A randomized, controlled clinical trial on the clinical, microbiological, and staining effects of a novel 0.05% chlorhexidine/herbal extract and a 0.1% chlorhexidine mouthrinse adjunct to periodontal surgery

BACKGROUND: Chlorhexidine (CHX) rinsing after periodontal surgery is common. We assessed the clinical and microbiological effects of two CHX concentrations following periodontal surgery. MATERIALS AND METHODS: In a randomized, controlled clinical trial, 45 subjects were assigned to 4 weeks rinsing with a 0.05 CHX/herbal extract combination (test) or a 0.1% CHX solution. Clinical and staining effects were studied. Subgingival bacteria were assessed using the DNA-DNA checkerboard. Statistics included parametric and non-parametric tests (p<0001 to declare significance at 80% power). RESULTS: At weeks 4 and 12, more staining was found in the control group (p<0.05 and p<0.001, respectively). A higher risk for staining was found in the control group (crude OR: 2.3:1, 95% CI: 1.3 to 4.4, p<0.01). The absolute staining reduction in the test group was 21.1% (9 5% CI: 9.4-32.8%). Probing pocket depth (PPD) decreases were significant (p<0.001) in both groups and similar (p=0.92). No rinse group differences in changes of bacterial counts for any species were found between baseline and week 12. CONCLUSIONS: The test CHX rinse resulted in less tooth staining. At the study endpoint, similar and high counts of periodontal pathogens were found.

Periodontitis: a future risk of acute coronary syndrome? A follow-up study over 3 years

BACKGROUND: Periodontitis has been associated with cardiovascular disease. We assess if the recurrence of acute coronary syndrome (ACS) could be predicted by preceding medical and periodontal conditions. METHODS: A total of 165 consecutive subjects with ACS and 159 medically healthy, matched control subjects were examined and followed for 3 years. Periodontitis was defined by alveolar bone loss. Subgingival microbial samples were studied by the checkerboard DNA-DNA hybridization method. RESULTS: The recurrence of ACS was found in 66 of 165 (40.0%) subjects, and a first ACS event was found in seven of 159 (4.4%) subjects among baseline control subjects. Subjects who later had a second ACS event were older (P <0.001). Significantly higher serum levels of high-density lipoprotein (P <0.05), creatinine (P <0.01), and white blood cell (WBC) counts (P <0.001) were found in subjects with future ACS. Periodontitis was associated with a first event of ACS (crude odds ratio [OR]: 10.3:1; 95% confidence interval [CI]: 6.1 to 17.4; P <0.001) and the recurrence of ACS (crude OR: 3.6:1; 95% CI: 2.0 to 6.6; P <0.001). General linear modeling multivariate analysis, controlling for age and the prediction of a future ACS event, identified that WBC counts (F = 20.6; P <0.001), periodontitis (F = 17.6; P <0.001), and serum creatinine counts (F = 4.5; P <0.05) were explanatory of a future ACS event. CONCLUSIONS: The results of this study indicate that recurrent ACS events are predicted by serum WBC counts, serum creatinine levels, and a diagnosis of periodontitis. Significantly higher counts of putative pathogens are found in subjects with ACS, but these counts do not predict future ACS events.

Periodontal pathogens affect the level of protease inhibitors in gingival crevicular fluid

In periodontitis, an effective host-response is primarily related to neutrophils loaded with serine proteases, including elastase (NE) and protease 3 (PR3), the extracellular activity of which is tightly controlled by endogenous inhibitors. In vitro these inhibitors are degraded by gingipains, cysteine proteases produced by Porphyromonas gingivalis. The purpose of this study was to determine the level of selected protease inhibitors in gingival crevicular fluid (GCF) in relation to periodontal infection. The GCF collected from 31 subjects (nine healthy controls, seven with gingivitis, five with aggressive periodontitis and 10 with chronic periodontitis) was analyzed for the levels of elafin and secretory leukocyte protease inhibitor (SLPI), two main tissue-derived inhibitors of neutrophil serine proteases. In parallel, activity of NE, PR3 and arginine-specific gingipains (Rgps) in GCF was measured. Finally loads of P. gingivalis, Aggregatibacter actinomycetemcomitans, Tannerella forsythia and Treponema denticola were determined. The highest values of elafin were found in aggressive periodontitis and the lowest in controls. The quantity of elafin correlated positively with the load of P. gingivalis, Ta. forsythia and Tr. denticola, as well as with Rgps activity. In addition, NE activity was positively associated with the counts of those bacterial species, but not with the amount of elafin. In contrast, the highest concentrations of SLPI were found in periodontally healthy subjects whereas amounts of this inhibitor were significantly decreased in patients infected with P. gingivalis. Periodontopathogenic bacteria stimulate the release of NE and PR3, which activities escape the control through degradation of locally produced inhibitors (SLPI and elafin) by host-derived and bacteria-derived proteases.

Proteomic and peptidomic study of proteolysis in quarter milk after infusion with lipoteichoic acid from Staphylococcus aureus

Mastitic milk is associated with increased bovine protease activity, such as that from plasmin and somatic cell enzymes, which cause proteolysis of the caseins and may reduce cheese yield and quality. The aim of this work was to characterize the peptide profile resulting from proteolysis in a model mastitis system and to identify the proteases responsible. One quarter of each of 2 cows (A and B) was infused with lipoteichoic acid from Staphylococcus aureus. The somatic cell counts of the infused quarters reached a peak 6h after infusion, whereas plasmin activity of those quarters also increased, reaching a peak after 48 and 12h for cow A and B, respectively. Urea-polyacrylamide gel electrophoretograms of milk samples of cow A and B obtained at different time points after infusion and incubated for up to 7 d showed almost full hydrolysis of beta- and alpha(S1)-casein during incubation of milk samples at peak somatic cell counts, with that of beta-casein being faster than that of alpha(S1)-casein. Two-dimensional gel electrophoretograms of milk 6h after infusion with the toxin confirmed hydrolysis of beta- and alpha(S1)-casein and the appearance of lower-molecular-weight products. Peptides were subsequently separated by reversed-phase HPLC and handmade nanoscale C(18) columns, and identified by matrix-assisted laser desorption/ionization time-of-flight tandem mass spectrometry. Twenty different peptides were identified and shown to originate from alpha(s1)- and beta-casein. Plasmin, cathepsin B and D, elastase, and amino- and carboxypeptidases were suggested as possible responsible proteases based on the peptide cleavage sites. The presumptive activity of amino- and carboxypeptidases is surprising and may indicate the activity of cathepsin H, which has not been reported in milk previously.

Determinants of hepatitis A vaccine immunity in a cohort of human immunodeficiency virus-infected children living in Switzerland

Vaccination in HIV-infected children is often less effective than in healthy children. The goal of this study was to assess vaccine responses to hepatitis A virus (HAV) in HIV-infected children. Children of the Swiss Mother and Child HIV Cohort Study (MoCHiV) were enrolled prospectively. Recommendations for initial, catch-up, and additional HAV immunizations were based upon baseline antibody concentrations and vaccine history. HAV IgG was assessed by enzyme-linked immunosorbent assay (ELISA) with a protective cutoff value defined as ≥10 mIU/ml. Eighty-seven patients were included (median age, 11 years; range, 3.4 to 21.2 years). Forty-two patients were seropositive (48.3%) for HAV. Among 45 (51.7%) seronegative patients, 36 had not received any HAV vaccine dose and were considered naïve. Vaccine responses were assessed after the first dose in 29/35 naïve patients and after the second dose in 33/39 children (25 initially naïve patients, 4 seronegative patients, and 4 seropositive patients that had already received 1 dose of vaccine). Seroconversion was 86% after 1 dose and 97% after 2 doses, with a geometric mean concentration of 962 mIU/ml after the second dose. A baseline CD4(+) T cell count below 750 cells/μl significantly reduced the post-2nd-dose response (P = 0.005). Despite a high rate of seroconversion, patients with CD4(+) T cell counts of <750/μl had lower anti-HAV antibody concentrations. This may translate into a shorter protection time. Hence, monitoring humoral immunity may be necessary to provide supplementary doses as needed.

Risks of non-accidental mortality by baseline CD4+ T-cell strata in hepatitis-C-positive and -negative individuals initiating highly active antiretroviral therapy

BACKGROUND: Patients coinfected with hepatitis C virus (HCV) and HIV experience higher mortality rates than patients infected with HIV alone. We designed a study to determine whether risks for later mortality are similar for HCV-positive and HCV-negative individuals when subjects are stratified on the basis of baseline CD4+ T-cell counts. METHODS: Antiretroviral-naive individuals, who initiated highly active antiretroviral therapy (HAART) between 1996 and 2002 were included in the study. HCV-positive and HCV-negative individuals were stratified separately by baseline CD4+ T-cell counts of 50 cell/microl increments. Cox-proportional hazards regression was used to model the effect of these strata with other variables on survival. RESULTS: CD4+ T-cell strata below 200 cells/microl, but not above, imparted an increased relative hazard (RH) of mortality for both HCV-positive and HCV-negative individuals. Among HCV-positive individuals, after adjustment for baseline age, HIV RNA levels, history of injection drug use and adherence to therapy, only CD4+ T-cell strata of <50 cells/microl (RH=4.60; 95% confidence interval [CI] 2.72-7.76) and 50-199 cells/microl (RH=2.49; 95% CI 1.63-3.81) were significantly associated with increased mortality when compared with those initiating therapy at cell counts >500 cells/microl. The same baseline CD4+ T-cell strata were found for HCV-negative individuals. CONCLUSION: In a within-groups analysis, the baseline CD4+ T-cell strata that are associated with increased RHs for mortality are the same for HCV-positive and HCV-negative individuals initiating HAART. However, a between-groups analysis reveals a higher absolute mortality risk for HCV-positive individuals.

Characterization of retinal damage in the episcleral vein cauterization rat glaucoma model

Episcleral vein cauterization (EVC) is used in rats to generate a glaucoma model with high intraocular pressure (IOP). The long-term retinal damage in this glaucoma model, however, has not been accurately quantified. We report the location and amount of retinal ganglion cell (RGC) damage caused by (EVC) induced IOP elevation in two rat strains. IOP was raised in one eye of Wistar (N = 5) and Brown-Norway(B-N)(N = 7) rats by EVC and monitored monthly until IOP in contralateral eyes equalized at 5 months post-surgery. Animals were maintained for 3.5-4.5 additional months. B-N rats (N = 7) that had no EVC served as controls for this strain. Scotopic flash ERGs were recorded at baseline and just prior to euthanasia. Automated counts of all retrogradely labeled RGCs in retinal flat-mounts were determined and compared between contralateral eyes. RGC density maps were constructed and RGC size distribution was determined. Oscillatory potentials in the group of eyes which had elevated IOP were decreased at the time of euthanasia, when IOP had returned to normal. The group of normal B-N rats had similar RGC counts between contralateral eyes. In the experimental group the mean number of RGCs was not significantly different between control and experimental eyes, but 1 of 5 Wistar and 2 of 7 B-N experimental eyes had at least 30% fewer RGCs than contralateral control eyes. Total retinal area in B-N experimental eyes was higher compared to contralateral eyes. Cumulative IOP exposure of the experimental eyes was modestly correlated with RGC loss while oscillatory potentials appeared to be inversely related to RGC loss. In retinas with extensive (> 30% RGC loss) but not complete damage, smaller cells were preserved better than larger ones. The above results indicate that RGC loss in both Wistar and B-N strains is variable after a prolonged elevation of IOP via EVC. Such variability despite equivalent IOP levels and ERG abnormalities, suggests unknown factors that can protect IOP-stressed RGCs. Identification and enhancement of such factors could prove useful for glaucoma therapy.

Microbial colonization patterns predict the outcomes of surgical treatment of intrabony defects

AIM: To explore the impact of bacterial load and microbial colonization patterns on the clinical outcomes of periodontal surgery at deep intrabony defects. MATERIALS AND METHODS: One hundred and twenty-two patients with advanced chronic periodontitis and at least one intrabony defect of >3 mm were recruited in 10 centres. Before recruitment, the infection control phase of periodontal therapy was completed. After surgical access and debridement, the regenerative material was applied in the test subjects, and omitted in the controls. At baseline and 1 year following the interventions, clinical attachment levels (CAL), pocket probing depths (PPD), recession (REC), full-mouth plaque scores and full-mouth bleeding scores were assessed. Microbial colonization of the defect-associated pocket was assessed using a DNA-DNA checkerboard analysis. RESULTS: Total bacterial load and counts of red complex bacteria were negatively associated with CAL gains 1 year following treatment. The probability of achieving above median CAL gains (>3 mm) was significantly decreased by higher total bacterial counts, higher red complex and T. forsythensis counts immediately before surgery. CONCLUSIONS: Presence of high bacterial load and specific periodontal pathogen complexes in deep periodontal pockets associated with intrabony defects had a significant negative impact on the 1 year outcome of surgical/regenerative treatment.

One-year bacterial colonization patterns of Staphylococcus aureus and other bacteria at implants and adjacent teeth

AIMS: (i) To assess the pattern of early bacterial colonization on titanium oral implants after installation, at 12 weeks and at 12 months, (ii) to compare the microbiota at submucosal implant sites and adjacent subgingival tooth sites and (iii) to assess whether or not early colonization was predictive of 12-month colonization patterns. MATERIAL AND METHODS: Submucosal/subgingival plaque samples from 17 titanium oral implants and adjacent teeth were analyzed by checkerboard DNA-DNA hybridization 30 min, 12 weeks and 12 months after implant installation. RESULTS: At 12 months, none of the inserted implants had been lost or presented with signs of peri-implantitis. The distribution of sites at implants and teeth with bleeding on probing varied between 2% and 11%. Probing pocket depths < or =3 mm were found at 75% of implant sites. At 12 months, the sum of the bacterial counts of 40 species was statistically significantly higher at tooth compared with implant sites (mean difference: 34.4 x 10(5), 95% confidence interval -0.4 to 69.4, P<0.05). At 12 months, higher individual bacterial counts at tooth sites were found for 7/40 species compared with implant sites. Detection or lack of detection of Staphylococcus aureus at implant sites at 12 weeks resulted in the highest positive (e.g. 80%) and negative (e.g. 90%) predictive values, respectively. Between 12 weeks and 12 months, the prevalence of Tannerella forsythia increased statistically significantly at implant sites (P<0.05). Lack of detection of Porphyromonas gingivalis at 12 weeks yielded a negative predictive value of 93.1% of this microorganism being undetectable at implant sites at 12 months. CONCLUSIONS: Within the limits of this study, the findings showed (i) a few differences in the prevalence of bacterial species between implant and adjacent tooth sites at 12 months and (ii) high positive and negative predictive values for selected bacterial species.

Durability and outcome of initial antiretroviral treatments received during 2000--2005 by patients in the Swiss HIV Cohort Study

BACKGROUND: Little is known about time trends, predictors, and consequences of changes made to antiretroviral therapy (ART) regimens early after patients initially start treatment. METHODS: We compared the incidence of, reasons for, and predictors of treatment change within 1 year after starting combination ART (cART), as well as virological and immunological outcomes at 1 year, among 1866 patients from the Swiss HIV Cohort Study who initiated cART during 2000--2001, 2002--2003, or 2004--2005. RESULTS: The durability of initial regimens did not improve over time (P = .15): 48.8% of 625 patients during 2000--2001, 43.8% of 607 during 2002--2003, and 44.3% of 634 during 2004--2005 changed cART within 1 year; reasons for change included intolerance (51.1% of all patients), patient wish (15.4%), physician decision (14.8%), and virological failure (7.1%). An increased probability of treatment change was associated with larger CD4+ cell counts, larger human immunodeficiency virus type 1 (HIV-1) RNA loads, and receipt of regimens that contained stavudine or indinavir/ritonavir, but a decreased probability was associated with receipt of regimens that contained tenofovir. Treatment discontinuation was associated with larger CD4+ cell counts, current use of injection drugs, and receipt of regimens that contained nevirapine. One-year outcomes improved between 2000--2001 and 2004--2005: 84.5% and 92.7% of patients, respectively, reached HIV-1 RNA loads of <50 copies/mL and achieved median increases in CD4+ cell counts of 157.5 and 197.5 cells/microL, respectively (P < .001 for all comparisons). CONCLUSIONS: Virological and immunological outcomes of initial treatments improved between 2000--2001 and 2004--2005, irrespective of uniformly high rates of early changes in treatment across the 3 study intervals.