Biodisponibilidad. Concepto y cuantificación. Aplicación a emplazamientos contaminados con hidrocarburos policíclicos aromáticos

39 páginas.-- 25 figuras.-- 2 tablas.-- 36 referencias. Memoria del XL Curso Internacional de Edafología y Biología Vegetal, 2003Director del trabajo: Ortega Calvo, J. J.La presencia de contaminantes en la naturaleza representa una amenanza para la salud humana y para los ecosistemas. En este sentido es importante tener presente que la mencionada amenaza depende dedos factores relativamente independientes entre si; por una parte de la toxicidad de la sustancia en si misma y por otra de la probabilidad de que la sustancia en cuestión pueda entrar en contacto con la población que se ve amenazada, lo que puede tener lugar mediante el transporte del mismo en cualquiera de las fases móviles que constituyen el entorno, o mediante el contacto directo con el contaminante. El riesgo asociado a la presencia de estas sustancias en medios como el aire o el agua se cuantifica, normalmente, a través de la medida de su concentración en dichos medios y de modelos que representan los fenómenos que tienen lugar durante su transporte: dispersión, dilución, degradación, etc. A pesar de la complejidad de estos modelos, resultan considerablemente más simples que los necesarios para representar otros compartimentos del medio ambiente, como el suelo o los sedimentos.Peer reviewe

Evaluation of grip strength in hook of hamate fractures treated with osteosynthesis. Is this surgical treatment necessary?

Objective: The aim of this study was to evaluate the outcomes of open reduction and internal fixation (ORIF) in hamate hook fractures and review the literature on this surgical procedure. Methods: We report the outcomes of ORIF of hamate hook fractures in 13 consecutive patients (12 men and 1 woman; mean age: 32 years (range, 22-48 years)). In eight patients (61%) the fracture was associated with ulnar nerve neuritis in Guyon's canal. We assessed the following clinical data: age, sex, mechanism of injury, side of the injured hand and associated lesions, fracture classification, average time from injury to correct diagnosis, surgical technique, complications, and length of follow-up. All patients underwent radiological imaging, including standard radiographs in two planes (anteroposterior and lateral projections), and a CT study. Functional outcomes evaluated were pain, range of motion, grip strength, Disabilities of the arm, shoulder and hand (DASH) and Mayo wrist score. Results: The mean follow-up was 36 months (range, 12-144 months). All 13 cases were treated with ORIF of the hook of the hamate. Mean VAS pain score was 5 preoperatively (4-9) and 1 (0-2) postoperatively. All patients returned to pre-injury level and only one patient felt pain on activity. Preoperative modified Mayo wrist score was 51 and the postoperative value was 94. All outcomes scores improved significantly from preoperative values. The patients who participated in sports postoperatively were able to do so at or near pre-injury levels. Postoperative average range of wrist motion was 76° in extension, 71° in flexion, 14° in ulnar deviation, and 21° in radial deviation. Mean grip strength in the hand with the hook fracture was 58 kg compared with 53 Kg in the unaffected hand. All patients returned to their pre-injury level of functioning after 10-12 weeks and there were no complications. Analysis of grip strength revealed values comparable with the unaffected hand. Conclusion: ORIF of hamate hook fractures is a safe and effective technique to restore normal grip strength and return to pre-injury level. In cases of ulnar nerve neuritis, neurolysis of the deep palmar branch is mandatory. Level of evidence: Level IV, Therapeutic study

Evolution of the use of corticosteroids for the treatment of hospitalised COVID-19 patients in Spain between March and November 2020: SEMI-COVID national registry

Objectives: Since the results of the RECOVERY trial, WHO recommendations about the use of corticosteroids (CTs) in COVID-19 have changed. The aim of the study is to analyse the evolutive use of CTs in Spain during the pandemic to assess the potential influence of new recommendations. Material and methods: A retrospective, descriptive, and observational study was conducted on adults hospitalised due to COVID-19 in Spain who were included in the SEMI-COVID- 19 Registry from March to November 2020. Results: CTs were used in 6053 (36.21%) of the included patients. The patients were older (mean (SD)) (69.6 (14.6) vs. 66.0 (16.8) years; p < 0.001), with hypertension (57.0% vs. 47.7%; p < 0.001), obesity (26.4% vs. 19.3%; p < 0.0001), and multimorbidity prevalence (20.6% vs. 16.1%; p < 0.001). These patients had higher values (mean (95% CI)) of C-reactive protein (CRP) (86 (32.7-160) vs. 49.3 (16-109) mg/dL; p < 0.001), ferritin (791 (393-1534) vs. 470 (236- 996) µg/dL; p < 0.001), D dimer (750 (430-1400) vs. 617 (345-1180) µg/dL; p < 0.001), and lower Sp02/Fi02 (266 (91.1) vs. 301 (101); p < 0.001). Since June 2020, there was an increment in the use of CTs (March vs. September; p < 0.001). Overall, 20% did not receive steroids, and 40% received less than 200 mg accumulated prednisone equivalent dose (APED). Severe patients are treated with higher doses. The mortality benefit was observed in patients with oxygen saturation </=90%. Conclusions: Patients with greater comorbidity, severity, and inflammatory markers were those treated with CTs. In severe patients, there is a trend towards the use of higher doses. The mortality benefit was observed in patients with oxygen saturation </=90%

Effect of slow desorption on the kinetics of biodegradation of polycyclic aromatic hydrocarbons

The bioavailability to bacteria of 14C-labeled polycyclic aromatic hydrocarbons (PAHs) sorbed onto lake sediments was assessed using a mathematical model and three experimental series. The experiments were performed under similar conditions and included: (1) abiotic desorption of PAHs from sediments by Tenax extraction, (2) mineralization of dissolved PAHs with no sediment present, and (3) mineralization of PAHs sorbed onto sediments. Results obtained from the first two series were used to obtain the parameter values for the model, and the experimental results of the third series were compared to model results. We found that microorganisms were able to promote desorption of the more-labile fractions, but were unable to increase the desorption rate of the slow- and very slow-desorbing fractions. Also, our model predictions indicate that, after very long contact times, and in the concurrence of biodegradation, sorbed PAHs remain not under equilibrium conditions, but rather in a steady state. The net rates of PAH desorption from the three sediment domains considered (fast, slow, and very slow) become similar, and the ratio between the aqueous and the sediment concentration remains constant with time.Peer Reviewe

Estudio en cultivo sumergido de las fases de crecimiento y autólisis del hongo Coriolus versicolor

2 páginas, 1 tabla, 7 referencias.-- Trabajo presentado al citado Congreso, celebrado del 6-10 de septiembre 1983, en Valladolid, España.-- El libro consta de 574 páginas.Peer reviewe