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PubMed2000

Estimating the administrative cost of regulatory noncompliance: a pilot method for quantifying the value of prevention.

Routine regulatory inspections provide a valuable independent quality assurance review of radiation protection programs that ultimately serves to improve overall program performance. But when an item of non-compliance is noted, regardless of its significance or severity the ensuing notice of violation (NOV) results in an added cost to both the permit holder and the regulatory authority. Such added costs may be tangible, in the form of added work to process and resolve the NOV, or intangible, in the form of damage to organizational reputation or worker morale. If the portion of the tangible costs incurred by a regulatory agency for issuing NOVs could be quantified, the analysis could aid in the identification of agency resources that might be dedicated to other areas such as prevention. Ideally, any prevention activities would reduce the overall number of NOVs issued without impacting the routine inspection process. In this study, the administrative costs of NOV issuance and resolution was estimated by obtaining data from the professional staff of the Texas Department of Health, Bureau of Radiation Control (TDH-BRC). Based a focus group model, the data indicate that approximately $106,000 in TDH-BRC personnel resources were expended to process and resolve the 6,800 NOVs issued in Texas during 1997 inspection activities. The study's findings imply that an incremental decrease in the number of NOVs issued would result in corresponding savings of agency resources. Suggested prevention activities that might be financed through any resource savings include the dissemination of common violation data to permit holders or training for improving correspondence with regulatory agencies. The significance of this exercise is that any savings experienced by an agency could enhance permittee compliance without impacting the routine inspection process.

Costs and Cost Analysis↗

PubMed2004

Gene expression profiling of human cancers.

DNA microarrays allow us to visualize simultaneously the expression of potentially all genes within a cell population or tissue sample-revealing the "transcriptome." The analysis of this type of data is commonly called "gene expression profiling" (GEP) because it provides a comprehensive picture of the pattern of gene expression in a particular biological sample. For this reason microarrays are revolutionizing life sciences research and are leading to the development of novel and powerful methods for investigating cancer biology, classifying cancers, and predicting clinical outcome of cancers. Several recent high-profile reports have revealed how clustering of GEP data can clearly identify clinically (and prognostically) important subtypes of cancer among patients considered by established clinicopathological criteria to have similar tumors. Accurate "prognostic signatures" can be obtained from GEP data, which represent relatively small numbers of genes. These signatures can be valuable in directing appropriate treatment and in predicting clinical outcome, and they generally outperform other systems based on clinical and histological criteria. In this paper the basic principles of DNA microarray technology and the different types of microarray platforms available will be introduced, and the power of the technique will be illustrated by reviewing some recent GEP studies on selected cancers, including a preliminary analysis of hepatocellular carcinoma from our Palermo laboratory. GEP is likely to be adopted in the future as a key decision-making tool in the clinical arena. However, several issues relating to data analysis, reproducibility, cross-comparability, validation, and cost need to be resolved before the technology can be adopted broadly in this context.

Carcinoma, Hepatocellular↗

PubMed1992

Suspected cross-reactivity of enalapril- and captopril-induced hepatotoxicity.

OBJECTIVE: To present evidence that enalapril and captopril may produce hepatotoxicity by a common mechanism. DATA SOURCES: A case report and review of pertinent literature. DATA SYNTHESIS: A patient developed hepatotoxicity once while taking enalapril and again while taking captopril. Hepatotoxicity resolved with cessation of therapy. Hepatotoxicity has been reported with use of captopril, enalapril, and lisinopril. Apparent cross-reactivity has been reported on just one other occasion. CONCLUSIONS: Because hepatotoxicity is uncommon with angiotensin-converting enzyme (ACE) inhibitors, our observations suggest the possibility that these agents produce hepatotoxicity by a common mechanism. In patients who develop hepatotoxicity while taking one ACE inhibitor, other agents in this class probably should be avoided.

Alanine Transaminase↗

PubMed2006

[caCORE: core architecture of bioinformation on cancer research in America].

A critical factor in the advancement of biomedical research is the ease with which data can be integrated, redistributed and analyzed both within and across domains. This paper summarizes the Biomedical Information Core Infrastructure built by National Cancer Institute Center for Bioinformatics in America (NCICB). The main product from the Core Infrastructure is caCORE--cancer Common Ontologic Reference Environment, which is the infrastructure backbone supporting data management and application development at NCICB. The paper explains the structure and function of caCORE: (1) Enterprise Vocabulary Services (EVS). They provide controlled vocabulary, dictionary and thesaurus services, and EVS produces the NCI Thesaurus and the NCI Metathesaurus; (2) The Cancer Data Standards Repository (caDSR). It provides a metadata registry for common data elements. (3) Cancer Bioinformatics Infrastructure Objects (caBIO). They provide Java, Simple Object Access Protocol and HTTP-XML application programming interfaces. The vision for caCORE is to provide a common data management framework that will support the consistency, clarity, and comparability of biomedical research data and information. In addition to providing facilities for data management and redistribution, caCORE helps solve problems of data integration. All NCICB-developed caCORE components are distributed under open-source licenses that support unrestricted usage by both non-profit and commercial entities, and caCORE has laid the foundation for a number of scientific and clinical applications. Based on it, the paper expounds caCORE-base applications simply in several NCI projects, of which one is CMAP (Cancer Molecular Analysis Project), and the other is caBIG (Cancer Biomedical Informatics Grid). In the end, the paper also gives good prospects of caCORE, and while caCORE was born out of the needs of the cancer research community, it is intended to serve as a general resource. Cancer research has historically contributed to many areas beyond tumor biology. At the same time, the paper makes some suggestions about the study at the present time on biomedical informatics in China.

Computational Biology↗

PubMed1997

Death certification in treated cases of presenile Alzheimer's disease and vascular dementia in Scotland.

INTRODUCTION: although death certification data are commonly used in dementia epidemiology, their reliability has been questioned. METHODS: death certificates were available from the Registrar General for Scotland for all patients with Alzheimer's disease/presenile dementia (AD PSD) or vascular dementia (VaD) who had died in Scotland up until 31 December 1994. Primary (immediate and underlying) and contributory causes of death were noted as well as place of death. Occupations of male patients were obtained from death certificates or from case notes and classified according to the Standard Occupational Classification. Bronchopneumonia was considered a non-specific cause of death and specific causes of death were classified as: cardiac disease, dementia, cerebrovascular disease, neoplasms, other vascular diseases and other diseases. Place of death was recorded as psychiatric hospital, district general hospital, nursing home or private residence. RESULTS: death certificates of 398 people who had been treated for AD PSD and 348 who had been treated for VaD were identified. Bronchopneumonia was the most common immediate cause of death in the AD PSD group (70.9%) but less so for the VaD group (51.7%). For both groups place of death was associated with significant differences in pneumonia being reported as the immediate cause of death as well as specific underlying and contributory causes of death. Dementia was recorded for 90.5% of AD PSD patients but for only 49.7% of the VaD group. CONCLUSIONS: Scottish death certificate data significantly underestimate the prevalence of presenile VaD. Changes in patterns of institutional care may affect dementia rates estimated from death certificate data.

Aged↗

PubMed2001

Cutaneous manifestations in HIV positive patients.

Cutaneous manifestations are common clinical findings among HIV positive patients. The causes may be bacteria, viruses, fungi and other non-infectious agents. This study was conducted at the Pramongkutklao Hospital skin clinic to determine the frequency distribution of cutaneous manifestations in HIV positive patients. A total of 147 patients with HIV seropositivity were recruited and divided into a retrospective group and a prospective study group. For the retrospective study, hospital records of 129 patients who attended from January 1995 to November 1998 were recruited. The prospective study was carried out from November 1998 to January 1999 and 18 patients were recruited. Cutaneous finding among patients in the two studies were evaluated. There were ten common cutaneous manifestations observed in the retrospective and prospective study including pruritic papular eruptions (PPE) (51.2%, 50%), oral candidiasis (16.7%, 21.7%), herpes zoster (10.9%, 5.6%), oral hairy leukoplakia (10%, 5.6%), unclassified eczema (9%, 11.1%), urticaria (5.6%, 3.1%), seborrheic dermatitis (4.7%, 16.7%), folliculitis (4.7%, 5.6%), prurigo simplex (4.7%, 5.6%), and Steven-Johnson syndrome (3.9%, 0%). However, the distribution of cutaneous manifestations in the two studies were not significantly different. These findings may be useful as baseline data for common cutaneous manifestations in HIV positive patients.

AIDS-Related Opportunistic Infections↗

PubMed2006

Count data in psychological applied research.

As some authors have noticed in fields other than psychology, level of measurement and distributional characteristics of count data are commonly not taken into account, so that they are analysed as normally distributed continuous variables, and therefore some general linear model is applied. In this work, we review a random sample of 457 articles published in the last four years in journals with the highest impact factor in the Journal Citation Reports (JCR Social Sciences Edition) of the Institute for Scientific Information. The goals are to know how often count variables appear in psychological applied research and which data analyses are used when dealing with count response variables. Examination showed that there is a notable presence of count variables, especially in some topics in psychology and a remarkable misapplication of the general linear model. One deals with causes and consequences of this approach to data analysis and suggests the use of specific models to analyse count data.

Humans↗

PubMedDate not supplied

[Is the functioning of our brain of an addictive nature?].

The concept of addiction is increasingly bound to a general model of heterogeneous and polymorphous dependences. In this paper we examine upstream what could found this universal addictive principle, asking the question of the neurobiological root of addictivity. In other words, is the root of our brain working in an addictive way? To answer affirmatively to this question we gather two sets of datas: firstly, the conditions of the brain addictivity and secondly, the brain mechanisms that suggest this kind of addictive working. These datas are common if we consider them one by one, but their synthesis in a bundle of heuristic clues could be interesting to examine and to submit to thought. The model we suggest proposes that the architecture of our brain and the type of functioning of our neurones, imply the presence of a natural addictive set of problems in all human beings, between a fight against cerebral background noise--a dysphoric source--and a stimulation need. Finally, considering some neurobiological data in the last five years, we propose a triangular model of the addict brain, that involves three associated systems: "arousal" system, "liking" system and "wanting" system. This model, supported by the sensation seeking one, will allow us to suggest an explanation of the processes that lead to pathological addictions, according to the principles of a natural and universal addictivity.

Arousal↗

PubMed1997

Modelling repeated-series longitudinal data.

We present a model for describing repeated-series longitudinal data, that is, longitudinal data where each unit may yield multiple series of the same variable. Such data arise commonly in ophthalmologic studies, where one obtains measurements on the same variable for the right and left eyes at each clinic visit. We model the mean as a linear function of predictors, and assume that the error term is a sum of a random subject effect and a vector AR(1) process. We fit the model by maximum likelihood and assess the adequacy of the error assumptions by an extension of the empirical semivariogram. We apply our model for data from a clinical trial comparing two treatments for ocular hypertension and glaucoma, with intra-ocular pressure as the primary endpoint. Results suggest that autocorrelation within and between eyes is a significant feature of the variance model. Standard errors depend critically on the variance assumption.

Algorithms↗

PubMed2005

Software agents in molecular computational biology.

Progress made in applying agent systems to molecular computational biology is reviewed and strategies by which to exploit agent technology to greater advantage are investigated. Communities of software agents could play an important role in helping genome scientists design reagents for future research. The advent of genome sequencing in cattle and swine increases the complexity of data analysis required to conduct research in livestock genomics. Databases are always expanding and semantic differences among data are common. Agent platforms have been developed to deal with generic issues such as agent communication, life cycle management and advertisement of services (white and yellow pages). This frees computational biologists from the drudgery of having to re-invent the wheel on these common chores, giving them more time to focus on biology and bioinformatics. Agent platforms that comply with the Foundation for Intelligent Physical Agents (FIPA) standards are able to interoperate. In other words, agents developed on different platforms can communicate and cooperate with one another if domain-specific higher-level communication protocol details are agreed upon between different agent developers. Many software agent platforms are peer-to-peer, which means that even if some of the agents and data repositories are temporarily unavailable, a subset of the goals of the system can still be met. Past use of software agents in bioinformatics indicates that an agent approach should prove fruitful. Examination of current problems in bioinformatics indicates that existing agent platforms should be adaptable to novel situations.

Algorithms↗

PubMed1988

Impact of pregnancy on complications of insulin-dependent diabetes mellitus.

The effects of pregnancy on acute metabolic complications of diabetes may have important consequences for both mother and fetus. The consequences of pregnancy for chronic complications of diabetes, including retinopathy, nephropathy, neuropathy, and hypertension, are not clear. Recent data are reviewed so that health care providers will be able to provide reasonable advice to insulin-dependent diabetic women contemplating pregnancy both for problems that may potentially arise during gestation and those that may affect long-term health and survival. Diabetic ketoacidosis is an uncommon problem that arises during gestation. Acute alterations in pH and electrolyte concentrations as well as hyperglycemia, however, may have important consequences for mother and fetus, including perinatal asphyxia and reduced fetal oxygen delivery. Hypoglycemia, on the other hand, may result in maternal coma or seizures and, when frequent, has been associated with infant respiratory distress syndrome. Background retinopathy often worsens during gestation, with regression common postpartum. Data suggest that progression of background disease is related to both glycemic control and the acute institution of intensive insulin therapy with those patients with poor control requiring more aggressive therapeutic intervention most adversely affected. The course of proliferative retinopathy is more variable, with both progression and regression reported. Preconception photocoagulation may prevent progression. Preconceptional ophthalmologic evaluation with frequent assessments during pregnancy is advised. Increases in 24-hour protein excretion are common during gestation in patients with preexisting renal disease and resolve in many patients postpartum. Serum creatinine and creatinine clearance increase during the first trimester and generally do not change during the remainder of pregnancy.(ABSTRACT TRUNCATED AT 250 WORDS)

Diabetes Mellitus, Type 1↗

PubMed2025

Hierarchical Multi-Label Classification With Gene-Environment Interactions in Disease Modeling.

In biomedical studies, gene-environment (G-E) interactions have been demonstrated to have important implications for analyzing disease outcomes beyond the main G and main E effects. Many approaches have been developed for G-E interaction analysis, yielding important findings. However, hierarchical multi-label classification, which provides insightful information on disease outcomes, remains unexplored in G-E analysis literature. Moreover, unlabeled data are commonly observed in practical settings but omitted by many existing methods of hierarchical multi-label classification. In this study, we consider a semi-supervised scenario and develop a novel approach for the two-layer hierarchical response with G-E interactions. A two-step penalized estimation is then proposed using an efficient expectation-maximization (EM) algorithm. Simulation shows that it has superior performance in classification and feature selection. The analysis of The Cancer Genome Atlas (TCGA) data on lung cancer demonstrates the practical utility of the proposed method. Overall, this study can fill the important knowledge gap in G-E interaction analysis by providing a widely applicable framework for hierarchical multi-label classification of complex disease outcomes.

Humans↗

PubMed2005

Statistical considerations for immunohistochemistry panel development after gene expression profiling of human cancers.

In recent years there have been a number of microarray expression studies in which different types of tumors were classified by identifying a panel of differentially expressed genes. Immunohistochemistry is a practical and robust method for extending gene expression data to common pathological specimens with the advantage of being applicable to paraffin-embedded tissues. However, the number of assays required for successful immunohistochemical classification remains unclear. We propose a simulation-based method for assessing sample size for an immunohistochemistry investigation after a promising gene expression study of human tumors. The goals of such an immunohistochemistry study would be to develop and validate a marker panel that yields improved prognostic classification of cancer patients. We demonstrate how the preliminary gene expression data, coupled with certain realistic assumptions, can be used to estimate the number of immunohistochemical assays required for development. These assumptions are more tenable than alternative assumptions that would be required for crude analytic sample size calculations and that may yield underpowered and inefficient studies. We applied our methods to the design of an immunohistochemistry study for glioma classification and estimated the number of assays required to ensure satisfactory technical and prognostic validation. Simulation approaches for computing power and sample size that are based on existing gene expression data provide a powerful tool for efficient design of follow-up genomic studies.

Computer Simulation↗

PubMed2003

Connectivity analysis with structural equation modelling: an example of the effects of voxel selection.

Structural equation modelling (SEM) of neuroimaging data is commonly applied to a network of distributed brain regions. We applied SEM to an fMRI dataset to identify condition-specific effects in a simple experiment composed of visual stimulation and baseline conditions. The visual network was composed of three well-defined anatomical regions (V1, V2, and V5) and three path connections (V1 --> V2, V1 --> V5, and V2 --> V5). This network was used to test four hypotheses: (1) whether the condition-specific effects for all three connections vary according to the data selected for modelling; (2) whether the "summary" measures that are often used are indeed appropriate; (3) whether measures taken from the voxel timecourse can reliably predict the condition-specific effects for each one of the three path connections, and (4) whether all voxels within an anatomical region yield equivalent SEM outcomes. There was some variability in the significance of the condition-specific effects across randomly selected voxels within regions. However, the SEM outcome from the "summary" measures was comparable to the most frequent pattern of condition-specific effects. Magnitude, delay, spread, and goodness-of-fit measures taken from a gamma fit to the voxel time courses predicted reliably the significance of the SEM condition-specific effects for each connection. This result enabled us to identify spatially coherent regions at the boundaries of V2 that displayed different condition-specific effects from those seen in the majority of the voxels. Although the generality of these results awaits further investigation, this example highlights a number of important issues for SEM. We have provided further evidence that the SEM outcome does vary somewhat according to the voxels selected and that, although the use of summary measures can give a generalised view of the connectivity pattern, they could fail to capture functional differences within specialised areas.

Adult↗

PubMed1995

Fitting the two-stage clonal expansion model based on exact hazard to the ED01 data using SAS NLIN.

The two-stage clonal expansion model is a popular model for carcinogenesis data. One common form of this model is based on the approximate hazard function. In certain situations, this formulation is not appropriate, and the exact hazard should be applied. However, the difficulty of implementing the model based on the exact hazard has deterred many from using it. This paper presents a program implementing the exact hazard model for piecewise constant dosing using SAS, a package that is readily available to most that are interested in this type of analysis. Also, an analysis of the ED01 data is presented using this program, and comparisons are made to an earlier analysis based on the approximate hazard. By allowing for an independent background tumor mechanism, an excellent fit to the bladder tumor incidence data was obtained.

Algorithms↗

PubMed1992

Work related upper limb disorder: the relationship between pain, cumulative load, disability, and psychological factors.

Repetitive strain injury, or work related upper limb disorder, provides an interesting paradigm for the study of the relative contribution of physical and psychological factors to the resulting pain and disability. Sixty three subjects were studied, comprising the work-force of a subsection of a large local industrial company, in whom pain in the arm related to work was known to be common. Ergonomic data were obtained by estimating the cumulative daily load on the wrist joint for each of four identified tasks. Data on the occurrence of pain, treatment sought, and disability were obtained by a structured self administered questionnaire. Psychological data were obtained by administering the Hospital Anxiety and Depression (HAD) scale, a self reported measure of anxiety and depression, and the Bradford Somatic Inventory (BSI), an inventory of somatic symptoms associated with anxiety and depression. The employment specific period prevalence of work related upper limb disorder was 81%, with 30% of the subjects having pain at the time of the study. Domestic disability was minimal in all but two subjects, though the use of devices such as jar openers at home was common (12 of 51 subjects). Medical advice was seldom sought. Twenty per cent of subjects had received anti-inflammatory drugs, 10% had received physiotherapy, and 47% had wrist splints. Pain was related to the tasks with the highest estimated daily loads, but a history of pain and current pain were associated with higher scores on the HAD and BSI scales, suggesting an interaction between physical and psychological factors.

Adolescent↗

PubMed2005

Management options for bipolar disorder in children and adolescents.

During recent years there has been a dramatic increase in the use of psychotropic medication for the treatment of bipolar disorder (BPD) in children. There is an emerging set of data to support this use.Mood stabilizers, including lithium and valproic acid (valproate sodium), have generally formed the mainstay of treatment in children and adolescents with BPD. However, the atypical antipsychotics, such as risperidone, aripiprazole, and quetiapine may be more effective as first-line treatment options and in some ways easier to use than the traditional mood stabilizers. As in adults, mood stabilization is often difficult to achieve in pediatric patients with BPD, and combined treatment with mood stabilizers and atypical antipscyhotics is commonly used. Data from controlled trials of psychotropic medications in children and adolescents with BPD are very limited, and hence, in the majority of cases physicians base their treatment decisions on data from case reports, case series, or open trials. More controlled studies of both monotherapy and polypharmacotherapy for BPD in children and adolescents are needed.

Adolescent↗

PubMed2001

Chronic hyperlactatemia in HIV-infected patients taking antiretroviral therapy.

OBJECTIVE: To determine the prevalence, course and risk factors for hyperlactatemia in HIV-infected patients. DESIGN: A prospective, longitudinal study of venous lactate concentrations over an 18-month period in 349 participants of the Western Australian HIV Cohort Study. RESULTS: In 516 patient-years of observation, two patients experienced severe fulminant lactic acidosis (lactate > 5 mmol/l) and hepatic steatosis attributable to nucleoside analogue reverse transcriptase inhibitors (NRTI). A further five patients with lesser elevations of lactate (2.8-4.1 mmol/l) but with symptoms of nausea or abdominal discomfort and evidence of hepatic steatosis had NRTI therapy revised, with relief of symptoms and a fall in lactate levels. Most remaining patients on highly active antiretroviral therapy (HAART) had mild, chronic, asymptomatic hyperlactatemia, with mean lactate level between 1.5 mmol/l and 3.5 mmol/l most commonly. Longitudinal data was analysed in a non-linear mixed effects growth model which indicated that average lactate levels rose after the start of HAART but tended to stabilise at low-grade elevation, with an average 0.23 mmol/l greater long term level in stavudine users compared with zidovudine users (p < 0.01). A multiple linear regression model showed that the association between stavudine and higher lactate level was not confounded by longer duration of total NRTI exposure. Risk of hyperlactatemia was not significantly associated with use of other NRTIs, protease inhibitors, non-nucleoside analogue reverse transcriptase inhibitors or multiple immunological and virological factors in multivariate analyses. CONCLUSIONS: Chronic, compensated, asymptomatic hyperlactatemia is common in patients taking HAART. Decompensated, life-threatening lactic acidosis/hepatic steatosis is rare. Treatment with stavudine appears to be the predominant risk factor for development of chronic hyperlactatemia.

Acidosis, Lactic↗