Pre- and postsynaptic ATP-sensitive potassium channels during metabolic inhibition of rat hippocampal CA1 neurons

Presynaptic and postsynaptic membrane activities during experimental metabolic inhibition were analysed in mechanically dissociated rat hippocampal neurons using nystatin-perforated and conventional whole-cell patch clamp recordings. NaCN, an inhibitor of mitochondrial ATP synthesis, induced an outward current across the postsynaptic soma membrane. This current was blocked by tolbutamide, a sulfonylurea, which blocks ATP-sensitive K+ (KATP) channels. The presynaptic effect of metabolic inhibitors such as NaCN, NaN3, or glucose-free solution was to increase the frequency of GABAergic miniature inhibitory postsynaptic currents (mIPSCs). Tolbutamide had no effect on this increase in mIPSC frequency induced by metabolic inhibition. Diazoxide, a KATP channel opener, evoked a similar somatic outward current in a dose-dependent manner. In addition, diazoxide decreased the frequency of mIPSCs in a dose-dependent fashion. Both these pre- and postsynaptic effects of diazoxide were reversed by tolbutamide, suggesting the existence of KATP channels on both pre- and postsynaptic membranes. These results confirm the presence of KATP channels on both the pre- and postsynaptic membranes but indicate that the channels have significantly different sensitivities to metabolic inhibition.

[Analysis of the regulatory mechanism of the rat cerebellum on the motor coordination in the time and space domain]

To elucidate the mechanism of the cerebellum on the regulation of coordinated movement in time and space domain, ninety-six Purkinje cell complex spike was simultaneously recorded utilizing ninety-six glass micro pipette electrodes. The complex activity of the bilateral cerebellum was symmetrically synchronized. Furthermore, the medial cells fired first, then the lateral cells fired succeedingly. These results suggest that the time domain of the motor coordination was regulated by the symmetrical firing pattern of the bilateral cerebellum Purkinje cell activity.

Laminin gamma 1 chain peptide, C-16 (KAFDITYVRLKF), promotes migration, MMP-9 secretion, and pulmonary metastasis of B16-F10 mouse melanoma cells

Laminin-1, a heterotrimer of alpha 1, beta 1, and gamma 1 chains specific to basement membrane, promotes cell adhesion and migration, proteinase secretion and metastases of tumour cells. Several active sites on the alpha 1 chain have been found to promote B16-F10 melanoma lung colonisation and here we have determined whether additional tumour promoting sites exist on the beta 1 and gamma 1 chains. Recently, we have identified novel cell adhesive peptides derived from laminin beta 1 and gamma 1 chains by systematic screening of synthetic peptides. Nine beta 1 peptides and seven gamma 1 peptides active for cell adhesion were tested for their effects on experimental pulmonary metastases of B16-F10 mouse melanoma cells in vivo. The most active adhesive peptide derived from the gamma 1 chain globular domain, C-16 (KAFDITYVRLKF), significantly enhanced pulmonary metastases of B16-F10 cells, whereas no other peptides showed enhancement. C-16 also stimulated migration of B16-F10 cells in the Boyden chamber assay in vitro. Furthermore, C-16 significantly induced the production of MMP-9 from B16-F10 cells. These results suggest that this specific laminin gamma 1 chain peptide has a metastasis-promoting activity and might be a new molecular target of anti-cancer treatment.

Taste dysfunction in irradiated patients with head and neck cancer

Taste disorders caused by radiation therapy for head and neck cancer are common. This prospective study of 40 patients with head and neck cancer assessed changes in taste sensations during radiation therapy. The relationship between the time course and the degree of taste disorder was studied. The taste recognition threshold and supra-threshold taste intensity performance for the four basic tastes were measured using the whole-mouth taste method before, during, and after radiation therapy. Bitter taste was affected most. An increase in threshold for sweet taste depended upon whether the tip of tongue was included within the radiation field. The slope of the taste intensity performance did not change during or after radiotherapy. The pattern of salivary dysfunction was different from that of taste dysfunction. The main cause of taste disorders during radiation support the hypothesis that taste dysfunction is due to damage to the taste buds in the radiation field.

The roles of JNK1 and Stat3 in the response of head and neck cancer cell lines to combined treatment with all-trans-retinoic acid and 5-fluorouracil

We have used a combination of vitamin A (all-trans-retinyl palmitate), 5-fluorouracil (5-FU) and radiation to treat human head and neck squamous cell carcinoma (HNSCC). This chemoradiotherapy is called "FAR therapy." In this study we examined the effects of all-trans-retinoic acid (ATRA), the active metabolite of vitamin A, and ATRA plus 5-FU on two HNSCC cell lines (YCU-N861 and YCU-H891) to gain insight into the molecular mechanisms of FAR therapy. ATRA at 1 mM (the order of concentration found in HNSCC tumors treated with FAR therapy) inhibited cell proliferation and caused G1 cell cycle arrest in both cell lines. This was associated with a decrease in cyclin D1, an increase in p27(Kip1) and a reduction in the hyperphosphorylated form of retinoblastoma protein (pRB). With YCU-N861 cells, ATRA also caused a decrease in Bcl-2 and Bcl-X(L) and an increase in Bax. Both ATRA and 5-FU activated c-Jun N-terminal kinase (JNK) 1 and the combination of both agents resulted in additive or synergistic activation of JNK1, and also enhanced the induction of apoptosis. The YCU-H891 cells, in which the epidermal growth factor receptor (EGFR)-signal transducer and activator of transcription 3 (Stat3) pathway is constitutively activated, were more resistant to treatments with ATRA, 5-FU and the combination of both agents than YCU-N861 cells. A dominant negative Stat3 construct strongly enhanced the cellular sensitivity of this cell line to 5-FU but not to ATRA. In addition there is evidence that activation of Stat3 is associated with cellular resistance to radiation in HNSCC. Therefore, the addition to FAR therapy of agents that inhibit activation of the Stat3 pathway may enhance the clinical response of patients with HNSCC to FAR therapy.

Mutation analysis of human cytokeratin 8 gene in malignant rhabdoid tumor: a possible association with intracytoplasmic inclusion body formation

The rhabdoid cell, which is typically observed in malignant rhabdoid tumor (MRT) and other malignant neoplasms, has an eosinophilic cytoplasm containing a spheroid perinuclear inclusion body. This distinct cell is known to act as a highly aggressive indicator in many types of malignant tumors and is characterized by aggregates of intermediate filaments, comprising both vimentin and cytokeratin (CK) 8, which is mainly expressed in simple-type epithelium such as liver and intestine. To clarify the cause of the inclusion body formation, we analyzed the alteration of the complete human CK8 gene (KRT 8: 1724 base pairs) in seven samples of MRT (three from frozen materials and four from cultured cell lines) by reverse-transcriptase polymerase chain reaction, followed by direct sequencing. In addition, the two cell lines, Huh7 and HeLa, which lacked rhabdoid feature, six pediatric malignant tumors, including three cases of primitive neuroectodermal tumor (PNET) and three of Wilms' tumor; and 15 normal liver tissue (as a control) were also analyzed. All MRT samples had missense mutations in the human KRT 8 gene, i.e., Arg89 --> Cys (5/7); Arg --> Cys251 (3/7); Glu267 --> Lys (6/7); Ser290 --> Ile, Met; (7/7) and Arg301 --> His(4/7), none of which was detected in any control samples. Among these mutations, the most noteworthy findings were that Arg89 belongs to the H1 subdomain of the head domain and that Arg251 belongs to the short nonhelical linker segment, or L1-2. Both these mutations are noted for their relationships to lateral protofilament-protofilament interactions. In addition, Ser290 has been previously reported to be a phosphorylation site, which has been recognized to play an important role in filament organization, leading to conformational change of the CK8 filaments. In conclusion, mutated codons of CK8 gene in MRT were located in the important region involved in the conformational change of intermediate filament.

Thrombectomy and SVC reconstruction due to infective thrombus

We report a case of thrombectomy and reconstruction of superior vena cava (SVC) in a patient presenting sepsis and SVC syndrome by infective thrombus. A 58-year-old woman presented sepsis and edema of the neck and left upper extremity during treatment of multiple organ failure. Sepsis by Serratia persisted in spite of appropriate antibiotic treatment. Computed tomography of the chest revealed thrombi that narrowed the SVC with obstruction of the left brachiocephalic vein. Removal of the infective thrombi followed by SVC reconstruction with autologous pericardial patch was performed. Postoperative period remained uneventful.

Serum squamous cell carcinoma antigen is a useful biologic marker in patients with inverted papillomas of the sinonasal tract

BACKGROUND

Inverted papilloma (IP) is a frequent benign sinonasal tumor that is characterized histologically by squamous metaplasia, epithelial acanthosis, and hyperplasia of the nasal epithelium. Because of its high recurrence rate and malignant transformation potential, careful long-term follow up is necessary.

METHODS

The purpose of the current report was to study the expression of squamous cell carcinoma (SCC) antigen in sinonasal IPs and to evaluate the usefulness of SCC antigen as a biologic marker for the follow-up of patients with sinonasal IP. The expression of SCCA1 in three sinonasal IP cases, three sinonasal SCC cases, and cases of normal nasal epithelium were examined by Western blot analysis, and the SCCA1 expression pattern in 31 IP specimens and 4 carcinoma in IP specimens were evaluated immunohistochemically. The serum levels of SCC antigen in 11 patients with sinonasal IP also were analyzed.

RESULTS

SCCA1 was overexpressed in all three sinonasal IP tissues compared with sinonasal SCC tissues or normal nasal epithelium. SCCA1 cytoplasmic immunoreactivity was detected in the suprabasal epidermal keratinocytes of all 31 sinonasal IP cases. In the four carcinoma in IP specimens, SCCA1 expression in the papillomatous lesion was more intense than in the cancerous lesion. The serum SCC antigen level was high in 10 of 11 patients with IP (91%) and significantly decreased after surgical resection of the tumors.

CONCLUSIONS

The results of the current study indicate that SCCA1 frequently is overexpressed and may play a biologic role in the development of sinonasal IPs. Serum SCC antigen may be a useful biologic marker in patients with sinonasal IP.

Tumor imprint cytology of ovarian ependymoma. A case report

BACKGROUND

Ependymoma is a tumor that usually develops in the central nervous system and is extremely rare in the ovary. The first case of ovarian ependymoma was reported by Kleinman et al. (Kleinman GM, Young RH, Scully RE. Ependymoma of the ovary: report of three cases. Hum Pathol 1984;15:632-8.) in 1984, and only eight cases have been reported since then. Criteria for the histopathologic diagnosis of ependymoma are already established, but there has been no investigation of the cytologic diagnosis of ovarian ependymoma.

METHODS

An imprint cytologic specimen was obtained from a recurrent ovarian ependymoma. The imprint cytologic features were compared with the findings of histologic examination, immunostaining, and electron microscopy.

RESULTS

Imprint cytology revealed clusters of small cells with tapering cytoplasmic processes and a round nucleus. On the basis of these features, a neurogenic tumor could be included in the differential diagnosis. Furthermore, many rosette-like collections of cells that were suggestive of ependymal rosettes or perivascular pseudorosettes, characteristic of ependymoma, were found. The presence of ependymal rosettes and perivascular pseudorosettes also were confirmed by the histopathologic examination. Together with positive immunostaining for glial fibrillary acidic protein, this led to the diagnosis of ependymoma, which also was supported by the electron microscopic findings.

CONCLUSIONS

Careful observation of the imprint cytologic specimen of an ovarian ependymoma should reveal numerous rosette-like collections of cells that were suggestive of ependymal rosettes or perivascular pseudorosettes. In addition, if we remember that ependymoma can develop in the ovary and find cells with tapering processes that suggest a neurogenic tumor, it may be possible to detect histologic features characteristic of ependymoma by the imprint cytology. To our knowledge, this is the first report on the imprint cytologic diagnosis of ependymoma originating in the ovary.

Maspin expression in stage I and II oral tongue squamous cell carcinoma

BACKGROUND

A relatively high failure rate in the therapy of patients with early oral tongue squamous cell carcinomas (SCCs) is evidenced by untreated clinically negative neck lymph node metastasis. It is important to predict the malignant potential of oral tongue SCC in stage I and II patients, because the development of lymph node metastasis directly affects the prognosis of the patients.

METHODS

We evaluated maspin expression immunohistochemically in patients with stage I and II oral tongue SCCs and determined whether the expression level may be a useful factor in predicting metastatic potential and prognosis of these SCCs.

RESULTS

Clinical follow-up data showed a longer disease-free interval and overall survival periods for tumors immunohistochemically positive for maspin than for tumors negative for maspin, with the difference in disease-free interval being statistically significant (p =.01). The absence of maspin expression was found more frequently in cases of subsequent cervical lymph node metastasis than in cases without metastasis (p =.03).

CONCLUSIONS

Decreased maspin expression may be a significant factor associated with the metastatic potential of stage I and II oral tongue SCCs.

Primary ependymoma of the ovary, in which long-term oral etoposide (VP-16) was effective in prolonging disease-free survival

BACKGROUND

Ovarian ependymoma is an extremely unusual teratoma of the ovary with only eight cases previously reported in the literature worldwide.

CASE

A 26-year-old woman presented in 1992 with a sensation of abdominal fullness. The laparotomy revealed ovarian cancer (stage III), which proved to be an ependymoma pathologically. Three courses of the PVP regimen (cisplatin, vinblastine, peplomycin) and pelvic irradiation were administered postoperatively. Oral administration of etoposide (VP-16) was initiated after the residual tumor began to proliferate, and the tumor decreased in size and never regrew during etoposide administration for a total of 5 years and 8 months. The recurrent tumor was observed soon after the drug was discontinued.

CONCLUSION

Oral administration of etoposide was effective in prolonging disease-free survival.

Case report of serous ovarian tumor of borderline malignancy (Stage Ic) in a pregnant woman

We encountered a case of Stage Ic ovarian serous borderline malignancy in the first trimester of pregnancy. At laparotomy, spontaneous rupture of the capsule and a small amount of serous ascites was observed. Because of the laparotomy during pregnancy, correct staging of the tumor might not be performed. This case presented a major problem in deciding the treatment strategy, which are reported here together with some discussion of the literature on the preservation of fertility in borderline ovarian malignancy.

All-trans-retinoic acid enhances the effect of adenovirus-mediated wild-type p53 gene transfer in head and neck squamous cell carcinoma

OBJECTIVES

Adenovirus-mediated p53 (AdCMVp53) gene therapy for cancer is currently undergoing phase III clinical trials. One problematic aspect of this therapy is that the current protocols result in low transduction of the therapeutic virus in vivo. To search new modalities that can enhance the effect of AdCMVp53 gene therapy, we focused on retinoids.

METHODS

To study the effect of ATRA in combination with AdCMVp53 gene therapy, we pretreated head and neck squamous cell carcinoma (HNSCC) cells for 72 hours with a low-dose All-trans-retinoic acid (ATRA) (10-7 M-10-8 M) which will not affect the in vitro cell growth, and then infected the cells with low MOI (30MOI) AdCMVp53. In vitro cell proliferation assays, cell cycle assays were performed. Expression of p53 and p53-related gene products, BAX and p21, were examined.

RESULTS

The combined treatment with ATRA and Ad-p53 suppressed cell growth and induced apoptosis significantly more than AdCMVp53 treatment alone (P <.05). p53 expression significantly increased more after the combined treatment than after either treatment alone, at both the transcription and protein levels. In addition, increased expression of p21 and BAX, which are downstream gene products of p53, was observed in the combination. ATRA also enhanced the expression of green fluorescent protein (GFP) transduced by an adenovirus-cytomegalovirus (CMV)-GFP vector suggesting ATRA enhances adenovirus-CMV-promoted vectors through transcription.

CONCLUSIONS

Our results indicate that ATRA enhances AdCMVp53 expression through transcriptional mechanisms and can synergistically induce apoptosis in HNSCC cells. ATRA has a potential to enhance the effect of adenovirus-mediated p53 gene therapy for HNSCC.

SCCA1 expression in T-lymphocytes peripheral to cancer cells is associated with the elevation of serum SCC antigen in squamous cell carcinoma of the tongue

Squamous cell carcinoma (SCC) antigen has been used for the management of SCC arising in various cites including head and neck region. However, the true mechanism of the elevation of this protein in the serum of patients with SCC is still unknown. SCC antigen belongs to the superfamily of serine protease inhibitors. Recently, molecular studies show that serum SCC antigen is transcribed by two nearly identical genes (SCCA1 and SCCA2), and is mainly produced by SCCA1. The objective of this study is to clarify the mechanism of the elevation of SCC antigen in oral tongue SCC patients and to identify cells histologically, which are responsible for serum SCC antigen production. In this study, we examined SCCA1 expression in a series of four head and neck SCC (HNSCC) cell lines, and found that all expressed equal to low SCCA1 protein as compared with the normal human oral keratinocyte. Using the double immunohistochemical technique to examine the expression pattern of SCCA1 in 86 cases of oral tongue squamous cell carcinoma, SCCA1 immunostaining was observed in the cytoplasm of cancer cells and T-lymphocytes peripheral to cancer cells. We also compared the clinicopathological features including serum SCC antigen level of the oral tongue SCC cases with the immunohistochemical SCCA1 expression pattern, and found that elevated serum SCC antigen level was significantly correlated with SCCA1 expression not in cancer cells, but in T-lymphocytes peripheral to cancer cells. These results suggest that T-lymphocytes peripheral to cancer cells may be responsible for serum SCC antigen production in HNSCC patients.

Immunohistochemical observation of actin filaments in epithelial cells encircling the taste pore cavity of rat fungiform papillae

Epithelial cells are connected to each other around taste pores in rat fungiform papillae. Cytoskeletal components are responsible for the maintenance of intracellular adhesion, and we investigated the identification and localization of actin filaments around taste pores. On the basis of observations made by immunohistochemical transmission electron microscopy comparing with confocal laser scanning microscopy using actin-lectin double staining, actin filaments were found to be localized, encircling the squeezed taste pore cavity, in epithelial cells a few micrometers below the papilla surface. In addition, these observations suggest that the organization of actin filaments around taste pores might be involved in the constriction of taste pores.

Cytokeratin subunits of inclusion bodies in rhabdoid cells: immunohistochemical and clinicopathological study of malignant rhabdoid tumor and epithelioid sarcoma

Extrarenal malignant rhabdoid tumor (MRT), which is recognized as being histologically similar to renal MRT, is characterized by the presence of "rhabdoid cell" (RC) and a highly aggressive biological behavior. Recently it has been proposed that "proximal variant" of epithelioid sarcoma (ES), whose morphology is similar to that of MRT, actually has a more aggressive clinical course than classical type ES. Detailed immunohistochemical analysis of cytokeratin (CK) subunits was performed in 3 cases of extrarenal MRT, 3 cases of renal MRT, and 11 cases of ES comprising 2 "proximal variants" and 9 classical types. Renal and extrarenal MRTs showed positive immunoreactivity for both CK8 and CK18. Classical type ESs were diffusely positive, not only for CK8 and CK18, but also for other cytokeratin subunits including CK4, 6, 10, 13, 16, 17, and "high-molecular-weight" CKs (CK1, 5, 10, and 14). On the other hand, proximal ES revealed limited immunohistochemical reactivity for cytokeratins, compared with classical ES. In conclusion, the inclusion bodies of RCs show immunoreactivity confined to CK8, CK18, and vimentin. Furthermore, ES has additional CK expressions, while proximal ES possesses characteristics intermediate between those of classical ES and those of external MRT.

Decreased CD44H expression in early-stage tongue carcinoma associates with late nodal metastases following interstitial brachytherapy

BACKGROUND

Late nodal metastases is a critical factor that worsens the prognosis of T1/T2N0 tongue cancer treated by interstitial brachytherapy. If we could better predict the patients at high risk for late nodal metastases developing before treatment, more appropriate choices of treatment could be selected. In recent studies of colon cancer, prostate cancer, and laryngeal cancer, CD44H has been postulated to be a metastasis suppressor.

METHODS

On the basis of this phenomenon, we immunohistochemically evaluated the expression of CD44H in 38 cases of primary T1/T2N0 tongue cancer treated by interstitial brachytherapy. Formalin-fixed, paraffin-embedded biopsy specimens obtained before treatment were examined.

RESULTS

The group that had late nodal metastases revealed a significantly lower (p =.0035) CD44H expression.

CONCLUSIONS

A decreased CD44H expression may therefore be useful as a new predictor of late nodal metastases in patients with T1/T2N0 tongue carcinoma. For patients with a decreased CD44H expression, a partial glossectomy and an elective neck dissection may therefore be an appropriate treatment modality.

A subunit of the mammalian oligosaccharyltransferase, DAD1, interacts with Mcl-1, one of the bcl-2 protein family

DAD1 is a mammalian homologue of Saccharomyces cerevisiae Ost2p, a subunit of the oligosaccharyltransferase complex. Loss of its function induces apoptosis in hamster BHK21 cells. By means of a two-hybrid method involving DAD1 as bait, the C-terminal region of Mcl-1, one of the bcl-2 family, was isolated. Consistently, DAD1 binds well to Mcl-1 in COS cells when overexpressed. On deletion analysis, the C-terminal domain of Mcl-1 containing BH(2) (bcl-2 homologous domain) was found to be essential for the interaction with DAD1. On the other hand, the C-terminal half of DAD1 was concluded to be essential for the interaction with Mcl-1. Surprisingly, a DeltaC-DAD1 mutant lacking only 4 amino acid residues from the C-terminus did not complement the tsBN7 mutation, while it interacted well with Mcl-1. In contrast, DeltaN-DAD1 lacking 20 amino acid residues from the N-terminus still exhibited the ability to complement the tsBN7 mutation. Thus, the C-terminus of DAD1 was suggested to play an important role in N-linked glycosylation and to complement the tsBN7 mutation. Mcl-1 may be required for the inhibition of apoptotic cell death caused by a loss of DAD1.

[Respiratory function after coronary artery bypass grafting through mini-sternotomy as a factor of early recovery]

OBJECTIVES

Early recovery in patients after minimally invasive coronary artery bypass grafting with mini-sternotomy and cardiopulmonary bypass (MICS-CABG) was compared to standard CABG by assessing preoperative and postoperative (7 to 10 days after) respiratory function.

METHODS

Fifteen patients (Group M; mean age 62.1 years) underwent MICS-CABG with a mean of 2.3 distal anastomoses per patient. Ten patients (Group F; mean age 63.8 years) underwent standard CABG through full sternotomy with a mean of 2.4 distal anastomoses per patient.

RESULTS

Postoperative coronary angiography showed that the patency rate of the grafts was 97% in Group M and 96% in Group F. Intubation time and hospital stay were significantly shorter (p < 0.01) in Group M (6.2 +/- 2.4 hours, 16.3 +/- 3.1 days) than in Group F (10.8 +/- 2.9 hours, 22.8 +/- 2.5 days). Respiratory function measured as the percentage of postoperative to preoperative values (Group M/Group F; mean +/- standard error) were vital capacity of 95.8 +/- 3.1%/74.6 +/- 3.4% (p < 0.05), 1 sec percentage of forced expiratory volume of 98.8 +/- 2.3%/71.8 +/- 2.8% (p < 0.05) and peak expiratory flow rate of 91.7 +/- 4.2%/89.4 +/- 4.5%.

CONCLUSIONS

Quick recovery of the respiratory function after MICS-CABG may be important in the early recovery and short hospital stay of MICS-CABG patients compared with standard CABG patients.

Predominant role of the chorda tympani nerve in the maintenance of the taste pores: the influence of gustatory denervation in ear surgery

The effect on the taste pores of denervation of the chorda tympani nerve in the middle-ear cavity was studied comparing confocal laser microscopy with lingual nerve resection. Taste pore cells were stained for actin with rhodamine-phalloidin and positive fluorescence was observed as a ring shape at the transverse cross sections. Within three days after chorda tympani nerve resection the ring reaction disappeared, although the pore morphology remained intact as seen by scanning electron microscopy. On the other hand, lingual nerve resection did not induce such rapid disappearance of the ring reaction. These results suggest that the chorda tympani nerve plays a predominant role in the maintenance of actin filaments in taste pore cells.

Prevalence of mitochondrial gene mutations among hearing impaired patients

The frequency of three mitochondrial point mutations, 1555A-->G, 3243A-->G, and 7445A-->G, known to be associated with hearing impairment, was examined using restriction fragment length polymorphism (RFLP) analysis in two Japanese groups: (1) 319 unrelated SNHL outpatients (including 21 with aminoglycoside antibiotic injection history), and (2) 140 cochlear implantation patients (including 22 with aminoglycoside induced hearing loss). Approximately 3% of the outpatients and 10% of the cochlear implantation patients had the 1555A-->G mutation. The frequency was higher in the patients with a history of aminoglycoside injection (outpatient group 33%, cochlear implantation group 59%). One outpatient (0.314%) had the 3243A-->G mutation, but no outpatients had the 7445A-->G mutation and neither were found in the cochlear implantation group. The significance of the 1555A-->G mutation, the most prevalent mitochondrial mutation found in this study of a hearing impaired population in Japan, among subjects with specific backgrounds, such as aminoglycoside induced hearing loss, is evident.

Evaluation of Epstein-Barr virus infection in sinonasal small round cell tumors

Sinonasal undifferentiated carcinoma, olfactory neuroblastoma and malignant melanoma of the sinonasal regions are included within the category of small round cell tumors of the sinonasal region. It is difficult to diagnose these tumors on the basis of light-microscopic features alone, but, in some instances, immunohistochemical staining evaluating cytokeratin and S-100 protein, for example, is of value. On the other hand, the sinonasal region is a significant site for Epstein-Barr-virus (EBV)-related tumors, including sinonasal undifferentiated carcinoma or malignant lymphoma. Twenty-three sinonasal small round cell tumors (SSRCT) comprising 5 sinonasal undifferentiated carcinomas, 9 olfactory neuroblastomas and 9 malignant melanomas were evaluated for the presence of EBV infection by in situ hybridization for EBV-encoded RNA, combined with immunostaining for EBV-related proteins (LMP-1 and EBNA2). Furthermore, 55 SSRCT comprising 37 sinonasal undifferentiated carcinomas, 9 olfactory neuroblastomas, and 9 malignant melanomas were examined for the presence of cytokeratins (AE1/ AE3 and CAM5.2), S-100 protein and p53 protein using immunohistochemical staining. According to in situ hybridization for detecting EBV-encoded RNA 1 (EBER1), all of the sinonasal undifferentiated carcinomas showed clear, intense hybridization signals localized over the nuclei of the tumor cells and, in 3 out of 9 (33.3%) malignant melanomas, hybridization signals were also recognized. However, none of the olfactory neuroblastomas revealed hybridization signals. Immunohistochemically, 4 out of 5 (80%) sinonasal undifferentiated carcinomas were positive for LMP-1, whereas only 2 out 9 (22.2%) malignant melanomas and no olfactory neuroblastomas were positive. With regard to EBNA2, sinonasal undifferentiated carcinomas, malignant melanomas and olfactory neuroblastomas were all negative. Out of 37 sinonasal undifferentiated carcinomas 35 (94.6%) showed a diffuse positive immunoreaction for AE1/AE3, whereas neither olfactory neuroblastoma nor malignant melanoma revealed a positive reaction. All 9 malignant melanomas and 6 out of 9 olfactory neuroblastomas (75%) were positive for S-100 protein, whereas only 6 cases of sinonasal undifferentiated carcinomas (19.4%) were positive. As for p53 protein, 16 of 37 sinonasal undifferentiated carcinomas (43.2%) were positive, whereas neither olfactory neuroblastoma nor malignant melanoma revealed any positive reaction. The above results suggest that EBV infection is closely associated with sinonasal undifferentiated carcinomas, and that some malignant melanomas may also have a relationship with its infection. For the differential diagnosis of SSRCT, it is important to evaluate EBV infection along with immunohistochemical staining for cytokeratins and S-100 protein. The overexpression of p53 protein was found to be related to the oncogenesis of sinonasal undifferentiated carcinoma; however, there was no association between its overexpression and malignant melanoma or olfactory neuroblastoma.

Superoxide anion impairs Ca(2+) mobilization in cultured human nasal epithelial cells

We examined the effects of superoxide anion (O(-2)) on the intracellular Ca(2+) concentration in cultured human nasal epithelial cells. The cells were exposed to O(-2) by pretreatment with xanthine (X) and xanthine oxidase (XO); control cells were treated with X alone. When Ca(2+)-containing Krebs solution was reperfused in the thapsigargin-treated, store-depleted cells, reapplication-induced intracellular Ca(2+) concentration elevation was significantly smaller in X/XO-treated cells than in the control cells, suggesting that O(-2) impairs Ca(2+) release-activated Ca(2+) entry (CRAC). Bath application of ATP induced a steep Ca(2+) transient in both control and X/XO-treated cells. However, the concentration-response curve of the ATP-induced Ca(2+) transient was shifted to a higher concentration in X/XO-treated cells. The impairments of CRAC and ATP-induced Ca(2+) transient induced by X/XO were reversed by superoxide dismutase. Furthermore, all these X/XO-induced effects were also observed in cells pretreated with pyrogallol, also an O(-2) donor. These results indicate that O(-2) impairs at least two mechanisms involved in Ca(2+) mobilization in human nasal epithelial cells, i.e., CRAC and ATP-induced Ca(2+) release.

Cases of cutaneous and nasal CD56 (NCAM)-positive lymphoma in Japan have differences in immunohistology, genotype, and etiology

CD56 (NCAM)-positive lymphoma frequently involves the skin and nasal area. This study shows it is likely that the clinicopathologic features of this lymphoma are distinctive to each of the primarily involved sites. Sixteen cutaneous and 11 nasal cases of CD56-positive lymphoma were examined. In 10 cutaneous cases, the lesions consisted of pleomorphic large-cell lymphoma that expressed CD3epsilon (CD3), CD2 (LFA2), CD4, CD122 (IL-2B receptor), TIA1, perforin, and granzyme B and displayed angiocentric/angiodestructive features. Lobular panniculitis was found in 8 of these cases, and 6 cases showed other organ involvement. The remaining 6 cutaneous cases consisted mostly of CD3epsilon- and CD4-positive, CD2-, CD122-, and TIA1-negative large blastic lymphoma, having less angiodestruction and panniculitis. Bone marrow invasion and leukemic changes were found in 4 of these cases during the clinical course. All 11 nasal cases showed pleomorphic small and medium-size lymphoma cells with angiodestructive features and were positive for CD3epsilon, CD2, CD122, TIA1, perforin, and granzyme B. CD4-positive lymphoma was found in 4 of these cases. Only 3 nasal cases showed other organ involvement. Genotypically, 2 of the 4 cases examined in the first cutaneous group, 3 of the 4 cases examined in the second cutaneous group, and only 1 of the 11 nasal cases showed rearrangement of the TcRCbeta gene by the Southern blot method. Only 2 cutaneous cases with panniculitis and all 11 nasal cases showed a positive nuclear signal for EBV-encoded RNA (EBERs) by in situ hybridization. Thus, two types of cutaneous CD56-positive lymphoma were found, each having a unique cell characteristic, genotype, and EBV infection pattern that differed from that of nasal-type lymphoma.