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Ken-ichi Nibu

Publications and source records attributed to Ken-ichi Nibu.

At least 19 recordsLinked to original sources
PubMed2007

Retropharyngeal node metastasis from papillary thyroid carcinoma.

BACKGROUND: Papillary thyroid carcinomas commonly metastasize to paratracheal and jugular lymph nodes. Metastasis to the retropharyngeal node is rare for this tumor. METHODS: Five patients underwent surgical treatment for metastasis of thyroid papillary carcinoma to the retropharyngeal lymph nodes that presented as a parapharyngeal or retropharyngeal mass. All patients had a history of total or subtotal thyroidectomy as their initial treatment. Among them, 3 patients had undergone ipsilateral modified radical neck dissection at their initial treatment. The other 2 patients had a history of bilateral or ipsilateral modified neck dissection for their subsequent cervical lymph node metastases. RESULTS: Metastatic retropharyngeal nodes were successfully resected via transcervical approach in all patients. Although aspiration and difficulty in swallowing were observed in 2 patients after surgical treatment for metastatic retropharyngeal nodes, these complications spontaneously resolved within a few months. CONCLUSIONS: This study suggests that neck dissection and/or metastatic cervical lymph nodes might alter the direction of lymphatic drainage to the retrograde fashion, resulting in the unusual metastasis to the retropharyngeal lymph nodes. Although the cases described here are rare, metastasis to the retropharyngeal node should be considered at the follow-up for thyroid papillary carcinoma. Because these metastases will be missed by routine ultrasonography of the neck, periodic CT scan or MRI is recommended for follow-up, especially for patients with a history of neck dissection.

Adult↗
PubMed2006

Age-related changes in cell density and the proliferation rate of olfactory ensheathing cells in the lamina propria of postnatal mouse olfactory mucosa.

We investigated age-related changes in the distribution and proliferation of olfactory ensheathing cells (OECs) in postnatal mouse olfactory mucosa. In contrast to reported data on other glial cell types in the peripheral and central nervous systems, OEC cell density in the olfactory nerve bundles in the lamina propria remained almost constant from 10 days through 16 months of age. Electron microscopy of the nerve bundles revealed that axon packing density also was constant during that period. These findings suggest that the ratio of the number of OECs to the unit length of the olfactory neuron axons ensheathed by them does not change markedly throughout the lifetime of mice in an undisturbed condition. By contrast, OEC proliferative density decreased rapidly in the 10-day to 1-month-old period, showing a significant difference, and for the rest of life remained at low level, similar to previous values reported for other glial cell types.

Aging↗
PubMed2006

Microscopic polyangiitis histologically confirmed by biopsy from nasal cavity and paranasal sinuses: a case report.

Microscopic polyangiitis (MPA) is a systemic necrotizing vasculitis affecting small vessels without necrotizing granulomatous inflammation and is commonly associated with necrotizing glomerulonephritis. Diagnosis is based on typical clinical features, the presence of antimyeloperoxidase-antineutrophil cytoplasmic antibodies (MPO-ANCA), and histopathologic findings. Cases of pathologically proven small-vessel vasculitis in nasal biopsy specimens are sparse. Here we report a patient with MPA that was histopathologically confirmed by nasal and paranasal biopsy. A 67-year-old man presented with fever and general fatigue. Laboratory examinations showed severe inflammation and acute progressive renal failure. The serum MPO-ANCA level was elevated. The patient also had nasal polyps that seemed to be nonspecific chronic sinusitis. To obtain a pathologic diagnosis, bilateral ethmoidectomy and nasal polypectomy were performed. Pathological findings revealed vasculitis of small vessels in the mucosal surface. MPA was diagnosed on the basis of clinical symptoms, elevated MPO-ANCA and the pathological findings of the nasal and paranasal surgical specimen.

Administration, Oral↗
PubMed2006

Bcl-2 expression mediated by Cre/loxP system in olfactory epithelium.

To study the Bcl-2 expression mediated by the Cre/loxP recombination system and its effect on prevention of apoptosis in olfactory epithelium. Adenoviral vectors with cassette for Bcl-2 (AxCALNLBcl-2) and Cre recombinase (AxCANCre) were applied to mouse olfactory epithelium by intranasal instillation. The effect of exogenous Bcl-2 expression on prevention of apoptosis of olfactory receptor neurons was investigated using an apoptosis model induced by bulbectomy. The Bcl-2 product was expressed not only in the olfactory receptor neurons but also in the supporting cells. Although statistical analysis did not show significant difference, the number of apoptotic cells in the infected olfactory epithelium on post-bulbectomy day 2 was lower than that of control and the number of survived mature olfactory receptor neurons in the infected olfactory epithelium on post-bulbectomy day 5 was higher than that of control. Although further studies are required for clinical application, the results of our study suggest that this strategy may be able to deliver exogenous Bcl-2 for the treatment of degeneration of olfactory receptor neurons.

Adenoviridae↗
PubMed2006

Analysis of prognostic factors of nasopharyngeal carcinoma: impact of in situ hybridization for Epstein-Barr virus encoded small RNA 1.

OBJECTIVES: To evaluate the impact of clinical, histopathological, and molecular biological parameters on the prognosis of nasopharyngeal carcinoma (NPC). STUDY DESIGN AND SETTING: The clinical records of 48 patients with a diagnosis of NPC were retrospectively reviewed. In situ hybridization for Epstein-Barr virus encoded small RNA 1 (EBER-ISH) was applied for 30 paraffin-embedded specimens available. Prognostic factors of NPC were meticulously analyzed. RESULTS: The EBER-ISH signal was shown to be highly significant as a favorable prognostic factor (P = 0.007). Although EBV was more commonly associated with Type III NPC, EBER-ISH-positive Type I-II NPC had also significantly better survival rate than EBER-ISH-negative Type I-II NPC (P = 0.036). CONCLUSIONS: In addition to the WHO histopathological grade, the 1997 UICC staging, nodal status, and distant metastasis at presentation, the EBER-ISH signal was shown to be significant as a prognostic factor. SIGNIFICANCE: This is the first report to describe the EBER-ISH as an independent prognostic factor of NPC regardless of histopathology. EBM RATING: B-2b.

Adult↗
PubMed2006

Simple reconstruction with titanium mesh and radial forearm flap after globe-sparing total maxillectomy: a 5-year follow-up study.

BACKGROUND: Reconstruction of eye globe-sparing total maxillectomy defects is one of the major challenges to reconstructive surgeons. In 1994, the authors developed an uncomplicated and easy reconstructive method, where a titanium mesh is applied for the support of orbital contents, a radial forearm free flap for covering the mesh and the cheek lining, and an obturator prosthesis for palatal and dental rehabilitation. METHODS: Five patients who underwent primary reconstruction with the authors' method after globe-sparing maxillectomy with loss of the orbital floor from 1994 to 1999 and who were followed up for more than 5 years were retrospectively reviewed for (1) the presence of diplopia, (2) the shape of the reconstructed orbital floor assessed by coronal section magnetic resonance imaging, and (3) the presence of infection/exposure of the titanium mesh. RESULTS: Only one of the five patients developed slight diplopia. Coronal magnetic resonance imaging showed that the orbital floor restored with titanium mesh had in all cases maintained a proper shape and position for more than 5 years. No infection or exposure of the titanium mesh had developed in any of the cases, despite exposure to irradiation of not less than 30 Gy. All the patients had well-retentive obturator prostheses. CONCLUSION: This long-term follow-up study demonstrated that the authors' method attained a long-lasting successful outcome functionally and is the method of choice for reconstruction after globe-sparing total maxillectomy.

Aged↗
PubMed2005

A replication-selective adenoviral vector for head and neck cancers.

OBJECTIVE: To test the oncolytic activity of cyclo-oxygenase 2 (COX-2) promoter-based conditional replication-selective adenovirus vector for squamous cell carcinoma cells of the head and neck. DESIGN: In vitro study. SUBJECTS: None. INTERVENTIONS: A conditional replication-selective adenovirus vector in which the expression of E1a, required for viral replication, is controlled by the COX-2 promoter, Ad-COX2-E1a, was generated. Its oncolytic activity according to the levels of COX-2 and of Coxsackie and adenovirus receptor expression was tested in a series of human head and neck squamous cell carcinoma cell lines. RESULTS: The respective COX-2 messenger RNA expression ratios of KB, H891, T891, T892, and L871 were 1.5, 60.0, 1.0, 14.6, and 1.3. The corresponding Coxsackie and adenovirus receptor messenger RNA expression ratios were 1, 1, 5, 3, and 1. In vitro assays showed significant growth suppression of cancer cell lines with strong expressions of COX-2. CONCLUSION: This study demonstrated the possibility of oncolytic therapy using the COX-2 promoter-based conditional replication-selective adenovirus for head and neck squamous cell carcinoma expressing COX-2.

Adenoviruses, Human↗
PubMed2005

Laryngeal squamous cell carcinoma with ectopic production of granulocyte colony-stimulating factor and parathyroid hormone-related protein.

It is known that malignant tumors occasionally produce hormone-like substances. However, they rarely produce two or more kinds of hormonal factors simultaneously. We describe the clinical, biochemical, and immunohistochemical findings in a patient with squamous cell carcinoma of the larynx associated with leukocytosis and hypercalcemia, without bone metastasis. The serum granulocyte colony-stimulating factor (G-CSF) level was 222 pg/ml (normal, < 38 pg/ml), and decreased to 15 pg/ml after surgery. The serum parathyroid hormone-related protein (PTHrP) level was 5.6 pmol/l (normal, < 0.5 pmol/l), and this also decreased, to less than 0.5 pmol/l. G-CSF and PTHrP increased again with tumor recurrence. The production of G-CSF from the tumor was confirmed by immunohistochemical staining with monoclonal antibody against human recombinant G-CSF. The tumor was revealed to produce both G-CSF and PTHrP. In this article, we describe this very rare case of primary squamous cell carcinoma of the head and neck with the simultaneous ectopic production of more than one hormone-like substance.

Aged↗
PubMed2005

Aggressive syringomatous carcinoma of the orbit.

A 68-year-old woman with an unusual tumor involving the right orbit presented with painful exophthalmos of the right eye. Excision biopsy of her right eyelid was performed. The specimen showed ductal differentiation with comma-like extensions identical to syringoma. Cellular atypia, an invasive growth pattern, and remarkable perineural invasion led to the diagnosis of syringomatous carcinoma. Magnetic resonance imaging showed that the tumor exhibited maxillary involvement, invading the supraorbital fissure and bone of the middle skull base. The patient underwent craniofacial resection and has been alive with no sign of recurrence for 2 years. This case suggests that wide excision of these tumors with a clear surgical margin using skull base surgical techniques may offer a good prognosis.

Case Reports↗
PubMed2005

Adenovirus-mediated gene transfer in olfactory epithelium and olfactory bulb: a long-term study.

OBJECTIVES: We sought to study the spatiotemporal gene expression mediated by adenoviral vector in the olfactory pathways. METHODS: The replication-defective adenoviral vector AxCALacZ, which encodes the enzyme Escherichia coli beta-galactosidase, was applied to mouse olfactory epithelium by intranasal instillation. RESULTS: The LacZ gene product, beta-galactosidase, was expressed not only in the olfactory receptor neurons and their axons, but also in the olfactory bulbs. The first evidence of anterograde labeling was observed at postinfection day (PID) 2. At PID 3, beta-galactosidase was strongly expressed in olfactory nerve axons, as well as their terminal glomeruli, in the olfactory bulbs. beta-Galactosidase expression persisted up to PID 90, and there was a significant decrease in the number of labeled neurons at PID 30. CONCLUSIONS: These results suggest possible long-term effects of adenovirus-mediated gene transfer on the olfactory neurons, as well as the olfactory bulbs.

Adenoviridae↗
PubMed2005

Impact of antibiotics on pathogens associated with otitis media with effusion.

OBJECTIVE: To further understand the roles of bacteria and antibiotics in the development of otitis media with effusion (OME). METHODS: Samples of middle-ear effusion (MEE) were collected during the placement of ventilation tubes to treat chronic OME. Children with acute otitis media within the past three months were excluded from this study. We used polymerase chain reaction (PCR) to detect pathogens and to test the susceptibility of Streptococcus pneumoniae to penicillin. RESULTS: Among MEE samples from 52 children, PCR detected bacterial DNA in 32 per cent (24/75) of them. S. pneumoniae was detected more frequently in middle ears that required ventilation tube insertion at least twice compared with those requiring ventilation tube insertion only once (5/15 versus 4/60; p = 0.013). Higher levels of S. pneumoniae were detected in MEE from children with, than without, a long history of antibiotic administration (7/10 versus 2/14; p = 0.0187). The pbp genes of all isolated S. pneumoniae contained mutations. CONCLUSIONS: Long exposure to antibiotics might significantly influence the bacterial genome in MEE.

Anti-Bacterial Agents↗
PubMed2004

RET/PTC fusion gene rearrangements in Japanese thyroid carcinomas.

The activation of RET proto-oncogene through chromosomal translocation is reported as being unique to papillary thyroid carcinomas. However, the reported prevalence of RET/PTC activation in papillary carcinoma was variable, and the clinical relevance of RET/PTC rearrangements in papillary carcinomas is still controversial. To investigate the roles of RET rearrangement in the carcinogenesis of papillary thyroid carcinoma, we have studied RET activation and p53 overexpression in various thyroid lesions of the Japanese population by immunohistochemical technique. RET activation and p53 overexpression were studied in 40 papillary carcinomas, 6 poorly differentiated carcinomas, 4 undifferentiated carcinomas, 2 medullary carcinomas, 2 follicular carcinomas and 19 follicular adenomas. RET activation was observed in 12 out of 40 papillary carcinomas, while no immunoreactivity of RET was detected in other lesions. P53 overexpression was observed in only 1 of 40 papillary carcinomas, but in 2 poorly differentiated carcinomas and 4 undifferentiated carcinomas. The prevalence of RET/PTC activation in papillary carcinoma among the Japanese population was higher than in previous reports. Immunohistochemical technique is proved to be a useful tool to detect RFT/PTC activation in thyroid tumors. RET rearrangements are restricted to a well-differentiated papillary carcinoma, suggesting that RET/PTC positive papillary carcinomas do not progress to undifferentiated carcinoma.

Adenoma↗
PubMed2004

Notch expression in developing olfactory neuroepithelium.

Notch genes encode receptors for signaling pathways that regulate neurogenesis in various tissues. To better understand the roles of Notch genes in olfactory neurogenesis, we studied the expression of Notch family in developing mouse olfactory epithelium. In the earliest stage of olfactory development, Notch1 was observed in the mesenchyme lateral to the olfactory placode. During the developmental stage, Notch1 was mainly observed around the basal membrane, while Notch3 was observed in the lower compartment of the olfactory neuroepithelium. Notch2 was not detected during the entire observation period. As the olfactory neuroepithelium grew mature, both Notch1 and Notch3 gradually disappeared. These results suggest distinct roles of Notch1 and Notch3 in the neurogenesis of the peripheral olfactory system.

Animals↗
PubMed2004

A novel mitochondrial mutation, 1556C --> T, in a Japanese patient with streptomycin-induced tinnitus.

OBJECTIVE: Aminoglycoside antibiotics are associated with ototoxicity. The 1555A --> G mutation in the 12S ribosomal RNA gene of mitochondrial DNA has been considered to be associated with susceptibility to aminoglycoside antibiotics. In this study we examined a 79-year-old Japanese patient with a 45-year history of streptomycin-induced tinnitus in an attempt to find a mitochondrial mutation. MATERIALS AND METHODS: DNA was extracted from the patient's leukocytes. Polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) screening for the 1555A --> G mutation was done in order to detect a mitochondrial mutation and then nucleotide sequencing analysis was performed to identify the mutation. RESULTS: PCR-RFLP screening detected the presence of a mitochondrial mutation in the patient. However, the nucleotide sequencing analysis showed that the mutation was not the 1555A --> G mutation but a novel mutation, 1556C --> T. The mutation was not found in 112 unrelated Japanese control subjects, suggesting that the mutation was specific to our patient. CONCLUSIONS: The 1556C --> T mutation may be a genetic risk factor for aminoglycoside-induced hearing impairment. Our result also suggests that patients with the 1556C --> T mutation exist among those expected to have the 1555A --> G mutation as a result of PCR-RFLP analysis.

Aged↗
PubMed2004

Quantitative analysis of expression of NeuroD, GAP43 and receptor tyrosine kinase B in developing mouse olfactory neuroepithelium.

OBJECTIVE: The mammalian olfactory neuroepithelium (OE), which harbors olfactory receptor neurons (ORNs), has the unusual characteristic of continuous neurogenesis throughout its lifetime. This unique feature provides an excellent model for neuronal differentiation. Recently, we found dual-phase expression of NeuroD, a member of the basic helix-loop-helix transcription factor family, in the developing mouse OE, suggesting multiple roles of NeuroD during the development of mammalian ORNs. MATERIAL AND METHODS: In order to better understand the molecular mechanism of the development of ORNs, we performed quantitative analysis of expression of NeuroD, GAP43 and receptor tyrosine kinase B (TrkB), as well as 5-bromo-2'-deoxyuridine (BrdU)-labeled cells, in the developing mouse OE from gestational Day 10 to postnatal Day 28. RESULTS: During the embryonic period, NeuroD expression is mostly confined to the basal compartment. During the neonatal period, NeuroD expression is detected in two compartments: the middle compartment and the basal compartment. GAP43-expressing cells were located between these two NeuroD-positive layers. TrkB-expressing cells were located above the NeuroD-positive layer in the middle compartment. As the mice grew, the numbers of NeuroD-expressing cells and BrdU-labeled cells in the basal compartment significantly decreased, while the number of NeuroD-expressing cells in the middle compartment gradually increased. The number of TrkB-expressing cells dramatically increased. The number of GAP43-expressing cells also gradually increased. However, the relative proportion of GAP43 cells decreased as the OE developed. CONCLUSION: NeuroD is a useful molecular marker for studying olfactory neurogenesis.

Animals↗
PubMed2004

Synovial sarcoma of the neck.

BACKGROUND: Synovial sarcoma is a soft tissue sarcoma rarely seen in the head and neck. Due to its rarity and morphologic variations, diagnosis is difficult in most cases. METHOD: A case of synovial sarcoma arising in the upper neck is presented. The detection of the specific chromosomal translocation t(X;18)(p11.2;q11.2) is also described. RESULT: A specific chimeric gene, the SSX-SYT fusion gene, was identified in the formalin-fixed paraffin-embedded surgical specimen using the reverse-transcription polymerase chain reaction (RT-PCR) technique. CONCLUSION: Synovial sarcoma contains a characteristic chromosomal translocation, which serves as a useful diagnostic tool. RT-PCR technique has enabled to detect this specific translocation not only in fresh tissues but also in archival paraffin-embedded specimens.

Adult↗