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Biomedical subjects

W R Teodoro

Publications and source records attributed to W R Teodoro.

7 recordsLinked to original sources
PubMed2003

Livaditis' circular myotomy does not decrease anastomotic leak rates and induces deleterious changes in anastomotic healing.

Considering that Livaditis' myotomy is still accepted as a good method for lengthening the esophagus to allow primary repair of long-gap esophageal atresia, the aim of this experimental study was to verify if this procedure decreases the incidence of leaks in anastomoses performed under severe tension. In addition, it was verified whether the myotomy promotes any morphological or biochemical change in the healing esophageal anastomosis. Sixty small dogs were submitted to a cervicotomy and resection of an esophageal segment (8.0 - 10.0 cm) resulting in an anastomosis under severe tension. The animals were divided into two groups (control group: only anastomosis; experimental group: anastomosis plus circular myotomy in the proximal esophageal segment). The animals were sacrificed on the 14th postoperative day, submitted to autopsy, and were evaluated as to the presence of leaks. Twelve scars of each group were collected for histological, histomorphometric (evaluation of scar thickness), electrophoretic and immunoblotting studies of collagen (total collagen and types of collagen determinations). Leak rates were the same in both groups. Histologic examination showed that the scar at the anastomosis was formed by fibrous tissue, without mucosa or muscular tissue. In the myotomy animals, a decreased number of newly formed small vessels was noted in comparison to control animals, and morphometric analysis showed that in the myotomy animals the anastomotic scar was thinner than in the control animals. Biochemical analysis of scars demonstrated that myotomy promoted a decrease in the soluble collagen content in comparison with the control animals and no alteration in the content of insoluble collagen. The electrophoretic separation of the types of collagen and characterization by immunoblotting demonstrated the presence of collagen types I, III, and V, and the quantification by densitometry of the bands showed a reduction in collagen type V (present in the blood vessels) in the myotomy animals in comparison to controls. This result is in accordance with the histological observation of a decrease in newly formed blood vessels. Circular myotomy does not decrease the possibility of anastomotic leaks, in addition to promoting deleterious changes in anastomotic healing.

Anastomosis, Surgical↗
PubMed2003

Increase of interstitial collagen in the mouse endometrium during decidualization.

Decidualization in the mouse consists of an extensive remodeling of the endometrial extracellular matrix, resulting in a reduction of the extracellular spaces, an increase in the diameter of collagen fibrils, and changes in the relative ratio of different types of glycosaminoglycans. To assess the dynamic changes of the endometrial extracellular matrix during decidualization, collagen was analyzed biochemically and immunochemically in the endometrium of nulliparous and day 5 to day 8 pregnant mice. The amount of collagen per gram dry weight was higher in the endometrium of implantation sites than in interimplantation sites. Collagen types I, III, and V were the main components of the endometrium of nulliparous and pregnant animals. The amount of collagen type V was higher in the endometrium of pregnant animals than in nulliparous ones. A relative unusual homotrimeric form of collagen type V, probably formed by [alpha1(V)](3), was detected in pregnant endometrium by gel eletrophoresis and immunoblotting.

Animals↗
PubMed2002

Changes in collagen matrix composition in human posterior tibial tendon dysfunction.

OBJECTIVE: To investigate whether tendon degeneration in posterior tibial tendon dysfunction syndrome is associated with changes in extracellular matrix collagen composition. METHODS: Specimens from grossly abnormal tendon regions from 9 patients with posterior tibial tendon dysfunction syndrome were prepared for routine histology. Collagens I, III and V were typed by immunoblotting and quantified by densitometry after SDS-PAGE. Proline and hydroxyproline residues were determined by liquid chromatography. Four other samples from grossly normal homologous tendon regions and one surgical specimen from a healthy patient undergoing arthrodesis of the ankle after an accident were included as control. RESULTS: In the grossly abnormal surgical posterior tibial tendon specimens we observed three types of histopathologic conditions present to varying degrees: increased mucin content, fibroblast hypercellularity and neovascularization. Analysis of degenerate tendons demonstrated a 79.3% increase in total proline and a 32.4% increase in 4-hydroxyproline. In addition, damaged tissue contained a higher proportion of collagen type III (mean increase: 53.6%) associated with a concomitant increase in type V collagen (mean increase: 26.4%). These alterations were accompanied by a reduction in type I collagen (mean decrease: 41.4%). CONCLUSIONS: In posterior tibial tendon dysfunction syndrome, the degenerative process results from marked changes in both structural organization and molecular composition of matrix collagens. The higher proportion of type V and type IlI collagens in degenerated tendons is likely to contribute to a decrease in the mechanical resistance of the tissue.

Aged↗
PubMed1992

Very high collagen increase in placentae of smoking mothers.

In 55 placentae, collected at term from clinically normal pregnancies, hydroxyproline was assayed. Thirty were from mothers who smoke and 25 from nonsmokers. In placentae of smokers, hydroxyproline concentration was 42.77 +/- 8.77 micrograms/mg of tissue and in these of nonsmokers 22.52 +/- 7.46 micrograms/mg. Such high a difference discloses a large increment in placental collagen production in smokers, which may account for some of the noxious effects of tobacco on pregnancy.

Evaluation Studies as Topic↗
PubMed1989

Reduction of hydroxyproline content in the vessels of the human umbilical cord in premature rupture.

The hydroxyproline content of the amnion and the umbilical vessels obtained from cases in which the fetal membranes were instrumentally or prematurely ruptured was assayed. Hydroxyproline concentration (in micrograms/mg) in the latter group was 23.76, 16.79 and 17.86 in the amnion, artery and vein, whereas in the former the corresponding values were 42.20, 26.61 and 32.48. These results show that, in addition to a decrease in the amnion, hydroxyproline is lowered also in the umbilical vessels, suggesting that the reduction in the collagen in the fetal membranes is probably a particular manifestation of a general metabolic deficiency.

Amnion↗
PubMedDate not supplied

Short communication: placental collagen and premature rupture of fetal membranes.

Collagen content of 43 placentae from clinically normal females who went into labour spontaneously was determined by assaying hydroxyproline. In 23 cases the membranes ruptured before or at the beginning of labour, and in 20 cases the rupture was intrumentally provoked during the expulsive period. In the group with prematurely ruptured membranes, hydroxyproline concentration was 11.52 +/- 1.83 micrograms/mg lyophilized tissue, whereas in the other group concentration was 20.29 +/- 4.32 micrograms/mg tissue. These data disclose a much lower collagen placental content in the group with premature rupturing of the membranes.

Collagen↗