Virus removal from semen with a pinched flow fractionation microfluidic chip.

Nowadays pigs are bred with artificial insemination to reduce costs and transportation. To prevent the spread of diseases, it is important to test semen samples for viruses. Screening techniques applied are enzyme-linked immunosorbent assays and/or polymerase chain reaction, which are labor-intensive and expensive methods. In contrast to the current used screening techniques, it is possible to remove viruses physically from semen. However, existing methods for virus removal techniques have a low yield of spermatozoa. Therefore, we have developed a microfluidic chip that performs size-based separation of viruses and spermatozoa in boar semen samples, thereby having the potential to reduce the risk of disease spreading in the context of artificial insemination in the veterinary industry. As the head of a spermatozoon is at least twenty times larger than a virus particle, the particle size can be used to achieve separation, resulting in a semen sample with lower viral load and of higher quality. To achieve the size separation, our microfluidic device is based on pinched-flow fractionation. A model virus, cowpea chlorotic mottle virus, was used and spiked to porcine semen samples. With the proposed microfluidic chip and the optimized flow parameters, at least 84 ± 4% of the model viruses were removed from the semen. The remaining virus contamination is caused by the model virus adhering to spermatozoa instead of the separation technique. The spermatozoa recovery was 86 ± 6%, which is an enormous improvement in yield compared to existing virus removal techniques.

Short term efficacy and safety in glaucoma patients changed to the latanoprost 0.005%/timolol maleate 0.5% fixed combination from monotherapies and adjunctive therapies.

AIMS: To evaluate efficacy and safety in patients with ocular hypertension or open angle glaucoma changed to latanoprost/timolol fixed combination (LTFC). METHODS: A prospective, multicentre, historical control in which qualified patients had their previous therapy substituted by LTFC and were followed for at least 2 months. RESULTS: In 1676 patients LTFC was continued in 93% throughout the observation period. In all patients LTFC reduced the intraocular pressure (IOP) from 20.6 (SD 3.8) to 17.7 (3.0) mm Hg (p<0.001) compared to previous monotherapies including latanoprost, timolol, alpha agonists or carbonic anhydrase inhibitors (CAI). LTFC provided more efficacy after changing from adjunctive therapies including: a beta blocker added to either CAI, alpha agonist, or pilocarpine, or CAI added to an alpha agonist, or latanoprost added to either CAI, alpha agonist, or beta blocker (unfixed combination), and travoprost added to timolol (p<0.007). LTFC was as effective as latanoprost used with dorzolamide/timolol fixed combination (-0.9 mm Hg, p = 0.1792). The most common reason to discontinue therapy was lack of efficacy (n = 70, 4%) and adverse event (n = 17, 1%). CONCLUSION: In a clinical setting, patients who have their monotherapy or adjunctive therapy substituted with LTFC may experience reduced IOP, good tolerability, and continuation of therapy for the first 2-3 months of treatment.