Case report: Successful thromboprophylaxis with enoxaparin in a pregnant woman with internal jugular vein agenesis.

Internal jugular agenesis is a vascular malformation that is often associated with a history of recurrent headache. Due to the resulting abnormalities in intracranial venous drainage, it may be complicated by neurological dysfunction, such as intracranial hypertension, intracranial micro-thromboses, and neurodegenerative diseases such as multiple sclerosis. The simultaneous presence of jugular vein agenesis and thrombosis is possible in cases of acute illness, hormonal treatment, pregnancy, hypomobility, or venous drainage abnormalities (VDA) (e.g., May-Thurner syndrome). In particular, the literature still lacks data on thromboprophylaxis in pregnant women with jugular vein agenesis. Here, we report a positive experience with prophylaxis using enoxaparin during pregnancy in a patient with internal jugular agenesis.

Acute pressor and hormonal effects of beta-endorphin at high doses in healthy and hypertensive subjects: role of opioid receptor agonism.

CONTEXT: The opioid system is involved in blood pressure regulation in both normal humans and patients with essential hypertension. OBJECTIVE: The objective of the study was to investigate the effects of a high-dose infusion of beta-endorphin, an opioid peptide, on blood pressure and on the hormonal profile in healthy subjects and in hypertensive patients and the mediation played by opioid receptor agonism. DESIGN, SETTING, AND PARTICIPANTS: According to a randomized double-blind design, 11 healthy subjects (controls) and 12 hypertensive inpatients (mean age, 38.9 and 40.4 yr, respectively) received 1-h iv infusion of beta-endorphin (250 mug/h) and, on another occasion, the same infusion protocol preceded by the opioid antagonist naloxone (8 mg). MAIN OUTCOME MEASURES: Hemodynamic and hormonal measurements were performed at established times during the infusion protocols. RESULTS: At baseline, circulating beta-endorphin, norepinephrine, and endothelin-1 in hypertensive patients were significantly (P < 0.05) higher than in controls. In controls, beta-endorphin reduced blood pressure (P < 0.01) and circulating norepinephrine (P < 0.02) and increased plasma atrial natriuretic factor (P < 0.003) and GH (P < 0.0001). In hypertensive patients, beta-endorphin decreased systemic vascular resistance (P < 0.0001), blood pressure (P < 0.0001), and plasma norepinephrine (P < 0.0001) and endothelin-1 (P < 0.0001) and raised circulating atrial natriuretic factor (P < 0.0001), GH (P < 0.0001), and IGF-I (P < 0.0001). These hemodynamic and hormonal responses to beta-endorphin in hypertensive patients were significantly (P < 0.0001) greater than in controls but were annulled in all individuals when naloxone preceded beta-endorphin infusion. CONCLUSIONS: High doses of beta-endorphin induce hypotensive and beneficial hormonal effects in humans, which are enhanced in essential hypertension and are mediated by opioid receptors.