Mice lacking the intestinal and renal neutral amino acid transporter slc6a19 demonstrate the relationship between dietary protein intake and amino acid malabsorption

Dietary protein restriction has beneficial impacts on metabolic health. B0AT1 (SLC6A19) is the major transporter of neutral amino acids at the intestinal epithelia and absorbs the bulk of the diet-derived neutral amino acids from the intestinal lumen. It also reabsorbs neutral amino acids in the renal proximal tubules. Mice lacking B0AT1 show cellular outcomes of protein restriction, such as high FGF21 levels and low mTORC1 activity. Moreover, they have improved glucose homeostasis and resist diet-induced obesity. In this study, we investigated the relationship between protein restriction and dietary protein intake in C57Bl6/J wild-type (wt) and SLC6A19-knockout (SLC6A19ko) mice. When SLC6A19ko mice were fed diets containing 5%, 25%, or 52% of their total calories derived from protein, no differences in food intake or weight gain were observed. All essential amino acids significantly positively correlated with increasing dietary casein content in the wt mice. The SLC6A19ko mice showed reduced postprandial levels of essential amino acids in plasma, particularly following high-protein diets. Upon fasting, essential amino acids were the same in the wt and SLC6A19ko mice due to reduced amino acid catabolism. Bacterial metabolites originating from amino acid fermentation correlated with the dietary protein content, but showed a complex profile in the blood of the SLC6A19ko mice. This study highlights the potential of SLC6A19 as a knock-out or inhibition target to induce protein restriction for the treatment of metabolic disorders.This research was funded in part by NHMRC, grant number GNT 1128442

Development of Biomarkers for Inhibition of SLC6A19 - A Potential Target to treat Metabolic Disorders

Dietary protein restriction has beneficial impacts on metabolic health. SLC6A19 (B0AT1) is the major transporter of neutral amino acids at the intestinal epithelium and absorbs the bulk of the diet-derived neutral amino acids from the intestinal lumen. It also reabsorbs neutral amino acids in the renal proximal tubules. Mice lacking SLC6A19 show signs of protein restriction, such as high FGF21 levels and low mTORC1 activity. Moreover, they have improved glucose homeostasis and resist diet-induced obesity. Pharmacological blockage of this transporter could be used to induce protein restriction and to treat metabolic diseases such as type 2 diabetes, fatty liver and phenylketonuria. A few novel inhibitors of SLC6A19 have recently been identified using in vitro compound screening, but it remains unclear whether these compounds block the transporter in vivo. To evaluate the efficacy of SLC6A19 inhibitors, biomarkers are required that can reliably detect successful inhibition of the transporter in mice. A gas chromatography mass spectrometry (GC-MS)-based untargeted metabolomics approach was used to discriminate global metabolite profiles in plasma, urine and faecal samples from SLC6A19ko and wt mice. Due to inefficient absorption in the intestine and lack of reabsorption in the kidney, significantly elevated amino acids levels were observed in urine and faecal samples. By contrast, a few neutral amino acids were reduced in the plasma of male SLC6A19ko mice as compared to other biological samples. Metabolites of bacterial protein fermentation such as p-cresol-glucuronide and 3-indole-propionic acid were more abundant in SLC6A19ko mice, indicating protein malabsorption of dietary amino acids. Consistently, plasma appearance rates of [14C]-labelled neutral amino acids were delayed in SLC6A19ko mice as compared to wt after intra-gastric administration of a mixture of amino acids. Receiver operating characteristic (ROC) curve analysis was used to validate the potential use of these metabolites as biomarkers. Feasibility of volatile biomarkers in breath was also explored in this thesis. While I did not identify any breath-based volatiles due to limitation in method development, I identified a few volatile organic compounds (VOCs) in the headspace of mouse urine that illustrate the potential of breath analysis in the analysis of SLC6A19 activity. Moreover, I also investigated the relationship between protein restriction and dietary protein intake in wt and SLC6A19ko mice. When SLC6A19ko mice were fed diets containing 5%, 25%, or 52% of their total calories derived from protein, no differences in food intake or weight gain were observed. All essential amino acids positively correlated with increasing dietary casein content in the wt mice. The SLC6A19ko mice showed reduced postprandial levels of essential amino acids in plasma, particularly following high-protein diets. Upon fasting, essential amino acids were the same in wt and SLC6A19ko mice due to reduced amino acid catabolism. Bacterial metabolites originating from amino acid fermentation correlated with the dietary protein content, but showed a complex profile in the blood of the SLC6A19ko mice. The findings in this study provide putative metabolite biomarkers that can be used to detect protein malabsorption and the inhibition of this transporter in intestine and kidney. It also highlights the potential of SLC6A19 as a knock-out or inhibition target to induce protein restriction for the treatment of metabolic disorders

Social relationship analysis using state-of-the-art embeddings.

Detection of human relationships from their interactions on social media is a challenging problem with a wide range of applications in different areas, like targeted marketing, cyber-crime, fraud, defense, planning, and human resource, to name a few. All previous work in this area has only dealt with the most basic types of relationships. The proposed approach goes beyond the previous work to efficiently handle the hierarchy of social relationships. This article introduces a novel technique named Quantifiable Social Relationship (QSR) analysis for quantifying social relationships to analyze relationships between agents from their textual conversations. QSR uses cross-disciplinary techniques from computational linguistics and cognitive psychology to identify relationships. QSR utilizes sentiment and behavioral styles displayed in the conversations for mapping them onto level II relationship categories. Then, for identifying the level III relationship categories, QSR uses level II relationships, sentiments, interactions, and word embeddings as key features. QSR employs natural language processing techniques for feature engineering and state-of-the-art embeddings generated by word2vec, global vectors (glove), and bidirectional encoder representations from transformers (bert). QSR combines the intrinsic conversational features with word embeddings for classifying relationships. QSR achieves an accuracy of up to 89% for classifying relationship subtypes. The evaluation shows that QSR can accurately identify the hierarchical relationships between agents by extracting intrinsic and extrinsic features from textual conversations between agents

Gender and Forced Displacement in Humanitarian Policy Discourse: The Missing Link

This paper reports on a study that examines how gender has been referenced in United Nations (UN), supranational and state documents on forced migration over the past 40 years. It is motivated by the premise that humanitarian protection discourses reflect broader institutional priorities and ideologies and may therefore expose gaps that reveal the relative importance given to the category of gender. The evidence presented below is the result of an extensive review of policy documents on Afghanistan, Kurdistan Region-Iraq (KRI), and Sri Lanka contained in the Refworld database. 1 The study sought to understand how gender is mentioned in terms of 1.  governmentality — a top-down policy preference, which emphasizes the management of humanitarian protection; 2.  empowerment — a bottom up policy preference, which emphasizes self-actualization and self-determination: we seek to understand how agency is expressed, including how opportunities for participation feature in policy discourse; 3.  inclusion — the scope of coverage of different gender categories in policy discourse; and, 4.  differentiation — the particularization of needs, wishes, and demands made by women, men, and girls and boys in displacement settings. The paper finds: • Where gender and displacement are discussed together, there is greater emphasis on governmentality, which crowds out other objectives, including advancing opportunities for gender empowerment and participation. • Internally displaced persons (IDPs) tend to be treated as an operational challenge alongside security and peacebuilding. The nature of their displacement is implicit in these documents, associated within the recurring themes of land, violence, empowerment, and livelihoods. The documents mention violence, but do not widely cover maternal, sexual, and reproductive health. • The documents offer little insight into the identities of the displaced — whether female, male, children, or members of LGBT communities — and are mostly silent on their specific protection needs. Overall, the paper finds remarkably little integration of gender within the humanitarian literature on forced displacement. In spite of much advocacy by the UN, the concept of gender has not been effectively disaggregated to address the specific needs of IDPs, especially in the discussion of children. This paper argues that taking gender seriously means recognizing how protection needs may be shaped by power relationships, and how policy and practice would be enhanced by a more nuanced understanding of how vulnerabilities and opportunities are structured by gender and the specificities of the displacement context. It recommends that the United Nations High Commissioner for Refugees (UNHCR) and partner UN agencies continue to find opportunities to bring humanitarian policy on gender and forced displacement into conversation in order to strengthen protection. To this end, it suggests that the concept of gender should be disaggregated to address the specific needs of displaced people, to reflect the wider range of identities of displaced people, and to foster opportunities for their empowerment, and participation

Animal Blood supplemented diet can improve growth performance, body composition and blood profile of Genetically Improved Farm Tilapia (Oreochromis niloticus)

Background: Artificial feeding is an effective way to enhance fish production, development and carrying capacity of the culture system to feed the increasing human population. This study was designed to determine and compare the effects of supplementation of basal fish feed with plant (soybean meal) and animal blood as protein sources.Methods: The experiment was conducted using a completely randomized block design. A total of 135 Genetically Improved Farm Tilapia were randomly divided into three groups comprising three replicates and kept in controlled conditions in nine glass aquaria for a period of ninety days. The animals were provided basal diet, plant and animal protein supplemented diets throughout the experiment. Water quality parameters were recorded on a routine basis while growth performance, blood indices and chemical analysis of the body was recorded after ninety days of trial.Results: Overall, water quality parameters remained within the normal range, which highlights those diets had no detrimental effect on the quality of the water and in all groups. However, the fish kept on animal-based protein source diet presented higher growth performance, crude protein and lipids contents, red blood cell count and normal serum ALT, AST, and ALP levels In contrast the fish kept on plant protein diet displayed comparatively lower meat quality and signs of toxicity viz., raised level of hepatic enzymes.Conclusion: From these results, it was concluded that fish fed on diet having blood meal supplementation showed higher performance in comparison to fish groups fed on other diets.Keywords: GIFT; Fish feed; Plant meal; Soybean meal; Animal blood

Figurations of displacement in and beyond Pakistan: empirical findings and reflections on protracted displacement and translocal connections of Afghans

Pakistan currently hosts up to three million Afghans, a number that is likely to increase due to the Taliban's recent return to power in Afghanistan. This working paper is based on empirical research on the experience of Afghan displacement in Pakistan from 2019 until early 2021 as part of the European Union funded TRAFIG project. Findings show that Afghans' protracted displacement is classed. Many low-skilled, low-income and largely non-educated Afghans experience barriers to upward social mobility, particularly leading the Afghan youth to consider migrating to Europe. First-generation Afghan refugees who migrated mainly in the 1980s and 1990s prefer to stay in Pakistan; only few would return if the conditions allowed it. While aiming to incentivise return, Pakistani government policies hamper the opportunity for Afghans to move around within and beyond Pakistan and remain connected to their translocal and transnational networks. Many Afghan refugees have family members who live in other parts of Pakistan or in other countries, but the potential of these networks to lift those in Pakistan out of protracted displacement is limited. We also found that social cohesion between Afghan refugees and the Pakistani host society has been decreasing. Local networks are highly significant in day-to-day life, but intergroup relations do not yield any emancipatory potential for Afghans. Afghans' presence in Pakistan needs to be reconsidered by all actors, namely the country of origin, host and donor countries. The current approach of 'administering Afghans' keeps them in protracted displacement without the opportunity to integrate legally or sustainably. It needs to be replaced with a new narrative and operational approach - one that acknowledges Afghans' contributions to Pakistan's economy, society and culture, and that secures their right to remain in Pakistan. Such an approach is particularly important today given the looming prospect of more Afghans entering Pakistan to escape from living under a government headed by the Taliban

Antenatal Magnesium Sulfate for Preterm Neuroprotection: A Single-Center Experience from Kuwait Tertiary NICU

Objectives: The study aimed to evaluate the impact of antenatal exposure of magnesium sulfate (MgSO4) on short- and long-term outcomes in preterm neonates born less than 32 weeks gestation. Methods: Single-center retrospective cohort study of 229 neonates born between 24 and 32 weeks gestation was conducted from January 2018 through December 2018 in a level III neonatal care unit in Kuwait. Antenatal MgSO4 exposure was collected from the medical records, and the indication was for neuroprotection effect. Brain MRI was done on 212 neonates (median gestational age 36 weeks), and brain injury was assessed using the Miller’s score. Neurodevelopmental outcome was assessed by Bayley-III scales of infant development at 36 months corrected age (N = 146). The association of exposure to MgSO4 with brain injury and neurodevelopmental outcomes was examined using multivariable regression analysis adjusting for gestational age at MRI and variables with p value <0.05 on univariate analysis. Results: Among the 229 neonates, 47 received antenatal MgSO4. There were no differences between the groups in gestational age and birth weight. MgSO4 exposure was not associated with an increased risk of necrotizing enterocolitis, chronic lung disease, retinopathy of prematurity, and mortality. The incidence of cerebellar hemorrhage was significantly less in the MgSO4 group (0% vs. 16%, p value = 0.002). Neonates who received MgSO4 had lower risks of grade 3–4 intraventricular hemorrhage (IVH) adjusted OR 0.248 (95% CI: 0.092, 0.66), p = 0.006; moderate-severe white matter injury (WMI) adjusted odd ratio 0.208 (95% CI: 0.044, 0.96), p = 0.046; and grade 3–4 IVH and/or moderate-severe WMI adjusted OR 0.23 (95% CI: 0.06, 0.84), p = 0.027. Neurodevelopmental assessment at 36 months corrected age showed better motor (adjusted beta coefficient 1.08 [95% CI: 0.099, 2.06]; p = 0.031) and cognitive composite scores (adjusted beta coefficient 1.29 [95% CI: 0.36, 2.22]; p = 0.007) in the MgSO4 group. Conclusion: Antenatal exposure to MgSO4 in preterm neonates less than 32 weeks was independently associated with lower risks of brain injury and better motor and cognitive outcomes

Quantitative modelling of amino acid transport and homeostasis in mammalian cells

Homeostasis is one of the fundamental concepts in physiology. Despite remarkable progress in our molecular understanding of amino acid transport, metabolism and signaling, it remains unclear by what mechanisms cytosolic amino acid concentrations are maintained. We propose that amino acid transporters are the primary determinants of intracellular amino acid levels. We show that a cell’s endowment with amino acid transporters can be deconvoluted experimentally and used this data to computationally simulate amino acid translocation across the plasma membrane. Transport simulation generates cytosolic amino acid concentrations that are close to those observed in vitro. Perturbations of the system are replicated in silico and can be applied to systems where only transcriptomic data are available. This work explains amino acid homeostasis at the systems-level, through a combination of secondary active transporters, functionally acting as loaders, harmonizers and controller transporters to generate a stable equilibrium of all amino acid concentrations

Coordinated action of multiple transporters in the acquisition of essential cationic amino acids by the intracellular parasite Toxoplasma gondii

Intracellular parasites of the phylum Apicomplexa are dependent on the scavenging of essential amino acids from their hosts. We previously identified a large family of apicomplexan-specific plasma membrane-localized amino acid transporters, the ApiATs, and showed that the Toxoplasma gondii transporter TgApiAT1 functions in the selective uptake of arginine. TgApiAT1 is essential for parasite virulence, but dispensable for parasite growth in medium containing high concentrations of arginine, indicating the presence of at least one other arginine transporter. Here we identify TgApiAT6-1 as the second arginine transporter. Using a combination of parasite assays and heterologous characterisation of TgApiAT6-1 in Xenopus laevis oocytes, we demonstrate that TgApiAT6-1 is a general cationic amino acid transporter that mediates both the high-affinity uptake of lysine and the low-affinity uptake of arginine. TgApiAT6-1 is the primary lysine transporter in the disease-causing tachyzoite stage of T. gondii and is essential for parasite proliferation. We demonstrate that the uptake of cationic amino acids by TgApiAT6-1 is ‘trans-stimulated’ by cationic and neutral amino acids and is likely promoted by an inwardly negative membrane potential. These findings demonstrate that T. gondii has evolved overlapping transport mechanisms for the uptake of essential cationic amino acids, and we draw together our findings into a comprehensive model that highlights the finely-tuned, regulated processes that mediate cationic amino acid scavenging by these intracellular parasites.This work was supported by Discovery Grants from the Australian Research Council to KK, GGvD and SB (DP150102883) and to GGvD and KK (DP200100483). MJM is a NHMRC Principal Research Fellow (APP1154540). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Effect of early tranexamic acid administration on mortality, hysterectomy, and other morbidities in women with post-partum haemorrhage (WOMAN): an international, randomised, double-blind, placebo-controlled trial

Background Post-partum haemorrhage is the leading cause of maternal death worldwide. Early administration of tranexamic acid reduces deaths due to bleeding in trauma patients. We aimed to assess the effects of early administration of tranexamic acid on death, hysterectomy, and other relevant outcomes in women with post-partum haemorrhage. Methods In this randomised, double-blind, placebo-controlled trial, we recruited women aged 16 years and older with a clinical diagnosis of post-partum haemorrhage after a vaginal birth or caesarean section from 193 hospitals in 21 countries. We randomly assigned women to receive either 1 g intravenous tranexamic acid or matching placebo in addition to usual care. If bleeding continued after 30 min, or stopped and restarted within 24 h of the first dose, a second dose of 1 g of tranexamic acid or placebo could be given. Patients were assigned by selection of a numbered treatment pack from a box containing eight numbered packs that were identical apart from the pack number. Participants, care givers, and those assessing outcomes were masked to allocation. We originally planned to enrol 15 000 women with a composite primary endpoint of death from all-causes or hysterectomy within 42 days of giving birth. However, during the trial it became apparent that the decision to conduct a hysterectomy was often made at the same time as randomisation. Although tranexamic acid could influence the risk of death in these cases, it could not affect the risk of hysterectomy. We therefore increased the sample size from 15 000 to 20 000 women in order to estimate the effect of tranexamic acid on the risk of death from post-partum haemorrhage. All analyses were done on an intention-to-treat basis. This trial is registered with ISRCTN76912190 (Dec 8, 2008); ClinicalTrials.gov, number NCT00872469; and PACTR201007000192283. Findings Between March, 2010, and April, 2016, 20 060 women were enrolled and randomly assigned to receive tranexamic acid (n=10 051) or placebo (n=10 009), of whom 10 036 and 9985, respectively, were included in the analysis. Death due to bleeding was significantly reduced in women given tranexamic acid (155 [1·5%] of 10 036 patients vs 191 [1·9%] of 9985 in the placebo group, risk ratio [RR] 0·81, 95% CI 0·65–1·00; p=0·045), especially in women given treatment within 3 h of giving birth (89 [1·2%] in the tranexamic acid group vs 127 [1·7%] in the placebo group, RR 0·69, 95% CI 0·52–0·91; p=0·008). All other causes of death did not differ significantly by group. Hysterectomy was not reduced with tranexamic acid (358 [3·6%] patients in the tranexamic acid group vs 351 [3·5%] in the placebo group, RR 1·02, 95% CI 0·88–1·07; p=0·84). The composite primary endpoint of death from all causes or hysterectomy was not reduced with tranexamic acid (534 [5·3%] deaths or hysterectomies in the tranexamic acid group vs 546 [5·5%] in the placebo group, RR 0·97, 95% CI 0·87-1·09; p=0·65). Adverse events (including thromboembolic events) did not differ significantly in the tranexamic acid versus placebo group. Interpretation Tranexamic acid reduces death due to bleeding in women with post-partum haemorrhage with no adverse effects. When used as a treatment for postpartum haemorrhage, tranexamic acid should be given as soon as possible after bleeding onset. Funding London School of Hygiene & Tropical Medicine, Pfizer, UK Department of Health, Wellcome Trust, and Bill & Melinda Gates Foundation