Jorge Gonzalo Farias

The ectosymbiont fauna associated with crustaceans in South American inland waters is characterized by a marked microendemism, as the species concerned appear to show high host specificity. The aim of the present study is to present a review of ciliated Protozoa reported as ectosymbionts on South American inland water malacostracans. The literature revealed the existence of three genera, Chilenophrys with one species, Lagenophrys with five species, and Operculigera with seven species. The main limiting factor is that many species descriptions require further validation, as the reports have not been confirmed. The literature reports the presence of Lagenophrys lenticulata associated with Hyalella curvispina from Uruguay. H. curvispina is widespread throughout southern South America, including Argentina and Chile, and it may be possible to find epibionts on other populations of H. curvispina , as well as on other Hyalella populations. Lagenophrys aegleae has been recorded on the genus Aegla in eastern and western South America; L. antichos on crayfishes in east and west South America; and L. lenticulata on amphipods in North America and Uruguay. Ecological and biogeographical topics are also addressed.

The endocannabinoid system (ECS) represents a vital neurotransmitter network in vertebrates, regulating neurogenesis, cognition, lipid metabolism, and immune activity. One of the vertebrates used for studying the endocannabinoid system is fish, specifically the species Danio rerio, known as zebrafish, due to its similarities with vertebrate development. This review explores the ECS in teleost fishes, emphasising its role in reproductive physiology and its interaction with environmental pollutants. Although extensive research has elucidated the ECS in mammals, limited data exist for teleosts. The literature revealed that endocannabinoids in Teleostei have an essential role in lipid metabolism, with effects revealed mainly in the brain and liver involving gene expression processes that regulate these metabolic pathways. Another key role of the endocannabinoid system in fish is in reproduction, as lipid metabolism directly influences gonadal function. Environmental pollutants, such as bisphenol A and phthalates, also disrupt ECS function, impairing reproductive performance and metabolic stability. These findings underscore the need for further studies on teleost-specific ECS mechanisms and their implications for aquatic ecosystems.

Acute lymphoblastic leukemia (ALL) is the most common cancer affecting children, making up about 80% of all acute leukemia cases in the pediatric population. While treatment with L-asparaginase (ASNase) has greatly improved survival rates, its bacterial origin often causes immune reactions in some patients, which can reduce how well the therapy works. To overcome this challenge, previous in silico studies designed a humanized chimeric ASNase by swapping out the predicted immunogenic parts of the bacterial enzyme with similar, less immunogenic segments from the human version—while keeping the enzyme’s active site intact. In this study, the chimeric L-asparaginase designed was successfully cloned, expressed, and purified using the Escherichia coli Rosetta strain. The production conditions (37 °C, 0.01 mM IPTG, 2–4 h) were optimized, and we purified the enzyme in a single step with nickel-affinity chromatography. The enzyme’s activity was confirmed in vitro, showing that it is possible to produce a functional humanized variant in a bacterial system. These results lay important groundwork for future research to assess the immune response and therapeutic potential of this novel chimeric enzyme.

This study investigated the effects of dietary supplementation with the probiotic Pediococcus acidilactici on the reproductive performance and offspring viability of male Atlantic salmon (Salmo salar). A total of 48 mature males were divided into three groups—Group A (control, no probiotic), Group B (60-day supplementation), and Group C (120-day supplementation). The fish were kept in 10 m³ tanks at a constant temperature of 9 °C under a natural photoperiod and evaluated for multiple reproductive and physiological parameters. The results demonstrate that Group C exhibited significantly higher gonad weight, gonadosomatic index (GSI), and sperm concentration than Groups A and B. The blood biochemistry revealed reduced bilirubin and alanine aminotransferase (ALT) levels in Group C; however, values were within normal reference ranges for the species in all groups. While sperm quality parameters such as membrane integrity and motility showed no significant differences, fertility and embryo viability were significantly higher in Group C across all three developmental stages (180, 300, and 380 accumulated thermal units, ATUs). Additionally, Group C showed lower rates of embryonic malformation and mortality at later stages of development. Statistical analyses confirmed a significant interaction between treatment duration and embryo viability, with the 120-day probiotic treatment (Group C) producing the best outcomes. These findings support the hypothesis that P. acidilactici supplementation positively influences male reproductive parameters and improves embryo quality and survival in Atlantic salmon.

Bone tissue engineering (BTE) emerged as a practical approach to tackle prosthetic industry limitations. We merge aspects from developmental biology, engineering and medicine with the aim to produce fully functional bone tissue. Mesenchymal stem cells have the capability of self-renewal and specific lineage differentiation. Herein lies their potential for BTE. Among MSCs, human dental pulp stem cells have a higher proliferation rate, shorter doubling times, lower cellular senescence, and enhanced osteogenesis than hBM-SCs under specific conditions. In addition, these cells are readily accessible and can be extracted through a subtle extraction procedure. Thus, they garner fewer moral concerns than most MSCs available and embody a promising cell source for BTE therapies able to replace hBM-MSCs. Interestingly, their study has been limited. Conversely, there is a need for their further study to harness their true value in BTE, with special emphasis in the design of bioprocesses able to produce viable, homogenous bone constructs in a clinical scale. Here, we study the osteogenic differentiation of hDPSCs encapsulated in alginate hydrogels under suspended culture in a novel perfusion bioreactor. The system is compared with traditional 3D static and fed-batch culture methodologies. The novel system performed better, producing higher alkaline phosphatase activity, and more homogeneous, dense and functional bone constructs. Additionally, cell constructs produced by the in-house-designed system were richer in mature osteoblast-like and mineralizing osteocyte-like cells. In conclusion, this study reports the development of a novel bioprocess able to produce hDPSC-based bone-like constructs, providing new insights into hDPSCs’ therapeutic potential and a system able to be transferred from the laboratory bench into medical facilities.

L-asparaginase (L-ASNase) is a key enzyme in the treatment of leukemia and lymphoma, with high demand in cancer therapies. Advances in recombinant protein production have improved yields and reduced costs, enabling large-scale production. However, optimizing culture conditions remains crucial for maximizing production. This study focused on optimizing the production of double mutant L-ASNase expressed in Escherichia coli BL21 (DE3) by supplementing media with amino acids. Five amino acids were evaluated at a shake flask scale using the design of experiments, with arginine and aspartate showing the most positive effects. Under optimized conditions (14.5 mM arginine, 12.7 mM aspartate, and 0 mM cysteine), the activity model reached 12,513 U L⁻¹, experimentally validated at 10,089 U L⁻¹. The maximum specific cell growth rate was µ_x,max = 0.74 h⁻¹, with substrate–biomass conversion factor Yx/s = 1.16 g/g and cell–product conversion factor Yp/x = 13,891 U/g_cell. Amino acid supplementation resulted in a ten-fold increase in L-ASNase activity. Finally, at the bioreactor scale, adding amino acids and the inducer at the end of the exponential phase increased activity by 135% compared to conventional MD, demonstrating its potential for industrial-scale production.

Over recent decades, Northern Patagonia in Chile has seen significant growth in agriculture, livestock, forestry, and aquaculture, disrupting lake ecosystems and threatening native species. These environmental changes offer a chance to explore how anthropization impacts zooplankton communities from a molecular–ecological perspective. This study assessed the anthropogenic impact on Daphnia pulex by comparing its proteomes from two lakes: Llanquihue (anthropized) and Icalma (oligotrophic). Results showed substantial differences in protein expression, with 17 proteins upregulated and 181 downregulated in Llanquihue, linked to elevated levels of copper, manganese, dissolved solids, phosphate, and nitrogen. These stressors caused metabolic damage and environmental stress in D. pulex. Our findings highlight the importance of monitoring pollution’s effects on Northern Patagonian ecosystems, especially on keystone species like D. pulex, essential for ecosystem stability. This research provides fresh molecular–ecological insights into pollution’s impacts, a perspective rarely addressed in this region. Understanding these effects is critical for conserving natural resources and offers pathways to study adaptive mechanisms in keystone species facing pollution. This approach also informs strategies for ecosystem management and restoration, addressing both immediate and long-term challenges in Northern Patagonian aquatic environments.

In heart failure (HF) patients undergoing cardiac surgery, an increased activity of mechanisms related to cardiac remodeling may determine a higher risk of postoperative atrial fibrillation (POAF). Given that atrial fibrillation (AF) has a negative impact on the course and management of HF, including the need for anticoagulation therapy, identifying the factors associated with AF occurrence after cardiac surgery is crucial for the prognosis of these patients. POAF is thought to occur when various clinical and biochemical triggers act on susceptible cardiac tissue (first hit), with oxidative stress and inflammation during cardiopulmonary bypass (CPB) surgery being potential contributing factors (second hit). However, the molecular mechanisms involved in these processes remain poorly characterized. Recent research has shown that patients who later develop POAF often have pre-existing abnormalities in calcium handling and activation of NLRP3-inflammasome signaling in their atrial cardiomyocytes. These molecular changes may make cardiomyocytes more susceptible to spontaneous Ca2+-releases and subsequent arrhythmias, particularly when exposed to inflammatory mediators. Additionally, some clinical studies have linked POAF with elevated preoperative inflammatory markers, but there is a need for further research in order to better understand the impact of CPB surgery on local and systemic inflammation. This knowledge would make it possible to determine whether patients susceptible to POAF have pre-existing inflammatory conditions or cellular electrophysiological factors that make them more prone to developing AF and cardiac remodeling. In this context, the NLRP3 inflammasome, expressed in cardiomyocytes and cardiac fibroblasts, has been identified as playing a key role in the development of HF and AF, making patients with pre-existing HF with reduced ejection fraction (HFrEF) the focus of several clinical studies with interventions that act at this level. On the other hand, HFpEF has been linked to metabolic and non-ischemic risk factors, but more research is needed to better characterize the myocardial remodeling events associated with HFpEF. Therefore, since ventricular remodeling may differ between HFrEF and HFpEF, it is necessary to perform studies in both groups of patients due to their pathophysiological variations. Clinical evidence has shown that pharmacological therapies that are effective for HFrEF may not provide the same anti-remodeling benefits in HFpEF patients, particularly compared to traditional adrenergic and renin–angiotensin–aldosterone system inhibitors. On the other hand, there is growing interest in medications with pleiotropic or antioxidant/anti-inflammatory effects, such as sodium–glucose cotransporter 2 inhibitors (SGLT-2is). These drugs may offer anti-remodeling effects in both HFrEF and HFpEF by inhibiting pro-inflammatory, pro-oxidant, and NLRP3 signaling pathways and their mediators. The anti-inflammatory, antioxidant, and anti-remodeling effects of SGLT-2 i have progressively expanded from HFrEF and HFpEF to other forms of cardiac remodeling. However, these advances in research have not yet encompassed POAF despite its associations with inflammation, oxidative stress, and remodeling. Currently, the direct or indirect effects of NLRP3-dependent pathway inhibition on the occurrence of POAF have not been clinically assessed. However, given that NLRP3 pathway inhibition may also indirectly affect other pathways, such as inhibition of NF-kappaB or inhibition of matrix synthesis, which are strongly linked to POAF and cardiac remodeling, it is reasonable to hypothesize that this type of intervention could play a role in preventing these events.

Background: β-carotene is an essential antioxidant, providing protection against type 2 diabetes mellitus, cardiovascular illnesses, obesity, and metabolic syndrome. This study investigates the impact of β-carotene on biochemical parameters and pancreatic insulin expression in mice exposed to ethanol. Methods: Thirty-six C57BL/6 mice (Mus musculus) were divided into six groups: 1. C (control), 2. LA (3% alcohol dose), 3. MA (7% alcohol dose), 4. B (0.52 mg/kg body weight/day β-carotene), 5. LA+B (3% alcohol dose + 0.52 mg/kg body weight/day β-carotene), and 6. MA+B (7% alcohol dose plus 0.52 mg/kg body weight/day β-carotene). After 28 days, the animals were euthanized for serum and pancreatic tissue collection. Biochemical analysis and pancreatic insulin expression were performed. One-way ANOVA was used. Results: The B, LA+B, and MA+B groups improved insulin levels and decreased HOMA-β versus the C group, with the LA+B and MA+B groups also showing lower ADH and ALDH levels than their nonsupplemented counterparts (p < 0.05). The B, LA+B, and MA+B groups showed a greater β-cell mass area compared to the unsupplemented groups. Additionally, the LA+B and MA+B groups demonstrated significantly increased β-cell area and integrated optical density compared to the LA and MA groups, respectively (p < 0.001). Conclusions: In mice, β-cell loss led to increased glucose release due to decreased insulin levels. β-carotene appeared to mitigate ethanol’s impact on these cells, resulting in reduced insulin degradation when integrated optical density was used. These findings suggest that antioxidant supplementation may be beneficial in treating ethanol-induced type 2 diabetes in animal models.