Tissue Storage Research Articles

Impact of Storage on In Vitro Permeation and Mucoadhesion Setup Experiments Using Swine Nasal Mucosa.

Intranasal topical administration offers a promising route for local and systemic drug delivery, with in vitro permeation and mucoadhesion studies often using porcine models. However, the impact of storage on mucosal integrity after the procedure remains unaddressed. This study aimed to standardize the preparation process and evaluated whether storage of porcine nasal mucosa impairs its integrity and permeability for experimental comparisons. Additionally, an optimized in vitro mucoadhesion experiment using texture analyzer equipment was investigated. Porcine nasal mucosa was subjected to different storage conditions ("fresh"; refrigerated at 4°C for 24h and 48h, and frozen at -20°C for two or three weeks) and assessed using optical and transmission electron microscopy. In vitro permeation assays were performed in a Franz-type vertical diffusion system with lidocaine hydrochloride (LDC). In vitro mucoadhesion assays were conducted using fresh nasal mucosa and a commercial nasal topical formulation using TA.XT. Plus texture analyzer. The variables involved (probe speed, contact time, and application force) in assessing mucoadhesive capacity (maximum mucoadhesive force Fmax and work of mucoadhesion Wmuc) were optimized using a Central Composite Design. Fresh tissues showed no alterations in histological arrangement or in the ultrastructure of adherence junctions. Stored tissues exhibited histological disorganization, reduced thickness, and loss of epithelial integrity. LDC permeability increased in storage tissues (p < 0.05). Contact force had a positive effect on Fmax and Wmuc (p < 0.0001), with a minimum required value of 0.48 N. Variations in contact time and probe speed did not affect the responses (p > 0.05). In conclusion, the preparation technique was adequate to maintain mucosa integrity for permeability studies. However, storing the mucosa at 4 or -20°C overestimated LDC permeation, which could mislead critical data for formulation development. Therefore, the use of fresh mucosa is recommended to ensure more reliable results. For in vitro mucoadhesion assays, a minimum contact force of 0.48N is required for optimal responses.

Carbohydrate storage in cells: a laboratory activity for the assessment of glycogen stores in biological tissues.

Carbohydrates and fats constitute our primary energy sources. The importance of each of these energy substrates varies across cell types and physiological conditions. For example, the brain normally relies almost exclusively on glucose oxidation, whereas skeletal muscle shifts from lipids toward higher carbohydrate oxidation rates as exercise intensity increases. Understanding how carbohydrates are stored in our cells and which tissues contain significant carbohydrate stores is crucial for health professionals, especially given the role of carbohydrate metabolism in various pathophysiological conditions. This laboratory activity uses a simple and low-cost iodine binding method to quantify glycogen in mouse skeletal muscle and liver samples. By integrating the results of this activity with literature data, students can determine overall glycogen storage in the human body. The primary goal of the activity is to enhance students' understanding of the importance and limitations of glycogen stores in energy metabolism.NEW & NOTEWORTHY Carbohydrates are one of the primary energy sources utilized by our cells. Liver and skeletal muscle glycogen, which are the main carbohydrate reserves in the body, play a central role in energy metabolism, especially during periods of fasting and exercise. In this laboratory activity, students measure glycogen levels in tissues to gain insights into how carbohydrates are stored in our cells and understand the role and limitations of liver and muscle carbohydrate stores.

Obesity and Depression: Common Link and Possible Targets.

Depression is among the main causes of disability, and its protracted manifestations could make it even harder to treat metabolic diseases. Obesity is linked to episodes of depression, which is closely correlated to abdominal adiposity and impaired food quality. The present review is aimed at studying possible links between obesity and depression along with targets to disrupt it. Research output in Pubmed and Scopus were referred for writing this manuscript. Obesity and depression are related, with the greater propensity of depressed people to gain weight, resulting in poor dietary decisions and a sedentary lifestyle. Adipokines, which include adiponectin, resistin, and leptin are secretory products of the adipose tissue. These adipokines are now being studied to learn more about the connection underlying obesity and depression. Ghrelin, a gut hormone, controls both obesity and depression. Additionally, elevated ghrelin levels result in anxiolytic and antidepressant-like effects. The gut microbiota influences the metabolic functionalities of a person, like caloric processing from indigestible nutritional compounds and storage in fatty tissue, that exposes an individual to obesity, and gut microorganisms might connect to the CNS through interconnecting pathways, including neurological, endocrine, and immunological signalling systems. The alteration of brain activity caused by gut bacteria has been related to depressive episodes. Monoamines, including dopamine, serotonin, and norepinephrine, have been widely believed to have a function in emotions and appetite control. Emotional signals stimulate arcuate neurons in the hypothalamus that are directly implicated in mood regulation and eating. The peptide hormone GLP-1(glucagon-like peptide- 1) seems to have a beneficial role as a medical regulator of defective neuroinflammation, neurogenesis, synaptic dysfunction, and neurotransmitter secretion discrepancy in the depressive brain. The gut microbiota might have its action in mood and cognition regulation, in addition to its traditional involvement in GI function regulation. This review addressed the concept that obesity-related low-grade mild inflammation in the brain contributes to chronic depression and cognitive impairments.

The Mechanisms of Cadmium Toxicity in Living Organisms

Cadmium (Cd) is a toxic metal primarily found as a by-product of zinc production. Cd was a proven carcinogen, and exposure to this metal has been linked to various adverse health effects, which were first reported in the mid-19th century and thoroughly investigated by the 20th century. The toxicokinetics and dynamics of Cd reveal its propensity for long biological retention and predominant storage in soft tissues. Until the 1950s, Cd pollution was caused by industrial activities, whereas nowadays, the main source is phosphate fertilizers, which strongly contaminate soil and water and affect human health and ecosystems. Cd enters the human body mainly through ingestion and inhalation, with food and tobacco smoke being the primary sources. It accumulates in various organs, particularly the kidney and liver, and is known to cause severe health problems, including renal dysfunction, bone diseases, cardiovascular problems, and many others. On a cellular level, Cd disrupts numerous biological processes, inducing oxidative stress generation and DNA damage. This comprehensive review explores Cd pollution, accumulation, distribution, and biological impacts on bacteria, fungi, edible mushrooms, plants, animals, and humans on a molecular level. Molecular aspects of carcinogenesis, apoptosis, autophagy, specific gene expression, stress protein synthesis, and ROS formation caused by Cd were discussed as well. This paper also summarizes how Cd is removed from contaminated environments and the human body.

Effects of Resveratrol on Adipocytes: Evidence from In Vitro and In Vivo Studies.

Obesity, a prevalent global health issue, arises from an imbalance between caloric intake and energy expenditure, leading to the expansion of adipose tissue and metabolic dysfunction. White adipose tissue (WAT) stores energy as lipids, while brown adipose tissue (BAT) plays a pivotal role in energy dissipation through adaptive thermogenesis. Recent research initiatives have focused on finding strategies to decrease adipogenesis and fat mass accumulation and increase thermogenesis. Finding chemicals with anti-obesity properties would be beneficial. Resveratrol, a polyphenolic compound abundantly found in the skin of grapes and red wine, possesses anti-oxidant, anti-inflammatory, anti-cancer, and anti-obesity properties. This literature review examines the effects of resveratrol on adipocytes in culture and adipose tissue in animal models of obesity. The existing evidence indicates that resveratrol may exert its anti-obesity effects by inhibiting adipogenesis, promoting the apoptosis of mature adipocytes, reducing lipid accumulation, and increasing thermogenesis. Further research utilizing animal and clinical studies is required to understand in detail the anti-obesity potential of resveratrol.

Molecular and cellular mechanisms of mitochondria transfer in models of central nervous system disease.

In the central nervous system (CNS), neuronal function and dysfunction are critically dependent on mitochondrial integrity and activity. In damaged or diseased brains, mitochondrial dysfunction reduces adenosine triphosphate (ATP) levels and impairs ATP-dependent neural firing and neurotransmitter dynamics. Restoring mitochondrial capacity to generate ATP may be fundamental in restoring neuronal function. Recent studies in animals and humans have demonstrated that endogenous mitochondria may be released into the extracellular environment and transported or exchanged between cells in the CNS. Under pathological conditions in the CNS, intercellular mitochondria transfer contributes to new classes of signaling and multifunctional cellular activities, thereby triggering deleterious effects or promoting beneficial responses. Therefore, to take full advantage of the beneficial effects of mitochondria, it may be useful to transplant healthy and viable mitochondria into damaged tissues. In this review, we describe recent findings on the mechanisms of mitochondria transfer and provide an overview of experimental methodologies, including tissue sourcing, mitochondrial isolation, storage, and modification, aimed at optimizing mitochondria transplantation therapy for CNS disorders. Additionally, we examine the clinical relevance and potential strategies for the therapeutic application of mitochondria transplantation.

The addition of 5-aminolevulinic acid to HBSS protects testis grafts during hypothermic transportation: a novel preservation strategy.

The aim of this investigation was to determine the optimal storage medium for testicular hypothermic transportation and identify the ideal concentration for the application of the protective agent 5-aminolevulinic acid (5-ALA). Furthermore, this study aimed to explore the underlying mechanism of the protective effects of 5-ALA. First, we collected and stored mouse testicular fragments in different media, including Hank's balanced salt solution (HBSS; n = 5), Dulbecco's Modified Eagle Medium/Nutrient Mixture F-12 (DMEM/F12; n = 5), and alpha-minimum essential medium (αMEM; n = 5). Storage of testicular tissue in HBSS preserved the integrity of testicular morphology better than that in the DMEM/F12 group (P < 0.05) and the αMEM group (P < 0.01). Testicular fragments were subsequently placed in HBSS with various concentrations of 5-ALA (0 [control], 1 mmol l-1, 2 mmol l-1, and 5 mmol l-1) to determine the most effective concentration of 5-ALA. The 2 mmol l-1 5-ALA group (n = 3) presented the highest positive rate of spermatogonial stem cells compared with those in the control, 1 mmol l-1, and 5 mmol l-1 5-ALA groups. Finally, the tissue fragments were preserved in HBSS with control (n = 3) and 2 mmol l-1 5-ALA (n = 3) under low-temperature conditions. A comparative analysis was performed against fresh testes (n = 3) to elucidate the underlying mechanism of 5-ALA. Gene set enrichment analysis (GSEA) for WikiPathways revealed that the p38 mitogen-activated protein kinase (MAPK) signaling pathway was downregulated in the 2 mmol l-1 5-ALA group compared with that in the control group (normalized enrichment score [NES] = -1.57, false discovery rate [FDR] = 0.229, and P = 0.019). In conclusion, these data suggest that using 2 mmol l-1 5-ALA in HBSS effectively protected the viability of spermatogonial stem cells upon hypothermic transportation.

Quantification and histochemical localization of secondary metabolites during development in Annona muricata L. (Annonaceae)

Histolocalization and quantification of secondary metabolites established the occurrence of alkaloids, phenols and acetogenins in various plant organs of A. muricata at different stages of plant growth.Annona muricata L. possesses broad assemblage of ethno-pharmaceutical and therapeutic upsides ascribed to biosynthesis of secondary metabolites. Currently, the bioactivity is characterized by the production of acetogenins (ACGs), and also by the biosynthesis of alkaloids, primarily benzylisoquinolines derived from tyrosine and phenolic compounds. As a result of high variability of metabolite production in A. muricata, the present study evaluated the histochemical analysis of various plant parts at different developmental stages of growth. Presences of phytometabolites were determined using in-situ histochemical localization of alkaloids, phenolic compounds and acetogenins, while its estimation employing spectroscopic quantification techniques to understand structure, development, time-course deposition, content and distribution of secondary phytoconstituents. Study revealed distinct presence of secondary metabolites in cells and tissues of all plant organs in various intensities and patterns. Alkaloids and acetogenins occurred mostly in secretory cavities or idioblast cells while sparsely associated with other cells or tissues. Phenolic compounds emerged widely, with no confined distribution patterns occurring in storage cells and tissues. Quantitative analysis revealed highest accumulation of alkaloids, phenols and acetogenins in mature root-barks, mature unripe fruit rind and mature leaf respectively. Secondary metabolites generally occurred in young stages at low concentrations as compared to matured growth stages of plant parts. Such in-situ histochemical and biochemical approach will help in identifying the cells and tissues responsible for synthesis, storage and biological effects of potential secondary metabolites which could be further used for culturing and enhancing its production with biotechnological aids.

Does succulence in woody plants delay desiccation, and is stored water used to maintain physiological function during drought conditions?

Succulence is a trait that describes water storage in plant organs and tissues regardless of life form. Plants use the stored water to maintain physiological function and delay desiccation. However, it is unclear whether succulence in leaves, stems and roots of woody plants delays desiccation, whether it provides 'utilizable water' to maintain physiological function, or buffers changes in water status in drying soils through capacitance. We conducted a pot dry-down experiment with nine shrub species to determine whether woody plants with greater leaf, stem, or root succulence have greater shoot utilizable water or capacitance. We also investigated whether greater succulence delays desiccation, represented by cumulative VPD, until evapotranspiration ceased or until utilizable water was exhausted. Greater leaf and stem succulence were strongly related to greater shoot utilizable water and capacitance. However, desiccation time was not delayed in plants with greater total shoot succulence, utilizable water, or capacitance. Instead, woody plants with greater root succulence had longer desiccation times. This suggests that woody plants use aboveground succulence to maintain physiological function and water status during drought, whereas root succulence extends desiccation time. Our study improves the mechanistic understanding of how woody plants use stored water to survive in dryland ecosystems.

Metabolic rewiring in fat-depleted Drosophila reveals triglyceride:glycogen crosstalk and identifies cDIP as a new regulator of energy metabolism.

Tissues store excess nutrients as triglyceride or glycogen, but how these reserves are sensed and communicate remains poorly understood. Here we identify molecular players orchestrating this metabolic balance during fat depletion. We show fat body (FB)-specific depletion of fatty acyl-CoA synthase FASN1 in Drosophila causes near-complete fat loss and metabolic remodeling that dramatically elevates glycogen storage and carbohydrate metabolism. Proteomics and metabolomics identify key factors necessary for rewiring including glycolysis enzymes and target-of-brain-insulin (tobi). FASN1-deficient flies are viable but starvation sensitive, oxidatively stressed, and infertile. We also identify CG10824/cDIP as upregulated in FASN1-depleted Drosophila. cDIP is a leucine-rich-repeat protein with homology to secreted adipokines that fine-tune energy signaling, and is required for fly development in the absence of FASN1. Collectively, we show fat-depleted Drosophila rewire their metabolism to complete development, and identify cDIP as a putative new cytokine that signals fat insufficiency and may regulate energy homeostasis.

Targeting Sodium in Heart Failure.

A dominant event determining the course of heart failure (HF) includes the disruption of the delicate sodium (Na+) and water balance leading to (Na+) and water retention and edema formation. Although incomplete decongestion adversely affects outcomes, it is unknown whether interventions directly targeting (Na+), such as strict dietary (Na+) restriction, intravenous hypertonic saline, and diuretics, reverse this effect. As a result, it is imperative to implement (Na+)-targeting interventions in selected HF patients with established congestion on top of quadruple therapy with angiotensin receptor neprilysin inhibitor, β-adrenergic receptor blocker, mineralocorticoid receptor antagonist, and sodium glucose cotransporter 2 inhibitor, which dramatically improves outcomes. The limited effectiveness of (Na+)-targeting treatments may be partly due to the fact that the current metrics of HF severity have a limited capacity of foreseeing and averting episodes of congestion and guiding (Na+)-targeting treatments, which often leads to dysnatremias, adversely affecting outcomes. Recent evidence suggests that spot urinary sodium measurements may be used as a guide to monitor (Na+)-targeting interventions both in chronic and acute HF. Further, the classical (2)-compartment model of (Na+) storage has been displaced by the (3)-compartment model emphasizing the non-osmotic accumulation of (Na+), chiefly in the skin. 23(Na+) magnetic resonance imaging (MRI) enables the accurate and reliable quantification of tissue (Na+). Another promising approach enabling tissue (Na+) monitoring is based on wearable devices employing ion-selective electrodes for electrolyte detection, including (Na+) and (Cl-). Undoubtably, further studies using 23(Na+)-MRI technology and wearable sensors are required to learn more about the clinical significance of tissue (Na+) storage and (Na+)-related mechanisms of morbidity and mortality in HF.

Carotenoid-carbohydrate crosstalk: evidence for genetic and physiological interactions in storage tissues across crop species.

Carotenoids play essential roles in photosynthesis, photoprotection, and human health. Efforts to increase carotenoid content in several staple crops have been successful through both conventional selection and genetic engineering methods. Interestingly, in some cases, altering carotenoid content has had unexpected effects on other aspects of plant metabolism, impacting traits like sugar content, dry matter percentage, fatty acid content, stress tolerance, and phytohormone concentrations. Studies across several diverse crop species have identified negative correlations between carotenoid and starch contents, as well as positive correlations between carotenoids and soluble sugars. Collectively, these reports suggest a metabolic interaction between carotenoids and carbohydrates. We synthesize evidence pointing to four hypothesized mechanisms: (1) direct competition for precursors; (2) physical interactions in plastids; (3) influences of sugar or apocarotenoid signaling networks; and (4) nonmechanistic population or statistical sources of correlations. Though the carotenoid biosynthesis pathway is well understood, the regulation and interactions of carotenoids, especially in nonphotosynthetic tissues, remain unclear. This topic represents an underexplored interplay between primary and secondary metabolism where further research is needed.

Bone Marrow and Metabolic Bone Disease.

The bone marrow represents one of the largest organs in the body, with a relevant metabolic role that continues to be investigated. Numerous studies have focused on marrow adipose tissue (MAT). Evidence indicates that the bone marrow adipocytes do not only work as storage tissue but also consist of endocrine and paracrine cells, with the potential to contribute to local and systemic metabolism. MAT plays a role in bone health through its interaction with the other components of bone. Many metabolic disorders (osteoporosis, obesity, diabetes) have a complex and still not well-established or understood relationship with bone health. This article surveys the literature on the relationship of bone marrow and metabolic disorders, and how it is being studied using imaging techniques, with a special focus on bone health.

Importance of ferritin research in clinical practice

Serum ferritin (SF) is typically present in serum at concentrations directly related to iron (Fe) storage and is therefore traditionally used as an indicator of Fe levels in body tissues. Reducing its level is the “gold standard” for diagnosing widespread iron deficiency conditions. No less significant is hyperferritinemia — a nonspecific syndrome that occurs when Fe reserves are overloaded, a number of immunoinflammatory, infectious, oncological diseases, liver diseases, etc. In many pathological conditions, the level of SF determines the severity and prognosis of the disease. Ferritin concentrations greater than 1000 ng/mL, regardless of cause, have been shown to be associated with higher mortality. The reason for the increase in the level of SF in liver pathologies (cancer, hepatitis, cirrhosis) is associated with the process of its release from hepatocytes during their destruction. On the other hand, excessive synthesis and/or cellular secretion of ferritin occurs under the influence of various stimuli (cytokines, oxidative stress, hypoxia, oncogenes and growth factors). The interpretation of elevated ferritin values goes far beyond the role of an indicator of replenishment of Fe stores in tissues. Only 10% of cases of hyperferritinemia are associated with iron overload; in most patients, it is defined as the result of the acute phase and a reactive increase in ferritin levels against the background of any disease. The variety of symptoms of iron deficiency syndromes and hyperferritinemia is due to the involvement of many organs and systems, which requires a thorough examination (study of complaints, anamnesis, family and concomitant diseases, as well as the necessary laboratory and instrumental studies) to search for possible causes. Systemic Fe homeostasis must be closely monitored on a regular basis. It is required to comply with the conditions for blood sampling for SF. Reference values for SF concentrations vary depending on the analytical methods used and the population studied. Age and gender play an important role. Given the range of reference values, it is important for a particular patient to focus on the initial level of his ferritin, determined against the background of health and well-being during clinical observation.

Лицензирование изъятия и хранения органов и (или) тканей человека для трансплантации: правовые проблемы и решения.

The article examines the problem of licensing medical activities related to the removal and storage of human organs and (or) tissues for transplantation purposes in medical organizations that are donor bases. It is proposed to understand donor bases as medical organizations in which or on the basis of which the collection and procurement of human organs and (or) tissues is carried out for the purpose of their subsequent transplantation in medical organizations that directly carry out transplantation of human organs and (or) tissues. The authors show legal gaps in the current legislation, which lead to difficulties in licensing these types of activities for both licensing authorities and medical organizations. A rationale for possible ways to solve these problems is presented and specific proposals for amending current legislation are presented.

Development of mRNA Lipid Nanoparticles: Targeting and Therapeutic Aspects.

Lipid nanoparticles (LNPs) have emerged as leading non-viral carriers for messenger RNA (mRNA) delivery in clinical applications. Overcoming challenges in safe and effective mRNA delivery to target tissues and cells, along with controlling release from the delivery vehicle, remains pivotal in mRNA-based therapies. This review elucidates the structure of LNPs, the mechanism for mRNA delivery, and the targeted delivery of LNPs to various cells and tissues, including leukocytes, T-cells, dendritic cells, Kupffer cells, hepatic endothelial cells, and hepatic and extrahepatic tissues. Here, we discuss the applications of mRNA-LNP vaccines for the prevention of infectious diseases and for the treatment of cancer and various genetic diseases. Although challenges remain in terms of delivery efficiency, specific tissue targeting, toxicity, and storage stability, mRNA-LNP technology holds extensive potential for the treatment of diseases.

Plasma Endocannabinoids Are Independently Associated With the Metabolic Function of White Adipose Tissue

Abstract Context Little is known about the link between the endocannabinoid (EC) system and the in vivo metabolic function of white adipose tissue (WAT). Objective We aimed to evaluate whether ECs are linked to postprandial fatty acid metabolism and WAT metabolic function. Methods Men and women, with (IGT, n = 20) or without impaired glucose tolerance (NGT, n = 20) underwent meal testing with oral and intravenous stable isotope palmitate tracers and positron emission tomography with intravenous [11C]-palmitate and oral [18F]-fluoro-thia-heptadecanoic acid to determine systemic and organ-specific dietary fatty acid (DFA) and nonesterified fatty acid (NEFA) metabolism and partitioning. We determined fasting and postprandial plasma levels of EC by ultra-high performance liquid chromatography–tandem mass spectrometry. Results All ECs of the 2-monoacylglycerol (2-MAG) family displayed a progressive postprandial increase up to 360 minutes after meal intake that was more pronounced in women with IGT. N-acylethanolamine (NAE) levels decreased between fasting and 180 minutes, followed by a return to preprandial values at 360 minutes and were also increased in women with IGT. Postprandial area under the curve (AUC) of palmitate appearance rate was significantly and independently associated with postprandial AUC of anandamide (AEA; P = .0003) and total energy expenditure (P = .0009). DFA storage in abdominal subcutaneous adipose tissue was positively predicted by fasting 2-arachidonoylglycerol (2-AG; P &amp;lt; .04). Conclusion EC levels of the NAE family independently follow plasma NEFA metabolism, whereas 2-MAG closely follow the spillover of triglyceride-rich lipoprotein intravascular lipolytic products. Whether these associations are causal requires further investigation.

Using a triphasic model to describe the permeation of dimethyl sulfoxide in porcine corneoscleral discs

Corneal blindness can be treated by keratoplasty but a lack of readily available corneal donor tissue for this procedure remains a challenge. Cryopreservation can facilitate the long-term storage of tissue but effective protocols for cryopreserving cornea have yet to be developed. Mathematical modelling can guide protocol design, but previously used models are not comprehensive. A comprehensive model should describe the tissue's shrink−swell response and the cryoprotectant concentration throughout the tissue during cryoprotectant loading. Such a model exists for articular cartilage based on a biomechanical triphasic approach. We explored the applicability of this model for describing cryoprotectant permeation in porcine corneas by fitting it to experimental data for the permeation of dimethyl sulfoxide into porcine corneoscleral discs. The model provided as good of a fit for corneoscleral discs data as it did for articular cartilage data, presenting promise for its use in the design of cryopreservation protocols for corneas.

19 Strategies to optimize the trace mineral status of weaned beef calves

Abstract Trace mineral nutrition of pre-weaned beef calves is derived from 1) tissue stores at birth, 2) milk, 3) forage, and 4) supplement. In most production systems, calves are born with adequate trace mineral status, namely Cu, Zn, Mn and Se. One exception, however, is severe Se deficiency in the dam which may result in White Muscle Disease in Se-deficient calves shortly after birth. Despite general adequacy at birth, tissue concentrations of these elements often decrease during the pre-weaning period due to inadequacies in milk and trace mineral deficiency of forages. Trace mineral losses are further exacerbated by a variety of stressors naturally occurring throughout the production system, including, but not limited to, environmental, social, and immunological. Weaning, which is unavoidable in modern production systems, is the most stressful experience a beef animal will experience in their lifetime. To avoid deficiency at weaning, trace mineral deficits must be addressed through supplementation during the pre-weaning period. One of the most common supplementation methods involves the blending of supplemental trace minerals with common salt, offered free choice. This system assumes that cattle have a “nutritional wisdom” to consume salt at a level that meets their requirement for Na. Although largely effective in most grazing situations, this management system is not without complications. Notably, salt-based, free-choice mineral supplements are offered simultaneously to cow/calf pairs with known variation in voluntary intake. The necessity to understand and manage free-choice intake is the basic principle behind all successful free-choice mineral supplementation systems. In tropical and subtropical climates, where a large percentage of the world’s beef is produced, cattle are typically enrolled in year-long grazing schedules that are characterized by dry and wet seasons. In these environments, the craving for salt increases as forage DM decreases resulting in large seasonally impacted reductions in voluntary intake of salt-based, free-choice mineral supplements. During the dry season, when forage moisture is low, free-choice, salt-based mineral consumption often does not meet anticipated target levels due to a reduced natural craving for salt. There are other examples where seasonal variation in salt craving impacts the effectiveness of targeting appropriate voluntary intake of free-choice mineral supplements. For example, in some coastal regions of the world, salt-water intrusion will impact the Na content of forages and drinking water. In these regions, cattle may avoid salt-fortified supplements because of excessive Na intake from other sources. Fortunately, if we understand these regional and climatic impacts, there are effective management interventions that may be adopted to protect against trace mineral deficiency resulting from inadequate free-choice intake. This symposium presentation will review multiple pre-weaning mineral supplementation systems that have been shown to be effective for optimizing the mineral status of weaned beef calves.

Integrated insights into the cytological, histochemical, and cell wall composition features of Espinosa nothofagi (Hymenoptera) gall tissues: implications for functionality.

Many insect-induced galls are considered complex structures due to their tissue compartmentalization and multiple roles performed by them. The current study investigates the complex interaction between Nothofagus obliqua host plant and the hymenopteran gall-inducer Espinosa nothofagi, focusing on cell wall properties and cytological features. The E. nothofagi galls present an inner cortex with nutritive and storage tissues, as well as outer cortex with epidermis, chlorenchyma, and water-storing parenchyma. The water-storing parenchyma cells are rich in pectins, heteromannans, and xyloglucans in their walls, and have large vacuoles. Homogalacturonans contribute to water retention, and periplasmic spaces function as additional water reservoirs. Nutritive storage cell walls support nutrient storage, with plasmodesmata facilitating nutrient mobilization crucial for larval nutrition. Their primary and sometimes thick secondary cell walls support structural integrity and act as a carbon reserve. The absent labeling of non-cellulosic epitopes indicates a predominantly cellulosic nature in nutritive cell walls, facilitating larval access to lipid, protein, and reducing sugar-rich contents. The nutritive tissue, with functional chloroplasts and high metabolism-related organelles, displays signs of self-sufficiency, emphasizing its role in larval nutrition and cellular maintenance. Overall, the intricate cell wall composition in E. nothofagi galls showcases adaptations for water storage, nutrient mobilization, and larval nutrition, contributing significantly to our understanding of plant-insect interactions.