Treatment of peri-implantitis: clinical outcome of chloramine as an adjunctive to non-surgical therapy, a randomized clinical trial.

PURPOSE: To evaluate the adjunctive clinical effects of a chloramine to non-surgical treatment of peri-implantitis. MATERIAL AND METHODS: Eighteen individuals diagnosed with peri-implantitis (clinical signs of inflammation and progressive bone loss) on at least two implants were included. Clinical variables; plaque accumulation (Pl), probing depth (PD), clinical attachment level (CAL) and bleeding on probing (BoP), were recorded at baseline and at 3-month follow-up. Primary clinical efficacy variable was the change in the number of sites with BoP. The implants were randomized into two different treatment groups: test and control. Both implants received supra- and submucosal debridement by ultrasonic instrumentation supplemented with hand instruments. The implants assigned to the test group first received local applications of a chloramine gel (Perisolv™ ; RLS Global AB, Gothenburg, Sweden) followed by mechanical instrumentation. The oral hygiene was checked at 6 weeks. RESULTS: After 3 months, implants of both groups showed statistically significant reduction (P < 0.001) in the number of BoP-positive sites compared with baseline. The reduction of BoP-positive sites in the test group changed from 0.97 (SD ± 0.12) to 0.38 (SD ± 0.46), and in the control group from 0.97 (SD ± 0.12) to 0.31 (SD ± 0.42). Between-group comparisons revealed no statistically significant differences at baseline and after 3 months, for BoP or any of the other variables. CONCLUSION: In the present randomized clinical trial of peri-implantitis therapy; non-surgical mechanical debridement with adjunctive use of a chloramine is equally effective in the reduction of mucosal inflammation as conventional non-surgical mechanical debridement up to 3 months.

Microbial community dynamics of an urban drinking water distribution system subjected to phases of chloramination and chlorination treatments.

Water utilities in parts of the U.S. control microbial regrowth in drinking water distribution systems (DWDS) by alternating postdisinfection methods between chlorination and chloramination. To examine how this strategy influences drinking water microbial communities, an urban DWDS (population ≅ 40,000) with groundwater as the source water was studied for approximately 2 years. Water samples were collected at five locations in the network at different seasons and analyzed for their chemical and physical characteristics and for their microbial community composition and structure by examining the 16S rRNA gene via terminal restriction fragment length polymorphism and DNA pyrosequencing technology. Nonmetric multidimension scaling and canonical correspondence analysis of microbial community profiles could explain >57% of the variation. Clustering of samples based on disinfection types (free chlorine versus combined chlorine) and sampling time was observed to correlate to the shifts in microbial communities. Sampling location and water age (<21.2 h) had no apparent effects on the microbial compositions of samples from most time points. Microbial community analysis revealed that among major core populations, Cyanobacteria, Methylobacteriaceae, Sphingomonadaceae, and Xanthomonadaceae were more abundant in chlorinated water, and Methylophilaceae, Methylococcaceae, and Pseudomonadaceae were more abundant in chloraminated water. No correlation was observed with minor populations that were detected frequently (<0.1% of total pyrosequences), which were likely present in source water and survived through the treatment process. Transient microbial populations including Flavobacteriaceae and Clostridiaceae were also observed. Overall, reversible shifts in microbial communities were especially pronounced with chloramination, suggesting stronger selection of microbial populations from chloramines than chlorine.

Inactivation of Nitrosomonas europaea and pathogenic Escherichia coli by chlorine and monochloramine.

The purpose of this study was to measure the chlorine and monochloramine inactivation kinetics of Nitrosomonas europaea at 21 degrees C in the presence and absence of particles. The inactivation kinetics rates were compared with those obtained with Escherichia coli O157:H7. The results show that, in pure water, the use of free chlorine produced 4 log10 of N. europaea inactivation at a CT value of 0.8 mg.min l(-1), whereas monochloramine yielded 4 log10 of inactivation at CT values of approximately 9.9-16.4mg.min l(-1). With E. coli, chlorine produced approximately 4 1og10 of inactivation at a CT of 0.13 mg.min l(-1), whereas monochloramine resulted in 4 logo10 of inactivation at a CT of approximately 9.2 mg.min l(-1). These results suggest that N. europaea is more resistant to monochloramine and chlorine than E. coli. Corrosion debris, soil material and wastewater had no statistically significant (p < 0.05) impact on the inactivation of N. europaea by either chlorine or monochloramine. It seems likely that the CT values present in distribution systems would be sufficient to control suspended cells of these two organisms, especially under conditions of breakpoint chlorination, which could be used to control nitrification. Adequate disinfection should prevent the growth of these organisms in a distribution system.

[Mycobacterium ulcerans infection treated by Rifater, pyrazynamide, Myambutol, and surgery: a case report with a 6-year follow-up]. / Infection à Mycobacterium ulcerans traitée par Rifater, pyrazynamide, Myambutol associés à la chirurgie : à propos d'un cas avec un recul de six ans.

The author reports a case of pleuritis associated with a large homolateral Buruli thorax ulcer in a nine-year old female patient, in the Democratic Republic of Congo. Smears on Ziehl-Neelsen revealed acid-alcohol-resistant bacilli. The pathological histology confirmed a Mycobacterium ulcerans infection (Buruli ulcer). The treatment was surgical (excision-dressing-grafting) associated to antibiotic therapy (Rifater, Pyrazynamide, and Myambutol). After six years of follow up, no relapse was observed.

Metabolic effects of amoebic gill disease (AGD) and chloramine-T exposure in seawater-acclimated Atlantic salmon Salmo salar.

Our aim was to determine possible metabolic effects amoebic gill disease (AGD) on Atlantic salmon Salmo salar. Standard (R(S)) and routine (R(ROU)) metabolic rates were evaluated by continually measuring oxygen consumption in 2 independent tanks of fish (18.69 +/- 1.01 kg m(-3), mean +/- SE). Active metabolic rate (R(ACT)) and metabolic scope (R(ACT) - R(S)) were assessed using a chasing protocol and determined at 3 time periods: (1) pre-infection, (2) 3 d post-infection, and (3) 2 d post-treatment. On Day 3 of the study, the fish were infected with amoebae isolated from the gills of AGD-affected salmon (2300 cells l(-1)). No significant elevations in R(ACT) or metabolic scope were detected 3 d post-infection and 2 d post-treatment; however, significant elevations in R(S) and R(ROU) were detected 3 d post-infection and 2 d post-treatment. Assessment of R(ROU) data, especially for the light period, also indicated a rise in oxygen consumption rate over the course of the experiment. Treatment of AGD-affected Atlantic salmon with chloramine-T (CL-T) appeared to briefly mitigate the rise in R(S), as there was a 30% drop (though non-significant) in R(S) following treatment. Despite this, R(S) continued the upward trend 1 d following treatment. These results suggest that over the course of AGD development, R(S) in Atlantic salmon increases. Therefore, considering the physical conditions which constrain R(ACT), we expect that metabolic scope would become compromised in fish more heavily affected with AGD. Treatment with CL-T shows promise for mitigating the respiratory effects of AGD and potentially minimising the loss of metabolic scope.

Monochloramine induces acute and protracted colitis in the rat: response to pharmacological treatment.

Monochloramine is a powerful oxidative molecule that is produced in inflammatory sites. We investigated the effect of intrarectally administered monochloramine (3.2 mg) in the rat. A single enema induced after 24 h an intense inflammatory reaction characterized by mucosal necrosis, submucosal edema, hemorrhage and colonic thickening, as well as induction of nitric oxide synthase and tumor necrosis factor and an increase in the interferon gamma/interleukin 4 ratio. The inflammatory response peaked 3-5 days after monochloramine administration and then followed a extended recovery phase. At 1 week there was substantial but incomplete mucosal repair, submucosal edema, neutrophil/macrophage infiltration and increased myeloperoxydase and alkaline phosphatase activities. Oxidative stress, as determined by malonyldialdehyde levels, was prominent only in the acute phase (3-5 days). Monochloramine colitis was amenable to pharmacological treatment with sulphasalazine or prednisolone, suggesting that it may be used as an experimental model of inflammatory bowel disease. In conclusion, monochloramine induces acute and protracted colonic inflammation in the rat. Locally produced monochloramine might contribute to the perpetuation of inflammatory bowel disease.

Preparation of Hollow N-Chloramine-Functionalized Hemispherical Silica Particles with Enhanced Efficacy against Bacteria in the Presence of Organic Load: Synthesis, Characterization, and Antibacterial Activity.

The fabrication of highly effective antimicrobial materials is an important strategy for coping with the growing concern of bacterial resistance. In this study, N-chloramine-functionalized hollow hemispherical structures were designed and prepared to examine possible enhancement of antimicrobial performance. Antimicrobial testing was carried out on Gram-negative (Escherichia coli) and Gram-positive (Baccilus Cereus) bacteria in the presence and absence of biological medium. The efficacy of the hollow hemispherical particles functionalized with various N-chloramines in killing bacteria was compared among themselves with that of small organic molecules and spherical particles to investigate the effect of the surface charge, chemical structure, and shape of the particles. Results demonstrated that quaternary ammonium salt or amine functions in the chemical structure enhanced the antimicrobial activity of the particles and made the particles more effective than the small molecules in the presence of biological medium. The importance of particle shape in the killing tests was also confirmed.

Effects of drinking water monochloramine on lipid and thyroid metabolism in healthy men.

The purpose of this study was to determine whether a 4-week consumption of 1.5L per day of drinking water containing monochloramine at a concentration of 2 ppm (ppm = mg/L) or 15 ppm under controlled conditions would alter parameters of lipid or thyroid metabolism in healthy men. Forty-eight men completed an 8-week protocol during which diet (600 mg cholesterol per day, 40% calories as fat) and other factors known to affect lipid metabolism were controlled. During the first 4 weeks of the protocol, all subjects consumed distilled water. During the second 4 weeks, one-third of the subjects were assigned randomly to drink 1.5 L per day of water containing 2 ppm of monochloramine, to drink 1.5 L per day of water containing 15 ppm monochloramine, or to continue drinking distilled water. Four blood samples were collected from each subject at the end of each 4-week study period. Subjects drinking monochloramine at a concentration of 2 ppm showed no significant changes in total cholesterol, triglycerides, HDL cholesterol, LDL cholesterol, apolipoproteins A1, A2, or B when compared to the distilled water group. Parameters of thyroid function also were unchanged by exposure to monochloramine at this concentration. However, subjects drinking monochloramine at a concentration of 15 ppm experienced an increase in the level of apolipoprotein B. Other parameters of lipid and thyroid metabolism did not change. We conclude that consumption of drinking water containing 2 ppm of monochloramine does not alter parameters of lipid and thyroid metabolism in healthy men. Consumption of water containing 15 ppm monochloramine may be associated with increased levels of plasma apolipoprotein B.

Superficial wound dehiscence after median sternotomy: surgical treatment versus secondary wound healing.

BACKGROUND: Superficial wound dehiscence after midline sternotomy is considered a minor complication in cardiac surgery, although it is quite frequent and requires prolonged medical treatment. It can be managed conventionally by topical treatment, with delayed secondary healing, or by surgical treatment and primary skin closure. We report the outcome of 96 patients who underwent conventional treatment, compared with a second group of 42 patients who underwent surgical treatment and direct closure. METHODS: From October 1999 to December 2002, 2400 consecutive patients underwent median sternotomy: 207 patients had sternal wound complications: 3 patients (0.125%) had mediastinitis, 66 patients (2.75%) had aseptic deep sternal wound dehiscence, and 138 patients (5.75%) had superficial wound dehiscence. The latter are the object of the present study; patients entered a protocol of skin wound care on an outpatient basis. The first 96 consecutive patients (group 1) required medications three times a week until complete healing. The last 42 patients (group 2) were treated by extensive surgical debridement of skin and subcutaneous tissue, direct closure of the superficial layers, and suture removal after 15 days. RESULTS: The two groups were comparable as to age, sex, and preoperative risk factors. The incidence of contaminated wounds was similar in the two groups (32 of 96 in group 1 and 11 of 42 in group 2; p = NS). The length of treatment was 29.7 days (range 2 to 144 days) for group 1 and 12.2 days (range 2 to 37 days) for group 2 (p < 0.0001). The mean number of medical treatments was 9.4 per patient in group 1 and 3.7 per patient in group 2 (p < 0.0001). CONCLUSIONS: Surgical debridement and primary closure of superficial surgical wound dehiscence after median sternotomy is a safe and valid treatment. Wound infection is not a contraindication to surgical treatment. Primary closure may contribute to reduce the risk for later infection. It also definitely contributes to decreasing healing time and strongly lessens patients' discomfort, diminishing hospital costs and hospital staff workload.

Histamine chloramines have a persistent stimulating effect on histamine H2 receptors and gastric acid secretion.

Histamine plays an important role in the control of gastric acid secretion. Recently, chlorinated derivatives of histamine have been identified as having multiple effects on the intestinal tract. The aim of this study was to investigate the role of histamine chloramines on gastric acid secretion. We compared the effects of histamine and histamine chloramines on the histamine H2 receptors in vitro using guinea pigs and on gastric acid secretion in rats. With respect to the effects on histamine H2 receptors, histamine monochloramine showed agonist effects similar to those seen with histamine, but the agonist effects of histamine dichloramine were about half those of histamine. Unlike histamine effects, the histamine H2 receptor agonist effects of histamine monochloramine and histamine dichloramine did not disappear after repeated washout. With respect to the stimulation of gastric acid secretion in vivo, histamine monochloramine was similar to histamine, while the effect of histamine dichloramine was 42.2-52.7% of that of histamine. The recovery time to the basal secretory level after completion of stimulation by histamine chloramines was significantly prolonged compared with histamine. These results suggest that histamine chloramines, which bind strongly with histamine H2 receptors, may delay the termination of gastric acid secretion and increase the burden on the gastric and duodenal mucosa.

Modulation by chloramine-T of 4-aminopyridine-sensitive transient outward current in rabbit atrial cells.

The effects of an oxidizing agent, chloramine-T, on the 4-aminopyridine-sensitive transient outward current (ITO) were investigated in rabbit atrial myocytes by using patch-clamp techniques. Extracellular application of chloramine-T at 20 microM irreversibly slowed the time course of inactivation of the whole-cell ITO, and increased the peak by 19.3% (n = 19) at +40 mV. At 100 microM, chloramine-T decreased the peak by 22.5% (n = 9) of the control, and subsequently induced a glibenclamide-sensitive time-independent outward K+ current. Under superfusion with dithiothreitol (3 mM), chloramine-T (100 microM) produced no change in ITO. The chloramine-T-induced slowing of ITO inactivation was partially reversed by subsequent application of 3 mM dithiothreitol. In single-channel recordings with the cell-attached patch configuration, chloramine-T (20 microM) increased the open probability of the ITO channel from 0.15 to 0.46 at a potential 100 mV positive to the resting potential, and the mean open lifetime from 5.1 ms to 7.0 ms (n = 5). The unitary current amplitude was not affected. As a result, chloramine-T increased the ensemble current in amplitude and slowed its decay. These results indicated that: (1) inactivation of the native A-type channels of rabbit heart is susceptible to oxidation; and (2) oxidation of ITO channels may contribute to the genesis of arrhythmias.

Ulcerogenic and healing impairing actions of monochloramine in rat stomachs: effects of zinc L-carnosine, polaprezinc.

Effects of a novel zinc compound (polaprezinc), N-(3-aminopropionyl)-L-histidinato zinc, on the mucosal ulcerogenic and healing impairing responses induced by monochloramine (NH2Cl) were examined in rat stomach. Oral administration of NH2Cl (> 60 mM) produced severe hemorrhagic lesions in unanesthetized rat stomachs with a marked increase of thiobarbituric acid reactants (TBAR). Pretreatment of the animals with polaprezinc (3 approximately 30 mg/kg, p.o.) showed a dose-dependent inhibition against gastric ulcerogenic and TBAR responses induced by NH2Cl (120 mM). Likewise, mucosal exposure to NH4OH (60 mM) in urethane anesthetized stomachs made ischemic by bleeding from the carotid artery (1 ml per 100 g body w.t.) resulted in severe gastric lesions. This ulcerogenic response caused NH4OH plus ischemia was also attenuated by prior application of polaprezinc as well as taurine (25 mg/ml, 1 ml). On the other hand, the healing of gastric mucosal lesions induced by NH2Cl occurred more slowly than of ethanol-induced lesions, and the latter was significantly delayed by the repeated administration of NH2Cl. Polaprezinc (> 10 mg/kg, p.o.) given twice daily for 7 days not only accelerated the healing of NH2Cl-induced gastric lesions but also antagonized the delayed healing of ethanol-induced lesions in the presence of NH2Cl as well. Polaprezinc showed a scavenging action against NH2Cl in vitro. These results suggest that NH2Cl caused deleterious action on the healing of pre-existing acute lesions as well as irritating action to the mucosa in the rat stomach. Polaprezinc not only protects the stomach against injury caused by NH2Cl but also promotes healing of NH2Cl-induced gastric lesions as well as the delayed healing of ethanol-induced lesions caused by NH2Cl. Although the detailed mechanisms underlying these actions of polaprezinc remain unknown, they may be partly attributable to a scavenging action of this agent against NH2Cl.

The effects of chronic administration of chlorine dioxide, chlorite and chlorate to normal healthy adult male volunteers.

The physiological impact of chronic 12 week ingestion of chlorine dioxide and its byproducts, chlorite and chlorate, was compared to the effects of chlorine, chloramine and untreated water. The water disinfectant solutions were administered daily (500 ml, 5 ppm) to normal healthy adult male volunteers. An extensive battery of tests was used to evaluate the physiological impact of the ingested water disinfectants. Upon analysis of both quantitative and qualitative parameters it was concluded that the 12 week chronic administration of chlorine dioxide and its byproducts was accompanied by no clinically important physiological effects.

[Hydrogen peroxide, chloramine T and chlorhexidrine in the disinfection of acrylic resin]. / Woda utleniona, chloramina T i dwuglukonian chlorheksydyny jako srodki do odkazania tworzywa akrylowego.

The effectiveness of 3% h drogen peroxide, 5% chloramine T and 0,5% chlorhexidine gluconate solutions in disinfection of acrylic resine plates massively infected with oral flora was analysed. The acrylic resine plates used for investigations, were infected in vitro with mixed salivary flora characterized by small numbers of yeast-like fungi (1st group), or great number of these microorganisms (2nd group). Infected plates were exposed to solutions of analysed disinfectants during various time periods. After rinsing or inactivation of disinfectant residues, acrylic plates were put into bacteriological medium and incubated during 7 days period in 37 degrees C. The results of this study indicated the effectiveness of acrylic plates disinfection to be dependent on used disinfectant, time of exposition, and microorganisms present on the surface of acrylic resine. The solutions of disinfectants were less active in the cases of plates infected with material containing great numbers of yeast-like microorganisms. Among analysed disinfectants 0,5% solution of chlorhexidine was characterized by most effective and rapid activity, whereas 3% solution of hydrogen peroxide was found to be the least effective.

[Tactics in using aerosols for disinfection of therapeutic and prophylactic institutions]. / Taktika primeneniia aérozolei dlia tselei dezinfektsii pomeshchenii lechebno-profilakticheskikh uchrezhdenii.

Two Soviet sprayers (ABD-2600H and EOC-5) are recommended for the disinfection of the surfaces and indoor air in the curative and prophylactic facilities. A special impetus has been given to the use of chloramine aerosols that ensure higher efficacy of disinfection, reduce the aerosol consumption and the period of the presence of active chlorine in the air of the treated place.

Impact of chloramination on the development of laboratory-grown biofilms fed with filter-pretreated groundwater.

This study evaluated the continuous impact of monochloramine disinfection on laboratory-grown biofilms through the characterization of biofilm architecture and microbial community structure. Biofilm development and disinfection were achieved using CDC (Centers for Disease Control and Prevention) biofilm reactor systems with polyvinyl chloride (PVC) coupons as the substratum and sand filter-pretreated groundwater as the source of microbial seeding and growth nutrient. After 2 weeks of growth, the biofilms were subjected to chloramination for 8 more weeks at concentrations of 7.5±1.4 to 9.1±0.4 mg Cl2 L(-1). Control reactors received no disinfection during the development of biofilms. Confocal laser scanning microscopy and image analysis indicated that chloramination could lead to 81.4-83.5% and 86.3-95.6% reduction in biofilm biomass and thickness, respectively, but could not eliminate biofilm growth. 16S rRNA gene terminal restriction fragment length polymorphism analysis indicated that microbial community structures between chloraminated and non-chloraminated biofilms exhibited different successional trends. 16S rRNA gene pyrosequencing analysis further revealed that chloramination could select members of Actinobacteria and Acidobacteria as the dominant populations, whereas natural development leads to the selection of members of Nitrospira and Bacteroidetes as dominant biofilm populations. Overall, chloramination treatment could alter the growth of multi-species biofilms on the PVC surface, shape the biofilm architecture, and select a certain microbial community that can survive or proliferate under chloramination.

Inhalation exposure to chloramine T induces DNA damage and inflammation in lung of Sprague-Dawley rats.

Chloramine T has been widely used as a disinfectant in many areas such as kitchens, laboratories and hospitals. It has been also used as a biocide in air fresheners and deodorants which are consumer products; however, little is known about its toxic effects by inhalation route. This study was performed to identify the subacute inhalation toxicity of chloramine T under whole-body inhalation exposure conditions. Male and female groups of rats were exposed to chloramine T at concentrations of 0.2, 0.9 and 4.0 mg/m³ for 6 hr/day, 5 days/week during 4 weeks. After 28-day repeated inhalation of chloramine T, there were dose-dependently significant DNA damage in the rat tissues evaluated and inflammation was histopathologically noted around the terminal airways of the lung in both genders. As a result of the expression of three types of antioxidant enzymes (SOD-2, GPx-1, PRX-1) in rat's lung after exposure, there was no significant change of all antioxidant enzymes in the male and female rats. The results showed that no observed adverse effect level (NOAEL) was 0.2 mg/m³ in male rats and 0.9 mg/m³ in female rats under the present experimental condition.

Trial of experimental toothpastes regarding quality for cleaning dentures.

The aim of this study was to evaluate the efficacy of experimental toothpastes for removing denture biofilm by means of a randomized crossover trial. Thirty volunteers brushed their dentures using a brush and four pastes: (1) Corega refreshing mint (control), (2) 0.2% chloramine T, (3) 1.0% chloramine T, and (4) 0.01% fluorosurfactant. Each paste was used for 7 days, and participants were randomized to use them according to one of four sequences. Biofilm was disclosed (neutral red) after each period, photographed, and quantified by means of a software program. All experimental toothpastes were similar to the control in terms of posttreatment biofilm coverage.

New biocide with both N-chloramine and quaternary ammonium moieties exerts enhanced bactericidal activity.

Considering the rise of antibiotic resistance, the development of new antibacterial agents with improved biocidal functions is urgently required. In this study, ionic 5,5-dimethylhydantoin (DMH) analogues containing either a quaternary ammonium moiety (2)-4) or a phosphonate functional group (5),-6), were designed and synthesized to investigate the possible enhancing effect of quaternary ammonium moieties on the antibacterial performance of N-chloramines. These ionic DMH analogues were converted to their N-chloramine counterparts either in free form or after being covalently immobilized on a polymer surface via the "click" chemistry method. In the subsequent antimicrobial assessment against multi-drug-resistant Escherichia coli (MDR-E. coli) and methicillin-resistant Staphylococcus aureus (MRSA), chlorinated 2 and 3, the cyclic N-chloramines with a structural cation, exhibited distinctly enhanced biocidal functions in solution and after immobilization on surfaces.