SEARCH · PubMed Health

Results for “Model explainability”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,639 records · Page 91Linked to original sources

PubMed2001

GnRH pulsality and the differential activation of the rat luteinizing hormone subunit genes in the anterior pituitary gland.

Detailed studies have been focused on the mechanisms by which the rat alpha and LHbeta genes are differentially regulated by GnRH and indicate that differential sensitivity to the second messenger exists in a physiological context. Differential signaling from the GnRH receptor may be a mechanism for preferential regulation of luteinizing hormone subunit gene transcription; however which of these genes are specifically regulated by PKC or calcium and how GnRH pulsatility could preferentially activate individual pathways of second messengers within gonadotrope cells remain unclear. Several transcription factors that have profound effects on basal and/or GnRH-stimulated LHbeta gene promoter activity have been identified: SF-1, Egr-1, Sp-1. A model explaining possible interactions among them in mediating GnRH responsiveness of the LHbeta gene has been proposed: Sp1, SF-1 and Egr-1 form a tripartite GnRH response element which is sensitive to the spacing changes between the upstream Sp1 binding sites and the downstream SF-1/Egr-1 binding elements and SF-1 plays a critical role in integrating the effects of Sp1 and Egr-1. GnRH responsive element located on LHbeta gene promoter in position between -495 to -342 has been identified. At 3'-end of the promoter three Sp-1 binding sites have been identified: position -416, sequence: GGGGGCTGGG and two sites almost completely overlapping, position -403, sequence; GGGGCGGCGCCCA while at the 5'region of the promoter one Sp-1 binding site exists: position -450, sequence: ACCACACCCATTTTTGG. The 5'Sp1 site overlaps a CArG box (at -443 to -434, sequence: CCATTTTTGG) which seems to be essential in LHbeta gene sensitivity for pulsatile GnRH stimulation.

Animals↗

PubMed2002

Relationship style between GPs and community mental health teams affects referral rates.

BACKGROUND: Community mental health teams (CMHTs) are the established model for supporting patients with serious mental illness in the community. However, up to 25% of those with psychotic disorders are managed solely by primary care teams. Effective management depends upon locally negotiated referral and shared care arrangements between CMHTs and primary care. AIM: To examine whether the style of working relationship between general practices and CMHTs affects the numbers and types of referrals from general practices to CMHTs, taking into account population and practice factors and provision of other mental health services which may influence referral rates. DESIGN OF STUDY: Cross-sectional study. SETTING: All 161 general practices in East London and the City Health Authority. METHOD: Questionnaire survey to all general practices to identify style of relationship. Collection of routinely available referral data to all statutory mental health services over a two-year period. Main outcome measures were number and types of referrals from general practices to CMHTs. RESULTS: The average annual referral rate to the eleven CMHTs in east London is 10 per 1000 adult population annually. The teams show a sixfold variation in rates of referral from all sources. Where good working relationships (a consultation-liaison style) exist between CMHTs and general practice, there are greater numbers of referrals requiring both long and short-term work by CMHTs. Two-stage multivariate models explained 47% of the referral variation between practices. Where primary care-based psychologists work with practices there are greater numbers of CMHT referrals, but less use of psychiatric services. CONCLUSION: Shifting to a consultation-liaison relationship should increase rates of referral of patients with serious mental illness, including those who can most benefit from the skills of CMHTs. Increasing the provision of primary care-based psychology might improve practice use of mental health services, reducing avoidable outpatient psychiatric referrals.

Adolescent↗

PubMedDate not supplied

[The role of the basal ganglia in monitorization of frontal lobe function].

OBJECTIVE: To review current understanding of the mechanisms controlling the activity of the frontal lobes and consider simple explanations of hypotheses regarding this. DEVELOPMENT: We describe the basic functional anatomy of the frontal cortex and its relation to the basal ganglia by means of five parallel fronto subcortical circuits (motor, oculomotor, dorsolateral, orbitofrontal and anterior cingulate. From the functional point of view we emphasize that the frontal cortex can keep certain zones active in relation to relevant tasks, and can be very flexible. These properties form the so called anterior attention system. We describe various recent models explaining frontal cortical activity in these terms, and emphasize those based on fronto subcortical circuits. These circuits control motor, cognitive, social and emotional behaviour. CONCLUSIONS: The cortical activity of the frontal lobes is regulated by various parallel, segregated fronto subcortical circuits. These circuits permit the selection and maintenance of activity of particular cortical regions regarding relevant conduct, whilst irrelevant conduct is inhibited. In this way they constitute the basic functional mechanism of the attention system described above. For prediction of the relevance or irrelevance of the consequences of each new stimulus, the anterior cingulate cortex probably establishes comparisons with previous situations which have already been stored together with certain somatic markers which indicate their emotional significance for the organism. This cortex fulfils the anatomical conditions necessary for regulation of the activity of the basal ganglia together with the whole frontal cortex so as to permit behaviour which is orderly from the time aspect.

Basal Ganglia↗

PubMed2002

Equity in waiting times for major joint arthroplasty.

OBJECTIVE: To ascertain whether waiting lists are managed in an equitable fashion in a universal health system by examining demographic, socioeconomic and clinical factors, along with 2 health systems variables. DESIGN: A prospective survey by questionnaire. SETTING: The Capital Health Region of Edmonton, Alta. PATIENTS AND METHODS: A cohort of 553 patients, who were waiting for either total hip or total knee replacement surgery, seen between Dec. 18, 1995, and Jan. 24, 1997. INTERVENTIONS: A home visit was made when the patient was first placed on the waiting list and again just before surgery to complete the questionnaires. The Western Ontario and McMaster Universities (WOMAC) instrument and the Medication Quantification Score were administered at the time the patient was placed on the waiting list. MAIN OUTCOME MEASURE: The length of waiting time, defined as the date the patient was put on the waiting list to the date the patient was operated on. RESULTS: There were no biases in waiting time with respect to age, gender, education or work status. Although pain and function were not related to waiting time, multivariate analyses found that marital status, primary language, body mass index, pain medication use and the size of the surgeons' major joint replacement practice determined waiting time for surgery. However, this model explained only 10% of the variance in waiting time. CONCLUSION: Waiting lists were managed unfairly in terms of clinical equity (clinical severity) but managed fairly in terms of social equity.

Aged↗

PubMed2002

[Naltrexone use in the treatment of alcoholism in Spain].

To analyse the causes that prompted health care professionals to select naltrexone to treat alcoholism. One-year multicentric, prospective study conducted with 221 doctors specialized in alcoholism treatment and analysis of data derived from 1,396 patients attended. Naltrexone was not prescribed to 446 patients. The medical barriers to the prescription of naltrexone included the mode of understanding alcoholism by doctors (20 % of doctors), patients reluctance to take naltrexone (26.9 % of patients), the presence of a concomitant condition (27.6 %) and barriers associated with health care system (6 % of patients). The logistic regression model explained why doctors tended not to prescribe naltrexone when patients had a long course of their disease or had previously received acamprosate.

Adult↗

PubMed2002

A longitudinal causal relationship among cardiovascular risk factors in the employees of the government savings bank.

A longitudinal structural causal model was generated to examine the causal relationship among determinants which were composed of four personal factors, stress, four health behaviors, and BMI on five physiological risks for cardiovascular disease: SBP, DBP, FBS, TC and HDL-C in 1,019 bank employees, within a five-year interval. A fourteen-item food frequency questionnaire for assessing eating habits and the Health Opinion Survey for the stress test were included in the self-administered questionnaires. Weight, height and blood pressure were measured and blood samples were collected for blood chemical analysis. Data analysis by LISREL showed that the determinants in the proposed model explained as much as 96 per cent variation in physiological risks for CVD (R2 = 0.96, relative chi-square = 1.92, RMSEA = 0.03, GFI = 0.96 and AGFI = 0.95). The findings also indicated that current physiological status was affected by their status of age, education, health behaviors, BMI and physiological status 5 years ago.

Adult↗

PubMed2003

A geographic sampling strategy for studying relationships between human activity and malaria vectors in urban Africa.

This paper describes a geographic sampling strategy for ecologic studies and describes the relationship between human activities and anopheline larval ecology in urban areas. Kisumu and Malindi, Kenya were mapped using global positioning systems, and a geographic information system was used to overlay a measured grid, which served as a sampling frame. Grid cells were stratified and randomly selected according to levels of planning and drainage. A cross-sectional survey was conducted in April and May 2001 to collect entomologic and human ecologic data. Multivariate regression analysis was used to test the relationship between the abundance of potential larval habitats, and house density, socioeconomic status, and planning and drainage. In Kisumu, 98 aquatic habitats were identified, 65% of which were human made and 39% were positive for anopheline larvae. In Malindi, 91 aquatic habitats were identified, of which, 93% were human made and 65% were harboring anopheline larvae. The regression model explains 82% of the variance associated with the abundance of potential larval habitats in Kisumu. In Malindi, 59% of the variance was explained. As the number of households increased, the number of larval habitats increased correspondingly to a point. Beyond a critical threshold, the density of households appeared to suppress the development of aquatic habitats. The proportion of high-income households and the planning and drainage variables tested insignificant in both locations. The integration of social and biologic sciences will allow local mosquito and malaria control groups an opportunity to assess the risk of encountering potentially infectious mosquitoes in a given area, and concentrate resources accordingly.

Africa↗

PubMed2003

Factors associated with body function and disability in patients with ankylosing spondylitis: a cross-sectional study.

OBJECTIVE: To determine for patients with ankylosing spondylitis (AS) which factors are associated with disability and restricted body function. METHODS: In 1538 patients with AS, occiput-to-wall distance, chest expansion, cervical rotation, finger-floor distance, and modified Schober test were measured cross-sectionally, and for each measure the patient's respective percentile was calculated. The mean of the 5 percentiles was summarized in the mobility restriction score (MRS). In addition, patients answered questions on disease progression and completed the Bath AS Functional Index (BASFI) questionnaire. All data were coded into 40 variables, used as independent variables in multiple regression analyses to identify factors associated with BASFI and MRS. RESULTS: Finger-to-floor distance (beta positive, +), cervical rotation (-), time since first AS symptoms (-), age (+), height loss (+), maximum height (-), delay in diagnosis (+), hip replacement (+), regular practice of sports (-), chest expansion (-), sex (worse BASFI in females), exposure to cold and dampness (+), and regular participation in AS group physical exercises (+) were significantly associated with worse BASFI. Significantly associated factors for worse MRS were height loss (+), sex (higher MRS in males), active inflammation of the cervical region (+), age (+), maximum height (-), active inflammation of the hip region (+), involvement of shoulders (+), time since first AS symptoms (+), urethritis (-), regular practice of sports (-), involvement of feet (-), and hip replacement (+). The models explain 47% of the variance observed for both the BASFI and MRS. CONCLUSION: The amount of variance explained for both BASFI and MRS is rather high. The results apply primarily to groups of patients, but are insufficient to guide clinical decisions in individual patients. These findings contribute to our understanding of factors influencing disability and restriction in body function in AS.

Adolescent↗

PubMedDate not supplied

SARS infection control in Taiwan: investigation of nurses' professional obligation.

This exploratory, cross-sectional, quantitative study investigated the relationship among hospital nurses' willingness to provide care for severe acute respiratory syndrome (SARS) patients, their attitudes toward SARS infection control measures, and nurses' health status and demographic characteristics. This project was conducted from May 6 to 12, 2003. A total of 126 nurses working in hospitals participated in this study. A conceptual model was developed, and the author designed a questionnaire to test this model. The developed model explained 32% of the variance in nurses' willingness to provide care for SARS patients. Nurses' levels of agreement with general SARS infection control measures, self-treatment of relief of fever and cough, necessity to close Hoping and Jenchi hospitals, nurses' physical health status, and holding a bachelor's degree were statistically significant predictors of nurses' willingness to care for SARS patients. Based on these findings, suggestions and study limitations are discussed.

Adult↗

PubMed2003

Relationships of perceived benefits and barriers to physical activity, physical activity participation and physical fitness in Hong Kong female adolescents.

AIM: Previous studies that examined participation in physical activity suggested that female adolescents were less active compared with males. However, the relationship between physical fitness, physical activity participation, and perceived benefits and barriers for physical activity to adolescents, irrespective of gender, has not been made clear. This study examines the association of these factors in female adolescents. METHODS: Physical activity participation and perceived benefits and barriers to physical activity were determined in 206 secondary school female subjects (aged 11 to 18) using a validated questionnaire. RESULTS: Subjects with a correct concept about optimal physical activity participation to maintain health engaged in an activity level higher than the group without a correct concept (t=2.37, p=0.02). A significant correlation was established between the physical activity participation with "health" (r=0.22, p<0.001) and "body image" (r=0.17, p=0.02) in the perceived benefit category. The individual factor, "make me feel better in general" in the "health" category (p=0.04) and the intention to participate (p<0.001) were shown to be significant predictors for physical activity participation. The combined effects of the regression model explained 35.9% of the variance in participation in physical activity. CONCLUSION: Policies to support regular physical activity participation at school and out-of-school should be strategically developed and promoted, highlighting the promotion of health benefits in exercise and the reinforcement of initial intent towards exercise.

Adolescent↗

PubMedDate not supplied

[The possibilities of neurocognitive rehabilitation in schizophrenia].

INTRODUCTION: Schizophrenia is a severely disability causing syndrome, what tend to chronically alter living project of great number of young people and its families. It is affected multiple cognitive functions, as executive capacity, explicit memory, working memory or perceptive integration. In the last years, neurocognitive rehabilitation techniques of this functions coming from the experience with brain damage patients has been applied to schizophrenia. DEVELOPMENT: Present work revised: a). cognitive deficits that can be considered as nuclear in the genesis of schizophrenia symptoms and b). recovery or substitution strategies of that deficits, that can be generalized to a better psychosocial functioning of the patient. It is proposed that attention control deficit (ACD), defined as the inadequate assignation of attention recourses during cognitive processing, results in attention processing of redundant information and a lack of attention recourses to process new information. Some explaining models are presented for subjective and perceptive symptoms, language disorders and executive disorders in schizophrenia. Possibilities of neurocognitive rehabilitation in schizophrenia are discussed, especially by the utilisation of implicit learning methods, that don't need attention processing. Some recommendations are made for the implementation of cognitive rehabilitation in the general framework of psychosocial and occupational rehabilitation.

Attention↗

PubMed2004

Current concepts in urinary tract infections.

Urinary tract infections (UTIs) are common infectious diseases that can be associated with substantial morbidity and significant expenditures. This review highlights the current concepts and recent advances in our understanding and management of this condition. Specific topics include pathogenesis, host factors, antimicrobial resistance, recurrent UTIs in women, diagnosis, treatment of uncomplicated and complicated UTIs, prophylaxis, catheter associated bacteriuria, pregnancy, diabetes, UTIs in men, prostatitis, and the chronic pelvic pain syndrome. UTIs can be viewed as an interaction between specific bacterial virulence factors and the patient. A new model explaining the pathogenesis of recurrent UTIs has been presented. There is a need to reconsider traditional treatment recommendations in the face of local resistance patterns, as well as the need to make better use of drugs that are currently available. Prospects for prevention of recurrent UTI include natural compounds, bacterial interference and immunization. With regard to UTI risk in women, patients can be classified based on age, and functional and hormonal status. Appropriate treatment approaches must be based on this classification. In contrast to uncomplicated UTIs, management of most complicated infections depends on clinical experience and resources at individual institutions rather than on evidence based guidelines. Asymptomatic bacteriuria generally should not be treated except in high-risk catheterized patients and in pregnancy. UTIs in men generally require formal urologic evaluation. Our understanding of the etiologies, diagnostic strategies, and treatment options for prostatitis and the chronic pelvic pain syndrome in men continues to evolve.

Abscess↗

PubMed1992

[What does the higher concentration of general practitioners mean for fee-for-service reimbursement].

The density of general practitioners has increased steadily in Norway. By the end of 1989, there were 1,339 inhabitants per general practitioner. General practitioners are partly remunerated per item of service, i.e., by reimbursement from the National Insurance Fund and partly by patient co-payment. The article analyses the connection between density of general practitioner and level of fee-for-service reimbursement. The average general practitioner received about 60% higher fee-for-service reimbursement in 1989 than in 1985. This increase is markedly higher than the nominal changes in the tariff. The increase was somewhat higher in areas with a relatively low density of general practitioners. Also, in each of the years 1985-1989, the average fee-for-service reimbursement was slightly higher in areas with a low density of general practitioners. The variations have only a slight impact on the gross revenues of general practitioners. Three models explaining the use of general medical services are outlined. The results can be interpreted in the light of changes in health, changes in health-related behaviour, and supplier-induced demand. Since only aggregate data are available, it is difficult to further explore possible explanations.

Fees, Medical↗

PubMed1992

Drastic differences in glycosylation of related S-layer glycoproteins from moderate and extreme halophiles.

The outer surface of the moderate halophilic archaebacterium Haloferax volcanii (formerly named Halobacterium volcanii) is covered with a hexagonally packed surface (S) layer glycoprotein. The polypeptide (794 amino acid residues) contains 7 N-glycosylation sites. Four of these sites were isolated as glycopeptides and the structure of one of the corresponding saccharides was determined. Oligosaccharides consisting of beta-1,4-linked glucose residues are attached to the protein via the linkage unit asparaginyl-glucose. In the related glycoprotein from the extreme halophile Halobacterium halobium, the glucose residues are replaced by sulfated glucuronic acid residues, causing a drastic increase in surface charge density. This is discussed in terms of a recent model explaining the stability of halophilic proteins.

Amino Acid Sequence↗

PubMed2005

Periodontal disease -- the emergence of a risk for systemic conditions: pre-term low birth weight.

This paper addresses the problem of adverse pregnancy outcome in relation to periodontal disease. There is compelling evidence that a link exists between pre-term low birth weight (PLBW) and periodontitis. Although 25% to 50% of PLBW deliveries occur without any known aetiology, there is increasing evidence that infection may play a significant role in pre-term delivery. A model explaining the plausible relationship is proposed based upon the concept of infection leading to a cascade of inflammatory reactions associated with pre-term labour and periodontal disease. Current evidence has pointed to an interest in dental intervention studies to control periodontal disease as one of the potential strategies to reduce pre-term labour. This paper reviews the potential association between periodontal infection and adverse pregnancy outcomes.

Animals↗

PubMed2005

[The social deficit in autism: focus on joint attention].

INTRODUCTION AND DEVELOPMENT: Autism is best thought of as a spectrum disorder with the dimensional components of social cognition, communication and flexibility varying between individuals meeting the criteria of autism. The core clinical feature that defines autism is a disturbance in social interaction which is not absolute and differs depending on a child's cognitive level, developmental stage, and the type of social structure in which they are observed. Social skills are under strong genetic influence with a continuous distribution of social interaction deficits in the general population with arbitrary cutoffs defining who is and is not affected with an autism spectrum disorder; this is the result of a complex interplay between numerous biological and environmental factors. Joint attention refers to the capacity of individuals to coordinate attention with a social partner in relation to some object or event and a disturbance in this early skill and in particular impairment in the ability to initiate joint attention, is a central symptom of autism. CONCLUSIONS: There are data to suggest that dorso-medial frontal cortex and anterior cingulate contribute to the development of an infant's ability to maintain representations of self, a social partner and an interesting object. The ability to engage frequently in social orienting behaviors and ultimately in numerous episodes of social attention coordination, or joint attention, may be a critical experience during a particular developmental window that serves to organize social neurodevelopment. A neurodevelopmental model explaining how these early deficits in social cognition may lead to autism is reviewed.

Autistic Disorder↗

PubMed2005

Indicators predicting use of mental health services in Piedmont, Italy.

BACKGROUND: Since the 1978 Italian reform, an integrated network of community mental health services has been introduced. With few exceptions, research on determinants of mental health service use at the district level has focused on inpatient activities and social deprivation indicators. The European Psychiatric Care Assessment Team (EPCAT) standardized methodology allows for an evidence-based comparison of mental health systems between geographical areas. AIMS: To compare service provision and utilization between local catchment areas; to explore quantitative relationships between residential and community service use and socio-demographic indicators at the ecological level. METHODS: The European Socio-demographic Schedule (ESDS) was used to describe area characteristics, and the European Service Mapping Schedule (ESMS) to measure service provision and utilization in 18 catchment areas in Piedmont. RESULTS: Substantial variation in service use emerged. Acute hospital bed occupancy rates were lower in areas with more intensive community continuing care service users and with a smaller percentage of the population living alone. The non-acute hospital bed occupancy rate was directly related to the percentage of the population living alone or in overcrowded conditions, and to the level of mobile continuing care service users. Community continuing care service use was highest in areas with a larger percentage of the population living alone. DISCUSSION: Multiple regression models explained between 48 and 55% of the variation in inpatient and community service use between areas. Relationships based on ecological characteristics do not necessarily apply to the individual. This level of assessment, however, is necessary in evaluating mental health policy and service systems, and in allocating resources. IMPLICATIONS FOR HEALTH CARE PROVISION AND USE: The distribution of mental health care resources should be weighted in terms of indicators of social deprivation shown to be important predictors of both inpatient and community service use, as these are likely to be related. IMPLICATIONS FOR HEALTH POLICIES: To ensure horizontal equity in access to mental health care, particularly for people with severe mental illness, evaluation of mental health policy should be based on a concurrent evidence-based assessment of the organization and use of both residential and community services, in relation to area level indicators of social deprivation. IMPLICATIONS FOR FURTHER RESEARCH: Cross-national research using an internationally standardized methodology should consider the influence of the social network independently of other socio-economic indicators, to verify the relative importance of this in predicting service use in southern and in northern European countries.

Catchment Area, Health↗

PubMedDate not supplied

Development of a functional disability measurement tool to assess early arthritis: the Recent-Onset Arthritis Disability (ROAD) questionnaire.

OBJECTIVE: To develop a self-administered questionnaire, the ROAD (Recent-Onset Arthritis Disability), to probe physical disability in Italian patients with early arthritis (EA) of less than one year's duration. METHODS: The development of the ROAD follows a series of major steps: (1) identification of a specific patient population, (2) item pool development, (3) item reduction, (4) internal consistency, (5) pre-testing of the prototype instrument, and (6) a validation study which results in determination, reliability, validity and responsiveness. In this study we have verified the first five steps. Pre-defined areas of disability were culled from eight existing Italian version arthritis-specific questionnaires, and three generic global health measurement tools. Semi-structured interviews helped to derive a 76-item pool from an initial group of 122 items. This questionnaire was administered to 78 EA patients. RESULTS: For scale generation, a combination of frequency importance product (FIP = frequency x mean relevance score) and factor analysis was applied. The top 20 items based on the FIP were then subjected to further analysis. Each question was correlated with every other question. This allowed us to eliminate 8 questions that were therefore highly correlated and were measuring the same concept. The final instrument has 12 items, representing a combination of symptoms that are common, frequently recurring and of general importance to EA patients. Factor analysis provides a 3-factor health status model explaining 70.1% of the variance. The upper extremity function (5 items) is loaded on the first factor, which explains 45.4% of the total measured variance. The lower extremity function (4 items) formed the second factor (14.2% of the total variance). The third factor was determined by activities of daily living/work (3 items) and explain 10.5% of the total variance. The score of the different subscales can be presented graphically as a ROAD profile. CONCLUSION: Using a traditional development strategy, we have constructed a self-administered instrument for measuring physical functioning in patients with EA. The next stage includes reliability, validity and responsiveness testing of the 12-item questionnaire.

Activities of Daily Living↗