Immune deficiency in the X-linked lymphoproliferative syndrome. I. Epstein-Barr virus-specific defects

Eleven males with XLP were evaluated for EBV-specific antibodies during periods of 2 to 7 yr. Variable responses to EBV-specific antigens were found. All 11 patients had subnormal anti-EBNA titers, which probably reflected a T cell deficiency. The patients showed four different patterns in their anti-VCA response: 1) two boys who had experienced malignant lymphoma mounted no antibodies at all; 2) two patients showed intermittent anti-VCA titers; 3) four males had persistently elevated anti-VCA titers; and 4) three patients showed normal anti-VCA titers. ADCC against EBV-infected cells was abnormally low in six patients and was elevated in two patients given gamma-globulin. ADCC titers did not correlate with anti-VCA titers. However, most patients with XLP failed to effect regression of autologous EBV-infected lymphoblastoid cell lines, indicating a deficiency in long-lived T cell-mediated immunity to EBV.     

The expression of tissue and urokinase-type plasminogen activators in neural development suggests different modes of proteolytic involvement in neuronal growth.

Tissue and urokinase-type plasminogen activators are serine proteases with highly restricted specificity, their best characterised role being to release the broad specificity protease plasmin from inactive plasminogen. It has frequently been suggested that these, and similar proteases, are involved in axonal growth and tissue remodelling associated with neural development. To help define what this role might be, we have studied the expression of the plasminogen activators in developing rat nervous tissue. Urokinase-type plasminogen activator mRNA is strongly expressed by many classes of neurons in peripheral and central nervous system. We have analysed its appearance in spinal cord and sensory ganglia, and found the mRNA is detectable by in situ hybridisation very early in neuronal development (by embryonic day 12.5), at a stage compatible with it playing a role in axonal or dendritic growth. Tissue plasminogen activator mRNA, on the other hand, is expressed only by cells of the floor plate in the developing nervous system, from embryonic day 10.5 and thereafter. Immunohistochemical and enzymatic analysis showed that active tissue plasminogen activator is produced by, and retained within, the floor plate. A mechanism is suggested by which high levels of tissue plasminogen activator produced by the stationary cells of the floor plate could influence the direction of growth of commissural axons as they pass through this midline structure.     

The genetics and expression of an esterase locus inAnopheles gambiae

The main polymorphic system of esterase isoenzymes in adults of the G3 laboratory strain ofAnopheles gambiae consists of two to five major bands of activity per individual. The bands are designated 5S, 5F, 13, 14, and 15. In genetic crosses, the genes which coded for the bands assorted as three codominant alleles, Est A, Est B, and Est C, at a single autosomal locus. Homozygotes for the Est C allele were significantly underrepresented among backcross progeny. The developmental pattern of esterase expression was examined. Esterase gene expression in embryos was first detectable between 2 and 12 hr after oviposition. The initiation or termination of expression of some of the bands corresponded to boundaries between developmental stages. Most of the esterase fractions were not specifically localized within the tissues tested, with the exception of a series of bands which were restricted largely to adult male testes.     

Rapid Activation of Tyrosine Hydroxylase in Response to Nerve Growth Factor

Abstract: Nerve growth factor protein (NGF) was found to rapidly promote the activation of tyrosine hydroxylase in cultured rat PC 12 pheochromocytoma cells. PC 12 cultures were exposed to NGF for periods of less than 1 h and the soluble contents of homogenates prepared from the cells were assayed for tyrosine hydroxylase activity. Under these conditions, the specific enzymatic activity was increased by 60 ± 10% (n = 13) in comparison with that in untreated sister cultures. The increase was half maximal by 2–5 min of exposure and at NGF concentrations of about 10 ng/ml (0.36 n M ). Antiserum against NGF blocked the effect. Tyrosine hydroxylase activity could also be rapidly increased by NGF in cultures of PC12 cells that had been treated with the factor for several weeks in order to produce a neuron-like phenotype. This was achieved by withdrawing NGF for about 4 h and then readding it for 30 min. The NGF-induced increase of tyrosine hydroxylase activity in PC12 cultures was not affected by inhibition of protein synthesis and therefore appeared to be due to activation of the enzyme. Kinetic experiments revealed that NGF brought about no change in the apparent K_m of the enzyme for tyrosine or for co-factor (6-methyltetrahydropteridine), but that it did significantly increase the apparent maximum specific activity of the enzyme. These observations suggest that NGF (perhaps released by target organs) could promote a rapid and local enhancement of noradrenergic transmission in the sympathetic nervous system.     

Seed transmission of turnip yellow mosaic virus in winter turnip and winter oilseed rapes

This is the first record of seed transmission of turnip yellow mosaic virus (TYMV) in oilseed and turnip rapes. The seed transmission of TYMV in a naturally infected winter turnip rape (Brassica napus var. silvestris) cultivar Perko PVH was investigated. By ELISA 1.6%, 3.2% and 8.3% seed transmission of the virus was found in seed of plants from three localities. The proportion of infected seeds produced by artificially infected plants of winter oilseed rape (Brassica napus ssp. oleifera) and winter turnip rape cultivars was determined. The virus transmission rate, expressed as the proportion of virus-infected plants which germinated from the seed was for the oilseed rape cvs Jet Neuf 0.1%, Solida 0.4%, Silesia 0.8%, Darmor 1.2%, SL-507 0.2%, SL-509 0.0% and for the winter turnip rape cv. Perko 1.5%. ELISA cannot be used in direct tests on bulk seed lots to estimate proportion of infected seed, but must be used on germinated seedlings.     

Half-lives of oat mRNAs in vivo and in a polysome-based in-vitro system

We have used a cell-free polysome-based in-vitro mRNA-degradation system to investigate the halflives of plant cell mRNAs. In order to establish the fidelity of the in-vitro system, we used cordycepin to determine the in-vivo half-lives of -tubulin and actin mRNAs in the primary leaves of 4-d-old etiolated oat (Avena sativa L.) seedlings. The in-vitro rank order of half-lives for phytochrome A (45 min), -tubulin (105 min), and actin (220 min) mRNAs mimicked the in-vivo rank order. A pulse of red light given to excised etiolated primary leaves caused an in-vivo reduction in the half-life of -tubulin mRNA. The selectivity of the polysome-based system was further demonstrated by the decrease in the half-life of -tubulin mRNA (from 105 min to 60 min) induced by a pulse of red light given to the etiolated oat seedlings prior to isolation of polysomes. Red light did not affect the apparent half-lives of phytochrome A or actin mRNAs.Abbreviations cab gene for chlorophyll-a/b-binding protein - kb(p) kilobase (pair) - phyA gene for type-I phytochrome protein - rbcS gene for ribulose-1,5-bisphosphate-carboxylase small-subunit We thank Dr. Richard B. Meagher for the pSAc3 actin clone. We thank Dr. Cecil Stewart for the use of his density-gradient fractionator, and Dr. Virginia Crane for instruction in using the fractionator. We also appreciate the helpful comments provided by the other members of the laboratory during the course of this research: Dr. Isaac John, Dr. Iffat Rahim, Linda Barnes, Bruce Held, David Higgs, and Theresa Tirimanne. This work was supported by USDA grants CRGO 88-37261-4196 and 91-37304-6397, and the Iowa State University Biotechnology Program.     

RML1 and RML2, Arabidopsis genes required for cell proliferation at the root tip.

New cells are produced from the meristematic tissues located at the shoot and root tip throughout the life of higher plants. To investigate the genetic mechanism regulating meristematic activity, we isolated and characterized four single-gene, recessive mutants in Arabidopsis thaliana called root meristemless (rml). Complementation tests identified two RML loci; RML1 maps to chromosome IV and RML2 maps to chromosome III. These mutants produce normal embryonic roots that either did not undergo or experienced limited cell division following germination, resulting in primary roots of less than 2.0 mm in length. Mutants can produce lateral and adventitious roots, which can grow to a length comparable to the embryonic root and arrest, indicating that the growth arrest is unrelated to the embryonic dormancy process. Neither the addition of growth regulators to the media nor the removal of shoots can rescue mutant roots from growth arrest, indicating that the mutant phenotype is not caused by a shortage of known growth regulators or by a transmissible shoot inhibitor. Normal cell division ability in mutant embryo, shoot, and callus cells indicates that the RML gene functions are not part of the general cell division processes; rather, they are involved specifically in activating the cell division cycle in the root apical cells.     

Nicotinamide adenine dinucleotide splitting enzyme: a plasma membrane protein of murine macrophages.

The subcellular distribution of NADase in splenic and peritoneal macrophages of the mouse has been studied. Conventional procedures for fractionation and isolation of subcellular components demonstrated that the NADase of murine macrophages was localized in the microsomal fraction. By using the diazonium salt of sulfanilic acid, a nonpenetrating reagent known to inactivate ecto-enzymes in intact cells, purified plasma membrane preparations, and marker enzymes, 5′-nucleotidase for plasma membrane and glucose 6-phosphatase for the microsomal fraction, we have shown that: (i) NADase of murine macrophages is a plasma membrane ecto-enzyme and (ii) the microsomal fraction is a mixture of endoplasmic reticulum and plasma membrane elements. At 5 × 10^?4 M concentration, the diazonium salt of sulfanilic acid drastically decreased NADase in intact splenic and peritoneal macrophages of the mouse. 5′-Nucleotidase was similarly inhibited by this reagent, whereas the activity of glucose 6-phosphatase remained unaffected. There was a good recovery of NADase of high specific activity in plasma membrane preparations that were characterized by high 5′-nucleotidase and low glucose 6-phosphatase activity.     

Aspects of hadrosaurian cranial anatomy

Supraorbital bones in Saurolophus angustirostris are described, and their presence in all hadrosaurs is suggested. Frontal-nasal and premaxillar-nasal fontanellae are distinguished in hadrosaurs; their presence is explained as connected with growth and considered to he responsible for the variability of crest structures. New data indicating the presence of a cartilaginous diverticulum nasi within the circumnarial depression in Saurobphus ongustirostris are presented. A physiological (respiratory and/or thermoregulatory) function of the nasal diverticulum is proposed.     

Inheritance and longevity of infectious pancreatic necrosis virus in the zebra fish, Brachydanio rerio (Hamilton-Buchanan).

Zebra fish (Brachydanio rerio) were injected with infectious pancreatic necrosis virus (IPNV) and then spawned to determine whether the virus was passed on to the eggs, and if it was, how long it remained in the free-swimming F1. The mating variations included parents receiving one or two injections of virus, and within these categories, matings in which both parents were treated or only one parent was treated. The results showed that transmission of IPNV to the egg did occur, and that this transmission was via the female alone. However, if the female was allowed to produce antibodies to the virus, as when she received two injections of IPNV, she transmitted the virus to the eggs for only a short period of time. In addition, when the virus was transmitted to the egg, it remained in the free-swimming F1 for a period of at least 5 months.