A recovery from enhancement of activation in auditory cortex of patients with idiopathic sudden sensorineural hearing loss

OBJECTIVE

We previously reported enhanced activation of auditory cortex in patients with bilateral chronic inner-ear hearing loss. To determine whether this enhancement can exhibit a short-term alteration, we measured auditory evoked magnetic fields (AEFs) in patients with idiopathic sudden sensorineural hearing loss (ISSHL) in the acute phase (AP) and recovery phases (RPs).

METHODS

We recorded AEFs in two unilateral ISSHL patients at three time points (AP, RP1, and RP2) using a whole-head neuromagnetometer. Tone bursts of 1 kHz were presented monaurally to the affected and healthy ear at four different intensities (40-70 dB HL).

RESULTS

Both patients showed the enhancement of N100 m moment at AP and not at RPs in response to the affected ear stimulation, and stronger N100 m moment in ipsilateral than contralateral hemisphere in response to the healthy ear stimulation at AP.

CONCLUSIONS

Enhancement of N100 m amplitude occurs in ISSHL patients and disappears on the scale of days. Enhancement of activity in the auditory cortex derived from inner-ear hearing loss can thus exhibit short-term change.

SIGNIFICANCE

The results of this study provide first evidence for a recovery from enhancement of activation in the auditory cortex following injury of peripheral hearing organ.

Listeriolysin O derived from Listeria monocytogenes inhibits the effector phase of an experimental allergic rhinitis induced by ovalbumin in mice

Listeriolysin O (LLO) derived from Listeria monocytogenes is highly capable of inducing interleukin (IL)-12, IL-18 and interferon (IFN)-gamma, and facilitates the generation of Th1 cells. We have recently shown that recombinant LLO (rLLO) inhibits generation of ovalbumin (OVA)-specific Th2 immune response by skewing maturation of antigen-specific T cells into Th1 cells. In the present study, we investigated the effect of rLLO on the effector phase of Th2-dependent allergic rhinitis in BALB/c mice sensitized with OVA. In mice sensitized intraperitoneally and challenged intranasally with OVA, nasal allergic symptoms such as sneezing and nose-scratching were observed at a high frequency. A high titre of anti-OVA IgE antibody was detected in sera and a large number of eosinophils migrated into the nasal tissue. However, rLLO treatment during the intranasal challenge inhibited the allergic symptoms, production of anti-OVA IgE antibody and eosinophil infiltration. Though rLLO did not affect antigen-specific cytokine production from splenic CD4(+) T cells, rLLO significantly suppressed OVA-specific IL-4 and IL-5 production from nasal mononuclear cells. We further found that rLLO inhibited the recruitment of CD4(+) T cells in nasal mucosa, and diminished the transcription and cell surface expression of CCR4 on splenic CD4(+) T cells. Moreover, rLLO was able to inhibit the passive cutaneous anaphylaxis reaction mediated by anaphylactic antibodies (IgE and IgG(1)) and mast cells. Taken together, these data showed that rLLO suppresses the effector phase of allergic rhinitis by inhibition of Th2 cell recruitment to nasal mucosa and type I allergic reaction.

Modification of allergic inflammation in murine model of rhinitis by different bacterial ligands: involvement of mast cells and dendritic cells

BACKGROUND

It has been suggested that airway bacterial infections exacerbate allergic disorders, and bacterial components in the air affect allergic inflammation via Toll-like receptors expressed on mast cells and dendritic cells in the airway mucosa.

OBJECTIVE

Peptidoglycan (PGN) is a major component of the bacterial cell wall. We investigated the effect of PGN on the effector phase of allergic inflammation, in comparison with the effect of CpG-oligodeoxynucleotides (CpG), which is known to be a Th1 adjuvant.

METHODS

Ovalbumin (OVA)-sensitized mice were challenged intranasally with OVA alone or OVA together with PGN or CpG. Nasal allergic symptoms and eosinophilia were scored, and the OVA-specific cytokine response was examined in the cells of cervical lymph nodes and nasal mucosa. Bone marrow-derived mast cells (BMMCs) and dendritic cells (BMDCs) were stimulated with PGN or CpG in vitro, and the expression level of cytokines and chemokines was examined by RT-PCR. In addition, the expression level of chemokines was examined by RT-PCR in mast cells of OVA-sensitized mice challenged with OVA alone or OVA together with PGN or CpG.

RESULTS

PGN exposure exacerbated the nasal allergic symptoms and eosinophilia, whereas CpG exposure suppressed them. In addition, PGN exposure increased the OVA-specific IL-4 response in the cells, whereas CpG exposure decreased it. On the other hand, there were no significant differences in the OVA-specific IFN-gamma response. PGN but not CpG induced the expression of thymus and activation-regulated chemokine (TARC) and macrophage/monocyte-derived chemokine (MDC) in both BMMCs and mast cells of mice sensitized and challenged with OVA. CpG but not PGN induced the expression of IFN-beta and interferon-inducible protein-10 (IP-10) in BMDCs, and histamine did not influence this effect.

CONCLUSION

These results demonstrate that PGN exposure exacerbates allergic inflammation mainly via mast cells, whereas CpG exposure suppresses allergic inflammation mainly via dendritic cells.

Autosomal recessive ataxia with peripheral neuropathy and elevated AFP: Novel mutations in SETX

Mutations in the Senataxin gene (SETX) are associated with autosomal recessive ataxia-ocular apraxia 2 (AOA2) and autosomal dominant juvenile ALS (ALS4). Here, the authors describe novel homozygous missense mutations in SETX, M274I, and R1294C, found in two siblings with ataxia, peripheral neuropathy, and increased serum alpha-fetoprotein level and three other siblings with heterozygous missense mutations who were neurologically asymptomatic. The results demonstrate that the double missense mutations are responsible for AOA2 but not for ALS4.

Rapidly progressive glomerulonephritis in a patient with Chlamydia pneumoniae infection: a possibility of superantigenic mechanism of its pathogenesis

Herein we describe a case of a patient with rapidly progressive glomerulonephritis after Chlamydia pneumoniae infection. An 88-year-old woman who had had C. pneumoniae infection two months previously was admitted to our hospital with complaints of dyspnea and generalized edema. Laboratory tests revealed acute renal failure, polyclonal hypergammaglobulinemia, highly increased level of C-reactive protein, and hematoproteinuria. A renal biopsy revealed mesangial and endocapillary proliferative glomerulonephritis with crescents. She responded to high-dose steroids, cyclophosphamide, minocycline, and plasma exchange treatment with the remission of oliguric renal failure. The percentage of the subset of CD3+ TCR+ Vbeta11+ cells markedly increased to 9.6% (normal range: < 1.04%) at the onset of the disease and decreased to 0.1% after the treatment. These clinicopathological features were similar to those of superantigen-associated glomerulonephritis after methicillin-resistant Staphylococcus aureus infection. We suggest that the superantigenic mechanism is one of the possible pathomechanisms of this glomerulonephritis.

Listeriolysin O, a cytolysin derived from Listeria monocytogenes, inhibits generation of ovalbumin-specific Th2 immune response by skewing maturation of antigen-specific T cells into Th1 cells

Listeriolysin O (LLO), a cholesterol-dependent cytolysin derived from Listeria monocytogenes, is a potent inducer of interleukin (IL)-12, IL-18 and interferon (IFN)-gamma. We have shown that LLO facilitates development of T cells mediating protective immunity against L. monocytogenes through the induction of IFN-gamma production at an early stage. Based on this finding, it is postulated that LLO inhibits differentiation of Th2 cells and the Th2 immune response. By using a murine model of ovalbumin (OVA)-induced allergic rhinitis, we investigated whether LLO has an ability to modulate the Th2-type immune disorder. In mice sensitized intraperitoneally with ovalbumin (OVA)/alum and challenged intranasally with OVA, a large number of eosinophils migrated into the nasal tissue, and high titres of anti-OVA IgE and IgG(1) antibodies were detected in sera. However, LLO treatment during sensitization markedly inhibited the eosinophil infiltration and production of these anti-OVA antibodies. A large number of T cells from mice sensitized and challenged with OVA produced high level of IL-4 and IL-5 but not IFN-gamma after stimulation with OVA. In contrast, OVA-specific IFN-gamma-producing T cells were preferentially induced in mice treated with LLO at the time of sensitization. In the absence of LLO administration, the expression level of GATA-3 and SOCS-3 in CD4(+) T cells was enhanced after sensitization with OVA. LLO treatment resulted in a reduction of GATA-3 and SOCS-3 expressions but induced the transcription of T-bet instead. Taken together, these data show clearly that LLO is capable of inhibiting Th2 immune response by skewing differentiation of antigen-specific T cells into Th1 cells.

Pulmonary Adenosquamous Carcinoma in a Dog

A mass that developed in the lung of a 10-year-old mixed-breed dog was pathologically examined. Histopathological examination showed papillary and tubular growth of glandular epithelium-like cells in some areas and growth of squamous cells arranged in nests in other areas, showing coexistence of adenocarcinoma and squamous cell carcinoma in a lung tumour. Immunohistochemical staining with anti-keratin-cytokeratin antibody was strongly positive for cytoplasms in both components. Electron microscopically, the neoplastic cells of the adenocarcinoma component had features of glandular cells, with microvilli, numerous free ribosomes, large round secretory granules and intercellular desmosomes. Non-keratinized squamous cells had tonofilaments and intercellular desmosomes. These findings led to the diagnosis of primary adenosquamous carcinoma, which demonstrates phenotypic profiles characteristic of both epidermal keratinocytes and glandular epithelium.

Cell therapy for inner ear diseases

Degeneration of inner ear cells, especially sensory hair cells and associated neurons, results in hearing impairment and balance disorders. These disabilities are incurable because loss of hair cells and associated neurons is currently irreversible. Protection or regeneration of hair cells and associated neurons is an important area of research for developing an effective treatment for inner ear diseases. Cell therapy is a rapidly growing area of research and has potential applications in the treatment of inner ear disorders. The first attempts to examine the feasibility of cell therapy in the treatment of inner ear disorders have been performed using neural stem cells (NSCs). Grafted NSCs can survive in the inner ear and differentiate into neural, glial and/or hair cell-phenotypes, making NSC transplantation for the restoration of inner ear cells a potentially viable treatment. Further studies have suggested embryonic stem cells (ESCs), dorsal ganglion cells and cell lines derived from fetal inner ear cells could be used to restore damaged inner ear cells. Cell transplantation has also been suggested as a strategy for drug delivery into the inner ear, and the ability of NSC-derived cells to produce neurotrophins in the inner ear has been demonstrated. Results from studies using autologous bone marrow stromal cells (MSCs) indicate a high survival and migration potential suggesting that MSCs can be used as a drug delivery vehicle to the inner ear. These cell transplantation findings provide a sound foundation for the development of therapies to treat inner ear disorders.

Whole genomewide linkage screen for neural tube defects reveals regions of interest on chromosomes 7 and 10

Neural tube defects (NTDs) are the second most common birth defects (1 in 1000 live births) in the world. Periconceptional maternal folate supplementation reduces NTD risk by 50-70%; however, studies of folate related and other developmental genes in humans have failed to definitively identify a major causal gene for NTD. The aetiology of NTDs remains unknown and both genetic and environmental factors are implicated. We present findings from a microsatellite based screen of 44 multiplex pedigrees ascertained through the NTD Collaborative Group. For the linkage analysis, we defined our phenotype narrowly by considering individuals with a lumbosacral level myelomeningocele as affected, then we expanded the phenotype to include all types of NTDs. Two point parametric analyses were performed using VITESSE and HOMOG. Multipoint parametric and nonparametric analyses were performed using ALLEGRO. Initial results identified chromosomes 7 and 10, both with maximum parametric multipoint lod scores (Mlod) >2.0. Chromosome 7 produced the highest score in the 24 cM interval between D7S3056 and D7S3051 (parametric Mlod 2.45; nonparametric Mlod 1.89). Further investigation demonstrated that results on chromosome 7 were being primarily driven by a single large pedigree (parametric Mlod 2.40). When this family was removed from analysis, chromosome 10 was the most interesting region, with a peak Mlod of 2.25 at D10S1731. Based on mouse human synteny, two candidate genes (Meox2, Twist1) were identified on chromosome 7. A review of public databases revealed three biologically plausible candidates (FGFR2, GFRA1, Pax2) on chromosome 10. The results from this screen provide valuable positional data for prioritisation of candidate gene assessment in future studies of NTDs.

Elastic moduli of thyroid tissues under compression

The aim of this study was to evaluate the elastic moduli of thyroid tissues under uniaxial compression and to establish the biomechanical fundamentals for accurate interpretation of thyroid elastograms. A total of 67 thyroid samples (24 samples of normal thyroid tissue, 2 samples of thyroid tissue with chronic thyroiditis, 12 samples of adenomatous goiter lesions and 7 samples of follicular adenoma, 19 samples of papillary adenocarcinoma (PAC) and 3 samples of follicular adenocarcinoma (FAC)) obtained from 36 patients who had received thyroid surgery were subjected to biomechanical testing within three hours after surgical resection at precompression strains of 5%, 10% and 20% and applied strains of 1%, 2%, 5% and 10% of sample height. As a result, the mean values of elastic moduli for benign thyroid lesions at all examined precompression levels were significantly higher than those for normal thyroid tissue measured at the same load (p<0.01). At low precompression (5%) and compression (1-2%) levels, benign thyroid nodule samples were 1.7 times harder than normal thyroid tissue. At high precompression (20%) and compression (10%) levels, this difference increased to 2.4 times. Stiffness of PAC samples was significantly higher than those for normal thyroid tissue and benign thyroid tumors measured at the same load (p<0.01). At low precompression (5%) and compression (1-2%) levels, PAC samples were 5.0 times harder than normal thyroid tissue. At high precompression (20%) and compression (10%) levels, this difference increased to 17.7 times. In contrast, samples of FAC were much softer than PAC (p<0.05) and were comparable in stiffness to normal thyroid tissues. The significant differences in the stiffness between normal thyroid tissue and thyroid tumors may provide useful information for accurate interpretation of thyroid elastograms.

Effect of P-deficiency on photoassimilate partitioning and rhythmic changes in fruit and stem diameter of tomato (Lycopersicon esculentum) during fruit growth

Tomato (Lycopersicon esculentum) plants were grown in liquid culture inside the greenhouse of Hiroshima University, Japan. At the first fruiting stage, P was withdrawn from the rooting medium for a period of 19 d and its effect was studied on photosynthesis, stomatal conductance, transpiration, partitioning of 13C and 15N, P contents of various organs, and changes in stem and fruit diameter of the plant in order to identify the mechanism of resource management on the part of the plant at low P. Compared to the control, P-deficiency treatment decreased biomass growth of all organs except the roots. The treatment also depressed leaf photosynthesis, stomatal conductance and diameter of fruit and stem after a lag period of about 1 week. The stem diameter of the plant shrank during daytime and expanded during the night; the adverse effect of P-deficiency on stem diameter change was more evident during the night than the day. The circadian rhythm in fluctuations of diameter was less manifested in the fruit compared with the stem. P-deficiency induced daytime shrinkage and reduced night expansion of fruit. However, within the plant, P-deficiency encouraged partitioning of 13C, 15N and P into the fruit at the cost of autotrophic organs such as leaves and the upper parts of the stem. The results were discussed in the light of a plausible effect of P-deficiency on water relations of the plant. It is concluded that, in spite of the preference in partitioning of C and N received within the plant parts, assimilate flow into the fruit is limited at low-P compared with the control, owing to the restriction in fruit expansion.

Phosphatidylinositol 3-kinase in cumulus cells is responsible for both suppression of spontaneous maturation and induction of gonadotropin-stimulated maturation of porcine oocytes

In this study, we investigated the mechanisms of protein kinase B (PKB) activation and its role in cumulus cells during in vitro meiotic resumption of porcine oocytes. PKB activity in cumulus cells was significantly decreased by 12 h cultivation of cumulus-oocyte complexes (COCs) in basic medium. However, the addition of phosphodiesterase inhibitors, hypoxanthine or 3-isobutyl-1-methylxanthine, maintained the level of PKB activity in cumulus cells at comparable with that in cumulus cells just after collection from their follicles. When COCs were cultured with phosphatidylinositol 3-kinase (PI 3-kinase) inhibitor, LY294002, PKB activity was significantly decreased, and both caspase 3 activity and the proportion of apoptotic cells were significantly increased as compared with those in cumulus cells just after collection from their follicles. Moreover, the inhibitory effect of hypoxanthine on spontaneous meiotic resumption was overcome by addition of LY294002. On the other hand, markedly high activity of PKB and high intensity of the phosphorylated PKB band were observed in cumulus cells of COCs which were cultured with FSH. The addition of 20 microM LY294002 to FSH-containing medium induced an apoptosis of cumulus cells, whereas little apoptotic-positive signal was detected in COCs cultured with 5 microM LY294002 and FSH. However, the inhibitory effects of LY294002 on progesterone production by cumulus cells and germinal vesicle breakdown in oocytes reached a maximum at 5 microM. Thus, high activity of the PI 3-kinase-PKB pathway in cumulus cells plays an important role in FSH regulation of cell function. Judging from these results, it is estimated that PI 3-kinase in cumulus cells is required for both the suppression of spontaneous meiotic resumption and the induction of gonadotropin-stimulated meiotic resumption.

Mucosal sulfhydryl compounds evaluation by in vivo electron spin resonance spectroscopy in mice with experimental colitis

BACKGROUND

Sulfhydryl (SH) compounds are essential in maintaining mucosal integrity in the gastrointestinal tract. A decrease in colonic mucosal SH compounds affects the redox status of the mucosa, resulting in vulnerability to further attacks. Therefore, there is a strong need for in vivo evaluation of SH compounds in the colonic mucosa.

AIMS

The aim of the current study was to establish a method of evaluating levels of SH compounds in the colonic mucosa of live animals before and after induction of colitis.

METHODS

Murine experimental colitis was induced by instillation of trinitrobenzene sulphonic acid (TNBS) dissolved in 50% ethanol into the colon via the anus. For evaluation of mucosal SH compounds in the colon, 3-carbamoyl-2,2,5,5-tetramethylpyrrolidine-1-oxyl (carbamoyl-PROXYL), a stable nitroxide radical, was instilled into the colonic lumen of live mice and the spin clearance rate was measured by L-band electron spin resonance (ESR) spectroscopy.

RESULTS

Morphological study showed that mucosal damage was severe one or two days after TNBS instillation. The colonic mucosa started to regenerate at four days, and looked normal at seven days, after induction of colitis. The spin clearance rate of carbamoyl-PROXYL decreased significantly at 0.5, 1, 2, and 4 days after induction of colitis compared with mice before TNBS instillation. Surprisingly, although the colonic mucosa looked normal seven days after TNBS administration, the spin clearance rate still remained significantly slow. The spin clearance rate returned to normal 14 days after induction of colitis. The change in in vivo spin clearance rate was consistent with the time dependent change in mucosal reduced glutathione, a major component of SH compounds.

CONCLUSION

The spin clearance rate obtained by L-band ESR spectroscopy in combination with carbamoyl-PROXYL can give an estimate of the level of colonic mucosal SH compounds in live animals and is useful for evaluating the mucosal defence system against oxidative stress.

Surgical treatment for large and massive tears of the rotator cuff

Patients with a large or massive tear of the rotator cuff were, when possible, treated with the McLaughlin procedure. A patch graft was used when it was impossible to perform this procedure. The patch group (group P) consisted of nine patients with nine shoulders (six men, three women) with a mean age of 62.8+/-6.9 years. The McLaughlin group (group M) consisted of 12 patients with 12 shoulders (ten men, two women) with a mean age of 52.3+/-8.6 years. Mean follow-up was 2 years 11 months in group P and 4 years 2 months in group M. Using the shoulder scoring system of the Japanese Orthopaedic Association (JOA score), the total score improved post-operatively in both groups. In group P, the post-operative score was 91.7 (pre-operative score 47.9) and in group M 92.0 (pre-operative score 54.2). Tears recurred in three shoulders within 2 months of the McLaughlin procedure, and these patients were excluded from the study. The rate of 're-tearing' was lower with a patch graft (0/13) than with the McLaughlin procedure (3/17).

Enhanced activation of the auditory cortex in patients with inner-ear hearing impairment: a magnetoencephalographic study

OBJECTIVE

Injury of peripheral auditory organ often induces abnormality of loudness sensation such as loudness recruitment. However, objective evaluation of this phenomenon has rarely been performed. To elucidate this abnormal loudness sensation, cortical mechanisms were investigated by recording auditory evoked magnetic fields (AEFs).

METHODS

We recorded AEFs in 8 patients suffering from inner-ear hearing impairment with loudness recruitment and in 14 healthy hearing controls using a 122-channel whole-head neuromagnetometer. Tone bursts of 1 kHz were presented monaurally at 4 different intensities (40, 50, 60, 70 dB HL) with a constant interstimulus interval of 1 s.

RESULTS

In both groups, the 100 ms response (N100m) increased in amplitude and decreased in latency as a function of stimulus intensity in both hemispheres. Concerning the source strength, increment of dipole moment of N100m was more rapid according to the stimulus intensity in patients compared with that in healthy subjects. Source strength of N100m was enhanced at high stimulus intensity in patients, and its ratio to healthy subjects was 1.08 at 50 dB, 1.69 at 60 dB and 2.04 at 70 dB.

CONCLUSIONS

In patients with inner-ear hearing impairment, enhanced activation of the auditory cortex was observed, and may help explain loudness recruitment.

A study of volumetric visualization and quantitative evaluation of bone trabeculae in helical CT

OBJECTIVES

The aim of this study was to investigate the reliability of quantitative evaluation of bone trabeculae by helical CT.

METHODS

Ten specimens of human cadaver mandibular condyles were examined using both micro-CT and helical CT, and volume rendered three-dimensional (3D) images were obtained from the CT data. Micro-CT was used as the reference standard. From the micro-CT data images, bone trabeculae in each condyle were extracted by image processing and their volumes were calculated automatically. From the helical CT data images, the cortical bone was manually removed and bone trabeculae in each condyle were extracted using opacity curve and colour mapping thresholds. The optimal cut-off CT value that resulted in a similar volume of bone trabeculae obtained from helical CT and micro-CT data was investigated.

RESULTS

The optimal cut-off CT value to assess the volume of bone trabeculae accurately on 3D images obtained with helical CT data was found to be 200 Hounsfield units.

CONCLUSIONS

This study suggests that quantitative evaluation of bone trabeculae using helical CT might be a valid and useful method.