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Biomedical subjects

G Carlos

Publications and source records attributed to G Carlos.

4 recordsLinked to original sources

Contrasting patterns of genetic structure in two species of the coral trout Plectropomus (Serranidae) from east and west Australia: introgressive hybridisation or ancestral polymorphisms.

Inter-specific genetic relationships among regional populations of two species of grouper (Plectropomus maculatus and Plectropomus leopardus) were examined using mitochondrial and nuclear markers. mtDNA revealed contrasting regional inter-specific patterns whilst nuclear markers revealed contrasting patterns among markers, irrespective of region. In eastern Australia (EA) the species form a single mtDNA lineage, but the two species are reciprocally monophyletic in Western Australia (WA). This supports previous evidence for hybridisation between these species on the east coast. WA P. leopardus forms a sister relationship with the EA P. leopardus-maculatus clade while WA P. maculatus is more basal and sister to the P. leopardus lineages, indicating mtDNA does not suffer from incomplete lineage sorting for these species. In contrast, one of three nuclear markers (locus 7-90TG) differentiated the species into two reciprocally monophyletic clades, with no evidence of hybridisation or ancestral polymorphism. The remaining two nuclear markers (2-22 and ETS-2) did not separate these two species, while distinguishing other plectropomid species, suggesting incomplete lineage sorting at these nuclear loci. These results together with coalescence analyses suggest that P. leopardus females have hybridised historically with P. maculatus males and that P. maculatus mitochondria were displaced through introgressive hybridisation and fixation in the P. maculatus founder population on the Great Barrier Reef. The contrasting regional patterns of mtDNA structure may be attributed to Quaternary sea-level changes and shelf width differences driving different reef configurations on each coast. These reef configurations have provided opportunities for local scale interaction and reproduction among species on the narrower EA continental shelves, but not on the broader WA continental shelves.

Animals↗

Acceptability of two spermicides in five countries.

Data from a large, international, multicenter, randomized trial were analyzed to compare the acceptability of two nonoxynol-9 spermicide preparations. Women who wished to use a spermicide for contraception were randomly assigned to use either a foaming tablet (n = 383) or a nonoxynol-9 film (n = 382) for 28 weeks as their only method of contraception. Participants completed questionnaires about acceptability of the assigned product 4 weeks after admission and at discontinuation. Women in both groups had very favorable opinions of the spermicide. The proportion of women who said that they liked their assigned product very much was 50% in the tablet group and 55% in the film group. Significantly more women in the film group rated the spermicide difficult to insert and stated that the product stuck to the finger during insertion. More women in the tablet group said that the product was messy and that, at least once, it did not dissolve. In both groups, liking the product was significantly associated with consistency of use, but not with subsequent pregnancy. Participants' male partners had little influence on participants' opinions about, or use of, the spermicides. Although previous analyses showed that both spermicides are associated with high pregnancy rates, they are both highly acceptable to most women.

Adolescent↗

Monocusp valve and transannular patch reconstruction of the right ventricular outflow tract: an experimental study.

Repair of congenital right ventricular outflow tract obstruction often requires reconstruction with a transannular patch to alleviate pulmonary stenosis. Post repair pulmonary insufficiency with right ventricular dilatation and volume overload may result and lead to acute or progressive right heart failure. The use of a monocusp valve has been proposed as a means to prevent this problem. Fresh pericardium is well known to fail clinically, leading to pulmonary insufficiency limiting mid- and long-term results. In a chronic dog model (147 +/- 34 days), three valve types were evaluated: 1) polytetrafluoroethylene (PTFE; n = 9), 2) fresh pericardium (PERI; n = 6), and glutaraldehyde fixed pericardium (GLU; n = 6). Hemodynamics, angiography, and echocardiography were performed at implantation and sacrifice. Gross and microscopic pathology were evaluated. No significant differences were found among the three groups with regard to stenosis as evaluated by echocardiography, measured right ventricular wall thickness, and hemodynamic pressure gradients across the valve. By echocardiography, both PTFE (1 of 9) and GLU (0 of 6) showed less regurgitation than PERI (5 of 6) (p < 0.05). This was confirmed by angiography. PTFE showed less neo-intimal hyperplasia, less thrombus formation, and less calcification than GLU or PERI (p = NS). The PTFE monocusp developed no prohibitive gradients, no early pathologic deterioration, and maintained competence compared with the GLU and PERI groups. Although continued investigation of long-term durability and competence of the PTFE monocusp valve is warranted, both PTFE and GLU values seem to demonstrate less regurgitation than the PERI monocusp valve in an adult dog model of right ventricular outflow tract reconstruction.

Animals↗