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At least 595 records · Page 33Linked to original sources

PubMed2005

Exploring unexplained twofold differences in sales of cardiovascular drugs between two neighbouring Swedish municipalities.

PURPOSE: To analyse sales data for cardiovascular drugs and to explore the long-standing unexplained inter-municipality differences in out-patient sales, especially for ACE inhibitors/angiotensin II antagonists (ATC-group C09) and statins (C10AA) between two Swedish neighbouring municipalities. METHODS: Crude and age-standardised data regarding drug sales on prescription from the National Corporation of Swedish Pharmacies, was analysed. In subsequent qualitative interviews, the sales data were presented to a number of purposefully chosen key persons exploring their explanations of the long-standing large differences in the sales between the two neighbouring municipalities. RESULTS: The study confirms previous analyses that large inter-municipality differences in out-patient sales of cardiovascular drugs exist between the municipalities, differences that remained when data were standardised. In the year 2002, for example, the age-standardised out-patient sales of drugs in ATC-group C09 was 64.4 defined daily dose (DDD)/1000 inhabitants/day in one municipality compared to 112.1 in the other. For ATC-group C10AA, the corresponding figures were 41.7 and 80.9 respectively. All interviewees considered so called treatment traditions as the most important reason for the observed differences. Taking part in clinical trials was also believed to be of great importance. Activities of the Drug and Therapeutic Committees (DTC), the presence of a hospital in the municipality, marketing activities by pharmaceutical companies or differences in morbidity were not considered of major importance in explaining the differences. CONCLUSIONS: Large differences in sales data between the two municipalities remained despite age and sex standardisation. Key informants shared the view that differences in the so called 'treatment traditions' were most important for the differences.

Cardiovascular Agents↗

PubMedDate not supplied

Communication between physicians and cancer patients about complementary and alternative medicine: exploring patients' perspectives.

The aim of this paper is to identify barriers to communication between physicians and cancer patients regarding complementary and alternative medicine (CAM) by exploring the perspectives of patients. In face of the recent popularity of CAM use among cancer patients, the lack of communication is a serious problem. A number of CAM therapies may interfere with conventional treatments and thus impact patients' well-being and chances of survival. In addition, lack of communication is problematic in the health care context because the development of openness and trust between health care providers and clients is contingent upon effective interpersonal communication. We conducted semi-structured interviews with 143 cancer patients to explore their experiences with CAM use. Using a qualitative research method, we examined interview data from 93 CAM users who provided sufficient information about communication issues. As a result, three themes emerged describing barriers to unsuccessful communication as perceived from the patient's point of view: physicians' indifference or opposition toward CAM use, physicians' emphasis on scientific evidence, and patients' anticipation of a negative response from their physician. Increasing education about CAM and regular assessment of CAM use may help physicians to be more aware of their patients' CAM use. As a result, physicians may provide patients with information on risks and benefits of CAM use and refer patients to other services that may address unmet needs. Given a difference in epistemiologic beliefs about cancer and its treatment, the challenge is to find a common ground for an open discussion in which physicians consider that scientific evidence is not all that counts in the life of an individual facing a serious disease.

Adult↗

PubMedDate not supplied

Three-dimensional microscopy data exploration by interactive volume visualization.

This paper presents a new volume visualization approach for three-dimensional (3-D) interactive microscopy data exploration. Because of their unique image characteristics, 3-D microscopy data are often not able to be visualized effectively by conventional volume visualization techniques. In our approach, microscopy visualization is carried out in an interactive data exploration environment, based on a combination of interactive volume rendering techniques and image-based transfer function design methods. Interactive volume rendering is achieved by using two-dimensional (2-D) texture mapping in a Shear-Warp volume rendering algorithm. Image processing techniques are employed and integrated into the rendering pipeline for the definition and searching of appropriate transfer functions that best reflect the user's visualization intentions. These techniques have been implemented successfully in a prototype visualization system on low-end and middle-range SGI desktop workstations. Since only 2-D texture mapping is required, the system can also be easily ported to PC platforms.

Actins↗

PubMed2002

A graphical method for exploring heterogeneity in meta-analyses: application to a meta-analysis of 65 trials.

Heterogeneity can be a major component of meta-analyses and by virtue of that fact warrants investigation. Classic analysis methods, such as meta-regression, are used to explore the sources of heterogeneity. However, it may be difficult to apply such a method in complex cases or in the absence of an a priori hypothesis. This paper presents a graphical method to identify trials, groups of trials or groups of patients that are sources of heterogeneity. The contribution of these trials to the overall result can also be evaluated with this method. Each trial is represented by a dot on a 2D graph. The X-axis represents the contribution of the trial to the overall Cochran Q-test for heterogeneity. The Y-axis represents the influence of the trial, defined as the standardized squared difference between the treatment effects estimated with and without the trial. This approach has been applied to data from the Meta-Analysis of Chemotherapy in Head and Neck Cancer (MACH-NC) comprising 10,850 patients in 65 randomized trials. The graphical method allowed us to identify trials that contributed considerably to the overall heterogeneity and had a strong influence on the overall result. It also provided useful information for the interpretation of heterogeneity in this meta-analysis. The proposed graphical method identifies trials that account for most of the heterogeneity without having to explore all possible sources of heterogeneity by subgroup analyses. This method can also be applied to identify types of patients that explain heterogeneity in the treatment effect.

Clinical Trials as Topic↗

PubMed2001

Subordinates explore but dominants profit: resource competition in high Arctic barnacle goose flocks.

Social dominance plays an important role in assessing and obtaining access to patchy or scarce food sources in group-foraging herbivores. We investigated the foraging strategies of individuals with respect to their social position in the group in a flock of nonbreeding, moulting barnacle geese, Branta leucopsis, on high Arctic Spitsbergen. We first determined the dominance rank of individually marked birds. The dominance of an individual was best described by its age and its sex-specific body mass. Mating status explained the large variation in dominance among younger birds, as unpaired yearlings ranked lowest. In an artificially created, competitive situation, subordinate individuals occupied explorative front positions in the flock and were the first to find sites with experimentally enriched vegetation. Nevertheless, they were displaced quickly from these favourable sites by more dominant geese which were able to monopolize them. The enhanced sites were subsequently visited preferentially by individuals that succeeded in feeding there when the exclosures were first opened. Data on walking speed of foraging individuals and nearest-neighbour distances in the group suggest that subordinates try to compensate for a lower energy intake by exploring and by lengthening the foraging bout. Observations of our focal birds during the following breeding season revealed that females that returned to the study area were significantly more dominant in the previous year than those not seen in the area again. Copyright 2001 The Association for the Study of Animal Behaviour.

Journal Article↗

PubMed1996

CONTIG EXPLORER: interactive marker-content map assembly.

In STS-content mapping of a region, multiple optimal or near-optimal putative orders of markers exist. Determining which of the markers in this region can be placed reliably on the physical map of the chromosome and which markers lack sufficient evidence to be placed requires software that facilitates exploratory sensitivity analysis and interactive reassembly with different subsets of the imput data and that also assists the evaluation of any arbitrary (user-specified) marker order. We describe CONTIG EXPLORER, a package for interactive assembly of STS-content maps that provides the user with various ways of performing such analyses, thereby facilitating the design of laboratory experiments aimed at reducing ambiguity in STS order. We then compare the output of CONTIG EXPLORER with two other assembly programs, SEGMAP and CONTIGMAKER, for a region of chromosome 12p between 21 and 38 cM on the sex-averaged CEPH/Généthon linkage map.

Algorithms↗

PubMed1996

CA-125 levels after surgical exploration and radioactive chromic phosphate in ovarian cancer patients.

Trends in CA-125 levels after completion of therapy in ovarian cancer patients who received intraperitoneal radioactive chromic phosphate therapy (32P) after primary surgical resection or second-look surgery were evaluated. Ninety patients who underwent surgical exploration and 32P were reviewed. Twenty-nine patients were excluded due to insufficient number of CA-125 levels or recurrence within 12 months, with 61 patients with serial CA-125 levels and no evidence of disease for 12 months available for analysis. 32P followed initial resection in 24 patients (16 Stage I, 3 Stage II, 5 Stage III). 32P followed chemotherapy and second-look procedures in 37 patients (4 Stage I, 3 Stage II, 27 Stage III, 3 Stage IV). Elevated CA-125 levels were present in 25 (41%) patients within 12 months of 32P (46% after primary exploration, 38% after second-look). The degree of CA-125 elevation (U/ml) was 30-100 (23%), 100-200 (11%), and >200 (7%). Of the 25 patients with an elevated CA-125, the elevation persisted more than 4 months in 11 (44%). All but two patients had normal CA-125 levels by 12 months. An abnormal elevation in CA-125 was seen in 33% of patients 4 months after receiving 32P and abdominal surgery, with values ranging as high as 500 U/ml. Although elevations in CA-125 are reported following surgery alone, the duration of elevation appears to be longer with 32P. Therefore, persistent elevations of CA-125 following 32P between 4 and 12 months should be judged with caution as they may not reflect recurrent disease.

CA-125 Antigen↗

PubMed2000

The state and future of Mars polar science and exploration.

As the planet's principal cold traps, the martian polar regions have accumulated extensive mantles of ice and dust that cover individual areas of approximately 10(6) km2 and total as much as 3-4 km thick. From the scarcity of superposed craters on their surface, these layered deposits are thought to be comparatively young--preserving a record of the seasonal and climatic cycling of atmospheric CO2, H2O, and dust over the past approximately 10(5)-10(8) years. For this reason, the martian polar deposits may serve as a Rosetta Stone for understanding the geologic and climatic history of the planet--documenting variations in insolation (due to quasiperiodic oscillations in the planet's obliquity and orbital elements), volatile mass balance, atmospheric composition, dust storm activity, volcanic eruptions, large impacts, catastrophic floods, solar luminosity, supernovae, and perhaps even a record of microbial life. Beyond their scientific value, the polar regions may soon prove important for another reason--providing a valuable and accessible reservoir of water to support the long-term human exploration of Mars. In this paper we assess the current state of Mars polar research, identify the key questions that motivate the exploration of the polar regions, discuss the extent to which current missions will address these questions, and speculate about what additional capabilities and investigations may be required to address the issues that remain outstanding.

Atmosphere↗

PubMed2001

Exploring red deer culling strategies using a population-specific calibrated management model.

Wildlife management is generally carried out under conditions of uncertainty. The exact population size is unknown, its future dynamics are uncertain and clear management objectives are often not formulated. In order to provide management advice in this situation, a framework is presented for combining different sources of information using a Bayesian approach for calibrating a management model. Harvesting strategies can then be explored based on predictions of future populations size and structure which incorporate parameter uncertainty. This method makes it possible to evaluate the probability of achieving certain objectives with different management strategies. The advantage of the approach presented in this paper lies in that both the model and the harvesting strategies are adaptable to any particular population of interest. The approach is illustrated for two Scottish red deer populations for which culling strategies corresponding to different management objectives are explored and their benefits evaluated. It is found that each population requires different culling rates for keeping population number stable, demonstrating the benefits of the population specific calibration of the management model.

Animals↗

PubMed1994

Preliminary experience with magnetic resonance venography: comparison with findings at surgical exploration.

While conventional magnetic resonance imaging has been described for the evaluation of the venous system, we have recently developed the technique of magnetic resonance venography (MRV), which generates three-dimensional projection venograms. Our purpose was to determine if MRV reliably images the venous system by comparison with findings at surgical exploration. Thirteen of fourteen consecutive patients undergoing bypass surgery (26 limbs) were studied by 2D time-of-flight MRV preoperatively from the inguinal ligament to the ankle bilaterally. The average examination time was 50 min. The size and quality of each saphenous vein were recorded at the saphenofemoral junction, mid-thigh, knee, mid-calf, and malleolus. Intraoperatively the quality and size of each vein were measured in situ and when distended by saline. Twelve veins were of good quality. MRV predicted this in every case. One vein, found to be recanalized, had an abnormally thick wall noted on MRV. MRV measurements of average vein size were intermediate between that of the in situ and distended vein and correlated most closely with the distended vein (R = 0.74, P < 0.001). The superficial and deep femoral veins and lesser saphenous veins were routinely visualized by MRV; thus a complete map of all available vein was obtained by a single study. It is concluded that MRV is an accurate method of venous imaging as confirmed by findings at operative exploration. This new technique holds promise as a noninvasive method for evaluation of the venous system and warrants further investigation.

Coronary Artery Bypass↗

PubMed2002

Exploring the formation of Alzheimer's disease senile plaques in silico.

An experimental simulation environment suitable for exploring the neuroinflammatory hypothesis of Alzheimer's disease (AD) has been developed. Using scientific literature, we have calculated parameters and rates and constructed an interactive model system. The simulation can be manipulated to explore competing hypotheses about AD pathology, i.e. can be used as an experimental "in silico" system. In this paper, we outline the assumptions and aspects of the model, and illustrate qualitative and quantitative findings. The interactions of amyloid beta deposits, glial cell dynamics, inflammation and secreted cytokines, and the stress, recovery, and death of neuronal tissue are investigated. The model leads to qualitative insights about relative roles of the cells and chemicals in the disease pathology.

Alzheimer Disease↗

PubMed2003

An in silico exploration of the neutral network in protein sequence space.

Designating amino-acid sequences that fold into a common main-chain structure as "neutral sequences" for the structure, regardless of their function or stability, we investigated the distribution of neutral sequences in protein sequence space. For four distinct target structures (alpha, beta,alpha/beta and alpha+beta types) with the same chain length of 108, we generated the respective neutral sequences by using the inverse folding technique with a knowledge-based potential function. We assumed that neutral sequences for a protein structure have Z scores higher than or equal to fixed thresholds, where thresholds are defined as the Z score for the corresponding native sequence (case 1) or much greater Z score (case 2). An exploring walk simulation suggested that the neutral sequences mapped into the sequence space were connected with each other through straight neutral paths and formed an inherent neutral network over the sequence space. Through another exploring walk simulation, we investigated contiguous regions between or among the neutral networks for the distinct protein structures and obtained the following results. The closest approach distance between the two neutral networks ranged from 5 to 29 on the Hamming distance scale, showing a linear increase against the threshold values. The sequences located at the "interchange" regions between the two neutral networks have intermediate sequence-profile-scores for both corresponding structures. Introducing a "ball" in the sequence space that contains at least one neutral sequence for each of the four structures, we found that the minimal radius of the ball that is centered at an arbitrary position ranged from 35 to 50, while the minimal radius of the ball that is centered at a certain special position ranged from 20 to 30, in the Hamming distance scale. The relatively small Hamming distances (5-30) may support an evolution mechanism by transferring from a network for a structure to another network for a more beneficial structure via the interchange regions.

Amino Acid Sequence↗

PubMed2000

Neural correlates of topographic mental exploration: the impact of route versus survey perspective learning.

There are two major sources of information to build a topographic representation of an environment, namely actual navigation within the environment (route perspective) and map learning (survey perspective). The aim of the present work was to use positron emission tomography (PET) to compare the neural substrate of the topographic representation built from these two modes. One group of subjects performed a mental exploration task in an environment learned from actual navigation (mental navigation task). Another group of subjects performed exploration in the same environment learned from a map (mental map task). A right hippocampal activation common to both mental navigation and mental map tasks was evidenced and may correspond the neural substrate of a "dual-perspective" representation. The parahippocampal gyrus was additionally activated bilaterally during mental navigation only. These results suggest that the right hippocampus involvement would be sufficient when the representation incorporates essentially survey information while the bilateral parahippocampal gyrus would be involved when the environment incorporates route information and includes "object" landmarks. The activation of a parietofrontal network composed of the intraparietal sulcus, the superior frontal sulcus, the middle frontal gyrus, and the pre-SMA was observed in common for both mental navigation and mental map and is likely to reflect the spatial mental imagery components of the tasks.

Adult↗

PubMed1995

Laparoscopic choledochoscopy with a small-caliber endoscope. A safe and effective technique for laparoscopic common bile duct exploration.

Incidental choledocholithiasis has been reported in 4-5% of cases during routine cholangiography. Many surgeons have resisted laparoscopic common bile duct exploration as a time-consuming and technically frustrating procedure, preferring to send the patient for postoperative ERCP. The purpose of this study was to objectively assess the safety, efficacy, and facility of transcystic duct choledochoscopy using a small-caliber choledochoscope with facilitated insertion technique. Twenty-five consecutive patients scheduled for laparoscopic cholecystectomy (LC) were studied prospectively. Choledochoscopy was carried out with a simplified introducer system using a 6.9-French choledochoscope. An arbitrary limit of 10 min was established for gaining access to the common bile duct (CBD). Incidental CBD stones were found in two of the 25 procedures (8%) and were cleared laparoscopically. The CBD was successfully entered in 21 of 25 attempts (84%). The average time for the entire procedure was 8.7 min. There were no procedure-related complications. Clinical application of this procedure was reviewed in a personal series of 742 LCs. Transcystic laparoscopic common bile duct exploration (LCDE) was successful in clearing stones from the CBD 75% of the time and the addition of laparoscopic choledochotomy brought the success of LCDE to 81%. Excluding patients where transcystic LCDE was not attempted, the overall success rate was 91%.

Adult↗

PubMed1995

Documentation of abdominal exploration during laparoscopic cholecystectomy.

UNLABELLED: To assess the documentation of intraperitoneal exploration and events during laparoscopic cholecystectomy, we reviewed 200 dictated operative reports from eight different institutions. The 200 laparoscopic cholecystectomies were performed by 40 different surgeons on 158 female patients and 42 male patients. A description of the gallbladder was included in 134 (67%) reports and not mentioned in 66 (33%) reports. Fifty-four (27%) reports did not mention any intraperitoneal findings away from the gallbladder. Another 36 (18%) of the reports contained only a general comment indicating that no abnormalities were seen in the abdomen (excluding the gallbladder). The other 110 (55%) reports mentioned at least one specific site or finding in the abdomen other than the gallbladder. The most commonly mentioned sites were the liver, bowel, and stomach. Only 42 (21%) operative notes described what happened to the gallbladder contents: 30 described spillage of bile and/or gallstones and 12 stated that no spillage occurred. CONCLUSIONS: Laparoscopic cholecystectomy operative notes have often lacked a description of gallbladder appearance, documentation of abdominal exploration, and/or documentation of complete removal of the gallbladder and its contents.

Abdomen↗

PubMed1986

Persistent hypercalcemia after neck exploration--an analysis of 34 cases.

A retrospective analysis of 34 patients undergoing 45 re-explorations for persistent hypercalcemia is presented. Thirteen out of the 20 enlarged parathyroid glands were found at reoperation to be normally located, indicating that the initial exploration had been incomplete. A follow-up study of the reoperated patients showed that 25 (74%) were normocalcaemic. Three patients had permanent unilateral recurrent laryngeal nerve damage and 2 patients required calcium and/or vitamin D therapy. Ultrasonography was effective in the diagnosis and localisation of residual parathyroid adenoma in patients with persistent postoperative hyperparathyroidism.

Adenoma↗

PubMed1987

Tactile exploration of space and visual neglect in brain-damaged patients.

A maze test of tactile scanning was used to investigate the relationship between visual neglect and the tactile modality of space exploration in 46 patients with right-sided brain damage (RBD) (20 with and 26 without visual neglect), 27 patients with left-sided brain damage (LBD) and 30 controls. Both LBD and RBD patients that were free from visual neglect more frequently used the tactile mode to explore the space contralateral to the sound hemisphere, while the RBD patients affected by visual hemi-inattention preferred tactile scanning of the left, visually neglected, half of space. Some implications of these findings are discussed. In particular, the modality-specific nature of neglect phenomena and the possibility of tactile compensation are suggested.

Aged↗

PubMed1989

Behavioral effects of alpha 2 adrenoceptor antagonists and their interactions with ethanol in tests of locomotion, exploration and anxiety in mice.

The behavioral effects of two highly selective alpha 2-adrenoceptor antagonists, atipamezole and idazoxan, were investigated in mice using the plusmaze test of anxiety and the holeboard test of directed exploration and locomotor activity. No anxiogenic effect, as assessed by the tendency to enter the closed as opposed to open arms of the plusmaze, was noted for either drug at any dose tested. Neither were there any significant effects on locomotor activity or directed exploration (head-dipping) in the holeboard, or total plusmaze arm entries at any dose of either drug. The co-administration of either atipamezole or idazoxan had no effect on either the anxiolytic effect of ethanol (2 g/kg) or its locomotor stimulant effect in the holeboard. Atipamezole (1.0 and 3.0 mg/kg) significantly reversed the ethanol-induced reduction in exploratory head-dipping; a similar trend was seen for idazoxan. There was also a significant potentiation of the ethanol-induced increase in the number of total arm entries made on the plusmaze caused by 1.0 mg/kg (but not 3.0 mg/kg) atipamezole and both 0.3 and 1.0 mg/kg idazoxan. The results suggest that some of the behavioral effects of ethanol can be reversed by alpha 2-adrenoceptor antagonists whilst others are unchanged.

Adrenergic alpha-Antagonists↗