bluuebunny/crossref_metadata_2025_split huggingface dataset:
Plasma electrolyte concentrations in captive and free‐ranging African penguins (Spheniscus demersus) maintained with and without dietary salt supplements
Authors: Mazzaro Lisa M. , Tuttle Allison , Wyatt Jeff , Goodman Jeremy , Kadyszewski Edmund , Dunn J. Lawrence 
Published: October 2004

AbstractAfrican penguins (Spheniscus demersus) are common display animals in North American zoos and aquariums. At present, 43 American Zoo and Aquarium Association (AZA)‐accredited institutions maintain over 700 of these birds. A survey of facilities found that only seven institutions maintain their birds in “saltwater habitats” (natural, brine, or artificial seawater systems), while the remaining institutions provide freshwater habitats. Penguins maintained in freshwater habitats commonly receive dietary salt supplements, though evidence is lacking as to the value of this practice. This study was designed to evaluate the necessity of salt supplementation in African penguins. We report the results of a randomized, 10‐month comparison of plasma electrolytes (Na, Cl, and K) between groups of 10 salt‐supplemented and nonsupplemented birds living in a freshwater environment. The results showed no significant differences between the two groups. An interfacility comparison at the same time points revealed temporal pattern differences in analyte values between the facilities; however, the absolute concentrations did not exceed clinical ranges found in healthy birds. Furthermore, single time‐point comparisons between wild and captive African penguins indicated similar sodium concentrations, while potassium and chloride concentrations varied between groups. Finally, the plasma electrolyte levels in 20 birds remained statistically unchanged after a 60‐day withdrawal from salt supplementation. This study provides experimental evidence that African penguins maintained in freshwater exhibits on a herring‐, capelin‐, and squid‐based diet do not require salt supplementation. In addition to the practical implications regarding the need for salt supplementation for captive birds, the results also have theoretical significance. They provide evidence that penguins do not need to ingest high salt concentrations to remain in electrolyte balance. In this regard, the ion regulatory mechanisms in penguins are similar to those in terrestrial mammals and birds. Zoo Biol 23:397–408, 2004. © 2004 Wiley‐Liss, Inc.
Stereotypic behavior in Asiatic black and Malayan sun bears
Authors: Vickery Sophie , Mason Georgia 
Published: October 2004

AbstractThe stereotypies of individually caged Asiatic black bears (Ursus thibetanus) and Malayan sun bears (Helarctos malayanus) were studied in detail. Stereotypies were performed by 27 of the 29 subjects, were primarily locomotory in form (e.g., pacing), and occupied on average 18% (standard error of the mean (SEM)=2.5) of daylight hours. Stereotypy levels during the night were almost negligible and were highly correlated with daytime levels. Total stereotypies peaked prior to food arrival, although oral stereotypies were most frequent after feeding. In general, stereotypies were performed in locations from which food arrival could be viewed, although Asiatic black bears were equally likely to exhibit stereotypy near a neighboring bear. Across individuals, stereotypy frequency was inversely correlated with inactivity and increased with age. Older bears also showed less normal activity and a reduced diversity of normal behavior. Stereotypy levels were unrelated to levels of “compulsive” behavior (e.g., hair plucking) or repetitive self‐sucking–a potential deprivation stereotypy. More frequent stereotypies were performed more invariantly (i.e., were more predictable from one repetition to the next) and in more diverse contexts, namely 1) outside the pre‐feeding period, and 2) during the night. Contrary to observations reported elsewhere, higher frequencies of stereotypy were not associated with reduced behavioral diversity, or with a more elaborate repertoire of stereotypy forms and sequences. Although the two species did not differ in overall frequency, the stereotypies of sun bears appeared to be more food‐motivated than those of Asiatic black bears: the sun bears displayed a higher frequency and diversity of oral stereotypies, and higher levels of pre‐feeding stereotypy, and performed significantly more of their total stereotypies in locations from which they could view food arrival. This study demonstrates how analyzing stereotypies in detail can help identify the motivations that underlie these behaviors, and potentially reveal their degree of establishment–both of which are important factors in stereotypy treatment. Zoo Biol 23:409–430, 2004. © 2004 Wiley‐Liss, Inc.
Extracorporeal Photopheresis Differentially Regulates the Expression or Phosphorylated STAT-1 and STAT-5 in Treated Monocytes and T Cells, Respectively
Authors: Bladon John , Taylor Peter 
Published: October 2004

Background Extracorporeal photopheresis (ECP) is effective in conditions with opposing immune etiology. ECP induces an immunomodulatory response through simultaneous monocyte activation and apoptosis induction of lymphocytes. However, ECP is also immunosuppressive, downregulating proinflammatory cytokines. Signal transducers and activators of transcription (STATs) are important mediators of cell-signaling systems, including cytokines. Ultraviolet (UV) immunosuppression is linked to reductions in cytokine-induced STAT phosphorylation. Objective The aim of this study was to find whether ECP downregulates STAT phosphorylation. Methods Pre- and post-ECP mononuclear cells from cutaneous T-cell lymphoma and chronic graft-versus-host disease patients were stimulated with either IFNγ, IL2, or IL15. The percentage of IFNγ-stimulated monocytes positive for phosphorylated STAT-1 (pSTAT-1) and the number of IL2- and IL15-stimulated T cells expressing phosphorylated STAT-5 (pSTAT-5) were determined at 0 and 24 h. Results Post-ECP, pSTAT-1 levels in monocytes remained unchanged; however, at 24 h post-ECP the number of T cells expressing pSTAT-5 was reduced. Conclusion Following ECP, monocytes retain their ability to phosphorylate STAT-1, while pSTAT-5 expression is lost in lymphocytes. This differential effect of ECP may account for the diverse population of diseases that benefit.
The Canadian Dermatology Workforce Survey: Implications for the Future of Canadian Dermatology—Who will be your skin expert?
Authors: Maguiness Sheilagh , Searles Gordon E. , From Lynn , Swiggum Susan 
Published: October 2004

Objective To survey Canadian dermatologists for specialty-specific physician resource information including demographics, workload and future career plans. Background and methods In 2001, the Canadian Dermatology Association (CDA) surveyed 555 dermatologists in Canada to gain specialty-specific physician resource information. Three hundred and seventy-one dermatologists (69%) provided information about themselves, their workloads and their future career goals. Results The average Canadian dermatologist is 52 years old and 35% of practicing dermatologists are over the age of 55. Eighty-nine percent of dermatologists practice in an urban setting, 19% include practice in a rural setting while less than 0.5% practice in remote areas. Canadian dermatologists spend 61% of their clinical time providing services in Medical Dermatology. Within 5 years, 50% of dermatologists reported that they plan to reduce their practices or retire. Conclusion The Canadian Dermatology Workforce Survey provides a snapshot of the current practice of dermatology in Canada. It also serves to highlight the critical shortage of dermatologists, which will continue to worsen without immediate, innovative planning for the future.
Annular Lichen Planus
Authors: Sakakibara Kanako , Nakada Tokio , Sueki Hirohiko , lijima Masafumi , Irisawa Kaikichi 
Published: October 2004

Background Annular lichen planus is a clinical variant of lichen planus, and its characteristic lesions are annular plaques consisting of a narrow rim of activity and a depressed center. Objective This article presents two cases of annular lichen planus, a 39-year-old woman and a 45-year-old woman. Methods and Results In both cases, lesions developed mainly on the femoral regions. Histopathological specimens from the margin of the lesion demonstrated liquefaction degeneration of the epidermis and band-like infiltrate of lymphocytes in the upper dermis, whereas there was very mild infiltrate in the upper dermis from the center. In the center, elastic fibers were more fragmented and less numerous than in the margin. Although topical corticosteroid tape was effective for one case, new lesions developed several times over two years in the other. Conclusion Our findings suggest that this clinical behavior is from elastolysis as a result of inflammation.
Testing the Geometric Clutch hypothesis
Authors: Lindemann Charles B. 
Published: October 2004

Abstract The Geometric Clutch hypothesis is based on the premise that transverse forces (t‐forces) acting on the outer doublets of the eukaryotic axoneme coordinate the action of the dynein motors to produce flagellar and ciliary beating. T‐forces result from tension and compression on the outer doublets when a bend is present on the flagellum or cilium. The t‐force acts to pry the doublets apart in an active bend, and push the doublets together when the flagellum is passively bent and thus could engage and disengage the dynein motors. Computed simulations of this working mechanism have reproduced the beating pattern of simple cilia and flagella, and of mammalian sperm. Cilia‐like beating, with a clearly defined effective and recovery stroke, can be generated using one uniformly applied switching algorithm. When the mechanical properties and dimensions appropriate to a specific flagellum are incorporated into the model the same algorithm can simulate a sea urchin or bull sperm‐like beat. The computed model reproduces many of the observed behaviors of real flagella and cilia. The model can duplicate the results of outer arm extraction experiments in cilia and predicted two types of arrest behavior that were verified experimentally in bull sperm. It also successfully predicted the experimentally determined nexin elasticity. Calculations based on live and reactivated sea urchin and bull sperm yielded a value of 0.5 nN/μm for the t‐force at the switch‐point. This is a force sufficient to overcome the shearing force generated by all the dyneins on one micron of outer doublet. A t‐force of this magnitude should produce substantial distortion of the axoneme at the switch‐point, especially in spoke or spoke‐head deficient motile flagella. This concrete and verifiable prediction is within the grasp of recent advances in imaging technology, specifically cryoelectron microscopy and atomic force microscopy.
Management of breech presentation in areas with high prevalence of HIV infection
Authors: Holmes W.R. , Hofmeyr G.J. 
Published: October 2004

AbstractObjectiveTo provide recommendations for the management of breech presentation in areas of high prevalence of human immunodeficiency virus (HIV) infection.MethodReview of relevant literature.ResultsStudies show that elective cesarean section (CS) is safer than vaginal delivery for breech presentation, external cephalic version (ECV) at term increases the chance of vaginal cephalic delivery. Although there are no studies of the risk of mother‐to‐child transmission of HIV from ECV, indirect evidence suggests that any increased risk is likely to be very small.RecommendationsWhere CS is available and safe, HIV‐positive women, or women who might be at risk of HIV, with a fetus at term with breech presentation, should be offered elective CS to reduce the risks of both vaginal breech delivery and mother‐to‐child HIV infection. HIV‐negative women can be offered ECV at term to try to avoid CS. Where women do not have access to a safe CS, or prefer vaginal delivery, the benefit for both mother and child of attempting ECV at term is likely to outweigh the theoretical, very small, risk of facilitating HIV transmission.
CB1 receptor agonist and heroin, but not cocaine, reinstate cannabinoid‐seeking behaviour in the rat
Authors: Spano M Sabrina , Fattore Liana , Cossu Gregorio , Deiana Serena , Fadda Paola , Fratta Walter 
Published: October 2004

We recently provided evidence for a functional link between cannabinoid and opioid endogenous systems in relapse to heroin‐seeking behaviour in rats. In the present study, we aimed at investigating whether the previously observed cross‐talk between cannabinoids and opioids could be extended to mechanisms underlying relapse to cannabinoid‐seeking behaviour after a prolonged period of abstinence.
In rats previously trained to intravenously self‐administer the synthetic cannabinoid receptor (CB1) agonist WIN 55,212‐2 (12.5 μg kg−1 inf−1) under a fixed ratio (FR1) schedule of reinforcement, noncontingent nonreinforced intraperitoneal (i.p.) priming injections of the previously self‐administered CB1 agonist (0.25 and 0.5 mg kg−1) as well as heroin (0.5 mg kg−1), but not cocaine (10 mg kg−1), effectively reinstate cannabinoid‐seeking behaviour following 3 weeks of extinction.
The selective CB1 receptor antagonist SR 141716A (0.3 mg kg−1 i.p.) does not reinstate responding when given alone, but completely prevents the cannabinoid‐seeking behaviour triggered by WIN 55,212‐2 or heroin primings.
The nonselective opioid antagonist naloxone (1 mg kg−1 i.p.) has no effect on operant behaviour per sè, but significantly blocks cannabinoid‐ and heroin‐induced reinstatement of cannabinoid‐seeking behaviour.
These results provide the first evidence of drug‐induced reinstatement of cannabinoid‐seeking behaviour, and further strengthen previous findings on a cross‐talk between the endogenous cannabinoid and opioid systems in relapse mechanisms to drug‐seeking.

British Journal of Pharmacology (2004) 143, 343–350. doi:10.1038/sj.bjp.0705932
Cardiovascular activity of rasagiline, a selective and potent inhibitor of mitochondrial monoamine oxidase B: comparison with selegiline
Authors: Abassi Zaid A , Binah Ofer , Youdim Moussa B H 
Published: October 2004

Selegiline is used for treating Parkinson's disease. Despite its efficacy, the clinical use of selegiline in combination with L‐dihydroxphenylalanine in Parkinsonian patients is hampered by cardiovascular complications, such as hypotension. This study was designed to compare in rats the cardiovascular effects of selegiline and rasagiline, their metabolites L‐methamphetamine and aminoindan (TVP‐136), respectively, and the second rasagiline metabolite non‐monoamine oxidase (MAO) inhibitor TVP‐1022 (N‐propargyl‐1S(−)aminoindan).
Intravenous (i.v.) administration of selegiline and rasagiline (1 mg kg−1) to anaesthetized rats (thiobutabarbital, 100 mg kg−1, i.p.) did not affect mean arterial pressure (MAP), carotid blood flow (CBF) or carotid vascular resistance (CVR). Selegiline (10 mg kg−1, i.v.) decreased MAP, CBF and increased CVR. In contrast, rasagiline (10 mg kg−1, i.v.) caused a small transient decrease in MAP, while CBF and CVR were unchanged.
L‐methamphetamine (1 mg kg−1, i.v.) administration provoked a dramatic and long‐lasting depressor response, decreased CBF and increased CVR. In contrast, injection of aminoindan or TVP‐1022 at a similar dose produced gradual nonsignificant decreases in MAP and CBF.
Chronic oral treatment (21 days) of awake rats with selegiline at 10 mg kg−1 decreased systolic blood pressure (SBP), diastolic blood pressure (DBP), and MAP, whereas heart rate was unaffected. Since the effective MAO‐B inhibitory and clinical dose of rasagiline is about one‐tenth that of selegiline, administration of 1 mg kg−1 day−1 rasagiline resulted in moderate decreases in SBP, DBP, and MAP, which were significantly lower than those caused by the 10 mg kg−1 day−1 dose of selegiline.
These findings indicate that rasagiline, when given at doses equivalent to selegiline, is less likely to be hypotensive.

British Journal of Pharmacology (2004) 143, 371–378. doi:10.1038/sj.bjp.0705962
Metabolism of Desipramine in Japanese Psychiatric Patients: The Impact of CYP2D6 Genotype on the Hydroxylation of Desipramine
Authors: Shimoda Kazutaka , Morita Sachiyo , Hirokane Genta , Yokono Aya , Someya Toshiyuki , Takahashi Saburo 
Published: October 2004

Abstract:We investigated the impact of the genotype of CYP2D6 on the hydroxylation of desipramine in eighteen patients who were administered desipramine hydrochloride per os. Significantly higher plasma concentration of desipramine/daily dose of desipramine/body weight was observed in the subjects with two mutated alleles than in the subjects with either no mutated alleles or one mutated allele (two mutated alleles versus no mutated alleles=530.4±215.2 versus 118.1±63.9 ng/ml/mg/kg, t=5.68, P<0.001; two mutated alleles versus one mutated allele=530.4±215.2 versus 176.2±62.3 ng/ml/mg/kg, P<0.001; One‐way analysis of variance followed by Bonferroni's multiple comparison test, respectively). Significantly higher ratio of desipramine/2‐hydroxy‐desipramine was observed in the subjects with two mutated alleles compared to subjects with no mutated alleles or the subjects with one mutated allele (two mutated alleles versus one mutated allele=4.39±0.36 versus 2.00±0.64, t=5.12, P<0.001; two mutated alleles versus no mutated alleles=4.39±0.36 versus 2.02±0.59, t=4.42, P<0.01). The genotyping of CYP2D6 only grossly predicts the steady state concentration of desipramine, mainly predicts the risk of getting very high plasma levels. Within each genotype there is marked interindividual variability.
Inhibitory Effects of Silibinin on Cytochrome P‐450 Enzymes in Human Liver Microsomes
Authors: Beckmann‐Knopp Svane , Rietbrock Stephan , Weyhenmeyer Roland , Böcker Ronald H. , Beckurts K. Tobias , Lang Werner , Hunz Miriam , Fuhr Uwe 
Published: October 2004

Abstract:Silibinin, the main constituent of silymarin, a flavonoid drug from silybum marianum used in liver disease, was tested for inhibition of human cytochrome P‐450 enzymes. Metabolic activities were determined in liver microsomes from two donors using selective substrates. With each substrate, incubations were carried out with and without silibinin (concentrations 3.7–300 μM) at 37° in 0.1 M KH2PO4 buffer containing up to 3% DMSO. Metabolite concentrations were determined by HPLC or direct spectroscopy. First, silibinin IC50 values were determined for each substrate at respective KM concentrations. Silibinin had little effect (IC50>200 μM) on the metabolism of erythromycin (CYP3A4), chlorzoxazone (CYP2E1), S(+)‐mephenytoin (CYP2C19), caffeine (CYP1A2) or coumarin (CYP2A6). A moderate effect was observed for high affinity dextromethorphan metabolism (CYP2D6) in one of the microsomes samples tested only (IC50=173 μM). Clear inhibition was found for denitronifedipine oxidation (CYP3A4; IC50=29 μM and 46 μM) and S(−)‐warfarin 7‐hydroxylation (CYP2C9; IC50=43 μM and 45 μM). When additional substrate concentrations were tested to assess enzyme kinetics, silibinin was a potent competitive inhibitor of dextromethorphan metabolism at the low affinity site, which is not CYP2D6 (Ki,c=2.3 μM and 2.4 μM). Inhibition was competitive for S(−)‐warfarin 7‐hydroxylation (Ki,c=18 μM and 19 μM) and mainly non‐competitive for denitronifedipine oxidation (Ki,n=9 μM and 12 μM). With therapeutic silibinin peak plasma concentrations of 0.6 μM and biliary concentrations up to 200 μM, metabolic interactions with xenobiotics metabolised by CYP3A4 or CYP2C9 cannot be excluded.
DNA Adduct Levels and Intestinal Lesions in Congenic Rapid and Slow Acetylator Syrian Hamsters Administered the Food Mutagens 2‐Amino‐1‐methyl‐6‐phenylimidazo[4,5‐b]pyridine (PhIP) or 2‐Amino‐3‐methylimidazo[4,5‐f]quinoline (IQ
Authors: Steffensen Inger‐Lise , Fretland Adrian J. , Paulsen Jan Erik , Feng Yi , Eide Tor Jacob , Devanaboyina Udaya‐Sankar , Hein David W. , Alexander Jan 
Published: October 2004

Abstract:Epidemiological studies indicate that rapid acetylators with a high intake of well‐done red meat have an increased risk of colorectal cancer. Arylamine N‐acetyltransferase enzymes (E.C. 2.3.1.5) activate carcinogenic heterocyclic amines found in the crust of fried meat via O‐acetylation of their N‐hydroxylamines to reactive intermediates that bind covalently to DNA and produce mutations. Syrian hamsters as well as humans express two N‐acetyltransferase isozymes (NAT1 and NAT2) which differ in substrate specificity and genetic control. Nucleic acid substitutions in the NAT2 gene segregate individuals into rapid, intermediate and slow acetylator phenotypes. In the present paper, we examined the role of the polymorphic NAT2 acetylator genotype in carcinogenesis induced by the food mutagens 2‐amino‐1‐methyl‐6‐phenylimidazo[4,5‐b]pyridine (PhIP) or 2‐amino‐3‐methylimidazo[4,5‐f]quinoline (IQ) by comparing Syrian hamster lines congenic at the NAT2 locus. No differences were found between rapid and slow acetylator congenic hamsters in levels of intestinal PhIP‐DNA adducts. In contrast to previous studies in rats, no carcinogen‐related induction of the preneoplastic lesions aberrant crypt foci or tumors was found in the intestines of rapid and slow acetylator congenic Syrian hamsters administered PhIP or IQ.
Human Isolated Coronary Artery Contraction to Sumatriptan Characterised by the Selective 5‐HT1B/1D Receptor Antagonist GR55562
Authors: MaassenVanDenBrink Antoinette , Reekers Marije , Bax Willem A. , Saxena Pramod R. 
Published: October 2004

Abstract:The antimigraine drug, sumatriptan, contracts the human coronary artery both in vivo and in vitro. Because sumatriptan has been associated with cardiac side effects, it is important to characterise the receptor involved in sumatriptan‐induced coronary artery contraction. Using the agonists sumatriptan and 5‐carboxamidotryptamine and the selective 5‐HT1B/1D receptor antagonist GR55562, we have investigated the involvement of 5‐HT1B/1D receptors in the contraction of the human isolated coronary artery. Contractions to sumatriptan (pEC50: 6.1±0.2, maximal effect: 21±4% of 100 mM K+‐induced contraction) were competitively antagonised by GR55562. The pA2 of GR55562 (7.40±0.16) was in accord with its reported affinity at the human 5‐HT1B receptor. Since the contractions to 5‐carboxamidotryptamine did not reach a maximum with the highest concentration used (10 μM), pEC50 values could not be calculated for Schild analysis. However, using the pEC10%K+ values (negative logarithm of the concentration needed to induce 10% of the contraction to 100 mM K+), GR55562 proved a less potent antagonist against 5‐carboxamidotryptamine than against sumatriptan. These results show that sumatriptan contracts the human isolated coronary artery via 5‐HT1B/1D receptors, most probably the 5‐HT1B subtype. 5‐Carboxamidotryptamine may contract the human isolated coronary artery, at least partly, via a novel yet to be characterised, receptor.