Nuclear receptors have distinct affinities for coactivators: characterization by fluorescence resonance energy transfer.

Unlabelled: Ligand-dependent interactions between nuclear receptors and members of a family of nuclear receptor coactivators are associated with transcriptional activation. Here we used fluorescence resonance energy transfer (FRET) as an approach for detecting and quantitating such interactions. Using the ligand binding domain (LBD) of peroxisome proliferator-activated receptor (PPARgamma) as a model, known agonists (thiazolidinediones and delta12, 14-PGJ2) induced a specific interaction resulting in FRET between the fluorescently labeled LBD and fluorescently labeled coactivators [CREB-binding protein (CBP) or steroid receptor coactivator-1 (SRC-1)].

High basal gastric acid secretion in somatostatin receptor subtype 2 knockout mice.

Background & Aims: Somatostatin receptor subtype 2 (sst2) agonists inhibit gastric secretion. The role of sst2 in the regulation of acid secretion was assessed using sst2 knockout mice and urethane to induce somatostatin release.

Methods: Acid secretion was monitored every 10 minutes by gastric perfusion and backtitration of perfusates in fasted, urethane-anesthetized C57/129 sst2 (-/-) mice and wild-type (+/+) mice.

Endophytic fungi in indigenous Australasian grasses associated with toxicity to livestock.

Grazing of Echinopogon spp. by livestock in Australia has caused symptoms similar to those of perennial ryegrass staggers. We observed an endophytic fungus in the intercellular spaces of the leaves and seeds of New Zealand and Australian specimens of Echinopogon ovatus.

Protein kinase inhibition in G2 causes mammalian Mcm proteins to reassociate with chromatin and restores ability to replicate.

Intact nuclei from G2-phase mammalian cells will replicate their DNA in Xenopus egg extract if they are preexposed to the protein kinase inhibitor 6-dimethylaminopurine in vivo (Coverley et al., Exp. Cell Res.

Genetic and biochemical evidence for a novel avermectin-sensitive chloride channel in Caenorhabditis elegans. Isolation and characterization.

Avermectins are a class of macrocyclic lactones that is widely used in crop protection and to treat helminth infections in man and animals. Two complementary DNAs (GluClalpha and GluClbeta) encoding chloride channels that are gated by avermectin and glutamate, respectively, were isolated from Caenorhabditis elegans. To study the role of these subunits in conferring avermectin sensitivity we isolated a mutant C.

Differentially regulated inhibitor-sensitive and insensitive protease genes from the phytophagous insect pest, Helicoverpa armigera, are members of complex multigene families.

Ingestion of soybean Kunitz trypsin inhibitor (SKTI) by larvae of the phytophagous insect pest Helicoverpa armigera induced production of inhibitor-insensitive protease activity. The induced activity was not due to proteolytic enzymes of different mechanistic classes, but rather to variants of the existing enzymes. Characterization of cDNAs showed that sequences encoding proteins of the serine protease family were abundant in gut tissue of both control and SKTI-fed insects.

Hypercalcaemia in osteogenesis imperfecta treated with pamidronate.

The response to the bisphosphonate, pamidronate, is reported in a child with osteogenesis imperfecta who had recurrent symptomatic hypercalcaemia after immobilisation following fractures. Oral clodronate was effective in the prevention of immobilisation hypercalcaemia in the same child. The bisphosphonates may have other roles in osteogenesis imperfecta by decreasing bone turnover.

Symbiotic specialization and the potential for genotypic coexistence in a plant-bacterial mutualism.

Genotypes of the annual legume Amphicarpaea bracteata vary in their degree of specialization toward different nitrogen-fixing bacteria. Plants of lineages "Ib" and "II" are specialized for mutualism with a limited group of bacterial genotypes. Lineage "Ia" plants are symbiotic generalists, interacting with all bacteria associated with specialist (Ib and II) plants, and also with a distinct class of bacteria that only fix nitrogen with lineage Ia plants.

DIVERGENCE IN SYMBIOTIC COMPATIBILITY IN A LEGUME-BRADYRHIZOBIUM MUTUALISM.

Geographic variation in the mutualism between the legume Amphicarpaea bracteata and its nitrogen-fixing root nodule bacteria (Bradyrhizobium sp.) was analyzed by sampling genotypes from 11 sites separated by distances ranging from 0.6 km to more than 1000 km.

A protein kinase-dependent block to reinitiation of DNA replication in G2 phase in mammalian cells.

Eukaryotic cells normally replicate their DNA only once between mitoses. Unlike G1 nuclei, intact G2 nuclei do not replicate during incubation in Xenopus egg extract. However, artificial permeabilization of the nuclear membrane of G2 nuclei allows induction of new initiations by Xenopus egg extract.

Percutaneous radiofrequency upper thoracic sympathectomy.

Between June 1979 and May 1994, I performed 148 unilateral or bilateral sympathectomies on 247 limbs in 110 patients using a percutaneous radiofrequency technique, usually on an outpatient surgery basis. Patient ages ranged from 10 to 81 years, with 45 male and 65 female patients. Four patients had unsuccessfully undergone prior open surgical sympathectomy.

NONRANDOM GENOTYPIC ASSOCIATIONS IN A LEGUME-BRADYRHIZOBIUM MUTUALISM.

Genetically divergent lineages often coexist within populations of the annual legume Amphicarpaea bracteata. At one site dominated by two such lineages (termed biotypes "C" and "S"), isolates of root-nodule bacteria (Bradyrhizobium sp.) were sampled from both hosts and analyzed by enzyme electrophoresis.

Molecular biology and electrophysiology of glutamate-gated chloride channels of invertebrates.

In this chapter we summarize the available data on a novel class of ligand-gated anion channels that are gated by the neurotransmitter glutamate. Glutamate is classically thought to be a stimulatory neurotransmitter, however, studies in invertebrates have proven that glutamate also functions as an inhibitory ligand. The bulk of studies conducted in vivo have been on insects and crustaceans, where glutamate was first postulated to act on H-receptors resulting in a hyperpolarizing response to glutamate.

Spatial and temporal patterns of lin-12 expression during C. elegans hermaphrodite development.

The lin-12 gene encodes a receptor that mediates certain cell-cell interactions during Caenorhabditis elegans development. We have examined the expression of a lin-12::lacZ reporter gene in individual cells during the development of C. elegans hermaphrodites.

Limited role for intraoperative intact PTH measurement in parathyroid surgery.

Primary hyperparathyroidism may be cured surgically by complete excision of abnormal parathyroid tissue. Reoperation for persistent hypercalcaemia due to residual abnormal parathyroid tissue may be associated with a high complication rate. It is possible to assay intact parathormone (iPTH) intraoperatively and as iPTH has a relatively short half-life, its measurement intraoperatively may be used to predict successful parathyroidectomy.

Reciprocal changes in expression of the receptor lin-12 and its ligand lag-2 prior to commitment in a C. elegans cell fate decision.

During development of the C. elegans hermaphrodite gonad, two cells interact with each other, so that one chooses to become the anchor cell (AC) and the other becomes a ventral uterine precursor cell (VU). This interaction is mediated by the receptor LIN-12 and its apparent ligand LAG-2.

Population fluctuations of three nematode genera in putting greens in northern illinois.

Field experiments were conducted in 1989 and 1990 to examine the population fluctuation patterns of Tylenchorhynchus nudus, Criconemella curvata, and Helicotylenchus cornurus in mixed bentgrass and annual bluegrass putting greens on two golf courses near Chicago, Illinois, to determine if fluctuation patterns could be extrapolated to unsampled greens. Fenamiphos-treated and untreated plots were established on seven putting greens on two golf courses. Greens were sampled intensively five times during the growing season, and statistical comparisons of population levels per gram of root were made among dates for each green.

Vertical distribution of three nematode genera in a bentgrass putting green in central illinois.

A study was conducted to determine the vertical distribution of Tylenchorhynchus nudus, Criconemella curvata, and Helicotylynchus cornurus in the upper 5 cm of bentgrass (Agrostis palustris cv. Penncross) putting green turf. The effect of fenamiphos on the vertical distribution of these species also was examined.

Habituation and sensitization of the orienting response following bilateral anterior cingulotomy.

Skin conductance response (SCR) was measured in an orienting response (OR) and habituation paradigm in 10 post-cingulotomy and age-matched control subjects. While both groups habituated, the cingulotomy patients exhibited a slower habituation rate, and greater variability across trials compared to controls. Habituation abnormalities were not associated with increased sensitization, as neither extended habituation training or dishabituation differentiated the groups.

Synergistic effect between intraneoplastic methotrexate and radiation on experimental intracerebral rat gliosarcoma.

Methotrexate (MTX) alone has a limited effect against malignant brain tumors, but we previously demonstrated a beneficial synergism between MTX and radiation therapy (XRT) against RT-9 gliosarcoma. Because the beneficial effects of that study were limited by systemic toxicity and poor brain penetration of MTX, we have continued our studies using direct intracerebral MTX therapy. Male CD-Fisher rats with intracerebrally implanted RT-9 gliosarcoma and indwelling brain tumor catheters were treated with intracerebral injections of MTX, whole-brain XRT, or a combination of both.

Root Growth of Bentgrass and Annual Bluegrass as Influenced by Coinfection with Tylenchorhynchus nudus and Magnaporthe poae.

A study was conducted in growth chambers to examine main factor and interaction effects of Tylenchorhynchus nudus and Magnaporthe poae on creeping bentgrass and annual bluegrass at 24, 28, and 30 C. A 2 x 2 factorial arrangement of treatments was employed with presence and absence of T. nudus and M.