Intestinal hydrogen and nitric oxide gases in preterm infants - Effects of antibiotic therapy

Objective: Measurements of hydrogen (H 2) and nitric oxide (NO) levels in intestinal gas have recently been shown to be useful to monitor bacterial colonization in healthy term newborn infants. The significance of preterm birth and antibiotic therapy for intestinal gas production is not known and was the subject of this study. Methods: A minimally invasive tonometric technique was used for repeated measurements (44 samples) of luminal colonic H 2 and NO in 23 preterm infants with gestational age 27-35 weeks, birth weight 1,170-2,996 g and postnatal age 2-31 days. Results: The measuring procedure was well tolerated in all infants. Intestinal H 2 was 300 (4-1,990) ppm and NO was 34 (11-82) ppb. Intestinal H 2 and NO increased during the first week (p < 0.05) to average levels that in the case of H 2, exceeded those of healthy, term infants. In preterm infants treated with antibiotics (n = 12), H 2 and NO levels were significantly lower than in those without such therapy (p < 0.05). Conclusion: These observations suggest that intestinal measurements of H 2 and NO may be used to monitor birth-related bacterial colonization in relation to postnatal age, maturation and antibiotic therapy. In preterm infants, gaseous distension of the gut is common and may signal bacterial overgrowth. The potential role of intestinal gas measurements as a diagnostic tool for intestinal disorders remains to be clarified. Copyright © 2008 S. Karger AG.link_to_subscribed_fulltex

Replicated data-matrix array generators

The fabrication and replication of binary spot array generators using 4 and 16 levels gratings is investigated. The elements are designed using iterative Fourier transform algorithm and fabricated by electron-beam lithography. Finally elements are copied by fabricating nickel shims and using hot embossing technique. In each step the optical signals are measured and signals are characterized using bit error rate as a measure of quality. The results show that although 16 level element gives theoretically superior performance, the bit error rate is much lower (∼0.2%) for replicated 4 level elements than for their 16 level counterparts (∼9%)

Inference of type-specific HPV transmissibility, progression and clearance rates: a mathematical modelling approach.

Quantifying rates governing the clearance of Human Papillomavirus (HPV) and its progression to clinical disease, together with viral transmissibility and the duration of naturally-acquired immunity, is essential in estimating the impact of vaccination programmes and screening or testing regimes. However, the complex natural history of HPV makes this difficult. We infer the viral transmissibility, rate of waning natural immunity and rates of progression and clearance of infection of 13 high-risk and 2 non-oncogenic HPV types, making use of a number of rich datasets from Sweden. Estimates of viral transmissibility, clearance of initial infection and waning immunity were derived in a Bayesian framework by fitting a susceptible-infectious-recovered-susceptible (SIRS) transmission model to age- and type-specific HPV prevalence data from both a cross-sectional study and a randomised controlled trial (RCT) of primary HPV screening. The models fitted well, but over-estimated the prevalence of four high-risk types with respect to the data. Three of these types (HPV-33, -35 and -58) are among the most closely related phylogenetically to the most prevalent HPV-16. The fourth (HPV-45) is the most closely related to HPV-18; the second most prevalent type. We suggest that this may be an indicator of cross-immunity. Rates of progression and clearance of clinical lesions were additionally estimated from longitudinal data gathered as part of the same RCT. Our estimates of progression and clearance rates are consistent with the findings of survival analysis studies and we extend the literature by estimating progression and clearance rates for non-16 and non-18 high-risk types. We anticipate that such type-specific estimates will be useful in the parameterisation of further models and in developing our understanding of HPV natural history

Differences in risk for SARS-CoV-2 infection among healthcare workers

Abstract Healthcare workers (HCWs) are a risk group for SARS-CoV-2 infection, but which healthcare work that conveys risk and to what extent such risk can be prevented is not clear. Starting on April 24th, 2020, all employees at work (n = 15,300) at the Karolinska University Hospital, Stockholm, Sweden were invited and 92% consented to participate in a SARS-CoV-2 cohort study. Complete SARS-CoV-2 serology was available for n = 12,928 employees and seroprevalences were analyzed by age, sex, profession, patient contact, and hospital department. Relative risks were estimated to examine the association between type of hospital department as a proxy for different working environment exposure and risk for seropositivity, adjusting for age, sex, sampling week, and profession. Wards that were primarily responsible for COVID-19 patients were at increased risk (adjusted OR 1.95 (95% CI 1.65–2.32) with the notable exception of the infectious diseases and intensive care units (adjusted OR 0.86 (95% CI 0.66–1.13)), that were not at increased risk despite being highly exposed. Several units with similar types of work varied greatly in seroprevalences. Among the professions examined, nurse assistants had the highest risk (adjusted OR 1.62 (95% CI 1.38–1.90)). Although healthcare workers, in particular nurse assistants, who attend to COVID-19 patients are a risk group for SARS-CoV-2 infection, several units caring for COVID-19 patients had no excess risk. Large variations in seroprevalences among similar units suggest that healthcare work-related risk of SARS-CoV-2 infection may be preventable

Resource selection by sympatric free-ranging dairy cattle and brown bears

Livestock depredation is an important factor that contributes to low public acceptance of large carnivores, and is often used as an incentive to reduce large carnivore populations. In central Sweden, brown bears (Ursus arctos) coexist with a traditional cattle husbandry system that allows daytime free-ranging of dairy cattle. Despite a growing brown bear population, depredation on cattle remained stable during the last decade, and among the lowest rates reported worldwide. Nevertheless, major stakeholders argue for a substantial reduction in brown bear numbers, among other reasons, to safeguard this traditional husbandry system. Based on satellite tracking data, we assessed and correlated the resource selection of nine brown bears that were sympatric with six daytime free-ranging cattle herds during the free-ranging season (June-August) in 2008. We found a significant and negative relationship between resource selection of brown bears and free ranging cattle during the study period, mainly because of inverse relationships between the species towards vegetation density and human-related infrastructure, such as forest roads, buildings, and settlements. We predict that the probability of an encounter between these species, given that there is no directed predation, is highest in dense vegetation patches close to these human habitation-related variables. Because of the low reported depredation rates and the apparent habitat segregation between the species, our results provide no support for the argument to reduce brown bear numbers to safeguard this traditional cattle herding system