bluuebunny/crossref_metadata_2025_split huggingface dataset:
Capsule endoscopy: current indications and future prospects
Authors: Remedios M. L. , Appleyard M. 
Published: April 2005

Abstract Capsule endoscopy represents a significant advance in the investigation of small bowel diseases and the beginning of wireless endoscopic imaging. Capsule endoscopy involves swallowing a video capsule endoscope, which is painless and relatively safe. Its use has been established for suspected small bowel bleeding, and the role of capsule endoscopy in the investigation of inflammatory bowel disease, iatrogenic disease, polyposis syndromes and coeliac disease is evolving. It is likely that in many instances it will become the next test after standard endoscopic evaluation. Early data suggest that capsule endoscopy improves outcome in patients with suspected small bowel bleeding, but more data are required on outcomes for the other indications. (Intern Med J 2005; 35: 234–239)
Biomineralization of endolithic microbes in rocks from the McMurdo Dry Valleys of Antarctica: implications for microbial fossil formation and their detection
Authors: Wierzchos Jacek , Sancho Leopoldo García , Ascaso Carmen 
Published: April 2005

SummaryIn some zones of Antarctica's cold and dry desert, the extinction of cryptoendolithic microorganisms leaves behind inorganic traces of microbial life. In this paper, we examine the transition from live microorganisms, through their decay, to microbial fossils using in situ microscopy (transmission electron microscopy, scanning electron microscopy in back‐scattered electron mode) and microanalytical (energy dispersive X‐ray spectroscopy) techniques. Our results demonstrate that, after their death, endolithic microorganisms inhabiting Commonwealth Glacier sandstone from the Antarctica McMurdo Dry Valleys become mineralized. In some cases, epicellular deposition of minerals and/or simply filling up of empty moulds by minerals leads to the formation of cell‐shaped structures that may be considered biomarkers. The continuous deposition of allochthonous clay minerals and sulfate‐rich salts fills the sandstone pores. This process can give rise to microbial fossils with distinguishable cell wall structures. Often, fossilized cell interiors were of a different chemical composition to the mineralized cell walls. We propose that the microbial fossil formation observed was induced by mineral precipitation resulting from inorganic processes occurring after the death of cryptoendolithic microorganisms. Nevertheless, it must have been the organic template that provoked the diffusion of mineral elements and gave rise to their characteristic distribution pattern inside the fossilized cells.
Viruses, prokaryotes and DNA in the sediments of a deep‐hypersaline anoxic basin (DHAB) of the Mediterranean Sea
Authors: Danovaro R. , Corinaldesi C. , Dell’Anno A. , Fabiano M. , Corselli C. 
Published: April 2005

SummaryViral and prokaryote abundance were investigated in a deep‐hypersaline anoxic basin of the Eastern Mediterranean Sea (DHAB Atalante basin at c. 3000 m depth). This system was compared with two nearby deep‐sea sites characterized by oxic conditions. Viral abundance and virus to prokaryote abundance ratio in hypersaline anoxic sediments displayed values close to those reported in oxic sites. The analysis of vertical profiles of viral abundance in the Atalante basin revealed the lack of significant changes with depth in the sediment, suggesting that benthic viruses in these anoxic and hypersaline conditions are preserved or resistant to decay. The anoxic basin displayed also very high concentrations of labile organic components (proteins and lipids) and extracellular DNA. These findings suggest that the DHAB sediments represent a reservoir for long‐term preservation of benthic viruses and nucleic acids.
The range of protists in Mono Lake, a hypersaline soda lake in the eastern sierras
Authors: DAVIDSON LLOYD A. , DAVIDSON ARDEN E. 
Published: April 2005

In spite of the controversies surrounding the environmental deterioration of Mono Lake, and the significant amount of research being done on this remarkably productive body of water, nobody has ever attempted to survey the protists that live beneath its surface. Beginning in July of 2003, we have been trying to remedy this situation and we spent 2 months there studying the protistan species that reside in its waters and since then have been receiving regular sample collections for analysis. Based on the metazoan eukaryotes that live in this lake, which include only Artemia monica, Ephydra hians, rare rotifers and a nematode, we were warned to expect the lake to be depauperate of protists as well. However, we are happy to report that, while not as rich in species as most freshwater lakes, Mono Lake does support a robust population of phagotrophic and heterotrophic protozoa in addition to its many species of unicellular algae, including diatoms. It contains ciliate species representing at least the genera Cyclidium, Frontonia, Lacrymaria, Litonotus, Euplotes and Aspidisca, and the stalked suctorian Tokophrya. Additionally, there are species representing the heliozoa, helioflagellates, choanoflagellates, Pseudobodo, Cercomonas and Chilomastix, among other flagellates. The gymnamoebae are represented by Vanella, Nuclearia, Mayorella and Hartmanella, and, from the Heterolobosea, probable Vahlkampfia and Gruberella species. Micrographs of many of these species will be presented. Work on these species is still very much in its preliminary stages and a more detailed analysis and identification of the protists found in this extreme environment is advancing.This work was partially supported by an NSF grant (MCB 99‐77901) to Robert Jellison.
The shell or the kernel: biodiversity estimates of benthic foraminifera
Authors: HABURA ANDREA , HANES STEVEN D. , ALEXANDER STEPHEN P. , BOWSER SAMUEL S. 
Published: April 2005

Estimates of protist biodiversity and distribution have until recently relied on the morphological identification of individual cells. The advent of environmental‐DNA‐based surveys of these protist communities has broadened our understanding of species richness and diversity. A “total‐evidence biodiversity” approach gives two benefits. First, it allows “back‐comparison” to previous studies of ecosystems, permitting estimates of the amount of cryptic diversity in different sampling regimes (and by extension, the fossil record). Second, it will provide the best possible estimate of the total species richness of current study sites. Here, we use a well‐studied benthic protist community, the foraminiferal assemblage of McMurdo Sound, Antarctica, to determine the effective parameters of both detection methods. We find that molecular‐based techniques detect well‐characterized calcareous species at depths too great to allow calcification, suggesting that these forms may be able to survive without their distinctive tests. “Fragile” taxa also appear to be better represented in molecular surveys than in morphological ones. The strengths of a combined morphological–molecular approach are demonstrated by an assessment of the distribution of two species in the genus Notodendrodes; morphological detection excels in the identification of distinctive, patchily distributed adults, whereas molecular detection with taxon‐specific probes enabled identification in less favorable sampling conditions. Such a “broad‐plus‐deep” approach appears to maximize detection efficiency in this Antarctic setting.Work supported by NSF OPP0003639.
Effect of the micronucleus on cellular structures in several hypotrichous ciliates
Authors: JIN LIPEI , LIU XINYING , MAO YONGZHEN 
Published: April 2005

It is commonly believed that there is a sharp functional demarcation between the two types of nuclei of ciliated protozoa: the micronucleus for reorganization of the nuclear apparatus during sexual reproduction and the macronucleus for controlling somatic functions. This traditional view, however, has been critically re‐examined recently and correlative researches have shown that the micronucleus plays an essential role in the development of some ciliates. Here we report some morphological evidences about the effect of the micronucleus on cellular structures from amicronucleate cell lines of five hypotrichous ciliates (Pseudourostyla cristata, Pseudokeronopsis monilata, Paraurostyla weissei, Uroleptus piscis and Oxytricha faurei). All amicronucleate cell lines were generated by amputation and investigated by protargol staining. These observations manifest that micronucleus is indispensable to vigor and viability for P. weissei, to maintaining the integrity of adoral zone of membranelles (AZM) and/or undulating membranes (UM) for P. cristata, P. monilata and U. piscis, and to keeping regularity of cell shape as well as of the number and the structure of the macronuclei for O. faurei. These results suggest that the manifestations of the somatic function of micronucleus for different ciliates are varied and the close species might have a similar form of expression.This work was supported by a grant from NSFC (No: 30370210) to L. P. JIN.
Protozoa and pathogenic bacteria: lessons learned from Legionella pneumophila
Authors: SMITH A. W. 
Published: April 2005

The microhabitats favoured by protozoa are dynamic ecosystems comprising a heterogeneous microflora of bacteria and fungi as well as protozoa in a complex biofilm. Many protozoa feed by grazing on microbial biofilms, but they do not do so indiscriminately. A dynamic equilibrium will exist and the nature of the relationship changes depending on environmental conditions. The view of protozoa as the hunter and bacteria as the hunted is now recognised as overly simplistic. Some bacteria not only resist predation by protozoa, but also have become endosymbionts of free‐living protozoa, demonstrating adaptation to the otherwise hostile intracellular environment. The concept that protozoa can be reservoirs for some pathogens is more widely appreciated and the catalyst for much of this work came from the observation that Legionella pneumophila infects and multiplies within some species of free‐living amoebae. In addition to amplifying cell numbers, the phenotype of intra‐protozoal‐grown cells is quite distinct from their free‐living counterparts cultured on complex laboratory media: altered surface properties, decreased susceptibility to chemical inactivation and antibiotics, and enhanced invasiveness for mammalian cells. There is significant conservation in the genes used by L. pneumophila to parasitize protozoa and macrophages and it has been proposed that co‐evolution of bacteria and lower order eukaryotic cells has equipped bacteria both for environmental survival and virulence towards higher order eukaryotes. Other authors have even described protozoa as an “evolutionary gym” enabling L. pneumophila to “train” for its role in invading higher eukaryotic organisms.A growing list of bacteria and fungi that interact with protozoa confirm that the co‐evolution between L. pneumophila and protozoa is not unique in nature. An emerging theme amongst many of the micro‐organisms associating with protozoa is that they typically are recognised as opportunistic pathogens and many lack a recognised animal host. These features are suggestive of a relationship much closer to symbiosis which becomes parasitic only in special circumstances. The question remains why this is so? The answer could lie in co‐evolution with lower order eukaryotic organisms present in biofilms.
Multigenic Family Analysis among the Encephalitozoon Genus
Authors: DIA N. , TOGUEBAYE B. S. , VIVARES C. P. , CORNILLOT E. 
Published: April 2005

Encephalitozoon cuniculi is a parasite presenting a wide range of hosts among mammals (including human). Bioinformatic analysis of the genome sequence (11 chromosomes for a haploid genome size of 2.9 Mbp) revealed the presence of multigenic families in a subterminal position on the chromosomes (in 5′ of the rDNA copies on 22 extremities). One of these families was called InterB and clustered together about 30 genes within 10 homology groups. According to the predictions, the typical InterB protein presents in its N‐terminal part a signal peptide, followed by two transmembrane domains. The core of this protein is characterized by an α hypervariable region rich in glutamine and lysine. The C‐terminal region presents several conserved motifs (GGAR, YHL and FQI).A set of specific and generic oligonucleotides was designed to study the InterB genomic repertoire. The migration profile of the generic primers PCR products presents five to six bands. This profile is well conserved for the E. cuniculi isolates as well as for the different Encephalitozoon species. Some polymorphism is evident with amplicons of 300 bp in average. Sequence analysis revealed a higher level of polymorphism, especially in the α region. The InterB repertoire of transcripts was studied by reverse transcription. All InterB genes should be transcribed. There is no known homologue for InterB but, considering the position of the genes, we speculate on the possible role of InterB proteins. Similar multigenic family organizations have been described for proteins involved in pathogenicity of parasites such as Trypanosoma, Plasmodium, Giardia or Pneumocysti.
Microsporidia of Fishes: Characterization of a New Species and Development of the Infectious Focus
Authors: MANSOUR L. , PRENSIER G. , BEN HASSINE O. K. , VIVARES C. P. , CORNILLOT E. 
Published: April 2005

Fish parasites microsporidia are distributed among fifteen genera. In most cases, the infectious focus present a cyst‐like structure. According to the stage of evolution, the infection focus is either a xenoma or a granuloma. Specific host‐parasite interaction is at the origin of a large diversity of foci form and tissue specificity.In this context, we describe Microgemma tincae n. sp. in the peacock wrasse, Symphodus tinca, fished near the Tunisian coasts. M. tincae is found in the liver of its host. Parasite characterization is based on the ultrastructural description of the life cycle (Transmission Electronic Microscopy) as well as on a part of the rDNA sequence (840 bp of the ssu gene). The inflammatory reaction responsible for the transition from xenoma to granuloma is carefully described. Prevalence is high and small fishes present high level of infection (several foci). One of the parameters responsible for the distribution of the number of foci per fish is the ratio between secondary and new infection.We studied the Spraguea lophii infection to address this question at the molecular level in the angler fish, Lophius spp. We wanted to know if the reaction set up by the host was sufficient to stop the parasite propagation. The analysis was made in two‐dimensional (2D) PFGE at an infection focus scale (1‐mm3 samples). We compared 2D genome images from samples isolated from different parts of one or several infection foci of the same or different fish origin. We conclude that the fish immune system cannot avoid secondary infection.
Intestinal microsporidiosis among HIV‐positive patients in Libreville (Gabon): Enterocytozoon bieneusi isolates show a very high diversity of genotypes
Authors: BRETON J. , KOMBILA M. , OKOME‐NKOUMOU M. , RINDER H. , THELLIER M. 
Published: April 2005

Intestinal microsporidiosis caused by Enterocytozoon bieneusi and Encephalitozoon intestinalis are opportunistic infections occurring in severely immuno‐depressed patients, and may cause severe chronic diarrhea. Due to the extent of the HIV pandemic, microsporidia could pose a serious threat to public health in Africa. This study was conducted in Libreville, Gabon, central Africa, among HIV‐positive patients between September 2002 and December 2003. Criteria for inclusion were being HIV positive (HIV1 and/or HIV2), regardless of the CD4 cell count, stage of the disease or gastrointestinal symptoms. Nine hundred and ninety‐tree stool samples from 836 patients (mean age 38 years, range 18 months‐74 years) were screened for microsporidia by immunofluorescence using species‐specific monoclonal antibodies and confirmed by PCR. Twenty seven cases of E. bieneusi infection were found in the cohort, a prevalence of 2.7%. These patients were in the most severely immuno‐depressed group, 84% had a CD4 cell count below 200/mm3 compared to 57% of the cohort (mean=55 CD4+cells/mm3 compared to a mean of 88/mm3 for the microsporidia negative patients with less than 200 CD4/mm3).The ribosomal DNA ITS sequence has been determined for several E. bieneusi isolates. A very high diversity of genotypes wasfound: eight different sequences were found from only 12 samples. This is surprisingly high since in previous studies conducted in Europe and America only 15 of the 49 E. bieneusi genotypes described have been found to infect humans. Only three genotypes from our samples have already been described: type K (two specimens). previously reported in human and cat, type D (one specimen) in human, pig and rhesus monkey, type E (1 specimen) in man, pig, racoon and muskrat. The five other genotypes are new and have been named Gabon‐1 to 5. The phylogenetic analysis of the sequences shows that genotypes Gabon‐1,2,3 and 4 (one specimen each) are close to types E, WL12, D and K, respectively, which belong to a group comprising most genotypes described so far. However, the Gabon‐5 genotype (four specimens) is only distantly related to this group and is most apparent to the group of genotypes (WL1‐3) recently described from racoons in North America. It was thus suggested that this group could represent another species or subspecies of E. bieneusi which are host‐adapted and do not infect humans. However, the finding of genotype Gabon‐5 shows that even distantly related genotypes infect severely immuno‐depressed humans.This work was supported by the French National Agency for AIDS Research (ANRS‐1264).
Paramyxea in Scandinavia
Authors: LARSSON J. I. R. , KØIE M. 
Published: April 2005

Paramyxea is a small phylum of marine parasites, using molluscs, crustaceans or polychaetes as hosts. Probably the group is cosmopolitan, but the distribution known so fais restricted to southern Europe, Australia and East Asia. Polychaetes of the genus Nephtys, collected from Danish waters, are infested with a paramyxean parasite in the gut epithelium. The parasite develops intracellularly and is in close contact with the cytoplasm of the host cell. When harbouring mature spores gut cells are lysed and spores are released into the digestive tract.Reproduction is by endogeneous budding, typical for Paramyxea, and the only reproduction observed is sporogony. A stem cell (cell 1) yields two or four sporonts (cell 2), each of which produces four tetracellular spores (cells 3–6). The mature spore is fusiform, about 10 microns long, and surrounded by an individual sac filled with fibrous material. The sacs are united to a spherial body with prominent striated terminal projections. Haplosporosomes, of three different types, are present in cells 1, 4 and 5. The species, which is new to science, is the first find of Paramyxea from Scandinavia.
Protozoan population and fermentation parameters of rumen contents of sheep from heavy metal contaminated area
Authors: VÁRADYOVÁ Z. , MIHALIKOVÁ K. , JAVORSKY P. , KISIDAYOVÁ S. 
Published: April 2005

The rumen contents from Slovak Merino sheep (12 months of age) were used for in vitro study on the influence of area contaminated by heavy metals on rumen fermentation and protozoan activity. Sheep were browsing in the contaminated area of Kal'ava village (Slovakia) and were exposed to 1‐year intake of heavy metals. The area of Kal'ava is contaminated by atmospheric pollution from the non‐ferrous metal works at Krompachy (Slovakia). Based on the levels of mercury (4.8 mg'kg), copper (232.9 mg/kg), cadmium (1.2 mg/kg), lead (92.5 mg/kg) and arsenic (74.6 mg/1) the soil was categorized as profusely contaminated. Grass contamination was below the toxic limits. In the tested materials, copper was present at the highest levels followed by lead and arsenic. Meadow hay was used as a tested substrate of fermentation activity; it was incubated with buffered rumen fluid for 24 h. The significantly decreased values of fermentation parameters (total gas, methane, total VFA, acetate) were associated with a reduced total concentration of protozoans. Significant decrease was detected in the total rumen ciliate population and population of c. No significant differences were observed in the concentration of Dasytricha ruminantium and Ophryoscolex c. tricoronatus.The study was supported by funds from Grant Agency for Science of the Slovak Academy of Sciences (2/3058/23, 2/3064/23) and funds from APVT grant (51012602).
A non‐staining chlorhexidine mouthwash? Probably not: a study in vitro
Authors: Addy M , Sharif N , Moran J 
Published: April 2005

AbstractBackground and aim:  Tooth staining is a common side effect of chlorhexidine mouth rinses and caused by the interaction of the di‐cationic antiseptic with dietary chromogens. A product is now available, which claims an anti‐discolouration system (ADS) with one clinical study in support. This study in vitro aims to determine whether two ADS rinses do or do not bind dietary chromogens.Method and materials:  Optically clear acrylic specimens were cycled through human saliva (2 min), one of the three chlorhexidine rinses (two ADS and a positive control) (2 min) or water and then soaked in tea (60 min). After each cycle the optical density (OD) of specimens were read on a UV/visible spectrophotometer. The exit point was the cycle at which OD was >2.0.Results:  All three rinses exceeded OD 2 at 11 cycles and there was no significant difference in staining for the ADS rinses compared with the positive control rinse.Conclusion:  Based on extensive literature for the correlation of this test in vitro with chlorhexidine anti‐plaque activity and propensity to stain in vivo these ADS rinses will have the same anti‐plaque efficacy and potential to cause stain as established chlorhexidine rinse products.
Dental anxiety in children and its relationship to dental caries and gingival condition
Authors: Taani DQ , El‐Qaderi SS , Abu Alhaija ESJ 
Published: April 2005

Abstract:The aim of this study was to determine the levels of dental anxiety, dental caries and gingivitis among 12–15‐year‐old schoolchildren, in Irbid Governorate/northern Jordan, and to evaluate the correlation between these variables. Two schools were selected by a simple random method from each of the five geographic areas in Irbid Governorate. All children (1021), from the 10 selected schools, who participated in this study completed a questionnaire modified from Kleinknecht's Dental Fear Survey (DFS questionnaire). Children underwent oral examination for dental caries and gingival condition, using Decayed, Missing and Filled Teeth (DMFT) Index and Löe and Silness Gingival Index (GI), respectively. Results of this survey showed that the prevalence of low to moderate ‘general dental fear’ among the study population was 43% while that of ‘high dental fear’ was 10%. The self‐reported ‘general fear of dental treatment’ was higher among girls than boys. Fear of specific stimuli (pain) was the most common source of dental fear. The sight and sensation of the anaesthetic needle and the sight, sound and sensation of the drill were rated the most fear‐eliciting stimuli. The mean DMFT (2.89) and GI (1.80) of boys was not significantly different from the DMFT (3.37) and GI (1.53) of girls (P > 0.05). Spearman's correlation test demonstrated no association between ‘general dental fear’ and dental caries (r = 0.06) or gingivitis (r = 0.007).