[A toddler with a lump on his penis]

A father consulted his general practitioner with his 3-years-old son who had swelling on his penis for several months. He experienced no miction problems. The swelling appeared to be a retention of smegma. This is harmless and will disappear spontaneously as the process of separation of the preputium continues.

Ready for regulatory use: NAMs and NGRA for chemical safety assurance

New approach methodologies (NAMs) that do not use experimental animals are, in certain settings, entirely appropriate for assuring the safety of chemical ingredients, although regulatory adoption has been slow. In this opinion article we discuss how scientific advances that utilize NAMs to certify systemic safety are available now and merit broader acceptance within the framework of next generation risk assessments (NGRA).

POS0411 COMPARISON OF MTX-POLYGLUTAMATE ACCUMULATION PROFILES IN PERIPHERAL BLOOD MONONUCLEAR CELLS AND ERYTHROCYTES DURING 6 MONTHS MTX-THERAPY IN THE METHOTREXATE MONITORING (MeMo) TRIAL

Background

Optimal dosing of methotrexate (MTX) in rheumatoid arthritis (RA) remains challenging. To this end, monitoring of intracellular MTX polyglutamates (MTX-PGs) in red blood cells (RBCs) has been investigated as a potential marker of MTX (non-)response, with contradictory results. As enucleated, non-proliferative cells, mature RBCs lack regulated folate metabolism and are devoid of folylpolyglutamate synthetase (FPGS) activity catalyzing the conversion of MTX to MTX-PGs. Therefore, it has been argued that analysis of MTX-PG in immune-effector cells, represented by peripheral blood mononuclear cells (PBMCs), would be more relevant. However, no prospective study has been performed measuring MTX-PG levels in PBMCs nor in comparison with RBCs.

Objectives

To investigate the pharmacokinetics of MTX-PG accumulation in RBCs and PBMCs in newly diagnosed RA patients in the early phase of MTX treatment.

Methods

In a clinical prospective cohort study (Methotrexate Monitoring (NTR7149)), RA patients were administered MTX op to 25 mg/week, as described before. (1) At 1, 2, 3 and 6 months after start of therapy, blood was collected and RBCs were isolated by centrifugation and PBMCs after Ficoll density gradient centrifugation. MTX-PG1-6 concentrations in these cells were analyzed using a UPLC-MS/MS method with including custom-made stable isotopes of MTX-PG1-6 as internal standards. (2) UPLC-MS/MS measurements for MTX-PG1-6 were performed with a Waters Acquity BEH C18 column coupled to an AB Sciex 6500+ with the ESI operating on the positive mode. MTX dosing and concomitant treatments were in conformity with clinical practice. (3)

Results

46 consecutive patients were included in this study; 76% female, mean age: 57.8 years, mean baseline DAS28-ESR: 3.5, as described before. (1) Mean dosage was 10.5 mg (SD: 1.5) at baseline, 16.3 mg (2.5) at month 1, 22.7 mg (4.5) at month 2, 19.5 mg (6.3) at month 3 and 19.1 mg (6.2) at month 6.

MTX-PG accumulation in PBMCs and RBCs revealed a disparate profile in both MTX-PG distribution and absolute accumulation levels (Figure 1A/B). Remarkably, MTX-PG distribution in PBMCs was mainly composed of MTX-PG1 (58%), and to a lesser extent MTX-PG2 (27%) and MTX-PG3 (15%). Longer chain MTX-PG4-6 were also detectable in PBMCs, but at lower levels (mean: 4.0 – 6.7 fmol/10^6 cells) than MTX-PG1-3. Moreover, this MTX-PG distribution profile in PBMCs remained constant over a MTX therapy period of 6 months (Figure 1A). The RBC MTX-PG accumulation profile shows mainly MTX-PG1 and lower levels of MTX-PG2-6 at 1 month after the start of therapy. After 3 months of therapy, MTX-PG3 is the main PG-moiety with also MTX-PG4,5,6 being detected. This profile is largely similar after 6 months of therapy. With respect to total intracellular MTX-PG1-6 accumulation, PBMCs had significantly (p<0.001) 10-20-fold higher levels than RBCs at all analyzed time points (Figure 1A/B). Total MTX-PG1-6 levels in RBCs and PBMCs at all time points were weakly correlated (r=0.41, p<0.01) (Figure 1C).

Figure 1.

Individual MTX-PG concentrations in PBMCs (A) and RBCs (B) during the first 6 months of MTX administration (note the different scaling of the y-axes). At 6 months, 36 patients were still on MTX treatment. Panel (C): Spearman’s correlation plot of total MTX-PGs in RBCs versus PBMCs of all time points.

The disparate MTX-PG accumulation and distribution profiles in PBMCs versus RBCs of RA patients may be associated with the shorter life span of PBMCs and the low FPGS activity in RBCs. (4)

No significant relation between MTX-PGs and DAS28 was found (data not shown).

Conclusion

This study shows that in newly diagnosed RA patients starting MTX therapy, MTX-PG concentrations in PBMCs are significantly 10-20-fold higher than in RBCs over a period of 6 months, with a disparate MTX-PG distribution profile in PBMCs (highest: MTX-PG1) than RBCs (highest: MTX-PG3).

References

[1]RCF Hebing, Arthr Rheum (2021)

[2]E den Boer, Anal Bioanal Chem (2013)

[3]J Smolen, Ann Rheum Dis (2020)

[4]IB Muller, Ther Drug Monit (2019)

Acknowledgements

Acknowledgements: We would like to thank all participating patients and Pfizer (grant 53233663 / WI230458), AmsterdamUMC (AI&II extension grant) and NVKC (Noyons grant 2018)

Disclosure of Interests

Renske Hebing Grant/research support from: Pfizer (grant 53233663 / WI230458), NVKC (Netherlands Society for Clinical Chemistry, Noyons grant 2018) and AmsterdamUMC (extension grant), Marry Lin: None declared, Eduard Struys: None declared, Sohaila Mahmoud: None declared, Ittai Muller: None declared, Sandra Heil: None declared, Pieter Griffioen: None declared, WIllem Lems: None declared, Bart van den Bemt Speakers bureau: Pfizer, UCB, Sanofi-Aventis, Galapagos, Amgen and Eli Lilly, Michael Nurmohamed Grant/research support from: Pfizer grant 53233663 / WI230458, Gerrit Jansen: None declared, Robert De Jonge Grant/research support from: NVKC (Netherlands Society for Clinical Chemistry, Noyons grant)

AB0061 PHARMACOKINETICS OF METHOTREXATE POLYGLUTAMATES IN PERIPHERAL BLOOD MONONUCLEAR CELLS OF RA PATIENTS IS SIMILAR AFTER SUBCUTANEOUS OR ORAL ADMINISTRATION IN THE METHOTREXATE MONITORING (MeMo) TRIAL

Background

Pharmacokinetics of methotrexate (MTX) after oral and subcutaneous administration to RA patients differs: MTX levels in plasma and MTX-polyglutamate (MTX-PG) accumulation in erythrocytes are higher during equidosed subcutaneous compared to oral MTX treatment. (1,2) No data are available whether administration route of MTX differentially impacts the intracellular concentrations of MTX-PGs in peripheral blood mononuclear cells (PBMCs) during MTX therapy.

Objectives

To investigate the pharmacokinetics of MTX-PGs in PBMCs of newly diagnosed RA patients receiving oral or subcutaneous MTX in the early phase (1, 2, 3 and 6 months) of MTX treatment.

Methods

In a clinical prospective cohort study (MeMo study (NTR7149)), RA patients were

administered oral (n=24) or subcutaneous (n=22) MTX up to 25 mg MTX/week, as described before. (1) At 1, 2, 3 and 6 months after the start of therapy, PBMCs were isolated via Ficoll density gradient centrifugation. Individual MTX-PG forms (MTX-PG1-6) in PBMCs were analyzed by a UPLC-MS/MS method including custom-made stable isotopes of MTX-PG1-6 as internal standards (3). UPLC-MS/MS measurements of the PBMCs were performed with a Waters Acquity BEH C18 column coupled to an AB Sciex 6500+ with the ESI operating on the positive mode. Dosing, concomitant treatments and DAS28-ESR assessments were in conformity with clinical practice. (4)

Results

46 consecutive patients were included in this study; 76% female, mean age: 57.8 years, BMI: 25.8, smokers: 20%, mean baseline DAS28-ESR: 3.5, as described before. (1) MTX dose at baseline was 10.5 mg (SD: 1.5) for both groups, 15.4 mg (4.4) and 16.8 mg (1.8) at 1 month, 22.8 mg (3.9) and 22.4 mg (5.2) at 2 months, 20.1 mg (6.3) and 20.8 mg (5.6) at 3 months, and 19.7 mg (6.1) and 18.5 mg (6.7) at 6 months for oral and subcutaneous use, respectively. MTX-PG analyses in PBMCs for individual and total MTX-PGs revealed no significant differences between oral and subcutaneous administration groups at 1, 2, 3, and 6 months (Figure 1). Linear regression of LN transformed MTX-PG levels in PBMCs and administration route, corrected for age, baseline DAS28, smoking, BMI, eGFR and MTX dose, showed a trend towards higher MTX-PG levels in PBMCs after subcutaneous MTX administration compared to oral administration (data not shown). MTX-PG distribution in PBMCs was mainly composed of MTX-PG1 (58%), and to a lesser extent MTX-PG2 (27%) and MTX-PG3 (15%). Longer chain MTX-PGs beyond MTX-PG4 were detectable in PBMCs, but at levels lower than MTX-PG1-3 (mean: 4.0 – 6.7 fmol/106 cells). Total MTX-PG accumulation in PBMCs was approximately 10-20 fold higher than in erythrocytes. PBMC accumulation was rather stable, whereas RBC MTX-PG accumulation increased between 1 to 3 months to reach a plateau (Figure 1).

Figure 1.

Loess regression of MTX-PG concentrations in PBMCs (MTX-PG1-3) and RBCs (MTX-PG1-6) of RA patients during the first 6 months of oral or subcutaneous MTX administration. At 6 months, 18 patients using oral and 18 patients using subcutaneous MTX were still continuing MTX treatment. Means (lines) and SE (grey areas) are depicted.

Conclusion

This study demonstrated that MTX-PG accumulation in PBMCs early on in the MTX treatment of RA patients was not significantly different between oral or subcutaneous MTX administration routes.

References

[1]RCF Hebing et al, Arthritis Rheum (2021); 60:339-348

[2]M Hoekstra et al, J Rheumatol (2004); 31:645-8

[3]E Den Boer et al, Anal Bioanal Chem (2013); 405: 1673-1681

[4]J Smolen et al, Ann Rheum Dis (2020); 79:685-699

Acknowledgements

We would like to thank all participating patients and Pfizer (grant 53233663 / WI230458), NVKC (Noyons grant) and AmsterdamUMC (AI&II extension grant).

Disclosure of Interests

Renske Hebing Grant/research support from: Pfizer, grant number 53233663 / WI230458, Amsterdam UMC (AI&II extension grant), NVKC (Netherlands Society for Clinical Chemistry, Noyons grant), Marry Lin: None declared, Eduard Struys: None declared, Sohaila Mahmoud: None declared, Ittai Muller: None declared, WIllem Lems: None declared, Bart van den Bemt Speakers bureau: Pfizer, UCB, Sanofi-Aventis, Galapagos, Amgen and Eli Lilly, Gerrit Jansen: None declared, Robert De Jonge Grant/research support from: NVKC (Netherlands Society for Clinical Chemistry, Noyons grant), Michael Nurmohamed Grant/research support from: Pfizer grant

Latent Variables Capture Pathway-Level Points of Departure in High-Throughput Toxicogenomic Data

Estimation of points of departure (PoDs) from high-throughput transcriptomic data (HTTr) represents a key step in the development of next-generation risk assessment (NGRA). Current approaches mainly rely on single key gene targets, which are constrained by the information currently available in the knowledge base and make interpretation challenging as scientists need to interpret PoDs for thousands of genes or hundreds of pathways. In this work, we aimed to address these issues by developing a computational workflow to investigate the pathway concentration–response relationships in a way that is not fully constrained by known biology and also facilitates interpretation. We employed the Pathway-Level Information ExtractoR (PLIER) to identify latent variables (LVs) describing biological activity and then investigated in vitro LVs’ concentration–response relationships using the ToxCast pipeline. We applied this methodology to a published transcriptomic concentration–response data set for 44 chemicals in MCF-7 cells and showed that our workflow can capture known biological activity and discriminate between estrogenic and antiestrogenic compounds as well as activity not aligning with the existing knowledge base, which may be relevant in a risk assessment scenario. Moreover, we were able to identify the known estrogen activity in compounds that are not well-established ER agonists/antagonists supporting the use of the workflow in read-across. Next, we transferred its application to chemical compounds tested in HepG2, HepaRG, and MCF-7 cells and showed that PoD estimates are in strong agreement with those estimated using a recently developed Bayesian approach (cor = 0.89) and in weak agreement with those estimated using a well-established approach such as BMDExpress2 (cor = 0.57). These results demonstrate the effectiveness of using PLIER in a concentration–response scenario to investigate pathway activity in a way that is not fully constrained by the knowledge base and to ease the biological interpretation and support the development of an NGRA framework with the ability to improve current risk assessment strategies for chemicals using new approach methodologies.

Beyond AOPs: A Mechanistic Evaluation of NAMs in DART Testing

New Approach Methodologies (NAMs) promise to offer a unique opportunity to enable human-relevant safety decisions to be made without the need for animal testing in the context of exposure-driven Next Generation Risk Assessment (NGRA). Protecting human health against the potential effects a chemical may have on embryo-foetal development and/or aspects of reproductive biology using NGRA is particularly challenging. These are not single endpoint or health effects and risk assessments have traditionally relied on data from Developmental and Reproductive Toxicity (DART) tests in animals. There are numerous Adverse Outcome Pathways (AOPs) that can lead to DART, which means defining and developing strict testing strategies for every AOP, to predict apical outcomes, is neither a tenable goal nor a necessity to ensure NAM-based safety assessments are fit-for-purpose. Instead, a pragmatic approach is needed that uses the available knowledge and data to ensure NAM-based exposure-led safety assessments are sufficiently protective. To this end, the mechanistic and biological coverage of existing NAMs for DART were assessed and gaps to be addressed were identified, allowing the development of an approach that relies on generating data relevant to the overall mechanisms involved in human reproduction and embryo-foetal development. Using the knowledge of cellular processes and signalling pathways underlying the key stages in reproduction and development, we have developed a broad outline of endpoints informative of DART. When the existing NAMs were compared against this outline to determine whether they provide comprehensive coverage when integrated in a framework, we found them to generally cover the reproductive and developmental processes underlying the traditionally evaluated apical endpoint studies. The application of this safety assessment framework is illustrated using an exposure-led case study.

[A toddler with loose nails]

A father consulted his general practitioner with his 18-month-old son with several loose fingernails. We saw a toddler with nine fingernails that peeled off on the proximal side. The normal nails were visible under the loose nails. Diagnosis: onychomadesis.

How has the COVID-19 pandemic affected eczema self-management and help seeking? A qualitative interview study with young people and parents/carers of children with eczema

Background

Eczema can have a considerable impact on quality of life. Treatments can improve this, but management is complex. Barriers to eczema self‐management may be impacted upon by environmental context, such as the COVID‐19 pandemic.

Objectives

To explore experiences of eczema, self‐management, and accessing healthcare and advice during the COVID‐19 pandemic among young people with eczema and parents/carers of children with eczema.

Methods

Qualitative semi‐structured interviews were carried out with 36 participants recruited from general practices as part of randomised controlled trials of online eczema resources.

Results

Changes to everyday life—Periods of staying at home due to the pandemic alter the burden of eczema, with reports of an improved routine and application of topical treatments for many, but difficulties with handwashing for others. Parents/carers reported improved eczema control due to closures of educational settings. Young people reported higher stress that may have triggered eczema flare‐ups. Changes to access to advice and treatment—There was a reluctance to seek medical appointments in a non‐emergency situation. Participants reported a lack of trust in the outcome of telephone consultations because health professionals were unable to see or feel the skin. Delays or difficulties when obtaining appointments and treatments caused frustration. Access to an online eczema resource was reported to have extra value in the context of the pandemic.

Conclusion

Changes to lifestyle and access to healthcare during the pandemic have affected eczema and self‐management. Healthcare settings may want to consider providing extra reassurance around remote consultations.

AB0251 INCREASED ACCUMULATION OF ERYTHROCYTE METHOTREXATE POLYGLUTAMATES DURING EARLY PHASE SUBCUTANEOUS VERSUS ORAL METHOTREXATE TREATMENT OF RHEUMATOID ARTHRITIS PATIENTS

Background:

Optimal dosing of methotrexate (MTX) for individual rheumatoid arthritis (RA) patients to achieve adequate disease control is an ongoing challenge. Assessment of erythrocyte MTX-polyglutamates (PGs) levels has been employed as a tool to monitor clinical response of RA patients in the first 3-12 months of treatment and MTX-PG2-4 and total MTX-PGs were associated with a lower DAS28 over 9 months.1 However, data from earlier time points, MTX-PG6 and per route of administration are unavailable.

Objectives:

To investigate the pharmacokinetics and -dynamics of erythrocyte MTX-PG accumulation in RA patients receiving oral or subcutaneous MTX in the early phase (1, 2, and 3 months) of MTX treatment initiation.

Methods:

In a clinical prospective cohort study (MeMo study (NTR7149)), newly diagnosed RA patients were administered oral (n=24) or subcutaneous (n=22) MTX, mostly according to the COBRA-light schedule (start 10 mg MTX, increased to 25 mg MTX in 8 weeks). At 1, 2, and 3 months after start of therapy, blood was collected and individual MTX-PGs (MTX-PG1 – MTX-PG6) were analyzed in erythrocytes at a minimal detection limit of 1 nmol/L, using a validated UHPLC-MS/MS method with labeled internal standards.1 Dosing, concomitant treatments and DAS28-ESR assessments were in conformity with clinical practice. Adverse events were recorded.

Results:

46 consecutive patients were included in this study; 76% female, mean age: 57.8 years, BMI: 25.8, 20% smokers, mean baseline DAS28-ESR: 3.5. Notwithstanding marked interpatient variability, patients starting subcutaneous MTX had accumulated significantly higher (approximately 2-fold) long chain MTX-PGs (MTX-PG4-6) when compared to patients in the oral MTX group at 1 and 2 months (Figure 1A, Table 1). Similarly, MTX-PG1-6 and MTX-PG3 accumulation were higher in subcutaneous MTX-users at month 1 (p=0.022 and p=0.011) compared to the oral group (median 68.6 nmol/L (IQR:40.5) vs 51.9 (55.6) and 17.4 (11.1) vs 11.2 (15.6), respectively (Figure 1B, Table 1).

Table 1.

Linear regression of MTX-PG levels and administration route, corrected for age, baseline DAS28, smoking, BMI, eGFR and MTX dose.

monthß (P-value)1ß (P-value)2ß (P-value)3MTX-PG1-61.65 (0.022)1.51 (0.073)1.30 (0.233)MTX-PG1,21.13 (0.599)1.19 (0.470)1.12 (0.623)MTX-PG31.75 (0.011)1.51 (0.071)1.19 (0.439)MTX-PG4-61.97 (0.036)2.04 (0.033)1.55 (0.136)

Mean MTX dose at baseline was 10.5mg (SD 1.5) for both groups, 15.4 (4.4) and 16.8 (1.8) at 1 month and 22.8 (3.9) and 22.4 (5.2) at 2 months for oral and subcutaneous use respectively.

DAS28 decreased with 1.6 in the oral group and 1.1 in the subcutaneous group (p=0.382). With and without corrections for age, baseline DAS28, eGFR, MTX dose (1 month before sampling), smoking and BMI, no significant relation between MTX-PG concentrations and DAS28 was observed during the first 3 months of treatment.

43 patients reported any side effect, mostly headache and dizziness, which was similar in both groups and uncorrelated with MTX-PG levels.

No association was found between MTX-PG1 levels and number of days between timing of blood withdrawal and last administration.

Figure 1.

Erythrocyte long chain MTX-PG(A) and total MTX-PG(B) accumulation in RA patients of the first 3 months of oral(C) or subcutaneous(D) MTX administration. At 3 months, 18 patients using oral and 18 patients using subcutaneous MTX were still continuing MTX treatment. Medians and IQR are depicted.

Conclusion:

This study shows the feasibility of measuring erythrocyte MTX-PGs early on in the treatment of RA patients with MTX and demonstrated significantly higher accumulation of MTX-PGs following subcutaneous versus oral MTX administration. Early phase erythrocyte MTX-PG analyses may hold potential for positioning in optimizing individual patient MTX dose scheduling.

References:

[1]de Rotte MC, et al. Methotrexate polyglutamates in erythrocytes are associated with lower disease activity in patients with rheumatoid arthritis. Ann Rheum Dis 2015(74):408-14.

Acknowledgements:

We would like to thank all participating patients and Pfizer (grant 53233663 / WI230458).

Disclosure of Interests:

Renske Hebing Grant/research support from: Pfizer, Ittai Muller: None declared, Marry Lin: None declared, Sohaila Mahmoud: None declared, Sandra Heil: None declared, WIllem Lems: None declared, Michael Nurmohamed: None declared, Robert De Jonge: None declared, Gerrit Jansen: None declared

OP0021 IDENTIFICATION OF DIFFERENTIALLY EXPRESSED GENES IN EARLY RHEUMATOID ARTHRITIS PATIENTS RESPONDING TO TOCILIZUMAB

Background:

Tocilizumab (TCZ) is a monoclonal antibody that binds to the interleukin 6 receptor (IL-6R), inhibiting IL-6R signal transduction to downstream inflammatory mediators. TCZ has shown to be effective as monotherapy in early rheumatoid arthritis (RA) patients (1). However, approximately one third of patients inadequately respond to therapy and the biological mechanisms underlying lack of efficacy for TCZ remain elusive (1). Here we report gene expression differences, in both whole blood and peripheral blood mononuclear cells (PBMC) RNA samples between early RA patients, categorized by clinical TCZ response (reaching DAS28 < 3.2 at 6 months). These findings could lead to identification of predictive biomarkers for TCZ response and improve RA treatment strategies.

Objectives:

To identify potential baseline gene expression markers for TCZ response in early RA patients using an RNA-sequencing approach.

Methods:

Two cohorts of RA patients were included and blood was collected at baseline, before initiating TCZ treatment (8 mg/kg every 4 weeks, intravenously). DAS28-ESR scores were calculated at baseline and clinical response to TCZ was defined as DAS28 < 3.2 at 6 months of treatment. In the first cohort (n=21 patients, previously treated with DMARDs), RNA-sequencing (RNA-seq) was performed on baseline whole blood PAXgene RNA (Illumina TruSeq mRNA Stranded) and differential gene expression (DGE) profiles were measured between responders (n=14) and non-responders (n=7). For external replication, in a second cohort (n=95 therapy-naïve patients receiving TCZ monotherapy), RNA-seq was conducted on baseline PBMC RNA (SMARTer Stranded Total RNA-Seq Kit, Takara Bio) from the 2-year, multicenter, double-blind, placebo-controlled, randomized U-Act-Early trial (ClinicalTrials.gov identifier: NCT01034137) and DGE was analyzed between 84 responders and 11 non-responders.

Results:

Whole blood DGE analysis showed two significantly higher expressed genes in TCZ non-responders (False Discovery Rate, FDR < 0.05): urotensin 2 (UTS2) and caveolin-1 (CAV1). Subsequent analysis of U-Act-Early PBMC DGE showed nine differentially expressed genes (FDR < 0.05) of which expression in clinical TCZ non-responders was significantly higher for eight genes (MTCOP12, ZNF774, UTS2, SLC4A1, FECH, IFIT1B, AHSP, and SPTB) and significantly lower for one gene (TND2P28M). Both analyses were corrected for baseline DAS28-ESR, age and gender. Expression of UTS2, with a proposed function in regulatory T-cells (2), was significantly higher in TCZ non-responders in both cohorts. Furthermore, gene ontology enrichment analysis revealed no distinct gene ontology or IL-6 related pathway(s) that were significantly different between TCZ-responders and non-responders.

Conclusion:

Several genes are differentially expressed at baseline between responders and non-responders to TCZ therapy at 6 months. Most notably, UTS2 expression is significantly higher in TCZ non-responders in both whole blood as well as PBMC cohorts. UTS2 could be a promising target for further analyses as a potential predictive biomarker for TCZ response in RA patients in combination with clinical parameters (3).

References:

[1]Bijlsma JWJ, Welsing PMJ, Woodworth TG, et al. Early rheumatoid arthritis treated with tocilizumab, methotrexate, or their combination (U-Act-Early): a multicentre, randomised, double-blind, double-dummy, strategy trial. Lancet. 2016;388(10042):343-55.

[2]Bhairavabhotla R, Kim YC, Glass DD, et al. Transcriptome profiling of human FoxP3+ regulatory T cells. Human Immunology. 2016;77(2):201-13.

[3]Gosselt HR, Verhoeven MMA, Bulatovic-Calasan M, et al. Complex machine-learning algorithms and multivariable logistic regression on par in the prediction of insufficient clinical response to methotrexate in rheumatoid arthritis. Journal of Personalized Medicine. 2021;11(1).

Disclosure of Interests:

None declared

Asymmetry indicates more severe and active disease in Graves' orbitopathy: results from a prospective cross-sectional multicentre study

PURPOSE

Patients with Graves' orbitopathy can present with asymmetric disease. The aim of this study was to identify clinical characteristics that distinguish asymmetric from unilateral and symmetric Graves' orbitopathy.

METHODS

This was a multi-centre study of new referrals to 13 European Group on Graves' Orbitopathy (EUGOGO) tertiary centres. New patients presenting over a 4 month period with a diagnosis of Graves' orbitopathy were included. Patient demographics were collected and a clinical examination was performed based on a previously published protocol. Patients were categorized as having asymmetric, symmetric, and unilateral Graves' orbitopathy. The distribution of clinical characteristics among the three groups was documented.

RESULTS

The asymmetric group (n = 83), was older than the symmetric (n = 157) group [mean age 50.9 years (SD 13.9) vs 45.8 (SD 13.5), p = 0.019], had a lower female to male ratio than the symmetric and unilateral (n = 29) groups (1.6 vs 5.0 vs 8.7, p < 0.001), had more active disease than the symmetric and unilateral groups [mean linical Activity Score 3.0 (SD 1.6) vs 1.7 (SD 1.7), p < 0.001 vs 1.3 (SD 1.4), p < 0.001] and significantly more severe disease than the symmetric and unilateral groups, as measured by the Total Eye Score [mean 8.8 (SD 6.6) vs 5.3 (SD 4.4), p < 0.001, vs 2.7 (SD 2.1), p < 0.001].

CONCLUSION

Older age, lower female to male ratio, more severe, and more active disease cluster around asymmetric Graves' orbitopathy. Asymmetry appears to be a marker of more severe and more active disease than other presentations. This simple clinical parameter present at first presentation to tertiary centres may be valuable to clinicians who manage such patients.

Comparison of single- and multi-trait approaches to identify best wild candidates for aquaculture shows that the simple way fails

In agriculture, diversifying production implies picking up, in the wild biodiversity, species or populations that can be domesticated and fruitfully produced. Two alternative approaches are available to highlight wild candidate(s) with high suitability for aquaculture: the single-trait (i.e. considering a single phenotypic trait and, thus, a single biological function) and multi-trait (i.e. considering multiple phenotypic traits involved in several biological functions) approaches. Although the former is the traditional and the simplest method, the latter could be theoretically more efficient. However, an explicit comparison of advantages and pitfalls between these approaches is lacking to date in aquaculture. Here, we compared the two approaches to identify best candidate(s) between four wild allopatric populations of Perca fluviatilis in standardised aquaculture conditions. Our results showed that the single-trait approach can (1) miss key divergences between populations and (2) highlight different best candidate(s) depending on the trait considered. In contrast, the multi-trait approach allowed identifying the population with the highest domestication potential thanks to several congruent lines of evidence. Nevertheless, such an integrative assessment is achieved with a far more time-consuming and expensive study. Therefore, improvements and rationalisations will be needed to make the multi-trait approach a promising way in the aquaculture development.

Young people's perceptions of acne and acne treatments: secondary analysis of qualitative interview data

Background

Acne vulgaris is a common skin condition affecting approximately 95% of adolescents to some extent. First‐line treatments are topical preparations but nonadherence is common. A substantial proportion of patients take long courses of oral antibiotics, associated with antibiotic resistance.

Objectives

This study aimed to explore young people's views and experiences of acne and its treatments.

Methods

We report a secondary thematic analysis of interview data collected by researchers in the Health Experiences Research Group (HERG), University of Oxford. A total of 25 transcripts from young people aged 13–24 years with acne were included.

Results

Acne is often perceived as a short‐term self‐limiting condition of adolescence and this appears to have implications for seeking treatment or advice. Participants widely perceived topical treatments as being ineffective, which seemed related to unrealistic expectations around speed of onset of action. Many participants felt they had tried all available topical treatments, although were unsure what was in them or unaware of differences between cosmetic and pharmaceutical treatments. They had concerns around how to use topicals ‘properly’ and how to avoid side‐effects. They were also concerned about the side‐effects or necessity of oral treatments, although few seemed aware of antibiotic resistance.

Conclusions

People with acne need support to manage their condition effectively, particularly a better understanding of different topicals, how to use them and how to avoid side‐effects. Unrealistic expectations about the onset of action of treatments appears to be a common cause of frustration and nonadherence. Directing people towards accessible evidence‐based information is crucial.

What's already known about this topic?

There is a common perception that acne is a short‐term condition that will resolve without treatment.

Previous research has shown that nonadherence to topical treatments is common and that oral antibiotics are the most commonly prescribed treatment for acne in the U.K.

Further research is needed to understand how young people perceive acne treatments and the implications of this for treatment adherence and self‐management.

What does this study add?

People often said they had tried all available topical preparations for acne, but seemed confused between cosmetic and pharmaceutical treatments.

People seemed unsure how to use topical treatments ‘properly’ or how to avoid side‐effects. This was rarely discussed with health professionals.

People's perception of acne as a short‐term condition appeared to influence their expectations around onset of action of treatment and their views about its effectiveness and necessity.

What are the clinical implications of the work?

The perception of acne as a short‐term condition has implications for self‐management and motivation to seek and adhere to treatments.

Providing advice about onset of action of treatments and how to prevent side‐effects is crucial, including directing people towards accessible, written, evidence‐based information.

People's confusion about the different topical treatments available may be alleviated by such information, or by encouraging photos or other recordings of treatments tried and for how long.

Linked Comment: Prior. Br J Dermatol 2020; 183:208–209.

Linked Comment: Prior. Br J Dermatol 2020; 183:208–209.

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Vision of a near future: Bridging the human health-environment divide. Toward an integrated strategy to understand mechanisms across species for chemical safety assessment

There is a growing recognition that application of mechanistic approaches to understand cross-species shared molecular targets and pathway conservation in the context of hazard characterization, provide significant opportunities in risk assessment (RA) for both human health and environmental safety. Specifically, it has been recognized that a more comprehensive and reliable understanding of similarities and differences in biological pathways across a variety of species will better enable cross-species extrapolation of potential adverse toxicological effects. Ultimately, this would also advance the generation and use of mechanistic data for both human health and environmental RA. A workshop brought together representatives from industry, academia and government to discuss how to improve the use of existing data, and to generate new NAMs data to derive better mechanistic understanding between humans and environmentally-relevant species, ultimately resulting in holistic chemical safety decisions. Thanks to a thorough dialogue among all participants, key challenges, current gaps and research needs were identified, and potential solutions proposed. This discussion highlighted the common objective to progress toward more predictive, mechanistically based, data-driven and animal-free chemical safety assessments. Overall, the participants recognized that there is no single approach which would provide all the answers for bridging the gap between mechanism-based human health and environmental RA, but acknowledged we now have the incentive, tools and data availability to address this concept, maximizing the potential for improvements in both human health and environmental RA.

'It's like the bad guy in a movie who just doesn't die': a qualitative exploration of young people's adaptation to eczema and implications for self-care

BACKGROUND

Eczema is a common childhood inflammatory skin condition, affecting more than one in five children. A popular perception is that children 'outgrow eczema', although epidemiological studies have shown that, for many, eczema follows a lifelong episodic course.

OBJECTIVES

To explore the perceptions of young people about the nature of their eczema and how these perceptions relate to their self-care and adapting to living with eczema.

METHODS

This is a secondary inductive thematic analysis of interviews conducted for Healthtalk.org. In total 23 interviews with young people with eczema were included. Of the 23 participants, 17 were female and six male, ranging from 17 to 25 years old.

RESULTS

Participants generally experienced eczema as an episodic long-term condition and reported a mismatch between information received about eczema and their experiences. The experience of eczema as long term and episodic had implications for self-care, challenging the process of identifying triggers of eczema flare-ups and evaluating the success of treatment regimens. Participants' experiences of eczema over time also had implications for adaptation and finding a balance between accepting eczema as long term and hoping it would go away. This linked to a gradual shift in treatment expectations from 'cure' to 'control' of eczema.

CONCLUSIONS

For young people who continue to experience eczema beyond childhood, a greater focus on self-care for a long-term condition may be helpful. Greater awareness of the impact of early messages around 'growing out of' eczema and provision of high-quality information may help patients to manage expectations and support adaptation to treatment regimens. What's already known about this topic? There is a common perception that people 'grow out of' eczema, but for many people eczema follows a lifelong episodic course. Qualitative work has shown that parents can find that being told their child will grow out of eczema is dismissive, and that they have difficulty with messages about 'control not cure' of eczema. It is unclear how young people perceive their eczema and the implications of this perception for their adaptation and self-care. What does this study add? The message that many people 'grow out of' eczema has a potentially detrimental effect for young people where the condition persists. This has implications for young people's perceptions of their eczema, their learning to self-care and how they adapt to living with eczema and eczema treatments. What are the clinical implications of this work? Clinicians need to promote awareness among young people that eczema is a long-term episodic condition in order to engage them with effective self-care. Young people transitioning to self-care need evidence-based information that is specific and relatable to them.

Patients' understanding of cellulitis and views about how best to prevent recurrent episodes: mixed-methods study in primary and secondary care

BACKGROUND

Cellulitis is a common painful infection of the skin and underlying tissues that recurs in approximately one-third of cases. The only proven strategy to reduce the risk of recurrence is long-term, low-dose antibiotics. Given current concerns about antibiotic resistance and the pressure to reduce antibiotic prescribing, other prevention strategies are needed.

OBJECTIVES

To explore patients' views about cellulitis and different ways of preventing recurrent episodes.

METHODS

Adults aged ≥ 18 years with a history of first-episode or recurrent cellulitis were invited through primary care, hospitals and advertising to complete a survey, take part in an interview or both.

RESULTS

Thirty interviews were conducted between August 2016 and July 2017. Two hundred and forty surveys were completed (response rate 17%). Triangulation of quantitative and qualitative data showed that people who have had cellulitis have wide-ranging beliefs about what can cause cellulitis and are often unaware of risk of recurrence or potential strategies to prevent recurrence. Enhanced foot hygiene, applying emollients daily, exercise and losing weight were more popular potential strategies than the use of compression stockings or long-term antibiotics. Participants expressed caution about long-term oral antibiotics, particularly those who had experienced only one episode of cellulitis.

CONCLUSIONS

People who have had cellulitis are keen to know about possible ways to prevent further episodes. Enhanced foot hygiene, applying emollients daily, exercise and losing weight were generally viewed to be more acceptable, feasible strategies than compression or antibiotics, but further research is needed to explore uptake and effectiveness in practice.

Changes in neuromuscular activity during motor training with a body-machine interface after spinal cord injury

Body machine interfaces (BMIs) are used by people with severe motor disabilities to control external devices, but they also offer the opportunity to focus on rehabilitative goals. In this study we introduced in a clinical setting a BMI that was integrated by the therapists in the rehabilitative treatments of 2 spinal cord injured (SCI) subjects for 5 weeks. The BMI mapped the user's residual upper body mobility onto the two coordinates of a cursor on a screen. By controlling the cursor, the user engaged in playing computer games. The BMI allowed the mapping between body and cursor spaces to be modified, gradually challenging the user to exercise more impaired movements. With this approach, we were able to change our subjects' behavior, who initially used almost exclusively their proximal upper body-shoulders and arms - for using the BMI. By the end of training, cursor control was shifted toward more distal body regions - forearms instead of upper arms - with an increase of mobility and strength of all the degrees of freedom involved in the control. The clinical tests and the electromyographic signals from the main muscles of the upper body confirmed the positive effect of the training. Encouraging the subjects to explore different and sometimes unusual movement combinations was beneficial for recovering distal arm functions and for increasing their overall mobility.

Views of oral antibiotics and advice seeking about acne: a qualitative study of online discussion forums

BACKGROUND

Acne vulgaris is common and can significantly impair quality of life, yet little is known about patients' understanding of acne and its treatments. Oral antibiotics are widely used for acne despite concerns about antibiotic resistance. People are increasingly turning to online discussion forums for advice, and information on these sites may influence health beliefs and treatment adherence.

OBJECTIVES

To explore understandings about the use of oral antibiotics for acne and advice shared among messages posted on online forums.

METHODS

We systematically searched for online forums and identified four where acne was frequently discussed. Discussion threads relating to oral antibiotics were analysed thematically.

RESULTS

We extracted 136 pages of data comprising 65 discussions among 294 participants. We found a wide range of perceptions around effectiveness of antibiotics for acne and concerns about adverse effects. The delayed onset of action of antibiotics was a source of frustration and compounded dissatisfaction with healthcare providers, who were perceived by people as 'fobbing them off' with prolonged courses of ineffective treatment. Advice ranged from when to ask for or insist on referral to use of costly cleansers. Forum posts related to a wide range of severities, from 'spots' to severe acne, which may make it confusing for users to assess appropriateness of information.

CONCLUSIONS

Online forums offer opinions that could confuse patients, or lead to early abandonment of treatments, challenging consultations and patient dissatisfaction. Users expressed frustration about the delayed onset of action of antibiotics for acne, perceptions of only temporary effectiveness and adverse effects.

Parents' and carers' views about emollients for childhood eczema: qualitative interview study

OBJECTIVE

Leave-on emollients form the mainstay of eczema treatment, but adherence is poor. We aimed to explore parents'/carers' views on effectiveness and acceptability of leave-on emollients for childhood eczema through secondary analysis of data from 2 qualitative data sets.

SETTING

Study 1 recruited through mail-out from 6 general practices in southern England. Study 2 recruited from a feasibility trial of an intervention to support eczema self-care in 31 practices in the same area.

PARTICIPANTS

Study 1 included 28 interviews with carers of children aged ≤5 years with eczema. Study 2 included 26 interviews with carers of children aged ≤5 years with eczema.

METHODS

Interviews followed semistructured guides: study 1 explored carers' understandings around eczema treatments in order to develop a web-based self-care support intervention; study 2 explored carers' understandings of eczema and eczema treatments after using the intervention. Interviews were carried out face to face or by telephone, audio-recorded and transcribed. Secondary analysis of data from both studies focused on views and experiences of emollient use. Data were analysed using an inductive thematic approach facilitated by NVivo V.10 software.

RESULTS

In study 1, most participants felt emollients improved eczema but held mixed views about long-term use to prevent flare-ups. In study 2, where carers had used the web-based intervention, all participants held positive views about long-term emollient use. In both studies, participants expressed a range of preferences about emollient 'thickness'; some felt that 'thick' emollients (ointments) were most effective, while others found these difficult to use. Carers described a process of 'trial and error', trying emollients suggested by professionals, friends and family, or bought over-the-counter. Carers expressed a need for understanding differences between products and their effective use.

CONCLUSIONS

Providing a rationale for long-term emollient use and choice of emollients could help improve adherence and help families gain more rapid control of eczema.

Comparing acute and chronic human cutaneous leishmaniasis caused by Leishmania major and Leishmania tropica focusing on arginase activity

BACKGROUND

Cutaneous leishmaniasis (CL) in Iran is mainly caused by Leishmania major (L. major) and L. tropica. Arginase mediated L-arginine metabolism is an important issue in Leishmania parasite propagation. Arginase activity in human CL due to L. major and L. tropica have not been studied up to now.

OBJECTIVES

We aimed to compare the clinical and laboratory aspects of acute and chronic CL, focussing on arginase activity.

METHODS

In this case-control study, 30 patients with acute CL (duration ≤ 1 year), 13 patients with chronic CL (duration ≥ 2 year) and 11 healthy controls were recruited. Arginase activity was measured in skin biopsies of lesions, peripheral blood polymorphonuclear cells (PMNs), peripheral blood mononuclear cells (PBMCs) and plasma by standard methods.

RESULTS

The median of arginase activity in the acute lesions was higher than in chronic samples and significantly higher than in healthy controls (P = 0.008). PMNs of both acute and chronic patients showed higher levels of arginase activity as compared to the levels in PBMCs and plasma. The median of arginase activity in the PMNs of patients with chronic CL was higher than that of patients with acute CL and significantly higher than that of the healthy controls (P = 0.010).

CONCLUSION

The level of arginase activity in lesions of patients with acute and chronic CL was higher than the skin of healthy controls. The highest level of arginase activity was observed in PMNs from patients with chronic CL. This suggests that the high level of arginase activity in PMNs of patients with chronic CL may contribute to the chronicity.

The sodium iodide symporter is unlikely to be a thyroid/breast shared antigen

PURPOSE

Anti-thyroid peroxidase (TPO) autoantibodies (TPOAb) seem to be protective for patients with breast cancer (BC). Thyroid and breast tissues both express the sodium iodide symporter (NIS), similarly both have a peroxidase activity, TPO and lactoperoxidase (LPO) respectively. We hypothesize a common immune response to a thyroid/breast shared antigen suggesting three putative mechanisms: (1) TPOAb react to both TPO and LPO, (2) TPO could be expressed in BC and (3) patients with TPOAb could have autoantibodies to NIS (NISAb). Previous studies excluded NISAb that block NIS activity in sera of patients with thyroid autoimmunity (TA) and/or BC. This study investigates neutral NISAb (binding without affecting function).

METHODS

Clones of CHO cells stably expressing human NIS (hNIS; CHO-NIS) were isolated following transfection of hNIS in pcDNA3 vector. Expression of hNIS mRNA and surface protein was confirmed by PCR and flow cytometry respectively using a hNIS-mouse-monoclonal-antibody. CHO-NIS and controls transfected with the empty pcDNA3 vector (CHO-Empty) were incubated with 42 heat-inactivated human sera followed by an anti-human-IgG-AlexaFluor488-conjugate: 12 with BC, 11 with TA, 10 with both BC and TA and 9 with non-autoimmune thyroid diseases. The Kolmogorov-Smirnov Test was used to compare the fluorescence intensity obtained with CHO-NIS and CHO-Empty, using sera from six young males as a negative control population.

RESULTS

None of the 42 sera were positive for NISAb.

CONCLUSIONS

NISAb are rare and NIS is unlikely to be a common thyroid/BC shared antigen. We have recently demonstrated TPO expression in BC tissue and are currently investigating TPOAb cross-reactivity with TPO/LPO.

Does thyroid peroxidase provide an antigenic link between thyroid autoimmunity and breast cancer?

Women with breast cancer (BC) and antithyroid peroxidase (TPO) autoantibodies (TPOAb) have a better prognosis than women lacking TPOAb. Sera from women with TPOAb displayed immunoreactivity to BC tissue by immunofluorescence that was not apparent in women without TPOAb. We hypothesize a BC/thyroid shared antigen that provides a target for humoral or cell-mediated immune activity; candidates include the sodium/iodide symporter (expressed in thyroid and BC), cross-reacting epitopes in TPO and lactoperoxidase (LPO) or TPO itself. As the association is with TPOAb, we investigated TPO expression in BC, breast peritumoral tissue (PT), other tissues (tumoral and not) and thyroid as positive control. Transcripts for known and novel TPO isoforms were detected in BC (n = 8) and PT (n = 8) but at approximately 10(4) -fold lower than in thyroid while in non-BC tumors (n = 5) they were at the limit of detection. TPO was expressed also in adipose tissue (n = 17), 10(3) -fold lower than in thyroid. Full length TPO (Mr 105-110 kDa) was detected in Western blots in the majority of examined tissues; preabsorption of the TPO antibody with recombinant TPO (but not LPO) reduced the signal, indicating specificity. The same occurred with some lower molecular weight bands, which could correspond to smaller TPO transcript isoforms, present in all samples. In conclusion, TPO is weakly expressed in BC and other tissues; this could partly explain the high frequency and protective role of TPOAb in BC patients. Further studies will investigate tissue specificity, function and immunogenicity of the novel TPO variants (some BC-specific) identified.

Is the risk of primary hyperparathyroidism increased in patients with untreated breast cancer?

BACKGROUND

An increased frequency of primary hyperparathyroidism (PHP) has been reported in patients with treated breast cancer (BC). PHP has been found in about 7% of BC patients after surgery and radio-, chemio- or hormonal therapy.

AIM

To evaluate the frequency of PHP in untreated BC patients.

SUBJECTS AND METHODS

We evaluated 186 women with BC and 233 women with thyroid cancer (TC, no.=122) or benign thyroid diseases (BTD, no.=111). In all patients, serum calcium, albumin, PTH, and 25-hydroxyvitamin D (25-OH vitD) were measured before any treatment.

RESULTS

Serum calcium concentrations were significantly higher in BC than in TC and BTD groups (median values 9.5 mg/dl, 9.3 mg/dl and 9.3 mg/dl, respectively) but, according to a logistic regression model, calcium was not significantly different between the 3 groups when age was taken into account. In all patients, serum calcium was in the normal range, indicating that no case of overt PHP was present. Five patients (1 in BC, 2 in TC, and 2 in BDT groups) had serum calcium close to the upper limit of normal range, high PTH and low 25-OH vitD, indicating a possible PHP with hypercalcemia masked by concomitant 25-OH vitD deficiency.

CONCLUSIONS

In untreated BC group, no patient had overt PHP and 1/186 (0.5%) presented a possible PHP masked by 25-OH vitD deficiency, a PHP frequency much lower than that observed in treated BC patients. These data suggest that the treatments of BC may be responsible for the increased frequency of PHP reported in previous studies.

High prevalence of breast cancer in patients with benign thyroid diseases

BACKGROUND

In patients with breast cancer (BC) a high prevalence of benign thyroid diseases (BTD) has been described, Hashimoto's thyroiditis accounting to a large extent for this association. The aim of this study was to evaluate the prevalence of BC in a large group of patients with BTD.

PATIENTS

Clinical records of 622 consecutive patients with BTD were examined. BC prevalence in BTD patients was compared with BC frequency in general population living in the same country.

RESULTS

BC prevalence in patients with BTD (38/622; 6.11%) was significantly higher (p=0.0002) compared to BC frequency in general population (2.07%). When patients were divided according to the age of menopause, in females older than 49 yr BC frequency in BTD was significantly higher than in age-matched population (7.6 vs 3.3%; p=0.006), while in females aged 30-49 yr BC frequency in BTD was higher, but not statistically significantly, than in agematched population (3.7 vs 0.5%; p=0.06). No significant difference in BC prevalence was found when patients were grouped according to the diagnosis of thyroid disorders: Graves' disease, Hashimoto's thyroiditis, nodular goiter associated or not associated with serum thyroid autoantibodies (TAb). No significant difference in BC frequency was observed between TAb+ (26/377; 6.9%) and TAb- (12/245; 4.9%) patients. The distribution of known risk factors for breast malignancies was similar in patients with or without BC.

CONCLUSION

In patients with BTD the prevalence of BC is significantly higher than the expected, showing the usefulness of screening for breast malignancy of patients with BTD.

[Horse milking industry in The Netherlands and Flanders]

The horse milking industry is expanding in The Netherlands and Flanders. Horse milk has become popular due to its (supposed) health-enhancing properties. A horse-milking farm is not a common client for the Dutch veterinarian. When giving advice in this circumstance it should be recognised that these horses are production animals and that their milk is for human consumption. A review of the literature is given together with the results of an extensive enquiry amongst 13 horse-milking farms in The Netherlands and Flanders.

Favorable predictive value of thyroid autoimmunity in high aggressive breast cancer

A high incidence of anti-thyroid antibodies (TAb) has been found in patients with breast cancer (BC). The aim of this study was to evaluate the prognostic value of TAb in a group of 47 women submitted to mastectomy for high malignancy degree BC. All patients were evaluated for thyroid disorders after breast surgery and before any anti-tumoral adjuvant therapy. Five yr after BC diagnosis 31/47 (65.9%) patients were alive (survivors group: SG) and 16/47 (34.1%) were dead (deaths group: DG). The overall prevalence of TAb was 15/47 (31.9%): 14/31 (45.1%) in SG and 1/16 (6.2%) in DG (p=0.008). Five-yr mortality was 15/32 (46.9%) in TAb- and 1/15 (6.7%) in TAb+ patients (p=0.01). Eight out of 47 (17.0%) patients had Hashimoto's thyroiditis and 7 of them (87.5%) were in SG. Estrogen receptor (ER) was measured in 43/47 (91.5%) BC specimens. ER was detected in 19/30 (63.0%) patients in SG and 3/13 (23.1%) in DG (p=0.01). Five-yr mortality was 10/21 (47.6%) in ER- and 3/22 (13.6%) in ER+ patients (p=0.008). Absence of ER expression [odds ratio (OR) 6.54; p=0.006] and absence of TAb (OR 9.37; p=0.03) were related to a higher mortality rate. TAb were detected in 8/21 (38.1%) ER- and in 7/22 (31.8%) ER+ patients; no relation was found between ER expression and TAb positivity (p=ns). Patients with ER+ and TAb+ have a better prognosis and the absence of a significant relationship between these two parameters suggests an independent prognostic role in high malignancy degree BC women.

Incorporation of phytosterols in human keratinocytes

We have designed experimental conditions allowing the replacement of 50% of cholesterol of human keratinocytes (SVK14 line) with sitosterol or stigmasterol without affecting cellular viability. We have investigated the influence of incorporating phytosterol on the ultraviolet-A-induced formation of lipid-peroxidation products (thiobarbituric reactive substances (TBARS)) in these cells. Our results show that ultraviolet-A-induced lipid peroxidation depends on the nature of the phytosterol. Sitosterol induces a significant decrease (-30%) of TBARS relative to the control whereas stigmasterol markedly increases lipid peroxidation (+70%). We have also studied the effect of plant sterols on prostaglandin release by using the Ca(2+) ionophore A23187 as an in vitro model of the inflammation induced by UVA radiation. We show that in the presence of 50% of phytosterol (particularly stigmasterol), the release of prostaglandin (6-ketoPG(1alpha), PGE(2)) is increased compared to untreated cells. This pro-inflammatory effect of phytosterols is correlated with a loss of the regulation of the intracellular Ca(2+) concentration.

Recombinant G protein-coupled receptors from expression to renaturation: a challenge towards structure

G protein-coupled receptors (GPCRS) represent a class of integral membrane proteins involved in many biological processes and pathologies. Fifty percent of all modern drugs and almost 25% of the top 200 bestselling drugs are estimated to target GPCRs. Despite these crucial biological implications, very little is known, at atomic resolution, about the detailed molecular mechanisms by which these membrane proteins are able to recognize their extra-cellular stimuli and transmit the associated messages. Obviously, our understanding of GPCR functioning would be greatly facilitated by the availability of high-resolution three-dimensional (3D) structural data. However, expression, solubilization and purification of these membrane proteins are not easy to achieve, and at present, only one 3D structure has been determined, that of bovine rhodopsin. This review presents and compares the different successful strategies which have been applied to solubilize and purify recombinant GPCRs in the perspective of structural biology experiments.

Bayesian age-stage modelling of Plasmodium falciparum sequestered parasite loads in severe malaria patients

A discrete-time age-stage model is proposed for estimating the number of sequestered parasites in severe malaria patients. A Bayesian Markov chain Monte Carlo (MCMC) approach is used to model the dynamics of Plasmodium falciparum parasitaemia in 107 paediatric patients in a randomized controlled trial of quinine and artemether in Kenya, in whom 4-hourly peripheral parasitaemia determinations were made. The MCMC approach allows the model to be fitted simultaneously to the entire dataset, providing point and interval estimates for both population and individual patient parameters. Analysis of a simulated dataset indicated that the models gave good estimates of the distribution of parasites between different stages on enrolment, for patients with a wide range of initial states. The analysis of the Kenyan patients suggested that there is considerable variation between patients within the same centre, in both the proportion of sequestered parasites and the intrinsic rate of increase of the parasite population in the absence of treatment. The resulting models should prove a useful tool for cross-validating biochemical approaches for estimating the sequestered load.

Enhanced in vivo platelet adhesion in vasodilator-stimulated phosphoprotein (VASP)-deficient mice

Platelet adhesion and activation at the vascular wall are the initial steps leading to arterial thrombosis and vascular occlusion. Prostacyclin and nitric oxide inhibit platelet adhesion, acting via cyclic adenosine monophosphate (cAMP)- and cyclic guanosine monophosphate (cGMP)-dependent protein kinases. A major downstream target for both cAMP- and cGMP-dependent protein kinases is the vasodilator-stimulated phosphoprotein (VASP). To test the significance of VASP for the regulation of platelet adhesion in vivo, we studied platelet-vessel wall interactions using VASP-deficient (VASP-/-) mice. Under physiologic conditions, platelet adhesion to endothelial cells was significantly enhanced in VASP null mutants when compared with wild-type mice (P <.05). Platelet recruitment in VASP null mice involved P-selectin and the fibrinogen receptor glycoprotein IIb-IIIa (GPIIb-IIIa). Under pathophysiologic conditions, the loss of VASP increased platelet adhesion to the postischemic intestinal microvasculature, to the atherosclerotic endothelium of ApoE-deficient mice, and to the subendothelial matrix following endothelial denudation (P <.05 vs wild type). Importantly, platelet adhesion in VASP null mutants was unresponsive to nitric oxide. These data show for the first time in vivo that VASP is involved in down-regulation of platelet adhesion to the vascular wall under both physiologic and pathophysiologic conditions.