bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparison of sterols of pollens, honeybee workers, and prepupae from field sites
Authors: Svoboda James A. , Herbert Elton W. , Lusby William R. , Thompson Malcolm J. 
Published: February 2005

AbstractSterols from pollen collected by foraging honeybees, Apis mellifera L, at seven field sites were compared with the sterols of foraging adults and/or prepupae collected from colonies at each site. Invariably, the composition of prepupal sterols was comparable to that found in previous cage studies using chemically defined diets containing various dietary sterols: 24‐methyl‐enecholesterol was the major sterol; sitosterol and isofucosterol were present in lesser, but significant amounts; and a trace amount of cholesterol was identified in each sample. This occurred even though some of the pollen sterols contained little 24‐methylenecholesterol, sitosterol, or isofucosterol and a preponderance of certain other sterols, such as δ7‐stigmasten‐3β‐ol and δ7,24(28)‐campestadien‐3β‐ol in goldenrod and corn pollens, respectively. Thus the selective transfer and utilization of sterols in honeybees that have been demonstrated in cage studies with artificial diets were also shown to occur under field conditions.
The effects of tunicamycin and 20‐hydroxyecdysone on the cell surface properties of two insect cell lines
Authors: Jang Eric B. , Marks Edwin P. 
Published: February 2005

AbstractThe radiolabeled lectins, concanavalin A* and wheat germ agglutinin, were used to study surface properties of two insect cell lines. We also looked at the effects of tunicamycin and 20‐hydroxyecdysone on the binding of these lectins to one of the cell lines. Both UMBGE‐2 and CH‐MRRL cells bound both lectins, specifically. The CH‐MRRL cells showed an overall higher binding for the lectins than the UMBGE‐2 cells. This difference may account for some of the striking morphological difference seen between these cells. Tunicamycin and 20‐hydroxyecdysone decreased the binding of both [125I]‐Con A and [125I]‐WGA to CH‐MRRL cells. These results suggest that cell surface glycoproteins play a role in the modification of cellular morphology and in other hormone‐mediated physiological functions.
The action of iontophoretically applied L‐glutamate on an insect visceral muscle
Authors: Dunbar Stuart J. , Piek Tom 
Published: February 2005

Abstract1) lontophoretic application of L‐glutamate was employed to study the distribution of glutamate receptors in the superior longitudinal (SL) muscles of the locust (Locusta migratoria) hindgut, in which spontaneous activity was inhibited using normal saline containing 5 mM MgCl2. 2) Junctional glutamate potentials with a rise time of 50–100 ms (peak) and a decay time of 250–400 ms were recorded at localized sites using ejection pulses in the range 5–10 nC. Most active sites were found in interfiber clefts and were spaced at about 250–300 μm intervals. 3) Desensitization of glutamate receptors occurred using ejection frequencies > 0.2 Hz. Desensitization could be irreversibly blocked using the lectin concanavalin A. 4) Depolarizing (D‐) and biphasic depolarizing/hyperpofarizing (DH ‐) extrajunctional glutamate potentials were observed using ejection pulses > 15 nC. 5) δ‐Philanthotoxin (δ‐PTX) at concentrations > 0.3 Uml−1 inhibited junctional glutamate potentials in a dose‐dependent manner, 50% inhibition was achieved using 0.45 Uml−1 δ‐PTX. 6) Subthreshold concentrations of proctolin (up to 5 × 10−10M) had no visible effect on glutamate potentials, suggesting that proctolin possibly does not act by modulating glutamate activity. 7) It is proposed that glutamate plays a transmitter role in SL muscles, while the role of proctolin is still unclear.
Treatment of larvae with repeated doses of precocene II induces precocious metamorphic changes in Spodoptera mauritia (Lepidoptera: Noctuidae)
Authors: Mathai Sam , Nair V. S. K. 
Published: February 2005

AbstractIn Spodoptera mauritia repeated daily treatments of larvae with 40 μg of precocene II throughout the fifth and sixth instar larval period had no effect on the larval‐larval period but prolonged larval‐pupal ecdysis. The resulting pupae showed precocious adult differentiation of mouth parts, wings, eyes, legs, and fat body.
Some pharmacological properties of neuromuscular transmission in the oviduct of the locust, Locusta migratoria
Authors: Lange Angela B. , Orchard Ian 
Published: February 2005

AbstractThe effects of various pharmacological agents on neurally evoked contractions of the visceral muscles of the oviduct of Locusta migratoria have been examined. The pentapeptide, proctolin, at low concentrations (10−11 M−10−10 M), induced an increase in the amplitude of neurally evoked contractions and basal tonus, and induced the appearance and increased the frequency of myogenic contractions. Glutamate, at 10−4 M, produced a small transient contraction which in some preparations was accompanied by a reduction in amplitude of neurally evoked contractions. Octopamine, at 10−6 M, reduced the amplitude of neurally evoked contractions and also resulted in a relaxation of the muscles. The octopaminergic effects were inhibited by the α‐aminergic antagonist phentolamine. Neurally evoked contractions were unaffected by dopamine, 5‐HT or the acetylcholine receptor antagonists atropine and hexamethonium. Acetylcholine increased the amplitude of neurally evoked contractions, but only at the high concentration of 10−3 M.The possible role of proctolin and glutamate as excitatory neuro‐transmitters and the inhibitory action of octopamine is discussed.
Inhibitory probes of mitochondrial ATPase and the action of DDT
Authors: Dary C. C. , Cutkomp L. K. 
Published: February 2005

AbstractChemical inhibitors were used as probes of mitochondrial ATPase to determine the site of action of DDT on oligomycin‐sensitive mitochondrial ATPase (OS‐ATPase) using whole mitochondria isolated from red coxal muscle of the American cockroach. Several plotting procedures were employed to delineate the form of inhibition. Relative potency and joint action were used to detect similar action, synergism, and antagonism between DDT and the inhibitory probes DCCD, Nbf‐CI, and oligomycin. DDT demonstrated not (strictly) competitive kinetics and may be acting as an uncompetitive inhibitor. DDT and DCCD produced similar additive action. At limiting concentrations of DCCD, inhibition was reduced in the presence of DDT. Effects shown by oligomycin were not altered by DDT. DDT enhanced the effects of Nbf‐CI. These interactions, together with the demonstration of not (strictly) competitive kinetics, indicate that DDT may be acting on the membrane sector as an allosteric modifier.
Comparison of structurally analogous allatotoxins on the molting and morphogenesis of Rhodnius prolixus, and the reversal of ecdysial stasis by ecdysone
Authors: Garcia Eloi S. , de Azambuja Patricia , Bowers William S. 
Published: February 2005

AbstractThe allatotoxic effect of 3‐ethoxy‐4‐methoxy‐6‐iso‐pentenylphenol on nymphal molting and metamorphosis of Rhodnius prolixus was examined. Continuous contact treatment with IPP induced the formation of precocious adults and retarded molting or initiated a permanent ecdysial stasis. Insects treated with 7‐ethoxy‐6‐methoxy‐2,2‐dimethylchrornene were similarly affected. Ecdysone given orally counteracted the ecdysial stasis and also reduced the duration of the molting delay caused by IPP.
Comparative studies on pharmacokinetics and metabolism of the anti‐juvenile hormone precocene II
Authors: Haunerland Norbert H. , Bowers William S. 
Published: February 2005

AbstractThe cuticular penetration and pharmacokinetics of the anti‐juvenile hormone precocene II were determined in a sensitive species (Oncopeltus fasciatus) and an insensitive species (Heliothis zea). Precocene was sequestered by the fat body and slowly metabolized in Oncopeltus, but rapidly metabolized and excreted in Heliothis. Studies in vitro using inhibitors for cytochrome P‐450 and for cyt P‐450‐NADPH‐reductase, confirmed the anticipated detoxification of precocene by a mixed‐function oxidase via the 3,4‐epoxide. Use of the inhibitors in vivo had no influence on the metabolism of precocene.
Effect of metamorphosis on the major hemolymph proteins of the silkworm
Authors: Seong Su Ii , Park Kwang E. , Nagata Masao , Yoshitake Narumi 
Published: February 2005

AbstractDuring the metamorphosis of the silkworm, Bombyx mori, three major hemolymph proteins (MHPs) (molecular weights 17,000, 25,000, 27,000) were detected and found to be distributed in the hemolymph and in the tissues of several organs, such as the fat body, midgut, ovary, testis, and even eggs. The MHPs in eggs gradually decreased and disappeared during embryogenesis. The formation, distribution, and utilization of MHPs in tissues other than the gonad, however, were not affected by sex.Radioisotope experiments in vivo revealed that the MHPs were synthesized at an early period of the fifth larval instar. The synthesis of at least two of them occurred in the fat body. MHPs in the hemolymph entered the tissues at the onset of the larval‐pupal transformation. On the basis of their appearance, distribution, and depletion, the MHPs may be classified as reserve proteins which are synthesized in the larval stage and utilized later in the developmental stages.
The disappearance of injected prostaglandins from the circulation of adult female australian field crickets, Teleogryllus commodus
Authors: Stanley‐Samuelson David W. , Loher Werner 
Published: February 2005

AbstractDuring the first 2 h following injection of 0.02 μCi of [14C]‐prostaglandin E2 into the abdomen of adult virgin female crickets, T. commodus, the concentration of radioactivity in the circulating hemolymph decreases. The reduction is associated with the increase in radioactivity in the Malpighian tubule/hindgut complex, ovaries, fat body, and, to a much smaller extent, ventral nerve cord and flight muscles. The finding that most, but not all, of the radioactivity in the hindgut is located in the contents of the lumen suggests that a high proportion of prostaglandins circulating in the hemolymph of T. commodus is eliminated by the usual excretory pathway. We suggest that the differential uptake of label from the circulating hemolymph by various tissues may be related to possible physiological functions that remain to be discovered.
Biosynthesis and distribution of ecdysone and 20‐OH‐ecdysone in Aedes aegypti
Authors: Borovsky Dov , Whisenton Lavern R. , Thomas Billy R. , Fuchs Morton S. 
Published: February 2005

AbstractThe distribution and biosynthesis of ecdysone and 20‐hydroxyecdysone (20‐OH‐ecdysone) was followed in sugar‐ and blood‐fed female Aedes aegypti. In both sugar‐ and early blood‐fed animals most of the ecdysteroid determined by radioimmunoassay was found outside the ovary. Twenty‐four to 40 h after blood feeding, however, ecdysteroid was distributed between ovary and carcass in the ratio of 1:1.5. Ecdysteroid titer reached a plateau between 18 to 40 h after the blood meal and decreased thereafter. Analysis of the ecdysteroid titer using thin layer chromatography (TLC) and high performance liquid chromatography (HPLC) revealed that both 20‐OH‐ecdysone and ecdysone were synthesized after the blood meal. The ratio of 20‐OH‐ecdysone to ecdysone remained essentially constant and fluctuated in parallel throughout egg development. Chromatography of the early ecdysteroid peak (8 h after feeding) using TLC and HPLC indicated that although it cross‐reacted with ecdysteroid antibodies, it did not have the same elution times as ecdysone and 20‐OH‐ecdysone and is, therefore, probably a precursor of these ecdysteroids. Injections of egg development neurosecretory hormone (EDNH) preparation purified to near homogeneity, into ligated abdomens, induced ecdysteroid synthesis only if the abdomens were first treated with methoprene (12.5 pg). Methoprene at this concentration did not stimulate ecdysteroid synthesis in these abdomens. When blood‐fed females were treated with [4‐14C] cholesterol and analyzed using TLC and HPLC procedures, both [14C]labeled ecdysone and [14C]labeled 20‐OH‐ecdysone were synthesized in the ratio of 1:1.5. This report is the first to show that both ecdysone and 20‐OH‐ecdysone are synthesized in vivo in female A. aegypti.
Linoleic acid biosynthesis in the pea aphid, Acyrthosiphon pisum (Harris)
Authors: De Renobales Mertxe , Ryan Robert O. , Heisler Charles R. , McLean Donald L. , Blomquist Gary J. 
Published: February 2005

AbstractThe pea aphid Acyrthosiphon pisum (Harris) incorporated [1‐14C]acetate into a phospholipid dienoic fatty acid in a time‐dependent manner. In 2‐h incubations, the incorporation of radioactivity into the 18:2 fraction was minimal, whereas after 45 h 18:2 was the major fatty acid labeled. Ozonolysis of the isolated dienoic fatty acid methyl ester followed by radio‐gas‐liquid chromatography showed that radioactivity was associated with fragments containing carbons 1–9 and 13–18. These data established the location of the double bonds in the 9,12 positions and indicated that the entire molecule was labeled from [1‐14C]acetate. Tetracycline‐treated aphids synthesized linoleic acid in the same proportions as untreated controls. Scanning electron microscopy showed that over 50% of the treated insects had greatly reduced numbers of intracellular symbiotes or lacked them or most of the existing symbiotes had an abnormal appearance. Therefore, we conclude that intracellular symbiotes are not involved in the biosynthesis of linoleic acid in the pea aphid.
Absence of female‐specific protein in the hemolymph of stable fly Stomoxys calcitrans (L.) (Diptera: Muscidae)
Authors: Houseman Jon G. , Morrison P. E. 
Published: February 2005

AbstractChanges, during the reproductive cycle, in fat body, hemolymph, and ovarian proteins of the stable fly Stomoxys calcitrans were characterized quantitatively and qualitatively using sodium dodecyl sulphate‐polyacrylamide gel electrophoresis (SDS‐PAGE). Protein content of all three tissues increased after blood feeding. Fat body protein increased first, followed by hemolymph and ovarian proteins. SDS‐PAGE failed to identify vitellogenin in both female hemolymph and fat body samples. No single protein or group of proteins predominated at any stage of the reproductive cycle. Comparisons between male and female stable fly hemolymph and fat body proteins failed to detect female‐specific proteins. Female‐specific proteins, however, were detected in the hemolymph of four other species of Diptera.
The effect of L‐canavanine and L‐canaline on the hemolymph amino acid composition of the tobacco hornworm, Manduca sexta (L.) (Sphingidae)
Authors: Lenz Cynthia , Dahlman D. L. , Rosenthal G. A. 
Published: February 2005

AbstractTobacco hornworm larvae, Manduca sexta (L.) (Sphingidae), were administered L‐canaline either by parenteral injection or by dietary consumption. The overt toxicity and the alteration of hemolymph amino acids caused by these nonprotein amino acids were evaluated. The LD50 value for parenterally administered canavanine and canaline is 1.0 and 2.5 mg/g fresh body weight, respectively. A dietary concentration of 5.2 mM for canavanine and over 20 mM for canaline represent the respective LC50 values. A large percentage of the larvae reared on diets supplemented with additional arginine, ornithine, or 2,4‐diaminobutyric acid in addition to canavanine or canaline were unable to complete larval‐pupal ecdysis. These toxic effects were associated with a decreased glutamic acid hemolymph titer and dramatically elevated ornithine. On the other hand, larvae administered canavanine or canaline alone, either by dietary consumption or parenteral injection, experienced less drastic developmental aberrations. These symptoms were in some cases correlated with increased ornithine and glutamic acid titers. Evidence is presented that even a canavanine‐ and canaline‐sensitive insect such as M. sexta has a marked ability to eliminate these protective allelochemicals.
Effects of the tumor promoter 12‐0‐tetradecanoyl‐phorbol‐13‐acetate on the wasp, Bracon hebetor
Authors: Best R. G. , Grosch D. S. 
Published: February 2005

AbstractA single oral dose of the tumor promoter, 12‐0‐tetradecanoyl‐phorbol‐13‐acetate (TPA), caused a rapid necrosis of the ovarioles, aberrations in the developmental sequence of oocytes, and a concomitant dose‐dependent decline in egg production in the wasp, Bracon hebetor. TPA and its metabolities were found to have a biological half life of 26.7 h, with a peak concentration in the ovarioles in 3 h. Damage to ovariole tissue was persistent despite the relatively short half life. Other tissues in the wasp were largely unaffected, although TPA induced lethargy that persisted until death. There was no shortening of life span. Inhibition of intercellular transport and metabolic cooperation may account for decreased fecundity and fertility, but interaction with a phorbol ester receptor is more likely to account for developmental changes and central nervous system poisoning.
Pupariation in flies: A tool for monitoring effects of drugs, venoms, and other neurotoxic compounds
Authors: Zdarek Jan , Fraenkel Gottfried 
Published: February 2005

AbstractA complex Sarcophaga bullata pupariation assay was used to evaluate the neurotropic effects of several drugs, venoms, and insecticides. The assay consists of tests for (1) immediate effects on the intact larva, (2) effects on ligated (ie, isolated from the central nervous system) larval abdomens, (3) morphogenetic effects on the puparium, and (4) effects on stereotyped pupariation behavior. The latter are monitored barographically by recording changes in hemocoelic pressure. Of 62 compounds screened, 18 showed morphogenetic activity at a threshold dose of 5 μg or less, 11 at a dose of 50 μg, four at a dose of 100 μg, and 29 showed no morphogenetic activity. From a comparison of the putative pharmacological actions of the tested compounds with their morphogenetic effects, certain generalizations can be made: Agents that paralyze neuromuscular systems at the peripheral level (eg, tetrodotoxin), or suppress or modify basic motor patterns centrally (eg, veratrine sulphate), cause retention of larval morphological characters in the puparium. Compounds that stimulate convulsive contractions of segmental musculature (mostly cholinergic drugs like eserine sulphate, nicotine, organophosphate insecticides) cause retention of larval segmentation on longitudinally contracted puparia. Five compounds (venom of the scorpion, Leirus quinquestriatus, pyrethrins, protoveratrine A, and kainic and quisqualic acids) stimulate musculature of the denervated abdomen. Barographic monitoring of changes in pupariation behavior appears to be a most sensitive and informative test. It reveals great differences in the ways in which compounds producing seemingly identical morphogenetic effects affect and modify behavior, thus making pharmacological classification more accurate.
Effect of heat shock on protein synthesis in Locusta migratoria epidermis
Authors: Baldaia L. , Maisonhaute C. , Porcheron P. , Best‐Belpomme M. 
Published: February 2005

AbstractHeat shock induced by an increase in temperature from 30°C to 47°C led to changes in protein synthesis in wing pads of the fifth larval instar of Locusta migratoria. Synthesis of heat shock proteins in the molecular weight range of 85,000, 70,000 and 18,000–22,000 was first detected at a threshold temperature of 45°C and was found to be highest at 47°C. A marked decline in the synthesis of many other proteins was also evident at 47°C. Recovery of general protein synthesis was observed when wing pads were shifted back to 30°C after a 2‐h heat shock at 47°C. Heat shock protein patterns in Locusta and Drosophila were compared.
N‐terminal amino acid sequence analysis of dihydrofolate reductase from methotrexate‐resistant mosquito cells
Authors: Johnston Anne M. , Fallon Ann Marie 
Published: February 2005

AbstractMethotrexate‐resistant mosquito (Aedes albopictus) cell mutants were used as starting material for the purification of dihydrofolate reductase. Initial fractionation of a crude cell lysate by ammonium sulfate precipitation showed an enrichment of enzyme activity in the 60‐100% pellet. Purification of this ammonium sulfate fraction on a Sephadex G‐75 column prior to affinity chromatography was required for maximal yield of purified protein. A protein with dihydrofolate reductase activity and an Mr of 24,000 was eluted from a methotrexate‐agarose column with 0.5 M Tris‐HCl, pH 8.5, containing 2 mM folic acid. A 21‐fold increase in specific activity relative to that in the crude cell lysate was obtained, and amino acid sequence analysis confirmed that dihydrofolate reductase from the affinity column migrated as an electrophoretically pure band on SDS polyacrylamide gels. The initial 20 amino acid residues of the mosquito dihydrofolate reductase were identified by microsequencing and compared to those of murine, human, and bacterial dihydrofolate reductase molecules.
Pharmacology of octopamine‐, dopamine‐, and 5‐hydroxytryptamine‐stimulated cyclic amp accumulation in the corpus cardiacum of the american cockroach, Periplaneta americana L
Authors: Gole John W. D. , Orr Gregory L. , Downer Roger G. H. 
Published: February 2005

AbstractA variety of potential receptor agonists were incubated with isolated corpora cardiaca from the American cockroach Periplaneta americana to determine their effects on cyclic AMP production in this gland. Octopamine, dopamine, and 5‐hydroxytryptamine elevated cyclic AMP levels in a dose‐dependent manner with estimated Ka values of 15.8, 1.7, and 1.1 m̈M, respectively, and their stimulation was found to be additive. Several vertebrate receptor antagonists were tested against the three amines and a preliminary pharmacological profile developed.
Hormonal control of ovarian development in the silkworm, Bombyx mori
Authors: Tsuchida Kozo , Nagata Masao , Suzuki Akinori 
Published: February 2005

AbstractHormonal control of ovarian development was examined in Bombyx mori. The weight of the ovary increased suddenly by 3 days after pupal ecdysis, and vitellogenin could be immunologically detected in the ovary at that time. The ecdysteroid titers during pupal‐adult development, quantified by radioimmunoassay, increased from day 0 to day 2. Ovarian development was arrested for a long period in brainless pupae and isolated pupal abdomens. Injection of 20‐hydroxyecdysone into such preparations stimulated development of the ovaries, and vitellogenin could be detected in ovaries 2 days after injection. The results suggest that 20‐hydroxyecdysone acts by stimulating the growth of ovary.
Tyrosinase catalyzed protein polymerization as an in vitro model for quinone tanning of insect cuticle
Authors: Sugumaran Manickam , Hennigan Brian , O'Brien Jean 
Published: February 2005

AbstractThe validity of Pryor's widely accepted quinone tanning hypothesis for the sclerotization of insect cuticle was examined using an in vitro model system. Quinones generated in situ by the oxidation of catechols with mushroom tyrosinase and molecular oxygen readily reacted with test proteins such as lysozyme, ribonuclease and cytochrome‐c, producing dimers, trimers, and higher oligomers. With the exception of 3,4‐dihydroxyphenylalanine, dopamine, and norepinephrine, most other catechols tested participated in protein polymerization. The inability of these three compounds to support oligomerization of test protein was attributed to their high rate of intramolecular cyclization reaction. Radioactive incorporation studies reveal the formation of catechol‐protomer adducts, as well as aryl‐protein crosslinks in the reaction mixture. The above results strongly support the quinone tanning hypothesis. Based on these findings, the mechanism of cuticular sclerotization is discussed.