In this task, you are given an abstract of article. Your task is to generate title for this article. Preferred titles are under thirty words.

[Q]: Two hundred patients who were taking daily symptomatic or immediate relief medications, often in excessive quantities, yet suffering from daily or near daily severe headaches were studied. One hundred and sixteen (58%) of them were also taking concomitant prophylactic medications and they were ineffective. Low tyramine, low caffeine dietary instructions and biofeedback training were given to all patients. The effect of continuing symptomatic medications, discontinuing symptomatic medications, and adding or changing prophylactic medications were studied in the various treatment groups. It is concluded that; 1.) Daily use of symptomatic or immediate relief medications result in chronic daily headache. 2.) Discontinuing daily symptomatic medications itself result in improvement of headache. 3.) Concomitant use of symptomatic medications nullifies the effect of prophylactic medications. 4.) Discontinuing daily symptomatic medications enhances the beneficial effect of prophylactic medications.
[A]: Drug induced refractory headache--clinical features and management.

[Q]: During meiosis, recombination between homologous chromosomes generates crossover (CR) and noncrossover (NCR) products. CRs establish connections between homologs, whereas intermediates leading to NCRs have been proposed to participate in homologous pairing. How these events are differentiated and regulated remains to be determined. We have developed a strategy to detect, quantify, and map NCRs in parallel to CRs, at the Psmb9 meiotic recombination hot spot, in male and female mouse germ lines. Our results report direct molecular evidence for distinct CR and NCR pathways of DNA double-strand break (DSB) repair in mouse meiosis based on three observations: both CRs and NCRs require Spo11, NCR products have shorter conversion tracts than CRs, and only CRs require the MutL homolog Mlh1. We show that both products are formed from middle to late pachytene of meiotic prophase and provide evidence for an Mlh1-independent CR pathway, where mismatch repair does not require Mlh1.
[A]: Crossover and noncrossover pathways in mouse meiosis.

[Q]: Extracellular vesicles (EVs) are cell-derived membrane vesicles, and represent an endogenous mechanism for intercellular communication. Since the discovery that EVs are capable of functionally transferring biological information, the potential use of EVs as drug delivery vehicles has gained considerable scientific interest. EVs may have multiple advantages over currently available drug delivery vehicles, such as their ability to overcome natural barriers, their intrinsic cell targeting properties, and stability in the circulation. However, therapeutic applications of EVs as drug delivery systems have been limited due to a lack of methods for scalable EV isolation and efficient drug loading. Furthermore, in order to achieve targeted drug delivery, their intrinsic cell targeting properties should be tuned through EV engineering. Here, we review and discuss recent progress and remaining challenges in the development of EVs as drug delivery vehicles.
[A]:
Extracellular vesicles for drug delivery.