Appendages of Clostridium bifermentans Spores

Four distinct spore appendage types were detected in an electron microscope survey of 12 strains of Clostridium bifermentans. A smooth tubular appendage and a feather-like appendage are described in detail. In addition, hirsute tubular appendages and small pin-like appendages are depicted. Spores of four strains apparently lack appendages.     

Membrane tubules attach Salmonella Typhimurium to eukaryotic cells and bacteria

Using scanning electron microscopy techniques we measured the diameter of adhesive tubular appendages of Salmonella enterica serovar S. Typhimurium. The appendages interconnected bacteria in biofilms grown on gallstones or coverslips, or attached bacteria to host cells (human neutrophils). The tubular appendage diameter of bacteria of virulent flagellated C53 strain varied between 60 and 70 nm, thus considerably exceeding in size of flagella or pili. Nonflagellated bacteria of mutant SJW 880 strain in biofilms grown on gallstones or coverslips were also interconnected by 60-90-nm tubular appendages. Transmission electron microscopy studies of thin sections of S. Typhimurium biofilms grown on agar or coverslips revealed numerous fragments of membrane tubular and vesicular structures between bacteria of both flagellated and nonflagellated strains. The membrane structures had the same diameter as tubular appendages observed by scanning electron microscopy, indicating that tubular appendages might represent membrane tubules (tethers). Previously, we have shown that neutrophils can contact cells and bacteria over distance via membrane tubulovesicular extensions (TVE) (cytonemes). The present electron microscopy study revealed the similarities in size and behavior of bacterial tubular appendages and neutrophil TVE. Our data support the hypothesis that bacteria establish long-range adhesive interactions via membrane tubules.     

The renal chloride cell of the fresh-water catfish,Parasilurus asotus,with special reference to the tubular membrane system

The kidney of the fresh-water catfish, Parasilurus asotus, was examined by electron microscopy. A special type of cell, very similar in appearance to the chloride cell of the teleostean gill filaments, is found in the kidney and is referred to as a renal chloride cell. This cell is characterized by an extensive tubular membrane system with a rather constant diameter of approximately 600 A. A number of mitochondria are closely associated with this system. Application of ruthenium red as an extra-cellular space marker revealed that the tubular system is a highly organized derivative of the cell membrane, infolded from the basal and lateral surfaces of the cell. The fine structural resemblance to other types of cells known to possess active transport of electrolytes suggests that these cells are involved in intrarenal osmoregulation.     

Role of polycystins in renal tubulogenesis

Every day, human renal tubules process 140 l of glomerular filtrate into 1 l of urine. They accomplish this by the coordinated function of distinct cell types occupying specific positions along the tubules. This precisely defined structure requires tight regulation of morphogenesis. A group of disorders termed polycystic kidney disease (PKD) is characterized by altered tubular morphology. Mutating genes involved in PKD results in renal tubules that either fail to form properly or 'forget' how to maintain their 'correct' diameter. Study of PKD proteins will elucidate the process of renal tubular morphogenesis and guide the development of therapies. Here, we focus on insights provided by study of the most common form of PKD, autosomal dominant PKD.     

Morphology of the petal inAconitum

The petals ofAconitum were classified into six types. Type I: the labium tubular at the base and no appendage inside. Type II: a lambda (A)-shaped enation present inside the limb. The upper part of the enation is situated at the lower edge of the spur mouth and both wings of the enation extend to margins of the labium. Type III resembles type II but both wings do not extend to the margins. Type IV: a small flap attached at the lower edge of the spur mouth. Type V: two auriculate appendages present on both lateral walls of the labium. Type VI: without inside appendage. Most species of sect.Lycoctonum have type I petal and those of sect.Aconitum have type V petal. Type I is distinctly cup-shaped or peltate with a well developed cross zone or adaxial wall and type II is a modification of type I. Type VI is distinctly flat or epeltate without the cross zone. Others are intermediate between cup-shaped and flat or peltate and epeltate types. Based on the observation of petal ontogeny onA. pterocaule var.glabrescens, A. vulparia andA. japonicum var.eizanense, the relation among these types was explained by the partial or total reduction of the adaxial meristematic regions.     

A multivariate analysis of measurements on the Scottish Middle Old Red Sandstone antiarch fish genus Pterichthyodes Bleeker

A multivariate statistical analysis, using both discriminatory procedures on canonical axes and factor analysis was used to determine if there was any separation into different morphological types corresponding to the ostensible species of the Scottish antiarch Pterichthyodes. These analyses indicated that, although there were two definite types of pectoral appendage, those differences which were apparent in body shape, were part of a continuous variation exhibited by the whole population, and were but extreme forms of a continuum. The distinction in pectoral appendage types is attributed to sexual dimorphism.     

经食道超声心动图评估特发性房颤左心房左心耳的价值

目的:研究经食道超声心动图(TEE)评估特发性房颤左心房左心耳的临床价值。方法:选择自2015年1月到2016年8月在医院接受诊治的特发性房颤患者100例纳入本次研究,阵发性房颤92例,记为阵发性房颤组;持续性房颤8例,记为持续性房颤组。另选同期在医院进行健康体检的心功能正常志愿者90例作为对照组。利用TEE对受试者进行检查,对比房颤组与对照组的左心房及左心耳参数,是否含有自发性显影(LASEC)的房颤患者的左心房及左心耳参数,利用TEE分析对房颤患者的预后情况。结果:阵发性房颤组左心房的前后径和左右径,左心耳血流最大的排空速度(Lev)均明显小于对照组,左心耳的面积变化率及最大的充盈速度(Lfv)均明显大于对照组,差异有统计学意义(P0.05)。持续性房颤组左心房的前后径和左右径均明显大于对照组,左心耳的面积变化率、Lev及Lfv均明显小于对照组,差异有统计学意义(P0.05)。阵发性房颤组左心房的前后径和左右径均明显小于持续性房颤组,左心耳的面积变化率、Lev及Lfv均明显大于持续性房颤组,差异有统计学意义(P0.05)。有LASEC者左心房的前后径和左右径均明显大于无LASEC者,左心耳的面积变化率、Lev及Lfv均明显小于无LASEC者,差异有统计学意义(P0.05)。100例房颤患者中发现34例LASEC,占34.00%,其中有18例患者合并有左心耳血栓,占18.00%。总计有66例患者接受导管射频消融疗法,占66.00%,均未在术中及术后7d内出现血栓及栓塞并发症。结论:利用TEE对特发性房颤的患者左心房及左心耳进行评估,有利于更好的辅助患者的临床治疗,值得重视。     

Spore Appendages and Taxonomy of Clostridium sordellii

Twenty-five strains of Clostridium sordellii were divided into two groups on the basis of spore fine structure. Sixteen strains formed spores with smooth tubular appendages, and nine strains formed spores which lacked appendages. The other properties of the 25 strains were relatively constant. Since the minor strain variability which was encountered did not correlate with spore appendage status, fragmentation of this species on the basis of spore appendage status is not advocated.     

Erysiphe wadae: a new species of Erysiphe sect. Uncinula on Japanese beech

 A new species of Erysiphe sect. Uncinula is described and illustrated from Japan. Erysiphe wadae sp. nov., found on Japanese beech (Fagus crenata, Fagaceae), is characterized by having two types of appendages, i.e., a long (true) appendage arising from the equatorial zone of the ascomata, and a short appendage arising from the upper part of the ascomata. This characteristic is shared by E. simulans, E. australiana, E. flexuosa, E. liquidambaris, E. prunastri, and E. togashiana. Erysiphe wadae differs from the latter five species in its brown-colored appendage. Erysiphe simulans is most similar to E. wadae, but differs in its loosely uncinate appendage and smaller number of ascospores. Identity of the nucleotide sequences of the rDNA ITS region is 92.3% between the two species. The significance of the two types of appendage in taxonomy and phylogeny of powdery mildews is discussed based on molecular phylogenetic analysis. Received: November 8, 2002 / Accepted: January 29, 2003 Acknowledgments We are grateful to Drs. Yukio Harada and Hideki Naito for help in collecting powdery mildew specimens; Dr. Uwe Braun for providing the specimen of E. flexuosa; and Mr. Tetsuya Hirata and Miss Sanae Matsuda for nucleotide sequences of E. togashiana and E. flexuosa. This work was partially supported by a Grant-in-Aid for Scientific Research (No. 13660047) from Ministry of Education, Culture, Sports, Science and Technology, Japan.     

Variability of the Left Atrial Appendage in Human Hearts

Atrial fibrillation increases the risk of thrombus formation. It is commonly responsible for cerebral stroke whereas less frequently for pulmonary embolism. The aim of the study was to describe the morphology of the left atrial appendage in the human heart with respect to sex, age and weight. Macroscopic examination was carried out on 100 left appendages taken from the hearts of the patients aged 18–77, both sexes. All hearts preserved in 4% water solution of formaldehyde carried neither marks of coronary artery disease nor congenital abnormalities. Three axes of appendage orientation were performed. After the appendage had been cut off, morphological examination was performed in long and perpendicular axes. Measurements of the appendages were taken from anatomical specimens and their silicone casts. We classified the left atrial appendage into 4 morphological groups according to the number of lobes. Most left atrial appendages in female population were composed of 2 lobes. In the male group typically 2 or 3-lobed appendages were observed. The mean left atrial appendage orifice ranged from 12.0 to 16.0 mm and the most significant difference in the orifices between males and females was observed in LAA type 2 (about 3.3 mm). A smaller orifice and narrower, tubular shape of the LAA lobes could explain a higher risk of thrombus formation during nonvalvular atrial fibrillation in women. Knowledge of anatomical variability of the LAA helps diagnose some undefined echoes in the appendage during transesophageal echocardiographic examination.     

The architecture of the anterior appendage in the egg of the assassin bug, Zelus longipes (Hemiptera: Reduviidae)

The eggshell of Zelus longipes, a Hemiptera species of the family Reduviidae (assassin bugs), has been studied using Scanning Electron Microscopy (SEM). The emphasis was on the architecture of an anterior appendage connected to the main eggshell of both ovarian and deposited eggs. The analysis of eggs fractured at various angles and levels reveals a relatively complex organization of this appendage. There is a cylindrical outer layer, the veil, of roughly the same diameter as, and continuous with, the main eggshell. At its anterior pole, the veil folds inwards and forms an hourglass-shaped tube that is attached through slender extensions to a curved plate oriented at right angles to the long axis of the egg and spanning the internal diameter of the veil. The plate is solid at the center, shows honeycomb-shaped perforations in its mid-section and contains a very delicate meshwork along its circumference. Underneath the plate lies a hollow cylinder oriented at right angles to the long axis of the egg and attached to the anterior plate of the egg, the operculum. The outer openings of aeropyles lie at the inner face of the veil and at its base. While the outer surface of the entire eggshell appears smooth, the inner face of the anterior appendage is highly and diversely sculptured. The eggs are deposited in batches of at least 15 and completely surrounded by viscous secretion. This substance does not encroach on the anterior appendage. The major function of this appendage may lie in the protection of the aeropyles and particularly in preventing their being clogged by the viscous material.     

Replacement of the preoccupied name Davisia Laird 1953 and description of a new myxozoan species (Myxosporea: Sinuolineidae) from Sebastiscus marmoratus (Cuvier, 1829) in the East China Sea

The myxozoan genus Davisia Laird 1953 is preoccupied by Davisia Del Guercio 1909 (Insecta: Hemiptera). Here, Myxodavisia nomen novum is proposed to replace the preoccupied name, and a new species is described. Myxodavisia sebastisca n. sp. was found in the urinary bladder of Sebastiscus marmoratus, collected from coastal waters off Xiamen in the East China Sea. The parasite is characterized by a disporous trophozoite; spherical to subspherical spore, 13.1 +/- 0.3 (12.7-13.6) by 12.3 +/- 0.9 (10.9-13.5) microm in size; curved sutural line; 2 shell valves each with a long lateral appendage 119.4-335.2 microm in length; and 2 spherical or subspherical polar capsules, equal in size, 4.6 +/- 0.6 (3.2-4.6) microm in diameter. Traditionally, Myxodavisia is distinguished from Ceratomyxa, Sinuolinea, and Sphaerospora spp. by having spores that possess a distinct central chamber and lateral appendages. A review of the literature reveals that the presence or absence of a clear septum between these spore components is open to interpretation. Indeed, in immature spores of M. sebastisca n. sp., there was an indication of a demarcated appendage, but in some mature spores, no clear separation was apparent. Our findings suggest that future revision of this genus is warranted, particularly once DNA sequence data become available.     

Lower Cretaceous (Albian) shell-armoured and associated echinoid trace fossils from the Sácaras Formation, Serra Gelada area, southeast Spain

The Sácaras Formation (Albian, Lower Cretaceous) of the Serra Gelada succession (Prebetic of Alicante), southeast Spain, comprises carbonate‐rich, upwards thickening parasequences in which many types of trace fossils have been identified. The present study focuses on two types of tubular trace fossil characterized by features of their external coating. The first type is represented by a shell‐covered, structured trace fossil, up to 4?cm in diameter and 40?cm in length, built horizontally, from rectilinear (type 1) to gently curved (type 2), which envelopes an unstructured pipe of grey silty sediment. The coating is characterized by imbricated, flat particles, mainly orbitolinid foraminifers and other planar bioclasts, forming thin concentric layers; in cross section the bioclasts produce a typical plumed structure. This trace fossil represents a new ichnogenus and ichnospecies, here named Ereipichnus geladensis. Particle arrangement of the external coating is similar to that of terebelloid tubes, but Ereipichnus is a horizontal trace fossil, whereas structured worm tubes are vertical. The second type is a grain‐coated trace fossil, tubular in shape, with a simple internal structure. The coating is often reddish with respect to the neighbouring dark grey sediment and shows a slightly coarser‐grained texture, which envelopes the internal muddy pipe. This type, which yielded echinoids, was produced by irregular or heart‐shaped sea‐urchins (spatangoids) and is attributed to Scolicia or Cardioichnus. Facies analysis of the Serra Gelada succession with Ereipichnus and Scolicia or Cardioichnus locally shows other types of branched trace fossils (primarily represented by different forms of Thalassinoides) and bioturbation is developed in tiers, increasing upwards in abundance and diversity.     

Gustatory stimulation of a homeotic mutant appendage,Antennapedia, inDrosophila melanogaster

Summary The proboscis extension response was used to prove the leg identity of chemosensory neurons in the homeotic appendage of theDrosophila mutantAntennapedia (Antp ^73b). The data suggest that the homeotic appendage, which is morphologically characterized as a mesothoracic leg, corresponds to a mesothoracic leg as well when considering its gustatory responsiveness (Figs. 1A, B; 3A, B). The neuronal pathway which might mediate the reflex between homeotic chemoreceptors and motor neurons responsible for the proboscis extension is discussed.     

Ultrastructural study of the alveolar-capillary membrane and the tubular endoplasmic reticulum in alveolar type I cells of the caprine lung

The ultrastructural features of alveolar type I cells of the goat lung were studied by using vascular perfusion and direct airway instillation of fixatives. The morphological features of smooth endoplasmic reticulum (SER) were characterized by measuring the diameter of individual SER tubules which conformed in size and appearance to the tubular endoplasmic reticulum (TER) already described in various types of epithelium. The TER appeared as large tubular aggregates in a palisade arrangement; these aggregates ramified into various areas of the extended cytoplasm of alveolar type I cells. The TER also existed as a mixture of short cisternae and vesicles, and glycogen alpha particles were present in the non-perikaryonic portion of the cell. The different forms of TER had varying relationships to the plasmalemma. The interchangable configurations seen in the structure of TER indicated the functional modalities of the cells and were comparable to similar structural modifications in electrolyte-secreting cells. The role of TER, microtubules, and large populations of endocytic vesicles in the alveolar type I cells in the goat lung is examined in the context of physiological eructation of rumenal gases and the absorption of electrolyte-rich fluids which escape into the lung at each eructation in ruminants.     

Le spermatozoide de Ophidion sp. (Poisson,téléostéen): Particularités ultrastructurales du flagelle

The spermatozoon of Ophidion sp. possesses an elongated nucleus 8 μm long, a short midpiece (0,6 μm), and a long flagellum (100 μm). The flagellar membrane extends in the form of two diametrically opposed sidefins. Evolving spermatids and spermatozoa are found in the lumen of the seminiferous tubes. The sections of flagella show filamentary and tubular elements disposed parallel to the axoneme microtubules. We have divided the flagella into three types. In type 1 the tip of the sidefins contains 20 to 30 filaments 5 run in diameter and between these and the axoneme 20 to 30 tubular elements 15 to 20 nm in diameter. Type 2 possesses a dense cytoplasm and a few tubular elements 10 nm in diameter disposed at the tip of the sidefins. Type 3 contains a cytoplasm which is not dense and in which we found polysaccharides and 1 to 8 tubular elements forming a palisade which lines the plasma membrane at the tip of the sidefins. We interpret these three types as three successive stages in the organization of the flagellum during spermiogenesis. Type 3 corresponds to the spermatic flagellum. These 10-nm-diameter tubules do not have the same chemical composition as the microtubules. Elements of the cytoskeleton serve as a support for the sidefins.     

Some ultrastructural features ofPlanctomyces bekefii,morphotype I of theBlastocaulis-Planctomyces group of budding and appendaged bacteria

The ultrastructure ofPlanctomyces bekefii, a budding and appendaged bacterium, has been examined using samples obtained directly from pond water, its natural habitat. The prokaryotic nature of this morphologically unusual microbe was verified by observations of thin sections. Its major appendage, the nonprosthecate stalk, is shown to have a tubular structure, with a substructure of hollow fibers. Some details of the budding process and other ultrastructural features are presented.     

Clostridium Spores with Ribbon-like Appendages

Spores of Clostridium sp. N1 are characterized by numerous broad ribbon-like appendages attached to one end. The appendages are two to three times the length of the spore and, at their maximal dimension, may be two-thirds the width of the spore. They are attached to the spore body by a common trunk which is continuous with the outer spore coat. Each appendage is a multilayered structure and is enclosed in an amorphous material. Details of spore and appendage formation are described, and appendage ultrastructural features are presented. The function of the appendages is not known.     

Morphology and evolution of the respiratory apparatus in the family Eubelidae (Crustacea,Isopoda, Oniscidea)

The morphology of the respiratory apparatus in the pleopodal lungs of the family Eubelidae was investigated. The family is a monophyletic group including more than 240 species in 53 genera (three of which are nomina dubia), mostly distributed in the Afrotropical Region (tropical Africa and Arabian Peninsula). In all the Eubelidae, except for the monospecific genus Parelumoides and two species of the genus Elumoides, the exopods of pleopods have lungs. All the pulmonary morphologies present in the entire suborder Oniscidea are found: 1) uncovered lungs, composed of a pleated respiratory surface, directly exposed to the air (Atracheodillo-type) or partially enclosed within the appendage (Synarmadilloides-type); 2) covered lungs with several spiracles and respiratory trees, housed within the appendages, with spiracles surrounded by a specialized, nonrespiratory, structure (perispiracular area) (Eubelum- and Somaloniscus-types); 3) covered lungs with only one spiracle, with or without perispiracular area, and one respiratory tree (Aethiopopactes- and Periscyphis-types), which in taxa with Periscyphis-type lung crosses the insertion of the appendage and penetrates into the pleon with bundles of respiratory tubules. The evolution of the various types of lungs is discussed. It is concluded that the two main evolutionary lines, i.e., uncovered lungs and covered lungs, originated independently from an ancestral respiratory structure-the semilunar area. A first mechanism of development of the semilunar area by folding of its surface produced the Atracheodillo-type (all folds coplanar with the surface of the exopod) and Synarmadilloides-type (folds partly coplanar and partly intraflexed inside the exopod) uncovered lungs. A second mechanism of development by tubular invagination of the cuticle of the semilunar area produced the polyspiracular Eubelum-type lungs (numerous arborescent invaginations) and the monospiracular Aethiopopactes-type lungs (only one arborescent invagination), probably passing through a common intermediate pattern. From the common pattern, both the poly- and monospiracular types would have inherited the characteristic concave cell arrangement of the perispiracular area. The Somaloniscus-type and Periscyphis-type lungs are forms specialized for arid environments, directly derived from the Eubelum-type and Aethiopopactes-type, respectively.