SUMMARYThis is a case study describing the finding of a depressed skull fracture in a neonate who was delivered without instrumentation and with no history of trauma. Depressed skull fractures are described as being associated with forceps delivery both vaginally and with caesarean section but are much rarer without instrumentation. This obvious abnormality was very concerning for the parents as it was not picked up on antenatal scans and there was no clear cause. There were both cosmetic and neurological concerns and we found no clear consensus on appropriate treatment and prognosis in the literature we had available.
BACKGROUND
A murine leukemia retroviral vector was engineered to contain the DNA encoding either the wild-type, rat aorta 20-kDa myosin light chain (MLC20) or a mutant form of MLC20 in which Thr18 and Ser19 were mutated into alanines. These mutations result in a MLC20 that cannot be phosphorylated by myosin light chain kinase. An 11-amino acid epitope from c-myc was added to both MLC20 sequences to facilitate identification of these proteins. Madin-Darby canine kidney cells were stably transduced, and MLC20 expression was demonstrated by Western blot analysis using a myc-specific antibody. MLC20 exchange was demonstrated by purifying myosin from the transduced cells and repeating the Western blot analysis. Actin-activated adenosinetriphosphatase assays on the purified myosins demonstrated approximately 50% decrease in the rate of ATP hydrolysis by the myosin containing the mutant MLC20. Transepithelial electrical resistance was decreased and mannitol flux was increased across monolayers of cells expressing mutant MLC20. These data demonstrate that MLC20 phosphorylation is involved in regulating paracellular permeability and epithelial barrier function.
The purpose of this study was to elucidate the interactions between pituitary adenylate cyclase-activating peptide (PACAP)-(1--38) and phospholipids in vitro and to determine whether these phenomena modulate, in part, the vasorelaxant effects of the peptide in the intact peripheral microcirculation. We found that the critical micellar concentration of PACAP-(1--38) was 0.4-0.9 microM. PACAP-(1--38) significantly increased the surface tension of a dipalmitoylphosphatidylcholine monolayer and underwent conformational transition from predominantly random coil in saline to alpha-helix in the presence of distearoyl-phosphatidylethanolamine-polyethylene glycol (molecular mass of 2,000 Da) sterically stabilized phospholipid micelles (SSM) (P < 0.05). Using intravital microscopy, we found that aqueous PACAP-(1--38) evoked significant concentration-dependent vasodilation in the intact hamster cheek pouch that was significantly potentiated when PACAP-(1--38) was associated with SSM (P < 0.05). The vasorelaxant effects of aqueous PACAP-(1--38) were mediated predominantly by PACAP type 1 (PAC(1)) receptors, whereas those of PACAP-(1--38) in SSM predominantly by PACAP/vasoactive intestinal peptide type 1 and 2 (VPAC(1)/VPAC(2)) receptors. Collectively, these data indicate that PACAP-(1--38) self-associates and interacts avidly with phospholipids in vitro and that these phenomena amplify peptide vasoactivity in the intact peripheral microcirculation.
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