Home About us Contact
|
Home About us Contact | ||
|
|
||
Muscle Tissue (muscle + tissue)
Kinds of Muscle Tissue Selected AbstractsAge Dependence of the Human Skeletal Muscle Stem Cell in Forming Muscle TissueARTIFICIAL ORGANS, Issue 3 2006Ralf Schäfer Abstract:, Human skeletal muscle stem cells from healthy donors aged 2,82 years (n = 13) and from three children suffering from Duchenne Muscular Dystrophy (DMD) were implanted into soleus muscles of immunoincompetent mice and were also expanded in vitro until senescence. Growth of implanted cells was quantified by structural features and by the amount of human DNA present in a muscle. Proliferative capacity in vitro and in vivo was inversely related to age of the donor. In vitro, a decline of about two mean population doublings (MPDs) per 10 years of donor's age was observed. Muscle stem cells from DMD children were prematurely aged. In general, cell preparations with low or decreasing content in desmin-positive cells produced more MPDs than age-matched high-desmin preparations and upon implantation more human DNA and more nonmyogenic than myogenic tissue. Thus, a "Desmin Factor" was derived which predicts "quality" of the human muscle tissue growing in vivo. This factor may serve as a prognostic tool. [source] Detection of ciguatoxin in fish tissue using sandwich ELISA and neuroblastoma cell bioassayJOURNAL OF CLINICAL LABORATORY ANALYSIS, Issue 4 2008Cara Empey Campora Abstract The applicability of a new enzyme-linked immunoassay (ELISA) for detecting ciguatoxin (CTX) in fish tissue was evaluated by testing three fish species commonly implicated in ciguatera fish poisoning in Hawaii. A total of 164 individual almaco jack (Seriola rivoliana) and greater amberjack (S. dumerili) and a total of 175 individuals of the blue-spotted grouper (Cephalopholis argus) were caught at various locations in the Hawaiian Islands. Muscle tissue from each individual was assessed for the presence of CTX using two methods: a semi-quantitative ELISA that was recently developed for detecting picogram levels of CTX in fish extract and a neuroblastoma (NB) cell assay commonly used to screen for marine toxins in fish. Results of the tests were highly correlated, with the ELISA indicating the presence of CTX in 9.4% of all fish samples, and the NB assay indicating toxicity in 6.8% of the fish samples. We conclude that the ELISA produces reliable and accurate results that are consistent with those provided by the accepted NB assay and that the ELISA has potential for future applications in screening fish populations for CTX. J. Clin. Lab. Anal. 22:246,253, 2008. © 2008 Wiley-Liss, Inc. [source] Early reattachment does not reverse atrophy and fat accumulation of the supraspinatus,an experimental study in rabbitsJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 3 2003Hans K. Uhthoff Abstract Introduction: Reattachment of the supraspinatus (SSP) tendon after spontaneous rupture leads to improved shoulder function. Whether this improvement of function is due to a reversal of muscle atrophy and fat accumulation known to occur after SSP rupture is still debated. Our previous study of late reattachment of SSP (12 weeks) failed to confirm a reversal of muscle atrophy and of fat accumulation. Purpose: To find out whether earlier reattachment (6 weeks) reverses atrophy and fat accumulation of the SSP. Material and methods: Reattachment group: in seven rabbits unilateral supraspinatus detachment, reattachment after 6 weeks and killing 6 weeks later. Detachment group: in seven rabbits unilateral supraspinatus detachment and killing 12 weeks later. The contralateral shoulders served as controls (n = 14). Determination of the supraspinatus constituents: muscle, extra- and intramuscular fat in volume and cross-sectional area. Results: Muscle tissue in the reattachment group (8.6 ml ± 1 s.d. = 0.6) and in the detachment group (8.9 ml ± 0.9) were less than in control supraspinati (10.2 ml ± 0.9, both p < 0.05). Extra- and intramuscular fat in the reattachment group (8.7% ± 3.2) was greater than in both, the detachment group (4.6% ± 3.5), and control supraspinati (2.8% ± 1.7, both p < 0.05). Conclusion: In the rabbit, reattachment of the SSP at 6 weeks did neither reverse muscle atrophy nor fat accumulation during the ensuing 6 weeks. However, earlier reattachment (6 weeks) when compared with later reattachment (12 weeks) prevented an increase in fat accumulation. On the other hand, the delay before reattaching the tendon did not lead to an increase in muscle atrophy. © 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved. [source] Linear alkylbenzenes in muscle tissues of white croaker near a large ocean outfall in southern California, USAENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 2 2001Charles R. Phillips Abstract Muscle tissues of a bottom-dwelling marine fish, white croaker (Genyonemus lineatus), collected near a large wastewater outfall in southern California, USA, were analyzed for long-chain linear alkylbenzenes (LABs). Total LABs (summed concentrations of C11 through C14 isomers) were highest (166,748 ng g,1 wet wt) in individuals collected in the immediate vicinity of the Orange County Sanitation District (OCSD; Fountain Valley, CA, USA) outfall diffuser, whereas relatively lower concentrations occurred in fish from mid-shelf and inshore locations at distances of 2.5 and 5 km, respectively, from the outfall. Fish tissue LAB concentrations were roughly proportional to sediment LAB concentrations at the respective collection sites. The extent of LAB degradation, as determined by ratios of internal to external C12 isomers, did not appear to relate to LAB concentrations or sampling location. Tissue DDT and PCB concentrations were not significantly correlated with LABs and, thus, did not appear to relate to recent exposures to sewage residues from the OCSD discharge. Measurements of LAB concentrations in fish tissues may be widely applicable as a monitoring tool for interpreting exposures to sewage discharges. [source] Oestrogen receptor , is expressed in adult human skeletal muscle both at the mRNA and protein levelACTA PHYSIOLOGICA, Issue 4 2003A. Wiik Abstract Aim:, There are two known oestrogen receptors (ER), oestrogen receptor , (ER,) and the recently cloned oestrogen receptor , (ER,). ER, mRNA has been detected in mouse, rat, bovine and human skeletal muscle. ER, mRNA has been detected in bovine skeletal muscle. To our knowledge, no study has investigated the expression of oestrogen receptor , in human skeletal muscle. Therefore, the primary aim of the present investigation was to study ER, mRNA and protein expression in human skeletal muscle. In addition the ER, expression was also studied. Methods:, Muscle biopsies were taken from vastus lateralis in six healthy adults (three women and three men). mRNA expression was detected with real-time PCR (TaqMan) and protein localization by immunohistochemistry. Results:, A clear expression of ER, and ER, mRNA was seen in skeletal muscle in all subjects. The ER, mRNA expression was 180 fold higher compared with that of ER, mRNA. Immunohistochemistry demonstrated positive staining for ER,, but not for ER,, with localization to the nuclei of skeletal muscle fibres. On average, 70% of all nuclei were ER, -positive. Conclusion:, The present study shows for the first time ER, mRNA and protein expression in human skeletal muscle tissue in both males and females. [source] Expression and alternative splicing of N-RAP during mouse skeletal muscle development,CYTOSKELETON, Issue 12 2008Shajia Lu Abstract N-RAP alternative splicing and protein localization were studied in developing skeletal muscle tissue from pre- and postnatal mice and in fusing primary myotubes in culture. Messages encoding N-RAP-s and N-RAP-c, the predominant isoforms of N-RAP detected in adult skeletal muscle and heart, respectively, were present in a 5:1 ratio in skeletal muscle isolated from E16.5 embryos. N-RAP-s mRNA levels increased three-fold over the first 3 weeks of postnatal development, while N-RAP-c mRNA levels remained low. N-RAP alternative splicing during myotube differentiation in culture was similar to the pattern observed in embryonic and neonatal muscle, with N-RAP-s expression increasing and N-RAP-c mRNA levels remaining low. In both developing skeletal muscle and cultured myotubes, N-RAP protein was primarily associated with developing myofibrillar structures containing ,-actinin, but was not present in mature myofibrils. The results establish that N-RAP-s is the predominant spliced form of N-RAP present throughout skeletal muscle development. Cell Motil. Cytoskeleton 2008. Published 2008 Wiley-Liss, Inc. [source] Transient production of ,-smooth muscle actin by skeletal myoblasts during differentiation in culture and following intramuscular implantationCYTOSKELETON, Issue 4 2002Matthew L. Springer Abstract ,-smooth muscle actin (SMA) is typically not present in post-embryonic skeletal muscle myoblasts or skeletal muscle fibers. However, both primary myoblasts isolated from neonatal mouse muscle tissue, and C2C12, an established myoblast cell line, produced SMA in culture within hours of exposure to differentiation medium. The SMA appeared during the cells' initial elongation, persisted through differentiation and fusion into myotubes, remained abundant in early myotubes, and was occasionally observed in a striated pattern. SMA continued to be present during the initial appearance of sarcomeric actin, but disappeared shortly thereafter leaving only sarcomeric actin in contractile myotubes derived from primary myoblasts. Within one day after implantation of primary myoblasts into mouse skeletal muscle, SMA was observed in the myoblasts; but by 9 days post-implantation, no SMA was detectable in myoblasts or muscle fibers. Thus, both neonatal primary myoblasts and an established myoblast cell line appear to similarly reprise an embryonic developmental program during differentiation in culture as well as differentiation within adult mouse muscles. Cell Motil. Cytoskeleton 51:177,186, 2002. © 2002 Wiley-Liss, Inc. [source] Expression pattern of Popdc2 during mouse embryogenesis and in the adultDEVELOPMENTAL DYNAMICS, Issue 3 2008Alexander Froese Abstract The Popdc2 gene is a member of the Popeye domain containing gene family encoding membrane proteins with prominent expression in striated and smooth muscle tissue. After introducing a LacZ reporter gene into the Popdc2 locus, expression was studied during embryonic development and postnatal life. At embryonic day (E) 7.5, expression was present in cardiac and extraembryonic mesoderm. At E10.5, expression was found in heart, somites, and mesothelial cells lining the coelom. At E12.5, expression was present in the coelomic mesothelium, pericardial and myocardial layer of the heart, skeletal muscle, bladder, gut, and umbilical vessels. Postnatal expression was found in cardiac and skeletal muscle and in the smooth muscle layer of colon, rectum, and bladder. In the stomach, Popdc2 was exclusively present in the pyloric epithelium. In conclusion, Popdc2 is expressed in various muscle and nonmuscle cell types during embryonic development and in postnatal life. Developmental Dynamics 237:780,787, 2008. © 2008 Wiley-Liss, Inc. [source] Effects of lipid extraction on stable carbon and nitrogen isotope analyses of fish tissues: potential consequences for food web studiesECOLOGY OF FRESHWATER FISH, Issue 3 2004M. A. Sotiropoulos Abstract,,, We examined whether solvent-based lipid extractions, commonly used for stable isotope analysis (SIA) of biota, alters ,15N or ,13C values of fish muscle tissue or whole juvenile fish. Lipid extraction from muscle tissue led to only small (<1,) isotope shifts in ,13C and ,15N values. By contrast, ecologically significant shifts (+3.4, for ,13C and +2.8, for ,15N) were observed for whole juvenile fish. Sample variance was not affected by lipid extraction. For tissue-specific SIA, two sample aliquots may be required: a lipid-extracted aliquot for stable carbon isotope analysis when differing lipid content among tissues is a concern, and a nonextracted aliquot for ,15N determination. Whole organism SIA is not recommended because of the mix of tissues having different turnover times; for very small fish, we recommend that fish be eviscerated, decapitated, and skinned to minimise differences with samples of muscle tissue. Resumen 1. Cada vez con mayor frecuencia, los ecólogos de peces utilizan análisis de isótopos estables. Por ello, se hace cada vez más importante comprender las fuentes de variación, - debido a diferencias inherentes entre muestreos biológicos o como resultado de técnicas de procesamiento de muestreo - tanto como identificar estrategias para tratar tales fuentes. Examinamos si la extracción de lípidos basada en disolventes, comúnmente utilizada en análisis de isótopos de carbono estable, altera negativamente los valores de ,15N y ,13C de tejido muscular de tres peces de tamaño pequeño y de peces juveniles completos. 2. La extracción de lípidos de músculo de pez llevó a pequeños cambios isotópicos de + +0.4 a +1.0, y de +0.3 a +0.5, para ,13C y ,15N, respectivamente. Por el contrario, la extracción de lípidos de peces juveniles completos varió marcadamente en +3.4, para ,13C y +2.8, para ,15N - ambos cambios ecológicamente importantes. La varianza de los valores de muestreos de ,13C y de ,15N tanto para tejido muscular como para los peces completos no difirieron entre los muestreos de lípidos extraídos y muestreos sin tratamiento. 3. Nuestros resultados recomiendan el análisis de isótopos estables de tejidos específicos. Cuando ello no es posible o deseable, dos alícuotas de muestreo pueden ser requeridas: una alícuota de lípidos extraídos para el análisis de isótopos de carbono estable cuando la varianza de ,13C, debida a diferencias en el contenido de lípidos de diferentes tejidos, y una alícuota de no-extracción para determinaciones de ,15N. 4. Dada la mezcla de tejidos, el análisis de isótopos de un organismo completo no es recomendable , en el caso de peces muy pequeños, recomendamos que los peces sean eviscerados, decapitados, y despellejados para minimizar las diferencias de muestreos de tejido muscular. [source] An effective skeletal muscle prefractionation method to remove abundant structural proteins for optimized two-dimensional gel electrophoresisELECTROPHORESIS, Issue 11 2005Bradley Jarrold Abstract Proteomic analysis of biological samples in disease models or therapeutic intervention studies requires the ability to detect and identify biologically relevant proteins present in relatively low concentrations. The detection and analysis of these low-level proteins is hindered by the presence of a few proteins that are expressed in relatively high concentrations. In the case of muscle tissue, highly abundant structural proteins, such as actin, myosin, and tropomyosin, compromise the detection and analysis of more biologically relevant proteins. We have developed a practical protocol which exploits high-pH extraction to reduce or remove abundant structural proteins from skeletal muscle crude membrane preparations in a manner suitable for two dimensional gel electrophoresis. An initial whole-cell muscle lysate is generated by homogenization of powdered tissue in Tris-base. This lysate is subsequently partitioned into a supernatant and pellet containing the majority of structural proteins. Treatment of the pellet with high-pH conditions effectively releases structural proteins from membrane compartments which are then removed through ultracentrifugation. Mass spectrometric identification shows that the majority of protein spots reduced or removed by high-pH treatment were contractile proteins or contractile-related proteins. Removal of these proteins enabled successful detection and identification of minor proteins. Structural protein removal also results in significant improvement of gel quality and the ability to load higher amounts of total protein for the detection of lower abundant protein classes. [source] Speciation of arsenic compounds in fish and oyster tissues by capillary electrophoresis-inductively coupled plasma-mass spectrometryELECTROPHORESIS, Issue 7-8 2005Ching-Fen Yeh Abstract A capillary electrophoresis-inductively coupled plasma-mass spectrometric (CE-ICP-MS) method for the speciation of six arsenic compounds, namely arsenite [As(III)], arsenate [As(V)], monomethylarsonic acid, dimethylarsinic acid, arsenobetaine and arsenocholine is described. The separation has been achieved on a 70,cm length×75,µm,ID fused-silica capillary. The electrophoretic buffer used was 15,mM Tris (pH,9.0) containing 15,mM sodium dodecyl sulfate (SDS), while the applied voltage was set at +22,kV. The arsenic species in biological tissues were extracted into 80%,v/v methanol-water mixture, put in a closed centrifuge tube and kept in a water bath, using microwaves at 80°C for 3,min. The extraction efficiencies of individual arsenic species added to the sample at 0.5,µg As/g level were between 96% and 107%, except for As(III), for which it was 89% and 77% for oyster and fish samples, respectively. The detection limits of the species studied were in the range 0.3,0.5,ng As/mL. The procedure has been applied for the speciation analysis of two reference materials, namely dogfish muscle tissue (NRCC DORM-2) and oyster tissue (NIST SRM 1566a), and two real-world samples. [source] Investigation of histopathological and cytogenetic effects on Lepomis gibbosus (Pisces: Perciformes) in the Çine stream (Ayd,n/Turkey) with determination of water pollutionENVIRONMENTAL TOXICOLOGY, Issue 6 2005Yücel Ba, lu Koca Abstract Water quality and the distribution of some heavy metals in three different organs of Lepomis gibbosus from the Çine Stream were studied. Also, histopathological changes in gill, liver, and muscle tissue were examined at light microscopical level. Micronucleus (MN) formation in fish erytrocytes, as an indicator of chromosomal damage, has been increasingly used to detect the genotoxic potential of environmental contaminants. The frequency of MN was examined from samples of fish from the Çine Stream and a control group. MN frequency was higher in fish samples caught from the Çine Stream than that in the control group. The chemicals ammonia, nitrite, nitrate, orthophosphate, and sulphate were determined as parameters that possibly affect the gill, liver, and muscle morphology. Zn was the most accumulated metal in tissues as well as in water. Maximum metal accumulation occured in both liver and gills. For histopathological examinations, samples of gills, liver, and muscle tissues of L. gibbosus were studied by using light microscopy. In this study, a significant decrease in mean length of primary and secondary lamellae were observed. Moreover, cellular proliferation developed with secondary lamellae fusion, ballooning degenerations or club deformation of secondary lamellae, as well as distribution of necrotic, hyperplastic and clavate secondary lamellae. In the liver, altered staining, swollen and ruptured parenchymal cells, loss of cord structure, reduce of glycogen in hepatocytes, and vacuolar structure filled with cellular debris and many dark particles were seen. In muscle tissue, focal necrosis, cellular dissolution, and a decline or loss of striatation in muscle fibres were found. © 2005 Wiley Periodicals, Inc. Environ Toxicol 20: 560,571, 2005. [source] Genotoxicity in wood mice (Apodemus sylvaticus) along a pollution gradient: Exposure-, age-, and gender-related effectsENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 8 2006Jan Scheirs Abstract We investigated the effects of environmental pollution on genetic damage in wood mice (Apodemus sylvaticus) by means of the comet assay, with special attention to the role of age and gender as potential confounding variables. The present study was carried out at four sites along a pollution gradient in the vicinity of Antwerp (Belgium), with a nonferrous smelter as the main pollution source. We measured the concentration of heavy metals (Cd, Co, Cr, Cu, Fe, Mn, Pb, and Zn) in mouse liver and kidney and the concentration of organochlorine compounds (polychlorinated biphenyls and 1,1-dichloro-2,2-bis(p -chlorophenyl)ethylene) in mouse muscle tissue to assess individual exposure. Cadmium exposure was very high at the sites closest to the smelter, and exposure to this metal decreased with increasing distance from the smelter. Exposure to the other pollutants was low to moderate at the different sites. Genetic damage was higher in mice from populations in the vicinity of the nonferrous smelter compared with that in the control populations. A significant increase in genetic damage with age was observed at the most polluted sites, but not at the control sites. Genetic damage was higher in male mice than in female mice at the most polluted site, but not at the other areas. Yet, no obvious relationship was found between individual pollutant levels and individual genetic damage levels. We conclude that the comet assay can be used to compare genotoxicity at the population level if the confounding variables of gender and age are taken into account. However, its use for individual health risk assessment remains questionable. [source] Fatty acid composition in wild and cultivated pacu and pintado fishEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 2 2009Augusto Tanamati Abstract The fatty acid compositions of muscle tissue taken from wild strains of pintado (Pseudoplatystoma corruscans) and pacu (Piaractus mesopotamicus) fish, which were taken from the Brazilian Pantanal, were compared to the fatty acid compositions of tissue taken from two corresponding cultivated strains, which were fed commercial diets. The cultivated species possessed lipid contents of 12.2% (pacu) and 8.9% (pintado) while the wild species contained 7.9% (pacu) and 2.5% (pintado) lipids. Despite the high lipid contents of the cultivated pintado and pacu, the n -3 polyunsaturated fatty acid concentrations in muscle tissue were higher in wild pintado (224.9,mg/g flesh) and wild pacu (485.1,mg/g flesh) than in their respective cultivated strains (129.8 and 106.1,mg/g flesh, respectively). The n -6/n -3 ratios of pacu were 1.2 (wild) and 9.8 (cultivated), and those of pintado were 1.0 (wild) and 7.3 (cultivated). The fatty acid composition of pacu and pintado are strongly influenced by habitat and diet. [source] Supplemental dietary flaxseed oil affects both neutral and phospholipid fatty acids in cultured tilapiaEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 8 2008Nilson E. de Souza Abstract This work aimed to evaluate the neutral lipid (NL) and phospholipid (PL) classes in tilapia (Oreochromis niloticus) muscle tissue. Tilapias were raised in captivity for a period of 5,months with increasing levels (0, 1.25, 2.50, 3.75, and 5.00%) of flaxseed oil [source of ,-linolenic acid (LNA), 18:3n -3] in substitution for sunflower oil (control). The NL/PL ratio was 1.9, and 45,fatty acids were determined for both classes of lipid. The class totals of n -3 acids always increased in all treatments, while the totals for n -6 acids always decreased (p,<0.05). For a given level of flaxseed oil, the LNA contents were consistently higher, including EPA (20:5n -3) and DHA (22:6n -3). Arachidonic acid (20:4n -6) remained high in the PL but was reduced as levels of dietary flaxseed oil were increased. The n -6/n -3 ratios decreased significantly with the rise in flaxseed oil content in all treatments, and highly unsaturated fatty acid contents increased with the levels of flaxseed oil. Overall, the influence of flaxseed oil on the fatty acid composition in the contributing NL and PL classes was to increase n -3 PUFA, thus raising the nutritional value of this freshwater fish meat and, consequently, contributing to the health of consumers. [source] Charcot-Marie-Tooth neuropathy type 1A combined with Duchenne muscular dystrophyEUROPEAN JOURNAL OF NEUROLOGY, Issue 10 2007P. Vondracek We report a 24-year-old male with an unusual combination of two inherited neuromuscular disorders , Charcot-Marie-Tooth (CMT) disease type 1A and Duchenne muscular dystrophy (DMD). A phenotypic presentation of this patient included features of both these disorders. Nerve conduction studies revealed demyelinating peripheral neuropathy. Electromyography showed a profound myogenic pattern. The serum creatine kinase level was highly elevated. Muscle biopsy revealed a dystrophic picture with deficient dystrophin immunostaining. CMT1A duplication on chromosome 17p11.2 was found. The frame-shift mutation c.3609,3612delTAAAinsCTT (p.K1204LfsX11) was detected in the dystrophin gene by analysing mRNA isolated from the muscle tissue. The patient inherited both these mutations from his mother. The combination of CMT1A and DMD has not been reported as yet. [source] Cell surface nucleolin on developing muscle is a potential ligand for the axonal receptor protein tyrosine phosphatase-,FEBS JOURNAL, Issue 20 2006Daniel E. Alete Reversible tyrosine phosphorylation, catalyzed by receptor tyrosine kinases and receptor tyrosine phosphatases, plays an essential part in cell signaling during axonal development. Receptor protein tyrosine phosphatase-, has been implicated in the growth, guidance and repair of retinal axons. This phosphatase has also been implicated in motor axon growth and innervation. Insect orthologs of receptor protein tyrosine phosphatase-, are also implicated in the recognition of muscle target cells. A potential extracellular ligand for vertebrate receptor protein tyrosine phosphatase-, has been previously localized in developing skeletal muscle. The identity of this muscle ligand is currently unknown, but it appears to be unrelated to the heparan sulfate ligands of receptor protein tyrosine phosphatase-,. In this study, we have used affinity chromatography and tandem MS to identify nucleolin as a binding partner for receptor protein tyrosine phosphatase-, in skeletal muscle tissue. Nucleolin, both from tissue lysates and in purified form, binds to receptor protein tyrosine phosphatase-, ectodomains. Its expression pattern also overlaps with that of the receptor protein tyrosine phosphatase-,-binding partner previously localized in muscle, and nucleolin can also be found in retinal basement membranes. We demonstrate that a significant amount of muscle-associated nucleolin is present on the cell surface of developing myotubes, and that two nucleolin-binding components, lactoferrin and the HB-19 peptide, can block the interaction of receptor protein tyrosine phosphatase-, ectodomains with muscle and retinal basement membranes in tissue sections. These data suggest that muscle cell surface-associated nucleolin represents at least part of the muscle binding site for axonal receptor protein tyrosine phosphatase-, and that nucleolin may also be a necessary component of basement membrane binding sites of receptor protein tyrosine phosphatase-,. [source] Reach-scale geomorphology affects organic matter and consumer ,13C in a forested Piedmont streamFRESHWATER BIOLOGY, Issue 6 2007D. M. WALTERS Summary 1. We investigated the spatial (longitudinal position and reach geomorphology) and seasonal (spring and autumn) influences on the variation of ,13C among organic matter sources and consumers in a forested Piedmont river, South Carolina, U.S.A. 2. Six sites were sampled along a continuum and varied in basin area from approximately 30 to 300 km2. Sites fell into two geomorphic categories (i) high-gradient, rock bed (,rock') or (ii) low-gradient, sand bed (,sand') sites. 3. Variation in ,13C was more strongly related to reach geomorphology than longitudinal position. ,13C of biofilm and consumers was consistently enriched at rock sites. Leaf litter (i.e. coarse particulate organic matter, CPOM) ,13C did not vary with bed type. There was significant ,13C enrichment at rock sites for biofilm, seston, fine benthic organic matter (FBOM), and eight of nine consumer trophic guilds (e.g. grazing invertebrates, insectivorous fishes). ,13C of biofilm and four trophic guilds was also positively correlated with drainage area, but the magnitude of enrichment was less than between bed types. 4. ,13C was generally enriched in spring, but this varied among organic matter types, consumers, and by bed type. CPOM and seston were enriched in spring, FBOM was enriched in autumn, and biofilm showed no trend. Five consumer guilds were enriched in spring, and only one fish guild, generalised carnivores, showed enrichment of muscle tissue in autumn. 5. Consumer ,13C enrichment at rock sites suggests greater reliance on algal carbon than for consumers at sand sites, but we also found ,13C enrichment of biofilm at rock sites. Thus, differences in consumer ,13C between bed types could be related to (i) increased consumption of biofilm at rock compared with sand sites, or (ii) consumption of biofilm at rock sites that is enriched relative to biofilm at sand sites or (iii) both mechanisms. 6. ,13C signatures in local food webs appear to respond to processes operating at multiple spatial scales. Overall downstream enrichment of biofilm and consumers was disrupted by strong local effects related to bed morphology. These results suggest that human alteration of channel habitat will have corresponding effects on stream food webs, as assessed by changes in ,13C. [source] Wet-Spun Biodegradable Fibers on Conducting Platforms: Novel Architectures for Muscle RegenerationADVANCED FUNCTIONAL MATERIALS, Issue 21 2009Joselito M. Razal Abstract Novel biosynthetic platforms supporting ex vivo growth of partially differentiated muscle cells in an aligned linear orientation that is consistent with the structural requirements of muscle tissue are described. These platforms consist of biodegradable polymer fibers spatially aligned on a conducting polymer substrate. Long multinucleated myotubes are formed from differentiation of adherent myoblasts, which align longitudinally to the fiber axis to form linear cell-seeded biosynthetic fiber constructs. The biodegradable polymer fibers bearing undifferentiated myoblasts can be detached from the substrate following culture. The ability to remove the muscle cell-seeded polymer fibers when required provides the means to use the biodegradable fibers as linear muscle-seeded scaffold components suitable for in vivo implantation into muscle. These fibers are shown to promote differentiation of muscle cells in a highly organized linear unbranched format in vitro and thereby potentially facilitate more stable integration into recipient tissue, providing structural support and mechanical protection for the donor cells. In addition, the conducting substrate on which the fibers are placed provides the potential to develop electrical stimulation paradigms for optimizing the ex vivo growth and synchronization of muscle cells on the biodegradable fibers prior to implantation into diseased or damaged muscle tissue. [source] Histological evaluation of the osteoinduction capability of human dentineINTERNATIONAL ENDODONTIC JOURNAL, Issue 11 2006M. E. L. Machado Abstract Aim, To assess whether human dentine has the potential to promote the development of calcified tissues when implanted in the muscle tissue of mice. Methodology, Root canals in extracted human teeth were instrumented to produce dentine fragments. The dentine fragments produced were divided into two. In group 1, fragments were demineralized and sterilized. In group 2, the fragments were not submitted to any additional treatment. The dentine fragments were then implanted in the muscle of mice. In group 3, the muscles were implanted with rehydrated lyophilized human bone powder. Animals were killed following test periods of 7, 15, 30, 60, 120 and 180 days, the fragments were removed together with adjacent muscle and examined under light microscopy to assess calcification. Results, Areas of calcification were observed in groups 1 and 3 after a period of 180 days. In group 2, the surrounding tissues displayed only chronic inflammatory infiltration. Conclusions, On the basis of the experimental model adopted in this study, fibroblast-rich connective tissue formed in groups 1 and 3, which could reflect an osteoinductive process. Further studies are suggested to identify which dentinal factors are capable of inducing the formation of a calcified matrix. [source] Concentration of copper, iron, manganese and zinc in muscle, fat and bone tissue of lambs of the breed German Merino Landsheep in the course of the growing period and different feeding intensitiesJOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 3-4 2007G. Bellof Summary A growth experiment with 108 lambs (breed German Merino Landsheep) was carried out in order to examine how gender, body weight and feeding intensity affect trace element concentrations in tissues and carcass. The lambs (50% male and 50% female) were fattened at three levels of feeding intensity (,low', ,medium' and ,high' by varying daily amounts of concentrate and hay) and slaughtered at different final body weights (30, 45 or 55 kg). Six male and six female animals were sacrificed at 18 kg live weight at the beginning of the comparative slaughter experiment. The left half carcass of each animal was divided into muscle tissue, fat tissue as well as bones and sinews and analysed for the trace elements copper (Cu), iron (Fe), manganese (Mn) as well as zinc (Zn). The body weight level influenced the Zn concentrations significantly in all tissues. In addition, the Fe concentration in the fat tissue was influenced by the body weight as well as the Cu content in the bone tissue. An influence due to gender could be seen for the Zn concentration in the muscle and fat tissue and for the Fe content in the fat and bone tissue as well as for the Cu concentration in the bones. The feeding intensity affected the Cu content in the muscle and bone tissue and also the Zn content in the muscle tissue. In the present study with lambs at body weight range from 18 to 55 kg on an average, 127 mg Fe, 87 mg Zn, 1.5 mg Cu as well as 1.1 mg Mn per kilogram dry matter were found in the bone tissue. In lamb muscle tissue combined from all parts (body weight range from 18 to 45 kg, both genders) the highest concentrations were for Zn and Fe [3.42 and 1.31 mg/100 g meat (wet weight basis)], while Cu remained far below these levels (0.08 mg/100 g meat and Mn was even below the detection limit of 0.025 mg/kg). Lamb muscle is a valuable source for highly available haem-Fe as well as for Zn and Cu in human nutrition. [source] Taurine concentrations in animal feed ingredients; cooking influences taurine contentJOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 7-8 2003A. R. Spitze Summary The aim of this study was to determine the taurine content in a variety of animal feeds. There is very little information on the taurine content of ingredients used in home-prepared diets for dogs and cats, and foods fed to wild animals in captivity. This study reports the taurine content of both common and alternative feed ingredients, and compares taurine loss as a result of different methods of food preparation. Foods were selected based on their use in commercial and home-prepared diets. Animal muscle tissue, particularly marine, contained high taurine concentrations. Plant products contained either low or undetectable amounts of taurine. The amount of taurine that remained in a feed ingredient after cooking depended upon the method of food preparation. When an ingredient was constantly surrounded by water during the cooking process, such as in boiling or basting, more taurine was lost. Food preparation methods that minimized water loss, such as baking or frying, had higher rates of taurine retention. [source] Changes in amino acid composition in the tissues of African catfish (Clarias gariepinus) as a consequence of dietary L-carnitine supplementsJOURNAL OF APPLIED ICHTHYOLOGY, Issue 3 2002R. O. A. Ozório A study was undertaken to examine the effect of different amounts of dietary lysine (13 and 21 g kg,1 diet), lipid (80 and 160 g kg,1 diet) and L -carnitine (0.2 and 1.0 g kg,1 diet) on growth performance, proximate composition and amino acid metabolism of the African catfish (Clarias gariepinus). Juvenile African catfish (23 ± 1.5 g/fish) were stocked into 70-L aquaria (16 aquaria, 28 fish/aquarium) connected to a recirculation system during a maximum period of 74 days. All groups were fed at a level of 24 g kg,0.8 day,1 in an experiment run at pair feeding. Animals receiving 1.0 g carnitine accumulated up to six times more carnitine in their tissues than animals receiving 0.2 g (P < 0.05). Acyl-carnitine and free L -carnitine levels increased in the whole body and in tissues. Dietary L -carnitine supplements increased protein-to-fat ratios in the body, but did not affect growth rate. Protein-to-fat ratios were only affected when the biosynthesis capacity of L -carnitine was restricted due to low lysine levels and when there was a shortage of dietary fat. When lysine was offered at 21 g kg,1 feed, dietary L -carnitine supplements did not affect the amino acid concentrations of body tissues. Dietary L -carnitine supplements raised the concentration of glutamic acid,>,aspartic acid,>,glycine > alanine > arginine > serine > threonine in skeletal muscle tissue (P < 0.05). Total amino acid concentration in muscle and liver tissues (dry-matter basis) increased from 506 to 564 and from 138 to 166 mg g,1, respectively, when diets were offered with high L -carnitine, low lysine and low fat levels. These data suggest that dietary L -carnitine supplementation may increase fatty acid oxidation and possibly decrease amino acid combustion for energy. [source] Computed tomographic measurements of thigh muscle cross-sectional area and attenuation coefficient predict hip fracture: The health, aging, and body composition studyJOURNAL OF BONE AND MINERAL RESEARCH, Issue 3 2010Thomas Lang Abstract Fatty infiltration of muscle, myosteatosis, increases with age and results in reduced muscle strength and function and increased fall risk. However, it is unknown if increased fatty infiltration of muscle predisposes to hip fracture. We measured the mean Hounsfield unit (HU) of the lean tissue within the midthigh muscle bundle (thigh muscle HU, an indicator of intramuscular fat), its cross-sectional area (CSA, a measure of muscle mass) by computed tomography (CT), bone mineral density (BMD) of the hip and total-body percent fat by dual X-ray absorptiometry (DXA), isokinetic leg extensor strength, and the Short Physical Performance Battery (SPPB) in 2941 white and black women and men aged 70 to 79 years. Sixty-three hip fractures were validated during 6.6 years of follow-up. Proportional hazards regression analysis was used to assess the relative risk (RR) of hip fracture across variations in thigh muscle attenuation, CSA, muscle strength, and physical function for hip fracture. In models adjusted by age, race, gender, body mass index, and percentage fat, decreased thigh muscle HU resulted in increased risk of hip fracture [RR/SD,=,1.58; 95% confidence interval (CI) 1.10,1.99], an association that continued to be significant after further adjustment for BMD. In models additionally adjusted by CSA, muscle strength, and SPPB score, decreased thigh muscle HU but none of the other muscle parameters continued to be associated with an increased risk of hip fracture (RR/SD,=,1.42; 95% CI 1.03,1.97). Decreased thigh muscle HU, a measure of fatty infiltration of muscle, is associated with increased risk of hip fracture and appears to account for the association between reduced muscle strength, physical performance, and muscle mass and risk of hip fracture. This characteristic captures a physical characteristic of muscle tissue that may have importance in hip fracture etiology. © 2010 American Society for Bone and Mineral Research [source] Vitamin D Receptor Expression in Human Muscle Tissue Decreases With Age,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 2 2004HA Bischoff-Ferrari Abstract Intracellular 1,25-dihydroxyvitamin D receptor (VDR) is expressed in human skeletal muscle tissue. However, it is unknown whether VDR expression in vivo is related to age or vitamin D status, or whether VDR expression differs between skeletal muscle groups. Introduction: We investigated these factors and their relation to 1,25-dihydroxyvitamin D receptor (VDR) expression in freshly removed human muscle tissue. Materials and Methods: We investigated biopsy specimens of the gluteus medius taken at surgery from 20 female patients undergoing total hip arthroplasty (mean age, 71.6 ± 14.5; 72% > 65 years) and biopsy specimens of the transversospinalis muscle taken at surgery from 12 female patients with spinal operations (mean age, 55.2 ± 19.6; 28% > 65 years). The specimens were obtained by immunohistological staining of the VDR using a monoclonal rat antibody to the VDR (Clone no. 9A7). Quantitative VDR expression (number of VDR positive nuclei) was assessed by counting 500 nuclei per specimen and person. Serum concentrations of 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D were assessed at day of admission to surgery. Results: All muscle biopsy specimens stained positive for VDR. In the univariate analyses, increased age was associated with decreased VDR expression (r = 0.5: p = 0.004), whereas there were no significant correlations between VDR expression and 25-hydroxyvitamin D or 1,25-dihydroxyvitamin D levels. VDR expression did not differ between patients with hip and spinal surgery. In the multivariate analysis, older age was a significant predictor of decreased VDR expression after controlling biopsy location (gluteus medius or the transversospinalis muscle), and 25-hydroxyvitamin D levels (linear regression analysis: ,-estimate = ,2.56; p = 0.047). Conclusions: Intranuclear immunostaining of the VDR was present in muscle biopsy specimens of all orthopedic patients. Older age was significantly associated with decreased VDR expression, independent of biopsy location and serum 25-hydroxyvitamin D levels. [source] Skeletal muscle tissue engineeringJOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 4 2004A. D. Bach Abstract The reconstruction of skeletal muscle tissue either lost by traumatic injury or tumor ablation or functional damage due to myopathies is hampered by the lack of availability of functional substitution of this native tissue. Until now, only few alternatives exist to provide functional restoration of damaged muscle tissues. Loss of muscle mass and their function can surgically managed in part using a variety of muscle transplantation or transposition techniques. These techniques represent a limited degree of success in attempts to restore the normal functioning, however they are not perfect solutions. A new alternative approach to addresssing difficult tissue reconstruction is to engineer new tissues. Although those tissue engineering techniques attempting regeneration of human tissues and organs have recently entered into clinical practice, the engineering of skletal muscle tissue ist still a scientific challenge. This article reviews some of the recent findings resulting from tissue engineering science related to the attempt of creation and regeneration of functional skeletal muscle tissue. [source] Sarcopenia is not due to lack of regenerative drive in senescent skeletal muscleAGING CELL, Issue 2 2005Erik Edström Summary Sarcopenia, loss of skeletal muscle mass, is a hallmark of aging commonly attributed to a decreased capacity to maintain muscle tissue in senescence, yet the mechanism behind the muscle wasting remains unresolved. To address these issues we have explored a rodent model of sarcopenia and age-related sensorimotor impairment, allowing us to discriminate between successfully and unsuccessfully aged cohort members. Immunohistochemistry and staining of cell nuclei revealed that senescent muscle has an increased density of cell nuclei, occurrence of aberrant fibers and fibers expressing embryonic myosin. Using real-time PCR we extend the findings of increased myogenic regulatory factor mRNA to show that very high levels are found in unsuccessfully aged cohort members. This pattern is also reflected in the number of embryonic myosin-positive fibers, which increase with the degree of sarcopenia. In addition, we confirm that there is no local down-regulation of IGF-I and IGF-IR mRNA in aged muscle tissue; on the contrary, the most sarcopenic individuals showed significantly higher local expression of IGF-I mRNA. Combined, our results show that the initial drive to regenerate myofibers is most marked in cases with the most advanced loss of muscle mass, a pattern that may have its origin in differences in the rate of tissue deterioration and/or that regenerating myofibers in these cases fail to mature into functional fibers. Importantly, the genetic background is a determinant of the pace of progression of sarcopenia. [source] White muscle 20S proteasome activity is negatively correlated to growth rate at low temperature in the spotted wolffish Anarhichas minorJOURNAL OF FISH BIOLOGY, Issue 7 2010S. G. Lamarre The effect of temperature and mass on specific growth rate (G) was examined in spotted wolffish Anarhichas minor of different size classes (ranging from 60 to 1500 g) acclimated at different temperatures (4, 8 and 12° C). The relationship between G and 20S proteasome activity in heart ventricle, liver and white muscle tissue was then assessed in fish acclimated at 4 and 12° C to determine if protein degradation via the proteasome pathway could be imposing a limitation on somatic growth. Cardiac 20S proteasome activity was not affected by acclimation temperature nor fish mass and had no correlation with G. Hepatic 20S proteasome activity was higher at 12° C but did not show any relationship with G. Partial correlation analysis showed that white muscle 20S proteasome activity was negatively correlated to G (partial Pearson's r = ,0·609) but only at cold acclimation temperature (4° C). It is suggested that acclimation to cold temperature involves compensation of the mitochondrial oxidative capacity which would in turn lead to increased production of oxidatively damaged proteins that are degraded by the proteasome pathway and ultimately negatively affects G at cold temperature. [source] Alternative migration and host parasitism strategies and their long-term stability in river lampreys from the River Endrick, ScotlandJOURNAL OF FISH BIOLOGY, Issue 10 2008C. E. Adams The stability of a discrete body size dimorphism of sexually mature river lamprey Lampetra fluviatilis from the River Endrick, Scotland, was examined over a 21 year period. Stable isotope analysis was used to test the hypothesis that the two size forms comprise individuals with differing migration and parasitic foraging strategies. Maturing river lamprey and the brook lamprey Lampetra planeri were trapped over 3 months each year in the periods 1983,1984 and 2004,2005. Brook lamprey catches and catches of both species combined showed no significant trend in catch rate with time. The catch rate of small body size river lamprey declined between 1983,1984 and 2004,2005 (although the difference did not reach statistical significance; P = 0·055). In contrast, there was a significant increase in the catch rate of the large body size river lamprey and as a consequence, a significant change in the relative proportion of each of the two river lamprey morphs over the study period. Analysis of the stable isotopes of C and N in muscle tissue showed that brook lamprey tissue derived its carbon from a freshwater source and had a ,13C more consistent with that of the River Endrick than with Loch Lomond. ,15N values for this species showed it to be feeding at the base of the food chain, consistent with filter feeding as an ammocoete. The large body size and the small body size river lamprey adults differed substantially in their ,13C values, with the small body size ,13C signature indicative of a freshwater carbon source and the large body size morph of a marine source. The small body size morph had a ,13C signature that was consistent with that of Loch Lomond powan Coregonus lavaretus suggesting that they share a common carbon source. The large body size morph was clearly feeding at a higher trophic level than the small body size morph. A single small body size river lamprey individual with typical morphology for that group, however, had C and N signatures that clustered with those of the large body size morphs. This individual had either migrated to sea to forage, as is typical for the species, or had been feeding on an anadromous fish with a strong marine C signature in fresh water. It is concluded that the body size dimorphism is indicative of a differential migration and foraging strategy in the parasitic phase of the life cycle of river lamprey at this site. [source] The effects of preservation on fish tissue stable isotope signaturesJOURNAL OF FISH BIOLOGY, Issue 6 2006B. Kelly The effects of formalin and ethanol preservation on the ,13C and ,15N isotope signatures of Arctic charr Salvelinus alpinus muscle tissue were examined. The lipid content of the tissue samples studied ranged from 3·6 to 6·1% and was not correlated with the magnitude of observed isotopic shifts in preserved samples. Ethanol and formalin significantly depleted and enriched, respectively, the ,13C isotope signatures of preserved tissues when compared to control samples. Ethanol did not significantly enrich ,15N signatures in comparison to controls, whereas formalin did. A meta-analysis of multiple species effects further demonstrated significant preservation effects in fish tissue. Statistical analysis of data obtained by correcting preserved tissue isotope signatures with literature, bootstrapped or meta-analysis derived correction factors demonstrated significant differences between corrected and control sample isotope signatures or failure to produce a unity slope when the data sets were regressed against one another. Species-specific, bootstrapped linear correction models resulted in no such errors. Results suggest that species-specific correction methods should be used for fishes because of the known wide variation in fish tissue lipid content and composition. Accordingly, the use of pilot studies will be required to develop correction factors that properly adjust for preservation effects when interpreting temporal patterns in historic analyses of food webs. [source] | |||||||||||||||||||||||||||||||