Quantitative trait loci exploration and characterization of gestation length in Holstein cattle.

Gestation length (GL) is a moderately heritable trait in cattle with economic and management implications. This study aimed to characterize the gestation length of an Argentinian Holstein cattle population, understand contributing factors, and explore the GL effect on production performance. Further objectives were to estimate direct and maternal heritabilities for this trait and to identify genomic regions affecting it. Data consisted of GL records from 45,738 births corresponding to 17,004 Holstein cows and heifers. The effects of age and calving season over GL were analyzed using a Student's t-test for homoscedastic samples. The effects of the GL category (GL shorter than 1.5 SD, within ±1.5 SD, and longer than 1.5 SD from the mean) on production performance were studied by analysis of variance. A single-step genome-wide association study was performed using the BLUPF90 suite of programs with genotypes from 654 Holstein animals on 40,339 SNP. The results showed that the younger the age at calving, the shorter the GL. Moreover, gestations ending in warmer seasons were, in general, statistically shorter than those ending in colder seasons for both heifers and cows. Regarding the effect of GL on production performance, cows with gestation periods within ±1.5 SD from the population mean exhibited the highest 305-day cumulative milk, fat, and protein productions. Direct and maternal heritabilities for GL were 0.42 and 0.03, respectively. We detected a SNP suggestively associated with direct gestation length at 57.7 Mb on Bos taurus autosome 18, a locus included in a region described in the literature as associated with the trait. The information obtained on the environmental and genetic factors affecting GL in Argentinian Holstein cows contributes to characterizing the population in pursuit of improving the performance of national dairy cattle breeding systems.

BOLA-DRB3 gene polymorphisms influence bovine leukaemia virus infection levels in Holstein and Holstein × Jersey crossbreed dairy cattle.

Bovine leukemia virus (BLV) infections, causing persistent lymphocytosis and lethal lymphosarcoma in cattle, have reached high endemicity on dairy farms. We observed extensive inter-individual variation in the level of infection (LI) by assessing differences in proviral load in peripheral blood. This phenotypic variation appears to be determined by host genetics variants, especially those located in the BoLA-DRB3 MHCII molecule. We performed an association study using sequencing-based typed BOLA-DRB3 alleles from over 800 Holstein and Holstein × Jersey cows considering LI in vivo and accounting for filial relationships. The DBR3*0902 allele was associated with a low level of infection (LLI) (<1% of circulating infected B-cells), whereas the DRB3*1001 and DRB3*1201 alleles were related to a high level of infection (HLI). We found evidence that 13 polymorphic positions located in the pockets of the peptide-binding cleft of the BOLA-DRB3 alleles were associated with LI. DRB3*0902 had unique haplotypes for each of the pockets: Ser13 -Glu70 -Arg71 -Glu74 (pocket 4), Ser11 -Ser30 (pocket 6), Glu28 -Trp61 -Arg71 (pocket 7) and Asn37 -Asp57 (pocket 9), and all of them were significantly associated with LLI. Conversely, Lys13 -Arg70 -Ala71 -Ala74 and Ser13 -Arg70 -Ala71 -Ala74 , corresponding to the DRB3*1001 and *1201 alleles respectively, were associated with HLI. We showed that the specific amino acid pattern in the DRB3*0902 peptide-binding cleft may be related to the set point of a very low proviral load level in adult cows. Moreover, we identified two BOLA-DRB3 alleles associated with a HLI, which is compatible with a highly contagious profile.

Impact of granulocyte colony-stimulating factors in metastatic colorectal cancer patients.

BACKGROUND: Delays in chemotherapy because of neutropenia may be associated with poorer outcomes. The purpose of the present study was to examine the effect that granulocyte colony-stimulating factors (g-csfs) have on survival. METHODS: We conducted a chart review of all outpatients diagnosed with metastatic colorectal cancer and treated with folfiri chemotherapy (irinotecan, 5-fluorouracil, leucovorin) with or without bevacizumab at Mount Sinai Hospital between 2007 and 2012. Multivariable Cox proportional hazards models were used to compare survival in neutropenic patients treated with g-csf, in neutropenic patients not so treated, and in patients without neutropenia. RESULTS: The review identified 93 patients, 31 of whom did not experience a neutropenic event. Of the 62 who experienced neutropenia, 18 were managed with g-csf support, and 44, with reductions or delays in dose. Compared with patients experiencing a neutropenic episode not treated with g-csf, those treated with g-csf experienced a nonsignificant increase in time to event [progression or death: hazard ratio (hr): 1.37; 95% confidence limits (cl): 0.72, 2.61], but compared with patients not having a neutropenic episode, the same patients experienced a significant increase in time to event (hr: 2.07; 95% cl: 1.03, 4.15). CONCLUSIONS: In patients who experienced neutropenia, g-csf did not have a statistically significant impact on survival. Time to event was prolonged in g-csf-treated patients compared with patients who did not experience neutropenia.

Identification of cattle carrying alleles associated with resistance and susceptibility to the Bovine Leukemia Virus progression by real-time PCR.

Previous studies have shown a significant association between polymorphisms of the BoLA DRB3 gene and Bovine Leukemia Virus (BLV) infection profile. The presence of allele *1501 has been associated with high proviral load in peripheral blood while allele *0902 has been associated with low proviral load. The purpose of this study was to develop allele-specific real-time PCRs to identify cattle carrying alleles associated with resistance (BoLA DRB3*0902) or susceptibility (BoLA DRB3*1501) to the BLV progression. Specific primers were designed and differential amplification was carried out by real-time PCR and monitored by SYBR® Green dye in DNA samples from peripheral blood. Conditions were also adjusted for traditional PCR amplification (end point amplification). These methods are rapid, simple and suitable for high throughput screening, and could aid in marker-assisted selection of BLV-resistant and susceptible cattle.

CAPN1 markers in three Argentinean cattle breeds: report of a new InDel polymorphism within intron 17.

In this study, the genotype distribution and allelic frequencies of CAPN1 (Calcium activated neutral protease) single nucleotide polymorphisms (SNPs) were analyzed taking advantage of the different genetic backgrounds provided by Hereford, Brahman and Braford cattle. We report a new insertion/deletion (InDel) polymorphism, consisting of a change of seven nucleotides for only one nucleotide (TCTGGGT → C) within intron 17 of the CAPN1 gene. The segregation pattern of this polymorphism was analyzed together with the markers CAPN316, CAPN530 and CAPN4751 already described. The allele distribution of CAPN1 markers in the Braford crossbreed (3/8 Brahman 5/8 Hereford) is described for the first time. Four assays of allelic discrimination were designed: the tetra primer ARMS-PCR technique for genotyping the new InDel and the CAPN4751 marker, and a PCR-RFLP method for genotyping the markers CAPN316 and CAPN530. The genotypic and minor allele frequencies (MAFs) obtained showed that the InDel polymorphism does not provide redundant information to that already provided by the other CAPN1 markers and segregates differently between breeds, being a common SNP (MAF ≥ 0.05) in the herds with a high percentage of Bos indicus background. The high percentage of heterozygous individuals found in the Braford crossbreed for the markers assessed reveals enough genetic variation that could help to solve the tenderness problem of tropical-adapted cattle.

Combined hyperlipidemia/hyperalphalipoproteinemia associated with premature spontaneous atherosclerosis in mice lacking hepatic lipase and low density lipoprotein receptor.

BACKGROUND AND METHODS: Hepatic lipase (HL) is an enzyme which hydrolyzes triglycerides from plasma lipoproteins and thus takes part in the metabolism of triglyceride-rich lipoprotein remnants and high density lipoproteins. The search described here concentrated on the description of the double invalidation of the HL and LDL receptor genes in mice in order to better understand the possible role of HL in combined hyperlipidemia/hyperalphalipoproteinemia and development of atherosclerosis. RESULTS: We show here that mice lacking both endogenous HL and LDL receptor (HL-/-:LDLR-/-) dramatically increased their plasma triglyceride-rich lipoproteins and their remnants as a consequence of reduced liver uptake. This result is strenghthened by the fact that HL-/-:LDLR-/- were found to overexpress LRP, LSR, and apoE genes. Interestingly, HL-/-:LDLR-/- mice showed premature spontaneous atherosclerosis and aortic lesions from 1-year-old animals were two-fold larger than those of LDLR-/- single mutants. We confirmed that HL-/- and wild-type mice did not develop atherosclerosis lesion even 1 year after birth. CONCLUSIONS: Analysis of this double HL-LDLR knockout mouse model provides in vivo evidence that HL has a major role in the clearance of TRL remnants when LDLR is deficient and in the reduction of the development of atherosclerosis.

Further analysis of VNTR and MIRU in the genome of Mycobacterium avium complex, and application to molecular epidemiology of isolates from South America.

All members of Mycobacterium avium complex are serious pathogens for humans and animals. The aim of this study was to look for and analyze VNTR-MIRU loci in the genome of M. avium complex and their preliminary application to test these isolates. In the present study, we identified 22 novel VNTR-MIRU by using Tandem Repeat software: five with a structure similar to MIRU and 17 without MIRU structure; these latter were designated as VNTR. Most VNTR were located within predicted coding regions. Most MIRU were intercistronic with their extremities overlapping the termination and initiation codons of their flanking genes. Some of these VNTR-MIRU exhibited polymorphism among M. avium complex isolates due to insertion or deletion of whole repeats and/or of nucleotide sequence degeneration. We determined the variability of six VNTR-MIRU loci in 21 M. avium subsp. hominissuis and 26 M. avium subsp. paratuberculosis. The analysis identified 15 different alleles with the combination of six VNTR-MIRU in the 21 M. avium subsp. hominissuis with 16 different IS1245 RFLP and four different profiles with PCR-restriction analysis of hsp65 (PRA). However, neither the six VNTR-MIRU loci nor the PRA were able to distinguish M. avium subsp. paratuberculosis isolates with five different IS900 RFLP profiles. In conclusion, some of the VNTR-MIRU loci identified were useful to differentiate M. avium subsp. hominissuis but not M. avium subsp. paratuberculosis isolates here included. However, we observed polymorphism in VNTR-MIRU loci between M. avium subsp. hominissuis and M. avium subsp. paratuberculosis genomes, which could be important in the understanding of the obvious differences in the pathogenic effects of these mycobacteria.

Influence of the diabetic neuropathy on the behavior of electromyographic and sensorial responses in treadmill gait.

OBJECTIVE: We describe and interpret self-cadence treadmill walking by neuropathic diabetic subjects under biomechanical and somatosensorial considerations. DESIGN: EMG variables during stance phase of neuropathic diabetic subjects were acquired and analyzed. We also evaluated sensorial and motor aspects of the feet and legs. METHODS: The experimental procedures are divided as follows: (a) determination of the sensitive cronaxie and pain tolerance in selected plantar areas, (b) determination and description of temporal aspects of EMG patterns of the vastus lateralis, tibialis anterior and lateral gastrocnemius of both sides during treadmill walking. We analyze and compare the results of the sensitive cronaxie, pain tolerance and the EMG parameters obtained by two experimental groups: diabetic neuropathic (n=20) and non-diabetic control subjects (n=20). RESULTS: The somatosensorial responses and pain tolerance threshold in the diabetic neuropathic group were significantly higher and considered far from the normal patterns. The EMG responses of the thigh and leg muscles in the diabetic neuropathic group were delayed if compared to the normal recruitment pattern, especially the tibialis anterior and vastus lateralis. CONCLUSIONS: These findings lead us to conclude that probably central and/or peripheral control mechanisms of the gait of neuropathic diabetic patients are altered due to somatosensorial and motor deficits. The mechanism of load reduction during walking was considered inefficient because of the activation delay of the vastus lateralis and tibialis anterior. We have concluded that the peripheral diabetic neuropathy damages not only somatosensorial and motor sources but also intrinsic mechanisms of motor control leading to alterations in the ankle efficiency in gait. This resulting distal inefficiency compromises some of the principal requirements for gait, such as progression and balance. RELEVANCE: This investigation is based on an innovating thematic approach involving the diabetic peripheral neuropathy. This innovation concerns the use of EMG and an instrumented treadmill in a clinical application to study and interpret the motor control during gait in neuropathic diabetic patients.

Analise biomecanica da locomocao de individuos com e sem lesao no ligamento cruzado anterior: um estudo de caso / Biomechanics parameters for the analysis of locomotion pattern in subject presenting Anterior Cruciate Ligament injury

A lesao do Ligamento Cruzado Anterior(LCA) influencia os mecanismo funcionais da articulacao do joelho,por intermedio de processos adaptativos ainda nao muito claros. O objetivo do presente estudo foi identificar as alteracoes biomecanicas da locomocao devido a lesao do LCA em um estudo de caso. Foram analisadas a atividade eletrica dos musculos vasto lateral, vasto medial e biceps da coxa, a forca de reacao do solo, a variacao angular e o momento de forca da articulacao do joelho durante a fase de apoio do andar. Foram estudados um sujeito com lesao do LCA e um sujeito sem nenhuma difusao musculo-esqueletica. Os resultados indicam a presenca de mecanismo compensatorios de reducao do momento de forca interno extensor no inicio da fase de apoio do andar, que corrobora com o aumento da atividade eletromiografica do musculo biceps da coxa nessa fase

On the inter- and intra-subject variability of the electromyographic signal in isometric contractions.

The objective of the present study was to evaluate the variability of the surface EMG signal of the same muscle in healthy subjects, because of lack of reproducibility of the EMG signal for the same subject and muscle in different trials of maximal isometric voluntary contraction. The results showed an EMG coefficient of variability of 21.61%, indicating that this variability must be considered in experiments with an inappropriate condition for normalization procedures, such as EMG biofeedback in rehabilitation sessions, or normalization procedures by the maximal isometric voluntary contraction.

Comparative study of Mm. Multifidi in lumbar and thoracic spine.

Imbalance of Mm. Multifidi may play a role in spinal disorders such as scoliosis in the thoracic spine, and lumbar disc herniation and lower back pain in the lumbar spine. Even though changes in these muscles are related to the etiology of these disorders, their anatomy is still poorly understood, especially in the upper regions of the spine. With the aim of gaining a better understanding of the anatomy of Mm. Multifidi in the lumbar and thoracic spine, 12 fresh and two embalmed cadavers were dissected. Our results indicate that Mm. Multifidi present differences in lumbar and thoracic spines concerning their deepness, fibre trajectory, muscle length, muscle mass and tendinous tissue. In the lumbar spine Mm. Multifidi are a superficial, thick and fleshy mass, and their fibres are more vertical in relation to the spinous processes. In the thoracic spine Mm. Multifidi are deeper, thinner, and their fibres are more tendinous and oblique than in the lumbar spine. These differences have implications on Mm. Multifidi architecture and consequently for their function in these two regions of the spine.

A study of biomechanical parameters in gait analysis and sensitive cronaxie of diabetic neuropathic patients.

OBJECTIVE: The present investigation aims at studying the sensitive cronaxie in neuropathic and non-neuropathic diabetic patients as a measure of sensorial deficit. We seek to describe the gait using dynamic and temporal parameters. We have compared the results of the neuropathic patients to the results of a non-diabetic group. We have looked for relationships between peak plantar pressure and sensitive cronaxie in selected plantar areas. DESIGN AND METHODS: The experimental procedures were divided in: (a) determination of the sensitive cronaxie in four selected plantar areas, (b) determination and description of peak plantar pressure, ground reaction force variables and single and double stance time. We analyzed and compared the results of the sensitive cronaxie and the biomechanical parameters obtained by three experimental groups: diabetic, neuropathic and non-diabetic subjects. RESULTS: The pathological response of the sensitive cronaxie worsened progressively for neuropathic and diabetic patients, respectively. Longer double and single stance times, lower minimum vertical force and lower growth rates were seen in the neuropathic patients when compared to diabetic and non-diabetic subjects. CONCLUSIONS: These results indicate an alteration in the neuropathic patient movement structure. We have speculated that compensatory musculoskeletal mechanisms have been developed by neuropathic patients to compensate for their sensorial deficit. Future research is necessary to verify the relationship between neurophysiological and dynamic variables, since this relationship seems to be a good parameter for the interpretation and comprehension of the peripheral neuropathy. RelevancePeripheral neuropathy is one of the most insidious chronic complications of diabetes. It has been observed that dynamic changes in gait are usually associated with the peripheral neuropathy somatosensory deficits. Biomechanical studies have highlighted that dynamic gait evaluation can identify functional alterations, besides the analysis of sensitive cronaxie as a measure of sensorial deficits. They are also useful as a complimentary routine in the clinic treatment of diabetes and its further long-term complications.

Comportamento adaptativo de funçöes neuro-musculares e cinéticas selecionadas em diferentes tarefas locomotoras / Adaptative behavior of neuromuscular function and selected kinets in different locomotor methods

O movimento humano requer controle e coordenação simultâneos entre diversos segmentos corporais e, para tanto, o sistema motor elabora estratégias neuro-musculares e fiom de reduzir os graus de liberdade. Uma maneira de se investigar a flexibilidade e adaptabilidade do sistema motor e através do estudo biomecânico de padrões de movimentos submetidos a diferentes demandas ambientais. Assim, este estudo propõe-se a avaliar respostas eletromiográficas dos principais músculos locomotores, bem como a componente vertical da força reação do solo durante o andar no plano, subindo e descendo escadas em crianças. Através da análise do comportamento adaptativo destes parâmetros neuro-musculares e cinéticos, pode-se obter indicadores quantitativos e qualitativos da função coordenativa do sistema motor

Abstract - The human movement is dependent on the contrai of multiple coordinations and the motor system elaborates neuro-muscular strategies to reduce the degrees of freedom of multi-joint movements. A way to investigate the flexibility and adaptability characteristics of the motor system is through the biomechanical study of movement patterns submitted to different environmental constraints. The purpose of this study is to analyse the electromyographic activity of locomotor muscles and the vertical componente ofthe ground reaction force in children during levei and stair walking. Through the analysis of the adaptative behavior of these selected neuromuscular and kinetic parameters, it is possible to identify qualitative and quantitative indicators of the coordinative function ofthe human motor system