bluuebunny/crossref_metadata_2025_split huggingface dataset:
NON-FATAL INFECTION OF MICE FOLLOWING INTRACEREBRAL INOCULATION OF YELLOW FEVER VIRUS
Authors: Fox John P. 
Published: June 2004

Observations have been reported which indicate that mice inoculated intracerebrally with active yellow fever virus may develop an infection which is not only non-fatal but may also be completely inapparent.
The most extensive observations were made on mice which showed signs of infection but were still alive 22 days after inoculation with virus of one or another of several 17D substrains. In such cases, the infection usually progressed no further and partial or complete recovery often ensued. Agents other than yellow fever virus were excluded as a significant cause of such nonfatal infections by the failure of repeated attempts to isolate other infective agents, by the demonstration of antibodies against yellow fever virus in the sera of the mice, and by the demonstration of a high degree of resistance on the part of such surviving mice to reinoculation with large doses of neurotropic yellow fever virus.
Completely inapparent infections with 17D virus were also shown to occur. Studies of apparently normal survivors of 17D virus titrations revealed a small but significant number of animals resistant to intracerebral challenge with neurotropic yellow fever virus. Further, pooled sera from such mice were shown to contain specific protective antibodies.
The occurrence of non-fatal infections with 17D virus was found related to virus dose and substrain. Small doses of virus provoked a significantly higher proportion of non-fatal infections than large doses; while different 17D substrains, tested over equivalent ranges of virus dose, varied greatly with respect to the proportion of infections which did not terminate with death. In the case of two substrains (17DD low and 17D3), non-fatal infections (as demonstrated by resistance to intracerebral challenge with neurotropic virus) were sufficiently frequent to cause an increase, when included in the computation of the infective titers, of 25 per cent above the figures based on deaths alone. The demonstration of non-fatal infections, thus, may be important to the accuracy of quantitative determinations of infectivity.
Limited observations with virus of the French neurotropic and the pantropic Asibi strains revealed that non-fatal infections do occur, but only rarely.
Somewhat more extensive observations with unmodified virus of strains isolated from Brazilian cases of jungle yellow fever, in contrast, revealed an occurrence of non-fatal infections much greater than that observed with the most productive 17D substrains. With these jungle strains, the demonstration of non-fatal infections proved indispensable to any measure of the level of infectivity of virus preparations.
The demonstration of the proportional occurrence in mice of non-fatal infections with yellow fever virus provides an additional means by which different virus strains and substrains may be characterized.
THE INFLUENCE OF AGE OF HOST AND TEMPERATURE OF INCUBATION ON INFECTION OF THE CHICK EMBRYO WITH VESICULAR STOMATITIS VIRUS
Authors: Sigurdsson Björn 
Published: June 2004

Chick embryos after 7 days of incubation were found to be much more susceptible to infection with vesicular stomatitis virus than were 10 day embryos. They had a 100 per cent mortality and were very suitable for titrations of the virus. The rate of increase of virus in 7 and 10 day embryos was studied. Two different temperatures of incubation were employed, 35–36°C. and 39–40°C., and the growth curves for the virus under the different conditions are presented. 10 day embryos were highly resistant and at 39–40°C. more than half of them survived. At the lower temperature of incubation, 35–36°C., all 10 day embryos died, but they survived much longer than did 7 day embryos.
In the 7 day embryos death occurred after about 12 hours at 39–40°C. and after about 16 hours at 35–36°C., or earlier at the higher temperature.
In embryos of both ages the virus titer reached at the higher temperature was only about 1 per cent of that reached at 35–36°C., even in those that died.
FURTHER STUDIES ON THE TITRATION AND NEUTRALIZATION OF THE WESTERN STRAIN OF EQUINE ENCEPHALOMYELITIS VIRUS IN TISSUE CULTURE
Authors: Huang C. H. 
Published: June 2004

1. Titration and neutralization of the Western strain of equine encephalomyelitis virus can be carried out in vitro by means of tissue culture.
2. The in vitro titration test as presented is a more sensitive method than animal inoculation.
3. Tissue culture may be better than animal inoculation for the detection of small amounts of virus.
4. The neutralization obtained in tissue culture is 100 to 1,000 times greater than that observed in the intracerebral test in mice and is comparable to the potency obtained by the intraperitoneal route of inoculation.
5. The possibility of applying this method to the study of other viruses, known and unknown, is discussed.
6. Further applications of the method described above to evaluation and standardization of bacterial toxins and antitoxins and to the testing of the toxicity of biological and chemical products are suggested.
7. Evidence for the reactivation in vitro as well as in vivo of virus in neutral mixtures by dilution is presented.
INCREASED RESISTANCE TO VIRAL INFECTION AS A RESULT OF INCREASED FLUID IN TISSUES
Authors: Taylor Haywood M. , Sprunt Douglas H. 
Published: June 2004

Experiments are described in which it is shown that the estrogenic hormone (α-estradiol propionate) increases the amount of extracellular fluid in the skin. Since previous work showed that this hormone increases resistance of rabbits to vaccinia virus, it is suggested that the increased resistance is the result of increased fluid in the tissues.
In further test of this thesis, experiments were performed in which the extracellular fluid in the skin was increased by the intraperitoneal injection of a salt solution known to increase the hydration of the tissues. Under these conditions it was found that the spread of India ink in the skin, as well as susceptibility to viral infection, was decreased in the same magnitude as obtains when the animals are treated with estrogenic hormone. The identity of effects under the two sets of circumstances seems to warrant the conclusion that in both instances the spread of India ink and decreased susceptibility to vaccinia are due to the common factor of increased volume of the extracellular fluid.
THE ELIMINATION OF ADMINISTERED ZINC IN PANCREATIC JUICE, DUODENAL JUICE, AND BILE OF THE DOG AS MEASURED BY ITS RADIOACTIVE ISOTOPE (Zn65)
Authors: Montgomery M. Laurence , Sheline G. E. , Chaikoff I. L. 
Published: June 2004

The excretion of intravenously injected labeled zinc into pancreatic juice, duodenal juice, and bile of the dog was investigated. The use of the radioactive isotope permitted the injection of minute amounts of zinc, amounts that were negligible when compared with the total amount of zinc already present in the animal.
1. A large proportion of the injected Zn65 was eliminated by way of the external secretion of the pancreas. As much as 11 per cent was excreted in the pancreatic juice in 14 days.
2. Very little of the administered radiozinc appeared in the bile. The maximum excretion observed for this pathway was 0.4 per cent in 8 days.
3. Radiozinc was also found in large amounts in the juice obtained from an isolated loop of the duodenum.
THE MULTIPLICATION OF BACTERIOPHAGE IN VIVO AND ITS PROTECTIVE EFFECT AGAINST AN EXPERIMENTAL INFECTION WITH SHIGELLA DYSENTERIAE
Authors: Dubos René J. , Straus June Hookey , Pierce Cynthia 
Published: June 2004

1. Anti-Shiga bacteriophage injected into the general circulation can multiply in the brain of mice infected intracerebrally with Shigella dysenteriae.
2. Under proper conditions, the injection of active bacteriophage into the general circulation can protect mice against an otherwise fatal intracerebral infection with Shigella dysenteriae.
3. The protection so induced appears to depend upon the early establishment of a high bacteriophage level in the infected animal.
THE IMMUNOLOGICAL RESPONSE TO INFLUENZA VIRUS INFECTION AS MEASURED BY THE COMPLEMENT FIXATION TEST
Authors: Friedewald William F. 
Published: June 2004

A quantitative complement fixation test with influenza immune sera and virus antigens obtained from allantoic fluid is described. The method utilizes a photoelectric densitometer which provides a simple, objective, and accurate determination of the hemolytic reaction. The enhancement of the hemolytic activity of complement in the presence of serum or allantoic fluid necessitates a preliminary titration of complement in the presence of these agents. An accurate appraisal of the activity of the complement under the conditions of the actual test permits the selection of an optimal amount of complement and greatly increases the sensitivity of the test. The substance (or substances) responsible for the enhanced hemolytic activity of complement has been found in human and many animal sera and in allantoic fluids obtained from the developing chick embryo. It requires the presence of both complement and hemolysin, resists heating at 100°C. for 2 hours, and is dialyzable.
Allantoic fluid or mouse lung preparations of influenza virus contain a complement-fixing antigen which is intimately associated with the virus particle. It sediments in the high speed centrifuge at the same rate as the hemagglutinin and infective particle and, like the latter, is adsorbed by fowl red blood cells and eluted from the cells on standing at room temperature or 37°C. It cannot be separated from the virus particle by repeated washings in the centrifuge or repeated adsorptions with red blood cells; the hemagglutinin and complement-fixing antigen titers remain roughly proportional. This antigen shows a high degree of strain specificity in cross complement fixation tests with PR8, W.S., and swine ferret antisera, and, as found with the neutralization test, it shows little or no strain specificity with human sera. A soluble antigen is also present in influenza virus preparations which can be readily separated from the virus particle by centrifugation. It is not adsorbed by red blood cells. Furthermore, it reacts in lower titer with ferret antisera and usually shows less strain specificity in cross complement fixation tests. In general, allantoic fluid virus preparations contain much less of the soluble antigen than mouse lung extracts.
A KINETIC ANALYSIS OF THE RENIN-ANGIOTONIN PRESSOR SYSTEM AND THE STANDARDIZATION OF THE ENZYMES RENIN AND ANGIOTONASE
Authors: Plentl Albert A. , Page Irvine H. 
Published: June 2004

The physicochemical background of the renal vasporessor system (renin-renin-substrate, angiotinin, angiotonase) is given. The formation and destruction of angiotonin is shown to consist of two consecutive reactions, both of which follow the laws of first order kinetics. Each reaction was studied separately and its reaction constant found to be proportional to the enzyme concentration. Hence these constants should be used to express the activity of the enzymes, renin and angiotonase.
The over-all reaction of a mixture of renin and angiotonase such as occurs in kidney extracts with the α-globulin fraction of serum, viz., rapid increase followed by a slow decline in angiotonin concentration, was found experimentally to correspond closely to the theoretical values calculated for such a reaction. The curve obtained also satisfyingly explains the characteristic pressor response to the intravenous injection of renin. An accurate method for the determination of renin in the presence of angiotonase is presented.
WATER METABOLISM IN HYPERTENSIVE RATS
Authors: Oster Kurt A. , Martinez Oscar 
Published: June 2004

The water intake in hypertensive rats was investigated. Rats made hypertensive by renal ischemia increased their water consumption by 75 per cent over the preoperative level. Polyuria was associated with this polydipsia and the independence of these occurrences from a number of other factors was demonstrated.
It was found that the presence of a normal kidney exerted a compensatory influence which may mask either hypertension or polyuria or both. The appearance or exacerbation of the changes upon removal of the normal kidney, on the one hand, and the elimination or mitigation of the symptoms upon removal of the ischemic kidney on the other support the view that the changes observed cannot have been due to passive elimination of the kidney tissue by ischemia, but to active malfunction of the renal, and especially the tubular, mechanism upon withdrawal of oxygen. The view is put forward that polyuria is a primary sequel of ischemia rather than secondary to the intra- and extrarenal effects of hypertension. A number of concomitant observations are in harmony with this hypothesis.
POLIOMYELITIS IN THE CYNOMOLGUS MONKEY
Authors: Faber Harold K. , Silverberg Rosalie J. , Dong Luther 
Published: June 2004

1. Cynomolgus monkeys were subjected to a series of non-traumatic exposures of the mucous membranes of the alimentary tract, designed to test the relative permeability to poliomyelitis virus of its upper and lower portions.
2. In the first stage, dried poliomyelitis virus of tested potency was administered in fat-covered capsules to 26 monkeys in such a way as to avoid contamination of the oropharynx but to permit thorough exposure of the gastro-intestinal mucosae. No clinical evidence of poliomyelitic infection appeared.
3. Subsequent application of small amounts of virus to the tongues of 18 of the same monkeys caused paralytic poliomyelitis in one of them.
4. Virus given subsequently by enema to 11 of the monkeys caused no clinical manifestations of poliomyelitis.
5. Of 7 monkeys later treated with virus by oronasal spraying, one developed typical preparalytic signs of infection, and the distribution of lesions indicated that entry had occurred through the afferent nerves of the oropharynx and, possibly, the esophagus.
6. The 6 surviving monkeys were exposed to virus by inhalation. One of them developed paralytic poliomyelitis by olfactory entry. The others appeared to have acquired some resistance to infection.
7. The 5 surviving monkeys were inoculated intracerebrally, as a test of immunity. One of them developed paralytic poliomyelitis. The other 4 showed no clinical signs of infection, but all had typical lesions of varying extent and intensity in the central nervous system.
8. A histological examination of the peripheral nervous ganglia in 12 of the exposed monkeys sacrificed at various stages of the experiments revealed lesions compatible with poliomyelitis in all. Ganglia connected with the head alone (Gasserian, cervical sympathetic) were more constantly and, on the average, more severely involved than the celiac, which is connected only with the intestine.
9. While the celiac ganglion was involved in 7 cases, no evidence was found of the spread of infection from it to the spinal cord.
POLIOMYELITIS IN THE CYNOMOLGUS MONKEY
Authors: Faber Harold K. , Silverberg Rosalie J. , Dong Luther 
Published: June 2004

1. Repeated non-traumatic exposures to poliomyelitis virus of the mucous membranes of the upper respiratory tract and of various portions of the alimentary tract in 5 cynomolgus monkeys, extending over a period of 9 to 14 months, were followed by a definite, though limited resistance to intracerebral inoculation to the homologous strain of virus in 4 of them. Only one monkey developed paralysis (20 per cent incidence) and the other 4 remained free of signs and symptoms of the disease. 92 per cent of 25 previously untreated monkeys developed paralysis with the same strain after intracerebral inoculation.
2. Microscopic examination of the central and peripheral nervous systems of the 4 non-paralytic cases revealed in all instances typical lesions in the central nervous system descending from the level of inoculation into the brain-stem but in only 2 into the spinal cord and then only in limited, small areas. Lesions were found in the peripheral ganglia in all animals which corresponded in distribution with the surface membranes previously exposed to virus. No lesions were found in the central nervous system indicative of invasion preceding the intracerebral inoculation.
3. Our observations point to the acquisition by the immune animal, as a result of surface exposure, of the power to limit the spread of infection in the central nervous system rather than of the capacity entirely to prevent implantation and multiplication of virus.
4. This limitation of spread, it is suggested, resembles the tendency so commonly seen in human poliomyelitis of the disease to "halt" at some stage of its evolution, resulting in the various clinical gradations in extent and severity of involvement (subclinical, abortive, non-paralytic, mild paralytic forms, etc.)
5. The experimental methods of exposure, previous to intracerebral inoculation, employed in our study are compared with the natural exposures of human beings during the course of life, which, as age advances, lead to increasing resistance to poliomyelitis and to an increasing incidence of specific neutralizing antibodies in the blood.
6. The mechanism of resistance is obscure. It may be related to the continuing presence of infection in the peripheral ganglia but this is as yet unproved.
THE SEROLOGICAL DIAGNOSIS OF RELAPSING FEVER
Authors: Stein George J. 
Published: June 2004

1. Spirochetes of relapsing fever have been separated from the blood of heavily infected mice and rats by hemolysing with saponin, followed by repeated washing of the spirochetal suspension with physiological saline.
2. Spirochetes obtained in this manner appear to have broad antigenic specificity. Antigens of this type fixed complement in the presence of serum obtained from man or animals infected with one or other of the recognized strains or "species" of relapsing fever spirochetes. Macroscopic agglutination of the antigens likewise was observed with sera from the same sources.
3. Positive serological reactions were not observed with convalescent sera obtained following infection with other diseases, for example, typhus fever, malaria, Rocky Mountain spotted fever, Weil's disease, syphilis, and typhoid fever. Hyperimmune sera prepared against other pathogens also failed to react with the relapsing fever antigens.
4. No apparent change in the antigen occurred following storage in the ice box for as long as 4 months.
5. The results indicate that treatment of the spirochetes of relapsing fever with saponin yields a relatively stable antigenic preparation which may prove useful in the serological diagnosis of this disease.
FATAL MURINE TYPHUS INFECTION IN THE dba STRAIN OF MICE, WITH OBSERVATIONS ON STRAIN VARIATION IN SUSCEPTIBILITY
Authors: Moragues Vicente , Pinkerton Henry 
Published: June 2004

Injected intracranially in the dba strain of mice, murine typhus rickettsiae caused a serially transmissible meningoencephalitis similar to that produced by psittacosis and certain other viruses. All injected mice of this strain suddenly became ill and approximately half of these animals died on the 5th and 6th days after injection. Swiss mice injected in parallel series showed illness in only a few animals, and no deaths occurred. These experiments were carried out at room temperatures ranging from 60–80°F.
After intraperitoneal injection, a uniformly fatal rickettsial peritonitis developed in all dba mice kept at environmental temperatures of 65–73°F. or 70–80°F. Death occurred between the 3rd and 7th days after injection, depending somewhat on the dosage used. Among Swiss, brown agouti, and A albino mice injected in parallel series, the mortality was less than 60 per cent. These experiments indicate that mice of the dba strain are much more susceptible to murine typhus than are mice of the other three strains studied.
RELATIONSHIP OF THE VIRUS OF LOUPING ILL IN SHEEP AND THE VIRUS OF RUSSIAN SPRING-SUMMER ENCEPHALITIS IN MAN
Authors: Casals J. , Webster L. T. 
Published: June 2004

An experimental study of three strains of Russian spring-summer encephalitis virus and one of louping ill virus has yielded the following results:—
1. The sera of mice hyperimmunized to the viruses of Russian encephalitis and louping ill respectively have produced complement fixation with both antigens in almost precisely the same titer.
2. In neutralization tests hyperimmune sera against the Russian virus strains protected against louping ill virus to the same extent as against the Russian virus strains. Conversely, hyperimmune sera against the louping ill virus protected against the Russian viruses, although to a less degree than against louping ill virus.
3. In cross-resistance tests in mice, a vaccine consisting of formolized Russian virus gave strong protection against this latter and moderate protection against louping ill virus. Formolized louping ill virus gave moderate protection against infection with louping ill and considerably less against the Russian virus.
4. Serum from an individual recovered from a laboratory infection with louping ill virus contracted in 1933 gave positive complement fixation and neutralization tests with the Russian spring-summer encephalitis, as well as with louping ill virus.
5. Serum from a patient who became infected with either Russian or louping ill virus or both while working with the viruses in the laboratory in the fall of 1942, gave positive reactions on complement fixation and neutralization tests against them both.
6. No such similarities have been found with other central nervous system viruses. Hence it would appear that they are specific.
STUDIES ON THE ANTIGENIC COMPOSITION OF GROUP A HEMOLYTIC STREPTOCOCCI
Authors: Stewart Walter A. , Lancefield Rebecca C. , Wilson Armine T. , Swift Homer F. 
Published: June 2004

1. The occurrence of closely related T antigens in the series composed of types 15, 17, 19, 23, and 30 accounts for most of the cross reactions observed among these types. Similarly T antigens, unrelated to the first series but mutually related, occur in a second series comprising types 4, 24, 26, 28, 29, and 46.
2. Matt variants of each of the eleven types studied possess type-specific M antigens demonstrable either by precipitin or agglutinin reactions.
3. In seven of these types, strains have been encountered which do not possess the T antigen usually associated with the type in question.
4. Procedures are outlined in the appendix for preparing specific antisera for the classification of these types by the slide agglutination technique.
DEPRESSION OF ANAEROBIC GLYCOLYSIS OF EMBRYONIC TISSUE BY WESTERN STRAIN OF EQUINE ENCEPHALOMYELITIS VIRUS. PREVENTION OF THIS EFFECT BY SPECIFIC IMMUNE SERUM
Authors: Victor Joseph , Huang C. H. 
Published: June 2004

Studies were made on the effect of mixing the Western strain of equine encephalomyelitis virus (W.E.E.) and embryonic tissue on the rate of anaerobic glycolysis of the tissue. Whole chick embryo, chick embryo from which brain and spinal cord had been removed, and embryonic skeletal muscle were employed.
1. W.E.E. virus depressed the rate of anaerobic glycolysis of embryonic tissues within 2 days after its addition to the tissue. The decrease in anaerobic glycolysis varied from 17 to 82 per cent and was apparent 2 to 4 days after the addition of the virus. No significant effect of the virus was observed 4 hours and 6 days after mixing it with the tissue.
2. Anti-W.E.E. immune serum prevented the inhibiting action of W.E.E. virus on the anaerobic glycolysis of embryonic skeletal muscle.