Publications by authors named "Martinez-Fernandez G"

Despite the increasing interest in developing antimethanogenic additives to reduce enteric methane (CH) emissions and the extensive research conducted over the last decades, the global livestock industry has a very limited number of antimethanogenic feed additives (AMFA) available that can deliver substantial reduction, and they have generally not reached the market yet. This work provides technical recommendations and guidelines for conducting tests intended to screen the potential to reduce, directly or indirectly, enteric CH of compounds before they can be further assessed in in vivo conditions. The steps involved in this work cover the discovery, isolation, and identification of compounds capable of affecting CH production by rumen microbes, followed by in vitro laboratory testing of potential candidates.

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  • Biochar is being studied as a supplement for ruminants to potentially reduce methane emissions from digestion, but results vary based on the type, source, and administration methods of the biochar.
  • Two experiments were conducted: the first involved 12 steers fed different biochar doses along with molasses to measure methane emissions and analyze rumen microbes over 56 days.
  • The second experiment involved 45 heifers grazing together on biochar, also mixed with molasses, for 60 days to assess its impact on productivity and methane emissions under natural grazing conditions.
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  • The study investigated the effects of the anti-methanogenic compound 3-NOP on rumen microbial profiles and fermentation in pregnant heifers and their offspring, monitoring changes up to 12 months post-treatment withdrawal.
  • Results showed significant shifts in fermentation processes, increased beneficial fatty acids, and altered microbial populations in 3-NOP treated animals, leading to a notable decrease in methane emissions during the juvenile stage.
  • Early interventions in the rumen microbiome of calves have lasting effects, with treated young animals showing a microbiome composition resembling low methane adult cattle, although the benefits diminished once the treatment ended.
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Mitigation of methane emission, a potent greenhouse gas, is a worldwide priority to limit global warming. A substantial part of anthropogenic methane is emitted by the livestock sector, as methane is a normal product of ruminant digestion. We present the latest developments and challenges ahead of the main efficient mitigation strategies of enteric methane production in ruminants.

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Nitrogen use efficiency is an important index in ruminants and can be indirectly evaluated through the N isotopic discrimination between the animal and its diet (Δ15Nanimal-diet). The concentration and source of N may determine both the extent of the N isotopic discrimination in bacteria and N use efficiency. We hypothesised that the uptake and release of ammonia by rumen bacteria will affect the natural 15N enrichment of the bacterial biomass over their substrates (Δ15Nbacteria-substrate) and thereby further impacting Δ15Nanimal-diet.

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Background: Familial papillary thyroid microcarcinoma (FPTMC) appears to be more aggressive than sporadic papillary thyroid microcarcinoma (SPTMC). However, there are authors who indicate that unicentric FPTMC has a similar prognosis to SPTMC. The objective is to analyze whether unicentric FPTMC has a better prognosis than multicentric FPTMC.

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Purpose: Familial papillary thyroid microcarcinoma (FPTMC) can present a more aggressive behavior than the sporadic microcarcinoma. However, few studies have analyzed this situation. The objective is to analyze the recurrence rate of FPTMC and the prognostic factors which determine that recurrence in Spain.

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The hyper-CVAD/methotrexate-cytarabine (H-CVAD/ MTX-AraC) chemotherapy protocol has been one of the standard treatments for hematological malignancies, such as mantle cell lymphoma (MCL), Burkitt lymphoma (BL), and B-cell and T-cell acute lymphoblastic leukemia. Because results of this therapy are poor, it has been progressively replaced with new specific regimens with better efficacy profiles (GELA protocol for MCL, BURKIMAB for BL, and PETHEMA for B-cell and T-cell acute lymphoblastic leukemia [ALL]). The objective of this study was to analyze the response rates and survival of these therapeutic regimens.

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Background And Objective: The Hyper-CVAD/Methotrexate-Cytarabine (H-CVAD/MTX-AraC) chemotherapy protocol has been one of the standard treatments for blood cancers, such as Mantle cell lymphoma (MCL), Burkitt's lymphoma (BL) and B-cell and T-cell acute lymphoblastic leukaemia (ALL). Due to high toxicity, it has been progressively replaced with new specific regimens with a better safety profile (GELA protocol for MCL, BURKIMAB for BL and PETHEMA for B-cell and T-cell ALL). The objective of this study is to analyse the toxicity and infectious complications of these therapeutic regimens, as well as the event free survival (EFS).

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This study aimed to characterize the rumen microbiota structure of cattle grazing in tropical rangelands throughout seasons and their responses in rumen ecology and productivity to a N-based supplement during the dry season. Twenty pregnant heifers grazing during the dry season of northern Australia were allocated to either N-supplemented or un-supplemented diets and monitored through the seasons. Rumen fluid, blood, and feces were analyzed before supplementation (mid-dry season), after two months supplementation (late-dry season), and post supplementation (wet season).

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Introduction: iatrogenic bile duct injury (IBDI) is a complication with a high morbidity after cholecystectomy. In recent years, endoscopy has acquired a fundamental role in the management of this pathology.

Methods: a retrospective study of IBDI after open cholecystectomy (OC) or laparoscopic cholecystectomy (LC) of patients treated in our center between 1993 and 2017 was performed.

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  • The study compares two methods for processing rumen samples from Brahman steers to assess their impact on analyzing microbial communities.
  • One method involved immediate freezing of samples, while the other included centrifugation and removal of supernatant before freezing.
  • Both methods identified key microbial groups but showed significant differences in the composition and abundance of certain bacteria and archaea, suggesting each method has its implications for rumen microbiome analysis.
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This work aimed to gain insight into the transition from milk to solid feeding at weaning combining genomics and metabolomics on rumen contents from goat kids treated with a methanogenic inhibitor (bromochloromethane, BCM). Sixteen goats giving birth to two kids were used. Eight does were treated (D+) with BCM after giving birth and over 2 months.

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  • - The study explored how 3-nitrooxypropanol (3-NOP) and chloroform affect methane production, ruminal metabolites, and microbial structure in cattle on a tropical forage diet over a 31-day period, with both treatments leading to a 30-38% reduction in methane.
  • - Treatment with 3-NOP increased daily weight gain significantly compared to chloroform and control, while both compounds elevated levels of ammonia, acetate, and branched chain fatty acids in the rumen.
  • - Microbial analyses showed similar shifts in community structure for both treatments, specifically affecting the abundance of certain archaeal families, indicating that both compounds redirected metabolic hydrogen and inhibited methanogenesis similarly despite their different mechanisms.
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  • * A study involving Brahman steers showed that using chloroform reduced methane production and increased expelled hydrogen, altering rumen fermentation patterns to favor propionate and formate over acetate.
  • * Adding phloroglucinol in conjunction with chloroform further decreased hydrogen emission and shifted fermentation back toward acetate, indicating its potential role in modifying rumen microbial communities and metabolic pathways.
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The aim of this work was to evaluate the effect of feeding management during the first month of life (natural with the mother, NAT, or artificial with milk replacer, ART) on the rumen microbial colonization and the host innate immune response. Thirty pregnant goats carrying two fetuses were used. At birth one kid was taken immediately away from the doe and fed milk replacer (ART) while the other remained with the mother (NAT).

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Management of metabolic hydrogen ([H]) in the rumen has been identified as an important consideration when reducing ruminant CH4 emissions. However, little is known about hydrogen flux and microbial rumen population responses to CH4 inhibition when animals are fed with slowly degradable diets. The effects of the anti-methanogenic compound, chloroform, on rumen fermentation, microbial ecology, and H2/CH4 production were investigated in vivo.

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Host factors are regarded as important in shaping the archaeal community in the rumen but few controlled studies have been performed to demonstrate this across host species under the same environmental conditions. A study was designed to investigate the structure of the methanogen community in the rumen of two indigenous (yak and Tibetan sheep) and two introduced domestic ruminant (cattle and crossbred sheep) species raised and fed under similar conditions on the high altitude Tibetan Plateau. The methylotrophic Methanomassiliicoccaceae was the predominant archaeal group in all animals even though Methanobrevibacter are usually present in greater abundance in ruminants globally.

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Introduction: Knowing total body volume (V) is crucial in patients on peritoneal dialysis (PD). It is usually calculated by the Watson anthropometric formula, although the use of bioimpedance spectroscopy (BIS) is becoming increasingly widespread. Measuring V with both methods can at times produce quite different results.

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  • - Japanese goats were studied to see how a diet with 50% Timothy grass and 50% concentrate, along with increasing levels of bromochloromethane (BCM), affected their rumen microbial population and fermentation processes.
  • - Researchers found that as BCM levels increased, certain microbial species, particularly hydrogen-consuming Prevotella and Selenomonas, thrived, leading to a shift in fermentation towards propionate production instead of methane.
  • - Metagenomic analyses showed that reductive acetogenic species were not significantly involved in the rumen of goats treated with BCM, indicating a distinct microbial adaptation to the changes caused by the compound.
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Study of the efficacy of methanogenesis inhibitors in the rumen has given inconsistent results, mainly due to poorly understood effects on the key microbial groups involved in pathways for methane (CH4) synthesis. The experiment described in this report was designed to assess the effect of propyl propane thiosulfinate (PTS), diallyl disulfide (DDS) and bromochloromethane (BCM) on rumen fermentation, methane production and microbial populations in continuous culture fermenters. No effects on total volatile fatty acids (VFA) were observed with PTS or DDS, but VFA were decreased with BCM.

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The aim of this work was to study whether feeding a methanogen inhibitor from birth of goat kids and their does has an impact on the archaeal population colonizing the rumen and to what extent the impact persists later in life. Sixteen goats giving birth to two kids were used. Eight does were treated (D+) with bromochloromethane after giving birth and over 2 months.

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