Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0268318 (ICP)
 10,007 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Vanadate-dependent peroxidase A.n.I, the main isoenzyme (M(r) = 100 kDa) from the seaweed, Ascophyllum nodosum, contains 2 V per enzyme molecule (as shown by ICP-MS metal analysis) after complete reconstitution with vanadate (V), possibly distributed in a 1:1 ratio between the surface and active site. VO2+ is only weakly associated to the surface of A.n.I. There is no transport channel for VO2+. The EPR spectrum of the reduced holoenzyme is anisotropic (axial) already at room temperature, with EPR parameters similar to those of VO2+ complexes of small model peptides such as Ala-His, Gly-Tyr, Gly-Ser, Gly-Glu, Ser-Gly and Phe-Glu. The complex formation between Ala-His and H2VO4- in water has also been investigated (by 51V NMR); the formation constant at pH 7.2 amounts to 266(28) M-1.
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PMID:(Model) studies on vanadate-dependent bromo/iodoperoxidase from Ascophyllum nodosum. VO2+ is not incorporated into the active site. 131 46

Based on the recent development of analytical methods, sensitive systems for the analysis and speciation of selenium and arsenic have been established. A palladium addition technique was developed for the accurate determination of selenium in biological samples using graphite furnace atomic absorption analysis. For the speciation of the elements, combined methods of HPLC either with ICP-AES or with ICP-MS were found to work well. These systems were applied to the elucidation of the chemical form of the elements in natural samples. Some chemical properties of the selenium-mercury complex in dolphin liver were elucidated: i.e., it was a cationic, water-soluble, low molecular weight compound containing selenium and mercury in a 1:1 molar ratio, and was shown to be different from a known selenium-mercury complex, bis(methylmercuric)selenide. The major selenium compound excreted in human urine was revealed to be other than any of those previously identified (TMSe, selenate, and selenite). TMSe, a suspected major metabolite in urine, was found, if at all, in low levels. The major water-soluble, and lipid-soluble arsenic compounds in a brown seaweed, U. pinnatifida (WAKAME), were rigorously identified, and the results were compared with other data on marine algae and animals. The major organic arsenic compounds (termed "arseno-sugars") in marine algae commonly contain 5-deoxy-5-dimethylarsinyl-ribofuranoside moiety. There are various kinds of arseno-sugar derivatives containing different side-chains attached to the anomeric position of the sugar, and the distribution of each arsenic species seems to be related to algal species. The arseno-sugar (A-XI) is present in every alga so far examined, is metabolized to lipids, and possibly may play some specific role in the algal cells. On the other hand, the major arsenic compound in fish, crustacea and molluscs has been identified as arsenobetaine, which is an arseno-analog of glycinebetaine, a very common osmo-regulator in living organisms. Arsenobetaine is not detected in marine algae while arseno-sugars are not present in marine animals except for some molluscs which contain both compounds in considerable amounts. Arsenobetaine is present in the urine of human beings who have eaten foods derived from marine animals.
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PMID:Selenium and arsenic in biology: their chemical forms and biological functions. 144 44

The digestive gland of the western rock lobster, Panulirus cygnus, was shown to contain phosphatidylarsenocholine and a phosphatidyldimethylarsinylriboside by HPLC ICP-MS examination of lipid materials rendered water-soluble by hydrolysis. Water-soluble arsenic material in the digestive gland was chiefly arsenobetaine but the deacylated analogue of the phosphatidyldimethylarsinylriboside and an unidentified compound were also present.
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PMID:Arsenic lipids in the digestive gland of the western rock lobster Panulirus cygnus: an investigation by HPLC ICP-MS. 152 2

The diffusive permeability to water molecules, Pd, of lipid vesicles with entrapped paramagnetic solute ions can be determined rapidly from analysis of the magnetic field dependence (nuclear magnetic relaxation dispersion, or NMRD profile) of T1 of exterior solvent water protons. Such data yield tau, the mean lifetime of solvent molecules inside the vesicles, from tau = (fT1Para) - T1Ves, where f is the volume fraction of entrapped water, T1Para is the observed T1 corrected for buffer background, and T1Ves is the relaxation time of water protons in the entrapped solution. For small spherical unilamellar vesicles of inner radius R, Pd = R/3 tau, f can be obtained accurately from knowledge of both the concentration of Gd(DTPA)2- in the solution in which the vesicles were formed and the average concentration of ions in the final sample. At low temperatures, in the limit of slow exchange, T1Para becomes independent of field and tau = fT1Para; the observation of a field-independent profile is a control that confirms that no paramagnetic material is external to the vesicles. We have measured T1Para, using a field-cycling relaxometer, for suspensions of POPC (1-palmitoyl-2-oleoyl-lecithin) vesicles with 100-500 mM entrapped Gd(DTPA)2- and membrane concentrations of cholesterol ranging from 0 to 40 mol %. These profiles, which span the field range 0.01-50 MHz proton Larmor frequency, were taken at 5, 15, 25, and 35 degrees C. Concentrations of Gd(DTPA)2- were determined independently by both ICP analyses and NMRD methods. Values for Pd for vesicles with 100 mM Gd(DTPA)2- and outer diameters 100 nm +/- 20%, as determined by quasielastic light scattering, are 63, 47, 24, 16, and 8.7 x 10(-4) cm s-1, at 25 degrees C, for cholesterol concentrations of 0, 10, 20, 30, and 40%, respectively. The corresponding activation enthalpies are 14, 14, 14, 17, and 17 kcal/M. Comparison with 2H NMR studies of deuterated POPC vesicles with no cholesterol at 20 degrees C, and with 10% at 40 degrees C, which yielded the same order parameter for the palmitoyl acyl chains, gives no indication of a correlation between order parameter and permeability.
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PMID:Permeability of liposomal membranes to water: results from the magnetic field dependence of T1 of solvent protons in suspensions of vesicles with entrapped paramagnetic ions. 154 42

A new version of the direct injection nebulizer (DIN) is used to interface liquid chromatographic (LC) separations with element-selective detection using inductively coupled plasma mass spectrometry (ICP-MS). The DIN injects all of the sample into the ICP and has a dead volume of less than 1 microliter. Charged species of arsenic and tin are separated as ion pairs on a micro-scale (1 mm i.d.), packed, reversed-phase column. Detection limits are 0.2-0.6 pg for arsenic and 8-10 pg for tin. For methanol + water eluents, the signal is highest at 25% methanol and stays within 25% of this maximum as the methanol fraction is varied from 20 to 80%. Compared with LC-ICP-MS with conventional nebulizers, the absolute detection limits and chromatographic resolution are substantially superior, and the dependence of analyte signal on solvent composition is somewhat less severe with the DIN.
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PMID:Elemental speciation by liquid chromatography-inductively coupled plasma mass spectrometry with direct injection nebulization. 158 Apr 4

The feline infusion model of brain edema was used to evaluate the role of bradykinin in the etiology and pathophysiology of vasogenic brain edema. Bradykinin (3 or 90 ug in 600 microL saline) did not alter normocapnic regional cerebral blood flow (rCBF) nor induce specific changes in either the somatosensory (SEP) or motor (MEP) evoked potentials. The mean increases in ICP (from 4.5 to 16.1 mmHg) and peri-infusion white matter water content (from 69.4 to 79.8 ml/100 g tissue), mean decrease in lumped craniospinal compliance (from 0.040 to 0.014 ml/mmHg) and local histological changes were all similar to those after 600 microL saline infusion. The interstitial bradykinin infusion caused focal blood-brain-barrier (BBB) opening to Evans Blue dye and was chemotaxic for granulocytes. After the infusion there was a global loss of rCBF CO2 reactivity but there was no ischemia at normocapnia. These results show that bradykinin in brain edema fluid, at concentrations greater than those found in neuropathological conditions, can open the BBB of normal cerebral parenchymal capillaries and cause vascular dysregulation. In neuropathological conditions bradykinin may therefore potentiate formation of vasogenic brain edema but does not contribute to perilesional brain dysfunction.
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PMID:The role of bradykinin in the etiology of vasogenic brain edema and perilesional brain dysfunction. 159 96

ICP control can be achieved removing the surgical masses and manipulating the intracranial compartments; in the intensive care setting that can be attempted using CSF withdrawal or changing the cerebrovascular resistances, the intracranial blood content and the cerebral water content. The reduction of the ICP and the maintenance of a good cerebral perfusion pressure are the main aims of the therapy; when any standard treatment fails to control ICP a further attempt to preserve cerebral perfusion should be done by increasing the mean arterial pressure. In 10 patients with severe brain damage (GCS on admission ranging from 3 to 7, mean 5) from subarachnoid hemorrhage (3 cases) or trauma an infusion of dopamine (25-150 mg/h) and noradrenaline (0.4-2.4 mg/h) was started in case of intractable ICP. The ICP was defined intractable when the pressure was more than 40 mmHg for more than 5 m' after maximum therapy, as evaluated using the Therapy Intensity Level score. The infusion obtained a raise of the MAP of approximately 25% and a variable response on ICP. In 9 cases ICP dropped, in one case, instead, the ICP increased together with the arterial pressure. The reduction of ICP was 20-30%, with a good improvement of the CPP. The patients with a good response survived, the only patient without control of the ICP died. The physiopathologic mechanisms of this treatment are discussed; the most suitable explanation is indicated in an autoregulatory process. The infusion of cathecolamines can be harmful, and the patients eligible for this treatment must be carefully chosen. Notwithstanding this approach deserves further studies for the cases of intractable ICP.
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PMID:[Increasing the pressure of cerebral perfusion to control intracranial pressure]. 162 Apr 43

Arachidonic acid solution (2 to 15 mg/ml) was infused into the right forebrain white matter of anaesthetised cats over three hours to evaluate its contribution to the genesis and pathophysiology of vasogenic brain oedema. The 0.6 ml infusion increased local white matter water content by a mean of 11.3 ml/100 g tissue but did not increase cortical water content. Histological studies revealed local expansion and trabeculation of the white matter with aggregations of granulocytic neutrophils in the venules and perivenular brain. The adjacent cortical cytoarchitecture was normal. The white matter around the infusion site was stained lightly and over a variable area (15-20 mm2) by intravenously administered Evans Blue dye 2%. Regional cerebral blood flow (rCBF) adjacent to the frontal infusion did not change significantly during the period of infusion and remained similar to rCBF in the contralateral hemisphere. Following the arachidonic acid infusion regional CBF CO2 reactivity was normal and three was no asymmetry of either cortical somatosensory evoked potential (SEP) or motor evoked potential (MEP) waveforms. The increase in brain water content and changes in the ICP and ICP related biodynamics (pressure-volume index, lumped craniospinal compliance and CSF outflow resistance) were similar to those seen following infusion of 0.6 ml saline. These studies suggest that free intraparenchymal arachidonic acid, at concentrations exceeding those occurring in most neuropathological conditions, can increase the normal brain parenchymal capillary permeability but does not disrupt focal cerebrovascular and electrophysiological function. The clinical implications of these findings are discussed.
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PMID:The contribution of arachidonic acid to the aetiology and pathophysiology of focal brain oedema; studies using an infusion oedema model. 166 51

During 2 days of an offshore drilling operation in the North Sea, 16 airborne dust samples from the atmosphere of the Shale Shaker House were collected onto filters. During this operation, drilling mud composed of a water slurry of barite (BaSO4) together with minor amounts of additives, among them chrome lignosulphonate and chrome lignite, was circulated between the borehole and the Shale Shaker House. The concentration of airborne dust in the atmosphere was determined and the elemental composition of the particles analysed by both PIXE (proton-induced X-ray emission) and ICP-MS (inductively coupled plasma-mass spectrometry). The total amount of dust collected varied from 0.04 to 1.41 mg m-3 with barium (Ba) as the single most abundant element. The open shale shakers turned out to be the major cause of generation of dust from the solid components of the drilling mud.
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PMID:Elemental composition of airborne dust in the Shale Shaker House during an offshore drilling operation. 176 13

Water samples were collected from 384 waterworks that supply 70.9% of the Norwegian population. The samples were collected after water treatment and were analysed for 30 constituents. Although most constituents show wide concentration ranges, Norwegian drinking water is generally soft. The median values obtained are: 0.88 mg Si l-1, 0.06 mg Al l-1, 47 micrograms Fe l-1, 0.69 mg Mg l-1, 2.9 mg Ca l-1, 3.8 mg Na l-1, 6 micrograms Mn l-1, 12 micrograms Cu l-1, 14 micrograms Zn l-1, 9 micrograms Ba l-1, 15 micrograms Sr l-1, 0.14 mg K l-1, 58 micrograms F- l-1, 6.4 mg Cl- l-1, 11 micrograms Br- l-1, 0.46 mg NO3- l-1, 5.3 mg SO4(2-) l-1, 2.4 mg TOC l-1, 6.8 (pH), 5) microseconds cm-1 (conductivity) and 11 mg Pt l-1 (colour). Titanium, Pb, Ni, Co, V, Mo, Cd, Be and Li were seldom or never quantified, due to insufficient sensitivity of the ICP (inductively coupled plasma) method. Norwegian quality criteria, which exist for 17 of the constituents examined, are generally fulfilled, indicating that the chemical quality of drinking water, by and large, is good in Norway. For Fe, Ca, Mn, Cu, pH, TOC and colour, however, the norms for good drinking water are exceeded in more than 9% of the samples, reflecting two of the major problems associated with Norwegian drinking water supplies: (i) many water sources contain high concentrations of humic substances; (ii) in large parts of the country, the waters are soft and acidic, and therefore corrosive towards pipes, plumbing and other installations. Most constituents show marked regional distribution patterns, which are discussed in the light of different mechanisms contributing to the chemical composition of drinking water, namely: chemical weathering of mineral matter; atmospheric supply of salt particles from the sea; anthropogenic pollution (including acid precipitation); corrosion of water pipes and plumbing; water treatment; decomposition of organic matter; and hydrological differences.
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PMID:A nation-wide survey of the chemical composition of drinking water in Norway. 203 65


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