bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of energetic amino acid metabolism inAcyrthosiphon pisum: A multidimensional approach to amino acid metabolism in aphids
Authors: Febvay Gérard , Liadouze Isabelle , Guillaud Josette , Bonnot Guy 
Published: February 2005

AbstractAphids are highly specialized insects that feed on the phloem‐sap of plants, the amino acid composition of which is very unbalanced. Amino acid metabolism is thus crucial in aphids, and we describe a novel investigation method based on the use of14C‐labeled amino acids added in an artificial diet. A metabolism cage for aphids was constructed, allowing for the collection and analysis of the radioactivity incorporated into the aphid body, expired as CO2, and rejected in the honeydew and exuviae. This method was applied to the study of the metabolism of eight energetic amino acids (aspartate, glutamate, glutamine, glycine, serine, alanine, proline, and threonine) in the pea aphid,Acyrthosiphon pisum. All these amino acids except threonine were subject to substantial catabolism as measured by high14CO2production. The highest turnover was displayed by aspartate, with 60% of its carbons expired as CO2. For the first time in an aphid, we directly demonstrated the synthesis of three essential amino acids (threonine, isoleucine, and lysine) from carbons of common amino acids. The synthesis of these three compounds was only observed from amino acids that were previously converted into glutamate. This conversion was important for aspartate, and lower for alanine and proline. To explain the quantitative results of interconversion between amino acids, we propose a compartmentation model with the intervention of bacterial endosymbiotes for the synthesis of essential amino acids and with glutamate as the only amino acid supplied by the insect to the symbiotes. Moreover, proline exhibited partial conversion into arginine, and it is suggested that proline is probably indirectly involved in excretory nitrogen metabolism. © 1995 Wiley‐Liss, Inc.
Oxidative stress from environmental pollutants
Authors: Ahmad Sami 
Published: February 2005

AbstractRecently progress has been made on O2 toxicity and pathology related to numerous environmental contaminants in insects. The pro‐oxidants studied included: dioxin, paraquat, and an assorted array of quinones, 8‐methoxypsorlen, arsenic, and mercury. The responses to these oxidants are diverse, but they arise from the reactive oxygen species. These pro‐oxidants in insects cause lipid peroxidation, protein and enzyme oxidation, and GSH depletion. Potentially, they may also cause DNA oxidation, and form DNA adducts. Oxidative challenge is alleviated by antioxidant compounds, but more importantly by the induction of antioxidant enzymes, which are crucial for the termination of O2 radical cascade and lipid peroxidation chain reaction. Insects exhibit a wasting syndrome under sub‐acute stress. In acute toxicity vital physiological processes impaired are hemolymph melanization and diuresis. Thus, insects resemble vertebrates in both the response to oxidative stress and its pathological consequences. These results raise the prospect that insects may serve as non‐mammalian model species for monitoring the oxidative‐stress component of environmental toxicity. © 1995 Wiley‐Liss, Inc.
How do insect herbivores cope with the extreme oxidative stress of phototoxic host plants?
Authors: Aucoin Richard , Guillet Gabriel , Murray Christine , Philogène Bernard J. R. , Arnason J. Thor 
Published: February 2005

AbstractPlants of the Asteraceae and Hypericaceae possess secondary compounds that induce photooxidation in insect herbivores that consume them. One of the well‐established modes of action of these substances is peroxidation of membrane lipids. Some herbivores counteract these defences by avoidance of light and tissues rich in phototoxins or the ability to detoxify these secondary substances. The cytochrome P‐450 polysubstrate monooxygenase systems involved, the metabolic products, and a new putative toxin pump have been described. Dietary antioxidants (β‐carotene, vitamin E, ascorbate) are additional defences against phototoxicity. They reduce mortality in herbivores exposed to phototoxins and some specialist herbivores have high constitutive levels. Adapted specialist insects also have higher constitutive levels of superoxide dismutase (SOD) and respond to phototoxins in their diet by the induction of catalase (CAT), glutathione reductase (GR), and increased levels of reduced glutathione (GSH). Artificial inhibition of the enzymes SOD and CAT had little effect on phototoxicity but inhibition of GSH synthesis in herbivores enhanced photooxidative effects of administered phototoxins on lipid peroxidation. While insects have many mechanisms to overcome plant photooxidants, the Asteraceae appear to have adopted a strategy of counterattack. We suggest and provide preliminary evidence that a second group of secondary substances, the sesquiterpene lactones, occurring in the Asteraceae can attack key antioxidant defences to synergise phototoxins. © 1995 Wiley‐Liss, Inc.
Biochemical characterization, developmental expression, and induction of the immune protein scolexin from Manduca sexta
Authors: Kyriakides T. R. , McKillip J. L. , Spence K. D. 
Published: February 2005

AbstractThe immune protein, scolexin, a bacteria‐induced, larva‐specific protein from Manduca sexta, was shown to exist in the hemolymph in two isoelectric forms designated herein as scolexin‐1 and scolexin‐2 (native Mr ∼ 72 kd). These two charge isomers appeared to share the same amino acid composition. Scolexin is composed of two subunits (peptide Mr ∼ 36 kd) that possess the same N‐terminus. Scolexin‐2 was subjected to glycosyl composition analysis, revealing the presence of galactose, glucose, mannose, xylose, and sialic acid residues. Hybridization of epidermal RNA with oligonucleotides deduced from the scolexin N‐terminal sequence showed a continuous decline in mRNA following day 0 of the 5th larval instar. By employing in vitro protein labelling, it was found that organ cultures of the epidermis from immune larvae showed a greater ability over that of naive epidermal cultures to synthesize scolexin; these data reflected the inducible response seen in the hemolymph, and confirm other data indicating that the epidermis is an important site of scolexin biosynthesis. © 1995 Wiley‐Liss, Inc.
Characterization of a novel esterase conferring insecticide resistance in the mosquito Culex tarsalis
Authors: Whyard Steven , Downe Aylward E. R. , Walker Virginia K. 
Published: February 2005

AbstractResistance to the organophosphate insecticide, malathion, in a strain of Culex tarsalis mosquitoes is due to increased activity of a malathion carboxylesterase (MCE). To determine whether resistance was due to a qualitative or quantitative change in the MCE, the enzyme was purified from both malathion‐resistant and ‐susceptible mosquitoes. Enzyme kinetic measurements revealed that the two strains have one MCE in common, but resistant mosquitoes also have a unique MCE which hydrolyses malathion 18 times faster. Interestingly, this MCE does not hydrolyse α‐naphthyl acetate, a substrate commonly used to detect increased levels of esterases in other organophosphate‐resistant insects. Unlike the over‐produced esterase of some related mosquito species, each MCE in C. tarsalis accounts for only a small fraction (0.015%) of the total extractable protein in either strain. Therefore, resistance in these insects is due to the presence of a qualitatively different enzyme, and not to a quantitative increase of a non‐specific esterase. This study therefore demonstrates that the underlying biochemical mechanisms of insecticide resistance in one insect cannot necessarily be predicted from those of another, even closely related species. © 1995 Wiley‐Liss, Inc.
Isolation of two AKH‐related peptides from cicadas
Authors: Veenstra Jan A. , Hagedorn Henry H. 
Published: February 2005

AbstractTwo peptides related to locust adipokinetic hormone and crustacean red pigment concentrating hormone were isolated by high performance liquid chromatography from the cicadas Cacama valavata and Diceroprocta semicincta. Both species have the same peptides. The structure of one of the peptides is pGlu‐Val‐Asn‐Phe‐Ser‐Pro‐Ser‐Trp‐Gly‐Asn‐amide. The mass spectrum, amino acid composition, and amino acid sequence of the other peptide suggest that it is almost identical to the first peptide. However, the exact nature of the difference between the two peptides could not be determined. © 1995 Wiley‐Liss, Inc.
Development of a recombinant baculovirus expressing a modified juvenile hormone esterase with potential for insect control
Authors: Bonning B. C. , Hoover K. , Booth T. F. , Duffey S. , Hammock B. D. 
Published: February 2005

AbstractBaculovirus insecticides are receiving renewed attention as insect pest control agents following the development of fast‐acting recombinant baculoviruses. Here we report on the construction and biological activity of a recombinant baculovirus derived from the nuclear polyhedrosis virus of Autographa californica which expresses a modified form of juvenile hormone esterase (JHE). The serine at the catalytic site of the JHE has been mutated to a glycine residue so that the protein does not degrade JH. The recombinant baculovirus expressing this modified form of JHE, named AcJHE‐SG, has enhanced activity against lepidopteran larvae. Lethal times of the recombinant are 20 to 30% lower than for the wild type virus, and a 66% reduction in feeding damage caused by infected larvae is observed. This result is comparable to the best recombinant baculovirus developed to date, AcAaIT, which expresses an insect‐selective scorpion toxin. The potential of these recombinant viruses for commercialization as insecticides is discussed. Bioassays of AcJHE‐SG in conjunction with anti‐JH agents indicate that the virus is not killing by an anti‐JH mechanism. Larvae apparently die from contraction‐paralysis, or disruption of the normal sequence of events at the molt. © 1995 Wiley‐Liss, Inc.
Pathway and regulation of JHIII‐bisepoxide biosynthesis in adult Drosophila melanogaster corpus allatum
Authors: Moshitzky Pnina , Applebaum Shalom W. 
Published: February 2005

AbstractAdult female Drosophila melanogaster corpus allatum (CA) synthesize JHB3 from endogenous and exogenous precursors in vitro. We present evidence supporting the thesis that biosynthesis proceeds from precursor FA via initial epoxidation and terminal methylation on the basis of the following: (1) Methyl farnesoate is not epoxidized to JHIII or JHB3; (2) Authentic JHIII is not epoxidized to JHB3; and (3) FABE is markedly metabolized to JHB3. Cerebral allatostatic factors act at some stage subsequent to FA and this precursor is not normally rate‐limiting. Additionally, neural inhibition from the brain acts at some biosynthetic step prior to FA. © 1995 Wiley‐Liss, Inc.
Loading of lipophorin particles with phospholipids at the midgut of Rhodnius prolixus
Authors: Atella Geórgia C. , Gondim Katia C. , Masuda Hatisaburo 
Published: February 2005

Abstract32P‐Labelled midguts (32P‐midguts) of Rhodnius prolixus females were incubated in the presence of nonradioactive purified lipophorin and the release of radioactivity to the medium was analysed. The radioactivity found in the medium was associated with lipophorin phospholipids. When the 32P‐midguts were incubated in the absence of lipophorin, no 32P‐phospholipids were found in the medium. Comparative analysis by thin‐layer chromatography of 32P‐phospholipids derived from metabolically labelled 32P‐midgut or lipophorin particles after incubation with 32P‐midgut showed some differences, revealing a possible selectivity in the process of phospholipids transfer. The transfer of phospholipids to lipophorin was linear with time up to 45 min, was saturable with respect to the concentration of lipophorin, and was half‐maximal at about 5 mg/ml. The binding of 32P‐lipophorin to the midgut at O°C reached the equilibrium at about 1 h of incubation. The binding of 32P‐lipophorin was inhibited by an excess of nonradioactive lipophorin, which suggests a specific receptor for lipophorin. The capacity of midguts and fat bodies to transfer phospholipids to lipophorin varied during the days following the meal. When lipophorin enzymatically depleted of phospholipids by treatment with phospholipase A2 was incubated with 32P‐midguts, the same amount of phospholipids was transferred, indicating a net gain of phospholipids by the particle. © 1995 Wiley‐Liss, Inc.
Biochemical and metabolic alterations in Acyrthosiphon pisum parasitized by Aphidius ervi
Authors: Pennacchio F. , Digilio M. C. , Tremblay E. 
Published: February 2005

AbstractBiochemical and metabolic alterations in Acyrthosiphon pisum (Harris) (Homoptera: Aphididae) parasitized by the endophagous Aphidius ervi Haliday (Hymenoptera: Braconidae) are reported. Total ecdysteroid titer was determined by radioimmunoassay. The hemolymph levels of acylglycerols and proteins were assessed with an enzymatic method and Bradford's method, respectively. Alterations of the electrophoretic pattern of host hemolymph proteins were assessed by SDS‐PAGE. Analyses were carried out on hosts parasitized as 1st instars, as well as on hosts which were parasitized later, as 3rd or 4th instars. Parasitism did not significantly alter the ecdysteroid titer of pre‐adult stages when parasitized as 3rd instars. In contrast, the ecdysteroid titer in developmentally arrested 4th instars of A. pisum, previously parasitized as 1st instars, was significantly lower than in the case of synchronous nonparasitized controls. Ecdysteroids were detected also in adult aphids, which, when previously parasitized as 3rd instars, showed a precocious end of reproductive activity associated with a hormonal titer that was significantly lower than in actively reproducing nonparasitized controls of the same age. Acylglycerol and protein titers were significantly higher in the hemolymph of both early and late parasitized hosts, 5–6 days after parasitoid oviposition. SDS‐PAGE analysis of hemolymph collected 5 days after parasitization revealed the presence of both upregulated proteins and of parasitoid‐specific proteins. The observed biochemical changes in parasitized hosts were synchronized with the major part of parasitoid larval growth and, apparently, strictly related to parasitic castration of the host. The role and importance of host regulation factors controlling these biochemical and developmental alterations in parasitized pea aphids are discussed. © 1995 Wiley‐Liss, Inc.
Anatomic variants of the celiac, superior mesenteric, and inferior mesenteric arteries and their clinical relevance
Authors: Nelson Thomas M. , Pollak Raymond , Jonasson Olga , Abcarian Herand 
Published: February 2005

AbstractA thorough knowledge of the anatomy of the celiac, superior mesenteric, and inferior mesenteric arteries and their variants is necessary to accomplish a successful, uncomplicated abdominal operation. We examined the anatomy of these arteries in situ in 50 adult cadavers. The classic anatomic description of the celiac, superior mesenteric, and inferior mesenteric arteries was each confirmed in only 24%, 22%, and 16% of the cadavers, respectively. This infrequent occurrence of the textbook picture was due to the presence of one or more variants in 94% resulting from differences in arterial origin and spatial relationship. A left hepatic artery of left gastric artery origin was found in 20%. A right or common hepatic artery of superior mesenteric artery origin was observed in 14% and 6%, respectively. Of equal frequency to the classic pattern of the superior mesenteric artery was that in which the ileocolic artery arose separately and the right and middle colic arteries arose via a common trunk. The most common pattern of the inferior mesenteric artery was a left colic and a sigmoid artery arising from a common trunk with a second sigmoid artery from the inferior mesenteric artery in 28%. The embryologic basis, frequency in the literature, and clinical relevance of these variants are discussed.
The levator ani muscle and the nerve supply of its puborectalis component
Authors: Roberts W. H. , Harrison C. W. , Mitchell D. A. , Fischer H. F. 
Published: February 2005

AbstractThis study of 50 embalmed and 4 unembalmed cadavers was undertaken to try to better understand the rationale for the varied descriptions of the levator ani muscle and its components. Our findings are in harmony with those which have determined M. puborectalis to be the caudal component of the levator ani and to have superior and inferior laminae. The inferior lamina contributes significantly to the mass of the puborectalis, forming the major part of its so‐called sling component that angulates the anorectal junction. The more superficial of the anterior fibers of both the M. pubococcygeus and M. puborectalis insert prerectally and contribute to what is called M. levator prostatae (pubovaginalis). Their fused borders bound the levator (urogenital) hiatus. The deeper fibers insert into the posterolateral wall of the vagina in the female. Both M. pubococcygeus and M. puborectalis also insert between the Ms. sphincter ani externus and internus, and both contribute to the postanal levator plate. The nerve supply of M. puborectalis is from the nerve to the levator ani (S 3,4) on its superior aspect, but it frequently receives an auxiliary supply from the inferior rectal and perineal branches of the pudendal nerve on its inferior aspect. The surgical significance of M. levator ani is commented on.
Variations in the facial muscles at the angle of the mouth
Authors: Shimada Kazuyuki , Gasser Raymond F. 
Published: February 2005

AbstractThe Latin term modiolus literally means “the nave of a wheel” and in dentistry refers to the point lateral to the angle of the mouth where several facial muscles converge. It has been described as coinciding with a muscular or tendinous node in the cheek and is considered to be important clinically. The facial muscles that insert in the vicinity of the mouth angle are the levator anguli oris, zygomaticus major, risorius, buccinator, and depressor anguli oris. The arrangement of these muscles in relation to the angle of the mouth was studied in 147 cadavers (279 sides) of the Mongoloid (Japanese) and Caucasian races. Considerable variation in the pattern of convergence was found. The variations were classified into three types as follows. Type A: location of the muscle convergence was lateral to the angle of the mouth. Type B: convergent area was located above the angle. Type C: convergent area was located below the angle. When the two races were considered together type C occurred most frequently (42.3%) followed closely by type B (41.2%). The arrangement described in textbooks (type A) occurred least frequently (16.5%). The frequency of appearance of convergent types according to race also is given. The gross observations do not support the existence of a nodular modiolus. In addition, the muscles that are supposed to contribute to the nodule usually do not converge lateral to the mouth angle but rather converge either above or below the angle.
“O death, where is thy sting?” Historical perspectives on the relationship of human postmortem anatomical dissection to medical education and care
Authors: Rodning Charles B. 
Published: February 2005

AbstractFrom an historical perspective, great intellectual effort and struggle were required to secure the privilege of human postmortem anatomical dissection. It represents one expression of the validity and value of the patient‐physician relationship. The latter contributes to the welfare of mankind, if through that involvement the knowledge and wisdom of each is enhanced. “… Death rejoices to come to the aid of life” only if patients and physicians are committed to the educational and functional value of postmortem analysis, organ/tissue donation, and cadaveric anatomical dissection. Physicians must be willing to communicate to the individuals they encounter the usefulness of these opportunities for the continued enhancement of patient care and medical science. I would argue that it should be perceived as an expression of an interdependence among all sentient beings, and as such should be promoted as the zeitgeist of all interpersonal relationships within contemporary society.
Distribution of antral G‐cells in relation to the parietal cells of the stomach and anatomical boundaries
Authors: Naik K. S. , Lagopoulos M. , Primrose J. N. 
Published: February 2005

AbstractPrevious studies involving the mapping of antral G‐cells have had little significance because the techniques involved have been tedious, inaccurate, and have concentrated on pathological material, without establishing normal antral anatomy or physiology. We describe a new, reproducible technique for the accurate mapping of antral G‐cells, which shows their relationship to the parietal cell mass and the macroscopic antrum‐corpus boundary.The antrum of 20 normal, “fresh,” postmortem human stomachs was examined by cutting 4–8 longitudinal strips. The macroscopic antrum‐corpus boundary (nerve of Latarjet) was identified. Serial section were stained for parietal and G‐cells to define the microscopic antrum‐corpus boundary.In 4 stomachs, the parietal cells extended to the pylorus. In these, the G‐cells were sparse and the antrum as defined by the G‐cells was significantly smaller (P<0.01). The G‐cell boundary correlated better with the macroscopic boundary than did the parietal cell boundary.This study provides a basis for future quantitative studies on parietal and G‐cells in the antrum which should be defined according to both G‐cells and parietal cells. Patients with “acid antra” appear to have reduced number of antral G‐cells and this may have practical significance for patients undergoing duodenal ulcer surgery.
Gracilis muscle anatomy as related to function of a free functioning muscle transplant
Authors: McKee N. H. , Fish J. S. , Manktelow R. T. , McAvoy G. V. , Young S. , Zuker R. M. 
Published: February 2005

AbstractThe purpose of this study was to establish the potential of the gracilis muscle to provide separate but controlled movement (e.g., independent finger flexion) when used as a free muscle transfer. The intramuscular neurovascular anatomy was studied in cadavers and in vitro. Through injection, dissection, and stimulation studies, it has been established that the distal gracilis can be separated longitudinally into at least two viable parts with independent neural control. This potential has been realized in ten clinical cases in which some separation of thumb and finger function has been achieved.
Transposition of the viscera: A review
Authors: Brassett Cecilia , Ellis Harold 
Published: February 2005

AbstractSitus inversus and its associated syndromes have fascinated anatomists, embryologists, and clinicians for centuries. However, the embryogenesis and mode of inheritance of situs inversus have remained ill‐understood. In this review, we summarize the current knowledge regarding etiology and genetics, discuss the diagnostic features which may be clinically useful in identifying asymptomatic subjects, and outline some important aspects in the management of patients with visceral transposition and concomitant disease. The relevance of pre‐ and neonatal diagnosis of the condition is also evaluated. We conclude with some data on the incidence of situs inversus in the East Anglian region of England.
Prospects for human digit regeneration
Authors: McLachlan John C. , Usman Tamoor 
Published: February 2005

AbstractThe phenomenon of limb regeneration is briefly described, and factors empirically known to enhance regeneration are reviewed. Regeneration is compared to the initial development of the limb, with which it shares many similarities. Recent advances in understanding of the control mechanisms underlying regeneration are described; in particular, the role of retinoids, and their relationship with homeobox‐containing genes are considered. The long‐term prospects of inducing regeneration in human amputees are considered, and a cautious “thumbs up” is given to this notion, at least in a limited form.