Circadian transcription factor HSF1 regulates differential HSP70 gene transcription during the arousal-torpor cycle in mammalian hibernation.

Mammalian hibernation is a seasonal phenomenon. The hibernation season consists of torpor periods with a reduced body temperature (Tb), interrupted by euthermic arousal periods (interbout arousal, IBA). The physiological changes associated with hibernation are assumed to be under genetic control. However, the molecular mechanisms that govern hibernation-associated gene regulation are still unclear. We found that HSP70 transcription is upregulated in the liver of nonhibernating (summer-active) chipmunks compared with hibernating (winter-torpid) ones. In parallel, HSF1, the major transcription factor for HSP70 expression, is abundant in the liver-cell nuclei of nonhibernating chipmunks, and disappears from the nuclei of hibernating ones. Moreover, during IBA, HSF1 reappears in the nuclei and drives HSP70 transcription. In mouse liver, HSF1 is regulated by the daily Tb rhythm, and acts as a circadian transcription factor. Taken together, chipmunks similarly use the Tb rhythm to regulate gene expression via HSF1 during the torpor-arousal cycle in the hibernation season.

Successful treatment of an infected wound in infants by a combination of negative pressure wound therapy and arginine supplementation.

OBJECTIVE: Wound dehiscence caused by surgical site infection (SSI) presents a complicated problem. Negative pressure wound therapy (NPWT) was developed to treat wound dehiscence. Nutritional treatment using arginine has also been recently shown to be effective for the treatment of pressure ulcers. Therefore, wound complications due to SSI were treated using NPWT combined with nutritional therapy with an arginine-rich supplement (ARS). METHODS: Six pediatric patients with wound dehiscence due to SSI received this combined therapy. RESULTS: The average age of the patients was 12.2 mo. The operations that these patients underwent included laryngotracheal separation, radical operation for spinal bifida, gastrostomy, colostomy, anorectoplasty, and tumor extirpation. A local wound infection induced wound dehiscence in all patients. Therefore, NPWT was introduced with an enteral administration of ARS. All wounds completely healed within 1 mo after the introduction of this combined therapy without any other complications from the NPWT or ARS. A follow-up study at 6 mo after this therapy was completed showed no complications associated with the wounds. CONCLUSION: This combination therapy using NPWT and ARS administration was effective in inducing early healing of infected wound complications after surgery.