Combining two potential causes of metalloproteinase secretion causes abdominal aortic aneurysms in rats: a new experimental model

P>Progress in understanding the pathophysiology of abdominal aortic aneurysms (AAA) is dependent in part on the development and application of effective animal models that recapitulate key aspects of the disease. The objective was to produce an experimental model of AAA in rats by combining two potential causes of metalloproteinase (MMP) secretion: inflammation and turbulent blood flow. Male Wistar rats were randomly divided in four groups: Injury, Stenosis, Aneurysm and Control (40/group). The Injury group received a traumatic injury to the external aortic wall. The Stenosis group received an extrinsic stenosis at a corresponding location. The Aneurysm group received both the injury and stenosis simultaneously, and the Control group received a sham operation. Animals were euthanized at days 1, 3, 7 and 15. Aorta and/or aneurysms were collected and the fragments were fixed for morphologic, immunohistochemistry and morphometric analyses or frozen for MMP assays. AAAs had developed by day 3 in 60-70% of the animals, reaching an aortic dilatation ratio of more than 300%, exhibiting intense wall remodelling initiated at the adventitia and characterized by an obvious inflammatory infiltrate, mesenchymal proliferation, neoangiogenesis, elastin degradation and collagen deposition. Immunohistochemistry and zymography studies displayed significantly increased expressions of MMP-2 and MMP-9 in aneurysm walls compared to other groups. The haemo-dynamic alterations caused by the stenosis may have provided additional contribution to the MMPs liberation. This new model illustrated that AAA can be multifactorial and confirmed the key roles of MMP-2 and MMP-9 in this dynamic remodelling process.

Expression of fibroblast growth factor receptors during development and regression of the bovine corpus luteum

There is evidence that fibroblast growth factors (FGFs) are involved in the regulation of growth and regression of the corpus luteum (CL). However, the expression pattern of most FGF receptors (FGFRs) during CL lifespan is still unknown. The objective of the present study was to determine the pattern of expression of `B` and `C` splice variants of FGFRs in the bovine CL. Bovine CL were collected from an abattoir and classed as corpora hemorrhagica (Stage I), developing (Stage II), developed (Stage III) or regressed (Stage IV) CL. Expression of FGFR mRNA was measured by semiquantitative reverse transcription-polymerase chain reaction and FGFR protein was localised by immunohistochemistry. Expression of mRNA encoding the `B` and `C` spliced forms of FGFR1 and FGFR2 was readily detectable in the bovine CL and was accompanied by protein localisation. FGFR1C and FGFR2C mRNA expression did not vary throughout CL lifespan, whereas FGFR1B was upregulated in the developed (Stage III) CL. FGFR3B, FGFR3C and FGFR4 expression was inconsistent in the bovine CL. The present data indicate that FGFR1 and FGFR2 splice variants are the main receptors for FGF action in the bovine CL.

Comparison between computed tomography and clinical evaluation in tumour/node stage and follow-up of oral cavity and oropharyngeal cancer

Objectives: The aim was to verify the concordance of CT evaluation among four radiologists (two oral and maxillofacial and two medical radiologists) at the TN (tumour/node) stage and in the follow-up of oral cavity and oropharyngeal cancer patients. The study also compared differences between clinical and CT examinations in determining the TN stage. Methods: The following clinical and tomographic findings of 15 non-treated oral cavity and oropharyngeal cancer patients were compared: tumour size, bone invasion and lymph node metastases. In another 15 patients, who had previously been treated, a clinical and tomographic analysis comparison for the presence of tumoural recurrence, post-therapeutic changes in muscles and lymph node metastases was performed. The concordances of tomographic evaluation between the radiologists were analysed using the kappa index. Results: Significant agreement was verified between all radiologists for the T stage, but not for the N stage. In the group of treated patients, CT disclosed post-therapeutic changes in muscles, tumour recurrence and lymph node metastases, but no concordance for the detection of lymph node metastases was found between radiologists. In the first group, for all radiologists, no concordance was demonstrated between clinical and tomographic staging. CT was effective for delimitating advanced lesions and for detecting lymph node involvement in N0 stage patients. CT revealed two cases of bone invasion not clinically detected. Conclusions: Interprofessional relationships must be stimulated to improve diagnoses, and to promote a multidisciplinary approach to oral cavity and oropharyngeal cancer. Although CT was important in the diagnosis and follow-up of cancer patients, differences between medical and dental analyses should be acknowledged. Dentomaxillofacial Radiology (2010) 39, 140-148. doi: 10.1259/dmfr/69910245

Laboratory evaluation of two native fishes from tropical North Queensland as biological control agents of subterranean Aedes aegypti

The ability of 2 freshwater fishes, eastern rainbow fish Melanotaenia splendida splendida and fly-specked hardyhead Craterocephalus stercusmuscarum stercusmuscarum. native to North Queensland to prey on immature Aedes aegypti was evaluated under laboratory conditions. The predation efficiency of the 2 species was compared to the exotic guppy, Poecilia reticulata, which is commonly used as a biological control agent of mosquito larvae. Of the 3 fish species tested, M. s. splendida was shown to be the most promising agent for the biological control of Ae. aegypti that breed in wells. Melanotaenia s. splendida consumed significantly greater numbers of immature Ae. aegypti than P. reticulata, irrespective of developmental stage or light conditions. Unlike C. s. stercusmuscarum, M, s. splendida could be handled, transported, and kept in captivity for extended periods with negligible mortality. However, M. s. splendida was also an efficient predator of Litoria caerulea tadpoles, a species of native frog found in wells during the dry season. This result may limit the usefulness of M. s. splendida as a biological control agent of well-breeding Ae. aegypti and suggests that predacious copepods, Mesocyclops spp., are more suitable. However, the use of M. s. splendida as a mosquito control agent in containers that are unlikely to support frog populations (e.g., aquaculture tanks and drinking troughs) should be given serious consideration.

Model specification tests in nonparametric stochastic regression models

In this paper, we consider testing for additivity in a class of nonparametric stochastic regression models. Two test statistics are constructed and their asymptotic distributions are established. We also conduct a small sample study for one of the test statistics through a simulated example. (C) 2002 Elsevier Science (USA).

Identification of T cell epitopes on the 33-kDa fragment of Plasmodium yoelii merozoite surface protein 1 and their antibody-independent protective role in immunity to blood stage malarial

Merozoite surface protein 1 (MSP1) of malaria parasites undergoes proteolytic processing at least twice before invasion into a new RBC. The 42-kDa fragment, a product of primary processing, is cleaved by proteolytic enzymes giving rise to MSP1(33), which is shed from the merozoite surface, and MSP1(19), which is the only fragment carried into a new RBC. In this study, we have identified T cell epitopes on MSP1(33) of Plasmodium yoelii and have examined their function in immunity to blood stage malaria. Peptides 20 aa in length, spanning the length of MSP1(33) and overlapping each other by 10 aa, were analyzed for their ability to induce T cell proliferation in immunized BALB/c and C57BL/6 mice. Multiple epitopes were recognized by these two strains of mice. Effector functions of the dominant epitopes were then investigated. Peptides Cm15 and Cm21 were of particular interest as they were able to induce effector T cells capable of delaying growth of lethal P. yoelii YM following adoptive transfer into immuno-deficient mice without inducing detectable Ab responses. Homologs of these epitopes could be candidates for inclusion in a subunit vaccine.

An EM-based Semi-Parametric Mixture Model Approach to the Regression Analysis of Competing-Risks Data

We consider a mixture model approach to the regression analysis of competing-risks data. Attention is focused on inference concerning the effects of factors on both the probability of occurrence and the hazard rate conditional on each of the failure types. These two quantities are specified in the mixture model using the logistic model and the proportional hazards model, respectively. We propose a semi-parametric mixture method to estimate the logistic and regression coefficients jointly, whereby the component-baseline hazard functions are completely unspecified. Estimation is based on maximum likelihood on the basis of the full likelihood, implemented via an expectation-conditional maximization (ECM) algorithm. Simulation studies are performed to compare the performance of the proposed semi-parametric method with a fully parametric mixture approach. The results show that when the component-baseline hazard is monotonic increasing, the semi-parametric and fully parametric mixture approaches are comparable for mildly and moderately censored samples. When the component-baseline hazard is not monotonic increasing, the semi-parametric method consistently provides less biased estimates than a fully parametric approach and is comparable in efficiency in the estimation of the parameters for all levels of censoring. The methods are illustrated using a real data set of prostate cancer patients treated with different dosages of the drug diethylstilbestrol. Copyright (C) 2003 John Wiley Sons, Ltd.

Sitting time and work patterns as indicators of overweight and obesity in Australian adults

BACKGROUND: Increasing levels of physical inactivity and sedentariness are contributing to the current overweight and obesity epidemic. In this paper, the findings of two recent studies are used to explore the relationships between sitting time ( in transport, work and leisure), physical activity and body mass index (BMI) in two contrasting samples of adult Australians. METHODS: Data on sitting time, physical activity, BMI and a number of demographic characteristics were compared for participants in two studies-529 women who were participants in a preschool health promotion project ('mothers'), and 185 men and women who were involved in a workplace pedometer study ('workers'). Relationships between age, number of children, physical activity, sitting time, BMI, gender and work patterns were explored. Logistic regression was used to predict the likelihood of being overweight or obese, among participants with different physical activity, sitting time and work patterns. RESULTS: The total reported time spent sitting per day ( across all domains) was almost 6 h less among the mothers than the workers (P

Reliability of moderate-intensity and vigorous physical activity stage of change measures for young adults

Background. The purpose of this study was to examine the reliability of stage of change (SOC) measures for moderate-intensity and vigorous physical activity in two separate samples of young adults. Staging measures have focused on vigorous exercise, but current public health guidelines emphasize moderate-intensity activity. Method. For college students in the USA (n = 105) and in Australia (n = 123), SOC was assessed separately on two occasions for moderate-intensity activity and for vigorous activity. Test-retest repeatability was determined, using Cohen's kappa coefficient. Results. In both samples, the reliability scores for the moderate-intensity physical activity staging measure were lower than the scores for the vigorous exercise staging measure. Weighted kappa values for the moderate-intensity staging measure were in the fair to good range for both studies (0.50 and 0.45); for the vigorous staging measure kappa values were excellent and fair to good (0.76 and 0.72). Conclusions. There is a need to standardize and improve methods for staging moderate-intensity activity, given that such measures are used in public health interventions targeting HEPA (health-enhancing physical activity). (C) 2003 American Health Foundation and Elsevier Science (USA). All rights reserved.

Improving the environmental performance of bedding products by using life cycle assessment at the design stage

Improvement of the environmental performance of processes and products is a common objective in industry, and has been receiving increased attention in recent years. The main objective of this work is to evaluate the potential environmental impact of two bedding products, a polyurethane foam mattress (PFM) and a pocket spring mattress (PSM). These two types are the most common mattresses used in Europe. A Life Cycle Assessment (LCA) shows that the PFM has a higher environmental impact than the PSM. For both products the main cause of environmental impact is the manufacturing process, respectively the polyurethane foam block moulding process for the PFM, and the pocket spring nucleus process for the PSM. A scenario analysis shows the possibility of reducing the environmental impact of the products’ life cycle using an alternative End-of-Life scenario, resorting to incineration rather than landfill. Two strategies were also studied in order to reduce the environmental impact of the PFM: (1) reutilization of foam that was sent to the waste system management, and (2) a 20% weight reduction of the polyurethane foam. The second strategy has proven to be the most effective.

Infant mortality: comparison between two birth cohorts from Southeast and Northeast, Brazil

OBJECTIVE: To obtain population estimates and profile risk factors for infant mortality in two birth cohorts and compare them among cities of different regions in Brazil. METHODS: In Ribeirão Preto, southeast Brazil, infant mortality was determined in a third of hospital live births (2,846 singleton deliveries) in 1994. In São Luís, northeast Brazil, data were obtained using systematic sampling of births stratified by maternity unit (2,443 singleton deliveries) in 1997-1998. Mothers answered standardized questionnaires shortly after delivery and information on infant deaths was retrieved from hospitals, registries and the States Health Secretarys' Office. The relative risk (RR) was estimated by Poisson regression. RESULTS: In São Luís, the infant mortality rate was 26.6/1,000 live births, the neonatal mortality rate was 18.4/1,000 and the post-neonatal mortality rate was 8.2/1,000, all higher than those observed in Ribeirão Preto (16.9, 10.9 and 6.0 per 1,000, respectively). Adjusted analysis revealed that previous stillbirths (RR=3.67 vs 4.13) and maternal age <18 years (RR=2.62 vs 2.59) were risk factors for infant mortality in the two cities. Inadequate prenatal care (RR=2.00) and male sex (RR=1.79) were risk factors in São Luís only, and a dwelling with 5 or more residents was a protective factor (RR=0.53). In Ribeirão Preto, maternal smoking was associated with infant mortality (RR=2.64). CONCLUSIONS: In addition to socioeconomic inequalities, differences in access to and quality of medical care between cities had an impact on infant mortality rates.

Living conditions and receptive vocabulary of children aged two to five years

OBJECTIVE: To assess the receptive vocabulary of children aged between two years and six months and five years and eleven months who were attending childcare centers and kindergarten schools. METHODS: An analytical cross-sectional study was carried out in the municipality of Embu, Southeastern Brazil. The Peabody Picture Vocabulary Test and analysis of factors associated with children's performance were applied. The sample consisted of 201 children of both genders, aged between two and six years. Statistical analysis was performed using multivariate analysis and logistic regression model. The dependent variable analyzed was test performance and the independent variables were child's age, mother's level of education and family socio-demographic characteristics. RESULTS: It was observed that 44.3% of the children had performances in the test that were below what would be expected for their age. The factors associated with the best performances in the test were child's age (OR=2.4; 95% CI: 1.6-3.5) and mother's education level (OR= 3.2; 95% CI: 1.3-7.4). CONCLUSIONS: Mother's education level is important for child's language development. Settings such as childcare and kindergarten schools are protective factors for child development in families of low income and education.

Permanent vascular access in patients with end-stage renal disease, Brazil

OBJECTIVE: To assess factors associated with the establishment of permanent vascular access for patients with end-stage renal disease. METHODS: Cross-sectional study conducted in a nationally representative sample of Brazilian end-stage renal disease patients in dialysis and transplant centers during 2007. The sample comprised only patients who received hemodialysis as a primary therapy modality and reported the type of vascular access for their primary hemodialysis treatment (N=2,276). Data were from the TRS Project - "Economic and Epidemiologic Evaluation of Modalities of Renal Replacement Therapy in Brazil". Multiple logistic regression analysis was used to assess factors associated with the establishment of permanent vascular access in these patients. RESULTS: About 30% of the patients studied had an arteriovenous vascular access. The following factors were associated with a lower likelihood of having an arteriovenous vascular access as a primary type of access: time of hemodialysis start since the diagnosis of chronic renal failure < 1 year; shorter dialysis therapy; having no private health insurance; living in the central-western, northeastern and southeastern regions of Brazil; and living in the northern region plus having no private health insurance. In the final model there was found a positive association between the outcome and pre-dialysis care and no were association with socioeconomic and comorbidity variables. CONCLUSIONS: The study results showed that the focus should on pre-dialysis care to increase the establishment of an arteriovenous vascular access before starting hemodialysis in Brazil.

Social contextual factors contributing to child and adolescent labor: an ecological analysis

OBJECTIVE: To examine the relationship between social contextual factors and child and adolescent labor. METHODS: Population-based cohort study carried out with 2,512 families living in 23 subareas of a large urban city in Brazil from 2000 to 2002. A random one-stage cluster sampling was used to select families. Data were obtained through individual household interviews using questionnaires. The annual cumulative incidence of child and adolescent labor was estimated for each district. New child and adolescent labor cases were those who had their first job over the two-year follow-up. The annual cumulative incidence of child and adolescent labor was the response variable and predictors were contextual factors such as lack of social support, social deprivation, unstructured family, perceived violence, poor school quality, poor environment conditions, and poor public services. Pearson's correlation and multiple linear regression were used to assess the associations. RESULTS: There were selected 943 families corresponding to 1,326 non-working children and adolescents aged 8 to 17 years. Lack of social support, social deprivation, perceived violence were all positively and individually associated with the annual cumulative incidence of child and adolescent labor. In the multiple linear regression model, however, only lack of social support and perceived violence in the neighborhood were positively associated to child and adolescent labor. No effect was found for poor school quality, poor environment conditions, poor public services or unstructured family. CONCLUSIONS: Poverty reduction programs can reduce the contextual factors associated with child and adolescent labor. Violence reduction programs and strengthening social support at the community level may contribute to reduce CAL.