Effects of an adjunctive,chronotype-based light therapy in hospitalized patients with severe burnout symptoms - a pilot study

Light therapy is a well-established treatment option for seasonal affective disorders and is effective in reducing sleep problems and daytime fatigue. Symptoms of severe burnout include feelings of exhaustion and impaired sleep and mood. Thus, light therapy seems promising for burnout treatment. So far, light therapy effects in burnout were investigated in outpatient settings only, with inconclusive results. The present study targeted light therapy effects in an inpatient setting. Participants with severe burnout were recruited in two psychosomatic clinics and randomly assigned to a control group with multimodal psychiatric treatment or an add-on light treatment group. Participants in the latter group were additionally exposed to morning bright light (illuminance: 4246 lux, irradiance: 1802.81 µW.cm^?2) for 3 weeks, 30 minutes a day, timed to their chronotypes. Light effects on burnout symptoms, depression, well-being, daytime sleepiness, sleep quality, and attentional performance were measured twice (pre-/postintervention design). Adjunctive chronotype-based bright light therapy was well tolerated and improved burnout symptoms and well-being without additional effect on severity of depression. Furthermore, reduced daytime sleepiness, improved nighttime sleep quality, a sleep phase advance of 25 minutes, shortened sleep latency, less sleep disturbances and increased sleep duration were observed in the light treatment group. No group differences were found in attentional performance. Chronotype-based bright light therapy seems to be effective in improving burnout symptoms and sleep problems in patients with severe burnout symptoms. Further studies with larger sample sizes and objective measures of sleep are necessary to confirm these preliminary results before practical recommendations can be made.     

Genome Sequence of OXA-48 Carbapenemase-Producing Klebsiella pneumoniae KpO3210

Klebsiella pneumoniae KpO3210 is a OXA-48 carbapenemase-producing isolate obtained from a blood culture in the context of an outbreak in Hospital Universitario La Paz (Madrid, Spain) in 2010. It belongs to the major clone detected during the outbreak and is resistant to all beta-lactams and to several other antibiotics.     

Computational predictions and experimental affinity distributions for a homovanillic acid molecularly imprinted polymer

Density Functional Theory calculations have been used to select, among a set of chemicals traditionally used in the formulation of non-covalent molecularly imprinted polymers (MIPs), the best functional monomer and porogenic solvent for the construction of a recognition element for the dopamine metabolite homovanillic acid (HVA). Theoretical predictions were confirmed through batch binding assays and voltammetric detection. The computational method predicts that trifluoromethacrylic acid and toluene are the monomer and solvent rendering the highest stabilization energy for the pre-polymerization adducts. HVA-MIP prepared using this formulation gives rise to a binding isotherm that is accurately modelled by the Freundlich isotherm. The binding properties of this polymer were estimated using affinity distribution analysis. An apparent number of sites of 13 micromol g(-1) with an average affinity constant of 2 x 10(4) M(-1) was obtained in the concentration window studied.     

Comparative cytogenetics of three species of Dichotomius (Coleoptera, Scarabaeidae)

Meiotic and mitotic chromosomes of Dichotomius nisus, D. semisquamosus and D. sericeus were analyzed after conventional staining, C-banding and silver nitrate staining. In addition, Dichotomius nisus and D. semisquamosus chromosomes were also analyzed after fluorescent in situ hybridization (FISH) with an rDNA probe. The species analyzed had an asymmetrical karyotype with 2n = 18 and meta-submetacentric chromosomes. The sex determination mechanism was of the Xy(p) type in D. nisus and D. semisquamosus and of the Xy (r) type in D. sericeus. C-banding revealed the presence of pericentromeric blocks of constitutive heterochromatin (CH) in all the chromosomes of the three species. After silver staining, the nucleolar organizer regions (NORs) were located in autosomes of D. semisquamosus and D. sericeus and in the sexual bivalent of D. nisus. FISH with an rDNA probe confirmed NORs location in D. semisquamosus and in D. nisus. Our results suggest that chromosome inversions and fusions occurred during the evolution of the group.     

Neutralization of Human Respiratory Syncytial Virus Infectivity by Antibodies and Low-Molecular-Weight Compounds Targeted against the Fusion Glycoprotein

Human respiratory syncytial virus (HRSV) fusion (F) protein is an essential component of the virus envelope that mediates fusion of the viral and cell membranes, and, therefore, it is an attractive target for drug and vaccine development. Our aim was to analyze the neutralizing mechanism of anti-F antibodies in comparison with other low-molecular-weight compounds targeted against the F molecule. It was found that neutralization by anti-F antibodies is related to epitope specificity. Thus, neutralizing and nonneutralizing antibodies could bind equally well to virions and remained bound after ultracentrifugation of the virus, but only the former inhibited virus infectivity. Neutralization by antibodies correlated with inhibition of cell-cell fusion in a syncytium formation assay, but not with inhibition of virus binding to cells. In contrast, a peptide (residues 478 to 516 of F protein [F478-516]) derived from the F protein heptad repeat B (HRB) or the organic compound BMS-433771 did not interfere with virus infectivity if incubated with virus before ultracentrifugation or during adsorption of virus to cells at 4°C. These inhibitors must be present during virus entry to effect HRSV neutralization. These results are best interpreted by asserting that neutralizing antibodies bind to the F protein in virions interfering with its activation for fusion. Binding of nonneutralizing antibodies is not enough to block this step. In contrast, the peptide F478-516 or BMS-433771 must bind to F protein intermediates generated during virus-cell membrane fusion, blocking further development of this process.Human respiratory syncytial virus (HRSV), a member of the Pneumovirus genus of the Paramyxoviridae family, is the main cause of severe lower respiratory tract infections in very young children (36), and it is a pathogen of considerable importance in the elderly (24, 26) and in immunocompromised adults (22). Currently, there is no effective vaccine against the virus although it is known that passive administration of neutralizing antibodies to individuals at high risk is an effective immunoprophylaxis (37, 38).The HRSV genome is a single-stranded negative-sense RNA molecule of approximately 15 kb that encodes 11 proteins (16, 53). Two of these proteins are the main surface glycoproteins of the virion. These are (i) the attachment (G) protein, which mediates virus binding to cells (44), and (ii) the fusion (F) protein, which promotes both fusion of the viral and cell membranes at the initial stages of the infectious cycle and fusion of the membrane of infected cells with those of adjacent cells to form characteristic syncytia (72). These two glycoproteins are the only targets of neutralizing antibodies either induced in animal models (19, 63, 65, 70) or present in human sera (62).The G protein is a highly variable type II glycoprotein that shares neither sequence identity nor structural features with the attachment protein of other paramyxoviruses (75). It is synthesized as a precursor of about 300 amino acids (depending on the strain) that is modified posttranslationally by the addition of a large number of N- and O-linked oligosaccharides and is also palmitoylated (17). The G protein is oligomeric (probably a homotetramer) (23) and promotes binding of HRSV to cell surface proteoglycans (35, 40, 49, 67). Whether this is the only interaction of G with cell surface components is presently unknown.The F protein is a type I glycoprotein that is synthesized as an inactive precursor of 574 amino acids (F0) which is cleaved by furin during transport to the cell surface to yield two disulfide-linked polypeptides, F2 from the N terminus and F1 from the C terminus (18). Like other viral type I fusion proteins, the mature F protein is a homotrimer which is in a prefusion, metastable, conformation in the virus particle. After fusion, the F protein adopts a highly stable postfusion conformation. Stability of the postfusion conformation is determined to great extent by two heptad repeat (HR) sequences, HRA and HRB, present in the F1 chain. Mixtures of HRA and HRB peptides form spontaneously heterotrimeric complexes (43, 51) that assemble in six-helix bundles (6HB), consisting of an internal core of three HRA helices surrounded by three antiparallel HRB helices, as determined by X-ray crystallography (79).The three-dimensional (3D) structure of the HRSV F protein has not been solved yet. Nevertheless, the structures of the pre- and postfusion forms of two paramyxovirus F proteins have revealed substantial conformational differences between the pre- and postfusion conformations (77, 78). The present hypothesis about the mechanism of membrane fusion mediated by paramyxovirus F proteins proposes that, following binding of the virus to the cell surface, the prefusion form of the F glycoprotein is activated, and membrane fusion is triggered. The F protein experiences then a series of conformational changes which include the exposure of a hydrophobic region, called the fusion peptide, and its insertion into the target membrane. Subsequent refolding of this intermediate leads to formation of the HRA and HRB six-helix bundle, concomitant with approximation of the viral and cell membranes that finally fuse, placing the fusion peptide and the transmembrane domain in the same membrane (4, 20). The formation of the 6HB and the associated free energy change are tightly linked to the merger of the viral and cellular membranes (60).Antibodies play a major role in protection against HRSV. Animal studies have demonstrated that immunization with either F or G glycoproteins induces neutralizing antibodies and protects against a viral challenge (19, 63, 70). Furthermore, transfer of these antibodies (31, 56) or of anti-F or anti-G monoclonal antibodies (MAbs) protects mice, cotton rats, or calves against either a human or bovine RSV challenge, respectively (65, 68, 73). Likewise, infants at high risk of severe HRSV disease are protected by the prophylactic administration of immunoglobulins with high anti-HRSV neutralizing titers (33). Finally, a positive correlation was found between high titers of serum neutralizing antibodies and protection in adult volunteers challenged with HRSV (34, 74), while an inverse correlation was found between high titers of neutralizing antibodies and risk of infection in children (29) and in the elderly (25).Whereas all the anti-G monoclonal antibodies reported to date are poorly neutralizing (1, 28, 48, 71), some anti-F monoclonal antibodies have strong neutralization activity (1, 3, 5, 28, 46). It is believed that HRSV neutralization by anti-G antibodies requires simultaneous binding of several antibodies to different epitopes, leading to steric hindrance for interaction of the G glycoprotein with the cell surface. Indeed, it has been shown that neutralization is enhanced by mixtures of anti-G monoclonal antibodies (1, 50), mimicking the effect of polyclonal anti-G antibodies. In contrast, highly neutralizing anti-F monoclonal antibodies do not require cooperation by other antibodies to block HRSV infectivity efficiently (1).In addition to neutralizing antibodies, other low-molecular-weight compounds directed against the F protein are potent inhibitors of HRSV infectivity. Synthetic peptides that reproduce sequences of heptad repeat B inhibit both membrane fusion promoted by the F protein and HRSV infectivity (42). Also, other small molecules obtained by chemical synthesis have been shown to interact with F protein and inhibit HRSV infectivity. These HRSV entry inhibitors have been the topic of intense research in recent years (55).This study explores the mechanisms of HRSV neutralization by different inhibitors of membrane fusion, including anti-F monoclonal antibodies, an HRB peptide, and the synthetic compound BMS-433771 (13-15). The results obtained indicate that antibodies and low-molecular-weight compounds block membrane fusion at different stages during virus entry.     

Hematologic and biochemical reference intervals for Spanish ibex

We studied blood samples from 529 Spanish ibexes (Capra pyrenaica) from different Andalusian mountain ranges in southern Spain, primarily from Sierra Nevada. For each sample, 13 hematologic and 32 biochemical parameters were analyzed. Within this database, we selected values obtained from live, free-ranging, physically restrained, clinically normal animals to determine reference intervals for these parameters. Distribution of values within each parameter was determined and differences in values between sex and age classes also were determined. We found significant differences in eight biochemical parameters among male and female ibexes. Significant differences in values for 20 hematologic and biochemical parameters between age classes also were found.     

Binomial regression with misclassification

Motivated by a study of human papillomavirus infection in women, we present a Bayesian binomial regression analysis in which the response is subject to an unconstrained misclassification process. Our iterative approach provides inferences for the parameters that describe the relationships of the covariates with the response and for the misclassification probabilities. Furthermore, our approach applies to any meaningful generalized linear model, making model selection possible. Finally, it is straightforward to extend it to multinomial settings.     

Structural (betaalpha)8 TIM barrel model of 3-hydroxy-3-methylglutaryl-coenzyme A lyase

This study describes three novel homozygous missense mutations (S75R, S201Y, and D204N) in the 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) lyase gene, which caused 3-hydroxy-3-methylglutaric aciduria in patients from Germany, England, and Argentina. Expression studies in Escherichia coli show that S75R and S201Y substitutions completely abolished the HMG-CoA lyase activity, whereas D204N reduced catalytic efficiency to 6.6% of the wild type. We also propose a three-dimensional model for human HMG-CoA lyase containing a (betaalpha)8 (TIM) barrel structure. The model is supported by the similarity with analogous TIM barrel structures of functionally related proteins, by the localization of catalytic amino acids at the active site, and by the coincidence between the shape of the substrate (HMG-CoA) and the predicted inner cavity. The three novel mutations explain the lack of HMG-CoA lyase activity on the basis of the proposed structure: in S75R and S201Y because the new amino acid residues occlude the substrate cavity, and in D204N because the mutation alters the electrochemical environment of the active site. We also report the localization of all missense mutations reported to date and show that these mutations are located in the beta-sheets around the substrate cavity.