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Histochemical Techniques (histochemical + techniques)
Selected AbstractsHistochemical localization of secretion and composition of the essential oil in Melittis melissophyllum L. subsp. melissophyllum from Central ItalyFLAVOUR AND FRAGRANCE JOURNAL, Issue 2 2010Filippo Maggi Abstract The distribution and morphology of the secretory structures in Melittis melissophyllum L. subsp. melissophyllum (Lamiaceae) were studied for the first time by light and scanning electron microscopy. The indumentum of the vegetative and reproductive organs includes non-glandular hairs and peltate (type A) and capitate (types B and C) glandular trichomes. Histochemical techniques enabled specific location of the site of essential oil accumulation in the type A peltate hairs. In order to confirm the occurrence of the 1-octen-3-ol chemotype in central Italy, six populations growing in different places were analysed for the essential oil composition by GC,FID and GC,MS. In all populations, 1-octen-3-ol was detected as the major volatile component, representing 56.3,70.6% of the total oils. To date, these percentages are the highest detected in a plant essential oil. Copyright © 2009 John Wiley & Sons, Ltd. [source] Ultrastructural and histochemical study of the salivary glands of Aplysia depilans (Mollusca, Opisthobranchia)ACTA ZOOLOGICA, Issue 3 2001Alexandre Lobo-da-Cunha Abstract The digestive system of the sea hare, Aplysia depilans, includes a pair of ribbon-shaped salivary glands. A central duct and a large blood vessel run close to each other along the length of these glands and both are surrounded by a layer of muscle cells. Three cell types form the glandular epithelium: granular cells, vacuolated cells and mucocytes. The granular cells possess cilia and spherical secretion granules, located primarily in the apical region. The granules of immature cells have a low electron density and are mainly formed by neutral polysaccharides with small amounts of proteins. The granules of mature cells are larger, have a high electron density and are mainly formed by proteins with lower amounts of neutral polysaccharides. Transition stages between immature and mature granular cells are observed. The vacuolated cells are large and frequently pyramidal in shape, but after the application of histochemical techniques almost all vacuoles remain uncoloured. The numerous vacuoles contain flocculent material in a clear background and the mitochondria possess large crystalline structures in the matrix. A pyramidal shape is also typical of the mucocytes, which are filled with vesicles containing granular masses surrounded by a network of secretion material. These large cells are strongly stained by Alcian blue, revealing the presence of acidic mucopolysaccharides. This is the first ultrastructural study of the salivary glands in opisthobranch gastropods. [source] Synthesis and preliminary biological evaluation of a 99mTc-labeled hypericin derivative as a necrosis avid imaging agentJOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 1 2008Humphrey Fonge Abstract Mono-[123I]iodohypericin and mono-[123I]iodohypericin monocarboxylic acid are iodine-123-labeled hypericin derivatives which have shown great promise in preclinical studies as necrosis avid imaging agents in animal models of infarction. In view of the more attractive properties of a 99mTc-labeled hypericin derivative, we have synthesized a conjugate of protohypericin monocarboxylic acid with S -benzoylmercaptoacetyldiglycyl-diaminopentane in an overall yield of 15%. The conjugate was labeled with technetium-99m by exchange labeling at pH 10 in a labeling yield of 95% followed by photocyclization to yield 99mTc-mercaptoacetyldiglycyl-1,5-diaminopentylene hypericincarboxamide (99mTc-13). The negatively charged 99mTc-13 complex was purified by reversed phase high-pressure liquid chromatography and the log,P7.4 was determined to be 2.36. In normal NMRI mice, the complex showed slow hepatobiliary clearance while plasma clearance was rapid. The tracer was evaluated in rats with reperfused hepatic infarction by ex vivo autoradiography, gamma counting and histochemical techniques. Unlike the radioiodinated hypericin derivatives, the new tracer agent did not show preferential uptake in necrotic tissue on autoradiography and gamma counting techniques. Conjugation of hypericin with a 99mTc-chelate, resulting in a change in size, charge and lipophilicity, had a profound effect on the necrosis avidity of the tracer agent. The results show that 99mTc-13 is not suitable for imaging necrosis. Copyright © 2008 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] Microscopic analysis and seasonality of gemma production in the freshwater red alga Hildenbrandia angolensis (Hildenbrandiales, Rhodophyta)PHYCOLOGICAL RESEARCH, Issue 4 2000Alison R. Sherwood SUMMARY The development and release of the unique vegetative propagules of the freshwater encrusting alga Hildenbrandia angolensis Welwitsch ex West et West, gemmae, were studied using several different microscopic and histochemical techniques. In addition, the seasonality of gemma production was monitored bimonthly over a 12-month period in two spring-fed streams in Texas, USA. Gemmae differentiate within the thallus and are subsequently released from the surface of the crust. Release of the gemmae most likely occurs by digestion of surrounding cells, as suggested by the presence of starch granules and lipid globules in the region between the released gemma and the thallus. The initial separation of the gemmae from the thallus occurs from the sides of the gemma or the bottom, or possibly simultaneously. Contrary to previous studies, we have observed that gemma production occurs endogenously within the thallus of freshwater Hildenbrandia, rather than on the surface of the crust in raised structures. Histochemical tests and electron microscopic examination indicate that the cells of the gemmae contain a large amount of floridean starch. The starch granules frequently form rings surrounding the nuclei of both gemma and thallus cells; a feature infrequently reported for florideophyte red algae. Our seasonality investigations indicate that large fluctuations in gemma production occur over 1 year, but at least some gemma production continues year-round in the streams examined. [source] | |||||||||||||