bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mechanisms underlying the effects of amphetamine on particulate PKC activity
Authors: Giambalvo Cecilia T. 
Published: November 2003

AbstractAmphetamine stimulates particulate protein kinase C (PKC) activity that is associated with the outward‐transport of dopamine (DA) (Giambalvo [2003] Synapse 49:125–133). This stimulatory effect requires intracellular calcium ([Ca]i) and endogenous DA and when DA release is diminished, the inward‐transport of amphetamine inhibits PKC activity. This study examines the mechanisms involved. It was found that synaptoneurosomes incubated with amphetamine showed a dose‐dependent increase in phospholipase C and A2 activities. Furthermore, pretreatments with the phospholipase C inhibitor D609 or the phospholipase A2 inhibitors quinacrine or p‐bromophenacylbromide attenuated the amphetamine‐induced increase in PKC activity. This suggests that both phospholipases were essential for the amphetamine‐induced increase in PKC activity. The Na/Ca antiporter was also involved, since pretreatment with amiloride or benzamil attenuated the amphetamine‐induced increase in PKC activity. Since these drugs by themselves increased PKC activity, the return to basal activity after addition of amphetamine suggests that, in the absence of Na/Ca exchange, amphetamine had an inhibitory effect on PKC activity. This inhibitory effect might be due to the activation of phospholipase A2 through an increase in intracellular pH induced by amphetamine. This was supported by the finding that pretreatment with dimethylamiloride, an inhibitor of the Na/H antiporter that increases intracellular [H+], attenuated the effects of amphetamine on PKC activity. Other drugs that decrease intracellular [H+] (ammonia, monensin) also inhibited PKC activity without Ca. In contrast to amphetamine, monensin had no effect on PKC activity with Ca. This could be related to its large differential effects on phospholipase A2 vs. phospholipase C activity. Thus, the monensin‐mediated decrease in PKC activity seen without Ca was partially attenuated by pretreatment with quinacrine. Furthermore, when Na/Ca antiporter was inhibited with benzamil, monensin inhibited PKC activity. These results suggest that amphetamine, as well as monensin, may have dual effects on PKC activity, a Ca‐dependent stimulatory effect via phospholipase C, and an inhibitory effect via phospholipase A2. Synapse 51:128–139, 2004. © 2003 Wiley‐Liss, Inc.
Morphine inhibits glutamate exocytosis from rat cerebral cortex nerve terminals (synaptosomes) by reducing Ca2+ influx
Authors: Yang Tsung‐Tsair , Hung Chi‐Feng , Lee Yih‐Jing , Su Ming‐Jai , Wang Su‐Jane 
Published: November 2003

AbstractMorphine, a μ‐opioid agonist, suppressed the Ca2+‐dependent release of glutamate that was evoked by exposing cerebrocortical synaptosomes to the potassium channel blocker 4‐aminopyridine. The presynaptic inhibition produced by morphine was concentration‐dependent and blocked by the nonselective opioid receptor antagonist naloxone. As determined by examining the mechanism of μ‐opioid receptor‐mediated inhibition of glutamate release, morphine caused a significant reduction in 4‐aminopyridine‐evoked increase in the cytoplasmic free Ca2+ concentration ([Ca2+]c), but failed to alter both 4‐aminopyridine‐evoked depolarization of the synaptosomal plasma membrane potential and Ca2+ ionophore (ionomycin)‐induced glutamate release. In addition, morphine was not capable of producing further inhibition on 4AP‐evoked glutamate release in synaptosomes pretreated with the cannabinoid CB1 receptor agonist WIN 55212‐2, which has been shown to depress glutamate release through a suppression of presynaptic voltage‐dependent Ca2+ channel activity. These data suggest that morphine exerts its inhibitory effect presynaptically, likely through the reduction of Ca2+ influx into nerve terminals, and thereby inhibits the release of glutamate in the cerebral cortex. This may therefore indicate that μ‐opioid receptor agonists have neuroprotective properties, especially in the excessive glutamate release that occurs under certain pathological conditions. Synapse 51:83–90, 2004. © 2003 Wiley‐Liss, Inc.
Sclerosing stromal tumor of the ovary: color Doppler findings
Authors: Deval B. , Rafii A. , Darai E. , Hugol D. , Buy J. N. 
Published: November 2003

AbstractThe sclerosing stromal tumor (SST) of the ovary is a distinct benign neoplasm that differs from fibromas, thecomas, luteinized tumors and lipoid cell tumors. It accounts for 6% of ovarian stromal tumors and tends to occur at an earlier age. On gray‐scale ultrasound examination, SSTs of the ovary are solid or cystic and multilocular. We describe here, we believe for the first time, the findings on color Doppler imaging of an SST of the ovary. A 29‐year‐old woman presented with an organic ovarian mass. She underwent a transvaginal ultrasound examination that revealed an echogenic cyst with acoustic shadowing. Color Doppler demonstrated marked peripheral vascularization. Findings on computed tomography and magnetic resonance imaging strongly suggested the preoperative diagnosis of SST of the ovary, which was confirmed at pathology. Association of an echogenic ovarian mass with acoustic shadowing and a high degree of peripheral vascularization may strongly suggest the diagnosis of SST of the ovary. Copyright © 2003 ISUOG. Published by John Wiley & Sons, Ltd.
Measurement of perifollicular blood flow of the dominant preovulatory follicle using three‐dimensional power Doppler
Authors: Vlaisavljević V. , Reljič M. , Gavrić Lovrec V. , Zazula D. , Sergent N. 
Published: November 2003

AbstractObjectiveTo establish whether we might predict the outcome of unstimulated in‐vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) cycles with quantitative indices of perifollicular blood flow assessed with three‐dimensional (3D) reconstruction of power Doppler images.MethodsThis prospective study included an analysis of 52 unstimulated cycles. Color and power Doppler ultrasound examinations of a single dominant preovulatory follicle were performed on the day of oocyte pick‐up. With 3D reconstruction and processing, quantitative indices were obtained i.e. the percentage of volume showing a flow signal (VFS) inside a 5‐mm capsule of perifollicular tissue and the percentage of VFS of each of the three largest vessels in this capsule. These indices as well as pulsed Doppler indices were compared between the groups of cycles with different outcomes using a one‐way ANOVA test.ResultsIn nine cycles no oocyte was retrieved (Group A), in seven cycles no fertilization occurred (Group B) and in 30 cycles no implantation occurred (Group C). Six cycles resulted in pregnancy (Group D). There were no statistically significant differences in pulsed and power Doppler indices between these groups. However, the percentage of VFS in the capsule was higher than average in cycles with implantation (19.22 ± 16.82 vs. 12.42 ± 8.89, NS) and the percentage of VFS in the main vessel exhibited lower than average values in cycles with implantation (20.66 ± 10.05 vs. 39.84 ± 20.15), but only reached borderline statistical significance (F = 2.457, P = 0.074).ConclusionIt can be hypothesized that the follicles containing oocytes able to produce a pregnancy have a distinctive and more uniform perifollicular vascular network. Copyright © 2003 ISUOG. Published by John Wiley & Sons, Ltd.
Prenatal ultrasound findings in complete trisomy 9
Authors: Sepulveda W. , Wimalasundera R. C. , Taylor M. J. O. , Blunt S. , Be C. , De La fuente S. 
Published: November 2003

AbstractObjectiveTo report on the prenatal ultrasound findings associated with complete trisomy 9.MethodsCases of complete trisomy 9 diagnosed prenatally were identified by reviewing the reports from two large cytogenetics laboratories serving tertiary referral centers for prenatal diagnosis. Information on prenatal ultrasound findings and outcome was obtained in all cases.ResultsNine cases of complete trisomy 9 were identified. The diagnosis was made in the first trimester in four cases, in the second trimester in three and in the third trimester in two. Two fetuses underwent first‐trimester ultrasound screening for aneuploidy and the nuchal translucency thickness was increased in both. All five fetuses detected in the second and third trimesters had several fetal anomalies including Dandy–Walker malformation in four cases, facial dysmorphism in four, genitourinary anomalies in three, congenital heart defects in three, ventriculomegaly in three, abnormal hands in two and megacisterna magna in one. Four fetuses were growth‐restricted at the time of ultrasound evaluation. However, the two cases diagnosed in the third trimester had routine second‐trimester anomaly scans reported as normal. There were no survivors in this series.ConclusionFetuses with complete trisomy 9 have multiple anomalies that can be readily detected prenatally by ultrasound. These mainly include, but are not restricted to, craniofacial, cardiovascular, musculoskeletal and genitourinary malformations. However, findings can be subtle and therefore missed at the routine second‐trimester scan. Copyright © 2003 ISUOG. Published by John Wiley & Sons, Ltd.
Dynamic free‐hand three‐dimensional fetal echocardiography gated by cardiotocography
Authors: Herberg U. , Goldberg H. , Breuer J. 
Published: November 2003

AbstractObjectiveTo evaluate the clinical feasibility of conventional cardiotocography (CTG) as a cardiac cycle triggering signal for three‐dimensional (3D) fetal echocardiography.MethodFree‐hand 3D echocardiography was performed on a total of 25 fetuses with and without congenital heart disease at various gestational ages (mean, 29 weeks; range, 19–35 weeks). Simultaneously, online CTG was used for time gating. Gray‐scale and color Doppler dynamic 3D displays, as well as multiplanar views, were assessed for their ability to depict the cardiac morphology and correct cardiac gating.ResultsValid CTG‐based trigger signals could be obtained in 24 of the 25 fetuses. Correct cardiac gating was achieved in 101 of the 111 (91%) 3D datasets. Color Doppler imaging of blood flow in four dimensions was possible in 34 of 36 (94%) datasets. Reconstructed 3D and multiplanar views provided additional views not available in two‐dimensional (2D) imaging. Acoustic interference between the CTG transducer and echotransducer could be reduced by the use of a high‐frequency echotransducer, second‐harmonic frequency imaging and appropriate positioning of the two transducers. Imaging quality was highly dependent on the quality of 2D images and random motion artifacts.ConclusionsCTG can be used as an online gating source for dynamic 3D fetal echocardiography. Copyright © 2003 ISUOG. Published by John Wiley & Sons, Ltd.
Prenatal diagnosis of cardiosplenic syndromes: a 10‐year experience
Authors: Berg C. , Geipel A. , Smrcek J. , Krapp M. , Germer U. , Kohl T. , Gembruch U. , Baschat A. A. 
Published: November 2003

AbstractObjectiveTo assess the accuracy of fetal echocardiography in the prenatal diagnosis of cardiosplenic syndromes and the spectrum of associated anomalies.MethodsThis was a retrospective survey of fetuses in our databases over a period of 10 years with postnatally confirmed prenatal diagnosis of cardiosplenic syndromes.ResultsIn 32 of 35 fetuses the prenatal diagnosis of cardiosplenic syndromes was confirmed postpartum. Twenty‐two fetuses had left isomerism. Their main prenatal ultrasound features were interrupted inferior vena cava (n = 21), complete atrioventricular septal defect (n = 15), viscerocardiac heterotaxy (n = 15), persistent bradyarrhythmia (n = 12) and fetal hydrops or nuchal edema (n = 12). Twelve pregnancies were terminated, two fetuses were stillborn and eight infants survived. Ten fetuses had right isomerism. Their main sonographic features were juxtaposition of the descending aorta and inferior vena cava (n = 7), complete atrioventricular septal defect (n = 7), left persistent superior vena cava (n = 6) and viscerocardiac heterotaxy (n = 6). In this group there was one stillbirth, five infant deaths and four survivors. The overall survival rate and spectrum of other cardiac malformations were similar between the two groups. Prenatal diagnosis of other visceral features of cardiosplenic syndromes was inconsistent.ConclusionCardiosplenic syndromes can be diagnosed with high accuracy by prenatal sonography. A diagnosis of left isomerism should be strongly suggested in the presence of a combination of at least two of the following: (1) complete atrioventricular septal defect or other structural heart disease; (2) interruption of inferior vena cava with azygos continuation; (3) early fetal heart block; (4) viscerocardiac heterotaxy. Right isomerism should be suspected in the presence of a combination of at least two of the following: (1) structural heart disease, namely complete atrioventricular septal defect; (2) juxtaposition of inferior vena cava and descending aorta; (3) viscerocardiac heterotaxy. Copyright © 2003 ISUOG. Published by John Wiley & Sons, Ltd.
Structural and functional cardiac abnormalities identified prior to 16 weeks' gestation in fetuses with increased nuchal translucency
Authors: Lopes L. M. , Brizot M. L. , Lopes M. A. B. , Ayello V. D. , Schultz R. , Zugaib M. 
Published: November 2003

AbstractObjectiveTo determine the accuracy and practicality of fetal echocardiography in the identification of structural and functional cardiac abnormalities prior to 16 weeks' gestation in fetuses with increased nuchal translucency thickness (NT).MethodsBetween January 1996 and June 2002 early fetal echocardiography using the transvaginal route was performed at 12–16 weeks' gestation on 275 fetuses with increased NT. The abnormal cardiac findings were classified as either structural (congenital heart defects) or functional, defined as transient phenomena which might later disappear, such as isolated tricuspid regurgitation and an enlarged ascending aorta. The abnormal findings were related to pregnancy outcome, including autopsy results, karyotyping results, and late fetal and neonatal echocardiography.ResultsCardiac abnormalities were present in 61 fetuses overall (22.2%); including structural cardiac defects in 37 fetuses (13.5%) and functional abnormalities in 24 fetuses (8.7%). Structural cardiac abnormalities were associated with abnormal karyotype in 24 fetuses and normal karyotype in 13 fetuses. Of the 24 fetuses with functional cardiac abnormalities, 2 (8.3%) had isolated tricuspid regurgitation and 22 (91.7%) had enlarged ascending aorta. Abnormal karyotype was present in this group in 4 cases (16.7%).ConclusionIncreased NT can be used to define a high‐risk group that should receive specialized early fetal echocardiography. This is a reliable technique with great potential for the diagnosis of both structural and functional cardiac abnormalities. Copyright © 2003 ISUOG. Published by John Wiley & Sons, Ltd.
DNA sequence of the mat2,3 region of Schizosaccharomyces kambucha shares high homology with the corresponding sequence from Sz. pombe
Authors: Singh Gurjeet , Klar Amar J. S. 
Published: November 2003

AbstractTo define conserved sequences for mat1 imprinting and silencing of the mat2,3 region of Schizosaccharomyces pombe, we determined the DNA sequence of the cognate region (mat2,3 region) of another fission yeast, Sz. kambucha, a yeast species isolated from Kambucha tea mix. The entire mat2,3 region shows more than 98% identity between the two species. Sequence similarity is even higher (99.3%) for mating‐type cassettes; deduced amino acid sequences of three of the four Mat peptides (Pi, Pc and Mi) are identical between the two species, while the fourth (Mc) has a single amino acid polymorphism. Comparison of the sequence motif of the imprint site essential for mat1 switching shows that mat‐P of Sz. kambucha has a sequence identical to the conserved motif present in Sz. pombe. However, this sequence motif of nine bases differs by one base for mat‐M of Sz. kambucha. The sequence of the K region shows about 98% identity between the two species, with the cenH region showing 98.3% homology. Thus, the arrangement of the mat2,3 region in both yeasts is conserved and shows 1–2% nucleotide sequence variation throughout the region. The DNA sequence of the mat2,3 region from Sz. kambucha has been submitted to GenBank under Accession No. AY271822. Copyright © 2003 John Wiley & Sons, Ltd.
Cloning and disruption of the PpURA5 gene and construction of a set of integration vectors for the stable genetic modification of Pichia pastoris
Authors: Nett Juergen H. , Gerngross Tillman U. 
Published: November 2003

AbstractA pair of degenerate primers was used for amplification and cloning of a DNA fragment containing parts of the P. pastoris URA5 and SEC65 genes. Using additional information from a partial genomic sequence of P. pastoris, we cloned and sequenced a 1.9 kb chromosomal fragment containing the complete orotate‐phosphoribosyltransferase‐encoding URA5 gene. A disruption cassette was constructed by replacing a small part of the open reading frame with a kanamycin‐resistance gene. The P. pastoris wild‐type strain NRRL Y‐11430 was transformed with the disruption cassette and an ura5 auxotrophic strain was identified. To generate marker constructs that can be reused in successive transformations of a single strain, we constructed two lacZ–PpURA3–lacZ and lacZ–PpURA5–lacZ cassettes and used them to disrupt PpOCH1. The PpURA3 and PpURA5 genes in the disruptants were then successfully recycled by selecting for resistance to 5′‐fluoro‐orotic acid. We also assembled a set of modular plasmids that can be used for the stable genetic modification of P. pastoris via a double cross‐over event. The sequence presented here has been submitted to the EMBL data library under Accession No. AY303544. Copyright © 2003 John Wiley & Sons, Ltd.
Potential mechanisms of avian sex manipulation
Authors: PIKE THOMAS W. , PETRIE MARION 
Published: November 2003

ABSTRACTThe aim of this review is to consider the potential mechanisms birds may use to manipulate the sex of their progeny, and the possible role played by maternal hormones. Over the past few years there has been a surge of reports documenting the ability of birds to overcome the rigid process of chromosomal sex determination. However, while many of these studies leave us in little doubt that mechanisms allowing birds to achieve this feat do exist, we are only left with tantalizing suggestions as to what the precise mechanism or mechanisms may be. The quest to elucidate them is made no easier by the fact that a variety of environmental conditions have been invoked in relation to sex manipulation, and there is no reason to assume that any particular mechanism is conserved among the vast diversity of species that can achieve it. In fact, a number of intriguing proposals have been put forward. We begin by briefly reviewing some of the most recent examples of this phenomenon before highlighting some of the more plausible mechanisms, drawing on recent work from a variety of taxa. In birds, females are the heterogametic sex and so non‐Mendelian segregation of the sex chromosomes could conceivably be under maternal control. Another suggestion is that follicles that ultimately give rise to males and females grow at different rates. Alternatively, the female might selectively abort embryos or‘dump lay’eggs of a particular sex, deny certain ova a chance of ovulation, fertilization or zygote formation, or selectively provision eggs so that there is sex‐specific embryonic mortality. The ideas outlined in this review provide good starting points for testing the hypotheses both experimentally (behaviourally and physiologically) and theoretically.
The use of multiple cues in mate choice
Authors: CANDOLIN ULRIKA 
Published: November 2003

ABSTRACTAn increasing number of studies find females to base their mate choice on several cues. Why this occurs is debated and many different hypotheses have been proposed. Here I review the hypotheses and the evidence in favour of them. At the same time I provide a new categorisation based on the adaptiveness of the preferences and the information content of the cues. A few comparative and empirical studies suggest that most multiple cues are Fisherian attractiveness cues or uninformative cues that occur alongside a viability indicator and facilitate detection, improve signal reception, or are remnants from past selection pressures. However, much evidence exists for multiple cues providing additional information and serving as multiple messages that either indicate general mate quality or enable females that differ in mate preferences to choose the most suitable male. Less evidence exists for multiple cues serving as back‐up signals. The importance of receiver psychology, multiple sensory environments and signal interaction in the evolution of multiple cues and preferences has received surprisingly little attention but may be of crucial importance. Similarly, sexual conflict has been proposed to result in maladaptive preferences for manipulative cues, and in neutral preferences for threshold cues, but no reliable evidence exists so far. An important factor in the evolution of multiple preferences is the cost of using additional cues. Most theoretical work assumes that the cost of choice increases with the number of cues used, which restricts the conditions under which preferences for multiple cues are expected to evolve. I suggest that in contrast to this expectation, the use of multiple cues can reduce mate choice costs by decreasing the number of mates inspected more closely or the time and energy spent inspecting a set of mates. This may be one explanation for why multiple cues are more common than usually expected. Finally I discuss the consequences that the use of multiple cues may have for the process of sexual selection, the maintenance of genetic variation, and speciation.
Effect of two phenanthrene alkaloids on angiotensin II‐induced leukocyte–endothelial cell interactions in vivo
Authors: Estellés Rossana , López‐Martín Javier , Milian Lara , O'Connor José‐Enrique , Martínez‐Losa Magdalena , Cerdá‐Nicolás Miguel , Anam Edet M , Ivorra María Dolores , Issekutz Andrew C , Cortijo Julio , Morcillo Esteban J , Blázquez María Amparo , Sanz María‐Jesús 
Published: November 2003

The present study has evaluated the effect of two phenanthrene alkaloids, uvariopsine and stephenanthrine, on angiotensin II (Ang‐II)‐induced leukocyte–endothelial cell interactions in vivo and the mechanisms involved in their activity. Intravital microscopy within the rat mesenteric microcirculation was used.
A 60 min superfusion with 1 nM Ang‐II induced a significant increase in the leukocyte–endothelial cell interactions that were completely inhibited by 1 μM uvariopsine cosuperfusion. A lower dose of 0.1 μM significantly reduced Ang‐II‐induced leukocyte adhesion by 75%.
When Ang‐II was cosuperfused with 1 and 0.1 μM stephenanthrine, Ang‐II‐induced leukocyte responses were significantly diminished. A lower dose of 0.01 μM only affected Ang‐II‐induced leukocyte adhesion.
Both alkaloids inhibited Ang‐II‐induced endothelial P‐selectin upregulation and the generation of reactive oxygen species (ROS) in endothelial cells stimulated with Ang‐II, in fMLP‐stimulated human neutrophils (PMNs) and in the hypoxanthine–xanthine oxidase system. However, cyclic AMP levels in PMNs stimulated with fMLP were not affected.
Uvariopsine and stephenanthrine inhibited PAF‐induced elevations in intracellular calcium levels in PMNs (IC50 values: 15.1 and 6.1 μM respectively) and blocked the binding of [3H]PAF to these leukocytes. They also reduced PAF‐induced increases in intracellular levels of superoxide anion and hydrogen peroxide.
In conclusion, stephenanthrine and uvariopsine are potent inhibitors of Ang‐II‐induced leukocyte accumulation in vivo. This effect appears to be mediated through ROS scavenging activity and blockade of PAF receptor. Thus, they have potential therapeutic interest for the control of leukocyte recruitment that occurs in cardiovascular disease states in which Ang‐II is involved.

British Journal of Pharmacology (2003) 140, 1057–1067. doi:10.1038/sj.bjp.0705525