Utility of two biomarkers for directing care among patients with non-severe community-acquired pneumonia.

The aim of the present study is to evaluate the usefulness of two biomarkers-procalcitonin (PCT) and C-reactive protein (CRP)-in addition to the CURB-65 score for assessing the site of care and the etiology of non-severe community-acquired pneumonia (CAP). We conducted a prospective observational study from April 1, 2006, to June 30, 2007, in a single teaching hospital in northern Spain among patients with non-severe CAP. In addition to collecting data needed to determine the CURB-65 score, microbial cultures were taken and levels of PCT and CRP were measured. We compared the prognostic accuracy of these biomarkers with the CURB-65 score to predict hospitalization and microbial etiology using receiver operating characteristic (ROC) curves. A total of 344 patients with non-severe CAP were enrolled; 73 were admitted to the hospital and 271 were treated on an outpatient basis. An etiologic diagnostic was made for 44 %, with atypical pathogens predominating. Levels of PCT and CRP increased with increasing CURB-65 scores. Patients admitted to the hospital had higher PCT and CRP levels than outpatients (p < 0.001). For predicting hospitalization, PCT had a better area under the ROC curve (AUC) (0.81) than the CURB-65 score alone (0.77). For PCT plus the CURB-65 score, the AUC increased significantly from 0.77 to 0.83. In patients with bacterial CAP, the biomarker levels were significantly higher than among patients with atypical or viral etiology (p < 0.001). PCT with a cut-off point of 0.15 ng/mL was the best predictor for bacterial etiology and for select patients eligible for outpatient care. In conclusion, levels of PCT and CRP positively correlate with increasing severity of CAP and may have a role in predicting both patients who can safely receive outpatient care and the microbial etiology in patients with low CURB-65 scores.

Influence of gamma irradiation on carbon nanotube-reinforced polypropylene.

Single walled carbon nanotubes (SWNT) have been incorporated into a polypropylene (PP) matrix in different concentrations (range: 0.25-2.5 wt%). The nanotubes were blended with PP particles (approximately 500 microm in size) before mixing in an extruder. Finally, rectangular plates were obtained by compression moulding. PP-SWNT composites were gamma irradiated at different doses, 10 and 20 kGy, to promote crosslinking in the matrix and potentially enhance the interaction between nanotubes and PP. Extensive thermal, structural and mechanical characterization was conducted by means of DSC, X-ray diffraction, Raman spectroscopy, uniaxial tensile tests and dynamic mechanical thermal (DMTA) techniques. DSC thermograms reflected higher crystallinity with increasing nanotube concentration. XRD analysis confirmed the only presence of a monoclinic crystals and proved unambiguously that CNTs generated a preferred orientation. Raman spectroscopy confirmed that the intercalation of the polymer between bundles is favored at low CNTs contents. Elastic modulus results confirmed the reinforcement of the polypropylene matrix with increasing SWNT concentration, although stiffness saturation was observed at the highest concentration. Loss tangent DMTA curves showed three transitions for raw polypropylene. While gamma relaxation remained practically unchanged in all the samples, beta relaxation temperatures showed an increase with increasing CNT content due to the reduced mobility of the system. Gamma-irradiated PP exhibited an increase in the beta relaxation temperature, associated with changes in glass transition due to radiation-induced crosslinking. On the contrary, gamma-irradiated nanocomposites did not show this effect probably due to the reaction of radiative free radicals with CNTs.

Wear resistance of highly cross-linked and remelted polyethylenes after ion implantation and accelerated ageing.

Ion implantation may provide medical polyethylenes with excellent mechanical and tribological properties, helping to lower the risk of long-term osteolysis. Highly crosslinked and remelted polyethylenes, materials currently used as soft components in artificial joints, were implanted with N+ and He+ ions at different ion fluences. The mechanical and tribological properties under distilled water lubrication at body temperature were assessed after ion implantation by means of microhardness and pin-on-disc tests respectively. Thus, the influences of the ionic species and implantation dose on surface hardness, friction coefficient, and wear factor were fully characterized. Furthermore, the tribological behaviour was evaluated after an accelerated ageing protocol (120 degrees C for 36h). Ion implantation increased the surface hardness, as well as friction coefficients, and decreased the wear factors especially at the highest doses. Also, even though all artificially aged materials showed a worse wear behaviour, polyethylenes implanted with either N+ or He+ at the highest doses maintained a relatively good wear factor in comparison with the aged non-implanted material. The origins of these modifications are discussed according to the effects of ion implantation on the microstructure of the polymer.

Evaluación de gravedad en pacientes agudos / Evaluation of severity in acute patients

Severity meaning the risk of adverse outcomes, death or disability, varies along disease's characteristics and patient related factors. Its evaluation is complex and besides subjective perception several, more objective, clinical tools exist along with laboratory data that independently or used in combination, allows the clinician to approach severity of a given patient's condition or a particular disease. We will review several aspects of the evaluation of severity, clinical and laboratory based in addition of some scoring systems, emphasizing perfusion and organ dysfunction evaluation as key elements to assess severity particularly in critical situations. (AU)

Influence of the remelting process on the fatigue behavior of electron beam irradiated UHMWPE.

Electron beam irradiation at doses below 150 kGy is a widely used technique to obtain highly crosslinked ultra-high-molecular-weight polyethylene (UHMWPE). Its current use in total joint replacement components may improve wear resistance and decrease UHMWPE particle debris. However, currently used post-irradiation thermal treatments, which aim to decrease the free radicals within the material, introduce microstructural changes that affect UHMWPE mechanical properties, particularly the fatigue strength. This influence may be crucial in total knee replacements, where fatigue-related damage limits the lifespan of the prosthesis. Therefore, more studies are required to understand UHMWPE fatigue after current crosslinking protocols. This study was planned to evaluate the influence of UHMWPE remelting after irradiation on the material fatigue resistance. The remelting was achieved at 150 degrees C for 2 h on UHMWPE previously irradiated at 50, 100, and 150 kGy. Fatigue evaluation included short-term tests under cyclic tensile stress with zero load ratio, R = 0, and 1 Hz. In addition, stress-life testing was performed using 12% yield as the criterion for failure. Near-threshold fatigue crack propagation experiments were also performed at a frequency of 5 Hz, and crack length was measured in nonthermally treated and remelted irradiated UHMWPE. Crystallinity percentage was calculated from DSC measurements. The results pointed out that irradiation positively contributed to total life analysis, but the further remelting process decreased the flaw initiation resistance. On the other hand, both processes negatively affected the fatigue resistance of notched components. From a clinical point of view, the results suggest that the material fatigue behavior should be carefully studied in new UHMWPE to avoid changes related to material processing.

Fractography evolution in accelerated aging of UHMWPE after gamma irradiation in air.

We studied the fracture surface evolution of ultra high molecular weight polyethylene (UHMWPE) specimens, manufactured from GUR 1050 compression moulded sheets, after gamma sterilisation in air followed by different aging times after thermal treatment at 120 degrees C. Degradation profiles were obtained by FTIR and DSC measurements after 0, 7, 14, 24 and 36h aging. We observed by SEM the morphology patterns at these aging times, in surface fractographies after uniaxial tensile test of standardised samples. The results pointed out clear differences between short and long aging times. At shorter times, 7h, the behaviour was similar to non-degraded UHMWPE, exhibiting ductile behaviour. At longer times, 24-36h, this thermal protocol provided a highly degraded zone in the subsurface, similar to the white band found after gamma irradiation in air followed by natural aging, although closer to the surface, at 150-200mum. The microstructure of this oxidation zone, similarly found in gamma irradiated samples shelf-aged for 6-7 years, although with different distribution of microvoids, was formed by fibrils, associated with embrittlement of the oxidised UHMWPE. In addition, the evolution of the oxidation index, the enthalpy content, the mechanical parameters, and the depth of the oxidation front deduced from the fractographies versus aging time showed that a changing behaviour in the degradation rate appeared at intermediate aging times.

Comparative cyclic stress-strain and fatigue resistance behavior of electron-beam- and gamma-irradiated ultrahigh molecular weight polyethylene.

Fatigue-related damage in UHMWPE is one of the main causes of long-term failure in total joint replacements. Crosslinking ultrahigh molecular weight polyethylene (UHMWPE) by gamma or electron-beam irradiation, in combination with prior or further thermal treatment, enhances its wear resistance against metallic components in total hip replacements, and eventually in knees. However, little information is available on the fatigue response of this modified UHMWPE. The objective of this study was to compare electron-beam-irradiated UHMWPE at 50, 100, and 150 kGy, with the well-known 25 kGy gamma-irradiated UHMWPE. Two different cyclic tests were performed under tensile stress, with a zero load ratio, R = 0. First, specimens were subjected to a sinusoidal load cycle at 1 Hz, which provided stress-life curves with the use of a failure criterion based on 12% yield strain. Second, specimens were tested under 50 load cycles at a displacement rate of 15 mm/min, which provided information about the evolution of secant modulus and plastic strain. The incubation period was also analyzed. DSC measurements were carried out to check the crystallization effect of irradiation. According to the results of fatigue resistance there was a crossover behavior between gamma- and electron-beam-irradiated UHMWPE regarding the applied stress. When the stress was higher than the crossover value, the fatigue resistance of gamma-irradiated samples was higher than electron-beam-irradiated ones. When the stress was lower, the fatigue behavior was the opposite. The crossover stress depended on the electron-beam-irradiation dose. The clinical relevance of this study lies in an improved knowledge of electron-beam-irradiated material under extreme mechanical circumstances, such as fatigue.

[Immunologic response to testicular torsion. Experimental study on rats]. / Respuesta inmunológica a la torsión testicular. Trabajo experimental en ratas.

Men with a background of unilateral torsion of testis (t.t.) show a greater percentage of infertility and changes in the spermiogram. Currently, the cause of contralateral testicle affectation remains unknown. With the aim of verify whether these changes are secondary to an immunological mechanism, the authors conducted experimental work in 3 groups of male rats, inducing a right t.t. over 24 hours, followed by detorsion and preservation of contorted testicle. Immunological response is determined through direct and indirect immunofluorescence reactions, including a brief description of the technique used. Positive reactions were obtained in both the spermatozoa's head and flagellum, more frequently in animals killed at 30 days and gradually decreasing in those killed at 60 and 90 days. The authors compare their results to other experimental works, and recommend to perform orchiectomy because of the damaging effect of the contorted testicle over the contralateral one.

[Favorable effect of orchiectomy in unilateral testicular torsion on the exocrine function of the contralateral testis in rats]. / Efecto favorable de la orquiectomia tras torsion testicular unilateral sobre la funcion exocrina del testiculo contralateral en la rata.

The unilateral testicular torsion reflects in a negative manner on the contralateral testis. With the objective of proving if these alterations can be avoided, we used two groups of rats. The problem group was subjected to torsion with posterior orchiectomy. The control of spermatozoon we found significant differences for the spermatozoon with bigger motility. These results are from different from those obtained in animals submitted to testicular torsion with posterior distortion leaving the testis twisted. We think the orchiectomy has a prophylactic value upon the perturbation in the contralateral testis.

Microstructure, thermooxidation and mechanical behavior of a novel highly linear, vitamin E stabilized, UHMWPE.

A novel, vitamin E-stabilized, medical grade ultra-high molecular polyethylene, MG003 (DSM Biomedical; The Netherlands), has been very recently introduced for use in total joint replacements. This homopolymer resin features average molecular weight similar to that of conventional GUR 1050 resin (5.5-6*10(6)g/mol), but a higher degree of linearity. The aim of this study was to characterize the microstructure, thermal and thermooxidation properties as well as the mechanical behavior of this novel MG003 resin before and after gamma irradiation in air to 90 kGy. For this purpose, a combination of experimental techniques were performed including differential scanning calorimetry (DSC), thermogravimetry (TG), transmission electron microscopy (TEM), X-Ray Diffraction, electron paramagnetic resonance (EPR), and uniaxial tensile tests. As-consolidated MG003 materials exhibited higher crystalline contents (~62%), transition temperatures (~140 °C), crystal thickness (~36 nm), yield stress (~25 MPa) and elastic modulus (~400 MPa) than GUR 1050 controls (55%, 136 °C, 27 nm, 19 MPa, and 353 MPa, respectively). Irradiation produced similar changes in both MG003 and GUR 1050 materials, specifically increased crystallinity (63% and 60%, respectively), crystal thickness (39 nm and 30 nm), yield stress (27 MPa and 21 MPa), but, above of all, loss of elongation to breakage (down to 442 and 469%, respectively). Thermogravimetric and EPR results suggest comparable susceptibilities to oxidation for both MG003 and GUR 1050 polyethylenes. Based on the present findings, MG003 appears as a promising alternative medical grade polyethylene and it may satisfactorily contribute to the performance of total joint replacements.

Serum cystatin C and microalbuminuria in the detection of vascular and renal damage in early stages.

BACKGROUND: The aim of this study was to assess serum cystatin C and urinary albumin in the early detection of impairment in cardiovascular and renal function. MATERIAL ANS METHODS: Cystatin C was quantified in sera from healthy people, moreover, cystatin C was quantified in a group of patients diagnosed with chronic kidney disease for predicting a measured glomerular filtration rate <60 ml/min/1.73 m2. Finally serum cystatin C and microalbuminuria were measured in patients with increasing of risk of impairment in cardiovascular and renal function (hypertension, diabetes and hyperlipidemia). RESULTS: When the serum cystatin C was quantified in a group of risk, we observe as when being increased the cystatin C, the values of the glomerular filtration rate decreased (p <0.05), the cystatin values C were increased when increasing the age of the patients (p <0.05) and cystatin C values higher than 0.95 mg/l were not observed in patient smaller than 50 years old. In the group of risk, serum cystatin C was high regarding to the values obtained in healthy people in 27.6%, microalbuminuria in the 20.3% and both parameters were high in the 14.4% of patients with a glomerular filtration rate >90 ml/min/1.73 m2, while in patients with a glomerular filtration rate 60-90 ml/min/1.73 m2, cystatin C was high in the 51.7% and the microalbuminuria only in the 6.4%. CONCLUSIONS: Determinations of serum cystatin C associated to the quantification of urinary albumin in patients with cardiovascular risk can optimize the early detection of vascular and renal damage. Cystatin C can show vascular and renal damage in patients without urinary albumin.

[Basal study of exocrine testicular function in rats]. / Estudio basal de la función exocrina testicular en ratas.

There is currently no existing methodology for evaluating normal exocrine function in the healthy rat. Consequently, most of the experimental studies that have been conducted are incomplete. For this reason, we developed an experimental model to investigate the testicular exocrine function using spermatozoa obtained from the tail of the epididymis of male rats of different ages. The methodology is described and the results obtained relative to sperm count, survival time, percent mobile/immobile spermatozoa and presence of abnormal forms are presented and compared with the data from experimental studies using electroejaculation techniques. Similarly, the advantages and disadvantages of the method are discussed. In our view, the methodology described herein can also be utilized in other laboratory animals.

Vasorreactividad a adenosina en los pacientes con hipertensión pulmonar arterial: prevalencia y respuesta clínica, funcional y hemodinámica al tratamiento con diltiazem / Acute vasodilatador test using adenosine in patients with pulmonary arterial hypertension: prevalence and clinical, functional and hemodynamic response after diltiazem treatment

Pulmonary arterial hypertension (PAH) is a severe and progressive disease. Invasive hemodynamic study (HS) is required to confirm the diagnosis of PAH and to perform the vasodilator test (VT) with adenosine. Vasodilator acute responders (VAR) may have a sustained benefit with diltiazem. There is not national information regarding these issues. All patients with probable PAH were evaluated with HS and VT. VAR were treated with diltiazem and followed up with functional class score (FC) and 6 minute walk test. After 6 months, a second HS was performed. Results: Between 2003 and 2008, 6/54 (11%) were VAR. All were women, 45 +/- 14 years old, 4 with idiopathic PAH, 4 in FCIII and 2 in FCII. After two years of treatment, all patients clinically improved. Walked distance significantly increased by 83 and 87 m at month 12 and 24 respectively. Hemodynamic parameters also improved. Therapy with diltiazem is effective in VAR patients supporting the convenience to perform the VT.

La Hipertensión Pulmonar Arterial (HAP) es una entidad grave y progresiva. El estudio hemodinámica (EH) permite certificar el diagnóstico y evaluar la vasorreactividad mediante adenosina. Los pacientes vaso-reactivos podrían responder a terapia con diltiazem. No existe información nacional al respecto. En nuestro programa todo paciente con sospecha de HAP es sometido a EH diagnóstico y de vasorreactividad. Los positivos son tratados con diltiazem y seguidos semestralmente según capacidad funcional (CF) y con test de caminata. Al 6º mes se efectúa un 2º EH. Entre 2003-2008, 6/54 (11%) de los pacientes con HAP fueron vasorreactivos. Todas mujeres, 45 +/- 14 años, 4 con HPA idiopática, 4 en CFIII y 2 en CFII. A los 2 años, todos mejoraron clínicamente. La distancia recorrida aumentó significativamente en los meses 12 y 24 en 83 y 87 m respectivamente. Todas las variables hemodinámicas mejoraron. La terapia con diltiazem es efectiva en los pacientes vaso-reactivos lo que justifica usar el test de vasorreactividad.

Síndrome hepatopulmonar e hipertensión portopulmonar: dos entidades a diferenciar / Hepatopulmonary syndrome and portopulmonary hypertension: two distinct entities

The clinical course of patients with portal hypertension or liver disease may be complicated by two low prevalence entities with high morbimortality: the hepatopulmonary syndrome (HPS) and portopulmonary hypertension (PPHT). Each one is a consequence ofan impaired hepatic clearance of several vascular mediators, triggering vasodilation of the pulmonary vascular territory in HPS and vasoconstriction with vessel remodelation in PPHT. Both disorders have some similar clinical findings, but useful findings for differential diagnosis are the presence of platypnoea and orthodeoxia in HPS, and echocardiographic extracardiac and intrapulmonary shunt in HPS or pulmonary hypertension in PPHT. Currently, liver transplantation is the only effective treatment for both entities provided that indication and timing must be accurately evaluated. We present a review and three cases of both entities.

El curso clínico de los pacientes con cirrosis y/o hipertensión portal puede verse complicado por dos entidades de baja prevalencia pero de elevada morbimortalidad, que corresponden al síndrome hepatopulmonar (SHP) y la hipertensión portopulmonar (HPP). Ambas se presentan a consecuencia de un déficit en la depuración hepática de diversos mediadores vasculares, provocando en el territorio pulmonar una vasodilatación en el SHP y una vasoconstricción con remodelación vascular en la HPP. Si bien estas entidades comparten algunos aspectos clínicos, resulta útil en su diferenciación la presencia de platipnea y ortodeoxia y el hallazgo ecocardiográfico de un shunt extracardíaco e intrapulmonar en el SHP, o de hipertensión pulmonar en HPP. Hasta el momento la única terapia efectiva para ambas entidades es el trasplante hepático, cuya indicación exige una evaluación rigurosa y oportuna. Se presenta una revisión y tres casos clínicos de ambas entidades.

Síndrome POEMS: reporte de un caso clínico / POEMS syndrome: report of a clinical case

El síndrome POEMS se caracteriza por la presencia de Polineuropatía, Organomegalia, Endocrinopatía, Gammapatía Monoclonal y Cambios en la Piel. Muchas otras manifestaciones clínicas del síndrome no están incluidas en este acrónimo, como las lesiones óseas osteoescleróticas, edema de papila, sobrecarga de volumen extravascular, trombocitosis, policitemia, acropaquia, hipertensión pulmonar, baja de peso, fatiga, diarrea, compromiso renal y artralgias. Es una patología infrecuente, de mayor prevalencia en varones, con una relación 2:1, preferentemente entre la quinta y sexta década de la vida. Es una enfermedad de curso crónico y tiene sobrevida promedio de 13,8 años en algunas series. La patogenia es desconocida y no existe en la actualidad consenso respecto al tratamiento ni estudios randomizados y controlados que comparen los resultados de diferentes terapias en esta enfermedad.

POEMS syndrome is characterized by the presence of Polyneuropathy, Organomegaly, Endocrinopathies, Monoclonal Gammopathy and Skin changes. Many other clinical manifestations of the syndrome are not included in this acronym, as the osteosclerotic lesions, papillary edema, extravascular volume overload, thrombocytosis, polycythemia, acropaquia, pulmonary hypertension, weight loss, fatigue, diarrhea, arthralgia, and renal involvement. It is an infrequent disease, more prevalent in males with a 2:1 ratio, mostly between the fifth and sixth decades of life. It has a chronic course with an average survival of 13.8 years in some series. The pathogenesis is unknown and currently there is no consensus regarding the treatment or randomized controlled studies comparing the outcomes of different therapies in this disease.

Trasplante de médula ósea en pacientes pediátricos / Paediatric bone marrow transplantation

Objetivo: el transplante de médula ósea (TMO) es un procedimiento que constituye la única posibilidad de tratamiento para algunas enfermedades hematológicas y oncológicas de la infancia. Se describe un programa de trasplante de médula ósea implementado en nuestra institución, habilitando la infraestructura y personal necesarios. Pacientes: 60 pacientes pediátricos han recibido TMO, 37 niños, 23 niñas, edades entre 7 meses y 17 años. Los diagnósticos correspondieron a leucemia aguda 24, aplasia medular 5, leucemia mieloide crónica/mielodisplasia 6, tumores sólidos 17, enfermedades congénitas 7, histiocitosis 1. Fueron TMO autólogos 14 casos y alogeneicos 46. Donantes: hermanos idénticos: 34. Familiares no idénticos: 6. Cordón umbilical no relacionado: 6. Correspondieron a grupo de riesgo estándar 31 pacientes, y grupo de riesgo alto (leucemias o tumores refractarios, pacientes politransfundidos, donantes no hermano), 29. Resultados: sobrevida actuarial libre de eventos (a 3 años): grupo total: 36 por ciento, grupo riesgo estándar: 61 por ciento, grupo riesgo alto: 10 por ciento (p < 0,01). Conclusiones el TMO es un tratamiento efectivo para pacientes pediátricos sin otra alternativa terapéutica. Los resultados en pacientes con enfermedad muy avanzada son malos, apoyando la necesidad de realizar oportunamente el procedimiento