Discovery of 4-(isopentyloxy)-3-nitrobenzamide derivatives as xanthine oxidase inhibitors through a non-anthraquinone exploration.

In our previous study, we reported a series of N-(9,10-anthraquinone-2-carbonyl) amino acid derivatives as novel inhibitors of xanthine oxidase (XO). Recognizing the suboptimal drug-like properties associated with the anthraquinone moiety, we embarked on a nonanthraquinone medicinal chemistry exploration in the current investigation. Through systematic structure-activity relationship (SAR) studies, we identified a series of 4-(isopentyloxy)-3-nitrobenzamide derivatives exhibiting excellent in vitro potency against XO. The optimized compound, 4-isopentyloxy-N-(1H-pyrazol-3-yl)-3-nitrobenzamide (6k), demonstrated exceptional in vitro potency with an IC50 value of 0.13 µM. Compound 6k showed favorable drug-like characteristics with ligand efficiency (LE) and lipophilic ligand efficiency (LLE) values of 0.41 and 3.73, respectively. In comparison to the initial compound 1d, 6k exhibited a substantial 24-fold improvement in IC50, along with a 1.6-fold enhancement in LE and a 3.7-fold increase in LLE. Molecular modeling studies provided insights into the strong interactions of 6k with critical amino acid residues within the active site. Furthermore, in vivo hypouricemic investigations convincingly demonstrated that 6k significantly reduced serum uric acid levels in rats. The MTT results revealed that compound 6k is nontoxic to healthy cells. The gastric and intestinal stability assay demonstrated that compound 6k exhibits good stability in the gastric and intestinal environments. In conclusion, compound 6k emerges as a promising lead compound, showcasing both exceptional in vitro potency and favorable drug-like characteristics, thereby warranting further exploration.

Salvianolic acid B ameliorates retinal deficits in an early-stage Alzheimer's disease mouse model through downregulating BACE1 and Aß generation.

Alzheimer's disease (AD) is a neurodegenerative disease with subtle onset, early diagnosis remains challenging. Accumulating evidence suggests that the emergence of retinal damage in AD precedes cognitive impairment, and may serve as a critical indicator for early diagnosis and disease progression. Salvianolic acid B (Sal B), a bioactive compound isolated from the traditional Chinese medicinal herb Salvia miltiorrhiza, has been shown promise in treating neurodegenerative diseases, such as AD and Parkinson's disease. In this study we investigated the therapeutic effects of Sal B on retinopathy in early-stage AD. One-month-old transgenic mice carrying five familial AD mutations (5×FAD) were treated with Sal B (20 mg·kg-1·d-1, i.g.) for 3 months. At the end of treatment, retinal function and structure were assessed, cognitive function was evaluated in Morris water maze test. We showed that 4-month-old 5×FAD mice displayed distinct structural and functional deficits in the retinas, which were significantly ameliorated by Sal B treatment. In contrast, untreated, 4-month-old 5×FAD mice did not exhibit cognitive impairment compared to wild-type mice. In SH-SY5Y-APP751 cells, we demonstrated that Sal B (10 µM) significantly decreased BACE1 expression and sorting into the Golgi apparatus, thereby reducing Aß generation by inhibiting the ß-cleavage of APP. Moreover, we found that Sal B effectively attenuated microglial activation and the associated inflammatory cytokine release induced by Aß plaque deposition in the retinas of 5×FAD mice. Taken together, our results demonstrate that functional impairments in the retina occur before cognitive decline, suggesting that the retina is a valuable reference for early diagnosis of AD. Sal B ameliorates retinal deficits by regulating APP processing and Aß generation in early AD, which is a potential therapeutic intervention for early AD treatment.

Association between hydroxyethyl starch 130/0.4 administration during noncardiac surgery and postoperative acute kidney injury: A propensity score-matched analysis of a large cohort in China.

STUDY OBJECTIVE: The use of hydroxyethyl starch 130/0.4 has been linked to renal injury in critically ill patients, but its impact on surgical patients remains uncertain. DESIGN: A retrospective cohort study. SETTING: This study was conducted at one tertiary care hospital in China. PATIENTS: We evaluated the records of 51,926 Chinese adults who underwent noncardiac surgery from 2013 to 2022. Patients given a combination of hydroxyethyl starch 130/0.4 and crystalloids were propensity-matched at a 1: 1 ratio of baseline characteristics to patients given only crystalloids (11,725 pairs). INTERVENTIONS: Eligible patients were divided into those given a combination of hydroxyethyl starch 130/0.4 and crystalloid during surgery and a reference crystalloid group consisting of patients who were not given any colloid. MEASUREMENTS: The primary outcome was the incidence of acute kidney injury. Secondarily, acute kidney injury stage, need for renal replacement therapy, intensive care unit transfer rate, and duration of postoperative hospitalization were considered. MAIN RESULTS: After matching, hydroxyethyl starch use [8.5 (IQR: 7.5-10.0) mL/kg] did not increase the incidence of acute kidney injury compared with that in the crystalloid group [2.0 vs. 2.2%, OR: 0.90 (0.74-1.08), P = 0.25]. Nor did hydroxyethyl starch use worsen acute kidney injury stage [OR 0.90 (0.75-1.08), P = 0.26]. No significant differences between the fluid groups were observed in renal replacement therapy [OR 0.60 (0.41-0.90), P = 0.02)] or intensive care unit transfers [OR 1.02 (0.95-1.09), P = 0.53] after Bonferroni correction. Even in a subset of patients at high risk of renal injury, hydroxyethyl starch use was not associated with worse outcomes. CONCLUSIONS: Hydroxyethyl starch 130/0.4 use was not significantly associated with a greater incidence of postoperative acute kidney injury compared to receiving crystalloid solutions only.

Amelioration of olfactory dysfunction in a mouse model of Parkinson's disease via enhancing GABAergic signaling.

BACKGROUND: Olfactory dysfunction is among the earliest non-motor symptoms of Parkinson's disease (PD). As the foremost pathological hallmark, α-synuclein initiates the pathology in the olfactory pathway at the early stage of PD, particularly in the olfactory epithelium (OE) and olfactory bulb (OB). However, the local neural microcircuit mechanisms underlying olfactory dysfunction between OE and OB in early PD remain unknown. RESULTS: We observed that odor detection and discrimination were impaired in 6-month-old SNCA-A53T mice, while their motor ability remained unaffected. It was confirmed that α-synuclein increased and accumulated in OB but not in OE. Notably, the hyperactivity of mitral/tufted cells and the excitation/inhibition imbalance in OB were found in 6-month-old SNCA-A53T mice, which was attributed to the impaired GABAergic transmission and aberrant expression of GABA transporter 1 and vesicular GABA transporter in OB. We further showed that tiagabine, a potent and selective GABA reuptake inhibitor, could reverse the impaired olfactory function and GABAergic signaling in OB of SNCA-A53T mice. CONCLUSIONS: Taken together, our findings demonstrate potential synaptic mechanisms of local neural microcircuit underlying olfactory dysfunction at the early stage of PD. These results highlight the critical role of aberrant GABAergic signaling of OB in early diagnosis and provide a potential therapeutic strategy for early-stage PD.

Characterization of sintered titanium/hydroxyapatite biocomposite using FTIR spectroscopy.

Fourier transform infrared (FTIR) spectroscopy was employed to characterize the phase changes of hydroxyapatite (Ca(10)(PO(4))(6)(OH)(2), HA) in a titanium/HA biocomposite during sintering. The effects of sintering temperature and the presence of Ti on the decomposition of HA were examined. It was observed that pure HA was stable in argon atmosphere at temperatures up to 1,200 degrees C, although the dehydroxylation of pure HA was promoted by the increase in sintering temperature. In the Ti/HA system, on the other hand, the presence of Ti accelerated dehydroxylation and the decomposition of HA was detected at a temperature as low as 800 degrees C. Tetracalcium phosphate (Ca(4)P(2)O(9), TTCP) and calcium oxide (CaO) were the dominant products of the decomposition, but no tricalcium phosphate (Ca(3)(PO(4))(2), TCP) was detected due to phosphorus diffusion and possible reactions during the thermal process. The main decomposed constituents of HA in Ti/HA system at high temperatures (> or =1,200 degrees C) would be CaO and amorphous phases.