Stepped care targeting psychological distress in head and neck cancer and lung cancer patients: a randomized, controlled trial.

BACKGROUND: This study aimed to evaluate the efficacy of stepped care (SC) targeting psychological distress in head and neck cancer (HNC) and lung cancer (LC) patients. PATIENTS AND METHODS: Patients with untreated distress [Hospital Anxiety and Depression Scale (HADS; HADS-D > 7, HADS-A > 7, or HADS-total > 14)] were randomized to SC (n = 75) or care-as-usual (CAU) (n = 81). SC consisted of watchful waiting, guided self-help, problem-solving therapy, and psychotherapy and/or psychotropic medication. The primary outcome measure was the HADS; secondary outcome measures were recovery rate, EORTC QLQ-C30, QLQ-HN35/QLQ-LC13, and IN-PATSAT32. Measures were assessed at baseline, after completion of care, and at 3, 6, 9, and 12 months follow-up. Linear mixed models, t-tests, and effect sizes (ES) were used to assess group differences. RESULTS: Patients with untreated distress were randomized to SC (n = 75) or care-as-usual (CAU) (n = 81). The course of psychological distress was better after SC compared with CAU (HADS-total, P = 0.005; HADS-A, P = 0.046; HADS-D, P = 0.007). The SC group scored better post-treatment (HADS-total, ES = 0.56; HADS-A, ES = 0.38; HADS-D, ES = 0.64) and at 9 months follow-up (HADS-total, ES = 0.42 and HADS-A, ES = 0.40). The recovery rate post-treatment was 55% after SC compared with 29% after CAU (P = 0.002), and 46% and 37% at 12 months follow-up (P = 0.35). Within SC, 28% recovered after watchful waiting, 34% after guided self-help, 9% after problem-solving therapy, and 17% after psychotherapy and/or psychotropic medication. The effect of SC was stronger for patients with a depressive or anxiety disorder compared with patients without such a disorder (HADS-total, P = 0.001; HADS-A, P = 0.003; HADS-D, P = 0.041). CONCLUSIONS: SC is effective and speeds up recovery among HNC and LC patients with untreated psychological distress. TRIAL REGISTRATION: Netherlands Trial Register (NTR1868).

Prevalence of depression in cancer patients: a meta-analysis of diagnostic interviews and self-report instruments.

OBJECTIVE: We aimed to investigate the prevalence of depression in cancer patients assessed by diagnostic interviews and self-report instruments, and to study differences in prevalence between type of instrument, type of cancer and treatment phase. METHODS: A literature search was conducted in four databases to select studies on the prevalence of depression among adult cancer patients during or after treatment. A total of 211 studies met the inclusion criteria. Pooled mean prevalence of depression was calculated using Comprehensive Meta-Analysis. RESULTS: Hospital Anxiety and Depression Scale-depression subscale (HADS-D) ≥ 8, HADS-D ≥11, Center for Epidemiologic Studies ≥ 16, and (semi-)structured diagnostic interviews were used to define depression in 66, 53, 35 and 49 studies, respectively. Respective mean prevalence of depression was 17% (95% CI = 16-19%), 8% (95% CI = 7-9%), 24% (95% CI = 21-26%), and 13% (95% CI = 11-15%) (p < 0.001). Prevalence of depression ranged from 3% in patients with lung cancer to 31% in patients with cancer of the digestive tract, on the basis of diagnostic interviews. Prevalence of depression was highest during treatment 14% (95% CI = 11-17%), measured by diagnostic interviews, and 27% (95% CI = 25-30%), measured by self-report instruments. In the first year after diagnosis, prevalence of depression measured with diagnostic interviews and self-report instruments were 9% (95% CI = 7-11%) and 21% (95% CI = 19-24%), respectively, and they were 8% (95% CI = 5-12%) and 15% (95% CI = 13-17%) ≥ 1 year after diagnosis. CONCLUSIONS: Pooled mean prevalence of depression in cancer patients ranged from 8% to 24% and differed by the type of instrument, type of cancer and treatment phase. Future prospective studies should disentangle whether differences in prevalence of depression are caused by differences in the type of instrument, type of cancer or treatment phase. © 2013 The Authors. Psycho-Oncology published by John Wiley & Sons, Ltd.

Novel enzyme activities and functional plasticity revealed by recombining highly homologous enzymes.

BACKGROUND: Directed evolution by DNA shuffling has been used to modify physical and catalytic properties of biological systems. We have shuffled two highly homologous triazine hydrolases and conducted an exploration of the substrate specificities of the resulting enzymes to acquire a better understanding of the possible distributions of novel functions in sequence space. RESULTS: Both parental enzymes and a library of 1600 variant triazine hydrolases were screened against a synthetic library of 15 triazines. The shuffled library contained enzymes with up to 150-fold greater transformation rates than either parent. It also contained enzymes that hydrolyzed five of eight triazines that were not substrates for either starting enzyme. CONCLUSIONS: Permutation of nine amino acid differences resulted in a set of enzymes with surprisingly diverse patterns of reactions catalyzed. The functional richness of this small area of sequence space may aid our understanding of both natural and artificial evolution.

Selection, characterization and x-ray structure of anti-ampicillin single-chain Fv fragments from phage-displayed murine antibody libraries.

Single-chain Fv (scFv) antibody libraries were constructed from mice immunized with an ampicillin-bovine serum albumin conjugate. Several antibodies with specificity for intact ampicillin were selected by phage display and characterized. The antibody scFv fragment aL2 binds to intact ampicillin and shows no detectable cross-reactivity with hydrolyzed ampicillin. We determined the X-ray structures of two crystal forms of w.t. aL2, which differ mainly in the side-chain conformation of Trp H109 (according to a new consensus nomenclature Kabat residue number H95) in the extremely short (three residues) CDR H3 and the presence or absence of a well-resolved molecule of 2-methyl-pentane-2,4-diol in the bottom of the binding pocket. Attempts to co-crystallize aL2 with its antigen or to diffuse ampicillin into the wild-type aL2 crystals were unsuccessful, since crystal contacts obstruct the binding pocket. However, a mutant with two point mutations near the N terminus (Gln H6 replaced by Glu and Ala H10 (Kabat H9) replaced by Gly) crystallized in a form compatible with antigen-binding. Although the mutations affect the conformation of framework I, the conformations of the binding pocket of the uncomplexed wild-type aL2 and of the mutant complex were almost identical. The structure explains the specificity of the antibody for intact ampicillin and the degree of cross-reactivity of aL2 with a wide variety of ampicillin analogs. This antibody system will be very useful as a diagnostic reagent for antibiotics use and abuse, as a model for the effect of expression of antibiotic binding molecules in Escherichia coli, and for directed evolution towards high antibiotic resistance.

Characterization of novel antimicrobial peptoids.

Peptoids differ from peptides in that peptoids are composed of N-substituted rather than alpha-carbon-substituted glycine units. In this paper we report the in vitro and in vivo antibacterial activities of several antibacterial peptoids discovered by screening combinatorial chemistry libraries for bacterial growth inhibition. In vitro, the peptoid CHIR29498 and some of its analogues were active in the range of 3 to 12 microg/ml against a panel of gram-positive and gram-negative bacteria which included isolates which were resistant to known antibiotics. Peptoid antimicrobial activity against Staphylococcus aureus was rapid, bactericidal, and independent of protein synthesis. beta-Galactosidase and propidium iodide leakage assays indicated that the membrane is the most likely target of activity. Positional isomers of an active peptoid were also active, consistent with a mode of action, such as membrane disruption, that does not require a specific fit between the molecule and its target. In vivo, CHIR29498 protected S. aureus-infected mice in a simple infection model.

Selectively-infective phage (SIP): a mechanistic dissection of a novel in vivo selection for protein-ligand interactions.

Selectively-infective phage (SIP) is a novel methodology for the in vivo selection of interacting protein-ligand pairs. It consists of two components, (1) a phage particle made non-infective by replacing its N-terminal domains of geneIII protein (gIIIp) with a ligand-binding protein, and (2) an "adapter" molecule in which the ligand is linked to those N-terminal domains of gIIIp which are missing from the phage particle. Infectivity is restored when the displayed protein binds to the ligand and thereby attaches the missing N-terminal domains of gIIIp to the phage particle. Phage propagation is thus strictly dependent on the protein-ligand interaction. We have shown that the insertion of beta-lactamase into different positions of gIIIp, mimicking the insertion of a protein-ligand pair, led to highly infective phage particles. Any phages lacking the first N-terminal domain were not infective at all. In contrast, those lacking only the second N-terminal domain showed low infectivity irrespective of the presence or absence of the F-pilus on the recipient cell, which could be enhanced by addition of calcium. An anti-fluorescein scFv antibody and its antigen fluorescein were examined as a protein-ligand model system for SIP experiments. Adapter molecules, synthesized by chemical coupling of fluorescein to the purified N-terminal domains, were mixed with non-infective anti-fluorescein scFv-displaying phages. Infection events were strictly dependent on fluorescein being coupled to the N-terminal domains and showed a strong dependence on the adapter concentration. Up to 10(6) antigen-specific events could be obtained from 10(10) input phages, compared to only one antigen-independent event. Since no separation of binders and non-binders is necessary, SIP is promising as a rapid procedure to select for high affinity interactions.

Reliable cloning of functional antibody variable domains from hybridomas and spleen cell repertoires employing a reengineered phage display system.

A prerequisite for the use of recombinant antibody technologies starting from hybridomas or immune repertoires is the reliable cloning of functional immunoglobulin genes. For this purpose, a standard phage display system was optimized for robustness, vector stability, tight control of scFv-delta geneIII expression, primer usage for PCR amplification of variable region genes, scFv assembly strategy and subsequent directional cloning using a single rare cutting restriction enzyme. This integrated cloning, screening and selection system allowed us to rapidly obtain antigen binding scFvs derived from spleen-cell repertoires of mice immunized with ampicillin as well as from all hybridoma cell lines tested to date. As representative examples, cloning of monoclonal antibodies against a his tag, leucine zippers, the tumor marker EGP-2 and the insecticide DDT is presented. Several hybridomas whose genes could not be cloned in previous experimental setups, but were successfully obtained with the present system, expressed high amounts of aberrant heavy and light chain mRNAs, which were amplified by PCR and greatly exceeded the amount of binding antibody sequences. These contaminating variable region genes were successfully eliminated by employing the optimized phage display system, thus avoiding time consuming sequencing of non-binding scFv genes. To maximize soluble expression of functional scFvs subsequent to cloning, a compatible vector series to simplify modification, detection, multimerization and rapid purification of recombinant antibody fragments was constructed.

Specific detection of his-tagged proteins with recombinant anti-His tag scFv-phosphatase or scFv-phage fusions.

Using a cell-bound immunogen, we have generated a monoclonal antibody, 3D5, that recognizes carboxy-terminal oligo-histidine tags (His tags) on a wide variety of proteins. From this monoclonal antibody, we have generated a single-chain fragment of the variable domains (scFv), a dimeric scFv-alkaline phosphatase fusion and an oligovalent scFv-display phage. The antibody in its various formats is an effective tool used in fluorescence-activated cell sorting analysis, the BIAcore method, Western blots and enzyme-linked immunosorbent assay (ELISA). Western blots and ELISAs can be developed directly by using crude extracts of E.coli cells that produce the scFv-alkaline phosphatase fusion, thus providing an inexhaustable and convenient supply of detection reagent. Alternatively, oligovalent scFv-displaying phage can be used directly from culture supernatants for this purpose. The dissociation constants, KD of the peptide KGGHHHHH (KD = 4 x 10(-7) M) and of imidazole (KD = 4 x 10(-4) M) were determined. Molecular modeling of the Fv fragment suggests the occurrence of two salt bridges between the protonated histidine side chains of the peptide and the acidic groups in the antibody, explaining why the antibody or the substrate may be eluted under mildly basic conditions.

Monovalent single-chain Fv fragments and bivalent miniantibodies bound to vesicular stomatitis virus protect against lethal infection.

Several antibody-dependent mechanisms have been postulated to mediate neutralization of different animal viruses, including blocking of docking to receptors, induction of conformational changes in the virus coat, and Fc-dependent opsonization. We have studied the molecular requirements for antibody-mediated neutralization of vesicular stomatitis virus (VSV) in vitro and protection against lethal disease in vivo with a single-chain Fv fragment (scFv) and the corresponding bivalent miniantibody (scFv-dHLX) generated from a VSV-neutralizing monoclonal antibody. Both monovalent scFv and bivalent scFv-dHLX miniantibodies were able to neutralize VSV in vitro and to protect interferon-alphabeta receptor-deficient (IFN-alphabeta R-/-) mice against lethal disease after intravenous injection of 50 plaque-forming units (pfu) VSV pre-incubated with the scFv reagents. Similarly, severe-combined immunodeficient (SCID) mice infected with immune complexes of 10(8) pfu VSV and bivalent scFv-dHLX were protected against lethal disease; however, mice infected with immune complexes of 10(8) pfu VSV and monovalent scFv were not. Although repeated scFv-dHLX treatment reduced virus quantities in the blood, neither SCID nor IFN-alphabeta R-/- mice were protected against lethal disease after passive immunization and subsequent VSV infection. This was due to the short half-life of 17 min of scFv-dHLX in the circulation. These data demonstrate that neutralization of VSV and protection against lethal disease do not require Fc-mediated mechanisms and that cross-linking is not crucial for protection against physiologically relevant virus doses in vivo.

High volumetric yields of functional dimeric miniantibodies in Escherichia coli, using an optimized expression vector and high-cell-density fermentation under non-limited growth conditions.

Functional bivalent miniantibodies, directed against the epidermal growth factor receptor, accumulated to more than 3 gl-1 in high-cell-density cultures of Escherichia coli RV308(pHKK) on a pilot scale. The miniantibodies consist of scFv fragments with a C-terminal hinge followed by a helix-turn-helix motif, which homodimerizes in vivo. The improved expression vector pHKK is characterized by the hoklsok suicide system, improving plasmid maintenance, and the inducible lac pl o promoter system with the very strong T7g10 Shine-Dalgarno sequence. The expression unit is flanked by terminators. The prototrophic RV308 cells were cultivated in glucose mineral salt medium and reached a cell density of 145 g dry biomass l-1 after 33 h. After induction, growth continued almost unchanged for a further 4 h with concomitant miniantibody formation. In the fedbatch phase, the concentration of glucose was kept almost constant at the physiological level of approximately 1.5 gl-1, using on-line flow injection analysis for control. Surprisingly, E. coli RV308(pHKK) did not accumulate significant amounts of the metabolic by-product acetate under these unlimited aerobic growth conditions.

Inclusion of an upstream transcriptional terminator in phage display vectors abolishes background expression of toxic fusions with coat protein g3p.

Expression of toxic gene products affects bacterial cell growth and phage display, causing a strong selection against plasmid maintenance and integrity. During phage propagation steps, in particular, phagemid instability can dramatically affect diversity of antibody libraries or even lead to the deletion of antibody genes. We constructed a modified phage display vector by introducing a strong transcriptional terminator upstream of the lac promoter, which together with glucose suppression of its CAP-dependent activation, very efficiently represses product formation before induction.

Competition BIAcore for measuring true affinities: large differences from values determined from binding kinetics.

In attempting to use the BIAcore instrument for the determination of binding constants of several haptens or peptides to different antibodies by measuring on- and off-rates, we found that neither the absolute nor the relative values of the binding constants corresponded to the measurements in solution. Even at the lowest coupling densities useful for measurements, rebinding and bivalency effects offset the measurements by a factor of up to 500. We caution therefore about using on- and off-rates for the determination of absolute or even relative binding constants without controlling for rebinding and avidity effects. Instead, we show that binding constants in solution can be reproduced well by using on-rate determinations of antibody preincubated with antigen, and we derive the conditions under which such an approach is valid.