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This case report documents a patient with a Class II skeletal malocclusion and suspected obstructive sleep apnea who underwent a combined mandibular inverted L osteotomy and total subapical osteotomy. The surgery involved a single-piece Lefort 1 osteotomy of the maxilla, bilateral inverted L osteotomies of the mandible, and a total mandibular subapical osteotomy. After the patient's pre-surgical orthodontic phase was completed, a traditional bilateral sagittal split osteotomy (BSSO) was initially planned to achieve mandibular advancement. However, the large horizontal and yaw correction required for the patient's mandibular teeth made a BSSO alone unrealistic. The virtual surgical plan (VSP) indicated that a subapical osteotomy was necessary, and due to the extension of the total subapical segment, an inverted L osteotomy was added to benefit the subapical osteotomy. The patient's surgery was successful, and the results were satisfactory.

Abstract Background Carbapenemase-producing Enterobacterales (CPE) poses a significant challenge to infection control in healthcare settings. Active screening is recommended to prevent intra-hospital CPE transmission. Methods CPE screening was initiated at a 660-bed hospital in South Korea in September 2018, targeting patients previously colonized/infected or admitted to outside healthcare facilities (HCFs) within 1 month. Universal intensive care unit (ICU) screening was performed at the time of admission. After a hospital-wide CPE outbreak in July-September 2019, the screening program was enhanced by extending the indications (admission to any HCF within 6 months, receipt of hemodialysis) with weekly screening of ICU patients. The initial screening method was changed from screening cultures to the Xpert Carba-R assay. The impact was assessed by comparing the CPE incidence per 1000 admissions before (phase 1, September 2018-August 2019) and after instituting the enhanced screening program (phase 2, September 2019-December 2020). Results A total of 13,962 (2,149 and 11,813 in each phase) were screened as indicated, among 49,490 inpatients, and monthly screening compliance increased from 18.3 to 93.5%. Compared to phase 1, the incidence of screening positive patients increased from 1.2 to 2.3 per 1,000 admissions (P = 0.005) during phase 2. The incidence of newly detected CPE patients was similar (3.1 vs. 3.4, P = 0.613) between two phases, but the incidence of hospital-onset CPE patients decreased (1.9 vs. 1.1, P = 0.018). A significant decrease was observed (0.5 to 0.1, P = 0.014) in the incidence of patients who first confirmed CPE positive through clinical cultures without a preceding positive screening. Compared to phase 1, the median exposure duration and number of CPE contacts were also markedly reduced in phase 2: 10.8 days vs. 1 day (P

Telacebec is a new anti-tuberculosis agent with promising therapeutic activity and a favorable safety profile. This study aimed to characterize the pharmacokinetics of telacebec via interspecies scaling and population pharmacokinetic modeling for the prediction of human pharmacokinetics. Preclinical pharmacokinetic data were obtained from mice, rats, and dogs following intravenous and oral doses of telacebec. A population pharmacokinetic model was developed to describe the pharmacokinetic data from all three species. The disposition parameters were well correlated with the body weight for all species using an allometric equation. Thus, the allometric scaling was incorporated into the population pharmacokinetic model, which could simultaneously describe the plasma concentration vs. time data from all preclinical studies as well as the Phase 1A clinical study. The developed model was used to predict the pharmacokinetics of telacebec after IV injection, including the clearance (CL) of 168.58 [118.86 – 238.73] mL/min and volume of distribution (Vss) of 968.84 [396.87 – 2831.31] L for 80-kg human. The absolute bioavailability of telacebec in humans in the fed state was estimated as 70.34 ± 9.91%. Finally, the population pharmacokinetic model with allometric scaling was utilized to simulate the plasma concentration vs. time profiles of telacebec after multiple oral doses in humans. The model-predicted profiles well agreed with the observed data in Phase 1B clinical trial. The present pharmacokinetic model may help better understand the activity of telacebec, leading to the design of optimal dosing regimens and new formulation development.

Abstract Liraglutide is a glucagon-like peptide-1 (GLP-1) analog that has been utilized for the treatment of type 2 diabetes mellitus. Liraglutide at a higher dose also shows beneficial effects in weight loss, which prompted its widespread use as an anti-obesity drug. The potential of liraglutide to treat Alzheimer’s disease and cognitive impairment has also been suggested. Nevertheless, the pharmacokinetics of liraglutide, including its distribution to the brain, has not been fully characterized. Therefore, this study aimed to develop a simple and sensitive bioanalytical method using liquid chromatography–tandem mass spectrometry (LC–MS/MS) and determine the pharmacokinetics and brain distribution of liraglutide in rats. Liraglutide in the rat plasma and brain tissue homogenates was extracted by protein precipitation using methanol. A gradient elution profile was used for chromatographic separation with mobile phases comprising 0.3% formic acid in water and 0.3% formic acid in acetonitrile. The mass spectrometry was operated in the positive electrospray ionization with multiple reaction monitoring mode. The lower limit of quantification of the present LC–MS/MS was 1 ng/mL in the plasma and 2 ng/mL in the brain tissue. Following intravenous injection (0.05 mg/kg, n = 5), plasma concentrations of liraglutide decreased monoexponentially with an average half-life of 3.67 h. The estimated absolute bioavailability of liraglutide after subcutaneous injection was 13.16%. Brain distribution of liraglutide was not significant, with the tissue-to-plasma partition coefficient (K p) of liraglutide less than 0.00031. However, the concentrations of liraglutide were significantly different in the different brain regions following IV injection. In the brain, liraglutide concentrations were the highest in the hypothalamus, followed by the cerebellum and cerebrum. The present LC–MS/MS assay and the pharmacokinetic results may be helpful to understand better the effect of liraglutide in the brain for further preclinical and clinical studies of liraglutide.

Abstract Prostate specific membrane antigen (PSMA) is known to be overexpressed in prostate cancer cells, providing as a diagnostic and therapeutic target for prostate cancer. A lutetium-labeled PSMA targeted ligand, 177Lu-DOTA-PSMA-GUL is a novel radiopharmaceutical, which has been developed for the treatment of prostate cancer. While the GUL domain of 177Lu-DOTA-PSMA-GUL binds to the antigen, the beta-emitting radioisotope, 177Lu-labeled DOTA, interacts with prostate cancer cells. However, the in vivo pharmacokinetics of intact 177Lu-DOTA-PSMA-GUL has never been characterized. This study aimed to evaluate the pharmacokinetics and tissue distribution of the radiopharmaceutical in rats by using its stable isotope-labeled analog, 175Lu-DOTA-PSMA-GUL. A sensitive liquid chromatography-tandem mass spectrometry (LC–MS/MS) analysis of 175Lu-DOTA-PSMA-GUL was developed and validated. Following intravenous injection, the plasma concentration–time profiles of 175Lu-DOTA-PSMA-GUL showed a multi-exponential decline with the average elimination half-life of 0.30 to 0.33 h. Systemic exposure increased with the dose and renal excretion is the major elimination route. Tissue distribution of 175Lu-DOTA-PSMA-GUL was most substantial in kidneys, followed by the prostate. The developed LC–MS/MS assay and the in vivo pharmacokinetic data of 175Lu-DOTA-PSMA-GUL would provide helpful information for further clinical studies to be developed as a novel therapeutic agent for prostate cancer.

Endometrial cancer (EC) is one of the most pervasive malignancies in females worldwide. HOXA5 is a member of the homeobox (HOX) family and encodes the HOXA5 protein. HOXA5 is associated with various cancers; however, its association with EC remains unclear. This study aimed to determine the association between HOXA5 gene expression and the prognosis of endometrioid adenocarcinoma, a subtype of EC (EAEC). Microarray data of HOXA5 were collected from the Gene Expression Omnibus datasets, consisting of 79 samples from GSE17025 and 20 samples from GSE29981. RNA-sequencing, clinical, and survival data on EC were obtained from The Cancer Genome Atlas cohort. Survival analysis revealed that HOXA5 overexpression was associated with poor overall survival in patients with EAEC (p = 0.044, HR = 1.832, 95% CI = 1.006–3.334). Cox regression analysis revealed that HOXA5 was an independent risk factor for poor prognosis in EAEC. The overexpression of HOXA5 was associated with a higher histological grade of EAEC, and it was also associated with TP53 mutation or the high copy number of EC. Our findings suggest the potential of HOXA5 as a novel biomarker for predicting poor survival outcomes in patients with EAEC.

Acute stroke management is critically time-sensitive and challenging. Blood-based biomarkers that can differentiate acute ischemic stroke (IS) from hemorrhagic stroke (HS) can greatly facilitate triage and early management. Admission blood samples obtained within 6 h of stroke symptom onset were analyzed in a derivation/validation design. GFAP, N-FL, NT-proBNP, copeptin, neutrophils (%), NLR, and platelet counts were assessed in the derivation cohort. The informative markers and the derived cutoff values were evaluated in the validation cohort. GFAP > 703 pg/mL showed a PPV of 76.9% and NPV of 95.8% for differentiating HS from IS. Multiple logistic regression analysis showed that GFAP and NT-proBNP were independent variables associated with IS and HS differentiation. Furthermore, applying a combined cutoff (GFAP > 703 pg/mL and NT-proBNP ≤ 125 pg/mL) for HS detection increased the PPV in both the derivation and validation cohorts (93.3% and 100%, respectively). GFAP and NT-proBNP levels were validated as informative blood biomarkers in the differentiation of IS and HS and using a combination of GFAP and NT-proBNP is suggested as a feasible strategy to differentiate stroke subtypes in the hyperacute phase of stroke.

Comprehensive assessment of SARS-CoV-2 antibodies against antigenic epitopes and cross-neutralization on variants is essential to monitor after infection or vaccination. From 32 COVID-19 patients and 40 vaccinated individuals [20 Oxford–AstraZeneca (AZ) and 20 Pfizer–BioNTech (BNT)], 348 serial sera are collected until 40 days after infection and 3 months after homologous booster vaccination. Antibody levels were monitored using a multiplex-bead assay including variant spike antigens, Roche (S1/RBD total) and a surrogate virus neutralization test (GenScript). Anti-S/S1/RBD levels were higher than anti-S2/N levels from 2 weeks after infection and were higher in severe infection (P < 0.05). Vaccination showed highest antibody levels after 1-month booster and had consistently high levels in the order of anti-full S, anti-RBD, anti-S1 and anti-S2. Infection induced higher anti-S2/N levels than prime vaccination (P < 0.05). Three months after BNT/BNT vaccination, antibody levels against S1/RBD and 23 variant antigens were higher than post-infection or AZ groups (P < 0.05). Regarding intraindividual changes from post-prime to post-boost vaccination, boost induced a 1.1- to 3.9-fold increase on multiplex-bead assay, 22.8- to 24.2-fold on Roche assay and 22.8- to 24.2-fold on GenScript assay. Post-prime levels by multiplex-bead assay predicted post-boost levels, but Roche and GenScript results were not predictive in the AZ group. The kinetics of SARS-CoV-2 antibody levels vary depending on the antigenic epitopes, assay kit, disease severity or vaccine type. Assessing seroconversion using multiplex-bead assays may contribute to monitoring the disease course, adjusting vaccination strategies, and accelerating vaccination efficacy.

During the measles epidemic in 2019, in-hospital transmission of measles contributed to more than two-thirds of measles cases in South Korea, where measles is declared eliminated. This study aimed to examine measles seropositivity among healthcare workers (HCWs) in South Korea to help develop an effective measles prevention strategy for hospital settings. Measles IgG titer was tested in 1,579 HCWs working in a university-affiliated hospital and the measles-containing vaccine (MCV) immunization records of 870 HCWs were identified. The overall seropositivity was 92.0%, but the seropositivity and antibody titers were significantly low among HCWs aged 20–25 years (78.6%) and among one-dose vaccine recipients (86.7%). Among two-dose recipients, seropositivity was lower among young HCWs who received two doses during their childhood than among those who received the catch-up vaccination as part of job requirements (70.3% vs. 98.0%). Among 87 seronegative HCWs who received two-dose MMR vaccination, the seroconversion rate was 98.9%. A considerable proportion of young HCWs were potentially susceptible to measles despite receiving the two-dose vaccination during childhood because of the waning immunity against measles in a country with measles-eliminated status. Serological screening for measles of newly employed HCWs and MCV immunization of seronegative HCWs appears to be an effective prevention strategy.

Because of its greater binding affinity and longer half-life than native glucagon-like peptide-1 (GLP-1), the GLP-1 receptor agonist lixisenatide is commonly used to treat type 2 diabetes mellitus. This study aimed to establish a simple and robust liquid chromatography–tandem mass spectrometry (LC–MS/MS) approach for lixisenatide for in vivo pharmacokinetic investigation. Methanol-based protein precipitation with formic acid was exploited for plasma sample extraction, using esomeprazole as the internal standard. Gradient elution with 0.1% formic acid in distilled water and acetonitrile was utilized for chromatographic separation. Mass spectrometry was used to monitor the MRM transition at m/z 810.8 → 129.2 for lixisenatide. In rat plasma, lixisenatide had a lower limit of quantification of 10 ng/mL. The LC–MS/MS was applied to describe the pharmacokinetics of lixisenatide in rats following intravenous and subcutaneous dosing. The average half-life of lixisenatide was 0.37 ± 0.06 h after intravenous injection. The estimated subcutaneous bioavailability of lixisenatide was 2.17%. This LC–MS/MS analysis might be relevant in future research to create novel dosage formulations of lixisenatide and other GLP-1 receptor agonists with optimal therapeutic effectiveness.

Abstract In South Korea where the tuberculosis (TB) burden is intermediate, the risk of in-hospital transmission of TB remains high. We conducted a retrospective cohort study of 244 inpatients diagnosed with pulmonary TB (2015–2018) to evaluate the impact of the Xpert MTB/RIF assay (Xpert) screening on timely isolation. TB screening was performed with smear microscopy and a polymerase chain reaction test, and the Xpert was additionally used from November 2016. Among all patients with pulmonary TB, the median time-to-isolation was significantly reduced (22.6 vs. 69.7 h; p

Hexamethylenetetramine, an aldehyde-releasing agent, is used as a preservative in various food, cosmetics, and medical treatments, such as a treatment for urinary tract infections. It has been reported to be allergenic on contact with the skin, with the additional possibility of causing toxicity once absorbed systemically. Despite its potential toxicity, there are no reports on the in vivo bioavailability of hexamethylenetetramine following oral or dermal administration. In this study, we developed a new simple and sensitive LC–MS/MS method for the determination of hexamethylenetetramine in plasma and applied this method to characterize the toxicokinetics. The developed assay had a sufficient specificity and sensitivity for toxicokinetic characterization, and its accuracy and precision were verified. Following iv injection, the plasma concentration of hexamethylenetetramine showed mono exponential decay, with an elimination half-life of about 1.3 h. Following oral administration, the Tmax reached an average of 0.47 h and bioavailability was estimated as 89.93%. After percutaneous administration, it reached Cmax on average at 2.9–3.6 h. Although the absorption rate was relatively slow, its average bioavailability was calculated as 77.19–78.91%. Overall, most of the orally and percutaneously administered hexamethylenetetramine was absorbed into systemic circulation. The derived results in this study are expected to be utilized as the scientific evidence for further toxicokinetic study and risk assessment.

This study describes the epidemiological characteristics of coronavirus disease 2019 (COVID-19) based on reported cases from long-term care facilities. As of April 20th, 2020, 3 long-term care facilities in a metropolitan area of South Korea had reported cases of COVID-19. These facilities’ employees were presumed to be the sources of infection. There were 2 nursing hospitals that did not report any additional cases. One nursing home had a total of 25 cases, with an attack rate of 51.4% (95% CI 35.6–67.0), and a fatality rate of 38.9% (95% CI 20.3–61.4) among residents. The results from this study suggest that early detection and maintenance of infection control minimizes the risk of rapid transmission.

The aim of this study was to evaluate in vitro skin permeation and deposition, in vivo toxicokinetics, percutaneous absorption and tissue distribution of benzophenone-3 (BP-3) in rats. Four transdermal formulations containing BP-3 were prepared and evaluated for in vitro skin permeation and deposition of BP-3 using Franz diffusion cells. A gel formulation was used in subsequent in vivo percutaneous absorption due to its high in vitro skin permeation and deposition. Compared to intravenous (i.v.) injection, the prolonged terminal t1/2 (3.1 ± 1.6 h for i.v. injection and 18.3 ± 5.8 h for topical application) was observed indicating occurrence of flip-flop kinetics after topical application. The bioavailability of BP-3 after topical application was 6.9 ± 1.8%. The tissue-to-plasma partition coefficient (kp) for testis, considered a toxic target for BP-3, was less than 1. Overall, findings of this study may be useful for risk assessment of BP-3.

Tacrolimus is one of the most commonly used immunosuppressive agents in animal models of transplantation. However, in these models, oral administration is often problematic due to the lowered compliance associated with highly invasive surgery and due to malabsorption in the intestinal tract. Therefore, we carried out a study to determine the pharmacokinetics of tacrolimus after intramuscular (IM) injection and to determine the optimal IM dosing regimens in primate models. Six male cynomolgus monkeys (Macaca fascicularis) were used in the study. Doses of 0.1 mg/kg and 5 mg were administered via IM injection and oral administration, respectively, once to determine single-dose pharmacokinetics and once daily for 5 days to determine multiple-dose pharmacokinetics. According to pharmacokinetic model estimates, the inter- and intra-individual variabilities in bioavailability following IM injection were remarkably reduced compared with those following oral administration. Monte Carlo simulations revealed that Cpeak, Ctrough and AUC would also have less variability following IM injection compared with oral administration. In this study, we found that the pharmacokinetic characteristics of tacrolimus were more constant following IM injection compared with oral administration. These results suggest that IM injection can be an alternative route of administration fin non-human primate model studies. Keywords: Tacrolimus, Cynomolgus monkey, Intramuscular injection, Intra-individual variability

This study aimed to establish an extended design of experiment (DoE)-in vitro in vivo correlation (IVIVC) model that defines the relationship between formulation composition, in vitro dissolution, and in vivo pharmacokinetics. Fourteen sustained-release (SR) tablets of a model drug, donepezil, were designed by applying a mixture design of DoE and prepared by the wet granulation method. The in vitro dissolution patterns of donepezil SR tablets were described by Michaelis–Menten kinetics. The mathematical relationship describing the effects of SR tablet compositions on the in vitro dissolution parameter, i.e., the in vitro maximum rate of release (Vmax), was derived. The predictability of the derived DoE model was validated by an additional five SR tablets with a mean prediction error (PE%) of less than 3.50% for in vitro Vmax. The pharmacokinetics of three types of donepezil SR and the immediate-release (IR) tablets was assessed in Beagle dogs following oral administration (n = 3, each). Based on the plasma concentration-time profile, a population pharmacokinetic model was developed, and the in vivo dissolution of SR tablets, represented by in vivo Vmax, was estimated. By correlating the in vitro and in vivo Vmax, level A IVIVC was established. Finally, the extended DoE-IVIVC model was developed by integrating the DoE equation and IVIVC into the population pharmacokinetic model. The extended DoE-IVIVC model allowed one to predict the maximum plasma concentration (Cmax) and the area under the plasma concentration-time curve (AUC) of donepezil SR tablets with PE% less than 10.30% and 5.19%, respectively, by their formulation composition as an input. The present extended DoE-IVIVC model may provide a valuable tool to predict the effect of formulation changes on in vivo pharmacokinetic behavior, leading to the more efficient development of SR formulations. The application of the present modeling approaches to develop other forms of drug formulation may be of interest for future studies.

Nafamostat, a synthetic serine protease inhibitor, has been used for the treatment of inflammatory diseases such as pancreatitis. Recently, an increasing number of studies have shown the promising antiviral effects of nafamostat for the treatment of coronavirus disease-19 (COVID-19). This study aimed to develop a novel liquid chromatography–tandem mass spectrometry (LC-MS/MS) analysis and to characterize the pharmacokinetics of nafamostat in rats. Nafamostat in the rat plasma was extracted by solid phase extraction, and 13C6-nafamostat was used as an internal standard. The quantification limit of nafamostat in the rat plasma was 0.5 ng/mL. The LC-MS/MS method was fully validated and applied to characterize the pharmacokinetics of nafamostat in rats. Following intravenous injection (2 mg/kg), nafamostat in the plasma showed a multiexponential decline with an average elimination half-life (t1/2) of 1.39 h. Following oral administration of nafamostat solutions (20 mg/kg) in 10% dimethyl sulfoxide (DMSO) and in 10% DMSO with 10% Tween 80, nafamostat was rapidly absorbed, and the average oral bioavailability was 0.95% and 1.59%, respectively. The LC-MS/MS method and the pharmacokinetic information of nafamostat could be helpful for the further preclinical and clinical studies of nafamostat.

Objective Variations in hormone levels are a direct effect of epileptic discharges in both animals and humans, and seizure can affect the hypothalamus–pituitary–thyroid axis. The purpose of this study was to determine which parameters could affect the alternation of thyroid hormones in children experiencing seizure. Methods We retrospectively reviewed the medical records of 181 pediatric patients with seizure and compared three thyroid hormones (serum thyroid-stimulating hormone [TSH], free thyroxine [fT4], and triiodothyronine [T3]) between initial (admission to hospital) and follow-up (2 weeks later) testing. Results Multivariable logistic regression models were used to determine which six parameters (gender, age, seizure accompanying with fever, seizure type, seizure duration, and anti-epileptic drug medication) could help to explain the higher initial TSH levels in pediatric seizure. Only seizure duration in patients with an increase in TSH levels was significantly longer compared with patients with normal TSH at the time of initial testing. Conclusion Neuronal excitability by seizure can cause thyroid hormonal changes, which likely reflects changes in hypothalamic function.

Gastric cancer, also known as stomach cancer, is a cancer that develops from the lining of the stomach. Accumulated evidence and epidemiological studies have indicated that bioactive food components from natural products play an important role in gastric cancer prevention and treatment, although its mechanism of action has not yet been elucidated. Particularly, experimental studies have shown that natural bioactive food products display a protective effect against gastric cancer via numerous molecular mechanisms, such as suppression of cell metastasis, anti-angiogenesis, inhibition of cell proliferation, induction of apoptosis, and modulation of autophagy. Chemotherapy remains the standard treatment for advanced gastric cancer along with surgery, radiation therapy, hormone therapy, as well as immunotherapy, and its adverse side effects including neutropenia, stomatitis, mucositis, diarrhea, nausea, and emesis are well documented. However, administration of naturally occurring bioactive phytochemical food components could increase the efficacy of gastric chemotherapy and other chemotherapeutic resistance. Additionally, several studies have suggested that bioactive food components with structural stability, potential bioavailability, and powerful bioactivity are important to develop novel treatment strategies for gastric cancer management, which may minimize the adverse effects. Therefore, the purpose of this review is to summarize the potential therapeutic effects of natural bioactive food products on the prevention and treatment of gastric cancer with intensive molecular mechanisms of action, bioavailability, and safety efficacy.

Gastroretentive (GR) systems are designed to prolong gastric residence time to allow sustained absorption and improve the oral bioavailability of drugs with a narrow absorption window in the upper part of the gastrointestinal tract. The present study aimed to develop a GR system for acyclovir using 3D printing technology and evaluate its in vivo pharmacokinetics after oral administration in Beagle dogs. The system consisted of a gastro-floating device, which can float in the gastric fluid, prepared by a fused deposition modeling 3D printer and conventional acyclovir sustained-release (SR) tablet. The acyclovir SR tablet was inserted to the floating device to allow sustained release of the drug in the stomach. The buoyancy and sustained-release property of the developed GR system were determined using an in vitro dissolution test, in vivo pharmacokinetic study, and abdominal X-ray imaging in Beagle dogs. The in vivo dissolution profiles of the GR system were also predicted based on the in vivo pharmacokinetic data using a population pharmacokinetic (POP-PK) model. In the dissolution test, the sustained-release characteristic of the GR system was identified with a time corresponding to 80% dissolution (T80) of 2.52 h. Following oral administration of the GR system, the time to reach the maximum concentration (Tmax) of acyclovir was significantly prolonged, whereas the maximum concentration (Cmax) decreased and the area under the curve increased compared with those obtained after the administration of immediate-release and SR tablets, indicating prolonged absorption. By X-ray imaging, we showed that the developed GR system stayed in the stomach for more than 12 h. The POP-PK model successfully described the observed plasma concentration-time data and predicted the in vivo biphasic dissolution profiles of the GR system, which was significantly different from the in vitro dissolution. The developed GR system could be applied to various drugs and had great prospects in the design and development of novel controlled-release formulations.

This study aimed to develop a novel oral drug delivery system for gastroretentive sustained drug release by using a capsular device. A capsular device that can control drug release rates from the inner immediate release (IR) tablet while floating in the gastric fluid was fabricated and printed by a fused deposition modeling 3D printer. A commercial IR tablet of baclofen was inserted into the capsular device. The structure of the capsular device was optimized by applying a design of experiment approach to achieve sustained release of a drug while maintaining sufficient buoyancy. The 2-level factorial design was used to identify the optimal sustained release with three control factors: size, number, and height of drug-releasing holes of the capsular device. The drug delivery system was buoyant for more than 24 h and the average time to reach 80% dissolution (T80) was 1.7–6.7 h by varying the control factors. The effects of the different control factors on the response factor, T80, were predicted by using the equation of best fit. Finally, drug delivery systems with predetermined release rates were prepared with a mean prediction error ≤ 15.3%. This approach holds great promise to develop various controlled release drug delivery systems.

This study was aimed to examine the effect of L-arginine (ARG) exposure on the disposition of asymmetric dimethylarginine (ADMA) in human endothelial cells. Although the role of ADMA as an inhibitor of endothelial nitric oxide synthase (eNOS) is well-recognized, cellular interactions between ARG and ADMA are not well-characterized. EA.hy926 human vascular endothelial cells were exposed to 15N4-ARG, and the concentrations of 15N4-ARG and ADMA in the cell lysate and incubation medium were determined by a liquid chromatography-electrospray tandem mass spectrometry (LC-MS/MS) assay. Nitric oxide (NO) production was estimated by utilizing cumulative nitrite concentration via a fluorometric assay. Cells incubated with 15N4-ARG exhibited enhanced nitrite production as well as 15N4-ARG cellular uptake. These changes were accompanied by a decrease in cellular ADMA level and increase in extracellular ADMA level, indicating an efflux of endogenous ADMA from the cell. The time courses of ADMA efflux as well as nitrite accumulation in parallel with 15N4-ARG uptake were characterized. Following preincubation with 15N4-ARG and D7-ADMA, the efflux of cellular 15N4-ARG and D7-ADMA was significantly stimulated by high concentrations of ARG or ADMA in the incubation medium, demonstrating trans-stimulated cellular transport of these two amino acids. D7-ADMA metabolism was inhibited in the presence of added ARG. These results demonstrated that in addition to an interaction at the level of eNOS, ARG and ADMA may mutually influence their cellular availability via transport and metabolic interactions.

This study aimed to establish a physiologically relevant in vitro-in vivo correlation (IVIVC) model reflecting site-dependent dissolution kinetics for sildenafil based on population-pharmacokinetic (POP-PK) modeling. An immediate release (IR, 20 mg) and three sustained release (SR, 60 mg) sildenafil tablets were prepared by wet granulation method. In vitro dissolutions were determined by the paddle method at pH 1.2, 4.5, and 6.8 media. The in vivo pharmacokinetics were assessed after oral administration of the prepared IR and SR formulations to Beagle dogs (n = 12). The dissolution of sildenafil from SR formulations was incomplete at pH 6.8, which was not observed at pH 1.2 and pH 4.5. The relative bioavailability was reduced with the decrease of the dissolution rate. Moreover, secondary peaks were observed in the plasma concentration-time curves, which may result from site-dependent dissolution. Thus, a POP-PK model was developed to reflect the site-dependent dissolution by separately describing the dissolution and absorption processes, which allowed for estimation of the in vivo dissolution of sildenafil. Finally, an IVIVC was established and validated by correlating the in vitro and in vivo dissolution rates. The present approach may be applied to establish IVIVC for various drugs with complex dissolution kinetics for the development of new formulations.

Desoxo-narchinol A is one of the major active constituents from Nardostachys jatamansi, which has been reported to possess various pharmacological activities, including anti-inflammatory, antioxidant, and anticonvulsant activity. A simple and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for the quantification of desoxo-narchinol A in two different biological matrices, i.e., rat plasma and mouse plasma, using sildenafil as an internal standard (IS). The method involved simple protein precipitation with acetonitrile and the analyte was separated by gradient elution using 100% acetonitrile and 0.1% formic acid in water as a mobile phase. The MS detection was performed with a turbo electrospray in positive ion mode. The lower limit of quantification was 10 ng/mL in both rat and mouse plasma. Intra- and inter-day accuracies were in the ranges of 97.23−104.54% in the rat plasma and 95.90−110.11% in the mouse plasma. The precisions were within 8.65% and 6.46% in the rat and mouse plasma, respectively. The method was applied to examine the pharmacokinetics of desoxo-narchinol A, and the oral bioavailability of desoxo-narchinol A was 18.1% in rats and 28.4% in mice. The present results may be useful for further preclinical and clinical studies of desoxo-narchinol A.

The aim of the present study was to assess the regional absorption of fimasartan by an improved in situ absorption method in comparison with the conventional in situ single-pass perfusion method in rats. After each gastrointestinal segment of interest was identified, fimasartan was injected into the starting point of each segment and the unabsorbed fimasartan was discharged from the end point of the segment. Blood samples were collected from the jugular vein to evaluate the systemic absorption of the drug. The relative fraction absorbed (Fabs,relative) values in the specific gastrointestinal region calculated based on the area under the curve (AUC) values obtained after the injection of fimasartan into the gastrointestinal segment were 8.2% ± 3.2%, 23.0% ± 12.1%, 49.7% ± 11.5%, and 19.1% ± 11.9% for the stomach, duodenum, small intestine, and large intestine, respectively, which were comparable with those determined by the conventional in situ single-pass perfusion. By applying the fraction of the dose available at each gastrointestinal segment following the oral administration, the actual fraction absorbed (F′abs) values at each gastrointestinal segment were estimated at 10.9% for the stomach, 27.1% for the duodenum, 40.7% for the small intestine, and 5.4% for the large intestine, which added up to the gastrointestinal bioavailability (FX·FG) of 84.1%. The present method holds great promise to assess the regional absorption of a drug and aid to design new drug formulations.

Excessive systemic inflammation following sepsis, trauma or burn could lead to multi-organ damage and death. Bone marrow stromal cells (BMSCs), commonly referred to as mesenchymal stem cells (MSCs), has been studied in several immune-associated diseases in human and animal by modulating the inflammatory response. Adipose tissue derived mesenchymal stem cells (ATSCs), which can be obtained more easily, compared with BMSCs, has emerged as an attractive alternative MSCs source for cell therapy. We investigated the therapeutic effects of human ATSCs (hATSCs) in endotoxemic rat model and their capacity to modulate the inflammatory response. Endotoxemia was induced with Lipopolysaccaride intravenously injection (LPS, 10mg/kg). Animals were divided into the following three groups: (1) saline + saline (n=5), (2) LPS + saline (n=5) and (3) LPS + hATSCs (2x106) (n=5). The administration of LPS caused a consistent systemic inflammatory responses, increased concentrations of the pro-inflammatory cytokines that have an important role in sepsis. Treatment of endotoxemia with hATSCs decreased the level of inflammatory cytokines both in serum and in the lung, reduced inflammatory changes in the lung, prevented apoptosis in the kidney and improved multi-organ injury. In conclusion, our data demonstrates that hATSCs regulate the immue/inflammatory responses and improve multi-organ injury and they could be attractive candidates for cell therapy to treat endotoxemia.

This study examined the effects of esomeprazole on aceclofenac pharmacokinetics and gastrointestinal complications in rats. Aceclofenac alone, or in combination with esomeprazole, was orally administered to male Sprague-Dawley rats. Plasma concentrations of aceclofenac, its major metabolite diclofenac, and esomeprazole were simultaneously determined by a novel liquid chromatography-tandem mass spectrometry method. Gastrointestinal damage was determined by measuring ulcer area and ulcer lesion index of the stomach. Oral administration of aceclofenac induced significant gastric ulceration, which was inhibited by esomeprazole administration. Following concurrent administration of aceclofenac and esomeprazole, overall pharmacokinetic profiles of aceclofenac and metabolic conversion to diclofenac were unaffected by esomeprazole. Aceclofenac metabolism and pharmacokinetics were not subject to significant food effects, whereas bioavailability of esomeprazole decreased in fed compared to fasting conditions. In contrast, the pharmacokinetics of aceclofenac and esomeprazole were significantly altered by different dosing vehicles. These results suggest that co-administration of esomeprazole with aceclofenac may reduce aceclofenac-induced gastrointestinal complications without significant pharmacokinetic interactions. The optimal combination and clinical significance of the benefits of the combination of aceclofenac and esomeprazole need to be further evaluated.

Minoxidil directly promotes hair growth via the stimulation of dermal papilla (DP) and epithelial cells. Alternatively, there is little evidence for indirect promotion of hair growth via stimulation of adipose-derived stem cells (ASCs). We investigated whether minoxidil stimulates ASCs and if increased growth factor secretion by ASCs facilitates minoxidil-induced hair growth. Telogen-to-anagen induction was examined in mice. Cultured DP cells and vibrissae hair follicle organ cultures were used to further examine the underlying mechanisms. Subcutaneous injection of minoxidil-treated ASCs accelerated telogen-to-anagen transition in mice, and increased hair weight at day 14 post-injection. Minoxidil did not alter ASC proliferation, but increased migration and tube formation. Minoxidil also increased the secretion of growth factors from ASCs, including chemokine (C-X-C motif) ligand 1 (CXCL1), platelet-derived endothelial cell growth factor (PD-ECGF), and platelet-derived growth factor-C (PDGF-C). Minoxidil increased extracellular signal–regulated kinases 1/2 (ERK1/2) phosphorylation, and concomitant upregulation of PD-ECGF and PDGF-C mRNA levels were attenuated by an ERK inhibitor. Subcutaneous injection of CXCL1, PD-ECGF, or PDGF-C enhanced anagen induction in mice, and both CXCL1 and PDGF-C increased hair length in ex vivo organ culture. Treatment with CXCL1, PD-ECGF, or PDGF-C also increased the proliferation index in DP cells. Finally, topical application of CXCL1, PD-ECGF, or PDGF-C with 2% minoxidil enhanced anagen induction when compared to minoxidil alone. Minoxidil stimulates ASC motility and increases paracrine growth factor signaling. Minoxidil-stimulated secretion of growth factors by ASCs may enhance hair growth by promoting DP proliferation. Therefore, minoxidil can be used as an ASC preconditioning agent for hair regeneration.

Pungent spice constituents such as piperine, capsaicin and [6]-gingerol consumed via daily diet or traditional Chinese medicine, have been reported to possess various pharmacological activities. These dietary phytochemicals have also been reported to inhibit P-glycoprotein (P-gp) in vitro and act as an alternative to synthetic P-gp modulators. However, the in vivo effects on P-gp inhibition are currently unknown. This study aimed to test the hypothesis that phytochemical P-gp inhibitors, i.e., piperine, capsaicin and [6]-gingerol, modulate the in vivo tissue distribution of doxorubicin, a representative P-gp substrate. Mice were divided into four groups and each group was pretreated with intraperitoneal injections of control vehicle, piperine, capsaicin, or [6]-gingerol and doxorubicin (1 mg/kg) was administered via the penile vein. The concentrations of the phytochemicals and doxorubicin in the plasma and tissues were determined by LC-MS/MS. The overall plasma concentration-time profiles of doxorubicin were not significantly affected by piperine, capsaicin, or [6]-gingerol. In contrast, doxorubicin accumulation was observed in tissues pretreated with piperine or capsaicin. The tissue to plasma partition coefficients, Kp, for the liver and kidney were higher in the piperine-pretreated group, while the Kp for kidney, brain and liver were higher in the capsaicin-pretreated group. [6]-Gingerol did not affect doxorubicin tissue distribution. The data demonstrated that the phytochemicals modulated doxorubicin tissue distribution, which suggested their potential to induce food-drug interactions and act as a strategy for the delivery of P-gp substrate drugs to target tissues and tumors.

S-1 (TS-1®) is an oral fluoropyrimidine anticancer agent containing tegafur, oteracil, and gimeracil. Sipjeondaebo-tang (SDT) is a traditional oriental herbal medicine that has potential to alleviate chemotherapy-related adverse effects. The aim of the present study was to evaluate the effect of SDT on the pharmacokinetics of S-1. Sprague-Dawley rats were pretreated with a single dose or repeated doses of SDT for seven consecutive days (1200 mg/kg/day). After the completion of pretreatment with SDT, S-1 was orally administered and plasma concentrations of tegafur, its active metabolite 5-FU, and gimeracil were determined by liquid chromatography-tandem mass spectrometry (LC/MS/MS). A population pharmacokinetic model was developed to evaluate the effect of SDT on pharmacokinetics of tegafur and 5-FU. Although a single dose of SDT did not have any significant effect, the absorption rate of tegafur decreased, and the plasma levels of 5-FU reduced significantly in rats pretreated with SDT for seven days in parallel to the decreased gimeracil concentrations. Population pharmacokinetic modeling also showed the enhanced elimination of 5-FU in the SDT-pretreated group. Repeated doses of SDT may inhibit the absorption of gimeracil, an inhibitor of 5-FU metabolism, resulting in enhanced elimination of 5-FU and decrease its plasma level.

Gemcitabine and erlotinib are the chemotherapeutic agents used in the treatment of various cancers and their combination is being accepted as a first-line treatment of advanced pancreatic cancer. Hyangsayukgunja-tang (HYT) is a traditional oriental medicine used in various digestive disorders and potentially helpful to treat gastrointestinal adverse effects related to chemotherapy. The present study was aimed to evaluate the effect of HYT on the pharmacokinetics of gemcitabine and erlotinib given simultaneously in rats. Rats were pretreated with HYT at an oral dose of 1200 mg/kg/day once daily for a single day or 14 consecutive days. Immediately after pretreatment with HYT, gemcitabine and erlotinib were administered by intravenous injection (10 mg/kg) and oral administration (20 mg/kg), respectively. The effects of HYT on pharmacokinetics of the two drugs were estimated by non-compartmental analysis and pharmacokinetic modeling. The pharmacokinetics of gemcitabine and erlotinib were not altered by single dose HYT pretreatment. However, the plasma levels of OSI-420 and OSI-413, active metabolites of erlotinib, were significantly decreased in the multiple dose HYT pretreatment group. The pharmacokinetic model estimated increased systemic clearances of OSI-420 and OSI-413 by multiple doses of HYT. These data suggest that HYT may affect the elimination of OSI-420 and OSI-413.

Piscidin-1 (Pis-1) is a linear antibacterial peptide derived from mast cells of aquacultured hybrid striped bass that comprises 22 amino acids with a phenylalanine-rich amino-terminus. Pis-1 exhibits potent antibacterial activity against pathogens but is not selective for distinguishing between bacterial and mammalian cells. To determine the key residues for its antibacterial activity and those for its cytotoxicity, we investigated the role of each Phe residue near the N-terminus as well as the Val10 residue located near the boundary of the hydrophobic and hydrophilic sectors of the helical wheel diagram. Fluorescence dye leakage and tryptophan fluorescence experiments were used to study peptide-lipid interactions, showing comparable depths of insertion of substituted peptides in different membranes. Phe2 was found to be the most deeply inserted phenylalanine in both bacterial- and mammalian-mimic membranes. Each Phe was substituted with Ala or Lys to investigate its functional role. Phe2 plays key roles in the cytotoxicity as well as the antibacterial activities of Pis-1, and Phe6 is essential for the antibacterial activities of Pis-1. We also designed and synthesized a piscidin analog, Pis-V10K, in which Lys was substituted for Val10, resulting in an elevated amphipathic α-helical structure. Pis-V10K showed similar antibacterial activity (average minimum inhibitory concentration (MIC) = 1.6 µM) to Pis-1 (average MIC = 1.5 µM). However, it exhibited much lower cytotoxicity than Pis-1. Lys10-substituted analogs, Pis-F1K/V10K, Pis-F2K/V10K, and Pis-F6K/V10K in which Lys was substituted for Phe retained antibacterial activity toward standard and drug-resistant bacterial strains with novel bacterial cell selectivity. They exert anti-inflammatory activities via inhibition of nitric oxide production, TNF-α secretion, and MIP-1 and MIP-2 production. They may disrupt the binding of LPS to toll-like receptors, eventually suppressing MAPKs-mediated signaling pathways. These peptides may be good candidates for the development of peptide antibiotics with potent antibacterial activity but without cytotoxicity.

We present an experimental observation and comprehensive theory that address the effect of interaction on the phase transition in a many-body system, which is far from equilibrium and does not have detailed balance. In the resonantly driven cold atomic trap, we observe kinetic phase transition (KPT) that is manifested by substantial enhancement of fluctuations, similar to the first-order phase transition in thermal equilibrium. Moreover, we can control the attractive interaction between atoms trapped in the coexisting states by adjusting the total number of atoms, which induces shift of the phase boundaries of KPT. The demonstrated effect is the many-body analogue of KPT that was previously predicted and observed in a single-driven oscillator. Our work provides a unique model platform for quantitative study of nonequilibrium nonlinear dynamics in many-body systems.