Human neutrophil development and functionality are enabled in a humanized mouse model.

Mice with a functional human immune system serve as an invaluable tool to study the development and function of the human immune system in vivo. A major technological limitation of all current humanized mouse models is the lack of mature and functional human neutrophils in circulation and tissues. To overcome this, we generated a humanized mouse model named MISTRGGR, in which the mouse granulocyte colony-stimulating factor (G-CSF) was replaced with human G-CSF and the mouse G-CSF receptor gene was deleted in existing MISTRG mice. By targeting the G-CSF cytokine-receptor axis, we dramatically improved the reconstitution of mature circulating and tissue-infiltrating human neutrophils in MISTRGGR mice. Moreover, these functional human neutrophils in MISTRGGR are recruited upon inflammatory and infectious challenges and help reduce bacterial burden. MISTRGGR mice represent a unique mouse model that finally permits the study of human neutrophils in health and disease.

Pediatric Donor Cell Acute Lymphoblastic Leukemia Following Bone Marrow Transplant for GATA2 Mutation.

Donor cell leukemia is a rare complication following hematopoietic stem cell transplant (HSCT). There are currently few reports in children and only rare, reported cases of donor-derived myelodysplastic syndrome/acute myeloid leukemia in patients with an underlying germline GATA2 mutation. Most reported cases are myeloid in origin and occur following related HSCT. We present a 3-year-old female who developed a donor-derived B-cell acute lymphoblastic leukemia 2 years post unrelated HSCT for GATA2 germline mutation.

Improving resource utilization: Axillary lymph node core biopsy triaging for lymphoma.

OBJECTIVES: To evaluate the utilization of hematopathology resources within our enterprise on axillary lymph node core biopsy (AxLNCB) specimens, particularly those obtained in the context of breast cancer screening. METHODS: The utilization of hematopathology resources was determined for all AxLNCB specimens over a 30-month period from across our enterprise, and chart review was performed for select patient demographics and radiographic features. The AxLNCB cases with benign histology were reviewed for subtyping of histologic patterns. RESULTS: Of the total 594 AxLNCB specimens, 61.6% were benign and 38.6% malignant. Of malignant cases, only 9.3% contained any hematologic malignancy, yet 94% of all cases received tissue triage for lymphoma, and 81% were reviewed at least in part by a hematopathologist. Six clinical parameters were found to independently predict risk of hematologic malignancy: male sex (P = .041), bilateral lymphadenopathy (P = .004), diffuse cortical thickening (P = .005), lack of breast cancer (P = .001), older age (P < .001), and history of hematologic malignancy (P < .001). CONCLUSIONS: Our enterprise overused hematopathology resources in the evaluation of AxLNCB performed in the study period. Our process could improve from the application of a simple tool generated from this cohort to predict percent risk of the specimen containing hematologic malignancy using patient characteristics easily found via routine chart review.

A Case of Unicentric Castleman Disease with Concomitant Myasthenia Gravis and Persistent Left Superior Vena Cava.

BACKGROUND Castleman disease was first described in 1956 as mediastinal masses composed of benign lymphoid hyperplasia with germinal center formation and capillary proliferation closely resembling thymomas. It has been linked with many multi-system disorders, including myasthenia gravis. Cases of Castleman disease with corresponding myasthenia gravis have higher rates of postoperative myasthenic crisis, which are reported as high as 37.5%. We encountered a case of Castleman disease with myasthenia gravis that was discovered early and managed successfully with complete surgical resection and no postoperative myasthenic crisis. CASE REPORT A 25-year-old woman with an uncomplicated history presented with shortness of breath, numbness in hands, tiring with chewing, and fatigue. Myasthenia gravis was diagnosed with serology test results, and a 7.5×7.0-cm mediastinal mass was discovered in addition to the incidental finding of a persistent left superior vena cava, closely abutting the mass. Biopsy showed lymphoid proliferation, regressed germinal centers surrounded by small lymphocytes, and vascular proliferation, consistent with unicentric Castleman disease, hyaline-vascular type. The patient was successfully treated for Castleman disease with myasthenia gravis, and no postoperative myasthenic crisis occurred. CONCLUSIONS Castleman disease associated with myasthenia gravis can dramatically increase the risk of postoperative myasthenic crisis. Our literature review of all 16 cases of Castleman disease with myasthenia gravis since 1973 revealed that 18.75% of cases were associated with a postoperative myasthenic crisis. This association elicits the importance of prompt diagnosis of myasthenia gravis when evaluating mediastinal masses and the value of having neurology and anesthesiology staff aware of the increased risk of crisis.

Mass Cytometry in Hematologic Malignancies: Research Highlights and Potential Clinical Applications.

Recent advances in global gene sequencing technologies and the effect they have had on disease diagnosis, therapy, and research have fueled interest in technologies capable of more broadly profiling not only genes but proteins, metabolites, cells, and almost any other component of biological systems. Mass cytometry is one such technology, which enables simultaneous characterization of over 40 parameters per cell, significantly more than can be achieved by even the most state-of-the-art flow cytometers. This mini-review will focus on how mass cytometry has been utilized to help advance the field of neoplastic hematology. Common themes among published studies include better defining lineage sub-populations, improved characterization of tumor microenvironments, and profiling intracellular signaling across multiple pathways simultaneously in various cell types. Reviewed studies highlight potential applications for disease diagnosis, prognostication, response to therapy, measurable residual disease analysis, and identifying new therapies.

Mimicking Myelodysplastic Syndrome: Importance of Differential Diagnosis.

Copper deficiency is a rare nutritional deficiency with hematological manifestations that mimic those found in myelodysplastic syndrome, a hematological malignancy incurable without allogeneic hematopoietic stem cell transplantation. Bone marrow biopsy findings and peripheral blood counts are oftentimes insufficient to differentiate the two conditions. Moreover, the symptoms of copper deficiency can arise years after the surgery, making diagnosis a challenge. In patients with new-onset pancytopenia, copper deficiency must be considered on the differential, especially in the setting of known risk factors such as bariatric surgery, zinc supplementation, and celiac disease. Herein, we present a case of a 61-year-old female with a remote history of gastric bypass being evaluated for MDS in the context of progressive pancytopenia and new-onset paresthesias. The patient was found to have low serum copper and ceruloplasmin. Copper supplementation largely resolved the hematological abnormalities, but the limb paresthesias remain. This case highlights the need to identify copper deficiency early and distinguish it from MDS in order to prevent permanent neurological deficits and catastrophic response should the patient undergo hematopoietic stem cell transplantation.

Characterization of proteomic and metabolomic responses to dietary factors and supplements.

Over the past decade there has been a renewed interest in research and development of both dietary and nutritional supplements. Significant advancements have been made in the scientific assessment of the quality, safety, and efficacy of these products because of the strong interest in and financial support of these projects. As research in both fields continues to advance, opportunities to use new and innovative research technologies and methodologies, such as proteomics and metabolomics, are critical for the future progress of the science. The purpose of the symposium was to begin the process of communicating new innovative proteomic and metabolomic methodologies that may be applied by researchers in both the nutrition and the natural product communities. This symposium highlighted 2 proteomic approaches, protein fingerprinting in complex mixtures with peptoid microarrays and top-down mass spectrometry for annotation of gene products. Likewise, an overview of the methodologies used in metabolomic profiling of natural products was presented, and an illustration of an integrated metabolomics approach in nutrition research was highlighted.

Cervical Lymphadenopathy and Airway Masses in a Child.

A previously healthy 12-year-old boy presented with a 3-month history of nasal obstruction, progressive dysphonia, recurrent deep neck abscesses, and tender, bulky cervical lymphadenopathy. What is your diagnosis?

R634W KIT Mutation in an Adult With Systemic Mastocytosis.

Mastocytosis is a clonal neoplasm with the potential to affect various organs within the body. It can range in clinical severity from benign to extremely aggressive. Mastocytosis can be separated into cutaneous, systemic, and leukemic forms, as well as mast-cell sarcoma and extracutaneous mastocytoma. It is most often an acquired condition but can be inherited; the most commonly identified genetic aberrations leading to mastocytosis are activating mutations involving codon 816 of the KIT gene. Herein, we present the case of a 30-year-old Caucasian man with systemic mastocytosis discovered to have a p.Arg634Trp mutation involving KIT. To our knowledge, this mutation has previously only been identified in children with familial urticarial pigmentosa. Ours is the the first case report in the literature of an adult with systemic mastocytosis likely due to a p.Arg634Trp KIT mutation.

Population-based analysis of prognostic factors and survival in familial melanoma.

PURPOSE: Familial melanoma patients are reported to present with thinner melanomas, to be younger at the time of diagnosis, and to have a greater likelihood of developing multiple primary tumors. We sought to determine whether melanomas that occur in a familial setting demonstrate different prognostic and survival statistics relative to sporadic melanoma. PATIENTS AND METHODS: This population-based study used the Utah Cancer Registry and Utah Population Database to objectively evaluate prognostic and survival statistics of the familial melanoma population. From 1973 to 1999, there were 7,785 cases of invasive melanoma identified through the Utah Cancer Registry. These were linked to the Utah Population Database, resulting in 2,659 subjects with family-history information from which a familiality score could be calculated. Cases scored in the top ninth percentile were assigned as high familial risk, and the remaining 91% were considered low familial risk. RESULTS: Multivariate logistic-regression analysis found no association between sex, Breslow depth, Clark level, or survival and the familial status. Age at first diagnosis of invasive melanoma was slightly lower in the high-familial-risk group (57 v 60 years; P = .03). High-familial-risk subjects had more melanomas diagnosed at age 30 or younger (12% v 6%; P < .001). A significant difference in the overall number of individuals with two or more primary malignant melanomas was not detected among the groups (P = .2). CONCLUSION: These data suggest that melanomas occurring in the context of an underlying inherited susceptibility do not have a significantly different biologic behavior.

Novel Developments in Leukopenia and Pancytopenia.

Cytopenias are not disease entities in and of themselves; rather, they are the expression of various underlying disease processes. Careful attention to details in patients' presentation, careful history and examination, as well as attention to the ancillary parameters of the complete blood count with a peripheral blood smear can point the clinician toward the appropriate workup. Causes of cytopenias can be inherited or acquired; the latter include medication related, autoimmune, or neoplastic causes. Emergencies need to be recognized in a timely fashion and expert consultation obtained.

Essential roles for the Dhr78 orphan nuclear receptor during molting of the Drosophila tracheal system.

The Drosophila Dhr78 orphan nuclear receptor has been proposed to play a role in molting of the tracheal cuticle and regulate gene expression during the third larval instar, possibly in response to a novel systemic hormonal signal. Here, we show that there are no essential maternal functions for Dhr78 during development, and that mutants missing both maternal and zygotic Dhr78 function die primarily during second and third instar larval development. We show that defects in the tracheal system can be observed as early as the first instar, manifested as regions of fluid in the dorsal tracheal trunks. In addition, Dhr78 mutant tracheae show a highly penetrant defect in gas filling at the first-to-second instar larval molt. Dhr78 expression in only the tracheal system is sufficient to rescue the lethality of Dhr78 mutants, and selective inactivation of Dhr78 function in the tracheae by targeted RNAi is sufficient to result in tracheal defects. Finally, we see no evidence for widespread activation of the Dhr78 ligand binding domain in third instar larvae using the GAL4-LBD system, arguing against a systemic hormone for the receptor at this stage in development. Taken together, our results indicate that Dhr78 exerts its essential functions during molting of the tracheal cuticle in Drosophila.

Clitoral epidermoid cyst presenting as pseudoclitoromegaly of pregnancy.

Objective Acquired clitoromegaly is rare and may result from hormonal and nonhormonal causes, and evaluation of the pregnant patient with clitoromegaly invokes a specific set of differential diagnoses. Methods Case report. Results We describe the case of a young woman with pregnancy-associated clitoral enlargement whose hormonal evaluation proved negative. Further investigation concluded that an epidermoid cyst was the culprit of her pseudoclitoromegaly. The patient underwent successful surgical resection and has had no recurrence at her subsequent pregnancy. Conclusion We review the differential diagnosis of clitoromegaly, including hormonal and nonhormonal causes, with focus on the evaluation of pregnancy-associated clitoromegaly.

Rapid identification of orexin receptor binding ligands using cell-based screening accelerated with magnetic beads.

We report here a simple and rapid method by which to screen one bead one compound libraries for highly specific ligands to cell surface proteins such as G protein-coupled receptors. This protocol, which harvests "hits" in a cell-based binding screen magnetically, eliminates the most tedious aspects of previously published bead screening techniques and allows millions of different compounds to be screened rapidly and cheaply. The method is demonstrated using the orexin receptor 1, which resulted in the isolation of moderate potency antagonists.

Seamless bead to microarray screening: rapid identification of the highest affinity protein ligands from large combinatorial libraries.

Several approaches have been developed for screening combinatorial libraries or collections of synthetic molecules for agonists or antagonists of protein function, each with its own advantages and limitations. In this report, we describe an experimental platform that seamlessly couples massively parallel bead-based screening of one-bead one-compound combinatorial libraries with microarray-based quantitative comparisons of the binding affinities of the many hits isolated from the bead library. Combined with other technical improvements, this technique allows the rapid identification of the best protein ligands in combinatorial libraries containing millions of compounds without the need for labor-intensive resynthesis of the hits.