Physiologically based pharmacokinetic modeling to predict maternal pharmacokinetics and fetal carbamazepine exposure during pregnancy

Carbamazepine is an antiepileptic drug commonly used in pregnant women, during which the physiological changes may affect its efficacy. The aim of this study was to establish a physiologically based pharmacokinetic (PBPK) model of carbamazepine and its active metabolite carbamazepine-10,11-epoxide, and simulate maternal and fetal pharmacokinetic changes of carbamazepine and carbamazepine-10,11-epoxide in different trimesters and propose dose adjustment. We established pregnancy PBPK models for carbamazepine and carbamazepine-10,11-epoxide in PK-Sim® and Mobi® and validated the models with observed data from clinical reports. The placental transfer parameters obtained using different methods were also imported into the model and compared with the observed data to establish and validate fetal pharmacokinetic curves. The simulated results showed that mean steady-state trough plasma concentration of carbamazepine decreased by 27, 43.1, and 52 % during the first, second, and third trimesters, respectively. Therefore, to achieve an optimum therapeutic concentration, administering at least 1.4, 1.8, and 2.1 times the baseline dose of carbamazepine in the first, second, and third trimesters, respectively can be used as a dose reference. In conclusion, this study established and validated a pregnancy PBPK model of carbamazepine and carbamazepine-10,11-epoxide to assess exposure in pregnant women and fetuses, which provided a reference for the dosage adjustment of carbamazepine during pregnancy.

Descriptive study of COVID-19 vaccinations and infections within an NHS workforce

BACKGROUND

Healthcare workers were a priority group for coronavirus disease 2019 (COVID-19) vaccination during the pandemic. Occupational exposure may account for some of the increased risk faced.

AIMS

Describe COVID-19 vaccine uptake and infection rates in staff across a large NHS board in Scotland to better understand occupational risk during the pandemic.

METHODS

Descriptive cross-sectional study. Demographic data were extracted on 5 August 2021 from 26 058 members of staff. COVID-19 vaccination status and positive polymerase chain reaction (PCR) results were extracted on two separate dates to describe the timeline of staff infections between March 2020 and January 2022.

RESULTS

There was high uptake of all three vaccine doses across all demographic groups in hospital staff. PCR positivity decreased with increasing age and Scottish Index of Multiple Deprivation score. Staff and nosocomial COVID-19 infections followed peaks in community infection rates.

CONCLUSIONS

NHS Lothian is a typical NHS workforce with good vaccine uptake. Beyond very early cases, there seems to be minimal evidence of occupational acquisition of COVID-19. The large number of nosocomial infections at the start of the pandemic may, in fact, reflect lack of community testing at this time. Despite protection from high vaccine coverage, job type and good Infection Prevention and Control practices, it seems that staff remain at high risk of catching the highly transmissible omicron variant from the community rather than work.

Epigenetic regulation and epigenetic memory resetting during plant rejuvenation

Reversal of plant developmental status from the mature to the juvenile phase, thus leading to the restoration of the developmental potential, is referred to as plant rejuvenation. It involves multilayer regulation, including resetting gene expression patterns, chromatin remodeling, and histone modifications, eventually resulting in the restoration of juvenile characteristics. Although plants can be successfully rejuvenated using some forestry practices to restore juvenile morphology, physiology, and reproductive capabilities, studies on the epigenetic mechanisms underlying this process are in the nascent stage. This review provides an overview of the plant rejuvenation process and discusses the key epigenetic mechanisms involved in DNA methylation, histone modification, and chromatin remodeling in the process of rejuvenation, as well as the roles of small RNAs in this process. Additionally, we present new inquiries regarding the epigenetic regulation of plant rejuvenation, aiming to advance our understanding of rejuvenation in sexually and asexually propagated plants. Overall, we highlight the importance of epigenetic mechanisms in the regulation of plant rejuvenation, providing valuable insights into the complexity of this process.

Physiologically-Based Pharmacokinetic Modeling of Anti-Tumor Necrosis Factor Agents for Inflammatory Bowel Disease Patients to Predict the Withdrawal Time in Pregnancy and Vaccine Time in Infants

Anti-tumor necrosis factor (anti-TNF) agents are widely applied for patients with inflammatory bowel disease (IBD); however, the timing of the last dosing for IBD pregnancy and time to elimination in anti-TNF agent-exposed infants is controversial. This study aimed to determine the optimal timing for the last dosing of anti-TNF agents (infliximab, adalimumab, and golimumab) in pregnant women with IBD, as well as to investigate the recommended vaccine schedules for infants exposed to these drugs. A physiologically-based pharmacokinetic (PBPK) model of anti-TNF agents was built for adults and extrapolated to pregnant patients, fetuses, and infants. The PBPK models successfully predicted and verified the pharmacokinetics (PKs) of infliximab, adalimumab, and golimumab in pregnancy, fetuses, and infants. The predicted PK data were within two-fold of the observed data. The simulated results were used as timing advice. According to the dose of administration, the suggested timing of the last dosing for infliximab, adalimumab, and golimumab is successfully provided based on PBPK predictions. PBPK models indicated that, for infants, the advocated timing of vaccination is 12, 8, and 5 months after birth for infliximab, adalimumab, and golimumab, respectively. Our study illustrated that PBPK models can provide a valuable tool to predict the PKs of large macromolecules in pregnant women, fetuses, and infants, ultimately informing drug-treatment decisions for pregnancy and vaccination regimens for infants.

Characterization of pollen tube development in distant hybridization of Chinese cork oak (Quercus variabilis L.)

MAIN CONCLUSION

This work mainly found that the stigma and style of Q. variabilis did not completely lose the specific recognition towards heterologous pollen, a fact which is different from previous studies. Quercus is the foundation species in the Northern Hemisphere, with extreme prevalence for interspecific hybridization. It is not yet entirely understood whether or how the pollen tube-female tissue interaction contributes to the "extensive hybridization" in oaks. Pollen storage conditions correlate with distant hybridization. We conducted hybridization experiments with Q. variabilis as female and Q. variabilis and Q. mongolica as male parents. And the differences in pollen tube (PT) development between intra- and distant interspecific hybridization were studied by fluorescence microscopy and scanning electron microscopy (SEM). Our results showed that -20 °C allowed pollen of both species to maintain some viability. Both Q. variabilis and Q. mongolica pollen germinated profusely on the stigmas. SEM results indicated that in the intraspecific hybridization, Q. variabilis pollen started to germinate at 6 h after pollination (hap), PTs elongated significantly at 12 hap, and entered the stigma at 24 hap. By contrast, Q. mongolica pollen germinated at 15 hap, and the PTs entered the stigma at 27 hap. By fluorescence microscopical studies it was observed that some PTs of Q. variabilis gathered at the style-joining at 96 hap, unlike the Q. mongolica which reached the style junction at 144 hap. The above results indicate that the abundant germination of heterologous pollen (HP) on the stigma and the "Feeble specificity recognition" of the stigma and transmitting tract to HP may create opportunities for the "extensive hybridization" of oaks. This work provides a sexual developmental reference for clarifying the causes of Quercus "extensive hybridization".

Physiologically based pharmacokinetic model combined with reverse dose method to study the nephrotoxic tolerance dose of tacrolimus

Nephrotoxicity is the most common side effect that severely limits the clinical application of tacrolimus (TAC), an immunosuppressive agent used in kidney transplant patients. This study aimed to explore the tolerated dose of nephrotoxicity of TAC in individuals with different CYP3A5 genotypes and liver conditions. We established a human whole-body physiological pharmacokinetic (WB-PBPK) model and validated it using data from previous clinical studies. Following the injection of 1 mg/kg TAC into the tail veins of male rats, we developed a rat PBPK model utilizing the drug concentration-time curve obtained by LC-MS/MS. Next, we converted the established rat PBPK model into the human kidney PBPK model. To establish renal concentrations, the BMCL5 of the in vitro CCK-8 toxicity response curve (drug concentration range: 2-80 mol/L) was extrapolated. To further investigate the acceptable levels of nephrotoxicity for several distinct CYP3A5 genotypes and varied hepatic function populations, oral dosing regimens were extrapolated utilizing in vitro-in vivo extrapolation (IVIVE). The PBPK model indicated the tolerated doses of nephrotoxicity were 0.14-0.185 mg/kg (CYP3A5 expressors) and 0.13-0.155 mg/kg (CYP3A5 non-expressors) in normal healthy subjects and 0.07-0.09 mg/kg (CYP3A5 expressors) and 0.06-0.08 mg/kg (CYP3A5 non-expressors) in patients with mild hepatic insufficiency. Further, patients with moderate hepatic insufficiency tolerated doses of 0.045-0.06 mg/kg (CYP3A5 expressors) and 0.04-0.05 mg/kg (CYP3A5 non-expressors), while in patients with moderate hepatic insufficiency, doses of 0.028-0.04 mg/kg (CYP3A5 expressors) and 0.022-0.03 mg/kg (CYP3A5 non-expressors) were tolerated. Overall, our study highlights the combined usage of the PBPK model and the IVIVE approach as a valuable tool for predicting toxicity tolerated doses of a drug in a specific group.

Arthroscopic Autologous Coracoacromial Ligament Augment Technique for Particle Thickness of Rotator Cuff with at Least Two Years Follow-Up

OBJECTIVE

Patch technology has been the new technique in the treatment of partial thickness of the rotator cuff tear (PTRCTs) to address the limitation of traditional techniques. Compared with allogeneic patches and artificial materials, coracoacromial ligament is obviously closer to their own biology. The purpose of the study was to evaluate the functional and radiographic outcomes following arthroscopic autologous coracoacromial ligament augment technique for treatment of PTRCTs.

METHOD

This study included three female patients with PTRCTs who underwent arthroscopy operation in 2017 with an average age of 51 years (range from 50 to 52 years). The coracoacromial ligament implant was attached to the bursal side surface of the tendon. The clinical results were evaluated by American Shoulder and Elbow Surgeons (ASES) score, Simple Shoulder Test (SST), acromiohumeral distance (AHD) and muscle strength before and 12 months after operation. Magnetic resonance imaging (MRI) was performed 24 months after operation to assess the integrity of the anatomical structure of the original tear site.

RESULT

The average ASES score improved significantly from 57.3 preoperatively to 95.0 at 1-year follow-up. The strength improved significantly from grade 3 preoperatively to grade 5 at 1 year. Two of three patients underwent the MRI at 2-year follow-up. Radiographic released the complete healing of rotator cuff tear. No implant-related serious adverse events were reported.

CONCLUSION

The new technique of using autogenous coracoacromial ligament patch augment provides good clinical results on patients with PTRCTs.

Physiologically based pharmacokinetic modeling characterizes the drug-drug interaction between saxagliptin and rifampicin in patients with renal impairment

The aim of the present study is to develop physiologically based pharmacokinetic (PBPK) models for saxagliptin and its active metabolite, 5-hydroxy saxagliptin, and to predict the effect of co-administration of rifampicin, a strong inducer of cytochrome P450 (CYP) 3A4 enzymes, on the pharmacokinetics (PK) of saxagliptin and 5-hydroxy saxagliptin in patients with renal impairment. The PBPK models of saxagliptin and 5-hydroxy saxagliptin were developed and validated in GastroPlus^TM for healthy adults with or without rifampicin, and adults with varying renal functions. Then, the effect of renal impairment combined with drug-drug interaction (DDI) on saxagliptin and 5-hydroxy saxagliptin PK was investigated. The PBPK models successfully predicted the PK. For saxagliptin, the prediction suggests rifampin greatly weakened the effect of renal impairment on reducing clearance, and the inductive effect of rifampin on parent drug metabolism seems to be increased with an increase in the degree of renal impairment severity. For patients with the same degree of renal impairment, rifampicin would have a slightly synergistic effect on the increase of 5-hydroxy saxagliptin exposure compared with dosed alone. There is an unsignificant decline for the saxagliptin total active moiety exposure values in patients with the same degree of renal impairment. It seems that patients with renal impairment are unlikely to require additional dose adjustments when co-administered with rifampicin, compared with saxagliptin alone. Our study provides a reasonable approach to explore unknown DDI potential in renal impairment. This article is protected by copyright. All rights reserved.

Physiologically-Based Pharmacokinetic Modeling of Omalizumab to Predict the Pharmacokinetics and Pharmacodynamics in Pediatric Patients

Omalizumab is widely used in clinical practice; however, knowledge gaps in the dosage of omalizumab for children aged 2-6 years with moderate-to-severe persistent allergic asthma have been identified. The aim of this study was to explore dosing regimens for moderately-to-severely allergic pediatric patients aged 2-6 years. The physiologically-based pharmacokinetic (PBPK) model of omalizumab was developed and verified in adult patients, extrapolated to pediatric patients, and simulated for omalizumab by adding two observation chambers (free IgE and total IgE). The simulation results showed that the fold errors of the predicted and observed values of the area under the curve (AUC) and peak plasma concentration (C_max ) were between 0.5 and 2.0, and the average folding error and the absolute average folding error values for all concentration-time data points were 1.09 and 1.48, respectively. The PBPK model combined with pharmacokinetic/pharmacodynamic analysis of omalizumab demonstrated that both the model-derived dose and the original dose could control the average free IgE of 2-6-year-old children with moderate-to-severe allergic asthma below 25 ng/mL, and some of the model-derived doses were lower. This conclusion provides a basis for the selection of dosage in clinical practice reference.

Application of PBPK modeling in predicting maternal and fetal pharmacokinetics of levetiracetam during pregnancy

Levetiracetam is currently being used to treat epilepsy in pregnant women. The plasma concentration of levetiracetam drops sharply during pregnancy, and the inability of pregnant women to maintain therapeutic concentrations can lead to seizures. This study aimed to predict the changes in fetal and maternal plasma exposure to levetiracetam during pregnancy and provide advice on dose adjustment. The physiology-based pharmacokinetics (PBPK) model was developed using PK-Sim and Mobi software, and validated following comparison of the observed plasma concentration and pharmacokinetic parameters. The levetiracetam PBPK model for mother and the fetus at various stages of pregnancy was successfully established and verified. Predictions indicated that the area under the steady-state concentration-time curve for levetiracetam decreased to 83, 62, and 67% of baseline values in the first, second, and third trimesters, respectively. Based on PBPK predictions, the recommended dose of levetiracetam is 1.2, 1.6, and 1.5 times the baseline dose in the first, second, and third trimesters, respectively, not exceeding 4000 mg/day in the third trimester due to fetal safety. The levetiracetam PBPK model for pregnancy was successfully developed and validated, and could provide alternative levetiracetam dosing regimens across the stages of pregnancy.

Establishment and validation of a predictive nomogram for the risk of premalignant lesions in children with choledochal cyst

BACKGROUND

Choledochal cyst (CDC) increases the risk (2.5%-30%) of malignancy. Metaplasia and dysplasia have been recognized as premalignant lesions among CDCs. This study aimed to evaluate the risk factors of metaplasia and dysplasia in CDC children.

METHODS

Two hundred and ten CDC children who underwent cyst excision and Roux-en-Y hepaticojejunostomy at our institution between July 2020 and November 2021 were included and randomly divided into the training set and validation set. Univariate and multivariate logistic regression analysis were used to identify independent risk factors of premalignant lesions in the training set and build a predictive nomogram. The performance and discriminatory abilities of the nomogram were further assessed and validated in the validation set.

RESULTS

Of the 210 CDC children, 78 (37.1%) patients developed premalignant lesions. Age (OR, 1.011, 95%CI, 1.000-1.022, P = 0.046), symptoms duration (OR, 1.021, 95%CI, 1.001-1.042, P = 0.036), cyst diameter (OR, 1.737, 95%CI, 1.328-2.273, P < 0.001), recurrent attacks of biliary pancreatitis (OR, 3.653, 95%CI, 1.205-11.076, P = 0.022), and biliary operation history (OR, 5.860, 95%CI, 1.268-27.084, P = 0.024) were identified as independent risk factors. Based on these predictors, a predictive nomogram was generated. The AUC of the nomogram was 0.873 in the training set and 0.793 in the validation set, indicating that it was robust and well calibrated.

CONCLUSIONS

A novel nomogram to the individualized risk of premalignant lesions in CDC children was successfully built, on the basis of age, symptoms duration, cyst diameter, recurrent attacks of biliary pancreatitis, and biliary operation history. This nomogram, combined with the final pathological results, can help clinicians to develop more efficient follow-up strategies for the high-risk children with CDC.

Dietary Total Antioxidant Capacity and Cognitive Function in Older Adults in the United States: The NHANES 2011-2014

OBJECTIVES

Oxidative stress level takes part in the development of cognitive decline. However, the association between total antioxidant capacity (TAC) from diet and cognitive function is controversial. The aim of this study was to investigate the relationship between TAC and the cognitive function of older adults in the U.S.

DESIGN

A cross-sectional study.

SETTING

National Health and Nutrition Examination Surveys database.

PARTICIPANTS

2712 older adults aged over 60 years.

MEASUREMENTS

TAC was calculated from 8 antioxidative vitamins based on the reference values for vitamin C equivalent antioxidant capacity obtained from individuals' 24 h dietary recall. Four memory-related assessments were employed [Immediate Recall test (IRT), Delayed Recall test (DRT), Animal Fluency test (AFT), and Digit Symbol Substitution test (DSST)].

RESULTS

Among the 2712 participants, the median age was 68 years, and 50.4% were women. Participants in the group with higher TAC levels had relatively higher IRT, AFT and DSST scores (P=0.025, P=0.008, P<0.001, respectively). In adjusted weighted linear regression, log-transformed TAC was positively associated with AFT (β=1.10, 95%CI: 0.51, 1.70) and DSST (β=2.81, 95%CI: 1.16, 4.45). Compared with the first quartile, the participants in the second (Q2 vs. Q1, OR=0.66, 95%CI: 0.43,1.02) and fourth quartile (Q4 vs. Q1, OR=0.47, 95%CI:0.28, 0.78) of log-transformed TAC showed a decreased risk of impaired cognitive function (ICF) after adjusting for confounders. The dose-response analysis indicated a gradual descent in the risk of ICF as TAC increases. Diabetes mellitus (DM) mediated part of the effect of TAC on ICF. The relationship between TAC and ICF was more pronounced in subjects with DM (Q4 vs Q1, OR=0.36, 95%CI:0.17, 0.74).

CONCLUSION

Our findings support that higher dietary antioxidant potential was related to a decreased risk of cognitive dysfunction, particularly in the subjects with DM who may have oxidative injury. DM was one of the factors mediating the effect of TAC on ICF.

A nomogram model to predict prognosis of patients with hepatoblastoma

BACKGROUND

Hepatoblastomas (HBs) are malignant liver tumors that most commonly develop in pediatric patients. Microvascular invasion may be a prognosis factor for patients with HBs. This study aimed to construct a model to predict the survival outcome in HBs.

METHODS

We retrospectively analyzed the clinical data of 311 patients with HBs who underwent surgical resection at our institution between June 2014 and August 2021. First, patients were divided into two groups: those who had pathologic microvascular invasion (n = 146) and those who did not (n = 165). Propensity score-matched (PSM) analysis was carried out between the two groups. The preoperative parameters and overall survival (OS) rate were compared between the two groups. Second, all 311 patients were randomly divided into the training and validation cohort in a ratio of 4:1. A nomogram was created in the training cohort to visualize the prediction of OS. Moreover, the validation cohort was used for validation.

RESULTS

Multivariate analysis suggested that age, histology type, microvascular invasion, multifocality, distant metastasis, and macrovascular involvement are independent prognostic factors for HBs. The nomogram showed good predictive ability in the training and validation cohorts with a C-index of 0.878 (95% CI, 0.831-0.925) and 0.847 (95% CI, 0.757-0.937), respectively. The calibration curve indicated good agreement between the prediction and observation for one-, two-, and three-year OS probabilities.

CONCLUSION

By combining preoperative imaging results and other clinical data, we established a nomogram to predict OS probability for patients with HB, which could be a potential tool to guide personalized treatment.

Application of Physiologically Based Pharmacokinetic Modeling to Predict Maternal Pharmacokinetics and Fetal Exposure to Oxcarbazepine

Pregnancy is associated with physiological changes that may affect drug pharmacokinetics (PKs). The aim of this study was to establish a maternal-fetal physiologically based pharmacokinetic (PBPK) model of oxcarbazepine (OXC) and its active metabolite, 10,11-dihydro-10-hydroxy-carbazepine (MHD), to (1) assess differences in pregnancy, (2) predict changes in PK target parameters of these molecules following the current dosing regimen, (3) assess predicted concentrations of these molecules in the umbilical vein at delivery, and (4) compare different methods for estimating drug placental penetration. Predictions using the pregnancy PBPK model of OXC resulted in maternal concentrations within a 2-fold error, and extrapolation of the model to early-stage pregnancies indicated that changes in median PK parameters remained above target thresholds, requiring increased frequency of monitoring. The dosing simulation results suggested dose adjustment in the last two trimesters. We generally recommend that women administer ≥ 1.5× their baseline dose of OXC during their second and third trimesters. Test methods for predicting placental transfer showed varying performance, with the in vitro method showing the highest predictive accuracy. Exposure to MHD in maternal and fetal venous blood was similar. Overall, the above-mentioned models can enhance understanding of the maternal-fetal PK behavior of drugs, ultimately informing drug-treatment decisions for pregnant women and their fetuses.

Analysis of risk factors for angiolymphatic invasion and establishment of a predictive nomogram for hepatoblastomas

BACKGROUND

Hepatoblastomas (HBs)are malignant liver tumors that most commonly develop in pediatric patients. Although lymph node metastasis is rare in HBs, angiolymphatic invasion (ALI) is a risk factor affecting the prognosis of HBs. This study aimed to evaluate the risk factors for angiolymphatic invasion in HBs.

METHODS

We retrospectively analyzed the clinical data of 165 patients with HBs who underwent surgical resection at our institution between March 2016 and May 2021 and established binary logistic regression models to predict risk factors for ALI. The R software was used to construct the nomogram.

RESULTS

For the regression model based on the Children's Hepatic Tumors International Collaboration-Hepatoblastoma Stratification (CHIC-HS) system, tumor diameter, tumor response to neoadjuvant chemotherapy (NACT), and CHIC-HS were identified as independent risk factors for angiolymphatic invasion. For the regression model based on the pretreatment extent of the tumor (PRETEXT) stages with annotation factors, tumor diameter, multifocality, macrovascular involvement, tumor response to NACT, and PRETEXT stages were identified as independent risk factors for angiolymphatic invasion.

CONCLUSIONS

Using the CHIC-HS system/PRETEXT stages with annotation factors, tumor diameter and tumor response to NACT were identified as independent risk factors for angiolymphatic invasion. The distance between the tumor and portal vein was negatively correlated with the occurrence of multifocal tumors.

LEVEL OF EVIDENCE

Level III.

Effects of postoperative adjuvant steroid therapy on the outcomes of biliary atresia: A systematic review and updated meta-analysis

Background: Postoperative adjuvant steroid therapy is regarded as the conventional treatment for patients with biliary atresia (BA) who have undergone Kasai portoenterostomy (KP). However, whether the steroid therapy can improve BA outcomes is controversial. This meta-analysis aimed to evaluate the effects of adjuvant steroid therapy on the surgical prognosis of BA.

Methods: We searched related studies published in PubMed, Embase, Web of Science, Cochrane, and the Chinese National Knowledge Infrastructure database up to May 2022. Data on the effect of steroid use on the clinical prognosis of the patients, including the jaundice clearance rate (JCR), native liver survival rate (NLSR) at 6, 12, and 24 months after KP, and the incidence of cholangitis, were extracted. Subgroup analyses based on age at KP, administration method, initial dosage, and steroid type were conducted. Statistical analysis was conducted using Stata/SE 12.0.

Results: Eleven articles (a total of 1,032 patients) were included in the present meta-analysis. The results demonstrated that postoperative adjuvant steroid therapy improved JCR at the 6/12/24-month follow-up (RR: 1.35, 95% CI: 1.18–1.55, p < 0.001; RR:1.49, 95% CI, 1.12–1.99, p = 0.006; RR: 1.41, 95% CI: 1.14–1.75, p = 0.002) and improved NLSR at the 24-month follow-up (RR: 1.31, 95% CI: 1.03–1.68, p = 0.028). However, steroids could not significantly improve NLSR at the 6/12-month follow-up (RR: 1.06; 95% CI: 0.98–1.15; p = 0.17; RR: 1.22; 95% CI: 0.97–1.54; p = 0.095), and might not decrease the incidence of postoperative cholangitis (RR: 0.78, 95% CI: 0.60–1.01, p = 0.058). Furthermore, subgroup analyses confirmed that three variables (age at KP, administration method, and initial dosage) could affect the efficacy of steroids in BA patients.

Conclusion: Postoperative adjuvant steroid therapy can significantly improve bile flow. The superiority of steroid therapy was more remarkable in patients aged ≤70 days at KP than in those aged >70 days. Additionally, intravenous followed by oral steroid administration method and medium initial dosage seemed to have the more reliable efficiency on bile flow. And patients treated by steroid had better long-term (24-month) native liver survival, but there is no significant effect on short-term native liver survival and postoperative cholangitis. Further studies are warranted.

Impact of early Kasai portoenterostomy on short-term outcomes of biliary atresia: A systematic review and meta-analysis

Background

Good outcomes of biliary atresia (BA) are conventionally achieved after early Kasai portoenterostomy (KP). However, in some recent pieces of literature, there are discrepancies in the influence of age in Kasai procedure on postoperative short-term prognosis. This meta-analysis aims to evaluate the effects of earlier KP on short-term surgical prognosis of BA and clarify these discrepancies in recent studies.

Methods

To identify related studies, PubMed, Embase, Web of Science, Cochrane, and the Chinese National Knowledge Infrastructure database were searched up to March 2022. Data for the impact of age at KP on clinical prognosis were extracted, including jaundice clearance rate (JCR) and native liver survival rate (NLSR).

Results

A total of 14 articles were included in the present study, which involve a total of 3,276 patients with BA who underwent Kasai procedure. Compared with patients older than 91 days of age, patients 90 days of age or younger exhibited significantly better JCR [odds ratio (OR), 3.05; 95% confidence interval (CI), 2.23–4.17; P < .001] and a more favorable NLSR (OR, 1.72; 95% CI, 1.37–2.15; P < .001). The NLSR of patients younger than 60 days of age was significantly higher than those of patients from 61 to 90 days of age (OR, 1.41; 95% CI, 1.18–1.68; P < .001). There was no significant difference in JCRs between patients aged 60 days of age or younger and those aged 61–90 days of age (OR, 1.31; 95% CI, 0.95–1.81; P = 0.10). Among patients 30 days of age or younger, 31–45 days of age, and 46–60 days of age, there were also no significant differences in JCR.

Conclusion

A significantly better short-term JCR and NLSRs were achieved among patients with BA treated using a KP procedure at ≤90 days of age compared with those treated at >90 days of age. There was no further improvement in the short-term JCR when the procedure was performed at ≤60 days compared with those treated at 61–90 days of age. However, treatment at ≤60 days of age was associated with a significant improvement in NLSR. Therefore, the timing of KP does exert an important effect on short-term clinical outcomes of patients with BA.

Physiologically based pharmacokinetic modeling of daptomycin dose optimization in pediatric patients with renal impairment

Background and Objective: Daptomycin is used to treat Gram-positive infections in adults and children and its dosing varies among different age groups. We focused on the pharmacokinetics of daptomycin in children with renal impairment, which has not been evaluated.

Methods: A physiologically based pharmacokinetic (PBPK) model of daptomycin was established and validated to simulate its disposition in healthy populations and adults with renal impairment, along with a daptomycin exposure simulated in pediatric patients with renal impairment.

Results: The simulated PBPK modeling results for various regimens of intravenously administered daptomycin were consistent with observed data according to the fold error below the threshold of 2. The Cmax and AUC of daptomycin did not differ significantly between children with mild-to-moderate renal impairment and healthy children. The AUC increased by an average of 1.55-fold and 1.85-fold in severe renal impairment and end-stage renal disease, respectively. The changes were more significant in younger children and could reach a more than 2-fold change. This scenario necessitates further daptomycin dose adjustments.

Conclusion: Dose adjustments take into account the efficacy and safety of the drug; however, the steady-state Cmin of daptomycin may be above 24.3 mg/L in a few instances. We recommend monitoring creatine phosphokinase more than once a week when using daptomycin in children with renal impairment.

Ceftaroline Dosage Optimized for Pediatric Patients With Renal Impairment Using Physiologically Based Pharmacokinetic Modeling

Ceftaroline fosamil is a fifth-generation cephalosporin approved as a treatment for adults and children with community-acquired bacterial pneumonia and acute bacterial skin and skin structure infections. However, its pharmacokinetics have not been fully evaluated in children with renal impairment. This study aimed to propose proper ceftaroline dosages optimized for the renally impaired pediatric population using physiologically based pharmacokinetic (PBPK) modeling. A PBPK model of ceftaroline was established and verified to simulate its disposition in the healthy population and renally impaired adults and to predict the exposure in renally impaired pediatric patients. Consistency was confirmed between simulated and observed data after intravenous administration of various ceftaroline regimens; fold errors were within the 2-fold error range. Among 6-year-old children, healthy subjects had 1.5-fold, 2-fold, and 2.6-fold lower areas under the plasma concentration-time curve (AUCs) than the moderate, severe, and end-stage renally impaired patient groups, respectively; among 1-year-old children, healthy subjects had 1.5-fold, 2.1-fold, and 2.5-fold lower AUCs than the respective renally impaired patient groups; among 1-month-old children, healthy subjects had 1.5-fold, 1.8-fold, and 2.2-fold lower AUCs than the respective renally impaired patient groups. The proposed dosage should be adjusted to 8, 6, and 5 mg/kg every 8 hours for patients aged ≥2 years to <18 years (≤33 kg) with moderate, severe, and end-stage renal impairment, respectively; 5, 4, and 3 mg/kg every 8 hours for patients aged 2 months to <2 years with moderate, severe, and end-stage renal impairment, respectively; 4, 3.5, and 2.5 mg/kg every 8 hours for patients 0 to <2 months of age with moderate, severe, and end-stage renal impairment, respectively. Furthermore, pharmacodynamic investigations demonstrated that adequate antimicrobial effects were attained at the proposed doses in 3 age groups. Hence, our PBPK model can be an effective tool to support ceftaroline dosage proposals for renally impaired pediatric patients.

Structure of a mammalian sperm cation channel complex

The cation channel of sperm (CatSper) is essential for sperm motility and fertility^1,2. CatSper comprises the pore-forming proteins CATSPER1-4 and multiple auxiliary subunits, including CATSPERβ, γ, δ, ε, ζ, and EFCAB9^1,3-9. Here we report the cryo-electron microscopy (cryo-EM) structure of the CatSper complex isolated from mouse sperm. In the extracellular view, CATSPER1-4 conform to the conventional domain-swapped voltage-gated ion channel fold¹⁰, following a counterclockwise arrangement. The auxiliary subunits CATSPERβ, γ, δ and ε-each of which contains a single transmembrane segment and a large extracellular domain-constitute a pavilion-like structure that stabilizes the entire complex through interactions with CATSPER4, 1, 3 and 2, respectively. Our EM map reveals several previously uncharacterized components, exemplified by the organic anion transporter SLCO6C1. We name this channel-transporter ultracomplex the CatSpermasome. The assembly and organization details of the CatSpermasome presented here lay the foundation for the development of CatSpermasome-related treatments for male infertility and non-hormonal contraceptives.

Chinese Version of the Baylor Profound Mental Status Examination: A Brief Staging Measure for Patients with Severe Alzheimer's Disease

BACKGROUND

A specialized instrument for assessing the cognition of patients with severe Alzheimer's disease (AD) is needed in China.

OBJECTIVES

To validate the Chinese version of the Baylor Profound Mental Status Examination (BPMSE-Ch).

DESIGN

The BPMSE is a simplified scale which has proved to be a reliable and valid tool for evaluating patients with moderate to severe AD, it is worthwhile to extend the use of it to Chinese patients with AD.

SETTING

Patients were assessed from the Memory Clinic Outpatient.

PARTICIPANTS

All participants were diagnosed as having probable AD by assessment.

MEASUREMENTS

The BPMSE was translated into Chinese and back translated. The BPMSE-Ch was administered to 102 AD patients with a Mini-Mental State Examination (MMSE) score below 17. We assessed the internal consistency, reliability, and construct validity between the BPMSE-Ch and MMSE, Severe Impairment Battery (SIB), Global Deterioration Scale (GDS-1), Geriatric Depression Scale(GDS-2), Instrumental Activities of Daily Living (IADL), Physical Self-Maintenance Scale (PSMS), Neuropsychiatric Inventory (NPI) and Clinical Dementia Rating (CDR).

RESULTS

The BPMSE-Ch showed good internal consistency (α = 0.87); inter-rater and test-retest reliability were both excellent, ranging from 0.91 to 0.99. The construct validity of the measure was also supported by significant correlations with MMSE, SIB. Moreover, as expected, the BMPSE-Ch had a lower floor effect than the MMSE, but a ceiling effect existed for patients with MMSE scores above 11.

CONCLUSIONS

The BPMSE-Ch is a reliable and valid tool for evaluating cognitive function in Chinese patients with severe AD.

Dosage Adjustment for Ceftazidime in Pediatric Patients With Renal Impairment Using Physiologically Based Pharmacokinetic Modeling

Physiologically based pharmacokinetic (PBPK) modeling has unique advantages in investigating the pharmacokinetics of drugs in special populations. Our aim is to design optimized dosing regimens for ceftazidime in renally-impaired pediatric patients using PBPK modeling. Models for healthy and renally-impaired adults were developed, verified, and adapted for children to predict ceftazidime exposure in pediatric patients with varying degrees of renal impairment, capturing age- and weight-related pharmacokinetic changes. We derived a dosage-adjusted regimen for renally-impaired children based on pharmacokinetic data and evaluated the pharmacodynamics of ceftazidime. The PBPK models adequately predicted ceftazidime exposures in populations after single- and multi-dose administrations, with fold error values within 1.1 between simulated and observed data. In moderate, severe, and end-stage renally-impaired pediatric patients, the areas under the plasma concentration-time curves (AUCs) were 1.87-fold, 3.56-fold, and 6.19-fold higher, respectively, than in healthy children when treated with the same dose of 50 mg/kg. Pharmacodynamic verification indicated that the recommended doses of 28, 15, and 8 mg/kg administered three times daily (every 8 h) to pediatric patients with moderate, severe, and end-stage renal disease, respectively, were sufficient to attain the target of maintaining the free plasma concentration at or above minimum inhibitory concentration (MIC) during 70% of the dosing interval (70% fT > MIC: nearly 100% target attainment for susceptible MIC of 4 mg/L and >70% for intermediate MIC of 8 mg/L). Our PBPK model can be an effective tool to support dosing recommendations in pediatric patients with different degrees of renal impairment.

Structure of the human sodium leak channel NALCN in complex with FAM155A

NALCN, a sodium leak channel expressed mainly in the central nervous system, is responsible for the resting Na+ permeability that controls neuronal excitability. Dysfunctions of the NALCN channelosome, NALCN with several auxiliary subunits, are associated with a variety of human diseases. Here, we report the cryo-EM structure of human NALCN in complex with FAM155A at an overall resolution of 3.1 angstroms. FAM155A forms extensive interactions with the extracellular loops of NALCN that may help stabilize NALCN in the membrane. A Na+ ion-binding site, reminiscent of a Ca2+ binding site in Cav channels, is identified in the unique EEKE selectivity filter. Despite its 'leaky' nature, the channel is closed and the intracellular gate is sealed by S6I, II-III linker and III-IV linker. Our study establishes the molecular basis of Na+ permeation and voltage sensitivity, and provides important clues to the mechanistic understanding of NALCN regulation and NALCN channelosome-related diseases.

A Physiologically Based Pharmacokinetic Model of Ertapenem in Pediatric Patients With Renal Impairment

Ertapenem is a widely used antibiotic; however, its pharmacokinetics has not been fully evaluated in children with renal impairment. A physiologically based pharmacokinetic (PBPK) model of ertapenem was established and validated to simulate its disposition in the healthy population and adults with renal impairment, as well as to predict the exposure in pediatric patients with renal impairment. The simulated PBPK modeling results and the observed data of ertapenem after intravenous administration of various regimens were consistent according to the fold error values of less than 2. Furthermore, %T > MIC of ertapenem was evaluated using the PBPK model. The C_max was not significantly changed in pediatric patients with renal impairment compared to healthy children. However, the AUC was 1.42-fold, 1.84-fold, 2.37-fold, and 3.52-fold higher in mild, moderate, severe renal impairment, and end-stage renal disease, respectively, than that in healthy children and the doses of ertapenem were reduced to 13 mg/kg b.i.d, 9 mg/kg b.i.d, 6 mg/kg b.i.d, and 5 mg/kg b.i.d, respectively. The probability of achieving 40%T > MIC (MIC ≤ 4 μg/mL) was nearly 100% throughout the recommended dosing interval. In conclusion, our model can be used as a tool to generate better predictions for the most effective ertapenem dosing in pediatric patients.

Simulation of the Pharmacokinetics of Oseltamivir and Its Active Metabolite in Normal Populations and Patients with Hepatic Cirrhosis Using Physiologically Based Pharmacokinetic Modeling

Oseltamivir is a neuraminidase inhibitor widely used to treat and prevent influenza A and B infections, although its safety and pharmacokinetics have not been evaluated in patients with severe hepatic impairment. A physiologically based pharmacokinetic (PBPK) model of the prodrug oseltamivir and its active metabolite, oseltamivir carboxylate (OC), was established and validated to simulate their disposition in adults and predict the exposure in patients with Child-Pugh C cirrhosis (CP-C). The simulated results from PBPK modeling and the observed data after oral administration of various oseltamivir regimens were consistent according to the fold error values of less than 2. Furthermore, the clinical observations published in the literature were comparable with our pharmacokinetic predictions. In patients with CP-C, the oseltamivir C_max was approximately 2-fold increased, and its AUC was approximately 6-fold higher compared with those in normal subjects. In contrast, the AUC of OC in CP-C patients did not differ significantly from that in normal subjects, whereas its C_max was reduced by approximately 30% in the patients. Examination of drug exposure in different health conditions indicated that the oseltamivir exposure was significantly increased in conditions with elevated cirrhosis severity, which might be associated with a higher risk of adverse drug effects, e.g., neuropsychiatric adverse events (NPAEs). In conclusion, the pharmacokinetics of oseltamivir and OC were correctly predicted by PBPK modeling. The model further predicted that the pharmacokinetics of oseltamivir might be altered in liver cirrhosis, depending on the degree of severity.

Prediction of Ticagrelor and its Active Metabolite in Liver Cirrhosis Populations Using a Physiologically Based Pharmacokinetic Model Involving Pharmacodynamics

Ticagrelor, a P2Y₁₂ receptor antagonist, has been highly recommended for use in acute coronary syndrome. The major active metabolite (AM) is similar to the parent drug, which exhibits antiplatelet activity. The inhibition of platelet aggregation (IPA) is used as an assay to demonstrate the anticoagulant efficacy of ticagrelor. In this study, we developed a physiologically based pharmacokinetic (PBPK) model to predict the pharmacokinetics of ticagrelor and its AM and combined this model with a pharmacodynamics model to reflect potential pharmacodynamic alterations in liver cirrhosis populations. The simulated results obtained using the PBPK model were validated by fold error values, which were all smaller than 2. Comparisons of exposure in different classifications of liver cirrhosis indicated that exposure to ticagrelor increased significantly with an increase in the degree of cirrhosis severity, whereas exposure to AM was decreased. The total concentration of ticagrelor and AM was related to the IPA included in the Sigmoid E_max model. The PBPK model of ticagrelor and AM could predict the pharmacokinetics of all populations, and a combination of PD models was used to extrapolate for predicting unknown scenarios. Liver cirrhosis may result in prolonged IPA, depending on the severity degree of this disease. The combined PBPK model including IPA can reveal changes in pharmacokinetics and pharmacodynamics in populations affected by liver cirrhosis and indicate the risk potential.

A Retrospective Analysis on 1330 Adverse Event Reports of Qingkailing in China: Further Perception of Its Risks and Rational Use

Qingkailing (QKL) is a modern preparation exploited according to the traditional Chinese medicine theory. It becomes the second leading cause of adverse drug events (ADEs) in all traditional Chinese medicine injections. The safety evaluation and rational use of QKL are of special importance. This retrospective study used data from Adverse Drug Reaction Monitoring Center of Hubei Province in China from January 2012 to December 2014. ADE cases induced by QKL were collected and analyzed according to patients' demographics, characteristics of drugs involved, characteristics of ADEs, causality, and outcomes. A total of 1330 qualified ADEs were included. Most ADEs occurred within 30 min after administration and the 0-10 years old age group had the highest number of ADEs. The common ADEs included anaphylactic reaction, dyspnea and nausea. Serious reactions accounted for 5.19%. Combination with cephalosporin (74/146, 50.69%) caused more ADEs than other drugs did. Serious attention should be paid when QKL is used for children, and combination with cephalosporin should be avoided.

[Chorionic villus cell culture and karyotype analysis in 1 983 cases of spontaneous miscarriage]

Objective: To investigate the relationship between spontaneous miscarriage and embryonic chromosome abnormalities, and to evaluate the clinical application of karyotype analysis by chorionic villus cell culture. Methods: The chorionic villus karyotype of 1 983 cases of miscarriage from January 2010 to July 2016 in Guangzhou Women and Children's Mecical Center were analyzed retrospectively. The miscarried chorionic villi were obtained by curettage under sterilized condition. The chromosome specimens were prepared after chorionic villus cell culture. Karyotype analysis was performed by G-banding technique. Results: In the 1 983 samples, successful karyotype analysis was performed in 1 770 cases, with the successful rate of 89.98%. Chromosomal abnormalities were found in 1 038 cases (58.64%, 1 038/1 770). Chromosomal structural abnormalities were found in 37 cases. The numeral abnormalities were more common than structural abnormalities, and most of the numeral abnormalities were aneupoidies. In turn, they were trisomy 16, 45,X, trisomy 22, trisomy 2, trisomy 21, trisomy 15. The most common structural abnormality was balanced translocation, including Robersonian translocation. Female embryoes accounted for 61.02% (1 080/1 770) miscarriages and for 57.4%(596/1 770) of chromosomal abnormalities, while male embroyes acoounted for 61.02% (1 080/1 770) , 57.4% (596/1 770) respectively. The proportion of female embryoes was higher than male embryoes. The median age of the patients was 30 years old (16-46 years old) . As the maternal age increased, the proportion chromosomal abnormalities increased. The incidence of chromosomal abnormalities in the advanced age group (≥35 years) was 68.38% (240/351) , which was significantly higher than that in the younger group (56.24%, 798/1 419; χ(2)=17.10, P<0.01). Conclusions: Embryonic chromosomal abnormalities are the most common cause of early spontaneous miscarriage. The abnormalities centralize in some karyotypes. There is certain relationship between maternal age and the incidence of miscarriage, as well as the embryonic gender. Chorionic villus cell culture and karyotype analysis are helpful in finding the cause of miscarriage and counsel the patients.

Crystal structure of the bacterial acetate transporter SatP reveals that it forms a hexameric channel

Acetate is found ubiquitously in the natural environment and can be used as an exogenous carbon source by bacteria, fungi, and mammalian cells. A representative member of the acetate uptake transporter (AceTr) family named SatP (also yaaH) has been preliminarily identified as a succinate-acetate/proton symporter in Escherichia coli However, the molecular mechanism of acetate uptake by SatP still remains elusive. Here, we report the crystal structure of SatP from E. coli at 2.8 Å resolution, determined with a molecular replacement approach using a previously developed predicted model algorithm, which revealed a hexameric UreI-like channel structure. Structural analysis identified six transmembrane (TM) helices surrounding the central channel pore in each protomer and three conserved hydrophobic residues, FLY, located in the middle of the TM region for pore constriction. According to single-channel conductance recordings, performed with purified SatP reconstituted into lipid bilayer, three conserved polar residues in the TM1 facing to the periplasmic side are closely associated with acetate translocation activity. These analyses provide critical insights into the mechanism of acetate translocation in bacteria and a first glimpse of a structure of an AceTr family transporter.

[Corneal astigmatism among 2 085 age-related cataract patients before surgery]

Objective: To investigate the characteristics and distribution of corneal astigmatism before surgery among age-related cataract patients in the Hubei area. Methods: Retrospective study. From January 1, 2012 to July 31, 2016, IOL Master measurements of all qualified cataract surgery candidates were retrospectively collected. Descriptive statistical analysis was used to assess the degree, distribution and type of corneal astigmatism. Kolmogorov-Smirnov (K-S) test was used to evaluate the normal distribution of variables. One-way analysis of variance and Kruskal-Wallis test were applied for the comparison of variance for normally and non-normally distributed quantitative data among different age groups. Spearman's rank test was used to assess the relationship between age and corneal astigmatism. Results: The mean age of the 2 085 patients (3 586 eyes) involved was (73.1±9.43) years old, with more women (58.3%) than men. The mean value of corneal curvature was 44.33 D (95%CI: 44.28-44.39), and the mean corneal astigmatism was 1.06 D (range, 0.05 D to 6.74 D). K-S test indicated the distribution of corneal curvature was normal (P=0.18), while corneal astigmatism did not obey the normal distribution (P<0.01). Corneal astigmatism was between 0.25 D and 1.25 D in 67.7% of the eyes, >1.25 D in 29.7%, and<0.25 D in 4.2%. Corneal astigmatism degree increased with the age increase (P<0.01). There was no statistical difference in corneal astigmatism between women and men (P=0.075). However, women had steeper corneal curvatures than men with statistical difference (P<0.01). Corneal astigmatism with the rule was observed in 29.0% of the eyes, while astigmatism against the rule was found in 53.0%. And astigmatism against the rule increased with age. Conclusion: Corneal astigmatism mostly distributes between 0.25 D and 1.25 D in age-related cataract patients who lived in Hubei. Corneal astigmatism degree increased with age, and the dominant type was astigmatism against the rule. There was no difference in astigmatism between men and women patients aged 50 years and above, but in 70- to 79-year-old patients, women had a higher astigmatism degree than men. The corneal curvature of women was steeper than men in general and in each age group. (Chin J Ophthalmol, 2017, 53: 522-527).

Molecular determinants for the thermodynamic and functional divergence of uniporter GLUT1 and proton symporter XylE

GLUT1 facilitates the down-gradient translocation of D-glucose across cell membrane in mammals. XylE, an Escherichia coli homolog of GLUT1, utilizes proton gradient as an energy source to drive uphill D-xylose transport. Previous studies of XylE and GLUT1 suggest that the variation between an acidic residue (Asp27 in XylE) and a neutral one (Asn29 in GLUT1) is a key element for their mechanistic divergence. In this work, we combined computational and biochemical approaches to investigate the mechanism of proton coupling by XylE and the functional divergence between GLUT1 and XylE. Using molecular dynamics simulations, we evaluated the free energy profiles of the transition between inward- and outward-facing conformations for the apo proteins. Our results revealed the correlation between the protonation state and conformational preference in XylE, which is supported by the crystal structures. In addition, our simulations suggested a thermodynamic difference between XylE and GLUT1 that cannot be explained by the single residue variation at the protonation site. To understand the molecular basis, we applied Bayesian network models to analyze the alteration in the architecture of the hydrogen bond networks during conformational transition. The models and subsequent experimental validation suggest that multiple residue substitutions are required to produce the thermodynamic and functional distinction between XylE and GLUT1. Despite the lack of simulation studies with substrates, these computational and biochemical characterizations provide unprecedented insight into the mechanistic difference between proton symporters and uniporters.

We seek to address one intriguing question, the mechanistic distinction between active proton-coupled symporters and passive uniporters that are related in evolution. Proton-coupled symporters harness the transmembrane proton gradient to drive the substrate transport, while uniporters can only facilitate the passive substrate translocation. In this work, we focus on two sugar transporters GLUT1 and XylE, which belong to symporters and uniporters respectively but have high sequence similarity. We first applied molecular dynamics simulations to characterize the thermodynamic behaviors of apo GLUT1 and XylE, which are supposed to provide prominent details of mechanisms. From the identified difference in thermodynamics, we concluded that neutralizing protonation site in XylE is insufficient for its conversion to GLUT1 analog. To pinpoint extra elements contributing to their evolutionary divergence, we developed a novel network modeling scheme based on Bayesian network which shows impressive predictive power on residue mutations. Our models suggested the detailed mechanism of proton coupling in XylE and molecular basis of symporter/uniporter discrepancy. Furthermore, the modeling scheme could help to guide the design of biomolecules for desired functions.

Short-term and long-term effect of diaphragm biofeedback training in gastroesophageal reflux disease: an open-label, pilot, randomized trial

This study investigated the effectiveness of diaphragm biofeedback training (DBT) for patients with gastroesophageal reflux disease (GERD). A total of 40 patients with GERD treated at the Peking Union Medical College Hospital between September 2004 and July 2006 were randomized to receive DBT and rabeprazole proton pump inhibitor (PPI) or rabeprazole alone. The DBT + rabeprazole group received DBT during the 8-week initial treatment; the rabeprazole group did not. During the 6-month follow up, all patients took acid suppression according to their reflux symptoms, and the patients in the DBT + rabeprazole group were required to continue DBT. The primary outcome (used for power analysis) was the amount of acid suppression used at 6 months. Secondary outcomes were reflux symptoms, health-related quality of life (HRQL), and esophageal motility differences after the 8-week treatment compared with baseline. Acid suppression usage significantly decreased in the DBT + rabeprazole group compared with the rabeprazole group at 6 months (P < 0.05). At 8 weeks, reflux symptoms and GERD-HRQL were significantly improved in both groups (P < 0.05), without difference between them. Crural diaphragm tension (CDT) and gastroesophageal junction pressure (GEJP) significantly increased in the DBT + rabeprazole group (P < 0.05), but without change in lower esophageal sphincter (LES) pressure. There was no significant change in CDT, GEJP, and LES pressure compared with baseline in the rabeprazole group. In conclusion, long-term DBT could reduce acid suppression usage by enhancing the anti-reflux barrier, providing a non-pharmacological maintenance therapy and reducing medical costs for patients with GERD.

Protonation of Glu(135) Facilitates the Outward-to-Inward Structural Transition of Fucose Transporter

Major facilitator superfamily (MFS) transporters typically need to alternatingly sample the outward-facing and inward-facing conformations, in order to transport the substrate across membrane. To understand the mechanism, in this work, we focused on one MFS member, the L-fucose/H(+) symporter (FucP), whose crystal structure exhibits an outward-open conformation. Previous experiments imply several residues critical to the substrate/proton binding and structural transition of FucP, among which Glu(135), located in the periplasm-accessible vestibule, is supposed as being involved in both proton translocation and conformational change of the protein. Here, the structural transition of FucP in presence of substrate was investigated using molecular-dynamics simulations. By combining the equilibrium and accelerated simulations as well as thermodynamic calculations, not only was the large-scale conformational change from the outward-facing to inward-facing state directly observed, but also the free energy change during the structural transition was calculated. The simulations confirm the critical role of Glu(135), whose protonation facilitates the outward-to-inward structural transition both by energetically favoring the inward-facing conformation in thermodynamics and by reducing the free energy barrier along the reaction pathway in kinetics. Our results may help the mechanistic studies of both FucP and other MFS transporters.

PROTEIN STRUCTURE. Crystal structure of a mycobacterial Insig homolog provides insight into how these sensors monitor sterol levels

Insulin-induced gene 1 (Insig-1) and Insig-2 are endoplasmic reticulum membrane-embedded sterol sensors that regulate the cellular accumulation of sterols. Despite their physiological importance, the structural information on Insigs remains limited. Here we report the high-resolution structures of MvINS, an Insig homolog from Mycobacterium vanbaalenii. MvINS exists as a homotrimer. Each protomer comprises six transmembrane segments (TMs), with TM3 and TM4 contributing to homotrimerization. The six TMs enclose a V-shaped cavity that can accommodate a diacylglycerol molecule. A homology-based structural model of human Insig-2, together with biochemical characterizations, suggest that the central cavity of Insig-2 accommodates 25-hydroxycholesterol, whereas TM3 and TM4 engage in Scap binding. These analyses provide an important framework for further functional and mechanistic understanding of Insig proteins and the sterol regulatory element-binding protein pathway.

Prediction of conformational B-cell epitopes

Conformational B-cell epitopes play an important role in the epitope-based vaccine design. The increase of available data promotes the development of computational methods. Compared with the wet experiments, the computational methods are faster and more economic. In the past few years, a number of computational methods (especially the machine learning-based methods) have been developed to predict the conformational B-cell epitopes. In this chapter, we introduce important data resources and computational methods, which are publicly available. Moreover, we introduce our ensemble learning-based method that can predict the conformational epitopes from sequences. These promising methods may assist immunologists in identifying potential vaccine candidates.

Exploring the pH-dependent substrate transport mechanism of FocA using molecular dynamics simulation

FocA belongs to the formate-nitrate transporter family and plays an essential role in the export and uptake of formate in organisms. According to the available crystal structures, the N-terminal residues of FocA are structurally featureless at physiological conditions but at reduced pH form helices to harbor the cytoplasmic entrance of the substrate permeation pathway, which apparently explains the cessation of electrical signal observed in electrophysiological experiments. In this work, we found by structural analysis and molecular dynamics simulations that those N-terminal helices cannot effectively preclude the substrate permeation. Equilibrium simulations and thermodynamic calculations suggest that FocA is permeable to both formate and formic acid, the latter of which is transparent to electrophysiological studies as an electrically neutral species. Hence, the cease of electrical current at acidic pH may be caused by the change of the transported substrate from formate to formic acid. In addition, the mechanism of formate export at physiological pH is discussed.

Mesenchymal stromal cells infusions improve refractory chronic graft versus host disease through an increase of CD5+ regulatory B cells producing interleukin 10

Refractory chronic graft-versus-host disease (cGVHD) is a significant complication resulting from allogeneic hematopoietic stem cell transplantation (HSCT). Mesenchymal stromal cells (MSCs) have shown promise for treating refractory cGVHD, but the favorable effects of MSCs therapy in cGVHD are complex and not fully understood. In this prospective clinical study, 20 of 23 cGVHD patients had a complete response or partial response in a 12-month follow-up study. The most marked improvements in cGVHD symptoms were observed in the skin, oral mucosa and liver. Clinical improvement was accompanied by a significantly increased number of interleukin (IL)-10-producing CD5+ B cells. Importantly, CD5+ B cells from cGVHD patients showed increased IL-10 expression after MSCs treatment, which was associated with reduced inflammatory cytokine production by T cells. Mechanistically, MSCs could promote the survival and proliferation of CD5+ regulatory B cells (Bregs), and indoleamine 2, 3-dioxygenase partially participates in the MSC-mediated effects on Breg cells. Thus, CD5+ Breg cells may have an important role in the process of MSC-induced amelioration of refractory cGVHD and may provide new clues to reveal novel mechanisms of action for MSCs.

Treatment of obesity by endoscopic gastric intramural injection of botulinum toxin A: a randomized clinical trial

BACKGROUND/AIMS

Botulinum toxin A (BTX-A) is an inhibitor of muscular contractions in both striated and smooth muscle. The purpose of this study was to observe the safety and efficacy of endoscopic injections of BTX-A into the gastric wall in obese patients.

METHODOLOGY

Twenty obese patients (BMI >28 kg/m2) were randomized into two groups: Group 1 (200 U BTX-A) and Group 2 (300 U BTX-A). For each patient, 20 puncture sites were selected into the gastric wall. Body weights and BMIs were recorded and gastric emptying times were determined before treatment and 1, 4 and 12 weeks after treatment. Blood samples for cholesterol, triglycerides, insulin, leptin, motilin, peptide tyrosine (PYY) and ghrelin levels were obtained before treatment and 1, 4 and 12 weeks after treatment.

RESULTS

Nineteen patients completed the follow-up. Both groups showed significant body weight and BMI decrease (p<0.05) with decreased TG levels. The gastric emptying times were longer than those before treatment in both groups, especially at the 1-week point (p<0.05). A significant decrease in fasting ghrelin levels in all 19 obese patients was found after BTX-A administration 4 weeks later, and PYY levels in all 19 patients decreased, especially at the 12-week point. No severe complications were observed.

CONCLUSIONS

Endoscopic multi-punctures of BTX-A including fundic injections may decrease body weight and BMI by delaying the gastric emptying time. The effect of BTX-A on ghrelin levels may also be involved in the reduction of appetite.

Prucalopride in the treatment of chronic constipation in patients from the Asia-Pacific region: a randomized, double-blind, placebo-controlled study

BACKGROUND

The study evaluated efficacy and safety of the 2 mg dose of prucalopride compared to placebo in patients with chronic constipation (CC) from the Asia-Pacific region.

METHODS

Randomized, placebo-controlled, parallel-group, phase III study with 2-week run-in, 12-week treatment phase, and 1-week follow-up. Adult patients with CC (≤2 spontaneous bowel movements per week) received 2 mg prucalopride or placebo, once-daily, for 12 weeks. Primary efficacy measure was percentage of patients with average of ≥3 spontaneous complete bowel movements (SCBMs) per week (Responders) during the 12-week treatment. A key secondary endpoint was Responders during first 4 weeks of treatment. Other efficacy assessments were based on patient diaries, their assessments of symptoms and quality of life, and investigator's assessment on efficacy of treatment. Safety assessments included adverse events, laboratory values, and cardiovascular events.

KEY RESULTS

Efficacy and safety were evaluated for 501 patients who received study drug. On the primary endpoint, prucalopride was significantly more effective than placebo with 83 (33.3%) vs 26 (10.3%) patients having a weekly average of ≥3 SCBMs during the 12-week treatment (P < 0.001). Respective percentages were 34.5%vs 11.1% over first 4 weeks (P < 0.001). On other secondary endpoints, clinical improvement was generally larger and statistically superior (P < 0.001) in the prucalopride group. Most frequently reported adverse events were diarrhea, nausea, abdominal pain, and headache.

CONCLUSION & INFERENCES

Prucalopride 2 mg given once-daily significantly improved bowel function, associated symptoms, and satisfaction in CC over a 12-week treatment period, and was safe and well tolerated by patients in the Asia-Pacific region.

A small-molecule screen identifies L-kynurenine as a competitive inhibitor of TAA1/TAR activity in ethylene-directed auxin biosynthesis and root growth in Arabidopsis

The interactions between phytohormones are crucial for plants to adapt to complex environmental changes. One example is the ethylene-regulated local auxin biosynthesis in roots, which partly contributes to ethylene-directed root development and gravitropism. Using a chemical biology approach, we identified a small molecule, l-kynurenine (Kyn), which effectively inhibited ethylene responses in Arabidopsis thaliana root tissues. Kyn application repressed nuclear accumulation of the ETHYLENE INSENSITIVE3 (EIN3) transcription factor. Moreover, Kyn application decreased ethylene-induced auxin biosynthesis in roots, and TRYPTOPHAN AMINOTRANSFERASE OF ARABIDOPSIS1/TRYPTOPHAN AMINOTRANSFERASE RELATEDs (TAA1/TARs), the key enzymes in the indole-3-pyruvic acid pathway of auxin biosynthesis, were identified as the molecular targets of Kyn. Further biochemical and phenotypic analyses revealed that Kyn, being an alternate substrate, competitively inhibits TAA1/TAR activity, and Kyn treatment mimicked the loss of TAA1/TAR functions. Molecular modeling and sequence alignments suggested that Kyn effectively and selectively binds to the substrate pocket of TAA1/TAR proteins but not those of other families of aminotransferases. To elucidate the destabilizing effect of Kyn on EIN3, we further found that auxin enhanced EIN3 nuclear accumulation in an EIN3 BINDING F-BOX PROTEIN1 (EBF1)/EBF2-dependent manner, suggesting the existence of a positive feedback loop between auxin biosynthesis and ethylene signaling. Thus, our study not only reveals a new level of interactions between ethylene and auxin pathways but also offers an efficient method to explore and exploit TAA1/TAR-dependent auxin biosynthesis.

Genetic polymorphism of catechol O-methyltransferase and pharmacokinetics of levodopa in healthy Chinese subjects

We studied the distribution of catechol O-methyltransferase (COMT) genotypes in the Chinese Fujian Han population and explored the potential effect of COMT genetic polymorphism on the pharmacokinetics of levodopa. Polymerase chain reaction (PCR) was employed in the COMT genotype analysis of 166 volunteers. After a single oral dose of levodopa/benserazide, the plasma concentration of levodopa was determined by high-performance liquid chromatography (HPLC) with electrochemical detection (ECD). In the 166 subjects, the frequencies of G/G, G/A and A/A COMT genotypes were 58.4%, 36.7% and 4.9%, respectively. The frequency of the homozygous A/A genotype was much lower than in caucasians and Southwest Asians. COMT activity of erythrocytes in the G/A genotype group was significantly lower than in the G/G genotype group but significantly higher than in the A/A genotype group. There was no significant difference in pharmacokinetic parameters, including t(1/2alpha), t(1/2beta), AUC(0-infinity), CL/F, C(max), t(max) and V/F. The frequency of COMT genotypes in the Chinese Fujian Han population, which is related to COMT enzyme activity, is significantly different from that in caucasians and Southwest Asians. The pharmacokinetic characteristics of levodopa in healthy Chinese subjects may not be dependent on their COMT genotype status. From the 166 volunteers, 5 G/G, 5 G/A and 4 A/A genotype male subjects were recruited for the study of levodopa pharmacokinetics.