Silver Nanoparticles for the Adsorption of Manganese from Biological Samples

In this study, silver nanoparticles were prepared and used for separation and preconcentration of manganese from biological samples. The technical feasibility of silver nanoparticles for manganese removal was investigated under batch studies. The effects of different parameters such as pH of solution, time (t), amounts of PAN (E), and silver nanoparticles (N) on the adsorption of manganese by silver nanoparticle were investigated using factorial design and response surface methodology based on Box–Behnken design. Thermodynamic parameters indicate the adsorption process to be exothermic. The limit of detection of the proposed method followed by inductively coupled plasma was found to be 0.08?µg L^?1. The method was applied to determine of manganese in biological samples.     

Contrasting ability of deep and shallow rooting rice genotypes to grow through plough pans containing simulated biopores and cracks

Plant and Soil - Cracks and biopores in compacted soil such as plough pans could aid deep rooting, mitigating constraints to seasonal upland use of paddy fields for rice production. This research...     

Insecticides and soil microorganisms. III. Fate of 14C-labelled Dipterex as affected by two nodule-forming rhizobium spp. and roots of their respective leguminous host plants.

Chromatographic analysis led to the identification of monomethyl- and dimethyl-phosphates as metabolites resulting from the enzymatic degradation of 14C-labelled Dipterex in the buffer solutions and root tissues of broad bean and clover plants, as well as in the culture media of rhizobium leguminosarum and Rhizobium trifolii. The formation of 14CO2 from rhizobial cultures containing radioactive Dipterex suggests that some of the liberated methanol groups (during breakdown of Dipterex) are oxidatively degraded by the two Rhizobium spp.     

Soil and plant tests for available sulfur in wetland rice soils

Summary Soil tests, plant performance, and plant tissue analyses were used to study the availability of sulfur to wetland rice in 30 Philippine soils. The critical concentrations of available sulfur by the calcium phosphate, lithium chloride, ammonium acetate, and hydrochloric acid extractions were 9, 25, 30, and 5 mg/kg, respectively. The critical total sulfur limits were 0.11% in the shoot at maximum tillering 0.055% in the straw at maturity, and 0.065% in the grain. The critical N:S ratio was 15 in the shoot at maximum tillering, 14 in the straw at maturity, and 26 in the grain. The critical sulfate-sulfur limit was 150 mg/kg in the shoot at maximum tillering and 100 mg/kg in the straw at maturity. The critical sulfate-sulfur/total sulfur percentage ratio was 15% in the shoot at maximum tillering and the straw at maturity. Plant performance, judged by appearance and yield of dry matter, straw, and grain, was generally poorer in the sulfur deficient soils than in the other soils. Although the calcium phosphate and ammonium acetate methods gave a better correlation between plant performance and available sulfur than the others, all four methods separated sulfur-deficient soils from non-deficient ones. The hydrochloric acid method merits further study because it is simple and versatile.     

Two novel loci underlie natural differences in Caenorhabditis elegans abamectin responses

Parasitic nematodes cause a massive worldwide burden on human health along with a loss of livestock and agriculture productivity. Anthelmintics have been widely successful in treating parasitic nematodes. However, resistance is increasing, and little is known about the molecular and genetic causes of resistance for most of these drugs. The free-living roundworm Caenorhabditis elegans provides a tractable model to identify genes that underlie resistance. Unlike parasitic nematodes, C. elegans is easy to maintain in the laboratory, has a complete and well annotated genome, and has many genetic tools. Using a combination of wild isolates and a panel of recombinant inbred lines constructed from crosses of two genetically and phenotypically divergent strains, we identified three genomic regions on chromosome V that underlie natural differences in response to the macrocyclic lactone (ML) abamectin. One locus was identified previously and encodes an alpha subunit of a glutamate-gated chloride channel (glc-1). Here, we validate and narrow two novel loci using near-isogenic lines. Additionally, we generate a list of prioritized candidate genes identified in C. elegans and in the parasite Haemonchus contortus by comparison of ML resistance loci. These genes could represent previously unidentified resistance genes shared across nematode species and should be evaluated in the future. Our work highlights the advantages of using C. elegans as a model to better understand ML resistance in parasitic nematodes.     

Immunoperoxidase detection of myeloid antigens in glycolmethacrylate-embedded human bone marrow

Different methods for fixation and exposure of antigenic determinants were tested for detection of a granulocytic differentiation antigen by the monoclonal antibody L12-2, using an indirect immunoperoxidase method on semi-thin sections of undecalcified, glycolmethacrylate-embedded human bone marrow biopsies. Fixation in Bouin's solution for 3 hr gave a more intense and more homogeneous immunological staining than fixation in absolute methanol, 4% formalin, B5, or Michel's medium, and the morphological detail was excellent. Digestion by pronase or trypsin was required. Coating the glass slides with Alcian blue prevented loss of sections from the slides during the staining procedure. Bouin fixation also made possible detection of two other differentiation antigens expressed in the granulocytic series, using the monoclonal antibodies 1G10 and R1B19. Furthermore, the same technique also permitted detection of factor VIII-RAg in the megakaryocytes, as well as recognition of cells of the erythroid series by use of polyclonal rabbit antisera.     

Use of anti-idiotypic antibodies as probes for the interaction of TSH subunits with its receptor

TSH is a heterodimeric glycoprotein hormone, whose dissociated subunits are without biological activity. This has precluded the assessment of the relative contribution of each subunit to hormone action. We have raised anti-idiotypes to monoclonal antibodies specific, respectively, for the alpha and beta hTSH subunits. The anti-beta anti-idiotype inhibited 125I-hTSH binding to the beta subunit-specific monoclonal quantitatively, whereas 125I-hTSH binding to the alpha subunit-specific monoclonal was not inhibited by anti-alpha anti-idiotypes, suggesting that only the former is an "internal image" anti-idiotype. Neither of the two anti-idiotypes nor equimolar mixtures thereof inhibited 125I-bTSH binding to thyroid membranes, even though radiolabelled anti-idiotypes showed saturable binding to thyroid plasma membrane which was inhibited 41-65% by bTSH. Each anti-idiotype alone caused 9% inhibition (compared to 50% by NRIgG) of thyroid plasma membrane adenylate cyclase. Equimolar mixtures (125 micrograms/ml IgG of each anti-idiotype) induced enzyme activity equivalent to 85% of that of 250 mU/ml of TSH. The TSH-like action of the two anti-idiotypes was also reflected in their capacity to increase (450% by 250 micrograms/ml IgG compared to normal rabbit IgG) the uptake of 131I into isolated thyrocytes and to promote the organization of such cells into follicular structures. At 250 micrograms/ml, anti-beta anti-idiotype promoted the organization of small follicles and only at a concentration of 500 micrograms/ml did it enhance 131I uptake.     

A predicted three-dimensional structure for the human immunodeficiency virus binding domains of CD4 antigen

A predicted three-dimensional structure of the two N-terminal extracellular domains of human CD4 antigen, a cell surface glycoprotein, is reported. This region of CD4, particularly the first domain, has been identified as containing the binding region for the envelope gp120 protein of the human immunodeficiency virus. The model was predicted based on the sequence homology of each domain with the variable light chain of immunoglobulins. The framework beta-sheet regions were taken from the crystal coordinates of REI. For one region in the first domain of CD4 there was an ambiguity in the alignment with REI and two alternate models are presented. Loops connecting the framework were modelled from fragments selected from a database of main chain coordinates from all known protein structures. Residues identified as involved in binding gp120 have been located in several other studies within the first domain of CD4. Epitopes from eight monoclonal antibodies have been mapped onto residues in both domains. Competition of these antibodies with each other and with gp120 can be interpreted from the structural model.     

Assignment of 12 loci to rat chromosome 5: evidence that this chromosome is homologous to mouse chromosome 4 and to human chromosomes 9 and 1 (1p arm)

Twelve loci have been assigned to rat chromosome 5: aldolase B (ALDOB), atrial natriuretic factor (ANF = pronatriodilatin, PND), D4RP1, DSI1, galactosyltransferase (GGTB2), glucose transporter (GLUT1), interferon alpha 1 and related interferon alpha (INFA), interferon beta (INFB), lymphocyte-specific protein-tyrosine kinase (LCK), oncogene MOS, alpha 2U-globulin (major urinary protein, MUP), and orosomucoid (ORM, also called alpha 1-acid glycoprotein, AGP). Among these, the interferon alpha and beta genes map in the q22-23 region, which also contains a transformation suppressor gene (SAI1). The other loci reside outside this region. This study also indicated that the rat genome contains 2 LCK genes, unlike the human and murine genomes. These new assignments on rat chromosome 5 demonstrate that this chromosome is highly homologous to mouse chromosome 4 and carries synteny groups conserved on human chromosome 9 (interferon alpha and beta, galactosyltransferase, orosomucoid, and aldolase B genes) and on the short arm of human chromosome 1 (MYCL, glucose transporter, protein kinase LCK, and atrial natriuretic factor genes).