Esthetic comparison of white-spot lesion treatment modalities using spectrometry and fluorescence

Objective:To compare the esthetic improvements of white-spot lesions (WSLs) treated by fluoride, casein phosphopeptide amorphous calcium phosphate (CPP-ACP), or resin infiltration.Materials and Methods:WSLs were created on human enamel and randomly assigned to four groups: NaF (500 ppm), CPP-ACP, resin infiltration (Icon), or distilled deionized water (DDW; control group). The color change (ΔE) of each specimen was measured with a Crystaleye spectrophotometer, and fluorescence loss (ΔQ) was measured by quantitative light-induced fluorescence (QLF), at different time points after treatment: baseline (0 weeks), 2 weeks, 4 weeks, and 6 weeks.Results:The ΔE and ΔQ baseline values for the four groups before the treatments did not differ significantly. Icon treatment improved the WSL color significantly and gave the lowest ΔE (2.9 ± 1.2 on average) compared with other treatments (P < .01). The Icon treatment also resulted in a significant change in the ΔQ of WSLs compared with baseline (P < .01). In the NaF and CPP-ACP treatment groups, ΔQ showed significant recovery compared with the baseline values only after 4 weeks after treatment (P < .05).Conclusions:Resin infiltration is more effective than NaF or CPP-ACP in providing esthetic improvement of WSLs.     

Guidelines on clinical presentation and management of nondystrophic myotonias

The nondystrophic myotonias are rare muscle hyperexcitability disorders caused by gain-of-function mutations in the SCN4A gene or loss-of-function mutations in the CLCN1 gene. Clinically, they are characterized by myotonia, defined as delayed muscle relaxation after voluntary contraction, which leads to symptoms of muscle stiffness, pain, fatigue, and weakness. Diagnosis is based on history and examination findings, the presence of electrical myotonia on electromyography, and genetic confirmation. In the absence of genetic confirmation, the diagnosis is supported by detailed electrophysiological testing, exclusion of other related disorders, and analysis of a variant of uncertain significance if present. Symptomatic treatment with a sodium channel blocker, such as mexiletine, is usually the first step in management, as well as educating patients about potential anesthetic complications.     

Pancreatic pseudocysts: Cause, therapy, and results

Sixty-nine patients with pancreatic pseudocysts were reviewed. Chronic alcohol abuse was associated with pancreatitis in 78 percent of the patients. Presenting signs and symptoms were nonspecific. Ultrasonographic and computerized axial tomographic scans were most commonly used to established the diagnosis. Twenty patients were managed conservatively and resolution occurred in 11 of these patients. Forty-nine patients underwent operation. Internal drainage was performed on 31 occasions in 29 patients, and external drainage was performed in 11. In addition, pancreatic resection was carried out in 8 patients, and needle aspiration in 2 patients. Infected pseudocysts were present in 11 patients. Complications occurred in 18 patients in the operated group and 2 patients died (4 percent). There was recurrence of pseudocysts in 10 patients. Our results suggest that pseudocysts remain a common complication of pancreatitis, and infected pseudocysts are the major cause of postoperative morbidity. Computerized axial tomography and ultrasonography are the mainstays of diagnosis. Surgical therapy is safe, but continues to be associated with significant rates of morbidity and recurrence. When pseudocysts recur, they are generally anatomically distant from the original lesion and probably represent new disruptions of the pancreatic duct.     

Antifungal drug resistance of oral fungi

Fungi comprise a minor component of the oral microbiota but give rise to oral disease in a significant proportion of the population. The most common form of oral fungal disease is oral candidiasis, which has a number of presentations. The mainstay for the treatment of oral candidiasis is the use of polyenes, such as nystatin and amphotericin B, and azoles including miconazole, fluconazole, and itraconazole. Resistance of fungi to polyenes is rare, but some Candida species, such as Candida glabrata and C. krusei, are innately less susceptible to azoles, and C. albicans can acquire azole resistance. The main mechanism of high-level fungal azole resistance, measured in vitro, is energy-dependent drug efflux. Most fungi in the oral cavity, however, are present in multispecies biofilms that typically demonstrate an antifungal resistance phenotype. This resistance is the result of multiple factors including the expression of efflux pumps in the fungal cell membrane, biofilm matrix permeability, and a stress response in the fungal cell. Removal of dental biofilms, or treatments to prevent biofilm development in combination with antifungal drugs, may enable better treatment and prevention of oral fungal disease.     

Physiological traits associated with success of Candida albicans strains as commensal colonizers and pathogens.

DNA fingerprinting with the moderately repetitive sequence Ca3 has repeatedly identified groups of genetically similar strains of Candida albicans that are more frequently isolated than other groups of strains from human hosts in a geographical locale. Members of these groups are found in approximately 30% of healthy individuals and in up to 70% of patients suffering from candidiasis. The high prevalence of these strains implies that they are more successful in colonizing human hosts and in causing disease than other strains (J. Schmid, Clin. Adv. Treatment Fungal Infect. 4(6):12-16, 1993). In the present study, we have compared one such group of highly prevalent strains with other strains from the same locale to identify physiological traits a larger number of chemicals than other strains in a resistogram assay. When resistance to individual chemicals used in the resistogram assay was analyzed, strains from the group of highly prevalent strains were significantly more often resistant to boric acid, cetrimide, chlorhexidine, 5-fluorocytosine, and high sodium chloride concentrations than other strains. Strains from the group of highly prevalent strains also adhered significantly (1.5 times) better to saliva-coated surfaces than did other strains. Because members of highly prevalent groups of strains are the most common infectious agents in candidiasis, these physiological traits may be involved in determining not only the success of C. albicans in colonizing human hosts in general but also its ability to cause disease. Sodium chloride resistance and increased adherence were also associated with infectious isolates outside the group of highly prevalent strains, indicating that they may be of particular importance in pathogenesis.     

Confirmation of association of protein I serotype of Neisseria gonorrhoeae with ability to cause disseminated infection

Previous work indicates that strains of Neisseria gonorrhoeae isolated in Seattle, Wash., and Atlanta, Ga., show an association between serotypes 1 and 2 of protein I of the outer membrane and the ability to cause disseminated infection (T.M. Buchanan and J.F. Hildebrandt, Infect. Immun. 32:985-994, 1981). By using the same serotyping system, we confirmed the association between those serotypes and both disseminated infection and serum resistance in strains from North Carolina. Some strains of the same serotype had protein I species with different apparent molecular weights.     

Chronic adolescent exposure to delta-9-tetrahydrocannabinol in COMT mutant mice: impact on indices of dopaminergic, endocannabinoid and GABAergic pathways

Cannabis use confers a two-fold increase in risk for psychosis, with adolescent use conferring an even greater risk. A high-low activity polymorphism in catechol-O-methyltransferase (COMT), a gene encoding the COMT enzyme involved in dopamine clearance in the brain, may interact with adolescent cannabis exposure to increase risk for schizophrenia. The impact of such an interaction on central neurotransmitter pathways implicated in schizophrenia is unknown. Male mice with knockout of the COMT gene were treated chronically with delta-9-tetrahydrocannabinol (THC) during adolescence (postnatal day 32-52). We measured the size and density of GABAergic cells and the protein expression of cannabinoid receptor 1 (CB1R) in the prefrontal cortex (PFC) and hippocampus (HPC) in knockout mice relative to heterozygous mutants and wild-type controls. Size and density of dopaminergic neurons was also assessed in the ventral tegmental area (VTA) across the genotypes. COMT genotype × THC treatment interactions were observed for: (1) dopaminergic cell size in the VTA, (2) CB1R protein expression in the HPC, and (3) parvalbumin (PV) cell size in the PFC. No effects of adolescent THC treatment were observed for PV and dopaminergic cell density across the COMT genotypes. COMT genotype modulates the effects of chronic THC administration during adolescence on indices of neurotransmitter function in the brain. These findings illuminate how COMT deletion and adolescent cannabis use can interact to modulate the function of neurotransmitters systems implicated in schizophrenia.