Genetic characterization of Indubrasil cattle breed population.

Abstract The Indubrasil breed was developed in the Brazilian region called Triângulo Mineiro as a result of a cross between zebu cattle. Initially, it was used as a terminal cross and currently it represents approximately 4.45% of all the Brazilian zebu cattle. Studies were conducted to estimate genetic parameters in the Indubrasil using pedigree information, however, until now, no study has been developed using large-scale genomic markers in this breed. Pedigree information are widely used to investigate population parameters; however, they can neglect some estimates when compared to the use of genomic markers. Therefore, the objective of this study was to investigate the population structure and the genetic diversity of Indubrasil cattle using a high-density Single Nucleotide Polymorphism (SNP) panel (Illumina BovineHD BeadChip 700k). Levels of genomic homozygosity were evaluated using three different approaches: Runs of homozygosity (FROH), % of homozygosis (FSNP), and inbreeding coefficient (Fx). Further, Runs of Homozygosity (ROH) segments conserved among the animals were investigated to identify possible regions associated with the breed characteristics. Our results indicate that even the Indubrasil breed having a small effective population size, the levels of homozygosity (FROH = 0.046) are still small. This was possibly caused by the cross conducted among different breeds for its development. It suggests no immediate risks associated with loss of genetic variation. This information might be used in breeding programs, for the breed conservation and for the expansion of the Indubrasil breed

Allenamento adattato in soggetti over 70: effetti sulla forza e sulla potenza muscolare degli arti inferiori

Aim: Purpose of the study was to detect any gain in the strength and power of the knee extensor muscles in a group of 23 elderly people after a training period of one year. Material and meyhod: The training program, held at a frequency of three weekly sessions, wad designed to provide strength and power training suitable for elderly people, exercises aimed to improve balance, coordination, gait and dynamic posture. It consisted of heating, aerobic work, strength work, flexibility, balance, stretching, strength-training exercises with machines and exercises using elastic bands. All the participants (10 males and 13 females over the age of 70 years, mean age 76.2 ± 3.7) were evaluated before (pre) and after (post) the completion of the training program carrying out two tests: a) maximum voluntary isometric contraction at 90° of extension (KE) of the extensor muscles of the knee joint; b) maximum power of the lower limbs (LP). Result: The maximum isometric force measured on the knee extensors (KE) has increased both in males and females. The same was observed regarding the power of the knee extensors (LP). Improvement in power (LP) was more significant in the female group (p = 0.0001, 0.0009) than in the male group (p = 0.0223, 0.0454). Conclusion: The results show that elderly subjects involved in a long term training at medium intensity ncrease the strength and power of the muscle groups involved; further studies could investigate if also qther qualities such as balance and coordination improve.Training programs like this could be then applied in order to enhance the general quality of life of eldery people

Ultrasound monitoring of patients with leg muscle atrophy

Background. So far, the description of muscle atrophy in humans has been mostly based on changes in anatomical cross-sectional area (ACSA) measured at specific sites along the muscle belly by imaging techniques. However, there is experimental evidence of regional differences in muscle atrophy and therefore changes in the internal architecture of the muscle could go undetected on the basis of ACSA calculations. Skeletal muscles can be divided into roughly two categories: parallel muscles, whose muscle fibres are parallel to the tendon attached to the bone and are therefore on the traction axis of the muscle, and pennated muscles, whose fibres are connected to the tendinous sheet with an angle defined as the 'pennation angle'. In a previous study, we demonstrated that muscle atrophy led to a decrease in pennation angle and fibre length. The present study aimed demonstrate that to ultrasound may represent a simple, disposable non-invasive method to be used in rehabilitation medicine to assess muscle atrophy and monitoring changes in muscle architecture after rehabilitation. Methods. Ten patients (6 males, 4 females, 21-41 yrs.) with unilateral muscle atrophy were admitted to this study. Maximum anatomical CSA of the gastrocnemius medians (GM) was determined with CT scans of both legs. GM muscle fiber pennation angle and fiber length were measured in both legs in the same region of maximum CSA by real-time ultrasound with a 7.5 MHz, 4 cm long, linear probe. Maximal voluntary and electrically evoked torque of the plantar flexor muscles were measured. The twitch interpolation technique was also used. The measurements were repeated after a one month rehabilitation period in all of subject. Results. The mean pre-rehabilitation CSA was 17.8 cm2 in the unaffected limb and 16.7 cm2 in the affected limb; the post-rehabilitation values were 19.8 cm2 in the unaffected limb and 18.2 cm2 in the affected limb. Mean pennation angles differed by 11% (25.5% in the unaffected limb and 22.8% in the affected limb, p<0.02) at pre-rehabilitation, while no significant differences were observed at post-rehabilitation. No changes in fiber length were observed at pre- and post-rehabilitation. Affected to unaffected differences in maximal voluntary strength varied from 32.4% at pre- rehabilitation to 9.6% at postrehabilitation. Conclusions. This study showed that US provides a simple non-invasive means of quantify muscle atrophy and monitoring changes following rehabilitation. Structural changes in CSA and pennation angle as monitored by US, and functional changes in muscle maximal strength provide an 'up to date' profile of the muscular architecture and performance capacity. US represents a sensitive-to-change method to evaluate the degree of muscle atrophy in rehabilitation patients

Effectiveness of a home-based strengthening program for elderly males in Italy. A preliminary study

Background and aims: The practice of regular physical exercise has been shown to be effective in slowing the age-related progressive functional deterioration. Most exercise trials have been conducted with supervised training programs. The purpose of this study was to investigate the effectiveness of a 4-month home-based strength training on strength, function and personal satisfaction. Methods: Ten elderly men (mean age 68.5 years) were enrolled for home-based training one month after completing a 4-month supervised program; 12 age-matched men served as the control group. Subjects were asked to perform 3 sessions a week consisting of six resistance exercises with elastic bands involving the major muscle groups of the upper and lower limbs. We had calculated the correlation between the elongation and resistance of the elastic bands. The subjects were instructed to keep a diary reporting the execution of the session. We measured dynamic concentric strength of the muscle groups involved in the resistance exercises and maximal isometric strength of the knee extensors and elbow flexors before and after the 4-month home training. The Satisfaction Profile (SAT-P) questionnaire was administered before and one month after the completion of the training program for assessing personal satisfaction. Results: The final to baseline comparison showed a non-significant decrease in mean isometric maximal strength values for knee extensors and elbow flexors in the control group, while the exercise group significantly (p=0.001) improved the average baseline values. Maximal dynamic concentric strength values decreased significantly in the control group, while significant improvements were observed in the exercising subjects. The SAT-P questionnaire did not show any difference in either group from baseline. The adherence-to-protocol rate based on self-report was 78%. Conclusions: Home training with elastic bands appears to be an effective low-cost modality of maintaining strength and function in an elderly population