Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0432222 (SEM)
 47,337 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Histochemistry, SEM-EDX and X-ray fluorescence analysis were applied to detect the distribution of iron, arsenic and other related elements in the pulmonary tissues of tin miners in Yunnan. Lesions obtained in human beings could be reproduced in rats subjected to intratracheal injection of arsenic containing ore dust, which was prepared in order to study the deposition, dissociation and release of inhaled less-soluble arsenic containing ors dust in the lungs and the process of development of different ferruginous bodies. Data obtained in the pulmonary tissues provided also the evidence about the role of arsenic as the etiological factor of lung carcinoma in the tin miners of Yunnan province.
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PMID:[Study of deposition and translocation of mineral dust in lungs of tin miners in Yunnan by X-ray microanalysis]. 149 71

Nickel-chromium alloys were plated with tin and chromium to evaluate the effect on porcelain shear bond strength. Six plating methods were used. Additionally, the microstructure of the bond between the plated alloy and porcelain were studied using SEM and EPMA. Tin plating increased the bond strength of porcelain to a nickel-chromium alloy while chromium plating did not.
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PMID:The bond strength of porcelain to Ni-Cr alloy--the influence of tin or chromium plating. 152 49

In rats allowed to eat for only 2 h per day, gastric emptying of three different meals [poached egg white, glucose (0.5 kcal/ml) and physiological saline, each labelled with 60 MBq of technetium-99m tin colloid visualized using a gamma camera] was markedly slowed 8 h after the last meal. Mean body weight in rats on the restricted feeding schedule was 80% of the weight of free-feeding controls. Gastric emptying curves for all three meals in controls were best described using loge transformed counts. Other models used were linear and square root. For each of the three meals, the percentage remaining in the stomach at 120 min was estimated using linear regression of gastric contents, transformed if necessary to yield the best curve against time. At 120 min, % gastric contents (mean +/- SEM) were 19.5 +/- 5.6 (egg), 15.5 +/- 6.27 (glucose) and 27.1 +/- 7.48 (saline) in control rats. After 4 months restriction, the corresponding figures were 75.2 +/- 4.04, 81.5 +/- 4.75 and 70.3 +/- 5.83. After 3 months of free feeding, emptying rates of the three meals were not significantly different from control values. We conclude that dietary restriction causes profound changes in gastric emptying by unknown mechanisms which may be operating in patients with anorexia nervosa.
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PMID:Dietary restriction delays gastric emptying in rats. 236 15

We measured the concentrations of chromium, cesium, and tin in the cerebrospinal fluid (CSF) of 29 patients with brain tumors [21 benign (BBT) and eight malignant (MBT)], 28 leukemic patients, 14 patients with lymphoma or noncerebral solid tumors (NLCT), and 32 control patients (15 with neurological disorders and 17 with noneurological conditions) by use of flameless atomic absorption spectrophotometry. We detected chromium in 94% of the patients, tin in 79%, and cesium in 50%. The mean (and SEM) concentrations (micrograms/L) of these metals in the control group were 4.7 (1.1) for chromium, 3.8 (1.6) for cesium, and 6.4 (1) for tin. We observed significant differences (P less than 0.05) in the concentration of chromium in CSF between the MBT group and all other tumor groups; the ratios for the mean CSF concentration of chromium in patients with BBT, leukemia, or NLCT to that in patients with MBT were 2.6, 2.1, or 4.4, respectively. We saw no significant differences in the concentrations of cesium or tin among the various groups investigated.
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PMID:Concentrations of chromium, cesium, and tin in cerebrospinal fluid of patients with brain neoplasms, leukemia or other noncerebral malignancies, and neurological diseases. 337 24

Studies were performed on seven conscious dogs chronically instrumented for measurement of subendocardial segment length in the central area perfused by the left circumflex coronary artery (LCCA) and left anterior descending coronary artery, LCCA flow, and left ventricular pressure. We occluded the LCCA for 2 min using an externally inflatable pneumatic occluder placed around the proximal LCCA. Two-minute LCCA occlusions were repeated hourly for 8 h, 5 days/week. The first LCCA occlusion decreased the ejection phase shortening in the ischemic area from 22.2% +/- 2.5% (SEM) to 3.1% +/- 0.7% (P less than 0.001). Concomitantly, heart rate increased from a resting rate of 76 +/- 4 to 117 +/- 6 beats/min (P less than 0.001) after 2 min of LCCA occlusion, and ejection phase shortening in the nonischemic area decreased from 25.5% +/- 1.3% to 21.6% +/- 1.1% (P less than 0.001) despite increases in end-diastolic segment length (15.31 +/- 1.46 mm to 15.69 +/- 1.52 mm, P less than 0.01). These changes in non-ischemic segment shortening and heart rate during LCCA occlusion were attenuated progressively with improvement tin the regional myocardial function at jeopardy due to the development of collateral circulation, and a significant (P less than 0.001) correlation between both the reduced nonischemic segment shortening and the increased heart rate with the degree of dysfunction in the ischemic region was obtained by linear regression analysis with Fisher's Z transformation.
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PMID:Characterization of nonischemic segment shortening during variable extent of myocardial ischemia in conscious dogs. 344 Jul 79

A sample of 165 extracted or exfoliated teeth containing amalgam restorations were categorized as to the degree of marginal integrity of the amalgam. Microstructures of the samples representing the highest (grade 11) and lowest (grades 1 and 2) degrees of marginal deterioration were studied by SEM/EDS. The clinical evaluation and microscopic evaluation indicated that samples showing poor marginal integrity contained large quantities of tin-rich and tin-chlorine-rich corrosion products with little or no gamma-2 phase remaining. Obvious signs of fracture and cracking at the cavosurface were always present. Products containing calcium were extensively associated with corrosion products containing tin, and these were found predominantly at the tooth-amalgam interface. No copper-rich amalgams were found in this grouping. Amalgams with good marginal integrity had no microscopic cracks or fractures and generally little evidence of corrosion was found. However, one of six samples had extensive corrosion products, indicating that corrosion product formation is not the only factor contributing to marginal deterioration. After 6 years of clinical use, the degree of marginal deterioration did not appear to depend unerringly on time of use. Further work is necessary to define the microstructural characteristics of samples showing intermediate amounts of marginal deterioration and to determine if copper-rich amalgams consistently have small to moderate amounts of marginal deterioration.
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PMID:Characteristics of amalgam restorations with variable clinical appearance. 385 63

Radiographic contrast media (CM) (meglumine/sodium diatrizoate-76%; 1650 mOsm/kg) and other hypertonic solutions induce renal vasoconstriction by an unknown mechanism. In anesthetized dogs, renal blood flow (RBF) was measured with an electromagnetic flowmeter and filtration fraction (FF) and glomerular filtration rate (GFR) by the renal extraction of technetium-99m tin chelate. Ureteral pressure (UP) and wedged renal venous pressure (VP) were measured as indices of intrarenal pressure. Measurements of renal length (L), along with pressures, made it possible to examine the compliance of the system. A 4-cc intrarenal bolus of CM caused a 59% reduction in GFR (control: 0.63 +/- 0.04 to 0.26 +/- 0.04 ml/min X g, mean +/- SEM), in association with a 23% reduction in RBF (control: 3.10 +/- 0.11 to 2.39 +/- 0.26 ml/min X g) and a 44% decrease in FF (control: 0.32 +/- 0.01 to 0.18 +/- 0.03). These responses were compared with a 3-microgram intrarenal bolus of norepinephrine (NOREPI) which resulted in a 79.0 +/- 7.5% reduction in RBF, 68.3 +/- 7.3% reduction in GFR and 42.6 +/- 15.6% increase in FF. The NOREPI-induced vasoconstriction caused transient decreases in renal L, UP, and VP, whereas the CM-induced decrease in renal blood flow was associated with increases in these parameters. In studies employing ureteral occlusion to elevate intrarenal pressure, the magnitude (area, cm2) of the CM-induced decrease in renal perfusion was accentuated with increased UP (r = 0.79, n = 24, P less than 0.001). The CM-induced increase in renal L, UP, and VP must reflect osmotic forces and an increase in intrarenal pressure. The decreases in FF and GFR probably reflect Starling forces in the glomerular capillaries, with osmotic transients dominating. The results suggest a mechanical mechanism for the CM-induced decrease in RBF.
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PMID:Mechanism of the renal response to contrast medium in dogs. Decrease in renal function due to hypertonicity. 683 34

The typography of polymethyl methacrylate processed against various gypsum products coated with various separating materials was studied under an SEM. Tinfoil and two commercial tin foil substitutes were used as separating material during processing, and the surfaces of the resulting acrylic resin forms were studied for topographical differences. Tinfoil and alpha 2 hemihydrates produced the smoothest surfaces. As a practical solution, a good quality tinfoil substitute and alpha 1 hemihydrate could be used when processing polymethyl methacrylate resin.
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PMID:The effect of gypsum products and separating materials on the typography of denture base materials. 693 Dec 20

This investigation studied the effects of abrasion and salivary contamination on the shear bond strength of a composite resin bonded to tin-plated gold alloy. Experimental groups (n = 15) consisted of: group 1, no surface treatment; group 2, enamel abraded; and group 3, saliva-contaminated. After surface stressing and bonding, groups were thermocycled before shear testing. Fractured interfaces were analyzed by use of light microscopy and SEM. Specimens in group 3 (12.2 +/- 2.5 MPa) had significantly lower bond strengths than group 1 (17.9 +/- 6.8 MPa). The shear bond strengths of resin bonded to tin-plated metal were significantly affected by salivary contamination but not by abrasion.
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PMID:Influence of saliva contamination and abrasion on resin to tin-plated alloy bond strengths. 767 79

The successful application of thrombolytic therapy to acute myocardial infarction has prompted a reinvestigation of thrombolytic therapy for acute stroke. However, an examination of safety and efficacy of thrombolytic therapy in acute thromboembolic stroke has precluded the entry of patients taking either antiplatelet or anticoagulant therapy. It was therefore of interest, in an established rabbit model of thromboembolic stroke, to examine the use of tissue plasminogen activator therapy in combination with ticlopidine treatment. Following ticlopidine administration (10 mg kg-1, i.v., daily for 5 days), rabbits (n = 7) were embolized by injecting a tin-laden clot into the internal carotid artery with clot placement confirmed by x-ray. Three hours later, t-PA was initiated as a square-wave pulse (6.3 mg kg-1 total dose, given as a 20% bolus, with the remainder administered over 2 h as a continuous infusion). The protocol was continued for a total of 7 h following embolization. Complete clot lysis was demonstrated in 6 of 7 animals. Brain infarct size (triphenyltetrazolium chloride staining) was 36.0 +/- 12.9% hemisphere (mean +/- SEM). Both clot lysis rate and infarct size were very similar to that previously seen following administration of t-PA alone (58% and 31.6 +/- 6.4% hemisphere, respectively) but in marked contrast to previous results seen with intravenous aspirin (no clot lysis). These results suggest that antiplatelet agents used clinically for stroke prophylaxis (aspirin or ticlopidine) may influence the success rate of thrombolysis following initiation of thrombolytic therapy for acute thromboembolic stroke.
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PMID:Combination tissue plasminogen activator and ticlopidine therapy in a rabbit model of acute thromboembolic stroke. 871 36


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