Celiac Disease Affects 1% of Global Population-Who Will Manage All These Patients? What Are Criteria to Prioritize Along Risk for Complications?

Celiac disease is a common gastrointestinal condition with an estimated global prevalence of up to 1%. Adequate long-term surveillance of patients is imperative to ensure strict adherence to treatment with a gluten-free diet and the ensuing clinical and histologic recovery. Traditionally, this has been accomplished by means of regular on-site attendance at specialist health care facilities, accompanied for most patients by follow-up endoscopic and laboratory tests. However, the rapidly increasing prevalence of celiac disease and the limited health care resources challenge the current centralized and nonindividualized follow-up strategies. The improved noninvasive surveillance tools and online health care services are further changing the landscape of celiac disease management. There is a clear need for more personalized and on-demand follow-up based on early treatment response and patient-related factors associated with long-term prognosis. Additional scientific evidence on the optimal implementation of follow-up for pediatric and adulthood celiac disease is nevertheless called for.

Health care providers acceptance of default prescribing of TB preventive treatment for people living with HIV in Malawi: a qualitative study

BACKGROUND

Tuberculosis (TB) preventive treatment (TPT) substantially reduces the risk of developing active TB for people living with HIV (PLHIV). We utilized a novel implementation strategy based on choice architecture (CAT) which makes TPT prescribing the default option. Through CAT, health care workers (HCWs) need to "opt-out" when choosing not to prescribe TPT to PLHIV. We assessed the prospective, concurrent, and retrospective acceptability of TPT prescribing among HCWs in Malawi who worked in clinics participating in a cluster randomized trial of the CAT intervention.

METHODS

28 in-depth semi-structured interviews were conducted with HCWs from control (standard prescribing approach) and intervention (CAT approach) clinics. The CAT approach was facilitated in intervention clinics using a default prescribing module built into the point-of-care HIV Electronic Medical Record (EMR) system. An interview guide for the qualitative CAT assessment was developed based on the theoretical framework of acceptability and on the normalization process theory. Thematic analysis was used to code the data, using NVivo 12 software.

RESULTS

We identified eight themes belonging to the three chronological constructs of acceptability. HCWs expressed no tension for changing the standard approach to TPT prescribing (prospective acceptability); however, those exposed to CAT described several advantages, including that it served as a reminder to prescribe TPT and routinized TPT prescribing (concurrent acceptability). Some felt that CAT may reduce HCW´s autonomy and might lead to inappropriate TPT prescribing (retrospective acceptability).

CONCLUSIONS

The default prescribing module for TPT has now been incorporated into the point-of-care EMR system nationally in Malawi. This seems to fit the acceptability of the HCWs. Moving forward, it is important to train HCWs on how the EMR can be leveraged to determine who is eligible for TPT and who is not, while acknowledging the autonomy of HCWs.

A13 THE RATE OF ADVERSE EVENTS AFTER COVID-19 VACCINATION IS SIMILAR IN PATIENTS WITH CELIAC DISEASE AND NON-CELIAC POPULATION: RESULTS OF A LARGE INTERNATIONAL CROSS-SECTIONAL STUDY

Background

Patients with celiac disease (CeD) reported increased COVID-19 vaccine hesitancy due to a fear of adverse events (AEs). However, the risk of AEs post-COVID-19 vaccination in patients with CeD is unknown.

Purpose

To assess whether the rate of common side effects (SEs) and AEs due to COVID vaccines are higher in patients with CeD compared to a non-CeD population.

Method

We conducted a collaborative international cross-sectional study in 16 countries between April 2022 and July 2022. An online survey was distributed to patients with CeD through patients’ local societies, and to non-CeD from the general population in each country through social media posts, word-of-mouth, and through academic institutions. We collected data on participant demographics, medical conditions, CeD diagnosis, GFD adherence, history of COVID-19 vaccinations (type and doses) and self-reported SEs and AEs post-COVID-19 vaccine. SEs included pain/swelling at the site, fatigue, fever, chills, nausea and/or headaches. AEs included thrombosis, myocarditis, anaphylactic reaction, and hospitalization related to the vaccine. Logistic regression models were used to assess predictors such as CeD diagnosis, age, gender, vaccine type and comorbidities on the likelihood of reporting SEs and AEs post-vaccine.

Result(s)

: A total of 17,795 participants completed the survey, 13,638 with CeD (median age of 45[27]) and 4,157 non-CeD controls (median age of 43[20]). There were no significant differences in sex between CeD and controls. Overall, CeD patients had similar odds of SEs compared with non-CeD individuals (aOR=1.02;95% CI=0.92-1.14). SEs were slightly increased only in the second dose of the vaccine in the CeD population compared to non-CeD individuals (aOR= 1.35; 95% CI=1.19-1.53). The most common reported SEs in CeD and controls were pain/swelling at the injection site (29% vs 23 %, p< 0.0001) and fatigue (29% vs 24%, p<0.0001). The odds of SEs were higher with Moderna Spikevax, AstraZeneca/Oxford and Johnson and Johnson vaccines than after the Pfizer vaccine (p< 0.0001). The overall rate of AEs post-vaccine was similar between patients with CeD and non-CeD individuals (aOR= 1.29; 95% CI= 0.89-1.87). Overall, female gender, older age, GFD adherence, respiratory conditions, obesity and receiving immunosuppressive medications increased the odds of SEs, while only age and a history of allergies increased the odds of AEs.

Conclusion(s)

In this large international study, patients with CeD reported similar rates of SEs and AEs post-COVID vaccine compared to non-CeD individuals. This information is highly relevant as it addresses the main concern leading to COVID-19 vaccine hesitancy in CeD patients.

Disclosure of Interest

None Declared

Reducing the burden of TB among migrants to low TB incidence countries

BACKGROUND: International migrants to low TB incidence countries are disproportionately affected by TB compared to the native population: migrants are at increased risk for TB transmission and TB disease due to a variety of personal, environmental and socio-economic determinants experienced during the four phases of migration (pre-departure, transit, arrival and early settlement, return travel).OBJECTIVE: To provide an up-to-date overview of the determinants that drive the TB burden among migrants, as well as effective and feasible interventions to address this for each migration phase.METHODS: We conducted a literature review by searching PubMed and the grey literature for articles and reports on determinants and interventions addressing migrant health and TB.RESULTS: Lowering the risk of TB transmission and TB disease among migrants would be most effective by improving the socio-economic position of migrants pre-, during and after migration, ensuring universal health coverage, and providing tailored and migrant-sensitive care and prevention activities.CONCLUSION: In addition to migrant-sensitive health services and cross-border collaboration between low TB incidence countries, there is a need for international financial and technical support for endemic countries.

Acceptability, feasibility, and likelihood of stakeholders implementing the novel BPaL regimen to treat extensively drug-resistant tuberculosis patients

BACKGROUND

BPaL, a 6 month oral regimen composed of bedaquiline, pretomanid, and linezolid for treating extensively drug-resistant tuberculosis (XDR-TB) is a potential alternative for at least 20 months of individualized treatment regimens (ITR). The ITR has low tolerability, treatment adherence, and success rates, and hence to limit patient burden, loss to follow-up and the emergence of resistance it is essential to implement new DR-TB regimens. The objective of this study was to assess the acceptability, feasibility, and likelihood of implementing BPaL in Indonesia, Kyrgyzstan, and Nigeria.

METHODS

We conducted a concurrent mixed-methods study among a cross-section of health care workers, programmatic and laboratory stakeholders between May 2018 and May 2019. We conducted semi-structured interviews and focus group discussions to assess perceptions on acceptability and feasibility of implementing BPaL. We determined the proportions of a recoded 3-point Likert scale (acceptable; neutral; unacceptable), as well as the overall likelihood of implementing BPaL (likely; neutral; unlikely) that participants graded per regimen, pre-defined aspect and country. We analysed the qualitative results using a deductive framework analysis.

RESULTS

In total 188 stakeholders participated in this study: 63 from Kyrgyzstan, 51 from Indonesia, and 74 from Nigeria The majority were health care workers (110). Overall, 88% (146/166) of the stakeholders would likely implement BPaL once available. Overall acceptability for BPaL was high, especially patient friendliness was often rated as acceptable (93%, 124/133). In contrast, patient friendliness of the ITR was rated as acceptable by 45%. Stakeholders appreciated that BPaL would reduce workload and financial burden on the health care system. However, several stakeholders expressed concerns regarding BPaL safety (monitoring), long-term efficacy, and national regulatory requirements regarding introduction of the regimen. Stakeholders stressed the importance of addressing current health systems constraints as well, especially in treatment and safety monitoring systems.

CONCLUSIONS

Acceptability and feasibility of the BPaL regimen is high among TB stakeholders in Indonesia, Kyrgyzstan, and Nigeria. The majority is willing to start using BPaL as the standard of care for eligible patients despite country-specific health system constraints.

Systematic review with meta-analysis: volatile organic compound analysis to improve faecal immunochemical testing in the detection of colorectal cancer

BACKGROUND

Faecal immunochemical test (FIT) is emerging as a valid test to rule-out the presence of colorectal cancer (CRC). However, the accuracy of FIT is dependent on the cut-off applied. An additional low-cost test could improve further detection of CRC.

AIMS

To evaluate the efficacy of combined FIT and volatile organic compounds (VOC) in the detection of CRC within symptomatic populations.

METHODS

Systematic reviews on the diagnostic accuracy of FIT and VOC, for the detection of CRC, were updated. Meta-analyses were performed adopting a bivariate model for sensitivity and specificity. Clinical utility of combined FIT and VOC was estimated using Fagan's nomogram. Post-test probability of FIT negatives was used as a pre-test probability for VOC.

RESULTS

The pooled sensitivity and specificity of FIT at 10 µg/g faeces, for the detection of CRC, were 0.914 (95% confidence interval [CI] = 0.894-0.936) and 0.783 (CI = 0.850-0.696), respectively. For VOC, the sensitivity was 0.837 (CI = 0.781-0.881) and the specificity was 0.803 (CI = 0.870-0.712). The area under the curve for FIT and VOC were 0.926 and 0.885, respectively. In a population with 5% CRC prevalence, the estimated probability of having CRC following a negative FIT was 0.5% and following both negative FIT and VOC was 0.1%.

CONCLUSIONS

In a FIT-negative symptomatic population, VOC can be a good test to rule-out the presence of CRC. The estimated probability reduction by 0.4% when both tests being negative offers adequate safety netting in primary care for the exclusion of CRC. The number needed to colonoscope to identify one CRC is eight if either FIT or VOC positive. Cost-effectiveness and clinical accuracy of this approach will need further evaluation.

Effects of tetracycline on entomopathogenic nematodes and their bacterial symbionts

Among the new contaminants relevant for environment, one of the most significant roles is played by pharmaceuticals like antibiotic products for either human or veterinary use. Their presence could cause serious damage to bacteria and microfauna, like nematodes. Within the widely investigated nematodes, very little is known about the interaction between antibiotics and entomopathogenic nematodes (EPN). EPNs have been used for biological control of crops, due to their ability to penetrate arthropod pests and kill their hosts thanks to a complex symbiotic mechanism with specific gram-negative bacteria. Tetracycline is an antibiotic used in human and veterinary medicine, both for therapeutic purposes and for the growth of livestock. Since its action against gram-negative bacteria is documented, we verified in this study the survival, growth and pathogenicity of two species of EPNs, Steinernema vulcanicum and S. feltiae. All tests were performed with tetracycline in 1% ethanol solution and up to 300 mg/L. Apparently, this incubation did not harm the vitality of EPNs. Both S. vulcanicum as S. feltiae recovered their vitality and entomopathogenic ability after 48 h. Moreover, the latter EPN species did not grow nor reproduce in the hemolymph of the Greater Wax Moth, Galleria mellonella, and their endosymbionts did not grow on MacConkey Agar. Our results suggest that the first EPN species has always retained all its abilities and that endosymbionts have acquired resistance to tetracycline, while experiments with the second EPN species provided some contrasting results in time that will require further investigations.

The influence of ethnic minority background and migration history on recovery in psychotic disorders: A systematic literature review

Introduction

Recovery in psychotic disorders is a concept that evolved through the last decades. Thanks to the contribution of different researchers, together with the recovery movement, a switch happened from a service-based to a client-based approach towards recovery. The Dutch framework considers recovery as the interplay of symptomatic, personal, functional and societal aspects, determined by different biological, psychological, personal and social factors. Literature on this fourdimensional perspective is still scarce. In addition, even if an increased incidence of psychotic disorders has been recognized in ethnic minority populations and migrants, studies on the influence of ethnicity and migration on recovery in psychotic disorders is limited.

Objectives

To write a systematic literature review on how ethnic minority status and migration history may affect symptomatic, personal, functional and societal recovery.

Methods

A systematic search of the main databases, followed by a four-step selection process to include studies comparing migrants or ethnic minority populations and the non-minoritarian/autochthonous population in terms of recovery. A qualitative, narrative summary has been performed.

Results

Thirty-eight articles have been included. Literature is heterogeneous, focused on clinical outcomes and mostly based on data from the UK and the USA. As a common thread, ethnic minority status and migration history result to negatively influence societal, personal and, to a lower extent, clinical recovery.

Conclusions

Further studies based in different cultural backgrounds and focused on recovery in its multiple aspects are needed, to get a better understanding of the contextual and structural factors that affect the interaction between ethnicity, migration and recovery in psychotic disorders.

Disclosure

No significant relationships.

Preliminary Notes on Equine Tissue Transglutaminase Serology and A Case of Equine Gluten-Sensitive Enteropathy and Dermatitis in an 11-Year-Old Dutch Warmblood Horse

It has been suggested that gluten may play a role in equine inflammatory small bowel disease (ISBD). Previous work showed an association between equine gluten-sensitive enteropathy and IgA antibodies to tissue transglutaminase (TGA) in serum. The purpose of this study is to investigate the prevalence of IgA antibodies to TGA in a group of healthy non-gluten-free sport ponies and to present a case of tentative gluten-sensitive enteropathy and dermatitis in a horse. Blood samples were obtained from 40 healthy jumping ponies. The ponies comprised 12 mares, 8 stallions, and 20 geldings with an average age of 9.0 ± 3.8 years (±SD; range 3-19 years). Sera were tested for IgA antibodies against human recombinant TGA. Significance (P < .05) of the correlation between TGA titer and age in these ponies was assessed using Pearson test (two tailed). In addition, to further illustrate tentative equine gluten-sensitive enteropathy and dermatitis, the clinical course in an 11-year-old Dutch Warmblood sport horse gelding has been described. The average TGA titer was 21.4 ± 13.6 AU/mL (range 2-65 AU/mL). There was a significant (P = .013) correlation (r = 0.389) between age and TGA titer in ponies. One of the 40 ponies (2.5%) showed an elevated TGA titer. An elevated TGA titer decreased after a gluten-free ration for 3 months in an 11-year-old Warmblood gelding with a tentative diagnosis of ISBD associated with full remission of the generalized skin reaction. To our best knowledge, this is the first study assessing TGA antibodies in sera from healthy non-gluten-free ponies and showing a correlation with age. The presented case could be the first one of a horse with a tentative diagnosis of gluten-sensitive enteropathy combined with dermatitis. Given the reported findings, this study warrants further investigations into gluten-sensitive enteropathy and dermatitis in individual horses affected with ISBD.

Tuberculin skin test reaction depends on type of purified protein derivative: implications for cut-off values

SETTING: Due to purified protein derivative (PPD) RT23 stock-outs in 2014, PPD-Tubersol and PPD-Bulbio have been used for latent tuberculosis infection (LTBI) testing in the Netherlands.OBJECTIVE: To determine whether PPD-RT23, PPD-Tubersol and PPD-Bulbio were associated with differential indurations and confirmation using interferon-gamma release assays (IGRAs).DESIGN: LTBI surveillance data from 2013 to 2016 were extracted. Regression analyses were used to determine whether IGRA confirmation of TST-positive indurations depended on PPD, controlling for sex, age, incidence in country of origin, and bacille Calmette-Guérin (BCG) status.RESULTS: A total of 20 956 individuals were tested with PPD-RT23: 10 382 with PPD-Tubersol and 18 562 with PPD-Bulbio. Overall, 21% with PPD-Bulbio had an induration of ≥5 mm compared to 12% of those tested with PPD-RT23 and PPD-Tubersol. Compared to PPD-RT23, PPD-Bulbio indurations ≥5 mm were significantly less often IGRA-confirmed among contacts (aOR 1.3, 95% CI 1.1-1.6) and BCG-vaccinated immigrants (PPD-RT23, aOR 2.4, 95% CI 1.4-4.1). Increasing the PPD-Bulbio cut-off from ≥5 to ≥10 mm would save respectively 26%, 42%, and 35% of IGRAs among contacts, health care workers (HCWs) and BCG-vaccinated immigrants, with small absolute numbers of positive IGRAs missed (range 0-55 annually).CONCLUSION: PPD-Bulbio shows larger TST indurations than other PPDs, but is less often IGRA-confirmed. Increasing the TST cut-off from 5 to 10 mm prior to testing with an IGRA in HCWs and immigrants is recommended.

Faecal volatile organic compounds analysis using field asymmetric ion mobility spectrometry: non-invasive diagnostics in paediatric inflammatory bowel disease

BACKGROUND AND OBJECTIVES

Inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), remains challenging to diagnose. Diagnostic work-up carries a high burden, especially in paediatric patients, due to invasive endoscopic procedures. IBD is associated with alterations in intestinal microbiota composition. Faecal volatile organic compounds (VOCs) reflect gut microbiota composition. The aim of this study was to assess the diagnostic accuracy of faecal VOC profiling as a non-invasive diagnostic biomarker for paediatric IBD.

METHODS

In this diagnostic accuracy study performed in two tertiary centres in the Netherlands, faecal VOC profiles of 36 de novo, treatment-naïve paediatric IBD patients (23 CD, 13 UC), and 24 healthy, matched controls were measured by field asymmetric ion mobility spectrometry (Owlstone Ltd, Lonestar®, UK).

RESULTS

Faecal VOC profiles of de novo paediatric IBD patients could be differentiated from healthy controls (AUC ± 95% CI, p-value, sensitivity, specificity; 0.76 ± 0.14, p < 0.001, 79%, 78%). This discrimination from controls was observed in both CD (0.90 ± 0.10, p < 0.0001, 83%, 83%) and UC (0.74 ± 0.19, p = 0.02, 77%, 75%). VOC profiles from UC could not be discriminated from CD (0.67 ± 0.19, p = 0.0996, 65%, 62%).

CONCLUSION

Field asymmetric ion mobility spectrometry allowed for discrimination between faecal VOC profiles of de novo paediatric IBD patients and healthy controls, confirming the potential of faecal VOC analysis as a non-invasive diagnostic biomarker for paediatric IBD. This method may serve as a complementary, non-invasive technique in the diagnosis of IBD, possibly limiting the number of endoscopies needed in children suspected for IBD.

Serial Microbiota Analysis after Fecal Microbiota Transplantation in a Child with Down's Syndrome

Fecal microbiota transplantation (FMT) is a very effective treatment for recurrent Clostridium difficile infection (CDI) in adults. However, there is a paucity of data on FMT in children and associated microbiome changes in this particular group. We describe a child with Down's syndrome and intracranial malignancy, who received FMT for recurrent CDI. Detailed microbiota analysis before and after FMT, and pre- and post-recurrence, linked to microbial communities in the donor feces showed that the patient developed a unique microbiota profile after FMT which was very stable over time despite CDI recurrence and subsequent fidaxomicin therapy. Bacteroidetes were stably acquired from donor feces, while Firmicutes, Actinobacteria, Fusobacteria, Verrucomicrobia, and Proteobacteria were unique to the patient. The diversity of microbiota of the patient increased from a Shannon diversity index of 2.08 pre-FMT to 3.12 post-FMT. Our findings underscore that patients with Down's syndrome may well tolerate and benefit from FMT even in a severely immunocompromised state.

Low FODMAP diet efficacy in IBS patients-what is the evidence and what else do we need to know?

Irritable Bowel Syndrome (IBS) is a common and significant health problem which may be treatable with dietary interventions. Here we aim to explain the principles of the low Fermentable Oligo-, Di-, Monosaccharides and Polyol diet, and discuss both the limitations and opportunities of the diet in those with IBS, a common cause of presentation to primary and secondary care in New Zealand.

The composition and differentiation potential of the duodenal intraepithelial innate lymphocyte compartment is altered in coeliac disease

OBJECTIVE

Coeliac disease (CD), a gluten-induced enteropathy, alters the composition and function of duodenal intraepithelial T cells. The intestine also harbours four types of CD3-negative intraepithelial lymphocytes (IELs) with largely unknown function: CD56(-)CD127(-), CD56(-)CD127(+), CD56(+)CD127(-) and CD56(+)CD127(+). Here we aimed to gain insight into the potential function of these innate IELs in health and disease.

DESIGN

We determined the phenotypes, relative abundance and differentiation potential of these innate IEL subsets in duodenal biopsies from controls and patients with CD or patients with refractory CD type II (RCDII).

RESULTS

Hierarchical clustering analysis of the expression of 15 natural killer and T cell surface markers showed that innate IELs differed markedly from innate peripheral blood lymphocytes and divided innate IEL subsets into two main branches: a CD127(-) branch expressing high levels of interleukin (IL) 2/15Rβ but no IL-21R, and a CD127(+) branch with the opposite phenotype. While CD was characterised by the contraction of all four innate IEL subsets, a selective expansion of CD56(-)CD127(-) and CD56(-)CD127(+) innate IEL was detected in RCDII. In vitro, in the presence of IL-15, CD56(-)CD127(-) IEL from controls and patients with CD, but not from patients with RCDII, differentiated into functional natural killer and T cells, the latter largely dependent on notch-signalling. Furthermore, compared with non-coeliac controls, CD56(-)CD127(-) IEL from patients with CD expressed more intracellular CD3ε and CD3γ and gave more pronounced T cell differentiation.

CONCLUSIONS

Thus, we demonstrate previously unappreciated diversity and plasticity of the innate IEL compartment and its loss of differentiation potential in patients with RCDII.

Abstract 3176: Improved colorectal cancer screening by new stool-based protein markers

Background

The fecal immunochemical test (FIT) is used in many countries for non-invasive screening for colorectal cancer (CRC), but its characteristics leave room for improvement. We aimed to identify novel stool-based protein markers in stool that outperform or complement hemoglobin in detecting CRC.

Materials and methods

A series of large scale proteomic discovery and validation was conducted on a total of 313 human stool specimens. A discovery set consisted of 22 stool specimens (12 CRC and 10 controls), and isolated proteins were analyzed by an in-dept mass spectrometry GeLC-MS/MS workflow. An external validation set consisted of 291 independent stool specimens (79 CRC, 40 advanced adenoma (AA), 43 nonadvanced adenoma (A) and 129 controls), and isolated proteins were analyzed by single-shot mass spectrometry (Q-Exactive). As proof of concept, commercially available meso scale discovery (MSD) assays were performed on an independent validation set of 72 FIT fluid samples set including 14 CRC, 16 AA, 18 A and 24 controls.

Results

Of the 468 human proteins quantified in the discovery set, 93 were significantly enriched in CRC vs controls (p&lt;0.05). Of these, 29 were significantly found enriched in CRC vs controls in the validation set (q&lt;0.05). CART analysis and exhaustive search revealed a combination of 4 proteins as the most optimal combination to differentiate CRC from controls. A logistic regression model of this combination of proteins detected CRC with a sensitivity of 73% as compared to 43% for hemoglobin (HBA1) alone at a fixed specificity of 95% (p = 0.00003). Another combination of 4 proteins was the most optimal combination to differentiate AA from controls, which showed a sensitivity of 48% vs 8% for hemoglobin (p = 0.0002) at fixed specificity of 95%. Evaluation of one of the markers on FIT fluid samples provided proof of concept that these proteins can be detected in FIT fluid and can significantly discriminate CRC from healthy controls (p &lt; 0.001).

Conclusion

Proteome profiling on stool samples revealed 29 validated proteins significantly enriched in CRC samples compared to controls. A panel of 4 complementary protein markers outperformed hemoglobin for detection of CRC as well as AA. Proof of concept for detecting the proteins in FIT fluids confirmed the high potential of these markers for screening purposes in a non-invasive and cost-effective manner.

Citation Format: Linda J. Bosch, Meike De Wit, Annemieke C. Hiemstra, Sander R. Piersma, Thang V. Pham, Gideon Oudgenoeg, Veerle Coupe, George Scheffer, Sandra Mongera, Jochim Terhaar Sive droste, Frank Oort, Sietze van Turenhout, Ilhame Ben Larbi, Chris Mulder, Beatriz Carvalho, Remond JA Fijneman, Connie R. Jimenez, Gerrit A. Meijer. Improved colorectal cancer screening by new stool-based protein markers. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3176.

Time-place learning and memory persist in mice lacking functional Per1 and Per2 clock genes

With time-place learning, animals link a stimulus with the location and the time of day. This ability may optimize resource localization and predator avoidance in daily changing environments. Time-place learning is a suitable task to study the interaction of the circadian system and memory. Previously, we showed that time-place learning in mice depends on the circadian system and Cry1 and/or Cry2 clock genes. We questioned whether time-place learning is Cry specific or also depends on other core molecular clock genes. Here, we show that Per1/Per2 double mutant mice, despite their arrhythmic phenotype, acquire time-place learning similar to wild-type mice. As well as an established role in circadian rhythms, Per genes have also been implicated in the formation and storage of memory. We found no deficiencies in short-term spatial working memory in Per mutant mice compared to wild-type mice. Moreover, both Per mutant and wild-type mice showed similar long-term memory for contextual features of a paradigm (a mild foot shock), measured in trained mice after a 2-month nontesting interval. In contrast, time-place associations were lost in both wild-type and mutant mice after these 2 months, suggesting a lack of maintained long-term memory storage for this type of information. Taken together, Cry-dependent time-place learning does not require Per genes, and Per mutant mice showed no PER-specific short-term or long-term memory deficiencies. These results limit the functional role of Per clock genes in the circadian regulation of time-place learning and memory.

Fine mapping of the celiac disease-associated LPP locus reveals a potential functional variant

Using the Immunochip for genotyping, we identified 39 non-human leukocyte antigen (non-HLA) loci associated to celiac disease (CeD), an immune-mediated disease with a worldwide frequency of ∼1%. The most significant non-HLA signal mapped to the intronic region of 70 kb in the LPP gene. Our aim was to fine map and identify possible functional variants in the LPP locus. We performed a meta-analysis in a cohort of 25 169 individuals from six different populations previously genotyped using Immunochip. Imputation using data from the Genome of the Netherlands and 1000 Genomes projects, followed by meta-analysis, confirmed the strong association signal on the LPP locus (rs2030519, P = 1.79 × 10(-49)), without any novel associations. The conditional analysis on this top SNP-indicated association to a single common haplotype. By performing haplotype analyses in each population separately, as well as in a combined group of the four populations that reach the significant threshold after correction (P < 0.008), we narrowed down the CeD-associated region from 70 to 2.8 kb (P = 1.35 × 10(-44)). By intersecting regulatory data from the ENCODE project, we found a functional SNP, rs4686484 (P = 3.12 × 10(-49)), that maps to several B-cell enhancer elements and a highly conserved region. This SNP was also predicted to change the binding motif of the transcription factors IRF4, IRF11, Nkx2.7 and Nkx2.9, suggesting its role in transcriptional regulation. We later found significantly low levels of LPP mRNA in CeD biopsies compared with controls, thus our results suggest that rs4686484 is the functional variant in this locus, while LPP expression is decreased in CeD.

Effects of copper on invertebrate-sediment interactions

Toxicants potentially decouple links between biodiversity and ecosystem processes. This study aimed to evaluate how toxicants affect invertebrate bioturbation and decomposition. Effects of copper on functionally distinct macrofaunal species (Asellus aquaticus and Tubifex spp.), decomposition (release of dissolved organic carbon, DOC) and Average Metabolic Response (AMR) and Community Metabolic Diversity (CMD) of bacteria were determined in 5-day microcosm experiments. Bioturbation was assessed as sediment redox potential (Eh) profiles. Concentration-response curves of the functional parameters DOC, and the faunal mediated AMR and CMD in the presence of Tubifex spp. depended on Tubifex spp. survival, i.e. similar EC50 values for both endpoints. In contrast, functional parameters in the presence of A. aquaticus were more sensitive than survival. Sediment Eh-profiles showed that reduced decomposition was caused by reduced sediment reworking by A. aquaticus at sub-lethal copper concentrations. These observations hint at a decoupling of invertebrate community structure and ecosystem functioning upon stress.

A method to assess ecosystem services developed from soil attributes with stakeholders and data of four arable farms

Ecosystem-service indicators and related accounting units are crucial for the development of decision frameworks for sustainable land management systems. With a management concept using ecosystem services, land-use expectations can be linked to quantifiable soil features in a defendable and transparent way. A method to define a set of site-specific ecosystem services and indication system for quantification was set-up and run. First, we interviewed a wide group of land users profiting from ecosystem services of the soil at four arable farms in the polder Hoeksche Waard (S-SE of Rotterdam, the Netherlands). Subsequently, site-specific ecosystem services were defined and weighted according to land use expectations at different spatial and temporal scales. Second, a practical set of indicators was taken from 'Best Professional Judgment' and used to quantify the performance of the ecosystem services for these four farms. The indicators were derived from biotic and abiotic soil parameters. The performance of ecosystem services was related to a reference situation (MEP: maximum ecological potential) with the same land use and soil type combination (i.e., arable fields on silt loam) taken from the database of our national soil survey. In many cases, the performance of ecosystem services was relatively poor if compared to MEP. However, the performances of natural attenuation and/or climate-related services were better. In addition, the different management of these farms (i.e. conventional, intensive and organic farming) was reflected in the performance of the ecosystem services of their soils. Third, land management measures to improve the targeted ecosystem services were incorporated in the outlined method, but not worked out with illustrative field data in this study. Together with concordant data, we show opportunities for a quantification of ecosystem services to improve land-users' awareness and to assess management sustainability.

How to calculate the spatial distribution of ecosystem services--natural attenuation as example from The Netherlands

Maps play an important role during the entire process of spatial planning and bring ecosystem services to the attention of stakeholders' negotiation more easily. As example we show the quantification of the ecosystem service 'natural attenuation of pollutants', which is a service necessary to keep the soil clean for production of safe food and provision of drinking water, and to provide a healthy habitat for soil organisms to support other ecosystem services. A method was developed to plot the relative measure of the natural attenuation capacity of the soil in a map. Several properties of Dutch soils were related to property-specific reference values and subsequently combined into one proxy for the natural attenuation of pollutants. This method can also be used to map other ecosystem services and to ultimately integrate suites of ecosystem services in one map.

Estrogen receptor-β signaling modulates epithelial barrier function

Impaired epithelial barrier function and estrogens are recognized as factors influencing inflammatory bowel disease (IBD) pathology and disease course. Estrogen receptor-β (ERβ) is the most abundant estrogen receptor in the colon and a complete absence of ERβ expression is associated with disrupted tight-junction formation and abnormal colonic architecture. The aim of this study was to determine whether ERβ signaling has a role in the maintenance of epithelial permeability in the colon. ERβ mRNA levels and colonic permeability were assessed in IL-10-deficient mice and HLA-B27 rats by RT-PCR and Ussing chambers. ERβ expression and monolayer resistance were measured in HT-29 and T84 colonic epithelial monolayers by RT-PCR and electric cell-substrate impedance sensing. The effect of 17β-estradiol and an estrogen agonist [diarylpropionitrile (DPN)] and antagonist (ICI 182780) on epithelial resistance in T84 cells was measured. Expression of ERβ and proinflammatory cytokines was investigated in colonic biopsies from IBD patients. Levels of ERβ mRNA were decreased, whereas colonic permeability was increased, in IL-10-deficient mice and HLA-B27 transgenic rats prior to the onset of colitis. T84 cells demonstrated higher resistance and increased levels of ERβ mRNA compared with HT-29 cells. 17β-estradiol and DPN induced increased epithelial resistance in T84 cells, whereas an ERβ blocker prevented the increased resistance. Decreased ERβ mRNA levels were observed in colonic biopsies from IBD patients. This study suggests a potential role for ERβ signaling in the modulation of epithelial permeability and demonstrates reduced ERβ mRNA in animal models of colitis and colon of patients with inflammatory bowel disease.

JS02-04 - The organisation of emergency psychiatry in The Netherlands

Introduction

The organisation of emergency psychiatry varies between European countries. Our aim is to describe the organisation of emergency psychiatry in the Netherlands, including relevant epidemiological data.

Methods

The organisation of emergency psychiatry in the Netherlands was assessed using written material, official statistics and a recent study about the organisation of outpatient crisis services.

Results

In the Netherlands, most psychiatric emergency services are being delivered by three levels of care: primary care physicians, outpatient crisis services and inpatient admission units. The outpatient psychiatric crisis services constitute the key factor in the emergency psychiatric care, as they do most assessments (triage), short term crisis interventions and referral. Outpatient crisis services are available 24/7, and are mainly staffed by physicians (including psychiatrists) and psychiatric nurses. Usually, patients first consult a primary care physician in case of a psychiatric crisis situation, which can be followed by a referral to an outpatient emergency crisis service in the local region. Patients can also be referred by mental health clinicians (for example for triage for involuntary admission), the police or emergency departments of general hospitals. The outpatient crisis services perform diagnostic and risk assessments (triage), short term crisis interventions, and decide on referral to other services. These can be specialized outpatient programs or (in)voluntary admission to a psychiatric hospital. The number of crisis contacts per 100.000 inhabitants varies between regions, depending e.g. on population density. For example 400 crisis contacts per 100.000 inhabitants were registered in 2003 in the urban region of The Hague, versus 200 per 100.000 in a surrounding rural area. As a mean 20% of patients are being referred to a psychiatric hospital, half of them involuntarily. The number of crisis contacts, voluntary admissions, as well as involuntary admissions rises steadily in The Netherlands. In 1978, 17 per 100.000 inhabitants were admitted involuntarily, as compared to 50 in 2009. Reasons for involuntary admission include self harm, harm to others and severe self neglect. Involuntary admission for reason of severe self neglect is increasing over the last ten years. As a seperate phenomenon, ethnic minority groups, especially from Antillean, Surinam and Moroccan descent, are over-representated in outpatient as well as inpatient emergency services in the urban areas.

Conclusion

Outpatient crisis services constitute the key factor in the organisation of emergency psychiatric services in The Netherlands. The last decade, the number of crisiscontacts, as well as the number of (in)voluntary admissions did rise.

Effectiveness of tuberculosis contact tracing among migrants and the foreign-born population

A literature review was performed to assess the effectiveness of tuberculosis (TB) contact tracing among migrants and the foreign-born population with emphasis on the European Union. Effectiveness of contact tracing was assessed using the following indicators: coverage, proportion of contacts with TB (TB yield), proportion of contacts with latent tuberculosis infection (LTBI yield) and number of investigated contacts per index case (contacts/index case ratio). The key findings from the literature review were: Among foreign-born contacts, a higher median LTBI yield was found compared with contacts born in the country, when exposed to the same foreign-born index cases. No clear differences were observed between TB and LTBI yield among contacts of foreign-born index cases compared with contacts of index cases from the general population (including the foreign-born) due to the large variation seen between the studies. The included non-European studies screened more contacts per foreign-born index case, used lower cut-off values to define a positive tuberculosis skin test and found higher LTBI yields among contacts. Although the high heterogeneity across the studies made the comparison challenging, several conclusions are made regarding contact tracing among migrants.

Effectiveness of tuberculosis contact tracing among migrants and the foreign-born population

A literature review was performed to assess the effectiveness of tuberculosis (TB) contact tracing among migrants and the foreign-born population with emphasis on the European Union. Effectiveness of contact tracing was assessed using the following indicators: coverage, proportion of contacts with TB (TB yield), proportion of contacts with latent tuberculosis infection (LTBI yield) and number of investigated contacts per index case (contacts/index case ratio). The key findings from the literature review were: Among foreign-born contacts, a higher median LTBI yield was found compared with contacts born in the country, when exposed to the same foreign-born index cases. No clear differences were observed between TB and LTBI yield among contacts of foreign-born index cases compared with contacts of index cases from the general population (including the foreign-born) due to the large variation seen between the studies. The included non-European studies screened more contacts per foreign-born index case, used lower cut-off values to define a positive tuberculosis skin test and found higher LTBI yields among contacts. Although the high heterogeneity across the studies made the comparison challenging, several conclusions are made regarding contact tracing among migrants.

Tracking of childhood overweight into adulthood: a systematic review of the literature

Overweight and obesity in youth are important public health concerns and are of particular interest because of possible long-term associations with adult weight status and morbidity. The aim of this study was to systematically review the literature and update evidence concerning persistence of childhood overweight. A computerized bibliographical search--restricted to studies with a prospective or retrospective longitudinal design--was conducted. Two authors independently extracted data and assessed the methodological quality of the included studies in four dimensions (i) study population and participation rate; (ii) study attrition; (iii) data collection and (iv) data analysis. Conclusions were based on a rating system of three levels of evidence. A total of 25 publications were selected for inclusion in this review. According to a methodological quality assessment, 13 studies were considered to be of high quality. The majority of these high-quality studies were published after 2001, indicating that recently published data, in particular, provide us with reliable information. All included studies consistently report an increased risk of overweight and obese youth becoming overweight adults, suggesting that the likelihood of persistence of overweight into adulthood is moderate for overweight and obese youth. However, predictive values varied considerably. Limiting aspects with respect to generalizability and methodological issues are discussed.

Decreased cerebrospinal fluid amyloid beta (1-40) levels in frontotemporal lobar degeneration

The role of amyloid metabolism in the pathophysiology of frontotemporal lobar degeneration (FTLD) has yet to be elucidated. We compared CSF levels of amyloid beta 1-40 (Abeta40) and amyloid beta 1-42 (Abeta42) in patients with FTLD (n = 21) versus patients with Alzheimer's disease (AD, n = 39) and in control subjects (n = 30). While in AD cases Abeta42 levels were lower and CSF Abeta40 levels equal to those in controls, a significant decrease in Abeta40 and increase in the CSF Abeta42/Abeta40 ratio was observed in FTLD compared with AD and control subjects. These findings favour a differential involvement of amyloid beta peptides in FTLD compared with AD.

Abdominal computed tomography in refractory coeliac disease and enteropathy associated T-cell lymphoma

AIM: To evaluate computed tomography (CT) findings, useful to suggest the presence of refractory celiac disease (RCD) and enteropathy associated T cell lymphoma (EATL).

METHODS: Coeliac disease (CD) patients were divided into two groups. GroupI: uncomplicated CD (n = 14) and RCD typeI(n = 10). Group II: RCD type II (n = 15) and EATL (n = 7).

RESULTS: Both groups showed classic signs of CD on CT. Intussusception was seen in 1 patient in groupIvs 5 in group II (P = 0.06). Lymphadenopathy was seen in 5 patients in group II vs no patients in groupI(P = 0.01). Increased number of small mesenteric vessels was noted in 20 patients in groupIvs 11 in group II (P = 0.02). Eleven patients (50%) in group II had a splenic volume < 122 cm³vs 4 in groupI(14%), 10 patients in groupI had a splenic volume > 196 cm³ (66.7%) vs 5 in group II (33.3%) P = 0.028.

CONCLUSION: CT scan is a useful tool in discriminating between CD and (Pre) EATL. RCD II and EATL showed more bowel wall thickening, lymphadenopathy and intussusception, less increase in number of small mesenteric vessels and a smaller splenic volume compared with CD and RCDI.

The downstream modulator of interferon-γ, STAT1 is not genetically associated to the Dutch coeliac disease population

Coeliac disease (CD) is a complex genetic disorder. Its etiology is owing to multiple genes and environmental factors, such as gluten. The first event in the pathogenesis of CD after the ingestion of gluten is the activation of a Th1 immune response that leads to villous atrophy. Although this immune response seems crucial to the disease's development, only the HLA-DQ2/DQ8 genes have been identified as causative immune genes related to CD. Recently, the activation of the transcription factor STAT1 and changes in its expression levels have confirmed the participation of the Janus kinase-signal transducer and activator of transcription pathway in CD. Furthermore, as the STAT-1 gene is a positional candidate located in the CELIAC3 locus on chromosome 2, we speculate that alterations in this gene could be primarily responsible for the aberrant immune response that characterizes CD. Based on this functional and genetic evidence, we investigated the primary contribution of STAT-1 to CD. We performed a comprehensive genetic association study using five tag SNPs fully covering the STAT-1 gene in a Dutch cohort of 355 independent CD cases and 360 healthy controls. Neither the alleles, nor the genotypes in the case-control genetic association studies, nor the haplotype analysis showed any association to the STAT-1 gene in the Dutch CD population. Our results do not point to a primary involvement of the STAT-1 gene in the Dutch CD population.

CSF biomarkers in frontotemporal lobar degeneration: relations with clinical characteristics, apolipoprotein E genotype, and neuroimaging

In order to better understand the large variation in cerebrospinal fluid (CSF) tau and amyloid-beta(1-42) (Abeta42) in frontotemporal lobar degeneration (FTLD), relations between these biomarkers and clinical parameters, neuroimaging characteristics, and apolipoprotein E (ApoE) genotype were studied in 31 patients with FTLD, including 16 patients with the frontal variant and 15 with the temporal variant. CSF tau was highest in FTLD with predominant temporal involvement. In the frontal subgroup, CSF tau level was influenced by the number of ApoE epsilon3 alleles. In the temporal subgroup, CSF tau level was dependent on a combination of CSF Abeta42, age, disease duration, and disease severity. No relation with degree of atrophy or asymmetry on neuroimaging could be established. CSF Abeta42 variability remained unexplained. Future research could study the role of ApoE genotype and Abeta42 in FTLD, as well as establish measures for disease intensity.

Biomarker profiles and their relation to clinical variables in mild cognitive impairment

The aim of the study was to compare clinical variables between MCI patients at different risk for Alzheimer's disease (AD) according to their biomarker profile. Fifty-four percent out of 39 MCI patients had a low Abeta42 and high tau in cerebrospinal fluid (CSF) (high-risk), 26% either a low CSF Abeta32 or high CSF tau (intermediate-risk) and 20% a normal CSF Abeta42 and tau (low-risk). Both high-and intermediate-risk subjects differed from the low-risk group in episodic memory, executive functions and the preclinical AD scale (PAS),which combines a set of clinical parameters. Subjects at high risk did not differ from subjects with an intermediate risk. Abeta42 levels correlated with the MTA and PAS scores, tau levels with episodic memory. These correlations suggest that the biomarkers are not independent when compared to the other AD markers. Longitudinal studies are necessary to interpret the correlations between biomarkers, imaging, and neuropsychological markers.

Amyloid beta(1-42) and phosphorylated tau in CSF as markers for early-onset Alzheimer disease

OBJECTIVE

To determine the diagnostic value of CSF amyloid beta(1-42) (Abeta42), CSF total tau, and CSF tau phosphorylated at threonine-181 (Ptau-181) in early-onset Alzheimer disease (EAD) vs frontotemporal lobar degeneration (FTLD).

METHODS

Levels of Abeta42, total tau, and Ptau-181 in CSF were measured using commercially available ELISA in 47 EAD patients, 28 FTLD patients, and 21 nondemented control subjects.

RESULTS

CSF Abeta42 was significantly lower and CSF total tau and CSF Ptau-181 significantly higher in EAD patients than FTLD patients and control subjects. There was an increase in diagnostic accuracy for CSF Ptau-181 vs CSF total tau (p = 0.067). Combining low CSF Abeta42 and high CSF Ptau-181 allowed EAD patients to be distinguished from FTLD patients with a sensitivity of 72% and a specificity of 93%. Logistic regression analysis with CSF Abeta42 and CSF Ptau-181 as independent continuous variables resulted in correct classification of 46 of 47 (98%) EAD patients and 23 of 28 (82%) FTLD patients. The diagnostic accuracy for EAD was independent of gender, disease duration, and disease severity.

CONCLUSION

The combination of CSF Abeta42 and CSF Ptau-181 may help in differentiating EAD from FTLD.

Decreased lysophosphatidylcholine/phosphatidylcholine ratio in cerebrospinal fluid in Alzheimer's disease

Choline containing phospholipids are essential for the integrity of the'cell'membrane. Minor changes in the lysophosphatidylcholine (lyso-PC)/phosphatidylcholine (PC) ratio may lead to neuronal damage and cell loss. Several studies have shown protein and lipid oxidation in Alzheimer's disease (AD) affected brain regions. Amyloid-beta peptides may induce free-radical oxidative stress which normally is counteracted by anti-oxidant defense mechanisms. We hypothesize that oxidation may lead to changed concentrations of choline containing phospholipids in cerebrospinal fluid (CSF) of AD patients, because of the susceptibility of the unsaturated acyl-chains of PC for oxidation. PC and lyso-PC were determined in CSF of AD patients (n=19) and subjects with subjective memory complaints without dementia (n=19) by tandem mass spectrometry. No differences in total PC concentrations were observed between both study groups. Furthermore, we could not demonstrate different concentrations of PC species containing linoleic acid and PC species containing arachidonic acid. Interestingly, lyso-PC concentrations tended to be lower while the lyso-PC/PC ratio was significantly decreased in CSF of AD patients compared to controls (0.36% versus 0.54%; P=0.017). A comparable decrease was found for the lyso-PC/PC ratio for PC containing linoleic acid (P=0.022) or arachidonic acid (P=0.010), respectively. The lower lyso-PC/PC ratio in CSF of patients with AD may reflect alterations in the metabolism of choline-containing phospholipids in the brain in AD, and suggests that PC species containing linoleic acid or arachidonic acid are equally involved.

The prevalence of coeliac disease at endoscopy units in Romania: routine biopsies during gastroscopy are mandatory (a multicentre study)

The incidence and prevalence of coeliac disease vary internationally. In Eastern Europe little is known about the prevalence of coeliac disease.

THE AIM

of this study was to evaluate the prevalence and the clinical features of coeliac disease in adults biopsied during upper endoscopy in Romania. This is the first incidence study of the coeliac disease in Romania.

METHODS

The study was initiated by the Romanian Society of Digestive Endoscopy for the period 1 January 2002 - 31 May 2002. It was carried out in 9 Academic Centres in Romania, which ensured an even geographical distribution and therefore significant statistical results at a national level. The study included 2436 patients according to following criteria: age over 16 years, with no known history of coeliac disease, visiting the participating upper endoscopy units or patients with documented coeliac disease presenting for follow-up check or recurrence of clinical symptoms. At least two bioptic samples were obtained from the distal duodenum, as distally as possible, which were submitted to histopathological examination and scored according to the modified UEGW Marsh criteria (2001). A database was set up to include all the patients with data regarding sex, age, urban or rural background, full clinical diagnosis, clinical symptoms, history of the coeliac disease.

RESULTS

Of the 2436 patients studied, 54 (2.22%) were diagnosed with coeliac disease. Their demographic features: 48.15% men, 51.85% women, 68.52% living in urban areas, 31.48% in rural ones, mean age 42 +/-17.0 years. The most frequent reasons for performing upper digestive endoscopy were: dyspeptic syndrome - 15.93%, anemia - 24.07%, and chronic diarrhoea - 22.22%. The most frequently recorded clinical manifestations were: chronic diarrhoea in 46.3%, asthenia in 29.63%, anemia in 24.07%, aphthae in 24.07%. Histopathological results according to Marsh classification were: Marsh III- 64.81 %, Marsh II-35.19%.

CONCLUSIONS

The prevalence of the coeliac disease in Romania is 2.22%: its sex distribution is fairly equal, the age distribution includes two peaks, at 30-40 and 50-60 years respectively, and patients from urban areas predominate. The most frequent (over 50% of the cases) histological type was M III. The most common clinical symptoms were diarrhoea, asthenia, anemia, aphthae, while the most frequent associated diseases were diabetes mellitus and Duhring-Brocq dermatiti

CSF markers related to pathogenetic mechanisms in Alzheimer's disease

Serum amyloid P component (SAP) and complement C1q are found highly co-localized with extracellular fibrillar amyloidbeta (Abeta) deposits in Alzheimer's disease (AD) brain. Conflicting data were reported earlier about the cerebrospinal fluid (CSF) levels of SAP and C1q in AD compared to controls. The objective of the present study was to compare the levels of Abeta(1-42), tau, C1q and SAP in CSF of a well characterized group of AD patients and controls, and to assess the association with dementia severity. Significantly decreased CSF levels of Abeta(1-42) were observed in the AD group (480 +/- 104 ng/L) as compared to controls (1,040 +/- 213 ng/L), whereas tau levels were significantly higher in patients with AD (618 +/- 292 ng/L) than in controls (277 +/- 136 ng/L). Combining the results of Abeta(1-42) and tau measurements resulted in a clear separation between the AD group and the controls. No significant differences in CSF levels of SAP and C1q were observed between the well characterized AD patients and non demented control group. Furthermore, we could not demonstrate a correlation between SAP and C1q CSF levels and the severity of the disease, expressed in Mini-Mental State Examination (MMSE) scores. Therefore, in our opinion these factors can be excluded from the list of potentially interesting biomarkers for AD diagnosis and progression.

Alzheimer's disease is not associated with altered concentrations of the nitric oxide synthase inhibitor asymmetric dimethylarginine in cerebrospinal fluid

Nitric oxide (NO) may play a role in the pathophysiology of Alzheimer's disease (AD). Asymmetric dimethylarginine (ADMA), an endogenous inhibitor of NO synthase, is involved in regulation of NO production. Recently it has been reported that dimethylarginine dimethylaminohydrolase, an enzyme that hydrolyses ADMA into citrulline and dimethylamine, is specifically elevated in neurons displaying cytoskeletal abnormalities and oxidative stress in AD. We hypothesized that this could lead to altered CSF concentrations of ADMA in AD. Measurement of ADMA and dimethylamine in CSF revealed no significant differences between AD patients (n = 20) and age-matched control subjects (n = 20). Our results suggest that in early stages of AD overall regulation of NO production by ADMA is not aberrant.

Quantitative analysis of Penicillium chrysogenum Wis54-1255 transformants overexpressing the penicillin biosynthetic genes

The low penicillin-producing, single gene copy strain Wis54-1255 was used to study the effect of overexpressing the penicillin biosynthetic genes in Penicillium chrysogenum. Transformants of Wis54-1255 were obtained with the amdS expression-cassette using the four combinations: pcbAB, pcbC, pcbC-penDE, and pcbAB-pcbC-penDE of the three penicillin biosynthetic genes. Transformants showing an increased penicillin production were investigated during steady-state continuous cultivations with glucose as the growth-limiting substrate. The transformants were characterized with respect to specific penicillin productivity, the activity of the two pathway enzymes delta-(L-alpha-aminoadipyl)-L-cysteinyl-D-valine synthetase (ACVS) and isopenicillin N synthetase (IPNS) and the intracellular concentration of the metabolites: delta-(L-alpha-aminoadipyl)-L-cysteinyl-D-valine (ACV), bis-delta-(L-alpha-aminoadipyl)-L-cysteinyl-D-valine (bisACV), isopenicillin N (IPN), glutathione (GSH), and glutathione disulphide (GSSG). Transformants with the whole gene cluster amplified showed the largest increase in specific penicillin productivity (r(p))-124% and 176%, respectively, whereas transformation with the pcbC-penDE gene fragment resulted in a decrease in r(p) of 9% relative to Wis54-1255. A marked increase in r(p) is clearly correlated with a balanced amplification of both the ACVS and IPNS activity or a large amplification of either enzyme activity. The increased capacity of a single enzyme occurs surprisingly only in the transformants where all the three biosynthetic genes are overexpressed but is not found within the group of pcbAB or pcbC transformants. The indication of the pcbAB and pcbC genes being closely regulated in fungi might explain why high-yielding strains of P. chrysogenum have been found to contain amplifications of a large region including the whole penicillin gene cluster and not single gene amplifications. Measurements of the total ACV concentration showed a large span of variability, which reflected the individual status of enzyme overexpression and activity found in each strain. The ratio ACV:bisACV remained constant, also at high ACV concentrations, indicating no limitation in the capacity of the thioredoxin-thioredoxin reductase (TR) system, which is assumed to keep the pathway intermediate LLD-ACV in its reduced state. The total GSH pool was at a constant level of approx. 5.7 mM in all cultivations.