Technical note: a primatrail or an inexpensive cage expansion for group housing small primates.

An inexpensive method for converting standard laboratory cages into colony units for housing small primate species is described.     

Met-enkephalyl-Arg6-Phe7 immunoreactivity in a human neuroblastoma cell line: effect of dibutyryl 3':5'-cyclic AMP and reserpine

The carboxy terminal part of the proenkephalin A sequence is the 31 amino acid peptide B, which has as its final seven amino acids the sequence of the opioid peptide Met-enkephalyl-Arg6-Phe7. Using a radioimmunoassay which recognises both these peptides we have investigated the relative amounts of peptide B and Met-enkephalyl-Arg6-Phe7 in a human neuroblastoma cell line. We show that these cells contain peptide B-like immunoreactivity but not its heptapeptide fragment. This may be due to lack of proteolytic activity cleaving Met-enkephalyl-Arg6-Phe7 from its precursor, peptide B. On treatment with dibutyryl cyclic AMP the level of immunoreactivity approximately doubles, due to increased amounts of peptide B-like immunoreactivity. Treatment with reserpine, which increases conversion of peptide B to the heptapeptide in bovine chromaffin cells in culture does not stimulate the accumulation of Met-enkephalyl-Arg6-Phe7 in the human neuroblastoma cells. The results are discussed with respect to peptide processing.     

Nucleotide sequence of the Acinetobacter calcoaceticus trpGDC gene cluster

A plasmid library of Acinetobacter calcoaceticus HindIII fragments was constructed, and clones that complemented an Escherichia coli pabA mutant were selected. Plasmids containing a 3.9-kb fragment of A. calcoaceticus DNA that also complemented E. coli trpD and trpC-(trpF+) mutants were obtained. We infer that complementation of E. coli pabA mutants was the result of the expression of the amphibolic anthranilate- synthase/p-aminobenzoate-synthase glutamine-amidotransferase gene and that the plasmid insert carried the entire trpGDC gene cluster. In E. coli minicells, the plasmid insert directed the synthesis of polypeptides of 44,000, 33,000, and 20,000 daltons, molecular masses that are consistent with the reported molecular masses of phosphoribosylanthranilate transferase, indoleglycerol-phosphate synthase, and anthranilate-synthase component II, respectively. A 3,105- bp nucleotide sequence was determined. Comparison of the A. calcoaceticus trpGDC sequences with other known trp gene sequences has allowed insight into (1) the evolution of the amphibolic trpG gene, (2) varied strategies for coordinate expression of trp genes, and (3) mechanisms of gene fusions in the trp operon.      

Differential precipitation and zinc chelate chromatography purification of biologically active HTLV-I Tax1 expressed in E. coli

A protocol which involves sequential ammonium sulfate precipitation and zinc chelate chromatography to purify the HTLV-I Tax1 protein expressed in E. coli is described. The final Tax1 product is greater than 90% pure and the yield is approximately 1 mg per liter of liquid culture. The purified Tax1 protein is biologically active in indirect in vitro DNA binding assays and cellular NF-kB induction experiments.     

Substance P-Induced Release of Prostaglandins from Astrocytes: Regional Specialisation and Correlation with Phosphoinositol Metabolism

Addition of substance P (SP) to astrocytes cultured from rat neonatal spinal cord evoked a time- and concentration-dependent increase in the accumulation of phosphoinositol and the release of prostaglandin (PG) D2 and PGE2. Both basal and stimulated releases were reduced to similar levels by indomethacin. In contrast, astrocytes cultured from cerebral cortex and cerebellum showed no SP-stimulated increase in phosphoinositol accumulation or release of PGs. Release of PGD2 and PGE2 was, however, stimulated by the calcium ionophore A23187, and both phosphoinositol accumulation and PG release were stimulated from cortical astrocytes incubated in the presence of serum. The results from this study suggest that SP-stimulated phosphoinositol accumulation and release of PGs from cultured rat neonatal astrocytes are regionally specialised in favour of cells derived from spinal cord.     

Soluble HTLV-I Tax1 protein stimulates proliferation of human peripheral blood lymphocytes.

Human T-cell leukemia virus type I (HTLV-I) is associated with two human diseases, adult T-cell leukemia (ATL) and tropical spastic paraparesis/HTLV-I associated myelopathy (TSP/HAM). Lymphocytes from patients with ATL or TSP/HAM display abnormal proliferation properties in culture. Here we report that purified, soluble Tax1 protein can be taken up by, and stimulate proliferation of, uninfected human peripheral blood lymphocytes (PBLs) that have been stimulated with phytohemagglutinin (PHA). Tax1 was 40 to 70% as active as interleukin-2 (IL-2) in stimulating proliferation of PBLs. Heat inactivation, chloroform extraction, and immunoprecipitation with antisera specific for Tax1 each abolished the ability of the protein to stimulate lymphocyte proliferation. Tax1 failed to stimulate PBL proliferation in the absence of PHA. After an initial round of cell division, Tax1-treated PBLs exhibited prolonged sensitivity to IL-2-induced proliferation. These results indicate that Tax1 can stimulate lymphocyte proliferation in culture and imply that extracellular Tax1 may be involved in the spontaneous proliferation of TSP/HAM lymphocytes and the IL-2-dependent proliferation of ATL lymphocytes.     

Host plant choice and location by larvae of the wheat bulb fly (Delia coarctata)

Wheat bulb fly (Delia coarctata Fallen, Diptera: Anthomyiidae) is an important pest of winter wheat in the eastern half of the UK, and in northern and eastern Europe. The larvae must find a host plant and invade a tiller soon after hatching in late January. Chemical controls are costly and weather conditions may reduce their efficacy or prevent their application. Post‐emergence control relies on organophosphate insecticides, which may soon be withdrawn due to concerns about their negative health and environmental effects. Winter wheat (Triticum aestivum L.) is the preferred cereal host, but other winter cereals and related grasses may also be attacked, while oats (Avena spp.) are shunned. In choice test bioassays, neonate larvae chose couch grass (Elytrigia repens (L.) Nevski syn. Elymus repens (L.) Gould, Agropyearon repens (L.) Beauv.) seedlings and exudates over wheat seedlings and exudates, and exhibited geotaxis and negative phototaxis. Analysis of larval trails in choice test bioassays of seedling exudates showed that couch exudates are more attractive than wheat exudates, and that wheat exudates are more arrestant than couch exudates. This suggests that infochemicals isolated from couch, wheat, and oats could be used in wheat bulb fly control; possible delivery mechanisms are discussed. These findings, previous research, and a comparison of the phenologies and geographical distributions of D. coarctata and its hosts suggest that E. repens is the natural host of D. coarctata.     

Preincubation with Substance P Induces Substance P-Stimulated Phosphatidylinositol Turnover in Cultured Cerebellar Astrocytes

In this study we have investigated the effects of preincubation of cultured astrocytes with substance P (SP) on subsequent 125I-Bolton-Hunter conjugated SP (125I-BHSP) receptor binding, and SP-stimulated phosphatidyl-inositol (PI) accumulation. Spinal cord astrocytes preincubated for up to 96 h with SP (0.001-1,000 nM) suffered a dose-dependent decrease in both subsequent 125I-BHSP and SP-stimulated PI turnover. In contrast, preincubation of cerebellar astrocytes with SP resulted in an increase in SP-stimulated PI turnover, with no change in 125I-BHSP receptor binding. SP-induced PI turnover in cerebellar astrocytes was maximal after 72 h of preincubation with 0.1 nM SP. These data suggest that increased coupling between receptor and second messenger occurs in response to chronic exposure to SP.     

Design,synthesis, docking,Hirshfeld surface analysis and DFT calculations of 2-methylxanthen-9-with the FtsZ protein from Staphylococcus aureus

It is of interest to document the design, synthesis, docking, Hirshfeld surface analysis and DFT calculations of 2-methylxanthen-9-with the FtsZ protein (PDB ID: 3VOB) from Staphylococcus aureus for antimicrobial applications. We report the quantitative structure function data in this context.