Bovine cells expressing bovine herpesvirus 1 (BHV-1) glycoprotein IV resist infection by BHV-1, herpes simplex virus, and pseudorabies virus.

We expressed the bovine herpesvirus 1 (BHV-1) glycoprotein IV (gIV) in bovine cells. The protein expressed was identical in molecular mass and antigenic reactivity to the native gIV protein but was localized in the cytoplasm. Expressing cells were partially resistant to BHV-1, herpes simplex virus, and pseudorabies virus, as shown by a 10- to 1,000-fold-lower number of plaques forming on these cells than on control cells. The level of resistance depended on the level of gIV expression and the type and amount of challenge virus. These data are consistent with previous reports by others that cellular expression of the BHV-1 gIV homologs, herpes simplex virus glycoprotein D, and pseudorabies virus glycoprotein gp50 provide partial resistance against infection with these viruses. We have extended these findings by showing that once BHV-1 enters gIV-expressing cells, it replicates and spreads normally, as shown by the normal size of BHV-1 plaques and the delayed but vigorous synthesis of viral proteins. Our data are consistent with the binding of BHV-1 gIV to a cellular receptor required for initial penetration by all three herpesviruses and interference with the function of that receptor molecule.     

Application of Deuterated A-Tocopherols to the Biokinetics and Bioavailability of Vitamin E

-Tocopherol, a superior chain-breaking, peroxyl radical-trapping antioxidant and the most active component of vitamin E, is elevated in liver tumor cells, contributing to their greater resistance towards lipid peroxidation compared to cells from normal tissues. Also, in regenerating rat liver the level of vitamin E has been found to fluctuate in phase with the rate of cell division. In order to study the biokinetcis and mechanisms of the distribution of vitamin E in organs and within tissues of animals, deuterated forms of -tocopherol have been synthesized and their uptake into blood and tissues has been measured by gas chromatography-mass spectrometry. Measurement of the competitive uptake from a mixture of the RRR-and SRR--tocopherol stereoisomers labelled with different amounts of deuterium shows that the liver exerts a strong preference for secretion of the natural (RRR) stereoisomer into the plasma. It is suggested that a tocopherol-binding protein plays a key role in this process.     

Characterisation of the anti-bladder-cancer monoclonal antibody BLCA-8: Identification of its antigen as a neutral glycolipid

A monoclonal antibody, BLCA-8, was raised against the human bladder cancer cell line, UCRU-BL-17CL. By flow cytometry and immunoperoxidase staining, this antibody was found to possess high specificity for bladder tumours, some reactivity with fetal tissues, and no reactivity with normal bladder, or any normal or malignant tissue. This high specificity and the stability of the antigen to the urinary environment suggest that BLCA-8 may have potential for use as an anti-bladder-cancer therapeutic agent. By thin-layer chromatography and autoradiography, BLCA-8 was found to bind four components within the neutral lipid fraction of a bladder cancer cell line, UCRU-BL-17/23. These components hadR _F values of 0.22, 0.16/0.15 (doublet), 0.12 and 0.08, and migrated below globoside, indicating the presence of more than four sugars. By enzyme-linked immunosorbant assay and thin-layer chromatography it was found that the binding of BLCA-8 to the lipid extract was increased by both mild alkaline hydrolysis and enzymatic treatments, indicating that adjacent phospholipids and glycolipids interfere with the accessibility of the antibody-binding site. Full biochemical characterisation of the BLCA-8 antigen is currently underway.     

Measures of geographic range size: the effects of sample size

A number of methods have been used for quantifying the sizes of the geographic ranges of species. The consequences of different levels of sampling (the proportion of actual spatial occurrences) are explored for eight of these, using data on the occurrences of butterfly species on a 10 × 10 km grid across Britain. For all methods, the percentage error of estimation (PEE) decreases with the number of 10 × 10 km squares which a species occupies, most rapidly for extent measures, and more rapidly for area measures than for measures of numbers of units occupied. The rate of decline in PEE itself falls as sampling effort increases. At a given sampling level, rank correlations between range sizes measured by different methods are generally high, but there is no consistent change in the magnitude of these correlations as the level of sampling increases. The composition of the set of species with the smallest range sizes changes with the level of sampling.     

The genusSavoryella from freshwater habitats,includingS. grandispora sp. nov.

The species ofSavoryella from freshwater are discussed and a key is provided.Savoryella grandispora sp. nov. from Malaysia is described and illustrated with interference contrast micrographs.     

LATE CRETACEOUS FOSSIL FLOWERS OF ERICALEAN AFFINITY

Fossilized flowers of ericalean affinity are reported from the Turanian (ca. 90 MYBP, million years before present) of New Jersey. The fossils are remarkably well preserved and three-dimensional, and are the oldest known floral remains of Ericales. The series of fossil flower buds, floral fragments, and fruits are not identical to any modern genus of Ericales. The inverted U-shaped anthers with pseudoterminal awns, and the fluted syncarpous ovary of the fossils suggest affinities with basal Ericaceae, probably near extant Enkianthus, a taxon that also shares monadinous pollen with the fossil. Pollen grains were observed clumped on a stigma in one of the fossil flowers. Fossilized acid-resistant strands having characteristics, including similar diameter and sculpture pattern, in common with the muri connect pollen grains and, with scanning electron microscopy, appear continuous with the tectum, supporting the interpretation that they are viscin threads. These are the oldest reported fossilized viscin threads, and the only fossilized viscin threads found in situ in flowers. In modern Ericales and Onagraceae, the presence of viscin threads is associated with highly specific plant-pollinator relationships, raising the possibility that such specific pollinator-plant relationships had developed by the mid-Cretaceous. This is consistent with floral characters in these ericalean fossils, the presence of advanced meliponine bees in slightly younger sediments from the same region, and with the morphology and affinities of other fossil flowers from the same sediments.     

Calcium-independent activation of skeletal muscle fibers by a modified form of cardiac troponin C.

A conformational change accompanying Ca2+ binding to troponin C (TnC) constitutes the initial event in contractile regulation of vertebrate striated muscle. We replaced endogenous TnC in single skinned fibers from rabbit psoas muscle with a modified form of cardiac TnC (cTnC) which, unlike native cTnC, probably contains an intramolecular disulfide bond. We found that such activating TnC (aTnC) enables force generation and shortening in the absence of calcium. With aTnC, both force and shortening velocity were the same at pCa 9.2 and pCa 4.0. aTnc could not be extracted under conditions which resulted in extraction of endogenous TnC. Thus, aTnC provides a stable model for structural studies of a calcium binding protein in the active conformation as well as a useful tool for physiological studies on the primary and secondary effects of Ca2+ on the molecular kinetics of muscle contraction.     

Expression of the Cytoskeletal-Associated Protein Filamin in Adult Rat Organs

Filamin is a well-characterized actin-associated protein first isolated from chicken smooth muscle. Subsequently, this polypeptide and its nonmuscle homolog actin-binding protein have been shown to be expressed in avian muscle tissue, mammalian smooth muscle, mammalian macrophages and other blood cell types, as well as several cultured cell lines. In this report, the occurrence of this polypeptide in adult mammalian organs has been investigated. Immunoblot analysis using three anti-filamin monoclonal antibodies showed that this protein was largely detected in adult rat organs that possess a substantial smooth muscle component. Furthermore, the limited expression of filamin in smooth muscle tissue was corroborated by immunohistochemical analysis. In contrast to avian systems, filamin was never found in detectable quantities in either mammalian cardiac or skeletal muscle. Quantitative immunoblot analysis demonstrated that filamin amounts roughly correlated with the abundance of the smooth muscle component of a given organ, comprising as much as 16.5% of the total SDS-extractable protein in bovine aorta. Work in avian systems and cells in culture has suggested that filamin is a rather ubiquitous cytoskeletal element. By contrast, this work demonstrates that filamin is highly restricted in its expression in mammalian organ systems, in situ.