Walter H. A. Kahr

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Platelets are classified as terminally differentiated cells that are incapable of cellular division. However, we observe that anucleate human platelets, either maintained in suspension culture or captured in microdrops, give rise to new cell bodies packed with respiring mitochondria and ␣-granules. Platelet progeny formation also occurs in whole blood(More)
Human β-defensins (hBD) are antimicrobial peptides that curb microbial activity. Although hBD's are primarily expressed by epithelial cells, we show that human platelets express hBD-1 that has both predicted and novel antibacterial activities. We observed that activated platelets surround Staphylococcus aureus (S. aureus), forcing the pathogens into(More)
Arthrogryposis, renal dysfunction, and cholestasis (ARC) syndrome is a fatal recessive disorder caused by mutations in the VPS33B or VPS16B genes. Both encode homologues of the Vps33p and Vps16p subunits of the HOPS complex necessary for fusions of vacuoles in yeast. Here, we describe a mutation in the full-of-bacteria (fob) gene, which encodes Drosophila(More)
Some familial platelet disorders are associated with predisposition to leukemia, myelodysplastic syndrome (MDS) or dyserythropoietic anemia. We identified a family with autosomal dominant thrombocytopenia, high erythrocyte mean corpuscular volume (MCV) and two occurrences of B cell-precursor acute lymphoblastic leukemia (ALL). Whole-exome sequencing(More)
Thrombolysis is considered to be contraindicated in acute ischemic stroke secondary to infective endocarditis (IE). We report a 12-year-old female who presented with acute dense right hemiparesis and aphasia. Cranial magnetic resonance imaging and angiography showed multiple diffusion-restricted lesions in the left hemisphere and absence of flow in the left(More)
Neutrophils deposit antimicrobial proteins, such as myeloperoxidase and proteases on chromatin, which they release as neutrophil extracellular traps (NETs). Neutrophils also carry key components of the complement alternative pathway (AP) such as properdin or complement factor P (CFP), complement factor B (CFB), and C3. However, the contribution of these(More)
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