S100A13 is involved in the regulation of fibroblast growth factor-1 and p40 synaptotagmin-1 release in vitro

We have previously characterized the release of the signal peptide sequence-less fibroblast growth factor (FGF) prototype, FGF-1, in vitro as a stress-induced pathway in which FGF-1 is released as a latent homodimer with the p40 extravesicular domain of p65 synaptotagmin (Syn)-1. To determine the biologic relevance of the FGF-1 release pathway in vivo, we sought to resolve and characterize from ovine brain a purified fraction that contained both FGF-1 and p40 Syn-1 and report that the brain-derived FGF-1:p40 Syn-1 aggregate is associated with the calcium-binding protein, S100A13. Since S100A13 binds the anti-inflammatory compound amlexanox and FGF-1 is involved in inflammation, we examined the effects of amlexanox on the release of FGF-1 and p40 Syn-1 in response to stress in vitro. We report that while amlexanox was able to repress the heat shock-induced release of FGF-1 and p40 Syn-1 in a concentration-dependent manner, it had no effect on the constitutive release of p40 Syn-1 from p40 Syn-1 NIH 3T3 cell transfectants. These data suggest the following: (i) FGF-1 is associated with Syn-1 and S100A13 in vivo; (ii) S100A13 may be involved in the regulation of FGF-1 and p40 Syn-1 release in response to temperature stress in vitro; and (iii) the FGF-1 release pathway may be accessible to pharmacologic regulation.     

Major histocompatibility complex class I presentation of exogenous soluble tumor antigen fused to the B-fragment of Shiga toxin

Targeting exogenous antigen into the MHC class I-restricted presentation pathway is a prerequisite for the induction of cytotoxic T lymphocytes (CTL) which have been shown to represent an important component of the protective and therapeutic immune response to viral infections and tumors. In this study, we produced recombinant proteins composed of the receptor-binding non-toxic B-fragment of bacterial Shiga toxin derived from Shigella dysenteriae associated with an epitope from a model tumor antigen, Mage 1. We show that Shiga B-Mage 1 fusion proteins carrying an active or inactive endoplasmic reticulum retrieval signal (the C-terminal peptides KDEL or KDELGL, respectively) could be presented by peripheral blood mononuclear cells in an MHC class I-restricted manner to Mage 1-specific CTL. After pulsing B lymphoblastoid cells or dendritic cells with Shiga B-Mage 1 fusion protein, activation of the MHC class I-restricted Mage 1-specific CTL was also demonstrated. In further analysis, we showed that treatment with brefeldin A or paraformaldehyde fixation of Epstein-Barr virus-transformed B cells prevented the presentation of the Mage 1 T cell epitope, which excluded extracellular processing of the antigen. Immunofluorescence analysis also revealed that the Shiga B-Mage 1 fusion protein was largely excluded from Lamp-2-positive lysosomal structures. Therefore, the ability of Shiga toxin B-fragment to target dendritic cells and B cells and to direct antigen into the exogenous class I-restricted pathway makes it an attractive non-living and non-toxic vaccine vector.     

Stimulus duration, neural adaptation, and sweep visual evoked potential acuity estimates

PURPOSE: Results in several studies have suggested that the visual evoked potential (VEP) amplitude can vary with stimulus duration. The purpose of this study was to determine whether acuity estimates obtained by extrapolation of the sweep VEP are altered by this adaptation effect. METHODS: Sweep VEP data were obtained from 16 healthy observers under binocular viewing conditions. Data were acquired with a commercially available VEP unit using standard electrode recording techniques. Three sweeps (high spatial frequencies, medium spatial frequencies, and low spatial frequencies) were run. The subjects' visual acuity at the monitor distance was 6/6 for the high spatial frequency sweep. For the medium and low spatial frequency sweeps, the subjects were dioptrically blurred to 6/15 (medium spatial frequencies) or 6/30 (low spatial frequencies) at the monitor distance. Each sweep consisted of six spatial frequencies (contrast 80%; temporal frequency (TF) = 7.5 Hz; screen luminance = 100 candela [cd]/m2). For each spatial frequency, the stimulus duration was 8 seconds, partitioned into 1-second bins. A minimum of eight sweeps were obtained per subject. An acuity estimate was obtained for each second's data by fitting a line to the high spatial frequencies (excluding noise) and extrapolating this line to the x-axis. With this technique, estimates could not be obtained for 29 of 384 possible acuities. RESULTS: The sweep VEP acuities for the 16 subjects did not change significantly over the 8 seconds of data collection for the high, medium, or low spatial frequency sweep (repeated measures analysis of variance [ANOVA]: high, P = 0.25; medium, P = 0.50; low, P = 0.23). In any given subject, there was a 1- to 2-octave range in acuity estimates over the 8 seconds of stimulus presentation (high, 1.23+/-0.417 octaves; medium, 1.41+/-0.593 octaves; low, 1.52+/-0.475 octaves; mean +/- SD). CONCLUSIONS: These results suggest that there is not a significant change in sweep VEP acuity estimates over an 8-second stimulus presentation. Thus, neural adaptation does not significantly affect the clinical use of the sweep VEP.     

Chimaera and its modern virus-like descendants

Chimaera was a monster in ancient Greek mythology combining elements from different animal species in its body. Modern molecular biology enabled the generation of harmless but useful chimaeras consisting of elements from different nonrelated viruses. The objective is that the resulting chimaeras form highly immunogenic virus-like particles (VLPs). Such chimaeric VLPs can be used as highly efficient carriers for sequential and conformational B cell epitopes and T cell epitopes. Most VLPs are readily produced in heterologous hosts and are easy to purify. This article deals with various systems of VLPs described in this topical issue of Intervirology and makes comparisons with chimaeric replication-competent viruses, recombinant virus vectors expressing foreign proteins, and DNA vaccines.     

Adoptive immunotherapy for leukemia: donor lymphocytes transduced with the herpes simplex thymidine kinase gene for remission induction. HGTRI 0103

This study will evaluate the safety and efficacy of allogenic donor lymphocyte infusions in patients who have relapsed hematologic malignancies after allogeneic bone marrow transplantation (BMT). Donor lymphocyte transfusions have resulted in the cure of some patients with relapsed leukemia or lymphoproliferative disorder after allogeneic BMT, but has been complicated by the development of graft versus host disease (GvHD). We hypothesize that a retroviral vector containing the Herpes simplex thymidine kinase (HStk) gene will allow for retention of the anti-leukemia response of transfused donor lymphocytes while allowing for the adverse effects of GVHD to be mitigated. Patients with relapsed hematologic malignancies after allogeneic BMT will be infused with ex vivo gene modified donor lymphocytes. The Herpes Simplex thymidine kinase (HStk) gene will be transduced into the cells ex vivo using LTKOSN. 1 vector supernate. Insertion of the HStk gene into lymphocytes confers a sensitivity to the anti-herpes drug ganciclovir (GCV). This selective destruction of donor lymphocytes in situ will be used to abrogate the effect of graft versus host disease, if it develops.     

Value of diuretics in hypertension

Diuretics still remain a cornerstone in the treatment of hypertension. Adverse effects such as disorders of the carbohydrate and lipid metabolism as well as development of hypokalemia or hypomagnesemia are obviously directly correlated to the administered dosage. Therefore, there is increasing agreement for low-dose drug therapy. In contrast to hydrochlorothiazide treatment, metabolic disorders are less commonly encountered with indapamide therapy. A pronounced diuretic efficacy is linked to the combined use of diuretics which act on different segments of the nephron (for example administration of a loop diuretic together with a thiazide). In chronic renal failure indapamide appears to be superior to hydrochlorothiazide considering preservation of renal function. In contrast to thiazides, indapamide is the therapy of choice in patients with diabetes.     

Detection of antibodies to equine arteritis virus by enzyme linked immunosorbant assays utilizing G(L), M and N proteins expressed from recombinant baculoviruses

On the experience of 73 patients, the authors state their guidelines on the treatment of bone metastases on the cervical spine. Most of the cases on which no vertebral collapse occur neither neurological deficit, radiation therapy and external support are suggested. Surgery is necessary on case of severe bone destruction, collapse with or without subsequent neurological impairment. Anterior excision is considered the best approach, sometimes complemented by posterior stabilisation.