ROTADIAL: The first nanobody-based immunoassay to detect Group A Rotavirus.

ROTADIAL is a rapid nanobody (Nb)-based ELISA assay able to identify Rotavirus group A (RVA) in feces from pediatric patients. The assay is based on a sandwich of two patented llama-derived Nbs directed to the inner capsid viral protein VP6 from RVA. Nbs are directed to conformational epitopes of VP6 and recognized all human RVA strains tested, representing ideal reagents for their use in immunodiagnostic tests for RVA detection. All the steps are carried out at room temperature, bringing results in less than two hours. This assay, named ROTADIAL, was validated with a reference panel of feces from pediatric patients from Argentina. The overall sensitivity and specificity of the ROTADIAL test, when compared to a commercial test, was 100 % (100/100) and 99 % (99/100) respectively. ROTADIAL presented optimal analytical performance, being capable of detecting RVA regardless of the presence of other common human enteric infectious agents and is the first RVA-diagnostic assay developed using Nbs, worldwide.

First assessment of all-cause acute diarrhoea and rotavirus-confirmed cases following massive vaccination in Argentina.

Argentina incorporated rotavirus massive vaccination in 2015. No specific strategy has been designed to accurately measure the impact of this recent introduction on the diarrhoeal disease burden in our country. We assessed post-vaccine introduction data (all-cause acute diarrhoea and rotavirus laboratory-confirmed cases, and genotype distribution), compared with pre-vaccination period in children under 5 years of age in Argentina. Cross-sectional ecologic analysis was conducted with data from the Argentine Surveillance Health System. Endemic channel and global and seasonal incidence rates of pre- and post-vaccination periods were calculated and further compared. Conventional binary genotypification on rotavirus-positive samples was also performed. In post-vaccination period, a global decrease of 20.8% in the rate of all-cause acute diarrhoea cases was found. The endemic channel showed that declination was more significant in the autumn/winter season. Rotavirus laboratory-confirmed cases showed 61.7% of reduction and the weekly distribution analyses indicated a significant flattening of the expected seasonal peak. G2P[4] was the most prevalent circulating genotype (57.2%). This study represents the first assessment of diarrhoeal disease burden since rotavirus massive vaccination strategy was implemented in Argentina. This introduction represented a successful intervention due to the significant decrease in all-cause acute diarrhoea cases and rotavirus laboratory-confirmed cases.

Complete genome analyses of G4P[6] rotavirus detected in Argentinean children with diarrhoea provides evidence of interspecies transmission from swine.

Rotaviruses are dynamic pathogens that have been shown to infect multiple species. In 2006, two G4P[6] rotavirus strains with porcine characteristics were detected in Santa Fe, Argentina. To further characterize and determine the origin of these strains, nearly the full length of their genome was sequenced. While most of the genome segments were from porcine origin, the two strains grouped in different phylogenetic clusters in five out of the 11 genes, suggesting two independent interspecies transmission events. This study expands our knowledge of G4 rotavirus and reinforces the use of complete genome analyses as a key tool for diversity and evolution mechanicisms.

Status asthmaticus in the medical intensive care unit: a 30-year experience.

OBJECTIVES: To investigate the characteristics, trends in management (permissive hypercapnia; mechanical ventilation (MV); neuromuscular blockade) and their impact on complications and outcomes in Status Asthmaticus (SA). METHODS: We performed a retrospective observational study of subjects admitted with SA to a single multidisciplinary MICU over a 30-year period. All laboratory, radiologic, respiratory care, physician notes and orders were extracted from an electronic medical record (EMR) maintained during the entire duration of the study. RESULTS: Two hundred and twenty-seven subjects were admitted with 280 episodes of SA. While subjects reflected our regional population (52% Hispanic), African Americans were over-represented (22%) and Caucasians under-represented (21%). Thirty-eight percent reported childhood asthma, 27% were steroid dependent (10% in the last 10 years), and 18% had a recent steroid taper. One hundred and thirty-nine (61.2%) required intubation. The duration of hospitalization was similar between mechanically ventilated and non-ventilated subjects (5.8±4.41 vs. 6.8±7.22 days; p=0.07). The overall complication rate remained low irrespective of the use of permissive hypercapnia or mode of mechanical ventilation (overall mortality 0.4%; pneumothorax 2.5%; pneumonia 2.9%). The frequency of SA declined significantly in the last 10 years of the study (12.4 vs. 3.2 cases/year). CONCLUSIONS: Despite the frequent use of mechanical ventilation, mortality/complication rates remained extremely low. MV did not significantly increase the duration of hospitalization. At our institution, the frequency of SA significantly decreased despite an increase in emergency room visits for asthma.

A novel human skin chamber model to study wound infection ex vivo.

Wound infections with multi-drug resistant bacteria increase morbidity and mortality and have considerable socioeconomic impact. They can lead to impaired wound healing, resulting in rising treatment costs. The aim of this study was to investigate an ex vivo human wound infection model. Human full-thickness skin from the operating room (OR) was placed into the Bo-Drum and cultivated for 7 days in an air-liquid interphase. On day 8, the skin was inoculated with either (1) Pseudomonas aeruginosa, (2) Staphylococcus aureus (10(5) CFU, n = 3) or (3) carrier control. 1, 3 and 7 days after inoculation colony forming units in the tissue/media were determined and cytokine expression was quantified. A reliable and reproducible wound infection could be established for 7 days. At this time point, 1.8 x 10(8) CFU/g tissue of P. aeruginosa and 2 x 10(7) CFU/g tissue of S. aureus were detected. Immunohistochemical analysis demonstrated bacterial infection and epidermolysis in infected skin. RT-PCR analysis exhibited a significant induction of proinflammatory cytokines after infection. The BO-drum is a robust, easy-to-use, sterilizable and reusable ex vivo full-skin culture system. For investigation of wound infection, treatment and healing, the BO-drum presents a convenient model and may help to standardize wound research.

Asthma in US seniors: part 2. Treatment. Seeing through the glass darkly.

BACKGROUND: We sought to identify the best evidence for treatment of asthmatic patients aged 65 years or more. METHODS: We used computer-assisted searches to identify randomized, controlled trials for asthma in the elderly that were published in English between 1950 and 2008. RESULTS: Small trials of an inhaled corticosteroid versus a leukotriene antagonist and an oral beta(2)-agonist versus placebo compose the controlled trial data on asthma therapy in seniors. Epidemiologic evidence suggests that the side effects of corticosteroids and beta-agonists may be more common in the elderly than in younger populations. CONCLUSION: Seniors with asthma or comorbid conditions that are common in the elderly have been systematically excluded from asthma treatment trials. There is no compelling evidence to demonstrate the superiority of any pharmacologic therapy in these asthmatic patients. Evaluation of response to asthma treatment in clinical trials remains primarily symptom-based when symptoms have been shown to underestimate the severity of disease in seniors.

Caracterización molecular de calicivirus aislados de brotes de gastroenteritis ocurridos en la Argentina durante los años 2005 y 2006 / Molecular characterization of calicivirus strains detected in outbreaks of gastroenteritis occurring in Argentina during 2005 and 2006

Con el objetivo de determinar la incidencia de calicivirus, rotavirus y astrovirus en brotes de gastroenteritis ocurridos en diversas regiones de la Argentina durante los años 2005 y 2006, se analizaron muestras de materia fecal provenientes de 7 brotes con resultado de coprocultivo negativo. Para el diagnóstico de rotavirus se utilizó un ELISA comercial, mientras que para el diagnóstico de calicivirus y astrovirus se utilizó el método de RT-PCR. De las 74 muestras analizadas, 20 fueron positivas para calicivirus, 17 para rotavirus y una para astrovirus. No se identificaron infecciones virales mixtas. En 5 muestras positivas para calicivirus se secuenció una región del gen de la polimerasa; 4 de ellas correspondieron al género Norovirus y una al género Sapovirus. El análisis filogenético de las muestras secuenciadas determinó la presencia de norovirus de los genogrupos GI y GII; dentro de este último, se identificaron los genotipos GII-4, GII-b y GII-17. El análisis de la muestra en la cual se identificó sapovirus reveló la presencia del genotipo GI-1. Este estudio representa una continuación del análisis epidemiológico molecular de calicivirus asociados a brotes de gastroenteritis iniciado en 2004 y constituye la primera comunicación de la circulación de norovirus del genotipo GII-17 en la Argentina.

In order to determine the incidence of calicivirus, rotavirus and astrovirus in outbreaks of gastroenteritis occurring in different regions of Argentina during 2005 and 2006, fecal samples from seven nonbacterial outbreaks were analyzed. A commercial ELISA was used for rotavirus detection, while RT-PCRs were used for calicivirus and astrovirus. Of the 74 samples analyzed, 20 were calicivirus positive, 17 were rotavirus positive and one was astrovirus positive. No mixed infections were detected. A partial region of the RdRp gene was sequenced in five calicivirus positive-samples; 4 of them belonged to Norovirus genus and one to Sapovirus genus. The phylogenetic analysis of norovirus-positive-samples revealed the presence of strains from genogroups GI and GII; genotypes GII- 4, GII-b and GII-17 were identified within the latter. Phylogenetic the sapovirus-positive-sample revealed the presence of genotype GI-1. This study represents a follow-up of the of molecular epidemiology analysis of calicivirus associated to gastroenteritis outbreaks that have been carried out by our group since 2004, and constitutes the first report of the circulation of genotype GII-17 in Argentina.

[Molecular characterization of calicivirus strains detected in outbreaks of gastroenteritis occurring in Argentina during 2005 and 2006]. / Caracterización molecular de calicivirus aislados de brotes de gastroenteritis ocurridos en la Argentina durante los años 2005 y 2006.

In order to determine the incidence of calicivirus, rotavirus and astrovirus in outbreaks of gastroenteritis occurring in different regions of Argentina during 2005 and 2006, fecal samples from seven nonbacterial outbreaks were analyzed. A commercial ELISA was used for rotavirus detection, while RT-PCRs were used for calicivirus and astrovirus. Of the 74 samples analyzed, 20 were calicivirus positive, 17 were rotavirus positive and one was astrovirus positive. No mixed infections were detected. A partial region of the RdRp gene was sequenced in five calicivirus positive-samples; 4 of them belonged to Norovirus genus and one to Sapovirus genus. The phylogenetic analysis of norovirus-positive-samples revealed the presence of strains from genogroups GI and GII; genotypes GII-4, GII-b and GII-17 were identified within the latter. Phylogenetic the sapovirus-positive-sample revealed the presence of genotype GI-1. This study represents a follow-up of the of molecular epidemiology analysis of calicivirus associated to gastroenteritis outbreaks that have been carried out by our group since 2004, and constitutes the first report of the circulation of genotype GII-17 in Argentina.

Pyrolytic carbon indentation crack morphology.

In studying fatigue and fracture behavior of brittle materials, Vickers diamond indentation cracks are often used. Many of the studies of indentation cracks use crack system models such as the radial-median crack or Palmqvist crack. These systems are also used to study small crack growth in brittle materials, and have been studied for pyrolytic carbon. However, the true morphology of these cracks in pyrolytic carbon coatings on graphite substrates have not been described. This study examined Vickers diamond and spherical ball indentation cracks in pyrolytic carbon coatings using several techniques, including serial metallographic cross sections, indentation fracture in bending, acoustic emission, and residual surface indentation scanning. The crack systems developed using these techniques were not typical of either radial median or Palmqvist systems. The morphology is unique to this material, possibly because of the coating thickness limitations. Given the difference in crack system, the application of standard indentation crack equations in studying fracture mechanics, especially for small cracks, must be questioned.

[Variation in the R-R intervals on the electrocardiogram. A new diagnostic method in cardiology]. / Variabilita intervalu R-R elektrokardiogramu. Novejsí pomocná diagnostická metoda v kardiologii.

Periodic heart rate fluctuation depends on the oscillation of sympathetic and vagal activation of the heart. Periodic retardation and acceleration of heart rate related to respiration and to blood pressure changes can be registered on the ECG as the "variability of R-R intervals". Testing procedures of the variability of R-R intervals at rest, during deep breathing, daily activities, during exercise and other stress tests are described in the paper. For the evaluation of the R-R interval's variability, current statistical methods are used (e.g. mean with standard deviation, variation coefficient, mean beat to beat differences in R-R intervals etc.). Power spectral analysis in the variability of 200-600 successive R-R intervals commonly performed today uses either rapid Fourier transformation or the autoregulation model. The analysis shows high- and low frequency peaks corresponding to the rapid and slow oscillations in heart rate. Evaluation of the R-R interval variability, especially using power spectrum analysis, gave good results in testing drugs, e.g., beta blockers, calcium antagonists and antiarrhythmic drugs. Variability of R-R intervals is reduced in conditions affecting the cardiac autonomous nervous system such as diabetes. It is also decreased in patients with ischaemic heart disease and in those with cardiac failure of different aetiology. The decrease is not an expression of the disease itself: it shows an alteration in neurovegetative tonicity in the particular disease condition. The decreased variability of R-R intervals in patients with ischaemic heart disease has an important prognostic value. The predominance of the sympathetic over the depressed vagal activity signalizes an increased risk of sudden coronary death.

Transoesophageal atrial pacing in the diagnosis of myocardial ischaemia assessed with the 12-lead electrocardiogram and precordial ST segment mapping.

In order to diagnose myocardial ischaemia, the authors performed transoesophageal atrial pacing using commercially available electrodes and a pacing device of their own design. On assessing the 12-lead electrocardiogram, they compared the results of pacing and exercise testing in 204 subjects. They found full agreement in all controls and in most IHD patients. In 33 persons, atrial pacing was combined with assessment of the ST segment precordial mapping. On atrial pacing mapping, the authors found manifestations of ischaemia similar to those discovered during exercise testing. Both methods have proved useful in the detection of myocardial ischaemia and are recommended as alternative techniques to exercise testing, especially in cases when the latter technique is not feasible or cannot be interpreted.

[Diagnosis of myocardial ischemia using functional ST mapping and 201Tl stress scintigraphy]. / Diagnostika ischemie myokardu pracovní ST mapou a zátezou scintigrafií 201Tl.

The authors compared the value of two non-invasive methods in the diagnosis of myocardial ischaemia, i.e. precordial working maps of the ST segment and working scintigraphy of the myocardium with 201T1 after a load. On comparison with the finding on the coronary arteries, the authors found a high sensitivity of mapping, 89.3%, and of 201T1 scan, 92.9%, while the specificity of both methods was lower, 57.1%. Both methods are equally valuable for diagnosis of myocardial ischaemia; for assessment of the site of affection thallium scintigraphy of the myocardium is preferable.