Animal Tissues Research Articles

Evaluation of the Hepatotoxicity of Buprenorphine in Rat Pups Born to an Exposed Mother During Lactation.

This study aimed to evaluate the hepatotoxicity of buprenorphine in lactating rat pups of buprenorphine-injected mothers. Buprenorphine (BUP), a semisynthetic opioid, is increasingly administrated as a first-line standard maintenance treatment for opioid dependence due to its high safety and efficacy compared to other opioids. Numerous studies have confirmed the safety of BUP maintenance treatment in addicted patients. This study was designed to assess the effects of BUP on the activities of liver enzymes, oxidative parameters, and liver histopathological changes in pups born to a mother exposed to this drug during lactation. BUP at a dose of 0.5 or 0.1 mg/kg was subcutaneously administrated to lactating rats for 28 days. At the end of the experiment, the pups were anesthetized, and blood samples were obtained from their hearts for measuring liver enzymes. Then the livers of the animals were dissected to measure oxidative stress parameters. In addition, the liver samples were fixed for histopathological evaluation. The findings indicated a decrease in the activities of serum liver enzymes (ALT and AST) of the pups born to mothers exposed to 0.5 and 1 mg/kg of BUP during lactation. BUP could not change malondialdehyde (MDA), glutathione (GSH), nitric oxide (NO) levels, nor superoxide dismutase (SOD) activity in the liver tissue of animals. Some vacuolated hepatocytes with dark, eccentric nuclei, necrosis with karyolytic nuclei, mitotic figures, and multiple binucleated cells were seen in the pups which received 1 mg/kg of BUP. In conclusion, BUP may induce liver dysfunction in pups born to mothers exposed to this drug during lactation.

Sr/Ca ratios indicate frugivory versus folivory in primates: a case study using handheld XRF in Kibale National Park, Uganda.

Researchers often use trace element concentrations, including strontium-calcium ratios (Sr/Ca), to reconstruct paleodiets. While most commonly used as a proxy for meat consumption, a more appropriate application may be to differentiate frugivory from folivory. Sr/Ca ratios in animal tissue reflect the Sr/Ca ratios of the highest calcium components of that animal's diet. Because plants have much higher concentrations of calcium than meat, meat consumption signals are often overwhelmed by the variation in Sr/Ca ratios coming from different plant parts. This study uses faunal and plant data from Kibale National Park, a protected forest in southwestern Uganda home to numerous primate species (for example, common chimpanzees and baboons), to assess the reliability of Sr/Ca ratios to differentiate between primate dietary groups. We find that leaves consistently have higher strontium and calcium concentrations than fruits and that this is mirrored in higher Sr/Ca ratios in folivorous primates compared to frugivorous primates. Plant species differ widely in both their overall Sr/Ca ratios and the differences between their fruit and leaf Sr/Ca ratios, but this variation does not overwhelm the dietary signal separating frugivores and folivores. Furthermore, this research demonstrates that non-destructive and portable X-ray florescence (XRF) methods are an effective means of gathering Sr/Ca data from plant and faunal material, increasing the opportunities to apply such methods to fossil material in the future.

4D in vivo dosimetry for a FLASH electron beam using radiation-induced acoustic imaging

Objective. The primary goal of this research is to demonstrate the feasibility of radiation-induced acoustic imaging (RAI) as a volumetric dosimetry tool for ultra-high dose rate FLASH electron radiotherapy (FLASH-RT) in real time. This technology aims to improve patient outcomes by accurate measurements of in vivo dose delivery to target tumor volumes. Approach. The study utilized the FLASH-capable eRT6 LINAC to deliver electron beams under various doses (1.2 Gy pulse−1 to 4.95 Gy pulse−1) and instantaneous dose rates (1.55 × 105 Gy s−1 to 2.75 × 106 Gy s−1), for imaging the beam in water and in a rabbit cadaver with RAI. A custom 256-element matrix ultrasound array was employed for real-time, volumetric (4D) imaging of individual pulses. This allowed for the exploration of dose linearity by varying the dose per pulse and analyzing the results through signal processing and image reconstruction in RAI. Main Results. By varying the dose per pulse through changes in source-to-surface distance, a direct correlation was established between the peak-to-peak amplitudes of pressure waves captured by the RAI system and the radiochromic film dose measurements. This correlation demonstrated dose rate linearity, including in the FLASH regime, without any saturation even at an instantaneous dose rate up to 2.75 × 106 Gy s−1. Further, the use of the 2D matrix array enabled 4D tracking of FLASH electron beam dose distributions on animal tissue for the first time. Significance. This research successfully shows that 4D in vivo dosimetry is feasible during FLASH-RT using a RAI system. It allows for precise spatial (∼mm) and temporal (25 frames s−1) monitoring of individual FLASH beamlets during delivery. This advancement is crucial for the clinical translation of FLASH-RT as enhancing the accuracy of dose delivery to the target volume the safety and efficacy of radiotherapeutic procedures will be improved.

Sevoflurane enhances autophagy via Rac1 to attenuate lung ischaemia‒reperfusion injury

Sevoflurane can attenuate lung ischaemia‒reperfusion injury (LIRI). However, the protective mechanism is unclear. In this study, we developed a LIRI model in vivo that animals (SD, n = 15) were subjected to the administration of 2.2 % sevoflurane 30 min before the onset of left pulmonary artery clamping for 45 min, which was then followed by 60 min of reperfusion treatment. Then, transcriptome sequencing was used to analyse lung tissues. Autophagy inhibition (3-MA) and Rac1-overexpression transfection plasmids were used in BEAS-2B cells, and BEAS-2B cells were subjected to hypoxia reoxygenation (H/R) and sevoflurane treatment. In both animal tissue and cells, inflammatory cytokines and apoptotic and autophagy molecules were measured by quantitative real-time PCR, western blotting and immunostaining. As a result, decreased arterial partial oxygen and damage to the histological structure of lung tissues were observed in LIRI model rats, and these effects were reversed by sevoflurane treatment. Activation of inflammation (elevated IL-1β, IL-6, and TNF-α) and apoptosis (elevated cleaved caspase3/caspase3 and Bax, degraded expression of Bcl2) and inhibition of autophagy (elevated P62, degraded expression of Beclin1 and LC3-II/LC3I) in the model group were ameliorated by sevoflurane. Transcriptome sequencing indicated that the PI3K/Akt pathway regulated by Rac1 plays an important role in LIRI. Furthermore, overexpression of Rac1 in a cell line inhibited the protective effect of sevoflurane in LIRI. Autophagy inhibition (3-MA) also prevented the protective effect of sevoflurane on inflammation and apoptosis.As shown in the present study, sevoflurane enhances autophagy via Rac1/PI3K/AKT signalling to attenuate lung ischaemia‒reperfusion injury.

Cadmium nanocluster as a safe nanocarrier: biodistribution in BALB/c mice and application to carry crocin to breast cancer cell lines.

Metal nanoclusters are emerging nanomaterials applicable for drug delivery. Here, the toxicity and oxidative stress induction of divalent cationic cadmium (Cd2+) was compared with a Cd in the form of nanocluster. Then, it was used for targeted drug delivery into breast cancer cell lines. Using a green chemistry route, a Cd nanocluster (Cd-NC) was synthesized based on bovine serum albumin. After characterization, its genotoxicity and oxidative stress induction were studied in both in vitro and in vivo. After that, it was conjugated with hyaluronic acid (HA). The efficiency of hyaloronized-Cd-CN (HA-Cd-NC) for loading and releasing crocin (Cro), an anticancer phytochemical, was studied. Finally, it was applied for cell death induction in a panel of breast cancer cell lines. The comet assay results indicated that, unlike Cd2+ and potassium permanganate (KMnO4), no genotoxicity and oxidative stress was induced by Cd-NC in vitro. Then, the pharmacokinetics of this Cd-NC was studied in vivo. The data showed that Cd-NC has accumulated in the liver and excreted from the feces of mice. Unlike Cd2+, no toxicity and oxidative stress were induced by this Cd-NC in animal tissues. Then, the Cd-NC was targeted toward breast cancer cells by adding HA, a ligand for the CD44 cell surface receptor. After that, Cro was loaded on HA-Cd-NC and it was used for the treatment of a panel of human breast cancer cell lines with varying degrees of CD44. The half-maximal drug inhibitory concentration (IC50) of Cro was significantly decreased when it was loaded on HA-Cd-NC, especially in MDA-MB-468 with a higher degree of CD44 at the surface. These results indicate the higher toxicity of Cro toward breast cancers when carried out by HA-Cd-NC. The Cd-NC was completely safe and is a promising candidate for delivering anticancer drugs/phytochemicals into the targeted breast tumors.

Estimating nitroxynil residues in food samples and surface water using two different sustainable chemical sensing techniques: Comparative greenness, whiteness, and blueness study

The presence of veterinary drug residues in edible animal tissues endangers human health and safety, accordingly, global nations enacted legislative restrictions to monitor their concentrations in food. In this work, we introduce two fluorimetric sensors for determining nitroxynil (NXL), a crucial veterinary medication, in various matrices. Sensor I, novel nitrogen and sulfur-doped carbon quantum dots (S,N-CQDs), was fabricated from strawberry and leek juices as cheap and sustainable natural resources. Only five minutes of microwave radiation were required as a rapid synthesizing technique without any drastic conditions or organic solvents. The S,N-CQDs manifest blue emission using λex/em of 340/418 nm. The synthesized nanosensor was characterized using UV Spectroscopy, transmission electron microscopy (TEM), and Fourier-transform infrared spectrometry (FTIR). Sensor II was the acriflavine reagent (AV) that exhibits native fluorescence using λex/em of 265/505 nm. Both sensors displayed quantitative turning off in their native fluorescence by increasing concentrations of NXL (1.0–10.0 and 0.5–8.0 µg mL−1) with correlation coefficients r = 0.9998 and 0.9999 for sensors I and II, respectively. The two probes achieved satisfactory percentage recoveries and standard deviation (SD < 4) for NXL assessing in complex matrices of diverse food samples (bovine muscle, kidney, and fat) and Fasciolar® veterinary formulation. Additionally, they have been successfully used to detect the investigated drug in river ecosystems with a mean %recovery of 100.10 ± 1.70, and 99.95 ± 1.31 for sensors I and II, respectively. The two constructed sensors’ specificity has been confirmed for all tested matrices reflecting their feasibility as promising platforms in therapeutic drug monitoring, livestock ecosystems, food safety assurance, quality control of drugs, and environmental pollution monitoring. Quenching mechanisms for both methodologies were studied and the reaction stoichiometry for NXL − AV complex was calculated in two ways. Lastly, a comprehensive comparison was performed between the suggested methodologies and published fluorimetric works. The greenness feature was assessed by the Analytical Eco-scale (AES), Green Analytical Procedure Index (GAPI), and Analytical GREEnness Metric Approach (AGREE). In addition, white analytical chemistry principles were checked to assess sustainability criteria using the RGB 12 algorithm. The recently launched Blue Applicability Grade Index (BAGI) metric tool was also employed to assess the practicality (Blueness) character.

Comparing the effects of Bone+B® xenograft and InterOss® xenograft bone material on rabbit calvaria bone defect regeneration.

The bone regeneration therapy is often used in patients with inadequate bone support for implants, particularly following tooth extractions. Xenografts derived from animal tissues are effective bone reconstructive options that resist resorption and pose a low risk of transmitting disease. Therefore, these implants may be a good option for enhancing and stabilizing maxillary sinuses. The purpose of this study was to compare two xenografts, Bone+B® and InterOss®, for the reconstruction of rabbit calvaria defects. The study involved seven male New Zealand white rabbits. In the surgical procedure, 21 spots were created on both sides of the midline calvarium by creating three 8-millimeter defects. A control group was used, as well as two treatment groups utilizing Bone+B® Grafts and InterOss® Grafts. After 3 months, the rabbits were euthanized, followed by pathological evaluation. Analysis of these samples focused on bone formation, xenograft remaining material, and inflammation levels, using Adobe Photoshop CS 8.0 and SPSS version 24. With the application of Bone+B® graft, bone formation ranged from 32% to 45%, with a mean of 37.80% (±5.63), and the remaining material ranged from 28% to 37%, with a mean of 32.60% (±3.65). Using InterOss® grafts, bone formation was 61% to 75%, the mean was 65.83% (±4.75), and the remaining material was 9% to 18%, with a mean of 13.17% (±3.06). The bone formation in the control group ranged from 10% to 25%, with a mean of 17.17% (±6.11). InterOss® had lower inflammation levels than other groups, but the difference was not statistically significant (p > .05). InterOss® bone powder is the best option for maxillofacial surgery and bone reconstruction. This is due to more bone formation, less remaining material, and a lower inflammation level. Compared to the control group, Bone+B® improves healing and bone quality, thus making it an alternative to InterOss®.

Mathematical description of protein extraction from muscle tissue of hydrobionts and determination of the effective molecular diffusion coefficient

The purpose of this work is to obtain an array of experimental data, kinetic dependences of the protein extracting from the particles of dispersed muscle tissue of hydrobionts (Alaska pollack), its mathematical description, and to find the molecular diffusion coefficients of proteins in the system of equations using solving the inverse problem of the modeling. This work’s novelty is to study swelling and protein extraction from animal tissue and its mathematical description. This study has established that the diffusion of proteins from the muscle tissue of hydrobionts during stirring suspension (raw material-extractant) occurs at a significantly higher rate than diffusion from raw materials of plant origin. It indicates the contribution of a convective component to the swelling process and dissolution of particles due to intensive blending and easy differentiability of muscular tissue particles of hydrobionts. Based on the solution of the mathematical model, the molecular diffusion coefficient of proteins from raw materials of animal origin (muscle tissue of hydrobionts) (3÷8)×10−9 m2/s, which exceeds the diffusion coefficients of carbohydrates from raw materials of plant origin (e.g., sugar 0.3×10−9 m2/s) by more than an order of magnitude. Researchers can use the obtained molecular diffusion coefficient to calculate the parameters of the diffusion process of proteins during its extraction from dispersed particles of hydrobionts.

Tidal zone effects on the diet composition of leaf-eating crabs in natural mangrove communities: a stable isotope analysis

BackgroundIn natural mangrove communities, mangrove species are often distributed zonally. Leaf-eating crabs are one of the most abundant and iconic arboreal brachyurans in mangrove forests, but variation in the composition of crab diets in different mangrove tidal zones is unknown.MethodsTo determine the contributions of mangrove leaves and other organic carbon (C) sources to leaf-eating crab diets, dual stable C and nitrogen (N) isotope signatures (δ13C and 1δ5N) were used in a Bayesian stable isotope mixing model. We conducted experiments at various tidal levels in the Dongzhaigang Bay National Natural Reserve in China. We analyzed δ13C and δ15N of leaf-eating crabs, mangrove leaves, sediment organic matter (SOM), and animal tissues (prey).ResultsThe food composition of the dominant crab species, Parasesarma continentale, exhibited significant differences among the four tidal zones. From the margin to the high tide zone, the main food source shifted from predominantly mangrove leaves and SOM to primarily SOM and animal tissues. We observed a significant negative relationship between the C/N ratios of mangrove leaves and the proportion of leaves consumed by leaf-eating crabs. Additionally, as the tidal level increased, the C/N ratio of mangrove leaves also increased, whereas the proportion of leaves consumed by crabs decreased.ConclusionLeaf-eating crab diets vary significantly across tidal zones, highlighting the importance of considering tidal zone differentiation when studying consumer diets in mangrove ecosystems.

#2651 Microwave tissue digestion and flame atomic absorption spectroscopy for measuring tissue sodium content in CKD patients

Abstract Background and Aims Skin and muscle sodium accumulation has been demonstrated in CKD patients and may contribute to progression of the disease. Various methods are available for measuring tissue sodium content. However, the accuracy and reproducibility of these methods remain unknown. Dry ashing is the most used digestion method, but is expensive, time consuming and has a risk of incomplete digestion. This study compared microwave digestion, dry ashing, and two electrolyte quantification methods for quantifying tissue sodium and potassium. Method We compared microwave digestion (Ethos LEAN Compact Microwave Digestion System, Milestone SRL) and dry ashing (Nabertherm S27) as sample preparation methods, and flame atomic absorption spectroscopy (FAAS, Model 425 Flame Photometer, Sherwood Scientific) and inductively coupled plasma optical emission spectrometry (ICP-OES, Varian 720-ES, Varian Inc.) as electrolyte quantification methods. Skin and muscle samples were obtained from rats and mice, and human skin samples were used. Tissues biopsies were cut in three pieces and digested separately. The methods were compared using interclass correlation coefficient (ICC) and Bland-Altman analysis. The third piece of tissue was microwave-digested by another operator to test inter-operator reproducibility by calculating the ICC and absolute overall mean difference. Results With microwave digestion and FAAS median (IQR) human skin concentration was 114.8 (99.2-157.0, n = 12) mmol/L, confirming tissue sodium storage. When including all tissues, FAAS and ICP-OES showed high agreement for sodium (ICC 0.98, bias –0.00008 mmol/g, n = 141 and potassium (ICC 0.98, bias –0.005 mmol/g, n = 141). Microwave digestion and ashing showed agreement for sodium (ICC 0.93, bias –0.002 mmol/g, n = 61) and potassium (ICC 0.93, bias –0.02 mmol/g, n = 61). The inter-operator agreement was good for sodium (ICC 0.95, absolute mean difference (SD) 0.044 mmol/g (0.073), n = 70) and potassium (ICC 0.96, absolute mean difference (SD) 0.031 mmol/g (0.032), n = 70). Conclusion Microwave digestion with FAAS is a reliable and consistent method for sodium and potassium trace analysis in animal and human tissues compared to ashing and ICP-OES, respectively. This method showed more quantification of cations than the most frequently reported method, representing an easier, and less time-consuming way to quantify tissue sodium in CKD research.

Current state of in situ gene expression studiesin animal tissues

Morphological studies of farm animals are most often conducted using simple preparation and staining techniques. The study of the processes of embryogenesis, postembryonic features of the development of organs and tissues, as well as the effect of various substances remains to be elucidated not only using histochemical and immunohistochemical staining methods, but also using RNA in situ hybridization and transcriptome in situ sequencing. Aspects of many cellular and tissue processes for cattle, pigs and chickens in the context of comparative physiology have not yet been studied. The high productivity of farm animals is associated with the intensive functioning of all organs and systems of the body. The influence of the agricultural management of farm animals and its consequences on the development of an organism in ontogeny deserve a separate area of research from the point of in situ gene expression. Despite rapid development of transcriptome sequencing technologies, which result in the discovery of new candidate genes for many processes, RNA in situ hybridization remains the gold standard for their validation. This review briefly presents modern techniques and their modifications for studying in situ gene expression. Transcriptome studies that have been implemented in cattle, pigs and chickens as model organisms include: in situ RNA hybridization using ZZ-probes, tyramide signal amplification, hybridization chain reaction, digoxigenin-labeled probes, RT-PCR, single cell transcriptome sequencing, in situ transciptome sequencing. This paper is a review of the results of studies on cattle, pigs and chickens. The results of research in this area are relevant for understanding the features of adaptation mechanisms at the transcriptomic level in highly productive animals under industrial conditions in order to search for new markers of valuable agricultural traits. It should be noted that in literature there are very few studies using RNA in situ hybridization, despite the availability and simplicity of the method.

Hydroxyapatite: An Eco-Friendly Material for Enzyme Immobilization.

Biocatalysis has emerged in the last decade as a valuable and eco-friendly tool in chemical synthesis, allowing in several instances to reduce or eliminate the use of hazardous reagents, environmentally dangerous solvents and harsh reaction conditions. Enzymes are indeed able to catalyse chemical transformations on non-natural substrates under mild reaction conditions, still maintaining their high chemo-, regio-, and stereoselectivity. Enzyme immobilization, i. e. the grafting of enzymes on solid supports, can be viewed as an enabling technology, as it allows a better control of the reaction and the recycling of the biocatalyst, thus rendering economically viable the use of expensive enzymes also on a large scale. To pursue a sustainable approach, the supports for enzyme immobilization should be eco-friendly and possibly renewable. This review highlights the use of hydroxyapatite (HAP), an inorganic biomaterial able to confer strength and stiffness to the bone tissue in animals, as carrier for enzyme immobilization. HAP is a cheap, non-toxic and biocompatible material, with high surface area and protein affinity. Different enzyme classes, immobilization strategies, and the use of diverse HAP-based supports will be discussed, underlining the immobilization conditions and the properties of the obtained biocatalysts.

Effects of eyestalk ablation and seawater temperature on d-glutamate levels in the reproductive tissues of male kuruma prawn Marsupenaeus japonicus.

D-Glutamate, a novel d-amino acid found in animal tissues, exclusively exists in the male reproductive tissues of the kuruma prawn, Marsupenaeus japonicus. Herein, changes in the d-glutamate content were determined in the male reproductive tissues of M. japonicus during acclimation to breeding seawater temperatures of 18-22°C and unilateral eyestalk ablation. The d-glutamate content in the testis increased with increasing seawater temperature and with unilateral eyestalk ablation. This suggests that both stimulations induced d-glutamate synthesis in the testis. Although the d-alanine content in the testis increased after unilateral eyestalk ablation, it did not change with elevated seawater temperature. Furthermore, we determined the d-glutamate distribution in the M. japonicus spermatophore. This indicates that d-glutamate is crucial in prawn fertilization.

Effects of Hydrolyzed Collagen as a Dietary Supplement on Fibroblast Activation: A Systematic Review.

Our objective was to conduct a systematic review of the effects of hydrolyzed collagen supplementation on the proliferation and activation of fibroblasts. The search was conducted for journals that published articles in the English language, peer-reviewed, meeting the following criteria: (a) randomized clinical trials, (b) randomized studies in animals or humans, (c) in vitro studies, (d) studies using hydrolyzed collagens or collagen peptides, and (e) studies assessing alterations on fibroblasts as the primary or secondary outcome. We utilized the main journal databases PubMed/Web of Science and ongoing reviews by PROSPERO. For bias risk and methodological quality, we used an adaptation of the Downs and Black checklist. Our review followed the PRISMA checklist, conducted from February 2024 to the first week of March 2024, by two independent researchers (P.A.Q.I. and R.P.V.). Eleven studies were included in this review, where our findings reinforce the notion that hydrolyzed collagens or collagen peptides at concentrations of 50-500 μg/mL are sufficient to stimulate fibroblasts in human and animal tissues without inducing toxicity. Different enzymatic processes may confer distinct biological properties to collagens, allowing for scenarios favoring fibroblast promotion or antioxidant effects. Lastly, collagens with lower molecular weights exhibit greater bioavailability to adjacent tissues. Hydrolyzed collagens or collagen peptides with molecular sizes ranging from <3 to 3000 KDa promote the stimulation of fibroblasts in human tissues.

DYNAMIC CHANGES IN HISTOLOGICAL AND MORPHOMETRIC INDICATORS OF THE LUNGS IN SEXUALLY IMMATURE RATS DURING SIMULATION OF PARTIAL TRACHEAL STENOSIS

Introduction. The morphological features of the respiratory system in laryngomalacia remain insufficiently understood, particularly regarding structural, cytological, and functional alterations. The aim of this study is to investigate the morphological characteristics of the respiratory compartment in the lungs of sexually immature rats, conduct a morphometric assessment of lung tissue density, analyze the dynamics of erythrocyte mass and collagen accumulation, and identify correlations between these parameters. Materials and Methods: The study involved sexually immature male Wistar rats aged 25-28 days and weighing 40-55 g. Partial tracheal stenosis was induced in experimental animals using a developed method, restricting the tracheal lumen by 20-25%. The stenosis was maintained for 7 and 21 days in different groups. In one group, tracheal stenosis was relieved after 7 days by removing the compressive ligature. Histological, histochemical, and morphometric methods were employed to study changes in lung tissue. Results. Pathological changes in lung tissue during hypoxia were characterized by an increase in the number of different types of cells and erythrocyte mass, especially on the 21st day of the experiment and the removal of ligatures from the trachea in experimental animals. Disturbances in the microcirculation of the lung acini were manifested by a sharp increase in blood filling of the microvessels and expansion of their lumen. In this case, the process of erythrocyte penetration into the lumen of the alveoli was sometimes noted. The results of histochemical detection of collagen indicate that in the lung tissue of experimental animals there is no activation of fibrogenetic processes, which would be accompanied by a simultaneous increase in the specific density of collagen. Indicators characterizing the lung tissue (number of cells, their specific density) made it possible to evaluate the corresponding correlations. At the same time, they were not associated with the level of collagen or erythrocyte density in the studied loci of the respiratory system of experimental sexually immature rats. A significant increase in the specific density of erythrocyte mass in lung tissue did not depend on the duration of the experiment. Removal of the ligature and restoration of the tracheal lumen did not significantly affect the restoration of alveolar acini and the spectrum of identified cells. In addition, an increase in the specific density of lung tissue was observed. Conclusion. The findings of this study contribute to deeper understanding of lung damage in children with laryngomalacia and associated respiratory system ventilation impairment. The observed reactive changes in lung connective tissue and collagen synthesis during hypoxia do not necessarily indicate the development of respiratory system fibrosis. However, longer exposure to hypoxic conditions may increase the risk of fibrosis in children.

NSUN2 affects diabetic retinopathy progression by regulating MUC1 expression through RNA m5C methylation

BackgroundDiabetic retinopathy (DR) is the leading cause of blinding eye disease among working adults and is primarily attributed to the excessive proliferation of microvessels, which leads to vitreous hemorrhage and retinal traction, thereby significantly impairing patient vision. NSUN2-mediated RNA m5C methylation is implicated in various diseases, and in this investigation, we focused on elucidating the impact of NSUN2 on the regulation of the expression of the downstream gene MUC1, specifically through RNA m5C methylation, on the progression of DR.MethodUtilizing Microarray analysis, we examined patient vitreous fluid to pinpoint potential therapeutic targets for DR. Differential expression of NSUN2 was validated through qRT-PCR, Western blot, and immunofluorescence in human tissue, animal tissue, and cell model of DR. The relationship between NSUN2 and DR was explored in vitro and in vivo through gene knockdown and overexpression. Various techniques, such as MeRIP-qPCR and dot blot, were applied to reveal the downstream targets and mechanism of action of NSUN2.ResultsThe levels of both NSUN2 and RNA m5C methylation were significantly elevated in the DR model. Knockdown of NSUN2 mitigated DR lesion formation both in vitro and in vivo. Mechanistically, NSUN2 promoted MUC1 expression by binding to the RNA m5C reader ALYREF. Knockdown of ALYREF resulted in DR lesion alterations similar to those observed with NSUN2 knockdown. Moreover, MUC1 overexpression successfully reversed a series of DR alterations induced by NSUN2 silencing.ConclusionsNSUN2 regulates the expression of MUC1 through ALYREF-mediated RNA m5C methylation, thereby regulating the progression of DR and providing a new option for the treatment of DR in the future.

High-performance liquid chromatography determination of polyamine contents in poultry based on precolumn benzoyl chloride derivatization

Polyamines are widely present in animal cells and perform important physiological and biochemical functions. Moderate intake of polyamines contributes to good health. Poultry is one of the common sources of polyamines in daily life. However, different tissues from poultry contain different amounts of polyamine. In this study, an efficient and accurate method for the determination of polyamines was developed by high-performance liquid chromatography (HPLC) with precolumn benzoyl chloride derivatization. The linearity of the polyamines was good between 10–400 nmol/mL, with the limit of detection (LOD, S/N = 3) and limits of quantification (LOQ, S/N = 10) were 0.37 and 1.23 nmol/mL. The recoveries of the method ranged from 94.73 % to 106.58 % with high accuracy (RSD < 7 %) and no significant matrix effects or interferences. The RSD of intra-day, inter-day and inter-batch repeatability in the range of 0.07–1.57 %, 0.08–1.03 % and 1.46–4.57 %. The method was successfully used to detect polyamines in poultry tissue, with putrescine, spermidine and spermine levels ranging from 3.24 to 29.85 mg/kg, 0.46 to 164.11 mg/kg and 63.39 to 489.57 mg/kg, respectively. Polyamine levels were higher in the spleen, thymus and bursa of fabricius and lower in the heart and muscle. Furthermore, the method was employed to study the effect of exogenous spermine on polyamine deposition in different tissues of geese. In summary, the method is suitable for the detection of polyamine in animal tissues.

Identifying the stability of housekeeping genes to be used for the quantitative real-time PCR normalization in retinal tissue of streptozotocin-induced diabetic rats.

To investigate the stability of the seven housekeeping genes: beta-actin (ActB), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), 18s ribosomal unit 5 (18s), cyclophilin A (CycA), hypoxanthine-guanine phosphoribosyl transferase (HPRT), ribosomal protein large P0 (36B4) and terminal uridylyl transferase 1 (U6) in the diabetic retinal tissue of rat model. The expression of these seven genes in rat retinal tissues was determined using real-time quantitative reverse transcription polymerase chain reaction (RT-qPCR) in two groups; normal control rats and streptozotocin-induced diabetic rats. The stability analysis of gene expression was investigated using geNorm, NormFinder, BestKeeper, and comparative delta-Ct (ΔCt) algorithms. The 36B4 gene was stably expressed in the retinal tissues of normal control animals; however, it was less stable in diabetic retinas. The 18s gene was expressed consistently in both normal control and diabetic rats' retinal tissue. That this gene was the best reference for data normalisation in RT-qPCR studies that used the retinal tissue of streptozotocin-induced diabetic rats. Furthermore, there was no ideal gene stably expressed for use in all experimental settings. Identifying relevant genes is a need for achieving RT-qPCR validity and reliability and must be appropriately achieved based on a specific experimental setting.

Form, function, mind: What doesn't compute (and what might)

The applicability of computational and dynamical systems models to organisms is scrutinized, using examples from developmental biology and cognition. Developmental morphogenesis is dependent on the inherent material properties of developing animal (metazoan) tissues, a non-computational modality, but cell differentiation, which utilizes chromatin-based revisable memory banks and program-like function-calling, via the developmental gene co-expression system unique to the metazoans, has a quasi-computational basis. Multi-attractor dynamical models are argued to be misapplied to global properties of development, and it is suggested that along with computationalism, classic forms of dynamicism are similarly unsuitable to accounting for cognitive phenomena. Proposals are made for treating brains and other nervous tissues as novel forms of excitable matter with inherent properties which enable the intensification of cell-based basal cognition capabilities present throughout the tree of life. Finally, some connections are drawn between the viewpoint described here and active inference models of cognition, such as the Free Energy Principle.

METHOD VALIDATION FOR DETERMINATION OF KYNURENIC ACID CONTENT IN NATURAL PRODUCTS BY RP-HPLC-UV

Kynurenic acid (KYNA) is a metabolite with pharmacoactive properties found primarily in chestnut honey, linden, and other honeys. Considering the anti-inflammatory and immunosuppressive functions of KYNA, it can be seen that it has bidirectional effects on biological pathways. For this reason, determining and knowing the amount of honey, an important natural product can have a high impact on health. Studies on the detection of this metabolite in both natural products and animal tissues are ongoing, and it is important to develop fast and easily applicable methods. Within the scope of this study, a new method was created using an ultraviolet detector (RP-HPLC-UV) in reverse-phase high-performance liquid chromatography to determine the KYNA content of natural products (honey, chestnut pollen, and chestnut flowers) quantitatively in a short time. According to the data obtained, LOD and LOQ values were found to be 0.030 µg/mL and 0.092 µg/mL, respectively. At the same time, solutions of KYNA prepared in ultrapure water (UPW), 70% EtOH, EtOH and MeOH solvents were analyzed in this method, and it was found that UPW was the best solvent. The findings of this research can contribute significantly, particularly in the application of measuring KYNA, to distinguishing the botanical origin of chestnut honey.