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PubMedDate not supplied

A passive-discrete water sampler for monitoring seepage.

This paper presents the design of the passive-discrete water sampler (PDWS) which has been developed to facilitate investigations of flow partitioning in fractured rocks. The PDWS continuously isolates seeping water into discrete samples while monitoring the seepage rate. The PDWS was used in a flow and transport experiment that investigated fracture-matrix interactions. During the experiment, a mix of conservative tracers with significantly different diffusion coefficients (lithium bromide [LiBr] and pentafluorobenzoic acid [PFBA]) was introduced along a fault located in fractured tuffs, and water seeping through the lower end of the fault was collected by the PDWS and analyzed for tracer concentrations. Preliminary results from this investigation show that samples of effluent captured by the PDWS effectively retained temporal changes in the chemical signature, while providing seepage rates.

Benzoates↗
PubMed1996

Dictyostelium discoideum contains three inositol monophosphatase activities with different substrate specificities and sensitivities to lithium.

The small ion lithium, a very effective agent in the treatment of manic depressive patients, inhibits the mammalian enzyme inositol monophosphatase, which is proposed as the biological target for the effects of lithium. In this study we investigated Dictyostelium discoideum inositol monophosphatase activity. Partial purification of the proteins in the soluble cell fraction using anion-exchange chromatography revealed the presence of at least three enzyme activities capable of degrading inositol monophosphate isomers. The first activity was similar to the monophosphatase found in mammalian cells, as it degraded Ins(4)P, Ins(1)P and to a lesser extent Ins(3)P, was dependent on MgCl2 and inhibited by LiCl in a uncompetitive [corrected] manner. The second enzyme activity was specific for Ins(4)P; the enzyme activity was not dependent on MgCl2 and not inhibited by LiCl. The third monophosphatase activity degraded especially Ins(3)P, but also Ins(4)P and Ins(1)P; increasing concentrations of MgCl2 inhibited this enzyme activity, whereas LiCl had no effect. In vivo, LiCl induces a reduction of inositol levels by about 20%. In [3H]inositol-labelled cells LiCl causes a 6-fold increase in the radioactivity of [3H]Ins(1)P, a doubling of [3H]Ins(4)P and a slight decrease in the radioactivity in [3H]Ins(3)P. These data indicate that the biological effects of lithium in Dictyostelium are not due to depletion of the inositol pool by inhibition of inositol monophosphatase activity.

Animals↗
PubMed1976

[Formation, by gamma irradiation, of RNA-protein cross-links in E. coli ribosomes].

Gamma irradiation in desaerated conditions of E. coli MRE 600 ribosomes, labelled with C14 uracil, leads to a decrease of extractibility of C14 RNA by lithium chloride 4 M-urea 8 M. On the other hand, the radioactivity of the protein fraction increases with irradiation. These results strongly suggest that RNA-protein cross links are formed in irradiated ribosomes.

Bacterial Proteins↗
PubMed1975

[Use of lithium fluoride in clinical dosimetry. Application to the measurement of the dose delivered to axilla by iridium 192 with endocurietherapy for carcinoma of the breast].

The aim of the work was the evaluation of the dose delivered to the axilla during endocurietherapy for carcinoma of the breast using Iridium 192. The position of the radioactive material with respect to the axillary zone differing with the patient seated or lying, the authors carried out an vivo dosimetric study using Lithium fluoride. They refer to the chief properties of Lithium fluoride which render it the dosimetric agent of choice for clinical work and give details of their experimental conditions, stressing the problems encountered in practice (response in relation to dose, mass of thermoluminescent powder to use, fading, regeneration etc.). They then describe the technique used for placing the thermoluminescent dosimeter in the axillary zone adjacent to the target volume irradiated. Results concerning 43 patients made possible the establishment of a significant correlation between the dose delivered to the axillary region and the site of implantation of the radioactive material in the breast, and show that, with identical tumour doses, this dose is little dependent upon the structure of the radioactive implant itself. They conclude that the dose delivered to the axillary region is of the order of 25% of the tumour dose if the radioactive implant is localised in the axillary tail, 10% if it is in the upper outer quadrant and negligeable if it is elsewhere.

Breast Neoplasms↗
PubMed1976

Lithium induced alterations in rat ganglionic lipids.

Superior cervical ganglia from normal or lithium fed rats were incubated in vitro with [U-14C]pyruvic acid, in Krebs-Ringer solution with or without lithium ion. Acute lithium incubations were performed on ganglia from normal rats with 25 mEquiv./l of lithium ion, while chronic incubations were performed on ganglia from lithium fed rats with 0.5 mEquiv./l lithium in the bathing solution. Lipids were extracted, separated by thin layer chromatography and specific activities of individual lipids and their fatty acids determined. In control ganglia shinogolipids contained 60-70% of the lipid radioactivity, glycerophospholipids 20-30% and neutral lipids 10-25%. Phosphatidylcholine contained 65% of the glycerophospholipid label and 40% of the lipid phosphorus, while sphingomyelin contained 90% of the sphingolipid label and exhibited the highest specific activity over all. Cholesterol was the major neutral lipid. Niety-five per cent of the glycerophospholipid label and 4% of the sphingomyelin label was localized in the fatty acids. The lipid and fatty acid compositions of all ganglia were similar. However the lipid radioactivity in chronic ganglia was lower than in control, with the sphingolipids most affected. In 80 min stimulated chronic ganglia stearic and oleic acid, radioactivity was depressed with respect to both control fatty acids and to the [14C]palmitate of chronic tissues. In both chronic and acute lithium ganglia stimulated for 80 min, the specific activities of phosphatidylinositol were significantly lower than in control. In contrast to control, the labeling of sphingolipids in resting acute ganglia was higher than in stimulated tissues.

Animals↗
PubMed1988

Maturation-related gene expression of rat astroblasts in vitro studied by two-dimensional polyacrylamide gel electrophoresis.

Maturation of rat astroblasts was induced in vitro by acidic fibroblast growth factor (aFGF), hydrocortisone and dibutyryl cyclic AMP. Cells grown for 20 days were treated for 48 h and labelled with [35S]methionine only during the last 18 h of treatment. Cell proteins solubilized in lithium dodecyl sulfate were submitted to two-dimensional polyacrylamide gel electrophoresis. About 300 radioactive proteins could be analysed visually and compared. All treatments induced visible quantitative and sometimes qualitative changes. A total of 81 proteins had their rate of biosynthesis modified. For some proteins, this rate was changed by only one treatment, while for others it was changed by two or even by the three treatments, mostly in the same way. These results are consistent with the hypothesis that the proteins involved in the maturation process are organized in sets, proteins belonging to one set always being regulated together under a common control. Some sets would be regulated by only one effector while others would be regulated by several effectors.

Animals↗
PubMed2002

The use of the Monte Carlo simulation technique for the design of an H*(10) dosemeter based on TLD-100.

The thermoluminescence (TL) detector material LiF:Mg,Ti (TLD-100) and appropriate filter materials were combined in order to design a passive dosemeter measuring the operational quantity ambient dose equivalent, H*(10), for monitoring low-dose external photon radiation fields. Using the Monte Carlo simulation technique, optimisations of energy dependent conversion coefficients from air kerma free-in-air compared to ICRU and ISO proposed values. h*K(10), were performed by varying dosemeter detector positioning. geometrical arrangements, and filter materials. Deviations smaller than 5% compared to h*K(10) between 30 keV and 2.5 MeV of primary photon energies were achieved by a dosemeter design consisting of a 15 microm Sn metal layer and a 5 mm PMMA layer surrounding the LiF detector. Subsequently performed free-air verification experiments carried out in well defined standard photon radiation fields showed an obviously TL-specific effect. An underestimation up to -15% of the modelled data at low photon energies was observed.

Air Pollutants, Radioactive↗
PubMed1990

Effects of drugs on blood-brain barrier permeability in rats chronically intoxicated by ethanol.

Male Wistar rats were divided in free choice conditions into heavy-drinkers consuming greater than 3.5 g/kg of ethanol daily (HD), and light-drinkers consuming less than 2.0 g/kg/day (LD). Subsequent 30 day intragastric administration of 25% ethanol (8-11 g/kg/day) caused an increase in permeability of the BBB to 14C-tyrosine, 14C-tryptophan and 14C-DOPA at all the stages of alcoholization. At late stages of intoxication (20-30 days) the penetration of horseradish peroxidase (HRP) indicating pinocytosis was present. All the changes were more pronounced in LD than in HD rats. Disulfiram, and to a lesser extent phenazepam and diazepam, when repeatedly injected (for 16-30 days) together with ethanol aggravated its effects. Clonidine and haloperidol antagonized ethanol-induced increase of the BBB permeability to labelled compounds and HRP in the two groups of rats. Picamilon, lithium oxybutyrate, chlorpromazine and alpha-tocopherol had little effect on the penetration of radioactive tracers but effectively antagonized the penetration of HRP. The other drugs were without effects on the BBB regulatory and barrier functions altered by chronic alcoholization. In view of the BBB dysfunction in chronic alcoholics the adequacy of the above-mentioned drugs for their treatment is discussed.

Alcohol Deterrents↗
PubMed1981

Stimulation of Ca2+ uptake and protein phosphorylation in tumor cells by fibronectin.

Suspensions derived from attached HeLa cells transported 45Ca2+ considerably faster than those derived from spinner cultures grown in liquid medium. Incubation of spinner cells with fibronectin or cold-insoluble globulin in the presence of 5% calf serum at 37 degrees C for 1 to 2 h greatly increased the rate of Ca2+ flux into the cells. Suspensions of cells transformed by Rous sarcoma virus transported Ca2+ much more slowly than cell suspensions of the parent strain of normal rat kidney. Incubation of the transformed cells or Ehrlich ascites tumor cells with fibronectin increased the rate of Ca2+ uptake, while no effect was seen on Ca2+ transport by this treatment of normal kidney cells grown in tissue cultures. A 45,500-dalton protein was found to interact firmly with Ca2+ that entered into attached HeLa cells or fibronectin-treated spinner cells. This Ca2+-associated protein was detected by lithium dodecyl sulfate gel electrophoresis at 0 degrees C after 30 s of exposure to radioactive Ca2+. In tumor cells without fibronectin treatment, the radioactive band was not seen under the same conditions, even after 10 min incubation with 45Ca2+. In fibronectin-treated tumor cells, addition of Ca2+ to buffered solutions resulted in increased phosphorylation of a protein in the 45,000-dalton region. The phosphorylated protein band which appears to be associated with the cytoskeleton can be resolved by isoelectric focusing into four polypeptide chains. The relation of these observations to the cascade of protein kinases involved in the phosphorylation of the beta-subunit of the (Na+-K+)-ATPase is discussed.

Animals↗
PubMed1986

Direct measurement of the influx of sodium in frog skeletal muscle.

When a frog's sartorius is immersed in sodium-free lithium-substituted solution at 0 degree C, the tissue sodium content declines in two distinct phases. The rate of the slow phase has a temperature dependence expected for a process dependent on metabolism (Q10, ca. 3), and sodium content (51.5 mmol/kg dry weight) equal to that measured by others using electron microprobe microanalysis. The rate of the rapid phase has a temperature dependence (Q10, 0.3-1) expected for a passive process, and a sodium content equal to that in the sorbitol space. It was concluded that incubation of a muscle at 0 degree C for 45 min in sodium-free solution will wash out almost all of the sodium in the extracellular space but will leave almost all the sodium in the intracellular space. The unidirectional sodium influx was measured by incubating a muscle in 22Na-containing Ringer's solution for a timed interval at 23 degrees C, then in sodium-free lithium-substituted solution at 0 degree C for 45 min, before analysis for ion content and radioactivity. The ratio of the specific activity of sodium in the muscle to that in the radioactive bathing solution was calculated, and the time course of its rise was used to calculate an influx rate coefficient. The use of the specific activity minimizes the error due to the loss of intracellular sodium and radiosodium which occurs during the wash in cold solution. It was found that the rate of the radiosodium uptake varied as the uptake proceeded, in a manner similar to that previously shown for the rate of the radiosodium efflux and attributed to the existence of a diversity of cell size in this muscle.

Animals↗
PubMed1986

Collagen synthesis by murine bone marrow cell culture.

Collagen types synthesized by murine bone marrow cells were studied and the effect of lithium chloride on collagen biosynthesis in vitro was investigated. In the liquid culture system used, an adherent, mixed cell population supports hemopoiesis. Radioactive labeling of cell cultures and subsequent fractionation with ammonium sulfate, enzyme digestion, immune precipitation, and gel electrophoresis indicated that the bone marrow cells synthesized precursors to collagen types I, III, and IV, and fibronectin. A previously undescribed molecule or fragment with an apparent molecular weight of 17,000 daltons that was susceptible to bacterial collagenase and containing no interchain disulfide bonds was also identified in the culture media of both control and lithium-treated cells. Lithium treatment did not affect the types of collagen synthesized, although the relative proportions of collagen types may differ from controls. However, lithium does have an effect on the appearance of some, as yet unidentified, non-collagenous components in the cell culture media.

Animals↗
PubMed1985

Synthesis of the alpha and beta subunits of coupling factor 1 by polysomes from pea chloroplasts.

Washed thylakoids of pea chloroplasts, containing tightly bound polysomes, incorporate radioactive amino acids into protein when supplied with soluble factors from Escherichia coli. Polyacrylamide gel electrophoresis with lithium dodecyl sulfate, followed by autoradiography of the labeled products, showed the synthesis of a number of different polypeptides. Two of the most heavily labeled products were in the region expected for the alpha and beta subunits of coupling factor 1, at 57 and 54 kDa. Positive identification of the subunits was made using monospecific antibodies. Furthermore, the same two polypeptides made by soluble polysomes located in the chloroplast stroma were found. While the major proportion of the newly formed alpha and beta subunits made by thylakoid-bound polysomes remained with the thylakoids after protein synthesis occurred, no evidence was found of incorporation into complete, EDTA-extractable coupling factor 1.

Chemical Precipitation↗
PubMed1976

Isolation of the major glycoprotein from plasma membranes of an ascites hepatoma AH 66.

Plasma membranes were isolated from AH 66 cells, some of which had been labeled with [14C]glucosamine, by the following procedure: homogenization of cells which had been hardened by treatment with Zn ions, fractionation of the homogenate by sucrose density gradient centrifugation and purification of the membranes by partition in an aqueous two-phase polymer system. Polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate (SDS) of the plasma membranes and subsequent staining of the gel for protein and carbohydrate, and determination of radioactivity on the gel eluates indicated the presence of at least 10 bands of glycoproteins. The major band contained 27% of the total radioactivity incorporated into the plasma membranes and was most heavily stained with the periodate-Schiff reagent. To isolate the major glycoprotein, the membranes were solubilized with 0.6 M lithium diiodosalicylate containing 0.5% Triton X-100, then the solution was treated with phenol. The major glycoprotein, obtained in the aqueous phase, was further purified mainly by repeated chromatographies on Sepharose 6B. The purified preparation was practically homogeneous on SDS-polyacrylamide gel electrophoresis, as judged by radioactivity determination and by carbohydrate staining, but contained small amounts of carbohydrate-free proteins. The major glycoprotein had an apparent molecular weight of 160,000, as determined by SDS-polyacrylamide gel electrophoresis. The final preparation contained about 44% carbohydrate on a weight basis, and the carbohydrate moiety was composed of glucosamine, galactosamine, galactose, mannose, fucose, and sialic acid. This composition indicates that the major glycoprotein contains both N- and O-glycosidically linked oligosaccharide moieties.

Amino Acids↗
PubMed1979

An improved method for the measurement of red cell survival using non-radioactive chromium.

An improved technique for the measurement of red cell survival is described in which non-radioactive 50Cr is used in patients for whom radioactive labels are not advisable. The 50Cr was measured by neutron activation analysis using a high resolution germanium (lithium) diode gamma-ray spectrometer. In adult controls, the values obtained were in the range accepted as normal for the 51Cr method, and double labelling experiments showed close agreement. The application of this technique to the measurement of red cell survival in pregnant women suspected of having haemolytic anemia is described.

Adolescent↗
PubMed1984

Characterization of the cholinergic stimulation of phosphoinositide hydrolysis in rat brain slices.

The stimulation of the formation of inositol phosphates by various cholinergic agonists and antagonists was studied in rat brain cortical slices. Incubation of the slices with [3H]inositol led to the incorporation of radioactivity into inositol lipids. The accumulation of inositol phosphates was then followed in the presence of 8 mM lithium which blocks the hydrolysis of inositol phosphate. The release of inositol phosphate was linear up to 15 min when stimulated by 1 mM carbachol. Acetylcholine, muscarine, and methacholine also stimulated the release of inositol phosphates with about the same efficacy as carbachol. Oxotremorine, arecoline, pilocarpine, and bethanechol were not as effective as carbachol at stimulating the accumulation of inositol phosphates. Indicative of partial agonist activity, oxotremorine and pilocarpine inhibited the maximal response induced by carbachol. Muscarinic antagonists atropine, scopolamine, and pirenzepine blocked the stimulation by acetylcholine in contrast to nicotinic antagonists, which had no effect. The brain regional response to carbachol-stimulated inositol phosphate release varied widely with large responses observed in the striatum, cerebral cortex, and hippocampus. Smaller responses were seen in the brainstem, hypothalamus, and cerebellum. Although carbachol stimulated inositol phosphate release in cortical slices in the absence of added calcium, EGTA completely blocked the response. These results suggest that the previously characterized stimulation of the incorporation of 32Pi into phosphatidylinositol by cholinergic agonists in synaptosomes (Fisher, S. K., P. D. Klinger, and B. W. Agranoff (1983) J. Biol. Chem. 258: 7358-7363) is due to the initial hydrolysis of inositol lipids.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylcholine↗