C-terminal trans-activation sub-region of VP16 is uniquely required for forskolin-induced herpes simplex virus type 1 reactivation from quiescently infected-PC12 cells but not for replication in neuronally differentiated-PC12 cells.

The HSV-1 tegument protein VP16 contains a trans-activation domain (TAD) that is required for induction of immediate early (IE) genes during lytic infection and induced reactivation from latency. Here we report the differential contributions of the two sub-regions of the TAD in neuronal and non-neuronal cells during activation of IE gene expression, virus replication, and reactivation from quiescently infected (QIF)-PC12 cells. Our studies show that VP16- and chemical (hexamethylenebisacetamide)-induced IE gene activation is attenuated in neuronal cells. Irrespective of neuronal or non-neuronal cell backgrounds, IE gene activation demonstrated a greater requirement for the N-terminal sub-region of VP16 TAD (VP16N) than the C-terminal sub-region (VP16C). In surprising contrast to these findings, a recombinant virus (RP4) containing the VP16N deletion was capable of modest forskolin-induced reactivation whereas a recombinant (RP3) containing a deletion of VP16C was incapable of stress-induced reactivation from QIF-PC12 cells. These unique process-dependent functions of the VP16 TAD sub-regions may be important during particular stages of the virus life cycle (lytic, entrance, and maintenance of a quiescent state and reactivation) when viral DNA would be expected to be differentially modified.

Use of a Pressure Cooker to Achieve Sterilization for an Expeditionary Environment.

BACKGROUND: Sterilization of healthcare instruments in an expeditionary environment presents a myriad of challenges including portability, cost, and sufficient electrical power. Using pressure cookers to sterilize instruments presents a low-cost option for sterilization in prehospital settings. This project's objective was to determine if sterility can be achieved using a commercially available pressure cooker. METHODS: Presto® 4-quart stainless steel pressure cookers were heated using Cuisinart® CB-30 cast-iron single burners. One 3M™ Attest™ 1292 Rapid Readout Biological Indicator and one 3M™ Comply™ SteriGage™ integrator strip were sealed in a Henry Schein® Sterilization Pouch and placed in a pressure cooker and brought to a pressure of 103.4kPa. Sterility was verified after 20 minutes at pressure. The Attest vials were incubated in a 3M Attest 290 Auto-Reader for 3 hours with a control vial. RESULTS: Sterility using the pressure cooker was achieved in all tested bags, integrator strips, and Attest vials (n = 128). The mean time to achieve the necessary 103.4kPa was 379 seconds (standard deviation (SD) = 77). Neither the ambient temperature nor humidity were found to affect the pressure cooker's time to achieve adequate pressure, nor the achieved depth on the integrator strip (all p > .05). CONCLUSION: This study provides evidence that sterilization is possible with offthe- shelf pressure cookers. Though lacking US Food and Drug Administration (FDA) approval, the use of this commercially available pressure cooker may provide a method of sterilization requiring minimal resources from providers working in expeditionary environments.