A multicenter, prospective, randomized comparison of a novel signal transmission capsule endoscope to an existing capsule endoscope.

BACKGROUND: MiroCam, a capsule endoscope, uses a novel transmission technology, electric-field propagation, which uses the human body as a conduction medium for data transmission. OBJECTIVE: To compare the ability of the MiroCam (MC) and PillCam (PC) to identify sources of obscure GI bleeding (OGIB). DESIGN: Prospective, multicenter, comparative study. SETTING: Six academic hospitals. PATIENTS: A total of 105 patients with OGIB. INTERVENTION: Patients ingested both the MC and PC capsules sequentially in a randomized fashion. MAIN OUTCOME MEASUREMENTS: Concordance of rates in identifying a source of OGIB, operational times, and rates of complete small-bowel examination. RESULTS: Data analysis resulted in 43 (48%) "abnormal" cases identifying a source of OGIB by either capsule. Twenty-four cases (55.8%) were positive by both capsules. There was negative agreement in 46 of 58 cases (79.3%). The κ index was 0.547 (χ(2) = 1.32; P = .36). In 12 cases, MC positively identified a source that was not seen on PC, whereas in 7 cases, PC positively identified a source that was not seen on MC. MC had a 5.6% higher rate of detecting small-bowel lesions (P = .54). MC captured images at 3 frames per second for 11.1 hours, and PC captured images at 2 frames per second for 7.8 hours (P < .0001). Complete small-bowel examination was achieved in 93.3% for MC and 84.3% for PC (P = .10). LIMITATIONS: Readers were not blinded to the particular capsule they were reading. CONCLUSION: A positive diagnostic finding for OGIB was identified by either capsule in 48% of cases. The concordance rate between the 2 capsules was comparable to that of prior studies in identifying sources of small-bowel bleeding. The longer operational time of the MC may result in higher rates of complete small-bowel examination, which may, in turn, translate into a higher rate of detecting small-bowel lesions. ( CLINICAL TRIAL REGISTRATION NUMBER: NCT00878982.).

Contributions of global and local processing on medical image perception.

Purpose: The influential holistic processing hypothesis attributes expertise in medical image perception to cognitive processing of global gist information. However, it has remained unclear whether or how experts use rapid global impression of images for their subsequent diagnostic decisions based on the focal sign of cancer. We hypothesized that continuous-global and discrete-local processes jointly attribute to radiological experts' detection of mammogram, with different weights and temporal dynamics. Approach: We examined experienced versus inexperienced observers' performance at first (500 ms) versus second (2500 ms) mammogram image presentation in an abnormality detection task. We applied a dual-trace signal detection (DTSD) model of receiver operating characteristic (ROC) to assess the time-varying contributions of global and focal cancer signals on mammogram reading and medical expertise. Results: The hierarchical Bayesian DTSD modeling of empirical ROCs revealed that mammogram expertise (experienced versus inexperienced observers) manifests largely in a continuous-global component for the detection of the gist of abnormality at the early phase of mammogram reading. For the second presentation of the same mammogram images, the experienced participants showed increased task performance that was largely driven by better processing of discrete-local information, whereas the global processing of abnormality remained saturated from the first exposure. Modeling of the mouse trajectory of the confidence rating responses further revealed the temporal dynamics of global and focal processing. Conclusions: These results suggest a joint contribution of continuous-global and discrete-local processes on medical expertise, and these processes could be analytically dissociated.

Esophageal Schwannoma: A Rare Benign Esophageal Tumor.

Benign primary tumors are uncommon, with the majority of these tumors being leiomyomas; schwannomas of the esophagus are rare. Here, we present a case of a 78-year-old woman referred for complaints of intermittent dysphagia with a chest computed tomography scan showing a homogenous mass, compressing the esophagus. Upper gastrointestinal endoscopy revealed a submucosal mass, which was eventually diagnosed as a schwannoma after an endoscopic ultrasound with fine-needle aspiration and subsequent pathologic and immunohistochemical examination. Schwannomas could be managed conservatively.

Hypocupremia-related myeloneuropathy following gastrojejunal bypass surgery.

Gastrojejunal bypass surgery may be complicated by nutritional deficiencies, including trace elements. Copper, which is absorbed in the duodenum and proximal jejunum, is poorly absorbed when a significant portion of the proximal small intestine is bypassed. However, despite this theoretical risk of hypocupremia in the gastrojejunal bypass patient, reports of symptomatic copper deficiency are very rare, and even then the deficiency is often potentiated by an accelerant, such as concomitant zinc ingestion. We report a case of hypocupremia resulting in hematologic abnormalities and myeloneuropathy after gastrojejunal bypass surgery for morbid obesity. It stresses the importance of recognizing nutritional deficiencies, particularly copper deficiency, because of the possible and serious sequelae of bone marrow suppression and myeloneuropathy. The early recognition and treatment of the symptoms of hypocupremia is emphasized to avoid these long-term sequelae. With the rapidly growing number of patients undergoing gastrojejunal bypass surgery for morbid obesity, the index of suspicion for hypocupremia must be heightened.

Magnetic poly epsilon-caprolactone nanoparticles containing Fe3O4 and gemcitabine enhance anti-tumor effect in pancreatic cancer xenograft mouse model.

We prepared magnetic (Fe(3)O(4)) poly epsilon-caprolactone (PCL) nanoparticles (mean diameter 164 +/- 3 nm) containing an anticancer drug (gemcitabine) using emulsion-diffusion method in order to develop more efficient drug delivery for cancer treatment. Nanoparticles were smooth, well individualized and homogeneous in size. The values of magnetizations for the magnetic PCL nanoparticles were observed around 10.2 emu/g at 2000 Oe magnetic field intensity and showed super-paramagnetic property. In case of the drug, the drug loading contents was 18.6% and entrapment efficiency was 52.2%. The anti-tumor effects caused by these particles were examined using nude mice bearing subcutaneous human pancreatic adenocarcinoma cells (HPAC) in vivo. We divided that these mice were randomly assigned to one of five treatment groups for experimental contrast. The antitumor effect was showed with 15-fold higher dose when compared to free gemcitabine. From the result, the magnetic PCL nanoparticles may provide a therapeutic benefit by delivering drugs efficiently to magnetically targeted tumor tissues, thus achieving safe and successful anti-tumor effects with low toxicity.

Gastrointestinal Tuberculosis.

Gastrointestinal tuberculosis (TB) is a fascinating disease which can be observed both in the clinical context of active pulmonary disease and as a primary infection with no pulmonary involvement. It represents a significant clinical challenge because of the resurgence of TB as well as the diagnostic challenges it poses. A high clinical suspicion remains the most powerful tool in an era of medicine when reliance on diagnostic technology increases. Antimicrobial therapy is the mainstay of therapy, but surgical and endoscopic interventions are frequently required for intestinal TB. Gastrointestinal TB is truly the "great mimic" and continues to require the astute clinical acumen of skillful clinicians to diagnose and treat.

Cofactors of mitochondrial enzymes attenuate copper-induced death in vitro and in vivo.

Copper toxicity contributes to neuronal death in Wilson's disease and has been speculatively linked to the pathogenesis of Alzheimer's and prion diseases. We examined copper-induced neuronal death with the goal of developing neuroprotective strategies. Copper catalyzed an increase in hydroxyl radical generation in solution, and the addition of 20 microM copper for 22 hours to murine neocortical cell cultures induced a decrease in ATP levels and neuronal death without glial death. This selective neuronal death was associated with activation of caspase-3 and was reduced by free radical scavengers and Z-Val-Ala-Asp fluoromethylketone, consistent with free radical-mediated injury leading to apoptosis. Pyruvate dehydrogenase is especially vulnerable to inhibition by oxygen free radicals, and the upstream metabolites, pyruvate, phosphoenolpyruvate, and 2-phosphoglycerate were elevated in cortical cells after toxic exposure to copper. One approach to protecting pyruvate dehydrogenase from oxidative attack might be to enhance binding to cofactors. Addition of thiamine, dihydrolipoic acid, or pyruvate reduced copper-induced neuronal death. To test efficacy in vivo, we added 1% thiamine to the drinking water of Long Evans Cinnamon rats, an animal model of Wilson's disease. This thiamine therapy markedly extended life span from 6.0 +/- 1.6 months to greater than 16 months.