In vitro aflatoxins recovery after changing buffer or protozoa concentrations in the rumen fermentation fluid

This study simulates in vitro the effects of (i) rumen acidity and (ii) change in rumen protozoa numbers on the recovery of aflatoxins (AFs). Two 24-h fermentation experiments were carried out using the same batch in vitro fermentation systems and substrate (dried corn meal) containing 11.42, 2.42, 7.65 and 1.70 µg/kg of AFB1, AFB2, AFG1 and AFG2 respectively. In Experiment 1, two buffer concentrations (normal salts dosage or lowered to 25%) were tested. Buffer reduction decreased gas production (730 vs. 1101 mL, p < 0.05), volatile fatty acids (VFA) and NH3 concentrations in the fermentation liquid (39.8 vs. 46.3 mmol/L, and 31.7 vs. 46.5 mg/dL respectively, p < 0.01). Recovery of all four AFs types was higher (p < 0.01) in the reduced buffer fermentation fluid, both as a percentage of total AF incubated (73.6% vs. 62.5%, 45.9% vs. 38.1%, 33.6% vs. 17.9% and 18.9% vs. 6.24% for AFB1, AFB2, AFG1 and AFG2 respectively) and as amounts relative to VFA production (163.4 vs. 123.5, 22.1 vs. 15.7, 48.8 vs. 22.5 and 6.16 vs. 1.86 ng/100 mmol of VFA, for AFB1, AFB2, AFG1 and AFG2 respectively). In Experiment 2, Stevia rebaudiana Bertoni extracts (S) or a Camphor essential oil (Cam) were added to fermenters and compared to the control (no additives, C). S and Cam addition resulted in a 25% reduction (p < 0.05) and a 15% increase (p < 0.05) in protozoa counts respectively, when compared to C. Both plant additives slightly reduced (p < 0.05) AFB1 recovery as a percentage of total AFB1 incubated (68.5% and 67.7% vs. 74.9% for S, Cam and C respectively). Recoveries of all other AFs were unaffected by the additives. In conclusion, the rumen in vitro AFB1 recovery (63%-75%) was higher than other AFs (3%-46%) and the acidic fermentation environment increased it. In our conditions, changes in protozoa numbers did not affect AFs recovery.

Fatty acids stable carbon isotope fractionation in the bovine organism. A compound-specific isotope analysis through gas chromatography combustion isotope ratio mass spectrometry

The contribution of dietary fatty acids to the quality of the meat and their path through the bovine organism is currently the subject of a lot of research. Stable isotope ratio analysis represents a powerful tool for this aim, one that has not been studied in depth yet. In this work, for the first time, the carbon isotopic ratios of six fatty acids (myristic 14:0, palmitic 16:0, stearic 18:0, oleic 18:1n-9, linoleic 18:2n-6 and linolenic 18:3n-3 acids) in different matrixes (diet, rumen, duodenal content, liver and loin) were analysed through gas chromatography combustion isotope ratio mass spectrometry. Moreover, the quantification of the single fatty acids was carried out, providing important information supporting the carbon isotopic ratio results. The variation in the concentration of the fatty acids in the different matrices depends on the chemical modifications they undergo in the sequential steps of the metabolic path. GC-C-IRMS turned out to be a powerful tool to investigate the fate of dietary fatty acids, providing information about the processes they undergo inside the bovine organism.

THU0265 THYMIC STROMAL LYMPHOPOIETIN (TSLP) AS A BIOMARKER OF PRIMARY SJÖGREN’S SYNDROME (PSS) AND RELATED LYMPHOMA: VALIDATION IN INDEPENDENT COHORTS

Background:

Thymic stromal lymphopoietin (TSLP) has been implicated in primary Sjögren’s syndrome (pSS) and related B-cell lymphoproliferation/lymphoma (NHL) by tissue studies on salivary glands (SG) (1). It resulted significantly higher in the serum of pSS patients compared to non-pSS sicca and to healthy subjects, with the highest levels found in NHL.

Objectives:

The purpose of this work was to confirm that serum TSLP is elevated in pSS by the study of independent cohorts.

Methods:

Serum TSLP levels were measured by ELISA in 91 pSS patients (F=86, 94.5%; mean age 57.2 years, 25-80) from the Udine cohort (cohort 1, UD), Italy. One additional multicentre cohort (cohort 2) from the Italian SS Study Group (GRISS) was studied, including 125 pSS patients from the Universities of Roma (RO), L’Aquila (L’AQ), Pisa (PI) and Perugia (PG). pSS patients with active NHL (n=12 in cohort 1; n=1 in cohort 2) were excluded from comparative analyses to avoid bias. Secondly, additional serum samples from pSS-related NHL in stable and complete remission, from both cohort 1 and 2, were analysed in a separate subgroup (n = 12). Thirdly, a preliminary evaluation of serum TSLP was performed in pSS patients from a different geographical area (University of Athens, Greece; cohort 3).

Results:

Cohort 2 included 125 pSS patients (F=114, 91.2%; mean age 58.1 years, 23-84): 124 benign, 1 with NHL. In this cohort, serum TSLP levels were confirmed to be high (mean 30.26 pg/mL, 0.41-95.21) and comparable to cohort 1 (mean 33.81 pg/mL, 0-140.8; p=ns). No difference was found by the separate analysis of pSS from each single Centres (RO n=49, mean 33.21, 1.4-95.21; L’AQ n=34, mean 38.6, 16.31-85.11; PI n=28, mean 20.23, 0.41-56.67; PG n=13, mean 19.39, 1.03-68.38; p=ns), and vs cohort 1 (p=ns). The only patient in cohort 2 with NHL showed serum TSLP of 160.91 pg/mL, comparable to the mean TSLP in the 12 UD pSS-NHL (151.96 pg/mL). Importantly, in pSS-related NHL in stable remission, serum TSLP resulted undetectable (7/13) or detectable at very low levels (6/13) (mean 10.46, 0-38.5), and significantly lower than in benign pSS patients from the two cohorts (n=203, mean 31.48, 0-140.8; p=0.0022). Metachronous samples from one patient, at the stage of NHL activity and then at NHL remission, showed a decrease in TSLP from 128.04 pg/mL to undetectable levels. Finally, TSLP levels were increased also in the Greek cohort (mean 54.9, 26.72-78.95), and significantly higher than the two Italian cohorts (p=0.0085 and p<0.0001, vs cohort 1 and 2, respectively).

Conclusion:

Serum TSLP levels are increased in pSS, as herein confirmed in independent cohorts. TSLP might be important in the disease pathophysiology and mirrors the course of pSS-related B-cell lymphoproliferation itself. It may thus represent a novel important biomarker.

References:

[1]Gandolfo S. et al, Clin Exp Rheumatol. 2019 May-Jun;37 Suppl 118(3):55-64.

Disclosure of Interests:

Saviana Gandolfo: None declared, Cinzia Fabro: None declared, Serena Colafrancesco: None declared, Francesco Carubbi Speakers bureau: Francesco Carubbi received speaker honoraria from Abbvie and Celgene outside this work., Francesco Ferro: None declared, Elena Bartoloni Bocci: None declared, Efstathia Kapsogeorgou: None declared, Andreas Goules: None declared, Luca Quartuccio Consultant of: Abbvie, Bristol, Speakers bureau: Abbvie, Pfizer, Roberta Priori: None declared, Alessia Alunno: None declared, Guido Valesini: None declared, Roberto Giacomelli Grant/research support from: Actelion, Pfizer, Speakers bureau: Abbvie, Roche, Actelion, BMS, MSD, Ely Lilly, SOBI, Pfizer, Roberto Gerli: None declared, Chiara Baldini: None declared, Athanasios Tzioufas: None declared, Salvatore De Vita Consultant of: Roche, Human Genome Science, Glaxo Smith Kline and Novartis

Rumen Inoculum Collected from Cows at Slaughter or from a Continuous Fermenter and Preserved in Warm, Refrigerated, Chilled or Freeze-Dried Environments for In Vitro Tests

The utilization of animal donors of rumen fluid for laboratory experiments can raise ethical concerns, and alternatives to the collection of rumen fluids from live animals are urgently requested. The aim of this study was to compare the fresh rumen fluid (collected at slaughter, W) with that obtained from a continuous fermenter (RCF) and three methods of rumen fluid preservation (refrigeration, R, chilling, C, and freeze-drying, FD). The fermentability of different inoculum was evaluated by three in vitro tests (neutral detergent fiber (NDF) and crude protein (CP) degradability and gas production, NDFd, RDP and GP, respectively) using six feeds as substrates. Despite the two types of inoculum differed in terms of metabolites and microbiota concentration, the differences in vitro fermentability between the two liquids were less pronounced than expected (-15 and 20% for NDFd and GP when the liquid of fermenter was used and no differences for RDP). Within each in vitro test, the data obtained from rumen and from fermenter liquids were highly correlated for the six feeds, as well as between W and R (r: 0.837-0.985; p < 0.01). The low fermentative capacity was found for C and, particularly, FD for liquids. RCF could be used to generate inoculum for in vitro purposes and short-term refrigeration is a valuable practice to manage inoculum.

Effect of dietary nitrogen level and source on mRNA expression of urea transporters in the rumen epithelium of fattening bulls

This paper aims to study the effect of the dietary treatments on mRNA expression of urea transporter B (UT-B) and some aquaporins (AQP) in rumen epithelium of Italian Simmental young bulls. Eighty animals allocated to 16 pens were fed from about 500 to 650 kg body weight with four experimental diets, which resulted from the combination of two crude protein levels (125 and 110 g/kg dry matter, diets M and L, respectively) and two nitrogen sources (soybean meal (SBM) or SBM partly replaced by an isonitrogenous mixture of corn and urea; diets -U and +U, respectively). At slaughtering samples of blood and rumen epithelium were collected from six bulls for each diet. Blood samples were analysed for haematological parameters and quantitative PCR was carried out on the mRNA extracted from the rumen epithelium samples. The bulls fed diets M had lower plasma concentrations of aspartate aminotransferase than those receiving diets L (78.9 vs. 88.3 U/l, p = 0.04). Plasma urea was higher (p = 0.03) for diets M and lower for diets +U (2.0 vs. 2.5 and 1.73 vs. 2.00 mmol/l, respectively, in M and L diets, p = 0.04). The effect of dietary treatments on rumen UT expression were limited to AQP3, which was down regulated (p = 0.01) in diets +U. Finally, a high positive correlation (R2 = 0.871) between the expressions of AQP7 and AQP10 was found. In conclusion, the AQP3 appears very responsive to dietary treatments and therefore it is a candidate to be further studied in rumen metabolism experiments. The close relationship between mRNA expression of AQP7 and AQP10 indicates a similar function of these two proteins.

The -308 TNFα and the -174 IL-6 promoter polymorphisms associate with effective anti-TNFα treatment in seronegative spondyloarthritis

The genetic predisposition to a long-term efficacy of anti-tumor necrosis factor (TNF)α treatment in seronegative spondyloarthritis (SpA) was investigated by analysing the possible correlation between several single nucleotide gene polymorphisms and the retention rate of anti-TNFα therapies. We compared patients needing to switch the first anti-TNFα (Sw, No. 64) within at least 12 months of follow-up with patients not needing to switch (NSw, No. 123), observing at least 6 months of treatment to establish anti-TNFα failure, leading to treatment change. Response to treatment was evaluated by standardised criteria (BASDAI for axial involvement, DAS28-EULAR for peripheral involvement). The TNFα -308 A allele and the interleukin (IL)-6 -174GG homozygosis resulted as independent biomarkers predicting survival of the first anti-TNFα therapy in SpA patients (P=0.007, odds ratio (OR): 4.4, 95% confidence interval (CI)=1.5-13.1 and P=0.035, OR: 2.1, 95% CI=1.1-4.4). Also, the male gender (P=0.001, OR: 3.4, 95% CI=1.6-7.1) associated with the NSw phenotype, whereas no association was found either with the specific diagnosis or the predominant joint involvement.

Study on the possible role of the -174G>C IL-6 promoter polymorphism in predicting response to rituximab in rheumatoid arthritis

OBJECTIVE

Identification of genetic biomarkers of response to biologics in rheumatoid arthritis (RA) is a relevant issue. The -174G>C interleukin-6 (IL-6) promoter polymorphism was investigated in RA patients treated with rituximab (RTX), being IL-6 a key cytokine for B cell survival and proliferation, thus possibly implicated in rituximab efficacy.

METHODS

The study was conducted in a real-life retrospective cohort of 142 unselected RA patients (120F/22M) treated with RTX and referred to 7 rheumatologic centres in the north of Italy. One hundred and thirteen (79.6%) patients were rheumatoid factor (RF)-positive and 112 (78.9%) were anti-CCP antibodies positive. The response to therapy was evaluated at the end of the sixth month after the first RTX infusion, by using both the EULAR criteria (DAS28) and the ACR criteria. The IL-6 -174G>C promoter polymorphism was analyzed by RFLP following previously reported methods.

RESULTS

Lack of response to RTX at month +6 by EULAR criteria was more prevalent in RA patients with the IL-6 -174 CC genotypes (9/21, 42.8%), than in the GC/GG patients (23/121, 19.0%) (OR 3.196, 95% CI=1.204-8.485; p=0.0234). Similar results were found when evaluating the response by ACR criteria. No differences were found in RA duration, baseline DAS28, baseline HAQ, RF status, anti-CCP status according to the different IL-6 -174 genotypes.

CONCLUSION

IL-6 promoter genotyping may be useful to better plan treatment with RTX in RA. Larger replication studies are in course to confirm these preliminary results.

[Fibronectin gene polymorphisms and clinical manifestations of mixed cryoglobulinemic syndrome: increased risk of lymphoma associated to MspI DD and HaeIII AA genotypes]

OBJECTIVE

To analyse FN gene polymorphisms in type II mixed cryoglobulinemic syndrome (MCsn), an immune-complex mediated systemic vasculitis linked to hepatitis C virus (HCV) infection and characterized by rheumatoid factor (RF) positive B-cell proliferation at high risk for the progression into non Hogkin's lymphoma (NHL).

METHODS

Samples from eighty-one patients, with MCsn (type II serum cryoglobulins and clinical signs of vasculitis were studied. Sixty-five (65/81, 80.3%) patients were HCV-positive. Twenty-one (25.9%) patients had developed a B-cell NHL during the course of MCsn. Seventy-two patients with HCV-negative and MC-unrelated NHL and 110 healthy blood donors (HBDs) were taken as controls. HaeIIIb and MspI FN gene polymorphisms were analysed by ELISA, whenever possible.

RESULTS

HaeIIIb and MspI allele and genotypic frequencies did not differ between MCsn patients and HBDs. Of note, the DD-MspI allele and genotype frequencies did not differ between MCsn patients and HBDs. Of note, the DD-MspI (OR = 5.56; DI = 1.67-18.51, p = 0.0046) and the AA-HaeIIIb (OR = 5.54, CI = 1.64- 18.76, p = 0.0066) homozygosis appeared significantly and independently associated with the development of B-cell NHL in MCsn patients, with the HaeIIIbA allele possibly conferring an increased risk of NHL in the general population (OR = 1.72, CI = 1.128-2.635, p = 0.0133). In contrast, the major vasculitic manifestations, such as peripheral neuropathy, skin ulcers and glomerulonephritis tended to be associated with the counterpart MspI C allele. No association between FN plasma levels and FN genotypes was found.

CONCLUSION

Genotyping for MspI and HaeIIIb FN gene polymorphisms may be clinically relevant to define the predisposition to the major clinical manifestations in MCsn.

Characterization of pars intermedia connections in amphibians by biocytin tract tracing and immunofluorescence aided by confocal microscopy

Biocytin, recently introduced in neuroanatomical studies, was used as a retrograde tract tracer in combination with immunofluorescence in order to analyse the neurochemical characters of some central neuronal projections to the pars intermedia in two amphibian species, the anuran Rana esculenta and the urodele Triturus carnifex. After biocytin insertions in the pars intermedia, neurons became retrogradely labelled in the suprachiasmatic hypothalamus and the locus coeruleus of the brainstem in both species. Some scattered biocytin-labelled neurons were observed in the preoptic area. Moreover, working on the same sections, immunofluorescence revealed a number of codistributions and, in some cases, colocalization in the same neurons of biocytin labellings and immunopositivity for (1) tyrosine hydroxylase in the suprachiasmatic hypothalamus and the locus coeruleus of Rana and Triturus, (2) gamma-aminobutyric acid in the suprachiasmatic hypothalamus of Rana and Triturus and (3) neuropeptide Y in the suprachiasmatic hypothalamus of Rana. The specificity of such colocalizations was fully confirmed using dual-channel confocal laser scanning microscopy analysis.