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BACKGROUND/AIMS: Including women of childbearing age in a clinical trial makes it necessary to consider two factors from a bioethical perspective: first, the lack of knowledge about the potential teratogenic effects of an investigational product, and also, the principle of justice not to exclude any population from the benefits of research. The most common way to address this issue is by requiring volunteers to use contraceptives before, during, and a few weeks after the clinical trial. This work presents all the strategies used to promote contraception use and prevent pregnancy during the Alzheimer's Prevention Initiative Autosomal-Dominant Alzheimer's Disease (API ADAD) Colombia clinical trial. Two characteristics of this trial make it of special interest for closely monitoring contraception use. One is that the trial lasted more than 7 years, and the other is that participants could be carriers of the E280A PSEN1 mutation, leading to a mild cognitive impairment as early as their late 30s. METHODS: An individual medical evaluation to select the contraception method that best fits the volunteer was carried out during the screening visit, remitting to the gynecologist when necessary. All non-surgical contraception methods were supplied by the sponsor. Staff were trained on contraception counseling, correctly dispensing contraceptive drugs to volunteers, and identifying, reporting, and following up on pregnancies. Two comprehensive educational campaigns on contraception use were performed, and the intervention included all volunteers. In addition, volunteers were asked on an annual survey to evaluate the dispensing procedure. Finally, the effectiveness of these strategies was retrospectively evaluated, comparing by extrapolation the number of pregnancies presented throughout the trial with the General Fertility Rate in Colombia. RESULTS: A total of 159 female volunteers were recruited. All strategies were implemented as planned, even during the COVID-19 contingency. Ten pregnancies occurred during the evaluation period (2015-2021). Two were planned; the rest were associated with a potential therapeutic failure or incorrect use of contraceptive methods for a contraceptive failure of 0.49% per year. Sixty percent of pregnancies led to an abortion, either miscarriage or therapeutic abortion. However, there was not enough data to associate the pregnancy outcome with the administration of the investigational product. Finally, we observed a lower fertility rate in women participating in the trial compared to the Colombian population. CONCLUSION: The lower rates of contraceptive failure and the decrease in the incidence of pregnancies in women participating in the trial compared to the Colombian population across the 7 years of evaluation suggest that the strategies used in API ADAD Colombia were adequate and effective in addressing contraception use.

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This work reports the dielectric behavior of the biopolymer ethyl cellulose (EC) observed from transient currents experiments under the action of a direct current (DC) electric field (~107 V/m) under vacuum conditions. The viscoelastic response of the EC was evaluated using dynamic mechanical analysis (DMA), observing a mechanical relaxation related to glass transition of around ~402 K. Furthermore, we propose a mathematical framework that describes the transient current in EC using a fractional differential equation, whose solution involves the Mittag-Leffler function. The fractional order, between 0 and 1, is related to the energy dissipation rate and the molecular mobility of the polymer. Subsequently, the conduction mechanisms are considered, on the one hand, the phenomena that occur through the polymer-electrode interface and, on the other hand, those which manifest themselves in the bulk material. Finally, alternating current (AC) conductivity measurements above the glass transition temperature (~402 K) and in a frequency domain from 20 Hz to 2 MHz were carried out, observing electrical conduction described by the segmental movements of the polymeric chains. Its electrical properties also position EC as a potential candidate for electrical, electronics, and mechatronics applications.

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Today, shape memory alloys (SMAs) have important applications in several fields of science and engineering. This work reports the thermomechanical behavior of NiTi SMA coil springs. The thermomechanical characterization is approached starting from mechanical loading-unloading tests under different electric current intensities, from 0 to 2.5 A. In addition, the material is studied using dynamic mechanical analysis (DMA), which is used to evaluate the complex elastic modulus E* = E' - iE″, obtaining a viscoelastic response under isochronal conditions. This work further evaluates the damping capacity of NiTi SMA using tan δ, showing a maximum around 70 °C. These results are interpreted under the framework of fractional calculus, using the Fractional Zener Model (FZM). The fractional orders, between 0 and 1, reflect the atomic mobility of the NiTi SMA in the martensite (low-temperature) and austenite (high-temperature) phases. The present work compares the results obtained from using the FZM with a proposed phenomenological model, which requires few parameters for the description of the temperature-dependent storage modulus E'.

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Objective: We aimed to describe the microbiological characteristics of infections in patients from an oncological center during 2.014-2.016. Methods: In this cross-sectional descriptive study, a total of 7.837 cultures corresponding to 1.216 patients were included. Microbiological and sociodemographic data were taken from cancer diagnosed patients admitted to Oncólogos de Occidente S.A. in Pereira, Armenia, Manizales and Cartago from January 2.014 to December 2.016. The bacterial resistance profiles were defined according to the CLSI guideline. Culture foci were blood, urine, tissue biopsies, skin and soft tissues, mucous membranes and feces. Results: The culture-positive rate was 27,94%. Amongst 2.190 isolates, Escherichia coli (22,42%) was the most frequent, followed by Klebsiella pneumonia (21,27%), Pseudomona aeruginosa (13,83%) and Staphylococcus aureus (5,11%). The most common mechanisms of antimicrobial resistance in Gram-negatives were Extended-Spectrum β-Lactamase (45,45%) and AmpC-type β-lactamases (37,71%). Discussion: Up to nearly one-third of our participants' cultures were positive and a vast majority were gram-negatives, provided with ESBLs or AmpCs which in oncological patients it is a catastrophic outcome. We recommend to establish antibiotic dispensing policies thus achieving a microbiological risk control and improve the epidemiological surveillance. Empirical use of beta-lactams with extended spectrum or cephalosporins of 1 to 3 generation is not recommended due to the high resistance found.

Objetivo: Describir las características microbiológicas de las infecciones en pacientes de un centro oncológico durante 2.014-2.016 Métodos: Estudio descriptivo, transversal. Incluyó 7.837 cultivos de 1.216 pacientes. Se recolectaron variables microbiológicas y sociodemográficas de pacientes diagnosticados con cáncer en las sedes de Pereira, Armenia, Manizales y Cartago de Oncólogos de Occidente S.A. durante 2.014 hasta 2.016. Los perfiles de resistencia bacteriana se definieron de acuerdo con la guía CLSI. Los focos de cultivo fueron sangre, orina, biopsias de tejidos, piel y tejidos blandos, membranas mucosas y heces. Resultados: La tasa de cultivo positivo fue del 27,94%. De 2.190 aislamientos, E. coli (22,42%) fue el más frecuente, seguido de K. pneumoniae (21,27%), P. aeruginosa (13,83%) y S. aureus (5,11%). Los principales mecanismos de resistencia identificados en Gram negativos fueron β-lactamasas de espectro extendido (45,45%) y β-lactamasa de tipo AmpC (37,71%). Discusión: Cerca de un tercio de los cultivos de los participantes fueron positivos y una vasta mayoría fueron gram negativos, provistos con ESBL o AmpC, lo que en pacientes oncológicos es un desenlace catastrófico. Recomendamos establecer políticas de dispensación de antibióticos, logrando así un control de riesgo microbiológico y mejorar la vigilancia epidemiológica. No se recomienda el uso empírico de betalactámicos con espectro extendido o cefalosporinas de 1 a 3 generación debido a la alta tasa de resistencia encontrada.

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The visual experience of objects lies in the ability to perceive and integrate their constitutive features. Conjunctive binding (CB) is the cognitive function that integrates the features of objects as wholes. This review covers the main findings (over the last 10 years) concerning the role of CB in visual working memory (VWM) and cognitive theory, its neural correlates, as well as perspectives for future work. First, we discuss the theoretical cognitive models of CB and how these relate to other cognitive functions. We then integrate neuroimaging evidence with cognitive theory to identify the neural functional network of CB for encoding and maintenance. Also, we describe the field's transition from experimental to clinical research, which paves the way for work in the area of VWM binding and aging. Finally, we expose the challenges faced by this field of research and analyze its role in the study of dementia and the construction of neuro-cognitive models of conjunctive binding.

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A new process for obtaining dibenzo[c,f][1,2,5]thiadiazepines (DBTDs) and their effects on GABA(A) receptors of guinea pig myenteric neurons are described. Synthesis of DBTD derivatives began with two commercial aromatic compounds. An azide group was obtained after two sequential reactions, and the central ring was closed via a nitrene to obtain the tricyclic sulfonamides (DBTDs). Whole-cell recordings showed that DBTDs application did not affect the holding current but inhibited the currents induced by GABA (I(GABA)), which are mediated by GABA(A) receptors. These DBTDs effects reached their maximum 3 min after application and were: (i) reversible, (ii) concentration-dependent (with a rank order of potency of 2c = 2d > 2b), (iii) mediated by a non-competitive antagonism, and (iv) only observed when applied extracellularly. Picrotoxin (which binds in the channel mouth) and DBTDs effects were not modified when both substances were simultaneous applied. Our results indicate that DBTD acted on the extracellular domain of GABA(A) channels but independent of the picrotoxin, benzodiazepine, and GABA binding sites. DBTDs used here could be the initial model for synthesizing new GABA(A) receptor inhibitors with a potential to be used as antidotes for positive modulators of these receptors or to induce experimental epilepsy.

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Whole-cell patch clamp recordings were used to characterise the physiological and pharmacological properties of P2X receptors of mouse and guinea pig myenteric neurons from the small intestine. ATP application induced a rapid inward current in 95% of recorded neurons of both species when were voltage clamped at -60 mV. Concentration-response curves for ATP (1-3000 microM) yielded EC(50) values of 114 and 115 microM for mouse and guinea pig myenteric neurons, respectively, with a Hill coefficient value of 1.02 and 0.79, respectively, which were not significantly different of unity. alpha,beta-methylene ATP (100 microM) was virtually inactive in both species. Pyridoxalphophate-6-azophenyl-2',4'-disulphonic acid (0.01-30 microM) inhibited the ATP-induced currents (I(ATP)) with a different potency; being the IC(50) 0.6 and 1.8 microM in mouse and guinea pig, respectively. In mouse myenteric neurons, I(ATP) were inhibited by suramin whereas in guinea pig neurons we observed two effects, potentiation and inhibition of these currents. On guinea pig, both effects of suramin had different recovering kinetics and concentration dependency, indicating that they are mediated by at least two different binding sites. Our observations indicate that myenteric P2X receptors in these two species have different pharmacological properties.

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Se describe un caso de Rhabdomiosarcoma en paciente femenina de 68 años de edad, de piel blanca, con imagen hipercaptante localizada a nivel T4

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Se realizó un estudio descriptivo y retrospectivo en 2 pacientes diagnosticados y tratados por sepsis posquirúrgica debido a fracturas de cadera en un período de dos años. Durante este período se realizaron 229 intervenciones quirúrgicas en dicha entidad, de ellas un 5,2 (por ciento) presentaron sepsis posquirúrgica. Se encontró la mayor incidencia de ella en pacientes del sexo femenino por encima de los 71 años de edad. Las fracturas extracapsulares predominaron significativamente. No se encontró diferencia notable entre la cirugía electiva y urgente. El tiempo quiúrgico se comportó en la mayoría de los casos entre 45 a 60 minutos. El germen que predominó fue el Stafilococus Aureus. La terapia antibiótica duró generalmente tres semanas. Se valoró el tiempo de hospitalización así como las complicaciones, las cuales se encontraron en un 25 (por ciento) de los casos

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