Elderly-onset anticentromere antibody-positive pulmonary-renal syndrome: report of an autopsy case]

We report an autopsy case of elderly-onset anticentromere antibody-positive pulmonary-renal syndrome. An 84-year-old woman was admitted to our hospital with complaints of leg edema and general malaise. Neither skin rush nor arthritis was seen. Because of hematuria, proteinuria with various casts, renal dysfunction and anemia, a clinically diagnosis of rapidly progressive glomerulonephritis was made. Slight pulmonary hypertension was observed in ultrasonic cardiography. Hypocomplementemia was not seen. Tests for MPO- and PR 3-anti-neutrophil cytoplasmic antibodies and anti-glomerular basement membrane antibody were negative, but a high titer of antinuclear antibody with a discrete speckled pattern on immunofluorescent staining was disclosed. Results for anticentromere antibody and anti-Ki antibody were positive, but for anti-Sm antibody and anti-double stranded DNA antibody were both negative. She did not present any clinical features of systemic sclerosis or CREST syndrome. Subsequently, prednisolone was administered, but pulmonary alveolar hemorrhage occurred and the patient died of acute respiratory failure caused by massive pulmonary hemorrhage. Autopsy revealed crescentic glomerulonephritis including glomerular capillaritis and pulmonary capillaritis with positive granular deposits of immunoglobulins and compliment on the glomerular and pulmonary capillary walls. Immunologically mediated crescentic glomerulonephritis and pulmonary capillaritis was then diagnosed histopathologically. The main pathological feature of the case was small-vessel vasculitis with immune-complex deposition. Although this case did not fulfill the clinical criteria for systemic lupus erythematosus (SLE), its histological features resembled those of lupus nephritis and acute lupus pneumonitis. We speculated that anticentromere antibody-positive pulmonary-renal syndrome without any other symptoms or signs of connective tissue disease, such as our case, is a clinical entity distinct from typical SLE or CREST syndrome.     

Rapid and prominent up-regulation of high-affinity receptor for immunoglobulin G (Fc gamma RI) by cross-linking of beta 2 integrins on polymorphonuclear leukocytes

Receptors for the Fc region (FcR) of immunoglobulin (Ig)G play essential roles in effector functions of polymorphonuclear leukocytes (PMNs) including the antibody-mediated clearance of microbes. In contrast to the constitutive expression of the low-affinity receptors for IgG (Fc gamma RII [CD32] and Fc gamma RIII [CD16]), the high-affinity receptor Fc gamma RI (CD64) is barely detectable on unactivated PMNs. CD64 expression is induced in a slow kinetic manner by interferon (IFN)-gamma and granulocyte colony-stimulating factor (G-CSF) after 12 to 24 hours of exposure to these agents. We found that the cross-linking of CD11b as well as of CD18 induced comparable rapid increases in CD64 expression on the surface of PMNs, occurring within 15 minutes of exposure. Cross-linking of neither CD11a nor CD11c induced CD64 expression. In contrast to slow induction by IFN-gamma and G-CSF, the integrin-induced rapid CD64 expression did not require RNA synthesis. Genistein, herbimycin A, and 1,2-bis(o-aminophenoxy)ethan-N,N-N',N'-tetraacetic acid blocked the immediate expression of CD64 in a dose-dependent manner, suggesting that the signal is mediated through calcium mobilization and protein tyrosine kinase(s). Such rapid modulation of the high-affinity Fc gamma RI receptor by integrin cross-linking may reflect the requirement for rapid up-regulation of PMN effector functions, after interaction with endothelial cells, platelets or bacteria.     

Augmentation of human immunodeficiency virus type 1 gene expression by tumor necrosis factor alpha

It is now well established that cytokines are involved in the regulation of gene expression from HIV-1 LTR. The present study provides evidence that TNF-alpha stimulates HIV-1 gene expression and that the enhancer sequence within the HIV-1 LTR is involved in the stimulation. These results support the idea that immunologic stimulation and infection may trigger the development of clinical AIDS in individuals latently infected with HIV-1.     

Insulin-like growth factor I receptor blockade enhances chemotherapy and radiation responses and inhibits tumour growth in human gastric cancer xenografts

BACKGROUND AND AIMS: Insulin-like growth factor (IGF) I receptor (IGF-Ir) signalling is required for carcinogenicity and proliferation of many tumours but this pathway has not been studied in detail in gastric cancer. We have previously shown successful therapy for colorectal, pancreatic, and lung cancer using recombinant adenoviruses expressing dominant negative (dn) IGF-Ir. In this study, we sought to better dissect the role of IGF-Ir on progression of gastric cancer and determine whether IGF-Ir targeted adenoviruses represent potentially effective therapeutics for human gastric cancer. METHODS: We assessed the effect of IGF-Ir ligands on proliferation and survival in gastric cancer cells in culture. Then, recombinant adenoviruses expressing truncated IGF-Ir (482 and 950 amino acids long, IGF-Ir/dn) that function as dn inhibitors were studied in the treatment of human gastric cancer xenografts. We characterised the effects of IGF-Ir/dn on signalling blockade, growth, apoptosis induction, and in vivo therapeutic efficacy. RESULTS: IGF-Ir signalling promoted tumour growth and survival in gastric cancer. IGF-Ir/dn expression suppressed tumorigenicity both in vitro and in vivo and upregulated stressor induced apoptosis. IGF-Ir/dn blocked Akt-1 activation induced by IGF-I, IGF-II, and des(1-3)IGF-I, but not by insulin. IGF-Ir/dn expression increased radiation and chemotherapy induced apoptosis and the combination of IGF-Ir/dn and chemotherapy was very effective against tumours in mice. In an intraperitoneal model, IGF-Ir/dn therapy also suppressed peritoneal dissemination. CONCLUSIONS: IGF-Ir is involved in the regulation of survival and cell growth in human gastric cancer and may be a good molecular therapeutic target. Adenovirus-IGF-Ir/dn may thus have therapeutic use in gastric cancer.     

Coexpression of CD40 and CD40 ligand in Epstein-Barr virus-infected T and NK cells and their role in cell survival

We investigated the role that CD40-CD40 ligand (CD40L) signaling plays in survival of Epstein-Barr virus (EBV)-infected T and NK cells. EBV-infected T and NK cell lines derived from patients with either chronic active EBV infection (CAEBV) or nasal T/NK cell lymphoma, as well as virus-infected peripheral T cells freshly isolated from a patient with CAEBV, were shown to express both CD40 and CD40L on their surface. Apoptosis of these cells was enhanced by blockade of CD40-CD40L signaling by a fusion protein of CD40 and immunoglobulin G (CD40Ig). Expression of CD40 was induced in human CD40L-positive Jurkat T cells after experimental EBV infection, and apoptosis of infected cells was enhanced by CD40Ig. These results suggest that CD40-CD40L signaling promotes survival of EBV-infected T and NK cells and, thus, plays an important role in the pathogenesis of T/NK lymphoproliferative disorders associated with the virus.     

Angiotensin II type 1a receptor signals are involved in the progression of heart failure in MLP-deficient mice.

BACKGROUND: Angiotensin II (AT) is implicated in the development of cardiac remodeling, which leads to heart failure, and pharmacological inhibition of the AT type 1 (AT1) receptor has improved mortality and morbidity in patients of heart failure. The aim of this study was to elucidate the role of the AT1 receptor in disease progression in muscle LIM protein (MLP)-deficient mice, which are susceptible to heart failure because of defective function of mechanosensors in cardiomyocytes. METHOD AND RESULTS: Hearts from MLP knockout (MLPKO) mice and MLP-AT1a receptor double knockout (DKO) mice were analyzed. MLPKO hearts showed marked chamber dilatation with cardiac fibrosis and reactivation of the fetal gene program. All of these changes were significantly milder in the DKO hearts. Impaired left ventricular (LV) contractility and filling were alleviated in DKO hearts. However, the impaired relaxation and downregulated expression of sarcoplasmic reticulum calcium-ATPase 2 were unchanged in DKO hearts. CONCLUSIONS: The AT1a receptor is involved in progression of LV remodeling and deterioration of cardiac function in the hearts of MLPKO mice. These results suggest that blockade of the receptor is effective in preventing progression of heart failure in dilated cardiomyopathy.     

Autoimmune hepatitis associated with Graves' disease

A 31-year-old woman with Graves' disease with a 12-month-history of propylthiouracil intake and autoantibodies in the sera was admitted to our hospital. The differential diagnosis between autoimmune hepatitis and propylthiouracil-induced hepatitis was intractable. Steroid therapy was started and she showed a complete response to the treatment. Liver biopsy demonstrated acute hepatitis and plasma cell infiltration. A second liver biopsy, which was performed 10 months after starting steroid therapy, showed some inflammatory cells in the portal tracts. These findings suggest that she had been suffering from autoimmune hepatitis.