Translational repression mediates activation of nuclear factor kappa B by phosphorylated translation initiation factor 2

Numerous stressful conditions activate kinases that phosphorylate the alpha subunit of translation initiation factor 2 (eIF2alpha), thus attenuating mRNA translation and activating a gene expression program known as the integrated stress response. It has been noted that conditions associated with eIF2alpha phosphorylation, notably accumulation of unfolded proteins in the endoplasmic reticulum (ER), or ER stress, are also associated with activation of nuclear factor kappa B (NF-kappaB) and that eIF2alpha phosphorylation is required for NF-kappaB activation by ER stress. We have used a pharmacologically activable version of pancreatic ER kinase (PERK, an ER stress-responsive eIF2alpha kinase) to uncouple eIF2alpha phosphorylation from stress and found that phosphorylation of eIF2alpha is both necessary and sufficient to activate both NF-kappaB DNA binding and an NF-kappaB reporter gene. eIF2alpha phosphorylation-dependent NF-kappaB activation correlated with decreased levels of the inhibitor IkappaBalpha protein. Unlike canonical signaling pathways that promote IkappaBalpha phosphorylation and degradation, eIF2alpha phosphorylation did not increase phosphorylated IkappaBalpha levels or affect the stability of the protein. Pulse-chase labeling experiments indicate instead that repression of IkappaBalpha translation plays an important role in NF-kappaB activation in cells experiencing high levels of eIF2alpha phosphorylation. These studies suggest a direct role for eIF2alpha phosphorylation-dependent translational control in activating NF-kappaB during ER stress.     

Flap perfusion mapping: TRAM flap after abdominal suction-assisted lipectomy

This technique or its modification (using other dyes) may play a beneficial role in other clinical scenarios where the reconstructive plastic surgeon preoperatively needs to know the integrity of vessels that are too small to image using standard angiographic techniques. In addition, flap perfusion mapping can demonstrate the pattern of skin that is physiologically perfused by the intact vessels. Knowledge of the perfusion characteristics of the tissues to be transferred before surgery may, at the least, alter the design of the tissues to be transferred and, in the extreme case, could affect the nature of the operative choice altogether.     

Sequence analysis of plasmid pTS1 isolated from oral spirochetes

The naturally occurring plasmid pTS1, identified previously in several species of oral spirochetes, has now been completely sequenced. Analysis of the four open reading frames identified on the plasmid suggests the presence of genes involved in replication and mobilization.     

Feasibility study of repeated harvesting of menthol from biologically viable Mentha x piperata using ultrasonic extraction

To potentially replace the conventional destructive extraction process, we have shown the feasibility of devising a novel technique that uses ultrasound to nonlethally and repeatedly extract menthol from biologically viable peppermint plants (Mentha x piperita). Our results show that plants ultrasonicated for 1 h at 22 degrees C in a standard 40 kHz ultrasonic bath could release approximately 17.8 microg of menthol per gram of leaf tissue (2% of total product). The amount of menthol release increases with the time of treatment and is greatly affected by the temperature of the ultrasonic bath water. An increase from 2% to 12% of total product was observed when the temperature was increased from 22 degrees C to 39 degrees C. When the temperature effects were isolated, the mechanism of the product release was found to be that of cavitation. The treated plants remained viable and were ready for the subsequent ultrasound extraction after approximately 4 days of recuperation. However, the amount of product released is reduced in subsequent extractions. Scanning electron micrographs indicate that there are two mechanisms involved in extraction: (1) the diffusion of product through the cuticle of peppermint glandular trichomes and (2) the exudation of the product from broken and damaged trichomes. This study has shown the possibility of using an on-line ultrasonic, nondestructive extraction method to continuously release intracellular plant metabolites from the plants while maintaining the plant's viability.     

Molecular analysis of Vibrio parahaemolyticus isolated from human patients and shellfish during US Pacific north-west outbreaks

AIMS: The objective of this study was to investigate the occurrence and distribution of haemolysin genes, plasmid profile, serogroup analysis and cellular urease activity for Vibrio parahaemolyticus isolates from infected human patients and oysters from the Pacific north-western United States between 1988 and 1997. METHODS AND RESULTS: All of the clinical and environmental isolates tested in this study exhibited the presence of the thermolabile haemolysin gene, tl, confirming that all of the isolates were V. parahaemolyticus. Furthermore, the V. parahaemolyticus isolates that contained either the thermostable direct haemolysin gene, tdh, or the thermostable direct haemolysin-related gene, trh, or both, were also positive for urease. Isolates from infected human patients belong to serogroups O1 and O4, whereas, the isolates from oysters belong to serogroups O1, O4 and O5. These results suggest that the presence of a V. parahaemolyticus serogroup O1 and O4 could indicate the presence of a virulent strain of this pathogen. In this study, the presence of the haemolysin genes, serogroup profiles and urease production in V. parahaemolyticus isolated from human patients correlated with the oysters collected during the outbreaks. However, no significant correlation of the plasmid profiles was detected, based on their distribution and molecular weights, between V. parahaemolyticus isolated from infected human patients and from oysters collected during this outbreak. CONCLUSIONS, SIGNIFICANCE AND IMPACT OF STUDY: It is apparent from this study that the identification of the haemolysin genes by multiplex PCR amplification, in conjunction with serogroup analysis and urease production, can be used to monitor shellfish for the presence of potentially pathogenic strains of V. parahaemolyticus.