bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cynical hostility as a determinant of toothbrushing frequency and oral hygiene
Authors: Mettovaara Hanna‐Leena , Suominen‐Taipale Anna‐Liisa , Uutela Antti K. , Martelin Tuija P. , Knuuttila Matti L.E. 
Published: December 2005

AbstractAim:Our aim was to investigate whether cynical hostility, self‐reported toothbrushing frequency and objectively assessed levels of oral hygiene were associated.Material and Methods: The present study sample consisted of 4156 30–64‐year‐old dentate Finns. The questionnaire and the home interview included information about socioeconomic and sociodemographic factors and behavioural variables, such as toothbrushing frequency, dental attendance, smoking and cynical hostility. The level of oral hygiene was assessed during a clinical oral examination. The χ2 test and ordinal logistic regression analyses were used.Results: After controlling for sociodemographic and socioeconomic factors, smoking habits and reported dental attendance, the subjects belonging to the lowest cynical hostility level were found to brush their teeth significantly more often and to have better oral hygiene compared with those belonging the highest cynical hostility level. Toothbrushing frequency was adjusted when oral hygiene was used as the outcome variable. The association of cynical hostility with toothbrushing frequency and the oral hygiene seems to be partly dependent on the level of education.Conclusions: Cynical hostility is a psychosocial risk marker for the frequency and quality of toothbrushing and it could be a connecting trait between general health behaviour and oral health behaviour.
Autogenous bone graft in conjunction with enamel matrix derivative in the treatment of deep periodontal intra‐osseous defects: a report of 13 consecutively treated patients
Authors: Trombelli Leonardo , Annunziata Marco , Belardo Salvatore , Farina Roberto , Scabbia Alessandro , Guida Luigi 
Published: December 2005

AbstractAim: The purpose of the present study was to investigate the effectiveness of a regenerative procedure based on supra‐crestal soft tissue preservation in association with combined autogenous bone (AB) graft/enamel matrix derivative (EMD) application in the treatment of deep periodontal intra‐osseous defects.Methods: Thirteen consecutively treated patients, seven females and six males, aged 30–65 years, three smokers, were included. A total of 15 deep, one‐ to two‐wall intra‐osseous defects were selected. Immediately before surgery and 6 months after surgery, pocket probing depth (PPD), clinical attachment level (CAL), and gingival recession (REC) were recorded.Results: PPD amounted to 9.4±1.8 mm before surgery, and decreased to 4.7±1.2 mm post‐surgery (p<0.0000). CAL varied from 10.5±2.0 mm pre‐surgery to 6.2±1.7 mm post‐surgery (p<0.0000), with CAL gain averaging 4.3±1.4 mm. Fourteen (93.3%) defects presented CAL gain 3 mm. REC change was 0.4±0.7 mm.Conclusions: Results from the present study indicated that a regenerative procedure based on supra‐crestal soft tissue preservation and combined AB/EMD treatment leads to a clinically and statistically significant improvement of soft tissue conditions of deep periodontal intra‐osseous defects.
Imaging the Neonatal Brain: Novel Techniques
Authors: Whitby E. H. , Griffiths P. D. , Paley M. N. 
Published: December 2005

SummaryMagnetic resonance (MR) imaging of the neonate can be a difficult procedure especially when most imaging departments are geographically distant to neonatal intensive care units. These vulnerable neonates are often notable to be imaged by MR as they are too sick to transport. MR scanners are expensive pieces of equipment in specialist centres and this limits their availability. Low field strength scanners have a small capital cost and small running costs. This has allowed them to be developed for dedicated neonatal imaging in a few centres. Experience using these scanners is limited but they provide additional information over and above ultrasound imaging and are an ideal method to increase the availability of MR. MR compatible incubators that double as transport incubators reduce the amount of handling the vulnerable neonate is exposed to and maintains the environmental conditions required for the neonate. This makes access to distant MR scanners possible. Fast imaging sequences reduce the overall scanning time and reduce the need for sedation or anaesthesia. These methods allow the vulnerable neonate to be imaged safely whilst providing essential imaging information for optimal clinical management.
Differential Subcellular Localization of Members of the
Toxoplasma gondii
Small Heat Shock Protein Family
Authors: de Miguel N. , Echeverria P. C. , Angel S. O. 
Published: December 2005

ABSTRACT

The results of this study describe the identification and characterization of the
Toxoplasma gondii
α-crystallin/small heat shock protein (sHsp) family. By database (
www.toxodb.org
) search, five parasite sHsps (Hsp20, Hsp21, Hsp28, Hsp29, and the previously characterized Hsp30/Bag1) were identified. As expected, they share the homologous α-crystallin domain, which is the key characteristic of sHsps. However, the N-terminal segment of each protein contains unique characteristics in size and sequence. Most
T. gondii
sHsps are constitutively expressed in tachyzoites and fully differentiated bradyzoites, with the exception of Hsp30/Bag1. Interestingly, by subcellular localization we observed that
T. gondii
sHsps are located in different compartments. Hsp20 is located at the apical end of the cell, Hsp28 is located inside the mitochondrion, Hsp29 showed a membrane-associated labeling, and Hsp21 appeared throughout the cytosol of the parasites. These particular differences in the immunostaining patterns suggest that their targets and functions might be different.
Envoy, a PAS/LOV Domain Protein of
Hypocrea jecorina
(Anamorph
Trichoderma reesei
), Modulates Cellulase Gene Transcription in Response to Light
Authors: Schmoll Monika , Franchi Lisa , Kubicek Christian P. 
Published: December 2005

ABSTRACT

Envoy, a PAS/LOV domain protein with similarity to the
Neurospora
light regulator Vivid, which has been cloned due to its lack of expression in a cellulase-negative mutant, links cellulase induction by cellulose to light signaling in
Hypocrea jecorina
. Despite their similarity,
env1
could not compensate for the lack of
vvd
function. Besides the effect of light on sporulation, we observed a reduced growth rate in constant light. An
env1
PAS−
mutant of
H. jecorina
grows significantly slower in the presence of light but remains unaffected in darkness compared to the wild-type strain QM9414.
env1
rapidly responds to a light pulse, with this response being different upon growth on glucose or glycerol, and it encodes a regulator essential for
H. jecorina
light tolerance. The induction of cellulase transcription in
H. jecorina
by cellulose is enhanced by light in the wild-type strain QM9414 compared to that in constant darkness, whereas a delayed induction in light and only a transient up-regulation in constant darkness of
cbh1
was observed in the
env1
PAS−
mutant. However, light does not lead to cellulase expression in the absence of an inducer. We conclude that Envoy connects the light response to carbon source signaling and thus that light must be considered an additional external factor influencing gene expression analysis in this fungus.
Regulation and Recovery of Functions of
Saccharomyces cerevisiae
Chaperone BiP/Kar2p after Thermal Insult
Authors: Seppä Laura , Makarow Marja 
Published: December 2005

ABSTRACT

We described earlier a novel mode of regulation of Hsp104, a cytosolic chaperone directly involved in the refolding of heat-denatured proteins, and designated it delayed upregulation, or DUR. When
Saccharomyces cerevisiae
cells grown at the physiological temperature of 24°C, preconditioned at 37°C, and treated briefly at 50°C were shifted back to 24°C, Hsp104 expression was strongly induced after 2.5 h of recovery and returned back to normal after 5 h. Here we show that the endoplasmic reticulum (ER) chaperones BiP/Kar2p and Lhs1p and the mitochondrial chaperone Hsp78 were also upregulated at the physiological temperature during recovery from thermal insult. The heat shock element (HSE) in the
KAR2
promoter was found to be sufficient to drive DUR. The unfolded protein element could also evoke DUR, albeit weakly, in the absence of a functional HSE. BiP/Kar2p functions in ER translocation and assists protein folding. Here we found that the synthesis of new BiP/Kar2p molecules was negligible for more than an hour after the shift of the cells from 50°C to 24°C. Concomitantly, ER translocation was blocked, suggesting that preexisting BiP/Kar2p molecules or other necessary proteins were not functioning. Translocation resumed concomitantly with enhanced synthesis of BiP/Kar2p after 3 h of recovery, after which ER exit and protein secretion also resumed. For a unicellular organism like
S. cerevisiae
, conformational repair of denatured proteins is the sole survival strategy. Chaperones that refold proteins in the cytosol, ER, and mitochondria of
S. cerevisiae
appear to be subject to DUR to ensure survival after thermal insults.
The Polybasic Juxtamembrane Region of Sso1p Is Required for SNARE Function In Vivo
Authors: Van Komen Jeffrey S. , Bai Xiaoyang , Rodkey Travis L. , Schaub Johanna , McNew James A. 
Published: December 2005

ABSTRACT

Exocytosis
in
Saccharomyces cerevisiae
requires the specific interaction
between the plasma membrane t-SNARE complex (Sso1/2p;Sec9p)and a vesicular v-SNARE (Snc1/2p). While SNARE proteins drive membrane
fusion, many aspects of SNARE assembly and regulation are ill defined.
Plasma membrane syntaxin homologs (including Sso1p) contain a highly
charged juxtamembrane region between the transmembrane helix and the“
SNARE domain” or core complex domain. We examined this
region in vitro and in vivo by targeted sequence modification,
including insertions and replacements. These modified Sso1 proteins
were expressed as the sole copy of Sso in
S. cerevisiae
and
examined for viability. We found that mutant Sso1 proteins with
insertions or duplications show limited function, whereas replacement
of as few as three amino acids preceding the transmembrane domain
resulted in a nonfunctional SNARE in vivo. Viability is also maintained
when two proline residues are inserted in the juxtamembrane of Sso1p,
suggesting that helical continuity between the transmembrane domain and
the core coiled-coil domain is not absolutely required. Analysis of
these mutations in vitro utilizing a reconstituted fusion assay
illustrates that the mutant Sso1 proteins are only moderately impaired
in fusion. These results suggest that the sequence of the juxtamembrane
region of Sso1p is vital for function in vivo, independent of the
ability of these proteins to direct membrane
fusion.
An
Ustilago maydis
Septin Is Required for Filamentous Growth in Culture and for Full Symptom Development on Maize
Authors: Boyce Kylie J. , Chang Howard , D'Souza Cletus A. , Kronstad James W. 
Published: December 2005

ABSTRACT

During maize infection, the fungal pathogen
Ustilago maydis
undergoes a dimorphic transition from budding, yeast-like cells to a filamentous dikaryon that proliferates in the host. This transition is regulated by mating and environmental signals. Septation is likely to be important in the growth of the infectious dikaryon because of the need to maintain specific cellular compartments during dikaryotic growth. Recently, we found that the transcript level for a septin gene was influenced by the conserved cyclic AMP (cAMP)/protein kinase A signaling pathway that participates in regulating dimorphism in
U. maydis
. In this study, we describe the detailed analysis of the function of this septin gene, designated
sep3
, in the growth, development, and pathogenesis of
U. maydis
. We show that
sep3
is required for normal cellular morphology and the division of budding haploid cells. The gene is also required for lipid-induced filamentous growth in culture but not during the formation of mating filaments on agar medium or in planta. Strains with a deletion in
sep3
have a reduction in symptom development in maize, with filamentous cells in planta displaying morphological defects. In addition,
sep3
influences the differentiation of hyphae into teliospores and the germination of these teliospores to produce the meiotic haploid progeny that complete the disease life cycle. Finally, the deletion of
sep3
was found to influence the multiple budding phenotype of a mutant with a defect in the regulatory subunit of protein kinase A. This result is consistent with a link between
sep3
and the control of morphogenesis by cAMP signaling. Overall, this study highlights the importance of regulating septation and changes in morphology during phytopathogenesis.
MYST Family Histone Acetyltransferases in the Protozoan Parasite
Toxoplasma gondii
Authors: Smith Aaron T. , Tucker-Samaras Samantha D. , Fairlamb Alan H. , Sullivan William J. 
Published: December 2005

ABSTRACT

The restructuring of chromatin precedes tightly regulated events such as DNA transcription, replication, and repair. One type of chromatin remodeling involves the covalent modification of nucleosomes by histone acetyltransferase (HAT) complexes. The observation that apicidin exerts antiprotozoal activity by targeting a histone deacetyltransferase has prompted our search for more components of the histone modifying machinery in parasitic protozoa. We have previously identified GNAT family HATs in the opportunistic pathogen
Toxoplasma gondii
and now describe the first MYST (named for members MOZ, Ybf2/Sas3, Sas2, and Tip60) family HATs in apicomplexa (TgMYST-A and -B). The TgMYST-A genomic locus is singular and generates a ∼3.5-kb transcript that can encode two proteins of 411 or 471 amino acids. TgMYST-B mRNA is ∼7.0 kb and encodes a second MYST homologue. In addition to the canonical MYST HAT catalytic domain, both TgMYST-A and -B possess an atypical C2HC zinc finger and a chromodomain. Recombinant TgMYST-A exhibits a predilection to acetylate histone H4 in vitro at lysines 5, 8, 12, and 16. Antibody generated to TgMYST-A reveals that both the long and short (predominant) versions are present in the nucleus and are also plentiful in the cytoplasm. Moreover, both TgMYST-A forms are far more abundant in rapidly replicating parasites (tachyzoites) than encysted parasites (bradyzoites). A bioinformatics survey of the
Toxoplasma
genome reveals numerous homologues known to operate in native MYST complexes. The characterization of TgMYST HATs represents another important step toward understanding the regulation of gene expression in pathogenic protozoa and provides evolutionary insight into how these processes operate in eukaryotic cells in general.
Gene Set Coregulated by the
Saccharomyces cerevisiae
Nonsense-Mediated mRNA Decay Pathway
Authors: Taylor Rachel , Kebaara Bessie Wanja , Nazarenus Tara , Jones Ashley , Yamanaka Rena , Uhrenholdt Rachel , Wendler Jason P. , Atkin Audrey L. 
Published: December 2005

ABSTRACT

The nonsense-mediated mRNA decay (NMD) pathway has historically been thought of as an RNA surveillance system that degrades mRNAs with premature translation termination codons, but the NMD pathway of
Saccharomyces cerevisiae
has a second role regulating the decay of some wild-type mRNAs. In
S. cerevisiae
, a significant number of wild-type mRNAs are affected when NMD is inactivated. These mRNAs are either wild-type NMD substrates or mRNAs whose abundance increases as an indirect consequence of NMD. A current challenge is to sort the mRNAs that accumulate when NMD is inactivated into direct and indirect targets. We have developed a bioinformatics-based approach to address this challenge. Our approach involves using existing genomic and function databases to identify transcription factors whose mRNAs are elevated in NMD-deficient cells and the genes that they regulate. Using this strategy, we have investigated a coregulated set of genes. We have shown that NMD regulates accumulation of
ADR1
and
GAL4
mRNAs, which encode transcription activators, and that Adr1 is probably a transcription activator of
ATS1
. This regulation is physiologically significant because overexpression of
ADR1
causes a respiratory defect that mimics the defect seen in strains with an inactive NMD pathway. This strategy is significant because it allows us to classify the genes regulated by NMD into functionally related sets, an important step toward understanding the role NMD plays in the normal functioning of yeast cells.
Enzymes of the Heme Biosynthetic Pathway in the Nonphotosynthetic Alga
Polytomella
sp
Authors: Atteia Ariane , van Lis Robert , Beale Samuel I. 
Published: December 2005

ABSTRACT

Heme
biosynthesis involves a number of enzymatic steps which in eukaryotes
take place in different cell compartments. Enzyme compartmentalization
differs between photosynthetic and nonphotosynthetic eukaryotes. Here
we investigated the structures and subcellular localizations of three
enzymes involved in the heme pathway in
Polytomella
sp., a
colorless alga evolutionarily related to the green alga
Chlamydomonas reinhardtii
. Functional complementation of
Escherichia coli
mutant strains was used to isolate cDNAs
encoding three heme biosynthetic enzymes, glutamate-1-semialdehyde
aminotransferase, protoporphyrinogen IX oxidase, and ferrochelatase.
All three proteins show highest similarity to their counterparts in
photosynthetic organisms, including
C. reinhardtii
. All three
proteins have N-terminal extensions suggestive of intracellular
targeting, and immunoblot studies indicate their enrichment in a dense
cell fraction that is enriched in amyloplasts. These results suggest
that even though the plastids of
Polytomella
sp. are not
photosynthetically active, they are the major site of heme
biosynthesis. The presence of a gene for glutamate-1-semialdehyde
aminotransferase suggests that
Polytomella
sp. uses the
five-carbon pathway for synthesis of the heme precursor
5-aminolevulinic
acid.
Sequencing of Random
Euplotes crassus
Macronuclear Genes Supports a High Frequency of +1 Translational Frameshifting
Authors: Klobutcher Lawrence A. 
Published: December 2005

ABSTRACT

Programmed translational frameshifts have been identified in genes from a broad range of organisms, but typically only a very few genes in a given organism require a frameshift for expression. In contrast, a recent analysis of gene sequences available in GenBank from ciliates in the genus
Euplotes
indicated that >5% required one or more +1 translational frameshifts to produce their predicted protein products. However, this sample of genes was nonrandom, biased, and derived from multiple
Euplotes
species. To test whether there truly is an abundance of frameshift genes in
Euplotes
, and to more accurately assess their frequency, we sequenced a random sample of 25 cloned genes/macronuclear DNA molecules from
Euplotes crassus
. Three new candidate +1 frameshift genes were identified in the sample that encode a membrane occupation and recognition nexus (MORN) repeat protein, a C
2
H
2
-type zinc finger protein, and a Ser/Thr protein kinase. Reverse transcription-PCR analyses indicate that all three genes are expressed in vegetatively proliferating cells and that the mRNAs retain the requirement of a frameshift. Although the sample of sequenced genes is relatively small, the results indicate that the frequency of genes requiring frameshifts in
E. crassus
is between 3.7% and 31.7% (at a 95% confidence interval). The current and past data also indicate that frameshift sites are found predominantly in genes that likely encode nonabundant proteins in the cell.
RNA-Binding Domain Proteins in Kinetoplastids: a Comparative Analysis
Authors: De Gaudenzi Javier , Frasch Alberto C. , Clayton Christine 
Published: December 2005

ABSTRACT

RNA-binding proteins are important in many aspects of RNA processing, function, and destruction. One class of such proteins contains the RNA recognition motif (RRM), which consists of about 90 amino acid residues, including the canonical RNP1 octapeptide: (K/R)G(F/Y)(G/A)FVX(F/Y). We used a variety of homology searches to classify all of the RRM proteins of the three kinetoplastids
Trypanosoma brucei
,
Trypanosoma cruzi
, and
Leishmania major
. All three organisms have similar sets of RRM-containing protein orthologues, suggesting common posttranscriptional processing and regulatory pathways. Of the 75 RRM proteins identified in
T. brucei
, only 13 had clear homologues in other eukaryotes, although 8 more could be given putative functional assignments. A comparison with the 18 RRM proteins of the obligate intracellular parasite
Encephalitozoon cuniculi
revealed just 3 RRM proteins which appear to be conserved at the primary sequence level throughout eukaryotic evolution: poly(A) binding protein, the rRNA-processing protein MRD1, and the nuclear cap binding protein.
Nd6p, a Novel Protein with RCC1-Like Domains Involved in Exocytosis in
Paramecium tetraurelia
Authors: Gogendeau Delphine , Keller Anne-Marie , Yanagi Akira , Cohen Jean , Koll France 
Published: December 2005

ABSTRACT

In
Paramecium tetraurelia
, the regulated secretory pathway of dense core granules called trichocysts can be altered by mutation and genetically studied. Seventeen nondischarge (ND) genes controlling exocytosis have already been identified by a genetic approach. The site of action of the studied mutations is one of the three compartments, the cytosol, trichocyst, or plasma membrane. The only ND genes cloned to date correspond to mutants affected in the cytosol or in the trichocyst compartment. In this work, we investigated a representative of the third compartment, the plasma membrane, by cloning the
ND6
gene. This gene encodes a 1,925-amino-acid protein containing two domains homologous to the regulator of chromosome condensation 1 (RCC1). In parallel, 10 new alleles of the
ND6
gene were isolated. Nine of the 12 available mutations mapped in the RCC1-like domains, showing their importance for the Nd6 protein (Nd6p) function. The RCC1 protein is well known for its guanine exchange factor activity towards the small GTPase Ran but also for its involvement in membrane fusion during nuclear envelope assembly. Other proteins with RCC1-like domains are also involved in intracellular membrane fusion, but none has been described yet as involved in exocytosis. The case of Nd6p is thus the first report of such a protein with a documented role in exocytosis.
The Plasmodial Surface Anion Channel Is Functionally Conserved in Divergent Malaria Parasites
Authors: Lisk Godfrey , Desai Sanjay A. 
Published: December 2005

ABSTRACT

The plasmodial surface anion channel (PSAC), a novel ion channel induced on human erythrocytes infected with
Plasmodium falciparum
, mediates increased permeability to nutrients and presumably supports intracellular parasite growth. Isotope flux studies indicate that other malaria parasites also increase the permeability of their host erythrocytes, but the precise mechanisms are unknown. Channels similar to PSAC or alternative mechanisms, such as the upregulation of endogenous host transporters, might fulfill parasite nutrient demands. Here we evaluated these possibilities with rhesus monkey erythrocytes infected with
Plasmodium knowlesi
, a parasite phylogenetically distant from
P. falciparum
. Tracer flux and osmotic fragility studies revealed dramatically increased permeabilities paralleling changes seen after
P. falciparum
infection. Patch-clamp of
P. knowlesi
-infected rhesus erythrocytes revealed an anion channel with striking similarities to PSAC: its conductance, voltage-dependent gating, pharmacology, selectivity, and copy number per infected cell were nearly identical. Our findings implicate a family of unusual anion channels highly conserved on erythrocytes infected with various malaria parasites. Together with PSAC's exposed location on the host cell surface and its central role in transport changes after infection, this conservation supports development of antimalarial drugs against the PSAC family.