bluuebunny/crossref_metadata_2025 huggingface dataset:
Changes in the fish fauna of the Ria de Aveiro estuarine lagoon (Portugal) during the twentieth century
Authors: Pombo L. , Elliott M. , Rebelo J. E.
Published: April 2005

The fish biodiversity of the Ria de Aveiro has been analysed during the 20th century, as an indicator of the biological integrity of the ecosystem. Ninety‐two distinct species and 38 families of Agnatha, Chondrichthyes and Osteichthyes occurred during the period. The family and species richness showed two levels of magnitude, from the 1910s, with high values (26–28 families and 51–52 species), and during the last two decades with more variable values (20–27 families and 38–55 species). A total of 13 species (four non‐sporadic species) have disappeared recently. The lagoon system has been affected by large‐scale anthropogenic influences mainly the substantial development of industries and the increasing population in the watershed, in addition to overfishing, climatic changes and dredging. In general, as shown by an analysis of the ecotrophic guilds present, the area maintained a similar structure during the whole period. No significant differences in time were recorded for any of the designated guilds. The twenty‐two frequent species, which occurred in six or seven surveys, were mainly estuarine resident species or marine adventitious species, living in the substratum (benthic fish), on soft substratum and vegetated bottoms. They were feeding either on invertebrates alone or on invertebrates and fish, and producing pelagic or benthic eggs. The 19 sporadically‐recorded species, recorded only once, were mostly marine adventitious, demersal fishes, living above rough bottom and vegetation, feeding strictly on invertebrates, and producing eggs benthically or deposited into vegetation. It is concluded that the Ria de Aveiro estuarine coastal lagoon has supported similar fish communities during the past century and that these comprise representatives of various ecological types.
Fishes as indicators of environmental and ecological changes within estuaries: a review of progress and some suggestions for the future
Authors: Whitfield A. K. , Elliott M.
Published: April 2005

Estuarine habitats, and the fish assemblages associated with them, are potentially impacted upon by many anthropogenic influences which can have a direct influence on the food resources, distribution, diversity, breeding, abundance, growth, survival and behaviour of both resident and migrant fish species. The direct and indirect coupling between ichthyofaunal communities and human impacts on estuaries reinforces the choice of this taxonomic group as a biological indicator that can assist in the formulation of environmental and ecological quality objectives, and in the setting of environmental and ecological quality standards for these systems. This review examines the rationale and value of selecting fishes as bio‐indicators of human induced changes within estuaries, using examples from both the northern and southern hemispheres. The monitoring of estuarine ‘health’ using fish studies at the individual and community level is discussed, with an emphasis on the potential use of estuarine fishes and their monitoring and surveillance in national and international management programmes. In illustrating the above concept, examples are presented of the way in which fishes are threatened by anthropogenic impacts and of the way in which teleosts can contribute to a monitoring of estuarine ecosystem health.
Recent increase of North Sea houting and prospects for recolonization in the Netherlands
Authors: Kranenbarg J. , Winter H. V. , Backx J. J. G. M.
Published: April 2005

Two monitoring programmes in estuarine and freshwater systems in the Netherlands both show a recent increase in anadromous North Sea houting Coregonus oxyrhynchus after it disappeared there in the 1940s. Most houting were immature and caught during the feeding season indicating that at present the riverine and estuarine waters in the Netherlands mainly function as a feeding habitat.
Review article: current management of renal dysfunction in the cirrhotic patient
Authors: Pham P.‐T. T. , Pham P.‐C. T. , Rastogi A. , Wilkinson A. H.
Published: April 2005

The United Network for Organ Sharing database revealed that over the last 4–5 years, an average of 1800 patients were removed from the cadaveric waiting list annually because of patients’ death and an additional 400–500 were removed from the list because of the severity of their illnesses.1 The pre‐transplant evaluation process, therefore, requires careful and continued assessment of the patient's pulmonary, cardiac and renal function among others.

This article describes a systematic approach to the evaluation and management of renal dysfunction complicating the course of advanced liver disease, the pathogenic mechanisms and current recommendations for the treatment of hepatorenal syndrome, and the indications for combined liver–kidney transplantation.
Is the management of hepatitis C patients appropriate? A population‐based study
Authors: Hatem C. , Minello A. , Bresson‐Hadni S. , Jooste V. , Evrard P. , Obert B. , Lepage C. , Bonithon‐Kopp C. , Faivre J. , Monnet E. , Miguet J.‐P. , Hillon P. ,   The Rebohc and Revhoc Committees
Published: April 2005

Background : In order for hepatitis C patients to receive antiviral treatment, they must reach medical care.

Aim : To assess the proportion of patients reaching medical care after hepatitis C diagnosis in a general population (1 006 171 inhabitants) in France.

Methods : Between 1994 and 1999, 1508 cases were diagnosed, of which 1251 were eligible for the study.

Results : Two‐hundred and two patients did not have any medical care; among them, 55.4% had normal alanine transferase, 58.4% had risk factors related to lifestyle and 22.8% were alcoholics. Amongst the 1049 other patients, 41.6% had a liver biopsy, 25.0% were treated. Treatment was more often carried out in males than in females (OR: 1.59; P = 0.001), and in patients under 65 than in older patients (OR: 2.22; P < 0.008). Among non‐treatment reasons, alcoholism (P = 0.001), drug‐addiction (P = 0.04) and escaping monitoring (P = 0.04) were more frequent in males than in females, whereas normal alanine transferase was more frequent in females than in males (P = 0.004). Amongst 278 patients with a Metavir score >A1F1, 71 (25.5%) did not undergo treatment.

Conclusion : In a general population, one patient in six did not receive on‐going health care; a quarter of patients with a Metavir score >A1F1 did not receive any treatment. These results showed insufficient clinical management, which could compromise the effectiveness of treatment in general population.
Review article: current management of primary sclerosing cholangitis
Authors: Cullen S. N. , Chapman R. W.
Published: April 2005

The management of primary sclerosing cholangitis (PSC) is hindered by incomplete understanding of the pathogenesis of the disease and the lack of good prognostic models. Few large randomized controlled trials of drug therapy have been published. Best practice in the management of PSC is currently based therefore on careful interpretation of the available evidence, close observation of individual patients and clinical experience of the disease. Drug therapy is useful for alleviating symptoms. Ursodeoxycholic acid may slow progression of the disease and reduce the frequency of complications. Consensus is emerging on the issues of screening for the malignant complications of PSC and the indications for liver transplantation are becoming broader and encompassing the earliest stages of cholangiocarcinoma. In view of the rarity of the disease in the general population, large international collaborations to study PSC are necessary to provide clearer answers in areas of uncertainty, and these are now beginning to emerge.
Long‐term follow‐up of Helicobacter pylori eradication therapy in Vietnam: reinfection and clinical outcome
Authors: Wheeldon T‐U. , Hoang T. T. H. , Phung D. C. , Björkman A. , Granström M. , Sörberg M.
Published: April 2005

Aim : To assess the long‐term Helicobacter pylori reinfection rates, as well as the clinical outcome in peptic ulcer disease patients in Vietnam.

Method : At a 1‐year evaluation of H. pylori eradication treatment in 226 peptic ulcer patients, long‐term H. pylori status was assessed with serology and/or culture, peptic ulcer status by gastroscopy, and DNA‐fingerprinting performed with random amplified polymorphic DNA and restriction fragment polymorphism.

Result : Follow‐up was performed a mean 11 months after the post‐treatment evaluation on day 30 after beginning of treatment. The overall reinfection rate was 23.5%, with 58.8% of the strains being identical to the pre‐treatment isolates and 41.2% being different. Peptic ulcer was found in 22.9% of the reinfected patients and in 6.3% of the non‐reinfected. At the long‐term follow‐up of successful eradication cases, 89.8% of the patients were free of peptic ulcer disease. The corresponding result was 58.7% in patients in whom H. pylori eradication failed.

Conclusion : Following successful H. pylori eradication, reinfection with H. pylori in patients in Vietnam was found to be higher than in industrialized countries but the long‐term recurrence of peptic ulcer disease was still low. Helicobacter pylori eradication treatment is therefore of value also in developing countries as the rate of peptic ulcer disease was low at the 1‐year follow‐up.
Review article: smoking cessation as primary therapy to modify the course of Crohn's disease
Authors: Johnson G. J. , Cosnes J. , Mansfield J. C.
Published: April 2005

This article aims to offer an updated review of the effects of smoking on inflammatory bowel disease, and provide a review of the methods of achieving smoking cessation. A systematic review of Embase and Medline databases was conducted. Smoking causes opposing effects on ulcerative colitis and Crohn's disease. The odds ratio of developing ulcerative colitis for smokers compared with lifetime non‐smokers is 0.41. Conversely, smokers with Crohn's disease have a more aggressive disease requiring more therapeutic intervention. Smoking cessation is associated with a 65% reduction in the risk of a relapse as compared with continued smokers, a similar magnitude to that obtained with immunosuppressive therapy. Although difficult to achieve smoking cessation can best be encouraged by accessing appropriate counselling services, nicotine replacement therapy and bupropion. Using a combination of these treatments there is an improved chance of success of up to 20% compared with an unassisted quit attempt. Smoking cessation unequivocally improves the course of Crohn's disease and should be a primary therapeutic aim in smokers with Crohn's disease.
A controlled trial of ondansetron in the pruritus of cholestasis
Authors: O'Donohue J. W. , Pereira S. P. , Ashdown A. C. , Haigh C. G. , Wilkinson J. R. , Williams R.
Published: April 2005

Background : In patients with pruritus of cholestasis, response to conventional drug treatment may be unsatisfactory. Activation of 5‐hydroxytryptamine receptors on dermal sensory nerve‐endings plays a role in the perception of pruritus. The 5‐hydroxytryptamine3 receptor antagonist, ondansetron, has been used in the treatment of pruritus of cholestasis, but there are few controlled data.

Aim : To determine whether ondansetron is effective in treating the pruritus of cholestasis.

Methods : A total of 19 patients with resistant pruritus were randomized, double blind, to receive either ondansetron 8 mg or placebo as a single intravenous bolus, followed by oral ondansetron 8 mg or placebo twice daily for 5 days. Patients’ perception of pruritus was recorded hourly using a visual analogue scale, and scratching activity measured by means of a piezo‐electric crystal attached to the fingernail.

Results : Mean pruritus score using visual analogue scale and scratching activity were reduced on the first treatment day compared with baseline in both the ondansetron and placebo groups (P < 0.05), but there were no significant differences in mean pruritus perception or scratching activity between the two groups.

Conclusion : Ondansetron was of no benefit in this group of pruritic patients during short‐term treatment.
Controlled trial of interventions to increase testing and treatment for Helicobacter pylori and reduce medication use in patients with chronic acid‐related symptoms
Authors: Majumdar S. R. , Ross‐Degnan D. , Farraye F. A. , Lee M. , Kemp J. A. , Lecates R. F. , Henning J. M. , Tunis S. R. , Schrammel P. , Soumerai S. B.
Published: April 2005

Background : Many symptomatic patients take proton pump inhibitors or histamine‐2 blockers for years and those without gastro‐oesophageal reflux disease might benefit from Helicobacter pylori eradication.

Aim : To increase testing and treatment of H. pylori and reduce chronic use of proton pump inhibitors and histamine‐2 blockers.

Methods : We conducted a three‐armed controlled trial in 14 managed care practices. We included adults who used proton pump inhibitors or histamine‐2 blockers for >1 year and excluded those with gastro‐oesophageal reflux disease or previous endoscopy. We compared usual care (n = 312 patients from 6 practices) to low‐intensity (n = 147 from 3 practices) and high‐intensity (n = 122 from 5 practices) interventions. Low‐intensity intervention consisted of guidelines, patient‐lists, and a ‘toolkit’; high‐intensity intervention added academic group detailing by a gastroenterologist with reinforcement by pharmacists.

Results : Compared with usual care, the high‐intensity intervention increased H. pylori test‐ordering (29% versus 9% at 12 months, P = 0.02). About half (23 of 58) of patients tested positive and 22 received eradication treatments. The high‐intensity intervention decreased proton pump inhibitor use by 9% per year (P = 0.028), but did not alter histamine‐2 blocker use. The low intensity intervention was ineffective.

Conclusions : Providing guidelines, patient‐lists, and toolkits was no better than usual care. Adding group detailing and pharmacist reinforcements led to improvements in H. pylori management and decreases in proton pump inhibitor use.
Intragastric acidity during treatment with esomeprazole 40 mg twice daily or pantoprazole 40 mg twice daily – a randomized, two‐way crossover study
Authors: Miehlke S. , Madisch A. , Kirsch C. , Lindner F. , Kuhlisch E. , Laass M. , Knoth H. , Morgner A. , Labenz J.
Published: April 2005

Background : Patients with severe or complicated reflux disease may require higher than standard doses of a proton pump inhibitor for sufficient acid suppression.

Aim : To test the hypothesis that esomeprazole 40 mg twice daily is superior to pantoprazole 40 mg twice daily in lowering intragastric acidity.

Methods : In a randomized, single‐blinded, two‐way crossover study, healthy subjects received esomeprazole 40 mg twice daily or pantoprazole 40 mg twice daily orally for five consecutive days. Continuous ambulatory 24‐h intragastric pH was recorded on day 5 of each treatment.

Results : Thirty subjects were analysed. Esomeprazole provided significantly higher intragastric pH‐values over the 24‐h period [median intragastric pH 6.4 for esomeprazole and 5.1 for pantoprazole (P < 0.00005)]. Intragastric pH > 4 was maintained for 21.1 h with esomeprazole and 16.8 h with pantoprazole (P < 0.0001). An intragastric pH > 4 for more than 16 h was achieved in 96.7 and 56.7% of subjects, respectively (P = 0.0002). During night‐time the proportion of time with intragastric pH > 4 was 85.4% with esomeprazole and 63.6% with pantoprazole (P = 0.0001). Nocturnal acid break through occurred less frequently on esomeprazole.

Conclusions : Esomeprazole 40 mg twice daily provides better and more consistent intragastric acid control than pantoprazole 40 mg twice daily.
Anxiety, depression and psychotropic medication use in patients with persistent upper and lower gastrointestinal symptoms
Authors: van Kerkhoven L. A. S. , van Rossum L. G. M. , van Oijen M. G. H. , Witteman E. M. , Jansen J. B. M. J. , Laheij R. J. F. , Tan A. C. I. T. L.
Published: April 2005

Background:  Limited information is available about anxiety, depression and psychotropic medication use in patients referred for gastrointestinal endoscopy.

Aim:  To determine anxiety and depression and its association with endoscopic findings in a representative sample of patients with persistent gastrointestinal symptoms prior to endoscopy.

Methods:  Patients referred to the hospital for endoscopy between February 2002 and February 2004 were asked to score anxiety and depression on the Hospital Anxiety and Depression Scale 2 weeks prior to endoscopy. Information about endoscopic diagnoses was obtained from medical files.

Results:  A total of 1298 subjects was studied (600 upper gastrointestinal endoscopies and 698 lower gastrointestinal endoscopies). Patients referred for upper gastrointestinal endoscopy used most psychotropic agents (24%; odds ratio = 3.1; 95% confidence interval = 2.3–4.2), especially patients with an organic abnormality when compared with patients without an organic abnormality (42% versus 8%; odds ratio = 8.6; 95% confidence interval = 5.4–14.0). Patients with colonic polyps were more anxious (odds ratio = 1.7; 95% confidence interval = 1.0–2.9) and depressed (odds ratio = 1.8; 95% confidence interval = 1.1–3.1) than other patients referred for lower gastrointestinal endoscopy.

Conclusions:  There is no difference in anxiety nor depression between patients with and without organic abnormalities at endoscopy. Patients with colonic polyps are more anxious and depressed than other patients referred for lower gastrointestinal endoscopy. Psychotropic medication use is highest among patients with an organic abnormality in the proximal gastrointestinal tract.
Substantial genetic substructuring in southeastern and alpine Australia revealed by molecular phylogeography of the Egernia whitii (Lacertilia: Scincidae) species group
Authors: CHAPPLE DAVID G. , KEOGH J. SCOTT , HUTCHINSON MARK N.
Published: April 2005

Palaeoclimatic events and biogeographical processes since the mid‐Tertiary are believed to have strongly influenced the evolution and distribution of the terrestrial vertebrate fauna of southeastern Australia. We examined the phylogeography of the temperate‐adapted members of the Egernia whitii species group, a group of skinks that comprise both widespread low‐ to mid‐elevation (E. whitii) and montane‐restricted species (Egernia guthega, Egernia montana), in order to obtain important insights into the influence of past biogeographical processes on the herpetofauna of southeastern Australia. Sequence data were obtained from all six temperate‐adapted species within the E. whitii species group, and specifically from across the distributional ranges of E. whitii, E. guthega and E. montana. We targeted a fragment of the ND4 mitochondrial gene (696 bp) and analysed the data using maximum likelihood and Bayesian methods. Our data reveal a deep phylogeographical break in the east Gippsland region of Victoria between ‘northern’ (Queensland, New South Wales, Australian Capital Territory) and ‘southern’ (Victoria, Tasmania, South Australia) populations of E. whitii. This divergence appears to have occurred during the late Miocene–Pliocene, with the Gippsland basin possibly forming a geographical barrier to dispersal. Substantial structuring within both the ‘northern’ and the ‘southern’ clades is consistent with the effects of Plio–Pleistocene glacial‐interglacial cycles. Pleistocene glacial cycles also appear to have shaped the phylogeographical patterns observed in the alpine species, E. guthega and E. montana. We used our results to examine the biogeographical process that led to the origin and subsequent diversification of the lowland and alpine herpetofauna of southeastern Australia.
Regionally isolated populations of an imperiled Caribbean coral,Acropora palmata
Authors: BAUMS ILIANA B. , MILLER MARGARET W. , HELLBERG MICHAEL E.
Published: April 2005

The movements of larvae between marine populations are difficult to follow directly and have been the subject of much controversy, especially in the Caribbean. The debate centres on the degree to which populations are demographically open, such that depleted populations can be replenished by recruitment from distant healthy populations, or demographically closed and thus in need of local management. Given the depressed state of many tropical reef populations, the understanding of these movements now bears critically on the number, placement, and size of marine reserves. Most genetic analyses assume that dispersal patterns have been stable for thousands of generations, thus they commonly reflect past colonization histories more than ongoing dispersal. Recently developed multilocus genotyping approaches, however, have the demonstrated ability to detect both migration and population isolation over far shorter timescales. Previously, we developed five microsatellite markers and demonstrated them to be both Mendelian and coral‐specific. Using these markers and Bayesian analyses, we show here that populations of the imperiled reef‐building coral,Acropora palmata, have experienced little or no recent genetic exchange between the western and the eastern Caribbean. Puerto Rico is identified as an area of mixing between the two subregions. As a consequence of this regional isolation, populations in the western and eastern Caribbean should have the potential to adapt to local conditions and will require population‐specific management strategies.
Low level of gene flow from cultivated beets (Beta vulgaris L. ssp. vulgaris) into Danish populations of sea beet (Beta vulgaris L. ssp. maritima (L.) Arcangeli)
Authors: ANDERSEN N. S. , SIEGISMUND H. R. , MEYER V. , JØRGENSEN R. B.
Published: April 2005

Gene flow from sugar beets to sea beets occurs in the seed propagation areas in southern Europe. Some seed propagation also takes place in Denmark, but here the crop–wild gene flow has not been investigated. Hence, we studied gene flow to sea beet populations from sugar beet lines used in Danish seed propagation areas. A set of 12 Danish, two Swedish, one French, one Italian, one Dutch, and one Irish populations of sea beets, and four lines of sugar beet were analysed. To evaluate the genetic variation and gene flow, eight microsatellite loci were screened. This analysis revealed hybridization with cultivated beet in one of the sea beet populations from the centre of the Danish seed propagation area. Triploid hybrids found in this population were verified with flow cytometry. Possible hybrids or introgressed plants were also found in the French and Italian populations. However, individual assignment test using a Bayesian method provided 100% assignment success of diploid individuals into their correct subspecies of origin, and a Bayesian Markov chain Monte Carlo (MC MC) approach revealed clear distinction of individuals into groups according to their subspecies of origin, with a zero level of genetic admixture among subspecies. This underlines that introgression beyond the first hybridization is not extensive. The overall pattern of genetic distance and structure showed that Danish and Swedish sea beet populations were closely related to each other, and they are both more closely related to the population from Ireland than to the populations from France, the Netherlands, and Italy.
Phylogeographic structure and postglacial evolutionary history of water voles (Arvicola terrestris) in the United Kingdom
Authors: PIERTNEY STUART B. , STEWART WENDY A. , LAMBIN XAVIER , TELFER SANDRA , AARS JON , DALLAS JOHN F.
Published: April 2005

The phylogeographic pattern of mitochondrial DNA variation in water voles (Arvicola terrestris) from 57 localities across the United Kingdom and representative samples from Spain, France, Switzerland and Finland was determined from sequence variation in the central portion of the control region. Twenty‐seven different haplotypes were resolved which formed two distinct phylogenetic clades. This major division separated haplotypes found in Scotland from those found in England and Wales. Nested clade analysis of haplotypes indicated that such a division was a consequence of allopatric fragmentation. The haplotypes found in Switzerland, France and Spain clustered with Scottish haplotypes, whereas the haplotype from Finland clustered with the English/Welsh haplotypes. These patterns indicate that contemporary Scottish populations are derived from an Iberian glacial refugium, whereas English and Welsh populations are derived from an eastern European refugium. As such, the postglacial recolonization of the United Kingdom must have involved two colonization events, either in different localities with no subsequent contact, or as two waves separated over time, with the second wave of colonizers displacing the first. An analysis of molecular variance (amova) identified significant population genetic divergence within both the major clades, indicative of restricted gene flow and regional population isolation. The implications of both phylogeographical and population genetic structure are discussed in context with the conservation of water voles in Britain.
Social parasitism in fire ants (Solenopsis spp.): a potential mechanism for interspecies transfer of Wolbachia
Authors: DEDEINE FRANCK , AHRENS MICHAEL , CALCATERRA LUIS , SHOEMAKER D. DEWAYNE
Published: April 2005

One possible mechanism for interspecific transfer of Wolbachia is through the intimate contact between parasites and their hosts. We surveyed 10 species of fly parasitoids (Pseudacteon spp.) and one inquiline social parasite, Solenopsis daguerrei, for the presence and sequence identity (wsp gene) of Wolbachia. Two Wolbachia variants infecting S. daguerrei were identical to known variants infecting the two common ant host species, Solenopsis invicta and Solenopsis richteri, suggesting possible transfers of Wolbachia between this parasite and their hosts have occurred. Our data also revealed an unexpectedly high diversity of Wolbachia variants within S. daguerrei: up to eight variants were found within each individual, which, to our knowledge, is the highest reported number of Wolbachia variants infecting a single individual of any host species.
Nonequilibrium conditions following landscape rearrangement: the relative contribution of past and current hydrological landscapes on the genetic structure of a stream‐dwelling fish
Authors: POISSANT JOCELYN , KNIGHT THOMAS W. , FERGUSON MOIRA M.
Published: April 2005

Interpreting patterns of population structure in nature is often challenging, especially in dynamic landscapes where population genetic connectivity evolves over time. In this study, we document the absence of migration‐drift equilibrium in a stream‐dwelling euryhaline fish resulting from past fine‐scale drainage rearrangements and evaluate the relative contribution of past and current hydrological landscapes on observed population structure. Based on allelic variation at nine microsatellite loci, genetic relationships among 12 populations of brook charr, Salvelinus fontinalis, from Gros Morne National Park of Canada (GMNP, Newfoundland, Canada) did not reflect current stream hierarchical structure. In addition, we observed no correlation between population differentiation and contemporary landscape features (waterway distance and sums of altitudinal differences). Instead, population relationships were consistent with historical hydrological structure predicted a priori based on geomorphological and biogeographical evidences. Also, population differentiation was strongly correlated with inferred historical landscape features. Contemporary barriers have apparently preserved the signature of past genetic connectivity by constraining gene flow. Based on the relationships between population differentiation and current and past landscape features at various spatial scales, we suggest that brook charr genetic diversity in GMNP is mostly the result of small distance migrations at the time of colonization and subsequent differentiation through drift. This study highlights the potential of approaching landscapes from a combination of contemporary and historical perspectives when interpreting nonequilibrium population structures resulting from landscape rearrangement.
Chloroplast microsatellites: measures of genetic diversity and the effect of homoplasy
Authors: NAVASCUÉS M. , EMERSON B. C.
Published: April 2005

Chloroplast microsatellites have been widely used in population genetic studies of conifers in recent years. However, their haplotype configurations suggest that they could have high levels of homoplasy, thus limiting the power of these molecular markers. A coalescent‐based computer simulation was used to explore the influence of homoplasy on measures of genetic diversity based on chloroplast microsatellites. The conditions of the simulation were defined to fit isolated populations originating from the colonization of one single haplotype into an area left available after a glacial retreat. Simulated data were compared with empirical data available from the literature for a species ofPinusthat has expanded north after the Last Glacial Maximum. In the evaluation of genetic diversity, homoplasy was found to have little influence on Nei's unbiased haplotype diversity (HE) while Goldstein's genetic distance estimates () were much more affected. The effect of the number of chloroplast microsatellite loci for evaluation of genetic diversity is also discussed.
Unrelated queens coexist in colonies of the termite Macrotermes michaelseni
Authors: HACKER M. , KAIB M. , BAGINE R. K. N. , EPPLEN J. T. , BRANDL R.
Published: April 2005

Relatedness increases the likelihood of cooperation within colonies of social insects. Polygyny, the coexistence of numerous reproductive females (queens) in a colony, is common in mature colonies of the termite Macrotermes michaelseni. In this species, polygyny results from pleometrosis and from several female alates that jointly found a new colony. To explain this phenomenon, it was suggested that only related females cooperate and survive during maturation of colonies. Using multilocus fingerprints as well as microsatellites, we showed that nestmate queens in mature colonies are unrelated. Furthermore, we found that all nestmate queens contributed to the production of steriles. Even in mature colonies, several matrilines of steriles coexist within a colony. Although genetic diversity within colonies may increase the likelihood of conflicts, high genetic diversity may be important for foraging, colony growth, and resistance to disease and parasites.
Genetic structure and history of populations of the deep‐sea fish Helicolenus dactylopterus (Delaroche, 1809) inferred from mtDNA sequence analysis
Authors: ABOIM M. A. , MENEZES G. M. , SCHLITT T. , ROGERS A. D.
Published: April 2005

Helicolenus dactylopterus is an Atlantic benthopelagic fish species inhabiting high‐energy habitats on continental slopes, seamounts and islands. Partial sequences of the mitochondrial control region (D‐loop) and cytochrome b (cyt b) were used to test the hypothesis that H. dactylopterus disperses between continental margin, island and seamount habitats on intraregional, regional and oceanic scales in the North Atlantic. Individuals were collected from five different geographical areas: Azores, Madeira, Portugal (Peniche), Cape Verde and the northwest Atlantic. D‐loop (415 bp) and cyt b (423 bp) regions were partially sequenced for 208 and 212 individuals, respectively. Analysis of variation among mitochondrial DNA sequences based on pairwise F‐statistics and amova demonstrated marked genetic differentiation between populations in different geographical regions specifically the Mid‐Atlantic Ridge (Azores)/northeast Atlantic (Portugal, Madeira) compared to populations around the Cape Verde Islands and in the northwest Atlantic. Some evidence of intraregional genetic differentiation between populations was found. Minimum‐spanning network analysis revealed star‐shaped patterns suggesting that populations had undergone expansion following bottlenecks and/or they have been colonized by jump dispersal events across large geographical distances along pathways of major ocean currents. Mismatch distribution analysis indicated that Azores and northwest Atlantic populations fitted a model of historical population expansion following a bottleneck/founder event estimated to be between 0.64 and 1.2 million years ago (Ma).
Genetic spatial structure of European common hamsters (Cricetus cricetus) — a result of repeated range expansion and demographic bottlenecks
Authors: NEUMANN K. , MICHAUX J. R. , MAAK S. , JANSMAN H. A. H. , KAYSER A. , MUNDT G. , GATTERMANN R.
Published: April 2005

The spatial genetic structure of common hamsters (Cricetus cricetus) was investigated using three partial mitochondrial (mt) genes and 11 nuclear microsatellite loci. All marker systems revealed significant population differentiation across Europe. Hamsters in central and western Europe belong largely to two allopatric mitochondrial lineages south and northwest of the Carpathian and Sudetes. The southern group, ‘Pannonia’, comprises populations inside the Carpathian basin (Czech Republic, Hungary) while the second group, ‘North’, includes hamsters from Belgium, the Netherlands, France, and Germany. Isolation of the lineages is maintained by a combination of geographical and ecological barriers. Both main phylogeographical groups show signs of further subdivision. North is separated into highly polymorphic central German and less polymorphic western populations, which most likely split during late glacial expansion (15 000–10 000 bp). Clock estimates based on haplotype distributions predict a divergence of the two major lineages 85 000–147 000bp. Expansion times fall during the last glaciation (115 000–10 000 bp) corroborating fossil data, which identifyCricetus cricetusas characteristic of colder climatic phases. Despite the allopatry of mt haplotypes, there is an overlap of nuclear microsatellite alleles between phylogeographical units. Although there are strong evidence that Pannonian hamsters have persisted inside the Carpathian basin over the last 50 000 years, genetic differentiation among European hamsters has mainly been caused by immigration from different eastern refugia. Possible source populations are likely to be found in the Ukrainian and the southern Russian plains — core areas of hamster distribution. From there, hamsters have repeatedly expanded during the Quaternary.
Sexual selection for male dominance reduces opportunities for female mate choice in the European bitterling (Rhodeus sericeus)
Authors: REICHARD M. , BRYJA J. , ONDRAČKOVÁ M. , DÁVIDOVÁ M. , KANIEWSKA P. , SMITH C.
Published: April 2005

Sexual selection involves two main mechanisms: intrasexual competition for mates and intersexual mate choice. We experimentally separated intrasexual (male–male interference competition) and intersexual (female choice) components of sexual selection in a freshwater fish, the European bitterling (Rhodeus sericeus). We compared the roles of multiple morphological and behavioural traits in male success in both components of sexual competition, and their relation to male reproductive success, measured as paternity of offspring. Body size was important for both female choice and male–male competition, though females also preferred males that courted more vigorously. However, dominant males often monopolized females regardless of female preference. Subordinate males were not excluded from reproduction and sired some offspring, possibly through sneaked ejaculations. Male dominance and a greater intensity of carotenoid‐based red colouration in their iris were the best predictors of male reproductive success. The extent of red iris colouration and parasite load did not have significant effects on female choice, male dominance or male reproductive success. No effect of parasite load on the expression of red eye colouration was detected, though this may have been due to low parasite prevalence in males overall. In conclusion, we showed that even though larger body size was favoured in both intersexual and intrasexual selection, male–male interference competition reduced opportunities for female choice. Females, despite being choosy, had limited control over the paternity of their offspring. Our study highlights the need for reliable measures of male reproductive success in studies of sexual selection.
Mucosal cytokine and antigen‐specific responses to Cryptosporidium parvum in IL‐12p40 KO mice
Authors: Ehigiator H. N. , Romagnoli P. , Borgelt K. , Fernandez M. , McNair N. , Secor W. E. , Mead J. R.
Published: April 2005

Studies of cellular immune responses to Cryptosporidium parvum have been limited in part by lack of suitable animal models. IL‐12p40–/–mice are susceptible to initial infection with C. parvum but recover within 2 weeks, rendering the animals resistant to reinfection. Because the host responses that determine duration and severity of primary infection are not yet understood, we studied the cellular immune response to primary infection with C. parvum in IL‐12p40–/–mice and also explored possible mechanisms for this response. Female IL‐12p40–/–mice were inoculated with 10 000 oocysts. Uninfected age‐matched mice served as controls. At different time intervals following exposure to oocysts, mice were sacrificed and their intestine, spleen, and mesenteric lymph node tissues were harvested. Cellular immune responses to C. parvum were characterized. Infection of IL‐12p40–/–mice induced changes in the gene expression of the cytokines IFN‐γ, IL‐4, IL‐15, IL‐18, TNF‐α and TGF‐β during primary infection. There was also a significant increase in total numbers of lymphocytes and CD19/CD62L‐expressing cells in mesenteric lymph nodes. These MLN cells exhibited increased antigen‐specific proliferation and cytokine production (IL‐6 and IFN‐γ) levels when stimulated in vitro. These observations delineate the cellular immune responses during acute C. parvum infection of the IL‐12p40–/–mouse model.
Oral immunization with a live recombinant attenuated Salmonella typhimurium protects mice against Toxoplasma gondii
Authors: Cong H. , Gu Q. M. , Jiang Y. , He S. Y. , Zhou H. Y. , Yang T. T. , Li Y. , Zhao Q. L.
Published: April 2005

The natural site of infection for T. gondii is the mucosal surface of the intestine, so the protective immunity obtained after natural infection with T. gondii points to the importance of developing a vaccine that stimulates mucosal defences. In this study, an aroA− and aroD− attenuated strain of Salmonella typhimurium (BRD509) has been used to deliver the recombinant eukaryotic plasmid pSAG1‐2/CTA2/B expressing a multi‐antigenic gene encoding SAG1 and SAG2 of T. gondii linked to A2/B subunits of cholera toxin as a candidate oral T. gondii vaccine. Immunoblot analysis showed compound gene expression in HeLa cells in vitro and intragastric immunization of mice with the recombinant salmonella resulted in the induction of humoral and Th1 type cellular immune responses and afforded protection against RH strain T. gondii challenge. Anti‐T. gondii IgG values increased markedly in the BRD509/pSAG1‐2‐CTA2/B immunized group; these values were significantly higher than those in the negative controls (P = 0·008). With CTA2/B genetic adjuvant, the T. gondii‐specific response was predominantly Th1, indicating that the CTA2/B genetic adjuvant was able to overcome the strong Th2‐bias of the antigen (IgG2a >> IgG1). Antigen‐specific T cell proliferative responses and CTL activity were significantly enhanced when cholera toxin CTA2/B genetic adjuvant was used (P = 0·009; P = 0·006). Culture supernatants from antigen‐stimulated splenocytes from mice in these groups were also examined by ELISA for Th1‐ and Th2‐type cytokines; mean IFN‐γ levels produced after oral immunization with BRD509/pSAG1‐2‐CTA2/B were about nine‐fold higher than after immunization with BRD509/pSAG1‐2 (P = 0·007). On the other hand, the levels of IL‐4 were low for all groups and no increase was seen in the presence of CTA2/B genetic adjuvant. When the immunized mice were intraperitoneally challenged with 103 tachyzoites of the highly virulent RH strain, the survival time of the mice immunized with BRD509/pSAG1‐2‐CTA2/B was markedly longer than other groups (P = 0·003) and a 40% survival rate was achieved. This is the first report that demonstrates that an oral attenuated salmonella DNA vaccine can induce protective immunity against the acute phase of T. gondii infection.
Cytokine mRNA expressions in symptomatic vs. asymptomatic amoebiasis patients
Authors: Bansal D. , Sehgal R. , Chawla Y. , Malla N. , Mahajan R. C.
Published: April 2005

Infection with Entamoeba histolytica results in high mortality worldwide. Studies on the cytokine response in symptomatic and asymptomatic amoebiasis (caused by E. histolytica, the pathogenic species and E. dispar, the non‐pathogenic species) subjects and their correlation with symptomatology are lacking. The present study reports the cytokine response (TNF‐α, IFN‐γ, IL‐4, IL‐10 and TGF‐β) in such subjects as measured by RT‐PCR. The results showed significantly (< 0·05) higher expressions of IL‐10 and TGF‐β in the symptomatic group as compared to the asymptomatic and healthy controls. The cytokine profile indicated the role of suppressive immune response in symptomatic amoebiasis patients.
The pathogenicity of Entamoeba histolytica is related to the capacity of evading innate immunity
Authors: Campos‐Rodríguezp Rafael , Jarillo‐Luna Adriana
Published: April 2005

The host and parasite factors that influence susceptibility to Entamoeba histolytica infection and disease are not well understood. Entamoeba histolytica pathogenicity has been considered by focusing principally on parasite rather than host factors. Thus, research has concentrated on explaining the molecular differences between pathogenic E. histolytica and non‐pathogenic E. dispar. However, the amoeba molecules considered most important for host tissue destruction (amoebapore, galactose/N‐acetyl galactosamine inhibitable lectin, and cysteine proteinases) are present in both pathogenic E. histolytica and non‐pathogenic E. dispar. In addition, the genetic differences in pathogenicity among E. histolytica isolates are unlikely to completely explain the different outcomes of infection. Considering that the principal difference between pathogenic and non‐pathogenic amoebas lies in their surface coats, we propose that pathogenicity of the amoebas is related to the composition and properties of the surface coat components (or pathogen‐associated molecular patterns, PAMPs), and the ability of innate immune response to recognize these components and eliminate the parasite. According to this hypothesis, a key feature that may distinguish pathogenic (E. histolytica) from non‐pathogenic (E. dispar) strains is whether or not they can overcome innate immune defences. A corollary of this hypothesis is that in susceptible individuals the PAMPs are either not recognized or they are recognized by a set of Toll‐like receptors (TLRs) that leads to an inflammatory response. In both cases, the result is tissue damage. On the contrary, in resistant individuals the innate/inflammatory response, induced through the activation of a different set of TLRs, eliminates the parasite.
Presence of the LDNF glycan on the host‐protective H‐gal‐GP fraction from Haemonchus contortus
Authors: Geldhof P. , Newlands G. F. J. , Nyame K. , Cummings R. , Smith W. D. , Knox D. P.
Published: April 2005

Immunization of sheep with the gut membrane‐associated protein complex H‐gal‐GP of adult Haemonchus contortus induces high levels of protection against a homologous challenge infection. Protection is correlated with a systemic IgG response against the antigen. Analysis of the antibody response showed that the majority of the antigen‐specific IgG was of the IgG2 isotype. A substantial proportion (74%) of this response was directed against the glycan component of H‐gal‐GP. The high immunogenicity of the H‐gal‐GP glycans may be due to the presence of the fucosylated LacdiNAc (LDNF) antigen. 2D electrophoresis, Western blotting and mass spectrometry analysis of H‐gal‐GP showed that this glycan epitope was specifically located on a metalloendopeptidase, MEP3. MEP3 is the most abundant protein in H‐gal‐GP and has been identified as one of the most likely protective components of the complex. Here, we present evidence that the LDNF glycan does not contribute to the protective capacity of H‐gal‐GP. Animals vaccinated with reduced and denatured H‐gal‐GP are not protected against subsequent infection, although the antibody response against the LDNF glycan is very similar to that of animals vaccinated with the native H‐gal‐GP. In addition, an alternative version of H‐gal‐GP, H‐sialgal‐GP, which is equally protective, but isolated by affinity chromatography on jacalin lectin rather than peanut lectin, contains a MEP3 component which has no detectable LDNF glycan.
Developmental Expression of Echinonectin, an Endogenous Lectin of the Sea Urchin Embryo
Authors: Fuhrman Margaret H. , Suhan Joseph P. , Ettensohn Charles A.
Published: April 2005

Echinonectin (EN) is a galactose‐binding lectin present in eggs and embryos of the sea urchin Lytechinus variegatus. Recent studies have suggested that EN is a hyaline layer protein that may function as a substrate adhesion molecule (SAM) during development. We have used monoclonal and affinity‐purified polyclonal antibodies that specifically recognize this protein to determine its spatial and temporal expression during embryogenesis. EN is stored in granules or vesicles in the unfertilized egg. After fertilization, these granules are rapidly redistributed to the apical cytoplasm of the zygote. Our results show that at subsequent stages of development the lectin is expressed by cells of all three germ layers, including cells of the developing gut, coelomic pouches, and ectoderm, and by both primary and secondary mesenchyme cells. In contrast to previous observations based solely upon light level immunofluorescent staining, immunoelectron microscopy demonstrates that EN is localized in intracellular, membrane‐bounded vesicles. In epithelial cell types these vesicles have a highly polarized distribution and are found in the apical cortical cytoplasm. In mesenchyme cells the distribution of EN‐containing vesicles is not obviously polarized. Steady‐state levels of EN protein in the embryo remain almost constant from fertilization to the pluteus larva stage, Metabolic labeling studies show that synthesis of EN in L. variegatus begins immediately after fertilization and continues throughout embryogenesis. Monospecific antibodies raised against L. variegatus EN have also been used to determine whether this lectin is expressed in other echinoid species.
Purification and Characterization of Sperm Creatine Kinase and Guanylate Cyclase of the Sea Urchin Hemicentrotus pulcherrimus
Authors: Harumi Tatsuo , Kurita Masanori , Suzuki Norio
Published: April 2005

Creatine kinase and guanylate cyclase were purified from Hemicentrotus pulcherrimus spermatozoa. The molecular weight of the purified sperm tail creatine kinase was estimated to be 137,000 by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS‐PAGE). Sperm tail guanylate cyclase was purified by chromatography on a WGA‐Sepharose column connected to a Concanavalin A‐Sepharose column, and a Superose 12 HR column. The molecular weight of the tail guanylate cyclase was estimated to be 128,000 by SDS‐PAGE. The specific activity of the purified enzyme was 8.25 μmol of cGMP formed/min/mg protein. Sperm‐activating peptide I (SAP‐I) causes an electrophoretic mobility shift of H. pulcherrimus sperm guanylate cyclase from 131 kDa to 128 kDa. The 131 kDa form of guanylate cyclase was co‐purified with a 76 kDa protein, whose molecular mass is similar to that of a SAP‐I receptor. The purified 131 kDa form of guanylate cyclase had higher activity than the 128 kDa form. The 131 kDa and 128 kDa forms of guanylate cyclase contained 23.83 ± 0.65 and 4.16 ± 0.45 moles of phosphate per mol protein (mean ± S.D.; n = 3), respectively. The activities of guanylate cyclase and creatine kinase increased during the testis development. During spermatogenesis, sperm tail creatine kinase was detected immunohistochemically only in mature spermatozoa.