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Periodic Acid Schiff (periodic + acid_schiff)
Selected AbstractsTinctorial Properties of Zygomycosis in Cutaneous Biopsy SpecimensJOURNAL OF CUTANEOUS PATHOLOGY, Issue 1 2005A. Rubin It is a little known fact that the organisms causing Zygomycosis are often better visualized with routine Hematoxylin and Eosin (H and E) staining than Periodic Acid Schiff (PAS) staining. Experienced dermatopathologists, when evaluating histologic samples suspected of harboring deep fungal infection often rely more heavily on PAS staining to detect fungi. The diagnosis of Zygomycosis may be delayed or missed entirely if sufficient attention is not devoted to the H and E stained specimen. A review of multiple dermatopathology textbooks shows there is no universal agreement on the usefulness of routine H and E staining versus use of special stains for the detection of Zygomycosis. Grocott's Methanamine Silver (GMS) staining can give false negative results if background staining of reticulum fibers is enhanced. This can occur because of overexposure in silver solution, excessive heat during processing, or use of incorrectly titrated solutions. Three consecutive culture proven cases of cutaneous Zygomycosis infection were evaluated. In each case, organisms were clearly visualized on routine H and E sections while PAS staining was variable. Examples of false negative GMS staining are also shown. Recognition of these staining properties can help dermatopathologists better detect the agents of Zygomycosis. [source] Psoriasis under the microscopeJOURNAL OF THE EUROPEAN ACADEMY OF DERMATOLOGY & VENEREOLOGY, Issue 2006BJ Cribier Abstract Histopathology is a major diagnostic tool in dermatology, particularly in psoriasiform diseases. Morphological studies showed that the initial event in psoriatic lesions is perivascular infiltrate, followed by dilatation of superficial papillary vessels. Proliferation of keratinocytes and neutrophil exocytosis are secondary events. Fully developed psoriasis has a very characteristic pattern, which includes elongation of rete ridges leading to regular acanthosis, oedema of the papillary dermis associated with tortuous dilated vessels, thinning of suprapapillar area, decreased thickness of granular layer, and exocytosis of neutrophils in the spinous layer (Kogoj's pustule) or in the cornified parakeratotic layer (Munro microabscesses). Pustular psoriasis is characterized by large or confluent intra-epidermal multilocular pustules. Whatever the clinical variant of psoriasis, common morphological signs suggest that it is basically a unique pathological process, with many possible presentations according to various factors such as age, size and localization of lesions, or therapy. Similar microscopic elementary lesions indicate that Hallopeau's acrodermatitis continua, Reiter's disease and geographical tongue are variants of psoriasis. Because of the many faces of the disease, psoriasis can resemble many other squamous or pustular disorders. Differential diagnosis by microscopic analysis is based on pattern analysis, PAS (Periodic Acid Schiff) staining to rule out fungal infection, and immunohistochemistry to characterize lymphocytic infiltrate. Psoriasis is one of the most common inflammatory skin diseases. In its characteristic presentation, psoriasis comprises well-circumscribed red scaly papules and plaques. In this form, the disease is generally easy to identify, especially when the elbows, knees and scalp are affected. Nevertheless, the term ,psoriasis' includes more clinical variants than any other inflammatory dermatosis: psoriasis vulgaris vs. pustular, localized vs. generalized, topographic variants, mucous membranes involvement, hair and nail lesions. Although some of these conditions might be extremely different from psoriasis vulgaris, common pathological findings can be identified in all of them. Microscopic analysis of psoriatic lesions may therefore help clinicians to make the diagnosis and to understand that, whatever the clinical presentation, signs and symptoms are mainly due to a unique pathological process. [source] Light and Electron Microscopic Studies of the Trachea in the One-Humped Camel (Camelus dromedarius)ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 1 2007A. R. Raji Summary Histology of trachea of camel (Camelus dromedarius) was studied using light, scanning (SEM) and transmission electron microscopy (TEM). Tissue samples taken from the trachea (proximal, middle and distal part) were routinely prepared for histology (LM, EM) and stained with haematoxylin and eosin, Van Giesson (VG), Alcian blue, Periodic acid schiff (PAS), Masson's trichrome (MT), Verhof, PAS,VG and PAS,MT. The trachea of camel consists of 66,75 incomplete cartilaginous rings of hyaline. The lamina epithelium is composed of pseudostratified-ciliated columnar epithelium with many goblet cells. Submucosal layers were loose connective tissue with many elastic fibres. The mucosal and submucosal layers were 517.2 ± 61.6 ,m (n = 20) thick. Submucosal glands were tubuloalveolar with mucous (acidic and neutral) secretions. Trachealis muscle was attached to the inside sheet of tracheal cartilage. Ultrastructural studies showed that surface epithelium is pseudostratified with mucus-producing goblet cells, ciliated and basal cells, similar to other mammals. The ciliated cells contained many mitochondria, oval nucleus and many big granules. In scanning electron microscopy (SEM) studies, viscoelastic layers were observed on the epithelial surface of trachea, and there were highly condensed cilia under this layer. [source] Juvenile hyaline fibromatosis: a case report and review of the literatureINTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 11 2004Jean E. Thomas MD Background, Juvenile hyaline fibromatosis (JHF) is a rare, inherited condition characterized by tumor-like growth of hyalinized fibrous tissue on the head and neck, joint contractures, and gingival hypertrophy. There may be marked clinical heterogeneity. Methods, We present a case of a 3-year-old Haitian boy with multiple firm nodules on the scalp and chin without joint contractures or gingival hypertrophy. Family history was not available. Results, Biopsy specimens from three scalp nodules were processed with routine and immunohistochemical stains. The matrix was periodic acid Schiff (PAS) and Alcian blue positive. The cellular stromal component was positive for vimentin and scattered factor XIIIa positive cells were found. Osteoclast-like giant cells were also noted, and stained for CD68. Conclusions, Our patient had the nodular growths on the scalp and face that are characteristically found in JHF. Microscopic examination confirmed the diagnosis and showed scattered intracytoplasmic and extracellular eosinophilic globules in three separate biopsy specimens. These were positive with PAS. [source] Effect of long-term application of epinephrine on rat skin vasculature: Experimental studyMICROSURGERY, Issue 7 2002Ercan Karacao, lu M.D. As a potent vasoconstrictor, epinephrine is used ubiquitously in plastic surgery. It is typically delivered subcutaneously in very low concentrations over a brief time interval. We are aware of no reports describing the long-term release of epinephrine as an independent agent to the soft tissues for the purpose of causing prolonged local vasoconstriction. This study was designed to address two goals: first, to investigate the effect of long-term local release of epinephrine from a drug delivery system on rat abdominal skin vasculature; secondly, to evaluate the pharmacological properties of this drug delivery system (DDS). Thirty male Sprague-Dawley rats, weighing 300,400 g, were included in the study. Animals were subdivided into two groups of 15 each. Group A (control group) and Group B (experimental group) were treated with saline and epinephrine-loaded microspheres (msps), respectively. The manufacturing process and formulation studies of the DDS are described. In vivo assays revealed a 7-day sustained release of epinephrine. After 7 days, neither residual nor supraphysiologic release of epinephrine was shown with high-performance liquid chromatography (HPLC). Histological studies with hematoxylin-eosin and periodic acid Schiff revealed a statistically significant increase in number of vessels as well as their diameter and wall thickness (P <0.05). Epinephrine release via this msp/DDS predictably induces local vasoconstriction over a time sequence known to be optimally associated with hypoxia and promotion of vascular augmentation. This model can be valuable in sustaining hemostasis during long-lasting (more than a few hours) surgical procedures by its long-acting vasoconstructive effect. The system's ability to intentionally cause vascular augmentation also bodes great potential in flap and graft surgery. © 2002 Wiley-Liss, Inc. MICROSURGERY 22:288,294 2002 [source] Quantitative MRI-pathology correlations of brain white matter lesions developing in a non-human primate model of multiple sclerosisNMR IN BIOMEDICINE, Issue 2 2007Erwin L. A. Blezer Abstract Experimental autoimmune encephalomyelitis (EAE) induced with recombinant human myelin/oligodendrocyte glycoprotein in the common marmoset is a useful preclinical model of multiple sclerosis in which white matter lesions can be well visualized with MRI. In this study we characterized lesion progression with quantitative in vivo MRI (4.7,T; T1 relaxation time,±,Gd-DTPA; T2 relaxation time; magnetization transfer ratio, MTR, imaging) and correlated end stage MRI presentation with quantitative ex vivo MRI (formaldehyde fixed brains; T1 and T2 relaxation times; MTR) and histology. The histopathological characterization included axonal density measurements and the numeric quantification of infiltrated macrophages expressing markers for early active [luxol fast blue (LFB) or migration inhibition factor-related protein-14 positive] or late active/inactive [periodic acid Schiff (PAS) positive] demyelinating lesion. MRI experiments were done every two weeks until the monkeys were sacrificed with severe EAE-related motor deficits. Compared with the normal appearing white matter, lesions showed an initial increase in T1 relaxation times, leakage of Gd-DTPA and decrease in MTR values. The progressive enlargement of lesions was associated with stabilized T1 values, while T2 initially increased and stabilized thereafter and MTR remained decreased. Gd-DTPA leakage was highly variable throughout the experiment. MRI characteristics of the cortex and (normal appearing) white matter did not change during the experiment. We observed that in vivo MTR values correlated positively with the number of early active (LFB+) and negatively with late active (PAS+) macrophages. Ex vivo MTR and relaxation times correlated positively with the number of PAS-positive macrophages. None of the investigated MRI parameters correlated with axonal density. Copyright © 2006 John Wiley & Sons, Ltd. [source] Posthatching development of Alligator mississippiensis ovary and testisJOURNAL OF MORPHOLOGY, Issue 5 2010Brandon C. Moore Abstract We investigated ovary and testis development of Alligator mississippiensis during the first 5 months posthatch. To better describe follicle assembly and seminiferous cord development, we used histochemical techniques to detect carbohydrate-rich extracellular matrix components in 1-week, 1-month, 3-month, and 5-month-old gonads. We found profound morphological changes in both ovary and testis. During this time, oogenesis progressed up to diplotene arrest and meiotic germ cells increasingly interacted with follicular cells. Concomitant with follicles becoming invested with full complements of granulosa cells, a periodic acid Schiff's (PAS)-positive basement membrane formed. As follicles enlarged and thecal layers were observed, basement membranes and thecal compartments gained periodic acid-methionine silver (PAMS)-reactive fibers. The ovarian medulla increased first PAS- and then PAMS reactivity as it fragmented into wide lacunae lined with low cuboidal to squamous epithelia. During this same period, testicular germ cells found along the tubule margins were observed progressing from spermatogonia to round spermatids located within the center of tubules. Accompanying this meiotic development, interstitial Leydig cell clusters become more visible and testicular capsules thickened. During the observed testis development, the thickening tunica albuginea and widening interstitial tissues showed increasing PAS- and PAMS reactivity. We observed putative intersex structures in both ovary and testis. On the coelomic aspect of testes were cell clusters with germ cell morphology and at the posterior end of ovaries, we observed "medullary rests" resembling immature testis cords. We hypothesize laboratory conditions accelerated gonad maturation due to optimum conditions, including nutrients and temperature. Laboratory alligators grew more rapidly and with increased body conditions compared with previous measured, field-caught animals. Additionally, we predict the morphological maturation observed in these gonads is concomitant with increased endocrine activities. J. Morphol. 2010. © 2009 Wiley-Liss, Inc. [source] | |||||||||||||