Interaction of [Ru(bpy)2(dppz)]2+ with human telomeric DNA: preferential binding to G-quadruplexes over i-motif

Inspired by the enormous importance attributed to the structure and function of human telomeric DNA, we focus our attention on the interaction of [Ru(bpy)(2)(dppz)](2+) with the guanine-rich single-strand oligomer 5'-AGGGTTAGGGTTAGGGTTAGGG-3' (22AG) and the complementary cytosine-rich strand (22CT). In Na(+) buffer, 22AG may adopt an antiparallel basket quadruplex, whereas, it favours a mixed parallel/antiparallel structure in K(+) buffer. 22CT may self-associate at acidic pH into an i-motif. In this paper, the interaction between [Ru(bpy)(2)(dppz)](2+) and each unusual DNA was evaluated. It was interesting that [Ru(bpy)(2)(dppz)](2+) could promote the human telomeric repeat 22AG to fold into intramolecular antiparallel G-quadruplex without any other cations. What's more, [Ru(bpy)(2)(dppz)](2+) was found to have a strong preference for binding to G-quadruplexes that were induced through either Na(+) or K(+), while weak binding to i-motif was observed. The results also indicated that [Ru(bpy)(2)(dppz)](2+) could serve as a prominent molecular "light switch" for both G-quadruplexes, revealing a potential application of the title complex in luminescent signaling of G-quadruplex DNA.

Relationship between epithelial damage or basement membrane thickness and eosinophilic infiltration in nasal polyps with chronic rhinosinusitis

BACKGROUND

Chronic rhinosinusitis (CRS) with nasal polyps is characterized by eosinophilic infiltration. This study hypothesized that the aggregation of the mucosal pathology during remodeling is related to infiltrating eosinophils in patients with such nasal polyps.

OBJECT

To clarify the pathogenetic role of eosinophils in patients with CRS with nasal polyps, this study investigated the relationship between epithelial damage or basement membrane (BM) thickening and the epithelial infiltration of eosinophils in these nasal polyps.

METHODS

The number of eosinophils that infiltrated into the epithelial and subepithelial layers of sinonasal tissues was counted. The staging of epithelial damage allowed the quantification of epithelial loss.

RESULTS

Both epithelial damage and BM thickness in CRS, which were correlated with the number of infiltrated eosinophils, were significantly greater than in the control group. Neither parameter showed significant differences between the asthma and non-asthma groups. There was a significantly correlation in the eosinophilic infiltration between the subepithelial and epithelial layers.

CONCLUSION

It is suggested that eosinophils that infiltrate into both the epithelial and subepithelial layers play a part in the process of mucosal remodeling of CRS with nasal polyps.

Role of interleukin-17A in the eosinophil accumulation and mucosal remodeling in chronic rhinosinusitis with nasal polyps associated with asthma

BACKGROUND

Interleukin (IL)-17A is a highly inflammatory cytokine with a robust effect on stromal cells in many tissues. Although IL-17A is known to be associated with inflammatory lung disorders by triggering an accumulation of neutrophils, the effect of IL-17A on the upper airway is still uncertain. The expression of IL-17A and its role were investigated in the nasal polyps of chronic rhinosinusitis associated with asthma.

METHODS

IL-17A was detected by immunohistochemistry and quantitative real-time RT-PCR. The cellular source of IL-17A was examined by double staining with EG2, CD4 and neutrophil elastase. The tissue remodeling of the nasal polyps was evaluated by assessing the epithelial damage and basement membrane thickness.

RESULTS

Both the immunoreactivity and mRNA of IL-17A were significantly detected in the nasal polyps in comparison with control normal sinus mucosa. The localization of IL-17A expression predominantly coincided with eosinophils and CD4-positive lymphocytes. Furthermore, the number of IL-17A-positive cells correlated with tissue eosinophils, but not with neutrophils. The degree of epithelial damage and basement membrane thickness was dependent on the number of infiltrated IL-17A-positive cells.

CONCLUSION

The present study suggests, for the first time, that IL-17A plays an important role in the eosinophil accumulation in the nasal polyps and the remodeling of the nasal polyps of chronic rhinosinusitis associated with asthma.

Ultrafast lasing due to electron-hole plasma in ZnO nano-multipods

Dynamics of stimulated emission and ultrafast lasing in ZnO nano-multipods has been investigated with a femtosecond optical Kerr shutter technique. Under band-to-band excitation with high density, stimulated emission is observed around 395-400 nm with a mode-like structure. The stimulated emission emerges with an onset time of ∼2 ps and then the intensity gradually decreases with time having a blue-shift and a spectral narrowing. The characteristics of the blue-shift and spectral narrowing suggest that not only recovery of bandgap renormalization but also conversion from an electron-hole plasma (EHP) state to high density excitonic state takes place as the carrier density decreases due to recombination of electrons with holes. The mode-like structure observed strongly indicates that a high quality resonant cavity is formed between the two facets toward the leg length direction of individual nano-multipod. These results show that the ultrafast lasing observed around 395-400 nm in ZnO nano-multipods comes from population inversion in the EHP regime. We also found that the initial carrier distribution of the EHP regime in nano-multipods is much wider than that in ZnO thin films, implying that the carrier diffusion might be suppressed by their nano-size structure.

Impact of double-balloon endoscopy on the diagnosis of jejunoileal involvement in primary intestinal follicular lymphomas: a case series

In recent years, primary gastrointestinal follicular lymphoma has been increasingly detected in the duodenum on esophagogastroduodenoscopy (EGD). Primary gastrointestinal follicular lymphomas are frequently distributed to multiple sites in the gastrointestinal tract. Therefore, investigation into the spread of follicular lymphomas in the small bowel is important in order to determine the most appropriate treatment strategy. The performance of double-balloon endoscopy (DBE) in the diagnosis of jejunoileal follicular lymphoma lesions has not been fully evaluated. We aimed to investigate the value of DBE in addition to computed tomography (CT) and (18)F-fluorodeoxyglucose positron emission tomography ((18)F-FDG-PET) in the diagnosis of jejunoileal follicular lymphoma. DBE with biopsy was performed in seven patients with primary duodenal follicular lymphoma diagnosed by EGD, in order to investigate jejunoileal involvement. Jejunoileal follicular lymphoma lesions were detected by DBE in six out of the seven patients (three in the jejunum and three in the jejunum and ileum), whereas CT and (18)F-FDG-PET failed to detect the existence of these lesions. Endoscopic findings of the jejunoileal lesions revealed multiple white nodules and white villi, which were similar to those of duodenal lesions. DBE was more useful for the diagnosis of jejunoileal involvement in primary intestinal follicular lymphoma than CT and (18)F-FDG-PET. The use of DBE will become important for determining the most appropriate treatment for gastrointestinal follicular lymphoma.

Flat adenoma-carcinoma sequence with high-malignancy potential as demonstrated by CD10 and beta-catenin expression: a different pathway from the polypoid adenoma-carcinoma sequence

AIMS

CD10+ colorectal carcinomas have a high risk of giving rise to liver metastasis. The aim was to examine phenotypic expression in colorectal neoplasia and to elucidate changes in such expression through the adenoma-carcinoma sequence.

METHODS AND RESULTS

We examined the expression of various proteins immunohistochemically in 111 flat [non-polypoid growth (NPG)] colorectal neoplasms, categorized into 28 low-grade (NPG-LGN), 44 high-grades (NPG-HGN) and 39 cases of invasive neoplasia (NPG-IN), as well as in 96 polypoid [polypoid growth (PG)] neoplasms, categorized into 26 PG-LGN, 39 PG-HGN and 31 PG-IN according to the Vienna classification. CD10 was more frequently expressed in NPG than in PG neoplasia. MUC2 and MUC5AC were more frequently expressed in PG than in NPG neoplasias. Nuclear beta-catenin was more frequently expressed in NPG-LGN than in PG-LGN. No difference in p53 expression was found between NPG and PG neoplasia.

CONCLUSIONS

From the viewpoint of the expression of CD10 and beta-catenin, it would appear that NPG-LGN differs significantly from PG-LGN, thereby indicating that NPG-LGN is a precursor of CD10+ carcinoma. It is important to ensure that NPG neoplasia is not overlooked if cases of CD10+ carcinoma are to be detected at an early stage.

Genomic and functional analyses of MUTYH in Japanese patients with adenomatous polyposis

The present study was undertaken to elucidate germ line mutations of the base excision repair gene, MUTYH, in Japanese patients with adenomatous polyposis. We screened germ line mutations of adenomatous polyposis coli (APC) gene and MUTYH in 66 Japanese patients with adenomatous polyposis. APC was screened by the protein truncation test, while MUTYH was screened by polymerase chain reaction-based single-strand conformation polymorphism and direct sequencing. The nicking assay was applied in order to evaluate the DNA glycosylase activity of the identified MUTYH variant. In this study, Seven MUTYH variants were identified in 16 of 21 APC-negative patients. Q324H mutation was the most frequent mutation, with an allele frequency of 49%. Two patients carried biallelic mutations other than Q324H; a patient had biallelic G272E and A359V mutations, while the other had compound heterozygotes of P18L and G25D mutations. Nicking assay for G272E using the corresponding mouse MUTYH mutant with G257E revealed that G272E is a variant to cause an impaired DNA glycosylase activity. Homozygous MUTYH mutation accounts for approximately 10% of Japanese patients with adenomatous polyposis. G272E may be one of the mutations specific to patients with adenomatous polyposis in East Asia.

Raloxifene acutely reduces glutamate-induced intracellular calcium increase in cultured rat cortical neurons via inhibition of high-voltage-activated calcium current

There is increasing evidence indicating that estrogen replacement therapy produces neuroprotective actions but has undesirable side effects on the reproductive system. Raloxifene is a selective estrogen receptor modulator that exerts estrogen agonist action in the brain while acting as an estrogen antagonist in the reproductive system. In the present study, we investigated whether raloxifene affected the glutamate-induced calcium (Ca2+) overload in rat cultured cortical neurons. The bulk cytosolic intracellular Ca2+ level was measured by using confocal microscopy with fluorescent Ca2+ probe fluo3. Whole-cell recording technique was used to observe the effects of raloxifene on N-methyl-D-aspartate (NMDA)-evoked and voltage-activated Ca2+ currents in cultured cortical neurons. Pre-exposure of cortical neurons to raloxifene (0.5 microM-10 microM) for 3 min attenuated intracellular Ca2+ increase induced by application of glutamate (300 microM) for 1 min. The action of raloxifene was reversible after washout. ICI 182,780 and thapsigargin did not block the action of raloxifene. In whole-cell recording experiments, raloxifene (10 microM) significantly reduced the amplitude of the high-voltage-activated Ca2+ current but had no effect on NMDA-evoked Ca2+ current. The present study demonstrates that raloxifene acutely reduces glutamate-induced intracellular Ca2+ increase probably via inhibition of high-voltage-activated calcium channels.

Risk factors for local recurrence of superficial esophageal cancer after treatment by endoscopic mucosal resection

BACKGROUND AND STUDY AIM

The aim of this study was to elucidate the risk factors for local recurrence after endoscopic mucosal resection (EMR) treatment for superficial esophageal cancer (SEC).

PATIENTS AND METHODS

We performed a retrospective analysis of the clinical course of 62 patients with 64 SECs that were treated by EMR between 1993 and 2004. Follow-up examinations by chromoscopy with iodine solution and biopsy were performed 3 months, 6 months, 12 months, and then annually after EMR. Local recurrence was defined as a histologically confirmed finding of cancer cells at the site of the preceding EMR. The contributions of lesion-related and procedure-related factors to local recurrence were analyzed retrospectively.

RESULTS

Local recurrence was detected in 14/64 SECs 3-36 months after EMR. Of the lesion-related factors we assessed, local recurrence was found to be more frequent in SECs with a larger diameter (P = 0.01), larger circumferential spread (P = 0.04), or deeper invasion (P = 0.04), although the last two factors failed to demonstrate statistical significance after correction for multiple testing. Piecemeal resection did not increase the risk of local recurrence (P = 0.11), but the need for adjunctive coagulation therapy was found to increase the risk of local recurrence (P = 0.06).

CONCLUSIONS

Larger SECs are associated with a higher risk of local recurrence after EMR. In patients with residual lesions, coagulation therapy does not seem to be adequate as additional endoscopic treatment.

Estradiol increases proteinuria and angiotensin II type 1 receptor in kidneys of rats receiving L-NAME and angiotensin II

Prospective, placebo-controlled clinical trials suggest that estrogen may have adverse effects on the vascular system in women. The goal of this study was to determine if 17beta-estradiol (E2) would have adverse effects on the renovasculature in a rat model of renal injury characterized by low nitric oxide (NO) and high angiotensin II (AngII). We studied female Wistar rats that were sham-operated (sham), ovariectomized (OVX), or ovariectomized and replaced with E2 (OVX/E2). All rats were maintained on a high salt diet and renovascular injury was caused by treating rats with an inhibitor of NO synthase, N(omega)-nitro-L-arginine-methyl-ester (L-NAME), for 14 days, plus AngII on days 11 through 14. L-NAME/AngII treatment, as compared to placebo, caused proteinuria, glomerular injury, and fibrinoid necrosis of renal arterioles in sham-operated rats. Ovariectomy reduced L-NAME/AngII-induced renal damage, whereas E2 treatment increased L-NAME/AngII-induced damage in OVX rats. In rats treated with L-NAME/AngII, levels of AngII type 1 receptor (AT(1)R) protein were higher in the renal cortex of sham and OVX/E2 rats than in OVX rats. AT(1)R protein correlated with renal injury. E2 treatment also increased expression of AT(1)R mRNA. Thus, under conditions of low NO and high AngII, E2 exacerbated renal injury. E2-mediated increases in renal cortical AT(1)R expression may represent a novel mechanism for the adverse renovascular effects of estrogen.

The shape control of ZnO based nanostructures

Tetrapod-shape ZnO nanostructures are formed on Si substrates by vapor phase transportation method. The effects of two important growth parameters, growth temperature and VI/II ratio, are investigated. The growth temperature is varied in the range from 600 degrees C to 900 degrees C to control the vapor pressure of group II-element and the formation process of nanostructures. VI/II ratio was changed by adjusting the flux of carrier gas which affects indirectly the supplying rate of group VI-element. From the scanning electron microscopy (SEM), systematic variation of shape including cluster, rod, wire and tetrapod was observed. ZnO tetrapods, formed at 800 degrees C under the carrier gas flux of 0.5 cc/mm2 min, show considerably uniform shape with 100 nm thick and 1-1.5 microm long legs. Also stoichiometric composition (O/Zn - 1) was observed without any second phase structures. While, the decrease of growth temperature and the increase of carrier gas flux, results in the irregular shaped nanostructures with non-stoichiometric composition. The excellent luminescence properties, strong excitonic UV emission at 3.25 eV without deep level emission, indicate that the high crystalline quality tetrapod structures can be formed at the optimized growth conditions.

Growth of well-aligned ZnO nanorods using auge catalyst by vapor phase transportation

Well-aligned ZnO nanorods have been achieved using new alloy (AuGe) catalyst. Zn powder was used as a source material and it was transported in a horizontal tube furnace onto an AuGe deposited Si substrates. The structural and optical properties of ZnO nanorods were characterized by scanning electron microscopy, high resolution X-ray diffraction, and photoluminescence. ZnO nanorods grown at 650 degrees C on 53 nm thick AuGe layer show uniform shape with the length of 8 +/- 0.5 microm and the diameter of 150 +/- 5 nm. Also, the tilting angle of ZnO nanorods (+/- 5.5 degrees) is confirmed by HRXRD. High structural quality of the nanorods is conformed by the photoluminescence measurement. All samples show strong UV emission without considerable deep level emission. However, weak deep level emission appears at high (700 degrees C) temperature due to the increase of oxygen desertion.

[Pyrethroid and DDT resistance of Anopheles gambiae s.s. (Diptera: Culicidae) in five agricultural ecosystems from Côte-d'Ivoire]

The promotion of pyrethroid impregnated bednets among the populations is a major activity of the National Malaria Vector Control Programs in African tropical countries. However pyrethroid resistance in Anopheles gambiae, a major malaria vector, has been observed in several parts of Côte-d'Ivoire since 1993. As insecticides used in agriculture against pests are frequently considered as important factors responsible for resistance in malaria vectors, we have evaluated insecticide resistance of An. gambiae populations taking into account the main crops cultivated in Côte-d'Ivoire. Five areas were selected according to the use of insecticide either in agriculture or for domestic purposes: a urban area where vegetables and rice are main crops, a rural rice growing area, a rural area of coffee/cocoa production, a rural area of fruit farming and a rural area without any use of agricultural insecticide. Susceptibility tests were carried out using WHO diagnostic test kits. About 6500 females of An. gambiae were exposed to insecticide impregnated papers (permethrin 1%, deltamethrin 0.05%, DDT 4%) for one hour. Results confirmed that both mortality rates and knockdown time analysis were important to study the resistance data. By using mortality rates, populations of An. gambiae were found to be resistant to pyrethroids and DDT in four of the five areas. Resistance was the highest in urban area, lower in fruit and coffee/cocoa areas and at low level in rice growing area. An. gambiae from area without agricultural treatment was found susceptible to pyrethroids but slightly resistant to DDT A significant increase of knockdown time was observed in all areas with the 3 insecticides. These results agreed with previous studies showing that kdr mutation was the main resistance mechanism to pyrethroids in An. gambiae populations in Côte-d'Ivoire. They also agreed with knockdown time which is an early indicator of resistance development for the population in area without agricultural treatment. In this population the frequency of homozygous resistant individuals was probably too low to have a significant decrease of mortality rates to pyrethroids.

Candida glabrata fungemia in a diabetic patient with neurogenic bladder: successful treatment with micafungin

A 69-year-old man was transferred to our hospital because of fever and acute renal failure. 5 weeks prior to admission, he was admitted to another hospital and treated with several antibiotics including vancomycin, but fever did not subside and renal dysfunction showed rapid progression. On admission, laboratory findings revealed pyuria, inflammatory changes, acute renal failure, and disseminated intravascular coagulation (DIC). Computed tomography showed left ureteral stone and hydronephrosis. Gallium scintigraphy showed avid uptake in the left kidney. Serum concentration of vancomycin was 57.4 micro/ml. Candida glabrata was isolated from blood, sputum and urine. Under the diagnosis of fungemia and left pyelonephritis, he was treated with micafungin (150 mg/day), gabexate mesilate and insertion of a double-ended pigtail catheter. The above treatment produced regression of systemic inflammation, DIC and acute renal failure. At the last follow-up 3 weeks after discharge, ureteroscopy showed that the ureter stone had already passed but a soft white-yellowish bezoar was detected in the ureter. In this case, neurogenic bladder, poorly controlled diabetes, and long-term antibiotic treatment probably enhanced the development of C. glabrata infection. Antifungal treatment with micafungin is useful in patients with non-albicans Candida infection.

Gli1, downregulated in colorectal cancers, inhibits proliferation of colon cancer cells involving Wnt signalling activation

BACKGROUND

Early events in the progression of 90% of sporadic colorectal cancers depend on constitutive activation of Wnt signalling. Recent data also indicate a close association between the Hedgehog (Hh) and Wnt pathways in colonic epithelial cell differentiation.

AIMS

To investigate whether expression of Gli1, a transactivator of Hh signalling, can suppress Wnt signalling and inhibit proliferation of human colorectal cancer cells.

METHODS

Gli1 and nuclear beta-catenin expression were examined in a series of 40 human colorectal cancers by immunohistochemistry. We quantified Gli1 and nuclear beta-catenin staining as markers of Hh and Wnt pathway activation, respectively. Two human colon cancer cell lines, SW480 and HCT116, with mutations in APC and beta-catenin, respectively, were used. The effects of Gli1 overexpression on Wnt transcriptional activity, beta-catenin subcellular distribution, and proliferation in these cells were analysed.

RESULTS

Nuclear accumulation of beta-catenin and the Gli1 staining level were inversely associated in the 40 human colorectal cancers. Wnt transcriptional activity was reduced in Gli1 transfected cells. These effects were observed even in Gli1 transfected cells cotransfected with mutated beta-catenin. Furthermore, nuclear accumulation of beta-catenin was diminished compared with that in empty vector transfected cells, and downregulated transcription of c-Myc was observed in Gli1 transfected cells. Proliferation of Gli1 transfected cells was also significantly suppressed compared with that in empty vector transfected cells.

CONCLUSIONS

Our data suggest that Gli1 plays an inhibitory role in the development of colorectal cancer involving Wnt signalling, even in cases with the stabilising mutation of beta-catenin.