Synthesis of an azadioxa-planar triphenylborane and investigation of its structural and photophysical properties.

We report here the first successful synthesis of planar triphenylborane 1 with the phenyl groups bridged by oxygen and nitrogen atoms via double nucleophilic aromatic substitution reaction. The hetero atom-bridged 1 has excellent planarity. Its structural and photophysical properties are tunable by altering the bridging atoms.

Human mismatch repair gene, MLH1, is transcriptionally repressed by the hypoxia-inducible transcription factors, DEC1 and DEC2.

Tumor hypoxia has been reported to cause a functional loss in DNA mismatch repair (MMR) system as a result of downregulation of MMR genes, although the precise molecular mechanisms remain unclear. In this study, we focused on the downregulation of a key MMR gene, MLH1, and demonstrated that hypoxia-inducible transcription repressors, differentiated embryo chondrocytes (DEC1 and 2), participated in its transcriptional regulation via their bindings to E-box-like motif(s) in MLH1 promoter region. In all cancer cell lines examined, hypoxia increased expression of DEC1 and 2, known as hypoxia-inducible genes, but decreased MLH1 expression in an exposure time-dependent manner at both the mRNA and protein levels. Co-transfection reporter assay revealed that DEC1 and, to greater extent, DEC2 as well as hypoxia-repressed MLH1 promoter activity. We further found that the action was remarkably inhibited by trichostatin A, and identified a possible DEC-response element in the MLH1 promoter. In vitro electrophoretic gel mobility shift and chromatin immunoprecipitation assays demonstrated that DEC1 or 2 directly bounds to the suggested element, and transient transfection assay revealed that overexpression of DEC2 repressed endogenous MLH1 expression in the cells. Hypoxia-induced DEC may impair MMR function through repression of MLH1 expression, possibly via the histone deacethylase-mediated mechanism in cancer cells.

Multi-finger structure and pulsed-powering operation scheme for CMOS LSI-based flexible stimulator for retinal prosthesis.

Multi-finger structure was proposed to improve flexibility of the CMOS LSI-based multi-chip retinal stimulator. A dual-finger retinal stimulator was fabricated and its functionality was demonstrated in retinal stimulation experiments on rabbit's retina, We also proposed an idea of pulsed-powering operation scheme for the multi-chip flexible retinal stimulator. We compared the pulsed-powering scheme with conventional one in a simulation, and show that the pulsed-powering can be an alternative operation scheme for the neural stimulator that provides an improved safety to the biological tissue.

Telomere and telomerase in stem cells.

Telomeres, guanine-rich tandem DNA repeats of the chromosomal end, provide chromosomal stability, and cellular replication causes their loss. In somatic cells, the activity of telomerase, a reverse transcriptase that can elongate telomeric repeats, is usually diminished after birth so that the telomere length is gradually shortened with cell divisions, and triggers cellular senescence. In embryonic stem cells, telomerase is activated and maintains telomere length and cellular immortality; however, the level of telomerase activity is low or absent in the majority of stem cells regardless of their proliferative capacity. Thus, even in stem cells, except for embryonal stem cells and cancer stem cells, telomere shortening occurs during replicative ageing, possibly at a slower rate than that in normal somatic cells. Recently, the importance of telomere maintenance in human stem cells has been highlighted by studies on dyskeratosis congenital, which is a genetic disorder in the human telomerase component. The regulation of telomere length and telomerase activity is a complex and dynamic process that is tightly linked to cell cycle regulation in human stem cells. Here we review the role of telomeres and telomerase in the function and capacity of the human stem cells.

Biological characteristics of neuroblastoma with partial deletion in the short arm of chromosome 1.

BACKGROUND: Neuroblastoma shows remarkable heterogeneity, resulting in favorable and unfavorable outcomes. It is well known that almost all cases with MYCN amplification have a poor prognosis. We have previously reported that unfavorable tumors show high telomerase activity, whereas favorable tumors show low or nil activity. We also found that the unfavorable neuroblastoma often have a loss of heterozygosity (LOH) at the MYCL locus. PROCEDURE: To clarify the biological and clinical profiles of tumors with genetic abnormalities of the short arm of chromosome 1, we performed deletion mapping on 1p on 92 neuroblastoma tissues and corresponding noncancerous samples obtained from 92 cases for 24 micro- or minisatellite loci. RESULTS: LOH was detected in at least one locus of 1p in 43 (47%) cases. All samples were classified into four groups according to the deleted pattern: interstitial deletion (group I, n = 20), short terminal deletion (group ST, n = 6), large terminal deletion (group LT, n = 17), and without detectable deletion (group N, n = 49). All group I cases, whose SRO (shortest region of overlap) was at 1p36.1-2, survived disease free, and none of them showed MYCN amplification or high telomerase activity except for one case. On the other hand, in group LT cases, who showed a large terminal deletion from D1S162 (1p32-pter), including the SRO of group 1, only 5 out of 17 have survived disease free, and 13 showed MYCN amplification or high telomerase activity. The six group ST cases showed small terminal deletion from 1p36.3 with modest prognosis, similar to the group N. CONCLUSIONS: Thus, we propose three loci, 1p36.1-2, 1p32-34, and 1p36.3, as the candidate loci of neuroblastoma suppressor genes on chromosome 1p responsible for groups I, LT, and ST, respectively. Among them, the 1p32-34 locus may be associated with aggressiveness of tumor progression, possibly due to MYCN amplification and/or telomerase reactivation, while the remaining two loci may not.

IL-4 reduces resistance of mice to Trypanosoma cruzi infection.

The role of IL-4 has often been studied, especially in the Leishmania major infection model, but not in Trypanosoma cruzi infection. In the present study, the role of IL-4 in host defense against infection with the Tulahuen strain of T. cruzi was examined by depleting IL-4 with an anti-IL-4 monoclonal antibody in vivo. In both IL-4 depleted and control C57BL/6 mice, the parasitemia showed peaks on the 21st day of infection. Both parasitemia and mortality were decreased in IL-4 depleted mice compared with control mice when IFN-gamma and nitric oxide productions were increased in IL-4 depleted mice compared with control mice. The mice treated with N-nitro-L-arginine methyl ester, a competitive inhibitor of nitric oxide synthase, showed increased susceptibility to T. cruzi infection to the same level in both IL-4 depleted and control mice. Thus, it is suggested that endogenous IL-4 induces susceptibility to T. cruzi mainly by suppressing the production of IFN-gamma and nitric oxide, which has trypanocidal activity.

Allelotype frequency of the thiopurine methyltransferase (TPMT) gene in Japanese.

Polymorphisms at three loci in the thiopurine methyltransferase (TPMT) gene are known to be responsible for azathioprine and 6-mercaptopurine (6MP) toxicity. Among them, only TPMT*3C variant allele with A719G mutation was found in 15/522 (2.9%; 17/1044 alleles; 1.6%) Japanese individuals including two homozygotes. The allele frequency was different from that in Caucasians, and investigation of TPMT polymorphisms with consideration of ethnic differences before administration of azathioprine or 6MP may provide clinically useful information.

Immunohistochemical detection of telomerase (hTERT) protein in human cancer tissues and a subset of cells in normal tissues.

We examined human telomerase reverse transcriptase (hTERT) protein distribution by immunohistochemistry in cultured cells and tissue sections. Cells with telomerase activity had nuclear positive signals whereas cells without telomerase activity did not. In most normal epithelial tissues, hTERT expression was prominent in the early proliferative descendent progenitors cells. In cancers with high telomerase activity, hTERT expression was detected in almost all neoplastic cells and correlated with telomerase activity levels, whereas cancers with low telomerase activity had fewer hTERT-positive cancer cells. In pediatric neuroblastomas with a favorable outcome, both the percentage of positive cells and the signal intensities of each hTERT-expressing cell decreased. These studies indicate that detection of telomerase at the cellular level is achievable and may have utility in cancer diagnostics.

Multiple logistic regression analysis of risk factors for the development of steroid-dependent asthma in the elderly: a comparison with younger asthmatics.

BACKGROUND: The percentage of the aged among all patients with bronchial asthma is increasing. OBJECTIVE: To investigate the risk factors for the development of steroid-dependent asthma in the elderly. METHODS: A multiple logistic regression analysis involving various clinical factors between steroid-dependent and -independent asthma was carried out for 59 asthmatics aged over 60 years, including 16 patients with steroid-dependent asthma. The calculated risk for each factor was compared with that obtained from 122 younger asthmatics aged 20-59 years. RESULTS: Among the factors examined (sex, age, period from onset of asthma, type of asthma and family history of asthma, plus history of smoking, atopic dermatitis, allergic rhinitis, chronic sinusitis and nasal polyps), the significant risk factors for the development of steroid dependency in the elderly asthmatics were only family history of bronchial asthma (relative risk 3.6) and smoking history (relative risk 6.9). CONCLUSIONS: Some risk factors for steroid-dependent asthma in younger individuals were not significant in the elderly. Since the smoking history was most closely associated with the development of steroid dependency in the elderly, even though most of them had quit smoking, it is important for patients with asthma to avoid smoking.

Effects of pranlukast, a cysteinyl leukotriene antagonist, on bronchial responsiveness to methacholine in aspirin-intolerant asthmatics treated with corticosteroids.

Cysteinyl leukotrienes (cysLTs) are considered to be the most important mediator involved in the pathogenesis of aspirin-intolerant asthma (AIA). However, the role of cysLTs in the baseline condition of the pathophysiology of AIA when not exposed to non-steroidal antiinflammatory drugs (NSAIDs) as well as that in the pathophysiology of aspirin-tolerant asthma remains to be elucidated. Therefore, we evaluated the effect of pranlukast, a potent, selective cysLT receptor antagonist, on bronchial responsiveness to methacholine, a non-specific stimulus, in 7 well-controlled aspirin-intolerant asthmatics receiving oral or inhaled corticosteroid treatment. Pranlukast was orally administered at a dose of 225 mg twice daily to all patients for 4 weeks, and the methacholine challenge test was performed before and after pranlukast treatment. The methacholine provocative concentration producing a 20% fall in forced expiratory volume in 1 second (PC20-FEV1) was calculated as an index of bronchial hyperresponsiveness (BHR). The geometric mean values of PC20-FEV1 significantly (p = 0.028) increased from 0.34 mg/dl to 0.61 mg/dl after pranlukast treatment. No significant differences were observed in the baseline values of forced vital capacity (FVC) or FEV1 before and after pranlukast treatment. These findings suggest that antagonism of endogenous cysLT by pranlukast may be responsible for the improvement of BHR to methacholine.

Telomerase activity as a marker of breast carcinoma in fine-needle aspirated samples.

BACKGROUND: Telomerase activity in breast fine-needle aspiration (FNA) samples may have diagnostic utility. The purpose of this study was to compare in FNA samples of breast tumor the diagnostic accuracy as correlated with histologic final diagnosis. METHODS: Fine-needle aspiration samples were obtained from 617 patients with palpable breast tumors. Slide preparation and cytology were performed according to a uniform approach. Extracts derived from 10(3) cells from the residual cells in the syringe were used for the telomeric repeat amplification protocol (TRAP) assay. Of the original 617 patients, 220 underwent open biopsy or surgery, and 93 cancers and 127 patients' benign diseases were diagnosed by histologic examination. RESULTS: All 62 tumors that were diagnosed as "malignant" or "probably malignant" by FNA cytology were cancerous, and 50 cases (81%) showed detectable telomerase activity. Among 17 "atypical" or "indeterminate" cases, all 10 tumors with detectable telomerase activity subsequently were diagnosed as breast carcinoma whereas 6 of 7 tumors without telomerase activity were diagnosed as benign. Among the 141 "benign" or "unsatisfactory" samples, 12 of 21 cases with detectable telomerase activity subsequently were diagnosed as cancer. CONCLUSIONS: The diagnostic accuracy of telomerase activity in FNA samples is considered to be equivalent or slightly higher to that of cytology (86% vs. 70%). Detection of telomerase activity should be considered an alert for false-negative results of FNA cytology and may be useful as a diagnostic marker for breast malignancy, especially in samples cytologically undetermined to be malignant. Cancer (Cancer Cytopathol)

An autopsy case of diffuse panbronchiolitis associated with lung cancer.

The prognosis of diffuse panbronchiolitis (DPB) has been remarkably improved after the development of low-dose erythromycin therapy, possibly due to anti-inflammatory rather than anti-infective mechanisms. Interestingly, DPB associated with lung cancer is quite rare. Here, we report an autopsy case of DPB who developed lung cancer after a long successful therapy with low-dose erythromycin.

Successful treatment of systemic lupus erythematosus and pulmonary hypertension with intravenous prostaglandin I2 followed by its oral analogue.

Systemic lupus erythematosus (SLE) is sometimes reported to complicate fatal pulmonary hypertension. A 46-year-old woman, with a ten-year history of SLE and pulmonary hypertension, was admitted to our hospital complaining of dyspnea and chest pain. She suffered pulmonary hemorrhage and after steroid pulse therapy, she underwent continuous intravenous infusion of epoprostenol (prostaglandin I2) with corticosteroid for four weeks, which reduced the pulmonary artery pressure and resistance. Following the successful treatment, beraprost sodium, an oral PGI2 analogue, was given and it maintained pulmonary hypertension remittance for four years.

Clinical evaluation of idiopathic interstitial pneumonia and interstitial pneumonia associated with collagen vascular disease using logistic regression analysis.

OBJECTIVE: To clarify the differences in the clinical features between idiopathic interstitial pneumonia (IIP) and interstitial pneumonia associated with collagen vascular diseases (CVD-IP). METHODS: Symptoms, radiographic findings, pulmonary function, blood chemistry data including autoantibody, and bronchoalveolar lavage fluid (BALF) findings were compared using multiple logistic regression analysis. PATIENTS: The subjects were 44 patients clinically diagnosed with IIP and 33 patients with CVD-IP. RESULTS: The clinical features related to IIP were as follows: male sex, advanced age, past history of hypertension, presence of cough, exertional dyspnea, digital clubbing, an increased level of gamma-globulin, decreased lung volume on chest X-ray, and typical type according to the criteria for IIP on chest X-ray. Increased levels of rheumatoid factor and total cell number in BALF were related to CVD-IP. CONCLUSION: These findings are considered to be useful to differentiate IIP and CVD-IP.

Inhibitory effects of a lecithinized superoxide dismutase on bleomycin-induced pulmonary fibrosis in mice.

Oxidant/antioxidant imbalance is thought to be involved in the pathogenesis of idiopathic pulmonary fibrosis (IPF). Therefore, antioxidants, such as superoxide dismutase (SOD), are expected to have an inhibitory potential against IPF. To elucidate whether a lecithinized SOD (phosphatidylcholine [PC]-SOD) has the potential to be a new therapeutic agent for IPF, we investigated the inhibitory effects of PC-SOD at doses of 1 mg/kg/d (low dose) and 10 mg/kg/d (high dose) and of methylprednisolone (mPSL) on bleomycin (BLM)-induced pulmonary fibrosis in mice. Histopathologic evaluation and lung hydroxyproline content revealed that the severity of fibrosis was attenuated in mice treated with low-dose PC-SOD, whereas no significant effect was observed in other mice. In bronchoalveolar lavage fluid on Day 1 after treatment with BLM, BLM-induced increases in total cell number, populations of lymphocytes and neutrophils, and expression of messenger RNA for interleukin-1beta and platelet-derived growth factor (PDGF)-A were significantly suppressed in PC-SOD-treated mice. The suppression of PDGF-A expression was significantly greater in mice treated with low-dose PC-SOD than in mice treated with high-dose PC-SOD or mPSL. In summary, this study demonstrated the inhibitory effects of low-dose PC-SOD on the development of pulmonary fibrosis, which indicates the potential usefulness of PC-SOD as a new treatment agent for IPF or at least for BLM-induced pulmonary fibrosis in humans.

Multifocal neuroblastoma: biologic behavior and surgical aspects.

BACKGROUND: Although multifocal neuroblastoma is rare, its incidence has increased because of recent improvements in diagnostic tools and the introduction of mass screening. Among the 106 neuroblastoma cases treated at the authors' hospital between 1984 and 1998, 8 were multifocal neuroblastoma. METHODS: The authors examined clinicopathologic findings and biologic features, including MYCN amplification, NTRK1 and Ha-ras p21 expression, cellular DNA content, and telomerase activity in these 8 multifocal neuroblastoma cases. Moreover, clinicopathologic findings were investigated with a review of 53 published cases of multiple neuroblastoma in the literature published in English between 1966 and 1999. RESULTS: Among these eight cases, five were detected by mass screening and three were incidental neuroblastomas. Histologically, all tumors were classified as ganglioneuroma or favorable neuroblastoma except one advanced case. All tumors lacked the MYCN gene amplification and expressed NTRAK1 mRNA and Ha-ras p21 protein. Cellular DNA content showed that half of these tumors were near-triploid, and the proliferative index (%S-phase) of all tumors was less than 25%. High telomerase activity was detected in none of these cases. Four patients underwent multistage operation and five patients with bilateral adrenal neuroblastomas underwent tumor enucleation to preserve adrenal function. Currently, all patients are disease free and none have required corticosteroid replacement therapy. Among the previously reported 53 cases with multifocal neuroblastoma, 25 were incidentally detected, 18 had familiar history, and most patients without other major complications also had extremely good prognoses. CONCLUSIONS: These findings suggested that most multifocal neuroblastomas have favorable biologic features. Clinically, surgical approaches should be attempted to preserve organ function, especially adrenal function, and minimal invasive surgery should be performed. In cases of thoracoabdominal neuroblastoma, multistage surgery is effective and safe.

Psoriatic arthritis complicating lung cancer.

Psoriatic arthritis is an inflammatory arthritis associated with psoriasis. While an elevated incidence of lung cancer has been observed in patients with RA or psoriasis, there has been no report of psoriatic arthritis associated with lung cancer. We here report the first case of psoriatic arthritis which developed lung cancer. In this case, it was suspected that a combination of cigarette smoking, pulmonary fibrosis, and low-dose methotrexate therapy might have promoted the development of lung cancer.

Allelotype and loss of heterozygosity around the L-myc gene locus in primary lung cancers.

L-myc S-allele was reported to be associated with metastasis of lung cancer, indicating the existence of a putative tumor suppressor gene around the L-myc locus, in linkage disequilibrium. The relationship between the S-allele and inactivation of some tumor suppressor gene should be indicated by allelic loss. Therefore, we examined the association between the L-myc S-allele and loss of heterozygosity at 11 loci around the L-myc locus (1p34.3) in primary lesions or other biological characteristics in lung cancer. No associations between the S-allele and allelic loss around the L-myc locus or other characteristics were found. According to the deletion map, three shortest regions of overlap between D1S230 and D1S76 were identified. While loss of heterozygosity at SRO1, between D1S2797 and MYCL1, showed no relationship with the pathological stage, it was more frequently observed in squamous cell carcinoma than adenocarcinoma (P=0.019), and associated with high telomerase activity (P=0.046), an indicator of cellular immortality. In conclusion, we found three shortest regions of overlap (SROs) from D1S2797 to pter, and a tumor suppressor gene, which might be associated with suppression of lung cancer development but not with L-myc S-allele, may exist in SRO1.

p53 gene mutations are associated with shortened survival in patients with advanced non-small cell lung cancer: an analysis of medically managed patients.

Mutations in the p53 gene are common in many cancers. Nevertheless, the relationship between mutations of this tumor suppressor gene and patient survival in non-small cell lung cancer (NSCLC) remains unclear. Interpretation of prior studies of patient outcomes are complicated by the inclusion of both surgical and nonsurgical patients. To better isolate the potential effects of p53 gene mutations per se on tumor progression, we chose to examine patients with advanced disease in whom surgery was not performed (stages IIIA, IIIB, and IV). We have used PCR-denaturing gradient gel electrophoresis, a sensitive and specific method for the detection of a variety of p53 mutations in cytology or biopsy specimens, to evaluate the prognostic significance of p53 gene mutations in nonsurgical patients with advanced NSCLC. In 70 consecutive medical patients, p53 mutations were found in 29 cases (41%) at the time of initial diagnosis. Followed prospectively, patients with p53 mutations had a significantly reduced survival time after diagnosis than those without mutations (median survival, 17 versus 39 weeks; P = 0.0003) independent of other clinical factors. This abbreviated survival occurred in both patients who received chemotherapy (n = 39, P = 0.002) or best supportive care (n = 31, P = 0.018). These results indicate that mutations of the p53 gene in patients with NSCLC who do not undergo surgical resection portends a significantly worse prognosis.