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Abstract Human serum amyloid A (SAA) is an apolipoprotein that predominantly associates with high-density lipoprotein (HDL) in the blood and participates in lipid metabolism. In addition, SAA serves as a precursor of amyloid fibrils that contribute to the development of AA amyloidosis. Chemical modifications of amyloidogenic proteins can influence the formation of amyloid fibrils. Recently, various modified SAA molecular species have been discovered in patients with AA amyloidosis. In the present study, we examined how carbamoylation and oxidation affect the structural stability, lipid binding, and amyloid fibril formation of SAA. Thermal denaturation experiments showed that these modifications reduced the thermal stability of the SAA molecule at low temperatures, although SAA itself is unstructured at physiological temperature. Upon binding to phospholipid vesicles, α-helical structure was induced. Carbamoylation exerted minimal effects on the lipid binding, whereas oxidation markedly reduced it. Chemical modifications affected not only the kinetics of amyloid fibril formation but also their fibril morphologies. Overall, these findings suggest that chemical modifications of SAA can alter its structural stability, lipid-binding ability, and amyloidogenic properties, thereby potentially contributing to the onset of AA amyloidosis.
Intranasal powder formulations offer advantages in terms of stability and portability; however, their absorption is critically dependent on dissolution within the limited fluid volume of the nasal cavity. Conventional dissolution tests, originally developed for oral medicines, fail to adequately capture dissolution dynamics under nasal conditions, making the prediction of bioavailability after intranasal powder administration (BAp) particularly challenging. A Raman spectroscopy-based approach was established to directly monitor the time-dependent dissolution of drug particles in Calu-3 cell layers. Dissolution rate constants derived from particle size reduction were integrated with the nasal mean residence time (MRT) and bioavailability after intranasal solution administration (BAs) to define a predictive metric, the dissolution-MRT-BAs (DTB) parameter. Model drugs exhibited distinct dissolution profiles: rapid (antipyrine and atenolol), intermediate (acyclovir and levofloxacin), and limited (norfloxacin and griseofulvin). The DTB parameter was strongly correlated with BAp (R = 0.983, p < 0.001), and the enhancement of norfloxacin dissolution by lactose was also captured by this metric. The DTB parameter, which integrates dissolution kinetics, nasal residence time, and bioavailability, serves as a rational tool for predicting the absorption behavior of nasal powder formulations. This study highlights the potential of Raman spectroscopy as a quantitative method to support formulation design and establish in vitro-in vivo correlations in nasal drug delivery.
STUDY OBJECTIVES:To investigate the prescription patterns for hypnotics among patients <18 years in Japan. METHODS:We conducted a descriptive epidemiologic study using a claims database in Japan. We included patients aged 0-17 years with first-time prescriptions for hypnotics between June 2021 and June 2023. Hypnotics were classified as melatonin, melatonin receptor agonists (MRAs), dual orexin receptor antagonists (DORAs), Z-drugs, and benzodiazepines. We described the types of hypnotics, dosages, prescription duration, comorbidities, and concomitant medications for overall and by age groups. RESULTS:The study included 21 145 patients; 1983 aged 0-6 years, 3901 aged 7-11 years, 6664 aged 12-14 years, and 8597 aged 15-17 years. The initial prescribed hypnotics were melatonin (33.9%), MRAs (30.9%), DORAs (18.8%), Z-drugs (10.1%), and benzodiazepines (6.3%). Melatonin was more likely to be prescribed to patients age 0-11 years, MRAs to those aged 0-17 years, and DORAs to patients ages 15-17 years. The most common mental health-related comorbidities were autism spectrum disorder (32.5%), depression (23.4%), attention-deficit hyperactivity disorder (19.8%), and anxiety disorder (18.2%). CONCLUSIONS:Melatonin was most frequently prescribed in children for a longer duration than other hypnotics, while MRAs were prescribed across all age groups and DORAs mainly to adolescents. These age-specific patterns suggest that the drug selection was conducted according to patient's age, since pediatric insomnia might be correlated with psychiatric disorders related to developmental stage. Future research should investigate the long-term effects of hypnotic prescriptions with consideration of comorbid conditions.
In vaccine therapy, there is a growing interest in novel immunostimulatory adjuvants derived from food products or dietary supplements with safe profiles. Pavlova is a microalga commonly used as a dietary supplement. Owing to its immune-activating potency and safety profiles, Pavlova offers novel possibilities as an immunostimulatory adjuvant. However, precise control of their proliferation profile and subsequent immune activation when administered to the host is difficult, limiting their practicality as adjuvants. Extracellular vesicles (EVs) are cell-derived nanoparticles containing nucleic acids and proteins. EVs exhibit biological activity without proliferating, indicating their potential in medical applications as novel cell-free materials. However, information on EVs secreted by microalgae, including Pavlova, is limited. In this study, we characterized the EVs from Pavlova as an immunostimulatory adjuvant. Heated Pavlova-derived EVs (hP-EVs) and non-heated Pavlova-derived EVs (n-hP-EVs) were purified from their culture supernatants, with heated Pavlova secreting larger amounts of EVs. These EVs exhibited a particle size of approximately 130-170 nm and a negatively-charged zeta potential. RAW264.7 macrophage cells more actively took up n-hP-EVs than hP-EVs via endocytosis. As an adjuvant activity, n-hP-EVs potently increased the production of the inflammatory cytokines tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), which are indicators of enhanced innate immune response. Moreover, the effect of the storage temperature on the particle size of n-hP-EVs was small, maintaining their ability to activate innate immune responses. Thus, n-hP-EVs demonstrate attractive characteristics for use as novel cell-derived immunostimulatory adjuvants.
