摘要:

SUMMARYThe sulphydryl and disulphide contents of rat lungs were measured before and after exposure of rats to oxygen at 5 atmospheres absolute (OHP). After 45 minutes at this pressure lung damage occurred, and a decrease in ‐SH groups together with an increase in ‐SS‐ groups was found, such that the ‐SH/‐SS‐ ratio in the lung tissue was halved. Injections of pentobarbital sodium, which protect against OHP lung damage, reduce auto‐oxidation of ‐SH content of lung homogenate exposed to air in euro and also reduce ‐SH oxidation in lungs of OHP exposed rats.

ISSN:0004-945X    

DOI:10.1038/icb.1963.38

出版商:Nature Publishing Group    

年代:1963

数据来源: WILEY

摘要:

SUMMARYThe normal range for the urinary excretion of histidine metabolites after an oral loading dose of 15 grams of histidine monohydrochloride was 0–22.3 mg./5 hour urine. The excretion rates of the individual metabolites were formiminoglutamic acid 0–16.6 mg./5 hour urine and urocanic acid 0–9.6 mg./5 hour urine. No significant difference was found between the levels in males and females.The urines of 31 patients were examined for histidine metabolites after oral loading with 15 grams of histidine monohydrochloride. Twenty‐one patients excreted abnormal quantities of Figlu, and eight also excreted an excess of urocanic acid. Urocanic acid may make a significant contribution to the total histidine metabolites excreted.

ISSN:0004-945X    

DOI:10.1038/icb.1963.39

出版商:Nature Publishing Group    

年代:1963

数据来源: WILEY

摘要:

SUMMARYIntracerebral injection of the alkylating agent N‐ethyl maleimide facilitated the entry of albumin‐bound bilirubin into the cerebrospinal fluid of adult rabbits.Animals in which very high CSF‐bilirubin levels (>10 μg./ml.) had been induced showed cerebral icterus. In other animals, no correlation was observed between the CSF‐bilirubin concentration (in the range 1–4 μg./ml.) and the degree of cerebral icterus.The rabbit brain made hypersensitive by experimental allergic encephalomyelitis showed no abnormal entry of bilirubin.The type and degree of change is different from that observed in kernicterus. However, present observations are presented to demonstrate the kind of factor which can affect the normal blood‐CSF barrier.

ISSN:0004-945X    

DOI:10.1038/icb.1963.40

出版商:Nature Publishing Group    

年代:1963

数据来源: WILEY

摘要:

SUMMARYA beta‐adrenergic blocking agent, Alderlin (2‐isopropyl‐amino‐1‐(2 naphthyl) ethanol hydrochloride), was given intravenously to intact anaesthetised dogs. The following changes were noted: increase in heart rate and cardiac output; decrease in systemic and pulmonary arterial blood pressure and resistances. Coronary blood flow decreased, with an increase in cardiac oxygen consumption. Cardiac efficiency was maintained.

ISSN:0004-945X    

DOI:10.1038/icb.1963.41

出版商:Nature Publishing Group    

年代:1963

数据来源: WILEY

摘要:

SUMMARYSome metal chelates of substituted 1, 10‐phenanthrolines inactivate the infectivity of certain viruses. Other viral properties, including haemagglutination, antigenicity and the capacity to adsorb to host cells, are also affected, though to a lesser extent.The interaction between virus and chelate is partly reversible, since the haemagglutinating capacity of treated virus can be restored by washing.The relation between chemical structure and activity of various chelates as well as the sensitivity of viruses of differing chemical constitution, indicates that the chelates act purely physically following adsorption to the viral surface.

ISSN:0004-945X    

DOI:10.1038/icb.1963.42

出版商:Nature Publishing Group    

年代:1963

数据来源: WILEY

摘要:

SUMMARYAn assay system has been developed for the rapid and accurate titration of the virus‐inhibitory activity of antiviral agents.Metal chelates of substituted 1,10‐phenanthrolines, at concentrations well below those lethal to virus, inhibit the growth of influenza virus in chick embryo allantois‐on‐shellin vitroby acting on the host cell.Amongst a Large group of metal chelates there are significant relationships between chemical structure and virus‐inhibitory activity.The most active compound, [Ru(3,5,6,8‐tetramethylphen)2acetylacetone]+, at a con centration as low as 10−6M, completely and irreversibly inhibits the growth of up to 10,000 ID50of virus within 20 minutes of contact with cells. It has no effect on adsorption or penetration of virus into the cell, but acts during the eclipse period to prevent the synthesis of new virus.All concentrations of [Ru(3,5,6,8‐tetramethylphen2acetylacetone]+inhibiting viral repro duction also depress the utilization of oxygen by the cells.

ISSN:0004-945X    

DOI:10.1038/icb.1963.43

出版商:Nature Publishing Group    

年代:1963

数据来源: WILEY

摘要:

SUMMARYA technique has been evolved whereby the rate of attachment or adherence of bacteria to mouse peritoneal macrophages can be studied.The aim of the technique was to obtain samples, taken at intervals after mixing a suspension of bacteria and macrophages, which contained bacteria not yet associated with cells. This was achieved by passing the test suspensions through filters holding back macrophages but allowing tin‐ free passage of bacteria not attached to these cells.Using this method no association ofS. typhimuriumC5 with macrophages occurs unless the organisms have been opsonised. It has also been shown that there are one or more heat‐labile antigens present on the surface of this organism. These must be covered before the organism will adhere to the surface of mouse macrophages.

ISSN:0004-945X    

DOI:10.1038/icb.1963.44

出版商:Nature Publishing Group    

年代:1963

数据来源: WILEY

摘要:

SUMMARYThe distribution and activity of adenosine‐triphosphatase in homogenates and subtractions of guinea pig kidney cortex has been examined. A portion of the activity associated with particulate fractions could be further stimulated, in the presence of magnesium ions, by the combined addition of sodium and potassium ions but not by the addition of either cation alone or in combination with choline.Treatment of the heavy microsome subfraction with deoxycholate resulted in a large increase in the specific activity of this enzyme, which now required sodium and potassium ions in a ratio of 4 : 1 for over 85 p.c. of its total activity. Under such conditions of cation stimulation, optimum pH was found to be between 7.5 and 8.0, and the enzyme also exhibited considerable temperature dependence and was stable up to 55°C.The cardiac glycoside Ouabain completely inhibited that portion of enzyme activity stimulated by monovalent cations but was without effect on the activity observed in the presence of magnesium ions alone.The effect of other reagents and hormones on the cation stimulated adenosine‐triphosphatase activity was also examined, with a discussion of the possible significance of this enzyme in active cation transport.

ISSN:0004-945X    

DOI:10.1038/icb.1963.45

出版商:Nature Publishing Group    

年代:1963

数据来源: WILEY

摘要:

SUMMARYThe coagulation activity of an ether extract of the acetone‐insoluble material from yolks of eggs of domestic fowl was very low in comparison with a similar extract prepared from mammalian brain.The ether‐soluble material was Chromatography on silica gel using chloroform‐methanol for elution with stepwise increases in the methanol concentration.Fractions eluted with chloroform‐methanol, 90:10 (v/v), contained phosphatidic acids and showed considerable coagulation activity.Phosphatidylethanolamines were only slightly active.Phosphatidylcholines were inactive.Heating of ether‐soluble egg yolk phospholipids in air increased coagulation activity and resulted in a decrease in the amino N:P ratio but no significant alteration in unsaturation.Pure phosphatidylethanolamine heated in air did not show an increase in coagulation activity.Admixture of phosphatidylcholines with phosphatidylethanolamines did not result in any increase in activity.Enzymatically prepared phosphatidates were less active than the active fraction of egg yolk phospholipids.

ISSN:0004-945X    

DOI:10.1038/icb.1963.46

出版商:Nature Publishing Group    

年代:1963

数据来源: WILEY