摘要:

A method is described of using whole mounts of the mouse mammary gland with Gömöri's potassmm ferrocyanide – hydrochloric acid mixture for staining iron. Because iron accumulates in the epithelial cells in a granular form, most of the mammary gland tree of the mature nonlactating female mouse can be shown up clearly. The staining reaction is quick and uniform, muscle can be clearly differentiated in microdissection, and alveolar development can be estimated from the amount of iron retention in the nonlactating gland.

ISSN:1923-4287    

DOI:10.1139/cjr50e-001

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

Electron micrographs of purified preparations of four different insect viruses indicate the presence of morphologically different forms, which are probably stages of multiplication. The virus first appears as a minute spherical body. This body increases in size and the virus appears as an elongated, curved body, surrounded by a membrane. Later the virus particle straightens out, ruptures the membrane, and appears as a rod-shaped particle characteristic of insect viruses. One may assume that the rod-shaped virus particle contains several smaller subunits each of which develops into a rod. The complicated nature of multiplication indicates that insect viruses are organisms with a relatively simple morphological structure of the mature rod.

ISSN:1923-4287    

DOI:10.1139/cjr50e-002

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

The pyridine nucleotide content of the blood cells was measured in five normal individuals and in 27 hospital patients with various degrees of anemia. The pyridine nucleotide values of 12 anemic patients who had consumed an adequate diet for some time prior to the study were higher than those of the normal subjects. A negative correlation was observed between the cellular pyridine nucleotide content and the severity of the anemia when the latter was expressed as the logarithm of either the red cell count or the hemoglobin concentration. The remaining 15 patients had dietary histories suggestive of a low intake of niacin and protein. The blood cell pyridine nucleotide levels of this group were of the same order as those of the normal subjects but in most cases were distinctly below those of the well nourished anemic patients with a comparable degree of anemia.

ISSN:1923-4287    

DOI:10.1139/cjr50e-003

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

The stability of ascorbic acid in aqueous solution was increased under certain conditions by oxalic acid, metaphosphoric acid, glutathione, thiourea, and sodium diethyldithiocarbamate. A slight protective effect was exerted by creatinine; but formic, phthalic, and orthophosphoric acids, creatine, and caffeine had no demonstrable effect. In all these instances the pH, concentrations of reagents, etc., must be considered. In oxalate and thiourea maximum stability occurred at pH 2.5 to 3.0 and in glutathione at pH 3.6 to 4.2. The latter substance itself was also most stable at pH 3 to 4. At the optimum pH a concentration of 40 mMof oxalate gave maximal protection, this being independent of the initial concentration of ascorbic acid over the range 2 to 20 mM. Thus a stoichiometric relationship between the concentrations of the ascorbic acid and the oxalate required for protection was not found. A region of minimum solubility of oxalate in water occurred at pH 2.4 to 3.0, which coincides with the pH at which the maximum protective effect occurs and with the highest relative concentration of sodium hydrogen oxalate (or sodium hydrogen oxalate monohydrate). The absorption of ultraviolet light by ascorbic acid was altered by pH, the maximum shifting from 244 to 268 mμ from pH 2.8 to 4.5. The molecular extinction coefficient of ascorbic acid also changed with pH and was minimal at pH 4.0. This effect occurred in oxalate, which has a specific protective effect, and also in formate and orthophosphate, which have no specific protective effect. The possible mechanisms for the protection of ascorbic acid by oxalate are discussed.

ISSN:1923-4287    

DOI:10.1139/cjr50e-004

出版商:NRC Research Press    

年代:1950

数据来源: NRC