Search

Objective Data on the long-term outcomes of carbon-ion radiotherapy for non-squamous cell carcinomas are rare. Gunma University has been utilizing carbon-ion radiotherapy as a treatment for head and neck cancer since 2010. This study aimed to evaluate the long-term efficacy and safety of carbon-ion radiotherapy for the head and neck. Methods We prospectively evaluated 35 patients with non-squamous cell carcinoma who underwent carbon-ion radiotherapy at Gunma University Heavy Ion Medical Center between 2010 and 2014. The 5-year local control, overall survival, and progression-free survival rates were evaluated. Results The median age was 59 years (range, 31–77 years), and the median follow-up time was 65 months (range, 6.1–98.8 months). Overall, 32 and 3 patients received 64.0 Gy (relative biological effectiveness) and 57.6 Gy (relative biological effectiveness) in 16 fractions, respectively. Adenoid cystic carcinoma was the most dominant histopathological type (n = 21 patients, 60 %). The 5-year local control, progression-free survival, and overall survival rates were 74.5 %, 53.2 %, and 81.3 %, respectively. Nine patients had local recurrence, and six patients died. Adverse events included acute grade 3 radiation mucositis (Common Terminology Criteria for Adverse Events version 4.0) in 8 patients; this was improved immediately with conservative therapy. Late grade 4 adverse events were observed, including two cases of visual loss and one case of brain necrosis. No grade 5 adverse events were observed. Conclusion Carbon-ion radiotherapy achieves excellent local control and overall survival rates in non-squamous cell carcinoma patients with expected adverse events.

Bone and soft-tissue sarcomas of the head and neck have very poor prognoses. This prospective study aimed to investigate the efficacy and safety of carbon-ion radiotherapy (C-ion RT) for bone and soft-tissue sarcoma of the head and neck.The present study was a prospective clinical study that included 10 consecutive patients diagnosed with bone and soft-tissue sarcoma of the head and neck who were treated with C-ion RT between 2012 and 2018 at our institution. C-Ion RT consisted of 70.4 Gy (relative biological effectiveness) in 16 fractions.The 3-year local control, overall survival, and progression-free survival rates for patients overall were 72.9%, 77.8%, and 36%, respectively.The present study demonstrated the efficacy of C-ion RT for bone and soft-tissue sarcoma of the head and neck; adverse events were within the expected range.

A 50-year-old woman with a long history of nasopharyngeal cancer (T2N2M0, squamous cell carcinoma) underwent chemoradiotherapy and surgery. In the past, to prevent tumor recurrence or metastasis, she underwent concurrent chemoradiotherapy or neck dissection. However, during a follow-up 10 years after the surgery, intense F-18 fluorodeoxyglucose uptake was detected in the oral area (SUVmax 6.0). A biopsy of the area with F-18 fluorodeoxyglucose uptake revealed pathological inflammation. Radiography showed the presence of a wisdom tooth, located at the F-18 fluorodeoxyglucose accumulation site, and pericoronitis of this tooth was detected. Our findings indicate the importance of considering the effect of inflammatory conditions, such as periodontal disease, in using F-18 fluorodeoxyglucose positron emission tomography/computed tomography during follow-up after head and neck cancer treatment.

This study aimed to evaluate the efficacy of carbon‐ion radiotherapy in combination with chemotherapy using dacarbazine, nimustine, and vincristine (DAV therapy) in mucosal melanoma. Twenty‐one patients with clinically localized mucosal melanoma of the head and neck were enrolled. The primary endpoint was 3‐year overall survival (OS). Secondary endpoints included local control, progression‐free survival (PFS), and adverse event occurrence. Carbon‐ion radiotherapy with a dose of 57.6‐64.0 Gy (relative biological effectiveness) in 16 fractions was delivered concurrently with DAV therapy, and 2 cycles of adjuvant DAV therapy were administered every 6 weeks. The median follow‐up periods were 15.5 months for all patients, and 31.2 months for 12 surviving patients. All patients had locally advanced T4a or T4b disease in the rhino‐sinus area. In 16 patients (76.2%), 3 cycles of planned DAV therapy were completed. The 3‐year OS and PFS rates were 49.2% and 37.0% respectively. The 3‐year local control rate was 92.3%. Eleven patients (52%) developed distant metastasis, which was the most frequent pattern of the first failure. Commonly presenting acute grade 2‐3 toxicities associated with radiotherapy and chemotherapy were mucositis (11 patients [53%]) and leukopenia (9 patients [43%]), which improved with conservative therapy. None of the patients developed grade 3 or greater late toxicities. Carbon‐ion radiotherapy in combination with DAV therapy led to excellent local control for advanced mucosal melanoma within acceptable toxicities. The efficacy of additional DAV therapy in improving survival was weaker than expected as distant metastases still occurred frequently. Trial registration no. UMIN000007939., It is the first prospective trial to evaluate the clinical outcomes of carbon‐ion radiotherapy combined with chemotherapy.

Anti-transcription intermediary factor 1γ (anti-TIF1γ) antibody (Ab) is significantly associated with internal malignancies in adult patients with dermatomyositis (DM). Although pathogenesis of cancer-associated DM is unknown, TIF1γ overexpression in tumors has been considered to be critical for the development of DM. The objective of this study was to investigate clinical characteristics of patients with anti-TIF1γ Ab-positive DM and elucidate risk factors that are potentially associated with internal malignancy. In addition, we compared the expression of TIF1γ in tumor tissues of patients with anti-TIF1γ Ab-positive DM, anti-TIF1γ Ab-negative DM and without DM in order to investigate the pathogenesis of cancer-associated DM. We analyzed 77 Japanese patients with DM, and found 19 patients to be positive for anti-TIF1γ Ab. Patients with anti-TIF1γ Ab-positive DM were older and presented heliotrope rash and flagellate erythema more frequently than patients without anti-TIF1γ Ab (P < 0.05). Interstitial lung disease (ILD) and rapidly progressive ILD, as well as palmar violaceous erythema, were less frequent in patients with anti-TIF1γ Ab than in patients without. Furthermore, internal malignancy and dysphagia were significantly more frequent in the anti-TIF1γ Ab-positive group (P < 0.01). Male sex and dysphagia were significantly associated with internal malignancy in patients with anti-TIF1γ Ab-positive DM (P < 0.01 and

To evaluate the efficacy and safety of carbon-ion radiotherapy for non-squamous cell carcinoma of the head and neck, 35 patients were enrolled in this prospective study. The primary end-point was the 3-year local control rate, and the secondary end-points included the 3-year overall survival rate and adverse events. Acute and late adverse events were evaluated according to the Common Terminology Criteria for Adverse Events, version 4.0. The median follow-up time for all patients was 39 months. Thirty-two and three patients received 64.0 Gy (relative biological effectiveness) and 57.6 Gy (relative biological effectiveness) in 16 fractions, respectively. Adenoid cystic carcinoma was dominant (60%). Four patients had local recurrence and five patients died. The 3-year local control and overall survival rates were 93% and 88%, respectively. Acute grade 2-3 radiation mucositis (65%) and dermatitis (31%) was common, which improved immediately with conservative therapy. Late mucositis of grade 2, grade 3, and grade 4 were observed in 11, one, and no patients, respectively. There were no adverse events of grade 5. Carbon-ion radiotherapy achieved excellent local control and overall survival rates for non-squamous cell carcinoma. However, the late mucosal adverse events were not rare, and meticulous treatment planning is required. Trial registration no. UMIN000007886.

A total of 33 patients with advanced head and neck cancer (AHNC) treated with sequential chemoradiotherapy (SCRT) were retrospectively evaluated at Gunma University Hospital between 2009 and 2011. The regimen of SCRT was docetaxel, cisplatin, and fluorouracil (TPF)-based induction chemotherapy (ICT), accompanied by docetaxel and cisplatin-based concurrent chemoradiotherapy (CCRT), and oral administration of TS-1 after that. The response rate was 61%, the 3-year overall survival rate was 42%, the non-tumor-bearing survival rate was 27%, and the tumor-bearing survival rate was 15%. Fourteen of 33 patients were tumor-free, and their 3-year overall survival rate was surprisingly 86%. On the other hand, 3-year overall survival rate in the remaining 19 patients was significantly low. To select good response cases for ICT was important. In such cases, TPF should be applied repeatedly, which achieved a 61% response rate even in AHNC. A long-term TS-1 oral medication suppressed cancer regrowth and contributed to long-term survival.

Conclusion: A high GRP78/BiP expression was proved to be a significant marker for predicting poor outcome after surgery. GRP78/BiP may be a promising molecular target for treatment of ACC. Background: The glucose-regulated protein GRP78/BiP plays a crucial role in the endoplasmic reticulum (ER) stress. The level of GRP78 is highly elevated in various human cancers, but the clinicopathological significance of GRP78/BiP remains controversial in patients with adenoid cystic carcinoma (ACC). Methods: A total of 26 ACC patients were analyzed, and tumor specimens were stained by immunohistochemistry for GRP78/BiP, PERK, Ki-67, and microvessel density (MVD) determined by CD34. Results: GRP78/BiP and PERK were highly expressed in 58% (15/26) and 35% (9/26), respectively. The high expression of GRP78/BiP was significantly associated with PERK, cell proliferation and angiogenesis.

We assessed herein the post-operative lymph node metastasis in head and neck cancer, using the One-step nucleotide amplification (OSNA) method targeting matrix metalloproteinase 7 (MMP-7). Compared with the pathological test, the molecular biological test revealed more lymph node metastasis, resulting in poor prognosis. Six cases, of which the number of lymph node metastasis was the same between pathological and molecular biological test, survived. On the other hand, three of four cases, in which number of lymph node metastasis in the molecular biological test were larger than the pathological test, died from metastasis. We concluded that the pathological test underestimated metastasis, and OSNA with MMP-7 was useful for the prediction of post-operative lymph node metastasis.

To assess the efficacy of concurrent chemoradiotherapy (CCRT) with daily low-dose cisplatin (CDDP) plus weekly docetaxel (DTX) for patients with T2N0 glottic cancer. Between January 2004 and December 2013, 62 treatment-naive patients with histologically proven T2N0 glottic cancer were treated with concurrent chemoradiotherapy. Radiation therapy (RT; 2 Gy daily fractions up to a total dose of 66 Gy) was administered in combination with daily low-dose CDDP (6 mg/m2, five times a week), plus weekly DTX (10 mg/m2) for up to 4 weeks from the commencement of RT. Median duration of follow-up was 70 months. The actuarial 3-year and 5-year overall survival rates were 95% and 93%. The 3-year and 5-year cause-specific survival rates were both 100%. The actuarial 3-year and 5-year local control rates were 94% and 94%, respectively. Hematologic toxicity (neutoropenia of severity ≥ Grade 3) was observed in 8% of the patients, and non-hematologic toxicity (radiation mucositis of severity ≥ Grade 3) developed in one patient (2%). Radiation dermatitis of severity ≥ Grade 3 and laryngeal necrosis developed in one patient. CCRT with weekly DTX and low-dose CDDP appears to be a practical and safe modality and is expected to improve local control. UMIN000025046 . Registered 1 October 2015, retrospectively registered.

Background Both L-type amino acid transporter 1 (LAT1) and CD98 are strongly expressed in primary human cancer and play essential roles in tumor growth. We studied the clinicopathological significance of LAT1 and CD98 expression in hypopharyngeal squamous cell carcinoma (SCC). Methods A total of 70 patients with stage III/IV disease were retrospectively reviewed. Immunohistochemical staining of tumor sections was used to examine LAT1, CD98, Ki-67, CD34, and p53. Results High LAT1 and CD98 expression were noted in 60.0% and 47.1%, respectively (p = .174). A statistically significant correlation was recognized between LAT1 and CD98 expression and both expressions were closely associated with tumor cell proliferation. Although LAT1 expression was not significantly associated with poor survival, multivariate analysis revealed high CD98 expression to be an independent prognostic factor for predicting a poor outcome. Conclusion CD98 is a promising prognostic marker for predicting outcomes after surgical treatment in patients with advanced hypopharyngeal SCC. © 2014 Wiley Periodicals, Inc. Head Neck 37: 1569–1574, 2015

Background: Amino-acid transporters are necessary for the tumour cell growth and survival, and have a crucial role in the development and invasiveness of cancer cells. But, it remains unclear about the prognostic significance of L-type amino-acid transporter 1 (LAT1), system ASC amino-acid transporter-2 (ASCT2), and xCT expression in patients with tongue cancer. We conducted the clinicopathological study to investigate the protein expression of these amino-acid transporters in tongue cancer. Methods: Eighty-five patients with surgically resected tongue cancer were evaluated. Tumour sections were stained by immunohistochemistry for LAT1, ASCT2, xCT, 4F2hc/CD98hc (4F2hc), Ki-67, and microvessel density (MVD) determined by CD34, and p53. Results: L-type amino-acid transporter 1 and 4F2hc were highly expressed in 61% (52 out of 85) and 45% (38 out of 47), respectively. ASC amino-acid transporter-2 and xCT were positively expressed in 59% (50 out of 85) and 21% (18 out of 85), respectively. The expression of both LAT1 and ASCT2 was significantly associated with disease staging, lymph-node metastasis, lymphatic permeation, 4F2hc expression and cell proliferation (Ki-67). xCT expression indicated a significant association with advanced stage and tumour factor. By univariate analysis, disease staging, lymphatic permeation, vascular invasion, LAT1, ASCT2, 4F2hc, and Ki-67 had a significant relationship with overall survival. Multivariate analysis confirmed that LAT1 was an independent prognostic factor for predicting poor prognosis. Conclusions: L-type amino-acid transporter 1 and ASCT2 can serve as a significant prognostic factor for predicting worse outcome after surgical treatment and may have an important role in the development and aggressiveness of tongue cancer.

Objectives/Hypothesis: Recurrent pneumonia due to intractable aspiration is a life-threatening disease. A tracheal flap method for children without previous tracheostomy has been previously reported. This study reports that improvements of this method and its three subtypes are widely applicable to patients with various conditions. Study Design: Surgical technique study. Methods: The tracheal flap method does not involve transection of the trachea but achieves laryngotracheal separation using the tracheal, mucoperichondrial, and sternohyoid muscle, along with anterior cervical skin flaps. This method can be divided into three subtypes as follows: A-type, utilizing the tracheal flap (for patients without previous tracheostomy); B-type, utilizing the mucoperichondrial and sternohyoid muscle flaps (for patients lacking an anterior tracheal wall); and C-type, utilizing the esophageal flap (for patients with severe hypersalivation). In all three subtypes, the anterior cervical skin flap is employed. Results: The tracheal flap method was performed in 30 patients (24 children and six adults) at risk of developing intractable aspiration pneumonia. In all 30 cases, aspiration pneumonia was prevented without severe complications. No fistula formation was observed. Conclusions: All three subtypes (A-, B-, and C-type) of the tracheal flap method are effective in preventing the recurrence of aspiration pneumonia. This method is applicable to diverse patient backgrounds regardless of age or previous tracheostomy. It is less invasive than Lindeman procedure. Furthermore, this method is acceptable to patients' families and improves the QOL of both patients and caregivers. Laryngoscope, 2012

Fragile X syndrome, the most common form of inherited mental retardation and leading genetic cause of autism, is caused by transcriptional silencing of theFmr1gene. The fragile X mental retardation protein (FMRP), the gene product ofFmr1, is an RNA binding protein that negatively regulates translation in neurons. TheFmr1knock-out mouse, a model of fragile X syndrome, exhibits cognitive deficits and exaggerated metabotropic glutamate receptor (mGluR)-dependent long-term depression at CA1 synapses. However, the molecular mechanisms that link loss of function of FMRP to aberrant synaptic plasticity remain unclear. The mammalian target of rapamycin (mTOR) signaling cascade controls initiation of cap-dependent translation and is under control of mGluRs. Here we show that mTOR phosphorylation and activity are elevated in hippocampus of juvenileFmr1knock-out mice by four functional readouts: (1) association of mTOR with regulatory associated protein of mTOR; (2) mTOR kinase activity; (3) phosphorylation of mTOR downstream targets S6 kinase and 4E-binding protein; and (4) formation of eukaryotic initiation factor complex 4F, a critical first step in cap-dependent translation. Consistent with this, mGluR long-term depression at CA1 synapses of FMRP-deficient mice is exaggerated and rapamycin insensitive. We further show that the p110 subunit of the upstream kinase phosphatidylinositol 3-kinase (PI3K) and its upstream activator PI3K enhancer PIKE, predicted targets of FMRP, are upregulated in knock-out mice. Elevated mTOR signaling may provide a functional link between overactivation of group I mGluRs and aberrant synaptic plasticity in the fragile X mouse, mechanisms relevant to impaired cognition in fragile X syndrome.

NMDARs (N-methyl-D-aspartate receptors) are critical for synaptic function throughout the CNS (central nervous system). NMDAR-mediated Ca2+ influx is implicated in neuronal differentiation, neuronal migration, synaptogenesis, structural remodelling, long-lasting forms of synaptic plasticity and higher cognitive functions. NMDAR-mediated Ca2+ signalling in dendritic spines is not static, but can be remodelled in a cell- and synapse-specific manner by NMDAR subunit composition, protein kinases and neuronal activity during development and in response to sensory experience. Recent evidence indicates that Ca2+ permeability of neuronal NMDARs, NMDAR-mediated Ca2+ signalling in spines and induction of NMDAR-dependent LTP (long-term potentiation) at hippocampal Schaffer collateral–CA1 synapses are under control of the cAMP/PKA (protein kinase A) signalling cascade. Thus, by enhancing Ca2+ influx through NMDARs in spines, PKA can regulate the induction of LTP. An emerging concept is that activity-dependent regulation of NMDAR-mediated Ca2+ signalling by PKA and by extracellular signals that modulate cAMP or protein phosphatases at synaptic sites provides a dynamic and potentially powerful mechanism for bi-directional regulation of synaptic efficacy and remodelling.

Glutamate transporters play a critical role in the maintenance of low extracellular concentrations of glutamate, which prevents the overactivation of post-synaptic glutamate receptors. Four distinct glutamate transporters, GLAST/EAAT1, GLT-1/EAAT2, EAAC1/EAAT3 and EAAT4, are distributed in the molecular layer of the cerebellum, especially near glutamatergic synapses in Purkinje cells (PCs). This review summarizes the current knowledge about the differential roles of these transporters at excitatory synapses of PCs. Data come predominantly from electrophysiological experiments in mutant mice that are deficient in each of these transporter genes. GLAST expressed in Bergmann glia contributes to the clearing of the majority of glutamate that floods out of the synaptic cleft immediately after transmitter release from the climbing fibre (CF) and parallel fibre (PF) terminals. It is indispensable to maintain a one-to-one relationship in synaptic transmission at the CF synapses by preventing transcellular glutamate spillover. GLT-1 plays a similar but minor role in the uptake of glutamate as GLAST. Although the loss of neither GLAST nor GLT-1 affects cerebellar morphology, the deletion of both GLAST and GLT-1 genes causes the death of the mutant animal and hinders the folium formation of the cerebellum. EAAT4 removes the low concentrations of glutamate that escape from uptake by glial transporters, preventing the transmitter from spilling over into neighbouring synapses. It also regulates the activation of metabotropic glutamate receptor 1 (mGluR1) in perisynaptic regions at PF synapses, which in turn affects mGluR1-mediated events including slow EPSCs and long-term depression. No change in synaptic function is detected in mice that are deficient in EAAC1.

The cAMP/protein kinase A (PKA) signaling cascade is crucial for synaptic plasticity in a wide variety of species. PKA regulates Ca 2+ permeation through NMDA receptors (NMDARs) and induction of NMDAR-dependent synaptic plasticity at the Schaffer collateral to CA1 pyramidal cell synapse. Whereas the role of PKA in induction of NMDAR-dependent LTP at CA1 synapses is established, the identity of PKA isoforms involved in this phenomenon is less clear. Here we report that protein synthesis-independent NMDAR-dependent LTP at the Schaffer collateral–CA1 synapse in the hippocampus is deficient, but NMDAR-dependent LTD is normal, in young (postnatal day 10 (P10)–P14) mice lacking PKA RIIβ, the PKA regulatory protein that links PKA to NMDARs at synaptic sites. In contrast, in young adult (P21–P28) mice lacking PKA RIIβ, LTP is normal and LTD is abolished. These findings indicate that distinct PKA isoforms may subserve distinct forms of synaptic plasticity and are consistent with a developmental switch in the signaling cascades required for LTP induction.

Around excitatory synapses in cerebellar Purkinje cells (PCs), GLAST and EAAT4 are expressed as predominant glial and neuronal glutamate transporters, respectively. EAAC1, another subtype of neuronal glutamate transporter, is also expressed in PCs. EAAT4 is co-localized with metabotropic glutamate receptors (mGluRs) at perisynaptic sites in excitatory synapses in PCs, and this neuronal transporter was reported to be involved in the regulation of mGluR activation induced by the stimulation of parallel fibers (PFs). However, it remains to be elucidated whether only EAAT4 is specifically involved in mGluR activation among the glutamate transporters expressed near excitatory synapses in PCs. Here we examined mGluR-mediated excitatory postsynaptic currents (mGluR-EPSCs) evoked by PF stimulation in cerebellar slices of mice deficient in EAAT4, EAAC1, or GLAST. PF-evoked mGluR-EPSCs showed larger amplitude and faster rising kinetics in EAAT4-deficient mice than in the wild-type mice. In contrast, there was no significant difference in either the amplitude or the rising kinetics of mGluR-EPSCs in GLAST- or EAAC1-deficient mice compared to wild-type mice. We conclude that EAAT4 is most closely involved in mGluR activation in PCs among the glutamate transporters.

Unipolar brush cells (UBCs) are excitatory interneurons in the granular layer of the cerebellar cortex, which are predominantly distributed in the vestibulo-cerebellar region. The unique firing properties and synaptic connections of UBCs may underlie lobular heterogeneity of excitability in the granular layer and the susceptibility to ischemia-induced excitotoxicity. In this study, we investigated the effects of oxygen-glucose deprivation (OGD) on the firing properties of UBCs and granule cells and spontaneous excitatory postsynaptic currents (sEPSCs) of Purkinje cells using whole-cell recordings. Short-term OGD induced increases in spontaneous firing of UBCs by causing membrane depolarization via the activation of NMDA receptors. UBC firing indirectly affected Purkinje cells by altering parallel fiber inputs of a subset granule cells, resulting in a marked increase in sEPSCs in Purkinje cells in vestibulo-cerebellar lobules IX-X, but not in lobules IV-VI, which have fewer UBCs. Similarly, the frequency and amplitude of sEPSCs in Purkinje cells were significantly greater in lobules IX-X than in IV-VI, even in control conditions. These results reveal that UBCs play key roles in regulating local excitability in the granular layer, resulting in lobular heterogeneity in the susceptibility to ischemic insult in the cerebellum.

Glial glutamate transporters, GLAST and GLT-1, are co-localized in processes of Bergmann glia (BG) wrapping excitatory synapses on Purkinje cells (PCs). Although GLAST is expressed six-fold more abundantly than GLT-1, no change is detected in the kinetics of climbing fiber (CF)-mediated excitatory postsynaptic currents (CF-EPSCs) in PCs in GLAST(/) mice compared to the wild-type mice (WT). Here we aimed to clarify the mechanism(s) underlying this unexpected finding using a selective GLT-1 blocker, dihydrokainate (DHK), and a novel antagonist of glial glutamate transporter, (2S,3S)-3-[3-(4-methoxybenzoylamino)benzyloxy]aspartate (PMB-TBOA). In the presence of cyclothiazide (CTZ), which attenuates the desensitization of AMPA receptors, DHK prolonged the decay time constant (tw) of CF-EPSCs in WT, indicating that GLT-1 plays a partial role in the removal of glutamate. The application of 100 nM PMB-TBOA, which inhibited CF-mediated transporter currents in BG by 80%, caused no change in tw in WT in the absence of CTZ, whereas it prolonged tw in the presence of CTZ. This prolonged value of tw was similar to that in GLAST(/) mice in the presence of CTZ. These results indicate that glial glutamate transporters can apparently retain the fast decay kinetics of CF-EPSCs if a small proportion (20%) of functional transporters is preserved. # 2005 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.

Global ischemia in humans or induced experimentally in animals causes selective and delayed neuronal death in pyramidal neurons of the hippocampal CA1. The ovarian hormone estradiol administered before or immediately after insult affords histological protection in experimental models of focal and global ischemia and ameliorates the cognitive deficits associated with ischemic cell death. However, the impact of estradiol on the functional integrity of Schaffer collateral to CA1 (Sch-CA1) pyramidal cell synapses following global ischemia is not clear. Here we show that long term estradiol treatment initiated 14 days prior to global ischemia in ovariectomized female rats acts via the IGF-1 receptor to protect the functional integrity of CA1 neurons. Global ischemia impairs basal synaptic transmission, assessed by the input/output relation at Sch-CA1 synapses, and NMDA receptor (NMDAR)-dependent long term potentiation (LTP), assessed at 3 days after surgery. Presynaptic function, assessed by fiber volley and paired pulse facilitation, is unchanged. To our knowledge, our results are the first to demonstrate that estradiol at near physiological concentrations enhances basal excitatory synaptic transmission and ameliorates deficits in LTP at synapses onto CA1 neurons in a clinically-relevant model of global ischemia. Estradiol-induced rescue of LTP requires the IGF-1 receptor, but not the classical estrogen receptors (ER)-α or β. These findings support a model whereby estradiol acts via the IGF-1 receptor to maintain the functional integrity of hippocampal CA1 synapses in the face of global ischemia. This article is part of a Special Issue entitled SI: Brain and Memory.

Glutamate transporters are essential for terminating excitatory neurotransmission. Two distinct glutamate transporters, glutamate–aspartate transporter (GLAST) and excitatory amino acid transporter 4 (EAAT4), are expressed most abundantly in the molecular layer of the cerebellar cortex. GLAST is expressed in Bergmann glial processes surrounding excitatory synapses on Purkinje cell dendritic spines, whereas EAAT4 is concentrated on the extrasynaptic regions of Purkinje cell spine membranes. To clarify the functional significance of the coexistence of these transporters, we analyzed the kinetics of EPSCs in Purkinje cells of mice lacking either GLAST or EAAT4. There was no difference in the amplitude or the kinetics of the rising and initial decay phase of EPSCs evoked by stimulations of climbing fibers and parallel fibers between wild-type and EAAT4-deficient mice. However, long-lasting tail currents of the EPSCs appeared age dependently in most of Purkinje cells in EAAT4-deficient mice. These tail currents were never seen in mice lacking GLAST. In the GLAST-deficient mice, however, the application of cyclothiazide that reduces desensitization of AMPA receptors increased the peak amplitude of the EPSC and prolonged its decay more markedly than in both wild-type and EAAT4-deficient mice. The results indicate that these transporters play differential roles in the removal of synaptically released glutamate. GLAST contributes mainly to uptake of glutamate that floods out of the synaptic cleft at early times after transmitter release. In contrast, the main role of EAAT4 is to remove low concentrations of glutamate that escape from the uptake by glial transporters at late times and thus prevents the transmitter from spilling over to neighboring synapses.

Glutamate transporters rapidly take up synaptically released glutamate and maintain the glutamate concentration in the synaptic cleft at a low level. (2S, 3S)-3-[3-[4-(trifluoromethyl)benzoylamino]benzyloxy]aspartate (TFB-TBOA) is a novel glutamate transporter blocker that potently suppresses the activity of glial transporters. TFB-TBOA inhibited synaptically activated transporter currents (STCs) in astrocytes in the stratum radiatum in rat hippocampal slices in a dose-dependent manner with an IC50 of 13 nM, and reduced them to approximately 10% of the control at 100 nM. We investigated the effects of TFB-TBOA on glutamatergic synaptic transmission and cell excitability in CA1 pyramidal cells. TFB-TBOA (100 nM) prolonged the decay of N-methyl-D-aspartic acid receptor (NMDAR)-mediated excitatory postsynaptic currents (EPSCs), whereas it prolonged that of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR)-mediated EPSCs only when the desensitization of AMPARs was reduced by cyclothiazide (CTZ). Furthermore, long-term application of TFB-TBOA induced spontaneous epileptiform discharges with a continuous depolarization shift of membrane potential. These epileptiform activities were mainly attributed to NMDAR activation. Even after pharmacological block of NMDARs, however, TFB-TBOA induced similar changes by activating AMPARs in the presence of CTZ. Thus, the continuous uptake of synaptically released glutamate by glial transporters is indispensable for protecting hippocampal neurons from glutamate receptor-mediated hyperexcitabilities.

Several subtypes of glutamate transporters are abundantly expressed near the excitatory synapses on cerebellar Purkinje cells. We investigated the roles of the glutamate transporters in shaping the excitatory postsynaptic currents (EPSCs) and regulating the levels of extracellular glutamate in the mouse cerebellum using a potent blocker of glutamate transporters, dl-threo-beta-benzyloxyaspartate (dl-TBOA). This drug markedly prolonged AMPA receptor-mediated EPSCs in Purkinje cells evoked by stimulating both parallel fibres and climbing fibres. The decay phase of the prolonged EPSCs was fitted by double exponentials, of which the slower component was preferentially inhibited by a low-affinity competitive antagonist of AMPA receptors, gamma-d-glutamyl-glycine, indicating that the slow component induced by dl-TBOA was the AMPA receptor-mediated current activated by lower concentrations of glutamate than those contributing to the peak of the EPSC. This result suggests that dl-TBOA prolongs the stay of synaptically released glutamate in the synaptic cleft and also induces glutamate spillover to extrasynaptic targets as well as neighbouring synapses. Furthermore, high concentrations of dl-TBOA in the presence of cyclothiazide generated a continuous inward current in Purkinje cells, of which the amplitude reached the peak level of the climbing-fibre EPSC. This continuous inward current was abolished by the blocker of AMPA receptors, indicating that the strong inhibition of glutamate uptake causes the rapid accumulation of glutamate in the extracellular space. These results highlight the importance of glutamate transporters in maintaining the proper glutamatergic transmission in Purkinje cell synapses.

Cholinergic projections are relatively sparse in the cerebellum compared with other parts of the brain. However, some mossy fibers in the vestibulo-cerebellum are known to be cholinergic. To clarify the functional roles of cholinergic mossy fibers in the vestibulo-cerebellum, we investigated the effects of acetylcholine (ACh) on the membrane electrical properties of both granule cells and Purkinje cells in slices of the cerebellar vermis of the rat using whole-cell patch-clamp techniques. The bath application of ACh induced a marked increase in the frequency of spontaneous EPSCs (sEPSCs) in Purkinje cells specifically in the vestibulo-cerebellum. This effect of ACh was mimicked by muscarine but not by nicotine. It was abolished by application of either tetrodotoxin or the antagonist of AMPA receptors, indicating that the ACh-induced enhancement of sEPSCs occurred indirectly via the activation of neurons sending glutamatergic projections to Purkinje cells. In ∼15% of granule cells tested in the vestibulo-cerebellum, muscarine elicited membrane depolarization accompanied by a decrease in membrane conductance and increased the neuronal excitability. The muscarine-induced depolarization of granule cells in the vestibulo-cerebellum was attributable to the inhibition of standing-outward K+currents (IKSO) most likely via the activation of muscarinic M3receptors. Taken together, these results indicate that ACh increases the firing frequency of granule cells by inhibitingIKSO, which in turn increases the frequency of sEPSCs in Purkinje cells in the rat vestibulo-cerebellum.

Glial cells express a variety of neurotransmitter receptors. Notably, Bergmann glial cells in the cerebellum have Ca 2+ -permeable α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)–type glutamate receptors (AMPARs) assembled without the GluR2 subunit. To elucidate the role of these Ca 2+ -permeable AMPARs, we converted them into Ca 2+ -impermeable receptors by adenoviral-mediated delivery of the GluR2 gene. This conversion retracted the glial processes ensheathing synapses on Purkinje cell dendritic spines and retarded the removal of synaptically released glutamate. Furthermore, it caused multiple innervation of Purkinje cells by the climbing fibers. Thus, the glial Ca 2+ -permeable AMPARs are indispensable for proper structural and functional relations between Bergmann glia and glutamatergic synapses.

Both L-type amino acid transporter 1 (LAT1) and CD98 are strongly expressed in primary human cancer and play essential roles in tumor growth. We studied the clinicopathological significance of LAT1 and CD98 expression in hypopharyngeal squamous cell carcinoma (SCC).A total of 70 patients with stage III/IV disease were retrospectively reviewed. Immunohistochemical staining of tumor sections was used to examine LAT1, CD98, Ki-67, CD34, and p53.High LAT1 and CD98 expression were noted in 60.0% and 47.1%, respectively (p = .174). A statistically significant correlation was recognized between LAT1 and CD98 expression and both expressions were closely associated with tumor cell proliferation. Although LAT1 expression was not significantly associated with poor survival, multivariate analysis revealed high CD98 expression to be an independent prognostic factor for predicting a poor outcome.CD98 is a promising prognostic marker for predicting outcomes after surgical treatment in patients with advanced hypopharyngeal SCC.

Group I metabotropic glutamate receptors (mGluR1/5) are important to synaptic circuitry formation during development and to forms of activity-dependent synaptic plasticity. Dysregulation of mGluR1/5 signaling is implicated in some disorders of neurodevelopment, including fragile X syndrome, the most common inherited form of intellectual disabilities and leading cause of autism. Site(s) in the intracellular loops of mGluR1/5 directly bind caveolin-1, an adaptor protein that associates with membrane rafts. Caveolin-1 is the main coat component of caveolae and organizes macromolecular signaling complexes with effector proteins and membrane receptors. We report that long-term depression (LTD) elicited by a single application of the group I mGluR selective agonist ( RS )-3,5-dihydroxyphenylglycine (DHPG) was markedly attenuated at Schaffer collateral-CA1 synapses of mice lacking caveolin-1 ( Cav1 −/− ), as assessed by field recording. In contrast, multiple applications of DHPG produced LTD comparable to that in WT mice. Passive membrane properties, basal glutamatergic transmission and NMDA receptor (NMDAR)-dependent LTD were unaltered. The remaining LTD was reduced by anisomycin, an inhibitor of protein synthesis, by U0126, an inhibitor of MEK1/2 kinases, and by rapamycin, an inhibitor of mammalian target of rapamycin (mTOR), suggesting mediation by the same mechanisms as in WT. mGluR1/5-dependent activation (phosphorylation) of MEK and extracellular signal-regulated kinase (ERK1/2) was altered in Cav1 −/− mice; basal phosphorylation was increased, but a single application of DHPG had no further effect, and after DHPG, phosphorylation was similar in WT and Cav1 −/− mice. Taken together, our findings suggest that caveolin-1 is required for normal coupling of mGluR1/5 to downstream signaling cascades and induction of mGluR-LTD.

18 páginas, 8 figuras, 4 figuras suplementarias., Protein kinase C (PKC) enhances NMDA receptor (NMDAR)-mediated currents and promotes NMDAR delivery to the cell surface via SNARE-dependent exocytosis. Although the mechanisms of PKC potentiation are established, the molecular target of PKC is unclear. Here we show that synaptosomal-associated protein of 25 kDa (SNAP-25), a SNARE protein, is functionally relevant to PKC-dependent NMDAR insertion, and identify serine residue-187 as the molecular target of PKC phosphorylation. Constitutively active PKC delivered via the patch pipette potentiated NMDA (but not AMPA) whole-cell currents in hippocampal neurons. Expression of RNAi targeting SNAP-25 or mutant SNAP-25(S187A) and/or acute disruption of the SNARE complex by treatment with BoNT A, BoNT B or SNAP-25 C-terminal blocking peptide abolished NMDAR potentiation. A SNAP-25 peptide and function-blocking antibody suppressed PKC potentiation of NMDA EPSCs at mossy fiber-CA3 synapses. These findings identify SNAP-25 as the target of PKC phosphorylation critical to PKC-dependent incorporation of synaptic NMDARs and document a postsynaptic action of this major SNARE protein relevant to synaptic plasticity., This work was supported by National Institutes of Health Grants NS20752 (to R.S.Z.), NS45287 (to M.V.L.B.), and BFU2006-007138 (to J.L.).

Changes in emotional state are known to alter neuronal excitability and can modify learning and memory formation. Such experience-dependent neuronal plasticity can be long-lasting and is thought to involve the regulation of gene transcription. We found that a single fear-inducing stimulus increased GluR2 (also known as Gria2) mRNA abundance and promoted synaptic incorporation of GluR2-containing AMPA receptors (AMPARs) in mouse cerebellar stellate cells. The switch in synaptic AMPAR phenotype was mediated by noradrenaline and action potential prolongation. The subsequent rise in intracellular Ca(2+) and activation of Ca(2+)-sensitive ERK/MAPK signaling triggered new GluR2 gene transcription and a switch in the synaptic AMPAR phenotype from GluR2-lacking, Ca(2+)-permeable receptors to GluR2-containing, Ca(2+)-impermeable receptors on the order of hours. The change in glutamate receptor phenotype altered synaptic efficacy in cerebellar stellate cells. Thus, a single fear-inducing stimulus can induce a long-term change in synaptic receptor phenotype and may alter the activity of an inhibitory neural network.

A glial glutamate transporter, GLAST, is expressed abundantly in Bergmann glia and plays a major role in glutamate uptake at the excitatory synapses in cerebellar Purkinje cells (PCs). It has been reported that a higher percentage of PCs in GLAST-deficient mice are multiply innervated by climbing fibers (CFs) than in the wild-type (WT) mice, and that CF-mediated EPSCs with small amplitude and slow rise time, designated as atypical slow CF-EPSCs, are observed in these mice. To clarify the mechanism(s) underlying the generation of these atypical CF-EPSCs, we used (2S,3S)-3-[3-(4-methoxybenzoylamino)benzyloxy]aspartate (PMB-TBOA), an inhibitor of glial glutamate transporters. After the application of PMB-TBOA, slow-rising CF-EPSCs were newly detected in WT mice, and their rise and decay kinetics were different from those of conventional fast-rising CF-EPSCs but similar to those of atypical CF-EPSCs in GLAST-deficient mice. Furthermore, both slow-rising CF-EPSCs in the presence of PMB-TBOA in WT mice and atypical CF-EPSCs in GLAST-deficient mice showed much greater paired-pulse depression compared with fast-rising CF-EPSCs. In addition, both of them were more markedly inhibited by gamma-d-glutamyl-glycine, a low-affinity competitive antagonist of AMPA receptors. These results indicated that both of these types of EPSCs were mediated by a low concentration of glutamate released from neighboring CFs. Based on all of these findings, we suggest that glial transporters prevent glutamate released from a single CF from spilling over to neighboring PCs other than the synaptically connected PC, and play an essential role in the maintenance of the functional one-to-one relationship between CFs and PCs.

Objectives: Vestibular evoked myogenic potential (VEMP) has been used to test vestibulocollic reflex. However, VEMP is not stable on elderly patients because of their weak muscular strength. In this study, we tried to record VEMP on median neck extensor muscles with weak muscular contraction Study Design: We recorded VEMP from normal subjects and patients by novel and conventional methods Method: Thirty-one normal subjects and 56 patients with vertigo or hearing loss were tested in a seated or prone position without muscular tension. The different electrodes were placed on the median surface at the palpable bottom of the occipital bone Results: Our response showed a clear negative peak at 13 ms on normal subjects, with reversed polarity compared with VEMP on the sternocleidomastoid muscle. This potential is defined as VEMP caused by the proper latencies, dependency of the strength on sound stimulation, and independence of hearing ability. In the cases of acoustic neurinoma, onset latencies were prolonged or nonexistent. The responses on neck extensor muscles could not be recorded on some elderly patients. Conclusion: This new method of recording VEMP is less invasive and suitable for elderly patients.

Descending necrotizing mediastinitis is an uncommon form of mediastinitis that can rapidly progress to septacemia. To date, the optimal surgical approach has remained controversial. We report a case of descending necrotizing mediastinitis that was treated successfully through a transcervical approach with video-assisted mediastinoscopy. In our case, because the abscess was separated into small compartments, especially in the paratracheal space, the abscess was drained using video-assisted mediastinoscopy. This less-invasive approach may be an option in the treatment of descending necrotizing mediastinitis, especially when the abscess in the paratracheal space is separated into small compartments.