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1.
Clin Ter ; 175(2): 144-152, 2024.
Article in English | MEDLINE | ID: mdl-38571473

ABSTRACT

Background: Adolescence is a critical phase of development characterized by numerous physical, psychological and social changes. During this stage, individuals may engage in experimentation and risky behavior, leading to increased vulnerability to addiction. This article aims to present the results of a survey based on the HBSC (Health Behavior in School-aged Children) surveillance model in a province of Southern Italy for primary and secondary school students. Methods: We conducted a prospective study from March 2020 to April 2023 through the administration of a questionnaire to students of the healthcare faculties of the University of Messina and primary and secondary school students, composed of 19 items and based on HBSC surveillance. Results: We collected a total of 664 questionnaires. We found that smoking habits increase with age: approximately 31% of secondary school students declare they are real smokers compared to 40% of HCP students. At least once, in the three study groups, students experienced alcohol consumption at different rates, with younger students having a greater propensity to drink than older students. Fortunately, in our sample, no middle school students had tried cannabis. At the same time there is a surprising decrease in gambling in all categories compared to national data. Conclusions: The presence of addictive behaviors in our sample was found to be widespread despite being in line with the national trend. Furthermore, we have observed a reduction in recent years which needs to be investigated to assess the reasons. Primary prevention is probably the main weapon in the hands of politicians and must be applied early in school and community settings to reduce prevalence.


Subject(s)
Behavior, Addictive , Smoking , Adolescent , Child , Humans , Prospective Studies , Smoking/epidemiology , Surveys and Questionnaires , Risk-Taking , Behavior, Addictive/epidemiology
2.
Clin Ter ; 174(5): 412-419, 2023.
Article in English | MEDLINE | ID: mdl-37674450

ABSTRACT

Background: Many studies have shown that the stress level among healthcare university students is often as high as in workers who experience burnout. Our study investigated if it is possible to observe the burnout syndrome in these kind of students, able to significantly alter the quality of life, their approach to daily activities and relationship life. Methods: The study was conducted through the administration of an anonymous questionnaire, distributed online through messaging apps, during the breaks between lessons. It was formulated using the perceived stress scale (PSS) in its short formula in order to evaluate feelings and thoughts and the WHOQOL-AGE, in order to evaluate the quality of life. Results: The sample consisted of 292 university students aged between 18 and 49, with an average age of 22,42 ± 4,65. 16.4% does not often feel able to control the important things in life, 42.8% is often unable to manage personal problems. The PSS score of all our university students showed a high stress level in 6.2%, an average stress level in 57.2% and low stress level in 36.6%. The WHOQOL score shows that 42% had a high quality of life and only 4% had a poor quality of life, 54% had an intermediate quality of life and half of the sample was unsatisfied with the way he felt every day. Conclusions: Many students (63.4%) are subjected to stress study-related, even if does not affect their quality of live, therefore not perceiving it as negative. There is a gender difference: females have a higher level of stress than men. Two thirds of the sample has an average or high stress level; only a third has a low grade. Stress prevention in young university students must begin through a new way of teaching, even if a certain amount of stress study-related is stimulant.


Subject(s)
Burnout, Professional , Quality of Life , Male , Female , Humans , Infant, Newborn , Adolescent , Young Adult , Adult , Middle Aged , Universities , Students , Surveys and Questionnaires , Delivery of Health Care , Stress, Psychological/epidemiology , Stress, Psychological/etiology
3.
Geobiology ; 15(5): 664-677, 2017 09.
Article in English | MEDLINE | ID: mdl-28383164

ABSTRACT

Ammonium- and Fe(II)-rich fluid flows, known from deep-sea hydrothermal systems, have been extensively studied in the last decades and are considered as sites with high microbial diversity and activity. Their shallow-submarine counterparts, despite their easier accessibility, have so far been under-investigated, and as a consequence, much less is known about microbial communities inhabiting these ecosystems. A field of shallow expulsion of hydrothermal fluids has been discovered at depths of 170-400 meters off the base of the Basiluzzo Islet (Aeolian Volcanic Archipelago, Southern Tyrrhenian Sea). This area consists predominantly of both actively diffusing and inactive 1-3 meters-high structures in the form of vertical pinnacles, steeples and mounds covered by a thick orange to brown crust deposits hosting rich benthic fauna. Integrated morphological, mineralogical, and geochemical analyses revealed that, above all, these crusts are formed by ferrihydrite-type Fe3+ oxyhydroxides. Two cruises in 2013 allowed us to monitor and sampled this novel ecosystem, certainly interesting in terms of shallow-water iron-rich site. The main objective of this work was to characterize the composition of extant communities of iron microbial mats in relation to the environmental setting and the observed patterns of macrofaunal colonization. We demonstrated that iron-rich deposits contain complex and stratified microbial communities with a high proportion of prokaryotes akin to ammonium- and iron-oxidizing chemoautotrophs, belonging to Thaumarchaeota, Nitrospira, and Zetaproteobacteria. Colonizers of iron-rich mounds, while composed of the common macrobenthic grazers, predators, filter-feeders, and tube-dwellers with no representatives of vent endemic fauna, differed from the surrounding populations. Thus, it is very likely that reduced electron donors (Fe2+ and NH4+ ) are important energy sources in supporting primary production in microbial mats, which form a habitat-specific trophic base of the whole Basiluzzo hydrothermal ecosystem, including macrobenthic fauna.


Subject(s)
Ammonium Compounds/metabolism , Archaea/metabolism , Bacteria/metabolism , Ecosystem , Ferrous Compounds/metabolism , Hydrothermal Vents/microbiology , Iron/metabolism , Chemoautotrophic Growth , Mediterranean Islands , Volcanic Eruptions
4.
Comp Biochem Physiol A Mol Integr Physiol ; 165(2): 199-206, 2013 Jun.
Article in English | MEDLINE | ID: mdl-23499922

ABSTRACT

The environmental contamination caused by heavy metals raises the question of their effect on biological systems. Among bio-indicators useful to monitor the toxicological effects of these chemicals, Cnidarians offer a unique model. Cnidarians possess highly specialized stinging cells, termed nematocytes, which respond to hyposmotic solution with well established homeostatic parameters as an acute osmotic phase (OP), leading to cell swelling, and then a slower regulatory volume decrease (RVD) phase, causing cell shrinkage. Here we report the effect of 65% artificial sea water (ASW) containing heavy metals, such as Cd, La, Co, Cu and Zn (concentrations comprised between 100 and 0.1 µM) on both OP and RVD in nematocytes isolated from the jellyfish Pelagia noctiluca by 605 mM NaSCN plus 0.01 mM Ca(2+). The exposure of the cells to Co and La inhibited RVD but not OP. However, Cu, Cd and Zn prevented the OP in a dose-dependent manner and, hence, also the detection of RVD. These results suggest that, in isolated nematocytes, heavy metal pollutants impair RVD either directly or indirectly through interference with the OP, thus negating RVD. Although further studies need to clarify the exact mechanisms whereby heavy metals exert their toxicity, it is evident that nematocytes of Cnidarians could serve as a model for ecotoxicological investigations.


Subject(s)
Cnidaria/drug effects , Metals, Heavy/toxicity , Seawater/chemistry , Water Pollutants, Chemical/toxicity , Animals , Cell Size/drug effects , Cnidaria/cytology , Cnidaria/metabolism , Dose-Response Relationship, Drug , Environmental Monitoring/methods , Osmosis/drug effects , Time Factors
5.
Article in English | MEDLINE | ID: mdl-22526110

ABSTRACT

Nematocytes' discharge is triggered to perform both defense and predation strategies in cnidarians and occurs under chemico-physical stimulation. In this study, different compounds such as amino acids and proteins (mucin, albumin, poly-L: -lysine, trypsin), sugars and N-acetylate sugars (N-acetyl neuraminic acid, N-acetyl galactosamine, sucrose, glucose, agarose and trehalose), nucleotides (ATP and cAMP), were tested as chemosensitizers of nematocyte discharge in the oral arms of the scyphozoan Pelagia noctiluca, particularly abundant in the Strait of Messina (Italy). Excised oral arms were submitted to a combined chemico-physical stimulation by treatment with different compounds followed by mechanical stimulation by a non-vibrating test probe. Discharge induced by a chemico-physical stimulation was more significant than that obtained after mechanical stimulation alone. A chemosensitizing mechanism, with a dose-dependent effect, was observed after treatment with sugars, amino compounds such as glutathione, nucleotides and mucin, according to that already seen in sea anemones. Such findings suggest that, though Anthozoa and Scyphozoa exhibit different divergence times during the evolutionary process, the discharge activation exhibits common features, probably derived from their last common ancestor.


Subject(s)
Chemoreceptor Cells/physiology , Nematocyst/physiology , Scyphozoa/physiology , Signal Transduction , Amines/pharmacology , Amino Acids/pharmacology , Animals , Calcium/metabolism , Carbohydrates/pharmacology , Chemoreceptor Cells/drug effects , Dose-Response Relationship, Drug , Mechanotransduction, Cellular , Nematocyst/cytology , Nematocyst/drug effects , Nucleotides/pharmacology , Physical Stimulation , Proteins/pharmacology , Scyphozoa/cytology , Scyphozoa/drug effects , Signal Transduction/drug effects , Time Factors
6.
Article in English | MEDLINE | ID: mdl-19070675

ABSTRACT

The effect of different agents upon the haemolytic power of Aiptasia mutabilis crude venom was studied inhuman erythrocytes to determine its toxicity and stability. Nematocysts were isolated from acontia of the Anthozoan A. mutabilis and submitted to sonication for extracting crude venom. Aliquots of venom were tested in 0.05% erythrocyte suspensions in the presence of various factors such as proteases (papain,collagenase, trypsin, alpha-chymotrypsin); cations (Ca2+, Mg2+, Ba2+, K+ and Cu2+), osmotic protectants as polyethylenglycole (PEG) of different MW and antioxidant compounds (GSH, cysteine and ascorbic acid).Results demonstrate the dose-response of the haemolytic effect of A. mutabilis. Haemolysis by the crude venom was prevented by Ca2+, Ba2+ and Cu2+ treatment, and to a minor extent by Mg2+ and K+. Papain and PEG with a molecular mass exceeding 1000 Da also prevented haemolysis. These findings are consistent with a pore-forming mechanism of crude venom in erythrocytes rather than an oxidative damage at the employed doses.


Subject(s)
Anthozoa/chemistry , Anthozoa/cytology , Cnidarian Venoms/pharmacology , Hemolysis/drug effects , Peptide Hydrolases/metabolism , Animals , Antioxidants/pharmacology , Cations/pharmacology , Dose-Response Relationship, Drug , Erythrocytes/drug effects , Humans , Metals/pharmacology , Molecular Weight , Osmolar Concentration , Polyethylene Glycols/pharmacology
7.
Article in English | MEDLINE | ID: mdl-18619552

ABSTRACT

The haemolytic power of isolated nematocysts from the scyphozoan Pelagia noctiluca was studied with attention to the effect of osmotic protectants as carbohydrates at different MW, cations as Mg2+, Ca2+, Ba2+,Cu2+, K+; proteases as collagenase, trypsin, alpha-chymotrypsin, papain; and antioxidants. Crude venom was at first obtained by sonication of holotrichous-isorhiza nematocysts previously isolated from oral arms of P. noctiluca and then haemolytically tested upon human erythrocytes. Osmotic protectants were effective in inhibiting the haemolytic power depending on their molecular weight so that total inhibition of crude venom-induced haemolysis was observed after PEG treatment (polyethyleneglycol 6000Da). Amongst divalent cations only Ba2+ and Cu2+ significantly inhibited the haemolytic power of crude venom. Proteases seem not to alter the haemolytic activity while antioxidant compounds only slightly reduced the haemolytic power. Such findings may suggest a pore-forming mechanism for P. noctiluca crude venom rather than an oxidative damage to the cell membrane.


Subject(s)
Cnidarian Venoms/pharmacology , Hemolysis/drug effects , Scyphozoa/metabolism , Animals , Antioxidants/pharmacology , Cations/pharmacology , Edetic Acid/pharmacology , Erythrocytes/cytology , Erythrocytes/drug effects , Humans , Osmosis/drug effects , Peptide Hydrolases/pharmacology , Protective Agents/pharmacology , Scyphozoa/cytology , Scyphozoa/enzymology
8.
J Appl Microbiol ; 105(5): 1694-702, 2008 Nov.
Article in English | MEDLINE | ID: mdl-19149767

ABSTRACT

AIMS: In this study, we evaluated the removal efficiency of fuel hydrocarbons from a jet fuel contaminated area using bioaugmentation treatment in biopile. METHODS AND RESULTS: The hydrocarbon analysis of the sample revealed total hydrocarbons mainly constituted by benzene, toluene, ethylbenzene, xylenes (BTEX) and heavy aliphatic hydrocarbons. Enrichments of soil sample were performed with BTEX, pristane and fuel JP-5, respectively, selected hydrocarbon-degrading strains, namely Acinetobacter sp., Pseudomonas sp. and Rhodococcus sp. Three hundred litres of culture containing 10(8) cell ml(-1) of each strain and nutrients sprayed on the biopile allowed a removal of 90% of total hydrocarbons in 15 days. Bioremediation process was monitored by observation of the respiration rate and the bacterial abundance and GC-MS analysis. CONCLUSIONS: The efficiency of the treatment in the biopile was considerable. The assessment of microbial activity during the experiment is necessary for interventions targeted to improve environmental parameters such as humidity, temperature, pH and nutrients for optimization of the bioremediation process. SIGNIFICANCE AND IMPACT OF THE STUDY: A better knowledge of microbial successions at oil-polluted sites is essential for environmental bioremediation. Data obtained in biopile study improve our understanding of processes occurring during oil pollution.


Subject(s)
Bacteria/metabolism , Environmental Restoration and Remediation/methods , Hydrocarbons/metabolism , Soil Microbiology , Soil Pollutants/metabolism , Bacteria/growth & development , Benzene/metabolism , Benzene Derivatives/metabolism , Biodegradation, Environmental , Colony Count, Microbial/methods , Respiration , Toluene/metabolism , Xylenes/metabolism
9.
Cell Mol Biol (Noisy-le-grand) ; 53 Suppl: OL994-1002, 2007 Sep 17.
Article in English | MEDLINE | ID: mdl-17877913

ABSTRACT

We have firstly investigated the toxicological activity by hemolytic assay of crude extract obtained by sonication of holotrichous isorhiza isolated nematocysts of the Scyphozoan Pelagia noctiluca, collected in the Strait of Messina. The hemolytic activity was both time- and dose-dependent on fish, rabbit, chicken and human red blood cells. At lowest doses rabbit and chicken erythrocytes were the most sensitive, whereas those of eel were the most resistant to the crude extract. Different storage conditions, such as -20 degrees C, -80 degrees C for up to 6 months and lyophilization, did not affect the stability of crude venom. Moreover, neither treatment at 4 degrees C, 20 degrees C and 37 degrees C for different time periods ranging between 30 min and 24 h, nor harsh thermal treatment at 80 degrees C and 100 degrees C affected the hemolytic power. The crude venom resulted even stable towards proteolysis and alkaline pH values.


Subject(s)
Cnidaria , Cnidarian Venoms , Animals , Cnidaria/chemistry , Cnidaria/cytology , Cnidarian Venoms/chemistry , Cnidarian Venoms/isolation & purification , Cnidarian Venoms/metabolism , Cnidarian Venoms/toxicity , Erythrocytes/drug effects , Hemolysis , Humans , Temperature
10.
Comp Biochem Physiol A Mol Integr Physiol ; 147(1): 196-204, 2007 May.
Article in English | MEDLINE | ID: mdl-17289416

ABSTRACT

Cell volume regulation has not been completely clarified in Coelenterates. The present investigation focuses on cell volume regulation under anisosmotic conditions, both hyposmotic and hypertonic, and on the underlying signals in nematocytes isolated from the Coelenterate Aiptasia mutabilis living in sea water. Nematocytes, once isolated from acontia, that were submitted to either hyposmotic (35%) and hypertonic shock (45%) show RVD and RVI capabilities, respectively. In order to ascertain the role of Ca2+ in triggering such regulatory mechanisms and the possible involvement of cytoskeleton components, tests were performed by employing either Ca2+ free conditions, Gd3+ as Ca2+ channel blockers, TFP as calmodulin inhibitor, colchicine as microtubule inhibitor and cytochalasin B as microfilament polymerization inhibitor. Results show that isolated nematocytes of A. mutabilis can regulate their volume upon both hyposmotic and hypertonic challenge. Ca2+ both from external medium and from internal stores is needed to perform RVD mechanisms, whereas, intracellular Ca2+ seems to be mainly involved in RVI. Moreover cytoskeletal components may play an important role since a significant RVD and RVI inhibition was observed in treated cells. On the basis of our observations further studies are warranted to further verify the role of signals, including phosphatases and phosphorylases, in cell volume regulation of primitive eukaryotic cells.


Subject(s)
Anthozoa/cytology , Calcium Signaling , Cell Size , Cytoskeleton/metabolism , Animals , Anthozoa/drug effects , Calcium/pharmacology , Calcium Signaling/drug effects , Cell Separation , Cell Size/drug effects , Cytoskeleton/drug effects , Hypertonic Solutions/pharmacology , Osmotic Pressure/drug effects , Seawater , Trifluoperazine/pharmacology
11.
Cell Mol Biol (Noisy-le-grand) ; 50 Online Pub: OL533-42, 2004.
Article in English | MEDLINE | ID: mdl-15555418

ABSTRACT

Nematocytes, Cnidarians stinging cells used primarily in capturing prey or in turning away predators, can regulate their volume under 35% hyposmotic shock showing regulatory volume decrease (RVD). In this study, for the first time, we investigate the capability of nematocytes to regulate their volume under hypertonic conditions, through regulatory volume increase (RVI). The experiments were carried out in acontial nematocytes of Aiptasia diaphana (Cnidaria: Anthozoa) isolated by the chemical method of applying 605 mM SCN-. Channel inhibitors, as amiloride, Gd3+, NPPB, DIDS, bumetanide and ion substitution have been employed to assess the role of ions in such volume regulation mechanisms. Our results suggest that nematocytes are able to perform RVI. The regulatory volume recovery process after hypertonic stimulation involves Na+ conductance and Na+/K+/2Cl- cotransport but not Cl- conductive pathways. Further studies will be necessary to better define such mechanisms and RVI control signalling, taking into account that the nematocyte is known to be a very primitive eukaryotic cell.


Subject(s)
Anthozoa/cytology , Anthozoa/physiology , Animals , Cell Size/drug effects , Hypertonic Solutions/pharmacology , Ion Channels/antagonists & inhibitors , Osmolar Concentration , Osmotic Pressure , Temperature
12.
Cell Mol Biol (Noisy-le-grand) ; 47 Online Pub: OL105-14, 2001.
Article in English | MEDLINE | ID: mdl-11936854

ABSTRACT

This paper examines the morphological characteristics and response to hyposmotic shock of nematocytes isolated by heat dissociation at 45 degrees C for 20 min from the tentacles of Aiptasia diaphana, an anthozoan living in the brackish water of Lake Faro (Messina, Italy). Morphological characteristics were evaluated by scanning electron microscopy (SEM) observations and cytological test, functional characteristics by exposure to 35% hyposmotic stress. 81% of the population of isolated nematocytes had ciliary protrusions. Microbasic-mastigophore and amastigophore nematocytes had a hair bundle at the crown shaped apex composed of ciliary protrusions of different heights and diameters. In basitrichs, instead, a single ciliary protrusion was observed. Following exposure to 35% hyposmotic shock, nematocytes isolated by heat dissociation did not show RVD, while, following treatment with 1 microM and 2 microM gramicidin-S, activation of volume regulation in conditions of hyposmoticity was observed. The effect of gramicidin was concentration-dependent and confirmed the relevant role of conductance to K+ in volume regulation, as previously described (17) on nematocytes isolated by chemical methods.


Subject(s)
Cnidaria/cytology , Animals , Cell Separation , Cell Size/drug effects , Cilia/ultrastructure , Cnidaria/drug effects , Cnidaria/ultrastructure , Gramicidin/pharmacology , Hot Temperature , Microscopy, Electron, Scanning , Osmotic Pressure , Quinine/pharmacology
13.
Cell Mol Biol (Noisy-le-grand) ; 45(2): 249-58, 1999 Mar.
Article in English | MEDLINE | ID: mdl-10230735

ABSTRACT

Regulatory volume decrease (RVD) and the mechanisms of its regulation were investigated in microbasic mastigophore nematocytes isolated from the acontia of Aiptasia diaphana (Coelenterates, Cnidaria), a marine species that can be exposed to considerable changes in osmotic pressure. Exposure of isolated cells to a 35% hypoosmotic shock lead to the expected osmotic swelling followed by a rapid RVD. RVD was blocked if Ca2+ influx was prevented either by applying a Ca2+-free medium or by treating the cells with Gd3+. Furthermore, the calmodulin action inhibitor trifluoperazine (TFP), prevented RVD and also caused a larger swelling than that induced by preventing Ca2+ influx. Treatment of nematocytes with quinine completely blocked the RVD. Such an effect was prevented by gramicidine. A partial inhibition of RVD was caused by treatment with 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS). It is concluded that: i) the nematocytes regulate volume under hypoosmotic shock; ii) the regulatory mechanisms consist mainly in increased conductance to K+, and consequently, of Cl-, and, to a lesser extent, in H+/K+-Cl-/HCO3- exchange, and iii) the ionic fluxes are triggered by increased [Ca2+]i with the possible involvement of calmodulin.


Subject(s)
Sea Anemones/cytology , 4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid/pharmacology , Animals , Cell Size/drug effects , Osmotic Pressure , Quinine/pharmacology
14.
J Exp Biol ; 187: 201-6, 1994 Feb.
Article in English | MEDLINE | ID: mdl-7523564

ABSTRACT

The activation properties of in situ nematocytes of Pelagia noctiluca (Scyphozoa) were investigated by physical contact with a gelatin probe that, besides stimulating the nematocyte battery, retains the discharged nematocysts, thereby allowing a quantitative evaluation of the response. In oral arms previously treated with 2 mmol l-1 La3+ the discharge was inhibited. This result confirms the Ca(2+)-dependence of nematocyte activation. A similar inhibitory effect was induced by treatment with 20 mumol l-1 Gd3+, a powerful blocker of mechanosensitive ion channels. It is therefore proposed that Ca(2+)-permeable mechanosensitive channels are involved in the activation of nematocytes. 50 mumol l-1 Gd3+ added to the gelatin probe was effective in otherwise untreated oral arms. This result suggests that Gd3+ could be useful in preventing stings from harmful Cnidaria.


Subject(s)
Gadolinium/pharmacology , Scyphozoa/drug effects , Animals , Calcium/physiology , Ion Channels/drug effects , Mechanoreceptors/drug effects , Mechanoreceptors/physiology , Scyphozoa/physiology
17.
J Submicrosc Cytol ; 15(4): 929-40, 1983 Oct.
Article in English | MEDLINE | ID: mdl-6655769

ABSTRACT

The ultrastructural changes of the plantaris muscle of the rat have been investigated during long-term compensatory hypertrophy. The latter was induced by the removal of the synergistic gastrocnemius muscle. Transmission electron microscope (TEM) observations were performed on the 20th, 40th and 60th days after surgery on overloaded and control muscles. The plantaris muscle had hypertrophied 54.8% after 20 days, 74.4% after 40 days and 79.8% after 60 days. It was observed that activation of the satellite cell developed as shown by an increase in cytoplasmic volume, together with diffuse presence of polyribosomes and a rough endoplasmic reticulum. On the 40th day masses of swollen mitochondria grouped at the edge of muscle fibers were observed. On the 60th day structures completely covered with basal lamina, whose cytoplasm was filled with mitochondria and polyribosomes, were partially detached from the fibers. The above ultrastructural changes were absent in control contralateral muscles. These findings suggest that surgically induced overload produces a relevant ultrastructural re-arrangement in muscle tissue.


Subject(s)
Muscles/ultrastructure , Animals , Hypertrophy , Male , Muscles/pathology , Rats , Rats, Inbred Strains
18.
Med Sci Sports Exerc ; 12(4): 268-73, 1980.
Article in English | MEDLINE | ID: mdl-7421477

ABSTRACT

Morphological changes exhibited by satellite cells during compensatory hypertrophy have been observed through a scanning electron microscope on m. plantaris of young, adult rats. Compensatory hypertrophy was induced by ablation of the synergistic m. gastrocnemius. Muscles were observed 15, 30, and 60 days post-operative. A consistent increase in wet-weight of m. plantaris (60.3,77.2, and 93.7% more than the contralateral control muscle) indicated the degree of developing hypertrophy. The satellite cells exhibited the following successive changes: (1) cells enlarged and became freed of connective network sheath, (2) cell distance from the associated fibers increased though still attached to the latter, (3) subsequent cell division, giving rise to rows of cells, that with time-lapse formed elongated structures with a common sheath, (4) elongated structures developed into new muscle fibers.


Subject(s)
Muscles/ultrastructure , Animals , Hypertrophy/physiopathology , Male , Microscopy, Electron, Scanning , Muscles/pathology , Myofibrils/ultrastructure , Organ Size , Rats
19.
Differentiation ; 15(2): 119-25, 1979.
Article in English | MEDLINE | ID: mdl-527773

ABSTRACT

Muscle fibrillation has been suggested as a possible trigger for activation of satellite cells, a well known phenomenon associated with denervation. In order to test such a hypothesis fibrillation has been induced in normally innervated muscles by chronic administration of neostigmine and the response of satellite cells has been observed with a scanning electron microscope. The results show that satellite cells protrude from the profile of the muscle fiber, become partially separated from the latter, and align in rows. Elongated structures and presumable new muscle fibers are observed after 14 days of treatment. It is concluded that the overactivity of muscle fibers which is induced during fibrillation causes activation and differentiation of satellite cells. This result is consistent with that of a previous experiment showing that satellite cells are activated during acute increase in workload.


Subject(s)
Muscle Contraction , Muscles/cytology , Neostigmine/pharmacology , Animals , Cell Fusion , Male , Muscles/drug effects , Myofibrils/ultrastructure , Rats
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