Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P50583 (asymmetrical)
 12,197 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effect of behavioral activation on cerebral and cerebellar glucose metabolism was studied in normal subjects when performing either a verbal memory task or a tactile somatosensory task. Each subject was also studied in a resting state control condition, either 1 h earlier or later than the activation task. Compared to the resting state, both tasks produced asymmetrical metabolic activation, which was opposite in direction within the cerebral and cerebellar hemispheres. In both tasks, the difference of activation of CMRglc in the right and left hemispheres in the cerebellum was negatively correlated with that in the sensory-motor region. This apparently coupled metabolic activation of one cerebellum and areas within the opposite cerebral hemisphere represents the inverse of the crossed cerebellar diaschisis phenomenon commonly observed when a vascular lesion affects one cerebral hemisphere and hypometabolism occurs in the opposite cerebellum. Because these correlations were selective and concordant with known anatomical connections, and were found in two different tasks, they suggest strong functional connections between these specific brain regions.
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PMID:Cerebrocerebellar relationship during behavioral activation: a PET study. 198 4

Two seemingly contradictory sets of observations have been made in studies of biological transport, which are essential for our understanding of the transport mechanism: carriers are integral membrane proteins, which span the membrane and are not free to rotate across the membrane; carriers appear to function like a ferryboat, with a substrate binding site moving back and forth from one side of the membrane to the other. To reconcile these facts, it is necessary to postulated gated channels connecting the substrate site with the two membrane surfaces: the channels are arranged so that as one opens the other closes, with the result that the substrate site is alternately accessible from opposite sides of the membrane. Based on these properties, the following distinguishing features of molecules specifically bound in the channels may be predicted: if sufficiently bulky, they inhibit transport; they bind outside the substrate site (though adjacent to it), they bind asymmetrically either to the outward-facing carrier and on the outer surface of the membrane, or to the inward-facing carrier and on the inner surface of the membrane. The asymmetrical inhibition of the glucose and choline transport systems of erythrocytes by various inhibitors is examined, and the behavior in every case is found to conform with these criteria. From the results it may be concluded that the glucose carrier binds cytochalasin B in the inner gated channel and phloretin and tetrathionate in the outer gated channel.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Looking for probes of gated channels: studies of the inhibition of glucose and choline transport in erythrocytes. 243 6

Glycogen and free-glucose content in the ventral, central and dorsal parts, as well as glucose-6-phosphate phosphatase activity in mantle of Mytilus galloprovincialis Lmk. were examined. The glycogen content of mantle did not manifest asymmetrical distribution among the three parts. In the period studied, the typical glycogen content profile variation was found, being maximum in July. The tissue free-glucose content was similar in each part, and the obtained seasonal variation profile was opposite to the glycogen content, reaching the minimum in July. For every part of mantle, free-glucose/glycogen ratio showed similar monthly profiles. In each part the 50% point was found in July. Glucose-6-phosphate phosphatase activity was not found in the mantle tissue.
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PMID:[Zonal variability and seasonal changes of the content of glycogen and glucose in the Mytilus mantle]. 254 90

Lesions of one cerebral hemisphere are associated with decreased glucose metabolism, oxygen metabolism, and blood flow in the contralateral cerebellar hemisphere. We used positron emission tomography to look for a functional relationship in cerebral metabolism between the cerebral cortex and the contralateral cerebellum in normal human subjects. Twenty-four normal subjects were scanned with [18F]fluoro-2-deoxy-D-glucose while in a resting state. Asymmetry in local CMRglu (LCMRglu) in the frontal cortex was strongly correlated with asymmetry in LCMRglu in the opposite direction in the cerebellar hemispheres (r = -0.60, p less than 0.001). Widespread subregions of the frontal cortex were found to contribute to this relationship. Considering these results together with previous studies demonstrating that frontal lesions are associated with decreased metabolism in the contralateral cerebellum, we conclude that the frontal cortex exerts a strong modulating influence on metabolism in the contralateral cerebellum in normal subjects, and that this influence may be asymmetrical.
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PMID:A relationship between metabolism in frontal lobes and cerebellum in normal subjects studied with PET. 326 82

Acromegaly involves cardiovascular complications mostly due to the presence of hypertension, diabetes and atherosclerosis. However the appearance of cardiac decompensation and arrhythmias in the absence of predisposing factors tends to support the hypothesis of a specific myocardiopathy caused by excess GH. In order to assess the existence and course of subclinical cardiac alterations, 8 acromegaly patients were examined: 4 males and 4 females aged 31-56 with GH levels of 24-70 ng/ml (M + CD X 47 +/- 16) and no cardiovascular symptoms. One of the patients had moderate hypertension and 2 reduced glucose tolerance. The basal ECG showed sporadic ventricular extrasystoles in 2 cases and alterations compatible with left ventricular hypertrophy in another, while the effort ECG produced an asymptomatic depression of the ST segment in the hypertensive patient. The chest X-ray was normal in all cases. The echocardiography study investigated: the thickness of the interventricular septum (IVS = 13.9 +/- 2.8 mm), the thickness of the posterior wall of the left ventricle (LPW = 10.6 +/- 2.9 mm), the septum/posterior wall ratio (IVS/LPW = 1.3 +/- 0.2 the diastolic diameter (DD = 15.4 +/- 11.4 mm), the fraction of shortening (FS = 39.1 +/- 14.5%), the ejection fraction (EF = 64.1 +/- 18.4%) and revealed asymmetrical septal hypertrophy in 3 cases, concentric hypertrophy in another two. In two cases the DD and EF were distinctly altered. The patients were re-examined 2-4 years after surgical or radiation treatment. GH levels (M +/- SD = 10.3 +/- 10.1 ng/ml) were normal in 4 cases and still high, though lower in another two. The remaining two patients had borderline GH levels with high Sm-C. The ECG and chest X-ray were unchanged while echocardiography revealed a significant deterioration in heart function as far as DD (56.4 +/- 10.8 mm, p less than 0.05) were concerned with frankly pathological results in 4 and 3 cases respectively. These data confirm the view that most acromegalic patients present subclinical abnormalities in cardiac function and that the evolution of these is slightly influenced by the reduction in GH and Sm-C. levels. In fact, while the persistence of high GH and Sm-C. levels may explain the progression of cardiac alterations in some cases, it does not in others. It is also emphasised that echocardiography appears to be the most sensitive non-invasive technique for the diagnosis and follow-up of cardiac involvement in acromegaly.
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PMID:[Cardiological findings in acromegaly]. 343 27

The transport function and orientation of the reconstituted human erythrocyte glucose transporter was studied with liposomes made with bovine brain lipid or Escherichia coli lipid. Reconstitution was achieved by a simple octyl glucoside dilution method. The reconstituted transporters with either lipid showed identical counterflow transport activity, the same response to various inhibitors, and characteristic cytochalasin B (CB) labeling. Functional location and purification of the glucose transporter was performed by using gel-permeation high-performance liquid chromatography with octyl glucoside-containing buffer. The reconstituted transport activity was associated only with band 4.5 protein (preactin) and not with band 3 protein. Both CB binding and transport function of the reconstituted transporters were resistant to trypsin but susceptible to chymotrypsin digestion. However, both trypsin and chymotrypsin treatment of unsealed ghosts completely eliminated the CB labeling and transport function of the glucose transporter. In our reconstitution system the glucose transporters maintained a normal asymmetrical (right-side-out) orientation and good transport function. A specific monoclonal antibody against the glucose transporter inhibited CB labeling of the transporters on unsealed ghosts. This was not found with the reconstituted system; however, after freeze-thawing there was a significant inhibition of CB binding by the antibody. These findings suggest that the CB-binding site of the reconstituted transporter is on the inner side of the proteoliposomes.
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PMID:Human erythrocyte glucose transporter: normal asymmetric orientation and function in liposomes. 351 73

Cats were injected with 2-deoxy- [14C]glucose (2-DG) while walking on a moving treadmill (experimental group), or sitting down on a stationary one (controls). After a 45-min equilibration period they were anesthetized, and their central nervous system (CNS) was removed rapidly and frozen. The tissue blocks were sectioned serially, and X-ray film exposed to the sections was used for quantitative densitometric analysis by Sokoloff's method. The utilization of glucose in a CNS region (LCMRg) was regarded as a measure of that region's energy metabolic activity and--indirectly--of its functional status. The walking cats exhibited significantly higher LCMRg in many but not all places of the neuraxis, compared to the control group. Also, LCMRg was symmetrical (side to side) in the control group but significantly asymmetrical in certain regions of the CNS in the experimental group. In all but one of these cats the LCMRg was greater in the right side of the gray matter of the cervical spinal cord and in the left visual and motor cortices and caudate nucleus. The finding that the motor cortex and other supraspinal regions become more active during walking suggests they may contribute to the control of locomotion and/or processing of related sensory data. The side to side asymmetry in the spinal cord and hemispheres during walking may be related to the phenomenon of lateral dominance.
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PMID:Asymmetrical regional changes in energy metabolism of the central nervous system during walking. 380 84

Hypophysectomy decreased the basal rate of glucose metabolism in segments of epididymal fat studied in vitro and lowered their maximum capacity to use glucose. However, hypophysectomy changed neither the sensitivity to insulin nor the magnitude of the response when the results were expressed relative to the basal rate of glucose metabolism. Adipocytes isolated from both hypophysectomized and normal rats exhibited a higher basal rate of glucose metabolism than cells remaining in situ in the contralateral tissues, but this consequence of cell isolation was more pronounced for adipocytes of hypophysectomized than normal rats. Glucose metabolism could not be further increased by exposure of the adipocytes of hypophysectomized rats to insulin, whereas insulin produced a 3-to 5-fold stimulation of glucose oxidation in normal adipocytes. The effects of insulin and hypophysectomy on the transport of the nonmetabolizable sugar L-[1-14C]arabinose in tissue segments and isolated adipocytes were also studied. Uptake of L-arabinose was usually more rapid in segments of epididymal fat of normal rats than in segments of tissue obtained from hypophysectomized rats and was significantly accelerated by insulin in both groups. Uptake of L-arabinose was more rapid than normal in adipocytes isolated from hypophysectomized rats and, like glucose metabolism, could not be accelerated by insulin. The same concentration of insulin markedly promoted arabinose uptake in normal adipocytes. Efflux of L-arabinose from segments of tissue from hypophysectomized rats was twice as rapid as that from normal tissue and, in contrast with the rate of efflux from normal tissues, was not accelerated by insulin. The data suggest that in the absence of pituitary secretion, sugar transport in the adipocyte membrane may be asymmetrical. The data also support the view that hypophysectomy renders adipocytes more susceptible than normal to the cell isolation procedure which maximally accelerates glucose utilization and inward transport of arabinose in these cells.
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PMID:Effects of hypophysectomy and cell isolation on the transport of L-arabinose by adipocytes. 388 May 39

Regional CMRglc (rCMRglc) values were determined with positron emission tomography (PET) in 10 patients with mild to moderate clinically diagnosed Alzheimer's disease (AD) and in 26 healthy controls. rCMRglc in frontal, parietal, and temporal association cortices were significantly more laterally asymmetrical in AD patients than in controls (p less than 0.05). Furthermore, lateral asymmetry of rCMRglc in AD patients but not in the control subjects correlated significantly with asymmetry of language and visuospatial functions such that lower left than right rCMRglc was associated with relatively greater impairment of language and vice versa. The results demonstrate that discrepancies between language and visuospatial deficits in patients with early AD are related to asymmetrical reductions in cerebral cortical glucose metabolism.
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PMID:Relations between neuropsychological and cerebral metabolic asymmetries in early Alzheimer's disease. 398 21

Clinical, electrophysiological, and electron microscopical data are presented on 10 diabetic patients with severe progressive neuropathy, predominantly motor in type, in the presence of good blood glucose control, and for one patient with painful neuropathy and third cranial nerve palsy. Endothelial cell hyperplasia was seen in small vessels in all cases, and seven patients showed plugging of the vascular lumen by degenerate cellular material and electron dense protein. It is suggested that these cells desquamate and occlude smaller peripheral vessels at a point of narrowing. In one case the lumen of a vessel was occluded by thrombus. Electron microscopical examination showed a vessel occluded by degranulated platelets. Electrophysiological studies showed a pattern of denervation that was asymmetrical and distally predominant in some patients, suggesting that the neuropathy, at least in part, relates to multiple small infarcts.
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PMID:Small vessel disease in progressive diabetic neuropathy associated with good metabolic control. 404 73


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