Muscles Research Papers - Academia.edu (original) (raw)

The unc-22 gene is one of a set of genes identified using classical genetics that affect muscle structure and function in the free-living nematode Caenorhabditis elegans. Since cloning the unc-22 gene by transposon tagging, we have used... more

The unc-22 gene is one of a set of genes identified using classical genetics that affect muscle structure and function in the free-living nematode Caenorhabditis elegans. Since cloning the unc-22 gene by transposon tagging, we have used conventional techniques combined with a set of Tc1 transposon insertion alleles to characterize the gene and its products. The gene extends over more than 20 kb of genomic sequence and produces a transcript of approximately 14 kb. A polyclonal antibody raised against an Escherichia coli beta-galactosidase-unc-22 fusion protein recognizes a polypeptide in nematode extracts that is between 500,000 and 600,000 daltons and labels the muscle A-band in indirect immunofluorescent microscopy. The Tc1-induced alleles have been used at every stage to verify these conclusions. The Tc1 insertions are spread over much of the region that contributes to the mature transcript; in most alleles, Tc1 sequences are incorporated into a composite unc-22-Tc1 transcript. Th...

Background and objectives: The role of genetic components in expression of proteins involved in signaling pathways of fat and carbohydrate metabolism has been welldemonstrated. The aim of this study was to determine effects of high... more

Background and objectives: The role of genetic components in expression of proteins involved in signaling pathways of fat and carbohydrate metabolism has been welldemonstrated. The aim of this study was to determine effects of high intensity interval training (HIIT) on glucose, insulin, and insulin resistance levels as well as IRS1 expression in gastrocnemius muscle of obese Wistar rats. Methods: The study included 14 male, Wistar rats (aged 10 weeks) weighting 220 ± 20 g. Obesity was induced in all rats via exposure to a high-fat diet for six weeks. Then, the rats were randomly divided into a HIIT group (n=7) and a control group (n=7). The rats in the HIIT group performed treadmill running, five sessions a week, for eight weeks. Levels of fasting glucose, serum insulin, insulin resistance, and IRS1 expression in the gastrocnemius muscle of the rats were measured after the last training session. Data were analyzed by the independent t-test at statistical significance of 0.05. Results: The HIIT intervention significantly decreased fasting glucose compared with the control group (p<0.0001). It also resulted in a significant decrease in serum insulin levels and insulin resistance compared with the control group (p<0.0001). Moreover, the HIIT training significantly increased IRS1 expression (p=0.030) in the gastrocnemius muscle of rats. Conclusion: Based on the available evidence, the increase in insulin function and the decrease in insulin resistance can be attributed to increased IRS1 expression in the gastrocnemius muscle following HIIT training.

Responses in the external anal and urethral sphincters as well as in the bulbocavernosus muscle have been evoked by supramaximal electrical stimulation of the penis (or clitoris), perineum and the peri-anal region and recorded... more

Responses in the external anal and urethral sphincters as well as in the bulbocavernosus muscle have been evoked by supramaximal electrical stimulation of the penis (or clitoris), perineum and the peri-anal region and recorded electromyographically in 82 male subjects 5 to 73 years old and in nine female subjects 18 to 55 years old, who had no systemic diseases or demonstrable sacral nervous system lesion. On perineal stimulation (including the penis or clitoris) reflex responses with a typical latency of 33 ms and which exhibit no habituation were obtained in all muscles examined. Stimulation of the peri-anal region gave habituating reflex responses with a typical latency of 55 ms in all muscles examined. On perineal, and sometimes also peri-anal stimulation, stable short latency responses with typical latencies of 5 and 13 ms were recorded; both were considered to be direct responses. The different evoked muscle responses obtained by stimulation in the perineal and peri-anal regio...

1. The desensitization of the cholinergic receptor has been investigated at the frog neuromuscular junction. The agonist was either perfused or applied by ionophoresis.2. In all situations, desensitization develops in two phases: a fast... more

1. The desensitization of the cholinergic receptor has been investigated at the frog neuromuscular junction. The agonist was either perfused or applied by ionophoresis.2. In all situations, desensitization develops in two phases: a fast one, experimentally in the second range but likely to be briefer, and a slower one, which extends over tens of seconds.3. When the presence of the agonist is prolonged, desensitization approaches a steady state, estimated through the amplitude of a test response. In steady-state conditions, this amplitude depends upon the desensitizing agonist concentration. The dose-response curve for desensitization induced by carbachol (CCh) indicates that half of the receptors can be desensitized at room temperature in the presence of 2.3 mum-CCh. The shape of the curve suggests that one desensitized receptor can bind two CCh molecules.4. The recovery from desensitization, estimated with a repetitive test pulse, displays two exponential phases. The time constant ...

Polychlorobiphenyls (PCBs), hexachlorocyclohexanes (HCHs), hexachlorobenzene (HCB) and DDT were examined in the muscle of brown trout (Salmo trutta) from a high mountain lake located in the Pyrenees (Catalonia, Spain) that was used as a... more

Polychlorobiphenyls (PCBs), hexachlorocyclohexanes (HCHs), hexachlorobenzene (HCB) and DDT were examined in the muscle of brown trout (Salmo trutta) from a high mountain lake located in the Pyrenees (Catalonia, Spain) that was used as a model of these lacustrine environments. Results indicate that fish age is the main factor of variability among specimens in this population that is subjected to atmospheric inputs of the organochlorine compounds (OC). Increases of 2- and 20-fold between fish aged 1 year and 15 years old are found. The observed pattern cannot be explained in terms of fish size, condition factor, or muscle lipid content. Higher molecular weight compounds (higher lipophilicity) are better correlated with fish age than low molecular weight compounds. A transformation from 4,4′-DDT to 4,4′-DDE occurs in fish after ingestion; this results in amplified age-dependent signals, especially in male specimens. In contrast, PCB congener #180 has lower age dependence than the general OC group, which could be due to its high hydrophobicity (log Kow > 7). In any case, selective accumulation of hydrophobic compounds is already observed among younger fish (age, 1 year). Due to this effect, the relative OC composition does not reflect the main OC pollutants in the lake waters.

Abstract Abstract. The highly conserved basic helix-loop-helix transcription factor Hand plays a crucial role in cardiogenesis, limb formation and other developmental processes of vertebrates. Humans, mice and other higher vertebrates... more

Abstract Abstract. The highly conserved basic helix-loop-helix transcription factor Hand plays a crucial role in cardiogenesis, limb formation and other developmental processes of vertebrates. Humans, mice and other higher vertebrates have two related genes, dHand (also known as Hand2, Hed, Thing2) and eHand (also known as Hand1, Hxt, Thing1), whereas fish and Drosophila have only a single hand gene. We cloned Drosophila hand and studied the embryonic expression in detail by using various tissue-specific markers that allowed us to analyze the identity of hand-expressing cells. We found hand to be expressed in the entire heart, including all cardioblasts and pericardial cells, in the progenitors of the circular visceral muscles, the lymph gland and garland cells, and in a few cells in the CNS. The expression of Drosophila hand starts after the inductive activity of the early regulators in these tissues, e.g. Tinman and Bagpipe, suggesting a role of Hand in differentiation rather than in tissue determination. In many aspects the expression pattern of Drosophila hand resembles the patterns of its vertebrates orthologues, for instance in cardiac tissues. We assume that Hand proteins might play a highly conserved role throughout evolution. Electronic Supplementary Material is available if you access this article at http://dx.doi.org/10.1007/s00427-002-0268-6. On that page (frame on the left side), a link takes you directly to the supplementary material.

We describe a polarization sensitive spectral domain optical coherence tomography technique based on a single camera spectrometer that includes a multiplexed custom grating, camera lenses, and a high-speed three-line CCD camera. Two... more

We describe a polarization sensitive spectral domain optical coherence tomography technique based on a single camera spectrometer that includes a multiplexed custom grating, camera lenses, and a high-speed three-line CCD camera. Two orthogonally polarized beams could be separately taken by two lines of the camera as a result of vertically different incident angles. The system could provide the imaging capabilities of a full camera speed and increased measurable depth. The proposed optical coherence tomography system could make a distinction between the normal muscle and cancerous tissue from the chest of a DSred GFP mouse and the OCT images were compared with those of in vivo confocal microscopy.

The sinus tarsi syndrome is now a well-defined entity of foot pathology. Usually post-traumatic, it is characterised by pain over the lateral opening of the sinus tarsi and a feeling of instability of the ankle. We were able to define two... more

The sinus tarsi syndrome is now a well-defined entity of foot pathology. Usually post-traumatic, it is characterised by pain over the lateral opening of the sinus tarsi and a feeling of instability of the ankle. We were able to define two objective criteria for the syndrome: arthrography of the subtalar joint shows specific abnormalities and recording of the electromyographic function of the peronei demonstrates abnormalities during walking. Conservative treatment is successful in about two-thirds of the cases. In other cases a simple surgical procedure can cure or improve 90% of the patients. Le syndrome du sinus du tarse est une entité bien définie de la pathologie du pied. Le plus souvent post-traumatique, il se caractérise par une douleur à l'orifice externe du sinus du tarse et une instabilité de l'arrière-pied. Nous avons pu définir deux symptômes objectifs de ce syndrome parfois difficile à diagnostiquer: l'arthrographie de l'articulation sous-astragalienn...

Glycogen synthase (GS), a key enzyme in glycogen synthesis, is activated by the allosteric stimulator glucose-6-phosphate (G6P) and by dephosphorylation through inactivation of GS kinase-3 with insulin. The relative importance of these... more

Glycogen synthase (GS), a key enzyme in glycogen synthesis, is activated by the allosteric stimulator glucose-6-phosphate (G6P) and by dephosphorylation through inactivation of GS kinase-3 with insulin. The relative importance of these two regulatory mechanisms in controlling GS is not established, mainly due to the complex interplay between multiple phosphorylation sites and allosteric effectors. Here we identify a residue that plays an important role in the allosteric activation of GS by G6P. We generated knockin mice in which wild-type muscle GS was replaced by a mutant that could not be activated by G6P but could still be activated normally by dephosphorylation. We demonstrate that knockin mice expressing the G6P-insensitive mutant display an ∼80% reduced muscle glycogen synthesis by insulin and markedly reduced glycogen levels. Our study provides genetic evidence that allosteric activation of GS is the primary mechanism by which insulin promotes muscle glycogen accumulation in vivo.► A critical glucose-6-phosphate (G6P) action site on glycogen synthase (GS) identified ► A knockin mouse expressing G6P-insensitive mutant GS generated ► GS knockin mice display dramatically reduced ability to accumulate muscle glycogen ► Insulin promotes glycogen synthesis mainly via allosteric activation of GS by G6P

During lucid dreaming, a subject willed movements of his fingers, toes and feet, remembered tasks, and counted sensory stimuli. Dreamed speech was related to respiration. EMG activity corresponding to dreamed actions was greater in flexor... more

During lucid dreaming, a subject willed movements of his fingers, toes and feet, remembered tasks, and counted sensory stimuli. Dreamed speech was related to respiration. EMG activity corresponding to dreamed actions was greater in flexor than in extensor limb muscles and was never present in axial muscles.

The time of occurrence of eye, head, and arm movements directed at the same visual target was measured in five human subjects. The latency of activation of the corresponding neck and arm muscles was also measured. It appears that although... more

The time of occurrence of eye, head, and arm movements directed at the same visual target was measured in five human subjects. The latency of activation of the corresponding neck and arm muscles was also measured. It appears that although the overt movements are sequentially ordered (starting with the eye movement, then the head and finally the arm) the EMG discharges are synchronous with respect to the eye movement onset. In addition, eye movement latency appears definitely (though weakly) correlated with either neck or arm EMG latencies. Neck and arm EMG latencies are also mutually correlated. These results indicate a clustering of segmental motor programs for target oriented actions.

In this study, bioaccumulation of the heavy metals (Fe, Zn, Cd) in the liver, gill, gonad and muscle tissues of Dicentrarchus labrax, Mugil cephalus and Sparus aurata were investigated seasonally. amlık is the important fisheries lagoon... more

In this study, bioaccumulation of the heavy metals (Fe, Zn, Cd) in the liver, gill, gonad and muscle tissues of Dicentrarchus labrax, Mugil cephalus and Sparus aurata were investigated seasonally. amlık is the important fisheries lagoon located in The Iskenderun Bay, Mediterranean cost of Turkey. Due to heavy industrial and agricultural activities in the region, the bay has the polluted