The efficacy of pulse-dosed antibiotic therapy in the management of persistent otitis media with effusion.

Consensus has been achieved supporting the efficacy of antimicrobials in the management of acute otitis media with effusion (OME). No such agreement has been reached into medical management of the patient in whom middle ear effusion (MEE) persists beyond the conventional 10- to 14-day treatment cycle. This study is designed to demonstrate the efficacy of antibiotics administered in a single daily dose in the management of persistent otitis media with effusion (POME). Seventy-nine subjects who had MEE in 116 ears after conventional therapy were randomized into medication and placebo groups and followed by the authors on a blinded basis. The results demonstrate the efficacy of pulse-dosed antibiotics in the management of POME. Prevention of relapses during therapy was responsible for the superior outcome for children in the treatment group.

Availability predictions by hepatic elimination models for Michaelis-Menten kinetics.

Numerical methods have been used to compare the availability predictions of a number of hepatic elimination models when Michaelis-Menten kinetics is operative. Propranolol and galactose were used as model compounds. Lower availabilities were predicted by the dispersion model than by a segregated distribution model for both compounds. The differences in the predictions were most pronounced for models corresponding to a large variation in solute residence times in the liver. The predictions of the tank-in-series, dispersion model with mixed boundary conditions and dispersion model with Dankwerts boundary conditions were similar over all concentrations studied. Changes in blood flow and protein binding provided little discrimination between the model predictions. It is concluded that micromixing of blood between sinusoids and the anatomical sites of mixing are important determinants of availability when liver eliminating enzymes are partially saturated.

Bacterial tracheitis in children.

Bacterial tracheitis is a relatively rare cause of respiratory distress in children and is associated with a high morbidity and mortality rate. Three children who have survived this affliction are presented: one developed toxic shock syndrome in the acute phase and two developed late complications. The authors review the pediatric literature and postulate possible etiological factors. Prompt diagnosis and aggressive airway management are essential to survival. Early tracheotomy is recommended as the primary form of airway management.

Surgical management of obstructive sleep apnea in children with Down syndrome.

Obstructive sleep apnea (OSA) is relatively common in children with Down Syndrome due to anatomical and immunological variations which place them at particular risk. Secondary cardio-respiratory complications of upper airway obstruction may be found at the time of initial diagnosis; these require medical therapy before surgical correction of the OSA is attempted. The selection of appropriate surgical therapy is influenced by the anatomical structure of the individual child. Tonsillectomy and adenoidectomy alone infrequently provide lasting relief of obstruction for these children. We have found that uvulopalatopharyngoplasty (UPPP), with or without simultaneous anterior reduction of the tongue, alleviates this form of airway obstruction. This paper describes the procedures and reports our experience of six patients with Down syndrome.

Obese hypoventilation syndrome of early childhood requiring ventilatory support.

In December 1986 a 30-month-old female child with morbid obesity and respiratory failure was admitted to the Izaak Walton Killam Hospital for Children in Halifax. The etiology of the obesity was found to be dietary in origin after ruling out genetic, neurological and metabolic causes. This patient exhibited somnolence and cyanosis in association with hypercapnia and right ventricular overload. Her respiratory failure in the presence of a normal upper airway required ventilatory support, first with nasal endotracheal intubation, and then, tracheotomy. Weight reduction normalized her capillary blood gases and her somnolence disappeared. Subglottic stenosis hampered removal of the tracheotomy tube until 9 months after admission. The pathogenesis and management of obese hypoventilation syndrome are reviewed by the authors.

Observations on the efficacy of intranasal beclomethasone dipropionate in cystic fibrosis patients.

The authors report the subjective results on the use of intranasal beclomethasone dipropionate in patients with cystic fibrosis. This medication has demonstrated positive results for these patients, whether polyps are present or not, and its use should be considered whenever symptoms of obstruction are present.

Models of hepatic elimination: comparison of stochastic models to describe residence time distributions and to predict the influence of drug distribution, enzyme heterogeneity, and systemic recycling on hepatic elimination.

The residence time distribution of noneliminated solutes in the liver can be represented by a variety of stochastic models. The dispersion model (closed and mixed boundary conditions), gamma distribution, log normal distribution and normal distribution models were used to describe output concentration-time profiles after bolus injections into the liver of labeled erythrocytes and albumin. The dispersion model and log normal distribution model provide the best representation of the data and give similar estimates of relative dispersion and availability for varying hepatocellular enzyme activity. The availability of solutes eliminated from the liver by first-order kinetics is determined by the residence time distribution of the solute in the liver and not on events occurring in the liver when a uniform enzyme distribution is assumed. Both enzyme heterogeneity (axial or transverse) and hepatocyte permeability may affect solute availability. A more complex model accounting for enzyme distribution and the micromixing of solute within the liver is required for solutes undergoing saturable kinetics.

Relationship between duodenal bile acids and colorectal neoplasia.

To investigate a possible relationship between bile acids and colorectal neoplasia duodenal bile acids were analysed in 50 patients with colorectal adenomas and 14 with carcinoma. Using gas liquid and high performance liquid chromatography a small, but significant increase in the proportion of chenodeoxycholic acid was found in the bile of adenoma patients compared with controls (mean % +/- SD 31.0 +/- 10.8, 26.4 +/- 8.3, p = 0.01). The difference in the proportions of chenodeoxycholic acid correlated with increasing malignant potential of the adenomas as determined by increasing size, histological type, degree of dysplasia and number present. In carcinoma patients an increase in the proportion of chenodeoxycholic acid was also observed compared with controls (mean % +/- SD, 47.2 +/- 9.6, 28.0 +/- 4.5, p less than 0.01). The proportions of other bile acids in those with adenoma or carcinoma were normal.

Otitis media, 1987.

This paper summarizes current concepts in otitis media for the clinician. Otitis media with effusion appears to be a disease spectrum which follows one of four recognizable patterns in children. Recognition of such patterns assists the otolaryngologist in selecting appropriate medical or surgical treatment for the individual child.

Mini-myringoplasty in the treatment of tympanic atelectasis.

Mini-myringoplasty is an outpatient procedure developed to simultaneously lateralize the tympanic membrane and provide middle ear ventilation in patients who have developed atelectasis. This paper describes the operative procedure and reports on 50 consecutive cases in which these objectives were achieved. Patients experience a minimum of discomfort. Restoration of the normal tympanic membrane configuration and improvement in hearing are noted within a few days.

Relationship between histology and gastric juice pH and nitrite in the stomach after operation for duodenal ulcer.

One hundred patients who had undergone operation for duodenal ulcer (68 vagotomy and gastroenterostomy; seven vagotomy and pyloroplasty; 22 gastrectomy and three gastroenterostomy) 10 or more years previously each underwent endoscopy. Biopsies were taken and gastric juice aspirated for measurement of pH and nitrite concentration. Patients were divided into five histological grades; chronic superficial gastritis (+/- minimal atrophic gastritis) (35), atrophic gastritis/intestinal metaplasia (30), mild dysplasia (21), moderate/severe dysplasia (13) and carcinoma (one). A wide spectrum of pH values was found with 35 patients having a fasting intragastric pH below 4.0 and 65 above 4.0. A strong relationship was found between histological grade and pH. Patients with chronic superficial gastritis had a fasting intragastric pH below 4.0 more frequently than those with moderate/severe dysplasia (p less than 0.001). Gastric juice nitrite concentrations were higher in the moderate/severe dysplasia group than in the chronic superficial gastritis group (p = 0.02). The strong correlation between pH and nitrite concentration, previously documented, was confirmed. The implications of these findings in the pathogenesis of carcinogenesis in the postoperative stomach are discussed.

Comparison of mucus substances in gastric juice of normal subjects, duodenal ulcer and dyspeptic patients.

The sugar and nitrogen content of the gastric juice was assessed in 27 patients with duodenal ulceration, 17 patients with dyspepsia, and 27 normal volunteers. Comparing the data for each constituent for each patient using a discriminant function analysis, it was shown that the normal group differed significantly from both the duodenal ulcer group and the dyspeptic group, but that there was only a degree of variation between the two groups of patients.

The assessment of mucus substances in gastric juice from duodenal ulcer patients and normal subjects.

The carbohydrate and nitrogen content of the gastric juice was assessed in 18 persons whose diagnosis were unknown to the investigators and the data compared by discriminant function analysis with similar measurements from 42 patients with proven duodenal ulceration and 22 normal controls. It was possible to assess correctly 14 of the 18 patients (77.8%) of the unknown group as having a duodenal ulcer. The results of three patients (16.7%) were equivocal, and one person (5.5%) was wrongly classified. The investigation confirms that the carbohydrate and nitrogen content of gastric secretion in duodenal ulcer patients is abnormal.