Uranyl Acetate Research Articles

Enhance U(VI) reduction on natural pyrite surfaces by gamma irradiation

Pyrite with acid-washed surfaces is chemically inert toward aqueous U(VI) at routine conditions. Given that there is a strong radiation field in the nuclear waste repository, the impact of gamma irradiation on the interaction between aqueous U(VI) and natural pyrite was investigated. Three different natural pyrites, namely Si-, Pb-, and As-pyrites, were used for reactions with uranyl nitrate and uranyl acetate, and the focus was set on Si-pyrite. With an initial pH of ∼ 4.5 and ∼ 6.5, results showed that the solution pH increased mainly due to the reduction of nitrate or the decomposition of acetate caused by the gamma irradiation, while it decreased for the reaction with an initial pH of ∼ 9.0 after gamma irradiation due to the oxidation of aqueous Fe2+. Meanwhile, significant amounts of U(IV)/U(V) were formed on pyrite surfaces at these three pH conditions, demonstrating that gamma irradiation can greatly enhance the U(VI) reduction by pyrite. We proposed that the oxidizing ·OH radical generated by water radiolysis could react with pyrite, leaving the concomitant eaq− and ·H radicals to be effective reductants for aqueous U(VI) or the U(VI)-precipitate formed on pyrite surfaces. Conversely, the impact of gamma irradiation on the U(VI) reduction is insignificant at pH ∼ 3.0, mainly due to the quenching effect of eaq− by H+. Besides, carbonate has an inhibitive effect, because it is a quencher of eaq− and can form anionic complexes with U(VI). The presence of pyrite can also protect UO2 from γ-irradiation-induced oxidation.

Assessment of subchondral bone microdamage quantification using contrast-enhanced imaging techniques.

Bone microdamage is common at subchondral bone (SCB) sites subjected to repeated high rate and magnitude of loading in the limbs of athletic animals and humans. Microdamage can affect the biomechanical behaviour of bone under physiological loading conditions. To understand the effects of microdamage on the mechanical properties of SCB, it is important to be able to quantify it. The extent of SCB microdamage had been previously estimated qualitatively using plain microcomputed tomography (μCT) and a radiocontrast quantification method has been used for trabecular bone but this method may not be directly applicable to SCB due to differences in bone structure. In the current study, SCB microdamage detection using lead uranyl acetate (LUA) and quantification by contrast-enhanced μCT and backscattered scanning electron microscopy (SEM) imaging techniques were assessed to determine the specificity of the labels to microdamage and the accuracy of damaged bone volume metrices. SCB specimens from the metacarpus of racehorses, with the hyaline articular cartilage (HAC) removed, were grouped into two with one group subjected to exvivo uniaxial compression loading to create experimental bone damage. The other group was not loaded to preserve the pre-existing invivo propagated bone microdamage. A subset of each group was stained with LUA using an established or a modified protocol to determine label penetration into SCB. The μCT and SEM images of stained specimens showed that penetration of LUA into the SCB was better using the modified protocol, and this protocol was repeated in SCB specimens with intact hyaline articular cartilage. The percentage of total label localised to bone microdamage was determined on SEM images, and the estimated labelled bone volume determined by μCT in SCB groups was compared. Label was present around diffuse and linear microdamage as well as oblique linear microcracks present at the articular surface, except in microcracks with high-density mineral infills. Bone surfaces lining pores with recent mineralisation were also labelled. Labelled bone volume fraction (LV/BV) estimated by μCT was higher in the absence of HAC. At least 50% of total labels were localised to bone microdamage when the bone area fraction (B.Ar/T.Ar) of the SCB was greater than 0.85 but less than 30% when B.Ar/T.Ar of the SCB was less than 0.85. To adjust for LUA labels on bone surfaces, a measure of the LV/BV corrected for bone surface area (LV/BV BS-1 ) was used to quantify damaged SCB. In conclusion, removal of HAC and using a modified labelling protocol effectively stained damaged SCB of the metacarpus of racehorses and represents a technique useful for quantifying microdamage in SCB. This method can facilitate future investigations of the effects of microdamage on joint physiology.

An effective treatment approach of liposomally encapsulated metformin in colon cancer.

Metformin is a drug that is widely used in the treatment of type-2 diabetes and its anticarcinogenic effect has been detected in many studies since the 2000s. Metformin has a short half-life and poor biocompatibility, which limits the activity of the drug. As a solution to this situation, our study aimed to increase the anticarcinogenic effects and reduce the side effects of metformin in colon cancer by liposomal encapsulation. For this purpose, in our study, liposome production was carried out using the thin film hydration method. The amount of metformin loaded in liposomes was determined by a standard absorbance curve at 237nm. Size distributions and membrane zeta potentials of the liposomes were evaluated with Malvern Zetasizer ZS90. Transmission electron microscopy was performed by staining the liposomes negatively with uranyl acetate. Cultured HT-29 cells were treated with liposomal metformin or free metformin at concentrations of 0, 10, 20, and 40mM for 24 and 48h. At the end of the treatment period, cell viability was evaluated by CellTiter-Glo luminescent cell viability test. The anticarcinogenic effects of liposomal and free metformin on HT-29 cells were compared. As a result, liposome encapsulated metformin treatment for 24h was more effective on HT-29 cells at 20- and 40-mM concentrations causing significantly greater decrease in the IC-50 dose compared to the free metformin. The result suggests that liposomal encapsulated metformin may offer a promising approach to increase the efficacy of the drug in the treatment of colon cancer.

Role of uranium toxicity and uranium-induced oxidative stress in advancing kidney injury and endothelial inflammation in rats

ObjectiveUranium exposure may cause serious pathological injury to the body, which is attributed to oxidative stress and inflammation. However, the pathogenesis of uranium toxicity has not been clarified. Here, we evaluated the level of oxidative stress to determine the relationship between uranium exposure, nephrotoxic oxidative stress, and endothelial inflammation.MethodsForty male Sprague–Dawley rats were divided into three experimental groups (U-24h, U-48h, and U-72h) and one control group. The three experimental groups were intraperitoneally injected with 2.0 mg/kg uranyl acetate, and tissue and serum samples were collected after 24, 48, and 72 h, respectively, whereas the control group was intraperitoneally injected with 1.0 ml/kg normal saline and samples were collected after 24 h. Then, we observed changes in the uranium levels and oxidative stress parameters, including the total oxidative state (TOS), total antioxidant state (TAS), and oxidative stress index (OSI) in kidney tissue and serum. We also detected the markers of kidney injury, namely urea (Ure), creatine (Cre), cystatin C (CysC), and neutrophil gelatinase-associated lipocalin (NGAL). The endothelial inflammatory markers, namely C-reactive protein (CRP), lipoprotein phospholipase A2 (Lp-PLA2), and homocysteine (Hcy), were also quantified. Finally, we analyzed the relationship among these parameters.ResultsTOS (z = 3.949; P < 0.001), OSI (z = 5.576; P < 0.001), Ure (z = 3.559; P < 0.001), Cre (z = 3.476; P < 0.001), CysC (z = 4.052; P < 0.001), NGAL (z = 3.661; P < 0.001), and CRP (z = 5.286; P < 0.001) gradually increased after uranium exposure, whereas TAS (z = −3.823; P < 0.001), tissue U (z = −2.736; P = 0.001), Hcy (z = −2.794; P = 0.005), and Lp-PLA2 (z = −4.515; P < 0.001) gradually decreased. The serum U level showed a V-shape change (z = −1.655; P = 0.094). The uranium levels in the kidney tissue and serum were positively correlated with TOS (r = 0.440 and 0.424; P = 0.005 and 0.007) and OSI (r = 0.389 and 0.449; P = 0.013 and 0.004); however, serum U levels were negatively correlated with TAS (r = −0.349; P = 0.027). Partial correlation analysis revealed that NGAL was closely correlated to tissue U (rpartial = 0.455; P = 0.003), CysC was closely correlated to serum U (rpartial = 0.501; P = 0.001), and Lp-PLA2 was closely correlated to TOS (rpartial = 0.391; P = 0.014), TAS (rpartial = 0.569; P < 0.001), and OSI (rpartial = −0.494; P = 0.001). Pearson correlation analysis indicated that the Hcy levels were negatively correlated with tissue U (r = −0.344; P = 0.030) and positively correlated with TAS (r = 0.396; P = 0.011).ConclusionThe uranium-induced oxidative injury may be mainly reflected in enhanced endothelial inflammation, and the direct chemical toxicity of uranium plays an important role in the process of kidney injury, especially in renal tubular injury. In addition, CysC may be a sensitive marker reflecting the nephrotoxicity of uranium; however, Hcy is not suitable for evaluating short-term endothelial inflammation involving oxidative stress.

Histotopographic Organization of Levator Ani Muscle in Laboratory Rats

Morphological organization of the levator ani muscle still remains unclear due to methodological problems in the study of the pelvic floor muscles. Therefore, the study of the histological structure of muscle tissue m. levator ani in animals is of not only theoretical but also practical importance for the study and modeling of pelvic floor dysfunction conditions in animal models. The aim is to study the enzymohistochemical and ultramicroscopic organization of the levator ani muscle in white laboratory rats. Material and methods. The study was performed on 10 laboratory Wistar rats (5 females and 5 males) aged 12–14 months. The metabolic profile of muscle fibers was determined using the Nachlass succinate dehydrogenase test. Imaging and linear measurements were carried out on a Leica UC 7 microscope (Germany), using its software. Ultrathin sections were counterstained with uranyl acetate and lead citrate, viewed nd photographed using a Hitachi HT 7700 Exalens (Japan) electron microscope. Results. All types of muscle fibers are present in levator ani muscle: slow fibers and rapid muscle fibers of typs IIA and IIB. It has been established that the total cross-sectional area of white type fibers is 3 times greater than the total area of other fibers. Significant sex differences were found in relative square parameters of glycolytic fibers in m. levator ani (p=0,009). At the ultrastructural level, it was found that in some muscle fibers the mitochondrial apparatus is well developed, in others, mitochondria are few in number, have smaller sizes, are located singly between myofibrils, without forming clusters. In such fibers, there are large accumulations of glycogen between the myofibrils. Conclusion. In the laboratory rat, the levator ani muscle is heterogeneous both in metabolic activity of muscle fibers and in ultrastructural organization. This feature of the muscle involves not only static work in creating intra-abdominal pressure and retaining the pelvic organs, but also isotonic contraction, acting as a synergist to ensure the movement of the tail.

Protective effect of Moringa oleifera leaf ethanolic extract against uranyl acetate-induced testicular dysfunction in rats

Uranyl acetate (UA) is used in civilian and military applications, predisposing it to wide dispersion in ecosystems. Using high-performance liquid chromatography, gas chromatography–mass spectrometry, and 2,2-Diphenyl-1-picrylhydrazyl scavenging radical analysis, we confirmed that Moringa oleifera leaf ethanolic extract (MLEE) is rich in biologically active phytochemicals. Thus, this study aims to investigate the possible defensive effect of MLEE against UA-induced testicular dysfunction. To achieve this, rats were divided randomly and evenly into three groups for 14 days. The control group received no treatment, while the UA group received a single intraperitoneal injection of UA at a dose of 5 mg/kg BW dissolved in saline on the 12th day of the experiment, followed by no treatment the following day. The MLEE + UA group received daily oral administration of MLEE (300 mg/kg BW) dissolved in distilled water before exposure to UA intoxication. The disruption observed in the pituitary–gonadal axis of UA-intoxicated rats was characterized by a significant decrease in luteinizing hormone, follicle-stimulating hormone, testosterone, and estradiol 17beta levels. Additionally, there was a notable increase in malondialdehyde and a decrease in catalase, superoxide dismutase, reduced glutathione, and nitric oxide, accompanied by an up-regulation in the immuno-expression of nuclear factor-kappa B, indicating a disturbance in the redox balance. The TUNEL assay confirmed a substantial rise in apoptotic cell numbers in the UA group. Testicular histopathological changes, excessive collagen deposition, and reduced glycogen content were evident following UA exposure. However, supplementation with MLEE effectively countered these mentioned abnormalities. MLEE is proposed to combat the toxicological molecular targets in the UA-affected testis by restoring the balance between oxidants and antioxidants while obstructing the apoptotic cascade. MLEE contains an abundance of redox-stabilizing and cytoprotective phytochemicals that have the potential to counteract the mechanistic pathways associated with UA exposure. These findings encourage further research into other plausible protective aspects of Moringa oleifera against the UA challenge.

The antioxidant role of pumpkin (Cucurbita pepo) seed extract against acute reproductive toxicity by uranyl acetate in male rats.

The main goal of the study was to find whether pumpkin (Cucurbita pepo) extract has any preventive or antioxidant properties against acute uranyl acetate (UA)-induced reproductive cytotoxicity. Four groups each, including 10 adult male rats, were randomly assigned. (GI): the control group was given 1 ml of purified water orally for 30 days. (GII): Rats were given orally, a single dose of 150 mg/kg b.w. UA (GIII): Rats consumed 40 mg/kg b.w. of pumpkin seed extract (PSE) orally every day for 30 days. (GIV): Rats received a single dose (150 mg/kg b.w.) of UA plus a daily oral dose of PSE (40 mg/kg b.w.) for 30 days. Animal sacrifice was used for oxidative stress and histopathological study. Showed significantly (p ≥ 0.001) elevated malondialdehyde levels in the GII group (6.19 ± 0.4), while GIII and GIV showed no significant differences. Glutathione peroxidase showed a significant (p ≥ 0.001) decrease (2.55 ± 0.2) in the GII group, while in groups (GIII and GIV), it showed a significant (p ≥ 0.001) increase (4.61 ± 0.16, 4.28 ± 0.032), respectively. The histopathological study for GII groups showed sloughing of epithelial cells lining the seminiferous tubules with a decrease in the number of spermatozoa in some tubules. Many sections revealed hyperplasia of the epithelial cells lining the seminiferous tubules with necrosis. The GIII and GIV groups showed normal histological structures with an increase in spermatogenesis in the testes and epididymis tissues. We concluded that UA causes oxidative stress and histopathological alterations in the rat reproductive system. Pumpkin extract plays a role in improving the activity of the reproductive system.

Crystal structures of three uranyl-acetate-bipyridine complexes crystallized from hydraulic fracking fluid.

Hydraulic fracking exposes shale plays to acidic hydraulic fracking fluid (HFF), releasing toxic uranium (U) along with the desired oil and gas. With no existing methods to ensure U remains sequestered in the shale, this study sought to add organic ligands to HFF to explore potential U retention in shale plays. To test this possibility, incubations were set up in which uranyl acetate and one organic bipyridine ligand (either 2,2'-, 2,3'-, 2,4'-, or 4,4'-bipyridine) were added to pristine HFF as the crystallization medium. After several months and complete evaporation of all volatiles, bulk yellow crystalline material was obtained from the incubations, three of which yielded crystals suitable for single-crystal analysis, resulting in two novel structures and a high-quality structure of a previously described compound. The UO2VI acetate complexes bis(acetato-κ2O,O')(2,2'-bipyridine-κ2N,N')dioxidouranium(VI), [U(C2H3O2)2O2(C10H8N2)2] or [2,2'-bipyridine]UVIO2(CH3CO2)2, (I), and bis(acetato-κ2O,O')(2,4'-bipyridine-κN1')dioxidouranium(VI), [U(C2H3O2)2O2(C10H8N2)2] or [2,4'-bipyridine]2UVIO2(CH3CO2)2, (III), contain eight-coordinate UVI in a pseudo-hexagonal bipyramidal coordination geometry and are molecular, packing via weak C-H...O/N interactions, whereas catena-poly[bis(2,3'-bipyridinium) [di-μ-acetato-μ3-hydroxido-μ-hydroxido-di-μ3-oxido-hexaoxidotriuranium(VI)]-2,3'-bipyridine-water (1/1/1)], (C10H9N2)2[U3(C2H3O2)2O8(OH)2]·C10H8N2·H2O or {[2,3'-bipyridinium]2[2,3'-bipyridine][(UVIO2)3(O)2(OH)2(CH3CO2)2·H2O]}n, (II), forms an ionic one-dimensional polymer with seven-coordinate pentagonal bipyramidal UVI centers and hydrogen-bonding interactions within each chain. The formation of these crystals could indicate the potential for bipyridine to bind with U in shale during fracking, which will be explored in a future study via ICP-MS (inductively coupled plasma mass spectrometry) analyses of U concentration in HFF/bipyridine/shale incubations. The variation seen here between the molecular structures may indicate variance in the ability of bipyridine isomers to form complexes with U, which could impact their ability to retain U within shale in the context of fracking.

Reactions of gas-phase uranyl formate/acetate anions: reduction of carboxylate ligands to aldehydes by intra-complex hydride attack.

In a previous study, electrospray ionization, collision-induced dissociation (CID), and gas-phase ion-molecule reactions were used to create and characterize ions derived from homogeneous precursors composed of a uranyl cation (UVIO22+) coordinated by either formate or acetate ligands [E. Perez, C. Hanley, S. Koehler, J. Pestok, N. Polonsky and M. Van Stipdonk, Gas phase reactions of ions derived from anionic uranyl formate and uranyl acetate complexes, J. Am. Soc. Mass Spectrom., 2016, 27, 1989-1998]. Here, we describe a follow-up study of anionic complexes that contain a mix of formate and acetate ligands, namely [UO2(O2C-CH3)2(O2C-H)]- and [UO2(O2C-CH3)(O2C-H)2]-. Initial CID of either anion causes decarboxylation of a formate ligand to create carboxylate-coordinated U-hydride product ions. Subsequent CID of the hydride species causes elimination of acetaldehyde or formaldehyde, consistent with reactions that include intra-complex hydride attack upon bound acetate or formate ligands, respectively. Density functional theory (DFT) calculations reproduce the experimental observations, including the favored elimination of formaldehyde over acetaldehyde by hydride attack during CID of [UO2(H)(O2C-CH3)(O2C-H)]-. We also discovered that MSn CID of the acetate-formate complexes leads to generation of the oxyl-methide species, [UO2(O)(CH3)]-, which reacts with H2O to generate [UO2(O)(OH)]-. DFT calculations support the observation that formation of [UO2(O)(OH)]- by elimination of CH4 is favored over H2O addition and rearrangement to create [UO2(OH)2(CH3)]-.

Therapeutic efficacy of S-adenosylmethionine in chronic uranium intoxication in rats

   Introduction. Chronic exposure to uranium compounds causes adverse cytotoxic and immunopathological effects in the body.   The aim of the work was to evaluate the therapeutic efficacy of S-adenosylmethionine when administered intragastrically with respect to hepato-, nephro- and immunotoxic effects in chronic intoxicationwith uranyl acetate dihydrate (UAD).   Materials and methods. Chronic intoxication was modeled by injecting 85 male rats with UAD solution (5.0 mg/kg/day by element) for one month. S-adenosylmethionine was administered to animals at a dose of 72.7 mg/kg for 21 days.   Results. In chronic poisoning with UAD, 65% lethality, decrease of liver mass ratios (MR) and increase of renal MR were observed. Decrease in alkaline phosphatase activity, glucose level, lactic acid, number of CD4+ T-lymphocytes, increase in lactate dehydrogenase activity and creatinine level, number of CD8+ T-lymphocytes and apoptotic cell death, formation of catabolic pool of low and medium molecular weight substances (LMSMS) of blood plasma were registered. The results of urine analysis revealed the development of hyposthenuria, signs of glucosuria, hematosuria, proteinuria and leukocyturia, appearance of bilirubin in the urine. S-adenosylmethionine contributed to the decrease in the degree of target organ damage (reduction of fibroplastic and dystrophic changes in the liver and kidneys), normalization of immune system parameters (increase in CD4+ T-cells, decrease in CD8+ T-cells and frequency of apoptotic death of lymphocytes in immunocompromised animals) and endotoxicosis (decrease in the level of LMSMS from the catabolic pool area).   Discussion. According to the totality of all revealed pathological changes, UAD poisoning led to the development of tubulointerstitial nephritis, metabolic disorders of detoxification functions of the liver. The causes of animal death during the first week of the experiment were acute kidney damage or confluent pneumonia. The appearance of bilirubin in the urine was associated with porphyrin metabolism disorders. In the remote period of intoxication an imbalance of the T-cell link of the immune system developed, as well as, probably, a decrease in nonspecific resistance, which led to the development of pneumonia in rats.   Conclusion. S-adenosylmethionine therapy of hepato-, nephro- and immunotoxic effects in chronic UAD intoxication contributed to a decrease in the degree of damage to target organs, normalization of immune system parameters and endogenous intoxication.

RATS’ THYROID GLAND HISTOLOGICAL AND ULTRASTRUCTURAL CHANGES THROUGHOUT THE EXPERIMENTAL THERMAL INJURY DYNAMICS ON THE BACKGROUND OF HAES-LX 5 % COLLOID-HYPEROSMOLAR SOLUTION INJECTION

The urgency of the burn injury problem is determined by frequent thermal injuries of patients of different ages, the complexity and duration of treatment, long-term disability and relatively high mortality. Depending on the area and depth of the lesion, a burn wound causes multiple and long-lasting disturbances in homeostasis, which cause organs and systems dysfunction. We are interested in the intrathyroid changes that occur during thermal burns, as thyroid gland plays one of the leading roles in the endocrine regulation of organisms’ majority functions. When researching the issue of pharmacological correction of thyroid gland damage after a burn injury, we proceed from the classical fundamental concept regarding its pathogenetic validity. Taking into account the known pathogenetic mechanisms of burn disease with consecutive (and sometimes simultaneous) hypoproteinemia and haemoconcentration manifestations, intoxication formation, inflammatory and autoimmune reaction, we came to a conclusion regarding the reasonability of colloid solutions efficacy testing to attempt the pharmacocorrection in case of thyroid gland both structure and function burning. The purpose of the work is to establish histological and ultrastructural changes in the thyroid gland of experimental rats that were injected with colloidal hyperosmolar solution HAES-LX 5 % in the dynamics of skin thermal damage. Experimental studies were conducted on 90 white male rats. Skin thermal burns were simulated using four copper plates application to previously depilated lateral surfaces of the rats’ body for 10 s. Rats were injected with colloidal hyperosmolar solution HAES-LX 5 % into the vena cava inferior during the first 7 days of the post-burn period. Thyroid gland pieces were fixed in a 10 % neutral formalin solution, dehydrated in alcohols of increasing concentration and embedded in paraffin blocks. The prepared sections of 5-6 μm thickness were stained with hematoxylin-eosin. For electron microscopic studies, pieces of the thyroid gland were taken, fixed in a 2.5% glutaraldehyde solution, and postfixed with a 1% osmium tetroxide solution in a phosphate buffer. Semi-thin sections were stained with methylene blue. Ultrathin sections were contrasted with uranyl acetate, lead citrate according to the Reynolds method and studied in a PEM-125K electron microscope. Colloidal hyperosmolar solution HAES-LX 5 % administration within 7 days of the post-burn period to correct the thermal injury effects has an expressed positive effect on burned animals thyroid gland histo- and ultrastructure. A significant improvement of the structural state of the stromal and parenchymal components of the organ and their relative normalization in the late period under the influence of the applied solution was established in the dynamics of the experiment. The colloidal hyperosmolar solution HAES-LX 5 % positive effects were expressed by cellular walls of the vessels and follicles dystrophic and destructive changes reduction the structural components of the organ restoration during the entire period of the study up to the 30th day of the trial. The first signs of the intraglandular environment recovery after colloidal hyperosmolar solution HAES-LX 5 % use were proved to start registered from the 7th day of the post-burn period and were maximally expressed from the 21st day until the end of the experiment. The authors are sure that colloidal hyperosmolar HAES-LX 5 % solution protective action possible mechanism is the generalized catabolic reaction inhibition and the membrane-protective effect development. A complex of colloidal hyperosmolar solution HAES-LX 5 % protective, adaptive, adaptive, compensatory and regenerative effects were realized throughout the 30 days of the post-burn period, which efficacy exceeds the thyroid gland parenchyma and surrounding tissues destructive, decompensatory and necrotic changes. The authors consider the use of colloidal hyperosmolar solution HAES-LX 5 % to be one of the burn treatment regimen components as a restorative therapy drug and secondary cytoprotection aimed at the vascular wall and tissue defects integrity restoring.

Gallic acid rescues uranyl acetate induced-hepatic dysfunction in rats by its antioxidant and cytoprotective potentials

BackgroundThe liver was identified as a primary target organ for the chemo-radiological effects of uranyl acetate (UA). Although the anti-oxidant and anti-apoptotic properties of gallic acid (GA) make it a promising phytochemical to resist its hazards, there is no available data in this area of research.MethodsTo address this issue, eighteen rats were randomly and equally divided into three groups. One group was received carboxymethyl cellulose (vehicle of GA) and kept as a control. The UA group was injected intraperitoneally with UA at a single dose of 5 mg/kg body weight. The third group (GA + UA group) was treated with GA orally at a dose of 100 mg/kg body weight for 14 days before UA exposure. UA was injected on the 15th day of the experiment in either the UA group or the GA + UA group. The biochemical, histological, and immunohistochemical findings in the GA + UA group were compared to both control and UA groups.ResultsThe results showed that UA exposure led to a range of adverse effects. These included elevated plasma levels of aspartate aminotransferase, lactate dehydrogenase, total protein, globulin, glucose, total cholesterol, triglycerides, low-density lipoprotein cholesterol, and very-low-density lipoprotein and decreased plasma levels of high-density lipoprotein cholesterol. The exposure also disrupted the redox balance, evident through decreased plasma total antioxidant capacity and hepatic nitric oxide, superoxide dismutase, reduced glutathione, glutathione-S-transferase, glutathione reductase, and glutathione peroxidase and increased hepatic oxidized glutathione and malondialdehyde. Plasma levels of albumin and alanine aminotransferase did not significantly change in all groups. Histopathological analysis revealed damage to liver tissue, characterized by deteriorations in tissue structure, excessive collagen accumulation, and depletion of glycogen. Furthermore, UA exposure up-regulated the immuno-expression of cleaved caspase-3 and down-regulated the immuno-expression of nuclear factor-erythroid-2-related factor 2 in hepatic tissues, indicating an induction of apoptosis and oxidative stress response. However, the pre-treatment with GA proved to be effective in mitigating these negative effects induced by UA exposure, except for the disturbances in the lipid profile.ConclusionsThe study suggests that GA has the potential to act as a protective agent against the adverse effects of UA exposure on the liver. Its ability to restore redox balance and inhibit apoptosis makes it a promising candidate for countering the harmful effects of chemo-radiological agents such as UA.

Influence of different sample preparation techniques on imaging viruses and virus-like particles by scanning electron and scanning transmission electron microscopes.

Scanning electron microscopy (SEM) and scanning transmission electron microscopy (STEM) were applied in many laboratories to visualize and image viruses and virus-like particles (VLPs). Two bacteriophages, P1 and Φ6, were chosen as model microorganisms known for their distinct structure, and viruses obtained from biofilms associated with modern travertines (Terme di Saturnia, Italy; Karahayıt "Kızılsu" and Pamukkale, Turkey) were also investigated. Three protocols, (1) full, (2) simplified, and (3) all at once were developed and tested for sample preparation and imaging. The full procedure enabled the observation of P1 bacteriophages, whereas the simplified protocol, successful in visualizing Φ6, did not yield satisfactory results for P1. The preservation state of the latter appeared to be compromised and led to less informative images in SEM and STEM. Viruses in biofilms exhibited various levels of mineralization and aggregation, complicating their characterization. In the all at once procedure, although effective in preserving bacteriophage tails, excessive coating and thickening of samples with heavy chemical reagents led to a reduction in overall image quality. Despite a final washing step, some residues of chemical reagents (OsO4 and uranyl acetate) remained, impacting the clarity of the images. Finally, the results obtained emphasize the critical role of sample preparation and imaging techniques in effectively visualizing and characterizing viruses and VLPs. The choice of analytical procedure significantly influences the resolution and preservation state of the observed bacteriophages and VLPs. It is suggested that the appropriate imaging technique is carefully selected based on the specific objectives of the project and the nature of the samples being investigated to obtain the best images of the viruses.

Abstract 14594: Dual Contrast-Enhanced Micro-Computed Tomography for Simultaneous Characterization of Macrocalcification and Tri-Layered Structural Remodeling in Explanted Human Aortic Valves

Background: Micro-computed tomography (microCT) is excellent for detecting macrocalcification but ineffective at revealing other pathologically relevant structural details in the valves affected by aortic stenosis (AS). Here, we aimed to develop a dual contrast-enhanced microCT technique to simultaneously assess macrocalcification and layer-specific remodeling in diseased human aortic valves. Methods: Diseased (n=15) and normal (n=9) aortic valve leaflets were obtained from human subjects undergoing aortic valve replacement for AS and heart transplantation/autopsy, respectively. Leaflets were fixed (4% paraformaldehyde and 2% glutaraldehyde), stained with dual contrast (1% osmium tetroxide and 1% uranyl acetate), and embedded in epoxy resin. Additional unstained leaflets (n=3 diseased, n=3 normal), similarly processed otherwise, served as staining controls. MicroCT of embedded leaflets was performed using a ZEISS Xradia 520 Versa scanner, with low energy beam (80 kVp, 5 W, LE4 filter) and high-resolution acquisitions (15 μm x 15 μm, 5 sec exposure x 1601 projections). Reconstructed images were analyzed for leaflet/layer thicknesses at midline and macrocalcification volume using Dragonfly. Results: The tri-layered tissue structure was only visualized in stained but not unstained leaflets ( p =0.002). With staining, each layer was found to be thicker in the diseased than the normal leaflets (0.28±0.13 mm vs 0.18±0.07 mm, p =0.0002 for fibrosa; 0.64±0.68 mm vs 0.29±0.19 mm, p =0.012 for spongiosa; 0.32±0.16 mm vs 0.16±0.07 mm, p &lt;0.0001 for ventricularis). The macrocalcification volume in the diseased leaflets was greater than that in the normal leaflets (84.7±84.4 mm 3 vs 0 mm 3 , p &lt;0.0001) and correlated only with the thickness of spongiosa ( r =0.79, p &lt;0.001) but not other layers ( p =0.67, p =0.26). Macrocalcification was as frequently observed in spongiosa as in fibrosa (66.7% vs 66.7% of diseased leaflets, p =0.3) but never in ventricularis. Conclusions: Dual contrast-enhanced microCT enables high-quality imaging of both macrocalcification and layer-specific remodeling in diseased human aortic valves. The results here suggest an intimate relationship between macrocalcification and spongiosa that warrants further investigation.

Investigation of the Efficacy of Lanthanoid Heavy Metal Acetates as Electron Staining Reagents for Biomembrane Vesicles.

Transmission electron microscopy (TEM) has revolutionized our understanding of protein structures by enabling atomic-resolution visualization without the need for crystallography, thanks to advancements in cryo-TEM and single particle analysis methods. However, conventional electron microscopy remains relevant for studying stained samples, as it allows the practical determination of optimal conditions through extensive experimentation. TEM also facilitates the examination of supramolecular complexes encompassing proteins, lipids, and nucleic acids. In this study, we investigated the applicability of lanthanoid reagents as electron-staining alternatives to uranyl acetate, which is globally regulated as a nuclear fuel material. We focus on a model biomembrane vesicle system, the chromatophores from the purple photosynthetic eubacterium Rhodospirillum rubrum, which integrate proteins and lipids. Through density distribution analysis of electron micrographs, we evaluated the efficacy of various lanthanoid acetates and found that triacetates of neodymium, samarium, and gadolinium exhibited similar staining effectiveness to uranyl acetate. Additionally, triacetates of praseodymium, erbium, and lutetium, followed by europium show promising results as secondary candidates. Our findings suggest that lanthanoid transition heavy metal acetates could serve as viable alternatives for electron staining in TEM, offering potential advantages over uranyl acetate.

Study on Morphological Changes and Interference in the Development of Aedes aegypti Caused by Some Essential Oil Constituents.

Dengue, Chikungunya and Zika are arboviruses, transmitted by the mosquito Aedes aegypti, that cause high mortality and serious health consequences in human populations. Efforts to control Ae. aegypti are important for preventing outbreaks of these diseases. Essential oil constituents are known to exhibit many activities, such as their use as larvicides. Given their potential, the present study aimed to characterize the larvicidal effect of dihydrojasmone, p-cymene, carvacrol, thymol, farnesol and nerolidol on the larvae of Ae. aegypti and their interference over the morphology of the mosquitos. The essential oil constituents were dissolved in dimethylsulfoxide at concentrations of 1-100 μg/mL and were applied in the breeding environment of third-stage larvae. The larvae from bioassays were fixed, dehydrated and embedded. Ultrathin sections were contrasted using 5% uranyl acetate and 1% lead citrate for observation through transmission electron microscopy. The oil with the highest larvicidal efficiency was found to be nerolidol, followed by farnesol, p-cymene, carvacrol, thymol and dihydrojasmone, with an LC50 of 11, 21, 23, 40, 45 and 66 µg/mL, respectively. The treated Ae. aegypti larvae caused alteration to the tegument or internal portions of larvae. The present study demonstrated which of these oils-dihydrojasmone, farnesol, thymol, p-cymene, carvacrol and nerolidol-have effective larvicidal activity.

Transmission electron microscopy of electrophoretic humic acids fractions obtained by coupling size exclusion chromatography-polyacrylamide gel electrophoresis: The next step to understanding structural organization of soil humic matter

The transmission electron microscopy (TEM) with contrast staining by uranyl acetate solution was used to study morphological differences between soil humic acids (HAs) and their A, B and C + D fractions obtained using coupling preparative low-pressure size exclusion chromatography and analytical polyacrylamide gel electrophoresis. The electrophoretic mobility of fractions varied in order C + D > B > A. The distribution of various morphological elements between the bulk HAs and their fractions clearly showed that larger structures, such as smeared drops (70–150 nm long), were formed exclusively in fraction A, whereas elongated fibers (60–100 nm long) and their bundles (>150 nm long) were found only in fraction C + D. Smaller morphological elements such as point particles (2–3 nm in diameter), ring particles (4–6 nm in diameter) with hole in the center, worm-like short particles (20–30 nm long) and spheroids (10–30 nm in diameter) were observed in all samples, but in varying quantities. Significant morphological differences between the samples can be explained by their contrasting properties obtained earlier by different physical–chemical methods. The ratio Car(165–108 ppm)/Calk (108–0 ppm) or aromaticity derived from 13C NMR data appears to be one of the indicators for the formation of different morphological structures. This study provides the new information about morphological structures of soil organic matter that are consistent with the formation of different supramolecular aggregates, probably controlled by the association of smaller ring particles. The data obtained can clarify the role of humic acids in the environment and their involvement in physical–chemical processes in soils.

[Signal transducer and activator of transcription 6 mediates skeletal muscle cell injury in septic mice by regulating ferroptosis].

To explore the effect of signal transducer and activator of transcription 6 (STAT6) on ferroptosis in skeletal muscle cells in sepsis model and its potential mechanism. Twenty-four 8-week-old male specific pathogen free Kunming mice were divided into normal control group, sham group, sepsis model group and STAT6 inhibitor pretreatment group according to random number table method with 6 mice in each group. A mouse sepsis model was reproduced by cecal ligation and perforation (CLP). In the sham group, the skin of mice was sutured after exposing the cecum tissue. In the STAT6 inhibitor pretreatment group, 10 mg/kg AS1517499 was injected intraperitoneally 1 hour before model reproduction. The sham group and the model group were intraperitoneally injected with the same volume of normal saline. Mice in the normal control group did not receive any operation or drug intervention. The mice were sacrificed 24 hours after model reproduction, and the muscle tissue of hind limb was obtained under sterile condition. Hematoxylin-eosin (HE) staining was used to observe the histopathology with optical microscope, and mitochondrial morphological changes were observed by transmission electron microscopy after double staining with uranium acetate lead citrate. The ferroptosis marker proteins expressions of chitinase-3-like protein 1 (CHI3L1), cyclooxygenase-2 (COX-2), acyl-CoA synthetase long-chain family member 4 (ACSL4), ferritin heavy chain 1 (FTH1), and glutathione peroxidase 4 (GPx4) were detected by Western blotting. Under the optical microscope, the morphology and structure of skeletal muscle tissues in the normal control and sham groups were normal. In the model group, the structure of skeletal muscle tissues was loose, the muscle fiber became smaller and atrophic, inflammatory cell infiltration and even muscle fiber loss were found. Compared with the model group, the structure of skeletal muscle tissues was tight and skeletal muscle atrophy was improved in the STAT6 inhibitor pretreatment group. The ultrastructure of skeletal muscle cell in the normal control and sham groups was normal under transmission electron microscope. The ultrastructure characteristics of skeletal muscle in the model group showed that cell membrane was broken and blister, mitochondria became smaller and membrane density increased, the mitochondrial crista decreased or disappeared, the mitochondrial outer membrane was broken, and the nucleus was normal in size but lacked chromatin condensation. Compared with the model group, the STAT6 inhibitor pretreatment group had a significant improvement in the ultrastructure of muscle cells. Compared with the normal control and sham groups, the protein expressions of CHI3L1, COX-2, ACSL4 and FTH1 in the muscle of the model group were significantly increased, while the protein expression of GPx4 was decreased significantly, indicating that the skeletal muscle cells in the mouse sepsis model showed characteristic mitochondrial injury and abnormal expression of ferroptosis markers. Compared with the model group, the protein expressions of CHI3LI, COX-2, ACSL4 and FTH1 in the STAT6 inhibitor pretreatment group were significantly decreased [CHI3L1 protein (CHI3L1/GAPDH): 0.70±0.08 vs. 0.97±0.09, COX-2 protein (COX-2/GAPDH): 0.61±0.03 vs. 0.83±0.03, ACSL4 protein (ACSL4/GAPDH): 0.75±0.04 vs. 1.02±0.16, FTH1 protein (FTH1/GAPDH): 0.49±0.06 vs. 0.76±0.13, all P < 0.05], while the protein expression of GPx4 was significantly increased (GPx4/GAPDH: 1.14±0.29 vs. 0.53±0.03, P < 0.05). Sepsis can induce ferroptosis in skeletal muscle cells of mice. STAT6 may mediate ferroptosis in mouse skeletal muscle cells by regulating the expressions of COX-2, ACSL4, FTH1 and GPx4, thereby inducing skeletal muscle cell injury in sepsis.

Organization of histo-hematic barriers of the liver in Anglo-Nubian goat

The aim of this research was to establish features of the liver histo-hematic barriers ultrastructural organization of the Anglo-Nubian goat. The liver of an adult Anglo-Nubian goat was used as the material. The work was carried out using the electron microscopic method. Liver parenchymal tissue fragments were selected. These samples were fixed in a 2.0% glutaraldehyde solution on a cacodylate buffer for two hours. They were then washed in three portions of the same buffer and post-fixed in a 1.0% solution of osmium tetrachloride for one hour. The samples were then dehydrated in alcohols of ascending concentration and absolute acetone. The subsequent filling of the fragments was carried out in Epon-812. Ultrathin sections were obtained on an ultramicrotome, contrasted with a 2.0% aqueous solution of uranyl acetate and a solution of lead citrate. The ultrathin sections were photographed with a Jem-1011 electron microscope at magnifications of 2500-3000. Two histo-hematic barriers are detected in the liver of the studied animals hemato-hepatic and hepatobiliary. The hemato-hepatic barrier is formed by the plasmalemma of the apical end of the hepatocyte, covered by the glycocalyx, the perisinusoidal space of the Disse, the endotheliocyte of the sinusoid capillary, as well as Kupfer cells located in the lumen of the latter. The hepatobiliary includes all of the above structures, with the exception of Kupfer cells, as well as the plasmalemma of the basal end of the hepatocyte. All of the above structures in their organization have characteristic species features for Anglo-Nubian goats.

An experimental study for the identification of some bacterial strains for uranium bioremediation by gamma spectrometry

In this work, it was aimed to determine the potential bacterial strains that can be bioremediated of the radioactive uranium. The experimental analysis was made in gamma spectrometry. Uranyl acetate (CH3COO)2UO2.2H2O was used as the radioactive material. The radioactive solutions containing bacterial strains (P. chlororaphis (3N17-10); B. licheniformis (1N17-3); L. casei (NM-25); L. plantarum (NM-10); L. brevis (NM-26); L. lactis (NM-41); L. curvatus (NM-1); L. pentosus (NM-38); L. coryniformis (NM-22) and B. subtilis (N-28)) were prepared. A high purity germanium detector with a resolution of 490 eV at 122 keV was used to measure the photon intensities emitted from the radioactive solutions. The removal percentage and adsorbed amount of the investigated samples were determined. The results showed that P. chlororaphis have got an excellent sorption capacity for uranium removal.