Transfusional hemosiderosis in childhood cancer patients and survivors.

BACKGROUND: Children treated for cancer are at risk for adverse effects of iron due to transfusions administered during prolonged marrow suppression, which may increase exposure to toxic forms of iron, extrahepatic iron accumulation, and long-term organ damage. OBJECTIVE: This study aimed to characterize the severity and organ distribution of clinically significant, multisystem iron overload (IO) in an at-risk cohort of pediatric cancer patients. METHODS: This was a retrospective, cross-sectional study of childhood cancer patients who underwent a magnetic resonance imaging (MRI) due to clinical concern for IO. Data regarding cancer type and treatment, transfusion history, MRI and laboratory results, and treatment for IO were collected. Severity of IO was analyzed by non-parametric tests with respect to clinical characteristics. RESULTS: Of the 103 patients, 98% of whom had a Cancer Intensity Treatment Rating (ITR-3) of 3 or higher, 53% (54/102) had moderate or greater hepatic siderosis, 80% (77/96) had pancreatic siderosis, 4% (3/80) had cardiac siderosis, and 45% (13/29) had pituitary siderosis and/or volume loss. Pancreatic iron was associated with both cardiac (p = .0043) and pituitary iron (p = .0101). In the 73 off-therapy patients, ferritin levels were lower (p = .0008) with higher correlation with liver iron concentration (LIC) (p = .0016) than on-therapy patients. Fifty-eight subjects were treated for IO. CONCLUSION: In this heavily treated cohort of pediatric cancer patients, more than 80% had extrahepatic iron loading, which occurs with significant exposure to toxic forms of iron related to decreased marrow activity in setting of transfusions. Further studies should examine the effects of exposure to reactive iron on long-term outcomes and potential strategies for management.

A germ-free humanized mouse model shows the contribution of resident microbiota to human-specific pathogen infection.

Germ-free (GF) mice, which are depleted of their resident microbiota, are the gold standard for exploring the role of the microbiome in health and disease; however, they are of limited value in the study of human-specific pathogens because they do not support their replication. Here, we develop GF mice systemically reconstituted with human immune cells and use them to evaluate the role of the resident microbiome in the acquisition, replication and pathogenesis of two human-specific pathogens, Epstein-Barr virus (EBV) and human immunodeficiency virus (HIV). Comparison with conventional (CV) humanized mice showed that resident microbiota enhance the establishment of EBV infection and EBV-induced tumorigenesis and increase mucosal HIV acquisition and replication. HIV RNA levels were higher in plasma and tissues of CV humanized mice compared with GF humanized mice. The frequency of CCR5+ CD4+ T cells throughout the intestine was also higher in CV humanized mice, indicating that resident microbiota govern levels of HIV target cells. Thus, resident microbiota promote the acquisition and pathogenesis of two clinically relevant human-specific pathogens.

Cost-effectiveness of routine type and screens in select urological surgeries.

PURPOSE: To evaluate the cost-effectiveness of obtaining a preoperative type and screen (T/S) for common urologic procedures. METHODS: A decision tree model was constructed to track surgical patients undergoing two preoperative blood ordering strategies as follows: obtaining a preoperative T/S versus not doing so. The model was applied to the National (Nationwide) Inpatient Sample (NIS) data, from January 1, 2006 to September 30, 2015. Cost estimates for the model were created from combined patient-level data with published costs of a T/S, type and crossmatch (T/C), a unit of pRBC, and one unit of emergency-release transfusion (ERT). The primary outcome was the incremental cost per ERT prevented, expressed as an incremental cost-effectiveness ratio (ICER) between the two preoperative blood ordering strategies. A cost-effectiveness analysis determined the ICER of obtaining preoperative T/S to prevent an emergency-release transfusion (ERT), with a willingness-to-pay threshold of $1,500.00. RESULTS: A total of 4,113,144 surgical admissions from 2006 to 2015 were reviewed. The overall transfusion rate was 10.54% (95% CI, 10.17-10.91) for all procedures. The ICER of preoperative T/S was $1500.00 per ERT prevented. One-way sensitivity analysis demonstrated that the risk of transfusion should exceed 4.12% to justify preoperative T/S. CONCLUSION: Routine preoperative T/S for radical prostatectomy (rate = 3.88%) and penile implants (rate = .91%) does not represent a cost-effective practice for these surgeries. It is important for urologists to review their institution T/S policy to reduce inefficiencies within the preoperative setting.

Acute Intravascular Hemolysis Following an ABO Non-Identical Platelet Transfusion: A Case Report and Literature Review.

BACKGROUND Platelet transfusion is a common clinical practice required for therapeutic purposes in the setting of symptomatic thrombocytopenia, and, in some cases, prophylactically for asymptomatic thrombocytopenia. Crossmatch compatibility is not routinely done for platelet transfusions, and transfusion of ABO non-identical platelets has been adapted as an acceptable clinical practice. Acute intravascular hemolysis due to ABO non-identical platelets is a rare but clinically significant entity. Our case report reinforces the importance of a vigilant clinical approach in case of ABO non-identical platelet transfusions. CASE REPORT We report the case of 61-year-old woman with blood group A, with chemotherapy-induced asymptomatic thrombocytopenia, who developed acute intravascular hemolysis following transfusion of group O single-donor platelets (SDPs). The patient was transfused 1 unit of single-donor platelets for bleeding prophylaxis, as her platelet count dropped to less than 10×109/L due to chemotherapy that she was receiving for acute myeloid leukemia (AML). Immediately after transfusion, the patient noticed cherry-colored urine; and within 12 h of transfusion, her hemoglobin dropped by more than 2.5 g/dL. A post-transfusion immunohematology work-up showed positive DAT and high titers of anti-A1 isohemagglutinins in the platelet donor, supporting the diagnosis of acute intravascular hemolysis due to ABO non-identical platelets. CONCLUSIONS The possibility of acute intravascular hemolysis should be kept in mind in cases of transfusion of group O single donor platelets to non-group O recipients. ABO non-identical platelets, even with low isohemagglutinin titers, can cause significant adverse effects, particularly in newborns, children, and immunosuppressed and transfusion-dependent patients; therefore, a cautious clinical approach is recommended.

Trimethylamine N-oxide: breathe new life.

Association between elevated levels of systemic trimethylamine N-oxide (TMAO) and increased risk for adverse cardiovascular events have been proposed in recent years. Increasing experimental and clinical evidence in the last decade has implicated TMAO as an important contributor to the pathogenesis of cardiovascular diseases. TMAO, the oxygenated product of trimethylamine (TMA), belongs to the class of amine oxides. Most of the TMA derived from the metabolism of choline and L-carnitine by gut bacteria is absorbed into the bloodstream and gets rapidly oxidized to TMAO by the hepatic enzyme, flavin-containing monooxgenase-3. Here, we discussed the biosynthesis of TMAO and clinical studies that have assessed TMAO as a biomarker for various cardiovascular and other diseases such as kidney failure, thrombosis, atherosclerosis, obesity, diabetes and cancer. We also summarized the interaction of TMAO with synthetic and traditional molecules that together affect circulating TMAO levels. LINKED ARTICLES: This article is part of a themed section on Spotlight on Small Molecules in Cardiovascular Diseases. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v175.8/issuetoc.

Antioxidant Therapies for Ulcerative Dermatitis: A Potential Model for Skin Picking Disorder.

Skin Picking Disorder affects 4% of the general population, with serious quality of life impacts, and potentially life threatening complications. Standard psychoactive medications do not help most patients. Similarly, Mouse Ulcerative Dermatitis (skin lesions caused by excessive abnormal grooming behavior) is very common in widely used inbred strains of mice, and represents a serious animal welfare issue and cause of mortality. Treatment options for Ulcerative Dermatitis are largely palliative and ineffective. We have proposed mouse Ulcerative Dermatitis as a model for human Skin Picking Disorder based on similar epidemiology, behavior, and its comorbidity and mechanistic overlap with hair pulling (trichotillomania). We predicted that mouse Ulcerative Dermatitis would be treated by N-Acetylcysteine, as this compound is highly effective in treating both Skin Picking Disorder and Trichotillomania. Furthermore, we hypothesized that N-Acetylcysteine's mode of action is as a precursor to the production of the endogenous antioxidant glutathione in the brain, and therefore intranasal glutathione would also treat Ulcerative Dermatitis. Accordingly, we show in a heterogenous prospective trial, the significant reduction in Ulcerative Dermatitis lesion severity in mice receiving either N-acetylcysteine (oral administration) or glutathione (intranasal). The majority of mice treated with N-acetylcysteine improved slowly throughout the course of the study. Roughly half of the mice treated with glutathione showed complete resolution of lesion within 2-4 weeks, while the remainder did not respond. These findings are the first to show that the use of N-acetylcysteine and Glutathione can be curative for mouse Ulcerative Dermatitis. These findings lend additional support for mouse Ulcerative Dermatitis as a model of Skin Picking Disorder and also support oxidative stress and glutathione synthesis as the mechanism of action for these compounds. As N-Acetylcysteine is poorly tolerated by many patients, intranasal glutathione warrants further study as potential therapy in Skin Picking, trichotillomania and other body-focused repetitive behavior disorders.

Platelet transfusion for patients with cancer.

BACKGROUND: Platelet transfusion is a critical and often necessary aspect of managing cancer. Low platelet counts frequently lead to bleeding complications; however, the drugs used to combat malignancy commonly lead to decreased production and destruction of the very cell whose function is essential to stop bleeding. The transfusion of allogeneic platelet products helps to promote hemostasis, but alloimmunization may make it difficult to manage other complications associated with cancer. METHODS: The literature relating to platelet transfusion in patients with cancer was reviewed. RESULTS: Platelet storage, dosing, transfusion indications, and transfusion response are essential topics for health care professionals to understand because many patients with cancer will require platelet transfusions during the course of treatment. The workup and differentiation of non-immune-mediated compared with immune-mediated platelet refractoriness are vital because platelet management is different between types of refractoriness. CONCLUSIONS: A combination of appropriate utilization of platelet inventory and laboratory testing coupled with communication between those caring for patients with cancer and those providing blood products is essential for effective patient care.

Genetic variants in platelet factor 4 modulate inflammatory and platelet activation biomarkers.

BACKGROUND: African Americans suffer from higher prevalence and severity of atherosclerosis compared with whites, highlighting racial and ethnic disparities in cardiovascular disease. Previous studies have pointed to the role of vascular inflammation and platelet activation in the formation of atherosclerotic lesions. METHODS AND RESULTS: We explored the role of genetic variation in 4 chemokine/chemokine receptor genes (CX3CR1, CX3CL1, CXCR3, and PF4) on systemic inflammation and platelet activation serum biomarkers (fractalkine, platelet P-selectin, platelet factor 4 [PF4], and tumor necrosis factor-α). In total, 110 single nucleotide polymorphisms were tested among 1042 African Americans and 763 whites. The strongest association with serum PF4 levels was observed for rs168449, which was significant in both racial groups (P value: African Americans=0.0017, whites=0.014, combined=1.2 × 10(-4)), and remained significant after permutation-based multiple corrections (P(c) value: combined=0.0013). After accounting for the effect of rs168449, we identified another significant single nucleotide polymorphism (rs1435520), suggesting a second independent signal regulating serum PF4 levels (conditional P value: African Americans=0.02, whites=0.02). Together, these single nucleotide polymorphisms explained 0.98% and 1.23% of serum PF4 variance in African Americans and whites, respectively. Additionally, in African Americans, we found an additional PF4 variant (rs8180167), uncorrelated with rs168449 and rs1435520, associated with serum tumor necrosis factor-α levels (P=0.008, P(c)=0.048). CONCLUSIONS: Our study highlights the importance of PF4 variants in the regulation of platelet activation (PF4) and systemic inflammation (tumor necrosis factor-α) serum biomarkers.

Cervicovaginal evaluation in macaques used as a model for topical microbicide safety studies.

INTRODUCTION: Macaques are a commonly used non-human primate (NHP) model to evaluate safety and efficacy of topically applied vaginal microbicides. Cervicovaginal evaluation for topical microbicide safety studies requires proper technique, equipment, supplies, and sequence of sample collection. MATERIALS AND METHODS: Eleven rhesus macaques received a comprehensive sequential cervicovaginal examination under sedation before treatment and 24 hours post-instillation of test material. Examination was initiated with colposcopy, followed by diagnostics including vaginal culture, pH determination, cervicovaginal lavage, and cervicovaginal biopsy. RESULTS: Overall, the methods performed yielded samples that were appropriate for diagnostic evaluation and interpretation, and the macaques experienced minimal discomfort and complications. DISCUSSION: This paper provides a descriptive summary of compiled techniques required to conduct a safety evaluation for topically applied vaginal microbicides. This novel method-based approach should be methodically executed when evaluating a vaginally-applied, topical microbicide candidate.

Arrest of apoptosis in auditory neurons: implications for sensorineural preservation in cochlear implantation.

HYPOTHESIS: The JNK/c-Jun cell death pathway is a major pathway responsible for the loss of oxidative stress-damaged auditory neurons. BACKGROUND: Implantation of patients with residual hearing accentuates the need to preserve functioning sensorineural elements. Although some auditory function may survive electrode insertion, the probability of initiating an ongoing loss of auditory neurons and hair cells is unknown. Cochlear implantation can potentially generate oxidative stress, which can initiate the cell death of both auditory neurons and hair cells. METHODS: Dissociated cell cultures of P4 rat auditory neurons identified the apoptotic pathway initiated by oxidative stress insults (e.g., loss of trophic factor support) and characterized this pathway by arresting translation of pathway-specific mRNA with antisense oligonucleotide treatment and with the use of pathway specific inhibitors. The presence or absence of apoptosis-specific protein and changes in the level of neuronal survival measured the efficacy of these interventional strategies. RESULTS: These in vitro studies identified the JNK/c-Jun cascade as a major initiator of apoptosis of auditory neurons in response to oxidative stress. Neurons pretreated with c-jun antisense oligonucleotide and exposed to high levels of oxidative stress were rescued from apoptosis, whereas neurons in treatment control cultures died. Treatment of oxidative-stressed cultures with either curcumin, a MAPKKK pathway inhibitor, or PD-098059, a MEK1 inhibitor, blocked loss of neurons via the JNK/c-Jun apoptotic pathway. CONCLUSION: Blocking the JNK/c-Jun cell death pathway is a feasible approach to treating oxidative stress-induced apoptosis within the cochlea and may have application as an otoprotective strategy during cochlear implantation.