摘要:

Studies have been made of the growth ofV.choleraein fluid media of chemically defined compositions. The addition of three amino acids, tyrosine, asparagine, and glycine, to a fluid medium containing inorganic salts produced a growth ofV.choleraeequivalent to a 450 p.p.m. silica standard. Under conditions of aeration with an air and carbon dioxide mixture, yields comparable to the turbidity of a 1600 p.p.m. silica standard were obtained with a medium composed of 0.67 gm. of tyrosine, 0.42 gm. of asparagine, 0.51 gm. of glycine, 5.0 gm. of sodium chloride, 5.0 gm. of ammonium sulphate, 0.75 gm. of dipotassium hydrogen phosphate, 0.1 gm. of magnesium sulphate, 10.0 gm. of glucose, and 15.0 gm. of sodium bicarbonate dissolved in one liter of distilled water.

ISSN:1923-4287    

DOI:10.1139/cjr50e-035

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

Groups of guinea pigs on a basic diet of commercial rabbit pellets supplemented by fresh green grass or stored roots exhibited marked differences in the ascorbic acid level of their plasma. These differences were not accompanied by any significant variation either in the complement titer of the serum or the prothrombin time of the plasma. Such minor variations as were observed in these two activities did not parallel each other.

ISSN:1923-4287    

DOI:10.1139/cjr50e-036

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

A procedure is described which permitted the phosphorus containing constituents in allantoic membranes of embryonated eggs to be separated into fractions as follows: alcohol soluble phosphorus from which the phospholipids were separated, phosphorus soluble in 5% trichloroacetic acid in which inorganic phosphorus was determined, and nucleic acid phosphorus which was further separated into pentose and desoxypentose nucleic acids. This procedure was applied to membranes between 9 and 13 days of age. It was found that the total phosphorus amounted to 9 to 10 mgm. per gm. of dried tissue. Alcohol soluble phosphorus accounted for approximately 28%, acid soluble phosphorus for 37%, and nucleic acid phosphorus for 35% of the total phosphorus. About half the acid soluble phosphorus was inorganic and about 85% of the alcohol soluble phosphorus was associated with phospholipids. These proportions remained essentially constant over the period studied. The ratio of pentose to desoxypentose nucleic acid phosphorus also remained fairly constant over the interval at about 2.2. There was no significant difference in the amounts of P32taken up over a period of 72 hr. by normal allantoic membranes and those infected with influenza virus, when inorganic radioactive phosphorus was placed in the allantoic sacs of 11-day embryonated eggs.

ISSN:1923-4287    

DOI:10.1139/cjr50e-037

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

T2r+bacteriophage grown in its host,Escherichia coliB, in broth medium in the presence of radioactive inorganic phosphorus was labelled with the isotope. Purified suspensions of this virus had specific activities up to 50,000 c.p.m. per μgm. P. There was little or no exchange of P32between virus and inorganic phosphate. Chemical analysis showed that at least 98% of the virus phosphorus was contained in nucleic acid; of the nucleic acid phosphorus 95.5% was associated with desoxypentose nucleic acid and 4.5% with pentose nucleic acid. More than 99% of the radioactivity of the labelled bacteriophage was contained in the nucleic acid fraction. Preparations of bacteriophage were obtained with sufficiently high specific activity to enable metabolism experiments to be carried out on the growth of the labelled virus in the host cell.

ISSN:1923-4287    

DOI:10.1139/cjr50e-038

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

The antihaemolytic values (AHV) of the erythrocytes and plasma of experimental rabbits have been determined by the lysolecithin method. Oral administration of cholesterol resulted in hypercholesterolaemia; and the increase in plasma AHV paralleled the rise in free cholesterol in approximately a 1:1 molar ratio of lysolecithin to cholesterol. No changes in the erythrocytes were observed, other than a mild anaemia. Splenectomy followed by cholesterol feeding afforded essentially the same results. In the normal rabbit it is concluded that the free cholesterol contributes very little to the antihaemolytic value of the plasma. Repeated bleeding caused a hypercholesterolaemia, and an elevation of the plasma AHV which paralleled the free cholesterol. In the haemolytic anaemia caused by acetylphenylhydrazine injections, the chief findings were an increase in hypotonic fragility of the erythrocytes, and a decrease in the plasma AHV. In all the experiments the mean erythrocyte AHV varied with the size of the cells, but appeared to be otherwise unaffected by the experimental procedures.

ISSN:1923-4287    

DOI:10.1139/cjr50e-039

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

The inoculation of guinea pigs with pneumococci Type I intraperitoneally resulted in the development of homologous agglutinating antibodies, which were detected in the sera as early as five hours after inoculation. The early appearance of active immunity, and the attainment of a sufficient titer, would appear to govern survival to a fatal homologous re-infecting dose of the organism.

ISSN:1923-4287    

DOI:10.1139/cjr50e-040

出版商:NRC Research Press    

年代:1950

数据来源: NRC