Identification of two steroid-responsive promoters of different strength controlled by the same estrogen-responsive element in the 5'-end region of the Xenopus laevis vitellogenin gene A1.

A structural and functional analysis of the 5'-end region of the Xenopus laevis vitellogenin gene A1 revealed two transcription initiation sites located 1.8 kilobases apart. A RNA polymerase II binding assay indicates that both promoters form initiation complexes efficiently. In vitro, using a transcription assay derived from a HeLa whole-cell extract, the upstream promoter is more than 10-fold stronger than the downstream one. In contrast, both promoters have a similar strength in a HeLa nuclear extract. In vivo, that is in estrogen-stimulated hepatocytes, it is the downstream promoter homologous to the one used by the other members of the vitellogenin gene family, which is 50-fold stronger than the upstream promoter. Thus, if functional vitellogenin mRNA results from this latter activity, it would contribute less than 1% to the synthesis of vitellogenin by fully induced Xenopus hepatocytes expressing the four vitellogenin genes. In contrast, both gene A1 promoters are silent in uninduced hepatocytes. Transfection experiments using the Xenopus cell line B3.2 in which estrogen-responsiveness has been introduced reveal that the strong downstream promoter is controlled by an estrogen responsive element (ERE) located 330 bp upstream of it. The upstream promoter can also be controlled by the same ERE. Since the region comprising the upstream promoter is flanked by a 200 base pair long inverted repeat with stretches of homology to other regions of the X. laevis genome, we speculate that it might have been inserted upstream of the vitellogenin gene A1 by a recombination event and consequently brought under control of the ERE lying 1.5 kilobases downstream.

Prostaglandin A1 Inhibits Replication of Classical Swine Fever Virus

Prostaglandins (Pgs) have been shown to inhibit the replication of several DNA and RNA viruses. Here we report the effect of prostaglandin (PgA1) on the multiplication of a positive strand RNA virus, Classical Swine Fever Virus (CSFV) in PK15 cells. PgA1 was found to inhibit the multiplication of CSFV. At a concentration of 5 µg/ml, which was nontoxic to the cells, PgA1 inhibitis virus production in 99%. In PgA1 treated cells the size and number of characteristic Classical Swine Fever focus decreased in amount.

Involvement of CD73, equilibrative nucleoside transporters and inosine in rhythm and conduction disturbances mediated by adenosine A1 and A2A receptors in the developing heart.

We previously established that exogenous adenosine (ADO) induces transient arrhythmias in the developing heart via the adenosine A1 receptor (A1AR) and downstream activation of NADPH oxidase/ERK and PLC/PKC pathways. Here, we investigated the mechanisms by which accumulation of endogenous ADO and its derived compound inosine (INO) in the interstitial compartment induce rhythm and conduction troubles. The validated model of the spontaneously beating heart obtained from 4-day-old chick embryos was used. Quantitative RT-PCR showed that enzymes involved in ADO and INO metabolism (CD39, CD73 and eADA) as well as equilibrative (ENT1, -3, -4) and concentrative (CNT3) nucleoside transporters were differentially expressed in atria, ventricle and outflow tract. Inactivation of ENTs by dipyridamole, 1) increased myocardial ADO level, 2) provoked atrial arrhythmias and atrio-ventricular blocks (AVB) in 70% of the hearts, 3) prolonged P wave and QT interval without altering contractility, and 4) increased ERK2 phosphorylation. Blockade of CD73-mediated phosphohydrolysis of AMP to ADO, MEK/ERK pathway inhibition or A1AR inhibition prevented these arrhythmias. Exposure to exogenous INO also caused atrial ectopy associated with AVB and ERK2 phosphorylation which were prevented by A1AR or A2AAR antagonists exclusively or by MEK/ERK inhibitor. Inhibition of ADA-mediated conversion of ADO to INO increased myocardial ADO and decreased INO as expected, but slightly augmented heart rate variability without provoking AVB. Thus, during cardiogenesis, disturbances of nucleosides metabolism and transport, can lead to interstitial accumulation of ADO and INO and provoke arrhythmias in an autocrine/paracrine manner through A1AR and A2AAR stimulation and ERK2 activation.

HLA photoaffinity labeling reveals overlapping binding of homologous melanoma-associated gene peptides by HLA-A1, HLA-A29, and HLA-B44.

Melanoma-associated genes (MAGEs) encode tumor-specific antigens that can be recognized by CD8+ cytotoxic T lymphocytes. To investigate the interaction of the HLA-A1-restricted MAGE-1 peptide 161-169 (EADPT-GHSY) with HLA class I molecules, photoreactive derivatives were prepared by single amino acid substitution with N beta-[iodo-4-azidosalicyloyl]-L-2,3-diaminopropionic acid. These derivatives were tested for their ability to bind to, and to photoaffinity-label, HLA-A1 on C1R.A1 cells. Only the derivatives containing the photoreactive amino acid in position 1 or 7 fulfilled both criteria. Testing the former derivative on 14 lymphoid cell lines expressing over 44 different HLA class I molecules indicated that it efficiently photoaffinity-labeled not only HLA-A1, but possibility also HLA-A29 and HLA-B44. MAGE peptide binding by HLA-A29 and HLA-B44 was confirmed by photoaffinity labeling with photoreactive MAGE-3 peptide derivatives on C1R.A29 and C1R.B44 cells, respectively. The different photoaffinity labeling systems were used to access the ability of the homologous peptides derived from MAGE-1, -2, -3, -4a, -4b, -6, and -12 to bind to HLA-A1, HLA-A29, and HLA-B44. All but the MAGE-2 and MAGE-12 nonapeptides efficiently inhibited photoaffinity labeling of HLA-A1, which is in agreement with the known HLA-A1 peptide-binding motif (acidic residue in P3 and C-terminal tyrosine). In contrast, photoaffinity labeling of HLA-A29 was efficiently inhibited by these as well as by the MAGE-3 and MAGE-6 nonapeptides. Finally, the HLA-B44 photoaffinity labeling, unlike the HLA-A1 and HLA-A29 labeling, was inhibited more efficiently by the corresponding MAGE decapeptides, which is consistent with the reported HLA-B44 peptide-binding motif (glutamic acid in P2, and C-terminal tyrosine or phenylalanine). The overlapping binding of homologous MAGE peptides by HLA-A1, A29, and B44 is based on different binding principles and may have implications for immunotherapy of MAGE-positive tumors.

Antimicrobial susceptibility, phage types, and pulsetypes of Salmonella Typhimurium, in São Paulo, Brazil

A total of 283 Salmonella Typhimurium strains isolated from cases of human infections and non human sources, were examined for antimicrobial susceptibilityand the incidence of resistance was 38% and multiple resistance (to three or more antimicrobials) was 15%. All 43 multidrug-resistant strains (MDR) and 13 susceptible ones were characterized by phage typing and pulsed- field gel electrophoresis (PFGE). The strains encompassed 14 definitive phage types (DT), three were untypable (UT), and 18 atypicals or reaction does not conform (RDNC), which belonged to 21 PFGE patterns, A1-A21. The predominant phage types were DT49, DT193, and RDNC and two strains belonging to DT 104 and 104b were also identified. The most commum PFGE patterns were A1 and A8. Analysis by PFGE and phage typing demonstrated that the most of the MDR were multiclonal and association among multiresistance, phage typing, and PFGE patterns was not so significant.

Implantació en SAP R/3 de la fusió per absorció impròpia en les societats 'A1' i 'A2'

En el context actual sovint tenen lloc operacions juridicofinanceres de gran envergadura entre empreses del mateix grup, especialment en determinats sectors de l'economia. Aquestes operacions comporten la integració dels sistemes d'informació de les societats que s'hi troben afectades. El cas que ens ocupa fa referència a una operació de fusió per absorció de dues societats que pertanyen al mateix grup. Totes dues gestionen la seva activitat fent servir el sistema d'informació SAP/R3.

Caractéristiques cliniques des leucémies lymphoblastiques aiguës de type T immature (E-rosette négatif) détecté par l'anticorps monoclonal LAU-A1 [Clinical characteristics of immature T-type (negative E-rosette) acute lymphoblastic leukemia detected by LAU-A1 monoclonal antibody]

Immature T-ALL is a newly defined subgroup of ALL in which the blasts lack the receptor for sheep erythrocytes (ER) and the usual T-cell markers, but express the 40 kDa pan-T surface antigen recognized by our monoclonal antibody LAU-A1. Patients with immature T-ALL represent 10% of all cases of adult ALL. Leukocyte counts are lower and spleen, liver and lymph node enlargement is less prominent, but mediastinal enlargement is more frequent than in mature (ER-positive) T-ALL. 7 patients with immature T-ALL (median age 42 years, range 13-73) were treated with intensified chemotherapy regimens, and only one 47-year-old female entered a short-lived complete remission. The overall survival of our patients was poor (median 7.5 months, with only one patient surviving at 15 months) and seemed not to be influenced by age. Our study indicates that immature T-ALL can only be accurately identified by the use of monoclonal antibodies recognizing the 40 kDa pan-T antigen, and that immature T-ALL is a separate disease entity typified by a poor prognosis.

Fantaisie en ut mineur, K 475 / Mozart, comp. ; revue et annotée par Lazare-Lévy ; Lazare-Lévy, p

Titre uniforme : [Fantaisies. Piano. KV 475. Do mineur]

Renal effects of adenosine A1-receptor blockade with 8-cyclopentyl-1,3-dipropylxanthine in hypoxemic newborn rabbits.

The key role of intrarenal adenosine in mediating the hypoxemic acute renal insufficiency in newborn rabbits has been well demonstrated using the nonspecific adenosine antagonist theophylline. The present study was designed to define the role of adenosine A1 receptors during systemic hypoxemia by using the specific A1-receptor antagonist 8-cyclopentyl-1,3-dipropylxanthine (DPCPX). Renal function parameters were assessed in 31 anesthetized and mechanically ventilated newborn rabbits. In normoxia, DPCPX infusion induced a significant increase in diuresis (+44%) and GFR (+19%), despite a significant decrease in renal blood flow (RBF) (-22%) and an increase in renal vascular resistance (RVR) (+37%). In hypoxemic conditions, diuresis (-19%), GFR (-26%), and RBF (-35%) were decreased, whereas RVR increased (+33%). DPCPX administration hindered the hypoxemia-induced decrease in GFR and diuresis. However, RBF was still significantly decreased (-27%), whereas RVR increased (+22%). In all groups, the filtration fraction increased significantly. The overall results support the hypothesis that, in physiologic conditions, intrarenal adenosine plays a key role in regulating glomerular filtration in the neonatal period through preferential A1-mediated afferent vasoconstriction. During a hypoxemic stress, the A1-specific antagonist DPCPX only partially prevented the hypoxemia-induced changes, as illustrated by the elevated RVR and drop in RBF. These findings imply that the contribution of intrarenal adenosine to the acute adverse effects of hypoxemia might not be solely mediated via the A1 receptor.

A nonapeptide encoded by human gene MAGE-1 is recognized on HLA-A1 by cytolytic T lymphocytes directed against tumor antigen MZ2-E.

We have reported the identification of human gene MAGE-1, which directs the expression of an antigen recognized on a melanoma by autologous cytolytic T lymphocytes (CTL). We show here that CTL directed against this antigen, which was named MZ2-E, recognize a nonapeptide encoded by the third exon of gene MAGE-1. The CTL also recognize this peptide when it is presented by mouse cells transfected with an HLA-A1 gene, confirming the association of antigen MZ2-E with the HLA-A1 molecule. Other members of the MAGE gene family do not code for the same peptide, suggesting that only MAGE-1 produces the antigen recognized by the anti-MZ2-E CTL. Our results open the possibility of immunizing HLA-A1 patients whose tumor expresses MAGE-1 either with the antigenic peptide or with autologous antigen-presenting cells pulsed with the peptide.