Brain-derived neurotrophic factor genetic polymorphism rs6265 and creativity

The protein brain-derived neurotrophic factor (BDNF) promotes neural plasticity of the central nervous system and plays an important role for learning and memory. A single nucleotide polymorphism (rs6265) at position 66 in the pro-region of the human BDNF gene, resulting in a substitution of the amino acid valine (val) with methionine (met), leads to attenuated BDNF secretion and has been associated with reduced neurocognitive function. Inhomogeneous results have been found regarding the effect of the BDNF genotype on behavior. We determined the BDNF genotype and performance on the Compound Remote Associate (CRA) task as a common measure of creativity in 76 healthy university students. In our main analyses, we did not find significant differences between met-carriers (n = 30) and non-met carriers (n = 46). In a secondary analysis, we found that met-carriers had a slower solution time (medium effect size) for items of medium difficulty. Our results suggest that met-carriers and non-met-carriers do not generally differ regarding their creativity, but non-met-carriers may have a certain advantage when it comes to moderately difficult problems. The wider literature suggests that both genetic variants come with advantages and disadvantages. Future research needs to sharpen our understanding of the disadvantages and, potentially, advantages met allele carriers may have.

Become your own SLEEPexpert: design, implementation, and preliminary evaluation of a pragmatic behavioral treatment program for insomnia in inpatient psychiatric care

Study Objectives

The majority of patients with mental disorders suffer from insomnia, associated with adverse health outcomes. Cognitive behavioral therapy for insomnia (CBT-I) represents the first-line treatment, but is too complex for severely ill patients and not systematically implemented in inpatient psychiatric care. This project aimed to develop a pragmatic behavioral treatment program that empowers inpatients with severe mental disorders to take care of their own sleep health.

Methods

CBT-I was adapted based on implementation research involving 24 inpatients with psychiatric disorders across diagnostic entities and comorbid insomnia and 30 health care providers at the University Hospital of Psychiatry and Psychotherapy, Bern. The program was implemented and evaluated by 15 patients and 22 health care providers based on interviews and questionnaires before participation and prior to discharge.

Results

Implementation research resulted in the SLEEPexpert intervention, centering on bedtime restriction and circadian adaptation in three phases; therapist-guided treatment initiation, self-management with nursing support, and self-management. Evaluative pre-post assessments in 15 patients demonstrated feasibility. Time in bed decreased by 60 minutes (520 ± 105.3 vs. 460 ± 78.1, p = 0.031, d = 0.6) and total sleep time increased by around 45 minutes (331 ± 110.6 vs. 375 ± 74.6, p = 0.09, d = 0.5), resulting in increased sleep efficiency (65.3 ± 21.8 vs. 81.9 ± 11.2%, p = 0.011, d = 0.8). Patients improved on the Insomnia Severity Index (18.3 ± 4.6 vs. 11.4 ± 4.4, p < 0.001, d = 1.2) and Pittsburgh Sleep Quality Index (12.9 ± 3.8 vs. 10.3 ± 3.3, p = 0.031, d = 0.6).

Conclusions

We propose a new pragmatic behavioral treatment program (SLEEPexpert) customized to the needs of patients and health care providers in inpatient psychiatric care. Data demonstrate feasibility. An improvement of insomnia severity was observed, but a control comparison is needed to further test for efficacy.

Schistosoma mansoni tetraspanning orphan receptor (SmTOR): a new vaccine candidate against schistosomiasis

One approach to fight against schistosomiasis is to develop an efficient vaccine. Schistosoma mansoni tetraspanning orphan receptor (SmTOR) might be a vaccine candidate, as it is a tegument membrane protein expressed most highly in cercariae. In this study we characterized the recombinant first extracellular domain of SmTOR (rSmTORed1) as having the expected property to bind C2 of complement similarly to a smaller peptide of the same domain, and to produce specific and high-titre antibodies in BALB/c mice immunized using complete Freund's adjuvant/incomplete Freund's adjuvant (CFA/IFA). Immunization was protective against parasite infection, as demonstrated by a significant decrease in worm burden in immunized BALB/c mice versus the control groups over two independent trials [64 and 45% reduction for mean adult worm burden in immunized versus phosphate-bufferd saline (PBS) injected mice]. Interestingly, infection by itself did not lead to the generation of anti-rSmTORed1 antibodies, corresponding to the low frequency of specific anti-rSmTORed1 antibodies detected in the sera of patients infected with S. mansoni (2/20; 10%). These data suggest that, as opposed to the natural infection during which SmTOR induces antibodies only rarely, immunization with its smaller first extracellular domain might be more efficient.

Caspase inhibitor P35 and inhibitor of apoptosis Op-IAP block in vivo proteolytic activation of an effector caspase at different steps

Signal-induced activation of caspases, the critical protease effectors of apoptosis, requires proteolytic processing of their inactive proenzymes. Consequently, regulation of procaspase processing is critical to apoptotic execution. We report here that baculovirus pancaspase inhibitor P35 and inhibitor of apoptosis Op-IAP prevent caspase activation in vivo, but at different steps. By monitoring proteolytic processing of endogenous Sf-caspase-1, an insect group II effector caspase, we show that Op-IAP blocked the first activation cleavage at TETD downward arrowG between the large and small caspase subunits. In contrast, P35 failed to affect this cleavage, but functioned downstream to block maturation cleavages (DXXD downward arrow(G/A)) of the large subunit. Substitution of P35's reactive site residues with TETDG failed to increase its effectiveness for blocking TETD downward arrowG processing of pro-Sf-caspase-1, despite wild-type function for suppressing apoptosis. These data are consistent with the involvement of a novel initiator caspase that is resistant to P35, but directly or indirectly inhibitable by Op-IAP. The conservation of TETD downward arrowG processing sites among insect effector caspases, including Drosophila drICE and DCP-1, suggests that in vivo activation of these group II caspases involves a P35-insensitive caspase and supports a model wherein apical and effector caspases function through a proteolytic cascade to execute apoptosis in insects.

Dietary stearic acid reduces cholesterol absorption and increases endogenous cholesterol excretion in hamsters fed cereal-based diets

The observation that dietary stearic acid does not raise plasma cholesterol concentration is well documented, although the regulating mechanisms are not completely understood. Therefore, we examined the effect of dietary stearic acid on cholesterol absorption and sterol balance using male Syrian hamsters fed modified NIH-07 cereal-based diets selectively enriched in palmitic acid (16:0), stearic acid (18:0), trans fatty acid (18:1t), cis oleic acid (18:1c) or linoleic acid (18:2). All diets contained 17 g/100 g total fat and 0.05 g/100 g cholesterol; the five fat blends were enriched 30% with the fatty acid of interest above a constant fatty acid background. Cholesterol absorption efficiency was 50-55% in all treatment groups except for the 18:0 group, in which cholesterol absorption was significantly reduced to 21%. Plasma total cholesterol concentration was significantly lower in the 18:0 group compared to the 16:0 group. Fecal neutral steroid excretion was significantly greater in hamsters fed the high 18:0 diet compared to the other treatment groups. After accounting for unabsorbed dietary cholesterol, endogenous cholesterol excretion was about 100% higher in the 18:0 group. Consequently, the calculated rate of whole body cholesterol synthesis was significantly increased by dietary 18:0. Bile acid excretion accounted for only 12-20% of total sterol output by the hamsters in this study. Thus, the data suggest that reduced plasma cholesterol concentration in hamsters fed high 18:0 diets may be influenced by reduced cholesterol absorption and increased excretion of endogenous cholesterol.

Cholesteryl ester enrichment of plasma low-density lipoproteins in hamsters fed cereal-based diets containing cholesterol

Male Syrian hamsters were fed 0.02, 0.03, or 0.05% cholesterol to test the hypothesis that moderate cholesterol intake increases the cholesteryl ester content of the plasma low-density lipoproteins (LDL). Dietary cholesterol levels of 0.02%-0.05% were chosen to reflect typical human intakes of cholesterol. Hamsters were fed ad libitum a cereal-based diet (modified NIH-07 open formula) for 15 weeks. Increasing dietary cholesterol from 0.02% to 0.05% resulted in significantly increased plasma LDL and high-density lipoprotein cholesterol concentration, increased liver cholesterol concentration, and increased total aorta cholesterol content. The cholesteryl ester content of plasma LDL was determined as the molar ratio of cholesteryl ester to apolipoprotein B and to surface lipid (i.e., phospholipid + free cholesterol). Increasing dietary cholesterol from 0.02% to 0.05% resulted in significantly increased cholesteryl ester content of LDL particles. Furthermore, cholesteryl ester content of LDL was directly associated with increased total aorta cholesterol, whereas a linear relationship between plasma LDL cholesterol concentration and aorta cholesterol was not observed. Thus, the data suggest that LDL cholesteryl ester content may be an important atherogenic feature of plasma LDL.

Crystal structure of baculovirus P35: role of a novel reactive site loop in apoptotic caspase inhibition

The aspartate-specific caspases are critical protease effectors of programmed cell death and consequently represent important targets for apoptotic intervention. Baculovirus P35 is a potent substrate inhibitor of metazoan caspases, a property that accounts for its unique effectiveness in preventing apoptosis in phylogenetically diverse organisms. Here we report the 2.2 A resolution crystal structure of P35, the first structure of a protein inhibitor of the death caspases. The P35 monomer possesses a solvent-exposed loop that projects from the protein's main beta-sheet core and positions the requisite aspartate cleavage site at the loop's apex. Distortion or destabilization of this reactive site loop by site-directed mutagenesis converted P35 to an efficient substrate which, unlike wild-type P35, failed to interact stably with the target caspase or block protease activity. Thus, cleavage alone is insufficient for caspase inhibition. These data are consistent with a new model wherein the P35 reactive site loop participates in a unique multi-step mechanism in which the spatial orientation of the loop with respect to the P35 core determines post-cleavage association and stoichiometric inhibition of target caspases.

Combination therapy with zidovudine prevents selection of human immunodeficiency virus type 1 variants expressing high-level resistance to L-697,661, a nonnucleoside reverse transcriptase inhibitor

L-697,661 is a human immunodeficiency virus type 1 (HIV-1)-specific nonnucleoside reverse transcriptase (RT) inhibitor. Its tolerability and activity in combination with zidovudine were evaluated in a 48-week double-blind study. One hundred nineteen zidovudine-naive HIV-1-infected patients with CD4 cell counts of 200-500/mm3 received either combination therapy, L-697,661 alone, or zidovudine alone. Activity was assessed by CD4 cell count changes. Selection for L-697,661-resistant virus was monitored by susceptibility testing of RT expressed by circulating viral RNA. Therapy was generally well tolerated. All groups receiving zidovudine exhibited transient increases in CD4 cell counts, while the L-697,661 monotherapy group showed a significant decline and yielded RT > 100-fold resistant to L-697,661 and associated with substitutions at RT residue 181. The RT from patients receiving combination therapy was maximally 15-fold less susceptible to L-697,661. Hence, cotreatment with zidovudine prevents selection of HIV-1 variants that are highly resistant to L-697,661 in patients naive to both compounds.

Susceptibilities of human immunodeficiency virus type 1 enzyme and viral variants expressing multiple resistance-engendering amino acid substitutions to reserve transcriptase inhibitors

To evaluate the potential that multiply resistant human immunodeficiency virus type 1 variants may arise during combination nucleoside and nonnucleoside reverse transcriptase inhibitor therapy, we constructed a series of mutant reverse transcriptase enzymes and viruses that coexpressed various combinations of resistance-associated amino acid substitutions. Substitutions at residues 100 (Leu-->Ile) and 181 (Tyr-->Cys), which mediate resistance to the nonnucleosides, suppressed resistance to 3'-azido-3'-deoxythymidine (AZT) when coexpressed with AZT-specific substitutions. However, a number of viral variants that exhibited significantly reduced susceptibilities to both classes of inhibitors were constructed.

Comprehensive mutant enzyme and viral variant assessment of human immunodeficiency virus type 1 reverse transcriptase resistance to nonnucleoside inhibitors

The nonnucleoside reverse transcriptase (RT) inhibitors comprise a class of structurally diverse compounds that are functionally related and specific for the human immunodeficiency virus type 1 RT. Viral variants resistant to these compounds arise readily in cell culture and in treated, infected human. Therefore, the eventual clinical usefulness of the nonnucleoside inhibitors will rely on a thorough understanding of the genetic and biochemical bases for resistance. A study was performed to assess the effects of substitutions at each RT amino acid residue that influences the enzyme's susceptibility to the various nonnucleoside compounds. Single substitutions were introduced into both purified enzyme and virus. The resulting patterns of resistance were markedly distinct for each of the tested inhibitors. For instance, a > 50-fold loss of enzyme susceptibility to BI-RG-587 was engendered by any of four individual substitutions, while the same level of relative resistance to the pyridinone derivatives was mediated only by substitution at residue 181. Similarly, substitution at residue 181. Similarly, substitution at residue 106 had a noted effect on virus resistance to BI-RG-587 but not to the pyridinones. The opposite effect was mediated by a substitution at residue 179. Such knowledge of nonucleoside inhibitor resistance profiles may help in understanding the basis for resistant virus selection during clinical studies of these compounds.

Requirement of active human immunodeficiency virus type 1 integrase enzyme for productive infection of human T-lymphoid cells

The human immunodeficiency virus type 1 (HIV-1) integrase enzyme exhibits significant amino acid sequence conservation with integrase proteins of other retroviruses. We introduced specific amino acid substitutions at a number of the conserved residue positions of recombinant HIV-1 integrase. Some of these substitutions resulted in proteins which were not able to be purified in the same manner as the wild-type enzyme, and these were not studied further. The remaining mutant enzymes were assessed for their abilities to perform functions characteristic of the integrase protein. These included specific removal of the terminal dinucleotides from oligonucleotide substrates representative of the viral U5-long terminal repeat, nonspecific cleavage of oligonucleotide substrates, and mediation of the strand transfer (integration) reaction. Substitution at position 43, within the protein's zinc finger motif region, resulted in an enzyme with reduced specificity for cleavage of the terminal dinucleotide. In addition, a double substitution of aspartic acid and glutamine for valine and glutamic acid, respectively, at positions 151 and 152 within the D,D(35)E motif region rendered the integrase protein inactive for all of its functions. The introduction of this double substitution into an infectious HIV-1 provirus yielded a mutant virus that was incapable of productively infecting human T-lymphoid cells in culture.

Prevalence of vitamin and mineral supplement use in the elderly

This study examines the belief of many health professionals that the elderly are vulnerable to misconceptions of what constitutes good nutrition, especially as it relates to the use of vitamin and mineral supplements. A canvass of several census tracts in Toledo and several townships in Defiance County, Ohio, identified 309 individuals 60 years of age or older who agreed to participate in this study. Forty-nine percent of those interviewed used some vitamin or mineral supplement. Of these, 77 percent were taking a multiple vitamin. Women were more likely to use supplements than men (53 percent vs 38 percent), and supplement use increased across the three age categories: 60 to 69 years (42 percent), 70 to 79 years (48 percent), 80 years and older (60 percent). More than 85 percent of those using supplements spent less than 2 percent of their income on supplements. Health benefits were perceived by 94 percent of those using supplements.