Improving bitter pit prediction by the use of X-ray fluorescence (XRF): A new approach by multivariate classification.

Bitter pit (BP) is one of the most relevant post-harvest disorders for apple industry worldwide, which is often related to calcium (Ca) deficiency at the calyx end of the fruit. Its occurrence takes place along with an imbalance with other minerals, such as potassium (K). Although the K/Ca ratio is considered a valuable indicator of BP, a high variability in the levels of these elements occurs within the fruit, between fruits of the same plant, and between plants and orchards. Prediction systems based on the content of elements in fruit have a high variability because they are determined in samples composed of various fruits. With X-ray fluorescence (XRF) spectrometry, it is possible to characterize non-destructively the signal intensity for several mineral elements at a given position in individual fruit and thus, the complete signal of the mineral composition can be used to perform a predictive model to determine the incidence of bitter pit. Therefore, it was hypothesized that using a multivariate modeling approach, other elements beyond the K and Ca could be found that could improve the current clutter prediction capability. Two studies were carried out: on the first one an experiment was conducted to determine the K/Ca and the whole spectrum using XRF of a balanced sample of affected and non-affected 'Granny Smith' apples. On the second study apples of three cultivars ('Granny Smith', 'Brookfield' and 'Fuji'), were harvested from two commercial orchards to evaluate the use of XRF to predict BP. With data from the first study a multivariate classification system was trained (balanced database of healthy and BP fruit, consisting in 176 from each group) and then the model was applied on the second study to fruit from two orchards with a history of BP. Results show that when dimensionality reduction was performed on the XRF spectra (1.5 - 8 KeV) of 'Granny Smith' apples, comparing fruit with and without BP, along with K and Ca, four other elements (i.e., Cl, Si, P, and S) were found to be deterministic. However, the PCA revealed that the classification between samples (BP vs. non-BP fruit) was not possible by univariate analysis (individual elements or the K/Ca ratio).Therefore, a multivariate classification approach was applied, and the classification measures (sensitivity, specificity, and balanced precision) of the PLS-DA models for all cultivars evaluated ('Granny Smith', 'Fuji' and 'Brookfield') on the full training samples and with both validation procedures (Venetian and Monte Carlo), ranged from 0.76 to 0.92. The results of this work indicate that using this technology at the individual fruit level is essential to understand the factors that determine this disorder and can improve BP prediction of intact fruit.

Effects of Three Irrigation Strategies on Gas Exchange Relationships, Plant Water Status, Yield Components and Water Productivity on Grafted Carménère Grapevines.

In the Chilean viticultural industry, Carménère is considered an emblematic cultivar that is cultivated mainly in arid and semi-arid zones. For this reason, it is necessary to use precise irrigation scheduling for improving water use efficiency (WUE), water productivity (WP), yield and wine quality. This study evaluated the effects of three deficit irrigation strategies on gas exchange variables, WUE, WP and yield components in a drip-irrigated Carménère vineyard growing under semi-arid climatic conditions during two consecutive seasons (2011/12 and 2012/13). The irrigation strategies were applied in completely randomized design from fruit set (S) to harvest (H). The first irrigation strategy (T1) involved continuous irrigation at 100% of actual evapotranspiration (ETa) from S to the veraison (V) period and at 80% of ETa from V to H. The second irrigation strategy (T2) involved irrigation at 50% of ETa from S to H and the third one (T3) involved no-irrigation from S to V and at 30% of ETa from V to H. The results indicated that there was a significant non-linear correlation between net CO2 assimilation (AN) and stomatal conductance (gs), which resulted in three zones of water stress (zone I = gs > 0.30 mol H2O m-2s-1; zone II = between 0.06 and 0.30 mol H2O m-2s-1; and zone III = gs < 0.06 mol H2O m-2s-1). The use of less water by T2 and T3 had a significant effect on yield components, with a reduction in the weight and diameter of grapes. A significant increase in WP (7.3 kg m-3) occurred in T3, which resulted in values of WUE that were significantly higher than those from T1 and T2. Also, a significant non-linear relationship between the integral water stress (SIΨ) and WP (R2 = 0.74) was established. The results show that grafted Carménère vines were tolerant to water stress although differences between cultivars/genotypes still need to be evaluated.

Mechanical thrombectomy using the Solitaire stent in a left main coronary artery: A novel approach to coronary thrombus retrieval.

The Solitaire stent is a self-expanding nitinol, fully retrievable stent that was originally designed for applications in cerebral circulation. Expanded indications for its use in mechanical embolectomy during acute ischemic stroke have proven safe and effective. Herein, we describe a novel use of this stent to perform a mechanical thrombectomy of a large left main coronary artery thrombus. © 2016 Wiley Periodicals, Inc.

Polineuropatía motora subaguda secundaria a intoxicación por plomo / Subacute motor polyneuropathy secondary to lead poisoning

Las manifestaciones clínicas de la intoxicación por plomo son variadas e inespecíficas y continúan siendo un reto diagnóstico, en especial cuando son producto de presentaciones tan infrecuentes como las secundarias a fragmentos por proyectiles de arma de fuego intraarticulares. En suamplio espectro de manifestaciones se han descrito cambios que van desde el déficit de atenciónhasta estados más avanzados como las polineuropatías. El diagnóstico se basa principalmente enla medición del metal en distintos elementos del paciente y el tratamiento en medidas generales desoporte y terapia de quelación. Describimos el caso de un hombre con el antecedente de una herida por arma de fuego en caderaderecha, con un cuadro clínico progresivo de dolor abdominal, anemia acompañada de punteadobasófilo y manifestaciones neurológicas. Con un estudio por electromiografía que reporto unapolineuropatía axonal desmielinizante motora y sensitiva. Sus niveles séricos de plomo fueron 113µg/dL (Rango normal hasta 10 µg/dL) y después de un esquema de tratamiento con edetato calciodisódico (EDTA) más D penicilamina los síntomas neurológicos mejoraron asociado a un controlsérico de plomo de 49.1 µg/dL. Conclusión: la intoxicación por plomo es causa de polineuropatía motora subaguda especialmente en pacientes con exposición prolongada y niveles séricos altos de plomo. (Acta Med Colomb2014; 39: 185-190).

The clinical manifestations of lead poisoning are varied and nonspecific and remain a diagnostic challenge, especially when they are product of infrequent presentations such as the secondary to intraarticular gun fire fragments. In its broad spectrum of manifestations, changes ranging from attention deficit disorder to more advanced states like polyneuropathies have been described. The diagnosis is based mainly on the measurement of metal in various elements of the patient, and treatment in general supportive measures and chelation therapy. The case of a man with a history of gunshot wound in right hip with a progressive clinical picture of abdominal pain, anemia accompanied by basophilic stippling and neurological manifestations is described. The electromyography reported a motor and sensory axonal demyelinating polyneuropathy. Serum levels of lead were 113 µg/dL (normal range up 10 µg/dL) and after a treatment regimen with calcium disodium edetate (EDTA ) plus D penicillamine, the neurological symptoms improved, associated with a serum lead control of 49.1 µg/dL. Conclusion: lead poisoning causes subacute motor polyneuropathy especially in patients with prolonged exposure and high serum lead levels. (Acta Med Colomb 2014; 39: 185-190).

Desórdenes del desarrollo sexual y cirugía correctiva / Disorders of sexual development and corrective surgery

El desarrollo de las gónadas está determinado por los cromosomas sexuales y autosomas, estas producen hormonas que dirigen la formación de los genitales internos y externos. Los desórdenes en la diferenciación sexual se presentan cuando hay anormalidades en cromosomas, en el desarrollo gonadal o en la actividad o producción de hormonas. La presente revisión tiene como objetivo la recopilación de información que comprende los desordenes del desarrollo sexual que podrían presentar los niños al nacimiento y la posterior cirugía de corrección. Se desarrolla brevemente la anatomía normal tanto del sistema genitourinario masculino como el femenino, presentando las similitudes y diferencias. La sexualidad de las personas está determinada por el sexo cromosómico, sexo gonadal, sexo genital y sexo social, con base en estos determinantes se establece el procedimiento quirúrgico más adecuado. La investigación se enfoca en la cirugía de feminización, en la cual, se efectúa una reducción de clítoris, separación de vagina y uretra; además de una vaginoplastía. Actualmente, los resultados de la cirugía correctiva son los más óptimos, sin embargo, gran cantidad de estudios indica que no todas las personas que se someten a ellas están satisfechas con los resultados obtenidos refiriéndose a función sexual.

Gonadal development is determined by sexual chromosomes and autosomes, which produce hormones that direct the formation of internal and external genitals. Disorders in sexual differentiation appear when abnormalities in chromosomes, gonadal development or activity or production of hormones are present. This investigation is a review of research about disorders in sexual development present in children at birth and the following correction surgery. Also, it includes information concerning the normal anatomy of male and female genitourinary system, showing similarities and differences between them. People’s sexuality is determined by the chromosome sex, gonadal sex, genital sex and social sex. Based on these factors, physicians can determine the best surgical procedure for the patient. This investigation is focused on feminization surgery, in which a reduction of clitoris is done. After this, a separation of the vagina and urethra is also performed to then finalize with a vaginoplasty. Nowadays, the results of the correction surgery are the best that can be done, however, several studies indicate that not all patients are fulfilled with the results.

Cardiomiopatía inducida por taquicardia una mujer con flutter atrial / Cardiomyopathy induced by tachycardia in a woman with atrial flutter

Resumen La cardiomiopatía inducida por taquicardia (cit) es una causa infrecuente y potencialmente reversible de falla cardiaca, sus manifestaciones clínicas son inespecíficas y el tratamiento debe estar dirigido a las estrategias que pretenden controlar el ritmo cardiaco como la cardioversión, la ablación, el tratamiento con antiarrítmicos para lograr disminuir los síntomas y mejorar la función ventricular izquierda. Presentamos el caso de una mujer de 24 años con cardiopatía dilatada severa secundaria a flutter auricular en la cual se demostró recuperación completa de la fracción de expulsión luego de realizar cardioversión eléctrica y posteriormente aislamiento del istmo cavotricuspídeo. Conclusión: el flutter atrial es una causa común de taquicardia que puede llevar a colapso hemodinámico, formación de trombos atriales y a manifestaciones infrecuentes como la cardiomiopatía, por lo cual se debe procurar en un reconocimiento temprano e instaurar estrategias de manejo a corto y largo plazo que garanticen una frecuencia cardiaca normal. (Acta Med Colomb 2013; 38: 173-176).

Abstract Cardiomyopathy induced by tachycardia (TIC) is a rare and potentially reversible cause of heart failure. Its clinical manifestations are nonspecific and treatment should be directed to strategies that seek to control heart rhythm such as cardioversion, ablation, treatment with antiarrhythmic to achieve reduce symptoms and improve left ventricular function. We report the case of a 24 year old woman with severe dilated cardiomyopathy secondary to atrial flutter. After electrical cardioversion and subsequent isolation of the cavotricuspid isthmus, she had a complete recovery of the ejection fraction. Conclusion: atrial flutter is a common cause of tachycardia that can lead to hemodynamic collapse, atrial thrombus formation and uncommon manifestations such as cardiomyopathy; for this reason, efforts should be made to do early recognition and establish management strategies for the short and long term to guarantee a normal heart rate. (Acta Med Colomb 2013; 38: 173-176).

Múltiples abscesos cerebrales por Listeria monocitogenes en un paciente con infección por el virus de inmunodeficiencia humana, primer caso descrito en Colombia / Multiple brain abscesses caused by Listeria monocytogenes in a patient infected with human immunodeficiency virus, the first case reported in Colombia

Las manifestaciones en el sistema nervioso central por Listeria monocytogenes son variadas, e incluyen desde la meningitis hasta las presentaciones más infrecuentes como los abscesos cerebrales. Éstos son clínicamente indistinguibles de otros tipos de abscesos y sugieren una alteración de la inmunidad celular. Se describe el caso de una mujer seropositiva para el virus de la inmunodeficiencia humana (VIH) que consultó al servicio de urgencias con un síndrome convulsivo tónico-clónico generalizado de un mes de evolución y deterioro progresivo de su estado de conciencia. En el estudio del líquido cefalorraquídeo se encontró pleocitosis linfocitaria, con elevación de las proteínas e hipoglucorraquia. En el estudio del sistema nervioso central por resonancia magnética se observaron múltiples lesiones hipodensas que se realzaban con el medio contraste. Se aisló L. monocytogenes en el cultivo del líquido cefalorraquídeo. Después de un esquema de tratamiento antibiótico específico asociado a esteroides, los síntomas neurológicos mejoraron y, concomitantemente, se observó una disminución progresiva hasta la desaparición de las lesiones en el seguimiento imaginológico del sistema nervioso central. L. monocytogenes es causa de abscesos cerebrales en pacientes inmunosuprimidos, en especial, con VIH sin terapia antirretroviral o sin profilaxis con trimetoprim-sulfametoxazol.

The manifestations of Listeria monocytogenes central nervous system infection are wide, ranging from meningitis to cerebral abscesses. Those are clinically indistinguishable from other forms of cerebral abscesses. We are describing a HIV positive woman who presented with generalized tonicclonic seizures, progressive alter mental status, evidence of lymphocytic pleocytosis and multiple hypodense lesions that enhanced with contrastae on imaging studies (CT and MRI) Listeria monocytogenes was isolated of cefaloraquid liquid cultures. After a specific antibiotic treatment regimen associated with steroids, improved neurological symptoms and concomitant documented a progressive decrease until disappearance of the lesions in the CNS imaging follow. Listeria monocytogenes is a cause of brain abscesses in immunosuppressed patients especially HIV patients without antiretroviral therapy and without prophylaxis with trimethoprim / sulfamethoxazole.

[Guides for rational use of B-lactam antibiotics:resistance mechanism and clinical interpretation]. / Guías para el uso racional de antibióticos beta-lactámicos: mecanismos de resistencia y su interpretación clínica.

beta-lactams are the antibiotic compounds most widely used against hospital and community acquired infections. However, resistance has emerged in both Gram-positive and Gram-negative bacteria, limiting their therapeutic efficacy. The choice of appropriate treatment depends on analysis of susceptibility data that indicates a specific mechanism of resistance. Correct interpretation of susceptibility tests permits a rational approach to the resistance problem and selection of alternatives for treatment. The laboratory must first be able to identify accurately microorganisms to the species level and then test a minimum of relevant antimicrobials. beta-lactam resistance in Enterobacteriaceae is mainly due to the production of plasmid or chromosomal encoded beta-lactamases. In Gram-negative non-fermenting bacteria, impermeability and efflux are relatively more important to the treatment selected. In Gram-positive bacteria, resistance mechanisms can involve changes in penicillin-binding proteins (PBPs), production of new PBPs or synthesis of beta-lactamases. The range of therapeutic options must be based on the current status of local resistance mechanisms.

Guías para el uso racional de antibióticos Beta-lactámicos: mecanismos de resistencia y su interpretación clínica / Guides for rational use of Beta-Lactam antibiotics: resistance mechanisms and clinical interpretation

Los antibióticos á-lact micos son los compuestos más ampliamente usados para tratar infecciones adquiridas en el hospital o en la comunidad. Sin embargo, la resistencia a estos antibióticos en bacterias Gram negativas y Gram positivas se ha incrementado, lo cual limita su eficacia terapéutica. Se debe estar alerta a este fenómeno y seleccionar la terapia de acuerdo con el mecanismo de resistencia probable del germen aislado. La lectura interpretativa de los patrones de susceptibilidad permite un enfoque más racional del problema de resistencia y se convierte en una guía fundamental para el manejo de situaciones específicas. Dada la complejidad de los mecanismos de resistencia, es indispensable que el laboratorio identifique los microorganismos según especie y determine la susceptibilidad de un número razonable de antimicrobianos. La resistencia a á-lact micos en Enterobacteriaceae se debe principalmente a la producción de á-lactamasas codificadas cromosómicamente o en plásmidos. Los mecanismos de impermeabilidad y la producción de bombas de exclusión molecular son los más comunes en microorganismos 'no fermentadores', por lo cual la terapia debe responder a estos fenómenos. En bacterias Gram positivas existen varios mecanismos involucrados: producción de proteínas de unión a penicilina (PBP) alteradas, síntesis de nuevas PBP o producción de á-lactamasas. Se discuten aquí las opciones terapéuticas basadas en el conocimiento de los mecanismos de resistencia.

Resistencia bacteriana: un problema actual / Bacterial resistance: a present problem

La resistencia bacteriana a la acción de los antibióticos utilizados en clínica es un problema prioritario de salud pública. El conocimiento de los mecanismos moleculares de resistencia, así como de las técnicas, tanto microbiológicas como moleculares para detectarla permiten un uso racional y adecuado de los antibióticos. En esta revisión se presentan las más recientes técnicas de laboratorio que permiten el estudio de la resistencia antimicrobiana desde la difusión en disco, hasta la reacción en cadena de la polimerasa. Se enfatiza la importancia de la interpretación de estas pruebas con el fin de beneficiar al paciente y prevenir en lo posible la diseminación de cepas resistentes.