Interleukin-1 and interleukin-8 in nicotine- and lipopolysaccharide-exposed gingival keratinocyte cultures.

BACKGROUND AND OBJECTIVE: Tobacco use is associated with increased periodontal destruction in both cigarette smokers and smokeless tobacco users. Gingival keratinocytes are the first cells in contact with microbial and tobacco components and play a key role in the innate immune response to these agents. The objective of this study was to evaluate the effect of nicotine and bacterial lipopolysaccharide (LPS) alone and in combination on gingival keratinocyte production of interleukin-1 alpha (IL-1 alpha) and interleukin-8 (IL-8). MATERIAL AND METHODS: Gingival keratinocyte cultures were established from 10 healthy, non-tobacco-using subjects. The cells were stimulated for 24 h with 1 mum or 1 mm nicotine and/or 10 microg/mL Escherichia coli or Porphyromonas gingivalis LPS. Interleukin-1 alpha and IL-8 proteins were quantified using ELISAs. RESULTS: Compared with untreated cultures, 1 mm nicotine stimulated production of IL-1 alpha (p < 0.001); E. coli and P. gingivalis LPS increased IL-8 production (p = 0.0014 and p = 0.0232, respectively). A combination of nicotine and LPS produced the highest cytokine quantities. Amounts of IL-1 alpha and IL-8 following 1 mm nicotine and LPS exposure were significantly greater than in untreated cultures (p < 0.001). Interleukin-8 was also responsive to 0.1 mum nicotine combined with E. coli or P. gingivalis LPS compared with control cultures (p < 0.0001 and p = 0.0029, respectively). Both cytokines tended to be elevated following the combined treatment relative to nicotine or LPS treatment alone. CONCLUSION: These results demonstrate that nicotine and LPS differentially regulate IL-1 and IL-8 production by gingival keratinocytes. Combined treatment tended to elevate cytokine production further, which may have implications for the progression of periodontitis in tobacco users.

A multiplex immunoassay demonstrates reductions in gingival crevicular fluid cytokines following initial periodontal therapy.

BACKGROUND AND OBJECTIVE: Cytokines and chemokines play an important role in the pathogenesis of periodontal diseases. The objective of this study was to quantitatively assess the effect of initial periodontal therapy on gingival crevicular fluid levels of a comprehensive panel of cytokines and chemokines, including several less extensively studied mediators. MATERIAL AND METHODS: Clinical examinations were performed and gingival crevicular fluid samples obtained from six subjects with generalized severe chronic periodontitis prior to initial periodontal therapy and at re-evaluation (6-8 weeks). Four diseased and two healthy sites were sampled in each subject. Twenty-two gingival crevicular fluid mediators were examined using a multiplex antibody capture and detection platform. Statistical analyses were performed by fitting mixed effects linear models to log-transformed gingival crevicular fluid values. RESULTS: Gingival crevicular fluid interleukin (IL)-1alpha and IL-1beta were the only cytokines to differ in initially diseased vs. initially healthy sites. Following initial therapy, 13 of the 16 detectable cytokines and chemokines decreased significantly in diseased sites, including IL-1alpha, IL-1beta, IL-2, IL-3, IL-6, IL-7, IL-8, IL-12 (p40), CCL5/regulated on activation, normally T cell expressed and secreted (RANTES), eotaxin, macrophage chemotactic protein-1, macrophage inflammatory protein-1alpha and interferon-gamma. At healthy sites, only three of the 16 mediators were significantly altered following therapy. CONCLUSION: This is the first study, to our knowledge, to evaluate such an extensive panel of gingival crevicular fluid mediators within the same sample prior to and following initial therapy. The results confirm that periodontal therapy effectively reduces pro-inflammatory cytokines and chemokines, including less well-described mediators that may be important in initiation and progression of periodontitis. The multiplex assay will prove useful for future gingival crevicular fluid studies.

Discovery of new human beta-defensins using a genomics-based approach.

Epithelial beta-defensins are broad-spectrum cationic antimicrobial peptides that also act as chemokines for adaptive immune cells. In the human genome, all known defensin genes cluster to a <1 Mb region of chromosome 8p22-p23. To identify new defensin genes, the DNA sequence from a contig of large-insert genomic clones from the region containing human beta-defensin-2 (HBD-2) was analyzed for the presence of defensin genes. This sequence survey identified a novel beta-defensin, termed HBD-3. The HBD-3 gene contains two exons, is located 13 kb upstream from the HBD-2 gene, and it is transcribed in the same direction. A partial HBD-3 cDNA clone was amplified from cDNA derived from IL-1beta induced fetal lung tissue. The cDNA sequence encodes for a 67 amino acid peptide that is approximately 43% identical to HBD-2 and shares the beta-defensin six cysteine motif. By PCR analysis of two commercial cDNA panels, HBD-3 expression was detected in adult heart, skeletal muscle, placenta and in fetal thymus. From RT-PCR experiments, HBD-3 expression was observed in skin, esophagus, gingival keratinocytes, placenta and trachea. Furthermore, in fetal lung explants and gingival keratinocytes, HBD-3 mRNA expression was induced by IL-1beta. Additional sequence analysis identified the HE2 (human epididymis secretory protein) gene 17 kb upstream from the HBD-3 gene. One splice variant of this gene (HE2beta1) encodes a beta-defensin consensus cysteine motif, suggesting it represents a defensin gene product. HE2beta1 mRNA expression was detected in gingival keratinocytes and bronchial epithelia using RT-PCR analysis. The discovery of these novel beta-defensin genes may allow further understanding of the role of defensins in host immunity at mucosal surfaces.

Efficacy of glove combinations in reducing cell culture infection after glove puncture with needles contaminated with human immunodeficiency virus type 1.

OBJECTIVE: To study the effect of various latex and treated glove combinations in reducing the frequency of human immunodeficiency virus (HIV) infection of tissue culture cells after puncture by surgical needles contaminated with infectious human immunodeficiency virus type 1 (HIV-1). DESIGN: One, two, or three layers of sterile latex glove material, or two latex layers with intermediate cotton or Kevlar (with or without the virucidal compound nonoxynol-9) were used to cover 24-well cell culture dishes containing MT2 cells in cell culture medium. Surgical needles wet with cell culture medium containing HIV-1 (HTLV IIIA strain) were passed through the glove materials into the culture medium in the wells of the culture dishes. The culture medium in each well was then assayed biweekly for HIV-1 p24 antigen as a test for infection of cells in the well. RESULTS: The rate of HIV-1 infection of cell cultures after glove puncture was greater than 90% with a single latex surgical glove barrier, 23% to 60% with double or triple layers of latex gloves, less than 8% with an intermediate cotton glove impregnated with 4% nonoxynol-9, 6% with an intermediate Kevlar glove, and 0% with an intermediate Kevlar glove impregnated with nonoxynol-9. CONCLUSIONS: An intermediate glove of Kevlar or of Kevlar or cotton impregnated with virucidal compound nonoxynol-9 between standard latex gloves may improve surgical glove safety, compared with latex gloves alone with respect to needlestick transmission of HIV-1. The experimental model used may permit rapid investigation of other glove systems as barriers to the transfer of infectious agents through gloves by needlestick.

Clinical experience in 82 patients with pancreas divisum: preliminary results of manometry and endoscopic therapy.

Although it is clear that the majority of patients with pancreas divisum have no clinical disease, there is a subset of patients who have either unexplained abdominal pain or recurrent pancreatitis. Endoscopic therapy of the minor papilla may alter the clinical course of those patients with pancreas divisum and recurrent pancreatitis. Manometric study of the minor papilla is feasible and reveals a sphincter mechanism similar to the major papilla. Clinical response to endoscopic therapy may aid in selecting patients who might benefit from surgical sphincteroplasty. Refinement of manometric study of the minor papilla offers a potential method of detecting functional obstruction of dorsal duct drainage.

Effects of topical and systemic nicotine on gingival blood flow in dogs.

It has been suggested that due to its vasoconstrictive action, nicotine may have a deleterious effect on the periodontium. This study examined the effects of topical and systemic nicotine administration on gingival blood flow. Eighteen young adult dogs were divided into three groups receiving the following treatments for 28 days; topical nicotine in orabase, systemic nicotine via osmotic mini-pumps, and topical orabase or systemic saline via osmotic mini-pumps. Blood flow to the gingiva was measured (at days 0 and 28) by the radiolabeled microsphere method. Blood flow was consistently increased from day 0 to day 28 in the nicotine-treated animals. Comparison of days 0 and 28 blood-flow values demonstrated a statistically significant change (p less than 0.05) in the anterior regions of the topical-nicotine group as compared with the control group. The increased flow may be a reflection of the mode of nicotine delivery and timing of the blood-flow determination procedures.

Differential DNA methylation of the p16 INK4A/CDKN2A promoter in human oral cancer cells and normal human oral keratinocytes.

The p16 INK4A tumor suppressor gene participates in establishing and maintaining the malignant phenotype of a variety of cancer cell lines and primary tumors. Recently it has been observed that p16 expression is lost in oral cavity cancer cell lines in the presence of a normal intact gene. To examine the role of DNA methylation as an explanation for these findings, we analyzed the DNA methylation patterns of the p16 INK4A promoter in DNA isolated from primary cultures of normal human oral keratinocytes and squamous cell carcinoma (SCC-15) oral cancer cells using bisulfite genomic sequencing. Our results demonstrated striking differences in the methylation status of the 5' CpG island of the p16 gene between normal and cancer cells. Normal human oral keratinocytes showed practically no methylation of the p16 INK4A promoter, while SCC-15 oral cancer cells showed almost complete methylation in this region. These data implicate DNA methylation as a mechanism for transcriptional silencing of the p16 INK4A gene in oral cancer cells.

Parapharyngeal neurilemmoma of the hypoglossal nerve.

Although neurilemmomas are uncommon cervical neoplasms, they account for a significant percentage of parapharyngeal space tumors. These neoplasms may originate from any nerve traversing this space, but the vast majority arise from the vagus nerve and sympathetic chain. Satisfactory treatment of neurilemmomas consists of total excision which is best accomplished via an external approach. Immediate nerve grafting is advocated when a segment of cranial nerve must be sacrificed in order to achieve complete tumor removal. A case of a parapharyngeal neurilemmoma arising from the hypoglossal which required treatment in this manner is presented. Electromyographic studies performed 15 months postoperatively demonstrate reinervation of the lingual musculature via the nerve graft.

Clinical effects of closed root planing compared to papilla reflection and fiber optic augmentation.

Mini-surgical approaches in 4 to 7 mm probing depths have been shown to facilitate improved deposit removal as compared to closed instrumentation. At the same time this treatment is less traumatic than more extensive flap reflection for root planing. The purpose of this study was to compare the clinical effects of closed root planing (C/SCRP) to those of root planing augmented by papilla reflection and fiber optic illumination (PR/SCRP) over a 6-month period. Fourteen patients with moderate/advanced adult periodontitis received each therapy in 2 experimental periodontitis sites (PS = greater than or equal to 5 mm probing depth and greater than 5 mm attachment loss) and one non-periodontitis site (NPS = less than or equal to 3 mm probing depth and no recession). Presence of supragingival plaque, bleeding on probing, probing depths, and clinical attachment levels were measured before treatment and 6, 12, and 24 weeks posttreatment. Mean supragingival plaque levels were high and did not vary significantly over the course of the study, but bleeding on probing was significantly reduced in PS following both C/SCRP and PR/SCRP (P less than or equal to 0.0001). Mean probing depths were significantly reduced after 6 months (P less than or equal to 0.01) in NPS-PR/SCRP from 2.8 +/- 0.1 to 2.0 +/- 0.2 mm, in PS-C/SCRP from 5.5 +/- 0.2 to 4.5 +/- 0.4 mm, and in PS-PR/SCRP from 5.8 +/- 0.2 to 3.2 +/- 0.1 mm. In periodontitis sites, PR/SCRP demonstrated greater probing depth reductions than C/SCRP at all time periods (P less than or equal to 0.004). PS attachment levels also improved following C/SCRP and PR/SCRP at all postoperative times (P less than or equal to 0.01). PR/SCRP appears to provide better short-term mean probing depth reduction (2.6 mm) than C/SCRP (1.0 mm), presumably due to apical positioning of the papillae and periodontal repair following improved access for root planing.

Root planing with interdental papilla reflection and fiber optic illumination.

The complete removal of accretions during closed scaling and root planing in moderate-deep pockets is difficult, presumably due to inadequate mechanical and visual access. The purpose of this study was to evaluate the effect of minimal papilla reflection and illumination with a prototype fiber optic unit on root planing efficiency. Nonmolar teeth with moderate-deep interproximal pockets (greater than 3 mm) in four patients scheduled to receive immediate complete dentures were randomly divided into groups for treatment: Group I--interproximal root planing augmented by papilla reflection and fiber optic illumination (n = 26 surfaces); Group II--interproximal root planing with papilla reflection only (n = 24); Group III--untreated controls (n = 23). Immediately after treatment, the experimental teeth were extracted, stained with toluidine blue and interproximal areas were evaluated for remaining accretions with a microscope-digitizing pad-computer system. Significantly less (P less than 0.01) root surface was covered by deposits in Group I than Group II (0.57 +/- 0.29% vs. 2.42 +/- 0.63%), and both treatment groups had fewer (P less than 0.0005) accretions than untreated controls (57.72 +/- 3.40%). These results suggest that root planing with papilla reflection produces an interproximal surface with few remaining deposits, and fiber optic illumination and transillumination further enhance this effect.

Fiber optic probe augmented sonic scaling versus conventional sonic scaling.

Several factors, including access and visualization problems, make total deposit removal during scaling and root planing procedures extremely difficult. This study examined the effectiveness of a mode of therapy designed to improve access and visualization for sonic scaling compared to closed sonic instrumentation. Teeth with moderate to deep probing depths in six patients scheduled to receive immediate dentures were divided into three experimental groups: Group I, sonic scaling with access augmented by interdental papilla reflection and fiber optic illumination/transillumination (34 surfaces); Group II, closed sonic scaling (34 surfaces); and Group III, untreated controls (35 surfaces). Immediately after treatment the experimental teeth were extracted, stained with toluidine blue, and interproximal areas evaluated for remaining accretions with a microscope-digitizing pad-computer system. Group I had a significantly lower percentage (P less than 0.01) of remaining subgingival accretion coverage than Group II (1.30 +/- 0.25% vs 6.35 +/- 1.08%), and both Group I and II demonstrated significantly (P less than 0.01) fewer deposits than the control surfaces (46.61 +/- 4.32%). These findings suggest that minimal tissue reflection and fiber optic illumination/transillumination are beneficial adjuncts to deposit removal in moderate to deep periodontal pockets.

Levels of cigarette consumption and response to periodontal therapy.

Seventy-four patients with moderate to advanced periodontitis were classified by cigarette consumption at the initial exam: heavy smokers (HS) > or = 20 cigarettes/day (n = 31); light smokers (LS) < or = 19 cigarettes/day (n = 15); past smokers (PS) had a history of smoking but had quit by the initial exam (n = 10); and non-smokers (NS) had never smoked (n = 18). All patients were treated with four modalities of periodontal therapy followed by supportive periodontal treatment (SPT) for a period of up to 7 years. Clinical parameters including probing depth (PD), clinical attachment level (CAL), recession (REC), presence of bleeding on probing (BOP), and supragingival plaque (PL) were assessed at six sites around each tooth. Horizontal probing attachment level (HAL) was obtained at molar furcation sites. Data were collected initially, 4 weeks after non-surgical therapy, 10 weeks after surgical therapy, and yearly during SPT. HS and LS demonstrated less PD reduction and less CAL gain than PS and NS following active treatment and throughout SPT. Following active treatment, HAL changes were similar for all groups, but during 7 years of SPT, HS and LS experienced greater loss of HAL. There were no differences in BOP among the four groups. HS demonstrated a higher percentage of PL positive sites compared to the other groups. In summary, HS and LS responded less favorably to therapy than PS and NS. A past history of smoking was not deleterious to the response to therapy.

Effect of smokeless tobacco extract on human gingival keratinocyte levels of prostaglandin E2 and interleukin-1.

Gingival recession and white mucosal lesions frequently occur at sites of smokeless tobacco (ST) placement. The etiology of these alterations is presumably related to the irritating effects of tobacco components. The purpose of this study was to examine the effect of an aqueous ST extract (STE) on gingival keratinocyte production of prostaglandin E2 (PGE2) and interleukin-1 (IL-1), mediators involved in periodontal destruction and keratinocyte proliferation. Keratinocyte cultures were established from healthy tissues discarded from 8 subjects undergoing crown lengthening procedures. Cells (passage 2-3) were seeded at 2.5 x 10(4) cells/well into 48 well tissue culture plates and maintained in serum-free media at 37 degrees C. On day 4 or 5, the wells were divided into 4 groups receiving either 10%, 5%, 2.5%, or 0% STE for time periods ranging from 30 to 240 minutes. PGE2 levels (pg/10(4) cells), as measured by enzyme immunoassay, were significantly (P < 0.05) increased in the 10% (215.66 +/- 34.58) and 5% STE (151.82 +/- 27.97) treated cultures compared to untreated cells (46.16 +/- 9.58). IL-1 alpha and IL-1 beta proteins were elevated (P < 0.05) in cell lysates (299.45 +/- 38.69 and 28.45 +/- 5.18, respectively) from 5% STE exposed cultures compared to control wells. At 10% STE, secreted IL-1 alpha was decreased (P < 0.05) relative to 2.5% STE. This may reflect a toxic effect, as 10% STE significantly (P < 0.05) depressed cell numbers and viability. Lower tobacco concentrations did not affect cell numbers or viability, but significantly (P < 0.05) increased PGE2 and IL-1 levels. Tobacco-induced synthesis of these mediators may play a role in the development of tobacco-related oral disease.

The effects of smokeless tobacco on clinical parameters of inflammation and gingival crevicular fluid prostaglandin E2, interleukin-1 alpha, and interleukin-1 beta.

The purpose of this study was to examine the effect of smokeless tobacco (ST) on gingival inflammation as assessed clinically and biochemically by gingival crevicular fluid (GCF) levels of PGE2, IL-1 alpha, and IL-1 beta. These parameters were compared in ST users (n = 12) and control, non-tobacco using subjects (n = 8) matched for plaque and probing depth levels. Both GI and GCF PGE2 concentration were significantly (P < 0.05) elevated at ST placement sites compared to sites in control subjects. A short-term longitudinal trial spanning 7 days also was undertaken within ST users (n = 18) to study the dynamics of gingival inflammation when ST is moved to a new site. At day 0 habitual ST placement sites exhibited a significantly (P < 0.05) higher GI compared to non-tobacco placement sites. Following transfer of ST to a new placement site, 48 hour GI scores were increased (P < 0.05) at this region. Although GCF parameters were not significantly altered, over 80% of the subjects developed dramatic inflammatory reactions in the alveolar mucosa, ranging from erythema to ulceration, at the new site of placement. This observation of a more severe response in alveolar mucosa compared to gingiva may be related to the physical location of ST or differences in tissue characteristics.

The effects of scaling procedures on epithelial cell growth on titanium surfaces.

This study examined in vitro epithelial cell growth on titanium surfaces which had been instrumented by 3 types of periodontal curets. Commercially pure titanium discs were uniformly scaled using plastic, stainless steel, or gold-coated curets and then seeded with a microdot (50,000 cells per 10 microliters) of rat gingival epithelial cells. After 5 days of growth, epithelial cell surface area (mm2) coverage was measured on photographed specimens using a computer digitizing system. Scanning electron microscopic evaluation showed a denser central core of cellular growth on the stainless steel-treated surfaces as compared to the other surface treatments. Epithelial surface area coverage on the stainless steel, plastic, and control groups did not vary significantly among groups. However the gold-coated curet exposed surfaces supported significantly less epithelial growth than the stainless steel and control surfaces. A better understanding of in vitro epithelial cell responses to different titanium surface characteristics will assist in designing implant scaling procedures which allow maintenance of the implant perimucosal seal.

Smokeless tobacco effects on monocyte secretion of PGE2 and IL-1 beta.

The use of smokeless tobacco (ST) products is associated with mucosal lesions, gingival recession, and attachment loss at the site of tobacco placement. Monocytes/macrophages are primary producers of PGE2 and IL-1 beta, inflammatory mediators which are thought to play a role in the destruction of the periodontium. The purpose of this study was to determine the effect of ST alone and in combination with a major stimulator of inflammation, bacterial lipopolysaccharide (LPS), on monocyte secretion of these mediators. Peripheral blood monocytes (PBM) were isolated by counterflow centrifugal elutriation from 15 healthy donors who were non-ST users. PBM were incubated for 24 hours in RPMI 1640 containing various concentrations of ST (0%, 0.005%, 0.01%, 1%) with or without 10 micrograms/ml LPS (Porphyromonas gingivalis LPS or Escherichia coli LPS). Of the ST preparations, only 1% ST resulted in PBM mediator secretion (7.7 +/- 2.0 ng/ml for PGE2 and 1.3 +/- 0.2 ng/ml for IL-1 beta) above that of control (unstimulated) cultures. Furthermore, the combination of 1% ST and LPS resulted in a potentiation of PGE2 release (5-fold for E. coli LPS + 1% ST and 10-fold for P. gingivalis LPS + 1% ST; P < 0.0001, one-way ANOVA) relative to the LPS preparations alone. In contrast, PBM IL-1 beta release decreased more than 2-fold upon E. coli LPS and 1% ST exposure, relative to treatment with E. coli LPS alone (P < 0.0001, one-way ANOVA).(ABSTRACT TRUNCATED AT 250 WORDS)

Periodontal disease in pregnancy complicated by type 1 diabetes mellitus.

BACKGROUND: Systemic disease and hormonal changes have been implicated as complicating factors for periodontal disease. Diabetes has been identified as a risk factor for periodontal disease, and diabetics can experience periodontal destruction at an earlier age than non-diabetic individuals. Increased hormone levels during pregnancy can contribute to increased gingival inflammation. The purpose of this study was to examine the association of type 1 diabetes mellitus (DM) on the periodontal status of pregnant women. METHODS: Thirty-three (13 diabetic and 20 non-diabetic) subjects, 20 to 39 weeks gestation, participated in this study. The mean age of the diabetics and non-diabetics was 28.5 +/- 7.1 (SD) and 27.0 +/- 7.3 years, respectively. The following parameters were assessed at Ramfjord's reference teeth: plaque index (PI), gingival inflammation (GI), probing depth (PD), gingival margin (GM) location, and clinical attachment level (CAL). RESULTS: Diabetic subjects had significantly (P<0.001) higher PI (1.48 +/- 0.69) and GI (1.77 +/- 0.44) scores than non-diabetics (PI = 0.63 +/- 0.38; GI = 0.93 +/- 0.48). Mean PD for diabetics (2.95 +/- 0.69 mm) was significantly different (P<0.024) from that of non-diabetics (2.44 +/- 0.32 mm). Although mean GM location was coronal to the cemento-enamel junction (CEJ) in both groups, gingival margins were at a more apical position (P<0.001) in the diabetics (-0.20 +/- 1.24 mm) compared to non-diabetics (-1.76 +/- 0.53 mm). Mean CAL values also varied significantly (P<0.001) between diabetics (2.60 +/- 1.54 mm) and non-diabetics (0.68 +/- 0.65 mm). Significant differences were seen for GI (P<0.001), PD (P=0.005), GM location (P<0.001), and CAL (P<0.001) when assessing the effect of diabetes and controlling for plaque. When assessing the effect of plaque and controlling for diabetes, the only significant difference was GI (P=0.001). CONCLUSIONS: The results of this study demonstrate that periodontal inflammation and destruction are increased in pregnant diabetics as compared to non-diabetic pregnant patients. These findings may have implications for diabetic control and, hence, maternal and fetal outcomes in pregnant diabetic patients.

Treatment of periodontitis by local administration of minocycline microspheres: a controlled trial.

BACKGROUND: Periodontitis is an inflammatory condition of tooth-supporting tissues that is usually treated by mechanical removal of plaque and microorganisms that adhere to teeth. This treatment, known as scaling and root planing, is not optimally effective. Adjunctive therapy with locally delivered antimicrobials has resulted in improved clinical outcomes such as probing depth reduction. This article reports on the efficacy and safety of locally administered microencapsulated minocycline. METHODS: Seven hundred forty-eight (748) patients with moderate to advanced periodontitis were enrolled in a multi-center trial and randomized to 1 of 3 treatment arms: 1) scaling and root planing (SRP) alone; 2) SRP plus vehicle; or 3) SRP plus minocycline microspheres. The primary outcome measure was probing depth reduction at 9 months. Clinical assessments were performed at baseline and 1, 3, 6, and 9 months. RESULTS: Minocycline microspheres plus scaling and root planing provided substantially more probing depth reduction than either SRP alone or SRP plus vehicle. The difference reached statistical significance after the first month and was maintained throughout the trial. The improved outcome was observed to be independent of patients' smoking status, age, gender, or baseline disease level. There was no difference in the incidence of adverse effects among treatment groups. CONCLUSIONS: Scaling and root planing plus minocycline microspheres is more effective than scaling and root planing alone in reducing probing depths in periodontitis patients.

Comparison of differentiation markers between normal and two squamous cell carcinoma cell lines in culture.

This study examines differences between cultures of normal human oral epithelial cells and two squamous cell carcinoma cell lines (SCC15 and SCC25) in the expression of structural proteins, adhesion molecules, plasma membrane lipid composition, and intercellular junctions. Based on immunocytochemistry, most normal cell cultures appeared to express more E-cadherin, integrin beta-1, cytokeratin (CK) 14, CK19, and involucrin than SCC cultures. By Western blot analysis, normal cultures expressing high levels of E-cadherin also expressed high levels of involucrin and low levels of CK19. Both SCC cultures demonstrated lower expression of E-cadherin and involucrin, whereas only SCC15 cells showed high levels of CK19. Expression of beta-catenin, an E-cadherin associated protein with potential oncogene function, did not vary among normal and SCC cells. Proportions of saturated fatty acids quantified by thin layer chromatography were higher in the normal cell cultures, than in both SCC cell lines. No morphological differences were evident by transmission electron microscopy (TEM) between normal and SCC cell-cell intercellular junctions. Although no quantitation was attempted, observation suggested that normal cells form more intercellular junctions (TEM observation) and larger intercellular bridges (SEM observation) compared to both SCC cell lines. Of the factors examined, main variations between cultures of normal oral epithelium and the two SCC cell lines examined include the expression of structural and adhesion proteins, lipid composition, and intercellular junctions. The extent of the differences varies according to the stage of terminal differentiation demonstrated by the normal cell cultures.

Epidemiology of Sarcocystis neurona infections in domestic cats (Felis domesticus) and its association with equine protozoal myeloencephalitis (EPM) case farms and feral cats from a mobile spay and neuter clinic.

Equine protozoal myeloencephalitis (EPM) is a serious neurologic disease in the horse most commonly caused by Sarcocystis neurona. The domestic cat (Felis domesticus) is an intermediate host for S. neurona. In the present study, nine farms, known to have prior clinically diagnosed cases of EPM and a resident cat population were identified and sampled accordingly. In addition to the farm cats sampled, samples were also collected from a mobile spay and neuter clinic. Overall, serum samples were collected in 2001 from 310 cats, with samples including barn, feral and inside/outside cats. Of these 310 samples, 35 were from nine horse farms. Horse serum samples were also collected and traps were set for opossums at each of the farms. The S. neurona direct agglutination test (SAT) was used for both the horse and cat serum samples (1:25 dilution). Fourteen of 35 (40%) cats sampled from horse farms had circulating S. neurona agglutinating antibodies. Twenty-seven of the 275 (10%) cats from the spay/neuter clinic also had detectable S. neurona antibodies. Overall, 115 of 123 (93%) horses tested positive for anti-S. neurona antibodies, with each farm having greater than a 75% exposure rate among sampled horses. Twenty-one opossums were trapped on seven of the nine farms. Eleven opossums had Sarcocystis sp. sporocysts, six of them were identified as S. neurona sporocysts based on bioassays in gamma-interferon gene knockout mice with each opossum representing a different farm. Demonstration of S. neurona agglutinating antibodies in domestic and feral cats corroborates previous research demonstrating feral cats to be naturally infected, and also suggests that cats can be frequently infected with S. neurona and serve as one of several natural intermediate hosts for S. neurona.