Merle Mizell

Limb Regeneration: Induction in the Newborn Opossum

The marsupial Didelphys virginiana (the North American opossumn) is uniquely suited for studies of mammalian limb replacement. By transplanting nervous tissute to the limb, regeneration has been successfully induced in this mammal.

Tumor Induction in Developing Frog Kidneys by a Zonal Centrifuge Purified Fraction of the Frog Herpes-Type Virus

Injection of frog embryos (Rana pipiens) with a zonal centrifuge purified fraction of herpes-type virus (prepared from virus-containing Luck� tumors) resulted in a high incidence of kidney tumors. This partially purified oncogenic fraction contained a high concentration of an enveloped form of the frog herpes-type virus (adjacent fractions lacked this particle and were not oncogenic), which suggests that this form of the virus plays a role in the genesis of the Luck� tumor.

Paper chromatographic separation of amino acids: A solvent to replace phenol

Abstract The solvent n-butanol—methyl ethyl ketone—water (2:2:1) with an atmosphere saturated with cyclohexylamine yields excellent separation of mixtures of all the common acids, is readily reproducible, lacks the capriciousness of phenolic systems, and furthermore, imparts distinctive colors to many of the amino acids after ninhydrin treatment. These characteristics colors serve to confirm identification based on control runs for these amino acids and also serve as valuable “landmarks” facilitating the identification of adjacent amino acids that have the customary purple ninhydrin color.

Opossum Fetuses Grown in Culture

Opossum fetuses explanted at limb bud stages have been successfully grown in culture for periods up to 20 hours. Blood circulation was maintained, and organogenesis continued at about the same rate as in vivo.

Herpes-type virus recovery from "virus-free" frog kidney tumors.

Summary Virus production was induced by low temperature treatment of the “virus-free” form of the frog renal adenocarcinoma (Lucké tumor). Virus recovered after this low temperature treatment fulfilled the morphological requirements of herpesvirus. Herpesvirus development was also induced in eye chamber transplants from these “virus-free” primary tumors. Results indicate that the two naturally-occurring seasonal forms of this tumor are temperature-related states of the same tumor and suggest that the “virus-free” tumor contains a relatively complete viral genome in masked or latent form.

Electron microscopic observations on herpes-type virus-related structures in the frog renal adenocarcinoma☆

Abstract Tubular structures and double-shelled spherical particles were regularly observed in nuclei of frog renal adenocarcinoma cells which contained the herpes-type virus of this tumor. Morphological observations and virus development studies have indicated that the spherical particles give rise to 35-mμ tubules, which subsequently serve as cores for 65-mμ tubules. The outer sheath of the larger tubule consists of capsomeres similar to those comprising virus capsids, indicating a relationship between tubular structures and virus particles. A morphological similarity between spherical particles and an internal double-shelled structure of immature virus particles suggests that the spherical particles are also virus-related. Evidence is presented which indicates that both the spherical particles and tubular forms are aberrant structures regularly produced during virus replication in the frog kidney tumor.

The origin of immunoglobulins in opossum “embryos”☆

Abstract The appearance of immunoglobulins was studied in newborn and known aged pouch young opossums. Newborn serum collected from the neonate prior to the animals attachment to the teat, was studied for the first time. This newborn serum displayed a total lack of immunoglobulins. However, immunoglobulins were found present 12 hr after attachment and results indicated that the opossum embryos receive immunoglobulins through the mothers milk. The initial absence, the first appearance, and the later increase in concentration of these immunoglobulins was studied in a series of developing embryos using blood serum from known-aged neonates. IgG- and IgM-like serum proteins were identified in the adult opossum and a third protein class with IgA-like characteristics was isolated. Both IgG- and IgA-like antibodies were also identified in opossum milk.

State of the Art: Lucké Renal Adenocarcinoma

Amphibians are subject to the same range of neoplasms found in higher vertebrates; renal adenocarcinomas, lymphomas, lymphosarcomas, plasmacytomas and melanomas are among those which have been described. The Lucke tumor, a renal adenocarcinoma of the leopard frog, Rana pipiens, is undoubtedly the best understood of these cold-blooded tumors. This transmissable tumor has become the subject of increasingly intensified interest because of recent significant contributions to an understanding of its suspected viral etiology.

Ectopic Hermaphroditic Gonad in the Cranial Cavity of Japanese Medaka

Abstract Diseases were monitored for 1 year in a cohort of approximately 560 Japanese medakas Oryzias latipes kept in a laboratory at Tulane University. The fish were maintained as part of a breeding colony for embryological studies. Eighty-six fish exhibiting disease or injury during the year were examined histopathologically. Two adult Japanese medakas (one male and one female) had ectopic hermaphroditic gonads in the cranial cavity. The ectopic gonads were bordered by meninges and cranium. The ectopic gonads in both cases consisted mostly of spermatocytes and spermatids with numerous islands of primary germ cells and a few ovarian follicles. An ectopic gonad in the cranial cavity has not been previously reported in vertebrates.

A Preliminary Report on the Serology of Lucké and Burkitt Herpes-type Viruses: A Shared Antigen

Serological analysis of the Herpes-type virus (HTV) associated with cell lines derived from patients with Burkitt lymphoma has revealed two classes of antigens: a) soluble components detected by immunoprecipitation (12), and b) capsid antigens, most clearly demonstrated by coating reactions visualized by electron microscopy (4, 9). Immunoprecipitation, immunofluorescence, and complement-fixation tests indicate a high incidence of antibody to Burkitt HTV antigen in human populations (3, 5, 6, 7, 12). This antibody is found most frequently in patients with Burkitt lymphoma, lymphosarcoma, chronic lymphatic leukemia, and nasopharyngeal carcinoma (11). Naturally occurring antibodies to antigens related to this virus are not restricted to man, but are also found in the chimpanzee, and other subhuman primates (3, 11).