999 resultados para Histochemical methods
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Aims: To compare the efficacy of histochemical and immunohistochemical methods in detecting forms of Sporothrix schenckii in tissue. Methods: Thirty five cutaneous biopsy specimens from 27 patients with sporotrichosis were stained by histochemical haemotoxylin and eosin, periodic acid Schiff, and Gomori's methenamine silver methods and an immunohistochemical (avidin-biotin complex immunoperoxidase) (ABC) technique associated with a newly produced rabbit polyclonal antibody anti-Sporothrix schenckii. Results: A total of 29 (83%) cases were positive by the ABC method used in association with anti-Sporothrix schenckii rabbit polyclonal antibodies. Histochemical methods, using silver staining, periodic acid Schiff, and conventional haematoxylin and eosin detected 37%, 23%, and 23% of forms of S schenckii, respectively. The ABC technique was significantly more reliable than periodic acid Schiff and silver staining techniques. Conclusions: It is concluded that immunostaining is an easy and rapid method which can efficiently increase the accuracy of the diagnosis of sporotrichosis in human tissue.
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The use of glycol methacrylate (GMA) avoids some technical artifacts, which are usually observed in paraffin-embedded sections, providing good morphological resolution. on the other hand, weak staining have been mentioned during the use of different methods in plastic sections. In the present study, changes in the histological staining procedures have been assayed during the use of staining and histochemical methods in different GMA-embedded tissues.Samples of tongue, submandibular and sublingual glands, cartilage, portions of respiratory tract and nervous ganglion were fixed in 4% formaldehyde and embedded in glycol methacrylate. The sections of tongue and nervous ganglion were stained by H&E. Picrosirius, Toluidine Blue and Sudan Black B methods were applied, respectively, for identification of collagen fibers in submandibular gland, sulfated glycosaminoglycans in cartilage (metachromasia) and myelin lipids in nervous ganglion. Periodic Acid-Schiff (PAS) method was used for detection of glycoconjugates in submandibular gland and cartilage while AB/PAS combined methods were applied for detection of mucins in the respiratory tract. In addition, a combination of Alcian Blue (AB) and Picrosirius methods was also assayed in the sublingual gland sections.The GMA-embedded tissue sections showed an optimal morphological integrity and were favorable to the staining methods employed in the present study. In the sections of tongue and nervous ganglion, a good contrast of basophilic and acidophilic structures was obtained by H&E. An intense eosinophilia was observed either in the striated muscle fibers or in the myelin sheaths in which the lipids were preserved and revealed by Sudan Black B. In the cartilage matrix, a strong metachromasia was revealed by Toluidine Blue in the negatively-charged glycosaminoglycans. In the chondrocytes, glycogen granules were intensely positive to PAS method. Extracellular glycoproteins were also PAS positive in the basal membrane and in the region occupied by the lamina externa and reticular fibers surrounding each smooth muscle cells of the blood vessels. In the epithelial cells of the respiratory tract, acid and neutral mucins were histochemically detected by AB and PAS methods, respectively. Moreover, granules containing acid and neutral mucins were revealed in purple by AB and PAS concomitantly. In the sublingual gland sections, a distinct affinity of acid mucins by AB (in turquoise-blue) and collagen fibers by Picrosirius (in red) was obtained when these methods were combined. Although some routine dyes used in paraffin sections have showed a weak stain in historesin sections, our results showed that different dyes could be applied in GMA sections if modified staining procedures were assayed. Therefore, appropriate staining contrast and, thus, detection of one or different substances in a same section can be acquired in association to the good morphological resolution provided by GMA. (C) 2003 Elsevier Ltd. All rights reserved.
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Morphological and histochemical methods were used to evaluate the myotomal muscle characteristics of pacu (Piaractus mesopotamicus) from hatching to 40 days old. During the larval period, the musculature consisted predominantly of white muscle. White and red muscle mass increased at 10, 20, 30 and 40 days after hatching. The larvae had round muscle fibers with a moderate degree of maturation and central nuclei. In subsequent phases, small and immature fibers were visible near larger and more differentiated fibers. Undifferentiated cells or presumptive myoblasts located in embryogenic zones were visible in the dorsal and ventral regions, and were more evident at 30 and 40 days. The red muscle fibers located in the subdermal region, had oxidative metabolism and slow contraction, whereas the more predominant white muscle fibers had glycolytic metabolism and fast contraction. Our findings indicate that during the initial phases, myotomal muscle growth in pacu occurs by both, muscle fiber hypertrophy and hyperplasia. The analysis of frequency of red and white muscle fibers shows that hyperplastic growth is intense in this period. As the growth rate in adult fish is related to the number of muscle fibers in young fish, extrinsic factors could change the muscle fiber phenotype and influence their ultimate size.
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In Portugal, Veterinary Pathology is developing rapidly, and in recent years we assist to the emergence of private laboratories and the restructuring of universities,polytechnics and public laboratories.The Portuguese Society of Animal Pathology,through its actions and its associates has been keeping the discussion among its peers in order to standardizethe criteria of description,classification and evaluation of cases which are the subject of our daily work.One of the last challenges is associated with the use of routine histochemical techniques and immunohistochemistry, in an effort to establish standardized panels for tumour diagnosis, which could eventually reduce each analysis cost.For this purpose a simple survey was built, in which all collaborators answered questions about the markers used for carcinoma, sarcoma and round cell tumour diagnosis, as well as general questions related with the subject. We obtained twenty-one answered to the questions, from public and private laboratories.In general, in most cases immunohistochemical and histochemical methods are used for diagnosis.The wide spectrum cytokeratins are universally used to confirm carcinoma, and vimentin for sarcoma. The CD3 marker is used by all laboratories to identify T lymphocytes. For the diagnosis of B-cell lymphoma, the marker used is not consensual. In each laboratory there are different markers for more specific situations and only two labs perform PCR techniques for diagnosis. These data will be presented to promote extended discussion,namely to reach a consensus when different markers are used.
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Neuronal ceroid-lipofuscinosis (NCL) is a recent term, proposed for acurate designation of the late-onset types of Amaurotic Family Idiocy (AFI). Histopathology shows ubiquitous intraneuronal accumulation of lipopigments, being the most important factor for characterization of the entity at present time. Biochemical changes and pathogenesis are obscure. NCL is in contrast to the infantile type of AFI (Tay-Sachs disease), in which intraneuronal accumulation of gangliosides (sphingolipids) is due to the well known deficiency of a lysosomal enzyme. The authors report on four cases of NCL, two brothers of the late infantile (Jansky-Bielschowsky) type and a brother and a sister of the juvenile (Spielmeyer-Sjögren) type. One autopsy and three cortical biopsies revealed moderate to severe distention of the neurons by lipopigment, with nerve cell loss, gliosis and cerebral atrophy. Lipopigment was also increased in liver, heart and spleen. The patients were the first in Brazilian literature in whom the storage material was identified as lipopigment by histochemical methods. A brief summary of the clinical features of NCL is presented, and relevant problems are discussed, concerning interpretation of the nature of the storage material, and significance of the disease for gerontological research.
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The aim of this study was to evaluate and compare the efficacy of different remobilization protocols in different skeletal muscles considering the changes induced by hindlimb suspension of the tail. Thirty-six female Wistar rats were divided into six groups: control I, control II, suspended, suspended free, suspended trained on a declined treadmill and suspended trained on a flat treadmill. Fragments of soleus and tibialis anterior (TA) muscle were frozen and processed by different histochemical methods. The suspended soleus showed a significant increase in the proportional number of intermediate/hybrid fibers and a decrease in the number of type I fibers. Some of these changes proved to be reversible after remobilization. The three remobilization programs led to the recovery of both the proportional number of fibers and their size. The TA muscle presented a significant increase in the number and size of type I fibers and a cell size reduction of type IIB fibers, which were recovered after training on a declined treadmill and free movement. Especially regarding the soleus, the present findings indicate that, among the protocols, training on a declined treadmill was found to induce changes of a more regenerative nature, seemingly indicating a better tissue restructuring after the suspension procedure.
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Five hemocyte types were identified in the hemolymph of Panstrongylus megistus by phase contrast and common light microscopy using some histochemical methods. These are: Prohemocytes, small cells presenting a great nucleus/cytoplasm ratio; Plasmatocytes, the most numerous hemocytes, are polymorphic cells mainly characterized by a large amount of lysosomes; Granulocytes, hemocytes very similar to plasmatocytes which contain cytoplasmic granules and are especially rich in polysaccharides; Oenocytoids, cells presenting a small nucleus and a thick cytoplasm; they show many small round vacuoles when observed in Giemsa smears and many cytoplasmic granules under phase microscopy; Adipohemocytes, very large hemocytes, presenting many fat droplet inclusions which could correspond to free fat bodies which entered the hemolymph. Only prohemocytes and plasmatocytes can be clearly classified; all the other hemocyte types have a more ambiguous classification.
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Nitric oxide synthase (NOS) has been reported to be involved with both bone healing and bone metabolism. The aim of this study was to test the null hypothesis that there is no correlation between new bone formation during mandibular distraction osteogenesis and NOS expression in the trigeminal ganglion of rats. Newly formed tissue during distraction osteogenesis and trigeminal NOS expression measured by the NADPH-diaphorase (NADPH-d) reaction were evaluated in 72 male Wistar rats by histomorphometric and histochemical methods. In animals submitted to 0.5 mm/day distraction osteogenesis, the percentage of bone tissue was higher in the basal area of the mandibles compared with the center and significantly increased through the experimental periods (P < 0.05). At the sixth postoperative week, the difference in bone formation between the continuous and acute distraction osteogenesis groups was the highest. Significant correlation between new bone formation by distraction osteogenesis and NADPH-d-reactive neurons was found, varying according to neuronal cell size (r = -0.6, P = 0.005, small cells strongly stained; r = 0.5, P = 0.018, large cells moderately stained). The results suggest that NOS may play a role in the bone healing process via neurogenic pathways, and the phenomenon seems to be neuronal cell morphotype-dependent. Further studies are now warranted to investigate the mechanistic link between the expression of trigeminal NOS and mandibular new bone formation by distraction osteogenesis.
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Calomys callosus is a wild, native forest rodent found in South America. In Brazil, this species has been reported to harbour the parasitic protozoan Trypanosoma cruzi. The ganglionated plexus of this species was studied using whole-mount preparations of trachea that were stained using histological and histochemical methods. The histological methods were used to determine the position of the ganglia with respect to the trachea muscle and to determine the presence of elastic and collagen fibers. The histochemical method of NADH-diaphorase was used for morphometric evaluations of the plexus. The tracheal plexus lies exclusively over the muscular part of the organ, dorsal to the muscle itself. It varies in pattern and extent between animals. The average number of neurons was 279 and the cellular profile area ranged from 38.37 mu m(2) to 805.89 mu m(2). Acetylcholinesterase (AChE) histochemistry verified that both ganglia and single neurons lie along nerve trunks and are reciprocally interconnected with the plexus. Intensely AChE-reactive neurons were found to be intermingled with poorly reactive ones. Two longitudinal AChE-positive nerve trunks were also observed and there was a diverse number of ganglia along the intricate network of nerves interconnecting the trunks. A ganglion capsule of collagen and elastic fibers surrounding the neurons was observed. Under polarized light, the capsule appeared to be formed by Type I collagen fibers. (C) 2008 Elsevier B.V. All rights reserved.
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The leaf infrastructure of five Xyris species were examined using scanning electron microscope (SEM), transmission electron microscope (TEM) and histochemical methods. All studied leaves show some features in epidermis and mesophyll, which were of considerable adaptative significance to drought stress. Such features included the occurrence of a pectic layer on the stomatal guard cells and the presence of a nehvork ofpectic compounds in the cuticle. Pectic compunds were also in abundance in lamellated walls of the mesophyll cells and on the inner surface of the sclerified cell walls of the vascular bundle sheaths. There were also specialized chlorenchymatous peg cells in the mesophyll and drops of phenolic compounds inside the epidermal cells.
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Studies of sub-lethal effects of pesticide residues on stingless bees are scarce and morphological analysis of organs would add information to toxicological analysis in order to clarify the continuous exposure of Scaptotrigona postica to insecticides. The aim of this study was to evaluate the morphology and histochemistry of the Malpighian tubules (excretory organ) of S. postica exposed to fipronil or boric acid to detect cellular responses that indicate toxicity or adaptative mechanisms to stress induced by exposure of worker bees to low doses of these chemical compounds. Newly emerged bees were submitted to toxicological bioassays and morphological analyses by optical microscopy and Transmission Electron Microscopy, as well as histochemical methods, were performed to detect proteins and glycoconjugates. Additionally, immunohistochemical detection of DNA fragmentation and HSP70 (70-kDa Heat shock protein) were performed to detect cell death and stress response, respectively. Statistical analysis, for the bioassays conducted with ingestion of contaminated diet with boric acid at 0.75% (w/w) or with fipronil at 0.1μg/kg of food, showed that the survival of bees that ingested the contaminated diets were significantly different to the survival rate presented by the control group (P<0.0001). Although some characteristics indicative of initiation of cell death were observed, the cells remained metabolically active in the processes of excretion and inactivation of chemical compounds. The data from this study reinforce the importance of research on sublethal effects of low doses of pesticides on bees in an attempt to assess a possible realistic dose and evaluate the risk assessment of stingless bee S. postica foraging in the vicinity of cultivated fields and/or in green urban areas. © 2013 Elsevier Ltd.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Pós-graduação em Medicina Veterinária - FCAV
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The specific transporters involved in maintenance of blood pH homeostasis in cephalopod molluscs have not been identified to date. Using in situ hybridization and immuno histochemical methods, we demonstrate that Na+/K+-ATPase (soNKA), a V-type H+-ATPase (soV-HA), and Na+/HCO3- cotransporter (soNBC) are co-localized in NKA-rich cells in the gills of Sepia officinalis. mRNA expression patterns of these transporters and selected metabolic genes were examined in response to moderately elevated seawater pCO2 (0.16 and 0.35 kPa) over a time-course of six weeks in different ontogenetic stages. The applied CO2 concentrations are relevant for ocean acidification scenarios projected for the coming decades. We determined strong expression changes in late stage embryos and hatchlings, with one to three log2-fold reductions in soNKA, soNBCe, socCAII and COX. In contrast, no hypercapnia induced changes in mRNA expression were observed in juveniles during both short- and long-term exposure. However a transiently increased demand of ion regulatory demand was evident during the initial acclimation reaction to elevated seawater pCO2. Gill Na+/K+-ATPase activity and protein concentration were increased by approximately 15% in during short (2-11 day), but not long term (42 day) exposure. Our findings support the hypothesis that the energy budget of adult cephalopods is not significantly compromised during long-term exposure to moderate environmental hypercapnia. However, the down regulation of ion-regulatory and metabolic genes in late stage embryos, taken together with a significant reduction in somatic growth, indicates that cephalopod early life stages are challenged by elevated seawater pCO2.
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Teeth, with their high mineralisation, incremental growth, and lack of remodelling, serve as biological archives that document an individual's development. This project aims to utilise the potential of teeth in bioarchaeological studies to achieve three primary objectives: 1) to investigate the application of histological and histochemical methods in reconstructing developmental bio-chronologies and early life histories; 2) to refine the temporal precision of isotopic analysis of dentine collagen by developing a novel protocol that integrates micro-sampling techniques with high-resolution histomorphometrics; and 3) to synthesise data from enamel and dentine for a comprehensive understanding of early life development and dietary transitions. This study adopts an integrated multidisciplinary bioarchaeological approach, conducting histomorphometric analysis on enamel and dentine across deciduous and permanent dentitions. It applies high-temporal resolution trace element analysis to enamel using LA-ICPMS and δ13C and δ15N isotope analyses through sequential micro-sampling to dentine of permanent teeth. Samples were selected from diverse archaeological contexts across the Italian peninsula, covering the Upper Palaeolithic, Copper Age, and Early Medieval periods, providing insight into diachronic variations in infant development and life history. Findings highlight the efficacy of histological and histochemical techniques in accurately determining growth rates, physiological stress, dietary shifts (particularly timing of weaning), and age at death in infant remains. The consistency and comparison between enamel and dentine underscores the enhanced insight obtained from integrating information from both tissues. Importantly, the newly proposed protocol significantly improves the temporal accuracy of dentine collagen analysis, facilitating precise chronological placement of the results over broad developmental associations. This study reaffirms the significance of teeth as valuable bioarchaeological instruments. By introducing and testing multidisciplinary methods, it provides deeper insights into early life history and cultural practices across diverse chronological contexts, highlighting the importance of advanced methodologies in extracting detailed, accurate, and nuanced information from past populations.