Growth, carcass and meat quality traits in beef from Angus, Hereford and cross-breed grazing steers, and their association with SNPs in genes related to fat deposition metabolism.

Grazing steers from Angus and Hereford breeds, their cross-breeds and a three-way cross-breed (Limousin × Angus-Hereford) were measured for growth, carcass and meat quality traits. Breed effects were studied, and the association of SNPs with fat deposition and fatty acid (FA) composition (leptin, melanocortin-4 receptor, stearoyl-CoA desaturase, FA synthase and thyroglobulin) was tested. Limousin cross-breed showed the greatest final body weight, ultrasound rib eye area, dressing percentage, carcass and leg length, and the lowest backfat thickness and intramuscular fat content. Genetic groups had similar pH, shear force, cooking loss, L* and b* and n-6:n-3 ratio. Meat from 1/2-Angus presented greater a* than Limousin cross-breed. Whereas Angus had the highest total SFA content, Hereford had the lowest total SFA and the highest total MUFA. Limousin cross-breed had greater content of several individual PUFAs, total PUFA, n-6 and n-3 FA than Angus and 1/2-Angus. Leptin and FA synthase were associated with some FAs, supporting their influence over fat metabolism for grazing animals.

Study of the influence of genes related to muscle oxidative processes on beef color.

The biochemical bases of meat color are determined by the concentration and redox state of myoglobin, hemoglobin, cytochromes, and other pigments. Post-mortem depletion of cellular oxygen results in oxidative stresses that consume NADH and affects reducing activity, while enzymatic detoxification influences the cellular oxidative processes, both affecting meat color. The aim of this work was to study the influence of several genes related to cellular oxidative processes that could affect CIELAB meat color parameters. The study was performed in steers that received a grass-based diet combined with grain, hays and silages. Results suggest a possible link between colorimetric parameters (a*, b* and chroma) and SNPs in the GSTP1 gene (P<0.05). Although the influence of the enzymes, encoded by GSTP1 gene, on meat color has been proposed previously at biochemical level and protein expression level, further association studies in different populations and functional studies of proteins are needed to confirm the genetic determination of that gene on meat color.

Genetic and management factors affecting beef quality in grazing Hereford steers.

Attributes contributing to differences in beef quality of 206 Hereford steers finished on pasture were assessed. Beef quality traits evaluated were: Warner-Bratzler meat tenderness and muscle and fat color at one and seven days after slaughter and trained sensory panel traits (tenderness, juiciness, flavor, and marbling) at seven days. Molecular markers were CAPN1 316 and an SNP in exon 2 on the leptin gene (E2FB). Average daily live weight gain, ultrasound monthly backfat thickness gain and rib-eye area gain were estimated. Molecular markers effects on meat quality traits were analyzed by mixed models. Association of meat quality with post weaning growth traits was analyzed by canonical correlations. Muscle color and marbling were affected by CAPN1 316 and E2FB and Warner-Bratzler meat tenderness by the former. The results confirm that marker assisted selection for tenderness is advisable only when beef aging is a common practice. The most important sources of variation in tenderness and color of meat remained unaccounted for.

Association of a novel polymorphism in the bovine PPARGC1A gene with growth, slaughter and meat quality traits in Brangus steers.

The PPARGC1A gene (peroxysome proliferator-activated receptor-gamma coactivator 1alpha gene) controls muscle fiber type and brown adipocyte differentiation; therefore, it is a candidate gene for beef quality traits (tenderness and fat content). Two SNPs (Single Nucleotide Polymorphisms) were identified within exon 8 by multiple alignment of DNA sequences obtained from 24 bulls: a transition G/A (SNP 1181) and a transversion A/T (SNP 1299). The SNP 1181 is a novel SNP, corresponding to a non-conservative substitution (AGT/AAT) that could be the cause of amino acid substitution ((364)Serine/(364)Asparagine). A Mismatch PCR method was designed to determine genotypes of 73 bulls and 268 steers for SNP 1181. Growth, slaughter and meat quality information were available for the group of steers. Allele A of SNP 1181 was not found in Angus. In 243 steers, no significant differences (P > 0.05) were found for either final live body weight, gain in backfat thickness in Spring, kidney fat weight, kidney fat percentage, Warner-Bratzler shear force at 7 days postmortem, intramuscular fat percentage or meat colour between genotype GG and AG. This SNP could be included in breed composition and population admixture analyses because there are marked differences in allelic frequencies between Bos taurus and Bos indicus breeds.

Effect of leptin gene polymorphisms on growth, slaughter and meat quality traits of grazing Brangus steers.

Leptin is a hormone that affects the regulation of feed intake, energy balance and body composition in mammals. Several polymorphisms in the bovine leptin gene have been associated with phenotypic variance of these traits. We evaluated two known single nucleotide polymorphisms (SNPs) in the leptin gene of 253 grazing Brangus steers. Brangus is a 5/8 Angus-3/8 Brahman composite. Data were collected during two consecutive growth/fattening cycles from two farms in southeast Buenos Aires province, Argentina. One of the markers is in the promoter region of the gene (SNP1) and the other is a non-synonymous polymorphism in exon 2 (SNP2). The traits that we evaluated were live weight gain in the spring, gain in backfat thickness in the spring, final live weight, final ultrasound backfat thickness, final ultrasound rib eye area, carcass weight and length, carcass yield, kidney fat, kidney fat percentage, backfat thickness, rib eye area, and intramuscular fat percentage. Both markers affected some meat traits; though the only significant associations were of SNP1 with ultrasound rib eye area and of SNP2 with carcass yield and backfat thickness. Under the same conditions as in the present study, leptin markers could be of help only as part of a larger genotyping panel including other relevant genes.

Valor pronóstico de la resonancia magnética en pacientes con mieloma múltiple: un estudio prospectivo / MRI prognostic value in multiple myeloma

Propósito: correlacionar los patrones de infiltración de la médula ósea (MO) por RM en pacientes con MM no tratados y valorar los resultados en conjunto con otros factores pronósticos utilizados (clínica, laboratorio, radiología). Material y métodos: evaluamos 21 pacientes con MM no tratados por RM y osteograma corporal para valorar lesiones óseas, plasmocitomas u osteoporosis. Resultados: están descriptos 3 patrones de infiltración de la MO por RM en éstos pacientes: focal (PF), difuso (PD) y variegado (PV). A diferencia de otras series, observamos estudios por RM con 2 o más patrones descriptos: 13 pacientes. Tentativamente proponemos denominar a ésta variedad de presentación, patrón mixto (PM). Conclusión: la RM es más sensible que la radiología convencional en la detección de lesiones óseas. Los patrones de infiltración de la MO por RM, combinados con el resto de factores convencionales usados, constituyen una herramienta muy útil en la determinación del pronóstico de la enfermedad. En nuestra serie, el PD, ya sea aislado o combinado con otros patrones (PM), correlacionó con factores pronósticos más severos

Estenosis carotídea exocreaneal: estudio comparativo por angiotomografía helicoidal 3-D, angio resonancia y ecodoppler color / Exocranial carotid stenosis: a comparative study between 3D-Angio CT, MR-angiography and color Doppler US

Nuestro objetivo fue valorar la utilidad de la angiotomografía computada 3D helicoidal (ATC) en relación con los métodos habituales de diagnóstico (angiorresonancia y eco Doppler), en la estenosis cartídea exocraneal. Para ello, fueron estudiadas con las tres modalidades, 32 arterias carótidas internas en 16 pacientes sintomáticos. Se realizaron las mediciones correspondientes, según el método N.A.S.C.E.T., obteniendo porcentajes de sensibilidad y especificidad de la ATC respecto a la angiorresonancia (ARM). Nuestros hallazgos permitirían incluir la ATC como segundo método prequirúrgico, en pacientes claustrofóbicos o que presenten contraindicaciones para la ARM

Disfunción patelofemoral: evaluación integral por imágenes / Patellofemoral joint disfunction. Combined diagnostic imaging: evaluation (X-Rays exams, 3D Helical CT and MRI)

Se estudiaron 43 pacientes con diagnóstico presuntivo o de certeza de inestabilidad patelofemoral. A todos los pacientes se les realizó: a) par radiológico; b) adquisiciones tomográficas en extensión y flexión, sin y con contracción, mediante un tomógrafo helicoidal y c) secuencia de RM en plano axial STIR. Los hallazgos fueron clasificados en lesiones musculares, cartilaginosas, óseas y asociadas, comparando estadísticamente los estudios. Los resultados nos permiten aceptar la hipótesis de que el estudio integral proporciona un diagnóstico más completo del origen de la disfunción patelofemoral. En el 65 por ciento de los pacientes el estudio convencional dio un resultado negativo. Sólo en el 35 por ciento de los casos el resultado fue positivo, pero en forma incompleta, mostrando únicamente el 35,3 por ciento de los hallazgos patológicos detectados por el estudio integral

Comparison of ultrasound and the Alvarado score for the diagnosis of acute appendicitis.

BACKGROUND: The Alvarado score assigns a numerical value to eight signs and symptoms associated with acute appendicitis. Practically speaking, the Alvarado score is equivalent to one's degree of clinical suspicion. Ultrasound is used in many institutions to aid in the diagnosis of acute appendicitis. The following study compares the accuracy of the two modalities and examines the value of using both modalities together. STUDY DESIGN: This study is a retrospective review of all patients who underwent appendectomy for presumed acute appendicitis at our institution in 1995. Seventy-five patients had a preoperative ultrasound and all 94 patients received an Alvarado score from a retrospective chart review. RESULTS: Ten (10.6%) patients had a normal appendix removed. Ultrasound alone resulted in a correct diagnosis 87% of the time. Using the Alvarado score alone, a correct diagnosis was made 88% of the time. If the ultrasound alone were used for diagnosis, seven acute appendices would have been missed (10% false negatives) and three unnecessary operations would have been performed (4.6% false positives). If the Alvarado score alone were used for diagnosis, four acute appendices would have been missed (5.9% false negatives) and five unnecessary operations would have been performed (7.2% false positives). There were 45 true positives and no false positive results when both modalities were positive for appendicitis. When the Alvarado score was negative or equivocal, the addition of ultrasound decreased the false negative rate by 75%. CONCLUSION: When comparing ultrasound to the Alvarado score for the diagnosis of acute appendicitis, neither one is significantly advantageous. However, the false positive rate is reduced to zero when both studies are positive and ultrasound improved diagnostic accuracy when the Alvarado score was negative or equivocal. There is no advantage of ultrasound over the Alvarado score for the diagnosis of acute appendicitis. Ultrasound is unnecessary when one's degree of clinical suspicion is high. However, the additional information provided by ultrasound does improve diagnostic accuracy in the case of a negative or equivocal Alvarado score. Acute appendicitis is the most common surgical abdominal emergency with a lifetime prevalence of approximately one in seven.

Popliteal pseudoaneurysm as a complication of an adjacent osteochondroma.

A 19-year-old man presented to our institution with a 4-month history of a pulsatile mass in the left popliteal fossa. Evaluation including plain x-ray films, MRI, and arteriography revealed a pseudoaneurysm associated with an underlying exostosis of the distal femur. The pseudoaneurysm was repaired with a saphenous vein patch and the exostosis was excised. This case is reported in conjunction with an extensive review of the literature, which yielded only 25 similar cases reported in the English language since 1953. The majority of cases involved young men (20/26), whose ages ranged from 9 to 45 years (mean 20 years). Fifteen of the 26 cases involved isolated exostoses, and in less than half (12/26), antecedent trauma was identified as a cause of the pseudoaneurysm. The origin of exostoses and their relationship to popliteal pseudoaneurysms are discussed. Repair of the pseudoaneurysm and excision of the involved exostosis are recommended.