Histoarchitectural and Histoenzymatic Studies on Gizzard of Guinea Fowl (Numida meleagris)

Background: The gizzard is a muscular stomach of the Gastrointestinal tract of bird that holds sparing crystals which aids as the mechanical multure component for food material to be ingested by birds. Its specialty is to grinding of ingested food material after secretion of HCL (Hydrochloric Acid) and pepsinogen enzymes in the proventriculus. Methods: The twelve samples of gizzard of guinea fowl were fixed in 10% NBF (Neutral buffered formalin) and Bouin’s fluid for histological while chilled acetone and chilled ethanol for histochemical studies. The fresh unfixed tissues were used for the cryostat section for the demonstration of different enzymes.Result: The tubular glands were main feature of mucosal layer but sometime acinar glands also found as the replacement of tubular glands with lymphoid aggregation. The horizontal koilin was also noticed between long mucosal folds. Tunica submucosa was discovered in squeezed manner in comparison to the mucosa. The tunica muscularis has shown inner circular and outer longitudinal as the thick layer. It was intermingling with collagen and elastic fibers. Histochemically the gizzard was examined for glycogen, alkaline phosphatase, acid phosphatase and succinic dehydrogenase.

Quantification of Mycelium of Botrytis spp. and the Antagonist Ulocladium atrum in Necrotic Leaf Tissue of Cyclamen and Lily by Fluorescence Microscopy and Image Analysis

A technique was developed to localize and quantify the internal mycelial colonization of necrotic leaf tissue of cyclamen (Cyclamen persicum) or lily (Lilium) by pathogenic Botrytis spp. and the antagonist Ulocladium atrum. This technique allows investigation of competitive substrate colonization by both fungi, which is a key process for biological control of Botrytis spp. by U. atrum. A combination of differential fluorescent labeling and image analysis was applied on cryostat sections of necrotic leaf tissue. Botrytis mycelium was labeled specifically by indirect immunofluorescence using a monoclonal antibody specific for Botrytis spp. And an antimouse fluorescein conjugate. Wheat germ agglutinin conjugated to the fluorochrome TRITC was used to label mycelium of both fungi. Image analysis was used to measure the relative surface area of the cryostat section covered by fluorescing hyphae of Botrytis spp. and by fluorescing hyphae of both fungi. A mathematical conversion was derived and used to calculate the relative mycelial volume of each fungal species in the necrotic tissue based on the measured relative surface areas. Temporal aspects of substrate colonization were studied in a short time series. An analysis of components of variance provided insight into spatial colonization patterns for the fungal species involved and allowed the design of efficient sampling strategies for future experiments.

Combination of non-radioactive and radioactive in situ hybridization with immunohistochemistry: a new method allowing the simultaneous detection of two mRNAs and one antigen in the same brain tissue section.

We describe here a simple method for combining non-radioactive and radioactive in situ hybridization and immunohistochemistry on the same brain tissue section. This approach was first developed on the well-characterized hypothalamo-neurohypophyseal system, facilitating the optimization of the triple-labeling procedure and the verification of labeling specificity. We report the simultaneous detection of vasopressin (VP) mRNA with a digoxigenin-labeled oligonucleotide, oxytocin (OT) mRNA with a 35S-labeled oligonucleotide, and OT peptide in the same 12-microns cryostat section. This was performed on floating sections as follows: first, the two probes were hybridized simultaneously; second, the peptide was detected with an immunoperoxidase-DAB procedure; third, the digoxigenin-labeled probe was detected with an alkaline phosphatase-NBT/BCIP technique; and finally, the 35S-labeled probe was detected by histological autoradiography. We also demonstrate that this approach is suitable for the simultaneous detection of tyrosine hydroxylase and two less abundant mRNAs, vasoactive intestinal peptide and vasopressin mRNAs, in the suprachiasmatic nucleus. The combination of the three techniques did not significantly diminish their specificity or sensitivity. In conclusion, this new method, permitting the simultaneous detection of three different products of gene expression in the same section, could be useful for further analysis of the phenotypic organization and its plasticity in endocrine or neural tissues.

Autoradiographic Study of Regional Protein Synthesis in Focal Cerebral Ischemia with TCA Wash and Image Subtraction Techniques

The standard biochemical method of trichloracetic acid (TCA) wash and the image processing technique were combined to differentiate and visualize the distributions of polypeptide-incorporated and unincorporated tracers in an autoradiographic study of regional protein synthesis, The validity of applying TCA wash procedures to cryostat sections was considered by histologic and chemical evaluations, For the autoradiographic study of in vivo protein synthesis, a tracer dose of L-[14C]valine was administered 30 min after occlusion of the posterior communicating artery in gerbils. Images of total (polypeptide-incorporated and unincorporated) radioactivity and of polypeptide-incorporated radioactivity were obtained from an identical cryostat section before and after TCA wash. The polypeptide-unincorporated radioactivity image was produced with an image processing system by subtracting pixel by pixel the polypeptide-incorporated radioactivity from the total radioactivity. The present study clearly demonstrated that in spite of the sufficient delivery of tracer amino acids, the polypeptide synthesis was completely lost in the ischemic focus. Free tracer was markedly accumulated in the brain adjacent to the ischemic focus. This kind of autoradiographic technique seems to be indispensable in studying the topographical complexity of the altered protein metabolism in the pathologic brain.

Negative-staining autoradiography: a new technique for ultracryotomy utilizing an interposed film.

A new radiocytochemical technique is reported for ultrastructural localization of diffusible substances, using negatively stained ultra-cryostat sections. A sheet of film interposed between the cryostat section and the emulsion layer has rendered negative-staining autoradiography (NSA) practical. The rationale of NSA is that the film completely shields the section from all moisture-producing autoradiographic processes, so that phosphotungstic acid (PTA) can stain the section either before or after autoradiography (ARG), without the possibility of ultrastructural damage by alkaline solutions, interference between PTA and photoprocessing compounds, and superimposed images of a gelatin layer stained with PTA. As a model to demonstrate the newly developed procedure of NSA, rat brains were labeled with [125I]-triiodothyronine, fixed with tannic fixative, immersed in a cryoprotectant, frozen in liquefied propane, and cryostat sectioned. The resulting higher yield of radioactivity (85%) on the section was confirmed by a radiation counter. The retention rate was approximately 20% greater than that of conventional sections. Developed silver grains were found on synaptic vesicles and mitochondria in the polymorphic layer of the dentate gyrus. In this report we will also discuss the problems associated with cryostat sectioning of fresh tissues, the concept of ARG resolution, the distribution pattern of developed silver grains, and the possible applications of NSA.

Combination of immunocytochemistry and in situ hybridization in the same tissue section of rat pituitary.

A procedure is described for combining avidin-biotinylated horseradish peroxidase immunocytochemistry, for localizing peptides or proteins, with in situ hybridization for localizing mRNA autoradiographically in the same cryostat section of paraformaldehyde-fixed rat pituitary. Protection against enzymatic degradation of target mRNAs during the immunocytochemical step was necessary and was accomplished by including an RNase inhibitor, 0.04% diethylpyrocarbonate, in primary and secondary antisera. This combination of methods may be useful in other tissues, as well, for (a) determining the relation of protein content to the concentration of its encoding mRNA, (b) proving the synthetic capacity of a cell in which a protein has been localized, (c) determining immunological or nucleic acid probe specificity, or (d) as an alternative to double-labeling immunocytochemical methods.