Sevoflurane-induced pica in female rats.

We examined the effects of volatile anesthetics on pica, which can be used to assess nausea and vomiting in rats. We found that inhalation anesthesia with sevoflurane significantly induced pica in female but not male rats. Among the female rats, young rats (8 weeks old) were more susceptible to its induction than adult rats (20 weeks old) with ovariectomy or sham-surgery. Anti-emetic drugs that are used to prevent postoperative nausea and vomiting (PONV) inhibited the pica. These results suggest that sevoflurane-induced pica in young female rats has the potential to be an animal model of PONV in humans.

Induction of autophagy in malignant rhabdoid tumor cells by the histone deacetylase inhibitor FK228 through AIF translocation.

Malignant rhabdoid tumors (MRT) exhibit a very poor prognosis because of their resistance to chemotherapeutic agents and new therapies are needed for the treatment of this cancer. Here, we show that the histone deacetylase (HDAC) inhibitor FK228 (depsipeptide) has an antitumor effect on MRT cells both in vitro and in vivo. FK228 is a unique cyclic peptide and is among the most potent inhibitors of both Class I and Class II HDACs. FK228 inhibited proliferation and induced apoptosis in all MRT cell lines tested. Preincubation with the pancaspase inhibitor zVAD-fmk did not completely rescue FK228-induced cell death, although it did inhibit apoptosis. Transmission electron microscopy (TEM) showed that FK228 could stimulate MRT cells to undergo apoptosis, necrosis or autophagy. FK228 converted unconjugated microtubule-associated protein light chain 3 (LC3-I) to conjugated light chain 3 (LC3-II) and induced localization of LC3 to autophagosomes. Apoptosis inducing factor (AIF), which plays a role in caspase-independent cell death, translocated to the nucleus in response to FK228 treatment. Moreover, small interfering RNA (siRNA) targeting of AIF prevented the morphological changes associated with autophagy and redistribution of LC3 to autophagosomes. Disrupting autophagy with chloroquine treatment enhanced FK228-induced cell death. In vivo, FK228 caused a reduction in tumor size and induced autophagy in tumor tissues. Using immunoelectron microscopy, we confirmed AIF translocation into the nucleus of FK228-induced autophagic cells in vivo. Thus, FK228 is a novel candidate for an antitumor agent for MRT cells.

A new therapeutic modality involving acridine orange excitation by photon energy used during reduction surgery for rhabdomyosarcomas.

Rhabdomyosarcoma is a common malignant soft tissue that frequently involves bone and major neurovascular structures and resection of deep-seated rhabdomyosarcoma can cause severe dysfunction in the affected limbs. Based on the mouse osteosarcoma model, we developed a new surgical approach involving photodynamic surgery (PDS), photodynamic therapy (PDT) and radiodynamic therapy (RDT) using acridine orange (AO). Six rhabdomyosarcoma cases were treated using this new modality after confirming the effectiveness of AO-PDT on human rhabdomyosarcoma cell lines. All patients had almost normal limb function after surgery, with only one recurrence. Based on these results, AO-PDS, PDT and RDT can be used to preserve excellent limb function in patients with rhabdomyosarcoma involving major nerves and vessels or bones.

Effects of edaravone on N-methyl-D-aspartate (NMDA)-mediated cytochrome c release and apoptosis in neonatal rat cerebrocortical slices.

N-Methyl-D-aspartate-mediated neurotoxicity is known to involve nitric oxide production and to be augmented in an environment of reactive oxygen species. We used TUNEL staining and homogenous cytosolic immunoreactivity of cytochrome c in an acute brain slice preparation to investigate the influence of edaravone (3-methyl-1-phenyl-2-pyrazolin-5-one), a free radical scavenger, on N-methyl-D-aspartate-induced apoptosis. Cerebrocortical slices were obtained from parietal lobes of 7-day-old Sprague-Dawley rats, superfused with well-oxygenated artificial cerebrospinal fluid, and metabolically recovered. Subsequent 30-min exposures to 10 microM N-methyl-D-aspartate in treated and untreated slices were followed by 4 h of recovery superfusion with oxygenated artificial cerebrospinal fluid. Outcomes were compared for three groups of slices: "the N-methyl-D-aspartate-only group"; "the edaravone treatment group", which had 20 microM edaravone present throughout and subsequent to N-methyl-D-aspartate exposure; the "control group", in which slices were superfused only with oxygenated artificial cerebrospinal fluid. At the conclusion of recovery (t = 4 h), the percentage of TUNEL-positive cells in the edaravone treatment group (7.0+/-3.3%) was significantly reduced from the percentage for the N-methyl-D-aspartate-only group (21.9+/-4.1%), and insignificantly greater than the percentage for the control group (3.4+/-2.1%). Percentages of cytochrome c positive cells at t = 1 h were significantly increased (p < 0.01) in the N-methyl-d-aspartate-only group (30.6+/-1.9%) compared to percentages for both the control group (11.4+/-2.6%) and the edaravone treatment group (15.2+/-2.1%). Edaravone's reduction in TUNEL staining and cytochrome c release provides evidence of reactive oxygen species mechanisms and antioxidant benefits in cytochrome c-mediated apoptosis during N-methyl-D-aspartate excitotoxicity.

Changes of neural activity correlate with the severity of cortical ischemia in patients with unilateral major cerebral artery occlusion.

BACKGROUND AND PURPOSE: In major cerebral arterial steno-occlusive diseases, there can be remarkably decreased hemodynamic reserve without marked neurological impairments. In such settings, it is not known whether the neural activity is well maintained or disturbed according to the severity of cerebral ischemia. The present study was therefore undertaken to examine the neural activity under mild cerebral ischemia resulting from major cerebral arterial occlusion. METHODS: Seven patients with minor neurological impairment as well as either unilateral internal carotid artery or middle cerebral artery occlusion were studied. The severity of the cortical ischemia was assessed by measuring regional cerebral blood flow (rCBF) with positron emission tomography. The change in neural activity in the ischemic brain was then evaluated by means of somatosensory evoked magnetic field with magnetoencephalography. RESULTS: The rCBF in the primary sensory area and the strength of the initial component of somatosensory evoked magnetic field (N20 m) were significantly reduced (P<0.01) and the second component (P30 m) was significantly augmented (P<0.05) in the lesioned cerebral hemisphere as compared with the nonlesioned hemisphere. The asymmetry indexes for N20 m were positively correlated (r=0.78) and those for P30 m were inversely correlated (r=-0.92) with asymmetry indexes for rCBF. CONCLUSIONS: In patients with either unilateral internal carotid artery or middle cerebral artery occlusion and minor neural impairments, there was a reduction of afferent signal and an augmentation of the secondary response of the neurons in the primary sensory area. This showed correlation with the severity of cortical ischemia.

Implications of MYCN amplification in patients with stage 4 neuroblastoma who undergo intensive chemotherapy.

BACKGROUND/PURPOSE: This study aims to clarify the implications of MYCN amplification in patients with high-risk neuroblastomas treated with 2 different regimens of induction chemotherapy established by the Japan Study Group for Advanced Neuroblastoma. METHODS: Between 1985 and 2003 in Japan, 392 patients with stage 4 neuroblastomas who were older than 12 months were treated with 2 regimens of induction chemotherapy (the combination of cyclophosphamide [CTX], cisplatin [CDDP], pirarubicin, and vincristine or etoposide). Regimen 91A3 or 98A3 (A3) (CTX 2400 mg/m2, CDDP 125 mg/m2) was a higher dose combination of CTX and CDDP than regimen 85A1 or 91A1 (A1) (CTX 1200 mg/m2, CDDP 90 mg/m2). The 392 cases were classified into 3 groups (A, 1 copy; B, 2-9 copies; C, more than 10 copies) based on the MYCN amplification status by a Southern blot analysis. RESULTS: The 5-year overall survival rate (5-YS) was 41.1% for all 392 cases. Regarding the MYCN amplification status, the 5-YS was 46.6% for A group (n = 227), 22.7% for B group (n = 26), and 36.0% for C group (n = 139). A fluorescence in situ hybridization analysis showed the presence of the cells with more than 10 copies in cases with 2 to 9 copies based on the Southern blot findings. Of the 227 patients in a group, the 5-YS was 46.7% for the 70 cases treated by A3 and 47.0% for 154 cases treated by A1 (nonsignificant). The 5-YS of the 210 patients with stem cell transplantation (SCT) (51.%) was significantly better than that of the 127 patients without SCT (41.1%) (P < .05). CONCLUSIONS: Regarding the MYCN amplification status, the tumor aggressiveness might thus be different between 2 and 9 copies and a single copy of MYCN. In neuroblastomas with 2 and 9 copies of MYCN based on a Southern blot analysis, the MYCN amplification status should be analyzed using the fluorescence in situ hybridization method. Induction chemotherapy followed by SCT according to the Japan Study Group for Advanced Neuroblastoma protocol improved the outcome of neuroblastomas with MYCN amplification; however, obtaining a further improvement in the long-term survival of stage 4 neuroblastomas may therefore require the development of an even more effective treatment modality.