A pilot study using a mouse mastitis model to study differences between bovine associated coagulase-negative staphylococci

Coagulase-negative staphylococci (CNS) are a group of bacteria classified as either minor mastitis pathogens or commensal microbiota. Recent research suggests species-and even strain-related epidemiological and genetic differences within the large CNS group. The current pilot study investigated in 2 experiments whether a mouse mastitis model validated for bovine Staphylococcus aureus can be used to explore further differences between CNS species and strains. In a first dose titration experiment, a low inoculum dose of S. aureus Newbould 305 (positive control) was compared with increasing inoculum doses of a Staphylococcus chromogenes strain originating from a chronic bovine intramammary infection to a sham-inoculated mammary glands (negative control). In contrast to the high bacterial growth following inoculation with S. aureus, S. chromogenes was retrieved in very low levels at 24 h postinduction (p.i.). In a second experiment, the inflammation inflicted by 3 CNS strains was studied in mice. The host immune response induced by the S. chromogenes intramammary strain was compared with the one induced by a Staphylococcus fleurettii strain originating from cow bedding sawdust and by a S. chromogenes strain originating from a teat apex of a heifer. As expected, at 28 and 48 h p.i., low bacterial growth and local neutrophil influx in the mammary gland were induced by all CNS strains. As hypothesized, bacterial growth p.i. was the lowest for S. fleurettii compared with that induced by the 2 S. chromogenes strains, and the overall immune response established by the 3 CNS strains was less pronounced compared with the one induced by S. aureus. Proinflammatory cytokine profiling revealed that S. aureus locally induced IL-6 and IL-1 beta but not TNF-alpha, whereas, overall, CNS-inoculated glands lacked a strong cytokine host response but also induced IL-1 beta locally. Compared with both other CNS strains, S. chromogenes from the teat apex inflicted a more variable IL-1 beta response characterized by a more intense local reaction in several mice. This pilot study suggests that an intraductal mouse model can mimic bovine CNS mastitis and has potential as a complementary in vivo tool for future CNS mastitis research. Furthermore, it indicates that epidemiologically different bovine CNS species or strains induce a differential host innate immune response in the murine mammary gland

Bacterial diversity assessment in Antarctic terrestrial and aquatic microbial mats : a comparison between bidirectional pyrosequencing and cultivation

The application of high-throughput sequencing of the 16S rRNA gene has increased the size of microbial diversity datasets by several orders of magnitude, providing improved access to the rare biosphere compared with cultivation-based approaches and more established cultivation-independent techniques. By contrast, cultivation-based approaches allow the retrieval of both common and uncommon bacteria that can grow in the conditions used and provide access to strains for biotechnological applications. We performed bidirectional pyrosequencing of the bacterial 16S rRNA gene diversity in two terrestrial and seven aquatic Antarctic microbial mat samples previously studied by heterotrophic cultivation. While, not unexpectedly, 77.5% of genera recovered by pyrosequencing were not among the isolates, 25.6% of the genera picked up by cultivation were not detected by pyrosequencing. To allow comparison between both techniques, we focused on the five phyla (Proteobacteria, Actinobacteria, Bacteroidetes, Firmicutes and Deinococcus-Thermus) recovered by heterotrophic cultivation. Four of these phyla were among the most abundantly recovered by pyrosequencing. Strikingly, there was relatively little overlap between cultivation and the forward and reverse pyrosequencing-based datasets at the genus (17.1–22.2%) and OTU (3.5–3.6%) level (defined on a 97% similarity cut-off level). Comparison of the V1–V2 and V3–V2 datasets of the 16S rRNA gene revealed remarkable differences in number of OTUs and genera recovered. The forward dataset missed 33% of the genera from the reverse dataset despite comprising 50% more OTUs, while the reverse dataset did not contain 40% of the genera of the forward dataset. Similar observations were evident when comparing the forward and reverse cultivation datasets. Our results indicate that the region under consideration can have a large impact on perceived diversity, and should be considered when comparing different datasets. Finally, a high number of OTUs could not be classified using the RDP reference database, suggesting the presence of a large amount of novel diversity

Comparative accuracy and precision of two commercial laboratory analyzers for the quantification of ammonia in cerebrospinal fluid

Background: Hyperammonemia is one of the contributing factors of hepatic encephalopathy (HE). Although blood ammonia concentrations are frequently measured in patients suspected of HE, systemic levels do not necessarily reflect the amount of ammonia in the central nervous system. Measuring ammonia in cerebrospinal fluid (CSF) can help to understand HE better and potentially improve the diagnosis and follow-up of patients with HE. Objectives: The objectives of this technical report were to evaluate the accuracy and precision of two commercial blood ammonia analyzers (Catalyst Dx, CatDX and Pocket Chem BA, PocBA) to measure CSF ammonia concentrations. Methods: A pool of normal equine CSF was spiked with concentrated ammonia, and a series of six spiked samples were measured in parallel with both CatDx and PocBA. Results CatDx and PocBA data correlated excellently with but differed significantly from the spiked ammonia concentrations. These differences were smaller when ammonia CSF concentrations were measured with the PocBA than with the CatDx. In addition, values obtained with the PocBA were more precise than those measured with the CatDx, especially for low ammonia concentrations. Conclusion: This in-house comparative study shows that ammonia concentrations in spiked equine CSF correlate well with those measured by two commercial blood ammonia analyzers. Nevertheless, concentrations obtained with the PocBA are more accurate and more precise than those obtained with the CatDx, making the former device the preferred choice for clinical veterinary applications

Long-term pharmacological inhibition of the activity of all nos isoforms rather than genetic knock-out of endothelial nos leads to impaired spatial learning and memory in c57bl/6 mice

Increasing epidemiological and experimental evidence points to a link between arterial stiffness and rapid cognitive decline. However, the underlying mechanism linking the two diseases is still unknown. The importance of nitric oxide synthases in both diseases is well-defined. In this study, we introduced arterial stiffness in both genetic (eNOS(−/−), endothelial nitric oxide synthase knockout) and pharmacological (N(G)-nitro-L-arginine methyl ester (L-NAME) treatment) NO dysfunction models to study their association with cognitive decline. Our findings demonstrate that the non-selective inhibition of NOS activity with L-NAME induces cardiac dysfunction, arterial stiffness, and a decline in hippocampal-dependent learning and memory. This outcome demonstrates the importance of neuronal NOS (nNOS) in both cardiovascular and neurological pathophysiology and its potential contribution in the convergence between arterial stiffness and cognitive decline

Characterization of the non-glandular gastric region microbiota in Helicobacter suis-infected versus non-infected pigs identifies a potential role for Fusobacterium gastrosuis in gastric ulceration

Helicobacter suis has been associated with development of gastric ulcers in the non-glandular part of the porcine stomach, possibly by affecting gastric acid secretion and altering the gastric microbiota. Fusobacterium gastrosuis is highly abundant in the gastric microbiota of H. suis-infected pigs and it was hypothesized that this micro-organism could play a role in the development of gastric ulceration. The aim of this study was to obtain further insights in the influence of a naturally acquired H. suis infection on the microbiota of the non-glandular part of the porcine stomach and in the pathogenic potential of F. gastrosuis. Infection with H. suis influenced the relative abundance of several taxa at phylum, family, genus and species level. H. suis-infected pigs showed a significantly higher colonization rate of F. gastrosuis in the non-glandular gastric region compared to non-infected pigs. In vitro, viable F. gastrosuis strains as well as their lysate induced death of both gastric and oesophageal epithelial cell lines. These gastric cell death inducing bacterial components were heat-labile. Genomic analysis revealed that genes are present in the F. gastrosuis genome with sequence similarity to genes described in other Fusobacterium spp. that encode factors involved in adhesion, invasion and induction of cell death as well as in immune evasion. We hypothesize that, in a gastric environment altered by H. suis, colonization and invasion of the non-glandular porcine stomach region and production of epithelial cell death inducing metabolites by F. gastrosuis, play a role in gastric ulceration

Clifford-Jacobs Forging Company v. Capital Engineering & (and) Manufacturing Co.: The Continuing Problem within U.C.C. Section 2-207, 16 J. Marshall L. Rev. 589 (1983)

status: accepte

Nanovezels voor drug delivery van slecht oplosbare medicijnen

Om een ziekte te bestrijden via orale medicatie, moet het actieve farmaceutische bestandsdeel (API) van het gebruikte medicijn oplosbaar zijn in de waterige omgeving van het menselijk lichaam. Bepaalde, dikwijls veelbelovende, API’s zijn echter slecht oplosbaar, wat vaak te wijten is aan de kristalliniteit van het API. In dit project werd de solvent elektrospintechniek aangewend om het kristallijne API in amorfe toestand te brengen als solid dispersion (SD). Uit verschillende analyses bleek dat de wateroplosbaarheid van het medicijn hierdoor drastisch verbetert. Het elektrospinproces is daardoor een potentieel veelbelovende techniek voor de verwerking van doeltreffende API’s in de farmaceutische industrie

Paternal age at birth is an important determinant of offspring telomere length

Although evidence supports the function of telomere length (TL) as a marker for biological aging, no major determinants of TL are known besides inheritance, age and gender. Here we validate and, more importantly, assess the impact of paternal age at birth as a determinant for the offspring's peripheral blood leukocyte TL within the Asklepios study population. Telomere restriction fragment length and paternal age information were available for 2433 volunteers (1176 men and 1257 women) aged similar to 35-55 years old. Paternal age at birth was positively associated with offspring TL (offspring age and gender adjusted, P < 10 (-14)). The increase in TL was estimated at 17 base pairs for each supplemental year at birth and was not statistically different between male and female offspring. The effect size of paternal age outweighed the classical TL determinant gender by a factor of 2, demonstrating the large impact. Maternal age at birth was not independently associated with offspring TL. The peculiar interaction between paternal age at birth and inheritance might explain a large part of the genetic component of TL variance on a population level. This finding also provides further proof for the theory that TL is not completely reset in the zygote. Furthermore, as paternal age is subject to demographic evolution, its association with TL might have a substantial impact on the results and comparability of TL within and between epidemiological studies. In conclusion, paternal age is an important determinant for TL, with substantial consequences for future studies