Pump-Free Glass-Based Capillary Microfluidic Immuno-Assay Chip for Electrochemical Detection of Prostate-Specific Antigen

Immuno-assay is one of diagnostic methods that usually measures biomarkers associated with cancers. However, this method is complex and take a long time to analyze. To overcome these disadvantages, many immuno-sensing chips have been designed and developed. However, these devices still require an external pump or electrical source. In this study, our group fabricated a capillary microfluidic device using glass and adhesive polyethylene terephthalate (PET) film, which were designed by simply patterning and cutting to make the microfluidic capillary channels. Using capillary force alone, glass microfluidic chip can control the speed of fluid-flow and the flow sequence by adjusting the width of the channel and design. In addition, each flow can push out other flow without mixing. The glass-based capillary microfluidic chip (GCMC) can automatically perform immunoassay in regular order without external devices and it provide an electrochemical signal analysis in an average of 2 min. The concentration of the prostate-specific antigen (PSA), a biomarker of prostate cancer, was measured by cyclic voltammetry (CV). In conclusion, GCMC can detect between a range of 100 pg/ml to 1 μg/ml of PSA and provide high selectivity to PSA.

Proximal arm weakness is the most common presentation in young Korean soldiers diagnosed as having hereditary neuropathy with liability to pressure palsy (HNPP)

OBJECTIVES

Because patients with hereditary neuropathy with liability to pressure palsy (HNPP) are diagnosed mostly in their 20s, they are likely to experience their first major neurological symptoms during military training. We aimed to analyse the clinical characteristics and electrodiagnostic study findings of patients diagnosed with HNPP during their military service.

METHODS

We identified patients diagnosed as having HNPP in 2011-2014 and investigated their initial symptom presentation, the location and severity of their weakness, the causative event, the results of electrodiagnostic studies and the results of the genetic analysis of the PMP-22 gene.

RESULTS

Among the 36 patients included in the study, 19 (52.8%) patients had upper extremity paraesthesia with proximal arm weakness caused by brachial plexus lesion. Distal upper extremity symptoms were found in 12 (33.3%) patients, and leg paraesthesia was present only in five (13.9%) patients. Among the 19 patients who had proximal arm weakness, the most common cause of weakness was the performance of push-ups as a punishment (36.8%), and strenuous push-up exercise was the second cause of this symptom (21.1%).

CONCLUSIONS

Brachial plexus lesion leading to proximal arm weakness and paraesthesia was the most common presentation in soldiers with HNPP, and strenuous push-up activity was the major leading causative event in this condition.