Kraft-hastighets-profiler hos kastere på nasjonalt nivå: En tverrsnittsstudie

Introduksjon: En skjelettmuskel har to egenskaper: 1) evnen til å produsere kraft, og 2) evnen til å forkorte seg (målt som forkortningshastighet). Produktet av kraft og hastighet, effekt, er avgjørende i idretter hvor et arbeid (kraft x vei) skal gjøres raskest mulig. Kraft-hastighets(KH)-forholdet kan etableres ved en KH-profil-test. Helningen («slopen») til KH-profilen sier noe om hvilken av egenskapene, kraft eller hastighet, som begrenser effekten mest og angivelig bør prioriteres i treningen. Det er imidlertid usikkert hvor idrettsspesifikke KH-tester må være. Derfor er kastere i friidrett en interessant utøvergruppe, fordi de gjennomfører øvelser som både egner seg som generelle og spesifikke KH-tester. Formålet med denne studien er todelt: 1) undersøke sammenhengen mellom slopen fra generelle KH-profiler (benpress og benkpress) og spesifikke kastprofiler i diskos, slegge og kule, og 2) undersøke sammenhengen mellom kraft, hastighet og effekt i generelle KH-tester og prestasjon i diskos, slegge og kule. Metode: Problemstillingen ble undersøkt med to tverrsnittsundersøkelser. Nitten (18 ± 2 år, 87 ± 13 kg, 179 ± 9 cm) og 23 (18 ± 2 år, 87 ± 13 kg, 180 ± 10 cm) utøvere fra rekruttlandslaget i kast ble rekruttert til studien. Tolv utøvere var med i begge utvalgene. Forsøkspersonene gjennomførte tre generelle KH-tester (benpress, benkpress og svikthopp) ved begge anledninger samt en spesifikk kast-test i idrettsgrenen (1. datainnsamling) og en generell kast-spesifikk test, Liakov (2. datainnsamling) Resultat: Det var ingen signifikant sammenheng mellom slopen fra KH-profilene i benpress og benkpress og slopen til kastprofilene. Diskosprestasjon korrelerte best med maksimal effekt i benkpress (R=0,98, p=0,00). Sleggeprestasjon korrelerte best med maksimal effekt i benpress (R=0,93, p=0,00). Kuleprestasjon korrelerte best med maksimal kraft i benpress (R=1,00, p=0,00). Konklusjon: Med forbehold om lav statistisk styrke og tverrsnittsdesign, indikerer denne studien at KH-profiler for kastere i friidrett bør være idrettsspesifikke for å kunne si noe om hva man skal vektlegge i den spesifikke treningen. Kastere burde likevel vektlegge generell styrketrening ettersom maksimal kraft og effekt i benkpress og benpress viste god sammenheng med kastprestasjon

Effects of dietary soybean meal, inulin and oxytetracycline on gastrointestinal histological characteristics, distal intestine cell proliferation and intestinal microbiota in Atlantic salmon (Salmo salar L.)

Soyabean meal (SBM)-induced enteritis in the distal intestine of the teleost Atlantic salmon (Salmo salar L.) and other salmonids may be considered a model for diet-related mucosal disorders in other animals and man. The role of the intestinal microbiota in its pathogenesis was explored. Compared to diets containing fishmeal (FM) as the sole protein source, responses to extracted SBM or the prebiotic inulin, with or without oxytetracycline (OTC) inclusion, were studied following a 3-week feeding trial. Intestinal microbiota, organosomatic indices and histology, as well as immunohistochemical detection of proliferating cell nuclear antigen (PCNA), heat shock protein 70 (HSP70) and caspase-3-positive cells in the distal intestine, were studied. Distal intestine somatic indices (DISI) were higher in inulin and lower in SBM compared to FM-fed fish. The low DISI caused by SBM corresponded with histological changes, neither of which was affected by OTC, despite a significant decrease in adherent bacteria count. Image analysis of PCNA-stained sections showed a significant increase in the proliferative compartment length in SBM-fed fish, accompanied by apparent increases in reactivity to HSP70 and caspase-3 along the mucosal folds, indicating induction of cellular repair and apoptosis, respectively. Fish fed the SBM diet had higher total number as well as a more diverse population composition of adherent bacteria in the distal intestine. Thus SBM-induced enteritis is accompanied by induction of distal intestinal epithelial cell protective responses and changes in microbiota. Putative involvement of bacteria in the inflammatory response merits further investigation

Integration of T helper and BCR signals governs enhanced plasma cell differentiation of memory B cells by regulation of CD45 phosphatase activity

Humoral immunity relies on the efficient differentiation of memory B cells (MBCs) into antibody-secreting cells (ASCs). T helper (Th) signals upregulate B cell receptor (BCR) signaling by potentiating Src family kinases through increasing CD45 phosphatase activity (CD45 PA). In this study, we show that high CD45 PA in MBCs enhances BCR signaling and is essential for their effective ASC differentiation. Mechanistically, Th signals upregulate CD45 PA through intensifying the surface binding of a CD45 ligand, Galectin-1. CD45 PA works as a sensor of T cell help and defines high-affinity germinal center (GC) plasma cell (PC) precursors characterized by IRF4 expression in vivo. Increasing T cell help in vitro results in an incremental CD45 PA increase and enhances ASC differentiation by facilitating effective induction of the transcription factors IRF4 and BLIMP1. This study connects Th signals with BCR signaling through Galectin-1-dependent regulation of CD45 PA and provides a mechanism for efficient ASC differentiation of MBCs

The genome sequence of Atlantic cod reveals a unique immune system

Atlantic cod (Gadus morhua) is a large, cold-adapted teleost that sustains long-standing commercial fisheries and incipient aquaculture. Here we present the genome sequence of Atlantic cod, showing evidence for complex thermal adaptations in its haemoglobin gene cluster and an unusual immune architecture compared to other sequenced vertebrates. The genome assembly was obtained exclusively by 454 sequencing of shotgun and paired-end libraries, and automated annotation identified 22,154 genes. The major histocompatibility complex (MHC)?II is a conserved feature of the adaptive immune system of jawed vertebrates, but we show that Atlantic cod has lost the genes for MHC?II, CD4 and invariant chain (Ii) that are essential for the function of this pathway. Nevertheless, Atlantic cod is not exceptionally susceptible to disease under natural conditions. We find a highly expanded number of MHC?I genes and a unique composition of its Toll-like receptor (TLR) families. This indicates how the Atlantic cod immune system has evolved compensatory mechanisms in both adaptive and innate immunity in the absence of MHC?II. These observations affect fundamental assumptions about the evolution of the adaptive immune system and its components in vertebrates