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Query: UMLS:C0851184 (thinning)
 11,252 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Blood acetylcholinesterase (ACHE) and pseudocholinesterase (PCHE) activity and urinary dialkyl phosphate (DAP) excretion were measured in a group of 15 male agriculture field workers during a five-day thinning operation in a Northern California peach orchard. Eight men were randomly assigned to work in a Guthion-treated plot, and seven men to work in an adjoining plot free from organophosphate residues. Foliage samples were taken to measure dislodgeable and total Guthion residues. The daily mean percent change in the ACHE and in the PCHE activity was less than -10.0 percent of baseline values for each group of men. Mean ACHE activity of workers in the Guthion treated plot was different from that of workers in the control plot on the fifth exposure day. The mean PCHE activity of workers in the Guthion treated plot was not different from that of workers in the control plot. Daily group-mean urinary metabolite excretion levels for workers exposed to Guthion residues were highly correlated with their daily group-mean percent change in ACHE activity. No urinary metabolites were detected in workers in the control plot. Decay in Guthion residues was markedly slower in this trial than in a comparable study conducted one year previously, emphasizing the difficulty in setting re-entry intervals based on time elapsed from pesticide application. Suggestions were made to extend the time interval of future studies on the human health effects of organophosphate residue exposure, and to further refine urinary metabolite surveillance methods toward the goal of establishing a threshold level of metabolites which would correspond to meaningful exposure to these pesticides residues.
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PMID:A controlled field trial of physiological responses to organophosphate residues in farm workers. 73 28

The surfactant delmopinol, which is a new antiplaque agent with a low anti-microbial profile, was tested for its effects on the viscosity of bacterial extracellular glucans. Glucans were isolated from Streptococcus mutans broth supernatants incubated with 0.15 M sucrose in 50 mM sodium phosphate buffer at pH 6. The viscosity was measured in a shear rate range from 15 to 230 reciprocal seconds. The viscosity of the water-soluble glucan was found to be independent of shear rate whereas the water-insoluble glucan showed a strong shear thinning. The addition of delmopinol to preformed glucans did not affect the viscosity nor the shear rate dependence of the glucans. However, when present during synthesis of the polysaccharides, delmopinol was found to reduce the viscosity of both water-soluble and water-insoluble glucans by approximately 50% at the shear rates investigated. The reduction in viscosity for the water-soluble glucans was obtained at a delmopinol concentration of 0.32 mM (0.01%) and for the water-insoluble glucans at 3.2 mM delmopinol. The observed reduction of viscosity of glucans indicates that the in vivo stability of plaque matrix after delmopinol treatment would be lowered, which may lead to a reduction of plaque cohesion and thus facilitate mechanical plaque removal.
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PMID:Effect of delmopinol on the viscosity of extracellular glucans produced by Streptococcus mutans. 142 43

The permeability of subepithelial capillaries in porcine endometrium was studied during midcycle and early pregnancy. Gilts were slaughtered on Day 13 or Day 15 of the oestrous cycle or pregnancy, 15 min after injection through the ear vein of 11.1 MBq of 125I-labelled human albumin in phosphate-buffered saline. The radioactivity of endometrial strips taken along the mesometrial and antimesometrial aspects of the uterine horn varied on average from 270 to 701 c.p.m./g and no difference (P greater than 0.05) was found between reproductive status, days of slaughter or sampling sites. The majority of the subepithelial capillaries showed ultrastructural evidence of increased vascular permeability, such as marked thinning of the capillary walls, especially on the side proximal to the epithelial basal lamina, multilayering and partial disparition of the endothelial basal lamina and abundant endothelial vesicles. Fenestrated pores were observed, but were rare. There was no obvious difference between reproductive status, days of sampling or sampling sites inside the uterus, suggesting that on Days 13-15 after oestrus the ultrastructural characteristics of porcine endometrial capillaries are little affected by the presence of attaching blastocysts and supporting the results obtained with radioactive albumin. Ferritin injected directly into a uterine artery of one gilt on Day 15 of pregnancy was carried through the capillary wall by endothelial vesicles, showing ultrastructural evidence of increased permeability.
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PMID:Structural and functional aspects of porcine endometrial capillaries on days 13 and 15 after oestrus or mating. 155 88

Two case reports from a high fluoride (10 ppm) rural community. They presented with severe degrees of dental fluorosis, hyper-sensitivity of teeth and skeletal fluorosis all arising from the ingestion of high amount of fluoride in water over a long period of time. Both cases had deformities of the upper and lower limbs. However, the deformities were more pronounced in the lower limbs than in the upper limbs, resulting in knock knee. Radiological finding showed osteosclerosis of the axial bones while the appendicular bones exhibited osteoporosis. There was marked change of bone structure observed as osteomalacia, and course trabecular bone pattern. Osteoporosis was also associated with cortical thinning. Periosteal bone apposition was observed in the bones: and genu valgum of the limbs. Biochemical tests revealed normal values for serum calcium and inorganic phosphate. However, the serum alkaline phosphatase was elevated. This may be an indication of a pathological condition where there are possible compensatory mechanisms to maintain normal levels of serum calcium and inorganic phosphate. One case which had undergone corrective surgical intervention of the lower limbs four years earlier, had continued to live in the same environment using drinking water with 10 ppmF after corrective surgery, and showed no improvement.
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PMID:Skeletal and dental fluorosis: two case reports. 191 81

Growth plate cartilage from normal and vitamin D-phosphate deficient (-VDP) rats was cultured to study the production of collagenase and tissue inhibitor of metalloproteinases (TIMP) in vitro. All tissues secreted latent collagenase into the medium at a constant rate during the 5 days in culture. Microdissected-VDP growth plates, containing predominatly hypertrophic cells, released up to 8-fold more collagenase into the medium than either intact-VDP or normal growth plates. TIMP was also secreted during the culture, but its rate of production was not as dependent on tissue type as collagenase. The tissue level of collagenase and TIMP before culture was compared with that found in conditioned medium and remnant tissue after culture. During the 5 day culture period microdissected-VDP growth plates, containing predominatly hypertrophic cells, produced 3-times more collagenase/microgram DNA over the starting level than either intact-VDP or normal growth plates. TIMP was never found in tissues after they had been cultured, but was present in all tissues before culture except those containing predominatly hypertrophic cells. The amount of TIMP required to block collagenase was calculated. Growth plates in culture produced enough TIMP to block all collagenase found in the medium and remnant tissue, while extracts of uncultured intact -VDP growth plates, and those divided to contain hypertrophic cells, had an excess of collagenase over TIMP. The results suggest that hypertrophic cells produce far more collagenase than other cells in the growth plate, but all cell types have about the same capacity to synthesize TIMP. As a result, increased collagenase synthesis by hypertrophic cells may surpass increases in TIMP synthesis and lead to collagen removal. This would allow for thinning of the longitudinal septa and expansion of the hypertrophic cells.
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PMID:Production of collagenase and tissue inhibitor of metalloproteinases (TIMP) by rat growth plates in culture. 196 14

Isolated rat heart preparations were studied to characterise the alterations in high energy phosphates that occur during reversible regional ischaemia and to determine whether pyruvate, as the sole exogenous energy substrate, would attenuate the ischaemia induced depletion of the nucleotide pool when compared with glucose. Using phosphorus-31 magnetic resonance spectroscopy baseline concentrations of adenosine triphosphate, phosphocreatine, inorganic phosphate, and intracellular pH were compared with values during 30 min of left coronary artery occlusion followed by 30 min of reperfusion. These variables were related to changes in developed pressure, coronary flow, and oxygen consumption. In addition, the total nucleotide pool was evaluated by biochemical analysis of myocardial tissue extracts and coronary effluent. The ischaemic region was characterised by a dye staining technique and cross sectional echocardiographic measurements of regional myocardial wall thinning. In both glucose and pyruvate perfused groups, coronary flow and oxygen consumption decreased to 50-60% of control within 1 min of ischaemia and returned to baseline values with reflow. Developed pressure decreased to 50(9) and 74(8)% (mean(SEM] of control after 30 min of ischaemia in glucose and pyruvate perfused groups respectively. Reperfusion resulted in complete recovery of developed pressure in hearts perfused with pyruvate but not in the glucose group. Glucose perfused hearts had a greater decrease in intracellular pH during ischaemia (7.07(0.01) to 6.36(0.1] than pyruvate perfused hearts (7.06(0.02) to 6.83(0.04]. Reperfusion resulted in a rapid return to baseline intracellular pH in both groups. During ischaemia, adenosine triphosphate values decreased to a greater degree in glucose than in pyruvate perfused hearts (57(4) and 79(5)% of baseline respectively). Thirty minutes of reperfusion did not significantly improve adenosine triphosphate concentrations in either group. Phosphocreatine concentrations decreased to 52(7) and 75(6)% of baseline in glucose and pyruvate perfused groups respectively after the ischaemic period. Reperfusion resulted in normalisation of phosphocreatine values in the pyruvate but not in the glucose perfused group. Biochemical analysis of myocardial tissue extracts confirmed the spectroscopy data and showed that pyruvate inhibits the efflux of adenine nucleotide derivatives. Tissue concentrations of adenosine monophosphate were three times greater and adenosine 50% less after 30 min of ischaemia in the pyruvate perfused group.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Substrate regulation of the nucleotide pool during regional ischaemia and reperfusion in an isolated rat heart preparation: a phosphorus-31 magnetic resonance spectroscopy analysis. 316 43

Cardiac depression in the isolated rat heart perfused with 4% ethanol was correlated with intracellular phosphate energetics and tissue water distributions. Energy metabolites were assessed using 31P magnetic resonance spectroscopy (MRS) and correlated to the mitochondrial redox state using epicardial surface fluorometry. Changes in myocardial water compartmentation were measured by using 1H NMR spectroscopy with an extracellular chemical-shift reagent (DyTTHA) and correlated to results of 2D echocardiography (2DE). During alcohol perfusion there was a significant decrease in developed pressure and in coronary flow. No change was seen in ATP, PCr, pHi, Pi, or NADH. After withdrawal of alcohol from the perfusate cardiac function reverted to control values without a depletion of energy levels. During alcohol perfusion 1H MRS showed a marked redistribution of water from the intra- to the extracellular space, corresponding to a 35% left ventricular wall thinning confirmed by 2DE. The results indicate that acute alcohol cardiac depression is related to a dehydration of myocardial cells, but is not associated with intracellular acidosis or energy depletion.
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PMID:31P and 1H magnetic resonance spectroscopy of acute alcohol cardiac depression in rats. 317 69

Proton NMR imaging of myocardial ischemia without infarction requires the use of paramagnetic contrast agents. Even during the first few hours of infarction, imaging without contrast enhancement reveals only slight natural image contrast. Myocardial infarction, however, is much more readily detected during the first few days and weeks post coronary occlusion; this is due to a marked elevation in T2 during this time period. Chronic infarction, several months after the acute event, does not demonstrate altered signal intensity, but can be detected by visualizing myocardial wall thinning and aneurysm formation. Information regarding high energy phosphate metabolism can be acquired in vivo in ischemic animal preparations; preliminary data has demonstrated that it is possible to acquire similar information noninvasively in man. Development of this technique will eventually permit the study of pharmacological and mechanical interventions aimed at preserving myocardium in the ischemic heart. Exogenous labelling of myocardial tissue with carbon-13 permits the study of the effects of substrates on cellular metabolism. Ultimately, the technique of chemical shift imaging will provide a method of spatially resolving valuable metabolic information in the form of an NMR image. Eventually, with the gradual development of NMR technology, imaging and spectroscopy will become truly important clinical tools in the investigation of ischemic heart disease in man.
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PMID:Evaluation of myocardial ischemia and infarction by nuclear magnetic resonance techniques. 328 14

The relative time courses of early changes in myocardial metabolism and function during anoxia, global ischemia, and regional ischemia were compared in isolated rat hearts. Transmural anoxic wave front was determined with NADH fluorescence photography, and oxygen saturation of myoglobin and dynamic systolic wall thickening were measured with spectrophotometry of light transmitted through the left ventricular free wall. In all three treatments, anoxic wave front first appeared in the subendocardium and reached the epicardial half of the myocardium in 10 s, when oxygen saturation of myoglobin decreased by 50% and tissue ATP and creatine phosphate remained at aerobic levels. During this period, systolic wall thickening decreased gradually in anoxia and global ischemia, whereas a marked decrease in systolic wall thickening and appearance of dyskinesia (wall thinning) occurred in regional ischemia. Thus the early extension of anoxic wave front and metabolic changes are similar with all three treatments, and dyskinesia, observed only in case of regional ischemia, occurs when the inner half is ischemic or anoxic.
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PMID:Transmural anoxic wave front and regional dysfunction during early ischemia. 361 98

Women with primary biliary cirrhosis malabsorb calcium, phosphate and vitamin D, and develop accelerated cortical bone thinning. We have assessed the value of parenteral vitamin D, oral hydroxyapatite (HA), and calcium gluconate (CG) in the treatment of cortical bone thinning in primary biliary cirrhosis. Sixty-four postmenopausal women with primary biliary cirrhosis were assigned randomly into three groups: one group receiving no mineral supplements (control), one group receiving HA, and one group receiving CG. All patients received parenteral vitamin D2 (100,000 IU monthly). Eleven patients withdrew from the study and 10 withdrew due to poor compliance (six HA, four CG). Over a 14-month follow-up period, none of the groups showed a significant change in serum calcium or inorganic phosphate levels. Pre- and posttreatment hand radiographs were used to assess changes in metacarpal cortical thickness using the technique of caliper radiogrammetry. Cortical bone loss occurred in the control group (p less than 0.01). The HA group showed a significant gain in cortical bone thickness (p less than 0.01), while no significant change occurred in the CG group. This study indicated that vitamin D2 does not halt metacarpal cortical bone thinning in primary biliary cirrhosis. The addition of CG prevents bone thinning, and HA promotes positive cortical bone balance.
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PMID:Vitamin D, hydroxyapatite, and calcium gluconate in treatment of cortical bone thinning in postmenopausal women with primary biliary cirrhosis. 628 35


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