A mixed cell culture model for assessment of proliferation in tonsillar tissues from children with obstructive sleep apnea or recurrent tonsillitis.

BACKGROUND: Recurrent infective tonsillitis (RI) and obstructive sleep apnea (OSA) are the major indications for adenotonsillectomy (T&A) in children. However, little is known on the determinants of lymphadenoid tissue proliferation in the pediatric upper airway. OBJECTIVES: To develop an in vitro culture system allowing for assessment of tonsillar or adenoidal proliferation under basal or stimulated conditions. METHODS: Tonsils surgically removed from pediatric patients with obstructive sleep apnea and recurrent tonsillitis during T&A, were dissociated using standard methods. Whole cell tonsillar cultures were either maintained in normal medium or stimulated with lipopolysaccharide (25 microg/mL) and concanavalin A (10 microg/mL) for 24 hours (stimulated conditions [STIM]). Cellular proliferation was evaluated by [3H]thymidine incorporation. In parallel, supernatants were collected after 48 hours, and concentration of cytokines was measured using standard enzyme-linked immunosorbent assay procedures. RESULTS: Basal proliferative rates were increased in the OSA group (305.2 +/- 40.6 cpm; n = 31) compared to RI group (232.8 +/- 31.9 cpm; n = 26; P < .001). No significant differences in proliferative rates emerged after STIM between OSA and RI. Furthermore, basal TNF-alpha, IL-6, and IL-8 concentrations in the supernatant were increased in OSA-derived cultures compared to RI, but IL-8 was higher after STIM in RI, while IL-6 remained increased in OSA. CONCLUSIONS: The proliferative rates and concentrations of inflammatory mediators in tonsillar cell cultures from children with OSA and RI suggest that lymphadenoid tissue proliferation in these two conditions may be regulated by different mechanisms. This novel method may allow for future development of specific therapeutic interventions aimed at curtailing and reversing tonsillar and adenoidal hypertrophy in children in a disease-specific manner.

Explaining the poor bacteriologic eradication rate of single-dose ceftriaxone in group a streptococcal tonsillopharyngitis: a reverse engineering solution using pharmacodynamic modeling.

OBJECTIVE: To explore pharmacokinetic factors underlying the poor bacteriologic eradication rate with a single 500-mg dose of ceftriaxone for streptococcal tonsillopharyngitis and to identify the minimum ceftriaxone dose required for effective treatment. METHODS: Population modeling techniques were applied to pharmacokinetic data derived from paired plasma and tonsil samples from 153 children to assess the contribution of pharmacokinetic variability to patients' responses to ceftriaxone. In addition, a Monte Carlo simulation was performed to determine (1) the amount of time that free ceftriaxone concentrations must exceed the minimum inhibitory concentration (MIC) of group A Streptococcus to achieve bacteriologic eradication and (2) the ceftriaxone dose required to maintain free drug concentrations above the target MIC for the requisite amount of time. Ceftriaxone MICs for group A Streptococcus were obtained from a previous trial, in which all MICs (n = 115) were < or = 0.064 mg/L; 33.9% were susceptible at < or = 0.016 mg/L, 66.4% were susceptible at 0.032 mg/L, and 1.7% were susceptible at 0.064 mg/L. RESULTS: Mean population pharmacokinetic parameters and their variances reflected substantial variability of clearance and half-life in the target population. Tonsillar ceftriaxone protein binding was 89.1%. The proportions of 1000 simulated patients with free ceftriaxone concentrations that exceeded MICs of 0.016 mg/L, 0.032 mg/L, and 0.064 mg/L at 24 hours were 71.7%, 65.4%, and 57.2%, respectively, and at 48 hours were 41.8%, 35.8%, and 28.6%, respectively. The amount of time that free ceftriaxone concentrations need to exceed MIC to achieve bacteriologic success was estimated to be 36 hours. Using this time criterion, two 500-mg doses of ceftriaxone separated by 18 hours should achieve a bacteriologic cure rate of approximately 95%. CONCLUSIONS: Pharmacokinetic variability and high ceftriaxone tonsillar protein binding explain the high microbiologic failure rate for a single 500-mg dose of ceftriaxone in group A streptococcal tonsillopharyngitis. Monte Carlo simulation suggests that a second dose administered 18 hours after the first will be required to achieve an acceptable bacteriologic cure rate.

[Assessment of general and local immunity in children with affected lymphadenoid throat ring]. / Otsenka obshchego i mestnogo immuniteta u detei pri porazhenii limfadenoidnogo kol'tsa glotki.

33 children with affected lymphadenoid throat ring and 15 healthy children were examined for local and general immunity status. Assessment of general immunity provided poor information. Measurements of secretion immunoglobulins levels with enzyme immunoassay was informative and demonstrated close similarity of the clinical and immunological indices. Concentrations of immunoglobulins in the lacunar secretion can serve a prognostic criterium.

The effect of primary fixation with standard postfixation and the duration of hydrolysis on nuclear features in image cytometry.

The effect of three primary fixation procedures, used in the preparation of routine cytological samples: air-drying, Delaunay, and Saccomanno fixation, with postfixation in modified Böhm-Sprenger fixative, on nuclear features as a function of hydrolysis time is reported. Three different cell types: lymphatic cells (tonsil), epithelial cells (buccal mucosa) and mesenchymal cells (uterine myometrium) were used for the study. Our findings show, that generally not all features have the same plateau times as the IOD (integrated optical density), and that many features show different values depending on cell type and fixation method. It is therefore recommended that for any primary fixative used in routine clinical work and for each cell type, the hydrolysis curve for all nuclear features to be used in sample analysis should be established.