Feasible diet and circadian interventions reduce in vivo progression of FLT3-ITD-positive acute myeloid leukemia

BACKGROUND

Acute myeloid leukemia (AML) with an internal tandem duplication in the fms-like tyrosine kinase receptor 3 gene (FLT3-ITD) is associated with poor survival, and few studies have examined the impact of modifiable behaviors, such as nutrient quality and timing, in this subset of acute leukemia.

METHODS

The influence of diet composition (low-sucrose and/or low-fat diets) and timing of diet were tested in tandem with anthracycline treatment in orthotopic xenograft mouse models. A pilot clinical study to test receptivity of pediatric leukemia patients to macronutrient matched foods was conducted. A role for the circadian protein, BMAL1 (brain and muscle ARNT-like 1), in effects of diet timing was studied by overexpression in FLT3-ITD-bearing AML cells.

RESULTS

Reduced tumor burden in FLT3-ITD AML-bearing mice was observed with interventions utilizing low-sucrose and/or low-fat diets, or time-restricted feeding (TRF) compared to mice fed normal chow ad libitum. In a tasting study, macronutrient matched low-sucrose and low-fat meals were offered to pediatric acute leukemia patients who largely reported liking the meals. Expression of the circadian protein, BMAL1, was heightened with TRF and the low-sucrose diet. BMAL1 overexpression and treatment with a pharmacological inducer of BMAL1 was cytotoxic to FLT3-ITD AML cells.

CONCLUSIONS

Mouse models for FLT3-ITD AML show that diet composition and timing slows progression of FLT3-ITD AML growth in vivo, potentially mediated by BMAL1. These interventions to enhance therapy efficacy show preliminary feasibility, as pediatric leukemia patients responded favorable to preparation of macronutrient matched meals.

Meta-analysis of pre-clinical studies on the effects of opioid receptor ligands on food intake, motivation, and choice

The opioid receptors (OR) regulate food intake. Still, despite extensive pre-clinical research, the overall effects and individual contribution of the mu (MOR), kappa (KOR), and delta (DOR) OR subtypes to feeding behaviors and food intake remain unclear. To address this, we conducted a pre-registered systematic search and meta-analysis of rodent dose-response studies to evaluate the impact of central and peripheral administration of non-selective and selective OR ligands on intake, motivation, and choice of food. All studies had a high bias risk. Still, the meta-analysis confirmed the overall orexigenic and anorexigenic effects of OR agonists and antagonists, respectively. Our results support a larger orexigenic role for central MOR agonists among OR subtypes and that peripheral OR antagonists reduce motivation for and intake of preferred foods. In binary food choice studies, peripheral OR agonists selectively increase the intake of fat-preferred foods; in contrast, they did not increase the intake of sweet carbohydrate-preferred foods. Overall, these data support that OR regulation of intake, motivation, and choice is influenced by food macronutrient composition.

Natural products from plants targeting key enzymes for the future development of antidiabetic agents

Covering: 2000 to January 2023Diabetes is a metabolic disease of serious concern nowadays, with a negative economic impact. In 2021, the International Diabetes Federation estimated that more than 537 million adults live with diabetes, causing over 6.7 million deaths in that year. Intensive scientific research on medicinal plants in the last 100 years reveals that herbal drugs have been an essential source of products for developing antidiabetic agents acting on different physiological targets. This review summarizes recent research from 2000 to 2022 on plant natural compounds affecting selected crucial enzymes (dipeptidyl peptidase IV, diacylglycerol acyltransferase, fructose 1,6-biphosphatase, glucokinase, and fructokinase) involved in glucose homeostasis. Enzyme-aimed treatments usually induce reversible inhibition, irreversible by covalent changes of the objective enzymes, or bind non-covalently but so tightly that their inhibition is irreversible. Depending on the binding site, these inhibitors could be orthosteric or allosteric; in any case, the desired pharmacological action is achieved. One crucial advantage of targeting enzymes in drug discovery is that the required assays are usually simple, using biochemical experiments capable of analyzing enzyme activity.

Abstract 726: Effects of diet composition and timing on treatment for FLT3 positive acute myeloid leukemia

Acute myeloid leukemia (AML) with a mutation in the fms-like tyrosine kinase receptor 3 gene (FLT3) confers poor survival for pediatric patients, indicating a significant need to improve treatment efficacy. A significant percentage of pediatric patients consume diets high in fat and sugar content. These macronutrients modulate oxidative stress yet their impact on AML treatment is unexplored. Studies have implicated a role for BMAL1 rhythmicity, a circadian clock protein, in leukemogenesis. However, BMAL1 has not been studied in FLT3 mutant AML. Given that both nutrition and circadian rhythmicity can be modulated by behavior, we hypothesized that modulating redox and BMAL1 status through diet composition and timing would enhance treatment efficacy in an orthotopic mouse model.

In all in vivo experiments, mice were injected via tail vein with 100,000 MOLM13 luciferase labelled cells, a FLT3 AML human cell line. After engraftment was confirmed 3 days later, mice were put on diet modification regimens. In three subsequent experiments, distinct diet interventions were delivered: low fat (30%)/low sucrose (10%), low sucrose alone (10%), or an isocaloric time feeding regimen (TRF) restricted to mice’s active phase (7 PM to 7 AM). Standard chow, high sucrose diet (45%) and ad libitum feeding were controls, respectively. In each experiment, doxorubicin (2 mg/kg) or PBS was injected twice weekly via tail vein. Tumor burden was monitored via bioluminescent imaging. Reactive oxygen species (ROS) levels were assessed with flow cytometry, and changes in circadian, redox, and apoptotic protein expression were measured by western blot and mass cytometry.

On day 17, in the presence of doxorubicin, mice on a low fat/low sucrose diet showed significantly lower tumor burden compared to control. Doxorubicin induced oxidative stress was reduced in the mice fed the modified diet as demonstrated by a decrease in ROS levels in peripheral blood mononuclear cells. Even in the absence of doxorubicin treatment, the modified diet group showed significantly lower tumor burden on day 17. For mice on a low sucrose diet, changes in redox and circadian protein expression were observed on day 17. Of note, total BMAL1 protein showed a two-fold increase in spleen from the low sucrose group. In the timed feeding experiments, we observed TRF mice had significantly reduced leukemic burden on day 14. Importantly, doxorubicin efficacy was not compromised by TRF. In addition, a significant increase in total BMAL1 protein expression was observed in liver from these TRF mice on day 14.

These results point to a novel finding: diet composition and timing slows progression of FLT3 AML growth in vivo and are accompanied by BMAL1 modulation. In future studies, we aim to further define the role of circadian rhythmicity and diet composition in AML progression and identify methods to complement treatment to positively impact survival outcomes for patients diagnosed with AML.

Citation Format: Megan Rodriguez, Mary Figueroa, Brianna Murphy, Tiewei Cheng, Baharan Fekry, Kendra Allton, Michelle Barton, Marina Konopleva, Kristin Mahan, Joya Chandra. Effects of diet composition and timing on treatment for FLT3 positive acute myeloid leukemia [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 726.

Anaerobic RSH-dependent tellurite reduction contributes to Escherichia coli tolerance against tellurite

BACKGROUND

Tellurium is a rare metalloid that exerts high toxicity on cells, especially on bacteria, partly due to reactive oxygen species (ROS) generation. Moreover, it has also been observed that tellurite can target free cell thiols groups (RSH) (i.e. reduced glutathione (GSH)), enhancing the cellular redox imbalance. Additionally, in vitro experiments have suggested that several enzymes can reduce tellurite (IV) to its elemental form (0); where RSH present on their active sites may be responsible for the process. Nevertheless, the mechanisms implemented by bacteria for tellurite reduction and its role in resistance have not been evaluated in vivo.

RESULTS

This work shows that tellurite reduction to elemental tellurium is increased under anaerobic conditions in E. coli cells. The in vivo tellurite reduction is related to the intracellular concentration of total RSH, in the presence and absence of oxygen. This metabolization of tellurite directly contributes to the resistance of the bacteria to the oxyanion.

CONCLUSIONS

We demonstrated that in vivo tellurite reduction is related to the intracellular thiol concentration, i.e. large availability of cellular RSH groups, results in a more significant reduction of tellurite. Furthermore, we observed that, when the bacterium exhibits less resistance to the oxyanion, a decreased tellurite reduction was seen, affecting the growth fitness. Together, these results let us propose that tellurite reduction and the intracellular RSH content are related to the oxyanion bacterial resistance, this tripartite mechanism in an oxygen-independent anaerobic process.

Computational immune infiltration analysis of pediatric high-grade gliomas (pHGGs) reveals differences in immunosuppression and prognosis by tumor location

Immunotherapy for cancer has moved from pre-clinical hypothesis to successful clinical application in the past 15 years. However, not all cancers have shown response rates in clinical trials for these new agents, high-grade gliomas in particular have proved exceedingly refractory to immunotherapy. In adult patients, there has been much investigation into these failures, and researchers have concluded that an immunosuppressive microenvironment combined with low mutational burden render adult glioblastomas "immune cold". Pediatric cancer patients develop gliomas at a higher rate per malignancy than adults, and their brain tumors bear even fewer mutations. These tumors can also develop in more diverse locations in the brain, beyond the cerebral hemispheres seen in adults, including in the brainstem where critical motor functions are controlled. While adult brain tumor immune infiltration has been extensively profiled from surgical resections, this is not possible for brainstem tumors which can only be sampled at autopsy. Given these limitations, there is a dearth of information on immune cells and their therapeutic and prognostic impact in pediatric high-grade gliomas (pHGGs), including hemispheric tumors in addition to brainstem. In this report we use computational methods to examine immune infiltrate in pHGGs and discover distinct immune patterns between hemispheric and brainstem tumors. In hemispheric tumors, we find positive prognostic associations for regulatory T-cells, memory B-cells, eosinophils, and dendritic cells, but not in brainstem tumors. These differences suggest that immunotherapeutic approaches must be cognizant of pHGG tumor location and tailored for optimum efficacy.

Pharmacologic inhibition of lysine-specific demethylase 1 as a therapeutic and immune-sensitization strategy in pediatric high-grade glioma

BACKGROUND

Diffuse midline gliomas (DMG), including brainstem diffuse intrinsic pontine glioma (DIPG), are incurable pediatric high-grade gliomas (pHGG). Mutations in the H3 histone tail (H3.1/3.3-K27M) are a feature of DIPG, rendering them therapeutically sensitive to small-molecule inhibition of chromatin modifiers. Pharmacological inhibition of lysine-specific demethylase 1 (LSD1) is clinically relevant but has not been carefully investigated in pHGG or DIPG.

METHODS

Patient-derived DIPG cell lines, orthotopic mouse models, and pHGG datasets were used to evaluate effects of LSD1 inhibitors on cytotoxicity and immune gene expression. Immune cell cytotoxicity was assessed in DIPG cells pretreated with LSD1 inhibitors, and informatics platforms were used to determine immune infiltration of pHGG.

RESULTS

Selective cytotoxicity and an immunogenic gene signature were established in DIPG cell lines using clinically relevant LSD1 inhibitors. Pediatric HGG patient sequencing data demonstrated survival benefit of this LSD1-dependent gene signature. Pretreatment of DIPG with these inhibitors increased lysis by natural killer (NK) cells. Catalytic LSD1 inhibitors induced tumor regression and augmented NK cell infusion in vivo to reduce tumor burden. CIBERSORT analysis of patient data confirmed NK infiltration is beneficial to patient survival, while CD8 T cells are negatively prognostic. Catalytic LSD1 inhibitors are nonperturbing to NK cells, while scaffolding LSD1 inhibitors are toxic to NK cells and do not induce the gene signature in DIPG cells.

CONCLUSIONS

LSD1 inhibition using catalytic inhibitors is selectively cytotoxic and promotes an immune gene signature that increases NK cell killing in vitro and in vivo, representing a therapeutic opportunity for pHGG.

KEY POINTS

1. LSD1 inhibition using several clinically relevant compounds is selectively cytotoxic in DIPG and shows in vivo efficacy as a single agent.2. An LSD1-controlled gene signature predicts survival in pHGG patients and is seen in neural tissue from LSD1 inhibitor-treated mice.3. LSD1 inhibition enhances NK cell cytotoxicity against DIPG in vivo and in vitro with correlative genetic biomarkers.

Feasibility and early experience of a novel multidisciplinary alcohol-associated liver disease clinic

BACKGROUND

Alcohol cessation improves mortality in alcohol-associated liver disease (ALD), but access to treatment is limited. To address this gap, implementation and early feasibility and outcomes of a multidisciplinary ALD clinic are described.

METHODS

The clinic comprised a hepatologist, psychiatrist, psychologist, nurse, and social worker. Patients included those with alcohol-associated cirrhosis or acute alcoholic hepatitis who were not in the transplant evaluation process, who had less than 6 months' sobriety and willingness to engage in alcohol use treatment. Psychosocial metrics in addition to routine hepatic function labs were collected. Treatment plans were tailored based on patient preferences and needs after multidisciplinary discussion.

RESULTS

89 patients were referred from both inpatient and outpatient settings, with 51 seen during the initial year. 38 remained active in clinic (4 died, 6 discharged, 3 moved to transplant clinic). 55% were women, 88% were white, 61% had private insurance. 49% had alcoholic hepatitis. 71% were decompensated. 80% had severe alcohol use disorder (AUD) and 84% had at least 1 comorbid psychiatric or substance use disorder. 63% chose one-on-one AUD treatment, 57% were prescribed relapse prevention medications. Mean MELD-Na score improved from baseline of 14 (SD 6.6) to 11.3 at 6 months (p=0.01). Hospital utilization significantly declined when comparing 6 months before to 6 months after initial visit (emergency department visits: 0.51 to 0.20 per person-month; inpatient admission: 0.34 to 0.14 per person-month; (β= -0.89, 95% CI -1.18 to -0.60).

CONCLUSIONS

A multidisciplinary ALD clinic was feasible with encouraging early outcomes. Further research should explore ways to expand this model and increase clinic capacity.

Cigarette Smoke Exposure in Mice using a Whole-Body Inhalation System

Close to 14% of adults in the United States were reported to smoke cigarettes in 2018. The effects of cigarette smoke (CS) on lungs and cardiovascular diseases have been widely studied, however, the impact of CS in other tissues and organs such as blood and bone marrow remain incompletely defined. Finding the appropriate system to study the effects of CS in rodents can be prohibitively expensive and require the purchase of commercially available systems. Thus, we set out to build an affordable, reliable, and versatile system to study the pathologic effects of CS in mice. This whole-body inhalation exposure system (WBIS) set-up mimics the breathing and puffing of cigarettes by alternating exposure to CS and clean air. Here we show that this do-it-yourself (DIY) system induces airway inflammation and lung emphysema in mice after 4-months of cigarette smoke exposure. The effects of whole-body inhalation (WBI) of CS on hematopoietic stem and progenitor cells (HSPCs) in the bone marrow using this apparatus are also shown.

Scaffolding LSD1 Inhibitors Impair NK Cell Metabolism and Cytotoxic Function Through Depletion of Glutathione

Cell therapies such as chimeric-antigen receptor (CAR) T-cells and NK cells are cutting-edge methods for treating cancer and other diseases. There is high interest in optimizing drug treatment regimens to best work together with emerging cell therapies, such as targeting epigenetic enzymes to stimulate recognition of tumor cells by immune cells. Herein, we uncover new mechanisms of the histone demethylase LSD1, and various inhibitors targeting unique domains of LSD1, in the function of NK cells grown for cell therapy. Catalytic inhibitors (tranylcypromine and the structural derivatives GSK LSD1 and RN-1) can irreversibly block the demethylase activity of LSD1, while scaffolding inhibitors (SP-2509 and clinical successor SP-2577, also known as seclidemstat) disrupt epigenetic complexes that include LSD1. Relevant combinations of LSD1 inhibitors with cell therapy infusions and immune checkpoint blockade have shown efficacy in pre-clinical solid tumor models, reinforcing a need to understand how these drugs would impact T- and NK cells. We find that scaffolding LSD1 inhibitors potently reduce oxidative phosphorylation and glycolysis of NK cells, and higher doses induce mitochondrial reactive oxygen species and depletion of the antioxidant glutathione. These effects are unique to scaffolding inhibitors compared to catalytic, to NK cells compared to T-cells, and importantly, can fully ablate the lytic capacity of NK cells. Supplementation with biologically achievable levels of glutathione rescues NK cell cytolytic function but not NK cell metabolism. Our results suggest glutathione supplementation may reverse NK cell activity suppression in patients treated with seclidemstat.

Abstract A06: Impact of cigarette smoke exposure on acute myeloid leukemia progression

Cigarette smoke is known to cause lung cancer but is also associated with increased incidence of leukemia. Acute myeloid leukemia (AML) is the most lethal form of leukemia, and patients who are or were smokers have increased risk of developing AML and have worse prognosis. There is also an increased incidence of AML in children whose parents smoked either during or after the pregnancy. It is currently unknown how cigarette smoke exposure (CSE) may be impacting leukemic progression or treatment efficacy in AML. Cigarette smoking increases levels of reactive oxygen species (ROS) in the tissue of smokers, including peripheral blood samples. Oxidative stress can alter epigenetic signaling, including DNA methylation. Oxidation of methylated DNA and oxidative lesions on DNA can alter normal DNA methylation patterns. Smokers have altered DNA methylation that can be retained decades after the cessation of the habit, and these changes can be found in the blood cells of smokers. Cigarette smoke condensate (CSC) treatment has also been seen to epigenetically prime nontransformed human bronchial cells for malignant transformation. These occurrences have been seen in the context of lung cancer and lung damage, but studies into other tissue damage have largely been overlooked. Thus, we hypothesize that CSE impacts leukemic progression and treatment in AML through these mechanisms. We have developed a model to study the impact of CSE on AML in mice. NOD-SCID mice are smoke exposed for two weeks prior to being engrafted with luciferase-labeled human AML cells. The CSE is performed in the SCIREQ Cigarette Smoking Robot, with 3R4F research cigarettes 5 days/week. We include experimental arms of smoking cessation (who stop once evidence of leukemic engraftment is detected) and continued smoking, to model patients who either stop or continue smoking upon diagnosis of AML. Leukemic burden is quantified through bioluminescent imaging throughout the experiment. From these models, we have observed that two weeks of CSE is sufficient to significantly increase (p-value<0.0001) early leukemic burden as compared to non-smoke exposed mice, in FLT3-ITD AML-bearing mice. Spleen samples revealed trends of increased levels of superoxides in the CSE mice. Currently, immunohistochemistry is being performed on collected organs to detect oxidative stress markers. Additionally, mouse spleen DNA underwent reduced representative bisulfide sequencing; the levels of DNA methylation in the mouse host cells and in the leukemia are compared between our CSE groups. This is the first description of CSE promoting leukemia growth in mouse model, which will enable the study of mechanistic aspects. This may help define if unique treatment strategies are needed for these patients.

Citation Format: Yue Lu, Marcos Estecio, Marina Konopleva, Elias Jabbour, Joya Chandra, Mary Figueroa. Impact of cigarette smoke exposure on acute myeloid leukemia progression [abstract]. In: Proceedings of the AACR Special Conference on Environmental Carcinogenesis: Potential Pathway to Cancer Prevention; 2019 Jun 22-24; Charlotte, NC. Philadelphia (PA): AACR; Can Prev Res 2020;13(7 Suppl): Abstract nr A06.

Understanding gold toxicity in aerobically-grown Escherichia coli

Background

There is an emerging field to put into practice new strategies for developing molecules with antimicrobial properties. In this line, several metals and metalloids are currently being used for these purposes, although their cellular effect(s) or target(s) in a particular organism are still unknown. Here we aimed to investigate and analyze Au³⁺ toxicity through a combination of biochemical and molecular approaches.

Results

We found that Au³⁺ triggers a major oxidative unbalance in Escherichia coli, characterized by decreased intracellular thiol levels, increased superoxide concentration, as well as by an augmented production of the antioxidant enzymes superoxide dismutase and catalase. Because ROS production is, in some cases, associated with metal reduction and the concomitant generation of gold-containing nanostructures (AuNS), this possibility was evaluated in vivo and in vitro.

Conclusions

Au³⁺ is toxic for E. coli because it triggers an unbalance of the bacterium’s oxidative status. This was demonstrated by using oxidative stress dyes and antioxidant chemicals as well as gene reporters, RSH concentrations and AuNS generation.

A Standardized Donor Designation Ratio to Assess the Performance of Driver's License Agencies

Evaluating Department of Motor Vehicles (DMV) locations based on the percent of patrons who register as donors does not account for individual characteristics that may influence willingness to donate. We reviewed the driver's licenses of 2997 randomly selected patients at an urban medical system to obtain donor designation, age, gender, and DMV location and linked patient addresses with census tract data on race, ethnicity, income, and education. We then developed a Standardized Donor Designation Ratio (SDDR) (ie, the observed number of donors at each DMV divided by the expected number of donors based on patient demographic characteristics). Overall, 1355 (45%) patients were designated as donors. Donor designation was independently associated with younger age, female gender, nonblack race, and higher income. Across 18 DMVs, the proportion of patients who were donors ranged from 30% to 68% and SDDRs ranged from 0.82 to 1.17. Among the 6 facilities in the lowest tertile by SDDR, 3 were in the lowest tertile by percent donation. In conclusion, there is a great deal of variation across DMVs in rates of organ donor designation. SDDRs that adjust for DMV patron characteristics are distinct measures that may more accurately describe the performance of DMVs in promoting organ donation.

Abstract 3317: Autophagy protects ovarian cancer cells from olaparib-induced toxicity

Ovarian cancer (OC) is the most lethal gynecologic malignancy. Persistence of dormant, drug resistant cancer cells is one of the major factors that contribute to poor outcomes. The Poly (ADP) ribose polymerase (PARP) inhibitor, olaparib, has shown promising anti-cancer activity and has been approved by the FDA for the treatment of ovarian cancer with BRCA1/2 mutations. Olaparib targets DNA repair mechanisms within cancer cells and induces apoptosis. Both preclinical and clinical data indicate that efficacy of olaparib can be decreased by acquired resistance. One mechanism of resistance involves autophagy. Autophagy can degrade organelles and long-lived proteins to provide energy for cancer cells under nutrient poor conditions or in the presence of stress. The energy provided from autophagy is used to fuel the DNA repair process and metabolic needs in cancer cells. Autophagy can protect cancer cells from chemotherapy or can enhance the response to certain drugs. In this study, we have asked whether autophagy protects OC cells against the cytotoxic effects of olaparib or augments damage.

We first determined PARP activity using a modified PARP activity assay in different OC cell lines. Olaparib-induced autophagy was determined by punctate localization of GFP-LC3, conversion of LC3I to LC3II on protein blots and electron microscopy. To test whether autophagy contributes to the resistance of OC cells to olaparib, we determined the impact of autophagy inhibition on the sensitivity of OC cells to olaparib by either using the pharmacologic inhibitors chloroquine (CQ), LYS05 or short interfering RNA (siRNA) against ATG7. Upon investigation of a potential mechanism of olaparib-induced autophagy we evaluated the production of reactive oxygen species (ROS) and the expression of JNK, Ataxia-telangiectasia mutated (ATM), mTOR and p70S6K.

Inhibition of PARP by olaparib treatment, decreased PARP activity in a dose- dependent manner, leading to DNA damage judged by phosphorylation of γ-H2AX. Olaparib treatment decreased cell growth, caused cell cycle arrest and significantly enhanced apoptosis in 5 of 5 OC cell lines. Olaparib induced autophagy in 8 of 8 OC cell lines. Both pharmacologic and genetic inhibition of autophagy increased OC cells sensitivity to olaparib and induced apoptosis in 5 of 6 OC cell lines. Furthermore, flow cytometry and western blot analysis demonstrated that olaparib treatment increased ROS production and increased the phosphorylation of JNK and ATM while decreasing the phosphorylation of mTOR and p70S6K.

Taken together, our data described autophagy as a potential mechanism of olaparib resistance in OC that may depend upon the activation of ATM and JNK by ROS downregulating pmTOR and p70S6K. Combination of olaparib with CQ, LYS05 or other autophagy inhibitor may provide a novel strategy to increase the efficacy of olaparib in OC. Current studies are underway to test our hypothesis in vivo.

Citation Format: Janice M. Santiago-O'Farrill, Safia Essien, Mary Figueroa, Lan Pang, Ravi Amaravadi, Zhen Lu, Robert C. Bast. Autophagy protects ovarian cancer cells from olaparib-induced toxicity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3317. doi:10.1158/1538-7445.AM2017-3317

A phase II, multicentre trial of decitabine in higher-risk chronic myelomonocytic leukemia

Chronic myelomonocytic leukemia (CMML) is a complex clonal hematological disorder classified among myelodysplastic (MDS)/myeloproliferative neoplasms. Prognosis is poor and there is a lack of effective treatments. The hypomethylating agent decitabine has shown activity against MDS and elderly acute myeloid leukemia, but there is little data focusing specifically on its efficacy in CMML. In this prospective, phase 2 Italian study, CMML patients received intravenous decitabine 20 mg/m² per day on Days 1–5 of a 28-day treatment cycle. Response was evaluated after four and six cycles; patients responding at the end of six cycles could continue treatment with decitabine. Forty-three patients were enrolled; >50% were high-risk according to four CMML-specific scoring systems. In the intent-to-treat population (n=42), the overall response rate after six cycles was 47.6%, with seven complete responses (16.6%), eight marrow responses (19%), one partial response (2.4%) and four hematological improvements (9.5%). After a median follow-up of 51.5 months (range: 44.4–57.2), median overall survival was 17 months, with responders having a significantly longer survival than non-responders (P=0.02). Grade 3/4 anemia, neutropenia and thrombocytopenia occurred in 28.6%, 50% and 38% of patients, respectively. Decitabine appears to be an effective and well-tolerated treatment for patients with high-risk CMML.

Is Signature Size Associated With Organ Donor Designation on Driver's Licenses?

INTRODUCTION

Previous studies suggest that large signature size is associated with narcissistic characteristics. By contrast, organ donation is an indicator of altruism. Because altruism and narcissism may be viewed as opposites, we sought to determine if smaller signature size is associated with willingness to be an organ donor.

METHODS

Using a cross-sectional study design, we reviewed the health records of 571 randomly selected primary care patients at a large urban safety-net medical system to obtain their demographic and medical characteristics. We also examined driver's licenses that were scanned into electronic health records as part of the patient registration process. We measured signature sizes and obtained the organ donor designation from these driver's licenses.

RESULTS

Overall, 256 (45%) patients were designated as donors on their driver's licenses. Signature size averaged 113.3 mm(2) but varied greatly across patients (10th percentile 49.1 mm(2), 90th percentile 226.1 mm(2)). On multivariate analysis, donor designation was positively associated with age 18-34 years, non-black race, having private insurance, and not having any comorbid conditions. However, signature size was not associated with organ donor designation.

CONCLUSIONS

Signature size is not associated with verified organ donor designation. Further work is needed to understand the relationship between personality types and willingness to be an organ donor.

[Late onset lens particle glaucoma in Marfan syndrome]

CASE REPORT

A case is presented of an acute onset lens particle glaucoma originating from a crystalline lens spontaneously dislocated into the vitreous for more than 20 years in a patient diagnosed with Marfan syndrome.

DISCUSSION

Marfan syndrome is a connective tissue disorder with autosomal dominant inheritance caused by fibrillin gene mutation. Ectopia lentis is the predominant ocular abnormality and a major diagnostic criterion. An association between Marfan syndrome and glaucoma has also been demonstrated. The reported case is unusual in that a complete spontaneous lens dislocation to vitreous was present and progressed to secondary lens particle open angle glaucoma.

[Candidemia epidemiology in Córdoba Argentina. Surveillance study of five institutions]

The incidence rate of invasive infections due to Candida species has increased drastically in the last 20 years, causing a 40% mortality rate in hospitalized patients. In order to comprehend the epidemiology of Candida bloodstream infection, the study was carried out.

MATERIALS AND METHODS

A retrospective study was done based on microbiology laboratory reports from five terciary care hospitals from the city of Cordoba between January 2010 and August 2012.

RESULTS

158 patients had candidemia, the average age was 55,8 years, and 54% of patients were in the intensive care unit. Candida albicans (44%), Candida parapsilosis (22%) and Candida tropicalis (12%) were the main fungi isolated. Candida parapsilosis was commonly associated with catether infections.

CONCLUSIONS

The data from the city of Cordoba showed that C. albicans, C. parapsilosis y C. tropicalis were the more frequent species isolated from blood cultures. This is similar to what is seen in other series published from Argentina and Latinamerica. This study may have implications when it comes to deciding which empiric antifugal agent is best for the treatment of candidemia.

Effects of the cycle distribution on the performance of SBRs with aerobic granular biomass

The aerobic granular systems are mainly sequencing batch reactors where the biomass is submitted to feast-famine regimes to promote its aggregation in the form of granules. In these systems, different cycle distributions can be applied for the simultaneous removal of organic matter, nitrogen and phosphorus. In this work two strategies were followed in order to evaluate the effects of the cycle distribution. In the first experiment, the length of the operational cycle was decreased in order to maximize the treatment capacity and consequently the famine/feast ratio was also decreased. In the second experiment, an initial anoxic phase was implemented to improve nitrogen removal efficiency. The results obtained showed that to reduce the famine/feast ratio from 10 to 5 was possible by increasing the treated organic and nitrogen loading rates in the system to 33%, without affecting the removal efficiencies of organic matter (97%) and nitrogen (64%) and producing a slight detriment of the granules characteristics. On the other hand, the implementation of an anoxic phase of 30 min previous to the aerobic one with a pulse-fed mode increased the nitrogen removal of pig manure from 20 to 60%, while the cycle configuration comprising a continuous feeding simultaneous with an anoxic phase of 60 min did not enhance the nitrogen removal and even worsen the ammonia oxidation.

Long-distance distribution of genuine energy-time entanglement

Any practical realization of entanglement-based quantum communication must be intrinsically secure and able to span long distances avoiding the need of a straight line between the communicating parties. The violation of Bell's inequality offers a method for the certification of quantum links without knowing the inner workings of the devices. Energy-time entanglement quantum communication satisfies all these requirements. However, currently there is a fundamental obstacle with the standard configuration adopted: an intrinsic geometrical loophole that can be exploited to break the security of the communication, in addition to other loopholes. Here we show the first experimental Bell violation with energy-time entanglement distributed over 1 km of optical fibres that is free of this geometrical loophole. This is achieved by adopting a new experimental design, and by using an actively stabilized fibre-based long interferometer. Our results represent an important step towards long-distance secure quantum communication in optical fibres.

Aerobic granular SBR systems applied to the treatment of industrial effluents

Four lab scale sequencing batch reactors (SBRs) were operated to remove organic matter and nitrogen from four different industrial wastewaters. The biomass grew in the reactors in the form of aerobic granules characterized by good settling properties. The high biomass concentrations achieved inside the reactors allowed reducing the solids concentration in the effluent down to 0.2 g VSS L(-1). The organic loading rates (OLR) applied to reactors ranged between 0.7 and 5.0 g CODL(-1)d(-1) with removal efficiencies of 60-95%. The nitrogen loading rates (NLR) applied varied between 0.15 and 0.65 g NH(4)(+)-NL(-1)d(-1) with variable removal efficiencies in the four systems (between 15% and 76%).

Evaluation of natural zeolite as microorganism support medium in nitrifying batch reactors: influence of zeolite particle size

An evaluation of natural zeolite as a microorganism carrier in nitrifying reactors operated in batch mode was carried out. Specifically, the influence of zeolite particle sizes of 0.5, 1.0 and 2.0 mm in diameter on microorganism adherence to zeolite, ammonium adsorption capacity and the identification of microbial populations were assessed. The greatest amount of total biomass adhered was observed for a zeolite particle size of 1 mm (0.289 g) which was achieved on the 12th day of operation. The highest ammonium adsorption capacity was observed for a zeolite particle size of 0.5 mm, which was 64% and 31% higher than that observed for particle sizes of 1.0 and 2.0 mm, respectively. The maximum de-sorption values were also found for a zeolite particle size of 0.5 mm, although when equilibrium was reached the ammonium concentrations were similar to those observed for a zeolite particle size of 1.0 mm. It was also found that the experimental data on ammonium adsorption fitted very well to the Freundlich isotherm for the three particle sizes studied. Finally, the nitrifying reactors showed similar microbial populations independently of the particle size used as microorganism carrier. The dominant bacterial community was Gammaproteobacteria making up 80% of the total population found. Betaproteobacteria were also identified and made up 12% approx. of the total population. Ammonium Oxidant Betaproteobacteria and Nitrobacter were also detected.

Aerobic granulation in a mechanical stirred SBR: treatment of low organic loads

Aerobic granular sludge was produced in a sequencing batch reactor (SBR) characterized by a height to diameter ratio of 2.5 and the use of mechanical stirring. Compact and regular aerobic granules of up to 1.75 mm of average diameter were formed in the reactor with an organic loading rate of 1.75 kg COD/(m3 d). Settling properties of the obtained aggregates were: sludge volumetric index of 30-40 mL/g VSS and settling velocity higher than 8 m/h. The effects of different carbon to nitrogen ratios (TOC/N) in the feeding on the organic matter oxidation and nitrification process were studied. The concentration of organic matter in the feeding was stepwise reduced (from 190.0 to 37.5 mg TOC/L) and ammonium increased (from 25 to 50 mg NH4+ -N/L). TOC/N ratios of 7.50, 3.00, 1.50 and 0.75 g/g in the feeding were tested. The TOC removal percentage was around 80-95% during the whole operational period and the N removal percentages obtained in the reactor were up to 40%, however, physical properties of the granules were not maintained.

Treatment of high loaded swine slurry in an aerobic granular reactor

Aerobic granular sludge grown in a sequential batch reactor was proposed as an alternative to anaerobic processes for organic matter and nitrogen removal from swine slurry. Aerobic granulation was achieved with this wastewater after few days from start-up. On day 140 of operation, the granular properties were: 5 mm of average diameter, SVI of 32 mL (g VSS)(-1) and density around 55 g VSS (L(granule))(-1). Organic matter removal efficiencies up to 87% and nitrogen removal efficiencies up to 70% were achieved during the treatment of organic and nitrogen loading rates (OLR and NLR) of 4.4 kg COD m(-3) d(-1) and of 0.83 kg N m(-3) d(-1), respectively. However, nitrogen removal processes were negatively affected when applied OLR was 7.0 kg COD m(-3) d(-1) and NLR was 1.26 kg N m(-3) d(-1). The operational cycle of the reactor was modified by reducing the volumetric exchange ratio from 50 to 6% in order to be able to treat the raw slurry without dilution.

Poverty-associated risk factors for wheezing in the first year of life in Honduras and El Salvador

BACKGROUND

Risk factors for wheezing specifically during the first year of life have been studied in well-developed countries, but the information from developing countries is very scarce. There are no such studies focusing on factors derived from poverty. The aim of the present study was to determine if risk factors related to poverty are associated to wheezing during the first year of life in infants from Honduras and El Salvador.

METHODS

A survey, using a validated questionnaire, was carried out in the metropolitan area of San Pedro Sula (Honduras) and in La Libertad (El Salvador) in centres where infants attended for a scheduled vaccination shot or a healthy child visit at 12 months of age. Fieldworkers offered questionnaires to parents and helped the illiterate when necessary. The main outcome variable was wheezing during the first year of life, as reported by parents.

RESULTS

A total of 1047 infants in El Salvador and 780 in Honduras were included in the analysis. The prevalence of wheeze in the first year was higher in El Salvador (41.2%) than in Honduras (27.7%), as was recurrent wheezing defined as three or more episodes (18.4% vs. 11.7%). Wheezing and recurrent wheezing was associated to unpaved floor in the household (summary odds ratios for both countries 1.55, p=0.036 and 1.72, p=0.054 for any wheeze and recurrent wheezing, respectively); dust entering from streets (1.30, p=0.052 and 1.67, p=0.008); living in a heavily polluted area (1.33, p=0.037 and 1.52, p=0.033); and having mould stains on the household walls (1.36, p=0.072 and 1.76, p=0.007). Furthermore, marginal associations were found for additional person at home and use of kerosene as cooking fuel. University studies in the mother (0.34, p=0.046 and 0.32, p=0.022) and a professional occupation in the father (0.34, p=0.046 and 0.26, p=0.047) were associated to a lower risk.

CONCLUSIONS

The prevalence of wheezing and recurrent wheezing is notoriously high in El Salvador and Honduras. In those populations factors related to poverty are associated to a higher prevalence of wheezing and recurrent wheezing, whereas higher maternal education and paternal professional occupation behave as protective factors.

Treatment of anaerobic sludge digester effluents by the CANON process in an air pulsing SBR

The CANON (Completely Autotrophic Nitrogen removal Over Nitrite) process was successfully developed in an air pulsing reactor type SBR fed with the supernatant from an anaerobic sludge digester and operated at moderately low temperatures (18-24 degrees C). The SBR was started up as a nitrifying reactor, lowering progressively the dissolved oxygen concentration until reaching partial nitrification. Afterwards, an inoculation with sludge containing Anammox biomass was carried out. Nitrogen volumetric removal rates of 0.25 g NL(-1)d(-1) due to Anammox activity were measured 35 d after inoculation even though the inoculum constituted only 8% (w/w) of the biomass present in the reactor and it was poorly enriched in Anammox bacteria. The maximal nitrogen removal rate was of 0.45 g NL(-1)d(-1). By working at a dissolved oxygen concentration of 0.5 mg L(-1) in the bulk liquid, nitrogen removal percentages up to 85% were achieved. The reactor presented good biomass retention capacity allowing the accumulation of 4.5 g VSS L(-1). The biomass was composed by ammonia oxidizing bacteria (AOB) forming fluffy structures and granules with an average diameter of 1.6mm. These granules were composed by Anammox bacteria located in internal anoxic layers surrounded by an external aerobic layer where AOB were placed.

Population dynamics of nitrite oxidizers in nitrifying granules

The competition between Nitrospira and Nitrobacter species was analyzed in this work under conditions of excess of nitrite. A population of nitrite oxidizing bacteria (NOB) was developed from nitrifying biomass grown as granules with a mean diameter of 0.8 mm, whose feed was switched from ammonium to nitrite. The initial population distribution of the granules was: 60% Nitrosomonas and 30% Nitrospira and it evolved to 45% Nitrobacter and 40% Nitrospira measured 177 days after the change in the feeding. The disappearance of Nitrosomonas allowed the development of an important population of Nitrobacter demonstrating that these organisms, characterized by being r strategists NOB, are poor competitors when oxygen is the limiting substrate. Interestingly, the physical structure of the granules was not altered by the change of its microbial composition during the 220 days of operation.

Post-treatment of effluents from anaerobic digesters by the Anammox process

The application of the Anammox process was studied under two different approaches for the post-treatment of anaerobic digester supernatants: two independent units, the combined SHARON-Anammox system, performed in a chemostate and a SBR, respectively, and, a single unit system composed by an air pulsing SBR to carry out the CANON process. The technology based on the combination of the SHARON-Anammox process was used to treat the effluent of an anaerobic digester from a fish canning industry. The presence of organic matter in the influent caused fluctuations in the efficiency of the SHARON unit and an optimal nitrite to ammonium ratio was not achieved in this system to feed the Anammox reactor. Nevertheless an overall percentage of nitrogen removal of 40-80% was obtained when the Anammox reactor operated at nitrite limited conditions. In those periods when the effluent from the SHARON unit contained a NO2(-)-N/NH4(+)-N molar ratio higher than 1.3 the Anammox process lost its stability due to nitrite accumulation. The effluent from an anaerobic digester placed at a WWTP was treated by a CANON system operated at room temperature (20-24 degrees C). This system was developed from a nitrifying air pulsing reactor working at limiting dissolved oxygen conditions which was inoculated with Anammox biomass. A quick start-up of the system was observed and the reactor reached a nitrogen removal rate of 0.25 g N/(L d) 40 days after inoculation. The maximum nitrogen removal rate reached 0.5 g N/(L d). These results indicate the feasibility of the treatment of effluents from psychrophilic anaerobic digesters using the Anammox process.

Influence of gas flow-induced shear stress on the operation of the Anammox process in a SBR

The start up and performance of the Anammox process were tested in sequencing batch reactors with two different configurations: a bubble column (SBR-B) and a gas-lift reactor (SBR-G). Different off-gas upflow velocities were tested (3.53-12.3 cm min(-1)) in order to expose the biomass to different shear conditions and to study their effects on both efficiency and physical properties of the Anammox granular biomass. For the SBR-B the minimum gas upflow velocity needed to achieve biomass suspension inside the reactor was 12.3 cm min(-1). Such velocity made impossible the stable operation of the process. The fluidization of biomass for the SBR-G was reached at a gas upflow velocity of 3.52 cm min(-1). This system maintained an efficiency of nitrite removal around 98% at values up to 5.29 cm min(-1) but when the gas upflow velocity was increased from 5.29 to 9.70 cm min(-1) a significant decrease of the specific Anammox activity of the biomass from 0.35 to 0.05 g Ng(-1) VSS d(-1) was measured. The system lost 85% of its nitrogen removal efficiency which was not restored in spite of returning the gas upflow velocity to its initial value.

Treatment of saline wastewater in SBR aerobic granular reactors

Fish canning effluents characterized by their salt content, up to 30 g NaCl/L, were treated, previously diluted to desired concentration, in a SBR where aerobic granular sludge was produced. The formation of mature aerobic granules occurred after 75 days of operation with 3.4 mm of diameter, SVI of 30 mL/g VSS and density around 60 g VSS/L-granule. Treated organic loading rates were up to 1.72 kg COD/(m3.d) with fully organic matter depletion. Ammonia nitrogen was removed via nitrification-denitrification up to 40% when nitrogen loading rates were of 0.18 kg N/(m3.d). The presence of salt in the treated effluent did not cause a detrimental effect on the operation of the reactor once the aerobic granules were formed.

A double-blind placebo controlled trial of etanercept in patients with giant cell arteritis and corticosteroid side effects

OBJECTIVE

Open label studies have suggested that tumour necrosis factor (TNF) antagonists led to sustained improvement and corticosteroid sparing effect in patients with giant cell arteritis (GCA). To confirm these observations, we conducted a randomised, double-blind, placebo controlled trial with etanercept in patients with biopsy-proven GCA with side effects secondary to corticosteroids.

METHODS

We randomly assigned patients with GCA to receive etanercept (n = 8) or placebo (n = 9) over 1 year together with corticosteroids that were reduced according to a predefined schedule. The primary outcome was the ability to withdraw the corticosteroid therapy and control the disease activity at 12 months.

RESULTS

Baseline characteristics were similar in the two groups, although patients in the etanercept group showed higher levels of basal glycaemia (p = 0.02) and a higher erythrocyte sedimentation rate (ESR) (p = 0.01). After 12 months, 50% of the patients in the etanercept group and 22.2% in the placebo group were able to control the disease without corticosteroid therapy (p value not significant). Patients in the etanercept group had a significant lower dose of accumulated prednisone during the first year of treatment (p = 0.03). There were no differences in the number and type of adverse events.

CONCLUSION

The limited number of patients included in this study does not allow us to draw definitive conclusions. Etanercept therapy was well tolerated in this aged population. The therapeutic role of etanercept in patients with GCA should be evaluated in studies with a larger number of patients.

[Colostomy morbidity in children with anorectal malformations (ARM)]

OBJECTIVE

To describe the incidence and type of complications presented in the patients with ARM treated with a colostomy.

MATERIAL AND METHODS

The patients data with diagnostic of ARM and colostomy beetween 1994 and 2005 were revised.

RESULTS

The colostomy was carried out in other centers in 185 patients (75.2%) and in our institution in 61 (24.8%). Two hundred eleven (85.8%) had a sigmoid colostomy. Only 124 patients had a diverting colostomy. Sigmoid colon was erroneously used as transverse in 2 cases. The space among the ostomies was very scarce in 10 and excessive in 5. The colostomy complications were retraction in 7, prolapse in 7, closure of the distal opening in 5, proximal stenosis in 3, ostomy necrosis in 1 and the paraostomal hernia in 2. Complications related to the colostomy closure were intestinal occlusion in 1, abscess of abdominal wall in 1 and incisional hernia in 2.

CONCLUSIONS

The colostomy morbidity in patients with ARM is flashy. This procedure should not be considered a procedure of little complexity by the implications that has in the treatment of the patients with ARM.

[Ladd laparoscopic procedure in the neonate]

The treatment of the intestinal malrotation with or without midgut volvulus with the Ladd procedure for laparoscopic way has been proposed by several authors since 1995. We carry out this treatment in a patient of 15 days old with intestinal malrotation and midgut volvulus. After clinical and radiologic diagnosis, the procedure consisted in the careful counterclock reduction of the volvulus, division of the Ladd's bands, incision of the common mesentery and appendectomy. The jejunum and ileum was positioned on the rigth and the colon on the left in the abdominal cavity. The postoperative evolution was appropiate. We recommend the laparoscopic Ladd's procedure like an alternative in the patients with midgut volvulus that fulfill minimum approaches during the preoperative study that allow to carry out the surgery with security.