Gastroesophageal tube of the Iguana iguana (Iguanidae): histological description, histochemical and immunohistochemical analysis of 5-HT and SS cells

The work aims were to describe the histological and histochemical structure of the gastroesophageal tube of Iguana iguana and verify the occurrence and distribution of immunoreactive serotonin (5-HT) and somatostatin (SS) cells. Fragments of the gastrointestinal tract (GIT) of five iguanas were which underwent standard histological and immunohistochemistry technique. Immunoreactive cells for 5-HT and SS were quantified using the STEPanizer. The oesophagus has ciliated columnar pseudostratified epithelium with staining Alcian blue (AB) + and goblet cells highly reactive to periodic acid Schiff (PAS). In the cervical oesophagus, the numerical density of 5-HT cells per unit area (QA [5-HT cells]/µm2) was 4.6x10-2 ± 2.0 and celomatic oesophagus presented QA = 4.0x10-2 ± 1.0. The epithelium of the stomach is simple columnar, PAS and AB +. The cranial and middle regions of the stomach presented (QA [5-HT cells]/µm2) = 6.18x10-2 ± 3.2 and the caudal region, QA = 0.6x10-2 ± 0.2. The SS cells were only observed in the caudal stomach, with numerical density (QA [SS cells]/µm2) = 1.4x10-2 ± 0.9 In I. iguana, variation was observed in terms of the distribution of mucus secretions and the pattern of occurrence of serotonin and somatostatin-secreting enteroendocrine cells in the TGI, which possibly will result in an interspecific adaptive response.

Location of eosinophils in the airway wall is critical for specific features of airway hyperresponsiveness and T2 inflammation in asthma

Eosinophils are implicated as effector cells in asthma but the functional implications of the precise location of eosinophils in the airway wall is poorly understood. We aimed to quantify eosinophils in the different compartments of the airway wall and associate these findings with clinical features of asthma and markers of airway inflammation.In this cross-sectional study, we utilised design-based stereology to accurately partition the numerical density of eosinophils in both the epithelial compartment and the subepithelial space (airway wall area below the basal lamina including the submucosa) in individuals with and without asthma and related these findings to airway hyperresponsiveness (AHR) and features of airway inflammation.Intraepithelial eosinophils were linked to the presence of asthma and endogenous AHR, the type of AHR that is most specific for asthma. In contrast, both intraepithelial and subepithelial eosinophils were associated with type-2 (T2) inflammation, with the strongest association between IL5 expression and intraepithelial eosinophils. Eosinophil infiltration of the airway wall was linked to a specific mast cell phenotype that has been described in asthma. We found that IL-33 and IL-5 additively increased cysteinyl leukotriene (CysLT) production by eosinophils and that the CysLT LTC4 along with IL-33 increased IL13 expression in mast cells and altered their protease profile.We conclude that intraepithelial eosinophils are associated with endogenous AHR and T2 inflammation and may interact with intraepithelial mast cells via CysLTs to regulate airway inflammation.

Extended Prophylactic Effect of N-tert-Butyl-α-phenylnitron against Oxidative/Nitrosative Damage Caused by the DNA-Hypomethylating Drug 5-Azacytidine in the Rat Placenta

Antioxidant N–tert–Butyl–α–phenylnitron (PBN) partly protected embryos from the negative effects of a DNA demethylating drug 5-azacytidine during pregnancy. Our aim was to investigate PBN’s impact on the placenta. Fischer rat dams were treated on gestation days (GD) 12 and 13 by PBN (40 mg/kg), followed by 5azaC (5 mg/kg) after one hour. Global methylation was assessed by pyrosequencing. Numerical density was calculated from immunohistochemical expression in single cells for proliferating (PCNA), oxidative (oxoguanosine) and nitrosative (nitrotyrosine) activity. Results were compared with the PBN-treated and control rats. PBN-pretreatment significantly increased placental weight at GD15 and GD20, diminished by 5azaC, and diminished apoptosis in GD 20 placentas caused by 5azaC. Oxoguanosine expression in placentas of 5azaC-treated dams was especially high in the placental labyrinth on GD 15, while PBN-pretreatment lowered its expression on GD 15 and GD 20 in both the labyrinth and basal layer. 5azaC enhanced nitrotyrosine level in the labyrinth of both gestational stages, while PBN-pretreatment lowered it. We conclude that PBN exerted its prophylactic activity against DNA hypomethylating agent 5azaC in the placenta through free radical scavenging, especially in the labyrinthine part of the placenta until the last day of pregnancy.

Comparative Immunohistochemical Characteristics of Thalamic Glioarchitectonics of Young and Senile Persons

The aim of the investigation was to establish morphological differences between the human thalamus in young and senile age by using an immunohistochemical marker – glial fibrillary acidic protein (GFAP).Material and methods. The results of the sectional study of both thalami of 94 deceased of both sexes were analyzed. Depending on their age (young and senile), they were divided into two groups. The deceased had no history of diseases and injuries of the central and peripheral nervous system organs as well as alcohol and/or drug addiction, no macroscopic signs of brain tissue pathology were detected when material was taken for microscopic examination. Morphological characterization of thalamic tissue in both hemispheres of the large brain using hematoxylin and eosin staining was given. Immunohistochemical study of the samples used antibodies to GFAP.Results. Histological examination of the thalamus in both young and senile age revealed groups of irregularly arranged neuronal bodies with granular cytoplasm and swollen ectopic nuclei. When the immunohistochemical reaction was performed, the product of the reaction was distributed in the bodies and outgrowths of astrocytes. In young age, single bodies of fibrous astrocytes with a moderate number of poorly visualized outgrowths were found. At senile age, in addition to a statistically significant increase in the numerical density of fibrous astrocyte bodies (p<0.01), there is a clear increase in the number of their outgrowths.Conclusion. The results obtained provide a detailed insight into the morphological characteristics of the thalamic tissue of men and women at young and senile age. The use of antibodies to GFAP is a sensitive marker of age-related changes in thalamic cytoarchitectonics. The increase in the numerical density of astrocytes as well as the outgrowth of their processes allows a more precise understanding of age-related involution of nervous tissue, which will allow to use these data in future prospective basic research.

Morphofunctional Changes in Oral Mucosa Vessels when Healing a Wound Defect Using a Polymer Membrane

This works aims to study morphofunctional changes in the vessels of the oral mucosa during regeneration of a wound defect with and without a polymer membrane.An experiment was carried out on 35 white Wistar rats divided into three groups: control, experimental 1 and experimental 2. To form a wound defect, a flap of the oral mucosa was excised, which was covered by a polymeric piezoelectric membrane in the rats of group 2. Histological examination was carried out on the 3rd, 7th and 12th days: the control material was taken, histological preparations were made according to the standard method. In the lesion focus and surrounding tissues, specific areas and numerical densities of arterioles, venules and capillaries were determined; the pericapillary diffusion index, Kernogan index and arterio-venular ratio were calculated.On the 3rd day, all indicators in all experimental groups did not significantly differ from each other, but had significant differences from the control group. On the 7th day of the study, in the 1st group, the numerical density of open arterioles and venules corresponded to the control group. In group 2, the numerical density of capillaries and altered venules, as well as the index of pericapillary diffusion, significantly differed from the control. On the 12th day of the study, the numerical density of open venules reached control values in the uncoated group. In the 2nd group, all indicators corresponded to the control values.Protection of the wound defect from microbial contamination and re-traumatization, the presence of piezoelectric properties of the membrane under study contributed to a more effective restoration of vessels. This confirms the efficacy of the membrane under study when used as a wound covering.

EVIDENCE OF APOPTOSIS IN PARVOCELLULAR NUCLEI OF HYPOTHALAMUS IN DIABETES MELLITUS

Diabetes mellitus (DM) causes great socio-economic damage, which is determined by medical expenses and expenditure on social security to patients due to invalidity and loss of labour capacity. Researchers are studying the role of hypothalamic neuropeptides and their involvement in the regulation of pancreatic islet function. In view of the above, the aim of our study was to establish the features of morphofunctional changes in the arcuate nucleus (AN) and ventromedial nucleus (VN) of the hypothalamus in streptozotocin-induced diabetes mellitus (SIDM). Histological, immunohistochemical, electron-microscopic, biochemical and statistical research methods were used. Polymorphic changes were noted in AN and VN at early stages of development of SIDM (on the 14th day). In AN, the area of neurons and their nuclei became larger, the numerical density of dark functionally more active neurons increased, and dinuclear light neuroendocrine cells (NC) appeared. In light and dark NCs of AN, there was a significant increase in the bulk density of neurosecretory granules – by 2-4 times compared with the control, in VN – by 1.2-2 times. Such morphofunctional changes in parvocellular nuclei of the hypothalamus and the increase in the bulk density of neurosecretory granules in their NCs indicate boosted synthesis of neurohormones which directly affect the adenohypophysis and improving functional activity of NCs in AN and VN. On the 70th day of SIDM in AN and VN of the hypothalamus, there was a decrease in the numerical density of neurons due to light NC and increase in the numerical density of vacuolated, dark pycnomorphic and apoptotic neurons. The apoptotic index in the studied nuclei of the hypothalamus increased by 2-4 times compared with the control. The area of the profile field of NC increased and the area of nuclei decreased, which led to the reduced nuclear-cytoplasmic index and indicated a decrease in their functional activity and was confirmed by a decrease in the bulk density of neurosecretory granules in NC by 1.9-2.1 times in AN and by 2.7-4.7 times in VN. At the ultrastructural level, pronounced destructive processes such as vacuolar dystrophy, development of satelliteosis and neuronophagia were observed in light NCs. Thus, prolonged hyperglycemia in SIDM in parvocellular nuclei of the hypothalamus causes neuronal death to a lesser extent due to apoptosis, and to a greater extentdue due to hydropic dystrophy and colliquative necrosis, especially in the long term of the experiment (on the 70th day), and leads to the development of diabetic neuroendocrinopathy.

Effect of Feeding With Vitamins, Sugars and Pollen on The Biology of Honey Bee Apis Mellifera L. (Hymenoptera : Apidae) During The Autumn Season and The Use of Various Wintering Methods

The research included a study of nutrition with vitamins, sugars, pollen and some dispersal methods in from 5/7/2020 to 5/15/2021 to evaluate the nutrients and their effect on the open and closed brood space, honey area, pollen, eggs, the increase in cell weight, the quantity of honey produced as well as the number of packages of honey bee (Apis mellifera L) colonies. The results showed that feeding with vitamins, sugars and pollen has an important role in preparing the colonies before winter, as they passed it with strong colonies compare with the comparison treatment (without feeding) and with the highest numerical density in the nylon packing boxes treatment compared to the comparison treatment during the tenth month readings. The treatment of cork boxes in the fed colonies was distinguished in the production of immature honey compared to the control treatment. The results also showed the superiority of the colonies fed during the months of November and December 2020 with the same materials over the comparison treatment in bee density, open honey, sealed honey, pollen, eggs, larvae and sealed brood) compared to the control treatment. The fed and treated colonies passed some winterization requirements in good condition and gave the highest cell weights compared to the control treatment in mud boxes, sandwich boxes, wall coverings, cork boxes, and nylon packing. As for the production of sorted honey, the fed and dispersed colonies outperformed the fed and scattered colonies with treatments compared to the comparison treatment, and in the production of parcels, the comparison treatment did not produce any parcels, while the fed and dispersed colonies produced parcels.

Formation of ice particles through nucleation in the mesosphere

Observations of polar mesospheric clouds have revealed the presence of solid ice particles in the upper mesosphere at high latitudes; however, their formation mechanism remains uncertain. In this study, we investigated the formation process of ice particles through nucleation from small amounts of water vapor at low temperatures. Previous studies that used classical nucleation theory have shown that amorphous solid water particles can nucleate homogeneously at conditions that are present in the mesosphere. However, the rate predictions for water in classical nucleation theory disagree with experimental measurements by several orders of magnitude. We adopted a semi-phenomenological model for the nucleation process, which corrects the evaluation of the molecular cluster formation energy using the second virial coefficient, which agrees with both experiments and molecular dynamics simulations. To calculate the nucleation process, we applied atmospheric conditions for the temperature, pressure, numerical density of dust grains, and cooling rate. The results indicate that homogeneous water nucleation is extremely unlikely to occur in the mesosphere, while heterogeneous nucleation occurs effectively. Dust grains generated by meteor ablation can serve as nuclei for heterogeneous nucleation. We also showed that the ice can form directly in a crystalline state, rather than an amorphous state.

Management effectiveness suggests a role in structuring herbivorous fish communities in Sinai marine protected areas, Gulf of Aqaba

Herbivorous reef fishes are critically important for maintaining the health and resilience of coral reefs. In the Egyptian Gulf of Aqaba (GoA), many of these herbivores are important fishery targets and little is known about their population size structure and biomass patterns. Here, we conduct a large-scale (~250 km of coastline) assessment of the status of herbivorous fish populations along a fishing pressure gradient at 30 sites and eight regions in the GoA. These regions are subjected to three levels of fishing and protection, ranging from almost no fishing (No take, NT), and moderately fished (via Gear restriction, GR) to heavily fished (Open access, OA). We found that the NT fishery reserve was the most effective to maintain herbivorous fish size, biomass, and richness across all functional groups, though numerical density was not. Total herbivore biomass was 4.3 and 2.8 times higher on NT reefs and GR reefs, respectively than on OA reefs. Among GoA regions, only Ras Mohammed and Sharm El-Sheikh (unfished), and Nabq (fished) met the global mean herbivore biomass target of ~30 kg/500 m2. Our work also highlights three important results regarding the impacts of fishing and fisheries management on herbivorous fish populations: (i) size structure was heavily skewed toward smaller individuals, with fishes less than (20 cm) accounting for 81.1% of the population in heavily fished OA reefs vs. 52.8% at unfished NT reefs, (ii) biomass of larger herbivore individuals (>35 cm) accounting for less than 1% of the total biomass in OA reefs vs. 37% at NT reefs, and (iii) large-bodied target species, Cetoscarus bicolor, Naso unicorn, and Kyphosus spp., accounting for 15.9% of the total biomass at NT reefs on average, while they were virtually absent from OA reefs. Collectively, these findings suggest that many principal fisheries species in the central northern regions of the GoA have been overexploited, which in turn can lead to reef degradation. Therefore, there is an urgent need to develop a participatory management approach and enforce restrictions on destructive fishing gear in order to promote recovery of herbivore biomass.

Age-Dependent Histomorphometrical Values of the Sciatic Nerve Regeneration in Rats after Cutting and Microsurgical Suturing

The effect of ageing on the morphofunctional features of nerves and the process of their posttraumatic regeneration has been studied in details. However, it is not known, whether there are differences of the neuroregeneration potential in the young, adult and mature experimental animals.The aim of the study was to evaluate histomorphometrical parameters of the rat sciatic nerve regeneration after cutting and microsurgical suturing depending on their age.Materials and Methods. The study included 15 white laboratory Wistar rats aged 5–6 (young), 8–10 (adult) and 12 months (mature). The sciatic nerve was transected at the level of the middle third of the thigh with microsurgical scissors and sutured with six epi-perineural stitches in the animals. In 4 months the animals were euthanized. Sections of sciatic nerves distal to the levels of sutures were put into araldite, semi-thin slices (0.5–1.0 mkm) were obtained for histomorphometric analysis. Thirteen intact animals were selected as control. Statistical processing was performed using nonparametric methods.Results. The numerical density of endoneural vessels in nerves of operated rats was higher than that in the intact ones, but in mature animals it was significantly lower than in young and adult ones (p<0.001). The numerical density of endoneural cells nuclei in young experimental animals did not differ from that of the intact ones, but in animals from the adult and mature groups it was more than four times higher than in animals from the young group (p<0.001). The numerical density of regenerating myelinated nerve fibers in animals of the young and adult groups did not differ from that of the intact nerve, in animals of the mature group it increased in 2.5 times (p<0.001). The numerical density of degenerating myelinated fibers in the operated animals of experimental groups was higher than in the intact group (two times, six times and 11 times higher, respectively). The diameter distribution of the regenerating myelinated fibers in animals of all groups differed from that of the intact control animals.Conclusions. The data obtained demonstrate a significant decrease in the regenerative potential of Schwann cells and neurons in adult and mature animals compared with the young ones.