Determination of manganese in airborne particulates in a dry-cell battery factory using x-ray fluorescence technique

Feasibility of using X-ray fluorescence techniques for the determination of airborne manganese in dry-cell battery factories was investigated. Both Energy Dispersive (EDX) and Wavelength Dispersive (WDX) X-ray fluorescence techniques of analysis were used. The minimum detectable quantity of Mn by the EDX method was found to be 50 μg for membrane filter (AA type) and 100 μg for cellulose filter (pore size 2.5 μm), respectively, with a counting time of 2000 s. The most suitable exciting source was 1.11 GBq (30 mCi) Pu-238. The minimum detectable quantity of Mn by the WDX method was 10 μg, with a counting time of 100 s. Results of the X-ray fluorescence and the AA methods were found to be in good agreement. Field measurements were carried out in a dry-cell battery factory. Concentrations of airborne manganese in the factory were found to be 0.02–41.1 mg/m³.

     

Hematopoiesis and the inosine modification in transfer RNA

Human promyelocytic leukemia (HL-60) cells were used to begin to evaluate the role in hematopoiesis of inosine biosynthesis in the tRNA anticodon wobble position; a reaction involving the enzymatic insertion of performed hypoxanthine. Dimethyl sulfoxide (DMSO) and hypoxanthine were found to induce the differentiation of HL-60 cells in a synergistic manner, and the induced differentiation was independent of changes in the purine catabolic enzymes adenosine deaminase and purine nucleoside phosphorylase. The short-term exposure of HL-60 cells to DMSO plus hypoxanthine resulted in enhanced leucine incorporation, and a model is presented showing how the inosine modification reaction in tRNA may be involved. A means by which hypoxanthine insertion into tRNA may modulate the synthesis of regulatory proteins (e.g., lymphokines and cell surface receptors) is also outlined.     

A revised scheme for mass propagation of Easter Lily

Lilium longiflorum Thunb., commonly known as Easter Lily is widely propagated by vegetative means for its high ornamental value as a pot plant. Following in vitro technique, mass propagation has been achieved through direct production of bulblets from the explant as well as regeneration from callus. The chromosome analysis of the progeny derived from callus even from long term culture, did not reveal any marked variability in chromosome morphology. The stable nature of callus maintained in modified MS medium in long term culture has been confirmed. Along with rapid growth, the regenerating capacity of calli has been maintained for 3 years of culture in the above medium. Following shake culture, large number of bulblets could be obtained from such differentiated calli within 3–4 weeks. The shake culture technique of calli is ideally suited for securing stable regenerants on a mass scale in this species.Abbreviations MS Murashige & Skoog's medium - NAA -napthaleneacetic acid - IAA indole-3-acetic acid - 2,4-D 2,4-dichlorophenoxyacetic acid - BA 6-benzyladenine     

Maternal Magnesium Restriction Elevates Glucocorticoid Stress and Inflammation in the Placenta and Fetus of WNIN Rat Dams

Magnesium plays a major role in many vital functions in the body. We reported earlier that maternal magnesium restriction altered body composition, fat metabolism, and insulin resistance in WNIN rat offspring and was associated with increased glucocorticoid stress in the offspring in their later life. We hypothesize that increased glucocorticoid stress and inflammation which originate in Mg restricted rat dams is transmitted through placenta to the fetus and underlie the metabolic disturbances in the later life of the offspring. Female weanling WNIN rats received ad libitum, a control diet (MgC) or the same with 62% restriction of Mg (MgR) for 3 months, and their plasma magnesium, inflammatory cytokines, and corticosterone were determined (n = 6 per group) before mating. Following mating with control males, placentae, and fetuses were collected on gestational day 15 (GD 15) from MgC and MgR dams (eight dams from each group and three samples from each dam) and used to determine the levels of inflammatory cytokines, corticosterone, and expression of relevant genes. MgR placentae and fetuses had higher (than MgC) levels of corticosterone and proinflammatory cytokines. Expression of Hsd11b1 was increased (sixfold, p < 0.05), while that of Hsd11b2 was decreased (0.4-fold, p < 0.05) in MgR (than MgC) placenta, whereas expression of Hsd11b1was increased (3.4-fold, p < 0.05) in MgR fetus. Chronic dietary magnesium restriction in WNIN female rats increased their levels of corticosterone, leptin, and proinflammatory cytokines which appeared to be transmitted through placenta to the fetus and could thus be associated with increased stress, altered body composition, fat metabolism, and insulin resistance in the later life of the offspring.     

A survey of C-band patterns in chromosomes ofLilium (Liliaceae)

C-band patterns are described for 20Lilium spp. distributed across six sections. All species have a similar basic karyotype (n = 12) but C-bands differ markedly between them. The patterns are characterized by a dispersed scattering of thin intercalary bands as well as centric and NOR bands. Only one species,L. canadense, shows a clear equilocal pattern with intercalary C-bands occurring proximally in all of the longer chromosome arms. Comparing species, similar patterns are revealed forL. regale andL. sulphureum, forL. formosanum andL. longiflorum (all in sect.Leucolirion) and to a lesser extent forL. hansonii, L. martagon, andL. tsingtauense (sect.Martagon). The pattern forL. henryi (previously classed in sect.Sinomartagon) matches those ofL. regale andL. sulphureum quite well and its transfer to sect.Leucolirion is proposed. This is consistent with results from interspecies hybrids betweenL. henryi andL. regale (and related species) which are reportedly fertile. No other clear similarities in C-band patterns were seen across species. It seems that C-band patterns change rapidly inLilium and hence their usefulness in classification will be restricted to identifying closely related species.Dedicated to Prof.D. G. Catcheside on the 80th anniversary of his birth.     

Sediment chemistry of lakes formed by surface-mining for coal in the midwestern U.S.A.

Sediment from lakes on abandoned coal mines in the Midwestern U.S.A. was examined to determine the factors controlling chemical composition and the role the sediment plays in lake neutralization. Sediment concentrations of many cations, (especially heavy metals) are strongly correlated with sediment sulfide concentration, but poorly correlated with the pH of the overlying water. Leaching the sediment of one lake with 1 N ammonium acetate, 0.1 N HCl, and 6 N HCl revealed that cations were mostly bound in weak acid-leachable and strong acid-leachable forms. The weak acid-leachable form is likely to be metal sulfides and calcium carbonate. The sulfide-poor sediments of extremely acid lakes contained few weak acid-leachable cations. Raw mine-spoil contained large amounts of easily leached cations. There is little relationship between changes in sediment chemistry over time determined from cores of lake sediment and past lake pH. Rates of sulfide deposition were examined in sediment cores because sulfate reduction and deposition has been suggested as a major source of alkalinity in lakes influenced by acid precipitation. Although the rate of sulfate deposition in surface mine lakes is high, it alone seems to be insufficient to cause neutralization.     

Sterols in different cytological races of Urginea indica

The identification of phytosterols in roots, bulbs and leaves of diploid, triploid, tetraploid and hexaploid cytotypes of Urginea indica was carrie     

Studies on rat ovarian receptors for lutropin (luteinizing hormone). Applicability of radioimmunoassay to measure lutropin bound to receptors.

Measurement of receptor-bound unlabelled physiologically active lutropin (luteinizing hormone, LH) was possible by a modified radioimmunoassay. The conventional radioimmunoassay conducted at 4 degrees C was inadequate, whereas the modified assay performed at 37 degrees C could measure receptor-bound lutropin. The radioimmunoassay at 37 degrees C takes only 36h for completion compared with 5-7 days at 4 degreesC. The sensitivity and range of dose-response curves are, however, unaltered. The validity of the technique was established by a number of criteria.