Microscopic and ultramicroscopic anatomical characteristics of root nodules in Podocarpus macrophyllus during development

To understand the morphological and structural characteristics of root nodules in Podocarpus macrophyllus and their development, this study prepared P. macrophyllus root nodule samples at the young, mature, and senescent stages. Optical microscopy and transmission electron microscopy (SEM) revealed that new nodules can be formed on roots and senescent nodules; new nodules formed on the roots are nearly spherical and have an internal structure similar to finite nodules; new nodules on senescent nodules are formed by extension and differentiation of the vascular cylinder of the original nodules; and these new nodules are nested at the base of the original nodules, which create growth space for new nodules by dissociating the cortical tissue; clusters of nodules are formed after extensive accumulation, and the growth pattern is similar to that of infinite nodules; the symbiotic bacteria of P. macrophyllus root nodules mainly invade from the epidermal intercellular space of the roots and migrate along the intercellular space of the nodule cortex; infected nodule cortex cells have a well-developed inner membrane system and enlarged and loose nuclei; and unique Frankia vesicles, and rhizobia cysts, and bacteriophages can all develop. Compared with common leguminous and nonleguminous plant nodules, P. macrophyllus root nodules are more complex in morphology, structure and composition. From the perspective of plant system evolution, the rhizobium nodules in leguminous angiosperms and Frankia nodules in nonleguminous angiosperms are most likely two branches derived from the nodules in gymnosperms, such as P. macrophyllus. The conclusions of this study can provide a theoretical basis for the developmental biology of P. macrophyllus root nodules and the evolutionary pattern of plant symbionts.

Differential Diagnostics of Toxic Epidermal Necrolysis (Lyell’s Syndrome) in ICU: Case Reports

Toxic epidermal necrolysis (TEN) is a critical life-threating condition developing as the total detachment of epidermidis and characterized by severe pathological reactions of all body systems. The current article describes two cases of TEN with similar clinical and laboratory signs. In one case the diagnosis of TEN was subsequently refused.The objective: analysis of methods of clinical and differential diagnostics of conditions accompanied with massive epidermidis detachment in ICU patients.Results. The immunomorphological evaluation of skin specimen obtained from the patient with a torpid form of TEN showed linear IgG fixation in the intercellular space of stratum basale, stratum spinosum and stratum granulosum and C3 fixation in the intercellular space of stratum basale.Conclusion. The complex of anamnesis data and pathomorphological evaluation of skin are crucial for the diagnosis and treatment of patients with atypical TEN.

Hemagglutination in gill capillaries of sheepshead, Archosargus probatocephalus (Perciformes: Sparidae), infected by a myxosporidean

During a survey Myxozoa, four specimens of the sheepshead (18 ± 1.5 cm and 59 ± 2.5 g) (Archosargus probatocephalus) were collected in the Ipioquinha river (Maceió/AL). Transmission electron microscopy observations revealed erythrocyte agglutinations in gill capillaries located near spherical cysts containing myxospores of the genus Henneguya. This hemagglutination partially or totally obstructed the gill capillaries. Erythrocytes occurred in close adherence to each other, with a closed intercellular space. A few lysed erythrocytes were observed among agglutinated cells. The reduced lumen of the capillaries was partially filled with amorphous dense homogenous material adhering to the erythrocytes. In addition, heterogeneous masses of irregular lower electron density were observed in the reduced channel of the capillary. The agglutinated erythrocytes appeared dense and homogenous, lacking cytoplasmic organelles. The nuclei had the appearance of normal condensed chromatin masses, generally without visible nucleoli. This occurrence of hemagglutination only in the capillaries located in close proximity to the developing myxozoan cysts suggests that parasite development may be a factor triggering erythrocyte agglutination. This is supported by previous experimental studies that showed a probable correlation between parasitic infections and hemagglutination. Nonetheless, further studies are necessary in order to better understand the physicochemical processes involved in this phenomenon.

Small Extracellular Vesicles and COVID19—Using the “Trojan Horse” to Tackle the Giant

The COVID-19 pandemic is a global challenge, demanding researchers address different approaches in relation to prevention, diagnostics and therapeutics. Amongst the many tactics of tackling these therapeutic challenges, small extracellular vesicles (sEVs) or exosomes are emerging as a new frontier in the field of ameliorating viral infections. Exosomes are part of extracellular vesicles (EVs)—spherical biological structures with a lipid bilayer of a diameter of up to 5000 nm, which are released into the intercellular space by most types of eukaryotic cells, both in physiological and pathological states. EVs share structural similarities to viruses, such as small size, common mechanisms of biogenesis and mechanisms for cell entry. The role of EVs in promoting the viral spread by evading the immune response of the host, which is exhibited by retroviruses, indicates the potential for further investigation and possible manipulation of these processes when tackling the spread and treatment of COVID-19. The following paper introduces the topic of the use of exosomes in the treatment of viral infections, and presents the future prospects for the use of these EVs.

Supposition about absence of contact inhibition of cancer cells

As is known, the superficial charge of most somatic cells is negative. Proceeding from this fact, somatic cells never interact. There is always some type of space (intercellular space) between them. Intercellular contacts are predominantly determined by two main factors: Van der Waals (positive taxis) and electrostatic (negative taxis) forces contributing to the formation of membrane electric potential. Presence of the intercellular space is a structural representation of the balance bet­ween these forces (contact inhibition).

The influence of foliar fertilization of maiden pear trees and soaking the root system of the rootstocks in hydrogel with the addition of Trifender WP preparation on the growth of maiden quince trees in a nursery

The comparison of the influence of foliar fertilization with four preparations on the growth of ‘Conference’ maiden pear trees growing on MA quince rootstock was conducted in a nursery in a three-year period. The evaluation was conducted on the basis of maidens growth parameters and the state of their leaf minerals content as well as on photosynthetic activity of the maiden trees. The preparations used in the experiment affected the improvement of some growth parameters studied, especially the stem diameter and fresh mass of the maidens. Biopuls Original turned out to be the best preparation as it improved significantly three out of five studied growth parameters. A varied impact of the preparations used on the content of micro and macro-elements in leaves was detected. All tested preparations positively influenced the leaves area index of maiden trees except for Blackjak preparation. Photosynthetic intensity of maiden pear trees nourished through leaves was significantly smaller in comparison with the control. Only plants treated with Biopulus Original were characterized by a higher concentration of CO2 and its level in intercellular space. The aim of the second experiment was to check the influence of the application of Trifender WP preparation with hydrogel on the growth of ‘Champion’ maiden quince trees at the stage of planting the rootstocks into a nursery. A better branching of the rootstocks was obtained after the use of the preparation with hydrogel and the hydrogel alone. The trees in these combinations were also characterized by bigger fresh and dry mass of the leaves. The influence of Trifinder WP applied in connection with hydrogel was the best.

Ultrastructure and energy dispersive spectroscopy-based elemental analysis of the fruit exocarps of Musa sinensis L. (Banana) and Musa paradisiaca L. (Plantain) (Musaceae)

Ultrastructural investigation and analysis of the elemental spectra composition of Musa sinensis L. and Musa paradisiaca L. exocarp (peels) was carried out using the Scanning Electron Microscopy (SEM) and Energy Dispersive X-Ray (EDX) respectively. Microstructures such as interlocked, polyhedral epidermal cells, ellipsoid-shaped stomata, guard cells, intercellular space, anticlinal-patterned walls and subsidiary cells were observed, with direct and indirect implications in the deposition of important primary and secondary metabolites, thus connoting some medicinal significance. Furthermore, the energy dispersive x-ray spectra revealed the presence of some important elements such as potassium (K), iron (Fe), carbon (C), oxygen (O), silicon (Si) and gold (Au), with high to relatively high carbon and oxygen peaks consistently observed in Musa sinensis and Musa paradisiaca. In the same vein, the relative similarity observed in the constituents of quite a number of the elemental spectra (carbon, oxygen, silicon, gold) in M. sinensis and M. paradisiaca peels, also reflects species relatedness between M. sinensis and M. paradisiaca.

Comprehensive histological imaging of native microbiota in human glioma

Mounting evidence suggests that distinct microbial communities reside in tumors and play important roles in tumor physiology. Recently, Nejman et al. profiled the composition and localization of intratumoral bacteria using 16S DNA sequencing and histological visualization methods across seven tumor types, including human glioblastoma. However, considering potential contamination in their sample origins and processing, the results based on traditional histological methods need to be validated. Here, we propose a three-dimensional (3D) intratumoral microbiota visualization and quantification protocol to observe microbiota in intact tumor tissues on the premise of avoiding possible contamination in the surface of tissues, based on tissue clearing, immunofluorescent labeling, microscopy imaging, and image processing. For the first time, we have achieved 3D quantitative imaging of bacterial LPS fluorescent signals deep in gliomas in a contamination-free manner, which was founded mostly localized near nuclear membranes or in the intercellular space. Through an automated statistical algorithm, reliable signals can be distinguished for further analysis of their sizes, distribution, and fluorescence intensities. Combining two-dimensional images from multiple thin-section histological methods, including immunochemistry and fluorescence in situ hybridization, we provide a comprehensive histological investigation of the morphology and distribution of these signals on human glioma samples. We expect that this multi-evidence chain will provide supporting proof for the presence of intratumoral bacteria in human glioma and that the integrated pipeline can be applied to investigate the native bacteria within diverse tumors and contribute to the interpretation of their direct roles in the tumor microenvironment.

Co-culturing experiments reveal the uptake of myo-inositol phosphate synthase (EC 5.5.1.4) in an inositol auxotroph of Saccharomyces cerevisiae

Background Myo-Inositol Phosphate Synthase (MIP) catalyzes the conversion of glucose 6- phosphate into inositol phosphate, an essential nutrient and cell signaling molecule. Data obtained, first in bovine brain and later in plants, established MIP expression in organelles and in extracellular environments. A physiological role for secreted MIP has remained elusive since its first detection in intercellular space. To provide further insight into the role of MIP in intercellular milieus, we tested the hypothesis that MIP may function as a growth factor, synthesizing inositol phosphate in intercellular locations requiring, but lacking ability to produce or transport adequate quantities of the cell–cell communicator. This idea was experimentally challenged, utilizing a Saccharomyces cerevisiae inositol auxotroph with no MIP enzyme, permeable membranes with a 0.4 µm pore size, and cellular supernatants as external sources of inositol isolated from S. cerevisiae cells containing either wild-type enzyme (Wt-MIP), no MIP enzyme, auxotroph (Aux), or a green fluorescent protein (GFP) tagged reporter enzyme (MIP- GFP) in co- culturing experiments. Results Resulting cell densities and microscopic studies with corroborating biochemical and molecular analyses, documented sustained growth of Aux cells in cellular supernatant, concomitant with the uptakeof MIP, detected as MIP-GFP reporter enzyme. These findings revealed previously unknown functions, suggesting that the enzyme can: (1) move into and out of intercellular space, (2) traverse cell walls, and (3) act as a growth factor to promote cellular proliferation of an inositol requiring cell. Conclusions Co-culturing experiments, designed to test a probable function for MIP secreted in extracellular vesicles, uncovered previously unknown functions for the enzyme and advanced current knowledge concerning spatial control of inositol phosphate biosynthesis. Most importantly, resulting data identified an extracellular vesicle (a non-viral vector) that is capable of synthesizing and transporting inositol phosphate, a biological activity that can be used to enhance specificity of current inositol phosphate therapeutics.

Angulin-1 seals tricellular contacts independently of tricellulin and claudins

Tricellular tight junctions (tTJs) are specialized tight junctions (TJs) that seal the intercellular space at tricellular contacts (TCs), where the vertices of three epithelial cells meet. Tricellulin and angulin family membrane proteins are known constituents of tTJs, but the molecular mechanism of tTJ formation remains elusive. Here, we investigated the roles of angulin-1 and tricellulin in tTJ formation in MDCK II cells by genome editing. Angulin-1–deficient cells lost the plasma membrane contact at TCs with impaired epithelial barrier function. The C terminus of angulin-1 bound to the TJ scaffold protein ZO-1, and disruption of their interaction influenced the localization of claudins at TCs, but not the tricellular sealing. Strikingly, the plasma membrane contact at TCs was formed in tricellulin- or claudin-deficient cells. These findings demonstrate that angulin-1 is responsible for the plasma membrane seal at TCs independently of tricellulin and claudins.