Crystal structure of the complex of a catalytic antibody Fab fragment with a transition state analog: structural similarities in esterase-like catalytic antibodies.

The x-ray structure of the complex of a catalytic antibody Fab fragment with a phosphonate transition-state analog has been determined. The antibody (CNJ206) catalyzes the hydrolysis of p-nitrophenyl esters with significant rate enhancement and substrate specificity. Comparison of this structure with that of the uncomplexed Fab fragment suggests hapten-induced conformational changes: the shape of the combining site changes from a shallow groove in the uncomplexed Fab to a deep pocket where the hapten is buried.

Identification of bovine T cell stimulatory antigens using a cosmid library of Mycobacterium bovis in Mycobacterium smegmatis.

Culture filtrates derived from a Mycobacterium bovis cosmid library in Mycobacterium smegmatis were screened for T cell antigens. Recognition and reactivity were measured by the levels of lymphocyte proliferation and the levels of gamma interferon (IFN-gamma) produced when the culture filtrates were incubated with peripheral blood mononuclear cells (PBMC) taken from cattle immunised with M. bovis BCG.

Oral transmucosal fentanyl citrate for preanaesthetic medication of paediatric cardiac surgery patients.

The safety and efficacy of oral transmucosal fentanyl citrate (OTFC) as a preanaesthetic medication were evaluated in 42 children aged two to twelve years scheduled to undergo general anaesthesia for open cardiac surgery. Patients were randomly assigned to receive either a placebo lozenge or a lozenge of 15-20 micrograms.kg-1) OTFC 45 min preoperatively and were managed in a double-blinded manner.

Amino Acid Cycling in Colonies of the Planktonic Marine Cyanobacterium Trichodesmium thiebautii.

We examined diel trends in internal pools and net efflux of free amino acids in colonies of the nonheterocystous, diazotrophic cyanobacterium Trichodesmium thiebautii, freshly collected from waters of the Caribbean and the Bahamas. The kinetics of glutamate uptake by whole colonies were also examined. While intracolonial pools of most free amino acids were relatively constant through the day, pools of glutamate and glutamine varied over the diel cycle, with maxima during the early afternoon.

IFN-gamma, TNF, and IL-6 production by vaccinia virus immune spleen cells. An in vitro study.

The production of cytokines by virus immune spleen cells after in vitro restimulation was investigated. Vaccinia virus-primed spleen cells from CBA/H mice were stimulated in vitro with virus-infected UV-irradiated syngeneic cells. Both CD4+ and CD8+ T cell populations proliferated after restimulation.

Microcrystals of the beta 1 isoenzyme of protein kinase C: an electron microscopic study.

Microcrystals of protein kinase C beta 1 have been grown from solutions of poly(ethylene glycol). Image analysis of electron micrographs of the protein crystals, which diffracted to 5.0 nm, revealed p3 symmetry with a unit cell of about 10.

Cytochrome Oxidase: Subcellular Distribution and Relationship to Nitrogenase Expression in the Nonheterocystous Marine Cyanobacterium Trichodesmium thiebautii.

Immunochemical labeling was used to study the subcellular distribution of cytochrome oxidase, a respiratory protein, in Trichodesmium thiebautii. The protein was found associated with both cytoplasmic and thylakoid membranes. About a sixfold variation in the protein content (gold particle count) was found among Trichodesmium cells within a single colony.

Loss of Hox-A1 (Hox-1.6) function results in the reorganization of the murine hindbrain.

Targeted disruption of the murine hox-A1 gene results in severe defects in the formation of the hindbrain and associated cranial ganglia and nerves. Carbocyanine dye injections were used to trace afferent and efferent projections to and from the hindbrain in hox-A1-/hox-A1- mutant mice. Defects were observed in the position of efferent neurons in the hindbrain and in their projection patterns.

Glutamine synthetase and nitrogen cycling in colonies of the marine diazotrophic cyanobacteria Trichodesmium spp.

We examined freshly collected samples of the colonial planktonic cyanobacterium Trichodesmium thiebautii to determine the pathways of recently fixed N within and among trichomes. High concentrations of glutamate and glutamine were found in colonies. Glutamate and glutamine uptake rates and concentrations in cells were low in the early morning and increased in the late morning to reach maxima near midday; then uptake and concentration again fell to low values.

Ultrastructural and chemical assessment of poly-beta-hydroxybutyric acid in the marine cyanobacterium Trichodesmium thiebautii.

We report here on the occurrence and quantities of poly-beta-hydroxybutyric acid (PHB) in natural populations of the marine cyanobacterium Trichodesmium thiebautii. A diurnal variation in the shape and size of PHB granules and in PHB content was observed. The highest PHB levels (2.

The distribution of neural crest-derived Schwann cells from subsets of brachial spinal segments into the peripheral nerves innervating the chick forelimb.

Neural crest cells from brachial levels of the neural tube populate the ventral roots, spinal nerves, and peripheral nerves of the chick forelimb where they give rise to Schwann cells. The distribution of neural crest cells in the developing forelimb was examined using homotopic and heterotopic chick-quail chimeras to label neural crest cells from subsets of the brachial spinal segments. Neural crest cells from particular regions of the spinal cord populated ventral roots and spinal nerves adjacent to or immediately posterior to the graft.

The location and distribution of neural crest-derived Schwann cells in developing peripheral nerves in the chick forelimb.

The location and distribution of neural crest-derived Schwann cells during development of the peripheral nerves of chick forelimbs were examined using chick-quail chimeras. Neural crest cells were labeled by transplantation of the dorsal part of the neural tube from a quail donor to a chick host at levels of the neural tube destined to give rise to brachial innervation. The ventral roots, spinal nerves, and peripheral nerves innervating the chick forelimb were examined for the presence of quail-derived neural crest cells at several stages of embryonic development.

Major role of the cyanobacterium trichodesmium in nutrient cycling in the north atlantic ocean.

The diazotrophic cyanobacterium Trichodesmium is a large (about 0.5 by 3 millimeters) phytoplankter that is common in tropical open-ocean waters. Measurements of abundance, plus a review of earlier observations, indicate that it, rather than the picophytoplankton, is the most important primary producer (about 165 milligrams of carbon per square meter per day) in the tropical North Atlantic Ocean.

Developmental expression of REGA-1, a regionally expressed glial antigen in the central nervous system of grasshopper embryos.

Glial cells are a large component of the developing nervous system, appearing before the onset of axon outgrowth in a variety of developing systems. Their time of appearance and their location in conjunction with developing axon pathways may allow them to define the position of axon pathways. Specific glial cells may be utilized as guideposts by growing axons, allowing them to recognize the appropriate pathway, or conversely, glial cells may inhibit axons from growing along an inappropriate pathway.

Basis for Diel Variation in Nitrogenase Activity in the Marine Planktonic Cyanobacterium Trichodesmium thiebautii.

Natural populations of the nonheterocystous marine cyanobacterium Trichodesmium thiebautii exhibit a diel periodicity in nitrogenase activity (NA). NA "turns on" near dawn and "turns off" near dusk, independent of photic conditions. Chloramphenicol (CAP) and ammonium prevented turn on of NA in T.

Conservation and variation in orf virus genomes.

The genomes of several orf virus strains were analyzed with the restriction endonucleases EcoRI, HindIII, BamHI, and KpnI, and cleavage site maps were deduced. In general, the right half of the genome showed conservation of restriction sites compared with the left half. Variations in size of up to 0.

Gender hierarchies in the health labor force.

Rapid growth and increasing diversity characterize trends of the U.S. health labor force in recent decades.

Pictures in sentences: understanding without words.

To understand a sentence, the meanings of the words in the sentence must be retrieved and combined. Are these meanings represented within the language system (the lexical hypothesis) or are they represented in a general conceptual system that is not restricted to language (the conceptual hypothesis)? To evaluate these hypotheses, sentences were presented in which a pictured object replaced a word (rebus sentences). Previous research has shown that isolated pictures and words are processed equally rapidly in conceptual tasks, but that pictures are markedly slower than words in tasks requiring lexical access.