bluuebunny/crossref_metadata_2025_split huggingface dataset:
Uptake of high‐density lipoprotein by Y‐organs of the crab, cancer antennarius. II. formal characterization of receptor‐mediation with isolated membranes
Authors: Kang Byoung K. , Spaziani Eugene 
Published: February 2005

AbstractY‐organs are the ecdysial glands of crustaceans, responsible for synthesis and secretion of ecdysteroid hormones. For this purpose, the glands acquire cholesterol as obligate precursor entirely from circulating high‐density lipoprotein (HDL). A preceding study provided evidence for the mechanism of acquisition: Y‐organs take up cholesterol bound to HDL by an energy‐requiring process, receptor‐mediated absorptive endocytosis. The present study characterized the receptors involved utilizing isolated Y‐organ membranes. HDL binding was saturable and specific; a dissociation constant (Kd) of 1.08 × 10−7 M and a binding maximum at equilibrium (Bmax) of 70 μg HDL protein/mg membrane protein, were obtained. Binding was decreased by protease and was dependent upon calcium. Y‐organs are regulated negatively by a peptide hormone from the eystalks, molt‐inhibiting hormone (MIH). Y‐organ membranes from de‐eyestalked crabs (MIH absent) exhibited the same Kd value as membranes from intact crabs, but a Bmax 17% higher. Thus, MIH activity apparently does not change the binding affinity of HDL, but decreases the number of binding sites. These results agree with our previous findings that MIH depresses ecdysteroid synthesis in part by inhibiting cholesterol uptake. Generally, Y‐organ cells appear to contain receptors for HDL that are of high affinity and high binding capacity, similar to the characteristics reported for the binding of insect HDL (vitellogenin) to fat bodies and oocytes. © 1995 Wiley‐Liss, Inc.
Immunological studies on the developmental and chromosomal distribution of ecdysteroid receptor protein in Chironomus tentans
Authors: Wegmann Ines S. , Quack Stephanie , Spindler Klaus‐Dieter , Dorsch‐Häsler Karoline , Vögtli Martin , Lezzi Markus 
Published: February 2005

AbstractAntisera were raised against different domains of a putative ecdysteroid receptor (cEcRH) of Chironomus tentans. All the antisera reacted with a 68,000 dalton protein exhibiting DNA binding properties. Additionally, we were able to demonstrate that the antisera immunoprecipitate protein which binds a radioactively labeled ecdysteroid (Ec), i.e., [3H]ponasterone A, with high specificity. These properties indicate that the antisera recognize specifically an endogenous ecdysteroid receptor protein (cEcR) in C. tentans cells and thus are suitable for the following quantitative and qualitative immunological and immunohistochemical investigations. The cellular level of cEcR varies during development, and it is particularly low in oligopausing larvae. In polytene chromosomes of prepupal salivary glands, cEcR is located at approximately 50 transcriptionally active loci. These loci include both early ecdysteroid (Ec)‐inducible puff sites, such as the locus containing the gene coding for the homolog of the E75 protein in Drosophila melanogaster, as well as late Ec‐inducible puff‐sites. The latter group comprises a locus of a gene specifying the homolog of the D. melanogaster ultraspiracle protein. However, loci of genes coding for salivary gland secretory proteins (e.g., Balbiani ring forming chromosome regions) do not specifically react with the antisera. Thus, the developmental regulation of these genes is not directly controlled by Ec. Polytene chromosomes of oligopausing larvae show hardly any loci that contain cEcR. The few detected correspond, with few exceptions, to the most potent cEcR binding sites found in prepupae. © 1995 Wiley‐Liss, Inc.
RNA polymerases and transcriptional activity of the fat body during the final larval instar of the tobacco hornworm Manduca sexta
Authors: Sridhara S. 
Published: February 2005

AbstractThe activities of RNA polymerases I and II in the fat body of the tobacco hornworm larva increased during feeding and then declined during wandering in the fifth instar (Sridhara and Gilbert, Dev Biol 45:7–21 [1975]). RNA polymerase II activity was much higher than that of RNA polymerase I. To determine how the differences in the activities of the two enzymes and their developmental changes correlate with changes in RNA and protein, the contents of these macromolecules were determined during the same period. RNA and protein increased by about 8 to 10‐fold during the feeding period. Activities of RNA polymerases I and II in nuclei, as well as those present in “free” (not transcribing) and “engaged” (transcribing) pools, were measured. Incorporation of labeled uridine into RNA by fat body cells in vitro was correlated to nuclear enzyme activities. The amounts of RNA polymerases I, II, and III were determined by the application of an ELISA with subunit‐specific monoclonal antibodies. Results showed that even though the in vitro activity of RNA polymerase II and its amounts are higher than those of RNA polymerase I and III, rRNA and tRNA syntheses predominated over mRNA synthesis in vivo. The activities and amounts of RNA polymerase II in the “free” pool were higher than those for RNA polymerase I. The “free” pools of the two enzymes increased as the larva progressed through the fifth instar. There appears to be little correlation between RNA polymerase activities and RNA synthesis during wandering, as RNA synthesis by the tissue and nuclear RNA polymerase activities declined faster than the amounts of the enzymes. The amount of RNA remained fairly steady during the same period. 20‐hydroxyecdysone did not affect either the RNA polymerase activities or RNA synthesis of the fat body cultured in vitro. © 1995 Wiley‐Liss, Inc.
Corpora allata of the larval tobacco hornworm contain a calcium/calmodulin‐sensitive adenylyl cyclase
Authors: Granger Noelle A. , Allen L. Gregory , Sturgis Sheri L. , Combest Wendell , Ebersohl Richard 
Published: February 2005

AbstractAn assay was developed with which to study basic characteristics of an adenylyl cyclase in the corpora allata (CA) of the tobacco hornworm, Manduca sexta. The assay used glands collected and frozen at −80°C, to circumvent the problem of tissue availability. With this protocol for storage of tissue, less than 25% of the enzyme activity in fresh tissue was lost. Substances such as sodium fluoride (NaF) and Gpp(NH)p (a non‐hydrolyzable GTP analog), which typically stimulate the adenylyl cyclases in other insect tissues, increased enzyme activity several‐fold. There was a progressive decrease in the capacity of the CA adenylyl cyclase to be stimulated by NaF during the fifth stadium, suggesting a possible developmental change in the capacity of the associated G protein to be stimulated by NaF. The calcium/calmodulin (CaM) dependence of adenylyl cyclase activity was also investigated. The results demonstrated that addition of up to 10−4 M calcium to assays of enzyme activity in whole gland homogenates of both larval (day O) and prepupal (day 6) CA resulted in only a slight increase in the activity of the enzyme over basal rates in the presence of the calcium chelator EGTA. However, addition of as little as 5 m̈M CaM in the presence of 10−4 to 10−3 M calcium increased adenylyl cyclase activity three to five‐fold. A similar stimulation was obtained with washed membrane preparations of day 0 and day 6 glands, but required a substantially higher concentration of CaM. Results demonstrated that the CA possess a calcium/CaM‐dependent adenylyl cyclase from day 0 through day 6. A preliminary investigation of the effect of two biogenic amines on the CA adenylyl cyclase revealed that enzyme activity was not affected by octopamine, but a stage‐specific effect was obtained with dopamine. Concentrations of 10−6 and 10−7 M stimulated enzyme activity in hornogenates of day 0 glands but inhibited activity in homogenates of day 6 CA. © 1995 Wiley‐Liss, Inc.
Comparison of ecdysteroid production in Drosophila and Manduca: Pharmacology and cross‐species neural reactivity
Authors: Henrich Vincent C. 
Published: February 2005

AbstractIn both Manduca sexta and Drosophila melanogaster, metamorphic events are driven by ecdysteroids whose production in prothoracic gland (PGs) is stimulated periodically by neural factors. Differences in the life cycle of moths and flies have made it difficult to compare the regulation of ecdysteroid biosynthesis in these two species.As in Manduca, at least two neural factors in the larval Drosophila BVG complex were separable by molecular weight, and they stimulated increased ecdysteroid biosynthesis from the ring gland, a composite organ that includes PG cells. Drosophila neural extracts accelerated ecdysteroid biosynthesis in Manduca PGs and, conversely, partially purified Manduca PTTH preparations elevated ecdysteroid biosynthesis in Drosophila ring glands, suggesting that the two species may share structurally similar prothoracicotropic factors. Drosophila ring glands required the presence of calcium ions to respond to neural extracts, but the phosphodiesterase inhibitor MIX and cAMP analogues exerted little, if any, positive effect on production.Mean ecdysteroid production rates of BVG‐ring gland complexes taken from Drosophila larvae during various phases of the wandering period were often submaximal and highly variable, suggesting that they fluctuate widely prior to pupariation. Based on available data in Drosophila and the Manduca model for the control of ecdysteroid biosynthesis, a developmental scheme for neuroendocrine control in Drosophila is proposed. © 1995 Wiley‐Liss, Inc.
Characterization of the juvenile hormone epoxide hydrolase (JHEH) and juvenile hormone diol phosphotransferase (JHDPT) from Manduca sexta Malpighian tubules
Authors: Grieneisen Michael L. , Kieckbusch Travis D. , Mok Amy , Dorman György , Latli Bachir , Prestwich Glenn D. , Schooley David A. 
Published: February 2005

AbstractJuvenile hormone epoxide hydrolase (JHEH) and juvenile hormone diol phosphotransferase (JHDPT) were characterized from the Malpighian tubules of day 1 fifth instar Manduca sexta. An improved RP‐HPLC assay is described for the major metabolites of (10R, 11S) juvenile hormone I: diol, acid, aciddiol, and diol‐phosphate. JHEH is strictly associated with membrane fractions, while JHDPT is cytosolic. JHEH may be solubilized in active form by the nonionic detergents Thesit or MEGA‐8. Separation of Malpighian tubule cytosol proteins using preparative isoelectric focusing yields two zones which contain JHDPT activity, at pl 4.8–5.1 and 6.8–8.2. The partially purified JHDPT from either zone requires both ATP and Mg2+ for activity, so this enzyme may be formally called either ATP:juvenile hormone diol phosphotransferase or juvenile hormone diol kinase (EC 2.1.7.3.). Metabolites more polar than JH I aciddiol and JH I diol‐phosphate are generated in vivo from either [3H]JH I or [3H]JH I diol. © 1995 Wiley‐Liss, Inc.
Regulation and consequences of cellular changes in the prothoracic glands of Manduca sexta during the last larval instar: A review
Authors: Smith Wendy A. 
Published: February 2005

AbstractThe prothoracic glands of the tobacco hornworm, Manduca sexta, respond to prothoracicotropic hormone (PTTH) by a regulatory pathway involving cAMP, protein phosphorylation, protein synthesis, and enhanced secretion of ecdysteroids including ecdysone and 3‐dehydroecdysone. Recent investigations have revealed that PTTH acts by this general mechanism throughout the fifth larval instar, i.e., during the transition from larva to pupa. However, the glands undergo developmental changes in size, steroidogenic capacity, and in elements of the signalling pathway associated with synthesis, degradation, and intracellular action of cAMP. The present review describes such changes, and their possible regulation and consequences, in the general context of endocrine events underlying larval‐pupal metamorphosis during the fifth larval stage. © 1995 Wiley‐Liss, Inc.
PBAN‐induced sex pheromone biosynthesis in Heliothis peltigera: Structure, dose, and time dependent analysis
Authors: Altstein Miriam , Dunkelblum Ezra , Gabay Tal , Aziz Orna Ben , Schafler Irit , Gazit Yoav 
Published: February 2005

AbstractA structure‐activity relationship study of Hez‐PBAN was performed with respect to its pheromonotropic activity, using Heliothis peltigera as the test animal. The activity of N‐ and C‐terminally derived sequences was examined in a time‐ and dose‐dependent mode. Using a variety of Hez‐PBAN‐derived fragments at two doses (1 and 10 pmol) and at different times post‐injection (5–120 min), we were able to demonstrate that peptides lacking 12 and 16 amino acids from their N‐terminus are as potent as the full length PBAN, and that the C‐terminally derived hexapeptide was capable of stimulating sex pheromone production to a similar extent as PBAN 1–33NH2, when its activity was analyzed at shorter post‐injection times. Within the C‐terminal sequence, the amide was found to play a crucial role. In addition, it was observed that the region between amino acids 9 and 13 is important for the biological activity of the full length PBAN. The fact that the pheromonotropic activity of the hexapeptide was similar to that of the full length PBAN, under specific conditions, suggests that this sequence constitutes the biologically active site of the neuropeptide. The discovery that PBAN‐derived peptides reacted in a time‐ and dose‐dependent mode, strengthens the assumption that proteolytic enzymes interfere with the pheromonotropic activity of the PBAN‐derived fragments. The ability of a variety of peptides to stimulate sex pheromone biosynthesis suggests two possible mechanisms: (1) Existence of multiple pheromonotropic mechanisms which may be mediated by multiple PBAN receptors that are activated at different kinetics; (2) Existence of only one mechanism mediated by short C‐terminally derived peptides. In the first case, the C‐terminally derived sequences fulfill the conformational requirement of only one class of receptors, and other regions in the PBAN molecule (e.g., 9–13) fulfill the conformational requirements of a second (or other) class of receptors. In the second case, the C‐terminally derived sequence is the only conformationally important sequence, and other sequences, which were found to be essential for the biological activity, serve other non‐conformational purposes (e.g., protection against proteolytic degradation). © 1995 Wiley‐Liss, Inc.
Surgical anatomy of hepatic venous system
Authors: Ger Ralph 
Published: February 2005

AbstractSurgeons are comfortable with nearly all the intraabdominal structures except the liver. The reason for this is an unfamiliarity with the large intrahepatic venous structures. This arises because current educational methods, illustrations, and prepared casts are relatively unhelpful. The intrahepatic anatomy is best studied by specially prepared dissections that show the vascular structures, with their interrelationships, and the routes of access to these vessels. Forty formalin‐hardened livers were thus dissected. The fissures and portal and hepatic veins have been displayed to emphasize their relations to each other with a view to facilitating their exposure at surgery.
Microsurgical anatomy of the pituitary gland (hypophysis cerebri) and the sellar region. Part three: The meninges
Authors: Ouaknine Georges E. , Hardy Jules 
Published: February 2005

AbstractThe diaphragma sellae, the pituitary foramen, and the perisellar arachnoid were studied in cadaver sphenoid blocks. Special attention was paid to the dissection of the perforated arachnoid membrane (of Lilliequist). Results were compared with observations made during surgery and with data reported in the literature. The pathophysiology of the intrasellar arachnoid diverticulum, the empty sella syndrome, and the intrasellar arachnoid cyst are discussed. Precise knowledge of the microsurgical anatomy and anatomic variations of the dura mater and arachnoid is imperative for a safe trans‐sphenoidal approach to the hypophysis cerebri (pituitary gland) and transcranial approach to the sellar region.
A method for locating the external ramus of the accessory nerve in the posterior cervical triangle
Authors: Peck David , Luce Edward A. 
Published: February 2005

AbstractInjury to the external ramus of the accessory nerve during surgery in the posterior triangle of the neck results in a disfiguring and incapacitating paralysis of the trapezius. In order to avoid this, a simple method for locating the ramus was devised. In 17 cadavers the anterior border of the trapezius was palpated and the skin marked at a point 5 cm above its clavicular attachment. A second point, situated over the posterior border of the sternocleidomastoid 6.5 cm below the tip of the mastoid process was similarly marked. A line joining these two points overlies the course of the ramus. As the ramus may lie superficially in this region, the skin incision along this line was followed by blunt dissection of the underlying fascia. The ramus was thus identified at the anterior border of the trapezius 5 cm above its clavicular attachment. This method was successful in all 17 cadavers (34 exposures), even though 3 of these were very obese with short necks. Using this surface marking, injury to the external ramus of the accessory nerve in the posterior triangle can be avoided.
Clinical anatomy of the flexor hallucis brevis muscle
Authors: Ger Ralph 
Published: February 2005

AbstractUlcerative lesions of the sole of the foot are common, especially in diabetic patients. The management of these lesions, particularly when ulcerating deeply, is difficult. Recent publications describe the neurovascular supply of the sole of the foot with special reference to rotation flaps (Shaw and Hidalgo: Plast. Reconstr. Surg., 78:5, 1986; Hidalgo and Shaw: Plast. Reconstr. Surg., 78:5, 1986). However, these flaps refer to lesions of the heel and midfoot and do not describe flaps to cover the forefoot, especially the common perforating ulcers over the first metatarsophalangeal (M‐P) joint.Previously (Ger: Clin. Orthop., 175:186, 1983) muscle transposition procedures were described in which the flexor hallucis brevis (FHB) muscle was used to close a forefoot ulcer. At that time mention was made of the ability to divide the neurovascular pedicle without producing muscle necrosis and the possible routes of alternative supply were described. Since that time further dissections have been carried out and additional clinical experience has been obtained.
The effect of testicular biopsy on the regional lymph node of the testis in rats
Authors: McDonald S. W. , Scothorne R. J. 
Published: February 2005

AbstractThe immunological effects of testicular biopsy are largely unknown. This study on young adult Albino Swiss rats shows no changes in the regional testicular lymph nodes compared to those from sham‐operated controls at either 1 or 3 months after operation. The findings contrast markedly with those of vasectomy after which there are obvious histological changes in the nodes consistent with antisperm antibody formation. The difference is likely to be related to the absence of sperm granulomas or other inflammatory changes in the testis after testicular biopsy.
Sex differences in the morphology of the auricular surfaces of the human sacroiliac joint
Authors: Valojerdy M. R. , Hogg D. A. 
Published: February 2005

AbstractTo investigate sex differences in the morphology of the auricular surfaces of the human sacroiliac joint, 153 dried bone sets of unknown ages, and of Indian origin were studied, and various measurements were made of the corresponding iliac and sacral auricular surfaces. Some significant differences. The sacral and iliac auricular surfaces was larger and longer in males. The most prominent point on the ventral border of the iliac auricular surface was situated more caudally in females. The iliac angle was larger in males. The deepest point of the dorsal border of the iliac auricular surface was more caudal in females.
The transverse cervical artery: New origins and pathways
Authors: Phillips Lloyd G. 
Published: February 2005

AbstractMost areas of the body demonstrate variations in vascular pattern with regard to origin, course, and distribution. Vascular damage is especially likely if an unexpected vascular pattern occurs in a common surgical site. The supra‐clavicular region is one such site: the many types of operative procedures performed here provide ample opportunity for inadvertent discovery of such variations. Standard textbook descriptions of the subclavian artery and its proximal branches and their relationships are usually sufficient to inform the surgeon of the predominate patterns, but leave him ill‐prepared for encounters with less common varieties. Previous studies, some extensive, have detailed many of these variations, but emphasis has been placed on the vascular configurations themselves, rather than on their clinical significance. The present study first reviews the common patterns and then outlines several heretofore undescribed variations in the thyrocervical trunk‐transverse cervical artery complex encountered in 74 unilateral and 38 bilateral neck‐shoulder specimens. Specific reference is made regarding their discovery during surgical procedures.
Neuromuscular spindles relative to joint movement complexities
Authors: Buxton Donald F. , Peck David 
Published: February 2005

AbstractSmall muscles, such as those producing movements of the digits, are known to contain high densities of muscle spindles compared to larger muscles of the limb. These high densities have been associated with an increased need for proprioceptive feedback during precise manipulative movements. A recent study has indicated that spindle densities are related to muscle size rather than to functional capability. By contrast, the current study examined whether spindle numbers, actual spindle densities and relative spindle densities correlated with the complexity of joint movements in two species with different muscle sizes, human and guinea pig. Published data were used for the histological parameters of each species and measurements were made of movement range in each kinematic degree of freedom for each joint of the human and guinea pig pectoral and pelvic limbs. Muscle weights of newborn humans were 315 times greater than those of guinea pigs but joint movement complexities were almost the same in the two species and actual spindle numbers of human were only 7.3 times those of guinea pig. Joint movement complexity tended to be greatest most proximally on each limb and progressively decreased more distally. Regardless of muscle weight differences, actual spindle numbers and relative spindle densities correlated positively and significantly with joint movement complexity and actual spindle densities correlated negatively in each species. Hence muscle spindle numbers and densities around joints appear to reflect joint functional capability for appropriate proprioceptive feedback to the central nervous system in the control of joint movement.