摘要:

When rats are starved by withholding all food, though giving water, they develop, two or threes days before death a typical behaviour syndrome, in winch at first there is increased activity, and subsequently, in old animals, marked immobility. At this pre-mortal stage in old animals, or the corresponding stage in younger rats, they have lost 30% or more of their body weight, and if they killed the adrenals are found to be enlarged and discoloured to a dark grey or dark dirty grey. These enlarged glands contain an increased amount of water though their solid content remains practically unaltered, the change representing an increase in the water content of the cells (possibly confined to the cortex). The glomerular zone is diminished in thickness, and the reticular zone also shows abnormality. Animals killed before they have lost 30% of their body weight still have normal adrenals (normal in size, weight, water content, and colour).The enlargement produced m the pre-mortal stage of inanition is a pathological process and is not a hypertrophy. Data in the literature suggest that certain types of adrenal enlargement such as that produced by deficiency of the B-complex vitamins may be similar in nature. The kidneys, heart, and gonads of acutely starved rats tend to lose weight more slowly than the whole body; the liver and spleen more rapidly; and the thyroid at about the same rate.

ISSN:1923-4287    

DOI:10.1139/cjr46e-005

出版商:NRC Research Press    

年代:1946

数据来源: NRC

摘要:

A study has been made on the effect of X-ray irradiation by producing inactivation ofp-aminobenzoic acid as determined by assay withC.acetobutylicum. It has been shown thatp-aminobenzoic acid in concentration of 1 × 10−4 μgm. per cc. is inactivated by an X-ray dose as small as 50rat 190 kv. The significance of the destruction of Paba in connection with the treatment of infective lesions is discussed.

ISSN:1923-4287    

DOI:10.1139/cjr46e-006

出版商:NRC Research Press    

年代:1946

数据来源: NRC

摘要:

Mosquitoes used for virus analysis in Manitoba are obtained by means of hand catches or by the use of light traps, sometimes supplemented with dry ice. A trap is described that has been used successfully for this purpose during the past three years. This trap is simple to operate, the insects are taken in good condition for identification, and newly emerged specimens are killed, thereby eliminating the majority of those that could not possibly be infected with the virus of western equine encephalitis. The methods of shipping, sorting, identifying, and storing specimens are given. These methods are, in large part, standard entomological procedures adapted to present needs.

ISSN:1923-4287    

DOI:10.1139/cjr46e-007

出版商:NRC Research Press    

年代:1946

数据来源: NRC

摘要:

Since an epidemic of western equine encephalitis in Manitoba in 1941, attempts have been made each year to isolate the virus from mosquitoes collected during the summer months. In 1942, 94 pools of mosquitoes were tested: 43 of the genusAedes, 36 ofCulex, and 15 ofCuliseta. Suspensions made from each pool, which consisted of from 1 to 30 insects, were injected intracerebrally into guinea pigs. No isolation of virus was made. In 1943, 69 pools were tested: 49 ofAedes, 6 ofCulex, 1 ofCuliseta, 1 ofAnopheles, and 12 of mixtures of different genera. Each suspension was derived from 10 to 75 mosquitoes and was injected intracerebrally into Rockefeller strain Swiss mice. There was no recovery of virus. In 1944, 90 pools were tested: 10 ofCulex, 74 ofAedes, and 6 ofCuliseta. Suspensions were usually made from 70 to 100 insects, and injected intracerebrally into Swiss mice of the Rockefeller strain. From one pool ofCulex restuans(Theo.), a strain of western equine encephalitis virus was recovered.

ISSN:1923-4287    

DOI:10.1139/cjr46e-008

出版商:NRC Research Press    

年代:1946

数据来源: NRC

摘要:

Precipitin tests are used to determine the source of the blood meal of Saskatchewan mosquitoes. The tests disclose that theAedesmosquitoes of the prairie feed extensively on man, horse, cow, and bird. The degree to which the species feed upon a particular host appears to be determined largely by the availability of that host. The number of individual specimens reacting to more than one antiserum is high, on the average one out of three belonging in this group. In spite of the multiple feeding habits of theAedesspecies and their relatively great abundance, they do not appear to play a major role in the transmission of western equine encephalomyelitis.

ISSN:1923-4287    

DOI:10.1139/cjr46e-009

出版商:NRC Research Press    

年代:1946

数据来源: NRC

摘要:

It has previously been reported by Jaques that fibrinogen and fibrin possess marked reducing powers. In a further investigation of this property, the reduction of hydrogen peroxide by these proteins has been studied. Commercial fibrin sometimes contains large amounts of catalase. Methionine in phosphate buffer reduces hydrogen peroxide at pH 6.6 and temperature of 25 °C. This reduction is increased by copper and molybdate. The reduction of hydrogen peroxide by fibrinogen and fibrin free of catalase is due to the methionine residue.

ISSN:1923-4287    

DOI:10.1139/cjr46e-010

出版商:NRC Research Press    

年代:1946

数据来源: NRC

摘要:

The complement-fixing antibodies present in epidemic and murine typhus immune sera can be differentiated by quantitative absorption tests. The neutralizing antibodies that participate in the Giroud reaction can be differentiated by quantitative inhibition tests.Epidemic and murine typhus immune sera contain two kinds of complement-fixing antibodies and also two kinds of neutralizing antibodies. The antigens that react with these antibodies differ in specificity and thermal resistance. Cross reactions between epidemic and murine rickettsiae are due to the presence of similar heat stable antigens in the two types. Type specific sera may be obtained by absorbing immune serum with either (a) rickettsiae of heterologous type or (b) heated rickettsiae of homologous type. The specific antibodies react only with the heat labile antigens of the homologous type of rickettsiae.Mice may be actively immunized against the toxic factors of murine and epidemic rickettsiae. The immunity produced by small doses of vaccine is type specific and dependent on the presence of heat labile antigen in the vaccine.

ISSN:1923-4287    

DOI:10.1139/cjr46e-011

出版商:NRC Research Press    

年代:1946

数据来源: NRC