Mutations in five canonical Ras pathway genes (NF1, NRAS, KRAS, PTPN11 and CBL) are detected in nearly 90% of patients with juvenile myelomonocytic leukemia (JMML), a frequently fatal malignant neoplasm of early childhood. In this report, we describe seven patients diagnosed with SH2B3-mutated JMML, including five patients who were found to have initiating, loss-of-function mutations in the gene. SH2B3 encodes the adaptor protein LNK, a negative regulator of normal hematopoiesis upstream of the Ras pathway.
View Article and Find Full Text PDFPediatr Blood Cancer
February 2024
Hydroxyurea is highly effective in sickle cell disease, but it is still underutilized. Reports of hydroxyurea utilization largely use Medicaid data, and socioeconomics is often cited as a barrier. To address whether patient demographics influenced the high hydroxyurea usage rate recently reported for the pediatric sickle cell program of Northern Virginia, analysis of data from 2011 to 2021 revealed no statistical difference in hydroxyurea usage rate between Medicaid and non-Medicaid, African American and African, or age less than 13 and age greater than or equal to 13 years cohorts, demonstrating that hydroxyurea can be successfully implemented across demographic groups.
View Article and Find Full Text PDFBackground: Individuals with sickle cell anemia (SCA) exhibit decreased exercise capacity. Anemia limits oxygen-carrying capacity and affects cardiopulmonary fitness. The drug voxelotor raises hemoglobin in SCA.
View Article and Find Full Text PDFHydroxyurea (HU) has proven benefit in sickle cell anemia (SCA), but HU is still underutilized. The Pediatric Sickle Cell Program of Northern Virginia prescribes HU regardless of symptoms to all SCA patients age ≥ 9 months and prospectively tracks outcomes. HU is dosed to maximum tolerated dosing (MTD), targeting 30% Hgb F.
View Article and Find Full Text PDFRecipients of anti-CD19 targeted therapies such as chimeric antigen receptor (CAR)-T cell are considered at high risk for complicated Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV-2) infection due to prolonged B cell aplasia and immunosuppression. These patients represent a unique cohort and so far, immune responses to SARS-CoV-2 have not been well characterized in this setting. We report a pediatric patient with B-cell acute lymphoblastic leukemia (B-ALL) who had asymptomatic SARS-CoV-2 infection while receiving blinatumomab, followed by lymphodepletion (LD) and tisagenlecleucel, a CD19 targeting CAR-T therapy.
View Article and Find Full Text PDFBackground: Alcohol intoxication produces ataxia by affecting the cerebellum, which coordinates movements. Fragile X mental retardation (FMR) protein is a complex regulator of RNA and synaptic plasticity implicated in fragile X-associated tremor/ataxia syndrome, which features ataxia and increased Fmr1 mRNA expression resulting from epigenetic dysregulation of FMRP. We recently demonstrated that acute ethanol-induced ataxia is associated with increased cerebellar Fmr1 gene expression via histone modifications in rats, but it is unknown whether similar behavioral and molecular changes occur following chronic ethanol exposure.
View Article and Find Full Text PDFAlcohol consumption is mediated by several important neuromodulatory systems, including the endocannabinoid and neuropeptide Y (NPY) systems in the limbic brain circuitry. However, molecular mechanisms through which cannabinoid-1 (CB1) receptors regulate alcohol consumption are still unclear. Here, we investigated the role of the CB1 receptor-mediated downstream regulation of NPY via epigenetic mechanisms in the amygdala.
View Article and Find Full Text PDFCurr Pathobiol Rep
September 2020
Purpose Of Review: Chronic alcohol use is a worldwide problem with multifaceted consequences including multiplying medical costs and sequelae, societal effects like drunk driving and assault, and lost economic productivity. These large-scale outcomes are driven by the consumption of ethanol, a small permeable molecule that has myriad effects in the human body, particularly in the liver and brain. In this review, we have summarized effects of acute and chronic alcohol consumption on epigenetic mechanisms that may drive pathobiology of Alcohol Use Disorder (AUD) while identifying areas of need for future research.
View Article and Find Full Text PDFBackground: Hydroxyurea (HU) increases fetal hemoglobin (HgbF) and ameliorates sickle cell disease (SCD) symptoms. Studies have demonstrated the safety and efficacy of HU in infants and children. Initiation of HU in infancy for children with SCD needs to be implemented in community practice.
View Article and Find Full Text PDFBackground: The cerebellum is fundamental for motor coordination and therefore crucial in ethanol (EtOH)-induced ataxia. EtOH contributes to cerebellar pathophysiology. Fragile-X mental retardation protein (FMRP) is a complex regulator of RNA and synaptic plasticity implicated in fragile-X tremor and ataxia syndrome, a phenotype featuring increased Fmr1 mRNA expression.
View Article and Find Full Text PDFAlcohol addiction leads to increased choice of alcohol over healthy rewards. We established an exclusive choice procedure in which ~15% of outbred rats chose alcohol over a high-value reward. These animals displayed addiction-like traits, including high motivation to obtain alcohol and pursuit of this drug despite adverse consequences.
View Article and Find Full Text PDFBackground: The neutropenic diet (ND) is prescribed to avoid introduction of bacteria into a host's gastrointestinal tract and reduce infection. Due to a lack of evidence to support the ND, there continues to be debate among pediatric oncologists regarding its usefulness. This prospective randomized controlled trial evaluated the difference in neutropenic infection rates in pediatric oncology patients randomized to Food and Drug Administration approved food safety guidelines (FSGs) versus the ND plus FSGs during one cycle of chemotherapy.
View Article and Find Full Text PDFGABAergic signaling is involved in modulating the reinforcing properties of alcohol, and GABA receptors have been proposed as a potential target for clinical treatment of alcoholism. The orthosteric GABA receptor agonist baclofen has been shown to suppress operant self-administration of alcohol in animals and alcohol use in alcohol-dependent patients, but its utility is limited by a narrow therapeutic index. We tested the effects of ADX71441, a novel GABA receptor positive allosteric modulator, on alcohol-related behaviors in rats.
View Article and Find Full Text PDFOperant oral self-administration methods are commonly used to study the reinforcing properties of ethanol in animals. However, the standard methods require saccharin/sucrose fading, water deprivation and/or extended training to initiate operant responding in rats. This paper describes a novel and efficient method to quickly initiate operant responding for ethanol that is convenient for experimenters and does not require water deprivation or saccharin/sucrose fading, thus eliminating the potential confound of using sweeteners in ethanol operant self-administration studies.
View Article and Find Full Text PDFFolic acid (FA) is commonly prescribed for patients with sickle cell anemia, but evidence for the efficacy of this practice is lacking. We stopped FA supplementation and measured red blood cell folate levels after discontinuation of FA in 72 patients with clinically severe forms of sickle cell disease. We compared hemoglobin and reticulocyte counts before and after FA discontinuation in 51 of those patients, the majority of whom were on hydroxyurea.
View Article and Find Full Text PDFGroup II metabotropic glutamate receptors (mGluR2 and mGluR3) may control relapse of alcohol seeking, but previously available Group II agonists were unable to discriminate between mGluR2 and mGluR3. Here we use AZD8529, a novel positive allosteric mGluR2 modulator, to determine the role of this receptor for alcohol-related behaviors in rats. We assessed the effects of AZD8529 (20 and 40 mg/kg s.
View Article and Find Full Text PDFCurrent antipsychotic drugs (APDs) show efficacy with positive symptoms, but are limited in treating negative or cognitive features of schizophrenia. Whereas all currently FDA-approved medications target primarily the dopamine D2 receptor (D2R) to inhibit G(i/o)-mediated adenylyl cyclase, a recent study has shown that many APDs affect not only G(i/o)- but they can also influence β-arrestin- (βArr)-mediated signaling. The ability of ligands to differentially affect signaling through these pathways is termed functional selectivity.
View Article and Find Full Text PDFThe proteasome cleaves intracellular proteins into peptides. Earlier studies found that treatment of human embryonic kidney 293T (HEK293T) cells with epoxomicin (an irreversible proteasome inhibitor) generally caused a decrease in levels of intracellular peptides. However, bortezomib (an antitumor drug and proteasome inhibitor) caused an unexpected increase in the levels of most intracellular peptides in HEK293T and SH-SY5Y cells.
View Article and Find Full Text PDFRationale: Operant self-administration (SA) is an important model of motivation to consume ethanol (EtOH), but low rates of voluntary consumption in rats are thought to necessitate water deprivation and saccharin/sucrose fading for acquisition of responding.
Objectives: Here, we sought to devise an effective model of SA that does not use water deprivation or saccharin/sucrose fading.
Methods: First, we tested if Wistar rats would acquire and maintain SA behavior of 20 % EtOH under two conditions, water deprivation (WD) and non-water deprivation (NWD).
Previously, we have shown that wild type N-ras (wt N-ras) harbors an anti-malignant effect against mutated Ras and in tumors without Ras mutations. To investigate the molecular bases of this anti-malignant activity, we have studied the potency of this anti-malignant effect in a model system against SV40 large T antigen (SV40T). We show that wild-type N-ras (wt N-ras) counteracts the effects of SV40T in NIH3T3 cells as seen by a decrease in proliferation, anchorage independence and changes in migration.
View Article and Find Full Text PDFConcomitant hereditary spherocytosis and sickle cell trait, although extremely rare, could potentially lead to splenic sequestration or infarction. We report here the first case of splenic infarction in a child with hereditary spherocytosis and sickle cell trait while flying on a commercial aircraft. The presence of hypoxia, hemoconcentrated erythrocytes, and sickle hemoglobin created the perfect environment for clinical sequelae.
View Article and Find Full Text PDFProbl Endokrinol (Mosk)
November 1977
The influence of various amounts (0.008; 0.0025; 0.
View Article and Find Full Text PDFChanges in the concentration of cytochromes c, c1 and a in the liver and heart homogenates during chick pre- and postnatal development were detected by means of low temperature differential spectrometry. At the early stages of development the high content of respiratory enzymes comparable with that in the adult organism is noted. By the end of embryogenesis the content of cytochromes decreased and, subsequently, increased.
View Article and Find Full Text PDF