Elicitation of high-frequency cytotoxic T-lymphocyte responses against both dominant and subdominant simian-human immunodeficiency virus epitopes by DNA vaccination of rhesus monkeys.

Increasing evidence suggests that the generation of cytotoxic T-lymphocyte (CTL) responses specific for a diversity of viral epitopes will be needed for an effective human immunodeficiency virus type 1 (HIV-1) vaccine. Here, we determine the frequencies of CTL responses specific for the simian immunodeficiency virus Gag p11C and HIV-1 Env p41A epitopes in simian-human immunodeficiency virus (SHIV)-infected and vaccinated rhesus monkeys. The p11C-specific CTL response was high frequency and dominant and the p41A-specific CTL response was low frequency and subdominant in both SHIV-infected monkeys and in monkeys vaccinated with recombinant modified vaccinia virus Ankara vectors expressing these viral antigens.

New role for Shc in activation of the phosphatidylinositol 3-kinase/Akt pathway.

Most, if not all, cytokines activate phosphatidylinositol 3-kinase (PI-3K). Although many cytokine receptors have direct binding sites for the p85 subunit of PI-3K, others, such as the interleukin-3 (IL-3) receptor beta common chain (betac) and the IL-2 receptor beta chain (IL-2Rbeta), lack such sites, leaving the mechanism by which they activate PI-3K unclear. Here, we show that the protooncoprotein Shc, which promotes Ras activation by recruiting the Grb2-Sos complex in response to stimulation of cytokine stimulation, also signals to the PI-3K/Akt pathway.

Augmentation of immune responses to HIV-1 and simian immunodeficiency virus DNA vaccines by IL-2/Ig plasmid administration in rhesus monkeys.

The potential utility of plasmid DNA as an HIV-1 vaccination modality currently is an area of active investigation. However, recent studies have raised doubts as to whether plasmid DNA alone will elicit immune responses of sufficient magnitude to protect against pathogenic AIDS virus challenges. We therefore investigated whether DNA vaccine-elicited immune responses in rhesus monkeys could be augmented by using either an IL-2/Ig fusion protein or a plasmid expressing IL-2/Ig.

Use of major histocompatibility complex class I/peptide/beta2M tetramers to quantitate CD8(+) cytotoxic T lymphocytes specific for dominant and nondominant viral epitopes in simian-human immunodeficiency virus-infected rhesus monkeys.

To evaluate the impact of the diversity of antigen recognition by T lymphocytes on disease pathogenesis, we must be able to identify and analyze simultaneously cytotoxic T-lymphocyte (CTL) responses specific for multiple viral epitopes. Many of the studies of the role of CD8(+) CTLs in AIDS pathogenesis have been done with simian immunodeficiency virus (SIV)- and simian-human immunodeficiency virus (SHIV)-infected rhesus monkeys. These studies have frequently made use of the well-defined SIV Gag CTL epitope p11C,C-M presented to CTL by the HLA-A homologue molecule Mamu-A*01.

Emergence of CTL coincides with clearance of virus during primary simian immunodeficiency virus infection in rhesus monkeys.

The CTL response was characterized during primary SIV/macaque (SIVmac) infection of rhesus monkeys to assess its role in containing early viral replication using both an epitope-specific functional and an MHC class I/peptide tetramer-binding assay. The rapid expansion of a single dominant viral epitope-specific CTL population to 1.3-8.

Viral burden and disease progression in rhesus monkeys infected with chimeric simian-human immunodeficiency viruses.

To determine the role of viral burden in simian-human immunodeficiency virus (SHIV)-induced disease, cellular provirus and plasma viral RNA levels were measured after inoculation of rhesus monkeys with four different SHIVs. These SHIVs included SHIV-HXBc2 and SHIV-89.6, constructed with env, tat, rev, and vpu derived from either cell line-passaged or primary patient isolates of human immunodeficiency virus type 1; the viral quasispecies SHIV-89.

JC virus DNA load in patients with and without progressive multifocal leukoencephalopathy.

Objective: To determine the clinical value of JC virus (JCV) detection in various anatomic compartments for the diagnosis of progressive multifocal leukoencephalopathy (PML).

Methods: CSF, peripheral blood mononuclear cells (PBMC), plasma, and urine samples were evaluated from HIV-infected and uninfected individuals. JCV DNA was detected by PCR and was quantified using a competitive PCR ELISA.

Comparative analysis of cytotoxic T lymphocytes in lymph nodes and peripheral blood of simian immunodeficiency virus-infected rhesus monkeys.

Most studies of human immunodeficiency virus type 1 (HIV-1)-specific cytotoxic T lymphocytes (CTL) have been confined to the evaluation of these effector cells in the peripheral blood. What has not been clear is the extent to which CTL activity in the blood actually reflects this effector cell function in the lymph nodes, the major sites of HIV-1 replication. To determine the concordance between CTL activity in lymph nodes and peripheral blood lymphocytes (PBL), CTL specific for simian immunodeficiency virus of macaques (SIVmac) have been characterized in lymph nodes of infected, genetically selected rhesus monkeys by using both Gag peptide-specific functional CTL assays and tetrameric peptide-major histocompatibility complex (MHC) class I molecule complex staining techniques.

Non-uniform triple helical structure in chick skin type I collagen on thermal denaturation: Raman spectroscopic study.

The individual chains in the triple helix of collagen occur in a conformation related to polyproline II because of the presence of large number of imino peptide bonds. However, these residues are not evenly distributed in the collagen molecule which also contains many non-imino residues. These non-imino regions of collagen may be expected to show preference for other than triple helical conformations.

Administration of recombinant human interleukin 12 to chronically SIVmac-infected rhesus monkeys.

With the demonstration that interleukin 12 can enhance natural killer (NK) cell activity and drive CD4+ lymphocytes toward T helper type 1 (Thl) responses, there is a strong rationale for exploring the use of this cytokine as an immunomodulatory therapy in HIV-1-infected individuals. To assess its potential safety and effects on both immune and virologic aspects of HIV-1 infection, recombinant human IL-12 (rhIL-12) was assessed in rhesus monkeys chronically infected with the simian immunodeficiency virus of macaques (SIVmac). The activity of rhIL-12 on rhesus monkey lymphocytes was confirmed with the demonstration that peripheral blood lymphocyte lysis of the NK-sensitive cell line Colo was enhanced by this recombinant cytokine.

Interlaboratory variation in oxygen tension measurement by Eppendorf "Histograph" and comparison with hypoxic marker.

Background And Objectives: The median of pO2 values in tumor measured by Eppendorf "Histograph" with a needle-type electrode has been used as a prognostic indicator in cancer patients. However, it is not established that a pretreatment measured pO2 value can be used as a universal predictor of local control probability, because the variation in pO2 values, especially in hypoxic tissue, among institutes may not allow comparison of measured "absolute pO2 values." The purpose of this study was to examine the variation in oxygen tension measurement by Eppendorf "Histograph" among six laboratories using a single batch of mice and tumors and the same detailed protocol.

Potent, protective anti-HIV immune responses generated by bimodal HIV envelope DNA plus protein vaccination.

It is generally thought that an effective vaccine to prevent HIV-1 infection should elicit both strong neutralizing antibody and cytotoxic T lymphocyte responses. We recently demonstrated that potent, boostable, long-lived HIV-1 envelope (Env)-specific cytotoxic T lymphocyte responses can be elicited in rhesus monkeys using plasmid-encoded HIV-1 env DNA as the immunogen. In the present study, we show that the addition of HIV-1 Env protein to this regimen as a boosting immunogen generates a high titer neutralizing antibody response in this nonhuman primate species.

Persistent infection of macaques with simian-human immunodeficiency viruses.

Chimeric simian-human immunodeficiency viruses (SHIV) containing the human immunodeficiency virus type 1 (HIV-1) tat, rev, env, and, in some cases, vpu genes were inoculated into eight cynomolgus monkeys. Viruses could be consistently recovered from the CD8-depleted peripheral blood lymphocytes of all eight animals for at least 2 months. After this time, virus isolation varied among the animals, with viruses continuing to be isolated from some animals beyond 600 days after inoculation.

Role of CD26/dipeptidyl peptidase IV in human immunodeficiency virus type 1 infection and apoptosis.

To examine the role of CD26/dipeptidyl peptidase IV (DPPIV; EC 3.4.14.

Infection of cynomolgus monkeys with a chimeric HIV-1/SIVmac virus that expresses the HIV-1 envelope glycoproteins.

Replication competent chimeric viruses that express the gag and pol proteins of SIVmac and the env proteins of HIV-1 were made. One such chimeric virus, SHIV-4, that expresses the vif, vpx, vpr, and nef regulatory genes of SIV and the tat and rev regulatory genes of HIV-1 replicated efficiently in cynomolgus monkeys. This model system can be used to evaluate the efficacy of anti-HIV-1 vaccines directed at the envelope glycoproteins, anti-HIV-1 envelope glycoprotein antiserum or monoclonal antibodies, and anti-HIV-1 drugs designed to inhibit the tat, rev, or env functions.

Prediction of major cardiac events after peripheral vascular surgery using dipyridamole echocardiography.

Patients undergoing peripheral vascular surgery are at increased risk of postoperative cardiac complications. To evaluate the role of dipyridamole echocardiography in predicting major cardiac events, 109 unselected patients undergoing elective peripheral vascular surgery were prospectively studied. Preoperative dipyridamole echocardiograms were interpreted by an echocardiographer unaware of all clinical data.

Fractures of allografts. Frequency, treatment, and end-results.

One of the major complications of implantation of a massive frozen cadaveric allograft in the treatment of a tumor is fracture of the allograft. To determine the incidence, risk factors, appropriate management, and results of treatment of this complication, the records of the Orthopaedic Oncology Unit of the Massachusetts General Hospital were reviewed. Forty-three patients were identified in whom a tumor had been treated with an allograft that had subsequently fractured.

Renal mineralization--a ubiquitous lesion in chronic rat studies.

Renal mineralization is a commonly encountered lesion in old rats and its presence at times complicates the interpretation of data derived from chronic rat studies. The feeding of sucralose, a new and high-intensity sweetener under regulatory review, resulted in caecal enlargement and an increase in the incidences of renal mineralization and pelvic epithelial hyperplasia. These responses prompted a review of the literature focusing on the relationships, if any, between the caecal and renal changes.

Effects of nifedipine on transmitral Doppler blood flow velocity profile in patients with concentric left ventricular hypertrophy.

To examine the effects of calcium channel blockade on left ventricular diastolic function, transmitral blood flow was evaluated by Doppler echocardiography following administration of sublingual nitroglycerin and nifedipine in 10 younger normal subjects and in 10 subjects with concentric left ventricular hypertrophy (LVH) and abnormal Doppler transmitral flow patterns. Nitroglycerin decreased peak early filling velocity (E velocity) in both normal (p less than 0.01) and LVH subjects (p less than 0.

Prospective Doppler echocardiographic evaluation of pulmonary artery diastolic pressure in the medical intensive care unit.

To test the hypothesis that the noninvasive evaluation of pulmonary regurgitation can provide accurate estimates of pulmonary artery (PA) diastolic pressures and PA wedge pressures, Doppler echocardiographic studies were performed immediately before bedside PA catheterization in 29 medical intensive care unit patients. The characteristic color flow Doppler signal of pulmonary regurgitation was detected in 19 (66%) patients. In 17 of the 29 patients (59%), the gradient between the right ventricle and PA at end-diastole could be calculated from the pulsed-wave Doppler signal of pulmonary regurgitation using the simplified Bernoulli equation.

Synergy between subtherapeutic doses of cyclosporine and immunobiological manipulations in rat heart graft recipients.

Cyclosporine in combination with other chemical or biological immunosuppressive modalities has been useful in clinical and experimental organ transplantation. In these studies, the efficacy of adjunctive subtherapeutic doses of CsA given to immunologically enhanced heart graft recipients or to animals treated with an anti-IL-2 receptor monoclonal antibody (ART18) are described. Individually, the treatment entities are only partially effective.

Infection in bone allografts. Incidence, nature, and treatment.

Of 283 patients who had a massive allograft of bone, an infection developed in thirty-three (11.7 per cent). To assess the frequency and identify the co-morbid and predisposing factors of this devastating complication, we compared demographic data for the infected and non-infected patients.