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Histochemical Localization (histochemical + localization)

Distribution by Scientific Domains

Medical Sciences	50%

Selected Abstracts

Histochemical localization of secretion and composition of the essential oil in Melittis melissophyllum L. subsp. melissophyllum from Central Italy

FLAVOUR AND FRAGRANCE JOURNAL, Issue 2 2010
Filippo 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]

Assessment of carcinogenic potential of repeated fish fried oil in mice

MOLECULAR CARCINOGENESIS, Issue 10 2006
Manoj K. Pandey
Abstract Our prior studies have shown that single topical treatment of repeated fish fried oil extract (RFFE), containing various polycyclic aromatic hydrocarbons (PAHs), to the dorsal epidermis of mice caused enhancement of DNA damage along with higher expression of p53 and p21WAF1 proteins and cell-cycle arrest. In the present study carcinogenic potential of repeated fish fried oil (RFFO) and RFFE was assessed. Single topical application of RFFO (100 µL/animal) and RFFE (100,500 µg/animal) to Swiss albino female mice resulted in significant induction (1.8- to 7.4-fold) of ornithine decarboxylase activity. Twice weekly topical application of methylcholanthrene (MCA) for 24 wk or single topical application of 7,12-dimethylbenzanthracene (DMBA) or RFFO or RFFE, as initiator followed by twice weekly application of 12-O-tetradecanoyl phorbol myristate acetate (TPA) as promoter for 24 wk, resulted in development of skin papillomas after 6, 7, 18, and 9 wk, respectively. The cumulative number of tumors in MCA, DMBA/TPA, RFFE (200 µg)/TPA, and RFFE (500 µg)/TPA groups were 276, 168, 34, and 58 after 24 wk while negligible or minimal initiating activity was noticed in RFFO/TPA group. No tumors were found in animals either given twice weekly topical application of RFFO or a single initiating dose of DMBA followed by twice weekly application of RFFO. Histopathology of skin of animals treated with RFFE/TPA showed marked proliferation of epidermal layers along with abnormal mitosis and multinucleated tumor appearance. Skin of animals in groups RFFO/TPA and DMBA/RFFO showed sloughing and regeneration of epidermal layers, oedema along with proliferation of fibroblasts. Histochemical localization of ,-glutamyl transpeptidase was found to be substantially higher in skin of mice treated with RFFO/TPA and RFFE/TPA. Animals treated with RFFO/TPA, DMBA/RFFO, and RFFE/TPA resulted in significant induction of cutaneous aryl hydrocarbon hydroxylase (AHH) (421,432%), ethoxyresorufin-O-deethylase (252,316%), and glutathione S-transferase (133,245%) activities. Animals treated with RFFO/TPA, DMBA/RFFO, and RFFE/TPA led to significant reduction in glutathione content (39,44%) with a concomitant increase in lipid peroxidation (254,492%). Animals treated with RFFO/TPA and RFFE/TPA led a significant decrease in catalase (43,69%) and superoxide dismutase (20,31%) activities while glutathione reductase activity was found to be diminished (23,51%) in RFFO, RFFO/TPA, DMBA/RFFO, and RFFE/TPA treated groups. These results suggest that RFFE possess skin tumor initiating activity and that it may have weak promoting activity as well, which may involve free radicals. © 2006 Wiley-Liss, Inc. [source]

Ultrastructural and immunocytochemical characterization of immortalized odontoblast MO6-G3

INTERNATIONAL ENDODONTIC JOURNAL, Issue 6 2006
C. Mesgouez
Abstract Aim, To investigate an immortalized murine odontoblast cell line as a potential alternative for experimental studies on dentinogenesis. Methodology, The MO6-G3 cell line was investigated morphologically over 3, 7, 11 and 42 days of culture, using histochemical localization of dentine sialoprotein (DSP), alkaline phosphatase (AP), type I collagen and actin filaments, histoenzymatic staining and biochemical investigation of AP and finally, transmission and scanning electron microscopy. Results, Scanning electron micrographs showed elongated cells. Accordingly, a polarized organization of odontoblasts was observed by transmission electron microscopy, identifying distinct subcellular compartments as described in vivo. The secretion apparatus, which includes cisternae of rough endoplasmic reticulum, Golgi apparatus saccules and secretion vesicles and granules, was longitudinally organized in the supranuclear compartment ending distally in the secretory pole. A cellular process was observed. The investigation of the cytoskeleton network revealed that actin microfilaments were organized in parallel stress fibre oriented depending on the longitudinal axis of the cytoplasm. Immunofluorescent labelling showed a continuous expression of type I collagen, DSP and AP. A unipolar distribution characterized intracellular DSP immunoreactivity. Histoenzymology revealed AP active sites increasing from 3 to 11 days albeit with a moderate level of activity comparatively to the in vivo situation in dental cells. Conclusion, This cell line MO6-G3 not only showed the criteria of odontoblast phenotype as previously reported but also the characteristic morphodifferentiation pattern of polarized odontoblasts at the cellular level but with an apparent random distribution. [source]

A method for the histochemical localization of digestive enzymes in whole freeze-substituted larval fish embedded in glycol methacrylate

AQUACULTURE RESEARCH, Issue 7 2009
Grant W Vandenberg
Abstract In order to study the localization of digestive enzymes in larval walleye (Sander vitreus vitreus), a novel method of low-temperature processing of whole, unfixed larvae and subsequent embedding in glycol methacrylate (GMA) was developed. Larval walleye aged 2,10 days post hatch were flash-frozen in liquid nitrogen and transferred into pre-chilled acetone for 12 h at a temperature of ,25 °C. Acetone was gradually replaced with increasing concentrations of GMA resin monomer over a 6-h period. The polymer (100%) was further allowed to infiltrate the larvae for 36 h. Resin-embedded larvae were transferred to embedding moulds and polymerized overnight at ,25 °C. Four micrometre sections were stained to identify either alkaline phosphatase, non-specific esterase, aminopeptidase M or dipeptidyl peptidase IV. All enzymes studied were readily detected and accurately localized, and no enzyme diffusion was observed. Therefore, freeze substitution combined with low-temperature GMA embedding allows the maintenance of excellent tissue morphology and accurate enzyme localization in whole larval walleye specimens from 2 to 10 days post hatch. It is recommended, however, that samples be frozen in pre-cooled fluorocarbon-based liquid coolants in order to assure optimal tissue preservation. [source]