Effect of process parameters and surfactant additives on the obtained activity of recombinant tryptophan hydroxylase (TPH1) for enzymatic synthesis of 5-hydroxytryptophan (5-HTP).

5-hydroxytryptophan (5-HTP) is an intermediate molecule in the biosynthesis of serotonin, an important neurotransmitter, regulating a series of metabolic and psychological functions in humans. In this work, we studied the heterologous production of Human tryptophan hydroxylase (TPH1) in Escherichia coli, for the synthesis of 5-hydroxytryptophan (5-HTP) from Tryptophan (Trp). To quantify TPH1 activity, a simple fluorescence-based microtiter plate assay was established, based on the changes in fluorescence emission at 340 nm between substrate and product when excited at 310 nm, allowing quick and reliable quantification of released 5-HTP.

A simple rule to personalize standard dual therapy across all genotypes in naive chronic hepatitis C patients: the TT4 randomized trial.

Background: Rapid and early virological responses to peginterferon-alpha and ribavirin are predictive of sustained virological response (SVR) in hepatitis C virus (HCV) infection. We aimed at finding a simple rule to determine the shortest duration of dual therapy for all HCV genotypes, obtained by multiplying time to Initial Viral Response, IVR (first undetectable HCV-RNA) by 4 (Tailored Therapy-4, or TT4).

Method: 267 naïve HCV-infected patients with compensated liver disease were randomized (2:1) to the TT4 (n=180) or current standard-of-care (SoC, n=87) and received peginterferon-alpha plus ribavirin.

North Western Spain hot springs are a source of lipolytic enzyme-producing thermophilic microorganisms.

Several hot springs in Galicia (North Western Spain) have been investigated as potential sources of lipolytic enzyme-producing thermophilic microorganisms. After isolating 12 esterase producing strains, 9 of them were assured to be true lipase producers, and consequently grown in submerged cultures, obtaining high extracellular activities by two of them. Furthermore, a preliminary partial characterization of the crude lipase, obtained by ultrafiltration of the cell-free culture supernatant, was carried out at several pH and temperature values.

Scaling-up the production of thermostable lipolytic enzymes from Thermus aquaticus YT1.

The lipolytic enzymes synthesized by Thermusaquaticus YT1 present extremely interesting properties of thermostability (more than 70% of activity after 12 days at 80°C and a half-life time of 1 h at 95°C), which point out the interest of proposing efficient strategies to successfully tackle the scale-up of the production process. In this study,viable scaling-up of the production process was implemented,and relevant aspects affecting the enzyme synthesis, such as the mineral composition of the culture medium, the aeration and the agitation have been evaluated.A strategy combining the modification of the culture medium and the aeration degree was also approached by adding perfluorocarbons, compounds which improve the availability of oxygen in the culture medium.

A process for extracellular thermostable lipase production by a novel Bacillus thermoamylovorans strain.

A lipolytic enzyme-producing thermophilic microorganism, recently isolated from a hot spring in Galicia (North Western Spain), has been investigated. First, the strain was genetically identified and tentatively named Bacillus thermoamylovorans CH6B. It produced significant levels (around 450 U/L) of extracellular lipolytic activity in shake flask cultures, and the most suitable conditions for this biological process were found at temperatures between 50 and 55 °C, and an initial pH value around 7.

Studies of laccase from Trametes versicolor in aqueous solutions of several methylimidazolium ionic liquids.

Stability and kinetic behavior of laccase from Trametes versicolor in the presence of several ionic liquids from the methylimidazolium family have been investigated. In general laccase stability diminished as the size of the alkylic substitute in the methylimidazolium ring increased. Higher concentrations of ionic liquids caused more destabilization than lower ones.

Hepatitis C virus production requires apolipoprotein A-I and affects its association with nascent low-density lipoproteins.

Background/aims: The life cycle of hepatitis C virus (HCV) is intimately linked to the lipid metabolism of the host. In particular, HCV exploits the metabolic machinery of the lipoproteins in several steps of its life cycle such as circulation in the bloodstream, cell attachment and entry, assembly and release of viral particles. However, the details of how HCV interacts with and influences the metabolism of the host lipoproteins are not well understood.

A copper(II) thiosemicarbazone complex built on gold for the immobilization of lipase and laccase.

A self-assembled monolayer (SAM) of imidazole-2-carbaldehyde thiosemicarbazone (H(2)ImTSC) on gold was formed and characterized by ATR-FTIR, Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) and X-ray Photoelectron Spectroscopy (XPS). The self-assembly of the ligand through its thioenolate group was confirmed by ToF-SIMS and the presence of XPS peaks at 161.9 (S(2p1/2)) and 163.

Strategies for utilisation of food-processing wastes to produce lipases in solid-state cultures of Rhizopus oryzae.

The aim of the present study was to investigate the feasibility of several food-processing wastes as support substrate for lipolytic enzymes production by the fungus Rhizopus oryzae under solid-state conditions. Different experiments were conducted to select the variables that allow obtaining high levels of lipolytic enzyme activity. In particular, the use of inert and non-inert solid materials and lipidic and surfactant compounds was evaluated.

Patterns of chronic hepatitis B in Central Italy: a cross-sectional study.

We investigated the patterns of chronic hepatitis B virus (HBV)-related disease in a large cohort of HBsAg-positive patients, in Central Italy, by collecting a screening form with demographic, clinical and laboratory data. Overall, 737 HBsAg-positive cases were included (70% male; median age 52 years): 30% were inactive HBsAg carriers, 51% had chronic hepatitis B (CHB) and 19% had HBV-related cirrhosis. Patients from non-European Union (EU) countries (n = 65) were significantly younger, had a higher prevalence of HBeAg-positive infection and hepatitis delta virus (HDV) co-infection than patients of Italian origin.

Thermostable lipolytic enzymes production in batch and continuous cultures of Thermus thermophilus HB27.

Several studies in laboratory-scale bioreactors are undertaken in order to verify the beneficial effect of thermal spring water in the culture medium of Thermus thermophilus HB27. Two bioreactor configurations, stirred tank and airlift, are investigated to determine the most suitable one to develop a continuous process. Water mineral composition affects the lipolytic enzyme secretion and growth of T.

Strategies for improving extracellular lipolytic enzyme production by Thermus thermophilus HB27.

In Thermus thermophilus HB27 cultures the localisation of lipolytic activity is extracellular, intracellular and membrane bound, with low percentage for the former. Therefore, the extracellular secretion must be increased in order to simplify the downstream process and to reduce the economic cost. This study focuses on the design of an innovative operational strategy to increase extracellular lipolytic enzyme production by T.

Hydrogen peroxide biosensor with a supramolecular layer-by-layer design.

A new sensor design is reported for the construction of an amperometric enzyme biosensor toward H (2)O(2). It was based in the supramolecular immobilization of alternating layers of horseradish peroxidase (either modified with 1-adamantane or beta-cyclodextrin-branched carboxymethylcellulose residues) on Au electrodes coated with polythiolated beta-cyclodextrin polymer. The analytical response of the electrodes, using 1 mM hydroquinone as an electrochemical mediator, increases when the number of enzyme layers increases.

Impact of hepatitis C virus infection on lifestyle.

Aim: To evaluate the impact of the diagnosis of hepatitis C infection on lifestyle habits such as smoking, drinking, sports activity and diet.

Methods: A self-administered, anonymous questionnaire was offered to out-patients with HCV infection consecutively attending three clinical centres in Italy.

Results: Of the 275 respondents, 62.

The effect of age on response to therapy with peginterferon alpha plus ribavirin in a cohort of patients with chronic HCV hepatitis including subjects older than 65 yr.

Objectives: In many industrialized countries HCV infection is characterized by an increasing prevalence during ageing; however, data on the efficacy of treatment among older patients are scarce. This study was set up to evaluate the effect of age on the treatment of chronic HCV hepatitis with peginterferon alpha plus ribavirin.

Methods: We retrospectively reviewed medical records of 153 adult patients with chronic HCV hepatitis treated with combination therapy; 30 of them (19.

Accumulation of dysfunctional effector CD8+ T cells in the liver of patients with chronic HCV infection.

Background/aims: Hepatitis C virus (HCV) causes a chronic infection that can lead to fibrosis and carcinoma. Immune responses mediated by cytotoxic T lymphocytes (CTLs) could be involved in viral clearance or persistence, and therefore in determining the course of the disease.

Methods: Intrahepatic and peripheral blood CD8+T cells were obtained from 32 HCV-chronically infected patients and analysed by flow-cytometry for surface markers of differentiation, IFNgamma and TNFalpha production, degranulation capacity and perforin content, after CD3 triggering.

Production of thermostable lipolytic activity by thermus species.

A quantitative screening for intra- and extracellular lipolytic activity was performed in submerged cultures of four Thermus strains using two different media (named T or D medium). Major differences in the extracellular lipolytic activity were observed in T medium, the highest values being for Thermus thermophilus HB27 and Thermus aquaticus YT1 strains (18 and 33 U/L, respectively). Two enzymes with lipase/esterase activity were identified in the four Thermus strains by zymogram analysis, with molecular weights of 34 and 62 kDa.

Ultrastructural study of the pancreas in AIDS.

Introduction: Frequent histologic changes (90%) in the pancreas suggesting protein-energy malnutrition were found in a previous necropsy study of pancreas morphology in patients with AIDS. However, additional studies were required to clarify subcellular changes.

Aim: To ultrastructurally analyze pancreas changes in AIDS patients through transmission electron microscopy.