in AGN, and will give insight to which sources are responsible for the Cosmic X-ray background at energies >20 keV.

  17. Astrometric Evidence for a Population of Dislodged AGNs

    NASA Astrophysics Data System (ADS)

    Makarov, Valeri V.; Frouard, Julien; Berghea, Ciprian T.; Rest, Armin; Chambers, Kenneth C.; Kaiser, Nicholas; Kudritzki, Rolf-Peter; Magnier, Eugene A.

    2017-02-01

    We investigate a sample of 2293 ICRF2 extragalactic radio-loud sources with accurate positions determined by VLBI, mostly active galactic nuclei (AGNs) and quasars, which are cross-matched with optical sources in the first Gaia release (Gaia DR1). The distribution of offsets between the VLBI sources and their optical counterparts is strongly non-Gaussian, with powerful wings extending beyond 1 arcsec. Limiting our analysis to only high-confidence difference detections, we find (and publish) a list of 188 objects with normalized variances above 12 and offsets below 1 arcsec. Pan-STARRS stacked and monochromatic images resolve some of these sources, indicating the presence of double sources, confusion sources, or pronounced extended structures. Some 89 high-quality objects, however, do not show any perturbations and appear to be star-like single sources, yet they are displaced by multiples of the expected error from the radio-loud AGN. We conclude that a fraction of luminous AGNs (more than 4%) can be physically dislodged from the optical centers of their parent galaxies.

  18. X-Ray Absorption, Nuclear Infrared Emission, and Dust Covering Factors of AGNs: Testing Unification Schemes

    NASA Astrophysics Data System (ADS)

    Mateos, S.; Carrera, F. J.; Alonso-Herrero, A.; Hernán-Caballero, A.; Barcons, X.; Asensio Ramos, A.; Watson, M. G.; Blain, A.; Caccianiga, A.; Ballo, L.; Braito, V.; Ramos Almeida, C.

    2016-03-01

    We present the distributions of the geometrical covering factors of the dusty tori (f2) of active galactic nuclei (AGNs) using an X-ray selected complete sample of 227 AGNs drawn from the Bright Ultra-hard XMM-Newton Survey. The AGNs have z from 0.05 to 1.7, 2-10 keV luminosities between 1042 and 1046 erg s-1, and Compton-thin X-ray absorption. Employing data from UKIDSS, 2MASS, and the Wide-field Infrared Survey Explorer in a previous work, we determined the rest-frame 1-20 μm continuum emission from the torus, which we model here with the clumpy torus models of Nenkova et al. Optically classified type 1 and type 2 AGNs are intrinsically different, with type 2 AGNs having, on average, tori with higher f2 than type 1 AGNs. Nevertheless, ˜20% of type 1 AGNs have tori with large covering factors, while ˜23%-28% of type 2 AGNs have tori with small covering factors. Low f2 are preferred at high AGN luminosities, as postulated by simple receding torus models, although for type 2 AGNs the effect is certainly small. f2 increases with the X-ray column density, which implies that dust extinction and X-ray absorption take place in material that share an overall geometry and most likely belong to the same structure, the putative torus. Based on our results, the viewing angle, AGN luminosity, and also f2 determine the optical appearance of an AGN and control the shape of the rest-frame ˜1-20 μm nuclear continuum emission. Thus, the torus geometrical covering factor is a key ingredient of unification schemes.

  19. X-RAY ABSORPTION, NUCLEAR INFRARED EMISSION, AND DUST COVERING FACTORS OF AGNs: TESTING UNIFICATION SCHEMES

    SciTech Connect

    Mateos, S.; Carrera, F. J.; Alonso-Herrero, A.; Hernán-Caballero, A.; Barcons, X.; Ramos, A. Asensio; Almeida, C. Ramos; Watson, M. G.; Blain, A.; Caccianiga, A.; Ballo, L.; Braito, V.

    2016-03-10

    We present the distributions of the geometrical covering factors of the dusty tori (f{sub 2}) of active galactic nuclei (AGNs) using an X-ray selected complete sample of 227 AGNs drawn from the Bright Ultra-hard XMM-Newton Survey. The AGNs have z from 0.05 to 1.7, 2–10 keV luminosities between 10{sup 42} and 10{sup 46} erg s{sup −1}, and Compton-thin X-ray absorption. Employing data from UKIDSS, 2MASS, and the Wide-field Infrared Survey Explorer in a previous work, we determined the rest-frame 1–20 μm continuum emission from the torus, which we model here with the clumpy torus models of Nenkova et al. Optically classified type 1 and type 2 AGNs are intrinsically different, with type 2 AGNs having, on average, tori with higher f{sub 2} than type 1 AGNs. Nevertheless, ∼20% of type 1 AGNs have tori with large covering factors, while ∼23%–28% of type 2 AGNs have tori with small covering factors. Low f{sub 2} are preferred at high AGN luminosities, as postulated by simple receding torus models, although for type 2 AGNs the effect is certainly small. f{sub 2} increases with the X-ray column density, which implies that dust extinction and X-ray absorption take place in material that share an overall geometry and most likely belong to the same structure, the putative torus. Based on our results, the viewing angle, AGN luminosity, and also f{sub 2} determine the optical appearance of an AGN and control the shape of the rest-frame ∼1–20 μm nuclear continuum emission. Thus, the torus geometrical covering factor is a key ingredient of unification schemes.

  20. VizieR Online Data Catalog: AGN from the RASS (Bade+, 1995)

    NASA Astrophysics Data System (ADS)

    Bade, N.; Fink, H. H.; Engels, D.; Voges, W.; Hagen, H.-J.; Wisotzki, L.; Reimers, D.

    1995-02-01

    This paper presents long slit CCD spectroscopy and X-ray data of 283 AGN detected in the ROSAT-All Sky Survey (RASS). Basis of the sample is the pre-identification of 4651 RASS sources on 134 sky fields (covering in total ~3500sq.deg.). The 283 presented AGN were selected from 1253 AGN candidates resulting from the pre-identification work. (3 data files).

  1. Clustering, Cosmology and a New Era of Black Hole Demographics: The Conditional Luminosity Function of AGNs

    NASA Astrophysics Data System (ADS)

    Ballantyne, David R.

    2016-04-01

    Deep X-ray surveys have provided a comprehensive and largely unbiased view of AGN evolution stretching back to z˜5. However, it has been challenging to use the survey results to connect this evolution to the cosmological environment that AGNs inhabit. Exploring this connection will be crucial to understanding the triggering mechanisms of AGNs and how these processes manifest in observations at all wavelengths. In anticipation of upcoming wide-field X-ray surveys that will allow quantitative analysis of AGN environments, we present a method to observationally constrain the Conditional Luminosity Function (CLF) of AGNs at a specific z. Once measured, the CLF allows the calculation of the AGN bias, mean dark matter halo mass, AGN lifetime, halo occupation number, and AGN correlation function - all as a function of luminosity. The CLF can be constrained using a measurement of the X-ray luminosity function and the correlation length at different luminosities. The method is demonstrated at z ≈0 and 0.9, and clear luminosity dependence in the AGN bias and mean halo mass is predicted at both z. The results support the idea that there are at least two different modes of AGN triggering: one, at high luminosity, that only occurs in high mass, highly biased haloes, and one that can occur over a wide range of halo masses and leads to luminosities that are correlated with halo mass. This latter mode dominates at z<0.9. The CLFs for Type 2 and Type 1 AGNs are also constrained at z ≈0, and we find evidence that unobscured quasars are more likely to be found in higher mass halos than obscured quasars. Thus, the AGN unification model seems to fail at quasar luminosities.

  2. VizieR Online Data Catalog: Gamma-ray AGN type determination (Hassan+, 2013)

    NASA Astrophysics Data System (ADS)

    Hassan, T.; Mirabal, N.; Contreras, J. L.; Oya, I.

    2013-11-01

    In this paper, we employ Support Vector Machines (SVMs) and Random Forest (RF) that embody two of the most robust supervised learning algorithms available today. We are interested in building classifiers that can distinguish between two AGN classes: BL Lacs and FSRQs. In the 2FGL, there is a total set of 1074 identified/associated AGN objects with the following labels: 'bzb' (BL Lacs), 'bzq' (FSRQs), 'agn' (other non-blazar AGN) and 'agu' (active galaxies of uncertain type). From this global set, we group the identified/associated blazars ('bzb' and 'bzq' labels) as the training/testing set of our algorithms. (2 data files).

  3. The sharpest view of the local AGN population at mid-infrared wavelengths

    NASA Astrophysics Data System (ADS)

    Asmus, Daniel; Hönig, Sebastian F.; Gandhi, Poshak; Smette, Alain; Duschl, Wolfgang J.

    2014-07-01

    We present the largest mid-infrared (MIR) atlas of active galactic nuclei at sub-arcsec spatial scales containing 253 objects with a median redshift of 0.016. It comprises all available ground-based high-angular resolution MIR observations performed to date with 8-meter class telescopes and includes 895 photometric measurements. All types of AGN are present in the atlas, which also includes 80 per cent of the 9-month BAT AGN sample. Therefore, this atlas and its subsamples are very well-suited for AGN unification studies. A first application of the atlas is the extension of the MIR-X-ray luminosity correlation for AGN.

  4. Investigating the host galaxies of luminous AGN in the local universe with integral field spectroscopy

    NASA Astrophysics Data System (ADS)

    McElroy, Rebecca; Croom, Scott; Husemann, Bernd; Close AGN Reference Survey; SAMI Galaxy Survey

    2017-01-01

    This thesis investigates how galaxies and their super massive black holes coevolve. We use integral field spectroscopy to search for evidence of AGN feedback and triggering. We demonstrate that outflows are ubiquitous among luminous local type 2 AGN using observations from the AAT's SPIRAL instrument. Using multiple component Gaussian emission line decomposition we are able to disentangle the kinematic and ionisation properties of these winds. This allows us to argue that the outflows from these AGN are directly impacting the surrounding ISM within the galaxies. We search for evidence of AGN triggering using data from The Close AGN Reference Survey (CARS). CARS aims to provide a detailed multi-wavelength view of 40 nearby (0.01 < z < 0.06) unobscured AGN to study the link between AGN and their host galaxies. The primary CARS observations come from the MUSE integral field unit on the VLT, and complementary multi-wavelength observations have been approved from SOFIA, Chandra, VLA, HST, and others. We compare the stellar kinematics of active galaxies from CARS to similar inactive galaxies. We then use kinemetry to estimate the degree of dynamical disturbance, to determine whether active nuclei are preferentially hosted in dynamically disturbed or merging systems. Finally, we highlight the discovery of an AGN that has changed spectral type not once, but twice. So called ‘changing look’ AGN are an uncommon phenomenon, but twice changed AGN are much rarer. This AGN first transitioned from a narrow line AGN (type 2) to a broad line AGN (type 1) in the 1980s. It was recently observed as part of CARS. Examination of the MUSE data for this particular source showed that it no longer had the spectral features typical of a type 1 AGN. The continuum emission from the accretion disk was no longer visible and the broad lines were dramatically diminished. In this talk we describe the possible reasons for this change, supported by analysis of multi-epoch optical photometry and

  5. Three years of Swift/BAT Survey of AGN: Reconciling Theory and Observations?

    SciTech Connect

    Burlon, D.; Ajello, M.; Greiner, J.; Comastri, A.; Merloni, A.; Gehrels, N.; /NASA, Goddard

    2011-02-07

    It is well accepted that unabsorbed as well as absorbed AGN are needed to explain the nature and the shape of the Cosmic X-ray background, even if the fraction of highly absorbed objects (dubbed Compton-thick sources) substantially still escapes detection. We derive and analyze the absorption distribution using a complete sample of AGN detected by Swift-BAT in the first three years of the survey. The fraction of Compton-thick AGN represents only 4.6% of the total AGN population detected by Swift-BAT. However, we show that once corrected for the bias against the detection of very absorbed sources the real intrinsic fraction of Compton-thick AGN is 20{sub -6}{sup +9}%. We proved for the first time (also in the BAT band) that the anti-correlation of the fraction of absorbed AGN and luminosity it tightly connected to the different behavior of the luminosity functions (XLFs) of absorbed and unabsorbed AGN. This points towards a difference between the two subsamples of objects with absorbed AGN being, on average, intrinsically less luminous than unobscured ones. Moreover the XLFs show that the fraction of obscured AGN might also decrease at very low luminosity. This can be successfully interpreted in the framework of a disk cloud outflow scenario as the disappearance of the obscuring region below a critical luminosity. Our results are discussed in the framework of population synthesis models and the origin of the Cosmic X-ray Background.

  6. Photometric AGN reverberation mapping - an efficient tool for BLR sizes, black hole masses, and host-subtracted AGN luminosities

    NASA Astrophysics Data System (ADS)

    Haas, M.; Chini, R.; Ramolla, M.; Pozo Nuñez, F.; Westhues, C.; Watermann, R.; Hoffmeister, V.; Murphy, M.

    2011-11-01

    Photometric reverberation mapping employs a wide band pass to measure the AGN continuum variations and a suitable narrow band to trace the echo of an emission line in the broad line region (BLR). The narrow band catches both the emission line and the underlying continuum, and one needs to extract the pure emission line light curve. We performed a test on two local AGNs, PG0003+199 and Ark120, by observing well-sampled broad- (B, V) and narrow-band light curves with the robotic 15 cm telescope VYSOS-6 on Cerro Armazones, Chile. We find that, as long as the emission line contributes 50% to the band pass, the pure emission line light curve can be reconstructed from photometric monitoring data so that the time lag τ can be measured. For both objects the lags are consistent with spectroscopic reverberation results. We calculated virial black hole masses in agreement with literature values, by combining the BLR size RBLR (τ) from photometric monitoring with the velocity dispersion of a single contemporaneous spectrum. Applying the flux variation gradient method, we estimate the host galaxy contribution in the apertures used and the host-subtracted restframe 5100 Å luminosity LAGN. Our LAGN differs significantly from previous estimates, placing both sources ~50% closer to the RBLR - LAGN relation. This suggests that the scatter in the current RBLR - LAGN relation is largely caused by uncertainties in RBLR due to undersampled light curves and by uncertainties in the host-subtracted AGN luminosities inferred so far. If the scatter can be reduced, then two quasar samples matching in RBLR should also match in intrinsic LAGN, independent of redshift, thus offering the prospect of probing cosmological models. Photometric reverberation mapping opens the door to efficiently measuring hundreds of BLR sizes and host-subtracted AGN luminosities even with small telescopes, but also routinely with upcoming large survey telescopes like the LSST.

  7. Epidemiology of Histologically Proven Glomerulonephritis in Africa: A Systematic Review and Meta-Analysis

    PubMed Central

    Okpechi, Ikechi G.; Ameh, Oluwatoyin I.; Bello, Aminu K.; Ronco, Pierre; Swanepoel, Charles R.; Kengne, Andre P.

    2016-01-01

    Background and aim Glomerulonephritis (GN) is a leading cause of end-stage renal disease (ESRD) in Africa. Data on epidemiology and outcomes of glomerular diseases from Africa is still limited. We conducted a systematic review on the epidemiology of histologically proven glomerular diseases in Africa between 1980 and 2014. Materials and methods We searched literature using PubMed, AfricaWide, the Cumulative Index to Nursing and Allied Health Literature on EBSCO Host, Scopus, African Journals online databases, and the African Index Medicus, for relevant studies. The review was conducted using standard methods and frameworks using only biopsy-confirmed data. Results Twenty four (24) studies comprising 12,093 reported biopsies from 13 countries were included in this analysis. The median number of biopsies per study was 127.0 (50–4436), most of the studies (70.0%) originated from North Africa and the number of performed kidney biopsies varied from 5.2 to 617 biopsies/year. Nephrotic syndrome was the commonest indication of renal biopsy. The frequency of reported primary pathologic patterns included, minimal change disease (MCD); 16.5% (95%CI: 11.2–22.6), focal segmental glomerulosclerosis (FSGS); 15.9% (11.3–21.1), mesangiocapillary GN (MCGN); 11.8% (9.2–14.6), crescentic GN; 2.0% (0.9–3.5) and IgA nephropathy 2.8% (1.3–4.9). Glomerular diseases related to hepatitis B and systemic lupus erythematosus had the highest prevalence among assessed secondary diseases: 8.4% (2.0–18.4) and 7.7% (4.5–11.7) respectively. There was no evidence of publication bias and regional differences were seen mostly for secondary GNs. Conclusions Glomerular diseases remain poorly characterized in sub-Saharan Africa due to declining renal biopsy rates and consequent paucity of data on pathologic patterns of key renal diseases. Development of renal biopsy registries in Africa is likely to enable adequate characterization of the prevalence and patterns of glomerular diseases

  8. [A case of rapidly progressive glomerulonephritis in the course of Wegener's granulomatosis].

    PubMed

    Idasiak-Piechocka, I; Oko, A; Łochyńska, K; Woźniak, A; Czekalski, S

    2000-01-01

    Wegener's granulomatosis (WG) is characterized by granulomatous vasculitis of the respiratory tract and glomerulonephritis (GN). Prognosis of this disease is poor and about 20% of untreated patients die after one year from the onset. WG was recognized in 45-year-old patient on the basis of: 1) clinical symptoms (joint pain and swollen, purpura on the skin which appeared one week after respiratory tract infection, ulceration of the tonsils and lingula), 2) results of additional testing (X-chest-ray-infiltrates of both lungs), positive results of the cANCA (titre 1:640) and rapidly progressive renal failure [the increase of serum creatinine level (Pcr) from 123.7 to 707 mumol/l (1.4 to 8.0 mg/dl) during one week]. Renal biopsy revealed extracapillary GN (cellular crescents in 7 out of 8 glomeruli and scattered foci of fibrinoid necrosis of capillary walls in all). At the beginning of the treatment Pcr raised to 884 mumol/l (10 mg/dl) and the patient required hemodialysis. He was treated with methylprednisolone (M) at flash doses of 1000 mg/24 h by three days followed by 125 mg/24 h i.v.--because of peptic ulcer, with cyclophosphamide (C-150 mg/24 h p.p.), with trimetoprim/sulphametoxazole, with pentoxifylline and omeprazol. After six weeks of the treatment in the control kidney biopsy sclerotic changes in 10 out of 13 glomeruli and diffuse interstitial fibrosis were found. However, during the same time, we observed clinical remission of the disease and the decrease of Pcr to 176.8 mumol/l (2 mg/dl). The M dosis was reduced by 5 mg every weeks and the C dosis--to 50 mg (because of the increase of aminotransferase levels) After six months of the treatment Pcr was 132.6 mumol/l (1.5 mg/dl) and CANCA titer was 1:16. In this case of RPGN, despite off the progression of the morphological changes in the kidney, we obtained the clinical remission of the disease and significant decrease of Pcr level. These results suggest that aggressive treatment of WG is justified even in

  9. Interleukin-1 receptor antagonist ameliorates experimental anti-glomerular basement membrane antibody-associated glomerulonephritis.

    PubMed Central

    Tang, W W; Feng, L; Vannice, J L; Wilson, C B

    1994-01-01

    The contribution of IL-1 to leukocyte infiltration in anti-glomerular basement membrane (GBM) antibody (Ab) glomerulonephritis (GN) was examined by the administration of a specific IL-1 receptor antagonist (IL-1ra). Lewis rats received anti-GBM Ab or normal rabbit serum and were treated with either 0.9% saline or 6 mg IL-1ra over a 24-h time period. Plasma IL-1ra concentration was 2,659 +/- 51 ng/ml 4 h after anti-GBM Ab and IL-1ra administration. PMN and monocyte/macrophage infiltration declined 39% (9.8 +/- 1.9 to 6.0 +/- 1.5 PMN/glomerulus, P < 0.001) and 29% (4.9 +/- 0.8 to 3.5 +/- 0.8 ED-1 cells/glomerulus, P = 0.002) with IL-1ra treatment at 4 h, respectively. Similarly, the number of glomerular cells staining for lymphocyte function-associated molecule-1 beta (CD18) declined 39% from 16.7 +/- 1.9 to 10.7 +/- 1.6 cells/glomerulus at 4 h (P = 0.0001). This was associated with a decrease in glomerular intracellular adhesion molecule-1 expression. The mean glomerular intracellular adhesion molecule-1 score in anti-GBM Ab GN rats treated with IL-1ra was less than that of rats administered anti-GBM Ab and 0.9% saline at 4 (2.0 +/- 0.2 vs 2.5 +/- 0.2, P < 0.05) and 24 (2.5 +/- 0.1 vs 3.1 +/- 0.2, P = 0.0001) h. These immunopathologic changes correlated with a 50% reduction in proteinuria from 147 +/- 34 to 75 +/- 25 mg/d (P < 0.002). Treatment with IL-1ra did not affect the steady state mRNA expression of either IL-1 beta or TNF alpha. An increase in the IL-1ra dose to 30 mg given within the initial 4 h provided no additional benefit. The decline in PMN and monocyte/macrophage infiltration of the glomerulus at 4 h was similar to that found in the initial study. Furthermore, the protective benefit of IL-1ra was abrogated by doubling the dose of the anti-GBM Ab GN, despite administering high dose IL-1ra (30 mg). In these studies, detectable IL-1ra was found in the serum of untreated anti-GBM Ab GN controls. These data suggest a positive yet limited role for IL-1ra in

  10. Correlation among WHO classes, histomorphologic patterns of glomerulonephritis and glomerular immune deposits in SLE.

    PubMed

    Ferluga, D; Jerse, M; Vizjak, A; Hvala, A; Rozman, B; Kos-Golja, M; Bren, A F

    2000-08-25

    In addition to the conventional World Health Organization (WHO) classification of lupus glomerulonephritis (GN), various concomitant approaches have been introduced in the evaluation of renal biopsies of patients with systemic lupus erythematosus (SLE) in order to increase the impact of biopsies on the decision concerning the most appropriate therapy as well as for establishing the prognosis. Three hundred and seventy kidney tissue samples from 267 SLE patients were analysed using standardised light, electron and immunofluorescence microscopic techniques. In 155 patients, a comparative clinical follow-up study and statistical analysis were performed. The study highlighted the heterogeneity of WHO classes IV and III, which include 5 and 6 different conventional histomorphologic types of GN, respectively. Mixed membranous and proliferative GN associated with "full-house" mesangial-transmembranous immune deposits, demonstrated in more than one third of our SLE cases, appears to be diagnostically most characteristic. Immune deposits distributed in the glomeruli in five different patterns, obviously play a major role in the pathogenesis of various WHO classes and histomorphologic types of lupus GN. Additional mechanisms related to the occurrence of antiphospholipid antibodies and antineutrophil cytoplasmic antibodies are suggested to contribute to the histomorphologic heterogeneity of WHO class III and IV lupus GN, particularly to the development of thrombotic, necrotising and crescentic glomerular lesions. In the present study, a statistically significant association was demonstrated between increasing mean values of the activity index and glomerular deposit distribution patterns labeled by subendothelial deposits. Furthermore, a significant correlation was established between an increasing risk of developing renal failure and increasing mean values of the chronicity index. Differences in the increasing risk of developing renal failure between groups with different

  11. Mesangial proliferative glomerulonephritis associated with progressive amyloid deposition in hamsters experimentally infected with Leishmania donovani.

    PubMed Central

    Oliveira, A. V.; Roque-Barreira, M. C.; Sartori, A.; Campos-Neto, A.; Rossi, M. A.

    1985-01-01

    likely that they are implicated in the pathogenesis of the mesangial proliferative glomerulonephritis in hamsters experimentally infected with L donovani. The glomerular changes may also explain the loss of immunoglobulins in the urine and the consequent lowering of serum immunoglobulin levels. Images Figure 2 Figure 3 Figure 4 PMID:4025511

  12. Clustering, Cosmology and a New Era of Black Hole Demographics: The Conditional Luminosity Function of AGNs

    NASA Astrophysics Data System (ADS)

    Ballantyne, David R.

    2017-01-01

    Deep X-ray surveys have provided a comprehensive and largely unbiased view of active galactic nuclei (AGN) evolution stretching back to z~5. However, it has been challenging to use the survey results to connect this evolution to the cosmological environment that AGNs inhabit. Exploring this connection will be crucial to understanding the triggering mechanisms of AGNs and how these processes manifest in observations at all wavelengths. In anticipation of upcoming wide-field X-ray surveys that will allow quantitative analysis of AGN environments, we present a method to observationally constrain the Conditional Luminosity Function (CLF) of AGNs at a specific z. Once measured, the CLF allows the calculation of the AGN bias, mean dark matter halo mass, AGN lifetime, halo occupation number, and AGN correlation function -- all as a function of luminosity. The CLF can be constrained using a measurement of the X-ray luminosity function and the correlation length at different luminosities. The method is illustrated at z≈0 and 0.9 using the limited data that is currently available, and a clear luminosity dependence in the AGN bias and mean halo mass is predicted at both, supporting the idea that there are at least two different modes of AGN triggering. In addition, the CLF predicts that z≈0.9 quasars may be commonly hosted by haloes with Mh ~ 1014 M⊙. These `young cluster' environments may provide the necessary interactions between gas-rich galaxies to fuel luminous accretion. The results derived from this method will be useful to populate AGNs of different luminosities in cosmological simulations.

  13. AGN are cooler than you think: the intrinsic far-IR emission from QSOs

    NASA Astrophysics Data System (ADS)

    Symeonidis, M.; Giblin, B. M.; Page, M. J.; Pearson, C.; Bendo, G.; Seymour, N.; Oliver, S. J.

    2016-06-01

    We present an intrinsic AGN spectral energy distribution (SED) extending from the optical to the submm, derived with a sample of unobscured, optically luminous (νLν,5100 > 1043.5 erg s-1) QSOs at z < 0.18 from the Palomar Green survey. The intrinsic AGN SED was computed by removing the contribution from stars using the 11.3 μm polycyclic aromatic hydrocarbon (PAH) feature in the QSOs' mid-IR spectra; the 1σ uncertainty on the SED ranges between 12 and 45 per cent as a function of wavelength and is a combination of PAH flux measurement errors and the uncertainties related to the conversion between PAH luminosity and star-forming luminosity. Longwards of 20 μm, the shape of the intrinsic AGN SED is independent of the AGN power indicating that our template should be applicable to all systems hosting luminous AGN (νLν, 5100 or L_X(2-10 keV) ≳ 1043.5 erg s-1). We note that for our sample of luminous QSOs, the average AGN emission is at least as high as, and mostly higher than, the total stellar powered emission at all wavelengths from the optical to the submm. This implies that in many galaxies hosting powerful AGN, there is no `safe' broad-band photometric observation (at λ < 1000 μm) which can be used in calculating star formation rates without subtracting the AGN contribution. Roughly, the AGN contribution may be ignored only if the intrinsic AGN luminosity at 5100 AA is at least a factor of 4 smaller than the total infrared luminosity (LIR, 8-1000 μm) of the galaxy. Finally, we examine the implication of our work in statistical studies of star formation in AGN host galaxies.

  14. Incidence of WISE -selected obscured AGNs in major mergers and interactions from the SDSS

    NASA Astrophysics Data System (ADS)

    Weston, Madalyn E.; McIntosh, Daniel H.; Brodwin, Mark; Mann, Justin; Cooper, Andrew; McConnell, Adam; Nielsen, Jennifer L.

    2017-02-01

    We use the Wide-field Infrared Survey Explorer (WISE) and the Sloan Digital Sky Survey (SDSS) to confirm a connection between dust-obscured active galactic nuclei (AGNs) and galaxy merging. Using a new, volume-limited (z ≤ 0.08) catalogue of visually selected major mergers and galaxy-galaxy interactions from the SDSS, with stellar masses above 2 × 1010 M⊙, we find that major mergers (interactions) are 5-17 (3-5) times more likely to have red [3.4] - [4.6] colours associated with dust-obscured or `dusty' AGNs, compared to non-merging galaxies with similar masses. Using published fibre spectral diagnostics, we map the [3.4] - [4.6] versus [4.6] - [12] colours of different emission-line galaxies and find that one-quarter of Seyferts have colours indicative of a dusty AGN. We find that AGNs are five times more likely to be obscured when hosted by a merging galaxy, half of AGNs hosted by a merger are dusty, and we find no enhanced frequency of optical AGNs in merging over non-merging galaxies. We conclude that undetected AGNs missed at shorter wavelengths are at the heart of the ongoing AGN-merger connection debate. The vast majority of mergers hosting dusty AGNs are star forming and located at the centres of Mhalo < 1013 M⊙ groups. Assuming plausibly short-duration dusty-AGN phases, we speculate that a large fraction of gas-rich mergers experience a brief obscured AGN phase, in agreement with the strong connection between central star formation and black hole growth seen in merger simulations.

  15. On the relation between X-ray absorption and optical extinction in AGN

    NASA Astrophysics Data System (ADS)

    Ordovás-Pascual, I.; Mateos, S.; Carrera, F. J.; Wiersema, K.; Caccianiga, A.; Della Ceca, R.; Severgnini, P.; Moretti, A.; Ballo, L.

    2017-03-01

    According to the Unified Model of Active Galactic Nuclei (AGN), an X-ray unabsorbed AGN should appear as unobscured in the optical band (the so called type-1 AGN). However, there is an important fraction (10–30%) of AGN whose optical and X-ray classifications do not match. To provide insight into the origin of such apparent discrepancies, we have conducted two types of analysis: 1) a detailed study of the UV-to-near-IR emission of two X-ray low absorbed AGN with high optical extinction drawn from the Bright Ultra-Hard XMM-Newton Survey (BUXS); 2) a statistical analysis of the optical obscuration and X-ray absorption properties of 159 type-1 AGN drawn from BUXS to determine the distribution of dust-to-gas ratios in AGN over a broad range of luminosities and redshifts. We have determined the impact of contamination from the AGN hosts in their optical classification (detection or lack of detection of rest-frame UV-optical broad emission lines). This is an on-going project, but our preliminary results, reported below, are very promising.

  16. Hard X-ray Spectroscopy of Obscured AGN with NuSTAR

    NASA Astrophysics Data System (ADS)

    Balokovic, Mislav; Harrison, Fiona; NuSTAR Extragalactic Surveys Team

    2017-01-01

    The Nuclear Spectroscopic Telescope Array (NuSTAR) has enabled studies of the local active galactic nuclei (AGN) to extend into the hard X-ray band, up to 79 keV, with unprecedented spatial resolution and sensitivity. As a part of its extragalactic program, NuSTAR is surveying the nearby population of AGN detected at hard X-ray energies by the Swift Burst Alert Telescope (Swift/BAT), selecting even the most obscured local AGN. I will highlight some of the results based on broadband X-ray spectroscopy of individual targets and present my work on the large representative sample of more than a hundred nearby obscured AGN, which constitutes the largest available atlas of hard X-ray spectra of obscured AGN to date. The high quality of the data allows us to probe the details of AGN structures such as the X-ray-emitting corona and the toroidal obscurer in the under-explored spectral window above 10 keV. I will present both phenomenological results important for synthesis models of the cosmic X-ray background, and a novel approach for constraining the geometry of the gas surrounding the supermassive black hole (including the accretion disk, the broad-line region, and the torus) from the hard X-ray band. Finally, I will discuss how what we learned from this survey of local AGN relates to deeper high-redshift X-ray surveys and AGN structure probes at other wavelengths.

  17. Unravelling the Complex Structure of AGN-driven Outflows. II. Photoionization and Energetics

    NASA Astrophysics Data System (ADS)

    Karouzos, Marios; Woo, Jong-Hak; Bae, Hyun-Jin

    2016-12-01

    Outflows have been shown to be prevalent in galaxies hosting luminous active galactic nuclei (AGNs); they present a physically plausible way to couple the AGN energy output with the interstellar medium of their hosts. Despite their prevalence, accurate characterization of these outflows has been challenging. In the second of a series of papers, we use Gemini Multi-Object Spectrograph integral field unit (IFU) data of six local (z < 0.1) and moderate-luminosity Type 2 AGNs to study the ionization properties and energetics of AGN-driven outflows. We find strong evidence connecting the extreme kinematics of the ionized gas to the AGN photoionization. The kinematic component related to the AGN-driven outflow is clearly separated from other kinematic components, such as virial motions or rotation, on the velocity and velocity dispersion diagram. Our spatially resolved kinematic analysis reveals that 30 to 90% of the total mass and kinetic energy of the outflow is contained within the central kpc of the galaxy. The spatially integrated mass and kinetic energy of the gas entrained in the outflow correlate well with the AGN bolometric luminosity and results in energy conversion efficiencies between 0.01% and 1%. Intriguingly, we detect ubiquitous signs of ongoing circumnuclear star formation. Their small size, the centrally contained mass and energy, and the universally detected circumnuclear star formation cast doubts on the potency of these AGN-driven outflows as agents of galaxy-scale negative feedback.

  18. Submillimetre observations of WISE-selected high-redshift, luminous AGN and their surrounding overdense environments

    NASA Astrophysics Data System (ADS)

    Jones, Suzy F.

    2016-08-01

    We present JCMT SCUBA-2 850 μm submillimetre (submm) observations of 10 mid-infrared (mid-IR) luminous active galactic nuclei (AGNs), detected by the Wide-field Infrared Survey Explorer (WISE) all-sky IR survey and 30 that have also been detected by the NVSS/FIRST radio survey. These rare sources are selected by their extremely red mid-IR spectral energy distributions (SEDs). Further investigations show that they are highly obscured, have abundant warm AGN-heated dust and are thought to be experiencing intense AGN feedback. When comparing the number of submm galaxies detected serendipitously in the surrounding 1.5 arcmin to those in blank-field submm surveys, there is a very significant overdensity, of order 3-5, but no sign of radial clustering centred at our primary objects. The WISE-selected AGN thus reside in 10-Mpc-scale overdense environments that could be forming in pre-viralized clusters of galaxies. WISE-selected AGNs appear to be the strongest signposts of high-density regions of active, luminous and dusty galaxies. SCUBA-2 850 μm observations indicate that their submm fluxes are low compared to many popular AGN SED templates, hence the WISE/radio-selected AGNs have either less cold and/or more warm dust emission than normally assumed for typical AGN. Most of the targets have total IR luminosities ≥1013 L⊙, with known redshifts of 20 targets between z ˜ 0.44-4.6.

  19. A Search for AGN Intra-Day Variability with KVN

    NASA Astrophysics Data System (ADS)

    Lee, Taeseok; Trippe, Sascha; Oh, Junghwan; Byun, Do-Young; Sohn, Bong-Won; Lee, Sang-Sung

    2015-10-01

    Active galactic nuclei (AGN) are known for irregular variability on all time scales, down to intra-day variability with relative variations of a few percent within minutes to hours. On such short timescales, unexplored territory, such as the possible existence of a shortest characteristic time scale of activity and the shape of the high frequency end of AGN power spectra, still exists. We present the results of AGN single-dish fast photometry performed with the Korean VLBI Network (KVN). Observations were done in a "anti-correlated" mode using two antennas, with always at least one antenna pointing at the target. This results in an effective time resolution of less than three minutes. We used all four KVN frequencies, 22, 43, 86, and 129 GHz, in order to trace spectral variability, if any. We were able to derive high-quality light curves for 3C 111, 3C 454.3, and BL Lacertae at 22 and 43 GHz, and for 3C 279 at 86 GHz, between May 2012 and April 2013. We performed a detailed statistical analysis in order to assess the levels of variability and the corresponding upper limits. We found upper limits on flux variability ranging from ∼1.6% to ∼7.6%. The upper limits on the derived brightness temperatures exceed the inverse Compton limit by three to six orders of magnitude. From our results, plus comparison with data obtained by the University of Michigan Radio Astronomy Observatory, we conclude that we have not detected source-intrinsic variability which would have to occur at sub-per cent levels.

  20. Relativistic HD and MHD modelling for AGN jets

    NASA Astrophysics Data System (ADS)

    Keppens, R.; Porth, O.; Monceau-Baroux, R.; Walg, S.

    2013-12-01

    Relativistic hydro and magnetohydrodynamics (MHD) provide a continuum fluid description for plasma dynamics characterized by shock-dominated flows approaching the speed of light. Significant progress in its numerical modelling emerged in the last two decades; we highlight selected examples of modern grid-adaptive, massively parallel simulations realized by our open-source software MPI-AMRVAC (Keppens et al 2012 J. Comput. Phys. 231 718). Hydrodynamical models quantify how energy transfer from active galactic nuclei (AGN) jets to their surrounding interstellar/intergalactic medium (ISM/IGM) gets mediated through shocks and various fluid instability mechanisms (Monceau-Baroux et al 2012 Astron. Astrophys. 545 A62). With jet parameters representative for Fanaroff-Riley type-II jets with finite opening angles, we can quantify the ISM volumes affected by jet injection and distinguish the roles of mixing versus shock-heating in cocoon regions. This provides insight in energy feedback by AGN jets, usually incorporated parametrically in cosmological evolution scenarios. We discuss recent axisymmetric studies up to full 3D simulations for precessing relativistic jets, where synthetic radio maps can confront observations. While relativistic hydrodynamic models allow one to better constrain dynamical parameters like the Lorentz factor and density contrast between jets and their surroundings, the role of magnetic fields in AGN jet dynamics and propagation characteristics needs full relativistic MHD treatments. Then, we can demonstrate the collimating properties of an overal helical magnetic field backbone and study differences between poloidal versus toroidal field dominated scenarios (Keppens et al 2008 Astron. Astrophys. 486 663). Full 3D simulations allow one to consider the fate of non-axisymmetric perturbations on relativistic jet propagation from rotating magnetospheres (Porth 2013 Mon. Not. R. Astron. Soc. 429 2482). Self-stabilization mechanisms related to the detailed

  1. The view of AGN-host alignment via reflection spectroscopy

    NASA Astrophysics Data System (ADS)

    Middleton, Matthew J.; Parker, Michael L.; Reynolds, Christopher S.; Fabian, Andrew C.; Lohfink, Anne M.

    2016-04-01

    The fuelling of active galactic nuclei (AGN) - via material propagated through the galactic disc or via minor mergers - is expected to leave an imprint on the alignment of the sub-pc disc relative to the host galaxy's stellar disc. Determining the inclination of the inner disc usually relies on the launching angle of the jet; here instead we use the inclination derived from reflection fits to a sample of AGN. We determine the distorting effect of unmodelled Fe XXV/XXVI features and, via extensive simulations, determine the difference in disc inclination resulting from the use of RELXILL compared to REFLIONX. We compare inner disc inclinations to those for the host galaxy stellar disc derived from the Hubble formula and, via Monte Carlo simulations, find a strong lack of a correlation (at ≫5σ) implying either widespread feeding via mergers if we assume the sample to be homogeneous, or that radiative disc warps are distorting our view of the emission. However, we find that by removing a small (˜1/5) subset of AGN, the remaining sample is consistent with random sampling of an underlying 1:1 correlation (at the 3σ level). A heterogenous sample would likely imply that our view is not dominated by radiative disc warps but instead by different feeding mechanisms with the majority consistent with coplanar accretion (although this may be the result of selection bias), whilst a smaller but not insignificant fraction may have been fuelled by minor mergers in the recent history of the host galaxy.

  2. The AGN Jet Model of the Fermi Bubbles

    NASA Astrophysics Data System (ADS)

    Guo, Fulai

    2017-01-01

    The nature and origin of the Fermi bubbles detected in the inner Galaxy remain elusive. In this paper, we briefly discuss some recent theoretical and observational developments, with a focus on the AGN jet model. Analogous to radio lobes observed in massive galaxies, the Fermi bubbles could be naturally produced by a pair of opposing jets emanating nearly along the Galaxy's rotation axis from the Galactic center. Our two-fluid hydrodynamic simulations reproduce quite well the bubble location and shape, and interface instabilities at the bubble surface could be effectively suppressed by shear viscosity. We briefly comment on some potential issues related to our model, which may lead to future progress.

  3. Characterizing X-ray Variability Processes in AGN

    NASA Astrophysics Data System (ADS)

    Markowitz, A.

    2006-07-01

    We comment on searches for characteristic X-ray variability time- scales in the red-noise light curves of Active Galactic Nuclei (AGN). Methods for identification of such features and determining their statistical significance are discussed. Pros and cons of two common tools, the power spectral density function (PSD) and the structure function (SF), are reviewed. Caveats associated with identification of quasi-periodic oscillations (QPOs) in the presence of red-noise variability are also discussed. A central point of this paper is to make all readers aware that there already exist good references out there for determining the statistical significance of claims of characteristic variability time scales.

  4. The KMOS AGN Survey at High redshift (KASHz): the prevalence and drivers of ionized outflows in the host galaxies of X-ray AGN

    NASA Astrophysics Data System (ADS)

    Harrison, C. M.; Alexander, D. M.; Mullaney, J. R.; Stott, J. P.; Swinbank, A. M.; Arumugam, V.; Bauer, F. E.; Bower, R. G.; Bunker, A. J.; Sharples, R. M.

    2016-02-01

    We present the first results from the KMOS (K-band Multi-Object Spectrograph) AGN (active galactic nuclei) Survey at High redshift (KASHz), a VLT/KMOS integral-field spectroscopic (IFS) survey of z ≳ 0.6 AGN. We present galaxy-integrated spectra of 89 X-ray AGN (L2-10 keV = 1042-1045 erg s-1), for which we observed [O III] (z ≈ 1.1-1.7) or Hα emission (z ≈ 0.6-1.1). The targets have X-ray luminosities representative of the parent AGN population and we explore the emission-line luminosities as a function of X-ray luminosity. For the [O III] targets, ≈50 per cent have ionized gas velocities indicative of gas that is dominated by outflows and/or highly turbulent material (i.e. overall line widths ≳600 km s-1). The most luminous half (i.e. LX > 6 × 1043 erg s-1) have a ≳2 times higher incidence of such velocities. On the basis of our results, we find no evidence that X-ray obscured AGN are more likely to host extreme kinematics than unobscured AGN. Our KASHz sample has a distribution of gas velocities that is consistent with a luminosity-matched sample of z < 0.4 AGN. This implies little evolution in the prevalence of ionized outflows, for a fixed AGN luminosity, despite an order-of-magnitude decrease in average star formation rates over this redshift range. Furthermore, we compare our Hα targets to a redshift-matched sample of star-forming galaxies and despite a similar distribution of Hα luminosities and likely star formation rates, we find extreme ionized gas velocities are up to ≈10 times more prevalent in the AGN-host galaxies. Our results reveal a high prevalence of extreme ionized gas velocities in high-luminosity X-ray AGN and imply that the most powerful ionized outflows in high-redshift galaxies are driven by AGN activity.

  5. Optically Elusive AGN in the 3XMM Catalog and the Chandra-COSMOS field

    NASA Astrophysics Data System (ADS)

    Pons, Estelle; Watson, Mike; Elvis, Martin; Civano, Francesca M.

    2015-01-01

    'Optically elusive AGN' are powerful X-ray sources (LHX > 1042 erg/s), but are not detected as AGN in the optical. Pons and Watson (2014) showed that in XMM these AGNs are a mix of Narrow Line Seyfert 1s, True Seyfert 2's and weak Seyfert 2s. The nature of these objects, coming from the cross-match of 3XMM with the SDSS-DR9 spectroscopic catalog, has been investigated through a detailed analysis of their IR/optical and X-ray properties. The fainter Chandra-COSMOS field should be rich in optically elusive AGNs as ¾ of the AGNs there are narrow-lined. There are ~850 Chandra-COSMOS galaxy spectra, mainly from five different telescopes (SDSS, Magellan, MMT, VLT and Keck). To find optically elusive objects, we investigate the optical classification using emission line diagnostic diagrams. For low redshift galaxies (z~<0.7) the standard BPT diagram ([OIII

  6. A complete hard X-ray selected sample of local, luminous AGNs

    NASA Astrophysics Data System (ADS)

    Burtscher, Leonard; Davies, Ric; Lin, Ming-yi; Orban de Xivry, Gilles; Rosario, David

    2016-08-01

    Choosing a very well defined sample is essential for studying the AGN phenomenon. Only the most luminous AGNs can be expected to require a coherent feeding mechanism to sustain their activity and since host galaxy properties and AGN activity are essentially uncorrelated, nuclear scales must be resolved in order to shed light on the feeding mechanisms of AGNs. For these reasons we are compiling a sample of the most powerful, local AGNs. In this talk we present our on-going programme to observe a complete volume limited sample of nearby active galaxies selected by their 14-195 keV luminosity, and outline its rationale for studying the mechanisms regulating gas inflow and outflow.

  7. Type-II AGN population from the zCOSMOS survey

    NASA Astrophysics Data System (ADS)

    Bongiorno, A.; Mignoli, M.; Zamorani, G.; Zcosmos Team

    2008-10-01

    I'll present the first results on the type-II AGN population isolated from the zCOSMOS bright sample which consists of 10k sources, purely magnitude selected at I=22.5. The selected type-II AGN sample consists of about 200 AGN, selected using the diagnostic diagrams up to redshift ~1.0. I'll present the properties of this sample (i.e. SED and morphology) and some preliminary results on the evolution of type-II AGN, as well as on the evolution of their fraction with respect to the total AGN population (Type-I + Type-II), as a function of both luminosity and redshift.

  8. PRIMUS: The Dependence of AGN Accretion on Host Stellar Mass and Color

    NASA Astrophysics Data System (ADS)

    Aird, James; Coil, Alison L.; Moustakas, John; Blanton, Michael R.; Burles, Scott M.; Cool, Richard J.; Eisenstein, Daniel J.; Smith, M. Stephen M.; Wong, Kenneth C.; Zhu, Guangtun

    2012-02-01

    We present evidence that the incidence of active galactic nuclei (AGNs) and the distribution of their accretion rates do not depend on the stellar masses of their host galaxies, contrary to previous studies. We use hard (2-10 keV) X-ray data from three extragalactic fields (XMM-LSS, COSMOS, and ELAIS-S1) with redshifts from the Prism Multi-object Survey to identify 242 AGNs with L 2-10 keV = 1042-44 erg s-1 within a parent sample of ~25,000 galaxies at 0.2 < z < 1.0 over ~3.4 deg2 and to i ~ 23. We find that although the fraction of galaxies hosting an AGN at fixed X-ray luminosity rises strongly with stellar mass, the distribution of X-ray luminosities is independent of mass. Furthermore, we show that the probability that a galaxy will host an AGN can be defined by a universal Eddington ratio distribution that is independent of the host galaxy stellar mass and has a power-law shape with slope -0.65. These results demonstrate that AGNs are prevalent at all stellar masses in the range 9.5 and that the same physical processes regulate AGN activity in all galaxies in this stellar mass range. While a higher AGN fraction may be observed in massive galaxies, this is a selection effect related to the underlying Eddington ratio distribution. We also find that the AGN fraction drops rapidly between z ~ 1 and the present day and is moderately enhanced (factor ~2) in galaxies with blue or green optical colors. Consequently, while AGN activity and star formation appear to be globally correlated, we do not find evidence that the presence of an AGN is related to the quenching of star formation or the color transformation of galaxies.

  9. A Herschel Study of 24 μμm-Selected AGNs and Their Host Galaxies

    NASA Astrophysics Data System (ADS)

    Xu, Lei; Rieke, G. H.; Egami, E.; Pereira, M. J.; Haines, C. P.; Smith, G. P.

    2015-08-01

    We present a sample of 290 24 μm-selected active galactic nuclei (AGNs) mostly at z ˜ 0.3-2.5, within 5.2 {{deg}}2 distributed as 25\\prime × 25\\prime fields around each of 30 galaxy clusters in the Local Cluster Substructure Survey. The sample is nearly complete to 1 mJy at 24 μm, and has a rich multiwavelength set of ancillary data; 162 are detected by Herschel. We use spectral templates for AGNs, stellar populations, and infrared (IR) emission by star-forming galaxies to decompose the spectral energy distributions (SEDs) of these AGNs and their host galaxies, and estimate their star formation rates, AGN luminosities, and host galaxy stellar masses. The set of templates is relatively simple: a standard Type-1 quasar template; another for the photospheric output of the stellar population; and a far-infrared star-forming template. For the Type-2 AGN SEDs, we substitute templates including internal obscuration, and some Type-1 objects require a warm component (T≳ 50 K). The individually Herschel-detected Type-1 AGNs and a subset of 17 Type-2 AGNs typically have luminosities \\gt {10}45 {ergs} {{{s}}}-1, and supermassive black holes of ˜ 3× {10}8 {M}⊙ emitting at ˜10% of the Eddington rate. We find them in about twice the numbers of AGNs identified in SDSS data in the same fields, i.e., they represent typical high-luminosity AGNs, not an IR-selected minority. These AGNs and their host galaxies are studied further in an accompanying paper.

  10. Canadian Society of Nephrology Commentary on the 2012 KDIGO clinical practice guideline for glomerulonephritis: management of nephrotic syndrome in children.

    PubMed

    Samuel, Susan; Bitzan, Martin; Zappitelli, Michael; Dart, Allison; Mammen, Cherry; Pinsk, Maury; Cybulsky, Andrey V; Walsh, Michael; Knoll, Greg; Hladunewich, Michelle; Bargman, Joanne; Reich, Heather; Humar, Atul; Muirhead, Norman

    2014-03-01

    The KDIGO (Kidney Disease: Improving Global Outcomes) clinical practice guideline for management of glomerulonephritis was recently released. The Canadian Society of Nephrology convened a working group to review the recommendations and comment on their relevancy and applicability to the Canadian context. A subgroup of pediatric nephrologists reviewed the guideline statements for management of childhood nephrotic syndrome and agreed with most of the guideline statements developed by KDIGO. This commentary highlights areas in which there is lack of evidence and areas in need of translation of evidence into clinical practice. Areas of controversy or uncertainty, including the length of corticosteroid therapy for the initial presentation and relapses, definitions of steroid resistance, and choice of second-line agents, are discussed in more detail. Existing practice variation is also addressed.

  11. Sequential development of pulmonary hemorrhage with MPO-ANCA complicating anti-glomerular basement membrane antibody-mediated glomerulonephritis.

    PubMed

    Peces, R; Rodríguez, M; Pobes, A; Seco, M

    2000-05-01

    We report a case of rapidly progressive glomerulonephritis caused by anti-glomerular basement membrane (anti-GBM) antibodies that progressed to end-stage renal disease in a 67-year-old woman with diabetes. Intensive combined immunosuppressive therapy with methylprednisolone bolus, oral prednisone, and cyclophosphamide led to negativity of anti-GBM antibodies but was not able to restore renal function. After 28 months of hemodialysis, the patient suddenly presented with pulmonary hemorrhage. In this setting, high levels of myeloperoxidase (MPO)-antineutrophil cytoplasmic antibody (ANCA) and negative anti-GBM antibodies were found. Therapy with oral prednisone and cyclophosphamide led to resolution of pulmonary hemorrhage and negativity of MPO-ANCA.

  12. Hepatitis C eradication and improvement of cryoglobulinemia-associated rash and membranoproliferative glomerulonephritis with interferon and ribavirin after kidney transplantation

    PubMed Central

    Zeman, Marilyn; Campbell, Patricia; Bain, Vincent G

    2006-01-01

    Postrenal transplant hepatitis C is increasing in frequency due to the high prevalence of hepatitis C among patients with renal failure. Despite this, there is still no standard hepatitis C treatment available for renal transplanted recipients. Combination antiviral hepatitis C therapy, the standard of care in the nontransplant population, is generally avoided because of documented renal graft rejection secondary to interferon treatment. A case of a male patient with postrenal transplant hepatitis C, which was associated with cryoglobulinemia and glomerulonephritis of the graft, is presented. He was treated with standard interferon with ribavirin. Sustained viral clearance was achieved despite ongoing evidence of cryoglobulinemia. Renal function, which had been deteriorating before treatment, improved as evidenced by the stabilization of serum creatinine and marked improvement of proteinuria. In conclusion, in selected patients, combination antiviral therapy may still be a viable option postrenal transplant. PMID:16779461

  13. PRIMUS: INFRARED AND X-RAY AGN SELECTION TECHNIQUES AT 0.2 < z < 1.2

    SciTech Connect

    Mendez, Alexander J.; Coil, Alison L.; Aird, James; Diamond-Stanic, Aleksandar M.; Moustakas, John; Blanton, Michael R.; Cool, Richard J.; Eisenstein, Daniel J.; Wong, Kenneth C.; Zhu Guangtun

    2013-06-10

    We present a study of Spitzer/IRAC and X-ray active galactic nucleus (AGN) selection techniques in order to quantify the overlap, uniqueness, contamination, and completeness of each. We investigate how the overlap and possible contamination of the samples depend on the depth of both the IR and X-ray data. We use Spitzer/IRAC imaging, Chandra and XMM-Newton X-ray imaging, and spectroscopic redshifts from the PRism MUlti-object Survey to construct galaxy and AGN samples at 0.2 < z < 1.2 over 8 deg{sup 2}. We construct samples over a wide range of IRAC flux limits (SWIRE to GOODS depth) and X-ray flux limits (10 ks to 2 Ms). We compare IR-AGN samples defined using both the IRAC color selection of Stern et al. and Donley et al. with X-ray-detected AGN samples. For roughly similar depth IR and X-ray surveys, we find that {approx}75% of IR-selected AGNs are also identified as X-ray AGNs. This fraction increases to {approx}90% when comparing against the deepest X-ray data, indicating that at most {approx}10% of IR-selected AGNs may be heavily obscured. The IR-AGN selection proposed by Stern et al. suffers from contamination by star-forming galaxies at various redshifts when using deeper IR data, though the selection technique works well for shallow IR data. While similar overall, the IR-AGN samples preferentially contain more luminous AGNs, while the X-ray AGN samples identify a wider range of AGN accretion rates including low specific accretion rate AGNs, where the host galaxy light dominates at IR wavelengths. The host galaxy populations of the IR and X-ray AGN samples have similar rest-frame colors and stellar masses; both selections identify AGNs in blue, star-forming and red, quiescent galaxies.

  14. A historical study of American patients with anti-neutrophil cytoplasmic antibody negative pauci-immune glomerulonephritis.

    PubMed

    Shah, Shivani; Havill, John; Rahman, M Hafizur; Geetha, Duvuru

    2016-04-01

    Anti-neutrophil cytoplasmic antibodies (ANCA) play an important role in the pathogenesis of ANCA-associated vasculitis. The lack of ANCA antibodies may indicate a variation in clinical presentation and outcomes of this disease. We identified 74 adult patients between 1995 and 2009 with the diagnosis of pauci-immune glomerulonephritis. Demographics, histological features, and treatment outcomes were compared between ANCA-positive and ANCA-negative patients. These factors were correlated with renal function at presentation and follow-up. Of the 74 patients, 57 were ANCA-positive, and 17 were ANCA-negative. Demographics and mean Birmingham Vasculitis Activity Score were similar between ANCA-negative and ANCA-positive patients at presentation. Renal function was significantly worse at presentation in the ANCA-negative patients (eGFR 16.59 vs. 31.89 ml/min/1.73 m(2), p = 0.03). Patients in the ANCA-negative group had a significantly higher interstitial fibrosis score compared to the ANCA-positive group (2.1 vs.1.6, p = 0.04). The median time to remission was shorter in the ANCA-negative patients (51 vs. 78 days, p = 0.01). Long-term renal function and 1-year patient and renal survival were similar between ANCA-negative and ANCA-positive patients. Baseline eGFR, percentage of normal glomeruli, glomerular sclerosis, and tubulointerstitial scarring predicted eGFR at 1 year in both groups similarly. This is the first historical review of American patients with pauci-immune glomerulonephritis, comparing patients with ANCA-negative and ANCA-positive serology. Although ANCA-negative patients present with lower eGFR and more interstitial fibrosis, 1-year and long-term outcomes in both groups are similar.

  15. Hydrodynamics-based delivery of the viral interleukin-10 gene suppresses experimental crescentic glomerulonephritis in Wistar-Kyoto rats.

    PubMed

    Higuchi, N; Maruyama, H; Kuroda, T; Kameda, S; Iino, N; Kawachi, H; Nishikawa, Y; Hanawa, H; Tahara, H; Miyazaki, J; Gejyo, F

    2003-08-01

    Gene therapy is expected to revolutionize the treatment of kidney diseases. Viral interleukin (vIL)-10 has a variety of immunomodulatory properties. We examined the applicability of vIL-10 gene transfer to the treatment of rats with crescentic glomerulonephritis, a T helper 1 (Th 1) predominant disease. To produce the disease, Wistar-Kyoto rats were injected with a rabbit polyclonal anti-rat glomerular basement membrane antibody. After 3 h, a large volume of plasmid DNA expressing vIL-10 (pCAGGS-vIL-10) solution was rapidly injected into the tail vein. pCAGGS solution was similarly injected into control rats (pCAGGS rats). We confirmed the presence of vector-derived vIL-10 mainly in the liver and observed high serum vIL-10 levels in pCAGGS-vIL-10-injected rats. Compared with the pCAGGS rats, the pCAGGS-vIL-10 rats showed significant therapeutic effects: reduced frequency of crescent formation, decrease in the number of total cells, macrophages, and CD4+ T cells in the glomeruli, decrease in urine protein, and attenuation of kidney dysfunction. Using quantitative real-time polymerase chain reaction, we also observed that this model was Th1-predominant in the glomeruli and that the ratio of the transcripts of CD4, interferon-gamma, tumor necrosis factor-alpha, and monocyte chemotactic protein-1 to the transcripts of glucose-6-phosphate dehydrogenase in the glomeruli were all significantly lower in the pCAGGS-vIL-10 rats than in the pCAGGS rats. These results demonstrate that pCAGGS-vIL-10 gene transfer by hydrodynamics-based transfection suppresses crescentic glomerulonephritis.

  16. Inherited factor H dysfunction and complement-associated glomerulonephritis in renal grafts of first and second transplantations.

    PubMed

    Watanabe, S; Yamaguchi, Y; Suzuki, T; Ikezoe, M; Matsumoto, N; Chikamoto, H; Nagafuchi, H; Horita, S; Hattori, M; Shiraga, H; Tokumoto, T; Tanabe, K; Toma, H; Ito, K

    2001-01-01

    A 38-yr-old man with factor H dysfunction and unknown glomerular disease received first and second renal transplantations (Tx) from living-related donors. His examination showed a low percentage activity of factor H (31%). Factor H dysfunction has been known to be associated with type II or III membranoproliferative glomerulonephritis (MPGN), haemolytic uraemic syndrome and IgA GN. The first graft from his mother showed diffuse mesangial deposit of IgA. His son has had IgA GN and his data also revealed a low percentage activity of factor H (33%). He and his son both showed a low activity of C3. Moreover, his father, who was the donor of the second Tx, had a low percentage activity of factor H (25%), and presented with mild glomerular deposit of C3 at operation, while he has been healthy through his entire 67 yr of life. Each of them had a low percentage activity of factor H. These findings through three generations suggested the inheritance of factor H dysfunction. The patient presented with proteinuria 3 months after the first Tx. At the first biopsy 30 months after the first Tx, light microscopy revealed minor glomerular abnormalities with electron dense deposits in subepithelial, intramembranous and mesangial regions, while immunofluorescence showed massive glomerular deposits of C3. In the second biopsy 51 months after the first Tx, the glomerulonephritis developed mesangial proliferation and crescent formation, accompanied by more massive C3 deposit and intramembranous, mesangial and subepithelial dense deposits. He then required redialysis. At the second and third biopsies within 2 months after the second Tx, the renal graft showed similar findings to the first biopsy after the first Tx. He perhaps presented with a recurrence of complement-associated GN, showing an atypical form of MPGN after Tx. These findings suggest that factor H dysfunction may play an important role of a certain pathogenesis of GN.

  17. 'Harder when Brighter' Spectral Variability in Low-Luminosity AGN

    NASA Astrophysics Data System (ADS)

    Connolly, S.; McHardy, I.; Skipper, C.; Dwelly, T.

    2015-07-01

    We present X-ray spectral variability of four low accretion rate AGN - M81, NGC 1097, NGC 1052 and NGC 3998 - as observed by Swift and RXTE. All four objects were selected due to having spectra which hardened with increasing count rate, converse to the `softer when brighter' behaviour normally observed in AGN with higher accretion rates. The spectra were summed in flux bins and fitted with a variety of models. A simple absorbed power law model was found to fit the spectra of M81, NGC 1097 and NGC 3998 well, whilst NGC 1052 required a partially covered power law model. In all four cases, the most likely main source of spectral variability is found to be luminosity-dependent changes in the photon index of the power law component. An anticorrelation between the photon index and the count rate is found in all of the sources. The anticorrelation is likely to be caused by accretion via a radiatively-inefficient accretion flow, expected in low-Eddington ratio systems such as these, and/or due to the presence of a jet. This behaviour is similar to that seen in the `hard state' of X-ray binaries, implying that these LLAGN are in a similar state.

  18. The faint radio AGN population in the spotlight

    NASA Astrophysics Data System (ADS)

    Herrera Ruiz, Noelia; Middelberg, Enno

    2016-08-01

    To determine the AGN component in the faint radio population is fundamental in galaxy evolution studies. A relatively easy and direct way to determine which galaxies do have a radio-active AGN is a detection using the Very Long Baseline Interferometry (VLBI) technique. The goal of this project is to study with statistically relevant numbers the faint radio source population using VLBI observations. To achieve this goal, the project is divided into two parts. In the first part, we have observed ~3000 radio sources in the COSMOS extragalactic field with the Very Long Baseline Array (VLBA) at 1.4GHz. We have detected 468 sources. In the second part, we have observed ~200 radio sources in the COSMOS field with extremely high sensitivity using the VLBA together with the Green Bank Telescope (GBT) at 1.4GHz, to explore an even fainter population in the flux density regime of tens of uJy. We are currently calibrating this data. In this overview I will present the survey design, observations, and calibration, along with some first results.

  19. Simulations of the OzDES AGN reverberation mapping project

    SciTech Connect

    King, Anthea L.; Martini, Paul; Davis, Tamara M.; Denney, K. D.; Kochanek, C. S.; Peterson, Bradley M.; Skielboe, Andreas; Vestergaard, Marianne; Huff, Eric; Watson, Darach; Banerji, Manda; McMahon, Richard; Sharp, Rob; Lidman, C.

    2015-08-26

    As part of the Australian spectroscopic dark energy survey (OzDES) we are carrying out a large-scale reverberation mapping study of ~500 quasars over five years in the 30 deg2 area of the Dark Energy Survey (DES) supernova fields. These quasars have redshifts ranging up to 4 and have apparent AB magnitudes between 16.8 mag < r < 22.5 mag. The aim of the survey is to measure time lags between fluctuations in the quasar continuum and broad emission-line fluxes of individual objects in order to measure black hole masses for a broad range of active galactic nuclei (AGN) and constrain the radius–luminosity (R–L) relationship. Here we investigate the expected efficiency of the OzDES reverberation mapping campaign and its possible extensions. We expect to recover lags for ~35–45 % of the quasars. AGN with shorter lags and greater variability are more likely to yield a lag measurement, and objects with lags ≲6 months or ~1 yr are expected to be recovered the most accurately. The baseline OzDES reverberation mapping campaign is predicted to produce an unbiased measurement of the R–L relationship parameters for Hβ, MgIIλ2798, and C IVλ1549. As a result, extending the baseline survey by either increasing the spectroscopic cadence, extending the survey season, or improving the emission-line flux measurement accuracy will significantly improve the R–L parameter constraints for all broad emission lines.

  20. XMM-Newton, powerful AGN winds and galaxy feedback

    NASA Astrophysics Data System (ADS)

    Pounds, K.; King, A.

    2016-06-01

    The discovery that ultra-fast ionized winds - sufficiently powerful to disrupt growth of the host galaxy - are a common feature of luminous AGN is major scientific breakthrough led by XMM-Newton. An extended observation in 2014 of the prototype UFO, PG1211+143, has revealed an unusually complex outflow, with distinct and persisting velocities detected in both hard and soft X-ray spectra. While the general properties of UFOs are consistent with being launched - at the local escape velocity - from the inner disc where the accretion rate is modestly super-Eddington (King and Pounds, Ann Rev Astron Astro- phys 2015), these more complex flows have raised questions about the outflow geometry and the importance of shocks and enhanced cooling. XMM-Newton seems likely to remain the best Observatory to study UFOs prior to Athena, and further extended observations, of PG1211+143 and other bright AGN, have the exciting potential to establish the typical wind dynamics, while providing new insights on the accretion geometry and continuum source structure. An emphasis on such large, coordinated observing programmes with XMM-Newton over the next decade will continue the successful philosophy pioneered by EXOSAT, while helping to inform the optimum planning for Athena

  1. AGN-Induced Cavities in NGC 1399 And NGC 4649

    SciTech Connect

    Shurkin, K.; Dunn, R.J.H.; Gentile, G.; Taylor, G.B.; Allen, S.W.; /KIPAC, Menlo Park

    2007-11-14

    We present an analysis of archival Chandra and VLA observations of the E0 galaxy NGC1399 and the E2 galaxy NGC4649 in which we investigate cavities in the surrounding X-ray emitting medium caused by the central AGN. We calculate the jet power required for the AGN to evacuate these cavities and find values of {approx} 8x10{sup 41} erg s-1 and {approx} 14x10{sup 41} erg s{sup -1} for the lobes of NGC1399 and {approx} 7x10{sup 41} erg s{sup -1} and {approx} 6x1041 erg s{sup -1} for those of NGC4649. We also calculate the k/f values for each cavity, where k is the ratio of the total particle energy to that of electrons radiating in the range of 10 MHz to 10 GHz, and f is the volume filling factor of the plasma in the cavity. We find that the values of k/f for the lobes of NGC1399 are {approx} 93 and {approx} 190, and those of the lobes of NGC4649 are {approx} 15000 and {approx} 12000. We conclude that the assumed spectrum describes the electron distribution in the lobes of NGC1399 reasonably well, and that there are few entrained particles. For NGC4649, either there are many entrained particles or the model spectrum does not accurately describe the population of electrons.

  2. An AGN Identification for 3EG J2006-2321

    NASA Technical Reports Server (NTRS)

    Wallace, P. M.; Halpern, J. P.; Magalhaes, A. M.; Thompson, D. J.; White, Nicholas E. (Technical Monitor)

    2001-01-01

    We present a multiwavelength analysis of the high-energy gamma-ray source 3EG J2006-2321 (l = 18 deg.82, b = -26 deg.26). The flux of this source above 100 MeV is shown to be variable on time scales of days and months. Optical observations and careful examination of archived radio data indicate that its most probable identification is with PMN J2005-2310, a flat-spectrum radio quasar with a 5GHz flux density of 260 mJy. Study of the V = 19.3 optical counterpart indicates a redshift of 0.833 and variable linear polarization. No X-ray source has been detected near the position of PMN J2005-2310, but an X-ray upper limit is derived from ROSAT data. This upper limit provides for a spectral energy distribution with global characteristics similar to those of known gamma-ray blazars. Taken together, these data indicate that 3EG J2006-2321, listed as unidentified in the 3rd EGRET Catalog, is a member of the blazar class of AGN. The 5-GHz radio flux density of this blazar is the lowest of the 68 EGRET-detected AGN. The fact that EGRET has detected such a source has implications for unidentified EGRET sources, particularly those at high latitudes (absolute value of b greater than 30 deg), many of which may be blazars.

  3. Cystitis - acute

    MedlinePlus

    Uncomplicated urinary tract infection; UTI - acute cystitis; Acute bladder infection; Acute bacterial cystitis ... cause. Menopause also increases the risk for a urinary tract infection. The following also increase your chances of having ...

  4. The Origin of Double-peaked Narrow Lines in Active Galactic Nuclei. I. Very Large Array Detections of Dual AGNs and AGN Outflows

    NASA Astrophysics Data System (ADS)

    Müller-Sánchez, F.; Comerford, J. M.; Nevin, R.; Barrows, R. S.; Cooper, M. C.; Greene, J. E.

    2015-11-01

    We have examined a subset of 18 active galactic nuclei (AGNs) drawn from a sample of 81 galaxies that possess double-peaked narrow optical emission line spectra in the Sloan Digital Sky Survey, have 2 optical AGN emission components separated by >0.″2, and are detected in the Faint Images of the Radio Sky at Twenty-centimeters survey. Without follow-up observations, the sources of the double-peaked narrow emission lines are uncertain, and may be produced by kiloparsec-scale separation dual active supermassive black holes, AGN outflows, or disk rotation. In this work, we propose a new methodology to characterize double-peaked narrow emission line galaxies based on optical long-slit spectroscopy and high-resolution multi-band Very Large Array observations. The nature of the radio emission in the sample galaxies is varied. Of the 18 galaxies, we detect 2 compact flat-spectrum radio cores with projected spatial separations on the sky between 0.6 and 1.6 kpc in 3 galaxies: J1023+3243, J1158+3231, and J1623+0808. The two radio sources are spatially coincident with the two optical components of ionized gas with AGN-like line ratios, which confirms the presence of dual AGNs in these three galaxies. Dual AGNs account for only ∼15% (3/18) of the double-peaked AGNs in our sample. Gas kinematics produce ∼75% (13/18) of the double-peaked narrow emission lines, distributed in the following way: seven AGN wind-driven outflows, five radio-jet driven outflows, and one rotating narrow-line region. The remaining 10% (2/18) are ambiguous cases. Our method demonstrates the power of spatially resolved spectroscopy and high-resolution radio observations for the identification of AGN outflows and AGN pairs with angular separations as small as 0.″18. Based on observations at the NRAO Karl G. Jansky VLA (program 12A-103).

  5. The ``entropy floor'' is porous - remarks on the coexistence of star formation and kinetic AGN feedback

    NASA Astrophysics Data System (ADS)

    Tremblay, Grant R.

    2014-07-01

    We discuss the morphology of star forming clouds and filaments in the central (<~ 50 kpc) regions of 16 low redshift (z<0.3) cool core brightest cluster galaxies (BCGs). The sample spans decades-wide ranges of X-ray mass deposition and star formation rates as well as active galactic nucleus (AGN) mechanical power, encompassing both high and low extremes of the supposed intracluster medium (ICM) cooling and AGN heating feedback cycle. Amid evidence that the gas fueling both star formation and AGN activity has condensed from the hot atmosphere, we present new and archival Hubble Space Telescope (HST) images of far ultraviolet (FUV) continuum emission directly associated with young stars, acting as a calorimeter for the degree to which the suppression of star formation by AGN mechanical feedback may be spatially or temporally inefficient. We discuss evidence for temporal and possibly cyclical variation in star formation rate, wherein elevated cooling episodes are permitted when AGN feedback is in a low-power state, and vice-versa. Several sources exhibit strong morphological evidence that low levels of star formation can survive and may indeed be triggered by the passage of a propagating radio source. We conclude by discussing the apparent coexistence of feedback and star formation. If AGN mechanical power does establish an ``entropy floor'', this floor must be porous, or raise and lower as the AGN varies in power.

  6. Binary Black Holes, Accretion Disks and Relativistic Jets: Photocenters of Nearby AGN and Quasars

    NASA Technical Reports Server (NTRS)

    Wehrle, Ann E.; Jones, Dayton L.; Meier, David L.; Piner, B. Glenn; Unwin, Stephen C.

    2004-01-01

    One of the most challenging questions in astronomy today is to understand the origin, structure, and evolution of the central engines in the nuclei of quasars and active galaxies (AGNs). The favoured theory involves the activation of relativistic jets from the fueling of a supermassive black hole through an accretion disk. In some AGN an outer optically thick, dusty torus is seen orbiting the black hole system. This torus is probably related to an inner accretion disk - black hole system that forms the actual powerhouse of the AGN. In radio-loud AGN two oppositely-directed radio jets are ejected perpendicular to the torus/disk system. Although there is a wealth of observational data on AGN, some very basic questions have not been definitively answered. The Space Interferometry Mission (SIM) will address the following three key questions about AGN. 1) Does the most compact optical emission from an AGN come from an accretion disk or from a relativistic jet? 2) Does the separation of the radio core and optical photocenter of the quasars used for the reference frame tie, change on the timescales of their photometric variability, or is the separation stable at the level of a few microarcseconds? 3) Do the cores of galaxies harbor binary supermassive black holes remaining from galaxy mergers? It is not known whether such mergers are common, and whether binaries would persist for a significant time.

  7. The cosmic evolution of massive black holes in the Horizon-AGN simulation

    NASA Astrophysics Data System (ADS)

    Volonteri, M.; Dubois, Y.; Pichon, C.; Devriendt, J.

    2016-08-01

    We analyse the demographics of black holes (BHs) in the large-volume cosmological hydrodynamical simulation Horizon-AGN. This simulation statistically models how much gas is accreted on to BHs, traces the energy deposited into their environment and, consequently, the back-reaction of the ambient medium on BH growth. The synthetic BHs reproduce a variety of observational constraints such as the redshift evolution of the BH mass density and the mass function. Strong self-regulation via AGN feedback, weak supernova feedback, and unresolved internal processes result in a tight BH-galaxy mass correlation. Starting at z ˜ 2, tidal stripping creates a small population of BHs over-massive with respect to the halo. The fraction of galaxies hosting a central BH or an AGN increases with stellar mass. The AGN fraction agrees better with multi-wavelength studies, than single-wavelength ones, unless obscuration is taken into account. The most massive haloes present BH multiplicity, with additional BHs gained by ongoing or past mergers. In some cases, both a central and an off-centre AGN shine concurrently, producing a dual AGN. This dual AGN population dwindles with decreasing redshift, as found in observations. Specific accretion rate and Eddington ratio distributions are in good agreement with observational estimates. The BH population is dominated in turn by fast, slow, and very slow accretors, with transitions occurring at z = 3 and z = 2, respectively.

  8. Towards an understanding of the Radio-mode AGN Feedback at higher redshifts

    NASA Astrophysics Data System (ADS)

    Bîrzan, Laura

    2015-08-01

    Direct evidence for feedback by active galactic nuclei (AGN) on the intra-cluster medium (ICM) of nearby groups and clusters has been provided by Chandra X-ray images. They show that the radio lobes emitted by the AGN create cavities in the hot cluster atmosphere, whichaffects the cooling gas that leads to star formation and galaxy growth and allow a direct measurement of the bulk of the AGN's power. Consequently, AGN feedback is now recognized as a necessary ingredient for galaxy formation models to prevent overcooling in massive halos. It is therefore important to study AGN feedback at redshifts where clusters are known to form (z ~ 1) and AGN feedback is predicted to regulate star formation in the most massive galaxies. Together with radio data, the cavities allow us to derive scaling relations that can be used to estimate the AGN feedback power using only radio data. I will review the importance of such relations for extending current studies of feedback with new and upcoming radio telescopes such as LOFAR and SKA, and I will present preliminary results from deep low-frequency LOFAR observations of the NEP field to understand if the local cooling-to-heating balance and the corresponding scaling relations (between jet power and radio luminosity) hold at these redshifts (z > 0.5).

  9. Dissecting galaxies: spatial and spectral separation of emission excited by star formation and AGN activity

    NASA Astrophysics Data System (ADS)

    Davies, Rebecca L.; Groves, Brent; Kewley, Lisa J.; Dopita, Michael A.; Hampton, Elise J.; Shastri, Prajval; Scharwächter, Julia; Sutherland, Ralph; Kharb, Preeti; Bhatt, Harish; Jin, Chichuan; Banfield, Julie; Zaw, Ingyin; James, Bethan; Juneau, Stéphanie; Srivastava, Shweta

    2016-10-01

    The optical spectra of Seyfert galaxies are often dominated by emission lines excited by both star formation and active galactic nucleus (AGN) activity. Standard calibrations (such as for the star formation rate) are not applicable to such composite (mixed) spectra. In this paper, we describe how integral field data can be used to spectrally and spatially separate emission associated with star formation from emission associated with accretion on to an AGN. We demonstrate our method using integral field data for two AGN host galaxies (NGC 5728 and NGC 7679) from the Siding Spring Southern Seyfert Spectroscopic Snapshot Survey (S7). The spectra of NGC 5728 and NGC 7679 form clear sequences of AGN fraction on standard emission line ratio diagnostic diagrams. We show that the emission line luminosities of the majority (>85 per cent) of spectra along each AGN fraction sequence can be reproduced by linear superpositions of the emission line luminosities of one AGN dominated spectrum and one star formation dominated spectrum. We separate the Hα, Hβ, [N II]λ6583, [S II]λλ6716, 6731, [O III]λ5007 and [O II]λλ3726, 3729 luminosities of every spaxel into contributions from star formation and AGN activity. The decomposed emission line images are used to derive the star formation rates and AGN bolometric luminosities for NGC 5728 and NGC 7679. Our calculated values are mostly consistent with independent estimates from data at other wavelengths. The recovered star-forming and AGN components also have distinct spatial distributions which trace structures seen in high-resolution imaging of the galaxies, providing independent confirmation that our decomposition has been successful.

  10. AGN Clustering in the Local Universe: An Unbiased Picture from Swift-BAT

    SciTech Connect

    Cappelluti, N.; Ajello, M.; Burlon, D.; Krumpe, M.; Miyaji, T.; Bonoli, S.; Greiner, J.; /Garching, Max Planck Inst., MPE

    2011-08-11

    We present the clustering measurement of hard X-ray selected AGN in the local Universe. We used a sample of 199 sources spectroscopically confirmed detected by Swift-BAT in its 15-55 keV all-sky survey. We measured the real space projected auto-correlation function and detected a signal significant on projected scales lower than 200 Mpc/h. We measured a correlation length of r{sub 0} = 5.56{sup +0.49}{sub -0.43} Mpc/h and a slope {gamma} = 1.64{sup -0.08}{sub -0.07}. We also measured the auto-correlation function of Tyep I and Type II AGN and found higher correlation length for Type I AGN. We have a marginal evidence of luminosity dependent clustering of AGN, as we detected a larger correlation length of luminous AGN than that of low luminosity sources. The corresponding typical host DM halo masses of Swift-BAT are {approx} log(M{sub DMH) {approx} 12-14 h{sup -1}M/M{sub {circle_dot}} which is the typical mass of a galaxy group. We estimated that the local AGN population has a typical lifetime {tau}{sub AGN} {approx}0.7 Gyr, it is powered by SMBH with mass M{sub BH} {approx}1-10x10{sup 8} M{sub {circle_dot}} and accreting with very low efficiency, log({epsilon}){approx}-2.0>. We also conclude that local AGN galaxies are typically red-massive galaxies with stellar mass of the order 2-80x10{sup 10} h{sup -1}M{sub {circle_dot}}. We compared our results with clustering predictions of merger-driven AGN triggering models and found a good agreement.

  11. Submillimetre observations of WISE/radio-selected AGN and their environments

    NASA Astrophysics Data System (ADS)

    Jones, Suzy F.; Blain, Andrew W.; Lonsdale, Carol; Condon, James; Farrah, Duncan; Stern, Daniel; Tsai, Chao-Wei; Assef, Roberto J.; Bridge, Carrie; Kimball, Amy; Lacy, Mark; Eisenhardt, Peter; Wu, Jingwen; Jarrett, Tom

    2015-04-01

    We present JCMT SCUBA-2 850 μm submillimetre (submm) observations of 30 mid-infrared (mid-IR) luminous active galactic nuclei (AGNs), detected jointly by the Wide-field Infrared Survey Explorer (WISE) all-sky IR survey and the NVSS/FIRST radio survey. These rare sources are selected by their extremely red mid-IR spectral energy distributions (SEDs) and compact radio counterparts. Further investigations show that they are highly obscured, have abundant warm AGN-heated dust and are thought to be experiencing intense AGN feedback. These galaxies appear to be consistent with a later AGN-dominated phase of merging galaxies, while hot, dust-obscured galaxies are an earlier starburst-dominated phase. When comparing the number of submm galaxies detected serendipitously in the surrounding 1.5 arcmin to those in blank-field submm surveys, there is a very significant overdensity, of order 5, but no sign of radial clustering centred at our primary objects. The WISE/radio-selected AGN thus reside in 10-Mpc-scale overdense environments that could be forming in pre-viralized clusters of galaxies. WISE/radio-selected AGNs appear to be the strongest signposts of high-density regions of active, luminous and dusty galaxies. SCUBA-2 850 μm observations indicate that their submm fluxes are low compared to many popular AGN SED templates, hence the WISE/radio-selected AGNs have either less cold and/or more warm dust emission than normally assumed for typical AGN. Most of the targets are not detected, only four targets are detected at SCUBA-2 850 μm, and have total IR luminosities ≥1013 L⊙, if their redshifts are consistent with the subset of the 10 SCUBA-2 undetected targets with known redshifts, z ˜ 0.44-2.86.

  12. X-ray selected AGN in groups at redshifts z ~ 1

    NASA Astrophysics Data System (ADS)

    Georgakakis, A.; Gerke, Brian F.; Nandra, K.; Laird, E. S.; Coil, A. L.; Cooper, M. C.; Newman, J. A.

    2008-11-01

    We explore the role of the group environment in the evolution of active galactic nuclei (AGN) at the redshift interval 0.7 < z < 1.4, by combining deep Chandra observations with extensive optical spectroscopy from the All-wavelength Extended Groth strip International Survey (AEGIS). The sample consists of 3902 optical sources and 71 X-ray AGN. Compared to the overall optically selected galaxy population, X-ray AGN are more frequently found in groups at the 99 per cent confidence level. This is partly because AGN are hosted by red luminous galaxies, which are known to reside, on average, in dense environments. Relative to these sources, the excess of X-ray AGN in groups is significant at the 91 per cent level only. Restricting the sample to 0.7 < z < 0.9 and MB < -20mag in order to control systematics, we find that X-ray AGN represent (4.7 +/- 1.6) and (4.5 +/- 1.0) per cent of the optical galaxy population in groups and in the field, respectively. These numbers are consistent with the AGN fraction in low-redshift clusters, groups and the field. The above results, although affected by small number statistics, suggest that X-ray AGN are spread over a range of environments, from groups to the field, once the properties of their hosts (e.g. colour, luminosity) are accounted for. There is also tentative evidence, significant at the 98 per cent level, that the field produces more X-ray luminous AGN compared to groups, extending similar results at low redshift to z ~ 1. This trend may be because of either cold gas availability or the nature of the interactions occurring in the denser group environment (i.e. prolonged tidal encounters).

  13. Host galaxies of luminous z ∼ 0.6 quasars: major mergers are not prevalent at the highest AGN luminosities

    NASA Astrophysics Data System (ADS)

    Villforth, C.; Hamilton, T.; Pawlik, M. M.; Hewlett, T.; Rowlands, K.; Herbst, H.; Shankar, F.; Fontana, A.; Hamann, F.; Koekemoer, A.; Pforr, J.; Trump, J.; Wuyts, S.

    2017-04-01

    Galaxy interactions are thought to be one of the main triggers of active galactic nuclei (AGN), especially at high luminosities, where the accreted gas mass during the AGN lifetime is substantial. Evidence for a connection between mergers and AGN, however, remains mixed. Possible triggering mechanisms remain particularly poorly understood for luminous AGN, which are thought to require triggering by major mergers, rather than secular processes. We analyse the host galaxies of a sample of 20 optically and X-ray selected luminous AGN (log(Lbol [erg s-1]) > 45) at z ∼ 0.6 using Hubble Space Telescope Wide Field Camera 3 data in the F160W/H band. 15/20 sources have resolved host galaxies. We create a control sample of mock AGN by matching the AGN host galaxies to a control sample of non-AGN galaxies. Visual signs of disturbances are found in about 25 per cent of sources in both the AGN hosts and control galaxies. Using both visual classification and quantitative morphology measures, we show that the levels of disturbance are not enhanced when compared to a matched control sample. We find no signs that major mergers play a dominant role in triggering AGN at high luminosities, suggesting that minor mergers and secular processes dominate AGN triggering up to the highest AGN luminosities. The upper limit on the enhanced fraction of major mergers is ≤20 per cent. While major mergers might increase the incidence of luminous AGN, they are not the prevalent triggering mechanism in the population of unobscured AGN.

  14. TORUS2015: The AGN unification scheme after 30 years

    NASA Astrophysics Data System (ADS)

    Gandhi, P.; Hoenig, S. F.

    2015-09-01

    The torus paradigm has proved to be remarkably successful at unifying the observed zoo of active galaxy (AGN) classes, despite having many manifest holes. The field is still data-driven with novel observational results at multiple wavelengths emerging rapidly. We are only now beginning to map out the structure of dusty gas feeding and obscuring AGN, and to model its evolution in galaxy growth. But these have also brought out several apparently contradictory results which must hold the key to future progress. As we celebrate 30 years of the paradigm, this is the perfect time to draw together our current knowledge and reassess the state of the field. This will be an international workshop at the University of Southampton, UK, with the objective of laying out the major challenges to the field and paving future research directions. Our hope is to facilitate plenty of informal discussions between multiwavelength observers and theorists, addressing some key issues: * What is the main driver in the unification scheme? What are the roles of orientation, mass accretion rate and feedback? * What is the nature and structure of gas and dust in the torus? Do we have a self-consistent picture across multiple wavelengths? * How critical is the role of the torus as an interface between small nuclear scales and large galactic scales? Does galaxy evolution necessarily require tori? * How close are we to self-consistently simulating nuclear activity including AGN feeding and nuclear star-formation? Workshop Rationale The three themes of accretion, orientation, and evolution will be covered through invited and solicited contributions. Different to other conferences, we are building each session around some key papers that have shaped the field or those with great future potential to do so. We specifically pit competing ideas against each other to help painting a realistic picture of the state-of-the-art. Each session will end with discussion rounds delving into important future

  15. The host galaxies of ultra hard X-ray selected AGN

    NASA Astrophysics Data System (ADS)

    Koss, Michael J.

    One of the great mysteries surrounding active galactic nuclei (AGN) is their triggering mechanism. Since the discovery that almost all massive galaxies host nuclear supermassive black holes, it has become clear that a trigger mechanism is required to 'turn on' and continue to fuel the central black hole. While it is established that accretion processes are responsible for the energy emitted, the source of the accreting material is still controversial. Furthermore, the energy input from phases of black hole growth is thought to be a key regulator in the formation of galaxies and the establishment of various scaling relations. Theorists often invoke galaxy mergers as the violent mechanism to drive gas into the central regions and ignite luminous quasars, but among more common moderate luminosity AGN, there has been great controversy whether secular processes or mergers dominate AGN fueling. A survey in the ultra hard X-ray band (14--195 keV) is an important new way to answer the fundamental question of AGN fueling. This method is independent of selection effects such as dust extinction and obscuration that plague surveys at other wavelengths because of the ability of the primary continuum to easily pass through large columns of obscuring gas and dust (<10 24 cm-2). In this PhD, we have assembled the largest sample of ultra hard X-ray selected AGN with host galaxy optical data to date, with 185 nearby (z<0.05), moderate luminosity AGN from the Swift BAT sample. We find that these AGN show much higher rates of both mergers and massive spirals suggesting both mergers and accretion of cold gas in late type systems are important in AGN fueling. We also find that the most common AGN survey technique, optical line diagnostics, is heavily biased against finding AGN in mergers or spirals. Finally, in agreement with the merger driven AGN link, we find that dual AGN systems may be more common than current observation suggest since some of them are only detected using high

  16. The host galaxies and narrow-line regions of four double-peaked [OIII] AGNs

    SciTech Connect

    Villforth, Carolin; Hamann, Fred

    2015-03-01

    Major gas-rich mergers of galaxies are expected to play an important role in triggering and fueling luminous active galactic nuclei (AGNs). The mechanism of AGN fueling during mergers, however, remains poorly understood. We present deep multi-band (u/r/z) imaging and long-slit spectroscopy of four double-peaked [OIII] emitting AGNs. This class of object is likely associated with either kiloparsec-separated binary AGNs or final stage major mergers, although AGNs with complex narrow-line regions (NLRs) are known contaminants. Such objects are of interest since they represent the onset of AGN activity during the merger process. Three of the four double-peaked [OIII] emitters studied have been confirmed as major mergers using near-infrared imaging and one is a confirmed X-ray binary AGN. All AGNs are luminous, radio-quiet to radio-intermediate, and have redshifts of 0.1AGN suggests that the merger of a binary black hole can take longer than 1 Gyr. All AGNs hosted by merging galaxies have companions at distances ⩽150 kpc. The NLRs have large sizes (10 kpc < r < 100 kpc) and consist of compact clumps with considerable relative velocities between components (∼200–650 km s{sup −1}). We detect broad, predominantly blue, wings with velocities up to ∼1500 km s{sup −1} in [OIII], indicative of powerful outflows. The outflows are compact (<5 kpc) and co-spatial with nuclear regions showing considerable reddening, consistent with enhanced star formation. One source shows an offset between gas and stellar kinematics, consistent with either a bipolar flow or a counter-rotating gas disk. In all other sources, the ionized gas

  17. VizieR Online Data Catalog: RM AGNs accretion rates and BH masses (Du+, 2016)

    NASA Astrophysics Data System (ADS)

    Du, P.; Wang, J.-M.; Hu, C.; Ho, L. C.; Li, Y.-R.; Bai, J.-M.

    2016-05-01

    We select all AGNs with reverberation mapping (RM) data (here only broad Hβ line), which yield robust BH mass estimates needed for our analysis. All RM AGNs before 2013 are summarized by Bentz et al. (2013ApJ...767..149B). Our project to search for super-Eddington accreting massive black holes (SEAMBHs) has monitored about 25 candidates and successfully measured Hβ lags ({tau}Hβ) in 14 AGNs to date (Du et al. 2015, J/ApJ/806/22) and other five objects monitored between 2014 and 2015 (to be submitted). See section 2 for further explanations. (2 data files).

  18. Preselecting AGN candidates from multi-wavelength data by ADTree

    NASA Astrophysics Data System (ADS)

    Zhang, Yanxia; Zheng, Hongwen; Zhao, Yongheng

    2005-03-01

    With the information era in astronomy coming, this "data avalanche" may provide many answers to important problems in contemporary astrophysics. The most important problem is sifting through massive amounts of data to mine knowledge. In this paper, we positionally cross-identify multi-wavelength data from optical, near-infrared, and x-ray bands, and then employ alternating decision trees (adtree) to quickly and robustly separate AGN candidates to a high degree of accuracy. We emphasise the application of the method due to the development of large survey projects and the establishment of the virtual observatory, and conclude that the application of data mining algorithms in astronomy is of great importance to discover new knowledge impossible to obtain before, and promote the development of astronomy.

  19. Au13-nAgn clusters: a remarkably simple trend.

    PubMed

    Munoz, Francisco; Varas, Alejandro; Rogan, José; Valdivia, Juan Alejandro; Kiwi, Miguel

    2015-11-11

    The planar to three dimensional transition of Au13-nAgn clusters is investigated. To do so the low lying energy configurations for all possible concentrations (n values) are evaluated. Many thousands of possible conformations are examined. They are generated using the procedure developed by Rogan et al. in combination with the semi-empirical Gupta potential. A large fraction of these (the low lying energy ones) are minimized by means of Density Functional Theory (DFT) calculations. We employ the Tao, Perdew, Staroverov, and Scuseria (TPSS) meta-GGA functional and the Perdew, Burke and Ernzerhof (PBE) GGA functional, and compare their results. The effect of spin-orbit coupling is studied as well as the s-d hybridization. As usual in this context the results are functional-dependent. However, both functionals lead to agreement as far as trends are concerned, yielding just two relevant motifs, but their results differ quantitatively.

  20. Relativistic Effects on Reflection X-ray Spectra of AGN

    SciTech Connect

    Lee, Khee-Gan; Fuerst, Steven V.; Brandwardi-Raymond, Graziella; Wu, Kinwah; Crowley, Oliver; /University Coll. London

    2007-01-05

    We have calculated the reflection component of the X-ray spectra of active galactic nuclei (AGN) and shown that they can be significantly modified by the relativistic motion of the accretion flow and various gravitational effects of the central black hole. The absorption edges in the reflection spectra suffer severe energy shifts and smearing. The degree of distortion depends on the system parameters, and the dependence is stronger for some parameters such as the inner radius of the accretion disk and the disk viewing inclination angles. The relativistic effects are significant and are observable. Improper treatment of the reflection component of the X-ray continuum in spectral fittings will give rise to spurious line-like features, which will mimic the fluorescent emission lines and mask the relativistic signatures of the lines.

  1. Cloudy Skies over AGN: Observations with Simbol-X

    NASA Astrophysics Data System (ADS)

    Salvati, M.; Risaliti, G.

    2009-05-01

    Recent time-resolved spectroscopic X-ray studies of bright obscured AGN show that column density variability on time scales of hours/days may be common, at least for sources with NH>1023 cm-2. This opens new oppurtunities in the analysis of the structure of the circumnuclear medium and of the X-ray source: resolving the variations due to single clouds covering/uncovering the X-ray source provides tight constraints on the source size, the clouds' size and distance, and their average number, density and column density. We show how Simbol-X will provide a breakthrough in this field, thanks to its broad band coverage, allowing (a) to precisely disentangle the continuum and NH variations, and (2) to extend the NH variability analysis to column densities >1023 cm-2.

  2. Synergy Between Observations of AGN with GLAST and MAXI

    SciTech Connect

    Madejski, Grzegorz

    2002-03-25

    In five years' time we will witness the launch of two important missions developed to observe celestial sources in the high energy regime: GLAST, sensitive in the high energy {gamma}-ray band, and MAXI, the all-sky X-ray monitor. Simultaneous monitoring observations by the two instruments will be particularly valuable for variable sources, allowing cross-correlations of time series between the two bands. We present the anticipated results from such observations of active galaxies, and in particular, of the jet-dominated sub-class of AGN known as blazars. We discuss the constraints on the structure and emission processes--and in particular, on the internal shock models currently invoked to explain the particle acceleration processes in blazars--that can be derived with simultaneous {gamma}-ray and X-ray data.

  3. [Hypocomplementary membrano-proliferative glomerulonephritis in a Malagasy patient with schistosomiasis mansoni (detection of bilharzial antigen on glomerular basement membrane using monoclonal antibodies)].

    PubMed

    Rajaonarivelo, P; Rajaona, H R; Alix, J L; Couderc, P; Daveau, C; Santoro, F; Nogueira-Quetroz, J A; Lovens, M; Capron, A; Cordonnier, D

    1986-01-01

    Schistosomiasis due to Schistosoma mansoni affects more than 40 millions people all over the world. Renal involvement is observed mainly in endemic areas. We report a case of hypocomplementemic membrano-proliferative glomerulonephritis in a malagasy man who suffered also from hepatosplenic bilharziosis. The relation between Schistosoma mansoni and the nephropathy was proved by indirect immunofluorescence test using a monoclonal antibody directed against the caecum of adult Schistosoma mansoni.

  4. Coordinated UV and X-ray Observations of AGN Outflows

    NASA Astrophysics Data System (ADS)

    Kriss, Gerard A.

    2017-01-01

    Observations of AGN outflows have progressed from the era of single-object surveys to intensive monitoring campaigns spanning weeks to months. The combination of multiple observations, improved temporal coverage, multi-wavelength monitoring in both the X-ray and UV bands, and the baseline of prior historical observations has enabled determinations of the locations, mass flux, and kinetic luminosities of the outflowing absorbing gas in several AGN. Typically the mass flux and kinetic energy are dominated by the higher-ionization X-ray absorbing gas. But the higher-resolution UV observations give a kinematically resolved picture of the overall outflow. In most cases, the outflowing gas is located at parsec to kpc scales, with insufficient kinetic luminosity to have an evolutionary impact on the host galaxy. Multiple coordinated observations have also revealed a new class of UV and X-ray absorbers. They typically show transient, heavy X-ray obscuration in the low-energy spectrum characterized by high column densities of mildly ionized gas. These X-ray obscuration events are accompanied by the appearance of broad, fast, blue-shifted UV absorption lines of moderate ionization, comparable to the X-ray absorbing gas. In the best-studied case of NGC 5548, the strength of the broad UV absorption lines varies with the degree of soft X-ray obscuration first revealed by XMM-Newton spectra. The high outflow velocities, variability timescales of a day or less in the X-ray, and the broad widths suggest an origin in a wind from the accretion disk. This low-ionization component may represent the shielding gas necessary to facilitate disk winds driven by radiative acceleration in UV absorption lines.

  5. The host galaxies of AGN with powerful relativistic jets

    NASA Astrophysics Data System (ADS)

    Olguín-Iglesias, A.; León-Tavares, J.; Kotilainen, J. K.; Chavushyan, V.; Tornikoski, M.; Valtaoja, E.; Añorve, C.; Valdés, J.; Carrasco, L.

    2016-08-01

    We present deep Near-infrared (NIR) images of a sample of 19 intermediate-redshift (0.3AGN) with powerful relativistic jets (L1.4GHz >10^27 WHz^-1), previously classified as flat-spectrum radio quasars. We also compile host galaxy and nuclear magnitudes for blazars from literature. The combined sample (this work and compilation) contains 100 radio-loud AGN with host galaxy detections and a broad range of radio luminosities L1.4GHz = 10^23.7 - 10^28.3WHz^-1, allowing us to divide our sample into high-excitation (quasar-mode; HERGs) and low-excitation (radio-mode; LERGs) radio galaxies. The host galaxies of our sample are bright and seem to follow the Kormendy relation. Nuclear emission (dominated by non-thermal mechanisms) and host-galaxy magnitudes show a slightly negative weak trend for LERGs. On the other hand, the m_bulge -m_nuc relation is statistically significant for HERGs. Although it may be affected by selection effects, this correlation suggests a close coupling between the relativistic jets and their host galaxy. Our findings are consistent with the excitation state (LERG/HERG) scenario. In this view, LERGs emit the bulk of their energy in the form of radio jets, producing a strong feedback mechanism, and HERGs are affected by galaxy mergers and interactions, which provide a common supply of cold gas to feed both nuclear activity and star formation episodes.

  6. Do the Kepler AGN light curves need reprocessing?

    NASA Astrophysics Data System (ADS)

    Kasliwal, Vishal P.; Vogeley, Michael S.; Richards, Gordon T.; Williams, Joshua; Carini, Michael T.

    2015-10-01

    We gauge the impact of spacecraft-induced effects on the inferred variability properties of the light curve of the Seyfert 1 AGN Zw 229-15 observed by Kepler. We compare the light curve of Zw 229-15 obtained from the Kepler MAST data base with a reprocessed light curve constructed from raw pixel data. We use the first-order structure function, SF(δt), to fit both light curves to the damped power-law PSD (power spectral density) of Kasliwal et al. On short time-scales, we find a steeper log PSD slope (γ = 2.90 to within 10 per cent) for the reprocessed light curve as compared to the light curve found on MAST (γ = 2.65 to within 10 per cent) - both inconsistent with a damped random walk (DRW) which requires γ = 2. The log PSD slope inferred for the reprocessed light curve is consistent with previous results that study the same reprocessed light curve. The turnover time-scale is almost identical for both light curves (27.1 and 27.5 d for the reprocessed and MAST data base light curves). Based on the obvious visual difference between the two versions of the light curve and on the PSD model fits, we conclude that there remain significant levels of spacecraft-induced effects in the standard pipeline reduction of the Kepler data. Reprocessing the light curves will change the model inferenced from the data but is unlikely to change the overall scientific conclusions reached by Kasliwal et al. - not all AGN light curves are consistent with the DRW.

  7. Simulations of the OzDES AGN reverberation mapping project

    DOE PAGES

    King, Anthea L.; Martini, Paul; Davis, Tamara M.; ...

    2015-08-26

    As part of the Australian spectroscopic dark energy survey (OzDES) we are carrying out a large-scale reverberation mapping study of ~500 quasars over five years in the 30 deg2 area of the Dark Energy Survey (DES) supernova fields. These quasars have redshifts ranging up to 4 and have apparent AB magnitudes between 16.8 mag < r < 22.5 mag. The aim of the survey is to measure time lags between fluctuations in the quasar continuum and broad emission-line fluxes of individual objects in order to measure black hole masses for a broad range of active galactic nuclei (AGN) and constrainmore » the radius–luminosity (R–L) relationship. Here we investigate the expected efficiency of the OzDES reverberation mapping campaign and its possible extensions. We expect to recover lags for ~35–45 % of the quasars. AGN with shorter lags and greater variability are more likely to yield a lag measurement, and objects with lags ≲6 months or ~1 yr are expected to be recovered the most accurately. The baseline OzDES reverberation mapping campaign is predicted to produce an unbiased measurement of the R–L relationship parameters for Hβ, MgIIλ2798, and C IVλ1549. As a result, extending the baseline survey by either increasing the spectroscopic cadence, extending the survey season, or improving the emission-line flux measurement accuracy will significantly improve the R–L parameter constraints for all broad emission lines.« less

  8. Acute Aspergillus pneumonia associated with mouldy tree bark-chippings, complicated by anti-glomerular basement membrane disease causing permanent renal failure☆

    PubMed Central

    Butler, Louise; Brockley, Tomos; Denning, David; Richardson, Malcolm; Chisholm, Roger; Sinha, Smeeta; O’Driscoll, Ronan

    2013-01-01

    A non-immunocompromised man developed acute Aspergillus pneumonia after spreading mouldy tree bark mulch. Despite normal renal function at presentation, he developed rapidly progressive glomerulonephritis with acute kidney injury due to anti-glomerular basement membrane antibodies (anti-GBM) 4 weeks later. He remained dialysis dependent and died of sepsis 10 months later. We hypothesise that he contracted invasive pulmonary Aspergillosis from heavy exposure to fungal spores, leading to epitope exposure in the alveoli with subsequent development of GBM auto-antibodies. PMID:24432235

  9. Presence of Anti-Glomerular Basement Membrane Antibodies and Myeloperoxidase Anti-Neutrophilic Cytoplasmic Antibodies in a Case of Rapidly Progressive Glomerulonephritis.

    PubMed

    Mavani, Gaurang P; Pommier, Max; Win, Sandar; Michelis, Michael F; Rosenstock, Jordan

    2015-01-01

    A 69-year-old male had initially presented with low-grade proteinuria, microhematuria, and a positive myeloperoxidase anti-neutrophilic antibody (ANCA). He subsequently developed deterioration of kidney function and developed uremic symptoms. Creatinine was 486.2 μmol/L (5.5 mg/dL). Anti-MPO was positive (titer >8 U, normal <0.4). He was clinically diagnosed with rapidly proliferative glomerulonephritis most likely due to ANCA vasculitis. He received three doses of pulse methylprednisolone therapy. Kidney biopsy showed pauci-immune glomerulonephritis. Immunofluorescence was positive for faint linear IgG staining of glomerular basement membrane (GBM). Anti-GBM antibody was positive 2.1 U (normal <1). He was started on high-dose oral steroids; monthly intravenous cyclophosphamide and plasmapheresis were also initiated. His symptoms improved and creatinine is 247.5 μmol/L (2.8 mg/dL). His repeat anti-GBM antibody was negative. This is a rare case of rapidly progressive glomerulonephritis due to dual MPO-ANCA antibodies and anti-GBM antibodies (DAV).

  10. Presence of Anti-Glomerular Basement Membrane Antibodies and Myeloperoxidase Anti-Neutrophilic Cytoplasmic Antibodies in a Case of Rapidly Progressive Glomerulonephritis

    PubMed Central

    Mavani, Gaurang P.; Pommier, Max; Win, Sandar; Michelis, Michael F.; Rosenstock, Jordan

    2015-01-01

    A 69-year-old male had initially presented with low-grade proteinuria, microhematuria, and a positive myeloperoxidase anti-neutrophilic antibody (ANCA). He subsequently developed deterioration of kidney function and developed uremic symptoms. Creatinine was 486.2 μmol/L (5.5 mg/dL). Anti-MPO was positive (titer >8 U, normal <0.4). He was clinically diagnosed with rapidly proliferative glomerulonephritis most likely due to ANCA vasculitis. He received three doses of pulse methylprednisolone therapy. Kidney biopsy showed pauci-immune glomerulonephritis. Immunofluorescence was positive for faint linear IgG staining of glomerular basement membrane (GBM). Anti-GBM antibody was positive 2.1 U (normal <1). He was started on high-dose oral steroids; monthly intravenous cyclophosphamide and plasmapheresis were also initiated. His symptoms improved and creatinine is 247.5 μmol/L (2.8 mg/dL). His repeat anti-GBM antibody was negative. This is a rare case of rapidly progressive glomerulonephritis due to dual MPO-ANCA antibodies and anti-GBM antibodies (DAV). PMID:26301224

  11. Fli-1 transcription factor affects glomerulonephritis development by regulating expression of monocyte chemoattractant protein-1 in endothelial cells in the kidney.

    PubMed

    Suzuki, Eiji; Karam, Eva; Williams, Sarah; Watson, Dennis K; Gilkeson, Gary; Zhang, Xian K

    2012-12-01

    Expression of transcription factor Fli-1 is implicated in the development of glomerulonephritis. Fli-1 heterozygous knockout (Fli1(+/-)) NZM2410 mice, a murine model of lupus, had significantly improved survival and reduced glomerulonephritis. In this study, we found that infiltrated inflammatory cells were significantly decreased in the kidneys from Fli-1(+/-) NZM2410 mice. The expression of monocyte chemoattractant protein-1 (MCP-1) was significantly decreased in kidneys from Fli-1(+/-) NZM2410 mice. The primary endothelial cells isolated from the kidneys of Fli-1(+/-) NZM2410 mice produced significantly less MCP-1. In endothelial cells transfected with specific Fli-1 siRNA the production of MCP-1 was significantly reduced compared to cells transfected with negative control siRNA. By Chromatin Immunoprecipitation (ChIP) assay, we further demonstrated that Fli-1 directly binds to the promoter of the MCP-1 gene. Our data indicate that Fli-1 impacts glomerulonephritis development by regulating expression of inflammatory chemokine MCP-1 and inflammatory cell infiltration in the kidneys in the NZM2410 mice.

  12. Beneficial effect of the inosine monophosphate dehydrogenase inhibitor mycophenolate mofetil on survival and severity of glomerulonephritis in systemic lupus erythematosus (SLE)-prone MRLlpr/lpr mice

    PubMed Central

    Jonsson, C A; Svensson, L; Carlsten, H

    1999-01-01

    The aim of the present study was to evaluate the therapeutic effect of mycophenolate mofetil (MMF) on the course of disease in SLE-prone MRLlpr/lpr mice. Three-months-old mice displaying clinical symptoms of glomerulonephritis were given MMF (100 mg/kg per day) orally via the drinking water. Control mice received i.p. injections of cyclophosphamide (CYC) (1.8 mg/mouse per week) or saline. Survival, albuminuria and haematuria, immunoglobulin levels and anti-dsDNA antibodies in serum, frequencies of immunoglobulin-producing B lymphocytes and glomerular deposits of immunoglobulin and C3 were analysed. The results showed that MMF treatment significantly prolonged survival and reduced the occurrence of albuminuria and haematuria in MRLlpr/lpr mice. In addition, the number of immunoglobulin-producing B cells and serum levels of IgG and IgG anti-dsDNA antibodies were reduced after MMF and CYC treatment. MMF treatment significantly reduced the extent of deposition of C3 in glomeruli. We conclude that the reduced severity of glomerulonephritis following treatment of lupus-prone mice with MMF was as efficacious as that of CYC. These results warrant clinical trials of MMF in SLE patients with glomerulonephritis. PMID:10361247

  13. Searching for Short Term Variable Active Galactic Nuclei: A Vital Step Towards Using AGN as Standard Candles

    NASA Astrophysics Data System (ADS)

    Kilts, Kelly; Gorjian, Varoujan; Rutherford, Thomas; Kohrs, Russell; Urbanowski, Vincent; Bellusci, Nina; Horton, Savannah; Jones, Dana; Jones, Kaytlyn; Pawelski, Peter; Tranum, Haley; Zhang, Emily

    2017-01-01

    Current models for accretion disk sizes of active galactic nuclei (AGN) do not match the limited observational data available, so there is an active need from the modeling community for many more accretion disk/dusty torus reverberation mapping campaigns with which to better calibrate models. Since short term variable AGN can be more easily monitored for reverberation mapping than long term variable AGN, they can begin to provide data more quickly. This project looked for short term variable AGN in the Young Stellar Object Variability (YSOVAR) survey conducted using the Spitzer Space Telescope. The YSOVAR survey targeted 12 nearby star forming regions for repeated observations. Potential AGN from the YSOVAR data were first selected by color ([3.6] - [4.5] > 0.4) and then by magnitude (m < 14) based on previous Spitzer surveys of known AGN. Since AGN share some similar color characteristics with young stars, images of each YSOVAR region were viewed to remove potential objects near concentrations of known young stellar objects since these were likely also YSOs. The spectral energy distribution (SED) for each remaining potential AGN was then examined for AGN like characteristics. Several potential short term variable AGN were found.

  14. Merger-driven fueling of active galactic nuclei: Six dual and of AGNs discovered with Chandra and Hubble Space Telescope observations

    DOE PAGES

    Comerford, Julia M.; Pooley, David; Barrows, R. Scott; ...

    2015-06-19

    Dual active galactic nuclei (AGNs) and offset AGNs are kpc-scale separation supermassive black holes pairs created during galaxy mergers, where both or one of the black holes are AGNs, respectively. These dual and offset AGNs are valuable probes of the link between mergers and AGNs but are challenging to identify. Here we present Chandra/ACIS observations of 12 optically selected dual AGN candidates atmore » $$z\\lt 0.34$$, where we use the X-rays to identify AGNs. We also present Hubble Space Telescope/Wide Field Camera 3 observations of 10 of these candidates, which reveal any stellar bulges accompanying the AGNs. We discover a dual AGN system with separation $${\\rm \\Delta }x=2.2$$ kpc, where the two stellar bulges have coincident [O iii] λ5007 and X-ray sources. This system is an extremely minor merger (460:1) that may include a dwarf galaxy hosting an intermediate mass black hole. We also find six single AGNs, and five systems that are either dual or offset AGNs with separations $${\\rm \\Delta }x\\lt 10$$ kpc. Four of the six dual AGNs and dual/offset AGNs are in ongoing major mergers, and these AGNs are 10 times more luminous, on average, than the single AGNs in our sample. This hints that major mergers may preferentially trigger higher luminosity AGNs. Further, we find that confirmed dual AGNs have hard X-ray luminosities that are half of those of single AGNs at fixed [O III] λ5007 luminosity, on average. Lastly, this could be explained by high densities of gas funneled to galaxy centers during mergers, and emphasizes the need for deeper X-ray observations of dual AGN candidates.« less

  15. Merger-driven Fueling of Active Galactic Nuclei: Six Dual and Offset AGNs Discovered with Chandra and Hubble Space Telescope Observations

    NASA Astrophysics Data System (ADS)

    Comerford, Julia M.; Pooley, David; Barrows, R. Scott; Greene, Jenny E.; Zakamska, Nadia L.; Madejski, Greg M.; Cooper, Michael C.

    2015-06-01

    Dual active galactic nuclei (AGNs) and offset AGNs are kpc-scale separation supermassive black holes pairs created during galaxy mergers, where both or one of the black holes are AGNs, respectively. These dual and offset AGNs are valuable probes of the link between mergers and AGNs but are challenging to identify. Here we present Chandra/ACIS observations of 12 optically selected dual AGN candidates at z\\lt 0.34, where we use the X-rays to identify AGNs. We also present Hubble Space Telescope/Wide Field Camera 3 observations of 10 of these candidates, which reveal any stellar bulges accompanying the AGNs. We discover a dual AGN system with separation Δ x=2.2 kpc, where the two stellar bulges have coincident [O iii] λ5007 and X-ray sources. This system is an extremely minor merger (460:1) that may include a dwarf galaxy hosting an intermediate mass black hole. We also find six single AGNs, and five systems that are either dual or offset AGNs with separations Δ x\\lt 10 kpc. Four of the six dual AGNs and dual/offset AGNs are in ongoing major mergers, and these AGNs are 10 times more luminous, on average, than the single AGNs in our sample. This hints that major mergers may preferentially trigger higher luminosity AGNs. Further, we find that confirmed dual AGNs have hard X-ray luminosities that are half of those of single AGNs at fixed [O iii] λ5007 luminosity, on average. This could be explained by high densities of gas funneled to galaxy centers during mergers, and emphasizes the need for deeper X-ray observations of dual AGN candidates.

  16. Merger-driven fueling of active galactic nuclei: Six dual and of AGNs discovered with Chandra and Hubble Space Telescope observations

    SciTech Connect

    Comerford, Julia M.; Pooley, David; Barrows, R. Scott; Greene, Jenny E.; Zakamska, Nadia L.; Madejski, Greg M.; Cooper, Michael C.

    2015-06-19

    Dual active galactic nuclei (AGNs) and offset AGNs are kpc-scale separation supermassive black holes pairs created during galaxy mergers, where both or one of the black holes are AGNs, respectively. These dual and offset AGNs are valuable probes of the link between mergers and AGNs but are challenging to identify. Here we present Chandra/ACIS observations of 12 optically selected dual AGN candidates at $z\\lt 0.34$, where we use the X-rays to identify AGNs. We also present Hubble Space Telescope/Wide Field Camera 3 observations of 10 of these candidates, which reveal any stellar bulges accompanying the AGNs. We discover a dual AGN system with separation ${\\rm \\Delta }x=2.2$ kpc, where the two stellar bulges have coincident [O iii] λ5007 and X-ray sources. This system is an extremely minor merger (460:1) that may include a dwarf galaxy hosting an intermediate mass black hole. We also find six single AGNs, and five systems that are either dual or offset AGNs with separations ${\\rm \\Delta }x\\lt 10$ kpc. Four of the six dual AGNs and dual/offset AGNs are in ongoing major mergers, and these AGNs are 10 times more luminous, on average, than the single AGNs in our sample. This hints that major mergers may preferentially trigger higher luminosity AGNs. Further, we find that confirmed dual AGNs have hard X-ray luminosities that are half of those of single AGNs at fixed [O III] λ5007 luminosity, on average. Lastly, this could be explained by high densities of gas funneled to galaxy centers during mergers, and emphasizes the need for deeper X-ray observations of dual AGN candidates.

  17. The 60 Month All-Sky Burst Alert Telescope Survey of Active Galactic Nucleus and the Anisotropy of Nearby AGNs

    NASA Technical Reports Server (NTRS)

    Ajello, M.; Alexander, D. M.; Greiner, J.; Madejeski, G. M.; Gehrels, N.; Burlon, D.

    2014-01-01

    Surveys above 10 keV represent one of the best resources to provide an unbiased census of the population of active galactic nuclei (AGNs). We present the results of 60 months of observation of the hard X-ray sky with Swift/Burst Alert Telescope (BAT). In this time frame, BAT-detected (in the 15-55 keV band) 720 sources in an all-sky survey of which 428 are associated with AGNs, most of which are nearby. Our sample has negligible incompleteness and statistics a factor of approx. 2 larger over similarly complete sets of AGNs. Our sample contains (at least) 15 bona fide Compton-thick AGNs and 3 likely candidates. Compton-thick AGNs represent approx. 5% of AGN samples detected above 15 keV. We use the BAT data set to refine the determination of the log N-log S of AGNs which is extremely important, now that NuSTAR prepares for launch, toward assessing the AGN contribution to the cosmic X-ray background. We show that the log N-log S of AGNs selected above 10 keV is now established to approx. 10% precision. We derive the luminosity function of Compton-thick AGNs and measure a space density of 7.9(+4.1/-2.9)× 10(exp -5)/cubic Mpc for objects with a de-absorbed luminosity larger than 2 × 10(exp 42) erg / s. As the BAT AGNs are all mostly local, they allow us to investigate the spatial distribution of AGNs in the nearby universe regardless of absorption. We find concentrations of AGNs that coincide spatially with the largest congregations of matter in the local (much < 85 Mpc) universe. There is some evidence that the fraction of Seyfert 2 objects is larger than average in the direction of these dense regions..

  18. Testing different AGN tracers on a local sample of Seyfert galaxies

    NASA Astrophysics Data System (ADS)

    Pozzi, F.

    2016-08-01

    I will present our new study on a local sample of Seyfert galaxies selected at 12 micron. This sample, given its plenty of information, both photometric and spectroscopic, is a perfect sample to compare, from a statistical point of view, different AGN selection criteria, and AGN derived intrinsic properties. In detail, I will compare AGN activity derived from SED-fitting technique, X-ray luminosity and AGN activity traced by high excitation IR lines, like [NeV] and [OIV]. Moreover, for one particular obscured X-ray Compton-thick source, thanks also to the availability of ALMA data, I will derive a self-consistent overview of the physics behind the emission in different bands,by taking advantage of the photoionization code CLOUDY.

  19. Downstream Effects of the Levee Overtopping at Wilkes-Barre, Pennsylvania During Tropical Storm Agnes.

    DTIC Science & Technology

    1973-04-01

    Davis, March 1973 36. Evaluation of Drought Effects at Lake Atitlan, Arlen D. Feldman 37. Downstream Effects of the Levee Overtopping at Wilkes-Barre, Pa., During Tropical Storm Agnes, Arlen D. Feldman, April 1973

  20. Characterizing the redshifts and luminosities of WISE selected obscured AGN using SALT optical spectra.

    NASA Astrophysics Data System (ADS)

    Hviding, Raphael E.; Hickox, Ryan C.; Hainline, Kevin N.; Carroll, Christopher M.; DiPompeo, Mike A.; Jones, Mackenzie L.

    2016-08-01

    We present the results of several optical spectroscopic surveys covering over 100 candidate luminous obscured active galactic nuclei (AGN) identified by their mid-infrared emission detected with the Wide-Field Infrared Survey Explorer (WISE). These galaxies were selected based on red WISE colors and galaxy-like optical emission, and were studied using long-slit optical spectroscopy with the Robert Stobie Spectrograph (RSS) on the Southern African Large Telescope (SALT). Our spectra were analyzed to obtain redshifts and emission line flux ratios for each galaxy. These results verify that WISE is an effective section method for luminous obscured AGN, allow for the characterization of redshifts and luminosities of the WISE color selected obscured AGN population, and could potentially contribute to large statistical studies of obscured AGN distributions in the future.

  1. Prospects for AGN Science using the ART-XC on the SRG Mission

    NASA Technical Reports Server (NTRS)

    Swartz, Douglas A.; Elsner, Ronald F.; Gubarev, Mikhail V.; O'Dell, Stephen L.; Ramsey, Brian D.; Bonamente, Massimiliano

    2012-01-01

    The enhanced hard X-ray sensitivity provided by the Astronomical Roentgen Telescope to the Spectrum Roentgen Gamma mission facilitates the detection of heavily obscured and other hard-spectrum cosmic X-ray sources. The SRG all-sky survey will obtain large, statistically-well-defined samples of active galactic nuclei (AGN) including a significant population of local heavily-obscured AGN. In anticipation of the SRG all-sky survey, we investigate the prospects for refining the bright end of the AGN luminosity function and determination of the local black hole mass function and comparing the spatial distribution of AGN with large-scale structure defined by galaxy clusters and groups. Particular emphasis is placed on studies of the deep survey Ecliptic Pole regions.

  2. Starburst and AGN Indicators in Optically Faint X-ray Sources in the Cosmic Evolution Survey

    NASA Astrophysics Data System (ADS)

    Robins, Derek; Elvis, M.; Civano, F.

    2011-01-01

    A sample of 55 faint, X-ray selected objects were chosen for analysis from the COSMOS survey with high quality Keck DEIMOS data. The average redshift of the sample was 1.36, consistent with the average redshift of type 1 AGN in COSMOS of 1.4. Emission lines, NeV - an indicator of AGN luminosity - and OII - an indicator of star formation rate, were measured for a subset of 34 objects. Line properties for these objects were measured. The combination of the two lines is evidence for significant star formation in these obscured AGN. Differences between OII and NeV redshifts were measured carefully. Significant differences between OII and NeV redshifts were found in 10-14 objects, implying OII outflows. The results are consistent with current models of galaxy evolution that invoke an interplay between AGN activity and star formation.

  3. Transient IgA nephropathy with acute kidney injury in a patient with dengue fever.

    PubMed

    Upadhaya, Bala Krishna; Sharma, Alok; Khaira, Ambar; Dinda, Amit K; Agarwal, Sanjay K; Tiwari, Suresh C

    2010-05-01

    Dengue virus infection can clinically manifest as dengue fever, dengue shock syndrome and dengue hemorrhagic fever. Acute kidney injury as a result of dengue virus infection can occur due to various reasons including hypotension, rhabdomyolysis, sepsis and rarely immune complex mediated glomerular injury. However, glomerulonephritis associated with IgA Nephropathy in dengue virus infection has not been reported previously. We report a case of 15-year-old boy who was admitted with dengue fever and dialysis dependant acute kidney injury. Urine examination showed microscopic glomerular hematuria and proteinuria. Kidney biopsy showed mesangial proliferation with mesangial IgA dominant immune complex deposits and acute tubular necrosis. A repeated kidney biopsy 6 weeks after clinical recovery showed reversal of glomerular changes as well as resolution of mesangial IgA deposits.

  4. Disentangling Dominance: Obscured AGN Activity versus Star Formation in BPT-Composites

    NASA Astrophysics Data System (ADS)

    Trouille, Laura

    2011-11-01

    Approximately 20% of SDSS emission-line galaxies (ELG) lie in the BPT-comp regime, between the Kauffmann et al. (2003) empirically determined SF-dominated regime and the Kewley et al. (2001) theoretically predicted AGN-dominated regime. BPT-AGN, on the other hand, make up only 11% of the ELG population. Whether to include the significant number of BPT-comp in samples of AGN or samples of star-forming galaxies is an open question and has important implications for galaxy evolution studies, metallicity studies, etc. Using a large pectroscopic sample of GOODS-N and LH galaxies with deep Chandra imaging, we perform an X-ray stacking analysis of BPT-comp. We find the stacked signal to be X-ray hard. This X-ray hardness can be indicative of obscured AGN activity or the presence of HMXBs associated with ongoing star formation. In order to distinguish between these scenarios, we perform an IR stacking analysis using Spitzer 24 micron data. The stacked BPT-comp lies well above the expected value for L_x/L_IR for pure star-forming galaxies; similarly for the X-ray detected BPT-comp. We also find that the BPT-comp lie in the AGN-dominated regime of our new TBT diagnostic, which uses [NeIII]/[OII] versus rest-frame g-z colour to identify AGN and star forming galaxies out to z=1.4. [NeIII], which has a higher ionisation potential than other commonly used forbidden emission lines, appears to foster a more reliable selection of AGN-dominated galaxies. These findings suggest that both the X-ray and optical signal in BPT-comp are dominated by obscured or low accretion rate AGN activity rather than star formation. This is in contrast to claims by previous optical emission-line studies that the signal in BPT-comp is dominated by star-formation activity. Therefore, we recommend that groups carefully consider the impact of excluding or including BPT-comp on the interpretation of their results. For example, for studies involving determining the bolometric contribution from AGN activity

  5. Autosomal dominant polycystic kidney disease with diffuse proliferative glomerulonephritis - an unusual association: a case report and review of the literature

    PubMed Central

    2010-01-01

    Introduction Autosomal dominant polycystic kidney disease is an inherited disorder that is characterized by the development and growth of cysts in the kidneys and other organs. Urinary protein excretion is usually less than 1 g/24 hours in autosomal dominant polycystic kidney disease, and an association of nephrotic syndrome with this condition is considered rare. There are only anecdotal case reports of autosomal dominant polycystic kidney disease associated with nephrotic syndrome, with focal segmental glomerulosclerosis being the most commonly reported histopathological diagnosis. Nephrotic-range proteinuria in the presence of autosomal dominant polycystic kidney disease, with or without an accompanying decline in renal function, should be investigated by open renal biopsy to exclude coexisting glomerular disease. To the best of our knowledge, this is the first case of autosomal dominant polycystic kidney disease with histologically proven diffuse proliferative glomerulonephritis presenting with nephrotic-range proteinuria. No other reports of this could be found in a global electronic search of the literature. Case presentation We report the case of a 35-year-old Indo-Aryan man with autosomal dominant polycystic kidney disease associated with nephrotic syndrome and a concomitant decline in his glomerular filtration rate. Open renal biopsy revealed diffuse proliferative glomerulonephritis. An accurate diagnosis enabled us to manage him conservatively with a successful outcome, without the use of corticosteroid which is the standard treatment and the drug most commonly used to treat nephrotic syndrome empirically. Conclusion Despite the reluctance of physicians to carry out a renal biopsy on patients with autosomal dominant polycystic kidney disease, our case supports the idea that renal biopsy is needed in patients with polycystic kidney disease with nephrotic-range proteinuria to make an accurate diagnosis. It also illustrates the importance of open renal

  6. From Nearby Low Luminosity AGN to High Redshift Radio Galaxies: Science Interests with Square Kilometre Array

    NASA Astrophysics Data System (ADS)

    Kharb, P.; Lal, D. V.; Singh, V.; Bagchi, J.; Ishwara Chandra, C. H.; Hota, A.; Konar, C.; Wadadekar, Y.; Shastri, P.; Das, M.; Baliyan, K.; Nath, B. B.; Pandey-Pommier, M.

    2016-12-01

    We present detailed science cases that a large fraction of the Indian AGN community is interested in pursuing with the upcoming Square Kilometre Array (SKA). These interests range from understanding low luminosity active galactic nuclei in the nearby Universe to powerful radio galaxies at high redshifts. Important unresolved science questions in AGN physics are discussed. Ongoing low-frequency surveys with the SKA pathfinder telescope GMRT, are highlighted.

  7. How accurate is [CII] tracing star formation in nearby luminous AGN?

    NASA Astrophysics Data System (ADS)

    Husemann, Bernd

    We propose [CII] line mapping with FIFI-LS to complete observations for 4 nearby luminous AGN as part of our Close AGN Reference Survey (CARS) unobserved in Cycle 4. Our aim is to create a spatially-resolved multi-wavelength dataset to understand whether and how AGN can control star formation in their hosts. We already obtained wide-field optical IFU spectroscopy with MUSE to disentangle emission from HII regions and photoionized gas by the AGN across the galaxies. Currently, there is a high pressure to understand the impact of AGN especially at the peak of cosmic star formation beyond z>2 where measuring the SF is diffcult. The [CII] line at 158microns has become an important diagnostic for SF in high-redshift galaxies with the advent of ALMA. However, the line can be excited by various mechanisms in a multi-phase ISM. In particular the hard radiation field of AGN is a major concern which can only be quantified in nearby galaxies. FIFI-LS aboard SOFIA is currently the only way to perform follow-up observations of FIR emission lines. By uniquily combining MUSE and FIFI-LS we will be able to 1. test if the empirical [CII]-SFR scaling relation hold for luminous nearby AGN, 2. quantifiy any deviation as a function of AGN luminosity, 3. test if the [CII] line kinematics are strongly affected by outflows or trace solely the kinematics of the cold gas disc. Those observations for nearby galaxies with FIFI-LS are crucially needed to establish a reference frame for interpreting high-redshift observation with ALMA at similar physical resolution.

  8. How accurate is [CII] tracing star formation in nearby luminous AGN?

    NASA Astrophysics Data System (ADS)

    Husemann, Bernd

    2015-10-01

    We propose [CII] line mapping with FIFI-LS for a sample of 8 nearby luminous AGN as part of our Close AGN Reference Survey (CARS). Our aim is to create a spatially-resolved multi-wavelength dataset to understand whether and how AGN can control star formation in their hosts. We already obtained wide-field optical IFU spectroscopy with MUSE to disentangle emission from HII regions and photoionized gas by the AGN across the galaxies. Currently, there is a high pressure to understand the impact of AGN especially at the peak of cosmic star formation beyond z>2 where measuring the SF is diffcult. The [CII] line at 158microns has become an important diagnostic for SF in high-redshift galaxies with the advent of ALMA. However, the line can be excited by various mechanisms in a multi-phase ISM. In particular the hard radiation field of AGN is a major concern which can only be quantified in nearby galaxies. FIFI-LS aboard SOFIA is currently the only way to perform follow-up observations of FIR emission lines. By uniquily combining MUSE and FIFI-LS we will be able to 1. test if the empirical [CII]-SFR scaling relation hold for luminous nearby AGN, 2. quantifiy any deviation as a function of AGN luminosity, 3. test if the [CII] line kinematics are strongly affected by outflows or trace solely the kinematics of the cold gas disc. Those observations for nearby galaxies with FIFI-LS are crucially needed to establish a reference frame for interpreting high-redshift observation with ALMA at similar physical resolution.

  9. Results from the NuSTAR Survey of Swift/BAT AGN

    NASA Astrophysics Data System (ADS)

    Balokovic, Mislav; Harrison, Fiona

    2015-08-01

    The Nuclear Spectroscopic Telescope Array (NuSTAR) has enabled studies of the local active galactic nuclei (AGN) to extend into the spectral window above 10 keV with unprecedented spatial resolution and two orders of magnitude better sensitivity than any other instrument operating in that energy range. As a part of its long-term extragalactic program NuSTAR is surveying the nearby population of AGN detected at hard X-ray energies by the Swift Burst Alert Telescope (Swift/BAT). We present results based on 15-25 ks observations of ~150 Swift/BAT AGN surveyed in the first 2.5 years of NuSTAR operation. This sample forms an atlas of the highest quality hard X-ray spectra available to date for a large number of AGN. Assuming a range of hard X-ray spectral models, phenomenological as well as physically motivated, we constrain the main spectral parameters for each source individually and test the applicability of the models on a large sample for the first time. This analysis allows us to determine distributions of the main spectral parameters (spectral index, high-energy cut-off, absorption column, reflection strength, iron line equivalent width) in a well-defined population of nearby AGN. We find that approximately 70% of obscured AGN spectra can be well modeled in terms of simple models used in the literature, while the rest requires careful consideration of more advanced models. We will discuss the implications for the local AGN population, the effects on interpretation of high-redshift AGN observations, and the limitations of the current results.

  10. Ultra-fast outflows (aka UFOs) in AGNs and their relevance for feedback

    NASA Astrophysics Data System (ADS)

    Cappi, Massimo; Tombesi, F.; Giustini, M.; Dadina, M.; Braito, V.; Kaastra, J.; Reeves, J.; Chartas, G.; Gaspari, M.; Vignali, C.; Gofford, J.; Lanzuisi, G.

    2012-09-01

    During the last decade, several observational evidences have been accumulated for the existence of massive, high velocity winds/outflows (aka UFOs) in nearby AGNs and, possibly, distant quasars. I will review here such evidences, present some of the latest results in this field, and discuss the relevance of UFOs for both understanding the physics of accretion/ejection flows on supermassive black holes, and for quantifying the amount of AGN feedback.

  11. AGNfitter: A Bayesian MCMC Approach to Fitting Spectral Energy Distributions of AGNs

    NASA Astrophysics Data System (ADS)

    Calistro Rivera, Gabriela; Lusso, Elisabeta; Hennawi, Joseph F.; Hogg, David W.

    2016-12-01

    We present AGNfitter, a publicly available open-source algorithm implementing a fully Bayesian Markov Chain Monte Carlo method to fit the spectral energy distributions (SEDs) of active galactic nuclei (AGNs) from the sub-millimeter to the UV, allowing one to robustly disentangle the physical processes responsible for their emission. AGNfitter makes use of a large library of theoretical, empirical, and semi-empirical models to characterize both the nuclear and host galaxy emission simultaneously. The model consists of four physical emission components: an accretion disk, a torus of AGN heated dust, stellar populations, and cold dust in star-forming regions. AGNfitter determines the posterior distributions of numerous parameters that govern the physics of AGNs with a fully Bayesian treatment of errors and parameter degeneracies, allowing one to infer integrated luminosities, dust attenuation parameters, stellar masses, and star-formation rates. We tested AGNfitter’s performance on real data by fitting the SEDs of a sample of 714 X-ray selected AGNs from the XMM-COSMOS survey, spectroscopically classified as Type1 (unobscured) and Type2 (obscured) AGNs by their optical-UV emission lines. We find that two independent model parameters, namely the reddening of the accretion disk and the column density of the dusty torus, are good proxies for AGN obscuration, allowing us to develop a strategy for classifying AGNs as Type1 or Type2, based solely on an SED-fitting analysis. Our classification scheme is in excellent agreement with the spectroscopic classification, giving a completeness fraction of ˜ 86 % and ˜ 70 % , and an efficiency of ˜ 80 % and ˜ 77 % , for Type1 and Type2 AGNs, respectively.

  12. The Search for Molecular Outflows in Local Volume AGNs with Herschel-PACS

    NASA Astrophysics Data System (ADS)

    Stone, M.; Veilleux, S.; Meléndez, M.; Sturm, E.; Graciá-Carpio, J.; González-Alfonso, E.

    2016-08-01

    We present the results from a systematic search for galactic-scale, molecular (OH 119 μm) outflows in a sample of 52 Local Volume (d\\lt 50 Mpc) Burst Alert Telescope detected active galactic nuclei (BAT AGNs) with Herschel-PACS. We combine the results from our analysis of the BAT AGNs with the published Herschel/PACS data of 43 nearby (z\\lt 0.3) galaxy mergers, mostly ultra-luminous infrared galaxies (ULIRGs) and QSOs. The objects in our sample of BAT AGNs have, on average, ˜ 10{--}100 times lower AGN luminosities, star formation rates, and stellar masses than those of the ULIRG and QSO samples. OH 119 μm is detected in 42 of our BAT AGN targets. Evidence for molecular outflows (i.e., OH absorption profiles with median velocities more blueshifted than -50 km s-1 and/or blueshifted wings with 84% velocities less than -300 km s-1) is seen in only four BAT AGNs (NGC 7479 is the most convincing case). Evidence for molecular inflows (i.e., OH absorption profiles with median velocities more redshifted than 50 km s-1) is seen in seven objects, although an inverted P-Cygni profile is detected unambiguously in only one object (Circinus). Our data show that both the starburst and AGN contribute to driving OH outflows, but the fastest OH winds require AGNs with quasar-like luminosities. We also confirm that the total absorption strength of OH 119 μm is a good proxy for dust optical depth as it correlates strongly with the 9.7 μm silicate absorption feature, a measure of obscuration originating in both the nuclear torus and host galaxy disk. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  13. Angular Broadening of Intraday Variable AGNs II. Interstellar and Intergalactic Scattering

    DTIC Science & Technology

    2008-01-01

    scattering from any possible intergalactic contribution, we have searched for pulsars within 1 of theAGNs in our sample.We find no pulsars this close to any...of our sources.Given the relatively low density of pulsars on the sky, a significantly larger sample of AGNs would be required in order to make such a...in pulsar dynamic spectra (Hill et al. 2005). We can also use the difference between the scintillating and nonscintillating sources to set

  14. An enhanced fraction of starbursting galaxies among high Eddington ratio AGNs

    NASA Astrophysics Data System (ADS)

    Bernhard, E.; Mullaney, J. R.; Daddi, E.; Ciesla, L.; Schreiber, C.

    2016-07-01

    We investigate the star-forming properties of 1620 X-ray selected active galactic nuclei (AGN) host galaxies as a function of their specific X-ray luminosity (i.e. X-ray luminosity per unit host stellar mass) - a proxy of the Eddington ratio. Our motivation is to determine whether there is any evidence of a suppression of star formation at high Eddington ratios, which may hint towards `AGN feedback' effects. Star formation rates (SFRs) are derived from fits to Herschel-measured far-infrared spectral energy distributions, taking into account any contamination from the AGN. Herschel-undetected AGNs are included via stacking analyses to provide average SFRs in bins of redshift and specific X-ray luminosity (spanning 0.01 lesssim L_X/M_{ast } lesssim 100 L_{{⊙}} M_{{⊙}}^{-1}). After normalizing for the effects of mass and redshift arising from the evolving galaxy main sequence, we find that the SFRs of high specific luminosity AGNs are slightly enhanced compared to their lower specific luminosity counterparts. This suggests that the SFR distribution of AGN hosts changes with specific X-ray luminosity, a result reinforced by our finding of a significantly higher fraction of starbursting hosts among high specific luminosity AGNs compared to that of the general star-forming galaxy population (i.e. 8-10 per cent versus 3 per cent). Contrary to our original motivation, our findings suggest that high specific luminosity AGNs are more likely to reside in galaxies with enhanced levels of star formation.

  15. Differences in Halo-scale Environments between Type 1 and Type 2 AGNs at Low Redshift

    NASA Astrophysics Data System (ADS)

    Jiang, Ning; Wang, Huiyuan; Mo, Houjun; Dong, Xiao-Bo; Wang, Tinggui; Zhou, Hongyan

    2016-12-01

    Using low-redshift (z\\lt 0.09) samples of active galactic nuclei (AGNs), normal galaxies and groups of galaxies selected from the Sloan Digital Sky Survey, we study the environments of Type 1 and Type 2 AGNs, both on small and large scales. Comparisons are made for galaxy samples matched in redshift, r-band luminosity, [O iii] luminosity, and also the position in groups (central or satellite). We find that Type 2 AGNs and normal galaxies reside in similar environments. Type 1 and Type 2 AGNs have similar clustering properties on large scales (≳ 1 {h}-1 {Mpc}), but at scales smaller than 100 {h}-1 {kpc}, Type 2s have significantly more neighbors than Type 1s (3.09 ± 0.69 times more for central AGNs at ≲ 30 {h}-1 {kpc}). These results suggest that Type 1 and Type 2 AGNs are hosted by halos of similar masses, as can also be seen directly from the mass distributions of their host groups (˜ {10}12 {h}-1 {M}⊙ for centrals and ˜ {10}13 {h}-1 {M}⊙ for satellites). Type 2s have significantly more satellites around them, and the distribution of their satellites is also more centrally concentrated. The host galaxies of both types of AGNs have similar optical properties, but their infrared colors are significantly different. Our results suggest that the simple unified model based solely on torus orientation is not sufficient, but that galaxy interactions in dark matter halos must have played an important role in the formation of the dust structure, which obscures AGNs.

  16. Star formation in AGNs at the hundred parsec scale using MIR high-resolution images

    NASA Astrophysics Data System (ADS)

    Ruschel-Dutra, Daniel; Rodríguez Espinosa, José Miguel; González Martín, Omaira; Pastoriza, Miriani; Riffel, Rogério

    2017-04-01

    It has been well established in the past decades that the central black hole masses of galaxies correlate with dynamical properties of their harbouring bulges. This notion begs the question of whether there are causal connections between the active galactic nucleus (AGN) and its immediate vicinity in the host galaxy. In this paper, we analyse the presence of circumnuclear star formation in a sample of 15 AGN using mid-infrared observations. The data consist of a set of 11.3 μm polycyclic aromatic hydrocarbon emission and reference continuum images, taken with ground-based telescopes, with sub-arcsecond resolution. By comparing our star formation estimates with AGN accretion rates, derived from X-ray luminosities, we investigate the validity of theoretical predictions for the AGN-starburst connection. Our main results are: (i) circumnuclear star formation is found, at distances as low as tens of parsecs from the nucleus, in nearly half of our sample (7/15); (ii) star formation luminosities are correlated with the bolometric luminosity of the AGN (LAGN) only for objects with LAGN ≥ 1042 erg s-1; (iii) low-luminosity AGNs (LAGN < 1042 erg s-1) seem to have starburst luminosities far greater than their bolometric luminosities.

  17. Constraining the UV emissivity of AGN throughout cosmic time via X-ray surveys

    NASA Astrophysics Data System (ADS)

    Ricci, Federica; Marchesi, Stefano; Shankar, Francesco; La Franca, Fabio; Civano, Francesca

    2017-02-01

    The cosmological process of hydrogen (H I) reionization in the intergalactic medium is thought to be driven by UV photons emitted by star-forming galaxies and ionizing active galactic nuclei (AGN). The contribution of quasars (QSOs) to H I reionization at z > 4 has been traditionally believed to be quite modest. However, this view has been recently challenged by new estimates of a higher faint-end UV luminosity function (LF). To set firmer constraints on the emissivity of AGN at z < 6, we here make use of complete X-ray-selected samples including deep Chandra and new Cosmic Evolution Survey data, capable to efficiently measure the 1 Ryd comoving AGN emissivity up to z ∼ 5-6 and down to 5 mag fainter than probed by current optical surveys, without any luminosity extrapolation. We find good agreement between the logNH ≲ 21-22 cm-2 X-ray LF and the optically selected QSO LF at all redshifts for M1450 ≤ -23. The full range of the logNH ≲ 21-22 cm-2 LF (M1450 ≤ -17) was then used to quantify the contribution of AGN to the critical value of photon budget needed to keep the Universe ionized. We find that the contribution of ionizing AGN at z = 6 is as small as 1-7 per cent, and very unlikely to be greater than 30 per cent, thus excluding an AGN-dominated reionization scenario.

  18. Dusting off the star formation history of AGN hosts with SHARDS

    NASA Astrophysics Data System (ADS)

    Hernán-Caballero, Antonio

    2015-03-01

    Recent works show that the restframe colours of X-ray selected AGN host galaxies at z~1 are no different from those of inactive galaxies once stellar mass selection effects are taken into account. However, there is a clear deficit of AGN among quiescent galaxies, and the average star formation rates of AGN hosts are comparable or higher than those of inactive star-forming galaxies. These apparently contradictory findings could be a consequence of higher extinction in star-forming AGN hosts compensating for their younger stellar populations in observed colours. In this talk I will present a new method of extinction correction that breaks the degeneracy with stellar age and metallicity by comparing the restframe U-V colour with measurements of the Dn(4000) index on intermediate band photospectra from SHARDS. I'll show that the distribution of extinction corrected U-V colours and Dn(4000) for AGN hosts at z<1 is significantly different from that of comparison samples of inactive galaxies, with a clear deficit of AGN in intrinsic red galaxies and a higher prevalence among those with intermediate age stellar populations.

  19. ISO Key Project: Exploring the Full Range of Quasar/AGN Properties

    NASA Technical Reports Server (NTRS)

    Wilkes, B.

    2001-01-01

    The origin of the infrared emission in Active Galactic Nuclei (AGN), whose strength is comparable to the optical/ultra-violet (OUV) emission, is generally thought to be a combination of thermal emission from dust and non-thermal, synchrotron emission. Although data are sparse, particularly in the far-infrared, the broad wavelength range of this emission suggests a wide range of temperatures and a combination of AGN and starburst heating mechanisms. The strength of the non-thermal emission is expected to be related to the radio emission. While this scenario is well-established, basic questions, such as the spatial and temperature distribution of the dust, the relative importance of AGN and starburst heating, and the significance of the non-thermal contribution, remain largely undetermined. The wide wavelength range of the Infrared Space Observatory (ISO) combined with its arcmin spatial resolution and increased sensitivity facilitated the observation of a larger subset of the AGN population than previously covered, allowing these questions to be investigated in more detail. This paper will review the spectral energy distributions (SED) of AGN with particular emphasis on the infrared emission and on ISO contributions to our knowledge. Preliminary results from ISO observations of X-ray selected and high-redshift AGN will be described.

  20. Role of feedback in AGN-host coevolution: A study from partially obscured active galactic nuclei

    NASA Astrophysics Data System (ADS)

    Wang, J.

    2015-05-01

    Partially obscured AGNs within a redshift range z = 0.011 ∼ 0.256 are used to re-study the role of feedback in the AGN-host coevolution issue in terms of their [OIII] λ 5007 emission line profile. The spectra of these objects enable us to determine the AGN's accretion properties directly from their broad H α emission. This is essential for getting rid of the "circular reasoning" in our previous study of narrow emission-line galaxies, in which the [OIII] emission line was used not only as a proxy of AGN's bolometric luminosity, but also as a diagnostic of outflow. In addition, the measurement of Dn (4000) index is improved by removing an underlying AGN's continuum according to the corresponding broad H α emission. With these improvements, we confirm and reinforce the correlation between L /LEdd and stellar population age. More important is that this correlation is found to be related to both [OIII] line blue asymmetry and bulk blueshift velocity, which suggests a linkage between SMBH growth and host star formation through the feedback process. The current sample of partially obscured AGNs shows that the composite galaxies have younger host stellar population, higher Eddington ratio, less significant [OIII] blue wing and smaller bulk [OIII] line shift than do the Seyfert galaxies.

  1. The small observed scale of AGN-driven outflows, and inside-out disc quenching

    NASA Astrophysics Data System (ADS)

    Zubovas, Kastytis; King, Andrew

    2016-11-01

    Observations of massive outflows with detectable central active galactic nuclei (AGN) typically find them within radii ≲10 kpc. We show that this apparent size restriction is a natural result of AGN driving if this process injects total energy only of the order of the gas binding energy to the outflow, and the AGN varies over time (`flickers') as suggested in recent work. After the end of all AGN activity, the outflow continues to expand to larger radii, powered by the thermal expansion of the remnant-shocked AGN wind. We suggest that on average, outflows should be detected further from the nucleus in more massive galaxies. In massive gas-rich galaxies, these could be several tens of kpc in radius. We also consider the effect that pressure of such outflows has on a galaxy disc. In moderately gas-rich discs, with gas-to-baryon fraction <0.2, the outflow may induce star formation significant enough to be distinguished from quiescent by an apparently different normalization of the Kennicutt-Schmidt law. The star formation enhancement is probably stronger in the outskirts of galaxy discs, so coasting outflows might be detected by their effects upon the disc even after the driving AGN has shut off. We compare our results to the recent inference of inside-out quenching of star formation in galaxy discs.

  2. The impact of AGN feedback and baryonic cooling on galaxy clusters as gravitational lenses

    NASA Astrophysics Data System (ADS)

    Mead, James M. G.; King, Lindsay J.; Sijacki, Debora; Leonard, Adrienne; Puchwein, Ewald; McCarthy, Ian G.

    2010-07-01

    We investigate the impact of active galactic nucleus (AGN) feedback on the gravitational lensing properties of a sample of galaxy clusters with masses in the range 1014-1015 Msolar, using state-of-the-art simulations. Adopting a ray-tracing algorithm, we compute the cross-section of giant arcs from clusters simulated with dark matter (DM) only physics, DM plus gas with cooling and star formation (CSF) and DM plus gas with cooling, star formation and AGN feedback (CSFBH). Once AGN feedback is included, baryonic physics boosts the strong-lensing cross-section by much less than previously estimated using clusters simulated with only CSF. For a cluster with a virial mass of 7.4 × 1014 Msolar, inclusion of baryonic physics without feedback can boost the cross-section by as much as a factor of 3, in agreement with previous studies, whereas once AGN feedback is included this maximal figure falls to a factor of 2 at most. Typically, clusters simulated with DM and CSFBH physics have similar cross-sections for the production of giant arcs. We also investigate how baryonic physics affects the weak-lensing properties of the simulated clusters by fitting NFW profiles to synthetic weak-lensing data sets using a Markov Chain Monte Carlo approach, and by performing non-parametric mass reconstructions. Without the inclusion of AGN feedback, measured concentration parameters can be much larger than those obtained with AGN feedback, which are similar to the DM-only case.

  3. The detection of Fermi AGN above 100 GeV using clustering analysis

    NASA Astrophysics Data System (ADS)

    Armstrong, Thomas; Brown, Anthony M.; Chadwick, Paula M.; Nolan, S. J.

    2015-09-01

    The density-based clustering algorithm DBSCAN has been applied to the Fermi Large Area Telescope (LAT) data set of Eγ ≥ 100 GeV events with |b| > 10°, in order to search for new very high energy (VHE) γ-ray sources. The clustering analysis returned 49 clusters, of which 21 correspond to already known VHE-emitting active galactic nuclei (AGN) within the TeVCat catalogue and a further 11 were found to be significant in a full Fermi analysis. Of these, two are previously detected Fermi VHE AGN, and nine represent new VHE sources consisting of six BL Lac objects, one blazar of unknown type and two unassociated sources. Comparing these, along with the VHE AGN RBS 0679 and RBS 0970 previously detected with Fermi-LAT, to the current populations of AGN detected with ground-based instruments and Fermi suggests that the VHE-emitting AGN discovered in this study are very similar to the TeVCat AGN and therefore further observations with ground-based imaging atmospheric Cherenkov telescopes are recommended.

  4. A statistical study of H i gas in nearby narrow-line AGN-hosting galaxies

    SciTech Connect

    Zhu, Yi-Nan; Wu, Hong E-mail: hwu@bao.ac.cn

    2015-01-01

    As a quenching mechanism, active galactic nucleus (AGN) feedback could suppress on going star formation in host galaxies. On the basis of a sample of galaxies selected from the Arecibo Legacy Fast ALFA (ALFALFA) H i survey, the dependence of the H i mass (M{sub H} {sub i}), stellar mass (M{sub *}), and H i-to-stellar mass ratio (M{sub H} {sub i}/M{sub *}) on various tracers of AGN activity are presented and analyzed in this paper. Almost all the AGN hostings in this sample are gas-rich galaxies, and there is not any evidence to indicate that the AGN activity could increase or decrease either M{sub H} {sub i} or M{sub H} {sub i}/M{sub *}. The position of the cold neutral gas cannot be fixed accurately based only on available H i data, due to the large beam size of ALFALFA survey. In addition, even though AGN hostings are more easily detected by an H i survey compared with absorption line galaxies, these two types of galaxies show similar star formation history. If an AGN hosting would ultimately evolve into an old red galaxy with low cold gas, then when and how the gas has been exhausted must be solved by future hypotheses and observations.

  5. Non-immunoglobulin A mesangial immune complex glomerulonephritis in kidney transplants.

    PubMed

    Giannico, Giovanna A; Arnold, Shanna; Langone, Anthony; Schaefer, Heidi; Helderman, J Harold; Shaffer, David; Fogo, Agnes B

    2015-10-01

    We have observed a predominantly mesangial non-immunoglobulin A immune complex mesangial glomerulopathy (MG) in renal transplants with mesangial deposits by immunofluorescence and electron microscopy. Clinicopathological features of 28 patients with MG were analyzed and compared with 28 transplant controls, matched for age, sex, ethnicity, donor type, estimated glomerular filtration rate, and interval from transplant to biopsy. Indications for biopsy in the MG group were allograft dysfunction in 64%, allograft dysfunction/proteinuria in 29%, and proteinuria in 7%. Biopsy indications in controls were allograft dysfunction (61%), allograft dysfunction/proteinuria (18%), proteinuria (14%), and delayed graft function (7%). Most MG cases had mild mesangial hypercellularity with endocapillary proliferation in 2 and crescents in 2 without fibrinoid necrosis. Immunoglobulin M-dominant deposits were present in 83%, and immunoglobulin G was dominant in 17% with mesangial deposits in 93% of cases by electron microscopy. Compared with controls, MG had higher Banff interstitial inflammation score (i) (P = .036) and was associated with concurrent acute T-cell-mediated rejection (P = .023), but not with acute or chronic antibody-mediated rejection. MG patients and controls had similar prevalence of polyomavirus nephropathy and Epstein-Barr virus infection. At follow-up, most MG patients had stable estimated glomerular filtration rate with no or stable proteinuria. Disease-specific graft survival was not different in MG versus controls. We conclude that, in view of the apparent self-limited nature of this lesion, additional treatment may not be required in these patients. Awareness of this lesion may thus spare patients unwarranted further intervention.

  6. The Emission Line AGN Census: Biases of Line Ratio Selection, and Uniform Black Hole Accretion Regardless of Galaxy Mass

    NASA Astrophysics Data System (ADS)

    Trump, Jonathan R.; Zeimann, Gregory; Juneau, Stephanie; Sun, Mouyuan; Luck, Cuyler

    2015-01-01

    Optical emission line ratios offer a powerful tool to reveal accretion onto supermassive black holes, with the ability to find both unobscured and obscured active galactic nuclei (AGNs) in extraordinarily large galaxy samples (like the SDSS). I will demonstrate, however, that classic line ratio selection techniques significantly underestimate the AGN fraction by a factor of >10 in low-mass and star-forming galaxies. Previous conclusions that AGNs require massive green-valley hosts are purely a result of this "star formation dilution" bias. Careful treatment of the biases reveals that AGN accretion is uniform across star-forming galaxies of any stellar mass, similar to the results of bias-corrected X-ray AGN studies. This has dramatic implications for AGN feedback in dwarf galaxies and constraints on the black hole seed population.

  7. Rituximab Treatment for PR3-ANCA-Positive Membranoproliferative Glomerulonephritis Associated with Adult-Onset Periodic Fever Syndrome

    PubMed Central

    Hamano, Yoshitomo; Yoshizawa, Hiromichi; Sugase, Taro; Miki, Takuya; Ohtani, Naoko; Hanawa, Shiho; Takeshima, Eri; Morishita, Yoshiyuki; Saito, Osamu; Takemoto, Fumi; Muto, Shigeaki; Yumura, Wako; Kusano, Eiji

    2012-01-01

    We report the case of a 36-year-old Japanese woman with nephrotic syndrome due to membranoproliferative glomerulonephritis (MPGN) Type I diagnosed after a 5-year history of periodic fever syndrome (PFS). Hypocomplementemia and elevation of anti-proteinase 3 anti-neutrophil cytoplasmic autoantibody (PR3-ANCA) were observed. HIV, and hepatitis B and C serology were negative. Nephrotic syndrome and periodic fever did not respond to oral steroid and intravenous steroid pulse therapies combined with cyclosporine, dipyridamole, warfarin and losartan. We tried immunotherapy using rituximab, a human-mouse chimeric monoclonal antibody directed against the CD20 antigen on mature B cells. This therapeutic approach led to improvement of renal function and remission of nephrotic syndrome and hypocomplementemia. However, it did not have a beneficial effect on periodic fever. Suspecting adult-onset hereditary PFS, we analyzed her genetic alteration of MEFV and TNFRSF1A genes. A rare genotype in intron 6 of TNFRSF1A was revealed. The etiological relationship between periodic fever and MPGN is discussed. Rituximab is a hopeful choice of induction therapy for refractory MPGN. PMID:23197963

  8. Altered long non-coding RNA expression profile in patients with IgA-negative mesangial proliferative glomerulonephritis.

    PubMed

    Sui, Weiguo; Li, Huan; Ou, Minglin; Tang, Dong'e; Dai, Yong

    2012-07-01

    Mesangial proliferative glomerulonephritis (MsPGN) is one of the most common immune-mediated renal diseases. The mesangium is expanded and hypercellular, immuno-globulin deposits can be found in the mesangium, but the mechanism underlying its cause remains largely unclear. There is a large amount of evidence suggesting that long ﹥200 nucleotide) non-coding RNAs (lncRNA) have important regulatory functions in the epigenetic control of gene expression. Multiple lines of evidence increasingly link mutations and dysregulations of lncRNAs to a diverse number of human diseases. Through microarray expression analysis, tests show that thousands of lncRNAs and protein-coding genes are significantly differentially expressed in IgA-negative MsPGN. Some lncRNAs and their neighboring protein-coding genes are closely related and are cooperatively expressed. This may be part of a potential regulatory mechanism. The malfunction of regulation in the network of lncRNAs may be a possible mechanism for the development of IgA-negative MsPGN. Our observations suggest that some lncRNAs are closely related to IgA-negative MsPGN and may be playing an important role in this disease.

  9. Anemia with chronic renal disorder and disrupted metabolism of erythropoietin in ICR-derived glomerulonephritis (ICGN) mice.

    PubMed

    Yamaguchi-Yamada, Misuzu; Manabe, Noboru; Uchio-Yamada, Kozue; Akashi, Naotsugu; Goto, Yasufumi; Miyamoto, Youhei; Nagao, Masaya; Yamamoto, Yoshie; Ogura, Atsuo; Miyamoto, Hajime

    2004-04-01

    The ICR-derived glomerulonephritis (ICGN) mouse, a new inbred mouse strain with a hereditary nephrotic syndrome, is considered to be a good model of human idiopathic nephrotic syndrome and notably exhibits proteinuria and hypoproteinemia from the neonatal stage. In chronic renal disorder (CRD), anemia is a major subsequent symptom (renal anemia). The precise cause of renal anemia remains unclear, primarily owing to the lack of appropriate spontaneous animal models for CRD. To establish adequate animal models for anemia with CRD, we examined the hematological-biochemical properties and histopathological characteristics. With the deterioration of renal function, ICGN mice developed a normochromic and normocytic anemia, and exhibited normochromic and microcytic at the terminal stage. The expression of erythropoietin (EPO) mRNA both in the kidneys and liver and the EPO leak into the urine were observed in ICGN mice, indicating a disrupted metabolism of EPO in ICGN mice. In addition, a lack of iron induced by the hemolysis in the spleen and the leak of transferrin into urine as proteinuria aggravated the anemic condition. In conclusion, the ICGN mouse is a good model for anemia with CRD.

  10. Mucosal Tolerance Induced by an Immunodominant Peptide from Rat α3(IV)NC1 in Established Experimental Autoimmune Glomerulonephritis

    PubMed Central

    Reynolds, John; Abbott, Danielle S.; Karegli, Julieta; Evans, David J.; Pusey, Charles D.

    2009-01-01

    Experimental autoimmune glomerulonephritis (EAG), an animal model of Goodpasture’s disease, can be induced in Wistar Kyoto (WKY) rats by immunization with the noncollagenous domain of the α 3 chain of type IV collagen, α3(IV)NC1. Recent studies have identified an immunodominant peptide, pCol (24-38), from the N-terminus of rat α3(IV)NC1; this peptide contains the major B- and T-cell epitopes in EAG and can induce crescentic nephritis. In this study, we investigated the mechanisms of mucosal tolerance in EAG by examining the effects of the nasal administration of this peptide after the onset of disease. A dose-dependent effect was observed: a dose of 300 μg had no effect, a dose of 1000 μg resulted in a moderate reduction in EAG severity, and a dose of 3000 μg produced a marked reduction in EAG severity accompanied by diminished antigen-specific, T-cell proliferative responses. These results demonstrate that mucosal tolerance in EAG can be induced by nasal administration of an immunodominant peptide from the N-terminus of α3(IV)NC1 and should be of value in designing new therapeutic strategies for patients with Goodpasture’s disease and other autoimmune disorders. PMID:19406992

  11. C1q nephropathy and isolated CD59 deficiency manifesting as necrotizing crescentic glomerulonephritis: A rare association of two diseases.

    PubMed

    Gupta, Ruchika; Sharma, Alok; Agarwal, Sanjay K; Dinda, Amit K

    2015-11-01

    C1q nephropathy is a recently described clinico-pathologic entity with a variable clinical presentation and pathology. Crescentic glomerulonephritis (GN) has been reported in only two patients in the available literature. CD59 deficiency, along with lack of CD55, is responsible for paroxysmal nocturnal hemoglobinuria (PNH). Few cases of isolated CD59 deficiency have been described with PNH-like features. A middle-aged adult male presented with rapidly progressive renal failure. Serological investigations were negative. A renal biopsy revealed necrotizing crescentic GN with rupture of Bowman's capsule. Immunofluorescence on the frozen sections showed dominant mesangial deposits of C1q along with IgM. Hematological work-up of the patient revealed isolated CD59 deficiency. Hence, a final diagnosis of C1q nephropathy and CD59 deficiency manifesting as crescentic GN and hemolytic anemia was made. The co-existence of two rare disorders, C1q nephropathy and CD59 deficiency, in a patient with necrotizing crescentic GN is described for the first time to the best of our knowledge. The pathogenetic link of these two entities with the clinical manifestation requires further study.

  12. Association between rapidly progressive glomerulonephritis and the properdin factor BfF and different HLA-D region products.

    PubMed

    Müller, G A; Gebhardt, M; Kömpf, J; Baldwin, W M; Ziegenhagen, D; Bohle, A

    1984-01-01

    Frequencies of the HLA antigens ABC, DR and MT, as well as of the properdin factor alleles were determined in 24 unrelated patients presenting with immune complex mediated idiopathic rapidly progressive glomerulonephritis (RPGN) type II. As in Goodpasture syndrome (RPGN type I with pulmonary hemorrhage), a significant association with the B-cell alloantigen HLA-DR 2 was demonstrated (relative risk for HLA-DR 2 positive individuals was 3.54; P less than 0.01). In addition a marked increase of the HLA specificity MT 3 was shown, which is supposed to belong to an antigen system of a second HLA-D region locus. The highest relative risk of 14.67 (P less than 0.00001), however, was calculated for all patients carrying the BfF phenotype. Increased numbers of patients positive for HLA-DR 2 and -MT 3, as well as BfF suggested immune response genes or disease-related mutations on different haplotypes responsible for a MHC (major histocompatibility complex) associated predisposition of RPGN type II.

  13. CD4+ T Cell Fate in Glomerulonephritis: A Tale of Th1, Th17, and Novel Treg Subtypes

    PubMed Central

    2016-01-01

    Multiple studies have identified CD4+ T cells as central players of glomerulonephritis (GN). Cells of the Th1 and Th17 responses cause renal tissue damage, while Tregs mediate protection. Recently, a high degree of plasticity among these T cell lineages was proposed. During inflammation, Th17 cells were shown to have the potential of transdifferentiation into Th1, Th2, or alternatively anti-inflammatory Tr1 cells. Currently available data from studies in GN, however, do not indicate relevant Th17 to Th1 or Th2 conversion, leaving the Th17 cell fate enigmatic. Tregs, on the other hand, were speculated to transdifferentiate into Th17 cells. Again, data from GN do not support this concept. Rather, it seems that previously unrecognized subspecialized effector Treg lineages exist. These include Th1 specific Treg1 as well as Th17 directed Treg17 cells. Furthermore, a bifunctional Treg subpopulation was recently identified in GN, which secrets IL-17 and coexpresses Foxp3 together with the Th17 characteristic transcription factor RORγt. Similarities between these different and highly specialized effector Treg subpopulations with the corresponding T helper effector cell lineages might have resulted in previous misinterpretation as Treg transdifferentiation. In summary, Th17 cells have a relatively stable phenotype during GN, while, in the case of Tregs, currently available data suggest lineage heterogeneity rather than plasticity. PMID:27974866

  14. EDDINGTON RATIO DISTRIBUTION OF X-RAY-SELECTED BROAD-LINE AGNs AT 1.0 < z < 2.2

    SciTech Connect

    Suh, Hyewon; Hasinger, Günther; Steinhardt, Charles; Silverman, John D.; Schramm, Malte

    2015-12-20

    We investigate the Eddington ratio distribution of X-ray-selected broad-line active galactic nuclei (AGNs) in the redshift range 1.0 < z < 2.2, where the number density of AGNs peaks. Combining the optical and Subaru/Fiber Multi Object Spectrograph near-infrared spectroscopy, we estimate black hole masses for broad-line AGNs in the Chandra Deep Field South (CDF-S), Extended Chandra Deep Field South (E-CDF-S), and the XMM-Newton Lockman Hole (XMM-LH) surveys. AGNs with similar black hole masses show a broad range of AGN bolometric luminosities, which are calculated from X-ray luminosities, indicating that the accretion rate of black holes is widely distributed. We find a substantial fraction of massive black holes accreting significantly below the Eddington limit at z ≲ 2, in contrast to what is generally found for luminous AGNs at high redshift. Our analysis of observational selection biases indicates that the “AGN cosmic downsizing” phenomenon can be simply explained by the strong evolution of the comoving number density at the bright end of the AGN luminosity function, together with the corresponding selection effects. However, one might need to consider a correlation between the AGN luminosity and the accretion rate of black holes, in which luminous AGNs have higher Eddington ratios than low-luminosity AGNs, in order to understand the relatively small fraction of low-luminosity AGNs with high accretion rates in this epoch. Therefore, the observed downsizing trend could be interpreted as massive black holes with low accretion rates, which are relatively fainter than less-massive black holes with efficient accretion.

  15. Mid-Infrared Spectroscopy of the Brightest Type 2 AGN in the SDSS

    NASA Astrophysics Data System (ADS)

    Heckman, Timothy; Armus, Lee; Martins, Lucimara; Tremonti, Christy

    2006-05-01

    We propose to use the IRS on Spitzer to observe a complete and well-defined sample of the 20 brightest Type 2 (obscured) Active Galactic Nuclei (AGN) in the Sloan Digital Sky Survey (SDSS). They are selected from a sample of over 100,000 SDSS AGN on the basis of the flux in the [OIII]5007 emission-line. The full SDSS sample has been used to study the properties of local AGN and their host galaxies with unmatched statistical precision. The results imply that there is on-going co-evolution of black holes and galaxy bulges in the present universe (albeit at lower mass scales than in the past). Given the sensitivity of optical observations to even modest amounts of dust extinction, it is imperative to determine whether mid-IR and optical observations of these objects are consistent. The general goal of the proposal is to produce a set of high-quality mid-IR spectra for a complete sample of the brightest SDSS Type 2 AGN. The specific goals are: 1) To compare measurements of the AGN luminosity derived from the high-ionization mid-IR emission-lines to those derived from similar optical emission-lines. 2) To compare estimates of the relative energetic significance of black hole accretion and star formation in AGN host galaxies derived from optical data to those derived from mid-IR spectroscopy. These two goals address the following two questions: 1) How well can the luminosity of Type 2 SDSS AGN be estimated from optical spectra alone? 2) Can the coupled growth of black holes and galaxy bulges in the low-z universe be adequately quantified from optical data alone? Using the IRS to observe a complete sub-set of the 100,000 Type 2 SDSS AGN is essential to understand the degree to which the SDSS data provide a fair picture of the low-redshift AGN phenomenon. These data will beautifully complement existing IRS surveys of IR-selected AGN.

  16. Early Results from Swift AGN and Cluster Survey

    NASA Astrophysics Data System (ADS)

    Dai, Xinyu; Griffin, Rhiannon; Nugent, Jenna; Kochanek, Christopher S.; Bregman, Joel N.

    2016-04-01

    The Swift AGN and Cluster Survey (SACS) uses 125 deg^2 of Swift X-ray Telescope serendipitous fields with variable depths surrounding gamma-ray bursts to provide a medium depth (4 × 10^-15 erg cm^-2 s^-1) and area survey filling the gap between deep, narrow Chandra/XMM-Newton surveys and wide, shallow ROSAT surveys. Here, we present the first two papers in a series of publications for SACS. In the first paper, we introduce our method and catalog of 22,563 point sources and 442 extended sources. SACS provides excellent constraints on the AGN and cluster number counts at the bright end with negligible uncertainties due to cosmic variance, and these constraints are consistent with previous measurements. The depth and areal coverage of SACS is well suited for galaxy cluster surveys outside the local universe, reaching z > 1 for massive clusters. In the second paper, we use SDSS DR8 data to study the 203 extended SACS sources that are located within the SDSS footprint. We search for galaxy over-densities in 3-D space using SDSS galaxies and their photometric redshifts near the Swift galaxy cluster candidates. We find 103 Swift clusters with a > 3σ over-density. The remaining targets are potentially located at higher redshifts and require deeper optical follow-up observations for confirmations as galaxy clusters. We present a series of cluster properties including the redshift, BCG magnitude, BCG-to-X-ray center offset, optical richness, X-ray luminosity and red sequences. We compare the observed redshift distribution of the sample with a theoretical model, and find that our sample is complete for z ≤ 0.3 and 80% complete for z ≤ 0.4, consistent with the survey depth of SDSS. These analysis results suggest that our Swift cluster selection algorithm presented in our first paper has yielded a statistically well-defined cluster sample for further studying cluster evolution and cosmology. In the end, we will discuss our ongoing optical identification of z>0.5 cluster

  17. Theoretical and Observational Studies of the Central Engines of AGN

    NASA Technical Reports Server (NTRS)

    Sivron, Ran

    1995-01-01

    In Active Galactic Nuclei (AGN) the luminosity is so intense that the effect of radiation pressure on a particle may exceed the gravitational attraction. It was shown that when such luminosities are reached, relatively cold (not completely ionized) thermal matter clouds may form in the central engines of AGN, where most of the luminosity originates. We show that the spectrum of emission from cold clouds embedded in hot relativistic matter is similar to the observed spectrum. We also show that within the hot relativistic matter, cold matter moves faster than the speed of sound or the Alfven speed, and shocks form. The shocks provide a mechanism by which a localized perturbation can propagate throughout the central engine. The shocked matter can emit the observed luminosity, and can explain the flux and spectral variability. It may also provide an efficient mechanism for the outward transfer of angular momentum and provide the outward flow of winds. With observations from X-ray satellites, emission features from the cold and hot matter may be revealed. Our analysis of X-ray data from the Seyfert 1 galaxy MCG - 6-30-15 over five years using detectors on the Ginga and Rosat satellites, revealed some interesting variable features. A source with hot matter emits non-thermal radiation which is Compton reflected from cold matter and then absorbed by warm (partially ionized) absorbing matter in the first model, which can be fit to the data if both the cold and warm absorbers are near the central engine. An alternative model in which the emission from the hot matter is partially covered by very warm matter (in which all elements except Iron are mostly ionized) is also successful. In this model the cold and warm matter may be at distances of up to 100 times the size of the central engine, well within the region where broad optical lines are produced. The flux variability is more naturally explained by the second model. Our results support the existence of cold matter in, or

  18. Acute Bronchitis

    MedlinePlus

    ... can also cause acute bronchitis. To diagnose acute bronchitis, your health care provider will ask about your symptoms and listen to your breathing. You may also have other tests. Treatments include rest, fluids, and aspirin (for adults) or ...

  19. Impact of AGN and stellar feedback on the gas of a simulated z~2 star-forming galaxy

    NASA Astrophysics Data System (ADS)

    Roos, Orianne; Bournaud, Frédéric; Juneau, Stephanie; Gabor, Jared

    2015-08-01

    With high-resolution simulations of star-forming disk galaxies at high redshift, we study the effects of combined AGN and stellar feedback models on the gas of the host-galaxy. AGN feedback is modeled using a standard thermal recipe of feedback (gas is heated and pushed away) plus a post-processing method to compute AGN ionization. We first consider AGN feedback only and show that, even though the AGN generates powerful outflows, the effects of AGN feedback on star formation is relatively weak on time-scales up to a few 100s of Myrs, even when long-range radiative feedback is accounted for. Furthermore, as the combination of stellar feedback models generates outflows that are more powerful than the sum of the models taken separately, we check whether combined AGN and stellar feedback also couple non-linearly. We then include several stellar feedback sources on top of AGN feedback, such as young stars creating HII regions through radiative pressure and supernovae releasing thermal and kinetic energy in the ISM. We follow their impact on the gas of high-resolution simulations and study the coupling between the different sources of outflows (AGN, young stars, supernovae) , which could produce very fast outflows, with important outflow rates. How do these feedback-driven winds affect the host? What is the amount of expelled gas? What is its density and temperature and what is the consequence for in place and future star formation? Can such outflows change the distribution of existing stars?

  20. An Antifungal Exo-α-1,3-Glucanase (AGN13.1) from the Biocontrol Fungus Trichoderma harzianum

    PubMed Central

    Ait-Lahsen, Hassane; Soler, Andrés; Rey, Manuel; de la Cruz, Jesús; Monte, Enrique; Llobell, Antonio

    2001-01-01

    Trichoderma harzianum secretes α-1,3-glucanases when it is grown on polysaccharides, fungal cell walls, or autoclaved mycelium as a carbon source (simulated antagonistic conditions). We have purified and characterized one of these enzymes, named AGN13.1. The enzyme was monomeric and slightly basic. AGN13.1 was an exo-type α-1,3-glucanase and showed lytic and antifungal activity against fungal plant pathogens. Northern and Western analyses indicated that AGN13.1 is induced by conditions that simulated antagonism. We propose that AGN13.1 contributes to the antagonistic response of T. harzianum. PMID:11722942

  1. Management of acute renal failure in the elderly. Treatment options.

    PubMed

    Mandal, A K; Baig, M; Koutoubi, Z

    1996-10-01

    urine output and urinary sodium excretion, and a rapid decrease in blood urea nitrogen, constitutes strong evidence for prerenal ARF. However, these indices are unreliable when prerenal ARF has progressed to ATN or when ARF has an obstructive pattern to begin with. In all cases of ARF, especially in elderly men, urinary tract obstruction should be suspected unless the history is otherwise clear cut. Ultrasound of the kidneys and bladder is a simple, non-invasive and meaningful test that can be used to rule out obstructive causes of ARF. If obstruction is the cause of ARF, ultrasound will be positive; in contrast, urinary obstruction is very unlikely if ultrasound findings are normal in a patient who has been oliguric or anuric for 48 hours or more. Simila