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Methods for the Morphological Study of Tracheal and Bronchial Glands
Published in Joan Gil, Models of Lung Disease, 2020
The presence of both neutral and acid glycoproteins has been demonstrated in the secretory cells of the submucosal glands. Of the various staining techniques available, the periodic acid-Schiff (PAS) and alcian blue (AB) techniques are much used; PAS is used to demonstrate the presence of neutral glycoprotein and AB for acid glycoprotein. Alcian blue, used at pH 2.6, stains both sialic acid and sulfate radicals bright blue. The control of AB staining, by varying the pH between 0.5 and 2.6, has been found by Jones and Reid (1973a, 1973b) to be satisfactorily selective, differentiating between sialo- and sulfomucin. With a combination of AB (pH 2.6) and PAS stains, mucous cells stain blue for acid glycoprotein. The mucous cells of the human tracheobronchial glands have been shown by Lamb and Reid (1972) to produce four groups of acid glycoprotein: sialomucin susceptible to sialidase; sialomucin resistent to sialidase; a sulfate identified by AB staining after acid hydrolysis (which removes all the sialomucin) but that is not stained by stains specific for sulfate; and a sulfate that stains after hydrolysis and stains with the specific stains for it. Ferret tracheal glands develop from intraepithelial cellular aggregates devoid of secretory granules at birth into complex, submucosal tubuloacinar structures composed predominantly of cells containing nonacidic (staining with PAS but not AB) secretory granules at 28 days (Leigh et al., 1986b), and thereafter acidic histochemical staining properties increase in secretory cells (Leigh et al., 1986a).
Laboratory Procedures and Management
Published in Jeremy R. Jass, Understanding Pathology, 2020
The early attempts at tissue staining were achieved by trial and error using natural dyes that had been available and in use for centuries, if not millennia, for dying fabrics. Leeuwenhoek (1632–1723) applied saffron solution to preparations of muscle fibres. By the end of the nineteenth century, the most popular stain for tissue sections was carmine derived from cochineal (Mayer, 1892). Cochineal is a red dye prepared from the dried female bodies of a scale insect, Dactylopius coccus. It was known to the Aztecs, the ancient Romans and apparently in biblical times since the Divinity exhorted Moses to prepare offerings of rams’ skins dyed red (Exodus 25:5). Orcein, known originally as French purple, dates from the 1300s (AD) when it was prepared from an extract of lichen (a primitive plant that is part fungus and part alga) that was exposed to air in the presence of ammonia formed in fermented urine (Conn, 1948). Orcein is still used for staining various tissue components, but thankfully is now prepared differently. Haematoxylin is derived from the wood of a tree called Haematoxylon campechianum, so named because it originated in the Mexican State of Campeche. Synthetic dyes, for example alcian blue developed by ICI, have also been used to stain cell products.
Ultrastructure of the Uterine Cervix
Published in Gabor Huszar, The Physiology and Biochemistry of the Uterus in Pregnancy and Labor, 2020
The endocervical canal is lined by a single-layered columnar epithelium which secretes mucus and invaginates the underlying stroma forming numerous blind, tunnellike collaterals. The columnar mucinous cells have basally placed nuclei and tall, uniform, finely granular cytoplasm filled with mucous droplets. Some of these react strongly with alcian blue stains, whereas others were stained with periodic acid Schiff reagent which highlighted their sulfated, sialic acid and neutral mucopolysaccharide content, respectively.20 Nonsecretory cells with cilia5 intermingle with mucinous cells.3 The main function of endocervical cilia is to facilitate the distribution and mobilization of endocervical mucus. The morphologic alterations in the endocervical cells during the menstrual cycle are subtle. However, cellular growth and secretory activity peak at the time of ovulation.
Tensile Viscoelastic Properties of the Sclera after Glycosaminoglycan Depletion
Published in Current Eye Research, 2021
Hamed Hatami-Marbini, Mohammad Pachenari
The thickness of the strips in the control and No GAG group was 1.23 ± 0.13 mm and 1.25 ± 0.11 mm, respectively; these values are in agreement with those reported previously for porcine disks obtained from a similar region.29 The DMMB assay showed an about 88% decrease in GAG content because of the digestion process. The GAG content of samples in the control and No GAG groups was 6.39 ± 0.55 µg/mg and 0.79 ± 0.17 µg/mg, respectively. It is known that GAGs appears blue to bluish-green after staining with the Alcian blue. Figure 2a shows that GAGs existed throughout a typical scleral sample that was treated in buffer solution. However, Figure 2b shows that staining of Alcian blue was barely visible in a sample treated by the enzyme solution, i.e. the concentration of GAGs was significantly reduced in the samples treated with the enzyme.
Real-time quantitative monitoring of in vitro nasal drug delivery by a nasal epithelial mucosa-on-a-chip model
Published in Expert Opinion on Drug Delivery, 2021
Hanieh Gholizadeh, Hui Xin Ong, Peta Bradbury, Agisilaos Kourmatzis, Daniela Traini, Paul Young, Ming Li, Shaokoon Cheng
The mucus production of the ALI nasal epithelium grown in the NEM-on-a-chip was determined at days 7, 14, and 21 post-seeding as described previously [14,28]. Briefly, the NEM-on-a-chip samples were fixed by injecting 4% w/v paraformaldehyde into the top and bottom compartments and incubation for 20 min. Both compartments were then washed with PBS. To stain the mucopolysaccharides present in mucin, Alcian blue (1% in 3% acetic acid, pH 2.5; Sigma Aldrich, Australia) was injected into the top compartment. After 15 min, the top compartment was washed with PBS to remove the excess stain. The device was then air-dried for 3 hours. The top and bottom PDMS films of the NEM-on-a-chip were gently separated using a scalpel and the membrane was removed and mounted onto a microscopic glass slide with mounting medium and sealed. Mucus images were taken using a NanoZoomer-SQ Digital Slide Scanner (Hamamatsu Photonics, Japan) and analyzed using ImageJ software (v1.52a), where the intensity of blue stains was calculated as
Responsiveness of α2-adrenoceptor/I1-imidazoline receptor in the rostral ventrolateral medulla to cardiovascular regulation is enhanced in conscious spontaneously hypertensive rat
Published in Clinical and Experimental Hypertension, 2019
Masanobu Yamazato, Minori Nakamoto, Atsushi Sakima, Yoriko Yamazato, Shuichi Takishita, Yusuke Ohya
At the end of the experiments, the rats were anesthetized with sodium pentobarbital. The injection site was marked by injecting 200 nL of Alcian blue dye. The rats were then perfused transcardially with 50 mL of 0.9% sodium chloride and then with 100 mL of 10% phosphate-buffered formalin. The brainstem was removed and stored in 10% phosphate-buffered formalin. On the day prior to sectioning of the brain tissue, the brainstem was transferred to phosphate buffer containing 20% sucrose. The frozen brain tissues were sectioned in the coronal plane (50 µm). The microinjection sites were identified by the deposition of Alcian blue dye and then correlated to the anatomical structures of the rat medulla oblongata, according to the atlas (17). Rats in which Alcian blue dye had permeated to the ventral surface or those who showed apparent bleeding were excluded from the analysis.