Polymorphisms and deduced amino acid substitutions in the coding sequence of the ryanodine receptor (RYR1) gene in individuals with malignant hyperthermia.

Twenty-one polymorphic sequence variants of the RYR1 gene, including 13 restriction fragment length polymorphisms (RFLPs), were identified by sequence analysis of human ryanodine receptor (RYR1) cDNAs from three individuals predisposed to malignant hyperthermia (MH). All RFLPs were detectable in PCR-amplified products, and their segregation was consistent with our initial finding of linkage to MH in the nine families previously informative for one or more intragenic markers (MacLennan et al., 1990, Nature 343:559-561). Four amino acid substitutions were identified in the study: Arg for Gly248, Cys for Arg470, Leu for Pro1785, and Cys for Gly2059. Of 45 families tested, a single family presented the Arg for Gly248 substitution where it segregated with malignant hyperthermia, making it a candidate mutation for predisposition to MH in man. The other three polymorphic substitutions failed to segregate with malignant hyperthermia in those families in which they occurred, implying that they represent polymorphisms with little or no effect on the function of the RYR1 gene.     

Computational study of radiation chemical processing in comet nuclei

Cometary nuclei have been exposed to high levels of ionizing radiation since their formation. We present here some results of a computer model calculation of the effect of ionizing radiation on cometary material. The external (cosmic rays) and internal (embedded radionuclides) contributions in the processing of cometary nuclei are considered. As a first approximation we have used the available kinetic data of the liquid water system to model the radiation effects in a frozen cometary environment. Out data suggest that massive radiation chemical processing due to cosmic rays may have taken place only in the outer layers of comets. The internal contribution of radionuclides to the radiation processing of comet cores seems to be modest. Therefore, comets could be carriers of intact homochiral biomolecules.Part of this work was carried out during a leave at the Laboratory of Chemical Evolution.     

Serum protein polymorphisms (HP,GC, PI) in Muslims and Bodhs of Jammu and Kashmir,India

Two population groups of Jammu and Kashmir (India) — Muslims and Bodhs-have been typed for haptoglobin and for CG and PI subtype polymorphisms. The allele frequencies do not show significant differences between these two populations. HP and GC allele frequencies of Bodhs and Muslims differ considerably from with that observed in other North Indian populations. The PI allele frequencies of Bohds and Muslims differ considerably from those found in other Indian populations and are more similar to Mongoloid ones.     

Methane recovery from water hyacinth through anaerobic activated sludge process

The concepts of phase separation, anaerobic activated sludge process, and alkali pretreatment have been incorporated in this investigation with the objective of developing rational and cost-effective designs of diphasic anaerobic activated sludge systems, with and without alkali treatment, for methane recovery from water hyacinth (WH). Evaluation of process kinetics and optimization analyses of laboratory data reveal that a diphasic system with alkali treatment could be designed with an alkali pretreatment step (3.6% Na(2)CO(3) + 2.5% Ca(OH)(2) (w/w) of WH, 24 h duration) followed by an open acid phase (2.1 days HRT) and closed methane reactor with sludge recycle (5.7 days HRT, 7.7 days MCRT) for gas yield of 50 L/kg WH/d at 35-37 degrees C. Likewise, a diphasic system without alkali treatment could be designed with an open acid phase (2 days HRT) followed by closed methane reactor with sludge recycle (3.2 days HRT, 6 days MCRT) for gas yield of 32.5 L/kg WH/d at 35-37 degrees C. Detailed economic analyses bring forth greater cost-efficacy of the diphasic system without alkali treatment and reveal that the advantage accrued in terms of higher gas yield is overshadowed by the cost of chemicals in the diphasic system with alkali treatment.     

Phosphorylation of lipocortins in vitro by protein kinase C

Protein kinase C catalyzes the incorporation of about 1.1, 0.7 and 0.4 mole of phosphate per mole of Lipocortin-I (P35), Lipocortin-II (P36) and Lipocortin-85 (P36 oligomer) respectively. The phosphorylation is specific for protein kinase C and is dependent on the presence of both calcium and phospholipids. While Lipocortin-I is phosphorylated on threonine residues, Lipocortin-II and Lipocortin-85 are phosphorylated on serine residues. The substoichiometric phosphorylation of Lipocortin-85 appears to preclude the potential regulation of this protein by protein kinase C. The phosphorylation of Lipocortin-I on threonine residues and Lipocortin-II on serine residues suggests these proteins may be regulated by distinct phosphorylation-dephosphorylation reactions.     

Lipids of Cuscuta reflexa and changes in lipids of its host plants after infection

The lipid level (fresh weight basis) of Cuscuta reflexa Roxb. was related to the lipid content of the host plants Meilicago saliva L., Helianthus annuus L., Pisum sativum L. and Lantana camara L. Parasitizing by the dodder significantly increased the total lipid level of the hosts. The increase was mainly due to enhancement in the neutral lipid fraction.
The level of phospholipid in the parasite was always higher than in its hosts. Phospholidyl choline and phosphatidyl ethanolamine constituted about 65% of the total phospholipid of Cuscuta. This was followed by phosphatidyl inositol (ca 20%) and phosphatidyl glycerol (ca 12%). Phosphatidic acid constituted only ca 3% of the phospholipids of Cuscuta. Although the total phospholipid levels of various host plants were not affected as a result of the infection by Cuscuta, a significant decrease occurred in the levels of phosphatidyl eholine and phosphatidyl ethanolamine as well as marked increases in phosphatidyl inositol and phosphatidic acid. The infected tissue showed an increase in phospholipase D activity as compared with the controls. The results have been discussed in relation to changes in permeability of the infected tissue.     

Effects of fertilization and liming on the chemical soil conditions and element distribution in forest soils

Summary The distribution and storage of major elements in acid soils from a spruce and a beech forest was investigated after fertilization of NH₄NO₃ and KCl followed by Ca and Mg fertilization by 2 liming applications. All fertilizers were applied on top of the soil without mixing. Most of the added Ca and Mg was detected in the humus layer, a significant part of it still in carbonatic form. The effect of liming on mineral soil pH is very low, and was only observed in the 0–10 cm layer. However, base saturation of the mineral soil increased. The storage of C and N of the humus layer was not affected. N fertilization increased the N storage of the soil only under beech, but was followed by heavy NO₃-losses with seepage water under spruce. High leaching rates for K were also found in the spruce stand. The amount of K that was not leached increased the pool of exchangeable K in the deeper soil layer.     

Lactic acid production from whey permeate by immobilized Lactobacillus casei

Two matrices have been assessed for their ability to immobilize Lactobacillus casei cells for lactic acid fermentation in whey permeate medium. Agar at 2% concentration was found to be a better gel than polyacrylamide in its effectiveness to entrap the bacterial cells to carry out batch fermentation up to three repeat runs. Of the various physiological parameters studied, temperature and pH were observed to have no significant influence on the fermentation ability of the immobilized organism. A temperature range of 40–50°C and a pH range of 4.5–6.0 rather than specific values, were found to be optimum when fermentation was carried out under stationary conditions. In batch fermentation ～90% conversion of the substrate (lactose) was achieved in 48 h using immobilized cell gel cubes of 4 × 2 × 2 mm size, containing 400 mg dry bacterial cells per flask and 4.5% w/v (initial) whey lactose content as substrate. However, further increase in substrate levels tested (>4.5% w/v) did not improve the process efficiency. Supplementation of Mg²⁺ (1 mM) and agricultural by-products (mustard oil cake, 6%) in the whey permeate medium further improved the acid production ability of the immobilized cells under study.     

Relationship between ion requirements for respiration and membrane transport in a marine bacterium.

Intact cells of the marine bacterium Alteromonas haloplanktis 214 oxidized NADH, added to the suspending medium, by a process which was stimulated by Na+ or Li+ but not K+. Toluene-treated cells oxidized NADH at three times the rate of untreated cells by a mechanism activated by Na+ but not by Li+ or K+. In the latter reaction, K+ spared the requirement for Na+. Intact cells of A. haloplanktis oxidized ethanol by a mechanism stimulated by either Na+ or Li+. The uptake of alpha-aminoisobutyric acid by intact cells of A. haloplanktis in the presence of either NADH or ethanol as an oxidizable substrate required Na+, and neither Li+ nor K+ could replace it. The results indicate that exogenous and endogenous NADH and ethanol are oxidized by A. haloplanktis by processes distinguishable from one another by their requirements for alkali metal ions and from the ion requirements for membrane transport. Intact cells of Vibrio natriegens and Photobacterium phosphoreum oxidized NADH, added externally, by an Na+-activated process, and intact cells of Vibrio fischeri oxidized NADH, added externally, by a K+-activated process. Toluene treatment caused the cells of all three organisms to oxidize NADH at much faster rates than untreated cells by mechanisms which were activated by Na+ and spared by K+.     

Effects of physical and chemical treatments on chloroplast manganese. NMR and ESR studies

Measurements were made of the water proton relaxation rate (T^?1₂ = R₂), electron spin resonance (ESR) six-line signal of ‘free’ Mn²⁺, and O₂-evolution activity in thylakoid membranes from pea leaves. The main results are: (1) Aging of thylakoids at 35°C causes a parallel decrease in O₂-evolution activity, in R₂ and in the content of bound Mn, suggesting that R₂ may be related to the loosely bound Mn involved in O₂ evolution. (2) Treatment of thylakoids with tetraphenylboron (TPB) at [TPB] > 2 mM produces a 2-fold increase in R₂, without release of Mn²⁺. The titration curve exhibits three sharp end points. The first end point occurs at a $\text{[}\text{TPB}\text{]}\text{[}\text{chlorophyll}\text{]}$ of 1.25, at which the O₂ evolution is completely inhibited. (3) Treatment of thylakoids with NH₂OH also increases R₂ by nearly 2-fold, either by the reduction of the higher oxidation states of Mn to Mn²⁺ and / or by exposing the Mn to solvent protons. Also, progressive release of bound Mn occurs at [NH₂OH] ≥ 1 mM as shown by an increase increase in the Mn²⁺ ESR signal and a decrease in R₂. (4) Addition of H₂O₂ (0.1–1.0%) to thylakoids causes an enhancement of R₂ similar to that by NH₂OH, but without the release of Mn²⁺. (5) Heat treatment of thylakoids at 40–50°C releases Mn²⁺ and increases R₂. Conversely, pH values of 7 to 4 release Mn²⁺ without changing R₂ while pH values of 7–9 increase R₂ without releasing Mn²⁺. Thus, both high and low pH values as well as the heat treatment cause structural changes enhancing the relaxivity of the bound Mn or of other paramagnetic species.