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Biomedical subjects

A L Stephens

Publications and source records attributed to A L Stephens.

7 recordsLinked to original sources
PubMed2001

Short-term oral estrogen replacement therapy does not augment endothelium-independent myocardial perfusion in postmenopausal women.

OBJECTIVES: The purpose of this study was to determine the effect of usual-dose estrogen replacement therapy (ERT) on myocardial perfusion and myocardial perfusion reserve (MPR) (evoked by an endothelium-independent vasodilator) in healthy postmenopausal women. Postmenopausal women have a decreased myocardial perfusion reserve compared with younger women. Estrogen infusions are known to enhance endothelium-dependent vasodilation of the epicardial coronary arteries in postmenopausal women, but whether ERT also enhances endothelium-independent myocardial perfusion and perfusion reserve is unclear. METHODS: In 24 healthy postmenopausal women who were not taking ERT, myocardial perfusion at rest, perfusion during the infusion of adenosine (a primarily endothelium-independent vasodilator), and MPR were determined by positron-emission tomography (PET) and oxygen 15-labeled water. The women were then randomly assigned in a double-blind fashion to receive either 0.625 mg of oral conjugated estrogens (Premarin) or placebo per day for 4 to 6 weeks, after which they underwent a repeat cardiac PET study. RESULTS: There was no statistical difference between those assigned to ERT and those assigned to placebo in the measurement of myocardial perfusion at rest (1.21 +/- 0.31 vs 1.16 +/- 0.18 mL/g/min, respectively) in response to adenosine (2.66 +/- 0.96 vs 3.3 +/- 0.45 mL/g/min) or MPR (2.24 +/- 0.83 vs 2.88 +/- 0.64 mL/g/min) after 4 to 6 weeks of oral ERT. There was also no difference between the groups in any of the myocardial perfusion measurements after correction for the rate-pressure product. CONCLUSIONS: Short-term oral ERT does not affect myocardial perfusion at rest in response to adenosine or MPR in healthy postmenopausal women. Thus potential beneficial effects of ERT on vasomotor function may be limited to enhancement of endothelium-dependent vasodilative mechanisms affecting conduit vessels.

Adenosine↗
PubMed1996

Spontaneous hepatic hemorrhage associated with pregnancy. Treatment by hepatic arterial interruption.

OBJECTIVE: The authors determined the effectiveness of hepatic arterial interruption in treating patients with spontaneous hepatic hemorrhage associated with pregnancy. BACKGROUND DATA: This rare syndrome frequently is seen with eclampsia/preeclampsia and is associated with high maternal mortality. The recommended treatment has been the use of local hemostatic measures. METHODS: The authors reviewed their experience managing eight patients by hepatic arterial interruption. RESULTS: Operative hepatic artery ligation was the initial method of controlling hepatic hemorrhage in three patients. One patient recovered, a hepatic sequestrum developed in one, and one patient died. Three patients survived after hepatic arterial embolization, but a sequestrum developed in one. Two patients died when hepatic arterial interruption was used after failed local hemostatic measures. CONCLUSIONS: The authors believe that hepatic arterial interruption is the preferred treatment for spontaneous hepatic hemorrhage associated with pregnancy. If the diagnosis is made at the time of cesarean section delivery, operative hepatic arterial ligation is indicated. If the diagnosis is made postpartum, percutaneous angiographic embolization should be performed.

Adolescent↗
PubMed1981

A classification system for asthmatic patients: clinical-physiological correlation.

A classification system for asthmatics based on simple, readily available clinical tools is defined and evaluated. Asthmatics so classified differed significantly in terms of their degree of dysfunction at the time of presentation. Comments regarding the relative importance and proper perspective of pulsus paradoxus and retraction of the sternocleidomastoid muscle in each classification of asthmatics is made.

Adolescent↗