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Easter lily bulbs for greenhouse forcing are produced in Del Norte County, California and Curry County, Oregon, USA. Pratylenchus penetransinfestation seriously affects growth of field grown bulbs. During two consecutive years of field trials containing 22 treatments, commercially prepared formulations of essential oils (EOs) were compared to an untreated control and to a standard chemical fumigant treatment (FU) (1,3-dichloropropene and metam sodium) applied preplant followed by phorate (PH) at planting to determine their value in the management of lesion nematode, and in improving plant health. The EO products Duogard, EF400, EF300, and Cinnamite were tested as preplant dips to bulblet planting stock. The treated bulblets were tested either alone, in combination with PH at-planting, at planting following FU or in combination with PH at planting following FU. The organophosphates ethoprop and fosthiazate were also tested either alone, or at a reduced rate in combination with a reduced rate of PH. With respect to bulb circumference, ten treatments consistently outperformed the control. In consecutive years, three treatments had healthier looking roots than the control. At harvest, levels of lesion nematode within roots were consistently lower in nine treatments. EOs were beneficial in mitigating nematode damage.

Lipophilic and hydrophilic dendra which are terminated with long alkyl chains and oligomeric poly(ethylene glycol) moieties, respectively, were synthesized, and these dendron species were used to functionalize single-wall (SWNT) and multiple-wall (MWNT) carbon nanotubes via amidation and esterification reactions. The functionalized carbon nanotube samples are, depending on the functionalities, soluble in common organic solvents, such as hexane and chloroform, and water to form colored homogeneous solutions. Characterizations using NMR, electron microscopy, and optical spectroscopic techniques show that the homogeneous solutions contain carbon nanotubes. A preliminary understanding of the structural features and properties of these soluble dendron-functionalized SWNTs and MWNTs is discussed in terms of results from the characterizations, the defunctionalization reactions, and the trapping of metal nanoparticles by the functionalized nanotubes in solution.

The major envelope glycoprotein, gp120, of human immunodeficiency virus type 1 (HIV-1) was purified from a Chinese hamster ovary cell line transfected with a truncated form of the HIV-1 env gene. The recombinant glycoprotein (rgp120) was formulated with aluminum hydroxide adjuvant and was used to immunize chimpanzees. The recombinant preparation was effective in eliciting cellular and humoral immunity as well as immunologic memory. Anti-rgp 120 antibodies reacted with authentic viral gp120 in immunological blot assays and were able to neutralize HIV-1 infectivity in vitro. Sera from the rgp120-immunized animals were able to neutralize HIV-1 pseudotypes of vesicular stomatitis virus prepared from the IIIB isolate, from which the gene encoding rgp120 was derived, as well as two heterologous isolates, ARV-2 and RF. The immune response elicited against the rgp120 was not effective in preventing viral infection after intravenous challenge with HIV-1. The implications of these results on HIV-1 vaccine development are discussed.

A medium for the accumulation of extracellular hemolysin (300 to 1,600 hemolytic units per ml) and protease (2 to 3 proteolytic units per ml) was developed for an anaerogenic strain of Aeromonas hydrophila. In this medium, growth yields were less but levels of accumulated toxin were greater or equivalent when compared with the same responses in brain heart infusion and nutrient broths. The medium was considered to be partially defined since the conditions for maximum observed hemolysin accumulation (1,600 hemolysin units per ml) were not identified. The results showed that iron and zinc contributed to the control of the extracellular accumulation of both toxins. Whereas iron exerted an inhibitory effect, zinc stimulated the accumulation of both toxins.

A soluble form of recombinant gp120 of human immunodeficiency virus type 1 was used as an immunogen for production of murine monoclonal antibodies. These monoclonal antibodies were characterized for their ability to block the interaction between gp120 and the acquired immunodeficiency syndrome virus receptor, CD4. Three of the monoclonal antibodies were found to inhibit this interaction, whereas the other antibodies were found to be ineffective at blocking binding. The gp120 epitopes which are recognized by these monoclonal antibodies were mapped by using a combination of Western blot (immunoblot) analysis of gp120 proteolytic fragments, immunoaffinity purification of fragments of gp120, and antibody screening of a random gp120 gene fragment expression library produced in the lambda gt11 expression system. Two monoclonal antibodies which blocked gp120-CD4 interaction were found to map to adjacent sites in the carboxy-terminal region of the glycoprotein, suggesting that this area is important in the interaction between gp120 and CD4. One nonblocking antibody was found to map to a position that was C terminal to this CD4 blocking region. Interestingly, the other nonblocking monoclonal antibodies were found to map either to a highly conserved region in the central part of the gp120 polypeptide or to a highly conserved region near the N terminus of the glycoprotein. N-terminal deletion mutants of the soluble envelope glycoprotein which lack these highly conserved domains but maintain the C-terminal CD4 interaction sites were unable to bind tightly to the CD4 receptor. These results suggest that although the N-terminal and central conserved domains of intact gp120 do not appear to be directly required for CD4 binding, they may contain information that allows other parts of the molecule to form the appropriate structure for CD4 interaction.

Recently, complete human factor VIII DNA clones have been obtained and subsequently expressed in baby hamster kidney cells (Wood, W. I., Capon, D. J., Simonsen, C. C., Eaton, D. L., Gitschier, J., Keyt, B., Seeburg, P. H., Smith, D. H., Hollingshead, P., Wion, K. L., Delwart, E., Tuddenham, E. G. D., Vehar, G. A., and Lawn, R. M. (1984) Nature 312, 330-337). The recombinant factor VIII (rVIII) protein secreted from these cells has now been purified allowing its structural analysis and comparison to plasma-derived factor VIII (pdVIII). Analysis of purified rVIII by sodium dodecyl sulfate-polyacrylamide gel electrophoresis shows that it consists of multiple polypeptides with relative mobilities (Mr) ranging from 80,000-210,000. The same pattern of polypeptides is also observed for pdVIII resolved by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The proteins associated with rVIII are recognized by pdVIII antibodies in a Western blot. When rVIII and pdVIII are subjected to isoelectric focusing they are resolved into a similar pattern of protein bands. Thrombin, factor Xa, and activated protein C, which modulate factor VIII activity by proteolysis, process rVIII in the same manner they do pdVIII. As is the case for pdVIII, thrombin activation of rVIII coagulant activity correlates with the generation of subunits with Mr of 73,000, 50,000 and 43,000. These subunits appear to form a metal-(perhaps Ca2+) linked complex. EDTA inactivates thrombin-activated rVIII and pdVIII, with the activity being regenerated after the addition of a molar excess of MnCl2. The results suggest that rVIII is structurally and functionally very similar to pdVIII.

The effects of the extracellular products (ECP) and endotoxin from Aeromonas hydrophila grown in a defined medium were determined following intraperitoneal injection of young-of-the-year channel catfish Ictalurus punctatus. Endotoxin had no lethal effects in doses as high as 400 µg per 7.2-g fish, whereas ECP had a 48-hour median lethal concentration (LD50) of 15.7 µg per 7.2-g fish. Sublethal doses of ECP often produced many of the gross pathologies associated with A. hydrophila infections. The primary lethal factor was heat-labile at 56 C for 10 minutes, but a heat-stable component was also implicated.

The envelope glycoprotein of human immunodeficiency virus type 1 is synthesized as a precursor, gp160, that subsequently is cleaved to yield mature gp120 and gp41. In these studies, the gene encoding gp160 was mutagenized so as direct the synthesis of a truncated protein consisting of the extracellular domains of both gp120 and gp41. The variant protein, termed sgp160, consisted of 458 amino acids of gp120 and 172 amino acids of gp41. To facilitate protein purification, the normal polyglycoprotein processing site between gp120 and gp41 was deleted through the use of site-directed mutagenesis. This allowed for the synthesis of a molecule that could be purified by affinity chromatography, using acid elution, without dissociation of the gp120 polypeptide from the gp41 polypeptide. The conformation of the sgp160 variant appeared to be functionally relevant, as reflected by its ability to bind to CD4 with an affinity comparable to that of the variant rgp120. The structure of the sgp160-containing polypeptide differed from that of rgp120 in that it tended to form high-molecular-weight aggregates that could be dissociated to monomers and dimers in the presence of reducing agents. Antibodies against the sgp160 protein reacted with authentic virus-derived gp160, gp120, and gp41; neutralized viral infectivity; and inhibited the binding of rgp120 to CD4. Rabbit antibodies to the sgp160 protein differed from those raised against rgp120 in that they were enriched for populations that blocked CD4 binding but did not prevent human immunodeficiency virus type 1-induced syncytium formation.

Extracellular products from Aeromonas hydrophila strain 22 grown in a defined medium were lethal to young-of-the-year channel catfish Ictalurus punctatus. No detectable hemolysin was produced, but partial purification and characterization of the extracellular products suggested that the lethal factors were proteases. The median lethal dose (LD50) of a heat-labile protease fraction was 18.0 µg protein per gram of fish. A heat-stable protease fraction gave an LD50 of 3.0 µg protein per gram of fish.

Soluble samples of single-wall and multiple-wall carbon nanotubes that are functionalized by lipophilic and hydrophilic dendra can be defunctionalized in homogeneous solutions under base- and acid-catalyzed hydrolysis reaction conditions. The results provide strong evidence for the ester linkages in the functionalization of carbon nanotubes.