127 research outputs found
Description, Host-specificity, and Strain Selectivity of the Dinoflagellate Parasite Parvilucifera sinerae sp.nov. (Perkinsozoa)
17 pages, 7 figures, 2 tablesA new species of parasite, Parvilucifera sinerae sp. nov., isolated froma bloomof the toxic Dinoflagellate Alexandrium minutum in the harbor of Arenys de Mar (Mediterranean Sea, Spain), is described. This species is morphologically, behaviourally, and genetically (18S rDNA sequence) different from Parvilucifera infectans, until now the only species of the genus Parvilucifera to be genetically analyzed. Sequence análisis of the 18S ribosomal DNA supported P. Sinerae as a new species placed within the Perkinsozoa and close to P. infectans. Data on the seasonal occurrence of P. sinerae, its infective rates in natural and laboratory cultures, and intra-species strain-specific Resistance are presented. Life-cycle studies in field simples showed that the dinoflagellate resting zygote (restingcyst) was resistant to infection, but the mobile zygote (planozygote) orpelli clestage (temporary cyst) became infected. The effects of Light and salinity level son the growth of P. sinerae were examined, and the results showed that low salinity levels promote both sporangial germination and higher rates of infection. Our findings on this newly described parasite point to a complex host—parasite interaction and provide valuable information that leads to a reconsideration of the biological strategy to control dinoflagellate blooms by jeans of intentional parasitic infectionsThis research was funded by the EU Project SEED (GOCE-CT-2005-003875). R.I. Figueroa work is supported by a I3P contract and E. Garcés’ work is supported by a Ramon y Cajal grant, both from the Spanish Ministry of Education and SciencePeer reviewe
Intraoperative magnetic resonance imaging versus standard neuronavigation for the neurosurgical treatment of glioblastoma: A randomized controlled trial.
BACKGROUND: Although the added value of increasing extent of glioblastoma resection
is still debated, multiple technologies can assist neurosurgeons in attempting to
achieve this goal. Intraoperative magnetic resonance imaging (iMRI) might be helpful
in this context, but to date only one randomized trial exists. METHODS: We included
14 adults with a supratentorial tumor suspect for glioblastoma and an indication for
gross total resection in this randomized controlled trial of which the interim
analysis is presented here. Participants were assigned to either ultra-low-field
strength iMRI-guided surgery (0.15 Tesla) or to conventional neuronavigation-guided
surgery (cNN). Primary endpoint was residual tumor volume (RTV) percentage.
Secondary endpoints were clinical performance, health-related quality of life
(HRQOL) and survival. RESULTS: Median RTV in the cNN group is 6.5% with an
interquartile range of 2.5-14.75%. Median RTV in the iMRI group is 13% with an
interquartile range of 3.75-27.75%. A Mann-Whitney test showed no statistically
significant difference between these groups (P =0.28). Median survival in the cNN
group is 472 days, with an interquartile range of 244-619 days. Median survival in
the iMRI group is 396 days, with an interquartile range of 191-599 days (P =0.81).
Clinical performance did not differ either. For HRQOL only descriptive statistics
were applied due to a limited sample size. CONCLUSION: This interim analysis of a
randomized trial on iMRI-guided glioblastoma resection compared with cNN-guided
glioblastoma resection does not show an advantage with respect to extent of
resection, clinical performance, and survival for the iMRI group. Ultra-low-field
strength iMRI does not seem to be cost-effective compared with cNN, although the
lack of a valid endpoint for neurosurgical studies evaluating extent of glioblastoma
resection is a limitation of our study and previous volumetry-based studies on this
topic.Peer reviewe
Patient Preferences in the Medical Product Life Cycle: What do Stakeholders Think? Semi-Structured Qualitative Interviews in Europe and the USA.
Background Patient preferences (PP), which are investigated in PP studies using qualitative or quantitative methods, are a
growing area of interest to the following stakeholders involved in the medical product lifecycle: academics, health technology assessment bodies,
Are the distributions of variations of circle of Willis different in different populations? – Results of an anatomical study and review of literature
BACKGROUND: Previous studies have proposed correlation between variants of the cerebral arterial circle (also known as circle of Willis) and some cerebrovascular diseases. Differences in the incidence of these diseases in different populations have also been investigated. The study of variations in the anatomy of the cerebral arterial circle may partially explain differences in the incidence of some of the cerebrovascular diseases in different ethnic or racial groups. While many studies have investigated the variations in the anatomy of each segment of the cerebral arterial circle, few have addressed the variants of the cerebral arterial circle as a whole. Similarly, the frequency of occurrence of such variants in different ethnic or racial groups has not been compared. METHODS: 102 brains of recently deceased Iranian males were dissected, in order to observe variations in the anatomy of the cerebral arterial circle. The dissection process was recorded on film and digitized. One resized picture from each dissection, showing complete circle has been made available online. The variations of the circle as whole and segmental variations were compared with previous studies. RESULTS: On the whole, the frequencies of the different variants of the entire cerebral arterial circle and segmental variations were comparable with previous studies. More specifically variants with uni- and bilateral hypoplasia of posterior communicating arteries were the most common in our study, similar to the previous works. No hypoplasia of the precommunicating part of the left anterior cerebral artery (A1), aplasia of A1 or the precommunicating part of the posterior cerebral artery (P1) was seen. In 3% both right and left posterior communcating arteries were absent. CONCLUSION: The anatomical variations found in the cerebral arterial circle of the Iranian males in the current study were not significantly different to those of more diverse populations reported in the literature. While taking into account potential confounding factors, the authors conclude that based on available studies, there is no evidence suggesting that the distributions of the variations of cerebral arterial circle differ in different populations
Breast MRI in nonpalpable breast lesions: a randomized trial with diagnostic and therapeutic outcome – MONET – study
<p>Abstract</p> <p>Background</p> <p>In recent years there has been an increasing interest in MRI as a non-invasive diagnostic modality for the work-up of suspicious breast lesions. The additional value of Breast MRI lies mainly in its capacity to detect multicentric and multifocal disease, to detect invasive components in ductal carcinoma in situ lesions and to depict the tumor in a 3-dimensional image. Breast MRI therefore has the potential to improve the diagnosis and provide better preoperative staging and possibly surgical care in patients with breast cancer. The aim of our study is to assess whether performing contrast enhanced Breast MRI can reduce the number of surgical procedures due to better preoperative staging and whether a subgroup of women with suspicious nonpalpable breast lesions can be identified in which the combination of mammography, ultrasound and state-of-the-art contrast-enhanced Breast MRI can provide a definite diagnosis.</p> <p>Methods/Design</p> <p>The MONET – study (<b><it>M</it></b>R mammography <b><it>O</it></b>f <b><it>N</it></b>onpalpable Br<b><it>E</it></b>ast <b><it>T</it></b>umors) is a randomized controlled trial with diagnostic and therapeutic endpoints. We aim to include 500 patients with nonpalpable suspicious breast lesions who are referred for biopsy. With this number of patients, the expected 12% reduction in surgical procedures due to more accurate preoperative staging with Breast MRI can be detected with a high power (90%). The secondary outcome is the positive and negative predictive value of contrast enhanced Breast MRI. If the predictive values are deemed sufficiently close to those for large core biopsy then the latter, invasive, procedure could possibly be avoided in some women. The rationale, study design and the baseline characteristics of the first 100 included patients are described.</p> <p>Trial registration</p> <p>Study protocol number NCT00302120</p
Design, Conduct and Use of Patient Preference Studies in the Medical Product Life Cycle
Objectives: To investigate stakeholder perspectives on how patient preference studies
(PPS) should be designed and conducted to allow for inclusion of patient preferences in
decision-making along the medical product life cycle (MPLC), and how patient preferences
can be used in such decision-making.
Methods: Two literature reviews and semi-structured interviews (n = 143) with healthcare
stakeholders in Europe and the US were conducted; results of these informed the design
of focus group guides. Eight focus groups were conducted with European patients,
industry representatives and regulators, and with US regulators and European/Canadian
health technology assessment (HTA) representatives. Focus groups were analyzed
thematically using NVivo.
Results: Stakeholder perspectives on how PPS should be designed and conducted
were as follows: 1) study design should be informed by the research questions and patient
population; 2) preferred treatment attributes and levels, as well as trade-offs among
attributes and levels should be investigated; 3) the patient sample and method should
match the MPLC phase; 4) different stakeholders should collaborate; and 5) results from
PPS should be shared with relevant stakeholders. The value of patient preferences in
decision-making was found to increase with the level of patient preference sensitivity of
decisions on medical products. Stakeholders mentioned that patient preferences are hardly
used in current decision-making. Potential applications for patient preferences across
industry, regulatory and HTA processes were identified. Four applications seemed most
promising for systematic integration of patient preferences: 1) benefit-risk assessment
by industry and regulators at the marketing-authorization phase; 2) assessment of major contribution to patient care by European regulators; 3) cost-effectiveness analysis; and 4)
multi criteria decision analysis in HTA.
Conclusions: The value of patient preferences for decision-making depends on the level
of collaboration across stakeholders; the match between the research question, MPLC
phase, sample, and preference method used in PPS; and the sen
Role of TNFα in pulmonary pathophysiology
Tumor necrosis factor alpha (TNFα) is the most widely studied pleiotropic cytokine of the TNF superfamily. In pathophysiological conditions, generation of TNFα at high levels leads to the development of inflammatory responses that are hallmarks of many diseases. Of the various pulmonary diseases, TNFα is implicated in asthma, chronic bronchitis (CB), chronic obstructive pulmonary disease (COPD), acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). In addition to its underlying role in the inflammatory events, there is increasing evidence for involvement of TNFα in the cytotoxicity. Thus, pharmacological agents that can either suppress the production of TNFα or block its biological actions may have potential therapeutic value against a wide variety of diseases. Despite some immunological side effects, anti-TNFα therapeutic strategies represent an important breakthrough in the treatment of inflammatory diseases and may have a role in pulmonary diseases characterized by inflammation and cell death
Prevalence of Trypanosoma cruzi antibodies and inflammatory markers in uncompensated heart failure
A holistic framework of corporate website favourability
This paper extends the current knowledge of corporate website favourability (CWF) by developing a comprehensive conceptual model of its influence on corporate image, corporate reputation, loyalty and identification. The paper reviews previous studies on corporate websites from the perspectives of marketing, management, corporate identity and corporate visual identity in order to inform our understanding of the antecedents and consequences of CWF. The propositions and the conceptual framework present an approach by which a corporation can design and manage a favourable corporate website. A number of important contributions are offered: First, the paper adds to the understanding of CWF; second, it discusses the antecedents of CWF by drawing upon the existing literature; third, it is beneficial for practitioners in shaping CWF strategies, and fourth, it offers possible consequences of CWF and provides a framework for future testing
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