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Readiness to change: newspaper coverage of tobacco farming and diversification.

Diversification, like tobacco use prevention and cessation, is an important public health concern. The multilevel patterns of tobacco dependency suggest the need for public health approaches to the "tobacco problem." To understand how newspaper and wire service journalists cover issues involving diversification among tobacco farmers, the authors performed a content analysis of a subset of 100 articles on diversification and tobacco farming. Prochaska and DiClemente's stages of change model was applied to the "problem behavior" of tobacco farming. Among news accounts relating to tobacco farmers or tobacco farming, print media accounts gave relatively little attention to the issue of diversification. Farmers in the sample of news accounts were generally cognizant of pressures to diversify away from reliance on tobacco cultivation but were frustrated due to obstacles to diversification such as limited diversification options and relative absence of infrastructure supports. Community leaders and policy-relevant sources generally supported diversification.

Agriculture↗

State-level income inequality and individual mortality risk: a prospective, multilevel study.

OBJECTIVES: Previous studies have linked state-level income inequality to mortality rates. However, it has been questioned whether the relationship is independent of individual-level income. The present study tests whether state-level income inequality is related to individual mortality risk, after adjustment for individual-level characteristics. METHODS: In this prospective, multilevel study design, the vital status of National Health Interview Survey (NHIS) respondents was ascertained by linkage to the National Death Index, with additional linkage of state-level data to individuals in the NHIS. The analysis included data for 546,888 persons, with 19,379 deaths over the 8-year follow-up period. The Gini coefficient was used as the measure of income inequality. RESULTS: Individuals living in high-income-inequality states were at increased risk of mortality (relative risk = 1.12; 95% confidence interval = 1.04, 1.19) compared with individuals living in low-income-inequality states. In stratified analyses, significant effects of state income inequality on mortality risk were found, primarily for near-poor Whites. CONCLUSIONS: State-level income inequality appears to exert a contextual effect on mortality risk, after income is adjusted for, providing further evidence that the distribution of income is important for health.

Adolescent↗

Knowledge discovery and system biology in molecular medicine: an application on neurodegenerative diseases.

The possibility to study an organism in terms of system theory has been proposed in the past, but only the advancement of molecular biology techniques allow us to investigate the dynamical properties of a biological system in a more quantitative and rational way than before . These new techniques can gave only the basic level view of an organisms functionality. The comprehension of its dynamical behaviour depends on the possibility to perform a multiple level analysis. Functional genomics has stimulated the interest in the investigation the dynamical behaviour of an organism as a whole. These activities are commonly known as System Biology, and its interests ranges from molecules to organs. One of the more promising applications is the 'disease modeling'. The use of experimental models is a common procedure in pharmacological and clinical researches; today this approach is supported by 'in silico' predictive methods. This investigation can be improved by a combination of experimental and computational tools. The Machine Learning (ML) tools are able to process different heterogeneous data sources, taking into account this peculiarity, they could be fruitfully applied to support a multilevel data processing (molecular, cellular and morphological) that is the prerequisite for the formal model design; these techniques can allow us to extract the knowledge for mathematical model development. The aim of our work is the development and implementation of a system that combines ML and dynamical models simulations. The program is addressed to the virtual analysis of the pathways involved in neurodegenerative diseases. These pathologies are multifactorial diseases and the relevance of the different factors has not yet been well elucidated. This is a very complex task; in order to test the integrative approach our program has been limited to the analysis of the effects of a specific protein, the Cyclin dependent kinase 5 (CDK5) which relies on the induction of neuronal apoptosis. The system has a modular structure centred on a textual knowledge discovery approach. The text mining is the only way to enhance the capability to extract ,from multiple data sources, the information required for the dynamical simulator. The user may access the publically available modules through the following site: http://biocomp.ge.ismac.cnr.it.

Biomedical Research↗

Recent advances in management of cerebral palsy.

Recent advances in clinical research have increased our understanding of causal pathways, opportunities for primary prevention, and the value of specific intervention strategies in the management of Cerebral Palsy (CP). Despite the increasing popularity of newer treatment alternatives, e.g., Botulinum Toxin and Intrathecal Baclofen, single event multilevel Orthopaedic bony and soft tissue surgery, in the context of a multi-disciplinary rehabilitation team, remains a vital component in the overall management plan. A meticulous clinical examination, augmented in some cases by instrumented gait analysis, allows for a comprehensive treatment plan addressing the entire extremity. This paper provides a critical review of the currently available treatment modalities.

Cerebral Palsy↗

[Botulinum toxin A in the treatment of infantile cerebral palsy. Taking into account multilevel, integrated treatment].

Botulinum toxin A represents a significant development in the management of children and adolescents with spastic cerebral palsy. Prerequisites for an adequate result are a correct indication, an exact injection technique and an intensive post-treatment programme. Spastic muscle overactivity and the constant tendency of the involved muscles to shorten with growth cannot be treated by only one method. Therefore a multilevel approach and an integrated treatment schedule including plaster of Paris, orthoses and physiotherapy are currently the best ways to modify the disease process. The inclusion of objective clinical documentation techniques combined with 3-D instrumented gait analysis allows the determination of the indications more exactly and for monitoring the post-treatment results. If started early and correctly, this integrated management approach has the potential to modify the natural history of the disorder, and to reduce the frequency of later surgery.

Adult↗

Characterization of the interface in the plasma-sprayed HA coating/Ti-6Al-4V implant system.

The successful use of plasma-sprayed hydroxyapatite (HA) coatings on Ti-alloy implants for implant-to-bone fixation requires strong adherence of the ceramic coating to the underlying metal substrate. In this study, the metal-ceramic interface was evaluated using mechanical, chemical, and structural characterization methods. Evaluations of an HA-coated Ti-6Al-4V implant system using a modified short bar technique for interfacial fracture toughness determination revealed relatively low fracture toughness values. Additionally, conventional tensile bond strength testing indicated much lower values than previously reported. Using high resolution electron spectroscopic imaging, evidence of chemical bonding was revealed at the plasma-sprayed HA/Ti-6Al-4V interface, though bonding was primarily due to mechanical interlock at the interface. This study illustrates the benefits of, and the need for, a multilevel approach to evaluate and improve these plasma-sprayed ceramic-metal substrate interfaces.

Alloys↗

Prognostic significance of metastasis to the highest mediastinal lymph node in nonsmall cell lung cancer.

BACKGROUND: We have tried to clarify the prognostic significance of metastasis to the highest mediastinal (HM) lymph node in patients with N2 lung cancer who underwent complete dissection of superior mediastinal (including HM) lymph nodes. METHODS: This study analyzed 53 patients with N2 nonsmall cell lung cancer who underwent surgical procedures such as lobectomy plus hilar and mediastinal node dissection (T4, neoadjuvant therapy cases were excluded). For patients whose cancer was in the left lung, we performed surgery through the median sternotomy in order to dissect superior mediastinal nodes. The clinicopathologic records of the patients were examined for prognostic factors such as age, sex, side, histology, tumor location, tumor size, clinical node (cN) number, preoperative serum carcinoembryonic antigen level, number of metastatic stations, and HM lymph node involvement. RESULTS: A univariate analysis showed that tumor size (T1/T2-3), cN factor (cN1-2/cN0), N2 level (multiple/single), and metastasis to the HM node were significant prognostic factors. In the multivariate analysis, metastasis to the HM lymph node remained a significant prognostic factor (p = 0.026). The 3-year survival rates were 52% in patients without metastasis to the HM lymph node and 21% in patients with metastasis to the HM lymph node (p < 0.001). Furthermore, when HM nodal involvement was absent, the 5-year survival rate was 33% even in patients with multilevel N2 status, 45% in patients with cN1-2 status, and 47% in patients with pT2-3 tumor status. CONCLUSIONS: Highest mediastinal lymph node involvement is prognostic of highly advanced N2 disease resulting in poor outcome. The results also suggest that patients with no involvement of the HM lymph node can experience acceptable postoperative outcomes even if they have multilevel N2 status, positive cN status, or T2-3 tumor status.

Adenocarcinoma↗

Changing times: a longitudinal analysis of international firearm suicide data.

We investigated changes in the proportion of firearm suicides in Western countries since the 1980s and the relation of these changes to the change in the proportion of households owning firearms. Several countries had an obvious decline in firearm suicides: Norway, United Kingdom, Canada, Australia, and New Zealand. Multilevel modeling of longitudinal data confirmed the effect of the proportion of households owning firearms. Legislation and regulatory measures reducing the availability of firearms in private households can distinctly strengthen the prevention of firearm suicides.

Australia↗

Abdominal surgery reduces the ability of rat spleen cells to synthesize and secrete active tumour necrosis factor-alpha (TNF-alpha) by a multilevel regulation.

We have previously shown that abdominal surgery (explorative laparotomy) reduces the ability of lipopolysaccharide (LPS)-triggered spleen macrophages to secrete TNF-alpha. In this study we characterize possible mechanisms which could be responsible for the reduction in splenic production of TNF-alpha. Post-operative and control (unoperated) rat splenocytes or enriched splenic macrophages were cultured with LPS. Steady-state levels of TNF-alpha mRNA were determined by Northern and slot blot analyses, and validated by quantitative reverse transcriptase-polymerase chain reaction (RT-PCR). The amount of TNF-alpha protein was measured by Western blot analysis, and its biological activity was determined by the fibroblast L-929 cytotoxicity assay. Surgery induced a 12-fold inhibition in TNF-alpha activity (P < 0.02), caused up to two-fold reduction in the accumulation of TNF-alpha mRNA (P < 0.01), and suppressed TNF-alpha protein maturation into its 17-kD form in cellular extracts. Post-surgical spleen supernatants revealed mainly a band of a lower molecular weight (14 kD). Our data suggest a multilevel regulation of post-operative inhibition of TNF-alpha response to LPS, at the accumulation of mRNA, translational and secretory levels. We also suggest that the reduced bioactivity could be partially caused by a proteolytic cleavage of TNF-alpha. Since TNF-alpha is an important participant in immune responses, its reduced production and activity may be a central mechanism of post-operative immunosuppression.

Animals↗

The factorial survey: an experimental method to replicate real world problems.

BACKGROUND: Vignettes are used by nurse researchers use to determine how clinical judgments about patient care situations are made. However, when vignettes are designed there is often a restriction on the number of characteristics studied, which oversimplifies the richness and complexity of real world healthcare situations. OBJECTIVES: The purpose of this article is to describe a factorial survey. Its multilevel design of independent variables allows for real world complexity in a way not tested by a sample set of four to six identical vignettes. Nurses' judgments about patients' confusion and the application of restraints are used to illustrate the method. METHOD: The factorial survey is an experimental design that can be developed in three steps: (a) identifying and using the variables, (b) writing a coherent vignette, and (c) randomly generating the vignettes. RESULTS: The unit of analysis is the vignette and Ordinary Least Squares (OLS) regression is used for analyses. In the example provided on confusion recognition and restraint use, patient characteristics accounted for the majority of explained variance in confusion recognition of (40%, R2 = 0.40) and restraint intervention for (43%, R2 = 0.43). The results for both models were strikingly similar as the same patient characteristics all were significant predictors for confusion recognition and restraint use. CONCLUSIONS: The versatility of the factorial survey lies in the researcher's ability to use it to test judgments in a variety of complex clinical simulations, to aid in concept development, and to identify consensus and disagreement among nurses. The multilevel design of the independent variables allows for real world complexity in a way not tested by a sample set of four to six identical vignettes.

Clinical Competence↗

Assessment of operative risk in colorectal cancer surgery: the Cleveland Clinic Foundation colorectal cancer model.

INTRODUCTION: Predictive models play a pivotal role in the provision of risk-adjusted, operative mortality rates. The purpose of the study was to describe the development of a dedicated prognostic index for quantifying operative risk in colorectal cancer surgery. METHODS: Data were collected from 5,034 consecutive patients undergoing major surgery in a single center from October 1976 to July 2002. Primary end point was 30-day operative mortality. A multilevel Bayesian logistic regression model was developed to adjust for case-mix and accommodate the variability of outcomes between surgeons. The model was internally validated (split-sample) and tested using measures of discrimination, calibration, and subgroup analysis. RESULTS: The patients' median age was 66 (range, 18-98) years. Operative mortality was 2.3 percent with no significant variability between surgeons or through time. Multivariate analysis identified the following independent risk factors: age (odds ratio = 1.5 per 10-year increase), American Society of Anesthesiologists grade (odds ratio for ASA II, III, IV-V vs. I = 2.6, 4.3, 6.8), TNM staging (odds ratio for Stage IV vs. I-III = 2.6), mode of surgery (odds ratio for urgent vs. nonurgent = 2.1) no-cancer resection vs. cancer resection (odds ratio = 4.5), and hematocrit level. The model offered adequate discrimination (area under receiver operator characteristic curve = 0.801) and excellent agreement between observed and model-predicted outcomes over ten major colorectal procedures (P = 0.191). CONCLUSIONS: The colorectal cancer model provided an accurate means of estimating risk for individual patients in the preoperative setting. It has important implications in everyday practice, because it may be used as an adjunct in the process of informed consent and for monitoring surgical performance through time.

Adolescent↗

Isotopic modelling of the significance of bacterial sulphate reduction for phenol attenuation in a contaminated aquifer.

A Triassic sandstone aquifer polluted with a mixture of phenolic hydrocarbons has been investigated by means of high-resolution groundwater sampling. Samples taken at depth intervals of 1 m have revealed the presence of a diving pollutant plume with a sharply defined upper margin. Concentrations of pollutant phenols exceed 4 g/l in the plume core, rendering it sterile but towards the diluted upper margin evidence for bacterial sulphate reduction (BSR) has been obtained. Groundwaters have been analysed for both delta34S-SO4 and delta18O-SO4. Two reservoirs have been identified with distinct sulphate oxygen isotope ratios. Groundwater sulphate (delta18O-SO4 = 3-5/1000) outside the plume shows a simple linear mixing trend with an isotopically uniform pollutant sulphate reservoir (delta18O-SO4 = 10-12/1000) across the plume margin. The sulphur isotope ratios do not always obey a simple mixing relation, however, at one multilevel borehole, enrichment in 34SO4 at the plume margin is inversely correlated with sulphate concentration. This and the presence of 34S-depleted dissolved sulphide indicate that enrichment in 34SO4 is the result of bacterial sulphate reduction. Delta34S analysis of trace hydrogen sulphide within the plume yielded an isotope enrichment factor (epsilon) of -9.4/1000 for present-day bacterial sulphate reduction. This value agrees with a long-term estimate (-9.9/1000) obtained from a Rayleigh model of the sulphate reduction process. The model was also used to obtain an estimate of the pre-reduction sulphate concentration profile with depth. The difference between this and the present-day profiles then gave a mass balance for sulphate consumption. The organic carbon mineralisation that would account for this sulphate loss is shown to represent only 0.1/1000 of the phenol concentration in this region of the plume. Hence, the contribution of bacterial sulphate reduction to biodegradation has thus far been small. The highest total phenolic concentration (TPC) at which there is sulphur isotope evidence of bacterial sulphate reduction is 2000 mg/l. We suggest that above this concentration, the bactericidal properties of phenol render sulphate-reducing bacteria inactive. Dissolved sulphate trapped in the concentrated plume core will only be utilised by sulphate reducers when toxic phenols in the plume are diluted by dispersion during migration.

Biodegradation, Environmental↗

Making the case for psychophysiology during the era of molecular biology.

The Office of Behavioral and Social Sciences Research (OBSSR) at the National Institutes of Health opened in 1995 to facilitate the advancement of research on social and behavioral influences on health. The establishment of the OBSSR coincided with the ascendancy of molecular biology, with its emphasis on more reductionistic influences on health. This greater emphasis on genetic aspects of health has the potential to produce a widening chasm between biomedical research and social, behavioral, and psychological research. We discuss the chasm between sociobehavioral and biomedical research during what might be considered the era of molecular biology and propose the concept of levels of analysis as a unifying framework for research in the health sciences, using research on hypertension in African Americans as a representative example. We also argue for the primacy of psychophysiological research in bridging the chasm and furthering a multilevel perspective and summarize some of the activities of the OBSSR that are relevant to this perspective.

Animals↗

Botulinum A toxin for treatment of lower limb spasticity in cerebral palsy: gait analysis in 49 patients.

BACKGROUND: Injection of botulinum type A toxin is a new treatment for spasticity. PATIENTS AND METHODS: We evaluated the effect of botulinum A toxin (BTX-A) in the lower limb muscles of patients having cerebral palsy. We tested 49 patients before and, on average, 4 (2-9) months after giving the toxin. The evaluation included 3-dimensional computerized gait analysis, changes in mobility level, using the Gillette Functional Assessment Questionnaire, and gastrocnemius muscle bulk, using ultrasonographic measurements. RESULTS: The patients were divided into 3 groups, according to the site of BTX-A administration (hamstrings, gastrocnemius and multilevel). Those who were injected in the hamstrings showed a significant improvement in only the maximum knee extension angle during the gait cycle. Those with spastic equinus who were injected in the gastrocnemius muscle responded better than the other groups. The ankle angle on the initial contact, terminal stance and pre-swing, maximum dorsiflexion, ankle range of motion, per cent of single support and gait velocity improved significantly. Overall, the patients showed significant improvements in motor skill performance and functional health. INTERPRETATION: Our findings indicate that botulinum type A toxin can be given as an adjuvant to conservative treatment of patients with cerebral palsy.

Adolescent↗

Individual and regional determinants of mammography uptake.

BACKGROUND: Analysis of mammography utilization has traditionally been performed from an individual-level perspective. The purpose of this study was to explore the combined influence of individual- and regional-level determinants of mammography utilization. METHODS: Logistic hierarchical multilevel modelling was used to investigate the influences of region of residence and individual characteristics on mammography utilization. Socioeconomic status information about health planning regions was derived from the 1996 Canadian Census. Individual-level information was extracted from the 1996 National Population Health Survey. RESULTS: After controlling for individual-level education, regions with fewer high school graduates had lower levels of mammography utilization. A cross-level interaction between regional-level education and individual-level social involvement was found. Other individual-level variables associated with screening confirmed previous literature findings. CONCLUSION: Our findings suggest that higher levels of participation in social activities modify the detrimental influence on mammography utilization of living in a less educated region. This challenges the current focus of mammography screening research on individual-level determinants of uptake. Multilevel, synergistic strategies to possibly achieve higher levels of screening should be considered by health promotion program planners.

Aged↗

[Sympathetic nervous system, pain and epidural administration of morphine].

There are multilevel intrications between nociceptive afferences and sympathetic efferences: anatomical vicinity in visceral innervation; systemic and local activation of the sympathetic efferences in response to nociceptive stimulation; major role of sympathetic activation in the perpetuation of sympathetic dystrophies. The analysis of a retrospective series of 10 patients suffering from algodystrophia revealed that epidural morphine administration had a beneficial effect only in those which were treated at an early stage of their illness. Despite epidural morphine has been claimed to be without effect on the efferent sympathetic tone in normal animals and individuals, it seems that in some pathologic states, the sympathetic output can be depressed. Recent anatomical and neurophysiological evidences argue for such a possibility.

Analgesia, Epidural↗

Peak oxygen uptake in relation to growth and maturation in 11- to 17-year-old humans.

This study used multilevel modelling to examine peak oxygen uptake (VO2peak) during growth and maturation. Body mass, stature, triceps and subscapular skinfold thicknesses, blood haemoglobin concentration, and VO2peak of boys and girls, [mean (SD)] aged 11.1 (0.4) years at the onset of the study, were measured at ages 11, 12, 13 and 17 years. Sexual maturation was assessed on the first three occasions and was assumed to be Tanner stage 5 at 17 years. The analysis was founded on 388 VO2peak determinations from 132 children. The initial model revealed mass, stature and age as significant explanatory variables of VO2peak with an additional positive effect for stage of maturity. Girls' values were significantly lower than those of boys and a significant age-by-sex interaction described a progressive divergence in boys' and girls' VO2peak. The introduction of skinfold thicknesses produced a model with an improvement in fit. The stature term was negated and the mass exponent almost doubled. The sex and age-by-sex terms were reduced but remained significant. Many of the observed maturity effects were explained with stage 5 becoming non-significant. Blood haemoglobin concentration was a nonsignificant parameter estimate in both models. Fat-free mass was the dominant influence on the growth of VO2peak but the multilevel regression models demonstrated that, with body size and fatness allowed for, VO2peak increased with age and maturation in both sexes.

Adolescent↗

Mediational analysis in HIV/AIDS research: estimating multivariate path analytic models in a structural equation modeling framework.

Mediational analyses have been recognized as useful in answering two broad questions that arise in HIV/AIDS research, those of theoretical model testing and of the effectiveness of multicomponent interventions. This article serves as a primer for those wishing to use mediation techniques in their own research, with a specific focus on mediation applied in the context of path analysis within a structural equation modeling (SEM) framework. Mediational analyses and the SEM framework are reviewed at a general level, followed by a discussion of the techniques as applied to complex research designs, such as models with multiple mediators, multilevel or longitudinal data, categorical outcomes, and problematic data (e.g., missing data, nonnormally distributed variables). Issues of statistical power and of testing the significance of the mediated effect are also discussed. Concrete examples that include computer syntax and output are provided to demonstrate the application of these techniques to testing a theoretical model and to the evaluation of a multicomponent intervention.

Data Interpretation, Statistical↗