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  • Duncan McGrath posted an update 4 months, 3 weeks ago

    This study investigated the distribution of quetiapine and 7-hydroxyquetiapine in guinea pig hair roots and shafts after five repeated intragastric administrations at three doses (5, 10 and 25 mg/kg) by segmental analysis to explore the mechanism of drug entry and retention in hair. Hair root samples were collected after 7, 10, 14, 21, 28 and 35 d in area A after the first dose, and a hair shaft was plucked 35 d after the first dose. The maximum concentrations of quetiapine in hair roots in the low-, medium- and high-dose groups occurred at 50, 74 and 98 h after the first administration, and the maximum concentrations were 0.71 ng/mg (range 0.54-0.84 ng/mg), 6.72 ng/mg (range 4.59-9.75 ng/mg) and 12.72 ng/mg (range 10.74-15.76 ng/mg), respectively. The maximum concentrations of 7-hydroxyquetiapine in the low-, medium- and high-dose groups were 0.67 ng/mg (0.23-1.15 ng/mg), 1.07 ng/mg (0.44-1.19 ng/mg) and 3.92 ng/mg (0.656.14 ng/mg), respectively, at 26 h. The maximum concentrations of quetiapine and 7-hydroxyquetiapine in hair roots were significantly positively correlated with the dose (n = 18; r2 = 0.84; P  less then  0.0001 for quetiapine and n = 18; r2 = 0.61; P = 0.0001 for 7-hydroxyquetiapine). The concentrations of quetiapine and 7-hydroxyquetiapine in hair roots were higher than those in hair shafts 10 d after administration, indicating drug and metabolite entry into the hair through the roots in the first few days after administration. The highest concentrations of quetiapine in the hair shaft in the low-, medium- and high-dose groups were found at the hair ends, and 7-hydroxyquetiapine in the hair shaft showed no obvious peak concentration. Combined with previous studies, we think, by analyzing the drug concentrations in the hair roots and shaft, that the most important way for drugs to enter into and be retained in hair is that the drug enters the hair through the blood circulation from hair root, then spreads and redistributes as the hair grows.Alternative antibiotics for surgical prophylaxis are associated with increased adverse events and surgical site infection compared to cefazolin. find more In a sample of perioperative inpatients from 100 US hospitals, cefazolin was 9-fold less likely to be used in patients with a documented beta-lactam allergy while clindamycin was 45-fold more likely.

    Porcine translational models have become the gold-standard translational tool to study the effects of major injury and hemorrhagic shock because of their similarity to the human immunologic response to trauma. Segmental bone defects (SBDs) typically occur in warfighters with associated severe limb trauma. The purpose of this study was to develop a translational porcine diaphyseal SBD model in Yucatan minipigs (YMPs), which could be used in bone healing investigations that simulate injury-relevant conditions. We were specifically working toward developing a critical sized defect (CSD).

    We used an adaptive experimental design in which both 25.0 mm and 40.0 mm SBDs were created in the tibial mid-diaphysis in skeletally mature YMPs. Initially, eight YMPs were subjected to a 25.0 mm SBD and treated with intramedullary nailing (intramedullary nail [IMN] 25mm). Due to unanticipated wound problems, we subsequently treated four specimens with identical 25.0 mm defect with dual plating (open reduction with internalst, a 25 mm SBD treated with dual plating demonstrated delayed but successful healing, indicating it can potentially be used to investigate bone healing adjuncts or conversely how concomitant injuries may impair bone healing. Pigs treated with IMN failed to heal and developed consistent delayed wound breakdown presumably secondary to chronic limb instability. The porcine YMP SBD model has the potential to be an effective translational tool to investigate bone healing under physiologically relevant injury conditions.Endoplasmic reticulum (ER) stress plays a critical role in pancreatic β cell destruction which leads to the pathogenesis of type 1 diabetes mellitus (T1DM). Vitamin D (VD) has been reported to reduce the risk of T1DM; however, it remains unknown whether VD affects ER stress in pancreatic β cells. In this study, we investigated the role of the active form of VD, 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3], in ER stress-induced β cell apoptosis and explored its potential mechanism in mouse insulinoma cell line mouse insulinoma 6 (MIN6). The results of cell counting kit-8 (CCK8) and flow cytometric analyses showed that 1,25-(OH)2D3 caused a significant increase in the viability of MIN6 cells injured by H2O2. The protein kinase like ER kinase (PERK) signal pathway, one of the most conserved branches of ER stress, was found to be involved in this process. H2O2 activated the phosphorylation of PERK, upregulated the activating transcription factor 4 (ATF4) and C/EBP homologous protein (CHOP) expression, and subsequently initiated cell apoptosis, which were significantly reversed by 1,25-(OH)2D3 pretreatment. In addition, GSK2606414, a specific inhibitor of PERK, suppressed PERK phosphorylation and reduced the expressions of ATF4 and CHOP, leading to a significant decrease in β cell apoptosis induced by H2O2. Taken together, the present findings firstly demonstrated that 1,25-(OH)2D3 could prevent MIN6 cells against ER stress-associated apoptosis by inhibiting the PERK-ATF4-CHOP pathway. Therefore, our results suggested that 1,25-(OH)2D3 might serve as a potential therapeutic target for preventing pancreatic β cell destruction in T1DM.Nitrogen is a most important nutrient resource for Escherichia coli and other bacteria that harbor the glnKamtB operon, a high-affinity ammonium uptake system highly interconnected with cellular metabolism. Although this system confers an advantage to bacteria when growing under nitrogen-limiting conditions, little is known about the impact of these genes on microbial fitness under nutrient-rich conditions. Here, the genetically tractable E. coli BW25113 strain and its glnKamtB-null mutant (JW0441) were used to analyze the impact of GlnK-AmtB on growth rates and oxidative stress tolerance. Strain JW0441 showed a shorter initial lag phase, higher growth rate, higher citrate synthase activity, higher oxidative stress tolerance and lower expression of serA than strain BW25113 under nutrient-rich conditions, suggesting a fitness cost to increase metabolic plasticity associated with serine metabolism. The overexpression of serA in strain JW0441 resulted in a decreased growth rate and stress tolerance in nutrient-rich conditions similar to that of strain BW25113, suggesting that the negative influence on bacterial fitness imposed by GlnK-AmtB can be traced to the control of serine biosynthesis.