scholarly journals BMS-284756 (T-3811ME) a new fluoroquinolone: in vitro activity against Legionella, efficacy in a guinea pig model of L. pneumophila pneumonia and pharmacokinetics in guinea pigs

2001 ◽  
Vol 48 (5) ◽  
pp. 667-675 ◽  
Author(s):  
P. H. Edelstein
2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Chengcheng Zhu ◽  
Qingzhong Chen ◽  
Ying Yuan ◽  
Min Li ◽  
Bilian Ke

Purpose. This study aimed to investigate the role of endoplasmic reticulum (ER) stress in scleral remodeling in a guinea pig model of form-deprivation myopia (FDM). Methods. Guinea pigs were form deprived to induce myopia. ER ultrastructural changes in the sclera were examined by transmission electron microscopy (TEM). The protein levels of ER stress chaperones, including GRP78, CHOP, and calreticulin (CRT), were analyzed by western blotting at 24 hours, 1 week, and 4 weeks of FD. Scleral fibroblasts from guinea pigs were cultured and exposed to the ER stress inducer tunicamycin (TM) or the ER stress inhibitor 4-phenylbutyric acid (4-PBA). CRT was knocked down by lentivirus-mediated CRT shRNA transfection. The expression levels of GRP78, CHOP, TGF-β1, and COL1A1 were analyzed by qRT-PCR or western blotting. Results. The sclera of FDM eyes exhibited swollen and distended ER at 4 weeks, as well as significantly increased protein expression of GRP78 and CRT at 1 week and 4 weeks, compared to the sclera of the control eyes. In vitro, TM induced ER stress in scleral fibroblasts, which was suppressed by 4-PBA. The mRNA expression of TGF-β1 and COL1A1 was upregulated after TM stimulation for 24 hours, but downregulated for 48 hours. Additionally, change of TGF-β1 and COL1A1 transcription induced by TM was suppressed by CRT knockdown. Conclusions. ER stress was an important modulator which could influence the expression of the scleral collagen. CRT might be a new target for the intervention of the FDM scleral remodeling process.


2009 ◽  
Vol 58 (5) ◽  
pp. 648-655 ◽  
Author(s):  
Kristel Lourdault ◽  
Florence Aviat ◽  
Mathieu Picardeau

The dynamics of leptospirosis infection have been poorly studied. The purpose of this study was to determine the LD50, rate of bacterial dissemination, histopathology and antibody responses against leptospira following inoculation with the highly virulent Leptospira interrogans Fiocruz L1-130 strain in a guinea pig model of leptospirosis. Three routes of infection (intraperitoneal, conjunctival and subcutaneous inoculation) were used to establish disease in guinea pigs. The size and kinetics of leptospiral burdens in the blood and tissues of infected animals were determined over a 1 week course of infection using quantitative real-time PCR (qPCR). Bacteraemia peaked at day 5 post-infection reaching more than 5×104 leptospires ml−1. The highest spirochaetal load was found in the liver and kidneys, and was associated with alterations in organ tissues and a decline in liver and kidney functions. In contrast, lesions and bacteria were not detected in guinea pigs infected with an avirulent strain derived from a high-passage-number in vitro-passaged variant of the Fiocruz L1-130 strain. The use of qPCR supports the findings of earlier studies and provides an easy and reliable method for the quantification of L. interrogans in the tissues of infected animals. qPCR will be used in future studies to evaluate the efficacy of vaccine candidates against leptospirosis and the virulence of selected L. interrogans mutants relative to the parental strain.


2004 ◽  
Vol 72 (1) ◽  
pp. 489-497 ◽  
Author(s):  
Anna I. Bakardjiev ◽  
Brian A. Stacy ◽  
Susan J. Fisher ◽  
Daniel A. Portnoy

ABSTRACT Feto-placental infections represent a major cause of pregnancy complications, and yet the underlying molecular and cellular mechanisms of vertical transmission are poorly understood. Listeria monocytogenes, a facultative intracellular pathogen, is one of a group of pathogens that are known to cause feto-placental infections in humans and other mammals. The purpose of this study was to evaluate possible mechanisms of vertical transmission of L. monocytogenes. Humans and guinea pigs have a hemochorial placenta, where a single layer of fetally derived trophoblasts separates maternal from fetal circulation. We characterized L. monocytogenes infection of the feto-placental unit in a pregnant guinea pig model and in primary human trophoblasts and trophoblast-derived cell lines. The clinical manifestations of listeriosis in the pregnant guinea pigs and the tropism of L. monocytogenes to the guinea pig placenta resembled those in humans. Trophoblast cell culture systems were permissive for listerial growth and cell-to-cell spread and revealed that L. monocytogenes deficient in internalin A, a virulence factor that mediates invasion of nonphagocytic cells, was 100-fold defective in invasion. However, crossing of the feto-placental barrier in the guinea pig model was independent of internalin A, suggesting a negligible role for internalin-mediated direct invasion of trophoblasts in vivo. Further understanding of vertical transmission of L. monocytogenes will help in designing more effective means of treatment and disease prevention.


Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 3724-3724
Author(s):  
Lana Kaiser ◽  
John Davis ◽  
Jon Patterson ◽  
N. Bari Olivier ◽  
George Bohart ◽  
...  

Abstract Cardiac events, including heart failure and arrhythmias, are the major cause of death in patients with b-thalassemia. Although cardiac arrhythmias in humans are believed to result from iron overload, excluding confounding factors in the human population is difficult. The purpose of these studies was to evaluate the development of cardiac arrhythmias using the guinea pig model of secondary iron overload. Electrocardiograms were recorded via surgically implanted telemetry devices in guinea pigs loaded intraperitoneally with iron dextran and controls. Cardiac and liver iron concentrations were significantly elevated in the iron loaded animals when compared to control, and were in the range of those reported for humans with thalassemia. Arrhythmias were noted infrequently in both iron loaded and control guinea pigs. No life threatening arrhythmias were detected in either group. These data suggest that iron alone may be insufficient to cause cardiac arrhythmias, and that arrhythmias detected in individuals with iron overload may be the result of a complex interplay of factors.


2020 ◽  
Author(s):  
Antonin C André ◽  
Céline Mulet ◽  
Mark C Anderson ◽  
Louise Injarabian ◽  
Achim Buch ◽  
...  

AbstractShigella spp. are the causative agents of bacillary dysentery or shigellosis, mainly in children living in developing countries. The study of Shigella entire life cycle in vivo and the evaluation of vaccine candidates’ protection efficacy have been hampered by the lack of a suitable animal model of infection (1). None of the ones evaluated so far (mouse, rabbit, guinea pig) allows to recapitulate shigellosis symptoms upon Shigella oral challenge. Historical reports suggest that dysentery and scurvy are both metabolic diseases associated with ascorbate-deficiency. Mammals which are susceptible to Shigella infection (humans, non-human primates and guinea pigs) are the lonely ones which are unable to synthesize ascorbate. We optimized a low-ascorbate diet to induce moderate ascorbate-deficiency but not scurvy in guinea pigs (Ascplasma conc.=1.6 μM vs 36 μM with optimal ascorbate supply). We demonstrated that moderate ascorbate-deficiency increases shigellosis severity during extended period of time (up to 48h) with all strains tested (Shigella flexneri 5a and 2a, Shigella sonnei). At late time-points, a massive influx of neutrophils was observed both within the disrupted colonic mucosa and in the luminal compartment, although Shigella remains able to disseminate deep into the organ to reach the sub-mucosal layer and the bloodstream. This new model of shigellosis opens new doors for the study both of Shigella infection strategy and innate and adaptive immune responses to Shigella infection. It may be also of a great interest to study the virulence of other pathogen for which no suitable animal model of infection is available (Vibrio cholerae, Yersinia pestis, Mycobacterium tuberculosis or Campylobacter jejuni, among others).SignificanceThe study of Shigella virulence cycle in vivo has been hampered by the lack of a suitable animal model, which would allow the colonic mucosa infection upon oral challenge. Based on historical reports and physiological aspects, it was suggested that ascorbate-deficiency may stand as a new dysentery risk-factor. To test this hypothesis, we set up a new ascorbate-deficient guinea pig model and demonstrated for the first time that the Shigella infectious process occurred for extended period of time (up to 48h) and demonstrated that shigellosis severity was higher in ascorbate-deficient animal. Ascorbate-deficient guinea pig model of infection may be used to assess the virulence of other pathogens for which no suitable animal model of infection is still lacking.


2020 ◽  
Author(s):  
Mariska van den Berg ◽  
Susan Nijboer - Brinksma ◽  
Sophie Bos ◽  
Maarten van den Berge ◽  
David Lamb ◽  
...  

Abstract Background: We hypothesized that TRPA1 channels contribute to airway hyperresponsiveness (AHR) and inflammation in asthma. We evaluated the efficacy of the novel TRPA1 antagonist BI01305834 in a guinea pig model of asthma. Methods: First a pilot study was performed in a guinea pig model of allergic asthma to find the optimal dose of BI01305834. Next, the effect of BI01305834 on AHR to inhaled histamine after the early and late asthmatic reaction (EAR and LAR), magnitude of EAR and LAR and airway inflammation was assessed. Precision-cut lung slices and trachea strips were used to investigate the bronchoprotective and bronchodilating effect of BI01305834. Statistical evaluation of differences of in vivo data was performed using a Mann-Whitney U test or One-way nonparametric Kruskal-Wallis ANOVA, for ex vivo data One- or Two-way ANOVA was used, all with Dunnett’s post-hoc test where appropriate.Results: A dose of 1 mg/kg BI01305834 was selected based on AHR and exposure data in blood samples from the pilot study. In the subsequent study 1 mg/kg BI01305834 inhibited AHR after the EAR, and the development of EAR and LAR elicited by ovalbumin in ovalbumin-sensitized guinea pigs. BI01305834 did not inhibit allergen-induced total and differential cells in the lavage fluid and interleukin-13 gene expression in lung homogenates. Furthermore, BI01305834 was able to inhibit allergen and histamine-induced airway narrowing in guinea pig lung slices, without affecting histamine release, and reverse allergen-induced bronchoconstriction in guinea pig trachea strips.Conclusions: TRPA1 inhibition protects against AHR and the EAR and LAR in vivo and allergen and histamine-induced airway narrowing ex vivo, and reverses allergen-induced bronchoconstriction, independently of inflammation. This effect was partially dependent upon histamine, suggesting a neuronal and possible non-neuronal role for TRPA1 in allergen-induced bronchoconstriction.


2020 ◽  
Author(s):  
Dina Bugybayeva ◽  
Zhailaubay Kydyrbayev ◽  
Nadezhda Zinina ◽  
Nurika Assanzhanova ◽  
Bolat Yespembetov ◽  
...  

Abstract Background: A new candidate vector vaccine against human brucellosis based on recombinant influenza viral vectors (rIVV) subtypes H5N1 expressing Brucella Omp16, L7/L12, Omp19 or Cu-Zn SOD proteins has been developed. This paper presents the results of the study of protection of the vaccine with various options of administering, dosing and frequency of use on guinea pigs.Methods: General states of guinea pigs was assessed based on , behavior and dynamics of a guinea pig weight-gain test. The effectiveness of the new anti-brucellosis vector vaccine was determined by studying its protective effect after conjunctival, intranasal and sublingual administration in doses 105 EID50, 106 EID50 and 107 EID50 during prime and boost vaccinations of animals, followed by challenge with a virulent strain of B. mellitensis 16M infection. For sake of comparison, the commercial B. melitensis Rev.1 vaccine was used as a control. The protective properties of vaccines were assessed by quantitation of Brucella colonization in organs and tissues of infected animals and compared to the control groups.Results: It was observed a gradual increase in body weight of guinea pigs after prime and booster immunization with the vaccine using conjunctival, intranasal and sublingual routes of administration, as well as after using various doses of vaccine. . The most optimal way of using the vaccine has been established: double intranasal immunization of guinea pigs at a dose of 106 EID50, which provides 80% protection of guinea pigs from B. melitensis 16M infection (P < 0.05), which is comparable to the results of the effectiveness of the commercial B. melitensis Rev.1 vaccine.Conclusions: We developed effective vaccine candidate against brucellosis and developed its immunization protocol in guinea pig model. We believe that this study is a substantial step for using the vaccine for future pre-clinical and clinical trials in human.


2020 ◽  
Author(s):  
Dina Bugybayeva ◽  
Zhailaubay Kydyrbayev ◽  
Nadezhda Zinina ◽  
Nurika Assanzhanova ◽  
Bolat Yespembetov ◽  
...  

Abstract Background: A new candidate vector vaccine against human brucellosis based on recombinant influenza viral vectors (rIVV) subtypes H5N1 expressing Brucella Omp16, L7/L12, Omp19 or Cu-Zn SOD proteins has been developed. This paper presents the results of the study of the safety and protective properties of the vaccine with various options of administering, dosing and frequency of use on guinea pigs.Methods: The safety of the vaccine was assessed based on the general condition, behavior and dynamics of a guinea pig weight-gain test. The effectiveness of the new anti-brucellosis vector vaccine was determined by studying its protective effect after conjunctival, intranasal and sublingual administration in doses 105 EID50, 106 EID50 and 107 EID50 during prime and boost vaccinations of animals, followed by challenge with a virulent strain of B. mellitensis 16M infection. For sake of comparison, the commercial B. melitensis Rev.1 vaccine was used as a control. The protective properties of vaccines were assessed by quantitation of Brucella colonization in organs and tissues of infected animals and compared to the control groups.Results: It was found that the vaccine after prime and booster immunization using conjunctival, intranasal and sublingual routes of administration, as well as after using various doses of vaccine were safe for guinea pigs. The most optimal way of using the vaccine has been established: double intranasal immunization of guinea pigs at a dose of 106 EID50, which provides 80% protection of guinea pigs from B. melitensis 16M infection (P < 0.05), which is comparable to the results of the effectiveness of the commercial B. melitensis Rev.1 vaccine.Conclusions: We developed effective vaccine candidate against brucellosis and developed its immunization protocol in guinea pig model. We believe that this study is a substantial step for using the vaccine for future pre-clinical and clinical trials in human.


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