Improving access to psychological therapies (IAPT) and treatment outcomes: epistemological assumptions and controversies.

Cognitive behaviour therapy (CBT) is recommended as a primary treatment choice in England, for anxiety and depression, by the National Institute for Health and Care Excellence (NICE). It has been argued that CBT has enjoyed political and cultural dominance and this has arguably led to maintained government investment in England for the cognitive and behavioural treatment of mental health problems. The government programme 'Improving Access to Psychological Therapies' (IAPT) aims to improve the availability of CBT. The criticism of the NICE evidence-based guidelines supporting the IAPT programme, has been the dominance of the gold standard randomized controlled trial methodology, with a focus on numerical outcome data, rather than a focus on a recovery narrative. RCT-based research is influenced by a philosophical paradigm called positivism. The IAPT culture is arguably influenced by one research paradigm and such an influence can skew services only towards numerical outcome data as the only truth of 'recovery'. An interpretative paradigm could assist in shaping service-based cultures, alter how services are evaluated and improve the richness of CBT research. This paper explores the theory of knowledge (epistemology) that underpins the evidence-based perspective of CBT and how this influences service delivery. The paper argues that the inclusion of service user narrative (qualitative data) can assist the evaluation of CBT from the user's perspective and can understand the context in which people live and how they access services. A qualitative perspective is discussed as a research strategy, capturing the lived experience of under-represented groups, such as sexual, gender and ethnic minorities. Cognitive behaviour therapy (CBT) has enjoyed political and cultural dominance within mental healthcare, with renewed government investment in England for the'Improving Access to Psychological Therapies' (IAPT) programme. The criticism of the evidence-based guidelines, published by the National Institute for Health and Care Excellence (NICE), which supports the IAPT programme has been the dominance of the gold standard randomized controlled trial methodology. The definition of 'recovery' used by IAPT is based on a positivist position, with a focus on numerical outcome data garnered through psychometric measures. An interpretative perspective of recovery, which would include a subjective individual patient/service user narrative and would include a collaborative qualitative dialogue, is arguably absent from the IAPT programme. The challenge inherent in the IAPT programme is the high demand/high turnover culture, and psychometric measures are quick to administer; however, this culture is driven from one research paradigm. An interpretative paradigm may assist in shaping service-based cultures, alter how services are evaluated, and improve the richness of CBT research.

Dietary shifts affect the gastrointestinal microflora of the giant panda (Ailuropoda melanoleuca).

Giant pandas exhibit seasonal changes in bamboo plant part preference. The influences on the gastrointestinal tracts (GIT) microbial populations were evaluated during a 14-month period for a pair of adult male and female giant pandas housed at the Memphis Zoo using traditional culturing methods to enumerate eight bacterial groups (total anaerobes, total aerobes (TAR), streptococci (STR), total enterics, Escherichia coli, Bacteroides spp., lactobacilli and Clostridium spp.). Both the male and female pandas altered bamboo consumption behaviours, with a sharp decrease in leaf preference in April 2010 and returning to high levels of leaf preference from June to October, corresponding to significant shifts in the densities of TAR, STR, and lactobacilli and Bacteroides spp. These findings indicate seasonal changes in food preference affect the assemblages of microbial populations within the GIT of the giant panda and contribute to a better understanding of the importance of bamboo in this species' foraging strategy.

Cognitive behaviour therapy within assertive outreach teams: barriers to implementation: a qualitative peer audit.

Assertive outreach is an evidence-based intervention, with over 30 well-designed randomized studies demonstrating its effectiveness, predominately in the USA. Assertive outreach teams have recently been implemented in the UK, and it has been recommended that teams should offer cognitive behaviour therapy (CBT) to service users; however, it has been reported that barriers exist in the routine delivery of CBT for psychosis (CBTp). The aim of the peer audit was to gauge current opinion from clinicians whether their experiences of barriers to implementation of CBTp reflected that outlined in the literature. A qualitative peer audit was undertaken at the National Forum for Assertive Outreach Annual Conference in 2006. The team representatives were invited to outline the barriers to the implementation of psychosocial interventions within their local areas. Teams identified organizational, managerial, supervision and local specific barriers to implementation. Specific comments included a lack of organizational investment, the structured nature of CBT, caseload issues, medication issues, application to people with sensory impairments, staff apathy and staff burnout. The analysis was limited by the metholodology employed; however, further recommendations are explored. It was evident from this peer audit that teams are experiencing barriers relating to the implementation of evidence-based therapy interventions and further research is required on the outreach model and the use of CBTp.

Widespread recombination within human parechoviruses: analysis of temporal dynamics and constraints.

Human parechoviruses (HPeVs), members of the family Picornaviridae, are classified into six types. To investigate the dynamics and likelihood of recombination among HPeVs, we compared phylogenies of two distant regions (VP1 and 3Dpol) of 37 HPeV isolates (types 1 and 3-5) and prototype sequences (types 1-6). Evidence for frequent recombination between HPeV1, 4, 5 and 6 was found. The likelihood of recombination was correlated with the degree of VP1 divergence and differences in isolation dates, both indicative of evolutionary times of divergence. These temporal dynamics were found to be most similar to those of human enterovirus species B variants. In contrast, HPeV3 remained phylogenetically distinct from other types throughout the genome. As HPeV3 is equally divergent in nucleotide sequence from the other HPeV types, its genetic isolation may reflect different biology and changed cellular tropisms, arising from the deletion of the RGD motif, and likely use of a non-integrin receptor.

Specific inhibitors of Plasmodium falciparum thioredoxin reductase as potential antimalarial agents.

Plasmodium falciparum thioredoxin reductase (PfTrxR: NADPH+Trx(S)2+H+<-->NADP++Trx(SH)2) is a high Mr flavin-dependent TrxR that reduces thioredoxin (Trx) via a CysXXXXCys pair located penultimately to the C-terminal Gly. In this respect, PfTrxR differs significantly from its human counterpart which bears a Cys-Sec redox pair at the same position. PfTrxR is essentially involved in antioxidant defense and redox regulation of the parasite and has been previously validated by knock-out studies as a potential drug target for malaria chemotherapy. Moreover, human TrxR is present in most cancer cells at levels tenfold higher than in normal cells. Here we report the discovery of a series of potent inhibitors of PfTrxR. The three most promising inhibitors, 3(IC50(PfTrxR)=2 microM and IC50(hTrxR)=50 microM), 7(IC50(PfTrxR)=2 microM and IC50(hTrxR)=140 microM), and 11(IC50(PfTrxR)=0.5 microM and IC50(hTrxR)=4 microM) were selective for the parasite enzyme. Detailed mechanistic characterization of the effects of these compounds on the PfTrxR-catalyzed reaction showed clear uncompetitive inhibition with respect to both substrate and cofactor. For the most specific PfTrxR inhibitor 7, an alkylation mechanism study based on a thiol conjugation model was performed. Furthermore, all three compounds were active in the lower micromolar range on the chloroquine-resistant P. falciparum strain K1 in vitro.

Field and laboratory comparative evaluation of ten rapid malaria diagnostic tests.

The paper reports on a comparative evaluation of 10 rapid malaria tests available in South Africa in 1998: AccuCheck (AC, developmental), Cape Biotech (CB), ICT Malaria Pf (ICT1) and Pf/Pv (ICT2), Kat Medical (KAT), MakroMal (MM), OptiMAL (OP), ParaSight-F (PS), Quorum (Q), Determine-Malaria (DM). In a laboratory study, designed to test absolute detection limits, Plasmodium falciparum-infected blood was diluted with uninfected blood to known parasite concentrations ranging from 500 to 0.1 parasites per microlitre (P/microL). The 50% detection limits were: ICT1, 3.28; ICT2, 4.86; KAT, 6.36; MM, 9.37; CB, 11.42; DM, 12.40; Q, 16.98; PS, 20; AC, 31.15 and OP, 91.16 P/microL. A field study was carried out to test post-treatment specificity. Blood samples from malaria patients were tested with all products (except AC and DM) on the day of treatment and 3 and 7 days thereafter, against a gold standard of microscopy and polymerase chain reaction (PCR). OP and PS produced fewer false-positive results on day 7 (18 and 19%, respectively) than the other rapid tests (38-56%). However, microscopy, PCR, OP and PS disagreed largely as to which individuals remained positive. The tests were further compared with regard to general specificity, particularly cross-reactivity with rheumatoid factor, speed, simplicity, their ability to detect other species, storage requirements and general presentation.

Disseminated intravascular coagulation in sepsis.

Disseminated intravascular coagulation (DIC) has been considered a rather rare syndrome characterized by severe bleeding. In fact, both of these beliefs are wrong. Bleeding is fairly rare in DIC. The clotting parameters are usually normal unless the DIC is fulminating. It is usually thought that fibrinogen may be low or absent in DIC. However, afibrinogenemia is rare. Fibrinogen is usually high in DIC because of the high rate of fibrinogen manufacture by the liver in response to stress. DIC is very common and most cases are never diagnosed. This is because it has been hard to find fibrin thrombi in autopsy cases and because acute severe bleeding is uncommon. The reason fibrin thrombi are rare may be because they have been lysed by endogenous fibrinolytic enzymes before the autopsy. The appearance of endogenous fibrinolytic response could be a defense mechanism to lyse the microclots of DIC. In fact, this response is often successful. This defense can be aided by the administration of plasminogen activators that will lyse the clots. Heparin has been used for the treatment of DIC but has proved useless and is, in fact, dangerous. This is because heparin will not dissolve clots and may actually promote platelet agglutination. Administration of plasminogen activators will actually prevent bleeding diathesis.

Exploring the conformational equilibrium of E. coli thioredoxin reductase: characterization of two catalytically important states by ultrafast flavin fluorescence spectroscopy.

The conformational dynamics of wild-type Escherichia coli thioredoxin reductase (TrxR) and the mutant enzyme C138S were studied by ultrafast time-resolved fluorescence of the flavin cofactor in combination with circular dichroism (both in the flavin fingerprint and far-UV regions) and steady-state fluorescence and absorption spectroscopy. The spectroscopic data show two conformational states of the enzyme (named FO and FR), of which the physical characteristics differ considerably. Ultrafast fluorescence lifetime measurements make it possible to distinguish between the two different populations: Dominant picosecond lifetimes of approximately 1 ps (contribution 75%) and 7 ps (8%) are associated with the FO species in TrxR C138S. Long-lived fluorescence with two time constants in the range of 0.2-1 ns (total contribution 17%) originates from enzyme molecules in the FR conformation. The near absence of fast lifetime components in oxidized wild-type TrxR supports the idea of this enzyme being predominantly in the FR conformation. The emission spectrum of the FO conformation is blue-shifted with respect to that of the FR conformation. Because of the large difference in fluorescence characteristics, fluorescence measurements on time scales longer than 100 ps are fully determined by the fraction of enzyme molecules in the FR conformation. Binding of the thiol reagent phenyl mercuric acetate to wild-type enzyme and TrxR C138S stabilizes the enzymes in the FR conformation. Specific binding of the NADPH-analog, AADP(+), to the FR conformation resulted in dynamic fluorescence quenching in support of the multiple quenching sites model. Raising the temperature from 277K-323K resulted in a moderate shift to the FR conformation for TrxR C138S. High concentrations of the cosolvent glycerol triggered the domain rotation from the FO to the FR conformation.

Treatment of severe acute respiratory distress syndrome: a final report on a phase I study.

Adult respiratory distress syndrome (ARDS) has a high mortality. Its only effective treatment is respiratory therapy. If this fails mortality is probably 100 per cent. No other treatment for ARDS has proved effective including "magic bullets." Twenty patients suffering from ARDS secondary to trauma and/or sepsis failed to respond to treatment with mechanical ventilation and positive end-expiratory pressure. On the assumption that disseminated intravascular coagulation initiates ARDS by occluding the pulmonary microcirculation with microclots, the patients were treated with plasminogen activators. The patients responded with significant improvement in partial pressure of oxygen in arterial blood. No bleeding occurred and clotting parameters remained normal. We conclude that ARDS can be safely treated with plasminogen activator.

Kinetic characterization of glutathione reductase from the malarial parasite Plasmodium falciparum. Comparison with the human enzyme.

The homodimeric flavoenzyme glutathione reductase (GR) maintains high intracellular concentrations of the antioxidant glutathione (GSSG + NADPH + H(+) <--> 2 GSH + NADP(+)). Due to its central function in cellular redox metabolism, inhibition of GR from the malarial parasite Plasmodium falciparum represents an important approach to antimalarial drug development; therefore, the catalytic mechanism of GR from P. falciparum has been analyzed and compared with the human host enzyme. The reductive half-reaction is similar to the analogous reaction with GR from other species. The oxidative half-reaction is biphasic, reflecting formation and breakdown of a mixed disulfide between the interchange thiol and GSH. The equilibrium between the E(ox)-EH(2) and GSSG-GSH couples has been modeled showing that the Michaelis complex, mixed disulfide-GSH, is the predominant enzyme form as the oxidative half-reaction progresses; rate constants used in modeling allow calculation of an K(eq) from the Haldane relationship, 0.075, very similar to the K(eq) of the same reaction for the yeast enzyme (0.085) (Arscott, L. D., Veine, D. M., and Williams, C. H., Jr. (2000) Biochemistry 39, 4711-4721). Enzyme-monitored turnover indicates that E(FADH(-))(S-S). NADP(+) and E(FAD)(SH)(2).NADPH are dominant enzyme species in turnover. Since the individual forms of the enzyme differ in their susceptibility to inhibitors, the prevailing states of GR in the cell are of practical relevance.

Thioredoxin reductase two modes of catalysis have evolved.

Thioredoxin reductase (EC 1.6.4.5) is a widely distributed flavoprotein that catalyzes the NADPH-dependent reduction of thioredoxin. Thioredoxin plays several key roles in maintaining the redox environment of the cell. Like all members of the enzyme family that includes lipoamide dehydrogenase, glutathione reductase and mercuric reductase, thioredoxin reductase contains a redox active disulfide adjacent to the flavin ring. Evolution has produced two forms of thioredoxin reductase, a protein in prokaryotes, archaea and lower eukaryotes having a Mr of 35 000, and a protein in higher eukaryotes having a Mr of 55 000. Reducing equivalents are transferred from the apolar flavin binding site to the protein substrate by distinct mechanisms in the two forms of thioredoxin reductase. In the low Mr enzyme, interconversion between two conformations occurs twice in each catalytic cycle. After reduction of the disulfide by the flavin, the pyridine nucleotide domain must rotate with respect to the flavin domain in order to expose the nascent dithiol for reaction with thioredoxin; this motion repositions the pyridine ring adjacent to the flavin ring. In the high Mr enzyme, a third redox active group shuttles the reducing equivalent from the apolar active site to the protein surface. This group is a second redox active disulfide in thioredoxin reductase from Plasmodium falciparum and a selenenylsulfide in the mammalian enzyme. P. falciparum is the major causative agent of malaria and it is hoped that the chemical difference between the two high Mr forms may be exploited for drug design.

Twists in catalysis: alternating conformations of Escherichia coli thioredoxin reductase.

In thioredoxin reductase (TrxR) from Escherichia coli, cycles of reduction and reoxidation of the flavin adenine dinucleotide (FAD) cofactor depend on rate-limiting rearrangements of the FAD and NADPH (reduced form of nicotinamide adenine dinucleotide phosphate) domains. We describe the structure of the flavin-reducing conformation of E. coli TrxR at a resolution of 3.0 angstroms. The orientation of the two domains permits reduction of FAD by NADPH and oxidation of the enzyme dithiol by the protein substrate, thioredoxin. The alternate conformation, described by Kuriyan and co-workers, permits internal transfer of reducing equivalents from reduced FAD to the active-site disulfide. Comparison of these structures demonstrates that switching between the two conformations involves a "ball-and-socket" motion in which the pyridine nucleotide-binding domain rotates by 67 degrees.

Prolactin stimulation of iodide uptake and incorporation into protein is polyamine-dependent in mouse mammary gland explants.

Previous studies have demonstrated that the prolactin stimulation of most lactational processes (casein, lactose, and triglyceride synthesis) requires an earlier stimulating effect of prolactin on the synthesis of the polyamines. Spermidine appears to be the specific polyamine required for prolactin to enhance milk product synthesis. Inorganic iodide is present in milk at more than an order of magnitude higher concentration than that of the maternal plasma. Since prolactin stimulates iodide accumulation in milk, the goal of these studies was to determine the role of the polyamines in this hormone response. Two drugs were employed in these studies: DFMO (difluoromethylornithine), which inhibits ornithine decarboxylase, and MGBG [methylglyoxal bis(guanyl-hydrazone)], which inhibits S-adenosyl methionine decarboxylase. In mammary gland explants from midpregnant (10-14 days of pregnancy) mice, MGBG at 100 microM abolished the prolactin stimulation of iodide uptake and incorporation into milk proteins, whereas DFMO caused a concentration-dependent inhibition of the PRL response. Selected sensitivity of the MGBG and DFMO inhibitions was validated by a reversal of the drug inhibitions with the addition of 1 mM spermidine to the culture medium. These data suggest that the polyamine signaling pathway is involved in the prolactin stimulation of iodide uptake into milk.

Mixed disulfide with glutathione as an intermediate in the reaction catalyzed by glutathione reductase from yeast and as a major form of the enzyme in the cell.

Glutathione reductase catalyzes the reduction of glutathione disulfide by NADPH. The FAD of the reductase is reduced by NADPH, and reducing equivalents are passed to a redox-active disulfide to complete the first half-reaction. The nascent dithiol of two-electron reduced enzyme (EH(2)) interchanges with glutathione disulfide forming two molecules of glutathione in the second half-reaction. It has long been assumed that a mixed disulfide (MDS) between one of the nascent thiols and glutathione is an intermediate in this reaction. In addition to the nascent dithiol composed of Cys(45) and Cys(50), the enzyme contains an acid catalyst, His(456), having a pK(a) of 9.2 that protonates the first glutathione (residue numbers refer to the yeast enzyme sequence). Reduction of yeast glutathione reductase by glutathione and reoxidation of EH(2) by glutathione disulfide indicate that the mixed disulfide accumulates, in particular, at low pH. The reaction of glutathione disulfide with EH(2) is stoichiometric in the absence of an excess of glutathione. The equilibrium position among E(ox), MDS, and EH(2) is determined by the glutathione concentration and is not markedly influenced by pH between 6.2 and 8.5. The mixed disulfide is the principal product in the reaction of glutathione with oxidized enzyme (E(ox)) at pH 6. 2. Its spectrum can be distinguished from that of EH(2) by a slightly lower thiolate (Cys(50))-FAD charge-transfer absorbance at 540 nm. The high GSH/GSSG ratio in the cytoplasm dictates that the mixed disulfide will be the major enzyme species.

Kinetic investigation of the specificity of porcine brain thyrotropin-releasing hormone-degrading ectoenzyme for thyrotropin-releasing hormone-like peptides.

Evidence indicates that neuronally released thyrotropin-releasing hormone (TRH) is selectively inactivated by TRH-degrading ectoenzyme (TRH-DE) (EC ). TRH-DE inhibitors may be used to enhance the therapeutic actions of TRH and to investigate the functions of TRH and TRH-DE in the central nervous system. Although TRH-DE appears to exhibit a high degree of specificity toward TRH, systematic specificity studies, which would facilitate inhibitor design, have not been previously conducted for this enzyme. In this paper we present the first description of TRH-DE specificity across a directed peptide library in which the histidyl (P(1)') residue of TRH was replaced by a series of amino acids. Peptides were synthesized using standard solid phase chemistry. Kinetic parameters were measured either by continuous or discontinuous fluorometric assays or by quantitative high pressure liquid chromatography. The P(1)' residue was found to influence significantly both the ability of the peptides to bind to TRH-DE, as measured by their K(i) values, and the ability of TRH-DE to catalyze their hydrolysis. Moderately bulky, uncharged P(1)' residues were found to bind preferentially to TRH-DE. Results from this screen provide valuable information for the development of TRH-DE inhibitors and have led to the identification of two potent, reversible TRH-DE inhibitors, l-pyroglutamyl-l-asparaginyl-l-prolineamide (K(i) = 17.5 micrometer) and Glp-Asn-Pro-7-amido-4-methyl coumarin (K(i) = 0.97 micrometer).

Synthesis of ketomethylene amino pseudopeptide analogues via reductive amination of glyoxals derived from alpha-amino acids.

The reductive amination of an amino acid derived glyoxal, with the free amino group of a protected amino acid or oligopeptide fragment, has been developed as a simple and efficient method for the preparation of ketomethylene amino pseudo-oligopeptide isosteres Aa psi(COCH2NH)Aa. Trichlorosilane-DMF is the reagent of choice for the reduction.