Obtaining scratch-free specimens of dental enamel prepared by sectioning, grinding, polishing, and acid etching for scanning electron microscopy.

The aim of the present study was to identify the stage during acid etching of dental enamel where scratches introduced by sectioning and grinding procedures were eliminated. Nitric acid was used as etchant. Four hundred 2-3 mm-thick longitudinal sections of human third molar crowns were assigned to 80 groups, each group differing with respect to grinding procedure (silicon carbide paper grit 600; 1,000; 1,200; and 1,200 + polishing), acid concentration (0.1%, 1%, 2.5%, and 5%) and etching time (15, 30, 45, 90, and 180 s). Observation of the specimens with scanning electron microscopy (SEM) showed that elimination of scratches was facilitated by increasing fineness of grinding paper and polishing, and by increasing acid concentration and increasing etching time. An acid concentration of 0.1% did not remove scratches totally irrespective of grinding procedure or etching time, 1% acid removed most scratches after 45-90 s, while 2.5% and 5% acids removed most scratches after 30-45 s. It is proposed that the scratches are eliminated/obscured through a combined effect of the acid and the inherent structure of the enamel. The results of the present study may serve as a guide in choosing the best procedures for obtaining scratch-free enamel surfaces through acid etching with the least possible loss of enamel substance. Research highlights Sectioning and grinding produce scratches in dental enamel. Scratches are eliminated by acid etching prior to SEM studies of enamel structure. Scratch elimination increases with increasing acid strength and etching time and is facilitated by finer grit grinding paper and polishing.

Efficacy and tolerability of nitric-zinc complex in the treatment of external genital warts and "difficult-to-treat" warts: a "proof of concept", prospective, multicentre, open study.

AIM: Treatment of plantar and periungueal warts (so called "difficult-to-treat" warts, DTW) and external genital warts (EGW) remains unsatisfactory. Medical or invasive procedures are partially effective and/or painful. Furthermore recurrences rates after treatments are still a relevant problem for all the available therapies. Nitric-zinc complex is a solution for topical application containing nitric acid, zinc, copper and organic acids able to induce a caustic effect of the wart trough mummification and proteins denaturation/coagulation action. Nitric-zinc complex has been shown to be an effective and well tolerated treatment of common warts. METHODS: We evaluated in a prospective open label 4-centre trial, the efficacy and local tolerability of nitric-zinc complex in the treatment of EGW and DTW. A total of 37 immunocompetent subjects (20 men and 17 women; mean age: 45 years) with single or multiple lesions, were enrolled, after their informed consent. A total of 30 subjects had EGW, 2 subjects had plantar warts, 2 warts of the hand and 3 periungueal lesions. Nitric-zinc aqueous solution was applied topically using a 30 mL capillary tube over the lesions until a whitening/yellowish reaction appeared. A second (or more, if needed) application was performed at two-week interval until a complete clinical cure rate was observed. Primary outcome of the study was the clinical evaluation with picture documentation of the evolution of lesions classified as total cure, partial disappearance or no effect. Topical tolerability was evaluated through patient's reported adverse events. RESULTS: All subjects completed the study. A complete cure of lesions was observed in 31 subjects (90%) after one and up to four applications. Three patients with EGW (8%) showed a partial disappearance of lesions and one (2%) subject was no responder to four nitric-zinc complex applications. The product was well tolerated. No serious adverse events were observed or recorded. CONCLUSION: Nitric-zinc complex topical solution has shown to be an effective and well tolerated treatment of EGW and "difficult-to-treat" warts with a 90% of subjects with a total cure after one or up to four applications. A total or partial response was observed in 99% of the subjects. Nitric-zinc complex could be considered an easy-to-use effective treatment strategy of "difficult-to-treat" warts and external genital warts. Additional studies comparing nitric-zinc complex to other strategies are warranted.

Assessment of the efficacy of a new formulation for plantar wart mummification: new experimental design and human papillomavirus identification.

Cutaneous warts are caused by infection of the epidermis with human papillomavirus (HPV). Cryotherapy using liquid nitrogen is one of the most common local treatments. In this study, we used a novel ex vivo approach to compare the efficacy of a new product with conventional liquid-nitrogen cryotherapy by studying epidermal histology and assessing the presence of HPV types 1 and 2 DNA in plantar warts. The studied formulation, which acts by tissues mummification, is a combination of nitric acid, organic acids and metallic salts. We found that, similar to liquid nitrogen, the studied product induced alterations in the wart structure. In addition, unlike liquid nitrogen, this product also reduced the amount of HPV DNA. The results suggest that there is a poor correlation between the histological response and the antiviral efficacy of standard wart treatment.

Calcium silicate coating derived from Portland cement as treatment for hypersensitive dentine.

OBJECTIVES: To evaluate the in vitro effectiveness on dentine permeability and dentine morphology of a calcium silicate treatment based on Portland cement (DSC). METHODS: The experimental treatment consisted of a calcium silicate paste based on Portland cement that was applied on dentine surface for 3 min. A professional re-mineralizing treatment (GC Tooth Mousse), two in office desensitizing agents (D/Sense Crystal, and By Sealant) and a commercial toothpaste Dentosan S were studied as comparison materials. All materials were applied accordingly with manufacturer directions on wet dentine. The quantitative changes in the hydraulic conductance i.e., permeability through tubules of dentine discs samples produced by treatment were quantified in vitro using a hydrostatic device working at 6.9 kPa. SEM/EDX analyses of dentine were carried out to obtain qualitative information on dentine morphology and surface deposits and to study their relationship with the hydraulic conductance. After treatment, each dentine sample was immersed in artificial saliva and permeability re-evaluated. Finally, each sample was exposed to 0.02 M citric acid solution and the final permeability was assessed. RESULTS: The experimental treatment and both oxalate-based products (D/Sense Crystal and By Sealant) significantly decreased dentine permeability and created crystals and precipitates on the dentine surface that reduced the diameter of dentinal tubules. Artificial saliva immersion and citric acid challenge increased dentine permeability and partially modified the treated surfaces. Dentosan S and GC Tooth Mousse treatments partially reduced dentine permeability and created small amount of precipitates that were removed by saliva immersion and citric acid exposure. EDX revealed the presence of calcium-rich layer after DSC experimental treatment. CONCLUSIONS: The application of the experimental calcium silicate paste and oxalate-based treatments was determined to be effective on dentine permeability reduction and tubules occlusion. The clinical use as desensitizing agent of materials derived from Portland cement as desensitizing agent should be considered for dentine hypersensitivity treatment.

Medicina regenerativa en andrología: Ingeniería Tisular y terapia génica como posibles opciones de tratamiento para las deformaciones peneanas y la disfunción eréctil / Regenerative medicine in andrology: tissue engineering and gene therapy as potential treatment options for penile deformations and erectile dysfunction

Se están investigando la ingeniería tisular y la terapia génica en estudios en animales para reconstruir el tejido peneano o tratar la disfunción eréctil. En esta revisión se pretende examinar estos esfuerzos experimentales de los últimos años y se intenta ofrecer una breve introducción a la metodología básica de estas nuevas técnicas del campo de la medicina regenerativa

Tissue engineering and gene therapy are currently investigated in animal studies for reconstructing penile tissue or treating erectile dysfunction. This review aims to ecamine these experimental efforts from the last years and tries to give a brief introduction to the basic methodology of these new techniques from the field of regenerative medicine

Oxido nítrico: ensayo clínico en niños con hipertensión pulmonar grave en el post-operatorio de cardiopatías congénitas / Nitric oxide: clinical trial in children with severe pulmonary hypertension after cardiac surgery for congenital heartdisease

jetivo: evaluar en un ensayo clínico a muestras relacionadas la respuesta al óxido nítrico (NO) en niños con hipertensión pulmonar (HP) grave post cirugía cardiovascular. Pacientes y Métodos: 24 pacientes (5 por ciento) internados en la unidad de recuperación cardiovascular entre agosto de 1996 y agosto de 1997 recibieron NO inhalado por padecer HP grave postoperatoria y fracaso al tratamiento convencional. Las indicaciones se categorizaron en 4 grupos: 1) Tratamiento con monitoreo directo de la presión arterial pulmonar (PAP). 2) Sin monitoreo directo, con evaluación clínica y ecocardiográfica. 3) Con gradiente transpulmonar >15 mmhg. 4) Uso preventivo. Se controlaron presión arterial y pulmonar, gases en sangre antes y después de la administración, metahemoglobinemia cada 12 hs, control ambiental de NO y NO2 cada 4 hs y ecocardiograma pre y post-no. En el análisis estadístico se compararon los valores de la pao2 antes y después de la administración del NO utilizando el wilcoxon rank test para dos colas (gpis).Se consideró significativa una p<0.05. Resultados: la mediana de edad fue de 8.7m, y la de peso de 4.2 kg., la mediana del tiempo de administración fue 69 hs (2-317 hs) con una dosis máximapromedio de 26 +- 22 ppm. Diez y nueve pacientes (80 por ciento) tuvieron una respuesta favorable; en 12 de ellos se observó un incremento de la pao2 basal superior al 30 por ciento. La mediana de la pao2 previa fue de 94 torr (r=36-428) con una posterior de 155 torr (r=34-683), p=0.009. Los niveles promedio de metahemoglobinemia fueron de 2 por ciento. Los niveles de NO y NO2 ambientales fueron menores de 1 ppm. No se observaron fenómenos de hipotensión arterial sistémica asociados a la administración del NO. La sobrevida fue de 18/24 pacientes (75 porciento). Conclusiones: el uso terapéutico de NO inhalado en pacientes críticamente enfermos con HP, dentro de un protocolo de administración y monitoreo, es seguro, mejora la oxigenación y/o disminuye los episodios de HP constituyendo una valiosa herramienta en el tratamiento de este grupo de pacientes.

Oxido nítrico: ensayo clínico en niños con hipertensión pulmonar grave en el post-operatorio de cardiopatías congénitas / Nitric oxide: clinical trial in children with severe pulmonary hypertension after cardiac surgery for congenital heartdisease

jetivo: evaluar en un ensayo clínico a muestras relacionadas la respuesta al óxido nítrico (NO) en niños con hipertensión pulmonar (HP) grave post cirugía cardiovascular. Pacientes y Métodos: 24 pacientes (5 por ciento) internados en la unidad de recuperación cardiovascular entre agosto de 1996 y agosto de 1997 recibieron NO inhalado por padecer HP grave postoperatoria y fracaso al tratamiento convencional. Las indicaciones se categorizaron en 4 grupos: 1) Tratamiento con monitoreo directo de la presión arterial pulmonar (PAP). 2) Sin monitoreo directo, con evaluación clínica y ecocardiográfica. 3) Con gradiente transpulmonar >15 mmhg. 4) Uso preventivo. Se controlaron presión arterial y pulmonar, gases en sangre antes y después de la administración, metahemoglobinemia cada 12 hs, control ambiental de NO y NO2 cada 4 hs y ecocardiograma pre y post-no. En el análisis estadístico se compararon los valores de la pao2 antes y después de la administración del NO utilizando el wilcoxon rank test para dos colas (gpis).Se consideró significativa una p<0.05. Resultados: la mediana de edad fue de 8.7m, y la de peso de 4.2 kg., la mediana del tiempo de administración fue 69 hs (2-317 hs) con una dosis máximapromedio de 26 +- 22 ppm. Diez y nueve pacientes (80 por ciento) tuvieron una respuesta favorable; en 12 de ellos se observó un incremento de la pao2 basal superior al 30 por ciento. La mediana de la pao2 previa fue de 94 torr (r=36-428) con una posterior de 155 torr (r=34-683), p=0.009. Los niveles promedio de metahemoglobinemia fueron de 2 por ciento. Los niveles de NO y NO2 ambientales fueron menores de 1 ppm. No se observaron fenómenos de hipotensión arterial sistémica asociados a la administración del NO. La sobrevida fue de 18/24 pacientes (75 porciento). Conclusiones: el uso terapéutico de NO inhalado en pacientes críticamente enfermos con HP, dentro de un protocolo de administración y monitoreo, es seguro, mejora la oxigenación y/o disminuye los episodios de HP constituyendo una valiosa herramienta en el tratamiento de este grupo de pacientes. (AU)

Análise da proliferaçäo endosteal após a colocaçäo de "discos" de titânio c.p. em coelhos, tratados por diferentes formas / Analysis of the endosseus proliferation after the titanium c.p. \"discs\" implantation in rabbits, by different treatments

Recentemente, tem tornado aparente que o sucesso do implante endosteal é largamente, se näo totalmente, determinado pela biocompatibilidade do material usado. Esta biocompatibilidade parece estar determinada näo somente pela natureza química do material, mas também pela propriedade micromorfológica da superfície do implante. Os resultados apresentam uma avaliaçäo histológica da cicatrizaçäo inicial da implantaçäo de discos de titânio c.p. com superfície porosa fixados endostealmente. Para testar esta avaliaçäo foram utilizados 12 coelhos machos com peso médio de 3,2 Kg., sendo que cada animal recebeu 2 discos de titânio c.p.. Em todos os animais, os discos de titânio foram utilizados para avaliaçäo histológica de crescimento ósseo...