1,720,977 research outputs found
The effect of physical activity on managing symptoms of attention deficit hyperactivity disorder (ADHD) in adults - a literature review
No full textUvod: Motnja pozornosti in hiperaktivnosti (ADHD) je označena kot najpogostejša nevrološka razvojna motnja v otroštvu, za katero so značilni simptomi pomanjkanja pozornosti, hiperaktivnost in impulzivnost v različni meri. Sprva je veljalo, da gre za izključno otroško bolezen, danes pa vemo, da se v približno 50 % primerov nadaljuje v odraslo dobo in vpliva na vsakdanje delovanje posameznikov. Zdravljenje običajno vključuje farmakološke metode, ki pa lahko povzročajo različne neželene duševne in telesne stranske učinke. Telesna dejavnost je zato priporočljiva metoda za lajšanje simptomov in zmanjšanje potrebe po zdravilih. Namen: Namen diplomskega dela je bil pregledati strokovno literaturo in ugotoviti, ali ima telesna dejavnost pomemben vpliv na počutje, delovanje in simptome ADHD pri odraslih. Metode dela: Iskanje strokovne in znanstvene literature je potekalo s pomočjo podatkovnih zbirk PubMed in Cochrane Library z uporabo ključnih besed ADHD, exercise in adult. V pregled literature so bile vključene prosto dostopne raziskave v angleškem jeziku z ADHD ali attention deficit hyperactivity disorder v naslovu. Raziskave so ocenjevale takojšnje in dolgoročne učinke telesne vadbe z različnimi metodami – vprašalniki, kognitivne naloge, slikanje z magnetno resonanco ipd. Rezultati: V pregled je bilo vključenih 8 raziskav, ki so preučevale vpliv različnih vrst telesne vadbe (najpogosteje aerobna vadba in joga) na odrasle z ADHD, stare med 18 in 39 let. Za oceno so bile uporabljene kognitivne naloge, vprašalniki in različne fiziološke meritve. Vadba je po večini pokazala pozitiven vpliv na pozornost in impulzivnost. Aerobna vadba, kot je kolesarjenje ali hoja, je v več raziskavah prispevala k izboljšanju reakcijskega časa preiskovancev, zmanjšala variabilnost odzivov in povečala aktivnost v možganskih regijah, povezanih z izvršilnimi funkcijami. Ponekod se je izboljšalo tudi razpoloženje, povečala motivacija za kognitivne naloge in zmanjšala utrujenost. Po drugi strani pa učinki vadbe na motorično impulzivnost in hiperaktivnost niso bili enotni, in sicer večina raziskav na teh področjih ni zaznala posebnih sprememb pri preiskovancih. Vseeno pa so bili učinki po večini majhni in kratkotrajni ter so se razlikovali glede na vrsto vadbe, metode merjenja in značilnosti udeležencev, kar omejuje možnost zanesljive posplošitve rezultatov. Razprava in zaključek: Pregled literature je pokazal, da lahko telesna vadba, predvsem aerobna, pozitivno vpliva na simptome ADHD pri odraslih, predvsem na pozornost in impulzivnost. Vpliv na hiperaktivnost in druge simptome ni bil dosleden. Telesna vadba ima tako potencial kot dopolnilni pristop k zdravljenju ADHD, vendar so za zanesljivejše zaključke potrebne dodatne raziskave z enotnejšo metodologijo in spremljanjem dolgoročnih učinkov.Introduction: Attention deficit hyperactivity disorder (ADHD) is recognized as the most common neurodevelopmental disorder in childhood, characterized by varying degrees of inattention, hyperactivity, and impulsivity. Initially considered a childhood-only condition, it is now known that in approximately 50% of cases, ADHD continues into adulthood and affects individuals\u27 daily functioning. Treatment usually involves pharmacological approaches, which may cause various unwanted psychological and physical side effects. Physical activity is therefore recommended as a method to alleviate symptoms and reduce the need for medication. Purpose: The purpose of this thesis was to review the professional literature and determine whether physical activity has a significant impact on well-being, functioning, and ADHD symptoms in adults. Methods: The search for professional and scientific literature was conducted using the PubMed and Cochrane Library databases with the keywords ADHD, exercise, and adult. The literature review included open-access studies in English with ADHD or attention deficit hyperactivity disorder in the title. The studies evaluated immediate and long-term effects of physical exercise using various methods – questionnaires, cognitive tasks, magnetic resonance imaging, etc. Results: Eight studies were included in the review, investigating the effects of different types of physical activity (most commonly aerobic exercise and yoga) on adults with ADHD aged between 18 and 39 years. The studies used cognitive tasks, questionnaires, and various physiological measurements. Most exercises showed a positive effect on attention and impulsivity. Aerobic exercises such as cycling or walking contributed in several studies to improved reaction time, reduced response variability, and increased activation in brain regions associated with executive functioning. In some cases, improvements were also observed in mood, motivation for cognitive tasks, and reduced fatigue. On the other hand, the effects of exercise on motor impulsivity and hyperactivity were inconsistent, with most studies in these areas not reporting significant changes in participants. Nevertheless, the observed effects were mostly small and short-term, varying depending on the type of exercise, measurement methods, and participant characteristics, which limits the possibility of reliably generalizing the results. Discussion and Conclusion: The literature review indicated that physical activity, especially aerobic exercise, can have a positive effect on ADHD symptoms in adults, particularly in terms of attention and impulsivity. The impact on hyperactivity and other symptoms was not consistent. Physical activity thus holds potential as a complementary approach to ADHD treatmenthowever, further research with more standardized methodologies and long-term follow-ups is needed for more reliable conclusions
Physiotherapy treatment of a patient following multiple anterior shoulder dislocations and arthroscopic stabilization of a Perthes lesion: a case report
No full textUvod: Večkratni sprednji izpah ramenskega sklepa povzroči bolezenske spremembe, ki vplivajo na funkcionalnost in stabilnost sklepa. Perthesova lezija je oblika Bankartove lezije, pri kateri pride do nepopolne avulzije sprednjega dela labruma brez njegovega premika, z medialno zavihano in nepoškodovano pokostnico. Privede lahko do ponavljajoče nestabilnosti in pogosto zahteva operativno zdravljenje, najpogosteje z artroskopsko stabilizacijo po Bankartu. Primerna fizioterapevtska obravnava je ključna za obnovitev funkcije ramenskega sklepa in varno vrnitev v športne aktivnosti, smernice optimalne obravnave pa v literaturi niso enotne. Namen: Namen diplomskega dela je predstaviti fizioterapevtsko obravnavo pacienta po artroskopski stabilizaciji Perthesove lezije zaradi večkratnega sprednjega izpaha ramenskega sklepa. Cilj je oceniti uspešnost obravnave s primerjavo rezultatov fizioterapevtskega pregleda pred in po obravnavi ter ovrednotiti pripravljenost pacienta za vrnitev v šport po zaključeni fizioterapiji. Metode dela: Diplomsko delo je poročilo o primeru pacienta, ki je v štirimesečnem obdobju opravil 20 obiskov. Pred začetkom obravnave smo izvedli fizioterapevtski pregled, ki je zajemal inspekcijo, palpacijo, goniometrične meritve gibljivosti, ročne dinamometrije mišic ramenskega sklepa, oceno intenzivnosti bolečine in oceno vpliva nestabilnosti na kakovost življenja pacienta. Pregled smo ponovili po fizioterapevtski obravnavi, ko smo izvedli tudi skupino testov za ocenjevanje pripravljenosti pacienta za vrnitev v šport. Rezultati: Po zaključeni fizioterapiji je aktivna in pasivna gibljivost ramenskega sklepa primerljiva z nasprotnim zgornjim udom. Maksimalna hotena sila izometrične kontrakcije vseh testiranih mišičnih skupin se je povečala za od 36 % do 95 %. Dosegli smo stanje brez bolečin v ramenskem sklepu, izboljšana funkcija zgornjega uda pa je izboljšala kakovost življenja pacienta. Rezultati skupine testov so pokazali, da je pacient s psihološkega vidika, z vidika dinamičnega ravnotežja in stabilnosti zgornjega uda, vzdržljivosti mišic in sposobnosti razvijanja sile pripravljen za postopno vrnitev v športne aktivnosti. Razprava in zaključek: Bili smo uspešni pri doseganju vseh zastavljenih ciljev fizioterapevtske obravnave. Pacient je na podlagi rezultatov skupine testov pripravljen za postopno vrnitev k športnim aktivnostim. Čeprav literatura glede protokola obravnave po artroskopski stabilizaciji sprednjega labruma ni soglasna, sestavljeni načrt fizioterapije, ki je privedel do uspešne rehabilitacije potrjuje pomembnost individualizacije programa in sprotnega prilagajanja fizioterapevtskih intervencij. Rezultati potrjujejo, da je bil fizioterapevtski program je bil strokovno utemeljen, učinkovit in dobro izveden.Introduction: Multiple anterior dislocations of the shoulder joint cause pathological changes that can affect the functionality and stability of the joint. A Perthes lesion is a form of a Bankart lesion in which there is an incomplete avulsion of the anterior labrum without its displacement, with a medially lifted and intact periosteum. It can lead to recurrent instability and often requires surgical treatment, most often with the Arthroscopic Bankart Repair. Appropriate physiotherapy treatment is essential for restoring shoulder joint function and a safe return to sporting activities. The guidelines for optimal management, however, are not consistent in the literature. Purpose: The purpose of this diploma work is to present the physiotherapy treatment of a patient following multiple anterior shoulder dislocations and an arthroscopic stabilisation of a Perthes lesion. The goal is to evaluate the effectiveness of the physiotherapy treatment by comparing the results of the physiotherapy assessment before and after the treatment and to assess the patient\u27s readiness to return to sport after physiotherapy. Methods: The diploma work is a case report of a patient who underwent 20 therapy sessions over a four month period. Before the treatment began, a physiotherapy assessment was conducted, which included inspection, palpation, goniometric measurements of mobility, hand-held dynamomety of muscles of the shoulder joint, pain intensity assessment, and an evaluation of the impact of instability on the patient\u27s quality of life. The assessment was repeated after physiotherapy, at which point a battery of tests was also performed to evaluate the patient\u27s readiness to return to sports. Results: After completing the physiotherapy treatment, both active and passive shoulder joint mobility were comparable to the contralateral upper limb. The maximum voluntary isometric contraction of all tested muscle groups increased by 36% to 95%. We achieved a pain-free state in the shoulder joint and the improved function of the upper limb enhanced the patient\u27s quality of life. The results of the battery of tests showed that the patient is ready for a gradual return to sports activities from a psychological perspective, in terms of dynamic balance and stability of the upper limb, muscle endurance and the ability to develop force. Discussion and conclusion: We were successful in achieving all the set goals of the physiotherapy treatment. Based on the results of the battery of tests, the patient is ready for a gradual return to sports activities. Although the literature on the post-arthroscopic anterior labrum stabilization protocol is not unanimous, the structured physiotherapy plan that led to successful rehabilitation confirms the importance of individualizing the program and continuously adapting physiotherapy interventions. The results confirm that the physiotherapy program was thoughtfully and correctly structured and effectively implemented
Effect of resistance exercise in elderly people with sarcopenia and osteoporosis - literature review
No full textUvod: Sarkopenija in osteoporoza sta bolezni, ki se pogosto pojavljata pri starejših odraslih in lahko privedeta do resnih zdravstvenih težav ter predstavljata veliko ekonomsko breme za zdravstveni sistem po vsem svetu. Soobstoj sarkopenije in osteoporoze je opisan kot osteosarkopenija. Posledice za posameznika, ki trpi za obema boleznima, vključujejo večje tveganje za padce, zlome, institucionalizacijo in umrljivost. Telesna dejavnost v kombinaciji s prehranskimi dodatki ugodno vpliva na simptome sarkopenije in osteoporoze ter izboljša kakovost življenja starejših odraslih. Namen: Namen diplomskega dela je bil s pomočjo pregleda strokovne literature ugotoviti vpliv telesne vadbe proti uporu na preprečevanje in zdravljenje osteosarkopenije pri starejših odraslih. Metode dela: Iskanje strokovne in znanstvene literature je potekalo v podatkovnih zbirkah PubMed/Medline in BioMed Central z uporabo naslednjih ključnih besed v angleškem jeziku »resistance training AND ((sarcopenia AND osteoporosis) OR osteosarcopenia)) AND elderly«. Pri iskanju smo uporabili časovni okvir od leta 2013 do 2023. Kakovost člankov smo metodološko ocenili po PEDro lestvici. Rezultati: Na podlagi vključitvenih meril so bile v podrobnejši pregled literature vključene tri randomizirane nadzorovane raziskave ter ena presečna raziskava. Vadbeni programi v analiziranih raziskavah so vključevali telesno vadbo proti uporu izključno na napravah ter aerobno in kombinirano vadbo. V vseh štirih analiziranih raziskavah je prišlo do statistično značilnega izboljšanja funkcijskih parametrov, povezanih s sarkopenijo in osteoporozo oziroma osteosarkopenijo. Razprava in zaključek: S sistematičnim pregledom literature smo ugotovili, da imajo različne oblike telesne vadbe pozitivne učinke na izboljšanje ali vzdrževanje simptomov pri starejših odraslih s sarkopenijo in osteoporozo. Pokazalo se je, da z telesno vadbo proti uporu preprečimo, ali vsaj upočasnimo, poslabšanje simptomov sarkopenije in osteoporoze ter da ima vadba ugodne učinke na izboljšanje mišične mase, mišične moči, telesne zmogljivosti in mineralne kostne gostote pri starejših posameznikih. Smiselne bi bile nadaljnje raziskave o dolgoročnih učinkih telesne vadbe proti uporu na simptome sarkopenije in osteoporoze ter vpliv telesne vadbe proti uporu na mineralno kostno gostoto pri osebah moškega spola.Introduction: Sarcopenia and osteoporosis are diseases commonly observed in older adults, which can lead to serious health issues and represent a significant economic burden on healthcare systems worldwide. The coexistence of sarcopenia and osteoporosis is described as the osteosarcopenia. Consequences for individuals suffering from both conditions include an increased risk of falls, fractures, institutionalization, and mortality. Physical activity combined with dietary supplements has a beneficial effect on sarcopenia and osteoporosis symptoms and improves the quality of life in older adults. Purpose: The aim of this thesis was to determine the effectiveness of resistance exercise in preventing and treating osteosarcopenia in older adults through a review of scientific literature. Methods: The search for scientific literature was conducted in the PubMed/Medline and BioMed Central databases using the following English keywords: "resistance training AND ((sarcopenia AND osteoporosis) OR osteosarcopenia)) AND elderly." The search covered the period from 2013 to 2023. The methodological quality of the articles was assessed using the PEDro scale. Results: Based on the inclusion criteria, three randomized controlled trials and one cross-sectional study were included in the detailed literature review. The exercise programs in the analysed studies included resistance training exclusively on machines, as well as aerobic and combined exercise. In all four analysed studies, there was a statistically significant improvement in functional parameters related to sarcopenia, osteoporosis, and osteosarcopenia. Discussion and conclusion: Through a systematic review of the literature, we found that various forms of physical exercise have positive effects on improving or maintaining symptoms in older adults with sarcopenia and osteoporosis. Resistance exercise has been shown to prevent or at least slow down the worsening of sarcopenia and osteoporosis symptoms and has beneficial effects on improving muscle mass, muscle strength, physical performance, and bone mineral density in older adults individuals. Further research on the long-term effects of resistance exercise on the symptoms of sarcopenia and osteoporosis, as well as the impact of resistance exercise on bone mineral density in male subjects, would be meaningful
The effect of preferred and non-preferred music on muscle performance - literature review
No full textUvod: Vadba proti uporu je nujno potrebna za razvoj in ohranjanje mišične mase, jakosti in vzdržljivosti, vse to pa je pomembno tako v športu kot tudi pri opravljanju vsakodnevnih dejavnosti. Možno je, da poslušanje glasbe pomembno izboljša zmogljivost, a o vplivu glasbe na vadbo za krepitev mišic obstajajo nasprotujoči si dokazi. Namen: Namen diplomskega dela je primerjati učinke zaželene in nezaželene glasbe na posamezne elemente mišične zmogljivosti. S tem bomo ugotovili, na kateri element mišične zmogljivosti ima glasba največji vpliv in kako pomembne so pri tem posameznikove glasbene želje . Metode dela: Literaturo smo iskali v podatkovnih zbirkah PubMed in Web of Science s kombinacijo ključnih besed: (»preferred music« OR »self-selected music« OR »nonpreferred music« OR »motivational music«) AND (»muscle« OR »exercise« OR »strength«). Iskali smo članke v angleškem jeziku, ki so bili objavljeni v zadnjih 15 letih. Kakovost vključenih raziskav smo ocenili s pomočjo lestvice PEDro. Rezultati: Podrobno smo analizirali 12 raziskav. V vseh raziskavah, ki so opazovale učinke glasbe na mišično vzdržljivost, so preiskovanci dosegli značilno večjo mišično vzdržljivost med poslušanjem zaželene glasbe v primerjavi z nezaželeno glasbo (povečanje za 7-41 %) in v primerjavi brez poslušanja glasbe (povečanje za 5-43 %). Rezultati raziskav, ki so opazovale učinke glasbe na mišično jakost in moč, pa so se med seboj precej razlikovali. Poslušanje nezaželene glasbe je samo v eni raziskavi, v kateri so preiskovanci glasbo poslušali samo med ogrevanjem pred izvedbo meritev, privedlo do izboljšanja mišične zmogljivosti v primerjavi s kontrolnim pogojem. Razprava in zaključek: Zaželena glasba najbolj izboljša mišično vzdržljivost, poleg tega pa tudi značilno izboljša motivacijo posameznikov za izvajanje vadbe. Zaželenost glasbe ima pri tem pomembno vlogo, saj do teh izboljšav ni prišlo, ko so preiskovanci poslušali neželeno glasbo. Pregledane raziskave se metodološko precej razlikujejo, kar otežuje primerjanje njihovih rezultatov, poleg tega pa jih je večina le zmerne kakovosti na podlagi ocen PEDro. Za boljše razumevanje učinkov glasbe je treba v prihodnje izvesti več raziskav boljše kakovosti z bolj enotnimi protokoli ter preučiti mehanizme delovanja glasbe.Introduction: Resistance training is essential for the development and maintenance of muscle mass, strength, and endurance, all of which are important in both sport and activities of daily living. It is possible that listening to music significantly improves performance, but conflicting data exist regarding the influence of music on muscle-strengthening exercises. Purpose: The purpose of the diploma thesis is to compare the effects of preferred and non-preferred music on elements of muscle performance. This will help us determine which element of muscle performance is the most influenced by music and how important music preference is in this context. Methods: The literature search was conducted in the PubMed and Web of Science electronic databases using the following keyword combination: (»preferred music« OR »self-selected music« OR »nonpreferred music« OR »motivational music«) AND (»muscle« OR »exercise« OR »strength«). The search was limited to articles in English that were published within the last 15 years. We used PEDro scale for the quality assessment of the included studies. Results: Twelve studies were analysed in the literature review. In all studies that assessed the effects of music on muscular endurance, participants achieved significantly better muscular endurance while listening to preferred music compared to non-preferred music (improvement for 7-41 %) or no music at all (improvement for 5-43 %). Results of the studies which assessed the influence of music on muscle strength and power varied considerably. Only one study showed improvement in muscular performance in the non-preferred music condition compared to no music condition. Discussion and conclusion: Preferred music improves muscle endurance the most and also significantly improves individuals\u27 motivation to exercise. No such improvements were observed when participants listened to non-preferred music, which shows the importance of music preference. Reviewed studies methodologically varied, making it difficult to compare their results. Most of the reviewed studies are only fair quality according to PEDro score. Future research should conduct more high-quality studies with more unified protocols for better understanding of the effects of music on muscle performance and its underlying mechanisms
Effects of dry needling in the relief of temporomandibular joint pain - literature review
No full textUvod: Temporomandibularne motnje so najpogostejši vzrok bolečine v področju obraza. Prizadenejo čeljustni sklep in okoliške mišično-skeletne strukture. Najpogostejši znaki in simptomi so bolečina, omejena gibljivost in zvoki med gibanjem čeljusti. Konzervativno zdravljenje vključuje izobraževanje oziroma kognitivno-vedenjsko terapijo, farmakoterapijo, razbremenilne grizne opornice in fizioterapijo. Če konzervativne oblike terapije niso učinkovite, se lahko izvede tudi kirurško zdravljenje. Ena izmed fizioterapevtskih tehnik lajšanja miofascialne bolečine je suho iglanje, pri katerem se igle brez uporabe anestezije vstavijo neposredno v miofascialne prožilne točke. Namen: Namen diplomskega dela je bil pregledati strokovno in znanstveno literaturo ter analizirati učinke suhega iglanja na bolečino v področju čeljustnega sklepa. Metode dela: Iskanje literature je potekalo v spletnih podatkovnih zbirkah PubMed, PEDro, Cochrane Library, BASE in DiKUL. Uporabljene so bile besedne zveze v angleškem jeziku: »temporomandibular disorders« OR »temporomandibular joint« AND »dry needling«. V pregled so bile vključene prosto dostopne raziskave v angleškem jeziku, objavljene po letu 2000, v katerih so sodelovali preiskovanci s temporomandibularnimi motnjami, v katerih so pri vsaj eni skupini izvajali suho iglanje in v katerih je bil eden izmed izidov vpliv terapije na bolečino. Vključene so bile tako raziskave, v katerih so raziskovalci ugotavljali takojšnje učinke suhega iglanja, kot tudi raziskave, v katerih so spremljali dolgotrajne učinke. Rezultati: Pregledanih in analiziranih je bilo devet raziskav. V sedmih raziskavah so učinke suhega iglanja primerjali z drugimi terapijami oziroma s kontrolno skupino, medtem ko so v dveh raziskavah suho iglanje kombinirali z drugimi intervencijami in te kombinacije primerjali z različnimi terapijami. V vseh pregledanih raziskavah je suho iglanje značilno zmanjšalo povprečno intenziteto bolečine (p < 0,05), in sicer za od 1,86 do 7,07 enot po VAL oziroma za povprečno 2,52 enot po ŠLB. V šestih raziskavah je suho iglanje značilno izboljšalo tudi obseg depresije čeljusti. Razprava in zaključek: S sistematičnim pregledom literature smo ugotovili, da lahko suho iglanje učinkovito zmanjša bolečino in vpliva na izboljšanje obsega giba. V večini raziskav razlike v zmanjšanju bolečine po VAL med suhim iglanjem in primerjalnimi terapijami niso bile klinično pomembne. Ker so bili v vseh raziskavah opazovani le kratkoročni učinki suhega iglanja, bi bile potrebne nadaljnje raziskave z večjim številom preiskovancev, bolj homogenimi postopki in daljšim sledenjem rezultatov. Najboljše rezultate dosežemo, če suho iglanje kombiniramo z drugimi fizioterapevtskimi postopki.Introduction: Temporomandibular disorders are the most common cause of orofacial pain. They affect the temporomandibular joint and surrounding musculoskeletal structures. The most common signs and symptoms include pain, limited mandibular range of motion and joint noises. Conservative treatment includes education or cognitive behavioural therapy, pharmacotherapy, interocclusal splint therapy and physiotherapy. If conservative methods are not effective, various surgical procedures can be considered. One of the physiotherapy techniques for alleviating myofascial pain is dry needling, in which needles are inserted directly into the myofascial trigger points without the use of anesthesia. Purpose: The purpose of the diploma work was to review published professional and scientific literature and to analyze the effects of dry needling on temporomandibular joint pain. Methods: A literature search was conducted online in the PubMed, PEDro, Cochrane Library, BASE and DiKUL databases. Combinations of phrases in English were used: »temporomandibular disorders« OR »temporomandibular joint« AND »dry needling«. Studies with open access, published after the year 2000, involving participants with temporomandibular disorders, where dry needling was performed in at least one experimental group, and where one of the outcomes was the effect of therapy on pain intensity, were included in the review. Both studies that investigated the immediate effects of dry needling and studies that monitored the long-term effects were included. Results: Nine studies were reviewed and analyzed. In seven studies, dry needling was compared with other therapies or control groups, while in two studies, combinations of dry needling and other interventions were compared to various therapies. In all reviewed studies, dry needling significantly reduced the average pain intensity (p < 0,05), with an reduction of 1,86 to 7,07 units on the VAS, or an average reduction of 2,52 units on the NPRS. In six studies, dry needling also significantly improved the mouth opening range. Discussion and conclusion: A systematic review of the literature revealed that dry needling can effectively reduce pain and improve mandibular range of motion. In most studies, the differences in pain reduction on the VAS between dry needling and comparative therapies were not clinically significant. However, since all reviewed studies observed only short-term effects of dry needling, further research with larger sample sizes, more homogeneous procedures and longer follow-up of results would be necessary. The best results are achieved when dry needling is combined with other physiotherapy procedures
The effect of glucose metabolism disorder on capillary network and myosin heavy chain expression in skeletal muscles of mice
No full textUvod: Presnovne motnje, povezane z debelostjo, so eden glavnih vzrokov obolevnosti in umrljivosti v razvitem svetu. Strukturne in funkcionalne spremembe v skeletnih mišicah in kapilarni mreži so pomembno povezane z mehanizmi zmanjšane občutljivosti na inzulin zaradi debelosti. V poznih fazah debelosti je številska gostota počasnih, oksidativnih, na inzulin občutljivih mišičnih vlaken manjša zaradi pretvorbe v hitra, na inzulin manj občutljiva vlakna. Tudi kopičenje znotrajceličnih lipidnih kapljic v mišičnih vlaknih lahko prispeva k zmanjšanju odzivnosti na inzulin, ni pa še znano, kako sta kopičenje znotrajceličnih lipidnih kapljic in pretvorba med tipi mišičnih vlaken povezana. Pri napredovani debelosti z zmanjšano občutljivostjo na inzulin se gostota kapilarne mreže v skeletnih mišicah zmanjša, zmanjšata pa se tudi bazalni in z inzulinom spodbujen krvni pretok. V zgodnji fazi debelosti z zmanjšano občutljivostjo na inzulin so ugotovili povečano funkcionalno odzivnost žilja in kapilarne mreže na inzulin. Ali je takšen funkcionalni odziv žilja povezan tudi z morfološkimi spremembami v kapilarni mreži in ali pride do sprememb v številski gostoti različnih tipov mišičnih vlaken tudi v zgodnjih fazah debelosti, še ni pojasnjeno.
Metode: Osemnajst 54 tednov starih miši (linije C57BL/6JOlaHsd) smo razdelili v dve poskusni skupini po devet miši: na debele miši, hranjene s krmo z višjo vsebnostjo maščob, in na vitke miši, hranjene s standardno krmo. Odzivnost na inzulin smo ocenili z oralnim tolerančnim testom za glukozo in meritvami koncentracije krvne glukoze na tešče. Značilnosti kapilarne mreže smo določali s 3D-analizo 100 µm debelih prečnih rezin mišice gluteus maximus. Z imunofluorescenčnimi tehnikami smo označili endotelij kapilar in bazalno membrano kapilar in mišičnih vlaken. Debele prečne rezine smo zajeli s konfokalnim mikroskopom in analizirali s pomočjo programske opreme Ellipse. Izražanje posameznih izooblik težkih verig miozina v zaporednih 10 µm debelih rezinah mišic gluteus maximus, gastrocnemius in plantaris smo ugotavljali s protitelesi proti izooblikam težkih verig miozina tipa 1, 2a, 2x/d in 2b. Primarna protitelesa smo prikazali s posredno imunoperoksidazno metodo. Vsebnost znotrajceličnih lipidov smo določali na 10 µm debelih rezinah mišic gastrocnemius, plantaris in soleus, obarvanih z barvilom Sudan Black B. Indeks vsebnosti lipidov smo izračunali kot stokrat pomnoženo razmerje med površino preseka mišičnega vlakna, ki so ga prekrivale lipidne kapljice, in površino celotnega preseka mišičnega vlakna. S primerjavo premerov mišičnih vlaken mišice gluteus maximus v 10 µm debelih nativnih tkivnih rezinah in v 100 µm debelih fiksiranih in imunofluorescenčno označenih tkivnih rezinah smo ugotavljali, ali se v debelih rezinah mišična vlakna deformirajo tudi v prečni ravnini.
Rezultati: V primerjavi z vitkimi mišmi, hranjenimi s standardno krmo, so imele miši, hranjene s krmo z visoko vsebnostjo maščob, znatno večjo telesno maso (p = 0,0001) in bazalno glikemijo ter znižano toleranco za glukozo (p < 0,05). Gostota kapilarne mreže mišice gluteus maximus je bila pri debelih miših večja kot pri vitkih miših. Okoli majhnih mišičnih vlaken (< 40 µm) smo ugotovili značilno večjo dolžino kapilar na dolžino mišičnih vlaken in dolžino kapilar na površino mišičnih vlaken (p < 0,05), medtem ko se okoli velikih mišičnih vlaken gostota kapilarne mreže ni značilno spremenila. Vijugavost, anizotropija in premer mišičnih vlaken se med poskusnima skupinama niso značilno razlikovali. Pri počasni mišici soleus in hitri mišici gluteus maximus, ki ne nosita telesne teže, smo pri debelih miših ugotovili manjšo številsko gostoto počasnih tipov mišičnih vlaken kot pri vitkih miših (p < 0,05). Pri hitri mišici gastrocnemius in srednje hitri mišici plantaris, ki ne nosita telesne teže, v izražanju težkih verig miozina med poskusnima skupinama nismo ugotovili značilnih razlik. Pri debelih miših sta bila v primerjavi z vitkimi mišmi v hitrih in srednje hitrih mišicah gastrocnemius in plantaris premer mišičnih vlaken in vsebnost znotrajceličnih lipidov znatno večja v mišičnih vlaknih tipa 2a in 2x/d (p < 0,05). Ugotovili smo, da se vzorci debelih prečnih rezin skeletnih mišic med pripravo za konfokalno mikroskopijo v prečni ravnini raztegnejo (p < 0,001), v aksialni smeri pa skrčijo (p < 0,001). Pokazali smo pozitivno korelacijo med velikostjo raztezka v prečni ravnini in obsegom krčenja v aksialni smeri (r = 0,493, p < 0,01), pri čemer je bilo krčenje v aksialni smeri bolj izrazito pri prečno kot pri poševno odrezanih tkivnih rezinah.
Zaključki: Pri debelih miših z zmanjšano občutljivostjo na inzulin se je kapilarna mreža okoli majhnih, bolj oksidativnih tipov mišičnih vlaken povečala, kar bi lahko bil zgodnji kompenzacijski mehanizem proti zmanjšanju odzivnosti na inzulin. Številska gostota hitrih tipov mišičnih vlaken se je povečala tako v počasnih kot tudi v hitrih mišicah, ki ne nosijo telesne teže. Nasprotno pa pri hitrih mišicah, ki nosijo telesno težo, nismo opazili značilnih sprememb v številski gostoti različnih tipov mišičnih vlaken. Iz tega sklepamo, da lahko povečana obremenitev mišic zaradi povečane telesne mase preprečuje nastanek sprememb v izražanju težkih verig miozina. Pri debelih miših je bilo kopičenje znotrajceličnih lipidov različno v različnih mišicah in v različnih tipih mišičnih vlakenvečje kopičenje smo opazili tako v hitrih kot počasnih mišicah, in sicer največje v mišičnih vlaknih tipa 1, 2a in 2x/d. Debele tkivne rezine se raztezajo v prečni ravnini in skrčijo v aksialni smeri, pri čemer je velikost raztezka v prečni ravnini delno odvisna od velikosti skrčenja v aksialni smeri. Deformacijo vzorca v aksialni smeri sicer lahko popravimo s kalibracijo, da pa bi dosegli, da bi bila tudi deformacija v prečni ravnini čim manjša, moramo optimizirati histološke protokole in tako maksimalno zmanjšati krčenje v aksialni ravnini.Background: Obesity-related metabolic disorders are among the leading causes of morbidity and mortality in the developed world. Structural and functional changes in skeletal muscles and the microvasculature are critically involved in the mediation of obesity-related insulin resistance. A shift from expression of slow to fast type myosin heavy chain isoforms in slow twitch muscles has been shown to contribute to reduced insulin sensitivity in obesity, while in fast-twitch weight-bearing muscles no fibre type shifting was observed. Furthermore, in obesity, accumulation of lipid droplets in skeletal muscle fibres can also contribute to insulin resistance. However, it is not yet clear how intramyocellular lipid accumulation and fibre type changes are associated. Moreover, in advanced obesity with insulin resistance, reduced capillary network density in skeletal muscles and impaired capillary recruitment has been demonstrated. On the other hand, in the early stage of obesity with insulin resistance, an increased functional vascular response to insulin has been described. However, it remains unclear whether such functional vascular response is associated with morphological alterations in the capillary network, or if the switch of fibre types toward fast type isoforms also occurs in fast-twitch, non-weight-bearing muscles in the early stages of obesity with insulin resistance.
Methods: The study was carried out using eighteen 54-week-old C57BL/6JOlaHsd mice, divided into two study groups of nine mice each: the high fat diet-induced obese and the standard diet-treated lean groups. Insulin resistance status was assessed by the oral glucose tolerance test and fasting glucose measurements. We determined the capillary network characteristics using 3D analysis of 100 µm thick transverse sections of gluteus maximus muscle, and employed immunofluorescent techniques to mark the capillary endothelium and the basement membrane of capillaries and muscle fibres, which were then captured with a confocal microscope and analysed with the Ellipse software. We used the indirect immunohistochemical method to determine the myosin heavy chain isoform expression in muscle fibres. Antibodies against myosin heavy chain isoforms type 1, 2a, 2x/d and 2b were used to determine the expression of individual myosin heavy chain isoforms in successive 10 µm thick sections of gluteus maximus, gastrocnemius, plantaris and soleus muscles. We performed analysis of intramyocellular lipid content using 10 µm thick sections of gastrocnemius, plantaris and soleus muscles stained with Sudan Black B, and calculated the lipid content index as 100 times the ratio of the cross-sectional area of muscle fibre occupied by lipid droplets to the cross-sectional area of muscle fibre. The deformations of skeletal muscle thick tissue sections in horizontal plane were determined by comparison of gluteus maximus muscle fibre diameters in 10 µm thick native tissue sections to 100 µm thick fixed and immunofluorescently labelled tissue sections, respectively.
Results: Compared to the standard diet-treated lean mice, mice fed on a high fat diet had a significantly increased body mass (p = 0.0001) and basal glycaemia, and decreased glucose tolerance (p < 0.05). The obese mice also showed denser capillary network of the gluteus maximus muscle compared to lean mice. Compared to the lean mice, capillary length per muscle fibre length, and capillary length per muscle fibre surface area were significantly larger around small muscle fibres (< 40 µm) (p < 0.05) in the obese mice, while there were no significant differences around large fibres in both groups. Other capillary characterization indices such as tortuosity, anisotropy and fibre diameter did not significantly differ between the study groups. In the slow-twitch soleus and fast-twitch non-weight-bearing gluteus maximus muscles, we noted a shift towards fast type myosin heavy chain isoform expression in the obese mice (p < 0.05), while in the weight-bearing fast-twitch gastrocnemius and intermediate plantaris muscles there were no significant differences in myosin heavy chain expression between the two study groups. Moreover, in obese mice muscle fibre size and intramyocellular lipid content were significantly increased in type 2a and 2x/d muscle fibres (p<0.05), with greater prominence in the fast- and intermediate-twitch than slow-twitch skeletal muscles. During the preparation of thick transverse sections of skeletal muscle for confocal microscopy, we demonstrated significant dilation of the sections in horizontal direction (p < 0.001) and shrinkage in the axial direction (p < 0.001). In addition, we noted a positive correlation between the magnitude of horizontal dilation and the magnitude of shrinkage in the axial direction (r = 0.493, p < 0.01), the latter being more pronounced in transversely than obliquely cut tissue sections.
Conclusions: We found a selective increase in capillarisation around small muscle fibres of the more oxidative fibre types in our obese insulin-resistant mice, which could be an early compensatory mechanism ameliorating obesity-related insulin resistance. Our findings further suggest that in obesity with insulin resistance, both slow- and fast-twitch muscles exhibit the tendency for a shift toward fast type myosin heavy chain isoforms, and that increased weight bearing may condition the resistance of fast-twitch muscles to fibre type shifting. Our results also reaffirm that in obesity, intramyocellular lipid accumulation is specific for both skeletal muscle and fibre types, with greater prominence in fast-twitch muscles and muscle fibre types 1, 2a and 2x/d. Finally, our study also provide evidence on horizontal dilation and axial shrinkage of thick transverse sections of skeletal muscle. The magnitude of the former was partially dependent on the latter, suggesting that even though axial shrinkage can be corrected by calibration, histological protocols should be optimised to minimize the axial collapse that could cause horizontal dilation
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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