scholarly journals Development, Characterization, and Standardization of a Nose-Only Inhalation Exposure System for Exposure of Rabbits to Small-Particle Aerosols ContainingFrancisella tularensis

2019 ◽  
Vol 87 (8) ◽  
Author(s):  
Katherine J. O’Malley ◽  
Jennifer D. Bowling ◽  
Eileen M. Barry ◽  
Karsten R. O. Hazlett ◽  
Douglas S. Reed
Keyword(s):  
Weight Loss ◽  
Median Survival ◽  
Bacterial Culture ◽  
Severe Disease ◽  
Inhalation Exposure ◽  
Brain Heart Infusion ◽  
Survival Times ◽  
Exposure System ◽  
Content Type ◽  
Schu S4

ABSTRACTInhalation ofFrancisella tularensiscauses pneumonic tularemia in humans, a severe disease with a 30 to 60% mortality rate. The reproducible delivery of aerosolized virulent bacteria in relevant animal models is essential for evaluating medical countermeasures. Here we developed optimized protocols for infecting New Zealand White (NZW) rabbits with aerosols containingF. tularensis. We evaluated the relative humidity, aerosol exposure technique, and bacterial culture conditions to optimize the spray factor (SF), a central metric of aerosolization. This optimization reduced both inter- and intraday variability and was applicable to multiple isolates ofF. tularensis. Further improvements in the accuracy and precision of the inhaled pathogen dose were achieved through enhanced correlation of the bacterial culture optical density and the number of CFU. Plethysmograph data collected during exposures found that respiratory function varied considerably between rabbits, was not a function of weight, and did not improve with acclimation to the system. Live vaccine strain (LVS)-vaccinated rabbits were challenged via aerosol with human-virulentF. tularensisSCHU S4 that had been cultivated in either Mueller-Hinton broth (MHB) or brain heart infusion (BHI) broth. LVS-vaccinated animals challenged with SCHU S4 that had been cultivated in MHB experienced short febrile periods (median, 3.2 days), limited weight loss (<5%), and longer median survival times (∼18 days) that were significantly different from those for unvaccinated controls. In contrast, LVS-vaccinated rabbits challenged with SCHU S4 that had been cultivated in BHI experienced longer febrile periods (median, 5.5 days) and greater weight loss (>10%) than the unvaccinated controls and median survival times that were not significantly different from those for the unvaccinated controls. These studies highlight the importance of careful characterization and optimization of protocols for aerosol challenge with pathogenic agents.

scholarly journals Development, characterization and standardization of a nose-only inhalation exposure system for exposure of rabbits to small particle aerosols containingFrancisella tularensis

2019 ◽  
Author(s):  
Katherine J. O’ Malley ◽  
Jennifer D. Bowling ◽  
Eileen M. Barry ◽  
Karsten R. O. Hazlett ◽  
Douglas S. Reed
Keyword(s):  
Weight Loss ◽  
Median Survival ◽  
Bacterial Culture ◽  
Severe Disease ◽  
Inhalation Exposure ◽  
Brain Heart Infusion ◽  
Culture Conditions ◽  
Survival Times ◽  
Exposure System ◽  
Schu S4

ABSTRACTInhalation ofFrancisella tularensis(Ft) causes pneumonic tularemia in humans, a severe disease with a 30-60% mortality rate. Reproducible delivery of aerosolized virulent bacteria in relevant animal models is essential for evaluating medical countermeasures. Here we developed optimized protocols for infecting New Zealand White (NZW) rabbits with aerosols containingFt. We evaluated relative humidity, aerosol exposure technique, and bacterial culture conditions to optimize spray factor (SF), a central metric of aerosolization. This optimization reduced both inter-and intra-daily variability and were applicable to multiple isolates ofFt. Further improvements in the accuracy and precision of the inhaled pathogen dose were achieved through enhanced correlation of bacterial culture OD and CFU. Plethysmograph data collected during exposures found that respiratory function varied considerably between rabbits, was not a function of weight, and did not improve with acclimation to the system. Vaccine Strain (LVS)-vaccinated rabbits were challenged via aerosol with human-virulentFtSCHU S4 that had been cultivated in either Mueller Hinton Broth (MHB) or Brain Heart Infusion (BHI) broth. LVS-vaccinated animals challenged with MHB-SCHU S4 experienced short febrile periods (median: 3.2 days), limited weight loss (< 5%), and longer median survival times (~18 d) that were significantly different than unvaccinated controls. In contrast, LVS-vaccinated rabbits challenged with BHI SCHU S4 experienced longer febrile periods (median: 5.5 days), greater weight loss (> 10%), and median survival times that were not significantly different than unvaccinated controls. These studies highlight the importance of careful characterization and optimization of protocols for aerosol challenge with pathogenic agents.

scholarly journals Generation and Characterization of Indoor Fungal Aerosols for Inhalation Studies

2016 ◽  
Vol 82 (8) ◽  
pp. 2479-2493 ◽  
Author(s):  
Anne Mette Madsen ◽  
Søren T. Larsen ◽  
Ismo K. Koponen ◽  
Kirsten I. Kling ◽  
Afnan Barooni ◽  
...  
Keyword(s):  
Species Composition ◽  
Indoor Environment ◽  
Building Materials ◽  
Inhalation Exposure ◽  
Single Species ◽  
Fungal Species ◽  
Exposure Level ◽  
Exposure System ◽  
Content Type ◽  
Water Damage

ABSTRACTIn the indoor environment, people are exposed to several fungal species. Evident dampness is associated with increased respiratory symptoms. To examine the immune responses associated with fungal exposure, mice are often exposed to a single species grown on an agar medium. The aim of this study was to develop an inhalation exposure system to be able to examine responses in mice exposed to mixed fungal species aerosolized from fungus-infested building materials. Indoor airborne fungi were sampled and cultivated on gypsum boards. Aerosols were characterized and compared with aerosols in homes. Aerosols containing 107CFU of fungi/m3air were generated repeatedly from fungus-infested gypsum boards in a mouse exposure chamber. Aerosols containedAspergillus nidulans,Aspergillus niger,Aspergillus ustus,Aspergillus versicolor,Chaetomium globosum,Cladosporiumherbarum,Penicillium brevicompactum,Penicillium camemberti,Penicillium chrysogenum,Penicillium commune,Penicillium glabrum,Penicillium olsonii,Penicillium rugulosum,Stachybotrys chartarum, andWallemia sebi. They were all among the most abundant airborne species identified in 28 homes. Nine species from gypsum boards and 11 species in the homes are associated with water damage. Most fungi were present as single spores, but chains and clusters of different species and fragments were also present. The variation in exposure level during the 60 min of aerosol generation was similar to the variation measured in homes. Through aerosolization of fungi from the indoor environment, cultured on gypsum boards, it was possible to generate realistic aerosols in terms of species composition, concentration, and particle sizes. The inhalation-exposure system can be used to study responses to indoor fungi associated with water damage and the importance of fungal species composition.

Synergism between BCNU and irradiation in the treatment of anaplastic gliomas

1979 ◽  
Vol 51 (5) ◽  
pp. 581-586 ◽  
Author(s):  
Paul Steinbok ◽  
M. Stephen Mahaley ◽  
Raymond U ◽  
Douglas C. Zinn ◽  
Stan Lipper ◽  
...  
Keyword(s):  
Median Survival ◽  
Combined Therapy ◽  
Malignant Gliomas ◽  
Control Group ◽  
Therapeutic Effects ◽  
Survival Times ◽  
Content Type ◽  
Anaplastic Gliomas ◽  
In Series

✓ The therapeutic effects of irradiation, BCNU, or combined irradiation and BCNU were studied in the avian sarcoma virus (ASV)-induced glioma model in rats. Whole-head orthovoltage radiation therapy was given in six equal fractions over 2 weeks, and BCNU was administered intraperitoneally as a single dose of 10 mg/kg. Two series of experiments were performed in order to duplicate the results. In Series 1, the median survival times of the experimental groups, in days after randomization, were as follows: control group (no treatment), 69; group receiving 2000 rads, 84 (p < 0.05); group receiving BCNU, 80.5 (p < 0.1); and group receiving 2000 rads + BCNU, 112 (p < 0.001). In Series 2, the median survival times were: control group, 73.5; group receiving 2300 rads, 85 (p < 0.01); group receiving BCNU, 92.5 (p < 0.025); and group receiving 2300 rads + BCNU, 123.5 (p < 0.001). In both series, combined therapy was significantly better than either radiation or BCNU alone. This is the first time that a synergistic effect of BCNU and irradiation has been reported in an in vivo brain-tumor model and supports the clinical use of this combination in the treatment of malignant gliomas.

Vascular endothelial growth factor expression and vascular density as prognostic markers of survival in patients with low-grade astrocytoma

1998 ◽  
Vol 88 (3) ◽  
pp. 513-520 ◽  
Author(s):  
Saleem I. Abdulrauf ◽  
Klaus Edvardsen ◽  
Khang L. Ho ◽  
Xiao Yi Yang ◽  
Jack P. Rock ◽  
...  
Keyword(s):  
Growth Factor ◽  
Survival Time ◽  
Malignant Transformation ◽  
Median Survival ◽  
Median Survival Time ◽  
Tumor Tissue ◽  
Low Grade ◽  
Survival Times ◽  
Content Type ◽  
Fine Print

It has long been recognized that some patients with low-grade astrocytoma may survive for many years, whereas in others the disease follows a more malignant course resulting in a short survival time, usually due to malignant transformation into higher-grade tumors. Object. The aim of this study was to investigate angiogenesis in the initial biopsy specimen of tumor tissue as a biological marker to identify patients with low-grade astrocytoma who are at high risk of malignant tumor transformation or death. Methods. Tumor tissue was studied in 74 consecutively treated adult patients in whom a diagnosis of diffuse supratentorial hemispheric histologically proven fibrillary low-grade astrocytoma was made and who underwent surgery between January 1972 and January 1994. Studies were conducted using monoclonal antibodies to the antigens of the proliferation-associated Ki-67 (MIB-1), factor VIII, vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and epidermal growth factor (EGF). The overall 5-year survival rate for the entire patient population was 65%, with a median survival time of 7.5 years. The total mean follow-up period was 6.1 years. All tumors showed a low proliferative potential at the time of the initial operation, as demonstrated by an MIB-1 labeling index of less than 1.5%. Patients with more than seven microvessels in tumor tissue (29 cases) had a shorter survival time (mean 3.8 years) than those with seven or fewer microvessels (mean survival 11.2 years). This difference in survival times was significant by univariate (p = 0.001) and stepwise multivariate analyses (p < 0.001). Tumors with a larger number of microvessels also had a greater chance of undergoing malignant transformation (p = 0.001). Similarly, significant staining for VEGF was correlated with shorter survival times when using univariate (p = 0.003) and multivariate (p = 0.008) analyses and with a greater chance of malignant transformation (p = 0.002). Patients with tumors staining positive for VEGF (39 individuals) had a median survival time of 5.3 years, and those with tumors negative for VEGF (35 patients) had a median survival time of 11.2 years. No association was observed between bFGF, EGF, and survival or malignant transformation. The stepwise multivariate analysis included histological and clinical variables simultaneously. Conclusions. The authors have shown that microvessel density and VEGF levels are independent prognostic markers of survival in fibrillary low-grade astrocytoma. This finding leads them to propose that fibrillary diffuse low-grade astrocytoma is not a single pathological entity but is composed of a spectrum of tumors with differing propensities to undergo malignant transformation that is at least partly based on their inherent angiogenic potential.

scholarly journals Lethal Synergism of 2009 Pandemic H1N1 Influenza Virus and Streptococcus pneumoniae Coinfection Is Associated with Loss of Murine Lung Repair Responses

mBio ◽  
2011 ◽  
Vol 2 (5) ◽  
Author(s):  
John C. Kash ◽  
Kathie-Anne Walters ◽  
A. Sally Davis ◽  
Aline Sandouk ◽  
Louis M. Schwartzman ◽  
...  
Keyword(s):  
Weight Loss ◽  
Influenza Virus ◽  
Streptococcus Pneumoniae ◽  
Bacterial Infections ◽  
H1n1 Virus ◽  
Severe Disease ◽  
Significant Loss ◽  
Pandemic H1n1 ◽  
Content Type ◽  
Lung Repair

ABSTRACTSecondary bacterial infections increase disease severity of influenza virus infections and contribute greatly to increased morbidity and mortality during pandemics. To study secondary bacterial infection following influenza virus infection, mice were inoculated with sublethal doses of 2009 seasonal H1N1 virus (NIH50) or pandemic H1N1 virus (Mex09) followed by inoculation withStreptococcus pneumoniae48 h later. Disease was characterized by assessment of weight loss and survival, titration of virus and bacteria by quantitative reverse transcription-PCR (qRT-PCR), histopathology, expression microarray, and immunohistochemistry. Mice inoculated with virus alone showed 100% survival for all groups. Mice inoculated with Mex09 plusS. pneumoniaeshowed severe weight loss and 100% mortality with severe alveolitis, denuded bronchiolar epithelium, and widespread expression of apoptosis marker cleaved caspase 3. In contrast, mice inoculated with NIH50 plusS. pneumoniaeshowed increased weight loss, 100% survival, and slightly enhanced lung pathology. Mex09-S. pneumoniaecoinfection also resulted in increasedS. pneumoniaereplication in lung and bacteremia late in infection. Global gene expression profiling revealed that Mex09-S. pneumoniaecoinfection did not induce significantly more severe inflammatory responses but featured significant loss of epithelial cell reproliferation and repair responses. Histopathological examination for cell proliferation marker MCM7 showed significant staining of airway epithelial cells in all groups except Mex09-S. pneumoniae-infected mice. This study demonstrates that secondary bacterial infection during 2009 H1N1 pandemic virus infection resulted in more severe disease and loss of lung repair responses than did seasonal influenza viral and bacterial coinfection. Moreover, this study provides novel insights into influenza virus and bacterial coinfection by showing correlation of lethal outcome with loss of airway basal epithelial cells and associated lung repair responses.IMPORTANCESecondary bacterial pneumonias lead to increased disease severity and have resulted in a significant percentage of deaths during influenza pandemics. To understand the biological basis for the interaction of bacterial and viral infections, mice were infected with sublethal doses of 2009 seasonal H1N1 and pandemic H1N1 viruses followed by infection withStreptococcus pneumoniae48 h later. Only infection with 2009 pandemic H1N1 virus andS. pneumoniaeresulted in severe disease with a 100% fatality rate. Analysis of the host response to infection during lethal coinfection showed a significant loss of responses associated with lung repair that was not observed in any of the other experimental groups. This group of mice also showed enhanced bacterial replication in the lung. This study reveals that the extent of lung damage during viral infection influences the severity of secondary bacterial infections and may help explain some differences in mortality during influenza pandemics.

scholarly journals Emergence of Polymyxin B Resistance Influences Pathogenicity in Pseudomonas aeruginosa Mutators

2015 ◽  
Vol 59 (7) ◽  
pp. 4343-4346 ◽  
Author(s):  
Zackery P. Bulman ◽  
Mark D. Sutton ◽  
Neang S. Ly ◽  
Jurgen B. Bulitta ◽  
Patricia N. Holden ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Dna Repair ◽  
Real Time ◽  
Median Survival ◽  
Galleria Mellonella ◽  
Polymyxin B ◽  
Survival Times ◽  
Bacterial Reduction ◽  
Content Type ◽  
Emergence Of Resistance

ABSTRACTThe interplay between polymyxin B pharmacodynamics and pathogenicity was examined inPseudomonas aeruginosaPAO1 and isogenic DNA repair-deficient mutators (mutMandmutSstrains). AgainstmutSmutators, polymyxin B initial killing was concentration dependent, with >99.9% bacterial reduction at 2 h followed by regrowth and resistance. The pre- versus postexposed strains were inoculated real time intoGalleria mellonellawaxworms, resulting in increased median survival times from 20 h to 23 h (P< 0.001). Emergence of resistance inmutSP. aeruginosaresulted in attenuation of virulence.

scholarly journals Live Attenuated Mutants of Francisella tularensis Protect Rabbits against Aerosol Challenge with a Virulent Type A Strain

2014 ◽  
Vol 82 (5) ◽  
pp. 2098-2105 ◽  
Author(s):  
Douglas S. Reed ◽  
Le'Kneitah P. Smith ◽  
Kelly Stefano Cole ◽  
Araceli E. Santiago ◽  
Barbara J. Mann ◽  
...  
Keyword(s):  
Weight Loss ◽  
Francisella Tularensis ◽  
Type A ◽  
Content Type ◽  
Time To Death ◽  
Virulent Type ◽  
No Weight Loss ◽  
The 1960S ◽  
Schu S4 ◽  
Derivatives Of

ABSTRACTFrancisella tularensis, a Gram-negative bacterium, is the causative agent of tularemia. No licensed vaccine is currently available for protection against tularemia, although an attenuated strain, dubbed the live vaccine strain (LVS), is given to at-risk laboratory personnel as an investigational new drug (IND). In an effort to develop a vaccine that offers better protection, recombinant attenuated derivatives of a virulent type A strain, SCHU S4, were evaluated in New Zealand White (NZW) rabbits. Rabbits vaccinated via scarification with the three attenuated derivatives (SCHU S4 ΔguaBA, ΔaroD, and ΔfipBstrains) or with LVS developed a mild fever, but no weight loss was detected. Twenty-one days after vaccination, all vaccinated rabbits were seropositive for IgG toF. tularensislipopolysaccharide (LPS). Thirty days after vaccination, all rabbits were challenged with aerosolized SCHU S4 at doses ranging from 50 to 500 50% lethal doses (LD50). All rabbits developed fevers and weight loss after challenge, but the severity was greater for mock-vaccinated rabbits. The ΔguaBAand ΔaroDSCHU S4 derivatives provided partial protection against death (27 to 36%) and a prolonged time to death compared to results for the mock-vaccinated group. In contrast, LVS and the ΔfipBstrain both prolonged the time to death, but there were no survivors from the challenge. This is the first demonstration of vaccine efficacy against aerosol challenge with virulent type AF. tularensisin a species other than a rodent since the original work with LVS in the 1960s. The ΔguaBAand ΔaroDSCHU S4 derivatives warrant further evaluation and consideration as potential vaccines for tularemia and for identification of immunological correlates of protection.

Statistical analysis of clinicopathological features, radiotherapy, and survival in 170 cases of oligodendroglioma

1987 ◽  
Vol 67 (2) ◽  
pp. 224-230 ◽  
Author(s):  
Karl-Fredrik Lindegaard ◽  
Sverre J. Mørk ◽  
Geir E. Eide ◽  
Tore B. Halvorsen ◽  
Reidulv Hatlevoll ◽  
...  
Keyword(s):  
Survival Time ◽  
Median Survival ◽  
Postoperative Radiotherapy ◽  
Survival Rates ◽  
Tumor Resection ◽  
Survival Times ◽  
Term Survival ◽  
Content Type ◽  
Postoperative Irradiation

✓ The postoperative survival time of 170 nonrandomized patients treated for cerebral oligodendrogliomas in Norway from 1953 to 1977 was studied. Survival times were significantly prolonged if postoperative irradiation was performed in addition to surgery (median survival time 26.5 vs. 38 months, p = 0.039). In the group without postoperative radiotherapy, the 5-year rate of survival was 27% compared with 36% in the irradiated patients. The respective survival rates after 8 years were 14% versus 17%; thus, there was little effect on long-term survival. Irradiation appears not to be of benefit after “total” removal. Patients with partly resected lesions appeared to benefit from postoperative radiotherapy; the median survival period after subtotal tumor resection was 37 months with and 26 months without radiotherapy (p = 0.0089). The findings also indicate that irradiation doses between 40 and 50 Gy were as effective as doses between 50 and 60 Gy in increasing the patients' probability of surviving 5 years after subtotal tumor resection. Since the risk of radiation necrosis is proportional to the dose applied, the lower dose is recommended. These conclusions were also valid when adjustments were made for prognostically significant histological and clinical features.

scholarly journals Use of Selective Fungal Culture Media Increases Rates of Detection of Fungi in the Respiratory Tract of Cystic Fibrosis Patients

2017 ◽  
Vol 55 (4) ◽  
pp. 1122-1130 ◽  
Author(s):  
Gina Hong ◽  
Heather B. Miller ◽  
Sarah Allgood ◽  
Richard Lee ◽  
Noah Lechtzin ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Culture Medium ◽  
Bacterial Culture ◽  
Culture Media ◽  
Brain Heart Infusion ◽  
The United States ◽  
Fungal Culture ◽  
Content Type ◽  
Incubation Periods ◽  
A Prospective Study

ABSTRACT The prevalence of fungi in the respiratory tracts of cystic fibrosis (CF) patients has risen. However, fungal surveillance is not routinely performed in most clinical centers in the United States, which may lead to an underestimation of the true prevalence of the problem. We conducted a prospective study comparing the rates of detection for clinically important fungi (CIF), defined as Aspergillus , Scedosporium , and Trichosporon species and Exophiala dermatitidis , in CF sputa using standard bacterial and selective fungal culture media, including Sabouraud dextrose agar with gentamicin (SDA), inhibitory mold agar (IMA), and brain heart infusion (BHI) agar with chloramphenicol and gentamicin. We described the prevalence of these fungi in an adult CF population. A total of 487 CF respiratory samples were collected from 211 unique participants. CIF were detected in 184 (37.8%) samples. Only 26.1% of CIF-positive samples were detected in bacterial culture medium, whereas greater rates of detection for fungi were found in IMA (65.8%; P < 0.001), in SDA (at 30°C, 64.7%; P = 0.005), and in BHI agar (63.0%; P = 0.001). The prevalences of Aspergillus and Scedosporium species were 40.8% and 5.2%, respectively, which are greater than the nationally reported prevalence numbers of 20.4% and 1.9%. Selective fungal culture media and longer incubation periods yielded higher rates of detection for CIF in CF sputum samples compared with that detected in bacterial culture medium, resulting in an underdetection of fungi by bacterial culture alone. The prevalence of fungi in CF may be better estimated by using selective fungal culture media, and this may translate to important clinical decisions.

217. Design and Operation of a Popcorn Butter Flavoring Inhalation Exposure System

2002 ◽  
Author(s):  
T. Goldsmith ◽  
D. Frazer ◽  
W. McKinney ◽  
W. Jones
Keyword(s):  
Inhalation Exposure ◽  
Exposure System
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