Effectiveness of internet-based cognitive behaviour therapy for panic disorder in routine psychiatric care

OBJECTIVE

Guided Internet-based cognitive behaviour therapy (ICBT) for panic disorder has been shown to be efficacious in several randomized controlled trials. However, the effectiveness of the treatment when delivered within routine psychiatric care has not been studied. The aim of this study was to investigate the effectiveness of ICBT for panic disorder within the context of routine psychiatric care.

METHOD

We conducted a cohort study investigating all patients (n = 570) who had received guided ICBT for panic disorder between 2007 and 2012 in a routine care setting at an out-patient psychiatric clinic providing Internet-based treatment. The primary outcome measure was the Panic Disorder Severity Scale-Self-report (PDSS-SR).

RESULTS

Participants made large improvements from screening and pretreatment assessments to posttreatment (Cohen's d range on the PDSS-SR = 1.07-1.55). Improvements were sustained at 6-month follow-up.

CONCLUSION

This study suggests that ICBT for panic disorder is as effective when delivered in a routine care context as in the previously published randomized controlled trials.

A role for tissue transglutaminase in alpha-gliadin peptide cytotoxicity

In coeliac disease, gliadin peptides p56-88, p57-68 and p31-49 have been demonstrated to be involved in the pathogenic damage of the small intestine via their immunogenicity or toxicity to epithelial cells. To try to understand the mechanism of their toxicity, we investigated the effect of synthetic peptides (p31-49, p56-88, p57-68, p69-82) and of their deamidated analogues on Caco2 and FHs 74 Int cell toxicity and tissue tranglutaminase activity. Apoptosis, necrosis and cell viability were assessed by flow cytometry, and peptide deamidation was determined indirectly by measuring its capacity to inhibit tTG activity. The results showed that p56-88 and p57-68 reduced cell growth and concomitantly inhibited tTG activity in both cell types. This effect was abolished when Caco2 cells were treated with antibodies to tTG. Deamidated peptide p57-68 (E(65)) lost practically all of its inhibitory effect on cell growth and on tTG activity. Cellular toxicity was also observed with p31-49, which was not a substrate for tTG. p69-82 was not cytotoxic but became so when glutamine 72 was substituted by glutamic acid. These findings provide evidence for the existence of three types of toxicity among gliadin peptides: (i) peptides that are intrinsically toxic and are not substrates of tTG; (ii) peptides that are non-toxic but become so when they act as substrates of tTG; and (iii) peptides that are non-toxic and are not substrates of tTG but become so when deamidated. A mechanism other than that involving tTG could be responsible for the deamidation of glutamine residues of gliadin in the intestinal tract.

Development of an immunocapture method for measuring IgA antibodies to tissue transglutaminase in the sera of patients with coeliac disease

One of the most reliable sero-diagnostic tests for coeliac disease (CD) is the measurement, by ELISA, of serum IgA antibodies to tissue transglutaminase (tTG) adsorbed to the wells of microtitre plates. In spite of its reliability, however, some discrepancies exist with the results obtained by the antiendomysium histological assay (EMA) and by biopsy the accepted gold standard. Among the reasons for these differences in titres between the ELISA and the last 2 mentioned assays are the conformational changes that proteins undergo on adsorption and the importance of conformational epitopes on tTG for diagnosing CD. To address this problem, a novel procedure was developed using guinea-pig tTG (gptTG) free in solution to interact with IgA antibodies in the sera of CD patients. Any immune complexes so formed are then captured by anti-tTG antibodies preadsorbed to the wells of microtitre plates. This immunocapture method was optimized for the amount of soluble gptTG needed to interact with all the IgA's anti-tTG present in fixed dilutions of serum samples, the amount of rabbit IgG anti-gptTG used to coat the wells of microtitre plates and the order of addition of the reaction components. Comparison of the IgA titres obtained by immunocapture with those by EMA and ELISA (adsorbed tTG) on 9 highly positive and 6 weakly positive sera from clinically characterized CD patients and 5 negative sera from non-CD control subjects revealed that the IgA titres by the immunocapture procedure were well correlated with those obtained by EMA, whereas the titres on ELISA showed discrepancies with both immunocapture and EMA.

Regulation of glutamine synthetase by metal-catalyzed oxidative modification in the marine oxyphotobacterium Prochlorococcus

The inactivation of glutamine synthetase (GS; EC 6.3.1.2) by metal-catalyzed oxidation (MCO) systems was studied in several Prochlorococcus strains, including the axenic PCC 9511. GS was inactivated in the presence of various oxidative systems, either enzymatic (as NAD(P)H+NAD(P)H-oxidase+Fe(3+)+O(2)) or non-enzymatic (as ascorbate+Fe(3+)+O(2)). This process required the presence of oxygen and a metal cation, and is prevented under anaerobic conditions. Catalase and peroxidase, but not superoxide dismutase, effectively protected the enzyme against inactivation, suggesting that hydrogen peroxide mediates this mechanism, although it is not directly responsible for the reaction. Addition of azide (an inhibitor of both catalase and peroxidase) to the MCO systems enhanced the inactivation. Different thiols induced the inactivation of the enzyme, even in the absence of added metals. However, this inactivation could not be reverted by addition of strong oxidants, as hydrogen peroxide or oxidized glutathione. After studying the effect of addition of the physiological substrates and products of GS on the inactivation mechanism, we could detect a protective effect in the case of inorganic phosphate and glutamine. Immunochemical determinations showed that the concentration of GS protein significantly decreased by effect of the MCO systems, indicating that inactivation precedes the degradation of the enzyme.

Transglutaminase-mediated cross-linking is involved in the stabilization of extracellular matrix in human liver fibrosis

BACKGROUND/AIMS

Lysyl oxidase-mediated cross-linking contributes to the stabilization of collagen in liver fibrosis. We have investigated transglutaminase-mediated cross-linking, to determine if it participates in the stabilization of extracellular matrix in human liver fibrosis.

METHODS

Transglutaminase activity was assessed in vitro by incorporation of biotinylated amine into liver proteins. The product of the transglutaminase-catalyzed cross-linking reaction, Nepsilon(gamma-glutamyl)lysine, and the extracellular proteins cross-linked by it, were localized by immunohistochemistry in fibrotic livers. The cross-linked complexes were extracted from liver tissue, immunopurified and characterized by Western blot.

RESULTS

Transglutaminase, detected by immunohistochemistry, Western blot and by enzymatic activity, was found in higher amounts in fibrotic than in normal liver. The Nepsilon(gamma-glutamyl)lysine cross-link, undetectable in normal liver, was present extracellularly in fibrotic liver, where it was co-distributed with osteonectin, mostly in inflammatory areas submitted to an intense remodeling. Cross-linking of osteonectin by transglutaminase was confirmed by Western blot. In parasitic fibrosis transglutaminase also originates from the parasite.

CONCLUSIONS

Transglutaminase-mediated cross-linking occurs in liver extracellular matrix during the early, inflammatory, stage of liver fibrosis, whereas cross-linking by pyridinoline occurs mostly later in the fibrotic process. This could lead to the development of new anti-fibrotic treatments targeted to a specific stage of fibrosis.

In vivo regulation of glutamine synthetase activity in the marine chlorophyll b-containing cyanobacterium Prochlorococcus sp. strain PCC 9511 (oxyphotobacteria)

The physiological regulation of glutamine synthetase (GS; EC 6.3.1.2) in the axenic Prochlorococcus sp. strain PCC 9511 was studied. GS activity and antigen concentration were measured using the transferase and biosynthetic assays and the electroimmunoassay, respectively. GS activity decreased when cells were subjected to nitrogen starvation or cultured with oxidized nitrogen sources, which proved to be nonusable for Prochlorococcus growth. The GS activity in cultures subjected to long-term phosphorus starvation was lower than that in equivalent nitrogen-starved cultures. Azaserine, an inhibitor of glutamate synthase, provoked an increase in enzymatic activity, suggesting that glutamine is not involved in GS regulation. Darkness did not affect GS activity significantly, while the addition of diuron provoked GS inactivation. GS protein determination showed that azaserine induces an increase in the concentration of the enzyme. The unusual responses to darkness and nitrogen starvation could reflect adaptation mechanisms of Prochlorococcus for coping with a light- and nutrient-limited environment.

A novel covalent enzyme-linked immunoassay (CELIA) for simultaneously measuring free and immune complex bound antibodies with a defined specificity. II. Application to immune complexes containing viral antigens in human sera

The coupling of viral antigens from parainfluenza virus (PIV-1), cytomegalovirus (CMV) and human immunodeficiency virus (HIV-1) to chemically functionalized polystyrene plates has permitted us to develop a covalent enzyme-linked immunoassay (CELIA) for measuring the titers of free antibody (Ab) and immune complex (IC) bound Ab directed against each of these viruses. The method was first validated for experimentally produced IC (PIV-anti-PIV) and then applied to the analysis of IC in human sera. In the case of a renal transplant patient with CMV viremia whose free Ab titers were less than 100, the method unambiguously permitted the IC bound anti-CMV titers to be determined. In the case of a survey for HIV-1 Ab, it also allowed us to identify a sub-group of seropositives with IC anti-HIV. In view of the ease and rapidity with which CELIA can be performed, this technology should enable determinations of IC bound Ab of defined specificity to be undertaken routinely in seroepidemiological surveys.