摘要:

Rabbit polymorphonuclear leucocytes contain an enzyme capable of hydrolyzing biosynthetic phenolphthalein mono-β-glucuronide. The concentration of the enzyme in the white cell is some 2000 times the concentration of the enzyme in the blood plasma. Under the conditions of study, the β-glucuronidase activity was proportional to the concentration of the enzyme. The effect of substrate concentration on the enzyme activity was studied and the Michaelis constant,Ks, determined. The course of the reaction was linear with time for the first 12 hr. and then fell off slightly during the next 12 hr. The optimum pH of the enzyme was 4.45 in either 0.2 Macetate or 0.2 Mphthalate buffer. It was not inhibited by cyanide, azide, iodoacetate, fluoride, glycine, thiourea, urethane, arsanilic acid, acetophenone,o-cresol orm-cresol, in a final concentration of 0.01 M. The possible function of β-glucuronidase in rabbit polymorphonuclear leucocytes is discussed.

ISSN:1923-4287    

DOI:10.1139/cjr50e-012

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

The oleic acid – albumin agar, proposed by Dubos and Middlebrook as a diagnostic medium for the isolation ofMycobacterium tuberculosis, proved useful for determining streptomycin resistance. By growing cultures ofM.tuberculosison this translucent substrate, containing graded amounts of streptomycin, a close correlation was found between the observed streptomycin resistance and that determined in fluid tween-albumin medium. The initial presence of a few organisms, showing a slight resistance to streptomycin, was found not to be an exclusive characteristic of cultures developing drug resistance in the course of streptomycin therapy. Cultures not developing resistance may also contain such resistant cells.

ISSN:1923-4287    

DOI:10.1139/cjr50e-013

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

Following the general procedure of Risley, Raymond, and Barnes the effects of urinary extracts on gastric secretion have been studied in the Shay operated young, male, albino rat. The procedure consisted of ligating the pylorus following a 24 hr. fast. Immediately postoperatively the test material was administered. After a five hour period the stomach was removed, opened, and rinsed into 10 ml. of distilled water. An aliquot of this was titrated for its free and total acid content. Human chorionic gonadotrophin and preparations obtained by the benzoic acid absorption method from human and equine pregnancy urine were studied for their effects on gastric section using the above technique after subcutaneous, intraduodenal, and oral administration. It was found that chorionic gonadotrophin caused gastric secretory depression at a dose level as low as 10 mgm. per rat subcutaneously. Both the human and equine preparations were observed to reduce the gastric secretion proportionately to the dose when administered subcutaneously. When administered by intraduodenal injection at the time of operation, the equine preparation was active but required several times the subcutaneous dose to produce comparable results. Oral administration of both equine and human pregnancy urine extracts showed antisecretory activity only in the former at the dose levels employed. In addition, the effects of possible complicating factors such as estrogens, pyrogens, and nonspecific damage on gastric secretion have been investigated and found to play no appreciable part in the results produced by the urine fractions.

ISSN:1923-4287    

DOI:10.1139/cjr50e-014

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

Confirming previous reports, a cytological study of the spinous process and sternal marrow showed a marked similarity in two groups of normal subjects. In each of 12 patients with various hematopoietic disorders samples were taken from the sternum and the spinous process. The marrows from the two sites were nearly identical. These findings suggest that the present knowledge of changes occurring in sternal marrow in disease may be applied to spinous process marrow.

ISSN:1923-4287    

DOI:10.1139/cjr50e-015

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

The pyridine nucleotide content of the blood cells (PN/BG) of four normal individuals and five anemic patients was measured repeatedly before and after supplementing the diet with niacin. Daily doses of 50 mgm. nicotinic acid or nicotinamide failed to affect the values in the normal subjects and two well-nourished anemic patients. The same dose of nicotinic acid rapidly raised the PN/BC of three poorly nourished anemic patients to values approximating those of well-nourished subjects with similar degrees of anemia. The results obtained after saturation with niacin confirmed the previous report that the PN/BC is higher in anemic patients than in normal controls and that a negative correlation exists between the pyridine nucleotide values and the severity of the anemia. In spite of continued niacin therapy, correction of the anemia was accompanied by a gradual decrease in the values until they approached those of the normal subjects. The present findings also confirm the earlier report that changes in the PN/BC are apparently independent of moderate variations in the number of circulating leucocytes and reticulocytes and bear no relationship to the size or hemoglobin content of the red cells. The significance of these findings in relation to human niacin nutrition is discussed.

ISSN:1923-4287    

DOI:10.1139/cjr50e-016

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

A titrimetric micromethod is described for estimating the lipolytic action of rat serum on tributyrin, tripropionin, and ethyl butyrate. A study has been made of factors affecting the action of the enzyme. Values for serum lipase levels of normal adult male and female rats are presented for the three substrates.

ISSN:1923-4287    

DOI:10.1139/cjr50e-017

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

The pH, oxidation–reduction potential, total solids, nonspecific hemagglutination titer, and the titer of the inhibitor of influenza virus hemagglutination have been determined in the normal allantoic fluid of the chick embryo as the incubation time increased. These determinations were repeated after the allantoic fluid had been stored for 48 hr. at 0 °C. It was found that as the incubation time increased (1) the pH decreased progressively, (2) the Eh remained positive throughout, (3) the total solid content increased, (4) the nonspecific hemagglutination titer remained negligible, (5) the inhibition titer increased rapidly. Storage for 48 hr. at 0 °C. produced no change other than a small rise in the pH. By buffering the allantoic fluidin vivo, it appeared that the increasing inhibition titer was not directly related to the decreasing pH. The inhibition titer of the allantoic fluid was not decreased after dialysis, indicating that it is not affected by the amount of urates in the fluid. Thus it appears that the inhibition titer is related directly to a component of the increasing total solids which is unidentified as yet.

ISSN:1923-4287    

DOI:10.1139/cjr50e-018

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

Radioactive inorganic phosphorus placed in the allantoic sacs of embryonated eggs three hours after inoculation with influenza virus was incorporated into the structure of the virus during its growth. There was little or no direct exchange between the virus and radioactive inorganic phosphorus. The specific activity of purified labelled virus rose linearly with increasing amounts of radioactive phosphorus administered to the eggs. When radioactive phosphorus was placed in the allantoic sac 48 hr. before inoculation with influenza virus the newly formed labelled virus had a specific activity about 20% higher than when isotope was administered at the same time as virus. As the amount of isotope injected into each infected egg was increased up to 775 μrd. an increasing number of embryos died during the subsequent period of virus growth. The yield of virus from the surviving eggs was not less than from eggs which had not received radioactive phosphorus. Under the experimental conditions described the amount of isotope which could be introduced into influenza virus was not sufficient to permit the use of the marked virus in metabolism experiments in animals or embryonated eggs.

ISSN:1923-4287    

DOI:10.1139/cjr50e-019

出版商:NRC Research Press    

年代:1950

数据来源: NRC