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J Tracy

Publications and source records attributed to J Tracy.

25 records · Page 2Linked to original sources
PubMed1990

Risk of late stroke and survival following carotid endarterectomy procedures for symptomatic patients.

The long-term outcome following carotid endarterectomy for neurological symptoms was analyzed using a retrospective life-table approach in 212 patients who had undergone 243 endarterectomy procedures. The postoperative follow-up period averaged 38.9 +/- 2.1 months (mean +/- standard error of the mean). The endpoints of stroke and death were evaluated in these patients. Patient groups with the preoperative symptoms of amaurosis fugax, transient ischemic attack, and prior recovered stroke were similar in terms of life-table outcome over the follow-up period. Sixty-two percent of symptomatic patients were alive and free of stroke at 5 years. The late risk of stroke (after 30 days postoperatively) averaged 1.7% per year based on a linear approximation to the hazard at each life-table interval (1.3% per year for ipsilateral stroke). The trend of late stroke risk was clearly downward, however, and could be fitted more accurately by an exponential decay function with a half-life of 33 months. Thus, the risk of stroke following carotid endarterectomy for neurological symptoms was highest in the perioperative period, slowly declined with time, and occurred predominantly ipsilateral to the procedure. The definition of a prospective medical control group remains crucial for a critical analysis of treatment modalities following the onset of premonitory neurological symptoms. In the absence of an adequate control group for this series, the calculated perioperative and postoperative stroke risk from this study was compared to data obtained from the literature on stroke risk in medically treated symptomatic patients. This uncontrolled comparison of treatment modalities suggests the combined perioperative and postoperative stroke risk associated with carotid endarterectomy to be modestly improved over medical treatment alone.

Carotid Artery Diseases↗
PubMed1978

The anti-reproductive pharmacology of LH-RH and agonistic analogues.

LH-RH and three particular ("super") analogues were evaluated for agonistic (ovulation-induction and short-term uterotrophic properties) and postcoital contraceptive activity in rodents. Additionally, LH-RH and/or a representative analogue (D-Ala6-des Gly10-Pro9-LH-RH ethylamide) were tested for postcoital contraceptive/vaginal smear/return to fertility effects, precoital contraceptive activity, and effects on puberty in the immature female. All compounds induced ovulation and uterotrophic effects and terminated pregnancy when administered either pre- or post-implantation. LH-RH and the representative analogue, while terminating pregnancy postcoitally, produced an associated break in the characteristic leucocytic vaginal smear of pregnancy to one of cornification by day 12; at this time mating and insemination were reestablished and all rats carried to normal term. Precoitally, LH-RH administered to nembutalized (but not to unblocked) rats produced a 50% reduction in the pregnancy rate and a 38% decrease in the number of viable pups delivered. In immature rats, the representative analogue delayed puberty (i.e. vaginal canalization) and retarded the growth of the ovaries, uteri, and anterior pituitary gland. The collective data strongly support the concept that LH-RH and agonistic derivatives, in spite of their putative pro-fertility classification, are characteristically antifertility by nature. Since the latter effect appears to be the paradoxically dominant one, it is suggested that LH-RH agonism is synonymous with contraception. Furthermore, such peptides may represent a new potential approach to fertility control.

Animals↗