Construction and application of a new cell electrochemical detecting system based on the hyposmotic principle.

A new cell electrochemical detecting system has been constructed based on the hyposmotic principle, in which the electrochemical signals have been strengthened by about 109.75% for the signal at about +0.70 V and 532.94% for the signal at about +1.03 V. The electrochemical detection limits of the cells have been improved by one order of magnitude. The individual concentrations of intracellular purines have been obtained.

Detection of the cell viability and proliferation using two-signal electrochemical method.

Two electrochemical signals of the MCF-7 cell were simultaneously detected by using multiwall carbon nanotubes and room temperature ionic liquid composite film modified electrode. The signal at +0.726 V due to the oxidation of xanthine and guanine, was obviously improved. And the signal at +1.053 V due to the oxidation of hypoxanthine and adenine was found for the first time. This two-signal electrochemical method is credible to detect cell viability and proliferation.

Effectiveness and safety of repetitive transcranial magnetic stimulation for the treatment of morphine dependence: A retrospective study.

ABSTRACT: Morphine dependence (MD) is a very common complication because of the chronic morphine consumption. Studies suggest that repetitive transcranial magnetic stimulation (rTMS) can be used for the treatment of MD. However, there is still lacking evidence to support rTMS for MD. Thus, this retrospective study aimed to investigate the effectiveness and safety of rTMS for patients with MD.In this retrosepctive study, a total of 100 patients with MD were included, and they were divided into a rTMS group (n = 50), and a control group (n = 50). All patients in both groups received occupational therapy. In addition, patients in the rTMS group received rTMS. All patients in both groups received a total of 8 weeks treatment. The outcomes comprised of morphine craving intensity, depression, anxiety, and sleep quality, which were appraised by Visual Analogue Scale (VAS), Self-Rating Depression Scale (SDS), Self-Rating Anxiety Scale (SAS), and Pittsburgh Sleep Quality Index (PSQI), respectively. In addition, treatment-related adverse events were also considered for assessment.After 8 weeks treatment, patients in the rTMS group exerted better benefits in improving VAS (P < .01), SDS (P < .01), SAS (P < .01), and PSQI (P < .01), than patients in the control group. In addition, this study did not identify treatment-related adverse events in both groups.The findings of this study showed that rTMS treatment showed promising effectiveness on patients with MD. However, future studies should focus on warranting the present findings.

Voltammetric behavior of the MCF-7 cell cytoplasm and the effect of taxol on voltammetric response.

The aims of this study were to find the electroactive species in the human breast cancer (MCF-7) cell cytoplasm causing a voltammetric response of the cells and to establish a simple and rapid measurement method to obtain strong and direct electrochemical responses objectively reflecting the cell viability. Ultrasonication was carried out for the electrochemical detection. The presence of guanine and xanthine in the MCF-7 cell eluent secreted by the living cells and in the MCF-7 cell cytoplasm was verified by HPLC assay with a DAD system and chemometric method. The concentrations of guanine and xanthine in the MCF-7 cell cytoplasm and the voltammetric response of the MCF-7 cell cytoplasm had higher levels than those of intact cell suspensions. Additionally, taxol caused a decrease of the voltammetric response of the cytoplasm and concentrations of xanthine and guanine in the cytoplasm. Therefore, the origin of the voltammetric response of the MCF-7 cytoplasm was driven by the alteration of the levels of xanthine and guanine, which were related to the cell viability. Thus, the voltammetric response of the ultrasonicated MCF-7 cell suspension could be used to monitor the MCF-7 cell growth and to evaluate the effectiveness of antitumor drugs on tumor suppression.

[Diffraction enhanced imaging of condylar cartilage of osteoarthritic rats].

OBJECTIVE: To observe the images of early lesions of condylar cartilage of osteoarthritic rats in synchrotron radiation diffraction enhanced imaging (DEI). METHODS: The animal model of temporomandibular joint osteoarthrosis was established in rat following the method of partial resection of the joint disc. The changes of osteoarthritic condylar cartilage in different pathological stages were observed by DEI and compared with those in situ histopathological sections. RESULTS: With DEI, straight and orbicular lines were detected in condylar cartilage 45 to 60 days after discs resection. The lines were confirmed by histopathology to be collagen degradation and tiny fissure formation inside the cartilage. CONCLUSIONS: DEI is capable of imaging the early stages of pathological changes of excised condylar cartilage such as collagen degradation and tiny fissure formation, and this technique is of potential value to clinical application.

Bone morphogenetic protein 4 is involved in cusp formation in molar tooth germ of mice.

In order to clarify the role of BMP4 in the development of the tooth crown, we employed the antisense technique on molar tooth germs removed from the mandibles of embryonic 13.5-d-old mice. In the tooth germ explants incubated for 14 d with antisense oligodeoxynucleotide (AS-ODN) against Bmp4 (a) cusps were not formed, whereas dentin matrix was secreted in the whole region of the crown, (b) inner enamel epithelial (IEE) cells remained in the undifferentiated state in the occlusal region of the crown, though they differentiated in the proximal region (lateral surface region of tooth crown), and (c) insufficient growth of the dental papilla was observed. A 5-bromo-2'-deoxyuridine (BrdU) uptake experiment showed that, although a site-specific proliferation of IEE cells occurred in the occlusal region in the control explants, it was not found in the AS-ODN-treated explants. In the proximal region, however, the proliferation of IEE cells was detected evenly in all explants treated with or without AS-ODNs. These results suggest that AS-ODN against Bmp4 inhibited the differentiation and the site-specific proliferation of IEE cells in the occlusal region of molar tooth germs, resulting in the suppression of cusp formation. Our data thus suggest that BMP4 is involved in cusp formation and differentiation of ameloblasts in the occlusal region of molars.

Expression and role of Lhx8 in murine tooth development.

We examined the expression and possible functions of Lhx8, a member of the LIM-homeobox gene family, during tooth morphogenesis of the mouse. Lhx8 was expressed in the dental mesenchyme between the bud and early bell stage of the molar tooth germ. Tooth germ explants from embryonic day 12.5 mice treated for 5 to 7 days with antisense-oligodeoxynucleotides (AS-ODN) against Lhx8 showed a marked decrease in the number of mesenchymal cells. The explants treated with AS-ODN for 11 to 14 days were filled with a large number of undifferentiated epithelial cells and a limited number of undifferentiated mesenchymal cells, but did not contain a tooth germ. Treatment of explants with AS-ODN for 7 days suppressed the proliferation of dental mesenchymal cells and induced apoptosis; the latter was confirmed by histochemical and ultrastructural examinations. Moreover, the expression of Lhx6, Msx1, Msx2, Bmp4 and Gsc, which are also known to be involved in tooth morphogenesis, were suppressed after the application of AS-ODN against Lhx8 for 7 days. The present results suggest that Lhx8 plays an important role in the survival of mesenchymal cells of the tooth germ during development.