A Rh(ii)-catalyzed three-component reaction of 3-diazooxindoles with N,N-disubstituted anilines and glyoxylates for the synthesis of 3-aryl-3-substituted oxindoles

A simple and effective method for the synthesis of 3-aryl-3-substituted oxindole derivatives via a [Rh]-catalyzed three-component reaction of 3-diazooxindoles with N,N-disubstituted anilines and glyoxylates is developed. This transformation is proposed to proceed through an intermolecular aldol-type trapping of zwitterionic intermediates.

[Effect of continuous renal replacement therapy on the plasma concentration of imipenem in severe infection patients with acute renal injury]

OBJECTIVE

To investigate the extracorporeal clearance rate of imipenem in severe infection patients in the mode of continuous vena-venous hemofiltration (CVVH) during continuous renal replacement therapy (CRRT), in order to approach if the concentration of imipenem in plasma could achieve effective levels of anti-infection, and to explore the effect of time and anticoagulation measure on imipenem clearance during CRRT treatment.

METHODS

A prospective observational study was conducted. All adult severe infection patients complicating acute kidney injury (AKI) in the Department of Critical Care Medicine of the Fourth Hospital of Hebei Medical University from March 2013 to September 2014, who were prescribed imipenem as part of their required medical care, and CRRT for treatment of AKI were enrolled. 0.5 g doses of imipenem was administered intravenously every 6 hours or 8 hours according to random number table, and infused over 0.5 hour. The unfractionated heparin was used for anticoagulation in the patients without contraindications, and no anticoagulation strategy was used in the patients with high risk of bleeding. At 24 hours after first time of administration, postfilter venous blood and ultrafiltrate samples were collected at 0, 0.25, 0.5, 0.75, 1, 2, 5, 6, and 8 hours after imipenem administration. The concentration of imipenem in above samples was determined with liquid chromatography-mass spectrometer/mass spectrometer (LC-MS/MS).

RESULTS

A total of 25 patients were enrolled. Thirteen patients received imipenem intravenously every 6 hours, and 12 patients, every 8 hours. The anticoagulation was conducted with heparin in 13 cases, and 12 cases without anticoagulation. The intra-day precision, inter-day precision, matrix effect, and recovery rate in low, medium, and high concentration of plasma and ultrafiltrate, and the stability of samples under different conditions showed a good result, the error of accuracy was controlled in the range of ±15%. With the application of Prismaflex blood filtration system and AN69-M100 filter, under the mode with CVVH, the total clearance rate of imipenem was (8.874±2.828) L/h when the actual dose of replacement fluid was (31.63±1.48) mL×kg⁻¹×h⁻¹, the total CRRT clearance rate of imipenem in vitro was (2.211±0.539) L/h, which accounting for (30.1±15.7)% of the total drug clearance. In 6 hours interval dosage regimen, the percentages of the time > 4× minimum inhibitory concentration (MIC) at specific 4×MIC of 2, 4, 6, and 8 μg/mL of imipenem were more than 40% of the dosing interval. But in the 8 hours interval dosage regimen, when the level was above the 4×MIC of 4 μg/mL, maintaining time would drop below 40% of the dosing interval, with significant differences compared with that in 6 hours interval dosage regimen [4×MIC = 2 μg/mL: (60.84±20.25)% vs. (94.01±12.46)%, t = 4.977, P = 0.001; 4×MIC = 4 μg/mL: (39.85±15.88)% vs. (68.74±9.57)%, t = 5.562, P = 0.000; 4×MIC = 6 g/mL: (27.58±13.70)% vs. (53.97±8.36)%, t = 5.867, P = 0.000; 4×MIC = 8 μg/mL: ( 8.87±12.43)% vs. (43.48±7.83)%, t = 5.976, P = 0.000]. No significant change in sieving coefficient of imipenem was found within a short time (6 hours), which indicated that there was no effect of anticoagulation on clearance of imipenem by AN69-M100 filter, and no statistical significance was found with repeated measure analysis (F = 0.186, P > 0.05 ).

CONCLUSIONS

The clearance rate of imipenem is increased significantly in vitro under the mode of CVVH with the actual dose of replacement fluid was (31.63±1.48) mL×kg⁻¹×h⁻¹ in severe infective patients with severe sepsis complicating AKI, affecting the level of plasma drug concentration, need to adjust the dosage regimen. When the time of the dosing interval was shortened, the concentration of imipenem in patients' plasma could be increased significantly. In a short period of time, the sieving coefficient of imipenem through AN69 filter is not affected by anticoagulation measures and time cleaning efficiency will not decline.

Catalyst-Free Halogenation of α-Diazocarbonyl Compounds with N-Halosuccinimides: Synthesis of 3-Halooxindoles or Vinyl Halides

A novel catalyst-free halogenative cyclization of N-aryl diazoamides with N-halosuccinimides (NXS) is reported for the synthesis of 3-halooxindoles through a carbene-free mechanism. N-Aryl diazoamides reacted with NXS under mild and catalyst-free conditions to afford the corresponding 3-halooxindoles in good yields. This transformation is proposed to proceed through diazonium ion formation followed by intramolecular Friedel-Crafts alkylation.

Crosstalk between ACE2 and PLGF regulates vascular permeability during acute lung injury

Angiotensin converting enzyme 2 (ACE2) treatment suppresses the severity of acute lung injury (ALI), through antagonizing hydrolyzing angiotensin II (AngII) and the ALI-induced apoptosis of pulmonary endothelial cells. Nevertheless, the effects of ACE2 on vessel permeability and its relationship with placental growth factor (PLGF) remain ill-defined. In the current study, we examined the relationship between ACE2 and PLGF in ALI model in mice. We used a previously published bleomycin method to induce ALI in mice, and treated the mice with ACE2. We analyzed the levels of PLGF in these mice. The mouse lung vessel permeability was determined by a fluorescence pharmacokinetic assay following i.v. injection of 62.5 µg/kg Visudyne. PLGF pump or soluble Flt-1 (sFlt-1) pump was given to augment or suppress PLGF effects, respectively. The long-term effects on lung function were determined by measurement of lung resistance using methacholine. We found that ACE2 treatment did not alter PLGF levels in lung, but antagonized the effects of PLGF on increases of lung vessel permeability. Ectogenic PLGF abolished the antagonizing effects of ACE2 on the vessel permeability against PLGF. On the other hand, suppression of PLGF signaling mimicked the effects of ACE2 on the vessel permeability against PLGF. The suppression of vessel permeability resulted in improvement of lung function after ALI. Thus, ACE2 may antagonize the PLGF-mediated increases in lung vessel permeability during ALI, resulting in improvement of lung function after ALI.

Diagnostic value of bone-specific alkaline phosphatase in lung carcinoma patients with bone metastases: a meta-analysis

Aim and Backgrounds: The accurate diagnosis of lung carcinoma patients with bone metastases is crucial for therapy and the prevention of complications. We performed a systematic review and meta-analysis to evaluate the diagnostic value of serum bone-specific alkaline phosphatase (BALP) in lung carcinoma patients with bone metastases.

METHODS

Such databases as PubMed, Embase, Cochrane Library, Web of Science, Ovid, BioMed Central, Biosis previews and four Chinese databases (Chinese Biomedical Literature Database-disc (CBM), Chinese National Knowledge Infrastructure (CNKI), Technology of Chongqing (VIP) and Wan Fang DATA) were retrieved on computer, and the relevant journals were also manually searched to collect the trials on BALP in diagnosis of lung carcinoma patients with bone metastases. The meta-analysis was conducted by using Meta-Disc 1.4 software.

RESULTS

A total of 8 studies were included, and there were 848 lung carcinoma patients diagnosed by gold standard, patients were divided into two groups: 419 cases with bone metastases and 429 cases without bone metastases. The meta-analysis showed that, the pooled sensitivity (SEN), specificity (SPE), positive likelihood ratio (PLR), negative likelihood ratio (NLR) and diagnostic odds ratio (DOR) was 0.48 [95% CI (0.43 to 0.53)], 0.86 [95% CI (0.82 to 0.89)], 3.14 [95% CI (2.47 to 3.99)], 0.62 [95% CI (0.56 to 0.68)], 6.66 [95% CI (4.62 to 9.60)] respectively. And the AUC of SROC was 0.78, (Q*=0.72).

CONCLUSION

BALP has greater diagnostic value in detecting lung carcinoma patients with bone metastases. However, further large scale studies are required to confirm the predictive value.

Nonrigid Registration Regularized by Shape Information: Application to Atlas Construction of Cardiac CT Images

Cardiac atlases play an important role in the computer-aided diagnosis of cardiovascular diseases, in particular they need to deal with large and highly variable image datasets. In this paper, we propose a new nonrigid registration algorithm incorporating shape information, to produce comprehensive atlases. For one thing, the multiscale gradient orientation features of images are combined to form the construction of multifeature mutual information. Additionally, the shape information of multiple-objects in images is incorporated into the cost function for registration. We demonstrate the merits of the new registration algorithm on the 3D data sets of 15 patients. The experimental results show that the new registration algorithm can outperform the conventional intensity-based registration method. The obtained atlas can represent the cardiac structures more accurately.

Divergent synthesis of chiral heterocycles via sequencing of enantioselective three-component reactions and one-pot subsequent cyclization reactions

A highly efficient sequencing of catalytic asymmetric three-component reactions of alcohols, diazo compounds and aldimines/aldehydes with one-pot subsequent cyclization reactions was reported. The development of a robust and versatile Rh(ii)/Zr(iv)-BINOL co-catalytic system not only gives high diastereo- and enantioselective controls of the three-component reaction, but also shows excellent functionality tolerances that allow a wide range of functionalities to be pre-installed in each component and readily undergo one-pot subsequent cyclization reactions, thus providing rapid and diversity-oriented synthesis (DOS) of different types of chiral nitrogen- and/or oxygen-containing polyfunctional heterocycles.

DDR1 may play a key role in destruction of the blood-brain barrier after cerebral ischemia-reperfusion

Discoidin domain receptor 1 (DDR1) has been shown to mediate matrix metalloproteinase-9 (MMP-9) secretions and degrade all extracellular matrix compounds in mammalian tumor cells. We hypothesized that DDR1 expression will be elevated and the blood-brain barrier (BBB) will be damaged after focal cerebral ischemia in rats. Inhibiting DDR1 expression can alleviate BBB disruption and cerebral ischemic damage via down-regulation of MMP-9 expression and activity. To test our hypothesis, we injected specific DDR1 siRNA into ipsilateral ischemic lateral ventricles in a focal ischemic model. Our results showed that phospho-DDR1 expression increased after ischemia/reperfusion (I/R) injury (p < 0.01). Inactivation of DDR1 by specific siRNA caused a decrease in phospho-DDR1 and MMP-9 expression in the ischemic cortex, reduced stroke-induced infarct volume, and alleviated BBB disruption in rat brain following I/R injury (p < 0.01). Our results suggested that DDR1-siRNA attenuates phospho-DDR1 and MMP-9 upregulation, which was followed by a reduction in infarction and BBB disruption in the ischemic brain after I/R injury. DDR1 may represent a molecular target for the prevention of BBB disruption after cerebral I/R injury.

Estrogen alone or in combination with parathyroid hormone can decrease vertebral MEF2 and sclerostin expression and increase vertebral bone mass in ovariectomized rats

The study is about the regulatory effects of estrogen and parathyroid hormone (PTH) on sclerostin, a protein that inhibits the Wnt/β-catenin pathway. The results indicate that estrogen may down-regulate sclerostin expression and that estrogen displays synergistic action with PTH. These results provide a new perspective on the relationship between estrogen and bone.

PURPOSE

To investigate whether estrogen can down-regulate SOST and MEF2 (myocyte enhancer factor 2) expression and whether co-treatment with estrogen and PTH has a stronger effect on suppressing SOST than PTH applied alone in ovariectomized rats.

METHODS

Forty-three-month-old virgin female Sprague-Dawley (SD) rats were ovariectomized and divided into four groups (n = 10). Another ten age-matched rats received sham operations as controls. After allowing 8 weeks for the development of vertebral osteopenia, the rats were administered the drug intervention. For this intervention, the estrogen group was subcutaneously injected with 17β-estradiol at 25 μg/kg body weight, the PTH group was injected with 80 μg/kg synthetic human PTH (1-34), and the co-treatment group was concurrently treated with PTH and estrogen at the above dosage. The OVX group and sham group were treated with vehicle. The drug treatment was conducted for 12 weeks. After the lumbar spine bone mineral density (BMD) was measured, the rats were sacrificed, and the lumbar spine and blood were collected for qPCR, Western blot, immunohistochemistry and other tests.

RESULTS

Estrogen can down-regulate MEF2 and sclerostin expression, and co-treatment with estrogen and PTH has a stronger effect on suppressing MEF2 and SOST mRNA than PTH alone. The co-treatment group displayed slightly higher bone mass and biomechanical properties than the PTH group, but the differences were not significant.

CONCLUSIONS

Estrogen appears to be a regulator of sclerostin, and the effect may involve suppressing MEF2s. Combined treatment with PTH and estrogen is not more beneficial for vertebral bone mass and strength than treatment with PTH alone in ovariectomized rats.

Super-resolution imaging and tracking of protein-protein interactions in sub-diffraction cellular space

Imaging the location and dynamics of individual interacting protein pairs is essential but often difficult because of the fluorescent background from other paired and non-paired molecules, particularly in the sub-diffraction cellular space. Here we develop a new method combining bimolecular fluorescence complementation and photoactivated localization microscopy for super-resolution imaging and single-molecule tracking of specific protein–protein interactions. The method is used to study the interaction of two abundant proteins, MreB and EF-Tu, in Escherichia coli cells. The super-resolution imaging shows interesting distribution and domain sizes of interacting MreB–EF-Tu pairs as a subpopulation of total EF-Tu. The single-molecule tracking of MreB, EF-Tu and MreB–EF-Tu pairs reveals intriguing localization-dependent heterogonous dynamics and provides valuable insights to understanding the roles of MreB–EF-Tu interactions.

Protein–protein interactions are ubiquitous in cells and these contacts are crucial for a wide number of cellular processes. Here, the authors present a technique for the super-resolution imaging and tracking of protein–protein interactions in cells.