Diabetes modulates ethanol-induced increase in serotonin release from rat hippocampus: an in vivo microdialysis study.

We examined whether diabetes mellitus (DM) affects the acute ethanol (EtOH)-induced increase in serotonin (5-HT) release from the rat hippocampus, and compared the findings with those obtained from non-DM rats. Hippocampal 5-HT was measured by using in vivo microdialysis. Rats were rendered diabetic by an injection of streptozotocin (STZ). EtOH (0.5, 1.0, or 2.0 g/kg) was intraperitoneally administered or EtOH (25, 50, 100, or 200 mM) was given by intracerebral infusion. EtOH enhanced the extracellular 5-HT levels in both non-DM and DM rats in a dose-dependent manner, especially in non-DM rats, irrespective of administration route. Among three kinds of alcohols tested at same concentration (100 mM), methanol was the most effective in increasing extracellular 5-HT levels of non-DM rats; then, in descending order, EtOH and isopropanol. However, no such tendency was observed in DM rats. Experiments using various antagonists and agonists of 5-HT receptors showed that the functions of 5-HT(1B), 5-HT(2), 5-HT(3), and/or 5-HT(4) receptors in the hippocampus of DM rats differ from those in non-DM rats, suggesting that DM induces dysfunction of central neurotransmitter systems including 5-HT receptors. Acetaldehyde (100 mM), a major metabolite of EtOH, also significantly increased 5-HT release in both non-DM and DM rats. Based on the results that EtOH could increase the 5-HT in non-DM rats than in DM rats while acetaldehyde worked on both rats, it is more likely that alcohol dehydrogenase 1B activity was decreased in DM rats. The present study is the first, to our knowledge, to show that DM modulated the EtOH-induced 5-HT release from the hippocampus in type-1 diabetic rats.

Anesthetic management of a patient with deteriorated cardiac function following cardiopulmonary resuscitation.

A 73-year-old woman suffering from an abdominal aortic aneurysm (AAA), unstable angina, and low cardiac function (32% of ejection fraction) was scheduled for abdominal aortic replacement and coronary artery bypass grafting. However, before the scheduled operation the patient fell into cardiopulmonary arrest with ventricular fibrillation due to rupture of the AAA. Immediate cardiopulmonary resuscitation (CPR) using epinephrine and electrical defibrillation restored the spontaneous circulation. Following CPR, a continuous high-dose dopamine infusion (15 µg/kg/min) was initiated and emergent abdominal aortic replacement was performed. On arrival at the operating room, the patient showed serious hypotension, atrial fibrillation with multifocal ventricular premature contractions, and metabolic acidosis. Transesophageal echocardiography (TEE) suggested that the circulatory collapse might have resulted from diastolic dysfunction and deteriorated compliance of the left ventricular (LV) wall, possibly due to myocardial stunning induced by myocardial ischemia, and tachycardia induced by hypovolemia, both of which are influenced by high doses of catecholamine. We accordingly transfused adequate amounts of blood products and gradually decreased the infusion rate of dopamine to 4 µg/kg/min, while carefully monitoring blood pressure, central venous pressure, and TEE. By the end of surgery hemodynamic parameters had recovered to near normal levels. In post-resuscitated and hypovolemic patients, caution should be taken when administering high levels of exogenous catecholamines, which can induce myocardial stunning and circulatory collapse.

Peripheral vascular coil for peripheral MR angiography: phantom-based comparison with body coil by SNR, CNR, and visual evaluation.

AIM: To evaluate the image quality of MR angiography (MRA) with a peripheral vascular coil. MATERIALS AND METHODS: A peripheral vascular coil, a technical coil used in MRA of the pelvis and lower extremities, has 12 individual coil elements arranged in six pairs. We evaluated the performance of a peripheral vascular coil for image quality, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and visual evaluation by comparing it to a body coil using a phantom. RESULTS: SNR with the peripheral vascular coil was 1.5-2.2 times higher than that with the body coil in vertical distance, and 1.6-1.8 times higher in horizontal distance. CNR with the peripheral vascular coil was 2.1-3.8 times higher than that with the body coil. Visual evaluation with the peripheral vascular coil was 1.1-1.2 times higher than with the body coil in spin echo sequences, and 1.2-1.9 times higher in 3D fast spoiled GRASS (3D-FSPGR) sequences. CONCLUSION: The peripheral vascular coil for peripheral MRA is robust and accurate in evaluating peripheral vascular diseases.