Development and testing of methods for detecting off-wrist in actimetry recordings.

STUDY OBJECTIVES: In field studies using wrist-actimetry, not identifying/handling off-wrist intervals may result in their misclassification as immobility/sleep and biased estimations of rhythmic patterns. By comparing different solutions for detecting off-wrist, our goal was to ascertain how accurately they detect nonwear in different contexts and identify variables that are useful in the process. METHODS: We developed algorithms using heuristic (HA) and machine learning (ML) approaches. Both were tested using data from a protocol followed by 10 subjects, which was devised to mimic contexts of actimeter wear/nonwear in real-life. Self-reported data on usage according to the protocol were considered the gold standard. Additionally, the performance of our algorithms was compared to that of visual inspection (by 2 experienced investigators) and Choi algorithm. Data previously collected in field studies were used for proof-of-concept analyses. RESULTS: All methods showed similarly good performances. Accuracy was marginally higher for one of the raters (visual inspection) than for heuristically developed algorithms (HA, Choi). Short intervals (especially < 2 h) were either not or only poorly identified. Consecutive stretches of zeros in activity were considered important indicators of off-wrist (for both HA and ML). It took hours for raters to complete the task as opposed to the seconds or few minutes taken by the automated methods. CONCLUSIONS: Automated strategies of off-wrist detection are similarly effective to visual inspection, but have the important advantage of being faster, less costly, and independent of raters' attention/experience. In our study, detecting short intervals was a limitation across methods.

From craniofacial resection to endonasal endoscopic removal of malignant tumors of the anterior skull base.

OBJECTIVE: To review the current literature and provide our institutional approach and opinion on the indications and limitations of traditional open craniofacial resection (CFR) and a minimally invasive pure endonasal endoscopic approach for anterior skull base tumors concentrating primarily on malignant lesions. METHODS: Based on 3 decades of experience with both open and more recently endoscopic techniques, we examined our current practice in treating tumors and other lesions involving the skull base and our current indications and limitations in the use of these techniques. We conducted a retrospective chart analysis to see which operative techniques were used for malignant tumors of the anterior skull base in the last 10 years at our institution. RESULTS: There were 30 cases identified. Traditional CFR was performed in 16, a pure endoscopic resection was performed in 9, and an endoscopic procedure combined with a frontal craniotomy was performed in 5. Gross total resection was achieved in 83.3% in the CFR group and 75% in the pure endoscopic resection group. Near-total resection was 10% in the CFR group and 33.3% in pure endoscopic resection group. Of the 5 patients who underwent a combined approach, 80% had gross total resection, and 20% had near-total resection. CONCLUSIONS: Both traditional CFR and the endonasal endoscopic approach offer advantages and disadvantages. Both approaches can achieve good results with appropriate patient selection. Numerous important factors, including location and the extent of tumor, should be taken into consideration when considering either approach. The most important determinant of outcome is the ability to achieve gross total resection with microscopic negative margins rather than the type of approach used. In the future, skull base surgeons will need to be familiar with and capable of offering both techniques to the patient.

Bone marrow multipotent mesenchymal stromal cells do not reduce fibrosis or improve function in a rat model of severe chronic liver injury.

The objective of our study was to evaluate the therapeutic potential of bone marrow mesenchymal stromal cells (MSC) in a rat model of severe chronic liver injury. Fourteen female Wistar rats were fed exclusively an alcoholic liquid diet and received intraperitoneal injections of carbon tetrachloride every other day during 15 weeks. After this period, eight animals (MSC group) had 1 x 10(7) cells injected into the portal vein while six animals (placebo group) received vehicle. Blood analysis was performed to evaluate alanine aminotransferase (ALT), aspartate aminotransferase (AST), and albumin before cell therapy and 1 and 2 months after cell or placebo infusion. Fibrosis was evaluated before and 1 month after cell or placebo injection by liver biopsies. Two months after cell delivery, animals were sacrificed and histological analysis of the livers was performed. Fibrosis was quantified by histomorphometry. Biopsies obtained before cell infusion showed intense collagen deposition and septa interconnecting regenerative nodules. One month after cell injection, this result was unaltered and differences in fibrosis quantification were not found between MSC and placebo groups. ALT and AST returned to normal values 2 weeks after cell or placebo infusion, without significant differences between experimental groups. Two months after cell or placebo injection, albumin had also returned to normal values and histological results were maintained, again without differences between MSC and placebo groups. Therefore, under our experimental conditions, MSC were unable to reduce fibrosis or improve liver function in a rat model of severe chronic liver injury.