Evaluating the QileX-RhE skin corrosion test for chemical subcategorization in accordance with OECD TG 431.

Skin corrosion testing is integral to evaluating the potential harm posed by chemicals, impacting regulatory decisions on safety, transportation, and labeling. Traditional animal testing methods are giving way to in vitro alternatives, such as reconstructed human epidermis (RhE) models, aligning with evolving ethical standards. This study evaluates the QileX-RhE test system's performance for chemical subcategorization within the OECD TG 431 framework. Results demonstrate its ability to differentiate subcategories, accurately predicting 83% of UN GHS Category 1A and 73% of UN GHS Category 1B/1C chemicals with 100% sensitivity in corrosive prediction. Additionally, this study provides a comprehensive assessment of the test method's performance by employing nuanced parameters such as positive predictive value (PPV), negative predictive value (NPV), post-test odds and likelihood rations, offering valuable insights into the applicability and effectiveness of the QileX-RhE test method.

[Analysis of pediatric «short stays¼ in a second-level hospital throughout 25 years]. / Análisis de las «estancias cero¼ pediátricas en un hospital de nivel 2 a lo largo de 25 años.

INTRODUCTION: It is essential to admit patients to hospital in an efficient way in order to use resources rationally. Short hospitalary stays are hospitalizations which does not include 00:00h and are considered avoidable. This study describes trends and characteristics of short stays throughout 25 years in our hospital. PATIENTS AND METHODS: We analyzed hospital pediatric discharges in a second-level hospital through the registration system «conjunto mínimo básico de datos¼. We categorized pediatric patients and newborn patients in two groups according to length of hospital stay: «short stays¼ and «prolonged stays¼. We analyzed and compared the following variables: gender, age, type of admission, month, diagnosis-related groups (DRG) and admission service. Binary logistic regression analysis and assessment of trends through joinpoint regression analysis were performed. RESULTS: From 1993 to 2017, 45710 children were admitted to our hospital, of which 7.3% were short stays. The trend analysis showed a point of change upwards-downwards at the beginning of the millennium. Pediatric short stays: the most important variables were emergency admissions (89%), urgent transfers (9%), month December (11%) and main diagnosis category: nervous system (18%). Mean diagnosis-related groups cost was 2432±1115€ in short stays group and 2549±1065€ in prolonged stays. CONCLUSIONS: Short stays and prolonged stays show a falling trend in our hospital. Short stays percentage in our environment is similar to other neighbor countries. Some of our short stays are urgent transfers and admissions for clinical observation. We did not find clinical significance in weight or cost of pediatric patients' DRG comparing to prolonged stays.

Efectos de nuevos agentes regenerativos biomiméticos sobre la cicatrización corneal en un modelo experimental de úlceras posquirúrgicas / Effects of new biomimetic regenerating agents on corneal wound healing in an experimental model of post-surgical corneal ulcers

OBJETIVO: El propósito de este estudio es evaluar la eficacia de la aplicación tópica de RGTA-cacicol (Regenerative Agent-cacicol) en un modelo experimental de úlcera corneal tras queratectomía fotorrefractiva (PRK) en ratones. MÉTODOS: Los ratones fueron tratados mediante cirugía PRK con una zona de ablación de 2,0 mm en la córnea central y 45 μm de profundidad con un láser excimer VISX Star S2. Las córneas fueron tratadas tópicamente con gotas de cacicol una hora y 48 h después de la lesión. Los grupos control recibieron BSS (solución estéril de irrigación) en la misma posología. Los eventos clínicos e histopatológicos fueron evaluados 1, 2, 3 y 7 días después de la cirugía. Sobre secciones obtenidas a través de la región central de las córneas se realizaron técnicas inmunofluorescentes para α-SMA (transformación de miofibroblastos), E-cadherina (ensamblaje de las células epiteliales) y β-tubulina neuronal clase III (inervación). RESULTADOS: Las córneas tratadas tópicamente con cacicol durante 7 días mostraron un mayor grado de transparencia en comparación con el control. Además presentaban una mejor citoarquitectura epitelial. El análisis de los perfiles α-SMA en el estroma demostró que el cacicol reduce o retrasa la presencia de miofibroblastos en el estroma en comparación con BSS (p < 0,001). Finalmente se encontró un posible efecto neurorregenerativo de cacicol en córneas tratadas mediante una lesión experimental PRK. En algunos casos se podría dar variabilidad interindividual debido al diseño del modelo experimental, lo que supone una limitación a tener en cuenta pese a la significación estadística de los datos. CONCLUSIONES: En un modelo de lesiones quirúrgicas inducidas por láser en la córnea, la aplicación tópica de RGTA podría evitar la formación de cicatrices y la aparición de miofibroblastos y favorecer la regeneración nerviosa

OBJECTIVE: The purpose of this study is to assess the effectiveness of the topical application of cacicol regenerating agent (RGTA) in an experimental model of corneal ulcer after photorefractive keratectomy (PRK) in mice. METHODS: Mice were subjected to PRK surgery with a 2.0 mm ablation zone on the central cornea and 45 mm of depth on a VISX Star S2 excimer laser. Corneas were treated topically with cacicol drops 1 hour and 48 hours after injury. Control groups received balanced salt solution (BSS) in the same dosage. Clinical and histopathological events were evaluated at 1, 2, 3 and 7 days after surgery. Sections obtained through the central region of the corneas were used to analyze the histopathological events of injured and healed corneas. αSMA (myofibroblast transformation), E cadherin (assembly of epithelial cells) and neuronal class III β-tubulin (innervation) were performed. RESULTS: Corneas treated topically with cacicol for 7 days showed a greater degree of transparency compared to controls. cacicol treated corneas showed improved epithelial cytoarchitecture. Analysis of αSMA profiles in the stroma showed that cacicol reduced or delayed the presence of myofibroblasts in the stroma compared to BSS (P<0.001). Finally, a putative neuroregenerative effect of cacicol was found in corneas subjected to an experimental PRK lesion. In some cases some interindividual variability could be observed due to the design of the experimental model. This is a limitation to consider, despite the statistical significance of the data. CONCLUSIONS: In a model of laser induced surgical lesions in the cornea, topical application of an RGTA (i.e. cacicol) could be involved in avoiding myofibroblast scarring formation and promoting nerve regeneration

Effects of new biomimetic regenerating agents on corneal wound healing in an experimental model of post-surgical corneal ulcers.

OBJECTIVE: The purpose of this study is to assess the effectiveness of the topical application of cacicol regenerating agent (RGTA) in an experimental model of corneal ulcer after photorefractive keratectomy (PRK) in mice. METHODS: Mice were subjected to PRK surgery with a 2.0mm ablation zone on the central cornea and 45mm of depth on a VISX Star S2 excimer laser. Corneas were treated topically with cacicol drops 1hour and 48hours after injury. Control groups received balanced salt solution (BSS) in the same dosage. Clinical and histopathological events were evaluated at 1, 2, 3 and 7 days after surgery. Sections obtained through the central region of the corneas were used to analyze the histopathological events of injured and healed corneas. αSMA (myofibroblast transformation), E cadherin (assembly of epithelial cells) and neuronal class III ß-tubulin (innervation) were performed. RESULTS: Corneas treated topically with cacicol for 7 days showed a greater degree of transparency compared to controls. cacicol treated corneas showed improved epithelial cytoarchitecture. Analysis of αSMA profiles in the stroma showed that cacicol reduced or delayed the presence of myofibroblasts in the stroma compared to BSS (P<0.001). Finally, a putative neuroregenerative effect of cacicol was found in corneas subjected to an experimental PRK lesion. In some cases some interindividual variability could be observed due to the design of the experimental model. This is a limitation to consider, despite the statistical significance of the data. CONCLUSIONS: In a model of laser induced surgical lesions in the cornea, topical application of an RGTA (i.e. cacicol) could be involved in avoiding myofibroblast scarring formation and promoting nerve regeneration.

Plasma rich in growth factors (PRGF-Endoret) stimulates corneal wound healing and reduces haze formation after PRK surgery.

This study evaluated the efficacy of Plasma rich in growth factors (PRGF-Endoret) on the corneal wound healing process after Photorefractive keratectomy (PRK). To address this, blood from three healthy donors was collected, centrifuged and, the whole plasma column (WP) and the plasma fraction with the highest platelet concentration (F3) were collected. The effects of F3 and WP on the proliferation and migration of human corneal epithelial cells (HCE) were analyzed. PRK was performed on C57BL/6 mice. Animals were divided in three treatment groups: Control, F3, and WP. Corneal wound healing and haze formation were evaluated macroscopically. Eyes were collected at 1, 2, 3, and 7 days after surgery, and were processed for histological studies. Immunofluorescence was used to assess cellular proliferation, apoptosis and myofibroblast transformation in the mouse cornea. Results showed a significant increased on proliferation and wound healing after F3 and WP treatment when compared with control group. In vivo studies showed significant reduction on haze formation in mice treated with both PRGF-Endoret formulations (F3 and WP). Histological studies showed an increase of epithelial cell proliferation in corneas of control group, promoting an epithelial hyperplasia. The number of SMA-positive cells (corresponding to myofibroblast differentiation) was significantly lower in the PRGF-Endoret group than in the control group, correlating with the higher transparence results observed macroscopically in both PRGF-Endoret groups. According to this, it can be concluded that PRGF-Endoret accelerates corneal tissue regeneration after PRK, reducing haze formation.

A method for obtaining Schwann cell cultures from adult rabbit nerve based on "in vitro" pre-degeneration and neuregulin treatment.

Schwann cells (SCs) are basic elements for cell therapy and tissue engineering in the central and peripheral nervous system. Therefore, the development of a reliable method to obtain SC cultures is required. For possible therapeutic applications the cultures need to produce a sufficiently large number of SCs with a high level of purity in a relatively short period of time. To increase SC yield and purity we pre-degenerated pieces of 1-2 mm of adult rabbit sciatic nerves by incubating them for seven days in Dulbecco's Modified Eagle's Medium supplemented with 10% fetal bovine serum, penicillin/streptomycin and NRG1-ß1. Following pre-degeneration the nerve pieces were dissociated and then cultured for 6 or 15 days in the same culture medium. After 6 days of culture we obtained around 9.5x10³ cells/mg with approximately 94% SCs (S-100 positive) purity. After 15 days of culture the yield was about 80x10³ cells/mg and the purity was approximately 75%. Pre-degeneration and subsequent culture of small pieces of adult nerve with NRG1-ß1 supplemented medium increased the number of SCs and restricted the overgrowth of fibroblast-like cells.

Absence of relevant effects of 5 mT static magnetic field on morphology, orientation and growth of a rat Schwann cell line in culture.

The aim of this study is to observe possible changes in the morphology, orientation or cell growth of an in vitro cultured Schwann cell line by 24 h exposure to 5 mT static magnetic fields. The magnetic field generator basically consists of a pair of circular coils in a Helmholtz arrangement and enables temperature to be controlled (37+/-0.1 degrees C). We did not find any statistically significant differences in the cell growth rate between control and exposed cells, nor did we observe any differences in cell morphology or orientation.