521 research outputs found
Role of glucose and CcpA in capsule expression and virulence of Streptococcus suis
Streptococcus suis is one of the most important pathogens in pigs and is also an emerging zoonotic agent. After crossing the epithelial barrier, S. suis causes bacteraemia, resulting in meningitis, endocarditis and bronchopneumonia. Since the host environment seems to be an important regulatory component for virulence, we related expression of virulence determinants of S. suis to glucose availability during growth and to the sugar metabolism regulator catabolite control protein A (CcpA). We found that expression of the virulence-associated genes arcB, representing arcABC operon expression, cps2A, representing capsular locus expression, as well as sly, ofs, sao and epf, differed significantly between exponential and early stationary growth of a highly virulent serotype 2 strain. Deletion of ccpA altered the expression of the surface-associated virulence factors arcB, sao and eno, as well as the two currently proven virulence factors in pigs, ofs and cps2A, in early exponential growth. Global expression analysis using a cDNA expression array revealed 259 differentially expressed genes in early exponential growth, of which 141 were more highly expressed in the CcpA mutant strain 10¿ccpA and 118 were expressed to a lower extent. Interestingly, among the latter genes, 18 could be related to capsule and cell wall synthesis. Correspondingly, electron microscopy characterization of strain 10¿ccpA revealed a markedly reduced thickness of the capsule. This phenotype correlated with enhanced binding to porcine plasma proteins and a reduced resistance to killing by porcine neutrophils. Taken together, our data demonstrate that CcpA has a significant effect on the capsule synthesis and virulence properties of S. suis
Calcium and magnesium in human toenails do not reflect bone mineral density
Nail mineral composition is influenced by several physiological and pathological processes. Potentially, nails could be used to monitor alterations in the level of incorporation of specific elements produced by nutritional abnormalities, disease states or chronic exposure to toxic agents. The purpose of this study was to investigate whether the calcium and magnesium content in nail clippings, as measured by instrumental neutron activation analysis (INAA), correlates with bone mineral density (BMD), as measured by quantitative microdensitometry (QMD), and therefore could be interesting as a screening instrument for osteoporosis. The study involved 220 women, who participated in a breast cancer screening project (the DOM-project) in Utrecht, the Netherlands. The correlations found between Ca and Mg measurements and bone mineral densities were very low (correlation coefficients ranging from 0.03 to 0.18). It is concluded that Ca and Mg measurements in nail clippings by INAA cannot be used for screening purposes in the prevention of osteoporosis
Surgeons produce innovative ideas which are frequently lost in the labyrinth of patents
Thoracic and cardiovascular surgery are innovative specialties that regularly recruit the latest technological developments into their armoury of devices and equipment. The introduction of new technology is dependant on patents; an important but single component of intellectual property. Patents enable the attribution of rights to concepts, ideas and inventions and this facilitates ownership, subsequent licensing and overall management of innovation and its outcome. It is not just thoracic and cardiovascular surgery, but the healthcare world in general that experiences ongoing technological evolution; so to remain contemporary, it is important that those in positions of responsibility are familiar with the relevant processes. This requires basic medico-legal knowledge and may be entwined with significant financial responsibility. Penetrating clinical, academic and industrial environments, informed awareness of patents also contributes to important leadership skills, encouraging the incorporation of innovation into the professional milieu. We aim to present through this manuscript an overview of these issues in order to promote awareness of patents within thoracic and cardiovascular surgery using a descriptive and practical approac
Translation to success of surgical innovation
Contemporary thoracic and cardiovascular surgery uses extensive equipment and devices to enable its performance. As the specialties develop and new frontiers are crossed, the technology needs to advance in a parallel fashion. Strokes of genius or problem-solving brain-storming may generate great ideas, but the metamorphosis of an idea into a physical functioning tool requires a lot more than just a thinking process. A modern surgical device is the end-point of a sophisticated, complicated and potentially treacherous route, which incorporates new skills and knowledge acquisition. Processes including technology transfer, commercialisation, corporate and product development, intellectual property and regulatory routes all play pivotal roles in this voyage. Many good ideas may fall by the wayside for a multitude of reasons as they may not be marketable or may be badly marketed. In this article, we attempt to illuminate the components required in the process of surgical innovation, which we believe must remain in the remit of the modern-day thoracic and cardiovascular surgeo
The course of neuropathy after cessation of cisplatin treatment, combined with Org 2766 or placebo
Peripheral neuropathy is an important and disabling side-effect of cisplatin treatment. A new drug, Org 2766, has been found to prevent this neuropathy up to 1 month after treatment. A group of 18 patients with ovarian cancer, who participated in an earlier randomized study with placebo or Org 2766, together with cisplatin and cyclophophamide, were thereafter prospectively followed up to 2 years after discontinuation of treatment to monitor the development of neurological signs and symptoms and vibration perception threshold (VPT). Exploratory, descriptive data analysis shows that between 1 and 4 months after the last cycle the average sum score for neurological signs and symptoms and VPT had deteriorated compared with 1 month after treatment. Thereafter a gradual but incomplete improvement was seen between 4-12 and 12-24 months after treatment. These changes were seen in all patients regardless of previous treatment with Org 2766 or placebo, but deterioration was less pronounced in patients previously treated with Org 2766. These results suggests that treatment with Org 2766 to prevent a cisplatin-induced neuropathy should possibly be continued up to 4 months after the last cycle of cisplatin
How to manage the left subclavian artery during endovascular stenting of the thoracic aorta
We performed a systematic review of the literature to establish whether revascularisation of the left subclavian territory is necessary when this artery is covered by a stent. We retrieved data from 99 studies incorporating 4906 patients. Incidences of left-arm ischaemia (0.0% vs 9.2%, p=0.002) and stroke (4.7% vs 7.2%, p≪0.001) were significantly less following revascularisation, although mortality (10.5% vs 3.4%, p=0.032) and endoleak incidence (25.8% vs 12.6%, p=0.008) were increased. No significant differences in spinal-cord ischaemia were seen. Revascularisation may reduce downstream ischaemic complications but can cause significant risk. Indications must be carefully considered on an individual patient basi
A naturally occurring nucleotide polymorphism in the orf2/folc promoter is associated with Streptococcus suis virulence
Surgeons produce innovative ideas which are frequently lost in the labyrinth of patents
Thoracic and cardiovascular surgery are innovative specialties that regularly recruit the latest technological developments into their armoury of devices and equipment. The introduction of new technology is dependant on patents; an important but single component of intellectual property. Patents enable the attribution of rights to concepts, ideas and inventions and this facilitates ownership, subsequent licensing and overall management of innovation and its outcome. It is not just thoracic and cardiovascular surgery, but the healthcare world in general that experiences ongoing technological evolution; so to remain contemporary, it is important that those in positions of responsibility are familiar with the relevant processes. This requires basic medico-legal knowledge and may be entwined with significant financial responsibility. Penetrating clinical, academic and industrial environments, informed awareness of patents also contributes to important leadership skills, encouraging the incorporation of innovation into the professional milieu. We aim to present through this manuscript an overview of these issues in order to promote awareness of patents within thoracic and cardiovascular surgery using a descriptive and practical approach
Sphecidae (Hymenoptera: Apoidea) of Rio de Janeiro State (Southeast Brazil): new geographic records and remarks on faunal distribution
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