The role of Narrow Band Imaging (NBI) in the diagnosis of sinonasal diseases.

BACKGROUND: Narrow band imaging (NBI) endoscopy is an optical method that helps to characterise tissue vasculature. Its appli- cation in sinonasal pathology remains scarce and a systematic study of its application to rhinology is lacking. The aim of this study is to analyse and describe the normal sinonasal mucosa under NBI light and to characterise the microvascular features of various sinonasal pathologies. We also want to suggest a classification of the patterns, peculiar to this district, and to evaluate whether they can be indicative of a specific physiological or pathological condition. METHODS: Digital videos and images under white light and NBI of 103 patients (82 evaluated) with 29 sinonasal pathologies and 55 controls (33 evaluated). were independently analysed by three otolaryngologists and the final pattern was then arranged for each image, reaching an agreement between the individual evaluations. RESULTS: Once the appearance of normal sinonasal (SN) mucosa was established (SN1), four patterns for the pathological mucosa were described and a working classification was proposed (SN2, SN3, SN4, SN5). We calculated specificity (80.6% vs 90.6%), sensi- tivity (20% vs 38.5%), PPV (46.1% vs 50%), NPV (54.7% vs 85.7%) and accuracy (53% vs 80.3%) of the ability of SN4 and SN5 pattern to discriminate between benign and malignant nasal neoformations. CONCLUSIONS: This is the first study to propose a systematic NBI description and a classification of the vasculature of healthy and pathological mucosa in the sinonasal tract. Our preliminary results show that this technique can help in the workup of several rhinologic conditions and especially in distinguishing benign from malignant tumors.

Gate-Tunable Atomically Thin Lateral MoS2 Schottky Junction Patterned by Electron Beam.

Among atomically thin two-dimensional (2D) materials, molybdenum disulfide (MoS2) is attracting considerable attention because of its direct bandgap in the 2H-semiconducting phase. On the other hand, a 1T-metallic phase has been revealed, bringing complementary application. Recently, thanks to top-down fabrication using electron beam (EB) irradiation techniques, in-plane 1T-metal/2H-semiconductor lateral (Schottky) MoS2 junctions were demonstrated, opening a path toward the co-integration of active and passive two-dimensional devices. Here, we report the first transport measurements evidencing the formation of a MoS2 Schottky barrier (SB) junction with barrier height of 0.13-0.18 eV created at the interface between EB-irradiated (1T)/nonirradiated (2H) regions. Our experimental findings, supported by state-of-the-art simulation, reveal unique device fingerprint of SB-based field-effect transistors made from atom-thin 1T layers.

Endoscopic mucosal resection in high- and low-volume centers: a prospective multicentric study.

BACKGROUND: Endoscopic mucosal resection (EMR) is an effective therapeutic technique well-standardized worldwide for the treatment of gastrointestinal neoplasm limited to the mucosal layer. To date, no study has compared technical and clinical differences based on the number of EMRs performed per year. This study aimed to compare EMR technical success, complications, and clinical outcome between low-volume centers (LVCs) and high-volume centers (HVCs). A total of nine endoscopic centers were included in the study. METHODS: This prospective study investigated consecutive patients with sessile polyps or flat colorectal lesions 1 cm or larger referred for EMR. RESULTS: A total of 427 lesions were resected in 384 patients at nine endoscopic centers. Males accounted for 60.4% and females for 39.6% of the patients. Most of the EMRs (84.8%) were performed in HVCs and only 15.2% in LVCs. All the lesions were resected in only one session. Argon plasma coagulation was performed on the margins of piecemeal resection in 15.7% of the patients in HVCs only. Complete excision was achieved for 98.6% of the lesions in HVCs and 98.8% of the lesions in LVCs. The complication rate was 4.4% in HVCs and 4.6% in LVCs (p = 0.94). Delayed bleeding occurred in 2.5% of the HVC cases and 3.1% of the LVC cases. Perforation occurred in 1.9% of the HVC cases and 1.5% of the LVC cases (p = 1.00). Recurrences were experienced with 15% of the lesions: 15.5% in HVCs and 14% in LVCs (p = 0.79). CONCLUSIONS: The study showed that EMR can be performed also in LVC.

Current saturation and voltage gain in bilayer graphene field effect transistors.

The emergence of graphene with its unique electrical properties has triggered hopes in the electronic devices community regarding its exploitation as a channel material in field effect transistors. Graphene is especially promising for devices working at frequencies in the 100 GHz range. So far, graphene field effect transistors (GFETs) have shown cutoff frequencies up to 300 GHz, while exhibiting poor voltage gains, another important figure of merit for analog high frequency applications. In the present work, we show that the voltage gain of GFETs can be improved significantly by using bilayer graphene, where a band gap is introduced through a vertical electric displacement field. At a displacement field of -1.7 V/nm the bilayer GFETs exhibit an intrinsic voltage gain up to 35, a factor of 6 higher than the voltage gain in corresponding monolayer GFETs. The transconductance, which limits the cutoff frequency of a transistor, is not degraded by the displacement field and is similar in both monolayer and bilayer GFETs. Using numerical simulations based on an atomistic p(z) tight-binding Hamiltonian we demonstrate that this approach can be extended to sub-100 nm gate lengths.

QuantiFERON-TB Gold and the TST are both useful for latent tuberculosis infection screening in autoimmune diseases.

Screening for active tuberculosis (TB) and latent TB infection (LTBI) is mandatory prior to the initiation of tumour necrosis factor-alpha inhibitor therapy. However, no agreement exists on the best strategy for detecting LTBI in this population. The aim of the present study was to analyse the performance of the tuberculin skin test (TST) and QuantiFERON-TB Gold in-tube (QFT-GIT) on LTBI detection in subjects with immunomediated inflammatory diseases (IMID). The TST and QFT-GIT were prospectively performed in 398 consecutive IMID subjects, 310 (78%) on immunosuppressive therapy and only 16 (4%) had been bacillus Calmette-Guérin (BCG) vaccinated. Indeterminate results to QFT-GIT were found in five (1.2%) subjects. Overall, 74 (19%) out of 393 subjects were TST-positive and 52 (13%) were QFT-GIT-positive. Concordance between TST and QFT-GIT results was good (87.7%): 13 were QFT-GIT-positive/TST-negative and 35 QFT-GIT-negative/TST-positive. By multivariate analysis both tests were significantly associated with older age. Only the TST was associated with BCG vaccination and radiological lesions of past TB. Use of immunosuppressive drugs differently modulated QFT-GIT or TST scoring. Use of the QuantiFERON-TB Gold in-tube, as a screening tool for latent tuberculosis among immunomediated inflammatory disease subjects, is feasible. Until further data will elucidate discordant tuberculin skin test/QuantiFERON-TB Gold in-tube results, a strategy of simultaneous tuberculin skin and QuantiFERON-TB Gold in-tube testing in a low prevalence bacillus Calmette-Guérin vaccinated population, should maximise potentials of latent tuberculosis diagnosis.

Autologous stem cell transplantation improves microcirculation in systemic sclerosis.

BACKGROUND: In systemic sclerosis (SSc) reduced capillary density decreases blood flow and leads to tissue ischaemia and fingertip ulcers. Nail fold videocapillaroscopy (NVC) is a diagnostic and follow-up parameter useful to evaluate the severity, activity and the stage of SSc microvascular damage. Autologous haemopoietic stem cell transplantation (HSCT) is a new treatment for patients with severe diffuse cutaneous systemic sclerosis (dcSSc) refractory to conventional therapies. We aimed to evaluate the improvement of microvasculature after HSCT using NVC. METHODS: A total of 16 patients with severe dcSSc with a "late" videocapillaroscopy pattern underwent an immunesuppressive treatment: 6 were treated with HSCT and 10 with monthly pulse cyclophosphamide (CYC) 1 g for 6 months and then orally with 50 mg/day for further 6 months. NVC was performed before and after 3 months from the beginning of each treatment and then repeated every 3 months. RESULTS: In all patients, before HSCT NVC showed large avascular areas and ramified capillaries and vascular architectural disorganisation ("late" pattern). At 3 months after HSCT, the NVC pattern changed from "late" into "active", showing frequent giant capillaries (>6/mm) and haemorrhages, absence of avascular areas and angiogenesis phenomena; 1 year after HSCT, microvascular abnormalities were still in the "active" pattern. In patients treated with CYC, no NVC modifications were observed during 24 months of follow-up and the pattern always remained "late". CONCLUSIONS: These results indicate that HSCT with a high dose CYC regimen may foster vascular remodelling, while CYC at lower doses and with a chronic regimen does not influence the microvasculature.

A human Y-linked DNA polymorphism and its potential for estimating genetic and evolutionary distance.

A human DNA sequence (p12f2), derived from a partial Y-chromosome genomic library and showing homology with the X and Y chromosomes and with an undetermined number of autosomes, detected two Y-specific restriction fragment length variants on male DNA that had been digested with Taq I and Eco RI. These variants may have been generated through a deletion-insertion mechanism and their pattern of holoandric transmission indicates that they represent a two-allele Y-linked polymorphism (RFLP). By means of DNA from patients with inborn deletions in chromosome Y, this polymorphic DNA site was mapped to the interval Yq11.1-Yq11.22. The frequency of the rarest allele was about 35 percent in Algerian and Sardinian human males, whereas it was only 4 percent among Northern Europeans. The p12f2 probe also detected Y-specific DNA fragments in the gorilla and chimpanzee. In view of the monosomy of the Y chromosome in mammalian species, Y-linked RFLP's may prove to be more useful than autosomal or X-linked markers in estimating genetic distances within and between species.

Vitamin E gel reduces time of healing of digital ulcers in systemic sclerosis.

BACKGROUND: In systemic sclerosis (SSc), digital ulcers (DU) are painful, difficult to heal and frequently infected, thus greatly affecting quality of life and increasing SSc-related disability. Vitamin E has been previously used in cutaneous lesions for its antioxidant and anti-inflammatory effects. OBJECTIVES: To study the healing effect of D-alpha-tocopheryl acetate (acetic ester of alpha-tocopherol) (VE) gel on DU of SSc patients. METHODS: 27 SSc patients with a total of 86 DU were enrolled in an open pilot study. The patients were randomly assigned to two groups: 15 patients were treated until DU healing with the local standard ulcer care protocol with the application of vitamin E gel (experimental group), while 12 patients were treated with standard ulcer care protocol only (control group). In both groups, DU were treated twice a week and pain was scored by a NRS (numeric rating scale). In both groups the cost of medications was analysed. RESULTS: VE induced a faster healing of DU in respect to controls (13.22+/-2.72 weeks, versus 20.94+/-3.65; p<0.0001) with a lower number of medications (26.18+/-5.63 vs. 41.88+/-7.31; p<0.0001). Resolution of pain was faster in experimental (17.82+/-4,59 medications) than in controls (26.26+/-19.16 medications) (p=0.0022). In the experimental group, the cost of medications was significantly lower (6,919.15 euros/patient) than in the control group (11,056.32 euros/patient). CONCLUSION: The application of VE reduces time of healing and has a faster resolution of pain, with a significant reduction of costs. Topical VE may improve the management of DU in SSc.

The safety of iloprost in systemic sclerosis in a real-life experience.

Iloprost (ILO) is employed intravenously for the treatment of severe Raynaud phenomenon (RP) and digital ulcers (DU) in systemic sclerosis (SSc). The aim of this study was to evaluate the safety and tolerability of the intravenous treatment with ILO in different phases of SSc. Eighty-one consecutive non-selected SSc patients, all on nifedipine, with moderate RP, treated with ILO infusion, were retrospectively evaluated. Patients were sub classified according to the edematous or fibrotic/atrophic cutaneous phase of the disease. ILO was infused with a progressive increase of the dosage up to the achievement of patient's tolerance, 1 day/week. In cases of slower infusion regimen due to adverse events (AE) at the beginning of the administration, patients received a lower dose of the drug (not possible to quantify precisely the final cumulative dosage). 16/81 SSc patients presented digital edema, 5 developed diarrhea, and 9 developed transient hypotension during the infusion at 20 ml/h that ameliorated when the drug was withdrawn. Moreover, 10/16 edematous patients experienced significant and painful digital swelling, unlike patients in the fibrotic group (p < 0.0001); 11/16 patients reported flushing and 7/16 headache, always controlled with dose tapering below 10 ml/h. In the atrophic/fibrotic phase patients (65/81), 10 developed diarrhea and 24 hypotension at infusion rate of 20 ml/h that led to temporary withdrawal of the drug. When ILO was restarted and kept below 10 ml/h, no side effects were experienced. 23/65 patients experienced flushing and 8/65 headache, all controlled with infusion reduction below 10 ml/h. In these patients, adverse events were significantly less frequent than in the edematous group (p = 0.023 and p = 0.008, respectively). Our data suggest that calcium channel blockers should be transitorily stopped while using ILO and that a pre-treatment approach might reduce or control adverse events. In patients with digital edema, ILO infusion should be carefully employed after the evaluation of patient's drug tolerance.

Long-term endoscopic and clinical follow-up of untreated type 1 gastric neuroendocrine tumours.

BACKGROUND AND AIMS: Type 1 gastric neuroendocrine tumour surveillance and treatment are a matter of debate. Endoscopic, or surgical, resection and chronic somatostatin analog therapy have been proposed. Based on the favourable behaviour of this neoplasm, we performed an endoscopic and clinical follow-up in 11 patients affected by type 1 gastric neuroendocrine tumours, avoiding any specific treatment. METHODS: Between 1994 and 2006, we prospectively recorded the data of 11 untreated patients with type 1 gastric neuroendocrine tumours who underwent an endoscopic and clinical follow-up. All the patients were also evaluated by means of an abdominal computed tomography scan, somatostatin receptor scintigraphy and blood tests. RESULTS: During the follow-up (median 54 months, range 9-136), the endoscopic picture of 4 (36%) out of 11 patients changed in terms of increased number of lesions. In none of the cases were detected any lesions that exceeded 10mm in diameter, and none of the patients demonstrated any evidence of local or distant metastases. CONCLUSIONS: Our data confirm the literature data of the indolent behaviour of type 1 gastric neuroendocrine tumours and suggest that a careful endoscopic follow-up, without any treatment, might represent a reasonable and safe option in selected patients.

First principles investigation of tunnel FETs based on nanoribbons from topological two-dimensional materials.

We explore nanoribbons from topological two-dimensional stanene as a channel material in tunnel field effect transistors. This novel technological option offers the possibility of building pure one-dimensional (1D) channel devices (comprised of a 1D chain of atoms) due to localized states placed at the nanoribbon edges. The investigation is based on first-principles calculations and multi-scale transport simulations to assess the performance of devices against industry requirements and their robustness with respect to technological issues like line edge roughness, detrimental for nanoribbons. We will show that edge states are robust with respect to the presence of non-idealities (e.g., atom vacancies at the edges), and that 1D-channel TFETs exhibit interesting potential for digital applications and room for optimization in order to improve the ION/IOFF at the levels required by the ITRS, while opening a path for the exploration of new device concepts at the ultimate scaling limits.

Metal stent placement in acute malignant colorectal obstruction.

BACKGROUND: Obstruction is a common complication of advanced colorectal cancer. Stent insertion can reduce the need for emergency surgery and allows chemotherapy to begin immediately. AIMS: To evaluate the technical and clinical success and long-term outcome of stent placement in the management of acute malignant colorectal obstruction. METHODS: From July 2002 to April 2005, 29 self-expanding metal stents were placed in 24 patients (13 men, mean age 67 years, range 36-83). Stents were inserted under endoscopic and fluoroscopic control. Patients were clinically and endoscopically followed up. RESULTS: Twenty-eight out of 29 stents were successfully placed (96.5%) in 23 out of 24 patients with 25 strictures. The clinical success rate was 95.8% (23/24). Two early stent migrations were observed in two patients (8.3%). Late complications developed in eight patients (33.3%) after a median of 3.8 months (range <1-8.6): two migrations and six occlusions. The median survival was 9.8 months (range <1-27). Eleven patients (45.8%) died from progressive disease without any clinical evidence of recurrent obstruction. CONCLUSION: Stent placement is safe and effective. Stent complications are frequent but not life-threatening, and are easy to manage. An improvement in stent design and well-scheduled follow-up are needed in order to prevent such complications.

Is colonoscopy a suitable investigation in the preoperative staging of ovarian cancer patients?

BACKGROUND: During ovarian cancer surgery, colorectal resection may be required. In our institution, preoperative colonoscopy is performed in order to assess visceral involvement. AIMS: The aim of this study was to evaluate the utility of preoperative colonoscopy in ovarian cancer patients and the prevalence of adenomas in this population. PATIENTS: This retrospective study involved 144 consecutive patients with a supposed primary ovarian cancer. METHODS: Mucosal infiltration, bowel wall elasticity and bowel fixation were used to predict colorectal infiltration. Endoscopic and pathological findings were compared. All the polyps observed were removed. RESULTS: Six patients (4.2%) were excluded because of a misdiagnosed colorectal cancer metastatic to the ovary. Eight (6%) patients were considered, at endoscopy, to have a bowel infiltration and eight (6%), an uncertain infiltration. In 116 (88%), no signs of bowel infiltration were observed. The pathological analysis showed that colonoscopy had a low sensitivity (44%) in identifying bowel infiltration. Specificity was 100%, positive predictive value 100% and negative predictive value 92%. The overall accuracy was about 90%. Thirty-six adenomas were removed in 26 (20%) women. CONCLUSIONS: Colonoscopy identifies a not insignificant number of ovarian cancer patients requiring colorectal surgery. An increased prevalence of adenomas was not observed in this population.

Endoscopic argon plasma coagulation for palliative treatment of malignant airway obstructions: early results in 47 cases.

Argon plasma coagulation (APC) is a new method of non-contact electrocoagulation, using high frequency current by means of ionized argon gas (argon plasma). Recently, this technique has become available for flexible endoscopic delivery through special probes. Aim of this study is to evaluate the efficacy, indications and the possible side effects of APC use in the palliative treatment of malignant airway obstructions and/or bleeding. Over a 24-month period, 47 patients underwent APC treatment for malignant neoplasms of the tracheobronchial system causing obstruction and/or recurrent bleeding. Immediate airway patency and haemostasis were obtained in 91.5% of cases (43/47). No complications or side effects caused by the treatment were observed. In two patients, the treatment allowed a radical surgical approach after induction chemotherapy. In all cases, APC proved to be highly effective and easy to perform. In our experience, APC has proven to be easy to perform, rapidly effective, safe and well tolerated by the patient, even after repeated application. This study highlights the value of endoscopic APC in the palliative management of tracheobronchial neoplasms.

Cerebrospinal fluid concentration of fibronectin in meningitis.

Fibronectin concentrations in the cerebrospinal fluid were assessed in 20 patients with acute meningitis using a turbidimetric immunoassay. A significant increase in fibronectin concentrations was observed in patients with bacterial meningitis; decreased concentrations were observed in patients with viral meningitis. The determination of fibronectin concentration in patients with bacterial meningitis may represent a useful marker in differentiating bacterial from viral meningitis.