CHARACTERIZATION OF THE HEPATITIS-B VIRUS PRES/S REGION ENCODED TRANSCRIPTIONAL TRANSACTIVATOR

A transactivating function generated by carboxy-terminal truncation of the HBV envelope proteins has been recently described. To characterize the preS/S protein domains responsible for transactivation, preS1/S2/S and preS2/S 3′ deletion mutants under the control of the adenoviral major late promoter were tested for their transactivating potential in cotransfection experiments using the c-myc and c-fos regulatory sequences as targets. Deletion of the carboxyterminal hydrophobic domain of the S protein and the presence of the endoplasmic reticulum insertion signal I (ER signal I) are required for the generation of the preS/S transactivating function. Multiple transcription factors binding sites (i.e., TRE, SIRE, and NFkB sites) mediated the truncated preS/S-induced activation of the target regulatory sequences. The transactivation phenomenon is linked, at least in part, to the protein kinase C signaling pathway. © 1992

Preliminary evaluation of the new TACR flex method versus MEIA method in the therapeutic monitoring of tacrolimus in organ transplantation

Tacrolimus (FK506) is an effective macrolide immunosuppressant widely used to prevent organ rejection following transplantation. Monitoring blood levels of tacrolimus is essential to assess organ rejection versus toxicity, because of the narrow therapeutic range and pharmacokinetic variability. The increased request for therapeutic drug monitoring is an interesting challenge for clinical laboratories. The automated immunoassay methods provide correct results and a turnaround time considerably reduced compared to HPLC and HPLC-MS which remain the gold standard for accuracy and economical advantages. A new immunoassay method, TACR Flex Dimension, is a commercially available, automated pretreatment test. The purpose of this study was to compare two analytical methods: the MEIA 11 tacrolimus immunoassay using the lMx analyzer and the new TACR Flex tacrolimus immunoassay on the Dimension system. Tacrolimus results obtained using the two methods were compared using European control and 93 whole blood samples from kidney and liver transplant patients. The tacrolimus concentrations measured by Flex Dimension for all samples were higher (0.7 to 16.1 ng/mL) than results obtained with MEIA (0.2 to 13.4 ng/mL), a mean difference expressed in percentage of 31.7%, and a correlation coefficient of 0.85. The data obtained by both methods using three European controls showed similar concentrations. The TACR Flex Dimension method provided a higher automation level and therefore a lower incidence of preanalytical errors and a lower turnaround time

REACTIVE OXYGEN INTERMEDIATES (ROIS) ARE INVOLVED IN THE INTRACELLULAR TRANSDUCTION OF ANGIOTENSIN-II SIGNAL IN C2C12 CELLS

Increasing evidence suggests that angiotensin II may act as a growth factor for several muscle cell types. Angiotensin II stimulation activates many immediate early response genes like c-Fos, c-Jun, c-Myc and Egr-1 in both vascular smooth muscle cells and cardiomyocytes, independently of whether a hyperplastic or hypertrophic response is taking place. In this study we report that angiotensin II significantly stimulates AP1-driven transcription in mouse skeletal muscle cells C2C12 stably transfected with a TRE-tk-CAT plasmid in a dose-dependent manner (peak stimulation at 10-5 M of angiotensin II). Moreover, angiotensin II increases the binding of the AP1 complex to its DNA target in both quiescent C2C12 myoblasts and in differentiated C2C12 myotubes. Most of the TRE-bound complexes in both unstimulated and angiotensin II-treated cells consist of c-jun/c-fos heterodimers. Using a set of different protein kinase inhibitors, including HA1004, H7, tyrphostin, genistein and staurosporine, we could demonstrate that the angiotensin II-induced AP1 binding increase is not mediated by the cAMP-dependent pathway and that protein kinase C and tyrosine kinases are involved. Treatment of C2C12 cells with H2O2 induces a dose-dependent increase in c-jun/c-fos heterodimer binding, specifically reverted by the cysteine derivative and glutathione precursor N-acetyl-L-cysteine (NAC). The observation that the induction by angiotensin II of both the AP1 DNA binding activity and DNA synthesis in quiescent C2C12 myoblasts is abolished by NAC strongly suggests a role for reactive oxygen intermediates (ROIs) in the intracellular transduction of angiotensin II signals for immediate early gene induction and for cell proliferation

Copeptin kinetics in acute ischemic stroke may differ according to revascularization strategies: pilot data

Background and Purpose- Prognostic value of copeptin in acute ischemic stroke has been widely reported. This study aimed to evaluate copeptin temporal profile according to revascularization strategies and the development of brain edema and hemorrhagic transformation. Methods- Plasma copeptin and brain edema and hemorrhagic transformation assessed by computed tomography/magnetic resonance imaging were evaluated upon admission (T0), at 24 hours (T1), and between the third and fifth day of hospitalization (T2) in 34 acute ischemic stroke patients. Results- Median copeptin concentration was 50.71 pmol/L at T0, 18.31 pmol/L at T1, and 10.92 pmol/L at T2. Copeptin at T1 was higher in patients with medium/severe brain edema at T2 (32.25 versus 13.67 pmol/L; P=0.038) and hemorrhagic transformation at T1 (93.10 versus 13.67 pmol/L; P<0.003) and T2 (85.70 versus 14.45 pmol/L; P=0.024). Copeptin level drop (CopΔT1-T0) was significantly steeper in patients receiving revascularization, particularly in those undergoing combined therapy (-129.34 versus -5.43 pmol/L; P=0.038). ΔT1-T0 also correlated with Thrombolysis in Cerebral Infarction score (P<0.001). Conclusions- Copeptin resulted associated with brain edema and hemorrhagic transformation in acute ischemic stroke, and its drop at 24 hours may mirror effective brain vessel recanalizatio

PRESEPSIN AS A POTENTIAL MARKER FOR BACTERIAL INFECTION RELAPSE IN CRITICAL CARE PATIENTS. A PRELIMINARY STUDY

Background: Systemic bacterial infection carries a high risk of mortality in critical care patients. Improvements in diagnostic procedures are required for effective management of sepsis. Recently, the soluble CD14 subtype, or presepsin, has been suggested as a reliable marker of sepsis, and we set out to compare its diagnostic performance with that of procalcitonin (PCT). We focused on a cohort of septic patients who, during their hospitalization, relapsed after a period of clinical relief from symptoms. Methods: In total 21 adult patients were studied during their hospitalization in the Critical Care Unit of Policlinico Umberto I hospital; 74 plasma samples were collected at multiple time points, and presepsin levels were measured using a PATHFAST® analyzer. Results: Presepsin and PCT were significantly lower in healthy controls than in sepsis or severe sepsis (p1000 pg/mL) remained high. Conclusions: This study confirms the importance of monitoring a combination of several biomarkers in order to obtain a reliable diagnosis. Maximal presepsin levels could alert clinicians not to suspend antibiotic treatments and to carefully monitor septic patients’ state of health, even after clinical symptoms have disappeared and PCT levels returned to normal