CHRONIC EFFECTS OF CADMIUM CHLORIDE ON RAT EMBRYOGENESIS.

The purpose of this study was to analyze the effects of cadmium toxicity on rat embryogenesis when exposed to other heavy metal citrates. Despite the variety of scientific publications discussing the influence of cadmium on mammalian postnatal development, the effect of this metal on embryogenesis has not yet been sufficiently studied. In this experimental study, cadmium chloride was administered to experimental pregnant female Wistar rats at a daily dose of 1.0 mg/kg. Rats were allocated at random into groups receiving either cadmium chloride alone or additional zinc citrate, cerium citrate, or nanocomposite (based on iodine, sulfur, and selenium citrate). The control group received distilled water at an equivalent volume. In each group, operational intervention occurred at the 13th and 20th day of gestation to assess numbers of live fetuses, corpora lutea, pre-implantation losses, post-implantation losses, and total implantation losses. When cadmium chloride alone was administered, a pronounced embryotoxic effect was observed, manifested as a significant decrease in the number of live fetuses. Experimental groups which received cadmium chloride with zinc citrate, cerium citrate, or nanocomposite had an increased number of live fetuses and corpora lutea, as well as a decreased number of implantation losses, compared to the group which only received cadmium chloride. Each combination of cerium, zinc, and selenium nanocomposite citrates demonstrated a compensatory effect on all measures of embryogenesis impacted by cadmium embryotoxicity. Thus, administration of the citrates of cerium, zinc, and selenium nanocomposite reduces cadmium embryotoxicity and its accumulation in the body.

New Promises from an Old Friend: Iodine-Rich Compounds as Prospective Energetic Biocidal Agents.

For a very long time, frequent occurrences of biocrises have wreaked havoc on human beings, animals, and the environment. As a result, it is necessary to develop biocidal agents to destroy or neutralize active agents by releasing large amounts of strong biocides which are obtained upon detonation. Iodine is an efficient biocidal agent for bacteria, fungi, yeasts, viruses, spores, and protozoan parasites, and it is the sole element in the periodic table that can destroy microbes without contaminating the environment. Based on chemical biology, the mechanism of iodine as a bactericide may arise from oxidation and iodination reactions of cellular proteins and nucleic acids. However, because of the high vapor pressure causing elemental iodine to sublime readily at room temperature, it is inconvenient to use this material in its normal solid state directly as a biocidal agent under ambient conditions. Iodine-rich compounds where iodine is firmly bonded in molecules as a C-I or I-O moiety have been observed to be among the most promising energetic biocidal compounds. Gaseous products comprised of large amounts of iodine or iodine-containing components as strong biocides are released in the decomposition or explosion of iodine-rich compounds. Because of the detonation pressure, the iodine species are distributed over a large area greatly improving the efficacy of the system and requiring considerably less effort compared to traditional biocidal methods. The commercially available tetraiodomethane and tetraiodoethene, which possess superb iodine content also have the disadvantages of volatility, light sensitivity, and chemically reactivity, and therefore, are not suitable for use directly as biocidal agents. It is absolutely critical to synthesize new iodine-rich compounds with good thermal and chemical stabilities.In this Account, we describe our strategies for the syntheses of energetic iodine-rich compounds while maintaining the maximum iodine content with concomitant stability and routes for the synthesis of oxygen-containing iodine-rich compounds to improve the oxygen balance and achieve both high-energy and high-iodine content. In the other work, which involves cocrystals, iodine-containing polymers were also summarized. It is hoped that this Account will provide guidelines for the design and syntheses of new iodine-rich compounds and a route for the development of inexpensive, more efficient, and safer iodine-rich antibiological warfare agents of the future.

Modeling Oral Multispecies Biofilm Recovery After Antibacterial Treatment.

Recovery of multispecies oral biofilms is investigated following treatment by chlorhexidine gluconate (CHX), iodine-potassium iodide (IPI) and Sodium hypochlorite (NaOCl) both experimentally and theoretically. Experimentally, biofilms taken from two donors were exposed to the three antibacterial solutions (irrigants), respectively, for 10 minutes. We observe that (a) live bacterial cell ratios decline for a week after the exposure and the trend then reverses beyond the week; after fifteen weeks, live bacterial cell ratios in biofilms fully return to their pretreatment levels; (b) NaOCl is shown as the strongest antibacterial agent for the oral biofilms; (c) multispecies oral biofilms from different donors showed no difference in their susceptibility to all the bacterial solutions. Guided by the experiment, a mathematical model for biofilm dynamics is developed, accounting for multiple bacterial phenotypes, quorum sensing, and growth factor proteins, to describe the nonlinear time evolutionary behavior of the biofilms. The model captures time evolutionary dynamics of biofilms before and after antibacterial treatment very well. It reveals the important role played by quorum sensing molecules and growth factors in biofilm recovery and verifies that the source of biofilms has a minimal effect to their recovery. The model is also applied to describe the state of biofilms of various ages treated respectively by CHX, IPI and NaOCl, taken from different donors. Good agreement with experimental data predicted by the model is obtained as well, confirming its applicability to modeling biofilm dynamics in general.

Types of antiseptics, presentations and rules of use. / Tipos de antisépticos, presentaciones y normas de uso.

Antiseptics are chemical substances that when applied topically onto intact skin, mucous membranes or wounds partially or completely reduces the population of living microorganisms in those tissues. Different types of antiseptics are available - those most commonly used in clinical practice being alcohols, iodinated compounds and chlorhexidine. When using an antiseptic, consideration is required of its spectrum of antimicrobial activity, latency, residual effects, possible interferences of the presence of organic material with the activity of the antiseptic, its side effects, compatibility with other antiseptics, and cost. This article is part of a supplement entitled "Antisepsis in the critical patient", which is sponsored by Becton Dickinson.

Susceptibility of influenza viruses to hypothiocyanite and hypoiodite produced by lactoperoxidase in a cell-free system.

Lactoperoxidase (LPO) is an enzyme found in several exocrine secretions including the airway surface liquid producing antimicrobial substances from mainly halide and pseudohalide substrates. Although the innate immune function of LPO has been documented against several microbes, a detailed characterization of its mechanism of action against influenza viruses is still missing. Our aim was to study the antiviral effect and substrate specificity of LPO to inactivate influenza viruses using a cell-free experimental system. Inactivation of different influenza virus strains was measured in vitro system containing LPO, its substrates, thiocyanate (SCN-) or iodide (I-), and the hydrogen peroxide (H2O2)-producing system, glucose and glucose oxidase (GO). Physiologically relevant concentrations of the components of the LPO/H2O2/(SCN-/I-) antimicrobial system were exposed to twelve different strains of influenza A and B viruses in vitro and viral inactivation was assessed by determining plaque-forming units of non-inactivated viruses using Madin-Darby canine kidney cells (MDCK) cells. Our data show that LPO is capable of inactivating all influenza virus strains tested: H1N1, H1N2 and H3N2 influenza A viruses (IAV) and influenza B viruses (IBV) of both, Yamagata and Victoria lineages. The extent of viral inactivation, however, varied among the strains and was in part dependent on the LPO substrate. Inactivation of H1N1 and H1N2 viruses by LPO showed no substrate preference, whereas H3N2 influenza strains were inactivated significantly more efficiently when iodide, not thiocyanate, was the LPO substrate. Although LPO-mediated inactivation of the influenza B strains tested was strain-dependent, it showed slight preference towards thiocyanate as the substrate. The results presented here show that the LPO/H2O2/(SCN-/I-) cell-free, in vitro experimental system is a functional tool to study the specificity, efficiency and the molecular mechanism of action of influenza inactivation by LPO. These studies tested the hypothesis that influenza strains are all susceptible to the LPO-based antiviral system but exhibit differences in their substrate specificities. We propose that a LPO-based antiviral system is an important contributor to anti-influenza virus defense of the airways.

Effects and Effectiveness of Cavity Disinfectants in Operative Dentistry: A Literature Review.

The degree of success in the elimination of bacteria during cavity preparation and prior to the insertion of a restoration may increase the longevity of the restoration and therefore the success of the restorative procedure. The complete eradication of bacteria in a caries-affected tooth, during cavity preparation, is considered a difficult clinical task. In addition to weakening the tooth structure, attempts to excavate extensive carious tissue completely, by only mechanical procedures, may affect the vitality of the pulp. Therefore, disinfection of the cavity preparation after caries excavation can aid in the elimination of bacterial remnants that can be responsible for recurrent caries, postoperative sensitivity, and failure of the restoration. However, the effects of disinfectants on the restorative treatment have been a major concern for dental clinicians and researchers. This review aims to explore existing literature and provide information about different materials and techniques that have been used for disinfecting cavity preparations and their effects and effectiveness in operative dentistry and, therefore, helps dental practitioners with clinical decision to use cavity disinfectants during restorative procedures. Antimicrobial effectiveness and effects on the pulp and dental restorations, in addition to possible side effects, were all reviewed in this paper.

Automated carbon dioxide digital angiography for lower-limb arterial disease evaluation: safety assessment and comparison with standard iodinated contrast media angiography.

INTRODUCTION: Carbon dioxide (CO2) has been validated as a contrast agent in a large series of studies. A particular advantages of CO2 over iodinated contrast medium (ICM) is the absence of nephrotoxicity and allergic reactions. One of the limitations of CO2 angiography is the difficulty of CO2 manual injection due to its compressibility. The manual gas injection does not permit optimal control of the gas output. Development of an automated CO2 injector has overcome these problems. AIM: This study compares the feasibility, safety, and diagnostic accuracy of automated CO2 digital subtraction angiography (DSA) in comparison with ICM-DSA in the evaluation of critical limb ischemic (CLI) patients. METHODS: We performed DSA with both CO2 and ICM on 40 consecutive CLI patients and directly compared the two techniques. Sixteen females and 24 males participated in the study (mean age, 71.7 years). We assessed the diagnostic accuracy of CO2 in identifying arterial stenosis in the lower limb, with ICM-DSA used as the gold standard. RESULTS: The overall diagnostic accuracy of CO2-DSA was 96.9% (sensitivity, 99.0%; specificity, 96.1%; positive predictive value, 91.1%; negative predictive value, 99.6%). Tolerable minor symptoms occurred in 3 patients. No allergic reactions or significant decline in renal function were observed in patients receiving the CO2 injection. CONCLUSION: Carbon dioxide DSA is a valuable and safe alternative to traditional ICM-DSA for evaluating CLI patients. This modality should be considered as the standard choice for CLI patients undergoing angiographic evaluation who are known to have renal insufficiency or contrast allergy.

A pre-clinical evaluation of silver, iodine and Manuka honey based dressings in a model of traumatic extremity wounds contaminated with Staphylococcus aureus.

Prevention of extremity war wound infection remains a clinical challenge. Staphylococcus aureus is the most common pathogen in delayed infection. We hypothesised that choice of wound dressings may affect bacterial burden over 7 days reflecting the current practice of delayed primary closure of wounds within this timeframe. A randomised controlled trial of 3 commercially available dressings (Inadine(®) (Johnson & Johnson, NJ, USA), Acticoat(®) (Smith & Nephew, Hull, UK), Activon Tulle (Advancis Medical, Nottingham, UK)) was conducted in a rabbit model of contaminated forelimb muscle injury. A positive control group treated with antibiotics was included. Groups were compared to a saline soaked gauze control. The primary outcome was a statistically significant reduction (p < 0.05) in tissue S. aureus at 7 days post-injury. Secondary outcome measurements included bacteraemias, observational data, whole blood determination, ELISA for plasma biomarkers, PCR array analysis of wound healing gene expression and muscle/lymph node histopathology. Antibiotic, Inadine and Acticoat groups had statistically significant lower bacterial counts (mean 7.13 [95% CI 0.00-96.31]×10(2); 1.66 [0.94-2.58]×10(5); 8.86 [0.00-53.35]×10(4)cfu/g, respectively) and Activon Tulle group had significantly higher counts (2.82 [0.98-5.61]×10(6)cfu/g) than saline soaked gauze control (7.58 [1.65-17.83]×10(5)cfu/g). There were no bacteraemias or significant differences in observational data or whole blood determination. There were no significant differences in muscle/loss or pathology and lymph node cross-sectional area or morphology. There were some significant differences between treatment groups in the plasma cytokines IL-4, TNFα and MCP-1 in comparison to the control. PCR array data demonstrated more general changes in gene expression in the muscle tissue from the Activon Tulle group than the Inadine or Acticoat dressings with a limited number of genes showing significantly altered expression compared to control. This study has demonstrated that both Acticoat(®) and Inadine(®) dressings can reduce the bacteria burden in a heavily contaminated soft tissue wound and so they may offer utility in the clinical setting particularly where surgical treatment is delayed.

Involvement of α7 nAChR subtype in rat oxaliplatin-induced neuropathy: effects of selective activation.

Oxaliplatin, unlike other platinum anticancer agents, has only mild toxic effects on the hematopoietic, urinary and gastrointestinal systems. Its dose-limiting side effect is neurotoxicity that may evolve to a neuropathic syndrome which is difficult to treat. In this study we treated rats with oxaliplatin (2.4 mg/kg/day intraperitoneally, for 3 weeks), and observed that expression levels of the α7 nicotinic acetylcholine receptor (nAChR) subunit were dramatically decreased both in the peripheral and central nervous system. The repeated administration (30 mg/kg/day per os, for 3 weeks) of (R)-ICH3, the most active enantiomer of a novel α7 nAChR agonist, and of PNU-282987 prevented the receptor down-regulation. On the other hand, both agonists per se up-regulated the α7 nAChR subunit compared to control. (R)-ICH3 and PNU-282987 significantly reduced oxaliplatin-dependent alterations of the pain threshold when noxious or non-noxious stimuli were used. Further ex vivo analysis highlighted their neuroprotective effects in dorsal root ganglia and peripheral nerves. The two agonists did not prevent the increase in microglia cell number induced by oxaliplatin in the central nervous system. Astrocyte density was enhanced by the agonist treatment in the spinal cord, thalamus and somatosensory area 1 as opposed to the effects of oxaliplatin treatment. (R)-ICH3 and PNU-282987 per se increased glial cell number in a region-specific manner. In summary, α7 nAChR is involved in oxaliplatin-dependent neuropathology and the agonists (R)-ICH3 and PNU-282987 reduce pain and protect nervous tissue with concomitant glial activation. Since glial cells play a role both in pain and in neuroprotection, an α7 AChR-dependent modulation of glial functions is suggested to distinguish rescue signals from the pathological pain-mediating pathway.

Iodine supplementation during pregnancy and lactation. Position statement of the working group on disorders related to iodine deficiency and thyroid dysfunction of the Spanish Society of Endocrinology and Nutrition.

Severe and mild iodine deficiency during pregnancy and lactation affects thyroid function of the mother and neonate as well as the infant's neuropsychological development. Studies performed in Spain confirm that most women are iodine deficient during pregnancy and lactation. Pregnant and breast feeding women and women planning to become pregnant should take iodine supplements.

Concentration-dependent specimen shrinkage in iodine-enhanced microCT.

Iodine potassium iodide (I2 KI) solution can be employed as a contrast agent for the visualisation of soft tissue structures in micro-computed tomography studies. This technique provides high resolution images of soft tissue non-destructively but initial studies suggest that the stain can cause substantial specimen shrinkage. The degree of specimen shrinkage, and potential deformation, is an important consideration when using the data for morphological studies. Here we quantify the macroscopic volume changes in mouse skeletal muscle, cardiac muscle and cerebellum as a result of immersion in the common fixatives 10% phosphate-buffered formal saline, 70% ethanol and 3% glutaraldehyde, compared with I2 KI staining solution at concentrations of 2, 6, 10 and 20%. Immersion in the I2 KI solution resulted in dramatic changes of tissue volume, which were far larger than the shrinkage from formalin fixation alone. The degree of macroscopic change was most dependent upon the I2 KI concentration, with severe shrinkage of 70% seen in solutions of 20% I2 KI after 14 days' incubation. When using this technique care needs to be taken to use the lowest concentration that will give adequate contrast to minimise artefacts due to shrinkage.

Effect of the source of biofilm bacteria, level of biofilm maturation, and type of disinfecting agent on the susceptibility of biofilm bacteria to antibacterial agents.

INTRODUCTION: Biofilm development is a dynamic process that begins with the initial attachment of planktonic bacteria to a surface, eventually leading through different stages to a mature, structurally complex biofilm. The aim of this study was to assess the effect of the source of biofilm bacteria, the level of biofilm maturation, and the type of disinfecting agent on the susceptibility of biofilm bacteria to antibacterial agents. METHODS: Multispecies biofilms from plaque bacteria of 6 donors were grown for up to 8 weeks on collagen-coated hydroxyapatite disks. After 1, 2, 3, 4, and 8 weeks of growth the biofilms were exposed to 1% sodium hypochlorite, 0.2/0.4% iodine-potassium iodide, and 2% chlorhexidine for 1 and 3 minutes. The percentage of killed biofilm bacteria was determined by using LIVE/DEAD viability staining and confocal laser scanning microscopy. One-way analysis of variance was used for statistical analysis. RESULTS: One- and 2-week-old biofilms were moderately or very sensitive to the tested disinfecting agents, which killed 20%-100% of the biofilm bacteria. After 3 weeks of growth the biofilm bacteria were more resistant to the same agents, and only 10%-30% of the bacteria were killed (P< .001). The same pattern of the effect of biofilm age (maturation) on the resistance of bacteria was observed in all 6 biofilms and with all 3 disinfecting agents. CONCLUSION: The change of biofilm bacteria from sensitive to resistant against disinfecting agents occurred between 2 and 3 weeks of biofilm maturation. This development took place simultaneously in all biofilms grown from plaque bacteria from 6 different donors and was independent of the type of disinfecting agent used. The results emphasize the importance of knowing the maturation timeline of each biofilm model used to test the effectiveness of endodontic disinfecting agents against biofilm bacteria.

Functionalization of natural gum: an effective method to prepare iodine complex.

To overcome the drawbacks associated with iodine e.g. insolubility in water, etc., it has been complexed with polymers that have the ability to bind it. In this study, gum arabic (GA), a natural gum was functionalized to introduce new reactive groups that can easily interact with small molecules followed by iodination in ethanol solution to prepare an iodine complex. The samples were characterized by FTIR, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The synthesized iodine complex was found reddish-brown in colour and stable at room temperature. The interaction of free available iodine with functionalized GA was also studied and established by UV-vis spectrophotometer. The amount of iodine released in water was measured by iodometric titration method and its value compared with the available iodine complex, polyvinylpyrrolidone-iodine complex. The antimicrobial activity of iodine complex was tested against Escherichia coli (Gram negative bacteria) and found to be effective against it.

The effect of detergents on the antibacterial activity of disinfecting solutions in dentin.

INTRODUCTION: Detergents have been added into different disinfecting solutions to lower their surface tension and to enhance their antibacterial effects. The purpose of this study was to evaluate the effectiveness of dentin disinfection by different antibacterial solutions in the presence and absence of detergents using a novel dentin infection model and confocal laser scanning microscopy (CLSM). METHODS: Semicylindrical dentin specimens were infected with Enterococcus faecalis by centrifugation according to a previously described protocol. After 1 day of incubation, the infected dentin specimens were subjected to 1 and 3 minutes of exposure to sterile water, 0.1% cetrimide (CTR), 2% sodium hypochlorite (NaOCl), 2% NaOCl + 0.1% CTR, 6% NaOCl, 6% NaOCl + 0.1% CTR, Chlor-Xtra (Vista Dental, Racine, WI), 2% chlorhexidine (CHX), CHX-Plus (Vista Dental, Racine, WI), 2/4% iodine potassium iodide (IPI), and IPI + 0.1% CTR. The specimens were then stained for bacterial viability and examined by CLSM to analyze the proportions of dead and live bacteria inside dentinal tubules. RESULTS: More bacteria in dentin were killed after 3 minutes of exposure than after 1 minute of exposure to the disinfecting solutions in all experimental groups (P < .05). The antibacterial solutions with detergents (0.1% CTR, 2% NaOCl + 0.1% CTR, CHX-Plus, and IPI + 0.1% CTR) showed a statistically higher proportion of dead bacteria than the corresponding solutions without detergents (sterile water, 2% NaOCl, 2% CHX, and IPI) (P < .05) except for the 6% NaOCl group (6% NaOCl, 6% NaOCl + 0.1% CTR, and Chlor-Xtra) (P > .05). Six percent NaOCl, 6% NaOCl + 0.1% CTR, and Chlor-Xtra were the most effective solutions, killing over 45% and 65% of the bacteria after 1 and 3 minutes of exposure, respectively. Only 3% to 4% of the bacteria were dead in the sterile water group, whereas 0.1% CTR alone was able to kill 24% to 36% of the E. faecalis cells. CONCLUSIONS: The addition of detergents in the disinfecting solutions used in the present study increased their antibacterial effects against E. faecalis in the dentinal tubules. When used alone as a single agent, CTR showed antibacterial effectiveness comparable to 2% NaOCl, 2% CHX, and 2/4% IPI.

Clinical pharmacology, uses, and adverse reactions of iodinated contrast agents: a primer for the non-radiologist.

Iodinated contrast agents have been in use since the 1950s to facilitate radiographic imaging modalities. Physicians in almost all specialties will either administer these agents or care for patients who have received these drugs. Different iodinated contrast agents vary greatly in their properties, uses, and toxic effects. Therefore, clinicians should be at least superficially familiar with the clinical pharmacology, administration, risks, and adverse effects associated with iodinated contrast agents. This primer offers the non-radiologist physician the opportunity to gain insight into the use of this class of drugs.

[Stable iodine as a prophylaxis therapy following exposure to radioactive iodines: pharmacological and pharmaceutical characteristics]. / Iode stable et prévention de la contamination par les iodes radioactifs : données pharmacologiques et pharmaceutiques.

More or less rapid radio-induction of thyroidian cancers is the main pathological consequence of an accidental exposure to ingested or inhaled radioactive iodines following a nuclear power plant accident. The prophylactic administration of potassium iodine in a single oral dose has to be practiced as soon as possible after the nuclear accident. The efficacy of this therapy depends on pharmacokinetics of radioidines. Iodines are rapidly and completely absorbed as iodides. The radioactive iodines, mainly iodine 131, concentrate in the thyroid gland because of a carrier-mediated transport by the Na-I symporter. Administration of stable iodine results in the symporter blockade, which limits the uptake of radioactive iodines by the thyroid and the duration of the internal irradiation. This irradiation will never exceed 3days if the therapy is started between 6h before the accidental exposure and 1h after. The pharmacist asked to dispense the tablets of stable iodine has a important place because, besides his advices on the optimal modalities of taking stable iodine and the risks of unwanted effects, he extend these advices to information on the radioactive risk and on measures of civil and sanitary protection.

The effect of various concentrations of iodine potassium iodide on the antimicrobial properties of mineral trioxide aggregate--a pilot study.

BACKGROUND: Mineral trioxide aggregate (MTA) is a multi-purpose dental material with various uses in dentistry. Iodine potassium iodide (IKI) is the most commonly used iodine compound in endodontics. We aimed to assess the antimicrobial activity of tooth-colored ProRoot MTA combined with IKI. MATERIALS AND METHODS: The antimicrobial activity of IKI was assessed at three concentrations (1%, 2%, and 4%) as the mixing agents combined with MTA against Enterococcus faecalis, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans. For each microorganism, three plates were inoculated with 100 µl of a microbial suspension (McFarland 0.5). Four wells were prepared in each plate. MTA (70 mg) was mixed with any of the three concentrations of IKI (25 µl) or sterile distilled water (25 µl) and placed in each well. The plates were incubated for 24 h at 37°C. Zones of inhibition (ZOI) were measured in millimeters by a blinded observer. Data were analyzed using analysis of variance and the Dunnett t-test. RESULTS: All MTA mixtures with water or IKI solutions showed inhibitory zones. The mean ZOI of each MTA/IKI mixture was not significantly different from MTA/water mixture (P > 0.05). MTA/1% IKI had smaller ZOI than MTA/water against E. coli, E. faecalis, and C. albicans. MTA/2% IKI showed larger ZOI only against P. aeruginosa. MTA/4% IKI showed larger ZOI against P. aeruginosa and E. coli (P < 0.05). CONCLUSIONS: Substitution of IKI solutions (1%, 2%, and 4%) for water did not significantly increase the antimicrobial activity of MTA.

Iodine-based radiographic contrast medium may precipitate metformin-associated lactic acidosis in diabetic patients. A case report, literature review and practical approach.

Lactic acidosis in diabetic patients undergoing metformin therapy is a widely recognized, rare but usually serious adverse event, particularly in presence of comorbidities such as cardiorespiratory disease, sepsis and renal failure. As demonstrated by the case of an elderly woman presented, administration of radiographic iodine-based contrast agents may precipitate lactic acidosis through worsening of renal function. Awareness of this condition, identification of at-risk patients, adequate prevention following published guidelines, early diagnosis and treatment including hemodialysis are necessary to avoid a fatal outcome.

The antimicrobial effect of iodine-potassium iodide after cleaning and shaping procedures in mesial root canals of mandibular molars

The aim of this study was to evaluate the antibacterial activity of 2% iodine potassium iodide (IKI) used as a final rinse after the cleaning and shaping procedures in mesial root canals of mandibular molars infected with Enterococcus faecalis. Seventy two mandibular first molars were used. The root canals were infected with Enterococcus faecalis for 30 days. After the infection procedures, the root canals were cleaned and shaped by using the ProTaper rotary system and manual files. The teeth were randomly assigned to four experimental groups (N=18). In group 1, the root canals were irrigated with sterile distilled water (control). In group 2, the root canals were irrigated with 1% Sodium hypochlorite (NaOCl) during instrumentation. In group 3, root canals were irrigated with 1% NaOCl during instrumentation and a five minute final irrigation using 2 % IKI. In group 4, the root canals were irrigated with 1% NaOCl during instrumentation and a 15 minutes final irrigation with 2 % IKI. Bacteria colony-forming units (CFU) from root canals were semi-quantified and the presence of negative cultures among the groups was compared using Fisher’s test (p < 0,05). The order of effectiveness was: 1% NaOCl plus 2% IKI for 15 minutes (95%), 1% NaOCl plus 2% IKI for 5 minutes (44%), 1% NaOCl (17%) and sterile distilled water (0%). Fisher’s exact test showed a significant difference among the groups (p<0.05). It was concluded that under in vitro conditions, IKI was able to eliminate the Enterococcus faecalis from infected dentin significantly in a 15-minute time frame after the cleaning and shaping procedures.

El objetivo del presente trabajo fue determinar el efecto in vitro del yoduro de potasio yodado al 2% posterior a la preparacion quimiomecanica en conductos radiculares infectados con Enterococcus faecalis. Para este estudio, se emplearon 72 primeras molares inferiores permanentes de humanos, los cuales fueron infectados con Enterococcus faecalis ATCC 29212. Los conductos fueron preparados mediante instrumentacion rotatoria y distribuidos de manera aleatoria en cuatro grupos de acuerdo al irrigante empleado: Grupo 1, agua destilada esteril; Grupo 2, NaOCl al 1%; Grupo 3: NaOCl al 1% IKI al 2% durante cinco minutos; y, Grupo 4: NaOCl al 1% mas IKI al 2% durante 15 minutos. Se tomaron muestras pre y postoperatorias de los conductos y se realizo la semicuantificacion microbiologica de las unidades formadoras de colonias de las bacterias. Fue comparada la presencia de cultivos negativos en los grupos mediante el test de Fisher utilizando un nivel de significancia de p < 0.05. El orden de efectividad para la desinfeccion de los conductos radiculares de mayor a menor fue: NaOCl al 1 % mas IKI al 2% durante 15 minutos (95%), NaOCl al 1% mas IKI al 2% durante 5 minutos (44%), NaOCl al 1% (17%) y agua destilada (0%). Se concluye, que bajo las condiciones in vitro de este estudio, el yoduro de potasio yodado empleado despues de la instrumentacion fue capaz de eliminar significativamente a la bacteria Enterococcus faecalis en un tiempo de 15 minutos.

Reactivity of Langerhans cells after application of different chemicals--an ultrastructural analysis.

The goal of this study was to investigate changes in epidermal Langerhans cells after application of different chemicals (acetone, 60% alcohol, 5% nickel sulphate, iodisole, and 0.1% 2,4-dinitrochlorobenzene) on the skin of volunteers. The skin of eight volunteers was treated with acetone, 60% alcohol, iodisol, 5% nickel sulphate, and 0.1% 2,4-dinitrochlorobenzene (DNCB). After application of DNCB, Langerhans cells (LCs) showed increased accumulation of Birbeck granules (Bgs). Alcohol and nickel sulphate caused alternative changes, mainly cytoplasmic vacuolation, in LCs. Nickel sulphate was even responsible for the disappearance of dendrites. Both chemicals have cytotoxic effects on LCs: cytoplasmic organelles and Bgs disappear and subsequently, the antigen-presenting activity of epidermal LCs is inhibited. We did not found any morphological changes in LCs after application of acetone.