Histology and histopathology Vol.25, nº9 (2010)
Permanent URI for this collection
Browse
Browsing Histology and histopathology Vol.25, nº9 (2010) by Issue Date
Now showing 1 - 12 of 12
Results Per Page
Sort Options
- PublicationOpen AccessPerspectives of SLIT-ROBO signaling in placental angiogenesis(Murcia : F. Hernández, 2010) Liao, Wu-xiang; Wing, Deborah A.; Geng, Jian-Guo; Chen, Dong-baoA novel family of evolutionally conserved neuronal guidance cues, including ligands (i.e., Slit, netrin, epherin, and semaphorin) and their corresponding receptors (i.e., Robo, DCC/Unc5, Eph and plexin/ neuropilin), has been identified to play a crucial role in axon pathfinding and branching as well as neuronal cell migration. The presence of commonalities in both neural and vascular developments has led to some exciting discoveries recently, which have extended the functions of these systems to vascular formation (vasculogenesis) and development (angiogenesis). Some of these ligands and receptors have been found to be expressed in the vasculature and surrounding tissues in physiological and pathological conditions. It is postulated that they regulate the formation and integrity of blood vessels. In particular, it has been shown that the Slit/Robo pair plays a novel role in angiogenesis during tumorigenesis and vascular formation during embryogenesis. Herein we summarize briefly the characteristics of this family of neuronal guidance molecules and discuss the extraneural expression and function of the Slit/Robo pair in angiogenesis in physiological and pathological settings. We report expression of Robo1 protein in capillary endothelium and co-expression of Slit2 and Robo1 proteins in syncytiotrophoblast in healthy term human placental villi. These cellular expression patterns implicate that the Slit/Robo signaling plays an autocrine and/or paracrine role in angiogenesis and trophoblast functions. We also speculate a possible role of this system in pathophysiological placental angiogenesis.
- PublicationOpen AccessHuman retinal pigment epithelial SPARC expression and age: an immunohistochemical study(Murcia : F. Hernández, 2010) Howard, Claire; Garcia Fiñana, Marta; Yan, Qi; Hiscott, PaulThe aim of this study was to investigate the temporal and spatial expression of the matricellular protein SPARC (Secreted Protein, Acidic and Rich in Cysteine; also known as osteonectin) in human retinal pigment epithelial (RPE) cells, and compare the results with Bruch’s membrane thickness, employing immunohistochemistry. Eyes from 36 human donors, 16 being ≤65 and 20 >65 years old, were included in the study. Intensity of SPARC immunoreactivity was evaluated using Aequitas Image Analysis software with two-way analysis of variance (ANOVA). Bruch’s membrane thickness was assessed by profile analysis and the association between RPE SPARC immunoreactivity and Bruch’s membrane thickness was investigated by fitting a linear mixed effects model to the data set. Intensity of SPARC immunostaining in RPE cells was significantly lower in older donors (p<0.05 and p<0.001 for posterior and peripheral RPE cells, respectively). The anatomical localisation of the RPE cells also affected the intensity of SPARC staining, which was lower in posterior compared to peripheral cells (p<0.01). No correlation was observed between SPARC immunoreactivity in RPE cells and the thickness of the underlying Bruch’s membrane, in either posterior or peripheral regions. Our results suggest that RPE cell SPARC levels decline with age, a change that may play a role in the pathogenesis of age-related diseases such as age-related macular degeneration.
- PublicationOpen AccessMorphologic changes and methodological issues in the rabbit experimental model for diaphragmatic hernia(Murcia : F. Hernández, 2010) Roubliova, Xenia I.; Deprest, Jan A.; Biard, Jean Marc; Ophalvens, Lieve; Gallot, Denis; Jani, Jacques C.; Van de Ven, Cornelis P.; Tibboel, Dick; Verbeken, Erik K.Summary. Fetal lung development may be impaired by some congenital anomalies or in utero events. Animal models are used to understand the pathophysiology of these diseases and explore therapeutic strategies. Our group has an interest in the prenatal management of congenital diaphragmatic hernia (CDH). Isolated CDH remains associated with a 30% mortality because of lung hypoplasia and pulmonary hypertension. On day 23 of gestation (pseudoglandular stage) CDH was created in both ovarian-end fetuses (n=28) in 14 time-mated pregnant white rabbits (hybrid of Dendermonde and New-Zealand White). At term (day 30) all survived operated fetuses and size-matched controls were harvested. Fetuses/lungs were assigned randomly to formalin fixation either under pressure of 25 cm H2O (CDH25 n=5; CTR25 n=5) or without (0 cm H2O (CDH0 n=7; CTR0 n=7). Fetuses and lungs were first weighed, and then the lungs were processed for morphometry. Pulmonary development was evaluated by lung-to-body weight ratio (LBWR) and airway and vascular morphometry. Surgical induction of CDH does reduce the LBWR to hypoplastic levels. The contralateral lung weight is 81% of what is expected, whereas the ipsilateral lung is only 46% of the normal. This was accompagnied by a loss of conducting airway generations, precisely, terminal bronchioles (TB), which were surrounded by less alveoli. The ipsilateral CDH lung demonstrated a thickened media in the peripheral arteries as well. As a result, in the severely hypoplastic ipsilateral lung, an airway fixation pressure of 25 H2O has no significant effect on the morphometric indices. The contralateral lung has a normal amount of alveoli around a single TB, which also behave like alveoli of the normal lung, i.e. expand under pressure fixation. The present study on severely hypoplastic lungs that never respirated, shows that in contrast to normal lungs, the morphometric indices are not significantly influenced by a difference in fixation pressure. Increasing fixation pressure seems to expand the lung only when sufficient alveolated parenchyma is present.
- PublicationOpen AccessA role for mammalian target of rapamycin -mTOR- pathway in non alcoholic steatohepatitis related-cirrhosis(Murcia : F. Hernández, 2010) Kubrusly, Márcia Saldanha; Corrêa-Giannella, Maria Lúcia; Bellodi-Privato, Marta; de Sá, Sandra Valéria; Cauduro Soares, Iberê; Wakamatsu, Alda; Avancini Ferreira Alves, Venâncio; Giannella-Neto, Daniel; Bacchella, Telesforo; Cerqueira Cesar Machado, Marcel; Carneiro D’Albuquerque, Luiz Augusto; Pinto Marques Souza de Oliveira, ClaudiaSummary. Non-alcoholic fatty liver disease (NAFLD) encompasses the whole spectrum of steatosis, nonalcoholic steatohepatitis (NASH), and NASH-related cirrhosis (NASH/Cir). Although molecular advances have been made in this field, the pathogenesis of NAFLD is not completely understood. The gene expression profiling associated to NASH/Cir was assessed, in an attempt to better characterize the pathways involved in its etiopathogenesis. Methods: In the first step, we used cDNA microarray to evaluate the gene expression profiles in normal liver (n=3) and NASH/Cir samples (n=3) by GeneSifter™ analysis to identify differentially expressed genes and biological pathways. Second, tissue microarray was used to determine immunohistochemical expression of phosphorylated mTOR and 4E-BP1 in 11 normal liver samples, 10 NASH/Cir samples and in 37 samples of cirrhosis of other etiologies to further explore the involvement of the mTOR pathway evidenced by the gene expression analysis. Results: 138 and 106 genes were, respectively, up and down regulated in NASH/Cir in comparison to normal liver. Among the 9 pathways identified as significantly modulated in NASH/Cir, the participation of the mTOR pathway was confirmed, since expression of cytoplasmic and membrane phosphomTOR were higher in NASH/Cir in comparison to cirrhosis of other etiologies and to normal liver. Conclusions: Recent findings have suggested a role for the cellular “nutrient sensor” mTOR in NAFLD and the present study corroborates the participation of this pathway in NASH/Cir. Phospho-mTOR evaluation might be of clinical utility as a potential marker for identification of NASH/Cir in cases mistakenly considered as cryptogenic cirrhosis owing to paucity of clinical data.
- PublicationOpen AccessTemporomandibular joint disc; a proposed histopathological degeneration grading score system(Murcia : F. Hernández, 2010) Leonardi, Rosalia; Rusu, Mugurel Constantin; Loreto, C.Summary. Aims: The purpose of this study was to draw up a TMJ disc histopathological score that is a semiquantitative transcription of the entire spectrum of TMJ disc degenerative diseases related to changes in disc tissue, and then validate the proposed grading, in order to contribute to a standardized histopathological diagnosis. Methods: Sections from sixty two temporomandibular joint disc specimens affected by tissue degenerative changes and stained with Hematoxylin & Eosin (H&E) were collected from among those found in the archives of the Department of Dentistry at Catania University. Specimens, included anterior, intermediate and posterior disc bands. Based on a literature search regarding the most frequent histopathological changes detected in TMJ disc tissue a grading score was designed. This score takes into account pathological disc tissue transformation i.e. collagen bundles, non-specific degenerative changes and the presence of blood vessels. This grading system results in a score ranging from 0 up to 8 for heavily degenerated disc tissue. Two observers performed the assessment of the TMJ disc H&E stained sections. Each specimen was scored twice by each observer after a minimum interval of 1 week. Results: The average TMJ disc degeneration score of the TMJ disc sample was 3.89±1.37. There was an almost perfect agreement, between the two observers, and degeneration scores from the two observers were highly correlated. Conclusions: The introduction of this validated degeneration score system may be of major importance for future research and collaboration between different centers in order to improve knowledge in TMJ disc histopathology.
- PublicationOpen AccessFISH analysis for diagnostic evaluation of challenging melanocytic lesions(Murcia : F. Hernández, 2010) Zimmermann, Anne-Katrin; Hirschmann, Astrid; Pfeiffer, David; Paredes, Bruno E.; Diebold, JoachimThe differential diagnosis of malignant melanomas and atypical melanocytic nevi is still a diagnostic challenge. The currently accepted morphologic criteria show substantial interobserver variability, likewise immunohistochemical studies are often not able to discriminate these lesions reliably. Techniques that support diagnostic accuracy are of the greatest importance considering the growing incidence of malignant melanomas and their increase in younger patients. In this study we analyzed the feasibility of fluorescence in situ hybridization (FISH) analysis for the discrimination of malignant and benign melanocytic tumors. A panel of DNA probes was used to detect chromosomal aberrations of chromosomes 6 and 11. On a series of 5 clearly malignant and benign melanocytic tumors we confirmed the applicability of the test. Then we focused on examination of ambiguous melanocytic lesions, where atypical cells are often difficult to relocalize in the 4',6-Diamidino-2-phenylindol (DAPI)- fluorescence stain. FISH analyses were conducted on destained H&E-stained slides. By comparison of the DAPI-image with photos taken from the H&E stain, unambiguous assignment of the FISH results to the conspicuous groups of cells was possible. The results of FISH analysis were consistent with the conventional diagnosis in 11 of 14 small ambiguous lesions. Of the remaining 3 cases, 2 showed FISH-results close to the cut-off level. Comparison of FISH results on thin and thick sections revealed that the cut-off values have to be adopted for 2 µm destained sections. In conclusion, FISH analysis is a useful and applicable tool for assessment of even smallest melanocytic neoplasms, although there will remain unclear cases that cannot be solved even after additional FISH evaluation.
- PublicationOpen AccessEGFR expression and activation are common in HER2 positive and triple-negative breast tumours(Murcia : F. Hernández, 2010) Koletsa, T.; Kotoula, Vassiliki; Karayannopoulou, Georgia; Nenopoulou, E.EGFR has been associated with unfavourable prognosis in patients with triple-negative breast carcinomas, although little is known about EGFR activation in these tumours. In a series of breast carcinomas (archived formalin fixed tumours, n=100), we investigated EGFR phosphorylation status at Tyr992 (pEGFR-Y992) and Tyr1068 (pEGFR-Y1068) by immunohistochemistry, along with EGFR protein expression (extracellular domain), gene amplification status (fluorescent in situ hybridization) and conventional clinicopathologic parameters. EGFR protein was present in 21.9%, while phosphorylation at Y1068 and Y992 was observed in 27.8% and 50.5% of tumours, respectively. None of the tumours showed EGFR gene amplification, whereas 21.1% exhibited chromosome 7 polysomy. The above EGFR parameters were usually not simultaneously detected and were not associated with each other. High grade (p=0.003), lymph node positive (p=0.045), estrogen receptor (ER) negative (p<0.001) tumours often expressed EGFR protein. EGFR-Y992 and Y1068 phosphorylation was inversely associated with ER presence (p=0.023 and p=0.029, respectively) but positively with HER2 expression status (p<0.001 and p=0.002, respectively). The global positivity for any EGFR parameter did not significantly differ between triple-negative and HER2 positive tumours. In conclusion, EGFR phosphorylation is commonly encountered in breast carcinomas, although unrelated to EGFR protein presence and gene amplification. EGFR may appear activated even in cases where the extracellular domain of this protein is not observed with immunohistochemistry. These findings may be useful for further studies aiming at the assessment of EGFR parameters on this type of material
- PublicationOpen AccessStandard bone healing stages occur during delayed bone healing, albeit with a different temporal onset and spatial distribution of callus tissues(Murcia: F. Hernández, 2010) Peters, Anja; Schell, Hanna; Bail, Hermann J.; Hannemann, Marion; Schumann, Tanja; Duda, Georg N.; Lienau, JasminBone healing is considered as a recapitulation of a developmental program initiated at the time of injury. This study tested the hypothesis that in delayed bone healing the regular cascade of healing events, including remodeling of woven to lamellar bone, would be similar compared to standard healing, although the temporal onset would be delayed. A tibial osteotomy was performed in sheep and stabilized with a rotationally unstable fixator leading to delayed healing. The sheep were sacrificed at 2, 3, 6, 9 weeks and 6 months postoperatively. The temporal and spatial tissue distributions in the calluses and the bone microstructure were examined by histology. Although histological analysis demonstrated temporal and spatial callus tissue distribution differences, delayed healing exhibited the same characteristic stages as those seen during uneventful standard healing. The delayed healing process was characterized by a prolonged presence of hematoma, a different spatial distribution of new bone and delayed and prolonged endochondral bone formation. A change in the spatial distribution of callus formation was seen by week 6 leading to bone formation and resorption of the cortical bone fragments, dependent on the degree to which the cortical bone fragments were dislocated. At 6 months, only 5 out of 8 animals showed complete bony bridging with a continuous periosteum, although lamellar bone and newly formed woven bone were present in the other 3 animals. This study demonstrates that during delayed bone healing all stages of the healing cascade likely take place, even if bony consolidation does not occur. Furthermore, the healing outcome might be related to the periosteum’s regenerative capacity leading to bony union or absence of bony bridging.
- PublicationOpen AccessMolecular mechanisms of gap junction mutations in myelinating cells(Murcia : F. Hernández, 2010) Sargiannidou, Irene; Markoullis, Kyriaki; Kleopa, Kleopas A.There is an emerging group of neurological disorders that result from genetic mutations affecting gap junction proteins in myelinating cells. The X-linked form of Charcot Marie Tooth disease (CMT1X) is caused by numerous mutations in the GJB1 gene encoding the gap junction protein connexin32 (Cx32), which is expressed in both Schwann cells in the PNS and oligodendrocytes in the CNS. Patients with CMT1X present mainly with a progressive peripheral neuropathy, showing mixed axonal and demyelinating features. In many cases there is also clinical or subclinical involvement of the CNS with acute or chronic phenotypes of encephalopathy. Furthermore, mutations in the GJA12/GJC2 gene encoding the gap junction protein Cx47, which is expressed in oligodendrocytes, have been identified in families with progressive leukodystrophy, known as Pelizaeus-Merzbacher-like disease, as well as in patients with hereditary spastic paraplegia. Recent studies have provided insights into the pattern of gap junction protein expression and function in CNS and PNS myelinating cells. Furthermore, in vitro and in vivo disease models have clarified some of the molecular and cellular mechanisms underlying these disorders. Here we provide an overview of the clinical, genetic, and neurobiological aspects of gap junction disorders affecting the nervous system.
- PublicationOpen AccessParticular functions of estrogen and progesterone in establishment of uterine receptivity and embryo implantation(Murcia : F. Hernández, 2010) Ozturk, Saffet; Demir, RamazanThe process of embryo implantation requires synchronized development of blastocyst and timely establishment of uterine receptivity. Establishment of uterine receptivity, preimplantation embryo development and embryo implantation events are mainly regulated by certain factors, including cytokines, chemokines, growth factors and steroid hormones. Recent studies suggest that steroid hormones, especially estrogen and progesterone, play important roles in supporting endometrial preparations to establish endometrial receptivity. Timely establishment of endometrial receptivity is a crucial process for providing successful embryo implantation. Although many investigations until now have been performed to precisely understand the effects of estrogen and progesterone on acquiring uterine receptivity and embryo implantation in humans and rodents, there are limited numbers of studies that largely focus on this subject. Therefore, in this article we discuss the studies associated with significant functions of estrogen and progesterone in establishing receptive endometrium and the process of embryo implantation in humans and rodents.
- PublicationOpen AccessTransactivation of Trk receptors in spinal motor neurons(Murcia : F. Hernández, 2010) Domeniconi, Marco; Chao, Moses, V.The neurotrophins are a family of trophic factors that have been shown to have neuroprotective effects after traumatic lesions of the nervous system and in animal models of neurodegenerative diseases. They mediate a broad spectrum of biological actions by interacting with tyrosine kinase receptors (Trk). While studies have demonstrated that neurotrophin administration may have beneficial effects, there were difficulties in delivering therapeutic quantities of these factors to spinal motor neurons. We now describe a strategy for applying transactivation of Trk receptors using small molecules, such as adenosine, which can penetrate the blood brain barrier and rescue motor neurons from cell death. Transactivation opens up the possibility of stimulating Trk receptors only in populations of neurons that co-express both Trk and adenosine receptors. We propose in this review to exploit transactivation to improve the survival of motor neurons in a transgenic mouse model of ALS and for other neurodegenerative diseases, such as Alzheimer’s and Huntington’s disease.
- PublicationOpen AccessExpression of cannabinoid receptors in human kidney(Murcia : F. Hernández, 2010) Larrinaga, Gorka; Varona, Adolfo; Pérez, Itxaro; Sanz, Begoña; Ugalde, AitziberThe presence of CB1 and CB2 cannabinoid receptors and their physiological role in the kidney has been described in animal models but not in humans. Our aim in this study was to evaluate the presence of these receptors in human kidney, adult and fetal. For this purpose, RT-PCR, western-blot and immunohistochemical assays were performed. RT-PCR confirmed the presence of CB1 receptor mRNA receptor and the absence of the CB2 receptor mRNA in adult and fetal kidney. Western-blot and immunohistochemical assays revealed the presence of the CB1 cannabinoid receptor protein, which displayed a similar distribution in fetal and adult kidneys. Proximal and distal convoluted tubule cells and intercalated cells in the collecting ducts showed marked positivity. Conversely, the CB2 cannabinoid receptor protein was consistently negative in all cases. Our data suggest a possible implication of the endocannabinoid system in the physiology and development of the human kidney.