NTP-CERHR expert panel report on the reproductive and developmental toxicity of hydroxyurea

Prophylactic red cell transfusions for sickle cell disease pregnancy: increased use of therapy could transform outcomes

PURPOSE OF REVIEW

Pregnancy for people with sickle cell disease (SCD) is high risk with persistently high rates of severe maternal and fetal mortality and morbidity. Transfusion therapy is the best-studied treatment for SCD in pregnancy; hydroxyurea is not usually used because of teratogenicity concerns. In high-resource settings, red cell transfusions are likely underutilized, while in low-resource settings, they may be altogether unavailable.

RECENT FINDINGS

A randomized controlled trial and meta-analysis, two of the strongest forms of clinical research, show transfusion significantly reduces maternal and fetal death, painful crisis, thrombosis, and acute respiratory failure. Downstream benefits of treatment are less well measured and may include improving maternal anemia, reducing opioid exposure, and avoiding hospitalization, which presents risk for additional complications. Alloimmunization is a particular transfusion risk in SCD. However, many strategies can mitigate this risk. Accordingly, the American Society of Hematology classifies chronic transfusion in pregnancy as low risk.

SUMMARY

Given the low risk classification, lack of alternative therapies, dismal, stagnant pregnancy outcomes and the potential for profound treatment benefit, wider use of chronic transfusion therapy for SCD pregnancy is likely indicated. This review discusses the benefits and potential risks of prophylactic transfusions for SCD pregnancy. Use of chronic transfusions during pregnancy is indicated to help urgently transform outcomes.

Sickle cell disease and infertility risks: implications for counseling and care of affected girls and women

INTRODUCTION

Sickle cell disease (SCD), its treatments and cures present infertility risks. Fertility counseling is broadly indicated for affected girls and women and fertility preservation may appeal to some. Several streams of evidence suggest that the reproductive lifespan of women with SCD is reduced. Pregnancy is associated with high miscarriage rates. There are enduring questions about the effects of highly effective hydroxyurea treatment on female fertility. Current conditioning regimens for gene therapy or hematopoietic stem cell transplant are gonadotoxic. Fertility preservation methods exist as non-experimental standards of care for girls and women. Clinicians are challenged to overcome multifactorial barriers to incorporate fertility counseling and fertility preservation care into routine SCD care.

AREAS COVERED

Here we provide a narrative review of existing evidence regarding fertility and infertility risks in girls and women with SCD and consider counseling implications of existing evidence.

EXPERT OPINION

Addressing fertility for girls and women with SCD requires engaging concerns that emerge across the lifespan, acknowledging uncertainty and identifying barriers to care, some of which may be insurmountable without public policy changes. The contemporary SCD care paradigm can offer transformative SCD treatments alongside comprehensive counselling that addresses fertility risks and fertility preservation opportunities.

Managing sickle cell disease and related complications in pregnancy: results of an international Delphi panel

ABSTRACT

Data to guide evidence-based management of pregnant people with sickle cell disease (SCD) are limited. This international Delphi panel aimed to identify consensus among multidisciplinary experts for SCD management during pregnancy. The 2-round Delphi process used questionnaires exploring 7 topics (antenatal care, hydroxyurea use, transfusion, prevention of complications, treatment of complications, delivery and follow-up, and bottlenecks and knowledge gaps) developed by a steering committee. Thirteen panelists (hematologists, physiologists, obstetricians, maternal fetal medicine, and transfusion medicine physicians) from the United States, the United Kingdom, Turkey, and France completed the first survey; 12 panelists completed the second round. Anonymized responses were collected and summarized by a contract research organization (Akkodis Belgium). Consensus and strong consensus were predefined as 75% to 90% (9-10 of 12) and >90% (≥11 of 12) of panelists, respectively, agreeing or disagreeing on a response to a predefined clinical scenario or statement. In several areas of SCD management, consensus was achieved: experts recommended performing at least monthly multidisciplinary antenatal follow-up, administering prophylactic aspirin for preeclampsia prevention between gestational weeks 12 and 36, initiating prophylactic transfusion therapy in certain cases, or choosing automated red blood cell exchange over other transfusion methods for patients with iron overload or severe acute chest syndrome. No consensus was reached on several topics including the prophylactic aspirin dose, indications for starting infection prophylaxis, routine use of prophylactic transfusions, or use of prophylactic transfusions for preventing fetal complications. These recommendations could inform clinical care for patients with SCD who are pregnant in the absence of large clinical trials involving this population; the identified knowledge gaps can orient future research.

Society for Maternal-Fetal Medicine Consult Series #68: Sickle cell disease in pregnancy

Pregnant individuals with sickle cell disease have an increased risk of maternal and perinatal morbidity and mortality. However, prepregnancy counseling and multidisciplinary care can lead to favorable maternal and neonatal outcomes. In this consult series, we summarize what is known about sickle cell disease and provide guidance for sickle cell disease management during pregnancy. The following are Society for Maternal-Fetal Medicine recommendations.

Resumption of Spermatogenesis and Fertility Post Withdrawal of Hydroxyurea Treatment

Hydroxyurea (HU), a drug for treating cancers of the blood and the management of sickle cell anemia, induces hypogonadism in males. However, the impact of HU on testicular architecture and function, as well as its effects on the resumption of male fertility following treatment withdrawal, remain poorly understood. We used adult male mice to determine whether HU-induced hypogonadism is reversible. Fertility indices of mice treated with HU daily for ~1 sperm cycle (2 months) were compared with those of their control counterparts. All indices of fertility were significantly reduced among mice treated with HU compared to controls. Interestingly, significant improvements in fertility indices were apparent after a 4-month withdrawal from HU treatment (testis weight: month 1 post-HU withdrawal (M1): HU, 0.09 ± 0.01 vs. control, 0.33 ± 0.03; M4: HU, 0.26 ± 0.03 vs. control, 0.37 ± 0.04 g); sperm motility (M1: HU,12 vs. 59; M4: HU, 45 vs. control, 61%; sperm density (M1: HU, 1.3 ± 0.3 vs. control, 15.7 ± 0.9; M4: HU, 8.1 ± 2.5 vs. control, 16.8 ± 1.9 million). Further, circulating testosterone increased in the 4th month following HU withdrawal and was comparable to that of controls. When a mating experiment was conducted, recovering males sired viable offspring with untreated females albeit at a lower rate than control males (p < 0.05); therefore, qualifying HU as a potential candidate for male contraception.

Outcomes of Pregnancy in Sickle Cell Disease Patients: Results from the Prospective ESCORT-HU Cohort Study

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.

Application of zinc oxide nano-tube as drug-delivery vehicles of anticancer drug

CONTEXT

Zinc oxide nano-tube (ZnONT) nano-structures, which possess chemical stability and non-toxicity in the human body, are considered promising for delivering different drugs. Within this work, we scrutinized the drug delivery capability of the ZnONT and its adsorptional properties as a drug delivery vehicle (DDV) for hydroxyurea (HU) as an anti-cancer drug through density functional theory along with the solvent impacts. Based on the optimized structures, it can be suggested that Zn atoms of ZnONT are the ideal sites on this nano-tube for the adsorption of HU. HU had a strong physical adsorption through the O atom of carbonyl groups onto the local pyramidal site of the ZnONT. At 1.96 Å and Ead of -39.28 kcal/mol, in the configuration which was favorable in terms of energy, there was an interaction between the O atoms of -C=O group of the drug and a Zn atom of the ZnONT. In order to scrutinize the excited state properties of the HU-ZnONT complex, we also examined the UV/Vis data of the HU/ZnONT interaction system. Following the adsorption of HU onto the surface of the ZnONT, there was a significant red-shift based on the maximum absorption wavelength, showing that the ZnONT is an ideal candidate for optic sensors in order to detect and monitor the drug molecule. HU could be released in the cancer tissues where pH was low based on the drug release mechanism. The current work thoroughly investigated the mechanism of interaction between the ZnONT and HU, showing that ZnONT can be used for the smart drug delivery of HU. Overall, the findings suggest that ZnONT could be used as an efficient drug-delivery system for the HU drug to treat various types of cancer.

METHODS

In this work we used B3LYP-gCP-D3 functional and the basis set LANL2DZ on the transition metal (Zn) and the basis set cc-pVDZ on the others. GAMESS software program was employed for performing the calculations. we performed analyses, including charge transport, molecular electrostatic potential surface (MEP), energetic, electronic, natural bond orbitals (NBOs), and structural optimizations.

Lifestyle interventions to reduce endocrine-disrupting phthalate and phenol exposures among reproductive age men and women: A review and future steps

Non-persistent endocrine-disrupting chemicals (EDCs), including phthalates and phenols, are ubiquitous in both the environment and human body. A growing body of epidemiologic studies have identified concerning links between EDCs and adverse reproductive and developmental health effects. Despite consistent evidence, risk assessments and policy interventions often arrive late. This presents an urgent need to identify evidence-based interventions for implementation at both clinical and community levels to reduce EDC exposure, especially in susceptible populations. The reproductive life cycle (menarche to menopause for females and after pubertal onset for males) includes some of the most vulnerable periods to environmental exposures, such as the preconception and perinatal stages, representing a key window of opportunity to intervene and prevent unfavorable health outcomes. This review aims to synthesize and assess behavioral, dietary, and residential EDC-driven interventions to develop recommendations for subsequent, larger-scale studies that address knowledge-gaps in current interventions during the reproductive life cycle. We selected 21 primary interventions for evaluation, in addition to four supplemental interventions. Among these, accessible (web-based) educational resources, targeted replacement of (known) toxic products, and personalization of the intervention through meetings and support groups, were the most promising strategies for reducing EDC concentrations. However, we document a paucity of interventions to prevent phthalate and phenol exposures during the reproductive years, especially among men. Accordingly, we recommend additional, larger clinical and community-based intervention studies to reduce EDC exposure. Specifically, future intervention studies should focus on short-term, mid-, and long-term exposure reduction to phthalates and phenols. The latter, especially, is required for the development of clinical and public health guidelines to promote reproductive and developmental health globally.

Go the Distance

This overview of reproductive and sexual health care concerns for people with sickle cell disease (SCD) addresses clinical concerns that can be complex and are inherently multidisciplinary. Clinicians must be prepared to initiate reproductive health care discussions, as these intimate concerns may not be volunteered by patients. SCD is associated with delayed onset of puberty, sickle pain during menstruation, disease-specific contraceptive considerations, high-risk pregnancy, priapism, erectile dysfunction, and offspring who inherit a hemoglobinopathy trait from affected parents. Reproductive health considerations are underrecognized, undertreated, and understudied. They need attention in primary care and specialty SCD, urology, and obstetrics and gynecology clinics.

Pregnancy outcomes with hydroxyurea use in women with sickle cell disease

Hydroxyurea reduces pain crises, acute chest syndrome, and blood transfusions in sickle cell disease (SCD), but potential detrimental effects on fertility and birth outcomes impede its use. Data on the effects of hydroxyurea taken for SCD during conception and pregnancy are scarce. The Sickle Cell Disease Implementation Consortium collected self-reported pregnancy history, corresponding hydroxyurea use, and pregnancy outcomes in women with SCD in the clinical setting. Among 1285 women 18-45 years of age, 737 (57.4%) reported 1788 pregnancies (1079 live births, 394 miscarriages, 40 stillbirths, 207 abortions, 48 current pregnancies, and 20 missing outcomes) of which 241 (15.9%) live births, miscarriages or stillbirths were conceived while on hydroxyurea. In univariate analyses, pregnancy number more than three, severe sickle genotype, history of stillbirth or miscarriage, and chronic kidney disease at enrollment were covariates significantly associated with a pregnancy ending in miscarriage or stillbirth. After adjustment for covariates and additional SCD severity markers in multivariate analyses, hydroxyurea use during conception and pregnancy, but not during conception only, was associated with an increase in the odds ratio (OR) of miscarriage or stillbirth (OR 2.21, 95% confidence interval [CI] 1.40-3.47). In analyses of live birth outcomes, hydroxyurea use during conception and pregnancy was associated with birth weight < 5.5 pounds in full-term infants (OR 2.98, 95% CI 1.09-7.38) but not with prematurity or serious medical problems at birth. These findings suggest that hydroxyurea use may be safe up to the time of conception, but that clinicians should continue to advise caution regarding use during pregnancy.

Fertility after Curative Therapy for Sickle Cell Disease: A Comprehensive Review to Guide Care

Curative therapy for sickle cell disease (SCD) currently requires gonadotoxic conditioning that can impair future fertility. Fertility outcomes after curative therapy are likely affected by pre-transplant ovarian reserve or semen analysis parameters that may already be abnormal from SCD-related damage or hydroxyurea treatment. Outcomes are also likely affected by the conditioning regimen. Conditioning with myeloablative busulfan and cyclophosphamide causes serious gonadotoxicity particularly among post-pubertal females. Reduced-intensity and non-myeloablative conditioning may be acutely less gonadotoxic, but more short and long-term fertility outcome data after these approaches is needed. Fertility preservation including oocyte/embryo, ovarian tissue, sperm, and experimental testicular tissue cryopreservation should be offered to patients with SCD pursing curative therapy. Regardless of HSCT outcome, longitudinal post-HSCT fertility care is required.

Incorporation of novel therapies for the management of sickle cell disease: A pharmacist's perspective

Patients with sickle cell disease (SCD) experience significant disease-related morbidity including multiorgan damage, chronic anemia, and debilitating pain crises. While hydroxyurea has been the primary disease modifying modality in SCD, novel therapies with unique mechanism of action have recently been approved. This review article examines the evidence surrounding the available SCD therapies to guide pharmacists on potential treatment selection and management strategies for patients with SCD. A systematic search of online databases was performed to identify literature on the management of SCD. While the newly approved novel agents have demonstrated clinical benefit it remains unclear how these agents fit into the treatment paradigm. Pharmacists should be aware of the data supporting the use of these novel agents to optimize use on a patient-specific basis.

Fertility preservation for pediatric patients with hemoglobinopathies: Multidisciplinary counseling needed to optimize outcomes

Hemoglobinopathies are autosomal recessive disorders that occur when genetic mutations negatively impact the function of hemoglobin. Common hemoglobinopathies that are clinically significant include sickle cell disease, alpha thalassemia, and beta thalassemia. Advancements in disease-modifying and curative treatments for the common hemoglobinopathies over the past thirty years have led to improvements in patient quality of life and longevity for those who are affected. However, the diseases, their treatments and cures pose infertility risks, making fertility preservation counseling and treatment an important part of the contemporary comprehensive patient care. Sickle cell disease negatively impacts both male and female infertility, primarily by testicular failure and decreased ovarian reserve, respectively. Fertility in both males and females with beta thalassemia major are negatively impacted by iron deposition due to chronic blood transfusions. Hematopoietic stem cell transplant (HSCT) is currently the only curative treatment for SCD and transfusion dependent beta thalassemia. Many of the conditioning regimens for HSCT contain chemotherapeutic agents with known gonadotoxicity and whole-body radiation. Although most clinical studies on toxicity and impact of HSCT on long-term health do not evaluate fertility, gonadal failure is common. Male fertility preservation modalities that exist prior to gonadotoxic treatment include sperm banking for pubertal males and testicular cryopreservation for pre-pubertal boys. For female patients, fertility preservation options include oocyte cryopreservation and ovarian tissue cryopreservation. Oocyte cryopreservation requires controlled ovarian hyperstimulation (COH) with ten to fourteen days of intensive monitoring and medication administration. This is feasible once the patient has undergone menarche. Follicular growth is monitored via transvaginal or transabdominal ultrasound, and hormone levels are monitored through frequent blood work. Oocytes are then harvested via a minimally invasive approach under anesthesia. Complications of COH are more common in patients with hemoglobinopathies. Ovarian hyperstimulation syndrome creates a greater risk to patients with underlying vascular, pulmonary, and renal injury, as they may be less able to tolerate fluids shifts. Thus, it is critical to monitor patients undergoing COH closely with close collaboration between the hematology team and the reproductive endocrinology team. Counseling patients and families about future fertility must take into consideration the patient's disease, treatment history, and planned treatment, acknowledging current knowledge gaps.

Knowledge gaps in reproductive and sexual health in girls and women with sickle cell disease

There is an immediate need to address long-standing questions about the reproductive health of girls and women with sickle cell disease (SCD). There are many SCD-related reproductive risks and uncertainties across girls' and women's reproductive life span, with particularly outstanding concerns about menstruation, contraception, fertility and pregnancy. Extant literature addressing women's reproductive health topics is mostly descriptive; there are few high-quality interventional studies. In 2020, the Centers for Disease Control and Prevention and the Foundation for Women and Girls with Blood Disorders convened an expert panel to assess the knowledge gaps in women's reproductive health in SCD. The panel identified significant limitations to clinical care due to the need for research. The panel also identified prominent barriers to research and care. In this report, we frame these issues, providing a roadmap for investigators, funding agencies, and policy makers to advance care for girls and women with SCD.

Absence of hydroxyurea-induced mutational effects supports higher utilisation for the treatment of sickle cell anaemia

Hydroxyurea (hydroxycarbamide) is approved for treating both children and adults with sickle cell anaemia (SCA). Fetal haemoglobin (HbF) induction is the primary treatment response, along with improved anaemia, reduced haemolysis, myelosuppression and decreased endothelial inflammation. Hydroxyurea has proven clinical efficacy for SCA - treatment significantly reduces disease manifestations and prolongs survival. Despite these recognised benefits, long-standing concerns regarding the risks of mutagenic and potentially carcinogenic drug exposure have hampered efforts for broad hydroxyurea use in SCA, although these are based largely on outdated experimental models and treatment experiences with myeloproliferative neoplasms. Consequently, many patients with SCA are not receiving this highly effective disease-modifying therapy. In this review, we describe the concept of genotoxicity and its laboratory measurements, summarise hydroxyurea-associated data from both preclinical and clinical studies, and discuss carcinogenic potential. The genotoxicity results clearly demonstrate that hydroxyurea does not directly bind DNA and is not mutagenic. Rather, its genotoxic effects are limited to indirect clastogenicity occurring in select cell types, and only when high dose and time thresholds are exceeded. This absence of mutagenic activity is consistent with the observed lack of any compelling carcinogenic potential. Since hydroxyurea therapy for SCA carries minimal carcinogenic risks, the current drug labelling should be modified accordingly, and prescribing practices should be broadened to allow better access and increased utilisation of this highly effective drug.

Monoterpenes as therapeutic candidates to induce fetal hemoglobin synthesis and up-regulation of gamma-globin gene: An in vitro and in vivo investigation

Pharmacologically induced production of fetal hemoglobin (HbF) is a pragmatic therapeutic strategy for the reduction of globin chain imbalance and improving the clinical severities of patients with β-hemoglobinopathies. To identify highly desirable new therapeutic HbF-inducing agents, we screened functionally diverse ten monoterpenes, as molecular entities for their potent induction and erythroid differentiation ability in human erythroleukemia cell line (K562) and transgenic mice. Benzidine hemoglobin staining demonstrated six compounds to have significantly induced erythroid differentiation of K562 cells in a dose and time-dependent manner. This induction paralleled well with the optimal accumulated quantity of total hemoglobin in treated cultures. The cytotoxic studies revealed that three (carvacrol, 3-carene, and 1,4-cineole) of the six compounds with their maximal erythroid expansion ability did not affect cell proliferation and were found non-toxic. Four compounds were found to have high potency, with 4-8-fold induction of HbF at both transcriptional and protein levels in vitro. Subsequently, an in vivo study with the three active non-cytotoxic compounds showed significant overexpression of the γ-globin gene and HbF production. Carvacrol emerged as a lead HbF regulator suggested by the increase in expression of γ-globin mRNA content (5.762 ± 0.54-fold in K562 cells and 5.59 ± 0.20-fold increase in transgenic mice), accompanied by an increase in fetal hemoglobin (F-cells) levels (83.47% in K562 cells and 79.6% in mice model). This study implicates monoterpenes as new HbF inducing candidates but warrants mechanistic elucidation to develop them into potential therapeutic drugs in β-thalassemia and sickle cell anemia.

Management of sickle cell disease during pregnancy: experience in a third-level hospital and future recommendations

Objective: To describe the outcomes of sickle-cell disease in pregnancy according to the different treatments adopted before and during pregnancy and to propose a systematic approach to treat sickle-cell disease (SCD) during pregnancy.Methods: A retrospective descriptive study compared pregnancy outcomes among women with SCD who stopped hydroxyurea (HU) once pregnant (Group 1), were never treated before and during pregnancy (Group 2) or were treated by HU before conception who received prophylactic transfusion during pregnancy (Group 3). For each group we recorded the population's characteristics and the transfusion-related, obstetrical, perinatal and SCD complications.Results: We found 11 patients for group 1 (9/11 with at least 3 painful crises during the 12 months before conception), 4 for group 2 (3/4 with no sickle-cell complications during the year before pregnancy) and 2 for group 3 (one with previous multiorgan failure (MOF), one with previous stroke). No transfusion-related complication occurred. Group 1 and 2 developed SCD complications and a high number of acute transfusions and hospital admissions. Group 3 showed none of these complications, but one patient developed preeclampsia and preterm birth. Several obstetrical and perinatal complications occurred in group 1.Conclusion: Not treating sickle-cell during pregnancy increases maternal and perinatal morbidity, even in mildly affected women. All sickle-cell pregnancies should be treated, according to the treatment adopted before but also to patient's SCD-history. We propose chronic transfusion to women with previous stroke or MOF or already under transfusion program, and HU for severely and mildly affected patients, respectively from the second and third trimesters. Additional prospective studies are needed to validate the results of the proposed protocol.

Chemical-induced craniofacial anomalies caused by disruption of neural crest cell development in a zebrafish model

Background

Craniofacial anomalies are among the most frequent birth defects worldwide, and are thought to be caused by gene‐environment interactions. Genetically manipulated zebrafish simulate human diseases and provide great advantages for investigating the etiology and pathology of craniofacial anomalies. Although substantial advances have been made in understanding genetic factors causing craniofacial disorders, limited information about the etiology by which environmental factors, such as teratogens, induce craniofacial anomalies is available in zebrafish.

Results

Zebrafish embryos displayed craniofacial malformations after teratogen treatments. Further observations revealed characteristic disruption of chondrocyte number, shape and stacking. These findings suggested aberrant development of cranial neural crest (CNC) cells, which was confirmed by gene expression analysis of the CNC. Notably, these observations suggested conserved etiological pathways between zebrafish and mammals including human. Furthermore, several of these chemicals caused malformations of the eyes, otic vesicle, and/or heart, representing a phenocopy of neurocristopathy, and these chemicals altered the expression levels of the responsible genes.

Conclusions

Our results demonstrate that chemical‐induced craniofacial malformation is caused by aberrant development of neural crest. This study indicates that zebrafish provide a platform for investigating contributions of environmental factors as causative agents of craniofacial anomalies and neurocristopathy.

Attenuation potentials of royal jelly against hydroxyurea-induced infertility through inhibiting oxidation and release of pro-inflammatory cytokines in male rats

Hydroxyurea (HDU), a class of antineoplastic drugs, has a powerful efficacy in the treatment of several types of malignancies. However, it has multiple adverse effects including reduced fertility, especially in males. Thus, 60 male albino rats were used to investigate the chemoprotective potentials of royal jelly on HDU-induced testicular damage. Animals were gastro-gavaged with HDU (225 or 450 mg kg^-1 bw day^-1) before royal jelly (100 mg kg^-1 bw day^-1) for 60 days. Blood samples and testicles were collected, and spermatozoon was obtained. In a dose-dependent manner, the sperm count, motility and liveability, and testosterone, GSH, and catalase concentrations were decreased in HDU groups, whereas MDA, FSH, LH, IL-6, and IFN-γ expression levels were increased. Germinal epithelium degeneration, germ cell sloughing, reduction in the number of luminal spermatozoa, interstitial congestion, and severe leukocyte infiltration besides no glandular secretion in most of the acini were identified. However, royal jelly intake in HDU-treated rats successfully improved sperm quality, hormonal and antioxidant status, and reproductive organ histoarchitecture. Thus, it could be concluded that royal jelly is endowed with antioxidative and anti-inflammatory activities and could be, therefore, used as an adjuvant remedy to improve HDU-induced male subfertility.

Risks associated with fertility preservation for women with sickle cell anemia

OBJECTIVE

To highlight the risk of complications among women with sickle cell anemia (SCA) receiving fertility preservation treatment (FPT) before hematopoietic stem cell transplant (HSCT).

DESIGN

Single-center case series.

SETTING

Academic fertility center.

PATIENT(S)

Women aged 15-32 years with SCA undergoing FPT before HSCT.

INTERVENTION(S)

Retrospective, systematic review.

MAIN OUTCOME MEASURE(S)

FPT modality, SCA complications during FPT.

RESULT(S)

Over an 8-year period (2009-2017), seven women with SCA ages 15-32 years (mean 28.5 years) underwent FPT with embryo cryopreservation (n = 1), oocyte cryopreservation (n = 4), and ovarian tissue cryopreservation (n = 2). The five women subjects who underwent oocyte or embryo cryopreservation were treated with an antagonist controlled ovarian hyperstimulation protocol and individualized gonadotropin dosing. The trigger medications included leuprolide acetate (n = 2), and human chorionic gonadotropin (n = 3). Most patients (n = 5) received a disease-modifying therapy for SCA (hydroxyurea or chronic transfusions) before FPT. Three patients experienced periprocedural SCA complications that included life-threatening respiratory failure, painful crisis requiring interruption of a stimulation cycle, and severe postharvest painful crisis.

CONCLUSION(S)

Women with SCA may choose to undergo diverse FPT strategies before HSCT and are at risk for serious SCA-related complications. Evidence-based strategies to mitigate SCA-related morbidity and to optimize fertility preservation outcomes are needed.

Comparative prediction of binding affinity of Hydroxyurea anti-cancer to boron nitride and carbon nanotubes as smart targeted drug delivery vehicles

In this study, the adsorption of Hydroxyurea (HU) onto the inner and outer surfaces of boron nitride and carbon nanotubes (CNTs) was investigated using the density functional theory calculations and molecular dynamics (MDs) simulations in aqueous solution. The values of the adsorption energy show that HU molecule is preferentially adsorbed inside of boron nitride and CNTs with the molecular axis parallel to the tubes axis, which means that the cavity of nanotubes is favorable for encapsulation of this drug. Also, it was found that the HU/boron nitride nanotube (BNNT) system is more stable than the HU/CNT system. The stability of the complexes of HU/ BNNT attributed to the formation of the intermolecular hydrogen bonds between the H atoms of HU molecule and the N atoms of BNNT, which is confirmed by Bader's quantum theory of atoms in molecules. The natural bond orbital analysis shows the charge transfers occur from HU molecule to nanotubes in all complexes. Moreover, the adsorption of HU molecule on the surfaces of the nanotubes was investigated by explicit water models. Also, the adsorption behavior of HU on the functionalized boron nitride and CNTs is investigated to design and develop new nanocarriers for biomedical applications. Furthermore, MDs simulations are examined in the presence of one and two drug molecules. The obtained results illustrate that the lowest value of Lennard-Jones (L-J) energy between drug and nanotubes exist in the simulation system with two drug molecules.

Advances in the Treatment of Sickle Cell Disease

Sickle cell disease (SCD) is a monogenic disorder that afflicts approximately 100,000 Americans and millions of people worldwide. It is characterized by hemolytic anemia, vaso-occlusive crises, relentless end-organ injury, and premature death. Currently, red blood cell transfusion and hydroxyurea are the major disease-modifying therapies available for SCD. Hematopoetic stem cell transplant is curative, but barriers to treatment are substantial and include a lack of suitable donors, immunologic transplant rejection, long-term adverse effects, prognostic uncertainty, and poor end-organ function, which is especially problematic for older patients. Gene therapy to correct the β^s point mutation is under investigation as another curative modality. Deeper insights into the pathophysiology of SCD have led to the development of novel agents that target cellular adhesion, inflammation, oxidant injury, platelets and/or coagulation, vascular tone, and hemoglobin polymerization. These agents are in preclinical and clinical trials. One such agent, L-glutamine, decreases red blood cell oxidant injury and is recently US Food and Drug Administration approved to prevent acute pain episodes of SCD in patients 5 years of age or older. The purpose of this review is to describe the currently established therapies, barriers to curative therapies, and novel therapeutic agents that can target sickle cell hemoglobin polymerization and/or its downstream sequelae. A PubMed search was conducted for articles published up to May 15, 2018, using the search terms sickle cell disease, novel treatments, hematopoietic stem cell transplantation, and gene therapy. Studies cited include case series, retrospective studies, prospective clinical trials, meta-analyses, online abstracts, and original reviews.

Hydroxyurea-induced onychomadesis in a dog with chronic myeloid leukemia: A case report

A 12-year-old Rottweiler dog was presented with a history of prostration, weight loss and hyporexia for six months. Based on complete blood tests (hematological and biochemical analyses), bone marrow examination and imaging analysis, a diagnosis of chronic myeloid leukemia was made. Treatment with hydroxyurea at a dosage of 18 mg/kg twice daily was not effective in controlling the high count of white blood cells. Furthermore, after 35 days of hydroxyurea treatment, the animal developed onycholysis, with sloughing of the claws of the left pelvic and left thoracic limbs and exposure of the distal phalanx. Interruption of the medication was implemented, with clinical healing of the ungual lesions observed three months after initiation of the drug. White blood cells returned to normal after using cyclophosphamide. Currently, the animal is in complete remission, having a disease-free interval of 575 days without chemotherapy. To the authors' knowledge, this is the first report of hydroxyurea-induced onycholysis within a short-term period in a dog diagnosed with chronic myeloid leukemia.

In Vitro/In Vivo Evaluation of Radiolabeled [(99m)Tc(CO)3](+)-Hydroxyurea and Fluorescein Isothiocyanate-Hydroxyurea

The aim of current study is to examine hydroxyurea (HU), which is an antineoplastic drug used for the treatment of leukemia, sickle-cell disease, HIV, psoriasis, thrombocythemia, and various neoplastic diseases in two aspects. The active ingredient hydroxyurea was obtained by purification of the capsule form drug, commercially named as HYDREA. Then, [(99m)Tc(CO)3](+)core radiolabeling with HU was performed as first aspect. Quality control studies of (99m)Tc(CO)3-HU complex were performed by thin-layer radiochromatography and high-performance liquid radiochromatography methods. The results demonstrated that the radiolabeling yield was quite high (98.43% ± 2.29%). Also, (99m)Tc(CO)3-HU complex has good stability during the 24-hour period. Biological behavior of (99m)Tc(CO)3-HU complex is evaluated by biodistribution studies on Wistar Albino rats. Fluorescein isothiocyanate (FITC) labeling of HU was performed as second aspect. Fluorometric evaluation of binding efficacy and fluorescence imaging studies on MCF7 and Hela cell lines were carried out. It was thought that the knowledge achieved in this study would contribute to using (99m)Tc(CO)3-HU complex as an imaging agent, which inhibits the DNA synthesis selectively, by inhibiting ribonucleotide reductase enzyme. It was observed that FITC-HU has noteworthy incorporation on both cell lines.

Comparison of Chemical Sensitivity of Fresh and Long-Stored Heat Resistant Neosartorya fischeri Environmental Isolates Using BIOLOG Phenotype MicroArray System

Spoilage of heat processed food and beverage by heat resistant fungi (HRF) is a major problem for food industry in many countries. Neosartorya fischeri is the leading source of spoilage in thermally processed products. Its resistance to heat processing and toxigenicity makes studies about Neosartorya fischeri metabolism and chemical sensitivity essential. In this study chemical sensitivity of two environmental Neosartorya fischeri isolates were compared. One was isolated from canned apples in 1923 (DSM3700), the other from thermal processed strawberry product in 2012 (KC179765), used as long-stored and fresh isolate, respectively. The study was conducted using Biolog Phenotype MicroArray platforms of chemical sensitivity panel and traditional hole-plate method. The study allowed for obtaining data about Neosartorya fischeri growth inhibitors. The fresh isolate appeared to be much more resistant to chemical agents than the long-stored isolate. Based on phenotype microarray assay nitrogen compounds, toxic cations and membrane function compounds were the most effective in growth inhibition of N. fischeri isolates. According to the study zaragozic acid A, thallium(I) acetate and sodium selenate were potent and promising N. fischeri oriented fungicides which was confirmed by both chemical sensitivity microplates panel and traditional hole-plate methods.

Hydroxyurea induces chromosomal damage in G2 and enhances the clastogenic effect of mitomycin C in Fanconi anemia cells

Fanconi's anemia (FA) is a recessive disease; 16 genes are currently recognized in FA. FA proteins participate in the FA/BRCA pathway that plays a crucial role in the repair of DNA damage induced by crosslinking compounds. Hydroxyurea (HU) is an agent that induces replicative stress by inhibiting ribonucleotide reductase (RNR), which synthesizes deoxyribonucleotide triphosphates (dNTPs) necessary for DNA replication and repair. HU is known to activate the FA pathway; however, its clastogenic effects are not well characterized. We have investigated the effects of HU treatment alone or in sequential combination with mitomycin-C (MMC) on FA patient-derived lymphoblastoid cell lines from groups FA-A, B, C, D1/BRCA2, and E and on lymphocytes from two unclassified FA patients. All FA cells showed a significant increase (P < 0.05) in chromosomal aberrations following treatment with HU during the last 3 h before mitosis. Furthermore, when FA cells previously exposed to MMC were treated with HU, we observed an increase of MMC-induced DNA damage that was characterized by high occurrence of DNA breaks and a reduction in rejoined chromosomal aberrations. These findings show that exposure to HU during G2 induces chromosomal aberrations by a mechanism that is independent of its well-known role in replication fork stalling during S-phase and that HU interfered mainly with the rejoining process of DNA damage. We suggest that impaired oxidative stress response, lack of an adequate amount of dNTPs for DNA repair due to RNR inhibition, and interference with cell cycle control checkpoints underlie the clastogenic activity of HU in FA cells. Environ. Mol. Mutagen. 56:457-467, 2015. © 2015 Wiley Periodicals, Inc.

Toxicity of Hydroxyurea in Rats and Dogs

The toxicity of hydroxyurea, a treatment for specific neoplasms, sickle-cell disease, polycythemia, and thrombocytosis that kills cells in mitosis, was assessed in repeat-dose, oral gavage studies in rats and dogs and a cardiovascular study in telemetered dogs. Hydroxyurea produced hematopoietic, lymphoid, cardiovascular, and gastrointestinal toxicity with steep dose response curves. In rats dosed for 10 days, 50 mg/kg/day was tolerated; 500 mg/kg/day produced decreased body weight gain; decreased circulating leukocytes, erythrocytes, and platelets; decreased cellularity of thymus, lymph nodes, and bone marrow; and epithelial degeneration and/or dysplasia of the stomach and small intestine; 1,500 mg/kg/day resulted in deaths on day 5. In dogs, a single dose at ≥250 mg/kg caused prostration leading to unscheduled euthanasia. Dogs administered 50 mg/kg/day for 1 month had decreased circulating leukocytes, erythrocytes, and platelets; increased bone marrow cellularity with decreased maturing granulocytes; increased creatinine kinase activity; and increased iron pigment in bone marrow and hepatic sinusoidal cells. In telemetered dogs, doses ≥15 mg/kg decreased systolic blood pressure (BP); 50 mg/kg increased diastolic BP, heart rate, and change in blood pressure over time (+d P/d t), and decreased QT and PR intervals and maximum left ventricular systolic and end diastolic pressures with measures returning to control levels within 24 hr.

Establishment and assessment of a new human embryonic stem cell-based biomarker assay for developmental toxicity screening

A metabolic biomarker-based in vitro assay utilizing human embryonic stem (hES) cells was developed to identify the concentration of test compounds that perturbs cellular metabolism in a manner indicative of teratogenicity. This assay is designed to aid the early discovery-phase detection of potential human developmental toxicants. In this study, metabolomic data from hES cell culture media were used to assess potential biomarkers for development of a rapid in vitro teratogenicity assay. hES cells were treated with pharmaceuticals of known human teratogenicity at a concentration equivalent to their published human peak therapeutic plasma concentration. Two metabolite biomarkers (ornithine and cystine) were identified as indicators of developmental toxicity. A targeted exposure-based biomarker assay using these metabolites, along with a cytotoxicity endpoint, was then developed using a 9-point dose-response curve. The predictivity of the new assay was evaluated using a separate set of test compounds. To illustrate how the assay could be applied to compounds of unknown potential for developmental toxicity, an additional 10 compounds were evaluated that do not have data on human exposure during pregnancy, but have shown positive results in animal developmental toxicity studies. The new assay identified the potential developmental toxicants in the test set with 77% accuracy (57% sensitivity, 100% specificity). The assay had a high concordance (≥75%) with existing in vivo models, demonstrating that the new assay can predict the developmental toxicity potential of new compounds as part of discovery phase testing and provide a signal as to the likely outcome of required in vivo tests.

Effect of gold nanoparticles on properties of nanoliposomal hydroxyurea: an in vitro study

New hopes in cancer treatment have been emerged using functional nanoparticles. In this work, we tried to synthesize gold nanoparticles and gold nanoparticles conjugated with DNA extracted from human breast cancer cells. After synthesizing, gold nanoparticles were mixed with nanoliposomal hydroxyurea and corresponding compounds were formed. They were described by UV-Visible spectrophotometry and Zeta sizer. Amount of drug loading into liposomes was determined by spectrophotometry and cytotoxicity effect on MCF-7 cells was measure by MTT assay. Drug loading was determined to be 70 %. Size, size distribution and Zeta potential of particles were 473 nm, 0.46 and -21 mV for control nanoliposomal ones and 351 nm, 0.38 and -25 mV for nanoliposomal particles containing hydroxyurea. This was 29 nm, 0.23 and -30 mV for gold nanoparticles and 502 nm, 0.41 and -38 mV for nanoliposomes containing drug loaded by gold nanoparticles conjugated with DNA. It was found that nano conjugated complex in concentrations less than 20 μM of hydroxyurea can improve efficiency compared with liposomal drug. In maximum concentration of drug (2,500 μM), cytotoxicity was equal to 95 %. In minimum concentration of drug (5 μM), cytotoxicity of liposomal drug and conjugated complex were 70 and 81 %, respectively which probably comes from increased drug entry into cells due to the presence of gold nanoparticles. Free drug resulted in toxicity of 32 % in 5 μM and 88 % in 2,500 μM. Results demonstrated higher drug efficiency in nanoparticle form compared with free form which can be used in in vivo studies.

Sensitive windows of skeletal development in rabbits determined by hydroxyurea exposure at different times throughout gestation

The critical periods of axial skeletal development in rats and mice have been well characterized, however the timing of skeletal development in rabbits is not as well known. It is important to have a more precise understanding of this timing of axial skeletal development in rabbits due to the common use of this species in standard nonclinical studies to assess embryo-fetal developmental toxicity. Hydroxyurea, a teratogen known to induce a variety of fetal skeletal malformations, was administered to New Zealand White rabbits as a single dose (500 mg/kg) on individual days during gestation (gestation day, GD 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, or 19) and fetal external, visceral, and skeletal morphology was examined following cesarean sections on GD 29. A wide range of fetal skeletal effects was observed following hydroxyurea treatment, with a progression of malformations from anterior to posterior structures over time, as well as from proximal to distal structures over time. The sensitive window of axial skeletal development was determined to be GD 8 to 13, while disruption of appendicular and cranio-facial skeletal development occurred primarily from GD 11 to 16 and GD 11 to 12, respectively. The results of this study provide a better understanding of the critical developmental window for different segments of the rabbit skeleton, which will aid in the design of window studies to investigate teratogenicity in rabbits.

Myeloproliferative disorders in pregnancy

This article reviews pregnancy outcome in women diagnosed with a myeloproliferative neoplasm (MPN), and discusses possible risk markers and the pathogenesis of poor pregnancy outcome. An outline of the key factors regarding the diagnosis and management of MPN in women of reproductive potential is followed by a description of the authors' management strategy for standard and high-risk pregnancy in MPN patients.

Critical evaluation of key evidence on the human health hazards of exposure to bisphenol A

Despite the fact that more than 5000 safety-related studies have been published on bisphenol A (BPA), there seems to be no resolution of the apparently deadlocked controversy as to whether exposure of the general population to BPA causes adverse effects due to its estrogenicity. Therefore, the Advisory Committee of the German Society of Toxicology reviewed the background and cutting-edge topics of this BPA controversy. The current tolerable daily intake value (TDI) of 0.05 mg/kg body weight [bw]/day, derived by the European Food Safety Authority (EFSA), is mainly based on body weight changes in two- and three-generation studies in mice and rats. Recently, these studies and the derivation of the TDI have been criticized. After having carefully considered all arguments, the Committee had to conclude that the criticism was scientifically not justified; moreover, recently published additional data further support the reliability of the two- and three-generation studies demonstrating a lack of estrogen-dependent effects at and below doses on which the current TDI is based. A frequently discussed topic is whether doses below 5 mg/kg bw/day may cause adverse health effects in laboratory animals. Meanwhile, it has become clear that positive results from some explorative studies have not been confirmed in subsequent studies with higher numbers of animals or a priori defined hypotheses. Particularly relevant are some recent studies with negative outcomes that addressed effects of BPA on the brain, behavior, and the prostate in rodents for extrapolation to the human situation. The Committee came to the conclusion that rodent data can well be used as a basis for human risk evaluation. Currently published conjectures that rats are insensitive to estrogens compared to humans can be refuted. Data from toxicokinetics studies show that the half-life of BPA in adult human subjects is less than 2 hours and BPA is completely recovered in urine as BPA-conjugates. Tissue deconjugation of BPA-glucuronide and -sulfate may occur. Because of the extremely low quantities, it is only of minor relevance for BPA toxicity. Biomonitoring studies have been used to estimate human BPA exposure and show that the daily intake of BPA is far below the TDI for the general population. Further topics addressed in this article include reasons why some studies on BPA are not reproducible; the relevance of oral versus non-oral exposure routes; the degree to which newborns are at higher systemic BPA exposure; increased BPA exposure by infusions in intensive care units; mechanisms of action other than estrogen receptor activation; and the current regulatory status in Europe, as well as in the USA, Canada, Japan, New Zealand, and Australia. Overall, the Committee concluded that the current TDI for BPA is adequately justified and that the available evidence indicates that BPA exposure represents no noteworthy risk to the health of the human population, including newborns and babies.

How I treat essential thrombocythemia

In the past 5 years we have witnessed significant advances in both the diagnostic process and optimal therapy for patients with essential thrombocythemia (ET). Insights into the underlying molecular mechanisms have been accompanied by the development of new diagnostic tests and by an improved understanding of the relationship between ET and other related myeloproliferative neoplasms, such as polycythemia vera and primary myelofibrosis. In the first part of this review, we describe how recent molecular and histologic studies can be integrated into a streamlined diagnostic process that is applicable to everyday clinical practice. We also address areas of current diagnostic controversy, including heterogeneity within ET and the phenotypic overlap between ET, polycythemia vera, and primary myelofibrosis. In the second part, we provide an overview of our current approach to the treatment of ET, including risk stratification, choice of cytoreductive agent, and a consideration of special situations such as the pregnant or perioperative patient. Areas of controversy discussed include the identification of those at high risk of complications and therapeutic decisions in the younger patient.

Cucurbitacin D induces fetal hemoglobin synthesis in K562 cells and human hematopoietic progenitors through activation of p38 pathway and stabilization of the γ-globin mRNA

The search for novel therapeutic candidates targeting fetal hemoglobin (HbF) activation to reduce the imbalance of globin genes is regarded as a promising approach for the clinical management of sickle cell disease and β-thalassemia. For the first time, we identified cucurbitacin D (CuD), an oxygenated tetracyclic triterpenoid, as a molecular entity inducing γ-globin gene expression and HbF synthesis in K562 cells and human hematopoietic progenitors from a β-thalassemia patient. CuD demonstrated a higher potency in HbF induction when compared with hydroxyurea, which was revealed by the evidence that CuD results in a higher fetal cell percentage and greater HbF content in K562 cells, in addition, to being less cytotoxic. Moreover, CuD also promotes higher HbF expression in primary erythroid cells. In the study to elucidate the molecular mechanisms of CuD's action, our data indicated that CuD-stimulated HbF synthesis was mediated by p38 pathway activation. At the post-transcriptional level, CuD treatment led to a significant elongation of the γ-globin mRNA half-life in K562 cells. Taken together, the results suggest that CuD may be a potential therapeutic agent for β-hemoglobinopathies, including sickle cell anemia and β-thalassemia.

Epigenetic effects of endocrine-disrupting chemicals on female reproduction: an ovarian perspective

The link between in utero and neonatal exposure to environmental toxicants, such as endocrine-disrupting chemicals (EDCs) and adult female reproductive disorders is well established in both epidemiological and animal studies. Recent studies examining the epigenetic mechanisms involved in mediating the effects of EDCs on female reproduction are gathering momentum. In this review, we describe the developmental processes that are susceptible to EDC exposures in female reproductive system, with a special emphasis on the ovary. We discuss studies with select EDCs that have been shown to have physiological and correlated epigenetic effects in the ovary, neuroendocrine system, and uterus. Importantly, EDCs that can directly target the ovary can alter epigenetic mechanisms in the oocyte, leading to transgenerational epigenetic effects. The potential mechanisms involved in such effects are also discussed.