Ultrastructure of testicular macrophages in aging mice

Testicular macrophages of aging mice were studied by TEM. Testicular macrophages retained with Leydig cells the close morphological relationships observed in the adult young animals, but digitations were not found. Lipofuscin granules like those of the Leydig cells from aging mice were observed in the cytoplasm. These organelles were generally absent in the testicular macrophages of young adult mice. Testicular macrophages did not display phagocytosis of the lipofuscin granules. In addition, the latter were not found in the intercellular spaces. These observations indicated that lipofuscin granules were formed, at least in a great part, within testicular macrophages as a consequence of metabolic changes occurring with age. Fine lamellar organization was seen in the lipofuscin granules of both Leydig cells and testicular macrophages. Frequently, lipofuscin granules originated from secondary lysosomes containing lipidic vacuoles only. Together with accumulation of the lipofuscin granules, changes of testicular macrophage fine morphology were observed. Endoplasmic reticulum and Golgi apparatus became poorly developed, and coated vesicles were rarely found. Fewer mitochondria were encountered, but their ultrastructure was not altered. These results suggest that in testicular macrophages lipofuscin accumulation is associated with a functional involution

Endothelial cell binding by systemic lupus antibodies: functional properties and relationship with anti-DNA activity

Anti-DNA antibodies and anti-endothelial cell antibodies (AECA) are often detected in systemic lupus erythematosus (SLE). Anti-DNA antibodies can also bind the membrane of human umbilical vein endothelial cells (HUVEC), but little is known about the presence of AECA in the population of immunoglobulins from SLE sera that do not bind DNA. The aim of this study is to analyse the ability of anti-DNA and non-anti-DNA antibodies from SLE sera to bind endothelial cell antigens and to investigate their pathogenic potential. Both anti-DNA and non-anti-DNA antibodies display AECA activity by immunoprecipitation and flow cytometry and in some patients recognize antigens of identical molecular weight. Complement-dependent cytotoxicity on HUVEC was not detected with either anti-DNA or non-anti-DNA antibodies. Similarly, apoptosis was not induced in HUVEC and HL60 incubated with anti-DNA or non-anti-DNA antibodies, as shown by the DNA hypodiploid content. These data indicate that AECA are highly heterogeneous, as they recognize a wide variety of surface molecules on HUVEC and equally present in anti-DNA and non-anti-DNA antibodies from SLE patients

Il ruolo dell’ossido nitrico nella mucosa nasale

Nitric oxide is a small gaseous molecule produced in many types of mammalian cells, in which it contributes to a variety of physiologic and pathophysiologic processes. The presence in the upper airways of high concentrations of nitric oxide has important effects for the field of otorhinolaryngology. In fact, several pieces of evidences have suggested that in the nasal respiratory mucosa nitric oxide plays significant functions, such as mucociliary clearance, vascular homeostasis, immune defense and cytotoxicity. The immunohistochemical and ultracytochemical studies have provided a number of evidences to know more about the role that nitric oxide plays in the nasal respiratory mucosa, both in healthy subjects and in some pathological conditions. Nevertheless, as several functional roles played by the nitric oxide in the nasal respiratory mucosa remain to be elucidated, further researches are required to understand fully the role of nitric oxide in the upper airways

Inflammatory mediators and eosinophilia in atopic and non-atopic patients with nasal polyposis.

Nasal polyps are characterized by eosinophilic infiltration and presence of inflammatory mediators, such as total IgE, eosinophil cationic protein (ECP) and cytokines. The role of atopy in nasal polyp pathogenesis is still unclear. Therefore, we evaluated serum IgE levels, nasal mucus concentrations of ECP and cytokines and the number of infiltrating eosinophils in nasal tissue of polyps from atopic and non-atopic patients. Samples were obtained from a randomized population of 31 patients with nasal polyposis having endonasal sinus surgery and of 13 control subjects undergone corrective surgery of the nasal septum. On the basis of medical history of allergy, positive skin-prick tests and total IgE levels, patients with polyposis were divided in atopic (n = 13) and non-atopic (n = 18) patients. We determined levels of IgE in blood, ECP and cytokines (IL-4, IL-6, IL-8, IFN-gamma and IL-2) in nasal mucus, and number of infiltrating eosinophils in nasal tissue. The concentrations of total IgE, ECP, IL-4 and IL-8 and eosinophilia were significantly higher in all patients with nasal polyps compared with controls. Inside, all patients with nasal polyposis showed lower levels of IL-6, IFN-gamma and IL-2 compared with controls. The atopic patients showed significant differences when compared with non-atopic patients for the higher concentrations of total IgE (698.80+/-322.24 vs. 279.63+/-234.11; P < 0.0001) and IL-8 (1437.2 pg/ml+/-1250.7 vs. 605.5 pg/ml+/-481.1; P < 0.015). These findings suggest that inflammation still remains the major factor in the etiology of nasal polyposis and show different levels of inflammatory mediators into atopic and non-atopic patients

Distribution of 3-Nitrotyrosine in the nasal polyps of atopic patients.

Objective. To investigate whether formation of nitrotyrosine in the nasal polyps of atopic patients occurs. Study Design. A nonrandomized, retrospective, controlled qualitative and quantitative study. Methods. Nasal polyp tissue samples were acquired from 12 atopic patients. Control fragments of nasal mucosa were taken from 10 patients undergoing corrective surgery of the nasal septum. For routine histologic examinations, hematoxylin-eosin staining was used. Low-magnification microscopy was designed to yield pathologic characteristics and high magnification to quantify the number of eosinophils in the subepithelial connective tissue. Presence of nitrotyrosine was assessed by immunohistochemical method. Results: Hematoxylin-eosin staining revealed presence of numerous eosinophils in the epithelium and in the subepithelial connective tissue. All polyps were characterized by epithelial damage. Nitrotyrosine was present in the eosinophils, in the ciliated cell, and in cells of the damaged epithelium. Goblet cells, glands, and vessels were found to be negative. No significant differences concerning the localization of nitrotyrosine were recognized among the examined nasal polyps. Conclusions: Nitrotyrosine immunohistochemical staining in nasal-polyp tissues suggested the existence of progressive. epithelium injury caused by peroxynitrite. Consequences of peroxynitrite formation in eosinophils remain to be precisely established. The lack of nitrotyrosine in glands and blood vessels indicated that peroxynitrite does not have a significant role in the vascular and glandular dysfunction of nasal polyp

ETA receptor-mediated Ca2+ mobilisation in H9c2 cardiac cells

Expression and pharmacological properties of endothelin receptors (ETRs) were investigated in H9c2 cardiomyoblasts. The mechanism of receptor-mediated modulation of intracellular Ca2+ concentration ([Ca2+](i)) was examined by measuring fluorescence increase of Fluo-3-loaded cells with flow cytometry. Binding assays showed that [I-125]endothelin-1 (ET-1) bound to a single class of high affinity binding sites in cardiomyoblast membranes. Endothelin-3 (ET-3) displaced bound [I-125]ET-1 in a biphasic manner, in contrast to an ETB-selective agonist, IRL-1620, that was ineffective. The ETB-selective antagonist, BQ-788, inhibited [(125) I]ET-1 binding in a monophasic manner and with low potency. An ETA-selective antagonist, BQ-123, competed [I-125]ET-I binding in a monophasic manner. This antagonist was found to be 13-fold more potent than BQ-788. Immunoblotting analysis using anti-ETA and -ETB antibodies confirmed a predominant expression of the ETA receptor. ET-1 induced a concentration-dependent increase of Fluo-3 fluorescence in cardiomyoblasts resuspended in buffer containing I mM CaCl2. Treatment of cells with antagonists, PD-145065 and BQ-123, or a phospholipase C-P inhibitor, U-73122, abolished ET-1-mediated increases in fluorescence. The close structural analogue of U-73122, U-73343, caused a minimal effect on the concentration-response curve of ET-1. ET-3 produced no major increase of Fluo-3 fluorescence. Removal of extracellular Ca2+ resulted in a shift to the right of the ET-I concentration-response curve. Both the L-type voltage-operated Ca2+ channel blocker, nifedipine, and the ryanodine receptor inhibitor, dantrolene, reduced the efficacy of ET-1. Two protein kinase C inhibitors reduced both potency and efficacy of ET-I. Our results demonstrate that ETA receptors are expressed and functionally coupled to rise of [Ca2+](i) in H9c2 cardiomyoblasts. ET-1-induced [Ca2+](i) increase is triggered by Ca2+ release from intracellular inositol 1,4,5-trisphosphate-gated stores; plasma membrane Ca2+ channels and ryanodine receptors participate in sustaining the Ca2+ response. Regulation of channel opening by protein kinase C is also involved in the process of [Ca2+](i) increase. (C) 2002 Elsevier Science Inc. All rights reserved