Deuterium Depleted Water Research Articles

Evaluation of the reversibility of iodide uptake by argillaceous rocks by the radial diffusion method

Laboratory radial in- and out-diffusion experiments were performed to investigate the reversibility of the iodide (I-) uptake by argillaceous rocks from the Tournemire site (France). At first, the suitability of the method was demonstrated by means of deuterium depleted water (DDW) diffusion experiments. The values for the DDW effective diffusion coefficient (1.7 to 2.7×10-11m2s-1) are indeed very close to those obtained from previous through-diffusion experiments carried out on Tournemire samples with tritiated water. The diffusion of chloride and bromide led to the determination of halide-accessible porosities, which are necessary to calculate the retardation factor (R) and the distribution ratio (RD). The calculated values for the halide-accessible porosity (2 to 5%) clearly indicated the effect of anionic exclusion and are consistent with previous data. On the contrary, the in-diffusion experiments performed with iodide clearly showed its uptake by argillite, with rock capacity factor values ranging from 14% to 25%. The corresponding values ofRD(0.035 to 0.08 L kg-1) are one order of magnitude lower than those previously derived from batch methods. At last, the experiments of iodide out-diffusion revealed that only iodide located in the halide-accessible porosity diffused out of the rock samples, suggesting that the uptake of iodide by argillite would not be reversible or that the kinetics of desorption would be low (>70 days).

INVESTIGATIONS CONCERNING THE VALUES OF SOME BIOCHEMICAL PLASMA COMPOUNDS IN WISTAR RATS GRAFTED IV. WITH A TRANSPLANTABLE TUMOUR (WALKER 256 ASCITIC CARCINOMA), CORRELATED WITH THE DAILY DEUTERIUM DEPLETED WATER INTAKE

SUMMARY The aim of the experiment was to prove the clinica l and paraclinical (biochemical) effects of the daily deuterium depleted water intak e on the biological behaviour of the Walker 256 ascitic carcinoma grafted intravenous (iv) in t he Wistar rats, correlated to the values of some biochemical plasma compounds, like acid phosphatase (PAC), alaninaminotransferase (ALAT, GPT, ALT), aspartataminotransferase (ASAT, GOT, AST), gammaglutamiltranspeptidase (GGT), alchaline phosphatase (PAL). The experiment was conducted on 20 Wistar rats, which were distributed in 4 groups, each group containing 5 adult animals. First of all, the animals from group 2 and 4 were administrated ad libitum daily deuterium depleted water, for a period of six month s, and then inoculated (group 4) intravenously with Walker 256 ascite liquid (85 000 ‐ 90 000 tumour cells/ml ascite liquid) obtained from the Oncologic Institute “Testioreanu” , in Bucharest. During the first stage of the experiment (1 to 6 months) for all animals were weekly determined the body weight and some clinical aspects, regarding the food and water intake, some peculiarities of the behaviour and the health status. After intravenous inoculatio n of the Walker 256 ascitic carcinoma, all animals were rigurously observed, and were weekly evaluated from the point of view of the body weight evolution, respectively of some abnormal manifestations. Finaly, the experimental groups were sacrificed after 5 weeks f rom the intravenous inoculation with Walker 256 ascite carcinoma, under narcose with ether, by cardiac punction and blood samples collecting. The obtained results at the nec hropsic examination revealed the presence of the solid tumours at the level of some lymph nod e groups, lung and liver in 3 animals out of 5 in the case of the control tumour group (group 3). In comparance to this situation, in the case of group 4 (inoculated intravenously with Walk er 256 carcinoma and which consumed the deuterium depleted water), tumours weren’t obvi ously present in any of the animals. The blood samples were centrifuged and from the obtained plasma samples, the following enzymes were determined: acid phosphatase (PAC), alaninaminotransferase (ALAT, GPT, ALT), aspartataminotransferase (ASAT, GOT, AST), gammaglutamiltranspeptidase (GGT), alkaline phosphatase (PAL). The obtained results re vealed that the values of the determined enzymes are inside the normal limits for this speci es and animal category, respectively between

Effect of deuterium-depleted water on reproduction of rainbow trout

During the artificial reproduction of salmonides, the fecundity can be increased either by improving the viability of spermatozoa, or by extending the time period during which a roe micropile remains open, thus allowing its fecundation. Practically, this can be achieved by the use of some fertilising techniques suitable for fish species. Here, we show that the reproduction of rainbow trout in a 1:1 solution of deuterium-depleted water and distilled water led to a significant increase in survival of roes during their embryonic development. Moreover, the addition of glucose and fructose into the deuterium-depleted fertilising solutions led to a further increase in roe survival during embryonic development. The increase in survival is mainly explained by an increase in the motility of spermatozoa.

Plant-Scale Method for the Preparation of Deuterium-Depleted Water

A study of the utilization of aqueous decomposition of sodium amalgam for the production of deuterium-depleted water is presented. In the framework of this work the correlation between the deuterium content of the hydrogen gas and the concentration of the aqueous alkali, both formed in the reaction of sodium amalgam with water, is established. The sodium amalgam is prepared via sodium chloride electrolysis. In addition to the formation of an industrial alkaline solution containing 50% w/w sodium hydroxide, hydrogen gas with a deuterium concentration of 50 ppm is obtained. This hydrogen gas is suitable (e.g., via combustion) for the preparation of deuterium-depleted water used, e.g., in cancer therapy.

Naturally occurring deuterium is essential for the normal growth rate of cells.

The role of naturally occurring D in living organisms has been examined by using deuterium-depleted water (30-40 ppm D) instead of water containing the natural abundance of D (150 ppm). The deuterium-depleted water significantly decreased the growth rate of the L929 fibroblast cell line, and also inhibited the tumor growth in xenotransplanted mice. Eighty days after transplantation in 10 (59%) out of 17 tumorous mice the tumor, after having grown, regressed and then disappeared. We suggest that the naturally occurring D has a central role in signal transduction involved in cell cycle regulation.

Quantitative evaluation of water content in a solid protein by deuterium NMR

A method for evaluating absolute water content in a solid protein based on deuterium NMR measurements in solution is described. By dissolving the hydrated solid protein, which has been specifically deuterium-labeled, into deuterium-depleted water and by comparing the deuterium NMR signal intensity of water (1H2HO) with that of the protein, the amount of water contained in the solid protein is evaluated quantitatively. The method requires a heat pretreatment of the protein sample in water of an enriched (e.g. 2%) deuterium composition for complete hydrogen exchange of the labile protons, and hence is applicable to a protein with a reasonably good reversibility of thermal unfolding. By utilizing this method, the absolute content of the bound water in a protein, Streptomyces subtilisin inhibitor (SSI), lyophilized for 8 h was determined to be 9.2%. The extent of hydration of solid SSI during its exposure to a deuterium-enriched water vapor could also be followed from the deuterium NMR signals in solution. In addition, solid state deuterium NMR measurements of SSI suggested that direct measurement of the natural abundance deuterium signal can give a reasonable estimate of the water content in a solid protein.

Deuterium NMR study of the interaction of phytanic acid and phytol with the head group region of a phospholipid bilayer. Evidence of magnetic orientation

Deuterium nuclear magnetic resonance ( 2H-NMR) spectra of multilamellar dispersions of 1,2-dipalmitoyl- sn-glycero-3-phospbo-[1′,2′- methylene- 2H 4]cholme(DPPC- d 4) containing 20 mol% of the isoprenoid compounds phytol or phytanic acid in excess deuterium-depleted water, or Tris buffer (pH 7.4), have been recorded over the temperature range 15–55°C. Phytol (20 mol%) causes a decrease in the residual quadrupolar splitting, Δv Q of the choline 1′-deuterons (i.e., those adjacent to the phosphate moiety) by 3%, while Δv Q of the 2′-deuterons decrease by 22%. Phytanic acid (20 mol%) reduces Δv Q of the 2′-deuterons by 43% and increases Δv Q of the 1′-deuterons by approx. 16%. First ( M 1) and second ( M 2) moments were calculated from the spectra. Plots of M 1 and m 2 versus temperature suggest phytol and phytanic acid have a significant effect on the pretransition. Spin-lattice relaxation times ( T 1) and transverse relaxation times ( T 2 e , the time constant for decay of the quadrupolar echo) have been determined over the temperature range 15–50°C. The presence of 20 mol% phytanic acid results in orientation of the DPPC bilayers in the magnetic field with the phospholipid long axes oriented perpendicular to the magnetic field as shown by 2H- and 31P-NMR. The sample must be carried through several freeze-thaw cycles in the presence of Tris buffer in order that the phospholipid magnetic field ordering occur. Possible explanations for the effect of phytol and phytanic acid on the dynamic structure of the choline head group of phospholipids in the bilayer are suggested.

Formaldehyde metabolism by Escherichia coli. In vivo carbon, deuterium, and two-dimensional NMR observations of multiple detoxifying pathways.

13C NMR has been used to demonstrate the metabolism of dilute solutions of labeled formaldehyde by Escherichia coli to methanol, formate, carbon dioxide, and several other unidentified metabolites which contain labeled CH2 groups. Aeration of bacterial suspensions within the spectrometer dramatically increased the rate of oxidation to formate and carbon dioxide. Deoxygenation with nitrogen gas virtually abolished all metabolism, as did the exposure of bacteria to very high formaldehyde concentrations. Deuterium NMR of whole cells in deuterium-depleted water further demonstrated the conversion of formaldehyde-d2 to methanol-d2, ruling out a formaldehyde dismutase as an important species. Two-dimensional proton-carbon chemical shift correlation was used to reveal the chemical shifts of the protons attached to 13C labels in metabolites. The results indicate that formaldehyde is efficiently detoxified by the bacterial cell through a route or routes which do not appear to involve tetrahydrofolate. This detoxification may be in competition with the lethal antibacterial processes associated with formaldehyde.