Environmental risk factors for infection with Mycobacterium avium complex

Infection with Mycobacterium avium complex is acquired from the environment, but risk factors for M. avium complex infection and disease are poorly understood. To identify risk factors for infection, the authors performed a 1998-2000 cross-sectional study in western Palm Beach County, Florida, using a population-based random household survey. M. avium complex infection was identified by use of the M. avium sensitin skin test. Of 447 participants, 147 (32.9%) had a positive test reaction, 186 (41.6%) had a negative test reaction, and, for 114 (25.5%), test results were indeterminate. Among the 333 participants with positive or negative M. avium sensitin skin tests, age-adjusted independent predictors of M. avium complex infection in a multivariate model included Black race (odds ratio = 3.8, 95% confidence interval: 2.2, 6.6), birth outside the United States (odds ratio = 2.1, 95% confidence interval: 1.1, 3.9), and more than 6 years' cumulative occupational exposure to soil (odds ratio = 2.7, 95% confidence interval: 1.3, 6.0). Exposure to water, food, or pets was not associated with infection. Results indicate that soil is a reservoir for M. avium complex associated with human infection and that persons whose occupations involve prolonged soil exposure are at increased risk of M. avium complex infection.     

Plain films in the evaluation of batteries as esophageal foreign bodies

OBJECTIVE: To determine the sensitivity and specificity of plain films in differentiating coin batteries from coins. SETTING: Study was conducted at a tertiary referral university medical center. METHODS: Eleven radiographs were taken of various objects and independently reviewed by 14 radiologists and otolaryngologists. Reviewers were asked to identify the object filmed as either a battery or not a battery. In addition, otolaryngologists were asked if they would immediately proceed to the operative suite for removal based on the film. Results were tabulated and analyzed using a spreadsheet. RESULTS: Overall, plain films had a sensitivity and specificity of 80.4% and 79.1%, respectively with an overall accuracy of 79.8%. When used as a test to determine urgency of removal, sensitivity increases to 94.4% while specificity decreases to 67.1% with an overall accuracy of 83.1%. CONCLUSIONS: Plain films are an effective method of evaluating for the possibility of batteries as esophageal foreign bodies.     

Hypophosphatemic rickets in opsismodysplasia

BACKGROUND: Opsismodysplasia is a rare spondylo(epi)chondrodysplasia characteristized by delayed skeletal maturation and a constellation of dysplastic features. Although metaphyseal irregularities/cupping have been noted, neither renal phosphate wasting nor rickets have previously been reported. OBJECTIVE: To evaluate hypophosphatemia and rickets in opsismodysplasia. PATIENTS: Two girls with opsismodysplasia presenting with hypophoshpatemia by 3 years of age. METHODS: Routine biochemistries to assess hypophosphatemia and renal phosphate wasting; radiographs (rachitic changes) and DEXA scan (BMD); FGF23 levels, PHEX and FGF23 gene analyses performed (Patient 1). RESULTS: Both children had hypophosphatemia, decreased TRP, and rickets. Oral phosphorus and calcitriol improved metaphyseal mineralization, yet serum phosphate levels remained relatively low and renal phosphate wasting persisted. PHEX and FGF23 gene analyses were negative, whereas serum FGF23 levels were markedly elevated in Patient 1. CONCLUSION: We now demonstrate an association between opsismodysplasia, hypophosphatemic rickets, and FGF23 elevation. Screening phosphorus levels may thus uncover a potentially treatable component of this disease.     

Thymic carcinoma in a child with HIV infection

HIV infection predisposes to cancer during childhood. In addition to the AIDS-defining non-Hodgkin lymphoma (NHL) and Kaposi sarcoma, a range of other lymphoid malignancies and solid tumors have been described. We report the first case of an HIV-positive child with thymic carcinoma in the setting of regressing thymic cysts. The tumor expressed CKIT but failed to respond to imatinab mesylate after a transient response to multiagent chemotherapy. This case extends the spectrum of pediatric malignancy in the setting of HIV and suggests that patients with presumed benign thymic cysts require ongoing surveillance.     

Ethnic and gender differences in body fat in British schoolchildren as measured by DXA

Background

There are known to be ethnic differences in body composition in adults which are related to ethnic differences in adult disease.

Objectives

To evaluate gender and ethnic differences in percentage body fat in British schoolchildren and to compare these differences with classification of obesity using body mass index (BMI) criteria.

Design

A cross‐sectional study of 1251 healthy children and adolescents aged 5–18 years from white, South Asian and African‐Caribbean ethnic groups. Percentage body fat was determined by dual x ray absorptiometry and the subjects classified using BMI criteria for overweight and obesity.

Results

Significant gender differences in percentage body fat were seen, with girls having higher values from the age of 5 years. Girls had 3.8% higher percentage body fat at 5 years of age increasing to 12.9% at 18 years of age. Significant ethnic differences were found, with South Asian girls and boys having the highest percentage body fat from 5 and 7 years of age, respectively. These differences increased with age, being most significant in the teenage years. Although South Asian girls and boys were over‐represented in the group containing children with more than 25% body fat (p<0.0001, χ² test), African‐Caribbean subjects were more likely to be classified as obese using BMI criteria.

Conclusions

There are clear gender and ethnic differences in percentage body fat in British schoolchildren which may relate to known differences in the risk of type 2 diabetes in adolescence and adulthood. BMI criteria for defining overweight and obesity do not accurately identify ethnic differences in body fat.     

Respiratory damage in children exposed to urban pollution

Southwest Metropolitan Mexico City (SWMMC) children are chronically exposed to complex mixtures of air pollutants. In a cross-sectional arm of our study, we investigated the association between exposure to SWMMC atmosphere and nasal abnormalities, hyperinflation, and interstitial markings assessed by chest X-rays, lung function changes, several serum cytokines, and endothelin-1 in 174 children aged 5-17 years vs. 27 control children residents in low-polluted areas. Control children had no nasal lesions, and only one child showed an abnormal chest X-ray. SWMMC children exhibited nasal abnormalities (22%), hyperinflation (67%), interstitial markings (49%), and a mild restrictive pattern by spirometry (10%). Interstitial markings were associated with a decrease in predicted values of FEF(25-75), FEF(75), and the FEV(1)/FVC ratio. Boys had a higher probability of developing interstitial markings with age (P = 0.004). Blood smear findings included toxic granulations in neutrophils and schistocytes. SWMMC children had more serum IL10 and IL6 and less IL8 than controls. In a longitudinal arm of our study, we found a significant seasonal drop in FVC and FEV(1) associated with a 6-month period of high ozone and PM(10) levels. Our data strongly suggest that a lifelong exposure to urban air pollution causes respiratory damage in children. Moreover, a cytokine network becomes imbalanced, with a shift towards upregulation of anti-inflammatory cytokines. Consequently, these children are potentially at risk for developing chronic lung disease and other systemic effects later in life.