Phagostimulants for locusts: Studies with edible oils

Six edible oils along with acetone extract of wheat bran were tested for the presence of feeding stimulants for Schistocerca gregaria and Locusta migratoria by filter paper feeding technique. The order of preference and the degree of feeding differed greatly between the two species. The order of preference of S. gregaria towards various oils was: wheat bran extract > wheat germ oil > olive oil > mustard oil > corn oil = cotton seed oil > coconut oil while in Locusta the order was: wheat germ oil > wheat bran extract = olive oil > cotton seed oil > corn oil > mustard-oil = coconut oil.The fractionation of various oils by column chromatography showed that three of the seven fractions tested, namely triglycerides, free sterols and fatty acids, and phospholipids were phagostimulatory. None of the fractions of coconut oil was found to be phagostimulatory for Locusta or Schistocerca.

---

Zusammenfassung Sechs eßbare Öle wurden zusammen mit einem Acetonextrakt von Weizenkleie mittels der Filtrierpapier-Fütterungsmethode auf ihren Gehalt an Fraßstimulatoren für Schistocerca gregaria und Locusta migrotoria geprüft. Die Reihenfolge der Annahme und das Ausmaß der Aufnahme waren bei beiden Arten sehr unterschiedlich. Die Präferenzreihenfolgen für die verschiedenen Öle waren bei S. gregaria: Weizenkleie-Extrakt > Weizenkeimlingsöl > Olivenöl > Senföl > Maisöl = Baumwollsamenöl > Kokosnußöl; bei Locusta dagegen: Weizenkeimlingsöl > Weizenkleie-Extrakt = Olivenöl > Baumwollsamenöl > Maisöl > Senföl = Kokosnußöl.Auftrennung der verschiedenen Öle durch Säulenchromatographie zeigte, daß drei von sieben geprüften Fraktionen, nämlich Triglyceride, freie sterole und Fettsäuren sowie Phospholipoide fraßanregend wirkten. Keine der Fraktionen des Kokosnußöls erwies sich für Locusta oder Schistocerca als Phagostimulans.

     

Decidual cell reaction: relative response to traumatization in uterus of rat, hamster and guinea pig

Relative decidual cell response to traumatization was studied in the uterus of immature rat, hamster and guinea pig. A single dose of progesterone (1.0 mg/animal) caused 285 +/- 41 and 459 +/- 58% uterotrophy in traumatized horn of rat and hamster respectively, while in guinea pig increasing doses of progesterone (1, 2 and 5 mg/animal), several combinations of estrogen and progesterone or alteration in treatment schedule of the two hormones as well as extending the day of traumatization failed to elicit comparable uterotrophic response. Uterus of immature hamster was found to be most responsive to traumatization and that of guinea pig the least.     

Ultrastructural morphology of ectoplacental cone trophoblasts of hamster embryos.

The invasiveness of trophoblast cells is well known, but it is not clear whether they achieve this property by being transformed to other cell types (like malignant ones) or remain benign. Trophoblasts, in culture, were studied ultrastructurally by examining the surface morphology of the cell vis-à-vis their cytoplasmic outgrowth, and the presence and/or absence of ruffling membranes, filopodia, microvilli, pinocytotic pits or bleb-like structures was observed. Results revealed formation of ruffling membranes only on the leading edge, a presence of slender filopodia and pinocytotic pits but an absence of microvilli and bleb-like structures, the characteristic features of a transformed cell. The study indicated that the trophoblast cells, in spite of being invasive, do not convert to any other cell type.     

The effects of insulin and tunicamycin on insulin receptors of cultured fibroblasts

The effect of down-regulation on the intracellular pool of insulin receptors and the role of glycosylation in recovery from down-regulation have been studied in fibroblastic cultures from the skin of non-diabetic mice. In control cultures, 55% of the total specific [¹²⁵I]insulin-binding activity was in the intracellular compartment. Insulin caused a time- and concentration-dependent decrease in the number of cell surface insulin receptors, with no significant change in total insulin receptors. This decrease in surface receptors was accompanied by an increase in the specific binding of [¹²⁵I]insulin in the intracellular compartment. Removal of insulin from down-regulated cells resulted in a time-dependent increase in the binding of [¹²⁵I]insulin to surface receptors, reaching 90% of that in controls by 12 h. The recovery of surface insulin receptors after removal of insulin was blocked by incubation of cultures with tunicamycin, but not by cycloheximide. These results indicate that down-regulation of surface insulin receptors by insulin is associated with translocation of receptors into the intracellular pool and suggest that protein glycosylation is important in insulin receptor recycling and externalization.     

Water induced dismutation of superoxide anion generates singlet molecular oxygen

Direct spectroscopic measurement of 1268 nm singlet oxygen emission from KO2 suspensions at room temperature in three non-protonic solvents--CCl4, Cl2FCCClF2, and C6F14 by the action of water is reported. The results clearly show that the singlet oxygen generation is due to a water induced reaction, and suggest that one role of the enzyme superoxide dismutase may be the protection of biological structures, for example, lipid membranes, from degradation by singlet oxygen.     

Iron-magnesium antagonism in growth and metabolism of radish

A study was conducted on the interaction effect of Fe–Mg on growth, metabolism and nutrient uptake in radish (Raphanus sativus L. cv. All Season) plants grown in sand culture. Dry matter yields were maximum at normal Fe-normal Mg and excess Fe-excess Mg treatments where the Fe/Mg ratio in the rooting medium was 0.12; below or above this ratio the yields were continuously lowered. On the basis of the effects of various Fe–Mg combinations on growth, visible effects, concentration of chlorophyll, the activities of catalase, peroxidase and ribonuclease and the tissue concentration of Fe, Mg and Mn, it is inferred here in this study that Fe and Mg are mutually antagonistic in the growth and metabolism of radish.     

Dynamics of Physical Interaction between HIV-1 Nef and ASK1: Identifying the Interacting Motif(S)

FasL mediated preferential apoptosis of bystander CTLs while protection of infected CD4⁺T cells remains one of the hallmarks of immune evasion during HIV infection. The property of infected host cells to evade cell-autonomous apoptosis emanates from ability of HIV-1Nef -protein to physically interact with ASK-1 and thereby inhibit its enzymatic activity. The specific domains of HIV-1Nef through which it may interact with ASK1 and thereby impair the ASK1 activity remain unidentified so far and represent a major challenge towards developing clear understanding about the dynamics of this interaction. Using mammalian two hybrid screen in association with site directed mutagenesis and competitive inhibitor peptides, we identified constituent minimal essential domain (152 DEVGEANN 159) through which HIV-1Nef interacts with ASK1 and inhibits its function. Furthermore our study also unravels a novel alternate mechanism underlying HIV-1 Nef mediated ASK1 functional modulation, wherein by potentiating the inhibitory ser⁹⁶⁷ phosphorylation of ASK1, HIV-1Nef negatively modulated ASK1function.