Effects of RNA interference against aggrecanase 1 gene on extracellular matrix metabolism of cultured chondrocytes in vitro / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the effect of RNA interference (RNAi)-mediated aggrecanase-1 gene silencing on extracellular matrix metabolism of cultured rat costochondral chondrocytes.</p><p><b>METHODS</b>Rat costochondral chondrocyte monolayers were obtained by microdissection and digestion. The growth and morphological changes of the chondrocytes were observed after RNAi of aggrecanase-1 gene. The mRNA expression of aggrecanase-1 was detected by RT-PCR method, and aggrecan content was determined by Western blotting.</p><p><b>RESULTS</b>The specific inhibition of aggrecanase-1 by RNAi produced no adverse effect on the morphology and growth of the chondrocytes. The mRNA of aggrecanase-1 decreased and aggrecan content increased significantly after transfection of the chondrocytes.</p><p><b>CONCLUSION</b>Inhibition of aggrecanase-1 decreases aggrecan degradation in cultured rat chondrocytes. RNAi technique can be a useful means for studying extracellular matrix metabolism in the cartilage.</p>

The effect of aloesin on melanocytes in the pigmented skin equivalent model / 中华整形外科杂志

<p><b>OBJECTIVE</b>To observe the effect of aloesin, tea polyphenols, arbutin on melanocytes in the pigmented skin equivalent model.</p><p><b>METHODS</b>First, we constructed the pigmented skin equivalent model in vitro. And then we detected the effect of aloesin, tea polyphenols and arbutin on the cells' shape, tyrosinase activity and formation of melanin in the constructed pigmented skin equivalent.</p><p><b>RESULTS</b>Three depigmenting agents showed an inhibition effect on the tyrosinase activity of melanocytes and reduced significantly melanin content in the pigmented skin equivalent model, in which the tea polyphenols had the strongest effect, and then was the aloesin. But the tea polyphenols showed the strongest toxicity, while the aloesin and arbutin had a much lower toxicity.</p><p><b>CONCLUSIONS</b>All the three depigmenting agents showed a concentration dependent suppression effect on the tyrosinase activity and formation of melanin, in which the tea polyphenols was the strongest effect( P <0.05). Aoesin has a good suppression effect on the tyrosinase activity and formation of melanin, but has a much lower toxicity, which could be used as a safe depigmenting agent.</p>

Construction of an in vitro equivalent of the pigmented skin / 南方医科大学学报

<p><b>OBJECTIVE</b>To construct an in vitro equivalent of the pigmented skin using tissue engineering methods.</p><p><b>METHODS</b>Surgically removed foreskins was used as the source of keratinocytes and melanocytes harvested by routine tissue digestion. The fibroblasts were enriched by tissue block culture and seeded into the scaffold constructed using mouse tail collagens to construct the pigmented skin equivalent model. The general structure and the melanocyte distribution and growth status in this model were observed with HE staining and Fontana Masson staining. The ultrastructure of the constructed pigmented skin equivalent was observed by transmission electron microscope.</p><p><b>RESULTS AND CONCLUSION</b>The pigmented skin equivalent model was structurally intact, and allowed optimal cell growth. Fontana Masson staining identified in the basal layer numerous melanocytes in normal growth, and the constructed model was structurally similar to normal skin tissue, suggesting successful construction of the pigmented skin equivalent model.</p>

Apoptotic study on the effect of fluorine and selenium on the human hair follicle in vitro / 中华整形外科杂志

<p><b>OBJECTIVE</b>The aim of this study was to observe the human hair follicle apoptosis status affected by fluorine and the antagonism effect by selenium in vitro.</p><p><b>METHODS</b>The single hair follicles were separated and cultured, then they were added in different concentrations of sodium fluoride and sodium selenite. Chosen the appropriate concentrations, they were divided into 7 groups. The TUNEL was used to investigate the apoptotic cells of different parts. The morphous of hair follicles was observed consecutively and electron microscope was used.</p><p><b>RESULTS</b>We found that in 1 mmol/L and 10 mmol/L sodium fluoride groups, when the human hair follicles in vitro were cultured on the 5th day, the apoptotic cells of outer root sheath (ORS), dermal sheath and hair papilla, hair bulb were obviously increased. But 0.01 mmol/L sodium selenite weakened the toxicity of 1 mmol/L sodium fluoride at the outer root sheath and hair bulb (P < 0.05).</p><p><b>CONCLUSIONS</b>Different concentrations of sodium fluoride had different effect on the growth of human hair follicle in vitro which were cultured on 5th day. Sodium fluoride of certain concentration could accelerate the apoptosis of human hair follicle in vitro. Sodium selenite of certain concentration could act antagonism to the toxicity of sodium fluoride.</p>

The experimental study of lipo-sodium morrhuate promoting apoptosis of ECV-304 cells / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the effect of lipo-sodium morrhuate on ECV-304 cell line.</p><p><b>METHODS</b>The effect lipo-sodium morrhuate was evaluated by toxicology trial (MTT), electron microscope, DNA electrophoresis and flow cytometer.</p><p><b>RESULTS</b>The toxicology results showed, that the number of vital cells in lipo-sodium morrhuate group decreased slowly. The electron microscope exhibited apoptosis in the lipo-sodium morrhuate group. And there were typical DNA ladder in DNA electrophoresis and typical apoptosis peak in flow cytometer. The apoptosis rate was 22.23%.</p><p><b>CONCLUSIONS</b>Unlike the normal preparation of sodium morrhuate, lipo-sodium morrhuate could induce apoptosis of ECV-304 cell line.</p>

Compare the effect of lipo- and normal prepared Sodium Morrhuate on ECV-304 cell line / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To compare the effect of Sodium Morrhuate on ECV-304 between its lipo- and normal preparation.</p><p><b>METHODS</b>The ECV-304 cell line was supplemented with Sodium Morrhuate and lipo-Sodium Morrhuate in order, and the result on morphology (microscope, Giemsa Staining and electron microscope), cell activity (MTT), and flow cytometer between the two preparation were compared.</p><p><b>RESULTS</b>In normal preparation group, cell's edema occurred. Chromatin was like catkins. Tumefaction and degeneration of mitochondrion and endoplasmic reticulum appeared. In lipo-Sodium Morrhuate group, the membrane was creased and processus appeared. Chromatin aggregates to the membrane of nucleus was like crescent, and then broken. The apoptotic body was formed. MTT changes showed that the curve of the normal preparation group was steep and the change time was short relatively, which cues the vital cells decreased sharply. The curve of lipo-Sodium Morrhuate group was gentle and the change time was long relatively, which cues the vital cells decreased slowly. The flow cytometer showed that typical apoptosis peak appeared.</p><p><b>CONCLUSION</b>The normal preparation group shows an acute toxic effect on ECV-304 cell line, which result in a necrosis course, while lipo-Sodium Morrhuate shows a gradual releasing process, which may indicate a apoptosis course.</p>

Experimental study on induction of the normal human melanocytes apoptosis in vitro by cycloheximide and TNF-alpha / 中华整形外科杂志

<p><b>OBJECTIVE</b>To investigate the effects of cycloheximide and TNF-alpha on melanocyte (MC).</p><p><b>METHODS</b>Melanocyte apoptosis was studied with MTT, transmitting electron microscopy and fluorescence labeling of alive cells.</p><p><b>RESULTS</b>We added TNF-alpha and cycloheximide in melanocytes, and the typical apoptosis appeared 24 hours later, with chromatin condensation, nuclear pyknosis and apoptotic bodies formation. The results of cytometry showed the typical apoptotic peak.</p><p><b>CONCLUSION</b>TNF-alpha and cycloheximide together could inhibit MC proliferation and induce MC apoptosis.</p>

Stress distribution analysis of the surface of condyle during simulated fracture healing of the neck of condyle by miniplate osteosynthesis / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To find the reasons why patients always have temporomandibular disorders (TMD) after condylar fracture by analyzing the stress distribution change of the condylar surface whose subcondylar fracture ware fixed by miniplate during the whole healing process.</p><p><b>METHODS</b>Analyzing the stress distribution change of the condylar surface whose subcondylar fracture were fixed by miniplate during the whole healing process by three-dimension finite element method (3D FEM).</p><p><b>RESULTS</b>During the whole healing process of the fracture, the miniplate osteosynthesis was helpful to the biomechanics environment rehabilitation of the condylar local, but it still had difference with normal after fixing 12 weeks long.</p><p><b>CONCLUSION</b>The difference of stress distribution of condylar surface that fractured and fixed by miniplate with normal may be part of the reason of TMD after the subcondylar fracture miniplate osteosynthesis.</p>

The effects of aloesin and arbutin on cultured melanocytes in a synergetic method / 中华整形外科杂志

<p><b>OBJECTIVE</b>To study the effects of aloesin and arbutin on normal cultured human melanocytes in synergetic method.</p><p><b>METHODS</b>Building up the system of cultured human melanocytes. The cultured melanocytes in vitro were treated with the mixture of aloesin and arbutin. The cell viability and tyrosinase activity was measured by MTT assay, utilization of L-Dopa as the substrate respectively; melanin content was measured by image analysis system. Furthermore, the effects of the mixture on melanocytes were compared with that of aloesin and arbutin.</p><p><b>RESULTS</b>The mixture of aloesin and arbutin showed an inhibition on tyrosinase activity of human melanocytes and reduced significantly melanin content. Between the mixture and the single use of aloesin or arbutin, there is significant difference (P < 0.05). On the other hand, the mixture has little influence on melanocytes viability and there is negative significance.</p><p><b>CONCLUSION</b>The mixture of aloesin and arbutin can significantly inhibit the tyrosinase activity and melanogenesis of cultured human melanocytes. It showed the effects of aloesin and arbutin in a synergistic manner. It is worth to give farther study later.</p>

Effects of NGF and estrogens on human hair follicle in vitro / 中华整形外科杂志

<p><b>OBJECTIVE</b>To observe the effects of NGF, estrogens and minoxidil on the growth of human hair follicle in vitro.</p><p><b>METHODS</b>In a model of human hair follicle in vitro, the follicle was separately treated with the NGF, estrogens and minoxidil. The growth of the hair follicle was measured in length with an eyepiece micrometer. The effects of the NGF, estrogens and minoxidil were evaluated by measuring the rates of incorporation of 3H-TdR of DNA synthesis.</p><p><b>RESULTS</b>The growth of the human hair follicle was showing significantly faster in the 100 ng/ml NGF and 125 micrograms/ml minoxidil groups, compared with the control (P < 0.05), but the growth was significantly inhibited in the 0.5 microgram/ml 17 beta-E2 group (P < 0.05). There was no difference shown for the growth of the hair follicle in the group mixed with 100 ng/ml NGF and 0.5 microgram/ml 17 beta-E2 (P > 0.05). The rates of incorporation of 3H-TdR in the groups were shown that the results just correlated with the results of the above-mentioned method.</p><p><b>CONCLUSIONS</b>The 100 ng/ml NGF and 125 micrograms/ml minoxidil could increase the growth of human hair follicle while the 0.5 microgram/ml 17 beta-E2 could inhibit it. The 100 ng/ml NGF could neutralized the effect of the 0.5 microgram/ml 17 beta-E2.</p>