Changes In Different Organs Research Articles

Preclinical assessment of a recombinant RBD-Fc fusion protein as SARS-CoV-2 candidate vaccine.

Waning immunity and emergence of new variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), highlight the need for further research in vaccine development. A recombinant fusion protein containing the receptor-binding domain (RBD) fused to the human IgG1 Fc (RBD-Fc) was produced in CHO-K1 cells. RBD-Fc was emulsified with four adjuvants to evaluate its immunogenicity. The RBD-specific humoral and cellular immune responses were assessed by ELISA. The virus neutralizing potency of the vaccine was investigated using four neutralization methods. Safety was studied in mice and rabbits, and Antibody-Dependent Enhancement (ADE) effects were investigated by flow cytometry. RBD-Fc emulsified in Alum induced a high titer of anti-RBD antibodies with remarkable efficacy in neutralizing both pseudotyped and live SARS-CoV-2 Delta variant. The neutralization potency dropped significantly in response to the Omicron variant. RBD-Fc induced both TH2 and particularly TH1 immune responses. Histopathologic examinations demonstrated no substantial pathologic changes in different organs. No changes in serum biochemical and hematologic parameters were observed. ADE effect was not observed following immunization with RBD-Fc. RBD-Fc elicits highly robust neutralizing antibodies and cellular immune responses, with no adverse effects. Therefore, it could be considered a promising and safe subunit vaccine against SARS-CoV-2.

Histopathologic changes in different organs during mycobacteriosis in guppy (Poecilia reticulata) and japanese medaka (Oryzias latipes)

Total histological sections of laboratory fish Poecilia reticulata and Oryzias latipes with pronounced multiple organ failure caused by Mycobacterium infection (Mycobacterium sp.) were analyzed. The pathogenesis of the disease in question is expressed in the occurrence, in various tissues, of foci of inflammation, subsequently forming a connective tissue capsule — granuloma. These lesions were observed in almost all organs of the abdominal cavity of the fish. The largest and most common lesions were found in the pancreas, kidneys and liver (from 478.6 microns to 858.4 microns), significantly disrupting organ functions, which is a clinical picture characteristic of mycobacteriosis. The occurrence of granulomas and their average sizes in organs such as the intestine and gills were significantly lower and amounted to 328.3 and 468.9 microns, respectively. Data on the stages of granuloma development in different organs of fish are presented. The initial stage of granuloma development consists of clusters of macrophage-like cells, lymphocytes, granulocytes and a small number of cellular residues. At the final stage of development, it is a focus, including an eosinophilic-stained caseous-necrotic nucleus and a shell consisting of epithelioid macrophages. It is shown that there is a relationship between the size parameters of granulomas, the frequency of their occurrence and the degree of organ damage. The localization of granulomas and the degree of their development in guppies and medaka were similar, indicating the absence of species-specific virulence. It follows from this that any warm-water fish species cultivated under controlled conditions are at risk. This requires monitoring for signs of disease and regular preventive measures.

Effect of Blend of Metanil Yellow and Tartrazine on Different Organs of Albino Rat

Background: Tartrazine and metanil yellow are organic azo dyes widely used in food products, drugs, and cosmetics. The present study was conducted to evaluate the toxic effect of these food colors on the liver, and kidneys of albino rats. The study also evaluates the protective effect of quercetin as an antioxidant against the toxic effect of these food colors. Methods: Eighty adult albino rats were divided into 8 groups. Control group, 3 groups were treated with a blend of tartrazine and metanil yellow in 3 doses of 25, 50, and 75 mg/kg for 30 days by gavage, one positive control group was treated with quercetin 50 mg/kg for 30 days, and three groups were treated with the blend of tartrazine and metanil yellow plus 50 mg/kg of quercetin. At the end of the experiment, serum samples were collected to evaluate liver and kidney functions. Liver, kidney samples were fixed in 10% formalin and routinely prepared for paraffin sectioning and staining for histopathological examination. Results: The study showed a significant elevation of liver and kidney function after treatment with the food color blend. Also, a significant improvement in liver and kidney function was observed after treatment with quercetin. Histopathological examination showed mild to moderate changes in the liver and kidney which improved after quercetin treatment. Conclusion: The current sub-chronic study concluded that a blend of tartrazine and metanil yellow caused significant biochemical and histological changes in different organs of albino rats. Therefore, prolonged consumption of these substances leads to adverse effects on human health. Also, quercetin is vital in protecting the body against the toxic effects of food color blends.

Seroprevalence and molecular detection of infectious laryngotracheitis virus (ILTV) in commercial chicken in Gazipur district of Bangladesh

Infectious laryngotracheitis (ILT) is one of the major diseases of chickens that cause great economic losses in commercial chicken farms. It is caused by the infectious laryngotracheitis virus (ILTV). This research work was designed to investigate the seroprevalence of ILTV in commercial chicken farms in Gazipur district. A total of 590 blood sera were collected randomly from commercial chicken farms from different locations in Gazipur district. An antigen-coated indirect ELISA was performed to determine the antibody titer against ILTV in these sera. Moreover, gross and histopathological changes in different organs were investigated. Polymerase chain reaction (PCR), a molecular detection method, was performed to detect the fragment of the glycoprotein ‘C’ (gC) gene of ILTV in the infected chicken. Overall, 195 out of 590 serum samples were positive for anti-ILTV IgG, representing 33.05% of positive cases. The highest mean titer of ILTV antibody was found in anti-ILTV-vaccinated layer chickens with a mean titer of 3554. In seasonal variation, the highest prevalence of ILTV was recorded during the winter, followed by the rainy and summer seasons. The prevalence of ILTV was the highest at the age of 10-30 weeks in layer chickens. Necropsy findings of dead chickens showed severe congestion and fibrosis in the lungs and trachea, with occlusion of the tracheal lumen by mucus, caseous exudates and blood. Microscopically, hemorrhage and huge infiltrations of inflammatory cells were found in trachea and lungs. Moreover, the nucleotide sequence of ‘gC’ gene of ILTV was amplified successfully and yielded 1.26 kbp amplicons. This study suggested that ILTV was endemic in Gazipur district and the PCR technique is a useful molecular tool for diagnosis of ILTV in the commercial chicken industry. Ann. Bangladesh Agric. (2023) 27 (1): 121-135

Extracellular vesicles from human urine-derived stem cells delay aging through the transfer of PLAU and TIMP1

Aging increases the risks of various diseases and the vulnerability to death. Cellular senescence is a hallmark of aging that contributes greatly to aging and aging-related diseases. This study demonstrates that extracellular vesicles from human urine-derived stem cells (USC-EVs) efficiently inhibit cellular senescence in vitro and in vivo. The intravenous injection of USC-EVs improves cognitive function, increases physical fitness and bone quality, and alleviates aging-related structural changes in different organs of senescence-accelerated mice and natural aging mice. The anti-aging effects of USC-EVs are not obviously affected by the USC donors’ ages, genders, or health status. Proteomic analysis reveals that USC-EVs are enriched with plasminogen activator urokinase (PLAU) and tissue inhibitor of metalloproteinases 1 (TIMP1). These two proteins contribute importantly to the anti-senescent effects of USC-EVs associated with the inhibition of matrix metalloproteinases, cyclin-dependent kinase inhibitor 2A (P16INK4a), and cyclin-dependent kinase inhibitor 1A (P21cip1). These findings suggest a great potential of autologous USC-EVs as a promising anti-aging agent by transferring PLAU and TIMP1 proteins.

Biochemical Changes of Dexamethasone on Liver and Kidney Functions in Laboratory Mice Mus musculus L.

Background: The present study sought to verify the effect of dexamethasone on the biochemical changes in different organs, such as liver and kidney organs of both sexes, male and female mice. Materials & Method: Muc muscular males and female mice (n=48) were used. To determine the effects of dexamethasone on the biochemical changes of liver and kidney organs, mice received a low dose (2mg/kg) and a high dose (4 mg/kg) of dexamethasone continuously for one month. Result: The results showed a significant increase (P<0.05) in Liver enzymes (ALP, AST, ALT). The urea and creatinine levels also increased in the treated mice and both sexes with the pesticide compared with the control group. Keywords: mice, histological, liver, kidney, dexamethasone, toxicity

Distinguishing the Cellular Transport of Folic Acid Conjugated Nano-Drugs among Different Cell Lines by Using Force Tracing Technique

Folic acid (FA) is a ligand that has been renowned for its strong binding to FA receptor (FR), and the robustness of the specific interaction has led to the generation of multitudinous tumor-targeted nano-drug delivery systems. However, selecting the appropriate FA targeted nano-drugs according to types of cancerous cells to achieve a high effect is critical. Understanding of how the drug is transported through the cell membrane and is delivered intracellularly is very important in screening ideal targeted nano-drugs for cancerous changes in different organs. Herein, by using a force tracing technique based on atomic force microscopy (AFM), the dynamic process of FA-polyamidoamine-Doxorubicin (FA-PAMAM-DOX) entry into different tumor cells (HeLa and A549) and normal cells (Vero) was monitored in real time. The cell membrane transport efficacy of FA-PAMAM-DOX in tumor cells with an FR high overexpression level (HeLa) and FR low overexpression level (A549) is analyzed, which is significantly higher than that in normal cells (Vero), especially for HeLa cells. Subsequently, the intracellular delivery efficiency of FA-PAMAM-DOX in different cell lines was measured by using fluorescence imaging and AFM-based nanoindentation techniques. This report will help to discover the cellular transport mechanism of nano-drugs and screen out optimal therapeutic nano-drugs for different types of tumors.

Histopathological autopsy findings in lungs of pregnant and postpartum women who died of COVID-19 infections.

The coronavirus disease 2019 outbreak (COVID-19) caused by the SARS-CoV coronavirus, has been declared as apandemic by the World Health Organization on 11March 2020, as aresult of which about 315,000,000 people all over the world have been infected and more than 5,000,000 died. Many scientific articles have been published concerning histopathological changes in different organs, but data concerning the lung changes of pregnant and postpartum period women who died of COVID-19 infections are still scarce. The aim of our study was to review and summarize autopsy findings and histopathological changes in lungs of pregnant and postpartum period women who died of COVID-19 infections in Armenia during 2020-2021. Lung tissue specimens of 14pregnant and postpartum period women who died of COVID-19 infections and its complications were examined. Hematoxylin-eosin and van Gieson staining methods as well as immunohistochemical examinations were used. The average age of the dead women was33.9 years. From 14cases in 9there were comorbidities. All cases of death were in the 2ndand 3rdtrimester of pregnancy or early and late postpartum period. Forensic medical diagnosis included COVID-19 infection with bilateral polysegmented pneumonia and acute respiratory failure. Histopathological examination revealed diffuse alveolar damage of lungs (DAD) in predominantly proliferation/organizing stage. Histopathological examination of lungs showed proliferative stage of DAD with signs of fibrosing pneumonia. Early diagnosis and hospitalization of pregnant women may prevent late complications of COVID-19 infection and fibrosing pneumonia development, as well as future risks of fatal outcomes in pregnant and early postpartum period.

Safety evaluation and whole genome sequencing for revealing the ability of Penicillium oxalicum WX-209 to safely and effectively degrade citrus segments

The microbial potential of Penicillium has received critical attention. The present research aimed to elucidate the efficacy of crude enzyme secreted from Penicillium oxalicum WX-209 in degrading citrus segments and evaluate the safety of the process. Results showed that citrus segment membranes gradually dissolved after treatment with the crude enzyme solution, indicating good degradation capability. No significant differences in body weight, food ingestion rate, hematology, blood biochemistry, and weight changes of different organs were found between the enzyme intake and control groups. Serial experiments showed that the crude enzyme had high biological safety. Moreover, the whole genome of P. oxalicum WX-209 was sequenced by PacBio and Illumina platforms. Twenty-five scaffolds were assembled to generate 36 Mbp size of genome sequence comprising 11 369 predicted genes modeled with a GC content of 48.33 %. A total of 592 genes were annotated to encode enzymes related to carbohydrates, and some degradation enzyme genes were identified in strain P. oxalicum WX-209. Data availabilityThe whole genome sequencing data in this study can be found in GenBank database of NCBI website with the accession number PRJNA 715321. The link: http://www.ncbi.nlm.nih.gov/bioproject/715321.

High-fat diet causes mitochondrial damage and downregulation of mitofusin-2 and optic atrophy-1 in multiple organs.

High-fat consumption promotes the development of obesity, which is associated with various chronic illnesses. Mitochondria are the energy factories of eukaryotic cells, maintaining self-stability through a fine-tuned quality-control network. In the present study, we evaluated high-fat diet (HFD)-induced changes in mitochondrial ultrastructure and dynamics protein expression in multiple organs. C57BL/6J male mice were fed HFD or normal diet (ND) for 24 weeks. Compared with ND-fed mice, HFD-fed mice exhibited increased body weight, cardiomyocyte enlargement, pulmonary fibrosis, hepatic steatosis, renal and splenic structural abnormalities. The cellular apoptosis of the heart, liver, and kidney increased. Cellular lipid droplet deposition and mitochondrial deformations were observed. The proteins related to mitochondrial biogenesis (TFAM), fission (DRP1), autophagy (LC3 and LC3-II: LC3-I ratio), and mitophagy (PINK1) presented different changes in different organs. The mitochondrial fusion regulators mitofusin-2 (MFN2) and optic atrophy-1 (OPA1) were consistently downregulated in multiple organs, even the spleen. TOMM20 and ATP5A protein were enhanced in the heart, skeletal muscle, and spleen, and attenuated in the kidney. These results indicated that high-fat feeding caused pathological changes in multiple organs, accompanied by mitochondrial ultrastructural damage, and MFN2 and OPA1 downregulation. The mitochondrial fusion proteins may become promising targets and/or markers for treating metabolic disease.

A study on the morbid histopathological changes in COVID-19 patients with or without comorbidities using minimally invasive tissue sampling.

COVID-19 causes morbid pathological changes in different organs including lungs, kidneys, liver, and so on, especially in those who succumb. Though clinical outcomes in those with comorbidities are known to be different from those without-not much is known about the differences at the histopathological level.To compare the morbid histopathological changes in COVID-19 patients between those who were immunocompromised (Gr 1), had a malignancy (Gr 2), or had cardiometabolic conditions (hypertension, diabetes, or coronary artery disease) (Gr 3),postmortem tissue sampling (minimally invasive tissue sampling [MITS]) was done from the lungs, kidney, heart, and liver using a biopsy gun within 2 hoursof death. Routine (hematoxylin and eosin) and special staining (acid fast bacilli, silver methanamine, periodic acid schiff) was done besides immunohistochemistry.A total of 100 patients underwent MITS and data of 92 patients were included (immunocompromised: 27, malignancy: 18, cardiometabolic conditions: 71). In lung histopathology, capillary congestion was more in those with malignancy, while others like diffuse alveolar damage, microthrombi, pneumocyte hyperplasia, and so on,were equally distributed. In liver histopathology, architectural distortion was significantly different in immunocompromised; while steatosis, portal inflammation, Kupffer cell hypertrophy, and confluent necrosis were equally distributed. There was a trend towards higher acute tubular injury in those with cardiometabolic conditions as compared to the other groups. No significant histopathological difference in the heart was discerned.Certain histopathological features were markedly different in different groups (Gr 1, 2, and 3) of COVID-19 patients with fatal outcomes.

Assessment of Pristine Carbon Nanotubes Toxicity in Rodent Models

Carbon nanotubes are increasingly used in nanomedicine and material chemistry research, mostly because of their small size over a large surface area. Due to their properties, they are very attractive candidates for use in medicine and as drug carriers, contrast agents, biological platforms, and so forth. Carbon nanotubes (CNTs) may affect many organs, directly or indirectly, so there is a need for toxic effects evaluation. The main mechanisms of toxicity include oxidative stress, inflammation, the ability to damage DNA and cell membrane, as well as necrosis and apoptosis. The research concerning CNTs focuses on different animal models, functionalization, ways of administration, concentrations, times of exposure, and a variety of properties, which have a significant effect on toxicity. The impact of pristine CNTs on toxicity in rodent models is being increasingly studied. However, it is immensely difficult to compare obtained results since there are no standardized tests. This review summarizes the toxicity issues of pristine CNTs in rodent models, as they are often the preferred model for human disease studies, in different organ systems, while considering the various factors that affect them. Regardless, the results showed that the majority of toxicological studies using rodent models revealed some toxic effects. Even with different properties, carbon nanotubes were able to generate inflammation, fibrosis, or biochemical changes in different organs. The problem is that there are only a small amount of long-term toxicity studies, which makes it impossible to obtain a good understanding of later effects. This article will give a greater overview of the situation on toxicity in many organs. It will allow researchers to look at the toxicity of carbon nanotubes in a broader context and help to identify studies that are missing to properly assess toxicity.

Micro-expression spotting based on optical flow features

• The nose tip location-based image alignment method improves the performance of Micro-expression spotting. • The optical flow method can accurately capture micro-expression movements. • When a micro-expression occurs, a peak appears on the time-domain change curve. • Get complete micro-expression intervals after fusing local movements. Expression is the changes of facial organs due to facial muscle movement and an important way of human emotional interaction. Neurophysiological studies show that micro-expressions (MEs) are not controlled by subjective consciousness and reflect people's real emotions. That is why MEs have significant value in public security applications. This paper proposes an automatic ME spotting method of high accuracy and interpretability. Firstly, we design the nose tip location-based image alignment method to remove global displacement caused by head shaking. Secondly, according to the action unit definition in the face coding system (FACS), we select fourteen regions of interest (ROI) to capture subtle facial movements. The dense optical flow is introduced to estimate local movements and time-domain variations of the ROIs. Thirdly, we design a peak detection method on the time-domain variation curves to locate the movement intervals precisely. Lastly, we propose an overlapping index to measure the consistency of changes in different organs. Evaluation on the CAS(ME) 2 and SAMM Long Video database shows that our ME spotting method may achieve better accuracy with a relatively lower computation cost and can be applied to similar facial image processing applications.

Chronic kidney disease and comorbid diseases of gastrointestinal tract

Nowadays the patient more often has a comorbid pathology. The combinations of two or more chronic diseases, which are either pathologically interlaced or exist simultaneously, may worsen the case of each individual disease. Kidney diseases are often associated with gastrointestinal disorders, cardiovascular and endocrine diseases, because of the same immunological features of etiology and pathogenesis. Chronic kidney disease (CKD) requires correction of lifestyle and implementation of control over the physical development in children from the first stages of the disease. CKD C4-C5 leads to unbalance in homeostasis and to increased level of toxic substances in blood, that is why doctors can see changes in different organs and systems especially in gastrointestinal tract. The urinary system and the gastrointestinal tract have a common plan of structure, functioning and regulation. It determines the general mechanisms of etiology and pathogenesis. There is a direct correlation between the stage of CKD and the damage level of the gastrointestinal system. This article covers the pathophysiological mechanisms of digestive system damage in advanced stages of CKD. Special attention is paid to changes in microbiota of the gastrointestinal tract. In turn, it affects to systemic inflammation, which is an aggravating factor in course of the CKD and its progression. The emphasis is made on involvement of the gastrointestinal tract in varying degrees in children with CKD C4-C5.

The ameliorative efficacy of Thymus vulgaris essential oil against Escherichia coli O157:H7-induced hematological alterations, hepatorenal dysfunction and immune-inflammatory disturbances in experimentally infected rats.

The purpose of the present study was to evaluate the possible ameliorative role of Thymus vulgaris (T. vulgaris) essential oil against Escherichia coli O157:H7 (E. coli O157:H7) deleterious effects in both blood and different tissues of rats by assessing the hematological, biochemical and immune-inflammatory parameters besides the histopathological alterations in the different organs. Forty male rats were randomly divided into four equal groups as follows: group I served as control, group II orally inoculated with E. coli O157:H7 at a dose of 1.0 × 109cfu/ml, group III orally received 250mg/kg BW T. vulgaris oil daily for 7days and group IV orally inoculated with E. coli O157:H7 as the same dose of group II and orally received T. vulgaris oil as the same dose and duration of group III. Bacterial challenge in groups II and IV was once at the beginning of experiment and administration of oil began after 72h from bacterial inoculation. At the end of the study, blood was sampled and complete blood picture, liver and kidney function alongside immunoglobulins and cytokines concentrations were estimated and tissues of large intestine (colon), liver and kidneys were collected for histopathological examinations. The results revealed that there was an increase of red blood cells count, hematocrit value and hemoglobin concentration besides white blood cells and thrombocytes counts and substantial increment of serum markers of hepatorenal damage such as the activities of transaminases and concentrations of bilirubin (total, direct and indirect), total proteins, albumin, creatinine and urea in E. coli O157:H7-challenged group. Also, there was a considerable increase in serum immunoglobulins M and G, interleukin 6 and 8 and tumor necrosis factor alpha as well as decreased serum alkaline phosphatase activity. Moreover, T. vulgaris oil could partially improve the hematological, biochemical and histopathological alterations induced by E. coli O157:H7 without any significant alterations in all measured parameters when used alone. The study concluded that the T. vulgaris oil relatively diminished the alterations in hematological parameters, hepatic and renal function markers and immune-inflammatory variables alongside the histopathological changes in different organs induced by E. coli O157:H7. The ameliorative effects of T. vulgaris oil are mediated through its anti-inflammatory, antioxidant and immunomodulatory activities.

Proton density fat fraction: magnetic resonance imaging applications beyond the liver.

Magnetic resonance imaging-proton density fat fraction (MRI-PDFF) is an emerging quantitative imaging biomarker that accurately measures the fat fraction of tissue by correcting factors influencing magnetic resonance signal intensity. Beyond fat quantification, it also measures R2* which is a direct measure of iron concentration. The utilization of MRI-PDFF in liver diseases is well established. In the present review, we focused on applications of MRI-PDFF in different body areas including pancreas, bone, muscle, spleen, testis, visceral, and subcutaneous adipose tissue. Future studies can enable tracking of quantitative fat fraction changes in different organs simultaneously, which can be critical in understanding fat metabolism.

CUBIC-plus: An optimized method for rapid tissue clearing and decolorization

Advanced CUBIC clearing method can clear diverse organs and even the entire body of a mouse to enable high-resolution 3D imaging. Advanced CUBIC reagent has often been used due to its low toxicity and easy preparation. However, Advanced CUBIC has a long experimental cycle, which reduces the efficiency of data acquisition. In this study, we first tracked the clarity changes of different organs cleared by Advanced CUBIC and identified the shortest time required for optimal transparency in individual organs. We then introduced ultrasound processing and developed a decolorization cocktail to optimize the clearing efficiency of the Advanced CUBIC method. With the optimized clearing CUBIC-Plus method, we achieved high resolution 3D imaging of mouse organs. Our CUBIC-Plus provides an efficient procedure to clear different organ for 3D imaging at high resolution.

Repeated dose treatment of Tinospora cordifolia polysaccharide rich extract activates splenic antigen presenting cells with no associated organ toxicity

Tinospora cordifolia is a medically valuable plant widely used in Ayurveda and has been attributed with immunomodulatory properties. We compared the immunomodulation of repeated doses of the purified polysaccharide G1-4A and polysaccharide-rich extract (PRE) of T. cordifolia in BALB/c mice. Since both had comparable effects, we further compared the repeated dose effects of 50 and 500 mg/kg b.w PRE per dose with particular emphasis on histological changes in different organs, splenic cell death and DNA damage and immunomodulation. In mice treated with both concentrations of PRE, no gross changes were observed in any organ by histopathological analyses along with normal biochemical parameters similar to control. There was no increase in splenic lymphocyte cell death or DNA damage. A significant increase in the number of splenic macrophages with no increase in phagocytosis was observed. Increased expression of phenotypic maturation markers was observed in splenic dendritic cells and not in bone marrow-derived dendritic cells of PRE-treated mice. Increased activation of B cells in response to mitogen with no change in such a response by T cells was also observed. These results from repeated dose experiments indicate that PRE treatment has no associated organ toxicity and activates antigen-presenting cells and thus can be used instead of G1-4A as a promising immunotherapeutic adjuvant.

Microplastics induced histopathological lesions in some tissues of tilapia (Oreochromis niloticus) early juveniles

Although microplastics (MPs) have received increasing focus and currently have become an emerging area of research, there is limited knowledge about their effect on whole body histology of fish. In this study, tilapia (Oreochromis niloticus) early juveniles were exposed to 1, 10, or 100 mg/L of MPs for 15 days and 15 days post-exposure, after which whole body histological examinations were performed. Histological analysis of kidney revealed congestion of blood capillaries, inflammatory cells, loss of basophilic cytoplasm in several tubules, vacuolated tubules, shrinking of convoluted tubules, widening of intertubular space, complete deformation, glomerular atrophy, vacuolated glomerular cells, and signs of fatty tubules. The liver tissue exhibited vacuoles, hydropic degeneration, necrotic area, severe deformation of hepatocytes, pyknotic nuclei, and dilation and congestion of blood sinusoids. The pancreatic tissue revealed shrunken and degenerated acini with pyknotic nuclei, hemorrhage, necrotic area, inflammatory cells, fatty cells, and congested blood capillaries. In the muscle tissue, fiber core dissociation, edema, necrosis, segmented fibers, and inflammatory cells were detected. The gill tissue demonstrated dilation and congestion of blood vessels, complete lamellar fusions, lifting of epithelium, shortening and degeneration of secondary lamellae, hyperplasia, and deposition of MPs between primary lamellae. In the spinal cord and notochord, the effects were degeneration and protrusion of meninges, deformation and deviation of notochord from its central axis, edema, degeneration of notochord (disappearance of vacuolar cells), deviation of spinal cord from the central axis, and loss of vacuolar cells in notochord. The intestinal tissue exhibited degeneration of basement membrane, inflammatory cells, goblet cells, atrophy of submucosa, pyknotic nuclei, hemorrhage, and vacuolization of mucosal cells. The histopathological changes in different organs were noticed even post-exposure in fish exposed to MPs compared to those in control fish and these changes were concentration dependent. In conclusion, these data together with our previous data suggest that MPs can cause different changes, ranging from biochemical alterations in single cells to lesions in the entire tissue, which can affect the vitality and life of fish.

Life Without Thyroid Hormone Receptor.

Thyroid hormone (T3) is critical not only for organ function and metabolism in the adult but also for animal development. This is particularly true during the neonatal period when T3 levels are high in mammals. Many processes during this postembryonic developmental period resemble those during amphibian metamorphosis. Anuran metamorphosis is perhaps the most dramatic developmental process controlled by T3 and affects essentially all organs/tissues, often in an organ autonomous manner. This offers a unique opportunity to study how T3 regulates vertebrate development. Earlier transgenic studies in the pseudo-tetraploid anuran Xenopus laevis revealed that T3 receptors (TRs) are necessary and sufficient for mediating the effects of T3 during metamorphosis. Recent gene knockout studies with gene-editing technologies in the highly related diploid anuran Xenopus tropicalis showed, surprisingly, that TRs are not required for most metamorphic transformations, although tadpoles lacking TRs are stalled at the climax of metamorphosis and eventually die. Analyses of the changes in different organs suggest that removal of TRs enables premature development of many adult tissues, likely due to de-repression of T3-inducible genes, while preventing the degeneration of tadpole-specific tissues, which is possibly responsible for the eventual lethality. Comparison with findings in TR knockout mice suggests both conservation and divergence in TR functions, with the latter likely due to the greatly reduced need, if any, to remove embryo/prenatal-specific tissues during mammalian postembryonic development.