Butylated hydroxytoluene does not protect Chinese hamster ovary cells from chromosomal damage induced by high-dose rate 192Ir irradiation

Previous reports showed the protective effect of the synthetic antioxidant butylated hydroxytoluene (BHT) against the chromosomal damage induced by bleomycin (BLM), cadmium chloride and potassium dichromate. To test the hypothesis that this effect was exerted by inhibition and/or scavenging of reactive oxygen species (ROS), the effect of BHT on the chromosomal damage induced by a high dose-rate gamma rays (HDR 192Ir). Experiments were carried out by irradiating G1 CHO cells with nominal doses of 1, 2 or 3 Gy. BHT (doses of 1.0, 2.5 or 5.0 μg/ml) was added to the culture immediately before or immediately after irradiation. Cells were then incubated in the presence of BHT for 13 h until harvesting and fixation. Results obtained showed that BHT did not decrease the chromosomal damage induced by radiation in any consistent fashion. On the contrary, in cells post-treated with 5.0 μg/ml of BHT the yield of chromosomal aberrations increased in several experimental points. These results with ionizing radiation suggest that the previous observed protective effects of BHT on the chromosomal damage induced by chemical genotoxicants may not be mediated solely through the scavenging or inactivating reactive oxidative species. The decrease of the yield of chromosomal damage induced by BLM could be due to the union of BHT with a metallic ion, in this case Fe (II), required for the activation of BLM. In the same way, the protective effect of BHT on the chromosomal damage induced by cadmium chloride and potassium dichromate could be due to the decrease of the effective dose of both salts in the cell through the chelation of the cations by BHT.Instituto de Genética VeterinariaFacultad de Ciencias Veterinaria

Butylated hydroxytoluene does not protect Chinese hamster ovary cells from chromosomal damage induced by high-dose rate 192Ir irradiation

Previous reports showed the protective effect of the synthetic antioxidant butylated hydroxytoluene (BHT) against the chromosomal damage induced by bleomycin (BLM), cadmium chloride and potassium dichromate. To test the hypothesis that this effect was exerted by inhibition and/or scavenging of reactive oxygen species (ROS), the effect of BHT on the chromosomal damage induced by a high dose-rate gamma rays (HDR 192Ir). Experiments were carried out by irradiating G1 CHO cells with nominal doses of 1, 2 or 3 Gy. BHT (doses of 1.0, 2.5 or 5.0 μg/ml) was added to the culture immediately before or immediately after irradiation. Cells were then incubated in the presence of BHT for 13 h until harvesting and fixation. Results obtained showed that BHT did not decrease the chromosomal damage induced by radiation in any consistent fashion. On the contrary, in cells post-treated with 5.0 μg/ml of BHT the yield of chromosomal aberrations increased in several experimental points. These results with ionizing radiation suggest that the previous observed protective effects of BHT on the chromosomal damage induced by chemical genotoxicants may not be mediated solely through the scavenging or inactivating reactive oxidative species. The decrease of the yield of chromosomal damage induced by BLM could be due to the union of BHT with a metallic ion, in this case Fe (II), required for the activation of BLM. In the same way, the protective effect of BHT on the chromosomal damage induced by cadmium chloride and potassium dichromate could be due to the decrease of the effective dose of both salts in the cell through the chelation of the cations by BHT.Instituto de Genética VeterinariaFacultad de Ciencias Veterinaria

Cellular response to rare earth mixtures (La and Gd) as components of degradable Mg alloys for medical applications

Rare earth (RE) elements have been proposed to improve the corrosion resistance of degradable Mg alloys for medical applications. However, good biocompatibility of the elements released by Mg alloys during degradation is essential for their use in implants. Most studies are focused on material science and engineering aspects, but the effects of ions released at the biological interface are not frequently addressed. The aim of this study was to contribute to the knowledge of in vitro toxicological effects of two RE Mg-alloying elements, La and Gd, as individual ions and in mixtures with and without Mg ions. Different combinations (Mg + Gd, Mg + La, and Mg + Gd + La) were used to evaluate their possible synergistic effects on CHO-K1 cells. Two sets of experiments were designed to assess (1) the cyto-genotoxic effect of La and Gd ions by neutral red (NR) technique, Reduction of tetrazolium salt (MTT), Viability with Acridine Orange staining, Clonogenic test, and Comet assay; and, (2) the possible synergistic toxicological effect of La and Gd ions in mixtures, and the influence of osmolarity increase on cellular response. Cytotoxic effects of RE were found at concentrations ≥200 μM RE while DNA damage was detected for doses ≥1500 μM and ≥1600 μM for La and Gd, respectively. When mixtures of ions were evaluated, neither synergistic cytotoxic effects nor biological damage related to osmolarity increase were detected.Fil: Grillo, Claudia Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Alvarez, Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Fernandez Lorenzo, Monica Alicia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentina. Universidad Nacional de La Plata. Facultad de Ingenieria; Argentin

Cellular response to rare earth mixtures (La and Gd) as components of degradable Mg alloys for medical applications

Rare earth (RE) elements have been proposed to improve the corrosion resistance of degradable Mg alloys for medical applications. However, good biocompatibility of the elements released by Mg alloys during degradation is essential for their use in implants. Most studies are focused on material science and engineering aspects, but the effects of ions released at the biological interface are not frequently addressed. The aim of this study was to contribute to the knowledge of in vitro toxicological effects of two RE Mg-alloying elements, La and Gd, as individual ions and in mixtures with and without Mg ions. Different combinations (Mg + Gd, Mg + La, and Mg + Gd + La) were used to evaluate their possible synergistic effects on CHO-K1 cells. Two sets of experiments were designed to assess (1) the cyto-genotoxic effect of La and Gd ions by neutral red (NR) technique, Reduction of tetrazolium salt (MTT), Viability with Acridine Orange staining, Clonogenic test, and Comet assay; and, (2) the possible synergistic toxicological effect of La and Gd ions in mixtures, and the influence of osmolarity increase on cellular response. Cytotoxic effects of RE were found at concentrations ≥200 μM RE while DNA damage was detected for doses ≥1500 μM and ≥1600 μM for La and Gd, respectively. When mixtures of ions were evaluated, neither synergistic cytotoxic effects nor biological damage related to osmolarity increase were detected.Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicada

Biodegradation of metallic biomaterials: its relation with the generation of reactive oxygen species

Fil: Fagali, Natalia Soledad. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Grillo, Claudia Alejandra. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Puntarulo, Susana. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Fernández Lorenzo de Mele, Mónica. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentin

Factores asociados a la muerte y a la readmisión en Unidad de Terapia Intensiva

This study identifies the factors associated with death and readmission into the Intensive Care Unit. This is a longitudinal prospective study of 600 adult patients admitted in general Intensive Care Units of four hospitals in São Paulo, Brazil. The multiple regression analysis showed that patients with a longer length of stay and higher Nursing Activities Score, Simplified Acute Physiology Score II and Logistic Organ Dysfunction Score on the last day in the unit had a higher chance of death. Nevertheless, higher Nursing Activities Score and Logistic Organ Dysfunction Score on the first day in the intensive care unit were protective factors against death. Viral hepatitis as an antecedent increased the chance of readmission. On the other hand, higher Nursing Activities Score at discharge decreased this risk. It was concluded that the nursing workload was the main variable related to the outcomes analyzed.O objetivo deste estudo foi identificar os fatores associados ao óbito e à readmissão dos pacientes em unidade de terapia intensiva. Estudo prospectivo longitudinal, com 600 pacientes adultos, internados em unidade de terapia intensiva geral de quatro hospitais do município de São Paulo. A análise de regressão múltipla mostrou que os pacientes com maior tempo de internação, Nursing Activities Score, Simplified Acute Physiology Score II e Logistic Organ Dysfunction Score mais elevados, no último dia de internação, tiveram mais chance de morrer, porém, as pontuações mais altas do Nursing Activities Score e Logistic Organ Dysfunction Score, na admissão, foram fatores protetores para óbito na unidade. Antecedente de hepatite viral aumentou a chance de readmissão; ao contrário, a maior pontuação do Nursing Activities Score, na alta, diminuiu esse risco. Concluiu-se que a carga de trabalho de enfermagem foi variável de destaque em relação aos desfechos analisados.El objetivo de este estudio fue identificar los factores asociados con muerte y readmisión de pacientes en Unidad de Terapia Intensiva. Se trata de un estudio prospectivo longitudinal con 600 pacientes adultos, internados en Unidades de Terapia Intensiva general de cuatro hospitales del Municipio de Sao Paulo. El análisis de regresión múltiple mostró que los pacientes con mayor tiempo de internación, que tuvieron puntajes más elevados en: Nursing Activities Score, Simplified Acute Physiology Score II y Logistic Organ Dysfunction Score, en el último día de internación, tuvieron más probabilidad de morir; por otro lado las puntuaciones más altas del Nursing Activities Score y Logistic Organ Dysfunction Score, en la admisión, fueron factores protectores para muerte en la unidad. El antecedente de hepatitis viral aumentó la probabilidad de readmisión; al contrario, la mayor puntuación del Nursing Activities Score en el alta disminuyó ese riesgo. Se concluyó que la carga de trabajo de enfermería fue una variable destacada en relación a los resultados analizados.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Fatores associados ao óbito e a readmissão em Unidade de Terapia Intensiva

This study identifies the factors associated with death and readmission into the Intensive Care Unit. This is a longitudinal prospective study of 600 adult patients admitted in general Intensive Care Units of four hospitals in São Paulo, Brazil. The multiple regression analysis showed that patients with a longer length of stay and higher Nursing Activities Score, Simplified Acute Physiology Score II and Logistic Organ Dysfunction Score on the last day in the unit had a higher chance of death. Nevertheless, higher Nursing Activities Score and Logistic Organ Dysfunction Score on the first day in the intensive care unit were protective factors against death. Viral hepatitis as an antecedent increased the chance of readmission. On the other hand, higher Nursing Activities Score at discharge decreased this risk. It was concluded that the nursing workload was the main variable related to the outcomes analyzed.El objetivo de este estudio fue identificar los factores asociados con muerte y readmisión de pacientes en Unidad de Terapia Intensiva. Se trata de un estudio prospectivo longitudinal con 600 pacientes adultos, internados en Unidades de Terapia Intensiva general de cuatro hospitales del Municipio de Sao Paulo. El análisis de regresión múltiple mostró que los pacientes con mayor tiempo de internación, que tuvieron puntajes más elevados en: Nursing Activities Score, Simplified Acute Physiology Score II y Logistic Organ Dysfunction Score, en el último día de internación, tuvieron más probabilidad de morir; por otro lado las puntuaciones más altas del Nursing Activities Score y Logistic Organ Dysfunction Score, en la admisión, fueron factores protectores para muerte en la unidad. El antecedente de hepatitis viral aumentó la probabilidad de readmisión; al contrario, la mayor puntuación del Nursing Activities Score en el alta disminuyó ese riesgo. Se concluyó que la carga de trabajo de enfermería fue una variable destacada en relación a los resultados analizados.O objetivo deste estudo foi identificar os fatores associados ao óbito e à readmissão dos pacientes em unidade de terapia intensiva. Estudo prospectivo longitudinal, com 600 pacientes adultos, internados em unidade de terapia intensiva geral de quatro hospitais do município de São Paulo. A análise de regressão múltipla mostrou que os pacientes com maior tempo de internação, Nursing Activities Score, Simplified Acute Physiology Score II e Logistic Organ Dysfunction Score mais elevados, no último dia de internação, tiveram mais chance de morrer, porém, as pontuações mais altas do Nursing Activities Score e Logistic Organ Dysfunction Score, na admissão, foram fatores protetores para óbito na unidade. Antecedente de hepatite viral aumentou a chance de readmissão; ao contrário, a maior pontuação do Nursing Activities Score, na alta, diminuiu esse risco. Concluiu-se que a carga de trabalho de enfermagem foi variável de destaque em relação aos desfechos analisados

Butylated hydroxytoluene does not protect Chinese hamster ovary cells from chromosomal damage induced by high-dose rate 192Ir irradiation

Previous reports showed the protective effect of the synthetic antioxidant butylated hydroxytoluene (BHT) against the chromosomal damage induced by bleomycin (BLM), cadmium chloride and potassium dichromate. To test the hypothesis that this effect was exerted by inhibition and/or scavenging of reactive oxygen species (ROS), the effect of BHT on the chromosomal damage induced by a high dose-rate gamma rays (HDR 192Ir). Experiments were carried out by irradiating G1 CHO cells with nominal doses of 1, 2 or 3 Gy. BHT (doses of 1.0, 2.5 or 5.0 μg/ml) was added to the culture immediately before or immediately after irradiation. Cells were then incubated in the presence of BHT for 13 h until harvesting and fixation. Results obtained showed that BHT did not decrease the chromosomal damage induced by radiation in any consistent fashion. On the contrary, in cells post-treated with 5.0 μg/ml of BHT the yield of chromosomal aberrations increased in several experimental points. These results with ionizing radiation suggest that the previous observed protective effects of BHT on the chromosomal damage induced by chemical genotoxicants may not be mediated solely through the scavenging or inactivating reactive oxidative species. The decrease of the yield of chromosomal damage induced by BLM could be due to the union of BHT with a metallic ion, in this case Fe (II), required for the activation of BLM. In the same way, the protective effect of BHT on the chromosomal damage induced by cadmium chloride and potassium dichromate could be due to the decrease of the effective dose of both salts in the cell through the chelation of the cations by BHT.Instituto de Genética VeterinariaFacultad de Ciencias Veterinaria

Patient Destination after Discharge from Intensive Care Units: Wards or Intermediate Care Units?

This study characterizes patients hospitalized in Intensive Care Units (ICUs) of hospitals that have intermediate units (IU) regarding their demographic and clinical data and identifies factors related to discharge from these units. This prospective longitudinal study involved 600 adult patients hospitalized in general ICUs in four hospitals in São Paulo, SP, Brazil. Demographic and clinical characteristics were similar to those found in other studies addressing patients hospitalized in ICUs. Factors associated with discharge from ICU to IU were: age ≥60 years, diseases related to the nervous, circulatory or respiratory systems, originated from the IU, and Simplified Acute Physiologic Score II (SAPS II), Logistic Organ Dysfunction (LODS) and Nursing Activities Scores (NAS) at admission and discharge from the ICU. Age and risk of death at admission in the ICU, according to SAPS II, stood out as indicators of discharge to IUs in the Multiple Logistic Regression analysis.Este estudio tuvo como objetivos caracterizar a los pacientes internados en unidades de terapia intensiva (UTI) de hospitales con unidades intermediarias - en lo que se refiere a los datos demográficos y clínicos - e identificar los factores relacionados con el alta médica para esa unidad. Es estudio prospectivo longitudinal, con 600 pacientes adultos, internados en UTIs generales de cuatro hospitales del municipio de Sao Paulo. En los resultados, las características demográficas y clínicas fueron similares a las descritas en otros estudios sobre pacientes en UTIs. Los factores asociados con el alta hospitalaria para la unidad intermediaria fueron: edad ≥60 años, antecedentes relacionados al sistema nervioso, circulatorio o respiratorio, procedencia de la unidad intermediaria y valores del Simplified Acute Physiologic Score II (SAPS II), Logistic Organ Dysfunction (LODS) y Nursing Activities Score (NAS) en la admisión y el alta de la UTI. En el análisis de regresión logística múltiple la edad y el riesgo de muerte en la admisión, por el SAPS II, se destacaron como indicadores del alta médica para la unidad intermediaria.Este estudo teve como objetivos caracterizar os pacientes internados em unidade de terapia intensiva (UTI) de hospitais com unidades intermediárias, quanto aos dados demográficos e clínicos, e identificar os fatores relacionados à alta para essa unidade. É estudo prospectivo longitudinal, com 600 pacientes adultos, internados em UTIs gerais de quatro hospitais do município de São Paulo. Nos resultados, as características demográficas e clínicas foram similares às descritas em outros estudos sobre pacientes em UTIs. Os fatores associados à alta para unidade intermediária foram: idade ≥60 anos, antecedentes relacionados ao sistema nervoso, circulatório ou respiratório, procedência da unidade intermediária e valores do Simplified Acute Physiologic Score II (SAPS II), Logistic Organ Dysfunction (LODS) e Nursing Activities Score (NAS) na admissão e alta da UTI. Na análise de regressão logística múltipla a idade e o risco de morte na admissão, pelo SAPS II, destacaram-se como indicadores de alta para unidade intermediária

Phosphonopropionic acid coating as platform for the efficient grafting of (bio)molecules to hydroxyapatite nanoparticles

A new synthesis strategy intended to increase apatite available surface groups for the covalent functionalization with (bio)molecules was developed. To that purpose, hydroxyapatite nanoparticles (Ap) were synthesized and terminated with 3-phosphonopropionic acid (PPA) yielding Ap with surface bound propionic acid through P-C bonds (ApCOO– ). A thorough characterization of ApCOO– by IR spectroscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, thermal gravimetric analysis, and specific surface area determination (BET model), strongly support an efficient surface grafting of the organophosphonates and a hydroxyapatite core of similar morphology and phase composition to that of synthetic Ap. ApCOO– was able to adsorb bovine serum albumin (BSA) up to 0.20 mg m–2 and showed no cytotoxic effects towards Balb/C 3T3 cells. ApCOO– abundant carboxyl surface groups facilitated the particles grafting through stable amide bonds with basic fuchsin (Fu) and tyrosine (Ty) yielding well covered surfaces. Fu-bound hydroxyapatite powders showed ten times stronger fluorescence than free Fu in ethanol, thus expanding the potential uses of Ap as fluorescent sensors in the red region of the visible spectrum. On the other hand, Ty-bound hydroxyapatite powders showed negative surface charges and high stability of the coating in aqueous suspensions. In contrast, Ty-physically adsorbed hydroxyapatite powders rendered positively charged surfaces and an unstable coating.Fil: Dittler, Maria Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Rodriguez, Hernan Bernardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Cippollone, Mariano. YPF - Tecnología; ArgentinaFil: Grillo, Claudia Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Gonzalez, Monica Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentin