401 research outputs found

    Feasibility Study on a Measurement Method and a Portable Measuring System to Estimate the Concentration of Cloxacillin and β -Lactamase in Milk

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    Antibiotics are nowadays used and abused worldwide in common veterinary practice to treat diseases, prevent infections, and promote animal's growth. Drug resistance occurrence is a relevant phenomenon that can inactivate the antibiotic. Moreover, antibiotics used for animals are also found in milk and it poses serious health risks to humans. Another negative effect is related to milk processors since antibiotics cause detrimental effects on cheese and yogurt starter bacteria. Given its consumption as both beverage and derivatives, milk is one of the most regulated products in food industry. Nowadays several commercial tests are available to investigate antibiotics in milk, but they generally provide a qualitative result, require bulky procedure, and are time consuming. In this paper, we investigate the use of a chromogenic cephalosporin to quantify the concentration of cloxacillin - a β-lactam difficult to be detected by using "cowside" screenings which is the drug of choice in the method of mastitis control. The proposed measurement method and prototype have been demonstrated to be able to detect cloxacillin in milk at concentrations lower than the MRL set by the European Commission. Moreover, they are also able to detect the illegal practice of using β-lactamase to degrade β-lactams in milk

    Functionalized multiwalled carbon nanotubes as ultrasound contrast agents

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    Ultrasonography is a fundamental diagnostic imaging tool in everyday clinical practice. Here, we are unique in describing the use of functionalized multiwalled carbon nanotubes (MWCNTs) as hyperechogenic material, suggesting their potential application as ultrasound contrast agents. Initially, we carried out a thorough investigation to assess the echogenic property of the nanotubes in vitro. We demonstrated their long-lasting ultrasound contrast properties. We also showed that ultrasound signal of functionalized MWCNTs is higher than graphene oxide, pristine MWCNTs, and functionalized single-walled CNTs. Qualitatively, the ultrasound signal of CNTs was equal to that of sulfur hexafluoride (SonoVue), a commercially available contrast agent. Then, we found that MWCNTs were highly echogenic in liver and heart through ex vivo experiments using pig as an animal model. In contrast to the majority of ultrasound contrast agents, we observed in a phantom bladder that the tubes can be visualized within a wide variety of frequencies (i.e., 5.5–10 MHz) and 12.5 MHz using tissue harmonic imaging modality. Finally, we demonstrated in vivo in the pig bladder that MWCNTs can be observed at low frequencies, which are appropriate for abdominal organs. Importantly, we did not report any toxicity of CNTs after 7 d from the injection by animal autopsy, organ histology and immunostaining, blood count, and chemical profile. Our results reveal the enormous potential of CNTs as ultrasound contrast agents, giving support for their future applications as theranostic nanoparticles, combining diagnostic and therapeutic modalities

    Analoghi chinossalinici omologhi del thymitaq e 2-(ariltio)chinossaline analoghe del trimetrexato e del metotrexato

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    Abbiamo progettato una nuove serie di chinossaline le quali possono comportarsi come bioisosteri delle pteridine e delle chinazoline dotate di attività antifolica, apparse recentemente in letteratura

    Group b streptococcus late-onset disease: 2003-2010

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    BACKGROUND: There is insufficient population-based data on group B streptococcus (GBS) late-onset disease (LOD). Risk factors and routes of GBS transmission are poorly understood. METHODS: A prospective, cohort study was conducted to collect incidence data on LOD and evaluate GBS infections over an 8-year period (2003-2010). Starting from January 2007, maternal rectovaginal and breast milk cultures were routinely collected on confirmation of the LOD diagnosis to assess maternal GBS culture status. RESULTS: The incidence rate of LOD was 0.32 per 1000 live births (1.4 and 0.24 per 1000 live births for preterm and term newborns, respectively). The registered cases of LOD (n = 100) were classified as sepsis (n = 57), meningitis (n = 36), or focal infection (n = 7). Thirty neonates were preterm (2 had recurrent infection); 68 were term. Four infants died (3 early preterm, 1 term). At the time the LOD diagnosis was confirmed, 3 (6%) of 53 mothers had GBS mastitis, and 30 (64%) of 47 carried GBS at the rectovaginal site. Early (7-30 days) LOD presentation was associated with neonatal brain lesions or death (odds ratio: 0.96 [95% confidence interval: 0.93-0.99]). Intrapartum antibiotic exposure was significantly associated with mild (12 of 22) rather than severe (11 of 45; P = .03) LOD. CONCLUSIONS: Preterm neonates had the highest rates of LOD and mortality. Most mothers carried GBS at the time of the LOD diagnosis, whereas 6% had mastitis. Intrapartum antibiotics were associated both with delayed presentation of symptoms and milder LOD. Pediatrics 2013;131:e361-e368Early neonatal mortality has remained high and unchanged for many years in Tanzania, a resource-limited country. Helping Babies Breathe (HBB), a novel educational program using basic interventions to enhance delivery room stabilization/resuscitation, has been developed to reduce the number of these deaths. METHODS: Master trainers from the 3 major referral hospitals, 4 associated regional hospitals, and 1 district hospital were trained in the HBB program to serve as trainers for national dissemination. A before (n = 8124) and after (n = 78 500) design was used for implementation. The primary outcomes were a reduction in early neonatal deaths within 24 hours and rates of fresh stillbirths (FSB). RESULTS: Implementation was associated with a significant reduction in neonatal deaths (relative risk [RR] with training 0.53; 95% confidence interval [CI] 0.43-0.65; P ≤.0001) and rates of FSB (RR with training 0.76; 95% CI 0.64-0.90; P = .001). The use of stimulation increased from 47% to 88% (RR 1.87; 95% CI 1.82-1.90; P ≤.0001) and suctioning from 15% to 22% (RR 1.40; 95% CI 1.33-1.46; P ≤.0001) whereas face mask ventilation decreased from 8.2% to 5.2% (RR 0.65; 95% CI 0.60- 0.72; P ≤ .0001). Copyright © 2013 by the American Academy of Pediatrics

    Targeting Class A and C Serine \u3b2-Lactamases with a Broad-Spectrum Boronic Acid Derivative

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    Production of \u3b2-lactamases (BLs) is the most widespread resistance mechanism adopted by bacteria to fight \u3b2-lactam antibiotics. The substrate spectrum of BLs has become increasingly broad, posing a serious health problem. Thus, there is an urgent need for novel BL inhibitors. Boronic acid transition-state analogues are able to reverse the resistance conferred by class A and C BLs. We describe a boronic acid analogue possessing interesting and potent broad-spectrum activity vs class A and C serine-based BLs. Starting from benzo(b)thiophene-2-boronic acid (BZBTH2B), a nanomolar non-\u3b2-lactam inhibitor of AmpC that can potentiate the activity of a third-generation cephalosporin against AmpC-producing resistant bacteria, we designed a novel broad-spectrum nanomolar inhibitor of class A and C BLs. Structure-based drug design (SBDD), synthesis, enzymology data, and X-ray crystallography results are discussed. We clarified the inhibitor binding geometry responsible for broad-spectrum activity vs serine-active BLs using double mutant thermodynamic cycle studies
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