Quantification of umu genotoxicity level of urban river water.

In recent years, the request of environmental safety management for carcinogenic substances, mutagenic substances and/or reproductive toxicity substances (CMR) has increased. This study focused on clarifying the genotoxicity level of environmental water and its release source by using the umu test provided in ISO13829. Although a genotoxicity index "induction ratio (IR)" is used in ISO13829, we normalised it to make it possible to compare various environmental water quantitatively to each other as a new index "genotoxic activity (GA=(IR-1)/Dose)". Sample water was collected and concentrated to 100 times or 1,000 times by a solid phase extraction method. As the test results, it was found that GA level in actual river water varied widely from less than the determination limit of 23 [1/L] to 1,100 [1/L] by quantitative comparison, and the value was also equivalent to more than 50 times the level of tap water. The GA level of household wastewater was not so high, but the levels of treated water from wastewater treatment plant (WTP) were from 220 [1/L] to 3,200 [1/L]. Raw sewage of some WTP shows high level genotoxicity. A part of genotoxicity substances, for example 50%, could be removed by conventional wastewater treatment, but it was not enough to reduce the water environmental load of genotoxicity.

Crystalloids in the excretory ducts of the accessory submandibular gland of the long-winged bat, Miniopterus magnator.

Cytoplasmic crystalloids are abundant in the excretory ducts of the accessory submandibular gland of the long-winged bat, Miniopterus magnator. The crystalloids, which always lack a membranous enclosure, may have an intricate silhouette. They consist of parallel linear densities with a 12.5 nm periodicity. These densities actually may be thin-walled tubules. In some crystalloids, intersecting subcrystalloids produce a complex pattern of decussate densities. In a few rare instances, continuities were detected between a crystalloid and a smooth-surfaced cisternal element. In other mammalian species, similar crystalloids connected to smooth endoplasmic reticulum play a role in steroid metabolism. We postulate that the ductular crystalloids in M. magnator might be involved in production of a factor that influences mating behavior.

Lipid droplet accumulation and lipoprotein lipase activity in the rat salivary gland during the perinatal period.

The submandibular and sublingual glands of foetal and newborn rats aged 21 days in utero to 7 days after birth were examined morphologically and biochemically. Lipid droplets tended to be localized in secretory cells, especially in their basal cytoplasm. The degree of droplet accumulation varied with the age of the rat. No droplets were observed before and immediately after birth. The number of accumulated droplets peaked 24-48 h after birth, then gradually decreased and reached normal levels by 5 days. In the salivary glands of fasted newborn rats, no lipid droplets were observed throughout the experiment. The amount of triacylglycerol reached its maximum level 1 day after birth; it then decreased gradually until 5 days and after that did not change. The amount of cholesterol did not change during postnatal development. Lipase activity attained its maximum level in the salivary glands immediately after birth and then decreased rapidly. It was higher in the glands of fasted than fed 1-day-old rats. Antiserum against lipoprotein lipase inhibited the salivary gland lipase activity in a dose-dependent manner, with 5 microliters of antiserum producing 60-70% inhibition. Non-immune serum had little effect. It was concluded that (1) accumulated lipid in the secretory cell cytoplasm of the salivary glands originates from ingested milk; (2) the principal component of accumulated lipid droplets is triacylglycerol; (3) 60-70% of the total lipase activity represents lipoprotein lipase; (4) an increase of lipoprotein lipase activity is recognizable before the accumulation of triacylglycerol.

Effect of parasympathectomy on the histochemical maturation of myoepithelial cells of the rat sublingual salivary gland.

This effect of parasympathectomy was assessed by fluorescent microscopy using nitrobenzoxadiazole-phallacidin, which is known for its specific binding to actin filaments. Resection of the chorda tympani within 48 h after birth inhibited the normal formation of actin in the myoepithelial cells and the maturation of myoepithelial cells. The effect of denervation decreased progressively if the operation was delayed. Denervation 30 days after birth had no effect on development and differentiation of myoepithelial cells. Moreover, the procedure produced no histochemical changes in the myoepithelial cells in mature rats, even two months later. These findings suggest that the parasympathetic innervation is closely involved in the maturation of myoepithelial cells. Further, its involvement is limited to the first 48 h after birth, during which it exerts its neurotrophic effect on the myoepithelial cells present in all the acinar buds.

Morphological changes in the myoepithelial cells of the rat sublingual salivary gland during differentiation as shown by the nitrobenzoxadiazole-phallacidin fluorescent method.

Changes in myoepithelial cells (MECs) during perinatal development were examined by using the fluorescent probe for actin, nitrobenzoxadiazole (NBD)-phallacidin. By the twentieth day of gestation, there was no distinct fluorescent pattern suggestive of MECs. In newborn and 1-day-old rats, cells with diffuse fluorescence occurred around the acini, representing incipient MECs. Between 3 and 4 days after birth, actin staining was concentrated in strands which were arranged parallel to the long axis of the cell processes. MECs had developed further by the tenth day after birth with an increased number and thickness of their processes. Fully developed MECs were found between the thirtieth and fortieth day. These were stellate and encompassed individual acini.

Giant secretory granules in the ducts of the parotid and submandibular glands of the slow loris.

The parotid and submandibular glands of a slow loris, a rare Southeast Asian primate, were obtained after the head had been perfused by fixative for a study of the brain. These tissues were processed by conventional means for electron microscopy. Glands also were obtained at autopsy from 2 other lorises, fixed by immersion in formalin, and subjected to a battery of tests for glycoconjugates. In the parotid gland, a short segment of the proximal striated duct lacks both basal striations and any sign of secretory activity. The major portion of the striated duct consists of tall cells that contain a spectrum of secretory granules, some larger than the nuclei (many granules are > 9 mum in diameter). These granules, which are delimited by a single membrane, are capable of chain exocytosis. Many of the giant granules have bundles of cytofilaments (4.5-6.5 nm) in apparent association with their surface. Occasional cells contain numerous small granules. Duct cells with or without granules lack basal striations. The granules contain neutral glycoconjugates but no acidic glycoconjugates. Some, but not all, interlobular excretory ducts also have secretory granules that run the gamut from tiny to giant. Exactly the same situation occurs in the submandibular gland. Unlike other primates, which may have duct cells that contain only a few tiny granules in their apices, the cells in both the striated and excretory ducts in the slow loris appear to be specialized for secretion rather than for transport. The biofunction of the giant granules is unknown.

Ultrastructure of the parotid gland in the common vampire bat, Desmodus rotundus, with special emphasis on oncocytes.

The parotid gland of the common vampire bat, Desmodus rotundus, is a pure seromucous gland. Typical acinar cells have a complement of secretory granules with a light matrix and one or several spherules and ancillary densities. These cells also contain mitochondria of conventional appearance. Mixed in with these acinar cells are cells that fulfil all of the ultrastructural criteria for identification as oncocytes. They contain enhanced numbers of mitochondria that frequently display peculiarities in the number and disposition of their cristae. The oncocyte mitochondria are closely packed and often are joined by periodic bridges. Most of the cells in the intercalated ducts are cytologically unremarkable; a few scattered duct cells have a single, grossly distended cisterna of rough endoplasmic reticulum that contains a homogeneous material of moderate density. The intercalated ducts are succeeded by ducts that lack the usual basal striations, but that consist of cells with numerous, small, dense granules. These secretory ducts probably are the homologues of striated ducts in parotid glands of other species. The structure of these ducts in the parotid gland in the vampire bat suggests that this gland does not play a homeostatic role in the regulation of electrolytes, a role that appears to be carried out in this bat in the submandibular glands, but that its major intralobular ducts contribute substantial quantities of organic material to the saliva.

Ultrastructure of major intraglandular ducts in the parotid gland of the African mole-rat.

The parotid gland of a female African mole-rat, Tachyoryctes splendens, was examined by light and electron microscopy. A pure seromucous gland of conventional histology, its striated and excretory ducts contain prominent cytoplasmic inclusions that are lightly stained with toluidine blue. At the ultrastructural level, the inclusions are seen to consist of a light to moderately dense structureless matrix in which are suspended scattered, randomly oriented filaments that either are 4-7 nm or approx 14 nm thick. A few multivesicular bodies or putative lipid droplets are sparsely distributed in the inclusions. Even though the inclusions lack an encompassing membrane, all other formed cytoplasmic structures are excluded. These inclusions are not present in the ducts of the submandibular gland of the mole-rat. The inclusions may confer special properties on the parotid gland of this fossorial animal that permit it to cope with the exigencies of a subterranean existence.

Histological convergent evolution of the accessory submandibular glands in four species of frog-eating bats.

The accessory submandibular glands in four species of bats were examined by electron microscopy. These four species represent two independently evolved lineages. The fringe-lipped bat, Trachops cirrhosis, is a Neotropical phyllostomid species, whereas the false vampire bats of southeast Asia, Megaderma lyra and M. spasma, and the heart-nosed bat, Cardioderma cor, of East Africa are megadermatid species. These glands show extreme deviation from typical salivary gland histology: their secretory endpieces are in the form of follicles and their ducts lack the cytological details that permit identification of diverse duct segments. Despite their unusual histology, the secretory endpieces in M. lyra, M. spasma, and C. cor consist of secretory cells that conform to typical secretory cell morphology. In contrast, secretion by follicular cells in T. cirrhosis involves unusual cytoplasmic bodies, and their mitochondria frequently have intracristal crystalloids. Ducts in all four species consist of simple cuboidal to columnar epithelium without basal striations. Follicles and ducts in all four bats are surrounded by numerous myoepithelial cells and are heavily innervated by hypolemmal nerve terminals. Despite their widely separated geographical ranges, all four bat species consume frogs and other vertebrates. Frogs and toads often possess toxic cutaneous glands that provide a chemical defense against predation. It is postulated that the unusual accessory glands in the four frog-eating species secrete toxin-neutralizing salivary factors. The follicular form of the endpieces permits storage of preformed saliva and their coterie of myoepithelial cells and hypolemmal nerve terminals facilitates the sudden and rapid expulsion of saliva into the oral cavity during the consumption of noxious amphibians.

The developmental role of type III and type IV cells in the rat submandibular gland.

In addition to seromucous cells and a few mucous cells (Type II cells), submandibular glands of 2-8 month old rats contain two additional cell types: type III and type IV. Type III cells contain serous-type secretory granules that sometimes have a complex substructure; type IV cells appear to be seromucous, but their granules clearly are different from those in conventional endpiece seromucous cells. Both type III and IV cells are involved in histogenesis of new endpieces in a process that differs markedly from that occurring in perinatal glands. In this process, intercalated ducts bud and give rise to immature endpieces that consist entirely of type III cells. These differentiate into type IV cells, which in turn differentiate into standard seromucous cells. Concurrently, the intercalated ducts become shorter as their most distal cells differentiate into granular duct cells. This type of developmental process begins approximately 2 months postnatally, when histogenesis of endpieces by means of terminal tubules has ended, and continues until 6 months, when its frequency sharply declines.

Tuft cells in the main excretory duct of the rat submandibular gland.

The fine structure of tuft cells in the main excretory duct of rat submandibular gland was investigated using the high pressure freezing and freeze substitution (HPF-FS) method and compared with that seen with both conventional chemical fixation (CF) method and en bloc treatment with ruthenium red. Some MEDs also were subjected to histochemistry for lectins. The apical vesicles and tubules of tuft cells observed by TEM after the HPF-FS method were different in shape from those treated by CF. With the first method, these vesicles and tubules, which may represent sections of a tubular system, appeared more slender and filled with a material of moderate density. A prominent glycocalyx covering the microvillar plasma membrane was observed in tuft cells processed both with the HPF-FS method and with ruthenium red. The surface of microvilli and the tubulo-vesicular structures of these cells exhibited the same soybean agglutinin (SBA) reactivity, suggesting a relationship between them.

Lipid droplet accumulation in the exocrine glands of the newborn rat.

Exocrine glands including the submandibular gland, sublingual gland, exocrine pancreas and exorbital lacrimal gland of newborn rats aged 0 to 14 days were examined morphologically, and the following results on the accumulation of lipid droplets were obtained. Lipid droplets tended to localize in secretory cells, especially in their basal cytoplasm. The degree of lipid droplet accumulation varied with the type of exocrine gland. There were large accumulations in the sublingual gland, submandibular gland, and exocrine pancreas, but accumulations were small in the exorbital lacrimal gland. No difference in lipid droplet accumulation was recognized between the 2 types of secretory cells in the sublingual gland. The accumulation of lipid droplets peaked 24-48 hours after birth in the sublingual gland, submandibular gland and exocrine pancreas, but this peak was not clearly observed in the exorbital lacrimal gland. In the group of newborn rats separated from their mothers and therefore not suckled, no lipid droplets were observed in any gland, suggesting a close relationship between lipid droplet accumulation and suckling.

A scanning electron microscope study of myoepithelial cells in the intercalated ducts of rat parotid and exorbital lacrimal glands.

Myoepithelial cells in the intercalated ducts of rat parotid and exorbital lacrimal glands were examined by scanning electron microscopy. The basal surface of the intercalated ducts revealed myoepithelial cells running parallel with its long axis. These myoepithelial cells were linked with one another, forming a well-developed network, and numerous wrinkles running transversely were observed on the surface of the myoepithelial cells. Also, some myoepithelial cells in the terminal portion linked with those in the intercalated duct. Based on these findings, it is suggested that myoepithelial cells in the intercalated duct may function as a protective wall against constriction of the narrow lumen of the intercalated duct when it is subjected to pressure by the surrounding tissues.

Morphological studies of rat lingual filiform papillae.

In an attempt to elucidate the functions of three types of filiform papillae in the rat's tongue, corrosive resin casts of the microvessels in the filiform papillae were observed under the scanning electron microscope. The filiform papillae were also examined by light and transmission electron microscopy. The three dimensional architecture of the microvessel loops in the small conical filiform papillae was relatively simple with limited divergence and anastomosis in the papillae, whereas that in the large conical filiform papillae formed a complex network which resulted from repeated divergence and anastomosis. The microvessels in the thready filiform papillae branched several times in the primary papillae and then formed a hairpin-like loop in each of the secondary papillae. Under the light and transmission electron microscope, the small and large conical filiform papillae revealed remarkably similar tissue architectures, with the exception of their sizes. However, these two types of filiform papillae were arranged in quite opposite directions. In the large conical filiform papillae, the epithelium on the anterior side of the papillae lacked a granular layer, whereas the epithelium on the posterior side contained a well-developed granular layer. Based on these findings, we presume that the functions of the three type of filiform papillae are as follows. That of the small conical filiform papillae is to take food efficiently into the oral cavity. That of the large conical filiform papillae is to grind further the food which has been crushed with the teeth in coordination with the palate. The thready filiform papillae might function as a heat-releasing organ and be involved in the control of body temperature.

Primary small cell carcinoma of lacrimal sac: case report and literature review.

OBJECTIVE: We present the first reported case of primary small cell carcinoma of the lacrimal sac. CASE REPORT: A 67-year-old Japanese woman was referred to our department with a two-month history of left medial canthal swelling, epiphora and occasional nasal bleeding. Nasal endoscopy revealed a readily bleeding tumour in the left inferior meatus. Computed tomography and magnetic resonance imaging scans demonstrated that the tumour was mainly located in the left lacrimal sac. Histopathological studies of a biopsy specimen revealed small cell carcinoma. The patient was treated with four cycles of chemotherapy consisting of cisplatin and etoposide, in combination with radiotherapy. There was no evidence of recurrence or metastasis for five years. CONCLUSION: Small cell carcinoma originating in the head and neck region has been reported to be highly aggressive and to have a poor prognosis. We report a case of primary small cell carcinoma of the lacrimal sac successfully treated with chemo-radiotherapy.

Ultrastructure of the angularis oris salivary gland in the house sparrow.

The angularis oris gland, an avian salivary gland that lies beneath the zygomatic arch, was studied in the house sparrow by means of light and electron microscopy. The gland consists of lobules composed of epithelial tubules and folds on a delicate connective tissue framework. The lobules are drained by large channels to form an intraglandular duct, which becomes the main extraglandular duct. The tubules, folds, and all ducts are covered by pseudostratified epithelium that shows progressive changes from the blind ends of tubules to the duct system. At the closed end of the tubules, the tall cells contain an aggregation of closely packed mucous droplets; their mitochondria are long and slender. As the epithelium nears the duct system, the mucus content of the tall cells is reduced and the mitochondria, which are increased in number, are ovoid. The lateral borders of the cells are complexly interlocked. In the ducts, mitochondria-rich cells with extensive lateral interfoliation comprise the major cell type; some of these cells contain a few mucous droplets at their apices. The basal cells of the pseudostratified epithelium have the same basic structure regardless of their location. These pyramidal cells have abundant cytofilaments and are joined to the basal lamina by many hemidesmosomes. Despite the absence of clear-cut morphological zonation, the angularis oris may function in a manner that is analogous to mammalian salivary glands: secretory cells produce the organic component of the saliva, mucus, while the mitochondria-rich cells with their extensive lateral membranes probably resorb electrolytes to render the final saliva hypotonic.

Ultrastructure of the submandibular gland in 2 species of macaques.

The ultrastructure of the submandibular glands was studied in 2 species of macaques (Macaca mulatta and Macaca irus). The glands, which were identical in both species, were predominantly serous, but contained scattered mucous acini. The serous cells contained 1 of 2 morphologically distinct secretory granules of complex substructure, whereas mucous droplets were relatively simple in structure. Other parts of the macaque glands were similar to their counterparts in other primates. The close resemblance of the serous granules to each other in the 2 species studied and to 3 other macaque species previously described by others suggests that these monkeys are taxonomically closely related.