Effect of sacubitril valsartan on heart failure with mid-range or preserved ejection fraction in patients on maintenance hemodialysis: real-world experience in a single-center, prospective study.

BACKGROUND: This study aimed to evaluate the effect of sacubitril valsartan (SV) on heart failure (HF) hospitalization and cardiovascular mortality in patients on hemodialysis with HF with preserved ejection fraction (EF; HFpEF). METHODS: This single-center, prospective study enrolled 155 stable hemodialysis patients with EF > 40% who were followed up for 12 months. Fifty-nine patients were treated with SV; the others were matched for EF (57.89 ± 9.35 vs. 58.00 ± 11.82, P = 0.9) at a ratio of 1:1 and included as controls. The target dosage of SV was 200 mg/day. RESULTS: Twenty-three (23/155; 14.84%) had HF with mid-range EF (HFmrEF), while 132 (85.16%) had HFpEF. After SV treatment, the peak early diastolic transmitral flow velocity/peak early diastolic mitral annular tissue velocity(E/e') improved from 17.19 ± 8.74 to 12.80 ± 5.52 (P = 0.006), the left ventricular (LV) end-diastolic diameter decreased from 53.14 ± 7.67 mm to 51.56 ± 7.44 mm (P = 0.03), and the LV mass index decreased from 165.7 ± 44.6 g/m2 to 154.8 ± 24.0 g/m2 (P = 0.02). LVEF (P = 0.08) and LV global longitudinal strain (P = 0.7) did not change significantly. The composite outcome of first and recurrent HF hospitalization or cardiovascular death showed no difference between group. However, the Acute Dialysis Quality Initiative Workgroup (ADQI) HF class improved in 39 and 15 patients and worsened in 1 and 11 patients in the SV and control groups, respectively (P < 0.001). Age, diabetes mellitus, and pulmonary arterial pressure were independent risk factors for HF hospitalization and cardiovascular mortality in patients with HFpEF. CONCLUSIONS: SV improved LV hypertrophy, diastolic function, and the ADQI class for HF; however, it failed to reduce the composite endpoints of HF hospitalization and cardiovascular disease-related mortality over 12 months of follow-up in patients on maintenance hemodialysis with EF of > 40%.

Effect of proximal artery restriction on flow reduction and cardiac function in hemodialysis patients with high-flow arteriovenous fistulas.

OBJECTIVE: Arteriovenous fistula is the preferred vascular access for hemodialysis patients. High-flow arteriovenous fistula may cause high-output heart failure. Various procedures are used to reduce high-flow arteriovenous fistula. This study aimed to assess the efficacy of proximal artery restriction combined with distal artery ligation on flow reduction for high-flow arteriovenous fistula and on cardiac function and echocardiographic changes in patients undergoing hemodialysis. METHODS: A retrospective analysis was performed on data collected from the medical records of patients undergoing hemodialysis with heart failure and high-flow arteriovenous fistula between May 2018 and May 2021. Thirty-one patients were treated with proximal artery restriction (banding juxta-anastomosis of the proximal artery) combined with distal artery ligation (anastomosis distal artery ligation). Changes in the Acute Dialysis Quality Initiative Workgroup cardiac function class, blood pressure, and echocardiography before and 6 months after flow restriction were compared, and post-intervention primary patency was followed-up. RESULTS: The technical success rate of the surgery was 100%, and no surgery-related adverse events occurred. Blood flow and blood flow/cardiac output decreased significantly after flow restriction. Blood flow decreased from 2047.21 ± 398.08 mL/min to 1001.36 ± 240.42 mL/min, and blood flow/cardiac output decreased from 40.18% ± 6.76% to 22.34% ± 7.21% (P < .001). Post-intervention primary patency of arteriovenous fistula at 6, 12, and 24 months was 96.8%, 93.5%, and 75.2%, respectively. The Acute Dialysis Quality Initiative Workgroup cardiac function class improved significantly after 6 months of flow restriction (P < .001). The systolic and diastolic left heart function improved, as evidenced by a significant decrease in left atrial volume index, left ventricular end-diastolic/end-systolic diameters, left ventricular end-diastolic volume, left ventricular mass index, cardiac output, and cardiac index and an increase in lateral peak velocity of longitudinal contraction, average septal-lateral s', and lateral early diastolic peak velocity after flow restriction (P < .05). Systolic pulmonary artery pressure decreased from 32.36 ± 8.56 mmHg to 27.57 ± 8.98 mmHg (P < .05), indicating an improvement in right heart function. CONCLUSIONS: Proximal artery restriction combined with distal artery ligation effectively reduced the blood flow of high-flow arteriovenous fistula and improved cardiac function.

Bridging the Interfacial Contact for Improved Stability and Efficiency of Inverted Perovskite Solar Cells.

Inverted perovskite solar cells (PSCs) have received widespread attention due to their facile fabrication and wide applications. However, their power conversion efficiency (PCE) is reported lower than that of regular PSCs because of the undesirable interfacial contact between perovskite and the hydrophobic hole transport layer (HTL). Here, an interface regulation strategy is proposed to overcome this limitation. A small molecule ([2-(9H-carbazol-9-yl) ethyl] phosphonic acid, abbreviated as 2P), composed of carbazole and phosphonic acid groups, is inserted between perovskite and HTL. Morphological characterization and theoretical calculation reveal that perovskite bonds stronger on 2P-modified HTL than on pristine HTL. The improved interfacial contact facilitates hole extraction and retards degradation. Upon the incorporation of 2P, inverted PSCs deliver a high PCE of over 22% with superior stability, keeping 84.6% of initial efficiency after 7200 h storage under an ambient atmosphere with a relative humidity of ≈30-40%. This strategy provides a simple and efficient way to boost the performance of inverted PSCs.

In Situ Reconstructed Zn doped Fex Ni(1- x ) OOH Catalyst for Efficient and Ultrastable Oxygen Evolution Reaction at High Current Densities.

Developing FeOOH as a robust electrocatalyst for high output oxygen evolution reaction (OER) remains challenging due to its low conductivity and dissolvability in alkaline conditions. Herein, it is demonstrated that the robust and high output Zn doped NiOOH-FeOOH (Zn-Fex Ni(1-x) )OOH catalyst can be derived by electro-oxidation-induced reconstruction from the pre-electrocatalyst of Zn modified Ni metal/FeOOH film supported by nickel foam (NF). In situ Raman and ex situ characterizations elucidate that the pre-electrocatalyst undergoes dynamic reconstruction occurring on both the catalyst surface and underneath metal support during the OER process. That involves the Fe dissolution-redeposition and the merge of Zn doped FeOOH with in situ generated NiOOH from NF support and NiZn alloy nanoparticles. Benefiting from the Zn doping and the covalence interaction of FeOOH-NiOOH, the reconstructed electrode shows superior corrosion resistance, and enhanced catalytic activity as well as bonding force at the catalyst-support interface. Together with the feature of superaerophobic surface, the reconstructed electrode only requires an overpotential of 330 mV at a high-current-density of 1000 mA cm-2 and maintains 97% of its initial activity after 1000 h. This work provides an in-depth understanding of electrocatalyst reconstruction during the OER process, which facilitates the design of high-performance OER catalysts.

Ternary 14-electron XB2Be2 (X = Si, Ge, Sn, Pb) clusters: a planar tetracoordinate silicon (ptSi) system and its ptGe/Sn/Pb congeners.

A class of ternary 14-electron clusters, XB2Be2 (X = Si, Ge, Sn, Pb), have been computationally predicted with a planar tetracoordinate silicon (ptSi) unit, as well as its heavier ptGe/Sn/Pb congeners. These pentaatomic ptSi/Ge/Sn/Pb species are established as global-minimum structures via computer global searches, followed by electronic structure calculations at the PBE0-D3, B3LYP-D3, and single-point CCSD(T) levels. Molecular dynamics simulations indicate that they are also kinetically stable against isomerization or decomposition. Chemical bonding analyses show that the clusters have double 2π/2σ aromaticity. The latter concept underlies the stability of ptSi/Ge/Sn/Pb clusters, overriding the 14-electron count or its variants, such as the 18-electron rule. No sp3 hybridization occurs in these species, which naturally explains why they are ptSi/Ge/Sn/Pb (rather than traditional tetrahedral) systems.

Atomic force microscopy for revealing micro/nanoscale mechanics in tumor metastasis: from single cells to microenvironmental cues.

Mechanics are intrinsic properties which appears throughout the formation, development, and aging processes of biological systems. Mechanics have been shown to play important roles in regulating the development and metastasis of tumors, and understanding tumor mechanics has emerged as a promising way to reveal the underlying mechanisms guiding tumor behaviors. In particular, tumors are highly complex diseases associated with multifaceted factors, including alterations in cancerous cells, tissues, and organs as well as microenvironmental cues, indicating that investigating tumor mechanics on multiple levels is significantly helpful for comprehensively understanding the effects of mechanics on tumor progression. Recently, diverse techniques have been developed for probing the mechanics of tumors, among which atomic force microscopy (AFM) has appeared as an excellent platform enabling simultaneously characterizing the structures and mechanical properties of living biological systems ranging from individual molecules and cells to tissue samples with unprecedented spatiotemporal resolution, offering novel possibilities for understanding tumor physics and contributing much to the studies of cancer. In this review, we survey the recent progress that has been achieved with the use of AFM for revealing micro/nanoscale mechanics in tumor development and metastasis. Challenges and future progress are also discussed.

Lipoxin A4 ameliorates lipopolysaccharide-induced lung injury through stimulating epithelial proliferation, reducing epithelial cell apoptosis and inhibits epithelial-mesenchymal transition.

BACKGROUND: Acute respiratory distress syndrome (ARDS) is characterized by alveolar epithelial disruption. Lipoxins (LXs), as so-called "braking signals" of inflammation, are the first mediators identified to have dual anti-inflammatory and inflammatory pro-resolving properties. METHODS: In vivo, lipoxinA4 was administrated intraperitoneally with 1 µg/per mouse after intra-tracheal LPS administration (10 mg/kg). Apoptosis, proliferation and epithelial-mesenchymal transition of AT II cells were measured by immunofluorescence. In vitro, primary human alveolar type II cells were used to model the effects of lipoxin A4 upon proliferation, apoptosis and epithelial-mesenchymal transition. RESULTS: In vivo, lipoxin A4 markedly promoted alveolar epithelial type II cells (AT II cells) proliferation, inhibited AT II cells apoptosis, reduced cleaved caspase-3 expression and epithelial-mesenchymal transition, with the outcome of attenuated LPS-induced lung injury. In vitro, lipoxin A4 increased primary human alveolar epithelial type II cells (AT II cells) proliferation and reduced LPS induced AT II cells apoptosis. LipoxinA4 also inhibited epithelial mesenchymal transition in response to TGF-ß1, which was lipoxin receptor dependent. In addition, Smad3 inhibitor (Sis3) and PI3K inhibitor (LY294002) treatment abolished the inhibitory effects of lipoxinA4 on the epithelial mesenchymal transition of primary human AT II cells. Lipoxin A4 significantly downregulated the expressions of p-AKT and p-Smad stimulated by TGF-ß1 in primary human AT II cells. CONCLUSION: LipoxinA4 attenuates lung injury via stimulating epithelial cell proliferation, reducing epithelial cell apoptosis and inhibits epithelial-mesenchymal transition.

In vivo detecting mouse persistent hyperplastic primary vitreous by Spectralis Optical Coherence Tomography.

To identify imaging characteristics of mouse persistent hyperplastic primary vitreous (PHPV) by Spectralis Optical Coherence Tomography (OCT), as well as to assess and compare the sensitivity and precision of OCT with color photography (CP) and Fundus Fluorescein Angiography (FFA) imaging in detecting mouse PHPV. Notch4-/- C57BL/6J mice (224 eyes) aged from 3 months to 7 months were examined in this study. CP, FFA and OCT imaging were utilized to examine vitreous cavity and retina of mouse eyes. Horizontal and radial OCT scan volume was centered on the optic nerve head. Hematoxylin and eosin (H&E) staining was performed to validate PHPV. For color photography and FFA imaging, retrolental irregular fibrovascular membrane-like tissues were found in 33 eyes with/without blood vessels in vitreous cavity. Among them, 31 eyes were visualized with lateral and oblique linear hyperreflective opacities in vitreous cavity using Spectralis OCT. Position of PHPV in posterior segment of eyes was also measured via OCT. Mouse PHPV was validated by H&E staining. Typical hyperreflective opacities in vitreous cavity were detected in PHPV mouse using Spectralis OCT. Spectralis OCT imaging can effectively detect mouse PHPV as color photography and FFA.

A Gyroidal MOF with Unprecedented Interpenetrating utc-c Network Exhibiting Exceptional Thermal Stability and Ultrahigh CO2 Affinity.

A zeolite-like gyroidal MOF (denoted as SCNU-1) constructed with Cu ions and 4-(1H-imidazo[4,5-f][1,10]phenanthrolin-2-yl)phenol has a featured interpenetrating uninodal utc-c network which is for the first time found in the real structure. Moreover, SCNU-1 exhibits high thermal (>773 K), solvent, and acid/base stabilities; the largest CO2 affinity, 90 kJ/mol, among the MOFs functionalized with an aromatic hydroxyl group; and excellent CO2/N2 selectivity.

A comparative study on arsenic fractions in indoor/outdoor particulate matters: a case in Baoding, China.

The distribution and bioavailability of arsenic (As) in indoor/outdoor total suspended particulates (TSP), inhalable particulate matters (PM10), and fine particulate matters (PM2.5) in Baoding, China were investigated. The average I/O ratios for TSP, PM10, and PM2.5 were 0.52, 0.66, and 0.96, respectively. There was no significant correlation between indoor/outdoor TSP, PM10, and PM2.5. The indoor/outdoor concentrations of As surpassed the limited value of As. I/O ratios of arsenic in TSP, PM10, and PM2.5 were 0.52, 0.58, and 0.55, respectively. The contents of arsenic in different fractions were mainly affected by the total concentrations of arsenic in particulate matters (PM) rather than the particle sizes for TSP and PM10. Arsenic was mainly in non-specifically sorbed fraction (F1) in both indoor and outdoor PM2.5. The evaluated carcinogenic risk (CR) was within the safe level. The bioavailability of As increased with particle size decreasing for both indoor and outdoor PM. The potential bioavailability of As in outdoor particles was higher than that of indoor particles with the same size, especially PM2.5.

Surface structure, optoelectronic properties and charge transport in ZnO nanocrystal/MDMO-PPV multilayer films.

Blends of semiconducting nanocrystals and conjugated polymers continue to attract major research interest because of their potential applications in optoelectronic devices, such as solar cells, photodetectors and light-emitting diodes. In this study we investigate the surface structure, morphological and optoelectronic properties of multilayer films constructed from ZnO nanocrystals (NCs) and poly[2-methoxy-5-(3',7'-dimethyloctyloxy)-1,4-phenylenevinylene] (MDMO-PPV). The effects of layer number and ZnO concentration (CZnO) used on the multilayer film properties are investigated. An optimised solvent blend enabled well-controlled layers to be sequentially spin coated and the construction of multilayer films containing six ZnO NC (Z) and MDMO-PPV (M) layers (denoted as (ZM)6). Contact angle data showed a strong dependence on CZnO and indicated distinct differences in the coverage of MDMO-PPV by the ZnO NCs. UV-visible spectroscopy showed that the MDMO-PPV absorption increased linearly with the number of layers in the films and demonstrates highly tuneable light absorption. Photoluminescence spectra showed reversible quenching as well as a surprising red-shift of the MDMO-PPV emission peak. Solar cells were constructed to probe vertical photo-generated charge transport. The measurements showed that (ZM)6 devices prepared using CZnO = 14.0 mg mL-1 had a remarkably high open circuit voltage of ∼800 mV. The device power conversion efficiency was similar to that of a control bilayer device prepared using a much thicker MDMO-PPV layer. The results of this study provide insight into the structure-optoelectronic property relationships of new semiconducting multilayer films which should also apply to other semiconducting NC/polymer combinations.

The effect of labor epidural analgesia on maternal-fetal outcomes: a retrospective cohort study.

PURPOSE: To evaluate the impact of labor epidural analgesia on maternal-fetal safety outcomes in a signal Chinese academic medical center. METHODS: A single-intervention impact study was conducted at The Second Affiliated Hospital, Wenzhou Medical University. The study period was divided into three phases: (1) baseline phase: from January 1 and June 30, 2009 when no analgesic method was routinely employed during labor; (2) phase-in period: the epidural analgesia was implemented 8 a.m.-5 p.m. during weekdays; and (3) the post-No Pain Labor N'Delivery phase when the labor epidural was applied 24 h a day, 7 days a week, from June 1, 2010 and June 30, 2011. The maternal-fetal safety outcomes of delivery were compared between the different periods. RESULTS: There were 15,415 deliveries with 42.3% of nulliparous parturients in the 31-month study period. As the primary outcomes, the labor epidural analgesia rate increased from 0 to 57%, the vaginal delivery rate increased, and cesarean delivery rate decreased by 3.5% after full implementation. As the secondary outcomes, the rate of episiotomy and severe perineal injury after the implementation periods were significant decreased. The rate of postpartum oxytocin administration was decreased by 17.8%. No significant difference between the baseline and implementation periods was found in the rate of postpartum hemorrhage, Apgar scores less than 7 at both 1 and 5 min, 7-day mortality, and the overall neonatal intensive care unit admission rate. CONCLUSION: Implementation of labor epidural analgesia increased the vaginal delivery rate and use of labor epidural analgesia is safe to parturients and fetus.

[Clinical features and drug resistance in children with Salmonella infection].

OBJECTIVE: To study the clinical features and drug resistance in children with Salmonella infection. METHODS: A total of 163 children with positive fecal cultures for Salmonella who were hospitalized between 2013 and 2017 were enrolled. A retrospective analysis was performed for their data on clinical features, distribution of Salmonella serotypes, and drug sensitivity test results. RESULTS: Among the 163 children with Salmonella infection, 79 (48.5%) were aged ≤1 year. Main clinical manifestations included fever and diarrhea. Of all the children, 121 (74.2%) reached a body temperature of above 39°C, 52 (31.9%) had diarrhea more than 10 times a day, and 56 (34.4%) had respiratory infection. Salmonella infection often occurred in summer and autumn. Of all the children, 131 (80.4%) had the infection in May to October. Salmonella typhimurium was observed in 100 children (61.3%) and Salmonella enteritidis was observed 15 children (9.2%). All serotypes of Salmonella had a drug resistance rate of >20% to cefotaxime, as well as high sensitivities to ß-lactamase inhibitors (amoxicillin/clavulanic acid and piperacillin/tazobactam). There were no strains resistant to carbapenems including imipenem. CONCLUSIONS: Infants aged ≤1 year are susceptible to Salmonella infection in summer and autumn, and the most common serotype is Salmonella typhimurium. Main clinical manifestations are fever and diarrhea in children with Salmonella infection, and most children also have respiratory infection. Salmonella has an increased rate of drug resistance to third-generation cephalosporins. In clinical treatment, antimicrobial drugs should be used according to the results of drug sensitivity test.

Textured ZnO films from evaporation-triggered aggregation of nanocrystal dispersions and their use in solar cells.

Due to its high electron mobility, good stability and potential for low-temperature synthesis ZnO has received considerable attention for use in solar cells, photodetectors and sensors. Whilst there have been reports involving the formation ZnO films with porous morphologies the majority of those have involved elaborate or time-consuming preparation methods. In this study we investigate a simple new method for preparing textured porous ZnO (tp-ZnO) films. We used colloidal instability triggered by the evaporation of a volatile stabilising ligand during spin-coating of a ZnO nanocrystal (NC) dispersion to deposit crack-free tp-ZnO films. The porosity of the tp-ZnO films was 56% and they could be prepared using amine-based ligands with boiling points less than or equal to 78 °C. To demonstrate the ability to use the tp-ZnO films as electron acceptors they were infiltrated with poly(3-hexylthiophene) (P3HT) and solar cells prepared. The power conversion efficiencies of the tp-ZnO/P3HT devices reached values that were three times higher than a control bilayer ZnO/P3HT device prepared using a sol-gel derived ZnO film. Because our method used a low temperature treatment and ZnO films are used in a wide variety of third-generation solar cells, the new tp-ZnO films introduced here may offer a low cost method for improving the efficiency of other solar cells.

Anatomic variations of neck vessels and the course of pediatric internal jugular veins.

BACKGROUND: Landmark-guided internal jugular vein cannulation is difficult for pediatric patients but useful, especially when ultrasound equipment is unavailable. Therefore, it is important to define the adjacent anatomic characteristics of the pediatric internal jugular vein. METHODS: In 210 children the course of the internal jugular vein, and common carotid and vertebral arteries was measured from the level of the cricoid cartilage to the supraclavicular area using ultrasound. RESULTS: From the level of the cricoid cartilage to the supraclavicular area, vessel diameter increased with internal jugular vein increasing by 12%, and common carotid and vertebral arteries increasing by 5% each. From the level of the cricoid cartilage to the supraclavicular area, the number of patients with a medial common carotid artery position relative to the internal jugular vein increased, whereas those with a lateral position decreased; the number of patients with nonoverlapped common carotid artery-internal jugular vein increased, and those with totally overlapped decreased. In contrast, the overlapping status of vertebral artery-internal jugular vein changes oppositely. More than 97.14% of the vertebral artery lies lateral to the internal jugular vein at these levels. The minimal vertebral artery-internal jugular vein depth decreased from 0.46±0.20 to 0.37±0.19 cm. The angle from the internal jugular vein line to the horizontal line of the body was 83.35±9.04 degrees. CONCLUSION: The common carotid artery and internal jugular vein are farther apart as one moves down the neck, whereas the vertebral artery and internal jugular vein are getting together. Additionally, the diameter of the internal jugular vein increased.

[Application of Mycoplasma pneumoniae antibody and load index in the diagnosis of Mycoplasma pneumoniae pneumonia in children].

OBJECTIVE: To study the role of Mycoplasma pneumoniae (MP) load and antibody measurements in the diagnosis of MP pneumonia. METHODS: A total of 115 children with MP pneumonia and 400 healthy children were enrolled. The MP load and total antibody level were measured at different stages, and the MP load index (MPLI) was calculated. RESULTS: The cut-off value of MPLI for MP infection was 6.12. MPLI and total antibody titer increased during the course of the disease, while MP-DNA decreased rapidly. Within the same time of blood collection, the group with a higher MP load had a significantly higher total antibody titer than the group with a lower MP load (P<0.05). Within 2 weeks of the course of the disease, the negative antibody group had a significantly higher MPLI than the positive antibody group (P<0.05). CONCLUSIONS: MPLI provides a standardized quantitative value of MP-DNA and plays an important role in the early diagnosis of MP infection.

Deficiency of CDKN1A or both CDKN1A and CDKN1B affects the pubertal development of mouse Leydig cells.

Cyclin-dependent kinase inhibitors p21(Cip1) (CDKN1A) and p27(Kip1) (CDKN1B) are expressed in Leydig cells. Previously, we reported that Cdkn1b knockout in the mouse led to increased Leydig cell proliferative capacity and lower steroidogenesis. However, the relative importance of CDKN1A and CDKN1B in these regulations was unclear. In the present study, we examined the relative importance of CDKN1A and CDKN1B in regulation of Leydig cell proliferation and steroidogenesis by whole-body knockout of CDKN1A (Cdkn1a(-/-)) and CDKN1A/CDKN1B double knockout (DBKO). The cell number, 5-bromo-2-deoxyuridine incorporation rate, steroidogenesis, and steroidogenic enzyme mRNA levels and activities of Leydig cells were compared among wild-type (WT), Cdkn1a(-/-), and DBKO mice. Relative to WT mice, Leydig cell number per testis was doubled in the DBKO and unchanged in the Cdkn1a(-/-) mice. Testicular testosterone levels and mRNA levels for luteinizing hormone receptor (Lhcgr), steroidogenic acute regulatory protein (Star), cholesterol side-chain cleavage enzyme (Cyp11a1), 17alpha-hydroxylase/17,20-lyase (Cyp17a1), and 17beta-hydroxysteroid dehydrogenase 3 (Hsd17b3) and their respective proteins were significantly lower in the DBKO mice. However, testicular testosterone level was unchanged in the Cdkn1a(-/-) mice, although Lhcgr mRNA levels were significantly lower relative to those in the WT control. We conclude that Cdkn1a(-/-) did not increase Leydig cell numbers (although a defect of Leydig cell function was noted), whereas DBKO caused a significant increase of Leydig cell numbers but a decrease of steroidogenesis.

In vitro and in vivo characterization of 13 CYP2C9 allelic variants found in Chinese Han population.

Our previous study detected totally 35 CYP2C9 allelic variants in 2127 Chinese subjects, of whom 21 novel alleles were reported for the first time in Chinese populations. The aim of the present study was to characterize the 13 CYP2C9 allelic variants both in vitro and in vivo. Different types of CYP2C9 variants were highly expressed in COS-7 cells, and 50 µM tolbutamide was added as the probing substrate to evaluate their metabolic abilities in vitro. Subsequently, the concentrations of tolbutamide and its metabolite in the plasma and urine within individuals with different types of genotypes were determined by HPLC to evaluate the catalytic activity of the 13 mutant CYP2C9 proteins in vivo. Our results showed that compared with *1/*1 wild-type subjects, subjects with *1/*40 genotype showed increased oral clearance (CL/F), whereas individuals with *1/*3, *1/*13, *3/*3, *3/*13, *1/*16, *1/*19, *1/*34, *1/*42, *1/*45, *1/*46, and *1/*48 genotype exhibited significantly decreased CL/F, and those with *1/*27, *1/*29, *1/*40, and *1/*41 genotype presented similar CL/F value. When expressed in COS-7 cells, the CYP2C9 variants showed similar pattern to the results in clinical study. The study suggests that, besides two typical defective alleles, *3 and *13, seven CYP2C9 allelic variants (*16, *19, *34, *42, *45, *46, and *48) cause defective effects on the enzymatic activities both in vitro and in vivo. In clinic, patients with these defective alleles should be paid close attention to.

Nanoscale monitoring of drug actions on cell membrane using atomic force microscopy.

Knowledge of the nanoscale changes that take place in individual cells in response to a drug is useful for understanding the drug action. However, due to the lack of adequate techniques, such knowledge was scarce until the advent of atomic force microscopy (AFM), which is a multifunctional tool for investigating cellular behavior with nanometer resolution under near-physiological conditions. In the past decade, researchers have applied AFM to monitor the morphological and mechanical dynamics of individual cells following drug stimulation, yielding considerable novel insight into how the drug molecules affect an individual cell at the nanoscale. In this article we summarize the representative applications of AFM in characterization of drug actions on cell membrane, including topographic imaging, elasticity measurements, molecular interaction quantification, native membrane protein imaging and manipulation, etc. The challenges that are hampering the further development of AFM for studies of cellular activities are aslo discussed.