Sox6 impairs the adipogenic commitment of mesenchymal stem cells by targeting lysyl oxidase and preadipocyte factor 1.

The commitment of mesenchymal stem cells (MSCs) to preadipocytes and the termination of differentiation to adipocytes are critical for maintaining systemic energy homeostasis. However, our knowledge of the molecular mechanisms governing the commitment of MSCs to preadipocytes and the subsequent termination of their differentiation into adipocytes remain limited. Additionally, the role of Sox6 sex-determining region Y (SRY)-box6 (Sox6), a transcription factor that regulates gene transcription, is reportedly involved in various cellular processes, including adipogenesis; however, its function in regulating preadipocyte development and the factors involved in the termination of adipogenic differentiation remain unexplored.

Acute repetitive lumbar syndrome: a multi-component insight into the disorder.

Purpose: Repetitive Lumbar Injury (RLI) is common in individuals engaged in long term performance of repetitive occupational/sports activities with the spine. The triggering source of the disorder, tissues involved in the failure and biomechanical, neuromuscular, and biological processes active in the initiation and development of the disorder, are not known. The purpose is, therefore, to test, using in-vivo feline model and healthy human subjects, the hypothesis that RLI due to prolonged exposure to repetitive lumbar flexion-extension is triggered by an acute inflammation in the viscoelastic tissues and is characterized by lingering residual creep, pronounced changes in neuromuscular control and transient changes in lumbar stability.

Pro-inflammatory cytokines expression increases following low- and high-magnitude cyclic loading of lumbar ligaments.

Repetitive or overuse disorders of the lumbar spine affect the lives of workers and athletes. We hypothesize that repetitive anterior lumbar flexion-extension under low or high load will result in significantly elevated pro-inflammatory cytokines expression several hours post-activity. High loads will exhibit significantly higher expression than low loads.

Motor control of lumbar instability following exposure to various cyclic load magnitudes.

The motor control system may compensate for lumbar instability following cyclic work with differential response to load magnitude. In vivo felines were exposed to a cumulative 1 h of cyclic work at 0.25 Hz.

Neuromuscular control of lumbar instability following static work of various loads.

Neuromuscular control of lumbar stability following exposure to prolonged static work, under low and high loads, was assessed in the in vivo feline model. Six sessions of 10 min work at 20N with 10 min between rest was compared to a group subjected to the same protocol but carrying high loads of 60N. Displacement and tension developed in the spine at the instant the multifidus muscles applied stabilizing contractions, and their amplitudes were obtained from their electromyogram (EMG).

Neuromuscular neutral zones response to cyclic lumbar flexion.

The in vivo lumbar spine of the anaesthetized feline was subjected to passive cyclic anterior flexion-extension at 0.25 Hz and 40 N peak load for cumulative 60 min duration. Displacement (or displacement neuromuscular neutral zones-DNNZ) and tension (or tension neuromuscular neutral zones-TNNZ) at which reflexive EMG activity from the multifidi muscles was initiated and terminated were recorded, for single-test cycles, before and for 7h after cyclic loading.

Power spectra characteristics associated with static reflexive activation of the multifidus muscle in feline models.

The aim of the study was to track changes in the spectrum of electromyographic (EMG) signals recorded from the feline multifidus muscles during stretching of the supraspinous ligament. The ligaments were exposed to external 40 N-tension for six consecutive trials of 10-min duration. Two experimental groups were formed, according to the rest periods supplied (10 or 20 min).

Neuromuscular neutral zones response to static lumbar flexion: muscular stability compensator.

Background: The impact of six sequential static loading and rest of the lumbar spine on the changes in the neuromuscular neutral zones and thereby on spine stability was assessed.

Methods: Six 10 min sessions of static load of a moderate level each spaced by 10 min rest were applied to the in vivo feline model. Test cycles of 0.

Short rest between cyclic flexion periods is a risk factor for a lumbar disorder.

Background: The epidemiology identifies cyclic lumbar loading as a risk factor for cumulative trauma disorder. Experimental biomechanical and physiological confirmation is lacking. The objective of this study was to asses the impact of different rest durations applied between periods of cyclic loading on the development of an acute lumbar disorder which, if continued to be subjected to loading, may develop into a cumulative disorder.

Cyclic load magnitude is a risk factor for a cumulative lower back disorder.

Objective: Epidemiological data suggest that high loads lifted by workers engaged in static and cyclic daily activities may be a risk factor for low back disorder. Our previous research provided physiological and biomechanical validation of the epidemiological data for static load conditions. The objective of this report was to provide physiological and biomechanical experimental validation to the epidemiological data in cyclic (repetitive) load conditions.

High-repetition cyclic loading is a risk factor for a lumbar disorder.

Epidemiological data suggest that prolonged exposure to cyclic lumbar flexion elicits a chronic neuromuscular disorder and disability in workers. This study provides a physiological and biomechanical assessment of various repetitions of cyclic lumbar flexion sessions as a risk factor for development of an acute neuromuscular disorder. An in vivo feline model was subjected to 10 minutes of cyclic (0.

Work to rest durations ratios exceeding unity are a risk factor for low back disorder; a feline model.

Low back disorders are prominent among the work force engaged in static anterior flexion during the workday. As a continuing part of a long-term research aimed to identify the biomechanical and physiological processes and corresponding risk factors leading to such cumulative trauma disorder (CTD), we ventured to assess the effect of rest and the work-to-rest duration ratios that may prevent CTD. Three groups of the feline model were subjected to three load/rest paradigms: two 30 min loading periods spaced by 10 min rest in Group I, two 30 min loading period spaced by 30 min rest in Group II and one 60 min loading period for Group III.

Neuromuscular response to cyclic loading of the anterior cruciate ligament.

Background: Cyclic load applied to various joints during occupational and sports activities is epidemiologically linked to higher risk of neuromuscular disorder development.

Hypothesis: Passive cyclic loading of the knee will develop laxity and creep in the anterior cruciate ligament, and these may elicit a neuromuscular disorder in the quadriceps and hamstrings. Women may be more susceptible to the disorder.

Short rest periods after static lumbar flexion are a risk factor for cumulative low back disorder.

The objective of this work was to study the effect of rest periods of various durations applied between six 10-min sessions of static flexion on the development of cumulative low back disorder (CLBD). Three experimental groups of a feline model were used, and the rest duration between sequential static load periods was set to 5, 10, and 20 min, with a corresponding load-to-rest ratio of 2:1, 1:1 and 1:2, respectively. The reflex electromyographic (EMG) activity from the multifidus muscles and supraspinous ligament displacement (creep) were recorded during the flexion periods and over 7 h of rest following the load-rest cycles.

Static load magnitude is a risk factor in the development of cumulative low back disorder.

Occupations requiring frequent periods of static lumbar flexion are known epidemiologically to be risk factors for the development of cumulative low back disorder. The impact of the load magnitude sustained during a series of short static lumbar flexions followed by an equally long rest period on the development of a cumulative low back disorder was addressed in an in vivo feline model. Static loads of 20, 40, and 60 N were applied over 10 min of flexion followed by 10-min rest sessions that were repeated six times (for a total of 2 h) while monitoring lumbar viscoelastic creep (laxity) and reflex electromyographic (EMG) activity from the multifidus muscles.

Longer static flexion duration elicits a neuromuscular disorder in the lumbar spine.

The objective of this study was to assess the impact of two sequential long, static, anterior lumbar flexions on the development of a neuromuscular disorder and to compare it with previously obtained data from a series of short static flexion periods of the same cumulative time (Sbriccoli P, Solomonow M, Zhou BH, Baratta RV, Lu Y, Zhu MP, and Burger EL, Muscle Nerve 29: 300-308, 2004). Static flexions with loads of 20, 40, and 60 N were applied to the lumbar spine over two 30-min periods with a 10-min rest in between. The reflex EMG activity from the multifidus muscles and supraspinous ligament displacement (creep) was recorded during the flexion periods.

Biomechanics and electromyography of a common idiopathic low back disorder.

Study Design: In vivo feline preparation groups loaded into lumbar flexion at different magnitudes and an unloaded control group.

Objective: To demonstrate that a static, constant load flexion of the lumbar spine results in a complex neuromuscular disorder.

Summary Of Background Data: Epidemiology suggests that static lumbar flexion is a cause of low back disorders.

Flexion-relaxation response to static lumbar flexion in males and females.

Objective: To determine if creep developed in the lumbar viscoelastic tissues during a period of static flexion elicited changes in the muscular responses of the flexion-relaxation phenomenon.

Background: Static lumbar flexion is a risk factor in workers, yet the physiological biomechanical and histological processes active in the evolution of the consequent low back disorder were not demonstrated experimentally. Controlled animal studies show that static lumbar flexion develops creep in the associated viscoelastic tissues and elicits spasms and modification of muscle function.

Neuromuscular dysfunction elicited by cyclic lumbar flexion.

An attempt was made to develop an in vivo model that could explain the neurophysiological and biomechanical processes active in the development of the idiopathic low back disorder common in workers who perform repetitive lifting tasks in industry. Passive cyclic flexion of the feline lumbar spine at 0.1 HZ for 20 min resulted in creep of the supraspinous ligament and other lumbar viscoelastic tissues as well as spasms superimposed on a decreasing electromyogram (EMG) elicited reflexly from the multifidus muscles.

Transients of the force and surface mechanomyogram during cat gastrocnemius tetanic stimulation.

The aim of the study was to investigate the time relationship between force and muscle surface displacement, detected as the surface mechanomyogram (MMG) by a laser distance sensor, in the transient phases of a tetanic stimulation. For this purpose the motor nerve of the exposed medial gastrocnemius of four cats was supramaximally stimulated at 30, 40 and 50 Hz for 9 s. Force was detected by a transducer connected at the distal tendon while MMG was measured after pointing the laser beam at the muscle belly.