bluuebunny/crossref_metadata_2025 huggingface dataset:
EXPERIMENTAL STUDIES ON ENCEPHALITIS
Authors: Webster Leslie T. , Clow Anna D. , Bauer Johannes H.
Published: June 2004

Anopheles quadrimaculatus mosquitoes, fed on mice in which encephalitis virus (St. Louis type) is present in the blood stream, take up and retain the virus for the duration of their lives.

The titre of the virus in mosquitoes 4 hours after engorging on mice with a maximum blood stream infection represents about 10,000 lethal mouse intracerebral doses per mosquito. This titre drops during the following 2 weeks to about 100 lethal doses per mosquito, but from the 3rd week to the death of the mosquito, usually increases to approximately the original level and remains there.

The titre of virus in mosquitoes which have engorged on mouse blood containing smaller quantities of virus exhibits the same drop and subsequent rise to the original level.

The virus-containing mosquitoes did not infect mice or monkeys by biting.
PRIMARY SERUM TOXICITY AS DEMONSTRATED BY THE CHICKEN EMBRYO
Authors: Witebsky Ernst , Neter Erwin
Published: June 2004

1. The 3 day old chicken embryo removed from its shell is a suitable test object for the demonstration of primary serum toxicity. Addition of normal rabbit type sera as well as Forssman antiserum causes the vascular network to contract and the embryo sinks in the yolk and dies.

2. Only sera of animals of the so called rabbit type produce this phenomenon. Sera of the guinea pig type are ineffective.

3. Heating to 51°C. destroys the complement content of normal human serum as also its effectiveness to produce the vascular phenomenon.

4. Up to the present it has not been possible to reactivate heat-inactivated normal serum by the addition of complement, while inactivated Forssman antiserum can be easily reactivated.

5. The vascular phenomenon of the chicken embryo is produced not only by the addition of a mixture of Forssman antiserum and complement but also by separate addition of both components.

6. Guinea pig type sera, containing dissolved Forssman antigen, are not only ineffective but actually exert an inhibitory influence on effective rabbit type sera as well as on Forssman antiserum.
CULTIVATION OF THE VIRUS OF GRASSERIE IN SILKWORM TISSUE CULTURES
Authors: Trager William
Published: June 2004

A medium has been developed in which certain cells from the gonads of female silkworms multiply and live for periods of 2 to 3 weeks.

In such tissue cultures, strains of silkworm grasserie virus were maintained in successive passages up to the number of ten. The virus multiplied greatly and typical polyhedral bodies formed in the cells of infected cultures.
STUDIES ON THE HEMOLYTIC STREPTOCOCCUS OF HUMAN ORIGIN
Authors: Lyons Champ , Ward Hugh K.
Published: June 2004

1. Anantiserum which specifically protects mice against a virulent culture (M variant) of the hemolytic streptococcus contains specific opsonin. Phagocytosis of the organisms can be observed in the peritoneum of the protected mouse.

2. An antiserum prepared by injecting an animal with the living M variant specifically opsonizes both the F and the M variant of the strain.

3. Evidence is presented which indicates the probable identity of the specific opsonin and the anti-M precipitin of Lancefield (7). Agglutination appears to be dependent upon a different antibody.

4. It is possible to type the hemolytic streptococci by means of specific opsonins, and the opsonic method has certain advantages over agglutination, precipitation, and mouse protection tests. It is evident from what little has been done that there are many types.

5. The serum of infants contains no opsonin for the virulent hemolytic streptococci, but the serum of adults may contain specific opsonins for certain strains. Inasmuch as no opsonins were demonstrable in two polyvalent antibacterial sera examined, the possibilities of therapeutic transfusion are discussed.
THE PRECIPITIN REACTION BETWEEN TYPE III PNEUMOCOCCUS POLYSACCHARIDE AND HOMOLOGOUS ANTIBODY
Authors: Heidelberger Michael , Kendall Forrest E.
Published: June 2004

The experiments recorded above show that in the case of antipneumococcus horse serum or purified antibody the arbitrary immunological procedure (37° for 2 hours, overnight in the ice box) does not permit either the establishment of a true equilibrium or the precipitation of the maximum amount of antibody nitrogen. Analyses of such horse sera for antibody content should therefore be carried out at 0° and the determinations should be allowed to stand in the cold for at least 24 hours in order to insure the completion of the reaction.

It is believed that the similarity of the nitrogen: S III ratios in the specific precipitate, whether obtained from whole serum or from purified antibody, and the failure of added serum to influence the amount of nitrogen precipitated show that the absolute chemical method for the estimation of antibody actually measures antibody and not antibody plus a more or less indefinite amount of non-specific protein. An objection to the use of the method is thus shown to be unfounded.
THE PRECIPITIN REACTION BETWEEN TYPE III PNEUMOCOCCUS POLYSACCHARIDE AND HOMOLOGOUS ANTIBODY
Authors: Heidelberger Michael , Kendall Forrest E.
Published: June 2004

The precipitin reaction between the specific polysaccharide of Type III pneumococcus and homologous antibody formed in the horse can be accounted for quantitatively by assuming the chemical combination of the components in a bimolecular reaction, followed by a series of competing bimolecular reactions which depend upon the relative proportions of the components. These reactions would lead to the formation of larger and larger aggregates until precipitation ultimately occurred. The mathematical formulation of this theory on the basis of the mass law is described. The derived expressions are shown to be in accord with the experimental findings and the constants used in these expressions are shown to have definite significance. In spite of the wide variation in the properties of individual sera these expressions permit the complete description of the behavior of an unknown serum with S III without an unduly burdensome number of analyses.

The quantitative theory presented has been found applicable to other instances of the precipitin reaction, as will be shown in subsequent papers.
THE RELATION OF LEUKOSIS TO SARCOMA OF CHICKENS
Authors: Stubbs E. L. , Furth J.
Published: June 2004

A transmissible strain of sarcoma (Strain 13) is described that took its origin in a chicken inoculated with leukosis of Strain 1. The virus of Strain 13 produces sarcoma in the breast muscle injected with it and after intravenous inoculation it produces diffuse sarcomatosis of the spleen, bone marrow, and several other organs.

The available evidence suggests that Strain 13 is caused by a single virus with ability to produce diffuse endothelial growth in the blood-forming organs associated with extensive hematomata, and erythroblastic proliferation.

The strain can be readily transmitted by material free from live cells and preserved by drying. As small amounts of blood as 0.00001 cc. from chickens with sarcomatosis of the internal organs transmit Strain 13 by the intravenous route.

By implantation sarcoma of Strain 13 can be transferred to chickens that are resistant to repeated inoculations with leukotic viruses.
THE FIXATION AND PROTECTION OF VIRUSES BY THE CELLS OF SUSCEPTIBLE ANIMALS
Authors: Rous Peyton , McMaster Philip D. , Hudack Stephen S.
Published: June 2004

Methods were developed for a study of the relations existing between viruses and living cells. It was found that vaccinia and the virus causing the infectious fibroma of rabbits (Shope) rapidly become fixed upon tissue cells freed as individuals and submitted to virus in suspension. This happens whether the cells are alive or have been killed with heat or ultraviolet light. The virus does not come away during agitation of the cells with Tyrode solution and repeated washings with large amounts of it. The exposure to neutralizing antisera of cells carrying virus fails to affect this latter significantly if the cells are alive, whereas if they are dead the activity of the virus is nullified. Cells freed as individuals from tissue cultures of vaccinia and the Shope tumor carry these viruses in abundance through repeated washings, and, if living, protect them from the influence of a neutralizing serum, whereas killed cells exert no such protection.

The findings would appear to throw light on the way in which viruses gain a foothold in the host; and they suggest reasons for the persistence of some viruses in recovered animals and for the unsatisfactory results of serum treatment instituted during the course of virus diseases.

The virus causing the Shope fibroma has been successfully maintained in cultures of the growth. It is closely associated with the cells, almost none being present in the culture fluid. Certain of its other attributes have been determined. Vaccinia greatly damages the cells of cultures of rabbit embryo in which it is under propagation.
ENCEPHALOMYELITIS ACCOMPANIED BY MYELIN DESTRUCTION EXPERIMENTALLY PRODUCED IN MONKEYS
Authors: Rivers Thomas M. , Schwentker Francis F.
Published: June 2004

The repeated intramuscular injections of aqueous emulsions and alcohol-ether extracts of sterile normal rabbit brains in some manner produced pathological changes accompanied by myelin destruction in the brains of 7 of 8 monkeys (Macacus rhesus). Eight, control monkeys remained well. Cultures from the involved brains remained sterile, and no transmissible agent was demonstrated by means of intracerebral inoculations of emulsions of bits of the brains into monkeys, rabbits, guinea pigs, and white mice.
MULTIPLICATION IN VITRO OF PSEUDORABIES VIRUS IN THE TESTICLE TISSUE OF IMMUNIZED GUINEA PIGS
Authors: Traub Erich
Published: June 2004

Pseudorabies virus was cultivated in vitro in washed testicle tissue from immune guinea pigs, and evidence was thus procured which indicated that the testicle cells themselves had not become immune to pseudorabies. The rate of multiplication of the virus was considerably greater in control cultures with normal guinea pig testis than in cultures with immune testis. The reason for this fact may be that even by repeated washing the immune tissue could not be completely freed from fluid antibodies, and that such antibodies somewhat inhibited the multiplication of the virus.
THE EFFECT OF FASTING ON THE SERUM PROTEIN CONCENTRATION OF THE RAT
Authors: Torbert Harold C.
Published: June 2004

1. Experiments were carried out to test the hypothesis that there exists a special circulating fraction of plasma protein available for use by the tissues.

2. The changes in serum protein concentration after varying periods of fasting were followed in large numbers of individual rats.

3. Previous reports from this laboratory of a small initial drop in the total protein concentration of the serum, with subsequent maintenance of the serum protein at the new level are confirmed.

4. Evidence is offered that this initial fall involves chiefly or solely the albumin fraction.

5. The mechanism responsible for the observed initial drop and subsequent maintenance of the protein is not exactly known, but two definite factors are age and individual resistance.

6. It is concluded that no satisfactory evidence is available to support the hypothesis of a directly utilizable protein fraction in the blood.
EXPERIMENTS ON THE EPIDEMIOLOGY OF PSEUDORABIES
Authors: Shope Richard E.
Published: June 2004

Study of the pseudorabies virus-neutralizing antibody content of pooled and individual samples of swine serum have led to the conclusion that pseudorabies is a highly prevalent, unrecognized, disease in middle western hogs.

It has been shown that wild brown rats develop a fatal infection following ingestion of pseudorabies virus and that their carcasses, in turn, give rise to the disease in swine to which they are fed. It is believed that rats play a rôle in the epidemiology of porcine pseudorabies, serving as the initial source of infection for a swine herd and also as one means by which virus can be spread from farm to farm in swine herds. The experiments presented furnish further evidence that swine may serve as the source of infection for cattle.
IMMUNOLOGICAL AND CHEMICAL INVESTIGATIONS OF VACCINE VIRUS
Authors: Parker Robert F. , Rivers Thomas M.
Published: June 2004

By means of differential centrifugation in the horizontal and angle centrifuges it is possible to obtain appreciable quantities of relatively pure elementary bodies of vaccinia. Such preparations of elementary bodies exhibit an extremely high titer of vaccine virus.

The elementary bodies are specifically agglutinated by serum from rabbits immunized by means of injections of bacteria-free vaccine virus.

Virus-free filtrates of dermal vaccine virus and of bacteria-free testicular vaccine virus contain a soluble substance or substances that is precipitated by antivaccinal sera.
INTERSTITIAL BRONCHOPNEUMONIA
Authors: Sprunt Douglas H. , Martin Donald S. , Williams Jarrett E.
Published: June 2004

Bacterial toxins can produce a pneumonia similar to that caused by viruses, and the presence of a toxin-producing bacterium in the lungs may account for some of the interstitial bronchopneumonias observed in diseases other than those caused by viruses.
PATHOGENIC ORGANISMS OF THE GENUS LISTERELLA
Authors: Seastone C. V.
Published: June 2004

From meningitis in man, encephalitis in cattle and sheep, a myocardial infection in fowl, and a generalized infection in rabbits, different observers have isolated Gram-positive organisms which are closely related. Their cultural and serological properties are described. When injected intravenously into chickens, rabbits, or guinea pigs there is an unusual blood response, the monocytes being markedly increased. The organisms tend to localize in the myocardium with resulting necrosis.
A MODIFIED METHOD OF OBTAINING LARGE AMOUNTS OF RICKETTSIA PROWAZEKI BY ROENTGEN IRRADIATION OF RATS
Authors: Macchiavello Atilio , Dresser Richard
Published: June 2004

The radiation method described by Zinsser and Castaneda for obtaining large amounts of Rickettsia has been carried out successfully with an ordinary radiographic machine. This allows the extension of the method to those communities which do not possess a high voltage Roentgen therapy unit as originally employed.
RABBIT POX
Authors: Greene Harry S. N.
Published: June 2004

The epidemiological significance of age, race, sex, genetic constitution and physiological status were studied by means of a differential analysis of the mortality data derived from a devastating epidemic of rabbit pox and, with the exception of sex, were found to be factors of the utmost importance in the determination of susceptibility.

Young animals were more susceptible than adults and although the most susceptible age varied with the epidemic phase, it corresponded in general with the period of weaning. The influence of physiological status was further indicated by the increased susceptibility incident to lactation.

Racial variations in susceptibility were obscured by age factors in young animals, but were of profound importance in the adult population and formed the most significant feature of the analysis. A high degree of conformity was found in the susceptibility of racially related breeds, and this similarity in behavior increased with the proximity of relationship. Moreover, a study of the hybrids obtained from the crossing of pure breeds showed that two separable groups of hereditary factors were concerned in the determination of breed susceptibility, one group consisting of essential racial characters, the other of constitutional factors incorporated in the stock by chance association, and that the final expression of susceptibility or resistance was the result of their combined interaction.
THE PROTECTIVE ACTION OF TYPE I ANTIPNEUMOCOCCUS SERUM IN MICE
Authors: Goodner Kenneth , Horsfall Frank L.
Published: June 2004

The mouse protection test for the evaluation of type specific antipneumococcus serum has been studied with reference to the quantitative relationships between the amount of antibody and the number of injected bacteria. By varying both these factors through wide limits certain definite characteristics of the protection test have been defined. These are the Schwellenwert, the prozone, and the limiting titer zone. The modifications produced in the manifestations of these characteristics by changes in the technic of performing the test and also by certain non-specific reagents are described. The dependence of the outcome of the test upon variable factors intrinsic to the host is discussed.
AN APPARATUS FOR THE CULTURE OF WHOLE ORGANS
Authors: Lindbergh C. A.
Published: June 2004

An apparatus has been developed which maintains, under controllable conditions, a pulsating circulation of sterile fluid through organs for a length of time limited only by the changes in the organ and in the perfusion fluid.
THE INFECTION OF MICE WITH SWINE INFLUENZA VIRUS
Authors: Shope Richard E.
Published: June 2004

The experiments confirm the earlier observation of Andrewes, Laidlaw and Smith that the swine influenza virus is pathogenic for white mice when administered intranasally. Two field strains of the swine influenza virus were found to differ in their initial pathogenicity for mice. One strain was apparently fully pathogenic even in its 1st mouse passage while the other required 2 or 3 mouse passages to acquire full virulence for this species. Both strains, however, were initially infectious for mice, without the necessity of intervening ferret passages. There is no evidence that bacteria play any significant rôle in the mouse disease though essential in that of swine, and fatal pneumonias can be produced in mice by pure virus infections. Mice surviving the virus disease are immune to reinfection for at least a month. In mice the disease is not contagious though it is notably so in swine. The virus, while regularly producing fatal pneumonias when administered intranasally to mice, appears to be completely innocuous when given subcutaneously or intraperitoneally. Prolonged serial passage of the virus in mice does not influence its infectivity or virulence for swine or ferrets. It is a stable virus so far as its infectivity is concerned, and can be transferred at will from any one of its three known susceptible hosts to any other.

In discussing these facts the stability of the swine influenza virus has been contrasted with the apparent instability of freshly isolated strains of the human influenza virus. Though the mouse is an un-natural host for the virus it is, nevertheless, useful for the study of those aspects of swine influenza which have to do with the virus only.
CUTANEOUS REACTIVITY OF IMMUNE AND HYPERSENSITIVE RABBITS TO INTRADERMAL INJECTIONS OF HOMOLOGOUS INDIFFERENT STREPTOCOCCUS AND ITS FRACTIONS
Authors: McEwen Currier , Swift Homer F.
Published: June 2004

Rabbits were immunized intravenously with intact indifferent streptococci, with homologous P fraction, and with an emulsion of mechanically ground cocci; others were sensitized by intravenous injection of the intact microorganisms. Their serologic and dermal reactions to these materials and to the homologous S fraction were compared with those of normal animals. The dissociation, in certain instances, between circulating antibody and dermal reactivity was noteworthy. From the results the following conclusions were drawn.

1. Intradermal injection of a soluble streptococcal protein into a rabbit immunized intravenously with that protein leads to the immediate anaphylactic type of skin response; while similar dermal testing of a rabbit sensitized by intracutaneous inoculation of the intact microorganism induces the delayed (tuberculin) type of response.

2. The induction of the immediate type of dermal reaction to streptococcal protein requires more than the mere presence of a high serum precipitin titer to that protein.

3. Lesions of the immediate type can be induced by the intradermal injection of a streptococcal carbohydrate into rabbits immunized intravenously with intact cocci and showing a high serum precipitin titer to that carbohydrate.

4. Intravenous immunization of rabbits with an emulsion of mechanically ground indifferent streptococci leads to the production of only non-type-specific antibodies.

5. It is possible that carbohydrate as well as protein fractions of indifferent streptococci are capable of eliciting the delayed type of dermal response in rabbits intracutaneously sensitized with that microorganism.
DISTRIBUTION OF BLOOD GROUP PROPERTIES AND BLOOD GROUP PROPERTY DESTROYING FACTORS IN THE INTESTINAL TRACT OF MAN
Authors: Witebsky Ernst , Neter Erwin
Published: June 2004

1. The blood group specific substance A is present in the contents of the jejunum and upper ileum of persons belonging to Group A.

2. A marked decrease in the amount of A substance occurs in the lower ileum and cecum, while colon and rectum contents of adults are more or less free of group substance A.

3. The blood group destroying agent first appears in the lower ileum or cecum and its effectiveness increases in the lower parts of the large intestine.

4. In two cases with intestinal obstruction the blood group destroying agent could be demonstrated in the contents of the jejunum and ileum.
THE PHENOMENON OF LOCAL SKIN REACTIVITY TO BACTERIAL FILTRATES: ELICITATION OF LOCAL REACTIVITY BY WAY OF THE VASCULAR SYSTEM
Authors: Shwartzman Gregory
Published: June 2004

The skin of the rabbit's ear is considerably more resistant than the abdominal skin to the phenomenon of local skin reactivity to bacterial filtrates. Ten times the provocative dose is required if it is given into the vein of the prepared ear and thirty times the provocative dose if it is given into the vein of the non-prepared ear.

The state of reactivity cannot be elicited by a preparatory intravenous injection of bacterial filtrates alone into clamped and non-clamped ears. The state also fails to appear in combination with cold, xylol, ethyl urethane, pilocarpine hydrochloride, atropine, calcium gluconate, guinea pig liver extract, histamine dihydrochloride, adrenalin chloride, and pituitrin.

Preparatory intravenous injections of toxins are capable of eliciting the state of reactivity in the rabbit's ear when they are accompanied by thermal hyperemia (i.e., exposure to 45°, 50°, and 55°C.). It is also possible to induce the state of reactivity when a mixture of the preparatory factors with testicular extract is given into the veins of clamped ears. The incubation period required may be less than 2 hours.

In the light of the above experiments, there are discussed various observations concerning the elicitation of the phenomena of organ reactivity by means of live bacterial cultures and the filtrates thereof.
THE COLONY MORPHOLOGY OF TUBERCLE BACILLI
Authors: Smithburn Kenneth C.
Published: June 2004

All the strains of human tubercle bacilli described in this report as recently isolated from clinical cases proved to be virulent and showed but slight differences in pathogenic properties. Neither did they show extreme variation in virulence when compared with Strain H-37, isolated many years ago. Between twelve bovine strains cultivated in vitro for varying periods, there was a much wider range in virulence, some being so attenuated as to give regressive lesions in both rabbits and guinea pigs, while other strains were highly pathogenic. In general, the more recently isolated strains were the more virulent. Attenuation occurs with prolonged in vitro cultivation, but the rate of attenuation is apparently not the same for all strains.

Studies of cultures recovered from inoculated animals demonstrated that in the case of bovine tubercle bacilli virulence is correlated with three phenomena: the number of bacilli which can be stained in tissues of inoculated animals, the number of organisms recoverable in cultures from the tissues, and the proportion of smooth colonies in these cultures. All cultures of either human or bovine type recovered from animals showed either two or three types of colonies.

In general the percentage of the smooth form varied directly with virulence. However, some smooth colonies were present in strains having little or no pathogenicity. One example was cited of an avian strain which had lost its virulence while retaining the smooth colony form—indicating that, although pathogenicity is usually correlated with smooth colony form, it is not necessarily so. And smooth variants devoid of virulence do occur.

In the comparison of the effect of the same human strain on rabbits and guinea pigs, it was shown that native resistance (of the rabbit) was associated with a power to dissociate the inoculated bacilli into a greater proportion of rough forms, and then to destroy them. This power is not possessed by the naturally susceptible animal (guinea pig).
EPIDEMIOLOGY OF EQUINE ENCEPHALOMYELITIS IN THE EASTERN UNITED STATES
Authors: Tenbroeck Carl , Hurst E. Weston , Traub Erich
Published: June 2004

Equine encephalomyelitis of the eastern type is a disease of the late summer and fall and cases are found in greatest numbers near salt marshes. The epidemiological findings are against its transmission by contact and favor the view that it is insect borne. Although virus can be demonstrated in the blood of infected horses it is present for a relatively short time, and the possibility that the disease is not primarily an infection of horses but that it is transmitted to them from another host is considered.
THE TRANSMISSION OF EQUINE ENCEPHALOMYELITIS VIRUS BY AËDES AEGYPTI
Authors: Merrill Malcolm H. , Tenbroeck Carl
Published: June 2004

In confirming Kelser's work on the transmission of equine encephalomyelitis of the western type by Aëdes aegypti it has been learned that the mosquitoes must be fed virus of high titer if positive results are to be secured. A period of from 4 to 5 days after feeding either on infected guinea pigs or on brain containing virus must elapse before the disease is transmitted by biting, but after this time transmission regularly results for a period of about 2 months. By inoculation, virus can be demonstrated in the bodies of infected mosquitoes for the duration of life.

Although virus multiplies in the mosquitoes and is generally distributed in their bodies, repeated attempts to demonstrate it in the eggs from females known to be infected as well as in larvae, pupae, and adults from such eggs have been uniformly negative. Larvae have not taken up virus added to the water in which they were living.

Male mosquitoes have been infected with virus by feeding but they have not transmitted the virus to normal females, nor have males transmitted the virus from infected to normal females.

When virus of the eastern instead of the western type is used transmission experiments with Aëdes aegypti are negative. Apparently this virus is incapable of penetrating the intestinal mucosa of the mosquito. If, however, it is inoculated into the body cavity by needle puncture it persists and transmission experiments are positive.
FURTHER OBSERVATIONS ON THE BLOOD CHOLESTEROL OF RABBITS IN RELATION TO ATHEROSCLEROSIS
Authors: Turner Kenneth B. , Bidwell Emily H.
Published: June 2004

1. The action of potassium iodide in preventing a significant rise in the blood cholesterol of rabbits fed cholesterol was temporary. After about 4 months it lost its effectiveness and the blood cholesterol rose.

2. In rabbits with hypercholesterolemia resulting from long continued cholesterol feeding, the administration of potassium iodide caused a marked rise in the blood cholesterol.

3. On the other hand, dried whole thyroid given to such animals produced a sharp fall in the blood cholesterol. This fall was temporary and was followed by a rise to new high levels.

4. In thyroidectomized rabbits fed cholesterol and potassium iodide, both thyroid and thyroxin delayed but did not prevent a rise in blood cholesterol. Even with the hypercholesterolemia in these animals, however, the incidence of atherosclerosis was low.

5. Age apparently played a part in determining the response of the blood cholesterol to cholesterol feeding. In a group of old rabbits when compared with a younger group the rise in the cholesterol of the blood was greater and the subsequent return toward normal was slower when the feeding was stopped.
EXPERIMENTAL STUDIES ON ENCEPHALITIS
Authors: Webster Leslie T. , Fite George L. , Clow Anna D. , Muench Hugo
Published: June 2004

1. A protection test for measuring serological protective properties against the encephalitis (St. Louis type) virus is described.

2. Normal non-contact sera and sera from persons supposed to have had no exposure to the disease do not protect against the virus. 82.5 per cent of sera from tested St. Louis encephalitis convalescents and at least 66 per cent of sera from tested persons thought to have had the disease do show protective properties.

3. The protective activity of sera is maintained for at least 2½ years after onset of the disease. In vitro aging of serum decreases its activity.

4. Protection tests indicate that the virus was present as early as 1932 in Paris, Illinois, spread through the north central states and reached New York in 1933, and was again active in the north central states in 1934.
Participation of the Syntaxin 5/Ykt6/GS28/GS15 SNARE Complex in Transport from the Early/Recycling Endosome to theTrans-Golgi Network
Authors: Tai Guihua , Lu Lei , Wang Tuan Lao , Tang Bor Luen , Goud Bruno , Johannes Ludger , Hong Wanjin
Published: June 2004

An in vitro transport assay, established with a modified Shiga toxin B subunit (STxB) as a marker, has proved to be useful for the study of transport from the early/recycling endosome (EE/RE) to the trans-Golgi network (TGN). Here, we modified this assay to test antibodies to all known soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) that have been shown to localize in the Golgi and found that syntaxin 5, GS28, Ykt6, and GS15 antibodies specifically inhibited STxB transport. Because syntaxin 5, GS28, Ykt6, and GS15 exist as a unique SNARE complex, our observation indicates that these four SNAREs function as a complex in EE/RE-TGN transport. The importance of GS15 in EE/RE-TGN transport was further demonstrated by a block in recombinant STxB transport in HeLa cells when GS15 expression was knocked down by its small interfering iRNA. Morphological analyses showed that some GS15 and Ykt6 were redistributed from the Golgi to the endosomes when the recycling endosome was perturbed by SNX3-overexpression, suggesting that GS15 and Ykt6 might cycle between the endosomes and the Golgi apparatus. Further studies indicated that syntaxin 5 and syntaxin 16 exerted their role in EE/RE-TGN transport in an additive manner. The kinetics of inhibition exhibited by syntaxin 16 and syntaxin 5 antibodies is similar.
Belo Horizonte virus: a vaccinia-like virus lacking the A-type inclusion body gene isolated from infected mice
Authors: Trindade Giliane S. , da Fonseca Flávio G. , Marques João T. , Diniz Sueli , Leite Juliana A. , De Bodt Stefanie , Van der Peer Yves , Bonjardim Cláudio A. , Ferreira Paulo C. P. , Kroon Erna G.
Published: June 2004

Here is described the isolation of a naturally occurring A-type inclusion body (ATI)-negative vaccinia-like virus, Belo Horizonte virus (VBH), obtained from a mousepox-like outbreak in Brazil. The isolated virus was identified and characterized as an orthopoxvirus by conventional methods. Molecular characterization of the virus was done by DNA cross-hybridization using Vaccinia virus (VACV) DNA. In addition, conserved orthopoxvirus genes such as vaccinia growth factor, thymidine kinase and haemagglutinin were amplified by PCR and sequenced. All sequences presented high similarity to VACV genes. Based on the sequences, phenograms were constructed for comparison with other poxviruses; VBH clustered consistently with VACV strains. Attempts to amplify the ATI gene (ati) by PCR, currently used to identify orthopoxviruses, were unsuccessful. Results presented here suggest that most of the ati gene is deleted in the VBH genome.
Molecular characterization of Penicillium chrysogenum virus: reconsideration of the taxonomy of the genus Chrysovirus
Authors: Jiang Daohong , Ghabrial Said A.
Published: June 2004

Molecular cloning and complete nucleotide sequencing ofPenicillium chrysogenum virus(PcV) dsRNAs indicated that PcV virions contained four dsRNA segments with sizes of 3562, 3200, 2976 and 2902 bp. Each dsRNA segment had unique sequences and contained a single large open reading frame (ORF).In vitrotranslation of transcripts derived from full-length cDNA clones of PcV dsRNAs yielded single products of sizes similar to those predicted from the deduced amino acid sequences of the individual ORFs. Sequence similarity searches revealed that dsRNA1 encodes a putative RNA-dependent RNA polymerase. In this study, it was determined that dsRNA2 encodes the major capsid protein and that p4, encoded by dsRNA4, is virion-associated as a minor component. All four dsRNAs of PcV, like the genomic segments of viruses with multipartite genomes, were found to have extended regions of highly conserved terminal sequences at both ends. In addition to the strictly conserved 5′-terminal 10 nt, a second region consisting of reiteration of the sequence CAA was found immediately upstream of the AUG initiator codon. These (CAA)nrepeats are reminiscent of the translational enhancer elements of tobamoviruses. The 3′-terminal 14 nt were also strictly conserved. As PcV and related viruses with four dsRNA segments (genusChrysovirus) have not been previously characterized at the molecular level, they were provisionally classified in the familyPartitiviridae, comprising viruses with bipartite genomes. This study represents the first report on molecular characterization of a chrysovirus and the results suggest the creation of a new family of mycoviruses with multipartite dsRNA genomes to accommodate PcV and related viruses.
Sequences of flavivirus-related RNA viruses persist in DNA form integrated in the genome of Aedes spp. mosquitoes
Authors: Crochu Sandrine , Cook Shelley , Attoui Houssam , Charrel Remi N. , De Chesse Reine , Belhouchet Mourad , Lemasson Jean-Jacques , de Micco Philippe , de Lamballerie Xavier
Published: June 2004

Flavivirus-related sequences have been discovered in the dsDNA genome of Aedes albopictus and Aedes aegypti mosquitoes, demonstrating for the first time an integration into a eukaryotic genome of a multigenic sequence from an RNA virus that replicates without a recognized DNA intermediate. In the Aedes albopictus C6/36 cell line, an open reading frame (ORF) of 1557 aa with protease/helicase and polyprotein processing domains characteristic of flaviviruses was identified. It is closely related to NS1–NS4A genes of the Cell Fusing Agent and Kamiti River virus and the corresponding mRNAs were detected. Integrated sequences homologous to the envelope, NS4B and polymerase genes of flaviviruses were identified. Overall, approximately two-thirds of a flavivirus-like genome were characterized. In the Aedes aegypti A20 cell line, a 492 aa ORF related to the polymerase of the Cell Fusing Agent and Kamiti River virus was identified. These flavivirus-related integrated DNA sequences were detected in laboratory-bred and wild Aedes albopictus and Aedes aegypti mosquitoes, demonstrating that their discovery is not an artefact resulting from the manipulation of mosquito cell lines, since they exist under natural conditions. This finding has major implications regarding evolution, as it represents an entirely different mechanism by which genetic diversity may be generated in eukaryotic cells distinct from accepted processes.
Loss of virus-specific CD4+ T cells with increases in viral loads in the chronic phase after vaccine-based partial control of primary simian immunodeficiency virus replication in macaques
Authors: Lun Wen-Hui , Takeda Akiko , Nakamura Hiromi , Kano Munehide , Mori Kazuyasu , Sata Tetsutaro , Nagai Yoshiyuki , Matano Tetsuro
Published: June 2004

Virus-specific cellular immune responses play an important role in the control of immunodeficiency virus replication. However, preclinical trials of vaccines that induce virus-specific cellular immune responses have failed to contain simian immunodeficiency virus (SIV) replication in macaques. A defective provirus DNA vaccine system that efficiently induces virus-specific CD8+ T-cell responses has previously been developed. The vaccinated macaques showed reduced viral loads, but failed to contain SIVmac239 replication. In this study, macaques that showed partial control of SIV replication were followed up to see if or how they lost this control in the chronic phase. Two of them showed increased viral loads about 4 or 8 months after challenge and finally developed AIDS. Analysis of SIV-specific T-cell levels by detection of SIV-specific gamma interferon (IFN-γ) production revealed that these two macaques maintained SIV-specific CD8+ T cells, even after loss of control, but lost SIV-specific CD4+ T cells when plasma viral loads increased. The remaining macaque kept viral loads at low levels and maintained SIV-specific CD4+ T cells, as well as CD8+ T cells, for more than 3 years. Additional analysis using macaques vaccinated with a Gag-expressing Sendai virus vector also found loss of viraemia control, with loss of SIV-specific CD4+ T cells in the chronic phase of SIV infection. Thus, SIV-specific CD4+ T cells that were able to produce IFN-γ in response to SIV antigens were preserved by the vaccine-based partial control of primary SIV replication, but were lost with abrogation of control in the chronic phase.
Identification and analysis for cross-reactivity among hantaviruses of H-2b-restricted cytotoxic T-lymphocyte epitopes in Sin Nombre virus nucleocapsid protein
Authors: Maeda Ken , West Kim , Toyosaki-Maeda Tomoko , Rothman Alan L. , Ennis Francis A. , Terajima Masanori
Published: June 2004

Sin Nombre virus (SNV) causes hantavirus pulmonary syndrome (HPS), with a high rate of mortality in humans who are infected by the transmission of virus from the natural rodent host. In humans, cytotoxic T lymphocytes (CTL) specific for SNV appear to play an important role in the pathogenicity of HPS. There is a correlation between the frequencies of SNV-specific CTLs and the severity of HPS disease. In order to create a mouse model to study the role of SNV-specific T cellsin vivo, T cell responses to SNV nucleocapsid (N) protein in B6.PLThy1a/Cy mice (H-2b) immunized with plasmid DNA or recombinant vaccinia virus expressing SNV N protein were examined. Four peptides, NC94–101, NC175–189, NC217–231 and NC331–345, were recognized by CD8+T cells in CTL and ELISPOT assays in SNV N-immunized mice. Interestingly, two of these epitopes are located in the central region of the SNV N protein, where several human CD8+T-cell epitopes have been defined in Puumala virus and SNV. CTL lines specific for these four epitopes were cross-reactive to corresponding Puumala virus peptides, but only one of them was cross-reactive to Hantaan virus peptides. These results will enable the analysis of the roles of CTL in immunopathology of HPS in experimental mouse models of HPS.
Antibodies specific for hypervariable regions 3 to 5 of the feline immunodeficiency virus envelope glycoprotein are not solely responsible for vaccine-induced acceleration of challenge infection in cats
Authors: Huisman Willem , Schrauwen Eefje J. A. , Pas Suzan D. , Karlas Jos A. , Rimmelzwaan Guus F. , Osterhaus Albert D. M. E.
Published: June 2004

In a previous vaccination study in cats, the authors reported on accelerated feline immunodeficiency virus (FIV) replication upon challenge in animals vaccinated with a candidate envelope subunit vaccine. Plasma transfer studies as well as antibody profiles in vaccinated cats indicated a causative role for antibodies directed against the hypervariable regions HV3, HV4 and HV5 (HV3–5) of the envelope glycoprotein. The present study was designed to investigate further the contribution of antibodies in envelope vaccine-induced acceleration of FIV infection. To this end, regions HV3–5 of the envelope glycoprotein were deleted from the original vaccine, thus addressing the contributing role of antibodies directed against these hypervariable regions. Interestingly, this approach did not prevent acceleration of challenge infection. Analysis of the antibody responses in the respective groups suggested that removal of HV3–5 redirected the humoral immune response towards other regions of the envelope glycoprotein, indicating that these regions can also induce antibodies that accelerate virus replication.
Identification of the thymidylate synthase within the genome of white spot syndrome virus
Authors: Li Qin , Pan Deng , Zhang Jing-hai , Yang Feng
Published: June 2004

Thymidylate synthase (TS) (EC 2.1.1.45) is essential for thede novosynthesis of dTMP in prokaryotic and eukaryotic organisms. Within the white spot syndrome virus (WSSV) genome, an open reading frame (WSV067) that encodes a 289 amino acid polypeptide showed significant homology to all known TSs from species including mammals, plants, fungi, protozoa, bacteria and DNA viruses. In this study, WSV067 was expressed inEscherichia coli, and the purified recombinant protein showed TS activity in dUMP−folate-binding assays using ultraviolet difference spectroscopy. RT-PCR and Western blot analyses showed that WSV067 was a genuine and early gene. Phylogenetic analysis revealed that WSSV-TS was more closely related to the TSs of eukaryotes than to those from prokaryotes.
Characterization of an Ultraviolet B-Induced Lipase in Arabidopsis
Authors: Lo Maisie , Taylor Catherine , Wang Li , Nowack Linda , Wang Tzann-Wei , Thompson John
Published: June 2004

An Arabidopsis expressed sequence tag clone, 221D24, encoding a lipase has been characterized using an antisense approach. The lipase gene is expressed during normal growth and development of Arabidopsis rosette leaves but is down-regulated as the leaves senesce. When plants are exposed to sublethal levels of UV-B radiation, expression of the lipase is strongly up-regulated. The lipase protein is localized in the cell cytosol and is present in all organs of Arabidopsis plants. Recombinant lipase protein produced in Escherichia coli preferentially hydrolyzed phospholipids, indicating that the gene encodes a phospholipase. Transgenic plants in which lipase expression is suppressed showed enhanced tolerance to UV-B stress but not osmotic stress and were unable to up-regulate PR-1 expression when irradiated with UV-B. The observations collectively indicate that the lipase is capable of deesterifying membrane phospholipids and is up-regulated in response to UV-B irradiation.
Arabidopsis Downy Mildew Resistance Gene RPP27 Encodes a Receptor-Like Protein Similar to CLAVATA2 and Tomato Cf-9
Authors: Tör Mahmut , Brown Duncan , Cooper Abigail , Woods-Tör Alison , Sjölander Kimmen , Jones Jonathan D.G. , Holub Eric B.
Published: June 2004

The Arabidopsis Ler-RPP27 gene confers AtSgt1b-independent resistance to downy mildew (Peronospora parasitica) isolate Hiks1. The RPP27 locus was mapped to a four-bacterial artificial chromosome interval on chromosome 1 from genetic analysis of a cross between the enhanced susceptibility mutant Col-edm1 (Col-sgt1) and Landsberg erecta (Ler-0). A Cf-like candidate gene in this interval was PCR amplified from Ler-0 and transformed into mutant Col-rpp7.1 plants. Homozygous transgenic lines conferred resistance to Hiks1 and at least four Ler-0 avirulent/Columbia-0 (Col-0) virulent isolates of downy mildew pathogen. A full-length RPP27 cDNA was isolated, and analysis of the deduced amino acid sequences showed that the gene encodes a receptor-like protein (RLP) with a distinct domain structure, composed of a signal peptide followed by extracellular Leu-rich repeats, a membrane spanning region, and a short cytoplasmic carboxyl domain. RPP27 is the first RLP-encoding gene to be implicated in disease resistance in Arabidopsis, enabling the deployment of Arabidopsis techniques to investigate the mechanisms of RLP function. Homology searches of the Arabidopsis genome, using the RPP27, Cf-9, and Cf-2 protein sequences as a starting point, identify 59 RLPs, including the already known CLAVATA2 and TOO MANY MOUTHS genes. A combination of sequence and phylogenetic analysis of these predicted RLPs reveals conserved structural features of the family.
Genome-Wide in Silico Mapping of Scaffold/Matrix Attachment Regions in Arabidopsis Suggests Correlation of Intragenic Scaffold/Matrix Attachment Regions with Gene Expression
Authors: Rudd Stephen , Frisch Matthias , Grote Korbinian , Meyers Blake C. , Mayer Klaus , Werner Thomas
Published: June 2004

We carried out a genome-wide prediction of scaffold/matrix attachment regions (S/MARs) in Arabidopsis. Results indicate no uneven distribution on the chromosomal level but a clear underrepresentation of S/MARs inside genes. In cases where S/MARs were predicted within genes, these intragenic S/MARs were preferentially located within the 5′-half, most prominently within introns 1 and 2. Using Arabidopsis whole-genome expression data generated by the massively parallel signature sequencing methodology, we found a negative correlation between S/MAR-containing genes and transcriptional abundance. Expressed sequence tag data correlated the same way with S/MAR-containing genes. Thus, intragenic S/MARs show a negative correlation with transcription level. For various genes it has been shown experimentally that S/MARs can function as transcriptional regulators and that they have an implication in stabilizing expression levels within transgenic plants. On the basis of a genome-wide in silico S/MAR analysis, we found a significant correlation between the presence of intragenic S/MARs and transcriptional down-regulation.
Type-B Response Regulators Display Overlapping Expression Patterns in Arabidopsis
Authors: Mason Michael G. , Li Jie , Mathews Dennis E. , Kieber Joseph J. , Schaller G. Eric
Published: June 2004

Two-component signaling systems, involving His kinases, His-containing phosphotransfer proteins, and response regulators, have been implicated in plant responses to hormones and environmental factors. Genomic analysis of Arabidopsis supports the existence of 22 response regulators (ARRs) that can be divided into at least two distinct groups designated type-A and type-B. Phylogenetic analysis indicates that the type-B family is composed of one major and two minor subfamilies. The expression of the type-B ARRs was examined by using both reverse transcription-PCR and β-glucuronidase fusion constructs. The major subfamily of type-B ARRs showed particularly high expression in regions where cytokinins play a significant role, including cells in the apical meristem region and in young leaves that would be undergoing cell division. Multiple members within this same subfamily of type-B ARRs were expressed near the root tip with highest expression in the root elongation zone. β-Glucuronidase-fusions to full-length ARR2, ARR12, and ARR19 were nuclear localized, consistent with a role in transcriptional regulation. These data suggest that differing expression levels of the type-B ARRs may play a role in modulating the cellular responses to cytokinin.