Electron-microscopic study of the development of an equine adenovirus in cultured fetal equine kidney cells

Sequential changes induced by an equine adenovirus in cultured fetal equine kidney cells were studied by electron microscopy. The first morphological change was the appearance of type I inclusions. These inclusions developed to type II inclusions which appeared as ring forms. Type III inclusions were formed within the central part of type II inclusions and finally filled up most of the nuclear space. As the infection proceeded, type IV inclusions which appeared as dense dark-staining spheres were formed at the center of the type III inclusions and also inside the cytoplasm. These dark-staining spheres developed and their center was filed with light-staining material and virus particles which eventually resulted in the formation of type V inclusions. Autoradiography study showed that types I, II, and III were composed of nucleoprotein and type IV was composed of protein.     

Electron-microscopic observations of normal coelomocytes from the earthworm,Lumbricus terrestris

Summary Coelomocytes of the earthworm, Lumbricus terrestris, were studied by transmission electron microscopy. Four morphological cell types are distinguishable: lymphocytic coelomocytes, granulocytic coelomocytes, eleocytes (chloragogen cells), and inclusion-containing coelomocytes. Within these major categories, several distinct cell types differ and may represent developmental stages. The two types of lymphocytic coelomocytes are small with central nuclei and scanty cytoplasms. Two types of granulocytic coelomocytes differ greatly in shape and content; both have small dark-staining granules that resemble lysosomes. Electrocytes, derived from chloragogen tissue, contain a variety of granules, inclusions and vacuoles. Inclusion-containing coelomocytes appear as two types which may be immature and mature forms. Although these cells resemble those that have been referred to as erythroid cells in other invertebrates, the large inclusion bodies are apparently unrelated to hemoglobin; they can undergo morphologic transformation and be extruded by exocytosis. This information on lymphocytic, granulocytic and inclusion-containing coelomocytes is crucial to understanding more about cellular immunity in the earthworm.D.S.L. is supported by USPHS Training Grant AI-00453-05. E.A.S., D.H.M. and E.L.C. are supported by USPHS Grant HD-09333-03     

Chemical blockade of olfactory perception by N-methylformimino-methylester in albino mice. II. Light microscopical investigations

Evidence is given that N-methyl-formimino-methylester (MFM),a highly volatile substance, causes olfactory receptor celldegeneration in mice. The time course of this degeneration andmorphological changes in the compartment of receptor cell progenitorcells are described. Due to the morphological appearance ofthe progenitor cells and their dynamic transformation afterexposure to MFM, two different types of progenitor cells canbe distinguished: (a) light-staining globose basal or blastemacells, which are thought to be real progenitor cells and toremain in the mitotic cycle for generating new sensory cells;and (b) dark-staining basal cells with condensed chromatin,which are quiescent. The results agree with electrophysiologicaldata indicating temporary inhibition of olfactory perceptionafter MFM.     

Morphology and innervation of the buccal glands of the Southern Hemisphere lamprey, Geotria australis.

The buccal glands of adults of the Southern Hemisphere lamprey Geotria australis consist of a pair of small, bean-shaped, hollow sacs, embedded within the basilaris muscle in the region below the eyes and to either side of the piston cartilage. Each gland, which is lined by a simple columnar epithelium and surrounded by an incomplete layer of skeletal muscle, discharges its contents into the oral cavity via a long, narrow duct. In downstream migrating young adults, the epithelial cells are low columnar, intermediate in electron density, and contain dark-staining inclusions and numerous lipid-like droplets. After saltwater acclimation, the epithelial cells become taller and the numbers of dark-staining inclusions increase whereas those of lipid-like droplets decline. By the end of the marine phase, the epithelium is more folded and now also contains dark and light cells. The ultrastructure of the epithelium shows the characteristics of both apocrine and merocrine secretion. Although intra-epithelial nerve endings were not observed, axons and occasional neurons are present in the lamina propria. Since the skeletal muscle capsule is also well innervated and contains neurons, a local feed-back mechanism may regulate the release of buccal gland fluid by monitoring the luminal pressure. Contractions of the skeletal muscle capsule and movements of the basilaris muscle during feeding would presumably assist the movement of secretion along the duct. The secretion possesses anticoagulating and haemolytic properties.     

A comparative study of the embryological development of the median cord in hemiptera

Median cord development is uniform in six families of Hemiptera and five non-hemipterans. The median cord arises independently from the lateral cords and is histologically distinguishable from the latter throughout development. Intrasegmentally, median cord nuclei possess prominent nucleoli and many small chromatin granules surrounded by clear nuclear sap. This region forms what appear to be glial elements at the midline of the neuropile. Intersegmentally, a spherical clump of eight to twelve large nuclei develops surrounded by dark-staining granular cytoplasm. Each intersegmental clump migrates anteriorly into the preceding ganglionic region but degenerates soon after katatrepsis.     

A SEASONAL STUDY OF THE VEGETATIVE SHOOT APEX AND THE PATTERN OF PITH DEVELOPMENT IN HIBISCUS SYRIACUS

Tolbert , Robert J. (West Virginia U., Morgantown.) A seasonal study of the vegetative shoot apex and the pattern of pith development in Hibiscus syriacus. Amer. Jour. Bot. 48(3): 249–255. Illus. 1961.—The shoot apex of Hibiscus syriacus L. is described as having a cytohistological zonation superimposed on a tunica-corpus configuration. The apex is flat-topped or may have a saddle-back or concave appearance as seen in median longitudinal section. The metrameristem, consisting of the tunica and corpus initials, is comprised of large, light-staining, vacuolate cells that have thick cell walls and exhibit much dark-staining intercellular substance. Surrounding the metrameristem is the flanking meristem, which is responsible for the outer layers of the shoot, and from which the leaf primordia arise. The pith rib meristem lies below the metrameristem and consists of files of cells that are responsible for the pith. There are no major seasonal changes in the structure of the apex during the yearly cycle. The pith displays a long-shoot type of development with the cells remaining in distinct files during the first flush of growth in the spring. As growth slows and internode elongation is gradually reduced, the pith displays the characteristic short-shoot type of development, consisting of a spongy tissue of rounded cells with many intercellular spaces and no distinct files of cells. A crown is differentiated across the top of the pith at the end of the growth period. This consists of a band of cells with thick, dark-staining cell walls, which separates by the apex from the last year's growth. In contrast to many gymnosperms, this crown is dispersed by renewed cell activity the following spring.     

Intracellular Production of Brucella L Forms I. Recovery of L Forms from Tissue Culture Cells Infected with Brucella abortus

Hatten, Betty A. (The University of Texas Southwestern Medical School, Dallas), and S. Edward Sulkin. Intracellular production of Brucella L forms. I. Recovery of L forms from tissue culture cells infected with Brucella abortus. J. Bacteriol. 91:285-296. 1966.-Infectivity of virulent Brucella abortus strain 3183 was less for hamster macrophages after a 2-hr adsorption period than for an attenuated strain (S19) and its tissue culture variant (30). Both strains S19 and 30 were very toxic for the cells, but 3183 was not toxic. Two types of L forms were recovered from a large percentage of hamster kidney cell cultures when disintegration of infected cells was accelerated by tissue culture medium of high pH. One type grew in finely granular microcolonies, was isolated from cells infected for short periods of time, and often reverted to the bacterial form. The other type occurred in small irregularly shaped forms which later developed into round bodies. Both stained specifically with fluorescein-conjugated B. abortus antiserum. Semisolid media containing 0.7% agar provided optimal subsurface L-form growth. L forms also grew well in Thioglycollate Medium but grew poorly in other liquid media. Surface L-form growth was supported by several agar media, but CO(2) was required for optimal growth. Monolayers infected with strain 3183 and examined immediately after adsorption contained occasional small, round bodies. Bizarre forms increased in number with time and, after 24 to 72 hr, large pink-staining inclusions were often present which persisted for several days. Also appearing at about the same time were smaller, dark-staining forms which were first seen in clusters but later dispersed and finally occurred in chainlike configurations. Direct fluorescent-antibody stains of infected cells established that the intracellular forms were related to the infecting strain of B. abortus.     

The spermatheca of Melanoplus sanguinipes (Fabr.). I. Morphology,histology, and histochemistry

The spermatheca of Melanoplus sanguinipes consists of a preapical and an apical diverticulum, and a long, thin ductus seminalis. Histologically, the three components are identical. The wall of the spermatheca includes a basement membrane, secretory and epithelial cells, and a cuticular intima. Small, discrete bundles of muscle occur outside the basement membrane. In each secretory cell is a large central cavity which connects with a cuticular channel (efferent ductule) running through the epithelial cell to the spermathecal lumen. During sexual maturation, light- and dark-staining vesicles accumulate in the secretory cells and discharge their contents into the central cavity. Simultaneously, glycogen accumulates in the epithelial cells. Allatectomy of newly emerged females renders the secretory cells unable to produce material, an effect which can be reversed by topical application of synthetic juvenile hormone. The secretion contains protein and acidic mucopolysaccharide. After insemination the quantities of secretion in the lumen and of glycogen in the epithelial cells diminish in the preapical diverticulum where almost all sperm are stored. As the number of sperm declines, the secretion and glycogen are replenished.     

Effects of pyrimidine-2-thiol on the ovarian histology of Epilachna vigintioctopunctata (Fabr.) (Coleoptera: Coccinellidae)

The telotrophic ovary of Epilachna vigintioctopunctata is composed of 32-40 ovarioles, each with an apical germarium and a basal vitellarium. The germarium encloses mononucleate and binucleate trophocytes, prefollicular tissue and oogonia, while the vitellarium contains 2-5 oocytes arranged in order of maturity. Definite nutritive cords are absent. When females are exposed to 75 mg 4,4,6-trimethyl-1h, 4H-pyrimidine-2-thiol by contact, the trophocytes and the follicular epithelial cells disintegrate to form dark-staining clumps and thus fail to supply nourishment to the developing oocytes, which consequently remain yolk-less and are ultimately reduced to shrunken masses.     

Aggregata dobelli N. Sp. and Aggregata millerorum N. Sp. (Apicomplexa: Aggregatidae) from Two Species of Octopus (Mollusca: Octopodidae) from the Eastern North Pacific Ocean

ABSTRACT. Gamogony and sporogony of two new species of Aggregata (Apicomplexa: Aggregatidae) commonly were observed during histopathological examination of the digestive tracts of octopuses from the National Aquarium in Baltimore. North Pacific giant octopus, Octopus dofleini martini Pickford 1964, from British Columbia and Washington state were infected with Aggregata dobelli n. sp. Sporocysts were smooth-surfaced, dark-staining, subspherical to subovoid, typically 18–31 μ m long by 15–27 μ m wide, and contained 9–22 sporozoites, 18–23 μ m long. California two-spotted octopus, Octopus bimaculoides Pickford and McConnaughey 1949, from California were infected with Aggregata millerorum n. sp. Sporocysts were smooth-surfaced, dark-staining, and subspherical to subovoid, 12–20 μ m long by 11–17 μ m wide, and contained 8–10 sporozoites, 18–31 μ m long. Both species infected the noncuticularized spiral caecum and intestine; A. millerorum n. sp. also infected the cuticularized esophagus and crop. Both parasites were present in the submucosa, muscularis, and serosa. Our observations of Aggregata infections in cuticularized regions of the gut and in the muscularis and serosa appear to be novel. Associated pathologic features included hypertrophy of invaded cells, edema, inflammation, and ulceration.     

SYNAPTONEMAL COMPLEXES IN RED ALGAE1,2

The presence of synaptonemal complexes in the nuclei of young tetraspore mother cells is described for the first time in the red algae. Synaptonemal complexes were found in Janczewskia gardneri Setchell, Levringiella gardneri Setchell, Gonimophyllum skottsbergii Setchell, and Polycoryne gardneri Setchell. The synaptonemal complexes consist of 2 lateral, dark-staining elements from which small fibrils extend to form a less densely staining central element. With minor variations, the dimensions and structure of these synaptonemal complexes correspond to those found in other organisms.     

Observations concerning the staining properties of the macroconidia of certain dermatophyton species.

Staining of the macroconidia of several Dermatophyton species by lactophenol-cotton blue was investigated. Young macroconidia stain variably; their cytoplasm may appear homogeneous or inhomogeneous. The possible explanation seems to be variation in the composition of the cytoplasm. In some macroconidia dark-staining filament was seen along the longitudinal axis. Mature macroconidia showed basal or basal+apical homogeneous deep staining. The intensive apical staining suggests that the apical structure differs from the structure of the side wall.     

Leaf anatomy of Bruniaceae: ecological, systematic and phylogenetic aspects

CARLQUIST, S., 1991. Leaf anatomy of Bruniaceae: ecological, systematic and phylogenetic aspects. Quantitative and qualitative data are given for 60 species of the 12 genera of Bruniaceae; most data are based on liquid-preserved material. Leaves of Bruniaceae are basically linear (broader forms are probably derived) with an apicula that contains phellogen activity. Most bruniaceous leaves have some degree of isolateral construction, with transition to normal bifacial construction in a few species, but more commonly transition to 'inverse' bifacial structure (stomata on adaxial face, palisade on abaxial face). The latter type is correlated with the tendency for leaves to be appressed to stems. Tannins and very likely other dark-staining materials are very characteristic of mesophyll cells. Six genera have a large strand of fibres on the midvein and rhomboidal crystals in bundle sheath cells. The other six genera have few or no fibres on veins and have druses in mesophyll cells (but not in bundle sheath cells). These distinctions may relate to intrafamilial taxonomy, but they also support the primitive position usually accorded to Audouinia, Thamnea and Tittmannia. A key to genera based on leaf antomy is offered. Details of epidermal cell shape, cuticular relief and trichome form and structure based on scanning electron microscopy are given. Leaf anatomy, combined with other features, favours a relationship between Bruniaceae and Grubbiaceae in particular and in broader contexts allies Bruniaceae to rosalean and possibly hamamelidalean families.     

Development of Haemogregarina pestanae in the toad Bufo regularis*

SYNOPSIS. Haemogregarina pestanae França, 1910, is apparently rare in Egypt, having been found in 1 toad Bufo regularis Reuss out of 689 examined. Capsulated capped, young thin, and young and advanced broad forms were present in the peripheral blood. Schizogony occurred in the liver. Two types of schizonts were present—macroschizonts producing 150 or more elongate oval merozoites surrounding a large residual body, and microschizonts producing 60 or less banana-shaped merozoites often radiating from a small, eccentric residual body. Merozoites of the first type developed into a large broad form representing early schizonts of the second type. The latter developed into thin young intraerythrocytic forms and apparently later into encapsulated capped gametocytes. H. pestanae, H. aegyptia and H. tunisiensis all occur in toads (Bufo regularis for the first two, and B. mauritanicus for the third), and produce characteristic encapsulated looped gametocytes in peripheral blood. The capsules contain dark-staining material condensed into a single well-developed cap in H. aegyptia and 1 or 2 much smaller caps in H. pestanae; this material is scattered regularly around the parasite in H. tunisiensis. The capsule of H. pestanae is more or less cylindrical along most of its length, more slender and slightly shorter than the regularly oval capsule of H. tunisiensis or the spindle- or egg-shaped capsule of H. aegyptia.     

Basal cell adenocarcinoma of the salivary gland: report of a case with morphology on fine needle aspiration cytology

BACKGROUND: Basal cell adenocarcinoma of the parotid is rare and prone to recur. CASE: A 54-year-old woman had a history of afacial mass 12 years earlier that had been excised and was diagnosed as low grade adenocarcinoma of the parotid. Over the years, the patient had multiple local and lymph node recurrences. Histology of the excised local recurrent tumor showed basal cell adenocarcinoma, and FNAC of a separate recurrent nodule was performed. The aspirate showed moderate cellularity of basaloid cells with mildly pleomorphic nuclei, small nucleoli and occasional mitotic figures. The cells were mostly single, but some formed clusters with a rosettelike pattern of tumor cells surrounding central eosinophilic globules. A second, less prominent population of smaller cells with dark-staining nuclei was also noted. The differential diagnosis included adenoid cystic carcinoma, polymorphous low grade adenocarcinoma, and basal cell and pleomorphic adenoma. CONCLUSION: The cytologic features of basal cell adenocarcinoma are not distinctive, but the presence of two cell populations with moderate pleomorphism and a rosettelike pattern with central, eosinophilic globules may assist with its differentiation from other salivary gland neoplasms.     

CELL DIVISION AND FILAMENT FORMATION IN THE DESMID BAMBUSINA BREBISSONII (CHLOROPHYTA)1

Cell division and semicell expansion in the filamentous desmid Bambusina brebissonii Kütz. were investigated using transmission and scanning electron microscopy. Interphase cells are typical of desmids, containing a full complement of organelles and a cell wall penetrated by complex pores, but the cells lack a well-defined median constriction. Cell division involves an open spindle and the centripetal growth of a primary septum formed by the fusion of small, dark-staining vesicles probably derived from dictyosomes. Telophase nuclei are separated by a system of interzonal microtubules and numerous large, lighter-staining vesicles also derived from the dictyosomes. Following cell division, an elaborate replicate cross wall is formed which consists of both primary and secondary wall layers. During semicell expansion, a portion of the primary wall splits apart as the new semicells evaginate and expand to their full size. The primary wall stops splitting at a thick ring of secondary wall material leaving the cells united by the remaining common layer of primary wall. When semicell expansion is completed, the primary wall is not shed from the lateral walls of the new semicells, and pores through both primary and secondary wall layers begin to produce sheath material. However, pores in the end walls of cells do not function unless the filament is broken. The intact primary wall between cells and the absence of sheath production between cells comprise the mechanism serving to hold the cells of Bambusina brebissonii together in long filaments.     

ULTRASTRUCTURE OF CARPOSPOROGENESIS IN THE PARASITIC RED ALGA FAUCHEOCOLAX ATTENUATA SETCH. (RHODYMENIALES,RHODYMENIACEAE)

Carpospore differentiation in Faucheocolax attenuata Setch. can be separated into three developmental stages. Immediately after cleaving from the multinucleate gonimoblast cell, young carpospores are embedded within confluent mucilage produced by gonimoblast cells. These carpospores contain a large nucleus, few starch grains, concentric lamellae, as well as proplastids with a peripheral thylakoid and occasionally some internal (photosynthetic) thylakoids. Proplastids also contain concentric lamellar bodies. Mucilage with a reticulate fibrous substructure is formed within cytoplasmic concentric membranes, thus giving rise to mucilage sacs. Subsequently, these mucilage sacs release their contents, forming an initial reticulate deposition of carpospore wall material. Dictyosome vesicles with large, single dark-staining granules also contribute to wall formation and may create a separating layer between the mucilage and carpospore wall. During the latter stages of young carpospores, starch is polymerized in the perinuclear cytoplasmic area and is in close contact with endoplasmic reticulum. Intermediate-aged carpospores continue their starch polymerization. Dictyosomes deposit more wall material, in addition to forming fibrous vacuoles. Proplastids form thylakoids from concentric lamellar bodies. Mature carpospores are surrounded by a two-layered carpospore wall. Cytoplasmic constituents include large floridean starch granules, peripheral fibrous vacuoles, mature chloroplasts and curved dictyosomes that produce cored vesicles which in turn are transformed into adhesive vesicles. Pit connections remain intact between carpospores but begin to degenerate. This degeneration appears to be mediated by microtubules.     

Cutin plays a role in differentiation of endosperm-derived callus of kiwifruit

Cutin fluorescence, after auramine O treatment, was detected on the surface of organogenic areas (protuberances) of endosperm derived callus induced on Murashige and Skoog medium with thidiazuron (0.5 mg l⁻¹) in darkness. Electron micrographs of the protuberances revealed cuticle, visible as a dark-staining layer, and amorphous waxes on the cell wall. In some cases the cells of the epidermis-like layer and shoot buds at early stages of development showed thick and characteristically wavy cutin. This waviness corresponds with the wrinkled appearance of the cell wall as observed by scanning electron microscopy. The role of multivesicular bodies in cutin production and transfer to the plasma membrane is discussed.     

AMPHIESMAL ULTRASTRUCTURE OF DINOFLAGELLATES: A REEVALUATION OF PELLICLE FORMATION1

The ultrastructure of the amphiesma during pellicle formation was investigated in two species of Dinophyceae, Amphidinium rhynchocephalum Anissimowa and Heterocapsa niei (Loeblich) Morrill & Loeblich using thin sections. In both species the amphiesma consists of an outermost membrane (i.e. the plasma membrane) underlain by amphiesmal vesicles. In A. rhynchocephalum the latter appear empty whereas each amphiesmal vesicle in H. niei contains a thecal plate and a thin, amorphous layer (dark-staining layer) located between, the thecal plate and the inner amphiesmal vesicle membrane. When cells of both taxa are carefully fixed, amphiesmal vesicles are always separate entities (i.e. the sutures are undisrupted). During ecdysis the following amphiesmal components are shed: the plasma membrane, the outer amphiesmal vesicle membrane, and in H. niei the thecal plates. The inner membranes of the amphiesmal vesicles then fuse with each other and form a continuous membrane (termed pellicle membrane) that remains tightly oppressed to an underlying amorphous layer (pellicular layer). In A. rhynchocephalum the pellicular layer is already present in vegetative non-ecdysed cells, whereas in H. niei it forms during ecdysis beneath the pellicle membrane. During ecdysis in H. niei, material from the dark-staining layer precipitates on the outer surface of the pellicle membrane, where it forms a characteristic honeycomb pattern. The new observations are incorporated into a revised model of pellicle formation in dinoflagellates and contrasted with earlier proposals.     

A novel temperature-sensitive mammalian cell line exhibiting defective prophase progression

A temperature-sensitive mammalian cell line has been isolated which grows and divides normally at the permissive temperature of 33°C. When incubated at 39°C, the nonpermissive temperature, interphase cells continue to enter a prophase-like state. Chromatin-like material condenses and coalesces into dark-staining clumps rather than into discernible chromosomes. Disappearance of the nuclear boundary is observed, but re-formation of the boundary around the clumps fails to occur. Incorporation of labeled precursors reveals a decrease in protein synthesis which is accompanied by a slower decrease in DNA synthesis. Approximately 0.2% of the mutant cells revert in their capability of growth and cell division at 39°C. These “revertants” are found to contain a higher number of chromosomes. The isolation of this mutant is based on the initial observation that the cells become rounded at the nonpermissive temperature. The cell-rounding process characteristic of mitotic cells should serve as a useful marker in the isolation of mitotic mutants.