A systematic review and meta-analyses on C-reactive protein in relation to periodontitis

AIM

Elevated plasma C-reactive protein (CRP) is regarded as a risk predictor for cardiovascular diseases. This systematic review explored the robustness of observations that CRP is elevated in periodontitis. Similarly, the effect of periodontal therapy on CRP levels was investigated.

MATERIAL AND METHODS

Selection of publications was based on: (1) cross-sectional (case-control) studies; (2) longitudinal (treatment) studies; (3) high-sensitivity CRP measurement; (4) median and/or mean (+/-SD) values presented; and (5) subjects with no systemic disorders.

RESULTS

Screening of the initially 448 identified studies and reference checking resulted in 18 suitable papers. The majority of the studies showed that CRP levels are higher in patients than in controls. Often, studies showed that patients had CRP levels >2.1 mg/l. A meta-analysis of 10 cross-sectional studies showed that the weighted mean difference (WMD) of CRP between patients and controls was 1.56 mg/l (p<0.00001). Evidence from available treatment studies (n=6) showed lower levels of CRP after periodontal therapy. Eligible treatment studies in a meta-analysis demonstrated a WMD of reductions of CRP after therapy of 0.50 mg/L (95% CI 0.08-0.93) (p=0.02).

CONCLUSIONS

There is strong evidence from cross-sectional studies that plasma CRP in periodontitis is elevated compared with controls. There is modest evidence on the effect of periodontal therapy in lowering the levels of CRP.

A randomized, multicenter study of steroid avoidance, early steroid withdrawal or standard steroid therapy in kidney transplant recipients

In a randomized, open-label, multicenter study, de novo renal transplant patients received no steroids (n = 112), steroids to day 7 (n = 115), or standard steroids (n = 109) with cyclosporine microemulsion (CsA-ME), enteric-coated mycophenolate sodium (EC-MPS) and basiliximab. The primary objective, to demonstrate noninferiority of 12-month GFR in the steroid-free or steroid-withdrawal groups versus standard steroids, was not met in the intent-to-treat population. However, investigational groups were not inferior to standard steroids in the observed-case analysis. Median 12-month GFR was not significantly different in the steroid-free or steroid-withdrawal groups (58.6 mL/min/1.73 m(2) and 59.1 mL/min/1.73 m(2)) versus standard steroids (60.8 mL/min/1.73 m(2)). The 12-month incidence of biopsy-proven acute rejection (BPAR), graft loss or death was 36.0% in the steroid-free group (p = 0.007 vs. standard steroids), 29.6% with steroid withdrawal (N.S.) and 19.3% with standard steroids. BPAR was significantly less frequent with standard steroids than either of the other two regimens. Reduced de novo use of antidiabetic and lipid-lowering medication, triglycerides and weight gain were observed in one or both steroid-minimization group versus standard steroids. For standard-risk renal transplant patients receiving CsA-ME, EC-MPS and basiliximab, steroid withdrawal by the end of week 1 achieves similar 1-year renal function to a standard-steroids regimen, and may be more desirable than complete steroid avoidance.

Cell loss in isolated human islets occurs by apoptosis

Purified islet allografts have largely failed to maintain long-term glucose homeostasis in human recipients, and the reasons for this are unclear. It is noteworthy, however, that islet isolation destroys or removes cellular and noncellular elements of the pancreas that could play an important role in supporting islet survival. The purpose of this study was to determine whether human islet isolation leads to the induction of programmed cell death. Human islets were enzymatically isolated from cadaveric donor pancreata using Liberase or Collagenase P, purified over a discontinuous BSA gradient, then cultured in RPMI 1640 at 37 degrees C in 5% CO2 for < or = 7 days. Islets were examined daily by routine histology and immunocytochemistry for islet hormones, DNA fragmentation [cell death; enzyme-linked immunosorbent assay (ELISA) and TUNEL assay] and for transglutaminase (TG) activity, two indicators of apoptosis. TG activity and DNA fragmentation increased by 1,000% and 1,890%, respectively (p < 0.05) This corresponded to the appearance of pyknotic nuclei on light microscopy, the presence of apoptotic bodies on electron microscopy, and the demonstration of TUNEL-positive cells. These were present primarily in a distribution that corresponded to the insulin-immunoreactive cells. At 5 days, 31.4 +/- 2.2% of islet cells were TUNEL positive. In summary, apoptosis of islet cells appears soon after islet isolation, and involves primarily the beta cell. This is the first report of apoptosis of islet cells after human islet isolation. The loss of beta-cell mass could be implicated in the failure of islet transplantation and merits further investigation.

Structural and functional changes resulting from islet isolation lead to islet cell death

BACKGROUND

Islet isolation exposes the islet to a variety of cellular stresses and disrupts the cell-matrix relationship--events known to be associated with apoptosis. The purpose of this study was to determine whether islet isolation leads invariably to islet cell death and to specify the mechanisms involved.

METHODS

Canine islets were isolated using Liberase CI and purified using a centrifuge. Islets were sampled for up to 5 days in culture and analyzed by routine histology, electron microscopy, immunocytochemistry, and reticulin staining for basement membrane. Apoptosis was assessed by cell death enzyme-linked immunosorbent assay and terminal deoxynucleotidyl transferase-mediated decoxyuridine triphosphate nick and labeling (TUNEL) assay. Activation of the prosurvival ERK1/2 and proapoptotic p38 and JNK were determined by immunoblotting.

RESULTS

Immediately after isolation, the peri-insular basement membrane was absent, and integrin-alpha 5 expression diminished. DNA fragmentation rose from 2.5 +/- 1.8 (arbitrary units) on the day of isolation to 42.4 +/- 6.7 48 hours later (P < .05), coinciding with the appearance of pyknotic nuclei and apoptotic bodies. The apoptotic index determined by TUNEL assay increased from 5% +/- 1% on the day of isolation to 60% +/- 2% on day 5 (P < .01), and most of the affected cells were beta-cells. Finally, the p38 and JNK activity were elevated relative to ERK1/2.

CONCLUSIONS

During isolation, islet cells undergo profound changes in structure and function, resulting in beta-cell apoptosis. These findings suggest that strategies directed to the manipulation of the cell-matrix relationship and the modulation of mitogen-activated protein kinase signal transduction may offer a valuable new approach to improving islet transplant outcome.

The long-term effect of a mouthrinse containing essential oils on dental plaque and gingivitis: a systematic review

BACKGROUND

The purpose of this study was to review the literature on the effects of a mouthrinse containing essential oils (EO) on plaque and parameters of gingival inflammation.

METHODS

The MEDLINE and Cochrane Central Register of Controlled Trials were searched up to and including December 2006 to identify appropriate studies. The primary outcome measure was gingivitis. Secondary parameters were plaque and, when reported, staining.

RESULTS

Independent screening of titles and abstracts of 566 papers resulted in 11 publications that met the criteria of eligibility. In all studies, EO was used as an adjunct to regular daily toothbrushing. A statistically significant reduction in overall gingivitis was noted compared to the control (weighted mean difference [WMD]: -0.32, 95% confidence interval [CI]: -0.46 to -0.19, P <0.00001; test for heterogeneity: P <0.00001, I(2) = 96.7%). For interproximal sites the use of the test mouthrinse resulted in significantly more gingivitis reduction compared to control mouthrinse (WMD: -0.29, 95% CI: -0.48 to -0.11, P = 0.002; test for heterogeneity: P <0.00001, I(2) = 95.18%), whereas no differences were observed compared to dental floss. With respect to plaque scores, EO produced significant overall reductions in plaque (WMD: -0.83, 95% CI: -1.13 to -0.53, P <0.00001; test for heterogeneity: P <0.00001, I(2) = 96.1%). Separate analysis for interproximal areas revealed that EO resulted in more pronounced plaque drops compared to the control mouthrinse (WMD: -1.02, 95% CI: -1.44 to -0.60, P <0.00001; test for heterogeneity: P <0.00001, I(2) = 96.1%) or the use of floss (WMD: -0.75, 95% CI: -1.15 to -0.363, P <0.0002; test for heterogeneity: P <0.0002, I(2) = 93.0%). Most studies agreed that EO did not produce more staining than the control products.

CONCLUSION

When used as an adjunct to unsupervised oral hygiene, EO provides an additional benefit with regard to plaque and gingivitis reduction as compared to a placebo or control.

Characterization of integrin expression in islets isolated from hamster, canine, porcine, and human pancreas

The reasons for the failure of clinical islet transplantation remain obscure. Islet isolation, however, exposes the islet to variety of cellular stresses, including disruption of the cell-matrix relationship, an event associated with apoptosis. The cell-matrix relationship is characterized by an interaction between cell surface integrin receptors and matrix molecules of the surrounding basement membrane (BM). The purpose of this study was to characterize integrin expression and the distribution of the peri-insular BM in human, porcine, canine, and hamster pancreas, and after routine islet isolation. Whereas islets in the porcine pancreas do not have a demonstrable BM, islets in the human, canine, and hamster pancreas have an almost continuous BM with very little direct exocrine to endocrine cell-cell contact. After islet isolation, the BM was destroyed, only to be reestablished during the period of culture. In the pancreas of all four species, integrin alpha3 was expressed only on islet cells, and integrin alpha5 was present on islet cells as well as on acinar, centroacinar, and duct cells. Integrin alphaV was detected only in human and canine pancreas. Integrin beta1 was demonstrated only in the human pancreas. In isolated islets, integrin alpha3, alpha5, and alphaV expression decreased during the culture period and the intensity of the staining was observed to be coincident with the distribution of the BM. In summary, this is the first report of integrin expression in hamster, canine, porcine, and human islets. After islet isolation, the altered islet cell-matrix relationship is reflected both in the decrease in integrin expression and in the destruction of the peri-insular BM. These profound changes will need to be considered as the process of islet isolation for transplantation is refined. (J Histochem Cytochem 47:499-506, 1999)

Transdifferentiation of human islets to pancreatic ductal cells in collagen matrix culture

Transdifferentiation is a change from one differentiated phenotype to another, involving morphological and functional phenotypic markers. Stability of the cellular phenotype is probably related to the extracellular milieu, as well as cytoplasmic and nuclear components that interact to control gene expression, and the conversion of cell phenotype is likely to be accomplished by selective enhancement of gene expression, which controls the terminal developmental commitment of cells. In this paper, we show the induction of cultured human islets cells to alter their usual phenotypic expression and attain morphological and functional characteristics of duct cells. Islets were isolated by collagenase digestion of pancreata that were removed from cadaveric organ donors. The islets were purified on a two-step density gradient of bovine serum albumin and were then placed into a three-dimensional rat-tail collagen gel matrix supplemented with NuSerum epithelial growth factor and cholera toxin. During the initial 96 h of culture, the islets underwent a cystic transformation that was associated with (1) the maintenance of immunoreactivity for neuron-specific enolase, an endocrine cell marker, but a progressive loss of insulin gene expression, (2) a loss of immunoreactivity for insulin protein, and (3) the appearance of CK-19, a marker for ductal cells. After the transformation was complete, the cells had the ultrastructural appearance of primitive duct-like cells. Cyst enlargement after the initial 96 h was associated, at least in part, with cell replication, as reflected in the 1500% increase in the incorporation of tritiated thymidine. These experiments are consistent with the transdifferentiation of an islet cell to a ductal cell. The exact mechanisms involved still need to be fully elucidated.

Guidelines for the diagnosis of antibody-mediated rejection in pancreas allografts-updated Banff grading schema

The first Banff proposal for the diagnosis of pancreas rejection (Am J Transplant 2008; 8: 237) dealt primarily with the diagnosis of acute T-cell-mediated rejection (ACMR), while only tentatively addressing issues pertaining to antibody-mediated rejection (AMR). This document presents comprehensive guidelines for the diagnosis of AMR, first proposed at the 10th Banff Conference on Allograft Pathology and refined by a broad-based multidisciplinary panel. Pancreatic AMR is best identified by a combination of serological and immunohistopathological findings consisting of (i) identification of circulating donor-specific antibodies, and histopathological data including (ii) morphological evidence of microvascular tissue injury and (iii) C4d staining in interacinar capillaries. Acute AMR is diagnosed conclusively if these three elements are present, whereas a diagnosis of suspicious for AMR is rendered if only two elements are identified. The identification of only one diagnostic element is not sufficient for the diagnosis of AMR but should prompt heightened clinical vigilance. AMR and ACMR may coexist, and should be recognized and graded independently. This proposal is based on our current knowledge of the pathogenesis of pancreas rejection and currently available tools for diagnosis. A systematized clinicopathological approach to AMR is essential for the development and assessment of much needed therapeutic interventions.

Rapid discontinuation of steroids in living donor kidney transplantation: a pilot study

Steroids are associated with significant postoperative complications (hypertension, cosmetic changes, bone loss, hyperlipidemia, diabetes, and cataracts). Most develop early; in addition, late post-transplant steroid withdrawal in kidney transplant recipients has been associated with increased acute rejection (AR). To obviate these problems, we studied outcome of a protocol of rapid discontinuation of prednisone (RDS) (steroids stopped on POD6). Between November 1, 1999 and October 31, 2000, 51 adult living donor (LD) first transplant recipients (2 HLA-id, 28 non-id relative, 21 LURD) were immunosuppressed with thymoglobulin (1.25 mg/kg intraoperatively and then qdx4); prednisone (P) (500 mg methylprednisolone intraoperatively, 1 mg/kg x 1 day, 0.5 mg/kg x 2 days, 0.25 mg/kg x 2 days, then d/c); MMF, 1 g b.i.d.; and CSA, 4 mg/kg b.i.d. adjusted to achieve levels of 150-200 ng/mL (by HPLC). Exclusion criteria were delayed graft function or primary disease requiring P. Minimum follow-up was 5.5 months (range 5.5 to 17.5 months). Outcome was compared vs. previous cohorts of LD recipients immunosuppressed with P/AZA/CSA (n = 171) or P/MMF/CSA (n = 43) (both without antibody induction).

RESULTS

For the RDS group, average CSA level (+/- S.E.) at 3 and 6 months was 190 +/- 12 and 180 +/- 9; avg. MMF dose, 1.7 +/- 0.1 g and 1.7 +/- 0.1 g. There was no significant difference in 6- and 12-month actuarial patient survival, graft survival and rejection-free graft survival between recipients on the RDS protocol vs. historical controls. For RDS recipients, actuarial 6- and 12-month rejection-free graft survival was 87%. Of the 51 RDS recipients, five (10%) have had AR (at 20 days, 1 month, 3 months, 3 months, and 3.5 months post-transplant). After treatment, all five were maintained on 5 mg P; there have been no second AR episodes. Two additional recipients were started on 5 mg P due to low white blood count (WBC) and low/no MMF. Of the 51 grafts, one has failed (death with function). Average serum Cr level (+/- S.E.) at 3 and 6 months for RDS recipients was 1.7 +/- 0.5 (NS vs. historical controls).

CONCLUSION

For low-risk LD recipients, a kidney transplant with an RDS protocol does not increase risk of AR or graft loss. Future studies will need to be done to assess AR rates with an RDS protocol in cadaver transplant recipients and in recipients with delayed graft function.

Activation and expression of ERK, JNK, and p38 MAP-kinases in isolated islets of Langerhans: implications for cultured islet survival

Isolation and purification of islet cells exposes them to ischemic, osmotic and mechanical stresses. The objective of this study was to determine the roles of the MAP-kinases in islets immediately following isolation. During the first 48 h, activity of JNK1 and JNK2 declined markedly. Activity of p38 increased steadily with time in culture while extracellular signal regulated kinase (ERK) activity declined dramatically within 24 h post-isolation. High p38 activation relative to ERK activation immediately following isolation correlated with a decrease in islet survival after 36 h in culture. Absence and/or transiency of ERK signaling in conjunction with sustained activation of p38 pathway could be an important regulator of cell death in islets during and following their isolation by commonly employed procedures.

A review of the effects of stannous fluoride on gingivitis

AIM

To review the literature on the effects of stannous fluoride on gingivitis.

MATERIAL AND METHODS

The Medline and cochrane central register of controlled trials were searched up to August 2005 to identify appropriate studies. The primary outcome measure was gingivitis.

RESULTS

Independent screening of titles and abstracts of 542 papers resulted in 36 publications (inter-reviewer ê score of 0.76), out of which 15 papers finally fulfilled the criteria of eligibility. For SnF(2)dentifrices, a statistically significant reduction in gingivitis was noted in comparison with control (weighted mean difference (WMD) of 0.15 (gingival index) and 0.21 (gingivitis severity index) (test for heterogeneity p<0.00001, I(2)=91.1% and p=0.03, I(2)=80.1%, respectively)). With regard to plaque reduction inconsistent results existed. On using the plaque index no differences were found, whereas meta-analysis of the Turesky index provided a WMD of 0.31 (p=0.01, test for heterogeneity p<0.0001, I(2)=91.7%). Because of insufficient data, a meta-analysis for SnF(2)mouth rinse and dentifrice/mouthrinse formulations was not performed.

CONCLUSIONS

The use of SnF(2) dentifrices results in gingivitis and plaque reduction when compared with a conventional dentifrice. The precise magnitude of this effect was difficult to assess because of a high level of heterogeneity in study outcomes.

Randomized controlled clinical trials on agents used for chemical plaque control

Taking into account the limitations of the daily self-performed oral hygiene the use of chemical agents that can be incorporated in dentifrice or mouth rinse formulations has been advocated. The present review deals with randomized controlled clinical trials of >or=6 months in duration, on the use of those agents and their effects on plaque and gingival inflammation.

The effect of a pulsed Nd:YAG laser in non-surgical periodontal therapy

BACKGROUND

Laser treatment may serve as an alternative or adjunctive treatment to conventional mechanical therapy in periodontics. The neodymium-doped:yttrium, aluminum, and garnet (Nd:YAG) laser has been used in periodontics. Systematic reviews aid in clinical decision-making. The aim of this study was to evaluate, in a systematic manner and after a comprehensive search of the literature, the (additional) therapeutic effects of using a pulsed Nd:YAG laser in the initial treatment of patients with periodontitis.

METHODS

The focused question for this systematic review was, "What is the efficacy of a pulsed Nd:YAG laser in the initial treatment of patients with periodontitis, either as monotherapy or as an adjunct to non-surgical periodontal treatment?" The efficacy of this technique was compared to conventional therapy (ultrasonics and/or hand instrumentation) in removing plaque, as well as in improving clinical parameters, such as periodontal inflammation and probing depth. Articles published before May 2008 in the databases of MEDLINE/PubMed and the Cochrane Central Register of Controlled Trials were searched to identify appropriate studies. Clinical parameters of periodontal inflammation, namely, plaque, bleeding, gingivitis, probing depth, clinical attachment level, and gingival recession, were selected as outcome variables.

RESULTS

Independent screening of the titles and abstracts of 285 PubMed and 38 Cochrane articles resulted in eight publications that met the eligibility criteria. Means +/- SDs were collected by data extraction; only descriptive analysis was possible.

CONCLUSIONS

The majority of the studies analyzed showed no beneficial effect of a pulsed Nd:YAG laser compared to conventional therapy (ultrasonics and/or hand instrumentation) in the initial treatment of patients with periodontitis. The pulsed Nd:YAG laser was assessed as monotherapy and as an adjunct to non-surgical periodontal treatment; efficacy was determined by the extent of plaque removal and the reduction of periodontal inflammation. This literature review suggests that there is no evidence to support the superiority of the Nd:YAG laser over traditional modalities of periodontal therapy.

Modulation of JNK and p38 stress activated protein kinases in isolated islets of Langerhans: insulin as an autocrine survival signal

OBJECTIVE

The objective of this study was to determine the effects of islet isolation and cytokine exposure on e-JUN NH2 terminal kinase (JNK) and p38 activation and whether insulin or the p38 inhibitor PD169316 could modify the response.

SUMMARY BACKGROUND DATA

Islet transplantation exposes the cells of the graft to a variety of stressful stimuli that could promote beta-cell death and lead to graft failure.

METHODS

Islets from canine (n = 12) and cadaveric human (n = 6) pancreata were isolated and purified. Islets were cultured in CMRL 1066 with and without 100 ng/ml insulin. The response to cytokine stimulation with tumor necrosis factor (TNF)alpha and IL-1 beta and the p38 inhibitor PD169316 was also observed. Islet lysates were analyzed by Western blotting for total and phosphorylated JNK and p38 content. Apoptosis was assessed by TdT-mediated dUTP nick end labeling (TUNEL) assay and by a specific cell death enzyme-linked immunosorbant assay (ELISA).

RESULTS

In unstimulated islets, JNK activity was highest immediately following isolation, declining over 3 days to a low baseline level. The activity of p38 was lowest immediately after isolation, increasing progressively with time. The addition of insulin resulted in a more rapid decline in JNK activity, as opposed to p38, which showed no decrease in phosphorylation in response to insulin. In the cytokine stimulation studies, IL-1 beta stimulated p38 activation in a dose dependent manner, while JNK was relatively unaffected. PD169316 (100 microg/ml) was able to inhibit p38 activation in response to the isolation procedure as well as cytokine stimulation. Apoptotic activity was highest 24 hours after isolation, and was significantly reduced when islets were maintained in insulin-supplemented medium.

CONCLUSIONS

Inhibition of the stress-activated protein kinase (SAPK) pathways may be important for the maintenance of islet cell survival following islet isolation for transplantation. This study supports an autocrine role of insulin in this process.

The Additional Effect of a Dentifrice on the Instant Efficacy of Toothbrushing: A Crossover Study

BACKGROUND

Inconclusive evidence exists in the literature with regard to the additional (beneficial) mechanical effect of a dentifrice on plaque removal. A previous split-mouth study found that a dentifrice did not contribute to plaque removal. Because of limitations of the split-mouth model, a crossover design was used to evaluate whether a commercially available dentifrice had an additional effect on mechanical plaque removal during manual toothbrushing.

METHODS

Thirty-six subjects were given a manual toothbrush and a standard dentifrice. After a 48-hour plaque accumulation, subjects brushed under supervision with or without a dentifrice (total time of 2 minutes) in a 2 x 2 crossover design.

RESULTS

Plaque reductions were 50% with and 56% without the use of dentifrice. This 6% difference was statistically significant (P = 0.034). Explorative analysis showed that brushing without a dentifrice was more effective in removing plaque on the approximal surfaces.

CONCLUSIONS

The use of a dentifrice did not contribute to mechanical plaque removal during manual toothbrushing. It seemed that the mechanical action provided by the toothbrush was the main factor in the plaque-removing process.

Autocrine insulin action activates Akt and increases survival of isolated human islets

AIMS/HYPOTHESIS

The phosphatidylinositol 3-kinase (PI3K)/Akt pathway plays a critical role in promoting the survival of pancreatic beta cells. Akt becomes activated in isolated human islets following overnight culture despite significant levels of cell death. The aim of the current study was to identify the cause of the observed increase in Akt phosphorylation in isolated islets. We hypothesised that a factor secreted by the islets in culture was acting in an autocrine manner to activate Akt.

METHODS

In order to identify the stimulus of the PI3K/Akt pathway in culture, we examined the effects of different culture conditions on Akt phosphorylation and islet survival during the immediate post-isolation period.

RESULTS

We demonstrated that islet-conditioned medium induced Akt phosphorylation in freshly isolated human islets, whereas frequent medium replacement decreased Akt phosphorylation. Following overnight culture, islet-conditioned medium contained significantly elevated levels of insulin, indicating that insulin may be responsible for the observed increase in Akt phosphorylation. Indeed, treatment with an anti-insulin antibody or with inhibitors of insulin receptor/IGF receptor 1 kinase activity suppressed Akt phosphorylation, leading to decreased islet survival. In addition, dispersion of islets into single cells also suppressed Akt phosphorylation and induced islet cell death, indicating that islet integrity is also required for maximal Akt phosphorylation.

CONCLUSIONS/INTERPRETATION

Our findings demonstrate that insulin acts in an autocrine manner to activate Akt and mediate the survival of isolated human islets. These findings provide new information on how culturing islets prior to transplantation may be beneficial to their survival by allowing for autocrine activation of the pro-survival Akt pathway.

Chlorine dioxide and chlorhexidine mouthrinses compared in a 3-day plaque accumulation model

BACKGROUND

The aim of this study was to investigate the inhibiting effect of a chlorine dioxide mouthrinse as opposed to a mouthrinse containing chlorhexidine (0.20%) during 3 days of plaque accumulation.

METHODS

At baseline, all participants (N=77) received a professional prophylaxis and were randomly assigned to the test (chlorine dioxide) or (positive) control (chlorhexidine) group. On the following 3 days, both groups rinsed twice daily for 1 minute with 10 ml test or control solution. At the end of the experimental period, plaque was assessed, and the panelists filled out a questionnaire.

RESULTS

Chlorhexidine inhibited plaque growth significantly more than the mouthrinse containing chlorine dioxide (plaque index=1.39 versus 1.96, respectively; P<0.001). The results of the questionnaire showed that the panelists found chlorhexidine easier to use and more effective. However, they preferred the taste of the chlorine dioxide mouthrinse and experienced less taste alterations.

CONCLUSION

Chlorine dioxide mouthrinse seems to be a less potent plaque inhibitor than chlorhexidine.

Signals for death and differentiation: a two-step mechanism for in vitro transformation of adult islets of Langerhans to duct epithelial structures

Phenotypic change of adult pancreatic islets has been implicated in the development of certain pancreatic cancers and in islet transplant failure. The aim of this study was to characterize intracellular events that mediate changes in adult islet phenotype. Using an in vitro islet-to-duct transformation model, canine islets were induced to undergo phenotypic transformation to duct-like epithelial structures through a two-stage process. Stage one was characterized by widespread islet cell apoptosis associated with the formation of cavitary spaces within the islets. During this stage, c-Jun N-terminal regulated kinase (JNK) and caspase-3 activities were elevated, while extracellular signal-regulated kinase (ERK) and Akt activities were decreased. The second stage of the process was characterized by an inversion in the balance in activity between these signal transduction pathways and by a concomitant decrease in apoptosis. The transformed islets were no longer immunoreactive for islet cell hormones, but expressed the duct epithelial cell marker CK-AE1/AE3. In contrast to islet cells, these duct epithelial cells were highly proliferative. To clarify the role of the identified changes in signal transduction events, we performed additional studies using pharmacological inhibitors of enzyme activity and demonstrated that inhibition of JNK and caspase-3 activity prevented cystic transformation. Our results indicate that the balance in signaling activity between ERK/Akt and JNK/caspase-3 appears to be an important regulator of islet cell death and differentiation.

The effect of a dentifrice and mouth rinse combination containing amine fluoride/stannous fluoride on plaque and gingivitis: a 6-month field study

AIM

To examine the effect of amine fluoride/stannous fluoride (AmF/SnF(2))-containing dentifrice and mouth rinse on plaque formation and gingivitis as compared with habitual oral hygiene procedures with a regular sodium fluoride (NaF) dentifrice.

MATERIAL AND METHODS

In total, 22 general practices participated in this research project. The participants (N=281) were randomly assigned into two groups: the test group received an AmF/SnF(2) dentifrice-mouth rinse combination and the control group received a NaF-containing dentifrice. The patients were requested to brush twice daily for approximately 2 min. The subjects of the test group had to rinse additionally in the evening for 30 s with 10 ml of the mouth rinse.

RESULTS

Both groups started with comparable scores of plaque, bleeding and staining. At 6 months, the plaque scores were 0.95 for the AmF/SnF(2) group and 0.99 for the NaF group (decrease of 16% and 10%, respectively). Bleeding scores, although significantly different from baseline, did not show differences between the two regimes. At the end of the experimental period, the overall staining was more pronounced in the AmF/SnF(2) group (41%) than the NaF group (26%). Both plaque reduction and increase in staining seemed to be correlated to the amount of mouth rinse used in the test group.

CONCLUSION

In instruction-resistant patients recruited from dental practices, the combined use of AmF/SnF(2) did not decrease gingivitis at a significant level in comparison with the regular regime of two times daily brushing with an NaF-containing dentifrice. However, the above-mentioned combination resulted in greater plaque reduction than that observed with the use of the conventional dentifrice. When used according to the manufacturer's instructions, this effect on plaque scores was more pronounced.

Successful salvage of kidney allografts threatened by ureteral stricture using pyelovesical bypass

Ureteral stricture is the most common urologic complication after renal transplantation. When endourologic management fails, open ureteral reconstruction remains the standard treatment. The complexity of some of these procedures makes it necessary to explore other means of repair. This study evaluated the intermediate-term outcome of subcutaneous pyelovesical bypass graft (SPBG) on renal transplant recipients. We reviewed 8 patients (6 male and 2 female; mean age 52 years) with refractory ureteral strictures postrenal transplantation, who received SPBG as salvage therapy. All patients failed endourologic management and half failed open management of their strictures. After a mean follow-up of 19.4 months, 7 out of 8 renal grafts have good function with mean GFR of 58.5 mL/min/1.73 m(2), without evidence of obstruction or infection. One patient lost his graft due to persistent infection of the SPBG and one patient developed a recurrent urinary tract infection managed with long-term antibiotics. SPBG offers a last resort in the treatment of ureteral stricture after renal transplantation refractory to conventional therapy.

Additional Effect of Dentifrices on the Instant Efficacy of Toothbrushing

BACKGROUND

Inconclusive evidence exists in the literature with regard to the additional effect of the use of dentifrice on plaque removal. The present study was undertaken to test whether the use of dentifrice during toothbrushing contributes to the instant cleaning efficacy of the brushing procedure.

METHODS

Three groups of patients, 40 subjects each, were randomly assigned to one of three dentifrices that differed with respect to the relative dentin abrasivity (RDA) value. After a 48-hour plaque accumulation, subjects brushed under supervision in a split-mouth order with or without the use of dentifrice (total time=2 minutes).

RESULTS

Plaque reductions varied between 51% and 58% for the three dentifrices. The overall analysis showed a mean difference of 3% in plaque reduction in favor of brushing without dentifrice (P=0.017). The type of dentifrice did not influence this observed difference (P=0.506). Also, the order of the brushing procedure (starting the brushing procedure with or without dentifrice) had no interaction with the effect of dentifrice on the brushing (P=0.187).

CONCLUSIONS

The use of dentifrice does not contribute to the instant mechanical plaque removal during manual toothbrushing. A higher dentifrice abrasivity does not seem to contribute to increased plaque removal with a manual toothbrush. It appears that the mechanical action provided by the use of a toothbrush is the main factor in the plaque-removing process.

Do biliary endoprostheses decrease biliary complications after liver transplantation?

AIM

Most technical complications after orthotopic liver transplantation (OLT) are related to the biliary tree. This report reviews the role of routine intraoperative placement of stents to reduce biliary complications.

METHODS

We retrospectively analyzed 396 consecutive OLTs. We reviewed rates of biliary complications after hepaticojejunostomy (HJA) as well as following choledochocholedochostomy (CCA) groups: "experimental" group (routine intraoperative biliary stenting, last 10 months), "recent" control group (nonstented, previous 10 months), "historical" control group (prior to that period of time).

RESULTS

All groups were matched for donor/recipient characteristics and for graft cold/warm ischemia time. The overall prevalence of biliary complications was 30.7% after CCA versus 35% after HJA. In the experimental group 21 patients had a 4.8% biliary complication rate compared to the recent control and historical groups, where biliary complication rates were 30% and 32.6%, respectively (P <.05).

CONCLUSIONS

The intraoperative use of biliary stents is feasible and appears to decrease the rate of biliary complications. These results support the need for a prospective randomized trial.

Amine fluoride/stannous fluoride and incidence of root caries in periodontal maintenance patients. A 2-year evaluation

AIM

The purpose of the present study was to evaluate in a group of periodontal maintenance patients, the effect of using a dentifrice and mouthrinse containing amine fluoride (AmF) and stannous fluoride (SnF2) as compared with a dentifrice and mouthrinse both containing sodium fluoride (NaF) with regard to their root caries experience.

MATERIAL

In total, 80 patients who had been treated for moderate-to-severe periodontitis agreed to participate in this study. Subjects received supportive periodontal therapy at regular intervals of 3-4 months for at least a period of 1 year. The patients were randomly divided into two groups: (1) the test group used an AmF/SnF2 dentifrice and mouthrinse and (2) the control group used an NaF-containing dentifrice and mouthrinse. Root caries was recorded at four sites per tooth at baseline and 24 months.

RESULTS

An increase in number of the exposed root surfaces was noted for both groups during the experimental period (p<0.05). The mean number of active caries lesions at baseline was 2.1 and 1.8 for the test group and control group, respectively. At 24 months, the corresponding values were 1.8 for the test and 2.2 for the control group. An increase of the mean number of restored surfaces was noted for the AmF/SnF2 group (from 7.3 to 13.4) and the control group (from 7.9 to 14.7) during the course of the study. This increase was found to be statistically significant for both groups in comparison with the baseline values (p< or =0.01). No statistically significant differences were noted between groups. Further analysis of the restored surfaces revealed that the major increase in number of the restorations was associated with restorations involving three to four root surfaces in the same tooth. Molars and premolars were the teeth receiving most new restorations.

CONCLUSION

The present study did not detect a difference in terms of root caries development between the two groups. Root caries development is a common finding associated with surfaces developing recession in patients once treated for periodontal problems.