Appendiceal Intussusception Mimicking Cecal Mass and Fecal Matter: A Report of Two Rare Cases

Intussusception of the appendix is a relatively rare event that is usually asymptomatic but can present similar to other acute and chronic abdominal conditions. We present two separate cases of suspected appendiceal intussusception mimicking cecal masses. The authors also present a cursory review of the limited number of literatures available concerning this entity to help the radiologist avoid misdiagnosis and potentially unnecessary invasive intervention

Overdiagnosis of COPD in Subjects With Unobstructed Spirometry: A BOLD Analysis

Background There are several reports on underdiagnosis of COPD, while little is known about COPD overdiagnosis and overtreatment. We describe the overdiagnosis and the prevalence of spirometrically defined false positive COPD, as well as their relationship with overtreatment across 23 population samples in 20 countries participating in the BOLD Study between 2003 and 2012. Methods A false positive diagnosis of COPD was considered when participants reported a doctor’s diagnosis of COPD, but postbronchodilator spirometry was unobstructed (FEV1/FVC > LLN). Additional analyses were performed using the fixed ratio criterion (FEV1/FVC Results Among 16,177 participants, 919 (5.7%) reported a previous medical diagnosis of COPD. Postbronchodilator spirometry was unobstructed in 569 subjects (61.9%): false positive COPD. A similar rate of overdiagnosis was seen when using the fixed ratio criterion (55.3%). In a subgroup analysis excluding participants who reported a diagnosis of “chronic bronchitis” or “emphysema” (n = 220), 37.7% had no airflow limitation. The site-specific prevalence of false positive COPD varied greatly, from 1.9% in low- to middle-income countries to 4.9% in high-income countries. In multivariate analysis, overdiagnosis was more common among women, and was associated with higher education; former and current smoking; the presence of wheeze, cough, and phlegm; and concomitant medical diagnosis of asthma or heart disease. Among the subjects with false positive COPD, 45.7% reported current use of respiratory medication. Excluding patients with reported asthma, 34.4% of those with normal spirometry still used a respiratory medication. Conclusions False positive COPD is frequent. This might expose nonobstructed subjects to possible adverse effects of respiratory medication.</p

Si-Based Magnetic Semiconductors

The efforts over the past decade to identify and characterize magnetic semiconducting systems that would be compatible with present-day silicon technologies are reviewed. Investigations that have explored transition metal doping of the group IV semiconductors silicon and germanium are discussed along with intermetallic compounds such as silicides and germanides that may play the role of a magnetic semiconducting source of polarized electrons. Thin films and nanostructures of these materials have been grown by a number of synthesis techniques, and the resulting structural properties, including the important issue of homogeneity of dopants, are critically surveyed. The resulting magnetic and carrier transport properties are also reviewed