Author index for volume 219

Proteinase inhibitors I and II were purified to electrophoretic homogeneity from leaves of tomato plants induced by either wounding intact plants or by supplying excised plants with the proteinase inhibitor inducing factor. Affinity chromatography with chymotrypsin-Sepharose was employed as a final purification step for each inhibitor. The tomato leaf inhibitors are very similar to potato tuber inhibitors I and II in subunit molecular weight, composition, and inhibitory activities against chymotrypsin, trypsin, and subtilisin. However, unlike the potato tuber which contains multiple isoinhibitors by isoelectric focusing, the tomato leaf exhibits only two isoinhibitor forms of inhibitor I and a single form of inhibitor II. The molecular weight of native potato inhibitor I was reevaluated by rigorous ultracentrifugal analysis and compared with data from previous analyses. The data confirm that native inhibitor I has a native M_r of about 41,000 and is a pentamer. Inhibitor II has a molecular weight of near 23,000 and is a dimer.     

Neuronal precursor cells in the rat hippocampal formation contribute to more than one cytoarchitectonic area.

We have tested the hypothesis that cell lineage restriction boundaries define the borders between cytoarchitectonic areas in the cerebral cortex. Clonally related cells were identified using a retroviral marking technique, and the dispersion of neuronal clones was examined with respect to the transitions between cortical areas. We chose to study the hippocampal formation because we found that clones of hippocampal neurons, unlike those in neocortex, are compact and readily identifiable in the adult and that transitions between areas in the hippocampus are sharp relative to the spread of a typical clone. We conclude, contrary to the hypothesis, that clones of neurons transgress the boundaries between areas in the hippocampal formation, that border-crossing clones are observed as frequently as would be expected if clones spread freely over the hippocampus with no constraint imposed by area borders, and that different types of pyramidal neurons, characteristic of different areas, may appear to a single clone. different areas, may appear in a single clone.     

Metabolic behavior of acetyl glyceryl ether phosphorylcholine on interaction with rabbit platelets

The metabolic fate of 1-O-[³H]alkyl-2-acetyl-sn-glycero-3-phosphorylcholine ([³H]-AGEPC) upon interaction with rabbit platelets was investigated. [³H]AGEPC was converted to a product identified as the long-chain fatty acyl analog. The reaction was unaffected by extracellular calcium. After a lag time of 30 to 60 s the kinetics of the conversion was linear. The rate of the reaction was found to be a function of platelet and AGEPC concentrations. Of the [³H]AGEPC (10^?9m) 85 ± 5% was processed into the-long chain fatty acyl analog within 1 h when incubated at 37 2C with a 1.25 × 10⁹ platelets per milliliter suspension. A maximal number of 1200 to 3600 [³H]AGEPC molecules were converted to the long-chain fatty acyl derivative per minute per platelet in the presence of 2 mm EDTA. Under similar conditions the 1-O-[³H]alkyl-2-(lyso)-sn-glycero-3-phosphorylcholine ([³H]lysoGEPC) also was transformed to a comparable long-chain fatty acyl derivative at a much slower rate and to a lower extent. No significant increase in lysoGEPC was noted in incubation mixtures containing [³H]AGEPC. The possible direct transacylation of AGEPC upon interaction with platelets is discussed as well as the possible involvement of this reaction in directly triggering the platelet response to AGEPC stimuli.     

Suction lipoplasty: biohazardous aerosols and exhaust mist--the clouded issue

With the increased popularity of suction lipoplasty procedures, attention has been focused on their safety. One significant concern involves the rotary vane aspirators used to provide the suction required for the procedure. A series of experiments was carried out to determine whether aerosols are produced during the use of a rotary vane aspirator, since aerosols are known to be hazardous under appropriate conditions. Using a viable strain of Pseudomonas aeruginosa, we challenged the system through the suction port, and the exhaust from the aspirator was then cultured in a particle sampler. Results indicate that viable pathogens are released from the exhaust in physiologically significant particles capable of penetrating to the level of the alveolus in the normal human lung. These infectious particles were produced for 3 hours after the initial challenge. When an appropriate filtration device was attached to the aspirator outflow, the aspirator pump and environment were protected. In the absence of an appropriate filtration device, the aerosolized particles may constitute a hazard to patients or medical workers in the vicinity of the aspirator.