The year 2015 is as far away in chronological time from 1965 as 1965 was from World War I. In other words, Lyndon Baines Johnson and ESEA are as remote and distant to our students as Archduke ...Ferdinand was to us in our school days. What seems to some of us like yesterday, or the start of a recent era, is in fact now a distant and remote time, seemingly unconnected from our present educational predicaments—at least in the eyes of our students. Or, to put it another way, ESEA is now fit for historical study.
The gram-negative bacterium
(
) is both a potential biological weapon and a naturally occurring microbe that survives in arthropods, fresh water amoeba, and mammals with distinct phenotypes in ...various environments. Previously, we used a number of measurements to characterize
grown in Brain-Heart Infusion (BHI) broth as (1) more similar to infection-derived bacteria, and (2) slightly more virulent in naïve animals, compared to
grown in Mueller Hinton Broth (MHB). In these studies we observed that the free amino acids in MHB repress expression of select
virulence factors by an unknown mechanism. Here, we tested the hypotheses that
grown in BHI (BHI-
) accurately displays a full protein composition more similar to that reported for infection-derived
and that this similarity would make BHI-
more susceptible to pre-existing, vaccine-induced immunity than MHB-
. We performed comprehensive proteomic analysis of
grown in MHB, BHI, and BHI supplemented with casamino acids (BCA) and compared our findings to published "omics" data derived from
grown
. Based on the abundance of ~1,000 proteins, the fingerprint of BHI-
is one of nutrient-deprived bacteria that-through induction of a stringent-starvation-like response-have induced the FevR regulon for expression of the bacterium's virulence factors, immuno-dominant antigens, and surface-carbohydrate synthases. To test the notion that increased abundance of dominant antigens expressed by BHI-
would render these bacteria more susceptible to pre-existing, vaccine-induced immunity, we employed a battery of LVS-vaccination and S4-challenge protocols using MHB- and BHI-grown
S4. Contrary to our hypothesis, these experiments reveal that LVS-immunization provides a barrier to infection that is significantly more effective against an MHB-S4 challenge than a BHI-S4 challenge. The differences in apparent virulence to immunized mice are profoundly greater than those observed with primary infection of naïve mice. Our findings suggest that tularemia vaccination studies should be critically evaluated in regard to the growth conditions of the challenge agent.
Tularemia is a severe, zoonotic infection caused by the Gram-negative bacterium
. Inhalation results in a rapid, severe bacterial pneumonia and sepsis, which can be lethal. Because the cynomolgus ...macaque is the accepted nonhuman primate model for tularemia, we conducted a natural history study of pneumonic tularemia by exposing macaques to target inhaled doses of 50, 500, or 5000 colony forming units (CFU) of
subsp. tularensis SCHU S4. Two animals within the 50 CFU group (calculated doses of 10 and 11 CFU) survived the challenge, while the remainder succumbed to infection. Exposure of cynomolgus macaques to aerosolized SCHU S4 resulted in fever, anorexia, increased white blood cell counts, lymphopenia, thrombocytopenia, increased liver enzymes, alterations in electrocardiogram (ECG), and pathological changes typical of infection with
, regardless of the challenge dose. Blood pressure dropped during the febrile phase, particularly as temperature began to drop and macaques succumbed to the disease. ECG analysis indicated that in 33% of the macaques, heart rate was not elevated during the febrile phase (Faget's sign; pulse-temperature disassociation), which has been reported in a similar percentage of human cases. These results indicated that infection of cynomolgus macaques with aerosolized
results in similar disease progression and outcome as seen in humans, and that cynomolgus macaques are a reliable animal model to test medical countermeasures against aerosolized
.
Highly pathogenic avian influenza A H5N1 viruses cause high mortality in humans and have pandemic potential. Effective vaccines and treatments against this threat are urgently needed. Here, we have ...refined our previously established model of lethal H5N1 infection in cynomolgus macaques. An inhaled aerosol virus dose of 5.1 log10 plaque-forming unit (pfu) induced a strong febrile response and acute respiratory disease, with four out of six macaques succumbing after challenge. Vaccination with three doses of adjuvanted seasonal quadrivalent influenza vaccine elicited low but detectable neutralizing antibody to H5N1. All six vaccinated macaques survived four times the 50% lethal dose of aerosolized H5N1, while four of six unvaccinated controls succumbed to disease. Although vaccination did not protect against severe influenza, vaccinees had reduced respiratory dysfunction and lower viral load in airways compared to controls. We anticipate that our macaque model will play a vital role in evaluating vaccines and antivirals against influenza pandemics.
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•Refined the H5N1 aerosol macaque model of lethal influenza•Lower virus doses did not extend the disease course•Three doses of licensed quadrivalent influenza vaccine plus adjuvant protected against death•Pre-challenge neutralizing antibody titers correlated with protection
Immunology; Virology; Model organism
Infection with Ebola virus (EBOV) causes a fulminant and often fatal hemorrhagic fever. In order to improve our understanding of EBOV pathogenesis and EBOV-host interactions, we examined the ...molecular features of EBOV infection in vivo.
Using high-density cDNA microarrays, we analyzed genome-wide host expression patterns in sequential blood samples from nonhuman primates infected with EBOV. The temporal program of gene expression was strikingly similar between animals. Of particular interest were features of the data that reflect the interferon response, cytokine signaling, and apoptosis. Transcript levels for tumor necrosis factor-alpha converting enzyme (TACE)/alpha-disintegrin and metalloproteinase (ADAM)-17 increased during days 4 to 6 after infection. In addition, the serum concentration of cleaved Ebola glycoprotein (GP2 delta) was elevated in late-stage EBOV infected animals. Of note, we were able to detect changes in gene expression of more than 300 genes before symptoms appeared.
These results provide the first genome-wide ex vivo analysis of the host response to systemic filovirus infection and disease. These data may elucidate mechanisms of viral pathogenesis and host defense, and may suggest targets for diagnostic and therapeutic development.
Pneumonic tularemia is a highly debilitating and potentially fatal disease caused by inhalation of Francisella tularensis. Most of our current understanding of its pathogenesis is based on the highly ...virulent F. tularensis subsp. tularensis strain SCHU S4. However, multiple sources of SCHU S4 have been maintained and propagated independently over the years, potentially generating genetic variants with altered virulence. In this study, the virulence of four SCHU S4 stocks (NR-10492, NR-28534, NR-643 from BEI Resources and FTS-635 from Battelle Memorial Institute) along with another virulent subsp. tularensis strain, MA00-2987, were assessed in parallel. In the Fischer 344 rat model of pneumonic tularemia, NR-643 and FTS-635 were found to be highly attenuated compared to NR-10492, NR-28534, and MA00-2987. In the NZW rabbit model of pneumonic tularemia, NR-643 caused morbidity but not mortality even at a dose equivalent to 500x the LD50 for NR-10492. Genetic analyses revealed that NR-10492 and NR-28534 were identical to each other, and nearly identical to the reference SCHU S4 sequence. NR-643 and FTS-635 were identical to each other but were found to have nine regions of difference in the genomic sequence when compared to the published reference SCHU S4 sequence. Given the genetic differences and decreased virulence, NR-643/FTS-635 should be clearly designated as a separate SCHU S4 substrain and no longer utilized in efficacy studies to evaluate potential vaccines and therapeutics against tularemia.
Purpose Operating room (OR) guidance is important for surgical residents’ performance and, ultimately, for the development of independence and autonomy. This study explores the differences in ...surgical residents’ and attending surgeons’ perceptions of OR guidance in prerecorded surgical cases. Methods A total of 9 attending surgeons and 8 surgical residents observed 8 prerecorded surgical cases and were asked to identify both the presence and the type of attending surgeons’ OR guidance. Each recorded case was observed by 2 attending surgeons and 1 resident. A previously developed taxonomy for types of OR guidance was applied to analyze the data to explore the difference. Agreement by both attending surgeons on the presence and the type of OR guidance served as the concordant guidance behaviors to which the responses of the residents were compared. Results Overall, 116 OR guidance events were identified. Attending surgeons agreed on the presence of guidance in 80 of 116 (69.8%) events and consistently identified the type of OR guidance in 91.4% (73/80, Cohen κ = 0.874) of them. However, surgical residents only agreed with attending surgeons on the presence of guidance in 61.25% (49/80) of the events. In addition, there was significant disagreement (Cohen κ = 0.319) between surgical residents and attending surgeons in the type of OR guidance; the residents only identified 54.8% (40/73) of concordant guidance behaviors in the same guidance category as both the surgeons. Among the types of OR guidance, residents and attending surgeons were most likely to agree on the teaching guidance (66.67%) and least likely to agree on the assisting guidance (36.84%). Conclusions Surgical residents and attending surgeons have different perceptions of both the presence and the type of OR guidance. This difference in perception of OR guidance has important implications for the efficiency of training surgical residents in the OR, and, ultimately on residents’ development of independence and autonomy.
Rift Valley fever (RVF) is an emerging arboviral disease affecting both humans and livestock. In humans, RVF displays a spectrum of clinical manifestations, including encephalitis. To date, there are ...no FDA-approved vaccines or therapeutics for human use, although several are in pre-clinical development. Few small animal models of RVF encephalitis exist, further complicating countermeasure assessment. Human mAbs RVFV-140, RVFV-268 and RVFV-379 are recombinant potently neutralizing antibodies that prevent infection by binding the RVFV surface glycoproteins. Previous studies showed that both RVFV-268 and RVFV-140 improve survival in a lethal mouse model of disease, and RVFV-268 has prevented vertical transmission in a pregnant rat model of infection. Despite these successes, evaluation of mAbs in the context of brain disease has been limited. This is the first study to assess neutralizing antibodies for prevention of RVF neurologic disease using a rat model. Administration of RVFV-140, RVFV-268, or RVFV-379 twenty-four hours prior to aerosol exposure to the virulent ZH501 strain of RVFV results in substantially enhanced survival and lack of neurological signs of disease. These results using a stringent and highly lethal aerosol infection model supports the potential use of human mAbs to prevent the development of RVF encephalitis.Rift Valley fever (RVF) is an emerging arboviral disease affecting both humans and livestock. In humans, RVF displays a spectrum of clinical manifestations, including encephalitis. To date, there are no FDA-approved vaccines or therapeutics for human use, although several are in pre-clinical development. Few small animal models of RVF encephalitis exist, further complicating countermeasure assessment. Human mAbs RVFV-140, RVFV-268 and RVFV-379 are recombinant potently neutralizing antibodies that prevent infection by binding the RVFV surface glycoproteins. Previous studies showed that both RVFV-268 and RVFV-140 improve survival in a lethal mouse model of disease, and RVFV-268 has prevented vertical transmission in a pregnant rat model of infection. Despite these successes, evaluation of mAbs in the context of brain disease has been limited. This is the first study to assess neutralizing antibodies for prevention of RVF neurologic disease using a rat model. Administration of RVFV-140, RVFV-268, or RVFV-379 twenty-four hours prior to aerosol exposure to the virulent ZH501 strain of RVFV results in substantially enhanced survival and lack of neurological signs of disease. These results using a stringent and highly lethal aerosol infection model supports the potential use of human mAbs to prevent the development of RVF encephalitis.
Eastern (EEEV) and Venezuelan (VEEV) equine encephalitis viruses (EEVs) are related, (+) ssRNA arboviruses that can cause severe, sometimes fatal, encephalitis in humans. EEVs are highly infectious ...when aerosolized, raising concerns for potential use as biological weapons. No licensed medical countermeasures exist; given the severity/rarity of natural EEV infections, efficacy studies require animal models. Cynomolgus macaques exposed to EEV aerosols develop fever, encephalitis, and other clinical signs similar to humans. Fever is nonspecific for encephalitis in macaques. Electrocardiography (ECG) metrics may predict onset, severity, or outcome of EEV-attributable disease. Macaques were implanted with thermometry/ECG radiotransmitters and exposed to aerosolized EEV. Data was collected continuously, and repeated-measures ANOVA and frequency-spectrum analyses identified differences between courses of illness and between pre-exposure and post-exposure states. EEEV-infected macaques manifested widened QRS-intervals in severely ill subjects post-exposure. Moreover, QT-intervals and RR-intervals decreased during the febrile period. VEEV-infected macaques suffered decreased QT-intervals and RR-intervals with fever onset. Frequency-spectrum analyses revealed differences in the fundamental frequencies of multiple metrics in the post-exposure and febrile periods compared to baseline and confirmed circadian dysfunction. Heart rate variability (HRV) analyses revealed diminished variability post-exposure. These analyses support using ECG data alongside fever and clinical laboratory findings for evaluating medical countermeasure efficacy.
We investigated attending surgeon decisions regarding resident operative autonomy, including situations where operative autonomy was discordant with performance quality.
Attending surgeons assessed ...operative performance and documented operative autonomy granted to residents from 14 general surgery residency programs. Concordance between performance and autonomy was defined as “practice ready performance/meaningfully autonomous” or “not practice ready/not meaningfully autonomous.” Discordant circumstances were practice ready/not meaningfully autonomous or not practice ready/meaningfully autonomous. Resident training level, patient-related case complexity, procedure complexity, and procedure commonality were investigated to determine impact on autonomy.
A total of 8,798 assessments were collected from 429 unique surgeons assessing 496 unique residents. Practice-ready and exceptional performances were 20 times more likely to be performed under meaningfully autonomous conditions than were other performances. Meaningful autonomy occurred most often with high-volume, easy and common cases, and less complex procedures. Eighty percent of assessments were concordant (38% practice ready/meaningfully autonomous and 42% not practice ready/not meaningfully autonomous). Most discordant assessments (13.8%) were not practice ready/meaningfully autonomous. For fifth-year residents, practice ready/not meaningfully autonomous ratings (9.7%) were more frequent than not practice ready/meaningfully autonomous ratings (7.5%). Ten surgeons (2.3%) failed to afford residents meaningful autonomy on any occasion.
Resident operative performance quality is the most important determinant in attending surgeon decisions regarding resident autonomy.
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