Thrombozytopenien des Neugeborenen

Thrombocytopenia with a platelet count <150×10⁹/l occurs in 0.1–2% of all preterm and term neonates. However, thrombocytopenia is one of the most frequent diagnoses among sick preterm and term neonates, affecting 18–35% of all patients admitted to the Neonatal Intensive Care Unit (NICU). The maturity of the neonate, the time of the onset of thrombocytopenia or bleeding as well as the underlying disease allow to distinguish between inherited and acquired thrombocytopenias, and furthermore to differentiate between early onset (<72 h) or late onset thrombocytopenias (>72 h). Based on an algorithm, the diagnostic procedures can be limited. In severe thrombocytopenias with associated risk of bleeding, platelet transfusions still remain the primary therapeutic option in neonates.     

Infection of immunodeficient horses with Sarcocystis neurona does not result in neurologic disease

Equine protozoal myeloencephalitis is a progressive neurologic disease of horses most commonly caused by infection with the apicomplexan parasite Sarcocystis neurona. Factors affecting neuroinvasion and neurovirulence have not been determined. We investigated the pathogenesis of infection with S. neurona in horses with severe combined immune deficiency (SCID). Two immunocompetent (IC) Arabian horses and two Arabian horses with SCID were infected orally with 5 x 10(5) sporocysts of S. neurona. Four IC horses and one SCID horse were infected intravenously (i.v.) with 5 x 10(8) merozoites of the WSU-1 isolate of S. neurona. Despite prolonged parasitemia and persistent infection of visceral tissues (skeletal muscle, cardiac muscle, lung, liver, and spleen) as demonstrated by PCR and culture, SCID horses did not develop neurologic signs after oral or i.v. infection. S. neurona was undetectable in the neuronal tissues of SCID horses by either PCR, immunohistochemistry, or culture. In contrast, although parasitemia was undetectable in orally infected IC horses and of only short duration in i.v. infected IC horses, four of six IC horses developed neurologic signs. S. neurona was detectable by PCR and/or culture of neural tissue but not visceral tissue of IC horses with neurologic disease. Infected SCID horses are unable to clear S. neurona from visceral tissues, but the infection does not result in neurologic signs; in contrast, IC horses rapidly control parasitemia and infection of visceral tissues but frequently experience neuroinvasion and exhibit clinical signs of neurologic disease.     

Physiologie der Megakaryopoiese und des Thrombozyten

Zusammenfassung Thrombozyten werden aus dem Zytoplasma von Megakaryozyten freigesetzt und haben eine entscheidende Funktion bei der Blutgerinnung. Sie sind auch in entzündliche Prozesse und die Wundheilung involviert. Die Proliferation und Differenzierung von Megakaryozyten wird durch die Bindung des Wachstumsfaktors Thrombopoietin (Tpo) an seinen Rezeptor c-Mpl stimuliert und reguliert. Glykoproteine der Thrombozytenmembran vermitteln bei Gefäßverletzung die Bindung von Thrombozyten an das subendotheliale Gewebe und die Aggregation zu hämostatischen Gerinnseln. Störungen der Megakaryopoiese, Thrombozytopoiese und Thrombozytenfunktion verursachen mit oder ohne Thrombozytopenie eine Gerinnungsstörung. Mit der molekularbiologischen Analyse ist es in jüngster Zeit gelungen, die Regulationskaskaden für die Plättchenfunktion, Thrombopoiese und Megakaryopoiese zunehmend besser zu verstehen und auf Krankheiten zu beziehen. Damit verknüpft sich die Hoffnung, gezielter in pathologische Prozesse eingreifen zu können.     

Unexpected results found in larvae samples from two postmortem forensic cases

Forensic Toxicology - In forensics, entomological specimens can be used as additional/alternative matrices to detect xenobiotics when human specimens are limited in their application. Despite some...