Evaluation of dendrimer SPL7013, a lead microbicide candidate against herpes simplex viruses.

Dendrimers are a novel class of polyanionic macromolecules with broad-spectrum antiviral activities and minimal toxicities. A new generation of amide dendrimer, SPL7013, was evaluated as a lead microbicide candidate against herpes simplex viruses (HSV). The plaque reduction assays showed that the 50% effective concentrations (EC(50)) determined by pre-treatment of cells were 2.0 microg/ml for HSV-1 and 0.5 microg/ml for HSV-2. Inhibitory effects were also observed on HSV-infected cells with EC(50)s of 6.1 microg/ml for HSV-1 and 3.8 microg/ml for HSV-2. These are the mean values from the test results of six batches of SPL7013. SPL7013 was also shown to be equally potent against HSV drug-resistant strains. SPL7013 completely inhibited viral adsorption to Vero cells at concentrations of higher than 3 microg/ml. Analyzed by a LightCycler assay after treatment of HSV-infected cells for 17 h, SPL7013 showed strong inhibition of HSV DNA synthesis with EC(50)s of approximately 6.2 and 2.0 microg/ml for HSV-1 and HSV-2, respectively. SPL7013 retained its anti-HSV activity even after treatment at acidic pHs 3.0 and 4.0 for 2 h. The presence of 10% human serum proteins did not affect the anti-HSV activity of SPL7013. SPL7013 was not toxic to Vero cells up to the highest concentration tested (10,000 microg/ml). Effects on cell proliferation were tested on two epithelial cell lines in both stationary and dividing phases. The 50% cytotoxic concentrations (CC(50)) in all cases were greater than 10,000 microg/ml. Our data indicate that SPL7013 is a promising candidate for development as a vaginal microbicide and a therapeutic agent.

Walking donor transfusion in a far forward environment.

This case report details the walking donor transfusion (WDT) option for management of exsanguinating hemorrhage performed in an austere environment. It has civilian application in situations in which local blood supply is overwhelmed by demand due to a natural or manmade (ie, terrorist) disaster. WDT is discussed in light of alternative transfusion techniques, and the history of WDT is briefly discussed. Walking donor transfusion is appropriate for use in extreme cases of patient exsanguination.

Enteral nutrition by a forward surgical team in Afghanistan.

OBJECTIVES: The modern practice of trauma surgery is a global physiologic approach to caring for the injured patient. Included in that approach is consideration of the traumatized patient's nutritional needs and implementing early enteral feeding. This is routine practice in the United States but logistically impractical when using commercial enteral feeding formulas in the austere environment of a Forward Operating Base in Afghanistan. METHODS: At a Forward Operating Base in southern Afghanistan, injured patients who were not expected to be taking a regular diet by 72 hours after injury are started on early enteral feedings. This is through nasogastric, gastrostomy, or jejunostomy tube, using formulas of pureed food available in the theater from local sources and supplemented with ingredients from US Army Meals-Ready-to-Eat. Preparation, nutritional calculation, and delivery are discussed. RESULTS: The injured soldiers and Afghan nationals tolerated early enteral feedings with no complications encountered related to the feeding portal, infusion, or ingredients. CONCLUSIONS: Early enteral feeding of traumatized patients in the far forward environment of southeastern Afghanistan is practical with the use of ingredients found locally in-theater.

Evidence of dual sites of action of dendrimers: SPL-2999 inhibits both virus entry and late stages of herpes simplex virus replication.

Dendrimers are macromolecules with broad-spectrum antiviral activity and minimal toxicity effective in animal models in preventing transmission of herpes simplex virus (HSV) infection. In order to further understand the mechanism of action, and toxicity profiles of the dendrimer SPL-2999 against HSV, we investigated in vitro activities as follows: modified plaque reduction assays for SPL-2999 showed that 50% effective concentrations (EC(50)) determined by pre-treatment of cells with SPL-2999 were 0.5 microg/ml (30 nM) for HSV-2 and 1 microg/ml (60 nM) for HSV-1, respectively. SPL-2999 was not toxic to Vero cells at concentration up to the highest tested (CC(50) greater than 1000 microg/ml). SPL-2999 appears to completely inhibit both viral adsorption and penetration to Vero cells at concentrations of higher than 3 microg/ml. Additionally, virus yield reduction assay showed that SPL-2999 was effective on cells already infected with HSV with EC(90)s (effective concentration giving 90% virus yield reduction) approximately 29.2 microg/ml for HSV-1 and 6.7 microg/ml for HSV-2. When Vero cells were infected with HSV at moi (multiplicity of infection) of 0.01 pfu/cell, the infected cells could be completely protected from viral cytopathic effect (CPE) by SPL-2999 with EC(90)s (effective concentration that protects 90% of cells from virus lysis) of 15 microg/ml for HSV-1 and 10 microg/ml for HSV-2. Results from Southern blot hybridization indicated that SPL-2999 inhibited DNA synthesis in HSV infected cells. We conclude that SPL-2999 inhibits both HSV entry into susceptible cells and late stages of HSV replication. Our data indicate that SPL-2999 is a potent inhibitor of both HSV-1 and -2 with the potential for further development as either a topical microbicide or a therapeutic agent.