摘要:

Of various strains of fungi isolated from soil that showed antibiotic activity against Gram-positive and Gram-negative bacteria, two species ofPenicillium, producing culture filtrates of high antibacterial titre, were studied in more detail. The active substance, when crystallized, was considered to be claviformin (clavacin, clavatin, patulin). Studies on the production of the antibiotic, its assay, and its extraction from culture filtrates are described.

ISSN:1923-4287    

DOI:10.1139/cjr46e-001

出版商:NRC Research Press    

年代:1946

数据来源: NRC

摘要:

Experiments have been conducted on the production and treatment of motion sickness on human volunteers. Of 369 men tested after treatment by a placebo, 56.6% vomited. Tests were repeated at weekly intervals on 183 susceptible individuals so that 661 tests were performed. Repeat tests on 24 subjects not susceptible after treatment with a placebo showed that 12% were ill when no treatment was given. Ten susceptible subjects were swung through only one-half the usual degree of swinging. Of these eight vomited. This procedure selected persons of marked susceptibility to motion sickness.The consistency of the time of vomiting was determined by 106 tests on 65 susceptible men. In repeated tests after a placebo only eight were 13 min. more than the control test. For assaying drugs a standard procedure was adopted. Susceptible individuals were classed as those who, after taking a placebo, vomited before 30 min. of swinging. A susceptible individual was considered protected if in a test a week later he did not vomit and remained swinging for 13 min. longer than his control time. Improvement was present if a person vomited but the time was 13 min. longer than the control. In no case was swinging less than 30 min.The effect of a number of barbiturates on swing sickness has been determined. The most effective wasV-12, ethyl-β-methylallylthiobarbituric acid, when administered in a divided dose of a total of five grains. In this case 78% were protected or improved. With a single dose of three grains 26% were similarly affected.V-17 (allylisoamylbarbituric acid)—two grains,V-16 (dicrotylbarbituric acid)—three grains,V-15 (allyl-sec-butylbarbituric acid)—one grain,V-14 (ethylcrotylthiobarbituric acid)—two grains,V-9 (n-butyl-1-methylallylthiobarbituric acid)—nine grains, and sodium amytal—one grain, showed less or no effect. Hyoscine hydrobromide in single doses of 0.4 and 0.65 mgm. showed 31 and 50% protected or improved respectively. The R.C.N. remedy gave a figure of 58%. After removal of nicotinic acid from the R.C.N. mixture 60% were benefited. Nicotinic acid alone, or pretreatment with thiamin gave no protection.A combination of three grains ofV-12 with hyoscine was more effective than when either drug was used alone. With a dose of five grains ofV-12 and hyoscine the results were only slightly better (80%) when compared with the same dose ofV-12 alone (78%). It is suggested that the most effective form of administration ofV-12 may be by divided doses of two and one-half grains twice daily for at least 24 hr. previous to exposure to motion.

ISSN:1923-4287    

DOI:10.1139/cjr46e-002

出版商:NRC Research Press    

年代:1946

数据来源: NRC

摘要:

Certain intestinal bacteria can synthesize some of the B vitamins, and others may synthesize vitamin K. In an attempt to deprive rats, maintained on a riboflavin deficient ration, of riboflavin that might have been synthesized in the intestine, sulphanilylguanidine (sulphaguanidine) was fed with the diet at a level of 0.75% for 78 days. Four groups of animals were used. The control group was maintained on the basal ration; Group 2 on the basal ration plus 0.75% sulphaguanidine; Group 3 on the riboflavin deficient ration; and Group 4 on the riboflavin deficient ration plus 0.75% sulphaguanidine. Growth curves, clotting times, red cell counts, and sulphonamide concentrations in blood, urine, and faeces were determined and chemical analyses of urinary calculi were performed. In addition, microscopic examinations of liver, spleen, kidney, and cornea were made in each animal. Sulphaguanidine added to the basal ration had a negligible effect on growth, but when added to the riboflavin deficient ration a cessation of growth occurred accompanied by anaemia and hypoprothrombinaemia. The symptoms of vitamin K deficiency disappeared upon administration of 2-methyl-1,4-naphthoquinone. Renal damage was observed in every rat that had received sulphaguanidine and was especially severe in the animals comprising Group 4. Urinary calculi were found only in those animals that had received sulphaguanidine and the incidence was highest in Group 4. The data indicate that the symptoms of riboflavin deficiency can be aggravated by sulphaguanidine and conversely that the toxic effects of sulphaguanidine may be aggravated by riboflavin deficiency.

ISSN:1923-4287    

DOI:10.1139/cjr46e-003

出版商:NRC Research Press    

年代:1946

数据来源: NRC

摘要:

A procedure is described for comparing the effectiveness of different infusion media in the prevention of fatal shock. Using this procedure it was found that each of the solutions increased the chances for survival if given in adequate amounts early in shock. While 97% of the animals died without treatment, only 8% died after receiving a transfusion of plasma. Saline gave about one-third as many survivals as plasma, and the solutions of isinglass and polyvinyl alcohol were intermediate in their effectiveness.

ISSN:1923-4287    

DOI:10.1139/cjr46e-004

出版商:NRC Research Press    

年代:1946

数据来源: NRC