l-Methionine-dl-sulfoximine resistant Het+ Nif+ and Het− Nif− strains of Nostoc muscorum assimilating methylamine as ammonium nitrogen source

Abstract The Het⁺ Nif⁺ and Het⁻ Nif⁻ strains of Nostoc muscorum sensitive to growth inhibition by methylamine (MA), overcame the MA inhibition as a result of their mutation to l -methionine- dl -sulfoximide (MSX)-resistant phenotype, which enabled them to assimilate MA like an ammonium nitrogen source. The MSX-resistant Het⁺ Nif⁺ strain synthesized the inhibitor-resistant transferase-defective glutamine synthetase (GS), which unlike parental GS underwent MA-dependent in vivo activation. These results suggest the involvement of GS enzyme in control of MA assimilation in cyanobacteria.     

The oxidation of endogenous ascorbic acid during histamine secretion by rat peritoneal mast cells

Endogenous ascorbic acid is oxidized to the free radical species by rat mast cells during histamine secretion. This antioxidant may function as a radical scavenger of Superoxide and other membrane-damaging radicals known to be liberated by this process. The high levels of ascorbic acid in mast cells may, therefore, function to protect the cell membrane from oxidative damage and thereby promote cell survival after an extensive secretory response.     

Temperature dependence of the microwave properties of aqueous solutions of ethylene glycol between +15 degrees C and -70 degrees C.

The values of the dielectric constant and of the loss tangent for samples of 0 m (distilled H₂O), 1 m, 2 m, 3 m, 4 m, 5 m, 10 m, and 100% ethylene glycol were determined over the temperature range of +15 °C to ?70 °C. An operating frequency of 1.40 GHz to 1.55 GHz was used, allowing the results to be applied directly to both 0.915 GHz and 2.450 GHz studies. Strong temperature and concentration dependencies were found; low concentration solutions tended to behave similarly to water, while higher concentration solutions were more independent. Peak values and discontinuities occurred at different temperatures, depending on concentration. Five molar ethylene glycol was indicated as a near optimum concentration based on toxicity, cryoprotection, and microwave power absorption considerations. A study of blends of cryoprotectants is suggested.     

Human peripheral lymphocyte transformation induced by the Robina lectin.

The effect of transfer factor was studied in 32 children recuperating from protein-calorie malnutrition. Half of the children were given transfer factor; the other half were given saline in a randomized, double-blind trial. Although unexpectedly low mortality in both groups precluded the adequate evaluation of transfer factor in preventing death during the nutritional recovery period, there was no difference between treated and control patients on a variety of indices of rehabilitation. In addition, transfer factor had no demonstrable effect on the evolution of delayed cutaneous hypersensitivity as both groups of patients recovered from the anergy associated with protein-calorie malnutrition.     

Comparative C19-radiosteroid metabolism by MA 160 and HeLa cell lines

Summary Since the designation of the human MA 160 line as prostatic epithelial cells has been questioned and the possibility of HeLa cross contamination raised, this comparative study of C₁₉-radiosteroid transformation in MA 160 and HeLa monolayer cultures was done to determine whether these cells possess the distinguishing features of reductive and oxidative androgen metabolism expected in male and female genital organs, respectively. We compared the radiometabolite patterns produced by incubating [¹⁴C]testosterone (300nM) and [³H]testosterone (3nm) and 5α-dihydrotestosterone (17β-hydroxy-5α-androstan-3-one) with cultures of prostatic MA 160 and HeLa Parent, TCRC-1, TCRC-2 and ATC 229 cells. C₁₉-Radiosteroid metabolite patterns from MA 160 cell incubations also were compared with patterns generated by MA 196 fibroblasts from abdomnal skin of the same donor. MA 160 cells metabolized radiotestosterone predominantly to 5α-dihydrotestosterone, 5α-androstane-3α,17β-diol and 5α-androstane-3β,17β-diol. The diol epimers were the principal metabolites of 5α-dihydrotestosterone radiosubstrate. In contrast, radiotestosterone metabolism by MA 196 and HeLa Parent, TCRC-1 and TCRC-2 cells was overwhelmingly to the 17-oxosteroids 4-androstene-3,17-dione and androsterone. Another pathway was operative in HeLa 229 and, to a minor extent, in TCRC-1, which converted radiotestosterone to 4-androstene-3α,17β-diol and 5α-androstane-3α,17β-dol, with little formation of 5α-dihydrotestosterone. MA 160 cells thus metabolize radiotestosterone preponderantly to 5α-reduced 17β-hydroxysteroids as expected for prostatic epithelial cells, whereas HeLa cells show heterogeneity in metabolizing the labeled hormone by the alternative 17-oxosteroid and Δ⁴ pathways. This work was supported by Public Health Service Research Grants CA 13417 and CA 12924 from the National Cancer Institute, AM 11011 from the National Institute of Arthritis, Metabolism and Digestive Diseases, and by appropriations of the Commonwealth of Massachusetts, Item No. 4532-9003-01.     

Orientation of flight for physically disturbed spotted lanternflies,Lycorma delicatula, (Hemiptera,Fulgoridae)

The spotted lanternfly, Lycorma delicatula, (Hemiptera, Fulgoridae) is an invasive pest to Korea and the United States, originating from China or Southeast Asia. Immature L. delicatula feed on a wide range of plants, but the adults are more host-selective, often preferring the tree of heaven, Ailanthus altissima. We performed field studies to evaluate adult movement in relation to A. altissima after disturbance. The Ailanthus trees were in a mixed suburban forested situated at the southern border of an open grassy field. Female adult lanternflies were manually disturbed from feeding on the trunks of large A. altissima trees. In the first experiment, insects were disturbed directly from the tree using a ballpoint pen to simulate a predatory attack. These insects usually flew initially southward away from the tree line toward a sunlit field, but turned northward back toward the tree line. In the second experiment, to simulate an initially successful predatory attack, they were manually taken from trees, and allowed to escape. The females immediately opened their wings in an apparent aposematic display. They then either immediately flew toward the sunlit open field, or remained with their wings splayed open for a prolonged period.