Rational design of biocatalysts based on covalent immobilization of acylase enzymes.

Acylases catalyze the hydrolysis of amide bonds. Penicillin G acylase (PGA) is used for the semi-synthesis of penicillins and cephalosporins. Although protein immobilization increases enzyme stability, the design of immobilized systems is difficult and usually it is empirically performed. We describe a novel application of our strategy for the Rational Design of Immobilized Derivatives (RDID) to produce optimized acylase-based immobilized biocatalysts for enzymatic bioconversion. We studied the covalent immobilization of the porcine kidney aminoacylase-1 onto aldehyde-based supports. Predictions of the RDID1.0 software and the experimental results led to the selection of glyoxyl-Sepharose CL 4B support and pH 10.0. One of the predicted clusters of reactive amino groups generates an enzyme-support configuration with highly accessible active sites, contributing with 82% of the biocatalyst's total activity. For Escherichia coli PGA, the predictions and experimental results show similar maximal amounts of immobilized protein and activity at pH 8.0 and 10.0 on glyoxyl-Sepharose CL 10B. However, thermal stability of the immobilized derivative is higher at pH 10.0 due to an elevated probability of multipoint covalent attachment. In this case, two clusters of amino groups are predicted to be relevant for PGA immobilization in catalytically competent configurations at pH 10.0, showing accessible active sites and contributing with 36% and 44% of the total activity, respectively. Our results support the usefulness of the RDID strategy to model different protein engineering approaches (site-directed mutagenesis or obtainment of fusion proteins) and select the most promising ones, saving time and laboratory work, since the in silico-designed modified proteins could have higher probabilities of success on bioconversion processes.

Targeting versus Tailoring Educational Videos for Encouraging Deceased Organ Donor Registration in Black-Owned Barbershops.

In the U.S., black men are at highest risk for requiring kidney transplants but are among those least likely to register for organ donation. Prior outreach used videos culturally targeted for Black communities, yet registration rates remain insufficient to meet demand. Therefore, we assessed whether generic versus videos culturally targeted or personally tailored based on prior organ donation beliefs differentially increase organ donor registration. In a randomized controlled trial, 1,353 participants in Black-owned barbershops viewed generic, targeted, or tailored videos about organ donation. Logistic regression models assessed the relative impact of videos on: 1) immediate organ donor registration, 2) taking brochures, and 3) change in organ donation willingness stage of change from baseline. Randomization yielded approximately equal groups related to demographics and baseline willingness and beliefs. Neither targeted nor tailored videos differentially affected registration compared with the generic video, but participants in targeted and tailored groups were more likely to take brochures. Targeted (OR = 1.74) and tailored (OR = 1.57) videos were associated with incremental increases in organ donation willingness stage of change compared to the generic video. Distributing culturally targeted and individually tailored videos increased organ donor willingness stage of change among Black men in Black-owned barbershops but was insufficient for encouraging registration.Abbreviations: CI - confidence interval; DMV - Department of Motor Vehicles; BOBs - Black-owned barbershops; ODBI - organ donation belief index; ODWS - organ donation willingness stage of change; OR - odds ratio.

Including Medical Footage and Emotional Content in Organ Donation Educational Videos for Latinx Viewers.

We assessed whether videos with medical footage of organ preservation and transplantation plus sad, unresolved, or uplifting stories differentially affect deceased organ donor registration among clients in Latinx-owned barbershops and beauty salons. In a 2 × 3 randomized controlled trial, participants (N = 1,696, mean age 33 years, 67% female) viewed one of six videos. The control portrayed a mother who received a kidney (uplifting), excluding medical footage. Experimental videos included medical footage and/or showed a mother waiting (unresolved) or sisters mourning their brother's death (sad). Regression models assessed relative impact of medical footage and storylines on: (1) registry enrollment, (2) donation willingness stage of change, and (3) emotions. Randomization yielded approximately equal groups relative to age, sex, education, religion, nativity, baseline organ donation willingness, beliefs, and emotions. Overall, 14.8% of participants registered. Neither medical footage, sad, nor unresolved stories differentially affected registration and changes in organ donation willingness. Sad and unresolved stories increased sadness and decreased positive affect by ~0.1 logits compared with the uplifting story. Educational videos about organ donation which excluded or included medical footage and varying emotional valence of stories induced emotions marginally but did not affect viewers' registration decisions differently. Heterogeneity of responses within video groups might explain the attenuated impact of including medical footage and varying emotional content. In future work, we will report qualitative reasons for participants' registration decisions by analyzing the free text responses from the randomized trial and data from semistructured interviews that were conducted with a subset of participants.

A comparison between two robust techniques for segmentation of blood vessels.

Image segmentation plays an important role in image analysis. According to several authors, segmentation terminates when the observer's goal is satisfied. For this reason, a unique method that can be applied to all possible cases does not yet exist. In this paper, we have carried out a comparison between two current segmentation techniques, namely the mean shift method, for which we propose a new algorithm, and the so-called spectral method. In this investigation the important information to be extracted from an image is the number of blood vessels (BV) present in the image. The results obtained by both strategies were compared with the results provided by manual segmentation. We have found that using the mean shift segmentation an error less than 20% for false positives (FP) and 0% for false negatives (FN) was observed, while for the spectral method more than 45% for FP and 0% for FN were obtained. We discuss the advantages and disadvantages of both methods.

Malformación adenomatoidea quística pulmonar en niños / Adenomatoidea cystic lung malformation in children

La enfermedad Adenomatoidea Quística Pulmonar es una enfermedad congénita rara, de difícil diagnóstico, caracterizada por la presencia de múltiples quistes en los pulmones, secundaria a un crecimiento excesivo de los bronquiolos terminarles que no se conectan adecuadamente con los sacos alveolares, puede comprometer a un lóbulo pulmonar o afectar a ambos pulmones. La mortalidad depende de la extensión del tejido pulmonar afectado, la rapidez del diagnóstico y la resolución quirúrgica inmediata, pues la malformación no involuciona y puede complicarse con hiperinsuflación (confundido frecuentemente con Neumotórax) e infecciones repetidas que dañan el tejido pulmonar adyacente. Presentamos el caso clínico de una paciente de 2 meses de edad ingresada al servicio de UCI del HBO por Insuficiencia respiratoria aguda más neumonía, detectándose en la radiografía de tórax imagen sugestiva de Neumotórax que ameritó colocación de tubo de drenaje torácico, que al no obtener resolución se sospecha de esta patología complementándose los estudios diagnósticos con TAC y biopsia pulmonar.