摘要:

The colorimetric estimation of magnesium in plasma or serum by means of Titan Yellow requires an agent to stabilize the colored dye complex formed between magnesium hydroxide and Titan Yellow. Details are given of a method in which polyvinyl alcohol is used to maintain dispersion of the dye lake. A single estimation can be done on 2 cc. of serum.

ISSN:1923-4287    

DOI:10.1139/cjr48e-017

出版商:NRC Research Press    

年代:1948

数据来源: NRC

摘要:

A method for obtaining cysts ofEntamoeba histolyticafree from bacteria is described. The method involves the centrifugation and levitation of the cysts, and their passage through a series of solutions containing penicillin and streptomycin by means of a micropipette. Thousands of sterile cysts may be obtained by this method in a few hours.

ISSN:1923-4287    

DOI:10.1139/cjr48e-018

出版商:NRC Research Press    

年代:1948

数据来源: NRC

摘要:

A method for the determination of microgram amounts of thorium in tissues by the use of the thorium isotope UX1was developed.When an aqueous solution of thorium nitrate was administered orally to mice, the LD50was found to be between 1.76 and 2.0 gm. of thorium per kgm. body weight. Mice supplied with a 0.1% solution of thorium nitrate as their only source of water exhibited a greater mortality than was found in a control group. The subcutaneous injection of 50 mgm. of thorium as a thorium nitrate solution into mice produced an acute, necrotizing, inflammatory reaction at the site of injection, but no other effects. The exposure of a group of mice to an aerosol of thorium nitrate solution on each of 90 days for 40 min. each day had no effect on their mortality. The average initial concentration of thorium for each exposure to the aerosol of thorium nitrate was 330 mgm. thorium per cu. m. of air and the average final concentration was 114 mgm. of thorium per cu. m. of air.Evidence was obtained that all the thorium administered orally as thorium nitrate solution to mice is excreted by way of the feces and that no absorption from the gastrointestinal tract takes place. It is suggested that thorium nitrate owes its oral toxicity to its local action on the mucosa of the gastrointestinal tract.No evidence was obtained that thorium was transported to the viscera and very little thorium was excreted after the subcutaneous injection of 0.5 mgm. of thorium as thorium nitrate solution into mice. Most of the thorium remained at the site of injection for at least seven days. The cutaneous application of 0.3 ml. of BAL (2,3-dimercaptopropanol) appeared to cause a slight increase in the excretion of thorium, but the distribution of thorium in the mouse was not affected by this treatment.A group of mice was exposed for 180 min. to an aerosol of thorium nitrate that gave a maximum concentration of 107 mgm. of thorium per cu. m. of air and a final concentration of 3 mgm. of thorium per cu. m. of air. After this treatment the average amount of thorium found in and on one mouse was 256 μgm. Most of this was on the skin and most was excreted by way of the feces within a few days. Less than 0.2 μgm. of thorium was found in the liver, kidneys, spleen, blood, or femurs, immediately after the exposure or one day later. The average amount of thorium found in the lungs of one mouse immediately after the exposure was 3.12 μgm. and this amount decreased slowly over a period of 35 days.

ISSN:1923-4287    

DOI:10.1139/cjr48e-019

出版商:NRC Research Press    

年代:1948

数据来源: NRC

摘要:

This paper is a critical review of the "drop plate" method of determining the number of viable bacteria in fluids, together with a description of an experimental comparison of the "drop plate" with the more usual "pour plate" procedure. It is shown that counts on pure cultures of bacteria made by the "drop plate" method are some 7% higher than those made on the same cultures by the "pour plate" method. It is also shown that the standard error of a series of counts made by the "drop plate" procedure is slightly less than for those made by the "pour plate" method.

ISSN:1923-4287    

DOI:10.1139/cjr48e-020

出版商:NRC Research Press    

年代:1948

数据来源: NRC

摘要:

In the preceding paper it was shown that a "drop plate" method of determining the number of viable bacteria in pure cultures gives slightly higher counts than the usual "pour plate" method. In this paper it is shown that, in parallel counts made by the two methods on a series of samples of raw milk, the "drop plate" counts are some 27% higher than the "pour plate" counts. It is suggested that this discrepancy results from the more efficient breaking up of clumps and chains of bacteria by the dilution procedure used in preparing the "drop plates."

ISSN:1923-4287    

DOI:10.1139/cjr48e-021

出版商:NRC Research Press    

年代:1948

数据来源: NRC

摘要:

A method is described for the cultivation of bacteria on the surface of sheets of cellophane spread over layers of absorbent material as cotton saturated with any desired fluid medium. The method has proved to be useful in preparing suspensions of bacteria reasonably free from contamination by the culture medium.

ISSN:1923-4287    

DOI:10.1139/cjr48e-022

出版商:NRC Research Press    

年代:1948

数据来源: NRC

摘要:

The phosphorus-containing constituents of various tissues of the rat were separated into five fractions. These were: inorganic and organic phosphorus soluble in aqueous 10% trichloroacetic acid; phosphorus soluble in 3:1 alcohol–ether; phosphorus derived from ribonucleic acid; and phosphorus derived from thymonucleic acid. In order to test the methods, inorganic phosphate, disodium phenyl phosphate, and purified ribonucleic and thymonucleic acids were added to a homogenate of rat liver in 10% trichloroacetic acid. It was possible by separation and analysis of the fractions to obtain a quantitative recovery of the added phosphorus in the appropriate fractions. The extent to which radioactive inorganic phosphate entered the other fractions was measured following its addition to a homogenate of rat liver in 10% trichloroacetic acid. When the fractionation was performed at room temperature it was found that all of the fractions except the organic acid-soluble phosphorus fraction contained negligible amounts of the added radioactive phosphorus. The amount of radioactive phosphorus taken up by this fraction could be reduced to a negligible quantity by working quickly and with cold solutions.Data are given showing the radioactive and nonradioactive phosphorus contents of the various fractions of liver, spleen, kidney, muscle, thymus gland, lymph node, prostate gland, and testis of the rat 24 hr. after the intraperitoneal injection of a solution of radioactive inorganic phosphate. By analysis of the urine, feces, and remainder of the rat after removal of the above tissues, a quantitative account was made of the injected radioactive phosphate.

ISSN:1923-4287    

DOI:10.1139/cjr48e-023

出版商:NRC Research Press    

年代:1948

数据来源: NRC

摘要:

Analytical values are given for vitamin A, ascorbic acid, thiamine, riboflavin, niacin, calcium, phosphorus, iron, and protein on 12 diets commonly used in a modern hospital. The foods were analyzed as served to the patient. Assessed on the basis of commonly accepted standards the diets are found to be deficient in various respects, and particularly in the B-vitamins, ascorbic acid, and iron.

ISSN:1923-4287    

DOI:10.1139/cjr48e-024

出版商:NRC Research Press    

年代:1948

数据来源: NRC

摘要:

Analytical values for nine constituents of 12 diets are compared with corresponding values computed from food tables on the same diets. Factors tending to concordance or divergence in the values obtained by the two methods are discussed.

ISSN:1923-4287    

DOI:10.1139/cjr48e-025

出版商:NRC Research Press    

年代:1948

数据来源: NRC