RESUMEN
Nerve agent exposure is generally treated by an antidote formulation composed of a muscarinic antagonist, atropine sulfate (ATR), and a reactivator of acetylcholinesterase (AChE) such as pralidoxime, obidoxime (OBI), methoxime, trimedoxime or HI-6 and an anticonvulsant. Organophosphates (OPs) irreversibly inhibit AChE, the enzyme responsible for termination of acetylcholine signal transduction. Inhibition of AChE leads to overstimulation of the central and peripheral nervous system with convulsive seizures, respiratory distress and death as result. The present study evaluated the efficacy and pharmacokinetics (PK) of ATR/OBI following exposure to two different VX dose levels. The PK of ATR and OBI administered either as a single drug, combined treatment but separately injected, or administered as the ATR/OBI co-formulation, was determined in plasma of naïve guinea pigs and found to be similar for all formulations. Following subcutaneous VX exposure, ATR/OBI-treated animals showed significant improvement in survival rate and progression of clinical signs compared to untreated animals. Moreover, AChE activity after VX exposure in both blood and brain tissue was significantly higher in ATR/OBI-treated animals compared to vehicle-treated control. In conclusion, ATR/OBI has been proven to be efficacious against exposure to VX and there were no PK interactions between ATR and OBI when administered as a co-formulation.
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Atropina , Sustancias para la Guerra Química/toxicidad , Inhibidores de la Colinesterasa/toxicidad , Reactivadores de la Colinesterasa , Antagonistas Muscarínicos , Cloruro de Obidoxima , Compuestos Organotiofosforados/toxicidad , Acetilcolinesterasa/sangre , Acetilcolinesterasa/metabolismo , Animales , Atropina/sangre , Atropina/farmacocinética , Atropina/uso terapéutico , Encéfalo/metabolismo , Reactivadores de la Colinesterasa/sangre , Reactivadores de la Colinesterasa/farmacocinética , Reactivadores de la Colinesterasa/uso terapéutico , Modelos Animales de Enfermedad , Combinación de Medicamentos , Cobayas , Masculino , Antagonistas Muscarínicos/sangre , Antagonistas Muscarínicos/farmacocinética , Antagonistas Muscarínicos/uso terapéutico , Cloruro de Obidoxima/sangre , Cloruro de Obidoxima/farmacocinética , Cloruro de Obidoxima/uso terapéutico , Resultado del TratamientoRESUMEN
This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editors-in-Chief as the authors were unable to provide documentation of approval for the interinstitutional assurance /vertebrate animal section of the paper by the relevant authority, Public Health Service (PHS) Office of Laboratory Animal Welfare (OLAW) in the time that was provided.
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This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editors-in-Chief as the authors were unable to provide documentation of approval for the interinstitutional assurance/vertebrate animal section of the paper by the relevant authority, Public Health Service (PHS) Office of Laboratory Animal Welfare (OLAW) in the time that was provided.
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AV7909 is a next-generation anthrax vaccine under development for post-exposure prophylaxis following suspected or confirmed Bacillus anthracis exposure, when administered in conjunction with the recommended antibacterial regimen. AV7909 consists of the FDA-approved BioThrax® vaccine (anthrax vaccine adsorbed) and an immunostimulatory Toll-like receptor 9 agonist oligodeoxynucleotide adjuvant, CPG 7909. The purpose of this study was to evaluate the potential systemic and local toxicity of AV7909 when administered via repeat intramuscular injection to the right thigh muscle (biceps femoris) to male and female Sprague Dawley rats. The vaccine was administered on Days 1, 15, and 29 and the animals were assessed for treatment-related effects followed by a 2-week recovery period to evaluate the persistence or reversibility of any toxic effects. The AV7909 vaccine produced no apparent systemic toxicity based on evaluation of clinical observations, body weights, body temperature, clinical pathology, and anatomic pathology. Necrosis and inflammation were observed at the injection sites as well as in regional lymph nodes and adjacent tissues and were consistent with immune stimulation. Antibodies against B. anthracis protective antigen (PA) were detected in rats treated with the AV7909 vaccine, confirming relevance of this animal model for the assessment of systemic toxicity of AV7909. In contrast, sera of rats that received saline or soluble CPG 7909 alone were negative for anti-PA antibodies. Overall, 3 intramuscular immunizations of Sprague Dawley rats with AV7909 were well tolerated, did not induce mortality or any systemic adverse effects, and did not result in any delayed toxicity.
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Adyuvantes Inmunológicos/administración & dosificación , Vacunas contra el Carbunco/administración & dosificación , Oligodesoxirribonucleótidos/administración & dosificación , Adyuvantes Inmunológicos/toxicidad , Animales , Vacunas contra el Carbunco/toxicidad , Anticuerpos Antibacterianos/sangre , Anticuerpos Neutralizantes/sangre , Antígenos Bacterianos/inmunología , Toxinas Bacterianas/inmunología , Femenino , Reacción en el Punto de Inyección/sangre , Reacción en el Punto de Inyección/etiología , Reacción en el Punto de Inyección/inmunología , Reacción en el Punto de Inyección/patología , Inyecciones Intramusculares , Masculino , Músculo Esquelético/efectos de los fármacos , Músculo Esquelético/patología , Oligodesoxirribonucleótidos/toxicidad , Profilaxis Posexposición , Ratas Sprague-DawleyRESUMEN
AV7909 is a next-generation anthrax vaccine candidate indicated for post-exposure prophylaxis of exposure to Bacillus anthracis. AV7909 consists of the Anthrax Vaccine Adsorbed (AVA) bulk drug substance and the immunostimulatory Toll-like receptor 9 agonist oligodeoxynucleotide adjuvant, CPG 7909. Safety testing for pediatric population is warranted to support the potential emergency use of AV7909 in children. This study was conducted to investigate the local tolerance and potential systemic toxicity and their reversibility in juvenile rats by repeat intramuscular injections of the AV7909 vaccine candidate. Animals were dosed on postnatal day (PND) 21 (at weaning), PND 28, and PND 35, with the test article (AV7909), the adjuvant alone (Alhydrogel + CPG 7909), or sterile water for injection. Core group animals were necropsied on PND 37 and recovery group on PND 49. Study end points included survival, clinical observations, injection site observations, body weights, clinical pathology (hematology, coagulation, and clinical chemistry), pro-inflammatory biomarker analysis (alpha-2 macroglobulin [A2M] and alpha-1 acid glycoprotein [AGP]), and anatomic pathology. Immune response to vaccination was measured using the high-throughput anthrax lethal toxin neutralization assay (htpTNA). The AV7909 vaccine candidate produced no apparent systemic or local toxicity. The AGP and A2M levels were elevated in both the adjuvant-alone and AV7909 groups at the end of treatment but were comparable to control levels by the end of the recovery period. All animals in the AV7909 group demonstrated a robust neutralizing antibody response. The results indicate that AV7909 has a favorable safety profile in juvenile rats.
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A recombinant protective antigen (rPA) anthrax vaccine candidate (rPA7909) was developed as a next-generation vaccine indicated for postexposure prophylaxis of disease resulting from suspected or confirmed Bacillus anthracis exposure. The lyophilized form of rPA7909-vaccinated candidate contains 75 µg purified rPA, 750 µg aluminum (as Alhydrogel adjuvant), and 250 µg of an immunostimulatory Toll-like receptor 9 agonist oligodeoxynucleotide CpG 7909 in a 0.5 mL phosphate-buffered suspension. General toxicity and local reactogenicity were evaluated in Sprague Dawley rats vaccinated with the full human dose of rPA7909 by intramuscular injection. Animals were immunized on study days 1, 15, and 29. Control groups were administered diluent only or adjuvant control (excipients, CpG 7909, and Alhydrogel adjuvant in diluent) intramuscularly at the same dose volume and according to the same schedule used for rPA7909. Toxicity was assessed based on the results of clinical observations, physical examinations, body weights, injection site reactogenicity, ophthalmology, clinical pathology (hematology, coagulation, and serum chemistry), organ weights, and macroscopic and microscopic pathology evaluation. The immune response to rPA7909 vaccination was confirmed by measuring serum anti-PA immunoglobulin G levels. The rPA7909 vaccine produced no apparent systemic toxicity and only transient reactogenicity at the injection site. The injection site reaction from animals receiving the adjuvant control was very similar to those receiving rPA7909 with respect to the inflammation. The inflammatory response observed in the injection site and the draining lymph nodes was consistent with expected immune stimulation. The overall results indicated a favorable safety profile for rPA7909.
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Adyuvantes Inmunológicos/toxicidad , Vacunas contra el Carbunco/toxicidad , Antígenos Bacterianos/toxicidad , Toxinas Bacterianas/toxicidad , Oligodesoxirribonucleótidos/toxicidad , Animales , Antígenos Bacterianos/inmunología , Toxinas Bacterianas/inmunología , Femenino , Liofilización , Inmunoglobulina G/sangre , Masculino , Ratas Sprague-Dawley , Proteínas Recombinantes/toxicidadRESUMEN
In recent years, various poisoning incidents have been reported, involving the alleged use of the so-called Novichok agents, resulting in their addition to the Schedule I list of the Organisation for the Prohibition of Chemical Warfare (OPCW). As the physicochemical properties of these agents are different from the 'classical' nerve agents, such as VX, research is needed to evaluate whether and to what extent existing countermeasures are effective. Here, we evaluated the therapeutic potential of RSDL® (Reactive Skin Decontamination Lotion Kit) for the neutralization of percutaneous toxicity caused by Novichok agents, both in vitro and in vivo. Experiments showed the three selected Novichok agents (A230, A232, A234) could be degraded by RSDL lotion, but at a different rate. The half-life of A234, in the presence of an excess of RSDL lotion, was 36 min, as compared to A230 (<5 min) and A232 (18 min). Following dermal exposure of guinea pigs to A234, application of the RSDL kit was highly effective in preventing intoxication, even when applied up until 30 min following exposure. Delayed use of the RSDL kit until the appearance of clinical signs of intoxication (3-4 h) was not able to prevent intoxication progression and deaths. This study determines RSDL decontamination as an effective treatment strategy for dermal exposure to the Novichok agent A234 and underscores the importance of early, forward use of skin decontamination, as rapidly as possible.
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Descontaminación , Agentes Nerviosos , Piel , Animales , Cobayas , Descontaminación/métodos , Piel/efectos de los fármacos , Agentes Nerviosos/toxicidad , Agentes Nerviosos/química , Crema para la Piel/farmacología , Crema para la Piel/química , Masculino , Sustancias para la Guerra Química/toxicidadRESUMEN
Nonhuman primates (NHPs) and rabbits are the animal models most commonly used to evaluate the efficacy of medical countermeasures against anthrax in support of licensure under the FDA's "Animal Rule." However, a need for an alternative animal model may arise in certain cases. The development of such an alternative model requires a thorough understanding of the course and manifestation of experimental anthrax disease induced under controlled conditions in the proposed animal species. The guinea pig, which has been used extensively for anthrax pathogenesis studies and anthrax vaccine potency testing, is a good candidate for such an alternative model. This study was aimed at determining the median lethal dose (LD50) of the Bacillus anthracis Ames strain in guinea pigs and investigating the natural history, pathophysiology, and pathology of inhalational anthrax in this animal model following nose-only aerosol exposure. The inhaled LD50 of aerosolized Ames strain spores in guinea pigs was determined to be 5.0 × 10(4) spores. Aerosol challenge of guinea pigs resulted in inhalational anthrax with death occurring between 46 and 71 h postchallenge. The first clinical signs appeared as early as 36 h postchallenge. Cardiovascular function declined starting at 20 h postexposure. Hematogenous dissemination of bacteria was observed microscopically in multiple organs and tissues as early as 24 h postchallenge. Other histopathologic findings typical of disseminated anthrax included suppurative (heterophilic) inflammation, edema, fibrin, necrosis, and/or hemorrhage in the spleen, lungs, and regional lymph nodes and lymphocyte depletion and/or lymphocytolysis in the spleen and lymph nodes. This study demonstrated that the course of inhalational anthrax disease and the resulting pathology in guinea pigs are similar to those seen in rabbits and NHPs, as well as in humans.
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Carbunco/patología , Carbunco/fisiopatología , Bacillus anthracis/patogenicidad , Modelos Animales de Enfermedad , Animales , Carbunco/mortalidad , Femenino , Cobayas , Dosificación Letal Mediana , Masculino , Análisis de Supervivencia , Factores de TiempoRESUMEN
Chronic intermittent hypoxia (IH) during sleep can result from obstructive sleep apnea (OSA), a disorder that is particularly prevalent in obesity. OSA is associated with high levels of circulating leptin, cardiovascular dysfunction, and dyslipidemia. Relationships between leptin and cardiovascular function in OSA and chronic IH are poorly understood. We exposed lean wild-type (WT) and obese leptin-deficient ob/ob mice to IH for 4 wk, with and without leptin infusion, and measured cardiovascular indices including aortic vascular stiffness, endothelial function, cardiac myocyte morphology, and contractile properties. At baseline, ob/ob mice had decreased vascular compliance and endothelial function vs. WT mice. We found that 4 wk of IH decreased vascular compliance and endothelial relaxation responses to acetylcholine in both WT and leptin-deficient ob/ob animals. Recombinant leptin infusion in both strains restored IH-induced vascular abnormalities toward normoxic WT levels. Cardiac myocyte morphology and function were unaltered by IH. Serum cholesterol and triglyceride levels were significantly decreased by leptin treatment in IH mice, as was hepatic stearoyl-Coenzyme A desaturase 1 expression. Taken together, these data suggest that restoring normal leptin signaling can reduce vascular stiffness, increase endothelial relaxation, and correct dyslipidemia associated with IH.
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Hiperlipidemias/tratamiento farmacológico , Hipoxia/tratamiento farmacológico , Leptina/fisiología , Transducción de Señal/fisiología , Resistencia Vascular/efectos de los fármacos , Acetilcolina/farmacología , Animales , Enfermedad Crónica , Leptina/administración & dosificación , Leptina/genética , Lípidos/sangre , Hígado/efectos de los fármacos , Hígado/enzimología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Obesos , Miocitos Cardíacos/citología , Miocitos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/fisiología , Transducción de Señal/efectos de los fármacos , Estearoil-CoA Desaturasa/biosíntesisRESUMEN
The AV7909 vaccine, consists of the Anthrax Vaccine Adsorbed (AVA) bulk drug substance and the immunostimulatory Toll-like receptor 9 agonist oligodeoxynucleotide adjuvant CPG 7909. The purpose of this research was to evaluate the potential maternal, reproductive, and developmental toxicity of AV7909 in rats to support licensure for use in women of childbearing potential. Groups of first generation (F0 ) female Sprague Dawley rats were dosed by intramuscular injection with water for injection, adjuvant or AV7909 at a volume of 0.5 ml/dose. Each rat received three vaccinations: 14 days prior to start of the mating period, on the first day of the mating period and on gestation day (GD) 7. There was no maternal mortality. Body weights, weight gain, and food consumption were comparable between groups. Findings in F0 females were limited to transient injection site edema and nodules consistent with immunostimulatory effects of the vaccine and adjuvant. Administration of AV7909 did not affect mating, fertility, pregnancy, embryo-fetal viability, growth, or morphologic development, parturition, maternal care of offspring or postnatal survival, growth, or development. There was no evidence of systemic inflammation in pregnant rats, based on evaluation of serum concentrations of the acute phase proteins alpha-2-macroglobulin and alpha-1-acid glycoprotein on GD 21. Anthrax lethal toxin-neutralizing antibodies were detected in AV7909-vaccinated F0 females. The antibodies were also detected in the sera of fetuses and F1 pups. Exposure of the fetuses and pups to maternally derived anthrax lethal toxin-neutralizing antibodies was not associated with developmental toxicity.
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Vacunas contra el Carbunco , Carbunco , Animales , Carbunco/prevención & control , Anticuerpos Neutralizantes , Femenino , Embarazo , Ratas , Ratas Sprague-Dawley , ReproducciónRESUMEN
The anthrax vaccine candidate AV7909 is being developed as a next-generation vaccine for post-exposure prophylaxis (PEP) against inhalational anthrax. In clinical studies, two vaccinations with AV7909 administered either two or four weeks apart induced an enhanced immune response compared to BioThrax® (Anthrax Vaccine Adsorbed) (AVA). Anthrax toxin-neutralizing antibody (TNA) levels on Day 70 following initial vaccination that were associated with protection of animals exposed to inhalational anthrax were previously reported for the 0, 4-week AV7909 vaccination regimen. The current study shows that a 0, 2-week AV7909 vaccination regimen protected guinea pigs (GPs) and nonhuman primates (NHPs) against a lethal inhalational anthrax challenge on Days 28 and 70 after the first immunization. An earlier induction of protective TNA levels using a 0, 2-week AV7909 vaccination regimen may provide benefit over the currently approved AVA PEP 0, 2, and 4-week vaccination regimen.
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Vacunas contra el Carbunco , Carbunco , Bacillus anthracis , Animales , Carbunco/prevención & control , Anticuerpos Antibacterianos , Anticuerpos Neutralizantes , Antígenos Bacterianos , Cobayas , Profilaxis Posexposición , PrimatesRESUMEN
Obstructive sleep apnea may cause vascular inflammation and atherosclerosis, which has been attributed to intermittent hypoxia (IH). Recent data suggest that IH, but not sustained hypoxia (SH), activates proinflammatory genes in HeLa cells. Effects of IH and SH on the gene expression profile in human aortic endothelial cells (HAEC) have not been compared. We perfused media with alternating flow of 16% and 0% O2 (IH) or constant flow of 4% O2 (SH-4%), 8% O2 (SH-8%), or 16% O2 (control) for 8 h. Illumina gene microarrays were performed, with subsequent verification by real-time PCR. Proinflammatory cytokines in the media were measured by ELISA. Both IH and SH-4% upregulated proinflammatory genes, including heat shock protein 90-kDa B1, tumor necrosis factor superfamily member 4, and thrombospondin 1. Among all proinflammatory genes, only IL-8 mRNA showed significantly higher levels of expression (1.78-fold) during IH, compared with SH-4%, but both types of hypoxic exposure elicited striking three- to eightfold increases in IL-8 and IL-6 protein levels in the media. IH and SH-4% also upregulated antioxidant genes, including heme oxygenase-1 and nuclear factor (erythroid-derived 2)-like 2 (NRF2), whereas classical genes regulated by hypoxia-inducible factor 1 (HIF-1), such as endothelin and glucose transporter GLUT1, were not induced. SH-8% induced changes in gene expression and cytokine secretion that were similar to those of IH and SH-4%. In conclusion, short exposures to IH and SH upregulate proinflammatory and antioxidant genes in HAEC and increase secretion of proinflammatory cytokines IL-8 and IL-6 into media in similar fashions.
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Aorta/patología , Células Endoteliales/metabolismo , Células Endoteliales/patología , Perfilación de la Expresión Génica , Hipoxia/genética , Transporte de Electrón/genética , Regulación de la Expresión Génica , Células HeLa , Humanos , Mediadores de Inflamación/metabolismo , Mitocondrias/metabolismo , Estrés Oxidativo/genética , Oxígeno/metabolismo , Temperatura , Transcriptoma/genéticaRESUMEN
Obstructive sleep apnea leads to chronic intermittent hypoxia (CIH) and is associated with atherosclerosis. We have previously shown that C57BL/6J mice exposed to CIH and a high-cholesterol diet develop dyslipidemia, atherosclerosis of the aorta, and upregulation of a hepatic enzyme of lipoprotein secretion, stearoyl coenzyme A desaturase 1 (SCD-1). We hypothesized that (1) SCD-1 deficiency will prevent dyslipidemia and atherosclerosis during CIH; and (2) human OSA is associated with dyslipidemia and upregulation of hepatic SCD. C57BL/6J mice were exposed to CIH or normoxia for 10 weeks while being treated with either SCD-1 or control antisense oligonucleotides. Obese human subjects underwent sleep study and bariatric surgery with intraoperative liver biopsy. In mice, hypoxia increased hepatic SCD-1 and plasma very-low-density lipoprotein cholesterol levels and induced atherosclerosis lesions in the ascending aorta (the cross-section area of 156514+/-57408 microm(2)), and descending aorta (7.0+/-1.2% of the total aortic surface). In mice exposed to CIH and treated with SCD-1 antisense oligonucleotides, dyslipidemia and atherosclerosis in the ascending aorta were abolished, whereas lesions in the descending aorta showed 56% reduction. None of the mice exposed to normoxia developed atherosclerosis. In human subjects, hepatic SCD mRNA levels correlated with the degree of nocturnal hypoxemia (r=0.68, P=0.001). Patients exhibiting oxyhemoglobin desaturations at night showed higher plasma triglyceride and low-density lipoprotein cholesterol levels, compared to subjects without hypoxemia. In conclusion, CIH is associated with dyslipidemia and overexpression of hepatic SCD in both humans and mice alike; SCD-1 deficiency attenuates CIH-induced dyslipidemia and atherosclerosis in mice.
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Aterosclerosis/enzimología , Dieta Aterogénica , Dislipidemias/enzimología , Hipoxia/enzimología , Hígado/enzimología , Síndrome de Hipoventilación por Obesidad/enzimología , Oligonucleótidos Antisentido/farmacología , Estearoil-CoA Desaturasa/antagonistas & inhibidores , Estearoil-CoA Desaturasa/biosíntesis , Animales , Aorta/enzimología , Aorta/patología , Aterosclerosis/inducido químicamente , Aterosclerosis/patología , Colesterol/efectos adversos , Colesterol/farmacología , VLDL-Colesterol/sangre , Enfermedad Crónica , Dislipidemias/inducido químicamente , Dislipidemias/patología , Inducción Enzimática/efectos de los fármacos , Humanos , Hipoxia/inducido químicamente , Hipoxia/patología , Hígado/patología , Masculino , Ratones , Síndrome de Hipoventilación por Obesidad/patología , Oxihemoglobinas/metabolismo , ARN Mensajero/antagonistas & inhibidores , ARN Mensajero/metabolismo , Triglicéridos/sangre , Regulación hacia Arriba/efectos de los fármacosRESUMEN
RATIONALE: Obstructive sleep apnea is associated with insulin resistance and liver injury. It is unknown whether apnea contributes to insulin resistance and steatohepatitis in severe obesity. OBJECTIVES: To examine whether sleep apnea and nocturnal hypoxemia predict the severity of insulin resistance, systemic inflammation, and steatohepatitis in severely obese individuals presenting for bariatric surgery. METHODS: We performed sleep studies and measured fasting blood glucose, serum insulin, C-reactive protein, and liver enzymes in 90 consecutive severely obese individuals, 75 women and 15 men, without concomitant diabetes mellitus or preexistent diagnosis of sleep apnea or liver disease. Liver biopsies (n = 20) were obtained during bariatric surgery. MEASUREMENTS AND MAIN RESULTS: Obstructive sleep apnea with a respiratory disturbance index greater than 5 events/hour was diagnosed in 81.1% of patients. The median respiratory disturbance index was 15 +/- 29 events/hour and the median oxygen desaturation during apneic events was 4.6 +/- 1.8%. All patients exhibited high serum levels of C-reactive protein, regardless of the severity of apnea, whereas liver enzymes were normal. Oxygen desaturation greater than 4.6% was associated with a 1.5-fold increase in insulin resistance, according to the homeostasis model assessment index. Histopathology data suggested that significant nocturnal desaturation might predispose to hepatic inflammation, hepatocyte ballooning, and liver fibrosis. Fasting blood glucose levels and steatosis scores were not affected by nocturnal hypoxia. There was no relationship between the respiratory disturbance index and insulin resistance or liver histopathology. CONCLUSIONS: Hypoxic stress of sleep apnea may be implicated in the development of insulin resistance and steatohepatitis in severe obesity.
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Hígado Graso/etiología , Resistencia a la Insulina , Obesidad Mórbida/complicaciones , Apnea Obstructiva del Sueño/etiología , Sueño/fisiología , Adulto , Anciano , Biopsia , Glucemia/metabolismo , Índice de Masa Corporal , Ensayo de Inmunoadsorción Enzimática , Hígado Graso/sangre , Hígado Graso/epidemiología , Femenino , Humanos , Insulina/sangre , Hígado/patología , Masculino , Maryland/epidemiología , Persona de Mediana Edad , Obesidad Mórbida/sangre , Obesidad Mórbida/patología , Pronóstico , Índice de Severidad de la Enfermedad , Apnea Obstructiva del Sueño/epidemiología , Apnea Obstructiva del Sueño/fisiopatología , Adulto JovenRESUMEN
Bacillus anthracis has been identified as a potential military and bioterror agent as it is relatively simple to produce, with spores that are highly resilient to degradation in the environment and easily dispersed. These characteristics are important in describing how anthrax could be used as a weapon, but they are also important in understanding and determining appropriate prevention and treatment of anthrax disease. Today, anthrax disease is primarily enzootic and found mostly in the developing world, where it is still associated with considerable mortality and morbidity in humans and livestock. This review article describes the spectrum of disease caused by anthrax and the various prevention and treatment options. Specifically we discuss the following; (1) clinical manifestations of anthrax disease (cutaneous, gastrointestinal, inhalational and intravenous-associated); (2) immunology of the disease; (3) an overview of animal models used in research; (4) the current World Health Organization and U.S. Government guidelines for investigation, management, and prophylaxis; (5) unique regulatory approaches to licensure and approval of anthrax medical countermeasures; (6) the history of vaccination and pre-exposure prophylaxis; (7) post-exposure prophylaxis and disease management; (8) treatment of symptomatic disease through the use of antibiotics and hyperimmune or monoclonal antibody-based antitoxin therapies; and (9) the current landscape of next-generation product candidates under development.
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A next-generation anthrax vaccine candidate, AV7909, is being developed for post-exposure prophylaxis (PEP) of inhalational anthrax in combination with the recommended course of antimicrobial therapy. Clinical efficacy studies of anthrax countermeasures in humans are not ethical or feasible, therefore, licensure of AV7909 for PEP is being pursued under the US Food and Drug Administration (FDA) Animal Rule, which requires that evidence of effectiveness be demonstrated in an animal model of anthrax, where results of studies in such a model can establish reasonable likelihood of AV7909 to produce clinical benefit in humans. Initial development of a PEP model for inhalational anthrax included evaluation of post-exposure ciprofloxacin pharmacokinetics (PK), tolerability and survival in guinea pigs treated with various ciprofloxacin dosing regimens. Three times per day (TID) intraperitoneal (IP) dosing with 7.5 mg/kg of ciprofloxacin initiated 1 day following inhalational anthrax challenge and continued for 14 days was identified as a well tolerated partially curative ciprofloxacin treatment regimen. The added benefit of AV7909 vaccination was evaluated in guinea pigs given the partially curative ciprofloxacin treatment regimen. Groups of ciprofloxacin-treated guinea pigs were vaccinated. 1 and 8 days post-challenge with serial dilutions of AV7909, a 1:16 dilution of AVA, or normal saline. A group of untreated guinea pigs was included as a positive control to confirm lethal B. anthracis exposure. Post-exposure vaccination with the AV7909 anthrax vaccine candidate administered in combination with the partially curative ciprofloxacin treatment significantly increased survival of guinea pigs compared to ciprofloxacin treatment alone. These results suggest that the developed model can be useful in demonstrating added value of the vaccine for PEP.
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Vacunas contra el Carbunco/administración & dosificación , Carbunco , Modelos Animales de Enfermedad , Profilaxis Posexposición , Infecciones del Sistema Respiratorio , Animales , Carbunco/prevención & control , Antibacterianos/farmacocinética , Ciprofloxacina/farmacocinética , Cobayas , Infecciones del Sistema Respiratorio/prevención & controlRESUMEN
Obstructive sleep apnoea (OSA) leads to chronic intermittent hypoxia (CIH) during sleep. Obstructive sleep apnoea has been associated with liver injury. Acetaminophen (APAP; known as paracetamol outside the USA) is one of the most commonly used drugs which has known hepatotoxicity. The goal of the present study was to examine whether CIH increases liver injury, hepatic oxidative stress and inflammation induced by chronic APAP treatment. Adult C57BL/6J mice were exposed to CIH or intermittent air (IA) for 4 weeks. Mice in both groups were treated with intraperitoneal injections of either APAP (200 mg kg(-1)) or normal saline daily. A combination of CIH and APAP caused liver injury, with marked increases in serum alanine aminotransferase, aspartate aminotransferase (AST), gamma-glutamyl transferase and total bilirubin levels, whereas CIH alone induced only elevation in serum AST levels. Acetaminophen alone did not affect serum levels of liver enzymes. Histopathology revealed hepatic necrosis and increased apoptosis in mice exposed to CIH and APAP, whereas the liver remained intact in all other groups. Mice exposed to CIH and APAP exhibited decreased hepatic glutathione in conjunction with a fivefold increase in nitrotyrosine levels, suggesting formation of toxic peroxynitrite in hepatocytes. Acetaminophen or CIH alone had no effect on either glutathione or nitrotyrosine. A combination of CIH and APAP caused marked increases in pro-inflammatory chemokines, monocyte chemoattractant protein-1 and macrophage inflammatory protein-2, which were not observed in mice exposed to CIH or APAP alone. We conclude that CIH and chronic APAP treatment lead to synergistic liver injury, which may have clinical implications for patients with OSA.
Asunto(s)
Acetaminofén/efectos adversos , Antiinflamatorios no Esteroideos/efectos adversos , Enfermedad Hepática Inducida por Sustancias y Drogas , Hipoxia/fisiopatología , Hepatopatías/fisiopatología , Acetaminofén/administración & dosificación , Acetaminofén/farmacología , Alanina Transaminasa/metabolismo , Animales , Antiinflamatorios no Esteroideos/administración & dosificación , Antiinflamatorios no Esteroideos/farmacología , Apoptosis/efectos de los fármacos , Apoptosis/fisiología , Aspartato Aminotransferasas/metabolismo , Citocinas/metabolismo , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Glutatión/metabolismo , Inyecciones Intraperitoneales , Hígado/efectos de los fármacos , Hígado/metabolismo , Hígado/patología , Hepatopatías/epidemiología , Masculino , Ratones , Ratones Endogámicos C57BL , Estrés Oxidativo/efectos de los fármacos , Estrés Oxidativo/fisiología , Factores de Riesgo , Apnea Obstructiva del Sueño/fisiopatologíaRESUMEN
The anthrax vaccine candidate AV7909 is being developed as a next-generation vaccine for a post-exposure prophylaxis (PEP) indication against anthrax. AV7909 consists of the anthrax vaccine adsorbed (AVA) (Emergent BioSolutions Inc., Lansing, MI) bulk drug substance adjuvanted with the immunostimulatory oligodeoxynucleotide (ODN) compound, CPG 7909. The addition of CPG 7909 to AVA enhances both the magnitude and the kinetics of antibody responses in animals and human subjects, making AV7909 a suitable next-generation vaccine for use in a PEP setting. Emergent has produced a thermostable (lyophilized) formulation of AV7909 vaccine utilizing drying technology. The purpose of the study described here was to assess the immunogenicity and efficacy of the lyophilized formulation of the AV7909 vaccine candidate as compared with the liquid formulation in the guinea pig general-use prophylaxis (GUP) model. The study also provides initial information on the relationship between the immune response induced by the thermostable formulation of the vaccine, as measured by the toxin neutralization assay (TNA), and animal survival following lethal anthrax aerosol challenge. Results demonstrated that there were no significant differences in the immunogenicity or efficacy of lyophilized AV7909 against lethal anthrax spore aerosol challenge in the guinea pig model as compared to liquid AV7909. For both vaccine formulations, logistic regression modeling showed that the probability of survival increased as the pre-challenge antibody levels increased.
Asunto(s)
Vacunas contra el Carbunco/química , Vacunas contra el Carbunco/inmunología , Anticuerpos Antibacterianos/sangre , Inmunogenicidad Vacunal , Temperatura , Adyuvantes Inmunológicos , Animales , Carbunco/prevención & control , Anticuerpos Neutralizantes/sangre , Antígenos Bacterianos/inmunología , Femenino , Liofilización , Cobayas , Masculino , Oligodesoxirribonucleótidos/inmunología , Profilaxis Posexposición , Vacunación , Potencia de la VacunaRESUMEN
Obstructive sleep apnea (OSA), a condition leading to intermittent hypoxia (IH) during sleep, has been associated with dyslipidemia, atherosclerosis, and increased cardiovascular mortality. We previously showed in C57BL/6J mice that IH causes hypercholesterolemia and upregulation of sterol regulatory element binding protein (SREBP)-1, a transcription factor of lipid biosynthesis in the liver. The goal of the present study was to provide mechanistic evidence that IH causes hypercholesterolemia via the SREBP-1 pathway. We utilized mice with a conditional knockout of SREBP cleavage-activating protein (SCAP) in the liver (L-Scap- mice), which exhibit low levels of an active nuclear isoform of SREBP-1 (nSREBP-1). We exposed L-Scap- mice and wild-type (WT) littermates to IH or intermittent air control for 5 days. IH was induced during the 12-h light phase by decreasing Fi(O(2)) from 20.9% to 5% for a period of 30 s with rapid reoxygenation to 20.9% through the subsequent 30 s. In WT mice, IH increased fasting levels of serum total and HDL cholesterol, serum triglycerides, serum and liver phospholipids, mRNA levels of SREBP-1 and mitochondrial glycerol-3-phosphate acyltransferase (mtGPAT), and protein levels of SCAP, nSREBP-1, and mtGPAT in the liver. In L-Scap- mice, IH did not have any effect on serum and liver lipids, and expression of lipid metabolic genes was not altered. We conclude that hyperlipidemia in response to IH is mediated via the SREBP-1 pathway. Our data suggest that the SREBP-1 pathway could be used as a therapeutic target in patients with both OSA and hyperlipidemia.
Asunto(s)
Dislipidemias/etiología , Hipoxia/metabolismo , Péptidos y Proteínas de Señalización Intracelular/deficiencia , Metabolismo de los Lípidos/fisiología , Proteínas de la Membrana/deficiencia , Proteína 1 de Unión a los Elementos Reguladores de Esteroles/fisiología , Animales , Cámaras de Exposición Atmosférica , Modelos Animales de Enfermedad , Dislipidemias/genética , Dislipidemias/metabolismo , Ayuno/sangre , Glicerol-3-Fosfato O-Aciltransferasa/metabolismo , Hipoxia/complicaciones , Hipoxia/genética , Péptidos y Proteínas de Señalización Intracelular/genética , Péptidos y Proteínas de Señalización Intracelular/fisiología , Metabolismo de los Lípidos/genética , Hígado/metabolismo , Masculino , Proteínas de la Membrana/genética , Proteínas de la Membrana/fisiología , Ratones , Ratones Noqueados , Ratones Transgénicos , Mitocondrias/enzimología , ARN Mensajero/biosíntesis , ARN Mensajero/genética , Recurrencia , Transducción de Señal/fisiología , Apnea Obstructiva del Sueño/metabolismo , Proteína 2 de Unión a Elementos Reguladores de Esteroles/biosíntesis , Proteína 2 de Unión a Elementos Reguladores de Esteroles/genéticaRESUMEN
Obstructive sleep apnea (OSA) is characterized by chronic intermittent hypoxia (CIH) and associated with dysregulation of lipid metabolisms and atherosclerosis. Causal relationships between OSA and metabolic abnormalities have not been established because of confounding effects of underlying obesity. The goal of the study was to determine if CIH causes lipid peroxidation and dyslipidemia in the absence of obesity and whether the degrees of dyslipidemia and lipid peroxidation depend on the severity of hypoxia. Lean C57BL/6J mice were exposed to CIH for 4 wk with a fractional inspired O2 (FI(O2)) nadir of either 10% (moderate CIH) or 5% (severe CIH). Mice exposed to severe CIH exhibited significant increases in fasting serum levels of total cholesterol (129 +/- 2.9 vs. 113 +/- 2.8 mg/dl in control mice, P < 0.05) and low-density lipoprotein cholesterol (85.7 +/- 8.9 vs. 56.4 +/- 9.7 mg/dl, P < 0.05) in conjunction with a 1.5- to 2-fold increase in lipoprotein secretion, and upregulation of hepatic stearoyl coenzyme A desaturase 1 (SCD-1). Severe CIH also markedly increased lipid peroxidation in the liver (malondialdehyde levels of 94.4 +/- 5.4 vs. 57.4 +/- 5.2 nmol/mg in control mice, P < 0.001). In contrast, moderate CIH did not induce hyperlipidemia or change in hepatic SCD-1 levels but did cause lipid peroxidation in the liver at a reduced level relative to severe CIH. In conclusion, CIH leads to hypercholesterolemia and lipid peroxidation in the absence of obesity, and the degree of metabolic dysregulation is dependent on the severity of the hypoxic stimulus.