19 research outputs found
Sensation Seeking Impact on Skin Conductance Measures of Deception and Memory
We sought to determine whether sensation seeking would differentially predict measures of memory and deception (concealing information) as indexed by behavioral (response time, accuracy) and autonomic (skin conductance level) markers in a sample of college students. Participants were randomly assigned to a mock-crime group or an innocent-errand group. Both groups were trained to complete a task requiring the copying of documents from a secure location; the difference was the mock-crime group broke into the office whereas the errand group was given permission to enter the room and access the documents. After being trained to perform the crime or errand task, participants watched a video that showed a first-person account of the crime/errand. Participants in the mock-crime group were told to conceal their knowledge of the task during an examination on the next day but to be truthful otherwise. Participants in the errand group were truthful to all items during the examination. The examination involved a recognition task that included words that were (a) scenario-related, (b) personally familiar words gathered from participants\u27 responses to questions about their lives, and (c) irrelevant words not related to the scenario nor their personal lives. Response accuracy differed for the mock-crime and errand groups, but not as a function of sensation seeking. Skin conductance responses revealed that high and low sensation seeking impacted the mock-crime and errand groups differently to personally familiar and irrelevant words, but not to scenario-related words. Findings show that determining whether individuals are high or low sensation seekers prior to assessing deception may be useful for establishing criteria for detecting deception. These results also demonstrate the need to consider personality traits in both detecting deception and understanding the biological correlates of deception
Redeploying β-lactam antibiotics as a novel antivirulence strategy for the treatment of methicillin-resistant <i>Staphylococcus aureus</i> infections
Innovative approaches to the use of existing antibiotics is an important strategy in efforts to address the escalating antimicrobial resistance crisis. We report a new approach to the treatment of methicillin-resistant Staphylococcus aureus (MRSA) infections by demonstrating that oxacillin can be used to significantly attenuate the virulence of MRSA despite the pathogen being resistant to this drug. Using mechanistic in vitro assays and in vivo models of invasive pneumonia and sepsis, we show that oxacillin-treated MRSA strains are significantly attenuated in virulence. This effect is based primarily on the oxacillin-dependent repression of the accessory gene regulator quorum-sensing system and altered cell wall architecture, which in turn lead to increased susceptibility to host killing of MRSA. Our data indicate that beta-lactam antibiotics should be included in the treatment regimen as an adjunct antivirulence therapy for patients with MRSA infections. This would represent an important change to current clinical practice for treatment of MRSA infection, with the potential to significantly improve patient outcomes in a safe, cost-effective manner
Engineered liposomes sequester bacterial exotoxins and protect from severe invasive infections in mice
Gram-positive bacterial pathogens that secrete cytotoxic pore-forming toxins, such as Staphylococcus aureus and Streptococcus pneumoniae, cause a substantial burden of disease. Inspired by the principles that govern natural toxin-host interactions, we have engineered artificial liposomes that are tailored to effectively compete with host cells for toxin binding. Liposome-bound toxins are unable to lyse mammalian cells in vitro. We use these artificial liposomes as decoy targets to sequester bacterial toxins that are produced during active infection in vivo. Administration of artificial liposomes within 10 h after infection rescues mice from septicemia caused by S. aureus and S. pneumoniae, whereas untreated mice die within 24-33 h. Furthermore, liposomes protect mice against invasive pneumococcal pneumonia. Composed exclusively of naturally occurring lipids, tailored liposomes are not bactericidal and could be used therapeutically either alone or in conjunction with antibiotics to combat bacterial infections and to minimize toxin-induced tissue damage that occurs during bacterial clearance
The histology of ovarian cancer: worldwide distribution and implications for international survival comparisons (CONCORD-2)
Objective Ovarian cancers comprise several histologically distinct tumour groups with widely different prognosis. We aimed to describe the worldwide distribution of ovarian cancer histology and to understand what role this may play in international variation in survival. Methods The CONCORD programme is the largest population-based study of global trends in cancer survival. Data on 681,759 women diagnosed during 1995â\u80\u932009 with cancer of the ovary, fallopian tube, peritoneum and retroperitonum in 51 countries were included. We categorised ovarian tumours into six histological groups, and explored the worldwide distribution of histology. Results During 2005â\u80\u932009, type II epithelial tumours were the most common. The proportion was much higher in Oceania (73.1%), North America (73.0%) and Europe (72.6%) than in Central and South America (65.7%) and Asia (56.1%). By contrast, type I epithelial tumours were more common in Asia (32.5%), compared with only 19.4% in North America. From 1995 to 2009, the proportion of type II epithelial tumours increased from 68.6% to 71.1%, while the proportion of type I epithelial tumours fell from 23.8% to 21.2%. The proportions of germ cell tumours, sex cord-stromal tumours, other specific non-epithelial tumours and tumours of non-specific morphology all remained stable over time. Conclusions The distribution of ovarian cancer histology varies widely worldwide. Type I epithelial, germ cell and sex cord-stromal tumours are generally associated with higher survival than type II tumours, so the proportion of these tumours may influence survival estimates for all ovarian cancers combined. The distribution of histological groups should be considered when comparing survival between countries and regions
A non-inferiority analysis of hemoglobin levels in postpartum IUD users in Bangladesh
OBJECTIVE: The objective of this study was to compare postpartum hemoglobin (Hb) between postpartum intrauterine device (PPIUD) and non-PPIUD users. METHODS: A sample of 3697 postpartum women (475 PPIUD users, 3222 non-PPIUD users) from 5 tertiary referral hospitals in Bangladesh were assessed at multiple time points between 6Â weeks and 12Â months postpartum. Non-inferiority linear regression analysis compared changes in Hb levels at 29-52Â weeks postpartum between the two groups. Non-inferiority was declared if the lower 95% confidence interval of the estimated difference in Hb change since delivery between PPIUD and non-PPIUD users was greater than -0.05Â g/dl. RESULTS: At approximately 9Â months postpartum, 276 women in the PPIUD group (58.1%) and 1086 women in the comparison group (33.7%) attended follow-up. In total, 57.9% of PPIUD users and 61.0% of non-PPIUD users had taken iron supplementation. Change in Hb was 0.02Â g/dl (95% CI: -0.16, 0.19) higher in the PPIUD users than the comparison group. The lower limit of the 95% CI was greater than -0.05Â g/dl, providing good evidence that PPIUD users were non-inferior to the comparison group in their Hb levels. CONCLUSION: In the presence of offering iron supplementation, and an uptake of just over 60%, no difference in anemia was observed between the PPIUD and control group
P4-mediated antibody therapy in an acute model of invasive pneumococcal disease
New treatments against severe bacterial infections are needed because the response to antibiotic treatment is slow in acute settings and is becoming less effective owing to the emergence of antibiotic-resistant pathogens. P4-mediated antibody therapy offers a unique treatment strategy that combines exogenous immunoglobulin with the immunoactivating peptide P4. In an acute model of pneumococcal disease, mice were infected with Streptococcus pneumoniae and treated intravenously or intranasally with P4 and intravenous immunoglobulin (IVIG). Survival of P4-IVIG-treated mice increased from 0% to 60% among those that received intravenous treatment and from 0% to 100% among those that received intranasal treatment. Importantly, intranasal administration of P4 at an early stage of infection prevented the onset of bacteremia and sepsis. Increased survival was associated with reduced bacterial burden in affected tissues and with recruitment and activation of professional phagocytes, as manifested by increased expression of Fc-γ receptors. In vitro studies involving P4-stimulated alveolar, peritoneal, and J774.2 murine macrophages showed an increased ability of these immune cells to phagocytose pneumococci independent of capsule. The use of adjunct antibody therapies to treat infectious diseases shows promise
Redeploying β-lactam antibiotics as a novel antivirulence strategy for the treatment of methicillin-resistantstaphylococcus aureusinfections
Innovative approaches to the use of existing antibiotics is an important strategy in efforts to address the escalating antimicrobial resistance crisis. We report a new approach to the treatment of methicillin-resistant Staphylococcus aureus (MRSA) infections by demonstrating that oxacillin can be used to significantly attenuate the virulence of MRSA despite the pathogen being resistant to this drug. Using mechanistic in vitro assays and in vivo models of invasive pneumonia and sepsis, we show that oxacillin-treated MRSA strains are significantly attenuated in virulence. This effect is based primarily on the oxacillin-dependent repression of the accessory gene regulator quorum-sensing system and altered cell wall architecture, which in turn lead to increased susceptibility to host killing of MRSA. Our data indicate that beta-lactam antibiotics should be included in the treatment regimen as an adjunct antivirulence therapy for patients with MRSA infections. This would represent an important change to current clinical practice for treatment of MRSA infection, with the potential to significantly improve patient outcomes in a safe, cost-effective manner
Synthesis of different magnetic carbon nanostructures by the pyrolysis of ferrocene at different sublimation temperatures
Various magnetic nanostructures such as Fe nanoparticles (Fe-NPs) adhering to single-walled carbon nanotubes, carbon-encapsulated Fe-NPs, Fe-NP decorated multi-walled carbon nanotubes (MWCNTs), and Fe-filled MWCNTs have been synthesized by the pyrolysis of pure ferrocene. It is found that the formation of the nanostructures can be selectively controlled by simply adjusting the sublimation temperature of ferrocene, while keeping all other experimental parameters unchanged. Magnetic characterization reveals that these nanostructures have an enhanced coercivity, higher than that of bulk Fe at room temperature. Based on the experimental results, the formation mechanism of the nanostructures is discussed in detail
Redeploying β-Lactam Antibiotics as a Novel Antivirulence Strategy for the Treatment of Methicillin-Resistant Staphylococcus aureus
Relationship between capsule type and carriage efficiency in a mouse model.
<p>Ability of wildtype strains and mutants to colonize the nasopharynx of female MF1 mice was determined by quantification of colony forming units (CFU) per mg nasopharyngeal tissue on the day of inoculation and 1 and 7 days later. By day 7, the disadvantage of a 7F capsule, but not a 6B capsule, in colonization was apparent. Error bars represent one standard error.</p