Flow cytometric evaluation of the contribution of ionic silver to genotoxic potential of nanosilver in human liver HepG2 and colon Caco2 cells

Exposure to nanosilver found in food‐ and cosmetics‐related consumer products is of public concern because of the lack of information about its safety. In this study, two widely used in vitro cell culture models, human liver HepG2 and colon Caco2 cells, and the flow cytometric micronucleus (FCMN) assay were evaluated as tools for rapid predictive screening of the potential genotoxicity of nanosilver. Recently, we reported the genotoxicity of 20 nm nanosilver using these systems. In the current study presented here, we tested the hypothesis that the nanoparticle size and cell types were critical determinants of its genotoxicity. To test this hypothesis, we used the FCMN assay to evaluate the genotoxic potential of 50 nm nanosilver of the same shape, composition, surface charge and obtained from the same commercial source using the same experimental conditions and in vitro models (HepG2 and Caco2) as previously tested for the 20 nm silver. Results of our study show that up to the concentrations tested in these cultured cell test systems, the smaller (20 nm) nanoparticle is genotoxic to both the cell types by inducing micronucleus (MN). However, the larger (50 nm) nanosilver induces MN only in HepG2 cells, but not in Caco2 cells. Also in this study, we evaluated the contribution of ionic silver to the genotoxic potential of nanosilver using silver acetate as the representative ionic silver. The MN frequencies in HepG2 and Caco2 cells exposed to the ionic silver in the concentration range tested are not statistically significant from the control values except at the top concentrations for both the cell types. Therefore, our results indicate that the ionic silver may not contribute to the MN‐forming ability of nanosilver in HepG2 and Caco2 cells. Also our results suggest that the HepG2 and Caco2 cell cultures and the FCMN assay are useful tools for rapid predictive screening of a genotoxic potential of food‐ and cosmetics‐related chemicals including nanosilver. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.     

A Study of Erosion–Corrosion Behaviour of Friction Stir-Processed Chromium-Reinforced NiAl Bronze Composite

Corrosion is frequently viewed as a catastrophic and unavoidable disaster in marine applications. Every year, a huge cost is incurred on the maintenance and repair of corrosion-affected equipment and machinery. In the marine environment, as-cast nickel–aluminium bronze (NAB) is susceptible to selective phase corrosion. To solve this problem, chromium-reinforced nickel–aluminium bronze was fabricated using the friction stir process (FSP) with improved microstructures and surface properties. A slurry erosion–corrosion test on as-cast and FSPed composites demonstrated that the developed surfaced composite has lower erosion and corrosion rates than the as-cast NAB alloy. The erosion–corrosion rate increased with a decrease in the impact angle from 90° to 30° for both as-cast NAB and prepared composites, exhibiting a shear mode of erosion. The specimens at impact angle 30° experienced more pitting action and higher mass loss compared with those at impact angle 90°. Due to increases in the mechanical properties, the FS-processed composite showed higher erosion resistance than the as-cast NAB alloy. Furthermore, corrosion behaviour was also studied via the static immersion corrosion test and electrochemical measurements under 3.5 wt.% NaCl solution. In a static immersion corrosion test, the FSPed composite outperformed the as-cast NAB composite by a wide margin. The FSPed composite also demonstrated a reduced electrochemical corrosion rate, as revealed by the polarization curve and electrochemical impedance spectroscopic (EIS) data. This reduced rate is attributed to the formation of a Cr oxide film over its surface in the corrosive environment.     

Response to controlled ovarian stimulation and oocyte quality in women with myotonic dystrophy type I

Purpose In women the relationship between myotonic dystrophy type I and fertility remains controversial. The objective of this study was to evaluate the ovarian reserve, ovarian response to stimulation and oocyte quality in these patients. Materials and methods We compared 15 myotonic dystrophy type I patients with 39 age matched controls with isolated male factor infertility necessitating ICSI. Results All parameters of ovarian reserve (day 3 FSH and E2, antral follicle count and delta E2) were significantly better in the controls. Despite having significantly lower doses of gonadotrophin, the control group attained a higher number of retrieved oocyte–cumulus complexes (p < 0.04). Analysis of cytoplasmic and extracytoplasmic dysmorphism did not reveal any difference between the two groups. Fertilisation rate and top grade embryos on day 3 were similar in both groups. Conclusion The present study suggests that though women with myotonic dystrophy type I have a reduced ovarian reserve and respond poorly to controlled ovarian stimulation, there is no impact on oocyte and embryo quality. Hence suggesting that successful ART is feasible with appropriate selection in women with mild myotonic dystrophy. Capsule Women with myotonic dystrophy type I have reduced ovarian reserve and respond poorly to controlled ovarian stimulation, though there is no impact on oocyte quality.     

Evaluation of pregnant women with scarred uterus in a low resource setting

AIM: Management of post cesarean pregnancy continues to be a dilemma. The present study was undertaken to evaluate the outcome of such pregnancies in a resource constrained setting so that an appropriate management protocol can be decided. METHODS: An observational study was conducted in the Department Of Obstetrics And Gynecology, King George's Medical University, Lucknow, India. The outcome of all of the women admitted with pregnancy with a previous cesarean section was noted. RESULTS: A total number of 447 women with a post cesarean pregnancy underwent delivery. These comprised 13.7% of total deliveries over the same period. 124 women (27.7%) had successful vaginal delivery while 323 (72.3%) had a repeat cesarean section. Maternal morbidity and perinatal mortality were both significantly higher in the vaginal delivery group (P = 0.00211 and P = 0.0426, respectively). CONCLUSIONS: Vaginal birth after cesarean (VBAC) is associated with higher maternal morbidity and perinatal mortality. Therefore the decision for VBAC must be taken only after proper consideration and counseling of the couple.     

A molecularly integrated grade for meningioma

BackgroundMeningiomas are the most common primary intracranial tumor in adults. Clinical care is currently guided by the World Health Organization (WHO) grade assigned to meningiomas, a 3-tiered grading system based on histopathology features, as well as extent of surgical resection. Clinical behavior, however, often fails to conform to the WHO grade. Additional prognostic information is needed to optimize patient management.MethodsWe evaluated whether chromosomal copy-number data improved prediction of time-to-recurrence for patients with meningioma who were treated with surgery, relative to the WHO schema. The models were developed using Cox proportional hazards, random survival forest, and gradient boosting in a discovery cohort of 527 meningioma patients and validated in 2 independent cohorts of 172 meningioma patients characterized by orthogonal genomic platforms.ResultsWe developed a 3-tiered grading scheme (Integrated Grades 1-3), which incorporated mitotic count and loss of chromosome 1p, 3p, 4, 6, 10, 14q, 18, 19, or CDKN2A. 32% of meningiomas reclassified to either a lower-risk or higher-risk Integrated Grade compared to their assigned WHO grade. The Integrated Grade more accurately identified meningioma patients at risk for recurrence, relative to the WHO grade, as determined by time-dependent area under the curve, average precision, and the Brier score.ConclusionWe propose a molecularly integrated grading scheme for meningiomas that significantly improves upon the current WHO grading system in prediction of progression-free survival. This framework can be broadly adopted by clinicians with relative ease using widely available genomic technologies and presents an advance in the care of meningioma patients.     

Association of TNF level with production of circulating cellular microparticles during clinical manifestation of human cerebral malaria

Microparticles (MPs) resulting from vesiculation of different cell types in Plasmodium falciparum infection correlate with the level of proinflammatory cytokine TNF that may thereby determine the disease severity. Using TruCount tube based flow cytometric method for the exact quantification of MP and enzyme linked immunosorbent assay for the measurement of TNF, we conducted a hospital based case control study on P. falciparum malaria patients to scrutinize and infer the link between the two. In 52 cerebral malaria (CM), 21 multi-organ-dysfunction (MOD), 12 non cerebral severe malaria (NCSM) and 43 uncomplicated malaria patients, the MP level was found to be significantly elevated in febrile malaria patients compared to healthy controls and a striking decrease in MP level was observed with the clearance of the P. falciparum infection in the patients upon follow-up. The lowering of the parasite density with the level of plasma TNF and the positive correlation of the cytokine with the cell derived MPs and negative correlation with the respective cell count in human malaria patients suggests that TNF may be a key stimulant to the cells resulting in the release of MPs in malaria infection.