Outcomes associated with concordance of oral antidiabetic drug treatments to prescribing information in patients with type 2 diabetes mellitus and chronic kidney disease

OBJECTIVES

This retrospective study aims to examine the association between prescribing information (PI)-concordant oral antidiabetic drug (OAD) treatment and clinical and economic outcomes in patients with type 2 diabetes mellitus and stages 3-5 chronic kidney disease (CKD).

METHODS

The study used a large, national administrative claims database with laboratory findings to identify patients with a diagnosis of diabetes and indication of stages 3-5 CKD (first observed indication as the index date) between 1/1/2005 and 30/06/2009. OADs prescribed during 6 months following the index date (baseline period) were evaluated and patients were considered non-PI-concordant if any did not meet the recommendations regarding patients with renal impairment. Glycemic control and measures of healthcare costs (standardized to 2010 US dollars using the Consumer Price Index) and resource utilization were assessed during the 12 months following the baseline period. Severe hypoglycemic events were assessed after the baseline period until lost to follow-up. Regression analyses were performed after adjusting for demographic and clinical characteristics.

RESULTS

Among the 3300 patients included in the study, 2454 (74.4%) were non-PI-concordant. The non-PI-concordant patients had higher risk of severe hypoglycemic events identified in all settings (HR = 1.35, 95% CI: 1.10-1.67) and events identified in inpatient hospital setting (HR = 2.51, 95% CI: 1.49-4.22), were more likely to have inpatient hospital admissions (OR = 1.27, 95% CI: 1.02-1.57), and were less likely to have glycemic control (OR = 0.56, 95% CI: 0.44-0.71). Annual diabetes-related cost was $1638 higher in the non-PI-concordant cohort (p = 0.0048).

LIMITATION

The retrospective cohort design does not allow for conclusions to be drawn on the causal effect of PI-concordant use based on the associations observed.

CONCLUSION

Our findings suggest PI-concordant treatment to be associated with better clinical and diabetes-associated economic outcomes. Future research is warranted to confirm the associations found in this study.

Longitudinal patterns of analgesic and central acting drug use and associated effectiveness in fibromyalgia

BACKGROUND

We describe the changing pattern of analgesic and new central acting drug (NCAD) use (pregabalin, duloxetine, milnacipran) in fibromyalgia and measure NCAD effectiveness in clinical practice.

METHODS

About 3123 US adult patients with fibromyalgia participated in an 11-year longitudinal study of fibromyalgia outcomes. We assessed severity-adjusted treatment prevalence and measured the effect of any use of NCAD on pain and fatigue, and functional status using the Health Assessment Questionnaire (HAQ) disability index.

RESULTS

In 2010, 46.7% of patients used opioids, including 12.5% who used strong opioids. During the 11 years, severity-adjusted strong opioid use increased from 6.3% to 11.7% and any opioid use from 40.0% to 46.6%. Nonsteroidal anti-inflammatory drug (NSAID) use decreased from 74% to 44%. Tricyclic use dropped in half, from 27% to 15%, while NCAD use increased from less than 10% to 39%. The estimated 25th and 50th percentiles for NCAD discontinuation time were 1 and 2.5 years. Overall pain, fatigue and HAQ scores were unchanged over the 11 years. For patients treated with NCAD, pain scores were reduced significantly by 0.17 (0.03, 0.30) units following the start of NCAD, an improvement of 2.8%. Some sensitivity analyses showed improvements of up to 4.3%. There was no significant improvement in fatigue or functional status.

CONCLUSIONS

There is a changing pattern of drug treatment in fibromyalgia, consisting mostly of decreased NSAID and amitriptyline use and an increase in NCAD. Drug costs are substantially higher because of NCAD use, but we found no evidence of clinical benefit for NCAD compared with prior therapy.

Initial Experience With the Wavelight Refractive Suite for Myopic Laser In Situ Keratomileusis

PURPOSE

The objective of this study was to describe our initial experience with the newest refractive platform, the Wavelight Refractive Suite.

DESIGN

This was a consecutive case series of first 50 eyes that underwent myopic laser in situ keratomileusis.

METHODS

A total of 50 myopic eyes (28 patients) were included in this study. Uncorrected distance visual acuity, manifest refraction, and keratometry readings were taken preoperatively and 3 months postoperatively. Emmetropia was targeted with an optical zone of 6.5 mm, and flap dimensions were of 130-μm thickness and 9-mm diameter with a superior hinge in all eyes. Flap thickness was measured with optical coherence tomography postoperatively.

RESULTS

At 3 months postoperatively, 82% (41/50) of eyes achieved uncorrected distance visual acuity of 6/6 or better, 98% (49/50) achieved 6/9 or better, and all eyes achieved 6/12 or better. Eighty-four percent of eyes were within 0.5 diopter (D) of target of emmetropia, and 98% of eyes were within 1 D. Mean postoperative flap thickness was 124 ± 7.8 μm.

CONCLUSIONS

The Wavelight Refractive Suite consisting of the femtosecond laser FS200 and Excimer laser EX500 is the newest integrated refractive surgical platform available and can offer good refractive predictability as shown by the results in our initial 50 myopic eyes.

Perilipin polymorphism interacts with saturated fat and carbohydrates to modulate insulin resistance

BACKGROUND AND AIMS

Macronutrient intakes and genetic variants have been shown to interact to alter insulin resistance, but replications of gene-nutrient interactions across independent populations are rare, despite their critical importance in establishing credibility. We aimed to investigate a previously demonstrated saturated fat and carbohydrate interaction for insulin resistance for perilipin (PLIN1), a regulator of adipocyte metabolism.

METHODS AND RESULTS

We investigated the previously shown interaction for PLIN1 11482G > A (rs894160) on insulin resistance in US men (n = 462) and women (n = 508) (mean ± SD, 49 ± 16 years). In multivariable linear regression models, we found an interaction (P < 0.05) between the ratio of saturated fat to carbohydrate intake as a continuous variable and PLIN1 11482G > A for HOMA-IR (homeostasis model assessment of insulin resistance) in women. For carriers of the minor allele but not for non-carriers, as the ratio of saturated fat to carbohydrate intake increased, predicted HOMA-IR increased (P = 0.002). By dichotomizing the ratio of saturated fat to carbohydrate intake into high and low, we found significant interaction terms for insulin and HOMA-IR (P < 0.05). When the ratio of saturated fat to carbohydrate was high, insulin and HOMA-IR were higher in minor allele carriers (P = 0.004 and P = 0.003, respectively), but did not differ when the ratio was low. Similar patterns or trends were observed when saturated fat and carbohydrate were dichotomized into high and low as individual macronutrients.

CONCLUSIONS

Replication of the previously reported interaction between macronutrient intakes and PLIN1 genotype for insulin resistance reinforces the potential usefulness of applying genotype information in the dietary management of insulin resistance.

Rationalization and design of the complementarity determining region sequences in an antibody-antigen recognition interface

Protein-protein interactions are critical determinants in biological systems. Engineered proteins binding to specific areas on protein surfaces could lead to therapeutics or diagnostics for treating diseases in humans. But designing epitope-specific protein-protein interactions with computational atomistic interaction free energy remains a difficult challenge. Here we show that, with the antibody-VEGF (vascular endothelial growth factor) interaction as a model system, the experimentally observed amino acid preferences in the antibody-antigen interface can be rationalized with 3-dimensional distributions of interacting atoms derived from the database of protein structures. Machine learning models established on the rationalization can be generalized to design amino acid preferences in antibody-antigen interfaces, for which the experimental validations are tractable with current high throughput synthetic antibody display technologies. Leave-one-out cross validation on the benchmark system yielded the accuracy, precision, recall (sensitivity) and specificity of the overall binary predictions to be 0.69, 0.45, 0.63, and 0.71 respectively, and the overall Matthews correlation coefficient of the 20 amino acid types in the 24 interface CDR positions was 0.312. The structure-based computational antibody design methodology was further tested with other antibodies binding to VEGF. The results indicate that the methodology could provide alternatives to the current antibody technologies based on animal immune systems in engineering therapeutic and diagnostic antibodies against predetermined antigen epitopes.

Efficacy of leukotriene receptor antagonist for erosive esophagitis: a preliminary retrospective comparative study

While diagnostic overlap exists between gastroesophageal reflux disease and eosinophilic esophagitis especially on histological findings, therapeutic approaches for the two disease entities are very different. Recently, anti-inflammatory treatment, in addition to acid suppressants, has been investigated for gastroesophageal reflux disease. This study investigated whether the incidence of endoscopic erosive esophagitis was lower in recipients of long-term leukotriene receptor antagonist (LTRA) treatment. This retrospective comparative study included 207 recipients of an LTRA and an equal number of controls who underwent screening upper endoscopic examination. Twenty-two (10.6%) and 51 (24.6%) cases of erosive esophagitis were detected in the LTRA and control groups, respectively (P < 0.001). A significantly higher incidence of minimal change esophagitis was also found in the controls compared with the LTRA group (14.5% vs. 2.4%, P < 0.001). On multivariate analysis, LTRA treatment was significantly and inversely associated with erosive esophagitis (odds ratio [OR], 0.25; 95% confidence interval [CI], 0.13 to 0.46). Within the LTRA treatment group, an increased risk of erosive esophagitis was strongly associated with the presence of hiatal hernia (OR, 5.89; 95% CI, 2.20-15.73, P < 0.001) and short duration of LTRA treatment (OR, 0.64; 95% CI, 0.37-0.89, P= 0.022). In conclusion, this preliminary retrospective analysis demonstrated that patients who underwent long-term treatment with a LTRA had low incidence of endoscopic minimal change esophagitis.

Al2O3 and TiO2 atomic layer deposition on copper for water corrosion resistance

Al(2)O(3) and TiO(2) atomic layer deposition (ALD) were employed to develop an ultrathin barrier film on copper to prevent water corrosion. The strategy was to utilize Al(2)O(3) ALD as a pinhole-free barrier and to protect the Al(2)O(3) ALD using TiO(2) ALD. An initial set of experiments was performed at 177 °C to establish that Al(2)O(3) ALD could nucleate on copper and produce a high-quality Al(2)O(3) film. In situ quartz crystal microbalance (QCM) measurements verified that Al(2)O(3) ALD nucleated and grew efficiently on copper-plated quartz crystals at 177 °C using trimethylaluminum (TMA) and water as the reactants. An electroplating technique also established that the Al(2)O(3) ALD films had a low defect density. A second set of experiments was performed for ALD at 120 °C to study the ability of ALD films to prevent copper corrosion. These experiments revealed that an Al(2)O(3) ALD film alone was insufficient to prevent copper corrosion because of the dissolution of the Al(2)O(3) film in water. Subsequently, TiO(2) ALD was explored on copper at 120 °C using TiCl(4) and water as the reactants. The resulting TiO(2) films also did not prevent the water corrosion of copper. Fortunately, Al(2)O(3) films with a TiO(2) capping layer were much more resilient to dissolution in water and prevented the water corrosion of copper. Optical microscopy images revealed that TiO(2) capping layers as thin as 200 Å on Al(2)O(3) adhesion layers could prevent copper corrosion in water at 90 °C for ~80 days. In contrast, the copper corroded almost immediately in water at 90 °C for Al(2)O(3) and ZnO films by themselves on copper. Ellipsometer measurements revealed that Al(2)O(3) films with a thickness of ~200 Å and ZnO films with a thickness of ~250 Å dissolved in water at 90 °C in ~10 days. In contrast, the ellipsometer measurements confirmed that the TiO(2) capping layers with thicknesses of ~200 Å on the Al(2)O(3) adhesion layers protected the copper for ~80 days in water at 90 °C. The TiO(2) ALD coatings were also hydrophilic and facilitated H(2)O wetting to copper wire mesh substrates.

Use of Laryngeal Mask Airway and Its Removal in a Deeply Anaesthetized State Reduces Emergence Agitation after Sevoflurane Anaesthesia in Children

This study investigated the effect of laryngeal mask airway (LMA) and removal while in a deeply anaesthetized state (deep removal) compared with endotracheal tube and extubation when awake or deeply anaesthetized on the incidence of emergence agitation in children after sevoflurane anaesthesia for subumbilical surgery. Patients (2 – 7 years) were randomly assigned to one of three groups: ET-A group ( n = 56, endotracheal tube and extubation whilst awake); ET-D group ( n = 56, endotracheal tube and deep extubation); LMA-D group (n = 56, experienced LMA and deep removal). The incidence of postoperative emergence agitation was significantly lower in the LMA-D patients compared with patients in the ET-A group (21.4% and 41.1%, respectively). Patients in the LMA-D group required a significantly shorter stay in the postanaesthetic care unit (PACU) than ET-A patients. There were no significant differences in the incidence of postoperative emergence agitation or length of stay in the PACU between the ETA and ET-D groups, or between the ET-D and LMA-D groups. In conclusion, using an LMA and deep removal decreased postoperative emergence agitation compared with using an endotracheal tube and awake extubation after paediatric sevoflurane anaesthesia.

Femtosecond high-power spontaneous mode-locked operation in vertical-external cavity surface-emitting laser with gigahertz oscillation

We realize a femtosecond high-power spontaneous mode-locked operation with gigahertz oscillation in a vertical-external cavity surface-emitting laser under the condition of eliminating the internal and external unwanted reflection. We find that the reflectivity of the output coupler has a significant influence not only on the output power but also on the output pulse duration. With an incident pump power of 20 W, we have achieved 2.35 W of average output power with 778 fs pulse duration at a repetition rate of 2.17 GHz. The shortest pulse duration was 654 fs at an average output power of 0.45 W.

Precise measurement of group refractive indices and temperature dependence of refractive index for Nd-doped yttrium orthovanadate by intracavity spontaneous mode locking

We report on a novel method based on intracavity spontaneous mode locking to precisely measure the group refractive indices and temperature dependence of refractive index of Nd:YVO(4) crystal at the wavelength of 1064 nm. All the experimental results are found to agree very well with the most recent measured values. We also confirm that the developed method is applicable to measuring the group refractive indices and the temperature dependence of the refractive indices of other vanadate crystals, as well as nonlinear crystals.

Axo-axonal interaction in autonomic regulation of the cerebral circulation

Noradrenaline (NE) and acetylcholine (ACh) released from the sympathetic and parasympathetic neurones in cerebral blood vessels were suggested initially to be the respective vasoconstricting and dilating transmitters. Both substances, however, are extremely weak post-synaptic transmitters. Compelling evidence indicates that nitric oxide (NO) which is co-released with ACh from same parasympathetic nerves is the major transmitter for cerebral vasodilation, and its release is inhibited by ACh. NE released from the sympathetic nerve, acting on presynaptic β2-adrenoceptors located on the neighbouring parasympathetic nitrergic nerves, however, facilitates NO release with enhanced vasodilation. This axo-axonal interaction mediating NE transmission is supported by close apposition between sympathetic and parasympathetic nerve terminals, and has been shown in vivo at the base of the brain and the cortical cerebral circulation. This result reveals the physiological need for increased regional cerebral blood flow in 'fight-or-flight response' during acute stress. Furthermore, α7- and α3β2-nicotinic ACh receptors (nAChRs) on sympathetic nerve terminals mediate release of NE, leading to cerebral nitrergic vasodilation. α7-nAChR-mediated but not α3β2-nAChR-mediated cerebral nitrergic vasodilation is blocked by β-amyloid peptides (Aβs). This may provide an explanation for cerebral hypoperfusion seen in patients with Alzheimer's disease. α7- and α3β2-nAChR-mediated nitrergic vasodilation is blocked by cholinesterase inhibitors (ChEIs) which are widely used for treating Alzheimer's disease, leading to possible cerebral hypoperfusion. This may contribute to the limitation of clinical use of ChEIs. ChEI blockade of nAChR-mediated dilation like that by Aβs is prevented by statins pretreatment, suggesting that efficacy of ChEIs may be improved by concurrent use of statins.

Effects of signal sequence on phage-displayed disulfide-stabilized single chain antibody variable fragment (sc-dsFv) libraries

Phage-displayed single chain variable fragment (scFv) libraries are powerful tools in antibody engineering. Disulfide-stabilized scFv (sc-dsFv) with an interface disulfide bond is structure-wise more stable than the corresponding scFv. A set of recently discovered signal sequences replacing the wild type (pelB) signal peptidase cleavage site in the c-region has been shown to be effective in rescuing the expression of sc-dsFv libraries on the phage surface. However, the effects of the other regions of the signal sequence on the expression of the sc-dsFv libraries and on the formation of the interface disulfide bond in the phage-displayed sc-dsFv have not been clear. In this work, selected novel signal sequence variants in the h-region were shown to be equally effective in promoting sc-dsFv library expression on the phage surface; the expression level and complexity of the sc-dsFv libraries were comparable to the corresponding scFv libraries produced with the wild-type (pelB) signal sequence. The interface disulfide bond in the phage-displayed sc-dsFv was proven to form to a large extent in the library variant ensemble generated with signal sequence variants in both the h-region and the c-region. The sc-dsFv engineering platform established in this work can be applied to many of the known scFv molecules which are in need of a more stable version for the applications under harsh conditions or for longer shelf-life.

Routine drainage is not necessary after laparoscopic gastric bypass

INTRODUCTION

Routine intra-abdominal drainage has been recommended for detecting surgical complications, such as anastomotic leaks or intra-abdominal hemorrhage, after laparoscopic gastric bypass for morbid obesity. The aim of this study was to determine whether routine drainage after laparoscopic gastric bypass is indeed necessary.

METHODS

Patients undergoing laparoscopic gastric bypass with intra-abdominal drainage (D-group) were compared with those without drainage (N-group) in a retrospective study. The main outcome measures were postoperative course and complications.

RESULTS

No differences were observed in the postoperative complications. Both groups had one major complication of leakage (1/90, 1.1%). Minor complications occurred in six D-group patients (6/90, 6.7%) and eight N-group patients (8/90, 8.9%) (P=0.578). No difference was observed in postoperative analgesic dose usage (mean ± SD: 63 ± 37 mg vs 60 ± 31 mg; P=0.963) or length of stay hospital (5.2 ± 2.6 d vs 4.7 ± 1.8 d; P=0.135). However, the N-group had a shorter time to flatus passage compared to the D-group (1.6 ± 0.7 d vs 1.2 ± 0.5 d; P=0.006).

CONCLUSION

Routine abdominal drainage is not necessary after a successful laparoscopic gastric bypass for morbidly obese patients. Drainage omission may contribute to a quicker recovery without additional surgical complications.

Is minimal change esophagitis really part of the spectrum of endoscopic findings of gastroesophageal reflux disease? A prospective, multicenter study

BACKGROUND AND STUDY AIMS

Although minimal changes are one of the endoscopic findings of nonerosive reflux disease (NERD), the clinical significance of minimal changes is controversial. This study evaluated the clinical significance of minimal changes and examined whether such changes have diagnostic value in gastroesophageal reflux disease (GERD).

PATIENTS AND METHODS

The endoscopic findings were assessed from 1445 patients identified as having minimal changes who were seen across 30 institutions between April and September 2009. Six endoscopic criteria reported to have acceptable-to-good agreement between endoscopists were used for assessing minimal changes: erythema, blurring of the Z-line, friability, decreased vascularity, white turbid discoloration, and edema or accentuation of the mucosal folds. The diagnosis of GERD was based on the GerdQ, a questionnaire for identifying GERD among patients with upper gastrointestinal symptoms.

RESULTS

Of the 1445 patients, 44.5 % were categorized into the GERD group based on the GerdQ. No significant differences in clinical characteristics were found between the GERD and non-GERD groups, except in age and height. Blurring of the Z-line and erythema were the most common endoscopic findings of minimal changes in this study. Only one of the six findings (16.7%) was more common in the GERD group than in the non-GERD group. Using more than one endoscopic finding was not more useful for identifying GERD than using only one endoscopic finding.

CONCLUSIONS

Most of the endoscopic findings indicating minimal changes are not associated with GERD. The clinical significance of minimal changes should be reconsidered.

GaN nanowire functionalized with atomic layer deposition techniques for enhanced immobilization of biomolecules

We report the use of atomic layer deposition (ALD) coating as a nanobiosensor functionalization strategy for enhanced surface immobilization that may enable higher detection sensitivity. Three kinds of ALD coating films, Al(2)O(3), TiO(2), and SiO(2), were grown on the gallium nitride nanowire (GaN NW) surfaces and characterized with high-resolution transmission electron microscopy (HRTEM) and vacuum Fourier transform infrared spectroscopy (FTIR). Results from HRTEM showed that the thicknesses of ALD-Al(2)O(3), ALD-TiO(2) and ALD-SiO(2) coatings were 4-5 nm, 5-6 nm, and 12-14 nm, respectively. Results from FTIR showed that the OH contents of these coatings were, respectively, ∼6.9, ∼7.4, and ∼9.3 times that of piranha-treated GaN NW. Furthermore, to compare protein attachments on the different surfaces, poly(ethylene glycol) (PEG)-biotin was grafted on the OH-functionalized GaN NW surfaces through active Si-Cl functional groups. Streptavidin protein molecules were then attached to the biotin ends via specific binding. The immobilized streptavidin molecules were examined with scanning electron microscopy, HRTEM, and fluorescent imaging. Results from HRTEM and energy-dispersive X-ray revealed that the nitrogen concentrations on the three ALD coatings were significantly higher than that on the piranha-treated surface. Results from fluorescent imaging further showed that the protein attachments on the Al(2)O(3), TiO(2), and SiO(2) ALD coatings were, respectively, 6.4, 7.8, and 9.8 times that of piranha-treated surface. This study demonstrates that ALD coating can be used as a functionalization strategy for nanobiosensors because it is capable of creating functional groups with much higher density compared to widely used acid modifications, and among the three ALD coatings, ALD-SiO(2) yielded the most promising results in OH content and protein attachment.

Using autocloning effects to develop broad-bandwidth, omnidirectional antireflection structures for silicon solar cells

In this study, we used the autocloning effect on pyramid structures to develop broad-bandwidth, omnidirectional antireflection structures for silicon solar cells. The angular dependence of reflectance on several pyramid structures was systematically investigated. The deposition of three-layer autocloned films reduced the refractive index gap between air and silicon, resulting in an increase in the amount of transmitted light and a decrease in the total light escaping. The average reflectance decreased dramatically to ca. 2-3% at incident angles from 0 to 60° for both sub-wavelength- and micrometer-scale pyramid structures. The measured reflectance of the autocloned structure was less than 4% in the wavelength range from 400 to 1000 nm for incident angles from 0 to 60°. Therefore, the autocloning technique, combined with optical thin films and optical gradient structures, is a practical and compatible method for the fabrication of broad-bandwidth, omnidirectional antireflection structures on silicon solar cells.

Histologic diagnosis based on forceps biopsy is not adequate for determining endoscopic treatment of gastric adenomatous lesions

BACKGROUND AND STUDY AIMS

Controversy persists around the treatment of gastric low-grade dysplasia (LGD). The aim of this study was to investigate possible indications for the endoscopic resection of gastric LGD through analysis of the histologic discrepancies between specimens of gastric LGD obtained by forceps biopsy and by endoscopic mucosal resection (EMR), and of their clinicopathologic characteristics.

PATIENTS AND METHODS

The study involved 293 gastric LGD that were histologically proven on the basis of forceps biopsy in Severance Hospital between January 2004 and December 2007. Twenty cases were regularly followed up, and the remaining 273 were resected by EMR. We performed univariate and multivariate analyses of clinical and endoscopic characteristics including lesion size, number of biopsy fragments, and endoscopic appearance, in order to analyze the factors affecting histologic discrepancies.

RESULTS

Of the 273 lesions resected by EMR, 207 (75.8 %) showed concordant histology, whereas for 51 (18.7 %) the histology was upgraded after endoscopic resection. Lesion size, absence of whitish discoloration, and the presence of spontaneous bleeding were found by univariate analysis to be statistically significant factors predicting an upgraded histology after EMR ( P = 0.026, P < 0.001, and P = 0.025, respectively). Multivariate analysis also showed absence of whitish discoloration to be a statistically significant factor influencing histologic discrepancies ( P = 0.001, odds ratio 5.29, 95 % confidence interval 1.95 - 14.37). Perforation and bleeding rates associated with EMR for LGD were 0.7 % and 6.2 %, respectively. Twenty patients who did not undergo EMR were followed up for a mean of 22 months, and 3 were revealed to have adenocarcinoma and 1 high-grade dysplasia on the latest histologic exam.

CONCLUSIONS

We should consider endoscopic resection for gastric LGD that are 2 cm or more in size and do not have whitish discoloration.

Narrow-band imaging with magnifying endoscopy for the screening of esophageal cancer in patients with primary head and neck cancers

BACKGROUND AND STUDY AIM

Although narrow-band imaging (NBI) in endoscopy can improve detection of early-stage esophageal malignancies in patients with head and neck cancers, false-positive results may be obtained in areas with nonspecific inflammatory changes. This study evaluated the feasibility of primary screening with NBI and magnification for the presence of esophageal malignancies in these cancer patients.

PATIENTS AND METHODS

Sixty-nine patients with documented head and neck cancers were enrolled from April 2008 to January 2009. All patients underwent a meticulous endoscopic examination of the esophagus using a conventional white-light system followed by re-examination using the NBI system and final confirmation with NBI plus magnification.

RESULTS

Twenty-one patients (30.4 %) were confirmed to have esophageal neoplasia. Among these 21, 16 (76.2 %) had synchronous lesions, 9 (42.9 %) were asymptomatic, and 10 (47.6 %) had early-stage neoplasia. The incidence of multiple esophageal neoplasia was 57.1 %. NBI was more effective than conventional endoscopy in detecting neoplastic lesions (35 lesions in 21 patients vs. 22 lesions in 18 patients) and was particularly effective in patients with dysplasia (13 lesions in 9 patients vs. 3 lesions in 3 patients). The sensitivity and accuracy of detection were 62.9 % and 64.4 % for conventional endoscopy, 100 % and 86.7 % for NBI alone, and 100 % and 95.6 % for NBI with high magnification, respectively.

CONCLUSIONS

Compared with current approaches, NBI followed by high magnification significantly increases the accuracy of detection of esophageal neoplasia in patients with head and neck cancers. The result warrants conducting prospective randomized controlled study to confirm its efficacy.

Generation and characterization of anti-alpha-enolase single-chain antibodies in chicken

It was previously reported that up-regulation of α-enolase protein was detected in 65% of patients with non-small cell lung cancers (NSCLC). Moreover, a high titer of anti-α-enolase antibodies was developed in a smaller proportion (7.4%) of these patients than in non-tumor-associated patients and healthy subjects. In the present study, we characterized polyclonal and single-chain variable fragment (scFv) anti-α-enolase antibodies from immunized chickens. The E. coli-derived recombinant α-enolase protein was purified to its high homogenicity as verified by SDS-PAGE. After the 4th immunization, a high titer of specific polyclonal anti-α-enolase antibodies was elicited in immunized chickens and specifically recognized the purified human α-enolase antigen as determined by Western blot and ELISA. The expressed heavy and light chain variable genes (VH and VL) were isolated from spleen B cells and amplified to construct phage antibody libraries containing scFv molecules. After four rounds of panning selection, the scFv antibodies of randomly chosen clones were expressed and their binding specificity to α-enolase protein was verified using competitive ELISA, flow cytometry and immunofluorescence staining. Nucleotide sequence analysis from 10 α-enolase binding clones showed that 3 (30%) clones used identical heavy and light genes for scFv antibody expression, as represented by EnL5. Notably, amino acid changes in complementarity-determining regions (CDRs) were more frequently observed than those in framework regions (FRs) in all clones, indicating a strong affinity selection through mutations. All together, it is believed that these polyclonal and scFv IgY antibodies may be helpful in the development of molecular diagnostic and therapeutic agents for lung cancers in the future.

Signal sequence as a determinant in expressing disulfide-stabilized single chain antibody variable fragments (sc-dsFv) against human VEGF

Phage-displayed single chain variable fragment (scFv) libraries have been powerful tools in antibody engineering. But the scFv structures are frequently unstable due to the dissociation of the dimeric interface between the two variable domains. One solution is the sc-dsFv construct, where the single chain variable domain fragment is stabilized with an additional interface disulfide bond, leading to stable and homogeneous dimeric interface for the sc-dsFv structure. However, the phagemid system that is capable of effective expression for both sc-dsFv-pIII fusion proteins on phage surface and secreted non-fusion sc-dsFv in bacterial culture medium has not been demonstrated. In this work, a biological combinatorial approach was applied to optimize the signal sequence N-terminal to the sc-dsFv-pIII fusion protein encoded in a phagemid. The optimized sc-dsFv phage display systems were compatible with both the phage-based directed evolution procedure and the high throughput screening of the soluble sc-dsFv. The utility of the phagemid systems was demonstrated in generating anti-VEGF sc-dsFv with VEGF-binding affinity one order of magnitude higher than the corresponding scFv, due only to the interface disulfide bond in the sc-dsFv. Moreover, the protein stability of the sc-dsFv construct was unmatched by the corresponding scFv. These advantages of the sc-dsFv were gained through the interface disulfide bond of the sc-dsFv and the novel signal sequence in the phagemid.

Phosphoinositide 3-kinase δ inhibitor suppresses interleukin-17 expression in a murine asthma model

Phosphoinositide 3-kinases (PI3Ks) contribute to the pathogenesis of asthma by regulating the activation of inflammatory mediators, inflammatory cell recruitment and immune cell function. Recent findings have indicated that PI3Ks also regulate the expression of interleukin (IL)-17, which has been recognised as an important cytokine involved in airway inflammation. In the present study, we investigated a role of PI3Kδ in the regulation of IL-17 expression in allergic airway disease using a murine model of asthma. After ovalbumin inhalation, administration of a selective p110δ inhibitor, IC87114, significantly attenuated airway infiltration of total cells, lymphocytes, neutrophils and eosinophils, as well as airway hyperresponsiveness, and attenuated the increase in IL-17 protein and mRNA expression. Moreover, IC87114 reduced levels of IL-4, -5 and -13, expression of keratinocyte chemoattractant protein and mRNA, and nuclear factor (NF)-κB activity. In addition, a NF-κB inhibitor, BAY 11-7085 substantially reduced the increase in IL-17 protein levels. Our results also showed that inhibition of IL-17 activity with an anti-IL-17 antibody remarkably reduced airway inflammation and hyperresponsiveness. These findings suggest that inhibition of the p110δ signalling pathway suppresses IL-17 expression through regulation of NF-κB activity and, thus, has therapeutic potential in asthma.

A comparison of different electrostatic potentials on prediction accuracy in CoMFA and CoMSIA studies

Computational chemistry is playing an increasingly important role in drug design and discovery, structural biology, and quantitative structure-activity relationship (QSAR) studies. For QSAR work, selecting an appropriate and accurate method to assign the electrostatic potentials of each atom in a molecule is a critical first step. So far several commonly used methods are available to assign charges. However, no systematic comparison of the effects of electrostatic potentials on QSAR quality has been made. In this study, twelve semi-empirical and empirical charge-assigning methods, AM1, AM1-BCC, CFF, Del-Re, Formal, Gasteiger, Gasteiger-Hückel, Hückel, MMFF, PRODRG, Pullman, and VC2003 charges, have been compared for their performances in CoMFA and CoMSIA modeling using several standard datasets. Some charge assignment models, such as Del-Re, PRODRG, and Pullman, are limited to specific atom and bond types, and, therefore, were excluded from this study. Among the remaining nine methods, the Gasteiger-Hückel charge, though commonly used, performed poorly in prediction accuracy. The AM1-BCC method was better than most charge-assigning methods based on prediction accuracy, though it was not successful in yielding overall higher cross-validation correlation coefficient (q(2)) values than others. The CFF charge model worked the best in prediction accuracy when q(2) was used as the evaluation criterion. The results presented should help the selection of electrostatic potential models in CoMFA and CoMSIA studies.