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find Keyword "toxicity" 45 results
  • NEW POROUS β-TRICALCIUM PHOSPHATE AS SCAFFOLD FOR BONE TISSUE ENGINEERING

    Objective To investigate the feasibility of a new kind of porous β tricalcium phosphate (β-TCP) as a scaffold for the bone tissue engineering Methods The inverted phase contrast microscope was used to observe the growth of the marrow mesenchymal stem cells (MSCs) in the experimentalgroup and the control group at 10 days.In the experimental group, the MSCs were cultured with β-TCP(3 mm×3 mm×3 mm) in the 24-hole cultivation board, and in the control to control group, only MSCs were cultivated. The scanning electron microscope was used to observe growth of MSCs at 6 days. Cultivated with β-TCP at 3, 6, 9, 12 days, the MTT assay was used to judge the biocompatibility. The cytotoxicity was analyzed with the method that used the different density(100%, 50%, 10%, 1%,0%) leaching liquor gained from β-TCP to raise MSCs. MSCs were induced into the osteoblasts and were mixed with β-TCP, and the composite was used to repair a large radius bone defect in the rabbit. The specimens were made at 2,6,12 weeks. The histology imageology, and the radionuclide bone scan were used to analyze the bone formation. Results Some MSCs had a good adherence 4 hours after MSCs were inoculated and had a complete adherence at 12 hours. The cells were shaped like polyangle, spindle or converge monolayer after 8-10 days. The cells in the two groups had no difference. The cell adhesion was good, when observed by the inverted phase contrast microscope and the scanning electron microscope at 6 days. MTT showed that the absorbance (A)was not statistically different between the experimental group and the control group (P>0.05); the different density leaching liquor had no cytotoxicity at the different time points. Histology, X-ray, and CT tomograph showed that itcould repair the large radius bone defect in the rabbit and its in vivo degradationrate was the same as the bone formation rate. Conclusion The new porous β-TCP has a unique three dimensional (3D) stereochemical structure and superordinary physicochemical property, and so it is a good scaffold for the bone tissue engineering.

    Release date:2016-09-01 09:20 Export PDF Favorites Scan
  • Histological study of haw drink compound in protecting against experimental carbon disulfide toxic damage of relina

    Purpose To investigate the protective effect ofldquo;haw drink compoundrdquo;against carbon disulfide (CS2)toxic retinal damage. Methods Thirty healthy white adult New Zealand rabbits were divided at random into 3 groups:the normal control group,the exposure control group and the treatment group.The experimental rabbits were contaminated by inhaling CS2 for 3 continuoues hours in 6 consecutive days in a week for totaly 3 weeks.The rabbits in the treatment group were given haw drink compound before containation.After 3 weeks of the experiment,the retinal tissues of the rabbits were examined with light microscope and transmissing electronmicroscope(TEM). Results The ultrastructures of the retinal tissues of the exposure control group were more abnormal than those of the treatment group and the normal control group.TEM showed that every layer cell of the retinal in the exposure control group showed apparent degenerative changes ,but that in the treatment group showed apparent degenerative changes,but that in the treatment group was nomal.The light microscpic picture showed that the inner segments and the outer segments of photoreceptors construction were destroyed,the nerve fiber layer was loose and ganglion celles vacuolated in the retinat of the exposure control group.TEM showed that The photorecepter synapses were vacuolated,the postsynaptic space became wider and the synaptic sticks disappered. Conclusion How drink compound can improve the tolerance to CS2 toxicity in inducing the retinal damage of rabbits. (Chin J Ocul Fundus Dis, 1999, 15: )

    Release date:2016-09-02 06:07 Export PDF Favorites Scan
  • The effect of intravitreal injection with ciproflaxacin on retina

    ObjectiveTo evaluate the security of intravitreal injection with ciproflaxacin to retina.MethodsTweenty-four rabbits were randomly divided into 4 groups with 6 rabbits in each group. 0.1 ml ciproflaxacin in doses of 2 500,5 000,and 10 000 μg was intravitreally injected into the rabbits eyes, retrospectively. And 0.1 ml saline solution was injected into the vitreous body of the rats in the control group. Indirect microscope, light microscope and electroretinogram (ERG) were used to observe the changes of ocular fundus.ResultsNormal results of light microscopy and ultrastructure were found in 250 μg and 500 μg groups; irregularly arranged outer and inner nuclear layers, dropsical or even lost ganglion cells, and ultrastructural changes were in 1 000 μg group. There was no apparent difference of ERG′s a and b amplitudes before and after intravitreal injection with ciproflaxacin in each group.ConclusionIntravitreal injection with ciproflaxacin is safe, and 500 μg or less is the secure dosage in rabbits' eyes. (Chin J Ocul Fundus Dis, 2005,21:180-182)

    Release date:2016-09-02 05:52 Export PDF Favorites Scan
  • EXPERIMENTAL RETINAL PHOTIC INJURY

    An experimental model of retinal acute photic injury was developed in Wister rats. Aninmls were exposed to white light in intensity of 20 000 lux under general anesthesia for 1 hr. Two rats were sacrificed at 24, 48hr, day 7, 14,21,28,35 after liht exposure respectively. The histopathologic study showed that the retinal acute photic injury initiated in the outer seSment characterized by disorganization and loss of the outer segment at the early stage, and then the inner segment and RPE were involved. The decrease of the thickness of the outer nuclear layer was seen in a few of our cases. Some of our samples showed recovery of the outer and inner segment from the light damage of certian degrees 2 or 3 weeks after light exposure, but others did not. One sample from 5 weeks after light exposure demonstrated that the outer nuclear layer, the outer and inner segment completely lost. Thc inflammatory responses were not observed in all of our samples inplicating that the retinal acute photic damage is a degeneration process. (Chin J Ocul Fundus Dis,1994,10:84-85)

    Release date:2016-09-02 06:34 Export PDF Favorites Scan
  • Experimental tests of ophthalmic drugs and related issues

    Release date:2016-09-02 05:46 Export PDF Favorites Scan
  • Preliminary study of the damage effects of staphylococcus aureus exotoxins and neutrophils on retinal pigment epithelium cells

    Objective To evaluate the toxic effects of staphylococcus aureus exotoxins and neutrophils on retinal pigment epithelium (RPE) cells (RPEC). Methods An in-vitro model of bacteroidal endophthalmitis was established by co-culturing of human RPE cell line D407 and human peripheral blood neutrophils in the present of staphylococcus aureus exotoxins ATCC29213. The level of lactate dehydrogenase hydroxide(LDH)in the cuture supernant was measured, and the viability of RPE was evlauated by flow cytometry and Hoechst 33342/Propidium Iodide(PI)staining. Results When RPE cells were cultured with the exotoxin ATCC29213, the LDH level and necrotic RPE cells were positive proportional to the dosage of exotoxin, but only 250mu;l or 500mu;l of ATCC29213 had a statistical significant effect. When RPE cells were co-cultured with neutrophils in the present of ATCC29213 for 6 hours, 100mu;l of ATCC29213 already had a statistical significant effect on LDH level and necrotic RPEC, and the effect was proportional to the amount of neutrophils in the culture. Conclusion Both staphylococcus aureus exotoxins and neutrophils can damage the RPEC by inducing necrosis, and their function had synergetic effect.

    Release date:2016-09-02 05:46 Export PDF Favorites Scan
  • Research progress on financial toxicity in patients with heart failure

    Heart failure is a progressive disease with high readmission rate and long treatment duration, which impose a heavy financial burden on patients and their families. The resulting financial toxicity can also affect the health outcomes of patients. This article provides an in-depth analysis of the concept, evaluation tools, research status, hazards, influencing factors, and coping strategies of financial toxicity in patients with heart failure. Suggestions are put forward for the development of evaluation tools and the improvement of coping strategies for financial toxicity, aiming to provide a reference for the development of more scientific and effective systematic intervention strategies.

    Release date:2024-10-25 01:48 Export PDF Favorites Scan
  • Cytotoxicity in Vitro of a Noval Ni-free ZrCuFeAlAg Bulk Metallic Glass

    This paper is to evaluate the biocompatibility and cytotoxicity of a new Ni-free Zr-based bulk metallic glass (BMG), Zr60.14Cu22.31Fe4.85Al9.7Ag3, by comparing it with conventional Ti6Al4V alloy. According to ISO 10993-5:1999 and GB/T 16886.5-1997 standards, Zr60.14Cu22.31Fe4.85Al9.7Ag3, pure Zr and Ti6Al4V materials were extracted with surface area of sample/volume of medium ratio being 1 cm2/mL and 0.5 cm2/mL, respectively. The viabilities of MG-63 cells (Human osteosarcoma cell line) cultured in the BMG medium extracts for 1, 3 and 5 days were determined by CCK-8 assay. The cellular morphology of MG-63 cells cultured on the surface of samples for 3 days was tested through laser scanning confocal microscopy (LSCM) and scanning electron microscopy (SEM). The relative growth rate (RGR) of MG-63 cells cultured in Zr60.14Cu22.31 Fe4.85 Al9.7Ag3 and pure Zr were both more than 85%, indicating that the cytotoxicity of BMG was relatively low and met the national biomedical material eligibility standard. There was insignificant difference in the morphology of MG-63 cells cultured in the BMG medium extracts and the control group through LSCM and SEM, which showed the BMG had excellent biological compatibility. The Zr-based bulk metallic glass Zr60.14Cu22.31Fe4.85Al9.7Ag3 and the conventional Ti6Al4V alloy both had no obvious cytotoxicity to MG-63 cells. These results provided evidence that the new Zr-based bulk metallic glass could be potential replacement material for the orthopedic surgical implant.

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  • Late toxicities of the vital organs at risk after intensity-modulated radiotherapy for nasopharyngeal carcinoma

    Nasopharyngeal carcinoma (NPC) is rather common in Southeast Asia and Southern China. The standard treatment for NPC is intensity-modulated radiotherapy (IMRT). A large number of the NPC survivors benefit from the IMRT, while some suffer from the late toxicities which can be life-threatening or significantly erode the patients’ quality of life and functional status, especially in the locally advanced NPC. Nowadays the late radiotherapy-related toxicities have been the most important concern for the radiotherapists and patients, who look forward to the better long-term tumor local control and overall survival. Therefore, we carried out a review about the late radiotherapy-related toxicities of the vital organs at risk after IMRT for NPC patients.

    Release date:2018-04-23 05:00 Export PDF Favorites Scan
  • Effect of intravitreous injection with triamcinolone acetonide on retina

    ObjectiveTo investigate the effect of triamcinolone acetonide (TA) with different dosage and excipient on retina.MethodsThirty-two purebred New Zealand white rabbits randomly divided into 4 groups underwent intravitreous injection with TA. Group 1:4 mg TA without excipient; group 2:25 mg TA without excipient; group 3:4 mg TA with excipient; group 4:25 mg TA with excipient. Electroretinography (ERG) was performed on each rabbit before intravitreal injection, 1 week, 1 and 2 months after the injection. All the animals were killed and the eyeballs were extirpated 2 months after the injection, and pathological examinations including light and electron microscopy were performed.ResultsNo significant difference was found in the latent period of ERG at the points of time before and after the injection in all the groups, but the amplitudes of ERG waves was lower in groups containing excipient than that before the treatment (Plt; 0.01). The results of light and electron microscopy showed damages of tissue or structures of retina in various degrees in groups containing excipient.ConclusionIntravitreous injection of TA with the dosage of ≤25 mg without excipient does no harm to the retinal configuration and function, and excipient may lead to the change of retinal configuration and function.(Chin J Ocul Fundus Dis, 2005,21:229-232)

    Release date:2016-09-02 05:52 Export PDF Favorites Scan
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