Capture of Essential Trace Elements and Phosphate Accumulation as a Basis for the Antimicrobial Activity of a New Ultramicrobacterium—Microbacterium lacticum Str. F2E

Microbial interactions play an important role in natural habitat. The long-term coevolution of various species leads to the adaptation of certain types of microorganisms as well as to the formation of a wide variety of interactions such as competitive, antagonistic, pathogenic and parasitic relationships. The aim of this work is a comprehensive study of a new ultramicrobacterium Microbacterium lacticum str. F2E, isolated from perennial oil sludge, which is characterized by high antimicrobial activity and a unique ultrastructural organization of the cell envelope, which includes globular surface ultrastructures with a high negative charge. A previously undescribed mechanism for the antagonistic action of the F2E strain against the prey bacterium is proposed. This mechanism is based on the ability to preferentially capture essential microelements, in which charge interactions and the property of phosphate accumulation may play a significant role. The revealed type of intermicrobial interaction can probably be attributed to the non-contact type antagonistic action in the absence of any diffuse factor secreted by the antagonistic bacteria.

Dynamics of pathomorphological changes of ultrastructural organization of intervertebral disc at different terms of experimental opioid influence and with its cancellation

Background. Patients with degenerative diseases of the spine - "difficult patients". Often, exhausted by long-term pain, they have a dependence, and sometimes tolerance to various analgesics, which greatly reduces the effectiveness of routinely used in the hospital anesthesia. Objective. The aim of our work was to study the features of pathomorphological manifestations of the structural components of the intervertebral disc at different terms of opioid influence and at the difference at the ultrastructural level in the experiment. Methods. The material of the study were sexually mature, white, nonlinear rats - males in the amount of 90 hundred animals, weighing 92 - 103 g, aged 4.5 months. Animals were injected with Nalbuphine at home, once daily for one day (10-11 am) for 42 days. The initial dose of Nalbuphine was 8 mg / kg during the first week, 15 mg / kg during the second week; 20 mg / kg during the third week; 25 mg / kg during the fourth week; 30 mg / kg during the fifth week and 35 mg / kg during the sixth week of the experimental opioid effect. Thus created the conditions for chronic opioid exposure. Intervertebral discs of rats were used as material for ultrastructural study. Results and conclusion. As a result of our study, we found that at the end of 21 days we found the progression of alternative changes in the cellular elements of the gelatinous nucleus, characterized by the development of necrotic changes in notochondral cells, as well as chondroptosis of chondrocytes. Preserved notochondral cells were rarely visualized. In some places, there were notochondral cells in which the nucleus disintegrated into separate fragments filled with heterochromatin, and the remains of organelle membranes were localized in the enlightened cytoplasm. Pronounced destructive changes were found in chondrocytes. After 28 days, the changes progressed, this was manifested by the fact that in the pulpal nucleus there were extensive cell-free zones filled with a significant amount of granular intensely osmophilic mass. Notochondral cells and most chondrocytes underwent necrotic changes. After 35 days at the ultrastructural level revealed pronounced changes in the structural elements of the gelatinous nucleus and fibrous ring. Extensive cell-free zones were localized in the gelatinous nucleus, with a somewhat compacted matrix in which an intensely osmophilic fine-grained deep mass accumulated. With the abolition of opioid exposure at the end of 56 days, we found pronounced changes in notochondral cells and in the vast majority of chondrocytes. The matrix of the gelatinous nucleus was compacted, it showed thickened collagen fibrils. Most of the cellular elements of the gelatinous nucleus were at different stages of necrosis, and some chondrocytes - chondroptosis. Vacuoles filled with enlightened contents also appeared in the cytoplasm. The nucleus was compacted, condensation of chromatin was observed. In such areas, the fibrils of collagen fibers were loose, stratified, disintegrated and lysed.

Ultrastructural characteristics of the rats laryngeal mucosa and cartilage on the 7 and 14 days of the experimental opioid effect

Background and objective. Our main task was to study the ultrastructural organization of the laryngeal mucosa and cartilage on the seventh and fourteenth day of opioid exposure. Methods. The material for the study were mature, outbred male rats in the number of 32 animals, weighing 80g, aged 4.5 months. Animals were injected intramuscularly with Nalbuphine once a day at the same time (10-11 hours in the morning) for 14 days. The initial dose of Nalbuphine was 8 mg / kg during the first week, 15 mg / kg during the second week of the experimental study. Thus, we created the conditions for chronic opioid exposure. Animals were divided into 3 experimental groups: 1 – control group; 2 - animals that received the drug for 7 days; 3 - animals that received the drug for 14 days). All animals were kept in a vivarium. Animal care, labeling and all other manipulations were carried out taking into account the issues of bioethical norms. Before collecting necropsy material, the animal was removed from the experiment with diethyl ether. The the larynx mucosa and rats cartilage were used as the material for ultrastructural examination. Ultrastructural capsule was prepared according to conventional methods. Results. As a result of experimental opioid exposure at the end of 7 days we found alternative changes in the epithelial cells of different parts of the larynx, dyscirculatory changes in blood vessels of lamina propria and submucosa, as well as the destruction of chondrocytes of hyaline and elastic cartilages. The hemocapillaries of lamina propria and submucosa, especially in the ventricles of the larynx and in the subchondral region, were dilated, overflowing with erythrocytes. In the laryngeal mucosa and submucosal base of the laryngeal ventricles, in addition to the overflow of hemocapillaries with erythrocytes, a moderate accumulation of perivascular transudate was noted. At the end of the 14th day of the experimental opioid effect, a pronounced hemocapillaries injury was found, which was accompanied by an increase in the permeability of the vascular wall. In addition to blood plasma, erythrocytes were visualized in the enlarged lumens of hemocapillaries. The development of degenerative changes of endothelial cells, which were accompanied by inhomogeneous dilation of the tubules of the smooth and granular endoplasmic reticulum, was noted. The main substance of the connective tissue of the mucous membrane and submucosal base, especially around the vessels was impregnated with transudate.

Morphological and Ultrastructural Characterization of Antennal Sensilla and the Detection of Floral Scent Volatiles in Eupeodes corollae (Diptera: Syrphidae)

The olfactory sensing system of the syrphid fly Eupeodes corollae is essential in pollination and prey localization, but little is known about the ultrastructural organization of their olfactory organs. In this study, the morphology, distribution, and ultrastructural organization of antennal sensilla of E. corollae in both sexes were observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Neuronal responses of a subtype of sensilla basiconica to floral scent compounds were recorded by single sensillum recording (SSR). Ten morphological types, including Böhm bristles, sensilla chaetica, microtrichiae, sensilla trichodea, sensilla basiconica, sensilla clavate, sensilla coeloconica, sensilla styloconica, sensilla placodea, and sensory pit, were identified. Except for Böhm bristles and sensilla chaetica, which were distributed on the scape and pedicel of E. corollae antennae, innervated sensilla were densely distributed on the flagellum, a vital sensory organ. Further, observing ultrastructural organization showed that the sensilla trichodea, basiconica, and clavate are single-walled with multiple nanoscale pores perforating the cuticle. Sensilla coeloconica are double-walled and have no wall pores, but instead, have longitudinal grooves along with the pegs. Sensilla chaetica, Böhm bristles, and microtrichiae did not have wall pores on the cuticle or sensory cells at the base. The SSR results indicated that neuron B housed in the subtype of sensilla basiconica I (SBI) mainly responded to methyl eugenol and other aromatic compounds. Overall, our results provide valuable information to understand the morphology and ultrastructure of antennal sensilla from E. corollae. These findings are beneficial for the studies of the neuronal function map of olfactory sensilla and for determining evolutionary relationships in Diptera.

Glycyrrhiza uralensis Nodules: Histological and Ultrastructural Organization and Tubulin Cytoskeleton Dynamics

Chinese liquorice (Glycyrrhiza uralensis Fisch. ex DC.) is widely used in the food industry and as a medicine. Like other legumes, G. uralensis forms symbiotic nodules. However, the structural organization of G. uralensis nodules is poorly understood. In this study, we analyzed the histological and ultrastructural organization and dynamics of the tubulin cytoskeleton in various cells from different histological zones of indeterminate nodules formed by two strains of Mesorhizobium sp. The unusual walls of infection threads and formation of multiple symbiosomes with several swollen bacteroids were observed. A large amount of poly-β-hydroxybutyrate accumulated in the bacteroids, while the vacuoles of meristematic and uninfected cells contained drop-shaped osmiophilic inclusions. Immunolocalization of the tubulin cytoskeleton and quantitative analysis of cytoskeletal elements revealed patterns of cortical microtubules in meristematic, infected and uninfected cells, and of endoplasmic microtubules associated with infection structures, typical of indeterminate nodules. The intermediate pattern of endoplasmic microtubules in infected cells was correlated with disordered arrangement of symbiosomes. Thus, analysis of the structural organization of G. uralensis nodules revealed some ancestral features more characteristic of determinate nodules, demonstrating the evolutionary closeness of G. uralensis nodulation to more ancient members of the legume family.

ULTRASTRUCTURAL ORGANIZATION OF NEURONS OF THE LATERAL PREOPTIC NUCLEUS OF THE HYPOTHALAMUS OF OLD RATS UNDER VARIOUS LIGHT CONDITIONS

Purpose – to study the changes in the ultrastructure of neurons of the lateral preopticnucleus (LPON) of the hypothalamus of old rats under various light conditions.Material and methods. The experiments were carried out on 36 old white male rats.The material was fixed in a 2.5% solution of glutaraldehyde, prepared on the basisof phosphate buffer with a pH of 7.2–7.4. Then, postfixation was performed in a 1%solution of osmium tetraoxide and dehydrated in propylene oxide, after which it waspoured into a mixture of epoxy resins. Ultrathin sections made on an ultramicrotomeLKB-3 were contrasted with uranium acetate and lead citrate according to the Reynoldsmethod and studied under electron microscope TEM - 125 K.Results. Studies of LPON neurons under the standard light mode revealed nuclei withuneven contours. The nucleoli are quite large. The neuroplasm contains well-developedtubules of the rough endoplasmic reticulum (ER) and small cisternae of the Golgi complex(GC). Mitochondria are rounded, small, with moderately pronounced cristae. Underconditions of round-the-clock darkness, we have found that the cell nuclei are rounded,less often determined by the nucleoli. In the neuroplasm there are locally dilated tubulesof the ER and cisternae of the GC, mitochondria with enlightened matrix and fragmentedcristae. Under conditions of round-the-clock illumination, the nuclei of the rounded formwith uneven contours of a nuclear membrane forming deep intussusception are revealed.Nucleoli were rarely identified. In the hyaloplasm, locally dilated tubules of the ERare identified. Mitochondria are small in size with an enlightened matrix and reducedcristae.Conclusions. The obtained results of submicroscopic examination of LPON neuronsof the hypothalamus of old rats revealed their relatively increased functional activityin the dark period. Under conditions of round-the-clock lighting, more pronouncedhypertrophic and initial destructive changes of the nuclei and organelles of the neuronsof the LPON of the hypothalamic were revealed, compared with the animals that wereunder the conditions of round-the-clock darkness. This is confirmed by the change in theultrastructure of nerve cells at 2 am the appearance of "dark" cells.

The influence of melatonin on stress-induced ultramicroscopic changes of the neurons of the supraoptic nuclei of the rat hypothalamus

The aim: to study the effect of melatonin on the ultrastructural state of the supraoptic nuclei of the hypothalamus of rats under immobilization stress.Materials and methods. The experiments were performed on non-linear male white rats weighing 200-220 g. The animals were divided into 3 study series, in each of which the biomaterial was collected at 2 p.m. and at 2 a.m. using electron microscopic method. Long immobilization stress was simulated by keeping rats in special plastic penal cages for 6 hours daily for 7 consecutive days. Melatonin (Sigma, USA, 99.5% purification degree) at a dose of 0.5 mg/kg, in 1.0 ml of solvent (0.9% ethanol solution on physiologic saline) was injected daily, intraperitoneally.Results. When the animals were kept under the standard light regime, the ultrastructural organization of the hypothalamic nuclei at 2 p.m. indicated their low functional activity in comparison with the studies carried out at 2 a.m. Prolonged exposure of rats to immobilization stress was reflected in a significant rearrangement of the ultrastructural organization of supraoptic nuclei of the hypothalamus. The established changes can be considered as a manifestation of neurosecretory activity suppression, a decrease in neurosecretase production by hypothalamic neurons. Melatonin injections against the background of immobilization stress resulted in relative normalization of ultrastructural state of neurons of supraoptic nuclei of the hypothalamus of animals. In particular, studies at 2 a.m. revealed light neurosecretory cells containing a large nucleus, it was pyknotically altered. Karyolema invaginations, euchromatin dominance in the nucleus were observed. Heterogeneous changes were observed on the part of mitochondria. Enlarged tubules of granular endoplasmic reticulum were seen. At the same time, a small number of ribosomes and few hormonal granules were noticeable in neuroplasm. The mentioned picture of neurosecretory cells reflects a relative improvement in their electron microscopic state, which is evidenced by the appearance of neurosecretory granules. However, the ultrastructure of other organelles of the studied neurons indicates a depleted state caused by prolonged immobilization.Conclusions. 1. In animals under standard photoperiod conditions, the structural organization of supraoptic neurons of the hypothalamic nuclei during the nighttime of the experiment reflects the intensity of intracellular synthesizing processes (at 2 a.m.). A decrease in the activity of the structures under study is noted during the daytime. 2. Under immobilization stress, the ultrastructural organization of the above neurons indicates a pronounced disturbance of reactive nature with the signs of decreased functional ability of the structures and the phenomena of edema and destruction during the period of observation. 3. Melatonin injections against the background of immobilization stress led to a relative improvement in the ultrastructural state of the animals’ hypothalamic nuclei neurons, which is evidenced by the appearance of neurosecretory granules. However, the ultrastructure of other organelles of the studied neurons indicated a depleted state caused by prolonged immobilization.

Dynamics of changes in the ultrastructural characteristics of the mucosa and cartilage of the larynx of rats at the end of 35 and 42 days of experimental opioid exposure and after 56 days with opioid withdrawal

In our work, we studied the ultrastructural organization of rat laryngeal mucosa and cartilage at the end of 35 and 42 days of experimental opioid exposure and at the end of 56 days with opioid withdrawal. As a result of our study at the end of the 35th day at the ultrastructural level revealed hypersecretion of goblet cells, mucus contained impurities of lymphocytes, single neutrophils and erythrocytes. In the enlarged lumens of the hemocapillaries of the lamina propria of the mucous membrane and submucosal base of different parts of the larynx, the adhesion of erythrocytes was noted. At the end of 42 days in rats, the changes were characterized by moderate damage to cytoplasmic organelles in epitheliocytes. Alternative changes developed in the chondrocytes of elastic and hyaline cartilages. Marked by an increase in the number of active fibroblasts, next to which were numerous fibrils of collagen fibers. The main substance of connective tissue, near dilated vessels, was impregnated with transudate, which was accompanied by the development of perivasal edema. Glycogen grains and vacuoles filled with neutral fats were visualized in the cytoplasm of chondrocytes.At the end of 56 days in rats with two-week withdrawal of the opioid analgesic, we found the development of alternative processes in the epitheliocytes of different parts of the larynx, as well as in chondrocytes, especially in elastic cartilage. Dyscirculatory processes in vessels of own plate of a mucous membrane and a submucous basis of various departments of a larynx were registered. Necrotic changes developed in the columnar epitheliocytes of the submucosal mucosa. Mitochondria swelled, their matrix brightened, cristae collapsed. The results of the article correspond to the research plan of Danylo Halytskyi Lviv National Medical University and are part of the research topic of the Department of Normal Anatomy "Morphofunctional features of organs in pre - and postnatal periods of ontogenesis, under the influence of opioids, food supplements, reconstructive surgery and obesity" 0120U002129) during 2020 - 2024.