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Biomedical subjects

J Valcarcel

Publications and source records attributed to J Valcarcel.

10 recordsLinked to original sources
PubMed2005

Coronal and apical lesions, environmental factors: study in a modern and an archeological population.

Apical periodontitis (AP) are frequent findings in contemporary dental practice in association with dental pathology or dental care. They have also been studied from an anthropological background. The purpose of this study was to compare the prevalence of apical and dental lesions in an archeological Middle Ages sample and a modern population, and to evaluate the influence of environmental factors. Both the archaeological sample group and dental practice subjects were from southern France. The study included full mouth surveys of 252 individuals (2,780 teeth) from a historic necropolis and 223 subjects (5,678 teeth) randomly selected from the Gard area. Tooth wear, caries, and AP were accounted for clinically and radiographically according to specific indexes. Significant differences were found between period and age in the archeological sample as regards the main risk factors for AP. Antemortem teeth loss and dental wear had been reduced, whereas caries rates and AP had increased between archaeological and modern population. The AP ratio was associated with the level of dental care in the modern population. Although significant variations could be observed between archaeological periods, the rupture in E3 (sixteenth and seventeenth centuries) leads to consider the associated population as a premodern. However, it was found that although cultural and alimentary factors seemed to be the main risk factors in an archeological population, dental care seemed to have a strong influence on AP ratio in modern ones.

Adolescent↗
PubMed2005

A comparative analysis of periapical health based on historic and current data.

AIM: To compare periapical health using samples from prehistoric and historic periods until the present day, and to emphasize the major risk indicators for apical periodontitis (AP). METHODOLOGY: A comparative survey to assess periapical health was performed on five samples (525 individuals) drawn from different periods of history within the time frame 2000 BC to 2000 AD. Twenty-one binary risk indicators for AP were retained for a logistic regression model. The probability of a diseased tooth was defined from a two-level response variable based on the periapical index (PAI). An individual regression model was computed with partial least squares (PLS) regression model, based on the individual mean values of the nine retained risk indicators. RESULTS: Condensing osteitis, tooth wear, caries, root fillings and the presence of inadequate root fillings were associated with the PAI levels. The maxillary molars and recent time periods (contemporaneous and seventeenth century) were also risk indicators for the pathological condition. The PLS regression for individuals demonstrated correlations between risk factors. This multidimensional analysis indicated that the mean PAI was correlated mainly with caries and condensing osteitis. Condensing osteitis was more frequent in the mandibular than in the maxillary bone (P=0.001), and correlated with tooth wear in ancient periods. CONCLUSIONS: This comparative analysis demonstrated a significantly higher prevalence of AP in the contemporary period. The most important risk indicators for that period were the presence of inadequate root fillings, carious lesions and condensing osteitis.

Adolescent↗
PubMed2002

[Epidermal growth factor: a probable oral and digestive health protector].

The integrity of oral and digestive mucosa depend on many salivary components like the Epidermal Growth Factor (EGF). Sometimes indicative, sometimes stimulated or modulated factor of oral and digestive health, EGF appears as a clinical marker in neoplastic and inflammatory diseases. As cellular growth factor, it protects the digestive mucosa with stimulation of mucus production and with inhibition of gastric secretion. Equally implicated in healing process, it enhances this one, and determines, in patients, more or less sensibility to inflammatory damages. Its strategic place in various pathologies, as stomach ulcer and tumoral process, open research prospects with a real potential of repair and pronostic.

Biomarkers↗
PubMed2000

Nucleocytoplasmic shuttling of heterodimeric splicing factor U2AF.

The U2 small nuclear ribonucleoprotein auxiliary factor (U2AF) is a heterodimeric splicing factor composed of 65-kDa (U2AF(65)) and 35-kDa (U2AF(35)) subunits. The large subunit of U2AF recognizes the intronic polypyrimidine tract, a sequence located adjacent to the 3' splice site that serves as an important signal for both constitutive and regulated pre-mRNA splicing. The small subunit U2AF(35) interacts with the 3' splice site dinucleotide AG and is essential for regulated splicing. Like several other proteins involved in constitutive and regulated splicing, both U2AF(65) and U2AF(35) contain an arginine/serine-rich (RS) domain. In the present study we determined the role of RS domains in the subcellular localization of U2AF. Both U2AF(65) and U2AF(35) are shown to shuttle continuously between the nucleus and the cytoplasm by a mechanism that involves carrier receptors and is independent from binding to mRNA. The RS domain on either U2AF(65) or U2AF(35) acts as a nuclear localization signal and is sufficient to target a heterologous protein to the nuclear speckles. Furthermore, the results suggest that the presence of an RS domain in either U2AF subunit is sufficient to trigger the nucleocytoplasmic import of the heterodimeric complex. Shuttling of U2AF between nucleus and cytoplasm possibly represents a means to control the availability of this factor to initiate spliceosome assembly and therefore contribute to regulate splicing.

3T3 Cells↗
PubMed1997

Investigation of the Actinobacillus actinomycetemcomitans genome by pulsed field gel electrophoresis.

Pulsed field gel electrophoresis was used to investigate nineteen strains of Actinobacillus actinomycetemcomitans. The genome was found to contain a single chromosome whose size we estimate to be 2300 kb from the sum of restriction fragments generated with rare cutting endonucleases. We detected the presence of large plasmids with sizes ranging from 35 to 300 kb. In some strains, extrachromosomal elements constitute over 20% of the total genome. Comparison of the profiles of ApaI digests of the 19 strains showed a high degree of polymorphism with 13 different profiles, providing a new tool for epidemiological studies.

Aggregatibacter actinomycetemcomitans↗
PubMed1996

Bacterial leakage in endodontics: an improved method for quantification.

A new method for studying leakage of root fillings using the bacterium Pseudomonas fluorescens ATCC 13525 is described. The presence of the microorganism is detected by fluorimetry and can thus be used to measure the depth of penetration from the root apex toward the crown of the tooth. This system, applied to a number of methods of root canal filling, showed that procedures involving compaction of the gutta-percha gave a more effective seal than the use of a paste sealer with uncondensed gutta-percha. There was no statistically significant difference between the leakage results from the lateral, vertical, and thermomechanical condensed techniques.

Dental Leakage↗
PubMed1994

RNA splicing contributes to the generation of mature mRNAs of Borna disease virus, a non-segmented negative strand RNA virus.

We recently demonstrated that Borna disease virus (BDV) has a negative non-segmented single stranded (NNS) RNA genome, whose organization is similar to that of other members of the Mononegavirales order. However, we have also documented that in contrast to the rest of the NNS-RNA animal viruses, BDV replication and transcription occur in the nucleus of infected cells. Here, we provide evidence that BDV uses the host nuclear splicing machinery to generate some of the viral mRNAs, representing the first documentation of RNA splicing in NNS-RNA animal viruses. Possible implications of RNA splicing for the regulation of BDV gene expression are discussed.

Base Sequence↗
PubMed1976

Chief cell hyperplasia in the human carotid body at high altitudes; physiologic and pathologic significance.

The area occupied by parenchymal cells, in sections comprising the entire half of the surface of the carotid body, is significantly greater in people born and living at 14,350 feet than in those at sea level. The enlargement and increase in weight of the carotid bodies observed at high altitudes can thus be attributed to hyperplasia of parenchymal tissue. The proliferated cells have the morphology of type I chief cells and display marked vacuolation and depletion of yellow-green, naturally fluorescing, bioamine containing granules. Although unimportant variations in size and weight in relation to age occurred at sea level, it was found that the magnitude of the carotid body enlargement increased with age at high altitudes. The augmented carotid body size and weight in relation to age at high altitudes are associated with progressive chemoreceptor insensitivity. The physiologic and pathologic significance of these findings is discussed.

Adolescent↗
PubMedDate not supplied

A Raman spectroscopic investigation of dentin and enamel structures modified by lactic acid.

Confocal Raman microspectrometry allows a thorough molecular analysis of mineralised dental tissues. The output information is provided in the form of curves representing the intensity of the signal according to the frequency, and its mathematical exploitation permits all sorts of comparative and quantitative analyses. By this process, we investigated the in vitro action of lactic acid on enamel and dentin from human permanent teeth. Modifications due to the acidic attack essentially concern phosphate grouping PO(4)(3-), which represents the mineral phase in enamel and dentin (hydroxyapatite): on Raman spectra, changes in intensity of the PO(4)(3-) band are linked to the type of dentin, to its anatomical location, and to the age of the subject. The variability of the dentinal chemical structure was confirmed by a quantitative statistical analysis, revealing a significant spectral difference between coronal and root dentin.

Adult↗