bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mechanism of ouabain‐induced contractions in guinea‐pig tracheal rings
Authors: Espinosa‐Tanguma R , Valle‐Aguilera JR , Zarazúa‐Garcia O , Navarro‐Huerta MP , Pecina C , Sánchez‐Armass S 
Published: November 2004

Summary1. The aim of the present study was to analyse the mechanism that underlies the force development induced by ouabain (ED100 = 100 µmol/L) in guinea‐pig tracheal rings.2. The dose–response curve showed that concentrations of ouabain above 100 µmol/L evoked smaller contractions.3. Ouabain, at 100 µmol/L, produced two long‐lasting consecutive transient contractions. The peak of the first contraction was 750 ± 75 mg, whereas the peak of the second contraction was 280 ± 46 mg.4. Both contractions induced by ouabain were dependent on extracellular Ca2+. Consistent with this, verapamil (10 µmol/L) inhibited the first and second contractions by 77 and 59%, respectively.5. 3,4‐Dichlorobenzamil (20 µmol/L) inhibited the first and second contractions by 68 and 97%, respectively.6. Simultaneous exposure to 15 mmol/L sodium solution and 100 µmol/L ouabain evoked only one transient contraction, larger (987 ± 135 mg) than either of the ouabain‐induced contractions.7. Inhibition of the sarcoendoplasmic reticulum Ca‐ATPase with cyclopiazonic acid potentiated the first and second ouabain‐induced contractions by 47 and 300%, respectively.8. Atropine (1 µmol/L) inhibited the first and second contractions by 44 and 76%, respectively.9. In conclusion, the results of the present study are relevant to the understanding of the mechanisms by which ouabain (100 µmol/L) contracts guinea‐pig tracheal rings. At the muscular level, oubain induces Ca2+ influx through L‐type Ca2+ channels and the reverse mode of the sodium–calcium exchanger. At the nerve terminals, ouabain promotes the release of acetylcholine secondary to the increase in Ca2+ influx mediated by the reverse mode of the sodium–calcium exchanger.
Oscillatory transient inward currents in ventricular myocytes of healthy versus myopathic Syrian hamster
Authors: Wu Sze‐Hsueh , Chen Yao‐Chang , Higa Satoshi , Lin Cheng‐I 
Published: November 2004

Summary1. The present experiments were performed in order to study abnormal action potential configuration and ion channel activity in ventricular myocytes obtained from 23 male myopathic Syrian hamsters (Biobreeders strain 14.6, 32–52 weeks old) compared with 10 age‐matched healthy control hamsters (Biobreeders F1B) by means of whole‐cell patch‐clamp techniques.2. The results show that the myopathic myocytes had a longer action potential duration, a reduced transient outward K+ current on depolarization and a smaller transient inward current on repolarization after prolonged depolarizing pulses (> 500 msec). However, the L‐type Ca2+ current and the inwardly rectifing K+ current were not significantly different from those of healthy myocytes.3. The oscillatory transient inward currents could be diminished by treatment with ryanodine (0.01–1 µmol/L), a sarcoplasmic reticulum (SR) Ca2+ release channel blocker, or with Na+‐free superfusate.4. We conclude that the hereditary myopathic hamsters are less likely to develop delayed afterdepolarization‐related transient inward currents and triggered arrhythmias owing to a smaller SR Ca2+ content.
Influence of form IA RubisCO and environmental dissolved inorganic carbon on the δ13C of the clam‐chemoautotroph symbiosis Solemya velum
Authors: Scott Kathleen M. , Schwedock Julie , Schrag Daniel P. , Cavanaugh Colleen M. 
Published: November 2004

SummaryMany nutritive symbioses between chemoautotrophic bacteria and invertebrates, such as Solemya velum, have δ13C values of ∼ −30 to − 35‰, considerably more depleted than phytoplankton. Most of the chemoautotrophic symbionts fix carbon with a form IA ribulose 1,5‐bisphosphate carboxylase (RubisCO). We hypothesized that this form of RubisCO discriminates against 13CO2 to a greater extent than other forms. Solemya velum symbiont RubisCO was cloned and expressed in Escherichia coli, purified and characterized. Enzyme from this recombinant system fixed carbon most rapidly at pH 7.5 and 20–25°C. Surprisingly, this RubisCO had an ɛ‐value (proportional to the degree to which the enzyme discriminates against 13CO2) of 24.4‰, similar to form IB RubisCOs, and higher than form II RubisCOs. Samples of interstitial water from S. velum's habitat were collected to determine whether the dissolved inorganic carbon (DIC) could contribute to the negative δ13C values. Solemya velum habitat DIC was present at high concentrations (up to ∼5 mM) and isotopically depleted, with δ13C values as low as ∼− 6‰. Thus environmental DIC, coupled with a high degree of isotopic fractionation by symbiont RubisCO likely contribute to the isotopically depleted δ13C values of S. velum biomass, highlighting the necessity of considering factors at all levels (from environmental to enzymatic) in interpreting stable isotope ratios.
Isolation and cultivation of Walsby's square archaeon
Authors: Bolhuis Henk , Poele Evelien M. te , Rodriguez‐Valera Francisco 
Published: November 2004

SummaryIn 1980, A. E. Walsby described a square halophilic archaeon. This archaeon is of specific interest because of its unique shape and its abundance in hypersaline ecosystems, which suggests an important ecophysiological role. Ever since its discovery, the isolation and cultivation of ‘Walsby's square archaeon’ has been a holy grail for many microbiologists working on halophiles. Despite their abundance and easy recognition by microscopy, all cultivation attempts have failed up to now, marking the organism as one of the unculturables. Cultivation of the square archaeon is essential to understand their ecophysiological role and the nature of their unique morphologically features. Here, we report the isolation and cultivation of the enigmatic square archaeon that we propose to name Haloquadratum walsbyi. Pure cultures are easily maintained in simple artificial hypersaline media. Initial growth experiments revealed a tolerance to high concentrations of MgCl2 (>2 M) in the presence of 3.3 M NaCl. Fresh cultures contained extraordinary large cells (>40 × 40 µm) without any visible division structures, ranking them among the largest prokaryotes known to date. The genome was estimated to contain approximately three million basepairs.
Insights into the genomic basis of niche specificity of Pseudomonas putida KT2440
Authors: Dos Santos V. A. P. Martins , Heim S. , Moore E. R. B. , Strätz M. , Timmis K. N. 
Published: November 2004

SummaryA major challenge in microbiology is the elucidation of the genetic and ecophysiological basis of habitat specificity of microbes. Pseudomonas putida is a paradigm of a ubiquitous metabolically versatile soil bacterium. Strain KT2440, a safety strain that has become a laboratory workhorse worldwide, has been recently sequenced and its genome annotated. By drawing on both published information and on original in silico analysis of its genome, we address here the question of what genomic features of KT2440 could explain or are consistent with its ubiquity, metabolic versatility and adaptability. The genome of KT2440 exhibits combinations of features characteristic of terrestrial, rhizosphere and aquatic bacteria, which thrive in either copiotrophic or oligotrophic habitats, and suggests that P. putida has evolved and acquired functions that equip it to thrive in diverse, often inhospitable environments, either free‐living, or in close association with plants. The high diversity of protein families encoded by its genome, the large number and variety of small aralogous families, insertion elements, repetitive extragenic palindromic sequences, as well as the mosaic structure of the genome (with many regions of ‘atypical’ composition) and the multiplicity of mobile elements, reflect a high functional diversity in P. putida and are indicative of its evolutionary trajectory and adaptation to the diverse habitats in which it thrives. The unusual wealth of determinants for high affinity nutrient acquisition systems, mono‐ and di‐oxygenases, oxido‐reductases, ferredoxins and cytochromes, dehydrogenases, sulfur metabolism proteins, for efflux pumps and glutathione‐S‐transfereases, and for the extensive array of extracytoplasmatic function sigma factors, regulators, and stress response systems, constitute the genomic basis for the exceptional nutritional versatility and opportunism of P. putida , its ubiquity in diverse soil, rhizosphere and aquatic systems, and its renowned tolerance of natural and anthropogenic stresses. This metabolic diversity is also the basis of the impressive evolutionary potential of KT2440, and its utility for the experimental design of novel pathways for the catabolism of organic, particularly aromatic, pollutants, and its potential for bioremediation of soils contaminated with such compounds as well as for its application in the production of high‐added value compounds.
The effects of topical application of phytonadione, retinol and vitamins C and E on infraorbital dark circles and wrinkles of the lower eyelids
Authors: Mitsuishi T , Shimoda T , Mitsui Y , Kuriyama Y , Kawana S 
Published: November 2004

SummaryBackground  Infraorbital dark circles and wrinkles of the lower eyelids are a cosmetic problem, especially with age.Aims  To determine whether a gel containing 2% phytonadione, 0.1% retinol and 0.1% vitamins C and E is effective in reducing dark under‐eye circles and wrinkles of the lower eyelids in healthy Japanese adults.Patients/Methods  Fifty‐seven adult Japanese volunteers with dark under‐eye circles and wrinkles were enrolled in an open label study. The gel formulation was applied twice daily to the lower eyelid site for 8 weeks. Haemostasis, pigmentation and wrinkles were evaluated by a physician and by the patients themselves, using a digital camera and a visual analogue scale respectively, after 4 and 8 weeks of treatment.Results  Topical application of the gel decreased not only haemostasis but also wrinkles after 8 weeks of treatment. Of 57 patients, 27 (47%) had reductions in haemostasis. Wrinkles were also decreased in some patients. However, pigmentation was not clearly removed by this gel.Conclusions  Topical application of the gel containing 2% phytonadione, 0.1% retinol, 0.1% vitamin C and 0.1% vitamin E was fairly or moderately effective in reducing dark under‐eye circles, especially in cases of haemostasis, over a short treatment period in healthy Japanese adults. This treatment also slightly decreased wrinkles.
Nicotinic acid/niacinamide and the skin
Authors: Gehring W 
Published: November 2004

SummaryNicotinic acid (also generally known as niacin) and niacinamide (also known as nicotinamide) are similarly effective as a vitamin because they can be converted into each other within the organism. The blanket term vitamin B3 is used for both.Niacinamide is a component of important coenzymes involved in hydrogen transfer. Here, the two codehydrogenases, nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP) are of central importance. Topical application of niacinamide has a stabilizing effect on epidermal barrier function, seen as a reduction in transepidermal water loss and an improvement in the moisture content of the horny layer. Niacinamide leads to an increase in protein synthesis (e.g. keratin), has a stimulating effect on ceramide synthesis, speeds up the differentiation of keratinocytes, and raises intracellular NADP levels. In ageing skin, topical application of niacinamide improves the surface structure, smoothes out wrinkles and inhibits photocarcinogenesis. It is possible to demonstrate anti‐inflammatory effects in acne, rosacea and nitrogen mustard‐induced irritation.Because of its verifiable beneficial effects, niacinamide would be a suitable component in cosmetic products for use in disorders of epidermal barrier function, for ageing skin, for improving pigmentary disorders and for use on skin prone to acne.
Patterns of neotenic differentiation in a subterranean termite,Reticulitermes speratus(Isoptera: Rhinotermitidae)
Authors: MIYATA Hitoshi , FURUICHI Hiroko , KITADE Osamu 
Published: November 2004

AbstractPlasticity in the caste developmental pathway is a remarkable characteristic of termite societies. InReticulitermes, two types of neotenic reproductive, nymphoids and ergatoids, may differentiate from nymphs and workers and take over reproduction in the colony after the death of the original primary reproductive pair. We examined the dynamics of newly differentiated nymphoids and ergatoids in experimentally orphaned laboratory colonies ofR. speratuswith different caste compositions. The period required for differentiation of nymphoids was shorter than that for differentiation of ergatoids. The sex ratio of neotenics was strongly female‐biased, particularly in ergatoids. The results suggested that the number of differentiated ergatoids was restricted by the existence of nymphs or nymphoids in a colony. Workers were assumed to kill most newly differentiated neotenics. Attack reflecting conflict between colony members is probably an important mechanism to control neotenic emergence.
Does the age of the host plant modulate migratory activity ofPlutella xylostella?
Authors: CAMPOS Wellington G. , SCHOEREDER José H. , SPERBER Carlos F. 
Published: November 2004

AbstractEphemeral plants and most tropical crops are available to herbivore insects as irregular and unpredictable patches of resources. Insects that exploit patched habitats usually have well‐developed migratory ability, and migration is a fundamental process in the cycle of colonization and extinction of the local populations. We ask here whetherPlutella xylostella(Lepidoptera: Yponomeutidae) uses the aging process of the host plant to modulate its migratory activity. The insect was reared in the laboratory on the leaves from the middle estratum (fourth expanded leaves) of cabbage (Brassica oleraceaevar.capitata) of various ages, and on leaves from three strata of the mature plant. Females that spent their larval phase in young and tender plants lived for a shorter period of time and laid eggs immediately after metamorphosis. In contrast, mature plants, particularly the new leaves from the superior stratum, favored the development of adult phenotypic traits that occur in migratory forms, such as reduced body size, increased longevity and delayed reproductive activity. We suggest that the lesser nutritional quality and the short temporal persistence of mature plants are selective forces favoring individuals that are better prepared to abandon their habitat soon after emergence.Plutella xylostellamay use the predictable ontogenetic changes of the ephemeral host plant to modulate its physiological and behavioral migratory ability.
Fungus gnats of the genus Urytalpa Edwards (Diptera: Keroplatidae) in Japan
Authors: UESUGI Kenta 
Published: November 2004

AbstractThree Japanese species of the genus Urytalpa are examined. Urytalpa sapporoensis (Okada) is transferred from Zelmira. Urytalpa yoshidai and U. crassicauda are described as new to science. Morphological characters indicate that U. yoshidai is closely related to Asindulum montanum Röder, and the genus Urytalpa is indicated to be non‐monophyletic. A key to the Japanese species is given.
Secondary host generation of the gall aphid Cerataphis jamuritsu (Homoptera)
Authors: KUROSU Utako , AOKI Shigeyuki , WANG Chuan‐Chan , LEE How‐Jing 
Published: November 2004

AbstractColonies of a Cerataphis species with well‐developed horns were found on the rattan Calamus quinquesstinervis in southern Taiwan. The morphology of first instar nymphs from the colonies accorded well with the morphology of first instar nymphs laid by alates of Cerataphis jamuritsu from galls on Styrax suberifolia, indicating that the rattan aphids are the secondary host generation of C. jamuritsu. Although the aphid colonies were attended by ants, the sharp horns of the first instar nymphs suggest that they might attack predators.
Phylogeography of the leaf beetle Chrysolina virgata in wetlands of Japan inferred from the distribution of mitochondrial haplotypes
Authors: SOTA Teiji , HAYASHI Masakazu , IWAI Daisuke 
Published: November 2004

AbstractThe genetic differentiation among populations of the leaf beetle Chrysolina virgata living in wetlands of Japan was studied based on the sequence data of the mitochondrial cytochrome oxidase subunit I gene region (750 bp). Two distinct lineages of mitochondrial haplotypes were found: one (clade A) consisted of 26 haplotypes distributed over the distribution range of C. virgata between north‐east Honshu and Kyushu, whereas the other (clade B) was monotypic and confined to a small region in north‐east Honshu where it coexisted with clade A. Nested clade analysis for these haplotypes suggested that range expansion and following differentiation due to isolation by distance might have resulted in the present distribution pattern of the haplotypes in clade A. We discuss the evolutionary process leading to the occurrence of two distinct haplotype clades in Japan in terms of repeated colonization from the continent and range expansion and contraction during climatic changes.
Descriptions of two new and one little known species of the genus Cacopsylla (Hemiptera: Psyllidae) on Sorbus japonica (Rosaceae) and an observation of their biology
Authors: INOUE Hiromitsu 
Published: November 2004

AbstractThree species of the genus Cacopsylla were collected from Sorbus japonica in Japan. Two of them, Cacopsylla elegans and Cacopsylla sorbicoccinea, are described as new species based on adults and fifth (final) nymphal instars. The third species, Cacopsylla midoriae, is newly transferred from the genus Psylla. The adult of C. midoriae is redescribed and the nymph is described for the first time. A key to the species feeding on S. japonica (adults and nymphs) is provided. The three species were observed to coexist on the same tree of S. japonica in northern Kyushu. Such coexistence of psylloid congeners is uncommon in Japan.
A methodology using subjective and objective measures to compare plaque inhibition by toothpastes
Authors: Claydon N. , Yates R. , Labello R. , Hall C. , Armstrong R. , Addy M. 
Published: November 2004

AbstractObjectives: Plaque scoring usually employs subjective indices. The aim was to compare plaque inhibition of three toothpastes using two objective and one subjective measures of plaque.Material and Methods: Formulations were: (1) an experimental anti‐plaque paste (test); (2) an experimental paste (minus active or negative control); and (3) a proprietary anti‐plaque toothpaste product (positive control). The study was a blind, randomised crossover design using a 4‐day, no tooth brushing, plaque regrowth model and involving 22 healthy subjects. After baseline plaque removal, subjects rinsed twice a day with slurries of the allocated paste. On day 5, plaque was scored by index, wet weight and optical density of extracted disclosing solution from the plaque (stain intensity).Results: All data showed the same pattern. There were highly significant subject and treatment effects but not period effects. The positive control was highly significantly more effective in plaque control than the test and minus active experimental formulations, which in turn were not significantly different from each other. There were strong and significant correlations between pairs of scoring methods particularly wet weight and stain intensity.Conclusion: The use of objective methods of plaque alongside conventional subjective indices provided convincing evidence for increased discriminatory power in a study comparing plaque inhibition by toothpastes.
Clinical study to compare the effectiveness of a test whitening toothpaste with a commercial whitening toothpaste at inhibiting dental stain
Authors: Claydon N. C. A. , Moran J. , Bosma M. L. , Shirodaria S. , Addy M. , Newcombe R. 
Published: November 2004

AbstractAims: A single centre, randomised single‐blind, three‐way crossover study was performed, to compare the effect of an experimental test toothpaste with a commercially available whitening toothpaste and water control at inhibiting extrinsic stain promoted by repeated chlorhexidine/tea rinses.Methods: This study used 23 subjects. During the week before the study the subjects received a prophylaxis to remove all staining, plaque and calculus deposits. On the Monday of the following week subjects returned to the clinic to receive their rinses and to check their dentition was stain free. Under direct supervision at both 09:00 and 13:00 hours they rinsed with either a toothpaste slurry or water control that was repeated daily up to and including the following Thursday. Additionally from the Monday to the Thursday each subject rinsed with a 0.2% chlorhexidine mouthrinse, immediately followed by a rinse with a warm black tea solution. This cycle was repeated hourly eight times throughout the day and on the following days until the Friday. Throughout this period volunteers omitted all other forms of oral hygiene except rinsing with the chlorhexidine mouthwash. On the Friday the level of stain on the teeth and dorsum of tongue was assessed using the Lobene stain index for both stain area and intensity. At the end of each trial period each subject received a thorough prophylaxis to remove all plaque, calculus and staining before starting the second and third period of the study.Results: As expected appreciable amounts of extrinsic stain accumulated on the teeth over each study period. The amount of stain following use of the toothpastes and water control was least with the experimental toothpaste, followed by water control and lastly the commercial whitening paste. For all sites combined there was evidence that the experimental paste was significantly superior to both the commercial paste and water control at reducing stain area (p<0.001), a product of stain area and intensity (p<0.001 and 0.05, respectively) but not stain intensity (p>0.05).Conclusions: In this stain‐prevention model the use of an experimental paste showed a significant reduction in stain accumulation on the teeth compared with a (placebo) negative water control and a commercially available whitening paste. As such the experimental paste would be expected to be of benefit in controlling extrinsic dental staining.
The effectiveness of a toothpaste containing Triclosan and polyvinyl‐methyl ether maleic acid copolymer in improving plaque control and gingival health
Authors: Davies R. M. , Ellwood R. P. , Davies G. M. 
Published: November 2004

AbstractObjective: To compare the effectiveness of triclosan/copolymer and fluoride dentifrices in improving plaque control and gingival health.Search strategy: We searched the Cochrane Controlled Trials Register, MEDLINE (1986 to March 2003) and EMBASE (1986 to March 2003). Personal files and the reference lists of all articles were checked for further studies.Selection criteria: Trials were selected if they met the following criteria: random allocation of participants; participants were adults with plaque and gingivitis; unsupervised use of dentifrices for at least 6 months; and primary outcomes – plaque and gingivitis after 6 months.Data collection and analysis: Two reviewers independently extracted information. For each plaque and gingivitis index, the mean differences for each study were pooled as weighted mean differences (WMDs) with the appropriate 95% confidence intervals (CIs) using the random effect models.Main results: Sixteen trials provided data for the meta‐analysis. The triclosan/copolymer dentifrice significantly improved plaque control compared with a fluoride dentifrice, with a WMD of −0.48 (95% CI: −0.64 to −0.32) for the Quigley–Hein index and WMD of −0.15 (95% CI: −0.20 to −0.09) for the plaque severity index. When compared with a fluoride dentifrice, the triclosan/copolymer dentifrice significantly reduced gingivitis with WMDs −0.26 (95% CI: −0.34 to −0.18) and −0.12 (95% CI: −0.17 to −0.08) for the Loe and Silness index and gingivitis severity index, respectively.