المؤلفون: Liju Yin, Zihao Wang, Shuai Mao, Zhenzhou Wang

المصدر: Journal of Medical Imaging and Health Informatics. 11:1517-1526

مصطلحات موضوعية: Eosin, Health Informatics, Anatomy, Haematoxylin, Biology, 030218 nuclear medicine & medical imaging, 03 medical and health sciences, chemistry.chemical_compound, 0302 clinical medicine, chemistry, Myocyte, Radiology, Nuclear Medicine and imaging, Segmentation, 030217 neurology & neurosurgery

الوصف: The effective detection of muscle cells, the accurate counting of their numbers and the analysis of their morphological features have great importance in biomedical research. At present, the quantification of muscle cell and the computation of their cross-sectional areas (CSA) are still manual or semi-automated, and with the increase of the image number, the manual or semi-automated methods might become intractable. Hence, the automatic methods are very desirable, which motivated the developments of many muscle cell segmentation methods. In this paper, three methods, SDDM, CELLSEGM and SMASH are compared and evaluated with 100 images with over 6000 cells. The Dices computed by SDDM, CELLSEGM and SMASH are 97.38%, 89.85% and 90.08% respectively. The average differences between the calculated cross-sectional areas and the ground truths by SDDM, CELLSEGM and SMASH are 5.14%, 10.76% and 7.97% respectively.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::90762456af8fdb0c719d7503b7cceb25Test
https://doi.org/10.1166/jmihi.2021.3449Test

المؤلفون: Sang Joon Lee, Chang Zoo Kim

المصدر: Strabismus. 28:201-207

مصطلحات موضوعية: Adult, Male, Adolescent, Satellite Cells, Skeletal Muscle, genetic structures, Muscle Fibers, Skeletal, Cell, Cell Count, Immunofluorescence, Young Adult, Proliferating Cell Nuclear Antigen, medicine, Humans, Myocyte, Child, Myosin Heavy Chains, medicine.diagnostic_test, biology, business.industry, Medial rectus muscle, PAX7 Transcription Factor, Anatomy, medicine.disease, biology.organism_classification, eye diseases, Muscle bundle, Ophthalmology, medicine.anatomical_structure, Microscopy, Fluorescence, Oculomotor Muscles, Child, Preschool, Exotropia, Female, Satellite (biology), sense organs, business, Intermittent exotropia

الوصف: To elucidate the differences in muscle bundle and satellite cells in medial rectus muscle through histological and Immunofluorescence studies of intermittent exotropia patients and normal controls....

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::48c624bf9d375c9f7dd6a5307c97e981Test
https://doi.org/10.1080/09273972.2020.1832546Test

المؤلفون: Thaís Garcia Santos, Patrícia Massara Martinelli, Fernando Pandolfo Bortolozzo, Stephen Tsoi, F. R. C. L. Almeida, Andreia D. Pereira, Michael K. Dyck, Fernando Felicioni, Walter T. Dixon, Thais Paula, Diogo Magnabosco, Andre L. Caldeira-Brant, Hélio Chiarini-Garcia, Erika Cristina Jorge

المصدر: J Anat

مصطلحات موضوعية: Male, 0301 basic medicine, medicine.medical_specialty, Histology, Swine, Muscle Fibers, Skeletal, Sus scrofa, Intrauterine growth restriction, Biology, Muscle Development, MyoD, Muscle hypertrophy, 03 medical and health sciences, 0302 clinical medicine, Pregnancy, Internal medicine, Myosin, medicine, Animals, Myocyte, Muscle, Skeletal, Molecular Biology, Ecology, Evolution, Behavior and Systematics, Fetal Growth Retardation, Myosin Heavy Chains, Myogenesis, Skeletal muscle, Original Articles, Cell Biology, medicine.disease, Phenotype, 030104 developmental biology, medicine.anatomical_structure, Endocrinology, Female, MYF5, Anatomy, 030217 neurology & neurosurgery, Developmental Biology

الوصف: Intrauterine growth restriction (IUGR) is a serious condition which impairs the achievement of the fetus' full growth potential and occurs in a natural and severe manner in pigs as a result of placental insufficiency. Reduced skeletal muscle mass in the fetus with IUGR persists into adulthood and may contribute to increased metabolic disease risk. To investigate skeletal muscle postnatal development, histomorphometrical patterns of the semitendinosus muscle, myosin heavy chain (MyHC; embryonic I, IIA, IIB and IIX isoforms) fiber composition and the relative expression of genes related to myogenesis, adipogenesis and growth during three specific periods: postnatal myogenesis (newborn to 100 days old), hypertrophy (100–150 days old), and postnatal development (newborn to 150 days old) were evaluated in female pigs with IUGR and normal birth weight (NW) female littermates. NW females presented higher body weights compared to their IUGR counterparts at all ages evaluated (P

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::b48856671b4986d626bc2850bcfe62f6Test
https://doi.org/10.1111/joa.13152Test

المؤلفون: Toshiharu Yamamoto, Hirohumi Suzuki

المصدر: The Journal of Veterinary Medical Science

مصطلحات موضوعية: Male, endocrine system, medicine.medical_specialty, Chemokine, Glucose uptake, gecko, Biology, pituitary, Internal medicine, medicine, Animals, Myocyte, CXCL14, Full Paper, General Veterinary, Pancreatic islets, Lizards, Pars intermedia, Immunohistochemistry, Prolactin, reptile, Endocrinology, medicine.anatomical_structure, alpha-MSH, Pituitary Gland, biology.protein, Female, Anatomy, Chemokines, CXC, hormones, hormone substitutes, and hormone antagonists, Hormone

الوصف: The distribution pattern of chemokine CXCL14-immunoreactive cells was examined by immunohistochemistry in the pituitary of the gecko Hemidactylus platyurus. Immunoreactive cells were observed in the pars intermedia and pars distalis of the pituitary, but not in the pars nervosa. All α-melanocyte-stimulating hormone (αMSH)-producing cells were immunoreactive for CXCL14 in the pars intermedia. The CXCL14-immunoreactive cells corresponded to prolactin (PRL)-producing cells but not to other adenohypophyseal-hormone-producing cells in the pars distalis. CXCL14 secreted from αMSH-producing cells and PRL-producing cells may regulate insulin release from β cells in the pancreatic islets as well as glucose uptake in the muscle cells together with αMSH and/or PRL. In addition, secreted CXCL14 with αMSH and/or PRL may act as a bioactive factor regulating hormone release in the adenohypophyseal cells of the reptilian pars distalis.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::c4b034456b630c396fe449312df994ebTest
https://doi.org/10.1292/jvms.19-0567Test

المؤلفون: Rachel B. Kueppers, Laura Johnson, Jolene C. Rudell, Linda K. McLoon, Erin Y Shen

المصدر: Investigative Ophthalmology & Visual Science

مصطلحات موضوعية: genetic structures, optokinetic nystagmus, Stimulation, Nystagmus, Biology, Extraocular muscles, MyoD, Nystagmus, Pathologic, Mice, medicine, Myocyte, Animals, MyoD Protein, Eye Movements, Strabismus, Amblyopia and Neuro-Ophthalmology, PITX2, Optokinetic reflex, Anatomy, musculoskeletal system, eye diseases, Disease Models, Animal, medicine.anatomical_structure, Gene Expression Regulation, Oculomotor Muscles, extraocular muscles, Reflex, sense organs, medicine.symptom, morphometry, Follow-Up Studies, nystagmus

الوصف: Purpose Myoblast determination protein 1 (MYOD) is a critical myogenic regulatory factor in muscle development, differentiation, myofiber repair, and regeneration. As the extraocular muscles significantly remodel their myofibers throughout life compared with limb skeletal muscles, we hypothesized that the absence of MYOD would result in their abnormal structure and function. To assess structural and functional changes in the extraocular muscles in MyoD-/- mice, fiber size and number and optokinetic nystagmus reflex (OKN) responses were examined. Methods OKN was measured in MyoD-/- mice and littermate wild-type controls at 3, 6, and 12 months. The extraocular muscles were examined histologically for changes in mean myofiber cross-sectional area, total myofiber number, and nuclei immunostained for PAX7 and PITX2, markers of myogenic precursor cells. Results The MyoD-/- mice developed nystagmus, with both jerk and pendular waveforms, in the absence and in the presence of moving visual stimulation. At 12 months, there were significant losses in mean myofiber cross-sectional area and in total number of orbital layer fibers in all rectus muscles, as well as in global layer fibers in the superior and inferior rectus muscles. Haploinsufficient mice showed abnormal OKN responses. PITX2-positive cell entry into myofibers of the MyoD-/- mice was significantly reduced. Conclusions This study is the first demonstration of the development of nystagmus in the constitutive absence of expression of the muscle-specific transcription factor MYOD. We hypothesize that myofiber loss over time may alter anterograde and/or retrograde communication between the motor nerves and extraocular muscles that are critical for maintaining normalcy of extraocular muscle function.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::f17b0f75d6569c4edfe274761fe1d71aTest
https://pubmed.ncbi.nlm.nih.gov/34617961Test

المؤلفون: Roland Assi, Alden B. Landry, George Tellides, Prashanth Vallabhajosyula, Nana Matsumoto, Chen Yang, Gilbert W. Moeckel, Guangxin Li, Jay D. Humphrey, Makoto Mori, Issam Dabe, Sameh Yousef, Shin-Rong Lee, Y. Kawamura, Arnar Geirsson

المصدر: Scientific Reports, Vol 11, Iss 1, Pp 1-13 (2021)
Scientific Reports

مصطلحات موضوعية: Male, Diseases, Cell Count, Pathogenesis, Comorbidity, 030204 cardiovascular system & hematology, Extracellular matrix, Aortic aneurysm, 0302 clinical medicine, Bicuspid Aortic Valve Disease, Myocyte, Single-Blind Method, 030212 general & internal medicine, Aorta, Multidisciplinary, biology, Anatomy, Middle Aged, Adaptation, Physiological, Extracellular Matrix, cardiovascular system, Medicine, Female, Structural biology, Tunica Media, Adult, Cell biology, Science, Myocytes, Smooth Muscle, Cardiology, Lumen (anatomy), Vascular Remodeling, Article, Mural cell, 03 medical and health sciences, Medical research, medicine, Humans, Aged, Aortic Aneurysm, Thoracic, Staining and Labeling, business.industry, Histology, medicine.disease, Elastin, biology.protein, business

الوصف: Medial degeneration is a common histopathological finding in aortopathy and is considered a mechanism for dilatation. We investigated if medial degeneration is specific for sporadic thoracic aortic aneurysms versus nondilated aortas. Specimens were graded by pathologists, blinded to the clinical diagnosis, according to consensus histopathological criteria. The extent of medial degeneration by qualitative (semi-quantitative) assessment was not specific for aneurysmal compared to nondilated aortas. In contrast, blinded quantitative assessment of elastin amount and medial cell number distinguished aortic aneurysms and referent specimens, albeit with marked overlap in results. Specifically, the medial fraction of elastin decreased from dilution rather than loss of protein as cross-sectional amount was maintained while the cross-sectional number, though not density, of smooth muscle cells increased in proportion to expansion of the media. Furthermore, elastic lamellae did not thin and interlamellar distance did not diminish as expected for lumen dilatation, implying a net gain of lamellar elastin and intralamellar cells or extracellular matrix during aneurysmal wall remodeling. These findings support the concepts that: (1) medial degeneration need not induce aortic aneurysms, (2) adaptive responses to altered mechanical stresses increase medial tissue, and (3) greater turnover, not loss, of mural cells and extracellular matrix associates with aortic dilatation.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::1adb7c54a668ff165d9da83ed010bffeTest
https://doi.org/10.1038/s41598-021-92659-1Test

المؤلفون: A. Kvochko, V. Spygova

المصدر: International bulletin of Veterinary Medicine. 4:135-139

مصطلحات موضوعية: Morphometrics, medicine.anatomical_structure, Age differences, Stomach, Ontogeny, medicine, Myocyte, Anatomy, Postnatal ontogenesis, Biology, Artery

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::899f45d619e180ef9237d9b4ff53c4adTest
https://doi.org/10.17238/issn2072-2419.2018.4.135Test

المؤلفون: Thorben Klamt, Stefan Kalies, Dominik Müller, Alexander Heisterkamp, Lara Gentemann

المصدر: PLoS ONE
PLoS ONE, Vol 16, Iss 6, p e0252346 (2021)

مصطلحات موضوعية: Force generation, Muscle Physiology, Physiology, Sarcomere, law.invention, Rats, Sprague-Dawley, Mathematical and Statistical Techniques, Myofibrils, law, Animal Cells, Image Processing, Computer-Assisted, Medicine and Health Sciences, Myocyte, Myocytes, Cardiac, Dewey Decimal Classification::500 | Naturwissenschaften, Cells, Cultured, Cardiomyocytes, Multidisciplinary, Fourier Analysis, Total Cell Counting, Cell Differentiation, Optical Equipment, Femtosecond, Physical Sciences, Medicine, Engineering and Technology, Cellular Types, Anatomy, Algorithms, Research Article, Muscle Contraction, Statistical Distributions, Sarcomere alignment, Sarcomeres, Cell Physiology, Micro damage, Science, Cell Enumeration Techniques, Muscle Tissue, Equipment, Biology, Research and Analysis Methods, Animals, Muscle Cells, Lasers, Biology and Life Sciences, Cell Biology, Laser, Probability Theory, Myocardial Contraction, Rats, Cell Metabolism, Biological Tissue, Biophysics, Dewey Decimal Classification::600 | Technik::610 | Medizin, Gesundheit, Entire cell, Mathematics

الوصف: Whereas it is evident that a well aligned and regular sarcomeric structure in cardiomyocytes is vital for heart function, considerably less is known about the contribution of individual elements to the mechanics of the entire cell. For instance, it is unclear whether altered Z-disc elements are the reason or the outcome of related cardiomyopathies. Therefore, it is crucial to gain more insight into this cellular organization. This study utilizes femtosecond laser-based nanosurgery to better understand sarcomeres and their repair upon damage. We investigated the influence of the extent and the location of the Z-disc damage. A single, three, five or ten Z-disc ablations were performed in neonatal rat cardiomyocytes. We employed image-based analysis using a self-written software together with different already published algorithms. We observed that cardiomyocyte survival associated with the damage extent, but not with the cell area or the total number of Z-discs per cell. The cell survival is independent of the damage position and can be compensated. However, the sarcomere alignment/orientation is changing over time after ablation. The contraction time is also independent of the extent of damage for the tested parameters. Additionally, we observed shortening rates between 6–7% of the initial sarcomere length in laser treated cardiomyocytes. This rate is an important indicator for force generation in myocytes. In conclusion, femtosecond laser-based nanosurgery together with image-based sarcomere tracking is a powerful tool to better understand the Z-disc complex and its force propagation function and role in cellular mechanisms.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::5e2e969f0e64393a534c3e2821e5c5f0Test
https://pubmed.ncbi.nlm.nih.gov/34086732Test

المؤلفون: Akiyoshi Uezumi, Kei Watanabe, Keitaro Minato, Madoka Ikemoto-Uezumi, Yuki Yoshimoto, Tamaki Kurosawa, Hiroyuki Kawashima

المصدر: International Journal of Molecular Sciences, Vol 22, Iss 12356, p 12356 (2021)
International Journal of Molecular Sciences

مصطلحات موضوعية: Male, Aging, lateral force transmission, QH301-705.5, Connective tissue, Catalysis, Dystrophin, Tendons, sarcopenia, Inorganic Chemistry, Extensor digitorum longus muscle, Mice, medicine, Animals, Myocyte, skeletal muscle, Biology (General), Physical and Theoretical Chemistry, Muscle, Skeletal, QD1-999, Molecular Biology, Spectroscopy, biology, Chemistry, Tension (physics), Communication, Organic Chemistry, Age Factors, Skeletal muscle, Muscle weakness, General Medicine, Anatomy, Biomechanical Phenomena, Computer Science Applications, Tendon, Mice, Inbred C57BL, Collagen Type III, Tenotomy, medicine.anatomical_structure, Gene Expression Regulation, biology.protein, medicine.symptom, Muscle Contraction, Myotomy

الوصف: The main function of skeletal muscles is to generate force. The force developed by myofiber contraction is transmitted to the tendon. There are two pathways of force transmission from myofibers to tendons: longitudinal transmission that depends on tension elicited via the myotendinous junction and lateral transmission that depends on shear elicited via the interface between the myofiber surface and surrounding connective tissue. Experiments using animal muscle and mathematical models indicated that lateral transmission is the dominant pathway in muscle force transmission. Studies using rat muscle showed that the efficiency of lateral force transmission declines with age. Here, the lateral transmission of force was measured using the extensor digitorum longus muscle from young and old mice. Dependence on longitudinal transmission increased in the old muscle, and there was a trend for lower efficiency of lateral force transmission in the old muscle compared to the young muscle. There was a noticeable increase in the connective tissue volume in the old muscle; however, there was no significant change in the expression of dystrophin, a critical molecule for the link between the myofiber cytoskeleton and extracellular matrix. This study demonstrates the measurement of lateral force transmission in mouse muscles and that alteration in force transmission property may underlie age-related muscle weakness.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::6ced8b528e794c1d331f0d32bd3b1e39Test
https://doi.org/10.3390/ijms222212356Test

المؤلفون: Ivan Myhre Winje, Johannes Landskron, Leonardo A. Meza-Zepeda, Diana Domanska, Chengyi Sun, Kamilla Nygård, Kristian Gundersen, Einar Eftestøl, Douglas P. Millay, Mads Bengtsen

المصدر: PLoS Genetics
PLoS Genetics, Vol 17, Iss 11, p e1009907 (2021)
PLoS Genetics, Vol 17, Iss 11 (2021)

مصطلحات موضوعية: Cancer Research, Gene Expression, Cell Cycle Proteins, QH426-470, Autoantigens, Biochemistry, Epigenesis, Genetic, Mice, Medicine and Health Sciences, Myocyte, MEF2C, Musculoskeletal System, Genetics (clinical), Regulation of gene expression, Muscles, Gene Ontologies, Genomics, musculoskeletal system, Cell biology, Muscle Fibers, Slow-Twitch, medicine.anatomical_structure, Muscle Fibers, Fast-Twitch, Epigenetics, Anatomy, Glycolysis, Oxidation-Reduction, Research Article, Cell type, Muscle Tissue, Biology, Antibodies, DNA-binding proteins, Genetics, medicine, Animals, Humans, Gene Regulation, Enhancer, Molecular Biology, Transcription factor, Ecology, Evolution, Behavior and Systematics, Cell Nucleus, Muscle Cells, Biology and Life Sciences, Proteins, Computational Biology, Skeletal muscle, Soleus Muscles, Genome Analysis, Rats, Regulatory Proteins, Biological Tissue, Skeletal Muscles, Genetic Loci, Transcription Factors

الوصف: Muscle cells have different phenotypes adapted to different usage, and can be grossly divided into fast/glycolytic and slow/oxidative types. While most muscles contain a mixture of such fiber types, we aimed at providing a genome-wide analysis of the epigenetic landscape by ChIP-Seq in two muscle extremes, the fast/glycolytic extensor digitorum longus (EDL) and slow/oxidative soleus muscles. Muscle is a heterogeneous tissue where up to 60% of the nuclei can be of a different origin. Since cellular homogeneity is critical in epigenome-wide association studies we developed a new method for purifying skeletal muscle nuclei from whole tissue, based on the nuclear envelope protein Pericentriolar material 1 (PCM1) being a specific marker for myonuclei. Using antibody labelling and a magnetic-assisted sorting approach, we were able to sort out myonuclei with 95% purity in muscles from mice, rats and humans. The sorting eliminated influence from the other cell types in the tissue and improved the myo-specific signal. A genome-wide comparison of the epigenetic landscape in EDL and soleus reflected the differences in the functional properties of the two muscles, and revealed distinct regulatory programs involving distal enhancers, including a glycolytic super-enhancer in the EDL. The two muscles were also regulated by different sets of transcription factors; e.g. in soleus, binding sites for MEF2C, NFATC2 and PPARA were enriched, while in EDL MYOD1 and SIX1 binding sites were found to be overrepresented. In addition, more novel transcription factors for muscle regulation such as members of the MAF family, ZFX and ZBTB14 were identified.
Author summary Complex tissues like skeletal muscle contain a variety of cells which confound the analysis of each cell type when based on homogenates, thus only about half of the cell nuclei in muscles reside inside the muscle cells. We here describe a labelling and sorting technique that allowed us to study the epigenetic landscape in purified muscle cell nuclei leaving the other cell types out. Differences between a fast/glycolytic and a slow/oxidative muscle were studied. While all skeletal muscle fibers have a similar make up and basic function, they differ in their physiology and the way they are used. Thus, some fibers are fast contracting but fatigable, and are used for short lasting explosive tasks such as sprinting. Other fibers are slow and are used for more prolonged tasks such as standing or long distance running. Since fiber type correlate with metabolic profile these features can also be related to metabolic diseases. We here show that the epigenetic landscape differed in gene loci corresponding to the differences in functional properties, and revealed that the two types are enriched in different gene regulatory networks. Exercise can alter muscle phenotype, and the epigenetic landscape might be related to how plastic different properties are.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::6ffb02080717a18392f2007cceb91fb5Test
https://doi.org/10.1371/journal.pgen.1009907Test