Histology and histopathology Vol.23, nº3 (2008)
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- PublicationOpen AccessUltrastructural study of human glomerular capillary loops with IgA nephropathy using quick-freezing and deep-etching method(Murcia : F. Hernández, 2008) Sawanobori, E.; Terada, N.; Fuji, Y.; Higashida, K.; Nakazawa, S.; Ohno, S.Immunoglobulin A (IgA) nephropathy shows great variability regarding the histological features of the lesions of human renal glomeruli. In the present study, the quick-freezing and deep-etching (QF-DE) method was used to analyze the glomerular ultrastructure of biopsied kidney tissues from children with IgA nephropathy. Biopsied renal tissues were routinely prepared for light microscopy, immunofluorescence microscopy, conventional electron microscopy, and replica electron microscopy. The three-dimensional ultrastructure of glomeruli of the kidney was clearly observed by using the QF-DE method. Three layers of glomerular basement membranes, i.e., middle, inner and outer layers, were clearly detected in the replica electron micrographs. The middle layer was 343.0±24.2 nm (n=20) in width and formed polygonal meshwork structures. We also observed slit diaphragms, electrondense mesangial deposits, and increased amounts of mesangial matrix and foot process effacement. Many delicate filaments were found to be distributed from the apical to the bottom portions between neighboring foot processes. The ultrastructural difference between the replica electron micrographs and conventional electron micrographs was found to be especially marked in the appearance of foot processes and connecting filaments between the neighboring foot processes. The examination of extracellular matrix changes, as revealed at high resolution by the QF-DE method, gave us some morphofunctional information relevant to the mechanism of proteinuria with IgA nephropathy.
- PublicationOpen AccessApoptosis of the cerebellar neurons(Murcia : F. Hernández, 2008) Lossi, Laura; Gambino, GrazianaNaturally occurring neuronal death (NOND) is an essential phenomenon during the course of normal development of the nervous system. Studies in vivo and on organotypic cultures have helped to elucidate the basic histological and ultrastructural features, as well as the main cellular mechanisms of NOND in several areas of the brain. This review examines the existing evidence about the two waves of apoptotic cell death that affect the different types of cerebellar neurons in normal development and certain pathological conditions. The first wave regards neuronal progenitors and premigratory neuroblasts, the second post-migratory neuroblasts and mature neurons. The underlying cellular and molecular mechanisms are discussed critically also in the light of their relevance to neurodegenerative diseases.
- PublicationOpen AccessExpression of activity-dependent neuroprotective protein in the brain of adult rats(Murcia : F. Hernández, 2008) Gennet, N.; Herden, C.; Bubb, V.J.; Quinn, J.P.; Kipar, A.Activity-dependent neuroprotective protein (ADNP) is a VIP-regulated gene, which is essential for brain development. A synthetic peptide (NAP) derived from the ADNP sequence is highly neuroprotective, therefore it has been hypothesised that ADNP has a similar role. ADNP contains classical transcription factor motifs and nuclear localisation domains, but it has also been reported to be secreted and to co-localise with microtubules, indicating that ADNP may have multiple functions. We investigated the pattern of ADNP expression by immunohistology in normal rat brain, in order to generate a framework for future studies examining changes in ADNP expression in response to noxious stimuli or in models of disease. We found widespread ADNP-like immunoreactivity in neurons throughout the rat brain, with the highest expression in the cerebellum, and strong expression in the thalamus, mesencephalon, pons and medulla oblongata. ADNPlike immunoreactivity was mainly observed in the cytoplasm of neurons, and fibre tracts were often strongly positive as well. In addition, positive neuronal nuclei were occasionally observed. ADNP-like immunoreactivity was lost in degenerating ‘dark’ neurons, the morphologically unaltered adjacent cells. Occasional astrocyte and microglial cells were also positive. We suggest that the widespread expression of ADNP may correlate with the wide-ranging protective effects of NAP, and that the cytoplasmic and axonal localisation of ADNP-like immunoreactivity suggests additional, nontranscriptional functions of ADNP
- PublicationOpen AccessAbnormal collagen deposition in synovia after collagen type V immunization in rabbits(Murcia : F. Hernández, 2008) Tsuzuki Ichicawa Ogido, Luciana; Walcy Rosolia, Teodoro; Pereira Velosa, Ana Paula; De Oliveira, Cristiane Carla; Roger Parra, Edwin; Capelozzi, Vera Luiza; Hajime Yoshinari, NatalinoSinovitis in Scleroderma (SSc) is rare, usually aggressive and fully resembles rheumatoid arthritis. Experimental models of SSc have been used in an attempt to understand its pathogenesis. Previous studies done in our laboratory had already revealed the presence of a synovial remodeling process in rabbits immunized with collagen V. To validate the importance of collagen type V and to explore the quantitative relationship between this factor and synovia remodeling as well as the relationship between collagen type V and other collagens, we studied the synovial tissue in immunized rabbits. Rabbits (N=10) were immunized with collagen V plus Freund’s adjuvant and compared with animals inoculated with adjuvant only (N=10). Synovial tissues were submitted to histological analysis, immunolocalization to collagen I, III and V and biochemical analysis by eletrophoresis, immunoblot and densitometric method. The synovial tissue presented an intense remodeling process with deposits of collagen types I, III and V after 75 and 120 days of immunization, mainly distributed around the vessels and interstitium of synovial extracellular matrix. Densitometric analysis confirmed the increased synthesis of collagen I, III and V chains (407.69±80.31; 24.46±2.58; 70.51±7.66, respectively) in immunized rabbits when compared with animals from control group (164.91±15.67; 12.89±1.05; 32±3.57) (p<0.0001). We conclude that synovial remodeling observed in the experimental model can reflect the articular compromise present in patients with scleroderma. Certainly, this experimental model induced by collagen V immunization will bring new insights in to pathogenic mechanisms and allow the testing of new therapeutic strategies to ameliorate the prognosis for scleroderma patients.
- PublicationOpen AccessMelanocyte localization and distribution in human cholesteatoma(Murcia : F. Hernández, 2008) Olszewska, E.; Wagner, M.; Goon, Peter; Shamaa, Ali; Upile, Tao; Rogowski, Marek; Steinstaesser, Lars; Sudhoff, H.Introduction: Melanocytes in skin are derived from the neural crest and colonize the epidermis in the first trimester of gestation. Melanocytes have been observed in the nasopharyngeal, inner ear and oral mucosa and should therefore be present in the middle ear mucosa. Aims: To identify and determine the distribution of melanocytes in human cholesteatoma and normal meatal skin in Caucasian adults. Material and methods: Human cholesteatoma (n=18) and normal meatal skin samples (n=10) were investigated immunohistochemically with anti-HMB-45 and MART- 1 antibodies. Localization and distribution of melanocytes were assessed in the epidermis and cholesteatoma using an automatic analyzing system. Results: Regular skin exhibited melanocytes within the epidermis and accounted for 10% of the total cell number. They occurred partly as membrane-bound clusters. Cholesteatoma matrix melanocytes were observed in the basal layer and exhibited an oval or roundmorphology. Decreased numbers of melanocytes in the basal layer correlated with keratinization within cholesteatoma samples. Melanocytes revealed monomorphous nuclei, abundant cytoplasm containing particles of melanin. Found adjacent to glands and blood vessels, melanocytes were also scattered among the mesenchymal cells. Accounting for 2-6% of the total cell number within the squamous epithelium, melanocyte density was significantly lower in cholesteatoma tissue than in skin. Conclusions: The melanocyte distribution pattern was different when comparing the epithelia of skin and cholesteatoma. The presence of melanocytes in cholesteatoma may be due to an ingrowth, consequently controlled by keratinocyte-derived signals. In terms of the pathogenesis of cholesteatoma, neither squamous metaplasia nor melanocyte metaplasia can be excluded by our data.
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