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At least 523 records · Page 29Linked to original sources
PubMed2003

Motion--pancreatic endoscopy is useful for the pain of chronic pancreatitis: arguments for the motion.

Pain is the dominant clinical problem in patients with chronic pancreatitis. It can be due to pseudocysts, as well as strictures and stones in the pancreatic ducts. Most experts agree that obstruction could cause increased pressure within the main pancreatic duct or its branches, resulting in pain. Endoscopic therapy aims to alleviate pain by reducing the pressure within the ductal system and draining pseudocysts. Approaches vary according to the specific nature of the problem, and include transgastric, transduodenal and transpapillary stenting and drainage. Additional techniques for the removal of stones from the pancreatic duct include extracorporeal shockwave lithotripsy. Success rates for stone extraction and stenting of strictures are high in specialized centres that employ experienced endoscopists, but pain often recurs during long term follow-up. Complications include pancreatitis, bleeding, infection and perforation. In the case of pancreatic pseudocysts, percutaneous or even surgical drainage should be considered if septae or large amounts of debris are present within the lesion. This article describes the techniques, indications and results of endoscopic therapy of pancreatic lesions.

Calculi↗
PubMed2003

Motion - colonoscopic surveillance is more cost effective than colectomy in patients with ulcerative colitis: Arguments for the motion.

Patients with ulcerative colitis (UC) are at increased risk for colorectal cancer (CRC), especially those with longstanding disease, pancolitis or primary sclerosing cholangitis. The incidence of colitis- associated cancer is increasing, and the mortality rates from CRC are higher in UC patients than in the general population. Case control studies have demonstrated that surveillance colonoscopy reduces the risk of dying from CRC. A well conducted decision analysis found that surveillance colonoscopy decreases cancer-related mortality and increases life expectancy. The results with surveillance programs were almost as good as with prophylactic colectomy. A subsequent cost effectiveness analysis using the same model found that, compared with a policy of no surveillance, colonoscopic surveillance was more effective at preventing death from CRC and was less costly. The best strategy appears to be to perform colonoscopies every three years. The analysis also showed that colectomy should be recommended in patients with low-grade dysplasia. Patients at very high risk for CRC should undergo yearly colonoscopy, and patients who are concerned about the limitations of this technique should be offered prophylactic colectomy.

Colectomy↗
PubMed2003

Motion--Cyclo-oxygenase-2 selective nonsteroidal anti-inflammatory drugs are as safe as placebo for the stomach: arguments for the motion.

Traditional nonsteroidal anti-inflammatory drugs (NSAIDs) are known to cause gastritis, gastric and duodenal ulcers, and gastrointestinal (GI) blood loss, as well as alterations in small bowel permeability. Patients at a high risk for these complications include those who are older than 60 years of age, those with a previous history of complicated peptic disease and bleeding, and those who take high dose or multiple NSAIDs, including low dose aspirin, corticosteroids or anticoagulants. The introduction of selective inhibitors of cyclo-oxygenase-2 (COX-2) has provided effective treatment of inflammatory arthritis and musculoskeletal pain, with dramatic reductions in the risk of GI adverse events. The two most widely prescribed coxibs are celecoxib and rofecoxib, and others are being developed. Endoscopic studies have revealed that coxibs are only half as likely to induce upper GI ulceration than are traditional NSAIDs, and are as safe as placebo. Furthermore, the newer drugs do not cause excessive blood loss from the GI tract and do not affect small bowel permeability. The Vioxx Gastrointestinal Outcomes Research Study (VIGOR) revealed that the incidence of myocardial infarction was significantly lower with naproxen than rofecoxib, although this study was not designed to look at this endpoint. Coxibs are an important addition to the pharmacotherapy of inflammatory disease.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2003

Motion--pancreatic endoscopy is useful for the pain of chronic pancreatitis: arguments against the motion.

Endoscopic therapy can be used to dilate strictures in the pancreatic duct, remove stones and drain pseudocysts. In addition, it provides an alternative to surgery for the management of pain in patients with chronic pancreatitis. Pain is a difficult problem in these patients, especially if substance abuse is present, and its medical management is generally unsatisfactory. The concept that pancreatic pain is related to increased pressure in the main pancreatic duct is unproven, and is not supported by the results of surgical intervention. Although pancreatic stenting is often technically successful at achieving drainage of the pancreatic duct and relieving pain over the short term, pain usually recurs with time, complications are frequent, and repeated stent changes are usually necessary. Pancreatic pseudocysts can be drained endoscopically, using transpapillary, cystogastrostomy or cystoduodenostomy approaches, but success rates are less than 50% and bleeding is a major complication. Pseudocysts should not be drained unless they are symptomatic, causing complications or enlarging. There have been no published studies comparing endoscopic with surgical or radiological modalities. Endoscopic therapy of pancreatic disorders is a new and interesting technique, but initial promising results need to be confirmed in large, well-designed clinical trials. Such studies would need to enrol large numbers of patients, and involve measurement of technical success, pain severity and quality of life parameters. At present, endoscopic techniques must be considered experimental.

Calculi↗
PubMed2003

Motion--Cyclo-oxygenase-2 selective nonsteroidal anti-inflammatory drugs are as safe as placebo for the stomach: arguments against the motion.

Cyclo-oxygenase (COX) exists in two isoforms, COX-1 and COX-2, that direct the synthesis of prostaglandins, prostacyclin and thromboxane. Traditional nonsteroidal anti-inflammatory drugs (NSAIDs) inhibit both isoenzymes, resulting in damage to the mucosa of the stomach and duodenum, but also in cardioprotection. Selective COX-2 inhibitors are less likely to damage the upper gastrointestinal tract, as has been shown by large, randomized, controlled trials. Specifically, the newer agents are superior to ibuprofen and naproxen in this regard, but celecoxib and diclofenac were not significantly different in patients who were not also taking low-dose acetylsalicylic acid. These studies did not include a placebo arm, however, and controlled comparisons of COX-2 inhibitors with placebo have not enlisted enough subjects to demonstrate conclusively that they are equally safe. Selectivity for the COX-2 isoform affords protection against upper gastrointestinal toxicity possibly at the expense of the cardioprotective effect of traditional NSAIDs. This might explain the higher rate of nonfatal myocardial infarction in patients who are given rofecoxib compared with naproxen. A traditional NSAID, combined with either misoprostol or a proton pump inhibitor, is still a suitable alternative to selective COX-2 inhibitors for the treatment of arthritis.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2006

[Response by visual stimulation with the BOLD effect and motion artifact: identification of the activating signal and motion artifact].

This study used functional magnetic resonance imaging (fMRI) to evaluate brain function. fMRI data were collected by a block paradigm, and brain function was evaluated. However, irrelevant artifacts caused by the BOLD effect frequently occur in analytical processing. Therefore, there is a limit to obtaining an adequate activating reaction in the analytical system, which is normally equipped with MRI. However, there is a limit to obtaining a sufficient activating reaction in the analytical system, which is normally equipped with MRI. It has become standard practice to use an analytical system such as statistical parametric mapping (SPM). The response of movement of cerebrospinal fluid (CSF) artifact is high. Therefore, disappearance of the CSF artifact was done by statistical analysis. Then, the response of the signal from the beginning of stimulation was examined. As a result, the activating signal and the artifact signal could be identified.

Adult↗
PubMed1996

Phase lag of the intersegmental motion in flexion-extension of the lumbar and lumbosacral spine. An in vivo study.

STUDY DESIGN: The lumbar and lumbosacral segmental motions were analyzed in vivo using cineradiographic method. OBJECTIVES: To reveal the in vivo motion behavior of the lumbar and lumbosacral segments and their contribution to the whole lumbar motion. SUMMARY OF BACKGROUND DATA: Relation between the lumbar motion and hip joint motion has been well investigated. The lumbar motion preceded the hip flexion in forward bending and delayed from extension of the hip joints in backward bending. However, it remains unclear how the lumbar and lumbosacral segmental motion contributed to the whole lumbar motion in vivo. METHODS: Eight healthy male subjects participated in this study. The lower lumbar and lumbosacral motion (L3-S1) was recorded using cineradiography during flexion and extension. Each trunk motion was carried out from the neutral position to the maximum position. Segmental rotation and translation were measured sequentially at the L3-L4, L4-L5, and L5-S1 motion segments. RESULTS: Intersegmental motion lags were observed between the lumbar and lumbosacral motion segments during flexion. The lower lumbar and lumbosacral motion (L3-S1) was initiated at the L3-L4 motion segment. The L4-L5 segmental motion delayed from the L3-L4 motion by an average of 6 degrees and preceded the L5-S1 motion by an average of 8 degrees. In extension, motions in the L3-L4 and L4-L5 segments were small, and the L5-S1 segmental motion only contributed to the total lower lumbar motion. CONCLUSIONS: The lumbar and lumbosacral segmental motions occurred not simultaneously but stepwise from the upper level with intersegmental motion lags during flexion. These intersegmental motion lags were much larger than the neutral zone in vitro, which implied the neutral zone in vivo should be different from the neutral zone in vitro.

Adolescent↗
PubMed1986

The responsiveness of Clare-Bishop neurons to size cues for motion stereopsis.

The responsiveness to the size cue, and a combination of the size and motion cues contained in 3-dimensional motion of a visual stimulus was studied in 118 Clare-Bishop (CB) cells, including 37 and 10 cells selectively responsive to approaching (AP) and to recessive motion along the axis through the center of the receptive area and the nose (RC), 40 cells responsive to the frontoparallel motion in the horizontal direction (FP), 23 cells rather non-selectively responsive to the two types of motion (NS) and 8 cells responsive to the size cue but unresponsive to the 3-dimensional motion (SZ). About three quarters of the AP cells (27/37) were responsive to both an increase in the stimulus size and divergent motion of the retinal images in the two eyes, which represents the size and motion cues for the approaching motion along the axis through the center of the receptive area and the nose, and were optimally excited by a combination of the two visual cues. About the same fraction of the RC cells (6/10) was responsive to the motion (convergent motion) and size cues (a decrease in stimulus size), and optimally excited by a combination of the two visual cues. In contrast, only a small fraction of the FP cells (6/40) were sensitive to the size cue, and all FP cells were optimally excited by the single presentation of the motion cue for the frontoparallel motion (either right- or leftward motion in both eyes). Responses were frequently (18/40) smaller for the combined presentation of the two visual cues than for the single presentation of the motion cue. Similarly, a small fraction of the NS cells (7/23) was sensitive to the size cue, but many of them (16/23) were non-selectively responsive to the size cues for the approaching and recessive motion. A similar study in an additional 108 (78 AP and 30 RC) cells which were responsive to approaching or recessive motion vertically or obliquely deviating from the axis through the center of the receptive area and the nose demonstrated that they were also sensitive to both motion and size cues for that approaching or recessive motion, and were optimally excited by a combination of the two visual cues. These findings indicate that the CB cell responsiveness to 3-dimensional motion is based on the integration of the motion and size signals conveyed through the two eyes. A model of neuronal circuitry was constructed to explain the CB cell responsiveness to the motion and size signals.

Action Potentials↗
PubMed2003

Quantifying the effect of intrafraction motion during breast IMRT planning and dose delivery.

Respiratory motion during intensity modulated radiation therapy (IMRT) causes two types of problems. First, the clinical target volume (CTV) to planning target volume (PTV) margin needed to account for respiratory motion means that the lung and heart dose is higher than would occur in the absence of such motion. Second, because respiratory motion is not synchronized with multileaf collimator (MLC) motion, the delivered dose is not the same as the planned dose. The aims of this work were to evaluate these problems to determine (a) the effects of respiratory motion and setup error during breast IMRT treatment planning, (b) the effects of the interplay between respiratory motion and multileaf collimator (MLC) motion during breast IMRT delivery, and (c) the potential benefits of breast IMRT using breath-hold, respiratory gated, and 4D techniques. Seven early stage breast cancer patient data sets were planned for IMRT delivered with a dynamic MLC (DMLC). For each patient case, eight IMRT plans with varying respiratory motion magnitudes and setup errors (and hence CTV to PTV margins) were created. The effects of respiratory motion and setup error on the treatment plan were determined by comparing the eight dose distributions. For each fraction of these plans, the effect of the interplay between respiratory motion and MLC motion during IMRT delivery was simulated by superimposing the respiratory trace on the planned DMLC leaf motion, facilitating comparisons between the planned and expected dose distributions. When considering respiratory motion in the CTV-PTV expansion during breast IMRT planning, our results show that PTV dose heterogeneity increases with respiratory motion. Lung and heart doses also increase with respiratory motion. Due to the interplay between respiratory motion and MLC motion during IMRT delivery, the planned and expected dose distributions differ. This difference increases with respiratory motion. The expected dose varies from fraction to fraction. However, for the seven patients studied and respiratory trace used, for no breathing, shallow breathing, and normal breathing, there were no statistically significant differences between the planned and expected dose distributions. Thus, for breast IMRT, intrafraction motion degrades treatment plans predominantly by the necessary addition of a larger CTV to PTV margin than would be required in the absence of such motion. This motion can be limited by breath-hold, respiratory gated, or 4D techniques.

Algorithms↗
PubMed1999

Perceptual learning in primary and secondary motion vision.

Specific improvements of perceptual capabilities with practise are thought to give some clues about cortical plasticity and the localisation of cortical processing. In the present study, perceptual learning is used as a paradigm to separate mechanisms underlying the perception of different classes of motion stimuli. Primary motion stimuli (phi-motion), are characterised by displacements of the luminance distribution. However, for secondary motion stimuli the movement is not accompanied by a corresponding luminance shift. Instead, moving objects are defined by their temporal frequency composition (mu-motion) or by motion itself (theta-motion). On theoretical grounds, the perception of secondary motion requires a higher degree of nonlinearity in the processing stream than the perception of primary motion but debate continues as to whether there might be a unique mechanism underlying the perception of both motion classes. In a large group of subjects, coherence thresholds for direction discrimination in random dot kinematograms of phi-, mu-, and theta-motion were repeatedly measured in a staircase paradigm. Training effects were found on different timescales, within short sessions containing multiple staircases and over training periods of several months. They were fairly stable over long breaks without testing. When subjects were trained with two different motion stimuli in a sequence, an asymmetry in the transfer of perceptual learning was revealed: sensitivity increases achieved during practise of theta-motion are largely transferred to phi-motion, but theta-motion perception does not profit from prior exposure to phi-motion. This finding supports the view derived from modelling of motion processing that there must be at least partially separate systems. A primary motion detection mechanism falls short of discriminating direction in secondary motion stimuli, whereas a mechanism able to extract secondary motion will be inherently sensitive to primary motion.

Adolescent↗