bluuebunny/crossref_metadata_2025_split huggingface dataset:
THE INFLUENCE OF INTRAUTERINE FACTORS ON THE FETAL WEIGHT OF RABBITS
Authors: Rosahn Paul D. , Greene Harry S. N. 
Published: June 2004

Observations were made on 475 fetuses carried by 71 pregnant rabbits. 63 or 88.7 per cent of the 71 does were sacrificed from 28 to 31 days after the last fertile mating, and these does bore 401 or 88.2 per cent of the total of 455 fully developed fetuses. The following information was available with reference to each fetus: age, weight, weight of corresponding placenta, horn, i.e., right or left, presentation, and position or order. The presentation indicated that part, head or breech, which was directed toward the vagina, and position or order, the relative locus of the fetus in the horn, the first position being that nearest the ovary.
As the gestation period approached its normal limit of 31 days, the relative daily increase in mean fetal weight was progressively retarded.
There was no significant difference between the number of fetuses in each uterine horn.
Head presentation was significantly more frequent than breech, but the uterine horn in which the fetus was located had no influence on its presentation.
A greater relative number of breech presenting fetuses was observed in the third position than in the other positions.
Presentation did not exert a significant influence on fetal weight.
Fetal weight at or near term was significantly influenced by the position or order in the uterine horn. In general, the weights of fetuses implanted high up nearest the ovary were greater than those developing nearest the outlet, and fetuses occupying intermediate positions had intermediate weights. When, however, only two fetuses were present in a horn, position had no effect on their weights.
A significant positive coefficient of correlation was observed between fetal and placental weights. Moreover, placental weight was influenced by position in the uterine horn in exactly the same manner that fetal weight was so influenced.
The factors which produced variability in fetal weight at or near term, did not account for the abnormally low birth weights of the dwarf rabbits observed in this laboratory.
THE IMMUNOLOGICAL SPECIFICITY OF STAPHYLOCOCCI
Authors: Julianelle L. A. , Hartmann A. F. 
Published: June 2004

1. Skin reactions to the type specific carbohydrates of Staphylococcus indicate that cutaneous sensitivity to Type B is either extremely rare or nonexistent.
2. Skin reactions to Type A carbohydrate occur in about 12 per cent of normal infants and children and in 65 to 70 per cent of normal adults.
3. Skin reactions to Type A carbohydrate occur regularly in patients with Staphylococcus infection.
4. Skin reactivity is not associated with demonstrable serum precipitins, for (a) normal individuals, though skin reactive, have not been found to possess them, and (b) not all patients with verified infection develop them.
5. The patients elaborating type specific precipitins, who numbered less than 30 per cent in this study, are those with severe, prolonged, or generalized Staphylococcus infection.
6. Specific carbohydrates have not been found in the urine of patients during Staphylococcus infection.
CHEMO-IMMUNOLOGICAL STUDIES ON CONJUGATED CARBOHYDRATE-PROTEINS
Authors: Goebel Walther F. 
Published: June 2004

1. Artificial carbohydrate-protein antigens containing the azobenzylglycosides of glucose and glucuronic acid give rise in rabbits to antibodies which are distinct and immunologically specific.
2. The artificial antigen containing glucuronic acid reacts in high dilutions in antipneumococcus horse sera Types II, III, and VIII. The chemical basis for this serological activity is discussed.
SEROLOGICAL REACTIONS WITH A VIRUS CAUSING RABBIT PAPILLOMAS WHICH BECOME CANCEROUS
Authors: Kidd John G. , Beard J. W. , Rous Peyton 
Published: June 2004

A method has been devised for serological tests with a virus producing rabbit papillomas that become carcinomatous. The discrete character of the growths caused by the virus when suitably diluted fits it notably for quantitative experimentation. It shows no tendency to lie latent in domestic rabbits though it does so on occasion in cottontails, the natural hosts. Sera which partially neutralize it do not alter its character, or attenuate it, but merely cut down the number of its effective entities.
The serum of normal domestic rabbits is ordinarily devoid of neutralizing influence on the virus, but that of animals carrying the papillomas usually exhibits neutralizing power soon after these appear. The rate at which this power increases depends in general upon the amount of papillomatous tissue developing, but exceptions to the rule occur, the presence of fairly large growths being compatible with a lack of such powers in demonstrable amount. Even when the antiviral power is great it has no evident influence on the course of established papillomas, other factors determining whether these enlarge or retrogress. It acts to prevent successful reinoculation of the animal, however.
CHANGES IN THE BONE MARROW AND BLOOD CELLS OF DEVELOPING RABBITS
Authors: Sabin F. R. , Miller F. R. , Smithburn K. C. , Thomas R. M. , Hummel L. E. 
Published: June 2004

1. The full number of erythroid cells in the blood stream of the rabbit is reached by the 3rd week of life.
2. During this period, there is a predominance of erythrogenesis in the bone marrow.
3. During the 2nd week of life the bone marrow is in a state of hyperplasia owing to the needs of the body for blood and the small space available for the marrow.
4. This hyperplasia is reduced as the growth of the bone permits the marrow to spread. The control of the growth of the bones has an important bearing on hematopoiesis.
5. During the first 3 weeks of life, the chemical factors for the multiplication of red cells as well as for the elaboration of hemoglobin become available.
6. The amount of hemoglobin does not increase as rapidly as the number of cells, so that the macrocytic anemia of the fetus becomes reduced. The proportion of hemoglobin per red cell characteristic of the adult rabbit is reached by the 3rd month.
7. Further evidence on the intravascular origin of red blood cells is given.
8. The development of all of the white blood cells, with the exception of the monocyte, goes on at a slower rate than that of the red cells.
9. The monocytes reach their full number in the blood stream in the 1st week of life; granulocytes and lymphocytes by the 5th and 6th months.
10. Each of the three strains of white cells has a different rate of development.
11. The question as to whether the stem cell or primitive cell is identical with the lymphocyte is discussed.
SURVIVAL OF THE VIRUS OF POLIOMYELITIS IN THE ORAL AND NASAL SECRETION OF CONVALESCENTS
Authors: Kramer S. D. , Sobel A. E. , Grossman L. H. , Hoskwith B. 
Published: June 2004

The positive detection of the virus of poliomyelitis in the nasal secretions of 2 children, 16 and 13 days after the onset of the disease, is described. 7 animals which had been inoculated with other concentrates became ill with symptoms and temperature elevations suggestive of poliomyelitis, from 1 to 3 weeks following inoculation, but without definite paralysis. In 2 of these animals which were sacrificed, the histologic findings were compatible with the diagnosis of poliomyelitis but were not typical. Of the serums of the 5 remaining animals 4 failed to neutralize stock virus, whereas the serum of the fifth neutralized the virus on two different occasions. This serum was obtained from a monkey that had been inoculated with concentrated nasal secretions of a child 43 days after the onset of illness.
It is suggested that the present quarantine period of 3 weeks is compatible with the available data. It is further suggested that the methods of procedure described may be useful in similar investigations.
THE COMPLEMENT FIXATION REACTION WITH PNEUMOCOCCUS CAPSULAR POLYSACCHARIDE
Authors: Goodner Kenneth , Horsfall Frank L. 
Published: June 2004

1. Complement is not fixed by immune aggregates resulting from the interaction of pneumococcus capsular polysaccharide and type-specific immune horse serum, although under proper conditions the substitution of immune rabbit serum gives positive results.
2. The negative results with immune horse serum are due to some poorly understood property of the specific antibodies rather than to some heterologous inhibitor present in the serum.
3. It has been shown that with immune rabbit serum-polysaccharide combinations, complement fixation is an adsorptive phenomenon conditioned upon the surface exposure of the immune aggregates.
4. A close parallelism to the selective adsorption of phosphatides by these immune aggregates has been pointed out.
5. In those instances in which complement is fixed this phenomenon must be regarded as tertiary and conditioned by (a) union of antigen and antibody, and (b) particulation.
6. The general significance of complement fixation as applied to bacterial polysaccharides has been discussed.
STUDIES ON NATURAL IMMUNITY TO PNEUMOCOCCUS TYPE III
Authors: Enders John F. , Shaffer Morris F. , Wu Chao-Jen 
Published: June 2004

Among the experimental findings reported in this paper to which we wish to give particular emphasis are the following:
1. The results which follow the intravenous injection into rabbits of two strains of Pneumococcus Type III of different degrees of virulence vary with the state of the capsule. Thus when this structure is completely developed both remain in the blood. A culture of either strain begins to become susceptible to the blood-clearing mechanism contemporaneously with the onset of capsular degeneration and the initiation of other concomitant changes at the surface of the organism (cf Paper II), which occur much earlier with the less virulent strain.
2. When, in either case, removal from the blood stream occurs, this is effected by the phagocytic cells of the body. There is no suggestion that a new or unknown mechanism is involved. The greatest share of the burden is borne by the fixed phagocytic cells of the liver and spleen, and to a less extent by those of the lung and bone marrow. Nevertheless, it has been demonstrated that the polymorphonuclear leucocytes may also participate.
3. Phagocytosis by the leucocytes of the normal animal either in intro or in vivo has been observed only at such a time as the capsule has become impaired. Ingestion of the organisms by the fixed tissue cells appears also to be effective only under the same condition and is accordingly observed with much younger cultures of the less virulent strain.
4. Following their removal from the blood and their accumulation within the fixed phagocytes of the organs, destruction of most of the cocci proceeds within 2 to 4 hours. Both strains are destroyed provided they are in the state favorable to phagocytic attack.
5. Evidence has been presented which indicates that just as in vitro, so in a local area of inflammation within the body, aging with attendant capsular loss and increasing susceptibility to phagocytosis may take place.
6. With organisms from either strain a variable period of lag follows their injection into the blood stream, even when they are introduced in a state of active multiplication and complete encapsulation.
7. Differences in virulence for rabbits of two strains of Pneumococcus Type III do not imply that this animal possesses a defensive mechanism which is absent in other species, since it has been possible to demonstrate similar differences when the organisms are injected intravenously into mice. This fact indicates that the factors determining the degree of virulence of these strains are to be sought in the organisms themselves, rather than in the kind of host.
TISSUE CULTURE STUDIES ON BACTERIAL HYPERSENSITIVITY
Authors: Moen Johannes K. 
Published: June 2004

1. Guinea pigs infected with naturally pathogenic hemolytic streptococci (group C—Lancefield) develop a low grade chronic type of disease characterized chiefly by purulent lymphadenitis.
2. Cutaneous hyperreactivity to a crude streptococcal extract invariably occurred during the course of this infection.
3. Production of antibodies (precipitins and agglutinins) was studied.
4. The hemolytic streptococcal extract had a specific toxic effect, when tested in vitro, on cells from infected animals; this was shown by microscopic evidence of cellular injury, and by quantitative inhibition of cellular migration and growth. The specificity of the reaction was proven by testing with other cytotoxic substances.
5. There was no parallelism between skin hypersensitivity and humoral antibody titer.
6. There was no correlation between the degree of skin reactivity to the bacterial extract and the degree of sensitivity of splenic cells to the toxic action of the same extract in vitro.
7. Comparison of cellular sensitivity to tuberculin with cellular sensitivity to streptococcal extract in cultures of guinea pig tissues showed that the former was more intense and was more persistent on prolonged growth in vitro.
OBSERVATIONS ON THE RELATION OF THE VIRUS CAUSING RABBIT PAPILLOMAS TO THE CANCERS DERIVING THEREFROM
Authors: Rous Peyton , Kidd John G. , Beard J. W. 
Published: June 2004

All the strains of the Shope virus thus far tested which give rise to vigorous, progressively enlarging papillomas in domestic rabbits, function as carcinogenic agents by way of these growths. The more pathogenic the virus as evidenced by the brevity of its incubation period and the vigor of the papillomas produced, the sooner and oftener does cancer occur. The number of virus entities contained in the inoculum notably influences the outcome, cancer appearing most frequently in those confluent, papillomatous masses which have resulted from the greatest concentration of the virus material under test. The papillomas experimentally induced by the ordinary inoculation methods are essentially aggregates of proliferating cell families, each the outcome of some primary cell-virus association. Some of these associations are followed more frequently by cancer than others are in the same animal.
Cottontail rabbits, the natural hosts of the virus, are notably resistant to its sustained activity, as compared with domestic rabbits. Though often growing rapidly at first, the papillomas of cottontails soon become relatively inert in most cases, and they usually retrogress, and rarely undergo malignant change. In an instance here reported both a squamous cell carcinoma and a metastasizing sarcoma appeared at the base of some papillomas due to experimental inoculation, which had existed on the ears of a cottontail for nearly 2 years.
The meaning of the phenomena is discussed.
STUDIES ON NATURAL IMMUNITY TO PNEUMOCOCCUS TYPE III
Authors: Enders John F. , Wu Chao-Jen , Shaffer Morris F. 
Published: June 2004

Since there is no evidence for the occurrence of type specific antibody in the normal rabbit and since, as we have shown, the Pneumococcus Type III whether avirulent or virulent is not removed from the blood stream or destroyed when the capsule is intact, the following factors which have been revealed in the course of our work appear to represent certain essential components, if not the complete mechanism, upon which the natural immunity of the rabbit against this organism depends. (a) The elevation of the body temperature after intravenous infection to 41°C. or thereabouts and its maintenance for varying periods. (b) The ability of the phagocytic cells, both fixed and mobile, to attack any cocci which have become vulnerable through the deterioration of capsular integrity. (c) The adjuvant effect of an antibody, reacting with the somatic C carbohydrate, which enhances the phagocytosis of such organisms as no longer possess a completely intact envelope.
Conversely, the varying degrees of virulence for rabbits observed among Pneumococcus Type III strains are based upon: (a) differences in the ability of the organisms to multiply at the elevated temperatures encountered in the infected host. Strains markedly susceptible to the harmful influence of this factor fail to induce a generalized fatal infection. Not all "thermo-resistant" strains are highly virulent, however, and these may contrast sharply with regard to (b) size of the capsule and the ease with which it is impaired or completely lost. The capsules must be maintained intact for a sufficient time until multiplication of the organisms can proceed to such a degree that death of the host results. Avirulent strains even when capable of growth at 41°C. appear to be unable to satisfy this requirement.
The differences in virulence of various strains apparently conditioned by these factors are not limited solely to the case of the rabbit, since for at least two strains similar differences in virulence have been shown to exist when the intravenous route of infection is employed in mice.
IMMUNOLOGICAL AND CHEMICAL INVESTIGATIONS OF VACCINE VIRUS
Authors: Parker Robert F. , Rivers Thomas M. 
Published: June 2004

Methods have been described by which the number of elementary bodies present in a suspension can be estimated. It has been shown that by means of replicate counts, in which the Petroff-Hausser chamber was used, a high degree of accuracy can be attained. By means of the Gates densitometer, the number of elementary bodies in a suspension can be determined with a coefficient of variation of about 3.0 per cent. A method has been described by which the accuracy of estimation of the infectious titer of a suspension can be increased without greatly enlarging the number of animals employed. This consists of selecting as the end-point that dilution of virus which on intradermal inoculation in a rabbit would lead theoretically to an equal number of positive and negative results. The statistical advantages of this method have been confirmed by the experiences of other laboratories.
By the application of the methods described, there was shown to be a direct correlation between the number of elementary bodies and the number of infectious units of virus present in a given suspension. At the mean of the distribution this ratio is as the logarithms 9.62 to 8.0. To extrapolate this curve, in order to determine the number of elementary bodies present in a single infectious unit, while tempting, is probably not justifiable. It must likewise be remembered that the data given apply to a particular strain of vaccine virus, and that the number of infectious units has been determined by intradermal inoculation of rabbits. It appears also that this method may be of value in studies of the virulence of different strains of vaccine virus, since by its application one may determine not only the infectious liter of a suspension, but its content of elementary bodies.
In the agglutination reaction it was found that optimum titers of serum were obtained when the test antigen contained from 2.0 x 109 to 1.05 x 1010 elementary bodies per cc. Approximately 1.95 x 108 particles per cc. of suspension were required for the production of visible agglutination.
A HIGH SPEED VACUUM CENTRIFUGE SUITABLE FOR THE STUDY OF FILTERABLE VIRUSES
Authors: Bauer Johannes H. , Pickels Edward G. 
Published: June 2004

1. A high speed centrifuge is described in which the speed is limited only by the strength of the material of which the rotor is made. It carries sixteen tubes, each of which conveniently accommodates 7 cc. of fluid.
2. The centrifuge operates in a very high vacuum and therefore requires only a small amount of driving energy. The arrangement has been found to eliminate the possibility of producing injurious frictional heat.
3. The rotating parts are supported by anair-bearing and are driven by compressed air.
4. The centrifuge has been successfully operated at a speed of 30,000 revolutions per minute, representing a maximum centrifugal force in the fluid of 95,000 times gravity.
5 Celluloid tubes used for centrifugation of fluid at high speeds are described.
6. Experiments are described in which good sedimentation of the yellow fever virus was obtained.
HYPERSENSITIVENESS AND ANTIBODY FORMATION IN TUBERCULOUS RABBITS
Authors: Freund Jules , Laidlaw Elizabeth H. , Mansfield James S. 
Published: June 2004

1. Rabbits infected with bovine tubercle bacilli develop hyper-sensitiveness to an intracutaneous injection of tuberculin. This sensitiveness appears from the 2nd to the 6th week after infection and increases rapidly thereafter. Tests, as a rule, show fluctuation in the intensity of the sensitization. Sensitization is followed by an interval of several weeks preceding death during which the animals fail to react.
2. Rabbits infected with bovine tubercle bacilli form antibodies that fix complement in the presence of tubercle bacilli. The antibodies appear after 2 weeks, increase during 6 to 10 weeks, and persist until the animals die.
3. In the later period of infection the skin fails to react to tuberculin at a time when the serum contains complement fixing antibodies.
LIPIDS AND IMMUNOLOGICAL REACTIONS
Authors: Horsfall Frank L. , Goodner Kenneth 
Published: June 2004

1. Specific precipitates resulting from the interaction of the homologous capsular polysaccharide and Type I antipneumococcus horse and rabbit sera have been analyzed by gasometric micro methods for total nitrogen, lipid nitrogen, and lipid carbon.
2. Lipid may, under certain conditions, form as much as 51 per cent or as little as 4 per cent by weight of specific precipitates.
3. The total lipid content of specific precipitates, within the range studied, is entirely independent of the protein content.
4. Lipid nitrogen forms a very small but detectable portion of the total nitrogen of precipitates.
5. The absolute lipid content of precipitates is a function of the concentration of lipid in the reacting mixture prior to precipitation, and seems to be governed by the laws of adsorption phenomena.
THE RELATION BETWEEN ANTIANAPHYLAXIS AND ANTIBODY BALANCE
Authors: Morris Marion C. 
Published: June 2004

1. Sensitized guinea pigs injected with normal rabbit or guinea pig serum previous to intravenous inoculation of antigen may be protected against a few lethal doses of antigen. The protection is greater with foreign than with homologous serum and appears to be related roughly to the amount of serum introduced.
2. Sensitized guinea pigs injected with antibody-containing serum preliminary to intravenous injection of antigen, show no greater refractoriness to anaphylaxis than do those injected with normal serum.
3. Moreover, in many instances, the injection of an excess of antibody into the circulation of sensitized guinea pigs, leads to an increased susceptibility of these animals to anaphylaxis.
4. These results indicate that an excess of circulating antibody is not responsible for a state of antianaphylaxis, but on the contrary, may contribute toward the anaphylactic reaction itself.
FURTHER STUDIES ON TYPHUS FEVER
Authors: Zinsser Hans , Macchiavello Attilio 
Published: June 2004

1. Guinea pigs can be actively immunized against European typhus fever with homologous formalinized Rickettsia tissue cultures, provided sufficient amounts are injected. The method is suggested for practical application in man.
2. Serovaccination against European typhus fever can be successfully applied to guinea pigs by a variety of methods, the simplest of which consists of the injection of mixtures of virulent defibrinated guinea pig blood and convalescent guinea pig serum taken from 3 to 5 days after defervescence. Similar results can be obtained with mixtures in which tissue culture virus, either with convalescent guinea pig serum or with antimurine horse serum, is used. There is no indication so far that such animals become carriers.
Possible application of these methods to typhus epidemics is discussed.