bluuebunny/crossref_metadata_2025_split huggingface dataset:
Common cellular events occur during wound healing and organ regeneration in the sea cucumber Holothuria glaberrima
Authors: San Miguel-Ruiz José E , García-Arrarás José E 
Published: October 2007

Abstract
Background
All animals possess some type of tissue repair mechanism. In some species, the capacity to repair tissues is limited to the healing of wounds. Other species, such as echinoderms, posses a striking repair capability that can include the replacement of entire organs. It has been reported that some mechanisms, namely extracellular matrix remodeling, appear to occur in most repair processes. However, it remains unclear to what extent the process of organ regeneration, particularly in animals where loss and regeneration of complex structures is a programmed natural event, is similar to wound healing. We have now used the sea cucumber Holothuria glaberrima to address this question.

Results
Animals were lesioned by making a 3–5 mm transverse incision between one of the longitudinal muscle pairs along the bodywall. Lesioned tissues included muscle, nerve, water canal and dermis. Animals were allowed to heal for up to four weeks (2, 6, 12, 20, and 28 days post-injury) before sacrificed. Tissues were sectioned in a cryostat and changes in cellular and tissue elements during repair were evaluated using classical dyes, immmuohistochemistry and phalloidin labeling. In addition, the temporal and spatial distribution of cell proliferation in the animals was assayed using BrdU incorporation. We found that cellular events associated with wound healing in H. glaberrima correspond to those previously shown to occur during intestinal regeneration. These include: (1) an increase in the number of spherule-containing cells, (2) remodeling of the extracellular matrix, (3) formation of spindle-like structures that signal dedifferentiation of muscle cells in the area flanking the lesion site and (4) intense cellular division occurring mainly in the coelomic epithelium after the first week of regeneration.

Conclusion
Our data indicate that H. glaberrima employs analogous cellular mechanisms during wound healing and organ regeneration. Thus, it is possible that regenerative limitations in some organisms are due either to the absence of particular mechanisms associated with repair or the inability of activating the repair process in some tissues or stages.
Assisted Reproductive Technology affects developmental kinetics, H19 Imprinting Control Region methylation and H19gene expression in individual mouse embryos
Authors: Fauque Patricia , Jouannet Pierre , Lesaffre Corinne , Ripoche Marie-Anne , Dandolo Luisa , Vaiman Daniel , Jammes Hélène 
Published: October 2007

Abstract
Background
In the last few years, an increase in imprinting anomalies has been reported in children born from Assisted Reproductive Technology (ART). Various clinical and experimental studies also suggest alterations of embryo development after ART. Therefore, there is a need for studying early epigenetic anomalies which could result from ART manipulations, especially on single embryos. In this study, we evaluated the impact of superovulation, in vitro fertilization (IVF) and embryo culture conditions on proper genomic imprinting and blastocyst development in single mouse embryos.
In this study, different experimental groups were established to obtain embryos from superovulated and non-superovulated females, either from in vivo or in vitro fertilized oocytes, themselves grown in vitro or not. The embryos were cultured either in M16 medium or in G1.2/G2.2 sequential medium. The methylation status of H19 Imprinting Control Region (ICR) and H19 promoter was assessed, as well as the gene expression level of H19, in individual blastocysts. In parallel, we have evaluated embryo cleavage kinetics and recorded morphological data.

Results
We show that:
1. The culture medium influences early embryo development with faster cleavage kinetics for culture in G1.2/G2.2 medium compared to M16 medium.
2. Epigenetic alterations of the H19 ICR and H19 PP are influenced by the fertilization method since methylation anomalies were observed only in the in vitro fertilized subgroup, however to different degrees according to the culture medium.
3. Superovulation clearly disrupted H19 gene expression in individual blastocysts. Moreover, when embryos were cultured in vitro after either in vivo or in vitro fertilization, the percentage of blastocysts which expressed H19 was higher in G1.2/G2.2 medium compared to M16.

Conclusion
Compared to previous reports utilizing pools of embryos, our study enables us to emphasize a high individual variability of blastocysts in the H19 ICR and H19 promoter methylation and H19 gene expression, with a striking effect of each manipulation associated to ART practices. Our results suggest that H19 could be used as a sensor of the epigenetic disturbance of the utilized techniques.
Molecular evolution of the human SRPX2 gene that causes brain disorders of the Rolandic and Sylvian speech areas
Authors: Royer Barbara , Soares Dinesh C , Barlow Paul N , Bontrop Ronald E , Roll Patrice , Robaglia-Schlupp Andrée , Blancher Antoine , Levasseur Anthony , Cau Pierre , Pontarotti Pierre , Szepetowski Pierre 
Published: October 2007

Abstract

Background
The X-linked SRPX2 gene encodes a Sushi Repeat-containing Protein of unknown function and is mutated in two disorders of the Rolandic/Sylvian speech areas. Since it is linked to defects in the functioning and the development of brain areas for speech production, SRPX2 may thus have participated in the adaptive organization of such brain regions. To address this issue, we have examined the recent molecular evolution of the SRPX2 gene.

Results
The complete coding region was sequenced in 24 human X chromosomes from worldwide populations and in six representative nonhuman primate species. One single, fixed amino acid change (R75K) has been specifically incorporated in human SRPX2 since the human-chimpanzee split. The R75K substitution occurred in the first sushi domain of SRPX2, only three amino acid residues away from a previously reported disease-causing mutation (Y72S). Three-dimensional structural modeling of the first sushi domain revealed that Y72 and K75 are both situated in the hypervariable loop that is usually implicated in protein-protein interactions. The side-chain of residue 75 is exposed, and is located within an unusual and SRPX-specific protruding extension to the hypervariable loop. The analysis of non-synonymous/synonymous substitution rate (Ka/Ks) ratio in primates was performed in order to test for positive selection during recent evolution. Using the branch models, the Ka/Ks ratio for the human branch was significantly different (p = 0.027) from that of the other branches. In contrast, the branch-site tests did not reach significance. Genetic analysis was also performed by sequencing 9,908 kilobases (kb) of intronic SRPX2 sequences. Despite low nucleotide diversity, neither the HKA (Hudson-Kreitman-Aguadé) test nor the Tajima's D test reached significance.

Conclusion
The R75K human-specific variation occurred in an important functional loop of the first sushi domain of SRPX2, indicating that this evolutionary mutation may have functional importance; however, positive selection for R75K could not be demonstrated. Nevertheless, our data contribute to the first understanding of molecular evolution of the human SPRX2 gene. Further experiments are now required in order to evaluate the possible consequences of R75K on SRPX2 interactions and functioning.
Hfq stimulates the activity of the CCA-adding enzyme
Authors: Scheibe Marion , Bonin Sonja , Hajnsdorf Eliane , Betat Heike , Mörl Mario 
Published: October 2007

Abstract

Background
The bacterial Sm-like protein Hfq is known as an important regulator involved in many reactions of RNA metabolism. A prominent function of Hfq is the stimulation of RNA polyadenylation catalyzed by E. coli poly(A) polymerase I (PAP). As a member of the nucleotidyltransferase superfamily, this enzyme shares a high sequence similarity with an other representative of this family, the tRNA nucleotidyltransferase that synthesizes the 3'-terminal sequence C-C-A to all tRNAs (CCA-adding enzyme). Therefore, it was assumed that Hfq might not only influence the poly(A) polymerase in its specific activity, but also other, similar enzymes like the CCA-adding enzyme.

Results
Based on the close evolutionary relation of these two nucleotidyltransferases, it was tested whether Hfq is a specific modulator acting exclusively on PAP or whether it also influences the activity of the CCA-adding enzyme. The obtained data indicate that the reaction catalyzed by this enzyme is substantially accelerated in the presence of Hfq. Furthermore, Hfq binds specifically to tRNA transcripts, which seems to be the prerequisite for the observed effect on CCA-addition.

Conclusion
The increase of the CCA-addition in the presence of Hfq suggests that this protein acts as a stimulating factor not only for PAP, but also for the CCA-adding enzyme. In both cases, Hfq interacts with RNA substrates, while a direct binding to the corresponding enzymes was not demonstrated up to now (although experimental data indicate a possible interaction of PAP and Hfq). So far, the basic principle of these stimulatory effects is not clear yet. In case of the CCA-adding enzyme, however, the presented data indicate that the complex between Hfq and tRNA substrate might enhance the product release from the enzyme.
Systematic analysis of alternative first exons in plant genomes
Authors: Chen Wei-Hua , Lv Guanting , Lv Congying , Zeng Changqing , Hu Songnian 
Published: October 2007

Abstract

Background
Alternative splicing (AS) contributes significantly to protein diversity, by selectively using different combinations of exons of the same gene under certain circumstances. One particular type of AS is the use of alternative first exons (AFEs), which can have consequences far beyond the fine-tuning of protein functions. For example, AFEs may change the N-termini of proteins and thereby direct them to different cellular compartments. When alternative first exons are distant, they are usually associated with alternative promoters, thereby conferring an extra level of gene expression regulation. However, only few studies have examined the patterns of AFEs, and these analyses were mainly focused on mammalian genomes. Recent studies have shown that AFEs exist in the rice genome, and are regulated in a tissue-specific manner. Our current understanding of AFEs in plants is still limited, including important issues such as their regulation, contribution to protein diversity, and evolutionary conservation.

Results
We systematically identified 1,378 and 645 AFE-containing clusters in rice and Arabidopsis, respectively. From our data sets, we identified two types of AFEs according to their genomic organisation. In genes with type I AFEs, the first exons are mutually exclusive, while most of the downstream exons are shared among alternative transcripts. Conversely, in genes with type II AFEs, the first exon of one gene structure is an internal exon of an alternative gene structure. The functionality analysis indicated about half and ~19% of the AFEs in Arabidopsis and rice could alter N-terminal protein sequences, and ~5% of the functional alteration in type II AFEs involved protein domain addition/deletion in both genomes. Expression analysis indicated that 20~66% of rice AFE clusters were tissue- and/or development- specifically transcribed, which is consistent with previous observations; however, a much smaller percentage of Arabidopsis AFEs was regulated in this manner, which suggests different regulation mechanisms of AFEs between rice and Arabidopsis. Statistical analysis of some features of AFE clusters, such as splice-site strength and secondary structure formation further revealed differences between these two species. Orthologous search of AFE-containing gene pairs detected only 19 gene pairs conserved between rice and Arabidopsis, accounting only for a few percent of AFE-containing clusters.

Conclusion
Our analysis of AFE-containing genes in rice and Arabidopsis indicates that AFEs have multiple functions, from regulating gene expression to generating protein diversity. Comparisons of AFE clusters revealed different features in the two plant species, which indicates that AFEs may have evolved independently after the separation of rice (a model monocot) and Arabidopsis (a model dicot).
Clinical and neuroimaging correlates of antiphospholipid antibodies in multiple sclerosis: a preliminary study
Authors: Bidot Carlos J , Horstman Lawrence L , Jy Wenche , Jimenez Joaquin J , Bidot Carlos , Ahn Yeon S , Alexander J Steven , Gonzalez-Toledo Eduardo , Kelley Roger E , Minagar Alireza 
Published: October 2007

Abstract

Background
The presence of antiphospholipid antibodies (APLA) in multiple sclerosis (MS) patients has been reported frequently but no clear relationship between APLA and the clinical and neuroimaging features of MS have heretofore been shown. We assessed the clinical and neuroimaging features of MS patients with plasma APLA.

Methods
A consecutive cohort of 24 subjects with relapsing-remitting (RR) MS were studied of whom 7 were in remission (Rem) and 17 in exacerbation (Exc). All subjects were examined and underwent MRI of brain. Patients' plasma was tested by standard ELISA for the presence of both IgM and IgG antibodies using a panel of 6 targets: cardiolipin (CL), β2 glycoprotein I (β2GPI), Factor VII/VIIa (FVIIa), phosphatidylcholine (PC), phosphatidylserine (PS) and phosphatidylethanolamine (PE).

Results
In exacerbation up to 80% of MS subjects had elevated titers of IgM antibodies directed against the above antigens. However, in remission, less than half of MS patients had elevated titers of IgM antibodies against one or more of the above antigens. This difference was significant, p < 0.01, for all 6 target antigens. Interestingly, none of the MS patients had elevated plasma titers of IgG against any of the target antigens tested. Correlation analysis between MRI enhancing lesions and plasma levels of APLA revealed high correlation for aPC, aPS and aFVIIa (p ≤ 0.0065), a trend for aPE and aCL (p = 0.056), and no correlation for aβ2GP1. The strongest correlation was for aFVIIa, p = 0.0002.

Conclusion
The findings of this preliminary study show that increased APLA IgM is associated with exacerbations of MS. Currently, the significance of this association in pathogenesis of MS remains unknown. However, systematic longitudinal studies to measure APLA in larger cohorts of patients with relapsing-remitting MS, particularly before and after treatment with immunomodulatory agents, are needed to confirm these preliminary findings.
Validity and reliability of the multidimensional health locus of control scale for college students
Authors: Moshki Mahdi , Ghofranipour Fazlollah , Hajizadeh Ebrahim , Azadfallah Parviz 
Published: October 2007

Abstract

Background
The purpose of the present study was to assess the validity and reliability of Form A of Multidimensional Health Locus of Control scales in Iran. Health locus of control is one of the most widely measured parameters of health belief for the planning of health education programs.

Methods
496 university students participated in this study. The reliability coefficients were calculated in three different methods: test-retest, parallel forms and Cronbach alpha. In order to survey validity of the scale we used three methods including content validity, concurrent validity and construct validity.

Results
We established the content validity of the Persian translation by translating (and then back-translating) each item from the English version into the Persian version. The concurrent validity of the questionnaire, as measured by Levenson's IPC scale was .57 (P < .001), .49 (P < .01) and .53 (P < .001) for IPC, respectively. Exploratory principal components analysis supported a three-factor structure that items loading adequately on each factor. Moreover, the approximate orthogonal of the dimensions were obtained through correlation analyses. In addition, the reliability results were acceptable, too.

Conclusion
The results showed that the reliability and validity of Persian Form A of MHLC was acceptable and respectable and is suggested as an applicable criterion for similar studies in Iran.
Diffusion of good practices of care and decline of the association with case volume: the example of breast conserving surgery
Authors: Fedeli Ugo , Alba Natalia , Schievano Elena , Visentin Cristiana , Rosato Rosalba , Zorzi Manuel , Ruscitti Giancarlo , Spolaore Paolo 
Published: October 2007

Abstract
Background
Several previous studies conducted on cancer registry data and hospital discharge records (HDR) have found an association between hospital volume and the recourse to breast conserving surgery (BCS) for breast cancer. The aim of the current study is to depict concurrent time trends in the recourse to BCS and its association with hospital volume.

Methods
Admissions of breast cancer patients for BCS or mastectomy in the period 2000–2004 were identified from the discharge database of the Veneto Region (Italy). The role of procedural volume (low < 50, medium 50–100, high > 100 breast cancer surgeries/year), and of individual risk factors obtainable from HDR was assessed through a hierarchical log-binomial regression.

Results
Overall, the recourse to BCS was higher in medium (risk ratio = 1.12, 95% confidence interval 1.07–1.18) and high-volume (1.09, 1.03–1.14) compared to low-volume hospitals. The proportion of patients treated in low-volume hospitals dropped from 22% to 12%, with a concurrent increase in the activity of medium-volume providers. The increase over time in breast conservation (globally from 56% to 67%) was steeper in the categories of low- and medium-volume hospitals with respect to high caseload.

Conclusion
The growth in the recourse to BCS was accompanied by a decline of the association with hospital volume; larger centers probably acted as early adopters of breast conservation strategies that subsequently spread to smaller providers.
Microfinance investments in quality at private clinics in Uganda: a case-control study
Authors: Seiber Eric E , Robinson Amara L 
Published: October 2007

Abstract
Background
Small private-sector health care providers can play an important role in meeting the developing country health care needs, but a lack of credit can prove major constraint to small-provider expansion. This study examines the potential of small, microfinance loans to strengthen the private health sector and improve access to quality preventive and curative health services in Uganda.

Methods
This study estimates logistic regressions using 2,387 client exit interviews to assess the impact of microfinance loans on perceived quality and the viability and sustainability of small, private clinics.

Results
The study finds perceived quality improved with loan recipients' clients being more likely to choose clinics on the basis of drug availability, fair charges, cleanliness, and confidentiality. In addition, the assessment found evidence of increased client flows, but the changes produced mixed results for sustainability with respondents being only half as likely to "always" visit a particular clinic.

Conclusion
The results indicate that the microfinance program improved perceived quality at loan recipient clinics, especially as reliable drug outlets.
Implication of BRCA2 -26G>A 5' untranslated region polymorphism in susceptibility to sporadic breast cancer and its modulation by p53codon 72 Arg>Pro polymorphism
Authors: Gochhait Sailesh , Bukhari Syed Irfan Ahmad , Bairwa Narendra , Vadhera Shivani , Darvishi Katayoon , Raish Mohammad , Gupta Pawan , Husain Syed Akhtar , Bamezai Rameshwar NK 
Published: October 2007

Abstract
Introduction
The absence of mutation or promoter hypermethylation in the BRCA2 gene in the majority of breast cancer cases has indicated alternative ways of its involvement, deregulated expression being one possibility. We show how a polymorphism in the 5' untranslated region (UTR) of BRCA2 can serve as one such factor. Based on the hypothesis that variants of genes involved in the same pathway can influence the risk provided for breast cancer, the status of p53 codon 72 polymorphism was also investigated and a possible interaction between the polymorphisms was examined.

Methods
The luciferase reporter assay followed by RNA secondary structure analysis was used for the functional characterization of -26 5' UTR G>A polymorphism in BRCA2. The genotype and the allele frequency for the polymorphisms were determined and relative risk adjusted for age was calculated in a case-control study of 576 individuals (243 patients and 333 controls) from north India.

Results
-26 G>A polymorphism in the 5' UTR of BRCA2 was found to be functional whereby the A allele increased the reporter gene expression by twice that of the G allele in MCF-7 (P = 0.003) and HeLa (P = 0.013) cells. RNA secondary structure analysis by two different programs predicted the A allele to alter the stability of a loop in the vicinity of the translation start site. Its direct implication in breast cancer became evident by a case-control study in which the heterozygous genotype was found to be protective in nature (Pheterozygote advantage model = 0.0005, odds ratio [OR] = 0.5, 95% confidence interval [CI] = 0.4 to 0.8), which was further supported by trends observed in a genomic instability study. The p53 codon 72 Arg homozygous genotype was found to be over-represented in patients (P = 0.0005, OR = 2.3, 95% CI = 1.4 to 3.6). The interaction study indicated an increased protection under simultaneous presence of protector genotypes of both the polymorphic loci (P = 0.0001, OR = 0.2, 95% CI = 0.1 to 0.4).

Conclusion
Our study shows that -26 5' UTR polymorphism in BRCA2 can modulate the fine-tuned regulation of the multifunctional gene BRCA2 and renders risk or protection according to the genotype status in the sporadic form of breast cancer, which is further influenced by the germline genetic backgrounds of codon 72 polymorphism of p53.