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At least 775 records · Page 43Linked to original sources
PubMed1998

Pulmonary artery growth after systemic-to-pulmonary shunt in children with a univentricular heart and a hypoplastic pulmonary artery bed. Implications for Fontan surgery.

The aim of the study was to investigate the developmental pattern of hypoplastic pulmonary artery (p.a.) bed augmented by systemic-to-pulmonary shunt in children with univentricular heart scheduled for Fontan surgery. For the study, a highly selected patient cohort was chosen (12 patients aged between 5 and 19 years; mean 9.5 years) with comparable initial morphological conditions of univentricular heart and hypoplastic p.a. bed, who after mandatory systemic-to-pulmonary shunt underwent Fontan procedure at time of normalization of pulmonary artery size. Further selection criteria were: normal pulmonary vascular resistance at time of Fontan procedure, competent a-v valve(s), and globally unimpaired ventricular function. All patients were grouped according to the preoperative pulmonary flow index (Qpi; L/min/m2 b.s.a.) measured immediately before Fontan operation: Group A: 1.5-2.5; B: 3.0-4.0; C: 4.0-5.0; D: > 6.0, and their cardio-pulmonary hemodynamic situation (Hb, SAsat%, Qp/Qs, PAP, Rp/Rs, EDVP, FS%, ventricular diastolic compliance (VC = EDVP/Qpi + Qsi) as well as the pulmonary artery size and area using standard (Nakata-index, McGoon-ratio) and a self designed computer assisted planimetric area calculation (PPAAI; cm2/m2 b.s.a.) analysed. Each patient underwent 1-3 shunt procedures, the mean shunt patency period for groups A, B, C and D was 12, 8.6, 5.3, and 4.5 years, respectively. The mean Nakata-index (283, 297, 324, 405 in groups A-D) and the McGoon-ratio (2.0, 2.2, 2.8, 3.3 in groups A-D) correlated with the Qp index, reflecting flow dependent development of pulmonary artery bed. No correlation was found between Qpi and PPAAI (47, 40, 41 and 47 in group A-D). The VC/Qp relation showed an inversely proportional pattern with values 2.3, 1.0, 0.8, 0.7 for corresponding groups A-D, the lowest VC in group A correlated with polyglobulic status (Hb- values; g/dl): 21.3 in A vs 19.8, 18.0 and 16.5 in B-D) and mean arterial SAsat-values (77% in A vs 83%, 84% and 89% in B-D). In conclusion, in our highly selected patient cohort, the development of p.a. size was strongly flow-dependent, and patients with restrictive pulmonary flow needed an approximately threefold longer time period to normalize their p.a. size compared to those with excessive flow. In patients with restrictive pulmonary flow, the Nakata-index underestimated the degree of development of the pulmonary artery system, probably due to the distortion of the proximal p.a. segment. In consequence, in these patients the normalization of the p.a. bed and thus suitability for the Fontan procedure probably occurred much earlier. Based on our observations and those of others, in patients with excessive flow the normalization of p.a. bed, provided it occurs within 3-4 years, seems not necessarily to be associated with a deterioration of ventricular function.

Adolescent↗
PubMed1995

Cost savings associated with detection and treatment of diabetic eye disease.

OBJECTIVE: Diabetic retinopathy, which leads to macular oedema and retinal neovascularisation, is the leading cause of blindness among working age Americans. Research has demonstrated significant cost savings associated with detection of eye disease in Americans and Europeans with insulin-dependent diabetes mellitus (IDDM, type I diabetes) and non-insulin-dependent diabetes mellitus (NIDDM, type II diabetes). In this report, we estimate the current and potential savings in both the United States and in a European country resulting from the screening and treatment of retinopathy in persons with diabetes. DESIGN: Computer modelling, incorporating data from population-based epidemiological studies and multicentre clinical trials. Monte Carlo simulation was used, combined with sensitivity analysis and present value analysis of cost savings. RESULTS: Detection and treatment of diabetic eye disease in both the United States and Scandinavia is not only cost effective, but is actually cost saving from the governmental perspective. Potential savings in the United States exceed $US600 million annually, while, in Sweden, potential savings of 36 million SEK might be realised. These findings are comparable given the differences in population between the 2 countries. CONCLUSIONS: Our analysis indicates that prevention programmes aimed at improving eye care for persons with diabetes not only reduce needless vision loss, but also provide a financial return on the investment of public funds.

Diabetes Mellitus, Type 1↗
PubMed1980

Digital subtraction angiography of the human cardiovascular system.

Initial clinical application of a system for digital subtraction angiography (DSA) to the human cardiovascular system in 88 patients is reported. The equipment consisted of a specially designed computer system integrated with a fluoroscopic and radiographic apparatus for digitization, manipulation, and display of data. After intravenous injection of contrast material, adequate visualization of the heart and carotid, thoracic, abdominal, and femoral arteries was obtained with sufficient quality to obviate conventional angiography in many clinical settings. In this mode, nonselective opacification is obtained. However, DSA was also used to extend the capability of selective angiography. The availability of quantitative information permitted the determination of rates of transit of contrast material in various organs which may give insights of their physiologic performance.

Aneurysm↗
PubMed1994

Orbital reconstruction with hydroxyapatite ceramic implants.

Thirteen patients with fractures of the orbital floor (inferior wall), medial and lateral walls, or so-called "blowout" fractures with or without fractures of the zygoma were treated with artificially made hydroxyapatite ceramic implants made entirely from limestone, some of which were made with computer aided design and computer aided machinery (CAD-CAM) from data obtained from helical computed tomography. Orbital reconstruction with hydroxyapatite ceramic implants is a safe technique which is superior to previous ones in which autogenous or plastic materials were used.

Adult↗
PubMed1996

Cost-effectiveness of detecting and treating diabetic retinopathy.

OBJECTIVE: To determine, from the health insurer's perspective, the cost of preventing vision loss in patients with diabetes mellitus through ophthalmologic screening and treatment and to calculate the cost-effectiveness of these interventions as compared with that of other medical interventions. DESIGN: Computer modeling, incorporating data from population-based epidemiologic studies and multicenter clinical trials. Monte Carlo simulation was used, combined with sensitivity analysis and present value analysis of cost savings. RESULTS: Screening and treatment of eye disease in patients with diabetes mellitus costs $3190 per quality-adjusted life-year (QALY) saved. This average cost is a weighted average (based on prevalence disease) of the cost-effectiveness of detecting and treating diabetic eye disease in those with insulin-dependent diabetes mellitus ($1996 per QALY), those with non-insulin-dependent diabetes mellitus (NIDDM) who use insulin for glycemic control ($2933 per QALY), and those with NIDDM who do not use insulin for glycemic control ($3530 per QALY). CONCLUSIONS: Our analysis indicates that prevention programs aimed at improving eye care for diabetic persons not only result in substantial federal budgetary savings but are highly cost-effective health investments for society. Ophthalmologic screening for diabetic persons is more cost-effective than many routinely provided health interventions. Because diabetic eye disease is the leading cause of new cases of blindness among working-age Americans, these results support the widespread use of screening and treatment for diabetic eye disease.

Age of Onset↗
PubMed1998

[Use of a PCR method for controlling pure-breeding of honeybees Apis mellifera mellifera L. in the southern Urals].

A key problem of honeybee (Apis mellifera mellifera) breeding in the Southern Urals is its cross-breeding with the Caucasian honeybee Apis mellifera caucasica. Mitochondrial DNA (mtDNA) in these subspecies differ in the length of a fragment localized between genes CO-I and CO-II, which can be used as a marker. A pair of 20-mer primers for PCR was chosen by means of computer design in order to determine the fragment size in both of the subspecies. The amplified fragment was shown to have a length of 350 bp in A. m. caucasica and 600 bp in A. m. mellifera. The difference in length results from the different ratio between two main elements P and Q, which comprise a major part of this sequence in these subspecies: a copy of P element and two copies of Q element in A. m. mellifera, and a copy of Q element only in A. m. caucasica. This sharply defined distinction allows us to use PCR for differentiating the subspecies, estimating the heterogeneity in the colonies, and rejecting queens in the selection process because of the maternal inheritance of the studied character. The nucleotide sequence of the amplified mtDNA fragment of A. m. mellifera was determined.

Amino Acid Sequence↗
PubMed1999

Maintenance of complex performance during a 135-day spaceflight simulation.

BACKGROUND: The maintenance of crew performance during extended space missions has been a major concern because of the problems associated with prolonged isolation and confinement. Previous research has failed to address this problem by not using appropriate performance tests. METHOD: Three Russian cosmonauts were tested on a PC-based simulation of a spacecraft's life support system during a 135-d simulation of a MIR spaceflight. A complex multiple-task environment was used to examine a comprehensive range of task management variables, including both primary and secondary task performance, control activity and information sampling behavior. Subjective state variables were also measured. RESULTS: The data suggested an overall successful adjustment to isolation and confinement, though some indications of temporary disruptions of some performance indicators were observed. Information sources were sampled less frequently with increasing mission length while system control activities showed a tendency to increase. CONCLUSION: Suggestions are made to address the problem of continuous learning during repeated testing sessions. Using well-designed computer simulations of complex task environments appears to be a promising approach for the evaluation of crew member performance.

Adult↗
PubMed1995

The road to business process improvement--can you get there from here?

Historically, "improvements" within the organization have been frequently attained through automation by building and installing computer systems. Material requirements planning (MRP), manufacturing resource planning II (MRP II), just-in-time (JIT), computer aided design (CAD), computer aided manufacturing (CAM), electronic data interchange (EDI), and various other TLAs (three-letter acronyms) have been used as the methods to attain business objectives. But most companies have found that installing computer software, cleaning up their data, and providing every employee with training on how to best use the systems have not resulted in the level of business improvements needed. The software systems have simply made management around the problems easier but did little to solve the basic problems. The missing element in the efforts to improve the performance of the organization has been a shift in focus from individual department improvements to cross-organizational business process improvements. This article describes how the Electric Boat Division of General Dynamics Corporation, in conjunction with the Data Systems Division, moved its focus from one of vertical organizational processes to horizontal business processes. In other words, how we got rid of the dinosaurs.

Commerce↗
PubMed1999

Semantic processing deficits in patients with Parkinson's disease: degraded representation or defective retrieval?

OBJECTIVE: To determine whether degraded representations (characterized by small differences between word sense frequencies), or defective competitive processes (high levels of word sense lateral inhibition), individually or jointly, can give rise to parkinsonian semantic deficits. DESIGN: Computer model of semantic processing. OUTCOME MEASURES: Correct sense selection, defined by the activation of the word sense unit that first reaches the 0.5 activation threshold. If Parkinson disease (PD)-like errors are observed only at high levels of lateral inhibition, independently of low or high sense frequency deltas (SFDs), this would indicate that a defective competitive process alone could account for the errors. Alternatively, if PD-like errors were observed at any level of lateral inhibition, exclusively with low SFD words, this would indicate that degraded representations alone could account for the errors. RESULTS: Neither degraded representations nor defective competitive processes alone can account for parkinsonian semantic errors. An interaction between the 2, however, correctly reproduces both increased errors and longer latency responses. CONCLUSIONS: Competing explanations for semantic deficits in patients with Parkinson's disease need to be integrated in order to develop effective interventions (e.g., estimating the amount of context required to improve semantic processing performance).

Humans↗
PubMed2000

Determination of the putative binding sites for thrombin receptor activating peptide through a hydropathic complementary approach.

Putative binding sites in a platelet thrombin receptor (PAR-1) for the activating peptide SFLLRNPNDKYEPF (AP) and for the bradykinin analogue MKRPPGFSPFRSSRIG were revealed using a computer program for identifying complementary peptide segments. The program is based on the assumption that interactions of agonist's peptides and protein's receptors can be elucidated by complementary average hydropathies as much as possible equal by size and opposite by sign. Some of the computer-found putative binding sites were close to the supposed AP-PAR-1 contacts in the amino-terminal exodomain and in the second extracellulary loop of PAR-1. Peptides complementary to these binding sites were also computer-designed and were synthesized. They mostly inhibited the aggregation of gel filtered platelets by thrombin (0.025 U/mL) with IC50 in a high micromolar range of concentrations. The peptide complementary to site L258-Y269 of PAR-1 induced aggregation of gel filtered platelets with EC50 = 98 [micromol/L] related to thrombin (0.025 U/mL) aggregation response.

Amino Acid Sequence↗
PubMed1999

[Main principles of bone marrow puncture biopsy studies].

A scheme for morphologic analysis of bone marrow puncture biopsy specimens, order of operations, description of the specimen and its composition by hemopoiesis stems, and order and variants of description of the morphology of unidentified cells are proposed. The paper is recommended as a methodological guide for clinical laboratory diagnosis and a base for designing computer program.

Biopsy↗
PubMed2000

HGML: a hypertext guideline markup language.

Existing text-based clinical practice guidelines can be difficult to put into practice. While a growing number of such documents have gained acceptance in the medical community and contain a wealth of valuable information, the time required to digest them is substantial. Yet the expressive power, subtlety and flexibility of natural language pose challenges when designing computer tools that will help in their application. At the same time, formal computer languages typically lack such expressiveness and the effort required to translate existing documents into these languages may be costly. We propose a method based on the mark-up concept for converting text-based clinical guidelines into a machine-operable form. This allows existing guidelines to be manipulated by machine, and viewed in different formats at various levels of detail according to the needs of the practitioner, while preserving their originally published form.

Decision Support Systems, Clinical↗
PubMed2000

Mortality from cardiovascular diseases and its relationship to air temperature during the winter months in Dublin and Oslo/Akershus.

In many countries increased winter mortality from cardiovascular diseases (CVD) has been documented. A causal relationship between change in air temperature and change in number of deaths has been suggested. There is also evidence for a delay between a fall in air temperature and death (lag effect). We have investigated these relationships using mortality data for CVD (ICD-9: 390-459) and daily air temperatures in selected winter months (December to March) from two densely populated areas in Norway and Ireland, Oslo/Akershus and Dublin. A specially designed computer programme was used to select data from specific days in the ten years period. The days selected depended on the temperature change chosen between two consecutive days. We examined 2 types of temperature change, a large change and little or no change. An analytical technique involving the use of Spearman's correlations coefficients was used to investigate delays in mortality following a particular change in temperature. For groups of selected days, an inverse relation between mortality and air temperature was found. For neither the Oslo/Akershus nor the Dublin data was it possible to see a sudden increase in mortality following a large, sudden decrease in temperature and no evidence for a delay between a change in temperature and a change in mortality rate was found.

Aged↗
PubMed1999

[In vitro cleavage action of c-erbB-2 oncogene-specific ribozyme].

OBJECTIVE: To construct in vitro transcription vectors of genes of c-erbB-2 specific ribozyme and its substrate and to probe its in vitro cleavage action. METHODS: According to the computer design, a specific restriction site EcoR V was added to the 3' end of the ribozyme gene (RZ1). Then, the RZ1 gene and its substrate gene were cloned into the in vitro transcription vector pGEM3Zf(-) separately. The recombinants containing RZ1 gene were first screened by agrose ge1 electrophoresis through EcoR V digestion and was identified by automatic sequencing. The products of in vitro transcription were labeled with 32P. In vitro cleavage reaction was performed at 37 degrees C for 1 h under the presence of Mg++. The cleavage product was analyzed by polyacrilamide gel electrophoresis. After autoradiography, the cleavage rate was counted by image analysis. RESULTS: The recombinants containing the RZ1 gene were successfully selected by the EcoR V digestion and were designated as pGM3Z-RZ1. The automatic sequence analysis proved that the synthesized RZ1 gene was correct. The target gene was also cloned into the pGEM3Zf(-) under SP6 promoter. After in vitro transcription, the cleavage reaction was shown to have cut off 79.3% target RNA in 1 h. CONCLUSION: The c-erbB-2 oncogene-specific ribozyme has a high activity in vitro. It lays a foundation for the study of the therapeutic use of ribozyme in gene therapy of cancer.

Genes, erbB-2↗
PubMed2003

Cephalometric norms for the upper airway in a healthy Hong Kong Chinese population.

OBJECTIVE: To obtain normative data for cephalometric measurements of the upper airway in the local Chinese population. DESIGN: Observational study. SETTING: University department and teaching hospital out-patient clinic. SUBJECTS AND METHODS: Subjects included 74 healthy patients, 29 males (age range, 18-35 years) and 45 females (age range, 16-42 years), with normal skeletal facial profile, no history of snoring, sleep apnoea, upper airway disease, tonsillectomy or adenoidectomy, obesity, or pathology in the pharynx. Twenty cephalometric airway measurements, including size of the tongue, soft palate, nasopharynx, oropharynx, hypopharynx, and relative position of the hyoid bone and valleculae were obtained. Landmarks on cephalometric radiographs were digitised and measurements were made using a specially designed computer programme. Error analysis of measurements was performed and comparison of measurements according to sex was made. RESULTS: Significant sex dimorphism was seen for the majority of measurements, with the exception of minimal depth of the airway, oropharyngeal depth of the airway, and the soft palate angle with the hard palate. CONCLUSION: A minimum sagittal dimension of the upper airway was evident despite differences in measurements between sexes. Findings from this study should be a useful reference for the assessment of sleep apnoea in the local population.

Adolescent↗
PubMed1999

Use of collaborative audit to assist local implementation of the SIGN guideline for prevention of visual impairment in diabetes.

OBJECTIVES: To use audit to inform the local implementation of a national clinical guideline for the prevention of visual impairment in diabetes. DESIGN: Computer and patient record search in hospital and general practice to determine levels of morbidity and follow-up. Questionnaire to each practice to determine models and techniques of eye screening. SETTING: Ayrshire and Arran Health Board area, Scotland. SUBJECTS: All known diabetic patients. MAIN MEASURES: Proportion of diabetic patients who have had diabetic eye review and monitoring of risk factors within one year. Proportion of diabetic patients who have risk factors recorded within target level. Proportion of eye screening centres with recommended mechanisms in place. RESULTS: Both district general hospitals, and 59 of the 63 general practices, in the area took part in the audit. A total of 6,217 diabetic patients were included; the prevalence of diabetes in this population was 1.65%. Twenty-seven per cent were insulin treated. Seventy-two per cent of diabetics who were not registered blind had a record of having had fundoscopy performed through dilated pupils within one year. Sixty-nine per cent of those who were not registered blind had had corrected visual acuity measured within one year. Eighty-five per cent of diabetics had HbA1C recorded within one year and of these 65% had a level of 8% or less. Eighty-eight per cent had a blood pressure recording within twelve months and 52% of recorded pressures were 140/90 mmHg or less. Smoking status was recorded for 89% of patients and 75% of patients with a record were non-smokers. Representatives of 57 practices returned a completed questionnaire. All these practices had a Snellen chart, but only 83% had near vision testing equipment and only 54% had a pinhole occluder. CONCLUSIONS: An area wide collaborative audit provided local data to inform the process of guideline implementation and baseline data from which to evaluate this process. Wide stakeholder involvement increased interest, motivation and support for the process. The audit highlighted specific areas for change and provided the local stimulus for change.

Cooperative Behavior↗
PubMed2001

[Anesthesiology consulting unit in perioperative medicine].

There is a demand, caused by increase of one-day surgery, surgery of high risk patients with coexisting diseases, and growing need for patient education, for such improvement of preoperative preparation, which will enable an optimalization in patient care. That became a special task of Preanesthetic Evaluation Clinic. The aim of the paper was to analyze activity of local Preanesthetic Evaluation Clinic in years 1993-2000. Special emphasize was put on: assessment of Clinic functioning, with regard to variety of consultations, perioperative patient education, use of perioperative risk scales, processing of guidelines of laboratory tests in particular groups of patients, assessment of perioperative fear factors. Analyze of consultations was conducted using custom design computer program, operated in the "Clinic since" 1997. Discussing own experiences, a necessity of patient education was emphasized as a significant factor lowering perioperative fear. There was also a presentation of perioperative risk assessment methods as well as guidelines of laboratory tests improving clinical effectiveness. Information for patients, prepared in the Clinic "What should you know about anesthesia" was described. As conclusions perspectives of further development of the Clinic were shown. Growing significance of an anesthetic nurse in perioperative patient preparation was foreseen. A demand for improving electronic patient records as well as use of new technologies was proven.

Ambulatory Surgical Procedures↗
PubMed2001

Ultradian rhythms in processing speed of laterally exposed words and pictures.

The study was designed to find out the cerebral hemispheres oscillations in stimuli processing during the 24-hour period of wakefulness in isolated subjects remaining in a monotonous environment. Stimuli processing speed from the 24-hour constant routine periods (06.00-06.00 h) of a larger experiment were analysed for the purpose of this paper. Parallel sets of words and pictures were exposed laterally using a purpose-designed computer program. The subjects reacted to pictures or words by pressing appropriate buttons. The significant dominant ultradian rhythms (around 4 h) in the processing speed of words addressed to the right hemisphere were found and of pictures addressed to the left hemisphere. Longer significant dominant periodicities (around 12 h) appeared in the processing speed of words addressed to the left hemisphere and of pictures (around 8 h) addressed to the right hemisphere. Ultradian rhythmicity of the central nervous system functioning is suggested.

Activity Cycles↗