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Biomedical subjects

S Gips

Publications and source records attributed to S Gips.

32 records · Page 2Linked to original sources

Predicting late restenosis after coronary angioplasty by very early (12 to 24 h) thallium-201 scintigraphy: implications with regard to mechanisms of late coronary restenosis.

To examine whether late coronary restenosis may be predicted by abnormalities of myocardial perfusion in the early hours after successful percutaneous transluminal coronary angioplasty and to study in greater detail the mechanisms involved in the development of late coronary restenosis after angioplasty, a prospective study was undertaken in 90 consecutive patients. Thallium-201 scintigrams were recorded at rest and during the stress of atrial pacing, 12 to 24 h after angioplasty, and the results were related to the findings at angiography in 70 patients undergoing late cardiac catheterization. A reversible thallium-201 perfusion defect was found in 39 (38%) of 104 myocardial regions supplied by the dilated coronary vessel and identified a subset of patients at high risk of late (6 to 12 months) angiographic restenosis (sensitivity 77%, specificity 67%). In contrast, late coronary restenosis developed in only 7 (11%) of 65 vessels and in 5 (14%) of 37 patients with a nonischemic thallium-201 scintigram on day 1 (p less than 0.005). Multivariate logistic regression analysis of 14 possible preangioplasty and periangioplasty clinical and angiographic variables selected reversible perfusion defect on the thallium-201 scintigram on day 1 (p = 0.016) and immediate postangioplasty residual coronary narrowing (p = 0.004) as significant independent predictors of late restenosis, with younger patient age as an additional less powerful predictor (p less than 0.05). The findings have important implications regarding the pathogenesis of late coronary restenosis in patients undergoing successful angioplasty and they imply that in the majority of these patients pathophysiologic events in the early minutes and hours after angioplasty may determine the development of late restenosis.

Adult↗

Effects of prostacyclin on ovulation and microvasculature of the in vitro perfused rabbit ovary.

Prostacyclin (prostaglandin I2) methyl ester at 0.1, 1, or 10 micrograms/ml was added to the perfusate of one rabbit ovary every 2 hours for the first 10 hours of perfusion. The contralateral ovary was perfused with medium alone. Prostacyclin methyl ester at 1 and 10 micrograms/ml induced ovulation in the absence of gonadotropin, with ovulatory efficiencies of 26.7% +/- 3.8% and 46.5% +/- 5.0%, respectively. Most ovulated ova (77.4%) did not progress beyond the germinal vesicle stage, and there was no significant degeneration of ovulated ova or follicular oocytes. Examination of the follicular microvasculature 5 hours after exposure to prostacyclin revealed marked vessel dilatation and filling defects at the apex. By 7 hours after prostacyclin exposure, the intrafollicular space contained extravasated resin, reflecting increased vascular permeability. The vascular changes paralleled those previously observed in gonadotropin-induced ovulation. These results indicate that prostacyclin acting locally alters the vascular integrity of the follicle wall and facilitates follicle rupture.

Animals↗

Osteomyelitis and soft-tissue infection: differential diagnosis with 24 hour/4 hour ratio of Tc-99m MDP uptake.

The lesion-to-nonlesion 24 hour/4 hour ratio of technetium-99m methylene diphosphonate (MDP) uptake was used to distinguish osteomyelitis from increased bone uptake caused by adjacent soft-tissue infection. In a prospective study, this ratio was measured in 38 patients with 41 sites of increased uptake that were suspected to be osteomyelitis. The mean ratio was 1.18 +/- 0.18 in patients with proved osteomyelitis, which was significantly higher (P less than .001) than that in patients with increased uptake resulting from soft-tissue infection (0.98 +/- 0.05). On the basis of a receiver operating characteristic curve, a ratio of 1.06 was selected as the cutoff for differentiating osteomyelitis from soft-tissue infection. This method resulted in a sensitivity of 82%, a specificity of 92%, and an accuracy of 85%, and it appears to be more reliable than three- and four-phase scintigraphy, which are subjective and nonquantitative techniques.

Adolescent↗