Efficacy of different AV7909 dose regimens in a nonclinical model of pulmonary anthrax

Pulmonary anthrax caused by exposure to inhaled Bacillus anthracis, the most lethal form of anthrax disease, is a continued military and public health concern for the United States. The vaccine AV7909, consisting of the licensed anthrax drug substance AVA adjuvanted with CpG7909, induces high levels of toxin neutralizing antibodies in healthy adults using fewer doses than AVA. This study compares the ability of one- or two-dose regimens of AV7909 to induce a protective immune response in guinea pigs challenged with a lethal dose of aerosolized B. anthracis spores 6 weeks after the last vaccine dose. The results indicated that AV7909 was less effective when delivered as a single dose compared to the two-dose regimen that resulted in dose-dependent protection against death. The toxin neutralizing assay (TNA) titer and anti-PA IgG responses were proportional to the protective efficacy, with a 50% TNA neutralizing factor (NF50) greater than 0.1 associated with survival in animals receiving two doses of vaccine. The strong protection at relatively low TNA NF50 titers in this guinea pig model supports the exploration of lower doses in clinical trials to determine if these protective levels of neutralizing antibodies can be achieved in humans; however, protection with a single dose may not be feasible.

Survey of Premium Versus Large Manufactured Cigars Use in U.S. Consumers

INTRODUCTION

An Internet questionnaire was used to determine smoking behavior, purchasing behavior, and risk perceptions among exclusive or nearly exclusive current users of either large manufactured (LMC) or premium cigars (PC).

AIMS AND METHODS

Respondents (n = 250) were recruited from a nationally representative market research panel. An a priori designation of PC users was adapted from criteria in published literature and the recent National Academy of Science report.

RESULTS

Examination of responses revealed a (n = 19) disagreement between cigar users' self-classifications and the a priori classification. After eliminating ineligible respondents 188 participants were classified as PC (n = 92; 55 male) or LMC (n = 96; 49 male) users. There were no significant differences in age or gender between groups. Respondents were all over 21 years old. The largest age groups were 30-39 years and 60-69 years. PC users were significantly more likely to have higher annual incomes and to buy cigars online or through tobacco specialty shops, whereas LMC users purchased from convenience stores. Most participants had used other combustible tobacco products (88%) but few had used ENDS (24%) or oral tobacco (7.5%). There was no significant difference in the frequency of smoke inhalation or perceptions of risk for health. There was marked uncertainty in self-characterization of cigar type; our sample had higher female representation than expected (n = 84, 45%), and inhalation was frequently endorsed in both groups (52%, overall).

CONCLUSIONS

The results support the need for standardized classifications and suggest current trends may indicate shifts in gender and use behavior but provide no evidence supporting less restrictive regulation of PC.

IMPLICATIONS

An Internet questionnaire was used to determine smoking behavior, purchasing behavior, and risk perceptions among current users of LMC or PC. There was uncertainty about cigar classification even in this sample of regular users. Our results demonstrated more than expected inhalation of cigar smoke, considerable use by females, and under appreciation of health risks. No results supported less restrictive regulations for premium cigars.

A novel sulfur mustard (HD) vapor inhalation exposure model of pulmonary toxicity for the efficacy evaluation of candidate medical countermeasures

OBJECTIVE

To develop a novel inhalation exposure system capable of delivering a controlled inhaled HD dose through an endotracheal tube to anesthetized rats to investigate the lung pathophysiology and evaluate potential medical countermeasures.

MATERIALS AND METHODS

Target HD vapor exposures were generated by a temperature-controlled vapor generator, while concentration was monitored near real-time by gas chromatography. Animal breathing parameters were monitored real-time by in-line EMKA/SciReq pulmonary analysis system. Individual exposures were halted when the target inhaled doses were achieved. Animals were observed daily for clinical observations and lethality with scheduled termination at 28 days post-exposure. Upon scheduled or unscheduled death, animals underwent a gross necropsy and lung and trachea were collected for histopathology.

RESULTS

Controlled HD concentrations ranged from 60 to 320 mg/m³. Delivered inhaled doses range from 0.3 to 3.20 mg/kg with administered doses within 3% of the target. The 28-day inhaled LD₅₀ is 0.80 mg/kg (95% CI = 0.42-1.18 mg/kg). Post exposure respiratory abnormalities were observed across all dose levels though the higher dose levels had earlier onset and higher frequency of occurrence. Histopathologic alterations were not qualitatively altered in accordance with dose but instead showed a relationship to an animals' time of death, with early deaths demonstrating acute damage and later deaths displaying signs of repair.

DISCUSSION/CONCLUSION

This novel exposure system administers targeted HD inhaled doses to generate a small animal model that can be used to evaluate physiological toxicities of inhaled HD on the lungs and for evaluation of potential medical countermeasure treatments.

Mucosal Challenge Ferret Models of Ebola Virus Disease

Recent studies have shown the domestic ferret (Mustela putorius furo) to be a promising small animal model for the study of Ebola virus (EBOV) disease and medical countermeasure evaluation. To date, most studies have focused on traditional challenge routes, predominantly intramuscular and intranasal administration. Here, we present results from a non-clinical pathogenicity study examining oronasal, oral, and ocular mucosal challenge routes in ferrets. Animals were challenged with 1, 10, or 100 plaque forming units EBOV followed by monitoring of disease progression and biosampling. Ferrets administered virus via oronasal and oral routes met euthanasia criteria due to advanced disease 5–10 days post-challenge. Conversely, all ferrets dosed via the ocular route survived until the scheduled study termination 28-day post-challenge. In animals that succumbed to disease, a dose/route response was not observed; increases in disease severity, febrile responses, serum and tissue viral load, alterations in clinical pathology, and gross/histopathology findings were similar between subjects. Disease progression in ferrets challenged via ocular administration was unremarkable throughout the study period. Results from this study further support the ferret as a model for EBOV disease following oral and nasal mucosa exposure.

Assessment of Genetic Markers for Tracking the Sources of Human Wastewater Associated Escherichia coli in Environmental Waters

In this study, we have evaluated the performance characteristics (host-specificity and -sensitivity) of four human wastewater-associated Escherichia coli (E. coli) genetic markers (H8, H12, H14, and H24) in 10 target (human) and nontarget (cat, cattle, deer, dog, emu, goat, horse, kangaroo, and possum) host groups in Southeast Queensland, Australia. The overall host-sensitivity values of the tested markers in human wastewater samples were 1.0 (all human wastewater samples contained the E. coli genetic markers). The overall host-specificity values of these markers to differentiate between human and animal host groups were 0.94, 0.85, 0.72, and 0.57 for H8, H12, H24, and H14, respectively. Based on the higher host-specificity values, H8 and H12 markers were chosen for a validation environmental study. The prevalence of the H8 and H12 markers was determined among human wastewater E. coli isolates collected from a wastewater treatment plant (WWTP). Among the 97 isolates tested, 44 (45%) and 14 (14%) were positive for the H8 and H12 markers, respectively. A total of 307 E. coli isolates were tested from environmental water samples collected in Brisbane, of which 7% and 20% were also positive for the H8 and H12 markers, respectively. Based on our results, we recommend that these markers could be useful when it is important to identify the source(s) of E. coli (whether they originated from human wastewater or not) in environmental waters.

Possible role for human papillomavirus 16 in squamous cell carcinoma of the finger

There are about 20 types of human papillomaviruses (HPVs) which are generally believed to be confined to the anogenital tract. HPV 16 is the most common of these. Four squamous cell carcinomas of the finger from three individuals were analyzed for the presence of HPV DNA by Pst 1 restriction enzyme digest and Southern blotting. Under high stringency conditions, all were positive for HPV 16. The DNA from each patient was digested with a panel of restriction enzymes so that integration of HPV into the genome could be evaluated. Three of three samples contained high molecular weight oligomeric circular DNA arranged as catanates. None showed integration. To determine if the HPV was transcriptionally active, RNA was isolated, reverse transcribed, and amplified using primers that amplified the unspliced E6 transcript and the E6I and E6II spliced transcripts. All of the patient biopsies assayed expressed the unspliced E6 transcript and the spliced E6I transcript with the E6I transcript being the most abundant. The E6II transcript was not detected in any of the samples. These findings indicate that HPV plays a role in the development of squamous cell carcinoma of the finger and the role of the malignant genital HPV needs to be carefully looked at in areas outside the genital region. It also suggests that the natural history of HPV in areas outside the cervix may not be identical to that of HPV in the anogenital region.