RESUMEN
Membrane microparticles are shed from the plasma membrane of most eukaryotic cells when these cells were undergone activation or apoptosis, and released into the extracellular environment. Their composition depends on the cellular origin and processes triggering their formation. Several lines of evidence suggest that membrane microparticles might be able to facilitate cell-cell cross-talk and play an important roles in the regulation of survival, proliferation, differentiation, adhesion and chemotaxis of hematopoietic cells. Here, the components, mechanism of formation and the regulatory roles of membrane microparticles in hematopoiesis were reviewed.
Asunto(s)
Humanos , Caveolas , Metabolismo , Fisiología , Membrana Celular , Metabolismo , Fisiología , Hematopoyesis , Fisiología , Modelos Biológicos , Proteínas R-SNARE , Metabolismo , FisiologíaRESUMEN
<p><b>OBJECTIVES</b>To explore the clinical and pathological features and the pathogenesis of primary biliary cirrhosis (PBC) in Chinese Mainland.</p><p><b>METHODS</b>30 PBC patients were divided into the early group (Scheuer stage I and II, 19 patients) and the late group (Scheuer stage III and IV, 11 patients). The data of clinics and serology were analyzed, and the pathological features of the liver tissues were characterized. The changes of dendritic cells (DCs) and hepatic stellate cells (HSCs) were studied by immunohistochemistry.</p><p><b>RESULTS</b>In all the PBC patients, the rate of the male to the female was 1 to 5, and the average age was 40.6 years. The mean levels of TBiL, ALP and GGT in the sera were (95.9+-88.5) micromol/L, (537.2+-339.2) U/L, and (582.0+-351.2) U/L, respectively. 73.3% patients showed AMA positive, and the level of GGT was positively correlated with the AMA level according to the result of statistical analysis (r=0.778, P=0.000). The symptoms of jaundice and hepatomegaly were presented more commonly in the late group than those in the early group (chi2=5.182, P<0.05; chi2=13.659, P<0.01, respectively). The main changes of morphology of PBC located in portal tracts. The liver tissues in the early stage of PBC showed the damage of bile ducts and obvious proliferation of small bile ducts. The granulomas, the lymphoid follicles and the foamy cells were found in the liver tissues of PBC (2/19 patients, 12/19 patients, and 10/19 patients in the early stage respectively, while 0/11 patients, 4/11 patients, and 3/11 patients in the late stage respectively). There was significant difference between the early stage and the late stage in presence of the lymphoid follicles and the foamy cells (t=4.489, P<0.05; t=4.019, P<0.05, respectively). The biliary pigmentary particles were mainly accumulated in the liver cells around the portal tracts in 90.0% PBC patients, and the accumulation of copper and iron increased, compared with that in normal specimens. The DCs and HSCs located mainly in the portal tracts, especially around the damaged bile ducts.</p><p><b>CONCLUSIONS</b>There are some clinical and pathological characteristics in the patients with PBC. The level of AMA has no direct relationship with the level of transaminase or bilirubin. The proliferated bile ductules may express the antigens which maybe the target of immune attack. As an antigen-presenting cell, DCs may play an important role in the pathogenesis of PBC.</p>
Asunto(s)
Adolescente , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Anticuerpos Antinucleares , Sangre , Células Presentadoras de Antígenos , Alergia e Inmunología , Patología , Células Dendríticas , Patología , Hígado , Patología , Cirrosis Hepática Biliar , Alergia e Inmunología , Patología , Mitocondrias , Alergia e InmunologíaRESUMEN
<p><b>BACKGROUND</b>To explore the pathological features and pathogenesis of severe acute respiratory syndrome (SARS) to provide evidence for the clinical treatment and prevention of SARS.</p><p><b>METHODS</b>Pathological features of 2 cases of full autopsy and 4 cases of needle biopsy tissue samples from the patients who died from SARS were studied by light and electron microscopy. The distribution and quantity of lymphocyte subpopulations in the lungs and immune organs from SARS patients were analyzed by immunohistochemistry. The location and semi-quantitative analysis of SARS coronavirus in the tissue specimens were studied by electron microscopy, in situ hybridization and immunohistochemistry.</p><p><b>RESULTS</b>In total of 6 cases, diffuse alveolar damage and alveolar cell proliferation were common. The major pathological changes of 2 autopsy cases of SARS in lung tissues were acute pulmonary interstitial and alveolar exudative inflammation, and 2 autopsy and one biopsy lung tissues showed alveolar hyaline membrane formation. Terminal bronchiolar and alveolar desquamation of lung tissues in one autopsy and 2 biopsy cases were noted. Among 6 cases, 2 biopsy cases presented early pulmonary fibrosis and alveolar organization. Meanwhile, the immune organs, including lymph nodes and spleens from 2 autopsy cases of SARS whose disease courses were less than 12 days showed extensive hemorrhagic necrosis, reactive macrophage/histocyte proliferation, with relative depression of mononuclear and granulocytic clones in the bone marrows. However, spleen and bone marrow biopsy tissue samples from 4 dead SARS cases whose clinical course lasted from 21 to 40 days presented repairing changes. SARS coronaviruses were mainly identified in type I and II alveolar epithelia, macrophages, and endothelia; meanwhile, some renal tubular epithelial cells, cardiomyocytes, mucosal and crypt epithelial cells of gastrointestinal tracts, parenchymal cells in adrenal glands, lymphocytes, testicular epithelial cells and Leydig's cells were also detected by electron microscopy combined with in situ hybridization. The semi-quantitative analysis of lymphocyte subpopulations revealed that the proportion of CD8+ T lymphocytes were about 80% of the total infiltrative inflammatory cells in the pulmonary interstitium, with a few CD4+ lymphocytes CD3+, CD4+, CD8+ or CD20+ lymphocyte subpopulations were obviously decreased and there was imbalance in number and proportion, while CD57+, CD68+, S-100+ and HLA-DR+ cells were relatively increased in lymph nodes and spleens.</p><p><b>CONCLUSIONS</b>Histologically, the pulmonary changes could be divided into acute inflammatory exudative, terminal bronchiolar and alveolar desquamative and proliferative repair stages or types during the pathological process of SARS. SARS coronavirus was found in multi-target cells in vivo, which means that SARS coronavirus might cause multi-organ damages which were predominant in lungs. There were varying degrees of decrease and imbalance in number and proportion of lymphocyte subpopulations in the immune organs of the patients with SARS. However, these changes may be reversible. It was found that cellular immune responses were predominant in the lungs of SARS cases, which might play an important role in getting rid of coronaviruses in infected cells and inducing immune mediated injury.</p>
Asunto(s)
Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pulmón , Alergia e Inmunología , Patología , Virología , Subgrupos Linfocitarios , Alergia e Inmunología , Coronavirus Relacionado al Síndrome Respiratorio Agudo Severo , Síndrome Respiratorio Agudo Grave , Alergia e Inmunología , Patología , VirologíaRESUMEN
<p><b>BACKGROUND</b>To explore the cut-off period of subclassification and pathological features of severe hepatitis (SH).</p><p><b>METHODS</b>Based on combined clinical and pathological analyses, the complete clinical and biopsy or autopsy liver tissues data from 196 cases of patients with severe hepatitis were investigated. Meanwhile, proliferative hepatocytes, cholangioepithelia and collagens were identified by a panel of monoclonal antibodies such as those against albumin, cytokeratin 18,19 and collagen I, III with immunohistochemical method.</p><p><b>RESULTS</b>The clinical and pathological analyses indicated the cut-off periods of acute, subacute and chronic SH (ASH,SSH and CSH) were (13.4+/-7.2) d, (77.4+/-69.3) d and (80.5+/-63.2) d, respectively. Among all SH cases, one case of ASH patient presented clinical manifestation and pathological changes of ASH for 21 days, however, one patient with SSH was demonstrated 12 day course by histological examination. The time of cut-off period between ASH and SSH in child cases was shorter than that in adult cases. Histologically, ASH liver tissues showed massive and/or submassive necrosis caused by one attack, with congestive sinusoid frameworks and proliferative cholangioepithelium-like hepatocytes, while SSH liver tissues presented combined fresh and old submassive or massive necrosis caused by multiple attacks, accompanied by obviously proliferative bile ducts and sinusoid framework collapse.However, the pathological changes of CSH showed ASH- or SSH-like lesions on the background of chronic liver injury.</p><p><b>CONCLUSION</b>Our data indicated that the cut-off period between ASH and SSH is in accordance with the Scheme of Viral Hepatitis Prevention and Therapy, China, published in 2000, but excluded a part of child SH cases. In our study, the authors found a few pathological features in ASH and SSH.</p>