Targeting the epigenome in malignant melanoma: Facts, challenges and therapeutic promises.

Malignant melanoma is the most lethal type of skin cancer with high rates of mortality. Although current treatment options provide a short-clinical benefit, acquired-drug resistance highlights the low 5-year survival rate among patients with advanced stage of the disease. In parallel, the involvement of an aberrant epigenetic landscape, (e.g., alterations in DNA methylation patterns, histone modifications marks and expression of non-coding RNAs), in addition to the genetic background, has been also associated with the onset and progression of melanoma. In this review article, we report on current therapeutic options in melanoma treatment with a focus on distinct epigenetic alterations and how their reversal, by specific drug compounds, can restore a normal phenotype. In particular, we concentrate on how single and/or combinatorial therapeutic approaches have utilized epigenetic drug compounds in being effective against malignant melanoma. Finally, the role of deregulated epigenetic mechanisms in promoting drug resistance to targeted therapies and immune checkpoint inhibitors is presented leading to the development of newly synthesized and/or improved drug compounds capable of targeting the epigenome of malignant melanoma.

Effects of dietary fibre on metabolism and performance in sows.

The etiology of Postpartum dysgalactia syndrome (PDS) includes stress οn preparturition and constipation associated with low water intake or low fiber intake. The aim of this study was to investigate the effects of a raw crude fibre concentrate (Arbocel®) on sow's metabolism and performance. 100 sows from a farm suffering from PDS, were divided into two groups, with equal distribu- tion of their parity (1 to 5 parity): a) T1 group (control group): 50 sows were fed with regular gestation feed (GF), pre-farrowing feed (PFF), and lactation feed (LF), b) T2 group: 50 sows were fed with regular GF, PFF and LF supplemented with topdress Arbocel® from 104th day of gestation until 7th day of lactation). Health parameters [faeces score (FS), PDS score (PDSS), body condition score (BCS)], performance parameters and liter characteristics were recorded. Blood samples were collected from 25 sows / group (5 sows per parity) 24 h after birth of last piglet and on 14th day of lactation for the evaluation of insulin, leptin and ghrelin levels in the serum, using commercial ELISA kits. In T2 group, BCS at farrowing (p⟨0.001), FS (p=0.001) and PDSS (p=0.003) were improved significantly. The number of piglets stillborn and dead due to crushing decreased (p=0.001), while the number of liveborn (p=0.016) and weaned piglets (p=0.001) increased in T2 group. Moreover, in T2 group, the BW of piglets at weaning was higher (p⟨0.001). A significant increase of insulin (p=0.032) and leptin (p=0.032) levels in serum was noticed in T2 group 24 h after farrowing. In conclusion, the supplementation of extra crude fibre in breeding stock with PDS problems due to nutritional imbalance has beneficial effects on their health and performance.

Evaluation of in-feed larch sawdust anti-inflammatory effect in sows.

The study aimed to investigate the possible anti-inflammatory activity of larch sawdust as feed supplement in lactating sows' diet and its possible effect on the prevalence of Postpartum Dysgalactia Syndrome under field conditions. In a Greek farrow-to-finish pig farm, fifteen sows were randomly and equally allocated to a negative control group (NC group), a positive control group (PC group), and a treatment group (LT group). The animals of the first two groups received 99% basic diet and 1% corn starch, while LT group animals received 99% basic diet and 1% larch sawdust. The whole trial period lasted 35 days (7 days prior to farrow - day of weaning). At parturition day, animals of the PC group received 2 ml of an anti-inflammatory drug intramuscularly (meloxicam, Metacam®, Boehringer Ingelheim Vetmedica), while the animals of both other groups, received 2 ml of normal saline. Results showed insignificant differences among experimental groups for parameters such as post-partum rectal temperature and piglets performance. On the contrary, a significant increase of mean milk lactation index was observed in LT and PC groups on the 4th day of lactation period, when compared with NC group (p=0.014). Additionally, mean IL-6 concentrations in blood in the LT group showed a tendency for reduction when compared with those found in NC, and insignificant difference (p>0.05) when compared with those observed in PC group 24 hours postpartum. Moreover, the respective TNFα mean level in the LT group at 24 and 72 hours after parturition was similar to that found in PC group, respectively) and significantly lower than that determined in the NC group (p=0.003, p=0.024. The results suggest a possible anti-inflammatory effect of larch sawdust in sows.

A feed additive containing Bacillus toyonensis (Toyocerin(®) ) protects against enteric pathogens in postweaning piglets.

AIMS: This study evaluated the efficacy of a probiotic containing Bacillus toyonensis spores (Toyocerin(®) ) in postweaning piglets against enteric pathogens. METHODS AND RESULTS: Seven hundred and ninety-two healthy weaning pigs of a commercial farrow-to-finish pig farm were used. The negative control group fed without Toyocerin(®) and two experimental groups fed similar to the negative control group, but supplemented with Toyocerin(®) at t 500 mg kg(-1) diet (Toyocerin 500 group) and 1000 mg kg(-1) diet (Toyocerin 1000 group), respectively. No significant difference (P > 0.05) in morbidity and mortality rate between groups was noticed. The Toyocerin groups showed higher body weight (P < 0.05) and lower feed conversion ratio compared to the negative control group. Diarrhoea score was less in both Toyocerin groups than negative control group (P < 0.05). Moreover, the use of Toyocerin(®) at 1000 mg kg(-1) diet resulted in higher average daily feed intake compared to other groups (P < 0.05), reduction of some enteric pathogens and increase of the number of lactic acid bacteria. CONCLUSIONS: The use of Toyocerin(®) in weaning pigs, especially at 1000 mg kg(-1) diet, improved their health and growth performance. SIGNIFICANCE AND IMPACT OF THE STUDY: This study shows that a feed additive containing B. toyonensis (Toyocerin(®) ) protects against enteric pathogens in postweaning piglets when fed this additive at a proper dose. The use of Toyocerin(®) at 1000 mg kg(-1) diet resulted in higher average daily feed intake, decrease of some enteric pathogens and higher number of lactic acid bacteria. The effect of the probiotic in other age groups remains to be established.

Effects of early vaccination with a gonadotropin releasing factor analog-diphtheria toxoid conjugate on boar taint and growth performance of male pigs.

The aim of this study was to evaluate safety (in terms of detecting possible adverse clinical effects attributable to vaccination), efficacy, and effects on growth performance of a gonadotropin releasing factor analog-diphtheria toxoid conjugate (commercially distributed as Improvac; Zoetis, Zaventem, Belgium) in male pigs raised in a commercial Greek farm. A total of 1,230 male pigs was enrolled in 16 weekly batches and allocated to 3 groups: barrows (castrated on the next day after birth [study Day 0]), pigs vaccinated with the above-mentioned product, and intact boars. Vaccinated pigs were injected subcutaneously with 2 mL of the anti-gonadotropin releasing factor (GnRF) vaccine at 9 to 11 wk of age (60-78 d) and 15 to 17 wk of age (102-120 d) and slaughtered at 22 to 25 wk of age (152-176 d). No clinical abnormalities or adverse events attributable to vaccination occurred. Mean BW of vaccinated pigs was 6% greater compared with barrows at slaughter (P < 0.0001). The vaccinated pigs had greater ADG than barrows from castration to slaughter (8%). In detail, a lower ADG from first to second vaccination (-12%; P < 0.0001) and a 27% greater ADG from second vaccination to slaughter (P < 0.0001) were observed. The ADG of vaccinated pigs and intact boars was not significantly different throughout the study, except from first to second vaccination (boars greater; P = 0.0059) and second vaccination to slaughter (vaccinates greater; P = 0.0390). Feed conversion ratio of barrows was 11 and 8% greater compared with vaccinated pigs (P = 0.0005) and boars (P = 0.0062) from first to second vaccination but was 23 to 26% lower compared with vaccinated pigs (P < 0.0001) and intact boars (P < 0.0001) from first vaccination to slaughter and 7 to 9.5% lower from the second vaccination to slaughter (P = 0.0029 and P = 0.0003 for vaccinates and intact boars, respectively). At slaughter, the belly fat androstenone concentration of all vaccinated pigs and 64% of intact boars was below 200 ng/g. Belly fat skatole concentration was below 20 ng/g in samples from all groups. In conclusion, vaccination against GnRF using the GnRF analog-diphtheria toxoid conjugate tested did not induce adverse clinical effects, proved effective, and compared with physical castration, resulted in greater BW at slaughter and improved ADG and feed conversion ratio from first vaccination to slaughter.

Clinical evaluation of intradermal vaccination against porcine enzootic pneumonia (Mycoplasma hyopneumoniae).

The aim of the present study was to investigate the efficacy of single-dose intradermal vaccination against Mycoplasma hyopneumoniae on a commercial swine unit. A total of 1051 healthy suckling piglets of 28±3 days of age were randomly assigned to one of three experimental groups: (a) intradermal: 346 piglets vaccinated intradermally (Porcilis M Hyo ID Once, Intervet SPAH), (b) intramuscular : 351 piglets vaccinated intramuscularly (Porcilis M1 Intervet SPAH) and (c) controls: 354 piglets injected with a placebo (adjuvant only). Performance parameters such as average daily weight gain (ADG), as well as health parameters and lung lesion scores were monitored from four weeks of age until slaughter. The improvement in ADG over the controls, during the finishing phase, was 27 g/day for the intradermal group and 17 g/day for the intramuscular group. Both intradermal and intramuscular vaccinations were effective in reducing clinical signs and lung lesions caused by M hyopneumoniae. Compared with the controls, approximately 10.4 per cent fewer clinical cases were diagnosed in the intradermal group, and 6 per cent fewer in the intramuscular group, during the finishing period. In conclusion, performance results were better in the vaccinated groups than in the control group, while intradermal vaccination afforded greater protection than intramuscular vaccination, especially with regard to morbidity, lung lesion and pleuritis scores.

Effect of benzoic acid and combination of benzoic acid with a probiotic containing Bacillus cereus var. Toyoi in weaned pig nutrition.

The purpose of this study was to assess the efficacy of a probiotic containing Bacillus cereus var. Toyoi spores (Toyocerin) and benzoic acid (VevoVitall) on growth performance and diarrhoea in weaning pigs, against negative controls. The trial groups were as follows: (a) NC group (Negative Controls): No treatment (b) TOYO group: Same feed as in the controls plus Toyocerin at a dose of 1 x 10(9) Bacillus cereus var. Toyoi spores/kg feed, (c) BA group: Same feed as in the controls plus VevoVitall at a dose of 5 g/kg feed (5000 ppm benzoic acid) and (d) TOYO+BA group: Same feed as in the controls plus Toyocerin at a dose of 1 x 10(9) Bacillus cereus var. Toyoi spores and VevoVitall at a dose of 5 g/kg feed. In conclusion, the results of this study indicated that administration of Bacillus cereus var. Toyoi spores at 1 x 10(9)/kg feed or benzoic acid at a dose of 5000 ppm or the combination of 1 x 10(9) Bacillus cereus var. Toyoi spores and 5000 ppm of benzoic acid/kg feed, improved the growth performance parameters and reduced the severity of diarrhoea in weaning pigs.

Effect of Origanum vulgaris and Allium sativum extracts for the control of proliferative enteropathy in weaning pigs.

The aim of the present trial was to investigate the efficacy of Virbamix PE (Virbac SA, France) an appetite enhancer and feed flavouring material containing plant extracts of Origanum vulgaris and Allium sativum, added to the feed at one single dose in the control of proliferative enteropathy (PE) in weaning pigs, in comparison to reference treatment with tiamulin (Tiamutine 6.5 Premix/Ceva Animal Health) group and a negative control group. The trial was conducted on a farm with a previous history of ileitis outbreaks. At weaning day (25 +/- 3 days old / day 0 of the trial) a total of 288 (144 male + 144 female) piglets were selected and allocated into three experimental groups, each group comprising of four pens with 24 piglets in each pen. Group 1 (T1 group) served as negative control group (unmedicated), group T2 received medication in feed at the dose of 1 kg Virbamix PE per tonne of feed and T3 group received 32 ppm of tiamulin. Treatments lasted for six weeks (up to the age of 67 +/- 3 days), and no other antibacterial or growth promoter was added to the feed or drinking water in the same period. Administration of Virbamix PE was found to be effective for the control of PE, as shown by the reduction of prevalence of Lawsonia intracellularis in the intestine at the end of the treatment period, as determined by PCR method comparatively with the T1 group, while no significant difference was found between T2 and T3 groups. The diarrhoea score (DS) was significantly higher (P < 0.05) in the control group in comparison with T2 and T3 groups. However, no significant differences were noticed between T2 and T3 groups during the treatment period (P > 0.05). Treatment of piglets with Virbamix PE and Tiamutine 6.5 Premix resulted in significantly higher body weight and average daily gain (ADG) than in T1 group for the total treatment period (P < 0.05). Conclusively, the results of present study indicate that the use of Virbamix PE, could be an alternative and economic method for the control of PE. Moreover, the use of this product is in accordance with the contemporary consumer demands for more environmentally friendly pig production, satisfying at the same time the producer needs for increased and cost-effective performance.

Performance of fattening pigs in a farm infected with both porcine reproductive and respiratory syndrome (PRRS) virus and porcine circovirus type 2 following sow and piglet vaccination with an attenuated PRRS vaccine.

The purpose of the study was to investigate whether, on farms with both post-weaning multisystemic wasting syndrome (PMWS) and porcine reproductive and respiratory syndrome (PRRS), the PRRS vaccination of sows and their fattening pigs protects against these syndromes. In a farrow-to-finish pig farm with a history of PRRS and PMWS, 200 gilts and sows were allocated to one of two groups of equal size. The first group (C-sow group) was used as untreated controls, while the animals of the second group (V-sow group) were vaccinated with live Porcilis PRRS vaccine. At the next weaning, all piglets of half the sows of the C sow group were vaccinated once at 35 days of age with the vaccine (CV group), while the offspring of the other half of the unvaccinated sows were left unvaccinated (CC group). Similarly, the offspring of half the sows of the V sow group were vaccinated (VV group), while those of the other half of the vaccinated sows were left unvaccinated (VC group). No significant differences in morbidity were observed between the groups during the nursery and finishing phases, while morbidity in the growers was significantly reduced in the CV- and VV-groups (P < 0.05). Growers' mortality was significantly reduced after piglet vaccination when compared with unvaccinated pigs of unvaccinated dams (P < 0.05). Average daily gain and feed conversion ratio were significantly improved in vaccinated piglets compared with those in the unvaccinated groups (P < 0.05).

First experience on the effect of in-feed lincomycin for the control of proliferative enteropathy in growing pigs.

This trial's aim was to evaluate the effect of in-feed lincomycin for the control of proliferative enteropathy (PE; also known as ileitis) in growing pigs, in which it is associated with significant morbidity levels. Investigation regarding the efficacy of this substance in growing pigs has never been carried out before in a field trial. The trial farm had a previous history of PE outbreaks. On day 1 of the trial (age of 62 +/- 1.5 days), 240 pigs were divided into two groups of 120 pigs/group which were allocated into five pens of 24 pigs each. Therefore, a randomized block design was used with two experimental groups (T1-T2) and five replicates (pens) per group. T1 group served as negative control (NC) animals which were receiving no medication and conversely T2 group received in-feed lincomycin at the dose of 110 mg/kg of feed. The treatment period lasted for 3 weeks, followed by an observation period of 4 weeks up to the age of 111 +/- 1.5 days which was the end of the grower stage. Administration of lincomycin at a dose of 110 mg/kg of feed had beneficial effects compared with the NC group. The pigs of T2 group showed significant improvement of their production parameters in terms of average daily body gain (ADG) and feed conversion ratio (FCR) not only during the treatment period (ADG: 0.515 +/- 0.050 versus 0.481 +/- 0.071 and FCR: 2.38 +/- 0.05 versus 2.56 +/- 0.08, for T2 and T1 groups respectively), but also during the remaining period until the end of the grower stage (observation period: ADG: 0.687 +/- 0.019 versus 0.646 +/- 0.044 and FCR: 2.58 +/- 0.02 versus 2.74 +/- 0.02 respectively). Other effects in the T2 group refer to the reduction of diarrhoea prevalence (mean pen diarrhoea score during the whole grower stage: 0.200 +/- 0.060 versus 0.632 +/- 0.041 respectively), morbidity rates (morbidity rates during the whole grower stage: 15.83% versus 45.00% respectively) and the reduction of Lawsonia intracellularis prevalence as shown by polymerase chain reaction diagnostic method (at the end of the treatment period: 10.0% versus 60.0% respectively). In conclusion, treatment with 110 mg lincomycin/kg of feed for 21 consecutive days had a beneficial effect on the control of PE in growing pigs.

Sow performance in an endemically porcine reproductive and respiratory syndrome (PRRS)-infected farm after sow vaccination with an attenuated PRRS vaccine.

The objective of this field study was to evaluate in an endemically porcine reproductive and respiratory syndrome (PRRS) virus-infected farm the reproductive performance of sows after their vaccination with a PRRS attenuated vaccine. In a farrow-to-finish pig farm with history of endemic PRRS virus infection, a total of 200 gilts and sows were used. They were divided in 2 groups of 100 animals. The first group was used as untreated controls, while the animals of the second group were vaccinated against PRRS virus using the attenuated Porcilis PRRS vaccine (Intervet International, The Netherlands) based on European strain. All health and reproductive parameters were recorded from the time of vaccination up to next weaning. No adverse systemic or local reactions or side effects relative to vaccination were noted. Compared to controls, vaccinated sows showed significantly improved farrowing rate (89% versus 78%) and a tendency for fewer returns to oestrus, particularly those at irregular intervals. Fewer sows farrowed prematurely and showed post-partum dysgalactia syndrome, but more live pigs were born and weaned in each litter after vaccination. It was concluded that vaccination of sows with Porcilis PRRS attenuated vaccine in farms with endemic PRRSV infection has beneficial effects on their health and fertility.

A field study on the effect of the dietary use of a clinoptilolite-rich tuff, alone or in combination with certain antimicrobials, on the health status and performance of weaned, growing and finishing pigs.

This study was conducted to assess the effect of dietary use of a clinoptilolite-rich tuff (Cp) on health status and performance of weaned, growing and finishing pigs and its compatibility during simultaneous oral administration of antimicrobials (AM) such as enrofloxacin (E) or salinomycin (S). Weaners (720) were assigned in 2 experimental groups and 4 subgroups based on the inclusion or not of Cp and AM in their feed (subgroups: NC, ES, Cp, Cp+ES) in order to evaluate their health status, under PWDS prevailing herd conditions. A second part of the trial aimed to the evaluation of piglet performance under conditions with minimized PWDS herd risks. For this purpose, a second set of 264 weaners were assigned in 2 groups and 4 subgroups, in a respective manner. All piglets remained on-trial until slaughtering age; Cp was incorporated in their feed at a rate of 2% from the day of weaning until slaughtering. The health status evaluation consisted in monitoring piglets for adverse effects related to Cp consumption, average daily diarrhoea scoring during weaning and mortality rate calculations throughout. Performance evaluation included individual weighing at the end of weaning, growing and fattening periods and feed consumption assessments. Average daily gain (ADG), average daily feed intake (ADFI) and feed conversion ration (FCR) on a pen basis were further calculated. Cp ingestion was well tolerated by the piglets. Simultaneous administration of Cp and AM in feed, resulted in less severe forms of PWDS, which had a shorter clinical course (P<0.05). Mortality decreased (P<0.05) during the weaning period due to AM administration. Concerning mean pig body weight at the end of each production phase, both Cp and AM had favorable effects (P<0.05). ADG estimated for the whole observation period was improved (P<0.05) by Cp-use along with AM. FCR improvements (P<0.05) were noticed during the different stages of growth due to AM or Cp administration, while Cp/AM interaction was noticed only at weaning (P<0.05).

Effect of an inactivated Parapoxvirus based immunomodulator (Baypamun) on post weaning diarrhoea syndrome and wasting pig syndrome of piglets.

Post weaning diarrhoea syndrome (PWDS) and wasting pig syndrome (WPS) are two entities of the pig industry induced by stress factors occurring at the early weaning and further complicated by opportunistic pathogens. In the present paper we examine--through one pilot and one final trial--whether prevention of these two syndromes can be achieved in the field by immunomodulation of the pig e.g., by improving its non-specific immunological response. In both trials two groups of early weaned piglets were submitted to the treatments. In the pilot trial the first group received no treatment and served as controls and the animals of the second group were injected twice with an inactivated Parapoxvirus based immunomodulator (Baypamun, Bayer, Germany). In the final trial the first group of piglets received no treatment and served as a control group. The animals of the second group were injected twice with a freeze-dried immunomodulator (Baypamun). Piglets were compared with regard to the severity of PWS, mortality, growth performance parameters, and for the presence of pathogens in their faeces. The results have shown that Baypamun treated piglets performed significantly better than negative control piglets in all the parameters examined. It was concluded that stimulation of the non-specific immunity of piglets may be helpful in preventing the appearance of PWDS and WPS in the field.