Neonatal Haematology. Irene Roberts. Читать онлайн. Newlib. NEWLIB.NET

Автор: Irene Roberts
Издательство: John Wiley & Sons Limited
Серия:
Жанр произведения: Медицина
Год издания: 0
isbn: 9781119371496
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By contrast, expression of the main platelet adhesion receptors appears to be similar in neonatal and adult platelets, with the exception of glycoprotein (Gp) IIb/IIIa, which is expressed at lower levels in neonatal platelets.152 Importantly, follow‐up studies have shown that previously impaired platelet responses in neonates are similar to adult responses within 2 weeks of birth.152,153 Another point of note is that most studies of neonatal platelet function have been carried out on cord blood platelet‐rich plasma. However, more recent studies on whole blood have shown that healthy neonates have robust primary haemostasis overall, despite apparently hypofunctional platelets as assessed using standard techniques in platelet‐rich plasma. This may, at least in part, be due to the higher haematocrit and higher levels of von Willebrand factor in neonates. In addition, measures of in vitro platelet activation and aggregation in cord blood do not match those obtained when studying peripheral blood.154 These observations have led some investigators to conclude that the function of neonatal platelets should not be viewed as impaired but, instead, that neonatal platelets function as a component of a generally well‐balanced neonatal haemostatic system.149

      Sample quality/artefacts

Photo depicts a blood film of a healthy term neonate with a normal blood count and no evidence of haemolysis, showing artefactual changes in red cell morphology apparent on different sections of the blood film.

      Site of sampling

      Gestational age and postnatal age

Photo depicts a blood film in maternal chorioamnionitis showing neutrophilia, left shift (myelocytes and promyelocytes) and toxic granulation. Photo depicts leucoerythroblastic blood film in a preterm neonate with hypoxic ischaemic encephalopathy showing a myelocyte, an NRBC, an eosinophil and a macropolycyte, likely to be a tetraploid cell.

      Pregnancy‐associated complications and mode of delivery

      1 1 Huyhn A, Dommergues M, Izac B, Croisille L, Katz W, Vainchenker W and Coulombel L (1995) Characterization of hematopoietic progenitors from human yolk sacs and embryos. Blood,