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B Tandler

Publications and source records attributed to B Tandler.

At least 91 records · Page 5Linked to original sources
PubMed1986

Ultrastructure of the retrolingual salivary gland of the European hedgehog.

Retrolingual glands of the European hedgehog are pure mucous salivary glands consisting of mucous acini, intercalated ducts, and excretory ducts, but lacking striated ducts. The acinar cells, which lack basal folds, are filled with mucous droplets that have a fibrillogranular matrix. Many of the intercalated duct cells contain a single cytoplasmic inclusion that often is nearly as large as the nucleus. These inclusions are expanded cisternae of rough endoplasmic reticulum with moderately dense contents in which are embedded lamellar densities that give the inclusions the appearance of a badly reproduced fingerprint. Despite these obvious signs of secretory activity, the intercalated duct cells contain only a few secretory granules. Proceeding distally along the excretory ducts, the epithelium gradually changes from the simple cuboidal to simple columnar to pseudostratified. In those segments of the excretory duct composed of simple columnar epithelium, most cells contain small secretory granules. In the pseudostratified portion of the duct, the tall cells frequently contain an aggregate of mitochondria held together by regularly spaced filaments.

Animals↗
PubMed1986

Unusual myoepithelium in the retrolingual salivary gland of the European hedgehog.

The myoepithelial cells of the hedgehog retrolingual salivary gland have an unusual three-dimensional configuration. Many of the myoepithelial processes are not closely apposed to the overlying epithelial cell, but pursue a seemingly independent course in the connective tissue. The multiplicity of myoepithelial processes gives the intercalated ducts the appearance of being ensheathed by several layers of smooth muscle, each delimited by basal lamina, but these layers can be traced back to their myoepithelial origin. Contiguous myoepithelial processes are joined to one another and to secretory or duct cells by desmosomes. Myoepithelial processes completely enclosed by a sleeve of basal lamina are attached to the lamina densa by numerous hemidesmosomes, ensuring that the processes and their covering move in concert during contraction and relaxation.

Animals↗
PubMed1986

Ultrastructure of von Ebner's salivary glands in the rabbit.

The von Ebner's salivary glands associated with the vallate and foliate papillae of the rabbit tongue were studied by light and electron microscopy. The glands are tubulo-alveolar in structure and have an abbreviated duct system. The seromucous cells of the secretory end-pieces contain numerous granules with a complex substructure; when the granule matrix is partially extracted as the result of less-than-optimal fixation, these granules are seen to contain bundles of 17-18 nm filaments. The ductular epithelium undergoes progressive change from simple columnar to stratified cuboidal or columnar. Both of these duct segments contain secretory granules that differ from those in the tubulo-alveolar cells and from each other. Thus the constituent cells of leporine von Ebner's glands produce a variety of organic secretory products.

Animals↗
PubMed1986

Ultrastructure of dog parotid gland.

The ultrastructure of the parotid gland was examined in two purebred strains of dogs, as well as in mongrels. The seromucous acinar cells contain numerous secretory granules of unusual substructure that varies somewhat from one granule to another. The most common configuration consists of a large, dense spherule surrounded by a thin electron-lucent halo. The matrix is composed of a series of dense beads, each delimited by a light ring. Between these beads is a material of intermediate density that sometimes forms a corona around the spherule. The organization of the granule is somewhat altered when osmication is omitted from the fixation procedure. Striated ducts have basal regions that are of conventional appearance, but the cell apex is characterized by a collection of ellipsoidal structures oriented perpendicular to the luminal plasma membrane. At least in some cases these are joined to the plasma membrane by fine threads. Despite the obvious phenotypic differences in the canine breeds used in this study, their parotid glands were identical, indicating that the genetic mechanisms that control gland structure, especially secretory granule substructure, have not been affected by selective breeding.

Animals↗
PubMed1985

Biochemical differences between subsarcolemmal and interfibrillar mitochondria from rat cardiac muscle: effects of procedural manipulations.

Differences in oxidative metabolism between subsarcolemmal and interfibrillar heart mitochondria were investigated. Interfibrillar mitochondria oxidized substrates donating reducing equivalents at Complex I (NADH-CoQ reductase), Complex II (succinate-CoQ reductase), and Complex III (CoQH2-cytochrome c reductase) more rapidly than did subsarcolemmal mitochondria. There was no difference in oxidation of substrates entering the electron transport chain at Complex IV (cytochrome c oxidase). Differences expressed in normal-ionic-strength medium at Complexes II and III but not I were eliminated in low-ionic-strength medium. The concentrations of cytochromes and activities of NADH and cytochrome c oxidase were virtually the same in the two populations. In permeabilized mitochondria, activities of succinate-duroquinone and TMPD plus ascorbate oxidase were significantly lower in the subsarcolemmal mitochondria. Differences in membrane permeability between the populations were suggested by the greater permeability of subsarcolemmal mitochondria to exogenous NADH. The influence of isolation buffers and preparative procedures on the two classes of mitochondria were also examined. Characteristic biochemical and morphological properties of the two populations were unchanged by exposing each to the preparative procedure used to isolate the alternate population; the oxidative performance of the two populations cannot be equalized by experimental manipulation.

Animals↗
PubMed1984

Proteinases release mucin from airways goblet cells.

The mucin-release effect of proteinases on airways epithelium was assessed in vitro. Using explants of rabbit tracheal mucosa-submucosa we determined that elastase and alkaline proteinase from Pseudomonas aeruginosa, pancreatic trypsin and elastase and the microbial proteinases subtilisin, thermolysin and pronase, all stimulate mucin release from goblet cells. On the other hand Streptomyces caespitosus proteinase pancreatic chymotrypsin and collagenase fail to trigger mucin release. Bovine trachea and human nasal polyp epithelium also release mucins in response to proteinases. Mucin release activity is dependent on proteolytic activity of enzymes which have a fairly broad, but generally similar, substrate specificity. The cellular mechanism of action is not known. We propose that mucin secretion in response to proteinases represents a useful defence mechanism but also forms the basis for hypersecretory states and airways obstruction in chronic endobronchial inflammatory states.

Animals↗
PubMed1984

Ultrastructure of the parotid gland in the little brown bat.

The ultrastructure of the parotid gland was examined in the little brown bat. The seromucous acinar cells contained abundant granules of variable morphology. These granules were characterized by a submembranous dense layer consisting of fine parallel slats. In some bats, the matrix of the granules was structureless, whereas in others it consisted of closely packed but randomly arranged bundles of tubules. The intercalated ducts had a highly developed rough endoplasmic reticulum, often containing large numbers of intracisternal granules. In contrast, only a few secretory granules were present in the supranuclear cytoplasm. The striated ducts, which exhibited the characteristic basal striations consisting of vertically oriented mitochondria and highly folded plasmalemmas, contained numerous small dense granules in a subluminal band. These granules had a paracrystalline substructure with a periodicity of 8 nm. Excretory ducts strongly resembled striated ducts. They showed the same kind of basal striations and about half their constituent cells contained small paracrystalline granules.

Animals↗
PubMed1984

Pulmonary cellular response to chronic irritation and chronic Pseudomonas aeruginosa pneumonia in cats.

A model of chronic pulmonary infection was used for studying cellular events in a sequential manner. In this model, agarose beads containing Pseudomonas aeruginosa were instilled endotracheally into cats. Nine cats were inoculated with agarose beads containing P. aeruginosa, and four others were inoculated with sterile beads. With a fiberoptic bronchoscope, bronchial washings were obtained biweekly for up to 30 weeks. The quantitative pulmonary inflammatory cell response and alveolar macrophage morphology of the animals exposed to P. aeruginosa were compared with those for the animals exposed to a chronic irritant (agarose beads). Bronchial washings of all animals before inoculation showed that 70 to 90% of the cells were macrophages. After inoculation with P. aeruginosa, a persistent inflammatory response was observed (60 to 70% granulocytes). In the sterile-bead-inoculated group, the response was less prominent (30 to 40% granulocytes). As early as 2 weeks after inoculation, alveolar macrophages from infected animals were larger and had cytoplasmic features that differed from those of controls. Electron microscope examination showed prominent surface alterations in alveolar macrophages from the infected cats. These alterations persisted from 2 to 12 weeks after infection. In animals inoculated with sterile beads, alveolar macrophages exhibited less extensive surface changes that had resolved by week 8. Histologically, chronic bronchiolitis and pneumonia were more severe in the infected animals than in controls. This model of chronic inflammation and macrophage stimulation, which is similar to the chronic pneumonia of cystic fibrosis, may be a useful approach to answer questions on the role of macrophage activation in chronic lung disease.

Animals↗
PubMed1984

Physiological responsiveness of isolated rabbit tracheal epithelial cells.

Surface tracheal epithelial cells (tracheocytes) from rabbit were isolated by treating intact tissue with chelators and proteolytic enzymes. The cells were viable as assessed by the following criteria: fluorescent viability staining, sequestration of lactate dehydrogenase, and maintenance of constant ATP levels. Radiolabeled Na+ was transported into cells with a rate constant of 0.06/min and an initial velocity of 1.6 nmol X 10(6) cells-1 X min-1 X beta-adrenergic agonists increased adenosine 3',5'-cyclic monophosphate (cAMP) levels in a time- and dose-dependent manner. The beta-adrenergic effects were potentiated by the phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine and blocked by propranolol. The tracheocytes retained the capacity to respond to beta-adrenergic agonists for at least 90 min after isolation. Two major cAMP binding proteins of apparent molecular weights of 50,000 and 54,000 were identified in tracheocytes with the photoaffinity label 8-N3-[32P]cAMP. Agents that increased cAMP levels in intact cells and unlabelled cAMP added to homogenates of cells that were not exposed to drugs decreased photoaffinity labeling. The two proteins correspond in electrophoretic mobility to the regulatory subunits of cAMP-dependent protein kinases I and II, respectively. The results demonstrate that the beta-adrenergic receptors and cAMP binding proteins identified in rabbit tracheal mucosa submucosa are present on tracheocytes, suggesting a role for these receptors in the regulation of tracheocyte physiological events.

Adrenergic beta-Agonists↗
PubMed1984

Proteinases of Pseudomonas aeruginosa evoke mucin release by tracheal epithelium.

We have determined the potential of exoproducts from pathogenic bacteria to stimulate the release of high molecular weight mucins from goblet cells of airway epithelium in a rabbit tracheal explant system. Culture supernatants from proteolytic strains of Pseudomonas aeruginosa and Serratia marcescens, but not supernatants from a number of non-proteolytic strains, released mucins from goblet cells. Highly purified elastase and alkaline proteinase from P. aeruginosa stimulated goblet cell mucin release in a dose-dependent fashion. Lipopolysaccharide, exotoxin A, and alginate of P. aeruginosa did not possess mucin release properties. Proteolytic activity was required for mucin release by P. aeruginosa elastase, but such release in goblet cells was not mediated by cyclic AMP. Morphologic studies suggested rapid release of mucins from goblet cells was response to elastase by a process resembling apocrine secretion. Several nonbacterial proteinases mimicked the effect of Pseudomonas proteases. These studies provide support for the hypothesis that bacterial and other play a role in the pathogenesis of mucus hypersecretion in acute and chronic lung infections.

Adenylyl Cyclases↗
PubMed1983

Surface architecture of the mucosal epithelium of the cat trachea: I. Cartilaginous portion.

The mucosal covering of the cartilaginous portion of the cat trachea was studied by correlated light, transmission-electron, and scanning-electron microscopy. While in some areas the ciliated pseudostratified epithelial lining is fairly smooth in contour, in other areas it contains longitudinally oriented, cilia-lined clefts. Ducts from submucosal glands sometimes open into the base of these clefts, or into funnel-shaped stomata that are lined by either ciliated or microvillus-rich cells. Specialized epithelial cells are occasionally associated with the clefts or with other regions of surface epithelium. In single sections, these cells appear to contain a cilium-lined vacuole, but serial sectioning has demonstrated that these apparent vacuoles actually are long intracellular invaginations in enormously elongated cells that extend longitudinally in the plane of the epithelium. The function of these cells is undetermined. Basal cells are attached to the lamina densa by means of hemidesmosomes that consistently lack peripheral densities; in contrast, the tall columnar cells have no hemidesmosomes.

Animals↗
PubMed1983

Surface architecture of the mucosal epithelium of the cat trachea: II. Structure and dynamics of the membranous portion.

Bronchoscopic examination of anesthetized cats revealed that the trachea is capable of considerable change in caliber via lateral expansion of the membranous trachea. The morphological basis for this expansile capacity was determined by correlated light microscopy and scanning and transmission electron microscopy. The organization of the membranous trachea differs from that of the cartilaginous trachea. The mucosa is arranged in a series of longitudinal folds that open like an accordion when stretched laterally. These fold are not random, but appear to depend on rows of nonciliated, microvillus-rich cells that form flexure lines in the surface epithelium. The mitochondria in such cell have a condensed configuration, indicating a high level of oxidative metabolism and suggesting that they may participate in transport processes that modify the luminal contents. Goblet cells, which are relatively sparse in the membranous trachea, have mitochondria in which the prominence of matrix granules and degree of mucus storage are inversely related. Mitochondrial morphology allows goblet cells that have discharged their mucin content to be readily distinguished from the microvillus-rich cells, even when their luminal surfaces lie outside the thickness of a section.

Animals↗
PubMed1983

Purification of brush border membrane by thiocyanate treatment.

Rat small intestinal brush border membranes are purified from brush borders by homogenization in relatively high concentrations of thiocyanate salts (0.56 M LiSCN, 0.41 M NaSCN, or 0.52 M KSCN), removal of this salt, and differential centrifugation to separate cytoskeletal material from membranes. The marker enzyme, sucrase, is enriched 98-fold in the final membranes over the starting homogenate of intestinal scrapings at a yield of about 20%. The isolated membranes are capable of secondary active sodium-dependent glucose transport as demonstrated by sodium gradient-supported overshooting glucose uptake.

Animals↗
PubMed1983

Giant mitochondria in a pleomorphic adenoma of the submandibular gland.

A benign pleomorphic adenoma of the submandibular gland was examined by electron microscopy. In some areas, the epithelial cells comprising the tumor formed ductlike structures surrounding a lumen filled with membrane vesicles. The cells actually abutting the lumens had giant mitochondria measuring up to 8 micrometers in diameter; such enlarged organelles were absent from immediately subjacent cells. The giant mitochondria exhibited a variety of cristal arrangements, the most common being a quasireticulate one. They often contained expanded cristae that enclosed a number of helical filaments. Bundles of 14-nm tubules with faintly discernible axial periodicity were frequently present in the matrix compartment, as were amorphous dense inclusions. The basis for the occurrence of giant mitochondria only in duct cells may reside in microenvironmental factors rather than in altered nuclear or mitochondrial genomes.

Adenoma, Pleomorphic↗
PubMed1983

Ultrastructure of mink submandibular gland.

The submandibular gland of the North American mink, a strict carnivore, was studied by light and electron microscopy. The gland is mixed in nature, consisting of mucous tubules capped by mucous demilunes. Mucous droplets in the tubule cells are structureless, but those in the demilune cells contain a dense spherule. Intercalated ducts are extremely short. Striated duct cells contain numerous crystalloids, often rhomboidal, in their apical cytoplasm. These crystalloids are equally abundant in males and females. The presence of these structures lends credence to the supposition that in addition to their role in electrolyte transport, striated ducts may be actively engaged in secretion of organic products.

Animals↗
PubMed1982

Histology and histochemistry of the parotid and the principal and accessory submandibular glands of the little brown bat.

The parotid and the principal and accessory submandibular glands of the little brown bat. Myotis lucifugus (Vespertilionidae), were examined using light microscopy and staining methods for mucosubstances. The parotid gland is a compound tubuloacinar seromucous gland. Parotid gland secretory cells contain both neutral and nonsulfated acidic mucosubstances. The principal and accessory submandibular glands are compound tubuloacinar mucus-secreting glands. They contain somewhat atypical mucus-secreting demilunar cells that often appear to be interspersed between mucous tubule cells. The mucous tubule cells in both the principal and accessory submandibular glands contain sulfonmucins. Demilunar cells of the principal submandibular gland contain moderate amounts of nonsulfated acidic mucosubstances, but the corresponding cells of the accessory submandibular gland contain considerable neutral mucosubstance with very little acid mucosubstance. Intercalated ducts composed of cuboidal or low columnar epithelial cells are present in all three glands. Striated ducts in all glands are composed of columnar cells whose apices bulge into the ductal lumina. Excretory ducts are composed of simple columnar epithelium, with occasional basal cells that suggest a possible pseudostratified nature. The cells of the excretory ducts also have bulging apices. All duct types contain apical cytoplasmic secretory material that is a periodic acid-Schiff positive, neutral mucosubstance. Ductal apical secretory material is more evident in intercalated and striated ducts than in excretory ducts.

Animals↗
PubMed1982

Glucocorticoid-induced alterations in the rabbit heart.

Daily intramuscular injection of the synthetic glucocorticoid, betamethasone, into rabbits for 2 weeks resulted in both gross and microscopic alteration of cardiac muscle. A 30 per cent increase in heart weight was based on increased muscle fiber size occasioned by the deposition of fibrillo-granular material (not glycogen in nature) in the cytosol. At the same time, some myocytes underwent profound myolysis, predominantly at the nuclear poles, occasionally pervading the entire cell. Conventional lysosomes were not increased in number or size, but certain cells possessed prominent cytoplasmic vacuoles that sometimes contained mitochondria. The biochemical basis for these cardiac changes is undetermined, but the obvious ultrastructural damage produced by betamethasone, particularly dissolution of myofibrils, may prove to have clinical significance.

Animals↗