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Biomedical subjects

C Duque

Publications and source records attributed to C Duque.

At least 19 recordsLinked to original sources
PubMed2006

Reactionary dentinogenesis after applying restorative materials and bioactive dentin matrix molecules as liners in deep cavities prepared in nonhuman primate teeth.

OBJECTIVE: The aim of this in vivo study was to evaluate the response of the pulp-dentin complex following application of resin-modified glass-ionomer cement, calcium hydroxide hard-setting cement and EDTA-soluble preparation of dentine matrix proteins (ESDP) in deep cavities prepared in non-human primate teeth. METHODS: Eighteen deep Class V buccal cavities were prepared in premolars of four capuccin monkeys. In Groups 1 and 2, the cavity floor was lined with ESDP or a resin-modified glass-ionomer cement (Vitrebond - 3M ESPE), respectively. In Group 3 (control), the cavity was lined with a hard setting calcium hydroxide cement (Dycal - Dentsply). The cavities were subsequently filled with amalgam. After 6 months, the animals were sacrificed and the teeth were prepared for microscopic assessment. Six-micron thick serial sections were stained with H/E, Masson's trichrome and Brown & Brenn techniques. RESULTS: No inflammatory pulpal response was observed for all experimental and control Groups. However, the amount of reactionary dentin deposition differed between groups in the rank order ESDP (Group 1) > calcium hydroxide (Group 3) > resin-modified glass-ionomer (Group 2). These differences were statistically significant. CONCLUSIONS: All materials were biocompatible when applied in deep cavities. ESDP stimulated higher deposition of reactionary dentin matrix than Vitrebond and Dycal.

Animals↗
PubMed2005

Takayasu's arteritis: what should the dentist know?

Takayasu's arteritis is a chronic inflammatory disease that affects large blood vessels, especially the aorta and/or its major branches. The condition presents with segmental lesions adjacent to normal, apparently unaffected, areas. The lesions include stenosis, occlusion, dilatations or aneurysm formations along the path of the affected artery. Because of the severity of the disease and the possibility of cardiovascular complications, patients with Takayasu's arteritis require medical treatment based on immunosuppressive and antihypertensive drugs, as well as regular follow up and surgical intervention in many instances. The aim of this paper was to describe the characteristics of Takayasu's arteritis, to report dental treatment carried out on an affected patient, and to discuss the main implications and care required during routine treatment for children in the dental office.

Amoxicillin↗
PubMed2001

Exudation of low molecular weight compounds (thiobismethane, methyl isocyanide, and methyl isothiocyanate) as a possible chemical defense mechanism in the marine sponge Ircinia felix.

The volatile constituents of the marine sponge Ircinia felix were obtained by dynamic headspace extraction and analyzed by HRGC, HRGC-MS and HRGC-Odor at sniffing port. Fifty-nine volatiles were identified for the first time in the odor of this sponge. Hydrocarbons (32.9%), alcohols (17.8%) and carbonyl compounds (16.0%) predominated in the sponge volatile profile, followed by esters (11.6%), halogen compounds (8.6%), ethers (7.7%), nitrogen and/or sulfur compounds (4.6%) and carboxylic acids (0.8%). Among the identified volatiles, thiobismethane (commonly known as dimethylsulfide), methyl isocyanide and methyl isothiocyanate were found to be responsible for the nauseating and toxic smell emitted by the sponge and for the antimicrobial activity detected in the volatile extract. Exudation experiments in aquarium and in situ conditions revealed that thiobismethane, methyl isocyanide and methyl isothiocyanate are continuously released by the sponge. Upon injury, the concentration of these volatiles increased strongly. Hence, these substances form a chemical protective barrier which may help these sponges avoid fouling, compete for space, prevent infection in the short term, and/or signal generalist predators regarding the existence of other toxic substances in the internal tissues.

Journal Article↗
PubMed2001

Glycosidically bound flavor compounds of cape gooseberry (Physalis peruviana L.).

The bound volatile fraction of cape gooseberry (Physalis peruviana L.) fruit harvested in Colombia has been examined by HRGC and HRGC-MS after enzymatic hydrolysis using a nonselective pectinase (Rohapect D5L). Forty bound volatiles could be identified, with 21 of them being reported for the first time in cape gooseberry. After preparative isolation of the glycosidic precursors on XAD-2 resin, purification by multilayer coil countercurrent chromatography and HPLC of the peracetylated glycosides were carried out. Structure elucidation by NMR, ESI-MS/MS, and optical rotation enabled the identification of (1S,2S)-1-phenylpropane-1,2-diol 2-O-beta-D-glucopyranoside (1) and p-menth-4(8)-ene-1,2-diol 1-O-alpha-L-arabinopyranosyl-(1-6)-beta-D-glucopyranoside (2). Both glycosides have been identified for the first time in nature. They could be considered as immediate precursors of 1-phenylpropane-1,2-diol and p-menth-4(8)-ene-1,2-diol, typical volatiles found in the fruit of cape gooseberry.

Counterimmunoelectrophoresis↗
PubMed2000

Autosomal, mtDNA, and Y-chromosome diversity in Amerinds: pre- and post-Columbian patterns of gene flow in South America.

To evaluate sex-specific differences in gene flow between Native American populations from South America and between those populations and recent immigrants to the New World, we examined the genetic diversity at uni- and biparental genetic markers of five Native American populations from Colombia and in published surveys from native South Americans. The Colombian populations were typed for five polymorphisms in mtDNA, five restriction sites in the beta-globin gene cluster, the DQA1 gene, and nine autosomal microsatellites. Elsewhere, we published results for seven Y-chromosome microsatellites in the same populations. Autosomal polymorphisms showed a mean G(ST) of 6.8%, in agreement with extensive classical marker studies of South American populations. MtDNA and Y-chromosome markers resulted in G(ST) values of 0.18 and 0.165, respectively. When only Y chromosomes of confirmed Amerind origin were used in the calculations (as defined by the presence of allele T at locus DYS199), G(ST) increased to 0.22. G(ST) values calculated from published data for other South American natives were 0.3 and 0.29 for mtDNA and Amerind Y chromosomes, respectively. The concordance of these estimates does not support an important difference in migration rates between the sexes throughout the history of South Amerinds. Admixture analysis of the Colombian populations suggests an asymmetric pattern of mating involving mostly immigrant men and native women.

Africa↗
PubMed2000

Strong Amerind/white sex bias and a possible Sephardic contribution among the founders of a population in northwest Colombia.

Historical and genetic evidences suggest that the recently founded population of Antioquia (Colombia) is potentially useful for the genetic mapping of complex traits. This population was established in the 16th-17th centuries through the admixture of Amerinds, Europeans, and Africans and grew in relative isolation until the late 19th century. To examine the origin of the founders of Antioquia, we typed 11 markers on the nonrecombining portion of the Y chromosome and four markers on mtDNA in a sample of individuals with confirmed Antioquian ancestry. The polymorphisms on the Y chromosome (five biallelic markers and six microsatellites) allow an approximation to the origin of founder men, and those on mtDNA identify the four major founder Native American lineages. These data indicate that approximately 94% of the Y chromosomes are European, 5% are African, and 1% are Amerind. Y-chromosome data are consistent with an origin of founders predominantly in southern Spain but also suggest that a fraction came from northern Iberia and that some possibly had a Sephardic origin. In stark contrast with the Y-chromosome, approximately 90% of the mtDNA gene pool of Antioquia is Amerind, with the frequency of the four Amerind founder lineages being closest to Native Americans currently living in the area. These results indicate a highly asymmetric pattern of mating in early Antioquia, involving mostly immigrant men and local native women. The discordance of our data with blood-group estimates of admixture suggests that the number of founder men was larger than that of women.

Africa, Northern↗
PubMed2000

An association study of bipolar mood disorder (type I) with the 5-HTTLPR serotonin transporter polymorphism in a human population isolate from Colombia.

The short variant of a functional length polymorphism in the promoter region of the serotonin transporter has been associated with several behavioural and psychiatric traits, including bipolar mood disorder. The same short allele has also been implicated as a modifier of the bipolar phenotype. Here we evaluate the etiologic/modifier role of this polymorphism in a case (N=103) / control (N=112) sample for bipolar mood disorder (type I) collected from an isolated South American population. We did not detect an association between bipolar disorder and the 5-HTT promoter polymorphism in this sample. However, an excess of the short allele was seen in younger cases and in cases with psychotic symptoms. When combined with data from the literature, the increased frequency of the short allele in patients with psychotic symptoms was statistically significant.

Age of Onset↗
PubMed2000

Oxygenated monoterpenoids from badea (Passiflora quadrangularis) fruit pulp.

The new monoterpenoids (2E)-2,6-dimethyl-2,5-heptadienoic acid, (2E)-2,6-dimethyl-2,5-heptadienoic acid beta-D-glucopyranosyl ester, (5E)-2,6-dimethyl-5,7-octadiene-2,3-diol, and (3E)-3,7-dimethyl-3-octene-1,2,6,7-tetrol were isolated from the fruit pulp of Passiflora quadrangularis along with the known 2,5-dimethyl-4-hydroxy-3(2H)-furanone beta-D-glucopyranoside.

Fruit↗
PubMed2000

Free and bound volatile composition and characterization of some glucoconjugates as aroma precursors in melón de olor fruit pulp (Sicana odorifera).

Free and glycosidically bound volatiles obtained from the fruit pulp of Sicana odorifera by liquid-liquid extraction and by chromatography, followed by enzymatic hydrolysis with Rohapect D5L, respectively, were analyzed by capillary gas chromatography (HRGC), HRGC-mass spectrometry (HRGC-MS), and HRGC-Olfatometry (HRGC-O) analyses. A total of 37 free volatiles was detected, with the major components being 3-methyl-2-butanol, 3-hydroxy-2-butanone, ethyl 3-hydroxybutanoate, and (Z)-3-hexenol. Among the 22 detected glycosidically bound compounds, 4-hydroxybenzyl methyl ether, 4-hydroxybenzyl alcohol, and 2-phenylethanol were found to be the major constituents. Additionally, two glucoconjugates were isolated in pure form by multilayer coil countercurrent chromatography (MLCCC) of the glycosidic extrac and further purification. Their structures were elucidated by MS and NMR analyses to be the novel [4-(beta-D-glucopyranosyloxy)benzyl] 2,3-dihydroxy-3-methylbutanoate 2, and the known 4-(beta-D-glucopyranosyloxy)benzyl alcohol 1. Compounds 1 and 2 are precursors of 4-hydroxybenzyl alcohol, one of the major volatiles generated by enzymatic hydrolysis of the glycosidic fraction.

Cucurbitaceae↗
PubMed1999

C(13)-Norisoprenoid glucoconjugates from lulo (Solanum quitoense L.) leaves.

With the aid of multilayer coil countercurrent chromatography, subsequent acetylation, and liquid chromatographic purification of a glycosidic mixture obtained from lulo (Solanum quitoense L.) leaves, three C(13)-norisoprenoid glucoconjugates were isolated in pure form. Their structures were elucidated by NMR, MS, and CD analyses to be the novel (6R,9R)-13-hydroxy-3-oxo-alpha-ionol 9-O-beta-D-glucopyranoside (4a), the uncommon (3S,5R,8R)-3, 5-dihydroxy-6,7-megastigmadien-9-one 5-O-beta-D-glucopyranoside (citroside A) (5a), and the known (6S,9R)-vomifoliol 9-O-beta-D-glucopyranoside (6a). Enzymatic treatment of compound 5a showed the formation of 3-hydroxy-7,8-didehydro-beta-ionone (7), an important lulo peeling volatile, which in its turn after chemical reduction and heated acid catalyzed rearrangement generates beta-damascenone (9) and 3-hydroxy-beta-damascone (10).

Fruit↗
PubMed1997

Novel fatty acid esters of (7E, 12E, 18R, 20Z)-variabilin from the marine sponge Ircinia felix.

The methanolic extract of the marine sponge Ircinia felix has yielded nine novel fatty acid esters, (7E, 12E, 18R, 20Z)-variabilin (5Z, 9Z)-22-methyltricosadienoate, (7E, 12E, 18R, 20Z)-variabilin (5Z, 9Z)-tetracosadienoate, (7E, 12E, 18R, 20Z)-variabilin hexadecanoate, (7E, 12E, 18R, 20Z)-variabilin 10-methylhexadecanoate, (7E, 12E, 18R, 20Z)-variabilin 15-methylhexadecanoate, (7E, 12E, 18R, 20Z)-variabilin 14-methylhexadecanoate, (7E, 12E, 18R, 20Z)-variabilin 9-octadecenoate, (7E, 12E, 18R, 20Z)-variabilin octadecanoate, and (7E, 12E, 18R, 20Z)-variabilin 2,11-dimethyloctadecanoate, along with the recently described (7E, 12E, 18R, 20Z)-variabilin 11-methyloctadecanoate. The characterization of the new fatty acids (5Z, 9Z)-22-methyltricosadienoic and 2,11-dimethyloctadecanoic acids is also described. The chemical structures were determined by extensive spectroscopic, chromatographic, and chemical analyses.

Animals↗