Search PubMed⌕ Search

Biomedical subjects

R D Hunt

Publications and source records attributed to R D Hunt.

At least 37 records · Page 2Linked to original sources

Induction of AIDS-like disease in macaque monkeys with T-cell tropic retrovirus STLV-III.

The T-cell tropic retrovirus of macaque monkeys STLV-III has morphologic, growth, and antigenic properties indicating that it is related to HTLV-III/LAV, the etiologic agent of the acquired immune deficiency syndrome (AIDS) in humans. Four of six rhesus monkeys died within 160 days of STLV-III inoculation with a wasting syndrome, opportunistic infections, a primary retroviral encephalitis, and immunologic abnormalities including a decrease in T4+ peripheral blood lymphocytes. These data show that an immunodeficiency syndrome can be produced experimentally in a nonhuman primate by an agent from the HTLV-III/LAV group of retroviruses. The STLV-III-macaque system will thus provide a useful model for the study of antiviral agents and vaccine development for human AIDS.

Acquired Immunodeficiency Syndrome↗

Isolation of T-cell tropic HTLV-III-like retrovirus from macaques.

The isolation of a T-cell tropic retrovirus from three immunodeficient macaques and one macaque with lymphoma is described. The morphology, growth characteristics, and antigenic properties of this virus indicate that it is related to the causative agent of acquired immune deficiency syndrome in humans (HTLV-III or LAV). This virus is referred to as simian T-lymphotropic virus type III (STLV-III) of macaques. The existence of a cytopathic, T-cell tropic virus resembling HTLV-III in monkeys may facilitate study of disease induction and vaccine development in an animal model.

Acquired Immunodeficiency Syndrome↗

Serologic identification and characterization of a macaque T-lymphotropic retrovirus closely related to HTLV-III.

Human T-lymphotropic virus type III (HTLV-III) is thought to play an etiologic role in the development of the acquired immune deficiency syndrome (AIDS). In this study the serologic characterization of a new simian retrovirus that is related to HTLV-III is described. This new virus, here referred to as STLV-III, was isolated from sick macaques at the New England Regional Primate Research Center. Radioimmunoprecipitation analysis revealed STLV-III-specific proteins of 160, 120, 55, and 24 kilodaltons, all similar in size to the major gag and env proteins of HTLV-III. These antigens were recognized by representative macaque serum samples and human reference serum samples positive for HTLV-III antibodies. Monoclonal antibodies directed to p24, the major core protein of HTLV-III, also immunoprecipitated a 24-kilodalton species in lysates of cells infected with the macaque virus. This HTLV-III-related virus, which naturally infects a nonhuman primate species, may provide a useful model for the study of HTLV-III and the pathogenesis of AIDS.

Acquired Immunodeficiency Syndrome↗

A region of the Herpesvirus saimiri genome required for oncogenicity.

Herpesvirus saimiri naturally infects squirrel monkeys (Saimiri sciureus) without producing signs of disease; infection of other New World primates, however, results in a rapidly progressing, malignant, T-cell lymphoma. Results described in this report identify a region of the viral genome that is required for oncogenicity in owl monkeys (Aotus trivirgatus); this region is not required for replication of the virus. This is believed to be the first such genomic region identified in a herpesvirus system.

Animals↗

Retrovirus D/New England and its relation to Mason-Pfizer monkey virus.

Seventeen isolates of retrovirus D/New England have been obtained from three species of macaques at the New England Regional Primate Research Center. Seven of the isolates were obtained from macaques who subsequently died with the macaque immunodeficiency syndrome; other isolates were obtained from macaques with less severe or other forms of illness. Attempts to isolate type D retrovirus from peripheral lymphocytes of 97 apparently healthy macaques have not been successful. Cloned DNA was prepared from Hirt supernatants of cells infected with one of these isolates (D/New England 398). By restriction endonuclease analysis, cloned pD398 DNA represented full-length viral DNA with one long terminal repeat. A detailed restriction endonuclease map of pD398 was derived and compared with a map of the cloned Mason-Pfizer monkey virus genome. Forty-six percent (13 of 28) of restriction endonuclease sites were found to be conserved when these related viruses were compared. Five of the D/New England isolates, including those from three different macaque species, were examined for strain variability by restriction endonuclease typing. Comparison of over 30 restriction endonuclease sites has not distinguished any of these D/New England isolates. It thus appears that a single strain of type D retrovirus is infecting three different species of macaques in the New England colony. Markedly reduced cross-hybridization was observed between cloned pD398 and Mason-Pfizer monkey virus DNAs at high stringency; this reduced cross-hybridization was localized to the pol-env regions of the genome. Only very weak hybridization of D/New England DNA to cloned squirrel monkey type D retrovirus DNA could be detected even at low-stringency conditions. What role type D retrovirus plays in the immunodeficiency syndrome of macaques remains to be determined.

Animals↗

Possible change in noradrenergic receptor sensitivity following methylphenidate treatment: growth hormone and MHPG response to clonidine challenge in children with attention deficit disorder and hyperactivity.

Growth hormone (GH) and 3-methoxy-4-hydroxyphenelethylene glycol (MHPG) response was measured hourly for 4 hours in 8 children with Attention Deficit Disorder with Hyperactivity (ADD+H) following an acute single-dose of clonidine. The clonidine challenge was repeated before, during, and one day after 12 weeks of treatment with methylphenidate (MPH). Before MPH treatment, the plasma growth hormone (GH) rose to 31.3 +/- 4.6 (Mean +/- SE) ng/ml; during MPH treatment, the GH peak was only 14.8 +/- 3.2 ng/ml; one day after discontinuation of MPH, GH rose to only 20.8 +/- 3.9 ng/ml. MHPG release was inhibited by clonidine in all treatment conditions but tended to be more decreased during MPH treatment. Some children with ADD+H may have hypersensitivity of the post-synaptic alpha-1 noradrenergic receptor which is diminished by MPH treatment. The extent to which these effects are pharmacological or represent a change in receptor sensitivity requires further study.

Adolescent↗

Lymphoma in macaques: association with virus of human T lymphotrophic family.

Human T-cell leukemia virus has been linked with adult T-cell leukemia-lymphoma (ATLL), a tumor of mature T cells that occurs at elevated rates in southwestern Japan and in the Caribbean Basin. Human T-cell leukemia virus (HTLV) or a closely related virus, has also been found in varying proportions of healthy individuals of several species of Old World monkeys. In the present study, conducted with macaques from Taiwan and the New England Regional Primate Research Center, antibodies to membrane antigens of HTLV-infected cells (HTLV-MA) were found in 11 of 13 macaques with malignant lymphoma or lymphoproliferative disease but in only 7 of 95 of healthy macaques. This indicates that antibodies to HTLV are significantly associated with the development of naturally occurring lymphoid neoplasms in at least some species of nonhuman primates.

Animals↗

A new type D retrovirus isolated from macaques with an immunodeficiency syndrome.

Macaque monkeys with the recently described acquired immunodeficiency syndrome show a marked defect in T-lymphocyte function and die with opportunistic infections and lymphoproliferative abnormalities. In the study described here a new type D retrovirus was isolated from two Macaca cyclopis with this syndrome. This virus is related to, but distinct from, Mason-Pfizer monkey virus, a type D retrovirus previously isolated from a mammary tumor of a rhesus monkey (Macaca mulatta).

Animals↗

Psychiatric aspects of learning difficulties.

This article describes the process of clinical assessment that may lead to differential treatment of psychiatric-related learning difficulties. The authors review differences in information processing among individuals with attention, affective, and primary thought disorders.

Adult↗

Experimental infection of rhesus monkeys with type D retrovirus.

The naturally occurring immunodeficiency syndrome of macaque monkeys is an important animal model for the acquired immunodeficiency syndrome in humans. A new type D retrovirus, distinct from Mason-Pfizer monkey virus, has been isolated from affected animals at the New England Regional Primate Research Center. We now report the results of experimental infection of macaques with retrovirus D/New England after 13 months of study. Inoculated macaques developed lymphadenopathy without follicular hyperplasia, profound neutropenia, and a transient decrease in peripheral blood lymphocyte blastogenic responsiveness. Despite our varying the strain of virus, the manner in which the virus was grown, the size of the inoculum, and the age of the inoculated animals, infected macaques have not developed opportunistic infections or profound, prolonged loss of T cell function, key features of the macaque immunodeficiency syndrome. Therefore, experimental infection of naive macaques with D/New England has not reproduced the naturally occurring macaque immunodeficiency syndrome.

Acquired Immunodeficiency Syndrome↗

Animal models of AIDS.

Explore the source record for details and available documents.

Acquired Immunodeficiency Syndrome↗

Experimental transmission of macaque AIDS by means of inoculation of macaque lymphoma tissue.

Acquired immuno-deficiency syndrome (AIDS) of macaques, an animal model for human AIDS, was transmitted to previously healthy macaque monkeys by means of inoculation of either tissue or a cell-free filtrate of a macaque lymphoma. The recipients showed evidence of profound lymphocyte dysfunction or died with infections from such opportunistic agents as Candida albicans, Cryptosporidium, and cytomegalovirus.

Acquired Immunodeficiency Syndrome↗

T lymphocyte surface antigens in primates.

We examined the binding of peripheral blood mononuclear cells from various primate species to a panel of monoclonal antibodies with specificity for human T lymphocytes. A remarkable structural conservation of the erythrocyte rosette receptor on T cells between such phylogenetically distant primates as lemurs and man was found. Furthermore, it was demonstrated that the degree of sharing of other T cell-specific surface determinants between man and other primates reflects the phylogenetic distance between them. Moreover, these studies suggest the potential use of monoclonal antibodies for further structural and functional elucidation of T lymphocyte-specific surface structures.

Animals↗