ABIN1 is a signal-induced autophagy receptor that attenuates NF-κB activation by recognizing linear ubiquitin chains

Linear ubiquitin chains play pivotal roles in immune signaling by augmenting NF-κB activation and suppressing programmed cell death induced by various stimuli. A20-binding inhibitor of NF-κB 1 (ABIN1) binds to linear ubiquitin chains and attenuates NF-κB activation and cell death induction. Although interactions with linear ubiquitin chains are thought to play a role in ABIN1-mediated suppression of NF-κB and cell death, the underlying molecular mechanisms remain unclear. Here, we show that upon stimulation by Toll-like receptor (TLR) ligands, ABIN1 is phosphorylated on Ser 83 and functions as a selective autophagy receptor. ABIN1 recognizes components of the MyD88 signaling complex via interaction with linear ubiquitin chains conjugated to components of the complex in TLR signaling, which leads to autophagic degradation of signaling proteins and attenuated NF-κB signaling. Our current findings indicate that phosphorylation and linear ubiquitination also play a role in downregulation of signaling via selective induction of autophagy.

Dermatomyositis Associated with Lung Neuroendocrine Carcinoma

Dermatomyositis is associated with various types of malignancy. However, the association of dermatomyositis with lung neuroendocrine carcinoma is rare. We herein report a case of dermatomyositis with lung neuroendocrine carcinoma.

Plexin-a4 mediates axon-repulsive activities of both secreted and transmembrane semaphorins and plays roles in nerve fiber guidance

It has been proposed that four members of the plexin A subfamily (plexin-As; plexin-A1, -A2, -A3, and -A4) and two neuropilins (neuropilin-1 and neuropilin-2) form complexes and serve as receptors for class 3 secreted semaphorins (Semas), potent neural chemorepellents. The roles of given plexin-As in semaphorin signaling and axon guidance, however, are mostly unknown. Here, to elucidate functions of plexin-A4 in semaphorin signaling and axon guidance events in vivo, we generated plexin-A4 null mutant mice by targeted disruption of the plexin-A4 gene. Plexin-A4 mutant mice were defective in the trajectory and projection of peripheral sensory axons and sympathetic ganglion (SG) axons and the formation of the anterior commissure and the barrels. The defects in peripheral sensory and SG axons were fundamentally related to those of neuropilin-1 or Sema3A mutant embryos reported but were more moderate than the phenotype in these mutants. The growth cone collapse assay showed that dorsal root ganglion axons and SG axons of plexin-A4 mutant embryos partially lost their responsiveness to Sema3A. These results suggest that plexin-A4 plays roles in the propagation of Sema3A activities and regulation of axon guidance and that other members of the plexin-A subfamily are also involved in the propagation of Sema3A activities. Plexin-A4-deficient SG axons did not lose their responsiveness to Sema3F, suggesting that plexin-A4 serves as a Sema3A-specific receptor, at least in SG axons. In addition, the present study showed that plexin-A4 bound class 6 transmembrane semaphorins, Sema6A and Sema6B, and mediated their axon-repulsive activities, independently of neuropilin-1. Our results imply that plexin-A4 mediates multiple semaphorin signals and regulates axon guidance in vivo.

Usefulness of vacuum-assisted cardiopulmonary bypass circuit for pediatric open-heart surgery in reducing homologous blood transfusion

OBJECTIVE

Open-heart surgery without homologous blood transfusion is still difficult in children because priming volume in cardiopulmonary bypass circuit results in extreme hemodilution. Vacuum-assisted cardiopulmonary bypass circuit has the benefit of improving venous return and results in lowering priming volume. We introduced vacuum-assisted cardiopulmonary bypass circuit in order to reduce priming volume for pediatric patients in March 1995. A retrospective study was made on the efficacy of vacuum-assisted circuit for pediatric open-heart surgery in reducing homologous blood transfusion.

METHODS

Patients weighing from 5 to 20 kg who underwent surgery between January 1991 and June 1996 were divided into two groups, group A comprised 128 patients before introduction of this circuit and group B comprised 49 patients after introduction, and their clinical course was compared. Vacuum-assisted circuit was used in 27 patients of group B.

RESULTS

The percentage of transfusion-free operations was significantly higher in group B than in group A (33.6% in group A vs. 53.1% in group B, P = 0.014), and particularly this percentage in patients weighing less than 10 kg significantly increased (0% in group A vs. 42.9% in group B, P < 0.01). The amount of homologous blood transfusion was significantly lower in group B than in group A (374 +/- 362 ml in group A and 212 +/- 287 ml in group B, P < 0.01). The rate of complications and the duration of respiratory support did not differ between the two groups. The duration of hospital stay was lower in group B than in group A.

CONCLUSIONS

The findings of this study indicate that vacuum-assisted circuit is useful for pediatric open-heart surgery in reducing homologous blood transfusion.

Variability in circadian activity patterns within the Culex pipiens complex (Diptera: Culicidae)

Circadian activity was compared among four strains of Culex pipiens molestus Forskal from Iran, Egypt, two localities (Ebira and Yanagawa) in Nagasaki, Japan, and one strain of Cx. p. pallens Coquillett from Japan. Under a 16:8 (L:D) h photoperiod, all the strains showed peaks of activity at lights on and off, with additional activity during both light and dark periods; Egyptian females and both sexes of Cx. p. pallens were inactive during the photophase. Under 0:24 (L:D) h, the length of the free-running activity period was significantly shorter in the "Iran" (21 h) than in the other three Cx. p. molestus strains (range, 21-23 h) and Cx. p. pallens (approximately 24 h). Under 24:0 (L:D) h, the activity rhythm was obscured. The length of the period was shorter in 24:0 (L:D) h than in 0:24 (L:D) h, violating Aschoff's circadian rule. Furthermore, the circadian peak did not always occur every day under 24:0 (L:D) h but rather exhibited "day-skipping."

Local cerebral glucose utilization in epileptic seizures of the mutant El mouse

The neural pathway and the focus of the epileptic seizure of mutant El mice were studied by the [14C]2-deoxyglucose technique. In the mice with full tonic-clonic seizure, the entire neocortex and hippocampus showed a remarkably increased metabolic rate. By contrast, a lower metabolic rate was evident in the thalamic nuclei, central gray, locus coeruleus and some interstitial nuclei. The epileptic focus in El mice presumably exists in the hippocampus.