Sources and extent of pollution.
Warner F
Proceedings of the Royal Society of London. Series B, Biological sciences
Before the sources and extent of pollution can be identified a definition of pollutants has to be agreed. The degree of disruption of natural cycles in the global ecosystem in terms of residence times and assimilation capacities must be assessed as a prerequisite of any system of control. The sources of man-made and naturally occurring chemicals that fall into this definition can be categorized and these are presented for reference. Specific examples of these categories are discussed in detail, e.g. sulphur dioxide, polychlorinated biphenyls and radioactive waste. Their distribution and dilution in the environment are governed by fluid mixing mechanisms. These can be modelled to allow prediction of effects at specific points taking into account disappearance by decay, chemical reaction and deposition. Reappearance through pathways which involve accumulation and remobilization can only be predicted when a complete scientific understanding of the mechanism has been established.
10.1098/rspb.1979.0045
Infantile polyarteritis nodosa. A case report.
Schoeman C
South African medical journal = Suid-Afrikaanse tydskrif vir geneeskunde
The clinical and postmortem findings in a 4-month-old infant with polyarteritis nodosa are presented. The relationship of this condition to mucocutaneous lymph node syndrome (MLNS) is discussed, and the relevant literature is reviewed.
[Changes in the clinical picture and course of psychoses as a result of massive psychopharmacotherapy and their role in improving treatment services].
Avrutskiĭ G Ia
Zhurnal nevropatologii i psikhiatrii imeni S.S. Korsakova (Moscow, Russia : 1952)
An analysis of certain regularities in drug pathomorphosis of psychoses in the form of transitions from psychotical states to pseudoneurotic showed a slowing in their progression, changes in the syndrome structure, an increase in the amount of incomplete or reduced conditions. This circumstance prompted reconsideration of some routine therapeutic approaches. The main recommendations include restriction of neuroleptics, expansion of the diagnosis of depressions, the use of methods of intensive psychopharmacology in combination with active rehabilitation, as well as introduction of new forms of organizational aid.
Partial purification and some properties of a liver alkaline ribonuclease from the frog Rana esculenta.
Malicka-Błaszkiewicz M,Kubicz A
Acta biochimica Polonica
1. RNAases varying in pH optimum, activation with pCMB, sensitivity towards temperature and acid treatment, as well as electrophoretic mobility were found in Rana esculenta liver extract. 2. Of the three activity peaks of alkaline ribonuclease separated on CM-cellulose with 2000-fold purification, RNAase of peak C is thermo- and acid-stable and exhibits specificity for pyrimidine bases, preferring poly(U) over poly(C). 3. Differences in the specific "inhibitory effect" of frog liver supernatant on the frog liver alkaline RNAase were observed.
Fluoride inhibition of protein and DNA synthesis in cells in vitro.
Holland R I
Acta pharmacologica et toxicologica
Fluoride concentrations at and above 0.9 mM caused a progressive, concentration-related inhibition in the incorporation of both 14C-leucine and 3H-thymidine in LS cells incubated in medium with serum. The incorporation of leucine was more affected than that of thymidine. Lowering the pH enhanced the effect of fluoride on both. Removing serum from the incubation medium changed the effect of fluoride, particularly at low pH (7.0). Incorporation of leucine was then stimulated by low fluoride concentrations (0.5 and 0.9 mM), and the effect on thymidine incorporation was eradicated up to 1.3 mM-NaF. No differences were found in the pool and the specific activity of 14C-leucine in the fluoride exposed cells compared to control cells without fluoride (incubated at pH 7.4 in medium without serum). The cellular pool of 3H-thymidine decreased markedly during the incubation period, somewhat less in the fluoride exposed cells than in the control.
[Effect of vitamin D and vitamin E on the erythrocyte membrane. I. Effect on in vitro osmolar resistance and lysis].
Callari D,Cicero R,Sichel G,Abate G,Billitteri A
Acta vitaminologica et enzymologica
As in the case of retinol, low doses of cholecalcipherol and alpha-tocopherol "in vitro" increase the osmotic resistance of red blood cells, while high doses have a lytic effect on the erythrocytes of various animal species (e.g.: man, sheep, rabbit, guinea-pig, mouse, rat) with the exception of the chicken. The haemolytic effect of cholecalcipherol is less intense than that of retinol; alpha-tochopherol, while causing even less haemolysis than cholecalcipherol, involves a remarkable loss of K+ from the red cells. Besides these quantitative differences, the mechanism of action of the three vitamins seems somewhat different, as shown by modifications of the suspension medium (e.g.: pH, temperature, presence of proteins and reducing substances) or by treatment of the red cells with trypsin. Our results therefore essentially confirm the hypothesis of Dingle and Lucy of common mechanism of action of liposoluble vitamins on biological membranes.
The mechanism of transmembrane delta muH+ generation in mitochondria by cytochrome c oxidase.
Lorusso M,Capuano F,Boffoli D,Stefanelli R,Papa S
The Biochemical journal
In rat liver mitochondria treated with rotenone, N-ethylmaleimide or oligomycin the expected alkalinization caused by proton consumption for aerobic oxidation of ferrocyanide was delayed with respect to ferrocyanide oxidation, unless carbonyl cyanide p-trifluoromethoxyphenylhydrazone was present. 2. When valinomycin or valinomycin plus antimycin were also present, ferricyanide, produced by oxidation of ferrocyanide, was re-reduced by hydrogenated endogenous reductants. Under these circumstances the expected net proton consumption caused by ferrocyanide oxidation was preceded by transient acidification. It is shown that re-reduction of formed ferricyanide and proton release derive from rotenone- and antimycin-resistant oxidation of endogenous reductants through the proton-translocating segments of the respiratory chain on the substrate side of cytochrome c. The number of protons released per electron flowing to ferricyanide varied, depending on the experimental conditions, from 3.6 to 1.5. 3. The antimycin-insensitive re-reduction of ferricyanide and proton release from mitochondria were strongly depressed by 2-n-heptyl-4-hydroxyquinoline N-oxide. This shows that the ferricyanide formed accepts electrons passing through the protonmotive segments of the respiratory chain at the level of cytochrome c and/or redox components of the cytochrome b-c1 complex situated on the oxygen side of the antimycin-inhibition site. Dibromothymoquinone depressed and duroquinol enhanced, in the presence of antimycin, the proton-release process induced by ferrocyanide respiration. Both quinones enhanced the rate of scalar proton production associated with ferrocyanide respiration, but lowered the number of protons released per electron flowing to the ferricyanide formed. 4. Net proton consumption caused by aerobic oxidation of exogenous ferrocytochrome c by antimycin-supplemented bovine heart mitochondria was preceded by scalar proton release, which was included in the stoicheiometry of 1 proton consumed per mol of ferrocytochrome c oxidized. This scalar proton production was associated with transition of cytochrome c from the reduced to the oxidized form and not to electron flow along cytochrome c oxidase. 5. It is concluded that cytochrome c oxidase only mediates vectorial electron flow from cytochrome c at the outer side to protons that enter the oxidase from the matrix side of the membrane. In addition to this consumption of protons the oxidase does not mediate vectorial proton translocation.
10.1042/bj1820133
Limited-turnover studies on proton translocation in reconstituted cytochrome c oxidase-containing vesicles.
Casey R P,Chappell J B,Azzi A
The Biochemical journal
We have investigated ferrocytochrome c-induced proton ejection from reconstituted cytochrome c oxidase-containing vesicles using careful control of the number of enzyme turnovers. Ferrocytochrome c caused the appearance of protons at the vesicle exterior, and this could be abolished by using a protonophore. In addition, its decay was dependent on the permeability of the vesicle membranes to protons and the number of turnovers of the oxidase. These observations indicate that the ejection of protons was the result of genuine translocation. The possibility of this translocation occurring via a Mitchellian loop as a result of the presence of a reduced hydrogen carrier contaminating the enzyme was considered and excluded. Proton-translocating activity in this reconstituted system depended critically on the ratio of enzyme to lipid used in the reconstitution process and we propose a rationale to account for this. We conclude that our data provide strong support for the proposal that cytochrome c oxidase acts as a proton pump and that approx. 0.9 H+ is excluded per ferrocytochrome c molecule oxidized.
10.1042/bj1820149