Characteristics of two cell lines derived from a histologically undifferentiated bronchial carcinoma expressing neuroendocrine markers

Summary This study investigates the characteristics of two human cell lines—1PT and 1PT VARIANT A—both derived from the same histologically undifferentiated, neuroendocrine positive, non-small cell lung carcinoma (NSCLC) and capable of growth in unsupplemented serum-free minimum essential medium. In stationary culture, the cells of both lines grew both attached to a plastic substratum and in suspension; the 1PT VARIANT A line formed three-dimensional clusters of loosely adherent cells. The cell lines differed in their DNA content, the 1PT having 1.44 times and the 1PT VARIANT A having 2.39 times the normal human diploid DNA content. Chromosome counts supported this observation, the ploidy of the 1PT and VARIANT A lines being 1.11 and 1.64, respectively. On transmission electron microscopy the cells of both lines had dense core granules and immature desmosomes, whereas only the 1PT VARIANT A line had mucin granules. Both lines formed, in nude mice, tumors that, like the original tumor from which they were derived, were histologically undifferentiated and showed local invasion. The original tumor and both lines had demonstrable neuroendocrine markers. Cytokeratins were apparent in the tumor but not the cell lines, and neurofilaments were present in the cell lines only. Staining for epithelial membrane antigen, neural cell adhesion molecule, and desmoplakin differentiated between the two lines. These lines provide a useful model for the investigation of the biology of the neuroendocrine positive subgroup of NSCLC, which is clinically important because of the possible responsiveness of these tumors to chemotherapy.     

Ciliated epithelium in the gut of larval Atlantic halibut, Hippoglossus hippoglossus

The presence of cilia was documented in the hindgut of larval Atlantic halibut ( Hippoglossus hippoglossus ) with the use of electron microscopy. Cilia were shown to be present as late as 8 and 9 day post hatch. These observations were compared to similar observations in more primitive teleosts.     

Histo-cytological study of the liver of the cabrilla sea bass, Serranus cabrilla (Teleostei, Serranidae), an available model for marine fish experimental studies

Livers of juvenile cabrilla sea basses ( Serranus cabrilla ) were subjected to light and electron transmission microscopy following different periods of maintenance in an aquarium. Since this fish is easy to feed in captivity and the hepatic structure was found to be comparable at the four periods tested (0, 5, 10 and 20 days), both at the histological and ultrastructural level, the liver of S. cabrilla could be an available model for marine contamination experimental studies. As in other fish species, it is not possible to distinguish the portal lobules and the triads. The Melano-Macrophage Centres contain tipofuscins, ceroids and haemosiderin, but they do not contain any melanin. The hepatocytes are arranged in cords (two cells thick), and, at the ultrastructural level, they show numerous microvilli in the perisinusoidal and canalicular areas. The hyaloplasm includes a considerable amount of glycogen and some lipid droplets are occasionally observed. Mitochondria, rough endoplasmic reticulum and the Golgi apparatus are relatively scarce.     

Ultrastructure of the primary gill lamellae of Scomber australasicus

The ultrastructure of the primary epithelium, and the efferent half of the subepithelium, of the primary gill lamellae of slimy mackerel ( Scomber australasicus ) is described. The following cells are identified and described: light nucleated epithelial cells (surface and basal), dark nucleated cells, mucous cells, acidophilic cells, type 1 cells, type 2 cells, type 3 cells and chloride cells in the epithelial region, and subepithelial cells A and B, fibroblasts, chondrocytes, cells of the wall of efferent blood vessel and some blood cells in the subepithelium.     

(蜓)类旋壁超微构造的研究——以麦(蜓)型旋壁为例

光学显微镜下的观察表明(蜒)类的旋壁属于钙质微粒壳类型,对它们的电镜观察揭示了组成旋壁的晶粒的大小、形态和排列方式.对具有致密层和蜂巢层型两层式旋壁的Triticites的电镜研究表明:其致密层由近等轴晶无定向排列而成;蜂巢层由短柱状晶定向排列组成板状复合体,进而组合成管状孔,镶嵌在不定向排列的近等轴品基质中构成.Pseudofusulina的致密层也由近等轴晶不定向排列构成,蜂巢层由粗柱晶定向排列组成纤状复合体,进而形成管状孔,镶嵌在近等轴晶基质中.     

Effect of meteorological variates on persistence of primary conidia and capilliconidia of Erynia radicans (Zygomycotin: ntomophthorales) under natural conditions

Persistence of conidia of an isolate of Erynia radicans (Syn. Zoophthora radicans) was investigated in relation to the meteorological conditions which occurred during autumn-winter of 1990–91 in the coastal plain in Israel. Capilljconidia shielded from the sun, placed on the abaxial surface of leaves of Plumeria acuminata, persisted for 24 h to at least 120 h. Exposed capilliconidia, placed on the adaxial surface of the same leaves, died within 24 h. Almost all the primary conidia shielded from the sun (placed on the abaxial surface of the same leaves) died within a single day. Conidial viability was expressed in subsequent germination on an agar medium. Capilliconidial persistence was closely related to the daily air temperatures, expressed as cumulative day-degrees. Differences in relative humidity had no substantial effect on capilliconidial mortality. At daytime temperatures of ≤ 20°C, mortality after 24 h incubation was lowest (≤ 34%) and the persistence duration, longest (at least 120 h). Increases in daytime temperature up to 24°C for a few hours increased mortality (37–57% after 24 h incubation) and shortened the persistence duration (72–120 h). Exposure to 24–29°C during daytime greatly increased mortality (65–58% after 24 h) and further shortened the persistence duration (24–48 h). Daytime temperatures of > 29°C were lethal to all capilliconidia within 24 h. Temperature had a profound effect on capilliconidial persistence also under controlled environmental conditions. The significance of capiliiconidial persistence is discussed in relation to activity of the fungus in its natural environment.     

Changes in leaf ultrastructure and carbohydrates inArabidopsis thaliana L. (Heyn) cv. Columbia during rapid cold acclimation

Summary We studied cell ultrastructure and carbohydrate levels in the leaf tissue ofArabidopsis thaliana L. (Heyn) cv. Columbia during rapid cold acclimation. Freezing tolerance of the leaves from 26 day old plants was determined after 48 h and 10 days at 4°C. Acclimation treatment of 48 h decreased the lethal freezing temperature from –5.7°C to –9.4°C. Freezing tolerance was not altered further by acclimation at 4 °C for 10 days. Ultrastructural changes in the parenchyma cells were evident after 6 to 24 h of cold acclimation. The plasma membrane showed signs of extensive turnover. Evidence of membrane invaginations and sequestering of membrane material was observed. In addition, numerous microvesicles, paramural bodies, and fragments of endoplasmic reticulum were noticed in the vicinity of plasma membrane. Modifications in the structure of cell membranes were evident after 5 days of exposure to low temperature. Small, darkly stained globules were seen on the plasma membrane, tonoplast, chloroplast envelope membrane, mitochondrion outer membrane, dictyosome cisternae membrane, and microvesicle membrane. As far as we are aware, this type of membrane modification has not been described previously in plant cells exposed to low temperature. We propose to call these structures membraglobuli. Acclimation treatment also increased the concentrations of soluble sugars and starch. These observations suggest that cold acclimation inA. thaliana induces changes in both plasma membrane properties and carbohydrate composition.     

Establishing a new genus,Chiharadinium gen. nov. (Peridiniales,Dinophyceae) for a tidal pool dinoflagellate formerly known as Scrippsiella hexapraecingula

To determine its accurate taxonomic position, a tidal pool bloom-forming dinoflagellate, Scrippsiella hexapraecingula was re-investigated using light, scanning and transmission electron microscopy together with a phylogenetic analysis based on concatenated ribosomal DNA sequences. The culture strains used in this study were established from intertidal rock pool samples taken from Jogashima, Kanagawa prefecture and Heisaura, Chiba prefecture, Japan and were identified as S. hexapraecingula originally described by Horiguchi and Chihara from a tidal pool in Hachijo Island, Tokyo, Japan in 1983. The thecal plate arrangement was determined as Po, X, 4′, 3a, 6″, 6c, 5s, 5″′, 2″″. The internal structure was investigated for the first time. The organism has typical dinoflagellate cellular organelles such as a dinokaryotic nucleus, mitochondria with tubular cristae, trichocysts and pusule. The chloroplast was single and connected to the central pyrenoid (stalked type). The eyespot found in the sulcus is of the B type with two rows of superficial intraplastidal lipid globules directly overlain by an extraplastidal single layer of crystalline bricks enveloped by a common membrane. The apical pore is plugged by a double-layered stub-like structure. Stalk building material for attachment covered the apical pore. Phylogenetic analysis indicated that S. hexapraecingula was most closely related to a freshwater dinoflagellate, Peridiniopsis borgei, the type species of the genus Peridiniopsis. However, clear differences exist between these two organisms, including their thecal plate arrangement, habitat and habit. As a result, a new genus, Chiharadinium Dawut & T. Horiguchi gen. nov. has been proposed rather than attempting to accommodate S. hexapraecingula in the genus Peridiniopsis. The new combination, Chiharadinium hexapraecingulum (T. Horiguchi & Chihara) Dawut & T. Horiguchi comb. nov. has been proposed.     

Description of Chytridiopsis Trichopterae N. Sp. (Microspora, Chytridiopsidae), A Microsporidian Parasite of the Caddis Fly Polycentropus Flavomaculatus (Trichoptera, Polycentropodidae), With Comments On Relationships Between the Families Chytridiopsidae and Metchnikovellidae

ABSTRACT. The microsporidium Chytridiopsis trichopterae n. sp., a parasite of the midgut epithelium of larvae of the caddis fly Polycentropus flavomaculatus found in southern Sweden, is described based on light microscopic and ultrastructural characteristics. All life cycle stages have isolated nuclei. Merogonial reproduction was not observed. the sporogony comprises two sequences: one with free spores in parasitophorous vacuoles, the other in spherical, 5.6-6.8 μm wide, sporophorous vesicles which lie in the cytoplasm. the free sporogony yields more than 20 spores per sporont. the vesicle-bound sporogony produces 8, 12 or 16 spores. the envelope of the sporophorous vesicle is about 82 nm thick and layered. the internal layer is the plasma membrane of the sporont; the surface layer is electron dense with regularly arranged translucent components. Both spore types are spherical. They have an ～ 35-nm thick spore wall, with a plasma membrane, an electron-lucent endospore, and an ～ 14-nm thick electron-dense exospore. the polar sac is cup-like and lacks a layered anchoring disc. the polar filament is arranged in two to three isofilar coils in the half of the spore opposite the nucleus. the coupling between the polar sac and the polar filament is characteristic. the surface of the polar filament is covered with regularly arranged membraneous chambers resembling a honeycomb. There is no polaroplast of traditional type. the cytoplasm lacks polyribosomes. the nucleus has a prominent, wide nucleolus. the two spore types have identical construction, but differ in dimensions and electron density. Free living spores are about 3.2 μm wide, the diameter of the polar filament proper is 102-187 nm, the chambers of the honeycomb are 70-85 nm high, and the polar sac is up to 425 nm wide. Living spores in the vesicle-bound sporogony are about 2.1 μm wide, the polar filament measures 69-102 nm, the chambers of the honeycomb are about 45 nm high, and these spores are more electron dense. Comparisons of cytology (especially the construction of the spore wall and the polar filament and associated structures) and life cycles reveal prominent differences among the Chytridiopsis-like microsporidia, and close relationships between the families Chytridiopsidae and Metchnikovellidae.     

The Nuclear Apparatus of the Ditransversal Ciliate Homalozoon Vermiculare (Ciliophora, Rhabdophora) During Interphase and Division Ii. the Micronuclei and Some Observations On Conjugation

ABSTRACT. The nuclear apparatus of H. vermiculare consists of a single moniliform macronucleus and about 25 micronuclei. the micronuclei are about 3 μm in diameter and characterized by a meshwork of thick condensed chromatin. Mitosis is intranuclear and acentric as in all other ciliates. In metaphase, interpolar and chromosomal microtubules are abundant and the length of the micronuclei increases to about 5 μm. In late anaphase, interzonal microtubules become prominent and the spindle elongates to about 50 μ. In meta- and anaphase, the microtubules of the spindle are attached to the polar vesicles, and in anaphase, chromosomes become attached to it. In contrast to most other eukaryotes, micronuclear mitosis is not strictly bound to cell division in H. vermiculare. While most of the micronuclei divide prior to cytokinesis, others retain their interphasic shape or degenerate. In addition, some micronuclei divide in the interdivision period, i.e. between two successive divisions of the cell and macronucleus. Mating cells of H. vermiculare become joined to each other in the cilia-free region covering the cytostome. In the course of conjugation, the cell membranes and the underlying oral filamentous sheaths of both cells fuse, thus uniting the endoplasm of both cells in the mouth region. Synaptonemal complexes in the meiotic chromosomes are more distinct in H. vermiculare than in most other dilates. the micrographs presented here depict dearly the central filament, transverse elements, and other substructures.