Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

This article concisely addresses the history of cardiology as one of the most dynamic and transformative branches of medicine, referring to its history dating back to ancient times. It presents the case of Cuba and the development of this specialty in the province of Granma, primarily in Bayamo and Manzanillo. Special emphasis is placed on the advances in science and technology and the importance of training professionals in this field. Keywords: History of medicine; Cardiology; Cardiovascular diagnostic techniques; Medical education.

Oral cancer, one of the main causes of mortality worldwide, is commonly treated with chemoradiotherapy. However, these therapies have limitations. Recent research focuses on the use of nanoparticles like MgO and ZnO to improve treatment and to evaluate the nanocytotoxic effect of MgO and ZnO nanoparticles on lymphoblastic-origin cancer cells. Lymphoblastic-origin primary culture cancer cells characterized by immunohistochemistry (IHC) were used, and nanocytotoxicity tests were performed using MgO and ZnO nanoparticles at concentrations ranging from 0 to 1.33 mg/mL. Cell viability was measured using the MTT assay by UV-Vis. Statistical analysis was carried out using the t-student test and ANOVA (p ≤ 0.05). Histopathological analyses confirmed the presence of oral lymphoblastic neoplastic lesions with specific characteristics, positive for cyclin D1 and negative for CD3. The results showed slight toxicity at the maximum dose for both nanoparticles (80% for MgO and 94% for ZnO) with statistically significant dose-dependent reduction (p < 0.05). MgO and ZnO nanoparticles have a slight cytotoxic effect on lymphoblastic cancer cells, so it is necessary to develop more effective chemotherapeutic treatments based on nanoparticles in combination with antitumor agents to confirm this hypothesis.

The current phase of experimentation and design of agrochemicals formulated with micro- and nanotechnology renews both the promise of greater ecological efficacy to reduce the environmental and health impacts of conventional products, as well as the attention towards the safety of nanomaterials for human health, soils and biodiversity. In this framework, the paper aims to identify global regulatory trends for potential risks of agricultural nanotechnology. Through a review of literature and documentary sources, the paper systematizes the advances in agro-nanotechnology and the regulatory recommendations of international organizations for the establishment of standards. It then describes the regulatory frameworks in Argentina and Brazil, central countries in the production and consumption of agrochemicals worldwide. The article concludes that the scientific and productive advances of products containing nanoparticles do not wait for the conclusive proposal of nano-specific regulatory frameworks. In such a scenario, the discussion of regulatory alternatives and risk-anticipatory governance can contribute both to sustainability and to the generation of inputs for regulatory policies that are respectful of soil conservation, biodiversity, and the rights of consumers and workers. 

3D-printed scaffolds with heterogeneous pores emerge as a strategy for tissue regeneration. In this study, bone regeneration was evaluated in critical defects of Wistar rats due to osteoconduction of 3D-printed polylactic acid (PLA) scaffolds with different pore sizes: 250-300 µm in the periphery, followed by 350-400 µm and 400-740 µm in the centre. The small ones promote cell adhesion, while the large ones promote angiogenesis. The scaffolds were 3D printed with PLA, a thermoplastic, biocompatible, and bioresorbable material that has been rigorously approved by the United States Food and Drug Administration (FDA). We evaluated the pore size and porosity in vivo in defects of 9 mm in diameter in rat calvaria, calculating the mineralized tissue by the radiodensity of the Hounsfield units (HU) in microtomographic images at 8, 30, 60 and 90 days. The results showed a pore range of 200-800µm (as the design), and the porosity was 98%, which favored the flow of nutrients, oxygen, and waste elimination. Radiodense tissue was observed in vivo on day 30, evidently on day 90, agreeing with the HU 93.66 and 118.31 respectively. The results of this study demonstrate that 3D scaffolds with heterogeneous pores have a significant osteoconductive capacity in bone regeneration. This finding opens new possibilities and alternatives in the field of tissue bioengineering, potentially revolutionizing the way we approach tissue regeneration. 

Epilepsy represents a significant health concern, affecting an estimated 2 million individuals in Mexico, with patients enduring more than 70 seizures daily. In the present study, refractory epilepsy was induced in Wistar rats by repeated stimulation with pentylenetetrazol (PTZ), ranging from one to one hundred stimulations. Hippocampal tissue was analyzed via scanning electron microscopy (SEM) and energy-dispersive X-ray fluorescence (EDS). The formation of solid calcium carbonate (CaCO3) crystals within the epileptic focus where observed. Notably, the concentration of CaCO3 exhibited a direct correlation with the number of stimulations, suggesting a progressive increase over the course of these events. This study puts forth a hypothesis elucidating the mechanism behind CaCO3 crystal formation in response to PTZ-induced seizures. Further research is needed to ascertain whether there exists a correlation between the dysregulation of calcium ions (Ca2+) in epilepsy and the formation of CaCO3. This inquiry opens avenues for deeper understanding and potential advancements in the diagnosis of epilepsy and related neurological disorders.

Objective: to evaluate the antibacterial effect of bismuth subsalicylate nanoparticles (NPs-SSBi) against four bacteria, frequently associated with nosocomial infections. Methods: the NPs-SSBi were obtained in colloidal suspension by laser ablation of solids in liquids (ALSL). The size, composition, and stability of the NPs in suspension were analyzed by transmission electron microscopy and ultraviolet-visible spectroscopy. The planktonic growth and biofilm formation of two Gram-positive bacteria, S. aureus and S. epidermidis, and two Gram-negative bacteria, E. coli and P. aeruginosa, after exposure to different concentrations of NPs-SSBi (1.25 to 90 μg/mL), were evaluated by turbidity and XTT assays, respectively. Results: quasi-spherical crystalline NPs-SSBi were obtained, with a size of 4.5 ± 0.14 nm, which remain stable in colloidal suspension for at least 21 days. The NPs-SSBi inhibited the growth of all four bacteria, planktonic growth was reduced ≈80-92% at concentrations above 40 μL/mL, and biofilm formation ≈73-89% at concentrations of 80 and 90 μL/mL. Conclusions: the NPs-SSBi obtained by ALSL inhibited the growth of four important nosocomial bacteria, so they could be used for the control of health care-associated infections. 

To achieve greater survival of dental implants, a solid integration of the soft tissues in the transmucosal region with the prosthetic abutments is important. The objective of the study was to evaluate whether titanium abutment surfaces coated with graphene oxide improved cell adhesion. It has been shown that graphene oxide promotes the integration and stability of the cells that make up peri-implant soft tissues, increasing the biocompatibility, cell adhesion and antibacterial properties of titanium. In this study, the surfaces of anodized titanium pillars from the Nobel Biocare company were coated by immersion in a suspension of graphene oxide with water; they were subsequently placed in a muffle at 180°C for 2 hours to fix and dry the coating. The graphene oxide film was characterized by scanning electron microscopy, X-ray scattering spectroscopy (EDS), and elemental mapping. Finally, anodized titanium prosthetic abutments with or without graphene oxide coating were evaluated by adhesion tests. Scanning electron microscopy allowed us to observe the layers of graphene oxide deposited on the surface of the pillar, mapping verified the presence of carbon on the entire surface and EDS the presence of carbon and titanium. Biological assays demonstrated a significant increase in cell adhesion on graphene oxide-coated titanium pillars compared to their uncoated counterparts. These results allow us to conclude that the surfaces of the anodized titanium pillars were successfully coated with graphene oxide and that this coating had a favorable influence on cell adhesion.