scholarly journals Physiological Responses to Multiple Low-Doses of Bacillus anthracis Spores in the Rabbit Model of Inhalation Anthrax

Pathogens ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 877
Author(s):  
Sarah C. Taft ◽  
Tonya L. Nichols ◽  
Stephanie A. Hines ◽  
Roy E. Barnewall ◽  
Gregory V. Stark ◽  
...  

Bacillus anthracis spores that are re-aerosolized from surface deposits after initial contamination present significant health risks for personnel involved in decontamination. To model repeated exposure to low dose B. anthracis spores, three groups of seven rabbits were challenged with multiple low-doses of B. anthracis spores 5 days a week for 3 weeks. Mortality, body temperature, heart and respiration rates, hematology, C-reactive protein, bacteremia, and serum protective antigen were monitored for 21 days post-exposure after the last of multiple doses. All rabbits exposed to a mean daily dose of 2.91 × 102 colony forming units (CFU) survived and showed minimal physiological changes attributable to exposure. One of seven rabbits receiving a mean daily dose of 1.22 × 103 CFU died and four of seven receiving a mean daily dose of 1.17 × 104 CFU died. The LD50 was calculated to be 8.1 × 103 CFU of accumulated dose. Rabbits that succumbed to the higher dose exhibited bacteremia and increases above baseline in heart rate, respiration rate, and body temperature. Two rabbits in the mean daily dose group of 1.17 × 104 CFU exhibited clinical signs of inhalation anthrax yet survived. This study provides a description of lethality, pathophysiology, and pathology in a controlled multiple low-dose inhalation exposure study of B. anthracis in the rabbit model. The data suggest that the accumulated dose is important in survival outcome and that a subset of rabbits may show clinical signs of disease but fully recover without therapeutic intervention

Pathogens ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 461 ◽  
Author(s):  
Sarah C. Taft ◽  
Tonya L. Nichols ◽  
Stephanie A. Hines ◽  
Roy E. Barnewall ◽  
Gregory V. Stark ◽  
...  

Credible dose–response relationships are needed to more accurately assess the risk posed by exposure to low-level Bacillus anthracis contamination during or following a release. To begin to fill this knowledge gap, New Zealand White rabbits were implanted with D70-PCT telemetry transmitters and subsequently aerosol challenged with average inhaled doses of 2.86 × 102 to 2.75 × 105 colony forming units (CFU) of B. anthracis spores. Rabbits exposed to a single inhaled dose at or above 2.54 × 104 CFU succumbed with dose-dependent time to death. Death was associated with increases above baseline in heart rate, respiration rate, and body temperature and all rabbits that died exhibited bacteremia at some point prior to death. Rabbits that inhaled doses of 2.06 × 103 CFU or lower survived to the end of the study and showed no or minimal adverse changes in the measured physiological responses in response to the challenge. Moreover, no bacteremia nor toxemia were observed in rabbits that survived to the end of the study. Overall, the data indicate that challenge doses of B. anthracis below the level sufficient to establish systemic infection do not produce observable physiological responses; however, doses that triggered a response resulted in death.


2007 ◽  
Vol 75 (7) ◽  
pp. 3414-3424 ◽  
Author(s):  
Johnny W. Peterson ◽  
Jason E. Comer ◽  
Wallace B. Baze ◽  
David M. Noffsinger ◽  
Autumn Wenglikowski ◽  
...  

ABSTRACT Dutch-belted and New Zealand White rabbits were passively immunized with AVP-21D9, a human monoclonal antibody to protective antigen (PA), at the time of Bacillus anthracis spore challenge using either nasal instillation or aerosol challenge techniques. AVP-21D9 (10 mg/kg) completely protected both rabbit strains against lethal infection with Bacillus anthracis Ames spores, regardless of the inoculation method. Further, all but one of the passively immunized animals (23/24) were completely resistant to rechallenge with spores by either respiratory challenge method at 5 weeks after primary challenge. Analysis of the sera at 5 weeks after primary challenge showed that residual human anti-PA levels decreased by 85 to 95%, but low titers of rabbit-specific anti-PA titers were also measured. Both sources of anti-PA could have contributed to protection from rechallenge. In a subsequent study, bacteriological and histopathology analyses revealed that B. anthracis disseminated to the bloodstream in some naïve animals as early as 24 h postchallenge and increased in frequency with time. AVP-21D9 significantly reduced the dissemination of the bacteria to the bloodstream and to various organs following infection. Examination of tissue sections from infected control animals, stained with hematoxylin-eosin and the Gram stain, showed edema and/or hemorrhage in the lungs and the presence of bacteria in mediastinal lymph nodes, with necrosis and inflammation. Tissue sections from infected rabbits dosed with AVP-21D9 appeared comparable to corresponding tissues from uninfected animals despite lethal challenge with B. anthracis Ames spores. Concomitant treatment with AVP-21D9 at the time of challenge conferred complete protection in the rabbit inhalation anthrax model. Early treatment increased the efficacy progressively and in a dose-dependent manner. Thus, AVP-21D9 could offer an adjunct or alternative clinical treatment regimen against inhalation anthrax.


Author(s):  
Michaela Dušková ◽  
Martin Hill ◽  
Luboslav Stárka

Abstract: Finasteride is a 5α-reductase inhibitor that has received clinical approval for the treatment of human benign prostatic hyperplasia and androgenetic alopecia. The treatment is practically without side effects, although some occasional cases of depression syndrome have been reported. 5α-Reductase is an enzyme responsible for the reduction of testosterone, progesterone or deoxycorticosterone to their 5α-reduced derivatives possessing anticonvulsant, antidepressant, and anxiolytic activity. Therefore, the formation of GABAergic neuroactive steroids is likely to be impacted by finasteride.: The objective of the study was to show how the treatment of premature androgenetic alopecia with low doses (1 mg/day) of finasteride influences the broad spectrum of steroids with potential neuroactivity.: A group of 12 men with premature androgenetic alopecia participated in the present study. The steroid hormone profile was determined for all individuals. Finasteride was administered for 4 months at a daily dose of 1 mg. After the treatment, the same hormonal profile was determined again.: 5α-Reduced steroids, e.g., 5α-dihydrotestosterone, androsterone, epiandrosterone, 5α-androstene-3α,17β-diol, allopregnanolone, isopregnaolone, and some 5-ene steroids, such as dehydroepiandrosterone and pregnenolone, decreased gradually during treatment.: The decrease of 5α-reduced steroids, especially of allopregnanediol, dihydrotestosterone, and pregnenolone, is probably one of the factors responsible for the increased occurrence of depression in men treated with finasteride, even at low doses.


Author(s):  
Roy E. Barnewall ◽  
Jason E. Comer ◽  
Brian D. Miller ◽  
Bradford W. Gutting ◽  
Daniel N. Wolfe ◽  
...  

2019 ◽  
Vol 4 (4) ◽  
pp. 607-614
Author(s):  
Jean Abitbol

The purpose of this article is to update the management of the treatment of the female voice at perimenopause and menopause. Voice and hormones—these are 2 words that clash, meet, and harmonize. If we are to solve this inquiry, we shall inevitably have to understand the hormones, their impact, and the scars of time. The endocrine effects on laryngeal structures are numerous: The actions of estrogens and progesterone produce modification of glandular secretions. Low dose of androgens are secreted principally by the adrenal cortex, but they are also secreted by the ovaries. Their effect may increase the low pitch and decease the high pitch of the voice at menopause due to important diminution of estrogens and the privation of progesterone. The menopausal voice syndrome presents clinical signs, which we will describe. I consider menopausal patients to fit into 2 broad types: the “Modigliani” types, rather thin and slender with little adipose tissue, and the “Rubens” types, with a rounded figure with more fat cells. Androgen derivatives are transformed to estrogens in fat cells. Hormonal replacement therapy should be carefully considered in the context of premenopausal symptom severity as alternative medicine. Hippocrates: “Your diet is your first medicine.”


1984 ◽  
Vol 52 (03) ◽  
pp. 276-280 ◽  
Author(s):  
Sam Schulman ◽  
Dieter Lockner ◽  
Kurt Bergström ◽  
Margareta Blombäck

SummaryIn order to investigate whether a more intensive initial oral anticoagulation still would be safe and effective, we performed a prospective randomized study in patients with deep vein thrombosis. They received either the conventional regimen of oral anticoagulation (“low-dose”) and heparin or a more intense oral anticoagulation (“high-dose”) with a shorter period of heparin treatment.In the first part of the study 129 patients were randomized. The “low-dose” group reached a stable therapeutic prothrombin complex (PT)-level after 4.3 and the “high-dose” group after 3.3 days. Heparin was discontinued after 6.0 and 5.0 days respectively. There was no difference in significant hemorrhage between the groups, and no clinical signs of progression of the thrombosis.In the second part of the study another 40 patients were randomized, followed with coagulation factor II, VII, IX and X and with repeated venograms. A stable therapeutic PT-level was achieved after 4.4 (“low-dose”) and 3.7 (“high-dose”) days, and heparin was discontinued after 5.4 and 4.4 days respectively. There were no clinical hemorrhages, the activity of the coagulation factors had dropped to the same level in both groups at the time when heparin was discontinued and no thromboembolic complications occurred.Our oral anticoagulation regimen with heparin treatment for an average of 4.4-5 days seems safe and reduces in-patient costs.


2005 ◽  
Author(s):  
Katherine C. Brittingham ◽  
Gordon Ruthel ◽  
Rekha G. Panchal ◽  
Claudette L. Fuller ◽  
Wilson J. Ribot

2020 ◽  
Vol 17 (9) ◽  
pp. 815-822
Author(s):  
Maryam Safary ◽  
Sevil Hakimi ◽  
Noushin Mobaraki-Asl ◽  
Paria Amiri ◽  
Habib Tvassoli ◽  
...  

Introduction: Atrophic vaginitis is a common problem in postmenopausal women and results from decreased levels of blood estrogen. It is associated with symptoms of itching, burning, dyspareunia, and postmenopausal bleeding. The present study evaluated the effects of fenugreek extract on atrophic vaginitis. Materials and Methods: This randomized controlled clinical trial was performed on 60 postmenopausal women in Ardabil, Iran, in 2018. The participants were selected using block randomization with the allocation ratio 1:1. Those in the intervention group received 0.5g (the applicator filled to the half-full mark) fenugreek vaginal cream 5% twice a week for 12 weeks. The control group received conjugated estrogens vaginal cream at the dose of 0.625 mg (the applicator filled to the half-full mark) containing 0.3 mg of conjugated estrogens. Atrophic vaginitis was evaluated before and after the treatment through clinical examination, clinical signs, and measurement of Vaginal Maturation Index (VMI). Findings: After the 12-week intervention and modification of the baseline score, the mean (standard error) score for atrophic vaginitis signs was 3.100 (1.43-4.75). This difference was statistically significant in intragroup comparison and in favor of the control group in intergroup comparison (p=0.001). VMI was less than 49% in 86.7% and 46.7% of the participants in the intervention and control groups, respectively. This was a significant difference in favor of the control group (p=0.001). Conclusion: The results of this study showed that total fenugreek extract could be effective in treating signs of atrophic vaginitis, but it was not as effective as ultra-low-dose estrogen.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Fereidoun Azizi ◽  
Hengameh Abdi ◽  
Atieh Amouzegar

Abstract Background Long-term antithyroid drug therapy has become one of the options for treatment of Graves’ hyperthyroidism. The aim of this study was to compare thyroid status in those who discontinued methimazole (MMI) treatment after 12.8 years with those who continued MMI as long as 24 years. Methods Fifty nine patients with Graves’ disease on long-term MMI for 14.2 ± 2.9 years were recruited; 32 patients (54%) decided to discontinue MMI and 27 (46%) preferred additional years of MMI treatment. All patients were followed for a mean of 6 additional years. Results Of 27 patients who continued MMI up to 24 years, suppressed serum thyrotropin (TSH) was not observed in any patient after the seventh year of treatment. Serum free thyroxine, triiodothyronine, TSH and TSH receptor antibody concentrations remained normal up to the length of the study. Mean daily dose of MMI to maintain TSH in the reference range decreased gradually and reached to 2.8 ± 1.7 mg by 24 years of MMI treatment. No adverse reaction related to MMI occured during additional years of therapy. In 32 patients who discontinued MMI, hyperthyroidism relapsed in 6 patients (19%), one left follow-up and 25 (78%) remained euthyroid during the study. Conclusions Long-term low dose MMI treatment may be a lifelong effective and safe therapeutic modality in patients with Graves’ hyperthyroidism for prevention of relapse, if studies from other centers confirm findings of this research. Trial registration IRCT201009224794N1, 2010-10-25. Retrospectively registered. https://www.irct.ir/trial/5143.


2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 1955.1-1956
Author(s):  
T. Santiago ◽  
M. Voshaar ◽  
M. De Wit ◽  
P. Carvalho ◽  
M. Boers ◽  
...  

Background:The Glucocorticoid Low-dose Outcome in Rheumatoid Arthritis Study (GLORIA) is an international investigator-initiated pragmatic randomized trial designed to study the effects of low-dose glucocorticoids (GCs) in elderly patients with Rheumatoid Arthritis (RA).The research team is also committed to promote a better understanding of the risks and benefits of these drugs among health professionals and patients. In order to achieve these goals, it is important to assess the current ideas and concerns of patients regarding GCs.Objectives:To evaluate the current patient perspective on the efficacy and risks of GCs in RA patients who are or have been treated with GCs.Methods:Patients with RA completed an online survey (with 5 closed questions regarding efficacy and safety) presented in their native language. RA patients were recruited through a variety of patient organizations representing three continents. Patients were invited to participate through national patient organizations. In the USA, patients were also invited to participate through MediGuard.org. Participants were asked for their level of agreement on a 5-point Likert scale.Results:1344 RA patients with exposure to GCs, from Brazil, USA, UK, Portugal, Netherlands, Germany and 24 other countries** participated: 89% female, mean age (SD) 52 (14) years and mean disease duration 13 (11) years. The majority of participants (84%) had ≥10 years of education. The duration of GCs exposure was 1.6 (4.2) years. The majority of participants had read articles or pamphlets on the benefits or harms of GC therapy.Regarding GCs efficacy (table 1), high levels of endorsement were found: about 2/3 of patients considered that GCs as very useful in their case, more than half considered that GCs were effective even at low doses, and agreed that GC improved RA symptoms within days.Regarding safety (table 1), 1/3 of the participants reported having suffered some form of serious adverse events (AEs) due to GCs, and 9% perceived this as “life-threatening. Adverse events had a serious impact on quality of life, according to about 1/3 of the respondents.Conclusion:Patients with RA exposed to GC report a strong conviction that GCs are very useful and effective for the treatment of their RA, even at low doses. This is accompanied by an important prevalence of serious AEs. Understanding the patient perspective can improve shared decision-making between patient and rheumatologist.Funding statement:This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 634886.Disclosure of Interests:Tânia Santiago: None declared, Marieke Voshaar Grant/research support from: part of phd research, Speakers bureau: conducting a workshop (Pfizer), Maarten de Wit Grant/research support from: Dr. de Wit reports personal fees from Ely Lilly, 2019, personal fees from Celgene, 2019, personal fees from Pfizer, 2019, personal fees from Janssen-Cilag, 2017, outside the submitted work., Consultant of: Dr. de Wit reports personal fees from Ely Lilly, 2019, personal fees from Celgene, 2019, personal fees from Pfizer, 2019, personal fees from Janssen-Cilag, 2017, outside the submitted work., Speakers bureau: Dr. de Wit reports personal fees from Ely Lilly, 2019, personal fees from Celgene, 2019, personal fees from Pfizer, 2019, personal fees from Janssen-Cilag, 2017, outside the submitted work., Pedro Carvalho: None declared, Maarten Boers: None declared, Maurizio Cutolo Grant/research support from: Bristol-Myers Squibb, Actelion, Celgene, Consultant of: Bristol-Myers Squibb, Speakers bureau: Sigma-Alpha, Frank Buttgereit Grant/research support from: Amgen, BMS, Celgene, Generic Assays, GSK, Hexal, Horizon, Lilly, medac, Mundipharma, Novartis, Pfizer, Roche, and Sanofi., José Antonio P. da Silva Grant/research support from: Pfizer, Abbvie, Consultant of: Pfizer, AbbVie, Roche, Lilly, Novartis


Sign in / Sign up

Export Citation Format

Share Document