Dissolution of pulp tissue by aqueous solution of chlorhexidine digluconate and chlorhexidine digluconate gel.

AIM: To evaluate the activity of various root canal irrigants on bovine pulp tissue. METHODOLOGY: The irrigants tested were: 0.5, 1.0 and 2.5% sodium hypochlorite; 2% aqueous solution of chlorhexidine digluconate; 2% chlorhexidine digluconate gel (Natrosol); and distilled water as control. Bovine pulp fragments were weighed and placed in contact with 20 mL of each tested substance in a centrifuge at 150 r.p.m. until total dissolution. Dissolution speed was calculated by dividing pulp weight by dissolution time. Statistical analysis was performed using the Kruskal-Wallis test. RESULTS: Distilled water and both solutions of chlorhexidine did not dissolve the pulp tissue within 6 h. Mean dissolution speeds for 0.5, 1.0 and 2.5% sodium hypochlorite solutions were 0.31, 0.43 and 0.55 mg min(-1), respectively. The solvent ability of chlorhexidine solutions was similar to that of distilled water. The results for sodium hypochlorite solutions, chlorhexidine solutions and distilled water were statistically different (P>0.01). CONCLUSIONS: Both chlorhexidine preparations and distilled water were not able to dissolve pulp tissue. All sodium hypochlorite solutions were efficient in dissolving pulp tissue; the dissolution speed varied with the concentration of the solution.

Outcome study of bilateral lateral rectus recession for intermittent exotropia in children.

BACKGROUND AND OBJECTIVE: The purpose of this paper is to report a statistical analysis of the surgical results in a consecutive series of 52 children treated by bilateral lateral rectus recession for intermittent exotropia when the operating surgeon was confronted by an increase in manifestation of the strabismus. PATIENTS AND METHODS: The charts were abstracted for age at initial surgery, quantity of initial deviation, initial refraction, motor alignment at one week, six months, and at the end of the study. The incidence and result of secondary surgery and the incidence of the monofixation syndrome result was also determined. RESULTS: Thirty-two (62%) of the patients were successfully aligned at six months by the initial surgery performed for a mean of 25 prism diopters (PD) of preoperative deviation at a mean age of 4 years 8 months. Eleven patients (21%) were undercorrected and 9 patients (17%) were overcorrected at the six month exam. The patients were followed for a mean of 4 years, 4 months. Alignment at 6 months postoperatively was predictive of success by the end of the study, but the age at initial surgery, the size of the deviation, esotropia at 1 week, and initial refraction were not predictive of success. Secondary surgery was performed in 11 patients and the monofixation syndrome result was found in 5 patients. CONCLUSION: Successful alignment was achieved in the majority of children treated by an initial bilateral lateral rectus recession utilizing a currently popular surgical dosage table. Long term alignment success was not predicted by esotropia during the first postoperative week or the age at initial surgery but was correlated with the 6-month data. Secondary surgery was performed in 20% and the incidence of the monofixation syndrome was approximately 10% at the end of the study.

Outcome study of bilateral lateral rectus recession for intermittent exotropia in children.

PURPOSE: This paper reports an outcome study of 52 consecutive children treated by bilateral lateral rectus recession for intermittent exotropia over a 9 year period (1981-90) with a minimum follow up of 6 months. METHODS: Successful alignment was defined as the absence of any postoperative intermittent or constant tropia in any position of gaze. The study examined the variables that might be predictive of successful alignment. The charts were abstracted for age at initial surgery, quantity of initial deviation, initial refraction, motor alignment at 1 week and 6 months, final alignment, secondary surgery results and the incidence of a monofixation syndrome result. RESULTS: Motor tests demonstrated that 32 (62%) of the patients were successfully aligned by the initial procedure performed for a mean of 25 prism diopters of preoperative deviation while viewing distant targets at a mean age of 4 years 8 months, followed for a mean of 4 years, 4 months. The incidence of undercorrections and overcorrections were approximately equal in quantity suggesting that the current surgical dosage was adequate, but the age at initial surgery, initial deviation, initial refraction and 1 week postoperative alignment results were not predictive of success. Alignment at 6 months, however, was highly correlated with successful alignment by the end of the study (p = 0.002). Secondary surgery was performed for 11 patients and 5 patients were found to have a monofixation syndrome result. CONCLUSION: Successful alignment was achieved in the majority of children treated for intermittent exotropia by an initial bilateral lateral rectus recession. However, 20% of the patients received secondary surgery for a residual deviation, and the study confirmed a previously reported 10% incidence of monofixation syndrome result in children surgically treated for this type of strabismus.

Survival of fungi preserved by lyophilization after 49 years

A recuperaçäo de 75 linhagens de fungos filamentosos (Deuteromycotina, Ascomycotina e Zygomycotina) e 10 culturas de leveduras mantidas em estado liofilizado durante 49 anos foi examinada. Estas culturas foram doadas ao Instituto de Botânica em Säo Paulo, em 1980, tendo sido processadas no "Northern Regional Research Laboratories" (NRRL) em Peoria, Illinois nos Estados Unidos em 1943 pelo Dr. Enrique Duprat durante um período de treinamento sob a orientaçäo dos Dr. K. Raper, Dr. D. Fennel e Dr. S. Wickerham. Para a revitalizaçäo das culturas, os tubos liofilizados foram rompidos, o conteúdo dissolvido em água destilada esterilizada, vertido sobre meio de batata-dextrose-agar e incubado durante uma semana a 20oC. Características morfológicas e taxonômicas foram observadas para cada cultura, examinando o crescimento das colônias e estruturas microscópicas para confirmar a identificaçäo original. Dos 85 isolados liofilizados, 49 (55 por cento), divididos em 43 linhagens de fungos filamentosos e 6 de leveduras foram recuperadas. Os resultados foram comparados e discutidos em termos da longevidade e viabilidade do processo de liofilizaçäo para a preservaçäo de fungos