Vitamin K Deficiency Presenting in an Infant with an Anterior Mediastinal Mass: A Case Report and Review of the Literature

We report a case of a 1-month-old infant with spontaneous thymic hemorrhage secondary to severe vitamin K deficiency. He was brought to medical attention due to scrotal bruising and during evaluation was noted to be tachypneic and hypoxemic. Chest X-ray revealed an enlarged cardiothymic silhouette, and a follow-up echocardiogram revealed a mass in the anterior mediastinum. Routine laboratory work-up revealed severe coagulopathy. Further questioning revealed the patient had not received prophylactic vitamin K at birth. The coagulopathy resolved with administration of vitamin K, and a biopsy confirmed the anterior mediastinal mass was due to spontaneous thymic hemorrhage

Moderate hypoxia induces metabolic divergence in circulating monocytes and tissue resident macrophages from Berkeley sickle cell anemia mice

IntroductionHuman and murine sickle cell disease (SCD) associated pulmonary hypertension (PH) is defined by hemolysis, nitric oxide depletion, inflammation, and thrombosis. Further, hemoglobin (Hb), heme, and iron accumulation are consistently observed in pulmonary adventitial macrophages at autopsy and in hypoxia driven rodent models of SCD, which show distribution of ferric and ferrous Hb as well as HO-1 and ferritin heavy chain. The anatomic localization of these macrophages is consistent with areas of significant vascular remodeling. However, their contributions toward progressive disease may include unique, but also common mechanisms, that overlap with idiopathic and other forms of pulmonary hypertension. These processes likely extend to the vasculature of other organs that are consistently impaired in advanced SCD.MethodsTo date, limited information is available on the metabolism of macrophages or monocytes isolated from lung, spleen, and peripheral blood in humans or murine models of SCD.ResultsHere we hypothesize that metabolism of macrophages and monocytes isolated from this triad of tissue differs between Berkley SCD mice exposed for ten weeks to moderate hypobaric hypoxia (simulated 8,000 ft, 15.4% O2) or normoxia (Denver altitude, 5000 ft) with normoxia exposed wild type mice evaluated as controls.DiscussionThis study represents an initial set of data that describes the metabolism in monocytes and macrophages isolated from moderately hypoxic SCD mice peripheral lung, spleen, and blood mononuclear cells

Vitamin K Deficiency Presenting in an Infant with an Anterior Mediastinal Mass: A Case Report and Review of the Literature

We report a case of a 1-month-old infant with spontaneous thymic hemorrhage secondary to severe vitamin K deficiency. He was brought to medical attention due to scrotal bruising and during evaluation was noted to be tachypneic and hypoxemic. Chest X-ray revealed an enlarged cardiothymic silhouette, and a follow-up echocardiogram revealed a mass in the anterior mediastinum. Routine laboratory work-up revealed severe coagulopathy. Further questioning revealed the patient had not received prophylactic vitamin K at birth. The coagulopathy resolved with administration of vitamin K, and a biopsy confirmed the anterior mediastinal mass was due to spontaneous thymic hemorrhage

Extended red blood cell antigen matching for transfusions in sickle cell disease: a review of a 14-year experience from a single center. Transfusion. 2011;51(8):1732-1739. 27 version 1

BACKGROUND: Alloimmunization to red blood cell (RBC) blood group antigens is a major complication for patients with sickle cell disease (SCD), which limits the usefulness of RBC transfusion. Here, we report our experiences with extended RBC antigen matching for SCD patients. STUDY DESIGN AND METHODS: Records for 99 SCD patients transfused only with the extended matching protocol between 1993 and 2006 were reviewed. Patients and donors were phenotyped for 20 blood group antigens and RBC units that were negative for antigens not expressed by the recipient were provided. When necessary, mismatches were allowed at Le a , Le b , Fy b , and MNSs to meet requirements for antigens regarded as the most clinically significant. Matched RBC units (6946) were provided to 99 patients (mean, 70 units/patient; range, 1-519 units/patient). Eliminating mismatches, 90% of the transfusions matched all other negative antigens. RESULTS: Seven alloantibodies were detected in seven patients resulting in 7% alloimmunized at a rate of 0.1 antibodies per 100 units transfused. Three recipients who developed antibodies were D mosaic and would have been mistyped with serologic techniques. Alloimmunization was decreased compared to ABO and/or D matching at our institution and others. Twelve autoantibodies and no severe hemolytic transfusion reactions were reported. CONCLUSION: Exact matching for ABO, Rhesus, Kell, Kidd, and Fy a and extending this match whenever possible is an effective strategy to reduce alloimmunization to RBC antigens. Consideration should be given to exploring this conclusion further with a controlled, multiinstitutional trial to determine efficacy, cost-benefit analysis, and reproducibility of this approach

Determinants of safer sexual behavior in a long-term HIV-seropositive population

Determinants of safer sexual behaviors among HIV-infected adult men with hemophilia were examined. A model was proposed that personal adjustment, communication skills, self-efficacy, and perceived advantages of condom use would influence safer sex practices. The model was tested with 181 men with hemophilia and HIV infection from 27 hemophilia treatment centers across the United States. The hypothesized model was tested using LISREL and explained 35 percent of the variance in safer sexual behaviors. Personal adjustment was significantly associated with general communication skills. General communication was linked with communication about safer sex which, in turn, influenced self-efficacy and perceived advantages of condom use. Communication about safer sex, efficacy and perceived advantages of condom use were all directly related to safer sexual behaviors

Evidence supporting a role for circulating macrophages in the regression of vascular remodeling following sub‐chronic exposure to hemoglobin plus hypoxia

Macrophages are a heterogeneous population with both pro‐ and anti‐inflammatory functions play an essential role in maintaining tissue homeostasis, promoting inflammation under pathological conditions, and tissue repair after injury. In pulmonary hypertension, the M1 phenotype is more pro‐inflammatory compared to the M2 phenotype, which is involved in tissue repair. The role of macrophages in the initiation and progression of pulmonary hypertension is well studied. However, their role in the regression of established pulmonary hypertension is not well known. Rats chronically exposed to hemoglobin (Hb) plus hypoxia (HX) share similarities to humans with pulmonary hypertension associated with hemolytic disease, including the presence of a unique macrophage phenotype surrounding distal vessels that are associated with vascular remodeling. These lung macrophages are characterized by high iron content, HO‐1, ET‐1, and IL‐6, and are recruited from the circulation. Depletion of macrophages in this model prevents the development of pulmonary hypertension and vascular remodeling. In this study, we specifically investigate the regression of pulmonary hypertension over a four‐week duration after rats were removed from Hb + HX exposure with and without gadolinium chloride administration. Withdrawal of Hb + HX reversed systolic pressures and right ventricular function after Hb + Hx exposure in four weeks. Our data show that depleting circulating monocytes/macrophages during reversal prevents complete recovery of right ventricular systolic pressure and vascular remodeling in this rat model of pulmonary hypertension at four weeks post exposure. The data presented offer a novel insight into the role of macrophages in the processes of pulmonary hypertension regression in a rodent model of Hb + Hx‐driven disease