Drug Resistance Assessed in a Phase 3 Clinical Trial of Maribavir Therapy for Refractory or Resistant Cytomegalovirus Infection in Transplant Recipients.

BACKGROUND: This drug resistance analysis of a randomized trial includes 234 patients receiving maribavir and 116 receiving investigator-assigned standard therapy (IAT), where 56% and 24%, respectively, cleared cytomegalovirus DNA at week 8 (treatment responders). METHODS: Baseline and posttreatment plasma samples were tested for mutations conferring drug resistance in viral genes UL97, UL54, and UL27. RESULTS: At baseline, genotypic testing revealed resistance to ganciclovir, foscarnet, or cidofovir in 56% of patients receiving maribavir and 68% receiving IAT, including 9 newly phenotyped mutations. Among them, 63% (maribavir) and 21% (IAT) were treatment responders. Detected baseline maribavir resistance mutations were UL27 L193F (n = 1) and UL97 F342Y (n = 3). Posttreatment, emergent maribavir resistance mutations were detected in 60 (26%) of those randomized to maribavir, including 49 (48%) of 103 nonresponders and 25 (86%) of the 29 nonresponders where viral DNA initially cleared then rebounded while on maribavir. The most common maribavir resistance mutations were UL97 T409M (n = 34), H411Y (n = 26), and C480F (n = 21), first detected 26 to 130 (median 56) days after starting maribavir. CONCLUSIONS: Baseline maribavir resistance was rare. Drug resistance to standard cytomegalovirus antivirals did not preclude treatment response to maribavir. Rebound in plasma cytomegalovirus DNA while on maribavir strongly suggests emerging drug resistance. CLINICAL TRIALS REGISTRATION: NCT02931539.

Treatment for First Cytomegalovirus Infection Post-Hematopoietic Cell Transplant in the AURORA Trial: A Multicenter, Double-Blind, Randomized, Phase 3 Trial Comparing Maribavir With Valganciclovir.

BACKGROUND: Neutropenia may limit the use of valganciclovir treatment for cytomegalovirus (CMV) infection following hematopoietic cell transplant (HCT). A phase 2 study indicated efficacy of maribavir with fewer treatment-limiting toxicities than valganciclovir. METHODS: In this multicenter, double-blind, phase 3 study, patients with first asymptomatic CMV infection post-HCT were stratified and randomized 1:1 to maribavir 400 mg twice daily or valganciclovir (dose-adjusted for renal clearance) for 8 weeks with 12 weeks of follow-up. The primary endpoint was confirmed CMV viremia clearance at week 8 (primary hypothesis of noninferiority margin of 7.0%). The key secondary endpoint was a composite of the primary endpoint with no findings of CMV tissue-invasive disease at week 8 through week 16. Treatment-emergent adverse events (TEAEs) were assessed. RESULTS: Among patients treated (273 maribavir; 274 valganciclovir), the primary endpoint of noninferiority of maribavir was not met (maribavir, 69.6%; valganciclovir, 77.4%; adjusted difference: -7.7%; 95% confidence interval [CI]: -14.98, -.36; lower limit of 95% CI of treatment difference exceeded -7.0%). At week 16, 52.7% and 48.5% of patients treated (maribavir and valganciclovir, respectively) maintained CMV viremia clearance without tissue-invasive disease (adjusted difference: 4.4%; 95% CI: -3.91, 12.76). With maribavir (vs valganciclovir), fewer patients experienced neutropenia (16.1% and 52.9%) or discontinued due to TEAEs (27.8% and 41.2%). Discontinuations were mostly due to neutropenia (maribavir, 4.0%; valganciclovir, 17.5%). CONCLUSIONS: Although noninferiority of maribavir to valganciclovir for the primary endpoint was not achieved based on the prespecified noninferiority margin, maribavir demonstrated comparable CMV viremia clearance during post-treatment follow-up, with fewer discontinuations due to neutropenia. Clinical Trials Registration. NCT02927067 [AURORA].

p53 activation during ribosome biogenesis regulates normal erythroid differentiation.

The role of ribosome biogenesis in erythroid development is supported by the recognition of erythroid defects in ribosomopathies in both Diamond-Blackfan anemia and 5q- syndrome. Whether ribosome biogenesis exerts a regulatory function on normal erythroid development is still unknown. In the present study, a detailed characterization of ribosome biogenesis dynamics during human and murine erythropoiesis showed that ribosome biogenesis is abruptly interrupted by the decline in ribosomal DNA transcription and the collapse of ribosomal protein neosynthesis. Its premature arrest by the RNA Pol I inhibitor CX-5461 targeted the proliferation of immature erythroblasts. p53 was activated spontaneously or in response to CX-5461, concomitant to ribosome biogenesis arrest, and drove a transcriptional program in which genes involved in cell cycle-arrested, negative regulation of apoptosis, and DNA damage response were upregulated. RNA Pol I transcriptional stress resulted in nucleolar disruption and activation of the ATR-CHK1-p53 pathway. Our results imply that the timing of ribosome biogenesis extinction and p53 activation is crucial for erythroid development. In ribosomopathies in which ribosome availability is altered by unbalanced production of ribosomal proteins, the threshold downregulation of ribosome biogenesis could be prematurely reached and, together with pathological p53 activation, prevents a normal expansion of erythroid progenitors.

RTEL1 maintains genomic stability by suppressing homologous recombination.

Homologous recombination (HR) is an important conserved process for DNA repair and ensures maintenance of genome integrity. Inappropriate HR causes gross chromosomal rearrangements and tumorigenesis in mammals. In yeast, the Srs2 helicase eliminates inappropriate recombination events, but the functional equivalent of Srs2 in higher eukaryotes has been elusive. Here, we identify C. elegans RTEL-1 as a functional analog of Srs2 and describe its vertebrate counterpart, RTEL1, which is required for genome stability and tumor avoidance. We find that rtel-1 mutant worms and RTEL1-depleted human cells share characteristic phenotypes with yeast srs2 mutants: lethality upon deletion of the sgs1/BLM homolog, hyperrecombination, and DNA damage sensitivity. In vitro, purified human RTEL1 antagonizes HR by promoting the disassembly of D loop recombination intermediates in a reaction dependent upon ATP hydrolysis. We propose that loss of HR control after deregulation of RTEL1 may be a critical event that drives genome instability and cancer.

REC-1 and HIM-5 distribute meiotic crossovers and function redundantly in meiotic double-strand break formation in Caenorhabditis elegans.

The Caenorhabditis elegans gene rec-1 was the first genetic locus identified in metazoa to affect the distribution of meiotic crossovers along the chromosome. We report that rec-1 encodes a distant paralog of HIM-5, which was discovered by whole-genome sequencing and confirmed by multiple genome-edited alleles. REC-1 is phosphorylated by cyclin-dependent kinase (CDK) in vitro, and mutation of the CDK consensus sites in REC-1 compromises meiotic crossover distribution in vivo. Unexpectedly, rec-1; him-5 double mutants are synthetic-lethal due to a defect in meiotic double-strand break formation. Thus, we uncovered an unexpected robustness to meiotic DSB formation and crossover positioning that is executed by HIM-5 and REC-1 and regulated by phosphorylation.

Rhabditophanes diutinus a parthenogenetic clade IV nematode with dauer larvae.

Comparative studies using non-parasitic model species such as Caenorhabditis elegans, have been very helpful in investigating the basic biology and evolution of parasitic nematodes. However, as phylogenetic distance increases, these comparisons become more difficult, particularly when outside of the nematode clade to which C. elegans belongs (V). One of the reasons C. elegans has nevertheless been used for these comparisons, is that closely related well characterized free-living species that can serve as models for parasites of interest are frequently not available. The Clade IV parasitic nematodes Strongyloides are of great research interest due to their life cycle and other unique biological features, as well as their medical and veterinary importance. Rhabditophanes, a closely related free-living genus, forms part of the Strongyloidoidea nematode superfamily. Rhabditophanes diutinus (= R. sp. KR3021) was included in the recent comparative genomic analysis of the Strongyloididae, providing some insight into the genomic nature of parasitism. However, very little is known about this species, limiting its usefulness as a research model. Here we provide a species description, name the species as R. diutinus and investigate its life cycle and subsequently gene expression in multiple life stages. We identified two previously unreported starvation induced life stages: dauer larvae and arrested J2 (J2A) larvae. The dauer larvae are morphologically similar to and are the same developmental stage as dauers in C. elegans and infective larvae in Strongyloides. As in C. elegans and Strongyloides, dauer formation is inhibited by treatment with dafachronic acid, indicating some genetic control mechanisms are conserved. Similarly, the expression patterns of putative dauer/infective larva control genes resemble each other, in particular between R. diutinus and Strongyloides spp. These findings illustrate and increase the usefulness of R. diutinus as a non-parasitic, easy to work with model species for the Strongyloididae for studying the evolution of parasitism as well as many aspects of the biology of Strongyloides spp, in particular the formation of infective larvae.

An open-label phase 2 trial to assess the efficacy, safety and pharmacokinetics of lanthanum carbonate in hyperphosphatemic children and adolescents with chronic kidney disease undergoing dialysis.

BACKGROUND: This study assessed the efficacy, tolerability and pharmacokinetics (PK) of lanthanum carbonate (LC) in hyperphosphatemic children and adolescents with chronic kidney disease (CKD) undergoing dialysis. METHODS: This was a three-part, multicenter, open-label study of LC (oral powder formulation) in patients 10 to < 18 years old with CKD undergoing dialysis. In part 1, the single-dose PK of LC (500 mg, ≤12 years old; 1000 mg, > 12 years old) were summarized. In part 2, patients received calcium carbonate (CC [chewable tablet formulation]) (1500-6500 mg [total daily dose]) followed by LC (powder formulation) (1500-3000 mg [total daily dose]), or LC only (1500-3000 mg [total daily dose]), each for 8 weeks. During part 3, patients received LC (1500-3000 mg [total daily dose]) for up to 6 months. The primary efficacy endpoint was the proportion of LC-treated patients achieving serum phosphorus control after 8 weeks during parts 2 and/or 3, defined as: ≤1.94 mmol/L, < 12 years old; ≤1.78 mmol/L, ≥12 years old. Secondary efficacy endpoints included: the proportion of patients who achieved serum phosphorus control after 8 weeks of treatment with CC followed by 8 weeks of treatment with LC (with a washout period between treatments). The safety of LC and CC was also evaluated. RESULTS: In part 1, 20 patients received a single dose of LC. In part 2, 53 and 51 patients were treated with CC and LC for 8 weeks, respectively. During part 3, 42 patients received LC for up to 6 months. Most patients were white and male. For the primary efficacy endpoint, 50% (17/34) of patients who received LC for 8 weeks during parts 2 and/or 3 achieved serum phosphorus control. After 8 weeks of treatment with CC, 58.8% of patients achieved serum phosphorus control; after a subsequent washout period and 8 weeks of treatment with LC, 70.6% of patients achieved serum phosphorus control. Tmax and t1/2 occurred within 3-8 h and ~ 19 h, respectively; however, variability was observed. LC and CC were generally well tolerated. CONCLUSIONS: These data support the use of LC to manage hyperphosphatemia in pediatric patients with CKD undergoing dialysis. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT01696279; EudraCT identifier: 2012-000171-17. Date of registration: 01/10/2012.

BCL-2 Inhibitor ABT-737 Effectively Targets Leukemia-Initiating Cells with Differential Regulation of Relevant Genes Leading to Extended Survival in a NRAS/BCL-2 Mouse Model of High Risk-Myelodysplastic Syndrome.

During transformation, myelodysplastic syndromes (MDS) are characterized by reducing apoptosis of bone marrow (BM) precursors. Mouse models of high risk (HR)-MDS and acute myelogenous leukemia (AML) post-MDS using mutant NRAS and overexpression of human BCL-2, known to be poor prognostic indicators of the human diseases, were created. We have reported the efficacy of the BCL-2 inhibitor, ABT-737, on the AML post-MDS model; here, we report that this BCL-2 inhibitor also significantly extended survival of the HR-MDS mouse model, with reductions of BM blasts and lineage negative/Sca1+/KIT+ (LSK) cells. Secondary transplants showed increased survival in treated compared to untreated mice. Unlike the AML model, BCL-2 expression and RAS activity decreased following treatment and the RAS:BCL-2 complex remained in the plasma membrane. Exon-specific gene expression profiling (GEP) of HR-MDS mice showed 1952 differentially regulated genes upon treatment, including genes important for the regulation of stem cells, differentiation, proliferation, oxidative phosphorylation, mitochondrial function, and apoptosis; relevant in human disease. Spliceosome genes, found to be abnormal in MDS patients and downregulated in our HR-MDS model, such as Rsrc1 and Wbp4, were upregulated by the treatment, as were genes involved in epigenetic regulation, such as DNMT3A and B, upregulated upon disease progression and downregulated upon treatment.

Influence of toilet access on antiretroviral adherence intention among pregnant and breastfeeding women who are HIV-positive and enrolled in Option B.

We investigated the influence of toilet access on intention to adhere to antiretroviral therapy (ART) among women who are HIV-positive and enrolled in Option B+. A convenience sample of 150 women residing in Lusaka (urban) and Sinazongwe (rural) Districts of Zambia were recruited. if they were seeking pre- or post-natal care and were enrolled in Option B+. Intention to adhere to ART was assessed using four questions based on the Theory of Planned Behavior; the median score was used to distinguish high intention from low intention. Descriptive statistics were used to characterize access to toilet facilities and ART adherence intention in the entire sample and by rural and urban districts in Zambia. There was no significant difference (p = .19) between rural and urban women's access to a flush toilet. After adjusting for toilet access, however, rural women were significantly less likely to be in the high adherence intention group (PR = 0.80, 95% CI 0.71-0.90, p < .001) but access to a flush toilet was associated with adherence intention (PR = 1.14, 95% CI (1.00 - 1.30). Community-led total sanitation in Zambia could increase ART adherence intention.

Impact of attitudes and beliefs on antiretroviral treatment adherence intention among HIV-positive pregnant and breastfeeding women in Zambia.

OBJECTIVE: The aim of this study was to investigate if attitudes or behavioral beliefs about antiretroviral therapy (ART) influence ART adherence intention among pregnant and breastfeeding women in Zambia. METHODS: We recruited 150 HIV-positive women receiving ART in urban (Lusaka) and rural (Sinazongwe) districts of Zambia. Generalized modified Poisson regression models were used to assess the extent to which adherence intention was influenced by attitude toward ART or behavioral beliefs about ART. RESULTS: Intention to adhere to ART differed significantly by income, knowledge about HIV transmission, attitudes, and behavioral beliefs (all Ps < .05). In addition, strong intention to adhere to ART differed by urban (69%) and rural (31%) place of residence (P ≤ .01). In adjusted models, women in the weak adherence intention group were more likely to be older, have less knowledge about HIV transmission, and have a more negative attitude toward ART (PR 0.74; 95% CI 0.67-0.82). Behavioral belief about ART, however, was significant in unadjusted model (PR 0.85; 95% CI 0.76-0.94) but not significant after adjusting for covariates such as age, knowledge of transmission, and district locality. CONCLUSION: Compared to behavioral beliefs, attitudes about ART were more influential for intention to adhere. This knowledge will help inform effective and appropriate ART counseling for pregnant and breastfeeding women at different points along their ART time course.

Mediating the relationship between loneliness and cognitive function: the role of depressive and anxiety symptoms.

Objective: To evaluate the relationship between loneliness and cognitive functioning, and whether depressive and anxiety symptoms have intermediate roles therein.Methods: Information about 7,433 participants of the Irish Longitudinal Study on Ageing (a prospective, representative cohort study), aged over 50, was collected at three time-points two years apart, and analysed using Structural Equation Modelling to assess whether depressive and anxiety symptoms mediate the relationship between loneliness and cognitive functioning. Cognitive functioning was measured as a latent factor, with four indicators: measures of immediate and delayed word recall, verbal fluency, and a global measure (the MMSE). Loneliness was measured using the UCLA Loneliness scale, depressive symptoms using the CES-D-ML scale, and anxiety symptoms using the HADS-A scale.Results: Loneliness at time-point 1 predicted cognitive functioning at time-point 3, ß = -0.103, p < 0.001, and depressive (ß = 0.426, p < 0.001) and anxiety (ß = 0.410, p < 0.001) symptoms at time-point 2. Depressive (ß = -0.020, p = 0.001) but not anxiety (ß = -0.000, p = 0.658) symptoms mediated the relationship between loneliness and cognitive functioning, total effect: ß = -0.123, p < 0.001.Conclusion: The relationship between loneliness and cognitive functioning is in part explained by its relationship with depressive symptoms. Statistically, the mediation model helps us understand possible mechanisms through which loneliness impacts cognitive functioning. Results have implications for cognitive functioning interventions for older adults, and imply that loneliness is also a worthwhile target for intervention.

DANPY (dimethylaminonaphthylpyridinium): an economical and biocompatible fluorophore.

Dyes with nonlinear optical (NLO) properties enable new imaging techniques and photonic systems. We have developed a dye (DANPY-1) for photonics applications in biological substrates such as nucleic acids; however, the design specification also enables it to be used for visualizing biomolecules. It is a prototype dye demonstrating a water-soluble, NLO-active fluorophore with high photostability, a large Stokes shift, and a favorable toxicity profile. A practical and scalable synthetic route to DANPY salts has been optimized featuring: (1) convergent Pd-catalyzed Suzuki coupling with pyridine 4-boronic acid, (2) site-selective pyridyl N-methylation, and (3) direct recovery of crystalline intermediates without chromatography. We characterize the optical properties, biocompatibility, and biological staining behavior of DANPY-1. In addition to stability and solubility across a range of polar media, the DANPY-1 chromophore shows a first hyperpolarizability similar to common NLO dyes such as Disperse Red 1 and DAST, a large two-photon absorption cross section for its size, substantial affinity to nucleic acids in vitro, an ability to stain a variety of cellular components, and strong sensitivity of its fluorescence properties to its dielectric environment.

Comparisons of the discrepancy between loneliness and social isolation across Ireland and Sweden: findings from TILDA and SNAC-K.

PURPOSE: Loneliness may have different cultural meanings in different countries. This may manifest as differing levels of Social Asymmetry-the discrepancy between loneliness and social isolation. Since loneliness is thought to be low in Sweden relative to more southerly countries, we hypothesised that more number of individuals would also fall into the "discordant robust" category of Social Asymmetry, i.e. that more individuals in Sweden would have lower loneliness levels relative to social isolation than in Ireland. We also explored the clinical relevance of Social Asymmetry in both countries, by examining its association with cognitive functioning. METHODS: We derived Social Asymmetry metrics in two representative cohort studies: the Irish Longitudinal Study on Ageing (TILDA) and the Swedish National Study on Aging and Care in Kungsholmen (SNAC-K). Data pertaining to a dementia-free sample of 4565 Irish participants and 3042 Swedish participants, all aged over 60 years, were analysed using a multilevel modelling approach, with country as a higher-order variable. RESULTS: Contrary to the expected, more individuals in Ireland were "discordant robust" than in Sweden. We also found evidence for superior performance in global cognitive functioning among those in the "discordant robust" category relative to those in the discordant susceptible (i.e. those with higher levels of loneliness than social isolation) category, ß = 0.61, p < .001, across both countries. CONCLUSIONS: Irish older adults may be more robust to the impact of social isolation on loneliness than those in the Swedish cohort. Social Asymmetry was related to cognitive functioning in both countries, suggesting that Social Asymmetry is a clinically relevant construct.

Genomic identification and functional analysis of essential genes in Caenorhabditis elegans.

BACKGROUND: Essential genes are required for an organism's viability and their functions can vary greatly, spreading across many pathways. Due to the importance of essential genes, large scale efforts have been undertaken to identify the complete set of essential genes and to understand their function. Studies of genome architecture and organization have found that genes are not randomly disturbed in the genome. RESULTS: Using combined genetic mapping, Illumina sequencing, and bioinformatics analyses, we successfully identified 44 essential genes with 130 lethal mutations in genomic regions of C. elegans of around 7.3 Mb from Chromosome I (left). Of the 44 essential genes, six of which were genes not characterized previously by mutant alleles, let-633/let-638 (B0261.1), let-128 (C53H9.2), let-511 (W09C3.4), let-162 (Y47G6A.18), let-510 (Y47G6A.19), and let-131 (Y71G12B.6). Examine essential genes with Hi-C data shows that essential genes tend to cluster within TAD units rather near TAD boundaries. We have also shown that essential genes in the left half of chromosome I in C. elegans function in enzyme and nucleic acid binding activities during fundamental processes, such as DNA replication, transcription, and translation. From protein-protein interaction networks, essential genes exhibit more protein connectivity than non-essential genes in the genome. Also, many of the essential genes show strong expression in embryos or early larvae stages, indicating that they are important to early development. CONCLUSIONS: Our results confirmed that this work provided a more comprehensive picture of the essential gene and their functional characterization. These genetic resources will offer important tools for further heath and disease research.

Cardiovascular risk factors and frailty in a cross-sectional study of older people: implications for prevention.

Objective: to examine the associations of cardiovascular disease (CVD) and cardiovascular risk factors with frailty. Design: a cross-sectional study. Setting: the Irish Longitudinal Study on Ageing (TILDA). Participants: frailty measures were obtained on 5,618 participants and a subset of 4,330 participants with no prior history of CVD. Exposures for observational study: cardiovascular risk factors were combined in three composite CVD risk scores (Systematic Coronary Risk Evaluation [SCORE], Ideal Cardiovascular Health [ICH] and Cardiovascular Health Metrics [CHM]). Main outcome measures: a frailty index (40-items) was used to screen for frailty. Methods: the associations of CVD risk factors with frailty were examined using logistic regression. Results: overall, 16.4% of participants had frailty (7.6% at 50-59 years to 42.5% at 80+ years), and the prevalence was higher in those with versus those without prior CVD (43.0% vs. 10.7%). Among those without prior CVD, mean levels of CVD risk factors were closely correlated with higher frailty index scores. Combined CVD risk factors, assessed using SCORE, were linearly and positively associated with frailty. Compared to low-to-moderate SCOREs, the odds ratio (OR) (95% confidence interval, CI) of frailty for those with very high risk was 3.18 (2.38-4.25). Conversely, ICH was linearly and inversely associated with frailty, with an OR for optimal health of 0.29 (0.21-0.40) compared with inadequate health. Conclusions: the concordant positive associations of SCORE and inverse associations of ICH and CHM with frailty highlight the potential importance of optimum levels of CVD risk factors for prevention of disability in frail older people.

Genome Sequence and Transcriptome Analyses of Chrysochromulina tobin: Metabolic Tools for Enhanced Algal Fitness in the Prominent Order Prymnesiales (Haptophyceae).

Haptophytes are recognized as seminal players in aquatic ecosystem function. These algae are important in global carbon sequestration, form destructive harmful blooms, and given their rich fatty acid content, serve as a highly nutritive food source to a broad range of eco-cohorts. Haptophyte dominance in both fresh and marine waters is supported by the mixotrophic nature of many taxa. Despite their importance the nuclear genome sequence of only one haptophyte, Emiliania huxleyi (Isochrysidales), is available. Here we report the draft genome sequence of Chrysochromulina tobin (Prymnesiales), and transcriptome data collected at seven time points over a 24-hour light/dark cycle. The nuclear genome of C. tobin is small (59 Mb), compact (∼ 40% of the genome is protein coding) and encodes approximately 16,777 genes. Genes important to fatty acid synthesis, modification, and catabolism show distinct patterns of expression when monitored over the circadian photoperiod. The C. tobin genome harbors the first hybrid polyketide synthase/non-ribosomal peptide synthase gene complex reported for an algal species, and encodes potential anti-microbial peptides and proteins involved in multidrug and toxic compound extrusion. A new haptophyte xanthorhodopsin was also identified, together with two "red" RuBisCO activases that are shared across many algal lineages. The Chrysochromulina tobin genome sequence provides new information on the evolutionary history, ecology and economic importance of haptophytes.

Mediators of the relationship between social activities and cognitive function among older Irish adults: results from the Irish longitudinal study on ageing.

OBJECTIVE: Evidence points to an association between social and leisure activity (SLA) engagement and cognitive outcomes, but the mechanisms underlying this link remain unknown. We aimed to investigate three potential mechanisms: Vascular function, Perceived Stress, and Cognitive Reserve. METHODS: With data from 8163 adults aged over 50 in the Irish Longitudinal Study of Ageing, we used a structural equation model to evaluate Vascular Function and Perceived Stress as potential mediators, and Cognitive Reserve as a potential antecedent in the relationship between SLA at baseline (2009), and cognitive outcomes collected at a two-year follow-up point (2011). RESULTS: Cognitive Reserve was strongly associated both with cognitive outcomes (ß = 0.306; p < 0.001) and with SLA (ß = 0.694; p < 0.001). Perceived stress (ß = 0.018) acted as a significant mediator in the relationships between SLA and cognitive outcomes (p < 0.001), although Vascular Function did not (ß = 0.000). CONCLUSION: These results indicate that SLA may protect cognitive function partly because of its association with cognitive reserve, and partly through its impact on perceived stress. Results have policy implications for those interested in facilitating SLA to protect cognitive outcomes among older adults.

Type 2 diabetes in a 5-year-old and single center experience of type 2 diabetes in youth under 10.

The worrisome rise in pediatric type 2 diabetes (T2DM) is most prevalent among minority ethnic/racial populations. Typically, T2DM occurs during puberty in high risk obese adolescents with evidence of insulin resistance. Screening for T2DM in obese youth can be a daunting task for pediatricians and differentiating between pediatric T1DM and T2DM in obese youth can be challenging for pediatric endocrinologists. There is very limited data regarding the prevalence of T2DM among youth < 10 years of age. Here we present the case of a 5-year-old Hispanic male diagnosed with T2DM after referral by his pediatrician for abnormal weight gain, acanthosis nigricans and an elevated HbgA1c. He subsequently became symptomatic for diabetes with confirmed hyperglycemia and HbgA1c of 9.7% (83 mmol/mol) at the time of formal diagnosis. Type 1 diabetes autoantibodies (GAD65, Islet, and ZincT8) and monogenic diabetes genetic tests were negative. Due to elevated liver enzymes and baseline HbgA1c, he received basal insulin as his initial therapy. In this paper, we will discuss this case and present an IRB approved retrospective review of the characteristics of the 20 T2DM patients <10 years of age identified to date in our pediatric diabetes center. This review highlights that while uncommon, the diagnosis of T2DM merits consideration even in prepubertal children. This is especially true when working with a high risk population, such as our Hispanic South Texas youth.

Extensive horizontal gene transfer, duplication, and loss of chlorophyll synthesis genes in the algae.

BACKGROUND: Two non-homologous, isofunctional enzymes catalyze the penultimate step of chlorophyll a synthesis in oxygenic photosynthetic organisms such as cyanobacteria, eukaryotic algae and land plants: the light-independent (LIPOR) and light-dependent (POR) protochlorophyllide oxidoreductases. Whereas the distribution of these enzymes in cyanobacteria and land plants is well understood, the presence, loss, duplication, and replacement of these genes have not been surveyed in the polyphyletic and remarkably diverse eukaryotic algal lineages. RESULTS: A phylogenetic reconstruction of the history of the POR enzyme (encoded by the por gene in nuclei) in eukaryotic algae reveals replacement and supplementation of ancestral por genes in several taxa with horizontally transferred por genes from other eukaryotic algae. For example, stramenopiles and haptophytes share por gene duplicates of prasinophytic origin, although their plastid ancestry predicts a rhodophytic por signal. Phylogenetically, stramenopile pors appear ancestral to those found in haptophytes, suggesting transfer from stramenopiles to haptophytes by either horizontal or endosymbiotic gene transfer. In dinoflagellates whose plastids have been replaced by those of a haptophyte or diatom, the ancestral por genes seem to have been lost whereas those of the new symbiotic partner are present. Furthermore, many chlorarachniophytes and peridinin-containing dinoflagellates possess por gene duplicates. In contrast to the retention, gain, and frequent duplication of algal por genes, the LIPOR gene complement (chloroplast-encoded chlL, chlN, and chlB genes) is often absent. LIPOR genes have been lost from haptophytes and potentially from the euglenid and chlorarachniophyte lineages. Within the chlorophytes, rhodophytes, cryptophytes, heterokonts, and chromerids, some taxa possess both POR and LIPOR genes while others lack LIPOR. The gradual process of LIPOR gene loss is evidenced in taxa possessing pseudogenes or partial LIPOR gene compliments. No horizontal transfer of LIPOR genes was detected. CONCLUSIONS: We document a pattern of por gene acquisition and expansion as well as loss of LIPOR genes from many algal taxa, paralleling the presence of multiple por genes and lack of LIPOR genes in the angiosperms. These studies present an opportunity to compare the regulation and function of por gene families that have been acquired and expanded in patterns unique to each of various algal taxa.