Does small-sided-games’ court area influence metabolic,perceptual, and physical performance parameters of young elite basketball players?

The purpose of this study was to investigate the effect of court size on physiological responses and physical performance of young elite basketball players. Twelve male basketball players (18.6 ± 0.5 years; 88.8 ± 14.5 kg; 192.6 ± 6.5 cm) from an under-19 team performed two small-sided games (matches) with different court areas (28x15 m and 28x9 m; 28x15 and 28x9 protocols). The number of players (3x3) was kept the same in each protocol. The players performed a repeated-sprint ability (RSA) test before and after each match. Blood lactate concentration was collected before (pre) and after (post) the matches, and the session rating of perceived exertion (session-RPE) was determined 30 minutes after the match. Best and mean time in the RSA test were not different between the 28x15 and the 28x9 match protocols (p > 0.05). A significant difference was observed for lactate concentration from pre- to post-match (p < 0.05) in both protocols (28x15 and 28x9); however, there was no significant interaction between protocols. A similar session-RPE mean score (28x15: 7.2 ± 1.4 and 28x9: 6.6 ± 1.4) was detected for both protocols (p > 0.05, ES=0.41). In summary, the results of the current study suggest that the different court areas induced similar responses. Although there was no significant difference in effort perception, players tended to perceive a greater effort in the larger court size.     

Compound 48/80 induces endothelium-dependent and histamine release-independent relaxation in rabbit aorta.

Compound 48/80 (C48/80) is a synthetic condensation product of N-methyl-p-methoxyphenethylamine with formaldehyde and is an experimental drug used since the 1950s to induce anaphylactic shock through histamine release. This study was carried out to further elucidate the mechanism by which this drug induces nitric oxide (NO) release. Our specific goals were: (a) to verify if C48/80's relaxation occurs through the stimulation of histamine receptors; (b) to evaluate the endothelium-dependent relaxation induced by C48/80; (c) to identify NO as the endothelium-relaxing factor released by C48/80; (d) to identify the NO synthase (NOS) responsible for NO release; and (e) to verify if the relaxation induced by C48/80 is calcium and cyclic guanidine monophosphate (cGMP) dependent. Rabbit aorta segments, with and without endothelium, were suspended in organ chambers (25ml) filled with Krebs solution maintained at 37 degrees C, bubbled with 95% O(2)/5% CO(2) (pH 7.4). Phenylephrine was used to contract the segments. Other protocol drugs included H(1)- and H(2)-receptor antagonists, cyclooxygenase, NOS, guanylyl cyclase and phospholipase C (PLC) inhibitors. Endothelium-dependent relaxation induced by C48/80 was also studied in calcium-free Krebs solution associated with a calcium chelator. In summary, our investigation demonstrated that the C48/80 vasodilating action: (a) does not depend on H(1) and H(2) histamine receptors; (b) is NO endothelium-dependent; (c) is dependent on the endothelial constitutive NOS (NOS-3) isoform activation; (d) is cGMP-dependent; and that NOS-3 activation by C48/80: (a) is independent of PLC up to 25mug/ml and (b) is partially dependent of this lipase in higher doses.     

N-Linked glycosylation of a baculovirus-expressed recombinant glycoprotein in insect larvae and tissue culture cells

The potential of insect cell cultures and larvae infected with recombinant baculoviruses to produce authentic recombinant glycoproteins cloned from mammalian sources was investigated. A comparison was made of the N-linked glycans attached to secreted alkaline phosphatase (SEAP) produced in four species of insect larvae and their derived cell lines plus one additional insect cell line and larvae of one additional species. These data survey N-linked oligosaccharides produced in four families and six genera of the order Lepidoptera. Recombinant SEAP expressed by recombinant isolates of Autographa californica and Bombyx mori nucleopolyhedroviruses was purified from cell culture medium, larval hemolymph or larval homogenates by phosphate affinity chromatography. The N-linked oligosaccharides were released with PNGase-F, labeled with 8- aminonaphthalene-1-3-6-trisulfonic acid, fractionated by polyacrylamide gel electrophoresis, and analyzed by fluorescence imaging. The oligosaccharide structures were confirmed with exoglycosidase digestions. Recombinant SEAP produced in cell lines of Lymantria dispar (IPLB-LdEIta), Heliothis virescens (IPLB-HvT1), and Bombyx mori (BmN) and larvae of Spodoptera frugiperda, Trichoplusia ni , H.virescens , B.mori , and Danaus plexippus contained oligosaccharides that were structurally identical to the 10 oligosaccharides attached to SEAP produced in T.ni cell lines. The oligosaccharide structures were all mannose-terminated. Structures containing two or three mannose residues, with and without core fucosylation, constituted more than 75% of the oligosaccharides from the cell culture and larval samples.      

In situ hybridization at the electron microscope level: hybrid detection by autoradiography and colloidal gold

In situ hybridization has become a standard method for localizing DNA or RNA sequences in cytological preparations. We developed two methods to extend this technique to the transmission electron microscope level using mouse satellite DNA hybridization to whole mount metaphase chromosomes as the test system. The first method devised is a direct extension of standard light microscope level using mouse satellite DNA hybridization to whole mount metaphase chromosomes as the test system. The first method devised is a direct extension of standard light microscope in situ hybridization. Radioactively labeled complementary RNA (cRNA) is hybridized to metaphase chromosomes deposited on electron microscope grids and fixed in 70 percent ethanol vapor; hybridixation site are detected by autoradiography. Specific and intense labeling of chromosomal centromeric regions is observed even after relatively short exposure times. Inerphase nuclei present in some of the metaphase chromosome preparations also show defined paatterms of satellite DNA labeling which suggests that satellite-containing regions are associate with each other during interphase. The sensitivity of this method is estimated to at least as good as that at the light microscope level while the resolution is improved at least threefold. The second method, which circumvents the use of autoradiogrphic detection, uses biotin-labeled polynucleotide probes. After hybridization of these probes, either DNA or RNA, to fixed chromosomes on grids, hybrids are detected via reaction is improved at least threefold. The second method, which circumvents the use of autoradiographic detection, uses biotin-labeled polynucleotide probes. After hybridization of these probes, either DNA or RNA, to fixed chromosomes on grids, hybrids are detected via reaction with an antibody against biotin and secondary antibody adsorbed to the surface of over centromeric heterochromatin and along the associated peripheral fibers. Labeling is on average ten times that of background binding. This method is rapid and possesses the potential to allow precise ultrastructual localization of DNA sequences in chromosomes and chromatin.     

Effect of the effluent released from the canine internal mammary artery after intraluminal and extraluminal perfusion of acetylcholine and adenosine diphosphate

Segments of the canine internal mammary artery (35 mm in length) were suspended in vitro in an organ chamber containing physiological salt solution (95% O₂/5% CO₂, pH = 7.4, 37°C). Segments were individually cannulated and perfused at 5 ml/minute using a roller pump. Vasorelaxant activity of the effluent from the perfused internal mammary arteries was bioassayed by measuring the decrease in tension induced by the effluent of the coronary artery endothelium-free ring which had been contracted with prostaglandin F_2α (2 × 10^-6 M). Intraluminal perfusion of adenosine diphosphate (10^-5 M) induced significant increase in relaxant activity in the effluent from the perfused blood vessel. However, when adenosine diphosphate (10^-5 M) was added extraluminally to the internal mammary artery, no change in relaxant activity in the effluent was noted. In contrast, acetylcholine produced significant increase in the relaxant activity on the effluent of the perfused internal mammary artery with both intraluminal and extraluminal perfusion. The intraluminal and extraluminal release of endothelium-derived relaxing factor (EDRF) by acetylcholine (10^-5 M) can be inhibited by site-specific administration of atropine (10^-5 M). These experiments indicate that certain agonists can induce the release of EDRF only by binding to intravascular receptors while other agonists can induce endothelium-dependent vasodilatation by acting on neural side receptors.