RESUMO
Nitric oxide has bactericidal and virucidal properties. Nasal instillation of a nitric oxide releasing solution (NORS) on arrival at the feedlot was recently reported as inferior to a parenteral injection of tilmicosin (macrolide antibiotic) for control of bovine respiratory disease (BRD) in cattle at high-risk of developing BRD. We hypothesized that this inferiority was due to differences between treatments with regards to their effects on the nasopharyngeal microbiota. The objective was to compare nasal instillation of NORS versus parenteral administration of tilmicosin regarding their effects on the nasopharyngeal microbiota of feedlot cattle at high-risk of developing BRD. Culture-independent community profiling (16S rRNA sequencing) and culture-based methods were used to evaluate treatment effects. High-risk Angus-cross heifers (n=20) were randomly allocated to 2 treatment groups on arrival at a feedlot and received either NORS or tilmicosin for prevention of BRD. Heifers were sampled using guarded deep nasal swabs immediately prior to treatment (day 0) and on days 1, 5 and 10 after treatment. Based on culture-independent community profiling, there was a distinct shift in composition of the nasopharyngeal microbiota during the first 10 d after arrival, with 116 OTUs changing over time, but no difference between treatment groups. However, culture-based methods detected a difference between treatment groups, with more cattle culture-positive for Pasteurellaceae in the NORS group at day 5 post-treatment. This difference in ability to inhibit colonization of the nasopharynx by Pasteurellaceae may be the basis for NORS being inferior to tilmicosin for control of BRD in high-risk cattle.
Assuntos
Complexo Respiratório Bovino/prevenção & controle , Microbiota/efeitos dos fármacos , Nasofaringe/microbiologia , Óxido Nítrico/farmacologia , Tilosina/análogos & derivados , Animais , Antibacterianos/administração & dosagem , Antibacterianos/farmacologia , Complexo Respiratório Bovino/microbiologia , Bovinos , Feminino , Óxido Nítrico/administração & dosagem , Óxido Nítrico/química , RNA Bacteriano/genética , RNA Ribossômico 16S/genética , Fatores de Risco , Tilosina/administração & dosagem , Tilosina/farmacologiaRESUMO
Undifferentiated fever, or bovine respiratory disease complex (BRDc), is a challenging multi-factorial health issue caused by viral/bacterial pathogens and stressors linked to the transport and mixing of cattle, negatively impacting the cattle feedlot industry. Common practice during processing at feedlots is administration of antibiotic metaphylaxis to reduce the incidence of BRDc. Nitric oxide (NO) is a naturally occurring nano-molecule with a wide range of physiological attributes. This study evaluated the metaphylactic use of intranasal NO releasing spray (NORS) to control BRDc incidence in calves at low-moderate risk of developing BRDc, arriving at a commercial feedlot as compared to conventional antibiotic metaphylaxis. One thousand and eighty crossbred, multiple-sourced, commingled, commercial, weaned beef calves were screened, enrolled, randomized and treated upon arrival. Animals appearing sick were pulled (from their pen) by blinded pen keepers then assessed for BRDc symptoms; blood samples were taken for haptoglobin quantification and the animals were rescued with an antibiotic. After 35 days both groups showed no significant difference in BRDc incidence (5.2% of animals from NORS group and 3.2% from antibiotic group). Average daily weight gain of animals at day 150 for the NORS cohort was 1.17kg compared to 1.18kg for the antibiotic group (p>0.05). There was no significant difference in mortality in the first 35 days (p=0.7552), however, general mortality over 150 days trended higher in the antibiotic cohort. NORS treatment was shown to be safe, causing neither distress nor adverse effects on the animals. This large randomized controlled study in low-moderate BRDc incidence risk calves demonstrates that NORS treatment, as compared to conventional metaphylactic antibiotics, is non-inferior based on BRDc incidence and other metrics like weight and mortality. These data justify further studies in higher BRDc incidence risk populations to evaluate NORS as an alternative strategy to reduce sub-therapeutic metaphylaxis antibiotic use in beef cattle production.
Assuntos
Antibacterianos/uso terapêutico , Antibioticoprofilaxia/veterinária , Complexo Respiratório Bovino/prevenção & controle , Broncodilatadores/uso terapêutico , Febre/prevenção & controle , Óxido Nítrico/uso terapêutico , Alberta/epidemiologia , Análise de Variância , Animais , Peso Corporal , Complexo Respiratório Bovino/epidemiologia , Complexo Respiratório Bovino/mortalidade , Bovinos , Distribuição Aleatória , Resultado do TratamentoRESUMO
Nitric oxide, a molecule produced in most mammalian cells, has bactericidal and virucidal properties. Nasal instillation of a nitric oxide releasing solution (NORS) on arrival at the feedlot was recently reported as non-inferior to a parenteral injection of a macrolide antibiotic, tilmicosin, for control of bovine respiratory disease (BRD) in cattle at low-to-moderate risk of developing BRD. The objective of this study was to evaluate whether NORS was non-inferior to tilmicosin for control of BRD in cattle at high-risk of developing BRD (the target population for many BRD control programs). High-risk Angus-cross heifers (n=840) were randomly allocated to 2 treatment groups on arrival at a feedlot and received either NORS or tilmicosin for BRD control. Non-inferiority was assessed by calculating the difference in prevalence of heifers diagnosed with BRD during the first 40 d after arrival between NORS and tilmicosin treatment groups. The non-inferiority margin (δ) was set at 8.5%. Thirty-six and 19% of heifers were diagnosed with BRD in the NORS and tilmicosin groups, respectively. Because the lower bound of the 2-sided 95% confidence interval (CI) of the difference in BRD prevalence between the 2 treatment groups (17%; 95% CI=11-23%) was higher than δ, an inferiority of NORS was concluded. Although on-arrival nasal administration of NORS can be viewed as a more rational control strategy than parental injection of antibiotics, further research is needed to improve NORS efficacy before it can be recommended to prevent BRD in high-risk cattle.
Assuntos
Antibacterianos/uso terapêutico , Complexo Respiratório Bovino/prevenção & controle , Óxido Nítrico/uso terapêutico , Tilosina/análogos & derivados , Animais , Antibacterianos/administração & dosagem , Complexo Respiratório Bovino/etiologia , Bovinos , Feminino , Óxido Nítrico/administração & dosagem , Prevalência , Tilosina/administração & dosagem , Tilosina/uso terapêuticoRESUMO
BACKGROUND: Many behavioral and physiological studies of laboratory mice employ invasive methods such as radio telemetry to measure key aspects of behavior and physiology. Radio telemetry requires surgical implants, which may impact mouse health and behavior, and thus reduce the reliability of the data collected. NEW METHOD: We developed a method to measure key aspects of thermoregulatory behavior without compromising animal welfare. We examined the thermoregulatory response to heat stress in a custom-built arena that permitted the use of simultaneous and continuous infrared thermography (IRT) and video capture. This allowed us to measure changes in surface body temperature and determine total distance traveled using EthoVision XT animal tracking software. RESULTS: Locomotor activity and surface body temperature differed between heat-stressed mice and mice kept within their thermal comfort zone. The former had an increase in surface body temperature and a decline in locomotor activity, whereas the latter had a stable surface body temperature and showed greater activity levels. METHODS: Surface body temperature and locomotor activity are conventionally quantified by measurements taken at regular intervals, which limit the use and accuracy of the data. We obtained data of high resolution (i.e., recorded continuously) and accuracy that allowed for the examination of key physiological measurements such as energy expenditure and peripheral vasomotor tone. CONCLUSIONS: This novel experimental method for studying thermoregulatory behavior in mice using non-invasive tools has advantages over radio-telemetry and represents an improvement in laboratory animal welfare.
Assuntos
Actigrafia/métodos , Comportamento Animal , Modelos Animais de Doenças , Transtornos de Estresse por Calor , Termografia/métodos , Gravação em Vídeo/métodos , Ar , Animais , Comportamento Animal/fisiologia , Temperatura Corporal , Regulação da Temperatura Corporal , Feminino , Transtornos de Estresse por Calor/fisiopatologia , Transtornos de Estresse por Calor/psicologia , Temperatura Alta , Raios Infravermelhos , Luz , Camundongos Endogâmicos C57BL , Atividade Motora/fisiologia , Pigmentação/fisiologia , SoftwareRESUMO
Bovine Respiratory Disease Complex (BRDc), a multi-factorial disease, negatively impacts the cattle industry. Nitric oxide (NO), a naturally occurring molecule, may have utility controlling incidence of BRDc. Safety, bioavailability, toxicology and tolerance/stress of administering NO to cattle is evaluated herein. Thirteen, crossbred, multiple-sourced, commingled commercial weaned beef calves were treated multiple times intranasally over a 4 week period with either a nitric oxide releasing solution (treatment) or saline (control). Exhaled NO, methemoglobin percent (MetHg) and serum nitrites demonstrated biological availability as a result of treatment. Cortisol levels, tissue nitrites, behavior and gross and macroscopic pathology of organs were all normal. Moreover, preliminary in vitro studies using Mannheimia haemolytica, Infectious Bovine Rhinotracheitis, Bovine Parainfluenza-3 and Bovine Respiratory Syncytial Virus, suggest a potential explanation for the previously demonstrated efficacy for BRDc. These data confirm the bioavailability, safety and lack of residual of NO treatment to cattle, along with the bactericidal and virucidal effects.
Assuntos
Complexo Respiratório Bovino/tratamento farmacológico , Pulmão/microbiologia , Pulmão/virologia , Óxido Nítrico/farmacologia , Administração Intranasal , Animais , Comportamento Animal/efeitos dos fármacos , Complexo Respiratório Bovino/microbiologia , Complexo Respiratório Bovino/virologia , Bovinos , Histocitoquímica/veterinária , Hidrocortisona/sangue , Metemoglobina/análise , Óxido Nítrico/administração & dosagem , Óxido Nítrico/uso terapêutico , Nitritos/sangue , Gravação em VídeoRESUMO
Environmental factors were evaluated to determine potential limitations in using cattle eye temperatures obtained through infrared thermography (IRT) for early disease detection systems or in animal welfare research studies. The effects of the following factors on IRT eye temperatures in cattle and a fabricated surrogate "eye" were evaluated: camera to object distance, wind speed, camera settings (distance, emissivity, and humidity), and solar loading. Wind speed in both live animals and using a surrogate "eye" was found to decrease the IRT temperature. In the presence of â¼ 7 km/h wind, the mean IRT eye temperature decreased by 0.43 ± 0.13 °C and; at higher wind speeds (â¼ 12 km/h), the temperature decreased by 0.78 ± 0.33 °C. Direct sunlight was found to increase the IRT eye temperature by 0.56 ± 0.36 °C. It was determined that environmental factors impact IRT temperature measurements significantly and therefore must be managed to ensure reproducible and accurate readings.
Assuntos
Temperatura Corporal/fisiologia , Bovinos/fisiologia , Fenômenos Fisiológicos Oculares , Termografia/veterinária , Animais , Feminino , Masculino , Análise de Regressão , Luz Solar , VentoRESUMO
Bovine respiratory disease complex (BRDc), is a challenging multi-factorial health issue caused by viral/bacterial pathogens and stressors linked with the transport and mixing of cattle, negatively impacting the cattle feedlot industry. Nitric oxide (NO) is a naturally occurring molecule with antimicrobial attributes. This study tests whether NO can prevent the symptoms associated with BRDc. Eighty-five, crossbred, multiple-sourced, commingled commercial weaned beef calves were monitored and scored for temperature, white blood count, clinical score, hematology, cortisol levels and neutrophil/lymphocyte ratio. NO treatment or placebo were given once on arrival to the stockyard. After one week 87.5% of sick animals were from the control while 12.5% from treatment groups and after two weeks 72% and 28% respectively. Treatment was shown to be safe, causing neither distress nor adverse effects on the animals. These data show that NO treatment on arrival to the feedlot significantly decreased the incidence of BRDc in this study.
Assuntos
Complexo Respiratório Bovino/prevenção & controle , Óxido Nítrico/farmacologia , Administração por Inalação , Animais , Bovinos , Abrigo para Animais , Óxido Nítrico/administração & dosagem , Estresse Fisiológico , Fatores de TempoRESUMO
AIMS: To test a nitric oxide-releasing solution (NORS) as a potential antifungal footbath therapy against Trichophyton mentagrophytes and Trichophyton rubrum during the mycelial and conidial phases. METHODS AND RESULTS: NORS (sodium nitrite citric acid) produces nitric oxide verified by gas chromatography and mass spectrometry (GC-MS). Antifungal activity of this solution was tested against mycelia and conidia of T. mentagrophytes and T. rubrum, using 1-20 mmol l(-1) nitrites and 10-30 min exposure times. The direct effect of the gas released from the solution on the viability of those fungi was tested. NORS demonstrated strong antifungal activity and was found to be dose and time dependent. NO and nitrogen dioxide (NO(2) ) were the only gases detected from this reaction and are likely responsible for the antifungal effect. CONCLUSIONS: This in vitro research suggests that a single 20-min exposure to NORS could potentially be used as an effective single-dose treatment against fungi that are associated with tinea pedis in both mycelia and spore phase. SIGNIFICANCE AND IMPACT OF THE STUDY: This study provides the background for developing a user-friendly footbath treatment for Athlete's Foot that will kill both vegetative fungi and its spores.
Assuntos
Antifúngicos/farmacologia , Óxido Nítrico/metabolismo , Trichophyton/efeitos dos fármacos , Antifúngicos/química , Antifúngicos/uso terapêutico , Humanos , Tinha dos Pés/tratamento farmacológico , Tinha dos Pés/microbiologia , Trichophyton/crescimento & desenvolvimentoRESUMO
OBJECTIVE: To investigate the frequency, predisposing factors, clinical presentation, and outcome of abdominal compartment syndrome (ACS) in critically ill pediatric patients. DESIGN: A prospective study over a 5-yr period. SETTING: Pediatric intensive care unit of a tertiary care, university hospital. PATIENTS: All patients admitted to the pediatric intensive care unit were screened for the presence of ACS and were treated with a uniform protocol. ACS was defined as abdominal distention with intra-abdominal pressure (IAP) > 15 mm Hg, accompanied by at least two of the following: oliguria or anuria; respiratory decompensation; hypotension or shock; metabolic acidosis. MEASUREMENTS AND MAIN RESULTS: Of 1762 patients admitted over 5 yrs, ten patients (0.6%) had a total of 15 episodes of ACS. Of 406 trauma cases, three had ACS (0.7%). Three of the ten patients had primary abdominal conditions (mesenteric vein thrombosis, intussusception, enterocolitis), three had abdominal surgery (trauma, Kasai operation, esophageal perforation and peritonitis), three had primary central nervous system involvement, and one had meningococcemia. At laparotomy, bowel ischemia or necrosis was found in four episodes of ACS (27%). Mean IAP at diagnosis of ACS was 23.9 +/- 3.8 (range 17-31) mm Hg. Physiologic parameters were compared during 4 hrs before the development of ACS, during ACS, and after abdominal decompression. Mean arterial pressure, Pao(2), Pao(2)/Fio(2) ratio, and urinary output decreased significantly, whereas Paco(2), peak inspiratory pressures, positive end-expiratory pressures, and base deficit increased significantly after the development of ACS. After decompressive laparotomy, the condition of the patients improved promptly and these variables returned to pre-ACS values. Overall mortality rate in this group was 60%. CONCLUSIONS: Although relatively infrequent compared with adults, ACS occurs in critically ill children. Timely decompression of the abdomen results in uniform improvement, but overall mortality is still high. In contrast with adults, children with ACS have diverse primary diagnoses, with a significant number of primary extra-abdominal-mainly central nervous system-conditions. Ischemia and reperfusion injury appear to be the major mechanisms for development of ACS in children. Clinical presentation is similar to adults, but children may develop ACS at a lower IAP (as low as 16 mm Hg).
RESUMO
A pulse oximeter was used to detect safe margins for resection of a strangulated stomach. The sensor probe was placed intraoperatively on various portions of the stomach, which herniated through a left lateral diaphragmatic defect. Failure to detect blood flow by this device in equivocally compromised tissue helped in the assessment of safe viable margins for resection.
Assuntos
Hérnia Diafragmática/complicações , Isquemia/diagnóstico , Monitorização Intraoperatória/métodos , Oximetria , Estômago/irrigação sanguínea , Feminino , Gastrectomia , Hérnia Diafragmática/cirurgia , Humanos , Lactente , Isquemia/etiologia , Isquemia/cirurgia , Estômago/cirurgiaRESUMO
In a search of features that might be relevant to the understanding of the hyperbilirubinaemia of infants with hypertrophic pyloric stenosis (HPS), we examined the duodenal fluid in 11 infants with this condition. Four (36%) had an unconjugated bilirubin level above 2.5 mg/dl in the serum. Levels of electrolytes, bicarbonate, liver function tests and cholesterol were similar in the jaundiced and the non-icteric infants. Examination of duodenal fluid for pH, concentration of bilirubin, bile salts, electrolytes and beta-glucuronidase levels also did not disclose any significant differences between the HPS patients and the controls. Bacterial culture of the fluid yielded similar results in both groups. We may conclude that the unconjugated hyperbilirubinaemia observed in some patients with HPS is not associated with overgrowth of bacteria, changes in glucuronidase levels, pH, electrolytes or biliary obstruction.