A simple and effective method to synthesize fluorescent nanoparticles using tryptophan and light and their lethal effect against bacteria.

A simple, environmentally friendly and cost-effective method was used to synthesize silver nanoparticles using tryptophan and light. To prepare the nanoparticles, the following components were used: deionized water, silver nitrate, light and tryptophan. The effects of the tryptophan concentration and light exposure time on the formation of tryptophan silver nanoparticles (Tnnps) were studied. The synthesized Tnnps were characterized using transmission electron microscopy (TEM), absorption and fluorescence spectroscopy and zeta potential measurements. The synthesized Tnnps were nearly spherical, with sizes of approximately 17 nm. In addition, the antibacterial activity of Tnnps was determined by monitoring the growth curves of strains of Escherichia coli, Pseudomonas aeruginosa, Staphylococcus epidermidis, Serratia marcescens, and Enterococcus faecalis using the microdilution test. The Minimum Inhibitory Concentration (MIC) for 4 of 5 tested bacteria was determined to be between 20.0 and 17.5 µg/mL for 48 h and between 22.5 and 20.0 µg/mL for 72 h.

Red blood cell transfusions worsen the outcomes even in critically ill patients undergoing a restrictive transfusion strategy.

CONTEXT AND OBJECTIVE: Anemia and blood transfusions are common in intensive care. This study aimed to evaluate epidemiology and outcomes among critically ill patients under a restrictive transfusion strategy. DESIGN AND SETTING: Prospective observational cohort study in an intensive care unit (ICU) at a tertiary hospital. METHODS: All adults admitted to the ICU over a one-year period who remained there for more than 72 hours were included, except those with acute coronary syndrome, ischemic stroke, acute hemorrhage, prior transfusion, pregnant women and Jehovah's Witnesses. The restrictive strategy consisted of transfusion indicated when hemoglobin levels were less than or equal to 7.0 g/dl. RESULTS: The study enrolled 167 patients; the acute physiology and chronic health evaluation II (APACHE II) score was 28.9 ± 6.5. The baseline hemoglobin level was 10.6 ± 2.2 g/dl and on day 28, it was 8.2 ± 1.3 g/dl (P < 0.001). Transfusions were administered to 35% of the patients. In the transfusion group, 61.1% did not survive, versus 48.6% in the non-transfusion group (P = 0.03). Transfusion was an independent risk factor for mortality (P = 0.011; odds ratio, OR = 2.67; 95% confidence interval, CI = 1.25 to 5.69). ICU stay and hospital stay were longer in the transfusion group: 20.0 (3.0-83.0) versus 8.0 (3.0-63.0) days (P < 0,001); and 24.0 (3.0-140.0) versus 14.0 (3.0-80.0) days (P = 0.002), respectively. CONCLUSIONS: In critically ill patients, there was a reduction in hemoglobin with increasing length of ICU stay. Moreover, transfusion was associated with worse prognoses.

Red blood cell transfusions worsen the outcomes even in critically ill patients undergoing a restrictive transfusion strategy / Transfusões de concentrados de hemácias pioram os resultados mesmo em pacientes graves, submetidos a estratégia restritiva de transfusão

CONTEXT AND OBJECTIVE: Anemia and blood transfusions are common in intensive care. This study aimed to evaluate epidemiology and outcomes among critically ill patients under a restrictive transfusion strategy. DESIGN AND SETTING: Prospective observational cohort study in an intensive care unit (ICU) at a tertiary hospital. METHODS: All adults admitted to the ICU over a one-year period who remained there for more than 72 hours were included, except those with acute coronary syndrome, ischemic stroke, acute hemorrhage, prior transfusion, pregnant women and Jehovah's Witnesses. The restrictive strategy consisted of transfusion indicated when hemoglobin levels were less than or equal to 7.0 g/dl. RESULTS: The study enrolled 167 patients; the acute physiology and chronic health evaluation II (APACHE II) score was 28.9 ± 6.5. The baseline hemoglobin level was 10.6 ± 2.2 g/dl and on day 28, it was 8.2 ± 1.3 g/dl (P < 0.001). Transfusions were administered to 35% of the patients. In the transfusion group, 61.1% did not survive, versus 48.6% in the non-transfusion group (P = 0.03). Transfusion was an independent risk factor for mortality (P = 0.011; odds ratio, OR = 2.67; 95% confidence interval, CI = 1.25 to 5.69). ICU stay and hospital stay were longer in the transfusion group: 20.0 (3.0-83.0) versus 8.0 (3.0-63.0) days (P < 0,001); and 24.0 (3.0-140.0) versus 14.0 (3.0-80.0) days (P = 0.002), respectively. CONCLUSIONS: In critically ill patients, there was a reduction in hemoglobin with increasing length of ICU stay. Moreover, transfusion was associated with worse prognoses.

CONTEXTO E OBJETIVO: Anemia e transfusões sanguíneas são comuns em terapia intensiva. O objetivo deste estudo foi investigar a epidemiologia e resultados em pacientes críticos sob o regime de transfusão restritiva. TIPO DE ESTUDO E LOCAL: Estudo de coorte, prospectivo e observacional em unidade de terapia intensiva de um hospital terciário. MÉTODOS: Foram incluídos todos adultos admitidos na unidade durante um ano e que permaneceram internados por mais de 72 horas, exceto pacientes com lesão coronariana aguda, isquemia cerebral aguda, hemorragia aguda, transfusão anterior, mulheres grávidas e testemunhas de Jeová. A estratégia restritiva consiste na transfusão indicada com a hemoglobina inferior ou igual a 7.0 g/dl. RESULTADOS: Totalizando 167 pacientes incluídos, APACHE II (Acute Physiology and Chronic Health disease II) foi de 28,9 ± 6,5. O valor da hemoglobina basal foi de 10,6 ± 2.2 g/dl e no 28º dia foi de 8,2 ± 1.3 g/dl (P < 0,001). 35% dos pacientes receberam transfusões. No grupo de transfusão 61,1% não sobreviveram versus 48,6% do grupo não transfusão (P = 0,03). A transfusão foi fator de risco independente de mortalidade (P = 0,011; odds ratio, OR = 2,67; intervalo de confiança, IC 95% = 1,25-5,69). A internação na unidade de terapia intensiva e hospitalar foi maior no grupo de transfusão: 20,0 (3,0-83,0) versus 8,0 (3,0-63,0) dias (P < 0,001); e 24,0 (3,0-140,0) versus 14,0 (3,0-80,0) dias (P = 0,002). CONCLUSÕES: Em pacientes graves, observou-se redução da hemoglobina com a progressão da permanência na UTI. Além disso, a transfusão foi associada com piores prognósticos.