Expression of periodontal ligament-associated protein-1 in normal periodontal tissues and cells in rat / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To examine the expression of periodontal ligament-associated protein-1 (PLAP-1) in the periodontal tissues and periodontal ligament cells (PDLC).</p><p><b>METHODS</b>The PLAP-1 expression in normal periodontal tissue was examined by immunohistochemistry. The protein expression and mRNA transcription of PLAP-1 in PDLC were investigated by immunocytochemistry and reverse transcription-polymerase chain reaction.</p><p><b>RESULTS</b>PLAP-1 was expressed in periodontium but not in cementum, alveolar bone and gingival tissues. PLAP-1 expression was observed in cell plasma, but not in nuclei. There was a 350 bp electrophoresis band representing PLAP-1 mRNA.</p><p><b>CONCLUSIONS</b>PLAP-1 may play a role in physiology of periodontal tissues and cells in normal adult rats.</p>

Quantitative detection of human cytomegalovirus in aggressive and chronic periodontitis lesions / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To establish a quantitative real-time PCR assay for the detection of human cytomegalovirus (HCMV) DNA load in subgingival specimens from the patients with aggressive and chronic periodontitis, and to investigate the relationship between HCMV infection and the periodontal status.</p><p><b>METHODS</b>A total of 114 subgingival plaque specimens were taken from 18 subjects with aggressive priodontiti (AgP), 24 subjects with chronic periodontitis (CP) and 15 healthy control subjects. Standard quantification was performed with recombinant plasmid containing a conserved fragment of HCMV. The SYBR Green I fluorescent quantitative real-time PCR assay was established based on positive plasmid. HCMV DNA load in the specimens were detected with quantitative real-time PCR based on SYBR Green I fluorescence.</p><p><b>RESULTS</b>HCMV were detected in 58.3% of AgP sites and 41.7% of CP sites, however, only 6.7% of periodontally-healthy sites were HCMV positive. The detection rate of HCMV in periodontitis lesions was significantly higher than in periodontal health (P < 0.01). High copy-counts more than 10(4) of HCMV were detected in 33.3% of AgP sites, which were significantly higher than in CP sites (10.4%) (P < 0.05).</p><p><b>CONCLUSION</b>Subgingival infection with HCMV is closely associated with periodontitis. Active HCMV infection may be related to the rapid tissue destruction of AgP.</p>

Effects of high mobility group box 1 in activating periodontal ligament fibroblasts to express cytokine / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the influence of high mobility group box 1 (HMGB1) on the expression of interleukin 6 (IL-6), receptor activator of nuclear factor-kappa B ligand (RANKL) and osteoprotegerin (OPG) on periodontal ligament fibroblasts.</p><p><b>METHODS</b>Human periodontal ligament fibroblasts were stimulated with HMGB1 at concentrations of 10, 30, and 100 ng x mL(-1) for 24 h. RT-PCR and Western blot analysis were performed to check mRNA and protein expression of IL-6, RANKL and OPG on the cells.</p><p><b>RESULTS</b>The ratio of RANKL/OPG was increased at both mRNA and protein level after HMGB1 stimulation at 10, 30, 100 ng x mL(-1). Inflammatory cytokine IL-6 was upregulated by HMGB1 at the concentration of 100 ng x mL(-1).</p><p><b>CONCLUSION</b>Increased ratio of RANKL/OPG and IL-6 on periodontal ligament fibroblasts suggests that HMGB1 might play a role in the pathogenesis and progression of periodontal disease.</p>

Levels of inflammation cytokines in patients with coronary heart disease and periodontal disease / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To determine the level of high-density lipoprotein cholesterol (HDL-C), serum C-reactive protein (CRP) and inflammation cytokines and investigate the concentration between periodontal disease and coronary heart disease (CHD).</p><p><b>METHODS</b>Sixty-six patients with CHD and chronic periodontitis [(C+P) group], forty-four with only CHD (C group), fifty-six with only chronic periodontitis (C group), and forty-three healthy controls (H group) were included in this study. The diagnosis of chronic periodontitis and CHD was based on accepted clinical criteria. Serum levels of HDL-C, CRP, IL-6, tumor necrosis factor (TNF)-alpha and IL-1beta were tested in all patients and controls.</p><p><b>RESULTS</b>The periodontal conditions of these four groups were significantly different (P<0.05). The clinical periodontal parameters [probing depth (PD), attachment loss (AL), and bleeding on probing (BOP)] in patients with (C+P) group, P group, C group and H group were [(4.55+/-0.85) mm, (3.78+/-0.34) mm, 69.6%], [(4.06+/-0.61) mm, (3.05+/-0.44) mm, 63.6%], [(1.85+/-0.67) mm, (1.26+/-0.39) mm, 20.5%], [(1.12+/-0.33) mm, (0.42+/-0.83) mm, 4.6%], respectively. The levels of HDL-C in H group, C group, P group and (C+P) group were (1.42+/-0.21), (1.22+/-0.18), (1.24+/-0.21) and (1.04+/-0.22) mmol/L, respectively. T compare with other three groups, the level of HDL-C in (C+P) group is the lowest. The levels of CRP, IL-6, TNF-alpha and IL-1beta in (C+P) group were significantly higher than other groups (P<0.05).</p><p><b>CONCLUSIONS</b>HDL-C, CRP, IL-6, TNF-alpha and IL-1beta may be associated with the pathogenesis of periodontitis and CHD. There may be a relationship between the two diseases.</p>

Influence of p75 neurotrophin receptor knockout on the regeneration of facial nerves after crush injury in mouse / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the role of p75 neurotrophin receptor (p75NTR) in the regeneration of facial nerve crush injury.</p><p><b>METHODS</b>In p75NTR knockout mice and wild type mice, the regenerating fibres in the facial nerve were also labelled by an anterograde tracer cholera toxin B (CTB). The next day after injury of facial nerve, CTB was injected into the trunk of the nerve in the proximal side of the crush, and then anterograde tracing and immunohistochemistry were used to examine the regeneration of axons after facial nerve crush injury. In p75NTR knockout mice and wild type mice, the facial nerves on one side were crushed and regenerating neurons in the facial nerve nucleus were labelled by Fast Blue. The facial nerve trunk was cut in the bifurcated region in the 4th day after injury and the stump was inserted into a small polymer tube containing Fast Blue. Retrograde tracing and labling motoneuron counting were used to examine the survival of motoneurons in the facial nerve nucleus after facial nerve crush injury.</p><p><b>RESULTS</b>The results showed that the axonal growth of injured axons in the facial nerve of p75NTR knockout mice was significantly retarded. The number of regenerated neurons in the facial nerve nucleus in p75NTR knockout mice was significantly reduced (P < 0.05). Immunohistochemical staining of regenerating axons also showed the reduction in nerve regeneration in p75NTR knockout mice (P < 0.01).</p><p><b>CONCLUSION</b>p75NTR plays an important role in the regeneration of injured peripheral nerves after injury.</p>

The expression of interleukin-10 mRNA in gingival lesion of different clinical states in patients with adult periodontitis / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the expression of interleukin-10 (IL-10) mRNA in gingival tissue of active and stable stage in patients with adult periodontitis.</p><p><b>METHODS</b>12 patients with acute abscesses of the periodontium, 12 patients after periodontal initial treatment and 6 periodontal healthy patients having extraction of impacted wisdom tooth were randomly divided into group A (active stage group), group B (stable stage group) and the control group. Biopsies of gingival tissues were collected from every subject of three groups. Technique of in situ hybridization was applied to observe the expression of IL-10 mRNA in the biopsies from three groups semi-quantitatively.</p><p><b>RESULTS</b>IL-10 mRNA was positively expressed in lymphocytes, macrophages and fibroblasts. The quantity of IL-10 mRNA of group A was the lowest in the three groups and was significantly lower than that of control group and group B respectively (P < 0.01). The quantity of IL-10 mRNA of group B was the highest in the three groups and was significantly higher compared with the control group and group A (P < 0.01).</p><p><b>CONCLUSION</b>The quantities of IL-10 mRNA expression are closely related with various clinical states of periodontitis.</p>

Ultrasound-mediated microbubble destruction enhances bone morphogenetic protein-2 gene expression in mouse skeletal muscles / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To explore whether ultrasound-mediated microbubble destruction can enhance the expression efficiency of plasmid pIRES-rhBMP2-EGFP for bone morphogenetic protein-2(BMP-2) in mice skeletal muscle.</p><p><b>METHODS</b>Twenty four male BALB/c mice were divided into four groups. The naked plasmid was injected into the pretibial muscle or the quadriceps muscle (group A and group C) without ultrasound-mediated microbubble destruction method. Micobubbles with plasmid were injected into the pretibial muscle or the quadriceps muscle (group B and group D) with destructing microbubbles by ultrasound immediately. Twelve mice (group A and group B, 30 microg plasmid injected) were killed after 7 days and the tissue samples of the pretibial muscle were obtained to observe the expression of enhanced green fluorescence protein (EGFP) by inverted fluorescence microscope, gene transfection efficiencies were quantified by counting EGFP positive fibers on mice skeletal muscle. After 14 days, the other twelve mice (group C and group D, 100 microg plasmid injected) were killed and immunnohistochemical technique was applied to detect the rhBMP-2 gene expression.</p><p><b>RESULTS</b>The percentage of GFP-positive fibers was significantly lower in the group A than that in the group B. After 14 days, expression of rhBMP-2 was detected in cells and interstitial spaces in the group C and group D, and expression efficiency of rhBMP-2 in the group D was significantly higher than that in the group C.</p><p><b>CONCLUSION</b>Ultrasound-mediated microbubble destruction could enhance the transfection and expression efficiency of rhBMP-2 gene in skeletal muscle of mouse in vivo. It is a new gene therapy method for periodontal regeneration.</p>

Ultrasound-mediated microbubble destruction enhances exogenous gene expression in NIH3T3 cells in vitro / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the transfection efficiency of the recombinant human bone morphogenetic protein-2 (hBMP-2) gene in targeted cells by ultrasound-mediated microbubble destruction.</p><p><b>METHODS</b>NIH3T3 cells' anabiosis was completed and went down to the 3rd or 4th generation, and cultured in 6 well plates. The cells were divided into 2 groups: Plasmid DNA and Lipofectamine 2000 group (liposome group), plasmid DNA and ultrasound and microbubble group (ultrasound-mediated microbubble destruction group). Plasmid DNA was transfected into cells with liposome or ultrasound and microbubble. 24-48 hours later, the transfection efficiency and the concentrations of hBMP-2 were measured with fluoresence microscope and enzyme-linked immunosorbent assay (ELISA) respectively. The data were analyzed by curve fitting and t-test of SPSS 11.5.</p><p><b>RESULTS</b>The transfection efficiency rate was (7.30 +/- 1.58)% in liposome group, compared with (11.77 +/- 3.16)% in ultrasound-mediated microbubble destruction group (P< 0.05). The concentration of hBMP-2 after transfection was (1164.35 +/- 724.67) pg/mL in liposome group, versus (2932.70 +/- 656.27) pg/mL in ultrasound-mediated microbubble destruction group (P<0.05).</p><p><b>CONCLUSION</b>Ultrasound-mediated microbubble destruction could significantly improve the transfection efficiency and expression of hBMP-2 gene in NIH3T3 cells. It may provide a new and effective gene delivery system for gene therapy in periodontal regeneration.</p>

Biological effects of phenytoin on cultured human periodontal ligament fibroblasts in vitro / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To study the biological effects of phenytoin (PHT) on cultured human periodontal ligament fibroblasts (hPDLF), and explore the possibility of its accelerating periodontal regeneration.</p><p><b>METHODS</b>Increasing concentrations of PHT (1, 5, 20, 100, 500, 2 500 mg/L) were added into the medium of the fourth passage of cultured hPDLF, respectively. After co-incubated for 3 days, cell proliferation activity, the total amount of protein and alkaline phosphatase (ALP) activity were detected. Mineralized sodium and PHT (20, 100, 500 mg/L) were added into the medium of the fourth passage hPDLF. After co-incubated, the mineralized nodules formation were detected by Von Kossa staining. The third passage hPDLF were stimulated by PHT (20, 100 mg/L), bone morphogenetic protein-2 (BMP-2) concentration was analyzed by enzyme linked immunosorbent sandwich assay (ELISA).</p><p><b>RESULTS</b>At the concentration of 20 or 100 mg/L, PHT significantly enhanced the proliferating activity and ALP activity of hPDLF (P<0.01). PHT at 100 mg/L could increase protein synthesis of hPDLF (P<0.05). The capability of mineralization and BMP-2 expression of hPDLF were increased significantly (P<0.01) in 100 mg/L group when compared with that in the control group. However, higher concentration (2 500 mg/L) not only changed cell morphology, but also significantly inhibited cell activity.</p><p><b>CONCLUSION</b>The results suggested that proper doses of PHT could promote proliferation and biosynthesis and also enhance osteogenesis by increasing the differentiation, mineralization and BMP-2 expression of hPDLF while higher concentrations of PHT had cytotoxic effect.</p>

Nasal immunization with co-expression plasmid harboring genes encoding porphyromonas gingivalis FimA and human interleukin-15 in mice / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To observe the antibody responses induced by recombinant plasmid plRES-fimA:IL15 via nasal immunization to BABL/c mice and the regulation of IL-15 to sIgA.</p><p><b>METHODS</b>BABL/c mice were immunized with recombinant plasmids pIRES-fimA:IL15 and pIRES-fimA via nasal or intramuscular route. Serum IgG and salivary sIgA levels after immunization were analyzed by ELISA.</p><p><b>RESULTS</b>Nasal immunization with plasmids pIRESfimA:IL15 or pIRES-fimA elicited significant higher level of salivary FimA-specific sIgA responses compared with intramuscular immunization. There was no significant difference of the serum IgG responses between nasal immunization mice and intramuscular immunization mice. Nasal immunization with plasmid pIRES -fimA:IL15 elicited significant higher level of salivary sIgA response than with pIRES-fimA (P<0.05).</p><p><b>CONCLUSION</b>Nasal dropping may be an effective mucosal immunization route of anti-Porphyromonas gingivalis DNA vaccine to elicit specific antibody responses in serum and oral region. IL-15 has a positive regulation effect to sIgA response.</p>

Effects of retinoic acid on differentiation of periodontal ligament cells / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the effect of retinoic acid on differentiation of periodontal ligament cells (PDLCs) and gingival fibroblasts (GFs).</p><p><b>METHODS</b>The periodontal ligament cells and gingival fibroblasts were cultured, challenged with different concentrations of retinoic acid in medium and detected for the alkaline phosphatase (ALP) activity and its mRNA by biochemical technique, in situ hybridization and RT-PCR.</p><p><b>RESULTS</b>ALP activity in normal PDLCs was higher than that in GFs. The mRNA signals were positive in PDLCs, and negative in GFs. After treated with different concentrations of retinoic acid, ALP activity of PDLCs was increased than that of the control, and its mRNA signals were enhanced, especially in 5 x 10(-6) mol/L. The treated GFs showed a slight increase of ALP activity and a weak band of mRNA signals only in 5 x 10(-6) molUL concentration.</p><p><b>CONCLUSION</b>There were differences between PDLCs and GFs in differentiating into osteoblast-like cells.</p>

Expression of core binding factor a1, bone morphogenetic proteins and osteopontin in the developing periodontal tissues of mice / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To study the expression and interaction of core binding factor a1 (Cbfa1), bone morphogenetic proteins (BMPs) and osteopontin (OPN) in the developing periodontal tissues of mice.</p><p><b>METHODS</b>A mice developing periodontal tissues study model was created histologically by 5-27 day postnatal BALB/c mice, then the immunohistochemical localization of Cbfa1, BMPs and OPN in different developing stages were undertaken.</p><p><b>RESULTS</b>In early stage of postnatal mice periodontal tissues development, only BMPs expressed in dental follicle cells, though the signal was weak. When root was forming, all of them were expressed in periodontal ligament cells and cementoblasts, while only OPN in acellular cementum, cellular cementum and the surface of alveolar bone, Cbfa1 only in cellular cementum and BMPs was seen in neither acellular cementum nor cellular cementum.</p><p><b>CONCLUSION</b>Cbfa1, BMPs and OPN all involve in the development of periodontal tissues, while OPN is crucial for cementum.</p>

Expression of epidermal growth factor receptor in human periodontal ligament cells during their mineralization in vitro / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the expression of epidermal growth factor receptor (EGFR) during the mineralization of human periodontal ligament cells (hPDLC) in vitro.</p><p><b>METHODS</b>Studies using specific antibodies to immunolocalize EGFR in the mineral differentiating hPDLC were undertaken to investigate the different expression during the inducing process. In situ hybridization and RT-PCR technique were used to investigate the transcripts encoding the protein of EGFR.</p><p><b>RESULTS</b>The results showed that immunocytochemical labeling gradually decreased following the elong of the induce time, downing to nearly negative at the 4th week and the signal of EGFR transcripts was weaker in the induced hPDLC than that in uninduced.</p><p><b>CONCLUSION</b>EGFR has a negative regulation function during the mineralization of hPDLC.</p>

Construction of eukaryotic co-expression plasmid harboring genes encoding Porphyromonas gingivalis fim A and human IL-15 / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To construct a eukaryotic co-expression plasmid pIRES-fimA:IL15, which can be used as an immunoreaction-enhancing DNA vaccine against Porphyromonas gingivalis FimA, and investigate its expression in mammalian cells.</p><p><b>METHODS</b>The eukaryotic co-expression plasmid pIRES-fimA:IL15 was constructed by molecular cloning methods and characterized by restricted endonuclease mapping, PCR and DNA sequencing. The plasmid was transfected into mammalian cell CHO using Lipofectamine 2000. Expression of fimA gene was detected by Western blot and the protein secretion in cultural medium was analyzed by ELISA.</p><p><b>RESULTS</b>Endonuclease mapping showed that the target genes fimA and IL-15 obtained by PCR had the same molecular size as predicted. The DNA sequencing data also indicated that inserted fimA gene and IL-15 gene had correct DNA sequence and orientation. The recombined plasmid could express FimA in mammalian cell CHO transfected. FimA and IL-15 could be secreted into cultural supernatant detected by ELISA.</p><p><b>CONCLUSION</b>A new eukaryotic co-expression plasmid pIRES-fimA: IL15 was constructed and it could be applied for further immunization in animal as an effective anti-Porphyromonas gingivalis vaccine.</p>

Experimental study of the dental follicle's function in tooth root development / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To study role of dental follicle in tooth root development.</p><p><b>METHODS</b>Sixteen mandibular first molar dental germs from eight five-day postnatal Balb/c mice were divided into two groups randomly. Dental follicle of germs in one group was undetached and that of another group was removed. Subsequently, each of the germs was separately transplanted to back-muscles of adult nude mice. At seventh and fourteenth day after transplanting, the germs were collected, fixed, demineralized, dehydrated, and embedded in wax in sequence. Serial sections of 5 microm thick were made following the routine methods, stained with haematoxylin-eosin dying solution, and observed under a light microscope.</p><p><b>RESULTS</b>All implantations were located in the back-muscles with abundant capillary vasculature. Under microscope, although all tooth germs could further develop after grafting, tooth germs without dental follicle developed slowly with small size and low calcification compared to those with dental follicle. Although position of Hertwig's epithelial root sheath of all germs seemed no changing, roots of the group with dental follicle could further develop and the roots develop toward the apical direction; this tendency couldn't be seen in the germs of another group. Inflammatory cells could be seen in and out of the pulp cavity of the two groups at 7th day after grafting, while no obvious inflammatory cell was observed at 14th day after grafting.</p><p><b>CONCLUSION</b>Dental follicle play an important role in tooth root development. It probably can lead tooth root to develop in normal direction.</p>

Immunohistochemical localization of leucine-rich proteoglycans in the developing periodontal tissues of mice / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To study the distribution and expression of fibromodulin, decorin and biglycan in developing normal periodontal tissues, so as to understand its role in periodontal tissue formation.</p><p><b>METHODS</b>Thirty six BALB/c mice in different developing stages were killed and their bilateral mandibular first molars with surrounding alveolar bones and gingival tissues were taken out, Power Vision two steps immunohistochemical method with anti-fibromodulin, anti-decorin and anti-biglycan was used to detect the tissue distribution and cellular localization of fibromodulin and related proteoglycans, decorin and biglycan.</p><p><b>RESULTS</b>Fibromodulin was strongly expressed in the subcutaneous gingival connective tissue, periodontal ligament, mainly in gingival and periodontal fibroblasts as well as their matrices. Strong expression was also noted in the area close to the interfaces of periodontal ligament-alveolar bone and periodontal ligament-cementum. Decorin was strongly expressed in the area of gingival connective tissue, periodontal ligament and the surface of alveolar bone, while biglycan was stained evidently in gingival connective tissue throughout the period of investigation, but negative in the surface of alveolar bone and osteoblasts.</p><p><b>CONCLUSIONS</b>Fibromodulin may interact with decorin and biglycan to regulate the network formation of gingival connective tissues and periodontal collagen fibers, and may be involved in mineralization of the alveolar bone and cementum.</p>

Expression of Runx2/Cbfa1 in the developing pulpo-dentinal complex of postnatal mice / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To study the expression of Runx2/Cbfa1 in the developing dentin and differentiating odontoblasts.</p><p><b>METHODS</b>A postnatal mice teeth developing model was built histologically. Immunohistochemical technique was adopted to determine the expression of Runx2/Cbfa1 in the developing pulpo-dentinal complex in mice.</p><p><b>RESULTS</b>Runx2/Cbfa1 was merely present in predentin in the exact and before the 11th day's postnatal stages. Meanwhile, it was positively located in odontoblasts and dental pulp cells in root region, but negatively in coral part after the 11th day's stages.</p><p><b>CONCLUSION</b>Runx2/Cbfa1 may play an important role in the deposing of tooth dentin and in the differentiating of odontoblasts and pulp cells.</p>

Culture and phenotype characteristics of mouse dental follicle cells / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To establish a method for isolating and culturing mouse dental follicle cells and to study the phenotype characteristics of dental follicle cells.</p><p><b>METHODS</b>Mandibular first molars from 9 day old Balb/c mice were digested with 1% trypsin, subsequently, and the dental follicle was enucleated from the tooth germ and cultured. The shape and ultrastructural appearance of dental follicle cells were observed under phase-contrast microscope and scanning electron microscope (SEM). Immunocytochemistry was used to detect the expression of alkaline phosphatase (ALP), bone sialoprotein (BSP) and osteopontin (OPN).</p><p><b>RESULTS</b>Three types of cells were isolated: some were cuboidal/polygonal; some were elongated, spindle-shaped, fibroblast-like cells; and a minor, third cell type was very thin and elongated. The cytoplasm of the first two cell types was filled with abundant granules. The cells were pleomorphism under SEM and had many filipodia and microvilli. According to whether there were filaments overlying the surface, the cells could be divided into two subtypes. Some but not all follicle cells expressed ALP, BSP and OPN.</p><p><b>CONCLUSION</b>The cultured dental follicle cells consisted of several cell phenotypes and had the potential of differentiating into cementoblasts, periodontal ligament fibroblasts and osteoblasts.</p>

The effect of bFGF on proliferation of periodontal fibroblast-like cells of dogs / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the effects of basic fibroblast growth factor(bFGF) on proliferation of periodontal fibroblast-like cells in vivo.</p><p><b>METHODS</b>A U-shaped osseous defect was produced on the buccal side of the mesial root. Four posterior teeth were conducted in four quadrants. Each quadrant included 4 groups: control, bFGF, expanded polytetrafluoroethylene(ePTFE) membrane, bFGF + ePTFE. Each time the 4 teeth sites in one quadrant were operated weekly and each dog experienced 4 times of operations. Bromodeoxyuridine(BrdU) was injected 1 hour prior to sacrificing the dogs at 4 weeks after first surgery. Immunohistochemical method was applied to count the BrdU-labeled fibroblast-like cells.</p><p><b>RESULTS</b>The number of BrdU-labeled cells reached the maximum at the 2nd week among all groups and then, decreased with time. Both bFGF and bFGF + ePTFE treated group had significantly more BrdU+ cells than remained control or ePTFE groups (P < 0.05) at 1st, 2nd weeks after surgery.</p><p><b>CONCLUSION</b>2 weeks after periodontal surgery is active phase of proliferation of periodontal fibroblasts. bFGF enhances fibroblast proliferation in early periodontal wound healing, and in turn accelerate periodontal regeneration.</p>

Biological effects of tetracycline on cultured human periodontal fibroblasts / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To explore the biological effects of tetracycline on cultured human periodontal ligament fibroblasts (HPDLFs).</p><p><b>METHODS</b>Increasing concentrations of tetracycline (1, 5, 20, 100, 500, 2500 microg/ml) were added to the medium of cultured HPDLFs, respectively. After co-incubated for 2 days, cell morphology was observed under reverse microscope, meanwhile, cell proliferation activity was assayed using MTT, the total amount of protein was detected with Coumassie Bright Blue method and DNA synthesis was measured by 3H-TdR.</p><p><b>RESULTS</b>Over a concentration range of 1 to 100 microg/ml, cells demonstrated a normal appearance, spindle or fusiform shaped. Moreover, at a concentration range of 20 to 100 microg/ml, tetracycline significantly enhanced the proliferating activity and biosynthesis of HPDLFs (P < 0.01). However, higher concentration (2500 microg/ml) not only changed cell morphology, but also significantly inhibited cellular activity.</p><p><b>CONCLUSION</b>The results suggested that proper doses of tetracycline could promote proliferation and biosynthesis of HPDLFs while higher concentrations of tetracycline had cytotoxic effect.</p>