A Randomized Trial of the IMPACT of Ferric Citrate on Erythropoietin and Intravenous Iron Use in Patients Receiving Dialysis.

INTRODUCTION: Ferric citrate (FC) is an FDA-approved iron-based phosphate binder for adults with dialysis-dependent chronic kidney disease. This study investigated the impact of FC as the primary phosphate-lowering therapy on utilization of erythropoiesis-stimulating agents (ESAs) and intravenous (IV) iron. METHODS: In this randomized, open-label, active-controlled, multicenter study (NCT04922645), patients on dialysis and receiving ESAs were randomized to receive FC or remain on standard of care (SOC) phosphate-lowering therapy for up to 6 months. Primary endpoints were the difference in change from baseline to efficacy evaluation period (EEP) in mean monthly ESA and IV iron doses. Secondary endpoints included treatment differences in hemoglobin, phosphate, TSAT, and ferritin levels. RESULTS: 209 patients were randomized to FC and had a Day 1 Dosing Visit (n=103) or SOC (n=106). The two groups had similar baseline laboratory characteristics, however atherosclerotic CV disease, peripheral vascular disease, and congestive heart failure were more common in the SOC group. The mean treatment difference in ESA monthly dose was -30.8 µg (FC vs SOC; p=0.02). An absolute though non-statistically significant change in mean monthly IV iron dose of -37.2 mg (p=0.17) was observed with FC. Mean hemoglobin, TSAT, and ferritin all increased from baseline to the EEP with FC vs. SOC. Serious adverse events occurred in 28% of patients receiving FC vs. 37% in those receiving SOC. CONCLUSIONS: In patients receiving dialysis, treatment with FC as compared to remaining on SOC phosphate binders resulted in reductions in mean monthly ESA and IV iron dose.

Neurocognitive outcome and mental health in children with tyrosinemia type 1 and phenylketonuria: A comparison between two genetic disorders affecting the same metabolic pathway.

Tyrosinemia type 1 (TT1) and phenylketonuria (PKU) are both inborn errors of phenylalanine-tyrosine metabolism. Neurocognitive and behavioral outcomes have always featured in PKU research but received less attention in TT1 research. This study aimed to investigate and compare neurocognitive, behavioral, and social outcomes of treated TT1 and PKU patients. We included 33 TT1 patients (mean age 11.24 years; 16 male), 31 PKU patients (mean age 10.84; 14 male), and 58 age- and gender-matched healthy controls (mean age 10.82 years; 29 male). IQ (Wechsler-subtests), executive functioning (the Behavioral Rating Inventory of Executive Functioning), mental health (the Achenbach-scales), and social functioning (the Social Skills Rating System) were assessed. Results of TT1 patients, PKU patients, and healthy controls were compared using Kruskal-Wallis tests with post-hoc Mann-Whitney U tests. TT1 patients showed a lower IQ and poorer executive functioning, mental health, and social functioning compared to healthy controls and PKU patients. PKU patients did not differ from healthy controls regarding these outcome measures. Relatively poor outcomes for TT1 patients were particularly evident for verbal IQ, BRIEF dimensions "working memory", "plan and organize" and "monitor", ASEBA dimensions "social problems" and "attention problems", and for the SSRS "assertiveness" scale (all p values <0.001). To conclude, TT1 patients showed cognitive impairments on all domains studied, and appeared to be significantly more affected than PKU patients. More attention should be paid to investigating and monitoring neurocognitive outcome in TT1 and research should focus on explaining the underlying pathophysiological mechanism.

Maple syrup urine disease: Characteristics of diagnosis and treatment in 45 patients in Chile.

Maple urine syrup disease (MSUD) is an autosomal recessive disorder characterized by deficient activity of the branched-chain alpha ketoacid dehydrogenase (BCKAD) enzymatic complex due to biallelic variants in the alpha (BCKDHA) or beta (BCKDHB) subunits or the acyltransferase component (DBT). Treatment consists in leucine (LEU), isoleucine (ILE), and valine (VAL) (branched-chain amino acids) dietary restriction and strict metabolic control. to determine the characteristics of the Chilean cohort with MSUD currently in follow-up at Instituto de Nutrición y Tecnología de los Alimentos, during the 1990-2017 period Retrospective analytical study in 45 MSUD cases. Measured: biochemical parameters (LEU, ILE, and VAL), anthropometric evaluation, and neurocognitive development. In 18 cases undergoing genetic study were analyzed according to the gene and protein location, number of affected alleles, and type of posttranslational modification affected. Then, 45 patients with MSUD diagnosis were identified during the period: 37 were alive at the time of the study. Average diagnosis age was 71 ± 231 days. Average serum diagnosis LEU concentrations: 1.463 ± 854.1 µmol/L, VAL 550 ± 598 µmol/L and ILE 454 ± 458 µmol/L. BCKDHB variants explain 89% cases, while BCKDHA and DBT variants explain 5.5% of cases each. Variants p.Thr338Ile in BCKDHA, p.Pro240Thr and p.Ser342Asn in BCKDHB have not been previously reported in literature. Average serum follow-up LEU concentrations were 252.7 ± 16.9 µmol/L in the <5 years group and 299 ± 123.2 µmol/L in ≥5 years. Most cases presented some degree of developmental delay. Early diagnosis and treatment is essential to improve the long-term prognosis. Frequent blood LEU measurements are required to optimize metabolic control and to establish relationships between different aspects analyzed.

A Fast and Accessible Method for the Isolation of RNA, DNA, and Protein To Facilitate the Detection of SARS-CoV-2.

Management of the coronavirus disease 2019 (COVID-19) pandemic requires widespread testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). A main limitation for widespread SARS-CoV-2 testing is the global shortage of essential supplies, among them RNA extraction kits. The need for commercial RNA extraction kits places a bottleneck on tests that detect SARS-CoV-2 genetic material, including PCR-based reference tests. Here, we propose an alternative method we call PEARL (precipitation-enhanced analyte retrieval) that addresses this limitation. PEARL uses a lysis solution that disrupts cell membranes and viral envelopes while simultaneously providing conditions suitable for alcohol-based precipitation of RNA, DNA, and proteins. PEARL is a fast, low-cost, and simple method that uses common laboratory reagents and offers performance comparable to that of commercial RNA extraction kits. PEARL offers an alternative method to isolate host and pathogen nucleic acids and proteins to streamline the detection of DNA and RNA viruses, including SARS-CoV-2.

A Scalable, Easy-to-Deploy Protocol for Cas13-Based Detection of SARS-CoV-2 Genetic Material.

The COVID-19 pandemic has created massive demand for widespread, distributed tools for detecting SARS-CoV-2 genetic material. The hurdles to scalable testing include reagent and instrument accessibility, availability of highly trained personnel, and large upfront investment. Here, we showcase an orthogonal pipeline we call CREST (Cas13-based, rugged, equitable, scalable testing) that addresses some of these hurdles. Specifically, CREST pairs commonplace and reliable biochemical methods (PCR) with low-cost instrumentation, without sacrificing detection sensitivity. By taking advantage of simple fluorescence visualizers, CREST allows a binary interpretation of results. CREST may provide a point-of-care solution to increase the distribution of COVID-19 surveillance.

Clinical outcome of patients with COVID-19 Pneumonia treated with corticosteroids and colchicine in Colombia.

BACKGROUND: To date, there is no specific antiviral therapy for severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2) that causes Coronavirus disease 2019 (Covid-19). Since there is no specific therapy against SARS-CoV2, current efforts aim to prevent contagion through public health measures and develop a protective vaccine. While waiting for the latter, it is necessary to evaluate the drugs that at least, in initial studies, suggested some degree of utility in the management of Covid-19 or its complications. The main objective of the study was to describe the clinical manifestations and outcomes of patients with severe Covid-19 Pneumonia treated with corticosteroids and colchicine. MATERIALS AND METHODS: A cross sectional study of 301 adult patients with Covid-19 Pneumonia confirmed by Real-Time Polymerase Chain Reaction for SARS-CoV2 (RT-PCR SARS-CoV2), Berlin protocol, who required hospitalization in three hospitals in Antioquia, Colombia. Patients were treated according to the institutional protocol (from March 20, 2020 to June 30, 2020) with corticosteroid if the patient required supplemental oxygen. From July 1, 2020, the management protocol changed with the addition of colchicine to all patients admitted to the institutions. The treatment was supervised and monitored by the same specialist in Infectology of the institutions. We describe the clinical manifestations and outcomes of the patients who received these treatments. The information of the patients was analyzed according to the outcome of interest (alive/dead) with univariate, bivariate, and multivariate measures to adjust the variables that presented statistical association. RESULTS: All patients had pneumonia documented by chest computed tomography with ground glass images and presented an alveolar pressure/inspired oxygen fraction (PaFi) less than 300. Three hundred one patients were included, 240 (79.7%) received corticosteroids, within these 145 (48.2%) received colchicine also, and the remaining 61 (20.3%) patients did not receive corticosterioids or colchicine. Mortality in the group that received colchicine was lower compared to the group that did not receive it (9.6 vs 14.6%, p-value = 0.179). CONCLUSIONS: Treatment with corticosteroids and colchicine for managing patients with severe Covid-19 Pneumonia was associated with low mortality at the hospital level. Randomized, placebo-controlled studies are required to evaluate the effect of corticosteroids and colchicine on complications or death from Covid-19.

Case report: Maternal tyrosinemia type 1a under NTBC treatment with tyrosine- and phenylalanine restricted diet in Chile.

We report the case of a 17-year-old girl with Tyrosinemia type 1a who carried a planned pregnancy to term while being under 2-(2-nitro-4-trifluoromethylbenzoyl)-1,3-cyclohexanedione (NTBC, nitisinone) treatment and a tyrosine- and phenylalanine-restricted diet. She was on treatment since 2 months of age with poor metabolic control prior to her pregnancy (tyrosine 838 ± 106 umol/L). NTBC and a low tyrosine and phenylalanine diet were continued during her pregnancy. She unfortunately suffered from urinary tract infection and anemia during her pregnancy, with median plasma tyrosine and phenylalanine levels of 613 ± 106 umol/L (200-400 umol/L) and 40.2 ± 8 umol/L (35-90 umol/L), respectively. After 40 weeks of gestation, the patient gave birth to a healthy boy, with no adverse effects related to the use of NTBC. The newborn presented with a transitory elevation of plasma tyrosine levels and normal phenylalanine, methionine, and succinylacetone levels. By 12 months of age, the child was determined to have normal psychomotor development. At 20 months old, he was diagnosed with a mild developmental delay; however, global cognitive evaluation with the Wechsler Intelligence Scale for Children (WISC) test at 5 years old showed normal performance. Here, we discuss one of the few reported cases of nitisinone treatment during pregnancy and demonstrate a lack of teratogenicity and long-term cognitive disabilities.

The importance of naturally attenuated SARS-CoV-2in the fight against COVID-19.

The current SARS-CoV-2 pandemic is wreaking havoc throughout the world and has rapidly become a global health emergency. A central question concerning COVID-19 is why some individuals become sick and others not. Many have pointed already at variation in risk factors between individuals. However, the variable outcome of SARS-CoV-2 infections may, at least in part, be due also to differences between the viral subspecies with which individuals are infected. A more pertinent question is how we are to overcome the current pandemic. A vaccine against SARS-CoV-2 would offer significant relief, although vaccine developers have warned that design, testing and production of vaccines may take a year if not longer. Vaccines are based on a handful of different designs (i), but the earliest vaccines were based on the live, attenuated virus. As has been the case for other viruses during earlier pandemics, SARS-CoV-2 will mutate and may naturally attenuate over time (ii). What makes the current pandemic unique is that, thanks to state-of-the-art nucleic acid sequencing technologies, we can follow in detail how SARS-CoV-2 evolves while it spreads. We argue that knowledge of naturally emerging attenuated SARS-CoV-2 variants across the globe should be of key interest in our fight against the pandemic.

Religious affiliation and major depressive episode in older adults: a cross-sectional study in six low- and middle- income countries.

BACKGROUND: The relationship of religious affiliation and mental health is complex, and being part of a minority religious group could have negative effects on mental health. In this study, we assessed the association between religious affiliation and major depressive episode (MDE) in older adults (> = 60 years) from China, Ghana, India, Mexico, Russia and South Africa. METHODS: We conducted a secondary analysis of data from the Study on global Ageing and adult health (SAGE), with six nationally-representative community-based samples (n = 21,410). Religious affiliation was self-reported by participants, and we defined MDE based on ICD-10 classification. We estimated the association of MDE with religious affiliation versus no religious affiliation, and minority versus majority affiliation. RESULTS: We observed no association between having a religious affiliation (vs. no affiliation) and the odds of MDE in older adults. In most cases minorities had higher odds of MDE as compared with the majority religion, but the associations were only significant for Muslims in Ghana and for Muslims, Hindus and Other in South Africa. CONCLUSIONS: While the results were significant only for two countries, we observed higher odds of MDE among minorities in most of them. Older adults who are members of religious minorities might be at risk for mental health problems, and there is a need for public health interventions aimed at them.

Zika virus cell tropism in the developing human brain and inhibition by azithromycin.

The rapid spread of Zika virus (ZIKV) and its association with abnormal brain development constitute a global health emergency. Congenital ZIKV infection produces a range of mild to severe pathologies, including microcephaly. To understand the pathophysiology of ZIKV infection, we used models of the developing brain that faithfully recapitulate the tissue architecture in early to midgestation. We identify the brain cell populations that are most susceptible to ZIKV infection in primary human tissue, provide evidence for a mechanism of viral entry, and show that a commonly used antibiotic protects cultured brain cells by reducing viral proliferation. In the brain, ZIKV preferentially infected neural stem cells, astrocytes, oligodendrocyte precursor cells, and microglia, whereas neurons were less susceptible to infection. These findings suggest mechanisms for microcephaly and other pathologic features of infants with congenital ZIKV infection that are not explained by neural stem cell infection alone, such as calcifications in the cortical plate. Furthermore, we find that blocking the glia-enriched putative viral entry receptor AXL reduced ZIKV infection of astrocytes in vitro, and genetic knockdown of AXL in a glial cell line nearly abolished infection. Finally, we evaluate 2,177 compounds, focusing on drugs safe in pregnancy. We show that the macrolide antibiotic azithromycin reduced viral proliferation and virus-induced cytopathic effects in glial cell lines and human astrocytes. Our characterization of infection in the developing human brain clarifies the pathogenesis of congenital ZIKV infection and provides the basis for investigating possible therapeutic strategies to safely alleviate or prevent the most severe consequences of the epidemic.

KSHV 2.0: a comprehensive annotation of the Kaposi's sarcoma-associated herpesvirus genome using next-generation sequencing reveals novel genomic and functional features.

Productive herpesvirus infection requires a profound, time-controlled remodeling of the viral transcriptome and proteome. To gain insights into the genomic architecture and gene expression control in Kaposi's sarcoma-associated herpesvirus (KSHV), we performed a systematic genome-wide survey of viral transcriptional and translational activity throughout the lytic cycle. Using mRNA-sequencing and ribosome profiling, we found that transcripts encoding lytic genes are promptly bound by ribosomes upon lytic reactivation, suggesting their regulation is mainly transcriptional. Our approach also uncovered new genomic features such as ribosome occupancy of viral non-coding RNAs, numerous upstream and small open reading frames (ORFs), and unusual strategies to expand the virus coding repertoire that include alternative splicing, dynamic viral mRNA editing, and the use of alternative translation initiation codons. Furthermore, we provide a refined and expanded annotation of transcription start sites, polyadenylation sites, splice junctions, and initiation/termination codons of known and new viral features in the KSHV genomic space which we have termed KSHV 2.0. Our results represent a comprehensive genome-scale image of gene regulation during lytic KSHV infection that substantially expands our understanding of the genomic architecture and coding capacity of the virus.

Site-specific association with host and viral chromatin by Kaposi's sarcoma-associated herpesvirus LANA and its reversal during lytic reactivation.

UNLABELLED: Latency-associated nuclear antigen (LANA), a multifunctional protein expressed by the Kaposi sarcoma-associated herpesvirus (KSHV) in latently infected cells, is required for stable maintenance of the viral episome. This is mediated by two interactions: LANA binds to specific sequences (LBS1 and LBS2) on viral DNA and also engages host histones, tethering the viral genome to host chromosomes in mitosis. LANA has also been suggested to affect host gene expression, but both the mechanism(s) and role of this dysregulation in KSHV biology remain unclear. Here, we have examined LANA interactions with host chromatin on a genome-wide scale using chromatin immunoprecipitation with high-throughput sequencing (ChIP-seq) and show that LANA predominantly targets human genes near their transcriptional start sites (TSSs). These host LANA-binding sites are generally found within transcriptionally active promoters and display striking overrepresentation of a consensus DNA sequence virtually identical to the LANA-binding site 1 (LBS1) motif in KSHV DNA. Comparison of the ChIP-seq profile with whole-transcriptome (high-throughput sequencing of RNA transcripts [RNA-seq]) data reveals that few of the genes that are differentially regulated in latent infection are occupied by LANA at their promoters. This suggests that direct LANA binding to promoters is not the prime determinant of altered host transcription in KSHV-infected cells. Most surprisingly, the association of LANA to both host and viral DNA is strongly disrupted during the lytic cycle of KSHV. This disruption can be prevented by the inhibition of viral DNA synthesis, suggesting the existence of novel and potent regulatory mechanisms linked to either viral DNA replication or late gene expression. IMPORTANCE: Here, we employ complementary genome-wide analyses to evaluate the distribution of the highly abundant latency-associated nuclear antigen, LANA, on the host genome and its impact on host gene expression during KSHV latent infection. Combined, ChIP-seq and RNA-seq reveal that LANA accumulates at active gene promoters that harbor specific short DNA sequences that are highly reminiscent of its cognate binding sites in the virus genome. Unexpectedly, we found that such association does not lead to remodeling of global host transcription during latency. We also report for the first time that LANA's ability to bind host and viral chromatin is highly dynamic and is disrupted in cells undergoing an extensive lytic reactivation. This therefore suggests that the association of LANA to chromatin during a productive infection cycle is controlled by a new regulatory mechanism.

Exploring the N-glycosylation pathway in Chlamydomonas reinhardtii unravels novel complex structures.

Chlamydomonas reinhardtii is a green unicellular eukaryotic model organism for studying relevant biological and biotechnological questions. The availability of genomic resources and the growing interest in C. reinhardtii as an emerging cell factory for the industrial production of biopharmaceuticals require an in-depth analysis of protein N-glycosylation in this organism. Accordingly, we used a comprehensive approach including genomic, glycomic, and glycoproteomic techniques to unravel the N-glycosylation pathway of C. reinhardtii. Using mass-spectrometry-based approaches, we found that both endogenous soluble and membrane-bound proteins carry predominantly oligomannosides ranging from Man-2 to Man-5. In addition, minor complex N-linked glycans were identified as being composed of partially 6-O-methylated Man-3 to Man-5 carrying one or two xylose residues. These findings were supported by results from a glycoproteomic approach that led to the identification of 86 glycoproteins. Here, a combination of in-source collision-induced dissodiation (CID) for glycan fragmentation followed by mass tag-triggered CID for peptide sequencing and PNGase F treatment of glycopeptides in the presence of (18)O-labeled water in conjunction with CID mass spectrometric analyses were employed. In conclusion, our data support the notion that the biosynthesis and maturation of N-linked glycans in the endoplasmic reticulum and Golgi apparatus occur via a GnT I-independent pathway yielding novel complex N-linked glycans that maturate differently from their counterparts in land plants.

[What should the paediatrician know about hyperphenylalaninaemia?]. / ¿Qué debe saber el pediatra de las hiperfenilalaninemias?

Hyperphenylalaninaemias are defined by a blood phenylalanine over 2mg/dl. The main cause is due to a mutation in the gene that codes the phenylalanine hydroxylase that catalyses the reaction that converts phenylalanine into tyrosine. The hyperphenylalaninaemias are classified into benign or mild hyperphenylalaninaemias, or mild, moderate or classic phenylketonurias. Due to its delayed detection outside the neonatal period it causes severe mental retardation. Its detection along with congenital hypothyroidism has been part of the National Neonatal Screening Program since 1992 in Chile. This article aims to answer the most common questions asked by the paediatrician when faced with a patient with hyperphenylalaninaemias.

Analysis of dietary fats intake and lipid profile in Chilean patients with glucose transport type 1 deficiency syndrome: similarities and differences with the reviewed literature.

Introduction: Glucose transporter type 1 deficiency syndrome (GLUT1-DS) is a neurological disorder caused by mutations in the SLC2A1 gene. The main treatment is ketogenic diet therapy (KDT), which changes the brain's energy substrate from glucose to ketone bodies. The diet controls seizures, but there may be side effects such as dyslipidemia. This study aimed to describe the type of fats ingested by the Chilean cohort of patients with GLUT1-DS and analyze for alterations in the lipid profile. Methods: A GLUT1-DS group and a control group were formed, each with 13 subjects who were matched by age, gender, and nutritional status. Anthropometry, dietary intake, including types of fat, and blood tests were evaluated (lipid and liver profile, and 25-hydroxyvitamin D levels). Results: A high-fat diet, especially saturated fat, was identified in the GLUT1-DS group (38% of total calories), with the use of medium-chain triglycerides (17% of total calories). In addition, GLUT1-DS participants had a higher intake of monounsaturated (MUFA) and polyunsaturated (PUFA) fats and adequate consumption of omega-3 (2% of total calories). Despite the GLUT1-DS group receiving on average 80% of its total energy as fats, it is important to highlight that 50% are MUFA+PUFA fats, there were no significant differences in the lipid and liver profile compared to the control group. Conclusion: KDT did not negatively impact lipid profile, despite a high intake of fats. It is important to monitor lipid profiles, in a personalized and constant manner, to prevent future nutritional risks.

Mantis: high-throughput 4D imaging and analysis of the molecular and physical architecture of cells.

High-throughput dynamic imaging of cells and organelles is essential for understanding complex cellular responses. We report Mantis, a high-throughput 4D microscope that integrates two complementary, gentle, live-cell imaging technologies: remote-refocus label-free microscopy and oblique light-sheet fluorescence microscopy. Additionally, we report shrimPy, an open-source software for high-throughput imaging, deconvolution, and single-cell phenotyping of 4D data. Using Mantis and shrimPy, we achieved high-content correlative imaging of molecular dynamics and the physical architecture of 20 cell lines every 15 minutes over 7.5 hours. This platform also facilitated detailed measurements of the impacts of viral infection on the architecture of host cells and host proteins. The Mantis platform can enable high-throughput profiling of intracellular dynamics, long-term imaging and analysis of cellular responses to perturbations, and live-cell optical screens to dissect gene regulatory networks.

Food insecurity in high-risk rural communities before and during the COVID-19 pandemic.

Objective: To perform a geospatial analysis of food insecurity in a rural county known to have poor health outcomes and assess the effect of the COVID-19 pandemic. Methods: In 2020, we mailed a comprehensive cross-sectional survey to all households in Sullivan County, a rural county with the second-worst health outcomes among all counties in New York State. Surveys of households included validated food insecurity screening questions. Questions were asked in reference to 2019, prior to the pandemic, and for 2020, in the first year of the pandemic. Respondents also responded to demographic questions. Raking adjustments were performed using age, sex, race/ethnicity, and health insurance strata to mitigate non-response bias. To identify significant hotspots of food insecurity within the county, we also performed geospatial analysis. Findings: From the 28,284 households surveyed, 20% of households responded. Of 4725 survey respondents, 26% of households reported experiencing food insecurity in 2019, and in 2020, this proportion increased to 35%. In 2020, 58% of Black and Hispanic households reported experiencing food insecurity. Food insecurity in 2020 was also present in 58% of unmarried households with children and in 64% of households insured by Medicaid. The geospatial analyses revealed that hotspots of food insecurity were primarily located in or near more urban areas of the rural county. Conclusions: Our countywide health survey in a high-risk rural county identified significant increases of food insecurity in the first year of the COVID-19 pandemic, despite national statistics reporting a stable rate. Responses to future crises should include targeted interventions to bolster food security among vulnerable rural populations.

Site-specific cleavage of the host poly(A) binding protein by the encephalomyocarditis virus 3C proteinase stimulates viral replication.

Although picornavirus RNA genomes contain a 3'-terminal poly(A) tract that is critical for their replication, the impact of encephalomyocarditis virus (EMCV) infection on the host poly(A)-binding protein (PABP) remains unknown. Here, we establish that EMCV infection stimulates site-specific PABP proteolysis, resulting in accumulation of a 45-kDa N-terminal PABP fragment in virus-infected cells. Expression of a functional EMCV 3C proteinase was necessary and sufficient to stimulate PABP cleavage in uninfected cells, and bacterially expressed 3C cleaved recombinant PABP in vitro in the absence of any virus-encoded or eukaryotic cellular cofactors. N-terminal sequencing of the resulting C-terminal PABP fragment identified a 3C(pro) cleavage site on PABP between amino acids Q437 and G438, severing the C-terminal protein-interacting domain from the N-terminal RNA binding fragment. Single amino acid substitution mutants with changes at Q437 were resistant to 3C(pro) cleavage in vitro and in vivo, validating that this is the sole detectable PABP cleavage site. Finally, while ongoing protein synthesis was not detectably altered in EMCV-infected cells expressing a cleavage-resistant PABP variant, viral RNA synthesis and infectious virus production were both reduced. Together, these results establish that the EMCV 3C proteinase mediates site-specific PABP cleavage and demonstrate that PABP cleavage by 3C regulates EMCV replication.

Muscle and Bone Health in Young Chilean Adults with Phenylketonuria and Different Degrees of Compliance with the Phenylalanine Restricted Diet.

There are concerns about muscle and bone health in patients with Phenylketonuria (PKU). Our aim was to compare muscle mass, function, and bone health among young adults with PKU who maintained or suspended dietary treatment. METHODS: Three groups were considered-PKU-1: 10 patients who used a protein substitute (PS) without phenylalanine (Phe); PKU-2: 14 patients who used the PS without Phe until eighteen years old and then practiced mostly a vegan diet; and 24 matched healthy controls. A 24 h recall survey, blood parameters, body composition and bone mineral density through DEXA, rectus femoris thickness by ultrasound, hand grip strength, submaximal exercise test, and walking speed were assessed. RESULTS: PKU-1 patients had lower hand grip strength than their matched controls, but no other differences. Compared to controls, the PKU-2 group had lower fat-free mass (p = 0.01), less spine and femoral bone mineral density (p = 0.04 and p < 0.01, respectively), and peak workload on the incremental test (p = 0.03). When comparing PKU groups, blood Phe levels were significantly lower in the PKU-1 group (p = 0.02). CONCLUSIONS: Among PKU patients, abandoning the dietary treatment and maintaining high blood Phe concentrations could be deleterious for muscles and bones. However, we cannot discard other causes of bone and muscle damage in these patients.

Risk of Developing Insulin Resistance in Adult Subjects with Phenylketonuria: Machine Learning Model Reveals an Association with Phenylalanine Concentrations in Dried Blood Spots.

Phenylketonuria (PKU) is an autosomal recessive inborn error of metabolism where high phenylalanine (Phe) concentrations cause irreversible intellectual disability that can be prevented by newborn screening and early treatment. Evidence suggests that PKU subjects not adherent to treatment could be at risk of insulin resistance (IR). We studied how Phe concentrations (PheCs) relate to IR using machine learning (ML) and derived potential biomarkers. In our cross-sectional study, we analyzed subjects with neonatal diagnoses of PKU, grouped as follows: 10 subjects who adhered to treatment (G1); 14 subjects who suspended treatment (G2); and 24 control subjects (G3). We analyzed plasma biochemical variables, as well as profiles of amino acids and acylcarnitines in dried blood spots (DBSs). Higher PheCs and plasma insulin levels were observed in the G2 group compared to the other groups. Additionally, a positive correlation between the PheCs and homeostatic measurement assessments (HOMA-IRs) was found, as well as a negative correlation between the HOMA-Sensitivity (%) and quantitative insulin sensitivity check index (QUICKI) scores. An ML model was then trained to predict abnormal HOMA-IRs using the panel of metabolites measured from DBSs. Notably, ranking the features' importance placed PheCs as the second most important feature after BMI for predicting abnormal HOMA-IRs. Our results indicate that low adherence to PKU treatment could affect insulin signaling, decrease glucose utilization, and lead to IR.