bluuebunny/crossref_metadata_2025 huggingface dataset:
Spinocerebellar ataxia type 26 maps to chromosome 19p13.3 adjacent to SCA6
Authors: Yu Guo‐Yun , Howell Michael J. , Roller Matthew J. , Xie Ting‐Dong , Gomez Christopher M.
Published: February 2005

The dominantly inherited spinocerebellar ataxias (SCA) are a clinically and genetically heterogeneous group of neurodegenerative disorders characterized by progressive gait ataxia, upper limb incoordination, and dysarthria. We studied a six‐generation kindred of Norwegian ancestry with pure cerebellar ataxia inherited in an autosomal dominant pattern. All affected family members had a slowly progressive cerebellar ataxia, with an age of onset range from 26 to 60 years. Brain magnetic resonance imaging study of 11 affected patients showed that atrophy was confined to the cerebellum. After excluding all the known SCAs using linkage analysis or direct mutation screen, we conducted a genomewide genetic linkage scan. With the aid of a novel linkage analysis strategy, we found linkage between the disease locus and marker D19S591 and D19S1034. Subsequent genetic and clinical analysis identified a critical region of 15.55cM interval on chromosome 19p13.3, flanked by markers D19S886 and D19S894, and have established a new genetic locus designated SCA26. The SCA26 locus is adjacent to the genes for Cayman ataxia and SCA6. The region consists of 3.3 million base pairs (Mb) of DNA sequences with approximately 100 known and predicted genes. Identification of the responsible gene for SCA26 ataxia will provide further insight into mechanisms of neurodegeneration. Ann Neurol 2005;57:349–354
Fewer thymic changes in MuSK antibody‐positive than in MuSK antibody‐negative MG
Authors: Leite Maria Isabel , Ströbel Philipp , Jones Margaret , Micklem Kingsley , Moritz Regina , Gold Ralf , Niks Erik H. , Berrih‐Aknin Sonia , Scaravilli Francesco , Canelhas Aurea , Marx Alexander , Newsom‐Davis John , Willcox Nick , Vincent Angela
Published: February 2005

In generalized myasthenia gravis (MG) patients without detectable acetylcholine receptor (AChR) antibodies (SNMG), the thymus is often reported as “normally involuted.” We analyzed thymic compartments in 67 patients with generalized MG, with AChR antibodies (AChR+, n = 23), with muscle‐specific kinase (MuSK) antibodies (MuSK+, n = 14) or with neither (MuSK−, n = 30), and in 11 non‐MG controls. Four of 14 MuSK+ thymi had rare small germinal centers, but overall they were not different from age‐matched controls. However, approximately 75% MuSK− samples showed lymph node–type infiltrates similar to those in AChR+ patients, but with fewer germinal centers. These variations may explain some apparent differences in responses to thymectomy in SNMG. Ann Neurol 2005;57:444–448
Interaction of α‐synuclein and tau genotypes in Parkinson's disease
Authors: Mamah Catherine E. , Lesnick Timothy G. , Lincoln Sarah J. , Strain Kari J. , de Andrade Mariza , Bower James H. , Ahlskog J. Eric , Rocca Walter A. , Farrer Matthew J. , Maraganore Demetrius M.
Published: February 2005

To determine whether the microtubule‐associated protein tau (MAPT) and α‐synuclein (SNCA) genes interact to confer Parkinson's disease (PD) susceptibility, we conducted a study of 557 case–control pairs. There was an increased risk of PD for persons with either SNCA 261/261 or MAPT H1/H1 genotypes as compared with persons with neither (odds ratio, 1.96; 95% confidence interval, 1.34–2.86; p = 0.0003). However, the combined effect of the two genotypes was the same as for either of the genotypes alone (separate and equal). These findings are consistent with in vitro experiments that revealed tau‐mediated fibrillization of α‐synuclein protein at low concentrations (dose threshold effect). Ann Neurol 2005;57:439–443
Acute tetrodotoxin‐induced neurotoxicity after ingestion of puffer fish
Authors: Kiernan Matthew C. , Isbister Geoffrey K. , Lin Cindy S.‐Y. , Burke David , Bostock Hugh
Published: February 2005

This study documents the effects of puffer‐fish poisoning on peripheral nerve. Excitability measurements investigated membrane properties of sensory and motor axons in four patients. The median nerve was stimulated at the wrist, with compound muscle potentials recorded from abductor pollicis brevis and compound sensory potentials from digit 2. Stimulus–responses, strength–duration time constant (τSD), threshold electrotonus, and current–threshold relations were recorded. The urine of each patient tested positive for tetrodotoxin. Compared with controls, axons were of higher threshold, compound muscle action potentials and compound sensory nerve action potentials were reduced in amplitude, latency was prolonged, and τSD was reduced. In recovery cycles, refractoriness, superexcitability, and late subexcitability were decreased. Threshold electrotonus of motor axons exhibited distinctive abnormalities with less threshold decline than normal on depolarization and greater threshold increase on hyperpolarization (p < 0.0005 for each patient). The changes in excitability were reproduced in a mathematical model by reducing sodium (Na+) permeabilities by a factor of two. This study confirms that the neurotoxic effects of puffer‐fish poisoning can be explained by tetrodotoxin blockade of Na+ channels. It demonstrates the ability of noninvasive nerve excitability studies to detect Na+ channel blockade in vivo and also the utility of mathematical modeling to aid interpretation of altered excitability properties in disease. Ann Neurol 2005;57:339–348
Assessment of nerve degeneration by gadofluorine M–enhanced magnetic resonance imaging
Authors: Bendszus Martin , Wessig Carsten , Schütz Ansgar , Horn Tanja , Kleinschnitz Christoph , Sommer Claudia , Misselwitz Bernd , Stoll Guido
Published: February 2005

Nerve injury represents a major cause of disability. In the peripheral nervous system, nerves have the capacity to regrow but within weeks after injury, it is impossible to clarify whether proper regeneration is under way or is failing. In this experimental study, we report on a novel tool to assess nerve outgrowth in vivo. After systemic application, the novel gadolinium‐based magnetic resonance (MR) contrast agent Gadofluorine M (Gf) selectively accumulated and persisted in nerve fibers undergoing Wallerian degeneration causing bright contrast on T1‐weighted MR images. Gf enhancement on MR imaging was present already at 48 hours within the entire nerve segments undergoing Wallerian degeneration, and subsequently disappeared from proximal to distal parts in parallel to regrowth of nerve fibers. Most importantly, Gf enhancement persisted in nonregenerating, permanently transected nerves. Our novel Gf‐based MR imaging methodology holds promise for clinical use to bridge the diagnostic gap between nerve injury and completed nerve regeneration, and to determine the necessity for neurolysis and engraftment if spontaneous regeneration is not successful. Ann Neurol 2005;57:388–395
Mutations in senataxin responsible for Quebec cluster of ataxia with neuropathy
Authors: Duquette Antoine , Roddier Katel , McNabb‐Baltar Julia , Gosselin Isabelle , St‐Denis Anik , Dicaire Marie‐Josée , Loisel Lina , Labuda Damian , Marchand Luc , Mathieu Jean , Bouchard Jean‐Pierre , Brais Bernard
Published: February 2005

Senataxin recently was identified as the mutated gene in ataxia‐oculomotor apraxia 2, which is characterized by ataxia, oculomotor apraxia, and increased α‐fetoprotein levels. In this study, we evaluated 24 ataxic patients from 10 French‐Canadian families. All cases have a homogeneous phenotype consisting of a progressive ataxia appearing between 2 and 20 (mean age, 14.8) years of age with associated dysarthria, saccadic ocular pursuit, distal amyotrophy, sensory and motor neuropathy, and increased α‐fetoprotein levels but absence of oculomotor apraxia. Linkage disequilibrium was observed with markers in the ataxia‐oculomotor apraxia 2 locus on chromosome 9q34. We have identified four mutations in senataxin in the French‐Canadian population including two novel missense mutations: the 5927T→G mutation changes the leucine encoded by codon 1976 to an arginine in the helicase domain (L1976R), and the 193G→A mutation changes a glutamic acid encoded by codon 65 into a lysine in the N‐terminal domain of the protein (E65K). The common L1976R mutation is shared by 17 of 20 (85%) carrier chromosomes. The study of this large French‐Canadian cohort better defines the phenotype of this ataxia and presents two novel mutations in senataxin including the more common founder mutation in the French‐Canadian population. Ann Neurol 2005;57:408–414
Synthesis and characterization of thermosensitive composite microsphere latex
Authors: Yi Changfeng , Xu Zushun
Published: February 2005

Monodisperse aqueous latex dispersions, prepared from mixtures of styrene, N‐isopropylacrylamide, and N,N′‐methylenebisacrylamide, were characterized. Thermosensitive composite microspheres with diameters greater than 1.0 μm, consisting of a polystyrene core and a poly(N‐isopropylacrylamide) shell, were prepared. The morphology of the composite microspheres was observed with transmission electron microscopy, and the particle size of the composite microspheres was estimated with dynamic light scattering. The thermosensitive properties of the composite microspheres were evaluated via the hydrodynamic size of the composite microspheres. The particle size of the composite microspheres decreased with increasing temperature. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 824–828, 2005
Sharkskin mechanism of high‐impact polystyrene (HIPS) and rheological behavior of HIPS/TiO2 composites
Authors: Wang Xin , Wang Zhaobo , Wu Qiye
Published: February 2005

The rheological behaviors of high‐impact polystyrene (HIPS) and HIPS/TiO2 composites were investigated by use of a rheometer in the present article. HIPS exhibited a constant critical stress of the sharkskin in various temperatures, and the analysis indicated that the mechanism of sharkskin of HIPS was wall–slip and its special temperature dependency was determined by weak wall–melt adsorption. The experimental results also showed that the introduction of TiO2 into HIPS only slightly influenced the apparent viscosity (ηa) of the composites. Moreover, TiO2 exhibited an unusual effect on the non‐Newtonian index of the composites at high shear rate. Both phenomena indicated the increase of inner free volume induced by TiO2 in molecularly rigid HIPS. Moreover, it was noteworthy that a featured stress could be used to label the dispersion of TiO2 in the HIPS matrix, and the numeric affinity of this featured stress and the critical stress of sharkskin revealed that both processes were relevant to the same molecular relaxation. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 802–807, 2005
Evidence for a presynaptic action of chlordimeform at the insect neuromuscular junction
Authors: Yamamoto Daisuke , Washio Hiroshi , Fukami Jun‐Ichi
Published: February 2005

The mechanism of action of chlordimeform on the mealworm nerve‐muscle preparation was studied with microelectrodes. Chlordimeform affected neither the mean amplitude nor the frequency of spontaneous miniature excitatory postsynaptic potentials. Extracellular focal recordings show that in the presence of 0.8 mM chlordimeform the presynaptic spike is almost unchanged, but the quantal content for evoked transmitter release is reduced. It is suggested that chlordimeform decreases the influx of calcium at the presynaptic terminal during the active phase of the nerve terminal action potential, thereby inhibiting evoked transmitter release.
Conversion of ecdysone and 20‐Hydroxyecdysone into 26‐OIC derivatives is a major pathway in larvae and pupae of species from three insect orders
Authors: Lafont René , Blais Catherine , Beydon Philippe , Modde Jean‐François , Enderle Ulrike , Koolman Jan
Published: February 2005

Insects convert ecdysone and 20‐hydroxyecdysone into their corresponding 26‐oic derivatives, named ecdysonoic acid and 20‐hydroxyecdysonoic acid respectively. The conversion takes piace in several tissues and can either be the only pathway for converting ecdysone into highly polar ecdysteroids, or coexist with various conjugating mechanisms.

20‐Hydroxyecdysonoic acid was isolated from Pieris brassicae pupae as its methyl ester derivative. Its chemical structure was identified by Cl/D mass spectrometry and compared with a synthetic compound (20‐hydroxy‐25‐deoxyecdysonoic acid) chemically prepared by oxidation of inokosterone (20,26‐dihydroxy‐25‐deoxyecdysone). Natural ecdysonoic acids appear to exist as a mixture of 25R and 25S isomers.

The significance of this pathway is discussed in comparison with similar reactions occuring in the metabolism of steroid hormones in vertebrates.
Absence of phytosterol dealkylation and identification of the major ecdysteroid as makisterone A in Dysdercus fasciatus (Heteroptera, Pyrrhocoridae)
Authors: Gibson J. M. , Majumder M. S. I. , Mendis A. H. W. , Rees H. H.
Published: February 2005

The absence of phytosterol dealkylation in the cotton stainer bug, Dysdercus fasciatus, has been established and the major ecdysteroid in the fifth‐stage larvae identified. The demonstration that the free and esterified sterols in D fasciatus consisted of 95–96% sitosterol and 4–5% campesterol, a similar composition to the cottonseed diet, together with the lack of conversion of [14C]sitosterol into cholesterol, establishes that phytosterol dealkylation does not occur in this insect species. The ecdysteroid titer determined by radioimmunoassay in the fifth instar of D fasciatus shows a distinct peak at day 6, the instar lasting for 7 days. Makisterone A was purified by HPLC from insects at a time of high ecdysteroid titer and identified as a major component by both fast atom bombardment and electron impact mass spectrometry. Gas‐liquid chromatography/mass spectrometry (selected ion monitoring) confirmed the occurrence of makisterone A and revealed the presence of two unidentified compounds. One of these occurs in a similar amount to makisterone A and may be 26‐hydroxymakisterone A, whereas only a minute amount of the other compound, which may be 20‐deoxymakisterone A, was present; further identification of the latter compounds is necessary. C27 ecdysteroids (eg, ecdysone and 20‐hydroxyecdysone) and C29 ecdysteroids (eg, podecdysone A) were undetectable. The specificity of the enzymes of ecdysteroid biosynthesis is discussed.
Precocious metamorphosis and wing formation in the pea aphid, Acyrthosiphon pisum, induced by precocene analogue 7‐ethoxy‐6‐methoxy‐2,2‐dimethylchromene
Authors: Kambhampati S. , Mackauer M. , Nair K. K.
Published: February 2005

Maternal treatment with 5 μg of the precocene analogue 7‐ethoxy‐6‐methoxy‐2,2‐dimethylchromene influenced offspring development in the pea aphid, Acyrthosiphon pisum. Under conditions favoring the production of apterous offspring, virginoparous aphids produced a significant proportion of alates and precocious adultoids; the precocious adultoids were sterile. The effect of precocene on offspring development was temporary. Some implications of precocene treatment for aphid control are discussed.
Hemolytic activities of stinging insect venoms
Authors: Schmidt Justin O. , Blum Murray S. , Overal William L.
Published: February 2005

The direct hemolytic activities of the venoms from 21 species of stinging insects were determined. The activities spanned 3 1/2 orders of magnitude, ranging from a low of four to a high of 12,000 hemolytic units/mg dry venom, respectively, for the solitary wasp, Dasymutilla lepeletierii, and the social wasp, Polistes infuscatus. The latter activity is the highest reported for any insect venom and represents a level that is potentially harmful to humans stung by the wasp.

The social wasps as a group generally possessed highly hemolytic venoms; the ants, poorly hemolytic venoms; and the solitary stinging species, venoms with extremely low activity. For the venoms, hemolytic activity correlated with neither lethal toxicity (LD50) nor algogenicity. This finding suggests that hemolysins alone do not determine venom toxicity, and that the hemolysins of stinging insect venoms serve a variety of poorly understood roles. The range of activity of hemolysins from different venoms indicates they probably have different chemical structures and functions.
Tissue‐specificity of hemoglobin synthesis: Localization of heme synthesis in the subepidermal fat body of Chironomus thummi (Diptera)
Authors: Vafopoulou‐Mandalos Xanthe , Laufer Hans
Published: February 2005

Possible sites of heme synthesis in the fourth instar of Chironomus thummi were investigated by means of autoradiography of specific isotope incorporation. “Body wall” preparations, which include subepidermal and visceral fat body, oenocytes, muscle, epidermis, and cuticle, were cultured for 1 h in a medium containing tritiated‐δ‐aminolevulinic acid, a specific precursor to heme biosynthesis. Light‐microscopic examination of autoradiographs of sections of the body walls indicates that the subepidermal fat body is the major site of incorporation of the precursor into heme. The visceral fat body shows few silver grains. Oenocytes, as well as muscle and epidermis, are characterized by absence of silver deposits. These findings indicate that the subepidermal fat body of Chironomus is the primary site of heme synthesis, and are discussed in relation to specific hemoglobin synthesis.
Sublethal effects of neuroactive compounds on pheromone response thresholds in male oriental fruit moths
Authors: Linn C. E. , Roelofs W. L.
Published: February 2005

The pheromone‐mediated flight behavior of male Oriental fruit moths in a sustained‐flight tunnel was observed after males were treated topically with sublethal concentrations of permethrin, carbaryl, chlordimeform, dieldrin, octopamine, serotonin, yohimbine, and cyproheptadine. With the exception of serotonin all compounds were found to disrupt one or more specific elements of the male precopulatory flight sequence. Among the insecticides, dieldrin was least active, whereas permethrin, carbaryl, and chlordimeform induced unique effects at specific phases of the sequence. Octopamine induced a hypersensitivity to the olfactory signal and mimicked one of the effects observed with chlordimeform. Yohimbine and cyproheptadine significantly decreased moth activation to the chemical signal but did not alter flight performance in responding moths. Yohimbine and cyproheptadine also reversed the effects induced by octopamine. The results of our study show that the complex precopulatory sequence of behaviors exhibited by males is very sensitive to sublethal concentrations of a range of neuroactive compounds.
Chemical and immunological properties of lipophorins from seven insect orders
Authors: Ryan Robert O. , Law John H. , Schmidt Justin O.
Published: February 2005

The major insect hemolymph lipoprotein, lipophorin, was isolated from adults of eight insect species representing seven insect orders. Sodium dodecyl sulfate polyacrylamide gel electrophoresis was used to compare their respective apoprotein components. In all species examined lipophorin was composed of at least two apoproteins, apolipophorin I (Mr ∼ 250,000) and apolipophorin II (Mr ∼ 78,000), and two species had a third apoprotein, apolipophorin III (Mr ∼ 17,000). The density of each isolated lipophorin was determined from the refractive index of KBr following density gradient centrifugation. Immunoblotting with anti‐larval Manduca sexta apolipophorin I and II of the apoproteins separated by SDS‐PACE indicated cross reactivity between anti‐M sexta apoLp‐ll and apoLp‐ll in all species tested. Anti‐M sexta apoLp‐l exhibited no cross reactivity for any species tested. Fluorescent lectin staining of the apoproteins separated on SDS‐PAGE gels revealed the presence of covalently bound carbohydrate residues.
Ecdysteroid level and the change in sensitivity to a juvenile hormone analogue in Ephestia cautella larvae (Lepidoptera, Phycitidae)
Authors: Lazarovici P. , Shapira D. , Pisarev V. , Shaaya E.
Published: February 2005

A double‐antibody ecdysone‐specific radioimmunoassay was used to clarify whether the effects on metamorphosis of the juvenile hormone analogue methoprene are correlated with changes in ecdysteroids level. It appears that a small ecdysteroids peak, 5 days before pupation, is responsible for the transition from inhibition to defective metamorphosis. Study of the changes in ecdysteroid titer in last‐instar larvae treated with the JHA 2 days prior to the appearance of the above small ecdysteroids' peak showed an immediate reduction in ecdysteroid level, followed by cyclic, successively reduced titer for about 20 days. After this period the larvae ceased to feed and entered to a diapauselike stage which ended in the death of the larvae. A similar effect on ecdysteroid titer and developmental arrest was exhibited by JHA‐treated first‐instar larvae. The mechanism of the interactions between JHA and ecdysteroid level deserves further investigation.
The mechanism of block of glutamate synapses by dipicolinic acid
Authors: Yamamoto Daisuke , Miyamoto Takenori , Oda Masatsugu , Usui Toako , Fukami Jun‐Ichi
Published: February 2005

The effect of dipicolinic acid (2,6‐pyridine dicarboxylic acid) on the mealworm neuromuscular junction was studied using conventional microelectrode recording techniques. Dipicolinic acid (10−5‐10−3 M) added to the bathing solution reversibly blocked neuromuscular transmission. The depolarization in response to iontophoretically applied L‐glutamate (glutamate potential) was not affected by dipicolinic acid even when the neurally evoked excitatory postsynaptic potential (EPSP) was totally abolished. Focal extracellular recordings from single synaptic sites revealed that in the presence of 1 x 10−4 M dipicolinic acid the presynaptic spike was unchanged, but the quantal content for evoked transmitter release was reduced. The calcium‐dependent action potential elicited by direct stimulation of the muscle fiber was not impaired by dipicolinic acid. These results suggest that dipicolinic acid interferes with the transmitter‐releasing mechanism from the presynaptic terminal.
Vitamin C enhancement of brood rearing by caged honeybees fed a chemically defined diet
Authors: Herbert E. W. , Vanderslice J. T. , Higgs D. J.
Published: February 2005

Pollen collected by bees was sampled during a 3‐h period once a week from April to October 1983 and analyzed for vitamin C (L‐ascorbic acid and dehydroascorbic acid). The levels were highly variable and ranged from a low of 136 μg/g pollen (April) to a high of 1943 μg/g pollen (May). Overall, caged honeybees fed diets containing 1,000 and 2,000 μg/g L‐ascorbic acid reared significantly more bees to the sealed stage than bees fed diets with 500 μg/g ascorbic acid or control bees. The levels of vitamin C in prepupae reared by bees ranged from 64.5 to 103.5 μg/g body mass. Vitamin C is either synthesized from simple precursors or from symbiotic microorganisms in the gut since honeybees fed the ascorbic acid‐free control had equivalent levels of ascorbic acid to those fed the enriched diets. The total diet consumption by bees during the 10‐week study showed that the four diets were equally attractive.
Agonistic action of synthetic analogues of quisqualic acid at the insect neuromuscular junction
Authors: Miyamoto T. , Oda M. , Yamamoto D. , Kaneko Junko , Usui Toako , Fukami J.
Published: February 2005

One hundred twenty analogues of quisqualic acid were synthesized and assayed on the neuromuscular junction of larva of the mealworm, Tenebrio molitor. Two new agonists for amino acid receptors, L‐glutamic acid N‐thiocarboxyanhydride (L‐GANTA) and DL‐hydantoinpropionic acid (DL‐HPA), were discovered in this study. L‐GANTA and DL‐HPA produced muscle membrane depolarization, accompanied by a reduction of the muscle input resistance. The amplitude of excitatory postsynaptic potentials was decreased in the presence of L‐GANTA and DL‐HPA. The apparent dissociation constants obtained from dose‐depolarization plots were 7 x 10−4 M for L‐GANTA and 9 x 10−4 M for DL‐HPA. Some structural constraints imposed on agonists at amino acid receptors on insect muscle were discussed.
Rapid in vitro activation of corpora allata by extracted locust brain allatotropic factor
Authors: Gadot Michal , Applebaum Shalom W.
Published: February 2005

Brains of young (newly emerged) adult female locusts (Locusta migratoria migratorioides) and of mature (> 9 days old) locusts contain an extractable allatotropic factor, soluble in 100% methanol and in distilled water. This factor stimulates juvenile hormone III (JH III) synthesis and release from corpora allata (CA) that have been excised from donor locusts and then incubated with (radiolabeled methyl)‐methionine in vitro in its presence. In addition to JH III, which is the major product synthesized by the CA, other hexanesoluble, radiolabeled compounds–‐more polar than JH III–‐are also released when CA are incubated in vitro. The activation of CA by the allatotropic factor is rapid and quickly declines when the factor is removed from the medium. Corpora allata excised from young females are marginally active and can be activated by brain allatotropic factor to less of an extent than CA of mature locusts. The content of allatotropic factor in brains of mature locusts is higher than that ascertained in brains of young females. Allatotropic factor is also present in the corpora cardiaca.
Juvenile hormone acid methyltransferase activity in imaginal discs of Manduca sexta prepupae
Authors: Sparagana Steven P. , Bhaskaran Govindan , Barrera Punnee
Published: February 2005

The occurrence of a peak of juvenile hormone (JH) during the prepupal period has been noted in several lepidopterans. In Manduca sexta and Hyalophora cecropia this peak is known to prevent the precocious onset of adult differentiation in imaginal tissues. However, it has previously been observed in our laboratory that corpora allata (CA) of this age are incapable of making JH owing to a lack of the terminal synthetic enzyme, juvenile hormone acid methyltransferase (JHAMT). Since the CA are required for normal pupation, it is likely that JH acid is the product released by the prepupal CA. Therefore, we analyzed whether JH acid treatment would prevent precocious adultoid differentiation in allatectomized M. sexta larvae. JH acid injections were found to be as effective as JH in normalizing pupation, and acted in a time‐ and dose‐dependent manner. This finding led to a question of whether injected or endogenous JH acid could be methylated to JH. Homogenates of several tissues from prepupae were assayed for the presence of JHAMT. Of the tissues assayed, only imaginal discs possessed significant levels of the enzyme. These results support our previously proposed mechanism for production of the prepupal JH peak in M. sexta.
New ecdysteroid conjugate: Isolation and identification of 26‐hydroxyecdysone 26‐phosphate from eggs of the tobacco hornworm, Manduca sexta (L.)
Authors: Thompson Malcolm J. , Weirich Gunter F. , Rees Huw H. , Svoboda James A. , Feldlaufer Mark F. , Wilzer Kenneth R.
Published: February 2005

The major ecdysteroid conjugate present in eggs (48–64 h old) of the tobacco hornworm has been purified by XAD‐2 chromatography, C18 SEP‐PAK separations, and ion suppression reversed‐phase high‐performance liquid chromatography. Enzymatic hydrolysis of the conjugate with acid phosphatase from human seminal fluid gave 26‐hydroxyecdysone. The conjugate was identified as 26‐hydroxyecdysone 26‐phosphate by nuclear magnetic resonance and fast atom bombardment mass spectrometry. This compound is also the major conjugate of newly laid eggs (0–1 h old) of the tobacco hornworm. The role for ecdysteroid conjugates is discussed.
Comparative studies on ecdysone metabolism between mature larvae and pharate pupae in the fleshfly, Sarcophaga peregrina
Authors: Moribayashi Atsuko , Kurahashi Hiromu , Ohtaki Tetsuya
Published: February 2005

Metabolites of radioactive ecdysone or 20‐hydroxyecdysone in larvae and pharate pupae of Sarcophaga peregrina were separated and identified by using thin‐layer chromatography, high‐performance liquid chromatography, and chemical methods. At the larval stage ecdysone was metabolized to biologically less active ecdysteroids predominantly through 20‐hydroxyecydsone, at the pharate pupal stage, to other ecdysteroids which were tentatively identified as 26‐hydroxyecdysone, 3‐epi‐26‐hydroxyecdysone, and 3‐epi‐20,26‐dihydroxyecdysone. Ecdysteroid acids were found in the polar metabolites during pharate pupal‐pupal transformation, but scarcely detected in the larval metabolites. These acids were presumed to be ecdysonoic acid, 20‐hydroxyecdysonoic acid, and their epimers. The conjugates of ecdysteroid that released the free ecdysteroids by enzymatic hydrolysis were produced more in larvae than in pupae, whereas the very polar ecdysteroids that were not affected by the enzyme were found more in pupae. Therefore, there are different metabolic pathways of ecdysone between these two successive developmental stages, and the alteration of the metabolic pathway may serve as one of the important factors in a regulatory mechanism of molting hormone activity which is responsible for normal development of this insect.
Ecdysone 20‐monooxygenase in mitochondria and microsomes of Manduca sexta (L.) Midgut: Is the dual localization real?
Authors: Weirich Gunter F. , Svoboda James A. , Thompson Malcolm J.
Published: February 2005

The dual localization of ecdysone 20‐monooxygenase in mitochondria and microsomes of Manduca sexta larval midgut was investigated. Cosubstrate requirements and response to osmolarity of the microsomal ecdysone 20‐monooxygenase system were found to be different from those previously reported for the mitochondrial enzyme system. The microsomal monooxygenase utilized NADPH and, less efficiently, NADH as cosubstrates. NADPH and NADH effects were neither additive nor synergistic. NADPH yielded identical activities in isotonic and hypotonic incubations. Mitochondria and microsomes showed no synergistic interaction for ecdysone 20‐hydroxylation. After washing of the mitochondria, a large proportion of their ecdysone 20‐monooxygenase activity was lost. The extent of the loss was inversely correlated to the concentration of mitochondria in the incubation mixture. The addition of bovine serum albumin to the incubations (2 mg/ml) largely restored the original activities. The microsomal contamination in mitochondrial pellets after each of three successive washings was determined by measuring the activity of a microsomal marker enzyme, NADPH‐cytochrome c reductase. At each step of the purification, the ecdysone 20‐monooxgenase activity of the mitochondrial preparations far exceeded the activity attributable to the microsomal contamination. These results confirm the existence of two independent ecdysone 20‐monooxygenase systems in the midgut of M. sexta larvae.
Sterols of phytophagous and omnivorous species of Hymenoptera
Authors: Svoboda James A. , Lusby William R.
Published: February 2005

The sterols of six species of Hymenoptera including two phytophagous species (Apis mellifera and Megachile rotundata) and four omnivorous species (Dolichovespula maculata, Vespula maculifrons, Formica exsectoides, and Solenopsis invicta) were isolated and identified. The two phytophagous species of bees have in common relatively high levels of 24‐methylenecholesterol and very low levels of cholesterol (<1% of total sterols). The isofucosterol content (40.7%) of M. rotundata was nearly three times that of A. mellifera, but overall utilization of dietary sterols in the two species is similar in that neither is able to convert C28 and C29 phytosterols to cholesterol. All four omnivorous species are predatory to some extent, and the fact that their usual dietary sterols include high levels of chlosterol is reflected in the sterols isolated from these species, which contain 45–81% cholesterol. All six hymenopteran species appear to utilize dietary sterols for structural needs with little or no metabolic modification of the steroid structure.
Superoxide dismutase in the housefly, Musca domestica (L.)
Authors: Bird Thomas G. , Salin Marvin L. , Boyle John A. , Heitz James R.
Published: February 2005

Four superoxide dismutase (SOD) (E.C. 1.15.1.1) isozymes were present in whole tissue homogenates of Musca domestica when examined by polyacrylamide gel electrophoresis. One of the isozymes contained manganese, and the other three contained copper and zinc. All were observed in each of the body tagma (head, abdomen, and thorax) and at each developmental stage (egg to adult).

The copper‐ and zinc‐containing isozymes purified from newly emerged, adult M. domestica had a relative molecular weight of 34,800 as determined by gel filtration chromatography but consisted of two equal‐size subunits of 16,000 as measured by sodium dodecylsulfate polyacrylamide gel electrophoresis. An isoelectric point between 4.8 and 5.1 was measured. Approximately 2 mol each of copper and zinc were present per dimer. The three copper, zinc isozymes were identified as charge variants. The amino acid composition of the enzyme was similar to that of copper, zinc‐containing superoxide dismutases from other sources.

Purified housefly copper, zinc superoxide dismutase was neither deactivated nor able to protect lactic dehydrogenase against deactivation in the presence of light and rose bengal, a known generator of singlet oxygen. The role of SOD in the phototoxic reaction involving rose bengal is discussed.
Inhibition of hydrocarbon biosynthesis in the housefly by 2‐Octadecynoate
Authors: De Renobales Mertxe , Wakayama Edgar J. , Halarnkar Premjit P. , Reitz Ronald C. , Pomonis J. George , Blomquist Gary J.
Published: February 2005

The elongation of [9,10‐3H]oleoyl‐CoA with malonyl‐CoA to form 20, 22, and 24 carbon monounsaturated fatty acids was demonstrated in housefly microsomes by radio‐GLC. These elongation reactions, which have been postulated to be involved in hydrocarbon biosynthesis, have not been previously demonstrated in insects. 2‐Octadecynoate (18:1 Δ2=) inhibited the in vivo incorporation of [1‐14C]acetate into both fatty acids and hydrocarbons in a dose‐dependent manner. At doses of 10 μg per female housefly of the alkynoic acid, the incorporation of [1‐14C]acetate into hydrocarbon was inhibited 93%, the incorporation of [9,10‐3H]oleate into hydrocarbon was inhibited 64%, and the incorporation of [1‐14C]acetate into total internal lipid was inhibited 65%. Partially purified FAS was inhibited 50% and 95% at 15 μM and 40 μM, respectively, of the alkynoic acid. These results show that 2‐octadecynoate inhibits hydrocarbon biosynthesis in the housefly by inhibiting FAS, and the in vivo data suggest that the elongation of 18:1 to longer chain fatty acids is also inhibited.
Binding of insecticides to lipophorin and arylphorin, two hemolymph proteins of Heliothis zea
Authors: Haunerland Norbert H. , Bowers William S.
Published: February 2005

The binding of different insecticides to hemolymph proteins of the corn earworm, Heliothis zea, was studied by an analytical isoelectric focusing technique. Two proteins capable of binding hydrophobic substrates were discovered and identified as lipophorin and arylphorin. Lipophorin, the major lipoprotein of Heliothis zea, demonstrated rather unspecific binding of xenobiotics of different hydrophobicities. Arylphorin, a putative storage protein, revealed strong affinity for compounds of medium polarity, binding only weakly to insecticides of higher or lower polarity.
Proteolytic enzymes and blood digestion in the mosquito, Culex nigripalpus
Authors: Borovsky Dov
Published: February 2005

The synthesis of proteolytic enzymes in the fat body and midgut of female Culex nigripalpus was followed. The effects of brain factor(s) and RNA levels in the fat body were correlated with the synthesis of proteolytic enzymes. Trypsinlike activity in the midgut of C. nigripalpus accounted for 80% of total proteolytic activity, whereas chymotrypsinlike activity accounted for 5–7% of total proteolytic activity. Synthesis of porteases in the midgut and fat body reached a peak at 35 h and 22 h after the blood meal, respectively. In the fat body, proteolytic enzyme activity fell to a low level 30 h after the blood meal, but activity in the midgut reached a low level 58 h after the blood meal. The presence of low protease activity in the fat body at the time of peak vitellogenin synthesis indicated that processing of vitellogenin was not done in this tissue.

Fat bodies incubated in vitro in the presence of [14C]valine synthesized a [14C]labeled trypsinlike molecule identified as such with antitrypsin antibodies and specific substrate p‐toluene‐sulphonyl‐L‐arginine methylester (TAME) and on disc gel electrophoresis in the presence of dodecyl sulfate. The sizes of the proteins found inside and outside the peritrophic membrane were determined by gel‐chromatography and disc gel electrophoresis in the presence of dodecyl sulfate. The molecular weight (± SEM) of the largest polypeptide that migrated through the peritrophic membrane into the ectoperitrophic space was found to be 23,000 ± 2,000 daltons. Based on these results, a model is proposed to account for blood digestion in the mosquito midgut, along with the role of the peritrophic membrane.
Ecdysteroids in testis sheaths of Heliothis virescens larvae: An immunocytological study
Authors: Loeb M. J.
Published: February 2005

Testes of last‐instar larvae of the lepidopteran, Heliothis virescens, were examined by an immunocytological technique to locate tissues associated with ecdysteroids. Antiecdysteroid antibody, prepared in rabbits, was incubated with sections of testis. Sections were then exposed to antirabbit antibody coupled to horseradish peroxidase. Oxidized 3,3‐diaminobenzidine allowed visualization. Ecdysteroid was detected in tissues of the inner layer of the testis sheath and its extensions that form the follicle walls.
Properties of larval and imaginal membrane‐bound digestive enzymes from Trichosia pubescens
Authors: Espinoza‐Fuentes Fernando P. , Terra Walter R.
Published: February 2005

Trichosia pubescens larval midgut ceca cells display in their plasma membranes α‐glucosidases (Mr 95,000; pHo 5.5; Km 5.7 mM; Ki for TRIS 8.9 mM), trehalases (Mr 69,000; pHo 5.3; Km 0.92 mM; Ki for TRIS 57 mM), and aminopeptidases (Mr 95,000; pHo 8.7; Km 0.19 mM) which are solubilized by Triton X‐100. The enzymes were purified by electrophoresis and used to raise antibodies in a rabbit. T. pubescens imaginal midgut cells display in their plasma membranes an α‐glucosidase (Mr 156,000; pHo 5.8; Km 2.3 mM; Ki for TRIS 0.2 mM), a trehalase (Mr 93,000; pHo 5.5; Km 0.72 mM; Ki for TRIS 45.5 mM), and an aminopeptidase (Mr 210,000; pHo 9.0; Km 0.47 mM). Antiserum produced against the larval enzymes shows no precipitation arc when tested by double immunodiffusion or by immunoelectrophoresis with Triton X‐100‐solubilized membrane proteins from imaginal midguts. Otherwise, a similar test showed that larval midgut cecal enzymes and larval ventriculus enzymes display complete immunological identity. The data suggest that, despite the fact the larval and imaginal aminopeptidase, α‐glucosidase, and trehalase probably have similar functions, the genes coding for them in larvae and imagoes must differ.
Studies on vitellogenin from the tobacco hornworm, Manduca sexta
Authors: Osir Ellie O. , Wells Michael A. , Law John H.
Published: February 2005

In the tobacco hornworm moth, Manduca sexta, vitellogenin (Vg) is a very high‐density (1.29 g/ml) phosphoglycolipoprotein containing 13% lipids, 3% carbohydrates, and 0.6% protein‐bound phosphorus. Vitellogenin (Mr∼500,000) has two apoproteins designated apoVg‐l (Mr 177,000 ± 3,600) and apoVg‐ll (Mr45,000 ± 5,000). ApoVg‐l and apoVg‐II can be dissociated with 6 M guanidine HCI and separated from each other by gel permeation chromatography. Immunoblotting experiments using antibodies against the apoproteins showed that apoVg‐l and apoVg‐II antigens were immunologically distinct polypeptides. Antibodies against Vg reacted only with apoVg‐l. Antibodies against Vg and apoVg‐l reacted with Vg in double immunodiffusion experiments, whereas antibodies against apoVg‐II did not. These results suggest that in the native Vg molecule, apoVg‐II is positioned inside the molecule away from the aqueous environment. Only apoVg‐I contained covalently bound carbohydrate as shown by fluorescein isothiocyanateconjugated concanavalin A, periodate‐Schiff reagent, and in vivo labeling with 3H‐Man. In vivo labeling with 32P‐inorganic phosphate and chemical determination showed that apoproteins of both Vg and vitellin contain covalently bound phosphate groups.
Clones of Aedes albopictus cells resistant to methylmercaptopurine riboside
Authors: Malinoski Frank J. , Stollar Victor
Published: February 2005

Four clones of A. albopictus cells resistant to 6‐methylmercaptopurine riboside (MMPR) (MMPR‐10, ‐11, ‐12, and ‐21) were isolated after mutagenesis of the parental LT C‐7 cells. As assayed by plating efficiencies these clones were from ten‐ to 20‐fold more resistant to MMPR than the LT C‐7 cells. Resistance was also demonstrated by the fact that concentrations of MMPR, which reduced the levels of ATP and GTP in LT C‐7 cells, had no such effect in the MMPR‐resistant cells. When de novo purine biosynthesis was measured by the incorporation of [14C]formate into ATP and GTP, MMPR had little effect on the MMPR‐10 cells (15% inhibition) but did depress synthesis considerably in the MMPR‐11 cells (80% inhibition) although not as severely as in the LT C‐7 cells (95% inhibition). Three of the resistant clones which were tested also showed considerable resistance to guanosine. Although the mechanism of resistance to MMPR in these cells is not clear it likely involves some alteration in one of the early enzymes involved in purine biosynthesis. Resistant as well as sensitive cells showed a new high‐performance liquid chromatography peak after treatment with MMPR suggesting that there was no defect in the uptake of MMPR. The conversion of labeled adenosine to AMP, ADP, and ATP in the resistant cells indicated that these cells were not deficient in adenosine kinase, another possible mechanism of resistance to MMPR. All clones showed a reduction in GTP following treatment with ribavirin; however, they varied considerably with respect to the amount of ribavirin triphosphate which they formed. In the case of the MMPR‐11 cells the amount of ribavirin triphosphate formed was markedly sensitive to cultural conditions. The fact that the various MMPR‐resistant cells responded differently to ribavirin, and that quantitative differences were also seen in their responses to MMPR (as measured by [14C]formate incorporation) and to guanosine, suggests that there are significant phenotypic differences among these resistant clones.
Cuticular hydrocarbons from six species of tephritid fruit flies
Authors: Carlson D. A. , Yocom S. R.
Published: February 2005

Cuticular alkanes obtained from larvae and adults of six species of tephritid fruit flies, Anastrepha ludens, A. suspensa, Ceratitis capitata, C. rosa, Dacus cucurbitae, and D. dorsalis were analyzed by gas chromatography. The same four major alkanes were shown to be present by capillary GC‐mass spectra in all Anastrepha and Ceratitis larvae. Profiles were obtained from individual larvae and adult specimens that showed statistical differences between species, whereas profiles of conspecific life forms including pupae of A. suspensa from different locations showed some similarities. Sexual dimorphism was not observed in alkanes extracted from adults. A novel series of alkadienes was found in all Anastrepha and Ceratitis but not in Dacus.
Biochemical effects of sublethal doses of cypermethrin on the sixth‐instar larvae of Tribolium castaneum (Herbst.)
Authors: Saleem Mushtaq A. , Shakoori A. R.
Published: February 2005

Effects of sublethal doses ie, 2, 4, 10, and 20 ppm of cypermethrin, were studied on the sixth‐instar larvae of Tribolium castaneum (Herbst.). Of all the biochemical parameters tested, the free amino acids and cholesterol content and the activity of amylase were found to be the most sensitive components. Glutamate pyruvate transaminase activity was elevated at all doses except 2 ppm. The activities of alkaline phosphatase and glutamate oxaloacetate transaminase and glucose content were raised significantly at doses of 10 and 20 ppm. Acid phosphatase activity and the soluble protein content increased at a dose of 20 ppm. Total lipid and triglycerides, however, decreased significantly at this sublethal dose. Other biochemical parameters, such as cholinesterase and lactate dehydrogenase activities and the total protein, urea, glycogen, DNA, and RNA contents, were not significantly affected by exposure to different doses of cypermethrin.
Ecdysone 20‐hydroxylation in imaginal wing discs of Pieris brassicae (lepidoptera): Correlations with ecdysone and 20‐hydroxyecdysone titers in pupae
Authors: Blais Catherine , Lafont René
Published: February 2005

Ecdysone 20‐hydroxylase activity has been detected in pupal wing discs of Pieris brassicae. This activity is due to an enzyme system located in microsomal fractions. Its apparent Km is 58 nM for ecdysone. The enzyme is inhibited by the reaction product 20‐hydroxyecdysone with an apparent Ki of 2.6 μM. Its activity varied during pupal‐adult development with a maximum on day 4, when ecdysone levels are the highest in the animal. Although low, the peak activity is sufficient to assure 25% of the conversion of endogenous ecdysone into 20‐hydroxyecdysone in pupae. Ecdysone and 20‐hydroxyecdysone levels were measured in hemolymph and whole animals; ecdysone appears to be mainly located in hemolymph, whereas 20‐hydroxyecdysone seems to be equally distributed between hemolymph and tissues. All these findings are discussed in relation to the roles of ecdysone and 20‐hydroxyecdysone during pupal‐adult development.
Biosynthesis, purification, and characterization of Aedes aegypti vitellin and vitellogenin
Authors: Borovsky Dov , Whitney Philip L.
Published: February 2005

Vitellin, the major egg yolk protein, and vitellogenin, the hemolymph precursor of egg yolk protein, have been purified to apparent homogeneity from the mosquito Aedes aegypti. The purification procedure included chromatography on ion exchange, hydrophobic, and gel filtration columns. Vitellin and vitellogenin have a similar molecular weight (Mr 300,000) on gel filtration columns. However, the molecular weights of vitellin and vitellogenin, as determined from SDS electrophoresis, were 393,000 and 337,000, respectively.

Vitellin in sodium dodecyl sulfate released six subunits of molecular weight 116,000, 83,000, 75,000, 54,000, 36,000, and 29,000, whereas vitellogenin released only three subunits (155,000, 120,000, and 62,000). The average molecular weights of vitellin and vitellogenin after gel filtration and SDS electrophoresis were 346,000 and 318,000, respectively.

Vitellin has a high content of aspartic acid and glutamic acid, and a low content of histidine, methionine, cysteine, and tryptophan. Vitellin also contains 0.9% mol of glucosamine and no galactosamine. The isoelectric points of vitellin and vitellogenin are at pH 6.4 and 6.3, respectively.

Aedes aegypti fat bodies incubated for short intervals in tissue culture medium in the presence of [3H]valine showed incorporation by radio‐immunoprecipitation and SDS electrophoresis into three primary vitellogenin polypeptides of molecular weights (± SEM) 156,000 ± 4,000, 114,000 ± 5,000, and 62,000 ± 400 inside the fat body and 162,000 ± 3,000, 118,200 ± 2,000, and 63,000 ± 300 in the medium. These results suggest that the molecular weight of vitellogenin synthesized inside the fat body (Mr 332,000) remains unchanged when secreted into the hemolymph (Mr 343,000). The three vitellogenin subunits are processed by the ovary into six subunits which are then deposited in the yolk granules as vitellin.