bluuebunny/crossref_metadata_2025 huggingface dataset:
THE MECHANISM OF ACTION OF 17-HYDROXY-11-DEHYDROCORTICOSTERONE (COMPOUND E) AND OF THE ADRENOCORTICOTROPIC HORMONE IN EXPERIMENTAL HYPERSENSITIVITY IN RABBITS
Authors: Germuth Frederick G. , Oyama Jiro , Ottinger Barbara ,   With the Technical Assistance of Kenneth Q. Grow
Published: June 2004

The concurrent administration of compound E at a daily dosage of 2 mg. per kg. to rabbits receiving daily intracutaneous injections of crystalline egg albumin markedly inhibited the development of anaphylactic hypersensitivity of the Arthus type. ACTH, when given at a similar dosage, produced a much less marked effect. Both hormones suppressed circulating antibody and as with the Arthus reaction, the suppression produced by compound E was much greater than that obtained with ACTH.

When treatment with compound E was started following sensitization, there was a rapid decline in circulating antibody and, if the pretreatment serum antibody was low, there was also a progressive decrease in skin reactivity, becoming negative after 5 days of treatment. When the pretreatment serum antibody concentration was great, so that by the termination of treatment the antibody concentration was still above the level ordinarily sufficient for a maximal skin response, the Arthus reaction was unaffected by treatment.

These considerations as well as the failure of compound E to inhibit the systemic passive Arthus reaction suggest that the inhibitory effect of compound E and ACTH on the development of experimental hypersensitivity results from the hormonal reduction of circulating antibody.

Treatment with compound E had no effect on the rate of disappearance of circulating antibody in the passively immunized rabbit. This finding suggests that ACTH and compound E reduce circulating antibody by inhibiting antibody formation rather than by promoting antibody destruction.

The question is raised as to whether the marked lymphoid atrophy produced by these hormones may be related to the interference with antibody production.
ELECTRON MICROSCOPE STUDY OF RED CELL MEMBRANES AFTER EXPERIMENTAL INFECTION WITH THE VIRUS OF FOOT-AND-MOUTH DISEASE
Authors: Epstein B. , Fonseca N. M. , De Robertis E.
Published: June 2004

Guinea pigs were inoculated with the Vallée O type strain of the virus of foot-and-mouth disease. 42 to 48 hours after inoculation red blood cells washed in saline were found to be infective for normal guinea pigs suggesting that erythrocytes carry virus entities at the height of generalization of the disease. This infection is no longer obtained at 92 hours after inoculation when general symptoms of the disease decline. A replica-transfer technique was developed with which hemolyzed blood smears could be observed under the electron microscope.

By direct examination and also shadow-casting with palladium, normal red cell membranes show only a very fine structure on the surface. Rounded masses of high electron density appear in the ghosts between 24 and 72 hours after inoculation with virus. The number and particularly the density of these masses tend to increase from 24 to 42 and 72 hours. In some cases they are disposed preferentially in single lines forming ring figures; in other cases they are distributed at random. At 42 hours after inoculation it was possible to detect dense particles of 20 to 70 mµ. within the masses. Measurements of 100 masses at 72 hours gave results ranging from 116 to 437 mµ with a mean diameter of 246 mµ. Results based on 105 electron micrographs and on thousands of cells demonstrate that practically all red cell membranes contained dense masses 24 to 72 hours after inoculation. 92 hours after inoculation, coinciding with the disappearance of infectivity of the erythrocytes, the masses could no longer be seen and the membranes looked entirely normal.

Although the facts reported here may be suggestive of a relationship between the dense masses within the red cell membranes and the presence of virus entities in washed erythrocytes, no definite interpretation of these findings is postulated at present.
THE FIRST TWO STEPS OF THE INVASION OF HOST CELLS BY BACTERIAL VIRUSES. II
Authors: Garen Alan , Puck Theodore T.
Published: June 2004

At 37°C., the attachment of T1 virus to its host cell in solution containing 10–3 M CaCl2 or 10–2 M NaCl is extremely rapid (in the neighborhood of 100 per cent collision efficiency) and irreversible. At 1°C., the attachment rate is almost equally rapid but largely reversible.

If a suboptimal concentration of the necessary ions is employed when T2 virus attaches to host cells, the resulting binding is largely reversible, even at 37°C.

Reversible T2 attachment to host cells leaves the cell undamaged and capable of normal reproduction. Irreversible attachment results in death of the cell.

Zn++ exercises a specific inhibitory action on the invasion of E. coli B by T1 virus. The virus can still attach to the host cell at a rate closely approximating the maximum value, but the reaction remains reversible and the cell is protected against permanent damage.

The protective action of the Zn against T1 invasion is exerted through an action on the cell, rather than on the virus.

Studies of the uptake of radioactive Zn65 show that cells become completely immune to T1 invasion when, on the average, 4 x 107 atoms of Zn have been taken up by each cell.

Cells killed by ultraviolet irradiation still bind T1 at the maximum rate, but the reaction is reversible even when taking place at 37°C., in optimum salt concentration.

The tryptophane-deficient mutant of T4 bacteriophage requires its specific cofactor for the initial step of attachment to the host cell.

These experiments support the picture previously developed that virus invasion of host cells consists in an initial, reversible attachment whose properties are those to be expected from the operation of electrostatic binding forces. The step is followed by an enzymatic transformation which is irreversible, strongly temperature-dependent, and in the case of T1 virus, susceptible to inactivation by ultraviolet radiation.

The resistance of mutant cells to specific bacteriophages is of two types, depending on whether the first or second of these steps is blocked.
THE HALF-LIFE OF PASSIVELY ACQUIRED ANTIBODY GLOBULIN MOLECULES IN INFANTS
Authors: Wiener Alexander S.
Published: June 2004

By following the titer of passively acquired Rh antibodies in newborn infants, it is calculated that the half-life of the placenta-passing Rh antibody molecule is approximately 30 days. Evidence is offered that this estimate applies not only to placenta-passing Rh antibodies, but also to other placenta-passing antibodies, and not improbably to serum gamma globulin molecules in general.

Studies on the fate of free Rh antibodies in erythroblastotic babies show that these antibodies often are eliminated no more rapidly in Rh-positive babies than in Rh-negative babies. On the other hand, incompatible alpha and beta antibodies, as a rule, are quickly neutralized and eliminated from the body of newborn infants. These observations provide one explanation for the lower incidence of erythroblastosis due to A-B sensitization in comparison with cases resulting from Rh sensitization.
THE PERSISTENCE IN MICE OF CERTAIN FOREIGN PROTEINS AND AZOPROTEIN TRACER-ANTIGENS DERIVED FROM THEM
Authors: McMaster Philip D. , Kruse Heinz
Published: June 2004

Methods have been devised whereby the persistence of foreign antigens in mice can be detected. A highly diffusible, blue azo dye, echt-säure-blau was coupled to bovine γ-globulin and human serum albumin and injected into the animals. In this way deep blue tracer antigens were obtained. These were promptly stored in cells widely distributed throughout the body, especially in the reticulo-endothelial elements of the liver, spleen and mesenteric lymph nodes. The dye as such was not stored but rapidly excreted.

A blue coloration in the organs just mentioned was still perceptible after 85 to 120 days in the case of the azoglobulin and 36 to 44 days in that of the azoalbumin. To determine whether these substances had actually persisted, as well as to learn how long uncoupled globulin and albumin remained after injection, recourse was had to the phenomenon of reversed passive anaphylaxis, which was found to be characterized by extraordinary changes in the vessels of the ears (EVR) in the mouse, plainly visible under the microscope when called forth by an antiserum specific for the antigen to which the animal had been sensitized. So sensitive is the vascular response that as little as 0.5 to 0.1 µg. of protein as antigen, previously injected into the peritoneal cavity of a 30 gm. mouse, can be detected a few days later by an intravenous injection of antiserum.

By means of the EVR the globulin antigen has been detected in the blood and livers of injected mice for as long as 56 and 101 days, respectively; the albumin and azoalbumin for only 21 and 36 days. In the mesenteric lymph nodes of injected mice the albumin and azoalbumin antigens were found after 42 and 44 days, respectively.

The hepatic tissue and that of the mesenteric lymph nodes of mice injected with azoalbumin, containing in consequence stored blue material, when transferred to recipient mice yielded positive tests for antigen (EVR) as long as blue color could be perceived in these tissues with the unaided eye, or at low magnification. After the color had disappeared from the tissues the transfer tests were found to be negative. This fact speaks for the antigenicity of the colored material.

In summary it is plain that certain antigenic proteins, after introduction into the blood stream of mice, are stored in certain tissues and that they may persist there for weeks or even months, far longer than has generally been supposed. This persistence of antigen within the body, especially after detectable amounts of antigen have apparently disappeared from the blood, provides a reason for prolonged antibody formation, a phenomenon for which no adequate explanation has hereto been offered.
THE OCCURRENCE OF LEUCOCYTE-PLATELET THROMBOSIS IN RHEUMATIC CARDITIS
Authors: Stetson Chandler A.
Published: June 2004

Leucocyte-platelet thrombi, involving the smaller branches of the coronary blood vessels, have been found in the hearts of patients with active rheumatic fever and rheumatic carditis. A consistent correlation has been observed between the existence of these vascular lesions and the presence of typical Aschoff bodies. It is suggested that these cellular thrombi may play a role in the pathogenesis of rheumatic carditis.
STUDIES ON THE CELLULAR IMMUNOLOGY OF ACUTE BACTERIEMIA
Authors: Wood W. Barry , Smith Mary Ruth , Perry William D. , Berry John W.
Published: June 2004

Evidence has been presented that the introduction of large numbers of bacteria into the blood stream causes a widespread intravascular reaction, characterized by the sticking of leucocytes to the endothelium of capillaries, arterioles, and venules. The adherent granulocytes promptly become motile and thus potentially phagocytic. This intravascular leucocytic response affords a rapid and efficient mobilization of a vast number of active phagocytes within the blood stream. In some of the smaller vessels of both the systemic and pulmonary circulation the reaction is accompanied by the deposition of what appears to be intravascular fibrin.

Direct observation by the rabbit ear chamber technique has revealed that leucocytes thus mobilized in small peripheral vessels are capable of phagocyting fully encapsulated Friedländer’s bacilli in the absence of antibody. Ingestion of the encapsulated blood-borne bacteria results from surface phagocytosis and occurs primarily in those vessels in which the flow of blood is either slowed or has temporarily stopped altogether. Leucocytes can be seen to phagocyte the organisms by first trapping them against the walls of the vessels or against adjacent leucocytes. Bacteria caught in the interstices of the intravascular "fibrin" may likewise be immobilized and readily phagocyted. Thus granulocytes, without the aid of opsonins, are able to ingest and destroy encapsulated blood-borne bacteria by the same mechanisms that operate in extravascular tissues.

It is concluded from these studies that intravascular surface phagocytosis by polymorphonuclear leucocytes supplements the well known phagocytic activities of the reticulo-endothelial cells and therefore serves as an important defense of the host in acute infections caused by encapsulated bacteria and complicated by bacteriemia.
INTRACELLULAR LOCALIZATION OF ACID PHOSPHATASE
Authors: Palade G. E.
Published: June 2004

The acid phosphatase activity of rat liver homogenates and of nuclear and cytoplasmic fractions isolated therefrom (by differential centrifugation) was determined biochemically in a series of experiments. For each liver, Gomori's histochemical test for acid phosphatase was run in parallel.

No correlation was found between the biochemical and the histochemical results. According to the former, the enzyme appears to be almost entirely (95 per cent) located in the cytoplasm, while according to the latter, the acid phosphatase is predominantly concentrated in the nuclei and in some peribiliary polymorphic structures identified as myelin figures.

It was found that the precipitaion pattern obtained in the histochemical test does not reveal, as generally assumed, differences in enzyme concentration among the various cell structures, but actually reveals differences in their lead phosphatase affinity. The usefulnes of the histochemical test for intracellular localization studies was found to be further limited by considerable fixation damage and formation of myelin figure artifacts.

The biochemical approach is to be preferred because of better preservation of the material and direct and more reliable methods for the demonstraton of enzyme activity.
THE ANTISTREPTOCOCCAL PROPERTY OF MILK
Authors: Wilson Armine T. , Rosenblum Herman
Published: June 2004

The measurement in vitro of lactenin, the antistreptococcal substance of milk, is affected by the size of the inoculum, the temperature of incubation, and the type of medium employed.

Hemolytic streptococci belonging to the several serological groups vary in susceptibility to lactenin. All group A streptococci, regardless of type, are highly sensitive to it, and milk receiving a small inoculum sterilizes itself within 48 hours or less. By contrast, most strains of groups B, C, D, and E, although they may temporarily be inhibited, ultimately achieve full growth. Strains belonging to groups F, G, H, K, and L vary in sensitivity, some being fully inhibited and others achieving full growth. When streaked on the surface of milk-agar plates and examined at the end of 24 hours the streptococci fall into two classes: sensitive strains which do not produce visible colonies on the plate, and resistant strains which grow excellently. Very few strains show an intermediate degree of sensitivity.

Human and goat milk contain an antistreptococcal principle which appears to be the same as the lactenin of cow milk, since streptococci which are inhibited by milk from one species are inhibited by milk from the others, and vice versa.
THE ANTISTREPTOCOCCAL PROPERTY OF MILK
Authors: Wilson Armine T. , Rosenblum Herman
Published: June 2004

The ability of lactenin to prevent the multiplication of group A streptococci when milk becomes contaminated with that organism accounts in part at least, for the infrequency of milk-borne streptococcal epidemics. From epidemiological studies it has been shown that most such epidemics arise from the consumption of raw milk in which streptococci occur as a result of bovine mastitis due to group A streptococcus. Lactenin fails to prevent the establishment of mastitis due to the group A streptococcus because the milk in the cow's udder is at a low oxidation-reduction potential and the lactenin is inactive.

Lactenin, being destroyed by temperatures of 80°C. or above, is absent from canned and powdered milk. When the latter have been diluted or reconstituted, they can serve as excellent growth media for group A streptococci, and epidemics have occurred as a result of contamination of milk supplies of those types.

The administration of lactenin by mouth or intraperitoneal injection failed to protect mice from peritonitis or subcutaneous infection due to group A streptococcus.
QUANTITATIVE ASPECTS OF THE MULTIPLICATION OF INFLUENZA A VIRUS IN THE MOUSE LUNG
Authors: Ginsberg Harold S. , Horsfall Frank L.
Published: June 2004

Influenza A virus, PR8 strain, increases in amount in the infected mouse lung at a relatively constant rate. When more than 25 M.S.50 doses of virus is inoculated, the rate of multiplication appears to be independent of the amount of virus introduced; has a value of 1,100-fold increase per day. The rate of increase in the pulmonary lesions induced by infection of the mouse lung with PR8 also appears to be relatively constant and independent of the amount of virus inoculated; has a value of 8.5-fold increase per day.

The essential variables in the PR8-mouse lung system appear to be equated satisfactorily by functions which were derived previously (4) during a similar quantitative investigation on pneumonia virus of mice (PVM). Evidence in support of the hypothesis that the processes of multiplication of PR8 and PVM are different in the mouse lung is presented.
THE ENHANCING EFFECT OF URETHANE ON THE SEVERITY OF INFECTION WITH PNEUMONIA VIRUS OF MICE (PVM)
Authors: Mirick George S. , Smith J. MacLean , Leftwich Charles I. , Leftwich William B.
Published: June 2004

Urethane, given parenterally or orally to mice, increased the severity of PVM infection. Not only were the lesions more extensive but mice could be infected with smaller inocula of virus and the multiplication of virus in the lung was enhanced. There was atrophy of lymphoid tissues but no suppression was noted of antibody formation. No relation could be found between PVM infection and the development of pulmonary adenomas in mice.
THE EFFECT OF SPERMINE ON TUBERCLE BACILLI
Authors: Hirsch James G. , Dubos René J.
Published: June 2004

A crystalline substance capable of suppressing the growth of a variety of mycobacteria in vitro has been isolated from extracts of tissue in acidified dilute ethanol. This inhibitory material was found to be equally active against virulent, attenuated, and avirulent variants of human and bovine tubercle bacilli, but had little or no effect on saprophytic mycobacteria and on several non-acid-fast microorganisms under the conditions of the test. Its inhibitory activity on the growth of tubercle bacilli was essentially independent of the size of the inoculum within the limits studied.

The crystalline material appeared to exert a bactericidal action on the susceptible organisms. Tubercle bacilli maintained in the presence of the agent for 4 days failed to grow when transferred to inhibitor-free media.

The findings were not appreciably altered by minor variations in the composition of the medium or by shift in its reaction. When certain preparations of whole serum were used in the medium in place of albumin, no antimycobacterial activity was observed; however, this activity was restored by adding bovine albumin (fraction V) to the media containing whole serum.

By chemical purification and analysis, the inhibitory material was identified as spermine, an organic base widely distributed in animal tissues.
A STUDY OF FIXATION FOR ELECTRON MICROSCOPY
Authors: Palade G. E.
Published: June 2004

Osmium tetroxide fixation of tissue blocks, as usually effected, is preceded by an acidification of the tissue. This acidification is probably responsible for morphological alterations which are notably disturbing in electron microscopy. The acidification and the resulting morphological alterations cannot be prevented by homogenizing the tissue directly in OsO4 solutions or by adding enzyme inhibitors (fluoride, iodoscetamide) to the fixative.

Fixation experiments with buffered OsO4 solutions have shown that the appearance of the fixed cells is conditioned by the pH of the fixative. The quality of fixation can be materially improved by buffering the OsO4 solutions at pH 7.3-7.5, The acetate-veronal buffer appeared to be the most favorable of the buffers tested, Because of these findings, 1 per cent OsO4 buffered at pH 7.3-7.5 with acetate-veronal buffer is recommended as an appropriate fixative for electron microscopy.
EXPERIMENTS ON THE CAUSE OF THE RABBIT CARCINOMAS DERIVED FROM VIRUS-INDUCED PAPILLOMAS
Authors: Smith William E. , Kidd John G. , Rous Peyton
Published: June 2004

Three out of four carcinomas arising from rims-induced, rabbit papillomas have grown well after transplantation to sucklings. Two were propagated serially, and it seems likely that all could have been maintained indefinitely had litters been available of newborn animals of the sort in which they arose. These successes are the more worthy of note because of the well-nigh uniform failure of similar growths on transfer to adults. The tumors enlarged with great rapidity in the sucklings, were extraordinarily destructive, and two of them metastaslzed within a few weeks.

Many efforts were made to extract causative agents from the three carcinomas, on the assumption that these might be due to variants of the Shope virus. Highly favorable conditions for the demonstration of this latter were provided in the tests; yet their outcome was wholly negative although all of the cancers derived from papillomas caused by "recoverable" strains of virus, and although one of them appeared to be consequent upon only the slightest of alterations toward malignancy on the part of the papilloma from which it came. Extracts of another of the cancers, an anaplastic, squamous-cell carcinoma devoid of any morphological sign of the influence of the Shope virus, yielded typical virus papillomas on several occasions. The wholly negative results with the third cancer must be considered in the light of the fact that the "recoverable" strain of virus causing the papilloma from which it originated could no longer be recovered from such growths on collateral test.
THE EMERGENCE OF PSEUDOTUBERCULOSIS IN RATS GIVEN CORTISONE
Authors: LeMaistre Charles , Tompsett Ralph ,   With the Technical Assistance of Kurt Stern
Published: June 2004

The emergence of a severe infection in albino rats during cortisone administration is reported. Evidence is present that the causative agent of the disease was Corynebacterium pseudotuberculosis murium, a microbial species not demonstrably a part of the usual bacterial flora of the host. It has been possible to reproduce the disease in rats by a relatively large infecting inoculum of this strain of Corynebacterium, but the susceptibility of normal rats to infection has been found to be low.

The disease occurred in 41 of 50 rats given cortisone and in 28 of 30 instances in which isolation of the etiologic agent was attempted, this strain of Corynebacterium was recovered. The disease was characterized by widespread necrotizing lesions, with multiple coalescent lesions occurring in the lungs, and similar, though smaller lesions of the pericardium, pleurae, liver, and kidneys. In its gross appearance the pulmonary disease was similar to that of a disseminated, far advanced tuberculous process. The histologic appearance of the lesions, however, was sufficiently distinctive so that they could be readily differentiated from the lesions characteristically produced by Mycobacterium tuberculosis. Moreover, the host-parasite relationship established by the experimental infection with avian tubercle bacilli, was not markedly altered by the factors which led to the emergence of the pseudotuberculosis.

In contrast to the high frequency of pseudotuberculosis in rats given cortisone, no instance of this disease has been encountered in a similar group of animals given large quantities of corticotropin.
ELICITATION OF DELAYED ALLERGIC SKIN REACTIONS WITH HAPTENS: THE DEPENDENCE OF ELICITATION ON HAPTEN COMBINATION WITH PROTEIN
Authors: Eisen Herman N. , Orris Leo , Belman Sidney
Published: June 2004

Eight 2,4-dinitrophenyl compounds with a high degree of configurational uniformity were examined in regard to their ability to elicit delayed allergic skin reactions in guinea pigs and men who had been sensitized by previous exposure to 2,4-dinitrofluorobenzene. Four of the eight compounds produced reactions (elicitors) and four others did not (non-elicitors). It was found that the elicitors combined with protein in vitro and in vivo. The non-elicitors, however, failed to combine in either situation. It is concluded that a necessary condition for the elicitation of delayed allergic skin reactions by haptens is the combination of the latter with skin protein through the formation of bonds of the covalent type. No choice is yet possible amongst the several possible explanations which are advanced to account for the obligatory character of protein combination.
THE EFFECT OF DYES ON THE CALCIFICATION OF HYPERTROPHIC RACHITIC CARTILAGE IN VITRO
Authors: Miller Zelma B. , Waldman Jerome , McLean Franklin C.
Published: June 2004

The calcification of rat hypertrophic cartilage slices in vitro is markedly inhibited by preliminary exposure to metachromatic and other basic dyes. The dyes are effective at 10–3 to 10–4 M in the absence of calcium and phosphate. This inhibition does not occur at the same low dye concentration if calcium and phosphate are present. Neither ion alone is effective in preventing the inhibition.

The inhibitory action can be removed by placing slices which have been treated with basic dye in a solution which contains calcium and phosphate ions, plus an acid dye, Orange G.

Most acid dyes do not inhibit calcification, except at very high concentrations. Alizarin and quinalizarin are exceptional, and produce marked inhibition at 10–3 M, an effect which is perhaps attributable to the tendency of these dyes to form lakes with calcium.

Rachitic cartilage slices which no longer calcify in inorganic phosphate as a result of treatment with basic dyes show normal calcification in the presence of organic phosphate esters.

These results are discussed in terms of the possibility that chondroitin sulfate ester participates in normal calcification.
STUDIES ON THE INHIBITION OF PROTEOLYTIC ENZYMES BY SERUM
Authors: Shulman N. Raphael
Published: June 2004

Increases in serum proteolytic inhibition with disease were found to be specific either for plasmin or for trypsin and chymotrypsin.

In normal serum, the plasmin inhibitor could be differentiated from the trypsin and chymotrypsin inhibitor by various physical and chemical means.

There was no apparent difference between the trypsin inhibitor and the chymotrypsin inhibitor in serum.

No qualitative differences were found between the inhibitors of normal sera and the inhibitors of sera showing elevated inhibition.
STUDIES ON HEMAGGLUTINATION AND HEMOLYSIS BY ESCHERICHIA COLI ANTISERA
Authors: Neter Erwin , Bertram Lee F. , Zak Dorothy A. , Murdock Miriam R. , Arbesman Carl E.
Published: June 2004

A study on hemagglutination and hemolysis by Escherichia coli O111 and O55 (rabbit) antisera and on hemagglutination and hemolysis inhibition by E. coli O111 and O55 antigens revealed the following facts.

1. Red blood cells of man, dog, rabbit, guinea pig, sheep, rat, and chicken adsorb E. coli O111 and O55 antigens and thus become specifically agglutinable by the homologous E. coli antisera.

2. The adsorption of these E. coli antigens is a function of the concentration of the antigen, the time (from 5 minutes to 2 hours) of treatment of the red blood cells with the antigen, and the concentration of the red blood cells used.

3. Red blood cells of man and sheep adsorb simultaneously both antigens, as indicated by the fact that both antisera give agglutination of all red blood cells. Complete agglutination does not occur when a mixture of red blood cells treated separately with the two antigens is added to one or the other of the two antisera.

4. Treatment of red blood cells of man with one of the antigens does not block the adsorption of the second antigen. Human cells treated with either or both antigens are still agglutinated by the homologous blood group (A, B, and Rh)-specific antibodies.

5. In the presence of guinea pig complement, E. coli O111 and O55 antisera produce hemolysis of modified human red blood cells in titers of the same order of magnitude as those giving hemagglutination and bacterial agglutination. The same antisera produce hemolysis of sheep cells treated with the identical antigens in titers exceeding by far those giving agglutination of modified human or sheep red blood cells.

6. Both sediment and supernate of a boiled E. coli suspension are capable of modifying red blood cells for E. coli hemagglutination; in contrast, the supernate obtained from an unboiled suspension and then heated does not modify red blood cells for hemagglutination, although it contains the antigen which can specifically adsorb E. coli antibodies, as shown by means of the hemagglutination and hemolysis inhibition tests.

7. Both the unheated and the boiled suspensions of E. coli O111 and O55 inhibit hemagglutination and hemolysis specifically.

8. Rabbit red blood cells modified by either E. coli O111 or 055 antigens, upon intravenous injection into rabbits, engender specific E. coli antibodies.

The significance of the results is discussed.
THE EFFECTS OF CHOLESTEROL DOSAGE, CORTISONE, AND DCA ON TOTAL SERUM CHOLESTEROL, LIPOPROTEINS, AND ATHEROSCLEROSIS IN THE RABBIT
Authors: Cook Donald L. , Ray Roger , Davisson Edwin , Feldstein Lois M. , Calvin Lyle D. , Green D. M.
Published: June 2004

The effects of cholesterol dosage, cortisone, and desoxycorticosterone acetate on total serum cholesterol, lipoproteins, and atherosclerosis were studied over a period of 112 days in thirty-two rabbits. Cholesterol was administered by feeding the rabbits diets containing 0.063, 0.25, and 1.0 per cent cholesterol At intervals measurements were made of total serum cholesterol and of low density lipid and lipoprotein components of three classes, Sf, 5–9, Sf 10–15, and Sf 16–30.

All three classes of lipoproteins increased with cholesterol feeding. The total serum cholesterol concentration was linearly related to both the quantity of cholesterol consumed and its concentration in the diet. Lipoprotein and total serum cholesterol concentrations were significantly and equally well correlated with the severity of atherosclerosis.

Cortisone administration in the normal rabbit increased the concentrations of total cholesterol and of lipoprotein components of the Sf 10–15 and Sf 16–30 classes, but did not produce atherosclerosis. Cortisone treatment in cholesterol-fed rabbits did not significantly affect the levels of serum lipoproteins, cholesterol concentration, or atherosclerosis produced by a 1.0 per cent cholesterol diet alone.

Values for total cholesterol and Sf 5–9 class of lipoproteins in DCA-treated animals were lower than those in controls but the degree of atherosclerosis was not significantly less.
PREPARATION AND PROPERTIES OF TYPE-SPECIFIC M ANTIGEN ISOLATED FROM A GROUP A, TYPE 1 HEMOLYTIC STREPTOCOCCUS
Authors: Lancefield Rebecca C. , Perlmann Gertrude E.
Published: June 2004

Type-specific M antigen was extracted by heating type 1 group A streptococci at pH 2 in a boiling water bath. The protein was then purified by digestion with a preparation of crystalline ribonuclease which was free of proteolytic activity. It was further purified by fractional precipitation with (NH4)2SO4.

Elementary chemical analysis of the preparation thus obtained showed an absence of phosphorus and a sulfur content of 2.46 per cent. In the ultraviolet the maximum absorption was at a wave length of 276 mµ and the minimum at 255 mµ.

In electrophoresis experiments the preparation showed a single peak in the pH range of 3 to 9, but considerable boundary spreading was observed. The type 1 M antigen was isoelectric at pH 5.3 in sodium acetate buffer of ionic strength 0.1.

The serological reactivity of the protein isolated was typical of type 1 M antigen. This protein induced the formation in rabbits of type-specific precipitins and protective antibodies. The absorption of type 1 antibacterial serum with the purified M antigen removed both the protective antibodies and the type-specific precipitins from the serum.
THE FORMATION OF COLLAGEN FIBERS BY THE ACTION OF HEPARIN ON SOLUBLE COLLAGEN: AN ELECTRON MICROSCOPE STUDY
Authors: Morrione Thomas G.
Published: June 2004

Collagen fibers have been formed in vitro by the action of heparm on solutions of collagen.

Heparin was found to be effective in inducing collagen fiber formation when present in concentrations as low as 1–80,000.

It is postulated that mast cells, by virtue of the heparin which they produce, may play a role in the formation of collagen.
THE INFLUENCE OF DIET ON IRON ABSORPTION
Authors: Hegsted D. Mark , Finch Clement A. , Kinney Thomas D.
Published: June 2004

The response of rats, chicks, mice, and guinea pigs to two diets containing various amounts of iron has been compared. With diets composed chiefly of corn grits animals of all these species absorb and store considerably more iron than those with normal diets of the same iron content. If sufficient iron is added to a normal diet, all species will absorb large amounts of iron. However, there appear to be great species differences in the level of iron which must be fed to cause the increase in absorption. Chicks and mice appear to have less effective control over iron absorption on high iron diets. Attention is called to large individual differences in ability to control iron absorption under the conditions of these experiments.
THE MULTIPLICATION OF TUBERCLE BACILLI WITHIN NORMAL PHAGOCYTES IN TISSUE CULTURE
Authors: Suter Emanuel
Published: June 2004

A technique has been described for the cultivation in vitro of normal mononuclear cells on glass slides in a liquid medium. Under these conditions the monocytes transformed into macrophages which proliferated as in ordinary tissue culture.

These cultures of monocytes could be infected with tubercle bacilli. The numbers of stainable tubercle bacilli within the monocytes increased steadily in cultures infected with virulent or attenuated strains. Evidence is given to support the view that this increase in numbers of bacilli was due to intracellular multiplication. There was no evidence of intracellular bacillary multiplication in cultures infected with an avirulent strain.

Tubercle bacilli multiplying within phagocytes in vitro exert a damaging effect upon the host cells. The damage was most obvious in cells infected with a virulent strain.

Tubercle bacilli within phagocytes were protected against the bacteriostatic effect of streptomycin added in a concentration of 5 γ per ml. of culture medium. This permitted the use of streptomycin in infected cultures to prevent extracellular multiplication of the bacilli.
GROWTH REQUIREMENTS OF DYSGONIC AND EUGONIC STRAINS OF MYCOBACTERIUM TUBERCULOSIS VAR. BOVIS
Authors: Schaefer Werner B.
Published: June 2004

The nutritional requirements of dysgonic and eugonic bovine tubercle bacilli were investigated in liquid Tween-albumin medium. The following conclusions were reached:—

Dysgonic bovine tubercle bacilli require for multiplication long chain fatty acids which can be supplied as oleic, palmitic, or stearic acid whereas eugonic bovine strains can grow in the absence of fatty acid and can utilize glucose as a sufficient source of carbon.

In the presence of fatty acids, the growth of dysgonic strains is increased by the addition of small amounts of glucose or glycerol, whereas large amounts of glucose or glycerol decrease the total growth and inhibit or retard the growth of small inocula.

In glucose-fatty acid media, the growth of dysgonic strains is further stimulated by the addition of sodium glutamate, succinate, malate, or acetate.

Sodium pyruvate enables dysgonic strains to grow rapidly in liquid media containing glucose or glycerol even in the absence of fatty acid.

The significance of these findings for the mechanism of the variation from "dysgonic" to "eugonic" is discussed.

The use of oleic acid-albumin agar without glucose permits the rapid isolation of bovine tubercle bacilli from natural sources.
THE RELATIVE EFFECTS OF PROTEIN, CHOLINE, AND METHIONINE IN THE TREATMENT OF EXPERIMENTAL DIETARY CIRRHOSIS IN THE RAT
Authors: Plough Irvin C. , Patek Arthur J. , Bevans Margaret
Published: June 2004

Cirrhosis of the liver was produced in rats by feeding a diet low in protein (4 per cent casein) and deficient in lipotropic factors. The degree of liver cirrhosis was determined from specimens obtained at biopsy. Comparable groups of animals then were treated with diets containing 4 per cent casein and 30 per cent casein. The 4 per cent casein diets were supplemented with choline and methionine; the 30 per cent casein diets were fed with and without added choline.

On supplementing the low protein diet with choline and methionine the animals remained feeble, their growth remained stunted, and their livers showed signs of progressive cirrhosis. In contrast, animals fed the higher protein diet (with or without added choline) grew normally, and their livers showed signs indicating arrest and regression of the disease process.

These studies suggest that the feeding of high protein (30 per cent casein) diets to rats with nutritional cirrhosis produces reparative effects greater than those attributable to the supplements choline and methionine.
PLASMA PROTEIN LABELED WITH LYSINE-ϵ-C14
Authors: Yuile C. L. , O'Dea A. E. , Lucas F. V. , Whipple G. H.
Published: June 2004

The metabolism of homologous plasma proteins, labeled with lysine-ϵ-C14, after oral administration to dogs has been investigated.

The speed of the various processes involved is indicated by the maximum rate of C14 O2 excretion which is attained within 1 to 4 hours, the prompt appearance of protein activity in the plasma and disappearance of non-protein activity from it, both virtually complete in 7 to 10 hours, as well as the rapid incorporation of a large percentage of the fed-C14 into tissues.

There are no essential differences between the behavior of labeled plasma and that of an amino acid digest containing ϵ-C14 labeled lysine when these two materials are given orally.

At the end of 48 hours after labeled plasma feeding, a CO2 elimination of 16 to 28 per cent of the fed C14 is noted. In contrast, after 48 hours following labeled plasma by vein, a CO2 elimination of only 2.5 per cent is recorded—almost a 10 to 1 ratio. We believe this, together with the data concerning plasma and tissue protein activity, represents a significant difference in the metabolic process. The evidence favors a complete breakdown of plasma protein to the amino acid level when given orally but not when given by vein.
METHODS FOR FOLLOWING THE FATE OF INFECTIOUS AGENTS FED TO SINGLE FLIES
Authors: Penner Lawrence R. , Melnick Joseph L.
Published: June 2004

Methods have been devised which facilitate the handling, feeding, and collection of excreta from individual flies bred in the laboratory. Using these methods, quantitative studies can be carried out in which known amounts of infectious material are fed to flies and the fate of these agents determined. It has been possible to determine the persistence of excretion of viruses, and the amount of the ingested virus recovered in the excreta and in the bodies of the flies as well.
THE HALF-LIFE OF HOMOLOGOUS GAMMA GLOBULIN (ANTIBODY) IN SEVERAL SPECIES
Authors: Dixon Frank J. , Talmage David W. , Maurer Paul H. , Deichmiller Maria
Published: June 2004

1. The half-lives of homologous gamma globulins labelled with I131 agree well with the half-lives of passively administered homologous antibodies and provide a simple, quantitative tool for the determination of antibody half-life when immunochemical techniques are difficult to apply.

2. The half-lives of gamma globulin or antibody vary markedly from species to species and apparently even among age groups within a species.

3. The half-lives of gamma globulin or antibody seem to be dependent, at least in part, on the metabolic rate of the host.
STUDIES BY ELECTRON MICROSCOPY OF THIN SECTIONS OF INFECTIOUS MYXOMATOSIS IN RABBITS
Authors: Epstein B. , Reissig Magdalena , De Robertis E.
Published: June 2004

Rabbits were inoculated with the C.P.M. strain of myxoma virus and the resulting subcutaneous tumors were fixed, embedded, and sectioned for observation with the electron microscope.

Both round cells and the typical stellate myxomatous cells were observed in addition to changes in the collagen pattern at the intercellular spaces. The cytoplasm of the cells showed a great number of bodies of varying size and density, the largest of them having the size and other characteristics of the elementary bodies of the virus. Some of the bodies showed an internal structure, being formed by the tight clumping of small dense particles.

Distribution curves of the diameter of the elementary bodies and of the smaller internal particles are presented.

The morphological problems involved in the virus-host cell relationship are discussed in the case of the myxoma virus.
STUDIES ON THE PROPAGATION IN VITRO OF POLIOMYELITIS VIRUSES
Authors: Syverton Jerome T. , Scherer William F.
Published: June 2004

Poliomyelitis virus was propagated in vitro successfully in extraneural tissues. Suspended tissue fragment cultures and combined plasma clot-suspended tissue fragment cultures of monkey or human testicular tissues were employed. Five strains representative of poliomyelitis virus were maintained for from 36 to 263 days in the suspended tissue fragment type of culture. The dilution factors calculated by tissue replacements for the eight serial passages ranged from 107.8 to 1044.5 and when assessed by fluid replacements, from 1015 to 1095.3. The LD50 for each strain of Type 2 virus was determined for selected transfers. The identify of each strain of virus was established by neutralization tests and histopathological findings in monkeys dead from the injection of tissue culture virus. Control experiments and other tests made known that propagation of poliomyelitis virus did not occur in the absence of viable testicular cells and that an extraneous virus was not inadvertently acquired during the course of these studies.
STUDIES ON THE PROPAGATION IN VITRO OF POLIOMYELITIS VIRUSES
Authors: Scherer William F. , Syverton Jerome T.
Published: June 2004

Cells like fibroblasts, having no resemblance whatever to nerve cells were obtained in morphologically pure cultures from monkey testicular tissue and were found to support the growth in vitro of poliomyelitis virus, Type 2, Yale-SK strain. Moreover, these cells were destroyed as a result of the multiplication of this virus within them. Similarly, "fibroblasts" propagated in primary explant cultures of testicle were destroyed by poliomyelitis viruses, Types 1 and 2. Type specific antibodies neutralized the pathogenic effect of poliomyelitis virus on monkey testicular fibroblasts.
THE CHEMICAL AND ANTIVIRAL PROPERTIES OF THE SOMATIC ANTIGEN OF PHASE II SHIGELLA SONNEI
Authors: Jesaitis Margeris A. , Goebel Walther F.
Published: June 2004

1. The somatic antigen of Phase II Shigella sonnei can be isolated by extracting phenol-killed microorganisms with water. This substance inactivates all T phages to which this bacillus is susceptible.

2. The Phase II antigen is constituted from a protein and a phosphorylated lipocarbohydrate. The major portion of the protein component can be removed by digestion with pancreatin. The enzymatically degraded antigen thus obtained can be further dissociated into its protein and lipocarbohydrate components by treatment with 90 per cent phenol. Glucose, galactose, glucosamine, and an aldoheptose have been identified as the monosaccharide constituents of the lipocarbohydrate.
THE USE OF PHOSPHORUS 32 IN STUDIES ON PLASMODIUM GALLINACEUM
Authors: Clarke Delphine H.
Published: June 2004

A quantitative method for following parasite growth in vitro is described. The method is based on the determination of the degree of incorporation of phosphorus into the nucleic acids, in particular desoxypentose nucleic acids, of the parasitized cell. Phosphorus incorporation is measured by utilizing the radioactive isotope, P32.

The degree of phosphorus incorporation into DNA was found to be closely correlated with estimates of parasite growth based on stained film examinations of intact cell preparations. The isotope was likewise found to be incorporated into the DNA of preparations in which the host cell had been disrupted by lysis and the extent of this incorporation also paralleled the impressions gained from smear examinations.

It is suggested that this method provides a sensitive and objective method of studying parasite growth.
TRANSAMINATION IN THE METABOLISM OF ß-2-THIENYL-DL-ALANINE IN NORMAL AND NEOPLASTIC CELLS IN VITRO
Authors: Jacquez John A. , Barclay Ralph K. , Stock C. Chester
Published: June 2004

In tissue cultures of C-57 black mouse heart and sarcoma T-241, ß-2-thienyl-DL-alanine acts specifically as a phenylalanine antagonist.

Heart cultures can transaminate between ß-2-thienyl-DL-alanine and phenylpyruvate to form L-phenylalanine and thus block the toxic action of the remaining ß-2-thienyl-DL-alanine, whereas sarcoma T-241 cultures cannot.

Of eleven mouse tumors and four rat tumors tested for their ability to perform this reaction, nine tumors had little or no activity.

The ß-2-thienylpyruvic acid resulting from transamination further reacts to form a red compound the exact structure of which is not yet known.
EFFECT OF SODIUM MONOFLUOROACETATE ON THE MULTIPLICATION OF INFLUENZA VIRUSES, MUMPS VIRUS, AND PNEUMONIA VIRUS OF MICE (PVM)
Authors: Mogabgab William J. , Horsfall Frank L.
Published: June 2004

Sodium fluoroacetate, given after virus inoculation in doses of 3 to 4 mg. per kg. in mice or 2 mg. in chick embryos, caused only a slight delay in the multiplication of the PR8 strain of influenza A virus in the mouse lung and of PR8 or the Lee strain of influenza B virus in the allantoic sac. The quantities of the compound used were sufficient to cause approximately 10 to 20 per cent mortality in mice and 100 per cent in chick embryos.

The use of small virus inocula did not markedly increase the effect of sodium fluoroacetate on the multiplication of PR8 or Lee in the chick embryo and maximal titers were obtained in all cases. In contrast to the findings in the chick embryo, sodium fluoroacetate caused a definite delay in the multiplication of Lee virus in the mouse lung but did not affect the final virus titer.

Sodium fluoroacetate in like amounts caused only a minimal delay in the multiplication of pneumonia virus of mice (PVM) in the mouse lung or of mumps virus in the chick embryo. With both PVM and mumps virus, maximal titers were obtained almost simultaneously in fluoroacetate and control animals. When three daily injections of the compound were given to mice infected previously with PVM, a definite diminution in the virus titer was demonstrable. However, pretreatment with three daily injections of the compound caused no alteration in the capacity of mice to support the multiplication of PVM.

From the results of these experiments, it appears that the cellular metabolic processes blocked by sodium fluoroacetate are not essential for the multiplication of influenza viruses, mumps virus, or pneumonia virus of mice (PVM).
THE LYSIS OF GROUP A HEMOLYTIC STREPTOCOCCI BY EXTRACELLULAR ENZYMES OF STREPTOMYCES ALBUS
Authors: McCarty Maclyn
Published: June 2004

The lysis of group A hemolytic streptococci by extracellular enzymes of Streptomyces albus has been studied. The most favorable material for fractionation of the lytic enzymes was obtained by surface growth on shallow layers of liquid medium containing an acid hydrolysate of casein, glucose, and salts. The results of fractionation experiments show that the potent proetolytic enzyme of Streptomyces albus is not able to lyse group A streptococci, and that the initiation of lysis is dependent upon the action of a second, non-proteolytic enzyme. The nature of the non-proteolytic enzyme has not been determined. It does not appear to be a ribonuclease or a lysozyme-like enzyme.