Root canal dressings for revascularization influence in vitro mineralization of apical papilla cells

Abstract Endodontic revascularization is based on cell recruitment into the necrotic root canal of immature teeth after chemical disinfection. The clinical outcome depends on the ability of surviving cells from the apical tissue to differentiate and promote hard tissue deposition inside the dentinal walls. Objective To investigate the effect of calcium hydroxide (CH) and modified triple antibiotic paste (mTAP - ciprofloxacin, metronidazole and cefaclor) on the viability and mineralization potential of apical papilla cells (APC) in vitro . Material and Methods APC cultures were kept in contact with CH or mTAP (250-1000 µg/mL) for 5 days, after which cell viability was assessed using 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Next, APCs were subjected to CH or mTAP at 250 µg/mL for 5 days before inducing the differentiation assay. After 14 and 21 days, calcium deposition was assessed by the Alizarin Red S staining method, followed by elution and quantification using spectrophotometry. Data were analyzed using ANOVA followed by Tukey post hoc test. Results CH induced cell proliferation, whereas mTAP showed significant cytotoxicity at all concentrations tested. APC treated with CH demonstrated improved mineralization capacity at 14 days, while, for mTAP, significant reduction on the mineralization rate was observed for both experimental periods (14 and 21 days). Conclusion Our findings showed that CH induces cell proliferation and improves early mineralization, whereas mTAP was found cytotoxic and reduced the mineralization potential in vitro of APCs.

Evaluation of cefaclor oral suspensions stability using reversed phase high performance liquid chromatography and antimicrobial diffusion methods

The effect of temperature stresses on Cefaclor suspensions under different storage conditions for a duration of 14 days was tested. The degradation of Cefaclor was determined on the 2[nd], 7[th] and 14[th] day after reconstitution using a sensitive and precise Reversed phase High Performance Liquid Chromatographic [RP-HPLC] method. The RSD values for Forticef, Midocef, Ceclor, Cefabac and Cloracef, indicated a good precision of the RP-HPLC method. The limit of detection [LOD] and the limit of quantification [LOQ] were found 0.008 mg/ml and 0.03mg/ml respectively. The antimicrobial effect of Cefaclor suspension was also tested against pathogenic bacteria using the cylinder diffusion method. The RSD values range of the antimicrobial assay for all the Cefaclor compounds were 1.47-3.7%. The LOD and LOQ were 0.2mg/ml and Img/ml respectively. During the normal use of Ceclor, Midocef, and Forticef the loss of activity and the degradation were less than 5% on the 14[th] day of preservation at 4°C. However, the percentage of degradation for Cefabac and Cloracef on the 14th day reached 5 and 6%, respectively. Statistical multiple comparison between the effect of 4°C and 25°C indicated non significant mean differences [P >/= 0.05] for Forticef, Cefabac, Ceclor and Cloraf and significant effect for Midocef [P

Prevalência de Haemophilus influenzae resistentes a ampicilina, cefaclor, cefotaxime, cloranfenicol e cotrimoxazol isolados de laboratórios na cidade de Säo Paulo / Prevalence of Haemophilus influenzae resistant to ampicillin, cefaclor, cefotaxime, chloramphenicol and cotrimoxazol isolated from laboratories in the city of Säo Paulo, Brazil

Objetivo: Determinar a resistência à ampicilina e outros antimicrobianos de amostras de H. influenzae isoladas de diferentes materiais clínicos. Métodos; As amostras de H. influenzae foram identificadas por cultura com fatores V e X e prova do ácido amino-levulínico. A produçäo de ß-lactamase (ßLac) foi detectada pela nitrocefina. A sensibilidade aos antimicrobianos foi testada por difusäo do disco e diluiçäo em meio sólido. O sorotipo b foi testado por coaglutinaçäo. Resultados: De 245 H. influenzae identificados, 155 foram testados para o sorotipo b e 28 por cento (43/155) mostraram-se positivos...

Beta-lactamase production in recent clinical isolates of Haemophilus influenzae and their susceptibility to cefaclor and other antimicrobial agents

The ability of 383 recent clinical isolates of Haemophilus influenzae to produce beta-lactamase was detected by using cefinase discs. It was found that 8% of the isolates elaborate this enzyme. Since cefaclor supposedly is not inactivated by beta-lactamases of H. influenzae, we studied the in vitro activity of this cephalosporin and compared it with other commonly used antimicrobial agents against isolates of H. influenzae from 383 patients at a tertiary care referral hospital in Riyadh, Saudi Arabia. Cefaclor was found to be most active, inhibiting 98% of the isolates tested, followed by amoxycillin/clavulanic acid and gentamicin [95%], chloramphenicol [93%], cephalothin [90%], ampicillin [87%], tetracycline [77%] trimethoprim-sulphamethoxazole [65%] and erythromycin [47%]