Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.815
Filtrar
Más filtros

Intervalo de año de publicación
1.
Nature ; 576(7785): 138-142, 2019 12.
Artículo en Inglés | MEDLINE | ID: mdl-31748741

RESUMEN

Haem is an essential prosthetic group of numerous proteins and a central signalling molecule in many physiologic processes1,2. The chemical reactivity of haem means that a network of intracellular chaperone proteins is required to avert the cytotoxic effects of free haem, but the constituents of such trafficking pathways are unknown3,4. Haem synthesis is completed in mitochondria, with ferrochelatase adding iron to protoporphyrin IX. How this vital but highly reactive metabolite is delivered from mitochondria to haemoproteins throughout the cell remains poorly defined3,4. Here we show that progesterone receptor membrane component 2 (PGRMC2) is required for delivery of labile, or signalling haem, to the nucleus. Deletion of PGMRC2 in brown fat, which has a high demand for haem, reduced labile haem in the nucleus and increased stability of the haem-responsive transcriptional repressors Rev-Erbα and BACH1. Ensuing alterations in gene expression caused severe mitochondrial defects that rendered adipose-specific PGRMC2-null mice unable to activate adaptive thermogenesis and prone to greater metabolic deterioration when fed a high-fat diet. By contrast, obese-diabetic mice treated with a small-molecule PGRMC2 activator showed substantial improvement of diabetic features. These studies uncover a role for PGRMC2 in intracellular haem transport, reveal the influence of adipose tissue haem dynamics on physiology and suggest that modulation of PGRMC2 may revert obesity-linked defects in adipocytes.


Asunto(s)
Adipocitos/metabolismo , Hemo/metabolismo , Proteínas de la Membrana/metabolismo , Receptores de Progesterona/metabolismo , Animales , Homeostasis , Humanos , Espacio Intracelular/metabolismo , Masculino , Proteínas de la Membrana/deficiencia , Proteínas de la Membrana/genética , Ratones Endogámicos C57BL , Ratones Noqueados , Mitocondrias/metabolismo , Chaperonas Moleculares/metabolismo , Receptores de Progesterona/deficiencia , Receptores de Progesterona/genética , Transcripción Genética
2.
Nat Chem Biol ; 18(12): 1370-1379, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-35970996

RESUMEN

Pyrvinium is a quinoline-derived cyanine dye and an approved anti-helminthic drug reported to inhibit WNT signaling and have anti-proliferative effects in various cancer cell lines. To further understand the mechanism by which pyrvinium is cytotoxic, we conducted a pooled genome-wide CRISPR loss-of-function screen in the human HAP1 cell model. The top drug-gene sensitizer interactions implicated the malate-aspartate and glycerol-3-phosphate shuttles as mediators of cytotoxicity to mitochondrial complex I inhibition including pyrvinium. By contrast, perturbation of the poorly characterized gene C1orf115/RDD1 resulted in strong resistance to the cytotoxic effects of pyrvinium through dysregulation of the major drug efflux pump ABCB1/MDR1. Interestingly, C1orf115/RDD1 was found to physically associate with ABCB1/MDR1 through proximity-labeling experiments and perturbation of C1orf115 led to mis-localization of ABCB1/MDR1. Our results are consistent with a model whereby C1orf115 modulates drug efflux through regulation of the major drug exporter ABCB1/MDR1.


Asunto(s)
Antineoplásicos , Compuestos de Pirvinio , Humanos , Compuestos de Pirvinio/farmacología , Vía de Señalización Wnt , Antineoplásicos/farmacología , Genómica
3.
J Dairy Sci ; 107(5): 2930-2940, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-37977449

RESUMEN

Similar to all dairy systems internationally, pasture-based dairy systems are under increasing pressure to reduce their greenhouse gas (GHG) emissions. Ireland and New Zealand are 2 countries operating predominantly pasture-based dairy production systems where enteric CH4 contributes 23% and 36% of total national emissions, respectively. Ireland currently has a national commitment to reduce 51% of total GHG emissions by 2030 and 25% from agriculture by 2030, as well as striving to achieve climate neutrality by 2050. New Zealand's national commitment is to reduce 10% of methane emissions by 2030 and between 24% and 47% reduction in methane emissions by 2050. To achieve these reductions, factors that affect enteric methane (CH4) production in a pasture-based system need to be investigated. The objective of this study was to assess the relationship between enteric CH4 and other animal traits (feed intake, metabolic liveweight, energy corrected milk yield, milk urea concentration, and body condition score [BCS]) in a grazing dairy system. Enteric CH4 emissions were measured on 45 late lactation (213.8 ± 29 d after calving) grazing Holstein-Friesian and Holstein-Friesian × Jersey crossbred cows (lactation number 3.01 ± 1.65, 538.64 ± 59.37 kg live weight, and 3.14 ± 0.26 BCS) using GreenFeed monitoring equipment for 10 wk. There was a training period for the cows to use the GreenFeed of 3 wk before the 10-wk study period. The average enteric CH4 produced in the study was 352 g ± 45.7 g per day with an animal to animal coefficient of variation of 13%. Dry matter intake averaged 16.6 kg ± 2.23 kg per day, while milk solids (fat plus protein) averaged 1.62 kg ± 0.29 kg per day. A multiple linear regression model indicated that each one unit increase in energy corrected milk yield, metabolic liveweight and milk urea concentration, resulted in an increase in enteric CH4 production per day by 3.9, 1.74, and 1.38 g, respectively. Although each one unit increase in BCS resulted in a decrease in 39.03 g CH4 produced per day. When combined, these factors explained 47% of the variation in CH4 production, indicating that there is a large proportion of variation not included in the model. The repeatability of the CH4 measurements was 0.66 indicating that cows are relatively consistently exhibiting the same level of CH4 throughout the study. Therefore, enteric CH4 production is suitable for phenotyping.

4.
Surgeon ; 22(3): 166-173, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38521683

RESUMEN

BACKGROUND: Long-course neoadjuvant chemoradiotherapy (NCRT), followed by surgery after an interval of 6-8 weeks, represents standard of care for patients with locally advanced rectal cancer (LARC). Increasing this interval may improve rates of complete pathological response (pCR) and tumour downstaging. We performed a meta-analysis comparing standard (SI, within 8 weeks) versus longer (LI, after 8 weeks) interval from NCRT to surgery. METHODS: PubMed, Embase, and Cochrane databases were searched up to 31 August 2022. Randomized controlled trials (RCTs) comparing SI with LI after NCRT for LARC were included. The primary endpoint was pCR rate. Secondary endpoints included rates of R0 resection, circumferential resection margin positivity (+CRM), TME completeness, lymph node yield (LNY), operative duration, tumour downstaging (TD), sphincter preservation, mortality, postoperative complications, surgical site infection (SSI) and anastomotic leak (AL). Random effects models were used to calculate pooled effect size estimates. RESULTS: Four RCTs encompassing 867 patients were included. There were 539 males (62.1%). LI was associated with a higher pCR rate (OR 0.61, 95%CI â€‹= â€‹0.39-0.95, p â€‹= â€‹0.03), and more TD (OR 0.60, 95%CI â€‹= â€‹0.37-0.97, p â€‹= â€‹0.04) compared to SI. However, there was no difference in rates of R0 resection (p â€‹= â€‹0.87), +CRM (p â€‹= â€‹0.66), sphincter preservation (p â€‹= â€‹0.26), incomplete TME (p â€‹= â€‹0.49), LNY (p â€‹= â€‹0.55), SSI (p â€‹= â€‹0.33), AL (p â€‹= â€‹0.20), operative duration (p â€‹= â€‹0.07), mortality (p â€‹= â€‹0.89) or any surgical complication (p â€‹= â€‹0.91). CONCLUSIONS: A LI to surgery after NCRT for LARC increases pCR and TD rates. Local recurrence or survival were not assessed due to unavailable data. We recommend deferring TME until after an interval of 8 weeks following completion of NCRT.


Asunto(s)
Terapia Neoadyuvante , Ensayos Clínicos Controlados Aleatorios como Asunto , Neoplasias del Recto , Humanos , Neoplasias del Recto/terapia , Neoplasias del Recto/patología , Neoplasias del Recto/mortalidad , Tiempo de Tratamiento , Quimioradioterapia
5.
Anal Chem ; 95(47): 17284-17291, 2023 11 28.
Artículo en Inglés | MEDLINE | ID: mdl-37963318

RESUMEN

Commonly, in MS-based untargeted metabolomics, some metabolites cannot be confidently identified due to ambiguities in resolving isobars and structurally similar species. To address this, analytical techniques beyond traditional MS2 analysis, such as MSn fragmentation, can be applied to probe metabolites for additional structural information. In MSn fragmentation, recursive cycles of activation are applied to fragment ions originating from the same precursor ion detected on an MS1 spectrum. This resonant-type collision-activated dissociation (CAD) can yield information that cannot be ascertained from MS2 spectra alone, which helps improve the performance of metabolite identification workflows. However, most approaches for metabolite identification require mass-to-charge (m/z) values measured with high resolution, as this enables the determination of accurate mass values. Unfortunately, high-resolution-MSn spectra are relatively rare in spectral libraries. Here, we describe a computational approach to generate a database of high-resolution-MSn spectra by converting existing low-resolution-MSn spectra using complementary high-resolution-MS2 spectra generated by beam-type CAD. Using this method, we have generated a database, derived from the NIST20 MS/MS database, of MSn spectral trees representing 9637 compounds and 19386 precursor ions where at least 90% of signal intensity was converted from low-to-high resolution.


Asunto(s)
Metabolómica , Espectrometría de Masas en Tándem , Espectrometría de Masas en Tándem/métodos , Metabolómica/métodos , Bases de Datos Factuales , Iones/química , Flujo de Trabajo
6.
Semin Immunol ; 43: 101280, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-31221552

RESUMEN

Interferon gamma has long been studied as a critical mediator of tumor immunity. In recent years, the complexity of cellular interactions that take place in the tumor microenvironment has become better appreciated in the context of immunotherapy. While checkpoint inhibitors have dramatically improved remission rates in cancer treatment, IFN-γ and related effectors continue to be identified as strong predictors of treatment success. In this review, we provide an overview of the multiple immunosuppressive barriers that IFN-γ has to overcome to eliminate tumors, and potential avenues for modulating the immune response in favor of tumor rejection.


Asunto(s)
Biomarcadores Farmacológicos/metabolismo , Inmunoterapia/tendencias , Interferón gamma/metabolismo , Neoplasias/inmunología , Animales , Antineoplásicos Inmunológicos/uso terapéutico , Humanos , Tolerancia Inmunológica , Inmunización , Neoplasias/terapia , Microambiente Tumoral
7.
N Z Vet J ; 70(3): 138-148, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-34498540

RESUMEN

AIMS: To determine if milk composition, milk yield, live weight, live weight change, breed and heterosis are associated with reproductive performance in dairy cows from two dairy farms under New Zealand grazing conditions. METHODS: Milk composition was determined in herd tests from 205 Holstein-Friesian (F), 77 Jersey (J) and 351 F × J crossbred cows from two Massey University dairy herds in the 2016 and 2017 production seasons. Mating occurred from October to December in each production season. The start of breeding to first service (SBFS), start of breeding to conception (SBCO), submission rate at 21 days (SR21), pregnancy rate at 21 (PR21) and 42 days (PR42) were calculated for each cow. These traits were analysed using mixed linear models that included fixed effects for herd, production season, regression coefficients of deviation from median calving date, lactation number, proportion of F, F × J heterosis, energy-corrected milk yield (ECMY), percentages of fat, protein and lactose, milk urea nitrogen (MUN), live weight and change in live weight, with random effects for cow and residual error. The variables with binomial distribution were analysed using logistic regression. RESULTS: Deviation from the herd's median calving date had a significant effect (p < 0.05) on all reproductive traits. Proportion of F was significant (p = 0.022) on PR21, and F × J heterosis effects were significant on PR21 (p = 0.049) and PR42 (p = 0.046). F cows had 17.8% higher PR21 than J cows, and F × J cows had higher reproductive performance than the mean of the two purebreeds. ECMY was negatively associated with SBFS (p = 0.001) and SBCO (p = 0.001) and positively associated with PR21 (p = 0.002) and PR42 (p = 0.001). Protein percentage was positively associated (p < 0.05) with PR21 and PR42, whereas lactose percentage was negatively associated (p < 0.05) with PR21 and PR42. Cows gaining live weight were more likely to become pregnant within 21 days of the start of breeding (p = 0.020). Milk urea nitrogen was negatively associated (p = 0.042) with SR21. CONCLUSIONS AND CLINICAL RELEVANCE: This study confirms that breed, heterosis, ECMY, protein and lactose percentages, live weight change and calving date are associated with the reproductive performance of grazing cows. Results from this study contrast with the historical antagonism between milk production and reproductive performance in dairy cattle, demonstrating that well managed cows can achieve high levels of production and good reproductive performance. MUN was not associated with reproductive performance traits, except with SR21.


Asunto(s)
Industria Lechera , Leche , Animales , Bovinos , Industria Lechera/métodos , Granjas , Femenino , Humanos , Lactancia , Leche/metabolismo , Nueva Zelanda , Embarazo
8.
Nat Methods ; 15(9): 681-684, 2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-30150755

RESUMEN

We report XCMS-MRM and METLIN-MRM ( http://xcmsonline-mrm.scripps.edu/ and http://metlin.scripps.edu/ ), a cloud-based data-analysis platform and a public multiple-reaction monitoring (MRM) transition repository for small-molecule quantitative tandem mass spectrometry. This platform provides MRM transitions for more than 15,500 molecules and facilitates data sharing across different instruments and laboratories.


Asunto(s)
Nube Computacional , Bibliotecas de Moléculas Pequeñas/química , Cromatografía Liquida/métodos , Biología Computacional , Metabolómica , Espectrometría de Masas en Tándem
9.
Pharmacogenomics J ; 21(4): 510-519, 2021 08.
Artículo en Inglés | MEDLINE | ID: mdl-33731881

RESUMEN

Previous research has identified differences in mutation frequency in genes implicated in chemotherapy resistance between mucinous and non-mucinous colorectal cancers (CRC). We hypothesized that outcomes in mucinous and non-mucinous CRC may be influenced by expression of genes responsible for chemotherapy resistance. Gene expression data from primary tumor samples were extracted from The Cancer Genome Atlas PanCancer Atlas. The distribution of clinical, pathological, and gene expression variables was compared between 74 mucinous and 521 non-mucinous CRCs. Predictors of overall survival (OS) were assessed in a multivariate analysis. Kaplan-Meier curves were constructed to compare survival according to gene expression using the log rank test. The median expression of 5-FU-related genes TYMS, TYMP, and DYPD was significantly higher in mucinous CRC compared to non-mucinous CRC (p < 0.001, p = 0.003, p < 0.001, respectively). The median expression of oxaliplatin-related genes ATP7B and SRPK1 was significantly reduced in mucinous versus non-mucinous CRC (p = 0.004, p = 0.007, respectively). At multivariate analysis, age (odds ratio (OR) = 0.96, p < 0.001), node positive disease (OR = 0.49, p = 0.005), and metastatic disease (OR = 0.32, p < 0.001) remained significant negative predictors of OS, while high SRPK1 remained a significant positive predictor of OS (OR = 1.59, p = 0.037). Subgroup analysis of rectal cancers demonstrated high SRPK1 expression was associated with significantly longer OS compared to low SRPK1 expression (p = 0.011). This study highlights that the molecular differences in mucinous CRC and non-mucinous CRC extend to chemotherapy resistance gene expression. SRPK1 gene expression was associated with OS, with a prognostic role identified in rectal cancers.


Asunto(s)
Neoplasias Colorrectales/genética , Resistencia a Antineoplásicos/genética , Inactivación Metabólica/genética , Anciano , ATPasas Transportadoras de Cobre/genética , Femenino , Expresión Génica/genética , Humanos , Masculino , Pronóstico , Proteínas Serina-Treonina Quinasas/genética
10.
BMC Nephrol ; 22(1): 291, 2021 08 26.
Artículo en Inglés | MEDLINE | ID: mdl-34445981

RESUMEN

BACKGROUND: Percutaneous kidney biopsy is the gold standard investigation for the diagnosis of kidney diseases. The associated risks of the procedure depend on the skill and experience of the proceduralist as well as the characteristics of the patient. The Kidney Health Australia - Caring for Australasians with Renal Impairment (KHA-CARI) guidelines on kidney biopsies, published in 2019, are the only published national kidney biopsy guidelines. As such, this study surveys current kidney biopsy practices in Australasia and examines how they align with the Australian guidelines, as well as international biopsy practice. METHODS: A cross-sectional, multiple-choice questionnaire was developed examining precautions prior to kidney biopsy; rationalisation of medications prior to kidney biopsy; technical aspects of kidney biopsy; complications of kidney biopsy; and indications for kidney biopsy. This was distributed to all members of the Australian and New Zealand Society of Nephrology (ANZSN). RESULTS: The response rate for this survey is approximately 21.4 % (182/850). Respondents found agreement (> 75.0 %) in only six out of the twelve questions (50.0 %) which assessed their practice against the KHA-CARI guidelines. CONCLUSIONS: This is the first study of its kind where kidney biopsy practices are examined against a clinical guideline. Furthermore, responses showed that practices were incongruent with guidelines and that there was a lack of consensus on many issues.


Asunto(s)
Biopsia/estadística & datos numéricos , Adhesión a Directriz/estadística & datos numéricos , Riñón/patología , Nefrólogos/estadística & datos numéricos , Pautas de la Práctica en Medicina/estadística & datos numéricos , Australasia , Biopsia/efectos adversos , Biopsia/métodos , Estudios Transversales , Humanos , Enfermedades Renales/patología , Guías de Práctica Clínica como Asunto , Encuestas y Cuestionarios
11.
Nat Chem Biol ; 14(1): 22-28, 2018 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-29131145

RESUMEN

Endogenous metabolites play essential roles in the regulation of cellular identity and activity. Here we have investigated the process of oligodendrocyte precursor cell (OPC) differentiation, a process that becomes limiting during progressive stages of demyelinating diseases, including multiple sclerosis, using mass-spectrometry-based metabolomics. Levels of taurine, an aminosulfonic acid possessing pleotropic biological activities and broad tissue distribution properties, were found to be significantly elevated (∼20-fold) during the course of oligodendrocyte differentiation and maturation. When added exogenously at physiologically relevant concentrations, taurine was found to dramatically enhance the processes of drug-induced in vitro OPC differentiation and maturation. Mechanism of action studies suggest that the oligodendrocyte-differentiation-enhancing activities of taurine are driven primarily by its ability to directly increase available serine pools, which serve as the initial building block required for the synthesis of the glycosphingolipid components of myelin that define the functional oligodendrocyte cell state.


Asunto(s)
Diferenciación Celular/fisiología , Metabolómica/métodos , Células Precursoras de Oligodendrocitos , Taurina/metabolismo , Diferenciación Celular/efectos de los fármacos , Glicoesfingolípidos/biosíntesis , Redes y Vías Metabólicas , Vaina de Mielina/metabolismo , Células Precursoras de Oligodendrocitos/citología , Células Precursoras de Oligodendrocitos/fisiología , Serina/metabolismo , Taurina/farmacología
12.
Gynecol Oncol ; 158(2): 431-439, 2020 08.
Artículo en Inglés | MEDLINE | ID: mdl-32451123

RESUMEN

BACKGROUND: BRCA1/2 mutation status has increasing relevance for ovarian cancer treatments, making traditional coordination of genetic testing by genetic services unsustainable. Consequently alternative models of genetic testing have been developed to improve testing at the initial diagnosis for all eligible women. METHODS: A training module to enable mainstreamed genetic testing by oncology healthcare professionals was developed by genetic health professionals. Oncology healthcare professionals completed questionnaires before and 12 months post-training to assess perceived skills, competence and barriers to their coordinating genetic testing for women with high-grade non-mucinous epithelial ovarian cancer. Genetic health professionals were surveyed 12 months post-training to assess perceived barriers to implementation of mainstreaming. RESULTS: 185 oncology healthcare professionals were trained in 42 workshops at 35 Australasian hospitals. Of the 273 tests ordered by oncology healthcare professionals post-training, 241 (93.1%) met national testing guidelines. The number of tests ordered by genetic health professionals reduced significantly (z = 45.0, p = 0.008). Oncology healthcare professionals' perceived barriers to mainstreamed testing decreased from baseline to follow-up (t = 2.39, p = 0.023), particularly perceived skills, knowledge and attitudes. However, only 58% reported either 'always' or 'nearly always' having ordered BRCA testing for eligible patients at 12 months, suggesting oncology healthcare professionals' perceived barriers were not systematically addressed through training. CONCLUSIONS: Oncology healthcare professionals have demonstrated a willingness to be involved in the provision of genetic testing in a mainstreaming model. If oncology services are to hold responsibility for coordinating genetic testing, their readiness will require understanding of barriers not addressed by training alone to inform future intervention design.


Asunto(s)
Carcinoma Epitelial de Ovario/genética , Pruebas Genéticas/métodos , Genética/educación , Oncología Médica/educación , Neoplasias Ováricas/genética , Adolescente , Adulto , Proteína BRCA1/genética , Proteína BRCA2/genética , Educación Médica Continua , Femenino , Personal de Salud/educación , Humanos , Masculino , Persona de Mediana Edad , Adulto Joven
13.
Colorectal Dis ; 22(9): 1076-1084, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32052545

RESUMEN

AIM: The diagnostic role for preoperative imaging of clinically benign rectal adenomas is unclear. The objective of this systematic review and meta-analysis was to examine the diagnostic accuracy of preoperative imaging in distinguishing benign adenomas from rectal cancer. METHOD: A systematic search was performed for all studies published that correlated staging of clinically benign rectal adenomas with endorectal ultrasound (ERUS) or MRI and histology. Imaging was compared with postoperative histology and data on the numbers of true positives, false positives, true negatives and false negatives were extracted. Summary estimates of sensitivity and specificity with 95% CIs were calculated using a bivariate random effects model. The QUADAS2 tool was used to determine the methodological quality of included studies. RESULTS: Eleven studies describing 1511 patients were retrieved. A total of 1134 patients underwent local excision and 377 had a formal proctectomy. A benign rectal adenoma was diagnosed in 840 and 214 had a T1 rectal cancer. For confirming benign adenomas, the pooled sensitivity of ERUS was 0.81 (95% CI 0.69-0.89) and specificity was 0.85 (95% CI 0.68-0.93). For detecting occult T1 tumours, the pooled sensitivity of ERUS was 0.50 (95% CI 0.33-0.66) and specificity was 0.89 (95% CI 0.82-0.94). Quantitative analysis of MRI could not be performed due to insufficient studies. CONCLUSION: This study demonstrates the limited accuracy of preoperative ERUS in distinguishing benign adenomas from T1 rectal cancer. Preoperative imaging must be interpreted with caution to prevent over-staging and unnecessary proctectomy. We propose that clinically benign lesions may undergo local excision, with subsequent management based on final histology.


Asunto(s)
Endosonografía , Neoplasias del Recto , Humanos , Imagen por Resonancia Magnética , Estadificación de Neoplasias , Cuidados Preoperatorios , Neoplasias del Recto/diagnóstico por imagen , Neoplasias del Recto/patología , Neoplasias del Recto/cirugía , Sensibilidad y Especificidad
14.
Anim Genet ; 51(2): 330-335, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-31900974

RESUMEN

Resistance to gastrointestinal nematodes has previously been shown to be a moderately heritable trait in some breeds of sheep, but the mechanisms of resistance are not well understood. Selection for resistance currently relies upon faecal egg counts (FEC), blood packed cell volumes and FAMACHA visual indicator scores of anaemia. Identifying genomic markers associated with disease resistance would potentially improve the selection process and provide a more reliable means of classifying and understanding the biology behind resistant and susceptible sheep. A GWAS was conducted to identify possible genetic loci associated with resistance to Haemonchus contortus in Katahdin sheep. Forty animals were selected from the top and bottom 10% of estimated breeding values for FEC from a total pool of 641 sires and ram lambs. Samples were genotyped using Applied Biosystems™ Axiom™ Ovine Genotyping Array (50K) consisting of 51 572 SNPs. Following quality control, 46 268 SNPs were included in subsequent analyses. Analyses were conducted using a linear regression model in plink v1.90 and a single-locus mixed model in snp and variation suite. Genome-wide significance was determined by a Bonferroni correction for multiple testing. Using linear regression, loci on chromosomes 2, 3, 16, 23 and 24 were significantly associated at the genome level with FEC estimated breeding values, and we identified a region on chromosome 2 that was significant using both statistical analyses. We suggest a potential role for the gene DIS3L2 for gastrointestinal nematode resistance in Katahdin sheep, although further research is needed to validate these findings.


Asunto(s)
Resistencia a la Enfermedad/genética , Enfermedades Gastrointestinales/veterinaria , Sitios Genéticos , Estudio de Asociación del Genoma Completo/veterinaria , Hemoncosis/veterinaria , Enfermedades de las Ovejas/genética , Animales , Enfermedades Gastrointestinales/genética , Enfermedades Gastrointestinales/parasitología , Hemoncosis/genética , Hemoncosis/parasitología , Ovinos , Enfermedades de las Ovejas/parasitología
15.
J Dairy Sci ; 103(3): 2405-2418, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-31954581

RESUMEN

We previously generated a high-metabolizable energy (HME) perennial ryegrass (Lolium perenne) by genetically modifying the plant to increase the leaf lipid content. Although substantial progress has been made toward characterizing physiological changes of HME ryegrass, very limited information exists for feeding value and its suitability for adoption into the pastoral system. In this study, independent HME ryegrass lines with a range of elevated leaf lipid concentrations were analyzed for changes in fatty acids and possible associated changes in the broader nutritional profile, including the gross energy, which was found to increase by 6.8%. Because ryegrass is often ensiled and fermentation in the rumen leads to biohydrogenation of fatty acids as well as enteric methane production, we sought to investigate these effects on HME ryegrass. This was achieved by performing mini-scale silos and using an automated gas measurement system to incubate the material in rumen fluid in vitro for 24 h. Our study included treatments comprising 3 independent HME ryegrass genotypes and wild-type control materials prepared fresh and as silage, employing in total 5 incubation studies, using rumen fluids collected from 4 nonlactating Jersey × Holstein cows. At intervals during the incubation, the production of gases, volatile fatty acids, and the degree of biohydrogenation were measured. Statistical data analysis indicated that differences in the nutritional compositions of the ensiled materials largely reflected those of their fresh counterparts. Incubation of both fresh and ensiled HME ryegrass in rumen fluid resulted in: (1) a greater percentage of valuable unsaturated fatty acids compared with the control; (2) a significant reduction of butyrate; and (3) a 10 to 15% decrease in the methane proportion of the total gas production. We conclude that ensiling could be a convenient option for preserving HME as a locally produced high-value supplementary feed; however, large-scale application needs to be investigated. In this paper we discuss the potential use of HME ryegrass to enhancing forage feeding value and the potential environmental benefits to the pastoral agriculture industry.


Asunto(s)
Bovinos/metabolismo , Lolium/metabolismo , Metano/biosíntesis , Rumen/metabolismo , Ensilaje , Animales , Butiratos/metabolismo , Digestión , Metabolismo Energético , Ácidos Grasos Volátiles/metabolismo , Femenino , Fermentación , Lolium/genética , Plantas Modificadas Genéticamente
16.
Anal Chem ; 91(5): 3246-3253, 2019 03 05.
Artículo en Inglés | MEDLINE | ID: mdl-30681830

RESUMEN

Computational metabolite annotation in untargeted profiling aims at uncovering neutral molecular masses of underlying metabolites and assign those with putative identities. Existing annotation strategies rely on the observation and annotation of adducts to determine metabolite neutral masses. However, a significant fraction of features usually detected in untargeted experiments remains unannotated, which limits our ability to determine neutral molecular masses. Despite the availability of tools to annotate, relatively few of them benefit from the inherent presence of in-source fragments in liquid chromatography-electrospray ionization-mass spectrometry. In this study, we introduce a strategy to annotate in-source fragments in untargeted data using low-energy tandem mass spectrometry (MS) spectra from the METLIN library. Our algorithm, MISA (METLIN-guided in-source annotation), compares detected features against low-energy fragments from MS/MS spectra, enabling robust annotation and putative identification of metabolic features based on low-energy spectral matching. The algorithm was evaluated through an annotation analysis of a total of 140 metabolites across three different sets of biological samples analyzed with liquid chromatography-mass spectrometry. Results showed that, in cases where adducts were not formed or detected, MISA was able to uncover neutral molecular masses by in-source fragment matching. MISA was also able to provide putative metabolite identities via two annotation scores. These scores take into account the number of in-source fragments matched and the relative intensity similarity between the experimental data and the reference low-energy MS/MS spectra. Overall, results showed that in-source fragmentation is a highly frequent phenomena that should be considered for comprehensive feature annotation. Thus, combined with adduct annotation, this strategy adds a complementary annotation layer, enabling in-source fragments to be annotated and increasing putative identification confidence. The algorithm is integrated into the XCMS Online platform and is freely available at http://xcmsonline.scripps.edu .


Asunto(s)
Metaboloma , Metabolómica/métodos , Algoritmos , Aminoácidos/química , Aminoácidos/metabolismo , Animales , Encéfalo/metabolismo , Cromatografía Líquida de Alta Presión , Creatina/análisis , Creatina/metabolismo , Bases de Datos Factuales , Ratones , Espectrometría de Masas en Tándem
17.
Br J Surg ; 106(6): 682-691, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-30945755

RESUMEN

BACKGROUND: Mucinous differentiation occurs in 5-15 per cent of colorectal adenocarcinomas. This subtype of colorectal cancer responds poorly to chemoradiotherapy and has a worse prognosis. The genetic aetiology underpinning this cancer subtype lacks consensus. The aim of this study was to use meta-analytical techniques to clarify the molecular associations of mucinous colorectal cancer. METHODS: This study adhered to MOOSE guidelines. Databases were searched for studies comparing KRAS, BRAF, microsatellite instability (MSI), CpG island methylator phenotype (CIMP), p53 and p27 status between patients with mucinous and non-mucinous colorectal adenocarcinoma. A random-effects model was used for analysis. RESULTS: Data from 46 studies describing 17 746 patients were included. Mucinous colorectal adenocarcinoma was associated positively with KRAS (odds ratio (OR) 1·46, 95 per cent c.i. 1·08 to 2·00, P = 0·014) and BRAF (OR 3·49, 2·50 to 4·87; P < 0·001) mutation, MSI (OR 3·98, 3·30 to 4·79; P < 0·001) and CIMP (OR 3·56, 2·85 to 4·43; P < 0·001), and negatively with altered p53 expression (OR 0·46, 0·31 to 0·67; P < 0·001). CONCLUSION: The genetic origins of mucinous colorectal adenocarcinoma are predominantly associated with BRAF, MSI and CIMP pathways. This pattern of molecular alterations may in part explain the resistance to standard chemotherapy regimens seen in mucinous adenocarcinoma.


Asunto(s)
Adenocarcinoma Mucinoso/genética , Biomarcadores de Tumor/genética , Neoplasias Colorrectales/genética , Regulación Neoplásica de la Expresión Génica , Adenocarcinoma Mucinoso/patología , Neoplasias Colorrectales/patología , Islas de CpG/genética , Metilación de ADN , Humanos , Inestabilidad de Microsatélites , Modelos Estadísticos , Mutación , Fenotipo , Antígeno Nuclear de Célula en Proliferación/genética , Proteínas Proto-Oncogénicas B-raf/genética , Proteínas Proto-Oncogénicas p21(ras)/genética , Proteína p53 Supresora de Tumor/genética
18.
Glob Chang Biol ; 25(3): 1171-1189, 2019 03.
Artículo en Inglés | MEDLINE | ID: mdl-29808518

RESUMEN

Contemporary climate change in Alaska has resulted in amplified rates of press and pulse disturbances that drive ecosystem change with significant consequences for socio-environmental systems. Despite the vulnerability of Arctic and boreal landscapes to change, little has been done to characterize landscape change and associated drivers across northern high-latitude ecosystems. Here we characterize the historical sensitivity of Alaska's ecosystems to environmental change and anthropogenic disturbances using expert knowledge, remote sensing data, and spatiotemporal analyses and modeling. Time-series analysis of moderate-and high-resolution imagery was used to characterize land- and water-surface dynamics across Alaska. Some 430,000 interpretations of ecological and geomorphological change were made using historical air photos and satellite imagery, and corroborate land-surface greening, browning, and wetness/moisture trend parameters derived from peak-growing season Landsat imagery acquired from 1984 to 2015. The time series of change metrics, together with climatic data and maps of landscape characteristics, were incorporated into a modeling framework for mapping and understanding of drivers of change throughout Alaska. According to our analysis, approximately 13% (~174,000 ± 8700 km2 ) of Alaska has experienced directional change in the last 32 years (±95% confidence intervals). At the ecoregions level, substantial increases in remotely sensed vegetation productivity were most pronounced in western and northern foothills of Alaska, which is explained by vegetation growth associated with increasing air temperatures. Significant browning trends were largely the result of recent wildfires in interior Alaska, but browning trends are also driven by increases in evaporative demand and surface-water gains that have predominately occurred over warming permafrost landscapes. Increased rates of photosynthetic activity are associated with stabilization and recovery processes following wildfire, timber harvesting, insect damage, thermokarst, glacial retreat, and lake infilling and drainage events. Our results fill a critical gap in the understanding of historical and potential future trajectories of change in northern high-latitude regions.


Asunto(s)
Cambio Climático , Ecosistema , Monitoreo del Ambiente/métodos , Tecnología de Sensores Remotos , Alaska , Regiones Árticas , Hielos Perennes , Desarrollo de la Planta , Análisis Espacio-Temporal , Temperatura
19.
Phys Rev Lett ; 122(5): 052502, 2019 Feb 08.
Artículo en Inglés | MEDLINE | ID: mdl-30822004

RESUMEN

The neutron-capture reaction plays a critical role in the synthesis of the elements in stars and is important for societal applications including nuclear power generation and stockpile-stewardship science. However, it is difficult-if not impossible-to directly measure neutron capture cross sections for the exotic, short-lived nuclei that participate in these processes. In this Letter we demonstrate a new technique which can be used to indirectly determine neutron-capture cross sections for exotic systems. This technique makes use of the (d,p) transfer reaction, which has long been used as a tool to study the structure of nuclei. Recent advances in reaction theory, together with data collected using this reaction, enable the determination of neutron-capture cross sections for short-lived nuclei. A benchmark study of the ^{95}Mo(d,p) reaction is presented, which illustrates the approach and provides guidance for future applications of the method with short-lived isotopes produced at rare isotope accelerators.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA