Phase 1/2 study of CPX-351 for patients with Int-2 or high risk International Prognostic Scoring System myelodysplastic syndromes and chronic myelomonocytic leukaemia after failure to hypomethylating agents.

Failure after hypomethylating agents (HMAs) is associated with dismal outcomes in higher risk myelodysplastic syndromes (HR-MDS) or chronic myelomonocytic leukaemia (CMML). We aimed to evaluate the safety and preliminary activity of lower doses of CPX-351, a liposomal encapsulation of cytarabine and daunorubicin, in a single-centre, phase 1/2 study for patients with HR-MDS or CMML after HMA failure. Four doses of CPX-351 (10, 25, 50 and 75 units/m2 ) administered on Days 1, 3 and 5 of induction and Days 1 and 3 of consolidation were evaluated. Between June 2019 and June 2023, 25 patients were enrolled (phase 1: n = 15; phase 2: n = 10) including 19 (76%) with HR-MDS and 6 (24%) with CMML. Most common grade 3-4 non-haematological treatment-emergent adverse events were febrile neutropenia (n = 12, 48%) and lung infection (n = 5, 20%). Three patients (age >75) experienced cardiac toxicity at the 75 units/m2 dose. Further enrolment continued at 50 units/m2 . Four- and 8-week mortality were 0% and 8% respectively. The overall response rate was 56% with median relapse-free and overall survivals of 9.2 (95% CI 3.2-15.1 months) and 8.7 months (95% CI 1.8-15.6 months) respectively. These data suggest that lower doses of CPX-351 are safe. Further studies are needed to evaluate its activity.

Buparlisib, a PI3K inhibitor, demonstrates acceptable tolerability and preliminary activity in a phase I trial of patients with advanced leukemias.

Phosphatidylinositol-3-kinase (PI3K) signaling plays a crucial role in oncogene-mediated tumor growth and proliferation. Buparlisib (BKM120) is an oral pan-class I PI3K inhibitor. This phase I study was conducted to determine the dose limiting toxicity (DLT) and maximum tolerated dose (MTD) of BKM120 in patients (pts) with relapsed/refractory acute leukemias. Fourteen pts (12 acute myeloid leukemia, 1 acute lymphoblastic leukemia, and 1 mixed phenotype leukemia) were enrolled. Twelve pts received BKM-120 80 mg/day and two 100 mg/day. The MTD was 80 mg/day. Of the 14 patients treated, the best response was stable disease in one patient that lasted 82 days. The median survival for all patients was 75 days (range 10-568). Three patients with a 3q26 chromosome abnormality had a significantly improved median survival of 360 days (range 278-568) as compared to a median survival of 57 days (range, 10-125) among the 11 other patients. The most frequent drug-related toxicities included confusion, mucositis, dysphagia, and fatigue. Western blot profiling revealed a decrease in p-pS6K/total pS6K in 5/7 (71%) available patient samples with a mean quantitative inhibition of 65% (range, 32-100%) and a decrease in p-FOXO3/total FOXO3 in 4/6 (67%) samples with a mean quantitative inhibition of 93% (range, 89-100%). BKM120 administered at 80 mg/day showed modest efficacy and was tolerable in advanced acute leukemias. Am. J. Hematol. 92:7-11, 2017. © 2016 Wiley Periodicals, Inc.

Safety and efficacy of rivastigmine in children with Down syndrome: A double blind placebo controlled trial.

Individuals with Down syndrome (DS) have decreased cholinergic function and an uneven profile of cognitive abilities, with more pronounced deficits in learning, memory, and expressive language. Cholinesterase inhibitors may improve cognitive function in adults and adolescents with DS, but studies in children with DS have been limited. This study aimed to: (i) investigate the safety and efficacy of rivastigmine treatment; (ii) build upon our open-label studies in children with DS in a double-blind, placebo-controlled clinical trial; and (iii) investigate specific cognitive domains that may respond to rivastigmine treatment. We conducted a 20-week double-blind, placebo-controlled trial to investigate the safety and efficacy of rivastigmine in 22 children and adolescents with DS aged 10-17 years. Safety measures included reports of adverse events, laboratory parameters, and electrocardiograms. Efficacy measures included parental assessments of adaptive behavior and executive function, and direct measures of language and memory. No group differences were found on safety measures and 22 of 24 participants that passed study screening completed the study. The results did not demonstrate evidence for significant improvement in aspects of cognition, language, or overall function in the children receiving rivastigmine. Our results suggest that rivastigmine is safe and well-tolerated for children and adolescents with DS, but may not be effective for improving performance on the selected measures in this study. However, larger samples and/or alternate measures could possibly reveal improvements in cognitive function with rivastigmine treatment. Further research is needed to define a battery of cognitive measures that is sensitive to treatment effects in DS. © 2016 Wiley Periodicals, Inc.

Geographic variation in climate as a proxy for climate change: Forecasting evolutionary trajectories from species differentiation and genetic correlations.

PREMISE OF THE STUDY: Climate change models for California predict a warmer, drier future, potentially resulting in shorter growing seasons. If phenotypic differences between closely related species currently distributed across a moisture and temperature gradient represent adaptations to their abiotic environment, then as conditions become warmer and drier, populations presently adapted to cooler and wetter conditions may evolve to become more similar to those adapted to warmer and drier conditions. Two sister species, Clarkia unguiculata and C. exilis, are distributed across a moisture and temperature gradient in the southern Sierra Nevada, providing an opportunity to predict how this process may occur. METHODS: In a greenhouse experiment using wild-collected seeds from 11 populations in the southern Sierra Nevada, we examined relationships among elevation, climatic conditions, and population means for each trait, then evaluated bivariate relationships among maternal family means, using raw values and controlling for population and seed mass effects on phenotype. KEY RESULTS: Clarkia exilis occupied warmer, drier conditions, typically at lower elevations, than C. unguiculata did and flowered earlier and faster, producing smaller flowers with lower herkogamy. In C. unguiculata, petal area, herkogamy, and the rate of flower production were positively correlated with days to first flower. CONCLUSIONS: If selection favors earlier flowering, smaller petals, or faster flower production in C. unguiculata, then the genetic correlations among these traits should reinforce their joint evolution. Moreover, the correlations between these traits and herkogamy may promote the evolution of self-fertilization as an indirect response to selection, a previously unrecognized potential outcome of climate change.

Evolutionary insights from studies of geographic variation: Contemporary variation and looking to the future.

In an age of rapid global change, it is imperative that we continue to improve our understanding of factors that govern genetic differentiation in plants to inform biologically reasonable predictions for the future and enlighten conservation and restoration practices. In this special issue, we have assembled a set of original research and reviews that employ diverse approaches, both classic and contemporary, to illuminate patterns of phenotypic and genetic variation, probe the underlying evolutionary processes that have contributed to these patterns, build predictive models, and test evolutionary hypotheses. Our goal was to underscore the unique insights that can be obtained through the complementary and distinct studies of plant populations across species' geographic ranges.

Project Baseline: An unprecedented resource to study plant evolution across space and time.

PREMISE OF THE STUDY: Project Baseline is a seed bank that offers an unprecedented opportunity to examine spatial and temporal dimensions of microevolution during an era of rapid environmental change. Over the upcoming 50 years, biologists will withdraw genetically representative samples of past populations from this time capsule of seeds and grow them contemporaneously with modern samples to detect any phenotypic and molecular evolution that has occurred during the intervening time. METHODS: We carefully developed this living genome bank using protocols to enhance its experimental value by collecting from multiple populations and species across a broad geographical range in sites that are likely to be preserved into the future. Seeds are accessioned with site and population data and are stored by maternal line under conditions that maximize seed longevity. This open-access resource will be available to researchers at regular intervals to evaluate contemporary evolution. KEY RESULTS: To date, the Project Baseline collection includes 100-200 maternal lines of each of 61 species collected from over 831 populations on sites that are likely to be preserved into the future across the United States (∼78,000 maternal lines). Our strategically designed collection circumvents some problems that can cloud the results of "resurrection" studies involving naturally preserved or existing seed collections that are available fortuitously. CONCLUSIONS: The resurrection approach can be coupled with long-established and newer techniques over the next five decades to elucidate genetic change and thereby vastly improve our understanding of temporal and spatial changes in phenotype and the evolutionary processes underlying it.

Phase 1 study of azacitidine in combination with quizartinib in patients with FLT3 or CBL mutated MDS and MDS/MPN.

We conducted a phase 1 study evaluating 3 dose levels of quizartinib (30 mg, 40 mg or 60 mg) in combination with azacitidine for HMA-naïve or relapsed/refractory MDS or MDS/MPN with FLT3 or CBL mutations. Overall, 12 patients (HMA naïve: n=9, HMA failure: n=3) were enrolled; 7 (58 %) patients had FLT3 mutations and 5 (42 %) had CBL mutations. The maximum tolerated dose was not reached. Most common grade 3-4 treatment-emergent adverse events were thrombocytopenia (n=5, 42 %), anemia (n=4, 33 %), lung infection (n=2, 17 %), skin infection (n=2, 17 %), hyponatremia (n=2, 17 %) and sepsis (n=2, 17 %). The overall response rate was 83 % with median relapse-free and overall survivals of 15.1 months (95 % CI 0.0-38.4 months) and 17.5 months (95 % CI NC-NC), respectively. FLT3 mutation clearance was observed in 57 % (n=4) patients. These data suggest quizartinib is safe and shows encouraging activity in FLT3-mutated MDS and MDS/MPN. This study is registered at Clinicaltrials.gov as NCT04493138.

LIMITED ACCUMULATION AND PERSISTENCE OF AN INFLUENZA A VIRUS IN TADPOLE SNAILS (PHYSA SPP.).

Waterfowl infected with avian influenza A viruses (IAVs) shed infectious virus into aquatic environments, providing a mechanism for transmission among waterfowl, while also exposing the entire aquatic ecosystem to the virus. Aquatic invertebrates such as freshwater snails are likely exposed to IAVs in the water column and sediment. Freshwater snails comprise a significant portion of some waterfowl species' diets, so this trophic interaction may serve as a novel route of IAV transmission. In these experiments, tadpole snails (Physa spp.) were exposed to a low-pathogenicity IAV (H3N8) to determine whether snails can accumulate the virus and, if so, how long virus persists in snail tissues. Snail tissues were destructively sampled and tested by reverse-transcription quantitative real-time PCR. Our experiments demonstrated that tadpole snails do accumulate IAV RNA in their tissues, although at low titers, for at least 96 h. These results indicate that it may be possible for IAV transmission to occur between waterfowl via ingestion of a natural invertebrate prey item; however, the time frame for transmission may be limited.

Complementary adhesin function in C. albicans biofilm formation.

BACKGROUND: Biofilms are surface-associated microbial communities with significant environmental and medical impact. Here, we focus on an adherence mechanism that permits biofilm formation by Candida albicans, the major invasive fungal pathogen of humans. RESULTS: The Als surface-protein family has been implicated in biofilm formation, and we show that Als1 and Als3 have critical but redundant roles. Overexpression of several other Als proteins permits biofilm formation in a biofilm-defective als1/als1 als3/als3 strain, thus arguing that the function of Als proteins in this process is governed by their respective expression levels. The surface protein Hwp1 is also required for biofilm formation, and we find that a mixture of biofilm-defective hwp1/hwp1 and als1/als1 als3/als3 strains can form a hybrid biofilm both in vitro and in vivo in a catheter infection model. Complementary function of Hwp1 and Als1 and 3 seems to reflect their interaction because expression of Hwp1 in the heterologous host S. cerevisiae permits adherence to wild-type C. albicans, but not to an als1/als1 als3/als3 strain. CONCLUSIONS: The complementary roles of Hwp1 and Als1 and Als3 in biofilm formation are analogous to the roles of sexual agglutinins in mating reactions. This analogy suggests that biofilm-adhesin complementarity may promote formation of monospecies biofilms.

Parent versus teacher ratings on the BRIEF-preschool version in children with and without ADHD.

Caregiver rating scales represent an important component of comprehensive child neuropsychological assessments for conditions such as Attention-deficit/Hyperactivity Disorder (ADHD); however, low inter-rater reliability (parent vs. teacher) often complicates interpretation. It has been challenging to identify the factors contributing to inter-rater variability, particularly when parents and teachers complete slightly different versions of the same rating scale. The present study examined the associations between parent- and teacher-reported executive functions in 84 children, ages 4-5 years, with and without symptoms of ADHD, using the Behavior Rating Inventory of Executive Function-Preschool (BRIEF-P). Use of the BRIEF-P allows for direct comparison of symptom ratings because parents and teachers complete the exact same measure. Significant associations between raters were observed on 4 of 5 BRIEF-P subscales when rating children with ADHD, but on only 1 subscale when rating typically developing (TD) children. The Shift scale in particular displayed low, non-significant inter-rater association in both groups. Significant group-by-rater interactions were observed for Working Memory and Plan/Organize scales, and driven by larger inter-rater T-score discrepancies in the TD group, such that teachers rated children as having more symptoms than parents. Conversely, examination of raw scores reflected no significant rater differences in the TD group, but significant or nearly significant differences on multiple scales in the ADHD group, such that parents rated more symptoms than teachers. Inter-rater associations for the BRIEF-P appear to vary based on who is being rated (i.e., children with or without ADHD), the specific subscales, and whether standardized or raw scores are analyzed.

A systematic review of the methodology used to study weight change among young adults attending college.

INTRODUCTION: Young adulthood is a sensitive developmental period that is high-risk for weight gain. Ample research has focused on weight gain among college students; however meta-analyses report <2 kg pooled estimates of weight gain, which is in the range of normal weight fluctuation, and there is disagreement in the literature regarding common predictors of weight gain. These limitations pose a major barrier to targeted obesity prevention efforts. The present study reviewed the literature assessing college weight gain with a focus on three methodological factors that could contribute to variability in the literature: 1) use of an evidence-supported definition of weight gain (>2 kg or ≥3%); 2) weight measurement protocols; and 3) including weight/BMI in analyses of predictors of weight change. METHODS: Three databases were systematically searched. Studies were included in the review if the primary goal was to determine magnitude of weight change and/or test predictors of weight change during the academic year, and they reported weight at 2+ time points. RESULTS: A total of 81 studies were included in the review. Most studies (90%; 73/81) did not use an evidence-supported definition of weight gain. Studies that used an evidence-supported definition reported estimates of gain among students who gained weight to be beyond the range of normal weight fluctuation (4.0-7.5 kg), and occurred in a subset (<32%) of participants. Studies that did not use an evidence-supported definition reported weight gain to be 2.0-4.5 kg, and occurred in the majority >50% of students. Most studies that measured height and weight (71%; 42/59) did not use a fasting protocol and the majority (63%; 37/59) did not conduct measurements at the same time of day. A higher percentage of studies that used a standardized measurement protocol reported weight change >2 kg (44% vs 20%). A lower percentage of studies that used a standardized measurement protocol had substantial variability in weight change estimates (50% vs 69%). The majority of studies that tested predictors of weight gain (74%; 42/57) included weight/BMI as a covariate in analyses. CONCLUSIONS: The body of literature examining weight change among college students suffers from limitations that may have contributed to overestimations in the percent of students who gain weight, and simultaneous underestimations of the magnitude of weight gain among those who gain weight. Weight gain may be limited to approximately 30% of students in a sample, and weight gain among this subset of students may be substantial (>4 kg). Going forward, use of both an evidence-supported weight gain definition and fasting measurement protocol will likely enhance accuracy in characterizing weight gain among college students, as well as improve researchers' ability to detect important predictors of weight gain.

Changes in male breast cancer over a 30-year period.

Male breast cancer is a rare clinical entity accounting for approximately 1 per cent of all breast cancers. The present study investigated changes in patient characteristics, disease patterns, treatment, and outcomes over a 30-year period. A retrospective chart review was performed on male breast cancer patients treated between 1975 and 2005 at Eastern Virginia Medical School, Norfolk, VA. Demographic, pathologic, treatment, and survival information was collected. To facilitate comparison of trends, the patients were divided into two groups: Cohort A (1972-1991, previously reported) and Cohort B (1992-2005). Both cohorts included 28 male patients. Comparing the cohorts, no statistical differences were noted in median age, ethnicity, presenting symptoms, or progesterone receptor status. In Cohort A, 70 per cent of patients were estrogen receptor positive, compared with 100 per cent of Cohort B (P = 0.02). Her2/neu was positive in three of five patients in Cohort B. There was a trend toward more conservative surgery, with no radical mastectomy or orchiectomy performed in Cohort B. Only two patients had sentinel lymph node mapping, both from Cohort B. Infiltrating ductal carcinoma was more prevalent in Cohort B (P = 0.04). For Cohort A and B, 5-year survival was 43 per cent and 51 per cent, respectively, which was not statistically significant. For male breast cancer, radical mastectomy is no longer a common treatment modality. Male breast cancer of today is more hormonally responsive which may have important implications for therapy. Survival has not significantly improved over the previous 30 years. Compilation of multi-institutional data of male breast cancer is needed to advance the treatment of this uncommon disease.

Preschool Inhibitory Control Predicts ADHD Group Status and Inhibitory Weakness in School.

OBJECTIVE: Discriminative utility of performance measures of inhibitory control was examined in preschool children with and without ADHD to determine whether performance measures added to diagnostic prediction and to prediction of informant-rated day-to-day executive function. METHOD: Children ages 4-5 years (N = 105, 61% boys; 54 ADHD, medication-naïve) were assessed using performance measures (Auditory Continuous Performance Test for Preschoolers-Commission errors, Conflicting Motor Response Test, NEPSY Statue) and caregiver (parent, teacher) ratings of inhibition (Behavior Rating Inventory of Executive Function-Preschool version). RESULTS: Performance measures and parent and teacher reports of inhibitory control significantly and uniquely predicted ADHD group status; however, performance measures did not add to prediction of group status beyond parent reports. Performance measures did significantly predict classroom inhibitory control (teacher ratings), over and above parent reports of inhibitory control. CONCLUSIONS: Performance measures of inhibitory control may be adequate predictors of ADHD status and good predictors of young children's classroom inhibitory control, demonstrating utility as components of clinical assessments.

Developmental Trajectory of Motor Deficits in Preschool Children with ADHD.

Motor deficits persisting into childhood (>7 years) are associated with increased executive and cognitive dysfunction, likely due to parallel neural circuitry. This study assessed the longitudinal trajectory of motor deficits in preschool children with ADHD, compared to typically developing (TD) children, in order to identify individuals at risk for anomalous neurological development. Participants included 47 children (21 ADHD, 26 TD) ages 4-7 years who participated in three visits (V1, V2, V3), each one year apart (V1=48-71 months, V2=60-83 months, V3=72-95 months). Motor variables assessed included speed (finger tapping and sequencing), total overflow, and axial movements from the Revised Physical and Neurological Examination for Subtle Signs (PANESS). Effects for group, visit, and group-by-visit interaction were examined. There were significant effects for group (favoring TD) for finger tapping speed and total axial movements, visit (performance improving with age for all 4 variables), and a significant group-by-visit interaction for finger tapping speed. Motor speed (repetitive finger tapping) and quality of axial movements are sensitive markers of anomalous motor development associated with ADHD in children as young as 4 years. Conversely, motor overflow and finger sequencing speed may be less sensitive in preschool, due to ongoing wide variations in attainment of these milestones.

Phase I study of ruxolitinib in previously treated patients with low or intermediate-1 risk myelodysplastic syndrome with evidence of NF-kB activation.

Therapeutic options for patients with lower-risk myelodysplastic syndrome (MDS) who have failed prior therapies are limited particularly after hypomethylating agent. Several studies have indicated that deregulation of innate immunity signaling is critical in the pathogenesis of MDS. This process involves Toll-like receptor stimulation, cytokine overexpression, and nuclear factor-kB (NF-kB) activation. Since ruxolitinib, a JAK1/JAK2 inhibitor, suppresses NF-kB expression, we conducted a phase 1 dose-escalation study to determine the safety and efficacy of ruxolitinib in previously treated lower-risk MDS patients with evidence of NF-kB activation. Nineteen patients, 8 with chronic myelomonocytic leukemia and 11 with MDS, were enrolled. No dose limiting toxicity was observed and the maximum tolerated dose was 20 mg twice daily. Responses were restricted to MDS patients with an overall response rate of 22% [hematological improvement in platelets (HI-P) = 2, hematological improvement in erythrocytes (HI-E) = 1, partial cytogenetic response (PCyR) = 1]. Of these patients, 2 relapsed (HI-P and PCyR) and 2 continue to be in HI-P and HI-E, respectively, with ongoing therapy. Meaningful improvement in bone marrow dysplasia was only seen in a patient who achieved HI-E. Phosphorylated p65 (pp65) decreased in 6 of 15 patients (40%) including the 2 patients with continued response to treatment and increased in a patient who relapsed after a short-lived HI-P. This suggests potential correlation between reduction in pp65 expression and response duration. In conclusion, ruxolitinib was well-tolerated in previously treated lower-risk MDS patients with evidence of NF-kB activation and resulted in low but significant frequency of responses. (NCT01895842).

Serum biomarkers to differentiate benign and malignant mammographic lesions.

BACKGROUND: Mammographic screening has increased detection of earlier-stage breast cancers and has decreased mortality from breast cancer. A Breast Imaging-Reporting and Data System (BIRADS) 4 classification prompts a biopsy that most often reveals benign disease. Our objective was to determine if serum protein-expression profiles could be used to differentiate between benign and malignant mammographic lesions. STUDY DESIGN: After IRB approval, women undergoing an image-guided biopsy for a BIRADS category 4 lesion were recruited. Serum was collected prebiopsy and labeled retrospectively after final pathology was reviewed. Serum was incubated with weak cation exchange magnetic beads and assayed in duplicate for analysis on matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) instrumentation (Bruker Daltonics). Spectra were analyzed using ClinProTools 2.0 software (Bruker Daltonics), and classifications determined using a genetic-clustering algorithm. RESULTS: In a 14-month period, 260 subjects were recruited into this study. Sera from 92 subjects were randomly selected to form benign (n = 46) and cancer (n = 46) cohorts. The MALDI-TOF spectra analysis yielded 273 peaks, with 14 peaks expressed differentially (p < 0.05) between the cancer and benign cohorts. A genetic algorithm model was generated, yielding a sensitivity of 88.3% and specificity of 85.8%. CONCLUSIONS: MALDI-TOF protein-expression profiles generated from BIRADS 4 sera could be used to distinguish between benign and malignant mammographic lesions.

Sleep disturbance and neuropsychological function in young children with ADHD.

Sleep disturbance, common among children with ADHD, can contribute to cognitive and behavioral dysfunction. It is therefore challenging to determine whether neurobehavioral dysfunction should be attributed to ADHD symptoms, sleep disturbance, or both. The present study examined parent-reported sleep problems (Children's Sleep Habits Questionnaire) and their relationship to neuropsychological function in 64 children, aged 4-7 years, with and without ADHD. Compared to typically developing controls, children with ADHD were reported by parents to have significantly greater sleep disturbance--including sleep onset delay, sleep anxiety, night awakenings, and daytime sleepiness--(all p ≤ .01), and significantly poorer performance on tasks of attention, executive control, processing speed, and working memory (all p < .01). Within the ADHD group, total parent-reported sleep disturbance was significantly associated with deficits in attention and executive control skills (all p ≤ .01); however, significant group differences (relative to controls) on these measures remained (p < .01) even after controlling for total sleep disturbance. While sleep problems are common among young children with ADHD, these findings suggest that inattention and executive dysfunction appear to be attributable to symptoms of ADHD rather than to sleep disturbance. The relationships among sleep, ADHD symptoms, and neurobehavioral function in older children may show different patterns as a function of the chronicity of disordered sleep.

Utility of the test of memory malingering (TOMM) in children ages 4-7 years with and without ADHD.

There is growing consensus that assessment for non-credible performance is a necessary component of pediatric neuropsychological examination. The current study examined the utility and validity of the Test of Memory Malingering (TOMM) in children ages 4-7 years with and without Attention-deficit/Hyperactivity Disorder (ADHD); 66 children (30 controls, 36 ADHD) completed all three TOMM trials. There were no significant group differences in total score on any trial, or passing rate for Trial 2 or Retention. Four-year-olds with ADHD achieved "passing" score on Trial 1 less often than controls. Across groups, performance on Trial 2 and Retention improved with age, such that 85% of the sample achieved a passing score. Four-year-olds had greater difficulty and achieved a passing score significantly less often than children 5-7 years. Moreover, half of the 4-year-olds performed worse on Retention than Trial 2, calling into question the utility of the Retention trial at this age. Performance was associated with IQ only within the ADHD group on the Retention trial. Results suggest that the TOMM can be used with confidence in clinical groups as young as 5 years. Among 4-year-olds, performance appears dependent on severity of ADHD or disruptive behaviors, and may be associated with factors other than effort.

UV-photoconversion of ethosuximide from a longevity-promoting compound to a potent toxin.

The anticonvulsant ethosuximide has been previously shown to increase life span and promote healthspan in the nematode Caenorhabditis elegans at millimolar concentrations. Here we report that following exposure to ultraviolet irradiation at 254 nm, ethosuximide is converted into a compound that displays toxicity toward C. elegans. This effect is specific for ethosuximide, as the structurally related compounds trimethadione and succinimide do not show similar toxicities following UV exposure. Killing by UV-irradiated ethosuximide is not attenuated in chemosensory mutants that are resistant to toxicity associated with high doses of non-irradiated ethosuximide. Non-irradiated ethosuximide extends life span at 15°C or 20°C, but not at 25°C, while irradiated ethosuximide shows similar toxicity at all three temperatures. Dietary restriction by bacterial deprivation does not protect against toxicity from irradiated ethosuximide, while non-irradiated ethosuximide further extends the long life spans of restricted animals. These data support the model that ethosuximide extends life span by a mechanism that is, at least partially, distinct from dietary restriction by bacterial deprivation and demonstrates an unexpected photochemical conversion of ethosuximide into a toxic compound by UV light.

Heparin alters viral serpin, serp-1, anti-thrombolytic activity to anti-thrombotic activity.

Serine protease inhibitors (serpins) regulate coagulation and inflammation. Heparin, a glycosaminoglycan, is an important cofactor for modulation of the inhibitory function of mammalian serpins. The secreted myxoma viral serpin, Serp-1 exerts profound anti-inflammatory activity in a wide range of animal models. Serp-1 anti-inflammatory and anti-atherogenic activity is dependent upon inhibition of the uPA / uPA receptor thrombolytic complex. We demonstrate here that heparin binds to Serp-1 and enhances Serp-1 inhibition of thrombin, a human pro-thrombotic serine protease, in vitro, altering inhibitory activity to a more predominant anti-thrombotic activity. Heparin also facilitates the simultaneous thrombin-mediated cleavage of Serp-1 and prevents formation of a serpin-typical SDS-resistant complex, implying mutual neutralization of Serp-1 and thrombin. In a cell-based assay, heparin facilitates Serp-1 reversal of cellular activation by stabilizing cellular membrane fluidity in thrombin-activated monocytes. In conclusion, heparin and other GAGs serve as cofactors enhancing Serp-1 regulation of local thrombotic and inflammatory pathways.