The purpose of the present study was to compare mRNA levels of myostatin (MSTN), myogenin (MyoG), and fiber type compositions in terms of myosin heavy chain (MyHC) in skeletal muscles of two rabbit breeds with different body sizes and growth rates. Longissimus dorsi and biceps femoris muscles of 16 Californian rabbits (CW) and 16 Germany great line of ZIKA rabbits (GZ) were collected at the ages of 35d and 84d (slaughter age). The results showed that the live weights of GZ rabbits of 35d and 84d old were approximately 36% and 26% greater than those of CW rabbits, respectively. Quantitative real-time PCR analysis revealed that at the age of 84d GZ rabbits contained significantly lower MSTN mRNA level and higher MyoG mRNA level in both longissimus dorsi and biceps femoris muscles than CW rabbits, and mRNA levels of MSTN and MyoG exhibited opposite changes from the age of 35d to 84d, suggesting that GZ rabbits were subjected to less growth inhibition from MSTN at slaughter age, which occurred most possibly in skeletal muscles. Four types of fiber were identified by real-time PCR in rabbit muscles, with MyHC-1 and MyHC-2D, MyHC-2B were the major types in biceps femoris and longissimus dorsi muscles, respectively. At the age of 84d, GZ rabbits contained greater proportion of MyHC-1 and decreased proportion of MyHC-2D and decreased lactate dehydrogenase activity in biceps femoris than CW rabbits, and the results were exactly opposite in longissimus dorsi, suggesting that GZ rabbits show higher oxidative capacity in biceps femoris muscle than CW rabbits. In conclusion, the trends of mRNA levels of MSTN and fiber types in GZ rabbits' skeletal muscles might be consistent with the putative fast growth characteristic of GZ rabbits compared to CW rabbits.
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http://dx.doi.org/10.1080/10495398.2013.865639 | DOI Listing |
Ultrasound Med Biol
January 2025
School and Graduate Institute of Physical Therapy, College of Medicine, National Taiwan University, Taipei, Taiwan ROC; Center of Physical Therapy, National Taiwan University Hospital, Taipei, Taiwan ROC. Electronic address:
Objective: This study aimed to validate the ultrasound speckle tracking (UST) algorithm, determine the optimal probe location by comparing normalized cross-correlation (NCC) values of muscle displacement at two locations (proximal vs. middle) of the biceps femoris long head (BFlh) using the UST, and investigate the effects of Nordic hamstring curl exercise (NHE) training on BFlh displacement.
Methods: UST efficacy was verified with ex vivo uniaxial testing of porcine leg muscles.
J Clin Med
January 2025
Department of Clinical Anatomy, Masovian Academy in Płock, 09-402 Płock, Poland.
Muscles and their tendons present a considerable diversity of morphological variations. The aim of this study was to explore variants of muscles and tendons from compartments of the thigh and to raise awareness about potential problems during ultrasound examination. This comprehensive review of the literature was created on the basis of scientific articles sourced from PubMed.
View Article and Find Full Text PDFJ Clin Med
January 2025
Department of Orthopaedic Surgery, Institute of Medicine, University of Tsukuba, Tsukuba 305-8575, Japan.
Preoperative muscle atrophy leads to persistent gait abnormalities in patients undergoing total hip arthroplasty (THA). Efficient motor learning of the gluteus medius is crucial for their recovery. In this study, a single-joint hybrid assistive limb (HAL) was developed to assist hip abduction.
View Article and Find Full Text PDFActa Ortop Mex
January 2025
Servicio de Traumatología y Ortopedia, Hospital Ángeles Lomas. Huixquilucan de Degollado, Estado de México. México.
Introduction: anterior cruciate ligament rupture has evolved to be one of the most common sports injuries with a remarkable increase in its incidence in the last two decades, with Return-To-Sport being a crucial approach in the choice of autologous graft for its surgical repair, the most commonly used being hamstring and quadriceps tendon graft.
Material And Methods: a prospective randomized study was performed with 32 patients divided into two groups, one for each type of graft, with 13 patients in each. They were evaluated before surgery, at 30, 180 and 360 days after the procedure using scales such as Lysholm, mCKRS and ACL-RSI, and their previous activity level was considered using the Tegner score.
Front Physiol
January 2025
Department of Orthopaedics, Sports Medical Research Group, Balgrist University Hospital, University of Zurich, Zurich, Switzerland.
Competitive alpine skiing requires a high level of physical fitness to perform sport-specific manoeuvres and to minimise the risk of injury. The aim of this study was to establish reference values for the maximal anatomical cross-sectional area (ACSA) of the individual hamstrings (HAM) and quadriceps (QUAD) muscles as well as for the maximal voluntary torque (MVT) during knee flexion (KF) and knee extension (KE) of female and male elite competitive alpine skiers. Ultrasound and dynamometer data were obtained from a largely overlapping but not identical dataset.
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