bluuebunny/crossref_metadata_2025 huggingface dataset:
HISTOCHEMICAL CHANGES IN LYMPHOCYTES DURING THE PRODUCTION OF ANTIBODIES IN LYMPH NODES OF RABBITS
Authors: Harris T. N. , Harris Susanna
Published: June 2004

Following the injection of various antigenic and non-antigenic materials into the foot-pads of rabbits, the draining (popliteal) lymph nodes were removed on successive days and studied histologically, chemically, and serologically. On the 2nd day after injection of antigen, nucleoli and cytoplasmic granules and crescents stained with pyronine began to appear. They were found first in somewhat altered reticulum cells, later in transitional forms, then in young lymphocytes, and finally in more mature lymphocytes. The identity of this pyronine-stained material as ribonucleic acid was demonstrated by specific digestion with protease-free ribonuclease.

The concentration of ribonucleic acid was determined in aqueous extracts of the lymph nodes. It was observed that the concentration had risen to more than twice its normal value by the 2nd to 5th day following the injection of antigens into the foot, and then it declined. The peak of this change occurred at or slightly before the appearance of the maximal concentration of antibodies in the same node.

Non-antigenic materials, when injected into the foot, did not give rise to an increase in the ribonucleic acid content of the lymph node.

The concentration of desoxyribonucleic acid was constant in all lymph nodes, within the limits of experimental variation.
CANINE HEMOPHILIA
Authors: Graham John B. , Buckwalter Joseph A. , Hartley L. J. , Brinkhous Kenneth M.
Published: June 2004

A study was made of the clotting defect and the course of the malady in a group of male dogs with an inherited, sex-linked bleeding disease. The clotting defect is characterized by a prolonged clotting time and a delayed prothrombin utilization, and is corrected by the addition either of thromboplastin or of normal plasma. A plasma protein fraction, fraction I, also corrects the defect. The defect appears to be due to a deficiency of a plasma factor, which normally, in the presence of platelets, makes thromboplastin available in shed blood. The clotting anomaly appears to be identical with that found in human hemophilia.

The hemostatic defect is characterized by repeated hemorrhages, usually without obvious relationship to trauma. Hemarthroses occur frequently and may result in permanent joint deformity. The animals usually die early in life from massive hemorrhage.

Transfusions with normal blood or plasma correct the clotting defect and readily control the hemorrhagic phenomena. By the use of transfusions, these dogs have been reared to maturity.
A RESISTANT VARIANT OF MUMPS VIRUS
Authors: Ginsberg Harold S. , Horsfall Frank L.
Published: June 2004

Serial passage of mumps virus in the presence of inhibitory quantities of the capsular polysaccharide of Friediänder bacillus type B results in the appearance of a variant strain of the virus. Multiplication of the variant virus is not inhibited by the polysaccharide. A similar resistant variant is obtained with polysaccharide in a single cycle of multiplication when very large inocula of mumps virus are employed. The resistant variant is indistinguishable from the parent strain as to infectivity, reactivity with erythrocytes, and immunological properties, but appears to have a somewhat slower rate of multiplication. Serial passage of the resistant variant in the absence of polysaccharide results in the reappearance of a sensitive strain. It is suggested that mumps virus populations are inhomogeneous; that naturally occurring variants are present in such populations and possess distinctive properties; that the use of a chemical inhibitor of mumps virus multiplication makes possible the selection of a variant possessing a predictable property. The findings are discussed in relation to the mechanism of inhibition of mumps virus multiplication by polysaccharide.
PROTEIN METABOLISM AND EXCHANGE AS INFLUENCED BY CONSTRICTION OF THE VENA CAVA
Authors: McKee Frank W. , Hyatt Robert E. , Wilt William G. , Tishkoff Garson H. , Whipple George H.
Published: June 2004

Further studies of ascitic fluid production and related factors in dogs with constriction of the vena cava above the diaphragm are reported.

Whole dog plasma given intravenously to such animals produces a rise in circulating plasma protein to normal levels, but increases the output of ascitic fluid with a loss of protein via the ascites equivalent to 72, 76, and 65 per cent respectively, of the injected protein.

Forced ingestion of water in excess of the test animal's normal needs and desires produces no significant changes in the circulating plasma protein level or in ascitic fluid production.

Amino acid growth mixtures given intravenously in distilled water cause weight loss, elevation of circulating plasma proteins, a slightly negative nitrogen balance, but no ascitic fluid production.

Amino acid growth mixtures given intravenously in normal saline cause depression of the circulating plasma proteins, negative nitrogen balance, and significant ascitic fluid production.

Ascitic fluid given intravenously to the test animals causes a marked depression of circulating plasma proteins, a marked increase in ascitic fluid production containing the equivalent of 116 and 98 per cent of the injected protein, and a negative nitrogen balance.

Ascitic fluid given orally produces a marked depression of circulating plasma proteins, and a marked increase in ascitic fluid secretion, containing the equivalent of 66, 66, and 54 per cent respectively, of the ingested protein.

Sodium chloride is a dominant factor in some of these experiments where abundant ascites production is recorded. Protein levels and intake are important, but take second place to sodium.

Ascitic fluids show electrophoretic patterns which are almost identical to the plasma patterns. The A/G ratios are often equal in ascitic fluid and plasma, sometimes even lower in the ascitic fluid. This emphasizes the ease with which globulins pass cell or other membrane barriers in these experiments.
IMMUNOCHEMICAL STUDIES ON BLOOD GROUPS
Authors: Baer Harold , Kabat Elvin A. , Knaub Vesta
Published: June 2004

Blood group substances have been isolated from the saliva of human beings of blood group B and from the linings of individual horse stomachs. The properties of the human B substances are similar to those of hog and human blood group substances previously isolated. The horse substances showed lower hexosamine and reducing sugar and higher total and non-hexosamine nitrogen than do the materials from the other species. Materials isolated from individual horse stomachs possess either A or B activity or both. Certain stomachs yielded products of identical analytical composition but with neither blood group A, B, or O activity as measured by their ability to inhibit isoagglutination. Fucose has been identified as a constituent of the horse blood group substances.
LACK OF IDENTITY IN NEUTRALIZING AND HEMAGGLUTINATION-INHIBITING ANTIBODIES AGAINST INFLUENZA VIRUSES
Authors: Walker Duard L. , Horsfall Frank L.
Published: June 2004

There is an exponential linear relationship between the quantity of influenza virus neutralized and the quantity of immune serum employed in in ovo neutralization. The slope of the neutralization line is extremely steep. The concentration of neutralizing antibody can be measured with considerable precision in ovo if the constant virus-varying serum technique is utilized.

The amounts of hemagglutination-inhibiting and neutralizing antibodies which are absorbed by a given quantity of influenza virus (PR8) were found to be predictable and the degree of reactivity of these two antibodies was shown to be directly related to the extent of immunization. It was demonstrated that there are marked discrepancies in correlation between antibody titers obtained by in vitro hemagglutination-inhibition and in vivo neutralization techniques and that neutralizing antibody is preferentially absorbed by a given quantity of virus. Inasmuch as the results were found not to be attributable to peculiarities of the techniques employed, it appears that the antibodies measured by hemagglutination-inhibition in vitro and by neutralization in vivo are not identical.
THE CIRCULATION OF ASCITIC FLUID
Authors: McKee Frank W. , Wilt William G. , Hyatt Robert E. , Whipple George H.
Published: June 2004

After plasma containing labeled plasma protein has been given intraperitoneally to dogs with experimental ascites a steady and rather rapid movement takes place of the labeled protein into the circulating blood.

When plasma containing labeled plasma protein has been injected intravenously into the ascitic dog the labeled protein steadily disappears from the circulating blood and appears promptly and steadily in the ascitic fluid.

The period of complete exchange or turnover in either instance is measured in days (2 to 7), but many factors enter in and make for variation.

Lysine labeled with radio carbon is incorporated into the plasma proteins by feeding the donor dog.

These experiments emphasize the ready exchange of proteins in the plasma with those in the ascitic pool and vice versa. This exchange may be termed circulation of ascitic protein.
STUDIES ON THE VIRULENCE OF TUBERCLE BACILLI
Authors: Bloch Hubert
Published: June 2004

The bacillary cords characteristic for virulent tubercle bacilli are readily disrupted when wet bacilli are suspended in hydrocarbons such as paraffin oil or petroleum ether.

The disruption of cords is due to the removal of a material coating the surface of the bacilli and causing them to adhere to each other.

This material can be obtained from virulent bacilli by extracting them with petroleum ether. It is a lipid. Avirulent variants of tubercle bacilli do not yield a similar material after extraction in the same manner; only little of it is obtained from BCG bacilli.

The following properties of the fraction obtained by petroleum ether extraction are described:

(a) It inhibits the migration of leukocytes in vitro.

(b) If repeatedly injected in small doses into mice, it is toxic, whereas a single high dose does not give rise to toxic manifestations.

(c) The susceptibility of mice to the toxic action of repeated injections parallels to some extent their degree of susceptibility to infection with the strain of tubercle bacilli from which the fraction was obtained.

(d) The injection of the extracted material into guinea pigs does not induce a state of allergic reactivity toward tuberculin.

Likewise, tuberculin-positive guinea pigs do not show hypersensitivity against injections of the extracted substance.

Bacilli extracted with petroleum ether do not lose their viability. They grow out normally in vitro, and they are still pathogenic. However, the removal of the petroleum ether-soluble lipid from the bacilli results in a loss of the ability of the organisms to inhibit the migration of polymorphonuclear leukocytes. Moreover, mice and guinea pigs infected with extracted bacilli may develop tuberculosis considerably slower than animals injected with comparable amounts of unextracted organisms.

The significance of these findings is discussed in relation to the problem of the virulence of tubercle bacilli.
DETERMINATION OF DIFFERENCES IN VIRULENCE OF STRAINS OF SALMONELLA TYPHOSA
Authors: Batson H. C. , Landy Maurice , Brown Martha
Published: June 2004

An investigation is reported of a comparison by three methods of the degree and certainty of differentiation of strains of S. typhosa of different virulence for mice. These methods were (a) intracerebral injection, (b) intraperitoneal injection of saline suspensions, and (c) intraperitoneal injection of mucin suspensions of the test organisms.

With the strains of S. typhosa employed, differentiation was questionable by the intracerebral method, somewhat more marked by the intraperitoneal-saline suspension method, and most definite by the intraperitoneal-mucin suspension method.

Differentiation of the strains employed was found to be independent of the presence or absence of Vi antigen and apparently was more dependent upon the method of testing than upon any known differences in biological characteristics of the organisms.
PRODUCTION OF BCG VACCINE IN A LIQUID MEDIUM CONTAINING TWEEN 80 AND A SOLUBLE FRACTION OF HEATED HUMAN SERUM
Authors: Fenner Frank , Dubos René J.
Published: June 2004

Groups of guinea pigs were vaccinated by the intracutaneous route with cultures of BCG grown in a liquid medium containing Tween 80 and the soluble fraction of heated human serum. After the cultures had been stored at 4°C. for various periods of time, the antigenic response was compared with that of another group of guinea pigs receiving standard BCG vaccine prepared by the conventional technique.

The local lesions occurring at the site of injection of cultures in Tween-serum filtrate medium were more severe than those produced by the standard vaccine. It was shown that this difference was probably due to the much larger number of viable bacilli in the former preparations. A marked degree of sensitization could be produced with culture dilutions containing as few as 10 viable units (single bacilli or small clumps). Slightly larger doses of BCG led to the highest degree of tuberculin allergy detectable by the technique employed. Further increases in the dose of vaccine failed to alter the level of sensibility when the animals were tested with tuberculin 5 weeks after vaccination.

The same degree of sensitization was achieved by vaccination with 0.1 cc. of either the standard vaccine or any of the fresh or stored cultures in Tween-serum filtrate medium. It was shown that these doses contained numbers of living bacilli far greater than the minimal number required to induce maximal sensitization.

Under the conditions used, the guinea pigs vaccinated with cultures of BCG (fresh or stored) grown in the Tween-serum filtrate medium exhibited a marked degree of resistance to subcutaneous infection with virulent tubercle bacilli.
INFLUENZA
Authors: Pinkerton Henry , Greiff Donald , Blumenthal Herman T. , Hensley Richard
Published: June 2004

In addition to the cycles of growth shown by the influenza A virus during the first 24 hours of its residence in the fertile egg, cycles separated by longer time intervals have been noted between the 24th and 96th hours. These longer cycles are best seen when the eggs are incubated at 40°C.

Corresponding fairly accurately with these cycles of growth of the virus, wide cyclic variations in the rates of increase in oxygen consumption of the infected eggs have been found to occur. These variations are in striking contrast to the uniformity of increase noted in uninfected eggs.

The variations in infectivity may be caused by periodic interference with virus multiplication by accumulated inactive virus particles. The variations in oxygen consumption probably are correlated with variations in the concentration of virus toxins.
IMPROVED METHODS FOR THE PREPARATION OF THE SPECIFIC POLYSACCHARIDES OF PNEUMOCOCCUS
Authors: Heidelberger Michael , MacLeod Colin M. , Markowitz Harold , Roe Amy S.
Published: June 2004

The specific polysaccharides of Types I and V pneumococcus give sharp equivalence zones and show maximal precipitation with homologous rabbit antisera only when carefully prepared from cultures which have not been neutralized with alkali.

The precipitating power of S V toward homologous rabbit antiserum falls off in 0.1 N NaOH even more rapidly than that of S I, dropping to 7 per cent of the original value in 6 days at room temperature. The alkaline solution develops a large absorption peak at 270 mµ.

Directions are given for the preparation of S VII and S XII.
THE EFFECT OF TUBERCLE BACILLI ON THE POLYMORPHONUCLEAR LEUCOCYTES OF NORMAL ANIMALS
Authors: Martin Samuel P. , Pierce Cynthia H. , Middlebrook Gardner , Dubos René J.
Published: June 2004

A description is given of a slide cell whereby the rate of migration of very small amounts of leucocytes can be followed and measured.

The migration of polymorphonuclear leucocytes was found to be inhibited by virulent tubercle bacilli pathogenic for the class of animal (mammal or bird) from which the leucocytes were obtained; it was not affected by the avirulent variants of these microorganisms, or by bacilli pathogenic for animals of the other class.

Tests failed to disclose that the inhibition of leucocytic migration resulted from any gross damage caused by the bacilli to the leucocytes.
RECIPROCAL CHANGES IN PLASMA PROTEIN AND PLASMA ACACIA AS RESULT OF HIGH AND LOW PROTEIN DIETS
Authors: Knutti R. E. , Goetsch J. B. , Warrick R. A.
Published: June 2004

Dogs were made hypoproteinemic by repeated injections of gum acacia, and the acacia injections were discontinued. Diets of varying protein content were then given. When a high protein diet is provided the plasma protein concentration increases; with a low protein diet, or under conditions of fasting, the plasma protein concentration diminishes. Similarly, plasma acacia concentration shows increases and decreases which are reciprocal to the protein variations. Total circulating plasma protein and total circulating plasma acacia show similar changes. In all instances total circulating colloid (acacia plus protein) concentration adds up to an amount within normal limits for protein alone.

The results indicate that under these conditions, acacia stored in the body (principally in the liver) can be removed from its site of deposit and returned to the blood.

The data also show that dogs in which acacia is deposited in large quantities, require a larger amount of protein in the diet to maintain a constant plasma protein content than do normal dogs.

It appears that the mechanism for maintenance of peripheral colloidal material may be dependent on differences in intracellular and extracellular colloidal osmotic pressure. The experiments also support the idea that plasma protein molecules, as well as gum acacia, may pass in and out of cells through the cell membranes.
STUDIES ON HERPETIC INFECTION IN MICE
Authors: Evans Charles A. , Slavin Howard B. , Berry George Packer
Published: June 2004

1. The severity of herpetic infection, of mice varied according to the site of inoculation, decreasing in the following order: cornea, skin of abdomen, pad of hind foot, tail.

2. The preliminary treatment of the foot pad or tail with methylcholanthrene increased the susceptibility to herpetic infection to a limited extent.

3. Two-week-old mice showed a much greater susceptibility to herpes virus inoculated on the tail or on the pad of the hind foot than did adult mice.

4. The HF strain of herpes virus, after more than 125 serial brain-to-brain passages in mice, possessed high virulence for cutaneous tissues of mice and showed no important differences in this respect from a recently isolated strain (Klee) of herpes virus.
STUDIES ON ENTRY AND EGRESS OF POLIOMYELITIS INFECTION
Authors: Faber Harold K. , Silverberg Rosalie J. , Dong Luther
Published: June 2004

Direct exposure to poliomyelitis virus of the central end of a cut branch of the V cranial nerve was followed by centripetal spread of infection to the semilunar (Gasserian) ganglion, involvement of which was detected both histologically and by subinoculation as early as the 3rd day. In some instances infection did not progress further; in others it spread into the CNS with initial involvement of the trigeminal centers in the pons and medulla as early as the 4th day and by the 5th day was further advanced but still limited to the brainstem. Once infection was established it progressed both rostrally and caudally, at times with great rapidity, through the brainstem and reached the cord on the 6th or a later day. Incidental exposure in traumatized muscle of peripheral fibers of the VII motor nerve led in some instances to spread along that pathway directly into the CNS.

Application of the experimental results to human poliomyelitis is of interest chiefly in four respects. (1) The ascent of infection from a peripheral ganglion of the head area to the CNS with initial encephalitis of the brainstem and subsequent descent to the spinal cord is believed to parallel the evolution of the human disease as suggested by the character and order of development of the early symptoms and signs. (2) The failure in some instances of infection to spread from an infected peripheral ganglion to the CNS may parallel inapparent ("subclinical") poliomyelitis in man. (3) Invasion of virus through traumatized muscle directly to the CNS also has possible analogues in human experience which will be discussed in a later paper. (4) The presence of well marked and sometimes extensive lesions in the brainstem one or more days before symptoms emerge is also believed to parallel the human case.
THE EFFECT OF PODOPHYLLOTOXIN, COLCHICINE, URETHANE, AND NITROGEN MUSTARD ON THE RESPIRATION OF NORMAL AND SUPRARENALECTOMIZED RAT LYMPHATIC TISSUE
Authors: Miller Zelma Baker , Davison Clarke , Smith Paul K.
Published: June 2004

The injection of podophyllotoxin, colchicine, and a nitrogen mustard derivative, methyl-bis(ß-chloroethyl)amine, into normal animals causes a reduction of the respiration of the lymphatic tissues, spleen, and/or thymus. No effect was demonstrable on kidney, a representative tissue of non-lymphatic origin.

The degree of inhibition was considerably less in suprarenalectomized animals, suggesting that the inhibition is mediated by the suprarenal gland.
STABILIZATION OF STREPTOLYSIN S BY POTASSIUM IONS
Authors: Bernheimer Alan W.
Published: June 2004

Potassium ions, and to a less extent, ammonium, magnesium, and barium ions, protect streptolysin S against thermal inactivation.
ACUTE DISSEMINATED ENCEPHALOMYELITIS FOLLOWING IMMUNIZATION WITH HOMOLOGOUS BRAIN EXTRACTS
Authors: Thomas Lewis , Paterson Philip Y. , Smithwick Betty
Published: June 2004

1. A severe demyelinating condition characterized by ataxia and paralysis, in some instances leading to death, was produced in thirty-five of a total of fifty-five dogs following immunization with homologous brain tissue combined with Freund's adjuvants. In more than 30 per cent of instances paralysis did not occur until immunization was continued for 6 or more months. Only eight dogs became paralyzed after a single injection of antigen. The condition appeared between 6 and 15 days after the last injection in all animals, irrespective of the total number of injections or the duration of immunization.

2. An antibody which reacted in complement fixation tests with aqueous and alcoholic extracts of homologous brain tissue was demonstrable in the majority of immunized dogs, whether or not the animals became paralyzed. It appeared during or after the 3rd week of immunization, and its occurrence or titer could not be correlated with the incidence of the encephalomyelitis. In general, there were fewer dogs with demonstrable antibody in the paralyzed group than in the non-paralyzed group.

3. A flocculation reaction with alcohol extracts of homologous brain was demonstrated in the serum of immunized dogs. The antigen and antibody involved were apparently identical with those responsible for the complement fixation reactions.

4. The brain tissue component which reacted as antigen in the complement fixation test was present in adult brain from several mammalian species, and peripheral nerve. It was not present in the brain of newborn dogs nor in other unrelated organs. It was demonstrable in brain tissue which had been allowed to autolyze, or treated with 10 per cent formalin. It was not impaired by boiling, or by acid hydrolysis, and was contained in the unsaponifiable fraction of brain lipids. It was separable from cholesterol by digitonin precipitation of the latter.

5. Immunization of dogs with the unsaponifiable fraction of homologous brain, in adjuvants, caused the appearance of antibrain antibody similar to that in animals injected with whole brain. Encephalomyelitis was not observed during a 2 month period of immunization with this fraction.

6. In guinea pigs, an injection of the unsaponifiable fraction of brain, in adjuvants, was followed by fatal meningoencephalitis, but the identity of the state with that caused by whole brain antigens was not established.
A VIRAL AGENT ISOLATED FROM A CASE OF "NON-PARALYTIC POLIOMYELITIS" AND PATHOGENIC FOR SUCKLING MICE: ITS POSSIBLE RELATION TO THE COXSACKIE GROUP OF VIRUSES
Authors: Cheever F. Sargent , Daniels Joan B. , Hersey E. Freeman
Published: June 2004

1. A viral agent, Powers, causing myocarditis, adipositis, pancreatitis, hepatitis, and encephalomyelitis but not myositis in suckling mice 1 to 2 days old has been isolated from the stool of a patient in whom the clinical diagnosis was "non-paralytic poliomyelitis."

2. Serological evidence linking the virus to the clinical disease observed was clear only in the case of "non-paralytic poliomyelitis" from which it was isolated.

3. The possible relation of this agent to the Coxsackie group of viruses is discussed. No serological relationship with the Connecticut 5, Ohio R, and High Point strains was demonstrated.

4. A second virus, Matulaitis, has been isolated from a concurrent case of "non-paralytic poliomyelitis" in the same area. Lesions produced in infant mice by the two agents show certain differences.
THE CRYSTALLIZATION AND SEROLOGICAL DIFFERENTIATION OF A STREPTOCOCCAL PROTEINASE AND ITS PRECURSOR
Authors: Elliott S. D.
Published: June 2004

Grown in dialysate broth at a pH between 5.5 and 6.5, some strains of group A streptococci elaborate the precursor of a proteolytic enzyme. Within this range of hydrogen concentration the precursor is also produced when the streptococci are suspended in a peptone dialysate containing glucose and incubated at 37°C. The precursor does not appear to be produced at a neutral or alkaline reaction.

Methods are described whereby the precursor and proteinase have been isolated in crystalline form. The precursor crystallizes from half-saturated ammonium sulfate at pH 8.0 and a temperature of 22°C. or higher; the proteinase crystallizes from 0.15 saturated ammonium sulfate at pH 8.0 but does so most readily at refrigerator temperature. The degree of purification achieved by these procedures is discussed.

The activity of purified preparations of the precursor and of proteinase has been tested against α-benzoyl-l-arginineamide and, with this as a substrate, the conversion of precursor to proteinase by autocatalysis or by trypsin has been confirmed.

Immunological experiments are described, the results of which provide evidence of the distinct antigenic specificity of the precursor and proteinase; the conversion of precursor to proteinase has been followed by means of serological tests.
THE EFFECT OF A DEFICIENCY OF THE B VITAMIN COMPLEX (EXCEPT THIAMINE) ON THE BLOOD PRESSURE OF THE RAT
Authors: Merritt Phyllis
Published: June 2004

Certain diets essentially identical with those previously reported as causing an elevation of the blood pressure of rats have failed to produce any elevation.

Examination of micro sections from the kidneys of these rats, with the aid of special stains, has failed to demonstrate any vascular lesions similar to those previously described by Calder.

Evidence of tubular atrophy was present to a minor degree in sections of the kidneys of rats fed diets deficient in the B vitamins (except thiamine) and in those fed diets low in choline. This finding has been noted previously by others, but examples of this type of lesion were found as well in animals fed the control diets of our experiments. It should be emphasized that these control diets were nutritionally inadequate.

Deposits of intracellular granules of hemosiderin were prominent in the convoluted tubules of the kidneys in rats fed the diets deficient in the B vitamin complex.
STUDIES ON PEROXIDATIVE DETOXIFICATION OF PURIFIED DIPHTHERIA TOXIN
Authors: Agner Kjell
Published: June 2004

The mechanism of the peroxidative oxidation of diphtheria toxin has been investigated. It has been found that this reaction requires the presence of an oxidizable, dialyzable cofactor in addition to hydrogen peroxide and peroxidase. Cofactors are present in a variety of materials and have been partially purified from urine.

The flocculation titer of toxin modified by peroxidation remains unchanged even after 99 per cent or more of the toxicity has been destroyed. The change thus appears analogous to the conversion of toxin to toxoid in the presence of formalin.

It is suggested that the well known conversion of crude diphtheria toxin to toxoid which occurs on storage or aging may be due to a slow peroxidative process.
PLASMA IRON AND SATURATION OF PLASMA IRON-BINDING PROTEIN IN DOGS AS RELATED TO THE GASTROINTESTINAL ABSORPTION OF RADIOIRON
Authors: Yuile Charles L. , Hayden John W. , Bush James A. , Tesluk Henry , Stewart Wellington B.
Published: June 2004

The absorption of a test amount of radioactive iron during artificial saturation of the plasma iron-binding protein, by the repeated intravenous injection of small amounts of iron, was measured in three normal and four anemic dogs.

The procedure had no detectable influence on the iron absorption of the normal dogs nor on that of two of the anemic dogs. Two other anemic dogs showed some suppression of iron absorption, though the amount absorbed was still in excess of that absorbed by a normal dog. The reasons for this suppression are not clear from these experiments.

Artificially raising the plasma iron to normal levels in one anemic dog did not influence the absorption of iron from the gastrointestinal tract nor was a delayed effect noted after the plasma iron had fallen to base line levels after 5 hours of artificial saturation.

It appears that the plasma iron-binding protein and its relative saturation play little role per se in the control of iron absorption in dogs.
EXPERIMENTAL CONGENITAL TOXOPLASMOSIS
Authors: Cowen David , Wolf Abner
Published: June 2004

Pregnant mice infected with Toxoplasma by the vaginal route have been found to transmit toxoplasmosis to the placentas and fetuses in utero. The microorganism entered the blood stream of the mother from primary foci of infection in the vaginal wall and produced disseminated lesions in the labyrinth of the allantoic placenta at the same time as other peripheral maternal tissues were involved. Placental lesions were observed in mice infected with Toxoplasma by vagina between the 3rd and the 9th day of pregnancy. They consisted of microscopic foci of degeneration, without inflammation, in the syncytial trophoblast, and parasites undergoing multiplication were readily identified in them. Here Toxoplasma gained access to the fetal circulation. Following the vaginal instillation of Toxoplasma on the 8th day of pregnancy, subinoculation of test animals revealed the parasites in the maternal peripheral and placental blood on the 13th day and later, while the first histopathologic changes in the placenta were found on the 17th day. Toxoplasma could be demonstrated in suspensions of fetal tissues on and after the 17th day by the injection of normal test animals. However, no lesions of toxoplasmosis, or Toxoplasma, were found in histologic sections of fetuses 11 to 21 days old removed at autopsy from vaginally infected mothers. It is concluded that before birth the parasites were confined to the fetal blood. The experiments provide the first direct histological demonstration of placental toxoplasmosis. The possible bearing of the experimental disease on human placental and fetal toxoplasmosis is briefly considered. It is probable that a maternal parasitemia during the latter part of pregnancy, whatever the portal of entry may be, is an essential factor in the pathogenesis of human congenital toxoplasmosis and that this occurs shortly after exposure to Toxoplasma rather than in a later chronic stage of the infection. The suggestion is offered that some instances of spontaneous abortion or fetal death in man, as in the mouse, may be due to inapparent toxoplasmosis.
EXPERIMENTAL CONGENITAL TOXOPLASMOSIS
Authors: Cowen David , Wolf Abner
Published: June 2004

A study has been made of congenital toxoplasmosis in the offspring of mice infected with Toxoplasma by the vaginal route during pregnancy. Some of the young mice were retarded in postnatal development, and some became ill or died in the 2nd to 4th weeks of life while the majority remained symptom-free in spite of the presence of toxoplasmic lesions of varying degrees of severity. Congenital toxoplasmosis developed only in offspring whose mothers had been infected on the 7th to 9th day of pregnancy. Infection of the offspring without active toxoplasmosis in the mother was not observed. The highest incidence of congenital infection (57.6 per cent) was obtained by giving 2 vaginal instillations of Toxoplasma-infected mouse brain on the 8th and 9th days of pregnancy. Mice infected before the 7th day developed placental toxoplasmosis but rarely delivered viable young. When the mother was infected after the 9th day, the offspring were normal. When congenital toxoplasmosis occurred in a litter, a majority or all of the individual offspring were usually infected. Although pathologic changes were not present in the suckling mice at birth, and did not appear before the 9th postnatal day, reasons are stated for excluding the possibility of postnatal contact or milk-borne infection. It cannot be assumed from the experimental disease that the vagina is a portal of entry of Toxoplasma in human congenital toxoplasmosis. Any route of infection leading to a maternal parasitemia during pregnancy might result in toxoplasmosis of the placenta and transmission of the disease to the offspring before birth. Unlike the restricted time interval effective in the mouse, there is a long period during the later months of pregnancy in the human being in which transplacental passage of the infection may occur. When transmission to the fetus takes place shortly before parturition, evidence of disease in the human infant, as in the mouse, may not become manifest until several weeks postpartum, and the prenatal origin of the infection may not be apparent. When the fetus becomes infected well before parturition, symptoms of congenital toxoplasmosis may be present at birth. The asymptomatic character of the infection in many of the young mice would appear to have a counterpart in certain instances of human congenital toxoplasmosis.
STUDIES ON BACTERIOPHAGE
Authors: Goebel Walther F.
Published: June 2004

By serological means it has been shown that E. coli B contains an antigen closely related to the protein-lipocarbohydrate complex of Phase II Sh. sonnei. Lysis of E. coli B by three of the T viruses, T3, T4, and T7, can be inhibited by the Phase II dysentery antigen. It has been suggested that the receptor of E. coli B with which these viruses combine is this newly described antigenic component. Two variants of the virus T3 have also been described, in stocks which have been treated with the Phase II antigen. One of these variants infects both Phase II Sh. sonnei and E. coli B, and the other infects only the latter microorganism; neither of the two variants is inhibited by concentrations of the Phase II antigen of 1 mg. per cc. The distinctive properties of the variants are not hereditary.
PRESSOR SUBSTANCES IN ARTERIAL HYPERTENSION
Authors: Olsen Norman S. , Schroeder Henry A. ,   With the Technical Assistance of Helen L. Hilderman and Edna M. Menhard
Published: June 2004

Pherentasin, a material producing a prolonged pressor response in rats, has been procured from the arterial blood of hypertensive patients and purified. Pherentasin is of small molecular size, non-protein in nature, dialyzable, soluble in water and 90 per cent ethanol, and extractable into organic solvents from alkaline solution. It contains an amino group essential to activity, which is probably primary, and also contains an active carbonyl group. It has been found in concentrations up to approximately 20 γ per liter of blood.
A COMPARISON OF THE GROWTH CURVES OF ADAPTED AND UNADAPTED LINES OF INFLUENZA VIRUS
Authors: Davenport Fred M. , Francis Thomas
Published: June 2004

A comparison of the growth curves of adapted and unadapted lines of the same strain of Type A or Type B influenza virus in mice has demonstrated that the unadapted lines of virus exhibit a lag phase of growth lasting approximately 12 hours during which little or no multiplication of virus can be demonstrated. Multiplication by the adapted line begins earlier and may be evident as soon as 6 hours after inoculation. Following the lag phase, the rates of multiplication of both lines of virus were indistinguishable when dilute inocula were used. The maximal infectious titer of the unadapted line was lower than that of the adapted line of the same strain and this disparity was increased following inoculation with large doses of virus. The shape and slope of the growth curves of influenza virus in mice were shown to be determined by the line, strain, and concentration of virus used for inoculation. The significance of these findings has been discussed.
DESOXYCORTICOSTERONE ACETATE AND WOUND HEALING
Authors: Pirani Conrad L. , Stepto Robert C. , Sutherland Kenneth
Published: June 2004

The effect of desoxycorticosterone acetate (DCA) on the granulation tissue of healing and healed linear laparotomy wounds was studied in young adult male guinea pigs maintained on a complete diet and on a known intake of ascorbic acid.

DCA induces the production of an excessive amount of granulation tissue, as evidenced by a relatively great number of fibroblasts and by a larger amount of ground substance. This effect was accompanied by a slight to moderate lag in the maturation process of both cellular and intercellular elements. These changes were observed when DCA administration was begun 5 days prior to operation, but were less obvious or absent if DCA was injected, beginning on the 5th or 10th postoperative day. The results indicate that the action of DCA on immature, proliferating connective tissue is marked, and is considerably less or absent when connective tissue elements have reached partial or almost complete maturity.

The effect of DCA on connective tissue does not appear to rest on the basis of an altered nutritional status. Chemical and histochemical studies of the adrenals suggest that the action of DCA on connective tissue is probably mediated through a disturbance of adrenocortical function, namely an imbalance between hormones of the zona glomerulosa (excess of DCA) and those of the zona fasciculata (deficiency of glucocorticoids).

The presence of changes in granulation tissue and the lack of them in mature resting connective tissue of DCA-treated guinea pigs confirm the view that a profound difference in the response mechanism exists between resting and actively proliferating connective tissue.
PATHOGENESIS OF COXSACKIE VIRUS INFECTION
Authors: Melnick Joseph L. , Godman Gabriel C.
Published: June 2004

The quantitative distribution of the Conn.-5 strain of Coxsackie virus in different tissues was determined by serial titration at intervals after inoculation of 4 to 5 day old mice. High titers were reached by the 2nd day in blood, heart, liver, muscle, intestine, and its contents, and these were maintained through the 8th day, except for the blood, in which the virus level fell earlier. In paralyzed mice, muscle and brain attained the highest titers and it was in these tissues alone that virus persisted through the 9th day of illness.

The pathology of the infection has been briefly described. In particular, the evolution of morbid changes in striated muscle was correlated with the concentrations of virus in muscle. Acute muscle necrosis first occurred when there was a peak viral concentration (4th day), and reached maximal intensity on the 8th day. Scattered acute lesions continued to appear while the virus titer remained above 10–4, from the 9th to 12th day. With the decrease in the myositis, there was a concomitant decrease in the incidence of perceptible disease. Inflammation was found to follow upon the development of necrosis, and subsided slowly. Regeneration began very early, became exuberant, and led finally to restitution of the muscle.
THE PATHOGENESIS OF INFECTION WITH A VIRULENT (CG 179) AND AN AVIRULENT (B) STRAIN OF NEWCASTLE DISEASE VIRUS IN THE CHICKEN
Authors: Karzon David T. , Bang Frederik B.
Published: June 2004

Circulating antibody appeared in the convalescing NDV-infected chicken concomitantly with the disappearance of virus from the tissues. The antigenic response to the CG 179 and B strains was demonstrated to be approximately equal.

The neutralization test in the embryo and the hemagglutination inhibition technique yielded parallel results in the measurement of antibody early in convalescence, but late in convalescence the hemagglutination inhibition titers were relatively lower. This disparity indicates the possible duality of the antibodies.

There was a wide ratio between the neutralizing antibody titers found in the brain and in the serum after an asymptomatic infection with NDV. The antibody level in the brain appeared to be related to the extent of virus growth and damage in the central nervous system.

It appeared likely that a major factor in determining the virulence of the CG 179 strain was the more rapid attainment in the central nervous system of high virus concentration which outstripped the defense mechanisms of the host.
MECHANISM OF PROTEINURIA
Authors: Lippman Richard W. , Ureen Helen J. , Oliver Jean
Published: June 2004

Intraperitoneal administration of bovine albumin sharply increases glomerular permeability to hemoglobin in the rat kidney. In addition, bovine albumin "saturates" the tubular absorption mechanism and inhibits the tubular absorption of subsequently administered hemoglobin. Egg white, ovalbumin, and ovomucoid, in contrast, do not produce significant changes in glomerular permeability to hemoglobin or in the tubular absorption of hemoglobin. These effects have been demonstrated both by physiologic measurements and by the morphologic demonstration of the absorbed proteins.
THE INFLUENCE OF INTRAVENOUSLY ADMINISTERED SURFACE-ACTIVE AGENTS ON THE DEVELOPMENT OF EXPERIMENTAL ATHEROSCLEROSIS IN RABBITS
Authors: Kellner Aaron , Correll James W. , Ladd Anthony T.
Published: June 2004

A study was made of the relationship of blood lipids to the development of experimental atherosclerosis.

Rabbits fed a diet containing cholesterol were found to develop hyperlipemia characterized by a great increase in blood cholesterol and a much lesser increase in blood phospholipids; after several weeks they manifested conspicuous atherosclerosis of the aorta, as has often been observed by others. Comparable rabbits fed the same diets containing added cholesterol were given in addition repeated intravenous injections of the surface-active agents Tween 80 and Triton A20; these animals developed hyperlipemia which was characterized by a great increase in blood cholesterol and an equivalent or even greater increase in phospholipids, and they had much less atherosclerosis than did the control rabbits fed cholesterol alone.

In further experiments it was observed that repeated intravenous injections of Tween 80 did not result in resorption of previously induced atherosclerosis in rabbits.

The findings are discussed in relation to the pathogenesis of natural and experimental atherosclerosis.
ANTIMICROBIAL AGENTS IN THE PREVENTION OF DIETARY HEPATIC INJURY (NECROSIS, CIRRHOSIS) IN RATS
Authors: György Paul , Stokes Joseph , Goldblatt Harry , Popper Hans
Published: June 2004

The effect of various antimicrobial agents, such as aureomycin, terramycin, streptomycin, chloromycetin, penicillin, polymyxin, and sulfaguanidine on the development of massive dietary necrosis of the liver in rats has been studied. Delay in the production of hepatic necrosis was obtained from aureomycin and, to a lesser extent, from terramycin and streptomycin. Indication of temporary protection was shown by sulfaguanidine, whereas chloromycetin, polymyxin, and penicillin were not protective.

B12, added alone, or in combination with aureomycin, to the basal experimental diet had no influence on the development of hepatic necrosis. A combination of pectin with streptomycin enhanced the protective effect of the antibiotic.

All the antimicrobial agents tested, without relation to their effect on hepatic necrosis, produced temporary stimulation of growth in the experimental animals.

The beneficial effect of aureomycin was not limited to the delay of hepatic necrosis but manifested itself also in the prevention of hepatic cirrhosis in rats fed a low protein (casein)-high fat diet. In contrast to control animals showing the usual combination of cirrhosis and renal changes, the rats receiving supplements of aureomycin were free of both cirrhosis and renal changes. The rats receiving aureomycin took more food in and gained weight.

No microscopic alterations were seen in the pancreas of the control rats with cirrhosis.

In both groups of experiments (necrosis and cirrhosis) the antimicrobial agents, with the exception of penicillin, were given mixed with the food. Their possible effect on the intestinal flora is discussed.
STUDIES ON IMMUNITY IN ANTHRAX
Authors: Wright George G. , Hedberg Mary A. , Feinberg Richard J.
Published: June 2004

Non-proteolytic mutants were isolated from the Vollum strain of B. anthracis following ultraviolet treatment. The mutants were virulent for rabbits and mice and their non-proteolytic character was stable in culture and on serial passage in rabbits. The mutants produced protective antigen under suitable conditions of cultivation in vitro, and allowed longer incubation of the cultures without destruction of the protective antigen than did the parent strain. The meaning of the results is discussed.
VARIABILITY OF BCG STRAINS (BACILLUS CALMETTE-GUÉRIN)
Authors: Suter W. Emanuel , Dubos René J.
Published: June 2004

Three different cultures of BCG propagated for over 2 years in a liquid medium containing Tween 80 and albumin were found to differ in several of their intrinsic properties.

Cultures of the three strains were found to consist of morphologically heterogeneous populations—each culture being made up of three main colonial types—spreading, intermediate, and non-spreading. The percentage distribution of colonial types was characteristic for each culture and remained constant during cultivation in liquid media.

Injection of the various cultures into mice and guinea pigs resulted in a self-limited disease. The distribution, extent, and duration of the lesions were also characteristic for each culture.

Both the spreading and non-spreading substrains derived from the various cultures exhibited the degree of attenuation of virulence characteristic of the parent strain.
STUDIES ON ACUTE DISSEMINATED ENCEPHALOMYELITIS PRODUCED EXPERIMENTALLY IN RHESUS MONKEYS
Authors: Kabat Elvin A. , Wolf Abner , Bezer Ada E. , Murray Jean P.
Published: June 2004

The white cell count, total protein, gamma globulin, and percentage of gamma globulin in the cerebrospinal fluid of monkeys with acute disseminated encephalomyelitis produced by the injection of brain emulsions with adjuvants have been studied.

The acute phase of the disease is characterized by a rise in the white cell count, total protein, and gamma globulin in the cerebrospinal fluid. In some instances the percentage of gamma globulin, to the total protein may be normal while in others it is elevated.

As the acute process subsides, the total protein declines and animals frequently show an increase in the percentage of gamma globulin to total protein. The relation of the cerebrospinal fluid findings in acute disseminated encephalomyelitis in the rhesus monkey to those in human multiple sclerosis is discussed.