Trilaminar Layer Research Articles

Role of uterine biophysical profile in predicting conception in a sample of infertile women attending an IVF center in Erbil

Background and objective: Failure to get pregnant can be profoundly disappointing, frustrating and eventually lead to a lot of social, medical, and psychological consequences like depression. This study aimed to evaluate the role of uterine biophysical profile in predicting conception in women with a history of infertility. Methods: A prospective diagnostic accuracy study was conducted in Erbil, Iraqi Kurdistan region, in the Maternity Teaching Hospital from October 2019 to September 2020 on 51 women suffering from primary and secondary infertility. Vaginal ultrasound was performed for all the women at mid-cycle and before embryo transfer. The uterine scoring system for reproduction by Applebaum was calculated, and the total score was obtained. Its role in predicting conception was determined. Results: A cut-off of 15 scores of the uterine scoring system for reproduction gave a sensitivity of 86.7% and a specificity of 100%. Factors found to be associated with high rates of pregnancy were endometrial thickness 10-14 mm (P <0.001), distinct trilaminar layer (P <0.001), abundant blood flow within zone 3 (P <0.001), and uterine artery Doppler PI of <2.19 (P <0.001). The last two parameters gave a pregnancy rate of 100%. Conclusion: Applebaum’s uterine scoring system for reproduction is an easy, simple, noninvasive method for predicting pregnancy in women suffering from primary and secondary infertility. Both uterine artery Doppler PI and endometrial receptivity (including thickness, character, and vascularity) are two important parameters in predicting suitable environment for implantation and pregnancy outcome. Keywords: Uterine scoring system for reproduction (USSR); Uterine biophysical profile; In-vitro fertilization (IVF); Intrauterine insemination.

Tripartite Layered Photoanode from Hierarchical Anatase TiO2 Urchin-Like Spheres and P25: A Candidate for Enhanced Efficiency Dye Sensitized Solar Cells

A trilaminar layer photoanode for dye-sensitized solar cells (DSSCs) was constructed using urchin-like TiO2 hierarchical microspheres and P25. The top layer made of hierarchical microspheres enhanced light scattering; the middle layer consisting of P25 and as-prepared microspheres is a multifunctional layer for DSSCs, high adsorption ability to the dye, light scattering ability, and slow recombination rates coexistence; the bottom layer used P25. The DSSCs based on the photoanode with tripartite-layers structure exhibited a much higher short-circuit photocurrent density of 18.97 mA cm–2 and energy conversion efficiency of 8.80%, which indicated a 36% increase in the conversion efficiency compared to those of the P25 electrode (14.51 mA cm–2, 6.50%). The great improvements of photocurrent density and energy conversion efficiency for hierarchical TiO2 microspheres were mainly attributed to a considerable surface area, a higher light scattering ability, and slower electron recombination rates for the former.

One step closer to eliminating the nomenclatural problems of minute coccoid green algae: Pseudochloris wilhelmii, gen. et sp. nov. (Trebouxiophyceae, Chlorophyta)

‘Chlorella’ and ‘Nannochloris’ were traditional genera of minute coccoid green algae with numerous species described in the past century, including isolates used as experimental test organisms. In the last few years, the introduction of DNA-based phylogenetic analyses resulted in a large number of taxonomic revisions. We investigated and reclassified a taxonomically problematic group within the Trebouxiophyceae (comprising ‘Nannochloris eucaryotum’ UTEX 2502, ‘N. eucaryotum’ SAG 55.87 and ‘Chlorella minutissima’ SAG 1.80), distantly related to the recently described Chloroparva isolates (97.5–97.9 % 18S rRNA gene pairwise similarity). Cryopreserved material of SAG 55.87 was selected as holotype for a novel species – Pseudochloris wilhelmii Somogyi, Felföldi & Vörös – whose phylogenetic position confirmed the proposal of a new genus. Pseudochloris wilhelmii had spherical to oval cells with an average diameter of 2.6 × 2.8 µm and a simple ultrastructure characteristic of small green algae. Vegetative cells sometimes contained several lipid droplets occupying a large portion of the cells. The cell wall consisted of an outer trilaminar layer and an inner microfibrillar sheet. Cells divided by autosporulation, forming two or four daughter cells per autosporangium. The pigment composition was typical of green algae, with chlorophylls a and b, and lutein as the dominant carotenoid.

Food allergens are transferred intact across the rat blood-placental barrier in vivo

We investigated the mechanism of transplacental macromolecular transport in rats on the nineteenth day of pregnancy using tracers, transmission electron microscopy and immunohistochemistry. The blood-placental barrier of full-term rat placentas was composed of a trilaminar layer of trophoblast cells that separates the fetal capillaries from the maternal blood spaces: a layer of cytotrophoblasts lining the maternal blood space and a bilayer of syncytiotrophoblast surrounding the fetal capillaries. Horseradish peroxidase, intravenously injected into the maternal circulation, was found in the maternal blood spaces, the interspaces between the cytotrophoblasts and the syncytiotrophoblast I, many pits and small vesicles in the syncytiotrophoblast I, vesicles of the syncytiotrophoblast II, fetal connective tissue and fetal capillaries. Intravenously injected ovalbumin was detected in the maternal blood spaces, a trilaminar layer and the fetal capillaries. Neonatal Fc receptor (FcRn), a receptor for IgG, was localized at the maternal side of the blood-placental barrier. These results show that the structure of the rat blood-placental barrier is quite similar to the human blood-placental barrier, and non-specific macromolecules and food allergens may penetrate through the blood-placental barrier of the full-term placenta from the maternal to fetal circulation mediated by FcRn.

Chloroparva pannonica gen. et sp. nov. (Trebouxiophyceae, Chlorophyta) – a new picoplanktonic green alga from a turbid, shallow soda pan

Somogyi B., Felföldi T., Solymosi K., Makk J., Homonnay Z.G., Horváth G., Turcsi E., Böddi B., Márialigeti K. and Vörös L. 2011. Chloroparva pannonica gen. et sp. nov. (Trebouxiophyceae, Chlorophyta) – a new picoplanktonic green alga from a turbid, shallow soda pan. Phycologia 50: 1–10. DOI: 10.2216/10-08.1We describe Chloroparva pannonica Somogyi, Felföldi & Vörös gen. et sp. nov., a new trebouxiophycean picoplanktonic alga isolated from a turbid, shallow soda pan in Hungary. The cells are spherical to oval, less than 2 µm in diameter, with simple ultrastructure typical to small green algae. Cells divide by autosporulation, forming two daughter cells per autosporangium. Cell wall structure consists of an outer trilaminar layer, an inner microfibrillar layer and an electron-transparent layer covering the plasma membrane. The trilaminar layer of the mother cell wall often persists around the autospores. Typical chlorophyte pigments have been found, including chlorophyll a and b and lutein as the dominant carotenoid. The main fatty acid was oleic acid. The phylogenetic position of the new chlorophyte confirms the proposal of a new genus within the Trebouxiophyceae. Based on its 18S rRNA gene sequence, this isolate is distantly related to Nannochloris eucaryotum UTEX 2502, Chlorella minutissima C-1.1.9 and C. minutissima SAG 1.80 (≤ 97.6% 18S rRNA gene pairwise similarities).

THE FIBRILLAR POLYSACCHARIDES AND THEIR LINKAGE TO ALGAENAN IN THE TRILAMINAR LAYER OF THE CELL WALL OF COELASTRUM SPHAERICUM (CHLOROPHYCEAE)

Methylation and spectroscopical analyses of DMSO‐LiCl‐solubilized fractions of the fibrillar cell wall of Coelastrum sphaericum Näg. established the presence of cellulose and β‐1,4‐linked mannan. A small proportion (2–7%) of (1→2) linkages in β‐mannan that introduced an interruption in the regular ribbon chain conformation was interpreted as a component that modulated the mechanical strength of the cell wall. The trilaminar layer fractions consisted mostly of algaenan and cellulose. Evidence for ether linkages between glucose C‐6 in the β‐1,4‐glucan and algaenan was obtained.

Development of structure-less pollen wall inCeratophyllum demersum L. (Ceratophyllaceae)

Developmental process of structure-less exine is studied in a hydrophilous plant,Ceratophyllum demersum L., with electron microscopy. The plant shows a characteristic feature in tetrad formation. A callose wall is not synthesized and exine initiation does not occur during the tetrad stage. After release of microspores, a trilaminar layer with two electron-dense lines is formed in the surface of each microspore. The trilaminar layer develops to a thin structure-less exine that is considered to consist of only an endexine. The unusual exine would be an adaptive feature for submersed pollination in fresh water.

Partial characterization of the adsorbed protein layer on Dirofilaria immitis (Nematoda) cuticle.

Electron microscopy coupled with ferritin-conjugated indirect immunolabeling was used to locate sites of adsorbed host protein on cuticular surfaces of the adult canine heartworm, Dirofilaria immitis. The epicuticle appeared as a trilaminated structure. At high magnifications, the outermost layer of this structure was resolved into a trilaminar layer, which might correspond to the plasma membrane of animal cells. A ruthenium red-positive layer was external to the epicuticle. Ferritin-antibody conjugates showed evidence of adsorbed dog albumin, dog immunoglobulin class G (IgG), and dog complement fraction 3 (C3) on the surface. Ferritin adsorption to control surfaces was minimal. Possible causes and effects of interfacial host-protein adsorption are discussed in an attempt to bring insight to the hemocompatible nature of the parasitic cuticle.

The tardigrade cuticle. I. Fine structure and the distribution of lipids

Fine structure and lipid distribution are studied in cuticles of five tardigrade species using TEM and SEM. Double osmication using partitioning methods reveals a substantial lipid component in the intracuticle and in irregular granular regions within the procuticle. These results are substantiated by the loss of osmiophily following lipid extraction with chloroform and methanol. Other lipid components are revealed by osmication following unmasking of lipo-protein complexes with thymol. These occur in the outer epicuticle and in the trilaminar layer lying between the epi- and intracuticles. Anhydrous fixation of dehydrated tardigrades (tuns) reveals dense, superficial masses of osmiophilic material, apparently concentrated lumps of the surface mucopolysaccharide (‘flocculent coat’). However, cryo-SEMs of tuns reveal similar dense aggregations which apparently exude from pores (not visible) and are removed by chloroform. These results suggest extruded lipids since the flocculent coat is unaffected by chloroform; likely functions of such lipids are discussed.

CULTURING, ULTRASTRUCTURE AND COLONY FORMATION INPECTODICTYON CUBICUM(CHLOROPHYCEAE, CHLOROCOCCALES)12

ABSTRACTPectodictyon cubicumTaft collected in California develops typical eight‐celled, cuboidal colonies only in alkaline media. Vegetative cell ultrastructure is similar to that in other genera of the Chlorococcales, except for an extensive endoplasmic reticulum system paralleling the plasmalemma (termed a paramural ER). Autosporogenesis proceeds inside the parent cell wall by three mitotic divisions producing eight nuclei in two tiers of four. Cleavage furrows following paths delineated by long ER segments and indistinct microtubules bisect and then radically separate the protoplast into eight pyramidal units. Walls comprised of a thick, presumably cellulose layer and a thinner trilaminar layer (not acetolysis resistant) form as cells become rounded, except where touching. A gelatinous matrix is produced around and between cells with concentration at the three sites of prior cell contact 90 degrees apart. Pulsed production of mucilage in three solid strands forces cells to separate, and the expanding colony becomes a hollow cube with a cell at each corner.

Sporopollenin in the cell walls of Coccomyxa and Myrmecia phycobionts of various lichens: an ultrastructural and chemical investigation

Symbiotic and cultivated Myrmecia phycobionts of Baeomyces rufus and Coccomyxa phycobionts of five different asco- and basidio-lichens were investigated with cytological and chemical methods. The cell wall structure of the free-living type species Coccomyxa dispar was compared with that of the lichen phycobionts.Three different wall layers were observed in all Coccomyxa and Myrmecia cells investigated. An innermost, variably thick layer is amorphous in structure and is built up mainly by Golgi-derived hemicelluloses. An outer wall layer, uniformly thick, appears electron dense in thin sections and exhibits short, probably cellulosic fibrils embedded in an amorphous matrix in freeze-fracture preparations. Beyond these two wall layers is an outermost trilaminar wall layer of uniform thickness in all species investigated. It contains sporopollenin in its electron-transparent, rigid middle part; proteinlike particles are embedded in an amorphous, carbohydrate-containing matrix on its electron-dense inner and outer surfaces. IR spectrophotometry of acetolysis-resistant material yielded data comparable with those of other sporopollenin-containing algal walls, although the Coccomyxa and Myrmecia sporopollenin did not dissolve in chromic acid. The trilaminar layer is not lysed during or after autospore formation. Persistent mother cell walls were detected in all lichen thalli investigated, as well as in the culture medium of isolated phycobionts. Persistent mother cell walls were also found in the gelatinous sheath of Coccomyxa dispar.This type of wall structure affords protection against fungal parasitism and may be a significant factor in the success of some lichens and some other symbiotic systems.

CELL DIVISION AND COLONY FORMATION IN THE GREEN ALGACOELASTRUM(CHLOROCOCCALES)1

ABSTRACTMultinucleate cells ofCoelastrumundergo precisely directed cytokinesis, guided by phycoplast microtubules, to form a number of uninucleate daughter cells which subsequently adhere to form characteristically patterned aggregates. As there is no movement of the daughter cells relative to one another before their adhesion, the disposition of cells in daughter colonies reflects the pattern of cytokinesis of parent cells. Centrioles lie at the poles of the mitotic nuclei which are partially enclosed by a perinuclear envelope of endoplasmic reticulum. The centrioles disappear at the time of cytokinesis of the parental cell and apparently reformde novoonce the daughter cells have acquired a cell wall following their adhesion. The trilaminar layer of cell wall, often termed the pectic layer, does not stain with ruthenium red and resists acetolysis suggesting that it contains sporopollenin rather than pectin.

THE ULTRASTRUCTURE OFSCENEDESMUS(CHLOROPHYCEAE). II. CELL DIVISION AND COLONY FORMATION1

SUMMARYCell division in Scenedesmus is fairly typical of other chlorococcalean genera. The closed spindle has centrioles at polar fenestrae and apparently a series of nuclear divisions precedes cytokinesis. The phycoplast system of cytokinetic microtubules predicts the path of cleavage furrows whose mode of formation is obscure. Before and during cell division, the endoplasmic reticulum invariably accumulates granular material which later, during cytokinesis, appears to he secreted via the golgi bodies. Similar dense granular material then at accumulates outside the forming daughter cells but inside the parental wall, as the latter begins eroding away. By the end of colony formation, the cellulosic parental wall has disappeared, leaving its outer sheath and attached ornamentative features (spines, combs, reticulate or warty layer, etc.) intact as a “ghost.”The spines and combs of new colonies appear to condense out of the extracellular aggregate; their precise mode of formation is obscure. As they form, the daughter cells, having become rearranged within the parental wall, stick to one another apparently at specific sites on their outer surface. A trilaminar (sporopollenin‐containing) layer arises first in each cell at these adhesive sites and immediately afterwards, dense material aggregates between the adjacent layers to give rise to the coenobial adhesive. Plaques of the trilaminar layer later appear over the rest of the cell's surface; they grow and fuse so that eventually each cell is enclosed by one continuous Trilaminar Sheath (TLS). While the plaques are forming, another dense layer materializes around the whole coenobium. Depending on the species, this layer turns into either the warty layer, in which instance it is applied directly on to the surface of the TLS except near the coenobial adhesive, or else it becomes the reticulate layer, in which instance it remains entirely separate from the TLS, soon acquiring the complex system of propping spikelets which suspend it from the coenobial surface.When fully farmed, the daughter coenobium is tightly compressed within the parental TLS, with its spines folded lengthwise along the daughter cells. Release of the colony follows a quite explosive rupturing of the parental TLS, and immediately upon release, the daughter colony flattens out and erects its spines.

Tubular structures associated with intracytoplasmic spirochetes.

When tissues of spirochete-infected brine shrimp (Artemia salina) were examined by electron microscopy, tubular structures were often seen closely associated with intracytoplasmic spirochete profiles. These tubules were never observed in association with spirochetes found in the haemocoeal or other extracellular spaces. Since the trilaminar layer comprising the wall of the tubules was identical in ultrastructure to the outer envelope of the spirochete, these structures were interpreted to be finger-like extensions of the spirochete outer envelope.