Intermyofibrillar Spaces Research Articles

Artificial intelligence approaches to the volumetric quantification of glycogen granules in EM images of human tissue.

Skeletal muscle, the major processor of dietary glucose, stores it in myriad glycogen granules. Their numbers vary with cellular location and physiological and pathophysiological states. AI models were developed to derive granular glycogen content from electron-microscopic images of human muscle. Two UNet-type semantic segmentation models were built: "Locations" classified pixels as belonging to different regions in the cell; "Granules" identified pixels within granules. From their joint output, a pixel fraction pf was calculated for images from patients positive (MHS) or negative (MHN) to a test for malignant hyperthermia susceptibility. pf was used to derive vf, the volume fraction occupied by granules. The relationship vf (pf) was derived from a simulation of volumes ("baskets") containing virtual granules at realistic concentrations. The simulated granules had diameters matching the real ones, which were measured by adapting a utility devised for calcium sparks. Applying this relationship to the pf measured in images, vf was calculated for every region and patient, and from them a glycogen concentration. The intermyofibrillar spaces and the sarcomeric I band had the highest granular content. The measured glycogen concentration was low enough to allow for a substantial presence of non-granular glycogen. The MHS samples had an approximately threefold lower concentration (significant in a hierarchical test), consistent with earlier evidence of diminished glucose processing in MHS. The AI models and the approach to infer three-dimensional magnitudes from two-dimensional images should be adaptable to other tasks on a variety of images from patients and animal models and different disease conditions.

Effects of ultrasound-assisted marination on spent hen meats: Microstructure, textural and technological properties

The purpose of this study was to investigate the effects of ultrasound-assisted marination in distilled water, kiwi, and lemon juices on the water holding capacity, pH, color (L*, a*, b*), cooking loss, and textural and sensory qualities of spent hen breast meat. In addition, differential scanning calorimetry (DSC) and scanning electron microscopy (SEM) images of the meats were determined. When compared to the marination method used alone, the water-holding capacity and drip loss of the spent hen meat samples increased as a result of ultrasound-assisted marination (P < 0.05). When compared to the other samples, the group marinated in lemon juice with ultrasonic assistance had a lower cooking loss value (P < 0.01). The results showed that the samples marinated in lemon juice had the highest L* and b* values, however, the samples marinated in lemon juice with and without ultrasound assistance had the lowest a* values. In terms of textural characteristics, the sonication treatment further reduced the shear force, even if the marination with the lemon and kiwi juices only slightly reduced it as compared to the control. The samples marinated in lemon juice with sonication support exhibited the lowest hardness value. According to DSC, the ultrasound-assisted marination process decreased the thermal denaturation temperatures of meat proteins. In terms of the SEM analysis results, it was observed that the inter-myofibrillar spaces were more evident in the chicken breast meats that underwent ultrasound-assisted marination compared to the only marination groups.

Effect of packaging thickness and muscle type on ultrasound-assisted beef quality

High-intensity ultrasound (HIU) can modify muscle structure, leading to improvements in tenderness. However, factors such as packing type and muscle complexity may attenuate the acoustic cavitation. In this research, the effect of packing thickness (40.6–70 μm) on the quality of bovine Gluteus medius and Biceps femoris treated with HIU (37 kHz, 90 W/cm2, 40 min) was evaluated. The hardness of G. medius decreased significantly as the thickness of the packing bag decreased. The wide interfibrillar and intermyofibrillar spaces corroborated the tenderizing effect. These effects are related to damage of cell structure and changes in the collagen content (3.37 ± 0.1 µg/mL). In addition, the HIU decrease the variability in the water holding capacity of the muscle produced by the use of low thickness bags during storage. The trained sensory panel described the sonicated samples in 50.8 μm bags as less hard and juicier. Contrarily, in B. femoris no significant effects were reported in the variables evaluated. B. femoris is a white muscle, with a high amount of collagen (3.59 ± 0.1 µg/mL) and little intramuscular fat. Consequently, the effect of the HIU on muscle quality is associated with the composition of the muscle fibers and the thickness of the packing bag. HIU application is recommended to improve the quality of leg muscles whenever low-thickness bags (50.8 μm or less) are used.

Experimental androgen deficiency and associated structural changes in the muscle tissue of the external anal sphincter

Aim. We aimed to study the histological and ultramicroscopic structure of the striated muscle tissue of the external anal sphincter (EAS) of mature male rats under experimental androgen deficiency.Materials and methods. The study included 10 male laboratory rats aged 8 months, which were randomly divided into 2 groups of 5 each. The experimental group underwent bilateral orchiectomy to create testosterone deficiency. After 45 days, rats were sacrificed. We studied the concentration of testosterone in histological sections of EASs using light microscopy and ultramicroscopy. We also determined the diameter of muscle fibers and the thickness of endomysium, the area of muscle fibers, connective tissue, myofibrils and cytoplasm, identification of glycogen granules in the cytoplasm and intermyofibrillar space, as well as changes in mitochondria. Results. In the experimental group, on the 45th day after surgical castration, the testosterone level was 2.5 times lower than in the control group 2.69 (2.52; 2.73) nmol/l vs. 7.20 (6.83; 7.21) nmol/l, p = 0.008. Using morphometric analysis, we found that in the experimental group after surgical castration the diameter of the muscle fibers was statistically significantly smaller than in the control group: 6.56 (3.96; 7.24) µm vs. 9.52 (8.88; 10.44) µm, p &lt; 0.001, while the thickness of the endomysium in the experimental group was greater: 3.34 (3.11; 3.78) µm vs. 1.62 (1.51; 1.86) µm, p &lt; 0.0001. The ratio of muscle fiber area/connective tissue area was statistically significantly lower in the group after castration: 1.64 (1.50; 1.78) vs. 4.00 (3.17; 5.25), p &lt; 0.0001. The ratio of myofibril area/cytoplasmic area changed in the experimental group towards the predominance of cytoplasm 0.79 (0.67; 0.79) vs. 5.25 (5.25; 7.33), p &lt; 0.0001. With an increase in cytoplasmic volume, an increase in the number of glycogen granules was observed; pathological forms of mitochondria were identified: swelling, destruction of cristae and vacuolization of their matrix. Conclusion. Under conditions of testosterone deficiency, along with atrophic processes, compensatory and adaptive mechanisms are formed in the striated skeletal muscle tissue of the EAS, aimed at restoring its metabolic and functional organization

Insights into the molecular mechanism of muscle textural quality improvement treated by exercise using comparative transcriptome analysis on the hybrid (Erythroculter ilishaeformis ♀ × Ancherythroculter nigrocauda ♂)

In general, fish meat that is elastic and hard is preferred by consumers, but few methods have been identified for improving fillet quality. “Xianfeng No. 1”, a new hybrid of Erythroculter ilishaeformis (♀) × Ancherythroculter nigrocauda (♂), is an important species for aquaculture in China. A short-term exercise trial (12 days) was conducted, followed by texture and histomorphology analysis, to determine the influence of exercise on fillet hardness of this hybrid species. Furthermore, transcriptomic and bioinformatic analyses were carried out to better understand the molecular bases under the process of fillet quality formation. There are several novel findings in our study. First, exercise at a moderate velocity (1.2 body lengths per second) for 12 days can significantly increase the muscle texture (i.e., hardness and springiness) of this hybrid species. Second, the hematoxylin and eosin (H&E) staining of muscle sections indicated a decrease in myofiber diameter and increased myofiber density as the exercise duration increased. Third, a total of 2056, 2414, and 3366 differentially expressed genes (DEGs) were identified in the 4, 8, and 12 days treatment groups, respectively. Fourth, the DEGs were enriched in signaling pathways linked to muscle hardening (tight junction and hippo signaling pathways) and glucose metabolism (AMPK signaling pathways and glycolysis/gluconeogenesis). Genes associated with muscle hardening (WNT2B, CDH1, MYCB, MYH1, MYH2, and MYH6), immune defense (MAVS, EPO, and SKAP2), and glucose metabolism (HK1, GAPDH, LDHA, and PGK1) were also identified. From our study, there are several possible molecular bases on which exercise improves fillet hardness: exercise may activate hippo pathway to stimulate hyperplasia to further increase myofiber density, modulate the expression of MYHs to change myofiber type, and activate tight junction signaling pathway to narrow intermyofibrillar spaces. These findings will further accelerate the breeding of more appetizing and disease-resistant species.

Chemical and cryo-collection of muscle samples for transmission electron microscopy using Methacarn and dimethyl sulfoxide✰

Muscle samples are commonly chemically fixed or frozen immediately upon collection for biochemical and morphological analysis. Certain fixatives such as glutaraldehyde and osmium tetroxide are widely used for transmission electron microscopy (TEM) and lead to adequate preservation of muscle ultrastructure, but do not preserve the molecular features of samples. Methacarn is suggested to be a preferable chemical fixative for light microscopy because it maintains immunohistological features of samples. However, the efficacy of methacarn to preserve ultrastructural features as a primary chemical fixative for TEM is currently unclear. Additionally, cryo-preservation of samples for TEM analysis involves freezing processes such as plunge freezing, slam freezing, or high pressure freezing. High pressure freezing is the considered the gold standard but requires costly equipment and may not be a viable option for many labs collecting tissue samples from remote locations. Dimethyl sulfoxide (DMSO) is a commonly used cryoprotectant that may allow for better structural preservation of samples by impairing ice damage that occurs during plunge/snap freezing. We aimed to assess the effectiveness of methacarn as a primary chemical fixative and determine the effect of pre-coating samples with DMSO before plunge/snap freezing tissues to be prepared for TEM. The micrographs of the methcarn-fixed samples indicate a loss of Z-disk integrity, intermyofibrillar space, mitochondria structure, and lipids. Ultimately, methacarn is not a viable primary fixative for tissue sample preparation for TEM. Similarly, liquid nitrogen freezing of samples wrapped in aluminum foil produced non-uniform Z-disk alignments that appeared smeared with swollen mitochondria. DMSO coating before freezing appears to lessen the alterations to contractile and mitochondrial morphological structures. DMSO appears to be useful for preserving the ultrastructure of sarcomeres if samples are covered before freezing.

Muscle tissue structural changes in bombay-duck (Harpodon nehereus) induced by formaldehyde solution during post-mortem storage

Formaldehyde is a harmful compound that is usually used as an illegal preservative agent in fisheries products to prevent spoilage and extend shelf life. In several fishery products, formaldehyde can be formed endogenously during the post mortem process through degradation of trimethylamine oxide (TMAO) by enzymatic process. Exogenous and endogenous formaldehyde can affect the textural and structural change in fish muscle tissue significantly influencing flesh quality. This study was aimed to characterize the structural change of the muscle tissue in Bombay duck (Harpodon nehereus) that is immersed with formaldehyde solution on chilling storage temperature. The Scanning Electron Microscope (SEM) analysis was used to identify and characterize the structural change in muscle tissue samples, which were immersed with formaldehyde solution 0%, 1%, 3%, and 5%. SEM analysis identified that in transversal section samples immersed with formaldehyde solution 0% (control) intermyofibrillar space was increased significantly during post mortem storage. This was in line with the increased of myofibril, connective tissue and sarcolemma lost on samples. Furthermore, on samples that were immersed with formaldehyde solution 1%,3%, and 5% the degradation of myofibril and intermyofibrillar was can be held and the connectivity tissue muscle still showed strong aggregation during post mortem storage.

High-avidity binding drives nucleation of amyloidogenic transthyretin monomer.

Amyloidosis involves stepwise growth of fibrils assembled from soluble precursors. Transthyretin (TTR) naturally folds into a stable tetramer, whereas conditions and mutations that foster aberrant monomer formations facilitate TTR oligomeric aggregation and subsequent fibril extension. We investigated the early assembly of oligomers by WT TTR compared with its V30M and V122I variants. We monitored time-dependent redistribution among monomer, dimer, tetramer, and oligomer contents in the presence and absence of multimeric TTR seeds. The seeds were artificially constructed recombinant multimers that contained 20–40 TTR subunits via engineered biotin-streptavidin (SA) interactions. As expected, these multimer seeds rapidly nucleated TTR monomers into larger complexes, while having less effect on dimers and tetramers. In vivo, SA-induced multimers formed TTR-like deposits in the heart and the kidney following i.v. injection in mice. While all 3 variants prominently deposited glomerulus in the kidney, only V30M resulted in extensive deposition in the heart. The cardiac TTR deposits varied in size and shape and were localized in the intermyofibrillar space along the capillaries. These results are consistent with the notion of monomeric TTR engaging in high-avidity interactions with tissue amyloids. Our multimeric induction approach provides a model for studying the initiation of TTR deposition in the heart.

Abstract 9749: High-Avidity Binding Drives Nucleation of Amyloidogenic Transthyretin Monomer in Cardiac Amyloidosis

Amyloidosis involves stepwise growth of fibrils assembled from soluble precursor proteins. Mutations of plasma carrier protein transthyretin (TTR) are associated with hereditary transthyretin amyloidosis (ATTR). TTR naturally folds into a stable tetramer for its function, whereas conditions and mutations that foster aberrant monomer formation facilitate TTR oligomeric aggregation and subsequent fibril extension. We investigated the dynamics of early assembly of oligomers by wild-type TTR, in comparison to its TTR V30M and TTR V122I disease mutants. We selected buffer conditions for monitoring time-dependent redistribution among monomer, dimer, tetramer, and oligomer contents in the presence and absence of multimeric TTR seeds. The seeds were artificially constructed recombinant multimers that contained 20-40 TTR subunits via engineered biotin-streptavidin interactions. As expected, these multimer seeds rapidly nucleated TTR monomers and dimers into larger complexes, while having no effect on tetramers. In vivo , streptavidin-induced multimers formed ATTR-like deposits in the heart and the kidney following i.v. injection in mice. While all three variants prominently deposited in the kidney glomerulus, only TTR V30M resulted in extensive deposition in the heart. The cardiac TTR deposits varied in size and shape and were localized to the intermyofibrillar space along the capillaries. These results are consistent with the notion of monomeric TTR to engage high-avidity interactions with tissue amyloids. Our multimeric induction approach therefore provides a new model for studying the initiation of TTR deposition in the heart.

Effect of varying salt concentration on iridescence in precooked pork meat

The objective of this study was to investigate the effect of salt concentration on meat iridescence in cured cooked pork products. In addition, the influence of nitrite and pigmentary color on iridescence and its visual macroscopic perception was ascertained. Sample cubes from the pigs M. longissimus thoracis et lumborum were salted with either NaCl (20 g/kg, 40 g/kg) or nitrite curing salt (6 g/kg, 20 g/kg, and 40 g/kg) and subsequently cooked. Control samples were not salted. The effects of NaCl and curing salt on iridescence, instrumental color and microstructure were evaluated. Salt treatment significantly (p < 0.05) increased water-holding capacity, mean myofibers diameters and iridescence and reduced light scattering (L* value). An iridescence limit was reached with the 20 g/kg salt treatments. No differences between sodium chloride and nitrite curing salt were observed for both visual evaluation and colorimetry of the interference colors. Iridescence increases were attributed to a swelling of the myofilament lattice and thus reduction of intermyofibrillar spaces as well as an optical clearing of the myofibrils by dissolution of myofibrillar proteins that both reduce light scattering and allow more reflectance and interference to occur.Graphic abstract

Effect of Postmortem Phases on Lamb Meat Quality: A Physicochemical, Microstructural and Water Mobility Approach.

To investigate the effect of postmortem phases on lamb meat quality, the physicochemical quality, microstructure and water mobility of oyster cut, short loin, knuckle and silverside muscles from Small-Tail Han sheep were evaluated in the pre-rigor, rigor mortis and post-rigor phases. Pre-rigor lamb meat had higher pH and water holding capacity (WHC), whereas lower CIE L*, b*, hue angle values than rigor mortis and post-rigor meat (p<0.05). The Warner-Bratzler shear force (WBSF) values were higher in rigor mortis short loin and silverside than their pre-rigor and post-rigor counterparts, pre-rigor short loin had lower WBSF value than its post-rigor counterpart (p<0.05). Muscle fibers shrank laterally and longitudinally during the onset of rigor mortis. Rigor mortis and post-rigor lamb meat exhibited wide I-bands, dark A-bands, short sarcomeres and large inter-myofibrillar spaces. The shift of immobilized water to free water and repulsion from the intra-myofibrillar space to the extracellular space result in the increase of water loss in rigor mortis and post-rigor lamb meat. The results of the principal component analysis (PCA) indicated that rigor mortis and post-rigor lamb meat had similar quality properties but different from pre-rigor lamb meat. In conclusion, the lamb meat in the pre-rigor phase had good tenderness, color and WHC. The results of this research could provide some theoretical references for lamb meat production and processing.

Biochemical and histopathological effects in muscular tissue of carp fish (Labeo rohita, Hamilton 1822) following exposure to untreated and treated sewage water.

Present work describes a laboratory study aiming at assessing the impact of sewage treatment plant (STP) effluents on fish health by means of biochemical and histopathological biomarkers in muscular tissue of fish. Labeo rohita (7.62 ±0.25 cm, 8.25±0.32 g) was exposed to sub-lethal concentrations of untreated (UT) and treated (T) sewage water obtained from STP, Ludhiana, India. Following the determination of the 96h lethal concentration (LC50), the fish were exposed to control (de-chlorinated tap water), treated sewage water, 1/10th of LC50 UT and 1/20th of LC50 UT sewage water. The experiment was conducted for the period of 60 days. Experimental results depicted significant reduction (p<0.05) in muscle-somatic index of 1/10th LC50 UT and 1/20th LC50 UT groups compared to control and treated groups. Fish toxicity induced by untreated sewage water was evident from the significant decrease (p<0.05) in the levels of proteins and significant increase (p<0.05) in content of total lipids in muscular tissue of exposed group fingerlings. Drastic changes in the fatty acids profile and severe histological abnormalities viz. shortening of muscle bundles, edema, hyper-vacuolization, elongation of muscle bundles, gap formation in myofibrils, degenerated myotomes, hemorrhage, inter-myofibrillar space, necrosis, were also recorded in muscular tissue of exposed fingerlings. The intensity of muscular damage in L.rohita was found to increase with increase in duration of exposure. Results demonstrated that untreated sewage water could potentially induce physiological stress and somatic cell toxicity in fish L.rohita. Genotoxicity studies on germ cells of L.rohita fingerlings are further suggested to examine the genotoxic potential of untreated sewage water at high concentrations; this is especially of interest given that many effluents are genotoxic to fish.

Effects of faba bean on growth performance and fillet texture of Yellow River carp, Cyprinus carpio haematopterus

A three-month feeding trial was conducted to investigate the effects of faba bean (Vicia faba L.) on growth performance, intramuscular collagen content, muscle cellularity and fillet texture of Yellow River carp, Cyprinus carpio haematopterus. Carps with an initial weight 500 ± 20 g were randomly divided into two treatments: commercial feed group (CFG) and faba bean group (FBG). Compared to CFG, the results indicated that carps fed with faba bean had poor growth performance, higher intramuscular collagen content, smaller fiber diameter and wider intermyofibrillar space. However, the fiber density was not influenced (P > 0.05). The faba bean components showed lower crude protein and amino acid imbalance, especially, the deficiency in the sulfuric amino acid. The raw-fillet and cooked-fillet texture of FBG were both significantly greater than that of CFG (P < 0.05). Muscle fiber diameter and cooked-fillet texture showed significant negative correlation (P < 0.05), significant positive correlation between intramuscular collagen content and cooked-fillet texture (P < 0.05), and no significant correlation between muscle fiber density and fillet texture (P> 0.05). In summary, faba bean could improve the fillet quality for Yellow River carp. These findings would contribute to define the optimal nutritional conditions of pond culture to improve the flesh quality of Cyprinus carpio haematopterus.

Structural and Ultrastructural Changes in Muscle Tissue of Skate (Raja kenojel) during Fermentation at 10°C

ABSTRACTStructural changes in skate muscle during fermentation could significantly influence flesh quality of products. Thus, the objective of this study was to characterize the structural and ultrastructural changes of skate muscle that occur during fermentation. In skate flesh samples, typical muscle tissue experiences changes, including detachment of myofibrils from the endomysium, fiber to fiber, and increase of the intermyofibrillar spaces during fermentation. Even though the myofibrillar ultrastructure was drastically damaged during fermentation, the most significant feature in muscle tissue was aggregate formation involving protein–protein and protein–water interactions. Based on our results, it is assumed that the protein aggregation and denaturation of structural changes in the skate muscle during fermentation contributed to the unique textural and organoleptic characteristics of the final skate products.

The ultrastructural anatomy of the nuclear envelope in the masseter muscle indicates its role in the metabolism of the intracellular Ca++

Specific ultrastructural anatomy of masticatory muscles is commonly referred to a general pattern assigned to striated muscles. Junctional feet consisting of calcium channels of the sarcoplasmic reticulum (i.e. the ryanodine receptors, RyRs) physically connected to the calcium channels of the t-tubules build triads within striated muscles. Functional RyRs were demonstrated in the nuclear envelopes of pancreas and of a skeletal muscle derived cell line, but not in muscle in situ. It was hypothesized that ryanodine receptors (RyRs) could also exist in the nuclear envelope in the masseter muscle, thus aiming at studying this by transmission electron microscopy. There were identified paired and consistent subsarcolemmal clusters of mitochondria, appearing as outpockets of the muscle fibers, usually flanking an endomysial microvessel. It was observed on grazing longitudinal cuts that the I-band-limited mitochondria were not strictly located in a single intermyofibrillar space but continued transversally over the I-band to the next intermyofibrillar space. It appeared that the I-band-limited transverse mitochondria participate with the column-forming mitochondria in building a rather incomplete mitochondrial reticulum of the masseter muscle. Subsarcolemmal nuclei presented nuclear envelope-associated RyRs. Moreover, t-tubules were contacting the nuclear envelope and they were seemingly filled from the perinuclear space. This could suggest that nucleoplasmic calcium could contribute to balance the cytosolic concentration via pre-built anatomical routes: (i) indirectly, via the RyRs of the nuclear envelope and (ii) directly via the communication of t-tubules and sarcoplasmic reticulum through the perinuclear space.

Intracellular Reorganization of Cardiomyocytes in Dyslipidemic Cardiomyopathies.

The study examined the myocardial ultrastructural alterations in rats maintained on various atherogenic diets. It revealed the complex ultrastructural alterations of cardiomyocytes and endotheliocytes (including the lytic and destructive changes of the intracellular organelles, upregulation of the autophagocytosis in the cardiomyocytes, and necrobiosis with apoptosis of endotheliocytes) reflecting the cytopathic features of circulating cholesterol and lipoproteins, whose elevation determined the intensity of destructive processes. The revealed peculiarities in the changes of lipid inclusions (their osmiophilic transformation) in cardiomyocytes can be provoked by entry of cholesterol into the cells and its further metabolic modifications. During moderate dyslipidemia, the cardiomyocytes demonstrated the ultrastructural signs of induction of intracellular regeneration (marked with the clusters of polysomes in the intermyofibrillar and subsarcolemmal spaces with appearance of neogenic myofilaments) and upregulated pinocytotic activity. In all cases, up-regulated autophagocytosis in cardiomyocytes was accompanied by accumulation of myelin- and vacuole-like structures in the intercellular spaces and capillary lumens paralleled with appearance of activated forms of macrophages and fibroblasts in the myocardium.

An automated workflow for segmenting single adult cardiac cells from large-volume serial block-face scanning electron microscopy data.

This paper presents a new algorithm to automatically segment the myofibrils, mitochondria and nuclei within single adult cardiac cells that are part of a large serial-block-face scanning electron microscopy (SBF-SEM) dataset. The algorithm only requires a set of manually drawn contours that roughly demarcate the cell boundary at routine slice intervals (every 50th, for example). The algorithm correctly classified pixels within the single cell with 97% accuracy when compared to manual segmentations. One entire cell and the partial volumes of two cells were segmented. Analysis of segmentations within these cells showed that myofibrils and mitochondria occupied 47.5% and 51.6% on average respectively, while the nuclei occupy 0.7% of the cell for which the entire volume was captured in the SBF-SEM dataset. Mitochondria clustering increased at the periphery of the nucleus region and branching points of the cardiac cell. The segmentations also showed high area fraction of mitochondria (up to 70% of the 2D image slice) in the sub-sarcolemmal region, whilst it was closer to 50% in the intermyofibrillar space. We finally demonstrate that our segmentations can be turned into 3D finite element meshes for cardiac cell computational physiology studies. We offer our large dataset and MATLAB implementation of the algorithm for research use at www.github.com/CellSMB/sbfsem-cardiac-cell-segmenter/. We anticipate that this timely tool will be of use to cardiac computational and experimental physiologists alike who study cardiac ultrastructure and its role in heart function.

Atg5flox-Derived Autophagy-Deficient Model of Pompe Disease: Does It Tell the Whole Story?

Defective autophagy is a prominent feature in Pompe disease, an inherited deficiency of acid alpha-glucosidase. An absence of this enzyme leaves cells unable to digest glycogen in the lysosome. The major tissues affected by glycogen accumulation are cardiac and skeletal muscles. The currently available enzyme replacement therapy (ERT) works well in cardiac, but not in skeletal muscle. The disappointing response to therapy is linked to the presence of large areas of autophagic debris in muscle fibers.

Histopathological pattern recognition of cresty neck in horses in Spain

The aim of this study was to describe patterns of histopathological recognition of the cresty neck in Horses in Spain. A total of 250 horses were studied in Andalusia and Extremadura, Spain. Seventy-six percent of horses present cresty neck. The damage of the cresty neck in horses was categorized as Grade 0 - Muscle fibers are observed, no fat vacuoles are observed (24% of the horses). Grade 1 – Scarce adipose deposit was observed. An unaltered muscle tissue is observed (21% of the horses). Grade 2 - fat vacuoles are evident in muscle tissue intermyofibrillar space and prone to coalescence (23% of the horses). Grade 3 - Abundant fat vacuoles in the intermyofibrillar space, with tendency to coalesce, and low fat infiltration in muscle tissue (moderate lipomatosis) (16% of the horses). Grade 4 - Abundant fat vacuoles in the intermyofibrillar space, with tendency to coalesce, and fatty infiltration in muscle tissue (marked lipomatosis) (8% of the horses). Grade 5 - Only fat vacuoles are observed, without muscle tissue (severe lipomatosis) (8% of the horses). The results for desmin antibody (1: 100 dilution) was positive (++) in grades 0-2, and negative (-) in grades 3-5. These results suggest that as fat/lipomatosis infiltration increases (progresses in grades 3, 4 and 5), the intercellular space (intermyofibrillar) increases and therefore the cell cytoskeleton is lost, with loss of the bands Z, so the negative response to this antibody. In conclusion, we describe histopathological pattern recognition of cresty neck in horses in Spain.

Understanding tenderness variability and ageing changes in buffalo meat: biochemical, ultrastructural and proteome characterization

Understanding of biological impact of proteome profile on meat quality is vital for developing different approaches to improve meat quality. Present study was conducted to unravel the differences in biochemical, ultrastructural and proteome profile of longissimus dorsi muscle between buffaloes (Bubalus bubalis) of different age groups (young v. old). Higher (P<0.05) myofibrillar and total protein extractability, muscle fibre diameter, and Warner-Bratzler shear force (WBSF) values was observed in old buffalo meat relative to meat from young buffaloes. Scanning electron microscopy photographs revealed reduced fibre size with increased inter-myofibrillar space in young compared with old buffalo meat. Transmission electron microscopy results revealed longer sarcomeres in young buffalo meat relative to meat from old buffaloes. Proteomic characterization using two-dimensional gel electrophoresis (2DE) found 93 differentially expressed proteins between old and young buffalo meat. Proteome analysis using 2DE revealed 191 and 95 differentially expressed protein spots after 6 days of ageing in young and old buffalo meat, respectively. The matrix assisted laser desorption ionization time-of flight/time-of flight mass spectrometry (MALDI-TOF/TOF MS) analysis of selected gel spots helped in identifying molecular markers of tenderness mainly consisting of structural proteins. Protein biomarkers identified in the present study have the potential to differentiate meat from young and old buffaloes and pave the way for optimizing strategies for improved buffalo meat quality.