Three-dimensional bioprinting of artificial ovaries by an extrusion-based method using gelatin-methacryloyl bioink.

PURPOSE: The aim of this study was to design and fabricate a three-dimensional (3D) printed artificial ovary. METHODS: We first compared the printability of gelatin-methacryloyl (GelMA), alginate and GelMA-alginate bioinks, of which GelMA was selected for further investigation. The swelling properties, degradation kinetics and shape fidelity of GelMA scaffolds were characterized by equilibrium swelling/lyophilization, collagenase processing and micro-computed tomography evaluation. Commercial ovarian tumor cell lines (COV434, KGN, ID8) and primary culture ovarian somatic cells were utilized to perform cell-laden 3D printing, and the results were evaluated by live/dead assays and TUNEL detection. Murine ovarian follicles were seeded in the ovarian scaffold and their diameters were recorded every day. Finally, in vitro maturation was performed, and the ovulated oocytes were collected and observed. RESULTS: Our results indicated that GelMA was suitable for 3D printing fabrication. Its scaffolds performed well in terms of hygroscopicity, degradation kinetics and shape fidelity. The viability of ovarian somatic cells was lower than that of commercial cell lines, suggesting that extrusion-based 3D culture fabrication is not suitable for primary ovarian cells. Nevertheless, the GelMA-based 3D printing system provided an appropriate microenvironment for ovarian follicles, which successfully grew and ovulated in the scaffolds. Metaphase II oocytes were also observed after in vitro maturation. CONCLUSIONS: The GelMA-based 3D printing culture system is a viable alternative option for follicular growth, development and transfer. Accordingly, it shows promise for clinical application in the treatment of female endocrine and reproductive conditions.

[Effects of copper and cadmium ions on protective enzyme activity in Oncomelania hupensis].

OBJECTIVE: To evaluate the effects of Cu2+ and Cd2+ at different concentrations on superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) activity in Oncomelania hupensis. METHODS: Cu2+- and Cd2+-containing solutions were prepared at 7 concentrations, and O. hupensis snails were exposed to the solutions for 24 h, of 15 snails in each concentration. Then, the snail body was collected following removal of the snail shell and homogenated, and the SOD, CAT and POS activities were detected in the supernatants. RESULTS: With the increase of the Cu2+ concentration, the SOD activity appeared a rise followed by a reduction in O. hupensis snails, and the CTA activity appeared a decline-rise-decline tendency, while the POD activity showed a tendency towards rise followed by decline. With the increase of the Cd2+ concentration, the SOD activity appeared a rise followed by a reduction in O. hupensis snails, and the CTA activity appeared a decline- rise- decline tendency, while the POD activity showed a decline-rise-decline tendency. CONCLUSIONS: Exposure to Cu2+ and Cd2+ at high concentrations results in a decline in the activity of SOD, CAT and POD in O. hupensis at the same time.

Effect of irrigation on surface roughness and fatigue resistance of controlled memory wire nickel-titanium instruments.

AIM: To investigate the effect of irrigation on the surface roughness and fatigue resistance of HyFlex and M3 controlled memory (CM) wire nickel-titanium instruments. METHODOLOGY: Two new files of each brand were analysed by atomic force microscopy (AFM). Then, the instruments were dynamically immersed in either 5.25% sodium hypochlorite (NaOCl) or 17% ethylene diamine tetraacetic acid (EDTA) solution for 10 min, followed by AFM analysis. The roughness average (Ra) and root mean square (RMS) values were analysed statistically using an independent sample t-test. Then, 36 files of each brand were randomly assigned to three groups (n = 12). Group 1 (the control group) was composed of new instruments. Groups 2 and 3 were dynamically immersed in 5.25% NaOCl and 17% EDTA solutions for 10 min, respectively. The number of rotations to failure for various groups was analysed using the one-way analysis of variance software. RESULTS: For M3 files, the Ra and RMS values significantly increased (P < 0.05) after the immersion. For the HyFlex file, the Ra and RMS values significantly increased (P < 0.05) only in EDTA, but not (P > 0.05) NaOCl. The resistance to cyclic fatigue of both HyFlex and M3 files did not significantly decrease (P > 0.05) by immersing in 5.25% NaOCl and 17% EDTA solutions. CONCLUSIONS: Except the HyFlex files immersed in NaOCl, the surface roughness of other files exposed to irrigants increased. However, a change in the surface tomography of CM wire instruments caused by contact with irrigants for 10 min did not trigger a decrease in cyclic fatigue resistance.

Apocynin improves outcome in experimental stroke with a narrow dose range.

Inflammation following ischemic stroke is known to contribute to injury. NADPH oxidase (NOX) is a major enzyme system originally studied in immune cells that leads to superoxide (O.*) generation. Apocynin is a NOX inhibitor that has been studied as a potential treatment in experimental stroke. Here we explored the effect of different doses of apocynin in a mouse model of 2 h transient middle cerebral artery occlusion (tMCAO) followed by 22 h reperfusion. Apocynin, given i.v. at a dose of 2.5 mg/kg 30 min before reperfusion, improved neurological function (P<0.01), reduced infarct volume (P<0.05), and reduced the incidence of cerebral hemorrhage (P<0.05), but not at higher doses of 3.75 and 5 mg/kg, where it actually increased brain hemorrhage. Apocynin also tended to reduce mortality at the lower dose, but not at higher doses. Using hydroethine fluorescence to delineate O.* in the brain, neurons and some microglia/macrophages, but not vascular endothelial cells were found to contain O.*. Apocynin at protective doses markedly prevented ischemia-induced increases in O.*. Our data suggested that apocynin can protect against experimental stroke, but with a narrow therapeutic window.

Multiple pleural nodules without effusion--a rare presentation of tuberculous pleurisy.

We report a rare case of tuberculous pleurisy presenting with multiple pleural nodules without associated effusion or parenchymal lung lesions. A 62-year-old man had multiple discrete pleural nodules in the right hemithorax on chest radiography without any clinical symptoms. Thoracoscopic biopsy of the pleural nodules revealed a caseous granuloma with acid-fast bacilli. The patient received antituberculous therapy, with resolution of tuberculomas on chest film within 2 months. To our knowledge, only two similar cases have been previously reported in the English literature, and our observation should lead to broadening of the spectrum of the differential diagnosis of multiple pleural nodules.