beta-Arrestin1 modulates lymphoid enhancer factor transcriptional activity through interaction with phosphorylated dishevelled proteins.

One aspect of the function of the beta-arrestins is to serve as scaffold or adapter molecules coupling G-protein coupled receptors (GPCRs) to signal transduction pathways distinct from traditional second messenger pathways. Here we report the identification of Dishevelled 1 and Dishevelled 2 (Dvl1 and Dvl2) as beta-arrestin1 (betaarr1) interacting proteins. Dvl proteins participate as key intermediates in signal transmission from the seven membrane-spanning Frizzled receptors leading to inhibition of glycogen synthase kinase-3beta (GSK-3beta), stabilization of beta-catenin, and activation of the lymphoid enhancer factor (LEF) transcription factor. We find that phosphorylation of Dvl strongly enhances its interaction with betaarr1, suggesting that regulation of Dvl phosphorylation and subsequent interaction with betaarr1 may play a key role in the activation of the LEF transcription pathway. Because coexpression of the Dvl kinases, CK1epsilon and PAR-1, with Dvl synergistically activates LEF reporter gene activity, we reasoned that coexpression of betaarr1 with Dvl might also affect LEF-dependent gene activation. Interestingly, whereas betaarr1 or Dvl alone leads to low-level stimulation of LEF (2- to 5-fold), coexpression of betaarr1 with either Dvl1 or Dvl2 leads to a synergistic activation of LEF (up to 16-fold). Additional experiments with LiCl as an inhibitor of GSK-3beta kinase activity indicate that the step affected by betaarr1 is upstream of GSK-3beta and most likely at the level of Dvl. These results identify betaarr1 as a regulator of Dvl-dependent LEF transcription and suggest that betaarr1 might serve as an adapter molecule that can couple Frizzled receptors and perhaps other GPCRs to these important transcription pathways.

Changes of 5-hydroxymethylcytosine distribution during myeloid and lymphoid differentiation of CD34+ cells

BACKGROUND: Hematopoietic stem cell renewal and differentiation are regulated through epigenetic processes. The conversion of 5-methylcytosine into 5-hydroxymethylcytosine (5hmC) by ten-eleven-translocation enzymes provides new insights into the epigenetic regulation of gene expression during development. Here, we studied the potential gene regulatory role of 5hmC during human hematopoiesis.

RESULTS: We used reduced representation of 5-hydroxymethylcytosine profiling (RRHP) to characterize 5hmC distribution in CD34+ cells, CD4+ T cells, CD19+ B cells, CD14+ monocytes and granulocytes. In all analyzed blood cell types, the presence of 5hmC at gene bodies correlates positively with gene expression, and highest 5hmC levels are found around transcription start sites of highly expressed genes. In CD34+ cells, 5hmC primes for the expression of genes regulating myeloid and lymphoid lineage commitment. Throughout blood cell differentiation, intragenic 5hmC is maintained at genes that are highly expressed and required for acquisition of the mature blood cell phenotype. Moreover, in CD34+ cells, the presence of 5hmC at enhancers associates with increased binding of RUNX1 and FLI1, transcription factors essential for hematopoiesis.

CONCLUSIONS: Our study provides a comprehensive genome-wide overview of 5hmC distribution in human hematopoietic cells and new insights into the epigenetic regulation of gene expression during human hematopoiesis.

Heart Transplantation in Patients Older than 65 Years: Worthwhile or Wastage of Organs?

BACKGROUND: Patients older than 65 years have traditionally not been considered candidates for heart transplantation. However, recent studies have shown similar survival. We evaluated immediate and medium-term results in patients older than 65 years compared with younger patients. METHODS: From November 2003 to December 2013, 258 patients underwent transplantation. Children and patients with other organ transplantations were excluded from this study. Recipients were divided into two groups: 45 patients (18%) aged 65 years and older (Group A) and 203 patients (81%) younger than 65 years (Group B). RESULTS: Patients differed in age (67.0 ± 2.2 vs. 51.5 ± 9.7 years), but gender (male 77.8 vs. 77.3%; p = 0.949) was similar. Patients in Group A had more cardiovascular risk factors and ischemic cardiomyopathy (60 vs. 33.5%; p < 0.001). Donors to Group A were older (38.5 ± 11.3 vs. 34.0 ± 11.0 years; p = 0.014). Hospital mortality was 0 vs. 5.9% (p = 0.095) and 1- and 5-year survival were 88.8 ± 4.7 versus 86.8 ± 2.4% and 81.5 ± 5.9 versus 77.2 ± 3.2%, respectively. Mean follow-up was 3.8 ± 2.7 versus 4.5 ± 3.1 years. Incidence of cellular/humoral rejection was similar, but incidence of cardiac allograft vasculopathy was higher (15.6 vs. 7.4%; p = 0.081). Incidence of diabetes de novo was similar (p = 0.632), but older patients had more serious infections in the 1st year (p = 0.018). CONCLUSION: Heart transplantation in selected older patients can be performed with survival similar to younger patients, hence should not be restricted arbitrarily. Incidence of infections, graft vascular disease, and malignancies can be reduced with a more personalized approach to immunosuppression. Allocation of donors to these patients does not appear to reduce the possibility of transplanting younger patients.

Strategies to improve outcome following the transplantation of organs from brain-dead donors

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Heart Transplantation in Patients Older than 65 Years: Worthwhile or Wastage of Organs?

BACKGROUND: Patients older than 65 years have traditionally not been considered candidates for heart transplantation. However, recent studies have shown similar survival. We evaluated immediate and medium-term results in patients older than 65 years compared with younger patients. METHODS: From November 2003 to December 2013, 258 patients underwent transplantation. Children and patients with other organ transplantations were excluded from this study. Recipients were divided into two groups: 45 patients (18%) aged 65 years and older (Group A) and 203 patients (81%) younger than 65 years (Group B). RESULTS: Patients differed in age (67.0 ± 2.2 vs. 51.5 ± 9.7 years), but gender (male 77.8 vs. 77.3%; p = 0.949) was similar. Patients in Group A had more cardiovascular risk factors and ischemic cardiomyopathy (60 vs. 33.5%; p < 0.001). Donors to Group A were older (38.5 ± 11.3 vs. 34.0 ± 11.0 years; p = 0.014). Hospital mortality was 0 vs. 5.9% (p = 0.095) and 1- and 5-year survival were 88.8 ± 4.7 versus 86.8 ± 2.4% and 81.5 ± 5.9 versus 77.2 ± 3.2%, respectively. Mean follow-up was 3.8 ± 2.7 versus 4.5 ± 3.1 years. Incidence of cellular/humoral rejection was similar, but incidence of cardiac allograft vasculopathy was higher (15.6 vs. 7.4%; p = 0.081). Incidence of diabetes de novo was similar (p = 0.632), but older patients had more serious infections in the 1st year (p = 0.018). CONCLUSION: Heart transplantation in selected older patients can be performed with survival similar to younger patients, hence should not be restricted arbitrarily. Incidence of infections, graft vascular disease, and malignancies can be reduced with a more personalized approach to immunosuppression. Allocation of donors to these patients does not appear to reduce the possibility of transplanting younger patients.

Tratamiento del rechazo mediado por anticuerpos en pacientes trasplantados renales revisión sistemática

Antecedentes: El trasplante renal es la mejor alternativa terapéutica para la enfermedad renal crónica terminal. Los medicamentos inmunosupresores previenen el rechazo. El rechazo mediado por anticuerpos es frecuente y disminuye la función y duración del injerto. Objetivo: Evaluar sistemáticamente la evidencia disponible relacionada con la eficacia y seguridad del tratamiento para el rechazo mediado por anticuerpos en pacientes trasplantados renales. Metodologia: Revisión sistemática en bases de datos MEDLINE, EMBASE, Scopus y Biblioteca virtual de la salud. Literatura gris google scholar, google academico, www.clinicaltrialsregister.eu, and https://clinicaltrials.gov/. Búsqueda manual referencias artículos pre-seleccionados así como de revisiones previamente publicadas. Se siguieron las recomendacioes guia PRISMA para la identificacion de artículos potenciales, tamizaje y selección teniendo en cuenta los criterios de inclusion. Extracción datos de acuerdo a las variables, revisión calidad de los artículos elegidos utilizando evaluación riesgo de segos de Cochrane. Resultados: Se seleccionaron 9 ensayos clínicos publicados entre 1980 y 2016, incluyeron 222 pacientes (113 brazo de intervención y 109 en el control), seguimiento promedio 16 meses. Intervenciones evaluadas plasmaféresis, inmunoadsorción y rituximab. Hubo una amplia heterogeneidad en la definición de criterios de inclusión, criterios diagnósticos de rechazo y medidas de evaluación de eficacia de las intervenciones. Tres estudios encontraron diferencias estadísticamente significativas entre los grupos de tratamiento. Conclusiones: La evidencia sobre la eficacia de los tratamientos del rechazo mediado por anticuerpos en injertos renales es de baja calidad. Son necesarios ensayos clínicos controlados para poder definir el tratamiento óptimo de estos pacientes.

Phytate-phosphorus and phytase contents on the relative weight of organs, intestinal morphometry and performance of broilers.

ABSTRACT: In order to evaluate the efficiency of phytase in diets with low and high phytate phosphorus (PP) content, as a consequence of wheat bran inclusion, on the relative weight of organs, intestinal morphometry and performance, three hundred and eighty-four male Cobb500 broilers were housed in metabolic cages. Animals were assigned into four treatments in a 2x2 factorial scheme in a randomized block design with eight replicates of 12 birds each. From 11 days of age birds received experimental diets, which consisted of: Diet low in PP; Diet low in PP with phytase (500FTU kg-1); Diet with a high PP and Diet with a high PP with phytase (500FTU kg-1). At 22 and 32 days of age two birds were slaughtered in order to collect gizzard, heart, liver, cecum, cloacal bursa, and at 32 days, a portion of the duodenum, jejunum and ileum was collected for morphometric evaluation. From 22 to 32 days of age average feed intake, average weight gain, average body weight and feed conversion ratio were also evaluated. Data were subjected to analysis of variance, fixed effects of diet and phytase and interaction between factors as well as the random block effects were tested. There was no significant interaction for the variables studied, concluding that phytase in diets with low or high phytate phosphorus content did not change the relative weight of organs, intestinal morphometrics and performance; only isolated effects were observed. RESUMO: Para avaliar a eficiência da fitase em dietas com baixo e alto teor de fósforo fítico (PP), em função da inclusão ou não do farelo de trigo, sobre o peso relativo de órgãos, morfometria intestinal e desempenho, foram alojados 384 frangos de corte, machos da linhagem Cobb500, em gaiolas metabólicas. Os animais foram distribuídos em quatro tratamentos em um arranjo fatorial 2x2 em delineamento de blocos casualizados com oito repetições e 12 aves por unidade experimental (UE). A partir de 11 dias de idade as aves receberam as dietas experimentais, que consistiram em: Dieta com baixo teor de PP; Dieta com baixo teor de PP com fitase (500FTU kg-1); Dieta com alto teor de PP e Dieta com alto teor de PP com fitase (500FTU kg-1). Aos 22 e 32 dias de idade foram abatidas duas aves por UE para coletar a moela, coração, fígado, ceco, bolsa cloacal, e aos 32 dias foi coletada uma porção do duodeno, jejuno e íleo para avaliação da morfometria. No período de 22 a 32 dias de idade foram avaliados o consumo médio de ração, ganho de peso médio, peso médio corporal e a conversão alimentar. Os dados foram submetidos à análise de variância, onde foram testados os efeitos fixos de dieta e fitase e a interação entre os fatores, bem como o efeito aleatório de bloco. Não foi observada interação significativa para nenhuma das variáveis estudadas, concluindo-se que a fitase em dietas com baixo ou alto de PP não altera o peso relativo dos órgãos, a morfometria intestinal e o desempenho, apenas efeitos isolados foram observados.

Washout hole for bi-ventricular assist device (BVAD) centrifugal blood pump

The shortage of donor hearts for patients with end stage heart failure has accelerated the development of ventricular assist devices (VAD) that act as a replacement heart. Mechanical devices involving pulsatile, axial and centrifugal devices have been proposed. Recent clinical developments indicate that centrifugal devices are not only beneficial for bridge to transplantation applications, but may also aid myocardial recovery. The results of a recent study have shown that patients who received a VAD have extended lives and improved quality of life compared to recipients of drug therapy. Unfortunately 25% of these patients develop right heart failure syndrome, sepsis and multi-organ failure. It was reported that 17% of patients initially receiving an LVAD later required a right ventricular assist device (RVAD). Hence, current research focus is in the development of a bi-ventricular assist device (BVAD). Current BVAD technology is either too bulky or necessitates having to implant two pumps working independently. The latter requires two different controllers for each pump leading to the potential complication of uneven flow dynamics and the requirements for a large amount of body space. This paper illustrates the combination of the LVAD and RVAD as one complete device to augment the function of both the left and right cardiac chambers with double impellers. The proposed device has two impellers rotating in counter directions, hence eliminating the necessity of the body muscles and tubing/heart connection to restrain the pump. The device will also have two separate chambers with independent rotating impeller for the left and right chambers. A problem with centrifugal impellers is the fluid stagnation underneath the impeller. This leads to thrombosis and blood clots.This paper presents the design, construction and location of washout hole to prevent thrombus for a Bi-VAD centrifugal pump. Results using CFD will be used to illustrate the superiority of our design concept in terms of preventing thrombus formation and hemolysis.

Computational fluid dynamics of a centrifugal heart pump as biventricular assist device(BVAD)

The results of a recent study have shown that there is a severe shortage of donor hearts to meet the demand of patients suffering from acute heart failures, and patients who received a left ventricular assist device (LVAD) have extended lives. However, some of them develop right heart failure syndrome, and these patients required a right ventricular assist device (RVAD). Hence, current research focus is in the development of a bi-ventricular assist device (Bi-VAD). Computational Fluid Dynamics (CFD) is useful for estimating blood damage for design of a Bi-VAD centrifugal heart pump to meet the demand of the left and right ventricles of a normal hearts with a flow rate of 5 lit/min and the supply pressure of 100 mmHg for the left ventricle and 20 mmHg for the right ventricle. Numerical studies have been conducted to predict pressure, flow rate, the velocity profiles, and streamlines in a continuous flow Bi-VAD using. Based on the predictions of numerical simulations, only few flow regions in the Bi-VAD exhibited signs of velocity profiles and stagnation points, thereby signifying potentially low levels of thrombogenesis.

Knowing a donor and identifying as one : determinants of people's willingness for related and anonymous living donation in Australia

While LRD (living donation to a genetically/emotionally related recipient) is well established in Australia, LAD (living anonymous donation to a stranger) is rare. Given the increasing use of LAD overseas, Australia may likely follow suit. Understanding the determinants of people’s willingness for LAD is essential but infrequently studied in Australia. Consequently, we compared the determinants of people’s LRD and LAD willingness, and assessed whether these determinants differed according to type of living donation. We surveyed 487 health students about their LRD and LAD willingness, attitudes, identity, prior experience with blood and organ donation, deceased donation preference, and demographics. We used Structural Equation Modelling (SEM) to identify the determinants of willingness for LRD and LAD and paired sample t-tests to examine differences in LRD and LAD attitudes, identity, and willingness. Mean differences in willingness (LRD 5.93, LAD 3.92), attitudes (LRD 6.43, LAD 5.53), and identity (LRD 5.69, LAD 3.58) were statistically significant. Revised SEM models provided a good fit to the data (LRD: x2 (41) = 67.67, p = 0.005, CFI = 0.96, RMSEA = 0.04; LAD: x2 (40) = 79.64, p < 0.001, CFI = 0.95, RMSEA = 0.05) and explained 45% and 54% of the variation in LRD and LAD willingness, respectively. Four common determinants of LRD and LAD willingness emerged: identity, attitude, past blood donation, and knowing a deceased donor. Religious affiliation and deceased donation preference predicted LAD willingness also. Identifying similarities and differences in these determinants can inform future efforts aimed at understanding people’s LRD and LAD willingness and the evaluation of potential living donor motives. Notably, this study highlights the importance of people’s identification as a living donor as a motive underlying their willingness to donate their organs while living.

Celebrating difference/censoring difference? : Marie Chouinard’s bODY rEMIX

This paper examines performances that defy established representations of disease, deformity and bodily difference. Historically, the ‘deformed’ body has been cast – onstage and in sideshows – as flawed, an object of pity, or an example of the human capacity to overcome. Such representations define the boundaries of the ‘normal’ body by displaying its Other. They bracket the ‘abnormal’ body off as an example of deviance from the ‘norm’, thus, paradoxically, decreasing the social and symbolic visibility (and agency) of disabled people. Yet, in contemporary theory and culture, these representations are reappropriated – by disabled artists, certainly, but also as what Carrie Sandahl has called a ‘master trope’ for representing a range of bodily differences. In this paper, I investigate this phenomenon. I analyse French Canadian choreographer Marie Chouinard’s bODY rEMIX/gOLDBERG vARIATIONS, in which 10 able-bodied dancers are reborn as bizarre biotechnical mutants via the use of crutches, walkers, ballet shoes and barres as prosthetic pseudo-organs. These bodies defy boundaries, defy expectations, develop new modes of expression, and celebrate bodily difference. The self-inflicted pain dancers experience during training is cast as a ‘disablement’ that is ultimately ‘enabling’. I ask what effect encountering able bodies celebrating ‘dis’ or ‘diff’ ability has on audiences. Do we see the emergence of a once-repressed Other, no longer silenced, censored or negated? Or does using ‘disability’ to express the dancers’ difference and self-determination usurp a ‘trope’ by which disabled people themselves might speak back to the dominant culture, creating further censorship?

Determining the psychosocial predictors of living, living-related, and posthumous organ donation

The worldwide organ shortage occurs despite people’s positive organ donation attitudes. The discrepancy between attitudes and behaviour is evident in Australia particularly, with widespread public support for organ donation but low donation and communication rates. This problem is compounded further by the paucity of theoretically based research to improve our understanding of people’s organ donation decisions. This program of research contributes to our knowledge of individual decision making processes for three aspects of organ donation: (1) posthumous (upon death) donation, (2) living donation (to a known and unknown recipient), and (3) providing consent for donation by communicating donation wishes on an organ donor consent register (registering) and discussing the donation decision with significant others (discussing). The research program used extended versions of the Theory of Planned Behaviour (TPB) and the Prototype/Willingness Model (PWM), incorporating additional influences (moral norm, self-identity, organ recipient prototypes), to explicate the relationship between people’s positive attitudes and low rates of organ donation behaviours. Adopting the TPB and PWM (and their extensions) as a theoretical basis overcomes several key limitations of the extant organ donation literature including the often atheoretical nature of organ donation research, thefocus on individual difference factors to construct organ donor profiles and the omission of important psychosocial influences (e.g., control perceptions, moral values) that may impact on people’s decision-making in this context. In addition, the use of the TPB and PWM adds further to our understanding of the decision making process for communicating organ donation wishes. Specifically, the extent to which people’s registering and discussing decisions may be explained by a reasoned and/or a reactive decision making pathway is examined (Stage 3) with the novel application of the TPB augmented with the social reaction pathway in the PWM. This program of research was conducted in three discrete stages: a qualitative stage (Stage 1), a quantitative stage with extended models (Stage 2), and a quantitative stage with augmented models (Stage 3). The findings of the research program are reported in nine papers which are presented according to the three aspects of organ donation examined (posthumous donation, living donation, and providing consent for donation by registering or discussing the donation preference). Stage One of the research program comprised qualitative focus groups/interviews with university students and community members (N = 54) (Papers 1 and 2). Drawing broadly on the TPB framework (Paper 1), content analysed responses revealed people’s commonly held beliefs about the advantages and disadvantages (e.g., prolonging/saving life), important people or groups (e.g., family), and barriers and motivators (e.g., a family’s objection to donation), related to living and posthumous organ donation. Guided by a PWM perspective, Paper Two identified people’s commonly held perceptions of organ donors (e.g., altruistic and giving), non-donors (e.g., self-absorbed and unaware), and transplant recipients (e.g., unfortunate, and in some cases responsible/blameworthy for their predicament). Stage Two encompassed quantitative examinations of people’s decision makingfor living (Papers 3 and 4) and posthumous (Paper 5) organ donation, and for registering and discussing donation wishes (Papers 6 to 8) to test extensions to both the TPB and PWM. Comparisons of health students’ (N = 487) motivations and willingness for living related and anonymous donation (Paper 3) revealed that a person’s donor identity, attitude, past blood donation, and knowing a posthumous donor were four common determinants of willingness, with the results highlighting students’ identification as a living donor as an important motive. An extended PWM is presented in Papers Four and Five. University students’ (N = 284) willingness for living related and anonymous donation was tested in Paper Four with attitude, subjective norm, donor prototype similarity, and moral norm (but not donor prototype favourability) predicting students’ willingness to donate organs in both living situations. Students’ and community members’ (N = 471) posthumous organ donation willingness was assessed in Paper Five with attitude, subjective norm, past behaviour, moral norm, self-identity, and prior blood donation all significantly directly predicting posthumous donation willingness, with only an indirect role for organ donor prototype evaluations. The results of two studies examining people’s decisions to register and/or discuss their organ donation wishes are reported in Paper Six. People’s (N = 24) commonly held beliefs about communicating their organ donation wishes were explored initially in a TPB based qualitative elicitation study. The TPB belief determinants of intentions to register and discuss the donation preference were then assessed for people who had not previously communicated their donation wishes (N = 123). Behavioural and normative beliefs were important determinants of registering and discussing intentions; however, control beliefs influenced people’s registering intentions only. Paper Seven represented the first empirical test of the role of organ transplant recipient prototypes (i.e., perceptions of organ transplant recipients) in people’s (N = 465) decisions to register consent for organ donation. Two factors, Substance Use and Responsibility, were identified and Responsibility predicted people’s organ donor registration status. Results demonstrated that unregistered respondents were the most likely to evaluate transplant recipients negatively. Paper Eight established the role of organ donor prototype evaluations, within an extended TPB model, in predicting students’ and community members’ registering (n = 359) and discussing (n = 282) decisions. Results supported the utility of an extended TPB and suggested a role for donor prototype evaluations in predicting people’s discussing intentions only. Strong intentions to discuss donation wishes increased the likelihood that respondents reported discussing their decision 1-month later. Stage Three of the research program comprised an examination of augmented models (Paper 9). A test of the TPB augmented with elements from the social reaction pathway in the PWM, and extensions to these models was conducted to explore whether people’s registering (N = 339) and discussing (N = 315) decisions are explained via a reasoned (intention) and/or social reaction (willingness) pathway. Results suggested that people’s decisions to communicate their organ donation wishes may be better explained via the reasoned pathway, particularly for registering consent; however, discussing also involves reactive elements. Overall, the current research program represents an important step toward clarifying the relationship between people’s positive organ donation attitudes but low rates of organ donation and communication behaviours. Support has been demonstrated for the use of extensions to two complementary theories, the TPB and PWM, which can inform future research aiming to explicate further the organ donation attitude-behaviour relationship. The focus on a range of organ donation behaviours enables the identification of key targets for future interventions encouraging people’s posthumous and living donation decisions, and communication of their organ donation preference.