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Biomedical subjects

F Mascarello

Publications and source records attributed to F Mascarello.

At least 19 recordsLinked to original sources
PubMed2005

Expression of eight distinct MHC isoforms in bovine striated muscles: evidence for MHC-2B presence only in extraocular muscles.

This study aimed to analyse the expression of myosin heavy chain (MHC) isoforms in bovine muscles, with particular attention to the MHC-2B gene. Diaphragm, longissimus dorsi, masseter, several laryngeal muscles and two extraocular muscles (rectus lateralis and retractor bulbi) were sampled in adult male Bos taurus (age 18-24 months, mass 400-500 kg) and analysed by RT-PCR, gel electrophoresis and immunohistochemistry. Transcripts and proteins corresponding to eight MHC isoforms were identified: MHC-alpha and MHC-beta/slow (or MHC-1), two developmental isoforms (MHC-embryonic and MHC-neonatal), three adult fast isoforms (MHC-2A, MHC-2X and MHC-2B) and the extraocular isoform MHC-Eo. All eight MHC isoforms were found to be co-expressed in extrinsic eye muscles, retractor bulbi and rectus lateralis, four (beta/slow, 2A, 2X, neonatal) in laryngeal muscles, three (beta/slow, 2A and 2X) in trunk and limb muscles and two (beta/slow and alpha) in masseter. The expression of MHC-2B and MHC-Eo was restricted to extraocular muscles. Developmental MHC isoforms (neonatal and embryonic) were only found in specialized muscles in the larynx and in the eye. MHC-alpha was only found in extraocular and masseter muscle. Single fibres dissected from masseter, diaphragm and longissimus were classified into five groups (expressing, respectively, beta/slow, alpha, slow and 2A, 2A and 2X) on the basis of MHC isoform electrophoretical separation, and their contractile properties [maximum shortening velocity (v(0)) and isometric tension (P(0))] were determined. v(0) increased progressively from slow to fast 2A and fast 2X, whereas hybrid 1-2A fibres and fibres containing MHC-alpha were intermediate between slow and fast 2A.

Analysis of Variance↗
PubMed2003

Characteristics of fungal phytases from Aspergillus fumigatus and Sartorya fumigata.

Aspergillus fumigatus phytase has previously been identified as a phytase with a series of favourable properties that may be relevant in animal and human nutrition, both for maximising phytic acid degradation and for increasing mineral and amino acid availability. To study the natural variability in amino acid sequence and its impact on the catalytic properties of the enzyme, we cloned and overexpressed the phytase genes and proteins from six new purported A. fumigatus isolates. Five of these phytases displayed < or= 2 amino acid substitutions and had virtually identical stability and catalytic properties when compared with the previously described A. fumigatus ATCC 13073 phytase. In contrast, the phytase from isolate ATCC 32239 ( Sartorya fumigata, the anamorph of which was identified as A. fumigatus) was more divergent (only 86% amino acid sequence identity), had a higher specific activity with phytic acid, and displayed distinct differences in substrate specificity and pH-activity profile. Finally, comparative experiments confirmed the favourable stability and catalytic properties of A. fumigatus phytase.

6-Phytase↗
PubMed2001

Characterization of the myostatin gene in the gilthead seabream (Sparus aurata): sequence, genomic structure, and expression pattern.

We report on the sequence and expression analysis of the myostatin gene (MSTN) in the gilthead seabream Sparus aurata. A 2189-bp transcript was isolated, encoding an open reading frame (385 amino acids) that showed 74% to 60% protein similarity with other vertebrate myostatins. Phylogenetic analysis of MSTN and other related genes confirmed the evolutionary relationships of the isolated sequence. The complete sequences of two introns were also determined. Intron-exon boundaries were conserved when compared with those of mammalian MSTN genes, whereas intron size was smaller. Reverse transcriptase polymerase chain reaction on total RNA extracted from different tissues and developmental stages revealed MSTN expression in the skeletal muscle, but also in other tissues. The observed expression profile differed from that in mammals, suggesting possible additional functions of myostatin in the teleost fish.

Journal Article↗
PubMed2001

Neurotransmitters, neuromodulators, and neurotrophin receptors in the gut of pantex, a hybrid sparid fish (Pagrus major x Dentex dentex). Localizations in the enteric nervous and endocrine systems.

The gut of Pantex, a sparid hybrid fish (Pagrus major x Dentex dentex) with a great potential importance for the Italian aquaculture, was histochemically and immunohistochemically investigated in order to evidence components of the intramural nervous and diffuse endocrine systems. The general structural aspects of the intramural nervous system were shown by the Nissl-thionin staining. As in most other fish, it was only organized in the myenteric plexus. Acetylcholinesterase (AChE) activity was observed in both nerve cell bodies and terminals all along the gut. The NADPH-diaphorase reactivity too, possibly linked to the synthesis and release of nitric oxide, was present in nerve cell bodies and nerve terminals of the oesophagus, stomach and intestine. In addition, the intramural nervous system was shown to contain Trk (tyrosinekinase) receptors for neurotrophin, as evidenced by Trk A-, Trk B- and Trk C-like immunoreactivities, thus suggesting an involvement of neurotrophin in the function of this system. Trk B- and Trk C-like immunoreactivities were detected in epithelial endocrine cells, too. The additional presence of serotonin- and metenkephalin-like immunoreactivities in numerous endocrine cells in the epithelial layers of the stomach and intestine was showed.

Acetylcholinesterase↗
PubMed2000

Ultrastructural features of the gut in the white sturgeon, Acipenser transmontanus.

Electron-microscopic examinations of the sturgeon gut were performed. Oesophageal goblet cells were abundant in the stratified epithelium. The ultrastructural features of the secretory granules of the oesophageal and intestinal goblet cells were quite similar to those of other vertebrates. Lobules of multilocular adipose tissue were observed in the deep tunica propriasubmucosa of the oesophagus, in close association with vasculature and large fibre bundles of myelinated and unmyelinated axons. Similarly composed nerve fibre bundles were observed in the cardiac stomach, too. The presence of myelinated axons is an unusual feature in the vertebrate enteric nervous system. Cardiac and fundic zones of the stomach showed an epithelium with columnar ciliated and non-ciliated cells, the latter equipped with fuzzy microvilli. Cells lining the tubular gastric proper glands were markedly granulated. Intestinal superficial epithelium was columnar and contained ciliated, as well as non-ciliated and goblet cells. In the tunica propria all over the intestine, the presence and ultrastructure of granulated cells was in addition described. Intraepithelial granulated leukocytes were seen throughout the alimentary canal. Various types of endocrine cells were seen both in the stomach and in the intestine, the size of their granules was measured and their ultrastructure described and compared to that of mammalian cell types.

Animals↗
PubMed2000

Neurotransmitters and putative neuromodulators in the gut of Anguilla anguilla (L.). Localizations in the enteric nervous and endocrine systems.

The gut of silver eels (Anguilla anguilla L.) was investigated in order to describe both the cholinergic and adrenergic intramural innervations, and the localization of possible accessory neuromediators. Histochemical reactions for the demonstration of nicotinamide adenine dinucleotide phosphate, reduced form-(NADPH-)diaphorase and acetylcholinesterase (AChEase) were performed, as well as the immunohistochemical testing of tyrosine hydroxylase, met-enkephalin, substance P, calcitonin gene-related peptide (CGRP), bombesin, vasoactive intestinal peptide (VIP), neuropeptide Y (NPY), somatostatin, cholecystokinin-octapeptide (CCK-8), serotonin, cholineacetyl transferase. The results evidenced a different pattern in comparison with other vertebrates, namely mammals, and with other fish. Both NADPH-diaphorase and AChEase activities were histochemically detected all along the gut in the myenteric plexus, the inner musculature and the propria-submucosa. Tyrosine hydroxylase immunoreactivity was observed in the intestinal tract only, both in the myenteric plexus and in the inner musculature. Several neuropeptides (metenkephalin, CGRP, bombesin, substance P, VIP, NPY, somatostatin) were, in addition, detected in the intramural innervation; some of them also in epithelial cells of the diffuse endocrine system (met-enkephalin, substance P, NPY, somatostatin). Serotonin was only present in endocrine cells. Tyrosine hydroxylase immunoreactivity was present in localizations similar to those of NADPH-diaphorase-reactivity, and in the same nerve bundles in which substance P- and CGRP-like-immunoreactivities were detectable in the intestinal tract. In addition, NADPH-diaphorase-reactive neurons showed an anatomical relationship with AChEase-reactive nerve terminals, and a similar relationship existed between the latter and substance P-like immunoreactivity.

Anguilla↗
PubMed1999

Morphological and histochemical peculiarities of the gut in the white sturgeon, Acipenser transmontanus.

The gut of adult sturgeon was examined. The oesophageal mucosa contained numerous caliciform cells, synthesizing both neutral and acidic glycoconjugates, the latter of the sialylated type. The deep tunica propria-submucosa contained lobules of multilocular adipose tissue, specially abundant during the cold season. The oesophageal tunica muscularis was made up of a large sheath of striated muscle fibres, arranged orthogonally to a thin, subserous smooth muscle layer. The siphon-shaped stomach showed a ciliated epithelium in cardiac and gastric proper gland zones, where tubular glands were present in the tunica propria. The columnar cells which composed the superficial epithelium and gastric pits were demonstrated to synthesize almost exclusively neutral glycoconjugates. Appendices pyloricae constituted a glandular body equipped with intestinal mucosa. The intestinal mucosa was organized in folds, containing numerous caliciform cells which synthesized neutral or acidic glycoconjugates, the latter either of the sialylated and sulphated type. The sulphoglycoconjugates were more abundant in the caliciform cells of the distal intestinal tracts. The tunica propria-submucosa of the spiral valve (medium intestine) contained lymphatic tissue and large lymphatic follicles. A muscularis mucosae was present only in the rectum, where in addition a peculiar granular cell type was present in the superficial tunica propria-submucosa, possibly related to defensive properties. The subserous connective tissue contained pancreatic lobules all along the stomach and intestine. The enteric nervous system showed some special aspects, the most intriguing of which was the presence of large, longitudinally oriented nerve bundles in the t. propria-submucosa of oesophagus and cardiac stomach. The nerve bundles contained, near unmyelinated nerves, some myelinated nerves, as well as neuronal bodies. Both these aspects are exceptional in vertebrates and obscure in their significance. The structural and histochemical aspects we here describe are in part different from those described for other fish. Some of these special features are possibly related with special functional roles, others require a deeper insight and different approaches to clarify them functionally.

Animals↗
PubMed1998

Muscle growth in response to changing demands of functions in the teleost Sparus aurata (L.) during development from hatching to juvenile.

Growth of laterarl muscle in the teleost fish Sparus aurata (L.) was examined from hatching to juvenile by a basic morphofunctional approach that takes into account structural and ecophysiological aspects and combines in vivo observations and LM and TEM microscopic analysis. As shown in most teleost fishes, muscle growth proceeds by a double mechanism of hyperplasia and hypertrophy that contribute differentially to the overall development of the lateral muscle, giving rise in each myomere to a typical pattern of structurally and functionally different fibre types (slow-red and fast-white fibres, plus pink intermediate fibres) in a nerve-dependent process. During larval life the muscle growth takes place mainly due to hyperplastic growth at the level of specific proliferative zones of the myomeres, from which slow, pink and white muscle fibres are derived. In those species that reach a large adult size a new typical hyperplastic process disseminated throughout the fast white muscle layer takes place during post-larval life. In contrast, hypertrophic growth occurs in all stages, but is the dominant mechanism of muscle growth only in juvenile and adult. The suitable recruitment of the different fibre types enables the fish to optimize its performances according to specific functional and metabolic requirements related to the swimming behaviour and hydrodynamic regimes. The different mechanisms of growth are here analysed in their detailed structural and ultrastructural aspects in order to interpret their adaptive significance in the light of the fish life cycle, with particular reference to locomotion and feeding behaviour.

Animals↗
PubMed1998

Different putative neuromodulators are present in the nerves which distribute to the teleost skeletal muscle.

The presence of putative neuromodulators in the nerve fibres was investigated in white skeletal muscle of two teleost fish not taxonomically correlated and showing different patterns of innervation (multiple versus focal innervation). Cryostat sections of epaxial, hypaxial and adductor mandibulae (AM) muscles of Sparus aurata and Anguilla anguilla were stained histochemically for reduced nicotinamide adenine dinucleotide phosphate (NADPH)-diaphorase. Other sections were used for indirect immunohistochemistry (streptavidin-biotin and rhodamine immunofluorescence methods), employing antibodies specific for putative excitatory or inhibitory peptides, including CGRP, substance P, met-enkephalin, bombesin, and VIP. In addition, ultrastructural observations were performed in order to describe the morphology of the motor endplates. A strong immunoreactivity for CGRP and substance P was found in many nerve terminals. Met-enkephalin, bombesin and VIP immunoreactivities were less frequently observed. No immunoreactivity was observed to CCK, NPY or 5-HT. NADPH-diaphorase was identified in nerve fibres of the AM complex only of A. anguilla. Electron microscopy observations evidenced more than one type of synaptic vesicle in motor endplates. Some differences in putative neuromodulator distributions were observed in the two species and muscle complexes, which may be related to the different taxonomical position as well as the different pattern of innervation of white muscle fibres.

Anguilla↗
PubMed1997

Regeneration of skeletal muscle in two teleost fish: Sparus aurata and Brachydanio rerio.

Regeneration of skeletal muscle was studied in the sea bream Sparus aurata, in which extensive post-larval muscle hyperplasia contributes to its large adult size, and in the zebrafish Brachydanio rerio, which shows little post-larval hyperplasia and reaches only a small adult size. Small mechanical lesions of body wall muscle were made under general anaesthesia, and the progress of subsequent regeneration was assessed at various intervals by histology and electron microscopy (for general morphology), by immunostaining for desmin and myosin isoforms (to identify the phenotype of new fibres), and by 5'-bromo-2'-deoxyuridine (BrdU) incorporation (to identify proliferating cells). Despite the difference in normal growth-related hyperplasia in these fish, a vigorous regeneration occurred in both species, giving rise to new fibres with an initial myosin composition that differed from that in mature fast-white fibres. However, species differences in myosin expression in these fibres suggest that they may have derived from different myoblast populations. In sea bream, myosin expression in regenerating fibres resembled that seen in new fibres produced in post-larval white muscle, whereas in the zebrafish it resembled that of the primitive monolayer fibres formed during embryonic development. Subsequently, most regenerating fibres gradually transformed into the mature fast-white phenotype in both species.

Animals↗
PubMed1995

Differentiation and growth of muscle in the fish Sparus aurata (L): I. Myosin expression and organization of fibre types in lateral muscle from hatching to adult.

Post-hatching development of lateral muscle in a teleost fish, Sparus aurata (L) was examined. At hatching only two fibre types were present, several layers of mitochondria-poor, myofibril-rich deep muscle fibres surrounded the notochord and were covered by a superficial monolayer of mitochondria-rich, myofibril-poor A third ultrastructurally distinct fibre type first appeared as one or two fibres located just under the lateral line at 6 days post-hatching. This type, which gradually increased in number during larval life, contained a slow isoform of myosin, identified by mATPase staining and immunostaining with myosin isoform-specific antibodies. Deep muscle fibres--the presumptive fast-white type--contained a fast myosin, and superficial monolayer fibres an isoform similar but not identical to that in adult pink muscle fibres. The only fibres present during larval life which showed a clear change in myosin expression were the superficial monolayer fibres, which gradually transformed into the slow type post-larvally. Pink muscle fibres first appeared near the end of larval life. Both slow and pink muscle fibres remained concentrated around the horizontal septum under the lateral line during larval life, expanding outwards towards the apices of the myotomes only after metamorphosis. Between 60 and 90 days very small diameter fibres with a distinct mATPase profile appeared scattered throughout the deep, fast-white muscle layer, giving it a 'mosaic' appearance, which persisted into adult life. A marked expansion in the slow muscle layer began at the same time, partly by transformation of superficial monolayer fibres, but mainly by addition of new fibres both on the deep surface of the superficial monolayer and close to the lateral line. The order of appearance of these fibre types, their myosin composition, and the significance of the superficial monolayer layer are discussed and compared to muscle fibre type development in higher vertebrates.

Aging↗
PubMed1995

Differentiation and growth of muscle in the fish Sparus aurata (L): II. Hyperplastic and hypertrophic growth of lateral muscle from hatching to adult.

Post-hatching growth of lateral muscle in a teleost fish, Sparus aurata (L) was studied morphometrically to identify and quantify muscle fibre hyperplasia and hypertrophy, and by in vivo nuclear labelling with 5-bromo-deoxyuridine to identify areas of myoblast proliferation. Muscle fibre types were identified principally by myosin ATPase histochemistry and immunostaining, and labelled nuclei were identified at light and electronmicroscope level by immunostaining with a specific monoclonal antibody. Hyperplastic growth was slow at hatching, but then increased to a maximum at the mid-point of larval life. Larval hyperplastic growth occurred by apposition of new fibres along proliferation zones, principally just under the lateral line and in the apical regions of the myotome, but also just under the superficial monolayer at intermediate positions. The first of these zones gave rise to slow and pink muscle fibres, in a process which continued through into postlarval life. The other zones added new fibres to the fast-white muscle layer in a process which was exhausted by the end of larval life. Post-larvally, between 60 and 90 days posthatching, a new hyperplastic process started in the fast-white muscle as nuclei proliferated and new muscle fibres were formed throughout the whole layer. This process resulted in a several-fold increase in the number of fast-white fibres over a few weeks, and then waned to very low levels in juveniles. Hyperplasia by apposition continued for some time postlarvally on the deep surface of the superficial monolayer, but at this stage gave rise to slow fibres only. Hypertrophic growth occurred at all ages, but was the dominant mechanism of muscle growth only in the juvenile and adult stages. Mechanisms giving rise to these different growth processes in fish muscle are discussed, and compared with muscle development in higher vertebrates.

Aging↗
PubMed1995

Natural involution of muscle in the proximal sesamoidean ligament in sheep.

In sheep, the muscle component of the proximal sesamoidean ligament, which is well developed at birth, undergoes a progressive involution postnatally. The development of muscle fibres in the proximal sesamoidean ligament was compared with masseter and semimembranosus muscles from before birth into adult life, using histochemical, immunohistochemical and biochemical methods. Neonatal myosin (a marker for developmental immaturity) disappeared earlier, and the adult pattern of myosin expression and fibre type composition was reached earlier in the proximal sesamoid ligament than masseter and semimembranosus. Proximal sesamoid ligament muscle fibres therefore complete normal development, but with a faster time course than the other muscles. Invasion of fibrous connective tissue between muscle fibres of the proximal sesamoidean ligament adjoining the tendinous component (one feature of the involution) was found to begin perinatally, eventually resulting in a marked fibrosis and atrophy of peripheral fibres. Regeneration of muscle fibres was absent or abortive, even near areas of fibre necrosis.

Animals↗
PubMed1993

Muscle growth and myosin isoform transitions during development of a small teleost fish, Poecilia reticulata (Peters) (Atheriniformes, Poeciliidae): a histochemical, immunohistochemical, ultrastructural and morphometric study.

The myosin composition of lateral muscle in Poecilia reticulata from birth to adult was studied by ATPase histochemistry and immunostaining with myosin isoform-specific antibodies. At birth the muscle consists of two layers containing developmental isoforms of myosin. In deep layer fibres the developmental myosin is replaced by the adult fast-white isoform soon after birth. In the epaxial and hypaxial monolayer fibres the myosin composition present at birth (J1) is replaced within 3 days by another (J2). In some fibres, this J2 composition is retained in the adult, but in others it is slowly replaced by the adult slow-red muscle isoform. Close to the lateral line, all monolayer fibres are already in transition between the J2 myosin and the adult slow-red form at birth, and rapidly complete the transition to slow-red form. These fibres, together with others generated de novo in an underlying hyperplastic zone, form the red muscle layer of the adult. The pink muscle develops during the first month after birth, and by 31 days it consists of an outer, middle and inner layer. A few middle layer fibres are already present at birth, while the outer layer fibres first appear 3 days after birth. The thin inner layer is probably a transitional form between the middle pink and adult white types, and appears at about 31 days. A morphometric analysis showed that growth of the white muscle occurs principally by hypertrophy. Even at the magnification level of the electron microscope, no satellite cells or myoblasts which could give rise to new fibres were found in the white muscle, except in the far epaxial and hypaxial regions and only in the first 10 days. A zone of hyperplastic growth was also found lying just under the superficial monolayer close to the lateral line, and this presumably contributes fibres to the red and pink muscle layers.

Animals↗
PubMed1993

Morphological and histochemical characteristics of muscle fibre types in the flexor carpi radialis of the dog.

The canine flexor carpi radialis is subdivided into 2 portions. The radial portion which occupies one third of the cross-section is located caudomedially and is composed only of large type I fibres (43.53 +/- 0.6 microns minimum diameter) in levels close to the insertion. The cubital portion is located craniolaterally and contains fewer and smaller type I fibres (26.10 +/- 0.3 microns minimum diameter). It is hypothesised that the radial portion of the muscle, with its larger slow fibre population, contributes to forelimb postural function. The cubital portion, with its generally fast fibre population (IIA), may be more important in the muscle's recognised function (flexion of the carpal joint during locomotion).

Adenosine Triphosphatases↗
PubMed1993

Skeletal muscle fibre types in the dog.

Using a variety of histochemical methods we have investigated the mATPase reaction of skeletal muscle fibres in the dog. Types I, IIA, IIDog (peculiar to the dog) and IIC fibres were identified. The results reveal that the interpretation of the fibre type composition depends on the methods used.

Adenosine Triphosphatases↗
PubMed1992

Myosin isoform transitions during development of extra-ocular and masticatory muscles in the fetal rat.

The late fetal development of rat extra-ocular and masticatory muscles was examined by myosin immunohistochemistry. The pattern of slow and neonatal myosin isoform expression in primary and secondary myotubes in these muscles was generally similar to that seen by others in limb muscles. We observed a consistent difference between the Sprague-Dawley and Wistar rats in the degree of maturity reached by all muscles studied at a particular age. In both strains, extra-ocular muscles were also about one day in advance of the masticatory muscles. Thus, secondary myotubes were first seen at E17 in Wistar extraocular muscles, at E18 in Sprague-Dawley extra-ocular muscles and Wistar masticatory muscles, and at E19 in Sprague-Dawley masticatory muscles. There was a strikingly early and complete type differentiation of primary myotubes in extraocular muscles, and tonic myosin first appeared before birth in presumptive extrafusal tonic fibres in the orbital layer of the oculorotatory muscles. Throughout the late fetal period, retractor bulbi was composed of fast myotubes only, but these myotubes were not arranged in classical clusters. In the masticatory muscles at E17/E18 some slow primary myotubes started to express tonic myosin, and these presumptive spindle bag2 fibres were located only in regions of the muscles known to contain spindles in the adult. Presumptive bag1 fibres appeared about a day later (initially without tonic myosin), and in the region of the spindle cluster in anterior deep masseter extrafusal secondary myotube production appeared to be suppressed.

Animals↗