Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “data accessibility”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

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

At least 1,081 records · Page 60Linked to original sources
PubMed2003

The structure of bovine lysosomal alpha-mannosidase suggests a novel mechanism for low-pH activation.

Lysosomal alpha-mannosidase (LAM: EC 3.2.1.24) belongs to the sequence-based glycoside hydrolase family 38 (GH38). Two other mammalian GH38 members, Golgi alpha-mannosidase II (GIIAM) and cytosolic alpha-mannosidase, are expressed in all tissues. In humans, cattle, cat and guinea pig, lack of lysosomal alpha-mannosidase activity causes the autosomal recessive disease alpha-mannosidosis. Here, we describe the three-dimensional structure of bovine lysosomal alpha-mannosidase (bLAM) at 2.7A resolution and confirm the solution state dimer by electron microscopy. We present the first structure of a mammalian GH38 enzyme that offers indications for the signal areas for mannose phosphorylation, suggests a previously undetected mechanism of low-pH activation and provides a template for further biochemical studies of the family 38 glycoside hydrolases as well as lysosomal transport. Furthermore, it provides a basis for understanding the human form of alpha-mannosidosis at the atomic level. The atomic coordinates and structure factors have been deposited in the Protein Data Bank (accession codes 1o7d and r1o7dsf).

Animals↗
PubMed1997

Association between hepatoblastoma and very low birth weight: a trend or a chance?

Hepatoblastoma, a malignant hepatic tumor in children, is thought to be an embryonal tumor resulting from developmental disturbances during organogenesis. Although factors that might be involved in the tumorigenesis have been suggested, an association between hepatoblastoma and the patient's birth weight has not been reported. We have accessed the data in the Japan Children's Cancer Registry and have analyzed patients' diagnoses and birth weights. During the 9 years from 1985 to 1993, 38 (0.38%) patients with tumors who weighted less than 1500 gm at birth were identified among 9923 registered patients. Hepatoblastoma was diagnosed in 9 patients of very low birth weight, representing 3.9% of the 231 patients with hepatoblastoma registered. A significant linear trend toward an increase in the percentage of patients with a birth weight of less than 1500 gm was observed specifically in hepatoblastoma (p = 0.0047). The percentage rose from 0.7% (1/138) in the 5-year period of 1985 to 1989 to 8.6% (8/93) in the next 4-year period (1990 to 1993). This increase was attributed to the significant increase in the percentage of patients who weighed less than 1000 gm at birth (p = 0.0028). A separate peak in the number of patients in the birth weight range of less than 1000 gm suggests that the cause of hepatoblastoma related to very low birth weight may be different from that of other patients. Full analysis of the patients' data is an urgent matter.

Birth Weight↗
PubMedDate not supplied

Spontaneous meal patterns in female rats with and without access to running wheels.

Rats display strong behavioral rhythms during the ovarian cycle. During estrus, food intake is minimal due to a decrease in meal size, and locomotor activity is maximal. To investigate how activity influences feeding patterns across the ovarian cycle, we used a computerized system to monitor spontaneous meal patterns in intact, cycling female rats with and without access to running wheels. We found that running wheel access decreased dark meal frequency, increased dark meal size, and increased 24-h water intake during each phase of the ovarian cycle. In contrast, body weight, 24-h food intake, and the ovarian rhythms of reduced food intake, meal size, and body weight during estrus were not affected by running wheel access. In particular, the reduction in food intake during estrus was due to a selective reduction in dark meal size, not dark meal frequency, and this occurred independent of wheel access. These data indicate that estrus-related changes in spontaneous meal patterns and locomotor activity are independently controlled and that the reduction in food intake during estrus involves a selective change in the neurobiological controls of meal size.

Animals↗
PubMed2003

Speaker verification using committee neural networks.

Security is a major problem in web based access or remote access to data bases. In the present study, the technique of committee neural networks was developed for speech based speaker verification. Speech data from the designated speaker and several imposters were obtained. Several parameters were extracted in the time and frequency domains, and fed to neural networks. Several neural networks were trained and the five best performing networks were recruited into the committee. The committee decision was based on majority voting of the member networks. The committee opinion was evaluated with further testing data. The committee correctly identified the designated speaker in (50 out of 50) 100% of the cases and rejected imposters in (150 out of 150) 100% of the cases. The committee decision was not unanimous in majority of the cases tested.

Algorithms↗
PubMed1985

Expansion of emergency medicine's responsibilities for preclinical education of medical students.

Many medical schools have required emergency medicine courses for freshmen medical students, usually through participation in BLS (basic life support) or EMT activities. For several years students at our institution have participated in a required emergency medical technician-ambulance grade (EMT-A) course. While retaining much of the material presented in that original EMT-A course, the course has now been expanded to serve as the medical students' introduction to clinical medicine. This expansion resulted from the belief that emergency medicine provides initial patient contact in the presence of a faculty uniquely suited to introduce the broad domain of clinical medicine to the medical student. Emergency physicians, more than any other specialists, must possess the ability to obtain an incisive history promptly, perform an accurate physical examination, and arrive at an assessment with limited laboratory and radiologic data. Initial access to the clinical education of medical students provides the opportunity to direct their efforts in a prioritized fashion, and thus helps to organize their thought processes for further development as clinicians. Departments of emergency medicine should be willing to accept this incremental responsibility for the introduction of the medical student to the clinical and laboratory assessment of patients.

Clinical Competence↗
PubMed2004

[Multilocus sequence typing: the molecular marker of the Internet era].

Global or longer term epidemiology track the spread of clonal lineages, associated with hipervirulence or resistance or multi-resistance to antimicrobial agents. Therefore, the application of a molecular typing system for this purpose should produce data easily shared by different and geographically distant laboratories, as well as distinguish those clonal lineages even with low levels of variability accumulated in the genome.A marker based on the DNA sequence will produce objective results easily organized in data bases accessible by Internet. The application of a similar strategy that was used in the analysis of isoenzymes, by sequencing variable fragments of selected housekeeping genes, will allow obtaining a general view of the distribution of the clonal lineages and tracking their spread.

Bacterial Infections↗
PubMed1998

Negotiating the new health system: purchasing publicly accountable managed care.

The transformation to managed care is one of the most important and complex changes ever to take place in the American health system. One key aspect of this transformation is its implications for public health policy and practice. Both public and private buyers purchase managed care; increasingly, public programs that used to act as their own insurers (i.e., Medicare, Medicaid and CHAMPUS) are purchasing large quantities of managed care insurance from private companies. The transformation to managed care is altering the manner in which public health policy makers conceive of and carry out public health activities (particularly activities that involve the provision of personal health services). The degree to which managed care changes public health and in turn is altered by public health will depend in great measure on the extent to which public and private policy makers understand the implications of their choices for various aspects of public health and take steps to address them. Because both publicly and privately managed care arrangements are relatively deregulated, much of the dialogue between public health and managed care purchasers can be expected to take place within the context of the large service agreements that are negotiated between buyers and sellers of managed care products. This is particularly true for Medicaid because of the importance of Medicaid coverage, payment and access policies to public health policy makers, and because of the public nature of the Medicaid contracting process. A nationwide study of Medicaid managed care contracts offers the first detailed analysis of the content and structure of managed care service agreements and the public health issues they raise. Four major findings emerge from a review of the contracts. First, most of the agreements fail to address key issues regarding which Medicaid-covered services and benefits are the contractor's responsibility and which remain the residual responsibility of the state agency. Second, most contracts fail to address the legal and structural issues arising from the relationship between the managed care service system and the public health system, including such key matters as access to care for communicable diseases and contractors' relationship to state public health laboratories. Third, many contracts are silent on health agencies' access to data for surveillance and community health measurement purposes. Finally, many contracts may be developed with only a limited understanding of the key public health-related issues facing the community from which the members will be drawn. The CDC and state and local public health agencies must expand their activities in the area of managed care contract specifications. For several years the CDC has been involved in an ongoing effort to develop quality of care measures to be collected from all companies through the HEDIS process. As important as this effort is, it represents only an attempt to measure what managed care does rather than an a priori effort to shape the underlying policy and organizational structure of managed care itself. Integrating managed care with public health policy will require this type of affirmative effort with both Medicaid agencies as well as other managed care purchasers.

Contract Services↗
PubMed2001

Identifying and using tools for reducing risks to patients and health care workers: a nursing perspective.

BACKGROUND: Research efforts and policy initiatives in health care errors and injury to health care workers have attracted increasing attention in recent years. An emerging theme in both these areas is the importance of organizational and other systems factors in the occurrence of medical error and health care worker injury. These commonalities call for the identification of common research efforts and, when appropriate, policy efforts. MOVING FROM HYPOTHESIS TO CONCLUSION: The proposition that health care error and worker injury are linked to the same organizational variables requires further research and deserves the same type of human factors approach that has characterized much of the investigative efforts that have occurred in the patient safety arena during the past decade. Serious problems exist with respect to access to data on staffing levels, skill mix, consecutive work hours, and other information that is crucial to examining the link between practice conditions, health care error, and health care worker injury. HUMAN FACTORS: One important resource in identifying effective approaches to prevent error and health care worker injury is the field of human factors, the discipline concerned with the design of tools, machines, and systems that takes into account human capabilities, limitations, and characteristics. CONCLUSION: The potential benefits of linking patient safety and health care worker safety efforts are significant. The research, experience, and successful practices from multiple disciplines must be utilized in identifying areas of common interest and concern in advancing work in both of these important areas.

Accidents, Occupational↗
PubMed1996

Do performance indicators make a difference?

BACKGROUND: The Maryland Hospital Association, Inc (MHA) Quality Indicator (QI) Project, a program of indicator development and application, includes more than 1,100 participating hospitals. Access to data is limited to participants to promote improvement through comparison across hospitals. Participating hospitals have identified and acted on opportunities for improvement in information systems, communication across departments and functions, processes of care, identification of appropriateness of practice, and improvement ¿beyond the hospital door¿. CASE STUDY 1: Two teams were formed to address waiting time in the emergency department and failure of patients to find treatment. Improvements, including rapid notification of available inpatient beds, additional staffing during high-census periods, and streamlined processes for lab work and imaging turnaround times, were followed by better indicator performance. CASE STUDY 2: A hospital discovered three causes for a high rate of unscheduled admissions following ambulatory surgery. Interventions included extending the hours of the Same Day Surgery Unit (to solve a urination problem) and changing the anesthesia used (to reduce nausea and vomiting). CASE STUDY 4: To successfully bring its cesarean section (C-section) rate down closer to the statewide rate, one hospital had physicians encourage patients with previous C-sections to undergo a trial of labor, promoted the use of epidural anesthesia, and took advantage of new packaging to facilitate the use of prostaglandin gel to induce cervical dilation. CONCLUSIONS: The QI Project continues to deal with issues concerning quality of data versus quality of care, the correlation between indicator rates and care processes, and the usefulness of severity adjustment.

Adult↗
PubMed1997

Preliminary evaluation of the effects of a nutrition awareness project on the Ngaanyatjarra Pitjantjatjara Yankunytjatjara communities of central Australia.

Preliminary observations from one nutrition awareness project--Approaches to Failure to Thrive--in progress in the Ngaanyatjarra Pitjantjatjara Yankunytjatjara region of central Australia are discussed, current strategies are listed and the need for multi-faceted solutions emphasised. A more rigorous quantitative evaluation is recommended, within the constraints of funding and access to data.

Australia↗
PubMed2005

Dishing the drugs: a qualitative study to explore paediatric nurses' attitudes and practice related to medication administration.

AIMS: The objectives of this study were to identify nurses' attitudes toward medication policies and the perceived factors that influence nurses' adherence to the medication policy or their ability to follow policy in the clinical environment of a tertiary paediatric hospital. METHODS: Using a focus group methodology, data were collated from a group of 32 nurses working in eight clinical areas of a tertiary paediatric hospital. Each discussion was transcribed and the data were subjected to a qualitatively based content analysis. RESULTS/FINDINGS: Four main categories emerged from the data including accessibility of information, time constraints, practice issues and professional conflict. CONCLUSIONS: Medication administration is a complex area of paediatric nursing practice. In an innovative attempt to assist in understanding nursing medication practice, this research has directly obtained nurses' perceptions of the factors that may influence their adherence to medication policy in the clinical environment. These results will inform future risk management strategies related to nursing medication practice.

Attitude of Health Personnel↗
PubMed2000

High-throughput gene expression analysis for drug discovery.

The ability to rapidly survey and compare gene expression levels between reference and test samples is moving the drug discovery process towards a more genomic orientation. The success of the Human Genome Project and related private genomics initiatives, combined with new technologies to probe, image and access expression data, are responsible for this transformation. This article reviews the history, status and future direction of high-throughput gene expression analysis. It describes classical approaches, explains the development of methods such as differential display for discovering novel genes, and discusses how microarray technology is exploiting collections of known sequences to pinpoint drug targets.

Journal Article↗
PubMed2001

Standardized terminological services enabling semantic interoperability between distributed and heterogeneous systems.

The interconnection of heterogeneous computer applications in medicine raises the issue of semantic interoperability, going beyond traditional approaches of terminological standardization in basically three aspects. First, the variety of medical vocabularies that currently coexist in different domains is a major barrier for the integration of autonomously developed applications. Fortunately, with the Unified Medical Language System (UMLS) there are machine-readable terminological sources that cover and integrate most of the existing medical vocabularies. Second, the exchanged data need to be processed by a machine for different purposes like patient data integration, access to literature and knowledge bases as well as clinical audit and research. Medical vocabularies provided as passive dictionaries are no longer sufficient. Software system developers should take advantage of terminological services for refining user queries, for mapping the user's terms to appropriate medical vocabularies etc. Third, the services should be accessible uniformly and transparently. In the CORBAmed initiative a proposal for a standardized interface for querying and accessing computerized medical terminology resources was created. Based on the mentioned principles the MUSTANG system (Medical UMLS based Terminology Server for Authoring, Navigating and Guiding the Retrieval to Heterogeneous Knowledge Sources) has been developed. It is implemented on a Windows NT platform using the ORACLE database management and development software. The terminological services are accessible via multiple interfaces. The MUSTANG-System and the experiences with using terminological services in practice are described. Opposed to other levels of standardization like syntactical message standards there is much more a hesitation in the use of standardized terminology.

Humans↗
PubMed2000

Phosphatidylinositol-specific phospholipase C-gamma1 undergoes pH-induced activation and conformational change.

Phospholipase C-gamma1 displayed sigmoidal kinetics with a S(0.5) value of 0.17 mole fraction PIP(2) when assayed at pH 6.8 using detergent:lipid mixed micelles. The pH optimum for hydrolysis of phosphatidylinositol 4,5-bisphosphate by phospholipase C-gamma1 was dependent on the mole fraction of substrate in the micelle. The pH optimum was 5.5 when the enzyme was assayed below the S(0.5). The pH optima shifted to a pH range of 6.0-6.3 when the enzyme was assayed above the S(0.5). The kinetic parameters for phospholipase C-gamma1 assayed at various pH values from pH 7.0 to 5.0 yielded similar n values (n=4), but the constant, K', decreased from 1x10(-2) (mole fraction)(2) at pH 7.0 to 1x10(-5) (mole fraction)(2) at pH 5.0. Maximum enzyme specificity occurred at pH values below pH 6.0 as determined by the plot of logk(cat)/S(0.5) versus pH. Intrinsic fluorescence spectroscopy revealed that at a pH value above 7.0 or below 6.3, tryptophan quenching occurred. Fluorescence quenching experiments performed with acrylamide determined phospholipase C-gamma1 incubated at pH 5.0 had a larger collisional quenching constant than enzyme incubated at pH 7.0. Lowering the pH to 5.0 apparently resulted in interior tryptophans becoming more solvent accessible. These data suggest that pH may activate phospholipase C-gamma1 by disrupting ionizable groups leading to a conformational change.

Acrylamide↗
PubMedDate not supplied

Measurement of pain in the prehospital setting using a visual analogue scale.

INTRODUCTION: The aim of this study was to use a visual analogue scale (VAS) to measure the adequacy of prehospital pain management. Patients reported pain severity at two points in time during treatment and transport by ambulance paramedics. The change in pain score was compared with a benchmark reduction of 20 mm that has been shown to correspond with the minimum clinically significant change in pain perception reported by patients. METHODS: This prospective, observational study used a VAS to record pain severity among patients reporting pain who were transported to a hospital by paramedics. Patients used a VAS to score pain severity during the initial patient assessment process (T0), and again at the hospital of destination (Tend). This study reports the mean changes in the scores, and the percentage of cases for whom the difference between T0 and Tend in the study population achieved or exceeded the 20 mm benchmark. A survey also was administered to paramedics who participated in this study in order to identify attitudes, values, and beliefs relating to the measurement of pain. RESULTS: A total of 262 patients were enrolled in this study. The mean value for the reduction in VAS (T0-Tend) was 18.2+/-23.9 mm [+/-SD] (Median = 14.0mm, 95% confidence interval (CI) = 15.3-21.1 mm). One hundred and thirty-four patients (51.1%) did not receive analgesia (either morphine sulfate or methoxyflurane). The mean initial (T0) pain score for the no-analgesia group was 54.5+/-24.7 mm [+/-SD], with the mean value for the change in VAS (T0-Tend) = 10.6 mm (median = 5 mm, 95% CI = 6.4-14.8 mm). Forty-six patients (17.6%) recorded some deterioration in their pain score at Tend (T0-Tend<0 mm). Survey results identified attitudes that may affect paramedics' pain management practice. CONCLUSION: The results suggest that inadequate analgesia is an issue in this study setting. Effective analgesia requires formal protocols or guidelines supported by effective analgesic therapies along with education that addresses attitudes that may inhibit pain assessment or management by paramedics. Regular audits form part of clinical quality assurance programs that assess analgesic practice. However, such audits must have access to data obtained from patient self-reporting of pain using a valid and reliable pain measurement tool.

Analgesics↗
PubMed2005

Descriptive epidemiology of affective disorders in multiple sclerosis.

BACKGROUND: Affective disorders present an important clinical challenge in multiple sclerosis (MS). Due to prohibitive sample size requirements, population-based studies have not yet provided an adequate description of the underlying epidemiology of this association. OBJECTIVE: To describe the epidemiology of affective disorders in MS in a general population sample. METHODS: The study presented here accessed administrative data from a universal healthcare insurance plan in the Canadian province of Alberta. Physician billing data recorded in the Alberta Health Care Insurance Plan was used to identify members of the population >15 years of age with and without MS. Crude and stratified estimates of the association between affective disorders and MS were made. Logistic regression analysis was used to evaluate statistical interactions and to provide adjusted estimates of the association. RESULTS: The estimated prevalence of MS in the population within the targeted age range (2.3 million individuals) was 386/100,000 and that of affective disorders was 7.7%. As expected, an association between MS and affective disorders was identified (crude relative prevalence: 2.2). The association varied in strength over age-sex categories. Although the prevalence of affective disorder was higher in women with MS than men with MS, the association of MS with affective disorders was stronger in men. The strength of association declined with age in both men and women. Affective disorder prevalence in people with MS becomes similar to that of the general population in older age groups. CONCLUSION: Affective disorders occur with an increased frequency in MS. This is true in men and women and across all relevant age groups, although the association gets weaker with advancing age. Higher frequencies of affective disorder occur in women with MS than in men with MS. The frequency of affective disorder in people with MS is highest in the 25-44 age group, and declines in older age categories.

Adolescent↗
PubMed2006

Dihydrogen to dihydride isomerization mechanism in [(C5Me5)FeH2(Ph2PCH2CH2PPh2)]+ through the experimental and theoretical analysis of kinetic isotope effects.

The isomerization of complex [Cp*Fe(dppe)(eta2-H2)]+, generated in situ by low-temperature protonation of Cp*Fe(dppe)H with either HBF4 or CF3COOH, to the dihydride tautomer trans-[Cp*Fe(dppe)(H)2]+ is irreversible and follows first-order kinetics in the -10 to +15 degrees C range with Delta H double dagger = 21.6 +/- 0.8 kcal mol(-1) and DeltaS double dagger = 5 +/- 3 eu. The isomerization rate constant is essentially independent of the nature and quantity of a strong acid. Density functional theory (DFT) calculations on various models, including the complete system at both the quantum mechanics/molecular mechanics (QM/MM) and full QM levels, probe the relative importance of steric and electronic effects for the relative stability of the nonclassical and classical isomers and identify two likely isomerization mechanisms: a "direct" pathway involving simultaneous H-H bond breaking and cis-trans isomerization and a "via Cp" pathway involving agostic C5Me5H intermediates. Both pathways are characterized by activation energies in close correspondence with the experimental value (21.3 and 22.2 kcal mol(-1), respectively). Further kinetic studies were carried out for the Cp*Fe(dppe)H + CF3COOD and Cp*Fe(dppe)D + CF3COOD systems at 273 K. The [Cp*Fe(dppe)(eta2-HD)]+ complex establishes a very rapid isotope redistribution equilibrium with the eta2-H2 and eta2-D2 analogues. The equilibrium constant value (K = 3.3 +/- 0.3) indicates a significant equilibrium isotope effect. Simulation of the rate data provides access to the individual isomerization rate constants kHH, kHD, and kDD for the three isotopomers, yielding kinetic isotope effects: kHH/kHD = 1.24 +/- 0.01 and kHD/kDD = 1.58 +/- 0.01 (and, consequently, kHH/kDD = 1.96 +/- 0.02). The analysis of the DFT-calculated frequencies, using the [Cp*Fe(dhpe)H2]+ model system, for the [Cp*Fe(dhpe)(eta2-XY)]+ isotopomers as well as transition states for the "direct" (TSdir) and "via Cp" (TSrot) pathways (X = H, D) allowed the computation of the expected isotope effects. A comparison with the experiment strongly suggests that the mechanism occurs via the "direct" pathway for the present system, although the small difference in the calculated energy barriers suggests that the "via Cp" pathway may be preferred in other cases.

Journal Article↗
PubMed1982

Use of adenine nucleotide derivatives to assess the potential of exo-active-site-directed reagents as species- or isozyme-specific enzyme inactivators. 5. Interactions of adenosine 5'-triphosphate derivatives with rat pyruvate kinases, Escherichia coli thymidine kinase, and yeast and rat hexokinases.

Adenosine 5'-triphosphate (ATP) derivatives of the types N6-R-ATP [R = (CH2)nNHCOCH2I, (CH2)nNHCO-(CH2)mNHCOCH2I, or (CH2)nCON(Me)(CH2)mN(Me)CO(CH2)nNHCOCH2I], N6-Me-N6-R-ATP [R = (CH2)nN-(Me)CO(CH2)mNHCOCH2I], and 8-R-ATP [R = NM(CH2)nNHCOCH2I] with 5--19 spacer atoms between N6 or C-8 and iodine have been evaluated as potential exo-ATP-site-directed reagents for phosphokinases. Substrate and inhibitor properties indicated that the compounds possessed affinity for the ATP sites of the muscle (M), kidney (K), and liver (L) isozymes of rat pyruvate kinase (PK), of E. coli thymidine kinase (TK), and of yeast hexokinase (HK) and rat KH I, II, and III isozymes. Tests for time-dependent loss of enzyme activity (inactivation) were performed under conditions in which a large proportion of each phosphokinase was present as an enzyme-inhibitor complex. No ATP-site-directed inactivations resulted when the M, L, or K isozymes of PK were exposed for 8 h, 22 degrees C, to 5 mM levels of 18 ATP derivatives or 6 analogous ADP derivatives or when yeast HK or rat KH I, II, or III was exposed for 6 h, 22 degrees C, to 5 mM levels of 28 ATP derivatives. Escherichia coli TK was inactivated by 6 of 25 ATP derivatives tested at 10 mM, 6 h, 0 degrees C; inactivation was slowed by MgATP in the case of N6-CH3-N6-R-ATP [R = (CH2)4N(CH3)CO(CH2)5NHCOCH2I]. Only 1% of 298 enzyme-inhibitor combinations exhibited ATP-site-directed inactivation, signifying that few suitably positioned and sufficiently reactive nucleophilic groups were present near the enzymic ATP sites. Studies have now shown that exo-active-site-directed reagents can act as isozyme- or species-selective enzyme inhibitors. The present survey indicates that in many cases such reagents may be difficult of access when data are not available regarding structural or physicochemical features of the target enzyme adjacent to its catalytic site.

Adenosine Triphosphate↗