Glucose-induced down regulation of thiamine transporters in the kidney proximal tubular epithelium produces thiamine insufficiency in diabetes

Increased renal clearance of thiamine (vitamin B1) occurs in experimental and clinical diabetes producing thiamine insufficiency mediated by impaired tubular re-uptake and linked to the development of diabetic nephropathy. We studied the mechanism of impaired renal re-uptake of thiamine in diabetes. Expression of thiamine transporter proteins THTR-1 and THTR-2 in normal human kidney sections examined by immunohistochemistry showed intense polarised staining of the apical, luminal membranes in proximal tubules for THTR-1 and THTR-2 of the cortex and uniform, diffuse staining throughout cells of the collecting duct for THTR-1 and THTR-2 of the medulla. Human primary proximal tubule epithelial cells were incubated with low and high glucose concentration, 5 and 26 mmol/l, respectively. In high glucose concentration there was decreased expression of THTR-1 and THTR-2 (transporter mRNA: −76% and −53% respectively, p<0.001; transporter protein −77% and −83% respectively, p<0.05), concomitant with decreased expression of transcription factor specificity protein-1. High glucose concentration also produced a 37% decrease in apical to basolateral transport of thiamine transport across cell monolayers. Intensification of glycemic control corrected increased fractional excretion of thiamine in experimental diabetes. We conclude that glucose-induced decreased expression of thiamine transporters in the tubular epithelium may mediate renal mishandling of thiamine in diabetes. This is a novel mechanism of thiamine insufficiency linked to diabetic nephropathy

Recent advances on information transmission and storage assisted by noise

The interplay between nonlinear dynamic systems and noise has proved to be of great relevance in several application areas. In this presentation, we focus on the areas of information transmission and storage. We review some recent results on information transmission through nonlinear channels assisted by noise. We also present recent proposals of memory devices in which noise plays an essential role. Finally, we discuss new results on the influence of noise in memristors.Comment: To be published in "Theory and Applications of Nonlinear Dynamics: Model and Design of Complex Systems", Proceedings of ICAND 2012 (Springer, 2014

Theorising Māori Health and Wellbeing in a Whakapapa Paradigm: Voices from the Margins

Whakapapa is an Indigenous metatheoretical framework; a phenomenon of metaphysical and social connections embedded in Indigenous epistemology unique to Aotearoa New Zealand (Aotearoa NZ). This research foregrounds the innate connection between Māori, land, health, and wellbeing as an expression of Whakapapa, nuanced through the layering of lived experience and sensemaking of 30 Māori participants, situated in dialogue with the culture-centered approach (CCA). Noting the erasure of Māori voices from the hegemonic frame of health communication in the settler colonial state, we sought to understand health and wellbeing meanings, challenges and solutions as articulated by Māori participants at the margins of Indigeneity. Drawing on the CCA approach to health communication, the manuscript highlights the relationship between Whakapapa and voice. The dialogs emergent from in-depth interviews place the CCA in dialogue with the Whakapapa paradigm, foregrounding the role of voice democracy in creating anchors to health and wellbeing among Māori, rooted in tino rangatiratanga (sovereignty). The articulations of Māori health voiced from/at the margins are offered as interventions into the large-scale health inequities experienced by Māori in Aotearoa NZ.fals

The United Nations (UN) Card, Identity, and Negotiations of Health among Rohingya Refugees

Being persecuted and expelled from Myanmar, Rohingya refugees are now distributed throughout the world. The Southeast Asian nation of Malaysia has been a preferred destination for Rohingyas fleeing Myanmar's state-sponsored genocide and more recently in a bid to change their fates from the refugee camps in Bangladesh. Refugees are one of the most vulnerable groups in Malaysia and often face dire circumstances, in which their health and wellbeing are compromised. Amidst a plethora of structural challenges, Rohingya refugees try to claim some of their rights with the aid of the UN card (UNHCR ID cards) in Malaysia. Guided by the culture-centered approach (CCA), this study examined the perspectives and experiences of healthcare among Rohingya refugees while living in Malaysia, now resettled in Aotearoa, New Zealand. The participants' narratives showed that the UN card not only materialized their refugee status in Malaysia but also offered them a way of living in a world where documents anchor the materiality of health.fals

Situating Health Experiences: A Culture-Centered Interrogation

Culture-centered studies of health communication de-center the theorization of health as an individual behavior and reveal the structural conditions that shape inequalities in health outcomes. The present study examines the ways in which space and housing shape experiences of health in a low-income site in Auckland undergoing radical redevelopment. We draw from a culture-centered project undertaken in 2018-2021 predominantly among Māori and Pasifika peoples involving 60 initial in-depth interviews, seven focus groups, a series of filmed interviews, and 32 additional in-depth interviews conducted during the COVID-19 pandemic. The residents' narratives foregrounded the detrimental health impact of inadequate housing, financial constraints, transience, and displacement that severs ties to place and community. These findings reveal the relationship between housing challenges, economic marginalization, and neoliberal capitalism, highlighting the need for policy interventions to address housing as a fundamental determinant of health disparities among marginalized communities.fals

Structural analysis and corrosion studies on an ISO 5832-9 biomedical alloy with TiO2 sol–gel layers

The aim of this study was to demonstrate the relationship between the structural and corrosion properties of an ISO 5832-9 biomedical alloy modified with titanium dioxide (TiO2) layers. These layers were obtained via the sol–gel method by acid-catalyzed hydrolysis of titanium isopropoxide in isopropanol solution. To obtain TiO2 layers with different structural properties, the coated samples were annealed at temperatures of 200, 300, 400, 450, 500, 600 and 800 C for 2 h. For all the prepared samples, accelerated corrosion measurements were performed in Tyrode’s physiological solution using electrochemical methods. The most important corrosion parameters were determined: corrosion potential, polarization resistance, corrosion rate, breakdown and repassivation potentials. Corrosion damage was analyzed using scanning electron microscopy. Structural analysis was carried out for selected TiO2 coatings annealed at 200, 400, 600 and 800 C. In addition, the morphology, chemical composition, crystallinity, thickness and density of the deposited TiO2 layers were determined using suitable electron and X-ray measurement methods. It was shown that the structure and character of interactions between substrate and deposited TiO2 layers depended on annealing temperature. All the obtained TiO2 coatings exhibit anticorrosion properties, but these properties are related to the crystalline structure and character of substrate–layer interaction. From the point of view of corrosion, the best TiO2 sol–gel coatings for stainless steel intended for biomedical applications seem to be those obtained at 400 C.This study was supported by Grant No. N N507 501339 of the National Science Centre. The authors wish to express their thanks to J. Borowski (MEDGAL, Poland) for the Rex 734 alloy

Canine respiratory coronavirus employs caveolin-1-mediated pathway for internalization to HRT-18G cells

Canine respiratory coronavirus (CRCoV), identified in 2003, is a member of the Coronaviridae family. The virus is a betacoronavirus and a close relative of human coronavirus OC43 and bovine coronavirus. Here, we examined entry of CRCoV into human rectal tumor cells (HRT-18G cell line) by analyzing co-localization of single virus particles with cellular markers in the presence or absence of chemical inhibitors of pathways potentially involved in virus entry. We also targeted these pathways using siRNA. The results show that the virus hijacks caveolin-dependent endocytosis to enter cells via endocytic internalization

Control of intestinal stem cell function and proliferation by mitochondrial pyruvate metabolism.

Most differentiated cells convert glucose to pyruvate in the cytosol through glycolysis, followed by pyruvate oxidation in the mitochondria. These processes are linked by the mitochondrial pyruvate carrier (MPC), which is required for efficient mitochondrial pyruvate uptake. In contrast, proliferative cells, including many cancer and stem cells, perform glycolysis robustly but limit fractional mitochondrial pyruvate oxidation. We sought to understand the role this transition from glycolysis to pyruvate oxidation plays in stem cell maintenance and differentiation. Loss of the MPC in Lgr5-EGFP-positive stem cells, or treatment of intestinal organoids with an MPC inhibitor, increases proliferation and expands the stem cell compartment. Similarly, genetic deletion of the MPC in Drosophila intestinal stem cells also increases proliferation, whereas MPC overexpression suppresses stem cell proliferation. These data demonstrate that limiting mitochondrial pyruvate metabolism is necessary and sufficient to maintain the proliferation of intestinal stem cells

COVID-19, Authoritarian Neoliberalism, and Precarious Migrant Work in Singapore: Structural Violence and Communicative Inequality

Drawing upon an ongoing ethnography with low-wage migrant workers in Singapore, this article builds on the theoretical framework of the culture-centered approach (CCA) to explore the experiences of the workers amid COVID-19 outbreaks in dormitories housing them. The CCA foregrounds the interplays of communicative and material inequalities, suggesting that the erasure of infrastructures of voices among the margins reproduces and circulates unhealthy structures that threaten the health and well-being of the working classes. The voices of the low-wage migrant workers who participated in this study document the challenges with poor housing, poor sanitation, and food insecurity that are compounded with the absence of information and voice infrastructures. Amid the everyday threats to health and well-being that are generated by neoliberal reforms across the globe, the hyper-precarious conditions of migrant work rendered visible by the trajectories of COVID-19 call for structurally transformative futures that are anchored in the voices of workers at the margins of neoliberal economies.fals

Resisting an unfolding genocide: reflections from radical struggles in the Global South

This essay theorizes radical struggles at the world’s end, emergent from registers of organizing against colonial–imperial–capitalist violence in the Global South. Working through the ongoing genocidal violence carried out by Israel in Gaza, I explore the role of voice infrastructures in the Global South as the spaces where Global South theories are imagined, tested, and continually transformed. The tenets of the culture-centered approach (CCA), reflected in the everyday organizing work of the Center for Culture-centered Approach to Research and Evaluation (CARE), guide the conceptualization of the relationship between theorizing and struggle as embodied practice. For radical organizing to materialize at the world’s end, I argue the urgency of reorganizing the relationship between struggles and theorizing, cultivating a rhetoric and politics of suspicion, enacting sovereignty, forging connections, and sustaining a politics of preparation.fals