Recognition of Infantile Spasms Is Often Delayed: The ASSIST Study.

OBJECTIVES: To characterize and quantify diagnostic and treatment delay among children with infantile spasms, and to estimate the developmental impact of this delay. STUDY DESIGN: In this cohort study, we surveyed the parents of 100 patients with infantile spasms about their experiences with diagnosis and treatment, and ascertained medical and sociodemographic factors potentially related to care of these infants. We specifically determined the latency to first visit an "effective provider," defined as a provider who identified infantile spasms, and prescribed an appropriate first-line treatment, namely adrenocorticotropic hormone, corticosteroids, or vigabatrin. Time to the first visit to an effective provider was evaluated using Cox proportional hazards regression. RESULTS: The median time from the onset of infantile spasms to first visit with an effective provider was 24.5 days. Only 29% of patients were evaluated by an effective provider within 1 week of infantile spasms onset. The time to first effective provider visit was associated with parental language preference, but with no other sociodemographic characteristics. Parents' suspicions that "something is wrong" were often discounted by healthcare providers, and survey respondents frequently reported that pediatricians and neurologists were unfamiliar with infantile spasms. CONCLUSION: This study demonstrates that substantial delay (ie, >1 week) in appropriate care is common, and suggests that the poor awareness of infantile spasms among healthcare providers is at least partly responsible for preventable and potentially significant delays in treatment.

A BAX/BAK and cyclophilin D-independent intrinsic apoptosis pathway.

Most intrinsic death signals converge into the activation of pro-apoptotic BCL-2 family members BAX and BAK at the mitochondria, resulting in the release of cytochrome c and apoptosome activation. Chronic endoplasmic reticulum (ER) stress leads to apoptosis through the upregulation of a subset of pro-apoptotic BH3-only proteins, activating BAX and BAK at the mitochondria. Here we provide evidence indicating that the full resistance of BAX and BAK double deficient (DKO) cells to ER stress is reverted by stimulation in combination with mild serum withdrawal. Cell death under these conditions was characterized by the appearance of classical apoptosis markers, caspase-9 activation, release of cytochrome c, and was inhibited by knocking down caspase-9, but insensitive to BCL-X(L) overexpression. Similarly, the resistance of BIM and PUMA double deficient cells to ER stress was reverted by mild serum withdrawal. Surprisingly, BAX/BAK-independent cell death did not require Cyclophilin D (CypD) expression, an important regulator of the mitochondrial permeability transition pore. Our results suggest the existence of an alternative intrinsic apoptosis pathway emerging from a cross talk between the ER and the mitochondria.

BH3-only proteins are part of a regulatory network that control the sustained signalling of the unfolded protein response sensor IRE1α.

Adaptation to endoplasmic reticulum (ER) stress depends on the activation of the unfolded protein response (UPR) stress sensor inositol-requiring enzyme 1α (IRE1α), which functions as an endoribonuclease that splices the mRNA of the transcription factor XBP-1 (X-box-binding protein-1). Through a global proteomic approach we identified the BCL-2 family member PUMA as a novel IRE1α interactor. Immun oprecipitation experiments confirmed this interaction and further detected the association of IRE1α with BIM, another BH3-only protein. BIM and PUMA double-knockout cells failed to maintain sustained XBP-1 mRNA splicing after prolonged ER stress, resulting in early inactivation. Mutation in the BH3 domain of BIM abrogated the physical interaction with IRE1α, inhibiting its effects on XBP-1 mRNA splicing. Unexpectedly, this regulation required BCL-2 and was antagonized by BAD or the BH3 domain mimetic ABT-737. The modulation of IRE1α RNAse activity by BH3-only proteins was recapitulated in a cell-free system suggesting a direct regulation. Moreover, BH3-only proteins controlled XBP-1 mRNA splicing in vivo and affected the ER stress-regulated secretion of antibodies by primary B cells. We conclude that a subset of BCL-2 family members participates in a new UPR-regulatory network, thus assuming apoptosis-unrelated functions.