217 research outputs found

    2-Phenyl-1H-1,3,7,8-tetra­azacyclo­penta­[l]phenanthrene

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    There are two mol­ecules in the asymmetric unit of the title compound, C19H12N4, with dihedral angles of 2.41 (10) and 10.53 (12)° between the fused ring system and the pendant phenyl ring. In the crystal, mol­ecules are linked into chains by N—H⋯N hydrogen bonds and aromatic π–π stacking inter­actions [shortest centroid–centroid distance = 3.6176 (16) Å] complete the structure

    Corneal stromal acupuncture combined with amniotic membrane transplantation for treating bullous keratopathy

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    AIM: To investigate the clinical effect for treating bullous keratopathy(BK)by anterior corneal stromal acupuncture combined with amniotic membrane transplantation.<p>METHODS: Totally 35 patients(35 eyes)with bullous keratopathy were treated by corneal stromal acupuncture combined with amniotic membrane transplantation. All patients preoperative and postoperative underwent anterior segment OCT, corneal topography, corneal sensitivity and confocal microscopy. To observe postoperative ocular symptoms in patients with BK, recurrence of bulla, changes in corneal thickness, corneal sensitivity and changes in the organizational structure of the layers of the cornea.<p>RESULTS: Thirty-five were followed up for 6-18mo. The symptom of pain disappeared in 32 cases(91%)in the first day after operation and did not recur during follow-up. The symptom of pain relieved in 3 cases(9%)in the first day after operation and disappeared in 3 days. Corneal epithelium of 9 cases(26%)were all healed within 1wk, 21 cases(60%)were all healed within 2wk, and 5 cases(14%)were all healed within 3wk. Following up for 6-18mo, there was no recurrence of symptoms or bulla. A small amount of tiny bubbles in the surrounding area appeared in 2 cases after 3 and 4wk. All patients had no neovascularization, and had smooth corneal surface. The amnions of 30 cases(86%)were thinning after 2mo, partially dissolved and absorped, not seen with the naked eye after 3mo. Thirty-four cases(97%)had no changes in vision, one case(3%)was from the light to front of the manual. After 2mo, corneal sensation decreased in 30 cases(86%), corneal thickness increased from preoperative 788±35μm to 940±43μm. After 12mo, corneal thickness increased to 1060±27μm. Results of confocal microscopy: after 3mo, the number density of the trigeminal nerve fibers under corneal basement membrane reduced, shallow stromal cells became into fibrotic stroma, deep stroma was more loose, and cells swelled significantly. The number of endothelial cells reduced and form swelled more obviously compared with preoperatively.<p>CONCLUSION: Corneal acupuncture combined with amniotic membrane transplantation can effectively control the symptoms of BK, prevent the recurrence of BK, and especially it is a simple, safe and practical way for patients with poor visual function

    Modification of spherical SiO2 particles via electrolyte for high zeta potential and self-assembly of SiO2 photonic crystal

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    Spherical SiO2 particles were prepared by a novel co-precipitation process improved by electrolyte NaCl for charging and further self-assembled into photonic crystal by vertical deposition method. The obtained composites and their structures were characterized by scanning electron microscope (SEM) with X-Ray energy dispersive spectroscopy (EDS), Zetasizer, and UV-Vis spectrophotometer. SEM images indicated that the SiO2 particles were spherical and the average diameter of modified SiO2 particles was about 380 nm, larger than that of the unmodified ones (315 nm). Moreover, when the amount of NaCl was excessive (10 mg), bimodal diameter distribution SiO2 particles were obtained and the diameters were about 110 nm and 420 nm respectively. Compared with the unmodified SiO2 particles, EDS spectra of the modified ones showed an obvious characteristic-peak of Na element which proved that the Na element existed in the SiO2 particle. The results of Zetasizer revealed that the average Zeta potential of the modified SiO2 particles in ethanol was -56.6 mV, which was much higher than that of the unmodified ones (-48.7 mV). So the photonic crystal that self-assembled by the modified SiO2 particles possessed face-centred cubic structure with fewer defects. In addition, UV-Vis spectrophotometer showed that photonic band gap of the modified SiO2 photonic crystal had a red-shift and the absorption peak became narrower and higher

    Serum Peptidome Patterns of Colorectal Cancer Based on Magnetic Bead Separation and MALDI-TOF Mass Spectrometry Analysis

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    Background. Colorectal cancer (CRC) is one of the most common cancers in the world, identification of biomarkers for early detection of CRC represents a relevant target. The present study aims to determine serum peptidome patterns for CRC diagnosis. Methods. The present work focused on serum proteomic analysis of 32 health volunteers and 38 CRC by ClinProt Kit combined with mass spectrometry. This approach allowed the construction of a peptide patterns able to differentiate the studied populations. An independent group of serum (including 33 health volunteers, 34 CRC, 16 colorectal adenoma, 36 esophageal carcinoma, and 31 gastric carcinoma samples) was used to verify the diagnostic and differential diagnostic capability of the peptidome patterns blindly. An immunoassay method was used to determine serum CEA of CRC and controls. Results. A quick classifier algorithm was used to construct the peptidome patterns for identification of CRC from controls. Two of the identified peaks at m/z 741 and 7772 were used to construct peptidome patterns, achieving an accuracy close to 100% (>CEA, P<0.05). Furthermore, the peptidome patterns could differentiate validation group with high accuracy. Conclusions. These results suggest that the ClinProt Kit combined with mass spectrometry yields significantly higher accuracy for the diagnosis and differential diagnosis of CRC

    Hydroxysafflor Yellow A protects spinal cords from ischemia/reperfusion injury in rabbits

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    <p>Abstract</p> <p>Background</p> <p>Hydroxysafflor Yellow A (HSYA), which is one of the most important active ingredients of the Chinese herb <it>Carthamus tinctorius L</it>, is widely used in the treatment of cerebrovascular and cardiovascular diseases. However, the potential protective effect of HSYA in spinal cord ischemia/reperfusion (I/R) injury is still unknown.</p> <p>Methods</p> <p>Thirty-nine rabbits were randomly divided into three groups: sham group, I/R group and HSYA group. All animals were sacrificed after neurological evaluation with modified Tarlov criteria at the 48th hour after reperfusion, and the spinal cord segments (L4-6) were harvested for histopathological examination, biochemical analysis and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) staining.</p> <p>Results</p> <p>Neurological outcomes in HSYA group were slightly improved compared with those in I/R group. Histopathological analysis revealed that HSYA treatment attenuated I/R induced necrosis in spinal cords. Similarly, alleviated oxidative stress was indicated by decreased malondialdehyde (MDA) level and increased superoxide dismutase (SOD) activity after HSYA treatment. Moreover, as seen from TUNEL results, HSYA also protected neurons from I/R-induced apoptosis in rabbits.</p> <p>Conclusions</p> <p>These findings suggest that HSYA may protect spinal cords from I/R injury by alleviating oxidative stress and reducing neuronal apoptosis in rabbits.</p

    MiR-221 and miR-222 target PUMA to induce cell survival in glioblastoma

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    <p>Abstract</p> <p>Background</p> <p>MiR-221 and miR-222 (miR-221/222) are frequently up-regulated in various types of human malignancy including glioblastoma. Recent studies have reported that miR-221/222 regulate cell growth and cell cycle progression by targeting p27 and p57. However the underlying mechanism involved in cell survival modulation of miR-221/222 remains elusive.</p> <p>Results</p> <p>Here we showed that miR-221/222 inhibited cell apoptosis by targeting pro-apoptotic gene PUMA in human glioma cells. Enforced expression of miR-22/222 induced cell survival whereas knockdown of miR-221/222 rendered cells to apoptosis. Further, miR-221/222 reduced PUMA protein levels by targeting PUMA-3'UTR. Introducing PUMA cDNA without 3'UTR abrogated miR-221/222-induced cell survival. Notably, knockdown of miR-221/222 induces PUMA expression and cell apoptosis and considerably decreases tumor growth in xenograft model. Finally, there was an inverse relationship between PUMA and miR-221/222 expression in glioma tissues.</p> <p>Conclusion</p> <p>To our knowledge, these data indicate for the first time that miR-221/222 directly regulate apoptosis by targeting PUMA in glioblastoma and that miR-221/222 could be potential therapeutic targets for glioblastoma intervention.</p

    Characterization of a New M13 Metallopeptidase from Deep-Sea Shewanella sp. E525-6 and Mechanistic Insight into Its Catalysis

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    Bacterial extracellular peptidases are important for bacterial nutrition and organic nitrogen degradation in the ocean. While many peptidases of the M13 family from terrestrial animals and bacteria are studied, there has been no report on M13 peptidases from marine bacteria. Here, we characterized an M13 peptidase, PepS, from the deep-sea sedimentary strain Shewanella sp. E525-6, and investigated its substrate specificity and catalytic mechanism. The gene pepS cloned from strain E525-6 contains 2085 bp and encodes an M13 metallopeptidase. PepS was expressed in Escherichia coli and purified. Among the characterized M13 peptidases, PepS shares the highest sequence identity (47%) with Zmp1 from Mycobacterium tuberculosis, indicating that PepS is a new member of the M13 family. PepS had the highest activity at 30°C and pH 8.0. It retained 15% activity at 0°C. Its half life at 40°C was only 4 min. These properties indicate that PepS is a cold-adapted enzyme. The smallest substrate for PepS is pentapeptide, and it is probably unable to cleave peptides of more than 30 residues. PepS prefers to hydrolyze peptide bonds with P1’ hydrophobic residues. Structural and mutational analyses suggested that His531, His535 and Glu592 coordinate the catalytic zinc ion in PepS, Glu532 acts as a nucleophile, and His654 is probably involved in the transition state stabilization. Asp538 and Asp596 can stablize the orientations of His531 and His535, and Arg660 can stablize the orientation of Asp596. These results help in understanding marine bacterial peptidases and organic nitrogen degradation
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