Diabetic muscular atrophy is a complication of diabetes mellitus that can decrease quality of life. Its complex mechanisms include alterations in proteolytic pathways, oxidative stress, and intracellular lipid accumulation. NADPH oxidase enzymes (NOX) play a key role in the production of ROS, contributing to oxidative damage and insulin resistance. Apocynin, a NOX inhibitor, has antioxidant and anti-inflammatory effects, suggesting its therapeutic potential in various diabetic complications. This study evaluated the impact of apocynin on the mechanisms of muscle atrophy in slow- and fast-twitch muscles of diabetic rats. Diabetes was induced in male Wistar rats by intraperitoneal injection of a single dose of streptozotocin (60 mg/kg). Apocynin treatment (3 mg/kg/day) was administered for 8 weeks. Fasting blood glucose levels, lipid profile, and weight gain were measured. Both slow-twitch (soleus) and fast-twitch (extensor digitorum longus, EDL) skeletal muscles were weighed and used to assess triglycerides (TG) content, histological analysis, lipid peroxidation levels, and gene expression evaluated by qRT-PCR. Apocynin reduced blood glucose levels, improved body weight, and exhibited hypolipidemic effects. It significantly increased muscle weight in EDL and soleus, especially in EDL muscle, lowering triglycerides, lipid peroxidation, and increasing fiber size. Additionally, it decreased mRNA expression levels of MuRF-1, atrogin-1, myostatin and p47phox mRNA and upregulated PGC-1α and follistatin mRNA. Apocynin exerted a myoprotective effect by mitigating muscle atrophy in diabetic rats. Its effects were differentially mediated on TG accumulation and muscle fiber size, reducing oxidative stress, atrogene expression, and positively regulating PGC-1α.

Integrative studies are important for a better understanding of the functional development of fish digestive systems and the consequent design of suitable feeding regimes and ad-hoc diets. To characterize the ontogeny of digestive function in larvae and juveniles of two atherinopsids from South America, Odontesthes bonariensis and O. hatcheri, morphologic, histologic, and intestinal enzyme biochemical analyses were performed. Both species showed a functional digestive system from one week after hatching (wah) with a sustained high-level activity of the cytosolic enzyme leucine alanine peptidase (leu-ala) until 9 and 13 wah in O. hatcheri and O. bonariensis, respectively. Maximum specific leu-ala activities in both species were higher compared to other agastric and most gastric fish. These results and the abundant pinocytic vacuoles in the posterior intestine suggest that cytosolic digestion is crucial for these species. It seems that their apparent anatomically simple digestive system is compensated by an uncommonly early development and function of the digestive tract and accessory organs accompanied by high intestinal cytosolic activity. The above findings contribute to the understanding of the Atherinopsidae digestive model and, for the first time, suggest that under farming conditions, these species could be weaned at an early developmental stage with an appropriate balanced diet.

El pez blanco Chirostoma estor es una especie con alto potencial de cultivo y calidad nutricional. A pesar de los avances en su cultivo y alimentación, aún no se cuenta con una alimento balanceado que permita el buen crecimiento obtenido con el alimento vivo. En este trabajo se estudió el desarrollo de la actividad digestiva en la especie, desde la eclosión hasta los 150 días, usando solo alimento vivo para evitar afectar la maduración digestiva. Los análisis de actividad se realizaron con técnicas fluorómetricas (enzimas pancreáticas) y espectofotométricas (enzimas intestinales) validadas para evaluar maduración digestiva. El crecimiento observado fue comparable con el obtenido utilizando luz contínua y microdietas con proteína soluble y consorcio bacteriano. Se evidenció la necesidad de incluir rotíferos y nauplios de Artemia en los primeros estadíos. Los indicadores de maduración digestiva evidenciaron que C. estor sigue el modelo descrito para peces gástricos, con las particularidades de ser tardío -posterior a los 5 meses de vida-, presentar niveles muy elevados de actividad citosólica intestinal (leucin alanin peptidasa) y mantener esta actividad y la anclada a la membrana de los enterocitos durante el estadio juvenil. Por consiguiente, se recomienda un destete posterior al primer mes de vida, induciendo una maduración temprana.

Three-dimensional (3D) spheroid models have become essential in cancer biology, drug screening, and tissue engineering. However, their small size, fragile structure, and tendency to disintegrate during routine histoprocessing present persistent technical challenges. Conventional paraffin embedding often results in tissue fragmentation, loss of spatial orientation, and poor section quality, whereas cryosectioning often compromises cellular morphology. Here, we present a robust, cost-effective protocol for preserving and sectioning fragile 3D spheroids, resulting in high-quality histological sections with intact architecture and excellent cellular detail. The method involves optimized handling and embedding procedures that stabilize spheroids during standard formalin fixation, paraffin infiltration, and microtomy, eliminating mechanical distortion and preserving spherical integrity for consistent sectioning. We demonstrate successful application across different cell line spheroids, with subsequent compatibility with hematoxylin and eosin (H&E) staining protocols. Compared to conventional methods, our approach significantly reduces sample loss, improves inter-section reproducibility, and preserves fine structural features such as necrotic cores, proliferative zones, and extracellular matrix components. This protocol provides a reliable, accessible solution for routine histological analysis of fragile 3D spheroids, facilitating more accurate morphological and molecular assessment in translational research settings. Key features: Maintains spheroid integrity: Prevents mechanical distortion, fragmentation, and loss of spatial orientation during processing. Significantly reduces sample loss: Decreases failure rate compared to traditional methods, conserving valuable samples. Broad spheroid compatibility: Works effectively with primary tumor-derived, stem cell-derived, and co-culture spheroid models. Enables high-quality sectioning and staining: Delivers consistent, reproducible sections that are fully compatible with H&E, IHC, and IF. Graphical overview: