Imidazo[1,2-a]pyridine is one of the most potential bicyclic 5-6 heterocyclic rings that is recognized as a "drug prejudice" scaffold due to its broad range of applications in medicinal chemistry such as anticancer, antimycobacterial, antileishmanial, anticonvulsant, antimicrobial, antiviral, antidiabetic, proton pump inhibitor, insecticidal activities. This scaffold has also been represented in various marketed preparations such as zolimidine, zolpidem, alpidem. Therefore, several attempts were made to carry out the structural modifications of this scaffold to discover and develop novel therapeutic agents. This review provides a valuable insight into the research findings of wide range of derivatives of imidazo[1,2-a]pyridine scaffold leading to promising heterocyclic compounds which could be explored further for the synthesis of new derivatives as well as construction of potential drug-like chemical libraries for biological screening in search of new therapeutic agents.

SUMMARYEstrogens are essential for normal brain functions. The effects of estrogens on seizures are contradictory. More studies are necessary to determine under which conditions the estrogens have proconvulsant effects and when the estrogens may have beneficial action in patients with epilepsy. KEY WORDS: Catamenial epilepsy, Estrogen, Female rat, Hippocampus, Neuronal excitability, Neuroprotection.Catamenial epilepsy is a condition during which seizures tend to cluster in relevance to menstrual cycle in some women with epilepsy [for detailed recent review see (Reddy, 2009)]. Herzog et al. (1997) recognized three patterns of catamenial epilepsy based on the higher seizure occurrence during the individual phases of the menstrual cycle: perimenstrual, periovulatory, and inadequate luteal phase patterns. The changes in seizure occurrence in distinct phases of the catamenial epilepsy have been notoriously simplified to the changes in the female sex hormone levels, with estrogens increasing and progesterone suppressing neuronal excitability. Interestingly, most women with catamenial epilepsy report worsening of seizures during the perimenstrual phase. This phase is characterized by rapid decline in the levels of both hormones (estrogen and progesterone), as this is the signal for the initiation of menstruation. Low levels of estrogen and progesterone are the hallmark of this phase. Moreover, linking the catamenial epilepsy solely to estrogens and progesterone is an oversimplification, since the underlying mechanisms for the increased neuronal excitability during the distinct phases of the menstrual cycle are clearly multifactorial (Reddy, 2009). On the other hand, despite the argument of whether the sex hormone contribution is a direct effect of sex hormones on neuronal receptor systems or an indirect effect as a result of hormone-induced changes in gene expression, the involvement of estrogens and progesterone in regulation of neuronal excitability is undisputable. We have been interested in determining the effects of estrogens on seizures and neuronal excitability, which represents the main focus of this article.

Objectives ANCA-associated vasculitis (AAV) can affect all age groups. We aimed to show that differences in disease presentation and 6 month outcome between younger- and older-onset patients are still incompletely understood. Methods We included patients enrolled in the Diagnostic and Classification Criteria for Primary Systemic Vasculitis (DCVAS) study between October 2010 and January 2017 with a diagnosis of AAV. We divided the population according to age at diagnosis: <65 years or ≥65 years. We adjusted associations for the type of AAV and the type of ANCA (anti-MPO, anti-PR3 or negative). Results A total of 1338 patients with AAV were included: 66% had disease onset at <65 years of age [female 50%; mean age 48.4 years (s.d. 12.6)] and 34% had disease onset at ≥65 years [female 54%; mean age 73.6 years (s.d. 6)]. ANCA (MPO) positivity was more frequent in the older group (48% vs 27%; P = 0.001). Younger patients had higher rates of musculoskeletal, cutaneous and ENT manifestations compared with older patients. Systemic, neurologic,cardiovascular involvement and worsening renal function were more frequent in the older-onset group. Damage accrual, measured with the Vasculitis Damage Index (VDI), was significantly higher in older patients, 12% of whom had a 6 month VDI ≥5, compared with 7% of younger patients (P = 0.01). Older age was an independent risk factor for early death within 6 months from diagnosis [hazard ratio 2.06 (95% CI 1.07, 3.97); P = 0.03]. Conclusion Within 6 months of diagnosis of AAV, patients >65 years of age display a different pattern of organ involvement and an increased risk of significant damage and mortality compared with younger patients.

Therapeutic applications of light emitting diode‐red light (LED‐RL) are expanding, yet data on its clinical effects are lacking. Our goal was to evaluate the safety of high fluence LED‐RL (≥160 J/cm2). In two phase I, single‐blind, dose escalation, randomized controlled trials, healthy subjects received LED‐RL or mock irradiation to the forearm thrice weekly for 3 weeks at fluences of 160‐640 J/cm2 for all skin types (STARS 1, n = 60) and at 480‐640 J/cm2 for non‐Hispanic Caucasians (STARS 2, n = 55). The primary outcome was the incidence of adverse events (AEs). The maximum tolerated dose was the highest fluence that did not elicit predefined AEs. Dose‐limiting AEs, including blistering and prolonged erythema, occurred at 480 J/cm2 in STARS 1 (n = 1) and 640 J/cm2 in STARS 2 (n = 2). AEs of transient erythema and hyperpigmentation were mild. No serious AEs occurred. We determined that LED‐RL is safe up to 320 J/cm2 for skin of color and 480 J/cm2 for non‐Hispanic Caucasian individuals. LED‐RL may exert differential cutaneous effects depending on race and ethnicity, with darker skin being more photosensitive. These findings may guide future studies to evaluate the efficacy of LED‐RL for the treatment of various diseases.