Genetic Mechanism of Human Neutrophil Antigen 2 Deficiency and Expression Variations

Human neutrophil antigen 2 (HNA-2) deficiency is a common phenotype as 3–5% humans do not express HNA-2. HNA-2 is coded by CD177 gene that associates with human myeloproliferative disorders. HNA-2 deficient individuals are prone to produce HNA-2 alloantibodies that cause a number of disorders including transfusion-related acute lung injury and immune neutropenia. In addition, the percentages of HNA-2 positive neutrophils vary significantly among individuals and HNA-2 expression variations play a role in human diseases such as myelodysplastic syndrome, chronic myelogenous leukemia, and gastric cancer. The underlying genetic mechanism of HNA-2 deficiency and expression variations has remained a mystery. In this study, we identified a novel CD177 nonsense single nucleotide polymorphism (SNP 829A>T) that creates a stop codon within the CD177 coding region. We found that all 829TT homozygous individuals were HNA-2 deficient. In addition, the SNP 829A>T genotypes were significantly associated with the percentage of HNA-2 positive neutrophils. Transfection experiments confirmed that HNA-2 expression was absent on cells expressing the CD177 SNP 829T allele. Our data clearly demonstrate that the CD177 SNP 829A>T is the primary genetic determinant for HNA-2 deficiency and expression variations. The mechanistic delineation of HNA-2 genetics will enable the development of genetic tests for diagnosis and prognosis of HNA-2-related human diseases.     

Localisation of GYIRFamide immunoreactivity inMacrostomum hystricinum marinum (Plathelminthes,Macrostomida)

The distribution of GYIRFamide immunoreactivity in the nervous system ofMacrostomum hystricinum marinum has been demonstrated by an indirect fluorescence technique in conjunction with confocal scanning laser microscopy (CSLM). Immunostaining was extensive in both the central (CNS) and peripheral (PNS) nervous systems, revealing detailed information on the microanatomy of the peptidergic nervous system of this free-living plathelminth. In the CNS, immunoreactive nerve cell bodies and nerve fibres occurred in the brain and along two pairs of longitudinal nerve cords: the main nerve cords and the ventral nerve cords. In the PNS, immunostaining was prevalent in nerve cells and fibres innervating the pharynx and the gut. The employed antibody is directed against a recently characterised FMRF-amide-related peptide (FaRP), GYIRFamide, isolated from two species of the Tricladida,Dugesia tigrina andBdelloura candida. Phylogenetically, GYIRFamide represents the most ancient neuropeptide thus far identified within the Bilateria     

NMDA-induced stimulation of glycolysis in developing hippocampal cell cultures

Developmental changes in energy metabolism of primary hippocampal cell cultures from newborn rats were investigated during the first 3 weeks. These changes were measured by intensity of and number of cells exhibiting NAD(P)H fluorescence in response to NMDA-induced activation of neuronal activity. We observed gradual changes of stimulation-evoked NAD(P)H signaling over the first 3 weeks, such that at day 7 and 16, this stimulation is minimal, while at 5 and 12 days, it is maximal. These results describe a biphasic pattern that was similar to earlier findings from experiments investigating developmental changes in population spike amplitudes or glutamate release in young rats. Inhibition of mitochondrial respiration by KCN revealed that the NMDA-evoked stimulation of energy metabolism is mainly due to increased glycolytic activity.     

Small cell undifferentiated carcinoma of the parotid gland. Cytologic, histologic, immunohistochemical and ultrastructural features of a neuroendocrine variant

A case of primary small cell undifferentiated carcinoma (SCUC) of the parotid gland, diagnosed initially by fine needle aspiration (FNA) cytology and confirmed by histology, immunohistochemistry and transmission electron microscopy (TEM), is presented. The FNA cytologic features that enabled an accurate diagnosis of this rare salivary gland tumor included nuclear granularity and markedly angular nuclear molding of numerous small cells that were usually present as large syncytia in an inflammatory background. Numerous mitotic figures were also present in this vascular lesion. These features were also evident in the surgical specimens. Immunohistochemistry demonstrated neuron-specific enolase positivity while TEM demonstrated intracytoplasmic neurosecretory granules in this case, indicating a neuroendocrine derivation for this neoplasm instead of the more usual origin of salivary gland SCUCs in ductal epithelial or myoepithelial tissue.     

Progress in treatment of ANCA-associated vasculitis

Autoantibodies to neutrophil cytoplasmic antigen-associated vasculitis (AAV) is characterised by inflammation of blood vessels. The introduction of immunosuppressive therapy with glucocorticoids and cyclophosphamide transformed AAV from a fatal condition to a largely treatable condition. Over the past 30 years, considerable progress has been made refining immunosuppressive regimens with a focus on minimising toxicity. There is, however, a high unmet need in the treatment of AAV. A proportion of patients are refractory to current therapies; 50% experience a relapse within 5 years and treatment toxicity contributes to mortality and chronic disability. As knowledge of the pathogenesis of vasculitis grows, it is mirrored by the availability of biological agents, which herald a revolution in the treatment of vasculitis. Lymphocyte-targeted and cytokine-targeted agents have been evaluated for the treatment of AAV and are entering the routine therapeutic arena with the potential to improve patient outcomes. As rare diseases, treatment advances in vasculitis depend on international collaborative research networks both to establish an evidence base for newer agents and to develop recommendations for patient management.     

Fine needle aspiration cytology of mucinous cystadenocarcinoma of the pancreas. Further observations

Mucinous cystadenocarcinoma of the pancreas is among the few potentially curable malignancies of this organ; recognition of the differences between this and other pancreatic tumors is thus of paramount importance. A second example of mucinous cystadenocarcinoma of the pancreas diagnosed by fine needle aspiration, performed under ultrasonographic guidance, is presented, emphasizing both the radiographic distinction from other cystic lesions plus cytologic features not previously stressed. In essence, the cytodiagnosis relies less on cell morphology, which is characteristically bland and relatively monomorphic, than on the presence of extracellular mucin, which must be distinguished from amorphous background material and necrotic debris. The possibility of diagnosing benign mucinous and serous cystadenomas by imaging and cytology is addressed.