Light Induced Proton Coupled Charge Transfer Triggers Counterion Directional Translocation

We demonstrate directed translocation of ClO4 - anions from cationic to neutral binding site along the synthetized BPym-OH dye molecule that exhibits coupled excited-state intramolecular proton-transfer (ESIPT) and charge-transfer (CT) reaction (PCCT). The results of steady-state and time-resolved spectroscopy together with computer simulation and modeling show that in low polar toluene the excited-state redistribution of electronic charge enhanced by ESIPT generates the driving force, which is much stronger than by CT reaction itself and provides more informative gigantic shifts of fluorescence spectra signaling on ultrafast ion motion. The associated with ion translocation red-shifted fluorescence band (at 750 nm, extending to near-IR region) appears at the time ~83 ps as a result of electrochromic modulation of PCCT reaction. It occurs at substantial delay to PCCT that displayed fluorescence band at 640 nm and risetime of <200 fs. Thus, it becomes possible to visualize the manifestations of light-triggered ion translocation and of its driving force by fluorescence techniques and to separate them in time and energy domains.

[Propensity score matching analysis of the short-term efficacy of Kamikawa versus double- tract reconstruction in laparoscopic proximal gastric cancer surgery]

Objective: To compare the short-term efficacy of Kamikawa anastomosis and double-tract reconstruction (DTR) after proximal gastrectomy. Methods: This was a propensity score matched, retrospective, cohort study. Inclusion criteria comprised age 20-70 years, diagnosis of gastric cancer by pathological examination of preoperative endoscopic biopsies, tumor diameter ≤4 cm, and location in the upper 1/3 of the stomach (including the gastroesophageal junction), and TNM stage IA, IB, or IIA. The study cohort comprised 73 patients who had undergone laparoscopic proximal gastric cancer radical surgery in the Department of Gastroenterology, Tangdu Hospital, Air Force Medical University between June 2020 and February 2023, 19 of whom were in the Kamikawa group and 54 in the DTR group. After using R language to match the baseline characteristics of patients in a ratio of 1:2, there were 17 patients in the Kamikawa group and 34 in the DTR group. Surgery-related conditions, postoperative quality of life, and postoperative complications were compared between the two groups. Results: After propensity score matching, there were no statistically significant differences in baseline data between the two groups (P>0.05). Compared with the DTR group, the Kamikawa group had longer operative times (321.5±15.7 minutes vs. 296.8±26.1 minutes, t=32.056, P<0.001), longer anastomosis times (93.0±6.8 minutes vs. 45.3±7.7 minutes, t=56.303, P<0.001), and less bleeding (76 [54~103] mL vs.112 [82~148) mL, Z=71.536, P<0.001); these differences are statistically significant. There were no statistically significant differences between the two groups in tumor size, time to first postoperative passage of gas, postoperative hospital stay, number of lymph nodes removed, duration of lymph node dissection, or total hospitalization cost (all P>0.05). The median follow-up time was 6.1 ± 1.8 months. As to postoperative quality of life, the Kamikawa group had a lower rate of upper gastrointestinal contrast reflux than did the DTR group (0 vs. 29.4% [10/34], χ2=6.220, P=0.013); this difference is statistically significant. However, differences between the two groups in quality of life score on follow-up of 3 months and 6 months on the Gastroesophageal Reflux Disease (GERD) scale were not statistically significant (all P>0.05). The incidence of postoperative complications was 2/17 in the Kamikawa group, which is significantly lower than the 41.2% (14/34) in the DTR group (χ2=4.554, P=0.033). Conclusion: Kamikawa anastomosis and DTR are equally safe and effective procedures for reconstructing the digestive tract after proximal gastric surgery. Although Kamikawa anastomosis takes slightly longer and places higher demands on the surgical team, it is more effective at preventing postoperative reflux.

[Analysis of the therapeutic effect of aspiration thrombectomy for early carotid stent thrombosis]

Objective: To investigate the clinical characteristics and the efficacy of thrombus aspiration in patients with early intrastent thrombosis (EST) following carotid artery stenting (CAS). Methods: This study is a retrospective case series, collecting clinical data of five patients who developed EST after CAS in the Department of Neurosurgery, Beijing Chaoyang Hospital, Capital Medical University from January 2021 to September 2023.All patients were male, with an age of (64.0±11.9) years (range:48 to 77 years), accounting for 2.0% (5/244) of CAS procedures during the same period.Among them, three patients did not receive standard dual antiplatelet therapy before the procedure, and one had an inadequate ADP inhibition rate (45.6%).Four patients received XACT carotid stents, while one received a Wallstent carotid stent.All five patients showed significant residual stenosis ranging from 43% to 55% after CAS.Emergency thrombus aspiration was performed in all cases, and data regarding perioperative conditions, vascular patency, and clinical outcomes were collected. Results: The interval between CAS and the occurrence of EST ranged from 3 hours to 14 days.The main clinical symptoms included sudden onset of consciousness disorders and contralateral limb weakness.None of the patients received preoperative intravenous thrombolysis, and thrombus aspiration was performed during the procedure to restore vascular patency.Four cases underwent balloon angioplasty during the procedure, and two cases utilized overlapping stents.Two patients experienced intraoperative embolization of thrombus to the C2 segment.In one case, the embolized thrombus was retrieved using an intracranial thrombectomy stent, while in another case, it was aspirated using a guiding catheter.Postoperatively, all patients had a thrombolysis in cerebral infarction grade of 3, and symptoms improved in four cases.One patient showed no improvement in symptoms, and MRI revealed extensive new infarction in the right frontal and insular regions, adjacent to the right lateral ventricle.Regular follow-up examinations after discharge did not reveal restenosis or embolism within the stent.The follow-up period ranged from 7.6 to 21.2 months, with modified Rankin scale scores of 0 to 1 point in four cases and 2 points in one case, indicating good recovery in all patients. Conclusions: Acute intrastent thrombosis is a rare complication after carotid artery stenting.The combined use of percutaneous thrombus aspiration and endovascular techniques, such as balloon angioplasty and stent overlapping, can rapidly restore vessel patency with favorable outcomes.However, further large-scale clinical studies are needed to confirm the effectiveness of these treatments for acute intrastent thrombosis.

Arrayed Pt Single Atoms via Phosphotungstic Acids Intercalated in Silicate Nanochannels for Efficient Hydrogen Evolution Reactions

Single-atom catalysts, known for their high activity, have garnered significant interest. Currently, single-atom catalysts were prepared mainly on 2D substrates with random distribution. Here, we report a strategy for preparing arrayed single Pt (Pt1) atoms, which are templated through coordination with phosphotungstic acids (PTA) intercalated inside hexagonally packed silicate nanochannels for a high single Pt-atom loading of ca. 3.0 wt %. X-ray absorption spectroscopy, high-angle annular dark-field scanning transmission electron microscopy, and energy-dispersive X-ray spectroscopy, in conjunction with the density-functional theory calculation, collectively indicate that the Pt single atoms are stabilized via a four-oxygen coordination on the PTA within the nanochannels' inner walls. The critical reduction in the Pt-adsorption energy to nearly the cohesive energy of Pt clustering is attributed to the interaction between PTA and the silicate substrate. Consequently, the transition from single-atom dispersion to clustering of Pt atoms can be controlled by adjusting the number density of PTA intercalated within the silicate nanochannels, specifically when the number ratio of Pt atoms to PTA changes from 3.7 to 18. The 3D organized Pt1-PTA pairs, facilitated by the arrayed silicate nanochannels, demonstrate high and stable efficiency with a hydrogen production rate of ca. 300 mmol/h/gPt─approximately twice that of the best-reported Pt efficiency in polyoxometalate-based photocatalytic systems.

An integrative approach unveils a distal encounter site for rPTPε and phospho-Src complex formation

The structure determination of protein tyrosine phosphatase (PTP): phospho-protein complexes, which is essential to understand how specificity is achieved at the amino acid level, remains a significant challenge for protein crystallography and cryoEM due to the transient nature of binding interactions. Using rPTPεD1 and phospho-SrcKD as a model system, we have established an integrative workflow to address this problem, by means of which we generate a protein:phospho-protein complex model using predetermined protein structures, SAXS and pTyr-tailored MD simulations. Our model reveals transient protein-protein interactions between rPTPεD1 and phospho-SrcKD and is supported by three independent experimental validations. Measurements of the association rate between rPTPεD1 and phospho-SrcKD showed that mutations on the rPTPεD1: SrcKD complex interface disrupts these transient interactions, resulting in a reduction in protein-protein association rate and, eventually, phosphatase activity. This integrative approach is applicable to other PTP: phospho-protein complexes and the characterization of transient protein-protein interface interactions.

Selected-Lesion SRS as a Novel Strategy in Treatment of Patients with Multiple Brain Metastases

PURPOSE/OBJECTIVE(S)

With the increasing use of intracranial SRS (SRS) for treatment of patients with >10-15 brain metastases treatment; debate remains in the literature about how these patients should be treated. While many advocate for treatment of all lesions with either SRS or whole brain radiation therapy (WBRT), several groups are considering selected-lesion SRS (SL-SRS) where only a subset of intracranial lesions are treated. However, the current practice patterns of SL-SRS are not known.

MATERIALS/METHODS

A survey of 19 questions was created using open-ended and multiple-choice style questions on SL-SRS practices and indications. The survey was distributed to providers in the US and internationally who perform SRS frequently. Ten out of 50 institutions provided responses reflecting the practices of 16 providers. Descriptive statistics was used to compare answers to each question when applicable including percentages and ranges.

RESULTS

SL-SRS was performed at 8/10 institutions, (5 out of 6 US institutions and 3 out of 4 international institutions). Only 2 institutions had established clinical indications for SL-SRS (one in the US and one internationally) and one additional US institution reported clinical trials that require SL-SRS to study efficacy of CNS penetrating targeted therapies. One program reported research protocols for untreated brain metastases that would take priority over SL-SRS (program outside the US). Size of the lesion was cited as the most important factor (90%) when deciding to treat any single lesion. Next, lesion location and focal signs/symptoms were both considered moderately important. 80% ranked distance from prior SRS as the least important factor. Perilesional edema was also less important at most programs (90%). Lesion location and presence of symptoms were also considered important. There were several factors that would encourage providers to consider SL-SRS in a patient. Prior WBRT; progressing systemic disease and CNS-penetrating drug option available; and progressing systemic disease and immunotherapy option available were the most common responses. Most respondents cited "specific request by medical oncology" as well as "cooperative studies in this topic" as factors that might push them towards SL-SRS. Several institutions specified factors beyond the listed options. One institution reported that for patients with >20 lesions, they treated the largest lesions with SRS then follow with WBRT, termed the "pre-WBRT boost." Progression of untreated lesions was the most common reason why providers would bring back patients for additional treatment.

CONCLUSION

The responses to this survey demonstrate that patients with >15-20 intracranial lesions, prior WBRT, and worsening systemic disease with CNS penetrating systemic therapies available are being considered for SL-SRS.

Long-range hydrogen-bond relay catalyses the excited-state proton transfer reaction

Solvent (e.g., water)-catalyzed proton transfer (SCPT) via the relay of hydrogen (H)-bonds plays a key role in proton migration. In this study, a new class of 1H-pyrrolo[3,2-g]quinolines (PyrQs) and their derivatives were synthesized, with sufficient separation of the pyrrolic proton donating and pyridinic proton accepting sites to probe excited-state SCPT. There was dual fluorescence for all PyrQs in methanol, i.e., normal (PyrQ) and tautomer 8H-pyrrolo[3,2-g]quinoline (8H-PyrQ) emissions. The fluorescence dynamics unveiled a precursor (PyrQ) and successor (8H-PyrQ) relationship and the correlation of an increasing overall excited-state SCPT rate (kSCPT) upon increasing the N(8)-site basicity. kSCPT can be expressed by the coupling reaction kSCPT = Keq × kPT, where kPT denotes the intrinsic proton tunneling rate in the relay and Keq denotes the pre-equilibrium between randomly and cyclically H-bonded solvated PyrQs. Molecular dynamics (MD) simulation defined the cyclic PyrQs and analyzed the H-bond and molecular arrangement over time, which showed the cyclic PyrQs incorporating ≧3 methanol molecules. These cyclic H-bonded PyrQs are endowed with a relay-like proton transfer rate, kPT. MD simulation estimated an upper-limited Keq value of 0.02-0.03 for all studied PyrQs. When there was little change in Keq, the distinct kSCPT values for PyrQs were at different kPT values, which increased as the N(8) basicity increased, which was induced by the C(3)-substituent. kSCPT was subject to a deuterium isotope effect, where the kSCPT of 1.35 × 1010 s-1 for PyrQ-D in CH3OD was 1.68 times slower than that (2.27 × 1010 s-1) of PyrQ in CH3OH. MD simulation provided a similar Keq for PyrQ and PyrQ-D, leading to different proton tunneling rates (kPT) between PyrQ and PyrQ-D.

The expression of cytokeratin and apoptosis-related molecules in echinococcosis related liver injury

The study aimed to investigate the expression of cytokeratin and apoptosis-related molecules in the livers of two types of hepatic echinococcosis mice models and to preliminarily explore the relationship between the expression of cytokeratin and apoptosis in echinococcosis related liver injury. We established a mouse model infected by Echinococcus granulosus and Echinococcus multilocularis and observed the expression of cytokeratin and apoptosis related proteins in the two types of hepatic echinococcosis tissues during different stages by immunohistochemical staining. A co-culture model was established using normal hepatocytes and different concentrations of E. granulosus and E. multilocularis protoscoleces. Cell Counting Kit-8 was used to detect cell proliferation, flow cytometry was used to detect hepatocyte apoptosis, and western blot was used to quantify cytokeratin and apoptosis-related proteins, such as caspase3, caspase9, Bcl-2, and Bax. Surgical specimens were obtained from patients with hepatic echinococcosis to analyze the expressions of cytokeratin, caspase3, caspase9, Bcl-2, and Bax by western blot. The expressions of cytokeratin and caspase3 were analyzed by immunohistochemistry. The qRT-PCR method was used to determine the expression of CK8 and CK18 in the liver tissues. In vivo experiments showed that compared to that in the control group, the cytokeratin and caspase3 proteins in the liver tissues of the two types of hepatic echinococcosis were strongly expressed around the lesions of liver echinococcosis; there was a difference between cytokeratin expression of the two different echinococcosis parasites in the liver. Echinococcus granulosus and Echinococcus multilocularis in the co-culture model in vitro could promote the expression of CK, caspase3, caspase9, and Bax protein, decrease the expression of Bcl-2, promote hepatocyte apoptosis, and inhibit cell proliferation; in clinical samples, we found that compared with that in the normal tissues, the expression of cytokeratin, caspase3, caspase9, and Bax in echinococcus tissues was high, but that in Bcl-2 was low. Furthermore, the expression of CK8 and CK18 mRNA were higher in echinococcus tissues than that in the normal tissues and immunohistochemistry analysis also showed that cytokeratin and caspase3 levels were higher in echinococcus tissues than that in the normal tissues. The expression of cytokeratin and apoptosis-related molecules, reflecting liver damage, is high in the liver and is caused due to hepatic echinococcosis. This study provides the first evidence of cytokeratin could be useful for evaluating liver tissue damage caused by echinococcus infection.

Calculation of CYP450 protein-ligand binding and dissociation free energy paths

The function of an enzyme depends on its dynamic structure, and the catalytic mechanism has long been an active focus of research. The principle for interpreting protein selectivity and fidelity stems from optimization of the active site upon protein-substrate complexation, i.e., a lock-and-key configuration, on which most protein-substrate molecule binding recognition, and hence drug discovery, relies. Yet another thought has been to incorporate the protein folding interior tunnels for stereo- and regio-selectivity along the protein-substrate or protein-ligand/inhibitor binding process. Free energy calculations provide valuable information for molecular recognition and protein-ligand binding dynamics and kinetics. In this study, we focused on the kinetics of cytochrome P450 proteins (CYP450s) and the protein interior tunnel structure-dynamics relationship in terms of the substrate binding and leaving mechanism. A case in point is given by the prostaglandin H₂ (PGH₂) homologous isomerase of prostacyclin synthase. To calculate the reactant and product traversing the tunnels to and from the heme site, the free energy paths and tunnel potentials of mean force are constructed from steered molecular dynamics simulations and adaptive basing force umbrella sampling simulations. We explore the binding tunnels and critical residue lining characteristics for the ligand traverse and the underlying mechanism of CYP450 activity. Our theoretical analysis provides insights into the decisive role of the substrate tunnel binding process of the CYP450 mechanism and may be useful in drug design and protein engineering contexts.

The Diagnostic Value of Serum ST8SIA6-AS1 as Biomarker in Hepatocellular Carcinoma

BACKGROUND

Long noncoding RNA (lncRNA) is a promising serum biomarker in cancer diagnosis. However, literature on the diagnostic value of the lncRNA for hepatocellular carcinoma (HCC) is scant.

METHODS

The expression of ST8SIA6-AS1 in serum and HCC cell lines was detected by real-time PCR (RT-PCR). We then analyzed the relationship between clinicopathological characteristics and serum ST8SIA6-AS1 expression. In addition, we performed the receiver operating characteristic (ROC) curve and area under curve (AUC) analyses to determine the diagnostic ability of serum ST8SIA6-AS1.

RESULTS

Our data demonstrated an up-regulation of ST8SIA6-AS1 in 77 HCC patients and HCC cell lines. Besides, clinicopathological analysis revealed that ST8SIA6-AS1 corresponds with tumor stages and metastasis, thus might be used for monitoring the HCC progress. Importantly, the ROC analysis demonstrated that ST8SIA6-AS1 yields a superior diagnostic ability. Compared with α-fetoprotein (AFP) alone, a combination of ST8SIA6-AS1 and AFP may achieve more reliable diagnostic results.

CONCLUSIONS

Together, our results demonstrate that serum ST8SIA6-AS1 is a promising serum diagnostic bio-marker for HCC.

Effects of Inflammatory Disease on Clinical Progression and Treatment of Ischiogluteal Bursitis: A Retrospective Observational Study

Introduction:

The symptoms of Ischiogluteal Bursitis (IGB) are often nonspecific and atypical, and its diagnosis is more challenging. Moreover, it is difficult to predict cases of chronic progression or poor treatment response. Therefore, the aim of this study was to investigate the clinical course of IGB patients and identify factors that are predictive of failure of conservative treatment.

Materials and Methods:

Our study consisted of IGB patients diagnosed between 2010 March and 2016 December who had been followed-up for at least one year. Structured questionnaires and medical records were reviewed to analyse demographic characteristics, lifestyle patterns, blood tests, and imaging studies. We categorized the cases into two groups based on the response to conservative treatment and the need for surgical intervention.

Results:

The most common initial chief symptoms were buttock pains in 24 patients (37.5%). Physical examinations showed the tenderness of ischial tuberosity area in 59 (92.2%) patients, but no specific findings were confirmed in 5 patients (7.8%). 51 patients (79.7%) responded well to the conservative management, 11 patients (17.2%) needed injection, and 2 patients (3.1%) had surgical treatment performed due to continuous recurrence. There was no difference in demographic and blood lab data between the two groups. However, the incidence of inflammatory diseases (response group: 10.3% vs non-response group: 66.7%, p=0.004) was significantly different between the two groups.

Conclusion:

The diagnosis of IGB can be missed due to variations in clinical symptoms, and cautions should be exercised in patients with inflammatory diseases as conservative treatment is less effective in them, leading to chronic progression of IGB.

Could Chemical Reaction at the Molecular Level Show Distinction between Two Liquid-Water States? Study of the Excited-State Water-Catalyzed Proton Transfer Reaction Provides a Clue

The two liquid-water states, which lead to some anomalies when temperature crosses over 50 ± 10 °C at the atmospheric pressure, have been continuously catching popular attention. In this study, using the excited-state proton transfer (ESPT) catalyzed by water molecules as a prototypical reaction, we demonstrate that the kinetics of ESPT indeed is influenced by the two liquid-water states. In the water-catalyzed ESPT of 3-cyano-7-azaindole (3CAI), a repetitive and comprehensive temperature-dependent study of ESPT in H₂O from 0 to 90 °C shows anomalous behavior. The plot of the logarithm of ESPT rate constant as a function of inverse of absolute temperature deviates from a straight line. The convex-Arrhenius behavior manifests the activation free energy for water-assisted ESPT being dependent on temperature and hence the liquid water structure. To simplify the discussion, the plot is well fitted by using two straight lines that are crossed over in the vicinity of 40 °C. The free energy difference between water-solvated 3CAI and the 1:1 H₂O:3CAI complex is deduced to be 2.29 ± 0.04 and 1.96 ± 0.04 kcal·mol^-1 in the regions of 0-40 and 40-90 °C water, respectively, which also results in different frequency factors, i.e., the proton transfer/tunneling rates of (5.83 ± 0.36) × 10¹⁰ and (3.48 ± 0.27) × 10¹⁰ s^-1, respectively. In a qualitative manner, the results are then rationalized by the different types of H-bonding configuration as proposed for two liquid-water phases, rendering experimental evidence to support the different water phases in ambient temperatures at 1 bar.

Probing Interactions between Metal-Organic Frameworks and Freestanding Enzymes in a Hollow Structure

It has been reported that the biological functions of enzymes could be altered when they are encapsulated in metal-organic frameworks (MOFs) due to the interactions between them. Herein, we probed the interactions of catalase in solid and hollow ZIF-8 microcrystals. The solid sample with confined catalase is prepared through a reported method, and the hollow sample is generated by hollowing the MOF crystals, sealing freestanding enzymes in the central cavities of hollow ZIF-8. During the hollowing process, the samples were monitored by small-angle X-ray scattering (SAXS) spectroscopy, electron microscopy, powder X-ray diffraction (PXRD), and nitrogen sorption. The interfacial interactions of the two samples were studied by infrared (IR) and fluorescence spectroscopy. IR study shows that freestanding catalase has less chemical interaction with ZIF-8 than confined catalase, and a fluorescence study indicates that the freestanding catalase has lower structural confinement. We have then carried out the hydrogen peroxide degradation activities of catalase at different stages and revealed that the freestanding catalase in hollow ZIF-8 has higher activity.

SLEEP-GOAL: A multicenter success criteria outcome study on 302 obstructive sleep apnoea (OSA) patients

OBJECTIVE

To demonstrate SLEEP-GOAL as a more holistic and comprehensive success criterion for Obstructive Sleep Apnoea (OSA) treatment.

METHODS

A prospective 7-country clinical trial of 302 OSA patients, who met the selection criteria, and underwent nose, palate and/or tongue surgery. Pre- and post-operative data were recorded and analysed based on both the Sher criteria (apnoea hypopnea index, AHI reduction 50% and <20) and the SLEEP-GOAL.

RESULTS

There were 229 males and 73 females, mean age of 42.4±17.3 years, mean BMI 27.9±4.2. The mean VAS score improved from 7.7±1.4 to 2.5±1.7 (p<0.05), mean Epworth score (ESS) improved from 12.2±4.6 to 4.9±2.8 (p<0.05), mean body mass index (BMI) decreased from 27.9±4.2 to 26.1±3.7 (p>0.05), gross weight decreased from 81.9±14.3kg to 76.6±13.3kg. The mean AHI decreased 33.4±18.9 to 14.6±11.0 (p<0.05), mean lowest oxygen saturation (LSAT) improved 79.4±9.2% to 86.9±5.9% (p<0.05), and mean duration of oxygen <90% decreased from 32.6±8.9 minutes to 7.3±2.1 minutes (p<0.05). The overall success rate (302 patients) based on the Sher criteria was 66.2%. Crosstabulation of respective major/minor criteria fulfilment, based on fulfilment of two major and two minor or better, the success rate (based on SLEEP-GOAL) was 69.8%. Based solely on the Sher criteria, 63 patients who had significant blood pressure reduction, 29 patients who had BMI reduction and 66 patients who had clinically significant decrease in duration of oxygen <90% would have been misclassified as "failures".

CONCLUSION

AHI as a single parameter is unreliable. Assessing true success outcomes of OSA treatment, requires comprehensive and holistic parameters, reflecting true end-organ injury/function; the SLEEP-GOAL meets these requirements.

Unveiling the water-associated conformational mobility in the active site of ascorbate peroxidase

We carried out comprehensive spectroscopic studies of wild type and mutants of ascorbate peroxidase (APX) to gain understanding of the conformational mobility of the active site. In this approach, three unnatural tryptophans were applied to replace the distal tryptophan (W41) in an aim to probe polarity/water environment near the edge of the heme-containing active site. 7-azatryptophan ((7-aza)Trp) is sensitive to environment polarity, while 2,7-azatryptophan ((2,7-aza)Trp) and 2,6-diazatryptophan ((2,6-aza)Trp) undergo excited-state water-catalyzed double and triple proton transfer, respectively, and are sensitive to the water network. The combination of their absorption, emission bands and the associated relaxation dynamics of these fluorescence probes, together with the Soret-band difference absorption and resonance Raman spectroscopy, lead us to unveil the water associated conformational mobility in the active site of APX. The results are suggestive of the existence of equilibrium between two different environments surrounding W41 in APX, i.e., the water-rich and water-scant forms with distinct fluorescence relaxation. Our results thus demonstrate for the first time the power of integrating multiple sensors (7-aza)Trp, (2,7-aza)Trp and (2,6-aza)Trp in probing the water environment of a specifically targeted Trp in proteins.

Homology Modeling and Molecular Dynamics Simulation Combined with X-ray Solution Scattering Defining Protein Structures of Thromboxane and Prostacyclin Synthases

A combination of molecular dynamics (MD) simulations and X-ray scattering (SAXS) has emerged as the approach of choice for studying protein structures and dynamics in solution. This approach has potential applications for membrane proteins that neither are soluble nor form crystals easily. We explore the water-coupled dynamic structures of thromboxane synthase (TXAS) and prostacyclin synthase (PGIS) from scanning HPLC-SAXS measurements combined with MD ensemble analyses. Both proteins are heme-containing enzymes in the cytochrome P450 family, known as prostaglandin H₂ (PGH₂) isomerase, with counter-functions in regulation of platelet aggregation. Currently, the X-ray crystallographic structures of PGIS are available, but those for TXAS are not. The use of homology modeling of the TXAS structure with ns-μs explicit water solvation MD simulations allows much more accurate estimation of the configuration space with loop motion and origin of the protein behaviors in solution. In contrast to the stability of the conserved PGIS structure in solution, the pronounced TXAS flexibility has been revealed to have unstructured loop regions in connection with the characteristic P450 structural elements. The MD-derived and experimental-solution SAXS results are in excellent agreement. The significant protein internal motions, whole-molecule structures, and potential problems with protein folding, crystallization, and functionality are examined.

[Association of the expression of leptin and leptin receptor with bone metastasis in pulmonary adenocarcinoma]

Objective: To explore the association of expression of leptin and leptin receptor (LR) with bone metastasis of pulmonary adenocarcinoma. Methods: One hundred and sixteen pulmonary adenocarcinoma patients who had complete clinicopathological data and definite pathological diagnosis in our hospital from January 2008 to January 2010 were selected. They were divided into the metastasis (n= 58) and non-metastasis (control, n=58) groups. The expressions of leptin and LR were identified by immunohistochemistry. The differences between expressions of leptin and LR in primary pulmonary adenocarcinoma tissues and metastasis, and between the groups with and without bone metastasis were analyzed. We also analyzed the correlation of leptin and LR expressed in primary adenocarcinoma and bone metastatic tissues, and the relationship between their expression levels and bone metastasis free survival (BMFS). Results: Among 58 patients of the metastasis group, the cases of high, moderate and low expressions of leptin were 36, 15 and 7, respectively, and the cases of high, moderate and low expressions of LR were 32, 17 and 9, respectively. Among the 58 patients of control group, the cases of high, moderate and low expressions of leptin were 19, 24 and 15, respectively, and those of LR were 17, 16 and 25, respectively. The expressions of leptin and LR in primary pulmonary adenocarcinoma tissues of metastasis group were significantly different from those of the control group (P=0.006, P=0.002, respectively). The expressions of leptin and LR in primary pulmonary adenocarcinoma tissues of the bone metastasis group were also significantly different from those of the non-bone metastasis group (P=0.029, P=0.032, respectively). The high/moderate expression rates of leptin and LR in the bone-metastatic tissues reached 91.4% (32/35) and 88.6% (31/35), respectively. The results showed that the expressions of leptin and LR in primary pulmonary adenocarcinoma tissues were positively related with their expressions in bone metastatic tissue (r = 0.612). The median bone metastasis free survival (BMFS) of the bone metastasis groups with high, moderate and low expressions of leptin were 14, 21 and 47 months, respectively, and the median BMFS of high, moderate and low expressions of LR in the bone metastasis group were 13, 19 and 27 months, respectively. The expressions of leptin and LR in pulmonary adenocarcinoma were significantly associated with BMFS (P<0.001, P=0.006, respectively). Conclusions: The expressions of leptin and LR are significantly up-regulated in primary pulmonary adenocarcinoma tissues and bone metastatic tissues, and are negatively correlated with BMFS. These two molecules may be used as effective predictors of bone metastasis in pulmonary adenocarcinoma.

The In Situ Tryptophan Analogue Probes the Conformational Dynamics in Asparaginase Isozymes

Dynamic water solvation is crucial to protein conformational reorganization and hence to protein structure and functionality. We report here the characterization of water dynamics on the L-asparaginase structural homology isozymes L-asparaginases I (AnsA) and II (AnsB), which are shown via fluorescence spectroscopy and dynamics in combination with molecular dynamics simulation to have distinct catalytic activity. By use of the tryptophan (Trp) analog probe 2,7-diaza-tryptophan ((2,7-aza)Trp), which exhibits unique water-catalyzed proton-transfer properties, AnsA and AnsB are shown to have drastically different local water environments surrounding the single Trp. In AnsA, (2,7-aza)Trp exhibits prominent green N(7)-H emission resulting from water-catalyzed excited-state proton transfer. In stark contrast, the N(7)-H emission is virtually absent in AnsB, which supports a water-accessible and a water-scant environment in the proximity of Trp for AnsA and AnsB, respectively. In addition, careful analysis of the emission spectra and corresponding relaxation dynamics, together with the results of molecular dynamics simulations, led us to propose two structural states associated with the rearrangement of the hydrogen-bond network in the vicinity of Trp for the two Ans. The water molecules revealed in the proximity of the Trp residue have semiquantitative correlation with the observed emission spectral variations of (2,7-aza)Trp between AnsA and AnsB. Titration of aspartate, a competitive inhibitor of Ans, revealed an increase in N(7)-H emission intensity in AnsA but no obvious spectral changes in AnsB. The changes in the emission profiles reflect the modulation of structural states by locally confined environment and trapped-water collective motions.

[Expression of FoxM1 and BCRP in invasive breast carcinoma of no special type and its prognosis significance]

Objective: To investigate the relationship between expression of FoxM1 and BCRP in invasive breast carcinoma of no special type (IBC-NST) tissues and the clinical pathological characteristics and prognosis of the patients. Methods: Seventy-eight cases of IBC-NST with excision were included. The expression of FoxM1 and BCRP was assessed by immunohistochemistry and its relationship with the clinical pathological characteristics and prognosis was evaluated. Results: FoxM1 was expressed in 71.8%(56/78) of IBC-NST, and the expression was related to tumor diameter, TNM staging, ER, PR and HER2. BCRP was expressed in 53.8% (42/78) of IBC-NST, and the expression was related to age, tumor diameter, lymph node metastasis, ER and HER2. Kaplan-Meier survival analysis showed the survival time was related to tumor diameter, TNM staging, lymph node metastasis and the expression of FoxM1, BCRP, ER, PR and HER2. Cox multivariate analysis showed that TNM staging, FoxM1, BCRP, HER2 were determinants of patient survival time. Conclusions: The expression of FoxM1 is associated with tumor diameter, TNM staging, ER, PR and HER2 while BCRP is associated with age, tumor diameter, lymph node metastasis, ER and HER2. Both FoxM1 and BCRP have prognostic significance in IBC-NST patients.

Probing the polarity and water environment at the protein-peptide binding interface using tryptophan analogues

7-Azatryptophan and 2,7-diazatryptophan are sensitive to polarity changes and water content, respectively, and should be ideal for studying protein-protein and protein-peptide interactions. In this study, we replaced the tryptophan in peptide Baa (LKWKKLLKLLKKLLKLG-NH₂) with 7-azatryptophan or 2,7-diazatryptophan, forming (7-aza)Trp-Baa and (2,7-aza)Trp-Baa, to study the calmodulin (CaM)-peptide interaction. Dramatic differences in the (7-aza)Trp-Baa and (2,7-aza)Trp-Baa fluorescence properties between free peptide in water and calmodulin-bound peptide were observed, showing a less polar and water scant environment at the binding interface of the peptide upon calmodulin binding. The affinity of the peptides for binding CaM followed the trend Baa (210±10 pM)<(7-aza)Trp-Baa (109±5 pM)<(2,7-aza)Trp-Baa (45±2 pM), showing moderate increase in binding affinity upon increasing the number of nitrogen atoms in the Trp analogue. The increased binding affinity may be due to the formation of more hydrogen bonds upon binding CaM for the Trp analogue with more nitrogen atoms. Importantly, the results demonstrate that (7-aza)Trp and (2,7-aza)Trp are excellent probes for exploring the environment at the interface of protein-peptide interactions.

[Effect of bufalin on proliferation and apoptosis through ERK/RSK2 pathway in human esophageal carcinoma cell line xenografts in nude mice]

OBJECTIVE

To investigate the effect of bufalin on proliferation and apoptosis through ERK/RSK2 pathway in esophageal squamous cell carcinoma xenografts in nude mice.

METHODS

The subcutaneous xenograft model of esophageal cancer ECA109 cells in nude mice was established. The mice were divided into the model group, low-dose bufalin group, medium-dose bufalin group, high-dose bufalin group, PD98059 group and combination group to evaluate the effect of bufalin on the xenografts. The morphology of xenografts was observed by microscopy. The cell apoptosis index of xenografts was detected by TUNEL assay. The expression of ERK and RSK2 mRNA of human ECA109 cell transplantation tumor in nude mice was examined by real-time quantitative PCR. The protein levels of ERK, p-ERK, RSK2, p-RSK2, GSK3β, p-GSK3β, Bad and p-Bad in the xenografts were examined by Western blot and Immunohistochemistry.

RESULTS

The tumor size of nude mice in the model group, low-dose bufalin group (BL), medium -dose bufalin group (BM), high-dose bufalin group (BH), PD98059 group and combined therapy group (BP) was (1.758±0.181) cm(3,) (1.680±0.150) cm(3,) (1.285±0.134) cm(3,) (0.873±0.095) cm(3,) (0.815±0.108) cm(3) and (0.530±0.104) cm(3,) respectively. Histological examination showed that the xenografts of each group had varying degrees of necrosis, and the most extensive necrosis was observed in the BP group. The TUNEL assay showed that the cell apoptosis index of xenografts in the model, BL, BM, BH, PD98059 and BP groups was (6.0±0.6)%, (11.0±0.7)%, (19.1±0.9)%, (25.1±1.4)%, (20.0±1.2)% and (17.1±0.7)%, respectively, which is highest in the BH group. The real-time quantitative PCR results showed that the ΔCT values of ERK mRNA in the model, BL, BM, BH, PD98059 and BP groups were 0.270±0.084, 0.293±0.081, 0.596±0.224, 0.857±0.183, 0.868±0.187 and 1.313±0.282, respectively. The ΔCT values of RSK2 mRNA in the model, BL, BM, BH, PD98059 and BP groups were 0.340±0.062, 0.337±0.071, 0.642±0.226, 0.915±0.170, 0.923±0.176 and 1.413±0.269, respectively. The relative expression of ERK and RSK2 mRNA was gradually decreased. Western blot and immunohistochemistry results showed that the protein levels of ERK, RSK2 and Bad in each group were not significantly different (P>0.05). The protein levels of p-ERK in the model, BL, BM, BH, PD98059 and BP groups were 0.721±0.094, 0.695±0.095, 0.555±0.080, 0.388±0.052, 0.341±0.060, 0.235± 0.056, respectively. The median immunoreactivity scores of p-ERK in each group were 8, 8, 6, 4, 5 and 3. The protein levels of p-RSK2 in the model, BL, BM, BH, PD98059 and BP groups were 0.613±0.085, 0.612±0.084, 0.427±0.089, 0.305±0.056, 0.258±0.051, 0.158±0.058, respectively. The median immunoreactivity scores of p-RSK in each group were 8, 8, 5, 3, 3 and 1. The protein level of GSK3β in the model, BL, BM, BH, PD98059 and BP groups were increased gradually, while the protein level of p-GSK3β and p-Bad were decreased gradually.

CONCLUSIONS

Bufalin exerts significant inhibitory effect on the esophageal squamous cell carcinoma xenogragts in nude mice. Bufalin may suppress the growth of xenogragts in nude mice by down-regulating the level of ERK and RSK2 phosphorylation, inhibit the proliferation of xenogragts via inactivating GSK3β and promote apoptosis through down-regulation of p-Bad.

Probing water micro-solvation in proteins by water catalysed proton-transfer tautomerism

Scientists have made tremendous efforts to gain understanding of the water molecules in proteins via indirect measurements such as molecular dynamic simulation and/or probing the polarity of the local environment. Here we present a tryptophan analogue that exhibits remarkable water catalysed proton-transfer properties. The resulting multiple emissions provide unique fingerprints that can be exploited for direct sensing of a site-specific water environment in a protein without disrupting its native structure. Replacing tryptophan with the newly developed tryptophan analogue we sense different water environments surrounding the five tryptophans in human thromboxane A₂ synthase. This development may lead to future research to probe how water molecules affect the folding, structures and activities of proteins.

Characteristics of unrecognised bipolar disorder in patients treated for major depressive disorder in China: general versus psychiatric hospitals

OBJECTIVES

Bipolar disorder is often misdiagnosed as major depressive disorder. Such misdiagnosis partly depends on the type of treatment setting. This study compared general hospital psychiatric units with psychiatric hospitals in China with respect to basic demographic and clinical characteristics of patients with unrecognised bipolar disorder who are treated for major depressive disorder.

METHODS

Patients treated for major depressive disorder were consecutively examined in 13 health centres (6 general hospital psychiatric units and 7 psychiatric hospitals) in China. Their socio-demographic and clinical features were recorded using a standardised protocol and data collection procedure. The DSM-IV diagnoses were established using the Mini-International Neuropsychiatric Interview.

RESULTS

Of the 1487 patients included in the study, 309 (20.8%) were diagnosed with bipolar disorder. There was no significant difference between general hospital psychiatric units and psychiatric hospitals in the ratio of all types of unrecognised bipolar disorders (χ2 = 0.008, degrees of freedom = 1, p = 0.9) and bipolar II disorders (χ2 = 3.1, degrees of freedom = 1, p = 0.08). The proportions of unrecognised bipolar I disorders (χ2 = 4.1, degrees of freedom = 1, p = 0.04) differed significantly between the 2 types of study site. Multivariate analyses showed that patients with bipolar I disorders with more seasonal depressive episodes were more likely to receive treatment in general hospital psychiatric units (odds ratio = 3.3, 95% confidence interval = 1.1-9.8).

CONCLUSION

Patients with bipolar I disorders receiving treatment in general hospital psychiatric units had different clinical characteristics compared to their counterparts treated in psychiatric hospitals in China.

Longitudinal and transverse Hall resistivities in NaFe₁-xCoxAs single crystals with x = 0.022 and 0.0205: weak pinning and anomalous electrical transport properties

The in-plane longitudinal and Hall resistivities, ρxx and ρxy, of superconducting NaFe1-xCoxAs (NFCA) single crystals with x = 0.022 and 0.0205 in the mixed state and the normal state were measured to study the electrical transport properties in nearly optimum-doping iron-based superconductors. The resistivities under magnetic fields show thermally activated behavior and a power law magnetic field dependence of activation energy has been obtained. Due to the weak flux pinning, there is no sign reversal of Hall resistivities observed for NFCA with either x = 0.022 or 0.0205. The correlation between longitudinal and Hall resistivities shows that the scaling behavior of |ρxy| ∝ (ρxx)(β) with the exponent β ≈ 2.0 is in agreement with theoretical predictions for weak-pinning superconductors. Anisotropic upper critical fields and coherence lengths with an anisotropy ratio of γ ≈ 1.63 have been deduced. Furthermore, the normal-state transport properties show that the anomalies of the linear-T resistivity, the T(2)-dependent cotangent of the Hall angle, the linear-T-like Hall number, and the magnetoresistance, which can be scaled by the modified Kohler rule, are analogous to those observed on optimally doped high-Tc superconducting cuprates and other pnictides. The longitudinal resistivity can be understood within a widely accepted scenario of the spin density-wave quantum critical point, while the transverse resistivity requires some further explanation. It is suggested that all the transport anomalies should be simultaneously taken into account when developing theory.

Vitamin E facilitates the inactivation of the kinase Akt by the phosphatase PHLPP1

Vitamin E is a fat-soluble vitamin with antioxidant properties. Tocopherols are the predominant form of vitamin E found in the diet and in supplements and have garnered interest for their potential cancer therapeutic and preventive effects, such as the dephosphorylation of Akt, a serine/threonine kinase with a pivotal role in cell growth, survival, and metabolism. Dephosphorylation of Akt at Ser473 substantially reduces its catalytic activity and inhibits downstream signaling. We found that the mechanism by which α-tocopherol and γ-tocopherol facilitate this site-specific dephosphorylation of Akt was mediated through the pleckstrin homology (PH) domain-dependent recruitment of Akt and PHLPP1 (PH domain leucine-rich repeat protein phosphatase, isoform 1) to the plasma membrane. We structurally optimized these tocopherols to obtain derivatives with greater in vitro potency and in vivo tumor-suppressive activity in two prostate xenograft tumor models. Binding affinities for the PH domains of Akt and PHLPP1 were greater than for other PH domain-containing proteins, which may underlie the preferential recruitment of these proteins to membranes containing tocopherols. Molecular modeling revealed the structural determinants of the interaction with the PH domain of Akt that may inform strategies for continued structural optimization. By describing a mechanism by which tocopherols facilitate the dephosphorylation of Akt at Ser473, we provide insights into the mode of antitumor action of tocopherols and a rationale for the translational development of tocopherols into novel PH domain-targeted Akt inhibitors.

Identification of kazinol Q, a natural product from Formosan plants, as an inhibitor of DNA methyltransferase

DNA methylation plays a pivotal role in the epigenetic regulation of the transcription of a number of cancer-related genes, thereby representing an important target for cancer prevention and treatment. In our search for DNA methyltransferase (DNMT) inhibitors from Formosan plants, by screening against a library consisting of 12 structurally distinct natural products, we identified kazinol Q {4-[6-(1,1-dimethyl-allyl)-7-hydroxy-chroman-2-yl]-3,6-bis-(3-methyl-but-2-enyl)-benzene-1,2-diol} as an inhibitor of recombinant DNMT1 with IC50 of 7 μM. The effect of kazinol Q on DNMT inhibition was validated by its ability to reactivate the expression of a DNA methylation-silenced gene, E-cadherin, in MDA-MB-231 breast cancer cells. Moreover, kazinol Q suppressed the proliferation of MCF-7 breast and LNCaP prostate cancer cells, in part, through apoptosis induction. The role of DNMT1 inhibition in mediating kazinol Q's antiproliferative effect was supported by the protective effect of ectopic expression of DNMT1 on kazinol Q-induced cell death. Molecular modeling analysis suggests that kazinol Q inhibited DNMT activity by competing with cytosine binding, a mechanism similar to that described for (-)-epigallocatechin-3-gallate (EGCG). Relative to EGCG, kazinol Q exhibits several desirable features for drug development, including chemical stability and increased hydrophobicity, and might have therapeutic relevance to cancer treatment.

Experimental study on low-detection limit for immunomagnetic reduction assays by manipulating reagent entities

The low limit of detection (LLD) plays an important role in biomolecular assays, especially for early-stage assays. Biomolecular detections usually involve the use of two main elements: a reagent and an analyzer, which both greatly contribute to the LLD. In this work, the relationships among the LLD and reagent-related factors are investigated. The to-be-detected biomolecule is c-reactive protein (CRP) as an example. The assay method is immunomagnetic reduction (IMR). The components of reagent are Fe(3)O(4) magnetic nanoparticles bio-functionalized with antibodies against CRP, dispersed in pH-7.4 phosphate buffered saline solution. Several key factors of the reagent, such as particle concentration, volume ratio of reagent to sample, and particle size, are manipulated to optimize the LLD of detecting CRP.

Growth and properties of ZnO/Zn(1-x)MgxO core/shell nanoparticles

ZnO/Zn(0.9)Mg(0.1)O core/shell nanoparticles have been grown by employing metal cupferronate complex as precursors in organic solvents. ZnO cores are grown by quickly injecting their precursor at 250 degrees C while the shells are performed by slowly injecting their precursors at different temperatures. The grown nanoparticles are characterized by X-ray diffraction, photoluminescence microscopy, and transmission electron microscopy. The effects of the shell growth temperatures and precursor injecting rate are studied. Zn(0.9)Mg(0.1)O shells can epitaxially grow on ZnO cores when the shell growth temperature is lowered to 200 degrees C and the shell precursor is supplied slowly at a rate of 0.1 mmol/h. Increaseing shell supply rate or shell growth temperature results in homogenous growth of Zn(0.9)Mg(0.1)O nanoparticles. The shell growth can dramatically enhance core emission and cause a red shift on the core band edge emission.

Growth and properties of Zn(1-x)CdxO and Zn(1-x)CdxO/ZnO core/shell nanoparticles

Octylamine capped Zn(1-x)CdxO alloys and Zn(1-x)CdxO/ZnO core/shell nanoparticles have been grown by the thermal decomposing of zinc and cadmium cupferronates in organic solvents. Zn(1-x)CdxO alloys incorprated with different concentration of Cd have been grown by quickly injecting of their precursors at 200 degrees C. Zn(1-x)CdxO/ZnO core/shell nanoparticles are performed by slowly injecting of shell precursors at 180 degrees C. The prepared nanoparticles are characterized by X-ray diffraction, absorption spectrometer, Mirco-Raman spectrometer and transmission electron microscopy. The band gap of ZnCdO alloys shrinks linearly and the crystal lattice expands with an increase of Cd concentration. The growth of ZnO shells on ZnCdO cores enhances the core luminescence dramatically and results in a red shift in the absorption and emission of Zn(1-x)CdxO cores.

Targeting energy metabolic and oncogenic signaling pathways in triple-negative breast cancer by a novel adenosine monophosphate-activated protein kinase (AMPK) activator

The antitumor activities of the novel adenosine monophosphate-activated protein kinase (AMPK) activator, OSU-53, were assessed in in vitro and in vivo models of triple-negative breast cancer. OSU-53 directly stimulated recombinant AMPK kinase activity (EC(50), 0.3 μM) and inhibited the viability and clonogenic growth of MDA-MB-231 and MDA-MB-468 cells with equal potency (IC(50), 5 and 2 μM, respectively) despite lack of LKB1 expression in MDA-MB-231 cells. Nonmalignant MCF-10A cells, however, were unaffected. Beyond AMPK-mediated effects on mammalian target of rapamycin signaling and lipogenesis, OSU-53 also targeted multiple AMPK downstream pathways. Among these, the protein phosphatase 2A-dependent dephosphorylation of Akt is noteworthy because it circumvents the feedback activation of Akt that results from mammalian target of rapamycin inhibition. OSU-53 also modulated energy homeostasis by suppressing fatty acid biosynthesis and shifting the metabolism to oxidation by up-regulating the expression of key regulators of mitochondrial biogenesis, such as a peroxisome proliferator-activated receptor γ coactivator 1α and the transcription factor nuclear respiratory factor 1. Moreover, OSU-53 suppressed LPS-induced IL-6 production, thereby blocking subsequent Stat3 activation, and inhibited hypoxia-induced epithelial-mesenchymal transition in association with the silencing of hypoxia-inducible factor 1a and the E-cadherin repressor Snail. In MDA-MB-231 tumor-bearing mice, daily oral administration of OSU-53 (50 and 100 mg/kg) suppressed tumor growth by 47-49% and modulated relevant intratumoral biomarkers of drug activity. However, OSU-53 also induced protective autophagy that attenuated its antiproliferative potency. Accordingly, cotreatment with the autophagy inhibitor chloroquine increased the in vivo tumor-suppressive activity of OSU-53. OSU-53 is a potent, orally bioavailable AMPK activator that acts through a broad spectrum of antitumor activities.

In vivo and real-time measurement of magnetic nanoparticles distribution in animals by scanning SQUID biosusceptometry for biomedicine study

Magnetic nanoparticles have been widely applied to biomagnetism, such as drug deliver, magnetic labeling, and contrast agent for in vivo image, etc. To localize the distribution of these magnetic particles in living organism is the first important issue to confirm the effects of magnetic nanoparticles and also evaluate the possible untoward effects. In this study, a scanning high T(c) rf-SQUID superconducting quantum interference devices (SQUIDs) biosusceptometry, composed of static SQUID unit and scanning coil sets, is developed for biomedicine study with the advantages of easy operation and unshielded environment. The characteristics tests showed that the system had the low noise of 8 pT/Hz at 400 Hz and the high sensitivity with the minimum detectable magnetization around 4.5 × 10(-3) EMU at distance of 13 mm. A magnetic nanoparticle detection test, performed by ex vivo scanning of the magnetic fluids filled capillary under swine skin for simulation of blood vessels in living bodies, confirmed that the system is feasible for dynamic tracking of magnetic nanoparticles. Based on this result, we performed further studies in rats to clarify the dynamic distribution of magnetic nanoparticle in living organism for the pharmacokinetics analysis like drug delivers, and propose the possible physiological metabolism of intravenous magnetic nanoparticles.

Magnetically enhanced high-specificity virus detection using bio-activated magnetic nanoparticles with antibodies as labeling markers

This study describes magnetically driven suppression of cross-reactions among molecules. First, the magnetic nanoparticles are coated with bio-probes and dispersed in liquid. The bio-probes can then bind with homologous or heterologous bio-targets. When alternating-current (ac) magnetic fields are applied, magnetic nanoparticles rotate driven by ac magnetic fields. Thus, the bio-targets bound on the surface of magnetic nanoparticles experience a centrifugal force. The centrifugal force can be manipulated by adjusting the angular frequency of the rotating magnetic nanoparticles. The angular frequency is determined by the applied ac magnetic field frequency. Since the binding force for good binding is much higher than that of poor binding, frequency manipulation is needed for the centrifugal force to be higher than the poor-binding force but lower than the good-binding force. Therefore, poor binding which contributes to cross reactions between molecules can be suppressed efficiently by control of the ac magnetic field frequency.

Minimizing attrition bias: a longitudinal study of depressive symptoms in an elderly cohort

BACKGROUND

Attrition from mortality is common in longitudinal studies of the elderly. Ignoring the resulting non-response or missing data can bias study results.

METHODS

1260 elderly participants underwent biennial follow-up assessments over 10 years. Many missed one or more assessments over this period. We compared three statistical models to evaluate the impact of missing data on an analysis of depressive symptoms over time. The first analytic model (generalized mixed model) treated non-response as data missing at random. The other two models used shared parameter methods; each had different specifications for dropout but both jointly modeled both outcome and dropout through a common random effect.

RESULTS

The presence of depressive symptoms was associated with being female, having less education, functional impairment, using more prescription drugs, and taking antidepressant drugs. In all three models, the same variables were significantly associated with depression and in the same direction. However, the strength of the associations differed widely between the generalized mixed model and the shared parameter models. Although the two shared parameter models had different assumptions about the dropout process, they yielded similar estimates for the outcome. One model fitted the data better, and the other was computationally faster.

CONCLUSIONS

Dropout does not occur randomly in longitudinal studies of the elderly. Thus, simply ignoring it can yield biased results. Shared parameter models are a powerful, flexible, and easily implemented tool for analyzing longitudinal data while minimizing bias due to nonrandom attrition.

Thiazolidinediones mimic glucose starvation in facilitating Sp1 degradation through the up-regulation of beta-transducin repeat-containing protein

This study investigated the mechanism by which the transcription factor Sp1 is degraded in prostate cancer cells. We recently developed a thiazolidinedione derivative, (Z)-5-(4-hydroxy-3-trifluoromethylbenzylidene)-3-(1-methylcyclohexyl)-thiazolidine-2,4-dione (OSU-CG12), that induces Sp1 degradation in a manner paralleling that of glucose starvation. Based on our finding that thiazolidinediones suppress beta-catenin and cyclin D1 by up-regulating the E3 ligase SCF(beta-TrCP), we hypothesized that beta-transducin repeat-containing protein (beta-TrCP) targets Sp1 for proteasomal degradation in response to glucose starvation or OSU-CG12. Here we show that either treatment of LNCaP cells increased specific binding of Sp1 with beta-TrCP. This direct binding was confirmed by in vitro pull-down analysis with bacterially expressed beta-TrCP. Although ectopic expression of beta-TrCP enhanced the ability of OSU-CG12 to facilitate Sp1 degradation, suppression of endogenous beta-TrCP function by a dominant-negative mutant or small interfering RNA-mediated knockdown blocked OSU-CG12-facilitated Sp1 ubiquitination and/or degradation. Sp1 contains a C-terminal conventional DSG destruction box ((727)DSGAGS(732)) that mediates beta-TrCP recognition and encompasses a glycogen synthase kinase 3beta (GSK3beta) phosphorylation motif (SXXXS). Pharmacological and molecular genetic approaches and mutational analyses indicate that extracellular signal-regulated kinase-mediated phosphorylation of Thr739 and GSK3beta-mediated phosphorylation of Ser728 and Ser732 were critical for Sp1 degradation. The ability of OSU-CG12 to mimic glucose starvation to activate beta-TrCP-mediated Sp1 degradation has translational potential to foster novel strategies for cancer therapy.

Development of a sustained-release recombinant human growth hormone formulation

Recombinant human growth hormone (rhGH) therapy for short stature must be administered as a daily injection because of its poor bioavailability and short half-life. In the present study, a sustained-release formulation of rhGH (SR-rhGH), DA-3003, was prepared using double emulsion solvent evaporation with poly(D,L-lactide-co-glycolide) (PLGA), zinc oxide and hydroxypropyl-beta-cyclodextrin (HPCD) as the release modulator, stabilizer, and aggregation-prevention agent, respectively. After a single administration of DA-3003, the elevated concentration of rhGH in plasma was sustained for 14 days in rats and 28 days in monkeys. The plasma concentration of insulin-like growth factor-1 (IGF-I) and insulin-like growth factor binding protein-3 (IGFBP-3), which are pharmacodynamic markers of rhGH administration, increased and remained elevated for approximately 28 days in monkeys. Monkeys administered DA-3003 did not develop antibodies to hGH, indicating safety of the SR-rhGH formulation comparable to that observed with daily rhGH injections (Growtropin II). There were no significant differences in efficacy between Growtropin II (daily dose of 5 microg/animal for 14 days) and DA-3003 (weekly dose of 35 microg/animal for 14 days with a dosing interval of a week) in hypophysectomized rats, as assessed by changes in body weight and the width of the tibial growth plate. These results show that a sustained-release rhGH formulation, DA-3003, has the potential to be used safely and efficaciously in a weekly dosing regimen.

Effect of Inhibition of the Central Nucleus of the Amygdala and Drug Experience on the Regions Underlying Footshock-Induced Reinstatement of Morphine Seeking

This study assessed the effect of inhibition of the central nucleus of the amygdala (CeA) and drug experience on brain regions underlying footshock-induced reinstatement of morphine-seeking behaviour in rats. The difference in time spent in two chambers of a place-preference apparatus was used to measure morphine-conditioned place preference. Fos was measured as a marker of neuronal activation in the ventral bed nucleus of the stria terminalis (BNSTv) and ventral tegmental area (VTA). Footshock was found to enhance Fos expression in the BNSTv regardless of drug experience. In the VTA, morphine and footshock had an interactive effect on the increase in Fos expression. Inhibition of the CeA decreased Fos expression in the BNSTv regardless of drug experience, whereas in the VTA this effect only occurred in morphine-treated rats. These results suggest that drug experience has no differential effect on the BNSTv however morphine produces footshock sensitization in the VTA. CeA inhibition modulates the footshock-induced activity of these regions of the brain and attenuates reinstatement of drug seeking behaviour.

Ultra-highly sensitive and wash-free bio-detection of H5N1 virus by immunomagnetic reduction assays

A platform for assaying avian influenza H5N1 viruses that involves measuring the ac immunomagnetic reduction of a magnetic reagent mixed with a detected sample is developed. The magnetic reagent contained magnetic nanoparticles coated with antibodies. To achieve an ultra-high sensitivity assay, a system utilizing a high-transition-temperature superconducting quantum interference device was used to sense the immunomagnetic reduction of the reagents. The results confirmed the ultra-high sensitivity of the immunomagnetic reduction assay on H5N1.