PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “motor function”

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

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

At least 1,207 records · Page 67Linked to original sources

Assessment of gastric motor function during the emptying of solid and liquid meals in humans by MRI.

Gastric emptying and motility have previously been assessed by magnetic resonance imaging (MRI) using liquid test meals. The aim of this study was to extend the applicability of our MRI method to the assessment of gastric emptying and motility of solid meals. Gastric emptying and motility of a liquid and a solid meal, of similar chemical properties, were studied in eight volunteers. The MRI protocol combined a multislice turbo spin-echo (TSE) sequence (volume scan, resolution: 1.5 mm) and a dynamic FFE sequence (motility scan, 1 sec/image, resolution: 3.1 mm). Gastric emptying of the liquid meal was faster than emptying of the solid meal when considering half-times of emptying. However, during the first 15 minutes after ingestion, the liquid meal emptied more slowly. This was related to reduced motility with the liquid meal. In conclusion, with our MRI method it is feasible to assess gastric emptying and motility of liquid and solid meals.

Adult↗

Body weight: its relation to tissue composition, segment distribution, and motor function. I. Interspecific comparisons.

The composition of skin, muscle, and bone and their distribution throughout the body are compared for "advanced" or "specialized" species (Alouatta, Macaca, Canis, Felis, Lepus); smaller, more closely related species (Tupaia and the Lorisidae); and several species within the same ecosystem (Barro Colorado Island, Panama). Among the most significant variables, the skin of sloths, howlers and macaques constitutes more than 12% of body weight, whereas greyhound skin is 5% of weight; sloth and howler muscle are 25% of weight, macaque muscle about 40% of weight, greyhound and agouti muscle over 50% of weight. In tree shrews and galagos muscle is heavier (35%) than in pottos and slow lorises (below 28%), but bone and skin are lighter. All species differ in the segmental distribution of weight. Cats have light tails, light feet and heavy thighs, whereas howlers have heavy tails, heavy feet, and light thighs. The galagos have heavy hindlimbs and tails, the pottos and lorises have reduced tails and approximately equal fore- and hindlimbs. Convergences in segment pattern (sloths with pottos and lorises, marmosets with tree shrews, owl monkeys with galagos, cebus with macaques) as well as divergences are documented. All weight-of tissue and weight-of-segment variables are correlated directly with locomotor adaptation.

Adaptation, Physiological↗

Pharyngoesophageal motor function in patients with myotonic dystrophy.

Six adults with myotonic dystrophy underwent detailed radiological and manometric studies of pharyngoesophageal function. Four of the patients had no history of swallowing dysfunction, while two had very mild symptoms. All patients showed abnormalities of pharyngoesophageal function. Pharyngeal peristalsis was present but of low amplitude. Resting upper esophageal sphincter pressure was diminished, but the sphincter relaxed normally. Peristalsis in the esophageal body was invariably absent in the striated muscle segment of the esophagus and was either absent of decreased in amplitude in the smooth muscle segment. The lower esophageal sphincter was normal. Myotonia did not occur in the sphincters or the esophageal body. These findings suggest that pharyngoesophageal dysfunction is common in patients with myotonic dystrophy, even when clinical symptoms are absent. The abnormalities are probably related to muscle weakness rather than to myotonia in the pharyngeal and esophageal musculature.

Adult↗

Absorptive and motor function of orthotopically vascularized segmental ileal autografts.

In 24 dogs a 100 cm length of terminal ileum was autografted as an orthotopically vascularized Thiry-Vella segment. In six dogs absorption, motility and histology were studied in detail and in two intestinal myo-electrical activity was recorded. At a second operation 5 weeks after autotransplantation the Thiry-Vella segment was returned to its normal anatomical position in the intestinal stream and 2 months later all the non-transplanted intestine was resected. Eighteen grafts were technically successful. Intestinal myo-electrical activity was normal by the second day after transplantation while intestinal transit and contractile activity recovered within 10 days. Mucosal morphology and intestinal absorption had largely recovered by 10 days after grafting but absorption of oleic acid was impaired for 4 weeks. Ten dogs with severe short, bowel syndrome but intact ileocaecal valve were maintained in good health for more than 7 months by a 100 cm ileal autograft.

Animals↗

Human neural stem cell transplants improve motor function in a rat model of Huntington's disease.

The present study investigated the neuroanatomical and behavioral effects of human stem cell transplants into the striatum of quinolinic acid (QA)-lesioned rats. Twenty-four rats received unilateral QA (200 nM/microl) injections into the striatum. One week later, rats were transplanted with stem cells derived from human fetal cortex (12 weeks postconception) that were either 1) pretreated in culture media with the differentiating cytokine ciliary neurotrophic factor (CNTF; n = 9) or 2) allowed to grow in culture media alone (n=7). Each rat was injected with a total of 200,000 cells. A third group of rats (n=8) was given a sham injection of vehicle. Rats transplanted with human stem cells performed significantly better over the 8 weeks of testing on the cylinder test compared with those treated with vehicle (P < or = 0.001). Stereological striatal volume analyses performed on Nissl-stained sections revealed that rats transplanted with CNTF-treated neurospheres had a 22% greater striatal volume on the lesioned side compared with those receiving transplants of untreated neurospheres (P = 0.0003) and a 26% greater striatal volume compared with rats injected with vehicle (P < or = 0.0001). Numerous human nuclei-positive cells were visualized in the striatum in both transplantation groups. Grafted cells were also observed in the globus pallidus, entopeduncular nucleus, and substantia nigra pars reticulata, areas of the basal ganglia receiving striatal projections. Some of the human nuclei-positive cells coexpressed glial fibrillary acidic protein and NeuN, suggesting that they had differentiated into neurons and astrocytes. Taken together, these data demonstrate that striatal transplants of human fetal stem cells elicit behavioral and anatomical recovery in a rodent model of Huntington's disease.

Animals↗

Myosin subfragment-1 is fully equipped with factors essential for motor function.

The sliding velocity of actin filaments propelled by chicken skeletal myosin subfragment-1 (S1) was measured when the tail end of S1 was specifically bound to the glass surface. To achieve the specific binding, a regulatory light chain was replaced by a recombinant fusion protein of biotin-dependent transcarboxylase (BDTC) and chicken gizzard smooth muscle regulatory light chain (cgmRLC). The BDTC-cgmRLC of S1 was then attached to the glass surface using a biotin-avidin system. The velocity of actin filaments caused by S1 bound to the surface in this manner was 6.8 +/- 0.6 microm/sec at 29 degrees C, which was 3.5-fold greater than that (1.9 +/- 0.3 microm/sec) when bound directly to the surface as in previous studies, but similar to that caused by native chicken skeletal myosin (6.5 +/- 0.6 microm/sec). The actin-activated Mg-ATPase activity was similar to that of S1 before the RLC of S1 was exchanged for BDTC-cgmRLC. The results indicate that S1 can produce a normal fast movement of actin filaments as well as hydrolyse ATP and generate force.

Animals↗

Important role of junctophilin in nematode motor function.

Junctional complexes between the plasma membrane and endoplasmic/sarcoplasmic reticulum are shared by excitable cells and seem to be the structural ground for cross-talk between cell-surface and intracellular ionic channels. Our current studies have identified junctophilins (JPs) as members of a novel transmembrane protein family in the junctional membrane complex. Biochemical and gene-knockout studies have suggested that JPs contribute to the formation of the junctional membrane complex by spanning the intracellular store membrane and interacting with the plasma membrane. We report here invertebrate JPs in fruit fly and nematode. Three distinct JP subtype genes are found in the mammalian genome, while a single JP gene exists in either invertebrate genome. Mammalian and invertebrate JPs share characteristic structural features, although some intervening sequences are found in invertebrate JPs. A reporter assay indicated that the JP gene is predominantly activated in muscle cells in nematode. Nematodes, in which expression of JP was inhibited by RNA-mediated interference (RNAi), showed hypolocomotion. Taking account of the cell-type-specific expression and data from previous reports, the hypolocomotion is likely to be due to the deficiency of junctional membrane structures and the resulting reduction of Ca(2+) signaling during excitation-contraction coupling in muscle cells.

Animals↗

Neuronal cholecystokinin, gastrin-releasing peptide, neurotensin, and beta-endorphin in the intestine of the guinea pig. Distribution and possible motor functions.

The guinea-pig intestine was found to harbor nerve fibers containing immunoreactive cholecystokinin (CCK), gastrin-releasing peptide (GRP), neurotensin or beta-endorphin. Such fibers occurred in the myenteric and submucous ganglia and in the smooth muscle. GRP- and CCK-fibers, in addition, were found in the mucosa. Following colchicine treatment, neuronal perikarya in the myenteric ganglia displayed CCK-, GRP-, or beta-endorphin immunoreactivity. CCK-immunoreactive perikarya were located also in the submucous ganglia. Neurotensin-immunoreactive cell bodies could not be detected. The presence of immunoreactive neuronal perikarya in intramural ganglia indicates that CCK-, GRP- and beta-endorphin-containing fibers are intrinsic to the gut wall. GRP, neurotensin, and beta-endorphin were identified in extracts of smooth muscle by immuno-chemical and chromatographic analysis. CCK-8, GRP and neurotensin contracted the isolated taenia coli. Tetrodotoxin reduced the response to CCK-8 but not that to GRP and neurotensin, suggesting that the two latter peptides act directly on smooth muscle receptors. The effect of CCK-8 is partly mediated by cholinergic nerves, since not only tetrodotoxin but also atropine greatly reduced the CCK-8-induced contractile response. The substance P (SP) antagonist, (D-Pro2, D-Trp7,9)-SP1-11 had no effect on the CCK-8-induced contraction of the taenia. CCK-8 enhanced the SP-mediated (atropine-resistant) contractile response to electrical stimulation but not that mediated by acetylcholine. beta-Endorphin had no effect on the tension of the muscle but reduced the response to electrical stimulation (cholinergic as well as SP-mediated) through a naloxone-sensitive mechanism. While CCK-8 and beta-endorphin seem to play neuromodulatory roles in the taenia coli, the significance of GRP and neurotensin remains enigmatic.

Animals↗

Effect of aging on the deglutitive oral, pharyngeal, and esophageal motor function.

Aging affects some members of the swallowing orchestra and spares the others. It seems that changes in the pharynx of the elderly are more of a positive nature than a negative one and reflect an adaptation to age-induced structural changes of the upper esophageal sphincter. In the esophagus, the positive change in deglutitive peristaltic amplitude and duration seem to revert to a negative one over the age of 90 years. In the upper esophageal sphincter, it appears that aging reduces the resting pressure, but spares its response to various stimuli. Considering the increasing elderly population and their medical needs, further normalcy data about various manometric aspects of deglutition is needed for physiologic studies as well as diagnostic and therapeutic purposes.

Adult↗

Disordered gastric motor function in diabetes mellitus.

The application of novel investigative techniques has demonstrated that disordered gastric motility occurs frequently in diabetes mellitus. Gastric emptying is abnormal in about 50% of diabetic patients and delay in gastric emptying of nutrient-containing meals is more common than rapid emptying. The blood glucose concentration influences gastric motility in diabetes. In IDDM patients, gastric emptying is retarded during hyperglycaemia and may be accelerated by hypoglycaemia. Gastroparesis therefore does not necessarily reflect irreversible autonomic neuropathy and blood glucose concentrations must be monitored when gastric motility is evaluated in diabetic patients. There is a poor relationship between gastric emptying and gastrointestinal symptoms and the mechanisms by which abnormal motility causes symptoms are unclear. The introduction of new gastrokinetic drugs has improved therapeutic options for the management of symptomatic patients with gastroparesis considerably. The contribution of disordered gastric emptying to poor glycaemic control is unclear, but the demonstration that the rate of gastric emptying is a major factor in normal blood glucose homeostasis suggests that this is likely to be significant.

Diabetes Complications↗

Esophageal motor function and response to acid perfusion in patients with symptomatic reflux esophagitis.

There is much evidence to suggest that peristaltic function is defective in esophagitis patients and that this defect may contribute to prolonged acid exposure, promoting esophageal mucosal injury. Abnormal peristalsis may also be related to the generation of reflux symptoms. We evaluated primary peristalsis and its relationship to symptoms under basal conditions and during saline and HCl perfusion in 15 symptomatic reflux patients with gross esophagitis and 15 healthy controls. In the basal state, LES pressure (15.3 vs 25.1 mm Hg) and peristaltic amplitude (74.2 vs 104.8 mm Hg) were significantly lower in subjects with gastroesophageal reflux disease (GERD) (P less than 0.05). During HCl perfusion, peristaltic amplitude and duration increased slightly, and peristaltic velocity slightly decreased similarly in both groups. There was no difference in the incidence of nonpropagated, segmental, or swallow-initiated simultaneous contractions, or change in resting intraesophageal pressure during HCl perfusion in control and GERD groups. This study identified abnormal contractile amplitude as a specific defect in the primary peristaltic wave of esophagitis patients but does not support a role for acid-induced motility changes in the generation of symptoms in GERD.

Adult↗