KEYWORDS trisomy 13 • trisomy 18 • neonate • congenital heart defects • neonatal intensive care • cardiac surgery ABSTRACTIntensive cardiac management such as pharmacological intervention for ductal patency (indomethacin and/or mefenamic acid for closure and prostaglandin E1 for maintenance) and palliative or corrective surgery is a standard treatment for congenital heart defects. However, whether it would be a treatment option for children with trisomy 13 or trisomy 18 syndrome is controversial because the efficacy on survival in patients with these trisomies has not been evaluated. We retrospectively reviewed 31 consecutive neonates with trisomy 13 or trisomy 18 admitted to our neonatal ward within 6 hr of birth between 2000 and 2005. The institutional management policies differed during three distinct periods. In the first period, both pharmacological ductal intervention and cardiac surgery were withheld. In the second, pharmacological ductal intervention was offered as an option, but cardiac surgery was withheld. Both strategies were available during the third period. The median survival times of 13, 9, and 9 neonates from the first, second, and third periods were 7, 24, and 243 days, respectively. Univariate and multivariate analyses confirmed that the patients in the third period survived significantly longer than the others. Intensive cardiac management consisting of pharmacological intervention for ductal patency and cardiac surgery was demonstrated to improve survival in patients with trisomy 13 or trisomy 18 in this series. Therefore, we suggest that this approach is a treatment option for cardiac lesions associated with these trisomies. These data are helpful for clinicians and families to consider in the optimal treatment of patients with these trisomies.
We show that precision measurements of the oblique correction parameters S and T can be used to derive an upper bound on the number of extra generations of heavy fermions Neg. The bound depends on the type of heavy neutrino masses. We have obtained Neg≤2 in the case of Dirac neutrinos and Neg≤5 in the case of neutrinos with Majorana masses, under some assumptions on the flavor and color contents of extra generations.
Impairment of axonal transport leads to neurodegeneration and synapse loss. Glutamate and amyloid beta-protein (Abeta) have critical roles in the pathogenesis of Alzheimer's disease (AD). Here we show that both agents rapidly inhibit fast axonal transport in cultured rat hippocampal neurons. The effect of glutamate (100 microm), but not of Abeta25-35 (20 microm), was reversible, was mimicked by NMDA or AMPA, and was blocked by NMDA and AMPA antagonists and by removal of extracellular Ca2+. The effect of Abeta25-35 was progressive and irreversible, was prevented by the actin-depolymerizing agent latrunculin B, and was mimicked by the actin-polymerizing agent jasplakinolide. Abeta25-35 induced intracellular actin aggregation, which was prevented by latrunculin B. Abeta31-35 but not Abeta15-20 exerted effects similar to those of Abeta25-35. Full-length Abeta1-42 incubated for 7 d, which specifically contained 30-100 kDa molecular weight assemblies, also caused an inhibition of axonal transport associated with intracellular actin aggregation, whereas freshly dissolved Abeta1-40, incubated Abeta1-40, and fresh Abeta1-42 had no effect. These results suggest that glutamate inhibits axonal transport via activation of NMDA and AMPA receptors and Ca2+ influx, whereas Abeta exerts its inhibitory effect via actin polymerization and aggregation. The ability of Abeta to inhibit axonal transport seems to require active amino acid residues, which is probably present in the 31-35 sequence. Full-length Abeta may be effective when it represents a structure in which these active residues can access the cell membrane. Our results may provide insight into the early pathogenetic mechanisms of AD.
Cardiac surgery is infrequently but increasingly being used to repair congenital heart defects associated with trisomy 18. The clinical details of trisomy 18 patients undergoing cardiac surgery have rarely been reported. Seventeen patients with trisomy 18 and serious cardiac symptoms underwent cardiac surgery in our institution. Age at surgery ranged from 7 to 258 days (median, 66 days). One patient had an atrioventricular septal defect and coarctation of the aorta. The remaining patients had ventricular septal defects, including four patients with coarctation of the aorta. Fourteen patients had associated patent ductus arteriosus. Fourteen patients underwent palliative surgery without cardiopulmonary bypass, and four of these underwent a second-stage intracardiac repair. The other three patients underwent primary intracardiac repair. Postoperatively, 14 patients (82%) were discharged home with improved symptoms. Survival from birth ranged from 12 to 1384 days (median, 324 days). Eight patients survived longer than 1 year. Median postoperative survival was 179 days. Postoperative survival was significantly better after palliative surgery (0 to 1239 days; median, 257 days) than after primary intracardiac repair (1 to 179 days; median, 48 days). Only one patient died of heart failure, suggesting that cardiac surgery was effective in preventing heart failure-related death.
An impressive body of evidence has been accumulated indicating that local protein synthesis is implicated in navigation of neurite extension induced by guidance cues, such as semaphorin3A (Sema3A). We found previously that a Src type tyrosine kinase Fyn and cyclin-dependent kinase 5 (Cdk5) mediate Sema3A-signaling. We also showed that Sema3A elicits axonal transport through neuropilin-1, a receptor for Sema3A, located at the growth cones. Here, we investigate the relationship between Sema3A-induced local signaling, protein synthesis, and axonal transport. Lavendustin A, a tyrosine kinase inhibitor, and olomoucine, a cyclin-dependent kinase inhibitor,
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