Patterns of lymph node sampling and the impact of lymph node density in favorable histology Wilms tumor: An analysis of the national cancer database

INTRODUCTION

There is controversy about the role of lymph node (LN) sampling or dissection in the management of favorable histology (FH) Wilms tumor (WT), specifically how it performed and how it may impact survival.

OBJECTIVE

The objective of this study was to analyze factors affecting LN sampling patterns and the impact of LN yield and density (number of positive LNs/LNs examined) on overall survival (OS) in patients with advanced-stage favorable histology Wilms tumor (FHWT).

METHODS

The National Cancer Database (NCDB) was queried for patients with FHWT during 2004-2013. Demographic, clinical and OS data were abstracted for those who underwent surgical resection. Poisson regression was performed to analyze how factors influenced LN yield. Patients with positive LNs had LN density calculated and were further analyzed.

RESULTS

A total of 2340 patients met criteria, with a median age at diagnosis of 3 years (range 0-78 years). The median number of LNs examined was three (range 0-87). Lymph node yield was affected by age, race, insurance, tumor size, laterality, advanced stage, LN positivity, and institutional volume. A total of 390 (16.6%) patients had LN-positive disease. Median LN density for these LN-positive patients was 0.38 (range 0.02-1) (Summary Figure). Estimated 5-year OS was significantly improved for those with LN density ≤0.38 vs. >0.38 (94% vs. 84.6%, P = 0.012). In this population, on multivariate analysis, age and LN density were significant predictors of OS.

DISCUSSION

It is difficult to compile large numbers of cases in rare diseases like WT, and fortunately a large administrative database such as the NCDB can serve as a great resource. However, administrative data come with inherent limitations such as missing data and inability to account for a variety of factors that may influence LN yield and/or OS (specimen designation, pathologist experience, surgeon experience/volume, institutional Children's Oncology Group (COG) association, etc.). In this specific disease, the American Joint Committee on Cancer staging (captured by the NCDB) is different than the COG WT staging system that is used clinically, and the NCDB does not capture oncologic outcomes beyond OS.

CONCLUSIONS

In a review of the NCDB, various factors associated with LN yield and observed LN density were identified to be significantly associated with OS in patients with LN-positive FHWT. This reinforces the need for adequate LN sampling at the time of WT surgery, to maximize surgical disease control. It was proposed that LN density as a metric may allow for improved risk-stratification, and possibly allow for therapeutic reduction in a sub-set of patients with low LN density.

Genotyping and Phylogenetic Analysis of Group B Streptococcus by Multiple Locus Variable Number Tandem Repeat Analysis in Iran

Background:

Group B streptococcus (GBS), also known as Streptococcus agalactiae, is well known as a causative agent for neonatal invasive diseases; it is also a major pathogen in adults. Analytic epidemiology is required to monitor the clinical isolates of GBS. However, there is insufficient information on the genetic background of GBS in Iran, and this information is needed to guide and develop a GBS vaccine.

Materials and Methods:

In total, 90 well-char - acterized GBS isolates were collected from April 2014 to August 2015. In this study, molecular typing was used to disclose a relationship between the multiple-locus variable number tandem repeat analysis (MLVA) types, serotyping, and pilus islands. The isolates were characterized by the types of capsular polysaccharides and pilus islands and were examined by MLVA to study the epidemiological relationship of isolates.

Results:

The results indicate that there is a significant relationship between the distribution of serotypes and pilus island genes; GBS isolates were differentiated into 12 types by capsular polysaccharides and pilus islands analysis. The discriminatory power of an MLVA analysis was high based on the five most variable numbers of tandem repeat loci and 44 MLVA types that were identified.

Conclusion:

This study has provided useful insights into the genetic heterogeneity of GBS isolates in Tehran and Alborz, Iran. The extensive distribution of pilus islands in various serotypes and MLVA types throughout the GBS population refers to the advancement of the pilus-based GBS vaccines.

Pilus-encoding islets in S. agalactiae and its association with antibacterial resistance and serotype distribution

Group B Streptococcus (GBS) is a versatile organism which uses multiple virulence factors which bind to the surface of epithelial cells. Pili are one of virulence factors detected in recent years. A total of 90 isolates were collected from invasive and non-invasive isolates among adults throughout 2014-2015. Isolates were serotyped at molecular level based on capsular polysaccharide (cps) serotyping and analyzed for pilus island profiles, scpB gene, and hvgA gene presence. Isolates were subjected to antimicrobial susceptibility towards penicillin, tetracycline, erythromycin, clindamycin, moxifloxacin, levofloxacin, and vancomycin by disk diffusion method and MICs for erythromycin and clindamycin were determined by broth dilution methods. Overall, 4 serotypes were identified, serotype III (68.88%), V (20%), II (10%) and Ib (1.11%) and hvgA gene was detected in 7.7% (n = 7) of the isolates; all were serotype III/ST 17. All isolates were susceptible to penicillin and vancomycin, except one isolate which showed intermediate resistance to penicillin and other complete resistance to vancomycin. Isolates were resistant to tetracycline (98%), erythromycin (25%), clindamycin (22%), moxifloxacin (8%), and levofloxacin (6%). The scpB gene was detected in all isolates, while isolates harbored at least one PI, of which the PI-1+PI-2a was the most frequent combination observed. Our data show the presence of the relation between serotype or pilus genes among clinical isolates of Streptococcus agalactiae. These data are principal to help in designing prevention and treatment strategies for GBS infections in the region.

Twin Defect Derived Growth of Atomically Thin MoS2 Dendrites

Morphology management for tailoring the properties of monolayer transition-metal dichalcogenides (TMDCs), that is, molybdenum disulfide (MoS₂), has attracted great interest for promising applications such as in electrocatalysis and optoelectronics. Nevertheless, little progress has been made in engineering the shape of MoS₂. Herein, we introduce a modified chemical vapor deposition method to grow monolayer MoS₂ dendrites by pretreating substrates with adhesive tapes. The as-grown MoS₂ crystals are featured with hexagonal backbones with fractal shapes and tunable degrees. By characterizing the atomic structure, it is found that these morphologies are mainly initiated from the twin defect derived growth and controlled by the S:Mo vapor ratio. Due to the accumulated sulfur vacancies in the cyclic twin regions, strong enhancement of photoluminescence emission is localized, which determines the shape dependency of optical property. This work not only enriches the understanding of the twin defects derived crystal growth mechanism and extends its applications from nanomaterials to two-dimensional crystals, but also offers a robust and controllable protocol for shape-engineered monolayer TMDCs in electrochemical and optoelectronic applications.

Natural phosphate-supported Cu(ii), an efficient and recyclable catalyst for the synthesis of xanthene and 1,4-disubstituted-1,2,3-triazole derivatives

Cu(NO₃)₂ supported on natural phosphate, Cu(ii)/NP, was prepared by co-precipitation and applied as a heterogeneous catalyst for synthesizing xanthenes (2–3 h, 85–97%) through Knoevenagel–Michael cascade reaction of aromatic aldehydes with 1,3-cyclic diketones in ethanol under refluxing conditions. It was further used for regioselective synthesis of 1,4-disubstituted-1,2,3-triazoles (1–25 min, 95–99%) via a three-component reaction between organic halides, aromatic alkynes and sodium azide in methanol at room temperature. The proposed catalyst, Cu(ii)/NP, was characterized using X-ray fluorescence, X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy, Brunauer–Emmett–Teller, Barrett–Joyner–Halenda and inductively coupled plasma analyses. Compared to other reports in literature, the reactions took place through a simple co-precipitation, having short reaction time (<3 hours), high reaction yield (>85%), and high recyclability of catalyst (>5 times) without significant decrease in the inherent property and selectivity of catalyst. The proposed protocols provided significant economic and environmental advantages.

Cu(NO₃)₂ supported on natural phosphate, Cu(ii)/NP, was prepared by co-precipitation and characterized. The Cu(ii)/NP catalyzed the synthesis of xanthenes and triazoles. The proposed protocols provided significant economic and environmental advantages.

Biosynthesis of Silver Nanoparticles Using Pine Pollen and Evaluation of the Antifungal Efficiency

Background: Nanoparticles have been applied to medicine, hygiene, pharmacy and dentistry, and will bring significant advances in the prevention, diagnosis, drug delivery and treatment of disease. Green synthesis of metal nanoparticles has a very important role in nanobiotechnology, allowing production of non-toxic and eco-friendly particles. Objectives: Green synthesis of silver nanoparticles (AgNPs) was studied using pine pollen as a novel, cost-effective, simple and non-hazardous bioresource. The antifungal activity of the synthesized AgNPs was investigated in vitro. Materials and Methods: Biosynthesis of AgNPs was conducted using pollen of pine (as a novel bioresource) acting as both reducing and capping agents. AgNPs were characterized using UV-visible spectroscopy, X-ray diffraction and transmission electron microscopy. In evaluation for antifungal properties, the synthesized AgNPs represented significant in vitro inhibitory effects on Neofusicoccum parvum cultures. Results: Pine pollen can mediate biosynthesis of colloidal AgNPs with an average size of 12 nm. AgNPs were formed at 22 °C and observed to be highly stable up to three months without precipitation or decreased antifungal property. AgNPs showed significant inhibitory effects against Neofusicoccum parvum. Conclusion: The first report for a low-cost, simple, well feasible and eco-friendly procedure for biosynthesis of AgNPs was presented. The synthesized AgNPs by pine pollen were nontoxic and eco-friendly, and can be employed for large-scale production. The nanoparticles showed strong effect on quantitative inhibition and disruption of antifungal growth.

In vitro and in vivo antifungal properties of silver nanoparticles against Rhizoctonia solani, a common agent of rice sheath blight disease

Sheath blight disease in rice has caused major crop losses worldwide. Managing the causal agent of disease Rhizoctonia solani Kühn is difficult because of its broad host range and formation of sclerotia which can survive in harsh environmental conditions; therefore developing innovative disease management methods without application of hazardous chemicals has been considered as the main concern to maintain sustainable agriculture. This presented research has revealed the negative impact of silver nanoparticles (SNPs) on R. solani and disease progress both in vitro and in vivo. The adverse effects of the SNPs on R. solaniare significantly dependent on the quantity of SNPs, sprayed at different concentrations in vitro. The highest inhibition level against sclerotia formation and mycelia growth are 92 and 85%, respectively, at a SNPs concentration of 50 ppm. In vivo glasshouse experiments also showed that SNPs at the same concentration favourably affects both the fresh and dry weight of rice plants with a remarkable suppressive effect on the lesion development in leaves.

Functionalized Graphene Oxide with Chitosan for Protein Nanocarriers to Protect against Enzymatic Cleavage and Retain Collagenase Activity

Proteins have short half-life because of enzymatic cleavage. Here, a new protein nanocarrier made of graphene oxide (GO) + Chitosan (CS) is proposed to successfully prevent proteolysis in protein and simultaneously retain its activity. Bovine serum albumin (BSA) and collagenase were loaded on GO and GO-CS to explore the stability and activity of proteins. SEM, AFM, TEM, DSC, UV-Vis, FT-IR, RBS, Raman, SDS-PAGE and zymography were utilized as characterization techniques. The protecting role of GO and GO-CS against enzymatic cleavage was probed by protease digestion analysis on BSA, where the protease solution was introduced to GO-BSA and GO-CS-BSA at 37 °C for 0.5-1-3-6 hours. Characterizations showed the successful synthesis of few layers of GO and the coverage by CS. According to gelatin zymographic analysis, the loaded collagenase on GO and GO-CS lysed the gelatin and created non-staining bands which confirmed the activity of loaded collagenase. SDS-PAGE analysis revealed no significant change in the intact protein in the GO-BSA and GO-CS-BSA solution after 30-minute and 1-hour exposure to protease; however, free BSA was completely digested after 1 hour. After 6 hours, intact proteins were detected in GO-BSA and GO-CS-BSA solutions, while no intact protein was detected in the free BSA solution.

Shape-Dependent Defect Structures of Monolayer MoS2 Crystals Grown by Chemical Vapor Deposition

Monolayer MoS₂ crystals with tailored morphologies have been shown to exhibit shape-dependent properties and thus have potential applications in building nanodevices. However, a deep understanding of the relationship between the shape and defect structures in monolayer MoS₂ is yet elusive. Monolayer MoS₂ crystals in polygonal shapes, including triangle, tetragon, pentagon, and hexagon, are grown using the chemical vapor deposition technique. Compared with other shapes, the hexagon MoS₂ crystal contains more electron-donor defects that are mainly due to sulfur vacancies. In the triangular shapes, the defects are mainly distributed at the vertices of the shapes while they are located at the center of hexagonal shapes. On the basis of the Coulomb interaction of exciton and trion, quantitative calculations demonstrate a high electron density (∼10¹²/cm²) and high Fermi level (E_C - E_F = 15 meV) for hexagonal shape at room temperature, compared to triangular shapes (∼10¹¹/cm², E_C - E_F ≈ 30 meV). These findings verify that a much higher number of donor-like sulfur vacancies are formed in hexagonal MoS₂ shapes. This property allows more electrons or trions to localize in such sites through the physical/chemical adsorption of O₂/H₂O, which results in a strong enhancement of the light emission efficiency in the hexagonal crystal. The findings provide a better understanding of the formation of shape-dependent defect structures of monolayer MoS₂ crystals and are inspiring for applications in fabricating nanoelectronic and optoelectronic devices through defect engineering.

Structural characterization of recombinant human fibroblast growth factor receptor 2b kinase domain upon interaction with omega fatty acids

The mutated recombinant kinase domain of human fibroblast growth factor receptor 2b (hFGFR2b) is overexpressed and purified, and its structural changes upon the interaction with three unsaturated fatty acids (UFAs), oleic, linoleic and α-linolenic are studied. This interaction is investigated to find out about the folding and unfolding effect of unsaturated fatty acids on the kinase domain structure of hFGFR2b. Recombinant pLEICS-01 vectors, containing the mutated coding region of hFGFR2b, are expressed in the standard Escherichia coli BL21 (DE3) host cells and purified by Ni²⁺-NTA affinity chromatography. While polyacrylamide gel electrophoresis characterizes the functionality of recombinant protein, its structural changes are studied in the presence and absence of various concentrations of oleic, α-linolenic and linoleic acids using circular dichroism (CD) and fluorescence spectroscopy. Far ultraviolet CD results show that unsaturated fatty acids do not change the secondary structure of the recombinant kinase domain of hFGFR2b. However, chemical denaturation analysis confirms that all three UFAs destabilize the tertiary structure of recombinant protein. A decrease in the fluorescence intensity without any significant red or blue shift (336±1nm) reflects a variation in the tertiary structure of protein. The direct interaction of the studied UFAs with hFGFR2b reduces the conformational stability of their kinase domains. The structural changes in hFGFR2b in the presence of UFAs may be necessary for hFGFR2b to adjust the signal transduction and regulate the key cellular processes.

Improved survival with dose-escalated radiotherapy in stage III non-small-cell lung cancer: analysis of the National Cancer Database

BACKGROUND

Concurrent chemoradiation is the standard of care in non-operable stage III non-small-cell lung cancer (NSCLC). Data have suggested a benefit of dose escalation; however, results from the randomized dose-escalation trial RTOG 0617 revealed a lower survival rate with high-dose radiation. To evaluate the impact of dose escalation on overall survival (OS) in stage III NSCLC treated with chemoradiotherapy outside the controlled setting of a randomized trial, we carried out an observational, population-based investigation of the National Cancer Database (NCDB).

PATIENTS AND METHODS

A total of 33 566 patients with stage III NSCLC treated with chemoradiation from 2004 to 2012 and radiation doses between 59.4 and 85 Gy were included. The primary end point was OS, with median survival calculated via Kaplan-Meier. Univariate, multivariable and propensity-score matching analyses were carried out.

RESULTS

Patients were stratified by dose with median OS of: 18.8, 19.8 and 21.6 months for cohorts receiving 59.4-60, 61-69 and ≥70 Gy, respectively (P < 0.001). Granular dose analyses were carried out demonstrating increased OS with increasing radiation dose: median survival of 18.8, 21.1, 22.0 and 21.0 months for 59.4-60, 66, 70 and ≥71 Gy, respectively. While 66, 70 and ≥71 Gy resulted in increased OS in comparison with 59.4-60 Gy, no significant difference in OS was observed when comparing 66 with ≥71 Gy (P = 0.38).

CONCLUSIONS

Dose escalation above 60 Gy was associated with improved OS in this cohort of stage III NSCLC patients treated with chemoradiotherapy. A plateau of benefit was observed, with no additional improvement in OS with increased dose (≥71 Gy) compared with 66-70 Gy. With evidence suggesting worse OS and quality of life with increased dose, these data support investigation of the role of intermediate-dose radiation, and in the absence of randomized evidence, may be leveraged to justify utilization of intermediate-dose radiation.