Blood concentrations of calcium, phosphorus and magnesium and dietary cation-anion difference in dairy cows / Concentrações sanguíneas de cálcio, fósforo e magnésio e diferença cátion-ânion da dieta de vacas leiteiras

The objective of this study was to identify the effect of pre and postpartum DCAD on serum levels of calcium, phosphorus, and magnesium in peripartum Holstein cows. Blood samples were collected from 56 cows (18 primiparous and 38 multiparous) on days -7, +7, +14 and +28 relative to parturition, to determine serum levels of total and ionized calcium, phosphorus, magnesium, and albumin; diet samples for determination of calcium, phosphorus, magnesium and DCAD were collected at the same moments and urine samples were collected at day -7 for measurement of urinary pH. Prepartum DCAD was positively correlated with total calcium (p = 0.02) and with corrected total calcium (p = 0.01) at day -7. There was a negative correlation between prepartum DCAD and magnesium levels at day -7 (p = 0.02). No influence of prepartum DCAD on phosphataemia was observed. Postpartum DCAD did not correlate with serum mineral levels at any time point. Our results demonstrate that prepartum DCAD can influence calcium and magnesium homeostasis, but not phosphorus. In addition, parity and time period should be considered when evaluating serum levels of these minerals in Holstein cows during transition period.

Objetivou-se identificar o efeito da DCAD pré e pós-parto nos níveis séricos de cálcio, fósforo e magnésio, em vacas Holandesas em periparto. Foram coletadas amostras de sangue de 56 vacas (18 primiparas e 38 multiparas) nos dias -7, +7, +14 e +28 em relação ao parto, para determinação dos níveis séricos de cálcio total e ionizado, fósforo, magnésio e albumina; amostras de alimento foram coletadas nos mesmos momentos para determinação dos níveis cálcio, fósforo, magnésio e DCAD dietético; e amostras de urina foram coletadas no dia -7, para mensuração do pH urinário. A DCAD pré-parto foi positivamente correlacionada com cálcio total (P = 0,02) e com cálcio total corrigido (P = 0,01) no dia -7. Houve correlação negativa entre a DCAD pré-parto e os níveis de magnésio no momento -7 (P = 0,02). Não houve influência da DCAD pré-parto na fosfatemia. A DCAD pós-parto não se correlacionou com os níveis séricos de minerais em nenhum momento. Os resultados demonstram que a DCAD pré-parto pode influenciar na homeostase do cálcio e do magnésio, mas não do fósforo. Além disso, as variáveis paridade e tempo devem ser consideradas ao se avaliarem os níveis séricos desses minerais em bovinos leiteiros da raça Holandesa em transição.

Which model of small bowel capsule endoscopy has a better diagnostic yield? A systematic review and meta-analysis.

Background and study aims: Small-bowel capsule endoscopy (SBCE) is a safe and efficient method for diagnosis of small-bowel diseases. Since its development, different models have appeared. The aim of this study was to analyze which of the different models of SBCE has the best diagnostic yield. Patients and methods: Extensive medical literature research was reviewed, using MESH terms, searching studies comparing different SBCE types. We analyzed the diagnostic yield of all the comparisons and when there were 2 or more studies that compared the same model of SBCEs, a meta-analysis was performed. Results: Ten eligible studies including 1065 SBCEs procedures were identified. The main indication was occult gastrointestinal bleeding in 9/10 studies. Two of them included anemia, chronic diarrhea and/or chronic abdominal pain. The indication in one article was celiac disease. In 9 studies, different types of SBCEs (MiroCam, Endocapsule, OMOM and CapsoCam) were compared with PillCam (SB, SB2 and SB3). Three studies compared MiroCam vs PillCam and CapsoCam vs PillCam, while two studies contrast Endocapsule vs PillCam. None of the SBCEs show superiority over PillCam [OR 0.78 (95%CI;0.60-1.01)]. One study compared SBCEs other than Pillcam (MiroCam vs Endocapsule). Nine studies did not find statistical differences between SBCEs, one showed better diagnostic yield of Mirocam compared with PillCam SB3 (p=0.02). The difference between these SBCE was not replayed in the metaanalysis [OR 0.77 (95%CI;0.49-1.21)]. Conclusions: Despite the appearance of new SBCE models, there are no differences in diagnostic yield; therefore, SBCE endoscopist's performance should be based on experience and availability.

Analysis of body condition indices reveals different ecotypes of the Antillean manatee.

Assessing the body condition of wild animals is necessary to monitor the health of the population and is critical to defining a framework for conservation actions. Body condition indices (BCIs) are a non-invasive and relatively simple means to assess the health of individual animals, useful for addressing a wide variety of ecological, behavioral, and management questions. The Antillean manatee (Trichechus manatus manatus) is an endangered subspecies of the West Indian manatee, facing a wide variety of threats from mostly human-related origins. Our objective was to define specific BCIs for the subspecies that, coupled with additional health, genetic and demographic information, can be valuable to guide management decisions. Biometric measurements of 380 wild Antillean manatees captured in seven different locations within their range of distribution were obtained. From this information, we developed three BCIs (BCI1 = UG/SL, BCI2 = W/SL3, BCI3 = W/(SL*UG2)). Linear models and two-way ANCOVA tests showed significant differences of the BCIs among sexes and locations. Although our three BCIs are suitable for Antillean manatees, BCI1 is more practical as it does not require information about weight, which can be a metric logistically difficult to collect under particular circumstances. BCI1 was significantly different among environments, revealing that the phenotypic plasticity of the subspecies have originated at least two ecotypes-coastal marine and riverine-of Antillean manatees.

Double-balloon enteroscopy: Indications, approaches, diagnostic and therapeutic yield, and safety. Early experience at a single center. / Enteroscopia de doble balón: indicaciones, abordajes, eficacia diagnóstica y terapéutica y seguridad. Experiencia temprana de un solo centro.

INTRODUCTION AND AIMS: Double-balloon enteroscopy has been improving the visualization of the entire intestine for more than a decade. It is a complementary method in the study of intestinal diseases that enables biopsies to be taken and treatments to be administered. Our aim was to describe its main indications, insertion routes, diagnostic/therapeutic yield, and complications. MATERIALS AND METHODS: All patients referred to our unit with suspected small bowel pathology were included. The insertion route (oral/anal) was determined through diagnostic suspicion. The variables measured were: insertion route, small bowel examination extent, endoscopic diagnosis/treatment, biopsy/histopathology report, complications, and surgical findings. RESULTS: The study included 28 double-balloon enteroscopies performed on 23 patients, of which 10 were women and 13 were men (mean age of 52.95 years). The oral approach was the most widely used (n=21), the main indication was overt small bowel bleeding (n=16), and the general diagnostic yield was 65.21%. The therapeutic intervention rate was 39.1% and the procedure was effective in all the cases. The most widely used treatment was argon plasma therapy (n=7). The complication rate was 8.6%; one patient presented with low blood pressure due to active bleeding and another had deep mucosal laceration caused by the argon plasma. CONCLUSIONS: Double-balloon enteroscopy is a safe and efficacious method for the study and management of small bowel diseases, with an elevated diagnostic and therapeutic yield.

Hidden sources of mercury in clinical laboratories.

The healthcare sector is an important contributor to mercury (Hg) pollution because of the potential presence of mercury in thermometers, blood pressure cuffs, amalgams, etc. There are also other potential sources of mercury in this sector which are used frequently and in high volumes where the presence of the metal is not obvious and which might be collectively contributing to pollution. For instance, some chemicals used for the clinical diagnosis of illness may contain mercury. The goal of this study was to investigate potential sources of mercury pollution, which originate from clinical laboratory discharges, using an exploratory approach. The focus was on the residue generated during automatic analysis of patients' bodily fluids at a medical center in Hermosillo, Sonora, Mexico. This study shows an overview of what might be happening in the region or the country related to non-obvious sources of mercury in the healthcare sector. The results showed measurable levels of mercury in the residues coming from urine sediment analysis. These amounts do not exceed the maximum allowed by Mexican environmental regulations; nevertheless, the frequency and cumulative volume of residues generated, combined with the potential for persistence and the bioaccumulation of mercury in the environment, warrant attention. The work carried out in this study is being taken as a model for future studies for pollution prevention in the healthcare sector with the goal of measuring mercury emissions to the environment from clinical laboratory wastewater, including identifying sources which--while not obvious--could be important given the frequency and volume of their use in the clinical diagnosis.

Modelo de instilación intra-traqueal de jugo gástrico en la rata: curso temporal de las alteraciones histológicas / Intra-tracheal instillation of gastric juice in the rat: time course of histological changes

Introduction: Aspiration of gastric content is associated with a wide range of clinical conditions (acute lung injury, severe interstitial pneumonia or bronchiolitis obliterans following lung transplantation). Objective: To study the course of histological alterations in a model of intra-tracheal instillation of gastric juice in rats. Methods: Anesthetized rats were euthanized at different times: 4, 12 and 24 hours and 4 and 7 days after intratacheal (IT) instillation of gastric juice. Animals that were not intervened served as controls. The right inferior lobe was studied (H-E) and a histological injury score was given according to a recently published score system. Results: Between 4-24 h an inflammatory-hemorragic pattern with bronchiol-centric distribution was characterized by a large proportion of neutrophils in both alveoli and interstitium, alveolarfluid accumulation, proteinaceous material andfew hyaline membranes. Between 4 and 7 days, mononuclear cells were more prevalent, the hemorrhagic component disappeared, the percentage of abnormal bronchioles was significantly reduced and there was organization of the alveolar infiltrate, with Masson bodies, granulomas and giant cells associated with gastric juice particles. Conclusions: In rats, IT instillation of gastric juice induces diffuse alveolar damage that evolves towards an early granulomatous interstitial pneumonia along with lax fibrous tissue. Knowledge of the temporary course of the pulmonary responses helps to the understanding of the consequences of the several clinical conditions that favor gastric content aspiration.

Introducción: La aspiración de contenido gástrico se asocia con diversas condiciones clínicas (daño pulmonar agudo, neumonía intersticial severa o bronquiolitis obliterante post-trasplante). Objetivo: Estudiar el curso de las alteraciones histológicas en un modelo de instilación intra-traqueal (IT)de jugo gástrico en ratas. Métodos: Ratas anestesiadas recibieron vía ITjugo gástrico de un pool obtenido previamente. Los animales fueron sacrificados a las: 4, 12 y 24 h y 4 y 7 días post-instilación. Animales sin intervención sirvieron como controles. El lóbulo inferior derecho fue estudiado (H-E) para la asignación de un puntaje de daño histológico de acuerdo a un sistema de puntuación recientemente publicado. Resultados: Entre 4-24 h se observó un patrón inflamatorio-hemorrágico de distribución bronquíolo-céntrica, con predominio de neutrófilos intersticiales y alveolares, edema, material proteináceo alveolar y escasas membranas hialinas. Entre los 4 y 7 días, se observó predominio mononuclear y desaparición del componente hemorrágico, se redujo significativamente el porcentaje de bronquíolos afectados y se observó organización del infiltrado inflamatorio, con cuerpos de Masson, granulomas y células gigantes asociadas a partículas del jugo gástrico. Conclusiones: En ratas, la instilación IT de jugo gástrico induce daño alveolar difuso que progresa hacia una neumonía intersticial granulo-matosa temprana con tejido fibroso laxo. El conocimiento del curso de la respuesta pulmonar en este modelo, contribuye a comprender las posibles consecuencias de las condiciones clínicas que favorecen la aspiración de contenido gástrico.

Exploring the possible role of lysine acetylation on Entamoeba histolytica virulence: a focus on the dynamics of the actin cytoskeleton.

Cytoskeleton remodeling can be regulated, among other mechanisms, by lysine acetylation. The role of acetylation on cytoskeletal and other proteins of Entamoeba histolytica has been poorly studied. Dynamic rearrangements of the actin cytoskeleton are crucial for amebic motility and capping formation, processes that may be effective means of evading the host immune response. Here we report the possible effect of acetylation on the actin cytoskeleton dynamics and in vivo virulence of E. histolytica. Using western blot, immunoprecipitation, microscopy assays, and in silico analysis, we show results that strongly suggest that the increase in Aspirin-induced cytoplasm proteins acetylation reduced cell movement and capping formation, likely as a consequence of alterations in the structuration of the actin cytoskeleton. Additionally, intrahepatic inoculation of Aspirin-treated trophozoites in hamsters resulted in severe impairment of the amebic virulence. Taken together, these results suggest an important role for lysine acetylation in amebic invasiveness and virulence.

Src and PI3 K inhibitors affect the virulence factors of Entamoeba histolytica.

Protein kinases (PKs) of parasitic protozoa are being evaluated as drug targets. A large number of protein kinases within the protein kinome of Entamoeba histolytica strongly suggest that protein phosphorylation is a key component of pathogenesis regulation by this parasite. PI3 K and Src are kinases previously described in this parasite, but their role is poorly understood. Here, the effect of Src-1-inhibitor and PI3 K inhibitor (Wortmannin) on the virulence factors of E. histolytica was evaluated. Results show that both inhibitors affect the actin cytoskeleton and the amoebic movement. Also, the proteolytic activity is diminished by Wortmannin, but not by Src-inhibitor-1; however, the phagocytic capacity is diminished by Wortmannin and Src-1-inhibitor. Finally, we found that the virulence in vivo of E. histolytica is affected by Wortmannin but not by Src-1-inhibitor. This study opens the way for the design of anti-amoebic drugs based on kinase inhibition.

Methane potential and biodegradability of rice straw, rice husk and rice residues from the drying process.

Agricultural solid residues are a potential renewable energy source. Rice harvesting and production in Sancti Spíritus province, Cuba, currently generates residues without an environmentally sustainable disposal route. Rice residues (rice straw, rice husk and rice residues from the drying process) are potentially an important carbon source for anaerobic digestion. For this paper, rice residues were placed for 36 days retention time in anaerobic batch reactor environments at both mesophilic (37 °C) and thermophilic (55 °C) conditions. Biogas and methane yield were determined as well as biogas composition. The results showed that rice straw as well as rice residues from the drying process had the highest biogas and methane yield. Temperature played an important role in determining both biogas yield and kinetics. In all cases, rice straw produced the highest yields; under mesophilic conditions the biogas yield was 0.43 m(3) kg(VS)(-1), under thermophilic conditions biogas yield reached 0.52 m(3) kg(VS)(-1). In the case of the rice husk, the biodegradability was very low. Methane content in all batches was kept above 55% vol. All digested material had a high carbon:nitrogen (C:N) ratio, even though significant biodegradation was recorded with the exception of rice husk. A first-order model can be used to describe the rice crop residues fermentation effectively.

Chemical composition of ice pops produced in a microindustry from hidalgo, Mexico / Composición quimica de paletas congeladas producidas en una microindustria de hidalgo, México

The chemical composition of water and milk based ice pops produced by a microindustry in Hidalgo, Mexico were determined. Fifteen samples of several flavors were analyzed. The proximate composition was carried out according AOAC techniques. The identification and quantification of fatty acids in the milk based ice pops was performed by Gas Chromatography provided with a flame ionization detector. Water based ice pops did not present a significant nutritional value. Regarding milk based ice pops all samples contained from 6.83 to 12.7% offat and some samples showed interesting contents of protein (3.55 and 4.21%). The fatty acid profile revealed higher contents of unsaturated fatty acids compared with saturated fatty acids. Trans fatty acids were detected in five of seven milk based samples, representing 20-60% of total fatty acids. Analysis showed that the mixes used to prepare ice pops are different according to their flavor, kind, and amount of fruit which alters their nutritional value and the levels of trans-fatty acids.

Se determinó la composición química de paletas congeladas, en base agua y en base láctea, producidas por una microindustria en Hidalgo, México. Se analizaron quince muestras de diferentes sabores. La composición proximal se llevó a cabo de acuerdo a las técnicas de la AOAC. La identificación y cuantificación de ácidos grasos en las paletas base láctea se realizó por cromatografía de gases con detector de ionización de llama. Las paletas base agua no presentaron un valor nutricional significativo. Con respecto a las paletas base láctea, se observaron contenidos de grasa de 6.83 a 12.7%; algunas presentaron valores interesantes de proteína (3.55 y 4.21%). El perfil de ácidos grasos reveló altos contenidos de ácidos grasos insaturados comparados con los saturados. Cinco de las siete paletas de base láctea analizadas presentaron ácidos grasos trans, representando 20-60% del total de ácidos grasos. Los análisis realizados han mostrado que las mezclas usadas para preparar las paletas son diferentes de acuerdo a su sabor, tipo y cantidad de fruta la cual modifica el valor nutricional y el nivel de ácidos grasos trans.

[Tripeptidyl peptidase 1 in patients with late infantile neuronal ceroid lipofuscinosis]. / Tripeptidil peptidasa 1 en pacientes con ceroidolipofuscinosis neuronal infantil tardía.

INTRODUCTION: Neuronal ceroid lipofuscinoses are a group of inherited autosomal recessive lysosomal diseases, most commonly found in infancy. These are neuropathologically characterised by accumulation of an autofluorescent lipopigment in neurons and other cells. This condition is clinically characterised by loss of motor and cognitive skills, lack of motor coordination, ataxia, progressive visual impairment, behavioural changes; seizures of difficult to manage seizures, particularly myoclonic, and premature death. Ten clinical forms have been described, one of which is late infantile where clinical signs begin between two and four years. The gene responsible for this disease is located at 11p15 locus, and the enzyme encoded by this gene is the tripeptidyl peptidase 1. PATIENTS AND METHODS: We standardised the technique for the enzymatic diagnosis of late infantile neuronal ceroid lipofuscinoses from dried blood on filter paper card in 76 healthy individuals adults and children in order to establish a normal range in the Venezuelan population. The tripeptidyl peptidase activity was also determined in 9 patients with a clinical diagnosis of late infantile neuronal ceroid lipofuscinoses. RESULTS: Six of the samples showed activity lower than the lowest control value (0.11 to 0.45 nmol/spot) from healthy controls of infantile age, confirming the enzymatic diagnosis. Three of the 14 parent samples analysed showed values in the heterozygote ranges. CONCLUSIONS: The enzymatic diagnosis of late infantile neuronal ceroid lipofuscinoses from dried blood on filter paper card is a rapid, easier, less expensive and accurate molecular diagnosis tool.

AUMENTO DEL CONTENIDO PROTEICO DE UNA BEBIDA A BASE DE AMARANTO (Amaranthus hypochondriacus) / INCREASING THE PROTEIN CONTENT OF AN AMARANTH (Amaranthus hypochondriacus) DRINK

The aim of this work was to increase the protein content ofan amaranth drink (Amarantole) with different proteins sources (chickpea, pea, lacto serum, powdered milk and soybean milk). Different mixtures of Amarantole-protein mix were prepared in four proportions (80:20,75:25,70:30 and 60:40). The best mixtures were selected according to the increase in the protein content and its sensory characteristics assayed by using degree of liking, preference and ranking test. Chemical and mineral composition was determined according to the AOAC techniques. Protein quality was determined by the Protein Efficiency Ratio test (PER) and in vivo digestibility. Amarantole-lacto serum show the highest percent cent in protein content (22.66 percent). The minerals more abundant in all the mixtures were Ca, K, Mg and Na. In general, all the mixtures presented highest values of PER (2.61 a 3.26) than the reference (casein PER=2.5) diet. Mixtures added of lactoserum and milk-lactoserum (88.19 y 86.0 percent) presented a similar digestibility to the casein diet (91.28 percent). In conclusion, Amarantole-lactoserum mixture showed the best characteristics concerning protein content, digestibility and PER value.

El objetivo de este trabajo fue aumentar el contenido proteico de una bebida a base de amaranto (Amaranto-le) mediante la adición de diferentes fuentes proteicas (garbanzo, alverja, lactosuero, leche en polvo, leche de soya). Se prepararon mezclas de Amarantole-fuente proteica en cuatro proporciones distintas (80:20, 75:25, 70:30 y 60:40). Las mejores mezclas fueron seleccionadas en base a su aumento en el contenido proteico y sus características organolépticas detectadas mediante pruebas de grado de satisfacción, de preferencia y de ordenamiento. La composición química y mineral de las mezclas seleccionadas fue determinada mediante técnicas del AOAC. La calidad proteica se determinó a través de la prueba de Relación de Eficiencia Proteica (REP) y la digestibilidad in vivo. Amarantole-lactosuero alcanzó el porcentaje de proteína más elevado (22.66 por ciento). Los minerales más abundantes en todas las mezclas fueron: Ca, K, Mg y Na. En general, todas las mezclas, presentaron valores de REP (2.61 a 3.26) superiores a la dieta de referencia (caseína REP=2.5). Las mezclas adicionadas de lactosuero y leche en polvo-lactosuero (88.19 y 86.0 por ciento) presentaron una digestibilidad similar a la dieta de caseína (91.28 por ciento). En conclusión, la muestra Amarantole-lactosuero fue la mezcla que presentó las mejores características en cuanto a contenido de proteína, digestibilidad y valor de REP.

Late acute humoral rejection in low-risk renal transplant recipients induced with an interleukin-2 receptor antagonist and maintained with standard therapy: preliminary communication.

Low-risk renal transplant recipients treated with standard immunosuppressive therapy including interleukin-2 receptor (IL-2R) antagonist show a low incidence of early rejection episodes but few reports have examined the incidence and severity of late rejection processes. This study evaluated retrospectively cellular and antibody-mediated rejection (AMR) among 42 recipients selected because they showed low panel-reactive-antibodies, short cold ischemia time, no delayed graft function, and therapy including basiliximab (Simulect) induction. The mean observation time was 6.6 years. Sixty-seven percent of donors were deceased. Ten-year patient and death-censored graft survivals were 81% and 78%, respectively. Seven patients lost their kidneys due to nonimmunologic events. The seven recipients who experienced cellular rejection episodes during the first posttransplant year had them reversed with steroids. Five patients displayed late acute AMR causing functional deterioration in four cases including 1 graft loss. De novo sensitization occurred in 48% of recipients including patients without clinical rejection. In conclusion, long-term follow-up of kidney transplant recipients selected by a low immunologic risk showed a persistent risk of de novo sensitization evolving to acute AMR in 11% of cases. Although immunologic events were related to late immunosuppressive reduction, most graft losses were due to nonimmunologic factors.

Alloantigen-specific response is preserved and autoimmunity is maintained in an HIV-positive patient with immunoglobulin A nephropathy undergoing renal transplantation: a warning about long-term reduction in immunosuppression--a case report.

We report the case of a 43-year-old patient with HIV infection treated with antiretroviral therapy, which was complicated by immunoglobulin A (IgA) nephropathy and renal failure, who subsequently was transplanted using a deceased donor kidney transplant. During the late posttransplant period we detected specific anti-donor HLA antibodies showing a preserved alloantigen response. A renal biopsy showed no acute cellular or humoral rejection, an absence of pericapillary C4d deposits or SV40 infected cells, but demonstrated IgA mesangial deposits and mild interstitial fibrosis probably related to calcineurin inhibitor toxicity. This case shows that allo- and autoimmune responses are preserved despite immunosuppressive treatment and original HIV disease. It warns of the importance of maintaining optimal monitoring and immunosuppressive strategies among HIV-positive recipients who become solid organ transplant recipients.

Determinación del valor de corte de la relación aldosterona/actividad de renina plasmática para la detección de hiperaldosteronismo primario en hipertensión arterial esencial: estudio multicéntrico / Determination of the Aldosterone/Plasma Renin Activity Ratio for the Screening of Primary Hyperaldosteronism in Essential Hypertension: a Multicentric Study

El hiperaldosteronismo primario (HAP) es una afección caracterizada por la producción inapropiadamente elevada y una relativa autonomía del sistema renina-angiotensina. Estimaciones previas, basadas sólo en la evaluación de hipertensos con hipokalemia, consideraban al HAP como una causa poco frecuente de hipertensión (1%). Sin embargo, estudios actuales fundamentados en el cálculo de la relación aldosterona/ actividad de renina plasmática (RAA) arrojan una incidencia mayor (5-10%), siendo la hipertensión arterial (HTA) normokalémica la presentación más frecuente. Dada la amplitud de los valores de corte de la RAA, el Departamento de Suprarrenal de SAEM diseñó un estudio multicéntrico prospectivo en una población de Argentina con el objetivo de establecer nuestro propio valor y determinar así la prevalencia de HAP. Fueron estudiados 353 individuos de ambos sexos, 104 controles normotensos, sin antecedentes familiares de HTA y 249 pacientes hipertensos. Se indicó dieta normosódica y la suspensión de antihipertensivos que interfieran con el eje mineralocorticoideo. Las determinaciones de la actividad de renina plasmática (ARP), DIA-SorinRIA, y de aldosterona, RIA-DPC, fueron realizadas en un único laboratorio. Se realizó ionograma y se evaluaron parámetros clínicos y bioquímicos de síndrome metabólico. La RAA calculada según el percentilo 95 en los controles, fue establecida en la cifra de 36 como valor de corte para sospechar HAP en los hipertensos, requiriéndose una concentración de aldosterona >15 ng/ml. Con una RAA≥36, se realizaron pruebas confirmatorias de sobrecarga salina o de fludrocortisona. La RAA fue ≥36 en 31/249 pacientes, confirmándose HAP en 8 (7 adenomas y 1 hiperplasia), con una prevalencia del 3.2%. Los restantes no completaron estudios confirmatorios. La presencia de síndrome metabólico fue similar en los hipertensos con y sin HAP. En conclusión, este primer estudio multicéntrico argentino determinó nuestro valor de corte de la RAA en 36. Su aplicación permitió establecer una prevalencia de HAP del 3,2% que, aunque podría estar subestimada, resulta significativamente mayor que la previa histórica y concuerda con la incidencia referida en la bibliografía.

Primary hyperaldosteronism (PHA) or Conn's disease was classically suspected in the presence of hypertension (H) and hypokalemia. It was previously considered as a rare cause of H, being reported in only 1% of hypertensive patients. It can be caused by an adrenal adenoma (the former usual presentation) or by adrenal hyperplasia. But since the use of the aldosterone/plasma renin activity ratio (AAR) as the screening method in the last years, it is currently considered as almost the most frequent cause of secondary H., accounting for 5-10% of essential H. Plasma rennin activity (PRA) determination is a laborious procedure with low reproducibility and it directly affects the AAR; thus each laboratory must assess its own cut-off value. Therefore, in the Adrenal Department of the Argentine Society of Endocrinology and Metabolism (SAEM), we performed this multicentric prospective study of a population of Argentina with the aim of assessing our own AAR cut-off level in normotensive controls in order to apply it for PHA screening in essential hypertensive patients. We studied 353 adult subjects: 104 controls, aged 45,18 ± 13,78 years-old ( X±SD), with no history of arterial hypertension in their first-degree relatives and with two separate day-registry of blood pressure≤ 139/85 mmHg and 249 hypertensive patients, aged 51± 13,6 years-old ( X ± SD), with arterial blood pressure≥ 140/90 mmHg in the sitting position. Subjects with cardiac, renal, hepatic and neurological diseases were excluded as well as those with Cushing´s syndrome, hyperthyroidism, untreated hypothyroidism, diabetes mellitus and patients under glucocorticoids, oral contraceptive pills or estrogen therapy. A normal sodium diet was indicated and potassium was supplemented when needed. Blood was withdrawn between 8 and 10:00 a.m. with the subjects in the upright position. Aldosterone (A) was determined by DPC radioimmunoassay (RIA) and PRA, by DIA-Sorin RIA. The A normal levels are 4-30 ng/dl for ambulatory individuals on a normal sodium diet and the PRA normal values are < 3,3 ng/ml/h. In order to avoid false positive results in the hypertensive group, AAR was calculated when A was above 15 ng/dl. We measured the waist circumference and we determined the body mass index. Blood sodium, potassium, calcium, urea, creatinine, cholesterol, HDL-C, LDL-C, triglyceride and liver function tests were performed. Statistical Analysis and Results Since the AAR variable showed a non-normal distribution, the cut-off value was considered as the 95th percentile in the control group, which was calculated as 36. This is also in accordance to the function of the empirical distribution of Collings and Hamilton. In our 249 hypertensive patients, 31 had an AAR ≥ 36. PHA was confirmed in 8: seven has an adrenal adenoma and one had hyperplasia. The prevalence of PHA in our population was 3,2 %, with a 95th confidence interval ranging from 1,4 to 6,2 %. In the remaining 23 patients, confirmatory tests could not be completed. There was no correlation between the severity of the hypertension and the AAR value, with no statistical significant differences between those with or without PHA. Likewise, we found no correlation between PRA and advancing age. In hypertensive patients, metabolic syndrome was more prevalent than in controls, but it was present to the same extent in those with or without PHA. Conclusions To our knowledge, this is the first multicentric study performed in Argentina to determine the aldosterone/ plasma renin activity ratio in our normotensive control population. Our AAR value of 36 agrees with the levels reported in the international literature: thus an AAR ≥ 36 along with an aldosterone ≥ 15 ng/ml in hypertensive patients lead us to suspect PHA and to perform confirmatory tests. Applying these criteria, we found a prevalence of 3,2% of PHA in essential HTA. It is possible that this value may be underestimated due to the fact that confirmatory tests could not be completed in all the hypertensive subjects with an AAR≥ 36. In spite of this, our prevalence is significantly greater than the historical one and it lies in the range reported in the literature.

Evaluation of late immunologic parameters among renal transplant recipients induced with Campath-1H.

Organ transplantation success depends principally on avoiding rejection, a purpose almost accomplished with immunosuppressant therapy. Nevertheless, drug side effects have promoted the search for other mechanisms to restrain alloresponses. T-regulatory cells (Treg) might exert that function. Campath 1H (C1H) induces Treg proliferation in the period subsequent to T-cell depletion following C1H administration. In the present study, the status of Treg and de novo HLA antibody production was determined posttransplantation when T-cell repopulation had been completed. In 14 patients, the following parameters were analyzed: renal function, rejection, Treg, panel-reactive antibody (PRA), and HLA antibodies. Patient and graft survivals were 100%. At the moment of Treg determination (20 months following transplant) the mean tacrolimus level was 8.4 ng/mL. One patient experienced an antibody-mediated rejection at 15 months after transplantation while having 3.2% Treg, with excellent treatment responses. Mean leukocyte and lymphocyte counts were 5752 and 1183 cells/mm(3); the mean peripheral blood percentage of Treg of 7.1% +/- 5.9% was not different from that observed in subjects without induction (mean 5.5% +/- 2.5%). Three patients (21%) showed Treg greater than 8.0%. In seven patients, we compared Treg at 4 and 20 months posttransplant, observing a decline from a mean of 19.9% to 5.9% (P = .05). In seven recipients, posttransplant PRA was determined; five of them became "de novo" sensitized, three with a mean class I PRA of 16% and two with a mean class II PRA of 37%. In conclusion, patient and graft survivals were excellent, mean Treg percentage was not elevated with results lower than in the early posttransplant period. Rejection incidence was negligible. Late "de novo" sensitization occurred in 70% showing that B cell-mediated alloresponses were only partially controlled among recipients induced with C1H even when associated with sustained anticalcineurin treatment.

Experimental and theoretical determination of the low-loss electron energy loss spectroscopy of LiMn2O4.

The dielectric properties of cubic spinel-type LiMn(2)O(4), used as cathode material in lithium ion secondary batteries, are studied by analyzing the low-loss region of the electron energy loss spectroscopy (EELS) spectrum in a transmission electron microscope. A comparison of experimental EELS spectra and ab initio density-functional theory calculations (WIEN2k code) within the generalized gradient approximation (GGA) is presented. The origins of interband transitions are identified in the electronic band structure, by calculating the partial imaginary part of the dielectric function and the partial density of states of Li, Mn and O. Good agreement with experimental spectra is observed which allowed interpreting main features of the EELS spectrum.