Biomedical subjects

D Comas

Publications and source records attributed to D Comas.

43 records · Page 3Linked to original sources

PubMed1996

Treatment of extravasation of both doxorubicin and vincristine administration in a Y-site infusion.

OBJECTIVE: To describe a patient treated with vincristine, doxorubicin, and dexamethasone who experienced extravasation of both doxorubicin and vincristine during a Y-site infusion. CASE SUMMARY: A 74-year-old white woman was diagnosed with multiple myeloma IgA kappa in stage IIA. One year after a complete remission she relapsed. Her treatment included daily doxorubicin 16 mg in 500 mL of dextrose 5% and vincristine 0.4 mg in 500 mL of dextrose 5% administered in a Y-site continuous infusion into a peripheral vein of her left forearm. Extravasation occurred during administration of these drugs. Immediately, chondroitinsulfatase, a mucopolysaccharidase similar to hyaluronidase, was administered subcutaneously around the extravasation area and repeated 24 hours later. Furthermore, dimethyl sulfoxide 90% v/v was applied topically on the area four times daily for 2 weeks. All inflammatory signs resolved and no necrosis developed. DISCUSSION: Ths is the first report of an extravasation of two cytotoxic drugs. Doxorubicin and vincristine have different antidotes and opposite physical treatments for their extravasation. The antidotes dimethyl sulfoxide and chondroitinsulfatase have different mechanisms of action, but both cause uptake of the cytotoxic agent from the tissue and are likely to be administered together. No warming or cooling was performed. CONCLUSIONS: Topical dimethyl sulfoxide four times daily for 14 days plus subcutaneous chondroitinsulfatase in one or two applications effectively treated an extravasation of both doxorubicin and vincristine in our patient.

Administration, Topical↗

PubMed1995

Heteroplasmy in the control region of human mitochondrial DNA.

The sequencing of a 360-nucleotide segment of the mt DNA control region in a population survey revealed the presence of one individual having heteroplasmy in positions 16,293 (A and G) and 16,311 (C and T). This case indicates that heteroplasmy in humans may not be as rare as generally believed.

Base Sequence↗

PubMed1995

Human mitochondrial DNA variation and the origin of Basques.

The hypervariable segment I of the control region of the mtDNA (positions 16024-16383) was PCR-amplified from mouth scrape and hairs and sequenced in 45 unrelated individuals of pure matrilineal Basque descent. Twenty-seven different sequences were found, of which 21 are unique to the Basques. The allelic partition observed, together with resampling experiments, suggested that much more variation remained to be discovered. The mean pairwise difference in number of nucleotides between individuals was 3-15, a very low value. Moreover, the number of steps for the most parsimonious tree is very low compared to the number of different sequences. Both findings suggest that the Basque population was founded by a few lineages that diverged in a short time span. The number of nucleotide differences between individuals was shown not to be influenced by the distance between their birthplaces, thus validating the sampling strategy used a posteriori. The pairwise difference distribution agreed well with the three-parameter model proposed by Rogers & Harpending (1992). The parameter estimates found for the Basques implied that a demographic expansion (or perhaps two, given the bimodal shape of the distribution) took place sometime between 14500 and 42000 BP which is in agreement with archaeological data. Our sample was compared to other populations for which D-loop sequences were available through the Nei & Miller (1990) distance. In a neighbour-joining tree, all the Caucasoid samples, including the Basques, appeared tightly clustered, whereas African samples were the most distant to the Caucasoids and also the most heterogeneous. Although classical markers, such as blood groups and protein polymorphisms, clearly separate the Basques (and the Sardinians) from other European populations, this distinctiveness was not found using D-loop sequences.

Base Sequence↗

PubMedDate not supplied

mtDNA analysis of the Galician population: a genetic edge of European variation.

Analysis of mitochondrial DNA (mtDNA) variation has become a useful tool for human population studies. We analysed the first hypervariable region of mitochondrial DNA control region (position 16024-16383) in 92 unrelated individuals from Galicia (Spain), a relatively isolated European population at the westernmost continental edge. Fifty different sequences defined by 56 variable positions were found. The frequency of the reference sequence reaches in Galicians its maximum value in Europe. Moreover, several genetic indexes confirm the low variability of our sample in comparison to data from 11 European and Middle Eastern populations. A parsimony tree of the sequences reveals a high simplicity of the tree, with few and small well defined clusters. These results place Galicians on the genetic edge of the European variation, bringing together all the traits of a cul-de-sac population with a striking similarity to the Basque population. The present results are fully compatible with a population expansion model in Europe during the Upper Paleolithic age. The genetic evidence revealed by the analysis of mtDNA shows the Galician population at the edge of a demographic expansion towards Europe from the Middle East.

Base Sequence↗

PubMedDate not supplied

Analysis of mtDNA HVRII in several human populations using an immobilised SSO probe hybridisation assay.

Several populations were typed for the hypervariable region II (HVRII) of the mitochondrial DNA (mtDNA) control region using immobilised sequence-specific oligonucleotide (SSO) probes. A total of 16 SSO probes was used to type 1081 individuals from eight different ethnic groups (African Americans, Somali, US Europeans, US Hispanics, Bosnians, Finns, Saami and Japanese). Data was compared with already published sequence data by analysis of principal components, genetic distances and analysis of the molecular variance (AMOVA). The analyses performed group the samples in several clusters according to their geographical origins. Most of the variability detected is assigned to differences between individuals and only 7% is assigned to differences among groups of populations within and between geographical regions. Several features are patent in the samples studied: Somali, as a representative East African population, seem to have experienced a detectable amount of Caucasoid maternal influence; different degrees of admixture in the US samples studied are detected; Finns and Saami belong to the European genetic landscape, although Saami present an outlier position attributable to a strong maternal founder effect. The technique used is a rapid and simple method to detect human variation in the mtDNA HVRII in a large number of samples, which might be useful in forensic and population genetic studies.

Bosnia and Herzegovina↗

PubMedDate not supplied

Human mitochondrial DNA sequence variation in the Moroccan population of the Souss area.

BACKGROUND: Various populations have contributed to the present-day gene pool of Morocco, including the autochthonous Berber population, Phoenicians, Sephardic Jews, Bedouin Arabs and sub-Saharan Africans. OBJECTIVE: The primary objective of the study was to complete a genetic description of the Berber-speaking population in the Souss region of southern Morocco, based on mitochondrial DNA (mtDNA) sequence analysis. SUBJECTS AND METHODS: The first hypervariable segment of the mtDNA control region was sequenced in a sample of 50 individuals from the Souss Valley, and the results compared with the extensive body of data available on mtDNA sequence variation in Europe and sub-Saharan Africa. RESULTS: Thirty-four different sequences were found: an estimated 68% of the sequences occurred throughout Europe, West Asia and North Africa, 26% originated in sub-Saharan Africa, and 6% belonged to the North African specific haplogroup U6. The Souss Valley mtDNA sequences indicated the presence of two populations which expanded at different times: the West Eurasian sequences in the Souss sample had a smaller average number of pairwise differences than pairs of sub-Saharan sequences. CONCLUSION: Detailed knowledge of the possible geographic origin of each sequence facilitated an interpretation of both internal diversity parameters and between-population relationships. The sub-Saharan admixture in the Souss Valley matched the south-north cline of sub-Saharan influence in North Africa, also evident in the genetic distances of North African populations to Europeans and sub-Saharan Africans.

Africa South of the Sahara↗

PubMedDate not supplied

Allele frequencies for 20 microsatellites in a worldwide population survey.

20 microsatellite polymorphisms: HUMHPRT, HUMD3S1358, HUMTH01, HUMACPP, HUMVWF, HUMD16S310, HUMD4S243, HUMTPO, HUMFES/FPS, HUMF13A1, HUMDHFRP2, HUMD11S2010, HUMD13S767, HUMD9S926, HUMD2S1328, HUMD14S306, HUMD18S848, HUMD5S818, HUMD7S820 and HUMFGA were analyzed in a worldwide survey covering five continents and allele frequencies are given. There is a high heterogeneity in allele frequencies among continents. A neighbor-joining tree based on Fst distance shows a pattern of differentiation that may reflect the role of drift in the development of genetic differences among humans. The variation found between continents confirms the usefulness of tetranucleotide microsatellites in human genetic variation studies.

Alleles↗