X-ray diffraction and electrochemical impedance spectroscopy study of zinc coated LiNi0.5Mn1.5O4 electrodes

Coating and doping with zinc have been used to modify LiNi_0.5Mn_1.5O₄ powders prepared at 700 and 800 °C. As previously found in the literature, surface treatment with zinc leads to a net improvement of the electrochemical performance of the 5-V electrode in lithium cells. X-ray diffraction reveals the occurrence of surface ZnO, which disappears after heating at 500 °C. This indicates that ZnO forms a coating, although zinc can also be incorporated in the LiNi_0.5Mn_1.5O₄ framework. The electrochemical oxidation of both bare LiNi_0.5Mn_1.5O₄ and zinc treated products has been followed by ex situ X-ray diffraction of charged electrodes. For both materials a decrease in the cubic unit cell parameter and the formation of two cubic phases during lithium extraction has been found. Lattice contraction is significantly larger in the sample modified with zinc. EIS measurements give direct evidence of the better stabilization of the electrode surface in the coated material.     

Valoración del paciente que solicita muerte asistida

Resumen El equipo médico debe estar preparado para evaluar a los pacientes que solicitan muerte asistida. En esta revisión hemos recopilado de la literatura internacional los criterios médicos y psicológicos para evaluar a los pacientes que solicitan muerte asistida con la finalidad de aliviar las necesidades fisicas, psicológicas y sociales de los pacientes y sus familias. Se realizó un estudio de tipo exploratorio seleccionando los artículos que propusieran protocolos de valoración psicológica y médica de los pacientes que solicitan muerte asistida. Se analizó qué aspectos son los que se evalúan con mayor frecuencia en la literatura internacional. Se identificaron dos posturas generales para la valoración del paciente: por un lado la valoración de su competencia para la toma de decisiones y por otro la valoración del sufrimiento físico, seguido por el sufrimiento psicológico, social, existencial/espiritual, la relación médico-paciente y la relación médico-familiares. Finalmente se enumeran una serie de principios que pueden guiar al clínico ante la petición de muerte asistida.      

Patterns of reactivity to lipid transfer proteins of plant foods and Artemisia pollen: an in vivo study

BACKGROUND: Lipid transfer proteins (LTPs) are major allergens of Rosaceae fruits in the Mediterranean area. IgE-cross-reactivity has been demonstrated in vitro among LTPs from peach, apple, chestnut and Artemisia pollen. The aim of this study was to evaluate the reactivity to LTPs from peach, apple, chestnut and Artemisia pollen by means of skin prick tests (SPTs). METHODS: Forty-seven patients allergic to peach (peach group), 20 patients sensitized to Artemisia pollen with no food allergies (Artemisia group), and 12 control subjects were skin tested with fresh peach, as well as with whole extracts and purified LTPs of peach, apple, chestnut and Artemisia pollen. RESULTS: The rates of positive SPTs for peach, apple, chestnut and Artemisia LTPs were, respectively, 91, 77, 23, and 36% in the peach group, and 30, 5, 15 and 40% in the Artemisia group. No response was observed in the control subjects. SPTs with peach LTP strongly correlated with SPTs conducted with fresh peach. In the peach group, the most frequent pattern of reactivity to LTPs was the combination peach-apple (45%), followed by peach-apple-Artemisia-chestnut (21%). Significant correlations were found between peach and apple LTPs, and between Artemisia and chestnut LTPs. Positive SPTs to chestnut LTP were only observed in patients with positive SPTs to Artemisia LTP. All the patients with positive case histories to chestnut reacted to chestnut LTP. CONCLUSIONS: LTPs are plant panallergens with different patterns of cross-reactivity. They are major allergens of Rosaceae fruits and seem to be involved in allergic reactions to unrelated foodstuffs such as chestnut, probably through sensitization to the cross-reactive Artemisia LTP. Rosaceae LTPs could be useful tools for in vivo diagnosis of Rosaceae fruit allergy.     

Hepatic arterial variations and liver-related diseases of 100 consecutive donors

We prospectively studied anatomical variations and diseases of the liver in 100 consecutive donor operations during a period of 1 year. The normal arterial anatomy with a single hepatic artery (HA) from the celiac trunk was seen in 76% of all cases. Seven of twelve different major variations of the HA may be considered as rare, one of which cannot be found in the earlier literature. During harvesting, 6% of the livers were discarded, 3% on the basis of infection and 1% because of a polycystic disease. Two cases were rejected as the liver was found to be severely hypoperfused or hypoxic in an otherwise stable donor. Severe steatosis was macroscopically and histologically diagnosed in 3% of the cases, and in three donors a benign tumour was found in the liver or in the gall bladder. Two primarily nonfunctioning livers in the present series of 94 recipient operations were retrieved from this group of severely steatotic livers. As the donor liver was totally normal in only 2 out of 3 of the cases, the present study underlines the importance of searching for extremely variable anomalies of the HA and for liver-related diseases during organ harvesting.     

Plasma level monitoring of oxcarbazepine in epileptic patients

BACKGROUND: Despite the wide use of oxcarbazepine (OXC) there is little data concerning the usefulness of plasma level monitoring with this drug in Mexican patients with epilepsy. The purpose of the present study was to determine whether OXC levels correlate with dose, age, weight, or drugs used concomitantly. METHODS: Plasma levels of the antiepileptic drug OXC were evaluated in 214 patients with epilepsy. In each patient, plasma MHD (10-hydroxycarbazepine, the main metabolite of OXC) concentration was determined. Additionally, plasma protein binding was determined in 30 patients and affinity to red blood cells (RBCs) was evaluated in 50 patients. RESULTS: Our results showed that the mean plasma level of MHD was 15.34 microg/mL, mean protein binding ranged between 30-40%, and the mean RBC concentration was 18.38 microg/mL. A relationship between dose/weight and plasma concentration was found (r = 0.5149, p <0.001). In addition, a linear relationship between plasma and RBC concentration was established (r = 0.8806, p <0.0001). CONCLUSIONS: These results suggest that for OXC, routine RBC concentrations are not necessary to make drug adjustments.     

Tissue microarray: an effective high-throughput method to study the placenta for clinical and research purposes.

OBJECTIVE: Tissue microarray (TMA) technology allows simultaneous examination of the expression of many molecular markers (protein, mRNA, DNA, etc.) with high-throughput. The application of this technology, to date, has been largely confined to the study of cancer. Placental pathology poses unique challenges because of the size of the organ, its complex anatomy, as well as its histological heterogeneity. The objective of this study was to assess the feasibility and efficiency of TMAs for immunohistochemistry and in situ hybridization of placental tissues. STUDY DESIGN: TMAs were constructed using an automated tissue arrayer. Standard 0.6-mm or 1-mm microarray needles were used. Villous parenchyma, basal plate, and chorioamniotic membranes were targeted in each block. Five mum-thick TMA sections underwent immunohistochemical analysis of both cytoplasmic and nuclear antigens using a panel of antibodies against a variety of cytoplasmic [cytokeratin-7, vascular endothelial growth factor (VEGF), and protein Z], membranous (endoglin), and nuclear (c-fos and c-jun) antigens. mRNA in situ hybridization for surfactant protein A (SP-A) and chromogenic in situ hybridization for the Y chromosome (DYZ1) were also performed. RESULTS: Validation of TMA immunoreactivity demonstrated comparable results with corresponding whole sections. When a two-tiered scoring system (positive/negative) was employed, there was agreement between two and three cores and whole tissue sections (kappa>0.7). When a three-tiered scoring system (negative, weak-positive, or strong-positive) was used, the data from three cores showed the highest agreement with whole tissue sections (kappa >0.7). In situ hybridization experiments for mRNA and DNA were also successful in that the signals were readily detectable. Successful transfer from the donor block to the recipient block differed according to the anatomical compartment. The transfer efficiency of villous parenchyma, basal plate, and chorioamniotic membranes were 96.9% (875/903), 76.7% (115/150), and 75.4% (224/297), respectively. CONCLUSION: TMA is a practical and effective tool for high-throughput molecular analysis of the human placenta. Duplicate and triplicate cores offer agreement with whole tissue sections for two-category distinction immunostaining. TMA also affords relevant results from in situ hybridization experiments for mRNA and DNA. The major advantages are the conservation of tissues and reagents, simultaneous comparison of molecular markers in different anatomical compartments of the placenta, and reduction of experimental error.