bluuebunny/crossref_metadata_2025 huggingface dataset:
Adenosine Inhibits L‐ and N‐Type Calcium Channels in Pituitary Melanotrophs. Evidence for the Involvement of a G Protein in Calcium Channel Gating
Authors: Mei Yan Ai , Le Foll Frank , Vaudry Hubert , Cazin Lionel
Published: October 2006

It has been previously demonstrated that activation of A1 adenosine receptors in frog melanotrophs causes inhibition of spontaneous action potential discharges and alpha‐melanocyte‐stimulating hormone secretion. In the present study, we have investigated the effect of adenosine on high‐voltage‐activated (HVA) calcium currents in cultured melanotrophs, using the whole‐cell variant of the patch‐clamp technique with barium as a charge carrier. Adenosine and the specific A1 adenosine receptor agonist R‐PIA (50 μM each) produced a decrease of the amplitude of the barium current, while the selective A2 adenosine receptor agonist CGS 21680 did not affect the current. The inhibitory effect of R‐PIA was observed throughout the activation range of the current, with stronger responses at more positive potentials. R‐PIA inhibited both the L‐ and N‐type components of the current, the effect on the N‐component being two‐fold higher than on the L‐component. The inhibitory effect of R‐PIA was rendered irreversible by addition of GTPyS (100 μM) to the intracellular solution. Pre‐treatment of the cells with pertussis toxin (1 μg/ml; 12 h) totally abolished the effect of R‐PIA on the HVA calcium channels. Conversely, addition of a high concentration of cAMP (100 μM) together with the phosphodiesterase inhibitor IBMX (100 μM) to the intracellular solution did not modify the effect of R‐PIA on the current.

It is concluded that, in frog melanotrophs, adenosine induces inhibition of L‐ and N‐calcium currents and that this effect is mediated by a pertussis toxin‐sensitive G protein. Our data also indicate that the inhibitory effect of adenosine on the calcium currents is not mediated by inhibition of adenylyl cyclase.
Evidence for a Trophic Action of the Glycoprotein Hormone α‐Subunit in Rat Pituitary
Authors: Van Bael Annemie , Denef Carl
Published: October 2006

The effect of the α‐subunit of luteinizing hormone (LHα) on lactotroph growth in 14‐day‐old rat pituitary was studied in vitro using a reaggregate pituitary cell culture system. LHα significantly expanded both the total population of cells expressing prolactin mRNA and the number of [3H]thymidine incorporating prolactin mRNA expressing cells. No such effect could be elicited by LH. Both effects were inhibited by simultaneous addition of an anti‐LHα antiserum but not by normal rabbit serum. Anti‐LHα antiserum added alone to the cultures caused a small decrease in the number of prolactin mRNA expressing cells and in [3H]thymidine labelling of the latter. It is concluded that LHα may be a trophic factor of lactotrophs not only during fetal development, as suggested by others previously, but also during the rapid expansion of this cell type during postnatal life in the rat.
Corticosterone Controls lnterleukin‐1β Expression and Sickness Behavior in the Rat
Authors: Pezeshki Gita , Pohl Thomas , Schöbitz Bernd
Published: October 2006

We studied the effect of corticosterone on interleukin (IL)‐1β synthesis, body temperature, general activity, food consumption and fluid intake in rats treated with bacterial lipopolysaccharide (LPS). Radiotelemetry was used to assess body temperature and locomotor activity in combination with continuous automated recordings of feeding and drinking. This technique was developed as a novel method to identify and measure sickness behavior in rodents. The animals were (a) sham‐operated, (b) adrenalectomized or (c) sham‐operated and treated with corticosterone (10 mg/kg, subcutaneously). They were then intraperitoneally injected with vehicle or LPS at a dose (100 μg/kg) that in sham‐operated rats induced fever and anorexia, reduced spontaneous activity and increased IL1‐β mRNA in spleen and adrenals as determined by Northern blot analysis. Adrenalectomized rats produced larger amounts of splenic IL‐1β mRNA, reduced their general activity much more and developed a mild adipsia as compared with adrenal‐intact animals. Administration of corticosterone 1 h before LPS lowered the splenic IL‐1β mRNA content compared to LPS‐treated adrenal‐intact rats that did not receive corticosterone and inhibited fever and anorexia, whereas the glucocorticoid did not attenuate the endotoxin‐induced suppression of locomotor activity. Our data suggest that during inflammatory conditions body temperature, sickness behavior and the synthesis of IL‐1β are controlled by corticosterone. Different components of sickness behavior seem to be independently regulated and are under differential control by glucocorticoids.
Facilitatory Effects of Pituitary Adenylate Cyclase Activating Polypeptide (PACAP) on Neurons in the Magnocellular Portion of the Rat Hypothalamic Paraventricular Nucleus (PVN) in vitro
Authors: Uchimura Daisuke , Katafuchi Toshihiko , Hori Tetsuro , Yanaihara Noboru
Published: October 2006

To establish the role of pituitary adenylate cyclase activating polypeptide (PACAP), a member of vasoactive intestinal polypeptide (VIP) family, as a neurotransmitter/neuromodulator in the central nervous system, the effects of PACAP38, PACAP27 and VIP on the single neuron activity in the magnocellular portion of the hypothalamic paraventricular nucleus (mg.PVN) were examined in rat brain slice preparations. Extracellular recordings were made from 111 neurons in the mg.PVN, which fired spontaneously at an average rate of 1.85 ± 0.2 spikes/s (mean ± SEM). PACAP38 and PACAP27 were applied to 78 and 33 of the 111 neurons, respectively. Perfusion with PACAP38 in doses between 10 nM and 1 μM increased the firing rate of 56 (71.8%) of the 78 neurons in a dose‐dependent manner. The threshold dose of PACAP38 to excite the neurons seemed to lie below 10 nM. The application of PACAP27 (1 μM) also increased the firing rate of 19 (57.6%) of the 33 neurons tested. Eleven (52.4%) of 21 neurons which were excited by PACAP38 also showed excitation following perfusion with VIP (1 μM). The responses to PACAP38 in 12 of 20 neurons and those to VIP in 6 of 9 neurons tested were still observed in a low Ca2+ and high Mg2+ medium. Although there was no difference in the mean latency between the responses to PACAP38 (1 μM) and VIP (1μM) (2.1 ± 0.1 min and 2.4 ± 0.4 min, respectively), the duration of the PACAP38‐induced excitation (59.0 ± 5.0 min) was much longer than that of the VIP‐induced one (18.8 ± 3.1 min). The PACAP38 (30 nM)‐induced excitation was reversibly blocked by a concurrent application of PACAP5‐38 (300 nM), a PACAP receptor antagonist. While a selective VIP receptor antagonist, [Lys1, Pro2,5, Arg3,4, Tyr6]‐VIP (1μM), did not affect the excitatory responses to PACAP38 (300 nM), it completely blocked the VIP (1μM)‐induced excitation. These findings suggest that PACAP may therefore modulate the secretion of the pituitary hormones at least partly by its action on the neurons in the mg.PVN through the activation of specific receptors for PACAP.
Prostaglandin Fever in Rats Throughout the Estrous Cycle Late Pregnancy and Post Parturition
Authors: Martin Sheilagh M. , Malkinson Terrance J. , Veale Warren L. , Pittman Quentin J.
Published: October 2006

We have examined the influence of natural variations in endocrine status on the ability to generate a prostaglandin‐induced fever in virgin female, pregnant and lactating rats and compared responses to those in male rats. Endocrine status of virgin female rats was assessed from examination of vaginal smears and time of parturition noted to enable accurate dating of pre‐ and postparturient fevers. Unanesthetized rats, previously prepared with intraventricular guide cannulas and intraperitoneal telemetry thermistors, were given intraventricular injections of prostaglandin E, (2–100 ng/5 μl) and temperatures monitored for 3 h after injection. Virgin females developed significantly larger fevers than did males at higher doses. There were no significant alterations in either fever height or duration as a function of the phase of the reproductive cycle in the females. Both pregnant and postparturient rats within the several days around birth displayed significantly lower fevers than did virgin females, but there was no further reduction in the immediate periparturient period. These data indicate that there are sex‐, and possibly hormone‐dependent differences in the central mechanisms involved in fever generation and antipyresis.
Prevalence of allergic rhinitis and nasal smear eosinophilia in 11‐ to 15 yr‐old children in Shiraz
Authors: Miri Sara , Farid Reza , Akbari Hedayat , Amin Reza
Published: October 2006

Allergic rhinitis (AR) is a common condition among schoolchildren. The prevalence rate of AR differs among countries and even among regions within the same country. The objective of this study was to determine the prevalence of nasal symptoms and signs of AR and nasal smear eosinophilia in 11‐ to 15‐yr‐old children in Shiraz. A total of 4584 children aged 11–15 yr of both sexes were surveyed from May 1995 to April 1996, and nasal symptoms and signs of AR (sneezing, rhinorrhea, nasal blockage, itching, color change, mucosal swelling, nasal wetness, and nasal crease), based on questionnaire and ear, nose and throat (ENT) examination were recorded. In addition, smears were taken from nasal secretions and stained. The results compared with nasal smears related to 340 healthy children. 1008 (22%) schoolchildren had nasal symptoms of AR (based on the questionnaire), 445 (9.7%) were identified as having nasal symptoms and signs of AR (based on the questionnaire and ENT specialist examination), and 226 (5.8%) had nasal symptoms and signs of AR associated with nasal eosinophilia (based on the questionnaire, ENT specialist examination and positive nasal smear for eosinophilia). Nasal eosinophilia was present in 274 (62%) children with nasal symptoms and signs of AR. This survey showed that prevalence of nasal symptoms and signs of AR was high in schoolchildren in Shiraz. Nasal smear eosinophilia had a diagnostic specificity of 96% and sensitivity of 62% and seems to be a potentially valuable test for AR.
Allergic conjunctivitis in children with asthma, rhinitis and eczema in a secondary outpatient clinic
Authors: Gradman Josefine , Wolthers Ole D.
Published: October 2006

Little evidence is available on the prevalence of allergic conjunctivitis in pediatric populations. The objective of this study was to assess the cumulative prevalence of allergic conjunctivitis in children with rhinitis, asthma and eczema in a secondary pediatric outpatient clinic. Children aged 5–15 yr referred during the period of 2002–2004 in whom allergic conjunctivitis, asthma, allergic rhinitis or eczema was diagnosed were included in a retrospective survey. At referral patient characteristics, history, symptoms, signs and results of type 1 allergy tests were entered into an electronic form. Four hundred and fifty‐eight children with a mean age of 9.4 yr were studied. Of 316, 324 and 149 children with rhinitis, asthma or eczema, respectively, 133 (42%), 78 (24%) and 45 (30%) had concomitant allergic conjunctivitis. One hundred and thirty‐seven (30%) had allergic conjunctivitis, of whom 133 (97%) also had allergic rhinitis, 77 (56%) asthma and 45 (33%) eczema. One hundred and twenty‐five (91%) of the children with allergic conjunctivitis had positive allergy tests to one or more allergens, sensitization to house dust mites being more frequent in chronic allergic conjunctivitis than in acute allergic conjunctivitis (95% vs. 53%; p < 0.01). Sensitization to grass was more frequent in children with acute allergic conjunctivitis (78% vs. 57%; p = 0.03). In a secondary pediatric outpatient clinic allergic conjunctivitis is a frequent co‐morbidity to allergic rhinitis and to asthma and eczema. Allergic conjunctivitis need to be included as an important co‐morbidity in future guidelines on asthma, rhinitis and eczema management.
Association between cord blood IgE and genetic polymorphisms of interleukin‐4, the β‐subunit of the high‐affinity receptor for IgE, lymphotoxin‐α, and tumor Necrosis factor‐α
Authors: Wen Hui‐Ju , Lin Ying‐Chu , Lee Yung‐Ling , Guo Yueliang Leon
Published: October 2006

High cord blood immunoglobulin E (cbIgE) is known to be associated with increased risks of atopic diseases in childhood. The relationship between genetic polymorphisms and high cbIgE has not been well documented. A cross‐sectional study was conducted to assess the association between cbIgE and genetic polymorphisms of interleukin (IL)‐4 ‐590C/T, the β‐subunit of the high‐affinity receptor for IgE (FcɛRI‐β) E237G, lymphotoxin (LT)‐αNcoI alleles, and tumor necrosis factor (TNF)‐α ‐308G/A. A total of 320 mother–neonate pairs were recruited from four maternity hospitals from different locations of Taiwan. Cord blood was obtained and assayed for cbIgE. Polymerase chain reaction followed by restriction fragment length polymorphism was used to assess the genotypes. Three hundred pairs of mothers and neonates were included in the final analysis. Infants with IL‐4 ‐590 C allele were found to have higher risk of elevated cbIgE (≥0.35 IU/ml, 24.3%) (p = 0.004). After adjusting for gender, birth order, maternal age, and history of allergic disease in maternal and paternal families, odds ratios for CC and CT genotypes were 4.41 and 3.16 (95% confidence interval 0.78–22.67, and 1.66–6.13), respectively, using TT genotype as reference. The genotypes of FcɛRI‐β, LT‐α, and TNF‐α were not associated with cbIgE before or after the adjustment. Our finding suggested a significant association of cbIgE with genetic polymorphism of IL‐4 ‐590C/T, but not with the genotypes of FcɛRI‐β, LT‐α, and TNF‐α.
Characterisation of aurone biosynthesis in Antirrhinum majus
Authors: Davies Kevin M. , Marshall Gayle B. , Bradley J. Marie , Schwinn Kathy E. , Bloor Stephen J. , Winefield Chris S. , Martin Cathie R.
Published: October 2006

Aurones are bright yellow flavonoids produced in petals of a limited range of plant species, including Antirrhinum majus. The biosynthesis of aurones is thought to occur by the action of aureusidin synthase (AUS), and possibly aureusidin 7‐O‐glucosyltransferase (A7GT). The temporal and spatial occurrence of AUS and A7GT transcript was examined in wild‐type A. majus and two mutant lines; sulfurea, which has increased aurone production in petals, and violacea, which has reduced aurone production. AUS and A7GT transcript abundance was similar in all three lines, increasing during flower development coincident with yellow coloration. The spatial pattern of AUS occurrence was also similar in all three lines, being spatially restricted to the inner epidermis of the face and throat of the lower petal. A new recessive line (CFR1011) with greatly reduced aurone production in all parts of the petal was identified by ethylmethanesulfonate mutagenesis of the homozygous recessive sulfurea line. Transcript abundance for AUS was not changed in the CFR1011 line compared with the wild‐type line, and neither were any point mutations detected in the coding sequences for AUS or A7GT. Thus, the sulfurea, violacea and CFR1011 mutations do not seem to control aurone production through a change in transcript abundance of the predicted biosynthetic genes AUS or A7GT. To examine AUS gene regulation further, the putative AUS gene promoter region was isolated and compared with other A. majus flavonoid gene promoters. A number of conserved potential regulatory regions were identified, in particular a consensus site for the MYB‐type transcription factors.
The evolutionary fate of recently duplicated retrogenes in mice
Authors: GAYRAL P. , CAMINADE P. , BOURSOT P. , GALTIER N.
Published: October 2006

Inferences about the evolutionary impact of gene duplications often rely on the analysis of their long‐term outcome. The fate of the majority of them must, however, be decided shortly after duplication. Here we analysed the evolutionary pattern of 10 mouse genes very recently duplicated by retrotransposition, by sequencing the retroposed copy in five to 10 closely related mouse species. In all cases the retroposed copy experienced accelerated nonsynonymous evolution whereas the divergence pattern of the source copy appeared unaffected by the duplication, consistent with the neofunctionalization model. The analysis further revealed that most retrogenes, including pseudogenes, did not experience a period of relaxed neutral evolution, but have been submitted to purifying selection ever since their retroposition. We propose that these duplicates play a biochemical role but are not indispensable. Purifying selection prevents them from acquiring a negative role until they are lost or silenced. This period of unnecessary redundancy could in rare cases give the time for new functions to evolve.
Foraging performance of diet‐induced morphotypes in pumpkinseed sunfish (Lepomis gibbosus) favours resource polymorphism
Authors: PARSONS K. J. , ROBINSON B. W.
Published: October 2006

Morphological plasticity can influence adaptive divergence when it affects fitness components such as foraging performance. We induced morphological variation in pumpkinseed sunfish (Lepomis gibbosus) ecomorphs and tested for effects on foraging performance. Young‐of‐year pumpkinseed sunfish from littoral and pelagic lake habitats were reared each on a ‘specialist diet’ representing their native habitat‐specific prey, or a ‘generalist diet’ reflecting a combination of native and non‐native prey. Specialist and generalist diets, respectively, induced divergent and intermediate body forms. Specialists had the highest capture success on their native prey whereas generalist forms were inferior. Specialists faced trade‐offs across prey types. However, pelagic specialists also had the highest intake rate on both prey types suggesting that foraging trade‐offs are relaxed when prey are abundant. This increases the likelihood of a resource polymorphism because the specialized pelagic form can be favoured by directional selection when prey are abundant and by diversifying selection when prey resources are restricted.
Morphological and genetic divergence of intralacustrine stickleback morphs in Iceland: a case for selective differentiation?
Authors: ÓLAFSDÓTTIR G. Á. , SNORRASON S. S. , RITCHIE M. G.
Published: October 2006

The evolutionary processes involved in population divergence and local adaptation are poorly understood. Theory predicts that divergence of adjacent populations is possible but depends on several factors including gene flow, divergent selection, population size and the number of genes involved in divergence and their distribution on the genome. We analyse variation in neutral markers, markers linked to putative quantitative trait loci and morphological traits in a recent (< 10 000 years) zone of primary divergence between stickleback morphs in Lake Thingvallavatn, Iceland. Environmental factors, especially predation, are clearly implicated in reducing gene flow between morphs. There is continuous morphological and genetic variation between habitats with a zone centre similar to secondary contact zones. Individual microsatellite loci are implicated as being linked to adaptive variation by direct tests as well as by differences in cline shape. Patterns of linkage disequilibria indicate that the morphs have diverged at several loci. This divergence shows parallels and differences with the well‐studied limnetic–benthic stickleback morphs, both in phenotypic divergence and at the genomic level.
Are juvenile coral‐trouts (Plectropomus) mimics of poisonous pufferfishes (Canthigaster) on coral reefs?
Authors: Frisch Ashley J.
Published: October 2006

The juveniles of three species of coral‐trout (Plectropomus) resemble two species of poisonous pufferfish (Canthigaster), one of the latter having two distinct colour morphs. Qualitative data are assembled on the diet, feeding mode, palatability, relative abundance, habitat and geographical range of each species. All observations are consistent with the hypothesis that juvenile coral‐trouts are generalized mimics of pufferfishes. Speciation within Plectropomus is discussed with respect to its mimetic relationships with Canthigaster.
Community structure of fishes in Cabo Pulmo Reef, Gulf of California
Authors: Alvarez‐Filip Lorenzo , Reyes‐Bonilla Héctor , Calderon‐Aguilera Luis E.
Published: October 2006

In order to analyse the structure of the fish community in Cabo Pulmo Reef., 36 cylindrical stationary censuses (5 m radius, 15 min of observation time) were conducted in October 2003 (warm season) and February 2004 (cold season). To explore the relationship with depth and associated variables, we considered a shallow stratum (<5 m) and a deep stratum (>5.5 m; depth range was between 2 and 15 m). Species richness, number of individuals, and the indices of diversity (Shannon), evenness (Pielou) and taxonomic distinctness were computed for each census. A total of 8725 fish were recorded (3829 in the warm season and 4896 in the cold season), belonging to 62 species, included in 23 families. Thalassoma lucasanum and Chromis atrilobata were the dominant species (62.5% of total abundance, and occurrence of 97% and 72%, respectively). Conversely, 50 species had low relative abundance, <1% of total abundance, and a frequency of occurrence <50% of the census. None of the ecological descriptors were significantly different between seasons (P > 0.5), but richness, abundance and taxonomic differentiation were higher in the deeper zone. The analysis of similarity and ordination analysis did not show consistent clusters by season or depth, but suggest similarity among census of deeper zones. Most species preference for physical factors associated with deeper zones maybe the reason for the pattern observed in this study.
Microbial status in seawater and coastal sediments during pre‐ and post‐tsunami periods in the Bay of Bengal, India
Authors: Ramesh Subramani , Jayaprakashvel Mani , Mathivanan Narayanasamy
Published: October 2006

Tsunami, the natural disaster, which occurred on December 26, 2004 in the Indian Ocean, caused severe damage to mankind in the coastal areas. Total loss of life and economic loss because of this disaster have been estimated by various agencies but its effect on microbial density has not been probed. With our previous results on microbial populations in four locations of the Chennai coast of the Bay of Bengal, India in the pre‐tsunami period, the change in microbial populations was studied after the tsunami at regular intervals in the same locations. Coastal sediment and seawater samples were collected from four different locations after 5–10 h and thereafter at intervals of every 7 days up to 28 days post‐tsunami. Bacteria, fungi and actinomycetes were isolated from the marine samples by serial dilution on respective media. Before the tsunami, the bacterial population was higher in seawater samples than the sediments, whereas fungi and actinomycetes were recorded only in the sediments. The microbial population remarkably increased 5–10 h post‐tsunami in all the marine samples irrespective of the location. However, it slowly declined in the subsequent days and became similar to that of the population recorded before the tsunami. The population of gram‐positive bacteria increased whereas the gram‐negative bacterial population decreased after the tsunami. Further, populations of pathogenic bacteria such as coliform and vibrios did not increase after the tsunami. It has been observed that the increase in populations of bacteria and actinomycetes even after 28 days of tsunami may be due to the introduction of foreign microorganisms that developed the ability to survive in the extreme environment by exhibiting special characteristics such as pigmentation and production of exopolysaccharides.
Response of the soft coral Heteroxenia fuscescens to ultraviolet radiation regimes as reflected by mycosporine‐like amino acid biosynthesis
Authors: Zeevi Ben‐Yosef Dafna , Kashman Yoel , Benayahu Yehuda
Published: October 2006

The variation in mycosporine‐like amino acid (MAA) concentration in the soft coral Heteroxenia fuscescens in relation to changes in ultraviolet radiation (UVR) regimes was investigated at the Gulf of Eilat, northern Red Sea. Solar radiation (300–700 nm) was measured for different depths and seasons. The UVR irradiance was measured to a depth of 25 m on the reef. The mean attenuation coefficient for UV‐B measured in winter was twofold that of the summer value. Separation of H. fuscescens extracts by reverse‐phase isocratic high‐performance liquid chromatography revealed a single MAA compound, palythine (λmax = 320 nm). Possible seasonal changes in MAAs in colonies of H. fuscescens along a depth gradient were examined on different dates. Palythine concentrations in the colonies were significantly higher in summer than in the other seasons particularly in shallow water. Possible changes in MAA content in colonies of H. fuscescens as a result of UVR protection, were determined by experiments conducted for periods of 1 week, 1 month and 3 months, at a depth of 5 m. In these experiments colonies were removed from the natural substrate and placed underwater, protected from UVR by a PVC filter. Significant differences between UV‐exposed and protected colonies of H. fuscescens were found only in the 3‐month experiment conducted during the summer. These findings demonstrate that UVR is an important environmental factor regulating MAA biosynthesis in the soft coral H. fuscescens.
International Trade, Technology, and the Wage Gap: Evidence from Granger‐causality Tests*
Authors: Ghosh Sucharita , Yamarik Steven
Published: October 2006

In this paper, we propose an alternative approach under which to examine the source of the increased wage gap between skilled and unskilled workers in US manufacturing. Rather than imposing the assumptions inherent in a given structural form, we posit a long‐run equilibrium relationship between international trade, technology, and the wage premium using a vector error‐correction model. We first test for the existence of a long‐run relationship using cointegration tests. If a cointegrating relationship is found, we then conduct tests on the direction of the long‐run relationship and of Granger causality. We apply our approach to each two‐digit and four‐digit SIC industry and find evidence in support of international trade being an important source of the wage gap. Our results suggest that it is premature to dismiss international trade as a possible suspect behind the rising wage premium.
The Effect of EMU on Tourism*
Authors: Gil‐Pareja Salvador , Llorca‐Vivero Rafael , Martínez‐Serrano José Antonio
Published: October 2006

This paper estimates the effect of the euro on intra‐EMU tourist flows by using a panel dataset of 20 OECD countries over the period 1995–2002. The results reveal that the euro has increased tourism, with an effect of around 6.5%. This is a noticeable impact given the early stage of the EMU analyzed. The robustness checks show that the evidence of a positive impact is quite widespread across EMU destination countries.
Craniofacial levels and the morphological maturation of the human skull
Authors: Bastir Markus , Rosas Antonio , O’Higgins Paul
Published: October 2006

It is well known that the human skull achieves adult size through a superior–inferior gradient of maturation. Because the basicranium matures in size before the face, it has been suggested that the form of the basicranium might have ontogenetic knock‐on effects on that of the face. However, although sequential spatially organized maturation of size is well described in the cranium, the maturation of skull shape is not. Knowledge of the maturation of shape is important, nevertheless, because it is claimed that the early determination of the spatial configuration of basicranial components, where the facial skeleton attaches, is relevant in the spatio‐temporal ontogenetic cascade from basicranium to face. This paper examines the ontogeny of various components of the human skull in 28 individuals from the longitudinal Denver Growth Study. Sixty‐six landmarks and semilandmarks were digitized on 228 X‐rays and analysed using geometric morphometric methods. Bootstrapped confidence intervals for centroid size support previous studies suggesting a supero‐inferior gradient of growth maturation (size over time), while developmental maturation (shape over time) is more complex. A sequence of shape maturation is described, in which the earliest structure to mature in shape was the midline cranial base (7–8 years), followed by the lateral cranial floor (11–12), midline neurocranium (9–10) and facial and mandibular structures (15–16). The absolute ages of shape maturation of the latter three depended on the criterion of maturity used, which was not the case for the basicranial components. Additionally, ontogenetic dissociations were found between the maturation of size and shape of the midline cranial base and lateral floor, possibly underlining its role as structural ‘interface’ between brain and facial ontogeny. These findings imply potential for bidirectional developmental influences between the lateral cranial floor and the face until about 11–12 years. The findings are discussed with regard to their relevance for palaeoanthropology and especially the evolutionary and developmental bases of skull morphological variation.
Chilean women’s preferences regarding mode of delivery: which do they prefer and why?
Authors: Angeja ACE , Washington AE , Vargas JE , Gomez R , Rojas I , Caughey AB
Published: October 2006

Objective  Caesarean section rates in Chile are reported to be as high as 60% in some populations. The purpose of this study was to determine pregnant Chilean women’s preferences towards mode of delivery.

Design  Interviewer‐administered cross‐sectional survey.

Setting  Prenatal clinics in Santiago, Chile.

Population  Pregnant women in Santiago, Chile.

Methods  Of 180 women completing the questionnaire, 90 were interviewed at a private clinic (caesarean delivery rate 60%) and 90 were interviewed at a public clinic (cesarean delivery rate 22%). Data collected included demographics, preferred mode of delivery, and women’s attitudes towards vaginal and caesarean deliveries.

Main outcome measures  Mode of delivery preferences, perceptions of mode of delivery measured on a 1–7 Likert scale.

Results  The majority of women (77.8%) preferred vaginal delivery, 9.4% preferred caesarean section, and 12.8% had no preference. There was no statistical difference in preference between the public clinic (11% preferred caesarean) and the private clinic (8% preferred caesarean, P= 0.74). Overall, women preferring caesarean birth were slightly older than other groups (31.6 years, versus 28.4 years for women who preferred vaginal and 27.3 years for women who had no preference, P= 0.05), but there were otherwise no differences in parity, income, or education. On a scale of 1–7, women preferring caesarean birth rated vaginal birth as more painful, while women preferring vaginal birth rated it as less painful (5.8 versus 3.7, P= 0.003). Whether vaginal or caesarean, each group felt that their preferred mode of delivery was safer for their baby (P < 0.001).

Conclusions  Chilean women do not prefer caesarean section to vaginal delivery, even in a practice setting where caesarean delivery is more prevalent. Thus, women’s preferences is unlikely to be the most significant factor driving the high caesarean rates in Chile.
Extracellular S‐nitrosoglutathione, but not S‐nitrosocysteine or N2O3, mediates protein S‐nitrosation in rat spinal cord slices*
Authors: Romero Jorge M. , Bizzozero Oscar A.
Published: October 2006

There is evidence that protein S‐nitrosothiols (PrSNOs) accumulate in inflammatory demyelinating disorders like multiple sclerosis and experimental allergic encephalomyelitis. However, very little is known regarding the mechanism by which PrSNOs are formed in target cells. The present study compares the ability of potential intercellular mediators of nitrosative damage including S‐nitrosoglutathione (GSNO), S‐nitrosocysteine and N2O3 to induce protein S‐nitros(yl)ation in the spinal cord, a CNS region that is commonly affected in multiple sclerosis and experimental allergic encephalomyelitis. The results clearly demonstrate that while all three NO‐donors cause S‐nitrosation of proteins in cell‐free systems, only GSNO is a viable S‐nitrosating agent in rat spinal cord slices. Generation of PrSNOs with GSNO occurs by S‐transnitrosation as the process was not inhibited by either the NO‐scavenger rutin or the N2O3‐scavenger azide. Contrary to other cell types, nerve cells incorporate intact GSNO and neither functional l‐amino acid transporters nor cell‐surface thiols are required. We also found that there is a restricted number of proteins available for S‐nitrosation, even at high, non‐physiological concentrations of GSNO. These proteins are highly concentrated in mitochondria and mitochondria‐rich subcellular compartments. This study is relevant to those CNS disorders characterized by excessive nitric oxide production.
Low‐Dose Topiramate Versus Lamotrigine in Migraine Prophylaxis (The Lotolamp Study)
Authors: Gupta Praveen , Singh Sumit , Goyal Vinay , Shukla Garima , Behari Madhuri
Published: October 2006

Objective.—To assess the efficacy and safety of topiramate and lamotrigine for prophylaxis in patients with frequent migraine as compared to each other and to placebo.

Methods.—Sixty patients with frequent migraine (more than 4 attacks per month) from the headache clinic at a tertiary referral centre in India were randomized to receive 50 mg topiramate/lamotrigine or matching placebo for 1 month each in 2 divided doses in 4 phases in a crossover manner with a washout period of 7 days in between. Primary efficacy measure was responder rate (50% decrease in mean migraine frequency/intensity). Secondary efficacy measures included reduction in mean monthly frequency, intensity, duration, rescue medication use, migraine associated symptoms, and adverse events.

Statistical analysis.—Analysis was on intention to treat basis. Data were analyzed as correlated data. Generalized estimation equation was used to compute overall mean standard deviation and 95% confidence intervals for each of the outcome variables. Bonferroni's correction done for multiple comparisons. P value of <.017 was taken as significant.

Results.—Fifty‐seven patients comprised the intent‐to‐treat population. Four patients withdrew from the study at various phases, none because of the side effects. Responder rate for frequency was significantly higher for topiramate versus placebo (63% vs 30%, P < .001), and versus lamotrigine (63% vs 46 %, P= .02). For intensity of headache also a responder rate of topiramate versus placebo (50% vs 10%, P < .001), and versus lamotrigine (50% vs 41%, P= .01) was observed. Topiramate showed statistically significant benefits (P < .017) in most of the secondary efficacy measures while lamotrigine was beneficial for reduction in headache frequency, and migraine associated symptoms. Adverse events were similar.

Conclusion.—Low‐dose topiramate is efficacious in migraine prophylaxis as compared to both placebo and lamotrigine. Lamotrigine in low doses might be beneficial for headache frequency; however, longer trials are required to establish its efficacy on the intensity and frequency of migraine.
Quatrefoil Reentry Caused by Burst Pacing
Authors: JANKS DEBORAH L. , ROTH BRADLEY J.
Published: October 2006

Background: Experiments and clinical studies have shown that high‐frequency (burst) pacing can induce reentry and fibrillation without a strong shock. We hypothesize that a train of weak stimuli induces quatrefoil reentry, and investigate the mechanism and threshold for this mode of reentry induction.

Methods: We apply a train of weak stimuli at different pacing rates to determine the threshold necessary to induce quatrefoil reentry. Numerical calculations are used to simulate cardiac tissue, based on the bidomain model with unequal anisotropy ratios. We consider both anodal and cathodal stimuli.

Results: Quatrefoil reentry is initiated using much smaller currents during burst pacing (0.9 mA) compared to a single premature pulse (8.6 mA). As we varied the pacing rate, we observed reentry at the border between different modes of phase locking, such as between 1:1 and 2:1 responses.

Conclusion: Burst pacing can significantly reduce the threshold for reentry. However, the extreme sensitivity of reentry induction to the exact number of stimuli in the pulse train makes the method difficult to use as a consistent, reproducible way to induce reentry.
Monazite Coatings on SiC Fibers I: Fiber Strength and Thermal Stability
Authors: Boakye E. E. , Mogilevsky P. , Parthasarathy T. A. , Hay R. S. , Welter J. , Kerans R. J.
Published: October 2006

Commercially available SiC fibers were coated with monazite (LaPO4) using a continuous vertical coater at 1100°C. Coated fibers were heat treated in dry air, argon, and laboratory air at 1200°C for 1–20 h. The tensile strengths of uncoated and coated fibers were measured and evaluated before and after heat treatment. Fiber coating did not degrade SiC fiber strength, but heat treatment afterwards caused significant degradation that correlated with silica scale thickness. Possible strength degradation mechanisms for the coated fibers are discussed. Coating morphology, microstructure, and SiC oxidation were observed with scanning electron microscopy and transmission electron microscopy. Monazite reacted with SiC to form lanthanum silicate (La2Si2O7) in argon, but was stable with SiC in air. Despite the large coefficient of thermal expansion difference between monazite and SiC, micron thick monazite coatings did not debond from most types of SiC fibers. Possible explanations for the thermomechanical stability of the monazite fiber coatings are discussed.
Local Structures in the ZrO2–15 mol% Fe2O3 System Obtained by Ball Milling
Authors: Figueroa Santiago , Desimoni Judith , Rivas Patricia C. , Caracoche María C. , De Sanctis Oscar
Published: October 2006

The Mössbauer effect and perturbed angular correlation techniques have been used to investigate the nature and thermal stability of Zr and Fe surroundings in a solid solution of zirconia and 15 mol% hematite obtained by mechanical mixing. Hematite incorporates completely into the zirconia lattice, resulting in a substitutional cubic structure that remains stable over a wide thermal range. Upon annealing at 900°C, a 20% decrease in the iron solubility occurs, accompanied by the cubic to tetragonal zirconia transformation. Both the cubic and the tetragonal crystalline solid solutions exhibit two local coordinations for each one of the probes. The presence of the charge‐balancing oxygen vacancy, which appeared after Fe3+ substitution for Zr4+ and located as a nearest neighbor to host and dopant cations, is reflected by the most disordered interaction, which shows similar characteristics for the cubic and the tetragonal polymorphs. The other local coordination, described at Zr sites by an electric field of phase‐dependent intensity, has been thought to depict a direct interaction between very near Fe and Zr cations.
Imaging Clathrin Dynamics in Drosophila melanogaster Hemocytes Reveals a Role for Actin in Vesicle Fission
Authors: Kochubey Olexiy , Majumdar Amitabha , Klingauf Jurgen
Published: October 2006

Clathrin‐mediated endocytosis (CME) is essential for maintaining many basic cellular processes. We monitored the dynamics of clathrin in live Drosophila melanogaster hemocytes overexpressing clathrin light chain fused to enhanced green fluorescent protein (EGFP) using evanescent wave microscopy. Membrane‐associated clathrin‐coated structures (CCS) constitutively appeared at the peripheral filopodial membrane, moved centripetally while growing in intensity, before being eventually endocytosed within a few tens of seconds. This directed CCS traffic was independent of microtubules but could be blocked by latrunculin A. Taking advantage of available mutants of Drosophila, we expressed clathrin–EGFP in wasp and shibire mutant backgrounds to study the role of actin and dynamin in CCS dynamics and CME in hemocytes. We show that actin plays an essential role in CME in these cells, and that actin and dynamin act at the same stage, but independent of each other. Drosophila melanogaster hemocytes proved to be a promising model system to uncover the molecular events during CME in combining live‐cell imaging and genetic analysis.
Leaf Epidermal Cells: A Trap for Lipophilic Xenobiotics
Authors: Liu Zhiqian
Published: October 2006

Plant surfaces are covered by a layer of cuticle, which functions as a natural barrier to protect plants from mechanical damage, desiccation, and microbial invasion. Results presented in this report show that the epicuticular wax and the cuticle of plant leaves also play an important role in resisting xenobiotic invasion. Although the epicuticular wax is impermeable to hydrophilic xenobiotics, the cuticle not only restricts the penetration of hydrophilic compounds into leaf cells, but also traps lipophilic ones. The role of the epidermal cells of plant leaves in resisting xenobiotic invasion has been neglected until now. The present study shows, for the first time, that the epidermal cells may reduce or retard the transport of lipophilic xenobiotics into the internal tissues through vacuolar sequestration. Although the guard cells appear to be an easy point of entry for xenobiotics, only a very small proportion of xenobiotics present on the leaf surface actually moves into leaf tissues via the guard cells.

(Managing editor: Wei Wang)
A New Pregnane from Munronia delavayi Franch (Meliaceae)
Authors: Cai Xiang‐Hai , Luo Xiao‐Dong , Zhou Jun , Hao Xiao‐Jiang
Published: October 2006

To search for pharmacologically active constituents of folk medicine, a new pregnane, 2α,3α,15β‐trihy‐droxy‐20(S)‐tigloyl‐pregnane (compound 1), and nine known compounds, geranylgeraniol (compound 2), β‐daucosterol (compound 3), 6‐hydroxystigmast‐4‐en‐3‐one (compound 4), sitoindoside I (compound 5), sitoindoside II (compound 6), β‐sitosterol (compound 7), kaempferol (compound 8), quercetin (compound 9), and rutin (compound 10), were isolated from the ethanol extract of whole plants of Munronia delavayi Franch using chromatographic methods. The structures of compounds 1–10 were elucidated on the basis of spectral data.

(Managing editor: Wei Wang)
Colorimetric Assay to Determine In Vitro Antibacterial Activity Against Clinical Isolates: Enhanced Activity in Damaged Chinese Masson Pine Needles
Authors: Dong Guijun , Pan Weidong , Zheng Tao , Liu Xianghui , Liu Gongshe
Published: October 2006

A colorimetric assay for antibacterial susceptibility testing of clinical isolates (Escherichia coli, Pseudomonas aeruginosa, Shigella dysenteriae, Staphylococcus aureus, Bacillus cereus, and Streptococcus pneumoniae) is described based on the reduction of a novel tetrazolium salt, 3‐(4,5‐dimethylthiazol‐2‐yl)‐5‐(3‐carboxymethoxyphenyl)‐2‐(4‐sulfophenyl)‐2H‐tetrazolium (MTS), in the presence of phenazine methosulfate (PMS) as an electron‐coupling agent. The combination of 200 μg/mL MTS with 25 μmol/L PMS resulted in production of large amounts of formazan within 1 h of exposure. In this setting, fractions extracted from Chinese Masson pine (Pinus massoniana Lamb.) needles damaged by the pine caterpillar Dendrolimus punctatus Walker were found to have enhanced levels of antibacterial activity. These fractions, which were designated “Master”, “Technique”, and “Strength”, were isolated and identified by reverse‐phase C18 cartridge concentration, gel filtration, and affinity chromatography. Two fractions purified from healthy and undamaged needles were designated H1 and H2, respectively. For all test bacteria species. Technique produced the lowest minimal inhibitory concentrations (MICs), ranging from 2 to 32 μg/mL, and H2 produced the highest values, with four of the six MICs being higher than 128 μg/mL We found that the Rmax model fitted the data well in that the r2 ranged between 0.87 and 0.96 (median, 0.92) and no statistically significant deviations from the model were found (P= 0.23). The median coefficient of variation of the log RC50 values and the slope m of the fitted model for all six strains among the replicates were 38 and 41%, respectively. In the course of the investigation, the physiological and functional factors involved in pest damage to plants were also explored. In summary, the MTS‐PMS colorimetric assay has advantages over existing methods for the examination of antibacterial activity, and could be developed further such that it would be suitable for screening new antibiotic molecules.

(Managing editor: Ping He)
Ecdysteroids: the overlooked sex steroids of insects? Males: the black box
Authors: DE LOOF ARNOLD
Published: October 2006

Abstract
The paradigm, still around in textbooks, that ‘in insects sex is strictly genetic, thus that they do not have sex hormones’, is mainly based on a wrong interpretation of the ‘gynandromorph argument’. It is no longer tenable. Given the fact that vertebrates and invertebrates probably had a common, sexually reproducing ancestor, there is no reason to assume that only vertebrates need sex hormones. The major function of sex hormones is to inform the somatoplasm about developmental changes that take place in the gonads. In contrast to juvenile hormone and neuropeptides, ecdysteroids meet all criteria to act as sex hormones, which was probably their ancient role. Their much better documented role in moulting and metamorphosis was a secondary acquisition that enabled arthropods to cope with growth problems, imposed by a rigid cuticle. Female insects use 20‐hydroxyecdysone (20E), secreted by the follicle cells of the ovary, in a similar way as females of egg‐laying vertebrates use estrogens. For a variety of reasons, the possibility that ecdysteroids, in particular ecdysone (E), might also act as sex hormones in male insects, thus as the counterpart of testosterone of vertebrates, has been very much overlooked. Thanks to the recent discovery of the molecular basis of the haploid‐diploid system of sex determination in the honeybee, the characterization of Halloween genes, proteomics, RNAi and so on, it now becomes possible to verify whether in insects, as with vertebrates, males are the endocrinologically default gender form.
ten‐a overexpression causes abnormal pattern in the Drosophila compound eye
Authors: NGERNSIRI LERTLUK , FASCETTI NORA , ROMRATANAPAN SUPPALUK , BAUMGARTNER STEFAN
Published: October 2006

Abstract
Ten‐a is one of the two Drosophila proteins that belong to the Ten M protein family. This protein is a type II transmembrane protein and is expressed mainly in the embryonic CNS, in the larval eye imaginal disc and in the compound eye of the pupa. Here, we investigate the role of ten‐a during development of the compound eye by using the Gal4/UAS system to induce ten‐a overexpression in the developing eye. We found that overexpression of ten‐a can perturb eye development during all stages examined. In an early stage, overexpression of ten‐a in eye primordial cells caused small and rough eyes and interfered with photoreceptor cell recruitment, resulting in some ommatidia having fewer or extra photoreceptor cells. Conversely, ten‐a overexpression during ommatidial formation caused severe eye defects due to absence of many cellular components. Interestingly, overexpression of ten‐a in the late stage developing ommatidial cluster affected the number of pigment cells, caused cone cells proliferation in many ommatidia, and caused some photoreceptor cell defects. These results suggest that ten‐a may be a novel gene required for normal eye morphogenesis.