Histochemical Studies Research Articles

Venous intestinal ischemia of fungal origin as a cause of intestinal obstruction in immunocompromised patients: case report and literature review

BackgroundMucormycosis is a highly lethal opportunistic fungal disease caused by ubiquitous molds of the order Mucorales, with Rhizopus, Lichtheimia and Mucor being the most common genera. This rare disease primarily affects immunocompromised patients, with presentations ranging from rhino-orbito-cerebral infections to disseminated mucormycosis with angioinvasion, leading to thrombosis and tissue infarction. Gastrointestinal mucormycosis is the least common clinical presentation and is believed to be secondary to spore ingestion. It can involve multiple components of the gastrointestinal tract, such as the stomach, liver, ileum, and colon, with nonspecific manifestations, including pain, nausea, vomiting, and abdominal distension. The initial clinical presentation may even manifest as gastrointestinal bleeding due to gastric ulceration or intestinal perforation.Case presentationHere we present the case of a 48-year-old male patient with a 9-year history of human immunodeficiency virus (HIV) infection who was hospitalized in the context of febrile neutropenia and whose acute respiratory infection was documented; therefore, antibiotic treatment was initiated. However, due to persistent febrile peaks and peripheral blood showing documentation of multilineage cytopenias, a bone marrow biopsy was performed, compatible with presenting features of marrow myelodysplasia. During hospitalization, the patient presented left flank abdominal pain, and an abdominal computed tomography (CT) scan revealed signs of intussusception of a small bowel loop at the distal jejunum level, leading to intestinal obstruction with ischemic progression, requiring ileectomy (60 cm). Histopathological analysis of the resected intestine revealed severe transmural ischemic changes associated with venous thrombosis due to fungal structures, with histochemical studies demonstrating the presence of zygomycete (Mucor) fungal structures, leading to the initiation of treatment with amphotericin B. However, despite treatment, the patient experienced progressive clinical deterioration with persistent fever and ventilatory failure, with follow-up tests showing absolute neutropenia and blood cultures positive for yeast, leading to death 52 days after admission.ConclusionsThe diagnosis of intestinal mucormycosis may be delayed due to the lack of specificity of the signs and symptoms. Pathologists as well as histopathological studies are essential for timely treatment.

Effect of vitamin-mineral complex with probiotic on histological structure of gastrointestinal tract tissues of budgerigars

Purpose: to evaluate the effect of a vitamin-mineral complex with a probiotic on the histological structure of the gastrointestinal tract tissues of budgerigars in dynamics.Materials and methods. The object of the study were budgerigars aged from 60 to 180 days. According to the principle of pairs-analogues, 3 experimental and a control group of 20 birds each were formed from clinically healthy budgerigars. For the purpose of the experiment, complete granules were created containing a basic grain-seed diet and a complex consisting of a probiotic, vitamins and minerals. Bacillus Subtillis 5 mg per 100 g of live weight was used as a probiotic. For histological and histochemical studies, tissue pieces measuring 0.5 x 0.5 x 0.5 cm were selected. In each section, an assessment of at least 10 fields of vision was given.Results. As a result of the experiment, lasting 45 days, a gradual increase in the probiotic mass was noted in the gastrointestinal tract of budgerigars on the 15th and 30th day. Complete release of the body from the probiotic was observed on the 30th day after stopping the administration of the granulated complex. No changes in the histological structure of the liver were revealed. Positive changes in the intestine and stomach were noted, such as an increase in the density of villi and the height of the epithelium, folds, crypts and tubular glands. These changes are reversible, due to the temporary effect of the vitamin and mineral complex with a probiotic.

Seasonal and diurnal variations in leaf aroma volatiles of Cinnamomum tamala (Buch.-Ham.) T. Nees & Eberm as evidenced from metabolite profiling, histochemical and ultrastructural analyses.

Though the leaves of Cinnamomum tamala is extensively employed in culinary applications due to its rich aroma and therapeutic properties, the produce exhibits variability in composition and contents of leaf essential oil due to fluctuations in climatic conditions and harvesting time. This work evaluated the impact of seasonal and diurnal variations on the composition and contents of aroma volatiles in the mature leaves of C. tamala. In summer, the profile of aroma volatile was dominated by phenylpropanoids (112.96±24.11μg/g of freeze-dried leaf tissue) while in winter monoterpenes (58.45±8.194μg/g of freeze-dried leaf tissue) acquired the dominance. The variability in the contents of primary metabolites was shown to be influenced by the harvesting season and time. Organic acids and sugars showed highest accumulation in leaves harvested during summer evening and winter morning, respectively. Histochemical study showed the presence of lipids and terpenes in the secretory cells as revealed through sudan III and NaDi staining. The ontogeny of secretory oil cells that accumulate essential oil were elucidated through ultrastructural study.

Spectral lights influence growth and metabolic efficiency leading to enhanced phytochemical contents of Coriandrum sativum L.

Coriandrum sativum. L (coriander) is an aromatic herb containing valuable bioactive compounds. The current study aimed to understand the role of light quality influence on the metabolic performance of C. sativum. The study was conducted by integrating LED lights viz. red (100 R:0B), red: blue (50 R:50B); blue (0 R:100B), and warm white (WW, served as control). The fresh and dry biomass was highest under 0 R:100B spectral LED lights, whereas the photosynthetic performance was maximum under 50 R:50B LED lights. Among the major vitamins studied, ascorbic acid content was maximized under 50 R:50B spectral LED lights, while α-tocopherol content was highest under 0 R:100B light conditions. Luteolin and umbelliferone, the detected coumarins, exhibited their highest levels under 50 R:50B light spectral composition, however, chlorogenic acid demonstrated its maximum level under 0 R:100B spectral LED lights. C. sativum plants grown under 50 R:50B light displayed a relatively higher content of volatile compounds including, decanal, 2-decenal, 2,6,11-trimethyldodecane, 2-dodecenal, and (E)-tetradec-2-enal. Glucose, fructose, and sucrose identified as the major primary metabolites, were highest under 50 R:50B light. Moreover, the stem and leaf anatomy exhibited the greatest vascularization when influenced by 50 R:50B and 0 R:100B spectral LED lights. Histochemical studies further revealed an intense accumulation of metabolites under the 50 R:50B spectral light conditions. The study also demonstrated the influence of light quality on chloroplast ultrastructure, influencing starch accumulation and providing insights into plant cell metabolic activity through the observed association of chloroplasts with mitochondria. Taken together, the study suggests that 50 R:50B spectral combination could play an important role in augmenting the metabolic performance and phytonutrient outcomes of C. sativum.

Comparative Morphological and Histochemical Study of Esophagus, in Eurasian Collared Dove (Streptoplia decaocto) and Buzzard (Beuteo beuteo vulpinus)

The study carried out on 28 esophagus specimens of healthy, 14 Eurasian Collared Dove (Streptoplia decaocto) and 14 Buzzard (Beuteo beuteo vulpinus). The aimed, to study the esophagus's morphological also histological. The lumen of esophagus in dove appear narrower and shorter in length than Buzzard as well as the crop as well-developed sac , while the crop in buzzard as longitudinal narrow spindle dilation ,and the present research work was done on the histology and histochemistry of the esophagus in dove and buzzard and found that the esophagus was composed of three segment cervical, crop and thoracic ,histologically, the mucosa of cervical, thoracic part was lined by non-keratinized layer of stratified squamous cells. As well as The esophageal glands were absent in cervical part and crop in dove, whereas in the thoracic part these glands were present and their duct open toward the lumen of the esophagus. The mucosal folds well developed in the cervical portion. Histochemically, the epithelium gland of esophagus showed PAS positive reaction that indicated presence of neutral mucopolysaccharides, the esophageal glands showed strong moderate reaction by (PAS)in cervical and thoracic esophagus as well as in thoracic part in dove. Conclusion the results showed that esophagus was significantly different Morphological and histological between two birds.

Green Synthesis of Silver Nanoparticles from Abelmoschus esculentus (Okra) Calyx Wastes as a Promising Anthelmintic Agent Against Poultry Pathogen Raillietina spp.

AbstractIn this study, we explore the synthesis of silver nanoparticles (AgNPs) using calyx wastes from Abelmoschus esculentus (okra) and evaluate their anthelmintic potential against poultry pathogen Raillietina spp. The ultraviolet‐visible (UV‐vis) spectrum of nanoparticles showed an absorbance peak at 425 nm, confirming AgNP formation. Fourier transform infrared spectrophotometry (FTIR) analysis indicated the presence of functional groups responsible for reducing silver ions, and X‐ray diffraction (XRD) patterns confirmed the crystallinity of the nanoparticles. Dynamic light scattering (DLS), scanning and transmission electron microscopy (SEM and TEM) analyses were used to measure the size (20–50 nm) and morphology (spherical) of the synthesized AgNPs. The dose‐dependent in vitro anthelmintic efficacy was highest at 125 μg/ml of AgNPs, resulting in paralysis and death within 0.54 and 1.29 hours, respectively, while untreated control parasites survived for ~72 hours. The SEM micrographs of the treated parasites showed swelling and blebbing of the tegument. Histochemical localization studies showed a remarkable decline of tegumental and neurotransmitter enzymes involved with the parasite's metabolism and regulation of the endogenous physiological processes. This study underscores the potential of okra calyces in the green synthesis of AgNPs and provides a novel approach to developing alternative anthelmintics that interfere with the host‐parasite interface.

Laminin Beta 2 Is Localized at the Sites of Blood-Brain Barrier and Its Disruption Is Associated With Increased Vascular Permeability, Histochemical, and Transcriptomic Study.

Heterotrimeric extracellular matrix proteins laminins are mostly deposited at basal membranes and are important in repair and neoplasia. Here, we localize laminin beta 2 (LAMB2) at the sites of blood-brain barrier (BBB). Microvasculature (MV) of normal brain is endowed with complete LAMB2 coverage. In contrast, its cognate protein laminin beta 1 (LAMB1) is absent in MV of normal brain but emerges at the sprouting tip of a growing vessels. Similarly, vascular proliferation in high-grade gliomas (HGG) is accompanied by marked overexpression of LAMB1, whereas LAMB2 shows deficient deposition. We find that many brain pathologies with presence of post-gadolinium enhancement (PGE) on magnetic resonance imaging (MRI) show disruption of LAMB2 vascular ensheathment. Inhibition of vascular endothelial growth factor signaling in HGG blocks angiogenesis, suppresses PGE in HGG, prevents expression of LAMB1, and restores LAMB2 vascular coverage. Analysis of single-cell RNA sequencing (scRNA-seq) databases shows that in quiescent brain LAMB2 is predominantly expressed by BBB-associated pericytes (PCs) and endothelial cells (ECs), whereas neither cell types produce LAMB1. In contrast, in HGG, both LAMB1 and 2 are overexpressed by endothelial precursor cells, a phenotypically unique immature group, specific to proliferating hyperplastic MV.

Histological and histochemical study of effect of dietary fibre in motility of stomach in male mice.

To investigate the relationship between dietary fibres and muscularis externa layer. The experimental study was conducted at the Anatomy Department of the College of Medicine, Al- Nahrain University, Iraq, from November 2020 to April 2021, and comprised adult healthy males. They were divided randomly into experimental group A and control group B. Group A was fed high-fibre diet, and group B was fed standard pellet diet. The tissue samples were harvested at day 30 post-surgery. The stomach samplings were placed in 10% neutral formalin for 24 hours to obtain paraffin sections for routine histological and immunohistochemical staining. The protein expression in stomach's smooth muscle of each group was detected by immunohistochemical staining. Data was analysed using SPSS 24. Of the 20 mice, 10(50%) were in each of the two groups. Group A exhibited significant weight-gain compared to group B (p≤0.01). There was significant reduction in the thickness of the muscularis layer in group A compared to group B (p≤0.01). Anoctamin 1 expression in group A was significantly lower than that in group B (p≤0.01). The stress induced by an unstable fibre diet significantly affected the stomach by decreasing the muscularis layer thickness and Anoctamin 1 expression in interstitial cells of Cajal.

Tannin-Rich Fraction of Cyperus esculentus Protects against Lead-Induced Testicular Toxicity in Male Wistar Rats through ITS Antioxidant Properpty

Aims: Lead as a common environmental toxic metal, causes many histological, physiological and biomedical abnormalities in human and animals. This study evaluated the antioxidant potential of tannins on serum level of testosterone, LH and FSH and histology of the testes of male Wistar rats. Materials and Methods: Twenty-five adult male Wistar rats were divided into five (5) groups, (n=5). Group NS was administered normal saline only, Group PBO was administered with 30mg/kg body weight (BW) of lead, group LDTPB was administered with 50 mg/kg BW of tannins and 30mg/kg BW of lead, group MDTPB was administered with 100mg/kg BW of tannins and 30mg/kg BW of lead, group HDTPB was administered 150mg/kg BW of tannins and 30mg/kg BW of lead orally for 28 days. The animals were sacrificed and testes were harvested on day 29 of the experiment and histological and histochemistry studies done using the H&E and VVG staining respectively. Sperm parameters (motility, concentration), sex hormones (Testosterone, LH, FSH) and antioxidant activities were also determined. Results: There was Leydig cell proliferation and an increase series of spermatogenesis of the testes in the rats of groups administered with lead and tannins different doses (LDTPB, MDTPB and HDTPB) when compared with rats administered with lead only. Rats in groups LDTPB, MDTPB and HDTPB had a significant increase in levels of serum testosterone (p<0.05) when compared with positive control group (2). There was increase in levels of FSH in MDTPB and HDTPB groups when compared with positive control (2). Increased MDA levels were observed in the rats given lead only, PBO when compared to NS group. The rats given lead and tannins significant growth of seminiferous epithelium, improved sperm quality, and had decreased MDA levels. Conclusion: This study demonstrated the protective role of tannins fraction of Cyperus esculentus on lead-induced testicular toxicity in male Wistar rats.

The implications of atorvastatin administration and the potential protective role of omega-3 on the submandibular salivary gland of albino rats (Histological, Histochemical, Ultrastructure, and Biochemical Study)

BackgroundHyperlipidemia is a risky condition that can lead to atherosclerosis and other cardiovascular problems. Statins are used to treat hyperlipidemia. The most recommended medicine to treat hyperlipidemia is atorvastatin. On the contrary, clinical trials validated statins' negative effects. Omega-3 fatty acids have antioxidant properties and have been shown to improve a variety of disease processes in the general population, including inflammatory and immunological pathways, various cardiovascular diseases, and lipid regulation. The present research aimed to determine how atorvastatin affected the submandibular salivary gland (SMG) and whether omega-3 may have a protective impact. MethodsThirty adult male albino rats were divided into three equal groups and received drugs orally as a single daily dose for one week. Control group (I): received normal saline. Atorvastatin group (II): received a dose of 80 mg Kg-1 of Atorvastatin. Group III: received Omega-3 before Atorvastatin. All rats were sacrificed 2 h following the last dose, and blood samples were gathered for the biochemical study of fasting blood glucose level (FBGL). Specimens were obtained and processed for histological and histochemical studies. ResultsAtorvastatin-treated rats showed degeneration of SMG acini. The acinar cells showed cytoplasmic vacuoles with dilated RER. Histochemical results revealed a marked decrease in total proteins. The biochemical study revealed an elevation in FBGL. The administration of Omega-3 with Atorvastatin minimizes these changes. ConclusionAtorvastatin has been proven to induce histological changes in SMG, and these changes can be attenuated by Omega-3. However, Omega-3 has no effect on FBGL.

Histological and histochemical studies on the heart of prepubertal and adult local goat

Histological and histochemical studies on the heart of prepubertal and adult local goat

Histochemical and ultrastructural localization of triterpene saponins in Medicago truncatula.

In the Medicago genus, saponins are complex mixtures of triterpene pentacyclic glycosides extensively studied for their different and economically relevant biological and pharmaceutical properties. This research is aimed at determining for the first time the tissue and cellular localization of triterpene saponins in vegetative organs of Medicago truncatula, a model plant species for legumes, by histochemistry and transmission electron microscopy. The results showed that saponins are present mainly in the palisade mesophyll layer of leaves, whereas in stems they are mostly located in the primary phloem and the subepidermal cells of cortical parenchyma. In root tissue, saponins occur in the secondary phloem region. Transmission electron microscopy revealed prominent saponin accumulation within the leaf and stem chloroplasts, while in the roots the saponins are found in the vesicular structures. Our results demonstrate the feasibility of using histochemistry and transmission electron microscopy to localize M. truncatula saponins at tissue and cellular levels and provide important information for further studies on biosynthesis and regulation of valuable bioactive saponins on agronomic relevant Medicago spp., such as alfalfa (Medicago sativa L.). RESEARCH HIGHLIGHTS: The Medicago genus represents a valuable rich source of saponins, one of the most interesting groups of secondary plant metabolites, which possess relevant biological and pharmacological properties. Plant tissue and cellular localization of saponins is of great importance to better understand their biological functions, biosynthetic pathway, and regulatory mechanisms. We elucidate the localization of saponins in Medicago truncatula with histochemical and transmission electron microscopy studies.

Histochemical studies of aroma components in fruits of wild tomato species native to the Peruvian Andes and the Galapagos Islands

Histochemical studies of aroma components in fruits of wild tomato species native to the Peruvian Andes and the Galapagos Islands

The effect of Norethisterone acetate on the uterus of albino rats: histological, histochemical and ultrastructure study

BackgroundNorethisterone acetate (NETA), also known as norethindrone acetate is a progestogens medication that is widely used in birth control pills, menopausal hormone therapy, and for the treatment of gynecological disorders as abnormal uterine bleeding and endometriosis. There is a lack of detailed histological information regarding the effects of NETA on the uterine structure. So, the present study focuses on the uterine histological, histochemical and ultrastructure changes following the exposure to NETA in the albino rats. To do this aim, fourteen adult female albino rats were used. They were randomly divided into two equally groups: Control group and NETA treated group. Albino rats of control group were administered daily food, water and orally distilled water only, while rats of NETA treated group were administered daily orally 20 µg of NETA dissolved in 2 ml distilled water, food, and water. The experiment was continued for three weeks.ResultsThe findings of the present work indicated that the use of NETA has negative effects on the endometrial epithelium (proliferation, autophagy and apoptosis), glands (necrotic, apoptotic or pseudosecretory glands) and stromal and myometrial reactions (granulocytes, connective tissue remodeling, apoptosis, myocytes hypertrophy).ConclusionThis work revealed that NETA has desynchronized progestogenic effect on the uterine tissues of the albino rat and thereby prevent implantation and pregnancy.

Interaction of Capnodium alfenasii with extrafloral nectaries of Azadirachta indica.

Sooty moulds are saprophytic epiphytic fungi that grow mostly on insect secretions, but they can also be associated with plant secretions. In this study, we aimed to describe de interaction of Capnodium alfenasii sooty mould with the extrafloral shoot nectaries of Azadirachta indica. Anatomical and histochemical studies were carried out on serial sections of extrafloral shoot nectaries of A. indica without and with C. alfenasii infestation. The total soluble sugar content of the secreted nectar was determined, and the conidial germination of the fungus in distilled water and in dextrose and nectar solutions was evaluated. The shoot nectaries of A. indica are elongated structures that occur in pairs near the base of the petiole. The exuded nectar contains an average of 534.8µg of total soluble sugars per µL of nectar and provides ideal conditions for conidial germination and fungal growth. C. alfenasii hyphae grow on the nectary, penetrate through breaks in the cuticle, travel under the cuticle and penetrate the secretory tissue by inter- and intracellular routes. The present report is the first to describe the interaction of C. alfenasii with the A. indica nectary, including the penetration of hyphae into nectariferous tissues and the plant defence mechanisms.

New insight in secretory structures and secretion composition in Rhus typhina L. – Anatomical, histochemical, and ultrastructural studies

Rhus typhina is a valuable plant used in the pharmaceutical, cosmetic, and food industries due to the presence of biologically active substances accumulated in its organs, especially in secretory structures, i.e. trichomes and secretory ducts. Light microscopy, scanning electron microscopy, and transmission electron microscopy were used to examine the structure of glandular and non-glandular trichomes, as well as secretory ducts present in inflorescence peduncles of R. typhina. The chemical composition of the secretion produced by trichomes and ducts was assessed using histochemical techniques, including observations under brightfield and fluorescence microscopes. Two types of capitate glandular trichomes producing secretions with a similar composition and non-glandular trichomes exhibiting secretory activity were identified. The secretion of glandular trichomes was dominated by acidic and neutral lipids, essential oil, sesquiterpenes, and steroid-containing terpenes. The schizogenic secretory ducts located in the phloem produced a viscous milky substance with acidic polysaccharides, acidic lipids, phenolic compounds, and proteins. The secretion was released into the duct lumen through notches in the walls of the secretory epithelial cell facing the duct lumen. The location, type, and traits of the non-glandular trichomes and secretory structures, as well as the composition of the secreted products are considered important taxonomic features in the family Anacardiaceae and the Rhus genus. Additionally, these characters are important diagnostic markers for the pharmacobotanical identification of the species in medicinal and cosmetic raw materials. The various compounds present in the secretory structures of R. typhina may contribute to plant protection against pathogens or herbivory and probably play a role as attractants for pollinators and seed dispersers.

Forensic medical characterization of sudden death in young people with connective tissue dysplasia according to the data of the Bureau of Medical Examinations of Moscow City

BACKGROUND: Sudden death is an urgent problem of modern public healthcare, with prevalence in the Russian Federation. The wide range of causes and data scarcity led to the complexity of diagnosis and interpretation of pathologic changes at autopsy. This study presents an epidemiologic analysis of the causes of sudden death in a young population. AIM: To provide a forensic medical description of cases of sudden death of young people with connective tissue dysplasia using data from forensic autopsies conducted at the Bureau of Medical Examinations of the Moscow City Health Department. MATERIALS AND METHODS: A sample study of 48 corpses of young people aged 18–44 years who died suddenly, was performed based on data from the Forensic Medical Examination Bureau of the Moscow Department of Health. The protocols for examining the corpse at the scene of the incident, medical records were analyzed comprehensively. An extended description of the external and internal examinations of corpses was performed, and materials for histological, histochemical, and immunohistochemical studies were collected. RESULTS: Cardiovascular pathologies were the main cause of sudden death in young people. In some cases, an asthenic type was established with the following signs: high stature, elongated chest with an acute epigastric angle, poorly defined subcutaneous fatty tissue, weight less than the age norm, and narrow shoulders. Pathological changes were identified in the sternum, spine, limbs, dental status, and internal organs, which corresponded to connective tissue dysplasia. A correlation was noted between sudden death in young people and asthenic skeletopathy with exposure to extreme factors such as physical stress, psychoemotional stress, and previous infectious diseases. In most cases of sudden death, pathological changes in blood vessels were diagnosed in young people. CONCLUSION: The development of a modern comprehensive scientific and methodological approach is necessary to assess pathomorphological changes in young people who died suddenly.

USE OF PULMONARY METABOLIC FUNCTION INDICATORS AS MARKERS OF ASPHYXIAL DEATH BY HANGING

During forensic examinations to establish the cause of death by asphyxiation in various types of mechanical asphyxiation, especially hanging, the greatest attention is paid to changes in the lungs. Despite the complexity of the genesis of death in mechanical asphyxia, the most common cause of death is asphyxia. Therefore, an important link in the progression of the asphyxia process is its effect on a vital organ such as the lungs. In order to address issues related to the development of pathological changes in the lungs, histochemical studies aimed at detecting markers of mechanical asphyxia are becoming increasingly important, in addition to the generally accepted macro- and micromorphological studies. The aim of the study is to analyse the current research on changes in the lungs during death by mechanical asphyxia due to hanging. Results. When establishing the cause of death with signs of mechanical asphyxia due to hanging, attention is drawn to the macromorphological manifestations of asphyxia genesis in the form of general signs of asphyxia that are not specific to this type of death. However, it has been found that their appearance is associated with the release of a number of biologically active substances into the body, since the process of dying by hanging is a strong stress factor. This is also indicated by micromorphological changes in various organs. The lungs receive the most attention in the study, as they are a crucial link in the asphyxiation process. The lungs are known to perform a number of important non-respiratory functions in addition to their primary function of gas exchange. The lung is an organ of biosynthesis and metabolism of many biologically active substances, regulating their levels in the blood. Some of these substances are released into the bloodstream in pathological conditions and significantly affect metabolic processes both in the lungs and throughout the body. Therefore, such substances can be used as biomarkers to prove the asphyxial genesis of death. Conclusions. Since the course of the asphyxiation process significantly affects the function of the lungs, which are the organ of biosynthesis and metabolism of many biologically active substances, the possibility of using these substances as markers of the asphyxial genesis of death in mechanical asphyxia, especially in hanging, has been demonstrated.

Modulation of the intestinal mucosal and cell-mediated response against natural helminth infection in the African catfish Clarias gariepinus

Fish gut is a versatile organ serving as the primary pathway for invasion by pathogens, particularly parasites, playing a crucial role in modulating the intestinal adaptive immune response. This study aimed to investigate the cellular-mediated reaction, mucosal acidity, and the expression of proliferating cell nuclear antigen (PCNA), vascular endothelial growth factor (VEGF), and CD68 in the intestines of catfish, Clarias gariepinus, naturally infected with helminths. Forty catfish were collected from the Nile River and examined for intestinal parasites. The intestinal tissues of the control and infected fish were fixed for histochemical and immunohistochemical studies. Two groups of helminths were found: cestodes Tetracampos ciliotheca and Polyonchobothrium clarias, and nematodes Paracamallanus cyathopharynx, with a prevalence rate of 63.63%, 18.0%, and 18.0%, respectively. Our results showed that the infected fish had a statistically significant rise in the activity of immune cells, including mast cells, eosinophil granular cells, and dendritic cells. This correlated with upregulation in the expressions of PCNA, VEGF, and CD68. Histochemical analyses demonstrated a marked increase in acidic mucus production, Sudan black B, and bromophenol mercury blue. This study enriches our understanding of the evolution of vertebrate immunity in combating intestinal parasitic infections and the host’s adaptive responses.

Role of Silicon in Counteracting Cadmium Stress in Pea Plants (Pisum sativum L.): Insights Into Cadmium Binding Mechanisms and Pectin Methylesterase Activity

Purpose: The aim of this study was to investigate the role of silicon (Si) in counteracting a cadmium (Cd) stress to pea plants (Pisum sativum L.) and to identify the mechanism by which Cd is bound within pea roots. Methods: These goals were achieved through (i) a histochemical study of Cd localization in pea roots, (ii) spectrophotometric determination of pectin content and the activity of pectin methylesterase (PME), (iii) speciation of Cd extracted from pea roots conducted through size exclusion chromatography (SEC) and inductively coupled plasma mass spectrometry (ICP/MS). Results: Cd was found mainly in the root stele of the Cd-stressed plants. The pectin content and PME activity were lower in the Cd-stressed plants, but Si supplementation reversed these effects. Selectivity was noticed in Cd extraction efficiency with water being the least effective and enzymatic-assisted extraction proving to be the most effective. Speciation analysis revealed significant heterogeneity in molar mass, ranging from approximately 295 to 95 kDa. Galacturonic acid was identified the dominant species responsible for Cd binding. The choice of solvent for extraction markedly influenced the Cd binding profile, indicating shifts in the distribution of species’ molar mass and their relative concentrations in extracts. Conclusions: Si alleviates Cd toxicity in pea plants, and one of the mechanisms through which it operates involves increasing pectin levels and PME activity. Pectin plays an active role in Cd detoxification in the root cell walls, forming electrostatic bonds with Cd cations through its carboxyl groups.