Methemoglobinemia is a rare disorder associated with oxidization of divalent ferroiron of hemoglobin (Hb) to ferri-iron of methemoglobin (MetHb). Methemoglobinemia can result from either inherited or acquired processes. Acquired forms are the most common, mainly due to the exposure to substances that cause oxidation of the Hb both directly or indirectly. Inherited forms are due either to autosomal recessive
FFP transfusion is a relatively frequent intervention in the NICU. In the present analysis, we found a remarkably high proportion of FFP transfusions given to non-bleeding neonates for indications not compliant with guideline recommendations. Platelet counts and coagulation studies were poor predictors of clinical bleeding.
The magnetic resonance (MR) identification of pituitary hyperintensity in the posterior part of the sella has been the most striking recent finding contributing to the diagnosis of "idiopathic" and permanent GH deficiency (GHD). Moreover, advancements in DNA technology have shed new light on the study of the genetic causes of hypopituitarism. Abnormalities in two genes, the GH-N encoding the GH and the GHRH receptor (GHRH-R), have been identified, while mutations in five other gene-encoding transcription factors such as Pit-1, Prop-1, Hesx-1, Lhx-3 and Lhx-4 involved in anterior pituitary development, have also been described. MR imaging shows marked differences in pituitary morphology indicating different GHD etiologies and different prognoses. Ectopic posterior pituitary is a specific marker of permanent GHD. These patients do not have Pit-1, Prop-1, or Lhx-3 mutations and should be carefully monitored for evolving pituitary hormone defects, though they do not require GH re-evaluation in adulthood; selected cases may have Hesx-1 or Lhx-4 mutations. MR evidence of normal or small anterior pituitary gland, enlarged empty sella, pituitary hyperplasia and/or intrasellar or suprasellar mass when associated with combined pituitary hormone deficiency call for molecular analysis of Pit-1, Prop-1, Hesx-1, or Lhx-3. Limitation of neck rotation and Chiari-I malformation may suggest Lhx-3 or Lhx-4 mutations (exceedingly rare). In "idiopathic" isolated GHD, evidence of normal anterior or small anterior pituitary size with normal location of posterior pituitary and normal connection between the hypothalamus and pituitary gland is suggestive of "transitory" or false positive GHD; patients with such characteristics should be re-evaluated well before reaching adult height. In selected cases, anterior pituitary height that is 2 SD below age-adjusted normal pituitary height could be suggestive of GHRH-R gene defect; it is worth pointing out that normal pituitary MR together with severe GHD has been observed, though rarely, in subjects with a genetic origin of GHD.
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