ABSTRACT
OBJECTIVE: To compare health and skill related physical fitness profiles between healthy, male, basketball and football players of Sri Lankan national teams. RESULTS: Thirty basketball players (mean age 24 ± 4.5 years) and 30 football players (mean age 23 ± 4.3 years) were evaluated for health related fitness characteristics (body fat percentage, cardio-respiratory fitness, isometric hand grip strength, lower body and upper body muscular strength, abdominal and upper body muscular endurance, and flexibility) and skill related fitness characteristics (agility, speed, explosive throwing power, jumping power, reaction time, coordination, static balance). Fat percentage, upper body endurance, grip strength, running speed, explosive power, jumping power, balance and coordination were significantly higher in basketball players than in footballers. Football players had better upper body strength, flexibility, reaction time and agility than those of basketball players. The latter two were statistically significant. Basketball players had better mean lower body strength, although not significant. Fitness characteristics were different between basketball and football players. The results have implications in tailoring training activities to improve relevant fitness characteristics.
Subject(s)
Athletic Performance/physiology , Basketball/physiology , Football/physiology , Health Status , Physical Fitness/physiology , Adult , Hand Strength/physiology , Humans , Male , Muscle Strength/physiology , Physical Endurance/physiology , Running/physiology , Sri Lanka , Young AdultABSTRACT
Mice were fed ad libitum with a normal diet (25% protein) or low-protein diets (0-12.5% protein) for a wk and then infected with a nonlethal or lethal strain of Plasmodium yoelii, that is, blood stage infection. The same diet was continued until recovery. Mice fed with a normal diet showed severe parasitemia during nonlethal infection, but survived the infection. They died within 2 wk in the case of lethal infection. However, all mice fed with low-protein diets survived without apparent parasitemia (there were small peaks of parasitemia) in cases of both nonlethal and lethal strains. These surviving mice were found to have acquired potent innate immunity, showing the expansion of NK1.1 -TCRint cells and the production of autoantibodies during malarial infection. Severe combined immunodeficiency (scid) mice, which lack TCRint cells as well as TCRhigh cells, did not survive after malarial infection of lethal strain of P. yoelii, even when low-protein diets were given. These results suggest that low-protein diets enhanced innate immunity and inversely decreased conventional immunity, and that these immunological deviations rendered mice resistant against malaria. The present outcome also reminds us of our experience in the field study of malaria, in which some inhabitants eventually avoided contracting malaria even after apparent malarial infection.
Subject(s)
Diet, Protein-Restricted , Malaria/immunology , Malaria/prevention & control , Plasmodium yoelii/immunology , Animals , Immunophenotyping , Liver/cytology , Lymphocyte Count , Lymphocytes/classification , Lymphocytes/immunology , Mice , Mice, Inbred C57BL , Mice, SCID , Parasitemia/immunology , Parasitemia/prevention & control , Spleen/cytology , Thymus Gland/cytologyABSTRACT
Plasmodium yoelii-infected erythrocytes were injected into mice with or without 6.5 Gy irradiation. This irradiation suppressed erythropoiesis and induced severe immunosuppression. However, these mice showed a rather delayed infection, suggesting that fresh erythrocytes may become malarial targets. In other words, malarial infection did not persist without newly generated erythrocytes in mice. We then examined erythropoiesis in the liver and bone marrow of mice with malaria. Surprisingly, erythropoiesis began in the liver. At this time, the serum level of erythropoietin (EPO) was prominently elevated and the EPO mRNA also became detectable in the kidney. Many clusters of red blood cells appeared de novo in the parenchymal space of the liver. These results revealed that malarial infection had a potential to induce the onset of hepatic erythropoiesis in mice.
Subject(s)
Erythropoiesis/physiology , Liver/physiopathology , Malaria/physiopathology , Plasmodium yoelii , Animals , Disease Models, Animal , Immunohistochemistry , Leukocytes, Mononuclear/physiology , Liver/pathology , Malaria/blood , Malaria/pathology , Mice , Mice, Inbred C57BL , Parasitemia/immunology , Parasitemia/physiopathology , Reference Values , Time FactorsABSTRACT
Athymic nude mice carry neither conventional T cells nor NKT cells of thymic origin. However, NK1.1(-)TCR(int) cells are present in the liver and other immune organs of athymic mice, because these lymphocyte subsets are truly of extrathymic origin. In this study, we examined whether extrathymic T cells had the capability to protect mice from malarial infection. Although B6-nu/nu mice were more sensitive to malaria than control B6 mice, these athymic mice were able to survive malaria when a reduced number of parasitized erythrocytes (5 x 10(3) per mouse) were injected. At the fulminant stage, lymphocytosis occurred in the liver and the major expanding lymphocytes were NK1.1(-)TCR(int) cells (IL-2Rbeta(+)TCRalphabeta(+)). Unconventional CD8(+) NKT cells (V(alpha)14(-)) also appeared. Similar to the case of B6 mice, autoantibodies (IgM type) against denatured DNA appeared during malarial infection. Immune lymphocytes isolated from the liver of athymic mice which had recovered from malaria were capable of protecting irradiated euthymic and athymic mice from malaria when cell transfer experiments were conducted. In conjunction with the previous results in euthymic mice, the present results in athymic mice suggest that the major lymphocyte subsets associated with protection against malaria might be extrathymic T cells.
