The Changing Landscape of Race, Culture, and Family Life: Interracial Couples' Contribution to the Conversation

The published social science research on interracial marriages has burgeoned considerably over the past few decades as experts address not only traditional, but also emerging questions about the quality of life in mixed-race families. The "emic" experience of being in a mixed race family remains, though, a relatively under-explored topic. To help fill the gap, we conducted a nationally distributed, snowball sample, anonymous, online survey of 241 married or cohabiting individuals; 83.6% self-identified as a member of a bi-racial couple. The 131 items surveyed couples' experiences of their partnership, family life, support, and discrimination—both in time and in place. The study presented multiple findings including a persistence of race discrimination in neighborhoods and at work; surprisingly, the couples also reported that their children were allowed to play with the children of White neighbors, regardless of the racial makeup of the family. There was a significant relationship between "importance of falling in love" and the racial makeup of the couple (x2 (15, N=205) =30.42, p=.01); Black/White and Hispanic/White couples choose their partner for love. Moreover, same race couples expressed the most unhappiness and the most regret of all of the couple-groups surveyed. Most concerning, though, was that interracial couples perceive raising multiracial children as more difficult; these results were significant (x2 (30, N=206) =62.68, p=.00) with Black/White couples, at 45.7%. The study presents multiple correlation tables. Additionally, limitations of the study are discussed and suggestions for further studies are presented

Critical role of mTOR, PPARγ and PPARδ signaling in regulating early pregnancy decidual function, embryo viability and feto-placental growth

STUDY QUESTION: What are the consequences of inhibiting mTOR, the mechanistic target of rapamycin (mTOR), and the peroxisome proliferator activated receptor gamma (PPARγ) and PPARδ pathways in the early post-implantation period on decidual function, embryo viability and feto-placental growth in the ratγ SUMMARY ANSWER: mTOR inhibition from Days 7 to 9 of pregnancy in rats caused decidual PPARγ and PPARδ upregulation on Day 9 of pregnancy and resulted in embryo resorption by Day 14 of pregnancy. PPARγ and PPARδ inhibition differentially affected decidual mTOR signaling and levels of target proteins relevant to lipid histotrophic nutrition and led to reduced feto-placental weights on Day 14 of pregnancy. WHAT IS KNOWN ALREADY: Although mTOR, PPARγ and PPARδ are nutrient sensors important during implantation, the role of these signaling pathways in decidual function and how they interact in the early post-implantation period are unknown. Perilipin 2 (PLIN2) and fatty acid binding protein 4 (FABP4), two adipogenic proteins involved in lipid histotrophic nutrition, are targets of mTOR and PPAR signaling pathways in a variety of tissues. STUDY DESIGN, SIZE, DURATION: Rapamycin (mTOR inhibitor, 0.75 mg/kg, sc), T0070907 (PPARγ inhibitor, 0.001 mg/kg, sc), GSK0660 (PPARδ inhibitor, 0.1 mg/kg, sc) or vehicle was injected daily to pregnant rats from Days 7 to 9 of pregnancy and the studies were performed on Day 9 of pregnancy (n = 7 per group) or Day 14 of pregnancy (n = 7 per group). PARTICIPANTS/MATERIALS, SETTING, METHODS: On Day 9 of pregnancy, rat decidua were collected and prepared for western blot and immunohistochemical studies. On Day 14 of pregnancy, the resorption rate, number of viable fetuses, crown-rump length and placental and decidual weights were determined. MAIN RESULTS AND THE ROLE OF CHANCE: Inhibition of mTOR in the early post-implantation period led to a reduction in FABP4 protein levels, an increase in PLIN2 levels and an upregulation of PPARγ and PPARδ in 9-day-pregnant rat decidua. Most embryos were viable on Day 9 of pregnancy but had resorbed by Day 14 of pregnancy. This denotes a key function of mTOR in the post-implantation period and suggests that activation of PPAR signaling was insufficient to compensate for impaired nutritional/survival signaling induced by mTOR inhibition. Inhibition of PPARγ signaling resulted in decreased decidual PLIN2 and FABP4 protein expression as well as in inhibition of decidual mTOR signaling in Day 9 of pregnancy. This treatment also reduced feto-placental growth on Day 14 of pregnancy, revealing the relevance of PPARγ signaling in sustaining post-implantation growth. Moreover, following inhibition of PPARδ, PLIN2 levels were decreased and mTOR complex 1 and 2 signaling was altered in decidua on Day 9 of pregnancy. On Day 14 of pregnancy, PPARδ inhibition caused reduced fetoplacental weight, increased decidual weight and increased resorption rate, suggesting a key role of PPARδ in sustaining post-implantation development. LARGE SCALE DATA: Not applicable. LIMITATIONS, REASONS FOR CAUTION: This is an in vivo animal study and the relevance of the results for humans remains to be established. WIDER IMPLICATIONS OF THE FINDINGS: The early post-implantation period is a critical window of development and changes in the intrauterine environment may cause embryo resorption and lead to placental and fetal growth restriction. mTOR, PPARγ and PPARδ signaling are decidual nutrient sensors with extensive cross-talk that regulates adipogenic proteins involved in histotrophic nutrition and important for embryo viability and early placental and fetal development and growth. STUDY FUNDING/COMPETING INTEREST(S): Funding was provided by the Agencia Nacional de Promoción Científica y Tecnológica de Argentina (PICT 2014-411 and PICT 2015-0130), and by the International Cooperation (Grants CONICET-NIH-2014 and CONICETNIH- 2017) to A.J. and T.J. The authors have no conflicts of interest.Fil: Roberti, Sabrina Lorena. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios Farmacológicos y Botánicos; ArgentinaFil: Higa, Romina Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios Farmacológicos y Botánicos; ArgentinaFil: White, Verónica. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios Farmacológicos y Botánicos; ArgentinaFil: Powell, Theresa L.. State University of Colorado at Boulder; Estados UnidosFil: Jansson, Thomas. State University of Colorado at Boulder; Estados UnidosFil: Jawerbaum, Alicia Sandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios Farmacológicos y Botánicos; Argentin

ZnII(atsm) is protective in amyotrophic lateral sclerosis model mice via a copper delivery mechanism

AbstractMutations in the metalloprotein Cu,Zn-superoxide dismutase (SOD1) cause approximately 20% of familial cases of amyotrophic lateral sclerosis (ALS), a fatal neurodegenerative disease for which effective therapeutics do not yet exist. Transgenic rodent models based on over-expression of mutant SOD1 have been developed and these have provided opportunity to test new therapeutic strategies and to study the mechanisms of mutant SOD1 toxicity. Although the mechanisms of mutant SOD1 toxicity are yet to be fully elucidated, incorrect or incomplete metallation of SOD1 confers abnormal folding, aggregation and biochemical properties, and improving the metallation state of SOD1 provides a viable therapeutic option. The therapeutic effects of delivering copper (Cu) to mutant SOD1 have been demonstrated recently. The aim of the current study was to determine if delivery of zinc (Zn) to SOD1 was also therapeutic. To investigate this, SOD1G37R mice were treated with the metal complex diacetyl-bis(4-methylthiosemicarbazonato)zincII [ZnII(atsm)]. Treatment resulted in an improvement in locomotor function and survival of the mice. However, biochemical analysis of spinal cord tissue collected from the mice revealed that the treatment did not increase overall Zn levels in the spinal cord nor the Zn content of SOD1. In contrast, overall levels of Cu in the spinal cord were elevated in the ZnII(atsm)-treated SOD1G37R mice and the Cu content of SOD1 was also elevated. Further experiments demonstrated transmetallation of ZnII(atsm) in the presence of Cu to form the Cu-analogue CuII(atsm), indicating that the observed therapeutic effects for ZnII(atsm) in SOD1G37R mice may in fact be due to in vivo transmetallation and subsequent delivery of Cu

Macrophage phenotype in response to ECM bioscaffolds

Macrophage presence and phenotype are critical determinants of the healing response following injury. Downregulation of the pro-inflammatory macrophage phenotype has been associated with the therapeutic use of bioscaffolds composed of extracellular matrix (ECM), but phenotypic characterization of macrophages has typically been limited to small number of non-specific cell surface markers or expressed proteins. The present study determined the response of both primary murine bone marrow derived macrophages (BMDM) and a transformed human mononuclear cell line (THP-1 cells) to degradation products of two different, commonly used ECM bioscaffolds; urinary bladder matrix (UBM-ECM) and small intestinal submucosa (SIS-ECM). Quantified cell responses included gene expression, protein expression, commonly used cell surface markers, and functional assays. Results showed that the phenotype elicited by ECM exposure (MECM) is distinct from both the classically activated IFNγ + LPS phenotype and the alternatively activated IL-4 phenotype. Furthermore, the BMDM and THP-1 macrophages responded differently to identical stimuli, and UBM-ECM and SIS-ECM bioscaffolds induced similar, yet distinct phenotypic profiles. The results of this study not only characterized an MECM phenotype that has anti-inflammatory traits but also showed the risks and challenges of making conclusions about the role of macrophage mediated events without consideration of the source of macrophages and the limitations of individual cell markers

Does in utero HIV exposure and the early nutritional environment influence infant development and immune outcomes? Findings from a pilot study in Pretoria, South Africa

BACKGROUND : As mother-to-child transmission of HIV decreases, and the population of infants who are born HIV-exposed, but uninfected (HEU) continues to rise, there is a growing need to understand the development and health outcomes of infants who are HEU to ensure that they have the healthiest start to life. METHODS : In a prospective cohort pilot study at Kalafong Hospital, Pretoria, South Africa, we aimed to determine if we could recruit new mothers living with HIV on antiretrovirals (ART; n = 20) and not on ART (n = 20) and new mothers without HIV (n = 20) through our clinics to study the effects of HEU on growth and immune- and neurodevelopment in infants in early life, and test the hypothesis that infants who were HEU would have poorer health outcomes compared to infants who were HIV-unexposed, uninfected (HUU). We also undertook exploratory analyses to investigate relationships between the early nutritional environment, food insecurity and infant development. Infant growth, neurodevelopment (Guide for Monitoring Child Development [GMCD]) and levels of monocyte subsets (CD14, CD16 and CCR2 expression [flow cytometry]) were measured in infants at birth and 12 weeks (range 8–16 weeks). RESULTS : We recruited 33 women living with HIV on ART and 22 women living without HIV within 4 days of delivery from June to December 2016. Twenty-one women living with HIV and 10 without HIV returned for a follow-up appointment at 12 weeks postpartum. The high mobility of this population presented major challenges to participant retention. Preliminary analyses revealed lower head circumference and elevated CCR2+ (% and median fluorescence intensity) on monocytes at birth among infants who were HEU compared to HUU. Maternal reports of food insecurity were associated with lower maternal nutrient intakes at 12 weeks postpartum and increased risk of stunting at birth for infants who were HEU, but not infants who were HUU. CONCLUSIONS : Our small feasibility pilot study suggests that HEU may adversely affect infant development, and further, infants who are HEU may be even more vulnerable to the programming effects of suboptimal nutrition in utero and postnatally. This pilot and preliminary analyses have been used to inform our research questions and protocol in our ongoing, full-scale study.Additional file 1: Supplementary Figure S1. Sequential gating approach for the measurement of CCR2 expression by CD14+ monocytes. The sequential gating approached used was as follows: First, the viable (7-AAD negative; region ‘Viable”) cells were identified using a 7-AAD vs SS Log density plot. A “Viable” region was created around the 7-AAD negative cells. Gated on the “Viable”cells, a SSLog vs FS plot was used to capture intact cells in the “E” region. CD14+ monocytes were identified (“CD14+” region) using a CD14 vs SS Log density plot that were gated on viable, intact cells (“E” region). CD14+ monocytes that express CCR2 were quantified using a CD192 (CCR2) vs SS Log plot. The proportion of CD14+/CCR2+ cells were captured in the “CD14+ CCR2+” region. The gating strategy followed to quantify CCR2 expression by CD16+ neutrophils was similar to what was described for CD14+ monocytes, but instead of identifying CD14+ monocytes, CD16+ neutrophils were identified (“CD16+” region) using a CD16 vs SS Log density plot that were gated on viable, intact cells (“E” region). CD16+ neutrophils that express CCR2 were quantified using a CD192 (CCR2) vs SS Log plot. The proportion of CD14+/CCR2+ cells was captured in the “CD16+ CCR2+” region.Additional file 2: Supplementary Figure S2. Sequential gating approach for the measurement of CCR2 expression by monocyte subpopulations. Doublets and debris were removed (Region ‘K’) using a FS Area vs FS Height density plot. A 7-AAD vs SS Log density plot, gated on ‘K’ was used to exclude all non-viable cells. Viable cells were captured in region ‘Viable’. Viable CD14+ monocytes were identified (Region ‘CD14+ Monocytes’) using a CD14 APC vs SS Log density plot. Monocyte sub-populations were identified using a CD16 FITC vs CD14 PE density plot gated on viable, CD14+ monocytes. Four monocyte sub-populations were identified: CD14+/CD16-; CD14++/CD16-; CD14+/CD16+; and CD14++/CD16+. The percentage CCR2+ monocytes present in each of the respective monocyte sub-populations were identified using CD195 (CCR2) PE vs SS Log two-parameter plots gated on the respective subpopulations. The overlay plots within the black bordered square indicates the strategy used to determine CCR2 expression of the different monocyte subsets. The negative/positive staining boundaries were determined based on the negative expression of CCR2 by CD16++/CD14- neutrophils (indicated in red in the overlay plots). The CCR2+ populations are indicated in blue.Additional file 3: Supplementary Figure S3. Maternal intake of estimated average requirements for macronutrients, vitamins and minerals for mothers who report on household food security circumstances. Maternal reports of food insecurity did not associate with intake levels of macronutrients or minerals. Maternal reports of experiencing food runout or inability to afford balanced meals associated with lower intake of vitamin B12 (p=0.01; p=0.04). Many women, irrespective of food security reports, are at risk of inadequate macronutrient, vitamin and mineral intakes. Percent intake of EARs for 36 nutrients were calculated for lactating women 14-18, 19-30 or 31-50 years of age [37]. Calculations for EAR for total protein considered maternal weight at time of dietary recall. Data are % intake of EAR reported in maternal dietary recall for macronutrients, *p<0.05 [ANOVA for normal distribution/ equal variance; Kruskal-Wallis/Wilcoxon test for nonparametric data; or Welch’s test for normal data/unequal variance]). CHO = carbohydrates.Additional file 4: Supplementary Figure S4. Cooccurrence of maternal HIV and food insecurity may increase risk of stunting at birth. Amongst infants whose mothers report worrying about food runout, risk of stunting at birth is greater for HEU compared to HUU infants (e; RR=4.90 [0.76, 31.5], ARD=0.56 [0.17, 0.94], p=0.0498). The red line represents the proportion of infants who had stunting at birth or 12 weeks PP. Mosaic plots are proportion (%) of HUU or HEU infants who have stunting (<-2 SD length-for-age standardised according to WHO child growth standards [28]) at birth and 12 weeks old. HUU = HIV-unexposed, uninfected infant; HEU = HIV-exposed, uninfected infant. RR = Relative risk. ARD = Absolute risk difference.Additional file 5: Supplementary Figure S5. Food insecurity may associate with low attainment of GMCD milestones for HUU and HEU infants. Infants whose mothers reported household food insecurity did not attain 1-3 month GMCD milestones (A, C, E) for receptive language, large movement, relating and response behaviour or play activities, or 3-5 month GMCD milestones (B, D, F) for fine movement or relating and response behaviour in the same proportion as the international standardization sample. Maternal reports of food insecurity did not associate with risk of not attaining all 1-3 month or 3-5 month GMCD milestones (A-F, [p>0.05], Fisher’s exact 2-Tail). Data are proportion (%) of infants who attained all age-appropriate GMCD milestones. The horizontal dotted line represents the GMCD standardised international sample proportion (85%) of infants who attained all milestones in that age category, when they were in that age range. The numbers underneath the bars represent the number of infants attaining all milestones for each milestone. GMCD = Guide for monitoring child development; HUU = HIVunexposed, uninfected infant; HEU = HIVexposed, uninfected infant.Additional file 6: Supplementary Table S1. Flow cytometry reagent list (including lasers and detectors used). Supplementary Table S2. Flow cytometry compensation matrix. Supplementary Table S3. Maternal nutrient intakes from one 24-hour dietary recall for mothers with and without HIV who attended follow up. Supplementary Table S4. Maternal nutrient intake from one 24-hour dietary recall for mothers who report experiencing food insecurity compared to those who do not experience food insecurity.The Collaborative Initiative for Paediatric HIV Education and Research (CIPHER); the Faculty of Science, Carleton University; the Canadian Institutes of Health Research (CIHR); a Canadian Graduate Scholarship-Master’s and a Michael Smith Foreign Study Supplement from CIHR.https://pilotfeasibilitystudies.biomedcentral.comam2021ImmunologyObstetrics and GynaecologyPaediatrics and Child Healt

Providing comprehensive and consistent access to astronomical observatory archive data: the NASA archive model

Since the turn of the millennium a constant concern of astronomical archives have begun providing data to the public through standardized protocols unifying data from disparate physical sources and wavebands across the electromagnetic spectrum into an astronomical virtual observatory (VO). In October 2014, NASA began support for the NASA Astronomical Virtual Observatories (NAVO) program to coordinate the efforts of NASA astronomy archives in providing data to users through implementation of protocols agreed within the International Virtual Observatory Alliance (IVOA). A major goal of the NAVO collaboration has been to step back from a piecemeal implementation of IVOA standards and define what the appropriate presence for the US and NASA astronomy archives in the VO should be. This includes evaluating what optional capabilities in the standards need to be supported, the specific versions of standards that should be used, and returning feedback to the IVOA, to support modifications as needed. We discuss a standard archive model developed by the NAVO for data archive presence in the virtual observatory built upon a consistent framework of standards defined by the IVOA. Our standard model provides for discovery of resources through the VO registries, access to observation and object data, downloads of image and spectral data and general access to archival datasets. It defines specific protocol versions, minimum capabilities, and all dependencies. The model will evolve as the capabilities of the virtual observatory and needs of the community change

Tracking smell loss to identify healthcare workers with SARS-CoV-2 infection

Introduction Healthcare workers (HCW) treating COVID-19 patients are at high risk for infection and may also spread infection through their contact with vulnerable patients. Smell loss has been associated with SARS-CoV-2 infection, but it is unknown whether monitoring for smell loss can be used to identify asymptomatic infection among high risk individuals. In this study we sought to determine if tracking smell sensitivity and loss using an at-home assessment could identify SARS-CoV-2 infection in HCW. Methods and findings We performed a prospective cohort study tracking 473 HCW across three months to determine if smell loss could predict SARS-CoV-2 infection in this high-risk group. HCW subjects completed a longitudinal, behavioral at-home assessment of olfaction with household items, as well as detailed symptom surveys that included a parosmia screening questionnaire, and real-time quantitative polymerase chain reaction testing to identify SARS-CoV-2 infection. Our main measures were the prevalence of smell loss in SARS-CoV-2-positive HCW versus SARS-CoV- 2-negative HCW, and timing of smell loss relative to SARS-CoV-2 test positivity. SARS-CoV-2 was identified in 17 (3.6%) of 473 HCW. HCW with SARS-CoV-2 infection were more likely to report smell loss than SARS-CoV-2-negative HCW on both the at-home assessment and the screening questionnaire (9/17, 53% vs 105/456, 23%, P < .01). 6/9 (67%) of SARS-CoV-2-positive HCW reporting smell loss reported smell loss prior to having a positive SARS-CoV-2 test, and smell loss was reported a median of two days before testing positive. Neurological symptoms were reported more frequently among SARS-CoV-2-positive HCW who reported smell loss compared to those without smell loss (9/9, 100% vs 3/8, 38%, P < .01). Conclusions In this prospective study of HCW, self-reported changes in smell using two different measures were predictive of SARS-CoV-2 infection. Smell loss frequently preceded a positive test and was associated with neurological symptoms

SRT1720 improves survival and healthspan of obese mice

Sirt1 is an NAD+-dependent deacetylase that extends lifespan in lower organisms and improves metabolism and delays the onset of age-related diseases in mammals. Here we show that SRT1720, a synthetic compound that was identified for its ability to activate Sirt1 in vitro, extends both mean and maximum lifespan of adult mice fed a high-fat diet. This lifespan extension is accompanied by health benefits including reduced liver steatosis, increased insulin sensitivity, enhanced locomotor activity and normalization of gene expression profiles and markers of inflammation and apoptosis, all in the absence of any observable toxicity. Using a conditional SIRT1 knockout mouse and specific gene knockdowns we show SRT1720 affects mitochondrial respiration in a Sirt1- and PGC-1α-dependent manner. These findings indicate that SRT1720 has long-term benefits and demonstrate for the first time the feasibility of designing novel molecules that are safe and effective in promoting longevity and preventing multiple age-related diseases in mammals

Public Acceptability in the UK and USA of Nudging to Reduce Obesity: The Example of Reducing Sugar-Sweetened Beverages Consumption.

BACKGROUND: "Nudging"-modifying environments to change people's behavior, often without their conscious awareness-can improve health, but public acceptability of nudging is largely unknown. METHODS: We compared acceptability, in the United Kingdom (UK) and the United States of America (USA), of government interventions to reduce consumption of sugar-sweetened beverages. Three nudge interventions were assessed: i. reducing portion Size, ii. changing the Shape of the drink containers, iii. changing their shelf Location; alongside two traditional interventions: iv. Taxation and v. Education. We also tested the hypothesis that describing interventions as working through non-conscious processes decreases their acceptability. Predictors of acceptability, including perceived intervention effectiveness, were also assessed. Participants (n = 1093 UK and n = 1082 USA) received a description of each of the five interventions which varied, by randomisation, in how the interventions were said to affect behaviour: (a) via conscious processes; (b) via non-conscious processes; or (c) no process stated. Acceptability was derived from responses to three items. RESULTS: Levels of acceptability for four of the five interventions did not differ significantly between the UK and US samples; reducing portion size was less accepted by the US sample. Within each country, Education was rated as most acceptable and Taxation the least, with the three nudge-type interventions rated between these. There was no evidence to support the study hypothesis: i.e. stating that interventions worked via non-conscious processes did not decrease their acceptability in either the UK or US samples. Perceived effectiveness was the strongest predictor of acceptability for all interventions across the two samples. CONCLUSION: In conclusion, nudge interventions to reduce consumption of sugar-sweetened beverages seem similarly acceptable in the UK and USA, being more acceptable than taxation, but less acceptable than education. Contrary to prediction, we found no evidence that highlighting the non-conscious processes by which nudge interventions may work decreases their acceptability. However, highlighting the effectiveness of all interventions has the potential to increase their acceptability.The study was funded by the UK Department of Health Policy Research Programme (Policy Research Unit in Behaviour and Health) (Grant ID: PRUN-0409-10109)This is the final version of the article. It first appeared from the Public Library of Science via http://dx.doi.org/10.1371/journal.pone.015599

Erythrocyte Transketolase Activity, Markers of Cardiac Dysfunction and the Diagnosis of Infantile Beriberi

Infantile beriberi, or clinical thiamin (vitamin B1) deficiency in infants, is a forgotten disease in Asia, where ∼100 years ago it was a major public health problem. Children aged ∼2–3 months present in cardiac failure but usually rapidly improve if given thiamin injections. It remains relatively common in Vientiane, Lao PDR (Laos) probably because of prolonged intra- and post-partum maternal food avoidance behaviours. There has been very little recent research on the best diagnostic techniques. We conducted a case control study of 47 infants with beriberi and age-matched afebrile and febrile controls in Vientiane. The conventional measures of thiamin deficiency, basal and activated erythrocyte transketolase activities (ETK) and activation (α) coefficients, were assayed along with three markers of cardiac dysfunction - plasma brain natriuretic peptide, N-terminal pro-brain natriuretic peptide, and troponin T. Basal ETK was a better biochemical marker of infantile beriberi than the activation coefficient. Raised plasma troponin T may be a useful indicator of infantile beriberi in babies at risk and in the absence of other evident causes