Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0220723 (PCA)
 4,687 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Among 39 cases with acute-onset amnestic syndrome having unilateral localized infarct, 8 cases with anteromedial thalamic infarct ("thalamic" amnesia), and 18 cases with medial temporal lobe infarct including hippocampus in the posterior cerebral artery territory ("PCA" amnesia) were studied in terms of X-CT and MRI findings and neuropsychological examinations. Results were as follows: 7 out of 8 cases with thalamic amnesia (88%), and 15 of 19 cases with PCA amnesia (78%) showed left side lesions on CT scan. All groups showed a prolonged recent memory loss with little loss of immediate recall and remote memory, and disorientation and dyscalculia. In both types of amnesia, patients having a left sided lesion showed recent memory loss with new learning disabilities of verbal materials. Patients having a right sided lesion showed recent memory loss with new learning disabilities of both verbal and visuospatial materials. Judging from the X-CT and MRI findings, the lesions most probably causing amnesia in these cases seemed to be the anterior and dorsomedial nuclei of the thalamus in thalamic amnesia and hippocampus in PCA amnesia. Differential diagnosis in amnestic syndrome with localized infarct is also discussed.
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PMID:Acute-onset amnestic syndrome with localized infarct on the dominant side--comparison between anteromedial thalamic lesion and posterior cerebral artery territory lesion. 357 4

We experienced a case of successful acute revascularization using a long vein graft. A 68-year-old man was admitted to our department due to transient ischemic attack of the left hemiparesis. CT scan showed no infarction, but PAO-SPECT revealed moderate hypoperfusion in the right ACA and MCA area. Cerebral angiography demonstrated right IC occlusion at its origin and moderate collateral circulation via leptomeningeal anastomosis from the PCA area, and via the external carotid system, especially directly from STA. But the STA was very narrow. Three days after admission, left hemiparesis appeared again and deteriorated severely. This time the hemiparesis persisted. Although MRI demonstrated little infarction in the right frontal lobe, we decided to carry out revascularization on the same day. Right saphenous vein was harvested for a graft because of the narrow STA. The facial artery and angular artery was selected as a donor and a recipient respectively, to avoid a clamp of the EC and a craniotomy of the STA running area. Finally we performed a facial artery-vein graft-angular artery (M4) bypass. The patient showed no complication and the left hemiparesis improved enough to allow the patient to walk by himself. Revascularization using vein graft is dangerous for acute ischemia due to the possibility of a complication such as brain edema and hemorrhagic infarction. The usual style of vein graft bypass is an EC-vein graft-M2 or M3 bypass. Using this style, high pressure inside the EC is carried intracranially.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[A case of successful acute revascularization using a long vein graft]. 775 28

In this study, we report the synthesis and the evaluation as MRI contrast agent of a new compound (nitroxyl fatty acid, NFA), where a pyrrolidinoxyl radical (3-carboxy-proxyl, PCA) is linked to a fatty acid moiety. Fatty acids were selected as vector because they present a high affinity for the liver, their efficient cellular uptake being the result of a specific interaction with a transmembrane transporter (liver plasma membrane-fatty acid binding protein). The uptake of 3H-oleic acid is inhibited after the injection of 1 mmol/kg of NFA, suggesting that NFA recognizes the same transmembrane transporter as the natural fatty acids. The higher relaxivity R1 of NFA in albumin solutions, compared with PCA, was explained by the immobilization of the nitroxyl radical in the protein. MR imaging was performed using T1-weighted images on mice in order to compare the contrast effect obtained after the injection of 1 mmol/kg of radical. The % signal enhancement in the liver 5 min after intravenous injection was 49 +/- 4 and 14 +/- 5 for NFA and PCA, respectively. NFA allowed a better delimitation of some necrotic tumors (Novikoff hepatocarcinoma) due to its preferential uptake by the nontumorous tissue.
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PMID:Evaluation of a nitroxyl fatty acid as liver contrast agent for magnetic resonance imaging. 825 59

CCl4 and related compounds, such as halothane, are metabolized by the liver to form free radical intermediates, which are thought to be implicated in the hepatotoxic response. Two to three hours following CCl4 exposure (i.p.) there is a localized edematous region surrounding the portal vein which is observable by proton MRI in vivo. Enhancement of the CCl4-induced edematous region was possible using Gd-DTPA, a paramagnetic contrast agent. However, with the use of a nitroxide contrast agent (3-PCA) there was no enhancement, but rather a significant diminution of the CCl4-induced edematous response. These results suggest that the nitroxide contrast agents, which are themselves free radicals, act as free radical scavengers and therefore reduce the formation of the CCl4-induced hepatic 'damage' observed in proton MR images.
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PMID:Use of nitroxides as MRI contrast agents to study in vivo carbon tetrachloride induced hepatotoxicity in rats. 828 26

A 43-year-old man was admitted to our hospital in January, 1991 for further examination of polydipsia, polyuria and hypertension. He had had a personal history of hypertension since 1976 and of diabetes mellitus since 1982. Physical examination and routine laboratory studies showed that the patient was characterized by asymptomatic hypertension in the presence of hypokalemia and increased urinary potassium excretion. Plasma aldosterone concentrations (PAC) were elevated and plasma renin activity (PRA) was suppressed, resulting in a considerable increase in the ratio of PAC to PRA. PAC was not normally suppressed by saline infusion (2 1/2h, iv). PRA remained suppressed and PAC did not rise after stimulation with iv injection of furosemide (40 mg) in combination with walking for 60 min. PAC was increased in response to ACTH injection (0.25 mg, iv) but not suppressed by dexamethasone administration (2 and 8 mg/day, po). PAC did not rise after iv infusion of angiotensin II (20 ng/kg/min for 30 min). Venous sampling showed that PAC was considerably elevated in the bilateral adrenal vein. CT and MRI demonstrated tumor mass in the bilateral adrenal gland and the remaining normal portion in the left adrenal gland. Scintigraphic imaging with 133I-aldosterol during dexamethasone suppression provided bilateral uptake in the adrenals. Oral administration of spironolactone (375 mg/day) suppressed blood pressure and elevated PRA and serum potassium. Elevated PCA and PRA levels as well as hypertension were corrected by right-total and left-subtotal adrenalectomy performed in March, 1991. However, impaired glucose tolerance was not changed after surgery, and plasma glucose levels were well controlled with a small dose of insulin (9U/day). Pathological studies revealed adrenocortical adenoma cells of clear cell type with spironolactone bodies in the bilateral adrenal tumors. These findings indicate that this is a very rare case of primary aldosteronism due to bilateral functioning adrenocortical adenomas, which is accompanied by diabetes mellitus.
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PMID:[A rare case of primary aldosteronism due to bilateral functioning adrenocortical adenomas]. 846 28

Our purpose was the study the magnetic resonance (MR) signal intensity of the perirolandic gyri perinatally and to correlate it with the histological findings in formalin-fixed brains, focusing on myelination. MRI of 20 neurologically normal neonates and infants, of 37-64 weeks postconception (PCA), were studied retrospectively. We reviewed four formalin-fixed brains of infants 37-46 weeks PCA microscopically. The posterior cortex of the precentral gyrus (P-PRE) and the anterior cortex of the postcentral gyrus (A-PST) had different signal intensity from the adjacent surrounding cortex. On T1-weighted images P-PRE and A-PST gave higher signal 41-44 weeks PCA; on T2-weighted images, they gave lower signal 37-51 weeks PCA. Histological examination revealed very little myelination of the nerve fibres within both the P-PRE and the A-PST, while considerable myelination was present in the internal capsule and central corona radiata. The changes in signal intensity in the perirolandic gyri may reflect not only the degree of myelination but also the more advanced development of the nerve cells, associated with rapid proliferation and formation of oligodendroglial cells, synapses and dendrites. They could be another important landmark for brain maturation.
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PMID:MR signal intensity of the perirolandic cortex in the neonate and infant. 888 Jul 24

A 54-year-old man was admitted to the hospital because of the restriction of the right visual field. Goldmann's visual field test revealed the right central hemianopsia. MRI showed the infarction of the left occipital lobe tip. Cerebral angiography showed the occlusion of the left calcarine artery but no abnormality in the branches of the middle cerebral artery (MCA). The occipital lobe tip receives the projection from the macular area and is supplied by both calcarine artery and a branch of MCA. Therefore, cases of central homonymous hemianopsia due to vascular disorders have been relatively rare and the macular vision is usually spared. In contrast to the above knowledge, only one artery occlusion resulted in the central hemianopsia in our case. Poor anastomosis between PCA and MCA in the occipital tip of our patient may explain occurrence of the infarction of that area.
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PMID:[A case of central homonymous hemianopsia due to cerebral infarction of the occipital tip]. 895 63

The use of the undecapeptide cyclosporine and the macrolide tacrolimus as immunosuppressants in transplantation medicine and for the therapy of immune diseases often provokes side effects, among the most important one is neurotoxicity. Changes in the cellular metabolism of glial cells (C6 rat glioma), neuronal cells (N1E-115 mouse neuroblastoma) and primary glia cells (isolated from rats) after addition of cyclosporine and tacrolimus were investigated using 1H-, 13C- and 31P-NMR spectroscopy in vitro. Cells were exposed to various concentrations of the drugs from 3 h to 42 days. The immunosuppressants (cyclosporine IC50 : 55 mumol/l; tacrolimus IC50 : 47 mumol/l) inhibited cell proliferation in a concentration- and time-dependent fashion. Multinuclear NMR studies of PCA extracts of drug-treated cells showed a significant deterioration in the energy status (a decreasing level of PCr : -46 +/- 11%; an increasing NDP/NTP ratio: +136 +/- 4% and an increasing level of Pi : +248 +/- 15%; mean +/- standard deviation). It also showed decreasing concentrations of major cell metabolites like NAA (-59 +/- 12%) in neuroblastoma cells and myo-inositol (-47 +/- 6%) in glia cells compared with untreated controls. Immunosuppressive treatment caused a large reduction of taurine (-36 +/- 12%) and glutamate (-68 +/- 10%) in all cell cultures, whereas intermediates of phospholipid biosynthesis (PE: +59 +/- 13%; PC: +127 +/- 27%;) and breakdown (GPE: +215 +/- 24%; GPC: +245 +/- 17%) increased. No significant differences were observed between the two immunosuppressants. The toxic effects of immunosuppressants on cell cultures are in line with MRI studies of brain oedema observed in patients under immunosuppressive treatment.
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PMID:Evaluation of the effects of immunosuppressants on neuronal and glial cells in vitro by multinuclear magnetic resonance spectroscopy. 897 22

Today secondary prevention of stroke is based on large clinical trials with the disadvantage of a lack of individual pathophysiological aspects. This is mainly due to the difficulty in identifying the source of stroke reliably and rapidly in these patients. Recurrent microembolic events detected by transcranial Doppler monitoring (TCM) has been suggested to individualize treatment. We describe a patient with recurrent ischemic events in the posterior circulation. Repeated TCM of the PCA disclosed microembolic events in the course of an acute embolic lesion pattern demonstrated by MRI. Detection of high-intensity transient signals by TCM provided a useful guidance of pathophysiologically oriented treatment in this patient.
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PMID:Stroke treatment guided by transcranial Doppler monitoring in a patient unresponsive to standard regimens. 1020 11

The object of the study was to test the hypotheses that analysis of the anatomic zones affected by single anterior (A), posterior (P), and middle (M) cerebral artery (CA) infarcts, and by dual- and triple-vessel infarcts, will disclose (i) sites most frequently involved by each infarct type (peak sites), (ii) sites most frequently injured by multiple different infarct types (vulnerable zones), and (iii) anatomically overlapping sites in which the relative infarct frequency becomes equal for two or more different infarct types and/or in which infarct frequency shifts greatly between single and multivessel infarcts (potential border zones). Precise definitions of each vascular territory were adopted. CT and MRI studies from 20 ACA, 20 PCA, three dual ACA-PCA, and four triple ACA-PCA-MCA infarcts were mapped onto a standard template (Part I). Relative infarct frequencies in each zone were analyzed within and across infarct types to identify the centers and peripheries of each infarct type, the zones most frequently affected by multiple different infarct types, the zones where relative infarct frequency was equal for different infarcts, and the zones where infarct frequency shifted markedly from single- to multiple-vessel infarcts. Zonal frequency analysis provided quantitative data on the relative infarct frequency in each anatomic zone for each infarct type. It displayed zones of peak infarct frequency for each infarct, zones more vulnerable to diverse types of infarct, peripheral "overlap" zones of equal infarct frequency, and zones where infarct frequency shifted markedly between single- and multiple-vessel infarcts. It is concluded that the hypotheses are correct.
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PMID:Zonal frequency analysis of infarct extent. Part II: anterior and posterior cerebral artery infarctions. 1280 44


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