bluuebunny/crossref_metadata_2025_split huggingface dataset:
OBSERVATION OF SAND‐DWELLING TOXIC DINOFLAGELLATES (DINOPHYCEAE) FROM WIDELY DIFFERING SITES, INCLUDING TWO NEW SPECIES
Authors: Faust Maria A. 
Published: October 2004

ABSTRACT Dinoflagellate associations, including toxic and potentially toxic benthic species, were examined in sand from South Water Cay and Carrie Bow Cay, Belize. The inshore sand habitat in localized areas of warm shallow lagoonal waters supported blooms of toxic assemblages of dinoflagellates. In the sand, the dominant microalgae were dinoflagellates; cyanobacteria were a minor component and diatoms were absent. Ciliates and nematodes were present. Assemblages of microorganisms in colored sand were examined for 4 consecutive days after which a storm washed away the patch. The sand‐dwelling dinoflagellate assemblage included 16 species where densities ranged from as low as 1.3% to 15% of total cell densities. The dominant species was Scrippsiella subsalsa, having 1.8 × 105 to 2.6 × 105 cells g‐1 sand. Toxic dinoflagellates identified in the sand were Gambierdiscus toxicus, Ostreopsis lenticularis, Prorocentrum lima, Prorocentrum mexicanum, and Amphidinium carteri. The potentially toxic Ostreopsis labens, Gambierdiscus belizeanussp. nov., and Coolia tropicalis sp. nov. were also identified. Toxic and potentially toxic species represented 36% to 60% of total microalgal cell assemblage. The morphology of a new sand‐dwelling species, Gambierdiscus belizeanus sp. nov., was examined with the scanning electron microscope. The plate formula was Po, 3′, 7″, 6c, s?, 5‴, 1p, and 2″″.Dimensions of G. belizeanus cells were 53–67 pm long, 54–63 μm wide, and 92–98 μm in dorsoventral depth. Cells were deeply areolated, ellipsoid in apical view, and compressed anteroposteriorly. The cells of G. belizeanus were identified by the cell's long, narrow, pentagonal, posterior intercalary plate (1p) wedged between the wide postcingular plates 2″’and 4″; 1p occupied 20% of the width of the hypotheca. The plate formula for Coolia tropicalis sp. nov. was Po, 3′, 7″, 7c, 8s?, 5″″, and 2″″, Cell size ranges were 23–40 μm long, 25–39 μm wide, and 35–65 μm in dorsoventral diameter. Cells were spherical, smooth, and covered with scattered round pores. The epitheca was smaller than the hypotheca. Precingular plates 1″ and 7″ were small and narrow, and the first apical plate 1″ and precingular plate 6″ were the largest plates on the epitheca. The apical pore was straight and 7 μm long, and was situated in the apical plate complex. Cells of C. tropicalis were distinguished from C. monotis by the wedge‐shaped plate 1′, a four‐sided 3’plate, and a short apical pore.
GENETIC TRANSFORMATION OF THE DIATOMS CYCLOTELLA CRYPTICA AND NAVICULA SAPROPHILA
Authors: Dunahay Terri G. , Jarvis Eric E. , Roessler Paul G. 
Published: October 2004

ABSTRACT Two species of diatoms were genetically transformed by introducing plasmid vectors containing the Escherichia coli neomycin phosphotransferase II (nptII)gene. Expression of the bacterial nptII gene in the diatoms was achieved using the putative promoter and terminator sequences from the acetyl‐CoA carboxylase gene from the centric diatom Cyclotella cryptica T13L Reimann, Lewin, and Guillard. The vectors were introduced into C. cryptica and the pennate diatom Navicula saprophila NAVIC1 Lange‐Bertalot and Bonik by microprojectile bombardment. Putative transformants were selected based on their ability to grow in the presence of the antibiotic G418, and production of the neomycin phosphotransferase protein by the transformed cells was confirmed by western blotting. The foreign DNA integrated into one or more random sites within the genome of the transformed algal cells, often in the form of tandem repeats. This is the first report of reproducible, stable genetic transformation of a chlorophyll c‐containing alga.
A NEW, NONRADIOACTIVE WHOLE‐MOUNT IN SITU HYBRIDIZATION PROTOCOL FOR FUCUS (PHAEOPHYTA) EMBRYOS
Authors: Bouget François‐Yves , Gerttula Suzanne , Kloareg Bernard , Quatrano Ralph S. 
Published: October 2004

ABSTRACT We present a nonradioactive protocol to localize mRNA in Fucus distichus ssp. edentatus (de la Pyl.) Powell (Phaeophyta) embryos using whole‐mount in situ hybridization. Hybridization of a digoxygenin (DIG)‐labeled oligo‐dT probe to poly A+ RNA, and DIG‐labeled riboprobes to specific mRNAs, was detected with an antibody to DIG (anti‐DIG) that was coupled to alkaline phosphatase. Our protocol, a modification of one developed for higher plants, includes a treatment of fixed embryos with specific cell‐wall‐degrading enzymes to permeabilize the cells to anti‐DIG, progressive osmotic changes to prevent plasmolysis, and a RNase A treatment to reduce nonspecific background. Using this protocol, we show the intracellular distribution of poly A+ RNA and mRNAs for actin and the fucoxanthin chlorophyll protein A (Fcp A). This method to detect mRNA localization is rapid because it does not require embedding, sectioning, or the use of radioactivity. With the availability of a variety of enzymes to degrade plant cell walls, this protocol should be applicable to many algal cells.
Comparison of regional vasomotor responses to acetazolamide and CO2 in rabbit cerebrum and cerebellum, measured by a hydrogen clearance method
Authors: Csete K. , Vezekényi Z. , Dóczi T. , Papp J. Gy. , Bodosi M. , Barzó P. 
Published: October 2004

AbstractAim:  Many investigators have proved the usefulness of acetazolamide provocation and the carbon dioxide test for assessment of the local cerebrovascular reactivity by measurement of the regional cerebral blood flow in patients with occlusive cerebrovascular disease. Data originating from a comparison of these two different vasomotor stimuli as concerns the differences in sensitivity to them in various parts of the central nervous system are scarce. Our aim was to compare the cerebral blood flow responses to hypercapnic and acetazolamide stimuli in different brain regions.Methods:  The cerebral blood flow was measured in the cerebrum (cortex and caudate nucleus) and cerebellum (cortex), as measured by a hydrogen clearance method in anaesthetized, artificially ventilated rabbits.Results:  In normocapnia, the cerebral blood flow values in the cerebrum and the cerebellum differed significantly. The cerebral blood flow responses to both vasodilatory stimuli were to be significantly higher in the cerebrum than in the cerebellum, but the relative increases, i.e. the mean relative reactivities, were similar in the different regions measured.Conclusion:  The regional dissimilarity might explain to some extent the different sensitivities of the various brain areas to sudden blood pressure changes (infarction or haemorrhage). The results further suggest that heterogeneity in cerebrovascular reactivity should be considered in the assessment of vasoreactivity in patients with occlusive cerebrovascular disease. Since the comparison of the carbon dioxide and acetazolamide – induced cerebrovascular reactivities revealed a strong linear relationship, it was concluded that acetazolamide provocation is equivalent to the carbon dioxide test in the evaluation of cerebrovascular reactivity.
Partial reversal of conduction slowing during repetitive stimulation of single sympathetic efferents in human skin
Authors: Campero M. , Serra J. , Bostock H. , Ochoa J. L. 
Published: October 2004

AbstractAims:  To describe and identify the function of a class of human C fibre with an unusual response to repetitive electrical stimulation. Other C fibres slow progressively at 2 Hz (type 1), reach a latency plateau (type 2) or hardly slow at all (type 3).Methods:  C fibres innervating hairy skin were recorded by microneurography in the superficial peroneal nerves of 19 healthy volunteers. Baseline electrical stimulation of the skin was at 0.25 Hz, and activity‐dependent slowing recorded during stimulation at 2 Hz for 3 min and after a 3‐min pause in stimulation.Results:  In 41 units, there was a partial recovery of latency during repetitive stimulation. These were classified as ‘type‐4’ units, and identified as sympathetic efferents, since they exhibited spontaneously activity, which was enhanced by manoeuvres that increase sympathetic outflow (15 of 16 cases) and/or suppressed by a proximal anaesthetic block (eight of eight cases). The peak slowing during 2 Hz trains averaged 6.47 ± 2.06% (mean ± SD, n = 41), but after 3 min the slowing had reduced to 4.90 ± 2.20%, which was less than in all type 1 (nociceptor) fibres but similar to that in type 2 (cold) fibres. Compared with cold fibres, type‐4 sympathetic fibres slowed more after the first 10 impulses at 2 Hz (2.57 ± 0.45%) and also after a pause in stimulation (1.66 ± 0.51%).Conclusions:  The distinctive activity‐dependent slowing profiles of these type‐4 sympathetic C units may help identification in vitro, and suggest that hyperpolarization‐activated channels have a particularly prominent role in the axonal membrane.
Human motor compensations for thixotropy‐dependent changes in muscular resting tension after moderate joint movements
Authors: Axelson H. W. 
Published: October 2004

AbstractAim: This study on healthy subjects explores history‐dependent changes in the resting tension of relaxed wrist muscles after moderate joint excursions and the motor control consequences of these changes during voluntary wrist joint position maintenance.Methods: Integrated surface electromyogram (IEMG) was recorded from wrist extensor/flexor muscles. Angular position and torque were recorded from the wrist joint. Changes in wrist flexor muscle resting tension were sensed by a force transducer pressed against the tendons.Results: Consecutive stepwise changes (7.5°) in wrist joint position (within the dorsiflexed range) were either imposed on relaxed subjects or actively performed while the subjects under visual guidance tried to mimic the passive movements. In relaxed subjects, passive joint torque resistance at a given steady dorsiflexed position either gradually declined or rose depending on the direction of the previous transition movements. In corresponding voluntary contraction experiments, the IEMG amplitude from position holding wrist extensors was found to vary in a similar way as the passive torque resistance. Further, there was a strong correlation between history‐dependent changes in extensor IEMG amplitude and stress alterations exhibited by the relaxed antagonist flexors. The above described, slowly subsiding post‐movement mechanical and motor adaptations were accelerated by brief forceful cocontractions of the forearm muscles.Conclusion: Moderate stepwise changes in joint position are sufficient to induce history‐dependent after‐effects in passive muscular resting tension, after‐effects which during voluntary position holding are effectively compensated for by the motor control system.
Control of oxygen transport in the microcrustacean Daphnia: regulation of haemoglobin expression as central mechanism of adaptation to different oxygen and temperature conditions
Authors: Paul R. J. , Zeis B. , Lamkemeyer T. , Seidl M. , Pirow R. 
Published: October 2004

AbstractThe pathway for oxygen, the control of oxygen transport and the role of haemoglobin expression for the physiological adaptation to different oxygen and temperature conditions were studied in the ecological model organism Daphnia magna. Ventilation of the inner walls of the carapace as the main gas exchange area as well as of the embryos in the brood pouch are controlled, oxygen‐dependent processes. The PO2‐dependent increase of heart rate as well as perfusion rate during short‐term, progressive hypoxia improves the circulatory oxygen transport within the body. The regulation of haemoglobin (Hb) expression is the central mechanism for a medium‐term adaptation to hypoxia. Genetic control elements and oxygen conditions near the two Hb synthesis sites (fat cells, epipodite epithelial cells) determine, which types of Hb subunits and, accordingly, hetero‐multimeric Hb macromolecules are produced. One synthesis site may respond mainly to internal, the other one to external oxygen conditions. Depending on environmental condition, either higher quantities of macromolecules of unchanged functionality (P50) or increasing amounts of macromolecules with higher oxygen affinity are synthesized. The Hb subunit DmHbA is probably of considerable importance for this functional change. The physiological benefits of haemoglobin in Daphnia are discussed. Physiological adaptation of Daphnia to different temperatures is also related to the control of oxygen transport processes with the regulation of haemoglobin expression again as a central mechanism.
Review article: relationship between the metabolism and efficacy of proton pump inhibitors – focus on rabeprazole
Authors: Horn J. 
Published: October 2004

SummaryProton pump inhibitors are now considered the mainstay of treatment for acid‐related disease. Although all proton pump inhibitors are highly effective, the antisecretory effects of different drugs in this class are not completely consistent across patients. One reason for this is the acid‐suppressing effect of Helicobacter pylori infection, which may augment the actions of proton pump inhibitors. A second important reason for interpatient variability of the effects of proton pump inhibitors on acid secretion involves genetically determined differences in the metabolism of these drugs. This article focuses on the impact of genetic polymorphism of cytochrome P450 (CYP)2C19 on the pharmacokinetics and pharmacodynamics of proton pump inhibitors, particularly rabeprazole. Results reviewed indicate that the metabolism and pharmacokinetics of rabeprazole differ significantly from those of other proton pump inhibitors. Most importantly, the clearance of rabeprazole is largely nonenzymatic and less dependent on CYP2C19 than other drugs in its class. This results in greater consistency of pharmacokinetics for rabeprazole across a wide range of patients with acid‐related disease, particularly those with different CYP2C19 genotypes. The pharmacodynamic profile for rabeprazole is also characterized by more rapid suppression of gastric acid secretion than with other proton pump inhibitors, which is also independent of CYP2C19 genotype. The favourable pharmacokinetic/pharmacodynamic profile for rabeprazole has been shown to result in high eradication rates for H. pylori in both normal and poor metabolizers. Pharmacodynamic results have also suggested that rabeprazole may be better suited than omeprazole as on‐demand therapy for symptomatic gastro‐oesophageal reflux disease. Finally, the use of rabeprazole is not complicated by clinically significant drug–drug interactions of the type that have been reported for omeprazole.
Review article: pH, healing and symptom relief with rabeprazole treatment in acid‐related disorders
Authors: Robinson M. 
Published: October 2004

SummaryControl of gastric acid secretion by antisecretory agents has been the cornerstone of therapy in the successful management of all acid‐related disorders, including gastro‐oesophageal reflux disease (GERD), and duodenal and gastric ulcer. Treatment efficacy has been strongly correlated with degree and duration of acid suppression within the 24‐h period and with total duration of therapy. All proton pump inhibitors are highly effective for the healing of ulcers and erosive oesophagitis. All have closely similar mechanisms of action, yet important pharmacological differences exist, which can significantly impact certain aspects of their clinical efficacy. Rabeprazole's rapid activation over a wide pH range may be the explanation for its early onset of effective acid inhibition compared with other proton pump inhibitors such as omeprazole, lansoprazole and pantoprazole. Like rabeprazole, esomeprazole is also a potent inhibitor of gastric acid at steady state, although it is thought that rabeprazole may provide enhanced first‐day acid suppression compared with esomeprazole. First‐day antisecretory efficacy should produce faster symptom relief, a hypothesis supported by clinical data. Moreover, drugs with pharmacological profiles that include both rapid onset and potent antisecretory effects should help control healthcare costs by reducing the need for otherwise commonly used twice‐daily proton pump inhibitor administration.
Obstacles in large‐scale epidemiological assessment of sensory impairments in a Dutch population with intellectual disabilities
Authors: Evenhuis H. , Van Splunder J. , Vink M. , Weerdenburg C. , Van Zanten B. , Stilma J. 
Published: October 2004

AbstractBackground  A population‐based epidemiological study on visual and hearing impairment was planned in a random sample of 2100 clients, drawn from a base population of 9012 users of Dutch residential and day‐care intellectual disability (ID) services with the whole range of IDs. Stratification was applied for age 50 years and over and Down syndrome. Visual and hearing functions were assessed according to a standardized protocol, in cooperation with regular ophthalmologists and regional audiological centres. Anticipated obstacles in sample collection, random inclusion, informed consent, expertise of investigators, time and costs were eliminated by a careful preparation. However, inclusion and participation were incomplete.Method  In a descriptive retrospective design, we collected data from our study files on inclusion and participation as well as reasons for non‐participation, to identify unanticipated obstacles for this kind of research.Results  Consent was obtained for 1660 clients, and 1598 clients participated in the data collection (76% of intended sample of 2100). Inclusion and participation rates were especially lower in community‐based care organizations, resulting in unintentional skewing of the sample towards more severe levels of ID. Complete and reliable data to diagnose visual impairment were obtained for 1358/1598 (85%) and to diagnose hearing impairment for 1237/1598 participants (77%). Unanticipated obstacles had to do with the quality of coordination within care organizations, with characteristics of screening methods, and with collaboration with the regular health care system. Assessments of visual function were more easy to organize than were those of hearing. Based on our current experience, practical recommendations are given for future multicentre research, especially in community‐based settings.
Improving functional skills and physical fitness in children with Rett syndrome
Authors: Lotan M. , Isakov E. , Merrick J. 
Published: October 2004

AbstractBackground  To investigate the feasibility of a physical exercise programme with treadmill for persons with Rett syndrome (RS) in order to promote fitness and health.Methods  A daily training programme on a treadmill was designed for four females with RS over a period of 2 months with tests performed in three intervals, at time 1, 2 and 3, 2 months apart with intervention taking place between tests 2 and 3. Participants were four girls with RS aged 8.5–11 years (mean: 10 years) attending the educational facility Beit Issie Shapiro, Raanana, Israel, all with independent mobility and with typical characteristics of RS stage III. The training took place at the educational facility, on a 1400 model treadmill (Trimline, capable of very low speeds < 0.5 k/h), with very long side rails. Special low side rails were adapted to the treadmill in order to fit the height of the children and velcro straps were added to assist in safely placing the hands. Pulse was monitored constantly during exercise by an A3 polar pulse belt. Pulse measurements at rest during training were considered as evaluators of aerobic physical condition. Functional measurement was based on a scale specially established for the present study. The scale was a 31‐item motor‐functioning tool that measures the ability of participants to knee walk and knee stand, to get up to a standing position, duration of walking different paths, and to go up and down stairs and slopes.Results  The study showed that physical fitness of the children at the end of the training programme had improved considerably (P < 0.05). Tests showed that general functional abilities had improved considerably (P < 0.0001). Although all items of the functional ability measure showed impressive positive change, some of the 31 items on it showed statistically significant improvement (knee walking, going up and down stairs and speed of walking for 25 m. Pearson correlation showed high linkage (r = −0.76) between functional improvement and change in physical fitness.Conclusions  Physical fitness programme executed on a daily basis is capable of improving functional ability of children with RS. Nonprofessional personnel can execute such a programme under supervision of a qualified physical therapist.
Attitude to medication of parents/primary carers of people with intellectual disability
Authors: Rasaratnam R. , Crouch K. , Regan A. 
Published: October 2004

AbstractObjective  To investigate the influence of attitudes of carers of people with intellectual disability (ID) towards giving medication.Method  Ninety‐three carers of service users who are currently attending outpatients clinic (Harrow Learning Disability service) were interviewed, using the RAMS (Rating of Attitude to Medication Scale) interview schedule.Results  A significant association was found between relationship of the carer to the service user and overall positive or negative attitude towards medication, with a disproportionate number of parents expressing a negative attitude in comparison with professional carers (46% vs. 11%).Conclusion  This study suggests more work needs to be done with family carers than with professional carers to improve compliance with medication. Stigma is still associated with ID and psychiatric disorders. The family carers responses may be projecting their feelings related to the impact of having a child not only with ID, but also with additional psychiatric problems. The implication of the study for psychiatrists is the identification of a number of areas that could be usefully explored before writing a prescription.