On-chip magnetophoretic capture in a model of malaria-infected red blood cells

The search for new rapid diagnostic tests for malaria is a priority for developing an efficient strategy to fight this endemic disease, which affects more than 3 billion people worldwide. In this paper, we characterize systematically an easy-to-operate lab-on-chip, designed for the magnetophoretic capture of malaria-infected red blood cells. The method relies on the positive magnetic susceptibility of infected red blood cells with respect to blood plasma. A matrix of nickel posts fabricated in a silicon chip placed face down is aimed at attracting infected cells, while healthy cells sediment on a glass slide under the action of gravity. Using a model of infected red blood cells, i.e. erythrocytes with methaemoglobin, we obtained a capture efficiency of about 70% after 10 minutes in static conditions. By proper agitation, the capture efficiency reached 85% after just 5 minutes. Sample preparation requires only a 1:10 volume dilution of whole blood, previously treated with heparin, in a phosphate buffered solution. Nonspecific attraction of untreated red blood cells was not observed in the same time interval. This article is protected by copyright. All rights reserved.

Repetitive element hypermethylation in multiple sclerosis patients

Background

Multiple sclerosis (MS) is a complex disorder of the central nervous system whose cause is currently unknown. Evidence is increasing that DNA methylation alterations could be involved in inflammatory and neurodegenerative diseases and could contribute to MS pathogenesis. Repetitive elements Alu, LINE-1 and SAT-α, are widely known as estimators of global DNA methylation. We investigated Alu, LINE-1 and SAT-α methylation levels to evaluate their difference in a case–control setup and their role as a marker of disability.

Results

We obtained blood samples from 51 MS patients and 137 healthy volunteers matched by gender, age and smoking. Methylation was assessed using bisulfite-PCR-pyrosequencing. For all participants, medical history, physical and neurological examinations and screening laboratory tests were collected. All repetitive elements were hypermethylated in MS patients compared to healthy controls. A lower Expanded Disability Status Scale (EDSS) score was associated with a lower levels of LINE-1 methylation for ‘EDSS = 1.0’ and ‘1.5 ≤ EDSS ≤ 2.5’ compared to an EDSS higher than 3, while Alu was associated with a higher level of methylation in these groups: ‘EDSS = 1.0’ and ‘1.5 ≤ EDSS ≤ 2.5’.

Conclusions

MS patients exhibit an hypermethylation in repetitive elements compared to healthy controls. Alu and LINE-1 were associated with degree of EDSS score. Forthcoming studies focusing on epigenetics and the multifactorial pathogenetic mechanism of MS could elucidate these links further.

Electronic supplementary material

The online version of this article (doi:10.1186/s12863-016-0395-0) contains supplementary material, which is available to authorized users.

MDC/CCL22 intrathecal levels in patients with multiple sclerosis

MDC/CCL22 has been detected in the brain of mice with experimental autoimmune encephalomyelitis. MDC/CCL22 cerebrospinal fluid levels were evaluated in 56 patients with multiple sclerosis (MS) and in 17 controls. No significant differences were found, even when stratifying patients according to the disease subtype. Stratifying by gender, significantly increased MDC/CCL22 levels were observed in female patients when compared with female controls and male patients (109.03 versus 98.54 and 99.37 pg/mL, P = 0.034 and 0.018, respectively). Therefore, MDC/CCL22 is likely to play a role in the development of MS in females only, possibly influencing the intracerebral recruitment of Th2 cells, which produce anti-inflammatory cytokines. Multiple Sclerosis 2008; 14: 547—549. http://msj.sagepub.com