The role of the biceps brachii in shoulder elevation.

The biceps brachii is a bi-articular muscle affecting motion at the shoulder and elbow. While its' action at the elbow is well documented, its role in shoulder elevation is less clear. Therefore, the purpose of this project was to investigate the influence of shoulder and elbow joint angles on the shoulder elevation function of the biceps brachii. Twelve males and 18 females were tested on a Biodex dynamometer with the biceps brachii muscle selectively stimulated at a standardized level of voltage. The results indicated that both shoulder and elbow joint angles influence the shoulder joint elevation moment produced by the biceps brachii. Further analysis revealed that the elevation moment was greatest with the shoulder joint at 0 degrees and the elbow flexed 30 degrees or less. The greatest reduction in the elevation moment occurred between shoulder angles of 0 degrees and 30 degrees . The shoulder elevation moment was near zero when shoulder elevation reached or exceeded 60 degrees regardless of elbow angle. These results clarify the role of the biceps in shoulder elevation, as a dynamic stabilizer, and suggest that it is a decelerator of the arm during the throwing motion.     

Diving beetles (Dytiscidae) as predators of mosquito larvae (Culicidae) in field experiments and in laboratory tests of prey preference

Field experiments were performed in artificial ponds to evaluate how the density of predatory diving beetles (Dytiscidae) would affect the population levels of mosquito larvae (Culicidae). Mosquitoes colonizing the ponds were predominantly species of the genus Culex. In 2000, most of the dytiscids colonizing the ponds were small (Hydroporus spp.), and these predators had no impact on the size of larval mosquito populations, not even in ponds with added dytiscids. In 2001, larger beetles (Ilybius, Rhantus, and Agabus spp.) were more common, and there were significantly fewer mosquito larvae in ponds with the highest numbers of dytiscids. There was a negative correlation between numbers of diving beetles in the ponds and the mean body length of mosquito larvae. In neither year could dytiscid densities be maintained above a certain level owing to emigration. In laboratory tests, there were marked differences between three common dytiscid species in regard to preferences for Daphnia and Culex species as prey: Colymbetes paykulli Erichson chose mosquito larvae more often, whereas both Ilybius ater (De Geer) and I. fuliginosus (Fabricius) preferred Daphnia spp. All of the tested dytiscids consumed large numbers of prey. Since some dytiscid species can efficiently decrease populations of mosquito larvae, they are probably important in the natural control of these dipterans.     

A c-ras-Ki oncogene is activated, amplified and overexpressed in a human osteosarcoma cell line

We present a characterization of an activated oncogene which we found to be present in DNA of the OHA osteosarcoma cell line. We identify this tumor oncogene which transforms Swiss mouse 3T3-cells, with c-ras-Ki 2, one of two known members of the Kirsten ras family of human proto-oncogenes. Its structural outlines are given and we show that: 1) a single point mutation causing a substitution of valine for glycine in codon 12 was found by DNA sequencing; 2) the c-ras-Ki gene is amplified and overexpressed in the original OHA tumor cells and its transformants and 3) the gene product is an abnormal form of the p21 protein.     

Inhibition of entry of the lipid-containing bacteriophage PR4 by fatty acid derivatives.

Amphiphilic fatty acid derivatives having a 14- to 20-carbon cis-unsaturated alkyl chain were found to be potent inhibitors of the entry process of the lipid-containing bacteriophage PR4.     

Characterization of β-lapachone and methylated β-cyclodextrin solid-state systems

The purpose of this research was to explore the utility of β cyclodextrin (βCD) and β cyclodextrin derivatives (hydroxypropyl-β-cyclodextrin [HPβCD], sulfobutylether-β-CD [SB\CD], and a randomly methylated-β-CD [RMβCD]) to form inclusion complexes with the antitumoral drug, β-lapachone (βLAP), in order to overcome the problem of its poor water solubility. RMβCD presented the highest efficiency for βLAP solubilization and was selected to develop solid-state binary systems. Differential scanning calorimetry (DSC), X-ray powder diffractometry (XRPD), Fourier transform infrared (FTIR) and optical and scanning electron microscopy results suggest the formation of inclusion complexes by both freeze-drying and kneading techniques with a dramatic improvement in drug dissolution efficiency at 20-minute dissolution efficiency (DE_20-minute 67.15% and 88.22%, respectively) against the drug (DE_20-minute 27.11%) or the βCD/drug physical mixture (DE_20-minute 27.22%). However, the kneading method gives a highly crystalline material that together with the adequate drug dissolution profile make it the best procedure in obtaining inclusion complexes of RMβCD/βLAP convenient for different applications of βLAP. Published: July 27, 2007     

Early phase strength development: a four-week training comparison of different programs

The purpose of this study was to explore the effects of various exercise sequences in the early weeks of a strength training program. Forty-two untrained men were randomly assigned to one of 4 training regimens, which were differentiated by the order in which the exercises were performed, and trained 3 days per week for 4 weeks. Three regimens were multiple-set protocols (alternating, blocked, and semiblocked), and the fourth was a single-set protocol. The exercises were arm curls, lateral raises, and triceps extensions. Results showed that the blocked group improved significantly more on the arm curl exercise than the single-set group. No other group comparisons were significant. This finding indicates that a blocked multiple-set regimen is superior to a single-set regimen for certain upper-body exercises in the early stages of strength training.