Ontogenetic metamorphosis and extreme sexual dimorphism in lumpsuckers: Eumicrotremus asperrimus, Cyclopteropsis bergi and Cyclopteropsis lindbergi, may be synonymous

Cyclopterids were hatched from egg batches that were laid in two empty buccinid snail shells collected from a depth of 340 m in the Sea of Japan. Larvae were reared to identify species and to describe the morphological changes associated with metamorphosis. The fin rays of all fins were mostly complete and the pelvic fins were modified to form suckers, or adhesive discs, at the time of hatching. Juveniles immediately attached themselves to the bottom and there was no planktonic stage. The body surface was smooth with no spines or bony tubercles. At 4 months after hatching, the fine spines present on the head and trunk of juveniles transformed into bony tubercles. At 7 months after hatching, fishes became sexually dimorphic including the position and development patterns of bony tubercles. Importantly, these sexually dimorphic changes in morphology corresponded closely with descriptions of different species. Specifically, females could be classified as Eumicrotremus asperrimus, and young and fully developed males as Cyclopteropsis bergi and Cyclopteropsis lindbergi, respectively. These observations resolved a previously ambiguous hypothesis regarding the taxonomy of these cyclopterid taxa. Cyclopteropsis bergi and C. lindbergi may be synonyms of E. asperrimus.

Plant homeodomain finger protein 11 promotes class switch recombination to IgE in murine activated B cells

BACKGROUND

Polymorphisms of the Plant homeodomain finger protein 11 (PHF11) are strongly associated with high serum IgE levels and clinical severity of atopic patients. However, the precise mechanism has not been fully elucidated. We investigated the role of Phf11 in class switch recombination (CSR) to IgE by activated B cells.

METHODS

We generated Phf11 transgenic (Lckd-Phf11-Tg) mice that express the exogenous murine Phf11 in lymphocytes under the control of distal Lck promoter. We examined IL-4-induced CSR to IgE in activated Lckd-Phf11-Tg B cells in vitro. We analyzed production of ovalbumin (OVA)-specific IgE and nose-scratching symptoms in Lckd-Phf11-Tg mice using an OVA-induced allergic rhinitis model.

RESULTS

The exogenous Phf11 promoted CSR to IgG1 and IgE in activated B cells with an increase in germ line transcript (GLT) γ1 and GLT ε expression. The exogenous Phf11 augmented transcriptional activity of the GLT γ1 and GLT ε promoters through permissive histone modifications and binding of NF-κB and STAT6. Furthermore, the exogenous Phf11 bound to the GLT ε promoter with increased binding of NF-κB. Silencing of the endogenous Phf11 reduced the frequency of CSR to IgE and GLT ε expression, but not to IgG1 or GLT γ1 expression, in activated B cells. In an allergic rhinitis model, Lckd-Phf11-Tg mice showed a significant increase in the production of OVA-specific IgE and the frequency of nose scratching.

CONCLUSION

Phf11 accelerates CSR to IgE in activated B cells by increasing the transcriptional activity of GLT ε promoter and contributes to the exacerbation of allergic responses. These findings provide a novel therapeutic target for allergic diseases.

Behavioral consequences of unilateral inferior colliculus lesions in the rat

This study was carried out to determine the behavioral sensitivity to sound of rats with unilateral lesions of inferior colliculus (IC) located ipsilateral or contralateral to the projection pathway from one ear. Absolute thresholds for the detection of a broad-band noise burst were compared for rats with a profound conductive hearing loss in one ear and a lesion placed either ipsilateral or contralateral to the normally functioning ear. The rats were trained to make withdrawal responses to avoid a shock when they detected the presence of a noise burst. Sound pressure level was systematically lowered to obtain psychophysical curves from which absolute thresholds could be determined. Complete lesions of the contralateral IC resulted in substantial elevations in absolute threshold relative to normal whereas equivalent lesions of the ipsilateral IC produced relatively little elevation. In neither case did unilateral destruction of the IC produce a total inability to respond to sound. Contralateral IC lesions that included the dorsal nucleus of the lateral lemniscus (DNLL) produced a significantly greater elevation in behavioral thresholds than complete lesions limited to the IC. The results indicate a predominance of the contralateral over the ipsilateral pathway to IC for maintaining normal thresholds. They also indicate that other pathways that bypass the IC are likely involved in detecting the presence of a sound.

Effects of bosentan on nondigital ulcers in patients with systemic sclerosis

BACKGROUND

Bosentan is an oral dual endothelin receptor antagonist, which has been shown to be efficacious for preventing new digital ulcers in patients with systemic sclerosis (SSc) in two high-quality randomized controlled trials. However, its efficacy for nondigital ulcers in SSc remains unknown.

OBJECTIVES

To evaluate the efficacy of bosentan on nondigital ulcers in patients with SSc.

METHODS

Bosentan was administered to five patients with SSc with pulmonary arterial hypertension, who also had nondigital ulcers refractory to conventional treatments. The efficacy of bosentan on nondigital ulcers and its association with clinical features of ulcers were analysed.

RESULTS

The nondigital ulcers refractory to conventional treatments were significantly improved by the administration of bosentan in cases surrounded with severe cyanosis. In contrast, nondigital ulcers without cyanosis were still refractory to bosentan therapy.

CONCLUSIONS

Bosentan may be efficacious for accelerating the healing of nondigital ulcers with severe cyanosis, suggesting that nondigital ulcers caused by severely impaired peripheral circulation are highly responsive to this treatment.

Efficacy and safety of garenoxacin in the treatment of upper respiratory tract infections

OBJECTIVE

To determine the efficacy and safety of garenoxacin, a new generation of quinolone antimicrobial agent, in the treatment of adult upper respiratory tract infections.

METHODS

A total of 113 subjects were enrolled in this study. Garenoxacin (400mg/day) was administered to patients with pharyngolaryngitis, tonsillitis, and otitis media for 5-7 days and to those with sinusitis for 7-10 days. Clinical symptoms and findings were examined and quantitatively evaluated using a scoring system.

RESULTS

We found 80 to 100% improvement rate in symptoms and findings for each infection. In addition, we found significant improvement in subjective evaluations from patient questionnaires even in the early stage of the treatment. X-ray examination for acute sinusitis demonstrated that the clinical efficacy was 84% (27/32) and 76% (19/25) patients were already improved within seven days. Among the detected 84 bacteria, 75 (89%) were identified as the major pathogenic bacteria of respiratory tract infections such as Streptococcus pneumoniae (27 strains) and Haemophillus influenzae (14 strains). Garenoxacin administration completely eradicated bacteria in 53 out of 54 cases (98%). There were 8 adverse events (8.3%) including 3 diarrhea cases (3.1%).

CONCLUSION

These results suggest that garenoxacin is a highly effective and safe antimicrobial agent in the treatment of community-acquired upper respiratory infections. Additionally, garenoxacin did not induce the growth of resistant bacteria because of its strong antimicrobial activity.

Chondroblastoma of the temporal bone

Chondroblastomas are highly destructive tumors that are derived from immature cartilage cells. The occurrence of this tumor in the temporal bone or skull base is uncommon. Approximately 70 cases have previously been reported, several of which have involved the temporomandibular joint (TMJ). We report here the case of a 67-year-old woman who presented with right-sided mixed hearing loss, a right external auditory canal mass, ear fullness, otalgia, blood-stained otorrhea, and pain around the TMJ, associated with difficulty in opening the mouth. CT and MRI revealed a mass involving the TMJ, infratemporal fossa, and pterygopalatine fossa. The patient underwent tumor resection via an infratemporal fossa approach type B. Gross total tumor removal was achieved, with no facial nerve paralysis or other complications observed after surgery. No recurrence or residual tumors were observed on CT and MRI, even after 7.5 years of follow-up. We conclude that temporal bone chondroblastomas are extremely rare and aggressive, but the outcome after appropriate surgical treatment is favorable. From the review, it may be particularly important to deal with tumors that involve the TMJ, which could affect the long-term outcomes, as well as tumor recurrence.

Bcl6 in pulmonary epithelium coordinately controls the expression of the CC-type chemokine genes and attenuates allergic airway inflammation

BACKGROUND

There is synteny in the CC-type chemokine gene clusters between humans (CCL2/MCP-1, CCL7MCP-3, CCL11/eotaxin, CCL8/MCP-2, CCL13/MCP-4, and CCL1/I-309) and mice (CCL2, CCL7, CCL11, CCL12/MCP-5, CCL8, and CCL1).

OBJECTIVE

As many putative Bcl6/STAT-binding sequences are observed in the clusters, we examined the roles of a transcriptional repressor Bcl6 and the regional histone modification in the expression of these chemokine genes in pulmonary epithelium.

METHODS

We generated transgenic (Tg) mice carrying the Bcl6 or the dominant-negative (DN)-Bcl6 gene under the control of the surfactant protein C (SPC) promoter that induces the exogenous gene expression in the distal lung epithelium. For in vitro studies, A549, alveolar type II-like epithelial cell line transfected with the SPC-DN-Bcl6 gene were stimulated with IL-4+TNF-α, and Bcl6 or STAT6 binding to and histone modification of the cluster in the transfectants were analysed by chromatin immunoprecipitation assays. Tg mice sensitized with ovalbumin (OVA) were challenged with OVA inhalation. The amounts of mRNAs in each sample were analysed by quantitative RT-PCR.

RESULTS

The amount of Bcl6 bound to the cluster decreased in A549 cells stimulated with IL-4 and TNF-α, whereas STAT6 binding increased in association with regional histone H3-K9/14 acetylation and H3-K4 methylation. The expression of all chemokine genes in the gene cluster was augmented in activated A549 cells transfected with the DN-Bcl6 gene. We also induced allergic airway inflammation in Tg mice. Expression of the chemokine genes and infiltrated cell numbers in the lungs of these Tg mice with allergic airway inflammation were inversely correlated with the amount of Bcl6 in the lungs.

CONCLUSION AND CLINICAL RELEVANCE

Expression of the pulmonary epithelium-derived CC-type chemokine genes in the cluster is orchestrated by the conserved machinery related to Bcl6. Thus, Bcl6 in pulmonary epithelium may be a critical regulator for pathogenesis of various pulmonary inflammatory diseases.

Concurrent Superselective Intra-Arterial Chemotherapy and Radiotherapy for Late-Stage Squamous Cell Carcinoma of the Temporal Bone

Objectives:

This study evaluated the efficacy of concurrent superselective intra-arterial chemotherapy and radiotherapy without surgery for late-stage squamous cell carcinoma of the temporal bone, which typically has a poor prognosis.

Methods:

The subjects were 5 patients treated at our hospital between 2007 and 2010 for primary cancer of the temporal bone. One patient had a stage T3 tumor, and 4 patients had T4 tumors, according to the Pittsburgh staging system. All patients received irradiation with a conventional once-daily fraction of 2 Gy, and the total dose ranged from 60 to 66 Gy. Intra-arterial cisplatin via transfemoral catheterization and intravenous sodium thiosulfate were administered. The contribution of each vessel in supplying blood to the primary tumor was determined by real-time computed tomographic angiography.

Results:

Three patients obtained a complete response. The same 3 patients remain alive without local recurrence (mean survival, 28 months), 1 patient died of distant metastasis without local recurrence after 19 months, and 1 patient remains alive with local recurrence.

Conclusions:

Although the small number of patients prevents comparisons with other treatments, the present study obtained good results. This may become an effective treatment for patients with late-stage squamous cell carcinoma of the temporal bone.

Retrograde mastoidectomy on demand with soft-wall reconstruction in pediatric cholesteatoma

CONCLUSION

Retrograde mastoidectomy with soft-wall reconstruction is an effective technique that can be used to lower the recurrence rate of cholesteatoma in the pediatric population.

OBJECTIVE

To evaluate surgical outcomes of retrograde mastoidectomy when using soft-wall reconstruction in pediatric cholesteatoma.

METHODS

A total of 25 children underwent cholesteatoma removal surgery employing soft-wall reconstruction. The cases were retrospectively reviewed. Average follow-up time was 48.7 months. In order to fully expose and extirpate the disease, the bony canal wall was removed in association with a retrograde-type mastoidectomy in all cases. The posterior ear canal defect was then reconstructed using soft tissue; i.e. temporal fascia and canal wall skin. The incidence and localization of residual and recurrent cholesteatoma, preoperative and postoperative audiogram results, pure-tone average (PTA), and air-bone gap (ABG) were assessed.

RESULTS

Residual cholesteatoma was detected in 5 (20%) of 25 ears while recurrent cholesteatoma occurred in 1 (4%) of 25 ears. The mean preoperative PTA of air conduction (AC) was 39.1 dB, while the preoperative PTA of the ABGs was 28.8 dB. The mean postoperative PTA-AC and PTA-ABG were 20.9 dB and 11.7 dB, respectively. The mean hearing gain was 18.2 dB. The differences between the pre- and postoperative values were statistically significant (p < 0.05).

Prognostic factors for squamous cell carcinoma of the temporal bone: extensive bone involvement or extensive soft tissue involvement?

CONCLUSION

Extensive bone erosion correlated with a worse prognosis of the squamous cell carcinoma (SCC) of the temporal bone but extensive soft tissue involvement did not correlate with prognosis in this study. Resectability of the tumor seems to be major prognostic factor of temporal bone SCC.

OBJECTIVE

Prognostic factors for SCC of the temporal bone were evaluated regarding initial clinical symptoms and radiographic imaging.

PATIENTS AND METHODS

Clinical symptoms of the patients with primary SCC of the external auditory canal (EAC) or middle ear (ME) were reviewed based on medical records. Correlation of clinical symptoms and cancer severity staging using the modified Pittsburgh classification was analyzed, along with disease-specific survival (DSS).

RESULTS

Sixteen patients with primary SCC of the EAC (n=13) or ME (n=3) were included in the study population. DSS was not influenced by whether a hearing disturbance or otalgia was noted at the first medical examination. Extended bone involvement identified with imaging studies significantly correlated with worse prognosis (p<0.05). Prognoses of patients without extensive bone erosion were good, and extensive (> or =0.5 cm) soft tissue involvement did not correlate with prognosis in this study. Prognoses of patients with insufficient bone resection or no surgery were significantly poor (p<0.01).

Changes in calbindin-D28k and parvalbumin expression in the superior olivary complex following unilateral cochlear ablation in neonatal rats

CONCLUSION

Unilateral congenital deafness with a volume reduction in cochlear nucleus (CN) induced changes in the calcium-binding proteins (CaBPs) in the contralateral superior olivary complex (SOC) in the rat. With the loss of neurons and a volume reduction in the CN, a decrease in the input to the contralateral SOC may occur, which results in the down-regulation of CaBPs in these nuclei. This study may provide some implications regarding the neurochemistry in the auditory brainstem of deaf children.

OBJECTIVE

Hearing loss produced by cochlear damage during early development can result in persistent changes in the organization of the central auditory system in adults. The purpose of the present study was to investigate the neurochemical changes produced in the auditory brainstem of rats with unilateral cochlear ablation conducted before the onset of hearing.

MATERIALS AND METHODS

Following unilateral cochlear ablation during early development, we examined the changes in the distribution of two CaBPs, calbindin-D28k (CB) and parvalbumin (PV), in the SOC.

RESULTS

Upon reaching adulthood, a marked decrease in CB- and PV-immunoreactive neurons was observed in the contralateral SOC, particularly in the medial nucleus of the trapezoid body (MNTB), although no neuronal cell death was observed. A volume reduction in the ipsilateral CN was also observed.

Neuroprotective effects of vitamin E on adult rat motor neurones following facial nerve avulsion

CONCLUSION

The present study demonstrates the neuroprotective effect of vitamin E after peripheral facial nerve injury. Antioxidants may have therapeutic potential in traumatic facial nerve dysfunction resulting from traumatic temporal bone injury and ear surgery.

OBJECTIVE

We investigated the possible neuroprotective effect of vitamin E on the facial motor nucleus (FMN) motor neurones after peripheral nerve avulsion.

METHODS

In 36 adult rats, the right facial nerve was avulsed from the stylomastoid foramen. Following nerve avulsion, immunohistochemistry was used to investigate the effects of vitamin E on 4-hydroxynonenal (HNE) activity. FMN motor neurones and glial cells were counted bilaterally in sections stained with cresyl violet.

RESULTS

Rats administered vitamin E exhibited clear suppression of injury-induced neuronal HNE expression in the ipsilateral FMN as compared to non-treated controls. Following nerve avulsion, the number of surviving motor neurones in the ipsilateral FMN was significantly greater among vitamin E-treated rats than non-treated controls.

Vitamin E and vitamin C in the treatment of idiopathic sudden sensorineural hearing loss

CONCLUSION

The results of this study suggest that the administration of vitamin E and vitamin C to patients with idiopathic sudden sensorineural hearing loss (ISSHL) has beneficial effects by reducing the level of reactive oxygen metabolites produced by inner ear ischaemia and reperfusion injury after treatment.

OBJECTIVES

The purpose of this study was to investigate the efficacy of antioxidant vitamin E and vitamin C in the treatment of ISSHL.

PATIENTS AND METHODS

In a retrospective chart review, a total of 87 patients were enrolled who fulfilled the following inclusion criteria: 1) sudden onset of sensorineural hearing loss, 2) cause of hearing loss unknown, 3) hearing loss did not fluctuate, 4) arithmetic mean of hearing levels at 250, 500, 1000, 2000 and 4000 Hz exceeded 40 dB and 5) treatment was started within 14 days from the onset of hearing loss. All the patients were treated with steroids and/or alprostadil. In the study group, patients additionally received vitamin E (tocopherol nicotinate, 600 mg/day) and vitamin C (1200 mg/day) orally.

RESULTS

The hearing gain after therapy was 29.4 dB and the improvement rate was 63.3% in the study group, compared with 18.5 dB and 44.0% in the control group. Significant improvement was seen in the hearing gain and recovery rate in the study group.

4-Hydroxy-2,5-dimethyl-3(2H)-furanone (HDMF) production in simple media by lactic acid bacterium, Lactococcus lactis subsp. cremoris IFO 3427

4-Hydroxy-2,5-dimethyl-3(2H)-furanone (HDMF) was detected in simple media prepared with heated sugar and amino acid solution as a result of the Maillard reaction. However, an increase in the amount of HDMF was observed in the media fermented by Lactococcus lactis subsp. cremoris IFO 3427. 4-Hydroxy-2(or 5)-ethyl-5(or 2)-methyl-3(2H)-furanone (HEMF) was not detected in all the simple media examined in this study.

Resolving the discrepancy of 135 MeV pd elastic scattering cross sections and relativistic effects

Three precise measurements for elastic pd scattering at 135 MeV/A have been performed with the three different experimental setups. The cross sections are described well by the theoretical predictions based on modern nucleon-nucleon forces combined with three-nucleon forces. Relativistic Faddeev calculations show that relativistic effects are restricted to backward angles. This result supports the two measurements recently reported by RIKEN and contradicts the KVI data.

Syenergistic effect of 15-deoxyspergualin with costimulation blockade on alloimmune response

INTRODUCTION

A virally induced alloreactive memory seems to represent a potent barrier to tolerance induction but the combination of 15-deoxyspergualin (DSG), an inhibitor of NFkB translocation, with costimulation blockade (CB)-based chimerism as an induction regimen can overcome a preformed anti-donor memory response. In this study, we investigate the ability of DSG with CB to inhibit a naive alloimmune responses.

METHODS

A BALB/c (H-2d) skin or heart was transplanted into a C57BL/6 (H-2b) recipient treated with anti-CD154 mAb (MR1; 500 mcg/d on days 0, 2, 4, 6) alone, DSG (5 mg/kg/d, days 0 to 7) alone, or both agents. Proliferation of alloreactive T cells after each treatment was also examined using a graft-versus-host disease (GvHD) model using the fluorescent dye CFSE.

RESULTS

Treatment with DSG alone induced prolonged survival of the cardiac allografts (median survival time [MST]: 97.5 days). MR1 alone induced indefinite survival of cardiac allografts, although at 150 days after transplantation, the histology showed changes characteristic of chronic rejection, including interstitial fibrosis, infiltration of mononuclear cells, and intimal hyperplasia in coronary vessels. Combined treatment with DSG and MR1 induced donor-specific unresponsiveness in all recipients, graft histology showed only minimal infiltration. Treatment with DSG and MR1 also significantly prolonged the survival of skin allografts (MST: 31 days) compared with that of DSG or MR1 alone (MST: 17 and 14 days, respectively). In the GvHD model assessed with CFSE, the combined treatment was the more effective to suppress proliferation of alloreactive T cells while DSG alone inhibited proliferation more than MR1 alone.

CONCLUSION

DSG potentiates anti-CD154 therapy to suppress the alloimmune response.

Role of Glu318 at the putative distal site in the catalytic function of cytochrome P450d

Most microsomal P450s have a conserved "threonine cluster" composed of three Thrs (Thr319, Thr321, Thr322 for P450d) at a putative distal site. An ionic amino acid at 318 is also well conserved as Glu or Asp for most P450s. To understand the role of these conserved polar amino acids at the putative distal site in the catalytic function of microsomal P450, we studied how mutations at this site of P450d influence the activation of molecular oxygen in the reconstituted system. Catalytic activity (0.02 min-1) toward 7-ethoxycoumarin of the Glu318Ala mutant of P450d was just 6% of that (0.33 min-1) of the wild type, while those of Glu318Asp, Thr319Ala, and Thr322Ala were comparable to or even higher than that of the wild type. Consumption rates of O2 and formation rates of H2O2 of those mutants varied in accord with the catalytic activities. Especially, the efficiency (0.5%) of incorporated oxygen atom to the substrate versus produced H2O2 for the Glu318Ala mutant was much lower than that (3.7%) of the wild type, while that (58.8%) for the mutant Glu318Asp was 16-fold higher than that of the wild type. In addition, the autoxidation [Fe(II)---- Fe(III)] rate (0.074 s-1) of the Glu318Ala mutant was much lower than those (0.374-0.803 s-1) of the wild type and other mutants. Thus, we strongly suggest that Glu318 plays an important role in the catalytic function toward 7-ethoxycoumarin of microsomal P450d.

Tissue-specific expression of a suicide gene for selective killing of neuroblastoma cells using a promoter region of the NCX gene

The human NCX gene, a homologue of the murine neural crest homeobox (Ncx/Hox11L.1) gene whose expression is restricted to a subset of neural crest-derived tissues, was expressed in human neuroblastoma cells but not in other tumors or fibroblasts. A 4.5-kb genomic fragment in the 5'-flanking region of the NCX gene efficiently transcribed the fused luciferase reporter gene in human neuroblastoma cells but not in non-neuroblastoma cells. Sequential deletion of this regulatory region from the 5' side demonstrated that a 1.7-kb fragment upstream from the start codon retained the preferential promoter activity in neuroblastoma cells. The transcriptional activation by the NCX promoter was stronger than that by the SV40 T antigen promoter in human neuroblastoma cells. Transfection of neuroblastoma cells with the NCX promoter-linked herpes simplex virus-thymidine kinase (HSV-TK) gene increased their sensitivity to ganciclovir. The regulatory region of the NCX gene is thus useful for neuroblastoma-specific suicide gene therapy.

Isoform-dependent interaction of BRDG1 with Tec kinase

Tec is the prototype of an emerging family of protein-tyrosine kinases. Tec and Btk, another member of this family, together participate in the development of B-cell immune system. We previously identified one of the downstream messengers for human Tec kinase, BRDG1. BRDG1 is associated with Tec and becomes tyrosine-phosphorylated in B-cells by the engagement of B-cell antigen receptor (BCR). Here we show that overexpression of BRDG1 strongly augments BCR-mediated activation of cAMP-response element binding protein (CREB) but not that of c-Jun and the promoters of c-MYC and BCL-xL genes. Furthermore, we isolated the murine orthologue of BRDG1. Three isoforms of BRDG1 are generated by alternative splicing of the message. Two of them have a deletion of 33 amino acids in a Pleckstrin homology (PH) domain of BRDG1. Both the tyrosine-phosphorylation and CREB-activating ability of BRDG1 were isoform-dependent, suggesting a role of the PH domain of BRDG1. These data have identified a novel regulatory mechanism of CREB family of transcriptional factors.

Glutaminergic vagal afferents may mediate both retching and gastric adaptive relaxation in dogs

We previously reported that intra-4th-ventricular (i.4th.v.) administration of a non-NMDA receptor antagonist, NBQX, abolished vagally induced retching. This study was undertaken to ascertain whether or not the neuronal response in the solitary tract nucleus (NTS) to vagal stimulation and the vago-vagal gastric reflexes induced by non-emetic stimulation are also abolished by NBQX with a similar latency as in the case of retching. Ketamine and thiopental- or chloralose-anesthetized dogs were decerebrated, and the dorsal surface of the medulla was exposed. This study consisted of two series of experiments. In the first series, extracellular neuronal responses in the NTS to pulse-train vagal stimulation were recorded. Effects of NBQX on the neural response and vagally induced fictive retching were observed. In the second series, effects of glutamate receptor antagonists on gastric corpus responses to esophageal or gastric antral distension were observed. Retching was abolished 5-15 min after an i.4th.v. application of NBQX. and the neuronal responses disappeared within 14 min after application in nine of 10 NTS neurons. On the other hand, corpus contractility was inhibited by esophageal distension, and inhibited and/or enhanced by antral distension. While the inhibitory responses disappeared within 17 min after NBQX, the enhanced response remained even after NBQX and vagotomy, but was abolished by i.v. administration of hexamethonium. These results suggest that adaptive relaxation in the corpus, as well as retching, may be mediated by glutaminergic vagal afferents and non-NMDA receptors in the NTS.

A new functional domain of Bcl6 family that recruits histone deacetylases

The proto-oncogene Bcl6 and its family gene, BAZF, encode a sequence-specific transcriptional repressor which contains the BTB/POZ domain in NH(2)-terminal region and zinc finger motifs in COOH-terminal region. The BTB/POZ domain and the middle portion of Bcl6 and BAZF are known to display transrepressor activity. Since we have identified the identical 17-amino acid (aa) sequence in the middle portion of Bcl6 and BAZF, the 17aa region may be another repressive domain of the middle portion. The reporter gene assay indicates that the 27aa sequence including the 17aa region recruits histone deacetylases to express transrepressor activity. Furthermore, overexpression of Bcl6 or Bcl6(POZ-) (Bcl6 deleted with the BTB/POZ domain) induced apoptosis in NIH3T3 cells, and the apoptosis was inhibited by the addition of histone deacetylase inhibitor in the culture. However, apoptosis was not induced in NIH3T3 cells by overexpression of Bcl6(POZ-) deleted with the 17aa region. These results indicate that the 17aa region in the middle portion of Bcl6 is a functional domain of transrepressor activity and is responsible for inducibility of apoptosis in NIH3T3 cells.

Intestinal neuronal dysplasia-like pathology in Ncx/Hox11L.1 gene-deficient mice

BACKGROUND/PURPOSE

Ncx/Hox11L.1-deficient (Ncx-/-) mice specifically created by the authors had mega-ileo-ceco-colon (mega-ICC) with a caliber change in the proximal colon. The authors studied the nerve distribution in the bowel of these Ncx-/- mice to determine the cause of their bowel dysmotility.

METHODS

Four-week-old Ncx-/- mice (n = 10; 5 with mega-ICC, 5 without mega-ICC) were killed and the bowel harvested. Half of each specimen was snap frozen for AchE and NADPH-diaphorase histochemistry, and the other half were fixed with 10% formalin for H&E staining and immunohistochemistry using PGP9.5 antibody (a marker for neurons), C-kit antibody (a marker for intestinal pacemaker cells), and stem cell factor antibody (a marker for C-kit ligand). Age-matched wild-type normal mice (n = 5) served as controls.

RESULTS

In the ileum, cecum, and proximal colon from all Ncx-/- mice (irrespective of the association of mega-ICC), typical findings of human intestinal neuronal dysplasia (IND) ie, obvious hyperganglionosis in neuronal plexuses on PGP9.5 immunohistochemistry, ectopic ganglia in the mucosal and muscular layers on AchE histochemistry, and ghostlike ganglia on NADPH-diaphorase histochemistry were found. Likewise, in normal caliber distal colon from these mice, the distribution of ganglion cells, C-kit, and stem cell factor was normal. In control specimens, there was no ectopic ganglia or hyperganglionosis.

CONCLUSIONS

These findings suggest that the Ncx/Hox11L.1 gene is required for the proper innervation of the enteric nervous system in mice, and our deficient strain may be useful as a model for studying IND in humans.

Binding of BAZF and Bc16 to STAT6-binding DNA sequences

BAZF, a family member of Bcl6, can function as a sequence-specific transcriptional repressor. We determined BAZF-binding DNA sequence. The consensus binding sequence (CBS) of BAZF is almost the same as those of Bcl6 previously described. Three nucleotides of T, G and A at position 6, 8, and 9 in the CBS (5'-ATTCCTAGAAAG-3') are important nucleotides for binding of both BAZF and Bcl6. Since a part (5'-TTC-CTA-GAA-3') of the CBS resembled the sequence motif (5'-TTC-(N3-4)-GAA-3') bound by STAT factors, BAZF and Bcl6 can bind to the CD23b-STAT6-binding sequence (5'-TTTC-TTA-GAAAT-3'), the immunoglobulin germline epsilon-STAT6-binding sequence (5'-CTTC-CCAA-GAAC-3'), and the IL4-STAT6-binding sequence (5'-TTTC-CCA-GAAAA-3') with weak affinity. However, a mutation of C nucleotide to T nucleotide in the IL4-STAT6-binding sequence (5'-TTTC-CTA-GAAAA-3') strongly increased the binding activity of BAZF and Bcl6. These results suggest that BAZF and Bcl6 can repress some of STAT-induced transcription by binding to DNA sequences recognized by STAT factors.

Nd1, a novel murine Kelch family protein, may play the role of a housekeeping gene

The murine Nd1 gene encodes a novel Kelch family protein and expresses two forms of mRNA, long (Nd1-L) and short (Nd1-S), in various tissues. We characterized the genomic organization of the Nd1 gene, and found that Nd1-L and Nd1-S consist of 16 and nine exons respectively, and that exons I-VIII are shared between them. Three transcription initiation sites were identified in the 5'-flanking region and the most 3' side (+1) is likely to be a major one. Promoter analysis revealed that the region between positions -247 and -86 was sufficient for expression, and that two Sp1-binding sites and one NF-kappaB-binding site in the region were critical for promoter activity. Furthermore, the promoter region lacks a TATA and a CAAT box and has a highly GC-rich region with two important Sp1-binding sites. These characteristics of the Nd1 gene promoter are similar to the properties of housekeeping genes.

A novel homologue of the TIAP/m-survivin gene

The inhibitor of apoptosis (IAP) proteins comprise a highly conserved gene family that prevents cell death in response to a variety of stimuli. TIAP/m-survivin, a murine homologue of human Survivin, is a member of the IAP family. TIAP/m-survivin has one baculovirus IAP repeat (BIR) and lacks a C-terminal RING finger motif. Here we identified the genomic DNA region (TIAP-2) that is homologous to the TIAP/m-survivin gene by a low stringency genomic DNA hybridization. The region is on the chromomsome 9 which is distinct from that (chromosome 11) of the TIAP/m-survivin gene, and contains DNA sequence similar to a part of the BIR and the 3' side of the TIAP/m-survivin gene and the sequence homology between them is 92%. Expression of TIAP-2 mRNA was detected in various murine tissues by RT-PCR. Although expression of TIAP/m-survivin mRNA is upregulated in synchronized cells at S to G2/M phase of the cell cycle, expression of TIAP-2 mRNA was constant in the cell cycle, suggesting the different role of TIAP-2 from that of TIAP/m-survivin.