A metabolomics perspective on 2 years of high-intensity training in horses

The plasma metabolomic profile of elite harness horses subjected to different training programmes was explored. All horses had the same training programme from 1.5 until 2 years of age and then high-intensity training was introduced, with horses divided into high and low training groups. Morning blood samples were collected at 1.5, 2, 2.5 and 3.5 years of age. The plasma was analysed using targeted absolute quantitative analysis and a combination of tandem mass spectrometry, flow-injection analysis and liquid chromatography. Differences between the two training groups were observed at 2 years of age, when 161 metabolites and sums and ratios were lower (e.g. ceramide and several triglycerides) and 51 were higher (e.g. aconitic acid, anserine, sum of PUFA cholesteryl esters and solely ketogenic AAs) in High compared with low horses. The metabolites aconitic acid, anserine, leucine, HArg synthesis and sum of solely ketogenic AAs increased over time, while beta alanine synthesis, ceramides and indole decreased. Therefore high-intensity training promoted adaptations linked to aerobic energy production and amino acid metabolism, and potentially also affected pH-buffering and vascular and insulin responses.

Validation of a novel smartphone-based photoplethysmographic method for ambulatory heart rhythm diagnostics

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Vinnova - The Swedish Agency for Innovation Systems.

Region Stockholm Innovation Fund.

Introduction

Devices for long-term and ambulatory recording of heart rhythm have limited availability within health care systems worldwide, potentially leading to missed diagnoses and limitations in peri-procedural heart rhythm management. As smartphones are becoming ubiquitous the availability of heart rhythm diagnostics and management of atrial fibrillation (AF) using smartphone photoplethysmography (PPG) compared to electrocardiography (ECG) is increasing. Previous validation studies of smartphone-PPG applications have all been performed under supervision in healthcare settings. In addition, no previous study has validated smartphone-PPG compared to simultaneous ECG recordings, with manual heart rhythm interpretation of the PPG recordings nor have they included patients with atrial flutter (AFL).

Purpose

The aim of this study was to validate a novel smartphone-PPG method for heart rhythm diagnostics in patients with AF and/or AFL when in use unsupervised in an ambulatory setting.

Methods

Unselected patients undergoing direct current cardioversion at a University Hospital for treatment of AF or AFL were asked to perform one-minute heart rhythm recordings post-treatment at least twice daily for 30 days in their home environment. All included were provided with an unmodified iPhone 7 smartphone running the CORAI Heart Monitor PPG application simultaneously with a single-lead ECG recording (KardiaMobile). PPG and ECG recordings were interpreted independently by two readers.

Results

In total 280 patients, with median age of 69.0 years (31% women) were included from November 2018 to July 2020 and registered 18 005 simultaneous PPG and ECG recordings. Of the PPG recordings 96.9% had sufficient quality for diagnosis compared to 95.1% of the ECG recordings (p < 0.001). Precardioversion ECG recordings were interpreted as AF in 82.1%, AFL in 14.3% and as having insufficient quality for diagnosis in 3.6% of the patients. After removal of recordings with insufficient quality 69.7% of ECG recordings were interpreted as sinus rhythm, 28.2% as AF and 2.1 % as AFL. Manual interpretation of the PPG recordings diagnosed AF/AFL (sensitivity) in 97.7% and sinus rhythm (specificity) in 99.4% of the recordings compared to manually interpreted ECG recordings, with an overall accuracy of 98.9%. Results excluding recordings interpreted as AFL on ECG or PPG diagnosed AF (sensitivity) in 99.0% and sinus rhythm (specificity) in 99.7% of the recordings, with an overall accuracy of 99.5%.

Conclusion

A novel smartphone-PPG method can be used by patients unsupervised in their home environment for accurate heart rhythm diagnostics of AF and AFL with high sensitivity and specificity.

Reduced high-intensity training distance in growing horses had no effect on IGF-1 concentrations, but training onset interrupted time-dependent IGF-1 decline

This study investigated plasma insulin like growth factor (IGF)-1 concentrations in 16 young Standardbred horses introduced to systematic high-intensity training at two different levels of intensity. Growth and locomotion asymmetry and correlations between these and plasma IGF-1 concentrations were also examined. From September as 1-year olds to March as 2-year olds (Period 1), all horses were subjected to the same submaximal training program. In March (start of Period 2), the horses were divided into two groups (n=8) and one group was introduced to regular high-intensity training. The other group was introduced to a program where the high-intensity exercise distances were reduced by 30%. These two training programs were maintained for the remaining 21 months of the study (Periods 2, 3, and 4). There was no effect of training group on plasma IGF-1 concentrations. A continuous decline in IGF-1 levels was observed throughout the study (P<0.0001), with one notable interruption in Period 2 when the IGF-1 concentration remained at the level seen at the start of Period 1. Growth rate of body length was equally high in Periods 1 and 2 (P>0.05). Front and hind limb asymmetry was elevated in Period 2 compared with Period 1. There were positive correlations between IGF-1 concentrations and changes in body condition score, and a negative correlation between IGF-1 concentration and weight. These results indicate that introduction to high-intensity training induces IGF-1 release in horses, but that a 30% difference in the distances used in high-intensity training does not affect IGF-1 levels. The temporary interruption in decline in IGF-1 release with the onset of high-intensity training may influence growth pattern and locomotion asymmetry, but further studies are needed to assess causality.

Locomotion asymmetry in young Standardbred trotters in training and links to future racing career

This study evaluated whether front and hind limb symmetry patterns observed from 1.5 through 3 years of age in Standardbred trotters in training affect racing activity at older age. The hypothesis tested was that asymmetries observed during this period are linked to reduced number of lifetime races and low earnings. Sixteen Standardbreds were subjected to a controlled training and dietary programme from the age of 1.5 years until December as 3-year-olds (P1) and then continued their career with other trainers. On 17 occasions during P1, locomotion asymmetry (vector sum) in front and hind limbs during trot in hand was recorded with a sensor-based system. By 10 years of age, data on lifetime number of races and earnings of the horses were obtained from the Swedish Trotting Association. Horses were divided in groups based on the number of lifetime races performed, i.e. more or less than the median of the cohort born the same year. Mean asymmetry levels did not differ between horses performing more or less lifetime races than the cohort median. However, horses that showed the poorest lifetime race activity showed elevated hind limb asymmetry in August at the age of 3 years, compared to horses with more races (group <median: 9±6 mm vs group >median: 6±2 mm (P=0.02)). There were no correlations between individual mean and peak asymmetries and lifetime earnings. It is concluded that locomotion symmetry observed during trot in hand at the age of 1.5-year-olds to December as 3-year-olds was not a simple and straight-forward predictor of future racing career. However, hind limb asymmetries of around 10 mm in the late season as 3-year-olds could be a warning of impaired future performance.

Effects of horse housing on musculoskeletal system post-exercise recovery

This study examined the effects of two housing systems (control housing and loose housing) on musculoskeletal condition during recovery from race-like exercise in Standardbred horses. The hypothesis was that a loose housing system provides better conditions for musculoskeletal recovery than the control housing. Eight adult geldings (mean age 11 years) were used in a study with a cross-over design, with the control housing (CH) and loose housing (LH) treatments each run for 21 days. The horses had ad libitum access to forage and performed two similar race-like exercise tests (ET), on day 7 and day 14 in each treatment. Blood samples were collected before ET, at finish line, and at 7, 22, and 44 h of recovery and analysed for the muscle enzyme activities of creatine kinase and amino transferase. Before and three days after ET, hind leg fetlock joint region circumference and diameter, joint range of motion in right hock and carpus, mechanical nociceptive threshold in back muscle, and movement asymmetry were recorded. Overall circumference and overall diameter of hind fetlock joint region were lower in LH horses than CH horses (P=0.045 and P=0.017, respectively), but no other differences were observed. In conclusion, a loose housing system did not alter the recovery of musculoskeletal condition other than preventing a post exercise enlargement of the circumference and diameter of the hind fetlock joint region.

Speed of gaits in Icelandic horses and relationships to sex, age, conformation measurements and subjective judges’ scores

The aim was to measure the mean and maximum speed and the range of speed in all gaits of Icelandic horses shown at a breed evaluation field test (BEFT). In addition, the effect of speed on scores for the gaits and whether speed was affected by age, sex and conformation measurements were investigated. The study was carried out in Iceland on 266 horses (180 mares and 86 stallions). Horse speed and distance ridden were recorded by global positioning system during the riding assessment in BEFT. Conformation measurements and scores for each gait were obtained from the official studbook Worldfengur. The range of speed in walk, slow tölt, tölt, trot, pace, canter and gallop was, respectively, 1.5-2.2, 3.2-5.5, 4.6-10.6, 4.5-8.6, 7.1-11.9, 5.8-9.8 and 7.9-13.5 m/s (n=149-248). Scores for all gaits were affected by speed of the gait, with speed explaining most variance in scores for pace (53%) and least in scores for slow tölt and walk (2 and 3%, respectively). Stallions were faster than mares in tölt, trot, pace and canter (P<0.05). Horses aged ≥7 years and 6-year-olds were faster in pace and canter than 4-year-olds (P<0.05). Horse conformation measurements most affected speed in pace and walk, which were elevated with increased height at withers, height at croup, body length and length of front legs (P<0.05). In conclusion, objective measurements of speed in the gaits of Icelandic horses shown in a BEFT were documented for the first time. The information can be used to formulate requirements for gaits in BEFT and in competition manuals. Objective measurements of speed should be used in future assessments of gaits in Icelandic horses in BEFT, and thus improve standardisation and genetic evaluation of breeding horses.

FRI0457 LONG-TERM OUTCOMES AND TREATMENT EFFICACY IN PATIENTS WITH TNF RECEPTOR-ASSOCIATED AUTOINFLAMMATORY SYNDROME (TRAPS) FROM THE EUROFEVER INTERNATIONAL REGISTRY

Background:

Tumour necrosis factor (TNF) receptor-associated periodic syndrome (TRAPS) is one of the best-known monogenic auto-inflammatory disorders resulting from an autosomal dominant variation in the TNF super family receptor 1A (TNFRSF1A) gene (1).

Objectives:

To define best treatment approach in patients with TRAPS and effect on long-term outcomes.

Methods:

We reviewed all data on patients with TRAPS enrolled in the Eurofever international registry according the INSAID gene variant classification and the new Eurofever/PRINTO classification criteria (EPCC).

Results:

Data on 226 patients were available. Patients not fulfilling the EPCC carrying likely benign/benign variants (21 patients, 9%) or VOUS/not classified variants (40 patients, 18%) displayed a milder disease than the patients fulfilling the EPCC with VOUS/not classified variants (38 patients, 17%) or pathogenic/likely pathogenic variants (127 patients, 56%). In particular, in patients not fulfilling the EPCC, less frequent abdominal pain and skin rashes, higher efficacy rate of colchicine and no development of AA amyloidosis have been reported. Almost 90% of patients fulfilling the EPCC required maintenance therapy and anti-interleukin (IL)-1 drugs were the most frequently used, with the highest efficacy rate (>85% complete response), while Etanercept was less effectively used and discontinued in 65% of patients.

Conclusion:

Anti-IL-1 drugs are the best maintenance treatment in TRAPS with potential to reverse the most serious disease complications of AA amyloidosis and infertility. The diagnosis of TRAPS should be considered very carefully in patients carrying VOUS/not classified variants not fulfilling the EPCC.

References:

[1]Lachmann HJ, Papa R, Gerhold K, Obici L, Touitou I, Cantarini L, et al. The phenotype of TNF receptor-associated autoinflammatory syndrome (TRAPS) at presentation: a series of 158 cases from the Eurofever/EUROTRAPS international registry. Annals of the rheumatic diseases 2014;73:2160-7.

Acknowledgments:

RP would like to thank the European Federation of Immunology (EFIS) for the short-term bursary and HL for her continuous support and guidance during the fellowship at the National Amyloidosis Centre in London.

Disclosure of Interests:

Riccardo Papa: None declared, Thirusha Lane: None declared, Francesca Bovis: None declared, Kirsten Minden Consultant of: GlaxoSmithKline, Sanofi, Speakers bureau: Roche, Isabelle Touitou: None declared, Luca Cantarini: None declared, Marco Cattalini: None declared, Laura Obici: None declared, Annette Jansson: None declared, Alexander Belot: None declared, Beata Woska-Kuśnierz: None declared, Rainer Berendes: None declared, Agustin Remesal: None declared, Marija Jelusic: None declared, Graciela Espada: None declared, Irina Nikishina: None declared, Esther Hoppenreijs: None declared, Maria Cristina Maggio: None declared, Taryn Youngstein: None declared, Tamer Rezk: None declared, Charalampia Papadopoulou: None declared, Paul Brogan Grant/research support from: Roche, Novartis, SOBI, Chemocentryx, Novimmune, Consultant of: Roche, SOBI, UCB, Novartis, Speakers bureau: Roche, SOBI, UCB, Novartis, Philip N Hawkins: None declared, Patricia Woo: None declared, Nicolino Ruperto Grant/research support from: Bristol-Myers Squibb, Eli Lily, F Hoffmann-La Roche, GlaxoSmithKline, Janssen, Novartis, Pfizer, Sobi (paid to institution), Consultant of: Ablynx, AbbVie, AstraZeneca-Medimmune, Biogen, Boehringer Ingelheim, Bristol-Myers Squibb, Eli Lily, EMD Serono, GlaxoSmithKline, Hoffmann-La Roche, Janssen, Merck, Novartis, Pfizer, R-Pharma, Sanofi, Servier, Sinergie, Sobi, Takeda, Speakers bureau: Ablynx, AbbVie, AstraZeneca-Medimmune, Biogen, Boehringer Ingelheim, Bristol-Myers Squibb, Eli Lily, EMD Serono, GlaxoSmithKline, Hoffmann-La Roche, Janssen, Merck, Novartis, Pfizer, R-Pharma, Sanofi, Servier, Sinergie, Sobi, Takeda, Marco Gattorno Consultant of: Sobi, Novartis, Speakers bureau: Sobi, Novartis, Helen J. Lachmann: None declared

Effect of circadian rhythm, age, training and acute lameness on serum concentrations of cartilage oligomeric matrix protein (COMP) neo-epitope in horses

Background

Molecular serum markers that can identify early reversible osteoarthritis (OA) in horses are lacking.

Objectives

We studied serum concentrations of a novel cartilage oligomeric matrix protein (COMP) neo‐epitope in horses subjected to short‐term exercise and with acute lameness. The effects of circadian rhythm and age were also evaluated.

Study design

Longitudinal studies in healthy horses and cross‐sectional comparison of lame and non‐lame horses.

Methods

Sera were collected from five horses before and after short‐term interval exercise and during full‐day box rest. Sera from 32 acutely lame horses were used to evaluate age‐related effects. Independent samples from control horses (n = 41) and horses with acute lameness (n = 71) were included. COMP neo‐epitope concentrations were analysed using custom‐developed inhibition ELISAs validated for equine serum. The presence of COMP neo‐epitope was delineated in healthy and osteoarthritic articular cartilage with immunohistochemistry.

Results

COMP neo‐epitope concentrations decreased after speed training but returned to baseline levels post‐exercise. No correlations between age and serum COMP neo‐epitope concentrations were found (r = 0.0013). The mean (±s.d.) serum concentration of COMP neo‐epitope in independent samples from non‐lame horses was 0.84 ± 0.38 μg/mL, and for lame horses was 5.24 ± 1.83 μg/mL (P<0.001). Antibodies against COMP neo‐epitope did not stain normal articular cartilage, but intracytoplasmic staining was found in superficial chondrocytes of mild OA cartilage and in the extracellular matrix of moderately osteoarthritic cartilage.

Main limitations

ELISA was based on polyclonal antisera rather than a monoclonal antibody. There is a sex and breed bias within the groups of horses, also it could have been of value to include horses with septic arthritis and tendonitis and investigated joint differences.

Conclusions

This COMP neo‐epitope can be measured in sera, and results indicate that it could be a biomarker for pathologic fragmentation of cartilage in connection with acute joint lameness.

Novel foods: a risk profile for the house cricket (Acheta domesticus)

Novel foods could represent a sustainable alternative to traditional farming and conventional foodstuffs. Starting in 2018, Regulation (EU) 2283/2015 entered into force, laying down provisions for the approval of novel foods in Europe, including insects. This Approved Regulation establishes the requirements that enable Food Business Operators to bring new foods into the EU market, while ensuring high levels of food safety for European consumers. The present risk profile tackles the hazards for one of the most promising novel food insects, the house cricket (Acheta domesticus). The risk profile envisages a closed A. domesticus crickets rearing system, under Hazard Analysis and Critical Control Points (HACCP) and good farming practices (GFP), in contrast with open cricket farms. The methodology used involves screening the literature and identifying possible hazards, followed by adding relevant inclusion criteria for the evidence obtained. These criteria include animal health and food safety aspects, for the entire lifespan of crickets, based on the farm to fork One Health principle. When data were scarce, comparative evidence from close relatives of the Orthoptera genus was used (e.g. grasshoppers, locusts and other cricket species). Nevertheless, significant data gaps in animal health and food safety are present. Even if HACCP‐type systems are implemented, the risk profile identifies the following considerable concerns: (1) high total aerobic bacterial counts; (2) survival of spore‐forming bacteria following thermal processing; (3) allergenicity of insects and insect‐derived products; and (4) the bioaccumulation of heavy metals (e.g. cadmium). Other hazards like parasites, fungi, viruses, prions, antimicrobial resistance and toxins are ranked as low risk. For some hazards, a need for additional evidence is highlighted.

Road transport and diet affect metabolic response to exercise in horses

This study investigated the effects of transport and diet on metabolic response during a subsequent race-like test in Standardbred horses in training fed a forage-only diet and a 50:50 forage:oats diet. Six trained and raced Standardbred trotter mares were used. Two diets, 1 forage-only diet (FONLY) and 1 diet with 50% of DM intake from forage and 50% from oats (FOATS), were fed for two 29-d periods in a crossover design. At Day 21, the horses were subjected to transport for 100 km before and after they performed an exercise test (transport test [TT]). At Day 26, the horses performed a control test (CT), in which they were kept in their stall before and after the exercise test. Blood samples were collected throughout the study, and heart rate and water intake were recorded. Heart rate and plasma cortisol, glucose, and NEFA concentrations were greater for the TT than for the CT (P = 0.008, P = 0.020, P = 0.010, and P = 0.0002, respectively) but were not affected by diet. Plasma acetate concentration was lower during the TT than during the CT (P = 0.034) and greater for the FONLY than for the FOATS (P = 0.003). There were no overall effects of the TT compared with the CT on total plasma protein concentration (TPP), but TPP was lower with the FONLY than with the FOATS (P = 0.016). There was no overall effect of the TT compared with the CT on water intake, but water intake was greater with the FONLY than the FOATS (P = 0.011). There were no overall effects of transport or diet on BW, plasma lactate, or plasma urea concentration. It was concluded that both transport and diet affect metabolic response during exercise in horses. Aerobic energy supply was most likely elevated by transportation and by the FONLY. The FONLY also decreased exercise-induced effects on extracellular fluid regulation. These results highlight the importance of experimental design in nutrition studies. If the aim is to examine how a diet affects exercise response in competition horses, transport should preferably be included in the experimental design, because horses are likely to be transported before a competition.

Physiological response to an experimental 100 m flying pace race in Icelandic horses and effect of rider

This study evaluated the physiological response to an experimental 100 m flying pace race (EPR) in Icelandic horses with pace-competition experience, and whether there was an effect of rider. A cross-over design with nine horses and two riders was used. The EPR was performed twice (once with each rider) with four days of rest in-between. The EPR consisted of two runs (I and II), of which at least 100 m was in pace at full speed according to international competition rules. Plasma lactate concentration increased and was greater after pace run II than I (18.5±1.3 vs 11.9±0.7 mmol/l; P<0.001). Heart rate was higher during pace run I than II (207±3 vs 205±3; P=0.02). Heart rate and Lact had not recovered 30 min post exercise but Hct was back to resting level after 30 min recovery. Speed did not differ between riders and pace runs (pooled mean ± standard deviation of pace runs: 10.4±0.7 m/s, range 9.2-12.1 m/s) but HR and Lact were higher from warm-up and until 30 min recovery with rider 1 than 2 (P<0.001). There was a negative correlation between post EPR Lact with rider 1 and previous best record (r2=0.72, P=0.032). To conclude, a 100 m flying pace race in the Icelandic horse is a high-intensity exercise and anaerobic metabolism is crucial for performance. The rider had an effect on the physiological response but it is unclear if it was due to body weight, riding style or both. The practical relevance of the differences observed between riders remains to be proven but our results indicate that they may have limited impact on single day competitions since the speed was the same with the two riders.

Reduced training distance and a forage-only diet did not limit race participation in young Standardbred horses

In this study, a survey was used to document the type and amount of training to which 2- to 3-year old Swedish Standardbred horses are generally subjected. Moreover, an experimental study was conducted to examine the ability to achieve conventional performance goals in 16 Standardbred geldings fed a forage-only diet and allocated to either a control training programme (C-group) or a training programme with the high intensity training distance reduced by 30% (R-group) from March as 2-year-olds until December as 3-year-olds. The median distance of high intensity training per week reported by professional trainers was 6,700 m. In experimental horses, planned high intensity training/week was 6,315 and 4,288 m in C-group and R-group, respectively. There was no difference between experimental training groups in ability to race. The proportion of experimental horses that passed a preparation race as 2-year-olds (100%) and qualified for races (94%) was greater (P<0.05) than for the rest of the cohort (77 and 63%), geldings of the same cohort (71 and 45%) and siblings of the experimental horses (84 and 69%). The proportion of horses that raced (56%) was equal to that of the cohort and of siblings (54%), but greater than the proportion of cohort geldings (35%, P<0.05). In experimental horses, total earnings until 7 years of age were correlated to exercise haematocrit as 3-year-olds (r=0.51, P>0.05) and number of races (r=0.55, P>0.05). Race record was correlated to VLa4 as 3-year-olds (r=-0.75, P<0.01). It was concluded that a forage-only diet and shorter distance of high intensity training than commonly used in Standardbred training in Sweden do not appear to restrict ability to qualify for races and race before 4 years of age.

Drones may be used to save lives in out of hospital cardiac arrest due to drowning

BACKGROUND

Drowning leading to out-of-hospital cardiac arrest (OHCA) and death is a major public health concern. Submersion with duration of less than 10min is associated with favorable neurological outcome and nearby bystanders play a considerable role in rescue and resuscitation. Drones can provide a visual overview of an accident scene, their potential as lifesaving tools in drowning has not been evaluated.

AIM

The aim of this simulation study was to evaluate the efficiency of a drone for providing earlier location of a submerged possible drowning victim in comparison with standard procedure.

METHOD

This randomized simulation study used a submerged manikin placed in a shallow (<2m) 100×100-m area at Tylösand beach, Sweden. A search party of 14 surf-lifeguards (control) was compared to a drone transmitting video to a tablet (intervention). Time from start to contact with the manikin was the primary endpoint.

RESULTS

Twenty searches were performed in total, 10 for each group. The median time from start to contact with the manikin was 4:34min (IQR 2:56-7:48) for the search party (control) and 0:47min (IQR 0:38-0:58) for the drone-system (intervention) respectively (p<0.001). The median time saved by using the drone was 3:38min (IQR 2:02-6:38).

CONCLUSION

A drone transmitting live video to a tablet is feasible, time saving in comparison to traditional search parties and may be used for providing earlier location of submerged victims at a beach. Drone search can possibly contribute to earlier onset of CPR in drowning victims.

Elispot assay detection of cytokine secretion in multiple sclerosis patients treated with interferon-b1a or glatiramer acetate compared with untreated patients

The mechanisms behind the beneficial effects of interferon-b1a (IFN-b1a) and glatiramer acetate (GA) in the treatment of multiple sclerosis (MS) are still uncertain. A ltered cytokine patterns have been suggested including inhibition of proinflammatory cytokines like interferon-g (IFN-g) and enhancement of anti-inflammato ry cytokines such as interleukin-4 (IL-4). Twenty-nine patients with MS (10 untreated, nine treated with IFN-b1a and 10 with GA) were investigated with elispot of peripheral blood mononuclear cells. Spontaneous and myelin induced (myelin basic protein (MBP), myelin oligodendro cyte glycoprotein (MO G)-14-39 and MO G 63-87) IFN-g, IL-4, IL-5 and IL-10 secretion was studied. We found a significant reduction of spontaneous IFN-g, IL-4 and IL-5, but no difference in IL-10 secreting cells in both groups of treated patients compared with the untreated patients. Myelin-specific responses showed a significant decrease of IFN-g and an increase of IL-5, but no change in IL-4 and IL-10 secreting cells in treated compared with untreated patients. Both treatment groups revealed similar cytokine secretion patterns except for a more pronounced decrease of both spontaneous and MO G 14-39 induced IL-4 secretion in the IFN-b1a treated group. Thus, immunological effects of IFN-b1a and G A were similar showing that disease promoting Th1 (IFN-g) cells were reduced while the potentially beneficial Th2 response (IL-4) was maintained.

A comparison of the physiological response to tölt and trot in the Icelandic horse

This study compared the effect of ridden tölt and trot at 3 speeds on physiological responses in trained adult (15.3 ± 1.6 yr) Icelandic horses. The experiment had a crossover design with 8 horses, 2 treatments (incremental exercise test in tölt and trot), and 2 riders. Each horse performed 2 tests per day (1 gait with 2 riders, minimum 4.5 h between) on 2 separate days, with 1 d of rest in between. The exercise test consisted of three 642-m phases at 3.0 m/s (Speed), 4.0 m/s (Speed), and 5.0 m/s (Speed) and was performed outdoors on a 300-m oval gravel riding track in northern Iceland in May 2012. Heart rate (HR) was measured during warm-up, the exercise test, and after 5, 15, and 30 min of recovery. Blood samples were taken at rest, after warm-up, after each phase of the exercise test, and after 5, 15, and 30 min of recovery. Respiratory rate was counted for at least 15 s at rest, at the end of the exercise test, and at the end of the 30-min recovery, and rectal temperature was measured on these occasions. There were no differences in HR between tölt and trot at any time point ( > 0.05). At Speed, hematocrit and plasma lactate concentration were greater ( < 0.05) in tölt (40% ± 1%, 1.1 ± 0.06 mmol/L) than in trot (39% ± 1%; 0.9 ± 0.06 mmol/L). There was a prolonged recovery of hematocrit and respiratory rate, a slower decrease in rectal temperature, and a tendency of a prolonged recovery of plasma lactate concentration ( = 0.0675) after tölt. In conclusion, there were only minor differences in physiological responses to tölt and trot in this selected group of experienced adult Icelandic horses and the biological and practical significance of the slightly elevated physiological responses to tölt and the slower recovery remains to be determined.

Fate of necrotic volume after microwave ablation of multiple liver metastases

BACKGROUND/AIMS

The aim of this study was to find the rate of shrinkage of necrosis and time of peak ablation volume after multiple microwave ablations in the treatment of multiple liver metastases of colorectal cancer. These factors are not known and are important in evaluation of treatment and identification of local recurrence, as microwave treatment is becoming more used thanks to improved technology in diagnostics and interventional therapy.

METHODOLOGY

A retrospective analysis of non-cirrhotic patients with multiple liver only metastases of colorectal cancer, not suited for resection for this reason. Patients were selected for palliative microwave treatment at a liver multidisciplinary team conference. 68 ablations were made in six patients. Ablation volume was analysed with repeated imaging and computer analyses.

RESULTS

The ablation volume peeks after 5-7 days where after reduction of the necrosis in the liver occurs logarithmically with a 60% reduction of ablation volume after 100 days and 80% after a year.

DISCUSSION

Liver regeneration after microwave ablations occurs at a constant logarithmic rate after an initial expansion of the ablation volume during the first five days. Evaluation of ablation volume in comparison to tumour volume must take this into account so that follow-up imaging is properly timed.

Physiological response to a breed evaluation field test in Icelandic horses

This study examined the response in terms of heart rate (HR), respiratory rate (RR), haematocrit (Htc), rectal temperature (RT), and some plasma variables in Icelandic horses of different sexes and ages performing the riding assessment in a breed evaluation field test (BEFT). The study was conducted in Iceland on 266 horses (180 mares and 86 stallions, divided into four age groups; 4, 5, 6 and ≥7 years old). RT and RR were recorded and blood samples were taken before the warm-up and after the riding assessment. Horse HR, velocity and distance were recorded during the warm-up, the riding assessment and a 5-min recovery period. The distance covered in the BEFT was 2.9 ± 0.4 km (range: 1.8 to 3.8 km, n=248), the duration was 9:37 ± 1:22 min:s (range: 5:07 to 15:32 min:s, n=260) and the average speed was 17.8 ± 1.4 km/h (range: 13.2 to 21.3 km/h, n=248). Average HR was 184 ± 13 b.p.m. (range: 138 to 210 b.p.m., n=102) and peak HR 224 ± 9 b.p.m. (range: 195 to 238 b.p.m., n=102), and 36% of the BEFT was performed at HR ≥200 b.p.m. Post-exercise plasma lactate concentration (Lac) was 18.0 ± 6.5 mmol/l (range: 2.1 to 34.4 mmol/l, n=266), and there was an increase in total plasma protein, plasma creatine kinase and aspartate amino transferase concentration, as well as RR, RT and Htc. Stallions covered a longer total distance (in the warm-up and BEFT) (P<0.05), at a faster speed during BEFT (P<0.001) than mares and had higher Htc and lower HR and post-exercise Lac values. There were few effects of age, but the 4- and 5-year-old horses had lower Htc than older horses and 4-year-old horses had higher post-exercise RR than older horses, although they were ridden for a shorter distance, shorter duration and at lower peak velocity (P<0.1). The results showed that the riding assessment in the BEFT is a high-intensity exercise. The results also showed that aerobic fitness was higher in stallions and that age had a limited effect on the physiological response. It is suggested that these results should be used as a guide for the development of training programmes and fitness tests in Icelandic horses that would improve both performance and welfare of the horse.

A survey of training regimes used by top trainers of the Icelandic pace racing horse

The aim of this study was to document training strategies used by experienced trainers of the Icelandic pace racing horse. Data were obtained using a questionnaire, to which responses were received from nine trainers on the world ranking list in 250 m pace races and with a minimum of 12 years of experience of pace training. Training was commenced at an age of 5.4±1.0 years and the average time to achieve competitive condition was estimated to be 1.9±0.8 years. Horses were trained almost every day and the trainers described a variety of training methods. Interval training appeared to be common, while training at pace was performed less than twice per week. Mental aspects seemed to be a challenge for performance.

The phenotype of TNF receptor-associated autoinflammatory syndrome (TRAPS) at presentation: a series of 158 cases from the Eurofever/EUROTRAPS international registry

OBJECTIVE

To evaluate the genetic findings, demographic features and clinical presentation of tumour necrosis factor receptor-associated autoinflammatory syndrome (TRAPS) in patients from the Eurofever/EUROTRAPS international registry.

METHODS

A web-based registry collected retrospective data on patients with TNFRSF1A sequence variants and inflammatory symptoms. Participating hospitals included paediatric rheumatology centres and adult centres with a specific interest in autoinflammatory diseases. Cases were independently validated by experts in the disease.

RESULTS

Complete information on 158 validated patients was available. The most common TNFRSF1A variant was R92Q (34% of cases), followed by T50M (10%). Cysteine residues were disrupted in 27% of cases, accounting for 39% of sequence variants. A family history was present in 19% of patients with R92Q and 64% of those with other variants. The median age at which symptoms began was 4.3 years but 9.1% of patients presented after 30 years of age. Attacks were recurrent in 88% and the commonest features associated with the pathogenic variants were fever (88%), limb pain (85%), abdominal pain (74%), rash (63%) and eye manifestations (45%). Disease associated with R92Q presented slightly later at a median of 5.7 years with significantly less rash or eye signs and more headaches. Children were more likely than adults to present with lymphadenopathy, periorbital oedema and abdominal pains. AA amyloidosis has developed in 16 (10%) patients at a median age of 43 years.

CONCLUSIONS

In this, the largest reported case series to date, the genetic heterogeneity of TRAPS is accompanied by a variable phenotype at presentation. Patients had a median 70 symptomatic days a year, with fever, limb and abdominal pain and rash the commonest symptoms. Overall, there is little evidence of a significant effect of age or genotype on disease features at presentation.

Phosphorus balance and fecal losses in growing Standardbred horses in training fed forage-only diets

This study examined the P balance and fecal P losses in growing Standardbred horses in training fed a forage-only diet with or without P supplementation and assessed the magnitude and proportion of the soluble, inorganic P (Pi) fraction in feces. Fourteen Standardbred horses (aged 20.0 ± 0.3 mo) adapted to ad libitum intake of grass forage containing 0.25% P were used in a crossover experiment investigating 2 dietary treatments with (high-P) and without (low-P) mineral supplementation for 6 d. Daily feed intake and refusals were weighed. Spot samples of feces were collected twice daily on d 4 to 6 and analyzed for total P and Pi. Acid-insoluble ash was used as a marker for total fecal output. Spot samples of urine were collected once on d 4 to 6 and analyzed for P and creatinine. Daily P intake was greater (P < 0.001) for the high-P diet (32.0 ± 0.6 g) than the low-P diet (17.5 ± 0.6 g), and the individual intake ranged from 13.3 to 38.4 g/d. Total fecal excretion of P was also greater (P < 0.001) for the high-P diet (30.3 ± 0.8 g/d) than the low-P diet (17.0 ± 0.8 g/d) whereas excretion in urine was less than 0.2 g/d on both diets. Using simple regression analysis, fecal endogenous P losses were estimated to be less than 10 mg/kg BW. Phosphorus retention was 1.6 ± 0.6 and 0.3 ± 0.6 g/d on the high- and low-P diets, respectively, but only that for the high-P diet was greater (P < 0.05) than 0 g/d. The proportion of Pi of total fecal P excretion was 100 ± 3% for the high-P diet and 87 ± 3% for the low-P diet (P = 0.005) and Pi increased linearly with P intake (y = 1.10x - 4.44; r(2) = 0.91; CV = 9.9%; P < 0.001). In conclusion, on this forage-only diet significant retention of P occurred at a daily P intake of 7.1 g/100 kg BW. Phosphorus was mainly excreted in feces and both total fecal P and Pi excretion had a strong relationship to P intake. More than 80% of total P appeared to be soluble. Fecal endogenous P losses were similar to those described previously in growing horses.

Insulin response to feeding forage with varying crude protein and amino acid content in horses at rest and after exercise

This study assessed the insulin response to forage intake with varying crude protein (CP) content in horses at rest and after exercise. Six geldings were fed three grass haylage-only diets for 7 days according to a 3×3 Latin square design. On day 7, blood samples were collected before and for 120 min after feeding 15% of the daily allowance before exercise (feeding A) and after standardised exercise (feeding B). Feed samples were collected before each feeding. Dry matter (DM) and nutrient content varied (DM: 37-58%, water-soluble carbohydrates minus fructans (WSC-f): 3-12% of DM, CP: 10-15% of DM) which resulted in a variation in nutrient intake within haylage batches. Based on individual CP and WSC-f intakes, intake groups were therefore formed (low and high CP intake; ≤ and ≯180 g CP/100 kg body weight, respectively and low and high WSC-f intake; ≤ and ≯100 g/100 kg body weight, respectively). Amino acids were analysed and intakes were generally higher in the high CP group than in the low CP group. An ANOVA model including horse, CP group and WSC-f intake explained 95% of the variation in plasma insulin response compared to 87% using a model including horse and WSC-f group alone. The plasma insulin area under curve (AUC) following feeding A tended to be higher in the high CP group than in the low CP group (P=0.08), but there was no difference after feeding B. Plasma glucose AUC was not affected by CP group (P≯0.05). The study indicates that the post-prandial plasma insulin response in horses fed a forage-only diet is increased by high WSC-f intake but may also be increased by high CP intake, at least at rest. However, due to the low number of observations further studies are needed.

A bibliometric review on nutrition of the exercising horse from 1970 to 2010

The main aims of the present review are to provide a bibliometric analysis of the research published on the nutrition of the exercising horse from 1970 to 2010 and to determine whether this research has had any practical impact on feeding practices. In addition, we evaluated whether some of the key nutritional questions posed at the beginning of the 1980s have in fact been answered. Less than 300 publications were published in the period 1970-1980, but a large increase in the number of publications was observed between the period 1981-1990 and the period 1991-2000. Most papers were published in the Equine Veterinary Journal and American researchers, universities or institutes were particularly productive. The majority of the publications were in the areas of fluid balance, fat and glucose metabolism. Using information from field studies, there appears to have been a trend for a reduction in the amount of starch rich concentrates fed to performance horses from 1979 to 2007 and an increase in the use of oil supplementation. Whilst there have been several significant advances in our scientific knowledge of nutritional practices over the past few decades that have become routine practice in the field, others have not cascaded down. Unfortunately, we have not really fully answered any of the questions posed in the early 1980s and whilst it is possible that such questions can never be fully answered, there is also a concern that lack of sufficient funding, especially for the fundamental pieces of information needed to underpin our nutrition advice, will hamper progress in the future.

Expression patterns of 17β-hydroxysteroid dehydrogenase 14 in human tissues

17βHSD enzymes catalyze the stereospecific oxidation/reduction at carbon 17β of androgens and estrogens, and are important players in intracrine sex hormone synthesis. The biological relevance of 17βHSD14, first named retSDR3, is largely unknown. We generated and validated an antibody targeting the 17βHSD14 antigen and used this for immunohistochemical evaluation of expression patterns in 33 healthy human tissues. Furthermore, sex steroid conversional activity in HSD17B14 overexpressing HEK293 and MCF10A cells was investigated by assessing interconversion products of estrone, estradiol, androstenedione, testosterone, and dehydroepiandrosterone. Immunohistochemical staining patterns of 17βHSD14 with the enzyme being primarily expressed in glandular epithelial tissue reveal an enzyme with possible implications in the secretion or conversion of externally derived compounds. A role for 17βHSD14 in sex steroid metabolism is supported by the finding that 17HSD14 oxidizes both estradiol and testosterone into less bioactive steroid metabolites estrone and androstenedione, respectively.

A comparison of a portable blood lactate analyser and laboratory plasma analysis of blood samples from exercised horses

Quick, simple methods for blood lactate analysis could be helpful in evaluating xercise response in the field, but methods validated for analysis of blood collected after high intensity exercise in horses are scarce. The aim of the present study was to compare the results obtained using a commercial, portable blood lactate analyser with those from laboratory plasma analysis of blood samples from horses performing intensive exercise. Venous blood samples were collected from 220 horses within 5 min of performing exercise at a mean peak heart rate of 222 ±9 beats/min. The samples were kept chilled and analysed using portable analyser within 10 min of collection. Samples were also centrifuged and the plasma frozen (-20 °C) until analysed using an enzymatic and spectrophotometric laboratory lactate analysis. There was a significant (P<0.05) correlation (R=0.94) between the methods at portable analyser values <12.0 mmol/l, but at higher values there was no correlation. There was a significant effect of method (P<0.0001) and portable analyser values were 21% lower than plasma lactate concentrations in the range 2.0-12.0 mmol/l. It is concluded that the portable analysis correlated well to a laboratory plasma analysis at portable analyser values <12.0 mmol/l and that the portable analyser appears to be a safe method for lactate analysis during training conditions, when very high lactate concentrations are not expected. However, users should be aware that the results underestimate the corresponding plasma values by approximately 20%.

Effects of crude protein intake from forage-only diets on muscle amino acids and glycogen levels in horses in training

REASONS FOR PERFORMING STUDY

There is little information about the influence of crude protein (CP) intake on glycogen and free pool amino acid concentrations in the muscle of horses in training. High energy forage-only diets may be an alternative to concentrate rich diets and may provide high levels of CP.

OBJECTIVE

To study the effect of feeding 2 forage-only diets, containing either high or moderate CP concentrations on glycogen and free pool amino acid concentrations in the muscle.

MATERIALS AND METHODS

Two high energy forage-only diets based on high-energy grass forage were fed for 23 days in a crossover design to 6 Standardbred horses in racing condition. One forage diet provided a high (HP) CP (16.6%) intake and the other diet provided recommended intake (RP) of CP (12.5%). At Day 19 a standardised treadmill test was performed to mimic a race. Blood samples were taken before, during and after (up to 90 min) the treadmill test and muscle biopsies (m. gluteus) were taken before and after exercise and after 90 min. Amino acids were analysed with a HPLC-technique and glycogen with a fluorimetric method.

RESULTS

A main effect of the HP diet was that muscle glycogen and leucine concentrations were higher compared to the RP diet. Branched chain amino acid concentrations in plasma remained higher during early recovery from exercise on the HP diet compared to the RP diet. Intense exercise caused a similar decrease in glycogen, aspartate and glutamate concentrations in muscle and increase in alanine concentration on both diets.

CONCLUSION

Feeding a forage-only diet with a high CP intake increases glycogen and leucine concentrations in muscle of horses in training. This may be beneficial for muscle recovery following intensive exercise.

Plasma aldosterone concentration and cardiovascular response to low sodium intake in horses in training

REASON FOR PERFORMING THE STUDY

Horses in training lose large amounts of sodium but little is known about the cardiovascular response to low sodium intake.

OBJECTIVES

To investigate the effect of low sodium intake on plasma aldosterone (pAldo) concentrations and the cardiovascular system of athletic horses, and to identify markers of low sodium intake.

METHODS

Seven Standardbred geldings in training (trained twice a week) were randomly offered a standardised diet supplemented (NaS, 58 mg Na/kg bwt) and not supplemented (NaN, 3 mg Na/kg bwt) with NaCl for 5 weeks in a changeover design. Blood samples were taken once a week and in Week 5, before and following an exercise test until 22.30 h and analysed for blood sodium (bNa), total plasma protein (TPP), pAldo, troponin I and packed cell volume (PCV). Blood pressure (BP) was measured and pulse wave recorded at rest with high definition oscillometric-technique (HDO). ECG and echocardiography were recorded. Water intake was measured before and on the day of exercise and voluntary saline intake was measured for 2 days after each period. Faecal samples were taken weekly and analysed for sodium and potassium content.

RESULTS

The pAldo and the PCV was higher in NaN compared to NaS. There were no differences between diets in BP, ECG, plasma troponin I and echocardiogram but HDO pulse amplitude tended to be smaller on diet NaN. Water intake was lower on diet NaN and saline intake higher. The response to exercise in bNa, pAldo, PCV and TPP was different on the 2 diets. Faecal potassium/sodium ratio was higher on NaN than on NaS.

CONCLUSION

This study shows that 5 weeks of low sodium intake increased plasma aldosterone concentration and PCV but no alterations in heart function was observed. Faecal potassium/sodium ratio could be used to assess sodium status in horses.

Comparison of grass haylage digestibility and metabolic plasma profile in Icelandic and Standardbred horses

The aim of the present study was to compare digestibility and metabolic response in Icelandic and Standardbred horses fed two grass haylages harvested at different stages of maturity. Six horses of each breed were used in a 24-day change-over design. A total collection of faeces was made on days 15-17 and 22-24. Blood samples were collected on day 24 of each period and analysed for total plasma protein (TPP), plasma urea, non-esterified fatty acids, cortisol and insulin concentration. There were no differences in digestibility coefficients of crude protein, neutral detergent fibre or energy between breeds but organic matter digestibility was higher in the Standardbred horses. On both haylages, the Icelandic horses gained weight whereas the Standardbred horses lost weight. The Icelandic horses had higher TPP, plasma insulin and lower plasma urea concentrations. Our results indicate that the Icelandic horse may be more prone to maintain positive energy balance in relation to the Standardbred horse, but there were no indication of a better digestive capacity in the Icelandic horses.

The physiological responses to simulated race tests on a track and on a treadmill in Standardbred trotters

REASON FOR PERFORMING STUDY

It is unclear to what extent the physiological response to a standardised treadmill exercise test simulating racing conditions resembles the circulatory and metabolic response observed after a simulated race on a track.

OBJECTIVES

To compare the physiological responses of a standardised treadmill exercise test used to simulate racing conditions and a simulated race performed on a track on the same Standardbred trotting horses, all in racing condition.

METHODS

Six Standardbred trotters in racing condition performed a standardised inclined treadmill exercise test protocol simulating racing conditions (ST) and a simulated race on a field track (FT). Heart and respiratory rates, haemoglobin, packed cell volume (PCV), glucose, pH, total carbon dioxide and potassium in venous blood and plasma lactate and total plasma protein were measured before and immediately after exercise and during recovery.

RESULTS

No differences were observed in heart rate, haemoglobin, PCV, total plasma protein, glucose concentrations after exercise and during recovery between the tests. Plasma lactate was higher and total carbon dioxide concentrations and pH were lower in blood at the end of exercise in the FT compared to the ST. Plasma lactate concentrations were still higher 30 min post exercise in the FT compared to the ST. Blood pH returned to resting values at 15 min of recovery for the ST and at 60 min of recovery for the FT. At 60 min of recovery total carbon dioxide concentrations had still not returned to resting values in any of the tests. Respiratory rate at the end of exercise and body temperature at 15 min of recovery was higher after the ST than the FT. Exercise caused an increase in blood potassium concentrations at the end of exercise in both tests, but concentrations were lower after the FT compared to the ST.

CONCLUSIONS

The haemodynamic response to the ST test at the end of exercise and during recovery, assessed from heart rate, Hb, and PCV, was similar to the response observed in the FT test. The differences observed in plasma lactate, blood pH and TCO2 concentrations between the ST and FT show that anaerobic metabolism was greater in the FT as this test included a finish at maximal speeds.

POTENTIAL RELEVANCE

The treadmill test used in this study to simulate a race resembles the haemodynamic response but not the anaerobic metabolic response observed after a simulated race on a track.

Effects on exercise response, fluid and acid-base balance of protein intake from forage-only diets in Standardbred horses

REASON FOR PERFORMING STUDY

High-energy forage might be an alternative to concentrates for performance horses and such forage can be produced by an early cut. However, early cut forage is high in crude protein (CP), which may result in an excessive CP intake.

OBJECTIVES

To investigate how CP intake affects nitrogen (N), fluid and acid-base balance, and exercise response in horses fed high-energy forage diets. The hypothesis was that high CP intake causes acidosis, and alters fluid balance and response to intensive exercise.

METHODS

Two forage-only diets based on high-energy grass forage were fed for 23 days in a crossover design to 6 Standardbred horses in racing condition. One forage diet provided a high (HP) CP (16.6%) intake and the other diet provided recommended intake (RP) of CP (12.5%) for racehorses. The horses had intensive exercise twice and slow exercise 1-3 times every week. At the beginning and end of each period, faeces and urine were collected for 48 and 72 h, respectively and analysed for dry matter, pH and N content. At Days 19 and 23 in each period 2 race-like exercise tests were performed, a standardised treadmill test and a field test on a race track. Blood samples were taken before, during and after the tests and analysed for sodium (Na), potassium (K), chloride (CI), total plasma proteins (TPP), TCO2, urea, pH and lactate. The strong ion difference (SID) was calculated and heart rate and respiratory rate was also recorded.

RESULTS

There was a decrease in urinary pH and an increase in N excretion, blood urea, water intake, urine volume and faecal water content on the HP diet. Total water intake was higher than the increase in urinary and faecal water loss indicating increased evaporative losses on the HP diet. During the exercise tests there were no significant differences between diets in TPP, plasma lactate, blood Na, K, Cl, TCO2, pH, SID and respiratory or heart rates.

CONCLUSION

Feeding a forage-only diet with a CP intake corresponding to 160% of the requirement caused an increase in N excretion within 36-48 h after the diet was introduced and alterations in fluid and acid base balance at rest.

POTENTIAL RELEVANCE

The increased urine and probably also evaporative fluid losses suggest that feeding a HP diet will cause an unnecessary challenge for horses during prolonged exercise.

Changes in faecal bacteria associated with concentrate and forage-only diets fed to horses in training

REASONS FOR PERFORMING STUDY

Diets rich in readily fermentable carbohydrates, fed traditionally to meet the increased energy requirements of the performance horse, are associated with a number of gastrointestinal disorders that involve disturbances in the intestinal microbiota, however, these changes are poorly understood.

OBJECTIVES

With the long-term objective of improving intestinal health and to increase understanding of the relationship between diet and microbiota, the effect of feeding Standardbred horses a high-energy forage-only (F) diet was studied compared to a more traditional forage-concentrate (C) diet on faecal microbiota.

METHODS

Diets were fed in a cross-over design to 6 mature geldings on a scheduled training regime, both periods consisting of 29 days. DNA was extracted from faecal samples collected at 4 time points from each period, bacterial 16S rRNA genes were amplified and community composition assessed by terminal-restriction fragment length polymorphism, cloning and sequencing. Faecal pH and cultivable lactic acid bacteria (LAB) and enterobacteria were also assessed on the final collection day of each period.

RESULTS

Diet F resulted in a microbial composition that was more stable between sampling periods and had lower counts (P < 0.05) of cultivable LAB and specifically members of the Streptococcus bovislequinus complex. Motile and swarming Lactobacillus ruminis was present in all horses on diet C and not in horses on diet F. Diet C also resulted in the increase (P < 0.05) in members of Clostridiaceae cluster III and a concomitant reduction (P < 0.05) in an unknown group of Bacteroidales.

CONCLUSIONS AND POTENTIAL RELEVANCE

The greater microbial stability and reduction in LAB and members of the Streptococcus bovis/equinus complex on diet F indicate an opportunity to develop feeding strategies that support equine health and welfare. Novel changes identified in the faecal microbiota that resulted from carbohydrate inclusion merit further investigation.

Significance of 17bHSD Type 14 as a Predictive Factor for Adjuvant Tamoxifen Treatment Response in Breast Cancer

Background: Peripheral sex steroid synthesis in target organs from adrenally derived steroid precursors is believed to be an ongoing event throughout life, but becomes exceedingly important as the gonadal sources of sex steroids cease, as is the case for estrogen synthesis in women after menopause. 17β hydroxysteroid dehydrogenases (17bHSDs) comprise a family of 14 enzymes catalyzing the stereospecific oxidation/reduction at position C17 of estrogens and androgens. Due to their importance in fine-tuning estrogen levels, the 17bHSDs have been studied in breast cancer. In a previous study examining mRNA of 17bHSD type 14, an enzyme driving the oxidation of estradiol into less potent estrone, from a cohort of stage 2 tumors, high levels were associated with longer disease-free survival. The present study was conducted in order to investigate whether this result could be repeated in another group of patients examining protein expression and to investigate whether 17bHSD type 14 has any prognostic or predictive importance in breast cancer patients systemically treated or untreated with tamoxifen. Material and Methods: A peptide sequence corresponding to amino acids 255 to 269 of human 17bHSD type 14 was synthesized and used for immunization of rabbits with the subsequent purification of a polyclonal antibody towards the antigen. A randomized tamoxifen trial comprising 1780 breast cancer patients was conducted in Stockholm, Sweden, 1976-1990. All patients had lymph node negative primary breast cancer and were postmenopausal at the time of diagnosis. We analyzed the protein expression of 17bHSD type 14 with immunohistochemistry using tissue microarrays, which were constructed from paraffin blocks originating from 912 patients. Results: Results were obtained from 847 patients. Among patients with estrogen receptor positive tumors, high expression of 17bHSD type 14 was associated with a significantly better benefit from tamoxifen as shown by a higher local recurrence-free probability (RR 0.38; 95% C.I. 0.19-0.77, p=0.006) when compared to patients bearing tumors with intermediate, low or negative expression levels (RR 1.20; 95% C.I. 0.54-2.60; p=0.67). The interaction test was significant (p=0.03). No significant difference in tamoxifen response was found when looking at 17bHSD type 14 in relation to breast cancer specific mortality. Furthermore, for untreated patients no prognostic significance for 17bHSD type 14 was found. Discussion: In the current study we show that intratumoral levels of 17bHSD type 14, an enzyme potentially involved in lowering the levels of potent estradiol, is a predictive factor in determining the local response to adjuvant tamoxifen treatment. The fact that patients with ER positive tumors have a greater possibility of responding well to tamoxifen when the expression levels of 17bHSD type 14 are high suggests that some patients would gain better from other treatments than tamoxifen, e.g. aromatase inhibitors and/or inhibitors of reducing 17bHSD enzymes.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2015.