Search Results (20)

Background: Ropeginterferon alfa-2b (Ropeg-IFNa) is increasingly used in myeloproliferative neoplasms (MPN), particularly polycythemia vera, but real-world data across subtypes are limited. We evaluated clinical and molecular responses to Ropeg-IFNa in routine practice. Methods: We retrospectively analyzed 20 JAK2^V617F-positive MPN patients treated at a tertiary center. Baseline features, dosing, treatment line, hematologic responses, adverse events, and serial JAK2^V617F variant allele frequency (VAF) were extracted from records. Results: Median age at initiation was 53 years; 55% were ELN high-risk. Ropeg-IFNa was started first-line or after peginterferon alfa-2a, hydroxyurea, or a tapered JAK2 inhibitor. Mean treatment duration was 14 ± 11 months at 195 ± 143 µg Q2W. Hematologic control increased from 45% at the start to 60% at the last follow-up. Among patients with serial molecular monitoring (n = 11), median JAK2^V617F VAF declined from 21.2 to 12.7%. Ropeg-IFNa was generally well tolerated; adverse effects were mostly manageable, although 3/20 (15%) discontinued due to side effects, including mood disturbances, while others continued with supportive care and dose adjustments. Conclusions: In this single-center cohort, Ropeg-IFNa was tolerable and associated with improved hematologic control and modest VAF reductions, supporting its use in multi-subtype MPN cohorts. These findings underscore the value of longitudinal driver-mutation monitoring during therapy. Full article

Standard systemic treatment has not been established for refractory meningioma. This retrospective study aimed to identify prognostic factors for overall survival and document outcomes of systemic therapies. We reviewed patients with meningioma followed at CHUM hospital between 2006 and 2022. Only patients with progression after first-line treatment were included. Among 750 patients, 107 (14%) experienced progression after first-line treatment. They were divided into two groups: Group 1 (n = 69, 64%) received salvage local treatments, and Group 2 (n = 38, 36%) received additional salvage systemic treatments. The median follow-up time from diagnosis was 7.5 years. 10-year OS was 88.3% (Group 1) vs. 67.2% (Group 2) (p = 0.009). Mean survival after stopping systemic treatment was 8.94 months. Key prognostic factors for poorer survival included age ≥ 65 (HR = 2.82; p = 0.009), WHO grade 2 or 3 (HR = 4.25; p = 0.004), and progression after second-line treatment (HR = 4.77; p = 0.004). Bevacizumab was associated with a mPFS of 12 months and 1-year OS of 64,6%, whereas non-Bevacizumab treatments—including Hydroxyurea, Somatostatin, and Sunitinib—were associated with a mPFS of 7 months and 1-year OS of 52,6%. This study highlights the fatal nature of recurrent meningiomas and the urgent need for systemic treatments that can improve their survival. Full article

Background: Sensors for continuous glucose monitoring (CGM) are now commonly used by people with type 1 and type 2 diabetes. However, the response of these devices to potentially interfering nutritional, pharmaceutical, or endogenous substances is barely explored. We previously developed an in vitro test method for continuous and dynamic CGM interference testing and herein explore the sensitivity of the Abbott Libre2 (L2) and Dexcom G6 (G6) sensors to a panel of 68 individual substances. Methods: In each interference experiment, L2 and G6 sensors were exposed in triplicate to substance gradients from zero to supraphysiological concentrations at a stable glucose concentration of 200 mg/dL. YSI Stat 2300 Plus was used as the glucose reference method. Interference was presumed if the CGM sensors showed a mean bias of at least ±10% from baseline with a tested substance at any given substance concentration. Results: Both L2 and G6 sensors showed interference with the following substances: dithiothreitol (maximal bias from baseline: L2/G6: +46%/−18%), galactose (>+100%/+17%), mannose (>+100%/+20%), and N-acetyl-cysteine (+11%/+18%). The following substances were found to interfere with L2 sensors only: ascorbic acid (+48%), ibuprofen (+14%), icodextrin (+10%), methyldopa (+16%), red wine (+12%), and xylose (>+100%). On the other hand, the following substances were found to interfere with G6 sensors only: acetaminophen (>+100%), ethyl alcohol (+12%), gentisic acid (+18%), hydroxyurea (>+100%), l-cysteine (−25%), l-Dopa (+11%), and uric acid (+33%). Additionally, G6 sensors could subsequently not be calibrated for use after exposure to dithiothreitol, gentisic acid, l-cysteine, and mesalazine (sensor fouling). Conclusions: Our standardized dynamic interference testing protocol identified several nutritional, pharmaceutical and endogenous substances that substantially influenced L2 and G6 sensor signals. Clinical trials are now necessary to investigate whether our findings are of relevance during routine care. Full article

Background/Objective: Cobalamin (B₁₂) deficiency is reported in 18% of adults with sickle cell disease (SCD) and only 10% without SCD; limited data are available on children. Diagnosing B₁₂ deficiency is challenging given the lack of an established gold standard method of assessment and the unique renal features of SCD. B₁₂ metabolism can be impacted by the clinical use of nitrous oxide gas (N₂O), which is a standard therapy for SCD pain in some European countries. In response to emerging reports of neurologic sequalae in patients with SCD receiving N₂O, we evaluated the prevalence of B₁₂ deficiency in children with SCD pain. Methods: Secondary analysis of prospective blood and urine samples in children aged 3–21 hospitalized with SCD pain. B₁₂ deficiency was defined as plasma methylmalonic acid (MMA) > 592 nmol/L or urine MMA/creatinine ≥ 2.2 mmol/mol. Results: Ninety-four children (13 ± 4 years, 54% female, 68% hemoglobin-SS, and 72% on hydroxyurea) were assessed. Further, 53% (50/94) had B₁₂ deficiency diagnosed by either urine, plasma, or both; 27% (25/94) were deficient based on urine; 39% (37/94) were deficient by plasma; and 13% (12/94) were deficient by both plasma and urine. Plasma MMA and urine MMA/creatinine did not correlate with hemoglobin or mean corpuscular volume. Conclusions: B₁₂ deficiency was common in children with SCD. The absence of a gold standard for diagnosing B₁₂ deficiency compounded with the reliability issues of testing modalities make it impractical to determine whether this is an over- or under-estimation of the true prevalence. Future studies to better understand the dynamics of B₁₂ metabolism during acute and steady states in SCD are warranted and could elucidate the influence of acute SCD pain on these biomarkers. Full article

Evaluation of pharmacokinetic properties is a significant step at the early stages of drug development. In this study, an in vitro evaluation of the pharmacokinetic properties of five newly synthesized compounds was performed. These compounds belong to N-hydroxyurea and hydroxamic acid derivatives and analogs of NSAIDs indomethacin, flurbiprofen, diclofenac, ibuprofen, and naproxen (compounds 1, 2, 3, 11, and 12, respectively) with dual COX-2 and 5-LOX inhibitory activity. Two in vitro methods (biopartitioning micellar chromatography (BMC) and PAMPA) were used to evaluate passive gastrointestinal absorption, while high-performance affinity chromatography (HPAC) and differential pulse voltammetry (DPV) were used to evaluate binding to human serum albumin (HSA). The introduction of N-hydroxyurea and hydroxamic acid groups into the structure of NSAIDs decreases both expected passive gastrointestinal absorption (BMC k values were from 3.02 to 9.50, while for NSAIDs were from 5.29 to 13.36; PAMPA –logPe values were between 3.81 and 4.76, while for NSAIDs were ≤3.46) and HSA binding (HPAC logk values were from 2.03 to 9.54, while for NSAIDs were ≥11.03; DPV peak potential shifts were between 7 and 34, while for NSAIDs were ≥54). Structural modifications of all tested compounds that increase lipophilicity could be considered to enhance their passive gastrointestinal absorption. Considering lower expected HSA binding and higher lipophilicity of tested compounds compared to corresponding NSAIDs, it can be expected that the volume of distribution of compounds 1, 2, 3, 11, and 12 will be higher. Reduced HSA binding may also decrease interactions with other drugs in comparison to corresponding NSAIDs. All tested compounds showed significant microsomal instability (25.07–58.44% decrease in concentration) in comparison to indomethacin (14.47%) and diclofenac (20.99%). Full article

N-Hydroxyurea (HU) is an important chemotherapeutic agent used as a first-line treatment in conditions such as sickle cell disease and $\beta$-thalassemia, among others. To date, its properties as a hydrated molecule in the blood plasma or cytoplasm are dramatically understudied, although they may be crucial to the binding of HU to the radical catalytic site of ribonucleotide reductase, its molecular target. The purpose of this work is the comprehensive exploration of HU hydration. The topic is studied using ab initio molecular dynamic (AIMD) simulations that apply a first principles representation of the electron density of the system. This allows for the calculation of infrared spectra, which may be decomposed spatially to better capture the spectral signatures of solute–solvent interactions. The studied molecule is found to be strongly hydrated and tightly bound to the first shell water molecules. The analysis of the distance-dependent spectra of HU shows that the E and Z conformers spectrally affect, on average, 3.4 and 2.5 of the closest H₂O molecules, respectively, in spheres of radii of 3.7 Å and 3.5 Å, respectively. The distance-dependent spectra corresponding to these cutoff radii show increased absorbance in the red-shifted part of the water OH stretching vibration band, indicating local enhancement of the solvent’s hydrogen bond network. The radially resolved IR spectra also demonstrate that HU effortlessly incorporates into the hydrogen bond network of water and has an enhancing effect on this network. Metadynamics simulations based on AIMD methodology provide a picture of the conformational equilibria of HU in solution. Contrary to previous investigations of an isolated HU molecule in the gas phase, the Z conformer of HU is found here to be more stable by 17.4 kJ·mol⁻¹ than the E conformer, pointing at the crucial role that hydration plays in determining the conformational stability of solutes. The potential energy surface for the OH group rotation in HU indicates that there is no intramolecular hydrogen bond in Z-HU in water, in stark contrast to the isolated solute in the gas phase. Instead, the preferred orientation of the hydroxyl group is perpendicular to the molecular plane of the solute. In view of the known chaotropic effect of urea and its N-alkyl-substituted derivatives, N-hydroxyurea emerges as a unique urea derivative that exhibits a kosmotropic ordering of nearby water. This property may be of crucial importance for its binding to the catalytic site of ribonucleotide reductase with a concomitant displacement of a water molecule. Full article

Phosphatidylcholine-specific phospholipase C (PC-PLC) is an enzyme that catalyzes the formation of the important secondary messengers phosphocholine and diacylglycerol (DAG) from phosphatidylcholine. Although PC-PLC has been linked to the progression of many pathological conditions, including cancer, atherosclerosis, inflammation and neuronal cell death, studies of PC-PLC on the protein level have been somewhat neglected with relatively scarce data. To date, the human gene expressing PC-PLC has not yet been found, and the only protein structure of PC-PLC that has been solved was from Bacillus cereus (PC-PLC_Bc). Nonetheless, there is evidence for PC-PLC activity as a human functional equivalent of its prokaryotic counterpart. Additionally, inhibitors of PC-PLC_Bc have been developed as potential therapeutic agents. The most notable classes include 2-aminohydroxamic acids, xanthates, N,N′-hydroxyureas, phospholipid analogues, 1,4-oxazepines, pyrido[3,4-b]indoles, morpholinobenzoic acids and univalent ions. However, many medicinal chemistry studies lack evidence for their cellular and in vivo effects, which hampers the progression of the inhibitors towards the clinic. This review outlines the pathological implications of PC-PLC and highlights current progress and future challenges in the development of PC-PLC inhibitors from the literature. Full article

Various dual inhibitors of COX-2 and 5-LOX enzymes have been developed so far in order to obtain more effective and safer anti-inflammatory drugs. The aim of this study was to design and synthesize new dual COX-2 and 5-LOX inhibitors, and to evaluate their enzyme inhibition potential and redox properties. Thirteen compounds (1–13) were designed taking into account structural requirements for dual COX-2 and 5-LOX inhibition and antioxidant activity, synthesized, and structurally characterized. These compounds can be classified as N-hydroxyurea derivatives (1, 2 and 3), 3,5-di-tert-butylphenol derivatives (4, 5, 6, 7 and 13), urea derivatives (8, 9 and 10) and “type B hydroxamic acids” (11 and 12). COX-1, COX-2 and 5-LOX inhibitory activities were evaluated using fluorometric inhibitor screening kits. The evaluation of the redox activity of newly synthesized compounds was performed in vitro in the human serum pool using redox status tests. The prooxidative score, the antioxidative score and the oxy-score were calculated. Seven out of thirteen synthesized compounds (1, 2, 3, 5, 6, 11 and 12) proved to be dual COX-2 and 5-LOX inhibitors. These compounds expressed good COX-2/COX-1 selectivity. Moreover, dual inhibitors 1, 3, 5, 11 and 12 showed good antioxidant properties. Full article

Soil bacteria can produce urease, which catalyzes the hydrolysis of urea to ammonia (NH₃) and carbamate. A variety of urease inhibitors have been proposed to reduce NH₃ volatilization by interfering with the urease activity. We report a quantum mechanics/molecular mechanics molecular dynamics (QM/MM MD) study on the mechanism employed for the inhibition of urease by three representative competitive inhibitors; namely, acetohydroxamic acid (AHA), hydroxyurea (HU), and N-(n-butyl)phosphorictriamide (NBPTO). The possible connections between the structural and thermodynamical properties and the experimentally observed inhibition efficiency were evaluated and characterized. We demonstrate that the binding affinity decreases in the order NBPTO >> AHA > HU in terms of the computed activation and reaction free energies. This trend also indicates that NBPTO shows the highest inhibitory activity and the lowest IC₅₀ value of 2.1 nM, followed by AHA (42 μM) and HU (100 μM). It was also found that the X=O moiety (X = carbon or phosphorous) plays a crucial role in the inhibitor binding process. These findings not only elucidate why the potent urease inhibitors are effective but also have implications for the design of new inhibitors. Full article

Sickle cell disease (SCD) refers to a group of inherited hemoglobin disorders in which sickle red blood cells display altered deformability, leading to a significant burden of acute and chronic complications, such as vaso-occlusive pain crises (VOCs). Hydroxyurea is a major therapeutic agent in adult and pediatric sickle cell patients. This treatment is an alternative to transfusion in some complications. Indeed, it increases hemoglobin F and has an action on the endothelial adhesion of red blood cells, leukocytes, and platelets. Although the safety profile of hydroxyurea (HU) in patients with sickle cell disease has been well established, the existing literature on HU exposure during pregnancy is limited and incomplete. Pregnancy in women with SCD has been identified as a high risk for the mother and fetus due to the increased incidence of maternal and non-fetal complications in various studies and reports. For women on hydroxyurea at the time of pregnancy, transfusion therapy should probably be initiated after pregnancy. In addition, there is still a significant lack of knowledge about the incidence of pregnancy, fetal and maternal outcomes, and management of pregnant women with SCD, making it difficult to advise women or clinicians on outcomes and best practices. Therefore, the objective of this study was to describe pregnancy outcomes (n = 128) reported in the noninterventional European Sickle Cell Disease COhoRT-HydroxyUrea (ES-CORT-HU) study. We believe that our results are important and relevant enough to be shared with the scientific community. Full article

β-thalassemia is one of the most common monogenic disorders and a life-threatening health issue in children. A cost-effective and safe therapeutic approach to treat this disease is to reactivate the γ-globin gene for fetal hemoglobin (HbF) production that has been silenced during infancy. Hydroxyurea (HU) is the only FDA approved HbF inducer. However, its cytotoxicity and inability to respond significantly in all patients pose a need for an HbF inducer with better efficacy. The study describes the serum metabolic alteration in β-YAC transgenic mice treated with Tenofovir disoproxil fumarate (TDF) (n = 5), a newly identified HbF inducer, and compared to the mice groups treated with HU (n = 5) and untreated control (n = 5) using gas chromatography-mass spectrometry. Various univariate and multivariate statistical analyses were performed to identify discriminant metabolites that altered the biological pathways encompassing galactose metabolism, lactose degradation, and inositol. Furthermore, the decreased concentrations of L-fucose and geraniol in TDF-treated mice help in recovering towards normal, decreasing oxidative stress even much better than the HU-treated mice. The proposed study suggested that TDF can reduce the deficiency of blood required for β-thalassemia and can be used for the preclinical study at phase I/II for fetal hemoglobin production. Full article

The search is ongoing for new anticancer therapeutics that would overcome resistance to chemotherapy. This includes chronic myeloid leukemia, particularly suitable for the studies of novel anticancer compounds due to its homogenous and well-known genetic background. Here we show anticancer efficacy of novel dicarboximide denoted BK124.1 (C₃₁H₃₇ClN₂O₄) in a mouse CML xenograft model and in vitro in two types of chemoresistant CML cells: MDR1 blasts and in CD34⁺ patients’ stem cells (N = 8) using immunoblotting and flow cytometry. Intraperitoneal administration of BK124.1 showed anti-CML efficacy in the xenograft mouse model (N = 6) comparable to the commonly used imatinib and hydroxyurea. In K562 blasts, BK124.1 decreased the protein levels of BCR-ABL1 kinase and its downstream effectors, resulting in G2/M cell cycle arrest and apoptosis associated with FOXO3a/p21^waf1/cip1 upregulation in the nucleus. Additionally, BK124.1 evoked massive apoptosis in multidrug resistant K562-MDR1 cells (IC₅₀ = 2.16 μM), in CD34⁺ cells from CML patients (IC₅₀ = 1.5 µM), and in the CD34⁺/CD38⁻ subpopulation consisting of rare, drug-resistant cancer initiating stem cells. Given the advantages of BK124.1 as a potential chemotherapeutic and its unique ability to overcome BCR-ABL1 dependent and independent multidrug resistance mechanisms, future development of BK124.1 could offer a cure for CML and other cancers resistant to present drugs. Full article

Introduction: Studies assessing immune responses following Pfizer-BioNTech BNT162b2 mRNA COVID-19 (Pfizer) and ChAdOx1 nCoV-19 AZD1222 (AstraZeneca) vaccines in patients with hemoglobinopathy are non-existent in the literature despite being thought at high risk of infection. Methods: Prospectively, we collected serum from patients with hemoglobinopathies at least 14 days post vaccine and measured neutralizing antibodies (nAb) in addition to binding antibodies using in-house assays. Results: All 66 participants mounted a significant binding antibody response (100%), but nAbs were detected in (56/66) post-vaccine with a rate of 84.5%. Age, gender, vaccine type, spleen status, hydroxyurea use, and hyperferritinemia did not affect the rate significantly. While 23/32 (71.8%) patients receiving only one dose of the vaccine were able to mount a positive response, 33/34 (97.05%) of those who had two doses of any vaccine type had a significant nAbs response. Patients who had anti-nucleocapsid (N), signifying asymptomatic infection in the past, were able to produce nAbs (31/31). No nAbs were detected in 10/35 (28.5%) patients with no anti-N antibodies. Conclusion: Our results provide supportive data when advising patients with hemoglobinopathy to receive COVID-19 vaccines and ensure booster doses are available for better immunity. Whenever available, measurement of nAb is recommended. Full article

Hydroxyurea (HU) causes nitric oxide (NO) bioactivation, acting as both a NO donor and a stimulator of NO synthase (NOS). To examine whether HU effects are NO mediated by chemical degradation or enzymatic induction, we studied human and mouse erythroid cells during proliferation, apoptosis, and differentiation. The HU and NO donor demonstrated persisted versus temporary inhibition of erythroid cell growth during differentiation, as observed by γ- and β-globin gene expression. HU decreased the percentage of erythroleukemic K562 cells in the G2/M phase that was reversed by N-nitro l-arginine methyl ester hydrochloride (L-NAME). Besides activation of endothelial NOS, HU significantly increased apoptosis of K562 cells, again demonstrating NOS dependence. Administration of HU to mice significantly inhibited colony-forming unit-erythroid (CFU-E), mediated by NOS. Moreover, burst-forming-units-erythroid (BFU-E) and CFU-E ex vivo growth was inhibited by the administration of nitrate or nitrite to mice. Chronic in vivo NOS inhibition with L-NAME protected the bone marrow cellularity despite HU treatment of mice. NO metabolites and HU reduced the frequency of NOS-positive cells from CFU-E and BFU-E colonies that was reverted by NOS inhibition. HU regulation of the G2/M phase, apoptosis, differentiation, cellularity, and NOS immunoreactive cells was NOS dependent. Inhalation of NO therapy as well as strategies to increase endogenous NO production could replace or enhance HU activity. Full article

Hydroxyurea, an oral medication with important clinical benefits in the treatment of sickle cell anemia, can be accurately determined in plasma with a transition metal dichalcogenide-based electrochemical sensor. We used a two-dimensional molybdenum sulfide material (MoS₂) selectively electrodeposited on a polycrystalline gold electrode via tailored waveform polarization in the gold electrical double layer formation region. The electro-activity of the modified electrode depends on the electrical waveform parameters used to electro-deposit MoS₂. The concomitant oxidation of the MoS₂ material during its electrodeposition allows for the tuning of the sensor’s specificity. Chemometrics, utilizing mathematical procedures such as principal component analysis and multivariable partial least square regression, were used to process the electrochemical data generated at the bare and the modified electrodes, thus allowing the hydroxyurea concentrations to be predicted in human plasma. A limit-of-detection of 22 nM and a sensitivity of 37 nA cm⁻² µM⁻¹ were found to be suitable for pharmaceutical and clinical applications. Full article