Upper gastrointestinal lesions in patients receiving clopidogrel anti-platelet therapy.

BACKGROUND/PURPOSE: Clopidogrel is associated with a high incidence of upper gastrointestinal bleeding in high-risk patients. However, the characteristic upper gastrointestinal lesions in symptomatic clopidogrel users remain unclear. The aims of this study were to investigate the characteristics of endoscopic findings in clopidogrel users undergoing endoscopy for upper gastrointestinal symptoms and to compare the clinical characteristics and upper gastrointestinal lesions between symptomatic clopidogrel and aspirin users. METHODS: This observational study included 215 consecutive patients receiving clopidogrel (n=106) or low-dose aspirin (n=109) therapy who underwent endoscopy for dyspeptic symptoms. The upper gastrointestinal lesions were carefully assessed, and a complete medical history was obtained by a standard questionnaire. RESULTS: The frequencies of hemorrhagic spots, erosions and peptic ulcers in the symptomatic clopidogrel users were 25%, 39% and 39%, respectively. Among the peptic ulcer patients on clopidogrel therapy, the distributions of ulcers were 78%, 5% and 17% in the stomach, duodenum and both, respectively. Compared with the aspirin group, the clopidogrel group was older and had higher frequencies of past ulcer history and past gastrointestinal bleeding history in their clinical characteristics. By contrast, the clopidogrel users had a lower prevalence of active Helicobacter pylori infection than aspirin users (17% vs. 35%, respectively, p=0.007). Regarding to the endoscopic findings, the clopidogrel users had higher frequencies of hemorrhagic spots (25% vs. 10%) and peptic ulcer (39% vs. 24%) than aspirin users (p=0.004 and 0.027, respectively). CONCLUSION: Most peptic ulcers in clopidogrel users are located in the stomach. The frequencies of hemorrhagic spots and peptic ulcers in symptomatic clopidogrel users are higher than those in symptomatic aspirin users.

Isolation of motile spermatozoa with a microfluidic chip having a surface-modified microchannel.

Conventional methods to prepare sperm have been amenable to the investigation of outcomes such as rates of recovery and conventional semen parameters. The standard preparation of sperm for assisted reproduction is criticized for its centrifugation steps, which might either recover motile sperm in variable proportions or increase the probability of damage to sperm DNA. An microfluidic system was designed to separate motile sperm according to a design whereby nonmotile spermatozoa and debris flow along their initial streamlines and exit through one outlet-up, whereas motile spermatozoa have an opportunity to swim into a parallel stream and to exit through a separate outlet-down. This chip was fabricated by microelectromechanical systems technology with polydimethylsiloxane molding. The hydrophilic surface, coated with poly (ethanediol) methyl ether methacrylate, exhibits enduring stability maintained for the microchannel. Microscopic examination and fluorescent images showed that the motility of sperm varied with the laminar streams. To confirm the sorting, we identified and quantified the proportions of live and dead sperm before and after sorting with flow cytometric analysis. The results on the viability of a sample demonstrated the increased quality of sperm after sorting and collection in the outlet reservoir. The counted ratio of live sperm revealed the quantity and efficiency of the sorted sperm.