C-reactive protein and orosomucoid determinations in a neonatal pathology unit

We report the result of CRP and ORM assays performed at the admission in the unit, in 157 neonates (NN). The NN were divided into 3 groups: 122 "controls" (group I), 21 having septicemia with or without meningitis but with symptoms of infection (group II), 16 having a positive blood culture without symptom of infection (group III). In group I, the CRP level does not depend on gestational age at birth, neither on the age at the assay. The level of ORM depends on both factors. Neonatal infection leads to a very significant rise of the CRP rate (often above 100 mg/l). The rise of ORM is not so dramatic. These data suggest that the assay of these two proteins are useful in the diagnosis of neonatal infection if they are performed together and at several times.     

The role of mast cell-derived histamine in the closure of an in vitro wound

We have previously reported that mast cells (MC) stimulate 3T3 fibroblast migration and proliferation into an in vitro model of wound obtained by producing in a confluent 3T3 monolayer, a midline cut and by scraping the cells from half of the monolayer. The purpose of the present study was to determine the contribution of mast cell-derived histamine to this MC increasing effect. Histamine levels in supernatants of MC/3T3 cultures unactivated or activated with either compound 48/80 or anti-IgE antibodies (10 min) did not correlate to the degree of fibroblast migration and proliferation into the wound space (42h). Various concentrations of histamine were added to 3T3 fibroblast monolayers in the absence of cocultured MC, and fibroblasts beyond the wound line were counted (42 h). Addition of 100 ng/ml histamine had the highest stimulating effect on fibroblast numbers. This effect was abrogated by the addition of cimetidine (an H-2 antagonist). Addition of cimetidine to unactivated MC/3T3 cultures did not affect the increasing activity of MC presence on the wounded monolayer, although it diminished the enhancing effect obtained after MC activation with compound 48/80. These results indicate that histamine is partially responsible for the mast cell enhancing effect on fibroblast migration and proliferation in an in vitro model of wound.accepted by W. Lorenz     

Anterior esthetic fixed appliances for the preschooler: considerations and a technique for placement

One of the pediatric dentist's greatest restorative challenges is the esthetic rehabilitation of a young toddler who has suffered multiple tooth loss subsequent to rampant early childhood caries or extensive dental trauma. An anterior esthetic appliance may be used to replace lost teeth. The most decisive factor for placing an anterior esthetic appliance is parental desire. Other considerations include: space maintenance, masticatory function, speech development, and tongue habits. However, there is no strong evidence that early loss of maxillary incisors will have any significant, long lasting effect on the growth and development of the child. This paper discusses in detail one type of fixed anterior esthetic appliance and the considerations to be made when deciding when and why to place them.     

In Vitro Antibacterial Activity of Acyl-Lysyl Oligomers against Helicobacter pylori

The gastric pathogen Helicobacter pylori has developed resistance to virtually all current antibiotics; thus, there is a pressing need to develop new anti-H. pylori therapies. The goal of this work was to evaluate the antibacterial effect of oligo-acyl-lysyl (OAK) antimicrobial peptidomimetics to determine if they might represent alternatives to conventional antibiotic treatment of H. pylori infection. A total of five OAK sequences were screened for growth-inhibitory and/or bactericidal effects against H. pylori strain G27; four of these sequences had growth-inhibitory and bactericidal effects. The peptide with the highest efficacy against strain G27, C₁₂K-2β₁₂, was selected for further characterization against five additional H. pylori strains (26695, J99, 7.13, SS1, and HPAG1). C₁₂K-2β₁₂ displayed MIC and minimum bactericidal concentration (MBC) ranges of 6.5 to 26 μM and 14.5 to 90 μM, respectively, across the six strains after 24 h of exposure. G27 was the most sensitive H. pylori strain (MIC = 6.5 to 7 μM; MBC = 15 to 20 μM), whereas 26695 was the least susceptible strain (MIC = 25 to 26 μM; MBC = 70 to 90 μM). H. pylori was completely killed after 6 to 8 h of incubation in liquid cultures containing two times the MBC of C₁₂K-2β₁₂. The OAK demonstrated strong in vitro stability, since efficacy was maintained after incubation at extreme temperatures (4°C, 37°C, 42°C, 50°C, 55°C, 60°C, and 95°C) and at low pH, although reduced killing kinetics were observed at pH 4.5. Additionally, upon transient exposure to the bacteria, C₁₂K-2β₁₂ showed irreversible and significant antibacterial effects and was also nonhemolytic. Our results show a significant in vitro effect of C₁₂K-2β₁₂ against H. pylori and suggest that OAKs may be a valuable resource for the treatment of H. pylori infection.Helicobacter pylori is a microaerophilic gram-negative bacterium that colonizes the gastric mucosa. It is known to be a principal gastric pathogen of humans and is associated with the development of gastritis, gastric ulcers, duodenal ulcers, and gastric cancer (46, 55, 56, 60). Approximately half of the world''s population is infected with H. pylori (79). Thus, the bacterium poses a significant public health problem, which is further compounded by the fact that H. pylori has developed antimicrobial resistance to virtually all current antibiotics, a phenomenon that is hampering efforts to treat the infection (40, 51).Since the original isolation of H. pylori in the early 1980s, treatment of the bacterial infection has undergone a significant evolutionary development from initial monotherapy to dual, triple, and in more recent trials quadruple therapy (8, 18). Current treatment strategies employ combination therapy, since single-antibiotic therapy often results in failure to eradicate the infection (21). The highest H. pylori eradication rates have been reported with triple therapy, which involves the utilization of two antibiotics in combination with bismuth or a proton pump inhibitor, PPI (34, 44). Amoxicillin (amoxicilline) with either clarithromycin or metronidazole is often the antibiotic combination of choice as a first- or second-line treatment regimen, respectively. However, in recent years the efficacy of the standard first-line triple therapy has also been decreasing dramatically, mainly due to development of resistance to the drugs (35, 59). Failure to cure H. pylori infection has been noted for more than 20 to 30% of patients (37). In addition, several studies have found an eradication rate lower than 75% (6, 11, 59), and values as low as 25 to 45% have also been recently reported (22, 24). Thus, prolonged standard triple therapy for up to 2 weeks has been recommended (9, 23, 34), and in cases of eradication failure, a quadruple therapy with a proton pump inhibitor, bismuth salt, tetracycline, and metronidazole has been advised as a second-line therapy (8, 13, 44). More recently, sequential therapy (PPI and amoxicillin for 5 days, followed by PPI, clarithromycin, and tinidazole for 5 days) has become very attractive for clinical practice since impressive efficacy was seen (36, 73). However, broad adoption of this strategy as standard first-line therapy for H. pylori infection is still debatable because of impending validation in other geographic locations and studies to demonstrate efficacy superior to that of quadruple therapy, which is still considered a simpler regimen than sequential therapy (74). Of note, all the aforementioned therapies including sequential therapies employ multiple drugs and relatively complex regimens for the treatment of H. pylori infection, hence the search for new/better antibiotics.The bactericidal activity of amoxicillin results from interference with the interpeptide linkage of peptidoglycan by binding to penicillin binding proteins and blocking their function as transporters during cell wall synthesis. Clarithromycin, like other macrolides, binds to the 50S subunit of bacterial ribosomes, thus inhibiting translocation of tRNA during translation. Binding of clarithromycin to H. pylori ribosomes has been shown to be very strong and is irreversible (27). Finally, metronidazole is a 5-nitroimidazole drug whose mode of action is mediated by nitro metabolites, such as the radical anion (NO₂·⁻) and perhaps nitroso (RNO) and hydroxylamine (RNHOH) derivatives (39). Such metabolites have been demonstrated to cause DNA damage that results in cell death.H. pylori resistance to amoxicillin is very rare, while resistance to clarithromycin varies significantly and may range from 10 to 25% (14). However, in a recent study, it was reported that the first-line anti-H. pylori triple therapies containing clarithromycin failed in 7 to 49% of patients (19, 26), indicating the underlying significant increase in antimicrobial resistance and occurrence of refractory H. pylori infections (32, 50, 78). Currently, PPI-amoxicillin-metronidazole triple therapy is highly effective as a second-line regimen for the treatment of H. pylori infection in patients showing failure of the first-line regimen (PPI-amoxicillin-clarithromycin) (47). However, high rates of resistance have been reported for people with a history of metronidazole treatment (49). Given the immense challenge in rising antimicrobial resistance (38), there is an enormous need for new antibiotics for the treatment of H. pylori infection.One of the pharmacodynamic parameters most studied for antibiotics is the postantibiotic effect (PAE), which describes the suppression of bacterial growth after a short exposure of bacteria to an antimicrobial agent (29). From a clinical standpoint, PAE provides a rationale for the modification of the dosing interval of antimicrobials and could be significant for the optimization of a treatment regimen and the minimization of drug-induced adverse effects. Similarly, the success of intermittent dosing with drugs that exhibit short half-lives has been attributed to the presence of significant PAE. A long and/or positive PAE is considered an attractive characteristic for an effective new antibiotic.In the last decade, antimicrobial peptides (AMPs) have attracted attention as potential therapeutic agents mainly due to their ability to be promptly synthesized by the host upon induction and their capacity to subsequently lyse cell membranes of pathogens through direct interaction with them. Hence, AMPs are recognized as a cell-free host defense mechanism and are important component of the innate immune systems of living organisms, including plants (76), insects (30), amphibians (75), and mammals (80). These natural membrane-lytic peptides display immense diversity in terms of sequence, secondary structural motifs, charge (cationic and anionic), and/or the abundance of certain specific amino acids (16, 66). Despite the immense diversity, a common feature for cationic AMPs is that they all form amphipathic structures that allow them to bind to the membrane interface of microbes (5, 69). Peptides which are not cationic are known to exhibit less selectivity toward microbes than toward mammalian cells, since electrostatic interactions are critical for initial binding of the peptide to membrane containing anionic lipids (45).Oligomers of acylated lysines (OAKs) constitute a novel class of synthetic AMP mimics that consists of alternating amino acyl chains and cationic amino acids arranged to create an optimal molecular charge and hydrophobicity for enhanced potency (61, 65). This design has been reported to be advantageous over conventional AMPs by allowing the capacity for fine-tuning of the OAK structure to enhance potency against a broad spectrum of organisms while being devoid of apparent toxicity against mammalian cells (62, 64). This selective activity has been attributed to a design that lacks the secondary structures present in natural peptides (63) and to a mode of action that appears to target multiple sites, such as membranes and DNA (64). Circular dichroism studies of OAKs have demonstrated that they lack secondary structure in the presence of liposomes or hydrophobic media such as trifluoroethanol and sodium dodecyl sulfate (63). Additional characterization of OAKs with microbial pathogens other than H. pylori has demonstrated significant stability in the presence of serum and serum components and has shown no hemolysis of host erythrocytes (64). Two recent in vivo studies have also shown that administration of OAKs protected mice from an Escherichia coli lethal challenge (63, 64). Therefore, OAKs display characteristic features that are attractive for the development of a potent therapeutic drug.Given the increasing antibiotic resistance rates of H. pylori and the current complicated treatment regime, the need for new potent antibiotics has never been greater. Given the potent effect of OAKs on other pathogens, we investigated the in vitro antibacterial activities of five representative OAKs against H. pylori. The selected sequences belong to two distinct groups: one group consisted of C₁₂K-7α₈ and its shorter analog, C₁₂K-5α₈, two-well characterized compounds (15, 63, 64) both of which are known for potent activity against gram-negative bacteria (25); the second group consisted of the less-characterized OAKs C₁₂K-2β₁₂ and two shorter analogs, C₁₂-2β₁₂ and 2β₁₂, for which a preliminary study (62) predicted broad-spectrum activities at least for the longer analogs. Together, these representative OAKs were anticipated to provide a preliminary structure-activity assessment on the potential activity of OAKs against H. pylori. Our results indicate that four of the tested peptides show efficacy against the pathogen. Of these, C₁₂K-2β₁₂ demonstrated the most potent activity, was active against a spectrum of strains, and was remarkably stable at low pH and after exposure to extreme temperatures.     

First-choice treatment alternatives for caries removal using the chemomechanical method.

Modern dentistry aims to preserve tooth structure using minimally invasive procedures. Chemomechanical removal of caries is a new method with the advantage of selective removal of severely demineralized dentin. In addition, the method enhances the clinician's ability to diagnose caries. Ensuring chairside caries diagnosis and removal, based on biologic principle, helps to preserve as much healthy tissue as possible. However, while this method is most comfortable for the patient, treatment time is prolonged. In most cases, the method has to be used in combination with a conventional bur. Also, caries lesions in which removal of enamel or a restoration is needed cannot be treated exclusively using the chemomechanical method. This article describes the mechanism of action of the chemomechanical method (CarisolvTM) for caries removal. Indications for use of the chemomechanical method as a first-choice treatment are presented. Clinical cases in which this new approach provides a significant clinical advantage are also described.     

Comparison of oral midazolam with and without hydroxyzine in the sedation of pediatric dental patients

PURPOSE: The purpose of this study was to compare the effectiveness of midazolam (MDZ) alone to a combination of MDZ and hydroxyzine (MDZH) when sedating young children for dental treatment. METHODS: This was a prospective, double-blinded, crossover clinical study of young uncooperative children in need of at least 2 restorative visits. Twenty-eight children, ages 21 to 56 months, with a mean age of 36.6 months, participated in this study. The subjects were assigned randomly to receive either 0.5 mg/kg of oral MDZ 20 minutes prior to the beginning of dental treatment or the combination of 0.3 mg/kg oral MDZ with 3.7 mg/kg of hydroxyzine 30 minutes before treatment. The alternative drug regimen was administered at the second appointment. All subjects also received 50% nitrous oxide and were restrained with a papoose board. The child's behavior (quiet or crying, relaxed or moving) was evaluated every 5 minutes by an experienced pediatric dentist who was unaware of the drug given to the child. At the conclusion of treatment, each session was evaluated for overall effectiveness. RESULTS: Regardless of the type of premedication, more patients exhibited quiet behavior at the beginning of treatment, with an increase in crying and movement toward the end of treatment. Regarding movement, a significant difference was observed during the first 20 minutes between the 2 regimens. MDZ showed more children exhibiting movement. During the first 30 minutes of treatment, more children cried in the MDZ group, while MDZH presented more children asleep or quiet. No significant differences were found in behavior as a function of the order the sedative regimens were given. No significant differences between the 2 regimens regarding overall behavior and success (t=0.655 at 27 degrees of freedom; P=.518) were found. CONCLUSIONS: The combination of hydroxyzine (3.7 mg/kg) with MDZ (0.3 mg/kg) administered 30 minutes before treatment resulted in safe and effective sedation for the dental treatment of young children. This combination's use might be more advantageous when compared to MDZ alone, resulting in less crying and movement during the first 30 and 20 minutes, respectively.     

Strap him down or knock him out: Is conscious sedation with restraint an alternative to general anaesthesia?

When confronting a defiant or pre-co-operative young patient with extensive dental decay the dentist must decide between treatment under conscious sedation with passive restraint or general anaesthesia. Although some practitioners prefer to attempt and exhaust sedative techniques in most cases and use general anaesthesia as a last resort, many others do not mandate that alternate approaches first be attempted before treating under general anaesthesia and routinely recommend it as their first choice. What are the considerations involved in this decision-making process? Should the use of conscious sedation with restraint be revisited and perhaps even be considered the preferred method? What is the role of the dentist in the decision-making process? The purpose of this opinion-based paper is to present to the UK dentist a dilemma that paediatric dentists face in the US and in other countries as well and allow the reader to establish an opinion.     

Oxidative stress in Cohen diabetic rat model by high-sucrose, low-copper diet: inducing pancreatic damage and diabetes

Increased oxidative stress contributes to the development and progression of both types of diabetes mellitus (DM) and its complications. In the Cohen diabetic (CD) rats, a known genetic model of nutritionally induced type 2 DM, a high-sucrose, low-copper diet (HSD) induces within 4 weeks DM in the sensitive (CDs) rats but not in the resistant (CDr) rats. To assess the possible involvement of oxidative stress in the induction of DM, we studied the effect of HSD on the tissue levels of antioxidants and the extent of oxidative injuries in these animals in comparison with the regular outbred strain of nondiabetic Sabra rats. The specific aims were to investigate, at the onset of HSD-induced DM, (1) the extent of oxidative injury, as reflected by levels of malondialdehyde and protein carbonyl groups; (2) the overall antioxidant capacities to cope with increased oxidative stress; and (3) the modification of oxidative damage biomarkers in various tissues of CDr, CDs, and Sabra rats. Female CDs, CDr, and Sabra rats were fed regular diet or HSD for 4 to 5 weeks; and several parameters of oxidative injuries and antioxidant levels were determined. Changes in the levels of nonenzymatic low-molecular weight antioxidants (LMWAs) were measured by cyclic voltammetry and oxygen radical absorbance capacity. The activities of the antioxidant enzymes superoxide dismutase and catalase were measured. Oxidative damage was evaluated by measuring lipid peroxidation and protein oxidation. (1) In all animals fed HSD, the levels of LMWAs were decreased in most organs, although not plasma. (2) A significant difference was consistently found in antioxidant enzymes' activities in the pancreas of HSD-fed CDs rats, but not in other tissues. (3) The activities of superoxide dismutase and catalase and the levels of malondialdehyde and protein carbonyl group increased, whereas the levels of LMWAs decreased, in the pancreas of HSD-fed CDs rats. In the CD rats that develop DM when fed HSD, the pancreas showed susceptibility to oxidative stress-induced injuries. Thus, enhanced oxidative stress seems to play a role in the pathogenesis of DM in this strain.     

In vitro antiplasmodium effects of dermaseptin S4 derivatives

The 13-residue dermaseptin S4 derivative K(4)S4(1-13)a (P) was previously shown to kill intraerythrocytic malaria parasites through the lysis of the host cells. In this study, we have sought peptides that will kill the parasite without lysing the erythrocyte. To produce such peptides, 26 compounds of variable structure and size were attached to the N terminus of P and screened for antiplasmodium and hemolytic activities in cultures of Plasmodium falciparum. Results from this screen indicated that increased hydrophobicity results in amplified antiplasmodium effect, irrespective of the linearity or bulkiness of the additive. However, increased hydrophobicity also was generally associated with increased hemolysis, with the exception of two derivatives: propionyl-P (C3-P) and isobutyryl-P (iC4-P). Both acyl-peptides were more effective than P, with 50% growth inhibition at 3.8, 4.3, and 7.7 microM, respectively. The antiparasitic effect was time dependent and totally irreversible, implying a cytotoxic effect. The peptides were also investigated in parallel for their ability to inhibit parasite growth and to induce hemolysis in infected and uninfected erythrocytes. Whereas the dose dependence of growth inhibition and hemolysis of infected cells overlapped when cells were treated with P, the acyl-peptides exerted 50% growth inhibition at concentrations that did not cause hemolysis. Noticeably, the acyl derivatives, but not P, were able to dissipate the parasite plasma membrane potential and cause depletion of intraparasite potassium under nonhemolytic conditions. These results clearly demonstrate that the acyl-peptides can affect parasite viability in a manner that is dissociated from lysis of the host cell. Overall, the data indicate the potential usefulness of this strategy for development of selective peptides as investigative tools and eventually as antimalarial agents.