bluuebunny/crossref_metadata_2025_split huggingface dataset:
THE NEOPLASTIC POTENTIALITIES OF MOUSE EMBRYO TISSUES
Authors: Smith William E. 
Published: June 2004

Epithelial tumors have been readily obtained by the implantation of embryo stomach tissue together with olive oil containing methylcholanthrene (with or without Scharlach R) in adult mice of homologous strain. The implanted tissue from the squamous portion of the stomach rapidly encysted the oil, and benign and malignant papillomas and squamous cell carcinomas soon arose from the stratified squamous lining of the cysts. Bits of the glandular portion of the stomach also formed cysts, but the gland cells underwent metaplasia in response to the carcinogen, altering first to transitional epithelium and then to a stratified squamous layer. So swiftly did these changes take place that nearly all of the tumors took origin from epithelium that had already become stratified and squamous, and the growths themselves were of this type. A single transitional cell carcinoma and an adenoacanthoma were procured, but no adenocarcinomas; nor did any benign papillomas develop, though they often resulted from the action of methylcholanthrene on the squamous portion of the embryo stomach. Search failed to disclose any distinctive precancerous changes in the gastric tissue. Five of the cancers were transplanted and they grew in every host.
No tumors arose from any of the numerous control implants. Those consisting of glandular tissue formed cysts lined partly with columnar epithelium secreting mucus and partly with tubular glands equipped with chief and parietal cells in good condition. Pepsin and rennin were found in the fluid contained in these cysts, but no free hydrochloric acid. The enzymes were present also when the cysts contained methylcholanthrene and the glands had not yet been wholly replaced by metaplastic epithelium.
The tumors appeared months sooner than when methylcholanthrene is injected into the stomach of adult animals or given by mouth; some of them were well established after 5 or 6 weeks. They arose regularly when the requisite experimental conditions were provided. The utilization of transplanted embryo tissue provides a means whereby gastric tumors free from bacterial infection can be procured swiftly and easily.
THE ANTIBACTERIAL PROPERTIES OF SULFUR
Authors: Weld Julia T. , Gunther Anne 
Published: June 2004

1. Saturated solutions of sulfur in alcohol (alcohol-sulfur) when diluted with broth are inhibitory to the growth of various Gram-positive bacteria and to C. hominis. By an arbitrary method of unitage with S. aureus as the test organism, our alcohol-sulfur contains 1,600 to 2,000 units per cc. and one unit contains between 0.24 and 0.34 gamma sulfur. The activity of a preparation is in general directly proportional to its sulfur content.
2. Solutions of sulfur in carbowax (carbowax-sulfur) when diluted with broth are likewise inhibitory to the growth of various Gram-positive bacteria and to C. hominis. When S. aureus is used as test organism, 1 unit contains between 0.1 and 0.2 gamma sulfur. The activity of these preparations is also in general directly proportional to their sulfur content.
3. Carbowax-sulfur when incorporated in agar in 1–500 to 1–2,000 dilution inhibits the growth of various Gram-positive aerobic and anaerobic bacteria, C. hominis, and certain dermatophytes.
4. Our experiments appear to show that both alcohol-sulfur and carbowax-sulfur owe their inhibitory properties to the sulfur particles that are dispersed throughout the medium when these sulfur preparations are diluted with broth. The inhibitory effect of these particles may or may not be due to a combination of the sulfur particles with substances in the medium in which they are suspended.
5. Evidence suggests that the activity of both alcohol-sulfur and carbowax-sulfur is due to sulfur in the same form. The inhibitory effect is characterized by prolonged bacteriostasis with similar activity over a wide range of dilutions.
There is no evidence of true bactericidal action even with the highest concentrations used.
INFLUENCE OF ANESTHESIA ON EXPERIMENTAL NEUROTROPIC VIRUS INFECTIONS
Authors: Sulkin S. Edward , Zarafonetis Christine 
Published: June 2004

1. Experimental neurotropic virus infections previously shown to be altered by ether anesthesia are caused by viruses destroyed in vitro by anesthetic ether; this group includes the viruses of Eastern equine encephalomyelitis, Western equine encephalomyelitis, and St. Louis encephalitis.
2. Experimental neurotropic virus infections which were not altered by ether anesthesia are caused by viruses which are refractory to the in vitro virucidal activity of even large amounts of anesthetic ether; this group includes the viruses of poliomyelitis (Lansing) and rabies.
3. Quantitative studies of the in vitro virucidal activity of ether indicate that concentrations of this anesthetic within the range found in central nervous system tissues of anesthetized animals possess no virucidal activity.
4. The lowest concentration of ether possessing significant virucidal capacity is more than fifteen times the maximum concentration of the anesthetic tolerated by the experimental animal.
5. Concentrations of ether 50 to 100 times the maximum amount tolerated by the anesthetized animal are capable of destroying large amounts of susceptible viruses, the average lethal dose (LD50) being reduced more than 5 log units.
6. On the basis of the studies presented in this report, it cannot be concluded that direct virucidal activity of ether is not the underlying mechanism of the inhibition by anesthesia of certain experimental neurotropic virus infections. Indirect inhibition of the virus by the anesthetic through an alteration in the metabolism of either the host cell or the host animal as a whole appears at this point to be a more likely possibility.
IMMUNOCHEMICAL STUDIES ON BLOOD GROUPS
Authors: Kabat Elvin A. , Bendich Aaron , Bezer Ada E. , Beiser Sam M. 
Published: June 2004

1. Blood group substances have been prepared from human saliva, stomach, and amniotic fluid from individuals of blood group A1 and A2. Several of the saliva samples were obtained from individuals shown to be heterozygous, A1O.
2. The purified blood group A substances from human sources were similar in nitrogen, glucosamine, reducing sugar, and acetyl content. The A1 and A2 substances differed in optical rotation. All of the human A samples were levorotatory while those from hog stomach were dextrorotatory.
3. By two immunochemical criteria the various human preparations could be shown to fall into distinct groups, with respect to purity. The best products showed maximal activity and almost all of their glucosamine was specifically precipitable by anti-A. These samples of human A substance were only about one-half as effective in precipitating antibody to hog A substance formed in man as was homologous hog A substance although the same total amount of antibody was precipitable by excess of either antigen.
4. Human blood group A1 substance was found to be antigenic in individuals of blood groups B and O but was not as good an antigen as hog A substance.
RELATION OF IRON SALTS TO INHIBITION OF GLYCOLYSIS BY THEILER FA VIRUS OF MOUSE ENCEPHALOMYELITIS
Authors: Racker E. , Krimsky I. 
Published: June 2004

1. Brain homogenates of mice infected with the Theiler FA strain of mouse encephalomyelitis virus show marked inhibition of glucose phosphorylation.
2. A similar effect can be obtained by incubating normal brain homogenates with small amounts of ferrous sulfate.
3. Partially purified preparations of Theiler FA virus contain iron in amounts corresponding to their inhibitory effect on brain glycolysis. The virus preparations were purified by chemical fractionation and differential centrifugation and were dialyzed against potassium cyanide or pyrophosphate and potassium chloride for several days before they were analyzed for iron content.
4. The inhibitory effect of the virus preparations and of ferrous sulfate has been shown to be dependent on a heat-labile factor present in normal brain ("inactivating factor").
5. The glycolytic activity of brain homogenates of mice infected with the Theiler FA virus can be restored by addition of a factor prepared from rabbit muscle extract. This "restoring factor" is non-dialyzable and is heat-labile. It has no hexokinase or phosphohexokinase activity. Its restoring activity is destroyed by the "inactivating factor" present in brain.
TOLERANCE TO BACTERIAL PYROGENS
Authors: Beeson Paul B. ,   With the Technical Assistance of Elizabeth Roberts
Published: June 2004

In experiments designed to elucidate the mechanism by which tolerance to bacterial pyrogens is developed, the following observations were made:
1. Animals whose febrile reactions to bacterial pyrogens were markedly diminished, as a result of repeated injections, showed increases in response following R-E blockade.
2. Pyrogenic substances disappeared from the circulating blood more rapidly in rabbits rendered pyrogen-tolerant than in normal animals. Lack of specificity was shown by the fact that rabbits previously injected with Eberthella typhosa bacterial vaccine were able to remove the pyrogens of Serratia marcescens and Pseudomonas aeruginosa from their blood more rapidly than normal animals.
3. R-E blockade-retarded the speed of disappearance of pyrogens from the circulating blood of animals which had been rendered relatively tolerant by previous injections of these substances.
A possible mechanism for the development of unresponsiveness to bacterial pyrogens is suggested.
CHANGES IN THE PLASMA PROTEIN PATTERN (TISELIUS ELECTROPHORETIC TECHNIC) OF PATIENTS WITH HYPERTENSION AND DOGS WITH EXPERIMENTAL RENAL HYPERTENSION
Authors: Lewis Lena A. , Page Irvine H. 
Published: June 2004

The plasma protein pattern of patients with uncomplicated essential hypertension showed only slight variations from the normal while that of patients with severely malignant hypertension showed marked shifts. The fibrinogen and ß-globulins were usually elevated beyond the normal range and the albumin decreased. In less severely malignant hypertension, the changes were less marked.
In dogs with experimental renal hypertension, the γ-globulin level was greatly elevated, and in one animal exhibiting the malignant syndrome ß-globulin and fibrinogen were also increased.
Elevation of ß-globulin seems in some manner associated with the occurrence of severe vascular disease.
ANTIPROTEINS IN HORSE SERA
Authors: Treffers Henry P. , Heidelberger Michael , Freund Jules 
Published: June 2004

1. Two horses were injected subcutaneously with alum-precipitated rabbit serum albumin.
2. The resulting antibody resembled diphtheria antitoxin and anti-egg albumin in the horse in giving a sharp zone of flocculation with antigen, in being water-soluble, in reactivity toward an anti-antibody rabbit serum, and in its electrophoretic properties.
3. The effect of continued immunization, and of variation in volume and temperature on the reactivity of the antibody are discussed.
4. Intravenous injection of the same antigen into horses did not give rise to detectable amounts of antibody of the same type.
THE TOXIC ACTION OF PREPARATIONS CONTAINING THE OXYGEN-LABILE HEMOLYSIN OF STREPTOCOCCUS PYOGENES
Authors: Bernheimer Alan W. , Cantoni G. L. 
Published: June 2004

1. The susceptibility of mice to the lethal effect of preparations containing the oxygen-labile hemolysin (streptolysin O) of group A hemolytic streptococci has been studied. Injection of a single sublethal dose of the streptococcal preparation causes the development of resistance to the effect of a lethal dose injected subsequently.
2. Resistance is demonstrable 3 to 6 hours after the injection of the streptococcal preparation, persists for approximately 30 hours, and then disappears.
3. Resistance induced by the streptococcal preparation, although relatively specific, is directed not only against the streptococcal preparation but also against saponin. Mice made refractory to the streptococcal preparation and to saponin exhibit normal susceptibility to a number of other toxic agents, with the possible exception of the alpha toxin of Cl. welchii.
4. Mice injected with a sublethal dose of saponin develop resistance to the effect of a lethal dose of either saponin or the streptococcal preparation.
5. Resistance depends upon processes distinct from those underlying classical antitoxic immunity.
THE SUSCEPTIBILITY OF INFANT RHESUS MONKEYS TO POLIOMYELITIS VIRUS ADMINISTERED BY MOUTH
Authors: Horstmann Dorothy M. , Melnick Joseph L. , Ward Robert , Sá Fleitas M. José 
Published: June 2004

Although rhesus monkeys have been generally regarded as refractory to infection with poliomyelitis virus administered by the oral route, two of seven infant rhesus developed paralytic poliomyelitis when fed murine-adapted strains of virus. Preliminary intranasal treatment with zinc sulfate and negative serial sections of the olfactory bulbs of the positive animals ruled out the possibility that infection occurred by way of the olfactory pathway.
Studies on the distribution of virus in the tissues of the infected animals yielded positive results in one animal only. In this instance, virus was widely distributed throughout the body being isolated from spinal cord, buccal mucosa, duodenal wall, colon contents, superficial lymph nodes, spleen, heart, and adrenals.
STEPWISE INTRATYPE TRANSFORMATION OF PNEUMOCOCCUS FROM R TO S BY WAY OF A VARIANT INTERMEDIATE IN CAPSULAR POLYSACCHARIDE PRODUCTION
Authors: MacLeod Colin M. , Krauss Marjorie R. 
Published: June 2004

1. A variant intermediate between the classical R and S forms has been isolated by selective procedures from a rough strain of pneumococcus originally derived from Type II S.
2. The intermediate variant D39/Int53 is avirulent for mice, forms rough colonies, and does not possess a demonstrable capsule. However, it synthesizes SSSII which is immunologically indistinguishable from that produced by fully encapsulated pneumococcus Type II, though in much smaller amount. The polysaccharide is present as a surface component and as it exists in the cell is highly antigenic for rabbits.
3. An extract of the intermediate variant causes the transformation in vitro of an R strain into a variant resembling the intermediate in SSSII production but without any apparent alteration in the colonial characteristics of the R variant.
4. The intermediate variant is convertible in vivo, into a fully encapsulated strain of pneumococcus Type II. Transformation of the intermediate to a heterologous type of pneumococcus (Type III) was unsuccessful.
5. A method is described for the preparation of transforming extracts of pneumococci utilizing the massive growth of the organisms obtained in the presence of a large concentration of glucose.
PREPARATION FROM HUMAN RED CELLS OF A SUBSTANCE INHIBITING VIRUS HEMAGGLUTINATION
Authors: deBurgh Patrick M. , Yu Pen-Chung , Howe Calderon , Bovarnick Max 
Published: June 2004

Methods have been described for the extraction and purification of an agent inhibiting the hemagglutination of red cells by influenza (PR8) and mumps viruses. Human red cells have served as the chief source of the inhibitor but the latter has also been found in human lung.
The active extracts have been purified to the extent that 0.1 gamma of material suffices to inhibit one hemagglutinating dose of virus. Incomplete chemical characterization of the most highly purified fractions available indicates the presence of 2.6 per cent nitrogen, at least 50 per cent of polysaccharide, and no phosphorus. In the ultracentrifuge the purified preparation behaves as a polydisperse macromolecular substance.
The active material can be obtained from red cell stroma in an ether- and chloroform-soluble form which, on further treatment, can be converted into chloroform-insoluble material. It is possible that the former represents more closely the virus receptor as it exists in the red cell.
The purified inhibitor is inactivated on incubation with the virus at 37°C. The nature of this effect is being investigated.
STUDIES IN THE RELATION OF THE HEMOLYTIC STREPTOCOCCUS TO RHEUMATIC FEVER
Authors: Harris T. N. 
Published: June 2004

Complement-fixing antibodies to the cytoplasmic particles (CP) and to the S fraction of streptococcal nucleoproteins are present in normal human sera, the range of concentrations varying among the age groups.
The titer of these antibodies rises between the first half-week and the 3rd week of scarlet fever, in more than 80 per cent of the cases. The titers then remain elevated for at least 4 months.
In children, 91 per cent of the normal sera examined showed anti-CP titers up to 32; 87 per cent of sera in active rheumatic disease had titers above this level. Corresponding data with S fell in the same range of percentage distribution.
Anti-CP and anti-S titers remained elevated long after the rheumatic process had reached quiescence. No correlation of serologic titer with the degree of clinical activity was found in the case of either antibody.
NUTRITION OF THE HOST AND NATURAL RESISTANCE TO INFECTION
Authors: Schneider Howard A. 
Published: June 2004

The observation has been confirmed that the property of a "natural" diet of whole wheat and whole dried milk to promote a higher survival rate among a stock of outbred, genetically heterogeneous W-Swiss mice subjected to S. typhimurium infection, over that promoted by a "synthetic" diet, is dependent upon a relationship between avirulent and virulent members of the pathogen population.
This relationship has now been analyzed in terms of number (interacting doses) and time (interval between interacting doses). On any given diet survivorship has been demonstrated to be a function of the host's experience of the avirulent pathogen; increasing experience, either in dose or time, resulted in increasing survivorship. For a given set of interacting avirulent-virulent doses the rate at which survivorship rose was greater when the "natural" diet was fed than when the "synthetic" diet was fed. This difference in survivorship-increase rates gave rise to differences in survivorship between the two diets. These dietary differences ranged from minimal to maximal with increasing time, and then, as still more time elapsed, back to minimal again. In consequence an optimum time interval was found at which the dietary effect was maximal. This time interval was chosen for assay purposes. The assay method thus arrived at was tested repeatedly for reproducibility, and statistical analysis showed it to be reliable and capable of demonstrating a mean dietary difference in survivorship of 55 per cent.
The nature of the relationship established between avirulent and virulent S. typhimurium in mice has been discussed.
EXPERIMENTS ON THE RÔLE OF THE CHICKEN MITE, DERMANYSSUS GALLINAE, AND THE MOSQUITO IN THE EPIDEMIOLOGY OF ST. LOUIS ENCEPHALITIS
Authors: Smith Margaret G. , Blattner Russell J. , Heys Florence M. , Miller Albert 
Published: June 2004

The present experimental results concern primarily the question, whether or not mosquitoes feeding on chickens having viremia, as a result of the bite of infected mites, can acquire the virus of St. Louis encephalitis and whether or not mosquitoes thus infected, can transmit the virus to chickens and hamsters.
During the course of the investigation, 7 species of mosquitoes of 3 genera were infected with the virus in one or two or all of three ways: by feeding on a suspension of infected mouse brain tissue, by feeding on chickens in which viremia had been produced by subcutaneous inoculation of virus, and by feeding on chickens having viremia as a result of the bite of infected mites. These mosquitoes transmitted the virus to chickens at periods varying from 5 to 33 days after the infective meal.
The virus of St. Louis encephalitis was transmitted to hamsters by Culex pipiens at periods varying from 4 to 27 days after feeding on chickens having viremia as a result of the bite of infected mites. While viremia was demonstrated readily in hamsters, signs of encephalitis did not develop.
In all transmission experiments the method of chorioallantoic passage proved necessary for the demonstration of viremia.
A concept of the epidemiology of St. Louis encephalitis is presented: two blood-sucking vectors may be involved, one an arachnid, the mite, maintaining the virus in nature by transovarial passage, and the other, an insect, the mosquito, which carries the infection from birds to other vertebrates including man.
EFFECT OF ENZYME INHIBITORS AND ACTIVATORS ON THE MULTIPLICATION OF TYPHUS RICKETTSIAE
Authors: Greiff Donald , Pinkerton Henry 
Published: June 2004

A technique is described for measuring the oxygen uptake of embryonate eggs. Statistical analysis has shown that the method is reliable and accurate. Determinations were made on groups of 15 to 20 eggs, in order to average out individual biological variations. Reduction of the CO2 tension and relative humidity to approximately zero previous to analysis has been found to be desirable. The oxygen consumption of normal and typhus-infected eggs, untreated and treated with agents previously found to inhibit or enhance rickettsial growth has been studied.
Rickettsial infection caused a slight but significant increase in the rate of oxygen consumption on the 4th day after inoculation, followed by a rapid drop in the rate as the infection developed. The evidence suggests that low concentrations of rickettsial toxins may stimulate respiration, while higher concentrations depress respiration and lead eventually to embryonic death.
PABA, which is rickettsiostatic, markedly increased the oxygen uptake of normal eggs, the effect appearing 4 days after injection and lasting for about 4 days. Thereafter, the rate fell below that of the untreated eggs. In typhus-infected eggs, PABA had similar effects, but the oxygen consumption reached much higher levels. A possible explanation of this fact is suggested. MABA and OABA, which are not rickettsiostatic, did not increase oxygen uptake; in fact they depressed cellular respiration moderately, OABA being more active in this way than MABA. These two compounds may compete with PABA for a position in some respiratory enzyme system.
Potassium cyanide, which enhances rickettsial growth, caused, in concentrations not lethal to the embryos, a moderate drop in the oxygen consumption of normal eggs, the effect starting almost immediately after injection and lasting usually for 9 days. In infected eggs, its effect was more striking. It is probable that rickettsial toxins and KCN act synergistically to depress cellular respiration.
When PABA and KCN were injected simultaneously, the stimulating effect of PABA on respiration predominated. The resulting level of oxygen consumption, though lower than that resulting from PABA alone, was still high enough to inhibit rickettsial growth.
As far as our results go, they support the hypothesis that, within certain limits, rickettsial growth is inversely proportional to the respiratory rate of the host cells, regardless of the factors which determine that rate. It is not yet clear that PABA owes its rickettsiostatic action to its ability to increase cellular respiration, but this assumption seems reasonable as a working hypothesis. The respiratory mechanism in which PABA participates is not as yet known.
Although PABA forms part of the folic acid molecule, folic acid itself, in concentrations corresponding to effective doses of PABA, did not increase cellular respiration or show rickettsiostatic action.