A new method of monitoring catheter-directed thrombolysis for deep venous thrombosis-application of D-dimer and fibrinogen testing.

BACKGROUND: Catheter-directed thrombolysis (CDT) is one of the main treatment methods for acute deep venous thrombosis (DVT), which has the characteristics of long treatment time and large dosage of thrombolytic drugs. In the absence of good monitoring methods, problems such as low thrombolytic efficiency and high risk of bleeding are easy to occur. OBJECTIVE: To evaluate the value of D-dimer (D-D) and fibrinogen (FIB) testing as a thrombolysis-monitoring method during CDT for acute DVT. METHODS: Twenty patients with acute DVT were divided into group A and group B. During CDT, the D-D and FIB testing every 8 h were used in group A, and the venography and FIB testing every 24 h in group B. The thrombolysis rate, thrombolysis time, urokinase dosage, and X-ray radiation dose were compared. RESULTS: The thrombolysis rate in group A was significantly higher than that in group B (p < 0.05), but the number of venography and radiation dose were significantly lower than those in group B (p < 0.05). CONCLUSION: D-D and FIB testing can improve the thrombolysis rate, reduce the risk of bleeding, and decrease the number of angiograms and X-ray radiation dose during CDT.

Enumeration and viability of rare cells in a microfluidic disk via positive selection approach.

Recent studies have shown that specific rare cells in the blood can serve as an indicator of cancer prognosis, among other purposes. This article demonstrates the concept of separating and detecting rare cells from peripheral blood mononuclear cells via an economical microfluidic disk with a model system. MCF7, labeled with magnetic beads, was used to simulate circulating tumor cells as a target. Jurkat clone E6-1 was used to simulate leukocytes or other cells abundant in human blood. A tailored multistage magnet maximized the magnetic field to ensure optimal trapping efficiency. Results indicate that the yield of detected MCF7 was consistent at approximately 80% when fewer than hundreds of MCF7 cells were mixed in greater than 1 million Jurkat cells. The 80% yield also held for 10 MCF7 in 100 million Jurkat (rarity of 10(7)). Compared with the results from autoMACS, the performance was at least 20% higher and was more independent of the number of Jurkat. The viability of the enriched cells was approximately 90 ± 20%, showing that this method caused little damage to trapped cells. The microfluidic disk should be applicable for separation and detection of various rare cells, such as circulating tumor cells and circulating endothelial cells in human blood.

Detection of circulating endothelial cells via a microfluidic disk.

BACKGROUND: Circulating endothelial cells (CECs) in the blood are rare but have been shown to be associated with various diseases. With the ratio of CECs to peripheral blood mononuclear cells (PBMCs) less than 1 part per thousand, their separation from PBMCs and detection are challenging. We present a means of detecting CECs from PBMCs via an economical microfluidic disk with a model cell system [human umbilical vein endothelial cells (HUVECs) in PBMCs], along with demonstration of its efficacy clinically. METHODS: To enrich these rare cells, we used immunomagnetic beads and a tailor-made magnet on the disk. CEC-simulating HUVECs, as target cells, were stained with primary anti-CD146-phycoerythrin antibody and bound with secondary antibody on antiphycoerythrin magnetic beads. PBMCs served as nontarget cells and were labeled with anti-CD45-FITC antibody. RESULTS: When hundreds of HUVECs were mixed in 10(6) PBMCs, 95% of spiked HUVECs were detected. This yield also held for 60 HUVEC in <10(4) PBMCs. We compared data from flow cytometry with that from the disk: CEC counts in 50 µL blood from patients with systemic lupus erythematosus were 61.1 (21.5), significantly higher (P < 0.01) than those of healthy donors, 31.2 (13.3). CONCLUSIONS: The count of CECs is a suitable marker for symptoms of systemic lupus erythematosus. The microfluidic disk system should be a viable platform for detection of CECs.

Separation and detection of rare cells in a microfluidic disk via negative selection.

Cyto-analysis of rare cells often requires separation and detection with each procedure posing substantial challenges. This paper presents a disk-based microfluidic platform for both procedures via an immunomagnetic negative selection process. The microfluidic platform's unique features include a multistage magnetic gradient to trap labeled cells in double trapping areas, drainage of fluid to substantially shorten detection time, and a bin-like regions to capture target cells to facilitate a seamless enumeration process. Proof-of-concept was conducted using MCF7 as target rare cells (stained with anti-cytokeratin-FITC antibodies) spiked into Jurkat Clone E6-1 non-target cells (labeled with anti-CD45-PE and anti-PE BD magnetic beads). Then, mononuclear cells (MNC) from healthy blood donors were mixed with MCF7s, modeling rare cells, and tested in the disk. Results show a non-linear magnetic coupling effect of the multistage magnet substantially increased the trapping efficacy over that of a single magnet, contributing to the depletion rate of Jurkats, which reaches 99.96%. Detection time is extensively shortened by depletion of 95% of non-cell-containing fluid in the collection area. The average yield of detected MCF7 cells is near-constant 60 ± 10% over a wide range of rarity from 10(-3) to 10(-6) and this yield also holds for the MCF7/MNC complex mixture. Comparison with autoMACS and BD IMagnet separators revealed the average yield from the disk (60%) is superior to that of autoMACS (37.3%) and BD IMagnet (48.3%). The advantages of near-constant yield, roughly 30 min of operation, an acceptable level of cell loss, and potentially low cost system should aid in cyto-analysis of rare cells.

[Comparative study of the parameters related to type I thyroplasty measured by laryngeal specimens and computed tomography].

OBJECTIVE: To determine the consistence of the parameters related to type I thyroplasty measured by laryngeal specimens and CT scan. METHODS: The related parameters of 50 laryngeal specimens (unilateral) obtained following total laryngectomy were measured postoperative immediately, and compared with those measured by spiral CT scan with multiple plain reconstructive (MPR) technique preoperatively. Comparative results were analyzed to evaluate the statistical significance between these two methods. RESULTS: There were no significant statistical differences among the 6 parameters between two methods (P > 0.05), and the results (x +/- s) measured by CT scan and laryngeal specimens showed that the length of the thyroid notch to the inferior thyroid border were (20.7 +/- 1.7) mm and (20.6 +/- 1.7) mm; the length of the vocal cord were (17.3 +/- 1.8) mm and (17.3 +/- 1.8) mm; the length of the oblique line were (28.6 +/- 3.2) mm and (29.1 +/- 2.7) mm; the length of the presumptive horizontal line were (26.2 +/- 2.0) mm and (26.2 +/- 2.0) mm; the endolaryngeal vertical length of the anterior of the vocal cord to the presumptive horizontal line were (4.5 +/- 0.6) mm and (4.5 +/- 0.7) mm; the endolaryngeal vertical length of the vocal process to the presumptive horizontal line were (10.8 +/- 1.1) mm and (10.9 +/- 1.1) mm, respectively. As a result, the endolaryngeal anterior and posterior width of the wedge inserted in the thyroid cartilage were 4 - 5 mm and 8 - 9 mm respectively. CONCLUSIONS: MPR technique of spiral CT scan is able to design the size of the window and the prosthesis of type I thyroplasty preoperatively, which was testified to be a precise and reliable method to measure the larynx.