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Mechanical testing of extra-articular distal radius fractures stabilized with percutaneous pins was performed. Twelve fresh-frozen unembalmed radii stripped of all soft tissues were used. An osteotomy with dorsal comminution was made 2.5 cm proximal to the radial styloid. Three pin sizes and four pin configurations were used to fix the fracture, and the constructs were mechanically tested. Results show that at least a .062-inch pin was required for any significant changes in rigidity of the four pin configurations tested to be discerned. Crosspinning with two radial styloid pins and placement of a pin from the ulnar corner of the radius as the most rigid construct in both torsion and cantilever bending.

Transverse tubule (TT) membrane vesicles contain a very active Mg-ATPase (EC 3.6.1.3). Concanavalin A (ConA) and other lectins were found to activate the TT Mg-ATPase from chicken skeletal muscle up to 25-fold yielding specific activities greater than 800 mumol/h/mg. The sarcoplasmic reticulum Ca-ATPase and the sarcolemma Na,K-ATPase were unaffected by ConA. 125I-Labeled lectin binding to the TT membrane Mr 102,000 glycoprotein supports the contention that this protein is identical with or is intimately associated with the TT Mg-ATPase. The ATPase exhibited non-Michaelis-Menton kinetics with both apparent negative cooperativity (n = 0.723; S0.5, Mg-ATP = 14 microM) and substrate inhibition (Ki, Mg-ATP = 10.2 mM), both of which were eliminated in the presence of ConA. Under the same conditions, ConA also abolished the unusual temperature dependence and potent Triton X-100 inhibition. The similarities in ConA suppression of both Triton and substrate inhibition suggest that these ligands may be interacting through a non-catalytic site and that Triton is serving as a nucleotide-mimetic agent. The unique kinetic responses are consistent with a homotropic substrate modifier mechanism wherein the enzyme can be viewed as possessing a single catalytic and a single regulatory site on a single polypeptide chain. It is proposed that ConA interferes either with ligand interaction at a putative regulatory site or blocks communication between a regulatory site and the catalytic site. The possible nature of the regulatory site and its modulation by a ConA-like, endogenous, skeletal muscle lectin and their combined role in excitation-contraction coupling is discussed.

Cross‐shore transport of larvae, pollutants, and sediment between the surf zone and the inner shelf is important for coastal water quality and ecosystems. Rip currents are known to be a dominant pathway for exchange, but the effects of horizontal temperature and salinity gradients are not well understood. Airborne visible and infrared imaging performed on the California coast shows warm and cool plumes driven by rip currents in the surf zone and extending onto the shelf, with temperature differences of approximately 1°C. The airborne imagery and modeled temperatures and tracers indicate that warm plumes exhibit more lateral spreading and transport material in a buoyant near‐surface layer, whereas cool plumes move offshore in a subsurface layer. The average cross‐shore extent of warm plumes at the surface is approximately one surfzone width larger than for cool plumes. Future work may explore the sensitivity of nearshore plumes to density patterns, wave forcing, and bathymetry. Waves and currents in the coastal ocean move plankton, pollutants, nutrients, and sediment between the beach and deeper waters, impacting ecosystems and water quality. Rip currents, strong narrow seaward currents caused by breaking waves, provide a conduit for larvae to move offshore and also carry pollutants away from the beach. One common type of rip current formed in channels interrupting sandbars can sometimes be observed as a plume of brown sediment‐laden water moving offshore. Previous studies of this rip‐current type have assumed that the movement of material by these currents is not affected by differences in the water density (temperature and salinity) between shallower and deeper water. However, thermal (infrared) images taken from an aircraft on the coast of California show that the wave‐breaking region near the beach is often significantly cooler or warmer than the ocean immediately offshore. Rip currents in these images and in numerical simulations appear either as warm plumes, which carry material further offshore and are concentrated at the water surface, or cool plumes, which move material offshore under the surface. The results show that differences in water temperature from the beach to deeper water impact how rip currents move material in the coastal ocean. Airborne infrared imagery on the CA coast shows cool and warm plumes driven by rip currents that connect the surf zone to the inner shelfThe surface cross‐shore extent of warm plumes is about one surfzone width larger than that of cool plumes in observations and simulationsModeled cool nearshore plumes entering a stratified shelf subduct, whereas warm plumes extend offshore in a near‐surface layer Airborne infrared imagery on the CA coast shows cool and warm plumes driven by rip currents that connect the surf zone to the inner shelf The surface cross‐shore extent of warm plumes is about one surfzone width larger than that of cool plumes in observations and simulations Modeled cool nearshore plumes entering a stratified shelf subduct, whereas warm plumes extend offshore in a near‐surface layer

Deterioration of renal function, which can lead to postoperative renal failure, is a complication of surgery involving the suprarenal aorta and surgery involving the renal arteries. Fifty-four patients who were at risk for developing this complication were enrolled in a double-blind, randomized, placebo-controlled trial of insulin-like growth factor (IGF-I) as a therapeutic agent to prevent the decline in renal function. The primary end point was the incidence of renal dysfunction, defined as a reduction of the glomerular filtration rate (creatinine clearance) at each of three measurements over 72 h. IGF-I (100 microg/kg subcutaneously every 12 h for 6 doses) or placebo was administered on admission to the intensive care unit immediately postoperatively. IGF-I- and placebo-treated groups were well matched for sex, age, type of surgery, renal ischemic time during surgery (ischemic index), baseline creatinine clearance, and baseline serum creatinine. No patient in the study developed acute renal failure postoperatively. IGF-I was well tolerated. A smaller proportion of patients in the IGF-I group had a postoperative decline in renal function (22%) than in the placebo-treated group (33%). There were no significant differences in levels of serum creatinine at time of discharge, length of hospital stay, length of intensive care unit stay, length of intubation, or incidence of dialysis or death. Our findings establish the feasibility and potential utility for the use of IGF-I to reduce the incidence of postoperative renal dysfunction in high-risk patients.

The naturally occurring mortality of eggs and larvae of second-generation southwestern corn borer, Diatraea grandiosella (Dyar), in Kansas irrigated field corn, Zea mays L., was investigated. During 1983, corn plants in the study plots averaged 35.4 southwestern corn borer eggs per plant. Egg mortality was 33.2%; egg through third larval stage mortality was 86.2%; and 96.8% mortality occurred from egg through large larval stages. During 1984, plants in the study plots averaged 6.1 eggs per plant. Egg stage mortality was 32.6%; egg through third larval stage mortality was 87.2%; and 87.2% mortality occurred from egg through large larval stages. Trichogramma pretiosum (Riley) was the most significant factor contributing to egg mortality, accounting for 21.9% of total mortality in 1983 and 28.2% of total mortality in 1984.