Psychological distress modulates dorsal anterior cingulate cortex responses to salient stimuli in obsessive-compulsive disorder.

BACKGROUND: Patients with obsessive-compulsive disorder (OCD) experience an exacerbation of symptoms under psychological distress. The neurobiological underpinnings of this effect of stress remain elusive. Here, we induced psychological distress to explore its effect on neural reactivity of the salience network during a symptom provocation task. METHODS: Twenty-three patients with OCD and twenty-three healthy volunteers underwent functional magnetic resonance imaging scanning after stress induction and a control condition in a cross-over design. Psychological distress was induced using the socially evaluated cold pressor test (SECPT) and neural responses were measured during a symptom provocation task. RESULTS: OCD participants showed a blunted cortisol response to the stressor. We found a group by stress interaction effect in the dorsal anterior cingulate cortex (dACC), such that psychological distress reduced dACC reactivity to emotionally salient pictures in OCD participants, whereas it increased dACC reactivity in healthy controls. LIMITATIONS: A considerable proportion of OCD participants was on medication, and the neuroimaging session was conducted more than 1 h after the initial stressor. CONCLUSIONS: Considering this timeline, we speculate that the blunted dACC reactivity towards emotionally salient pictures in OCD participants may reflect impaired emotion regulation in the aftermath of stress.

The impact of the multidisciplinary Endocarditis Team on the management of infective endocarditis.

BACKGROUND: In their latest guidelines for infective endocarditis (IE) (2015), the European Society of Cardiology (ESC) introduced the implementation of the Endocarditis Team (ET) to facilitate the management of IE. This study presents our experiences and the diagnostic and therapeutic impact of the ET on the management of IE. METHODS: From 2016-2020, data of all patients with suspected IE referred to the ET were prospectively collected. The final diagnosis was defined by the ET as either rejected, possible or definite IE. Diagnostic impact was scored as any change in initial diagnosis, the frequency of additional diagnostic tests advised by the ET and any change in diagnosis after these tests. Therapeutic impact was scored as any change in antibiotic therapy or change from conservative to invasive therapy or vice versa. RESULTS: A total of 321 patients (median age 67 [55-77] years, 71% male) were enrolled. The final diagnosis was rejected IE in 47 (15%), possible IE in 34 (11%) and definite IE in 240 (75%) patients. A change of initial diagnosis was seen in 53/321(17%) patients. Additional microbiological tests were advised in 69/321 (21%) patients, and additional imaging tests in 136/321 (42%) patients, which resulted in subsequent change in diagnosis in 23/321 (7%) patients. Any change in antibiotic treatment was advised in 135/321 (42%) patients, and change from initial conservative to additional surgical treatment in 15/321 (5%) patients. CONCLUSION: The ET had a clear impact on the therapeutic policy for patients with suspected IE and is useful in the management of this life-threatening disease. Broad implementation is warranted.

Molecular characterization of piezotolerant and stress-resistant mutants of Staphylococcus aureus.

AIMS: In the previous work, following a pressure treatment with wild-type Staphylococcus aureus, we obtained piezotolerant isolates showing altered phenotypic characteristics. This work focuses on understanding the genetic background of their altered phenotype. METHODS AND RESULTS: AK23, a representative piezotolerant isolate was subjected to DNA microarrays, corroborated by PCR product sequencing and revealed 10-gene deletion. All other piezotolerant isolates possessed the mutation encompassing the region from SAR0665 to SAR0674 genes (9351 bp) which was most likely the result of recombination between two homologous loci (ATTGCGGGTG) present in both genes. RNA microarray transcriptomic analysis showed that due to partial deletion of the low-affinity phosphate transporter pitA, the high-affinity PhoU-PstABCS operon was upregulated in AK23 which could be the reason for piezotolerance. Furthermore, AK23 showed low levels of the virulence gene regulator rnaIII resulting in the downregulation of several agr system genes explaining the impaired virulence characteristics of the mutant. CONCLUSIONS: Naturally occurring mutations can result in piezotolerance which can be of a concern for high hydrostatic pressure-treated foods. SIGNIFICANCE AND IMPACT OF THE STUDY: A locus has been identified in piezotolerant S. aureus mutants providing insight into possible mechanisms associated with phenotypic characteristics of S. aureus. Further work should study each individual gene of the locus.

Evidence for Distinct Forms of Compulsivity in the SAPAP3 Mutant-Mouse Model for Obsessive-Compulsive Disorder.

The specific mechanisms underlying compulsive behavior in obsessive-compulsive disorder (OCD) are unknown. It has been suggested that such compulsivity may have its origin in cognitive dysfunction such as impaired processing of feedback information, received after the completion of goal-directed actions. The signal attenuation (SA) task models such a processing deficit in animals by attenuating the association strength between food reward and audiovisual feedback (signal) presented after performance of an operant response. The compulsive-like responding resulting from SA is well characterized in rats, but was so far not established in mice, a species for which powerful genetic OCD models exist. Thus, first, we demonstrate that the SA task can be implemented in mice and show that attenuation of reward-associated response feedback produces similar behavior in C57BL/6 mice as previously reported in rats. Second, we tested the hypothesis that SAPAP3 knock-out mice (SAPAP3-/-), prone to exhibit several OCD-like abnormalities including excessive grooming, show enhanced compulsive-like behavior in the SA task compared with their wild-type (WT) littermates. However, task-related compulsivity measures in SAPAP3-/- and WT did not yield significant differences, neither following SA nor during "regular" extinction of operant behavior. Thus, compulsive-like instrumental behavior following feedback distortion was not potentiated in compulsively grooming mice, implicating specifically that (1) a general deficit in feedback processing is not related to excessive grooming in SAPAP3-/- and (2) different manifestations of compulsivity may be driven by independent mechanisms.

Attachment in OCD: A meta-analysis.

INTRODUCTION: It has been proposed to extend the cognitive-behavioural model of obsessive-compulsive disorder (OCD) with attachment theory to shed light on the affective and developmental factors underlying the disease. With a growing number of empirical studies on the subject, this meta-analysis aims to quantify a possible relationship between attachment insecurity and OCD. METHODS: A systematic search was conducted for studies in adult populations of patients with OCD as well as general populations displaying symptoms of OCD. Effect sizes of attachment anxiety and attachment avoidance were calculated separately. Covariates of demographic variables were used in meta-regressions. RESULTS: Sixteen studies were included. Meta-analyses showed an association of medium to large effect size (Hedges' g = 0.69; 95 % CI 0.58 - 0.80; p < 0.001) between OCD and attachment anxiety, and an association of medium effect size (Hedges' g = 0.47; 95 % CI 0.39 - 0.54; p < 0.001) between OCD and attachment avoidance. Effect sizes in OCD population and general population studies did not differ significantly. DISCUSSION: Robust effect sizes of both attachment anxiety and avoidance in relation to OCD symptomatology corroborate an attachment-centred view of OCD. These findings furthermore suggest that integrating cognitive and attachment-based therapeutic approaches to OCD may benefit patients in which developmental or emotional factors hinder successful treatment.

The effect of certolizumab drug concentration and anti-drug antibodies on TNF neutralisation.

OBJECTIVES: Tumour necrosis factor (TNF) inhibitors like certolizumab, elicit an immunogenic response leading to the formation of anti-drug antibodies (ADAs). We sought to mechanistically investigate the relationship between certolizumab concentrations, ADAs, and the effective TNF neutralising capacity in sera of rheumatoid arthritis (RA) patients. TNF neutralising capacity of certolizumab was compared to the neutralising capacity of adalimumab. METHODS: Serum samples were collected from 40 consecutive certolizumab-treated RA patients at baseline and 4, 16, 28 and 52 weeks after treatment initiation [Dutch Trial Register NTR (Nederlands Trial Register) Trial NL2824 no. 2965]. Certolizumab concentration and ADA titre were measured with a certolizumab bridging enzyme-linked immunosorbent assay (ELISA) and a drug-tolerant radioimmunoassay (RIA), respectively. TNF neutralisation by certolizumab and adalimumab, in presence or absence of ADAs, was analysed with the TNF-sensitive WEHI bioassay. RESULTS: Despite a high incidence of ADAs during one year of follow-up (65%; 26/40 patients), certolizumab levels of >10 µg/ml were measured in most patients. The capacity for TNF neutralisation highly correlated with certolizumab serum concentration, whereas no association with ADAs was observed. Similar results were obtained for adalimumab. The relative in vitro neutralising potency was higher for certolizumab compared to adalimumab. CONCLUSIONS: Anti-certolizumab antibodies were detected in a large proportion of patients, but in most cases where ADAs were detected, certolizumab was also present in high concentrations, directly correlating with in vitro neutralising capacity. These results indicate that measurement of certolizumab drug levels, rather than ADAs, have direct clinical significance.

Antimicrobial susceptibility testing of Gram-positive and -negative bacterial isolates directly from spiked blood culture media with Raman spectroscopy.

Patients suffering from bacterial bloodstream infections have an increased risk of developing systematic inflammatory response syndrome (SIRS), which can result in rapid deterioration of the patients' health. Diagnostic methods for bacterial identification and antimicrobial susceptibility tests are time-consuming. The aim of this study was to investigate whether Raman spectroscopy would be able to rapidly provide an antimicrobial susceptibility profile from bacteria isolated directly from positive blood cultures. First, bacterial strains (n = 133) were inoculated in tryptic soy broth and incubated in the presence or absence of antibiotics for 5 h. Antimicrobial susceptibility profiles were analyzed by Raman spectroscopy. Subsequently, a selection of strains was isolated from blood cultures and analyzed similarly. VITEK®2 technology and broth dilution were used as the reference methods. Raman spectra from 67 antibiotic-susceptible strains showed discriminatory spectra in the absence or at low concentrations of antibiotics as compared to high antibiotic concentrations. For 66 antibiotic-resistant strains, no antimicrobial effect was observed on the bacterial Raman spectra. Full concordance with VITEK®2 data and broth dilution was obtained for the antibiotic-susceptible strains, 68 % and 98 %, respectively, for the resistant strains. Discriminative antimicrobial susceptibility testing (AST) profiles were obtained for all bacterial strains isolated from blood cultures, resulting in full concordance with the VITEK®2 data. It can be concluded that Raman spectroscopy is able to detect the antimicrobial susceptibility of bacterial species isolated from a positive blood culture bottle within 5 h. Although Raman spectroscopy is cheap and rapid, further optimization is required, to fulfill a great promise for future AST profiling technology development.

Kirschner wire pin site infection in hand and wrist fractures: incidence rate and risk factors.

Kirschner wires are widely used for skeletal fixation of unstable fractures, but the pin tracks create a potential pathway through the skin and into the bone for bacteria to cause an infection. We tested the null hypothesis that there are no demographic, patient-related, injury, or treatment variables independently associated with the occurrence of pin site infection after percutaneous fixation of hand and wrist fractures using Kirschner wires. A retrospective review of 1213 patients with one or more fractures of the hand and wrist treated with percutaneous Kirschner wire fixation identified 85 patients (7%) who had additional treatment with oral antibiotics, early pin removal, or reoperation related to a pin site infection. We found no factors were independently associated with higher or lower risks of pin site infection in multivariable logistic regression analysis. Pin site infections - most benign - occur in a notable number of patients and we could not identify any modifiable risk factors. LEVEL OF EVIDENCE: III.

Raman spectroscopy-based identification of nosocomial outbreaks of the clonal bacterium Escherichia coli.

DNA-based techniques are frequently used to confirm the relatedness of putative outbreak isolates. These techniques often lack the discriminatory power when analyzing closely related microbes such as E. coli. Here the value of Raman spectroscopy as a typing tool for E. coli in a clinical setting was retrospectively evaluated.

Comparison of Raman spectroscopy and two molecular diagnostic methods for Burkholderia cepacia complex species identification.

OBJECTIVES: Burkholderia cepacia complex (Bcc) and Pseudomonas aeruginosa strains, colonize the respiratory tract of cyctic fibrosis patients. These strains are phenotypically difficult to discriminate, but differ greatly in their pathogenic potential and species identification is relevant. Here, three methods were compared for their diagnostic capacity. METHODS: A Bcc collection was analyzed with Raman spectroscopy, AFLP and rep-PCR analysis. RESULTS: Raman spectroscopy of 40 strains revealed high similarity. Rep-PCR and AFLP of respectively 96 and 112 strains revealed that Bcc strains could be distinguished from Pseudomonas strains. Both molecular methods allowed the identification of most Bcc species according to previous phenotypic and molecular characterization. CONCLUSION: Both AFLP and rep-PCR method data correspond with the previously reported species identification. However, Raman spectroscopy does not discriminate among P. aeruginosa and Bcc species and is therefore not useful as a diagnostic tool.

Assessing transmission of crop diseases by insect vectors in a landscape context.

Theory indicates that landscape composition affects transmission of vector-borne crop diseases, but few empirical studies have investigated how landscape composition affects plant disease epidemiology. Since 2006, Bemisia tabaci (Gennadius) has vectored the cucurbit yellow stunting disorder virus (CYSDV) to cantaloupe and honeydew melons (Cucumis melo L.) in the southwestern United States and northern Mexico, causing significant reductions in yield of fall melons and increased use of insecticides. Here, we show that a landscape-based approach allowing simultaneous assessment of impacts of local (i.e., planting date) and regional (i.e., landscape composition) factors provides valuable insights on how to reduce crop disease risks. Specifically, we found that planting fall melon fields early in the growing season, eliminating plants germinating from seeds produced by spring melons after harvest, and planting fall melon fields away from cotton and spring melon fields may significantly reduce the incidence of CYSDV infection in fall melons. Because the largest scale of significance of the positive association between abundance of cotton and spring melon fields and CYSDV incidence was 1,750 and 3,000 m, respectively, reducing areas of cotton and spring melon fields within these distances from fall melon fields may decrease CYSDV incidence. Our results indicate that landscape-based studies will be fruitful to alleviate limitations imposed on crop production by vector-borne diseases.

Discrimination of Aspergillus lentulus from Aspergillus fumigatus by Raman spectroscopy and MALDI-TOF MS.

In 2005, a new sibling species of Aspergillus fumigatus was discovered: Aspergillus lentulus. Both species can cause invasive fungal disease in immune-compromised patients. The species are morphologically very similar. Current techniques for identification are PCR-based or morphology-based. These techniques are labour-intense and not sufficiently discriminatory. Since A. lentulus is less susceptible to several antifungal agents, it is important to correctly identify the causative infectious agent in order to optimize antifungal therapy. In this study we determined whether Raman spectroscopy and/or MALDI-TOF MS were able to differentiate between A. lentulus and A. fumigatus. For 16 isolates of A. lentulus and 16 isolates of A. fumigatus, Raman spectra and peptide profiles were obtained using the Spectracell and MALDI-TOF MS (VITEK MS RUO, bioMérieux) respectively. In order to obtain reliable Raman spectra for A. fumigatus and A. lentulus, the culture medium needed to be adjusted to obtain colourless conidia. Only Raman spectra obtained from colourless conidia were reproducible and correctly identified 25 out of 32 (78 %) of the Aspergillus strains. For VITEK MS RUO, no medium adjustments were necessary. Pigmented conidia resulted in reproducible peptide profiles as well in this case. VITEK MS RUO correctly identified 100 % of the Aspergillus isolates, within a timeframe of approximately 54 h including culture. Of the two techniques studied here, VITEK MS RUO was superior to Raman spectroscopy in the discrimination of A. lentulus from A. fumigatus. VITEK MS RUO seems to be a successful technique in the daily identification of Aspergillus spp. within a limited timeframe.

[The subclinical course of a paracetamol intoxication: pitfall for patient and clinician]. / Het subklinische beloop van een paracetamolintoxicatie: valkuil voor patiënt en behandelaar.

A 24-year-old man took 20 grams of paracetamol during a hospital stay in the department of psychiatry. It was not until 60 hours later that therapy with acetylcysteine was initiated. Paracetamol intoxication has a long latency period. If there is no intervention, severe hepatic damage can develop within three days. Even after a few days have passed it is still advisable to start treating the patient with acetylcysteine.

TRIB1 constitutes a molecular link between regulation of sleep and lipid metabolism in humans.

Epidemiological studies show association between sleep duration and lipid metabolism. In addition, inactivation of circadian genes induces insulin resistance and hyperlipidemia. We hypothesized that sleep length and lipid metabolism are partially controlled by the same genes. We studied the association of total sleep time (TST) with 60 genetic variants that had previously been associated with lipids. The analyses were performed in a Finnish population-based sample (N = 6334) and replicated in 2189 twins. Finally, RNA expression from mononuclear leucocytes was measured in 10 healthy volunteers before and after sleep restriction. The genetic analysis identified two variants near TRIB1 gene that independently contributed to both blood lipid levels and to TST (rs17321515, P = 8.92(*)10(-5), Bonferroni corrected P = 0.0053, ß = 0.081 h per allele; rs2954029, P = 0.00025, corrected P = 0.015, ß = 0.076; P<0.001 for both variants after adjusting for blood lipid levels or body mass index). The finding was replicated in the twin sample (rs17321515, P = 0.022, ß = 0.063; meta-analysis of both samples P = 8.1(*)10(-6), ß = 0.073). After the experimentally induced sleep restriction period TRIB1 expression increased 1.6-fold and decreased in recovery phase (P = 0.006). In addition, a negative correlation between TRIB1 expression and slow wave sleep was observed in recovery from sleep restriction. These results show that allelic variants of TRIB1 are independently involved in regulation of lipid metabolism and sleep. The findings give evidence for the pleiotropic nature of TRIB1 and may reflect the shared roots of sleep and metabolism. The shared genetic background may at least partially explain the mechanism behind the well-established connection between diseases with disrupted metabolism and sleep.

Raman spectroscopic analysis of the clonal and horizontal spread of CTX-M-15-producing Klebsiella pneumoniae in a neonatal intensive care unit.

Nosocomial outbreaks of extended-spectrum ß-lactamase (ESBL)-producing Klebsiella pneumoniae are an increasing concern in neonatal intensive care units (NICUs). We describe an outbreak of ESBL-producing K. pneumoniae that lasted 5 months and affected 23 neonates in our NICU. Proton pump inhibitor and extended-spectrum cephalosporin exposure were significantly associated with the risk of ESBL-producing K. pneumoniae colonisation and/or infection. Thirty isolates recovered from clinical, screening and environmental samples in the NICU were studied by means of Raman spectroscopy, pulsed-field gel electrophoresis and repetitive extragenic palindromic polymerase chain reaction (rep-PCR). The Raman clustering was in good agreement with the results of the other two molecular methods. Fourteen isolates belonged to the Raman clone 1 and 16 to the Raman clone 3. Molecular analysis showed that all the strains expressed SHV-1 chromosomal resistance, plasmid-encoded TEM-1 and CTX-M-15 ß-lactamases. Incompatibility groups of plasmid content identified by PCR-based replicon typing indicated that resistance dissemination was due to the clonal spread of K. pneumoniae and horizontal CTX-M-15 gene transfer between the two clones.

Molecular diagnostic analysis of outbreak scenarios.

In the current laboratory assignment, technical aspects of the polymerase chain reaction (PCR) are integrated in the context of six different bacterial outbreak scenarios. The "Enterobacterial Repetitive Intergenic Consensus Sequence" (ERIC) PCR was used to analyze different outbreak scenarios. First, groups of 2-4 students determined optimal ERIC-PCR conditions to validate the protocol and subsequently applied ERIC-PCR to identify genetic relatedness among bacterial strains. Based on these genetic fingerprints, students selected the outbreak cases from the patient samples and assessed the risk factors for the outbreak scenario. Finally, students presented their findings during a classroom presentation. The results indicated that the assignment successfully facilitated student learning on the technical aspects of (ERIC) PCR and clearly demonstrated the practical application of PCR in a clinical diagnostic setting. Additionally, the assignment was highly appreciated by the students.

External quality assessment of the molecular diagnostics and genotyping of meticillin-resistant Staphylococcus aureus.

Two multicentre external quality assessments (EQA) for the molecular detection and genotyping of meticillin-resistant Staphylococcus aureus (MRSA) were arranged. Firstly, 11 samples containing various amounts of inactivated MRSA strains, meticillin-susceptible S. aureus (MSSA), meticillin-resistant coagulase-negative staphylococci (MRCoNS) or Escherichia coli were distributed to 82 laboratories. Samples containing 102 or 103 MRSA cells were correctly scored in only 16 and 46% of the datasets returned, respectively. Two of the used MSSA strains contained an SCCmec cassette lacking the mecA gene. There was a marked difference in the percentage of correct results for these two MSSA strains (37 and 39%) compared to the MSSA strain lacking the SCCmec cassette (88%). Secondly, a panel for MRSA genotyping, consisting of ten samples (two identical, three genetically related and five unique strains) was distributed to 19 laboratories. Seventy-three percent of the datasets recorded all samples correctly. Most pulsed-field gel electrophoresis (PFGE) protocols proved to be suboptimal, resulting in inferior resolution in the higher or lower fragment regions. The performance of molecular diagnostics for MRSA shows no significant changes since our first EQA in 2006. The first molecular typing results are encouraging. Both assessments indicate that programme expansion is required and that major performance discrepancies continue to exist.

Detection of colon flora in peritoneal drain fluid after colorectal surgery: can RT-PCR play a role in diagnosing anastomotic leakage?

A semi-quantitative Real-Time PCR strategy was developed to identify potential indicator organisms for anastomotic leakage in peritoneal drainage fluid, Escherichia coli and Enterococcus faecalis. The analytical performance of the amplification method was validated with 10 culture-positive and 7 culture-negative peritoneal drain fluid samples, obtained from 9 different patients with a colorectal anastomosis. Real-Time PCR results were fully concordant with the microbiological culture results. However, among the culture-negative samples, four false-positive RT-PCR results were found. All false-positives originated from a single patient with a surgical site infection. This may indicate an elevated sensitivity of the RT-PCR method. The results showed that the semi-quantitative RT-PCR method has a clear potential to be useful as a powerful tool in early detection of anastomotic leakage.

Replacement of methicillin-resistant Staphylococcus aureus clones in Hungary over time: a 10-year surveillance study.

The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in Hungary has been increasing and is now close to 20% among invasive isolates of S. aureus. In order to understand the evolution of MRSA in Hungary, two collections of isolates were studied: 22 representatives of a collection of 238 MRSA isolates recovered between 1994 and 1998, and a collection of 299 MRSA isolates recovered between 2001 and 2004. The isolates were first characterised by pulsed-field gel electrophoresis (PFGE) and were distributed into 19 different PFGE patterns. Representatives of each pattern were further characterised by spa typing, multilocus sequence typing (MLST) and staphylococcal cassette chromosome mec (SCCmec) typing. The Hungarian clone that was predominant in 1994-1998 (PFGE E, ST239-III) had almost disappeared in 2003-2004, being replaced by the Southern German clone (PFGE B, ST228-I) and the New York/Japan epidemic clone (PFGE A, ST5-II), which represented c. 85% of the 2001-2004 isolates. Thus, this study describes, for the first time, the co-dominance and extensive spread of the New York/Japan clone in a European country.