Search PubMed⌕ Search

Biomedical subjects

H L Wang

Publications and source records attributed to H L Wang.

At least 37 records · Page 2Linked to original sources
PubMed2001

Neurotensin excitation of serotonergic neurons in the rat nucleus raphe magnus: ionic and molecular mechanisms.

To understand the cellular and molecular mechanisms by which neurotensin (NT) induces an analgesic effect in the nucleus raphe magnus (NRM), whole-cell patch-clamp recordings were performed to investigate the electrophysiological effects of NT on acutely dissociated NRM neurons. Two subtypes of neurons, primary serotonergic and secondary non-serotonergic cells, were identified from acutely isolated NRM neurons. During current-clamp recordings, NT depolarized NRM serotonergic neurons and evoked action potentials. Voltage-clamp recordings showed that NT excited serotonergic neurons by enhancing a voltage-insensitive and non-selective cationic conductance. Both SR48692, a selective antagonist of subtype 1 neurotensin receptor (NTR-1), and SR 142948A, a non-selective antagonist of NTR-1 and subtype 2 neurotensin receptor (NTR-2), failed to prevent neurotensin from exciting NRM serotonergic neurons. NT-evoked cationic current was inhibited by the intracellular administration of GDP-beta-S. NT failed to induce cationic currents after dialyzing serotonergic neurons with the anti-G(alphaq/11) antibody. Cellular Ca(2+) imaging study using fura-2 showed that NT induced the calcium release from the intracellular store. NT-evoked current was blocked after the internal perfusion of heparin, an IP(3) receptor antagonist, or BAPTA, a fast Ca(2+) chelator. It is concluded that neurotensin enhancement of the cationic conductance of NRM serotonergic neurons is mediated by a novel subtype of neurotensin receptors. The coupling mechanism via G(alphaq/11) proteins is likely to involve the generation of IP(3), and subsequent IP(3)-evoked Ca(2+) release from intracellular stores results in activating the non-selective cationic conductance.

Adamantane↗
PubMed2001

Migration of osteoblastic cells on various guided bone regeneration membranes.

To evaluate the biological effects of guided bone regeneration (GBR) barrier materials on osteoblastic cell migration, migration of mouse osteoprogenitor cells (MC3T3-E1) was examined, in vitro, on various membranes. Eight commercially available GBR membranes - bovine type I collagen (BioMend; BM), porcine type I collagen (BioGide; BG), bovine type I atelocollagen (Tissue Guide; TG), polylactic acid (Epi-Guide; EG), co-polymer of polylactic acid and polyglycolic acid (Resolute; RL, Resolut XT; RL-XT), expanded polytetrafluoroethylene (e-PTFE; Gore Tex; GT) and co-polymer of cellulose acetate and nitrocellulose (Millipore filter; MP) - were tested. A 3x5 mm section of the membrane was fixed to the bottom of a culture dish with double-sided adhesive tape, and half of the membrane was closely covered by PARAFILM (American National Can) to leave an unexposed area for cell migration. The border between exposed and unexposed areas was marked as a baseline of cell migration. Membranes were then plated with 3 ml of cell suspension at an initial density of 1x105 cells/ml in alpha-MEM culture medium with 10% fetal bovine serum and ascorbic acid. After a 5-hour incubation, non-attached cells were completely washed out with phosphate buffered saline and the PARAFILM cover was removed. After 3 days cultivation, specimens were fixed with 10% buffered formalin and stained briefly with hematoxylin. The area of cell migration on a membrane was analyzed using a LA 500 Image Analysis System and migration area per unit length of the baseline (mm2/mm) was compared among membranes. Results demonstrated that cell migration was greater in the order: RL>RL-XT, BM, TG, MP>EG, BG. Membranes except for BG, EG and GT showed the migration rate equal to or higher than a plastic culture cover slip (Celldesk) (P<0.01) on which cells generally grow favorably. Only a small number of the cells attached to GT, and the net cell migration for the membrane could not be determined. These results indicate that GBR barrier materials per se may influence the process of bone regeneration in vivo through the effects of their presence on cell migration.

Animals↗
PubMed2001

Assessment of newly developed tongue sulfide probe for detecting oral malodor.

AIM: The present study examined the relationship between sulfide levels on tongue dorsum surfaces (pS levels) and oral malodor. METHOD: The pS levels of 20 systemically healthy volunteers were evaluated using an industrial device equipped with a newly-developed tongue sulfide probe. The pS levels on 3 parts of the tongue--anterior, middle and posterior along the median groove of the tongue dorsum--were determined for each subject. RESULTS: The device reported the pS level in a digital score ranging from 0.0 (< 10(-7) M of sulfide) to 5.0 (> or = 10(-2) M of sulfide) in increments of 0.5. Oral malodor was assessed by measuring the level of volatile sulfur compounds in mouth air, as well as by the organoleptic method. The pS levels were 0.03 +/- 0.11, 0.20 +/- 0.41 and 0.88 +/- 0.76 for the anterior, middle and posterior parts, respectively. This difference was significant (p<0.001). Both oral malodor measurements showed significant correlation (p<0.05) with the pS levels of middle and posterior parts of tongue. CONCLUSION: It was concluded that the tongue sulfide probe might be useful in management of subjects with oral malodor.

Adult↗
PubMed2001

Association between oral malodor and adult periodontitis: a review.

BACKGROUND: Bad breath has a significant impact on our daily social life to those who suffer from it. The majority of bad breath originates within the oral cavity. However, it is also possible that it can come from other sources such as gastric-intestine imbalance. The term "oral malodor" is used to describe a foul or offensive odor emanating from the oral cavity, in which proteolysis, metabolic products of the desquamating cell, and bacterial putrefaction are involved. Recent evidence has demonstrated a link between oral malodor and adult periodontitis. The process of developing bad breath is similar to that noted in the progression of gingivitis/periodontitis. Oral malodor is mainly attributed to volatile sulfur compounds (VSC) such as hydrogen sulfide, methyl mercaptan and dimethyl sulfide. The primary causative microbes are gram-negative, anaerobic bacteria that are similar to the bacteria causing periodontitis. These bacteria produce the VSC by metabolizing different cells/tissues (i.e., epithelial cells, leukocytes, etc.) located in saliva, dental plaque, and gingival crevicular fluid. Tongue surface is composed of blood components, nutrients, large amounts of desquamated epithelial cells and bacteria, suggesting that it has the proteolytic and putrefactive capacity to produce VSC. One of the challenges in dealing with oral malodor is to identify a reliable test for detecting bad breath. AIMS: The purposes of this review article were: (1) to correlate the relationship between oral malodor and adult periodontitis; (2) to analyze current malodor tests and discuss available treatment regimens.

Adult↗
PubMed2001

Molar root anatomy and management of furcation defects.

BACKGROUND, AIMS: Furcally-involved teeth present unique challenges to the success of periodontal therapy. Anatomical and morphological complicating factors dictate modifications in treatment approaches used for managing these areas. METHOD: Various treatment approaches are available for furcally-involved teeth, the choice of which depends on selected interdependent factors. RESULTS: These factors, along with various approaches used in the treatment of furcally compromised teeth are discussed in this review, with particular emphasis on morphology, etiology, classification and diagnosis.

Dental Restoration, Permanent↗
PubMed2001

Attachment, proliferation and differentiation of periodontal ligament cells on various guided tissue regeneration membranes.

The purpose of this study was to evaluate the biological effects of guided tissue regeneration (GTR) membrane materials, per se, on the periodontal tissue regeneration. Rat periodontal ligament (PDL)-derived cells were used to study the attachment, proliferation and differentiation, in vitro, on various GTR membranes. Five commercially available membranes bovine type I collagen (BioMend; BM), bovine type I atelocollagen (Tissue Guide; TG), polylactic acid (Epi-Guide; EG), co-polymer of polylactic acid and polyglycolic acid (Resolute; RL) and expanded polytetrafluoroethylene: e-PTFE (Gore Tex; GT)-were examined. A 3 x 3 mm section of the membrane was fixed to the bottom of a 35 x 10 mm style culture dish and plated with 2 ml of cell suspension at an initial density of 5 x 10(4) cells/ml in culture medium with 10% fetal bovine serum. For cell growth analysis, the specimens were fixed with 10% buffered formalin and stained with hematoxylin at 1.5 hours and 1, 3 and 5 days after cell seeding. The number of cells included in a unit area of 0.25 mm2 were counted under light microscopy. As a comparative scaffold of cell proliferation, a plastic cover for cell culture slip (Celldesk; CD) was used. For analysis of cell differentiation, activity of alkaline phosphatase (ALP) and calcification were histochemically revealed after 2-week cultivation. The initial number of PDL cells attached to the membrane at 1.5 hours after cell seeding was different among membranes. RL, TG and EG had the same level of attached cell numbers as that on CD, while the cell numbers on GT and BM were significantly lower than that on CD (p < 0.01). The rate of cell proliferation with time also differed among the membranes examined. RL and BM demonstrated a significantly higher number of cells at 5 days than at 1.5 hours (p < 0.01). TG had increased numbers of cells at 3 and 5 days after cell seeding. However, there was no statistical difference between the cell numbers at 1.5 hours and 5 days after cell seeding (p > 0.1). EG had a similar number of cell attachments to that at 1.5 hours throughout the experimental period. There was almost no cell proliferation on GT. Cell clusters of ALP positive cells and foci of calcification were seen on all membranes except for GT, where a scant number of cells were seen. Results from this study implied that GTR membrane materials, per se, may influence cell proliferation and differentiation in the process of periodontal tissue regeneration.

Alkaline Phosphatase↗
PubMed2001

G protein-coupled receptor kinase 2 mediates mu-opioid receptor desensitization in GABAergic neurons of the nucleus raphe magnus.

Nucleus raphe magnus (NRM) sends the projection to spinal dorsal horn and inhibits nociceptive transmission. Analgesic effect produced by mu-opioid receptor agonists including morphine partially results from activating the NRM-spinal cord pathway. It is generally believed that mu-opioid receptor agonists disinhibit spinally projecting neurons of the NRM and produce analgesia by hyperpolarizing GABAergic interneurons. In the present study, whole-cell patch-clamp recordings combined with single-cell RT-PCR analysis were used to test the hypothesis that DAMGO ([D-Ala(2),N-methyl-Phe(4),Gly-ol(5)]enkephalin), a specific mu-opioid receptor agonist, selectively hyperpolarizes NRM neurons expressing mRNA of glutamate decarboxylase (GAD(67)). Homologous desensitization of mu-opioid receptors in NRM neurons could result in the development of morphine-induced tolerance. G protein-coupled receptor kinase (GRK) is believed to mediate mu-opioid receptor desensitization in vivo. Therefore, we also investigated the involvement of GRK in mediating homologous desensitization of DAMAMGO-induced electrophysiological effects on NRM neurons by using two experimental strategies. First, single-cell RT-PCR assay was used to study the expression of GRK2 and GRK3 mRNAs in individual DAMGO-responsive NRM neurons. Whole-cell recording was also performed with an internal solution containing the synthetic peptide, which corresponds to G(betagamma)-binding domain of GRK and inhibits G(betagamma) activation of GRK. Our results suggest that DAMGO selectively hyperpolarizes NRM GABAergic neurons by opening inwardly rectifying K(+) channels and that GRK2 mediates short-term homologous desensitization of mu-opioid receptors in NRM GABAergic neurons.

Amino Acid Sequence↗
PubMed2001

The use of autologous fibrinogen concentrate in treating ocular hypotony after glaucoma filtration surgery.

Antimetabolite therapy with 5-fluouracil (5-FU) or mitomycin-C (MMC) has significantly improved the success rate of glaucoma filtration surgery. However, in some eyes, when filtration is excessive, persistent hypotony may develop. In this study, we describe the experience of using autologous fibrinogen concentrate (AFC) to treat patients with persistent hypotony after glaucoma filtration surgery. Among seven MMC-augmented trabeculectomy patients who developed persistent postoperative hypotony, the effects of AFC intrableb injections were evaluated. Under a microscope, 0.2 ml AFC and bovine thrombin were injected into the blebs of the patients from both sides of the filtering blebs. Postoperative best-corrected visual acuity, anterior chamber status, intraocular pressure (IOP) and fundus examination were followed and compared with those preoperative. On the second day, the mean IOP of seven eyes elevated from preoperative 3.4 +/- 2.1 mmHg to 12.6 +/- 4.2 mmHg, and the anterior chamber became deep without obvious inflammatory response. Within two weeks, macular edema and visual acuity were noted to improve in six eyes (85.7%). In addition, after a mean follow-up of 25 months, the trabeculectomy procedure remained successful in all eyes. AFC appears to be safe and effective in the treatment of ocular hypotony after glaucoma filtration surgery.

Adult↗
PubMed2001

Immunohistochemical distinction between primary adenocarcinoma of the bladder and secondary colorectal adenocarcinoma.

Primary adenocarcinoma of the urinary bladder sometimes causes a diagnostic dilemma because it can be indistinguishable morphologically from adenocarcinoma of colorectal origin secondarily involving the bladder by metastasis or direct extension. It is much less well studied than conventional urothelial carcinoma and colorectal adenocarcinoma because of its rarity. The current study was specifically designed to investigate whether an important mechanism involved in the pathogenesis of colorectal adenocarcinoma, beta-catenin dysregulation, was also important for the development of primary bladder adenocarcinoma and whether these two morphologically similar tumors could be distinguished immunohistochemically. Formalin-fixed, paraffin-embedded tissues from 17 primary adenocarcinomas of the urinary bladder, 16 colorectal adenocarcinomas involving the bladder, and 10 conventional urothelial (transitional) carcinomas were included in this study. Thirteen of the primary bladder adenocarcinomas were moderately to well differentiated (enteric type) and morphologically indistinguishable from colorectal cancers. The remaining four primary tumors were poorly differentiated (two cases) or of clear cell type (two cases). Immunohistochemical studies using a panel of monoclonal antibodies demonstrated positive nuclear staining for beta-catenin expression in 13 of the 16 (81%) colorectal adenocarcinomas secondarily involving the bladder but in none of the primary adenocarcinomas or the urothelial carcinomas. Instead, positive membranous (and some cytoplasmic) staining was present in all primary bladder tumors with the exception of two poorly differentiated adenocarcinomas where no beta-catenin staining was detected. All secondary colorectal adenocarcinomas stained negatively for CK7 and thrombomodulin (TM), whereas positivity for CK20 was observed in 15 (94%) cases. All urothelial carcinomas stained positively for CK7 and TM, and four of them also for CK20. Primary adenocarcinomas of the bladder showed mixed staining patterns for CK7, CK20, and TM with a positive rate of 65%, 53%, and 59%, respectively. These data indicate that dysregulation of beta-catenin, an important aberration seen in colorectal carcinogenesis, does not appear to play a role in the pathogenesis of the bladder adenocarcinoma. In addition, our data demonstrate that a panel of immunostains, including CK7, CK20, TM, and beta-catenin, is of diagnostic value in differentiating primary bladder adenocarcinoma from secondary adenocarcinoma of colorectal origin.

Adenocarcinoma↗
PubMed2001

Neurotensin excites periaqueductal gray neurons projecting to the rostral ventromedial medulla.

Microinjection of neurotensin into the midbrain periaqueductal gray (PAG) produces a potent and naloxone-insensitive analgesic effect. To test the hypothesis that neurotensin induces the analgesic effect by activating the PAG-rostral ventromedial medulla (RVM) descending antinociceptive pathway, PAG neurons that project to RVM (PAG-RVM) were identified by microinjecting DiI(C18), a retrograde tracing dye, into the rat RVM. Subsequently, fluorescently labeled PAG-RVM projection neurons were acutely dissociated and selected for whole cell patch-clamp recordings. During current-clamp recordings, neurotensin depolarized retrogradely labeled PAG-RVM neurons and evoked action potentials. Voltage-clamp recordings indicated that neurotensin excited PAG-RVM neurons by opening the voltage-insensitive and nonselective cation channels. Both SR 48692, a selective NTR-1 antagonist, and SR 142948A, a nonselective antagonist of NTR-1 and NTR-2, failed to prevent neurotensin from exciting PAG-RVM neurons. Neurotensin failed to evoke cationic currents after internally perfusing PAG-RVM projection neurons with GDP-beta-S or anti-G(alpha q/11) antiserum. Cellular Ca(2+) fluorescence measurement using fura-2 indicated that neurotensin rapidly induced Ca(2+) release from intracellular stores of PAG-RVM neurons. Neurotensin-evoked cationic currents were blocked by heparin, an IP(3) receptor antagonist, and 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA), a fast chelator of Ca(2+). These results suggest that by activating a novel subtype of neurotensin receptors, neurotensin depolarizes and excites PAG-RVM projection neurons through enhancing Ca(2+)-dependent nonselective cationic conductance. The coupling mechanism via G(alpha q/11) proteins is likely to involve the production of IP(3), and subsequent IP(3)-evoked Ca(2+) release leads to the opening of nonselective cation channels.

Animals↗
PubMed2001

Management of incision design in symphysis graft procedures: a review of the literature.

Symphysis graft procedures are being performed in clinical practice more frequently than ever before. Convenient surgical access, proximity of donor and recipient sites, low morbidity, availability of larger quantities of bone over other donor sites, minimal resorption, no hospitalization, and minimal discomfort are some advantages of this procedure over other intraoral sites. Three types of horizontal incisions can be performed during this procedure: the sulcular, the marginal, and the alveolar mucosal. Most studies regarding the chin graft technique are more concerned with the bone graft aspect than soft tissue management. Moreover, the criteria for the selected flap design appear to be based primarily on clinical experience or the same surgical approach regardless of interfacing factors. The periodontal status, amount of bone loss, periodontal risk of root fenestration, amount of keratinized gingiva, restorations in the gingival margin, and local musculature are some of the clinical findings that should be assessed to indicate the best incision design. In this review article, the advantages, disadvantages, indications, and contraindications of each incision design will be discussed.

Bone Transplantation↗
PubMed2001

Relationship of sulcular sulfide level to severity of periodontal disease and BANA test.

BACKGROUND: Volatile sulfur compounds (VSC), such as hydrogen sulfide and methyl mercaptan, are toxic metabolites produced by periodontal pathogens. Their relationship to periodontal disease severity is not yet fully understood. Hence, the aims of this study were to: 1) examine the relationship between sulcular sulfide (pS) levels and severity of periodontal disease and 2) examine the link between pS level and the BANA (benzoyl-DL-arginine-naphthylamide) test. METHODS: Seventy systemically healthy subjects with a mean age of 53.0 +/- 13.8 years participated. Three sites were selected from each subject based upon radiographic bone loss (RBL): RBL < 2 mm, healthy; RBL > or = 2 to < 4, low to moderate; RBL > or = 4 mm, severe. Periodontal parameters, probing depth (PD), clinical attachment level (CAL), and bleeding on probing (BOP), were recorded. The pS level was measured using a portable sulfide monitor in a digital score ranging from 0.0 (< 10(-7) M of S) to 5.0 (> or = 10(-2) M of S) in increments of 0.5. The presence of specific bacteria in subgingival plaque was detected using BANA test. RESULTS: The mean pS level was 0.10 +/- 0.23, 0.36 +/- 0.48, and 1.10 +/- 0.87 for healthy, low to moderate, and severe disease sites, respectively, and was statistically different (P<0.001). The pS level was positively correlated with the BANA test, and was higher in untreated subjects than maintenance subjects (P<0.01). CONCLUSIONS: The pS level may be a potential indicator for detecting severity of periodontal disease and identifying bacteria that are capable of hydrolyzing BANA.

Adult↗
PubMed2001

Relationship between sulcular sulfide level and oral malodor in subjects with periodontal disease.

BACKGROUND: The relationship between oral malodor and sulfide levels in periodontal pockets (pS) has not yet been determined. The aims of this study were: 1) to identify the correlation among oral malodor, pS levels, and the BANA (benzoyl-DL-arginine-naphthylamide) test and 2) to recognize the interaction between oral malodor, demographic factors, tongue coating, and periodontal condition. METHODS: Eighty-one periodontal patients participated in this study. A portable sulfide monitor and organoleptic method were used to evaluate oral malodor. Demographic data included age, gender, race, and smoking habits. The volume of tongue coating and periodontal condition for all teeth were assessed. The pS levels of 3 different radiographic bone loss (RBL) sites: RBL < 2 mm, healthy; RBL > or = 2 to < 4 mm; low to moderate; RBL > or = 4 mm, severe, were measured using an industrial sulcular sulfide-monitoring device. Subgingival plaque samples from the above 3 sites and tongue scraping were examined by the BANA test. RESULTS: The volume of tongue coating (P<0.001), extent of periodontal disease (P<0.05), pS levels of the sites with low to moderate bone loss (P<0.05), and BANA score of tongue scrapings (P<0.05) were significantly associated with oral malodor. Stepwise multiple regression analysis examined the degree of association between oral malodor and potential explanatory variables. The volume of tongue coating and percent of sites BOP (bleeding on probing) were significantly associated with oral malodor. Females and smoking habit were negatively correlated with organoleptic measurements. CONCLUSIONS: The pS level of the representative sites with low to moderate bone loss demonstrated a modest association with oral malodor. Oral malodor in periodontal patients was primarily associated with tongue coating and gingival inflammation.

Adult↗
PubMed2001

Comparison of 2 clinical techniques for treatment of gingival recession.

BACKGROUND: In early case studies, use of a collagen barrier as a guided tissue regeneration (GTR) material has shown particular promise in procedures aimed at root coverage. The similarities between collagen membrane and subepithelial connective tissue graft (SCTG) have made collagen membrane an attractive and a possible alternative material for root coverage. The purpose of this randomized clinical trial was to compare these 2 techniques, SCTG versus a GTR-based procedure (GTRC), for root coverage/recession treatment. METHODS: Sixteen patients with bilateral Miller's Class I or II (gingival recession > or = 3.0 mm) recession defects were treated either with SCTG or GTRC using a newly designed collagen membrane. Clinical parameters monitored included recession depth (RD), clinical attachment level (CAL), probing depth (PD), width of keratinized gingiva (KG), attached gingiva (AG), and recession width (RW), each measured at the mid-buccal area to the nearest 0.5 mm. Measurements were taken at baseline and 6 months. A standard mucogingival surgical procedure was performed. Data were reported as means +/- SD and were analyzed using the paired t test for univariate analysis and restricted/residual maximal likelihood (REML)-based mixed effect model for multivariate analysis. RESULTS: No statistically significant differences were observed in RD, CAL, KG, and AG between test and control groups at either time period. However, SCTG showed significantly more residual PD and more RW gain when compared to GTRC at 6 months. Both treatments resulted in a statistically significant (P < 0.05) reduction of recession defects (2.5 mm and 2.8 mm), gain of CAL (2.8 mm and 2.3 mm), reduction of RW (1.9 mm and 2.7 mm), and increase of KG (0.7 mm and 1.1 mm) and AG (0.7 mm and 0.5 mm) for GTRC and SCTG, respectively, when comparing 6-month data to baseline. Mean root coverage of 73% (collagen membrane) and 84% (subepithelial connective tissue graft) was achieved. CONCLUSIONS: The 2 techniques are clinically comparable. Use of a modified collagen membrane to attain root coverage may alleviate the need for donor site procurement of connective tissue.

Adult↗
PubMed2001

Collagen membranes: a review.

Collagen materials have been utilized in medicine and dentistry because of their proven biocompatability and capability of promoting wound healing. For guided tissue regeneration (GTR) procedures, collagen membranes have been shown to be comparable to non-absorbable membranes with regard to probing depth reduction, clinical attachment gain, and percent of bone fill. Although these membranes are absorbable, collagen membranes have been demonstrated to prevent epithelial down-growth along the root surfaces during the early phase of wound healing. The use of grafting material in combination with collagen membranes seems to improve clinical outcomes for furcation, but not intrabony, defects when compared to the use of membranes alone. Recently, collagen materials have also been applied in guided bone regeneration (GBR) and root coverage procedures with comparable success rates to non-absorbable expanded polytetrafluoroethylene (ePTFE) membranes and conventional subepithelial connective tissue grafts, respectively. Long-term clinical trials are still needed to further evaluate the benefits of collagen membranes in periodontal and peri-implant defects. This article will review the rationale for each indication and its related literature, both in vitro and in vivo studies. The properties that make collagen membranes attractive for use in regenerative therapy will be addressed. In addition, varieties of cross-linking techniques utilized to retard the degradation rate of collagen membranes will be discussed.

Absorbable Implants↗
PubMed2001

Effect of non-surgical periodontal therapy on C-telopeptide pyridinoline cross-links (ICTP) and interleukin-1 levels.

BACKGROUND: Biochemical markers harvested from gingival crevicular fluid (GCF) may be useful to identify and predict periodontal disease progression and to monitor the response to treatment. C-telopeptide pyridinoline cross-links (ICTP), a host-derived breakdown product specific for bone, and interleukin-1beta (IL-1), a potent bone-resorptive cytokine, have been associated with periodontal tissue destruction. The aim of this study was to examine the effect of non-surgical periodontal therapy on GCF levels of ICTP and IL-1. METHODS: Twenty-five chronic periodontitis subjects were monitored at 8 sites per subject at baseline prior to scaling and root planing and 1, 3, and 6 months after therapy. Four shallow (probing depths < 4 mm) and 4 deep (probing depths > or = 5 mm) sites were monitored for both marker levels and clinical parameters. GCF was collected for 30 seconds on paper strips, and levels of ICTP and IL-1 were determined using radioimmunoassay (RIA) and enzyme-linked immunosorbent assay (ELISA) techniques, respectively. Clinical measurements included probing depth (PD), clinical attachment level (CAL), and bleeding on probing (BOP). RESULTS: Deep sites exhibited significantly (P<0.001) higher ICTP and IL-1 levels compared to shallow sites at all time intervals. ICTP demonstrated a stronger association to clinical parameters than IL-1 including a modest correlation (r = 0.40, P<0.001) between ICTP and attachment loss. Significant improvements in PD, CAL, and BOP were observed at 1, 3, and 6 months in all sites (P<0.01). However, non-surgical mechanical therapy did not significantly reduce ICTP and IL-1 levels over the 6-month period. Further examination of subjects based on smoking status revealed that ICTP levels were significantly reduced at 3 and 6 months and IL-1 levels reduced at 3 months among non-smokers only. CONCLUSIONS: A single episode of non-surgical mechanical therapy did not significantly reduce biochemical markers associated with bone resorption in patients exhibiting chronic periodontitis. Future longitudinal studies are warranted to specifically evaluate the relationship between C-telopeptide pyridinoline cross-links and periodontal disease progression.

Adult↗
PubMed2001

[Immunologic properties of coli surface antigen 6(CS6) of enterotoxigenic Escherichia coli and cholera toxin subunit B expressed in Shigella flexneri 2a strain T32].

A host-plasmid balancing system composed with a delta asd mutant (FaD) of an avirulent strain (T32) of Shigella flexneri 2a and plasmid harboring asd gene was used to express enterotoxigenic E. coli surface antigen 6(CS6) and V. cholerae toxin subunit B (CTB). The results of Western blotting and ELISA showed that all of recombinant plasmids (pYX201, pYX202 and pYX203) could be maintained stably and expressed CS6 and CTB respectively in T32 without any antibiotic selection. All the recombinant bacterial strains could elicit the corresponding antibodies in rabbits. The antibodies against CTB elicited by both FaD/pYX201 and FaD/pYX203 showed to be high level, and had long prolongation time, in otherwise, the antibodies against CS6 showed to be low level, indicating that higher expression level of foreign antigen may be benefit for construction of genetic multivalent vaccine.

Animals↗