Results of an international interlaboratory study on dioxin-like activities in drinking-, river surface- and wastewater using DR CALUX bioassay

Aquatic animals and consumers of aquatic animals are exposed to increasingly complex mixtures of known and as-yet-unknown chemicals with dioxin-like toxicities in the water cycle. Effect- and cell-based bioanalysis can cover known and yet unknown dioxin and dioxin-like compounds as well as complex mixtures thereof but need to be standardized and integrated into international guidelines for environmental testing. In an international laboratory testing (ILT) following ISO/CD 24295 as standard procedure for rat cell-based DR CALUX un-spiked and spiked extracts of drinking-, surface-, and wastewater were validated to generate precision data for the development of the full ISO-standard. We found acceptable repeatability and reproducibility ranges below 36 % by DR CALUX bioassay for the tested un-spiked and spiked water of different origins. The presence of 17 PCDD/Fs and 12 dioxin-like PCBs was also confirmed by congener-specific GC-HRMS analysis. We compared the sum of dioxin-like activity levels measured by DR CALUX bioassay (expressed in 2,3,7,8-TCDD Bioanalytical Equivalents, BEQ; ISO 23196, 2022) with the obtained GC-HRMS chemical analysis results converted to toxic equivalents (TEQ; van den Berg et al., 2013).

A switch from originator-adalimumab to the biosimilar SB5 in patients with Crohn's disease: an analysis of two propensity score-matched cohorts

BACKGROUND/AIMS

Originator-adalimumab, an established treatment for patients with Crohn's disease (CD), showed no difference in efficacy or adverse events versus adalimumab biosimilar SB5 (SB5-adalimumab) over 10 weeks (W) of treatment. To understand the long-term effectiveness of SB5-adalimumab in CD, patients switched from originator-adalimumab to SB5-adalimumab were compared with patients remaining on originator-adalimumab over 104 W.

METHODS

Data on patients aged ≥18 years, diagnosed with CD and treated at ISCARE, were collected prospectively from July 2018 to January 2021. Primary outcome: clinical disease activity at W52, measured by Harvey-Bradshaw index (HBI). Secondary outcomes: C-reactive protein (CRP), faecal calprotectin (FC) and adalimumab concentrations at W10, 26, 52 and 104, and treatment persistence. To ensure comparable cohorts, patients were propensity score (PS)-matched for age, gender and disease activity.

RESULTS

After matching, 54 patients remained per cohort. At W52, mean (SD) HBI score was 3.2 (2.5) for originator-adalimumab and 4.0 [3.6] for SB5-adalimumab (difference [95% CI] -0.78 [-2.8, 1.3]; n = 18/cohort); no clinically meaningful differences in CRP, FC or drug concentrations were noted. Kaplan-Meier's estimates (95% CI) of remaining on treatment were originator-adalimumab: 0.870 (0.785-0.965) versus SB5-adalimumab: 0.648 (0.533-0.789) at W52 and significantly lower for SB5-adalimumab versus originator-adalimumab (p < .001) over 104 W. Local skin reaction events/pain was the main reason for treatment discontinuation in the SB5-adalimumab cohort (n = 20/54 [37%]).

CONCLUSIONS

These long-term results of CD patients receiving originator-adalimumab or following nonmedical switch to SB5-adalimumab show similar therapeutic effects on clinical disease activity, biological parameters and pharmacokinetic profile in both cohorts from 52 to 104 W. A separation in persistence was observed beyond W26, mainly due to differences in local reactions at the injection site.

Enhanced superconductivity and ferroelectric quantum criticality in plastically deformed strontium titanate

The properties of quantum materials are commonly tuned using experimental variables such as pressure, magnetic field and doping. Here we explore a different approach using irreversible, plastic deformation of single crystals. We show that compressive plastic deformation induces low-dimensional superconductivity well above the superconducting transition temperature (T_c) of undeformed SrTiO₃, with evidence of possible superconducting correlations at temperatures two orders of magnitude above the bulk T_c. The enhanced superconductivity is correlated with the appearance of self-organized dislocation structures, as revealed by diffuse neutron and X-ray scattering. We also observe deformation-induced signatures of quantum-critical ferroelectric fluctuations and inhomogeneous ferroelectric order using Raman scattering. Our results suggest that strain surrounding the self-organized dislocation structures induces local ferroelectricity and quantum-critical dynamics that strongly influence T_c, consistent with a theory of superconductivity enhanced by soft polar fluctuations. Our results demonstrate the potential of plastic deformation and dislocation engineering for the manipulation of electronic properties of quantum materials.

Electrostatic Interactions Control the Functionality of Bacterial Ice Nucleators

Bacterial ice-nucleating proteins (INPs) promote heterogeneous ice nucleation more efficiently than any other material. The details of their working mechanism remain elusive, but their high activity has been shown to involve the formation of functional INP aggregates. Here we reveal the importance of electrostatic interactions for the activity of INPs from the bacterium Pseudomonas syringae by combining a high-throughput ice nucleation assay with surface-specific sum-frequency generation spectroscopy. We determined the charge state of nonviable P. syringae as a function of pH by monitoring the degree of alignment of the interfacial water molecules and the corresponding ice nucleation activity. The net charge correlates with the ice nucleation activity of the INP aggregates, which is minimal at the isoelectric point. In contrast, the activity of INP monomers is less affected by pH changes. We conclude that electrostatic interactions play an essential role in the formation of the highly efficient functionally aligned INP aggregates, providing a mechanism for promoting aggregation under conditions of stress that prompt the bacteria to nucleate ice.

Two Czech patients with familial adenomatous polyposis presenting mosaicism in APC gene

During standard molecular diagnostic procedure, two Czech families with APC (Adenomatous polyposis coli gene) mosaicism have been detected. A woman with attenuated familial adenomatous polyposis (AFAP, OMIM #175100) was recently inspected by next generation sequencing. Standard bioinformatics pipeline, restricted to variants with at least 20% of reads (for germline variants) would miss mutation p.G1412X (NM_000038.5) present in 17% of reads. This novel variant was not present in any of her two children. Another woman with a clinical manifestation of attenuated FAP was tested 16 years ago without conclusive APC mutation found when denaturing gradient gel electrophoresis (DGGE), protein truncation test (PTT), multiplex ligation probe amplification (MLPA) and direct Sanger sequencing were applied. Recent inspection of her son showed clear mutation p.Q1062X (NM_000038.5, NP_000029.2) leading to premature stop codon. This finding led to re-evaluation of this protein position in his mother and detection of mosaicism (11% of allele, 22% of heterozygous cells in blood), which was primarily overlooked. Mutations in both patients were confirmed by allele-specific real time PCR (AS qPCR). In both index patients it was possible to detect and quantify the mosaic allele in biological samples of polyps, adjacent colonic mucosa and buccal swabs. In cases of sporadic appearance of FAP, besides blood we plan to preferably inspect also other samples, where mosaic fraction might be under detection limit of bioinformatics pipelines (<3%). For our future routine NGS sequencing analysis we will apply our in-house somatic variant detection pipeline to minimize the false negative calls when genes with high level of de-novo mutations are analyzed.

Ecophysiological strategies for growth under varying light and organic carbon supply in two species of green microalgae differing in their motility

Mixing events in stratified lakes result in microalgae being exposed to varying conditions in light and organic carbon concentrations. Stratified lakes consist of an upper illuminated strata and a lower, darker strata where organic carbon accumulates. Therefore, in this contribution we explore the importance of dissolved organic carbon for growth under various light intensities by measuring some ecophysiological adaptations in two green microalgae. We compared the non-motile Chlorella vulgaris with the flagellated Chlamydomonas acidophila under auto-, mixo-, and heterotrophic growth conditions. In both algae the maximum photosynthetic and growth rates were highest under mixotrophy, and both algae appeared inhibited in their phosphorus acquisition under heterotrophy. Heterotrophic conditions provoked the largest differences as C. vulgaris produced chlorophyll a in darkness and grew as well as in autotrophic conditions, whereas Chl. acidophila bleached and could not grow heterotrophically. Although the fatty acid composition of both phytoplankton species differed, both species reacted in a similar way to changes in their growth conditions, mainly by a decrease of C18:3n-3 and an increase of C18:1n-9 from auto- to heterotrophic conditions. The two contrasting responses within the group of green microalgae suggest that dissolved organic carbon has a high deterministic potential to explain the survival and behaviour of green algae in the deeper strata of lakes.

Randomised clinical trial: mesalazine versus placebo in the prevention of diverticulitis recurrence

BACKGROUND

Previous studies have reached conflicting conclusions regarding the efficacy of mesalazine in the prevention of recurrent diverticulitis.

AIM

To investigate the efficacy and safety of mesalazine granules in the prevention of recurrence of diverticulitis after acute uncomplicated diverticulitis.

METHODS

Two phase 3, randomised, placebo-controlled, double-blind multicentre trials (SAG-37 and SAG-51) investigated mesalazine granules in patients with prior episodes (<6 months) of uncomplicated left-sided diverticulitis. Patients were randomised to receive either 3 g mesalazine once daily or placebo (SAG-37, n=345) or to receive either 1.5 g mesalazine once daily, 3 g once daily or placebo for 96 weeks (SAG-51, n=330). The primary endpoint was the proportion of recurrence-free patients during 48 weeks (SAG-37 and SAG-51) or 96 weeks (SAG-51) of treatment.

RESULTS

Mesalazine did not increase the proportion of recurrence-free patients over 48 or 96 weeks compared to placebo. In SAG-37, the proportion of recurrence-free patients during 48 weeks was 67.9% with mesalazine and 74.4% with placebo (P=.226). In SAG-51, the proportion of recurrence-free patients over 48 weeks was 46.0% with 1.5 g mesalazine, 52.0% with 3 g mesalazine and 58.0% with placebo (P=.860 for 3 g mesalazine vs placebo) and over 96 weeks 6.9%, 9.8% and 23.1% respectively (P=.980 for 3 g mesalazine vs placebo). Patients with only one diverticulitis episode in the year prior to study entry had a lower recurrence risk compared to >1 episode. Safety data revealed no new adverse events.

CONCLUSION

Mesalazine was not superior to placebo in preventing recurrence of diverticulitis.

Infliximab Biosimilar (Remsima™) in Therapy of Inflammatory Bowel Diseases Patients: Experience from One Tertiary Inflammatory Bowel Diseases Centre

BACKGROUND

The evidence on the efficacy and safety of biosimilar infliximab (IFX) in patients with inflammatory bowel diseases (IBD) is sparse.

METHODS

Consecutive IBD patients visiting our centre were included. One cohort composed of prospectively followed patients who were switched from original to biosimilar IFX between January and March 2015. The second cohort included retrospectively assessed anti-tumor necrosis factor α-naïve patients who started therapy between January 2015 and January 2016. Disease activity was assessed using standard clinical indices, endoscopic evaluation, and laboratory parameters (blood count, C-reactive protein (CRP) and fecal calprotectin (FC)). Trough levels and anti-drug antibodies (ATIs) were also measured. Patients were evaluated 56 weeks (W56) after switch and at week 14 (W14) and week 46 (W46) in the naïve cohort.

RESULTS

Seventy-four IBD patients were switched to biosimilar IFX and 119 naïve patients newly initiated therapy with the preparation. Disease activity remained stable in a majority of switched patients (remission at week 0 (W0) vs. W56: 72.2 vs. 77.8%; median difference of both Harvey-Bradshaw index and Simple Clinical Colitis Activity Index between W0 and W56 was 0). When W0 and W56 were compared, no significant difference in CRP (4.3 ± 8.0 vs. 3.3 ± 3.8 mg/l; p = 0.89) and FC (135 ± 153 vs. 199 ± 225 µg/g; p = 0.17) was observed. In total, 92% of Crohn's disease (CD) and 83% of ulcerative colitis (UC) patients responded to induction therapy (W14) with biosimilar IFX. At W46, the response rate was 86% in CD and 64% in UC. Moreover, half of UC patients experienced mucosal healing at W14 and improvement of perianal disease occurred in 95% of CD at W46. In this cohort, clear steroid-sparing effect was observed. No increase in immunogenicity was found in switched patients (ATI positivity: 9.5 vs. 6.0%, p = 0.54) and the type and frequency of adverse events were comparable to the original preparation in both cohorts.

CONCLUSION

Switching of IBD patients from original to biosimilar IFX is effective and safe.

Evaluation of PET quantification accuracy in vivo. Comparison of measured FDG concentration in the bladder with urine samples

Quantitative positron emission tomography (PET) requires accurate scanner calibration, which is commonly performed using phantoms. It is not clear to what extent this procedure ensures quantitatively correct results in vivo, since certain conditions differ between phantom and patient scans.

AIM

We, therefore, have evaluated the actual quantification accuracy in vivo of PET under clinical routine conditions.

PATIENTS, METHODS

We determined the activity concentration in the bladder in patients undergoing routine [18F]FDG whole body investigations with three different PET scanners (Siemens ECAT EXACT HR+ PET: n = 21; Siemens Biograph 16 PET/CT: n = 16; Philips Gemini-TF PET/CT: n = 19). Urine samples were collected immediately after scan. Activity concentration in the samples was determined in well counters cross-calibrated against the respective scanner. The PET (bladder) to well counter (urine sample) activity concentration ratio was determined.

RESULTS

Activity concentration in the bladder (PET) was systematically lower than in the urine samples (well counter). The patient-averaged PET to well counter ratios for the investigated scanners are (mean ± SEM): 0.881 ± 0.015 (ECAT HR+), 0.898 ± 0.024 (Biograph 16), 0.932 ± 0.024 (Gemini-TF). These values correspond to underestimates by PET of 11.9%, 10.2%, and 6.8%, respectively.

CONCLUSIONS

The investigated PET systems consistently underestimate activity concentration in the bladder. The comparison of urine samples with PET scans of the bladder is a straightforward means for in vivo evaluation of the expectable quantification accuracy. The method might be interesting for multi-center trials, for additional quality assurance in PET and for investigation of PET/MR systems for which clear proof of sufficient quantitative accuracy in vivo is still missing.

The management of iron deficiency in inflammatory bowel disease--an online tool developed by the RAND/UCLA appropriateness method

BACKGROUND

Iron deficiency is a common and undertreated problem in inflammatory bowel disease (IBD).

AIM

To develop an online tool to support treatment choice at the patient-specific level.

METHODS

Using the RAND/UCLA Appropriateness Method (RUAM), a European expert panel assessed the appropriateness of treatment regimens for a variety of clinical scenarios in patients with non-anaemic iron deficiency (NAID) and iron deficiency anaemia (IDA). Treatment options included adjustment of IBD medication only, oral iron supplementation, high-/low-dose intravenous (IV) regimens, IV iron plus erythropoietin-stimulating agent (ESA), and blood transfusion. The panel process consisted of two individual rating rounds (1148 treatment indications; 9-point scale) and three plenary discussion meetings.

RESULTS

The panel reached agreement on 71% of treatment indications. 'No treatment' was never considered appropriate, and repeat treatment after previous failure was generally discouraged. For 98% of scenarios, at least one treatment was appropriate. Adjustment of IBD medication was deemed appropriate in all patients with active disease. Use of oral iron was mainly considered an option in NAID and mildly anaemic patients without disease activity. IV regimens were often judged appropriate, with high-dose IV iron being the preferred option in 77% of IDA scenarios. Blood transfusion and IV+ESA were indicated in exceptional cases only.

CONCLUSIONS

The RUAM revealed high agreement amongst experts on the management of iron deficiency in patients with IBD. High-dose IV iron was more often considered appropriate than other options. To facilitate dissemination of the recommendations, panel outcomes were embedded in an online tool, accessible via http://ferroscope.com/.

Daphnia's dilemma of adjusting carbon budgets when facing limitations by food quantity and the essential organic compound cholesterol

We studied the carbon metabolism in Daphnia when the amount of carbon (food quantity) and/or the content of biochemical nutrients (food quality) are limiting. Growth performances and carbon (C) budgets of Daphnia magna (assimilation, faeces egestion, excretion and respiration measured by [14C]-tracing) were analysed when animals were raised on different food quantities and concentrations of cholesterol, an essential biochemical food compound. Cholesterol is of special interest because it not only acts as limiting nutrient but also contributes to the overall carbon pool of the animals. As the tissue cholesterol concentration in Daphnia is quite low, we hypothesized the selective exclusion of cholesterol from carbon budgeting and tested this by using radiolabelled cholesterol. Somatic growth rates of D. magna were highest at high quantity and quality and were reduced to a moderate value if either the food quantity or the cholesterol concentration was low. Growth was lowest at low food quantity and quality. The measurements of C budgets revealed high regulative response to low food quality at high food quantity only. Here, low dietary cholesterol caused that bulk carbon assimilation efficiency (AE) decreased and that assimilated (excess) carbon was increasingly respired. Additionally, Daphnia enhanced efficient adjustment of C budgets when facing cholesterol limitation by (i) increasing the AE of the cholesterol itself and (ii) not changing cholesterol respiration which was still not detectable. In contrast, at low food quantity Daphnia has the dilemma to be unable to adjust for low food quality emphasizing that food quantity limitation could overrule food quality effects.

Infliximab dependency in children with Crohn's disease

BACKGROUND

Recently, infliximab dependency has been described.

AIM

To assess frequency of ID in 82 consecutive Crohn's disease children treated with infliximab 2000-2006 and to describe clinical and genetic predictors of long-term infliximab response.

METHODS

A phenotype model of infliximab dependency was used to assess treatment response: 'immediate outcome' (30 days after infliximab start)--complete/partial/no response. 'Long-term outcome': (i) prolonged response: maintenance of complete/partial response; (ii) infliximab dependency: relapse < or = 90 days after intended infliximab cessation requiring repeated infusions to regain complete/partial response or need of infliximab >12 months to sustain response. Polymorphisms TNF-308 A>G, TNF-857 C>T, Casp9 93 C>T, FasL-844 C>T, LTA 252 C>T and CARD15 (R702W, G908R, 1007fs) were analysed.

RESULTS

Ninety-four per cent of children obtained complete/partial response. In long-term outcome, 22% maintained prolonged response, 12% had no response, while 66% became infliximab dependent. Perianal disease and no previous surgery were associated with infliximab dependency (OR 5.34, 95% CI: 1.24-22.55; OR 6.7, 95% CI: 1.67-26.61). No association was found with studied polymorphisms. The cumulative probability of surgery 50 months after starting infliximab was 10% in infliximab dependency, 30% in prolonged responders and 70% in nonresponders (P = 0.0002).

CONCLUSIONS

Sixty-six per cent of children became infliximab dependent. Perianal disease and no surgery prior to infliximab were associated with infliximab dependency phenotype.

Variants of CARD15, TNFA and PTPN22 and susceptibility to Crohn's disease in the Czech population: high frequency of the CARD15 1007fs

Crohn's disease (CD) has been shown to be associated with the variants in the CARD15 gene as well as in other genes involved in the immune response. The frequencies of the variants profoundly differ among populations and so does the associated risk. We examined the associations of variants in the CARD15, TNFA and PTPN22 genes with pediatric-onset and adult-onset CD in the Czech population. Genotype, phenotype and allelic frequencies were compared between 345 patients with CD (136 pediatric-onset and 209 adult-onset patients) and 501 unrelated healthy controls. At least one minor allele of the CARD15 gene was carried by 46% patients and only 21% control subjects (OR = 3.2, 95% CI 2.4-4.4). In a multiple logistic regression model, the strongest association with CD was found for the 1007fs variant (OR = 4.6, 95% CI 3.0-7.0), followed by p.G908R (OR = 2.9, 95% CI 1.5-5.7) and p.R702W (OR = 1.7, 95% CI 1.0-2.9), while no independent association was found for the remaining variants in the CARD15 gene (p.268S, p.955I and p.289S), for the p.R620W variant in the PTPN22 gene or for the g.-308G>A variant in the TNFA gene. The age at CD onset was strongly modified by positivity for the 1007fs allele: it was present in 42% pediatric-onset and only 25% adult-onset patients. In conclusion, we report a high frequency of the minor allele of the CARD15 1007fs polymorphism in the Czech population and a strong effect of this allele on the age at disease onset.

Adalimumab for maintenance treatment of Crohn's disease: results of the CLASSIC II trial

BACKGROUND

Adalimumab induced clinical remission after four weeks in patients with active Crohn's disease in the CLASSIC I trial.

OBJECTIVE

To evaluate long term efficacy and safety of adalimumab maintenance therapy in Crohn's disease in a follow-on randomised controlled trial (CLASSIC II).

METHODS

In the preceding CLASSIC I trial, 299 patients with moderate to severe Crohn's disease naive to tumour necrosis factor antagonists received induction therapy with adalimumab 40 mg/20 mg, 80 mg/40 mg, or 160 mg/80 mg, or placebo, at weeks 0 and 2. In all, 276 patients from CLASSIC I enrolled in CLASSIC II and received open-label adalimumab 40 mg at weeks 0 (week 4 of CLASSIC I) and 2; 55 patients in remission at both weeks 0 and 4 were re-randomised to adalimumab 40 mg every other week, 40 mg weekly, or placebo for 56 weeks. Patients not in remission at both weeks 0 and 4 were enrolled in an open-label arm and received adalimumab 40 mg every other week. With non-response or flare, these patients could have their dosages increased to 40 mg weekly. Patients in the randomised arm with continued non-response or disease flare could switch to open-label adalimumab 40 mg every other week and again to 40 mg weekly. The primary end point was maintenance of remission (CDAI <150) in randomised patients through week 56.

RESULTS

Of 55 patients randomised at week 4, 79% who received adalimumab 40 mg every other week and 83% who received 40 mg weekly were in remission at week 56, v 44% for placebo (p<0.05). In all, 204 patients entered the open-label arm. Of these, 93 (46%) were in clinical remission at week 56. Adalimumab was generally well-tolerated in all patients.

CONCLUSIONS

Adalimumab induced and maintained clinical remission for up to 56 weeks in patients with moderate to severe Crohn's disease naive to anti-TNF treatment.

6-Thioguanine treatment in inflammatory bowel disease: a critical appraisal by a European 6-TG working party

Recently, the suggestion to use 6-thioguanine (6-TG) as an alternative thiopurine in patients with inflammatory bowel disease (IBD) has been discarded due to reports about possible (hepato) toxicity. During meetings arranged in Vienna and Prague in 2004, European experts applying 6-TG further on in IBD patients presented data on safety and efficacy of 6-TG. After thorough evaluation of its risk-benefit ratio, the group consented that 6-TG may still be considered as a rescue drug in stringently defined indications in IBD, albeit restricted to a clinical research setting. As a potential indication for administering 6-TG, we delineated the requirement for maintenance therapy as well as intolerance and/or resistance to aminosalicylates, azathioprine, 6-mercaptopurine, methotrexate and infliximab. Furthermore, indications are preferred in which surgery is thought to be inappropriate. The standard 6-TG dosage should not exceed 25 mg daily. Routine laboratory controls are mandatory in short intervals. Liver biopsies should be performed after 6-12 months, three years and then three-yearly accompanied by gastroduodenoscopy, to monitor for potential hepatotoxicity, including nodular regenerative hyperplasia (NRH) and veno-occlusive disease (VOD). Treatment with 6-TG must be discontinued in case of overt or histologically proven hepatotoxicity.

European evidence based consensus on the diagnosis and management of Crohn's disease: special situations

This third section of the European Crohn's and Colitis Organisation (ECCO) Consensus on the management of Crohn's disease concerns postoperative recurrence, fistulating disease, paediatrics, pregnancy, psychosomatics, extraintestinal manifestations, and alternative therapy. The first section on definitions and diagnosis reports on the aims and methods of the consensus, as well as sections on diagnosis, pathology, and classification of Crohn's disease. The second section on current management addresses treatment of active disease, maintenance of medically induced remission, and surgery of Crohn's disease.

Relationship between fecal crude protein concentration and diet organic matter digestibility in cattle1

The positive relationship between fecal CP concentration and diet OM digestibility in cattle, which is based on increasing undigested microbial CP and decreasing fecal OM as OM digestibility increases, may be used as an indirect method for estimating diet OM digestibility from fecal CP concentration. Results of digestibility trials (445 individual observations) conducted at Hohenheim and Braunschweig, Germany, and at Gumpenstein, Austria, were used to study the relationship between CP concentration in feces (x, g/kg OM) and OM digestibility (y, %). The best fit was obtained with the curvilinear relationship y = ai -107.7e(-0.01515 x x), with a1 = 79.76 and a2 = 72.86 (R2 = 0.82; residual SD = 2.7; SE = 0.13), which takes into account the effects of location (i = 1 for Braunschweig and Hohenheim, and i = 2 for Gumpenstein). Dietary CP and crude fat concentration, and DMI had no effect on fecal CP content, whereas crude fiber content, proportion of concentrate in the diet, and forage type significantly affected CP concentration in feces; however, the magnitude of these effects was less than 2 percentage units, and the direction of the effect of proportion of concentrate in the diet was not uniform. The curvilinear relationship between fecal CP concentration (observed range, 100 to 300 g/kg of OM) and diet OM digestibility (observed range = 57 to 80%) may be used to estimate diet OM digestibility, particularly for field trials, as it requires no feed samples and does not physically restrict the animal.

A double-blind dose-escalating trial comparing novel mesalazine pellets with mesalazine tablets in active ulcerative colitis

BACKGROUND

Mesalazine as the treatment standard for ulcerative colitis can be applied in different galenical preparations.

AIM

A novel formulation of mesalazine pellets with delayed and prolonged release characteristics was compared with conventional Eudragit L-coated tablets. Furthermore, the effect of mesalazine dose escalation on nonresponders was evaluated in both treatment groups.

METHODS

A total of 233 patients with mild to moderately active ulcerative colitis were randomized to receive either mesalazine (1.5 g/day in three doses) as pellets (n = 115) or tablets (n = 118) for 8 weeks. At insufficient response, the dose was increased to 3.0 g.

RESULTS

The clinical remission rate (clinical activity index < or = 4) for pellets was 67% vs. 68% for tablets which statistically proved to be not inferior (significance level alpha = 2.5%). In patients without dose increase, the remission rate was 47% (pellets) vs. 42% (tablets). Endoscopic improvement was observed in 80% (pellets) vs. 83% (tablets), and histological improvement in 48% (pellets) vs. 52% (tablets) of patients.

CONCLUSIONS

Mesalazine pellets are as effective as tablets in the treatment of mild to moderately active ulcerative colitis. Dose escalation to 3.0 g/day is a valid option for nonresponders to a starting dose of 1.5 g/day.

Migration of langerhans cells and dermal dendritic cells in skin organ cultures: augmentation by TNF-alpha and IL-1beta

Migration from sites of antigen encounter to lymphoid organs is essential to the strong immunogenic function of dendritic cells (DC). In the skin, migration proceeds through dermal lymphatic vessels and is regulated in an incompletely understood way by inflammatory mediators. We studied the effects of tumor necrosis factor alpha (TNF-alpha) and interleukin-1beta (IL-1beta) in mouse skin organ cultures by direct enumeration of migrating DC and by immunohistochemistry. (1) Neutralizing antibodies to TNF-alpha and IL-1beta inhibited migration of DC, also in human skin explants (TNF-alpha). (2) TNF-alpha at low concentrations (50 U/mL) and IL-1beta (50-3000 U/mL) augmented migration to about 150% of spontaneous migration. (3) High concentrations of TNF-alpha (5000 U/mL) inhibited migration by approximately 50%. (4) DC migration from skin explants of TNF-alpha/lymphotoxin-alpha double-deficient mice and TNF-receptor type 1 and 2 double knockout mice was not impaired. (5) TNF-alpha effects were neutralized by anti-IL-1beta, and vice versa. We conclude that in normal animals both TNF-alpha and IL-1beta are required for DC migration to occur. In the complete absence of one cytokine (TNF-alpha), however, backup mechanisms step in.

Human cutaneous dendritic cells migrate through dermal lymphatic vessels in a skin organ culture model

The capacity to migrate from peripheral tissues, where antigen is encountered, to lymphoid organs, where the primary immune response is initiated, is crucial to the immunogenic function of dendritic cells (DC). The skin is a suitable tissue to study migration. DC were observed to gather in distinct nonrandom arrays ("cords") in the dermis upon culture of murine whole skin explants. It is assumed that cords represent lymphatic vessels. Using a similar organ culture model with human split-thickness skin explants, we investigated migration pathways in human skin. We made the following observations. 1) Spontaneous emigration of Langerhans cells took place in skin cultured for 1-3 d. Nonrandom distribution patterns of strongly major histocompatibility complex class II-expressing DC (cords) occurred in cultured dermis. A variable, yet high (>50%) percentage of these DC coexpressed the Birbeck granule-associated antigen "Lag." Ultrastructurally, the cells corresponded to mature DC. 2) Electron microscopy proved that the dermal structures harboring the accumulations of DC (i.e., cords) were typical lymph vessels. Moreover, markers for blood endothelia (monoclonal antibody PAL-E, Factor VIII-related antigen) and markers for cords (strong major histocompatibility complex class II expression on nonrandomly arranged, hairy-appearing cells) were expressed in a mutually exclusive pattern. 3) On epidermal sheets we failed to detect gross changes in the levels of expression of adhesion molecules (CD44, CD54/ ICAM-1, E-cadherin) on keratinocytes in the course of the culture period. The reactivity of a part of the DC in the dermal cords with Birbeck granule-specific monoclonal antibody "Lag" suggests that the migratory population is composed of both epidermal Langerhans cells and dermal DC. We conclude that this organ culture model may prove helpful in resolving pathways and mechanisms of DC migration.

[Comprehension of metaphoric speech by healthy probands and schizophrenic patients. An experimental psychopathologic contribution to concretism]

The comprehension of auditorily presented sentences with a metaphoric content was investigated in three experimental studies. Experiments 1 and 2 established the time course in control subjects: At 400 ms after prime offset only the concrete meaning was activated, whereas 1200 ms after prime offset both concrete and metaphoric meaning were active. Experiment 3 demonstrated a heightened activation of the concrete meaning and no activation of the metaphoric meaning in schizophrenic patients. These results resolve the dispute over the use of concepts by schizophrenic patients (overinclusive versus underinclusive), and can be related to the neurobiology of working memory and of associative semantic memory. The three experiments may serve as paradigms of how the method of mental chronometry can be applied in the field of psychopathology.

Correlations between verbal memory performance and electrocorticographically determined suppression of electrical brain activity in intracarotid amobarbital tests

As a part of presurgical evaluation, bilateral intracarotid amobarbital procedures (IAPs) were performed in 42 patients (84 tests) with long-standing, medically intractable complex-partial seizures. During the IAPs, electrocorticographic (ECoG) recording was carried out via bilaterally implanted subdural electrodes. Five distinct patterns of suppression of electrical brain activity were observed: (1) an isoelectric line; (2) a burst-suppression pattern; (3) polyphasic waves; (4) high-voltage beta; and (5) low-voltage beta activity. Further, two types of specific reactions of the epileptic focus were detectable: (1) spike-burst-suppression patterns (SBS; 11 left; 7 right; 6 in both IAPs) and amobarbital-induced spikes (7 left; 4 right). ECoG suppression patterns as well as SBS and spike induction showed great variability in duration and overall occurrence. To determine the influence of these amobarbital-induced ECoG changes on results of IAP memory testing, performance in a verbal learning task was analyzed according to the ECoG patterns predominant during encoding. In left IAPs, it was found that SBS at the beginning of or during encoding had a significant negative effect on verbal memory. In right IAPs, verbal memory performance improved significantly with the decline of ECoG suppression. Hence, verbal memory performance in IAPs is significantly affected by specific ECoG suppression patterns and activation of the epileptic focus.