426 resultados para infection risk


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Purpose: Colorectal cancer patients diagnosed with stage I or II disease are not routinely offered adjuvant chemotherapy following resection of the primary tumor. However, up to 10% of stage I and 30% of stage II patients relapse within 5 years of surgery from recurrent or metastatic disease. The aim of this study was to determine if tumor-associated markers could detect disseminated malignant cells and so identify a subgroup of patients with early-stage colorectal cancer that were at risk of relapse. Experimental Design: We recruited consecutive patients undergoing curative resection for early-stage colorectal cancer. Immunobead reverse transcription-PCR of five tumor-associated markers (carcinoembryonic antigen, laminin γ2, ephrin B4, matrilysin, and cytokeratin 20) was used to detect the presence of colon tumor cells in peripheral blood and within the peritoneal cavity of colon cancer patients perioperatively. Clinicopathologic variables were tested for their effect on survival outcomes in univariate analyses using the Kaplan-Meier method. A multivariate Cox proportional hazards regression analysis was done to determine whether detection of tumor cells was an independent prognostic marker for disease relapse. Results: Overall, 41 of 125 (32.8%) early-stage patients were positive for disseminated tumor cells. Patients who were marker positive for disseminated cells in post-resection lavage samples showed a significantly poorer prognosis (hazard ratio, 6.2; 95% confidence interval, 1.9-19.6; P = 0.002), and this was independent of other risk factors. Conclusion: The markers used in this study identified a subgroup of early-stage patients at increased risk of relapse post-resection for primary colorectal cancer. This method may be considered as a new diagnostic tool to improve the staging and management of colorectal cancer. © 2006 American Association for Cancer Research.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The multiple banded antigen (MBA) is a predicted virulence factor of Ureaplasma species. Antigenic variation of the MBA is a potential mechanism by which ureaplasmas avoid immune recognition and cause chronic infections of the upper genital tract of pregnant women. We tested whether the MBA is involved in the pathogenesis of intra-amniotic infection and chorioamnionitis by injecting virulent or avirulent-derived ureaplasma clones (expressing single MBA variants) into the amniotic fluid of pregnant sheep. At 55 days of gestation pregnant ewes (n = 20) received intra-amniotic injections of virulent-derived or avirulent-derived U. parvum serovar 6 strains (2×104 CFU), or 10B medium (n = 5). Amniotic fluid was collected every two weeks post-infection and fetal tissues were collected at the time of surgical delivery of the fetus (140 days of gestation). Whilst chronic colonisation was established in the amniotic fluid of animals infected with avirulent-derived and virulent-derived ureaplasmas, the severity of chorioamnionitis and fetal inflammation was not different between these groups (p>0.05). MBA size variants (32–170 kDa) were generated in vivo in amniotic fluid samples from both the avirulent and virulent groups, whereas in vitro antibody selection experiments led to the emergence of MBA-negative escape variants in both strains. Anti-ureaplasma IgG antibodies were detected in the maternal serum of animals from the avirulent (40%) and virulent (55%) groups, and these antibodies correlated with increased IL-1β, IL-6 and IL-8 expression in chorioamnion tissue (p<0.05). We demonstrate that ureaplasmas are capable of MBA phase variation in vitro; however, ureaplasmas undergo MBA size variation in vivo, to potentially prevent eradication by the immune response. Size variation of the MBA did not correlate with the severity of chorioamnionitis. Nonetheless, the correlation between a maternal humoral response and the expression of chorioamnion cytokines is a novel finding. This host response may be important in the pathogenesis of inflammation-mediated adverse pregnancy outcomes.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Objective: To comprehensively measure the burden of hepatitis B, liver cirrhosis and liver cancer in Shandong province, using disability-adjusted life years (DALYs) to estimate the disease burden attribute to hepatitis B virus (HBV)infection. Methods: Based on the mortality data of hepatitis B, liver cirrhosis and liver cancer derived from the third National Sampling Retrospective Survey for Causes of Death during 2004 and 2005, the incidence data of hepatitis B and the prevalence and the disability weights of liver cancer gained from the Shandong Cancer Prevalence Sampling Survey in 2007, we calculated the years of life lost (YLLs), years lived with disability (YLDs) and DALYs of three diseases following the procedures developed for the global burden of disease (GBD) study to ensure the comparability. Results: The total burden for hepatitis B, liver cirrhosis and liver cancer were 211 616 (39 377 YLLs and 172 239 YLDs), 16 783 (13 497 YLLs and 3286 YLDs) and 247 795 (240 236 YLLs and 7559 YLDs) DALYs in 2005 respectively, and men were 2.19, 2.36 and 3.16 times as that for women, respectively in Shandong province. The burden for hepatitis B was mainly because of disability (81.39%). However, most burden on liver cirrhosis and liver cancer were due to premature death (80.42% and 96.95%). The burden of each patient related to hepatitis B, liver cirrhosis and liver cancer were 4.8, 13.73 and 11.11 respectively. Conclusion: Hepatitis B, liver cirrhosis and liver cancer caused considerable burden to the people living in Shandong province, indicating that the control of hepatitis B virus infection would bring huge potential benefits.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Objective: To determine the major health related risk factors and provide evidence for policy-making,using health burden analysis on selected factors among general population from Shandong province. Methods: Based on data derived from the Third Death of Cause Sampling Survey in Shandong. Years of life lcrat(YLLs),yearS Iived with disability(YLDs)and disability-adjusted life years(DALYs) were calculated according to the GBD ethodology.Deaths and DALYs attributed to the selected risk factors were than estimated together with the PAF data from GBD 2001 study.The indirect method was employed to estimate the YLDs. Results: 51.09%of the total dearlls and 31.83%of the total DALYs from the Shandong population were resulted from the 19 selected risk factors.High blood pre.ure,smoking,low fruit and vegetable intake,aleohol consumption,indoor smoke from solid fuels,high cholesterol,urban air pollution, physical inactivity,overweight and obesity and unsafe injections in health care settings were identified as the top 10 risk faetors for mortality which together caused 50.21%of the total deaths.Alcohol use,smoking,high blood pressure,Low fruit and vegetable intake, indoor smoke from solid fuels, overweight and obesity,high cholesterol, physical inactivity,urban air pollution and iron-deficiency anemia were proved as the top 10 risk factors related to disease burden and were responsible for 29.04%of the total DALYs. Conclusion: Alcohol use.smoking and high blood pressure were determined as the major risk factors which influencing the health of residents in Shandong. The mortality and burden of disease could be reduced significantly if these major factors were effectively under control.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The focus of governments on increasing active travel has motivated renewed interest in cycling safety. Bicyclists are up to 20 times more likely to be involved in serious injury crashes than drivers so understanding the relationship among factors in bicyclist crash risk is critically important for identifying effective policy tools, for informing bicycle infrastructure investments, and for identifying high risk bicycling contexts. This study aims to better understand the complex relationships between bicyclist self reported injuries resulting from crashes (e.g. hitting a car) and non-crashes (e.g. spraining an ankle) and perceived risk of cycling as a function of cyclist exposure, rider conspicuity, riding environment, rider risk aversion, and rider ability. Self reported data from 2,500 Queensland cyclists are used to estimate a series of seemingly unrelated regressions to examine the relationships among factors. The major findings suggest that perceived risk does not appear to influence injury rates, nor do injury rates influence perceived risks of cycling. Riders who perceive cycling as risky tend not to be commuters, do not engage in group riding, tend to always wear mandatory helmets and front lights, and lower their perception of risk by increasing days per week of riding and by increasing riding proportion on bicycle paths. Riders who always wear helmets have lower crash injury risk. Increasing the number of days per week riding tends to decrease both crash injury and non crash injury risk (e.g. a sprain). Further work is needed to replicate some of the findings in this study.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Purpose: The purpose of this study is to investigate Latin American online purchase behaviour with a specific focus on the influence of perceived risk and trust. While studies of this nature have been conducted quite extensively in developed countries, their application in developing countries, such as Latin America is limited. Our study addresses this gap in the literature with an empirical study conducted in Chile. Design/methodology/approach: The authors develop and test a proposed model of the influence of consumer’s perceptions of risk and trust on their attitudes and intentions to purchase on the Internet. An online survey method is used. The sample consists of 176 Chilean consumers who have made at least one purchase online. The data is analysed using structural equation modelling technique (SEM). Findings: The analysis revealed that of the perceived risk and trust factors examined, trust in third party assurances and a cultural environment of trust had the strongest positive influence on intentions to continuing purchasing online. Perceived risk had an inverse relationship with attitude and consumers’ attitude has a positive influence on intentions to purchase online. Trust in online vendors and a propensity to trust were both insignificant. Practical implications: Practically, these results identity which risk and trust beliefs towards purchasing online have the most effect thereby providing insights into how companies should seek to mitigate perceptions of risk to encourage new and return purchasers. Additionally, this research shows that consumers in a Latin American country, recognised as a collectivist, high risk avoidance culture, are willing to make purchases online despite the risks involved. Originality/value: The study and its results is one of few available that consider a Latin American context. The value of the findings provides insights into the specific risk and trust factors that influence Chilean consumers when considering purchasing online. The tested model adds value not only to the literature on Latin American consumer behaviour but also provides guidance for companies offering online retailing facilities in these less developed countries.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

ABSRACT. Despite the surge in online retail sales in recent years there still remains reluctance by consumers to complete the online shopping process. A number of authors have attributed consumers’ reluctance to purchase online to apparent barriers. However, such barriers as yet have not been fully examined within a theoretical context. This research explores the application of the perceived risk theoretical framework. Specifically, performance risk and the influence of perceived performance risk has on the phenomenon of Internet Abandoned Cart Syndrome (ACS) is evaluated. To explore this phenomenon, a number of extrinsic cues are identified as playing a major role in the performance evaluation process of online purchases. The results of this study suggest the extrinsic cues of brand, reputation, design and price have an overall impact on the performance evaluation process just prior to an online purchase. Varying these cues either positively or negatively had a strong impact on performance evaluation. Further, it was found that positive or negative reputation was heavily associated with shopping cart abandonment.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Objectives: To investigate if low-dose lithium may counteract the microstructural and metabolic brain changes proposed to occur in individuals at ultra-high risk (UHR) for psychosis. Methods: Hippocampal T2 relaxation time (HT2RT) and proton magnetic resonance spectroscopy (1H-MRS) measurements were performed prior to initiation and following three months of treatment in 11 UHR patients receiving low-dose lithium and 10 UHR patients receiving treatment as usual (TAU). HT2RT and 1H-MRS percentage change scores between scans were compared using one-way ANOVA and correlated with behavioural change scores. Results: Low-dose lithium significantly reduced HT2RT compared to TAU (p=0.018). No significant group by time effects were seen for any brain metabolites as measured with 1H-MRS, although myo-inositol, creatine, choline-containing compounds and NAA increased in the group receiving low-dose lithium and decreased or remained unchanged in subjects receiving TAU. Conclusions: This pilot study suggests that low-dose lithium may protect the microstructure of the hippocampus in UHR states as reflected by significantly decreasing HT2RT. Larger scale replication studies in UHR states using T2 relaxation time as a proxy for emerging brain pathology seem a feasible mean to test neuroprotective strategies such as low-dose lithium as potential treatments to delay or even prevent the progression to full-blown disorder.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In this paper I consider a role for risk understanding in school science education. Grounds for this are described in terms of current sociological analyses of the contemporary world as a ‘risk society’ and recent public understanding of science studies where science and risk are concerns commonly linked within the wider community. These concerns connect with support amongst many science educators for the goal of science education for citizenship. From this perspective scientific literacy for decision making on contemporary socioscientific issues is central. I argue that in such decision making risk understanding has an important role to play. I examine some of the challenges its inclusion in school science presents to science teachers, review previous writing about risk in the science education literature and consider how knowledge about risk might be addressed in school science. I also outline the varying conceptions of risk and suggest some future research directions which would support the inclusion of risk in classroom discussions of socioscientific issues.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Recent years have seen a rapid increase in SMEs working collaboratively in inter-organizational projects. But what drives the emergence of such projects, and what types of industries breed them the most? To address these questions, this paper extends the long running literature on the firm and industry antecedents of new venturing and alliance formation to the domain of project-based organization by SMEs. Based on survey data collected among 1,725 small and medium sized organizations and longitudinal industry data, we find an overall pattern that indicates that IOPV participation is primarily determined by a focal SME’s scope of innovative activities, and the munificence, dynamism and complexity of its environment. Unexpectedly, these variables have different effects on whether SMEs are likely to engage in IOPVs, compared to with how many there are in their portfolio at a time. Implications for theory development are discussed.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Chlamydia trachomatis is the most prevalent bacterial sexually transmitted infection in the developed world and the leading cause of preventable blindness worldwide. As reported by the World Health Organization in 2001, there are approximately 92 million new infections detected annually, costing health systems billions of dollars to treat not only the acute infection, but also to treat infection-associated sequelae. The majority of genital infections are asymptomatic, with 50-70% going undetected. Genital tract infections can be easily treated with antibiotics when detected. Lack of treatment can lead to the development of pelvic inflammatory disease, ectopic pregnancies and tubal factor infertility in women and epididymitis and prostatitis in men. With infection rates on the continual rise and the large number of infections going undetected, there is a need to develop an efficacious vaccine which prevents not only infection, but also the development of infection-associated pathology. Before a vaccine can be developed and administered, the pathogenesis of chlamydial infections needs to be fully understood. This includes the kinetics of ascending infection and the effects of inoculating dose on ascension and development of pathology. The first aim in this study was to examine these factors in a murine model. Female BALB/c mice were infected intravaginally with varying doses of C. muridarum, the mouse variant of human C. trachomatis, and the ascension of infection along the reproductive tract and the time-course of infection-associated pathology development, including inflammatory cell infiltration, pyosalpinx and hydrosalpinx, were determined. It was found that while the inoculating dose did affect the rate and degree of infection, it did not affect any of the pathological parameters examined. This highlighted that the sexual transmission dose may have minimal effect on the development of reproductive sequelae. The results of the first section enabled further studies presented here to use an optimal inoculating dose that would ascend the reproductive tract and cause pathology development, so that vaccine efficacy could be determined. There has been a large amount of research into the development of an efficacious vaccine against genital tract chlamydial infections, with little success. However, there have been no studies examining the effects of the timing of vaccination, including the effects of vaccination during an active genital infection, or after clearance of a previous infection. These are important factors that need to be examined, as it is not yet known whether immunization will enhance not only the individual's immune response, but also pathology development. It is also unknown whether any enhancement of the immune responses will cause the Chlamydia to enter a dormant, persistent state, and possibly further enhance any pathology development. The second section of this study aimed to determine if vaccination during an active genital tract infection, or after clearance of a primary infection, enhanced the murine immune responses and whether any enhanced or reduced pathology occurred. Naïve, actively infected, or previously infected animals were immunized intranasally or transcutaneously with the adjuvants cholera toxin and CpG-ODN in combination with either the major outer membrane protein (MOMP) of C. muridarum, or MOMP and ribonucleotide reductase small chain protein (NrdB) of C. muridarum. It was found that the systemic immune responses in actively or previously infected mice were altered in comparison to animals immunized naïve with the same combinations, however mucosal antibodies were not enhanced. It was also found that there was no difference in pathology development between any of the groups. This suggests that immunization of individuals who may have an asymptomatic infection, or may have been previously exposed to a genital infection, may not benefit from vaccination in terms of enhanced immune responses against re-exposure. The final section of this study aimed to determine if the vaccination regimes mentioned above caused in vivo persistence of C. muridarum in the upper reproductive tracts of mice. As there has been no characterization of C. muridarum persistence in vitro, either ultrastructurally or via transcriptome analysis, this was the first aim of this section. Once it had been shown that C. muridarum could be induced into a persistent state, the gene transcriptional profiles of the selected persistent marker genes were used to determine if persistent infections were indeed present in the upper reproductive tracts of the mice. We found that intranasal immunization during an active infection induced persistent infections in the oviducts, but not the uterine horns, and that intranasal immunization after clearance of infection, caused persistent infections in both the uterine horns and the oviducts of the mice. This is a significant finding, not only because it is the first time that C. muridarum persistence has been characterized in vitro, but also due to the fact that there is minimal characterization of in vivo persistence of any chlamydial species. It is possible that the induction of persistent infections in the reproductive tract might enhance the development of pathology and thereby enhance the risk of infertility, factors that need to be prevented by vaccination, not enhanced. Overall, this study has shown that the inoculating dose does not affect pathology development in the female reproductive tract of infected mice, but does alter the degree and rate of ascending infection. It has also been shown that intranasal immunization during an active genital infection, or after clearance of one, induces persistent infections in the uterine horns and oviducts of mice. This suggests that potential vaccine candidates will need to have these factors closely examined before progressing to clinical trials. This is significant, because if the same situation occurs in humans, a vaccine administered to an asymptomatic, or previously exposed individual may not afford any extra protection and may in fact enhance the risk of development of infection-associated sequelae. This suggests that a vaccine may serve the community better if administered before the commencement of sexual activity.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This article addresses the causal powers associated with the social phenomena of alternative schooling for youth at risk. It stems from a doctoral thesis, Alternative Schooling Programs for At Risk Youth – Three Case Studies which addresses wider issues integral to alternative schooling: youth at risk, alternative schooling models, and literacy. This article explores one aspect of alternative schooling: the historical causal factors involved in the establishment and continuance of three alternative case study models in Queensland, Australia. By adhering to Bhaskar’s transformational model of social activity (TMSA) , social structures and individuals will be analytically distinguished to uncover their separate causal powers and how these have effected the establishment and continuance of three alternative schools.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Introduction This study reports on the development of a self report assessment tool to increase the efficacy of crash prediction within Australian Fleet settings Over last 20 years an array of measures have been produced (Driver anger scale, Driving Skill Inventory, Manchester Driver Behaviour Questionnaire, Driver Attitude Questionnaire, Driver Stress Inventory, Safety Climate Questionnaire) While these tools are useful, research has demonstrated limited ability to accurately identify individuals most likely to be involved in a crash. Reasons cited include; - Crashes are relatively rare - Other competing factors may influence crash event - Ongoing questions regarding the validity of self report measures (common method variance etc) - Lack of contemporary issues relating to fleet driving performance

Relevância:

20.00% 20.00%

Publicador:

Resumo:

• What is risk compensation, and why is relevant to motor vehicle crashes? • Recent simulator work that revealed risk compensation • Current and future work on risk compensation

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Background: Risk of malnutrition in older people continues to be a global problem. Malnutrition is often unrecognized and under-treated across health care settings and may result in undesirable health consequences, impaired recovery from illness and a poorer quality of life. Aim: This study aimed to determine the prevalence of malnutrition risk in a sample of older people at high risk of hospital re-admission. The association between risk factors of hospital re-admission and risk of malnutrition were also explored. Methods: One hundred and twenty five hospitalised patients aged 65 years and older at risk of hospital readmission (24% male, 76% female, mean age 77 ± 6 years) were recruited from a tertiary metropolitan hospital in Australia. The valid and reliable Malnutrition Screen Tool (MST) was employed to screen for malnutrition risk. It consists of two questions related to recent weight loss and appetite. Results: Prevalence of older adults at risk of malnutrition was 27.4%. Risk of malnutrition was not associated with age, gender and living arrangement. However, among risk factors of hospital readmission, lack of social support (χ2 = 4.18, N = 125, p = 0.028), and fair –poor self-rating of health (χ2 = 4.13, N = 125, p = 0.042) were statistically significant associated with risk of malnutrition. Conclusion: Risk of malnutrition in older people continues to be a concern in health care, and increasing psycho social support may help shed light on reducing risk of malnutrition.