Confocal laser scanning microscopic analysis of ectopic sublingual gland‐like tissue inside the hamster submandibular gland

Based on its histochemical properties, the secretory portion of the hamster submandibular gland has been classified as seromucous cells. The presence of endogenous peroxidase (PO) reaction was shown in the nuclear envelope, cisternae of endoplasmic reticulum and Golgi apparatus. The 3,3′‐diaminobenzidene, tetrahydrochloride (DAB) method revealed bipartite secretory granules containing a PO‐positive dense core surrounded by a less dense halo in these cells. In the present investigation, serous and mucous‐like cells were found in resin‐embedded semi‐thin sections of the DAB‐reacted hamster submandibular gland. These sections were already on glass slides for routine light microscopic observations, therefore electron microscopic analysis could be unrealizable. We then used reflectance‐mode confocal laser scanning microscopy to visualize additional sites of PO activity as detected in these sections. Using this approach, we found mucous cells with PO activity‐negative secretory granules and seromucous cells with PO activity‐positive spot‐like secretory granules of the regular sublingual gland most frequently adjacent to the serous cells with typical electron‐dense secretory granules. These cells clearly differ from the seromucous cells with bipartite secretory granules and the granular duct cells with typical electron‐dense secretory granules of the hamster submandibular gland. Additionally, secretory endpieces of the ectopic sublingual gland‐like tissue empty into the duct of the hamster submandibular gland lobule. Thus, our findings suggest that a mass of sublingual gland tissue extends into the hamster submandibular gland during its development, and PO may be synthesized and secreted into the same duct. Microsc. Res. Tech. 76:1284–1291, 2013. © 2013 Wiley Periodicals, Inc.     

Light and transmission electron microscopic structure of skin glands and dermal scales of a caecilian amphibian Gegeneophis ramaswamii,with a note on antimicrobial property of skin gland secretion

Amphibian skin secretions contain a variety of bioactive compounds that are involved in diverse roles such as communication, homeostasis, defence against predators, pathogens, and so on. Especially, the caecilian amphibians possess numerous cutaneous glands that produce the secretory material, which facilitate survival in their harsh subterranean environment. Inspite of the fact that India has a fairly abundant distribution of caecilian amphibians, there has hardly been any study on their skin and its secretion. Herein, we describe, using light microscopy and electron microscopy, two types of dermal glands, mucous and granular, in Gegeneophis ramaswamii. The mucous glands are filled with mucous materials. The mucous‐producing cells are located near the periphery. The granular glands are surrounded by myoepithelial cells. A large number of granules of different sizes are present in the lumen of the granular gland. The granule‐producing cells are present near the myoepithelial lining of the gland. There are small flat disk‐like dermal scales in pockets in the transverse ridges of the posterior region of the body. Each pocket contains 1–4 scales of various sizes. Scanning electron microscopic (SEM) study of the skin surface showed numerous funnel‐shaped glandular openings. The antibacterial activity of the skin secretions was revealed in the test against Escherichia coli, Klebsiella pneumoniae, and Aeromonas hydrophila, all gram‐negative bacteria. SEM analyses confirm the membrane damage in bacterial cells on exposure to skin secretions of G. ramaswamii.     

Seasonal ultrastructural changes in apocrine gland cells in back skin of male brown bears (Ursus arctos)

Oily secretions from the back skin are involved in the marking behavior of male brown bears (Ursus arctos), and apocrine glands in back skin are activated during the breeding season. Here, we investigated seasonal changes in the intracellular organelles of apocrine gland cells in the back skin of male brown bears using transmission electron microscopy (TEM) and osmium‐maceration scanning electron microscopy (OM‐SEM). The morphological features of mitochondria and intracellular granules, and secretory mechanisms obviously differed between breeding and non‐breeding seasons. The TEM findings showed that contents of low‐density granules were released into the glandular lumen by frequent exocytosis, and sausage‐shaped mitochondria were located in the perinuclear region during the non‐breeding season. In contrast, high‐density granules appeared in the apical region and in projections during the breeding season, and swollen mitochondria and lysosome‐like organelles separating into high‐density granules were located in the perinuclear region. The OM‐SEM findings revealed swollen mitochondria with only a few partially developed cristae, and small mitochondria with cristae shaped like those in swollen mitochondria in the apical regions during the breeding season. These findings indicated that the small mitochondria corresponded to the high‐density granules identified by TEM. These findings suggested that mitochondria in apocrine gland cells swell, degenerate, fracture into small pieces, and are finally released by apocrine secretions during the breeding season. Small mitochondria released in this secretory manner might function as the source of chemical signals in the oily secretions of brown bears during the breeding season.     

A histochemical approach to glycan diversity in the urothelium of pig urinary bladder

Intracellular glycans in the urothelium of urinary bladder of 10 adult male Landrace pigs were characterized in situ by immunohistochemical detection of Muc1 mucin by anti MUC1 from rabbit, conventional histochemical techniques (Periodic‐Acid Schiff, Alcian Blue pH 2.5, High‐Iron Diamine), and binding with 13 lectins (PNA, DBA, RCA‐I, WGA, SBA, BSI‐B4, ConA, AAA, UEA‐I, LTA, LFA, MAA‐II, SNA) combined with chemical and enzymatic pre‐treatments (β‐elimination, desulfation and neuraminidase) to gather reference data for this model animal. Muc1 mucin was detected in the secreting granules of superficial cells and the underlying layer of intermediate cells. The secreting granules in both intermediate cells and superficial cells were rich in carbohydrates, with the oligosaccharidic chains mostly O‐linked to proteins. Glycoproteins were prevailing over glycosaminoglycans (GAGs). In both superficial and intermediate cells sulfated and/or sialylated glycans were present, sulfation decreasing in the deeper layers. Lectin‐binding detected presence of terminal sialic acid linked mostly in α2,6 to GalNAc, Gal terminal or subterminal to sulfates, GalNAc, GlcNAc, and Fuc, mostly linked in α1,6, α1,3 α1,4 and α1,2 to GlcNAc or Gal, but not to lactosamine chains. Except for fucosylation, the oligosaccharidic chains in the glycoproteins of the urothelium of pig urinary bladder were similar to those linked to human MUC1, which is fundamental in cell adhesion and immunological processes in the urothelium. The co‐distribution of Muc1 and saccharidic residues suggests that many of them are linked to the glycoprotein.     

Structural study of the salivary glands of Anocentor nitens (Acari: Ixodidae) during the feeding cycle

The salivary glands of Anocentor nitens (Neumann, 1897 ) occur in pairs and are located in the anterolateral region of the general cavity, with milky white color and approximately equal sizes. They consist of a secretory portion and an excretion duct. In some glandular acini, all the cells had a basophilic appearance they were stained by hematoxylin, whereas others presented cells with different staining affinities. In this work, we describe the variations observed in these glands during the feeding cycle of ticks [after feeding (0 h) and successively at 24, 48, 72, 96, 120, and 144 h]. The cells stained by hematoxylin were shown to be more reactive to Alcian blue, thus demonstrating the presence of acid glycosaminoglycans, whereas those stained using eosin presented weak or no reaction. A strong reaction was found by the use of the periodic acid‐Schiff (PAS) technique, thereby suggesting the presence of glycogen and/or glycoconjugates containing hexose, confirmed by using salivary amylase before PAS, with partial destaining of the slides. Continuing presence of residual staining in these cells suggests the presence of glycoconjugates containing hexose. Cells with nuclei of circular outline and few granules (of different sizes) were found in type II acini, 72 h after collection. Type I acini presented wide lumina and walls composed of larger numbers of cells of cubic to cylindrical shape. The pronounced degranulation shown in this study over the course of the feeding cycle was associated with the release of substances for oviposition. Microsc. Res. Tech., 2009. © 2009 Wiley‐Liss, Inc.     

Fine structure of the male accessory glands of Triatoma rubrofasciata (De Geer, 1773) (Hemiptera, Triatominae)

Male of Triatoma rubrofasciata has four elongated sac-like reproductive mesodermic accessory glands, lined by an inner single layer of secretory cells, with basal plasma membrane infolds and short apical microvilli, and externally enveloped by a thin visceral muscle layer. The secretory cells have a well-developed rough endoplasmic reticulum, Golgi complex, mitochondria, and secretory granules. In one day old adult the gland cells are poorly developed, presenting small, electron-transparent secretory granules scattered among the rough endoplasmatic reticulum, whereas in three days old adult these cells have the cisternae of the rough endoplasmatic reticulum varing size degree, filled with granular electrondense content. In five days old males the secretory granules increase in diameter, being released to the gland lumen. Therefore, there is an increase of the secretory activity according to male maturation.     

Morphology and lectin‐binding sites of pyloric caeca epithelium in normal and GnRH‐treated Atlantic bluefin tuna (Thunnus thynnus) Linnaeus 1758

Mucosal epithelium of pyloric caeca was studied in normal and in GnRH‐treated Atlantic bluefin tuna Thunnus thynnus L., using morphological analysis, conventional and lectin glycohistochemistry. The lining epithelium consisted of columnar (absorptive) cells, goblet cells and intraepithelial leucocytes. The epithelium from normal animals was significantly taller than GnRH‐treated samples. Conventional histochemistry displayed the same staining pattern in normal and hormone‐treated specimens which showed a mixture of neutral and sulphated acidic glycoconjugates in the luminal surface and goblet cells, and neutral glycans in apical granules of enterocytes. Lectin histochemistry revealed a different glycoconjugate pattern in normal and GnRH‐treated tunas. In normal specimens the luminal surface expressed sialoglycoconjugates which bound MAL II, SNA, KOH‐sialidase‐PNA, KOH‐sialidase‐SBA as well as asialoglycans stained with HPA, SBA, GSA I‐B₄, LTA. N‐linked glycans were highlighted by Con A and KOH‐sialidase‐WGA. In GnRH‐treated tunas the luminal surface did not react with SNA, SBA and LTA. The columnar cells of normal tunas bound KOH‐sialisase‐PNA in the apical region, KOH‐sialidase‐PNA, KOH‐sialidase‐DBA, HPA, SBA, KOH‐sialidase‐SBA and KOH‐sialidase‐WGA in apical granules, GSA I‐B₄ and LTA in the supranuclear region. GnRH‐treated specimens showed some columnar cells that stained with KOH‐sialidase‐WGA in the apical granules and with GSA I‐B₄ in the supranuclear region. The goblet cells of normal animals produced mucins positive to PNA, HPA, KOH‐sialidase‐DBA, SBA, GSA II. The latter three binding sites lacked in GnRH‐treated tunas. The results suggest that the mucosal epithelium of Thunnus thynnus L. pyloric caeca expresses a complex glycan pattern that is affected by GnRH‐treatment. Microsc. Res. Tech., 2011. © 2010 Wiley‐Liss, Inc.     

Ultrastructural characteristics of ovine bone marrow‐derived mesenchymal stromal cells cultured with a silicon stabilized tricalcium phosphate bioceramic

Bioceramics are being used in experimental bone engineering application in association with bone marrow derived mesenchymal stem cells (BM‐MSCs) as a new therapeutic tool, but their effects on the ultrastructure of BM‐MSCs are yet unknown. In this study we report the morphological features of ovine (o)BM‐MSCs cultured with Skelite, a resorbable bioceramic based on silicon stabilized tricalcium phosphate (SiTCP), able to promote the repair of induced bone defect in sheep model. oBM‐MSCs were isolated from the iliac crest, cultured until they reached near‐confluence and incubated with SiTCP. After 48 hr the monolayers were highly damaged and only few cells adhered to the plastic. Thus, SiTCP was removed, and after washing the cells were cultured until they became confluent. Then, they were trypsinizated and processed for transmission electron microscopy (TEM) and RT‐PCR analysis. RT‐PCR displayed that oBM‐MSCs express typical surface marker for MSCs. TEM revealed the presence of electron‐lucent cells and electron‐dense cells, both expressing the CD90 surface antigen. The prominent feature of electron‐lucent cells was the concentration of cytoplasmic organelles around the nucleus as well as large surface blebs containing glycogen or profiles of endoplasmic reticulum. The dark cells had a multilocular appearance by the presence of peripheral vacuoles. Some dark cells contained endocytic vesicles, lysosomes, and glycogen aggregates. oBM‐MSCs showed different types of specialized interconnections. The comparison with ultrastructural features of untreated oBM‐MSCs suggests the light and dark cells are two distinct cell types which were differently affected by SiTCP bioceramic. Skelite cultured ovine BM‐MSCs display electron‐dense and electron‐lucent cells which are differently affected by this bioceramic. This suggests that they could play a different role in bioceramic based therapy.     

Human subcommissural organ, with particular emphasis on its secretory activity during the fetal life

The subcommissural organ (SCO) is a conserved brain gland present throughout the vertebrate phylum. During ontogeny, it is the first secretory structure of the brain to differentiate. In the human, the SCO can be morphologically distinguished in 7- to 8-week-old embryos. The SCO of 3- to 5-month-old fetuses is an active, secretory structure of the brain. However, already in 9-month-old fetuses, the regressive development of the SCO-parenchyma is evident. In 1-year-old infants, the height of the secretory ependymal cells is distinctly reduced and they are grouped in the form of islets that alternate with cuboid non-secretory ependyma. The regression of the SCO continues during childhood, so that at the ninth year of life the specific secretory parenchyma is confined to a few islets of secretory ependymal cells. The human fetal SCO shares the distinct ultrastructural features characterizing the SCO of all other species, namely, a well-developed rough endoplasmic reticulum, with many of its cisternae being dilated and filled with a filamentous material, several Golgi complexes, and secretory granules of variable size, shape, and electron density. The human fetal SCO does not immunoreact with any of the numerous polyclonal and monoclonal antibodies raised against RF-glycoproteins of animal origin. This and the absence of RF in the human led to the conclusion that the human SCO does not secrete RF-glycoproteins. Taking into account the ultrastructural, lectin-histochemical, and immunocytochemical findings, it can be concluded that the human SCO, and most likely the SCO of the anthropoid apes, secrete glyco- protein(s) with a protein backbone of unknown nature, and with a carbohydrate chain similar or identical to that of RF-glycoproteins secreted by the SCO of all other species. These, as yet unidentified, glycoprotein(s) do not aggregate but become soluble in the CSF. Evidence is presented that these CSF-soluble proteins secreted by the human SCO correspond to (1) a 45-kDa compound similar or identical to transthyretin and, (2) a protein of about 500 kDa.     

Ultrastructure of differentiating oocytes and vitellogenesis in the giant freshwater prawn, Macrobrachium rosenbergii (de man)

The ultrastructure of oogenesis in Macrobrachium rosenbergii, with reference to vitellogenesis, has not been reported. We used light and electron microscopy, as well as vitellin (Vn) purification and antibody production, to study the temporal and spatial production of Vn in the ovary by immunofluorescence. Histologically, the ovary is subdivided into cone‐shaped ovarian pouches with a central core containing layers of oogonia. These divide to produce oocytes that migrate outwardly and differentiate into mature oocytes. During the course of differentiation, oocytes undergo modifications, including the rearrangement of nuclear chromatin, the accumulation of ribosomes, rough endoplasmic reticulum (RER), and lipid, and the formation of secretory and yolk granules, resulting in four stages. Ultrastructurally, early previtellogenic oocytes (Oc₁) are characterized by the accumulation of new ribosomal aggregates, translocated from the nucleus. Late previtellogenic oocytes (Oc₂) show nuclear heterochromatin with a “clock face” pattern, the presence of RER, and three types of secretory granules. Follicular cells occupy the intercellular spaces and surround the Oc₂. Early vitellogenic oocytes (Oc₃) are larger, with nuclei containing predominantly decondensed euchromatin, and cytoplasm with yolk and secretory granules, and few lipid droplets. Late vitellogenic oocytes (Oc₄) are characterized by completely euchromatic nuclei, an indistinct plasma membrane, yolk platelets and secretory granules, and abundant lipid. Vitellogenin (Vg) in ovaries of M. rosenbergii consist of two main bands at MW 90 and 102 kDa. Our data indicates that Vn is present, and probably synthesized in Oc₃ and Oc₄, but there may be some undetected exogenous Vg production. Microsc. Res. Tech. 2012. © 2012 Wiley Periodicals, Inc.     

The defensive secretion of Carabus lefebvrei Dejean 1826 pupa (Coleoptera,Carabidae): Gland ultrastructure and chemical identification

This study documents the defensive function of flavored humor secreted by the abdominal glands of Carabus lefebvrei pupae. The morphology and the ultrastructure of these glands were described and the volatile compounds of glands secretion were identified by gas chromatography/mass spectrometry. The ultrastructure analysis shows an acinose complex formed by about 50 clusters. Each cluster has 20 glandular units and the unit—composed of one secretory and one canal cell lying along a duct—belongs to the class 3 cell type of Quennedey (1998). In the cytoplasm, the secretory cell contains abundant rough endoplasmatic reticula, glycogen granules, numerous mitochondria, and many well-developed Golgi complexes producing electron-dense secretory granules. Mitochondria are large, elongated, and often adjoining electronlucent vesicles. The kind and the origin of secretory granules varying in size and density were discussed. The chemical analysis of the gland secretion revealed the presence of a mixture of low molecular weight terpenes, ketones, aldehydes, alcohols, esters, and carboxylic acids. Monoterpenes, especially linalool, were the major products. We supposed that ketones, aldehydes, alcohols, esters, and carboxylic acids have a deterrent function against the predators and monoterpenes provide a prophylaxis function against pathogens. Microsc. Res. Tech., 2009. © 2008 Wiley-Liss, Inc.     

General morphology and ultrastructure of the female reproductive apparatus of Trichomalopsis shirakii crawford (Hymenoptera,Pteromalidae)

The morphology and ultrastructure of the female reproductive system were examined for a larval–pupal parasitoid Trichomalopsis shirakii Crawford of Oulema oryzae Kuwayama using light and electron microscopes. The reproductive system includes two ovaries, two pairs of accessory glands, an unbranched venom gland, a large venom reservoir and a Dufour gland. Each ovariole contains follicles and oocytes at different stages of maturation. A fibrous layer covers the surface of mature egg. The accessory glands are made up of a layer of secretory cells surrounded by muscle fibers. In these secretory cells, numerous mitochondria, electron‐dense secretory granules and vesicles filled with dense granular particles are present. These granular particles appear as virus‐like particles (VLPs). The venom gland consists of a single layer of secretory cells which are organelle rich with abundant rough endoplasmic reticulum, mitochondria and vesicular organelles, a layer of duct cells and an inner intima. The reservoir consists of a muscular sheath, epidermal cells with few organelles and an intima layer. The Dufour gland has a relatively large lumen surrounded by a single layer of columnar epithelial cells which are characterized by clusters of smooth endoplasmic reticulum and lipid droplets. Aside from the venom, the fibrous layer coating the egg and the granular particles which may be VLPs have been discovered in our study. They may serve as one of the parasitoid‐associated factors in their host–parasitoid relationship and play a role in host immune suppression. Microsc. Res. Tech. 79:625–636, 2016. © 2016 Wiley Periodicals, Inc.     

The cytoplasmic matrix of the adrenal chromaffin cells of rats under normal and stressed conditions

In embedment-free electron microscopy with polyethylene glycol embedding and subsequent deembedding, the conventional cytoplasm of the chromaffin cells was revealed to consist of a three-dimensional lattice of microtrabeculae and gives the impression that the chromaffin granules are held in place by the lattice. After the restraint stress, a substantial number of chromaffin cells were almost free of granules, and the microtrabecular lattice was much more compact than that in cytoplasmic regions occupied with remaining granules or increased mitochondria. In immunocytochemistry, actin immunofluorescence was confined to the subplasmalemmal regions, while tubulin and tropomyosin immunofluorescence appeared throughout the entire cytoplasm of normal chromaffin cells. After the stress, the immunofluorescence for actin and tubulin increased in intensity, while that for tropomyosin decreased. Immunogold labelings for actin and tubulin were found mainly on the thinner subplasmalemmal microtrabeculae and the thicker perikaryal ones, respectively, while some were deposited in the form of small aggregates on portions of microtrabeculae. No specific association between the gold labelings for actin or tubulin and the chromaffin granules was found, even in the subplasmalemmal regions. A hypothetical interpretation was proposed in which a more compact lattice of the microtrabeculae in spatial association with a looser lattice represents a gelated state of the cytoplasm. The significance of the gel—sol transition of the cytoplasmic matrix in relation to the secretory mechanism was discussed.     

Effect of black tea on histological and immunohistochemical changes in pancreatic tissues of normal and streptozotocin‐induced diabetic mice (Mus musculus)

The aim of the present study is to evaluate the effect of hot water extract of black tea in regenerating β cells in streptozotocin‐induced diabetic mice. Light microscopic examination of pancreatic sections of streptozotocin‐induced diabetic mice showed the acinar cells to be small, shrunken, and with deteriorated β cells. The dose of streptozotocin not only altered the function of β cells but also damaged the acinar region. The changes in acinar cells were coarsening of endoplasmic reticulation suggesting alteration in their secretory function. The control pancreatic tissue showed well‐defined granulated islets and dark β cells when stained with chrome hematoxylin and phloxine. Interestingly, pancreatic sections of diabetic mice fed with black‐tea extract showed regeneration of β cells and acinar region appeared normal with increased numbers of β cells. To understand the probable mechanism of action of black‐tea extract, we analyzed inducible nitric oxide synthase (iNOS) expression by immunohistochemistry and the results showed an increased iNOS levels in streptozotocin‐induced diabetic pancreas, and such high iNOS levels were inhibited in black‐tea extract treated mice. According to histological results obtained, it can be concluded that the black‐tea extract helps in regeneration of damaged pancreas and protects pancreatic β cells by its antioxidant action against nitrosative stress in streptozotocin‐induced diabetes. Microsc. Res. Tech., 2009. © 2009 Wiley‐Liss, Inc.     

1, 2 di‐substituted idopyranose from Vitex negundo l. Protects against streptozotocin‐induced diabetes by inhibiting nuclear factor‐kappa B and inducible nitric oxide synthase expression

The aim of this study is to investigate the mechanism of an action of compound isolated from Vitex negundo in streptozotocin‐induced diabetic mice. Light microscopic examination of liver, kidney and pancreatic sections of streptozotocin‐induced diabetic mice showed changes like coarsening of acinar cells of endoplasmic reticulum, destruction of β‐cells, and alteration in their secretory function were observed in the pancreas. Changes like dilation of vein, unusual concentric arrangement of hepatocytes, and liver fibrosis were observed in the liver. Thickening of tubules and expansion of glomerulus were observed in kidneys. All these altered parameters were reversed close to normal condition upon treatment using idopyranose. The results show the antidiabetic potential of idopyranose. Interestingly, liver, kidney, and pancreatic sections of diabetic mice fed with the isolated 1, 2 di‐substituted idopyranose showed regeneration of hepatocytes, nephrocytes, as well as β‐cells and acinar region appeared normal with increased numbers of β‐cells. To understand the probable mechanism of action of 1, 2 di‐substituted idopyranose, we analyzed proinflammatory inducible nitric oxide synthase (iNOS) and nuclear factor‐kappa B (NF‐κB) expression by immunohistochemistry and the results showed an increased iNOS and NF‐κB levels in streptozotocin‐induced diabetic liver, kidney and pancreas. Such high iNOS and NF‐κB levels were inhibited in 1, 2 di‐substituted idopyranose treated mice. The results suggest that 1, 2 di‐substituted idopyranose helps in the protection of hepatocytes, nephrocytes and pancreatic β‐cells probably by its action against NF‐κB and iNOS mediated inflammation in streptozotocin‐induced diabetes. Microsc. Res. Tech., 2011. © 2010 Wiley‐Liss, Inc.     

Organ culture of the bovine subcommissural organ: evidence for synthesis and release of the secretory material

The subcommissural organ (SCO) is a brain circumventricular organ formed by ependymal and hypendymal secretory cells. It secretes glycoproteins into the cerebrospinal fluid of the third ventricle where they condense into a thread-like structure known as Reissner's fiber (RF). The present study was designed to investigate whether or not the bovine SCO continues to synthesize and release glycoproteins after a long-term culture. Cultured explants of SCO survive for several months. The content of the secretory granules present in the cultured ependymocytes displayed immunoreactive and lectin-binding properties similar to those of the core glycosylated glycoproteins found in the bovine SCO. The explants actively incorporated (35)S-cysteine. In the cultured ependymocytes, the pattern of distribution of the radioactive label and that of the immunoreactive secretory material was similar, thus indicating that this material has been synthesized during culture. At the ultrastructural level, the cultured tissue exhibited a high degree of differentiation comparable to that of the bovine SCO in situ. A striking finding was the observation of similar results when cerebrospinal fluid was used as a culture medium. The addition of antibodies against RF-glycoproteins into the culture medium allowed visualization, by means of different immunocytochemistry protocols, deposits of extracellular immunoreactive secretory material on the free surface of the cultured ependymocytes, indicating that release of secretory glycoproteins into the culture medium does occur. Primary culture of dispersed SCO ependymocytes, obtained either from fresh or organ cultured bovine SCO, showed that these cells release RF-glycoproteins that aggregate in the vicinity of each cell. The present investigation has shown that: (1) two types of secretory ependymocytes become evident in the cultured SCO; (2) under culture conditions, the SCO cells increase their secretory activity; (3) explants of bovine SCO synthesize RF-glycoproteins and release them to the culture medium; (4) after release these proteins aggregate but do not form a RF; (5) a pulse of anti-RF antibodies into the culture medium blocks the secretion of RF-glycoproteins for several days.     

Real‐time in vivo confocal laser scanning microscopy of melanin‐containing cells: A promising diagnostic intervention

The use of noninvasive imaging techniques to evaluate different types of skin lesions is increasing popular. In vivo confocal laser scanning microscopy (CLSM) is a new method for high resolution non‐invasive imaging of intact skin in situ and in vivo. Although many studies have investigated melanin‐containing cells in lesions by in vivo CLSM, few studies have systematically characterized melanin‐containing cells based on their morphology, size, arrangement, density, borders, and brightness. In this study, the characteristics of melanin‐containing cells were further investigated by in vivo CLSM. A total of 130 lesions, including common nevi, giant congenital pigmented nevi, vitiligo, melasma, melanoma, and chronic eczema, were imaged by in vivo CLSM. This research helps dermatologists understand the characteristics of melanin‐containing cells and facilitate the clinical application of melanin‐containing cells in the investigation of dermatological disease. In summary, melanin‐containing cells include keratinocytes, melanocytes, macrophages, and melanocytic skin tumor cells. Our study presents the CLSM characteristics of melanin‐containing cells to potentially facilitate in vivo diagnosis based on shape, size, arrangement, density, borders, and brightness. Microsc. Res. Tech. 78:1121–1127, 2015. © 2015 Wiley Periodicals, Inc.     

Freeze-fracture and immunomorphological analysis of spiral ganglion cells

Freeze-fracture analysis of adult spiral ganglion cells of CBA/CBA mice revealed two types of membrane specializations. Most cells (type I) had a smooth surface and were surrounded by Schwann cells. Type II spiral ganglion cells showed numerous membrane specializations with well-delineated indentations similar to those previously found on hair cells adjacent to afferent and efferent nerve endings. Immunomorphological analysis (using well-defined monoclonal antibodies directed against different subclasses of intermediate filament proteins) revealed a unique co-expression of neurofilaments, vimentin and cytokeratins in spiral ganglion cells of 8-to 22-week human fetuses.     

Moderated histogram equalization, an automatic means of enhancing the contrast in digital light micrographs reversibly

A means for improving the contrast in the images produced from digital light micrographs is described that requires no intervention by the experimenter: zero‐order, scaling, tonally independent, moderated histogram equalization. It is based upon histogram equalization, which often results in digital light micrographs that contain regions that appear to be saturated, negatively biased or very grainy. Here a non‐decreasing monotonic function is introduced into the process, which moderates the changes in contrast that are generated. This method is highly effective for all three of the main types of contrast found in digital light micrography: bright objects viewed against a dark background, e.g. fluorescence and dark‐ground or dark‐field image data sets; bright and dark objects sets against a grey background, e.g. image data sets collected with phase or Nomarski differential interference contrast optics; and darker objects set against a light background, e.g. views of absorbing specimens. Moreover, it is demonstrated that there is a single fixed moderating function, whose actions are independent of the number of elements of image data, which works well with all types of digital light micrographs, including multimodal or multidimensional image data sets. The use of this fixed function is very robust as the appearance of the final image is not altered discernibly when it is applied repeatedly to an image data set. Consequently, moderated histogram equalization can be applied to digital light micrographs as a push‐button solution, thereby eliminating biases that those undertaking the processing might have introduced during manual processing. Finally, moderated histogram equalization yields a mapping function and so, through the use of look‐up tables, indexes or palettes, the information present in the original data file can be preserved while an image with the improved contrast is displayed on the monitor screen.