Changes in Behavior and Diel Melatonin Secretion Toward Estivation in Western Sand Lance, Ammodytes japonicus (Uranoscopiformes, Ammodytidae).

Western sand lance, Ammodytes japonicus, is known to have an estivation period, in which they cease feeding and stay in the sand from early summer to late autumn, followed by gonadal maturation. During the feeding period prior to estivation, they swim in daytime and spend the night in the sand. Before they start swimming, they show a typical behavior of head-exposing from the sand, which is likely to be related to foraging and predation avoidance. Our previous study revealed that melatonin regulates such diel behavior of this species. To elucidate the mechanisms of behavioral regulation throughout the life cycle of this sand lance, the present study examined the changes in behavior and melatonin secretion toward the estivation period. Both head-exposing and swimming behaviors were frequently observed at the transition period toward estivation. On the other hand, occurrence of these behaviors was suppressed just before entering estivation. Subsequently, it was found that plasma melatonin concentration was about three times higher at night than in daytime in the non-estivation period, while it was retained at high levels throughout the day in the estivation period. These results indicate that diurnal swimming behavior of sand lance from the feeding to estivation periods is associated with the daily cycle of melatonin secretion.

Circadian Rhythm and Endocrinological Control on the Swimming and Sand Burrowing Behaviors of Japanese Sand Lances Ammodytes spp. (Uranoscopiformes, Ammodytidae).

In diurnal and nocturnal organisms, daily activity is regulated by the perception of environmental stimuli and circadian rhythms, which enable organisms to maintain their essential behaviors. The Japanese sand lances genus Ammodytes are coastal marine fish that exhibit unique nocturnal sand burrowing behavior. To elucidate the extrinsic and intrinsic regulation of this behavior and its endocrinological basis, we conducted a series of rearing experiments under various light conditions and hormone administrations. Under a light-dark photoperiod, the fish showed three types of behavior: sand buried, head-exposed from sand, and swimming/feeding. During the transition from dark to light periods, the fish first showed head exposure, followed by swimming and foraging, and buried themselves in the sand immediately after shifting to the dark period. Under constant light conditions, fish exhibited swimming behavior during the period corresponding to the acclimated light period. In addition, swimming did not occur under constant dark conditions but head exposure was observed at the time of the dark-light transition during acclimation. These observations indicate that the essential behavior of sand lances is regulated by both light and circadian rhythms. Subsequently, a melatonin-containing diet promoted the onset of burrowing in 10 to 120 min in a dose-dependent manner at 0.3-128 µg/g-diet, suggesting the direct behavioral regulation by this hormone. These findings suggest that the behavior of sand lances is strictly regulated by an intrinsic mechanism and that melatonin is a regulatory endocrine factor that induces burrowing behavior.

[Cesarean section in a morbidly obese parturient with borderline personality disorder under combined spinal and epidural anesthesia].

A 21-year-old morbidly obese parturient with a body mass index of 45.5 kg x m(-2) underwent an emergent cesarean section for obstructed labor under combined spinal and epidural anesthesia. At age 15, she was diagnosed as borderline personality disorder. In spite of the drug therapy, her mental status was unstable. During anesthesia and surgery, her psychiatrist attended beside her to ease her anxiety and mental stress. An experienced anesthesiologist encouraged her and maintained her in the sitting position during epidural catheterization and spinal puncture. The distance between the skin and the epidural space was about 6.5 cm at the L3-4 interspace via midline approach. An epidural catheter was inserted 5 cm cephalad. Subsequently, the L4-5 subarachnoid space was accessed at a depth of about 7.0 cm. A 3 ml bolus of 0.5% hyperbaric bupivacaine was given. The anesthetic level was T4 at the start of the operation. Throughout the surgery, sufficient analgesia was obtained and any complication such as severe hypotension or respiratory depression did not develop and her postoperative course was uneventful.

Feasibility and safety of granulocyte colony-stimulating factor treatment in patients with acute myocardial infarction.

BACKGROUND: This study examined feasibility and safety of granulocyte colony-stimulating factor (G-CSF) treatment for patients with acute myocardial infarction (AMI). METHODS: Forty patients with AMI related with the left anterior descending coronary artery, who underwent successful percutaneous coronary intervention (PCI), were randomized into G-CSF group (n=18) or Control group (n=22). G-CSF treatment was started within 24 h after PCI. 99mTc-tetrofosmin single-photon emission computed tomography (SPECT) was performed at 4 days and 6 months after AMI. SPECT data was analyzed for LV end-diastolic volume (LVEDV), LV end-systolic volume (LVESV), LV ejection fraction (LVEF) and myocardial perfusion. RESULTS: LVEF at 6 months was significantly better than that at 4 days in G-CSF group (p=0.013), but not changed in Control group (p=0.245). Although no significant difference was observed for LVEDV between the two groups, LVESV tended to be decreased only in G-CSF group. In G-CSF group, defect score (DS) was significantly decreased from 4 days to 6 months after AMI. Restenosis rate at 6 months after AMI was not significantly different between the two groups. CONCLUSIONS: G-CSF treatment for patients with AMI was effective and did not have any clinical and angiographic adverse effects.

Comparison between nicorandil and magnesium as an adjunct cardioprotective agent to percutaneous coronary intervention in acute anterior myocardial infarction.

BACKGROUND: It has been reported that both nicorandil and magnesium have a cardioprotective effect in experimental ischemia - reperfusion models. In the present study, the cardioprotective effects of nicorandil and magnesium as an adjunct to reperfusion therapy in patients with acute myocardial infarction (AMI) were compared. METHODS AND RESULTS: Forty consecutive patients with AMI caused by occlusion of anterior descending coronary artery were randomized into 3 groups: (1) Group N: nicorandil was given as 4 mg iv and 4 mg ic before reperfusion, followed by continuous infusion at 4 mg/h for 24 h; (2) Group M: magnesium was administered at 10 mmol iv before reperfusion, followed by continuous infusion at 0.4 mmol/h for 24 h; and (3) Group C: neither nicorandil nor magnesium was given. Left ventriculography was performed immediately after reperfusion and 3 months later. There was no significant change in regional wall motion (RWM) in either Group C or M, whereas that of group N improved significantly. The change in RWM in Group N was significantly greater than in Group C (Group N: 0.92+/-0.92, Group M: 0.44+/-0.80, Group C: -0.01+/-0.65, p<0.05). CONCLUSIONS: The early administration of nicorandil as an adjunct to reperfusion is useful for cardioprotection in AMI, but magnesium is not.