Reoviruses are ether-resistant icosahedral viruses 60 to 75 mp in diameter which contain ribonucleic acid. They have been recovered from man and lower animals and are ubiquitous in their geographic distribution. At present, the importance of these viruses as a cause of human or animal disease is still largely unknown. As a result of having a number of unusual characteristics, reoviruses have attracted the attention of many workers in the relatively short time since they were first recognized. For example, investigators interested in the molecular aspects of virology have been attracted by the...

The herpes group consists of viruses which have been placed together on the basis of a number of distinguishing features that they share in common (ANDRE- WES, 1962). All these viruses are relatively large, possess identical morphological characteristics, contain DNA, and are extremely sensitive to inactivation by ether; these viruses are also assembled within the nucleus of the host cell and induce the formation of eosinophilic intranuclear inclusions. The epidemiology of some of the best known viruses in this group (herpes simplex, pseudorabies, and B-virus) is also similar (BURNET et aI. ,...

A. Definitions of Transformation in vitro When normal tissues or organs are explanted to conditions favoring the growth of cells as individual units ("cell culture"), the original cell population undergoes a large variety of modifications. Only a minority of the cells will thrive and multiply and within a rather short period of time, the complex composition of the original explant is replaced by a much simplified one of only a few recogniz ably different cell types. With most organs fibroblast-like cells survive longest and outgrow other types. This is then a stable state of affairs for many...

I. Introduction Of the ever increasing number of viruses known to affect man and higher animals, the virus of lymphocytic choriomeningitis (LCM) was one of the first to be discovered. Indeed, this virus has been known and maintained in the laboratory by passages in a relatively simple host, the mouse, for 35 years. Yet our knowl- edge of its properties is still scanty when compared with the wealth of informa- tion available for other viruses, some of which have come to our attention much more recently. There are at least four reasons which may help to explain this seeming paradox. (1) The...

2 D. Immunological Response . . . . . . . . . . . . . . . . . . . . 78 1. Thymectomy in LDV Infection . . . . . . . . . . . . . . . . 81 2. Effect of LDV Infection on Immune Response to Various Antigenic Stimuli. . . . . 82 E. Tumour Growth . . 87 F. Histological Changes 91 VII. Ecology . . . . . . . 97 VIII. Laboratory Methods. . 100 A. Blood Samples from Mice for LDH Estimation . 100 B. Estimation of Plasma LDH Activity . . 101 1. Quantitative Methods. . . . . . . . 101 a) Determination of Plasma LDH by Spectrophotometric Method (Backward Reaction) . . . . . . . . . . . . . . . 101 b)...

I. Introduction In his biography "Arrow in the Blue" the author Arthur Koestler suggests ironically that the fate of an individual may be predicted by examining the content of the newspapers at birth. Adenoviruses were discovered in 1953 (ROWE et al. , 1953; HILLEMAN and WERNER, 1954). At this time the Salk poliomyelitis vaccine was developed (SALK et al. , 1954) and in the same year the discovery of the double helical structure of DNA (WATSON and CRICK, 1953) and the plaque assay for one animal virus (DULBECCO and VOGT, 1953) was announced. Thus, this new group of viruses was born with great...

I. Introduction Parvoviruses belong to the large group of viral agents of which virologists have become aware by chance in many biological materials due to the availabil ity of more sensitive isolation techniques and the extensive use of the electron microscope. In general, many of these viruses lacked the stimulating background of an infectious disease and, therefore, have fallen into oblivion already soon after discovery. In case of parvoviruses, however, interest has been maintained because of the circumstances under which most of them were isolated. A great number of parvoviruses has been...

2. Virological Findings. 90 3. Immunity...90 C. Secondary Dengue: Dengue Hemorrhagic Fever and the Shock Syndrome 92 1. General Remarks...92 2. Clinical Course and Clinical Laboratory Findings 93 3. Virological and Serological Findings...95 4. Immunopathology of Secondary Dengue. 98 XI. Immunization...104 A. Anamnestic Immune Responses in Sequential Infections With Dengue and Other Group B Togaviruses ...104 1. Results With Members of the Dengue Subgroup 104 2. Results With Dengue and Other Flaviviruses. 107 B. Dengue Vaccines for Use in Man 108 XII. Opportunities for the Future 113...

l RNA tumor viruses have become increasingly utilized in studies of cellular transformation and gene regulation. The genes of retroviruses exist in two forms; as extrachromosomal, RNA-containing, infectious particles and as DNA pro 2 viruses stably associated with cell genes. Components from the extracellular form can be collected in large quantity and purified for the preparation of molec ular probes. These probes can be used to dissect the sequence of events required for the establishment and expression of the integrated form. Furthermore the 2 genomes of retroviruses originated from normal...