A human monoclonal antibody to cytomegalovirus (CMV)

We report the development of a human monoclonal antibody to cytomegalovirus (CMV) produced from a human X human hybridoma. This hybrid was developed by fusion of an EBV-transformed cell line making antibody to CMV and a human lymphoblastoid cell line WI-L2. The antibody is directed to a CMV-specific antigen primarily in the nucleus of CMV-infected human fibroblasts. It cross-reacts with at least 10 different strains of CMV and may provide a method for the rapid in vitro diagnosis of CMV infections. The production of CMV-specific human man monoclonal antibodies from human-human hybridomas for future therapeutic use is now technically feasible with this specific method of production.     

Microbial fermentative preparation of L-[15N2]lysine and its tracer: application to serum amino acid kinetic studies

The microorganism Brevibacterium flavum 21129 has been used to produce multigram batches of L-[15N2]lysine of high purity and isotopic enrichment by supplementation of the growth medium with (15NH4)2SO4 of 98.0 atom% excess. The doubly 15N-labeled lysine can be detected at dilutions 10 times greater than singly labeled lysine when isotope dilution curves are analyzed by gas chromatography-mass spectrometry. This enhanced sensitivity permits kinetic measurements of plasma free-lysine isotope content over a 300-fold dilution during 6 h following a single oral bolus of 5 mg/kg body wt. This inexpensive preparation method lends itself to the production of highly useful biochemical compounds for kinetic studies of human nutrition.     

The effects of ultraviolet-B radiation on plant competition in terrestrial ecosystems

Evidence regarding the interaction of ultraviolet-B (UV-B, 280-320 nm) radiation and plant competition in terrestrial ecosystems is examined. The competitive interactions of some species pairs were affected even by ambient solar UV-B radiation (as exists without ozone depletion), when compared to control pairs grown without UV-B. Also, the total shoot biomass of these species pairs was depressed under ambient UV-B. Relatively large increases in UV-B radiation (approximating a 40% ozone layer reduction when weighted with the generalized plant action spectrum) altered the competitive interactions of some species pairs grown in pots under field conditions, but did not affect the total shoot biomass production of those pairs. Recent field experiments have examined the competitive interactions of wheat ( Triticum aestivum L. cv. Bannock) and wild oat ( Avena fatua L.) under a simulated increased UV-B regime resulting from a 16% ozone layer reduction when weighted with the generalized plant action spectrum. This increase in UV-B altered the competitive interactions of these two species without affecting the total shoot biomass production of the species pair. The manner in which increased UV-B affected the relative competitive abilities of the two species was highly dependent upon the environmental conditions during the early life stages of the plants. The implications of these results for both agricultural and natural plant communities are discussed.     

Protein kinase from Mucor rouxii

Summary Cyclic AMP binding to Mucor rouxii protein kinase holoenzyme and free regulatory subunit was measured by the classical membrane filtration technique and by equilibrium dialysis. The results obtained demonstrate that the filtration method can be used without loss of any cyclic AMP binding site. Both methods unambiguously demonstrate that the number of molecules of cyclic AMP bound to the holoenzyme are half of those bound to the regulatory subunit. This result suggests that unshielding of new cyclic AMP binding sites occurs upon dissociation of the ternary complex holoenzyme-cyclic AMP.     

Translation of the UGA triplet in vitro by tryptophan transfer RNA's

Tryptophan transfer RNA from the UGA-suppressing strain of Escherichia coli CAJ64 was purified and assayed for suppressor activity in vitro in two ways: by translation of the bacteriophage T4 lysozyme messenger RNA bearing a UGA mutation, and by translation of poly(U-G-A). Purified tRNA^Trp, and no other fraction, stimulates lysozyme synthesis 30-fold above the level seen when comparable amounts of tryptophan tRNA from the non-suppressing strain, CA244, were added; it also translates poly(U-G-A) as polytryptophan more efficiently than the su⁻ tRNA. Tryptophan tRNA from the non-suppressing strain is active in the assays but far less so than CAJ64 tRNA^Trp, and this is consistent with the leakiness of su⁻ strains. Since the nucleotide sequences of these tryptophan tRNA's are known (Hirsh, 1971), it is concluded that tRNA with a CCA anticodon recognizes the UGA triplet and this recognition is improved by a nucleotide change elsewhere in the molecule.     

Psychological Sequelae of Accidental Injury: A Medico-Legal Quagmire

Litigation for personal injury following accidental trauma is an expensive and confused process involving three protagonists: patient, doctor and lawyer. Although post-traumatic conditions can be elaborately classified, the intrinsic validity of such classifications is often questionable. Current methods of evaluating psychological sequelae of accidental injury are inaccurate and unsatisfactory, partly because of the protagonists'' conceptual, motivational and semantic differences. In addition, there is no really satisfactory method of (a) determining and quantifying minor but significant degrees of brain damage, (b) distinguishing these from “post-traumatic neurosis”, or (c) determining the relationship between the trauma and subsequent disturbance of function. Increasingly “expert” advice is solicited but owing to the nature of the data and conditions of examination, such advice does little to clarify the underlying problems. Furthermore, doctors are often unable to communicate effectively to the judiciary just how the trauma has affected the patient. Even though certain suggestions for improvement are advanced, the need for comprehensive, longitudinal research is inescapable.     

Two better cell lines for making hybridomas expressing specific T cell receptors

Two variants of the AKR thymoma BW5147 have been isolated which can no longer express functional TCR alpha- and beta-chains. By generating hybridomas with these variant fusion lines, TCR of any normal T lymphocyte, including TCR-gamma/delta, can be studied at a clonal level, without interference of the BW5147-derived receptor chains. In this study one of the variants has been useful in identifying the reactivity to allogeneic MHC Ag of BW5147 itself.     

Induction of anchorage-independent growth in human diploid fibroblasts by the cyclopenta-polycyclic aromatic hydrocarbon, benz[l]aceanthrylene

Cyclopenta-fused polycyclic aromatic hydrocarbons are a class of environmental PAH that have been recently identified. Many of these chemicals have been found to be more active than benzo[a]pyrene in tests for genetic toxicity using bacterial and rodent cells. Benz[l]aceanthrylene, a cyclopenta-polycyclic aromatic hydrocarbon related to benz[a]anthracene, and benzo[a]pyrene were compared for their activity to induce cytotoxicity and anchorage-independent growth with normal human diploid fibroblasts. Both benz[l]aceanthrylene and benzo[a]pyrene were relatively non-cytotoxic to normal human diploid fibroblasts. However, benz[l]aceanthrylene was twice as active compared to benzo[a]pyrene over the concentration range examined as an inducer of anchorage-independent growth. The ability of benz[l]aceanthrylene to induce anchorage-independent colony growth in normal human cells, in combination with its demonstrated ability as a mouse-skin tumorigen, suggests this PAH to be a potential multi-species carcinogen.     

Degradation of azo dyes by the lignin-degrading fungus Phanerochaete chrysosporium.

Under nitrogen-limiting, secondary metabolic conditions, the white rot basidiomycete Phanerochaete chrysosporium extensively mineralized the specifically 14C-ring-labeled azo dyes 4-phenylazophenol, 4-phenylazo-2-methoxyphenol, Disperse Yellow 3 [2-(4'-acetamidophenylazo)-4-methylphenol], 4-phenylazoaniline, N,N-dimethyl-4-phenylazoaniline, Disperse Orange 3 [4-(4'-nitrophenylazo)-aniline], and Solvent Yellow 14 (1-phenylazo-2-naphthol). Twelve days after addition to cultures, the dyes had been mineralized 23.1 to 48.1%. Aromatic rings with substituents such as hydroxyl, amino, acetamido, or nitro functions were mineralized to a greater extent than unsubstituted rings. Most of the dyes were degraded extensively only under nitrogen-limiting, ligninolytic conditions. However, 4-phenylazo-[U-14C]phenol and 4-phenylazo-[U-14C]2-methoxyphenol were mineralized to a lesser extent under nitrogen-sufficient, nonligninolytic conditions as well. These results suggest that P. chrysosporium has potential applications for the cleanup of textile mill effluents and for the bioremediation of dye-contaminated soil.     

The β4Integrin Subunit Is Expressed in Mouse Fibroblasts and Modulated by Transforming Growth Factor-β1

Integrin β₄subunit is present in association with α₆chain on both normal and transformed epithelial cells. Recently α₆β₄heterodimer was found on the endothelium of medium-sized blood vessels and on immature thymocytes. In this report we show, by Northern blotting, indirect immunofluorescence, immunoprecipitation, and Western blotting, that β₄subunit is expressed also on cells of mesenchymal origin such as fibroblasts, myoblasts, and myotubes. Increased expression of α₆β₄has been related to the aggressive metastatic phenotype of human and murine carcinomas. The transforming growth factor β₁(TGF-β₁) has been found to modulate the expression of several integrins and intracellular matrix proteins, as well as to stimulate cell invasion and metastatic potential. To evaluate whether α₆β₄expression is modulated by TGF-β₁, we transfected 3T3 fibroblasts with an expression vector carrying the human TGF-β₁cDNA driven by the SV40 early promoter. We observed by indirect immunofluorescence a modification in the subcellular distribution of β₄subunit, which acquires a perinuclear localization. This finding suggests this integrin subunit correlates with the cytoskeletal reorganization induced by TGF-β₁.