Characterization of antibody binding to swine leukocyte antigen class II

Indiana University-Purdue University Indianapolis (IUPUI)Though the elimination of carbohydrate xenoantigens has reduced the antibody barrier to clinical xenotransplantation, identification of additional targets of rejection could further increase the immunologic compatibility of pig tissues with humans. Many patients in need of organ transplantation have antibodies to proteins encoded by the human major histocompatibility complex (MHC) which have high similarity to their swine homologs. The goal of this thesis was to determine if the class II genes of the swine MHC can bind human antibodies. To characterize antibody binding effect to class II swine leukocyte antigens (SLA), a constitutively positive SLA class II cell was created through transfection with the human class II transactivator (CIITA). Cells expressing only SLA-DR or SLA-DQ were also created using the CRISPR/Cas9 gene knockout tools. These various lines were incubated with human sera and tested for binding to IgM and IgG in a flow cytometry crossmatch (FCXM). The results demonstrate reliable antibody binding to each of the SLA class II –DR and –DQ derivatives. A two-way paired t-test revealed statistical difference in total sera binding between to the DR(+)DQ(+) and DR(-)DQ(-) clones for IgG (p = 0.0059) but not IgM (p = 0.2460). Looking at the subset of individuals with and without anti-HLA class II sensitization, statistical difference was noted for IgG (p = 0.0229) but not IgM (p = 0.3045). Examining further the role of DR(+) vs DQ(+), statistical analysis revealed difference in the DR(+)DQ(-) vs. the DR(-)DQ(+) FCXM (p = 0.0099), the DR(+)DQ(-) vs. the DR(+)DQ(+) FCXM (p = 0.0192), and the DR(-)DQ(-) parent vs. DR(+)DQ(+) FCXM (p = 0.0329). No difference was found in the DR(-)DQ(+) vs. DR(+)DQ(+) FCXM (p = 0.1601). The results of this project suggest that SLA class II, specifically SLA-DQ, could be a target of antibody binding and cross-reactive anti-HLA class II antibodies may be capable of binding SLA class II

Reading practices to teach Didactics of Social Sciences in initial teacher training. Considering teaching work from the perspective of Professional Didactics

La lectura de textos suele ser la práctica predominante para enseñar ciencias sociales en el Nivel Superior, práctica que en general se supone ya adquirida por lxs estudiantes y por ello no se enseña. Desde la perspectiva que adoptamos, la lectura es central para construir conocimientos y, por lo tanto, debería constituirse en objeto de enseñanza en la formación docente. Este artículo recorre una investigación que explora y analiza diversas prácticas de lectura –y los supuestos sobre las mismas- implementadas por una docente para enseñar Didáctica de las Ciencias Sociales en la formación inicial de maestrxs. Asimismo, desde el enfoque de la Didáctica Profesional y la clínica de la actividad buscamos promover un proceso reflexivo sobre la actividad docente y una mayor comprensión de las situaciones profesionales. Mediante el diálogo entre docente e investigadora, procuramos el encuentro de la profesora con las huellas de su actividad, con el propósito de generar una reflexividad que ayude a recrearla y elaborar formas alternativas de enseñanza.Reading texts is usually the predominant practice for teaching social sciences at the higher education level, a practice that is generally assumed to have been already acquired by students and therefore is not taught. From the perspective we adopt, reading is central to the construction of knowledge and, therefore, it should constitute a teaching object in teacher training. This article reviews a research that explores and analyzes different reading practices – and the assumptions about them– implemented by a teacher to teach Didactics of Social Sciences in initial teacher training. Likewise, from the perspective of Professional Didactics and the clinic of the activity, we seek to promote a reflective process on teaching and a better understanding of professional situations. Through the dialogue between teacher and researcher, we seek to facilitate the encounter of the teacher with the traces of her activity, for the purpose of generating a reflexivity that helps to recreate it and to elaborate alternative forms of teaching.Facultad de Humanidades y Ciencias de la Educació

Using movies to assess cognitive and neural functioning in temporal lobe epilepsy

Individuals with focal epilepsy whose seizures are poorly managed with medication will often undergo extensive investigations to determine surgical candidacy. These investigations make use of various methodologies to localize normal and pathological brain tissue. Temporal lobe epilepsy (TLE), the most common type of medically refractory epilepsy, can often be detected through structural and functional changes to the affected temporal lobe. On neuropsychological assessment, this dysfunction may be inferred from material-specific memory deficits, with left TLE associated with reduced verbal memory and right TLE associated with reduced visual memory. Although, simple, artificial stimuli may be useful when a clearly lateralizing pattern emerges on testing, other memory deficits may be more subtle or recruit both temporal lobes. Our primary goal with this work was to investigate the utility of a brief, engaging audiovisual film clip to assess temporal-lobe dysfunction in TLE. The first two investigations offer an evaluation of the psychometric properties of a memory test designed to investigate various aspects of memory for the movie. In the first investigation, we used a variety of recall- and recognition-based measures derived from the movie-memory test, whereas the second investigation focused on temporal memory, memory for the temporal context of events in the movie. Both chapters demonstrate the sensitivity of movie-based measures to detect cognitive deficits in TLE. In fact, movie measures appear to be more sensitive than some commonly used standardized tests. The third investigation integrated structural and movie-driven functional neuroimaging measures with performance on the movie-memory test to investigate the combined utility of these methodologies in studying temporal-lobe dysfunction in TLE. Measures of hippocampal volume and connectivity could sensitively distinguish participants with TLE from controls, and abnormal neuroimaging markers could be directly related to cognitive measures to better understand their behavioural consequences. In summary, the current investigations suggest a promising role for movie-based assessment tools in TLE, and motivate their further validation as potential clinical tools to inform surgical planning in TLE

Teach about the recent past. Experiences in secondary schools and teacher training institutes based on an interactive documentary about El Campito

Este artículo recupera aspectos de una investigación realizada desde la Universidad Pedagógica Nacional en torno a la enseñanza de temas de agenda contemporánea -como la historia reciente y la construcción de la memoria- y el uso de medios digitales. A partir de un proyecto colaborativo, investigadoras/es y docentes analizamos un documental interactivo producido por Huella Digital y la Universidad Nacional General Sarmiento que reconstruye el centro clandestino El Campito. Luego invitamos a docentes y estudiantes de escuelas secundarias y de la formación docente inicial a recorrerlo. Nos proponemos indagar, en distintas escenas de clase, qué representaciones construyen las y los alumnos sobre el terrorismo de estado a partir de objetos digitales. Por un lado, exploramos qué suscita el documental desde un plano sensible vinculado con la empatía en tanto puerta de entrada al conocimiento en ciencias sociales. Por otro lado, analizamos lo que el recurso permite a partir de su diseño, la forma en que organiza la información que provee y su impacto en el contexto de situaciones de clase. Por último, indagamos también sobre las interpretaciones que se producen a partir de las representaciones que propone el documental.Abstract: This article recovers aspects of a research carried out from the National Pedagogical University (Argentina) about the teaching of contemporary agenda topics -such as recent history and the construction of memory- and the use of digital media. Based on a collaborative project, researchers and teachers analyse an interactive documentary produced by Huella Digital and the UNGS that recreates the El Campito clandestine detention center. Then we invite teachers, Initial Teacher Training and High School students to explore it. We aim to investigate which representations about state terrorism are developed by the students in different classroom scenarios using digital objects. First, we explore what the documentary provokes from a sensible level linking empathy as a gateway to social sciences subjects. Also, we analyse what this production allows due to its design, the way it organizes the information provided by it and its impact in the context of a classroom setting. Finally, we inquire about the interpretations generated from the representations suggested in the documentary.Facultad de Humanidades y Ciencias de la Educació

Porcine iGb3s gene silencing provides minimal benefit for clinical xenotransplantation

Background The Galα(1,3)Gal epitope (α-GAL), created by α-1,3-glycosyltransferase-1 (GGTA1), is a major xenoantigen causing hyperacute rejection in pig-to-primate and pig-to-human xenotransplantation. In response, GGTA1 gene-deleted pigs have been generated. However, it is unclear whether there is a residual small amount of α-Gal epitope expressed in GGTA1−/− pigs. Isoglobotrihexosylceramide synthase (iGb3s), another member of the glycosyltransferase family, catalyzes the synthesis of isoglobo-series glycosphingolipids with an α-GAL-terminal disaccharide (iGb3), creating the possibility that iGb3s may be a source of α-GAL epitopes in GGTA1−/− animals. The objective of this study was to examine the impact of silencing the iGb3s gene (A3GalT2) on pig-to-primate and pig-to-human immune cross-reactivity by creating and comparing GGTA1−/− pigs to GGTA1−/−- and A3GalT2−/−-double-knockout pigs. Methods We used the CRISPR/Cas 9 system to target the GGTA1 and A3GalT2 genes in pigs. Both GGTA1 and A3GalT2 genes are functionally inactive in humans and baboons. CRISPR-treated cells used directly for somatic cell nuclear transfer produced single- and double-gene-knockout piglets in a single pregnancy. Once grown to maturity, the glycosphingolipid profile (including iGb3) was assayed in renal tissue by normal-phase liquid chromatography. In addition, peripheral blood mononuclear cells (PBMCs) were subjected to (i) comparative cross-match cytotoxicity analysis against human and baboon serum and (ii) IB4 staining for α-GAL/iGb3. Results Silencing of the iGb3s gene significantly modulated the renal glycosphingolipid profile and iGb3 was not detected. Moreover, the human and baboon serum PBMC cytotoxicity and α-GAL/iGb3 staining were unchanged by iGb3s silencing. Conclusions Our data suggest that iGb3s is not a contributor to antibody-mediated rejection in pig-to-primate or pig-to-human xenotransplantation. Although iGb3s gene silencing significantly changed the renal glycosphingolipid profile, the effect on Galα3Gal levels, antibody binding, and cytotoxic profiles of baboon and human sera on porcine PBMCs was neutral

Silencing porcine CMAH and GGTA1 genes significantly reduces xenogeneic consumption of human platelets by porcine livers

BACKGROUND: A profound thrombocytopenia limits hepatic xenotransplantation in the pig-to-primate model. Porcine livers also have shown the ability to phagocytose human platelets in the absence of immune-mediated injury. Recently, inactivation of the porcine ASGR1 gene has been shown to decrease this phenomenon. Inactivating GGTA1 and CMAH genes has reduced the antibody-mediated barrier to xenotransplantation; herein, we describe the effect that these modifications have on xenogeneic consumption of human platelets in the absence of immune-mediated graft injury. METHODS: Wild type (WT), ASGR1, GGTA1, and GGTA1CMAH knockout pigs were compared for their xenogeneic hepatic consumption of human platelets. An in vitro assay was established to measure the association of human platelets with liver sinusoidal endothelial cells (LSECs) by immunohistochemistry. Perfusion models were used to measure human platelet uptake in livers from WT, ASGR1, GGTA1, and GGTA1 CMAH pigs. RESULTS: GGTA1, CMAH LSECs exhibited reduced levels of human platelet binding in vitro when compared with GGTA1 and WT LSECs. In a continuous perfusion model, GGTA1 CMAH livers consumed fewer human platelets than GGTA1 and WT livers. GGTA1 CMAH livers also consumed fewer human platelets than ASGR1 livers in a single-pass model. CONCLUSIONS: Silencing the porcine carbohydrate genes necessary to avoid antibody-mediated rejection in a pig-to-human model also reduces the xenogeneic consumption of human platelets by the porcine liver. The combination of these genetic modifications may be an effective strategy to limit the thrombocytopenia associated with pig-to-human hepatic xenotransplantation

Low Mate Encounter Rate Increases Male Risk Taking in a Sexually Cannibalistic Praying Mantis

Male praying mantises are forced into the ultimate trade-off of mating versus complete loss of future reproduction if they fall prey to a female. The balance of this trade-off will depend both on (1) the level of predatory risk imposed by females and (2) the frequency of mating opportunities for males. We report the results of a set of experiments that examine the effects of these two variables on male risk-taking behavior and the frequency of sexual cannibalism in the praying mantis Tenodera sinensis. We experimentally altered the rate at which males encountered females and measured male approach and courtship behavior under conditions of high and low risk of being attacked by females. We show that male risk taking depends on prior access to females. Males with restricted access to females showed greater risk-taking behavior. When males were given daily female encounters, they responded to greater female-imposed risk by slowing their rate of approach and remained a greater distance from a potential mate. In contrast, males without recent access to mates were greater risk-takers; they approached females more rapidly and to closer proximity, regardless of risk. In a second experiment, we altered male encounter rate with females and measured rates of sexual cannibalism when paired with hungry or well-fed females. Greater risk-taking behavior by males with low mate encounter rates resulted in high rates of sexual cannibalism when these males were paired with hungry females

Bovine pericardium retail preserved in glutaraldehyde and used as a vascular patch

<p>Abstract</p> <p>Background</p> <p>In this study we evaluated the performance of bovine pericardium preserved in glutaraldehyde used as a vascular patch.</p> <p>Methods</p> <p>Fourteen young pigs, six females and eight males, weighting 10.3 - 18.4 kg were used in our study. We implanted three remnants in each pig, two in the abdominal aorta and one was juxtaposed to the peritoneum. The smooth face (SF) and rough face (RF) of each remnant were implanted turned to the vessel inner portion and one remnant was juxtaposed to the peritoneum. The animals were sacrificed in 4.5 - 8 months after surgery (75 - 109 kg). The remnants were assessed for aorta wall, fibroses formation in inner apposition and calcification related to the face turned to the vessel inner portion.</p> <p>Results</p> <p>The rough face showed a lower dilatation level compared to the face implanted in adjacent aorta. There was no difference between intensity and/or incidence of graft calcification when the superficies were compared. The bovine pericardium preserved in glutaraldehyde did not show alterations in its structure when implanted with different faces turned to the inner portion of vessel.</p> <p>Conclusion</p> <p>When turned to the inner portion of the vessel, the rough face of the remnant presented a lower dilatation in relation to the adjacent aorta and a better quality of endothelium layer and did not show a difference between intensity and/or incidence of graft calcification.</p