In situ localization of muscle insulin-like growth factor-II mRNA in developing bovine fetuses.

Insulin-like growth factor-II (IGF-II) modulates myogenesis in muscle cell cultures, in utero. IGF-II gene expression is developmentally regulated in several tissues including muscle. Determining whether IGF-II is expressed by developing muscle cells or by neighbouring cells in developing muscle tissue is crucial for determining whether IGF-II exerts a paracrine or an autocrine affect on myogenesis.

Induction of myoblast proliferation in L6 myoblast cultures by fetal serum of double-muscled and normal cattle.

Double-muscled (DM) cattle possess more muscle fibers than do normal-muscled (NM) beef or dairy cattle. Serum-borne growth factors have been shown to modulate myogenesis. Media containing serum from 12 DM and 60 NM fetuses grouped by crown-rump lengths (CRL) of < or = 25, 26 to 50, 51 to 75, or > 75 cm were used to test the effect of fetal serum on L6 myoblast proliferation.

Overuse injury and growing bones: the young athlete at risk.

Increasing numbers of children are becoming involved in competitive sport. International trends in pre-adolescent sports participation are mirrored in New Zealand, where promising young athletes are being exposed to high-intensity training from an earlier age. As a consequence, overuse injuries which were traditionally described in more mature athletes are now becoming recognized in pre-adolescents.

Action of cyclosporin A on the tapeworm Hymenolepis diminuta in mice.

Cyclosporin A (CsA), administered in 5 daily subcutaneous doses of 50 mg/kg to MF1 mice immediately following infection with Hymenolepis diminuta enhanced parasite growth relative to controls. Drug administered at 24 h intervals for 10 days, and thereafter every 48 h to MF1 and CBA/Ca mice infected with H. diminuta, increased worm survival and growth, delayed host-mediated expulsion of the parasite and enabled some worms to develop to patency.

Pacemaker longevity modelling.

A generalized mathematical technique is presented for computing the elapsed time necessary for a lithium iodine powered pacemaker to reach any specified battery voltage or degree of battery discharge within its life span. In particular, the method yields a direct mathematical expression for the longevity of pacemakers the circuits of which possess linear load lines. Because the current-voltage relationship, which defines the load line, is affected by programmed output settings, electrode/tissue interface impedance and degree of inhibition, the method enables the direct determination of the effect of these parameters on pacemaker longevity.

Collagen stability, testosterone secretion and meat tenderness in growing bulls and steers.

Interrelationships among concentrations and maturation of intramuscular collagen, serum concentration of hydroxyproline and testosterone and meat tenderness were determined in growing bulls and steers. Sixty-four Charolais X Angus bulls were assigned to sex treatment groups (intact or castrate) and slaughter groups (9, 12, 15 or 18 mo of age). Animals were bled at 30-min intervals via intrajugular catheters between 0600 and 1400 beginning 48 h before slaughter.

Effect of moderate exercise on esophageal function in asymptomatic athletes.

It has been thought that upper intestinal symptoms of heartburn, regurgitation, belching, and chest pain experienced during exercise may represent esophageal dysfunction. The aim of this study is to examine esophageal function during moderate exercise in asymptomatic healthy athletes. Six healthy male athletes were exercised for 2 h on a treadmill set at a workload of 50% of their maximum oxygen uptake.

Gastrointestinal symptoms during exercise in Enduro athletes: prevalence and speculations on the aetiology.

A study of the prevalence of gastrointestinal symptoms during exercise was carried out on athletes who participated in the recent Enduro event in Dunedin. Of 119 competitors, 70 (59%) responded to our questionnaire and demonstrated a prevalence of gastrointestinal symptoms of 81%. Upper gastrointestinal symptoms were noticed in 58% with lower gastrointestinal symptoms, tending to be more severe and significant to the athlete, noticed in 61%.