Endoscopic ultrasound-guided inoculation of transmissible venereal tumor in the colon: A large animal model for colon neoplasia.

Background: To develop and evaluate the feasibility of emerging interventions, animal models with accurate anatomical environment are required.

Objectives: We aimed to establish a clinically relevant colorectal tumor model with canine transmissible venereal tumor (CTVT) utilizing endoscopic ultrasound (EUS) imaging guidance.

Design: Survival study using a canine model.

Dependence of DCE-MRI biomarker values on analysis algorithm.

Background: Dynamic contrast-enhanced MRI (DCE-MRI) biomarkers have proven utility in tumors in evaluating microvascular perfusion and permeability, but it is unclear whether measurements made in different centers are comparable due to methodological differences.

Purpose: To evaluate how commonly utilized analytical methods for DCE-MRI biomarkers affect both the absolute parameter values and repeatability.

Materials And Methods: DCE-MRI was performed on three consecutive days in twelve rats bearing C6 xenografts.

Requirement for ssbp2 in hematopoietic stem cell maintenance and stress response.

Transcriptional mechanisms governing hematopoietic stem cell (HSC) quiescence, self-renewal, and differentiation are not fully understood. Sequence-specific ssDNA-binding protein 2 (SSBP2) is a candidate acute myelogenous leukemia (AML) suppressor gene located at chromosome 5q14. SSBP2 binds the transcriptional adaptor protein Lim domain-binding protein 1 (LDB1) and enhances LDB1 stability to regulate gene expression.

Reproducibility and comparison of DCE-MRI and DCE-CT perfusion parameters in a rat tumor model.

Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and computed tomography (DCE-CT) provide independent measures of biomarkers related to tumor perfusion. We compared the reproducibilities and absolute values of DCE-MRI and DCE-CT biomarkers in the same tumors in an animal model, to investigate the physiologic validity of both approaches. DCE-MRI and DCE-CT were each performed sequentially on three consecutive days in each of twelve rats bearing C6 glioma xenografts.

Inactivation of CBF/NF-Y in postnatal liver causes hepatocellular degeneration, lipid deposition, and endoplasmic reticulum stress.

We previously demonstrated that CBF activity is needed for cell proliferation and early embryonic development. To examine the in vivo function of CBF in differentiated hepatocytes, we conditionally deleted CBF-B in hepatocytes after birth. Deletion of CBF-B resulted in progressive liver injury and severe hepatocellular degeneration 4 weeks after birth.

SIV-specific CD8+ T cells are enriched in female genital mucosa of rhesus macaques and express receptors for inflammatory chemokines.

Problem: Mucosal T lymphocyte responses in the female reproductive tract, the primary site of HIV transmission in women, may be critical for initial control of virus infection. In addition, characterization of genital immune responses to HIV will be important for the development of a vaccine capable of preventing infection by this route.

Method Of Study: We analyzed lymphocytes isolated from vagina and cervix of chronically SIV-infected macaques for the frequency of SIV Gag tetramer-binding cells and expression of chemokine receptors.

Magnetic resonance guided, focal laser induced interstitial thermal therapy in a canine prostate model.

Purpose: We evaluated a newly Food and Drug Administration cleared, closed loop, magnetic resonance guided laser induced interstitial thermal therapy system for targeted ablation of prostate tissue to assess the feasibility of targeting, real-time monitoring and predicting lesion generation in the magnetic resonance environment.

Materials And Methods: Seven mongrel dogs (University of Texas Health Science Center, Houston, Texas) with (2) and without (5) canine transmissible venereal tumors in the prostate were imaged with a 1.5 T magnetic resonance imaging scanner.

Ability of herpes simplex virus vectors to boost immune responses to DNA vectors and to protect against challenge by simian immunodeficiency virus.

The immunogenicity and protective capacity of replication-defective herpes simplex virus (HSV) vector-based vaccines were examined in rhesus macaques. Three macaques were inoculated with recombinant HSV vectors expressing Gag, Env, and a Tat-Rev-Nef fusion protein of simian immunodeficiency virus (SIV). Three other macaques were primed with recombinant DNA vectors expressing Gag, Env, and a Pol-Tat-Nef-Vif fusion protein prior to boosting with the HSV vectors.

Identification of T lymphocytes in simian immunodeficiency virus encephalitis: distribution of CD8+ T cells in association with central nervous system vessels and virus.

T lymphocytes are found within brains infected with human immunodeficiency virus (HIV) or simian immunodeficiency virus (SIV) where they are a minor, but consistently identified, population. However, little analysis of their phenotypes has been done, and questions concerning whether or not they are viral antigen specific has not been thoroughly examined. We investigated the central nervous system (CNS) of SIV-infected rhesus macaques to identify T-lymphocyte subsets in relation to virus-infected cells and brain microvessels.

Limited contribution of humoral immunity to the clearance of measles viremia in rhesus monkeys.

The development of an improved vaccine for controlling measles virus (MV) infections in the developing world will require an understanding of the immune mechanisms responsible for the clearance of this virus. To evaluate the role of humoral immunity in the containment of MV, rhesus monkeys were treated at the time of MV challenge with either anti-CD20 monoclonal antibody (MAb) infusion, to deplete B lymphocytes, or both anti-CD20 and anti-CD8 MAb, to deplete both B lymphocytes and CD8+ effector T lymphocytes. Although the MV-specific antibody response in CD20+ lymphocyte-depleted monkeys was delayed by >1 week, the kinetics of MV clearance did not differ from those for monkeys that received control MAb.

Experimental rhesus lymphocryptovirus infection in immunosuppressed macaques: an animal model for Epstein-Barr virus pathogenesis in the immunosuppressed host.

To develop a model for Epstein-Barr virus (EBV) pathogenesis in immunosuppressed hosts, we studied experimental infections of immunocompetent versus SHIV 89.6P-infected, immunosuppressed rhesus macaques with the EBV-related rhesus lymphocryptovirus (LCV). Primary LCV infection after oral inoculation of 4 immunocompetent animals was characterized by an acute viremia and seroconversion followed by asymptomatic LCV persistence.

Molecular evidence for rhesus lymphocryptovirus infection of epithelial cells in immunosuppressed rhesus macaques.

Epstein-Barr virus (EBV) is a human oncogenic herpesvirus associated with epithelial cell and B-cell malignancies. EBV infection of B lymphocytes is essential for acute and persistent EBV infection in humans; however, the role of epithelial cell infection in the normal EBV life cycle remains controversial. The rhesus lymphocryptovirus (LCV) is an EBV-related herpesvirus that naturally infects rhesus macaques and can be used experimentally to model persistent B-cell infection and B-cell lymphomagenesis.

Role of CD8(+) lymphocytes in control and clearance of measles virus infection of rhesus monkeys.

The creation of an improved vaccine for global measles control will require an understanding of the immune mechanisms of measles virus containment. To assess the role of CD8(+) cytotoxic T lymphocytes in measles virus clearance, rhesus monkeys were depleted of CD8(+) lymphocytes by monoclonal anti-CD8 antibody infusion and challenged with wild-type measles virus. The CD8(+) lymphocyte-depleted animals exhibited a more extensive rash, higher viral loads at the peak of virus replication, and a longer duration of viremia than did the control antibody-treated animals.