Two new lactam derivatives from a Sphagneticola trilobata derived fungus Penicillium rubens PQJ-2.

A new bicyclic lactam derivatives penicilactam B (1) and a new monocyclic amide penicillamide D (2), along with four known compounds (3-6), were isolated from the fermentation broth of the derived fungus Penicillium rubens PQJ-2. Their structures and stereochemistry were elucidated by comprehensive spectroscopic analyses and quantum ECD calculations. All the compounds were evaluated for their antibacterial activities against Staphylococcus aureus subsp, Candida albicans, Escherichia coli and insecticidal activity against Helicoverpa armigera Hubner. Compounds 1-3 exhibited modest insecticidal activity against H. armigera Hubner.

Microglia-derived TNF-α inhibiting GABAergic neurons in the anterior lateral bed nucleus of the stria terminalis precipitates visceral hypersensitivity induced by colorectal distension in rats.

Irritable bowel syndrome (IBS) is a common and debilitating gastrointestinal disorder that is exacerbated by stress and characterized by abdominal pain. Although microglia in the CNS have been implicated as an important mediator of the stress response, the role of microglia and microglia-GABAergic neuron interactions in the limbic area, most notably BNST, in the development of colorectal hypersensitivity has not been determined. We established a neonatal colorectal distension-induced chronic visceral hyperalgesia model in rats. The results showed that the frequency of spontaneous discharges of alBNST GABAergic neurons and the expression of GAD65/67 were significantly decreased in rats with chronic visceral pain. Moreover, ablation of BNST GABAergic neurons significantly reduced the visceral pain threshold in normal rats. Meanwhile, the number of M1 proinflammatory microglia and the expression of the M1 proinflammatory microglia-derived cytokines IL-6 and TNF-α were increased in the alBNST of rats with chronic visceral pain. Furthermore, alBNST infusion of the microglial inhibitor minocycline or IL-6 and TNF-α neutralizing antibodies significantly increased the visceral pain threshold. The decreased frequency of spontaneous discharges of alBNST GABAergic neurons in rats with chronic visceral pain was mimicked by a bath perfusion of TNF-α, but not IL-6, and was abolished by a perfusion of the microglial inhibitor minocycline. In addition, the alBNST infusion of the microglial inhibitor minocycline upregulated the expression of GAD65/67. Moreover, ablation of BNST GABAergic neurons significantly decreased the visceral pain threshold in normal rats, which was not reversed by a subsequent infusion of the microglial inhibitor minocycline. Our findings revealed this microglia-GABAergic neuron circuit in the alBNST, and this microglia-driven disinhibitory mechanism is essential for brain and gut dysfunction in stressful condition, providing a novel potential target for treating patients with IBS presenting visceral pain that is worsened during episodes of stress.

Clinical Significance of MRI and Pathological Features of Giant Cell Tumor of Bone Boundary.

OBJECTIVE: To find new clues to reduce postoperative recurrence after intralesional curettage by studying MRI and pathological features of giant tumor of bone (GCTB) boundaries. METHODS: A retrospective study was performed in the departments of orthopaedic surgery and medical imaging at our hospitals from January 2006 to August 2016. A total of 16 GCTB patients confirmed by pathology were asked to participate in the present study. The age range was from 18 to 44 years (9 women and 7 men). All patients underwent MRI examination. All patients underwent en bloc resection and complete postoperative tumor segments were obtained. Five specimens were obtained randomly at the place of the segments where the GCTB boundary showed different types on MRI. Ordinary HE staining was used for all specimens and we measured the depth of local tumor cell infiltration (240 measurements). Results were expressed as means ± standard deviation. Statistical analyses were carried out with one-way ANOVA and the Student-Newman-Keuls test. P < 0.05 was considered statistically significant. The kappa test was used to analyze the degree of agreement of observers. RESULTS: A total of 16 patients (median age 30.56 years; range, 18-44 years) with GCTB (the number of distal femurs and proximal tibias was 9 and 7, respectively) were tested. The boundaries of all GCTB cases were composed of clear boundary, relatively clear boundary, and blurred boundary in different proportions on MRI. Based on continuous observation of all MRI, all boundaries were incomplete. The kappa value between two radiologists and two pathologists was 0.91 and 0.88, respectively. The average depth of local tumor cell infiltration in the clear boundary, relatively clear boundary, and blurred boundary groups was 0.42 ± 0.11 mm, 2.85 ± 0.21 mm, and 4.83 ± 0.12 mm, respectively. There was statistical difference among the three groups (F = 17.62, P < 0.05). There was also statistical difference between each of the two groups (q-value was 8.95, 14.28, and 5.21, respectively, P < 0.05). The depth of local tumor cell infiltration with blurred boundaries on MRI was the largest and the depth with clear boundaries was the smallest. CONCLUSION: The intralesional curettage boundaries need to be expanded on the basis of different types of boundaries provided by MRI.

Capillary electrophoresis-chemiluminescence detection for carcino-embryonic antigen based on aptamer/graphene oxide structure.

A new strategy is proposed for determination of carcino-embryonic antigen (CEA) based on aptamer/graphene oxide (Apt/GO) by capillary electrophoresis-chemiluminescence (CE-CL) detection system. CEA aptamer conjugated with horseradish peroxidase (HRP) firstly mixes with GO, and the CL will be quenched because the stack of HRP-Apt on GO leads to chemiluminescence resonance energy transfer (CRET). When CEA exists, the specific combination of HRP-Apt and CEA can form HRP-Apt-CEA complex, which dissociates from GO. Then, the CL catalyzed by HRP-Apt-CEA complex can be detected without any CRET, and the content of CEA can be estimated by the CL intensity. It has been proved that the interference issue resulted from free HRP-Apt is solved well by mixing GO firstly with HRP-Apt, which blocks the free HRP-Apt's CL signal due to CL quenching effect of GO; and the interference resulted from GO to CL is also solved by CE, then the sensitivity and accuracy can be greatly improved. Results also showed that the CL intensity had a linear relationship with the concentration of CEA in the range from 0.0654 to 6.54 ng/mL, and the limit of detection was approximately 4.8 pg/mL (S/N = 3). This proposed method with high specificity offers a new way for separation and determination of biomolecule, and has good potential in application of biochemistry and bioanalysis.

Carcino-embryonic antigen detection based on fluorescence resonance energy transfer between quantum dots and graphene oxide.

The mixture of graphene oxide (GO) and aptamer labeled fluorophore is widely used in developing fluorescent sensors for the analysis of biomolecules, according to the light signal 'off-on' procedure. Moreover, the laser-induced fluorescence-coupled affinity probe capillary electrophoresis (APCE) technique has been broadly applied for the separation of micromolecules. Here, a strategy is proposed for analysis of content of carcino-embryonic antigen (CEA) based on the combination of GO and quantum dots labeling aptamer (QD-aptamer) by capillary electrophoresis (CE). The method has three advantages: (i) combined with CE, only few samples are required and efficiency of separation is high, (ii) fluorescent detection can be carried out after separation of GO and fluorescence probe combined with targets by CE, while fluorescence detection sensitivity had been greatly improved, and (iii) the issues of APCE, including the effect of excess fluorescence probe and maximizing separation between analytes, could be solved by introducing GO. It has been proved that QD-aptamer-CEA complex can completely dissociate from GO. Results show that the fluorescence intensity has a linear relationship with the concentration of CEA in the range from 0.257 to 12.9 ng/mL, and the limit of detection is approximately 5 pg/mL (S/N=3). The proposed method with high specificity has been applied for the accurate analysis of content of CEA in patient׳s serum.

Facile synthesis of carbon nanotube-inorganic hybrid materials with improved photoactivity.

A facile method was used for the synthesis of CNTs@TiO2 nanocomposites using a simple apparatus at ambient pressure and temperature. CNTs@TiO2 exhibit core-shell structure without any interfacial adhesive layer on the CNT surface. The photodegradation of methyl orange suggests enhanced photoactivity of CNTs@TiO2 under UV light. The morphology, structure and composition of CNTs@TiO2 were also investigated.

A new strategy for the detection of adenosine triphosphate by aptamer/quantum dot biosensor based on chemiluminescence resonance energy transfer.

We designed an aptasensor for the detection of adenosine triphosphate (ATP) based on chemiluminescence resonance energy transfer (CRET). An adenosine aptamer was cut into two pieces of ssDNA, which were attached to quantum dots (QDs) and horse radish peroxidase (HRP), respectively. They could reassemble into specific structures in the presence of ATP and then decrease the distance of HRP and QDs. ATP detection can be easily realized according to the fluorescent intensity of QDs, which is excited by CRET between luminol and QDs. Results show that the concentration of ATP is linear relation with the fluorescent intensity of the peak of QDs emission and the linear range for the linear equation is from 50 µM to 231 µM and the detection limit was 185 nM. When the concentration of ATP was 2 mM, the efficiency of CRET is 13.6%. Good specificity for ATP had been demonstrated compared to thymidine triphosphate (TTP), cytidine triphosphate (CTP) and guanosine triphosphate (GTP), when 1 mM of each was added, respectively. This method needs no external light source and can avoid autofluorescence and photobleaching, and ATP can be detected selectively, specifically, and sensitively in a low micromolar range, which means that the strategy reported here can be applicable to the detection of several other target molecules.

Efficient CdPbS quantum dots-sensitized TiO2 photoelectrodes for solar cell applications.

CdPbS quantum dots-sensitized TiO2 photoelectrode was prepared using chemical bath codeposition technique by dipping TiO2 film into a 0.5 M Cd(NO3)2-Pb(NO3)2 solution (molar ratio 9:1) and a 0.5 M Na2S methanol solution. The CdPbS quantum dots have the size about 4 to 6 nm and distribute homogeneously in the TiO2 film. The as-prepared electrode showed improved absorption spectra. The assembled quantum dots-sensitized solar cell (QDSSC) yielded a power conversion efficiency (nu) of 1.88% and a short-circuit current of 15.28 mA/cm2 under AM 1.5 illumination of 100 mW/cm2, far outperformed the single PbS, CdS QDSSC and the nu increased 49.2% than coupled PbS/CdS QDSSC. The solar cell presented IPCE peak value of 45.7% and the effective photovoltaic range covers the visible region and near infrared region.

Relationship between traditional Chinese medicine syndrome differentiation and imaging characterization to the radiosensitivity of nasopharyngeal carcinoma.

BACKGROUND AND OBJECTIVE: Traditional Chinese medicine (TCM) is a well established and time-honored practice in China, employing syndrome differentiation as a basis for the treatment of disease. According to different TCM syndrome typing findings, combining modern medical methods with TCM approaches can improve the quality of life and comprehensive effect on patients with nasopharyngeal carcinoma (NPC). This study investigated the relationship between TCM syndrome typing and imaging characterization to radiosensitivity as to provide objective evidence for the integration of Chinese and modern medical approaches in the treatment of NPC. METHODS: Prior to treatment, TCM syndrome typing, computed tomography (CT) and magnetic resonance imaging (MRI) were performed on 147 patients pathologically classified with NPC. The status of tumor remission was radiologically evaluated at accumulated doses of 20 Gy, 40 Gy and 60 Gy, and at 3 months after completion of radiotherapy. Statistical results were analyzed by the Friedman and K-W test procedures. RESULTS: Prior to treatment, TCM syndrome typing of NPC included Lung Heat, Blood Stasis, Phlegm Congealment and Blood Stasis-Phlegm Congealment. Lung Heat typing accounted for the highest proportion at 34.7% (51/147), followed by Phlegm Congealment at 32.7% (48/147), Blood Stasis at 17.0% (25/147) and Blood Stasis-Phlegm Congealment at 15.7% (23/147). Radiological imaging demonstrated a higher incidence of cervical lymph node metastases in Phlegm Congealment and Blood Stasis-Phlegm Congealment types (P<0.05), while Blood Stasis and Blood Stasis-Phlegm Congealment types were more prone to skull base invasion (P<0.05). Residual tumor size was larger in Blood Stasis and Blood Stasis-Phlegm Congealment types than in Lung Heat and Phlegm Congealment types after 3 months of treatment (P<0.05). CONCLUSIONS: Different radiological manifestations were observed in TCM syndrome typed NPC patients, with lesser radiosensitivity demonstrated in the Blood Stasis and the Blood Stasis-Phlegm Congealment types relative to the Lung Heat and Phlegm Congealment types.

Synthesis and antitumor activity of novel 2',3'-dideoxy-2',3'-diethanethionucleosides bearing 1,2,3-triazole residues.

A series of novel 2',3'-dideoxy-2',3'-diethanethioribonucleosides and those modified with a triazole ring were prepared in excellent yields and their antitumor activity was evaluated. Nucleosides with a triazole ring, 16a-16c, showed significantly improved activity towards a broad range of tumor cell lines.