PET/CT FOLLOWING INTENSITY-MODULATED RADIATION THERAPY FOR PRIMARY LUNG TUMOR IN A DOG

A primary lung tumor in a dog treated with intensity-modulated radiation therapy was imaged approximately 6 weeks and 1-year posttreatment with combined positron emission tomography (PET) and computed tomography, utilizing the radiotracers 18F-fluorodeoxyglucose and 18F-fluorothymidine. These two tracers allowed discrimination of tumor from inflammation, and demonstrated spread of tumor along airways over time after treatment. Fusion of functional imaging with anatomic imaging is a useful tool, particularly in the field of oncology, with the potential for PET markers that delineate tumor from normal or reactive tissue, and potential or actual response to therapy.     

Pharmacokinetics of pentobarbital and thiamylal as combined anesthetics in sheep

This study was performed to investigate the possible mechanisms underlying prolongation of anesthesia times in sheep caused by the sequential administration of thiamylal and pentobarbital. Sodium thiamylal was injected as an intravenous bolus dose (13.2 mg/kg) followed in 7 min by sodium pentobarbital (14.3 mg/kg) by the same route to seven sheep. Separate studies were conducted for each of the two drugs administered separately to the same animals at the same doses. Mean anesthesia times (to the return of the palpebral reflex) were 7.89 min (thiamylal), 5.39 min (pentobarbital) and 34.1 min (the sequential combination). The kinetic parameters Vd(area), Vd(ss), t 1/2 beta, and ClB for either drug were not affected by the other when given in combination. The t 1/2 alpha was shorter, and the Vc was smaller, for pentobarbital when administered with thiamylal, while there were no changes in thiamylal disposition for the combination regimen. Computer-generated curves, associated with the two-compartment open model showing the fraction of dose in each compartment as a function of time, illustrated that pentobarbital rapidly achieved higher concentrations in the peripheral compartment after prior thiamylal administration. Protein-binding studies showed that this could not be attributed to displacement of pentobarbital from plasma albumin by thiamylal. Calculation of total and free drug concentrations at the time of awakening showed that, when the drugs were combined, the concentration of each drug was less than half of that observed at awakening when they were studied separately. It can be concluded that the prolonged sleeping times associated with the sequential combination of the two agents were not due to an alteration in kinetic parameters of either drug caused by the other, but rather to an additive effect of the subanesthetic concentrations of the two drugs when combined. The fact that sleeping times were supra-additive is attributed to a shift of awakening time from the distribution (alpha) phase, when given independently, to the elimination (beta) phase when administered in combination.     

The status of the recently introduced fish Leucaspius delineatus (Cyprinidae) in Great Britain

Abstract The fish Leucaspius delineatus (Heckel) (Cyprinidae) has been introduced to southern England as a result of importation as an ornamental fish. It is now established at several waters (lakes, canals, and lowland rivers) in Hampshire and Somerset. It appears to be well adapted to spread beyond these centres as a result of its small size at sexual maturity and reproductive biology. A preliminary assessment of its diet and fecundity, and notes on its breeding habits are given.     

Eulerian views of layered water currents, vertical distribution of some larval fishes, and inferred advective transport over the continental shelf off North Carolina, USA, in winter

Currents that effect the shoreward transport of the larvae of estuarine-dependent fishes spawned in winter in Onslow Bay, North Carolina, USA, were driven by winds and pressure gradients, and influenced by the Gulf Stream. Aside from storms, winds over the continental shelf in Onslow Bay blew predominantly alongshore with velocities approaching 14 m s^-1 during February and March 1986, and January and February 1989. Water masses and currents observed at two current-meter moorings, one at mid-shelf and the other on the outer shelf, reflected the onshore (or offshore) advection of interior water in compensation for the offshore (or onshore) advection of wind-driven surface water. Winds and currents reversed direction approximately every 4 to 6 days. The larvae of Atlantic menhaden, Brevoortia tyrannus , spot, Leiostomus xan- thurus, and Atlantic croaker, Micropogonias undulatus , were most abundant in 17–19^oC and 20–21^oC water of the outer shelf and Gulf Stream fronts. There was little indication of diel vertical migration; larval Atlantic menhaden were most abundant in mid- and surface water, while spot and Atlantic croaker were most abundant in mid- and deep water. Given this distribution, the inferred advective transport of larvae was at times onshore, but at other times it was offshore. Within a spawning season, the prevalence of either reciprocation could determine the number of larvae that reach coastal inlets.     

TOLERANCE BETWEEN HOST AND DONOR TISSUE IN BIRDS

Two methods were used to develop tolerance in the host toward donor cells. In the first method chicken embryos were joined by the parabiotic union of the chorioallantoic membranes after 9 days of incubation. The second method consisted of the use of embryonic transplants of limb buds from donor embryo to host embryo. These transplants were made after 96 hours of incubation with chicken embryos. Other species used were incubated to comparable development. Both methods were successful in the development of tolerance. However, the degree of tolerance attained varied within each method.     

EFFECT OF 2,4-D AND PICLORAM ON TRANSLOCATION OF 14C-ASSIMILATES IN VITIS VINIEERA L.

Summary. High concentrations of 2,4-D and picloram interfered with the downward movement of ¹⁴c-assimilates infield-grown vines. The interference in translocation was appreciably greater with picloram than it was with 2,4-D, Although basipetal translocation was retarded, translocation within the treated shoots continued from the vegetative part to the clusters. Translocation of 2,4-D appeared to follow the same route as ¹⁴c-assimilatcs for the most part. Formative effects were absent on untreated grape shoots although the adjacent shoots treated with 2,4-D or picloram on the same cordons were killed; however, formative effects were evident on some of the stump sprouts which developed after the vines were harvested. The malformed leaves on the stump sprouts were twelve or more nodes from the base of the shoots, while ¹⁴c was in the more basal leaves.
Thompson Seedless (Sultanina) rootings treated with 20 000 ppm 2,4-D or picloram transported less ¹⁴C to the roots than did the controls. Treatment with either herbicide resulted in a marked increase in the labelling of the stems.
Effet du 2,4-D et du pichlorame sur la migration de métabolites marqués au ¹⁴C dans Vitis vinifera L.