Biomedical subjects

J C Dimopoulos

Publications and source records attributed to J C Dimopoulos.

3 recordsLinked to original sources

PubMed2001

Quantification of the ionising radiation effect over angiogenesis in the chick embryo and its chorioallantoic membrane by computerised analysis of angiographic images.

PURPOSE: We evaluated, in vivo, the effect of ionising radiation on the angiogenesis process in the chick embryo and its chorioallantoic membrane (CAM) using digital subtraction angiography (DSA) in conjunction with computer-assisted image analysis. Information regarding the ionising effect on endothelial cells during radiation treatment was extracted. MATERIAL AND METHODS: Two series of fertilized eggs were irradiated with a single ionising radiation dose of 10 Gy on days 9 and 13 of embryonic development. Angiography was carried out 24 h after irradiation. The angiographic images were digitized and subsequently processed. A set of specific morphological parameters was defined to allow an analytical characterization of the vascularity status. Vessels were classified into three categories according to their diameters (> or = 200 microm, 100-200 microm and 50-100 microm). The data were normalized and statistically evaluated. RESULTS: On day 10, total vascular area and total vascular length presented a 15.6+/-1.2% and 18.4+/-2.4% reduction, respectively, while vascular diameters increased 3.3+/-0.5%. The vessel area and length of the first category > or = 200 microm) increased 9.8+/-1.1% and 8.1+/-0.9%, respectively, while these morphometric parameters for each of the remaining two categories decreased 44.3+/-2.9%, 38.7+/-4.2% and 45+/-3.8%, 30.7+/-3.4%, respectively. On day 14 insignificant changes were observed. CONCLUSION: Computerised analysis of angiographic images showed that the antiangiogenic effect of irradiation during the various phases of CAM development is larger on the 10th day than that observed on day 14 and it depends on the vessel size.

Allantois↗

PubMed2001

Height velocity and skeletal maturation in elite female rhythmic gymnasts.

Rhythmic gymnasts performing under conditions of high intensity are exposed to particularly high levels of psychological stress and intense physical training, factors that can contribute to the observed delay in skeletal maturation and pubertal development, and alter optimal growth. The study was conducted in the field, during the International, European, and World Rhythmic Sports Gymnastics Championships of the years 1997-2000, and included 104 elite female rhythmic gymnasts, aged 12-23 yr. The study included height and weight measurements, estimation of body fat and skeletal maturation, and registration of parental height. Height, weight, target height, and predicted adult height were expressed as the SD score of the mean height and weight for age, according to Tanner's standards. Gymnasts were taller and thinner than average for age, with height velocity SD score for each age group above the 50th percentile for all age groups (n = 140, mean = 1.9 +/- 2.5). Interestingly, although height velocity in normal girls comes to an end by the age of 15, in our examined rhythmic gymnasts it continues up to the age of 18. There was a delay of skeletal maturation of 1.8 yr (n = 72, r = 0.730, P < 0.001), compensated by an acceleration of height velocity toward the end of puberty. The final adult height was identical to the estimated predicted height at first evaluation, and significantly higher than the genetically determined target height (n = 35, r = 0.58, P < 0.001), denoting that genetic predisposition to final height is not only achieved, but even exceeded. Using multiple regression analysis, target height was the only independent parameter that has been proven to influence positively the height velocity SD score (b = 0.233, t = 2.215, P = 0.029), denoting that genetic predisposition remains the main driving force for the observed efficient catch up growth. In conclusion, the elite rhythmic gymnasts compensate for their loss of pubertal growth spurt by a late acceleration of linear growth. Despite the delay in skeletal maturation, genetic predisposition of growth is not only preserved, but even exceeded.

Adolescent↗

PubMed1992

Linear scleroderma with severe leg deformity.

Linear scleroderma is an unusual form of localised scleroderma, mainly affecting the legs and occurring primarily in children. Sometimes the linear lesions may extend to involve the underlying muscles and bones, with severe disturbances in growth and possibly flexion deformities of the legs. In this study, two cases suffering from linear scleroderma of the legs are presented.

Adolescent↗