[15th Post-ECTRIMS Meeting: a review of the latest developments presented at the 2022 ECTRIMS Congress (Part II)]. / XV Reunión Post-ECTRIMS: revisión de las novedades presentadas en el Congreso ECTRIMS 2022 (II).

INTRODUCTION: On 4 and 5 November 2022, Madrid hosted the 15th edition of the Post-ECTRIMS Meeting, where neurologists specialised in multiple sclerosis outlined the latest developments presented at the 2022 ECTRIMS Congress, held in Amsterdam from 26 to 28 October. AIM: To synthesise the content presented at the 15th edition of the Post-ECTRIMS Meeting, in an article broken down into two parts. DEVELOPMENT: This second part describes the new developments in terms of therapeutic strategies for escalation and de-escalation of disease-modifying therapies (DMT), when and in whom to initiate or switch to highly effective DMT, the definition of therapeutic failure, the possibility of treating radiologically isolated syndrome and the future of personalised treatment and precision medicine. It also considers the efficacy and safety of autologous haematopoietic stem cell transplantation, different approaches in clinical trial design and outcome measures to assess DMT in progressive stages, challenges in the diagnosis and treatment of cognitive impairment, and treatment in special situations (pregnancy, comorbidity and the elderly). In addition, results from some of the latest studies with oral cladribine and evobrutinib presented at ECTRIMS 2022 are shown.

TITLE: XV Reunión Post-ECTRIMS: revisión de las novedades presentadas en el Congreso ECTRIMS 2022 (II).Introducción. El 4 y el 5 de noviembre se celebró en Madrid la Reunión Post-ECTRIMS, en la que neurólogos expertos en esclerosis múltiple resumieron las principales novedades presentadas en el congreso de ECTRIMS 2022, celebrado entre el 26 y el 28 de octubre en Ámsterdam. Objetivo. Sintetizar las ponencias que tuvieron lugar en la Reunión Post-ECTRIMS, en un artículo desglosado en dos partes. Desarrollo. En esta segunda parte, se presentan las novedades sobre las estrategias terapéuticas de escalado y desescalado de los tratamientos modificadores de la enfermedad (TME), cuándo y a quién iniciar o cambiar a TME de alta eficacia, la definición de fracaso terapéutico, la posibilidad de tratar el síndrome radiológico asilado, el futuro del tratamiento personalizado y la medicina de precisión, la eficacia y seguridad del autotrasplante de células madre hematopoyéticas, diferentes aproximaciones en el diseño de ensayos clínicos y en las medidas de resultados para evaluar TME en fases progresivas, retos en el diagnóstico y tratamiento del deterioro cognitivo, y tratamiento en situaciones especiales (embarazo, comorbilidad y personas mayores). Además, se muestran los resultados de algunos de los últimos estudios realizados con cladribina oral y evobrutinib presentados en el ECTRIMS 2022.

The protective effect of extra-virgin olive oil in the experimental model of multiple sclerosis in the rat.

This study has evaluated the effect of EVOO (Extra-Virgin olive oil), OA (oleic acid) and HT (hydroxytyrosol) in an induced model of MS through experimental autoimmune encephalomyelitis (EAE).Dark Agouti 2-month old rats (25 males) were divided into five groups: (i) control group, (ii) EAE group, (iii) EAE+EVOO, (iv) EAE+HT, and (v) EAE+OA. At 65 days, the animals were sacrificed and the glutathione redox system and bacterial lipopolysaccharide (LPS) and LPS-binding protein (LBP) products of the microbiota in brain, spinal cord, and blood were evaluated.Gastric administration of EVOO, OA, and HT reduced the degree of lipid and protein oxidation, and increased glutathione peroxidase, making it a diet-based mechanism for enhancing protection against oxidative damage. In addition, it reduced the levels of LPS and LBP, which appeared as being increased in the EAE correlated with the oxidative stress produced by the disease.

Dose-dependent S-allyl cysteine ameliorates multiple sclerosis disease-related pathology by reducing oxidative stress and biomarkers of dysbiosis in experimental autoimmune encephalomyelitis.

Garlic is a component of the Mediterranean diet. S-allyl cysteine (SAC), the most common organosulphur present in garlic, possesses neuroprotective properties. This investigation was performed to evaluate the dose-dependent protective action of SAC on oxidative damage, inflammation and gut microbiota alterations biomarkers. Experimental autoimmune encephalomyelitis (EAE) as a model of multiple sclerosis (MS) was induced by the myelin oligodendrocyte glycoprotein (MOG), whose effects were quantified by examining the changes in: clinical score, lipid peroxidation products, carbonylated proteins, glutathione system, tumor necrosis factor alpha (TNFα), and lipopolysaccharide membrane bacteria (LPS). Our results reveal that MOG induces paralysis, oxidative damage and increases in LPS binding protein (LBP) and LPS levels. In this work, two doses of SAC were compared with two dose of N-acetyl cysteine (NAC). SAC was more effective than NAC and it prevented the harmful effects induced by MOG more effectively at the dose of 50mg/kg than that of 18mg/kg. Surprisingly, NAC increases LBP levels while SAC had not such negative effect. In conclusion the data show the ability of SAC to modify EAE evolution.

Comparison of different treatments for oestrous induction in seasonally anovulatory mares.

The aim of this study was to evaluate the effects of different treatments for induction and synchronization of oestrus and ovulation in seasonally anovulatory mares. Fifteen mares formed the control group (C), while 26 mares were randomly assigned to three treatment groups. Group T1 (n = 11) were treated with oral altrenogest (0.044 mg/kg; Regumate(®) ) during 11 days. Group T2 (n = 7) was intravaginally treated with 1.38 g of progesterone (CIDR(®) ) for 11 days. In group T3 (n = 8), mares were also treated with CIDR(®) , but only for 8 days. All mares received PGF2α 1 day after finishing the treatment. Sonographic evaluation of follicles, pre-ovulatory follicle size and ovulation time was recorded. Progesterone and leptin levels were analysed. Results show that pre-ovulatory follicles were developed after the treatment in 88.5% of mares. However, the pre-ovulatory follicle growth was dispersal, and sometimes it was detected when treatment was not finished. While in mares treated with intravaginal device, the follicle was soon detected (1.5 ± 1.2 days and 2.3 ± 2.0 days in T2 and T3 groups, respectively), in T1 group, the pre-ovulatory follicle was detected slightly later (3.9 ± 1.6 days). The interval from the end of treatment to ovulation did not show significant differences between groups (T1 = 13.1 ± 2.5 days; T2 = 11.0 ± 3.6 days; T3 = 13.8 ± 4.3 days). The pregnancy rate was 47.4%, similar to the rate observed in group C (46.7%; p > 0.05). Initial leptin concentrations were significantly higher in mares, which restart their ovarian activity after treatments, suggesting a role in the reproduction mechanisms in mares. It could be concluded that the used treatments may be effective for oestrous induction in mares during the late phase of the seasonally anovulatory period. Furthermore, they cannot synchronize oestrus, and then, it is necessary to know the reproductive status of mares when these treatments are used for oestrous synchronization.

Neuroprotective effects of extremely low-frequency electromagnetic fields on a Huntington's disease rat model: effects on neurotrophic factors and neuronal density.

There is evidence to suggest that the neuroprotective effect of exposure of extremely low-frequency electromagnetic fields (ELF-EMF) may be due, at least in part, to the effect of these fields on neurotrophic factors levels and cell survival, leading to an improvement in behavior. This study was undertaken to investigate the neuroprotective effects of ELFEF in a rat model of 3-nitropropionic acid (3NP)-induced Huntington's disease. Behavior patterns were evaluated, and changes in neurotrophic factor, cell damage, and oxidative stress biomarker levels were monitored in Wistar rats. Rats were given 3NP over four consecutive days (20 mg/kg body weight), whereas ELFEF (60 Hz and 0.7 mT) was applied over 21 days, starting after the last injection of 3NP. Rats treated with 3NP exhibited significantly different behavior in the open field test (OFT) and the forced swim test (FST), and displayed significant differences in neurotrophic factor levels and oxidative stress biomarkers levels, together with a neuronal damage and diminished neuronal density, with respect neuronal controls. ELFEF improved neurological scores, enhanced neurotrophic factor levels, and reduced both oxidative damage and neuronal loss in 3NP-treated rats. ELFEF alleviates 3NP-induced brain injury and prevents loss of neurons in rat striatum, thus showing considerable potential as a therapeutic tool.

Effects of anabolic implants of oestradiol alone or in combination with trenbolone acetate on the ultrastructure of mammary glands in female lambs regarding their interference in prolactin secretion.

The side-effects of anabolic steroid implants on mammary gland ultrastructure were evaluated in female lambs treated with oestradiol (n = 10) and with oestradiol plus trenbolone acetate (n = 10). Ten non-implanted lambs were used as controls. Apart from the ultrastructural study of the mammary gland, an assessment of the prolactin pituitary cell population was carried out by immunological methods. Our results showed that oestrogenic implants exert stimulating effects on mammary gland development, both by activating the synthesis process at mammary gland cell levels and by increasing prolactin pituitary production. Nevertheless, there was no evidence of secretory products in the lumen of the gland. Implants containing trenbolone acetate counteracted the mammary stimulus of oestrogens showing ultrastructural images of cell autolysis and necrosis.

Enzyme-histochemical profiles of fiber types in mature canine appendicular muscles.

The histochemical characteristics of skeletal muscle were assessed using a range of samples from 7 appendicular muscles taken from adult mixed-breed dogs (1.5 to 3 years of age). Two slow-twitch fiber subtypes (IA and IB) and three II subtypes (IIA, IIB and IIC) were identified according to myofibrillar myosin adenosine triphosphatase reaction after acid and alkaline preincubation. Type IIB fibers were not found in all muscles, and were only biologically significant in m. semitendinosus. The metabolic potential of these fibers is fairly similar to that of IIA fibers, but significantly different to that of IIB fibers in other mammals, suggesting that they may be designed to play a different functional role during locomotion. All canine muscle fibers have moderate to high oxidative capacity, which may be related to the extraordinary athletic capability of the species.

Muscle fiber type composition and fiber size in successfully and unsuccessfully endurance-raced horses.

Triplicate biopsies from three different depths of the gluteus medius muscle were obtained in 36 endurance-raced horses, aged 8.42 +/- 2.85 yr. Twenty of the horses were considered excellent endurance performers according to the mean speed of their three fastest records in endurance events for the past 2 or 3 years, whereas 16 were moderate performers, with a mean racing speed < 12.5 km/h (in 120- to 180-km endurance rides), < 14 km/h (in 80- to 120-km endurance rides), or < 13.5 km/h (in 40- to 60-km endurance rides). Significant differences in muscle fiber type composition and fiber size were recorded; excellent performers had a higher percentage and a larger size of type I and type IIa fibers (high and low myosin adenosinetriphosphatase activity at pH 4.5, respectively) and a lower percentage of type IIb fibers (moderate myosin adenosinetriphosphatase activity at pH 4.5), including both type IIb oxidative (moderate to high NADH-tetrazolium reductase activity) and IIb nonoxidative (low NADH-tetrazolium reductase activity). The differences in distribution of myofiber types and in fiber sizes were more marked in the deeper parts compared with the superficial regions of muscle. Our results also imply a greater homogeneity among the fiber type sizes across the muscle in horses with a superior endurance performance than in horses that had been poorly or moderately endurance raced. Thus the results show that fiber type proportions and fiber size in equine skeletal muscle are directly related to the athletic ability of the horse for endurance events.

Intramuscular distribution of fibre types in the gluteus medius of the horse: a histochemical analysis.

The results from a recent study by Bruce and Schurg (1990) indicate that the gluteus medius (Gm) of the horse is a complex muscle subdivided by an internal tendinous sheet into two regions (dorsal and ventral) which may subserve different functions. In the present study, both regions were found to contain a similar proportion of histochemically-determined muscle fibre types. Fibre type composition did not generally vary over the length of the muscle at the same relative depth. In contrast, there was a significant tendency for the percentage of type I fibres to increase gradually in accordance with depth. These histochemical results do not suggest that the two regions of the Gm assume distinct functional roles; they do, however, indicate that at a given relative depth the muscle fibre type distribution is relatively uniform over the length of the muscle. Nevertheless, care should be exercised in sampling and interpreting data obtained from limited biopsy of equine Gm, due to the substantial histochemical variation of fibre type composition as a function of sampling depth.

Skeletal muscle histochemistry in male and female Andalusian and Arabian horses of different ages.

Muscle biopsies were taken from the middle gluteal muscle of 143 untrained horses (83 Andalusians [AN] and 60 Arabians [AR]) ranging from 10 days to 24 years old. The horses were separated according to breed and sex and allotted to five age groups: A, 0 to three months; B, yearlings; C, two to three years; D, five to 10 years; and E, 11 to 24 years. There was an increase in the percentage of type I fibres (about 100 per cent) as well as a decrease in the percentage of type IIB fibres (AN, 50 per cent; AR, 40 per cent) over the five age groups. The percentage of type IIA fibres rose significantly over the first two or three age groups. The overall decrease in the subgroup IIB fibres with age was proportionally greater for IIB oxidative fibres (AN, 72 per cent; AR, 68 per cent) than for IIB non-oxidative fibres (AN, 5 per cent; AR, 34 per cent). The mean cross-sectional area of all three fibre types increased significantly with age. In any given age group, the mean relative cross-sectional area occupied by IIA fibres in the biopsy specimens was significantly greater in stallions than in mares, at the expense of IIB fibres.

Skeletal muscle fiber size in untrained and endurance-trained horses.

The mean area and minimal diameter of 3 histochemically determined myofiber types (1, 2A, and 2B; myosin ATPase in acid buffer) were calculated in middle gluteal muscle biopsy specimens from 62 stallions, 47 Andalusians and 15 Arabians, ranging in age from 6 to 12 years. Fourteen Andalusians and 7 Arabians were untrained, and the remainder were actively endurance-trained. The 6-month training schedules involved walking, slow trotting, and cantering. Fourteen Andalusians were moderately endurance-trained, whereas the other 19 Andalusians and 8 Arabians were strongly endurance-trained. Significant differences were not recorded between untrained and endurance-trained Arabians with respect to the area (type 1, 3,194 +/- 869 microns 2 and 3,150 +/- 370 microns 2; type 2A, 3,819 +/- 890 microns 2 and 3,380 +/- 356 microns 2; and type 2B, 4,872 +/- 962 microns 2 and 4,417 +/- 646 microns 2) or minimal diameter (type 1, 52.2 +/- 7.4 microns and 52.8 +/- 3.1 microns; type 2A, 58.1 +/- 6.7 microns and 55.0 +/- 2.8 microns; and type 2B, 65.3 +/- 6.4 microns and 63.4 +/- 4.3 microns) of the 3 fiber types, nor between untrained and endurance-trained Andalusians with respect to the area (untrained, 3,990 +/- 690 microns 2; moderately endurance-trained, 3,882 +/- 347 microns 2; and strongly endurance-trained, 3,758 +/- 510 microns 2) and minimal diameter (untrained, 58.1 +/- 4.7 microns; moderately endurance-trained, 59.7 +/- 2.7 microns; and strongly endurance-trained, 58.7 +/- 4.5 microns) of 2A fibers.(ABSTRACT TRUNCATED AT 250 WORDS)

Influence of age on fibre type characteristics in the middle gluteal muscle of Andalusian foals.

34 Andalusian foals of both sexes were divided into three age-groups (A = mean age 1 month, B = 7 months, C = 14 months). Samples of the right m. gluteus medius were stained for m-ATPase and NADH-TR in order to determine fibre type composition and size as well as the relative area occupied by each type. Results revealed no statistically significant variation in the proportion of type I fibre among the three age-groups. Significant differences were recorded, however, for type II fibres; an increase in the proportion of IIA fibres was accompanied by a decrease in IIB ones, the difference being most marked between groups A and B. IIB high-oxidative fibres also decreased, while IIB low-oxidative ones showed no significant variation. All fibre types increased significantly in size; types I and IIA recorded a threefold increase, whereas type IIB showed least growth. The relative area occupied by each type increased significantly between groups A and B, but only IIA fibres recorded a significant increase in relative area between groups B and C.

Muscle fibre type composition in untrained and endurance-trained Andalusian and Arab horses.

Muscle biopsies were taken from the middle gluteal muscle of 68 stallions (52 Andalusian [AN] and 16 Arab [AR]) ranging from six to 12 years of age. Seventeen AN horses and eight AR horses were untrained, while the remainder underwent active endurance training for 6 months. Fifteen AN horses were moderately endurance-trained while the other 20 AN horses and eight AR horses were strongly endurance-trained. Percentages of type I and type II fibres were similar in all groups (P greater than 0.05). The group of horses with the hardest training had a higher percentage of type IIA fibres (AN P less than 0.01; AR P less than 0.02) and a lower percentage of type IIB fibres (P less than 0.05 for AN and AR) than the untrained horses. All trained horses had a higher percentage of type IIB oxidative fibres and a lower percentage of type IIB non-oxidative fibres than the untrained horses (P less than 0.01 for both). These results suggest that the proportions of type I and type II fibres are highly stable within a given breed, but the stimulus of training facilitates changes both in contractile properties and, particularly, in the oxidative capacity of type II subgroups.

Variations in fibre composition of the gastrocnemius muscle in rats subjected to speed training.

Thirty-six adult Wistar rats were divided into three groups. One group was used as a control, and the other two underwent different training programmes in which greater relevance was attached to the intensity of exercise than to its duration. Samples of the red and mixed portions of m. gastrocnemius (caput lateralis) were stained with m-ATPase to determine the percentage of type I, IIA and IIB fibres, and with NADH-TR in order to quantify variations in the percentage of low staining intensity (FG) fibres. The most notable results obtained were: a) the ratio of type I type II fibres remained unchanged; b) the proportion of IIA fibres increased, while that of IIB fibres decreased correspondingly; c) FG fibres, which were virtually absent from the red portion, recorded a clear decrease which was more marked, and occurred more rapidly, than in IIB fibres. These differences were all statistically significant in the mixed portion of the muscle. Adaptive changes in fibre composition in the red portion were less marked.

Type IIC fibres in certain muscles of the adult rat (sedentary and exercised).

Samples were taken, at fixed levels, of the vastus lateralis, the caput lateralis of the gastrocnemius muscle and the longissimus lumbaris of 72 Wistar rats which were either sedentary or subjected to various exercise schedules. The samples were analyzed using the histochemical technique of myosin ATPase (m-ATPase) after preincubation at pH 4.2, and the fibre-types I, II (IIA and IIB) and IIC were identified, calculating the percentage of type IIC fibres as well as their minimum diameter. The percentages of these IIC fibres found in the red and mixed parts of the gastrocnemius (caput lateralis) and the longissimus lumbaris were between 0.7% and 2.6%. However, their presence was not detected in the vastus lateralis or in the white part of the gastrocnemius (caput lateralis). The lack of differences in this fibre type between the males and females of the population was shown statistically. Likewise, no significant modification of the IIC fibres between sedentary and exercised animals was seen. With regard to fibrillar size, females showed a smaller minimum diameter than males, the results showing a small increase in the size of these fibres in both sexes after exercise, although in most cases this was not statistically significant.

Degree of correspondence between contractile and oxidative capacities in horse muscle fibres: a histochemical study.

Samples taken from the middle gluteal muscle of 95 untrained adult horses of different ages and sex were subjected to histochemical analysis using the myosin adenosine triphosphatase (m-ATPase) and nicotinamide adenine dinucleotide tetrazolium reductase (NADH-TR) staining techniques. Fibres were classified into types I, IIA and IIB according to m-ATPase activity after preincubation at pH 4.4. The percentage of FT (Fast-Twitch Glycolytic) fibres and the proportion of IIB fibres with "high" and "low" oxidative capacity were determined in serial sections stained for NADH-TR. Statistical analysis revealed a significantly higher proportion of IIB fibres than FT fibres (P less than 0.001), though both percentages were correlated. Thus, 72.2 +/- 17.6% of type IIB fibres showed low oxidative capacity, but the remaining 27.8 +/- 17.6% showed high aerobic potential, and thus did not correspond to FT fibres. These results confirm that the contractile capacity of a muscle fibre does not determine its oxidative profile. The different types of muscle fibre should thus be classified solely according to m-ATPase activity, since this characteristic is related to the molecular structure of contractile proteins. Oxidative capacity should be assessed separately, and not be used as a criterion for fibre classification in horses.