Effects of a single dose of N-Acetyl-5-methoxytryptamine (Melatonin) and resistance exercise on the growth hormone/IGF-1 axis in young males and females

Melatonin and resistance exercise alone have been shown to increase the levels of growth hormone (GH). The purpose of this study was to determine the effects of ingestion of a single dose of melatonin and heavy resistance exercise on serum GH, somatostatin (SST), and other hormones of the GH/insulin-like growth factor 1 (IGF-1) axis. Physically active males (n = 30) and females (n = 30) were randomly assigned to ingest either a melatonin supplement at 0.5 mg or 5.0 mg, or 1.0 mg of dextrose placebo. After a baseline blood sample, participants ingested the supplement and underwent blood sampling every 15 min for 60 min, at which point they underwent a single bout of resistance exercise with the leg press for 7 sets of 7 reps at 85% 1-RM. After exercise, participants provided additional blood samples every 15 min for a total of 120 min. Serum free GH, SST, IGF-1, IGFBP-1, and IGFBP-3 were determined with ELISA. Data were evaluated as the peak pre- and post-exercise values subtracted from baseline and the delta values analyzed with separate three-way ANOVA (p < 0.05). In males, when compared to placebo, 5.0 mg melatonin caused GH to increase (p = 0.017) and SST to decrease prior to exercise (p = 0.031), whereas both 0.5 and 5.0 mg melatonin were greater than placebo after exercise (p = 0.045) and less than placebo for SST. No significant differences occurred for IGF-1; however, males were shown to have higher levels of IGFBP-1 independent of supplementation (p = 0.004). The 5.0 mg melatonin dose resulted in higher IGFBP-3 in males (p = 0.017). In conclusion, for males 5.0 mg melatonin appears to increase serum GH while concomitantly lowering SST levels; however, when combined with resistance exercise both melatonin doses positively impacts GH levels in a manner not entirely dependent on SST.     

Identifying discriminating variables between teachers who fully integrate computers and teachers with limited integration

Given the prevalence of computers in education today, it is critical to understand teachers’ perspectives regarding computer integration in their classrooms. The current study surveyed a random sample of a heterogeneous group of 185 elementary and 204 secondary teachers in order to provide a comprehensive summary of teacher characteristics and variables that best discriminate between teachers who integrate computers and those who do not. Discriminant Function Analysis indicated seven variables for elementary teachers and six for secondary teachers (accounting for 74% and 68% of the variance, respectively) that discriminated between high and low integrators. Variables included positive teaching experiences with computers; teacher’s comfort with computers; beliefs supporting the use of computers as an instructional tool; training; motivation; support; and teaching efficacy. Implications for support of computer integration in the classroom are discussed.     

Criterion validity and the utility of reactive and proactive aggression: comparisons to attention deficit hyperactivity disorder, oppositional defiant disorder, conduct disorder, and other measures of functioning

Human immunodeficiency virus (HIV)-associated nephropathy (HIVAN) is a clinicopathologic entity that includes proteinuria, azotemia, focal segmental glomerulosclerosis or mesangial hyperplasia, and tubulointerstitial disease. The incidence of HIVAN is increased in black patients and variable depending on the age and geographic area. The objective of this study was to describe relevant clinical and pathological findings in 30 children with HIVAN followed at the Children's National Medical Center in Washington, D.C. Our experience of the last 12 years showed a spectrum of HIVAN that seems to be coincident with the degree of acquired immunodeficiency syndrome (AIDS) symptomatology. By renal sonograms and frequent urinalysis, we identified children undergoing the early stages of HIVAN with enlarged echogenic kidneys, proteinuria, and "urine microcysts". HIVAN did not necessarily progress rapidly to end-stage renal disease. Nephrotic syndrome or chronic renal insufficiency were late manifestations of HIVAN. Children with HIVAN were likely to develop transient electrolyte disorders, heavy proteinuria, and acute renal failure due to systemic infectious episodes or nephrotoxic drugs. HIVAN was associated with other HIV-induced illnesses and high mortality rates. Early detection and careful clinical follow-up of children with HIVAN may reduce the incidence of renal-cardiovascular complications and improve their quality of life.     

The use of angiostatic steroids to inhibit cartilage destruction in an in vivo model of granuloma-mediated cartilage degradation

Angiogenesis is an important component of the development of chronic inflammatory diseases such as rheumatoid arthritis. It is known that clinically used anti-rheumatic drugs exert, in part, effects on the angiogenic response. Little work, however, has investigated the potential of experimental angiostatic therapies in chronic inflammatory disease models. The effect of one such angiostatic treatment, cortisone combined with heparin, was tested in an in vivo model of granuloma-mediated cartilage degradation. Angiostatic treatment significantly retarded the growth of granulomatous tissue, mononuclear cell influx into the granuloma, and the degradation of juxtaposed cartilage. This correlated with a decrease in the vascularity of the granulomatous tissue. Modulation of this component of pathogenesis of "angiogenesis-dependent disease" may be useful as a new therapeutic approach.     

ISSN exercise & sport nutrition review: research & recommendations

Sports nutrition is a constantly evolving field with hundreds of research papers published annually. For this reason, keeping up to date with the literature is often difficult. This paper is a five year update of the sports nutrition review article published as the lead paper to launch the JISSN in 2004 and presents a well-referenced overview of the current state of the science related to how to optimize training and athletic performance through nutrition. More specifically, this paper provides an overview of: 1.) The definitional category of ergogenic aids and dietary supplements; 2.) How dietary supplements are legally regulated; 3.) How to evaluate the scientific merit of nutritional supplements; 4.) General nutritional strategies to optimize performance and enhance recovery; and, 5.) An overview of our current understanding of the ergogenic value of nutrition and dietary supplementation in regards to weight gain, weight loss, and performance enhancement. Our hope is that ISSN members and individuals interested in sports nutrition find this review useful in their daily practice and consultation with their clients.     

Differential effects of inhibitors of cyclooxygenase (cyclooxygenase 1 and cyclooxygenase 2) in acute inflammation

The anti-inflammatory activity of drugs more selective for cyclooxgenase isoform inhibition (cyclooxygenase 1, cyclooxygenase 2), were compared in rat carrageenin-induced pleurisy. Suppression of inflammation by cyclooxygenase 2-selective inhibitors, NS-398 (N-[-2-cyclohexyloxy]-4-nitrophenyl methanesulphonamide) and nimesulide (4-nitro-2-phenoxy-methanesulfonanilide), and by piroxicam and aspirin, more selective for cyclooxygenase 1, was measured. Piroxicam and aspirin significantly inhibited inflammatory cell influx, exudate and prostaglandin E2 formation, 6 h after carrageenin injection. Cyclooxygenase 2 inhibitors had little effect on these parameters with NS-398 alone reducing prostaglandin E2 levels, but increasing levels of leukotriene B4. In contrast, at 3 h after carrageenin injection, cyclooxygenase 2 inhibitors significantly inhibited all inflammatory parameters however suppression with piroxicam and aspirin was greater, and more pronounced than at 6 h. NS-398 and nimesulide dosing did not reduce thromboxane B2 production from platelets isolated from rats with carrageenin-induced pleurisy, demonstrating that at the doses used, cyclooxygenase 2 inhibitors did not inhibit cyclooxygenase 1, as platelets contain only this isoform. Therefore, in the rat carrageenin-induced pleurisy, drugs more selective for the inhibition of cyclooxygenase 1 attenuate inflammation over a wider time frame than cyclooxygenase 2-selective drugs, suggesting a significant role for cyclooxygenase 1 in this model. Inhibition of cyclooxygenase 2 by NS-398 however, resulted in an increase in the potent chemoattractant leukotriene B4.