Biomedical subjects

Qing Li

Publications and source records attributed to Qing Li.

At least 127 records · Page 7Linked to original sources

PubMed2004

Cholecystokinin octapeptide increases free intracellular calcium of guinea pig cardiomyocytes through activation of Ca2+ channel and tyrosine kinase.

The aim of the present study was to explore the effect of cholecystokinin octapeptide (CCK-8) on [Ca(2+)](i) and its signal transduction mechanism in isolated guinea pig cardiomyocytes. [Ca(2+)](i) was measured by laser scanning confocal microscopy in single ventricular myocytes which were dissociated by enzymatic dissociation method and loaded with Fluo 3-AM. The changes in [Ca(2+)](i) were represented by fluorescent intensity (F(i)) or relative fluorescent intensity (F(i)/F(O)%). The results obtained are as follows. (1) In the normal Tyrode's solution containing 1.0 mmol/ L Ca(2+), CCK-8 (1-10(4) pmol/L) elicited a rapid and marked increase in [Ca(2+)](i). (2) When cardiomyocytes were pretreated with the Ca(2+) chelator EGTA (3 mmol/L) and Ca(2+) channel antagonist nisoldipine (0.5 micromol/L) for 5 min, CCK-8 (10(2)pmol/L) caused a slow and small increase in [Ca(2+)](i) (p< 0.01). (3) Pretreatment with the nonselected CCK- receptor (CCK-R) antagonist proglumide (6 micromol/L) or the tyrosine kinase inhibitor genistein (1 micromol/L) for 5 min could inhibit the increase of [Ca(2+)](i) induced by CCK-8 (10(2) pmol/L) (p<0.01). The results suggest that CCK-8 increases the [Ca(2+)](i) via activating the receptor-operated Ca(2+) channel and eliciting the influx of Ca(2+) in isolated guinea pig cardiomyocytes, in which tyrosine kinase may be involved.

Animals↗

PubMed2004

Disruption of response regulator gene, devR, leads to attenuation in virulence of Mycobacterium tuberculosis.

The devR-devS two-component system of Mycobacterium tuberculosis was identified earlier and partially characterized in our laboratory. A devR::kan mutant of M. tuberculosis was constructed by allelic exchange. The devR mutant strain showed reduced cell-to-cell adherence in comparison to the parental strain in laboratory culture media. This phenotype was reversed on complementation with a wild-type copy of devR. The devR mutant and parental strains grew at equivalent rates within human monocytes either in the absence or in the presence of lymphocytic cells. The expression of DevR was not modulated upon entry of M. tuberculosis into human monocytes. However, guinea pigs infected with the mutant strain showed a significant decrease in gross lesions in lung, liver and spleen; only mild pathological changes in liver and lung; and a nearly 3 log lower bacterial burden in spleen compared to guinea pigs infected with the parental strain. Our results suggest that DevR is required for virulence in guinea pigs but is not essential for entry, survival and multiplication of M. tuberculosis within human monocytes in vitro. The attenuation in virulence of the devR mutant in guinea pigs together with DevR-DevS being a bona fide signal transduction system indicates that DevR plays a critical and regulatory role in the adaptation and survival of M. tuberculosis within tissues.

Amino Acid Sequence↗

PubMed2004

Transporter-mediated renal handling of nafamostat mesilate.

Nafamostat mesilate (NM) is a serine-protease inhibitor that is rapidly eliminated from the circulation and accumulated in the kidney. This study was conducted to characterize the mechanism of NM transport in the kidney because a serious side effect of NM-induced hyperkalemia may be related to accumulation of NM in the kidney. Measurements of uptake of NM in vivo by the kidney uptake index (KUI) method and of transport in an in vitro-cultured LLC-PK1 cell system suggested the involvement of an organic cation transporter (OCT). To clarify the involvement of OCTs located in the basolateral membrane of proximal tubules, we evaluated NM transport by OCTs expressed in Xenopus laevis oocytes. The IC(50) values of NM on [(14)C]TEA ([(14)C]tetraethylammonium) uptake by rOCT1, rOCT2, and hOCT2 were 50, 0.5, and 20 microM, respectively, and NM was concluded to be a substrate of OCTs. To investigate the transport of NM across the brush-border membrane, we examined the uptake of NM into brush-border membrane vesicles (BBMVs) isolated from rat renal cortex. NM was taken up into the BBMVs, and the uptake was decreased by unlabeled NM and temperature, implying that a transporter(s) is also involved in NM transport across the apical membrane. NM was not a substrate of hOCTN1, hOCTN2, or P-gp, implying the involvement of some unknown transporter(s). Thus, renal accumulation of NM can be explained by the involvement of the basolateral OCTs, though the influence of the apical membrane transporter remains to be clarified.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed2004

PPF1 inhibits programmed cell death in apical meristems of both G2 pea and transgenic Arabidopsis plants possibly by delaying cytosolic Ca2+ elevation.

PPF1 encodes a putative calcium ion carrier that affects the flowering time of transgenic Arabidopsis by modulating Ca(2+) storage capacities in chloroplasts of a plant cell. In the current work, we found that differential expression of PPF1 might affect processes of programmed cell death (PCD) since DNA fragmentation was detected in senescencing apical buds of long day-grown G2 pea (Pisum sativum L.) plants, but was not in non-senescencing short day-grown counterparts at all growth stages. An animal inhibitor of caspase-activated DNase (ICAD) homologue was detected in short day-grown plant continuously throughout the whole experiment and only in early stages of long day-grown pre-floral G2 pea apical buds. DNA fragmentation was significantly inhibited in apical meristems of transgenic Arabidopsis that over-expressed the PPF1 gene when compared to that of either wild-type control or to PPF1 (-) plants. The expression of ICAD-like protein decreased to undetectable level at 45 dpg in apical tissues of PPF1 (-) Arabidopsis, which was much earlier than that found in PPF1 (+) or wild-type controls. In epidermal cells of PPF1 (-) plants, we recorded significantly earlier calcium transient prior to PCD. We suggest that the expression of PPF1, a chloroplast localized Ca(2+) ion channel may inhibit programmed cell death in apical meristems of flowering plants by keeping a low cytoplasmic calcium content that might inhibit DNA fragmentation in plant cells.

Apoptosis↗

PubMed2004

Statistical methods for testing effects on "maximum lifespan".

It has been noted that certain interventions such as caloric restriction may increase maximum lifespan, whereas other interventions may increase mean or median lifespan but not maximum lifespan. Here the term "maximum lifespan" is used to refer to the upper percentiles of the distribution of lifespan. This is of great interest because increasing maximum lifespan may be an indicator that an intervention is slowing the general process of aging and not merely retarding the development of specific diseases. However, formal methods for testing maximum lifespan have not been elucidated. Herein, we show via simulation that conditional t-test (CTT), a method that is sometimes used, is invalid. We then offer a new method based on quantile regression and we show that this method is, at worst, conservative and remains powerful and valid.

Animals↗

PubMed2004

Increased angiogenic response in aortic explants of collagen XVIII/endostatin-null mice.

Endostatin, a proteolytic fragment of basement membrane-associated collagen XVIII, has been shown to be a potent angiogenesis inhibitor both in vivo and in vitro when given at high concentrations. The precise molecular mechanisms by which it functions and whether or not it plays a role in physiological regulation of angiogenesis are not clear. In mice with targeted null alleles of Col18a1, there appears to be no major abnormality in vascular patterns or capillary density in most organs. Furthermore, the growth of experimental tumors is not increased. However, a detailed analysis of induced angiogenesis in these mice has not been performed. Therefore, we compared the angiogenic responses induced by in vitro culture of aortic explants from collagen XVIII/endostatin-null mice (ko) to wild-type (wt) littermates. We found a twofold increase in microvessel outgrowth in explants from ko mice, relative to wt explants. This increased angiogenesis was reduced to the wt level by the addition of low levels (0.1 microg/ml) of recombinant mouse or human endostatin during the culture period. To address cellular/molecular mechanisms underlying this difference in angiogenic response between ko and wt mice, we isolated endothelial cells from both strains and compared their biological behavior. Proliferation assays showed no difference between the two types of endothelial cells. In contrast, adhesion assays showed a striking difference in their ability to adhere to fibronectin suggesting that collagen XVIII/endostatin may regulate interactions between endothelial cells and underlying basement membrane-associated components, including fibronectin, such that in the absence of collagen XVIII/endostatin, endothelial cells are more adhesive to fibronectin. In the aortic explant assay, characterized by dynamic processes of microvessel elongation and regression, this may result in stabilization of newly formed vessels, reduced regression, and a net increase in microvessel outgrowth in explants from ko mice compared to the wt littermates.

Animals↗

PubMed2004

Determination of mangiferin, jateorrhizine, palmatine, berberine, cinnamic acid, and cinnamaldehyde in the traditional Chinese medicinal preparation Zi-Shen pill by high-performance liquid chromatography.

High-performance liquid chromatography is employed to determine the contents of six marker components such as mangiferin, jateorrhizine, palmatine, berberine, cinnamic acid, and cinnamaldehyde in the traditional Chinese medicinal preparation Zi-Shen pill. The separation is performed on a C(18) column by stepwise gradient elution with water (0.2%, v/v, triethylamine adjusted to pH 4 with phosphoric acid)-methanol-acetonitrile (0.01 min, 98:0:2; 20 min, 80:5:15; 30 min, 65:13:22; and 55 min, 65:13:22) as the mobile phase at a flow rate of 0.9 mL/min, with UV detection at 280 nm. Six regression equations show good linear relationships between the peak area of each marker and concentration. The recoveries of the markers listed are 95.5%, 98.3%, 96.8%, 99.5%, 101.7%, and 102.1%, respectively. The repeatability and reproducibility (relative standard deviation) of the method are less than 2.5% and 3.3%, respectively.

Acrolein↗

PubMed2004

Skp2 and p27kip1 expression in melanocytic nevi and melanoma: an inverse relationship.

BACKGROUND: S-phase kinase associated protein-2 (Skp2) ubiquitin ligase p45(SKP2) is important in the degradation of p27kip1 (a cyclin dependent kinase inhibitor) and progression through the G1-S cell-cycle checkpoint. Low levels of p27 and high levels of Skp2 are related to poor prognosis in some cancers. METHODS: Clinicopathologic features and immunohistochemical expression of Skp2 and p27kip1 were investigated in 198 melanocytic proliferations: 21 melanocytic nevi, 23 melanoma in situ, 119 primary melanoma, and 35 metastatic melanoma samples. Comparative and survival analyses were performed. RESULTS: Progressive and significant increases and decreases in the nuclear expression of Skp2 and p27kip1, respectively, was identified moving from melanocytic nevi (0.05 +/- 0.2/85 +/- 15) to melanoma in situ (3 +/- 2/45 +/- 20) to primary cutaneous melanoma (12 +/- 9/30 +/- 25) to metastatic melanoma (25 +/- 15/15 +/- 20) (p < or = 0.006). Expression of these proteins also significantly correlated with increasing American Joint Committee on Cancer (AJCC) T (tumor) classification and AJCC stage (p < or = 0.01). Moreover, the level of these two proteins exhibited a significant inverse relationship (r = -0.4, p = 0.0001). Skp2 cytoplasmic labeling index of >20% predicted worse 10-year overall survival (38% vs. 86%, p = 0.04) in primary melanoma. Neither p27 nor Skp2 nuclear expression impacted significantly on prognosis. CONCLUSIONS: Gain of Skp2 and loss of p27kip1 protein expression are implicated in melanoma progression where the level of p27kip1 may be regulated by targeted proteolysis via Skp2. Cytoplasmic expression of Skp2 defines a subset of aggressive melanomas and could represent another pathway of deregulation of the cell cycle.

Adult↗

PubMed2004

T102C genetic polymorphism of the 5-HT2A receptor in Chinese hypertensive patients and healthy controls.

1. The 5-HT(2A) receptor belongs to the G-protein superfamily. It plays an important role in vascular regulation. 2. Previous reports in the UK have indicated that there is an association of the T102C genetic polymorphism of the 5-HT(2A) receptor with hypertension, but no studies have been made on the T102C genetic polymorphism in Chinese hypertensive patients. In the present study, we investigated the T102C genetic polymorphism of 5-HT(2A) receptors in Chinese hypertensive patients to determine whether there is an association of this polymorphism with hypertension in Chinese. 3. The present study was conducted on 198 hypertensive patients and 164 healthy controls. Polymerase chain reaction-restriction fragment length polymorphism was used to identify the T102C genetic polymorphism of the 5-HT(2A) receptor. 4. In the present study, the C allele frequency of the 5-HT(2A) receptor genetic polymorphism was 0.343 in hypertensive patients, which was not significantly different to that in healthy controls (0.393; chi(2) = 1.922; P = 0.166; odds ratio = 0.807, 95% confidence interval 0.596-1.093). In addition, no gender differences were observed. 5. In conclusion, to our knowledge, this is the first report on the T102C genetic polymorphism of the 5-HT(2A) receptor in Chinese hypertensive patients. We find that no correlation exists between the T102C genetic polymorphism and hypertension, which affords useful information on the pathogenesis of hypertension in the Chinese population.

Aged↗

PubMed2004

Mechanism of action of NB2001 and NB2030, novel antibacterial agents activated by beta-lactamases.

Two potent antibacterial agents designed to undergo enzyme-catalyzed therapeutic activation were evaluated for their mechanisms of action. The compounds, NB2001 and NB2030, contain a cephalosporin with a thienyl (NB2001) or a tetrazole (NB2030) ring at the C-7 position and are linked to the antibacterial triclosan at the C-3 position. The compounds exploit beta-lactamases to release triclosan through hydrolysis of the beta-lactam ring. Like cephalothin, NB2001 and NB2030 were hydrolyzed by class A beta-lactamases (Escherichia coli TEM-1 and, to a lesser degree, Staphylococcus aureus PC1) and class C beta-lactamases (Enterobacter cloacae P99 and E. coli AmpC) with comparable catalytic efficiencies (k(cat)/K(m)). They also bound to the penicillin-binding proteins of S. aureus and E. coli, but with reduced affinities relative to that of cephalothin. Accordingly, they produced a cell morphology in E. coli consistent with the toxophore rather than the beta-lactam being responsible for antibacterial activity. In biochemical assays, they inhibited the triclosan target enoyl reductase (FabI), with 50% inhibitory concentrations being markedly reduced relative to that of free triclosan. The transport of NB2001, NB2030, and triclosan was rapid, with significant accumulation of triclosan in both S. aureus and E. coli. Taken together, the results suggest that NB2001 and NB2030 act primarily as triclosan prodrugs in S. aureus and E. coli.

Anti-Bacterial Agents↗

PubMed2004

Enhancement of P2X(7)-induced pore formation and apoptosis: an early effect of diabetes on the retinal microvasculature.

PURPOSE: A sight-threatening complication of diabetes is cell death in retinal capillaries. Currently, the mechanisms responsible for this classic manifestation of diabetic retinopathy remain uncertain. The hypothesis for the current study is that diabetes increases the vulnerability of retinal microvessels to the potentially lethal consequences of having their P2X(7) purinoceptors activated. A pathophysiological role is suspected for these receptor-operated channels because, in addition to transducing retinovascular responses to extracellular adenosine triphosphate (ATP), the sustained opening of these channels can induce the formation of large transmembrane pores. METHODS: In pericyte-containing retinal microvessels that were freshly isolated from nondiabetic and streptozotocin-injected rats, cells with pores were identified by the uptake of YO-PRO-1. Cell viability was assayed by trypan blue dye exclusion, and cleaved caspase-3 immunoreactivity, TUNEL positivity, and nuclear morphology were used to detect apoptotic cells. Patch-clamp recordings assessed electrophysiological parameters. RESULTS: Activation of P2X(7) receptors caused large pores to form and apoptosis to occur in retinal capillaries of nondiabetic and diabetic rats. Of importance to diabetes, the agonist concentration needed to open pores and trigger apoptosis decreased markedly soon after the onset of streptozotocin-induced hyperglycemia. However, despite this increased sensitivity, diabetes minimally affected the P2X(7)-induced ionic currents. Thus, rather than upregulate the number of functional P2X(7) receptor/channels, diabetes appears to facilitate the channel-to-pore transition that occurs during activation of these purinoceptors. In this way, normally nonlethal concentrations of P2X(7) ligands may trigger apoptosis in microvessels of the diabetic retina. CONCLUSIONS: A diabetes-induced increase in the vulnerability of retinal microvessels to the lethal effect of P2X(7) receptor activation may be a previously unrecognized mechanism by which diabetic retinopathy progresses.

Adenosine Triphosphate↗

PubMed2004

The influence of St John's Wort on CYP2C19 activity with respect to genotype.

Induction of cytochrome p450 isozymes is the major cause for clinical drug interactions of St. John's wort. The relationships of St. John's wort to cytochrome p450 isoforms have been fully investigated, but its effect on CYP2C19 is lacking. Thus, the aim of the present study was to observe the effect of St. John's wort on CYP2C19 activity using CYP1A2 as a control. Twelve healthy adult men-6 extensive metabolizers of CYP2C19 (2C19(*)1/2C19(*)1) and 6 poor metabolizers (4 2C19(*)2/2C19(*)2 and 2 2C19(*)2/2C19(*)3)-were enrolled in a two-phase, randomized, crossover manner. All subjects took a 300-mg St. John's wort tablet or placebo three times daily for 14 days, and then the activities of CYP2C19 and CYP1A2 were measured using mephenytoin and caffeine. It was found that St. John's wort treatment significantly increased CYP2C19 activity in CYP2C19 wild-genotype subjects, with urinary 4'-hydroxymephenytoin excretion raised by 151.5% +/- 91.9% (p = 0.0156), whereas no significant alteration was observed for CYP2C19 poor metabolizers. Repeated St. John's wort administration did not affect the CYP1A2 phenotypic ratio for both CYP2C19 genotype subjects. In conclusion, St. John's wort is an inducer to the human CYP2C19, and clinicians should pay great attention when St. John's wort is added to or withdrawn from an existing drug regimen containing substrates for such enzymes.

Adult↗

PubMed2004

Effects of 17beta-estradiol on in vitro maturation of pig oocytes in protein-free medium.

The present study examined the effects of 17 beta-estradiol (E(2)) on in vitro maturation and subsequent in vitro fertilization of pig oocytes matured with or without cumulus cells. When E(2) (10 ng/ml) was added to the protein-free maturation medium, the proportions of cumulus-enclosed oocytes that underwent germinal vesicle breakdown and reached metaphase II were significantly reduced (P<0.05), and cumulus expansion was also significantly inhibited (P<0.05) compared with the control (no E(2) added). Although oocytes matured in the presence of E(2) were penetrated by sperm in vitro at the same level as the control, the incidences of male pronuclear (MPN) formation and activated oocytes were significantly lower (P<0.05) than the control. These inhibitory effects of E(2) were prevented when the medium was supplemented with E(2) together with its antagonist, ICI 182,780 (1 microg/ml), although the presence of the antagonist alone in the medium had no effect on the maturation and fertilization in vitro of oocytes. In cumulus-free oocytes, E(2) had no effect on nuclear maturation and penetration in vitro, but low MPN formation was observed in oocytes matured in the presence and absence of E(2). When cumulus-enclosed oocytes were cultured in the presence of progesterone (P(4); 600 ng/ml) alone or together with E(2), no significant differences in nuclear maturation, cumulus expansion or penetration in vitro were observed compared with control oocytes. The concentration of P(4) in maturation medium was significantly (P<0.01) lower when cumulus-enclosed oocytes were cultured for 44 h in the medium with E(2) than in medium without E(2). These results indicate that E(2) inhibits both nuclear and cytoplasmic maturation of cumulus-enclosed pig oocytes, and that this inhibition can be prevented by an E(2) antagonist or P(4). This E(2) inhibition may occur indirectly via the cumulus cells and inhibition of P(4) synthesis.

Animals↗

PubMed2004

Induction of tolerance in quadruple chimeric mice.

Human cord blood (CB) contains hematopoietic stem cells and progenitors. Because the major limitation to a widespread use of CB for transplantation lies in its limited volume, it is necessary to combine the CB from several donors. In this study, we show that lethally irradiated mice can be reconstituted with the injection of a mixture of T cell-depleted bone marrow cells (BMCs; total, 3 x 10(6)) obtained from three fully allogeneic mouse strains in two different mouse combinations. A higher survival rate was obtained in the triple injection group than in mice injected with BMCs (1 x10(6)) obtained from a single mouse strain. In the mixed chimeric mice, three kinds of donor-type and recipient-type cells were detected in all the hematopoietic organs 1 month after bone marrow transplantation (BMT). Mixed-lymphocyte reaction showed that the tolerance to both recipient-type and donor-type major histocompatibility complex determinants was induced in the chimeric mice. In the peripheral blood (PB) of these mice, only one type of cells from the three different donor strains became dominant in most chimeric mice and reached a stable level about 4 months after BMT. Polymerase chain reaction analyses, however, revealed that the skins from all the donors were accepted even when no cells with their phenotypes could be detected in the PB. These results suggest that both hemato-lymphoid reconstitution and stable tolerance to not only the recipient strain but also all the donor strains can be achieved in chimeric mice, indicating the possibility of mixed CB transplantation in humans.

Animals↗

PubMed2004

Enhanced reduction and determination of trace thyroxine at carbon paste electrode in the presence of trace cetyltrimethylammonium bromide.

The electrochemical response of thyroxine (T4) at a carbon paste electrode (CPE) in the presence of cetyltrimethylammonium bromide (CTAB) was investigated. It gave a well-defined oxidation peak at 0.80 V and a sensitive reduction peak at 0.40 V. Compared with the indiscernible signal in the absence of CTAB, the reduction current of T4 at CPE was greatly enhanced in the presence of CTAB, due to the interactions between T4, CTAB and the hydrophobic electrode surface. The electrode process of T4 was explored by cyclic voltammetry and chronocoulometry. The effect of surfactants on the reduction reaction proved that bromide ions (Br(-)) in CTAB might form special ion complexes with T4 via a special interaction with the iodine atoms on T4, which would activate the reduction of T4. The sensitive and selective reduction of T4 in this system was applied to the determination of T4 in drugs; a detection limit of 6.5 x 10(-9) M was obtained (sigma= 3).

Bromides↗

PubMed2004

[Influence of chronic epilepsy on spatial memory retrieval in rats].

OBJECTIVE: To investigate the influence of chronic epilepsy on spatial memory retrieval in rats, and to evaluate the effects of TAK-147, an acetylcholinesterase inhibitor, and histidine, the precursor of histamine, on the amnesia induced by epilepsy. METHODS: After successfully trained in the 8-arm (4-arm baited) radial maze, the rats were ip injected with a subconvulsive dose of pentylenetetrazole (PTZ) every 48 h until fully kindled. Memory retrieval was tested at the same maze. RESULT: Impairment of memory retrieval was in a steady state 1 to 18 days after fully kindled, the ability of memory retrieval returned to the control level 31 days after fully kindled. TAK-147 showed an ameliorating effect on memory impairment induced by epilepsy, including reference and working memory in a dose-dependent manner. Histidine only ameliorated reference but not working memory. CONCLUSION: PTZ-kindled seizure impair spatial memory retrieval, which it might be due to a decrease of brain acetylcholine and histamine induced by epilepsy.

Animals↗

PubMed2004

Melatonin reduces peroxynitrite-induced injury in aortic smooth muscle cells.

AIM: To study the protective role of melatonin (MT) in peroxynitrite-induced injury in cultured aortic smooth muscular cells (ASMC). METHODS: Peroxynitrite was synthesized chemically with a quenched flow reaction. Cells were exposed to peroxynitrite 500 micromol/L for 1 h in the absence or presence of various concentrations of MT 100, 300, and 500 micromol/L. Nitrotyrosine (NT), a specific "footprint"of peroxynitrite formation, was detected by immunohistochemical technique. The DNA damage was assayed by TUNEL technique. The levels of MDA in the medium and cell viability were measured. RESULTS: Incubation of ASMC with peroxynitrite 500 micromol/L for 1 h elicited the increase in the extent of immunostaining for NT, the rate of the TUNEL-positive cell, the content of MDA in the medium, and the number of dead cell. Pretreatment of ASMC with MT 100-500 micromol/L decreased these peroxynitrite-induced changes in a concentration-dependent manner. CONCLUSION: MT attenuated the injury induced by peroxynitrite in ASMC.

Animals↗

PubMed2004

[Experimental study on in vitro lamina propria engineering using oral fibroblast and polyglycolic acids].

PURPOSE: This study investigated the feasibility of lamina propria engineering in vitro using expanded oral fibroblast(OFC) and Polyglycolic Acids (PGA). METHODS: OFC were isolated by tissue explant method and expanded in vitro. OFC (20x10(6)) of 3rd passage were collected and then seeded onto PGA unwoven fibers to form a cell-scaffold. The constructs were cultured in DMEM +10% FBS. The cell-scaffold constructs were observed continuously by microscope. Small fragments were harvested at 1 week for electromicroscope, histological and RT-PCR analysis. RESULTS: At the sixth day, a neo-lamina propria was formed. HE and Masson stain revealed the formation of collagen fibers. RT-PCR revealed the new forming collagen was mainly type I collagen. CONCLUSION: lamina propria tissue is possible to engineer in vitro using oral fibroblast and polyglycolic acids. At this basis, we can construct bi-layer tissue engineering oral mucosa in the further research.

Fibroblasts↗